WO2011030732A1 - Foam-molded articles and process for production thereof - Google Patents

Foam-molded articles and process for production thereof Download PDF

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Publication number
WO2011030732A1
WO2011030732A1 PCT/JP2010/065239 JP2010065239W WO2011030732A1 WO 2011030732 A1 WO2011030732 A1 WO 2011030732A1 JP 2010065239 W JP2010065239 W JP 2010065239W WO 2011030732 A1 WO2011030732 A1 WO 2011030732A1
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resin particles
weight
resin
parts
transmittance
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PCT/JP2010/065239
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French (fr)
Japanese (ja)
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裕一 権藤
英保 松村
貴司 岡
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積水化成品工業株式会社
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Priority to JP2011530829A priority Critical patent/JP5713909B2/en
Publication of WO2011030732A1 publication Critical patent/WO2011030732A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/22—After-treatment of expandable particles; Forming foamed products
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/12—Powdering or granulating
    • C08J3/126—Polymer particles coated by polymer, e.g. core shell structures
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/0014—Use of organic additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/16—Making expandable particles
    • C08J9/18—Making expandable particles by impregnating polymer particles with the blowing agent
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/22—After-treatment of expandable particles; Forming foamed products
    • C08J9/224—Surface treatment
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/22—After-treatment of expandable particles; Forming foamed products
    • C08J9/228—Forming foamed products
    • C08J9/232—Forming foamed products by sintering expandable particles
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
    • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2323/00—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers
    • C08J2323/02—Characterised by the use of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Derivatives of such polymers not modified by chemical after treatment
    • C08J2323/04—Homopolymers or copolymers of ethene
    • C08J2323/08—Copolymers of ethene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2325/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Derivatives of such polymers
    • C08J2325/02—Homopolymers or copolymers of hydrocarbons
    • C08J2325/04—Homopolymers or copolymers of styrene
    • C08J2325/06—Polystyrene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2351/00—Characterised by the use of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers
    • C08J2351/06—Characterised by the use of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Derivatives of such polymers grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2425/00—Characterised by the use of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an aromatic carbocyclic ring; Derivatives of such polymers
    • C08J2425/02—Homopolymers or copolymers of hydrocarbons
    • C08J2425/04—Homopolymers or copolymers of styrene
    • C08J2425/06—Polystyrene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00—Use of organic ingredients
    • C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
    • C08K5/005—Stabilisers against oxidation, heat, light, ozone

Definitions

  • the present invention relates to a foam molded article and a method for producing the same. More specifically, the present invention relates to a foamed molded article having an ultraviolet absorbing function and a method for producing the same.
  • the foamed molded product of the present invention is suitable for a container for transporting and / or storing an electrical product selected from a liquid crystal display panel, a solar battery cell, a semiconductor wafer, and a semiconductor device that may be damaged by ultraviolet rays.
  • a resin container is usually used, and a foamed molded article having a shock-absorbing property is particularly preferably used.
  • the manufacturing place and the sales place may be separated from each other, and in the case of a part, the part manufacturing place and the place where the part is incorporated into the product may be separated from each other.
  • these places may cross borders. Therefore, transportation or storage of products or parts may take a long time.
  • electrical products such as liquid crystal display panels, solar cells, semiconductor wafers, and semiconductor devices are deteriorated by irradiation with ultraviolet rays.
  • containers are required to have shielding properties against ultraviolet rays that are exposed during transportation and storage.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 2002-155161 is cited as a literature for examining a method in which an ultraviolet absorber is preliminarily present in a resin component in order to produce a foamed molded article provided with an ultraviolet absorber.
  • the resin component and the ultraviolet absorber are mixed by an extruder, and the foamed resin particles are obtained by impregnating the extruded pellets with a foaming agent.
  • the above publication uses an ultraviolet absorber for the purpose of improving the weather resistance. Moreover, the ultraviolet absorber is mixed with the resin component by an extruder. Therefore, the foamed molded product obtained can shield a certain amount of ultraviolet rays. However, it has been demanded to provide a foamed molded article that can efficiently and easily mix an ultraviolet absorbent with a resin component, further improve ultraviolet shielding properties, and also has impact resistance, and a method for producing the same.
  • the method for producing resin particles various methods such as an extrusion method, a suspension polymerization method, and an emulsion polymerization method are known.
  • the addition timing of the ultraviolet absorber is not at the time of production of the resin particles but at the impregnation of the foaming agent, so that the ultraviolet shielding property can be obtained at a high level.
  • a foamed molded article having both impact resistance and the present invention was obtained.
  • expandable resin particles are obtained by contacting resin particles that can become expandable resin particles and an ultraviolet absorber when impregnated with the foaming agent, and then the expanded resin particles are pre-expanded to be pre-expanded particles. And Further, the pre-expanded particles are molded in-mold into a shape corresponding to a transport / storage container for electrical products selected from liquid crystal display panels, solar cells, semiconductor wafers and semiconductor devices.
  • a method for producing a foamed molded product comprising a step of obtaining a molded product.
  • a foam molded article obtained from expandable resin particles containing an ultraviolet absorber is selected from a liquid crystal display panel, a solar battery cell, a semiconductor wafer, and a semiconductor device having a transmittance of light having a wavelength of 365 nm of 3% or less in a sample cut to a thickness of 5 mm from the skin.
  • An expanded molded article for a container for transporting and storing electrical products is provided.
  • the ultraviolet absorbent can be easily and efficiently absorbed into the resin particles by setting the contact timing of the resin particles and the ultraviolet absorbent at the time of impregnation with the foaming agent. Therefore, according to the present invention, it is possible to obtain a foamed molded article having both ultraviolet shielding properties and impact resistance. Further, when the ultraviolet absorber is a benzotriazole-based or benzophenone-based ultraviolet absorber and is used in an amount of 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the resin particles, the ultraviolet shielding property is further improved. A foamed molded product can be obtained.
  • the resin particles are resin particles containing a polyolefin resin and a polystyrene resin, even if the polystyrene resin component is increased in order to improve the bead life, the impact resistance and A foamed molded article having excellent crack resistance can be obtained.
  • the resin particles are resin particles containing 100 parts by weight of a polyolefin resin and 120 to 560 parts by weight of a polystyrene resin
  • the impact resistance and crack resistance are high while maintaining ultraviolet shielding properties.
  • a foamed molded body compatible with the above can be obtained.
  • the foamed molded product of the present invention has a high level of both UV shielding and impact resistance, and therefore a container for transporting and storing electrical products selected from liquid crystal display panels, solar cells, semiconductor wafers and semiconductor devices. Useful as.
  • expandable resin particles obtained by bringing resin particles and an ultraviolet absorber into contact with each other at the time of impregnation with the foaming agent are used.
  • the contact of the ultraviolet absorbent with the resin particles is performed by the presence of the ultraviolet absorbent around the resin particles when the foaming agent is impregnated.
