WO2006104083A1 - Method of injection-molding hollow molded article, mold for injection molding, and boot made of resin - Google Patents

Method of injection-molding hollow molded article, mold for injection molding, and boot made of resin Download PDF

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Publication number
WO2006104083A1
WO2006104083A1 PCT/JP2006/306110 JP2006306110W WO2006104083A1 WO 2006104083 A1 WO2006104083 A1 WO 2006104083A1 JP 2006306110 W JP2006306110 W JP 2006306110W WO 2006104083 A1 WO2006104083 A1 WO 2006104083A1
Authority
WO
WIPO (PCT)
Prior art keywords
mold
resin
boot
diameter
molding
Prior art date
Application number
PCT/JP2006/306110
Other languages
French (fr)
Japanese (ja)
Inventor
Yasushi Noda
Kentaro Takesada
Original Assignee
Kaneka Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from JP2005096082A external-priority patent/JP4572717B2/en
Priority claimed from JP2005132203A external-priority patent/JP2006308002A/en
Priority claimed from JP2005191596A external-priority patent/JP2007010043A/en
Application filed by Kaneka Corporation filed Critical Kaneka Corporation
Publication of WO2006104083A1 publication Critical patent/WO2006104083A1/en

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J3/00—Diaphragms; Bellows; Bellows pistons
    • F16J3/04—Bellows
    • F16J3/041—Non-metallic bellows
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B29C45/2701—Details not specific to hot or cold runner channels
    • B29C45/2708—Gates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/40—Removing or ejecting moulded articles
    • B29C45/43—Removing or ejecting moulded articles using fluid under pressure
    • B29C45/435—Removing or ejecting moulded articles using fluid under pressure introduced between a mould core and a hollow resilient undercut article, e.g. bellows
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
    • F16D3/84—Shrouds, e.g. casings, covers; Sealing means specially adapted therefor
    • F16D3/843—Shrouds, e.g. casings, covers; Sealing means specially adapted therefor enclosed covers
    • F16D3/845—Shrouds, e.g. casings, covers; Sealing means specially adapted therefor enclosed covers allowing relative movement of joint parts due to the flexing of the cover
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2031/00—Other particular articles
    • B29L2031/703—Bellows

Definitions

  • the present invention relates to an injection molding method for a hollow molded article and an injection mold. More details
  • the present invention relates to a method for injection-molding a hollow molded product such as a coconut resin boot having a mold and a mold used therefor.
  • the present invention particularly relates to an injection molding method and an injection mold for the hollow molded product using thermoplastic resin.
  • the present invention also relates to a resin boot made by molding a thermoplastic elastomer by the injection molding method.
  • Constant velocity joint boots for automobiles are, for example, speeds between an input drive shaft and an output drive shaft, such as between a vehicle transmission and a propeller shaft, between a differential gear and a drive shaft, and between a drive shaft and a wheel. It is a cover that covers the joint part of the structure that rotates at the same speed with no difference.
  • This constant velocity joint boot has a function of preventing foreign matter from entering the joint portion and enclosing lubricating oil (grease).
  • the constant velocity joint boot includes a small-diameter mounting portion 2, a large-diameter mounting portion 3, and a bellows portion 4 that connects the two together.
  • the small-diameter mounting portion 2 is mounted on the outer periphery of the shaft, while the large-diameter mounting portion 3 is mounted on a non-circular outer shape outer case having three recesses such as a triport type constant velocity joint.
  • the bellows part 4 gradually decreases in diameter from the large-diameter attachment part 3 to the small-diameter attachment part 2 and has a substantially truncated cone shape as a whole.
  • the joint part of the automobile axle as described above is used under severe conditions where it is repeatedly bent while rotating at high speed, so it does not expand (deform) due to the centrifugal force generated by high-speed rotation! Both swingability and flexibility to withstand bending are required at the same time.
  • the constant velocity joint boot is generally manufactured by injection molding of chloroprene rubber.
  • Patent Document 1 chloroprene rubber is a vulcanized rubber and cannot be recycled. Therefore, boots made of recyclable polyester resin blow molding have come to be used.
  • polyester-based rosin boots are hard and brittle and lack flexibility, so they are used especially as constant-velocity joint boots that are used under the severe conditions of being bent repeatedly while rotating at high speed. Then there is a problem with durability. That is, in order to manufacture a constant velocity joint boot with a polyester-based resin that is hard and brittle and lacks flexibility, in order to satisfy the flexibility required for the constant velocity joint boot, It is necessary to form the part in multiple stages.
  • thermoplastic resin also known are resin boots manufactured by injection molding of thermoplastic resin (see, for example, Patent Documents 2 to 5).
  • resin boots manufactured by injection molding of thermoplastic resin see, for example, Patent Documents 2 to 5.
  • a molding die comprising a cavity die divided so as to be openable and closable and a core die disposed in the cavity die is used.
  • an injection nozzle 104 is provided in a molding space 103 formed by a cavity mold 101 consisting of a pair of split molds 101a and 101b and a core mold 102.
  • a molten thermoplastic resin is injected to form a hollow molded product P with one end closed.
  • the cavity mold 101 (101a, 101b) is opened, and it is externally fitted to the core mold 102 from the air blowing hole 105 provided in the core mold 102.
  • High-pressure air is blown into the hollow molded product P, and the hollow molded product P is expanded using the elastic deformation of the bellows portion of the hollow molded product P and extruded from the core mold 102.
  • the outer mold (cavity mold) and the core mold are preliminarily set to dimensions that are compressed by an amount corresponding to the extension of the final molded product dimension based on the height direction of the molded product, and then molded, separated.
  • a method for enlarging a molded product to a predetermined size after molding has been proposed (refer to Patent Document 2).
  • Patent Document 2 A method for enlarging a molded product to a predetermined size after molding has been proposed (refer to Patent Document 2).
  • Patent Document 2 A method for enlarging a molded product to a predetermined size after molding has been proposed (refer to Patent Document 2).
  • Patent Document 2 A method for enlarging a molded product to a predetermined size after molding has been proposed (refer to Patent Document 2).
  • Patent Document 2 a method of molding into a size that is compressed by the size corresponding to the elongation at the time of demolding.
  • the third step of obtaining the target boot by sucking the gas present inside from the inside of the preformed body through the communication port formed in the closed member and holding it in that state for a predetermined time See Patent Document 4;.
  • the method of adjusting the dimensions by applying external force to the molded product after molding does not only cause distortion due to stress in the molded product, which may change the size after manufacturing, but also the manufacturing process. Becomes complicated.
  • a molding space 103 formed from a cavity mold 101 and a core mold 102 as shown in FIG.
  • a flat gate 106A, 106B called direct gate or disk gate as shown in FIGS. 16 (a) and 16 (b)
  • the molten thermoplastic resin was injected into the molding space 103 via As shown in FIGS. 16 (a) and 16 (b), the planar gates 106A and 106B have a corner X and an injected resin material M on the inner surface of the mold as shown in FIGS.
  • the thickness of the part c (the gate 106A, 106B in the mold) is increased and the breakage is prevented, it is blown onto the inner surface of the flat lid c part and is pressed into the molded product P. There is a risk that the mold will not be uniformly distributed between the core mold 102 and the molded product P, and a demolding failure in which only one side of the molded product P is removed from the core mold 102 may occur.
  • the thickness of the bellows portion is thin, the centrifugal force during rotation is reduced. There is a risk of cracks in the peaks and valleys where stress is concentrated due to force, and the boots may be damaged, or the boots may expand and touch the surroundings.
  • the thickness of the valley 5 and the peak 6 shown in FIG. 10 may be increased. Strength If the thickness of the bellows part 4 is increased, the bellows part 4 becomes hard, which causes problems in flexibility and durability.
  • a cylindrical hollow molded article having a bellows portion is excellent in flexibility, like a thermoplastic resin, particularly a thermoplastic elastomer, and has a joint boot. It was difficult to mold a suitable resin material strength. Therefore, at present, chloroprene rubber, which is a vulcanized rubber, that cannot be recycled is mainly used.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 4 92166
  • Patent Document 2 JP-A-6-190878
  • Patent Document 3 Japanese Patent Laid-Open No. 10-73162
  • Patent Document 4 Japanese Patent Laid-Open No. 11-257490
  • Patent Document 5 Japanese Patent Laid-Open No. 2003-329059
  • Patent Document 6 Japanese Patent Laid-Open No. 2001-116057
  • the present invention manufactures a hollow cylindrical molded article, particularly a hollow molded article having a bellows portion, such as a constant velocity joint boot, by injection molding of thermoplastic resin.
  • a hollow molded product that has a good appearance without causing uneven flow of resin during molding, is small in deformation when demolded by high-pressure air, has excellent dimensional accuracy and dimensional stability, and can recycle the force.
  • the purpose is to enable production with high productivity.
  • the present invention also relates to a boot made of a resin manufactured by injection molding of a thermoplastic elastomer resin, which is a material having excellent flexibility, and excellent in durability without impairing the flexibility of the thermoplastic elastomer. It is intended to provide boots made of.
  • the present invention is to provide a rosin boot that is excellent in flexibility and durability even when the bellows portion is thin, and can be used as a constant velocity joint boot even under severe conditions.
  • the present inventor has found that when a cylindrical hollow molded product having a bellows portion is manufactured by injection molding of thermoplastic resin, By adopting a dome-shaped gate as a gate for injecting molten thermoplastic resin into the molding space of the mold, there is no uneven flow of the resin during molding, and the dome-shaped gate portion at the time of demolding By blowing high-pressure air onto the part of the dome-shaped lid that is molded into a uniform pressure, the pressure of the high-pressure air blown into the molded product acts uniformly inside the molded product, and the core mold force is easily removed. The knowledge that it was moldable was obtained, and the present invention was completed.
  • the method for injection molding a hollow molded product according to the present invention includes a mold that includes a cavity mold that can be opened and closed and a core mold that is disposed in the cavity mold.
  • An injection molding method in which a molten thermoplastic resin is injected and filled into a molding space formed between a cavity mold and a core mold to produce a cylindrical hollow molded product opened at both ends.
  • An axial direction of the molded product from one opening edge of the hollow molded product molded in the molding space A thermoplastic resin melted in the axial direction of the hollow molded product to be molded is injected from one point of the apex of the dome-shaped gate provided in communication with the molding space of the mold so as to protrude outward.
  • thermoplastic resin is injected and filled into the molding space through the dome-shaped gate to form a hollow molded product with one end closed.
  • the cavity mold is opened and the core is opened.
  • the apex partial force of the dome-shaped gate in the core mold is blown out in the axial direction of the molded product to take out the molded product from the core mold. It is characterized by that.
  • Preferred embodiments of the injection molding method according to the present invention are as follows.
  • the dome-shaped gate has a substantially hemispherical shape, and molten thermoplastic resin is injected from an injection hole provided at the apex of the substantially hemispherical gate.
  • the molten thermoplastic resin is injected and filled from the dome-shaped gate into the molding space in the axial direction of the molded product molded in the molding space.
  • the hollow molded article includes a pair of annular mounting portions that are open at both ends, and a bellows portion that integrally connects the two.
  • one of the pair of mounting portions has a larger diameter than the other, and into the molding space via a dome-shaped gate provided at an opening edge on the small-diameter mounting portion side in the molding die. Injection and filling with molten thermoplastic resin.
  • the hollow molded article is a constant velocity joint boot including a large-diameter attachment portion attached to an outer case, a small-diameter attachment portion attached to a shaft, and a bellows portion integrally connecting the two.
  • thermoplastic resin is a thermoplastic elastomer.
  • thermoplastic elastomer resin contains an acrylic block copolymer (A).
  • thermoplastic elastomer resin is a thermoplastic elastomer composition containing an acrylic block copolymer (A) and an olefin thermoplastic elastomer (B).
  • thermoplastic elastomer Acrylic block copolymer (A) 50 to 600 parts by weight of olefin-based thermoplastic elastomer (B) and compatibilizer (C) 5 to 5 per 100 parts by weight
  • the acrylic block copolymer (A) force 50 to 90 times the acrylic polymer block (a)
  • the methacrylic polymer block (b) is contained in an amount of 50%: LO wt%.
  • At least one of the acrylic polymer block (a) and the methacrylic polymer block (b) has a reactive functional group (c).
  • EPolefin rubber or acrylonitrile-butadiene rubber is dynamically crosslinked in the olefin-based thermoplastic elastomer (B) olefin resin.
  • the compatibilizer (C) is an olefin-based thermoplastic resin containing an epoxy group.
  • an injection mold for a hollow molded product includes a cavity mold that is divided so as to be openable and closable, and a core mold that is disposed in the cavity mold.
  • a dome-shaped gate is provided so as to protrude from the molding space to the outside in the axial direction of the molded product molded in the molding space, and one cavity mold is positioned at the apex of the dome-shaped gate.
  • one cavity mold is positioned at the apex of the dome-shaped gate.
  • An openable and closable outlet that communicates with the high-pressure air supply means is provided, and a molten thermoplastic resin is injected into the molding space from the injection hole through the dome-shaped gate and filled into a hollow molded product.
  • the cavity mold is opened and the blowout opening is opened, and high pressure air is blown from the high pressure air supply means to the inside of the hollow molded article through the blowout opening, and the core mold force is also taken out. It is configured as described above.
  • Preferred embodiments of the injection mold according to the present invention include the following.
  • the dome-shaped gate is substantially hemispherical, and an injection hole extending in the axial direction of the hollow molded article to be molded is provided at the apex of the substantially hemispherical gate.
  • An opening edge to the molding space in the dome-shaped gate is formed so as to be in the same direction as the axial direction of the molded product molded in the molding space.
  • a vent hole penetrating in the axial direction of the core mold and connected to the high-pressure air supply means is provided in the axial center portion of the core mold, and the tip end portion of the vent hole serves as the outlet, and the tip end is provided in the vent hole.
  • An opening / closing shaft that slides in the axial direction of the core mold is provided facing the dome-shaped gate, and the air outlet can be opened and closed by the opening / closing shaft.
  • One or a plurality of ventilation grooves extending in the axial direction are provided on the inner peripheral surface inside the ventilation hole, and the opening / closing shaft is retracted until its tip comes to the position where the ventilation groove is provided to open the air outlet. At the same time, high-pressure air can be blown into the molded product from the ventilation hole through the ventilation groove and the outlet.
  • a molding die for molding a hollow molded product including a pair of annular mounting portions opened at both ends and a bellows portion integrally connecting the two.
  • a molding die for molding a constant velocity joint boot including a large-diameter attachment portion attached to an outer case, a small-diameter attachment portion attached to a shaft, and a bellows portion integrally connecting the two.
  • the first resin-made boot according to the present invention includes a pair of attachment portions opened at both ends and a bellows portion integrally connecting the two by the injection molding method according to the present invention.
  • each valley portion in the bellows portion is On the other hand, it is characterized in that it is formed to be equal to or thicker than the adjacent peak portion near the gate side mounting portion, and at least part of the valley portion is formed thicker than the adjacent peak portion.
  • the bellows portion refers to a shape in which a convex portion projecting toward the outside of the boot and a concave portion projecting toward the inside of the boot are alternately continued in the longitudinal section of the boot.
  • each ridge and groove adjacent to each other on the outer peripheral surface of the boot are spirally continuous. Including those formed as a result.
  • the peak portion is a convex portion (ridge portion) of the bellows portion
  • the valley portion is a concave portion (concave portion) of the bellows portion.
  • one of the pair of attachment portions has a larger diameter than the other, and a thermoplastic elastomer is formed from a gate provided on the small diameter attachment portion side in the molding die. It is formed by injecting a single fat.
  • a thermoplastic elastomer is formed from a gate provided on the small diameter attachment portion side in the molding die. It is formed by injecting a single fat.
  • Particularly preferred embodiments include a large diameter attachment that is attached to the outer case, a small diameter attachment that is attached to the shaft, It is a boot for constant velocity joints provided with the bellows part which connects both together.
  • the present inventors in the resin-made boots injection-molded with thermoplastic elastomer resin, by the injection molding method according to the present invention described above, A large-diameter mounting part and a small-diameter mounting part are provided, and a bellows part formed by integrally connecting the two parts is provided.
  • a large-diameter mounting part and a small-diameter mounting part are provided, and a bellows part formed by integrally connecting the two parts is provided.
  • the second resin boot according to the present invention comprises a pair of attachment portions opened at both ends of a large diameter attachment portion and a small diameter attachment portion, and the large diameter attachment portion and the small diameter attachment portion. And a bellows portion that is integrally connected and has a bellows portion that gradually decreases in diameter from the large-diameter attachment portion toward the small-diameter attachment portion.
  • the inner diameter d of the valley closest to the large-diameter mounting part is larger than the opening diameter D on the small-diameter mounting part side in the bellows part.
  • the radius of curvature of the valley closest to the large diameter mounting part is 2mn! It is characterized by ⁇ 10mm.
  • the curvature radius of the above-mentioned valley portion is the curvature radius of the inner surface of the concave portion protruding toward the inside of the bellows portion in the longitudinal section of the boot.
  • the outer diameter of the peak portion closest to the large-diameter mounting portion is smaller than the opening diameter D on the large-diameter mounting portion side in the bellows portion. Also, the bellows part
  • the wall thickness is preferably 3 mm or less. Furthermore, it is more preferable to form a cylindrical peripheral wall portion extending in parallel with the shaft core at the opening edge of the bellows portion on the large diameter attachment portion side.
  • thermoplastic elastomer resin used in the injection molding of the resin boot according to the present invention, but (A) one containing an acrylic block copolymer is preferred. Furthermore, a thermoplastic elastomer containing (A) an acrylic block copolymer and (B) an olefin thermoplastic elastomer is preferred. In particular, a thermoplastic elastomer composition containing (C) a compatibilizer in addition to (A) and (B) is preferred. Preferred embodiments of the thermoplastic elastomer composition include the following.
  • (A) 50 to 600 parts by weight of (olefin) thermoplastic elastomer and (C) 5 to 50 parts by weight of a compatibilizing agent are included with respect to 100 parts by weight of the acrylic block copolymer.
  • (A) Acrylic block copolymer force
  • the acrylic block (a) and the methacrylic polymer block (b) have a reactive functional group (c) in at least one of the polymer blocks.
  • the reactive functional group (c) in the acrylic block copolymer (A) has the general formula (1):
  • R 1 is a hydrogen atom or a methyl group, and may be the same or different from each other, p is an integer of 0 or 1, q is an integer of 0 to 3) and a unit (c2) containing Z or a carboxyl group.
  • composition strength of thermoplastic elastomer The acrylic block copolymer (A) contains 0.1 to 50% by weight of units (c2) containing a carboxyl group.
  • the acrylic block copolymer (A) is a block copolymer produced by atom transfer radical polymerization.
  • EPolefin rubber or acrylonitrile-butadiene rubber is dynamically crosslinked in the olefin-based thermoplastic elastomer (B) olefin resin.
  • the compatibilizer (C) is an olefin-based thermoplastic resin containing an epoxy group.
  • the molten thermoplastic resin is smoothly filled into the molding space from the dome-shaped gate of the mold, and the flow of the resin is disturbed to impair the appearance of the molded product. There is no.
  • the hollow molded product externally fitted to the core mold is demolded by blowing high-pressure air from the apex portion of the dome-shaped gate in the core mold. Gate partial force After the injected air is blown onto the dome-shaped lid part to be molded, it is smoothly blown along the inner surface of the dome-shaped lid part and enters between the core mold and the hollow molded product. The pressure of high-pressure air acts uniformly inside the molded product, and the hollow molded product can be easily removed from the core mold.
  • the mold structure is not complicated and the work is not complicated as in the case of using a split core mold, and a good hollow molded product can be manufactured with high productivity.
  • the hollow molded product molded with the dome-shaped lid as described above has the dome-shaped lid portion and the runner portion formed in a connected state cut off after molding. , Become the target product.
  • the vertical cross-sectional shape of the dome-shaped gate is substantially hemispherical and molten thermoplastic resin is injected from an injection hole provided at the apex of the approximately hemispherical gate, the flow of injected resin is It is possible to more reliably suppress turbulent flow).
  • an opening edge to the molding space is formed so as to be in the same direction as the axial direction of the molded product formed in the molding space, and the molten thermoplastic resin is formed.
  • the resin is injected from the dome-shaped gate into the molding space and filled in the axial direction of the molded product molded in the molding space, the resin is injected linearly from the dome-shaped gate into the molding space. Turbulent flow that occurs in the flow of rosin) can be suppressed more reliably.
  • a vent hole penetrating in the axial direction of the core mold of the core mold and connected to a high-pressure air supply means is provided, and the tip of the vent hole serves as the outlet, and the inside of the vent hole
  • an opening / closing shaft that slides in the axial direction of the core mold is provided with the tip facing the dome-shaped gate, and the blowout port can be opened / closed by the opening / closing shaft.
  • One or more ventilation grooves extending in the axial direction are provided on the inner peripheral surface inside the ventilation hole, and the opening and closing shaft is retracted until its tip is located at the position where the ventilation groove is provided.
  • the injection molding method and the molding die of the present invention is a hollow molded product having a bellows part, the molded product can be easily removed from the core mold, so a pair of annular mounting parts opened at both ends; It is suitable for molding of a hollow molded product having a bellows part that connects both together.
  • a dome-shaped gate provided at the opening edge of the small-diameter mounting portion in the molding die is used.
  • the molten thermoplastic resin is injected and filled into the molding space, the molten thermoplastic resin injected from the dome-shaped gate is smoothly filled into the molding space, and no well line is generated. A good molded product can be obtained.
  • the injection molding method and the injection mold of the present invention include a large-diameter attachment portion attached to the outer case and a small-diameter attachment portion attached to the shaft by injection molding of thermoplastic resin.
  • This is suitable for manufacturing a constant velocity joint boot including a bellows portion that integrally connects the two.
  • the bellows-shaped boot is formed by injection molding using a thermoplastic resin such as a thermoplastic elastomer resin
  • a thermoplastic resin such as a thermoplastic elastomer resin
  • a weld line by injection molding is used. Is relatively rare.
  • the boot made of a flexible thermoplastic elastomer resin is thin in the bellows part and used in a rotating part such as a constant velocity joint boot, the boot expands to the outside due to centrifugal force. However, it is easy to break.
  • the bellows part In order to prevent this, if the bellows part is formed thick, expansion due to centrifugal force during rotation can be prevented, but the flexibility of the bellows part is lost, and it is bent violently like a constant velocity joint boot If there is a problem with durability. In addition, if only the peak portion is formed thick, the thick peak portion can prevent swelling due to centrifugal force during rotation. If the thickness of the part is reduced, the flexibility of the bellows part can be secured. However, if only the crest is thickened, the resin injected into the molding space of the mold during the boot molding will flow from the thick crest to the adjacent thin trough. Become.
  • the flow of the resin is disturbed due to the resistance of the inner wall of the molding space of the mold, and the continuity of the resin injected and filled into the molding space is lost, resulting in weld lines that cause cracks and breakage. It becomes easy to do.
  • the first resin-made boot according to the present invention forms at least a part of the valley portion in the bellows portion thickly, expansion due to centrifugal force during rotation is prevented.
  • the thickness of the mountain portion is thin, the flexibility of the bellows portion is not impaired.
  • each trough is equal to or greater than the thickness of the adjacent peak near the mounting part on the gate side, so that the grease injected from the gate into the molding space Is filled and flows smoothly from the crest to a thick trough having a molding space equal to or larger than the crest while maintaining continuity.
  • the resin is filled toward the valley, a weld line that causes cracks and breakage of the molded product does not occur, and a resin boot having excellent durability can be obtained.
  • a resin-made boot such as a constant velocity joint boot is formed such that the diameter of the bellows portion is sequentially reduced from the large-diameter mounting portion toward the small-diameter mounting portion.
  • the second resin boot according to the present invention has an inner diameter d of the valley portion having the largest inner diameter among the valley portions in the bellows portion and closest to the large diameter attachment portion, and opening on the small diameter attachment portion side in the bellows portion. Larger than D and bellows
  • the opening diameter is smaller than 60% of the opening D on the large-diameter mounting part side. Large diameter mounting
  • the inner diameters of the other valley portions By reducing the inner diameter d of the valley portion closest to the portion, the inner diameters of the other valley portions, whose diameters are gradually reduced by urging the small diameter mounting portion, are inevitably reduced.
  • the smaller the inner diameter of the valley of each step the smaller the angular velocity during rotation, and the smaller the centrifugal force acting on each valley. As a result, the boots are also resistant to swelling during rotation.
  • the largest centrifugal force acts by rotation because the valley portion is closest to the large-diameter mounting portion and the valley portion has the largest inner diameter. Therefore, by increasing the curvature radius of the trough to 2 to LOmm, the stress concentrated on the trough is dispersed by the centrifugal force during rotation, and cracking due to bending can be prevented. Also, the curvature of the valley As the radius increases, the angle between the two slopes sandwiching the valley increases with respect to the boot axis, and the angle between the direction of centrifugal force acting (direction perpendicular to the boot axis) and the inclined surface decreases. The bellows part is less likely to expand due to the centrifugal force during rotation, improving the durability of the boot.
  • the centrifugal force to be reduced is also much smaller.
  • the boots are also resistant to swelling during rotation.
  • the second bellows boot of the present invention has a small inner diameter at the bellows or peak of the bellows portion and is difficult to expand during rotation, the thickness of the bellows portion is reduced to 3 mm or less. However, the durability required as a constant velocity joint boot can be satisfied. Further, if the thickness of the bellows portion is reduced in this way, it is lightweight and excellent in flexibility, and the amount of thermoplastic elastomer resin used for molding is small, and the manufacturing cost can be reduced.
  • the inner surface of the bellows portion 4 can be prevented from touching when the joint is bent, and the inner diameter of the valley portion 5c closest to the large-diameter mounting portion 3 can be reduced to suppress the expansion of the bellows portion 4 during rotation. .
  • thermoplastic elastomer resin used in the injection molding method and resin boot of the present invention is a thermoplastic elastomer composition containing the acrylic block copolymer (A)
  • acrylic elastomer A thermoplastic elastomer composition containing a block copolymer (A) and an olefin-based thermoplastic elastomer (B) is excellent in flexibility and durability, and is ideal for constant velocity joint boots, etc. Molded products such as rosin boots can be obtained.
  • the composition strength of the thermoplastic elastomer is 100 parts by weight, and the olefin-based thermoplastic elastomer (B) is 50 to 600 parts by weight and the compatibilizer (C) is 5 to 50 parts by weight. By including the part, it is possible to obtain a molded article having more flexibility and durability. Furthermore, when the acrylic block copolymer (A) 1S acrylic polymer block (a) is contained in an amount of 50 to 90% by weight and the methacrylic polymer block (b) is contained in an amount of 50 to L0% by weight, A molded product having further excellent softness and durability can be obtained.
  • the molded product has excellent heat resistance. Goods can be obtained.
  • the olefin-based thermoplastic elastomer (B) is obtained by dynamically crosslinking EPDM rubber or acrylonitrile-butadiene rubber in olefin resin, it has excellent rubber properties while having thermoplasticity. Compressed permanent set, low temperature z high elastic change at high temperature ⁇ Molded product can be obtained.
  • the compatibilizing agent (C) is an epoxy-based thermoplastic resin containing an epoxy group
  • the epoxy group of the polyolefin-based thermoplastic resin is an acrylic block copolymer (A). It is preferable because it reacts with units (c) such as polymethacrylic anhydride to better mix the acrylic block copolymer (A) and the olefin thermoplastic elastomer (B).
  • FIG. 1 is a cross-sectional view of an injection mold.
  • FIG. 2 is a front view of a split surface of one split mold of the cavity mold.
  • FIG. 3 is a front view of the split surface of the other split mold of the cavity mold.
  • FIG. 4 is a cross-sectional view of an outer mold of a core mold.
  • FIG. 5 is a cross-sectional view of a mold in a state in which the resin is injected.
  • FIG. 6 is a cross-sectional view at a different angle of the mold in a state where the resin is injected.
  • FIG. 7 is an enlarged cross-sectional view for explaining the flow of grease in the dome-shaped gate.
  • FIG. 8 is a cross-sectional view showing a state where the mold is opened after molding.
  • FIG. 9 is a cross-sectional view showing how a molded product is taken out from the core mold with high-pressure air.
  • FIG. 10 is a cross-sectional view of a greave boot of Example 1.
  • FIG. 11 is a cross-sectional view of a resin-made boot of Example 2.
  • FIG. 12 (a) is a longitudinal sectional view of a constant velocity joint boot according to an embodiment (Example 3) of the second resinous boot of the present invention, and (b) and (c) are FIG. 5 is an enlarged cross-sectional view of a trough that is closest to the largest-diameter mounting portion.
  • FIG. 13 is a bottom view of the resin-made boot shown in FIG.
  • FIG. 14 is a cross-sectional view of an injection mold for molding a resin-made boot of Example 3.
  • FIG. 15 shows a conventional injection molding method and an injection mold, where (a) is a cross-sectional view showing a state before molding, and (b) is a state of demolding after molding.
  • FIG. 16 shows a conventional injection molding method and injection mold, wherein (a) and (b) are enlarged cross-sectional views of the injection gate portion showing the flow of grease, and (b) is the removal of the molded product by high-pressure air. It is an enlarged sectional view showing a state at the time of molding.
  • An injection molding method and an injection mold according to the present invention include, for example, a resin-made boot having a bellows portion, such as a constant-velocity joint boot, and an injection molding of thermoplastic elastomer. Used when manufacturing.
  • the injection mold of the present invention is, for example, as shown in FIG. 1, a pair of a mold 10A and a mold 10 which are divided into two such that they can be opened and closed, and a mold 10 of the mold.
  • the split mold 1 OA and the core mold 20 arranged in a state sandwiched between 10B.
  • a thermoplastic elastomer resin is injected and filled into a cylindrical molding space 30 formed between the cavity mold 10 and the core mold 20, and a cylindrical hollow molded product such as a joint boot is molded.
  • the split molds 10A and 10B of the cavity mold 10 are fixed to a base plate (not shown) located on the back side thereof, and can be opened and closed by moving left and right together with the base plate.
  • the core mold 20 is fixed to a base plate (not shown) located on the upper side thereof.
  • This injection mold includes, for example, an annular large-diameter attachment portion 3 attached to an outer case and an annular small-diameter attachment portion 2 attached to a shaft as shown in FIG. It is used for injection molding of a greave boot 1 such as a constant velocity joint boot having a bellows portion 4 to be tied.
  • a greave boot 1 such as a constant velocity joint boot having a bellows portion 4 to be tied.
  • the pair of split molds 10A and 10B that make up the cavity mold 10 have a substantially symmetrical shape, and the shape of the boot 1 molded on the opposing split surfaces 11A and 11B. Accordingly, molding recesses 30A and 30B constituting the outer peripheral surface of the molding space 30 are formed.
  • the recesses 30A and 30B are formed in a shape in which the small-diameter mounting portion 2 of the boot 1 is positioned below the dividing surfaces 11A and 11B and expands upward in a bellows shape.
  • an approximately 1Z4 spherical gate recess 31A, 3 IB is formed below each recess 30A, 30B. Therefore, when the split molds 10A and 10B are closed together, the outer peripheral surface of the hemispherical dome-shaped gate 40 is constituted by the gate recesses 31A and 31B.
  • Grease extending in the same direction as the shaft core (X shown in Fig.
  • the core mold 20 includes a hollow outer mold 20A that forms the inner peripheral surface of the molding space 30 according to the inner surface shape of the boot 1, and a downward-facing substantially frustoconical middle mold 20B that is fitted into the outer mold 20A. Are fixed to the lower surface of the substrate 20C with bolts (not shown). As shown in FIGS. 1 and 4, a dome-shaped convex portion 23 that forms the inner peripheral surface of the dome-shaped gate 40 is formed at the lower end portion of the outer mold 20A. A vent hole 24 is formed so as to penetrate the outer molds 20A and 20B of the core mold 20 and the substrate 20C from the center end of the dome-shaped convex part 23.
  • the lower end opening portion of the vent hole 24 opens to the dome-shaped gate 40, and serves as a blowout port 21 that blows out air toward the inside of the molded hollow molded product.
  • An opening / closing shaft 22 that can be instantaneously slid by a solenoid (not shown) or the like is provided in the vent hole 24. The opening / closing shaft 22 closes the outlet 21 when the thermoplastic resin is sprayed so that the molten thermoplastic resin sprayed from the inlet 41 does not enter the vent hole 24.
  • the open / close shaft 22 slides up (retreats) in the air vent 24, and high-pressure air supplied with force such as an air compressor (not shown) passes through the air vent 24. Then, the air is blown from the outlet 21 toward the inner surface of the molded product, and the molded product is extruded from the core mold 20.
  • the shape of the dome-shaped gate 40 is not limited, and there is no turbulence in the flow of injected resin. Further, the dome-shaped gate 40 is molded from the outlet 21 into the molded product, specifically, the dome-shaped gate 40. Any shape may be used as long as the high-pressure air blown toward the inner surface of the portion to be the lid of the molded product acts uniformly on the inner surface of the molded product. However, as shown in FIG. 7, when the dome-shaped gate 40 has a substantially hemispherical shape and the molten thermoplastic resin M is injected from the injection hole 41 provided at the apex thereof, the flow of the resin M (in FIG. 7) Indicated by a dashed-dotted arrow)), it is possible to effectively suppress the occurrence of turbulent flow), and there is no uneven flow or weld line of the resin, and excellent appearance and mechanical properties. Can be obtained.
  • the opening edge 40a to the molding space 30 in the dome-shaped gate 40 extends substantially in a cylinder extending in a direction parallel to the axial center (X shown in FIG. 10) of the boot 1 molded in the molding space 30.
  • the force of the dome-shaped gate 40 is also linear. Therefore, since the resin is injected into the molding space 30, the turbulent flow generated in the flow of the resin can be more effectively suppressed.
  • a vent hole 24 penetrating in the axial direction and connected to a high-pressure air supply means such as a compressor is provided in the shaft core portion of the core mold 20.
  • the tip of the vent hole 24 is used as the air outlet 21 that opens to the dome-shaped gate 40, and the tip 22a faces the dome-shaped gate 40 in the vent hole 24 so that the axial direction of the core mold 20 is the same. If the opening / closing shaft 22 that slides on the opening / closing shaft 22 and the opening / closing port 22 can be opened / closed by the opening / closing shaft 22, when the molten thermoplastic resin is injected into the molding space 30, the blowing port 21 enters the vent hole 24. The resin can be surely prevented from entering.
  • the cavity mold 10 is opened, and at the same time, high-pressure air is blown into the molded boot molded product P so that the molded boot 1 is removed from the core mold. It can be quickly removed from 20 and can be made into a resinous boot 1 with good productivity.
  • the diameter of the portion 24a is reduced near the tip of the vent hole 24 of the core mold 20, and the vent hole 24 is formed on the inner peripheral surface of the small diameter portion 24a.
  • One or a plurality of ventilation grooves extending in the length direction, and in the example shown in the figure, four ventilation grooves 25 are provided, and as shown in FIG.
  • the opening / closing shaft 22 is provided, and the tip 22a is provided with a ventilation groove 25.
  • the air outlet 21 is opened until it reaches the position, and high-pressure air is blown from the air vent 24 through the air groove 25 and the air outlet 21 to the inside of the molded boot molded product P. It is possible to reliably prevent the intrusion of the resin into the outlet 21 during the injection of the molten thermoplastic resin into the inside.
  • a procedure for injection molding hollow resin articles, for example, resin-made boots such as constant-velocity joint boots, from thermoplastic resin such as a thermoplastic elastomer, using the injection mold as described above, is as follows. explain. First, as shown in FIG. 1, the split molds 10A and 10B of the cavity mold 10 are closed, and the core mold 20 is disposed in the cavity mold 10, and the cavity mold 10 and the core mold 20 are placed between them. A molding space 30 corresponding to a predetermined boot shape is formed. Next, from the injection molding machine (not shown) connected to the nozzle mounting part 43, as shown in FIGS. 5 and 6, the resin injection path 42, the injection port 41, the dome-shaped gate 40, and further into the molding space 30 are obtained.
  • a molten thermoplastic resin is injected and filled, and a hollow molded product whose one end is closed by a portion (indicated by symbol c in FIG. 9) that is a lid formed on the dome-shaped gate 40, for example, Mold boots.
  • the split molds 10A and 10B are opened to the left and right (Fig. 8), and at the same time, high-pressure air is blown against the inner surface of the portion c serving as the lid of the molded product P that is externally fitted to the core mold 20.
  • pressure is uniformly applied to the inner surface of the molded product P that is in close contact with the core mold 20 by the high-pressure air, and the molded product P expands instantaneously and the outer peripheral surface of the core mold 20 and the molded product P A gap is formed between the inner peripheral surface and the molded product P is pushed downward from the core mold 20 (FIG. 9).
  • FIG. 10 and FIG. 11 are longitudinal sectional views of the resinous resin boots 1 and 1A according to the embodiment of the present invention.
  • FIG. 12 (a) is a longitudinal cross-sectional view of a resinous boot 1B according to an embodiment of the second resinous boot of the present invention.
  • the boot 1 B is a boot for a constant velocity joint of an automobile, like the boots 1 and 1A.
  • These resin boots 1 have a generally frustoconical shape, for example, even if the mounting parts 2 and 3 at both ends are cylindrical boots having the same diameter, such as a shaft boot of a motorcycle.
  • the bellows portion 4 may be formed by alternately forming a plurality of independent ridges and recesses, or may be formed by spirally forming each one of the ridges and recesses.
  • the planar shape (transverse cross-sectional shape) of the attachment portions 2 and 3 and the bellows portion 4 at both ends may be a square shape or an elliptical shape. There is no particular limitation on the overall shape of the boot 1. Further, as shown in FIG.
  • the large-diameter mounting portion 4 has an inner peripheral surface so that it can be attached to a non-circular outer peripheral case having three concave portions such as a triport type constant velocity joint.
  • a non-circular shape in which a plurality of convex portions 7 are formed may be used.
  • three bellows 5 a to 5 c and three peaks 6 a to 6 c are formed on the bellows portion 4.
  • the number of valleys 5 and peaks 6 of the bellows part 4 is not particularly limited, but the number of peaks 6 is 3 to 3 in terms of the processability of injection molding and the expandability of the bellows part 4 during rotation. 5 is preferred. If the number of the peak portions 6 of the bellows portion 4 is less than three, the dimensional difference between the peak portions 4 and the valley portions 5 becomes large, and it may be difficult to remove the mold after injection molding.
  • the thickness of the bellows portion 4 becomes thin, and the bellows portion 4 expands during rotation or the pitch between the adjacent peak portions 6 becomes narrow.
  • the radius of curvature R of the part 5 becomes small, and stress due to centrifugal force concentrates during rotation, and cracks tend to occur.
  • the above-mentioned boots 1, 1A, IB made of thermoplastic resin are filled with thermoplastic elastomer into the molding space 30 of the mold from the gate 40 provided on one mounting portion (small-diameter mounting portion 2) side. It is formed by injection and filling.
  • the thickness of the bellows 4 of the boots 1 and 1A may be uniform as in the boot 1 shown in FIG. 10, but the thickness of the valleys 5 such as 5b and 5c as shown in the boot 1 A shown in FIG.
  • a small-diameter mounting portion that is a crest adjacent to the side where the gate 40 is provided with respect to the troughs 5b and 5c, that is, upstream of the flow of the resin injected from the gate 40 into the molding space 30.
  • the bellows part 4 has a force in which four peaks 6a to 6d and three valleys 5a to 5c are alternately formed.
  • the second valley portion 5ba, the third valley portion 5c, and the second valley portion 5c have the same thickness, and are formed thicker than the second peak portion 6b and the third peak portion 6c, respectively.
  • the molding space 30 is formed from the gate 40.
  • the thermoplastic elastomer resin M injected and filled inside is smoothly filled from the peak 6b to the valley 6b and further from the peak 6c to the valley 5c without losing continuity. Does not occur.
  • the second and third valleys 5b and 5c are formed thicker than the peak 6, the bellows 4 is prevented from expanding due to the centrifugal force during rotation. Since the thickness of the parts 6a to 6d can be reduced, the flexibility of the bellows part 4 is not impaired, and the durability is excellent.
  • the inner diameter d of the valley 5c closest to the largest diameter mounting portion 3 is set to the bellows portion 4.
  • the opening diameter on the large diameter mounting portion 3 side that is, the opening diameter D on the bellows portion 4 is larger than the opening diameter D on the small diameter mounting portion 2 side and the opening edge of the boot 1 Shaft core X
  • the boot 1B is formed so that the bellows part 4 is directed from the large diameter attachment part 3 to the small diameter attachment part 2 so that the diameter thereof, that is, the diameter of each valley part 5 and the peak part becomes smaller. Therefore, the smaller the inner diameter d of the valley portion 5c closest to the large-diameter mounting portion 3, the smaller the inner diameter d,
  • the inner diameters d and d of the valleys 5b and 5c of each step, which are successively formed, are inevitably smaller.
  • the inner diameter d of the valley portion 5c closest to the large-diameter mounting portion 3 is set to the bellows portion 4.
  • the boot 1B is excellent in durability to hardly expand during rotation.
  • the radius of curvature R of the valley 5c is increased from 2 to LOmm as shown in FIG. Due to the centrifugal force, the stress concentrated in the valley 5c is dispersed and cracking due to bending can be prevented.
  • the curvature radius of the valley 5c increases, the angle of the two inclined surfaces 4a and 4b sandwiching the valley 5c with respect to the boot axis X increases, and the direction of centrifugal force acting and the inclined surfaces 4a and 4b The inclination angle becomes smaller, and the inclined surfaces 4a and 4b expand due to the centrifugal force during rotation, so that the durability of the boot 1B is improved.
  • a cylindrical peripheral wall portion 8 extending in parallel to the axis X is formed on the edge portion on the large diameter attachment portion 3 side as shown in FIG. 12, and the upper peripheral edge 6d of the peripheral wall portion 8 is used as a base point.
  • the inclined surface 4b toward the valley 5c inward of the boot compared to the one shown in FIGS. 10 and 11, the projection 6d projecting outward from the opening edge on the large-diameter mounting part 3 side. Even if the inner diameter d of the valley portion 5c closest to the large-diameter mounting portion 3 can be reduced, the valley portion 5c has a large diameter.
  • the inner surface of the valley part 5 becomes difficult to touch the shaft etc. when the joint is bent, and the inner diameter d of the valley part 5c is reduced.
  • the centrifugal force acting on the rotation can be reduced to suppress the expansion of the bellows part 4 during the rotation.
  • the resin used is not particularly limited, but thermoplastic resin is preferred. Furthermore, when molding a resin boot such as a joint boot, a thermoplastic elastomer is preferred. Thermoplastic elastomers are not particularly limited, but for example for automotive constant velocity joints In the case of boots, in addition to moldability, acrylic block copolymers with excellent heat resistance, oil resistance, compression set resistance, and low tensile set are preferred. A thermoplastic elastomer resin is preferred. In addition, for example, thermoplastic polyurethane (TPU), chlorine-containing polymer, polysalt-vinylidene (PVDC), poly-salt-bule (PVC), chlorinated polyethylene (CPE), fluorine-containing polymer, polyvinyl fluoride.
  • TPU thermoplastic polyurethane
  • PVDC polysalt-vinylidene
  • PVC poly-salt-bule
  • CPE chlorinated polyethylene
  • fluorine-containing polymer polyvinyl fluoride.
  • -Thermoplastics such as redene (PDVF), polyesters, acrylonitrile-butadiene-styrene copolymer (ABS), styrene-acrylonitrile copolymer (SAN), styrene-maleic anhydride copolymer (SMA), polyacetals, polycarbonates, polyphenol-oxide A polymer can also be used.
  • PDVF redene
  • ABS acrylonitrile-butadiene-styrene copolymer
  • SAN styrene-acrylonitrile copolymer
  • SMA styrene-maleic anhydride copolymer
  • polyacetals polycarbonates
  • polyphenol-oxide A polymer can also be used.
  • thermoplastic elastomer composition comprising (A) an acrylic block copolymer and (B) an polyolefin thermoplastic elastomer is preferred as the thermoplastic elastomer resin of the polyolefin X acrylic composite. Furthermore, a thermoplastic elastomer composition containing (C) a compatibilizing agent in addition to (A) and (B) is more preferred.
  • acrylic block copolymer (A) an acrylic polymer block (a) and a methacrylic polymer block (b) are preferred.
  • the structure of the acrylic block copolymer (A) depends on the processing characteristics and mechanical properties of linear block copolymers, branched (star) block copolymers, and mixtures of these. You can use it properly. From the viewpoint of cost and ease of polymerization, a linear block copolymer is preferred.
  • the structure of the linear block copolymer is that the acrylic polymer block (a) and the methacrylic polymer block (b) are represented by the general formula: (a—b) and general formula: b—
  • a compound represented by (a-b), general formula: (a-b) -a (wherein n is an integer of 1 to 3) is preferred.