  • the ultraviolet absorber may be added simultaneously with the impregnation of the foaming agent, or may be added to a system in which resin particles are present before the impregnation of the foaming agent.
  • (Expandable resin particles) (1) Resin particles
  • the resin particles are not particularly limited as long as they are particles that can become expandable resin particles, in other words, particles that can be impregnated with a foaming agent.
  • the resin particle which consists of resin components, such as polyolefin resin, polystyrene resin, and the mixture of these resin, is mentioned.
  • the resin component may contain a rubber component (polybutadiene, butadiene-styrene copolymer, etc.) as long as the effects of the present invention are not hindered.
  • polyolefin-type resin A well-known resin can be used.
  • the polyolefin resin may be cross-linked.
  • polyethylene resins such as branched low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, and cross-linked products of these polymers
  • polypropylene resins such as propylene homopolymer, ethylene-propylene random copolymer, propylene-1-butene copolymer, and ethylene-propylene-butene random copolymer.
  • the low density is preferably 0.91 ⁇ 0.94g / cm 3, more preferably 0.91 ⁇ 0.93g / cm 3.
  • the high density is preferably 0.95 to 0.97 g / cm 3 , and more preferably 0.95 to 0.96 g / cm 3 .
  • the medium density is an intermediate density between these low density and high density.
  • Polystyrene resin is polystyrene or a copolymer of styrene as a main component and other monomers copolymerizable with styrene.
  • the main component means that styrene accounts for 70% by weight or more of the total monomers.
  • examples of other monomers include ⁇ -methylstyrene, p-methylstyrene, acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid, alkyl acrylate ester, alkyl methacrylate ester, divinylbenzene, polyethylene glycol dimethacrylate, and the like.
  • alkyl means alkyl having 1 to 8 carbon atoms.
  • the resin component preferably contains a polyolefin resin and a polystyrene resin at the same time.
  • the polyolefin resin used is preferably a branched low density polyethylene, a linear low density polyethylene or an ethylene-vinyl acetate copolymer
  • the polystyrene resin is a polystyrene, styrene-alkyl acrylate copolymer copolymer.
  • a polymer or a styrene-methacrylic acid alkyl ester copolymer is preferred.
  • the polystyrene resin is preferably contained in the resin particles in the range of 120 to 560 parts by weight with respect to 100 parts by weight of the polyolefin resin particles.
  • the crack resistance of a foaming molding may fall.
  • the cracking resistance is greatly improved, but the dissipation of the foaming agent from the surface of the expandable resin particles tends to be accelerated. Therefore, the bead life of the expandable resin particles may be shortened due to a decrease in the retention of the foaming agent.
  • a more preferable content of the polystyrene resin is 140 to 450 parts by weight, and a more preferable content is 150 to 400 parts by weight.
  • Examples of the method of simultaneously including a polyolefin resin and a polystyrene resin include, for example, a method of kneading both resins in an extruder, impregnating particles made of a polyolefin resin with an styrene monomer in an aqueous medium, Examples thereof include a method of polymerizing the monomer.
  • the latter method is preferable from the viewpoint of more uniformly mixing both resins and obtaining particles having a more spherical shape.
  • the resin particles obtained by the latter method are referred to as composite resin particles made of polyolefin and polystyrene.
  • the latter method will be described.
  • polyolefin resin particles as a raw material can be obtained by a known method.
  • polyolefin resin particles can be prepared by first melt-extruding a polyolefin resin using an extruder and then granulating it by underwater cutting, strand cutting, or the like.
  • the shape of the polyolefin resin to be used is, for example, a true sphere, an oval (egg), a column, a prism, a pellet, or a granular.
  • the polyolefin resin particles are also referred to as micropellets.
  • the polyolefin resin may contain a radical scavenger.
  • the radical scavenger may be added to the polyolefin resin in advance, or may be added simultaneously with melt extrusion.
  • the radical scavenger is preferably a compound having an action of scavenging radicals such as a polymerization inhibitor (including a polymerization inhibitor), a chain transfer agent, an antioxidant, a hindered amine light stabilizer, and the like, which is hardly soluble in water. .
  • the amount of the radical scavenger used is preferably 0.005 to 0.5 parts by weight with respect to 100 parts by weight of the polyolefin resin.
  • Polyolefin resin particles include talc, calcium silicate, calcium stearate, foamed nucleating agents such as synthetic or naturally produced silicon dioxide, ethylenebisstearic acid amide, methacrylic acid ester copolymer, triallyl isocyanurate A flame retardant such as hexabromide and a colorant such as carbon black, iron oxide and graphite may be included.
  • the polyolefin resin particles are dispersed in an aqueous medium in a polymerization vessel and polymerized while impregnating the polyolefin resin particles with a styrene monomer.
  • the aqueous medium include water and a mixed medium of water and a water-soluble solvent (for example, alcohol).
  • any of styrene and substituted styrene (substituent includes lower alkyl, halogen atom (especially chlorine atom) and the like) can be used.
  • the styrenic monomer is a mixture of styrene and substituted styrene, a small amount of other monomers copolymerizable with styrene (for example, acrylonitrile, alkyl methacrylate (about 1 to 8 carbon atoms in the alkyl portion), maleic acid, and the like.
  • styrene preferably occupies a dominant amount (for example, 50% by weight or more).
  • a solvent (plasticizer) such as toluene, xylene, cyclohexane, ethyl acetate, dioctyl adipate may be added to the styrene monomer.
  • the impregnation of the polyolefin resin particles with the styrene monomer may be performed while polymerizing, or may be performed before the polymerization is started. Of these, it is preferable to carry out the polymerization.
  • polymerizing after making it impregnate superposition
  • the styrene monomer not impregnated in the polyolefin resin particles is easily polymerized alone. As a result, a large amount of fine particle polystyrene resin particles may be generated.
  • An oil-soluble radical polymerization initiator can be used for the polymerization of the styrene monomer.
  • a polymerization initiator generally used for the polymerization of styrene monomers can be used.
  • Various methods can be used as a method of adding the polymerization initiator to the aqueous medium in the polymerization vessel. For example, (1) A method in which a polymerization initiator is dissolved and contained in a styrene monomer in a container different from the polymerization container, and the styrene monomer is supplied into the polymerization container.
  • a solution is prepared by dissolving a polymerization initiator in a part of a styrene monomer, a solvent such as isoparaffin or a plasticizer.
  • a dispersion in which a polymerization initiator is dispersed in an aqueous medium is prepared. Examples thereof include a method of supplying the dispersion and the styrene monomer into a polymerization vessel.
  • the polymerization initiator is preferably added in an amount of 0.02 to 2.0% by weight based on the total amount of styrene monomer used.
  • a water-soluble radical polymerization inhibitor it is preferable to dissolve a water-soluble radical polymerization inhibitor in the aqueous medium.
  • the water-soluble radical polymerization inhibitor not only suppresses the polymerization of the styrene monomer on the surface of the polyolefin resin particles, but also prevents the styrene monomer floating in the aqueous medium from being polymerized alone. This is because the generation of fine particles can be reduced.
  • a polymerization inhibitor that can dissolve 1 g or more in 100 g of water can be used.
  • the amount of the water-soluble radical polymerization inhibitor used is preferably 0.001 to 0.04 parts by weight with respect to 100 parts by weight of water in the aqueous medium.
  • a dispersant such as an inorganic dispersant and a surfactant to the aqueous medium.
  • the shape and structure of the polymerization vessel are not particularly limited as long as they are conventionally used for suspension polymerization of styrene monomers.
  • a polymerization vessel provided with a stirring blade is preferably used.
  • the shape of the stirring blade is not particularly limited, and specifically, a paddle blade such as a V-shaped paddle blade, a fiddler blade, an inclined paddle blade, a flat paddle blade, a pull margin blade, a turbine blade, a fan turbine blade, etc. Examples include a turbine blade and a propeller blade such as a marine propeller blade. Of these stirring blades, paddle blades are preferred.
  • the stirring blade may be a single-stage blade or a multi-stage blade.
  • a baffle may be provided in the polymerization container.
  • the temperature of the aqueous medium when the styrene monomer is polymerized in the micropellet is not particularly limited, but is preferably in the range of ⁇ 30 to + 20 ° C. of the melting point of the polyolefin resin to be used. More specifically, 70 to 140 ° C. is preferable, and 80 to 135 ° C. is more preferable.
  • the temperature of the aqueous medium may be a constant temperature from the start to the end of the polymerization of the styrenic monomer, or may be increased stepwise. When increasing the temperature of the aqueous medium, it is preferable to increase it at a rate of temperature rise of 0.1 to 2 ° C./min.
  • the crosslinking may be performed in advance before impregnating the styrene monomer, or while impregnating and polymerizing the styrene monomer in the micropellets. Alternatively, it may be performed after impregnating and polymerizing a styrenic monomer in a micropellet.
  • crosslinking agent used for crosslinking the polyolefin resin examples include 2,2-di-t-butylperoxybutane, dicumyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxy. An organic peroxide such as hexane may be mentioned.
  • a crosslinking agent may be individual or may be used together 2 or more types. The amount of the crosslinking agent used is usually preferably 0.05 to 1.0 part by weight with respect to 100 parts by weight of the polyolefin resin particles (micropellets).
  • a method of adding a crosslinking agent for example, a method of directly adding a crosslinking agent to a polyolefin resin, a method of adding a crosslinking agent after dissolving it in a solvent, a plasticizer or a styrene monomer, and dispersing the crosslinking agent in water
  • a method of adding after adding them for example, a method of adding after adding them.
  • the method of adding after dissolving a crosslinking agent in a styrene-type monomer is preferable.
  • the ultraviolet absorber is not particularly limited, and any known ultraviolet absorber can be used. Specifically, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) Phenol, 2- [5-chloro- (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2,4-di-tert-butyl-6- (5-chloro Benzotriazoles such as benzotriazol-2-yl) phenol, benzophenones such as octabenzone, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy And UV absorbers such as triazine type and malonic ester type such as phenol. Of these, benzotriazole-based and benzophenone-based ultraviolet
  • the UV absorber is present in the impregnation system when impregnated with the foaming agent.
  • the inventors consider that the ultraviolet absorber is coated on the surface layer of the resin particles by being in contact with the resin particles while being impregnated with the foaming agent, and penetrates into the inside.
  • the amount used is preferably 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the resin particles. When the amount is less than 0.01 parts by weight, the amount of the ultraviolet absorber contained in the obtained expandable resin particles decreases, and as a result, the desired ultraviolet shielding property may not be obtained.
  • a more preferred use amount is 0.02 to 0.4 parts by weight.
  • Foaming agent Various known volatile foaming agents can be used as the foaming agent. Specific examples include hexane, normal pentane, isopentane, neopentane, industrial pentane, petroleum ether, normal butane, isobutane, propane, cyclohexane, and cyclopentane. In particular, it is preferable to use butane or pentane. Further, a foaming aid may be used.
  • foaming aids examples include solvents such as cyclohexane and d-limonene, and plasticizers (high-boiling solvents) such as diisobutyl adipate, glycerin, diacetylated monolaurate, and coconut oil.
  • the addition amount of the foaming aid is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the resin particles.
  • the impregnation with the foaming agent can be performed, for example, under pressure or normal pressure at a temperature of 30 to 140 ° C. by a method known per se for 0.5 to 6 hours.
  • a rotary mixer such as a V-type, C-type, or DC-type, in which resin particles are flowed in a sealed pressure-resistant container and a foaming agent is introduced and impregnated; And a method of impregnating and impregnating a foaming agent into a closed container after production of resin particles by polymerization.
  • the content of the foaming agent in the expandable resin particles is preferably 7.5 to 11 parts by weight with respect to 100 parts by weight of the resin particles. If the content of the foaming agent is less than 7.5 parts by weight, the foamability of the foamable resin particles may be lowered. When foamability is reduced, it becomes difficult to obtain low-bulk-density pre-expanded particles having a high bulk ratio, and the foam-molded product obtained by molding the pre-expanded particles in a mold has a lower fusion rate and is resistant to cracking. May decrease. On the other hand, when the amount exceeds 11 parts by weight, pre-expanded particles having a low bulk density of 65 times or more can be obtained.
  • a more preferable foaming agent content is in the range of 8 to 10.5 parts by weight.
  • the average particle diameter of the expandable resin particles is preferably 800 to 2400 ⁇ m.
  • the yield is poor, and as a result, the cost may increase.
  • the retention of the foaming agent tends to be reduced and the bead life tends to be shortened.
  • it exceeds 2400 ⁇ m the filling property to the mold tends to be poor when molding a foamed molded product having a complicated shape.
  • a preferable average particle diameter is 1200 to 2000 ⁇ m.
  • the pre-expanded particles can be obtained by pre-expanding the expandable resin particles to a bulk multiple of 5 to 60 times, for example. Specifically, the foamed resin particles impregnated with the foaming agent are heated using a heating medium such as water vapor as necessary to pre-foam to a predetermined bulk density to obtain pre-foamed particles. Can do.
  • the pre-expanded particles have a bulk multiple of 5 to 60 times (bulk density 0.016 to 0.2 g / cm 3 ). The preferred bulk factor is 10 to 55 times.
  • the closed cell ratio of the pre-expanded particles is lowered, and the strength of the foamed molded product obtained by foaming the pre-expanded particles may be lowered.
  • the weight of the foamed molded product obtained by foaming the pre-foamed particles may increase.
  • the foamed molded product of the present invention is obtained from expandable resin particles containing an ultraviolet absorber. Further, the foamed molded article has a light transmittance of 365% or less of light of 3% or less in a sample cut to a thickness of 5 mm from the skin. In short, this foamed molded article has a high ultraviolet shielding property in a region having a thickness of 5 mm from the skin. The transmittance is preferably 2% or less.