  • an a-b type diblock copolymer, a b-a-b type triblock copolymer, or these Prefer the mixture.
  • the acrylic block copolymer (A) includes at least the polymer blocks (a) and (b).
  • One of the polymer blocks preferably has a reactive functional group (C).
  • the reactive functional group (c) the general formula (1):
  • R 1 is a hydrogen atom or a methyl group, which may be the same or different from each other, p is an integer of 0 or 1, q is an integer of 0 to 3
  • a unit (cl) and a unit containing a Z or carboxyl group (c2) are preferred, and at least one of the unit (c) 1S acrylic polymer block (a) and methacrylic polymer block (b) One or more per polymer block should be included.
  • the mode in which the units (c) are polymerized may be random copolymerization or block copolymerization.
  • a block copolymer containing the unit (c) is shown by taking a b-a-b type triblock copolymer as an example, and (bZc) -a-b type, (bZc)- a— (bZc) type, cb—a—b type, cb—a—b—c type, b— (a / c) —b type, b—a—cb type, b—c—a—b type, etc. And these can be offset! /
  • (aZc) means that unit (c) is contained in block (a) !
  • (bZc) means that unit (c) is contained in block (b).
  • C -a-and a- c indicate that the unit (c) is connected to the end of the block (a).
  • forces such as (a / c), (bZc), c—a—, a—c, etc. These are all acrylic polymer blocks ( a ) or methacrylic polymer blocks (b). .
  • the number average molecular weight of the acrylic block copolymer (A) is preferably 30000 to 500000, more preferably 40000 to 400000, and more preferably 50000 to 300000! Akujinole If the molecular weight of the lock copolymer (A) is less than 30,000, sufficient mechanical properties as an elastomer may not be exhibited, and if it exceeds 500,000, the processing characteristics may deteriorate.
  • the ratio (MwZMn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the acrylic block copolymer (A) is preferably 1 to 2, and more preferably 1 to 1.8.
  • the number average molecular weight (Mn) and the weight average molecular weight (Mw) are those obtained by gel permeation chromatography and using a black mouth form as a mobile phase to obtain a molecular weight in terms of polystyrene.
  • the composition ratio of the acrylic polymer block (a) to the methacrylic polymer block (b) constituting the acrylic block copolymer (A) is required for the physical properties required during processing of the composition. Determine the moldability and the required molecular weight for the acrylic polymer block (a) and the methacrylic polymer block (b).
  • the acrylic polymer block ( a ) is 50 to 90% by weight, more preferably 50 to 50%.
  • methacrylic polymer block (b) is 50 to 10% by weight, further 50 to 20% by weight, in particular 50 to 30% by weight.
  • the ratio of the acrylic polymer block (a) is 50 wt% Yori not small, the mechanical properties of the elastomer and foremost, lowered particularly elongation at break, there is the flexibility is lowered, from 90 weight 0/0 If it is large, rubber elasticity at high temperatures may be lowered.
  • the relationship between the glass transition temperature (Tg) of the acrylic polymer block (a) and the methacrylic polymer block (b) is that the glass transition temperature of the acrylic polymer block (a) is Tg, a
  • Tg can be roughly determined by using the following Fox formula and the monomer weight ratio in each polymer block.
  • w 1, w 2,..., W each represent a weight ratio of polymerized monomers.
  • the acrylic polymer block (a) contains 50 to 100 weight units of an acrylate ester in the whole. / 0 , preferably 60 to: L00% by weight, 0 to 50% by weight, preferably 0 to 40% by weight of monomers having functional groups that serve as precursors of the unit (c), and these It is preferable to contain 0 to 50% by weight, and further 0 to 25% by weight, of other vinyl monomers copolymerizable with. If the proportion of the unit containing the acrylate ester is less than 50% by weight, the physical properties, particularly the elongation of the tensile properties, which are characteristic when using the acrylate ester, may be reduced by / J.
  • the molecular weight of the acrylic polymer block (a) can be determined by determining the required elastic modulus and rubber elasticity, and the time required for the polymerization.
  • An example of the range of the number average molecular weight (M) of the acrylic polymer block (a) is preferably M> 3000, more preferably M> 5000,
  • the number average molecular weight (M) of the acrylic polymer block (a) is smaller than the above range.
  • the tensile elongation of the molded product is lowered.
  • the upper limit of the number average molecular weight (M) of the methacrylic polymer block (a) if the number average molecular weight (M) is large, the polymerization time tends to be long.
  • it may be set according to the required productivity, but is preferably 500000 or less, and more preferably 300000 or less.
  • acrylic ester constituting the acrylic polymer block (a) for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-acrylate Acrylics such as pentyl, n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, nor acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, etc. Acid aliphatic hydrocarbon (eg, alkyl having 1 to 18 carbon atoms) ester; Acrylic acid cycloaliphatic hydrocarbon ester such as cyclohexyl acrylate and isoborn acrylate;
  • Acrylic acid aromatic hydrocarbon esters such as acrylic acid acrylic and acrylic acid acrylic acid; aralkyl acrylates such as benzyl acrylate; acrylic acid and ether such as 2-methoxyethyl acrylate and 3-methoxybutyl acrylate An ester with a functional group-containing alcohol having functional oxygen;
  • Trifluoromethylmethyl acrylate 2-trifluoromethylethyl acrylate, 2-perfluoroethylethyl acrylate, 2-perfluoroethyl 2-acrylobutylethyl acrylate , 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethyl methyl acrylate, 2-perfluoromethyl acrylate 2-perfluoroethyl methyl, 2-perfluoro mouth Fluorinated alkyl acrylates such as hexylethyl, 2-perfluorodecylethyl acrylate, and 2-perfluorohexadecyl acrylate;
  • Etc may be used alone or in combination of two or more.
  • n-butyl acrylate is preferable from the viewpoint of low-temperature characteristics, compression set, cost, and availability.
  • Ethyl acrylate is preferred when oil resistance and mechanical properties are required.
  • 2-Ethylhexyl acrylate is preferred when low temperature properties, mechanical properties and compression set are required.
  • acrylic acid 2-Metokishechi Le 10-90 wt 0/0, acrylate n- butyl 10-90 wt 0/0 A mixture of 0 to 80% by weight of ethyl acrylate is preferred, and 15 to 85% by weight of 2-methoxyethyl acrylate, 15 to 85% by weight of n-butyl acrylate, and 0 to 70% by weight of ethyl acrylate. I like it.
  • Examples of the functional group serving as a precursor of the unit (c) include t-butyl acrylate, isopropyl acrylate, ⁇ , a-dimethylbenzyl acrylate, ⁇ -methylbenzyl acrylate, and t-butyl methacrylate. , Isopropyl methacrylate, ⁇ , ⁇ -dimethylbenzyl methacrylate, ⁇ -methylbenzyl methacrylate, and the like, but are not limited thereto.
  • the method for introducing the unit (c) into the acrylic block copolymer ( ⁇ ) is described later. Describe.
  • examples of the bulle monomer that can be copolymerized with the acrylate ester constituting the acryl polymer block (a) include methacrylic acid esters, aromatic alkenyl compounds, vinyl cyanide compounds, Examples include conjugation compounds, halogen-containing unsaturated compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, and maleimide compounds.
  • methacrylic acid ester examples include:
  • Methacrylic acid alicyclic hydrocarbon esters such as cyclohexyl methacrylate and isoborn methacrylate
  • Methacrylic acid aralkyl esters such as benzyl methacrylate
  • Methacrylic acid aromatic hydrocarbon esters such as methacrylic acid phenol and methacrylic acid toluene
  • esters of methacrylic acid such as 2-methoxyethyl methacrylate and 3-methoxybutyl methacrylate and functional group-containing alcohols having etheric oxygen;
  • aromatic alkenyl compound examples include styrene, ⁇ -methylstyrene, ⁇ -methylstyrene, and ⁇ -methoxystyrene.
  • Examples of the cyanobi-loui compound include acrylonitrile, meta-tallow-tolyl and the like.
  • conjugation compound examples include butadiene and isoprene.
  • halogen-containing unsaturated compound examples include salt vinyl, salt vinylidene, perfluoroethylene, perfluoropropylene, and vinylidene fluoride.
  • Examples of the unsaturated dicarboxylic acid compound include maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid, fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid, and the like.
  • burester compound examples include butyl acetate, butyl propionate, butyl benzoate, vinyl benzoate and cinnamate bur.
  • maleimide compounds include maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenolmaleimide, cyclohexylmaleimide and the like. Can be mentioned.
  • These vinyl monomers may be used alone or in combination of two or more.
  • the bulle monomer is required for the glass transition temperature, elastic modulus and polarity required for the acrylic polymer block (a), and when the acrylic block copolymer (A) is used as a composition.
  • acrylonitrile can be copolymerized for the purpose of improving oil resistance.
  • the glass transition temperature (Tg) of the acrylic polymer block (a) is preferably 50 ° C or lower.
  • Acrylic polymer block (a) glass The transition temperature (Tg) is set according to the homopolymer gala of each monomer constituting the polymer block.
  • the transition temperature Using the values described in the 3rd edition of the above-mentioned Polymer Handbook as the transition temperature, from the polymerization ratio of each monomer, the force expressed in the Fox formula, and the weight ratio of the monomers constituting the polymer block are calculated. It can be done by adjusting.
  • the methacrylic polymer block (b) is a methacrylic polymer from the viewpoint that it is easy to obtain an acrylic block copolymer (A) having the desired physical properties, cost and availability.
  • 50 to 100 weight units containing methacrylic acid ester in the entire block (b). / 0 preferably 50 to 85% by weight, and containing 10 to 99.5% by weight, preferably 20 to 99.5% by weight of a monomer having a functional group as a precursor of the unit (c).
  • the molecular weight of the methacrylic polymer block (b) may be determined based on the cohesive force required and the time required for the polymerization.
  • the cohesive force is said to depend on the interaction between molecules (in other words, polarity) and the degree of entanglement, and as the number average molecular weight increases, the entanglement point increases and the cohesive force increases. That is, the molecular weight between the entanglement points of the polymer constituting the methacrylic polymer block (b) is Mc, and the methacrylic polymer pro
  • the range of number average molecular weight (M) of the rubber (b) is preferred when cohesion is required.
  • M 2 X Mc.
  • a certain level of cohesion and creep properties were achieved.
  • Mc ⁇ M ⁇ 2 X Mc is preferred.
  • the molecular weight between the entanglement points is Wu
  • the number average molecular weight (M) is As the polymerization time increases, the polymerization time tends to be longer, so it may be set according to the required productivity, but is preferably 200,000 or less, more preferably 100,000 or less.
  • the methacrylic acid ester constituting the methacrylic polymer block (b) is exemplified as a vinyl monomer copolymerizable with the acrylate ester constituting the acrylic polymer block ( a ). The thing which was done is mentioned. These methacrylic acid esters may be used alone or in combination of two or more. Of these, methyl methacrylate is preferred from the viewpoint of cost and availability.
  • Examples of the monomer having a functional group serving as a precursor of the unit (c) include monomers similar to the constituent monomers exemplified in the description of the acrylic polymer block (a). .
  • Examples of the bull monomers that can be copolymerized with the methacrylic acid ester that constitute the methacrylic polymer block (b) include acrylic acid esters, aromatic alkenyl compounds, vinyl cyanide compounds, conjugated genes. Compounds, halogen-containing unsaturated compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, maleimide compounds, and the like. The copolymerizable vinyl monomer is used in at least one of the above constituent monomers.
  • acrylic ester examples include monomers similar to the constituent monomers exemplified in the description of the acrylic polymer block (a).
  • Examples of the aromatic alk-louie compound, vinyl cyanide compound, conjugated-gen compound, halogen-containing unsaturated compound, unsaturated dicarboxylic acid compound, vinyl ester compound, and maleimide compound include the acrylic-based compound. Examples thereof include the same monomers as the constituent monomers exemplified as the vinyl monomer that can be copolymerized in the description of the polymer block (a).
  • the methyl methacrylate polymer has the ability to depolymerize almost quantitatively by thermal decomposition.
  • the methacrylic polymer block (b) is composed of a methyl methacrylate polymer.
  • acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-methoxyethyl acrylate or mixtures thereof, or styrene.
  • acrylonitrile can be copolymerized with the methacrylic polymer block (b) for the purpose of improving oil resistance.
  • the glass transition temperature (Tg) of the methacrylic polymer block (b) is preferably 100 ° C or higher. More preferably, the temperature is 110 ° C or higher. High temperature when glass transition temperature (Tg) is less than 100 ° C
  • the rubber elasticity at may be lower than the desired value.
  • the glass transition temperature (Tg) of the methacrylic polymer block (b) is set by the homopolymer of each monomer constituting the polymer block.
  • the weight ratio of the monomer constituting the polymer block is adjusted from the polymerization ratio of each monomer according to the above Fox formula. Can be performed.
  • the reactive functional group (unit (c)) in the acrylic polymer block (a) and the Z or methacrylic polymer block (b) is a compound having an amino group, a hydroxyl group, an epoxy group, or the like. Therefore, the acrylic block copolymer (A) can be used as a crosslinking site with the compatibilizing agent (C) when blended with the thermoplastic elastomer (B). In addition, since the unit (c) has a high glass transition temperature (Tg), when introduced into the methacrylic polymer block (b), which is a hard segment, the heat resistance of the acrylic block copolymer (A) is improved. .
  • Tg glass transition temperature
  • the glass transition temperature of the polymer containing the unit (c) is, for example, in the case of polymethacrylic anhydride, by introducing a unit (c) that is as high as 159 ° C., the acrylic block copolymer ( U) is preferred because it improves the heat resistance of A).
  • Unit (c) is the general formula (1):
  • R 1 is a hydrogen atom or a methyl group, which may be the same or different from each other, p is an integer of 0 or 1, q is an integer of 0 to 3), and contains an acid anhydride group represented by Unit (cl) and unit (c2) containing Z or carboxyl group.
  • Q in the general formula (1) is an integer of 0 to 3, preferably 0 or 1, and more preferably 1. If q exceeds 3, polymerization may become complicated, and cyclization to an acid anhydride group may be difficult.
  • p is an integer of 0 or 1. When q is 0, p is also 0. When q is 1 to 3, p is preferably 1.
  • the unit (c) is contained in the acrylic polymer block (a) and the Z or methacrylic polymer block (b).
  • the introduction site of the unit (c) is required for the reaction point of the acrylic block copolymer (A), the cohesive force and glass transition temperature of the block constituting the acrylic block copolymer (A), and further.
  • the physical properties of the acrylic block copolymer (A) to be selected it is appropriately selected.
  • the unit (c) may be introduced into the acrylic polymer block ( a ) as a crosslinkable reaction site (crosslinking point). From the viewpoints of reaction point control, heat resistance, rubber elasticity, etc., it is preferable to have the unit (c) in either one of the acrylic polymer block (a) or the methacrylic polymer block (b). ,.
  • R 1 in the general formula (1) is contained in the acrylic polymer block (a) in which both methyl groups are preferred.
  • R 1 in formula (1) is preferably a hydrogen atom.
  • R 1 is a hydrogen atom
  • R 1 is a methyl group
  • the preferred range of the content of the unit (c) is the cohesive strength of the unit (c), the reactivity with the compatibilizer (C), the structure and composition of the acrylic block copolymer (A), the acrylic type It varies depending on the number of blocks constituting the block copolymer (A), the glass transition temperature, and the site and manner in which the acid anhydride group-containing unit (cl) and force lpoxyl group-containing unit (c2) are contained.
  • a preferable range of the content of the unit (c) is 0.1 to 99.9% by weight in the entire acrylic block copolymer (A), and 0.1 to 80% by weight is more preferable. 1-50% by weight is more preferred Yes.
  • the compatibility between the acrylic block copolymer (A) and the compatibilizer (C) may be insufficient.
  • the heat resistance of the methacrylic polymer block (b) when a unit (c) having a high Tg is introduced into the methacrylic polymer block (b), which is a node segment, 0. If it is less than 1% by weight, the heat resistance may not be sufficiently improved, and the development of rubber elasticity at high temperatures may be reduced. On the other hand, if it exceeds 99.9% by weight, the cohesive force becomes too strong, and the productivity may be lowered.
  • the acrylic block copolymer (A) contains a unit (c2) containing a carboxyl group, the heat resistance and cohesive strength are improved.
  • the carboxyl group-containing unit (c2) has a strong cohesive force, and a polymer of a monomer containing a carboxyl group has a high glass transition temperature (Tg) .
  • Tg glass transition temperature
  • the glass transition temperature (Tg) of polymethacrylic acid is Improves heat resistance of block copolymer (A), which is as high as 228 ° C.
  • Functional groups such as hydroxyl groups also have hydrogen-bonding ability, but the effect of improving heat resistance is low compared to the unit (c2) containing a strong lpoxyl group, which is low. Therefore, if the unit containing a carboxyl group (c2) is contained, the heat resistance and cohesive strength of the talyl block copolymer (A) can be further improved, which is preferable.
  • the content of the carboxyl group-containing unit (c2) is preferably 1 or 2 or more per polymer block.
  • the mode in which the units (c2) are polymerized may be random copolymerization or block copolymerization.
  • the content of the carboxyl group-containing unit (c2) is preferred! /, The range is the cohesive strength of the unit (c2), the structure and composition of the block copolymer, and the blocks constituting the block copolymer As well as the site and mode of the unit (c2).
  • the content of the unit (c2) having a carboxyl group is preferably 0.1 to 50% by weight, more preferably 0.5 to 50% by weight in the whole acrylic block copolymer (A). More preferred is ⁇ 40% by weight. Since the carboxyl group-containing unit (c2) tends to cyclize with adjacent ester units at high temperatures, the content of the acrylic block copolymer (A) unit (c2) is 50% by weight.
  • the carboxyl group-containing unit (c2) is polymerized. It is preferable to produce 0.1% by weight or more in the body block (b). The amount produced is 0.1 wt.
  • the heat resistance and cohesive strength may be insufficiently improved.
  • the method for producing the acrylic block copolymer (A) is not particularly limited! However, controlled polymerization is preferred. Controlled polymerization includes living-on polymerization, radical polymerization using a chain transfer agent, and recently developed living radical polymerization. Living radical polymerization is preferred from the viewpoints of the molecular weight and structure control of the block copolymer and the ability to copolymerize monomers having a crosslinkable functional group. Further, force atom transfer radical polymerization such as ease of control is preferred.
  • Atom transfer radical polymerization is a metal complex having an organic halide or a halogenated sulfone compound as an initiator and a Group 8, 9, 10, or 11 element as a central metal in the periodic table.
  • a metal complex having an organic halide or a halogenated sulfone compound as an initiator and a Group 8, 9, 10, or 11 element as a central metal in the periodic table.
  • termination reaction such as coupling between radicals having a very high polymerization rate is likely to occur! /
  • a monofunctional, difunctional, or polyfunctional compound can be used as the organic halide or sulfonyl halide compound used as an initiator. These can be used properly according to the purpose.
  • a diblock copolymer a monofunctional compound is preferred.
  • a bifunctional compound is preferred. Multifunctional compounds are preferred when producing branched block copolymers.
  • Examples of the monofunctional compound include compounds represented by the following chemical formulas.
  • CH represents a phenylene group.
  • the phenylene group is an ortho-substituted, meta-substituted group.
  • R 1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms.
  • X represents chlorine, bromine or iodine.
  • R 2 represents a monovalent organic group having 1 to 20 carbon atoms.
  • Examples of the bifunctional compound include compounds represented by the following chemical formulas.
  • R 3 represents an alkyl group having 1 to 20 carbon atoms, a 6 to 20 aryl group, or a 7 to 20 aralkyl group.
  • CH represents a phenylene group.
  • C H represents a phenol group
  • n an integer of 0 to 20.
  • X represents chlorine, bromine or iodine.
  • Examples of the multifunctional compound include compounds represented by the following chemical formulas.
  • CH represents a tri-substituted full group.
  • the tri-substituted full group represents a substituent.
  • the position of 1 may be any of 1st to 6th positions.
  • X represents chlorine, bromine or iodine.
  • These organic halides or halogenated sulfole compounds that can be used as initiators have carbon bonded to a halogen group, a phenol group, etc. The halogen bond is activated and polymerization starts.
  • the amount of the initiator used may be determined in accordance with the molecular weight of the required block copolymer and the specific power with the monomer. That is, the molecular weight of the block copolymer can be controlled by the number of monomers used per molecule of the initiator.
  • the transition metal complex used as the catalyst for the atom transfer radical polymerization is not particularly limited, but preferred are monovalent and zerovalent copper complexes, divalent ruthenium complexes, and divalent iron. And divalent nickel complexes. Among these, a copper complex is preferable from the viewpoint of cost and reaction control.
  • monovalent copper compounds include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, cuprous oxide, cuprous perchlorate, and the like. be able to.
  • aluminum alkoxides When used as a catalyst, aluminum alkoxides can also be added as an activator. Furthermore, divalent iron bistriphenylphosphine complex (FeCl (PPh)), divalent-
  • Bistributylphosphine complex (NiBr (PBu)) can also be used as a catalyst. Touch to use
  • the amounts of the medium, the ligand and the activator are not particularly limited, but can be appropriately determined from the relationship between the amount of the initiator, the monomer and the solvent used and the required reaction rate.
  • the atom transfer radical polymerization can be carried out without solvent (bulk polymerization) or in various solvents.
  • solvent for example,
  • Hydrocarbon solvents such as benzene and toluene
  • Halogenated hydrocarbon solvents such as methylene chloride and black mouth form
  • Ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; alcohol solvents such as methanol, ethanol, propanol, isopropanol, n-butanol, and t-butanol;
  • -Tolyl-based solvents such as acetonitrile, propio-tolyl, benzo-tolyl;
  • Ester solvents such as ethyl acetate and butyl acetate
  • carbonate solvents such as ethylene carbonate and propylene carbonate. These solvents can be used in a mixture of two or more. When a solvent is used, the amount used can be appropriately determined from the relationship between the viscosity of the entire reaction system and the required reaction rate (ie, stirring efficiency).
  • the atom transfer radical polymerization is preferably performed at room temperature to 200 ° C, more preferably 50 to
  • the atom transfer radical polymerization temperature is lower than room temperature, When the temperature exceeds 200 ° C, an inexpensive polymerization solvent may not be used.
  • a method for producing the acrylic block copolymer (A) by the atom transfer radical polymerization a method of sequentially adding monomers, a polymer synthesized in advance as a polymer initiator, and the next block And a method of polymerizing separately polymerized polymers by reaction. These methods can be used properly according to the purpose. From the viewpoint of simplicity of the production process, a method by sequential addition of monomers is preferred.
  • the method for introducing the unit (cl) containing an acid anhydride group is not particularly limited, but a unit containing a group that is a precursor of an acid anhydride group is introduced into the block copolymer, and It is preferable to cyclize afterwards. Details of the method will be described below.
  • R 2 represents a hydrogen atom or a methyl group
  • R 3 represents a hydrogen atom, a methyl group or a full group, and may be the same or different from each other except that it contains at least one methyl group.
  • the block copolymer (A) using the monomer exemplified below as a block copolymer having at least one unit represented by the following formula, that is, the acrylic ester constituting the acrylic polymer block ( a ):
  • the composition containing the copolymer block (A) is preferably 18 It can be introduced by melt-kneading and cyclization at a temperature of 0 to 300 ° C. Kneading temperature Force S When the temperature is lower than 180 ° C, the acid anhydride group may be insufficiently formed. When the temperature is higher than 300 ° C, the acrylic block copolymer (A) itself decomposes. Sometimes.
  • the unit represented by the general formula (2) is eliminated and cyclized with an adjacent ester unit at a high temperature to generate, for example, a 6-membered cyclic acid anhydride group (for example, Hatada et al., (See JAM PURE APPL. CHEM., A30 (9 & 10), PP. 645-667 (1993)).
  • a polymer having ⁇ hydrogen in which the ester unit is bulky the ester unit decomposes at a high temperature to generate a carboxyl group, followed by cyclization, for example, an acid anhydride group such as a 6-membered ring. Generate.
  • an acid anhydride group can be easily introduced into the acrylic block copolymer ( ⁇ ).
  • the monomer constituting the unit represented by the general formula (2) include t-butyl acrylate, isopropyl acrylate, a-dimethyl benzyl acrylate, ⁇ -methylbenzyl acrylate, and t-butyl methacrylate. , Isopropyl methacrylate, ⁇ -dimethylbenzyl methacrylate, ⁇ -methylbenzyl methacrylate, and the like, but are not limited thereto. Of these, t-butyl acrylate and t-butyl methacrylate are preferred from the viewpoints of availability, ease of polymerization, and ease of formation of acid anhydride groups.
  • the carboxyl group-containing unit (c2) contains an acid anhydride group to the acrylic block copolymer.
  • the unit containing a carboxyl group (c2) Preferably, it is generated. This is a force that allows easy control of the reaction point of the acrylic block copolymer (A) and introduction of the carboxyl group-containing unit (c2) into the acrylic block copolymer (A).
  • the unit (c2) containing a carboxyl group is preferably contained in the same block as the block containing a unit (cl) containing an acid anhydride group. Further, from the viewpoint of heat resistance and cohesive strength, it is more preferable to contain it in the methacrylic polymer block (b). It is a methacrylic polymer block (b This is because, by introducing the glass transition temperature (Tg) and the unit (c2) having a high cohesive force and a carboxyl group into the resin, it becomes possible to exhibit more rubber elasticity at a high temperature. On the other hand, when the acrylic polymer block (a) contains the carboxyl group-containing unit (c2), the compatibility point with the compatibilizer (C) is also preferable.
  • the olefin-based thermoplastic elastomer (B) is not particularly limited, but the polyolefins made of thermoplastic polyolefin homopolymer or copolymer, and a completely cross-linked force. -It is preferable that it has a combination force with trill 'butadiene rubber (NBR).
  • NBR trill 'butadiene rubber
  • the polyolefins are thermoplastic and include crystalline polyolefin homopolymers and copolymers. Among them, a copolymer containing ethylene in polypropylene is more preferable in order to improve the low-temperature characteristics preferred by those having polypropylene as a main component.
  • Examples of the olefinic rubber include those obtained by dynamically cross-linking EPDM rubber in olefinic resin, which is preferably ethylene propylene rubber having excellent low-temperature characteristics and EPDM rubber which is a terpolymer of non-conjugated gen. Particularly preferred.
  • EPDM rubber By dynamically cross-linking the EPDM rubber in the polyolefin resin, the EPDM rubber can be uniformly dispersed in a small amount of the polyolefin resin. Excellent rubber properties can be expressed.
  • the olefin-based thermoplastic elastomer (B) preferably has a Shore A hardness of 50 to 90, particularly 65 to 85 at 23 ° C.
  • Such olefin-based thermoplastic elastomers are commercially available under trade names such as Santoprene and GEOLAST (both manufactured by Advanced Elastomers), and are easily available.
  • the compatibilizing agent (C) in the thermoplastic elastomer composition is not particularly limited.
  • the acrylic block copolymer (A) and the olefin thermoplastic elastomer (B) are more preferably used.
  • an olefin thermoplastic resin (modified polyolefin) containing an epoxy group that reacts with the unit (c) such as polymethacrylic anhydride of the acrylic block copolymer (A) is preferable.
  • Examples thereof include polypropylene grafted with relate and glycidyl metaatarylate.
  • the content of glycidyl metatalylate in these modified polyolefin resins is preferably 0.05% to 50% by weight, more preferably 0.1% to 20% by weight. If the glycidyl methacrylate content is less than 0.05% by weight, the compatibility between the acrylic block copolymer (A) and the olefin thermoplastic elastomer (B) is insufficient, and the tensile strength is increased. There is something wrong.
  • modified polyolefin resins are, for example, commercially available product names such as Bond First (manufactured by Sumitomo Chemical Co., Ltd.), Modiper (manufactured by Nippon Oil & Fats Co., Ltd.), and can be easily obtained from the market. .
  • the thermoplastic elastomer composition used in the present invention includes (A) an acrylic block copolymer and (B) an olefin-based thermoplastic elastomer, and further (A) and (B).
  • (C) those containing a compatibilizer are suitable.
  • the acrylic block copolymer (A) the olefin-based thermoplastic elastomer (B) is 50 to 600 parts by weight, more preferably 200 to 600 parts by weight, still more preferably 400 parts by weight
  • C Compatibilizers consisting of 5 to 50 parts by weight are preferred.
  • Content power of each of the above (A) to (C) By being within the above range, a molded article having excellent heat resistance and oil resistance and good dimensionality by injection molding can be obtained. It is particularly preferable when manufacturing boots for manufacturing.
  • thermoplastic elastomer composition was prepared by measuring the acrylic block copolymer (A), the olefin thermoplastic elastomer (B), and the compatibilizer (C) during molding. Although it may be put into a machine, it is preferable to pelletize before molding molding from the viewpoint of handling and uniformity of kneading.
  • the method of pelletizing the thermoplastic elastomer composition is not particularly limited, and is heated at an appropriate temperature using a known apparatus such as a Banbury mixer, roll mill, kneader, single-screw or multi-screw extruder. However, it can be shaped into pellets by mechanically kneading.
  • the temperature at the time of kneading may be adjusted according to the melting temperature of the acrylic block copolymer (A), the olefin-based thermoplastic elastomer (B), the compatible solvent (C) used, for example. 180-300 ° C.
  • thermoplastic elastomer resin In the case of a molded product requiring low-temperature characteristics, as thermoplastic elastomer resin, it is preferable to use a composition that also has an acrylic block copolymer (A) and a polyorganosiloxane graft polymer (D). In the case where higher modulus of elasticity is required, a composition comprising an talyl block copolymer (A), a polyorganosiloxane graft polymer (D), a thermoplastic resin, a lubricant, and an inorganic filler. Is preferred to use ⁇ .
  • the composition of the polyorganosiloxane-based graft polymer (D) is not particularly limited, but the monomer (d2) is added in the presence of 40 to 95% by weight of the polyorganosiloxane (dl).
  • a copolymer obtained by polymerizing ⁇ 10% by weight and further polymerizing 5 to 60% by weight of vinyl monomer (d3) [100% by weight in total of (dl), (d2) and (d3)] is preferable.
  • the monomer (d2) is a polyfunctional monomer (X) having two or more polymerizable unsaturated bonds in the molecule 50 to: LOO wt%, and other copolymerizable bur system Monomer (y) A monomer composed of 0 to 50% by weight. Furthermore, the content of the graft component including the monomer (d2) and the bull monomer (d3) is 5 to 40% by weight, and the polyorganosiloxane content is 95 to 60% by weight. I like it.
  • thermoplastic elastomer resin comprising the acrylic block copolymer (A) and the polyorganosiloxane graft polymer (D) has a lubricant, an inorganic filler, and an Thermoplastic rosin can be blended.
  • the blending amount of each component is 10 parts by weight of the polyorganosiloxane graft polymer (D) with respect to 100 parts by weight of the talyl block copolymer (A): LOO parts by weight, 0.1 to 10 parts by weight of the lubricant, Inorganic fillers 0.1 to L00 parts by weight, thermoplastic resin 0.1 to L00 parts by weight are preferable ranges.
  • Examples of the lubricant include fatty acids such as stearic acid and palmitic acid, fatty acid metal salts such as calcium stearate, zinc stearate, magnesium stearate, potassium palmitate and sodium normitate, polyethylene wax, and polypropylene wax.
  • fatty acids such as stearic acid and palmitic acid
  • fatty acid metal salts such as calcium stearate, zinc stearate, magnesium stearate, potassium palmitate and sodium normitate
  • polyethylene wax such as polyethylene wax, and polypropylene wax.
  • Waxes such as waxes, montanic acid waxes, low molecular weight polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene, polyorganosiloxanes such as dimethylpolysiloxane, octadecylamine, alkyl phosphates, fatty acid esters, ethylene
  • Examples include, but are not limited to, amide-based lubricants such as bis-stear mouth amide, fluorine resin powders such as 4-fluorinated styrene resin, molybdenum disulfide powder, silicone resin powder, silicone rubber powder, and silica. Ru Not to. These can be used alone or in combination of two or more You may use it.
  • stearic acid, zinc stearate, calcium stearate, magnesium stearate, and stearamide are preferred from the viewpoint of low friction and excellent workability on the surface of the resin.
  • Examples of the inorganic filler include titanium oxide, zinc sulfide, zinc oxide, carbon black, calcium carbonate, calcium silicate, clay, kaolin, silica, mica powder, alumina, glass fiber, metal fiber, and titanium. Forces including, but not limited to, acid-powered whisker, asbestos, wollastonite, my strength, talc, glass flakes, milled fiber, metal powder, and the like. These may be used alone or in combination of one or more. Of these, silica is preferred from the viewpoint of high elastic modulus, and weather resistance and carbon black and titanium oxide are preferred from the viewpoint that they can be used as pigments.
  • thermoplastic resin examples include polysalt resin resin, polyethylene resin, polypropylene resin, cyclic olefin copolymer resin, polymethylmetatalate resin, polystyrene resin Resin, polyphenylene ether resin, polycarbonate resin, polyester resin, polyamide resin, polyacetal resin, polyphenylene sulfide resin, polysulfone resin, polyimide resin, polyetherimide resin, poly Examples include ether ketone resins, polyether ether ketone resins, polyamide imide resins and imido polymethyl methacrylate resins. These may be used alone or in combination of two or more.
  • those having good compatibility with the acrylic block copolymer (A) are preferably used, and those having a functional group capable of reacting with an acid anhydride group are more preferably used.
  • the functional group capable of reacting with the acid anhydride group include an amino group and a hydroxyl group.
  • the thermoplastic resin having these include polyester-based resins and polyamide-based resins.
  • a thermoplastic resin containing a functional group that reacts with an acid anhydride group can also be suitably used.
  • thermoplastic elastomer resin used in the present invention has a stabilizer (an anti-aging agent, a light stabilizer, an ultraviolet absorber, etc.), a flexibility imparting agent, and a flame retardant according to necessary characteristics. Further, a release agent, an antistatic agent, an antibacterial antifungal agent and the like may be added. These additives may be appropriately selected and used according to the required physical properties, cache properties and the like.
  • Examples of the stabilizer include the following compounds: However, it is not limited to these.
  • Anti-aging agents include: phenol a naphthylamine (PAN), octyl diphenylamine, N, N '— diphenol-p p-dirangeamine (DPPD), N, N' — G ⁇ -naphthyl ⁇ Phenylenediamine (DNPD), N— (1,3 dimethyl-butyl) —N′-Phenenoleine p Phenylenediamine, N Phenolene N′—Isopropynole p-Phenylenediamine (IPPN), N , N '— Dianoleno p-phenylene diamine, phenothiazine derivative, diaryl-p phenylenediamine mixture, alkylated phenylenediamine, 4, 4' — a, a-dimethylbenzyldiphenylamine, p, p toluenesulfo -Luaminodiphenylamine,
  • Examples of light stabilizers and UV absorbers include 4-t-butylphenol salicylate, 2,4-dihydroxybenzophenone, 2,2 'dihydroxy-4-methoxybenzophenone, and ethyl 2- Cyan 3, 3 '— diphenyl attalylate, 2 ethylhexyl 2 di cyano 1, 3' — diphenyl acrylate, 2 hydroxy 1 5 chlorbenzophenone, 2 hydroxy 4-methoxybenzophenone 2 Hydroxy-4-octoxybenzophenone, monoglycol salicylate, oxalic acid amide, 2, 2 ', 4, 4'-tetrahydroxybenzophenone. These stabilizers may be used alone or in combination of two or more.
  • Examples of the flexibility-imparting agent include plasticizers, softeners, oligomers, oils (animal oil, vegetable oil, etc.), petroleum fractions (kerosene, light oil, heavy oil, Naphtha, etc.) with acrylic block copolymer (A), olefin thermoplastic elastomer (B), compatibilizer (C), polyorganosiloxane graft polymer (D) Those having excellent affinity are preferably used.
  • low-volatile plasticizers with low heat loss are adipic acid derivatives, phthalic acid derivatives, dartaric acid derivatives, trimellitic acid derivatives, pyromellitic acid derivatives, polyester-based plasticizers, glycerin derivatives, epoxy-derived polyester-based polymerizations.
  • a mold plasticizer, a polyether polymerization type plasticizer, and the like are preferably used.
  • softener examples include paraffinic oil, naphthenic process oil, and aromatic series.
  • plasticizer examples include dimethyl phthalate, jetyl phthalate, di-n-butyl phthalate, di- (2-ethylhexyl) phthalate, diheptyl phthalate, diisodecyl phthalate, di-n-phthalate.
  • —Phthalic acid derivatives such as octyl, diisonoyl phthalate, ditridecyl phthalate, octyl decyl phthalate, butylbenzyl phthalate, dicyclohexyl phthalate; isophthalic acid derivatives such as dimethyl isophthalate; ) Tetrahydrophthalic acid derivatives such as tetrahydrophthalic acid; dimethyl adipate, dibutyl adipate, di-n-xyl adipate, di-ethyl adipate (2-ethylhexyl), dioctyl adipate, isonoid adipate, diisodecyl adipate, Adipates such as dibutyl diglycol adipate Acid derivatives; azelaic acid derivatives such as diazeylate di-2-ethylhexyl; sebacic acid derivatives such as dibutyl sebac
  • plasticizers such as those widely marketed as rubber or thermoplastic resin plasticizers can be used.
  • Commercially available plasticizers include Thiokol TP (Morton), Ade force sizer O-130P, C-79, UL-100, P-200, RS-735 (Asahi Denshi Kogyo Co., Ltd.) ), Sansosaizer N-400 (manufactured by Shin Nippon Rika Co., Ltd.), BM—4 (manufactured by Daihachi Chemical Industry Co., Ltd.), EHPB (manufactured by Ueno Pharmaceutical Co., Ltd.), UP—1000 (Toagosei Chemical Co., Ltd.) )).
  • oils such as castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, pine oil, tall oil, sesame oil, camellia oil, and the like.
  • Examples of other flexibility-imparting agents include polybutene-based oils, spinned oils, machine oils, tricresyl phosphate, and the like.
  • Examples of the flame retardant include, but are not limited to, triphenyl phosphate, tricresyl phosphate, deca mouth mobile biphenyl, decabromobiphenyl ether, and antimony trioxide. These flame retardants may be used alone or in combination of two or more.
  • the resin boots of the present invention are manufactured by injection molding the thermoplastic elastomer resin as described above.
  • the conditions for injection molding of the resin-made boot from the elastomer resin are, for example, cylinder temperature: 150 to 230 ° C, nozzle temperature: 180 to 240 ° C, injection speed: low speed, cooling time: 30 seconds, Mold temperature: 30-80 ° C.
  • the resin-made boots manufactured by the injection molding method of the present invention have excellent low-temperature characteristics, oil resistance, heat resistance, weather resistance, mechanical characteristics, fatigue strength, etc., and are used for constant velocity joints for automobiles. It can be suitably used for boots and the like.
  • the resin-made boots of the present invention have a simplified molding process and excellent recyclability as compared with conventional vulcanized rubber systems.
  • BA, MEA, MMA, and TBMA are n-butyl acrylate, 2-methoxyethyl acrylate, and methacrylate, respectively.
  • the molecular weight of the acrylic block copolymer was determined using a GPC analyzer (system: GPC system manufactured by Waters, column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK). Was used as the mobile phase, and the molecular weight in terms of polystyrene was determined.
  • GPC analyzer system: GPC system manufactured by Waters, column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK).
  • the block body of carboxylic acid ester structure was analyzed together with the block body of 6-membered cyclic acid anhydride type structure and heavy chloroform as a measuring solvent.
  • TEX30HSS-25.5PW-2V manufactured by Nippon Steel
  • An injection mold comprising a cavity mold 10 and a core mold 20 having the structure shown in FIGS. 1 to 4, the height of which is 105 mm, and the bellows portion 4 has an inner diameter shown in Table 1 as shown in FIG.
  • the molds capable of molding the thick resin boot 1 were mounted on an injection molding machine “J150E-P” (manufactured by Nippon Steel Works) with a clamping pressure of 150 TON.
  • the injection mold is almost the same except that the gate for injecting the thermoplastic elastomer into the molding space 30 is not a dome-shaped gate but a planar gate as shown in Fig. 16 (a).
  • a boot made of greaves was produced in the same manner as in Example 1.
  • Example 1 the mold release from the core mold is very good after molding, and the productivity is good. Also, it has a good appearance without causing uneven flow of the resin during molding, and the compressed air As a result, it was possible to manufacture hollow molded products (waxed boots) that have small dimensional accuracy, excellent dimensional stability, and recyclable strength. On the other hand, in Comparative Example 1, the air that was press-fitted into the molded product P was not uniformly distributed between the core mold 102 and the molded product P, and a demolding failure occurred.
  • Injection mold consisting of a cavity mold 10 and a core mold 20 having the structure shown in FIGS.
  • a mold capable of forming a resin boot 1A having a height of 105 mm and an accordion portion 4 having an inner diameter and a wall thickness shown in Table 2 at a clamping pressure of 150 TON is used.
  • Each was mounted on an injection molding machine “J150E-P” (manufactured by Nippon Steel Works).
  • the pellets of the thermoplastic elastomer composition obtained in Production Example 2 were injection molded at a cylinder temperature of 180 ° C, a nozzle temperature of 230 ° C, an injection speed of 10%, a cooling time of 30 seconds, and a mold temperature of 40 ° C.
  • the mold mold 20 is removed from the core mold 20 with an air pressure of 5 kgZcm 2 (0.449 MPa) emitted from the outlet 21 of the core mold 20, and the gate part of the molded product (part of line L in Fig. 9). ) To obtain a constant velocity joint boot 1A.
  • the pellets of the thermoplastic elastomer composition obtained in Production Example 2 were molded using the injection molding machine “J150E-P” (manufactured by Nippon Steel Works) with a mold clamping pressure of 150 TON. Is used for injection molding under the conditions of a cylinder temperature of 150 to 230 ° C, a nozzle temperature of 230 ° C, an injection speed of 10%, a cooling time of 30 seconds, and a mold temperature of 40 ° C. Demold from the core mold 20 with an air pressure of 5kgZcm 2 (0.449MPa) from the air outlet 21 of the mold 20. The resulting molded part is the part c that becomes the lid molded into the gate part and the runner part, etc. (The portion of line L in FIG. 9 also corresponds to the previous portion) was cut out to obtain a resin boot 1B having the shape and dimensions shown in FIGS. 12 and 13 and Table 2.
  • a resinous resin boot was obtained in the same manner as in Example 3 except that the curvature radius R of the valley 5c was 1.5 mm.
  • the maximum expansion amount (deformation amount: mm) was measured at a rotational speed of the drive shaft of 2000 rpm, a shaft angle of 10 °, and a temperature of 80 ° C. The smaller the deformation, the better. When the deformation is large, the boot hits the surrounding members due to the centrifugal force during rotation, and the bellows part is easily cut.
  • the durability of the drive shaft was measured at a rotational speed of 100 i: pm, a joint angle of 40 °, and a temperature of room temperature. Durability was determined by the time taken to crack the bellows. The longer the time it takes for the bellows to crack, the better the fatigue.
  • the constant velocity joint boot 1A of Example 2 having the first resinous boot shape is excellent in flexibility and durability as a whole. From this result, the bellows By forming at least some of the valleys thicker, expansion due to centrifugal force during rotation is prevented, and conversely, by reducing the wall thickness of the peaks, the flexibility of the bellows is impaired. In addition, the thickness of each valley is the same as or thicker than that of the adjacent peak near the gate side mounting part, so that the continuity of the resin is maintained. It is possible to produce a grease boot with excellent appearance and durability that allows the grease to flow and fill smoothly from the peak to the valley, without generating weld lines.
  • the constant velocity joint boots of Example 3 and Example 4 having the second greave boot shape have a bellows part shape that is larger than the boot of Example 2 having the first greave boot shape. Despite its thin wall thickness, it has excellent flexibility and deformability. From this result, the inner diameter d of the valley 5c and the outer diameter of the crest 6c closest to the large-diameter mounting part in the bellows part 4 are reduced.
  • the present invention is flexible and excellent in flexibility and durability even when the bellows portion is thin, and can be used as a boot for a constant velocity joint even under severe conditions.
  • Recyclable rosin boots can be provided as an alternative.

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Abstract

A method of injection molding for producing a cylindrical hollow molded article open at each end. A mold comprising a cavity mold (10) and a core mold (20) to be disposed therein is provided with a domed gate (40) so that the gate projects from one open end of the hollow molded article, which is to be molded in a molding space (30) of the mold, outward in the axial direction for the molded article. A molten thermoplastic resin is injected through one point of the top part of the domed gate (40) into the molding space (30) toward the axial direction of the hollow molded article to be molded in the molding space. The molding space is thus filled with the molten resin to mold a hollow molded article which is close at one end. Thereafter, the mold is opened and high-pressure air is blown into the hollow molded article to take it out of the core mold (20). That close-end part of the molded article taken out which begins with the gate part is cut off. Thus, a cylindrical hollow molded article open at each end, such as, e.g., a constant velocity joint boot, is obtained.