  • the foamed molded body is obtained by molding the pre-expanded particles into a shape of a container for transporting and / or storing electrical products selected from liquid crystal display panels, solar cells, semiconductor wafers and semiconductor devices.
  • the pre-expanded particles are filled in a mold of a molding machine, heated and subjected to secondary foaming, and the pre-expanded particles are fused and integrated to obtain a foam-molded article having a desired shape.
  • the molding machine there can be used an EPS molding machine or the like used when producing a foam molded body from polystyrene resin pre-foamed particles.
  • the electrical products are strongly required to prevent deterioration due to ultraviolet irradiation.
  • the foamed molded article of the present invention is derived from expandable resin particles in which an ultraviolet absorber is dispersed not only on the surface but also inside. For this reason, a large amount of ultraviolet light in the transmitted light is blocked on the surface of the foamed molded article, and also can be efficiently blocked by passing through the cell containing the ultraviolet absorber while being scattered inside and outside.
  • the transmittance at 350 nm / the transmittance at 500 nm ( It is possible to obtain a foamed molded article having a relationship in which the ratio A) is 1/2 or less and / or the transmittance at 350 nm / the transmittance at 800 nm (ratio B) is 1/3 or less.
  • the ratio A means that the lower the value, the harder it is to transmit light with a wavelength of 350 nm than light with a wavelength of 500 nm.
  • the ratio B means that the lower the value, the more difficult it is for light with a wavelength of 350 nm to transmit than light with a wavelength of 800 nm. That is, the lower the ratios A and B, the higher the effect of selectively blocking ultraviolet rays.
  • the ratio A is preferably in the range of 0.4 to 0, and the ratio B is preferably in the range of 0.3 to 0.
  • the shape of the foamed molded product is not particularly limited, and can be appropriately set according to the shape of the product to be transported and / or stored.
  • the foamed molded article of the present invention can not only effectively block ultraviolet rays but also has excellent impact resistance, and can withstand long-distance transportation and long-term storage.
  • ⁇ Foaming agent content of expandable resin particles Precisely weigh 5 to 20 mg of the expandable resin particles to obtain a measurement sample.
  • This measurement sample is set in a pyrolysis furnace (manufactured by Shimadzu Corporation: PYR-1A) maintained at 180 to 200 ° C., and the measurement sample is sealed and heated for 120 seconds to release the blowing agent component.
  • a chart of the blowing agent component is obtained under the following conditions using a gas chromatograph (manufactured by Shimadzu Corporation: GC-14B, detector: FID) for the released blowing agent component.
  • the foaming agent content (% by weight) in the foamable resin particles is calculated from the obtained chart.
  • Gas chromatograph measurement condition column “Shimalite 60/80 NAW” ( ⁇ 3 mm ⁇ 3 m), manufactured by Shinwa Kako Co., Ltd. Column temperature: 70 ° C Detector temperature: 110 ° C Inlet temperature: 110 ° C Carrier gas: Nitrogen carrier gas Flow rate: 60 ml / min
  • ⁇ Pre-foaming conditions 500 to 2000 g of expandable resin particles are put into a normal pressure pre-foaming machine (internal volume 50 L) preheated with steam, and air is supplied while introducing steam at a setting of about 0.02 MPa while stirring, and about 2 to It is made to foam to a predetermined bulk density (bulk multiple) in 3 minutes.
  • ⁇ Bulk multiple of pre-expanded particles The weight (a) of about 5 g of pre-expanded particles is weighed at the second decimal place. Next, weighed pre-expanded particles are placed in a 500 cm 3 graduated cylinder with a minimum memory unit of 5 cm 3 . Pre-foaming is applied to this with a circular resin plate that is slightly smaller than the diameter of the graduated cylinder, and a rod-shaped resin plate with a width of about 1.5 cm and a length of about 30 cm fixed upright at the center. Read the volume (b) of the particles. Next, the bulk multiple of the pre-expanded particles is determined by the formula (b) / (a).
  • ⁇ Multiple of foam molding> The weight (a) and volume (b) of a test piece (example 75 ⁇ 300 ⁇ 35 mm) cut out from a foamed molded product (after being molded and dried at 40 ° C. for 20 hours or more) each have three or more significant figures. Measure as follows. Next, a multiple of the foamed molded product is obtained by the formula (b) / (a).
  • Method A A sample is obtained by cutting (slicing) the foamed molded product into 50 ⁇ 50 ⁇ 5 mm (within ⁇ 1 mm) of the skin portion.
  • the UV light 1 (HLR100T-2 manufactured by SEN LIGHTTS CORP, lamp: HL100) is the light receiving unit 3 of the spectroradiometer 2 (portable spectroradiometer (MS-720 manufactured by Eihiro Seiki Co., Ltd.)).
  • the UV light 1 and the spectroradiometer 3 are installed so that the distance from the front end of the UV light 1 to the light receiving unit 3 is 90 ⁇ 5 mm.
  • 4 indicates a light source and 5 indicates a lamp cover.
  • the original radioactivity for light having a wavelength of 365 nm is measured by the spectroradiometer 1. Thereafter, the sample is mounted on the light receiving unit 3 and the transmitted radiation for the light having a wavelength of 365 nm is measured.
  • the transmittance of each sample is obtained by substituting the obtained original light radiance and the transmitted radiance of the sample into the following equation.
  • permeability in this specification means the average value of the value measured 3 times about 1 sample.
  • Transmittance (%) Sample transmitted irradiance (365nm) ⁇ Original light irradiance (365nm) x 100 If the average value of the transmittance obtained by the above calculation formula is 3.0% or less, it is judged that there is a good ultraviolet blocking property.
  • Method B The foam molded body is cut and sliced into 40 ⁇ 40 ⁇ about 1 mm (thickness) for the skin portion.
  • the transmittance of the sliced sample is measured using an ultraviolet-visible spectrophotometer (UV-2450PC manufactured by Shimadzu Corporation). Measure three or more points while changing the measurement location on one sample. Measurement conditions are a measurement wavelength range of 800 to 200 nm, a slit width of 2.0 nm, a visible light ultraviolet light source switching wavelength of 360 nm, and a halogen lamp and a deuterium lamp are used as light sources.
  • ⁇ Falling ball impact strength of foam molding> a test piece of 215 mm (length) ⁇ 40 mm (width) ⁇ 20 mm (thickness) cut out from a foamed product having a predetermined multiple is placed on a space of 150 mm between fulcrums.
  • the falling ball impact strength that is, the 50% breaking height is calculated by the following formula.
  • the test piece shall have no epidermis on all six sides.
  • H50 Hi + d [ ⁇ (i ⁇ ni) /N ⁇ 0.5]
  • Hi Test height (cm) when the height level (i) is 0 and the height at which the test piece is expected to break
  • d Height interval (cm) when the test height is raised or lowered
  • ni number of test pieces destroyed (or not destroyed) at each level
  • ⁇ 0.5 Negative when using destroyed data, positive when using non-destructed data.
  • Example 1 Manufacture of resin particles 100 parts by weight of ethylene-vinyl acetate copolymer resin particles (LV-211, made by Nippon Polyethylene Co., Ltd., melt flow rate 0.3 g / 10 min, vinyl acetate content 6.2% by weight), 0.3 parts by weight of calcium silicate, 0.1 part by weight of calcium stearate was added and kneaded uniformly with an extruder. The kneaded product was granulated pellets by an underwater cutting method (the ethylene-vinyl acetate copolymer resin particles were adjusted to 80 mg per 100 particles).
  • LV-211 ethylene-vinyl acetate copolymer resin particles
  • a mixture was obtained by adding 40 parts by weight of the above pellets, 120 parts by weight of pure water, 0.45 parts by weight of magnesium pyrophosphate, and 0.02 parts by weight of sodium dodecylbenzenesulfonate to a pressure-resistant container with a stirrer having an internal volume of 100 liters. The mixture was stirred to suspend the pellet in pure water. Next, a mixed solution obtained by dissolving 0.03 part by weight of dicumyl peroxide as a radical polymerization initiator in 20 parts by weight of styrene monomer was dropped into this suspension over 30 minutes. After maintaining for 30 minutes after dropping, the temperature of the reaction system was increased to 135 ° C., maintained for 2 hours, and then cooled to room temperature.
  • the taken-out expandable resin particles were immediately pre-expanded to a bulk multiple of 30 times with a batch type pre-expander to obtain pre-expanded particles, and then stored in a thermostatic chamber at a temperature of 23 ° C.
  • the obtained pre-expanded particles were subjected to in-mold foam molding.
  • Pre-expanded particles were introduced into a 300 mm (width) ⁇ 400 mm (length) ⁇ 30 mm (thickness) mold, and 0.7 kgf / cm 2 of water vapor was introduced for 30 seconds and heated. After the heating, cooling was performed until the foaming pressure of the foamed molded product decreased to 0.05 kgf / cm 2 or less, and a foamed molded product with a multiple of 30 times was taken out. The removed foamed molded product was allowed to stand in an atmosphere of 35 ° C. for 6 hours or more.
  • Table 1 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the detected amount of the ultraviolet absorber. Show.
  • Example 2 The same procedure as in Example 1 was performed except that octabenzone (CHIMASORB 81 manufactured by Ciba Specialty Chemicals) was used as the ultraviolet absorber. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance
  • octabenzone CHIMASORB 81 manufactured by Ciba Specialty Chemicals
  • Example 3 Example 1 except that 2- (2H-benzotriazol-2-yl) -4,6-di-tert-pentylphenol (TINUVIN 328 manufactured by Ciba Specialty Chemicals) was used as the UV absorber. Went to. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance
  • Example 4 As in Example 1, except that 2- (2H-benzotriazol-2-yl) -6-dodecyl-4-methylphenol (TINUVIN 571 manufactured by Ciba Specialty Chemicals) was used as the UV absorber. It was. Content of the foaming agent in the obtained expandable resin particle was 9.0 weight part. Moreover, the transmittance
  • Example 5 The same procedure as in Example 1 was performed except that the impregnation with the foaming agent and the ultraviolet absorber was performed in a wet manner as follows. Content of the foaming agent in the obtained expandable resin particle was 8.5 weight part. Moreover, the transmittance
  • Comparative Example 1 The same procedure as in Example 1 was performed except that no ultraviolet absorber was added. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance
  • Comparative Example 2 The same procedure as in Comparative Example 1 was performed except that the foaming agent was impregnated in a wet manner as in Example 5. Content of the foaming agent in the obtained expandable resin particle was 8.6 weight part. Moreover, the transmittance
  • Example 6 The same procedure as in Example 1 was performed except that the addition amount of the ultraviolet absorber was 0.05 parts by weight. Content of the foaming agent in the obtained expandable resin particle was 8.8 weight part. Moreover, the transmittance
  • Example 7 The same procedure as in Example 1 was performed except that the addition amount of the ultraviolet absorber was 0.05 parts by weight.
  • the content of the foaming agent in the obtained expandable resin particles was 9.2 parts by weight.
  • permeability of the skin part of the obtained foaming molding was measured, and a result is shown in FIG. Further, Table 2 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the UV absorber detection amount. .
  • Example 8 The same operation as in Example 1 was performed except that the addition amount of the ultraviolet absorber was 0.02 part by weight. Content of the foaming agent in the obtained expandable resin particle was 9.0 weight part. Moreover, the transmittance
  • Example 9 The same operation as in Example 1 was performed except that the addition amount of the ultraviolet absorber was 0.005 part by weight. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance
  • Example 10 The same operation as in Example 5 was performed except that the addition amount of the ultraviolet absorber was 0.02 part by weight. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance
  • Example 11 The same procedure as in Example 1 was performed except that the bulk magnification of the pre-expanded particles and the magnification of the foamed molded product were 15 times. Content of the foaming agent in the obtained expandable resin particle was 8.8 weight part. Table 3 shows the transmittance according to Method A and the falling ball impact value.
  • Example 12 Manufacture of resin particles
  • LLDPE linear low density polyethylene resin
  • NF-444A metallocene catalyst
  • melt flow rate (MI) 2.0 g / 10 min. Density: 0.912 g / cm 3
  • MI melt flow rate
  • a dispersion medium was obtained by dispersing 0.8 parts by weight of magnesium pyrophosphate and 0.02 parts by weight of sodium dodecylbenzenesulfonate in 100 parts by weight of water in a pressure-resistant container equipped with a stirrer having an internal volume of 100 liters. 100 parts by weight of the polyethylene resin particles were dispersed in a dispersion medium to obtain a suspension.
  • 0.2 parts by weight of dicumyl peroxide as a polymerization initiator was previously dissolved in 100 parts by weight of styrene monomer to obtain a first styrene monomer solution.
  • the temperature of the suspension was adjusted to 60 ° C., and the first styrene monomer solution was quantitatively added to the suspension over 30 minutes. Then, it stirred at 60 degreeC for 1 hour, and impregnated the styrene monomer in the polyethylene-type resin particle.
  • the temperature of the dispersion was raised to 130 ° C., and the temperature was maintained at 130 ° C. for 2 hours to polymerize the styrene monomer in the polyethylene resin particles.
  • Expandable resin particles were obtained in the same manner as in Example 1 except that the amount of diisobutyl adipate was 0.9 parts by weight, the amount of butane was 18 parts by weight, and no aliphatic quaternary ammonium salt was used. Content of the foaming agent in the obtained expandable resin particle was 9.1 weight part.
  • the foamed resin particles were prefoamed in the same manner as in Example 1 to obtain prefoamed particles having a bulk multiple of 50 times, and then stored in a thermostatic chamber at a temperature of 23 ° C.
  • In-mold foam molding was carried out in the same manner as in Example 1 to obtain a foam molded article having a multiple of 50 times. Table 3 shows the transmittance according to Method A and the falling ball impact value.