Description

明 細 書  Specification
中空成形品の射出成形法および射出成形金型並びに樹脂製ブーツ 技術分野  Injection molding method for hollow molded products, injection molds and resin boots
[0001] 本発明は、中空成形品の射出成形法および射出成形金型に関する。更に詳しくは [0001] The present invention relates to an injection molding method for a hollow molded article and an injection mold. More details
、両端が開口した筒状中空成形品、例えば、自動車の車軸に装着される等速ジョイ ントブーツ、ラックアンドピ-オンブーツ、シフトレバーに装着されるブーツ、二輪車の シャフトブーツなどとして用いられる、蛇腹部を有する榭脂製ブーツなどの中空成形 品を射出成形する方法およびそれに用いる金型に関する。本発明は、特に、熱可塑 性榭脂による前記中空成形品の射出成形法および射出成形金型に関する。また、 本発明は、熱可塑性エラストマ一を前記射出成形法により成形した榭脂製ブーツに 関する。 , Bellows parts used as cylindrical hollow molded products with open ends, for example, constant speed joint boots mounted on automobile axles, rack and pion boots, boots mounted on shift levers, shaft boots of motorcycles, etc. The present invention relates to a method for injection-molding a hollow molded product such as a coconut resin boot having a mold and a mold used therefor. The present invention particularly relates to an injection molding method and an injection mold for the hollow molded product using thermoplastic resin. The present invention also relates to a resin boot made by molding a thermoplastic elastomer by the injection molding method.
背景技術  Background art
[0002] 自動車用等速ジョイントブーツは、例えば自動車のトランスミッションとプロペラシャ フトとの間、ディファレンシャルギヤとドライブシャフトの間、ドライブシャフトとホイール との間など、入力駆動軸と出力駆動軸との速度差がなぐ等しい速度で回転する構 造のジョイント部分を覆うカバーである。この等速ジョイントブーツは、前記ジョイント部 分への異物の侵入を防止し、また潤滑油 (グリース)を封入する機能を有する。この等 速ジョイントブーツは、例えば、図 10に示すように、小径取付部 2と、大径取付部 3と、 両者を一体に連結する蛇腹部 4とを備えている。小径取付部 2は、シャフトの外周に 装着され、一方、大径取付部 3は、例えばトリポートタイプの等速ジョイントのような 3 個の凹部がある非円形な外周形状のアウターケースに装着される。蛇腹部 4は大径 取付部 3から小径取付部 2に向力つてその直径が順次小さくなり、全体にほぼ円錐台 形状をしている。前記のような自動車の車軸におけるジョイント部分は、高速で回転し ながら繰り返し屈曲される過酷な条件下で使用されるので、高速回転により発生する 遠心力によって膨張 (変形)しな!、強度 (耐振れ回り性)と、屈曲に耐える柔軟性との 両方が同時に求められる。  [0002] Constant velocity joint boots for automobiles are, for example, speeds between an input drive shaft and an output drive shaft, such as between a vehicle transmission and a propeller shaft, between a differential gear and a drive shaft, and between a drive shaft and a wheel. It is a cover that covers the joint part of the structure that rotates at the same speed with no difference. This constant velocity joint boot has a function of preventing foreign matter from entering the joint portion and enclosing lubricating oil (grease). For example, as shown in FIG. 10, the constant velocity joint boot includes a small-diameter mounting portion 2, a large-diameter mounting portion 3, and a bellows portion 4 that connects the two together. The small-diameter mounting portion 2 is mounted on the outer periphery of the shaft, while the large-diameter mounting portion 3 is mounted on a non-circular outer shape outer case having three recesses such as a triport type constant velocity joint. The The bellows part 4 gradually decreases in diameter from the large-diameter attachment part 3 to the small-diameter attachment part 2 and has a substantially truncated cone shape as a whole. The joint part of the automobile axle as described above is used under severe conditions where it is repeatedly bent while rotating at high speed, so it does not expand (deform) due to the centrifugal force generated by high-speed rotation! Both swingability and flexibility to withstand bending are required at the same time.
[0003] 従来、前記等速ジョイントブーツは、一般的にクロロプレンゴムの射出成形により製 造されていた (特許文献 1)。しかし、クロロプレンゴムは加硫ゴムでありリサイクルが出 来ない。そこで、リサイクル可能なポリエステル系榭脂のブロー成形によるブーツが使 用されるようになってきた。しかし、一般にポリエステル系榭脂製ブーツは、硬くて脆く 、柔軟性に欠けるため、特に、高速で回転しながら繰り返し屈曲されるという過酷な条 件下で使用される等速ジョイント用ブーツなどの用途では耐久性に問題がある。即ち 、硬くて脆ぐ柔軟性に欠けるポリエステル系榭脂で等速ジョイント用ブーツを製造す るには、等速ジョイントブーツに要求される柔軟性を満足するために、蛇腹部に山部 と谷部を多段に形成する必要がある。しかし、山部と谷部を多段に形成すると、谷部 の曲率半径力 S小さくなり、繰り返し屈曲されると亀裂が入り易ぐ破断の原因となるの で、耐久性 (疲労性）に問題がある。 [0003] Conventionally, the constant velocity joint boot is generally manufactured by injection molding of chloroprene rubber. (Patent Document 1). However, chloroprene rubber is a vulcanized rubber and cannot be recycled. Therefore, boots made of recyclable polyester resin blow molding have come to be used. In general, however, polyester-based rosin boots are hard and brittle and lack flexibility, so they are used especially as constant-velocity joint boots that are used under the severe conditions of being bent repeatedly while rotating at high speed. Then there is a problem with durability. That is, in order to manufacture a constant velocity joint boot with a polyester-based resin that is hard and brittle and lacks flexibility, in order to satisfy the flexibility required for the constant velocity joint boot, It is necessary to form the part in multiple stages. However, if the crest and trough are formed in multiple stages, the curvature radius force S of the trough is reduced, and if it is repeatedly bent, it can cause cracks to easily break, so there is a problem in durability (fatigue). is there.
また、熱可塑性榭脂の射出成形により製造された榭脂製ブーツも知られて ヽる (例 えば、特許文献 2〜5参照。 )0熱可塑性榭脂の射出成形により、例えば等速ジョイン ト用ブーツなどの蛇腹部を有する中空成形品を成形する方法としては、開閉可能に 分割されたキヤビティ金型と、該キヤビティ金型内に配置されるコア金型とからなる成 形金型を用い、前記キヤビティ金型とコア金型との間に形成される成形空間内に、溶 融した熱可塑性榭脂を射出、充填する方法がある。この射出成形法は、例えば図 15 (a)に示すような、一対の分割型 101a、 101bからなるキヤビティ金型 101とコア金型 102とで形成される成形空間 103内に、注入ノズル 104から溶融状態の熱可塑性榭 脂を射出して、一端が閉止された中空成形品 Pを成形する。成型後、図 15 (b)に示 すように、キヤビティ金型 101 (101a、 101b)を開くとともに、コア金型 102に設けた 空気吹出穴 105から、コア金型 102に外嵌されている中空成形品 Pの内部に、高圧 空気を吹き付けて、中空成形品 Pの蛇腹部の弾性変形を利用して中空成形品 Pを膨 張させるとともに、コア金型 102から押し出す。しかし、この方法では、中空成形品 P を膨張させて、蛇腹部における谷部がコア金型 101における山部を乗り越えるように して中空成形品 Pをコア金型 102から無理矢理引き抜くので、金型から取り出された 中空成形品 Pに伸びや歪みが生じ、金型の設計寸法と製品との寸法とがー致しない という問題がある。この問題を解決する方法として、コア金型を分割して成形品から引 き抜くようにして、成形品を無理に引き抜かないようにする方法も知られている。しか し、この方法では、成形金型の構造が複雑となるうえに、成形作業も繁雑となる。また 、外型 (キヤビティ金型)とコア金型を成形品の高さ方向を基準として、最終成形品寸 法の伸長相当分寸法だけ圧縮した状態の寸法に予め設定しておき、成形、離型後、 成形品を所定寸法に拡大する方法が提案されている（特許文献 2参照。 )0しかし、こ のように脱型時の伸長相当分寸法だけ圧縮した状態の寸法に成形するという方法は 、伸長相当分寸法の設定が困難で、最終製品を設計どおりの寸法に成形することは 容易ではない。また、蛇腹部を螺旋状とし、成形品を回転させてコア金型から離型す る方法も提案されている (特許文献 3参照。；)。しかし、この方法では、蛇腹部が螺旋 状の成形品し力製造することができない。更に、蛇腹部の両端に装着部を備えたブ ーッの製造方法であって、目的とするブーツよりも軸方向に長い予備成形体を熱可 塑性榭材料を用いて成形する第一の工程と、装着部の開口を閉塞部材により気密 的に塞ぐ第二の工程と、蛇腹部の温度が所定温度以上であるときに前記予備成形 体の軸方向の長さが短くなるように該予備成形体内部に存在する気体を前記閉塞部 材に形成された連通口を経由して前記予備成形体内部から吸引し、その状態で所 定時間保持することによって、目的とするブーツを得る第三の工程とを含む方法が提 案されている（特許文献 4参照。；)。しかし、このように、成形後の成形品に外力を加え てその寸法を調整するような方法では、成形品に応力による歪みが残り、製造後に 寸法が変化するおそれがあるだけでなく、製造工程が煩雑となる。 Also known are resin boots manufactured by injection molding of thermoplastic resin (see, for example, Patent Documents 2 to 5). 0 Constant velocity joints by injection molding of thermoplastic resin, for example. As a method of forming a hollow molded article having a bellows portion such as a boot for a boot, a molding die comprising a cavity die divided so as to be openable and closable and a core die disposed in the cavity die is used. There is a method of injecting and filling molten thermoplastic resin into a molding space formed between the cavity mold and the core mold. In this injection molding method, for example, as shown in FIG. 15 (a), an injection nozzle 104 is provided in a molding space 103 formed by a cavity mold 101 consisting of a pair of split molds 101a and 101b and a core mold 102. A molten thermoplastic resin is injected to form a hollow molded product P with one end closed. After molding, as shown in FIG. 15 (b), the cavity mold 101 (101a, 101b) is opened, and it is externally fitted to the core mold 102 from the air blowing hole 105 provided in the core mold 102. High-pressure air is blown into the hollow molded product P, and the hollow molded product P is expanded using the elastic deformation of the bellows portion of the hollow molded product P and extruded from the core mold 102. However, in this method, since the hollow molded product P is inflated so that the valleys in the bellows part climb over the peaks in the core mold 101, the hollow molded product P is forcibly pulled out of the core mold 102. There is a problem that the hollow molded product P taken out from the product is stretched or distorted, and the design dimensions of the mold do not match the product dimensions. As a method for solving this problem, there is also known a method in which the core mold is divided and pulled out from the molded product so that the molded product is not pulled out excessively. Only However, this method complicates the structure of the molding die and makes the molding operation complicated. Also, the outer mold (cavity mold) and the core mold are preliminarily set to dimensions that are compressed by an amount corresponding to the extension of the final molded product dimension based on the height direction of the molded product, and then molded, separated. A method for enlarging a molded product to a predetermined size after molding has been proposed (refer to Patent Document 2). 0 However, a method of molding into a size that is compressed by the size corresponding to the elongation at the time of demolding. However, it is difficult to set the dimensions corresponding to elongation, and it is not easy to mold the final product to the dimensions as designed. There has also been proposed a method in which the bellows portion is formed in a spiral shape, and the molded product is rotated to release from the core mold (see Patent Document 3). However, with this method, the bellows part cannot be manufactured as a spiral molded product. Furthermore, a method of manufacturing a boot having attachment portions at both ends of the bellows portion, the first step of forming a preform, which is longer in the axial direction than the intended boot, using a thermoplastic material. A second step of hermetically closing the opening of the mounting portion with a closing member; and when the temperature of the bellows portion is equal to or higher than a predetermined temperature, the preformed body is shortened in the axial direction. The third step of obtaining the target boot by sucking the gas present inside from the inside of the preformed body through the communication port formed in the closed member and holding it in that state for a predetermined time (See Patent Document 4;). However, in this way, the method of adjusting the dimensions by applying external force to the molded product after molding does not only cause distortion due to stress in the molded product, which may change the size after manufacturing, but also the manufacturing process. Becomes complicated.
また、従来、榭脂製ブーツのような蛇腹部を有する筒状の中空成形品の製造に際 し、図 15に示すような、キヤビティ金型 101およびコア金型 102から形成される成形 空間 103に溶融した熱可塑性榭脂を射出する場合には、注入ノズル 104から、例え ば、図 16 (a)、（b)に示すような、ダイレクトゲートまたはディスクゲートと呼ばれる平面 状のゲート 106A、 106Bを介して成形空間 103内へ溶融した熱可塑性榭脂が射出 されていた。し力し、これらの平面状ゲート 106A、 106Bには、図 16 (a)、（b)に示す ように、榭脂流動部に角部 Xや、射出された榭脂材料 Mが金型内面に衝突する部分 Yが存在するため、射出された榭脂材料 Mが、これらの部分 Xや部分 Yで乱流になり ほしれる）、成形品の外観に榭脂の流れムラやウエルドラインなどが発生しやすい。更 に、成形後、コア金型 102から成形品 P内部に高圧空気を吹き付けて脱型する場合 、図 16 (c)、 （d)に示すように、中空成形品 Pの蓋となる平面状の部分 cに高圧空気 が吹き付けられるため、成形品 Pの内部に均一に圧力が力からず、エッジ効果により 、蓋となる部分 cが破れ、破れた部分から高圧空気が漏れて脱型不能となるおそれが ある。また、蓋となる部分 c (金型ではゲート 106A、 106Bの部分)の厚みを増し、破 れを防いでも、平面状の蓋 c部分の内面に吹き付けられ、成形品 P内に圧入される空 気がコア金型 102と成形品 Pとの間に均一にまわらず、コア金型 102から成形品 Pの 片側だけが脱型する脱型不良が発生するおそれがある。 Conventionally, when manufacturing a cylindrical hollow molded article having a bellows portion such as a greave boot, a molding space 103 formed from a cavity mold 101 and a core mold 102 as shown in FIG. In the case of injecting molten thermoplastic resin into a flat gate 106A, 106B called direct gate or disk gate as shown in FIGS. 16 (a) and 16 (b), for example, from the injection nozzle 104. The molten thermoplastic resin was injected into the molding space 103 via As shown in FIGS. 16 (a) and 16 (b), the planar gates 106A and 106B have a corner X and an injected resin material M on the inner surface of the mold as shown in FIGS. There is a part Y that collides with the resin, so that the injected resin material M will become turbulent in these parts X and Y), and there will be uneven flow of the resin and weld lines on the appearance of the molded product. Likely to happen. Furthermore, after molding, when high-pressure air is blown from the core mold 102 into the molded product P, the mold is removed. As shown in FIGS. 16 (c) and 16 (d), since high-pressure air is blown onto the flat portion c that becomes the lid of the hollow molded product P, pressure is not uniformly applied to the inside of the molded product P. Due to the edge effect, there is a possibility that the part c serving as the lid is torn, and high pressure air leaks from the torn part and cannot be removed. In addition, even if the thickness of the part c (the gate 106A, 106B in the mold) is increased and the breakage is prevented, it is blown onto the inner surface of the flat lid c part and is pressed into the molded product P. There is a risk that the mold will not be uniformly distributed between the core mold 102 and the molded product P, and a demolding failure in which only one side of the molded product P is removed from the core mold 102 may occur.
[0006] また、熱可塑性榭脂の射出成形によって製造された榭脂製ブーツのうち、特に柔 軟性に富む熱可塑性エラストマ一製のブーツでは、蛇腹部の肉厚が薄いと、回転時 の遠心力により応力が集中する山部や谷部に亀裂が入り、ブーツが破損したり、ブー ッが膨張して周囲のものに触れたりするおそれがある。このような遠心力によるブーツ の破損や膨張を防止するには、図 10に示す谷部 5や山部 6の肉厚を厚くすればよい 。し力 蛇腹部 4の肉厚を厚くすると蛇腹部 4が硬くなり、柔軟性および耐久性に問題 がでる。くわえて、蛇腹部 4の肉厚を厚くすると成形材料の使用量も増加し、コストアツ プにもなる。このような等速ジョイントブーツの耐久性を改良する方法として、蛇腹部（ ベローズ部）における山部と谷部の肉厚比、山部の曲率半径、ピッチ比率などの各 種設計要素の数値に基づき特性値を演算して限界特性値と比較することで前記設 計要素の数値を設定する方法が提案されている (特許文献 6参照)。しかしながら、ク ロロプレンゴム製と同等の柔軟性および耐久性を備えた具体的な榭脂製ブーツの提 供には至っていない。 [0006] Further, among the boots made of thermoplastic resin manufactured by injection molding of thermoplastic resin, especially in the boot made of thermoplastic elastomer having high flexibility, if the thickness of the bellows portion is thin, the centrifugal force during rotation is reduced. There is a risk of cracks in the peaks and valleys where stress is concentrated due to force, and the boots may be damaged, or the boots may expand and touch the surroundings. In order to prevent the boot from being damaged or expanded due to the centrifugal force, the thickness of the valley 5 and the peak 6 shown in FIG. 10 may be increased. Strength If the thickness of the bellows part 4 is increased, the bellows part 4 becomes hard, which causes problems in flexibility and durability. In addition, increasing the thickness of the bellows part 4 increases the amount of molding material used, which increases costs. As a method of improving the durability of such constant velocity joint boots, numerical values of various design factors such as the thickness ratio of the peak and valley in the bellows (bellows), the radius of curvature of the peak, and the pitch ratio are used. A method of setting a numerical value of the design element by calculating a characteristic value based on the result and comparing it with a limit characteristic value has been proposed (see Patent Document 6). However, it has not yet provided a specific rosin boot with the same flexibility and durability as croprene rubber.
[0007] このように、種々の提案はなされているが、蛇腹部を有する筒状の中空成形品を熱 可塑性榭脂、とりわけ熱可塑性エラストマ一のように、柔軟性に優れ、ジョイント用ブ ーッとして好適な榭脂材料力も成形することは困難であった。そこで、現在のところ、 リサイクルができな 、加硫ゴムであるクロロプレンゴムが主に用いられて 、る。  [0007] As described above, although various proposals have been made, a cylindrical hollow molded article having a bellows portion is excellent in flexibility, like a thermoplastic resin, particularly a thermoplastic elastomer, and has a joint boot. It was difficult to mold a suitable resin material strength. Therefore, at present, chloroprene rubber, which is a vulcanized rubber, that cannot be recycled is mainly used.
[0008] 特許文献 1 :特開平 4 92166号公報  Patent Document 1: Japanese Patent Application Laid-Open No. 4 92166
特許文献 2：特開平 6 - 190878号公報  Patent Document 2: JP-A-6-190878
特許文献 3：特開平 10— 73162号公報  Patent Document 3: Japanese Patent Laid-Open No. 10-73162
特許文献 4：特開平 11― 257490号公報 特許文献 5：特開 2003 - 329059号公報 Patent Document 4: Japanese Patent Laid-Open No. 11-257490 Patent Document 5: Japanese Patent Laid-Open No. 2003-329059
特許文献 6：特開 2001— 116057号公報  Patent Document 6: Japanese Patent Laid-Open No. 2001-116057
発明の開示  Disclosure of the invention
発明が解決しょうとする課題  Problems to be solved by the invention
[0009] 本発明は、上記の点に鑑み、筒状の中空成形品、とくに蛇腹部を備えた、例えば 等速ジョイント用ブーツなどの中空成形品を熱可塑性榭脂の射出成形により製造す るに際して、成形時の樹脂の流れムラが生ずることなく良好な外観を有し、また高圧 空気による脱型時の変形が小さぐ寸法精度、寸法安定性に優れ、し力もリサイクル 可能な中空成形品を、生産性よく製造可能とすることを目的とする。また、本発明は、 柔軟性に優れる素材である熱可塑性エラストマー榭脂の射出成形により製造される 榭脂製ブーツであって、熱可塑性エラストマ一の柔軟性を損なうことなぐ耐久性に 優れる榭脂製ブーツを提供せんとするものである。更に、蛇腹部の肉厚が薄くとも柔 軟性および耐久性に優れ、等速ジョイントブーツとして過酷な条件下でも使用可能な 榭脂製ブーツを提供せんとするものである。  [0009] In view of the above points, the present invention manufactures a hollow cylindrical molded article, particularly a hollow molded article having a bellows portion, such as a constant velocity joint boot, by injection molding of thermoplastic resin. At this time, a hollow molded product that has a good appearance without causing uneven flow of resin during molding, is small in deformation when demolded by high-pressure air, has excellent dimensional accuracy and dimensional stability, and can recycle the force. The purpose is to enable production with high productivity. The present invention also relates to a boot made of a resin manufactured by injection molding of a thermoplastic elastomer resin, which is a material having excellent flexibility, and excellent in durability without impairing the flexibility of the thermoplastic elastomer. It is intended to provide boots made of. Furthermore, the present invention is to provide a rosin boot that is excellent in flexibility and durability even when the bellows portion is thin, and can be used as a constant velocity joint boot even under severe conditions.
課題を解決するための手段  Means for solving the problem
[0010] 本発明者は、上記の目的を達成するため、鋭意研究を重ねた結果、蛇腹部を有す る筒状の中空成形品を熱可塑性榭脂の射出成形により製造するに際して、成形金 型の成形空間へ溶融した熱可塑性榭脂を射出する際のゲートとして、ドーム状ゲート を採用することにより、成形時の樹脂の流れムラが発生せず、かつ脱型時には、前記 ドーム状ゲート部分に成形されるドーム状の蓋となる部分に高圧空気を吹き付けるこ とで、成形品内部に吹き込まれる高圧空気による圧力が成形品内部に均一に作用し 、成形品をコア金型力 容易に脱型可能であるとの知見を得、本発明を完成するに 至った。  [0010] As a result of intensive studies to achieve the above-mentioned object, the present inventor has found that when a cylindrical hollow molded product having a bellows portion is manufactured by injection molding of thermoplastic resin, By adopting a dome-shaped gate as a gate for injecting molten thermoplastic resin into the molding space of the mold, there is no uneven flow of the resin during molding, and the dome-shaped gate portion at the time of demolding By blowing high-pressure air onto the part of the dome-shaped lid that is molded into a uniform pressure, the pressure of the high-pressure air blown into the molded product acts uniformly inside the molded product, and the core mold force is easily removed. The knowledge that it was moldable was obtained, and the present invention was completed.
[0011] 即ち、本発明に係る中空成形品の射出成形法は、開閉可能に分割されたキヤビテ ィ金型と、該キヤビティ金型内に配置されるコア金型とからなる成形金型の前記キヤビ ティ金型とコア金型との間に形成される成形空間内に、溶融した熱可塑性榭脂を射 出、充填して、両端に開口した筒状の中空成形品を製造する射出成形法であって、 該成形空間内で成形される中空成形品の一方の開口端縁から該成形品の軸方向 外側に突出するように前記金型の成形空間に連通して設けたドーム状ゲートの頂点 部分の 1箇所から、成形される中空成形品の軸方向に向力つて溶融した熱可塑性榭 脂を射出し、該ドーム状ゲートを介して成形空間内に熱可塑性榭脂を射出、充填し て、一端が閉止された中空成形品を成形し、成形後、前記キヤビティ金型を開くととも に、コア金型に外嵌されている中空成形品の内部に、該コア金型におけるドーム状 ゲートの頂点部分力 高圧空気を成形品の軸方向に向かって吹き付けることにより、 コア金型から成形品を取り出すことを特徴とする。 [0011] That is, the method for injection molding a hollow molded product according to the present invention includes a mold that includes a cavity mold that can be opened and closed and a core mold that is disposed in the cavity mold. An injection molding method in which a molten thermoplastic resin is injected and filled into a molding space formed between a cavity mold and a core mold to produce a cylindrical hollow molded product opened at both ends. An axial direction of the molded product from one opening edge of the hollow molded product molded in the molding space A thermoplastic resin melted in the axial direction of the hollow molded product to be molded is injected from one point of the apex of the dome-shaped gate provided in communication with the molding space of the mold so as to protrude outward. Then, a thermoplastic resin is injected and filled into the molding space through the dome-shaped gate to form a hollow molded product with one end closed. After molding, the cavity mold is opened and the core is opened. Inside the hollow molded product that is externally fitted to the mold, the apex partial force of the dome-shaped gate in the core mold is blown out in the axial direction of the molded product to take out the molded product from the core mold. It is characterized by that.
本発明に係る射出成形法の好ましい実施態様としては、以下のものある。  Preferred embodiments of the injection molding method according to the present invention are as follows.
前記ドーム状ゲートが略半球状であり、該略半球状ゲートの頂点部分に設けた注 入孔から溶融した熱可塑性榭脂を射出する。  The dome-shaped gate has a substantially hemispherical shape, and molten thermoplastic resin is injected from an injection hole provided at the apex of the substantially hemispherical gate.
溶融した熱可塑性榭脂を、前記ドーム状ゲートから前記成形空間内で成形される 成形品の軸方向に向かって成形空間内へ射出、充填する。  The molten thermoplastic resin is injected and filled from the dome-shaped gate into the molding space in the axial direction of the molded product molded in the molding space.
前記中空成形品が、両端に開口した一対の環状取付部と、両者を一体に連結する 蛇腹部とを備える。  The hollow molded article includes a pair of annular mounting portions that are open at both ends, and a bellows portion that integrally connects the two.
前記中空成形品が、前記一対の取付部のうちの一方が他方に比べて大径であり、 成形金型における小径取付部側の開口端縁に設けたドーム状ゲートを介して成形 空間内へ溶融した熱可塑製榭脂を射出、充填する。  In the hollow molded product, one of the pair of mounting portions has a larger diameter than the other, and into the molding space via a dome-shaped gate provided at an opening edge on the small-diameter mounting portion side in the molding die. Injection and filling with molten thermoplastic resin.
前記中空成形品が、アウターケースに取り付けられる大径取付部と、シャフトに取り 付けられる小径取付部と、両者を一体に連結する蛇腹部とを備える等速ジョイント用 ブーツである。  The hollow molded article is a constant velocity joint boot including a large-diameter attachment portion attached to an outer case, a small-diameter attachment portion attached to a shaft, and a bellows portion integrally connecting the two.
前記熱可塑性榭脂が、熱可塑性エラストマ一である。  The thermoplastic resin is a thermoplastic elastomer.
前記熱可塑性エラストマー榭脂が、アクリル系ブロック共重合体 (A)を含む。  The thermoplastic elastomer resin contains an acrylic block copolymer (A).
前記熱可塑性エラストマー榭脂が、アクリル系ブロック共重合体 (A)と、ォレフィン 系熱可塑性エラストマ一（B)を含む熱可塑性エラストマ一組成物である。  The thermoplastic elastomer resin is a thermoplastic elastomer composition containing an acrylic block copolymer (A) and an olefin thermoplastic elastomer (B).
熱可塑性エラストマ一組成物力 アクリル系ブロック共重合体 (A) 100重量部に対 し、ォレフン系熱可塑性エラストマ一（B) 50〜600重量部および相溶化剤（C) 5〜5 Composition strength of thermoplastic elastomer Acrylic block copolymer (A) 50 to 600 parts by weight of olefin-based thermoplastic elastomer (B) and compatibilizer (C) 5 to 5 per 100 parts by weight
0重量部を含む。 Contains 0 parts by weight.
前記アクリル系ブロック共重合体 (A)力 アクリル系重合体ブロック（a)を 50〜90重 量％含有し、メタアクリル系重合体ブロック (b)を 50〜： LO重量％含有する。 The acrylic block copolymer (A) force 50 to 90 times the acrylic polymer block (a) The methacrylic polymer block (b) is contained in an amount of 50%: LO wt%.
前記アクリル系重合体ブロック（a)およびメタアクリル系重合体ブロック (b)の少なく とも一方の重合体ブロックに反応性官能基 (c)を有する。  At least one of the acrylic polymer block (a) and the methacrylic polymer block (b) has a reactive functional group (c).
前記ォレフィン系熱可塑性エラストマ一（B)力 ォレフィン榭脂中で EPDMゴムまた はアクリロニトリル.ブタジエンゴムを動的に架橋したものである。  EPolefin rubber or acrylonitrile-butadiene rubber is dynamically crosslinked in the olefin-based thermoplastic elastomer (B) olefin resin.
更に、前記相溶化剤 (C)が、エポキシ基を含有するォレフイン系熱可塑性榭脂であ る。  Furthermore, the compatibilizer (C) is an olefin-based thermoplastic resin containing an epoxy group.
[0013] また、本発明に係る中空成形品の射出成形金型は、開閉可能に分割されたキヤビ ティ金型と、該キヤビティ金型内に配置されるコア金型とからなり、前記キヤビティ金型 とコア金型との間に形成される成形空間内に、溶融した熱可塑性榭脂を射出、充填 して、両端に開口した筒状の中空成形品を製造する射出成形金型であって、前記成 形空間から、該成形空間内で成形される成形品の軸方向外側に突出するようにドー ム状ゲートを設け、該ドーム状ゲートの頂点部分に位置するキヤビティ金型に 1箇所 の注入孔を設けるとともに、前記コア金型におけるドーム状ゲートの頂点部分内面に [0013] In addition, an injection mold for a hollow molded product according to the present invention includes a cavity mold that is divided so as to be openable and closable, and a core mold that is disposed in the cavity mold. An injection mold for injecting and filling molten thermoplastic resin into a molding space formed between a mold and a core mold to produce a cylindrical hollow molded product opened at both ends. A dome-shaped gate is provided so as to protrude from the molding space to the outside in the axial direction of the molded product molded in the molding space, and one cavity mold is positioned at the apex of the dome-shaped gate. In addition to providing an injection hole, on the inner surface of the apex of the dome-shaped gate in the core mold
、高圧空気供給手段に連通する開閉可能な吹出口を設けてなり、溶融した熱可塑性 榭脂を前記注入孔から前記ドーム状ゲートを介して成形空間内に射出、充填して中 空成形品を成形した後、前記キヤビティ金型を開くとともに前記吹出口を開放して高 圧空気供給手段から前記吹出口を介して中空成形品の内部に高圧空気を吹き付け て、コア金型力も成形品を取り出すように構成したことを特徴とする。 An openable and closable outlet that communicates with the high-pressure air supply means is provided, and a molten thermoplastic resin is injected into the molding space from the injection hole through the dome-shaped gate and filled into a hollow molded product. After molding, the cavity mold is opened and the blowout opening is opened, and high pressure air is blown from the high pressure air supply means to the inside of the hollow molded article through the blowout opening, and the core mold force is also taken out. It is configured as described above.
[0014] 本発明に係る射出成形金型の好ましい実施態様には、以下のものがある。  [0014] Preferred embodiments of the injection mold according to the present invention include the following.
前記ドーム状ゲートが略半球状であり、該略半球状ゲートの頂点部分に、成形され る中空成形品の軸方向にのびる注入孔を設ける。  The dome-shaped gate is substantially hemispherical, and an injection hole extending in the axial direction of the hollow molded article to be molded is provided at the apex of the substantially hemispherical gate.
前記ドーム状ゲートにおける前記成形空間への開口端縁を、成形空間内で成形さ れる成形品の軸方向と同方向となるように形成する。  An opening edge to the molding space in the dome-shaped gate is formed so as to be in the same direction as the axial direction of the molded product molded in the molding space.
前記コア金型の軸心部分に、その軸方向に貫通し、高圧空気供給手段に連結され る通気孔を設け、該通気孔の先端部を前記吹出口とし、前記通気孔内に、先端を前 記ドーム状ゲートに臨ませて、コア金型の軸方向に摺動する開閉軸を設け、該開閉 軸により前記吹出口を開閉可能とする。 前記通気孔内部の内周面に、軸方向に伸びる単数または複数の通気溝を設け、 前記開閉軸を、その先端が前記通気溝を設けた位置にくるまで後退させて、吹出口 を開口するとともに、通気孔から前記通気溝および吹出口を介して高圧空気を成形 品の内部に吹き付け可能とする。 A vent hole penetrating in the axial direction of the core mold and connected to the high-pressure air supply means is provided in the axial center portion of the core mold, and the tip end portion of the vent hole serves as the outlet, and the tip end is provided in the vent hole. An opening / closing shaft that slides in the axial direction of the core mold is provided facing the dome-shaped gate, and the air outlet can be opened and closed by the opening / closing shaft. One or a plurality of ventilation grooves extending in the axial direction are provided on the inner peripheral surface inside the ventilation hole, and the opening / closing shaft is retracted until its tip comes to the position where the ventilation groove is provided to open the air outlet. At the same time, high-pressure air can be blown into the molded product from the ventilation hole through the ventilation groove and the outlet.
両端に開口した一対の環状取付部と、両者を一体に連結する蛇腹部とを備える中 空成形品を成形するための成形金型である。  A molding die for molding a hollow molded product including a pair of annular mounting portions opened at both ends and a bellows portion integrally connecting the two.
前記一対の取付部のうちの一方が他方に比べて大径である中空成形品を成形す るための成形金型であり、成形空間における小径取付部の開口端縁に前記ドーム状 ゲートを設ける。  A molding die for molding a hollow molded product in which one of the pair of mounting portions has a larger diameter than the other, and the dome-shaped gate is provided at the opening edge of the small-diameter mounting portion in the molding space. .
アウターケースに取り付けられる大径取付部と、シャフトに取り付けられる小径取付 部と、両者を一体に連結する蛇腹部とを備える等速ジョイント用ブーツを成形するた めの成形金型である。  A molding die for molding a constant velocity joint boot including a large-diameter attachment portion attached to an outer case, a small-diameter attachment portion attached to a shaft, and a bellows portion integrally connecting the two.
[0015] また、本発明に係る第 1の榭脂製ブーツは、上記の本発明に係る射出成形法により 、両端に開口した一対の取付部と、両者を一体に連結する蛇腹部とを備え、一方の 取付部側に設けたゲートから金型成形空間内へ熱可塑性エラストマ一榭脂を射出し て成形した榭脂製ブーツであって、前記蛇腹部における各谷部を、それぞれの谷部 に対して前記ゲート側の取付部寄りに隣り合う山部の厚みと同じか、それより厚く形成 し、かつ少なくとも一部の谷部を前記隣り合う山部より厚く形成したことを特徴とする。  [0015] Further, the first resin-made boot according to the present invention includes a pair of attachment portions opened at both ends and a bellows portion integrally connecting the two by the injection molding method according to the present invention. A boot made of resin made by injecting a thermoplastic elastomer resin from a gate provided on one mounting portion side into a mold forming space, wherein each valley portion in the bellows portion is On the other hand, it is characterized in that it is formed to be equal to or thicker than the adjacent peak portion near the gate side mounting portion, and at least part of the valley portion is formed thicker than the adjacent peak portion.
[0016] 本発明で、蛇腹部とは、当該ブーツの縦断面において、ブーツの外側に向けて張り 出した凸部とブーツの内側に向けて張り出した凹部とが交互に連続した形状をいい、 ブーツ外周面に独立した複数の凸条部と凹条部とが交互に形成されたものの他、ブ ーッ外周面に互いに隣り合う各 1条の凸条部と凹条部とが螺旋状に連続して形成さ れたものも含む。また、前記山部とは、前記蛇腹部の凸部（凸条部）のことであり、前 記谷部とは、前記蛇腹部の凹部（凹条部）のことである。  In the present invention, the bellows portion refers to a shape in which a convex portion projecting toward the outside of the boot and a concave portion projecting toward the inside of the boot are alternately continued in the longitudinal section of the boot. In addition to a plurality of independent ridges and ridges formed alternately on the outer peripheral surface of the boot, each ridge and groove adjacent to each other on the outer peripheral surface of the boot are spirally continuous. Including those formed as a result. The peak portion is a convex portion (ridge portion) of the bellows portion, and the valley portion is a concave portion (concave portion) of the bellows portion.
[0017] 前記榭脂製ブーツの好ましい実施形態では、一対の取付部のうちの一方が他方に 比べて大径であり、成形金型における、小径取付部側に設けたゲートから熱可塑製 エラストマ一榭脂を射出して成形してなるものである。特に好ましい実施形態は、ァゥ ターケースに取り付けられる大径取付部と、シャフトに取り付けられる小径取付部と、 両者を一体に連結する蛇腹部とを備える等速ジョイント用ブーツである。 [0017] In a preferred embodiment of the rubber boot, one of the pair of attachment portions has a larger diameter than the other, and a thermoplastic elastomer is formed from a gate provided on the small diameter attachment portion side in the molding die. It is formed by injecting a single fat. Particularly preferred embodiments include a large diameter attachment that is attached to the outer case, a small diameter attachment that is attached to the shaft, It is a boot for constant velocity joints provided with the bellows part which connects both together.
[0018] また、本発明者らは、榭脂製ブーツについて更に検討を重ねた結果、上記した本 発明に係る射出成形法により、熱可塑性エラストマー榭脂にて射出成形した榭脂製 ブーツにおいて、大径取付部と小径取付部と、両者を一体に連結してなる蛇腹部を 備え、蛇腹部が大径取付部力も小径取付部に向力つてその直径が順次小さぐ蛇腹 部における大径取付部に最も近く位置する谷部の内径を、従来のものよりも小さくす ることで、蛇腹部の肉厚を薄くしても、等速ジョイントブーツのような高速で回転しなが ら繰り返し屈曲される過酷な条件下での使用にも耐えうる柔軟性および耐久性に優 れた榭脂製ブーツを得ることができること、更に前記谷部の曲率半径を大きくすること で、更に耐久性が向上することを知見し、本発明を完成するに至った。  [0018] Further, as a result of further investigations on the resin-made boots, the present inventors, in the resin-made boots injection-molded with thermoplastic elastomer resin, by the injection molding method according to the present invention described above, A large-diameter mounting part and a small-diameter mounting part are provided, and a bellows part formed by integrally connecting the two parts is provided. By making the inner diameter of the valley located closest to the part smaller than the conventional one, even if the wall thickness of the bellows is reduced, it bends repeatedly while rotating at a high speed like a constant velocity joint boot. It is possible to obtain a boot made of resin with excellent flexibility and durability that can withstand use under harsh conditions, and the durability is further improved by increasing the curvature radius of the valley. To complete the present invention Was Tsu.
[0019] 即ち、本発明に係る第 2の榭脂製ブーツは、大径取付部と小径取付部との、両端に 開口した一対の取付部と、前記大径取付部と小径取付部とを一体に連結し、前記大 径取付部から小径取付部に向かってその直径が順次小さくなる蛇腹部とを備え、熱 可塑性エラストマー榭脂にて射出成形してなる榭脂製ブーツであって、前記大径取 付部に最も近い谷部の内径 dを、蛇腹部における小径取付部側の開口径 Dより大き  That is, the second resin boot according to the present invention comprises a pair of attachment portions opened at both ends of a large diameter attachment portion and a small diameter attachment portion, and the large diameter attachment portion and the small diameter attachment portion. And a bellows portion that is integrally connected and has a bellows portion that gradually decreases in diameter from the large-diameter attachment portion toward the small-diameter attachment portion. The inner diameter d of the valley closest to the large-diameter mounting part is larger than the opening diameter D on the small-diameter mounting part side in the bellows part.
1 ぐかつ蛇腹部における大径取付部側の開口径 Dの 60%以下とするとともに、前記  1 60% or less of the opening diameter D on the large-diameter mounting part side of the ridged bellows part,
2  2
大径取付部に最も近い谷部の曲率半径を 2mn！〜 10mmとしたことを特徴とする。前 記谷部の曲率半径とは、前記ブーツの縦断面において、蛇腹部における内側に向 けて張り出した凹部の内面の曲率半径のことである。  The radius of curvature of the valley closest to the large diameter mounting part is 2mn! It is characterized by ~ 10mm. The curvature radius of the above-mentioned valley portion is the curvature radius of the inner surface of the concave portion protruding toward the inside of the bellows portion in the longitudinal section of the boot.
[0020] この第 2の榭脂製ブーツでは、前記大径取付部に最も近い山部の外径を、蛇腹部 における大径取付部側の開口径 Dより小さくすることが好ましい。また、前記蛇腹部 [0020] In the second boot made of resin, it is preferable that the outer diameter of the peak portion closest to the large-diameter mounting portion is smaller than the opening diameter D on the large-diameter mounting portion side in the bellows portion. Also, the bellows part
2  2
の肉厚は、 3mm以下が好ましい。更に、前記蛇腹部における大径取付部側の開口 縁に、軸芯に平行にのびる円筒状の周壁部を形成するとより好ましい。  The wall thickness is preferably 3 mm or less. Furthermore, it is more preferable to form a cylindrical peripheral wall portion extending in parallel with the shaft core at the opening edge of the bellows portion on the large diameter attachment portion side.
[0021] 本発明に係る榭脂製ブーツの射出成形に使用される熱可塑性エラストマー榭脂の 種類に特に限定はな 、が、 (A)アクリル系ブロック共重合体を含むものが好ま 、。 更には、（A)アクリル系ブロック共重合体と、（B)ォレフィン系熱可塑性エラストマ一を 含む熱可塑性エラストマ一が好ましい。特に、前記 (A)および (B)に加えて、更に (C )相溶化剤を含む熱可塑性エラストマ一組成物が好まし 、。 前記熱可塑性エラストマ一組成物の好ましい実施態様には、以下のものがある。[0021] There are no particular limitations on the type of thermoplastic elastomer resin used in the injection molding of the resin boot according to the present invention, but (A) one containing an acrylic block copolymer is preferred. Furthermore, a thermoplastic elastomer containing (A) an acrylic block copolymer and (B) an olefin thermoplastic elastomer is preferred. In particular, a thermoplastic elastomer composition containing (C) a compatibilizer in addition to (A) and (B) is preferred. Preferred embodiments of the thermoplastic elastomer composition include the following.
(A)アクリル系ブロック共重合体 100重量部に対し、（B)ォレフィン系熱可塑性エラ ストマー 50〜600重量部、（C)相溶化剤 5〜50重量部を含む。 (A) 50 to 600 parts by weight of (olefin) thermoplastic elastomer and (C) 5 to 50 parts by weight of a compatibilizing agent are included with respect to 100 parts by weight of the acrylic block copolymer.
前記 (A)アクリル系ブロック共重合体力 アクリル系重合体ブロック (a)およびメタァ クリル系重合体ブロック (b)からなり、少なくとも一方の重合体ブロックに反応性官能 基 (c)を有する。  (A) Acrylic block copolymer force The acrylic block (a) and the methacrylic polymer block (b) have a reactive functional group (c) in at least one of the polymer blocks.
前記アクリル系ブロック共重合体 (A)中の反応性官能基 (c)が、一般式（1)： [化 1]  The reactive functional group (c) in the acrylic block copolymer (A) has the general formula (1):
Figure imgf000012_0001
Figure imgf000012_0001
(式中、 R1は水素原子またはメチル基で、互いに同一でも異なっていてもよぐ pは 0 または 1の整数、 qは 0〜3の整数)で表わされる酸無水物基を含有する単位 (cl)お よび Zまたはカルボキシル基を含有する単位 (c2)を有する。 (Wherein R 1 is a hydrogen atom or a methyl group, and may be the same or different from each other, p is an integer of 0 or 1, q is an integer of 0 to 3) and a unit (c2) containing Z or a carboxyl group.
熱可塑性エラストマ一組成物力 アクリル系ブロック共重合体 (A)全体中に、カルボ キシル基を含有する単位 (c2)を 0. 1〜50重量％含有する。  Composition strength of thermoplastic elastomer The acrylic block copolymer (A) contains 0.1 to 50% by weight of units (c2) containing a carboxyl group.
前記アクリル系ブロック共重合体 (A)力 アクリル系重合体ブロック（a)を 50〜90重 量％含有し、メタアクリル系重合体ブロック (b)を 50〜： L0重量％含有する。  The acrylic block copolymer (A) force The acrylic polymer block (a) is contained in an amount of 50 to 90% by weight, and the methacrylic polymer block (b) is contained in an amount of 50 to L0% by weight.
前記アクリル系ブロック共重合体 (A)が、原子移動ラジカル重合により製造された ブロック共重合体である。  The acrylic block copolymer (A) is a block copolymer produced by atom transfer radical polymerization.
前記ォレフィン系熱可塑性エラストマ一（B)力 ォレフィン榭脂中で EPDMゴムまた はアクリロニトリル.ブタジエンゴムを動的に架橋したものである。  EPolefin rubber or acrylonitrile-butadiene rubber is dynamically crosslinked in the olefin-based thermoplastic elastomer (B) olefin resin.