  • Example 13 The same operation as in Example 12 was performed except that the addition amount of the ultraviolet absorber was 0.02 part by weight. Content of the foaming agent in the obtained expandable resin particle was 9.1 weight part. Table 3 shows the transmittance according to Method A and the falling ball impact value.
  • Example 14 Manufacture of resin particles
  • a dispersion liquid was obtained by supplying 40000 parts by weight of water, 100 parts by weight of tricalcium phosphate and 2.0 parts by weight of calcium dodecylbenzenesulfonate to a polymerization vessel equipped with a stirrer having an internal volume of 100 liters.
  • 40000 parts by weight of styrene monomer, 96.0 parts by weight of benzoyl peroxide and 28.0 parts by weight of t-butyl peroxybenzoate were added to the dispersion under stirring.
  • the temperature was raised to 90 ° C. to polymerize the styrene monomer. And it hold
  • Polystyrene resin particles (A) were obtained by cooling to room temperature 2 hours after raising the temperature. By sieving the polystyrene resin particles (A), polystyrene resin particles (B) having a particle diameter of 0.5 to 0.71 mm were obtained as seed particles.
  • Pre-foaming and foaming It carried out similarly to Example 1 except using the said expandable resin particle. Content of the foaming agent in the obtained expandable resin particle was 8.5 weight part. Table 3 shows the transmittance according to Method A and the falling ball impact value.
  • ⁇ , ⁇ , and ⁇ in the evaluation results are based on the following criteria. That is, it is desirable that the foamed molded product has both ultraviolet shielding properties and a falling ball impact value. Therefore, in this specification, it is defined that the ultraviolet shielding property preferably satisfies the following condition (I), and the falling ball impact value preferably satisfies the following condition (II).
  • Condition (II): Falling ball impact value is 35 cm or more ⁇ , ⁇ and ⁇ are from the viewpoint of conditions (I) and (II) Examples and comparative examples are evaluated as follows.
  • EVA is ethylene-vinyl acetate Copolymer
  • PS means polystyrene
  • mLLDPE means non-crosslinked linear low density polyethylene resin by metallocene catalyst.
  • Examples 1 to 4 it can be seen from Examples 1 to 4 that even when the ultraviolet absorbent is changed, the ultraviolet shielding property of the foamed molded article obtained from the foamable resin particles as a raw material is improved.
  • an ultraviolet absorber has been dispersed in resin particles by kneading with a resin that requires a relatively high temperature.
  • the ultraviolet absorbent is impregnated in the resin in the foaming agent impregnation step performed at a low temperature of 50 to 70 ° C. Therefore, it turns out that the foaming molding which can interrupt
  • the foam molded articles obtained in Examples 1 to 14 have a falling ball impact strength that can be sufficiently applied to containers for transporting and storing electrical products.
  • FIG. 8A is a graph showing the irradiance for each wavelength of the UV light used in Method A, and FIG.
  • FIG. 8 is a graph showing the irradiance for each wavelength of the foam molded articles of Example 1 and Comparative Example 1. Shown in (b). In FIG. 8B, the dotted line indicates Example 1 and the solid line indicates Comparative Example 1. FIG. 8B shows that the foamed molded product of Example 1 can significantly shield light having a wavelength of around 365 nm.

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Abstract

A process for the production of foam-molded articles, which comprises: a step of preparing expandable resin particles by bringing starting resin particles (which can form expandable resin particles) into contact with an ultraviolet absorber when impregnating the starting resin particles with a blowing agent; a step of pre-expanding the expandable resin particles to form pre-expanded beads; and a step of molding the pre-expanded beads by an in-mold expansion molding method into a shape corresponding to a transport or storage container for an electrical product selected from among liquid-crystal display panels, solar cells, semiconductor wafers and semiconductor devices. The foam-molded articles obtained by the process have ultraviolet -screening properties.

Description

発泡成形体及びその製造方法Foam molded body and method for producing the same
　本発明は、発泡成形体及びその製造方法に関する。更に詳しくは、本発明は、紫外線吸収機能が付与された発泡成形体及びその製造方法に関する。本発明の発泡成形体は、紫外線によりダメージを受けることがある液晶表示パネル、太陽電池セル、半導体ウェハ及び半導体装置から選択される電気製品を輸送及び／又は保管する容器に適している。 The present invention relates to a foam molded article and a method for producing the same. More specifically, the present invention relates to a foamed molded article having an ultraviolet absorbing function and a method for producing the same. The foamed molded product of the present invention is suitable for a container for transporting and / or storing an electrical product selected from a liquid crystal display panel, a solar battery cell, a semiconductor wafer, and a semiconductor device that may be damaged by ultraviolet rays.
　種々の製品又はその部品が、輸送や保管時の破損から保護するために、容器に入れられている。そのような容器には、通常樹脂製の容器が使用され、特に衝撃に対して緩衝性を有する発泡成形体が好適に使用される。
　ところで、製品の場合、その製造場所と販売場所が離れていることがあり、部品の場合、部品の製造場所と、その部品を製品に組み込む場所が離れていることがある。近年、経済のグローバル化に伴って、それら場所が国境を越えることがある。そのため製品又は部品の輸送や保管が長期間に及ぶことがある。例えば、液晶表示パネル、太陽電池セル、半導体ウェハ及び半導体装置等の電気製品は、紫外線の照射により劣化することが知られている。輸送や保管が長期間に及ぶ場合、紫外線に電気機器が晒される機会が増えることになる。従って、容器には、優れた衝撃に対する緩衝性に加えて、輸送時や保管時に晒される紫外線に対する遮蔽性が求められている。 Various products or parts thereof are placed in containers to protect them from damage during transportation and storage. As such a container, a resin container is usually used, and a foamed molded article having a shock-absorbing property is particularly preferably used.
By the way, in the case of a product, the manufacturing place and the sales place may be separated from each other, and in the case of a part, the part manufacturing place and the place where the part is incorporated into the product may be separated from each other. In recent years, with the globalization of the economy, these places may cross borders. Therefore, transportation or storage of products or parts may take a long time. For example, it is known that electrical products such as liquid crystal display panels, solar cells, semiconductor wafers, and semiconductor devices are deteriorated by irradiation with ultraviolet rays. When transportation and storage are carried out for a long period of time, the chances of electrical equipment being exposed to ultraviolet light will increase. Therefore, in addition to excellent shock-absorbing properties, containers are required to have shielding properties against ultraviolet rays that are exposed during transportation and storage.
　紫外線吸収剤を付与した発泡成形体を製造するために、樹脂成分に予め紫外線吸収剤を存在させる方法を検討した文献として、特開２００２－１５５１６１号公報（特許文献１）が挙げられる。この文献では、樹脂成分と紫外線吸収剤との混合を押出機で行い、押出されたペレットに発泡剤を含浸させて発泡性樹脂粒子を得ている。 Japanese Patent Application Laid-Open No. 2002-155161 (Patent Document 1) is cited as a literature for examining a method in which an ultraviolet absorber is preliminarily present in a resin component in order to produce a foamed molded article provided with an ultraviolet absorber. In this document, the resin component and the ultraviolet absorber are mixed by an extruder, and the foamed resin particles are obtained by impregnating the extruded pellets with a foaming agent.
特開２００２－１５５１６１号公報JP 2002-155161 A
　上記公報は、紫外線吸収剤を耐候性の向上を目的として使用している。また、紫外線吸収剤は、押出機により樹脂成分と混合されている。そのため、得られる発泡成形体は、ある程度の紫外線を遮蔽できる。しかし、効率よく、簡易に紫外線吸収剤を樹脂成分に混合でき、紫外線遮蔽性を更に向上させるとともに、耐衝撃性を兼ね備えた発泡成形体及びその製造方法の提供が求められていた。 The above publication uses an ultraviolet absorber for the purpose of improving the weather resistance. Moreover, the ultraviolet absorber is mixed with the resin component by an extruder. Therefore, the foamed molded product obtained can shield a certain amount of ultraviolet rays. However, it has been demanded to provide a foamed molded article that can efficiently and easily mix an ultraviolet absorbent with a resin component, further improve ultraviolet shielding properties, and also has impact resistance, and a method for producing the same.
　樹脂粒子の製造方法としては、例えば、押出法、懸濁重合法、乳化重合法等の種々の方法が知られている。本発明者等は、紫外線吸収剤の添加時期について検討した結果、紫外線吸収剤の添加時期を、樹脂粒子の製造時ではなく、発泡剤の含浸時にすることで、高い次元で紫外線の遮蔽性と耐衝撃性とを兼ね備えた発泡成形体が得られることを意外にも見出し、本発明に至った。 As the method for producing resin particles, various methods such as an extrusion method, a suspension polymerization method, and an emulsion polymerization method are known. As a result of examining the addition timing of the ultraviolet absorber, the present inventors have determined that the addition timing of the ultraviolet absorber is not at the time of production of the resin particles but at the impregnation of the foaming agent, so that the ultraviolet shielding property can be obtained at a high level. Surprisingly, it was found that a foamed molded article having both impact resistance and the present invention was obtained.
　かくして本発明によれば、発泡性樹脂粒子となりうる樹脂粒子と紫外線吸収剤を、発泡剤の含浸時に接触させることにより発泡性樹脂粒子を得
　次いで前記発泡性樹脂粒子を予備発泡させて予備発泡粒子を得、
　更に、前記予備発泡粒子を、液晶表示パネル、太陽電池セル、半導体ウェハ及び半導体装置から選択される電気製品の輸送・保管容器に対応する形状に型内成形させることにより、紫外線遮蔽性を有する発泡成形体を得る工程からなる発泡成形体の製造方法が提供される。
　また、本発明によれば、紫外線吸収剤を含む発泡性樹脂粒子から得られる発泡成形体であり、
　前記発泡成形体は、その表皮から５ｍｍの厚さにカットされた試料において、３％以下の３６５ｎｍの波長の光の透過率を有する液晶表示パネル、太陽電池セル、半導体ウェハ及び半導体装置から選択される電気製品の輸送・保管容器用の発泡成形体が提供される。 Thus, according to the present invention, expandable resin particles are obtained by contacting resin particles that can become expandable resin particles and an ultraviolet absorber when impregnated with the foaming agent, and then the expanded resin particles are pre-expanded to be pre-expanded particles. And
Further, the pre-expanded particles are molded in-mold into a shape corresponding to a transport / storage container for electrical products selected from liquid crystal display panels, solar cells, semiconductor wafers and semiconductor devices. There is provided a method for producing a foamed molded product comprising a step of obtaining a molded product.
Moreover, according to the present invention, a foam molded article obtained from expandable resin particles containing an ultraviolet absorber,
The foamed molded product is selected from a liquid crystal display panel, a solar battery cell, a semiconductor wafer, and a semiconductor device having a transmittance of light having a wavelength of 365 nm of 3% or less in a sample cut to a thickness of 5 mm from the skin. An expanded molded article for a container for transporting and storing electrical products is provided.
　本発明によれば、樹脂粒子と紫外線吸収剤の接触時期を、発泡剤の含浸時とすることで、簡易に効率よく紫外線吸収剤を樹脂粒子に吸収させることができる。従って、本発明によれば、紫外線の遮蔽性と耐衝撃性とを兼ね備えた発泡成形体を得ることができる。
　また、紫外線吸収剤が、ベンゾトリアゾール系又はベンゾフェノン系の紫外線吸収剤であり、樹脂粒子１００重量部に対して、０．０１～０．５重量部使用された場合、より紫外線の遮蔽性を向上した発泡成形体を得ることができる。
　更に、樹脂粒子が、ポリオレフィン系樹脂とポリスチレン系樹脂を含む樹脂粒子である場合、ビーズライフを改善するためにポリスチレン系樹脂成分を増やしても、紫外線の遮蔽性を維持しつつ、耐衝撃性及び耐割れ性に優れた発泡成形体を得ることができる。 According to the present invention, the ultraviolet absorbent can be easily and efficiently absorbed into the resin particles by setting the contact timing of the resin particles and the ultraviolet absorbent at the time of impregnation with the foaming agent. Therefore, according to the present invention, it is possible to obtain a foamed molded article having both ultraviolet shielding properties and impact resistance.
Further, when the ultraviolet absorber is a benzotriazole-based or benzophenone-based ultraviolet absorber and is used in an amount of 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the resin particles, the ultraviolet shielding property is further improved. A foamed molded product can be obtained.
Furthermore, when the resin particles are resin particles containing a polyolefin resin and a polystyrene resin, even if the polystyrene resin component is increased in order to improve the bead life, the impact resistance and A foamed molded article having excellent crack resistance can be obtained.
　また更に、樹脂粒子が、ポリオレフィン系樹脂１００重量部とポリスチレン系樹脂１２０～５６０重量部とを含む樹脂粒子である場合、紫外線の遮蔽性を維持しつつ、耐衝撃性及び耐割れ性を高い次元で両立可能な発泡成形体を得ることができる。
　本発明の発泡成形体は、高い次元で紫外線の遮蔽性と耐衝撃性とを兼ね備えているため、液晶表示パネル、太陽電池セル、半導体ウェハ及び半導体装置から選択される電気製品の輸送・保管容器として有用である。 Furthermore, when the resin particles are resin particles containing 100 parts by weight of a polyolefin resin and 120 to 560 parts by weight of a polystyrene resin, the impact resistance and crack resistance are high while maintaining ultraviolet shielding properties. A foamed molded body compatible with the above can be obtained.
The foamed molded product of the present invention has a high level of both UV shielding and impact resistance, and therefore a container for transporting and storing electrical products selected from liquid crystal display panels, solar cells, semiconductor wafers and semiconductor devices. Useful as.