前記相溶化剤 (C)が、エポキシ基を含有するォレフイン系熱可塑性榭脂ある。 発明の効果 The compatibilizer (C) is an olefin-based thermoplastic resin containing an epoxy group. The invention's effect
[0023] 本発明では、溶融した熱可塑性榭脂が、金型のドーム状ゲートから滑らかに成形空 間内へ充填され、榭脂の流れに乱れが発生して成形品の外観を損ねるということが ない。また、成形後には、コア金型に外嵌されている中空成形品の内部に、該コア金 型におけるドーム状ゲートの頂点部分から高圧空気を吹き付けて脱型するようにした ので、前記ドーム状ゲート部分力 圧入された空気は、成形されるドーム状の蓋部分 に吹き付けられた後、該ドーム状蓋部分の内面に沿って滑らかに吹き込まれてコア 金型と中空成形品との間に入り込み、成形品内部に高圧空気による圧力が均一に 作用し、コア金型から中空成形品を容易に取り出せる。このため、成形品が変形した り、成形品に余分な応力が残って歪みが発生するようなこともなぐ寸法安定性が高く 、かつ寸法変化の少ない成形品が得られる。また、分割方式のコア金型を採用した 場合のように金型構造が複雑となったり作業が繁雑となったりせず、良好な中空成形 品を生産性よく製造できる。なお、前記のようにドーム状の蓋が付いた状態に成形さ れた中空成形品は、成形後、前記ドーム状の蓋部分およびそれに連なった状態に成 形されるランナー部分などが切除されて、目的とする製品となる。  [0023] In the present invention, the molten thermoplastic resin is smoothly filled into the molding space from the dome-shaped gate of the mold, and the flow of the resin is disturbed to impair the appearance of the molded product. There is no. In addition, after the molding, the hollow molded product externally fitted to the core mold is demolded by blowing high-pressure air from the apex portion of the dome-shaped gate in the core mold. Gate partial force After the injected air is blown onto the dome-shaped lid part to be molded, it is smoothly blown along the inner surface of the dome-shaped lid part and enters between the core mold and the hollow molded product. The pressure of high-pressure air acts uniformly inside the molded product, and the hollow molded product can be easily removed from the core mold. For this reason, a molded product with high dimensional stability and little dimensional change can be obtained without deforming the molded product or leaving excessive stress in the molded product to cause distortion. In addition, the mold structure is not complicated and the work is not complicated as in the case of using a split core mold, and a good hollow molded product can be manufactured with high productivity. In addition, the hollow molded product molded with the dome-shaped lid as described above has the dome-shaped lid portion and the runner portion formed in a connected state cut off after molding. , Become the target product.
[0024] また、前記ドーム状ゲートの縦断面形状を略半球状とし、該略半球状ゲートの頂点 部分に設けた注入孔から溶融した熱可塑性榭脂を射出すると、射出される榭脂の流 れに発生する乱流ほしれ)をより確実に抑えられる。  [0024] Further, when the vertical cross-sectional shape of the dome-shaped gate is substantially hemispherical and molten thermoplastic resin is injected from an injection hole provided at the apex of the approximately hemispherical gate, the flow of injected resin is It is possible to more reliably suppress turbulent flow).
[0025] 前記ドーム状ゲートにおける、前記成形空間への開口端縁を、該成形空間内で成 形される成形品の軸方向と同方向となるように形成し、溶融した熱可塑性榭脂を、ド ーム状ゲートから、成形空間内で成形される成形品の軸方向に向力つて成形空間内 へ射出し充填すると、ドーム状ゲートから直線的に成形空間内へ樹脂が射出される ので、榭脂の流れに発生する乱流ほしれ)をより確実に抑えられる。  [0025] In the dome-shaped gate, an opening edge to the molding space is formed so as to be in the same direction as the axial direction of the molded product formed in the molding space, and the molten thermoplastic resin is formed. When the resin is injected from the dome-shaped gate into the molding space and filled in the axial direction of the molded product molded in the molding space, the resin is injected linearly from the dome-shaped gate into the molding space. Turbulent flow that occurs in the flow of rosin) can be suppressed more reliably.
[0026] 前記コア金型の軸芯部分に、その軸方向に貫通し、高圧空気の供給手段に連結さ れる通気孔を設け、該通気孔の先端部を前記吹出口とし、前記通気孔内に、先端を 前記ドーム状ゲートに臨ませて、コア金型の軸方向に摺動する開閉軸を設け、該開 閉軸により前記吹出口を開閉可能とすると、成形空間内への溶融した熱可塑性榭脂 の射出時に、吹出口内への榭脂の侵入を確実に防止でき、かつ成形後の成形品の 取り出し時には、キヤビティ金型の開放と同時に速やかに成形品内部に高圧空気を 吹き付けてコア金型から成形品を取り出すことができ、生産性よく成形できる。 [0026] A vent hole penetrating in the axial direction of the core mold of the core mold and connected to a high-pressure air supply means is provided, and the tip of the vent hole serves as the outlet, and the inside of the vent hole In addition, an opening / closing shaft that slides in the axial direction of the core mold is provided with the tip facing the dome-shaped gate, and the blowout port can be opened / closed by the opening / closing shaft. When plastic resin is injected, it can be reliably prevented from entering the air outlet and the molded product At the time of removal, the cavity mold can be opened at the same time as the high-pressure air is quickly blown into the molded product, and the molded product can be removed from the core mold.
[0027] 前記通気孔内部の内周面に、軸方向に伸びる単数または複数の通気溝を設け、 前記開閉軸を、その先端が前記通気溝を設けた位置にくるまで後退させて、吹出口 を開口し、前記通気孔から前記通気溝および吹出口を介して高圧空気を成形品の 内部に吹き付け可能とすると、成形空間内への溶融した熱可塑性榭脂の射出時に 吹出口内への榭脂の侵入を確実に防止できる。  [0027] One or more ventilation grooves extending in the axial direction are provided on the inner peripheral surface inside the ventilation hole, and the opening and closing shaft is retracted until its tip is located at the position where the ventilation groove is provided. When high-pressure air can be blown into the molded product from the vent hole through the vent groove and the blowout port, when the molten thermoplastic resin is injected into the molding space, the soot is blown into the blowout port. Infiltration of fat can be reliably prevented.
[0028] 本発明の射出成形法および成形金型は、蛇腹部を有する中空成形品であっても、 コア金型から無理なく成形品を取り出せるので、両端に開口した一対の環状取付部 と、両者を一体に連結する蛇腹部とを備える中空成形品の成形に好適である。  [0028] Even if the injection molding method and the molding die of the present invention is a hollow molded product having a bellows part, the molded product can be easily removed from the core mold, so a pair of annular mounting parts opened at both ends; It is suitable for molding of a hollow molded product having a bellows part that connects both together.
[0029] また、前記一対の取付部のうちの一方が他方に比べて大径である成形品を成形す るときは、成形金型における小径取付部の開口端縁に設けたドーム状ゲートを介して 成形空間内へ溶融した熱可塑製榭脂を射出、充填すると、前記ドーム状ゲートから 射出された溶融した熱可塑性榭脂が成形空間内に滑らかに充填され、ウエルドライ ンなどの発生しない良好な成形品を得られる。  [0029] Further, when molding a molded product in which one of the pair of mounting portions has a larger diameter than the other, a dome-shaped gate provided at the opening edge of the small-diameter mounting portion in the molding die is used. When the molten thermoplastic resin is injected and filled into the molding space, the molten thermoplastic resin injected from the dome-shaped gate is smoothly filled into the molding space, and no well line is generated. A good molded product can be obtained.
[0030] 特に、本発明の射出成形法及び射出成形金型は、熱可塑性榭脂の射出成形によ り、アウターケースに取り付けられる大径取付部と、シャフトに取り付けられる小径取 付部と、両者を一体に連結する蛇腹部と、を備える等速ジョイント用ブーツを製造す る場合に好適である。  [0030] In particular, the injection molding method and the injection mold of the present invention include a large-diameter attachment portion attached to the outer case and a small-diameter attachment portion attached to the shaft by injection molding of thermoplastic resin. This is suitable for manufacturing a constant velocity joint boot including a bellows portion that integrally connects the two.
[0031] また、熱可塑性エラストマー榭脂のような熱可塑性榭脂により蛇腹状のブーツを射 出成形する場合、蛇腹部の山部と谷部との厚みが同じときには、射出成形によるゥェ ルドラインは発生することは比較的少ない。しかし、柔軟な熱可塑性エラストマー榭脂 により製造されたブーツは、蛇腹部の肉厚が薄いと、例えば等速ジョイント用ブーツ のような回転部分に使用されると、遠心力によりブーツが外側に膨張し、破損しやす いという問題がある。これを防止するために、蛇腹部を肉厚に成形すると、回転時の 遠心力による膨張は防止できるが、蛇腹部の柔軟性が損なわれ、等速ジョイント用ブ ーッのように激しく屈曲された場合の耐久性に問題がある。また、山部のみを厚く形 成すれば、該厚肉の山部により、回転時の遠心力による膨れを防止でき、その分、谷 部の肉厚を薄くすれば、蛇腹部の柔軟性は確保できる。しかし、山部のみを厚くする と、ブーツの成形時に、成形金型の成形空間内に射出された榭脂は、厚肉の山部か ら、それに隣り合う薄肉の谷部へと流れることになる。このため、金型の成形空間内壁 力もの抵抗により樹脂の流れに乱れが生じて成形空間内に射出、充填される榭脂の 連続性が失われ、亀裂や破損の原因となるウエルドラインが発生しやすくなる。この 点、本発明に係る第 1の榭脂製ブーツは、蛇腹部における少なくとも一部の谷部を肉 厚に形成するので、回転時の遠心力による膨張が防止される。また、反対に山部の 肉厚は薄く形成するので、蛇腹部の柔軟性を損なうことがない。し力も、各谷部の肉 厚を、それに対してゲート側の取付部寄りに隣り合う山部の厚みと同じか、それより厚 く形成するので、ゲートから成形空間内へ射出された榭脂は、連続性が保たれたまま 、山部から、該山部と同じかそれよりも広い成形空間を有する厚肉の谷部へと円滑に 流れて充填され、厚肉の山部から薄肉の谷部へ向かって榭脂が充填される場合のよ うに、成形品の亀裂や破損の原因となるウエルドラインが発生せず、耐久性に優れた 榭脂製ブーツが得られる。 [0031] In addition, when the bellows-shaped boot is formed by injection molding using a thermoplastic resin such as a thermoplastic elastomer resin, if the thickness of the peak portion and the valley portion of the bellows portion is the same, a weld line by injection molding is used. Is relatively rare. However, if the boot made of a flexible thermoplastic elastomer resin is thin in the bellows part and used in a rotating part such as a constant velocity joint boot, the boot expands to the outside due to centrifugal force. However, it is easy to break. In order to prevent this, if the bellows part is formed thick, expansion due to centrifugal force during rotation can be prevented, but the flexibility of the bellows part is lost, and it is bent violently like a constant velocity joint boot If there is a problem with durability. In addition, if only the peak portion is formed thick, the thick peak portion can prevent swelling due to centrifugal force during rotation. If the thickness of the part is reduced, the flexibility of the bellows part can be secured. However, if only the crest is thickened, the resin injected into the molding space of the mold during the boot molding will flow from the thick crest to the adjacent thin trough. Become. For this reason, the flow of the resin is disturbed due to the resistance of the inner wall of the molding space of the mold, and the continuity of the resin injected and filled into the molding space is lost, resulting in weld lines that cause cracks and breakage. It becomes easy to do. In this respect, since the first resin-made boot according to the present invention forms at least a part of the valley portion in the bellows portion thickly, expansion due to centrifugal force during rotation is prevented. On the other hand, since the thickness of the mountain portion is thin, the flexibility of the bellows portion is not impaired. Also, the thickness of each trough is equal to or greater than the thickness of the adjacent peak near the mounting part on the gate side, so that the grease injected from the gate into the molding space Is filled and flows smoothly from the crest to a thick trough having a molding space equal to or larger than the crest while maintaining continuity. As in the case where the resin is filled toward the valley, a weld line that causes cracks and breakage of the molded product does not occur, and a resin boot having excellent durability can be obtained.
[0032] また、一般に等速ジョイントブーツなどの榭脂製ブーツは、大径取付部から小径取 付部に向力つて蛇腹部の直径が順次小さく形成されている。本発明に係る第 2の榭 脂製ブーツは、蛇腹部における谷部の内で最も内径が大きい、大径取付部に最も近 い谷部の内径 dを、蛇腹部における小径取付部側の開口径 Dより大きぐかつ蛇腹  [0032] Further, in general, a resin-made boot such as a constant velocity joint boot is formed such that the diameter of the bellows portion is sequentially reduced from the large-diameter mounting portion toward the small-diameter mounting portion. The second resin boot according to the present invention has an inner diameter d of the valley portion having the largest inner diameter among the valley portions in the bellows portion and closest to the large diameter attachment portion, and opening on the small diameter attachment portion side in the bellows portion. Larger than D and bellows
1  1
部における大径取付部側の開口径 Dの 60%以下と小さくしている。前記大径取付  The opening diameter is smaller than 60% of the opening D on the large-diameter mounting part side. Large diameter mounting
2  2
部に最も近い谷部の内径 dを小さくすることで、小径取付部に向力つてその直径が順 次小さく形成されているその他の谷部の内径も必然的に小さくなる。そして、各段の 谷部の内径が小さくなるほど回転時の角速度も小さくなり、各谷部に作用する遠心力 もそのぶん小さくなる。その結果、回転時にブーツが膨張しにくぐ耐久性にも優れる  By reducing the inner diameter d of the valley portion closest to the portion, the inner diameters of the other valley portions, whose diameters are gradually reduced by urging the small diameter mounting portion, are inevitably reduced. The smaller the inner diameter of the valley of each step, the smaller the angular velocity during rotation, and the smaller the centrifugal force acting on each valley. As a result, the boots are also resistant to swelling during rotation.
[0033] また、この榭脂製ブーツの蛇腹部の谷部のうちでは、大径取付部に最も近 、谷部 が最も内径が大きいことから、回転により最も大きな遠心力が作用する。そこで、前記 谷部の曲率半径を 2〜： LOmmと大きくすることで、回転時の遠心力により谷部に集中 する応力が分散され、かつ屈曲による亀裂発生を防止できる。また、該谷部の曲率 半径が大きくなるほど、該谷部を挟む二つの斜面はブーツの軸芯に対する角度が大 きくなり、遠心力の作用方向（ブーツの軸芯と直交する方向）と該傾斜面との角度が 小さくなり、回転時の遠心力により蛇腹部が膨張しにくくなり、ブーツの耐久性が向上 する。 [0033] In addition, in the valley portion of the bellows portion of the boot made of greaves, the largest centrifugal force acts by rotation because the valley portion is closest to the large-diameter mounting portion and the valley portion has the largest inner diameter. Therefore, by increasing the curvature radius of the trough to 2 to LOmm, the stress concentrated on the trough is dispersed by the centrifugal force during rotation, and cracking due to bending can be prevented. Also, the curvature of the valley As the radius increases, the angle between the two slopes sandwiching the valley increases with respect to the boot axis, and the angle between the direction of centrifugal force acting (direction perpendicular to the boot axis) and the inclined surface decreases. The bellows part is less likely to expand due to the centrifugal force during rotation, improving the durability of the boot.
[0034] 更に、前記大径取付部に最も近い山部の外径を、蛇腹部における大径取付部側 の開口径 Dより小さくすると、蛇腹部における各山部の外径力 、さぐ各山部に作用  [0034] Furthermore, if the outer diameter of the peak portion closest to the large-diameter mounting portion is smaller than the opening diameter D on the large-diameter mounting portion side in the bellows portion, the outer diameter force of each peak portion in the bellows portion, Acting on the part
2  2
する遠心力もそのぶん小さくなる。その結果、回転時にブーツが膨張しにくぐ耐久 性にも優れる。  The centrifugal force to be reduced is also much smaller. As a result, the boots are also resistant to swelling during rotation.
[0035] 本発明の第 2の榭脂製ブーツは、前記のような蛇腹部の谷部や山部の内径が小さ く回転時に膨張しにくいので、蛇腹部の肉厚を 3mm以下と薄くしても、等速ジョイント ブーツとして要求される耐久性を満足できる。また、このように蛇腹部の肉厚を薄くす ると、軽量で柔軟性に優れ、また成形に使用する熱可塑性エラストマー榭脂の使用 量も少なくてすみ製造コストも低減できる。  [0035] Since the second bellows boot of the present invention has a small inner diameter at the bellows or peak of the bellows portion and is difficult to expand during rotation, the thickness of the bellows portion is reduced to 3 mm or less. However, the durability required as a constant velocity joint boot can be satisfied. Further, if the thickness of the bellows portion is reduced in this way, it is lightweight and excellent in flexibility, and the amount of thermoplastic elastomer resin used for molding is small, and the manufacturing cost can be reduced.
[0036] 更に、図 10に示す榭脂製ブーツ 1において、蛇腹部 4の大径取付部 3側の開口縁 から外側に山部 6dを突出形成すると、山部 6dの直径が大きくなつて回転時の角速 度が大きく遠心力により膨張しやすくなる。しかし、反対に大径取付部 3側の開口縁 力 内側に向かって谷部を形成すると、蛇腹部 4における大径取付部 3側の内径が 小さくなりすぎて、ジョイントの屈曲時にシャフトが蛇腹部 4の内面に触れやすくなる。 そこで、図 12に示すように、蛇腹部 4における大径取付部 3側の開口縁に、軸芯 Xに 平行にのびる円筒状の周壁部 8を形成すると、回転時の遠心力による蛇腹部 4の膨 張を抑制でき、また前記のように大径取付部 3に最も近い谷部 5cの内径 dを小さくし  [0036] Further, in the resin boot 1 shown in FIG. 10, when the peak portion 6d is formed so as to protrude outward from the opening edge of the bellows portion 4 on the large diameter attachment portion 3 side, the diameter of the peak portion 6d increases and rotates. The angular velocity at the time is large, and it tends to expand due to centrifugal force. On the other hand, if the trough is formed toward the inside of the opening edge force on the large-diameter mounting part 3 side, the inner diameter of the large-diameter mounting part 3 side in the bellows part 4 becomes too small, and the shaft becomes bellows part when the joint is bent. It becomes easy to touch the inner surface of 4. Therefore, as shown in FIG. 12, when the cylindrical peripheral wall portion 8 extending parallel to the axis X is formed at the opening edge of the bellows portion 4 on the large diameter attachment portion 3 side, the bellows portion 4 due to the centrifugal force during rotation is formed. Expansion as well as reducing the inner diameter d of the valley portion 5c closest to the large-diameter mounting portion 3 as described above.
3 ても、蛇腹部 4の内面がジョイントの屈曲時に触れるのを防止でき、かつ大径取付部 3に最も近い谷部 5cの内径を小さくして、回転時の蛇腹部 4の膨張を抑制できる。  However, the inner surface of the bellows portion 4 can be prevented from touching when the joint is bent, and the inner diameter of the valley portion 5c closest to the large-diameter mounting portion 3 can be reduced to suppress the expansion of the bellows portion 4 during rotation. .
[0037] 本発明の射出成型法及び榭脂製ブーツに使用する熱可塑性エラストマー榭脂が、 アクリル系ブロック共重合体 (A)を含む熱可塑性エラストマ一組成物である場合、特 に、アクリル系ブロック共重合体 (A)と、ォレフィン系熱可塑性エラストマ一（B)を含 む熱可塑性エラストマ一組成物である場合には、柔軟性および耐久性に優れ、等速 ジョイント用ブーツなどに最適な榭脂製ブーツなどの成形品を得られる。 [0038] 前記熱可塑性エラストマ一組成物力 アクリル系ブロック共重合体 (A) 100重量部 に対し、ォレフィン系熱可塑性エラストマ一（B) 50〜600重量部および相溶化剤 (C) 5〜50重量部を含んで ヽると、より柔軟性および耐久性に優れた成形品を得られる。 更に、前記アクリル系ブロック共重合体 (A) 1S アクリル系重合体ブロック（a)を 50〜 90重量％含有し、メタアクリル系重合体ブロック (b)を 50〜： L0重量％含有すると、柔 軟性および耐久性が更に優れた成形品を得られる。 [0037] When the thermoplastic elastomer resin used in the injection molding method and resin boot of the present invention is a thermoplastic elastomer composition containing the acrylic block copolymer (A), the acrylic elastomer A thermoplastic elastomer composition containing a block copolymer (A) and an olefin-based thermoplastic elastomer (B) is excellent in flexibility and durability, and is ideal for constant velocity joint boots, etc. Molded products such as rosin boots can be obtained. [0038] The composition strength of the thermoplastic elastomer The acrylic block copolymer (A) is 100 parts by weight, and the olefin-based thermoplastic elastomer (B) is 50 to 600 parts by weight and the compatibilizer (C) is 5 to 50 parts by weight. By including the part, it is possible to obtain a molded article having more flexibility and durability. Furthermore, when the acrylic block copolymer (A) 1S acrylic polymer block (a) is contained in an amount of 50 to 90% by weight and the methacrylic polymer block (b) is contained in an amount of 50 to L0% by weight, A molded product having further excellent softness and durability can be obtained.
[0039] また、前記アクリル系重合体ブロック（a)およびメタアクリル系重合体ブロック (b)の 少なくとも一方の重合体ブロックに反応性官能基 (c)を有すると、耐熱性に優れた成 形品を得られる。  [0039] Further, when at least one polymer block of the acrylic polymer block (a) and the methacrylic polymer block (b) has a reactive functional group (c), the molded product has excellent heat resistance. Goods can be obtained.
[0040] 前記ォレフィン系熱可塑性エラストマ一（B)がォレフイン榭脂中で EPDMゴムまた はアクリロニトリル ·ブタジエンゴムを動的に架橋したものであると、熱可塑性を有しな がらゴム特性として優れた圧縮永久歪、また低温 z高温での弾性変化が小さ ヽ成形 品を得られる。  [0040] When the olefin-based thermoplastic elastomer (B) is obtained by dynamically crosslinking EPDM rubber or acrylonitrile-butadiene rubber in olefin resin, it has excellent rubber properties while having thermoplasticity. Compressed permanent set, low temperature z high elastic change at high temperature ヽ Molded product can be obtained.
[0041] 更に、前記相溶化剤 (C)が、エポキシ基を含有するォレフイン系熱可塑性榭脂であ ると、ォレフィン系熱可塑性榭脂のエポキシ基がアクリル系ブロック共重合体 (A)の ポリメタアクリル酸無水物などの単位 (c)と反応することでアクリル系ブロック共重合体 (A)とォレフイン系熱可塑性エラストマ一（B)をより良好に相溶ィ匕できるので好ま ヽ  [0041] Further, when the compatibilizing agent (C) is an epoxy-based thermoplastic resin containing an epoxy group, the epoxy group of the polyolefin-based thermoplastic resin is an acrylic block copolymer (A). It is preferable because it reacts with units (c) such as polymethacrylic anhydride to better mix the acrylic block copolymer (A) and the olefin thermoplastic elastomer (B).
図面の簡単な説明 Brief Description of Drawings
[0042] [図 1]射出成形金型の断面図である。 FIG. 1 is a cross-sectional view of an injection mold.
[図 2]キヤビティ金型の一方の分割型の分割面の正面図である。  FIG. 2 is a front view of a split surface of one split mold of the cavity mold.
[図 3]キヤビティ金型の他方の分割型の分割面の正面図である。  FIG. 3 is a front view of the split surface of the other split mold of the cavity mold.
[図 4]コア金型の外型の断面図である。  FIG. 4 is a cross-sectional view of an outer mold of a core mold.
[図 5]榭脂を射出した状態の金型の断面図である。  FIG. 5 is a cross-sectional view of a mold in a state in which the resin is injected.
[図 6]榭脂を射出した状態の金型の異なる角度の断面図である。  FIG. 6 is a cross-sectional view at a different angle of the mold in a state where the resin is injected.
[図 7]ドーム状ゲートにおける榭脂の流れを説明する拡大断面図である。  FIG. 7 is an enlarged cross-sectional view for explaining the flow of grease in the dome-shaped gate.
[図 8]成形後、金型を開いた状態の断面図である。  FIG. 8 is a cross-sectional view showing a state where the mold is opened after molding.
[図 9]成形品を高圧空気によりコア金型から取り出す様子を示す断面図である。 [図 10]実施例 1の榭脂製ブーツの断面図である。 FIG. 9 is a cross-sectional view showing how a molded product is taken out from the core mold with high-pressure air. FIG. 10 is a cross-sectional view of a greave boot of Example 1.
[図 11]実施例 2の榭脂製ブーツの断面図である。 FIG. 11 is a cross-sectional view of a resin-made boot of Example 2.
[図 12] (a)は本発明の第 2の榭脂製ブーツの実施の形態 (実施例 3)に係る等速ジョ イント用ブーツの縦断面図であり、（b)および (c)は最も大径取付部に近い谷部の拡 大断面図である。  [FIG. 12] (a) is a longitudinal sectional view of a constant velocity joint boot according to an embodiment (Example 3) of the second resinous boot of the present invention, and (b) and (c) are FIG. 5 is an enlarged cross-sectional view of a trough that is closest to the largest-diameter mounting portion.
[図 13]図 12に示す榭脂製ブーツの底面図である。  FIG. 13 is a bottom view of the resin-made boot shown in FIG.
[図 14]実施例 3の榭脂製ブーツを成形する射出成形金型の断面図である。  FIG. 14 is a cross-sectional view of an injection mold for molding a resin-made boot of Example 3.
[図 15]従来の射出成形方法および射出成形金型を示し、（a)は成形前、（b)は成形 後に脱型する様子を示す断面図である。  FIG. 15 shows a conventional injection molding method and an injection mold, where (a) is a cross-sectional view showing a state before molding, and (b) is a state of demolding after molding.
[図 16]従来の射出成形方法および射出成形金型を示し、（a)、 （b)は榭脂の流れを 示す注入ゲート部分の拡大断面図、（b)は成形品を高圧空気による脱型時の様子を 示す拡大断面図である。  FIG. 16 shows a conventional injection molding method and injection mold, wherein (a) and (b) are enlarged cross-sectional views of the injection gate portion showing the flow of grease, and (b) is the removal of the molded product by high-pressure air. It is an enlarged sectional view showing a state at the time of molding.
符号の説明 Explanation of symbols
1 榭脂製ブーツ (等速ジョイント用ブーツ）  1 Resin boots (Constant velocity joint boots)
2 小径取付部  2 Small diameter mounting part
3 大径取付部  3 Large diameter mounting part
4 蛇腹部  4 Bellows
5 谷部  5 Valley
6 山部  6 Yamabe
10 キヤビティ金型  10 cavity mold
10 A 10B 分割型  10 A 10B Split type
20 コア金型  20 core mold
20A 外型  20A external
20B 中型  20B Medium size
20C 基板  20C board
21 吹出口  21 Air outlet
22 開閉軸  22 Open / close axis
23 ドーム状凸部 24 通気孔 23 Domed convex 24 Vent
30 成形空間  30 Molding space
30A、 30B 成形凹部  30A, 30B molding recess
31A、31B ゲート用凹部  31A, 31B Gate recess
40 ゲート  40 gate
41 注入口  41 Inlet
41A、 41B 溝  41A, 41B groove
42 榭脂注入路  42 Oil injection path
42A、 42B 溝  42A, 42B groove
L 切除部位  L Resection site
M 榭脂  M
P 成形品  P Molded product
発明を実施するための最良の形態  BEST MODE FOR CARRYING OUT THE INVENTION
[0044] 本発明の実施の形態を実施例に基づき図面を参照して詳述するが、本発明はこれ ら実施例に限定されない。 Embodiments of the present invention will be described in detail with reference to the drawings based on examples, but the present invention is not limited to these examples.
[0045] 本発明に係る射出成形方法および射出成形金型は、例えば等速ジョイント用ブー ッのような、蛇腹部を有する榭脂製ブーツなどを、熱可塑性エラストマ一榭脂を射出 成形して製造するときに用いられる。 [0045] An injection molding method and an injection mold according to the present invention include, for example, a resin-made boot having a bellows portion, such as a constant-velocity joint boot, and an injection molding of thermoplastic elastomer. Used when manufacturing.
[0046] 本発明の射出成形金型は、例えば、図 1に示すように、開閉可能に 2分割された、 分割型 10A、 10Bカゝらなるキヤビティ金型 10と、キヤビティ金型 10の一対の分割型 1 OA、 10Bに挟まれた状態に配置されるコア金型 20とからなる。キヤビティ金型 10とコ ァ金型 20の間に形成される筒状の成形空間 30内に、熱可塑性エラストマー榭脂が 射出、充填され、ジョイント用ブーツなどの筒状の中空成形品が成形される。キヤビテ ィ金型 10の分割型 10Aと 10Bは、それらの背面側に位置するベース板（図示省略） に固定され、ベース板とともに左右に移動することで開閉自在に設けられている。コ ァ型 20は、その上側に位置するベース板（図示省略）に固定されている。 [0046] The injection mold of the present invention is, for example, as shown in FIG. 1, a pair of a mold 10A and a mold 10 which are divided into two such that they can be opened and closed, and a mold 10 of the mold. The split mold 1 OA and the core mold 20 arranged in a state sandwiched between 10B. A thermoplastic elastomer resin is injected and filled into a cylindrical molding space 30 formed between the cavity mold 10 and the core mold 20, and a cylindrical hollow molded product such as a joint boot is molded. The The split molds 10A and 10B of the cavity mold 10 are fixed to a base plate (not shown) located on the back side thereof, and can be opened and closed by moving left and right together with the base plate. The core mold 20 is fixed to a base plate (not shown) located on the upper side thereof.
[0047] この射出成形金型は、例えば、図 10に示す、アウターケースに取り付けられる環状 の大径取付部 3と、シャフトに取り付けられる環状の小径取付部 2と、両者を一体に連 結する蛇腹部 4とを備える、等速ジョイント用ブーツなどの榭脂製ブーツ 1の射出成形 に用いられる。キヤビティ金型 10を構成する一対の分割型 10A、 10Bは、図 2、図 3 に示すように、ほぼ左右対称の形状で、相対向する分割面 11A、 11Bに、成形され るブーツ 1の形状に応じて、成形空間 30の外周面を構成する成形凹部 30A、 30Bが 形成されている。凹部 30A、 30Bは、ブーツ 1の小径取付部 2が分割面 11A、 11Bの 下方に位置し、上方に向かって蛇腹状に拡がった形状に形成されている。また、各 凹部 30A、 30Bの下部には、ブーツ 1の小径取付部 2の開口端から、ドーム状の蓋と なる部分を形成するため、約 1Z4球状のゲート用凹部 31A、 3 IBが形成されており 、分割型 10A、 10Bを閉じた合わせると、ゲート用凹部 31A、 31Bにより半球状のド ーム状ゲート 40の外周面が構成される。各ゲート用凹部 31A、 31Bの下端中央部か ら下方へ、成形空間 30 (成形凹部 30A、 30B)内で成形されるブーツ 1の軸芯（図 10 に示す X)と同じ方向にのびる榭脂注入口 41を形成する溝 41A、 41Bが設けられて いる。溝 41A、 41Bの下端部は、ノズル装着部（分割型 10Bにおける符号 43)に連 通する榭脂注入路 42を形成する溝 42A、 42Bに連通している。ノズル装着部には、 射出成形機の榭脂注入ノズル (図示省略)が装着される。榭脂注入用のドーム状ゲ ート 40は、成形後のブーツ形状の歪性を小さくさせるため、小径取付部 2側に設けて ある。 [0047] This injection mold includes, for example, an annular large-diameter attachment portion 3 attached to an outer case and an annular small-diameter attachment portion 2 attached to a shaft as shown in FIG. It is used for injection molding of a greave boot 1 such as a constant velocity joint boot having a bellows portion 4 to be tied. As shown in Figs. 2 and 3, the pair of split molds 10A and 10B that make up the cavity mold 10 have a substantially symmetrical shape, and the shape of the boot 1 molded on the opposing split surfaces 11A and 11B. Accordingly, molding recesses 30A and 30B constituting the outer peripheral surface of the molding space 30 are formed. The recesses 30A and 30B are formed in a shape in which the small-diameter mounting portion 2 of the boot 1 is positioned below the dividing surfaces 11A and 11B and expands upward in a bellows shape. In addition, in order to form a dome-shaped lid from the open end of the small-diameter mounting portion 2 of the boot 1, an approximately 1Z4 spherical gate recess 31A, 3 IB is formed below each recess 30A, 30B. Therefore, when the split molds 10A and 10B are closed together, the outer peripheral surface of the hemispherical dome-shaped gate 40 is constituted by the gate recesses 31A and 31B. Grease extending in the same direction as the shaft core (X shown in Fig. 10) of the boot 1 molded in the molding space 30 (molding recesses 30A, 30B) downward from the lower end center of each gate recess 31A, 31B Grooves 41A and 41B that form the inlet 41 are provided. The lower ends of the grooves 41A and 41B are in communication with the grooves 42A and 42B that form the resin injection passage 42 that communicates with the nozzle mounting portion (reference numeral 43 in the split mold 10B). The nozzle mounting portion is mounted with a resin injection nozzle (not shown) of an injection molding machine. The dome-shaped gate 40 for injecting the resin is provided on the small diameter mounting portion 2 side in order to reduce the distortion of the boot shape after molding.
コア金型 20は、ブーツ 1の内面形状に応じて成形空間 30の内周面を形成する中 空の外型 20Aと、外型 20A内に嵌合される、下向きのほぼ円錐台形の中型 20Bとが 基板 20C下面にボルト（図示省略)などで固定されている。図 1、図 4に示すように、 外型 20Aの下端部には、ドーム状ゲート 40の内周面を形成するドーム状凸部 23が 形成されている。ドーム状凸部 23の中央部先端から、コア金型 20の外型 20A、 20B および基板 20Cを貫通するように通気孔 24が形成されている。通気孔 24の下端開 口部はドーム状ゲート 40に開口し、成形された中空成形品の内側に向かって空気を 噴出する吹出口 21となっている。通気孔 24内には、ソレノイド（図示省略)などにより 瞬間的にスライド可能な開閉軸 22が設けられている。開閉軸 22は、注入口 41から射 出される溶融した熱可塑性榭脂が通気孔 24内に入らないように、熱可塑性榭脂の射 出時には吹出口 21を閉じる。また、成形品の取り出し時には、キヤビティ金型 10の一 対の分割型 10A、 10Bが開くと同時に、開閉軸 22が通気孔 24内をスライドして上昇 (後退)し、エアコンプレッサー（図示省略)など力も供給される高圧空気が通気孔 24 内を通って吹出口 21から成形品の内面に向けて吹き付けられ、コア金型 20から成 形品が押し出される。 The core mold 20 includes a hollow outer mold 20A that forms the inner peripheral surface of the molding space 30 according to the inner surface shape of the boot 1, and a downward-facing substantially frustoconical middle mold 20B that is fitted into the outer mold 20A. Are fixed to the lower surface of the substrate 20C with bolts (not shown). As shown in FIGS. 1 and 4, a dome-shaped convex portion 23 that forms the inner peripheral surface of the dome-shaped gate 40 is formed at the lower end portion of the outer mold 20A. A vent hole 24 is formed so as to penetrate the outer molds 20A and 20B of the core mold 20 and the substrate 20C from the center end of the dome-shaped convex part 23. The lower end opening portion of the vent hole 24 opens to the dome-shaped gate 40, and serves as a blowout port 21 that blows out air toward the inside of the molded hollow molded product. An opening / closing shaft 22 that can be instantaneously slid by a solenoid (not shown) or the like is provided in the vent hole 24. The opening / closing shaft 22 closes the outlet 21 when the thermoplastic resin is sprayed so that the molten thermoplastic resin sprayed from the inlet 41 does not enter the vent hole 24. Also, when removing the molded product, one of the cavity molds 10 Simultaneously with the opening of the pair of split molds 10A and 10B, the open / close shaft 22 slides up (retreats) in the air vent 24, and high-pressure air supplied with force such as an air compressor (not shown) passes through the air vent 24. Then, the air is blown from the outlet 21 toward the inner surface of the molded product, and the molded product is extruded from the core mold 20.
[0049] ドーム状ゲート 40の形状は限定されず、射出される榭脂の流れに乱れが発生せず 、また吹出口 21から成形品の内部、具体的には、ドーム状ゲート 40部分に成形され る、成形品の蓋となる部分の内面に向けて吹き付けられる高圧空気が成形品内面に 均一に作用する形状であればよい。しかし、図 7に示すように、ドーム状ゲート 40を略 半球状とし、その頂点部分に設けた注入孔 41から、溶融した熱可塑性榭脂 Mを射出 すると、榭脂 Mの流れ (図 7中、一点鎖線の矢印で示す。）に乱流ほ Lれ)が発生する ことを効果的に抑えることができ、榭脂の流れムラやウエルドラインなどが発生せず、 外観および機械的特性に優れた成形品を得られる。  [0049] The shape of the dome-shaped gate 40 is not limited, and there is no turbulence in the flow of injected resin. Further, the dome-shaped gate 40 is molded from the outlet 21 into the molded product, specifically, the dome-shaped gate 40. Any shape may be used as long as the high-pressure air blown toward the inner surface of the portion to be the lid of the molded product acts uniformly on the inner surface of the molded product. However, as shown in FIG. 7, when the dome-shaped gate 40 has a substantially hemispherical shape and the molten thermoplastic resin M is injected from the injection hole 41 provided at the apex thereof, the flow of the resin M (in FIG. 7) Indicated by a dashed-dotted arrow)), it is possible to effectively suppress the occurrence of turbulent flow), and there is no uneven flow or weld line of the resin, and excellent appearance and mechanical properties. Can be obtained.
[0050] 更に、ドーム状ゲート 40における成形空間 30への開口端縁 40aを、成形空間 30 内で成形されるブーツ 1の軸芯（図 10に示す X)と平行な方向にのびる、ほぼ円筒状 に形成し、溶融した熱可塑性榭脂を、ドーム状ゲート 40から成形空間 30内で成形さ れるブーツの軸芯 Xと平行に成形空間 30内へ射出、充填すると、ドーム状ゲート 40 力も直線的に成形空間 30内へ樹脂が射出されるので、榭脂の流れに発生する乱流 ほしれ)を更に効果的に抑えられる。  [0050] Further, the opening edge 40a to the molding space 30 in the dome-shaped gate 40 extends substantially in a cylinder extending in a direction parallel to the axial center (X shown in FIG. 10) of the boot 1 molded in the molding space 30. When the thermoplastic resin formed and melted in the shape is injected and filled into the molding space 30 parallel to the axis X of the boot formed in the molding space 30 from the dome-shaped gate 40, the force of the dome-shaped gate 40 is also linear. Therefore, since the resin is injected into the molding space 30, the turbulent flow generated in the flow of the resin can be more effectively suppressed.
[0051] また、図 8、図 9に示すように、コア金型 20の軸芯部分に、その軸方向に貫通し、コ ンプレッサーなどの高圧空気供給手段に連結される通気孔 24を設け、通気孔 24の 先端部をドーム状ゲート 40に開口する吹出口 21とし、通気孔 24内に、先端 22aをド ーム状ゲート 40に臨ませて、コア金型 20の軸方向と同じ方向に摺動する開閉軸 22 を設け、開閉軸 22により吹出口 21を開閉可能とすれば、成形空間 30内への溶融し た熱可塑性榭脂の射出時に、吹出口 21から通気孔 24内へ樹脂が侵入することを確 実に防止できる。また、成形後にコア金型 20からブーツ成形品 Pを取り出すときには 、キヤビティ金型 10の開放と同時に、成形されたブーツ成形品 P内部に高圧空気を 吹き付けて、成形されたブーツ 1をコア金型 20から速やかに取り出すことができ、生 産性良く榭脂製ブーツ 1を成形できる。 [0052] 更に、図 4に示すように、コア金型 20の通気孔 24の先端に近 、部分 24aの径を小 さくするとともに、この径の小さい部分 24aの内周面に、通気孔 24の長さ方向に伸び る単数または複数の通気溝、図例のものでは、 4条の通気溝 25を設け、図 8に示すよ うに、開閉軸 22を、その先端 22aが通気溝 25を設けた位置にくるまで後退させて吹 出口 21を開口し、高圧空気を、通気孔 24から通気溝 25および吹出口 21を通して、 成形されたブーツ成形品 Pの内部に吹き付けるようにすると、成形空間 30内への溶 融した熱可塑性榭脂の射出時における吹出口 21内への榭脂の侵入を確実に防止 できる。 [0051] Further, as shown in FIGS. 8 and 9, a vent hole 24 penetrating in the axial direction and connected to a high-pressure air supply means such as a compressor is provided in the shaft core portion of the core mold 20. The tip of the vent hole 24 is used as the air outlet 21 that opens to the dome-shaped gate 40, and the tip 22a faces the dome-shaped gate 40 in the vent hole 24 so that the axial direction of the core mold 20 is the same. If the opening / closing shaft 22 that slides on the opening / closing shaft 22 and the opening / closing port 22 can be opened / closed by the opening / closing shaft 22, when the molten thermoplastic resin is injected into the molding space 30, the blowing port 21 enters the vent hole 24. The resin can be surely prevented from entering. In addition, when the boot molded product P is taken out from the core mold 20 after molding, the cavity mold 10 is opened, and at the same time, high-pressure air is blown into the molded boot molded product P so that the molded boot 1 is removed from the core mold. It can be quickly removed from 20 and can be made into a resinous boot 1 with good productivity. Further, as shown in FIG. 4, the diameter of the portion 24a is reduced near the tip of the vent hole 24 of the core mold 20, and the vent hole 24 is formed on the inner peripheral surface of the small diameter portion 24a. One or a plurality of ventilation grooves extending in the length direction, and in the example shown in the figure, four ventilation grooves 25 are provided, and as shown in FIG. 8, the opening / closing shaft 22 is provided, and the tip 22a is provided with a ventilation groove 25. The air outlet 21 is opened until it reaches the position, and high-pressure air is blown from the air vent 24 through the air groove 25 and the air outlet 21 to the inside of the molded boot molded product P. It is possible to reliably prevent the intrusion of the resin into the outlet 21 during the injection of the molten thermoplastic resin into the inside.
[0053] 上記のような射出成形金型を用いて、中空成形品、例えば等速ジョイント用ブーツ などの榭脂製ブーツを熱可塑性エラストマ一などの熱可塑性榭脂から射出成形する 手順を以下に説明する。先ず、図 1に示すように、キヤビティ金型 10の分割型 10A、 10Bを閉じ合わせ、キヤビティ金型 10内にコア金型 20を配置し、キヤビティ金型 10と コア金型 20との間に所定のブーツ形状に応じた成形空間 30を形成する。次いで、ノ ズル装着部 43に連結した射出成形機（図示省略)から、図 5、図 6に示すように、榭 脂注入路 42、注入口 41、ドーム状ゲート 40、更に成形空間 30内へと、溶融した熱 可塑性榭脂を射出、充填し、ドーム状ゲート 40部分に成形される蓋となる部分 (図 9 に符合 cで示す）により、一端が閉止された中空成形品、例えば榭脂製ブーツを成形 する。  [0053] A procedure for injection molding hollow resin articles, for example, resin-made boots such as constant-velocity joint boots, from thermoplastic resin such as a thermoplastic elastomer, using the injection mold as described above, is as follows. explain. First, as shown in FIG. 1, the split molds 10A and 10B of the cavity mold 10 are closed, and the core mold 20 is disposed in the cavity mold 10, and the cavity mold 10 and the core mold 20 are placed between them. A molding space 30 corresponding to a predetermined boot shape is formed. Next, from the injection molding machine (not shown) connected to the nozzle mounting part 43, as shown in FIGS. 5 and 6, the resin injection path 42, the injection port 41, the dome-shaped gate 40, and further into the molding space 30 are obtained. Then, a molten thermoplastic resin is injected and filled, and a hollow molded product whose one end is closed by a portion (indicated by symbol c in FIG. 9) that is a lid formed on the dome-shaped gate 40, for example, Mold boots.
[0054] 成型後、分割型 10A、 10Bを左右に開く（図 8)と同時にコア金型 20に外嵌されて いる成形品 Pの蓋となる部分 cの内面に対して高圧空気を吹き付ける。これにより、コ ァ金型 20に密着している成形品 Pの内面に、高圧空気により均一に圧力が作用し、 成形品 Pが瞬間的に膨張してコア金型 20外周面と成形品 P内周面との間に隙間が 形成されると同時に、コア金型 20から下方へ成形品 Pが押し出される（図 9)。  [0054] After molding, the split molds 10A and 10B are opened to the left and right (Fig. 8), and at the same time, high-pressure air is blown against the inner surface of the portion c serving as the lid of the molded product P that is externally fitted to the core mold 20. As a result, pressure is uniformly applied to the inner surface of the molded product P that is in close contact with the core mold 20 by the high-pressure air, and the molded product P expands instantaneously and the outer peripheral surface of the core mold 20 and the molded product P A gap is formed between the inner peripheral surface and the molded product P is pushed downward from the core mold 20 (FIG. 9).
[0055] 取り出された成形品 Pは、成形時に蓋となった部分 cから先のランナー部分ゃスプ ルー部分などの余分な榭脂部分が、図 9中に、符合 Lで示す部位から切除され、図 1 0に示すような榭脂製ブーツ 1などの製品となる。  [0055] In the molded product P that has been taken out, excess grease parts such as the runner part and sprue part from the part c that became the lid at the time of molding are cut off from the part indicated by the symbol L in FIG. This is a product such as boot 1 made of resin as shown in FIG.
[0056] 図 10、図 11は、本発明の実施形態に係る榭脂製ブーツ 1、 1Aの縦断面図である。  FIG. 10 and FIG. 11 are longitudinal sectional views of the resinous resin boots 1 and 1A according to the embodiment of the present invention.
このブーツ 1、 1Aは、自動車のシャフトに取り付けられる小径取付部 2と、例えばトリポ ートタイプの等速ジョイントのような 3個の凹部がある非円形な外周形状のアウターケ ースに取り付けられる大径取付部 3と、小径取付部 2と大径取付部 3を一体に連結す る蛇腹部 4とを備える等速ジョイント用ブーツである。また、図 12 (a)は、本発明の第 2 の榭脂製ブーツの実施形態に係る榭脂製ブーツ 1Bの縦断面図である。このブーツ 1 Bは、ブーツ 1、 1Aと同様に、自動車の等速ジョイント用ブーツである。これらの榭脂 製ブーツ 1は、全体にほぼ円錐台形状をしている力 例えば、二輪車のシャフトブー ッのように、両端の取付部 2、 3が同径の円筒形状のブーツであってもよい。また、蛇 腹部 4は、独立した複数の凸条部と凹条部とが交互に形成されたものでもよいし、各 一条の凸条部と凹条部とが螺旋状に形成されたものでもよい。更に、両端の取付部 2 、 3や蛇腹部 4の平面形状 (横断面形状)は円形でなぐ角形、楕円形などでもよぐ ブーツ 1の全体形状に特に限定はない。また、大径取付部 4は、図 13に示すように、 例えばトリポートタイプの等速ジョイントのような 3個の凹部がある非円形な外周形状 のアウターケースに取り付けられるよう、その内周面に複数の凸部 7が形成された非 円形状でもよい。 These boots 1 and 1A are connected to a small-diameter mounting portion 2 that is attached to the shaft of an automobile, for example, a tripod A large-diameter mounting part 3 that can be attached to a non-circular outer shape outer case with three recesses, such as a constant-velocity joint, and a bellows that integrally connects the small-diameter mounting part 2 and the large-diameter mounting part 3 4 is a constant velocity joint boot provided with part 4. FIG. 12 (a) is a longitudinal cross-sectional view of a resinous boot 1B according to an embodiment of the second resinous boot of the present invention. The boot 1 B is a boot for a constant velocity joint of an automobile, like the boots 1 and 1A. These resin boots 1 have a generally frustoconical shape, for example, even if the mounting parts 2 and 3 at both ends are cylindrical boots having the same diameter, such as a shaft boot of a motorcycle. Good. Further, the bellows portion 4 may be formed by alternately forming a plurality of independent ridges and recesses, or may be formed by spirally forming each one of the ridges and recesses. Good. Further, the planar shape (transverse cross-sectional shape) of the attachment portions 2 and 3 and the bellows portion 4 at both ends may be a square shape or an elliptical shape. There is no particular limitation on the overall shape of the boot 1. Further, as shown in FIG. 13, the large-diameter mounting portion 4 has an inner peripheral surface so that it can be attached to a non-circular outer peripheral case having three concave portions such as a triport type constant velocity joint. A non-circular shape in which a plurality of convex portions 7 are formed may be used.
[0057] 図例の榭脂製ブーツ 1、 1A、 IBは、蛇腹部 4に 5a〜5cの 3個の谷部と 6a〜6cの 3 個の山部が形成されている。蛇腹部 4の谷部 5や山部 6の数は、特に限定はないが、 射出成形の加工性や、回転時の蛇腹部 4の膨張性などの点では、山部 6の数は 3〜 5個が好ましい。蛇腹部 4の山部 6の数が 3個より少ないと、山部 4と谷部 5との寸法差 が大きくなり、射出成形後の脱型が困難になることがある。蛇腹部 4の山部 6の数が 5 個より多いと、蛇腹部 4の厚みが薄くなり、回転中に蛇腹部 4が膨張したり、隣りあう山 部 6間のピッチが狭くなる結果、谷部 5の曲率半径 Rが小さくなり、回転中に遠心力に よる応力が集中して亀裂が発生しやすくなる。  In the illustrated boots 1, 1 A, and IB, three bellows 5 a to 5 c and three peaks 6 a to 6 c are formed on the bellows portion 4. The number of valleys 5 and peaks 6 of the bellows part 4 is not particularly limited, but the number of peaks 6 is 3 to 3 in terms of the processability of injection molding and the expandability of the bellows part 4 during rotation. 5 is preferred. If the number of the peak portions 6 of the bellows portion 4 is less than three, the dimensional difference between the peak portions 4 and the valley portions 5 becomes large, and it may be difficult to remove the mold after injection molding. When the number of the peak portions 6 of the bellows portion 4 is more than five, the thickness of the bellows portion 4 becomes thin, and the bellows portion 4 expands during rotation or the pitch between the adjacent peak portions 6 becomes narrow. The radius of curvature R of the part 5 becomes small, and stress due to centrifugal force concentrates during rotation, and cracks tend to occur.
[0058] 上記の榭脂製ブーツ 1、 1A、 IBは、一方の取付部（小径取付部 2)側に設けたゲ ート 40から金型の成形空間 30内へ熱可塑性エラストマ一榭脂を射出、充填して成 形される。ブーツ 1、 1Aの蛇腹部 4の肉厚は、図 10に示すブーツ 1のように均一でも よいが、図 11に示すブーツ 1 Aのように、谷部 5、例えば 5b、 5cのそれぞれの厚みを 、該谷部 5b、 5cに対して、ゲート 40を設けた側に隣り合う山部、即ちゲート 40から成 形空間 30内に射出される榭脂の流れの上流側である、小径取付部 2に近い側に隣 り合う山部 6b、 6cのそれぞれの厚みより厚く形成することが好ましい。この場合、全て の谷部 5a〜5cが、それらに隣り合う山部 6a〜6cに比べて厚肉に形成されている必 要はなぐ例えば図 11のブーツ 1Aのように、一部の谷部 5b、 5cのみが、それに隣り 合う山部 6b、 6cに比べて厚く形成されていてもよい。ただし、ブーツ 1Aの全ての谷 部 5a〜5cは、該谷部 5a〜5cに対して、榭脂の流れの上流側の小径取付部 2寄りに 隣り合うそれぞれの山部 6a〜6cの厚みと同じ力、それより厚く形成する必要がある。 山部 6の肉厚に比べて、該山部 6に対して、榭脂の流れの下流側、即ち、大径取付 部 3側に隣り合う谷部 5の肉厚が薄い場合には、ウエルドライン発生の原因となりやす い。例えば、図 11に示すブーツ 1Aでは、蛇腹部 4には、 4つの山 6a〜6dと 3つの谷 部 5a〜5cが交互に形成されている力 第 1の山部 6aと谷部 5aとは同じ厚みとし、第 2の谷部 5baと第 3および谷部 5cとは、それぞれ第 2の山部 6bおよび第 3の山部 6c の厚みよりも厚く形成されている。同じ厚みに形成される第 1の山部 6aから第 1の谷 部 5aに樹脂が注入される際にはウエルドラインは発生しない。また、第 2および第 3 の谷部 5b、 5cの厚みを、それらに対してゲート 40側に隣り合う第 2および第 3の山部 6b、 6cより厚く形成するので、ゲート 40から成形空間 30内に射出、充填された熱可 塑性エラストマー榭脂 Mは、山部 6bから谷部 6bへ、更に山部 6cから谷部 5cへと、連 続性を失わずに円滑に充填され、ウエルドラインは発生しない。し力も、第 2、第 3の 谷部 5b、 5cを山部 6に比べて肉厚に形成するので、回転時の遠心力による蛇腹部 4 の膨張が防止されるとともに、その一方で、山部 6a〜6dの肉厚を薄くできるので、蛇 腹部 4の柔軟性を損なうこともなぐ耐久性にも優れる。 [0058] The above-mentioned boots 1, 1A, IB made of thermoplastic resin are filled with thermoplastic elastomer into the molding space 30 of the mold from the gate 40 provided on one mounting portion (small-diameter mounting portion 2) side. It is formed by injection and filling. The thickness of the bellows 4 of the boots 1 and 1A may be uniform as in the boot 1 shown in FIG. 10, but the thickness of the valleys 5 such as 5b and 5c as shown in the boot 1 A shown in FIG. A small-diameter mounting portion that is a crest adjacent to the side where the gate 40 is provided with respect to the troughs 5b and 5c, that is, upstream of the flow of the resin injected from the gate 40 into the molding space 30. Next to the side close to 2 It is preferable to form thicker than the thicknesses of the ridges 6b and 6c. In this case, it is not necessary for all the valleys 5a to 5c to be formed thicker than the adjacent peaks 6a to 6c, for example, some valleys like the boot 1A in FIG. Only 5b and 5c may be formed thicker than the adjacent peaks 6b and 6c. However, all the valleys 5a to 5c of the boot 1A have the thicknesses of the respective peaks 6a to 6c adjacent to the valleys 5a to 5c adjacent to the small-diameter attachment part 2 on the upstream side of the flow of grease. It is necessary to form thicker than the same force. When the thickness of the valley 5 adjacent to the downstream side of the flow of the resin, that is, the valley 5 adjacent to the large diameter mounting portion 3 is smaller than the thickness of the peak 6, the weld Prone to line generation. For example, in the boot 1A shown in FIG. 11, the bellows part 4 has a force in which four peaks 6a to 6d and three valleys 5a to 5c are alternately formed. The second valley portion 5ba, the third valley portion 5c, and the second valley portion 5c have the same thickness, and are formed thicker than the second peak portion 6b and the third peak portion 6c, respectively. When the resin is injected from the first peak 6a formed to the same thickness into the first valley 5a, no weld line is generated. In addition, since the second and third troughs 5b and 5c are formed thicker than the second and third crests 6b and 6c adjacent to the gate 40 side with respect to them, the molding space 30 is formed from the gate 40. The thermoplastic elastomer resin M injected and filled inside is smoothly filled from the peak 6b to the valley 6b and further from the peak 6c to the valley 5c without losing continuity. Does not occur. Since the second and third valleys 5b and 5c are formed thicker than the peak 6, the bellows 4 is prevented from expanding due to the centrifugal force during rotation. Since the thickness of the parts 6a to 6d can be reduced, the flexibility of the bellows part 4 is not impaired, and the durability is excellent.
また、ブーツ 1Bでは、最も大径取付部 3に近い谷部 5cの内径 dを、蛇腹部 4にお  In the boot 1B, the inner diameter d of the valley 5c closest to the largest diameter mounting portion 3 is set to the bellows portion 4.
3  Three
ける大径取付部 3側の開口径、即ち、図例のブーツ 1Bでは、蛇腹部 4における小径 取付部 2側の開口径 Dより大きぐかつ大径取付部 3側の開口縁にブーツ 1の軸芯 X In the boot 1B shown in the figure, the opening diameter on the large diameter mounting portion 3 side, that is, the opening diameter D on the bellows portion 4 is larger than the opening diameter D on the small diameter mounting portion 2 side and the opening edge of the boot 1 Shaft core X
1  1
に平行にのびる円筒状に形成した周壁部 8の内径 Dの 60%以下に形成してなる。 It is formed to be 60% or less of the inner diameter D of the peripheral wall portion 8 formed in a cylindrical shape extending in parallel with.
2  2
ブーツ 1Bは、蛇腹部 4が大径取付部 3から小径取付部 2に向力つてその直径、即ち 各谷部 5および山部の直径が順次小さくなるよう形成されている。従って、大径取付 部 3に最も近い谷部 5cの内径 dを小さくするほど、小径取付部 2に向力つてその直径 The boot 1B is formed so that the bellows part 4 is directed from the large diameter attachment part 3 to the small diameter attachment part 2 so that the diameter thereof, that is, the diameter of each valley part 5 and the peak part becomes smaller. Therefore, the smaller the inner diameter d of the valley portion 5c closest to the large-diameter mounting portion 3, the smaller the inner diameter d,
3  Three
が順次小さく形成されている各段の谷部 5b、 5cの内径 d 、 dも必然的に小さくなる。 そして、ブーツ IBでは、大径取付部 3に最も近い谷部 5cの内径 dを、蛇腹部 4にお , The inner diameters d and d of the valleys 5b and 5c of each step, which are successively formed, are inevitably smaller. In the boot IB, the inner diameter d of the valley portion 5c closest to the large-diameter mounting portion 3 is set to the bellows portion 4.
3  Three
ける大径取付部側の縁部の内径 Dの 60%以下と小さくしているので、回転時の各段  Since the inner diameter D of the edge on the large-diameter mounting part side is as small as 60% or less, each step during rotation
2  2
の谷部 5a、 5b、 5cの角速度が小さぐ作用する遠心力もそれだけ小さくなる結果、ブ ーッ 1Bは、回転時に膨張しにくぐ耐久性に優れている。  As a result of the reduced centrifugal force acting at the lower angular velocities of the valleys 5a, 5b, and 5c, the boot 1B is excellent in durability to hardly expand during rotation.
[0060] また、谷部 5cの曲率半径 Rを、図 12 (b)に示す、例えば lmmの小さなものから図 1 2 (c)に示すように 2〜： LOmmと大きくすることで、回転時の遠心力により谷部 5cに集 中する応力が分散され、かつ屈曲による亀裂発生を防止できる。また、谷部 5cの曲 率半径が大きくなるほど、谷部 5cを挟む二つの斜面 4a、 4bの、ブーツ軸芯 Xに対す る角度が大きくなり、遠心力の作用方向と傾斜面 4a、 4bとの角度が小さくなり、回転 時の遠心力により傾斜面 4a、 4bが膨張しに《なって、ブーツ 1Bの耐久性が向上す る。 [0060] Further, the radius of curvature R of the valley 5c is increased from 2 to LOmm as shown in FIG. Due to the centrifugal force, the stress concentrated in the valley 5c is dispersed and cracking due to bending can be prevented. As the curvature radius of the valley 5c increases, the angle of the two inclined surfaces 4a and 4b sandwiching the valley 5c with respect to the boot axis X increases, and the direction of centrifugal force acting and the inclined surfaces 4a and 4b The inclination angle becomes smaller, and the inclined surfaces 4a and 4b expand due to the centrifugal force during rotation, so that the durability of the boot 1B is improved.
[0061] 更に、前記大径取付部に最も近い山部 6cの外径を、蛇腹部 4における大径取付部 側の開口径 Dより小さくすると、蛇腹部 4における各山部 6a  [0061] Further, if the outer diameter of the peak portion 6c closest to the large diameter attachment portion is smaller than the opening diameter D on the large diameter attachment portion side in the bellows portion 4, each peak portion 6a in the bellows portion 4 will be described.
2 〜6cの外径が小さぐそ れらに作用する遠心力もそのぶん小さくなり、ブーツ 1Bは更に膨張しにくくなり、耐久 '性に優れたものとなる。  As the outer diameters of 2 to 6c are small, the centrifugal force acting on them is also reduced, so that the boot 1B becomes more difficult to expand and has excellent durability.
[0062] また、図 12に示す如ぐ大径取付部 3側の縁部に、軸芯 Xに平行にのびる円筒状 の周壁部 8を形成し、該周壁部 8の上周縁 6dを基点にしてブーツの内方へ谷部 5cに 向かう傾斜面 4bを形成すると、図 10、図 11に示す、大径取付部 3側の開口縁から外 側へ山部 6dを突設したものに較べて、回転時の遠心力による蛇腹部 4の膨張を抑制 でき、かつ大径取付部 3に最も近い谷部 5cの内径 dを小さくしても、谷部 5cは大径  In addition, a cylindrical peripheral wall portion 8 extending in parallel to the axis X is formed on the edge portion on the large diameter attachment portion 3 side as shown in FIG. 12, and the upper peripheral edge 6d of the peripheral wall portion 8 is used as a base point. By forming the inclined surface 4b toward the valley 5c inward of the boot, compared to the one shown in FIGS. 10 and 11, the projection 6d projecting outward from the opening edge on the large-diameter mounting part 3 side. Even if the inner diameter d of the valley portion 5c closest to the large-diameter mounting portion 3 can be reduced, the valley portion 5c has a large diameter.
3  Three
取付部 3から更に周壁部 8の高さ分だけ離れた位置に形成されるので、ジョイントの 屈曲時に谷部 5の内面がシャフトなどに触れにくくなり、谷部 5cの内径 dを小さくして  Since it is formed at a position further away from the mounting part 3 by the height of the peripheral wall part 8, the inner surface of the valley part 5 becomes difficult to touch the shaft etc. when the joint is bent, and the inner diameter d of the valley part 5c is reduced.
3  Three
回転に作用する遠心力を小さくして、回転時の蛇腹部 4の膨張を抑制できる。  The centrifugal force acting on the rotation can be reduced to suppress the expansion of the bellows part 4 during the rotation.
[0063] 次に、本発明の射出成形方法および榭脂製ブーツの製造に使用される榭脂につ いて説明する。 [0063] Next, the resin used in the production of the injection molding method and the resin boot of the present invention will be described.
使用される榭脂に特に限定されないが、熱可塑性榭脂が好ましぐ更にジョイント用 ブーツなどの榭脂製ブーツを成形する場合には、熱可塑性エラストマ一が好ま 、。 熱可塑性エラストマ一榭脂は特に限定されな 、が、例えば自動車の等速ジョイント用 ブーツの場合には、成形性に加えて、耐熱性、耐油性、圧縮永久歪性に優れ、また 引張永久歪が小さい、アクリル系ブロック共重合体が好ましぐ特に、ォレフィン Zァ クリル複合の熱可塑性エラストマー榭脂が好ましい。また、例えば、熱可塑性ポリウレ タン (TPU)、塩素含有ポリマー、ポリ塩ィ匕ビユリデン (PVDC)、ポリ塩ィ匕ビュル (PV C)、塩素化ポリエチレン (CPE)、フッ素含有ポリマー、ポリ弗化ビ-リデン (PDVF)、 ポリエステル類、アクリロニトリル一ブタジエン一スチレンコポリマー（ABS)、スチレン —アクリロニトリルコポリマー（SAN)、スチレン—無水マレイン酸コポリマー（SMA)、 ポリアセタール類、ポリカーボネート類、ポリフエ-レンォキシドなどの熱可塑性ポリマ 一も使用できる。 The resin used is not particularly limited, but thermoplastic resin is preferred. Furthermore, when molding a resin boot such as a joint boot, a thermoplastic elastomer is preferred. Thermoplastic elastomers are not particularly limited, but for example for automotive constant velocity joints In the case of boots, in addition to moldability, acrylic block copolymers with excellent heat resistance, oil resistance, compression set resistance, and low tensile set are preferred. A thermoplastic elastomer resin is preferred. In addition, for example, thermoplastic polyurethane (TPU), chlorine-containing polymer, polysalt-vinylidene (PVDC), poly-salt-bule (PVC), chlorinated polyethylene (CPE), fluorine-containing polymer, polyvinyl fluoride. -Thermoplastics such as redene (PDVF), polyesters, acrylonitrile-butadiene-styrene copolymer (ABS), styrene-acrylonitrile copolymer (SAN), styrene-maleic anhydride copolymer (SMA), polyacetals, polycarbonates, polyphenol-oxide A polymer can also be used.
[0064] アクリル系ブロック共重合体としては、例えば、特開 2004— 300164号公報、特開 2004— 315803号公報に記載されたものが挙げられる。ォレフィン Zアクリル複合 の熱可塑性エラストマー榭脂としては、（A)アクリル系ブロック共重合体と (B)ォレフィ ン系熱可塑性エラストマ一とを含む熱可塑性エラストマ一組成物が好まし ヽ。更に、 前記 (A)、（B)に加えて、（C)相溶化剤を含む熱可塑性エラストマ一組成物が更に 好ましい。  [0064] Examples of the acrylic block copolymer include those described in JP-A-2004-300164 and JP-A-2004-315803. A thermoplastic elastomer composition comprising (A) an acrylic block copolymer and (B) an polyolefin thermoplastic elastomer is preferred as the thermoplastic elastomer resin of the polyolefin X acrylic composite. Furthermore, a thermoplastic elastomer composition containing (C) a compatibilizing agent in addition to (A) and (B) is more preferred.
[0065] 本発明で熱可塑性エラストマ一として好適に使用されるアクリル系ブロック共重合体  [0065] An acrylic block copolymer suitably used as a thermoplastic elastomer in the present invention
(A)について、更に詳細に説明する。  (A) will be described in more detail.
[0066] アクリル系ブロック共重合体 (A)としては、アクリル系重合体ブロック（a)およびメタ アクリル系重合体ブロック（b)力 なるものが好まし!/、。アクリル系ブロック共重合体（ A)の構造は、線状ブロック共重合体、分岐状 (星状)ブロック共重合体、これらの混 合物のいずれでもよぐ加工特性や機械特性などに応じて使いわければよい。コスト 面や重合容易性の点から、線状ブロック共重合体が好ましい。線状ブロック共重合体 の構造は、その物性の点から、アクリル系重合体ブロック (a)およびメタアクリル系重 合体ブロック (b)が、一般式：（a— b)、一般式: b—（a— b) 、一般式：（a— b) — a (こ れら一般式中の nは 1〜3の整数)で表わされるものが好ましい。これらの中でも、カロ ェ時の取扱い容易性や、組成物にしたときの物性の点から、 a— b型のジブロック共 重合体、 b— a— b型のトリブロック共重合体またはこれらの混合物が好ま 、。  [0066] As the acrylic block copolymer (A), an acrylic polymer block (a) and a methacrylic polymer block (b) are preferred. The structure of the acrylic block copolymer (A) depends on the processing characteristics and mechanical properties of linear block copolymers, branched (star) block copolymers, and mixtures of these. You can use it properly. From the viewpoint of cost and ease of polymerization, a linear block copolymer is preferred. The structure of the linear block copolymer is that the acrylic polymer block (a) and the methacrylic polymer block (b) are represented by the general formula: (a—b) and general formula: b— A compound represented by (a-b), general formula: (a-b) -a (wherein n is an integer of 1 to 3) is preferred. Among these, from the viewpoint of ease of handling at the time of calorie and physical properties when formed into a composition, an a-b type diblock copolymer, a b-a-b type triblock copolymer, or these Prefer the mixture.
[0067] アクリル系ブロック共重合体 (A)には、前記重合体ブロック（a)および (b)の少なくと も一方の重合体ブロックに、反応性官能基 (C)を有することが好ましい。 更に、前記反応性官能基 (c)としては、一般式（1)： [0067] The acrylic block copolymer (A) includes at least the polymer blocks (a) and (b). One of the polymer blocks preferably has a reactive functional group (C). Furthermore, as the reactive functional group (c), the general formula (1):
[化 2]  [Chemical 2]
Figure imgf000027_0001
Figure imgf000027_0001
(式中、 R1は水素原子またはメチル基で、互いに同一でも異なっていてもよい、 pは 0 または 1の整数、 qは 0〜3の整数）、で表わされる酸無水物基を含有する単位 (cl) および Zまたはカルボキシル基を含有する単位 (c2)力 なるものが好ましく、該単位 (c) 1S アクリル系重合体ブロック（a)およびメタアクリル系重合体ブロック (b)の少なく とも一方の重合体ブロックあたりに 1個以上含まれて 、るのがよ 、。単位 (c)の数が 2 個以上の場合には、その単位 (c)が重合されている様式はランダム共重合でもよ、く ブロック共重合でもよ ヽ。 (Wherein R 1 is a hydrogen atom or a methyl group, which may be the same or different from each other, p is an integer of 0 or 1, q is an integer of 0 to 3), A unit (cl) and a unit containing a Z or carboxyl group (c2) are preferred, and at least one of the unit (c) 1S acrylic polymer block (a) and methacrylic polymer block (b) One or more per polymer block should be included. When the number of units (c) is 2 or more, the mode in which the units (c) are polymerized may be random copolymerization or block copolymerization.
[0069] 単位 (c)を含有するブロック共重合体の構造を、 b— a— b型のトリブロック共重合体 を例にして示すと、（bZc)— a— b型、（bZc)— a—（bZc)型、 c b— a— b型、 c b— a— b— c型、 b - (a/c)— b型、 b— a— c b型、 b— c— a— b型などであり、これ らの 、ずれでもよ!/、。ここで（aZc)とは、ブロック（a)に単位（c)が含有されて!、ること を表わし、（bZc)とは、ブロック（b)に単位 (c)が含有されていることを表わし、 c -a ―、 a— c とは、ブロック (a)の端部に単位 (c)が結合していることを表わす。表現上 は、 (a/c) , (bZc)、 c— a—、 a— c などである力 これらはいずれもアクリル系重 合体ブロック（a)またはメタアクリル系重合体ブロック (b)である。 [0069] The structure of a block copolymer containing the unit (c) is shown by taking a b-a-b type triblock copolymer as an example, and (bZc) -a-b type, (bZc)- a— (bZc) type, cb—a—b type, cb—a—b—c type, b— (a / c) —b type, b—a—cb type, b—c—a—b type, etc. And these can be offset! / Here, (aZc) means that unit (c) is contained in block (a) !, and (bZc) means that unit (c) is contained in block (b). C -a-and a- c indicate that the unit (c) is connected to the end of the block (a). In terms of expression, forces such as (a / c), (bZc), c—a—, a—c, etc. These are all acrylic polymer blocks ( a ) or methacrylic polymer blocks (b). .
[0070] アクリル系ブロック共重合体 (A)の数平均分子量は、 30000〜500000力好ましく 、 40000〜400000力より好まし <、 50000〜300000力更に好まし!/、。ァクジノレ系ブ ロック共重合体 (A)の分子量が 30000未満であるとエラストマ一として充分な機械特 性を発現できないことがあり、 500000を超えると加工特性が低下することがある。ァ クリル系ブロック共重合体 (A)の重量平均分子量 (Mw)と数平均分子量 (Mn)の比（ MwZMn)は、 1〜2が好ましぐ 1〜1. 8が更に好ましい。 MwZMnが 2を超えると アクリル系ブロック共重合体 (A)の圧縮永久歪性が悪ィ匕することがある。なお、前記 数平均分子量（Mn)および重量平均分子量（Mw)は、ゲルパーミエーシヨンクロマト グラフィーを用い、クロ口ホルムを移動相とし、ポリスチレン換算の分子量を求めたも のである。 [0070] The number average molecular weight of the acrylic block copolymer (A) is preferably 30000 to 500000, more preferably 40000 to 400000, and more preferably 50000 to 300000! Akujinole If the molecular weight of the lock copolymer (A) is less than 30,000, sufficient mechanical properties as an elastomer may not be exhibited, and if it exceeds 500,000, the processing characteristics may deteriorate. The ratio (MwZMn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the acrylic block copolymer (A) is preferably 1 to 2, and more preferably 1 to 1.8. When MwZMn exceeds 2, the compression set of the acrylic block copolymer (A) may be deteriorated. The number average molecular weight (Mn) and the weight average molecular weight (Mw) are those obtained by gel permeation chromatography and using a black mouth form as a mobile phase to obtain a molecular weight in terms of polystyrene.
[0071] アクリル系ブロック共重合体 (A)を構成するアクリル系重合体ブロック (a)とメタアタリ ル系重合体ブロック (b)との組成比は、要求される物性、組成物の加工時に要求され る成形性、およびアクリル系重合体ブロック (a)とメタアクリル系重合体ブロック (b)に それぞれ必要とされる分子量など力も決めればょ 、。好ま 、アクリル系重合体プロ ック (a)とメタアクリル系重合体ブロック (b)の組成比の範囲を例示すると、アクリル系 重合体ブロック（a)が 50〜90重量％、更には 50〜80重量％、特には 50〜70重量 %、メタアクリル系重合体ブロック（b)が 50〜10重量％、更には 50〜20重量％、特 には 50〜30重量％である。アクリル系重合体ブロック（a)の割合が 50重量％ょり少 ないと、エラストマ一としての機械特性、特に破断伸びが低下したり、柔軟性が低下 することがあり、 90重量0 /0より多いと、高温でのゴム弾性が低下することがある。 [0071] The composition ratio of the acrylic polymer block (a) to the methacrylic polymer block (b) constituting the acrylic block copolymer (A) is required for the physical properties required during processing of the composition. Determine the moldability and the required molecular weight for the acrylic polymer block (a) and the methacrylic polymer block (b). Preferably, when the range of the composition ratio of the acrylic polymer block (a) and the methacrylic polymer block (b) is exemplified, the acrylic polymer block ( a ) is 50 to 90% by weight, more preferably 50 to 50%. It is 80% by weight, in particular 50 to 70% by weight, methacrylic polymer block (b) is 50 to 10% by weight, further 50 to 20% by weight, in particular 50 to 30% by weight. When the ratio of the acrylic polymer block (a) is 50 wt% Yori not small, the mechanical properties of the elastomer and foremost, lowered particularly elongation at break, there is the flexibility is lowered, from 90 weight 0/0 If it is large, rubber elasticity at high temperatures may be lowered.
[0072] アクリル系重合体ブロック（a)とメタアクリル系重合体ブロック (b)とのガラス転移温 度 (Tg)の関係は、アクリル系重合体ブロック (a)のガラス転移温度を Tg、メタアタリ a  [0072] The relationship between the glass transition temperature (Tg) of the acrylic polymer block (a) and the methacrylic polymer block (b) is that the glass transition temperature of the acrylic polymer block (a) is Tg, a
ル系重合体ブロック (b)のガラス転移温度をを Tgとした場合、下式の関係を満たす b  When the glass transition temperature of the polymer block (b) is Tg b
ことが好ましい。  It is preferable.
Tg <Tg  Tg <Tg
a  a
[0073] アクリル系重合体ブロック（a)やメタアクリル系重合体ブロック (b)のガラス転移温度  [0073] Glass transition temperature of acrylic polymer block (a) and methacrylic polymer block (b)
(Tg)は、概略、下記の Foxの式にしたカ^、、各重合体ブロックにおける単量体の重 量比率を用いて求めることができる。  (Tg) can be roughly determined by using the following Fox formula and the monomer weight ratio in each polymer block.
) )
Figure imgf000028_0001
Figure imgf000028_0001
W +W H—— hW = 1 (式中、 Tgは重合体ブロックのガラス転移温度を表わし、 Tg , Tg , · ··, Tgは、それ W + WH—— hW = 1 (Where Tg represents the glass transition temperature of the polymer block, Tg, Tg, ..., Tg
1 2 m ぞれ重合した単量体 (ホモポリマー）のガラス転移温度を表わす。また、 w 1 , w 2 , ···, wは、それぞれ重合した単量体の重量比率を表わす。  1 2 m Indicates the glass transition temperature of each polymerized monomer (homopolymer). In addition, w 1, w 2,..., W each represent a weight ratio of polymerized monomers.
m  m
[0074] 前記 Foxの式における、重合した単量体それぞれのガラス転移温度は、例えば、ポ リマー ノヽンドブック 3版（Polymer Handbook Third Edition) (ウイレイ イン ターサイエンス（Wiley— Interscience) , 1989)に記載されている。  [0074] The glass transition temperature of each polymerized monomer in the Fox formula is described in, for example, Polymer Handbook Third Edition (Wiley-Interscience, 1989). Has been.
[0075] アクリル系重合体ブロック（a)は、その全体中、アクリル酸エステルを含有する単位 を 50〜100重量。 /0、好ましくは 60〜： L00重量％含有し、単位（c)の前駆体となる官 能基を有する単量体を 0〜50重量％、好ましくは 0〜40重量％含有し、且つこれらと 共重合可能な他のビニル系単量体を 0〜 50重量％、更には 0〜 25重量％を含有す るのが好ま 、。前記アクリル酸エステルを含有する単位の割合が 50重量％未満で あると、アクリル酸エステルを用いる場合の特徴である物性、特に引張特性の伸びが /J、さくなることがある。 [0075] The acrylic polymer block (a) contains 50 to 100 weight units of an acrylate ester in the whole. / 0 , preferably 60 to: L00% by weight, 0 to 50% by weight, preferably 0 to 40% by weight of monomers having functional groups that serve as precursors of the unit (c), and these It is preferable to contain 0 to 50% by weight, and further 0 to 25% by weight, of other vinyl monomers copolymerizable with. If the proportion of the unit containing the acrylate ester is less than 50% by weight, the physical properties, particularly the elongation of the tensile properties, which are characteristic when using the acrylate ester, may be reduced by / J.
[0076] アクリル系重合体ブロック（a)の分子量は、必要とされる弾性率とゴム弾性、その重 合に必要な時間など力も決めればょ 、。アクリル系重合体ブロック（a)の数平均分子 量（M )の範囲を例示すると、好ましくは M > 3000、より好ましくは M > 5000、更 [0076] The molecular weight of the acrylic polymer block (a) can be determined by determining the required elastic modulus and rubber elasticity, and the time required for the polymerization. An example of the range of the number average molecular weight (M) of the acrylic polymer block (a) is preferably M> 3000, more preferably M> 5000,
A A A A A A
【こ好ましく ίま M > 10000、特【こ好ましく ίま M > 20000、最ち好ましく ίま M >4000  [Preferably ί M> 10000, Special [Preferably ί M> 20000, Most preferably ί M> 4000
A A A  A A A
0である。アクリル系重合体ブロック (a)の数平均分子量 (M )が前記の範囲より小さ  0. The number average molecular weight (M) of the acrylic polymer block (a) is smaller than the above range.
A  A
いと、成形品の引張伸びが低くなる。メタアクリル系重合体ブロック (a)の数平均分子 量 (M )の上限については、数平均分子量 (M )が大きいと、重合時間が長くなる傾 As a result, the tensile elongation of the molded product is lowered. Regarding the upper limit of the number average molecular weight (M) of the methacrylic polymer block (a), if the number average molecular weight (M) is large, the polymerization time tends to be long.
A A A A
向があるため、必要とする生産性に応じて設定すればよいが、好ましくは 500000以 下であり、更に好ましくは 300000以下である。  Therefore, it may be set according to the required productivity, but is preferably 500000 or less, and more preferably 300000 or less.
[0077] アクリル系重合体ブロック（a)を構成するアクリル酸エステルとしては、例えば、 アクリル酸メチル、アクリル酸ェチル、アクリル酸 n—プロピル、アクリル酸 n—ブチル 、アクリル酸イソブチル、アクリル酸 n—ペンチル、アクリル酸 n—へキシル、アクリル酸 n—へプチル、アクリル酸 n—ォクチル、アクリル酸 2—ェチルへキシル、アクリル酸ノ -ル、アクリル酸デシル、アクリル酸ドデシル、アクリル酸ステアリルなどのアクリル酸 脂肪族炭化水素（例えば炭素数 1〜18のアルキル)エステル； アクリル酸シクロへキシル、アクリル酸イソボル-ルなどのアクリル酸脂環式炭化水 素エステノレ； [0077] As the acrylic ester constituting the acrylic polymer block (a), for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-acrylate Acrylics such as pentyl, n-hexyl acrylate, n-heptyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, nor acrylate, decyl acrylate, dodecyl acrylate, stearyl acrylate, etc. Acid aliphatic hydrocarbon (eg, alkyl having 1 to 18 carbon atoms) ester; Acrylic acid cycloaliphatic hydrocarbon ester such as cyclohexyl acrylate and isoborn acrylate;
アクリル酸フエ-ル、アクリル酸トルィルなどのアクリル酸芳香族炭化水素エステル； アクリル酸ベンジルなどのアクリル酸ァラルキルエステル、アクリル酸 2—メトキシェ チル、アクリル酸 3—メトキシブチルなどのアクリル酸とエーテル性酸素を有する官能 基含有アルコールとのエステル；  Acrylic acid aromatic hydrocarbon esters such as acrylic acid acrylic and acrylic acid acrylic acid; aralkyl acrylates such as benzyl acrylate; acrylic acid and ether such as 2-methoxyethyl acrylate and 3-methoxybutyl acrylate An ester with a functional group-containing alcohol having functional oxygen;
アクリル酸トリフルォロメチルメチル、アクリル酸 2—トリフルォロメチルェチル、アタリ ル酸 2—パーフルォロェチルェチル、アクリル酸 2—パーフルォロェチルー 2—パー フルォロブチルェチル、アクリル酸 2—パーフルォロェチル、アクリル酸パーフルォロ メチル、アクリル酸ジパーフルォロメチルメチル、アクリル酸 2—パーフルォロメチルー 2—パーフルォロェチルメチル、アクリル酸 2—パーフルォ口へキシルェチル、アタリ ル酸 2—パーフルォロデシルェチル、アクリル酸 2—パーフルォ口へキサデシルェチ ルなどのアクリル酸フッ化アルキルエステル；  Trifluoromethylmethyl acrylate, 2-trifluoromethylethyl acrylate, 2-perfluoroethylethyl acrylate, 2-perfluoroethyl 2-acrylobutylethyl acrylate , 2-perfluoroethyl acrylate, perfluoromethyl acrylate, diperfluoromethyl methyl acrylate, 2-perfluoromethyl acrylate 2-perfluoroethyl methyl, 2-perfluoro mouth Fluorinated alkyl acrylates such as hexylethyl, 2-perfluorodecylethyl acrylate, and 2-perfluorohexadecyl acrylate;
などが挙げられる。これらは単独で使用してもよく 2種以上を組み合わせて使用して もよい。これらのアクリル酸エステルの中でも、低温特性、圧縮永久歪、コストおよび 入手しやすさの点から、アクリル酸 n—ブチルが好ましい。耐油性と機械特性が必要 な場合には、アクリル酸ェチルが好ましい。低温特性と機械特性と圧縮永久歪が必 要な場合には、アクリル酸 2—ェチルへキシルが好ましい。機械特性と耐油性および 低温特性の点から、アクリル系重合体ブロック（a)全体中、アクリル酸 2—メトキシェチ ル 10〜90重量0 /0、アクリル酸 n—ブチル 10〜90重量0 /0、アクリル酸ェチル 0〜80 重量％の混合物が好ましぐ更にはアクリル酸 2—メトキシェチル 15〜85重量％、ァ クリル酸 n—ブチル 15〜85重量％、アクリル酸ェチル 0〜70重量％の混合物が好ま しい。 Etc. These may be used alone or in combination of two or more. Among these acrylate esters, n-butyl acrylate is preferable from the viewpoint of low-temperature characteristics, compression set, cost, and availability. Ethyl acrylate is preferred when oil resistance and mechanical properties are required. 2-Ethylhexyl acrylate is preferred when low temperature properties, mechanical properties and compression set are required. From the viewpoint of mechanical properties and oil resistance and low-temperature characteristics, in the total acrylic polymer block (a), acrylic acid 2-Metokishechi Le 10-90 wt 0/0, acrylate n- butyl 10-90 wt 0/0, A mixture of 0 to 80% by weight of ethyl acrylate is preferred, and 15 to 85% by weight of 2-methoxyethyl acrylate, 15 to 85% by weight of n-butyl acrylate, and 0 to 70% by weight of ethyl acrylate. I like it.
また、単位 (c)の前駆体となる官能基としては、例えば、アクリル酸 t—プチル、アタリ ル酸イソプロピル、アクリル酸 α , aージメチルベンジル、アクリル酸 α—メチルベン ジル、メタアクリル酸 tーブチル、メタアクリル酸イソプロピル、メタアクリル酸 α , α—ジ メチルベンジル、メタアクリル酸 α—メチルベンジルなどが挙げられる力 これらに限 定されない。なお、アクリル系ブロック共重合体 (Α)に、単位 (c)を導入する方法は後 述する。 Examples of the functional group serving as a precursor of the unit (c) include t-butyl acrylate, isopropyl acrylate, α, a-dimethylbenzyl acrylate, α-methylbenzyl acrylate, and t-butyl methacrylate. , Isopropyl methacrylate, α, α-dimethylbenzyl methacrylate, α-methylbenzyl methacrylate, and the like, but are not limited thereto. The method for introducing the unit (c) into the acrylic block copolymer (Α) is described later. Describe.
[0079] 更に、アクリル系重合体ブロック (a)を構成する、前記アクリル酸エステルと共重合 可能なビュル系単量体としては、例えばメタアクリル酸エステル、芳香族アルケニル 化合物、シアン化ビニル化合物、共役ジェン系化合物、ハロゲン含有不飽和化合物 、不飽和ジカルボン酸化合物、ビニルエステル化合物、マレイミド系化合物などが挙 げられる。  [0079] Further, examples of the bulle monomer that can be copolymerized with the acrylate ester constituting the acryl polymer block (a) include methacrylic acid esters, aromatic alkenyl compounds, vinyl cyanide compounds, Examples include conjugation compounds, halogen-containing unsaturated compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, and maleimide compounds.
[0080] 前記メタアクリル酸エステルとしては、例えば、  [0080] Examples of the methacrylic acid ester include:
メタアクリル酸メチル、メタアクリル酸ェチル、メタアクリル酸 n—プロピル、メタアタリ ル酸 n—ブチル、メタアクリル酸イソブチル、メタアクリル酸 n ペンチル、メタアクリル 酸 n キシル、メタアクリル酸 n プチル、メタアクリル酸 n—ォクチル、メタアタリ ル酸 2—ェチルへキシル、メタアクリル酸ノエル、メタアクリル酸デシル、メタアクリル酸 ドデシル、メタアクリル酸ステアリルなどのメタアクリル酸脂肪族炭化水素（例えば炭素 数 1 18のアルキル）エステル；  Methyl methacrylate, ethyl acrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n pentyl methacrylate, methacrylate n xyl, methacrylate n butyl, methacrylate n-octyl, 2-ethylhexyl methacrylate, noel methacrylate, decyl methacrylate, dodecyl methacrylate, stearyl methacrylate, etc., aliphatic aliphatic hydrocarbons (eg, C 1 18 alkyl) Ester;
メタアクリル酸シクロへキシル、メタアクリル酸イソボル-ルなどのメタアクリル酸脂環 式炭化水素エステル；  Methacrylic acid alicyclic hydrocarbon esters such as cyclohexyl methacrylate and isoborn methacrylate;
メタアクリル酸ベンジルなどのメタアクリル酸ァラルキルエステル；  Methacrylic acid aralkyl esters such as benzyl methacrylate;
メタアクリル酸フエ-ル、メタアクリル酸トルィルなどのメタアクリル酸芳香族炭化水素 エステル；  Methacrylic acid aromatic hydrocarbon esters such as methacrylic acid phenol and methacrylic acid toluene;
メタアクリル酸 2—メトキシェチル、メタアクリル酸 3—メトキシブチルなどのメタアタリ ル酸とエーテル性酸素を有する官能基含有アルコールとのエステル；  Esters of methacrylic acid such as 2-methoxyethyl methacrylate and 3-methoxybutyl methacrylate and functional group-containing alcohols having etheric oxygen;
メタアクリル酸トリフルォロメチルメチル、メタアクリル酸 2—トリフルォロメチルェチル 、メタアクリル酸 2—パーフルォロェチルェチル、メタアクリル酸 2—パーフルォロェチ ルー 2—パーフルォロブチルェチル、メタアクリル酸 2—パーフルォロェチル、メタァ クリル酸パーフルォロメチル、メタアクリル酸ジパーフルォロメチルメチル、メタアクリル 酸 2—パーフルォロメチル 2—パーフルォロェチルメチル、メタアクリル酸 2—パー フルォ口へキシルェチル、メタアクリル酸 2—パーフルォロデシルェチル、メタアクリル 酸 2—パーフルォ口へキサデシルェチルなどのメタアクリル酸フッ化アルキルエステ ル； などが挙げられる。 Trifluoromethyl methyl methacrylate, 2-trifluoromethylethyl methacrylate, 2-perfluoroethyl methacrylate, 2-perfluorobutyl 2-perfluorobutylethyl methacrylate , 2-perfluoroethyl methacrylate, perfluoromethyl methacrylate, diperfluoromethyl methyl methacrylate, 2-perfluoromethyl methacrylate 2-perfluoromethyl Methacrylic acid fluorinated alkyl esters such as 2-perfluorohexoxylmethacrylate, 2-perfluorodecylmethacrylate, methacrylic acid 2-perfluorodecylethyl; Etc.
[0081] 前記芳香族ァルケ-ルイ匕合物としては、例えばスチレン、 α—メチルスチレン、 ρ— メチルスチレン、 ρ—メトキシスチレンなどが挙げられる。  [0081] Examples of the aromatic alkenyl compound include styrene, α-methylstyrene, ρ-methylstyrene, and ρ-methoxystyrene.
[0082] 前記シアンィ匕ビ-ルイ匕合物としては、例えばアクリロニトリル、メタタリ口-トリルなど が挙げられる。 [0082] Examples of the cyanobi-loui compound include acrylonitrile, meta-tallow-tolyl and the like.
[0083] 前記共役ジェン系化合物としては、例えばブタジエン、イソプレンなどが挙げられる  [0083] Examples of the conjugation compound include butadiene and isoprene.
[0084] 前記ハロゲン含有不飽和化合物としては、例えば塩ィ匕ビニル、塩ィ匕ビユリデン、パ 一フルォロエチレン、パーフルォロプロピレン、フッ化ビ-リデンなどが挙げられる。 [0084] Examples of the halogen-containing unsaturated compound include salt vinyl, salt vinylidene, perfluoroethylene, perfluoropropylene, and vinylidene fluoride.
[0085] 前記不飽和ジカルボン酸化合物としては、例えば無水マレイン酸、マレイン酸、マ レイン酸のモノアルキルエステルおよびジアルキルエステル、フマル酸、フマル酸の モノアルキルエステルおよびジアルキルエステルなどが挙げられる。  [0085] Examples of the unsaturated dicarboxylic acid compound include maleic anhydride, maleic acid, monoalkyl esters and dialkyl esters of maleic acid, fumaric acid, monoalkyl esters and dialkyl esters of fumaric acid, and the like.
[0086] 前記ビュルエステル化合物としては、例えば酢酸ビュル、プロピオン酸ビュル、ピ ノ リン酸ビュル、安息香酸ビニル、桂皮酸ビュルなどが挙げられる。  [0086] Examples of the burester compound include butyl acetate, butyl propionate, butyl benzoate, vinyl benzoate and cinnamate bur.
[0087] 前記マレイミド系化合物としては、例えばマレイミド、メチルマレイミド、ェチルマレイ ミド、プロピルマレイミド、ブチルマレイミド、へキシルマレイミド、ォクチルマレイミド、ド デシルマレイミド、ステアリルマレイミド、フエ-ルマレイミド、シクロへキシルマレイミド などが挙げられる。  [0087] Examples of the maleimide compounds include maleimide, methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, phenolmaleimide, cyclohexylmaleimide and the like. Can be mentioned.
[0088] これらのビニル系単量体は、単独で使用してもよく 2種以上を組み合わせて使用し てもよい。前記ビュル系単量体は、アクリル系重合体ブロック (a)に要求されるガラス 転移温度、弾性率、極性、また、アクリル系ブロック共重合体 (A)が組成物として使用 される場合に要求される物性、ォレフィン系熱可塑性エラストマ一（B)や、後述するポ リオルガノシロキサン系グラフト重合体 (D)との相溶性などによって好まし!/、ものを選 択することができる。例えば、耐油性の向上を目的としてアクリロニトリルを共重合させ ることがでさる。  [0088] These vinyl monomers may be used alone or in combination of two or more. The bulle monomer is required for the glass transition temperature, elastic modulus and polarity required for the acrylic polymer block (a), and when the acrylic block copolymer (A) is used as a composition. Can be selected depending on the physical properties to be used and the compatibility with the polyolefin thermoplastic elastomer (B) and the polyorganosiloxane graft polymer (D) described later. For example, acrylonitrile can be copolymerized for the purpose of improving oil resistance.
[0089] アクリル系重合体ブロック（a)のガラス転移温度 (Tg )は、好ましくは 50°C以下、より  [0089] The glass transition temperature (Tg) of the acrylic polymer block (a) is preferably 50 ° C or lower.
a  a
好ましくは 0°C以下である。ガラス転移温度が 50°Cより高いと、アクリル系ブロック共 重合体 (A)のゴム弾性が低下することがある。アクリル系重合体ブロック（a)のガラス 転移温度 (Tg )の設定は、重合体ブロックを構成する各単量体のホモポリマーのガラ a Preferably it is 0 ° C or less. If the glass transition temperature is higher than 50 ° C, the rubber elasticity of the acrylic block copolymer (A) may decrease. Acrylic polymer block (a) glass The transition temperature (Tg) is set according to the homopolymer gala of each monomer constituting the polymer block.
ス転移温度として前述のポリマー ハンドブック 3版 に記載の値を用い、各単量体 の重合比率から、前記 Foxの式にした力^、、重合体ブロックを構成する単量体の重 量割合を調節することで行うことができる。  Using the values described in the 3rd edition of the above-mentioned Polymer Handbook as the transition temperature, from the polymerization ratio of each monomer, the force expressed in the Fox formula, and the weight ratio of the monomers constituting the polymer block are calculated. It can be done by adjusting.
[0090] 次に、メタアクリル系重合体ブロック (b)は、所望する物性のアクリル系ブロック共重 合体 (A)を得やすい点、コストおよび入手のしゃすさの点から、メタアクリル系重合体 ブロック（b)全体中、メタアクリル酸エステルを含有する単位を 50〜100重量。 /0、好ま しくは 50〜85重量％含有し、単位 (c)の前駆体となる官能基を有する単量体を 10〜 99. 5重量％、好ましくは 20〜99. 5重量％含有し、且つこれらの単量体と共重合可 能な他のビュル系単量体を 0. 1〜50重量％、好ましくは 0. 1〜25重量％含有する ことが好ましい。 [0090] Next, the methacrylic polymer block (b) is a methacrylic polymer from the viewpoint that it is easy to obtain an acrylic block copolymer (A) having the desired physical properties, cost and availability. 50 to 100 weight units containing methacrylic acid ester in the entire block (b). / 0 , preferably 50 to 85% by weight, and containing 10 to 99.5% by weight, preferably 20 to 99.5% by weight of a monomer having a functional group as a precursor of the unit (c). Further, it is preferable to contain 0.1 to 50% by weight, preferably 0.1 to 25% by weight, of other bulle monomers copolymerizable with these monomers.
[0091] メタアクリル系重合体ブロック (b)の分子量は、必要とされる凝集力や、その重合に 必要な時間など力 決めればよい。前記凝集力は、分子間の相互作用（いい換えれ ば極性）と絡み合いの度合いに依存するとされており、数平均分子量を増やすほど 絡み合い点が増加して凝集力が増加する。即ち、メタアクリル系重合体ブロック (b)を 構成する重合体の絡み合い点の間の分子量を Mcとして、メタアクリル系重合体プロ  [0091] The molecular weight of the methacrylic polymer block (b) may be determined based on the cohesive force required and the time required for the polymerization. The cohesive force is said to depend on the interaction between molecules (in other words, polarity) and the degree of entanglement, and as the number average molecular weight increases, the entanglement point increases and the cohesive force increases. That is, the molecular weight between the entanglement points of the polymer constituting the methacrylic polymer block (b) is Mc, and the methacrylic polymer pro
B  B
ック (b)の数平均分子量 (M )の範囲を例示すると、凝集力が必要な場合には、好ま  For example, the range of number average molecular weight (M) of the rubber (b) is preferred when cohesion is required.
B  B
しくは M >Mcである。更に例をあげると、さらなる凝集力が必要とされるときには、 Or M> Mc. For example, when more cohesion is needed,
B B B B
好ましくは M > 2 X Mcである。逆に、ある程度の凝集力とクリープ性を両立させた  Preferably, M> 2 X Mc. On the contrary, a certain level of cohesion and creep properties were achieved.
B B  B B
いときには、 Mc < M < 2 X Mcが好ましい。絡み合い点の間の分子量は、ゥ（Wu)  If so, Mc <M <2 X Mc is preferred. The molecular weight between the entanglement points is Wu
B B B  B B B
らの文献（ポリマー エンジニアリング アンド サイエンス（Polym. Eng. and Sci. ) , 1990年、 30卷、 753頁)などを参照すればよい。例えば、メタアクリル系重合体ブ ロック (b)力 すべてメタアクリル酸メチルカも構成されているとして、凝集力が必要と される場合のメタアクリル系重合体ブロック (b)の数平均分子量 (M )の範囲を例示  References (Polym. Eng. And Sci., 1990, 30 pp. 753) and the like may be referred to. For example, the number average molecular weight (M) of the methacrylic polymer block (b) when cohesive force is required, assuming that all of the methacrylic polymer block (b) force is also composed of methyl methacrylate. Explain the range of
B  B
すると、 9200以上が好ましい。ただし、単位 (c)がメタアクリル系重合体ブロック (b) に含有される場合には、単位 (c)による凝集力が付与されるので、メタアクリル系重合 体ブロック (b)の数平均分子量 (M )は、前記の値より低く設定できる。メタアクリル系  Then, 9200 or more is preferable. However, when the unit (c) is contained in the methacrylic polymer block (b), the cohesive force by the unit (c) is given, so the number average molecular weight of the methacrylic polymer block (b) (M 1) can be set lower than the above value. Methacrylic
B  B
重合体ブロック (b)の数平均分子量 (M )の上限については、数平均分子量 (M )が 大きくなると、重合時間が長くなる傾向にあるため、必要とする生産性に応じて設定 すればよいが、好ましくは 200000以下、更に好ましくは 100000以下である。 Regarding the upper limit of the number average molecular weight (M) of the polymer block (b), the number average molecular weight (M) is As the polymerization time increases, the polymerization time tends to be longer, so it may be set according to the required productivity, but is preferably 200,000 or less, more preferably 100,000 or less.
[0092] メタアクリル系重合体ブロック (b)を構成するメタアクリル酸エステルとしては、前記 アクリル系重合体ブロック (a)を構成する、アクリル酸エステルと共重合可能なビニル 系単量体として例示したものが挙げられる。これらメタアクリル酸エステルは単独で使 用してもよく 2種以上を組み合わせて使用してもよい。これらの中でも、コストおよび入 手しやすさの点から、メタアクリル酸メチルが好まし 、。 [0092] The methacrylic acid ester constituting the methacrylic polymer block (b) is exemplified as a vinyl monomer copolymerizable with the acrylate ester constituting the acrylic polymer block ( a ). The thing which was done is mentioned. These methacrylic acid esters may be used alone or in combination of two or more. Of these, methyl methacrylate is preferred from the viewpoint of cost and availability.
[0093] 単位 (c)の前駆体となる官能基を有する単量体としては、前記アクリル系重合体ブ ロック（a)の説明で例示した構成単量体と同様の単量体が挙げられる。 [0093] Examples of the monomer having a functional group serving as a precursor of the unit (c) include monomers similar to the constituent monomers exemplified in the description of the acrylic polymer block (a). .
[0094] メタアクリル系重合体ブロック (b)を構成する、メタアクリル酸エステルと共重合可能 なビュル系単量体としては、例えばアクリル酸エステル、芳香族アルケニル化合物、 シアン化ビニル化合物、共役ジェン系化合物、ハロゲン含有不飽和化合物、不飽和 ジカルボン酸ィ匕合物、ビニルエステル化合物、マレイミド系化合物などが挙げられる 。上記の共重合可能なビニル系単量体は、上記構成単量体のうちから少なくとも 1種 使用される。 [0094] Examples of the bull monomers that can be copolymerized with the methacrylic acid ester that constitute the methacrylic polymer block (b) include acrylic acid esters, aromatic alkenyl compounds, vinyl cyanide compounds, conjugated genes. Compounds, halogen-containing unsaturated compounds, unsaturated dicarboxylic acid compounds, vinyl ester compounds, maleimide compounds, and the like. The copolymerizable vinyl monomer is used in at least one of the above constituent monomers.
[0095] 前記アクリル酸エステルとしては、前記アクリル系重合体ブロック（a)の説明で例示 した構成単量体と同様の単量体が挙げられる。  [0095] Examples of the acrylic ester include monomers similar to the constituent monomers exemplified in the description of the acrylic polymer block (a).
[0096] 前記芳香族ァルケ-ルイ匕合物、シアン化ビニル化合物、共役ジェン系化合物、ハ ロゲン含有不飽和化合物、不飽和ジカルボン酸化合物、ビニルエステル化合物、マ レイミド系化合物としては、前記アクリル系重合体ブロック (a)の説明で共重合可能な ビニル系単量体として例示した構成単量体と同様の単量体が挙げられる。  [0096] Examples of the aromatic alk-louie compound, vinyl cyanide compound, conjugated-gen compound, halogen-containing unsaturated compound, unsaturated dicarboxylic acid compound, vinyl ester compound, and maleimide compound include the acrylic-based compound. Examples thereof include the same monomers as the constituent monomers exemplified as the vinyl monomer that can be copolymerized in the description of the polymer block (a).
[0097] メタアクリル酸メチルの重合体は、熱分解によりほぼ定量的に解重合する力 それ を抑えるために、メタアクリル系重合体ブロック (b)がメタアクリル酸メチルの重合体か らなる場合には、アクリル酸エステル、例えばアクリル酸メチル、アクリル酸ェチル、ァ クリル酸ブチル、アクリル酸 2—メトキシェチルもしくはそれらの混合物またはスチレン などを共重合させることができる。更に、メタアクリル系重合体ブロック (b)には、耐油 性の向上を目的として、アクリロニトリルを共重合させることができる。  [0097] The methyl methacrylate polymer has the ability to depolymerize almost quantitatively by thermal decomposition. In order to suppress this, the methacrylic polymer block (b) is composed of a methyl methacrylate polymer. Can be copolymerized with acrylic acid esters such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-methoxyethyl acrylate or mixtures thereof, or styrene. Furthermore, acrylonitrile can be copolymerized with the methacrylic polymer block (b) for the purpose of improving oil resistance.
[0098] メタアクリル系重合体ブロック (b)のガラス転移温度 (Tg )は、好ましくは 100°C以上 、より好ましくは 110°C以上である。ガラス転移温度 (Tg )が 100°C未満の場合、高温 [0098] The glass transition temperature (Tg) of the methacrylic polymer block (b) is preferably 100 ° C or higher. More preferably, the temperature is 110 ° C or higher. High temperature when glass transition temperature (Tg) is less than 100 ° C
b  b
でのゴム弾性が所望の値より低下することがある。メタアクリル系重合体ブロック (b)の ガラス転移温度 (Tg )の設定は、重合体ブロックを構成する各単量体のホモポリマー  The rubber elasticity at may be lower than the desired value. The glass transition temperature (Tg) of the methacrylic polymer block (b) is set by the homopolymer of each monomer constituting the polymer block.
b  b
のガラス転移温度として前述のポリマー ハンドブック 3版 に記載の値を用い、各 単量体の重合比率から、前記 Foxの式にしたがい、重合体ブロックを構成する単量 体の重量割合を調節することにより行うことができる。  Using the values described in the above-mentioned Polymer Handbook 3rd edition as the glass transition temperature of the polymer, the weight ratio of the monomer constituting the polymer block is adjusted from the polymerization ratio of each monomer according to the above Fox formula. Can be performed.
[0099] アクリル系重合体ブロック（a)および Zまたはメタアクリル系重合体ブロック (b)にお ける反応性官能基 (単位 (c) )は、アミノ基、水酸基、エポキシ基などを有する化合物 との反応性を有するので、アクリル系ブロック共重合体 (A)を熱可塑性エラストマ一（ B)とブレンドする場合の相溶化剤 (C)との架橋部位などとして用いることができる特 徴を有する。また、単位 (c)はガラス転移温度 (Tg)が高いので、ハードセグメントであ るメタアクリル系重合体ブロック (b)に導入すると、アクリル系ブロック共重合体 (A)の 耐熱性が向上する。即ち、単位 (c)を含有する重合体のガラス転移温度は、例えば ポリメタアクリル酸無水物の場合で 159°Cと高ぐ単位 (c)を導入することで、アクリル 系ブロック共重合体 (A)の耐熱性が向上するので好ま Uヽ。  [0099] The reactive functional group (unit (c)) in the acrylic polymer block (a) and the Z or methacrylic polymer block (b) is a compound having an amino group, a hydroxyl group, an epoxy group, or the like. Therefore, the acrylic block copolymer (A) can be used as a crosslinking site with the compatibilizing agent (C) when blended with the thermoplastic elastomer (B). In addition, since the unit (c) has a high glass transition temperature (Tg), when introduced into the methacrylic polymer block (b), which is a hard segment, the heat resistance of the acrylic block copolymer (A) is improved. . That is, the glass transition temperature of the polymer containing the unit (c) is, for example, in the case of polymethacrylic anhydride, by introducing a unit (c) that is as high as 159 ° C., the acrylic block copolymer ( U) is preferred because it improves the heat resistance of A).
[0100] 単位 (c)は、一般式（1) :  [0100] Unit (c) is the general formula (1):
[化 3]  [Chemical 3]
Figure imgf000035_0001
Figure imgf000035_0001
(式中、 R1は水素原子またはメチル基で、互いに同一でも異なっていてもよぐ pは 0 または 1の整数、 qは 0〜3の整数）、で表わされる酸無水物基を含有する単位 (cl) および Zまたはカルボキシル基を含有する単位 (c2)からなる。 一般式（1)中の qは 0〜3の整数、好ましくは 0または 1であり、より好ましくは 1である 。 qが 3を超える、重合が煩雑になったり、酸無水物基への環化が困難になることがあ る。 (Wherein R 1 is a hydrogen atom or a methyl group, which may be the same or different from each other, p is an integer of 0 or 1, q is an integer of 0 to 3), and contains an acid anhydride group represented by Unit (cl) and unit (c2) containing Z or carboxyl group. Q in the general formula (1) is an integer of 0 to 3, preferably 0 or 1, and more preferably 1. If q exceeds 3, polymerization may become complicated, and cyclization to an acid anhydride group may be difficult.
一般式（1)中の pは 0または 1の整数であって、 qが 0の場合には pも 0であり、 qが 1 〜3の場合には、 pは 1が好ましい。  In general formula (1), p is an integer of 0 or 1. When q is 0, p is also 0. When q is 1 to 3, p is preferably 1.
[0101] 単位 (c)は、アクリル系重合体ブロック（a)および Zまたはメタアクリル系重合体ブロ ック (b)に含有される。単位 (c)の導入部位は、アクリル系ブロック共重合体 (A)の反 応点や、アクリル系ブロック共重合体 (A)を構成するブロックの凝集力やガラス転移 温度、更には必要とされるアクリル系ブロック共重合体 (A)の物性などに応じて適宜 選択される。また、アクリル系ブロック共重合体 (A)の耐熱性や耐熱分解性の向上の 観点からは、単位 (c)をメタアクリル系重合体ブロック (b)に導入すればよぐアクリル 系ブロック共重合体 (A)にゴム弾性を付与する観点からは、単位 (c)をアクリル系重 合体ブロック (a)に、架橋性の反応部位 (架橋点）として導入すればよい。反応点の 制御や、耐熱性、ゴム弾性などの点からは、単位 (c)をアクリル系重合体ブロック (a) またはメタアクリル系重合体ブロック (b)の 、ずれか一方に有することが好ま 、。ま た、単位 (c)をメタアクリル系重合体ブロック (b)に含む場合には、一般式（1)の R1は 共にメチル基が好ましぐアクリル系重合体ブロック（a)に含む場合には、一般式（1) の R1が水素原子が好ましい。単位 (c)をメタアクリル系重合体ブロック (b)に含む場合 に R1が水素原子である場合や、単位 (c)をアクリル系重合体ブロック（a)に含む場合 に R1がメチル基である場合には、アクリル系重合体ブロック (a)とメタアクリル系重合 体ブロック (b)とのガラス転移温度の差が小さくなり、アクリル系ブロック共重合体 (A) のゴム弾性が低下する傾向にある。 [0101] The unit (c) is contained in the acrylic polymer block (a) and the Z or methacrylic polymer block (b). The introduction site of the unit (c) is required for the reaction point of the acrylic block copolymer (A), the cohesive force and glass transition temperature of the block constituting the acrylic block copolymer (A), and further. Depending on the physical properties of the acrylic block copolymer (A) to be selected, it is appropriately selected. In addition, from the viewpoint of improving the heat resistance and heat decomposability of the acrylic block copolymer (A), it is sufficient to introduce the unit (c) into the methacrylic polymer block (b). From the viewpoint of imparting rubber elasticity to the polymer (A), the unit (c) may be introduced into the acrylic polymer block ( a ) as a crosslinkable reaction site (crosslinking point). From the viewpoints of reaction point control, heat resistance, rubber elasticity, etc., it is preferable to have the unit (c) in either one of the acrylic polymer block (a) or the methacrylic polymer block (b). ,. When the unit (c) is contained in the methacrylic polymer block (b), R 1 in the general formula (1) is contained in the acrylic polymer block (a) in which both methyl groups are preferred. For this, R 1 in formula (1) is preferably a hydrogen atom. When the unit (c) is contained in the methacrylic polymer block (b), R 1 is a hydrogen atom, or when the unit (c) is contained in the acrylic polymer block (a), R 1 is a methyl group. The difference in glass transition temperature between the acrylic polymer block (a) and the methacrylic polymer block (b) is reduced, and the rubber elasticity of the acrylic block copolymer (A) is reduced. There is a tendency.
[0102] 単位 (c)の含有量の好ましい範囲は、単位 (c)の凝集力、相溶化剤 (C)との反応性 、アクリル系ブロック共重合体 (A)の構造および組成、アクリル系ブロック共重合体（ A)を構成するブロックの数、ガラス転移温度ならびに酸無水物基含有単位 (cl)や力 ルポキシル基含有単位 (c2)の含有される部位および様式によって変化する。単位 ( c)の含有量の好ましい範囲は、アクリル系ブロック共重合体 (A)全体中、 0. 1-99. 9重量％が好ましぐ 0. 1〜80重量％がより好ましぐ 0. 1〜50重量％が更に好まし い。単位 (c)の含有量が 0. 1重量％より少ないと、アクリル系ブロック共重合体 (A)と 相溶化剤（C)との相溶性が不充分になる場合がある。また、メタアクリル系重合体ブ ロック（b)の耐熱性向上を目的に、 Tgの高い単位 (c)をノヽードセグメントであるメタァ クリル系重合体ブロック (b)に導入する場合、 0. 1重量％より少ないと、耐熱性の向 上が不充分であり、高温におけるゴム弾性の発現が低下する場合がある。一方、 99 . 9重量％を超えると、凝集力が強くなりすぎるため生産性が低下することがある。 [0102] The preferred range of the content of the unit (c) is the cohesive strength of the unit (c), the reactivity with the compatibilizer (C), the structure and composition of the acrylic block copolymer (A), the acrylic type It varies depending on the number of blocks constituting the block copolymer (A), the glass transition temperature, and the site and manner in which the acid anhydride group-containing unit (cl) and force lpoxyl group-containing unit (c2) are contained. A preferable range of the content of the unit (c) is 0.1 to 99.9% by weight in the entire acrylic block copolymer (A), and 0.1 to 80% by weight is more preferable. 1-50% by weight is more preferred Yes. If the content of the unit (c) is less than 0.1% by weight, the compatibility between the acrylic block copolymer (A) and the compatibilizer (C) may be insufficient. In order to improve the heat resistance of the methacrylic polymer block (b), when a unit (c) having a high Tg is introduced into the methacrylic polymer block (b), which is a node segment, 0. If it is less than 1% by weight, the heat resistance may not be sufficiently improved, and the development of rubber elasticity at high temperatures may be reduced. On the other hand, if it exceeds 99.9% by weight, the cohesive force becomes too strong, and the productivity may be lowered.
[0103] アクリル系ブロック共重合体 (A)がカルボキシル基を含有する単位 (c2)を含んで ヽ ると、耐熱性や凝集力が向上する。カルボキシル基を含有する単位 (c2)は強い凝集 力をもち、カルボキシル基を含有する単量体の重合体はガラス転移温度 (Tg)が高く 、例えばポリメタアクリル酸のガラス転移温度 (Tg)は 228°Cと高ぐブロック共重合体 (A)の耐熱性を向上させる。ヒドロキシル基などの官能基も水素結合能を有すが、力 ルポキシル基を含有する単位 (c2)と比較すると、 Tgが低ぐ耐熱性を向上させる効 果は小さい。従って、カルボキシル基を含有する単位 (c2)を含有していれば、アタリ ル系ブロック共重合体 (A)の耐熱性や凝集力を更に向上させることができ、好ま ヽ [0103] If the acrylic block copolymer (A) contains a unit (c2) containing a carboxyl group, the heat resistance and cohesive strength are improved. The carboxyl group-containing unit (c2) has a strong cohesive force, and a polymer of a monomer containing a carboxyl group has a high glass transition temperature (Tg) .For example, the glass transition temperature (Tg) of polymethacrylic acid is Improves heat resistance of block copolymer (A), which is as high as 228 ° C. Functional groups such as hydroxyl groups also have hydrogen-bonding ability, but the effect of improving heat resistance is low compared to the unit (c2) containing a strong lpoxyl group, which is low. Therefore, if the unit containing a carboxyl group (c2) is contained, the heat resistance and cohesive strength of the talyl block copolymer (A) can be further improved, which is preferable.
[0104] カルボキシル基を含有する単位 (c2)の含有量は、重合体ブロック 1個あたり 1個ま たは 2個以上であるのが好ましい。重合体ブロック 1個あたりの単位 (c2)の数が 2個 以上である場合、その単位 (c2)が重合されている様式は、ランダム共重合であって もよくブロック共重合でもよ ヽ。 [0104] The content of the carboxyl group-containing unit (c2) is preferably 1 or 2 or more per polymer block. When the number of units (c2) per polymer block is 2 or more, the mode in which the units (c2) are polymerized may be random copolymerization or block copolymerization.
[0105] カルボキシル基を含有する単位 (c2)の含有量の好まし!/、範囲は、該単位 (c2)の 凝集力、ブロック共重合体の構造および組成、ブロック共重合体を構成するブロック の数、ならびに、該単位 (c2)の含有される部位および様式によって変化する。カル ボキシル基を有する単位 (c2)の含有量は、アクリル系ブロック共重合体 (A)全体中 、 0. 1〜50重量％が好ましぐ 0. 5〜50重量％がより好ましぐ 1〜40重量％が更に 好ましい。カルボキシル基を含有する単位 (c2)は、高温下で隣接するエステルュ- ットと環化しやすい傾向があるので、アクリル系ブロック共重合体 (A)の単位（c2)の 含有量が 50重量％を超えると、成形加工後の物性が変化し、安定した物性の製品を 作ることが困難になることがある。なお、カルボキシル基を含有する単位 (c2)は重合 体ブロック (b)中に 0. 1重量％以上生成させることが好ましい。該生成量が 0. 1重量[0105] The content of the carboxyl group-containing unit (c2) is preferred! /, The range is the cohesive strength of the unit (c2), the structure and composition of the block copolymer, and the blocks constituting the block copolymer As well as the site and mode of the unit (c2). The content of the unit (c2) having a carboxyl group is preferably 0.1 to 50% by weight, more preferably 0.5 to 50% by weight in the whole acrylic block copolymer (A). More preferred is ˜40% by weight. Since the carboxyl group-containing unit (c2) tends to cyclize with adjacent ester units at high temperatures, the content of the acrylic block copolymer (A) unit (c2) is 50% by weight. Exceeding this may change the physical properties after molding, making it difficult to produce products with stable physical properties. The carboxyl group-containing unit (c2) is polymerized. It is preferable to produce 0.1% by weight or more in the body block (b). The amount produced is 0.1 wt.
%未満の場合、耐熱性や凝集力の向上が不充分となることがある。 If it is less than%, the heat resistance and cohesive strength may be insufficiently improved.
[0106] アクリル系ブロック共重合体 (A)の製造方法は、特に限定されな!、が、制御重合が 好ましい。制御重合としては、リビングァ-オン重合、連鎖移動剤を用いるラジカル重 合および近年開発されたリビングラジカル重合が挙げられる。ブロック共重合体の分 子量および構造制御の点ならびに架橋性官能基を有する単量体を共重合できる点 から、リビングラジカル重合が好ましい。更に制御の容易さなど力 原子移動ラジカル 重合が好ましい。  [0106] The method for producing the acrylic block copolymer (A) is not particularly limited! However, controlled polymerization is preferred. Controlled polymerization includes living-on polymerization, radical polymerization using a chain transfer agent, and recently developed living radical polymerization. Living radical polymerization is preferred from the viewpoints of the molecular weight and structure control of the block copolymer and the ability to copolymerize monomers having a crosslinkable functional group. Further, force atom transfer radical polymerization such as ease of control is preferred.
[0107] 原子移動ラジカル重合は、有機ハロゲン化物、またはハロゲン化スルホ二ルイ匕合物 を開始剤、周期律表第 8族、 9族、 10族、または 11族元素を中心金属とする金属錯 体を触媒として重合される（例えば、 Matyjaszewskiら， Journal of American Chemical Society, 1995, 117, 5614、 Macromolecules, 1995, 28, 7901、 Science, 1996, 272, 866、または Sawamotoら， Macromolecules, 1995, 2 8, 1721) 0 [0107] Atom transfer radical polymerization is a metal complex having an organic halide or a halogenated sulfone compound as an initiator and a Group 8, 9, 10, or 11 element as a central metal in the periodic table. (Eg, Matyjaszewski et al., Journal of American Chemical Society, 1995, 117, 5614, Macromolecules, 1995, 28, 7901, Science, 1996, 272, 866, or Sawamoto et al., Macromolecules, 1995, 2 8, 1721) 0
[0108] これらの方法によると、一般的に非常に重合速度が高ぐラジカル同士のカップリン グなどの停止反応が起こりやす!/、ラジカル重合でありながら、重合がリビング的に進 行し、分子量分布の狭い MwZMn= l . 1〜1. 5程度の重合体が得られ、得られる 重合体の分子量は、モノマーと開始剤の仕込み時の比率によって自由にコントロー ルできる。  [0108] According to these methods, generally, termination reaction such as coupling between radicals having a very high polymerization rate is likely to occur! / Although polymerization is radical polymerization, polymerization proceeds in a living manner. A polymer having a narrow molecular weight distribution of MwZMn = l. 1 to 1.5 is obtained, and the molecular weight of the obtained polymer can be freely controlled by the ratio of the monomer and the initiator when charged.
[0109] 原子移動ラジカル重合法において、開始剤として用いられる有機ハロゲンィ匕物また はハロゲン化スルホニル化合物としては、一官能性、二官能性、または、多官能性の 化合物を使用できる。これらは目的に応じて使い分けできる。ジブロック共重合体を 製造する場合は、一官能性ィ匕合物が好ましい。 a— b— a型のトリブロック共重合体、 b a— b型のトリブロック共重合体を製造する場合は、二官能性ィ匕合物が好ましい。分 岐状ブロック共重合体を製造する場合は、多官能性化合物が好まし ヽ。  [0109] In the atom transfer radical polymerization method, as the organic halide or sulfonyl halide compound used as an initiator, a monofunctional, difunctional, or polyfunctional compound can be used. These can be used properly according to the purpose. When producing a diblock copolymer, a monofunctional compound is preferred. In the case of producing an a—b—a type triblock copolymer and a b a—b type triblock copolymer, a bifunctional compound is preferred. Multifunctional compounds are preferred when producing branched block copolymers.
[0110] 一官能性ィ匕合物としては、例えば、以下の化学式で示される化合物が挙げられる。 [0110] Examples of the monofunctional compound include compounds represented by the following chemical formulas.
C H -CH X  C H -CH X
6 5 2  6 5 2
C H -CHX-CH CH -C(CH ) X CH -CHX-CH CH -C (CH) X
6 5 3 2  6 5 3 2
R1 - CHX - COOR2 R 1 -CHX-COOR 2
R1— C(CH )X-COOR2 R 1 — C (CH) X-COOR 2
3  Three
R1 - CHX - CO - R2 R 1 -CHX-CO-R 2
R1— C(CH )X-CO-R2 R 1 — C (CH) X-CO-R 2
3  Three
R1— CH -SOX R 1 — CH -SOX
6 4 2  6 4 2
(これらの式中、 C Hはフエ-レン基を表わす。フエ-レン基は、オルト置換、メタ置  (In these formulas, CH represents a phenylene group. The phenylene group is an ortho-substituted, meta-substituted group.
6 4  6 4
換およびパラ置換のいずれでもよい。 R1は水素原子または炭素数 1〜20のアルキル 基、炭素数 6〜20のァリール基、または炭素数 7〜20のァラルキル基を表わす。 Xは 塩素、臭素またはヨウ素を表わす。 R2は炭素数 1〜20の一価の有機基を表わす。 ) 二官能性ィ匕合物としては、例えば、以下の化学式で示される化合物が挙げられる。Any of substitution and para substitution may be used. R 1 represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. X represents chlorine, bromine or iodine. R 2 represents a monovalent organic group having 1 to 20 carbon atoms. ) Examples of the bifunctional compound include compounds represented by the following chemical formulas.
X— CH— CH— CH -X X— CH— CH— CH -X
2 6 4 2  2 6 4 2
X— CH(CH ) C H -CH(CH )—X  X— CH (CH) C H —CH (CH) —X
3 6 4 3  3 6 4 3
X-C(CH ) -C H -C(CH ) -X  X-C (CH) -C H -C (CH) -X
3 2 6 4 3 2  3 2 6 4 3 2
X-CH(COOR3) - (CH ) CH(COOR3)— X X-CH (COOR 3 )-(CH) CH (COOR 3 ) — X
2 n  2 n
X— C(CH ) (COOR3) (CH ) C(CH ) (COOR3)—X X— C (CH) (COOR 3 ) (CH) C (CH) (COOR 3 ) —X
3 2 n 3  3 2 n 3
X - CH(COR3) -（CH) CH(COR3) - X X-CH (COR 3 )-(CH) CH (COR 3 )-X
2 n  2 n
X— C(CH ) (COR3) (CH ) C(CH ) (COR3)—X X— C (CH) (COR 3 ) (CH) C (CH) (COR 3 ) —X
3 2 n 3  3 2 n 3
X— CH— CO— CH -X  X— CH— CO— CH -X
2 2  twenty two
X— CH(CH ) CO— CH(CH )—X  X— CH (CH) CO— CH (CH) —X
3 3  3 3
X-C(CH ) -CO-C(CH ) X  X-C (CH) -CO-C (CH) X
3 2 3 2  3 2 3 2
X— CH(C H ) CO— CH(C H )—X  X— CH (C H) CO— CH (C H) —X
6 5 6 5  6 5 6 5
X— CH -COO- (CH ) -OCO-CH -X  X— CH -COO- (CH) -OCO-CH -X
2 2 n 2  2 2 n 2
X-CH(CH ) - COO - (CH ) OCO— CH(CH)— X  X-CH (CH)-COO-(CH) OCO— CH (CH) — X
3 2 n 3  3 2 n 3
X-C(CH ) COO—（CH) -OCO-C(CH ) —X  X-C (CH) COO— (CH) -OCO-C (CH) —X
3 2 2 n 3 2  3 2 2 n 3 2
X— CH— CO— CO— CH -X  X— CH— CO— CO— CH -X
2 2  twenty two
X— CH(CH ) CO— CO— CH(CH )—X  X— CH (CH) CO— CO— CH (CH) —X
3 3  3 3
X-C(CH ) -CO-CO-C(CH ) -X X-CH COO— C H -OCO-CH -X XC (CH) -CO-CO-C (CH) -X X-CH COO— CH -OCO-CH -X
2 6 4 2  2 6 4 2
X— CH (CH ) COO— C H OCO— CH (CH ) -X  X— CH (CH) COO— C H OCO— CH (CH) -X
3 6 4 3  3 6 4 3
X-C (CH ) -COO-C H -OCO-C (CH ) -X  X-C (CH) -COO-C H -OCO-C (CH) -X
3 2 6 4 3 2  3 2 6 4 3 2
X— SO— C H -SO -X  X—SO— C H -SO -X
2 6 4 2  2 6 4 2
(これらの式中、 R3は炭素数 1〜20のアルキル基、炭素数 6〜20ァリール基または 炭素数 7〜20ァラルキル基を表わす。 C Hはフエ-レン基を表わす。フエ-レン基は (In these formulas, R 3 represents an alkyl group having 1 to 20 carbon atoms, a 6 to 20 aryl group, or a 7 to 20 aralkyl group. CH represents a phenylene group.
6 4  6 4
、オルト置換、メタ置換およびパラ置換のいずれでもよい。 C Hはフエ-ル基を表わ  , Ortho substitution, meta substitution and para substitution may be used. C H represents a phenol group
6 5  6 5
す。 nは 0〜20の整数を表わす。 Xは塩素、臭素またはヨウ素を表わす。 )  The n represents an integer of 0 to 20. X represents chlorine, bromine or iodine. )
[0112] 多官能性ィ匕合物としては、例えば、以下の化学式で示される化合物が挙げられる。 [0112] Examples of the multifunctional compound include compounds represented by the following chemical formulas.
C H (CH X)  C H (CH X)
6 3 2 3  6 3 2 3
C H (CH (CH ) -X)  C H (CH (CH) -X)
6 3 3 3  6 3 3 3
C H (C (CH ) -X)  C H (C (CH) -X)
6 3 3 2 3  6 3 3 2 3
C H (OCO-CH X)  C H (OCO-CH X)
6 3 2 3  6 3 2 3
C H (OCO-CH (CH ) -X)  C H (OCO-CH (CH) -X)
6 3 3 3  6 3 3 3
C H (OCO— C (CH ) -X)  C H (OCO— C (CH) -X)
6 3 3 2 3  6 3 3 2 3
C H (SO X)  C H (SO X)
6 3 2 3  6 3 2 3
(これらの式中、 C Hは三置換フ -ル基を表わす。三置換フ -ル基は、置換基  (In these formulas, CH represents a tri-substituted full group. The tri-substituted full group represents a substituent.
6 3  6 3
の位置は 1位〜 6位のいずれでもよい。 Xは塩素、臭素またはヨウ素を表わす。 ) [0113] 開始剤として使用できる、これらの有機ハロゲンィ匕物またはハロゲン化スルホ-ル 化合物は、ハロゲンが結合している炭素がカルボ-ル基、フエ-ル基などと結合して おり、炭素 ハロゲン結合が活性化されて重合が開始する。使用する開始剤の量は 、必要とするブロック共重合体の分子量に合わせて、単量体との比力 決定すればよ い。即ち、開始剤 1分子あたり、何分子の単量体を使用するかによって、ブロック共重 合体の分子量を制御できる。  The position of 1 may be any of 1st to 6th positions. X represents chlorine, bromine or iodine. ) [0113] These organic halides or halogenated sulfole compounds that can be used as initiators have carbon bonded to a halogen group, a phenol group, etc. The halogen bond is activated and polymerization starts. The amount of the initiator used may be determined in accordance with the molecular weight of the required block copolymer and the specific power with the monomer. That is, the molecular weight of the block copolymer can be controlled by the number of monomers used per molecule of the initiator.
[0114] 前記原子移動ラジカル重合の触媒として用いられる遷移金属錯体は、特に限定さ れないが、好ましいものとして、 1価および 0価の銅の錯体、 2価のルテニウムの錯体 、 2価の鉄の錯体および 2価のニッケルの錯体が挙げられる。これらの中でも、コスト や反応制御の点から、銅の錯体が好ましい。 [0115] 1価の銅化合物としては、例えば、塩化第一銅、臭化第一銅、ヨウ化第一銅、シアン 化第一銅、酸化第一銅、過塩素酸第一銅などを挙げることができる。銅化合物を用 いる場合、触媒活性を高めるために、 2, 2' —ビビリジルおよびその誘導体、 1, 10 —フエナント口リンおよびその誘導体、テトラメチルエチレンジァミン (TMEDA)、ぺ ンタメチルジェチレントリァミン、へキサメチル（2—アミノエチル）ァミンなどのポリアミ ンなどを配位子として添加することもできる。また、 2価の塩化ルテニウムのトリストリフ ェ-ルホスフィン錯体 (RuCl (PPh ) )も触媒として使用できる。ルテニウム化合物を [0114] The transition metal complex used as the catalyst for the atom transfer radical polymerization is not particularly limited, but preferred are monovalent and zerovalent copper complexes, divalent ruthenium complexes, and divalent iron. And divalent nickel complexes. Among these, a copper complex is preferable from the viewpoint of cost and reaction control. [0115] Examples of monovalent copper compounds include cuprous chloride, cuprous bromide, cuprous iodide, cuprous cyanide, cuprous oxide, cuprous perchlorate, and the like. be able to. When copper compounds are used, 2, 2'-bibilidyl and its derivatives, 1, 10-phenantorin and its derivatives, tetramethylethylenediamine (TMEDA), pentamethylethylen Polyamines such as lyamine and hexamethyl (2-aminoethyl) amine can also be added as ligands. Divalent ruthenium chloride tristophosphine phosphine complex (RuCl (PPh)) can also be used as a catalyst. Ruthenium compounds
2 3 3  2 3 3
触媒として用いる場合は、活性化剤としてアルミニウムアルコキシド類を添加すること もできる。更に、 2価の鉄のビストリフエ-ルホスフィン錯体（FeCl (PPh ) )、 2価の- When used as a catalyst, aluminum alkoxides can also be added as an activator. Furthermore, divalent iron bistriphenylphosphine complex (FeCl (PPh)), divalent-
2 3 2 ッケルのビストリフエ-ルホスフィン錯体（NiCl (PPh ) )、および、 2価のニッケルの 2 3 2 Neckel bistriphenylphosphine complex (NiCl (PPh)) and divalent nickel
2 3 2  2 3 2
ビストリブチルホスフィン錯体 (NiBr (PBu ) )も触媒として使用できる。使用する触  Bistributylphosphine complex (NiBr (PBu)) can also be used as a catalyst. Touch to use
2 3 2  2 3 2
媒、配位子および活性化剤の量は、特に限定されないが、使用する開始剤、単量体 および溶媒の量と必要とする反応速度の関係から適宜決定できる。  The amounts of the medium, the ligand and the activator are not particularly limited, but can be appropriately determined from the relationship between the amount of the initiator, the monomer and the solvent used and the required reaction rate.
[0116] 前記原子移動ラジカル重合は、無溶媒 (塊状重合)で行うこともできるし、また各種 溶媒中で行なうこともできる。前記溶媒としては、例えば、 [0116] The atom transfer radical polymerization can be carried out without solvent (bulk polymerization) or in various solvents. As the solvent, for example,
ベンゼン、トルエンなどの炭化水素系溶媒；  Hydrocarbon solvents such as benzene and toluene;
塩化メチレン、クロ口ホルムなどのハロゲン化炭化水素系溶媒；  Halogenated hydrocarbon solvents such as methylene chloride and black mouth form;
アセトン、メチルェチルケトン、メチルイソブチルケトンなどのケトン系溶媒； メタノール、エタノール、プロパノール、イソプロパノール、 n—ブタノール、 tーブタノ ールなどのアルコール系溶媒；  Ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; alcohol solvents such as methanol, ethanol, propanol, isopropanol, n-butanol, and t-butanol;
ァセトニトリル、プロピオ-トリル、ベンゾ-トリルなどの-トリル系溶媒；  -Tolyl-based solvents such as acetonitrile, propio-tolyl, benzo-tolyl;
酢酸ェチル、酢酸ブチルなどのエステル系溶媒；  Ester solvents such as ethyl acetate and butyl acetate;
エチレンカーボネート、プロピレンカーボネートなどのカーボネート系溶媒； などをあげることができる。また、これらの溶媒は、 2種以上を混合して用いることが できる。溶媒を使用する場合、その使用量は、反応系全体の粘度と、必要とする反応 速度 (即ち、撹拌効率)の関係から適宜決定できる。  And carbonate solvents such as ethylene carbonate and propylene carbonate. These solvents can be used in a mixture of two or more. When a solvent is used, the amount used can be appropriately determined from the relationship between the viscosity of the entire reaction system and the required reaction rate (ie, stirring efficiency).
[0117] また、前記原子移動ラジカル重合は、好ましくは室温〜 200°C、より好ましくは 50〜 [0117] The atom transfer radical polymerization is preferably performed at room temperature to 200 ° C, more preferably 50 to
150°Cの範囲の温度で行なわれる。前記原子移動ラジカル重合温度が室温より低 、 と、反応系の粘度が高くなり過ぎて反応速度が遅くなることがあり、 200°Cを超えると、 安価な重合溶媒を使用できな ヽことがある。 Performed at a temperature in the range of 150 ° C. The atom transfer radical polymerization temperature is lower than room temperature, When the temperature exceeds 200 ° C, an inexpensive polymerization solvent may not be used.
[0118] 前記原子移動ラジカル重合により、アクリル系ブロック共重合体 (A)を製造する方 法としては、単量体を逐次添加する方法、あらかじめ合成した重合体を高分子開始 剤として次のブロックを重合する方法、別々に重合した重合体を反応により結合する 方法などが挙げられる。これらの方法は、目的に応じて使い分けることができる。製造 工程の簡便性の点からは、単量体の逐次添加による方法が好ましい。  [0118] As a method for producing the acrylic block copolymer (A) by the atom transfer radical polymerization, a method of sequentially adding monomers, a polymer synthesized in advance as a polymer initiator, and the next block And a method of polymerizing separately polymerized polymers by reaction. These methods can be used properly according to the purpose. From the viewpoint of simplicity of the production process, a method by sequential addition of monomers is preferred.
[0119] 次に、アクリル系ブロック共重合体 (A)に、酸無水物基を含有する単位 (cl)および Zまたはカルボキシル基を含有する単位 (c2)カゝらなる単位 (c)を導入する方法を以 下に示す。  [0119] Next, a unit (cl) containing an acid anhydride group and a unit (c2) containing Z or a carboxyl group (c) are introduced into the acrylic block copolymer (A). The following shows how to do this.
[0120] 酸無水物基を含有する単位 (cl)の導入方法としては、特に限定はないが、酸無水 物基の前駆体となる基を含有する単位をブロック共重合体に導入し、そののち、環化 させることが好ましい。以下に、その方法の詳細を説明する。  [0120] The method for introducing the unit (cl) containing an acid anhydride group is not particularly limited, but a unit containing a group that is a precursor of an acid anhydride group is introduced into the block copolymer, and It is preferable to cyclize afterwards. Details of the method will be described below.
[0121] 下記、一般式（2) :  [0121] The following general formula (2):
[化 4]  [Chemical 4]
Figure imgf000042_0001
Figure imgf000042_0001
(式中、 R2は水素原子またはメチル基、 R3は水素原子、メチル基またはフ -ル基を 表わし、少なくとも 1個のメチル基を含むこと以外は互いに同一でも異なっていてもよ い。）で表わされる単位を少なくとも 1個有するブロック共重合体、即ちアクリル系重合 体ブロック (a)を構成するアクリル酸エステルとして、下記に例示した単量体を用いた ブロック共重合体 (A)または該共重合体ブロック (A)を含む組成物を、好ましくは 18 0〜300°Cの温度で、溶融混練して環化させることにより導入できる。混練時の温度 力 S 180°Cより低いと、酸無水物基の生成が不充分となることがあり、 300°Cより高くな ると、アクリル系ブロック共重合体 (A)自体が分解することがある。 (In the formula, R 2 represents a hydrogen atom or a methyl group, R 3 represents a hydrogen atom, a methyl group or a full group, and may be the same or different from each other except that it contains at least one methyl group. The block copolymer (A) using the monomer exemplified below as a block copolymer having at least one unit represented by the following formula, that is, the acrylic ester constituting the acrylic polymer block ( a ): The composition containing the copolymer block (A) is preferably 18 It can be introduced by melt-kneading and cyclization at a temperature of 0 to 300 ° C. Kneading temperature Force S When the temperature is lower than 180 ° C, the acid anhydride group may be insufficiently formed. When the temperature is higher than 300 ° C, the acrylic block copolymer (A) itself decomposes. Sometimes.
[0122] 一般式 (2)で表わされる単位は、高温下で、隣接するエステルユニットと脱離、環化 し、例えば 6員環酸無水物基を生成する（例えば、畑田（Hatada)ら、ジエイ ェム エス ピュア アプライド ケミストリイ (J. M. S. PURE APPL. CHEM. ) , A30 (9 & 10) , PP. 645— 667 (1993)参照）。一般的に、エステルユニットが嵩高ぐ β 水素を有する重合体は、高温下でエステルユニットが分解してカルボキシル基を生 成し、引き続き環化が起こり、例えば 6員環などの酸無水物基が生成する。これらの 方法を利用することにより、アクリル系ブロック共重合体 (Α)中に、容易に酸無水物基 を導入できる。一般式（2)で表わされる単位を構成する単量体の具体的な例としては 、アクリル酸 tーブチル、アクリル酸イソプロピル、アクリル酸お aージメチルベンジ ル、アクリル酸 α メチルベンジル、メタアクリル酸 tーブチル、メタアクリル酸イソプロ ピル、メタアクリル酸 α , ージメチルベンジル、メタアクリル酸 α メチルベンジルな どが挙げられる力 これらに限定されない。これらのなかでも、入手のしゃすさや重合 容易性、酸無水物基の生成容易性などの点から、アクリル酸 t プチル、メタアクリル 酸 t ブチルが好ましい。  [0122] The unit represented by the general formula (2) is eliminated and cyclized with an adjacent ester unit at a high temperature to generate, for example, a 6-membered cyclic acid anhydride group (for example, Hatada et al., (See JAM PURE APPL. CHEM., A30 (9 & 10), PP. 645-667 (1993)). In general, a polymer having β hydrogen in which the ester unit is bulky, the ester unit decomposes at a high temperature to generate a carboxyl group, followed by cyclization, for example, an acid anhydride group such as a 6-membered ring. Generate. By using these methods, an acid anhydride group can be easily introduced into the acrylic block copolymer (Α). Specific examples of the monomer constituting the unit represented by the general formula (2) include t-butyl acrylate, isopropyl acrylate, a-dimethyl benzyl acrylate, α-methylbenzyl acrylate, and t-butyl methacrylate. , Isopropyl methacrylate, α-dimethylbenzyl methacrylate, α-methylbenzyl methacrylate, and the like, but are not limited thereto. Of these, t-butyl acrylate and t-butyl methacrylate are preferred from the viewpoints of availability, ease of polymerization, and ease of formation of acid anhydride groups.
[0123] カルボキシル基を含有する単位 (c2)の導入には、 V、ろ 、ろな方法が適用でき、特 に限定されないが、上記アクリル系ブロック共重合体への酸無水物基を含有する単 位 (cl)の導入の過程で、前記一般式（2)で表わされる単位の種類や含有量に応じ て、加熱温度や時間を適宜調整することにより、カルボキシル基を含有する単位 (c2 )生成させることが好ましい。これは、アクリル系ブロック共重合体 (A)の反応点の制 御や、アクリル系ブロック共重合体 (A)へのカルボキシル基を含有する単位 (c2)の 導入が容易だ力 である。  [0123] For the introduction of the carboxyl group-containing unit (c2), V, R, and R methods can be applied, and the method is not particularly limited. However, it contains an acid anhydride group to the acrylic block copolymer. In the process of introducing the unit (cl), by appropriately adjusting the heating temperature and time according to the type and content of the unit represented by the general formula (2), the unit containing a carboxyl group (c2) Preferably, it is generated. This is a force that allows easy control of the reaction point of the acrylic block copolymer (A) and introduction of the carboxyl group-containing unit (c2) into the acrylic block copolymer (A).
[0124] 従って、上記導入方法の観点からは、カルボキシル基を含有する単位 (c2)は、酸 無水物基を含有する単位 (cl)を含有するブロックと同じブロックに含有することが好 まし。また、耐熱性や凝集力の点からは、メタアクリル系重合体ブロック (b)に含有す ることがより好ましい。それは、ハードセグメントであるメタアクリル系重合体ブロック（b )に、ガラス転移温度 (Tg)や凝集力の高!ヽカルボキシル基を有する単位 (c2)を導 入することで、高温においてよりゴム弾性を発現することが可能となるからである。一 方、アクリル系重合体ブロック（a)にカルボキシル基を有する単位 (c2)が含有される と、相溶化剤 (C)との相溶性の点力も好ましい。 [0124] Therefore, from the viewpoint of the introduction method described above, the unit (c2) containing a carboxyl group is preferably contained in the same block as the block containing a unit (cl) containing an acid anhydride group. Further, from the viewpoint of heat resistance and cohesive strength, it is more preferable to contain it in the methacrylic polymer block (b). It is a methacrylic polymer block (b This is because, by introducing the glass transition temperature (Tg) and the unit (c2) having a high cohesive force and a carboxyl group into the resin, it becomes possible to exhibit more rubber elasticity at a high temperature. On the other hand, when the acrylic polymer block (a) contains the carboxyl group-containing unit (c2), the compatibility point with the compatibilizer (C) is also preferable.
[0125] 次に、熱可塑性エラストマ一組成物中の（B)ォレフィン系熱可塑性エラストマ一に ついて説明する。ォレフィン系熱可塑性エラストマ一（B)は、特に限定されないが、 熱可塑性ポリオレフインホモポリマーまたはコポリマーからなるポリオレフイン類と、完 全に架橋されている力 部分的に架橋されているォレフィン系ゴムまたはアタリ口-ト リル 'ブタジエンゴム (NBR)との組合せ力もなるものが好ましい。  [0125] Next, the (B) olefin-based thermoplastic elastomer in the thermoplastic elastomer composition will be described. The olefin-based thermoplastic elastomer (B) is not particularly limited, but the polyolefins made of thermoplastic polyolefin homopolymer or copolymer, and a completely cross-linked force. -It is preferable that it has a combination force with trill 'butadiene rubber (NBR).
[0126] 前記ポリオレフイン類は、熱可塑性であり、結晶質ポリオレフインホモポリマーおよび コポリマーが含まれる。中でもポリプロピレンを主成分とするものが好ましぐ低温特性 を良くするため、ポリプロピレンにエチレンが含まれるコポリマーが更に好ましい。  [0126] The polyolefins are thermoplastic and include crystalline polyolefin homopolymers and copolymers. Among them, a copolymer containing ethylene in polypropylene is more preferable in order to improve the low-temperature characteristics preferred by those having polypropylene as a main component.
[0127] 前記ォレフィン系ゴムとしては、低温特性が優れるエチレン 'プロピレンゴムおよび 非共役ジェンのターポリマーである EPDMゴムが好ましぐォレフィン系榭脂中で EP DMゴムを動的に架橋したものが特に好ましい。ォレフィン系榭脂中で EPDMゴムを 動的に架橋させることにより、少量のォレフィン系榭脂に EPDMゴムを均一分散させ ることができるため、熱可塑性を有しながら、圧縮耐久歪などの非常に優れたゴム特 性を発現できる。  [0127] Examples of the olefinic rubber include those obtained by dynamically cross-linking EPDM rubber in olefinic resin, which is preferably ethylene propylene rubber having excellent low-temperature characteristics and EPDM rubber which is a terpolymer of non-conjugated gen. Particularly preferred. By dynamically cross-linking the EPDM rubber in the polyolefin resin, the EPDM rubber can be uniformly dispersed in a small amount of the polyolefin resin. Excellent rubber properties can be expressed.
[0128] また、ォレフィン系熱可塑性エラストマ一（B)としては、 23°Cのショァ A硬度が 50〜 90、特に 65〜85のものが好ましい。このようなォレフィン系熱可塑性エラストマ一は 、例えばサントプレン、 GEOLAST (いずれもアドバンスドエラストマーズ社製）などの 商品名で市販されており、巿場力 容易に入手できる。  [0128] The olefin-based thermoplastic elastomer (B) preferably has a Shore A hardness of 50 to 90, particularly 65 to 85 at 23 ° C. Such olefin-based thermoplastic elastomers are commercially available under trade names such as Santoprene and GEOLAST (both manufactured by Advanced Elastomers), and are easily available.
[0129] 更に、熱可塑性エラストマ一組成物中の相溶化剤 (C)としては、特に限定されない 力 アクリル系ブロック共重合体 (A)とォレフイン系熱可塑性エラストマ一（B)をより良 好に相溶ィ匕させるため、アクリル系ブロック共重合体 (A)のポリメタアクリル酸無水物 などの単位 (c)と反応するエポキシ基を含有するォレフイン系熱可塑性榭脂 (変性ポ リオレフイン）が好ましい。例えば、市販で入手可能な、エチレンとグリシジルメタアタリ レートとの共重合体、あるいはメチルアタリレートを有するエチレンとグリシジルメタァク リレート、グリシジルメタアタリレートをグラフトしたポリプロピレンなどが例示される。こ れらの変性ポリオレフイン榭脂中のグリシジルメタタリレートの含有量は、好ましくは 0. 05重量％〜50重量％であり、より好ましくは 0. 1重量％〜20重量％である。グリシ ジルメタタリレートの含有量が 0. 05重量％より少ない場合、アクリル系ブロック共重合 体 (A)とォレフイン系熱可塑性エラストマ一 (B)の相溶性が充分でなくなり、引張強 度などが悪ィ匕することがある。グリシジルメタタリレートの含有量が 50重量％より多い と、アクリル系ブロック共重合体 (A)とォレフイン系熱可塑性エラストマ一（B)の凝集 性が強くなりすぎて、引張伸びが低下することがある。これらの変性ポリオレフイン榭 脂は、例えば市販されている商品名のボンドファースト (住友ィ匕学工業 (株)製)、モ ディパー（日本油脂 (株)製)などであり、市場から容易に入手できる。 [0129] Further, the compatibilizing agent (C) in the thermoplastic elastomer composition is not particularly limited. The acrylic block copolymer (A) and the olefin thermoplastic elastomer (B) are more preferably used. For compatibility, an olefin thermoplastic resin (modified polyolefin) containing an epoxy group that reacts with the unit (c) such as polymethacrylic anhydride of the acrylic block copolymer (A) is preferable. . For example, commercially available copolymers of ethylene and glycidyl methacrylate or ethylene and glycidyl methacrylate having methyl acrylate. Examples thereof include polypropylene grafted with relate and glycidyl metaatarylate. The content of glycidyl metatalylate in these modified polyolefin resins is preferably 0.05% to 50% by weight, more preferably 0.1% to 20% by weight. If the glycidyl methacrylate content is less than 0.05% by weight, the compatibility between the acrylic block copolymer (A) and the olefin thermoplastic elastomer (B) is insufficient, and the tensile strength is increased. There is something wrong. If the content of glycidyl metatalylate is more than 50% by weight, the cohesiveness of the acrylic block copolymer (A) and the olefin thermoplastic elastomer (B) becomes too strong and the tensile elongation may decrease. is there. These modified polyolefin resins are, for example, commercially available product names such as Bond First (manufactured by Sumitomo Chemical Co., Ltd.), Modiper (manufactured by Nippon Oil & Fats Co., Ltd.), and can be easily obtained from the market. .
[0130] 本発明で使用する熱可塑性エラストマ一組成物としては、（A)アクリル系ブロック共 重合体と（B)ォレフィン系熱可塑性エラストマ一を含むもの、更には前記 (A)と (B)に 加えて (C)相溶化剤を含むものが好適である。例えば、アクリル系ブロック共重合体（ A) 100重量部に対し、ォレフィン系熱可塑性エラストマ一（B) 50〜600重量部、より 好ましくは 200〜600重量部、更に好ましくは 400重量部、（C)相溶化剤 5〜50重量 部からなるものが好ましい。前記 (A)〜（C)のそれぞれの含有量力 上記範囲内に あることで、耐熱性、耐油性に優れ、射出成形で寸法性の良い成形体を得ることがで き、自動車用等速ジョイント用ブーツなどを製造する場合に特に好ましい。  [0130] The thermoplastic elastomer composition used in the present invention includes (A) an acrylic block copolymer and (B) an olefin-based thermoplastic elastomer, and further (A) and (B). In addition, (C) those containing a compatibilizer are suitable. For example, for 100 parts by weight of the acrylic block copolymer (A), the olefin-based thermoplastic elastomer (B) is 50 to 600 parts by weight, more preferably 200 to 600 parts by weight, still more preferably 400 parts by weight, (C ) Compatibilizers consisting of 5 to 50 parts by weight are preferred. Content power of each of the above (A) to (C) By being within the above range, a molded article having excellent heat resistance and oil resistance and good dimensionality by injection molding can be obtained. It is particularly preferable when manufacturing boots for manufacturing.
[0131] この熱可塑性エラストマ一組成物は、成形加工するに際して、アクリル系ブロック共 重合体 (A)、ォレフィン系熱可塑性エラストマ一 (B)、相溶化剤 (C)をそれぞれ計量 し、成形カ卩工機に投入しても良いが、ハンドリング、混練の均一性などの観点から、 成形カ卩ェ前にペレツトイ匕しておくことが好ましい。熱可塑性エラストマ一組成物をペレ ット化する方法は、特に限定されないが、バンバリ一ミキサー、ロールミル、ニーダー、 単軸または多軸の押出機などの公知の装置を用い、適当な温度で加熱しながら機 械的に混練することで、ペレット状に賦形することができる。混練時の温度は、使用す るアクリル系ブロック共重合体 (A)、ォレフィン系熱可塑性エラストマ一（B)、相溶ィ匕 剤（C)の溶融温度などに応じて調整すればよぐ例えば 180〜300°Cである。  [0131] This thermoplastic elastomer composition was prepared by measuring the acrylic block copolymer (A), the olefin thermoplastic elastomer (B), and the compatibilizer (C) during molding. Although it may be put into a machine, it is preferable to pelletize before molding molding from the viewpoint of handling and uniformity of kneading. The method of pelletizing the thermoplastic elastomer composition is not particularly limited, and is heated at an appropriate temperature using a known apparatus such as a Banbury mixer, roll mill, kneader, single-screw or multi-screw extruder. However, it can be shaped into pellets by mechanically kneading. The temperature at the time of kneading may be adjusted according to the melting temperature of the acrylic block copolymer (A), the olefin-based thermoplastic elastomer (B), the compatible solvent (C) used, for example. 180-300 ° C.
[0132] また、低温特性が要求される成形品の場合は、熱可塑性エラストマー榭脂として、 アクリル系ブロック共重合体 (A)とポリオルガノシロキサン系グラフト重合体 (D)力もな る組成物を使用することが好ましい。更に高温での弾性率が要求される場合、アタリ ル系ブロック共重合体 (A)、ポリオルガノシロキサン系グラフト重合体 (D)、熱可塑性 榭脂、滑剤および無機充填剤カゝらなる組成物を使用することが好まし ヽ。 [0132] In the case of a molded product requiring low-temperature characteristics, as thermoplastic elastomer resin, It is preferable to use a composition that also has an acrylic block copolymer (A) and a polyorganosiloxane graft polymer (D). In the case where higher modulus of elasticity is required, a composition comprising an talyl block copolymer (A), a polyorganosiloxane graft polymer (D), a thermoplastic resin, a lubricant, and an inorganic filler. Is preferred to use ヽ.
[0133] 前記ポリオルガノシロキサン系グラフト重合体 (D)は、その組成などに特に限定は ないが、ポリオルガノシロキサン（dl) 40〜95重量％の存在下に、単量体（d2)を 0〜 10重量％重合し、更にビニル系単量体（d3)を 5〜60重量％[ (dl)、 （d2)および（d 3)合わせて 100重量％]を重合した共重合体が好ましい。前記単量体 (d2)は、分子 内に重合性不飽和結合を 2つ以上含む多官能性単量体 (X) 50〜： LOO重量％、およ び、その他の共重合可能なビュル系単量体 (y) 0〜50重量％からなる単量体である 。更には、単量体 (d2)とビュル系単量体 (d3)をあわせたグラフト成分の含有量が 5 〜40重量％で、ポリオルガノシロキサンの含有量が 95〜60重量％であることが好ま しい。 [0133] The composition of the polyorganosiloxane-based graft polymer (D) is not particularly limited, but the monomer (d2) is added in the presence of 40 to 95% by weight of the polyorganosiloxane (dl). A copolymer obtained by polymerizing ˜10% by weight and further polymerizing 5 to 60% by weight of vinyl monomer (d3) [100% by weight in total of (dl), (d2) and (d3)] is preferable. The monomer (d2) is a polyfunctional monomer (X) having two or more polymerizable unsaturated bonds in the molecule 50 to: LOO wt%, and other copolymerizable bur system Monomer (y) A monomer composed of 0 to 50% by weight. Furthermore, the content of the graft component including the monomer (d2) and the bull monomer (d3) is 5 to 40% by weight, and the polyorganosiloxane content is 95 to 60% by weight. I like it.
[0134] 前記アクリル系ブロック共重合体 (A)とポリオルガノシロキサン系グラフト重合体 (D )からなる熱可塑性エラストマー榭脂には、高温時の弾性率を高めるために、滑剤、 無機充填剤および熱可塑性榭脂を配合することができる。各成分の配合量は、アタリ ル系ブロック共重合体 (A) 100重量部に対して、ポリオルガノシロキサン系グラフト重 合体 (D) 10〜： LOO重量部、滑剤 0. 1〜10重量部、無機充填剤 0. 1〜： L00重量部、 熱可塑性榭脂 0. 1〜： L00重量部が好ましい範囲である。  [0134] The thermoplastic elastomer resin comprising the acrylic block copolymer (A) and the polyorganosiloxane graft polymer (D) has a lubricant, an inorganic filler, and an Thermoplastic rosin can be blended. The blending amount of each component is 10 parts by weight of the polyorganosiloxane graft polymer (D) with respect to 100 parts by weight of the talyl block copolymer (A): LOO parts by weight, 0.1 to 10 parts by weight of the lubricant, Inorganic fillers 0.1 to L00 parts by weight, thermoplastic resin 0.1 to L00 parts by weight are preferable ranges.
[0135] 前記滑剤としては、例えば、ステアリン酸、パルミチン酸などの脂肪酸、ステアリン酸 カルシウム、ステアリン酸亜鉛、ステアリン酸マグネシウム、パルミチン酸カリウム、ノ ルミチン酸ナトリウムなどの脂肪酸金属塩、ポリエチレンワックス、ポリプロピレンヮック ス、モンタン酸系ワックスなどのワックス類、低分子量ポリエチレンや低分子量ポリプロ ピレンなどの低分子量ポリオレフイン、ジメチルポリシロキサンなどのポリオルガノシロ キサン、ククタデシルァミン、リン酸アルキル、脂肪酸エステル、エチレンビスステア口 アミドなどのアミド系滑剤、 4—フッ化工チレン榭脂などのフッ素榭脂粉末、二硫化モ リブデン粉末、シリコーン榭脂粉末、シリコーンゴム粉末、シリカなどが挙げられるが、 これらに限定されるものではない。これらは単独で使用してもよぐ 2種以上を組み合 わせて使用してもよい。なかでも榭脂表面の低摩擦性、加工性に優れた点から、ステ アリン酸、ステアリン酸亜鉛、ステアリン酸カルシウム、ステアリン酸マグネシウム、ステ ァリルアミドが好ましい。 [0135] Examples of the lubricant include fatty acids such as stearic acid and palmitic acid, fatty acid metal salts such as calcium stearate, zinc stearate, magnesium stearate, potassium palmitate and sodium normitate, polyethylene wax, and polypropylene wax. Waxes such as waxes, montanic acid waxes, low molecular weight polyolefins such as low molecular weight polyethylene and low molecular weight polypropylene, polyorganosiloxanes such as dimethylpolysiloxane, octadecylamine, alkyl phosphates, fatty acid esters, ethylene Examples include, but are not limited to, amide-based lubricants such as bis-stear mouth amide, fluorine resin powders such as 4-fluorinated styrene resin, molybdenum disulfide powder, silicone resin powder, silicone rubber powder, and silica. Ru Not to. These can be used alone or in combination of two or more You may use it. Of these, stearic acid, zinc stearate, calcium stearate, magnesium stearate, and stearamide are preferred from the viewpoint of low friction and excellent workability on the surface of the resin.
[0136] 前記無機充填剤としては、例えば、酸化チタン、硫化亜鉛、酸化亜鉛、カーボンブ ラック、炭酸カルシウム、ケィ酸カルシウム、クレー、カオリン、シリカ、雲母粉、アルミ ナ、ガラス繊維、金属繊維、チタン酸力リウイスカー、アスベスト、ウォラストナイト、マイ 力、タルク、ガラスフレーク、ミルドファイバー、金属粉末などが挙げられる力 これらに 限定されない。これらは単独で使用してもよく、 1種以上を組み合せて使用してもよい 。なかでも高弾性率の点からはシリカが好ましぐまた耐候性と、顔料としても用いるこ とができる点ではカーボンブラックや酸ィ匕チタンが好ましい。  [0136] Examples of the inorganic filler include titanium oxide, zinc sulfide, zinc oxide, carbon black, calcium carbonate, calcium silicate, clay, kaolin, silica, mica powder, alumina, glass fiber, metal fiber, and titanium. Forces including, but not limited to, acid-powered whisker, asbestos, wollastonite, my strength, talc, glass flakes, milled fiber, metal powder, and the like. These may be used alone or in combination of one or more. Of these, silica is preferred from the viewpoint of high elastic modulus, and weather resistance and carbon black and titanium oxide are preferred from the viewpoint that they can be used as pigments.
[0137] 前記熱可塑性榭脂としては、例えばポリ塩ィ匕ビュル系榭脂、ポリエチレン系榭脂、 ポリプロピレン系榭脂、環状ォレフィン共重合榭脂、ポリメチルメタタリレート系榭脂、 ポリスチレン系榭脂、ポリフエ二レンエーテル系榭脂、ポリカーボネート系榭脂、ポリエ ステル系榭脂、ポリアミド系榭脂、ポリアセタール榭脂、ポリフエ-レンスルフイド榭脂 、ポリスルホン樹脂、ポリイミド榭脂、ポリエーテルイミド榭脂、ポリエーテルケトン樹脂 、ポリエーテルエーテルケトン樹脂、ポリアミドイミド榭脂およびイミドィ匕ポリメチルメタク リレート榭脂などが挙げられる。これらは単独で使用してもよく 2種以上を組み合わせ て使用してもよい。これらのうちでは、アクリル系ブロック共重合体 (A)と相溶性のよい ものが好適に用いられ、酸無水物基と反応し得る官能基を有するものがより好適に用 いられる。酸無水物基と反応し得る官能基としては、アミノ基、水酸基などが例示され 、これらを有する熱可塑性榭脂としては、ポリエステル系榭脂、ポリアミド系榭脂など が挙げられる。これら以外の、酸無水物基と反応する官能基を含有する熱可塑性榭 脂も好適に使用できる。  [0137] Examples of the thermoplastic resin include polysalt resin resin, polyethylene resin, polypropylene resin, cyclic olefin copolymer resin, polymethylmetatalate resin, polystyrene resin Resin, polyphenylene ether resin, polycarbonate resin, polyester resin, polyamide resin, polyacetal resin, polyphenylene sulfide resin, polysulfone resin, polyimide resin, polyetherimide resin, poly Examples include ether ketone resins, polyether ether ketone resins, polyamide imide resins and imido polymethyl methacrylate resins. These may be used alone or in combination of two or more. Of these, those having good compatibility with the acrylic block copolymer (A) are preferably used, and those having a functional group capable of reacting with an acid anhydride group are more preferably used. Examples of the functional group capable of reacting with the acid anhydride group include an amino group and a hydroxyl group. Examples of the thermoplastic resin having these include polyester-based resins and polyamide-based resins. Other than these, a thermoplastic resin containing a functional group that reacts with an acid anhydride group can also be suitably used.
[0138] また、本発明で使用される熱可塑性エラストマー榭脂には、必要特性に応じて、安 定剤 (老化防止剤、光安定剤、紫外線吸収剤など)、柔軟性付与剤、難燃剤、離型 剤、帯電防止剤、抗菌抗カビ剤などを添加してもよい。これらの添加剤は、必要とさ れる物性や、カ卩ェ性などに応じて、適宜適したものを選択して使用すればよい。  [0138] The thermoplastic elastomer resin used in the present invention has a stabilizer (an anti-aging agent, a light stabilizer, an ultraviolet absorber, etc.), a flexibility imparting agent, and a flame retardant according to necessary characteristics. Further, a release agent, an antistatic agent, an antibacterial antifungal agent and the like may be added. These additives may be appropriately selected and used according to the required physical properties, cache properties and the like.
[0139] 前記安定剤 (老化防止剤、光安定剤、紫外線吸収剤など)としては、以下の化合物 が挙げられるが、これらに限定されない。 [0139] Examples of the stabilizer (anti-aging agent, light stabilizer, ultraviolet absorber, etc.) include the following compounds: However, it is not limited to these.
[0140] 老化防止剤としては、フエ-ル a ナフチルァミン（PAN)、ォクチルジフエ-ルアミ ン、 N, N' —ジフエ-ルー p フエ-レンジァミン（DPPD)、 N, N' —ジー β—ナ フチル ρ フエ-レンジァミン（DNPD)、N— (1, 3 ジメチル—ブチル）— N' - フエ二ノレ一 p フエ-レンジァミン、 N フエ二ノレ一 N' —イソプロピノレー p フエ-レ ンジァミン（IPPN)、 N, N' —ジァリノレー p フエ二レンジァミン、フエノチアジン誘導 体、ジァリル— p フエ-レンジァミン混合物、アルキル化フエ-レンジァミン、 4, 4' — a、 a—ジメチルベンジルジフエ-ルァミン、 p, p トルエンスルフォ-ルアミノジフ ェ-ルァミン、 N—フエ-ルー N' - (3—メタクリロイロキシ一 2 ヒドロプロピル） p —フエ-レンジァミン、ジァリルフエ-レンジァミン混合物、ジァリル一 p フエ-レンジ ァミン混合物、 N— (1—メチルヘプチル） N—フエ-ルー p フエ-レンジァミン、 ジフエ二ルァミン誘導体などのアミン系老化防止剤、 2—メルカプトべンゾイミダゾー ル（MBI)などのイミダゾール系老化防止剤、 2, 6 ジー tーブチルー 4 メチルフエ ノールなどのフエノール系老化防止剤、ニッケルジェチルージチォカーバメイトなど のリン酸塩系老化防止剤、トリフエ-ルホスフアイトなどの 2次老化防止剤などが挙げ られる。 [0140] Anti-aging agents include: phenol a naphthylamine (PAN), octyl diphenylamine, N, N '— diphenol-p p-dirangeamine (DPPD), N, N' — G β-naphthyl ρ Phenylenediamine (DNPD), N— (1,3 dimethyl-butyl) —N′-Phenenoleine p Phenylenediamine, N Phenolene N′—Isopropynole p-Phenylenediamine (IPPN), N , N '— Dianoleno p-phenylene diamine, phenothiazine derivative, diaryl-p phenylenediamine mixture, alkylated phenylenediamine, 4, 4' — a, a-dimethylbenzyldiphenylamine, p, p toluenesulfo -Luaminodiphenylamine, N—Phenol N ′-(3—Methacryloyloxy-2-hydropropyl) p —Phenoldiamine, Diarylphenol-Diamine mixture, Diaryl-1-Phenolamine mixture N- (1-Methylheptyl) N-Fe-Lu-Phenoldiamine, amine-based anti-aging agents such as diphenylamine derivatives, 2-imidazole anti-aging agents such as 2-mercaptobenzoimidazole (MBI), 2, Examples include phenolic anti-aging agents such as 6-tert-butyl-4-methylphenol, phosphate anti-aging agents such as nickel jetyl dithiocarbamate, and secondary anti-aging agents such as triphenylphosphite.
[0141] また、光安定剤や紫外線吸収剤としては、 4— t—ブチルフエ-ルサリシレート、 2, 4ージヒドロキシベンゾフエノン、 2, 2' ジヒドロキシー4ーメトキシベンゾフエノン、ェ チル一 2 シァノ 3, 3' —ジフエ-ルアタリレート、 2 ェチルへキシル 2 ジァ ノ一 3, 3' —ジフエ-ルアタリレート、 2 ヒドロキシ一 5 クロルべンゾフエノン、 2 ヒ ドロキシー4ーメトキシベンゾフエノンー2 ヒドロキシー4—オタトキシベンゾフエノン、 モノグリコールサリチレート、ォキザリック酸アミド、 2, 2' , 4, 4' —テトラヒドロキシべ ンゾフエノンなどが挙げられる。これら安定剤は単独で使用してもよぐ 2種以上を組 み合わせて使用してもよい。  [0141] Examples of light stabilizers and UV absorbers include 4-t-butylphenol salicylate, 2,4-dihydroxybenzophenone, 2,2 'dihydroxy-4-methoxybenzophenone, and ethyl 2- Cyan 3, 3 '— diphenyl attalylate, 2 ethylhexyl 2 di cyano 1, 3' — diphenyl acrylate, 2 hydroxy 1 5 chlorbenzophenone, 2 hydroxy 4-methoxybenzophenone 2 Hydroxy-4-octoxybenzophenone, monoglycol salicylate, oxalic acid amide, 2, 2 ', 4, 4'-tetrahydroxybenzophenone. These stabilizers may be used alone or in combination of two or more.
[0142] 柔軟性付与剤としては、例えば熱可塑性榭脂ゃゴムに通常配合される可塑剤、軟 ィ匕剤、オリゴマー、油分 (動物油、植物油など）、石油留分 (灯油、軽油、重油、ナフ サなど）などが挙げられる力 アクリル系ブロック共重合体 (A)、ォレフイン系熱可塑 性エラストマ一（B)、相溶化剤 (C)、ポリオルガノシロキサン系グラフト重合体 (D)との 親和性に優れたものを用いるのが好ましい。なかでも、低揮発性で加熱減量の少な い可塑剤であるアジピン酸誘導体、フタル酸誘導体、ダルタル酸誘導体、トリメリト酸 誘導体、ピロメリト酸誘導体、ポリエステル系可塑剤、グリセリン誘導体、エポキシ誘導 体ポリエステル系重合型可塑剤、ポリエーテル系重合型可塑剤などが好適に使用さ れる。 [0142] Examples of the flexibility-imparting agent include plasticizers, softeners, oligomers, oils (animal oil, vegetable oil, etc.), petroleum fractions (kerosene, light oil, heavy oil, Naphtha, etc.) with acrylic block copolymer (A), olefin thermoplastic elastomer (B), compatibilizer (C), polyorganosiloxane graft polymer (D) Those having excellent affinity are preferably used. Among these, low-volatile plasticizers with low heat loss are adipic acid derivatives, phthalic acid derivatives, dartaric acid derivatives, trimellitic acid derivatives, pyromellitic acid derivatives, polyester-based plasticizers, glycerin derivatives, epoxy-derived polyester-based polymerizations. A mold plasticizer, a polyether polymerization type plasticizer, and the like are preferably used.
[0143] 軟化剤としては、例えばパラフィン系オイル、ナフテン系プロセスオイル、芳香族系  [0143] Examples of the softener include paraffinic oil, naphthenic process oil, and aromatic series.
[0144] 可塑剤としては、例えばフタル酸ジメチル、フタル酸ジェチル、フタル酸ジ n—ブ チル、フタル酸ジ一（2—ェチルへキシル）、フタル酸ジヘプチル、フタル酸ジイソデ シル、フタル酸ジ n—ォクチル、フタル酸ジイソノエル、フタル酸ジトリデシル、フタ ル酸ォクチルデシル、フタル酸ブチルベンジル、フタル酸ジシクロへキシルなどのフ タル酸誘導体；ジメチルイソフタレートのようなイソフタル酸誘導体；ジー（2—ェチル へキシル)テトラヒドロフタル酸のようなテトラヒドロフタル酸誘導体；アジピン酸ジメチ ル、アジピン酸ジブチル、アジピン酸ジ n キシル、アジピン酸ジー（2—ェチル へキシル）、アジピン酸ジォクチル、アジピン酸イソノエル、アジピン酸ジイソデシル、 アジピン酸ジブチルジグリコールなどのアジピン酸誘導体；ァゼライン酸ジー 2—ェチ ルへキシルなどのァゼライン酸誘導体；セバシン酸ジブチルなどのセバシン酸誘導 体；ドデカン二酸誘導体；マレイン酸ジブチル、マレイン酸ジ 2—ェチルへキシルな どのマレイン酸誘導体；フマル酸ジブチルなどのフマル酸誘導体； p ォキシ安息香 酸 2 -ェチルへキシルなどの p -ォキシ安息香酸誘導体、トリメリト酸トリス— 2—ェチ ルへキシルなどのトリメリト酸誘導体；ピロメリト酸誘導体；タエン酸ァセチルトリブチル などのクェン酸誘導体;ィタコン酸誘導体;ォレイン酸誘導体；リシノール酸誘導体;ス テアリン酸誘導体；その他の脂肪酸誘導体；スルホン酸誘導体；リン酸誘導体；グルタ ル酸誘導体;アジピン酸、ァゼライン酸、フタル酸などの 2塩基酸とダリコールおよび 1 価アルコールなどとのポリマーであるポリエステル系可塑剤、ダルコール誘導体、グリ セリン誘導体、塩素化パラフィンなどのパラフィン誘導体、エポキシ誘導体ポリエステ ル系重合型可塑剤、ポリエーテル系重合型可塑剤、エチレンカーボネート、プロピレ ンカーボネートなどのカーボネート誘導体、 N ブチルベンゼンアミドなどのベンゼン スルホン酸誘導体などが挙げられる力 これらに限定されるものではなぐゴム用また は熱可塑性榭脂用可塑剤として広く市販されているものなどの種々の可塑剤を用い ることができる。市販されている可塑剤としては、チォコール TP (モートン社製）、アデ 力サイザ一 O— 130P、 C— 79、 UL— 100、 P— 200、 RS— 735 (旭電ィ匕工業 (株） 製)、サンソサイザ一 N— 400 (新日本理化 (株)製)、 BM— 4 (大八化学工業 (株)製 )、 EHPB (上野製薬 (株)製)、 UP— 1000 (東亞合成化学 (株)製)などが挙げられ る。 [0144] Examples of the plasticizer include dimethyl phthalate, jetyl phthalate, di-n-butyl phthalate, di- (2-ethylhexyl) phthalate, diheptyl phthalate, diisodecyl phthalate, di-n-phthalate. —Phthalic acid derivatives such as octyl, diisonoyl phthalate, ditridecyl phthalate, octyl decyl phthalate, butylbenzyl phthalate, dicyclohexyl phthalate; isophthalic acid derivatives such as dimethyl isophthalate; ) Tetrahydrophthalic acid derivatives such as tetrahydrophthalic acid; dimethyl adipate, dibutyl adipate, di-n-xyl adipate, di-ethyl adipate (2-ethylhexyl), dioctyl adipate, isonoid adipate, diisodecyl adipate, Adipates such as dibutyl diglycol adipate Acid derivatives; azelaic acid derivatives such as diazeylate di-2-ethylhexyl; sebacic acid derivatives such as dibutyl sebacate; dodecanedioic acid derivatives; maleic acid such as dibutyl maleate and di-2-ethylhexyl maleate Derivatives; fumaric acid derivatives such as dibutyl fumarate; p-oxybenzoic acid derivatives such as p-oxybenzoic acid 2-ethylhexyl, trimellitic acid derivatives such as tris-2-ethylhexyl trimellitic acid; pyromellitic acid derivatives; Cenoic acid derivatives such as acetylacetic tributyl taenoate; itaconic acid derivative; oleic acid derivative; ricinoleic acid derivative; stearic acid derivative; other fatty acid derivative; sulfonic acid derivative; phosphoric acid derivative; glutaric acid derivative; Dibasic acids such as acid and phthalic acid, Daricol and monohydric alcohol Polyester plasticizers, darcol derivatives, glycerin derivatives, paraffin derivatives such as chlorinated paraffins, epoxy derivatives polyester polymerization plasticizers, polyether polymerization plasticizers, ethylene carbonate, propylene carbonate Carbonate derivatives such as N, benzene such as butylbenzeneamide Forces including sulfonic acid derivatives, etc. Various plasticizers such as those widely marketed as rubber or thermoplastic resin plasticizers can be used. Commercially available plasticizers include Thiokol TP (Morton), Ade force sizer O-130P, C-79, UL-100, P-200, RS-735 (Asahi Denshi Kogyo Co., Ltd.) ), Sansosaizer N-400 (manufactured by Shin Nippon Rika Co., Ltd.), BM—4 (manufactured by Daihachi Chemical Industry Co., Ltd.), EHPB (manufactured by Ueno Pharmaceutical Co., Ltd.), UP—1000 (Toagosei Chemical Co., Ltd.) ))).
[0145] 油分としては、例えばひまし油、綿実油、あまに油、なたね油、大豆油、パーム油、 やし油、落花生油、パインオイル、トール油、ゴマ油、ツバキ油などの植物油などが挙 げられる。  [0145] Examples of the oil include vegetable oils such as castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, pine oil, tall oil, sesame oil, camellia oil, and the like.
[0146] そのほかの柔軟性付与剤としては、ポリブテン系オイノレ、スピンドノレ油、マシン油、ト リクレジルホスフェートなどが挙げられる。  [0146] Examples of other flexibility-imparting agents include polybutene-based oils, spinned oils, machine oils, tricresyl phosphate, and the like.
[0147] 難燃剤としては、トリフエ-ルホスフェート、トリクレジルホスフェート、デカブ口モビフ ェニル、デカブロモビフエ-ルエーテル、三酸化アンチモンなどが挙げられる力 これ らに限定されない。これら難燃剤は単独で使用してもよぐ 2種以上を組み合わせて 使用してちょい。 [0147] Examples of the flame retardant include, but are not limited to, triphenyl phosphate, tricresyl phosphate, deca mouth mobile biphenyl, decabromobiphenyl ether, and antimony trioxide. These flame retardants may be used alone or in combination of two or more.
[0148] 本発明の榭脂製ブーツは、前記のような熱可塑性エラストマー榭脂を射出成形して 製造される。前記エラストマー榭脂から榭脂製ブーツを射出成形する際の条件として は、例えば、シリンダー温度： 150〜230°C、ノズル温度： 180〜240°C、射出速度： 低速、冷却時間： 30秒、金型温度： 30〜80°Cである。  [0148] The resin boots of the present invention are manufactured by injection molding the thermoplastic elastomer resin as described above. The conditions for injection molding of the resin-made boot from the elastomer resin are, for example, cylinder temperature: 150 to 230 ° C, nozzle temperature: 180 to 240 ° C, injection speed: low speed, cooling time: 30 seconds, Mold temperature: 30-80 ° C.
[0149] 本発明の射出成形法により製造された榭脂製ブーツは、優れた低温特性、耐油性 、耐熱性、耐候性、機械特性更には疲労強度などを有し、自動車用等速ジョイント用 ブーツなどに好適に使用することができる。また、本発明の榭脂製ブーツは、従来の 加硫ゴム系と比較して、成形工程が簡素化され、またリサイクル性に優れる。  [0149] The resin-made boots manufactured by the injection molding method of the present invention have excellent low-temperature characteristics, oil resistance, heat resistance, weather resistance, mechanical characteristics, fatigue strength, etc., and are used for constant velocity joints for automobiles. It can be suitably used for boots and the like. In addition, the resin-made boots of the present invention have a simplified molding process and excellent recyclability as compared with conventional vulcanized rubber systems.
実施例  Example
[0150] 以下に実施例を示し、本発明をより具体的に説明するが、本発明はこれらの実施 例に何ら限定されない。なお、以下の実施例の記載における、 BA、 MEA、 MMA、 TBMAは、それぞれアクリル酸 n—ブチル、アクリル酸 2—メトキシェチル、メタアタリ ル酸メチル、メタアクリル酸 t ブチルを意味する。 [0150] Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the description of the following examples, BA, MEA, MMA, and TBMA are n-butyl acrylate, 2-methoxyethyl acrylate, and methacrylate, respectively. Means methyl luate and t-butyl methacrylate.
[0151] (分子量の測定）  [0151] (Measurement of molecular weight)
アクリル系ブロック共重合体の分子量は、 GPC分析装置〔システム：ウォーターズ（ Waters)社製の GPCシステム、カラム：昭和電工 (株）製の Shodex K— 804 (ポリス チレンゲル）〕を用い、クロ口ホルムを移動相とし、ポリスチレン換算の分子量を求めた  The molecular weight of the acrylic block copolymer was determined using a GPC analyzer (system: GPC system manufactured by Waters, column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK). Was used as the mobile phase, and the molecular weight in terms of polystyrene was determined.
[0152] (6員環酸無水物基変換分析） [0152] (6-membered cyclic acid anhydride group conversion analysis)
アクリル系ブロック共重合体の 6員環酸無水物基変換反応の確認は、赤外スぺタト ル分析（(株）島津製作所製、 FTIR— 8100を使用）および核磁気共鳴分析 (BRUK ER社製、 AM400を使用）を用いて行なった。  Confirmation of 6-membered cyclic acid anhydride group conversion reaction of acrylic block copolymer was performed by infrared spectrum analysis (manufactured by Shimadzu Corporation, using FTIR-8100) and nuclear magnetic resonance analysis (BRUK ER) Manufactured by AM400).
核磁気共鳴分析用溶剤として、カルボン酸エステル構造のブロック体は、 6員環酸 無水物型構造のブロック体とともに、重クロ口ホルムを測定溶剤として分析を行なった  As a solvent for nuclear magnetic resonance analysis, the block body of carboxylic acid ester structure was analyzed together with the block body of 6-membered cyclic acid anhydride type structure and heavy chloroform as a measuring solvent.
[0153] <製造例 1：アクリル系ブロック共重合体の製造 > <Production Example 1: Production of acrylic block copolymer>
加熱冷却可能な攪拌機付反応機の重合容器 (容量： 500L)内を窒素置換したのち 、臭化銅 840. lg (5. 9mol)と、ァセトニトリル（窒素パブリングしたもの） 12Lを投入 した。 30分間 70°Cで加熱攪拌したのち、開始剤 2, 5 ジブロモアジピン酸ジェチル 421. 7g (l. 17mol)および BA 41. 4L (288. 9mol)、 MEA 18. 6L (144. 5m ol)をカ卩えた。 85°Cで加熱攪拌し、ジエチレントリァミン 0. 1L (0. 59mol)をカ卩えて重 合を開始した。  The inside of a polymerization vessel (capacity: 500 L) of a reactor equipped with a stirrer capable of heating and cooling was purged with nitrogen, and then charged with 840. lg (5.9 mol) of copper bromide and 12 L of acetonitrile (nitrogen published). After stirring for 30 minutes at 70 ° C, the initiators 2,5 getyl dibromoadipate 421.7 g (l. 17 mol) and BA 41.4 L (288.9 mol), MEA 18.6 L (144.5 mol) I was angry. The mixture was heated and stirred at 85 ° C., and 0.1 L (0.59 mol) of diethylenetriamine was added to start polymerization.
[0154] 重合開始から一定時間ごとに、重合溶液から重合溶液約 0. 2mlをサンプリングし、 サンプリング溶液のガスクロマトグラム分析により BAの転ィ匕率を決定した。ジエチレン トリアミンを随時カ卩えることで重合速度を制御した。 BAの転化率が 94%、 MEAの転 化率が 96%の時点で、 TBMA 24. 9L (153. 8mol)、 MMA 24. 7L (230. 8m ol)、塩ィ匕銅 580g (5. 9mol)、酢酸ブチル 1. 2L (9. lmol)およびトルエン（窒素バ ブリングしたもの） 122. 8Lを加えた。同様にして、 TBMA、 MMAの転化率を決定し た。 TBMAの転化率が 61%、 MMAの転化率が 56%の時点で、トルエン 80Lをカロ え、水浴で反応器を冷却して反応を終了させた。 [0155] 反応溶液をトルエン 115Lで希釈し、 p トルエンスルホン酸一水和物 1337gをカロ えて室温で 3時間撹拌したのち、ノ ッグフィルター（HAYWARD社製）を用いて固体 を除去した。得られたポリマー溶液に吸着剤（商品名キヨ一ワード 500SH、協和化学 (株)製)を 1642g加えて室温で更に 3時間撹拌し、ノ ッグフィルターを用い吸着剤を 濾過して無色透明のポリマー溶液を得た。この溶液を横型蒸発機 (伝熱面積 lm2)を 用いて乾燥させて溶剤および残存モノマーを除き、 目的のブロック共重合体を得た。 得られたブロック共重合体の GPC分析を行なったところ、数平均分子量 (Mn)が 93 700、分子量分布（MwZMn)が 1. 36であった。 [0154] About 0.2 ml of the polymerization solution was sampled from the polymerization solution at regular intervals from the start of the polymerization, and the conversion rate of BA was determined by gas chromatogram analysis of the sampling solution. The polymerization rate was controlled by adding diethylenetriamine as needed. When the conversion rate of BA is 94% and the conversion rate of MEA is 96%, TBMA 24.9 L (153.8 mol), MMA 24.7 L (230.8 mol), salted copper 580 g (5.9 mol) ), 1.2 L (9. lmol) of butyl acetate and 122.8 L of toluene (nitrogen bubbled). Similarly, the conversion rates of TBMA and MMA were determined. When the conversion rate of TBMA was 61% and the conversion rate of MMA was 56%, 80 L of toluene was added and the reactor was cooled in a water bath to complete the reaction. [0155] The reaction solution was diluted with 115 L of toluene, 1337 g of p-toluenesulfonic acid monohydrate was added and stirred at room temperature for 3 hours, and then the solid was removed using a Nog filter (manufactured by HAYWARD). Add 1642g of adsorbent (trade name Kiyo Ward 500SH, manufactured by Kyowa Chemical Co., Ltd.) to the polymer solution obtained, stir for another 3 hours at room temperature, and filter the adsorbent using a nogg filter to obtain a colorless and transparent polymer solution. Got. This solution was dried using a horizontal evaporator (heat transfer area lm 2 ) to remove the solvent and residual monomer, and the target block copolymer was obtained. As a result of GPC analysis of the obtained block copolymer, the number average molecular weight (Mn) was 93 700, and the molecular weight distribution (MwZMn) was 1.36.
[0156] 前記ブロック共重合体 700gとフエノール系酸化防止剤（商品名ィルガノックス 101 0、チバ'スペシャルティ'ケミカルズ (株)製） 1. 4gとを、 240°Cに設定した加圧-一 ダー（（株）モリヤマ製、 DS1— 5MHB— E型-一ダー）を用いて 70rpmで 20分間溶 融混練して、 目的の 6員環酸無水物基含有ブロック共重合体を得た。また、前記加圧 エーダーで得られた重合体の塊を、液体窒素と粉砕機により凍結粉砕して前記 6員 環酸無水物基含有ブロック共重合体のペレットを得た。  [0156] Pressure blocker set to 240 ° C with 700 g of the block copolymer and phenolic antioxidant (trade name: Irganox 1010, manufactured by Ciba 'Specialty' Chemicals Co., Ltd.) It was melt kneaded at 70 rpm for 20 minutes using a DS1-5MHB-E type-1 manufactured by Moriyama Co., Ltd. to obtain the target 6-membered cyclic acid anhydride group-containing block copolymer. In addition, the polymer mass obtained by the pressure ader was freeze-ground with liquid nitrogen and a pulverizer to obtain pellets of the block copolymer containing the 6-membered cyclic acid anhydride group.
[0157] t ブチルエステル部位の 6員環酸無水物基への変換は、 IR (赤外線吸収スぺタト ル)分析および13 C—NMR (核磁気共鳴スペクトル)分析により確認することができた 即ち、 IR分析では、変換後には 1800cm 1あたりに酸無水物基に由来する吸収ス ベクトルが見られるので確認できた。 13C— NMR分析では、変換後には t—ブチル基 のメチン炭素由来の 82ppmのシグナルおよびメチル炭素由来の 28ppmのシグナル が消失するので確認できた。 [0157] The conversion of the t-butyl ester moiety into a 6-membered cyclic anhydride group could be confirmed by IR (infrared absorption spectrum) analysis and 13 C-NMR (nuclear magnetic resonance spectrum) analysis. In the IR analysis, an absorption vector derived from an acid anhydride group was observed around 1800 cm 1 after conversion, which was confirmed. In the 13 C-NMR analysis, 82 ppm signal derived from the methine carbon of the t-butyl group and 28 ppm signal derived from the methyl carbon disappeared after the conversion.
[0158] <製造例 2 :熱可塑性エラストマ一の製造 > <Production Example 2: Production of thermoplastic elastomer>
製造例 1で得られたアクリル系ブロック共重合体 1076. 9gと、ォレフィン系熱可塑 性エラストマ一（商品名サントプレン 111— 80、アドバンスドエラストマーシステムズ社 製） 2153. 8gと、相溶化剤（エチレン一グリシジルメタタリレート一メタアタリレート） 26 9. 2gとを、均一分散されるようにハンドブレンドにて十分に混合した。次いで、ベント 付き 2軸押出し機「TEX30HSS— 25. 5PW— 2V」（日本製鋼所社製)を用い、混練 条件を、 C1〜C3 : 100。C、 C4 : 180°C, C5 : 180°C, C6 : 200°C, C7 : 220°C,ダイ ヘッド： 220°C、回転数： 150rpmとして、溶融混練した。前記押出し機から押出され たストランドは、射出成形しやすいようにペレタイザ一「SCF— 100」（いすずィ匕ェ機（ 株)製)でペレツトイ匕した。得られたペレットは、 80°Cで 3時間以上、乾燥した。 Acrylic block copolymer 1076.9g obtained in Production Example 1, olefin-based thermoplastic elastomer (trade name Santoprene 111-80, manufactured by Advanced Elastomer Systems) 2153.8g, and compatibilizer (ethylene one) Glycidyl metatalylate-meta attalate) 26 9. 2 g was thoroughly mixed by hand blending so as to be uniformly dispersed. Next, using a twin screw extruder “TEX30HSS-25.5PW-2V” (manufactured by Nippon Steel), the kneading conditions were C1 to C3: 100. C, C4: 180 ° C, C5: 180 ° C, C6: 200 ° C, C7: 220 ° C, Die The melt was kneaded at a head of 220 ° C. and a rotational speed of 150 rpm. The strand extruded from the extruder was pelletized with a pelletizer “SCF-100” (manufactured by Isuzu Machinery Co., Ltd.) to facilitate injection molding. The obtained pellets were dried at 80 ° C for 3 hours or more.
[0159] <実施例 1 >  <Example 1>
図 1〜図 4に示した構造のキヤビティ金型 10およびコア金型 20からなる射出成形金 型であって、図 10に示す、高さが 105mmで、蛇腹部 4が、表 1に示す内径および肉 厚を有する榭脂製ブーツ 1を成形可能な金型を、型締め圧力 150TONの射出成形 機「J150E— P」（日本製鋼所社製）にそれぞれ装着した。製造例 2で得られた熱可 塑性エラストマ一組成物のペレットを、シリンダー温度 180°C、ノズル温度 230°C、射 出速度 10%、冷却時間 30秒、金型温度 40°Cで射出成形し、キヤビティ金型 10を開 くと同時にコア金型 20の吹出口 21から発する空気圧 5kgZcm2 (0. 49MPa)でコア 金型 20から脱型し、成形品のゲート部分（図 9における線 Lの部位)から先を切除し て等速ジョイント用ブーツ 1を得た。 An injection mold comprising a cavity mold 10 and a core mold 20 having the structure shown in FIGS. 1 to 4, the height of which is 105 mm, and the bellows portion 4 has an inner diameter shown in Table 1 as shown in FIG. The molds capable of molding the thick resin boot 1 were mounted on an injection molding machine “J150E-P” (manufactured by Nippon Steel Works) with a clamping pressure of 150 TON. Injection molding of pellets of the thermoplastic elastomer composition obtained in Production Example 2 at a cylinder temperature of 180 ° C, a nozzle temperature of 230 ° C, an injection speed of 10%, a cooling time of 30 seconds, and a mold temperature of 40 ° C At the same time that the cavity mold 10 is opened, the mold is removed from the core mold 20 with an air pressure of 5 kgZcm 2 (0.49 MPa) from the outlet 21 of the core mold 20, and the gate part of the molded product (line L in FIG. 9). The constant velocity joint boot 1 was obtained by excising the tip from the above portion.
[0160] [表 1] [0160] [Table 1]
表 1 table 1
Figure imgf000054_0001
Figure imgf000054_0001
[0161] (比較例 1) [0161] (Comparative Example 1)
熱可塑性エラストマ一を成形空間 30内へ射出するためのゲートとして、ドーム状ゲ ートではなく図 16 (a)に示した平面状ゲートを備えた点以外は、ほぼ同様の射出成 形金型を用い、実施例 1と同様にして榭脂製ブーツを製造した。  The injection mold is almost the same except that the gate for injecting the thermoplastic elastomer into the molding space 30 is not a dome-shaped gate but a planar gate as shown in Fig. 16 (a). A boot made of greaves was produced in the same manner as in Example 1.
[0162] 実施例 1においては、成形後にコア金型からの脱型が極めて良好で生産性がよぐ また成形時の樹脂の流れムラが生ずることなぐ良好な外観を有し、また圧縮空気に よる脱型時の変形が小さぐ寸法精度、寸法安定性に優れ、し力もリサイクル可能な 中空成形品 (榭脂製ブーツ)を製造可能することができた。一方、比較例 1において は、成形品 P内に圧入される空気がコア金型 102と成形品 Pとの間に均一にまわらず 、脱型不良が発生した。  [0162] In Example 1, the mold release from the core mold is very good after molding, and the productivity is good. Also, it has a good appearance without causing uneven flow of the resin during molding, and the compressed air As a result, it was possible to manufacture hollow molded products (waxed boots) that have small dimensional accuracy, excellent dimensional stability, and recyclable strength. On the other hand, in Comparative Example 1, the air that was press-fitted into the molded product P was not uniformly distributed between the core mold 102 and the molded product P, and a demolding failure occurred.
[0163] <実施例 2>  [0163] <Example 2>
図 1〜図 4に示した構造のキヤビティ金型 10およびコア金型 20からなる射出成形金 型であって、図 11に示す、高さが 105mmで、蛇腹部 4が、表 2に示す内径および肉 厚を有する榭脂製ブーツ 1 Aを成形可能な金型を、型締め圧力 150TONの射出成 形機「J150E— P」（日本製鋼所社製）にそれぞれ装着した。製造例 2で得られた熱 可塑性エラストマ一組成物のペレットを、シリンダー温度 180°C、ノズル温度 230°C、 射出速度 10%、冷却時間 30秒、金型温度 40°Cで射出成形し、キヤビティ金型 10を 開くと同時にコア金型 20の吹出口 21から発する空気圧 5kgZcm2 (0. 49MPa)でコ ァ金型 20から脱型し、成形品のゲート部分（図 9における線 Lの部位)から先を切除 して等速ジョイント用ブーツ 1 Aを得た。 Injection mold consisting of a cavity mold 10 and a core mold 20 having the structure shown in FIGS. As shown in FIG. 11, a mold capable of forming a resin boot 1A having a height of 105 mm and an accordion portion 4 having an inner diameter and a wall thickness shown in Table 2 at a clamping pressure of 150 TON is used. Each was mounted on an injection molding machine “J150E-P” (manufactured by Nippon Steel Works). The pellets of the thermoplastic elastomer composition obtained in Production Example 2 were injection molded at a cylinder temperature of 180 ° C, a nozzle temperature of 230 ° C, an injection speed of 10%, a cooling time of 30 seconds, and a mold temperature of 40 ° C. At the same time that the cavity mold 10 is opened, the mold mold 20 is removed from the core mold 20 with an air pressure of 5 kgZcm 2 (0.449 MPa) emitted from the outlet 21 of the core mold 20, and the gate part of the molded product (part of line L in Fig. 9). ) To obtain a constant velocity joint boot 1A.
[0164] <実施例 3 >  <Example 3>
製造例 2で得られた熱可塑性エラストマ一組成物のペレットを、型締め圧力 150TO Nの射出成形機「J150E— P」（日本製鋼所社製）にて、図 14に示す構造の成形金 型を用い、シリンダー温度 150〜230°C、ノズル温度 230°C、射出速度 10%、冷却 時間 30秒、金型温度 40°Cの条件で射出成形し、キヤビティ金型 10を開くと同時にコ ァ金型 20の吹出口 21から発する空気圧 5kgZcm2 (0. 49MPa)でコア金型 20から 脱型し、得られた成形品を、ゲート部分に成形される蓋となる部分 cおよびランナー部 分など（図 9における線 Lの部位力も先の部分に相当する部分)を切除して、図 12お よび図 13並びに表 2に示す形状、寸法の榭脂製ブーツ 1Bを得た。 The pellets of the thermoplastic elastomer composition obtained in Production Example 2 were molded using the injection molding machine “J150E-P” (manufactured by Nippon Steel Works) with a mold clamping pressure of 150 TON. Is used for injection molding under the conditions of a cylinder temperature of 150 to 230 ° C, a nozzle temperature of 230 ° C, an injection speed of 10%, a cooling time of 30 seconds, and a mold temperature of 40 ° C. Demold from the core mold 20 with an air pressure of 5kgZcm 2 (0.449MPa) from the air outlet 21 of the mold 20. The resulting molded part is the part c that becomes the lid molded into the gate part and the runner part, etc. (The portion of line L in FIG. 9 also corresponds to the previous portion) was cut out to obtain a resin boot 1B having the shape and dimensions shown in FIGS. 12 and 13 and Table 2.
[0165] <実施例 4>  <Example 4>
谷部 5cの曲率半径 Rを 1. 5mmとした以外は、実施例 3と同様にして榭脂製ブーツ を得た。  A resinous resin boot was obtained in the same manner as in Example 3 except that the curvature radius R of the valley 5c was 1.5 mm.
[0166] 以上の実施例 2〜実施例 4で得られた榭脂製ブーツについて、以下の評価を行つ た。  [0166] The following evaluations were performed on the rosin boots obtained in Examples 2 to 4 above.
(1)蛇腹表面ウエルドライン  (1) Bellows surface weld line
射出成形した 30個のブーツの表面を観察し、ウエルドラインの有無を調べた。 The surfaces of 30 injection-molded boots were observed to check for weld lines.
(2)柔軟性 (2) Flexibility
ブーツを小径取付部から手で下に押さえつけた時に力かる荷重を測定した。荷重 力 S小さいほど柔軟性が良い（柔軟性が悪いとシャフトに取り付けることが困難になる） (3)耐久性 (変形性） The load applied when the boot was pressed down from the small diameter mounting portion by hand was measured. The smaller the load force S, the better the flexibility (if the flexibility is poor, it becomes difficult to attach to the shaft) (3) Durability (deformability)
ドライブシャフトの回転数を 2000rpm、シャフト角度 10° 、温度 80°Cとして、その 最大膨張量 (変形量: mm)を測定した。変形が小さいほど良い。変形が大きい場合、 回転時の遠心力によりブーツが周辺の部材に当たり、蛇腹部が切れやすい。  The maximum expansion amount (deformation amount: mm) was measured at a rotational speed of the drive shaft of 2000 rpm, a shaft angle of 10 °, and a temperature of 80 ° C. The smaller the deformation, the better. When the deformation is large, the boot hits the surrounding members due to the centrifugal force during rotation, and the bellows part is easily cut.
(4)耐久性 (疲労性）  (4) Durability (Fatigue)
ドライブシャフトの回転数を 100i:pm、ジョイント角 40° 、温度を室温として、その耐 久性を測定した。耐久性は、蛇腹部に亀裂が入るまでの時間をその判断指標とした 。蛇腹部に亀裂が入るまでの時間が長いほど疲労性が良い。  The durability of the drive shaft was measured at a rotational speed of 100 i: pm, a joint angle of 40 °, and a temperature of room temperature. Durability was determined by the time taken to crack the bellows. The longer the time it takes for the bellows to crack, the better the fatigue.
[0167] 評価結果を表 2に示す。  [0167] The evaluation results are shown in Table 2.
[0168] [表 2] 表 2  [0168] [Table 2] Table 2
Figure imgf000056_0001
表 2から明らかなように、第一の榭脂製ブーツ形状を有する実施例 2の等速ジョイン トブーツ 1Aは、全体に柔軟性および耐久性に優れる。この結果から、蛇腹部におけ る少なくとも一部の谷部を肉厚に形成することで、回転時の遠心力による膨張が防止 されるとともに、反対に山部の肉厚は薄くすることで、蛇腹部の柔軟性を損なうことが なぐ更に各谷部の肉厚を、それに対してゲート側の取付部寄りに隣り合う山部の厚 みと同じか、それより厚く形成することで、榭脂の連続性が保持されたまま山部から谷 部へと円滑に榭脂が流れて充填され、ウエルドラインが発生することもなぐ外観性、 耐久性に優れた榭脂ブーツを製造可能であることが分力る。
Figure imgf000056_0001
As is apparent from Table 2, the constant velocity joint boot 1A of Example 2 having the first resinous boot shape is excellent in flexibility and durability as a whole. From this result, the bellows By forming at least some of the valleys thicker, expansion due to centrifugal force during rotation is prevented, and conversely, by reducing the wall thickness of the peaks, the flexibility of the bellows is impaired. In addition, the thickness of each valley is the same as or thicker than that of the adjacent peak near the gate side mounting part, so that the continuity of the resin is maintained. It is possible to produce a grease boot with excellent appearance and durability that allows the grease to flow and fill smoothly from the peak to the valley, without generating weld lines.
[0170] また、第二の榭脂製ブーツ形状を有する実施例 3および実施例 4の等速ジョイント ブーツは、第一の榭脂製ブーツ形状を有する実施例 2のブーツに比べて蛇腹部およ び取付部の肉厚が薄いにもかかわらず、柔軟性および変形性に優れる。この結果か ら、蛇腹部 4における大径取付部に最も近い谷部 5cの内径 dや山部 6cの外径を小  [0170] Further, the constant velocity joint boots of Example 3 and Example 4 having the second greave boot shape have a bellows part shape that is larger than the boot of Example 2 having the first greave boot shape. Despite its thin wall thickness, it has excellent flexibility and deformability. From this result, the inner diameter d of the valley 5c and the outer diameter of the crest 6c closest to the large-diameter mounting part in the bellows part 4 are reduced.
3  Three
さくすることで、回転時の遠心力による膨張が防止されるとともに、蛇腹部の肉厚を薄 くすることで柔軟性に優れたブーツを得ることができることが明らかとなった。更に、実 施例 3と実施例 4との比較から、前記谷部 5cの曲率半径を大きくすることで、疲労性 力 S改善されることが分かる。  As a result, it became clear that expansion due to centrifugal force during rotation was prevented, and that a boot having excellent flexibility could be obtained by reducing the thickness of the bellows portion. Furthermore, it can be seen from a comparison between Example 3 and Example 4 that the fatigue strength S is improved by increasing the radius of curvature of the valley 5c.
産業上の利用可能性  Industrial applicability
[0171] 本発明により、柔軟で、蛇腹部の肉厚が薄くとも柔軟性および耐久性に優れ、等速 ジョイント用のブーツとして過酷な条件下でも使用可能であり、従来のクロ口プレン製 ブーツに代わるリサイクル可能な榭脂製ブーツを提供することができる。 [0171] According to the present invention, it is flexible and excellent in flexibility and durability even when the bellows portion is thin, and can be used as a boot for a constant velocity joint even under severe conditions. Recyclable rosin boots can be provided as an alternative.

Claims

請求の範囲 The scope of the claims
[1] 開閉可能に分割されたキヤビティ金型と、該キヤビティ金型内に配置されるコア金 型とからなる成形金型の前記キヤビティ金型とコア金型との間に形成される成形空間 内に、溶融した熱可塑性榭脂を射出、充填して、両端に開口した筒状の中空成形品 を製造する射出成形法であって、該成形空間内で成形される中空成形品の一方の 開口端縁から該成形品の軸方向外側に突出するように前記金型の成形空間に連通 して設けたドーム状ゲートの頂点部分の 1箇所から、成形される中空成形品の軸方 向に向カゝつて溶融した熱可塑性榭脂を射出し、該ドーム状ゲートを介して成形空間 内に熱可塑性榭脂を射出、充填して、一端が閉止された中空成形品を成形し、成形 後、前記キヤビティ金型を開くとともに、コア金型に外嵌されている中空成形品の内 部に、該コア金型におけるドーム状ゲートの頂点部分から高圧空気を成形品の軸方 向に向力つて吹き付けることにより、コア金型力 成形品を取り出すことを特徴とする 、中空成形品の射出成形法。  [1] A molding space formed between the cavity mold and the core mold of a molding mold including a cavity mold divided so as to be openable and closable and a core mold disposed in the cavity mold. An injection molding method for producing a cylindrical hollow molded product having both ends injected and filled with molten thermoplastic resin and having openings at both ends, and one of the hollow molded products molded in the molding space. From one point of the apex portion of the dome-shaped gate provided in communication with the molding space of the mold so as to protrude outward in the axial direction of the molded product from the opening edge, in the axial direction of the hollow molded product to be molded After injection, the molten thermoplastic resin is injected, and through the dome-shaped gate, the thermoplastic resin is injected and filled into the molding space to form a hollow molded product with one end closed, and after molding The cavity mold is opened and hollowed around the core mold. The core mold force molded product is taken out by blowing high-pressure air in the axial direction of the molded product from the apex of the dome-shaped gate in the core mold to the inside of the molded product. Injection molding of hollow molded products.
[2] 前記ドーム状ゲートが略半球状であり、該略半球状ゲートの頂点部分に設けた注 入孔から溶融した熱可塑性榭脂を射出する請求項 1記載の射出成形法。  2. The injection molding method according to claim 1, wherein the dome-shaped gate has a substantially hemispherical shape, and molten thermoplastic resin is injected from a pouring hole provided at a top portion of the substantially hemispherical gate.
[3] 溶融した熱可塑性榭脂を、前記ドーム状ゲートから前記成形空間内で成形される 成形品の軸方向に向かって成形空間内へ射出、充填してなる請求項 2に記載の射 出成形法。  [3] The ejection according to claim 2, wherein molten thermoplastic resin is injected and filled from the dome-shaped gate into the molding space in the axial direction of the molded product molded in the molding space. Molding method.
[4] 前記中空成形品が、両端に開口した一対の環状取付部と、両者を一体に連結する 蛇腹部とを備える請求項 1〜3のいずれかに記載の射出成形法。  [4] The injection molding method according to any one of claims 1 to 3, wherein the hollow molded article includes a pair of annular mounting portions opened at both ends, and a bellows portion integrally connecting the two.
[5] 前記中空成形品が、前記一対の取付部のうちの一方が他方に比べて大径であり、 成形金型における小径取付部側の開口端縁に設けたドーム状ゲートを介して成形 空間内へ溶融した熱可塑製榭脂を射出、充填してなる請求項 4に記載の射出成形 法。  [5] The hollow molded product is molded through a dome-shaped gate provided at an opening edge on the small-diameter mounting portion side of the molding die, one of the pair of mounting portions having a larger diameter than the other. 5. The injection molding method according to claim 4, wherein a molten thermoplastic resin is injected and filled into the space.
[6] 前記中空成形品が、アウターケースに取り付けられる大径取付部と、シャフトに取り 付けられる小径取付部と、両者を一体に連結する蛇腹部とを備える等速ジョイント用 ブーツである請求項 5に記載の射出成形法。  6. The hollow molded article is a constant velocity joint boot comprising a large-diameter attachment portion attached to an outer case, a small-diameter attachment portion attached to a shaft, and a bellows portion integrally connecting the two. 5. The injection molding method according to 5.
[7] 前記熱可塑性榭脂が、熱可塑性エラストマ一である請求項 1に記載の射出成形法 7. The injection molding method according to claim 1, wherein the thermoplastic resin is a thermoplastic elastomer.
[8] 前記熱可塑性エラストマー榭脂が、アクリル系ブロック共重合体 (A)を含む請求項[8] The thermoplastic elastomer resin containing the acrylic block copolymer (A).
7に記載の射出成形法。 7. The injection molding method according to 7.
[9] 前記熱可塑性エラストマー榭脂が、アクリル系ブロック共重合体 (A)と、ォレフィン 系熱可塑性エラストマ一（B)を含む熱可塑性エラストマ一組成物である請求項 8に記 載の射出成形法。 9. The injection molding according to claim 8, wherein the thermoplastic elastomer resin is a thermoplastic elastomer composition containing an acrylic block copolymer (A) and an olefin thermoplastic elastomer (B). Law.
[10] 前記熱可塑性エラストマ一組成物力 アクリル系ブロック共重合体 (A) 100重量部 に対し、ォレフィン系熱可塑性エラストマ一（B) 50〜600重量部および相溶化剤 (C) [10] Composition strength of the thermoplastic elastomer Acrylic block copolymer (A) 100 parts by weight of olefin-based thermoplastic elastomer (B) 50 to 600 parts by weight and compatibilizer (C)
5〜50重量部を含む請求項 9に記載の射出成型法。 The injection molding method according to claim 9, comprising 5 to 50 parts by weight.
[11] 前記アクリル系ブロック共重合体 (A)が、アクリル系重合体ブロック（a)を 50〜90重 量％含有し、メタアクリル系重合体ブロック (b)を 50〜10重量％含有する請求項 8〜[11] The acrylic block copolymer (A) contains 50 to 90% by weight of the acrylic polymer block (a) and 50 to 10% by weight of the methacrylic polymer block (b). Claim 8 ~
10のいずれかに記載の射出成形法。 The injection molding method according to any one of 10 above.
[12] 前記アクリル系重合体ブロック（a)およびメタアクリル系重合体ブロック (b)の少なく とも一方の重合体ブロックに反応性官能基 (c)を有する請求項 11に記載の射出成形 法。 12. The injection molding method according to claim 11, wherein at least one of the acrylic polymer block (a) and the methacrylic polymer block (b) has a reactive functional group (c).
[13] 前記ォレフィン系熱可塑性エラストマ一（B)力 ォレフィン榭脂中で EPDMゴムまた はアクリロニトリル.ブタジエンゴムを動的に架橋したものである請求項 9または 10に 記載の射出成形法。  13. The injection molding method according to claim 9 or 10, wherein EPDM rubber or acrylonitrile-butadiene rubber is dynamically cross-linked in the olefin-based thermoplastic elastomer (B) strength olefin resin.
[14] 前記相溶化剤 (C)が、エポキシ基を含有するォレフイン系熱可塑性榭脂である請 求項 10に記載の射出成形法。  [14] The injection molding method according to claim 10, wherein the compatibilizing agent (C) is an epoxy-based thermoplastic resin containing an epoxy group.
[15] 開閉可能に分割されたキヤビティ金型と、該キヤビティ金型内に配置されるコア金 型とからなり、前記キヤビティ金型とコア金型との間に形成される成形空間内に、溶融 した熱可塑性榭脂を射出、充填して、両端に開口した筒状の中空成形品を製造する 射出成形金型であって、前記成形空間から、該成形空間内で成形される成形品の 軸方向外側に突出するようにドーム状ゲートを設け、該ドーム状ゲートの頂点部分に 位置するキヤビティ金型に 1箇所の注入孔を設けるとともに、前記コア金型におけるド ーム状ゲートの頂点部分内面に、高圧空気供給手段に連通する開閉可能な吹出口 を設けてなり、溶融した熱可塑性榭脂を、前記注入孔から前記ドーム状ゲートを介し て成形空間内に射出、充填して中空成形品を成形した後、前記キヤビティ金型を開 くとともに前記吹出口を開放して高圧空気供給手段力 前記吹出口を介して中空成 形品の内部に高圧空気を吹き付けることにより、コア金型力 成形品を取り出すよう に構成してなることを特徴とする、中空成形品の射出成形金型。 [15] A cavity mold divided so as to be openable and closable and a core mold disposed in the cavity mold, and in a molding space formed between the cavity mold and the core mold, An injection mold for injecting and filling a molten thermoplastic resin to produce a hollow cylindrical molded product having openings at both ends, wherein the molded product is molded from the molding space into the molding space. A dome-shaped gate is provided so as to protrude outward in the axial direction, and one injection hole is provided in the cavity mold located at the apex of the dome-shaped gate, and the apex of the domed gate in the core mold An openable and closable outlet that communicates with the high-pressure air supply means is provided on the inner surface, and the molten thermoplastic resin is fed from the injection hole through the dome-shaped gate. After the hollow molding product is molded by injection and filling into the molding space, the cavity mold is opened and the air outlet is opened, and the high pressure air supply means force is passed through the air outlet. An injection mold for a hollow molded product, characterized in that a core mold force molded product is taken out by blowing high pressure air onto the mold.
[16] 前記ドーム状ゲートが略半球状であり、該略半球状ゲートの頂点部分に、成形され る中空成形品の軸方向にのびる注入孔を設けてなる請求項 15記載の射出成形金 型。  16. The injection mold according to claim 15, wherein the dome-shaped gate is substantially hemispherical, and an injection hole extending in the axial direction of a hollow molded article to be molded is provided at a vertex portion of the substantially hemispherical gate. .
[17] 前記ドーム状ゲートにおける前記成形空間への開口端縁が、成形空間内で成形さ れる中空成形品の軸方向と同方向となるように形成されてなる請求項 16に記載の射 出成形金型。  17. The projection according to claim 16, wherein an opening edge to the molding space in the dome-shaped gate is formed so as to be in the same direction as an axial direction of a hollow molded product molded in the molding space. Molding mold.
[18] 前記コア金型の軸芯部分に、その軸方向に貫通し、高圧空気供給手段に連結され る通気孔を設け、該通気孔の先端部を前記吹出口とし、前記通気孔内に、先端を前 記ドーム状ゲートに臨ませて、コア金型の軸方向に摺動する開閉軸を設け、該開閉 軸により前記吹出口を開閉可能としてなる請求項 15に記載の射出成形金型。  [18] A vent hole penetrating in the axial direction of the core mold of the core mold and connected to the high-pressure air supply means is provided, and a tip portion of the vent hole serves as the outlet, and the vent hole is provided in the vent hole. 16. The injection mold according to claim 15, wherein an opening / closing shaft that slides in the axial direction of the core mold is provided with the tip facing the dome-shaped gate, and the air outlet can be opened / closed by the opening / closing shaft. .
[19] 前記通気孔内部の内周面に、軸方向に伸びる単数または複数の通気溝を設け、 前記開閉軸を、その先端が前記通気溝を設けた位置にくるまで後退させることで、吹 出口を開口するとともに通気孔力 前記通気溝および吹出口を介して高圧空気を中 空成形品の内部に吹き付け可能とした請求項 18に記載の射出成形金型。  [19] One or more ventilation grooves extending in the axial direction are provided on the inner peripheral surface inside the ventilation hole, and the opening and closing shaft is retracted until its tip comes to the position where the ventilation groove is provided. 19. The injection mold according to claim 18, wherein the outlet is open and the air hole force is high pressure air can be blown into the hollow molded product through the air groove and the air outlet.
[20] 両端に開口した一対の環状取付部と、両者を一体に連結する蛇腹部とを備える中 空成形品を成形するための成形金型である請求項 15〜19のいずれかに記載の射 出成形金型。  [20] The molding die according to any one of claims 15 to 19, which is a molding die for molding a hollow molded article including a pair of annular mounting portions opened at both ends and a bellows portion integrally connecting the two. Injection mold.
[21] 前記一対の取付部のうちの一方が他方に比べて大径である中空成形品を成形す るための成形金型であり、成形空間における小径取付部の開口端縁に前記ドーム状 ゲートを設けてなる請求項 20に記載の射出成形金型。  [21] A molding die for molding a hollow molded product in which one of the pair of mounting portions has a larger diameter than the other, and the dome shape is formed at an opening edge of the small-diameter mounting portion in a molding space. 21. The injection mold according to claim 20, further comprising a gate.
[22] アウターケースに取り付けられる大径取付部と、シャフトに取り付けられる小径取付 部と、両者を一体に連結する蛇腹部とを備える等速ジョイント用ブーツを成形するた めの成形金型である請求項 21に記載の射出成形金型。 [22] A molding die for molding a constant velocity joint boot having a large-diameter mounting portion attached to an outer case, a small-diameter mounting portion attached to a shaft, and a bellows portion integrally connecting the two. The injection mold according to claim 21.
[23] 請求項 1に記載の射出成形法により、両端に開口した一対の取付部と、両者を一 体に連結する蛇腹部とを備え、一方の取付部側に設けたゲートから金型成形空間内 へ熱可塑性エラストマ一榭脂を射出、充填して成形してなる榭脂製ブーツであって、 前記蛇腹部における各谷部を、それぞれの谷部に対して前記ゲート側の取付部寄り に隣り合う山部の厚みと同じ力、それより厚く形成してなり、かつ少なくとも一部の谷 部は前記隣り合う山部より厚く形成してなることを特徴とする榭脂製ブーツ。 [23] According to the injection molding method of claim 1, a pair of attachment portions opened at both ends and the both are integrated. And a bellows portion connected to the body, and a resinous boot formed by injecting and filling a thermoplastic elastomer resin into a mold forming space from a gate provided on one attachment portion side, Each valley portion in the bellows portion is formed to have the same force as the thickness of the adjacent peak portion near the gate side attachment portion with respect to each valley portion, and thicker than that, and at least some of the valley portions are A rosin boot characterized by being formed thicker than the adjacent mountain portions.
[24] 前記一対の取付部のうちの一方が他方に比べて大径であり、成形金型における小 径取付部側に設けたゲートから熱可塑製エラストマ一榭脂を射出して成形してなる請 求項 23に記載の榭脂製ブーツ。  [24] One of the pair of attachment portions has a larger diameter than the other, and is molded by injecting a thermoplastic elastomer resin from a gate provided on the small diameter attachment portion side of the molding die. The boot made of grease according to claim 23.
[25] アウターケースに取り付けられる大径取付部と、シャフトに取り付けられる小径取付 部と、両者を一体に連結する蛇腹部とを備える等速ジョイント用ブーツである請求項 24に記載の榭脂製ブーツ。  [25] The resinous product according to claim 24, which is a constant velocity joint boot comprising a large-diameter attachment portion attached to the outer case, a small-diameter attachment portion attached to the shaft, and a bellows portion integrally connecting the two. boots.
[26] 請求項 1に記載の射出成形法により熱可塑性エラストマー榭脂にて射出成形して なる榭脂製ブーツであって、大径取付部と小径取付部との、両端に開口した一対の 取付部と、前記大径取付部と小径取付部とを一体に連結し前記大径取付部から小 径取付部に向力つてその直径が順次小さくなる蛇腹部とを備え、前記大径取付部に 最も近い谷部の内径 dを、蛇腹部における小径取付部側の開口径 Dより大きぐかつ  [26] A resin boot made by injection molding with a thermoplastic elastomer resin by the injection molding method according to claim 1, wherein a pair of large-diameter mounting portions and small-diameter mounting portions open at both ends. A large-diameter mounting portion, comprising: a mounting portion; and a bellows portion in which the large-diameter mounting portion and the small-diameter mounting portion are integrally connected, and the diameter gradually decreases from the large-diameter mounting portion toward the small-diameter mounting portion. The inner diameter d of the valley portion closest to the diameter is larger than the opening diameter D on the small diameter mounting portion side in the bellows portion and
1  1
蛇腹部における大径取付部側の開口径 Dの 60%以下とするとともに、前記大径取  The bellows part should be 60% or less of the opening diameter D on the large-diameter mounting part side, and the large-diameter
2  2
付部に最も近い谷部の曲率半径を 2〜： LOmmとしてなることを特徴とする榭脂製ブー ッ。  A boot made of resin, characterized in that the radius of curvature of the valley closest to the attachment is 2 to: LOmm.
[27] 前記大径取付部に最も近い山部の外径を、蛇腹部における大径取付部側の開口 径 Dより小さくしてなる請求項 26に記載の榭脂製ブーツ。  27. The rosin boot according to claim 26, wherein an outer diameter of a peak portion closest to the large diameter attachment portion is smaller than an opening diameter D on the large diameter attachment portion side in the bellows portion.
2  2
[28] 前記蛇腹部の肉厚が 3mm以下である請求項 26に記載の榭脂製ブーツ。  [28] The greaves boot according to [26], wherein the bellows portion has a thickness of 3 mm or less.
[29] 前記蛇腹部における大径取付部側の開口縁に、ブーツの軸芯に平行にのびる円 筒状の周壁部を形成してなる請求項 26に記載の榭脂製ブーツ。  29. The rosin boot according to claim 26, wherein a cylindrical peripheral wall portion extending in parallel with the axial center of the boot is formed at an opening edge of the bellows portion on the large diameter attachment portion side.
[30] 熱可塑性エラストマー榭脂が、アクリル系ブロック共重合体 (A)を含む請求項 23〜[30] The thermoplastic elastomer resin includes an acrylic block copolymer (A).
29の 、ずれかに記載の榭脂製ブーツ。 29. The boot made of greaves according to any of the above.
[31] 熱可塑性エラストマー榭脂が、アクリル系ブロック共重合体 (A)と、ォレフィン系熱 可塑性エラストマ一（B)を含む熱可塑性エラストマ一組成物である請求項 30に記載 の榭脂製ブーツ。 31. The thermoplastic elastomer composition according to claim 30, wherein the thermoplastic elastomer resin is a thermoplastic elastomer composition comprising an acrylic block copolymer (A) and an olefin-based thermoplastic elastomer (B). Boots made of greaves.
[32] 熱可塑性エラストマ一組成物力 アクリル系ブロック共重合体 (A) 100重量部に対 し、ォレフィン系熱可塑性エラストマ一 50〜600重量部（B)、相溶化剤 (C) 5〜50重 量部を含む請求項 31に記載の榭脂製ブーツ。  [32] Composition strength of thermoplastic elastomer Acrylic block copolymer (A) 50 to 600 parts by weight of olefin-based thermoplastic elastomer (B), compatibilizer (C) 5 to 50 parts per 100 parts by weight 32. A greave boot according to claim 31, comprising an amount portion.
[33] アクリル系ブロック共重合体 (A)力 アクリル系重合体ブロック (a)およびメタアクリル 系重合体ブロック (b)からなり、少なくとも一方の重合体ブロックに反応性官能基 (c) を有する請求項 30に記載の榭脂製ブーツ。 [33] Acrylic block copolymer (A) force It consists of an acrylic polymer block (a) and a methacrylic polymer block (b), and at least one polymer block has a reactive functional group (c) 31. A greave boot according to claim 30.
[34] アクリル系ブロック共重合体 (A)中の反応性官能基 (c)が、一般式（1)： [34] The reactive functional group (c) in the acrylic block copolymer (A) is represented by the general formula (1):
[化 1]  [Chemical 1]
Figure imgf000062_0001
Figure imgf000062_0001
(式中、 R1は水素原子またはメチル基で、互いに同一でも異なっていてもよぐ pは 0 または 1の整数、 qは 0〜3の整数)で表わされる酸無水物基を含有する単位 (cl)お よび Zまたはカルボキシル基を含有する単位 (c2)を有する請求項 33に記載の榭脂 製ブーツ。 (Wherein R 1 is a hydrogen atom or a methyl group, which may be the same or different from each other, p is an integer of 0 or 1, q is an integer of 0 to 3) 34. A cocoa resin boot according to claim 33, which has (cl) and a unit (c2) containing Z or a carboxyl group.
[35] 熱可塑性エラストマ一組成物力 アクリル系ブロック共重合体 (A)全体中に、カルボ キシル基を含有する単位 (c2)を 0. 1〜50重量％含有する請求項 34に記載の榭脂 製ブーツ。  [35] The composition of thermoplastic elastomer as set forth in claim 34, wherein the acrylic block copolymer (A) contains 0.1 to 50% by weight of units (c2) containing a carboxyl group. Made boots.
[36] アクリル系ブロック共重合体 (A)力 アクリル系重合体ブロック（a)を 50〜90重量％ 含有し、メタアクリル系重合体ブロック (b)を 50〜10重量％含有する請求項 30に記 載の榭脂製ブーツ  [36] Acrylic block copolymer (A) Force Acrylic polymer block (a) is contained in an amount of 50 to 90% by weight, and methacrylic polymer block (b) is contained in an amount of 50 to 10% by weight. The boot made of greaves described in
[37] アクリル系ブロック共重合体 (A)が、原子移動ラジカル重合により製造されたブロッ ク共重合体である請求項 30に記載の榭脂製ブーツ。 [37] An acrylic block copolymer (A) is produced by atom transfer radical polymerization. 31. The greave boot according to claim 30, which is a copolymer.
[38] ォレフィン系熱可塑性エラストマ一（B)力 ォレフィン系榭脂中で EPDMゴムまたは アクリロニトリル.ブタジエンゴムを動的に架橋したものである請求項 31に記載の榭脂 製ブーツ。 [38] The resin-made boot according to claim 31, wherein the polyolefin-based thermoplastic elastomer (B) has an EPDM rubber or acrylonitrile-butadiene rubber dynamically cross-linked in an olefin-based resin.
[39] 相溶化剤 (C)が、エポキシ基を含有するォレフイン系熱可塑性榭脂である請求項 3 2に記載の榭脂製ブーツ。  39. The resin-made boot according to claim 32, wherein the compatibilizing agent (C) is an olefin-based thermoplastic resin containing an epoxy group.
PCT/JP2006/306110 2005-03-29 2006-03-27 Method of injection-molding hollow molded article, mold for injection molding, and boot made of resin WO2006104083A1 (en)

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CN103831954A (en) * 2012-11-26 2014-06-04 株式会社捷太格特 Molding die for molding boot for constant velocity joint
WO2017116323A1 (en) * 2015-12-29 2017-07-06 Mir Arastirma Ve Gelistirme A.S. Molding core, mold and fluid-aided molding method
WO2022224856A1 (en) * 2021-04-23 2022-10-27 大塚化学株式会社 Sealing member

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JPH0492166A (en) * 1990-08-07 1992-03-25 Honda Motor Co Ltd Boot for universal joint and manufacture thereof
JP2548165Y2 (en) * 1992-02-29 1997-09-17 キーパー株式会社 Injection mold
JPH1073162A (en) * 1996-08-29 1998-03-17 Suzuki Motor Corp Boots and its molding/extracting method
JPH11166624A (en) * 1997-09-30 1999-06-22 Ntn Corp Constant velocity universal joint
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Publication number Priority date Publication date Assignee Title
CN103831954A (en) * 2012-11-26 2014-06-04 株式会社捷太格特 Molding die for molding boot for constant velocity joint
CN103831954B (en) * 2012-11-26 2017-04-26 株式会社捷太格特 Molding die for molding boot for constant velocity joint
WO2017116323A1 (en) * 2015-12-29 2017-07-06 Mir Arastirma Ve Gelistirme A.S. Molding core, mold and fluid-aided molding method
WO2022224856A1 (en) * 2021-04-23 2022-10-27 大塚化学株式会社 Sealing member

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