実施例１の発泡成形体への照射光の波長と透過率の関係を表すグラフである。It is a graph showing the relationship between the wavelength of the irradiation light to the foaming molding of Example 1, and the transmittance | permeability. 実施例２の発泡成形体への照射光の波長と透過率の関係を表すグラフである。It is a graph showing the relationship between the wavelength of the irradiation light to the foaming molding of Example 2, and the transmittance | permeability. 実施例３の発泡成形体への照射光の波長と透過率の関係を表すグラフである。It is a graph showing the relationship between the wavelength of the irradiation light to the foaming molding of Example 3, and the transmittance | permeability. 実施例４の発泡成形体への照射光の波長と透過率の関係を表すグラフである。It is a graph showing the relationship between the wavelength of the irradiation light to the foaming molding of Example 4, and the transmittance | permeability. 比較例１の発泡成形体への照射光の波長と透過率の関係を表すグラフである。It is a graph showing the relationship between the wavelength of the irradiation light to the foaming molding of the comparative example 1, and the transmittance | permeability. 実施例７の発泡成形体への照射光の波長と透過率の関係を表すグラフである。It is a graph showing the relationship between the wavelength of the irradiation light to the foaming molding of Example 7, and the transmittance | permeability. 発泡成形体の紫外線の透過率の測定装置の概略図である。It is the schematic of the measuring apparatus of the transmittance | permeability of the ultraviolet-ray of a foaming molding. ＵＶライト、実施例１及び比較例１の発泡成形体の波長毎の放射度を示すグラフである。It is a graph which shows the irradiance for every wavelength of the foaming body of UV light and Example 1 and Comparative Example 1.
　本発明の発泡成形体の製造方法では、樹脂粒子と紫外線吸収剤を、発泡剤の含浸時に接触させることで得られた発泡性樹脂粒子が使用される。ここで、紫外線吸収剤の樹脂粒子への接触は、発泡剤の含浸時に、紫外線吸収剤が樹脂粒子の周辺に存在することにより行われる。紫外線吸収剤は、発泡剤の含浸時と同時に添加してもよく、発泡剤の含浸前の予め樹脂粒子の存在する系に添加してもよい。
　（発泡性樹脂粒子）
　　（１）樹脂粒子
　樹脂粒子は、発泡性樹脂粒子となりうる粒子、言い換えると、発泡剤を含浸可能な粒子であれば特に限定されない。例えば、ポリオレフィン系樹脂、ポリスチレン系樹脂、これら樹脂の混合物等の樹脂成分からなる樹脂粒子が挙げられる。更に、樹脂成分には、本発明の効果を妨げない範囲で、ゴム成分（ポリブタジエン、ブタジエン－スチレン共重合体等）が含まれていてもよい。 In the method for producing a foamed molded article of the present invention, expandable resin particles obtained by bringing resin particles and an ultraviolet absorber into contact with each other at the time of impregnation with the foaming agent are used. Here, the contact of the ultraviolet absorbent with the resin particles is performed by the presence of the ultraviolet absorbent around the resin particles when the foaming agent is impregnated. The ultraviolet absorber may be added simultaneously with the impregnation of the foaming agent, or may be added to a system in which resin particles are present before the impregnation of the foaming agent.
(Expandable resin particles)
(1) Resin particles The resin particles are not particularly limited as long as they are particles that can become expandable resin particles, in other words, particles that can be impregnated with a foaming agent. For example, the resin particle which consists of resin components, such as polyolefin resin, polystyrene resin, and the mixture of these resin, is mentioned. Furthermore, the resin component may contain a rubber component (polybutadiene, butadiene-styrene copolymer, etc.) as long as the effects of the present invention are not hindered.
　ポリオレフィン系樹脂としては、特に限定されず、公知の樹脂が使用できる。また、ポリオレフィン系樹脂は、架橋していてもよい。例えば、分岐状低密度ポリエチレン、直鎖状低密度ポリエチレン、中密度ポリエチレン、高密度ポリエチレン、エチレン－酢酸ビニル共重合体、エチレン－メチルメタクリレート共重合体、これら重合体の架橋体等のポリエチレン系樹脂、プロピレン単独重合体、エチレン－プロピレンランダム共重合体、プロピレン－１－ブテン共重合体、エチレン－プロピレン－ブテンランダム共重合体等のポリプロピレン系樹脂が挙げられる。上記例示中、低密度は、０．９１～０．９４ｇ／ｃｍ3であることが好ましく、０．９１～０．９３ｇ／ｃｍ3であることがより好ましい。高密度は、０．９５～０．９７ｇ／ｃｍ3であることが好ましく、０．９５～０．９６ｇ／ｃｍ3であることがより好ましい。中密度はこれら低密度と高密度の中間の密度である。 It does not specifically limit as polyolefin-type resin, A well-known resin can be used. The polyolefin resin may be cross-linked. For example, polyethylene resins such as branched low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-methyl methacrylate copolymer, and cross-linked products of these polymers And polypropylene resins such as propylene homopolymer, ethylene-propylene random copolymer, propylene-1-butene copolymer, and ethylene-propylene-butene random copolymer. In the above example, the low density is preferably 0.91 ~ 0.94g / cm 3, more preferably 0.91 ~ 0.93g / cm 3. The high density is preferably 0.95 to 0.97 g / cm 3 , and more preferably 0.95 to 0.96 g / cm 3 . The medium density is an intermediate density between these low density and high density.
　ポリスチレン系樹脂としては、ポリスチレン、もしくはスチレンを主成分とし、スチレンと共重合可能な他のモノマーとの共重合体である。主成分とはスチレンが全モノマーの７０重量％以上を占めることを意味する。他のモノマーとしては、α－メチルスチレン、ｐ－メチルスチレン、アクリロニトリル、メタクリロニトリル、アクリル酸、メタクリル酸、アクリル酸アルキルエステル、メタクリル酸アルキルエステル、ジビニルベンゼン、ポリエチレングリコールジメタクリレート等が例示される。例示中、アルキルとは、炭素数１～８のアルキルを意味する。 Polystyrene resin is polystyrene or a copolymer of styrene as a main component and other monomers copolymerizable with styrene. The main component means that styrene accounts for 70% by weight or more of the total monomers. Examples of other monomers include α-methylstyrene, p-methylstyrene, acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid, alkyl acrylate ester, alkyl methacrylate ester, divinylbenzene, polyethylene glycol dimethacrylate, and the like. . In the examples, alkyl means alkyl having 1 to 8 carbon atoms.
　樹脂成分は、ポリオレフィン系樹脂とポリスチレン系樹脂とを同時に含むことが好ましい。この場合、使用されるポリオレフィン系樹脂としては、分岐状低密度ポリエチレン、直鎖状低密度ポリエチレン又はエチレン－酢酸ビニル共重合体が好ましく、ポリスチレン系樹脂は、ポリスチレン、スチレン－アクリル酸アルキルエステル共重合体又はスチレン－メクリル酸アルキルエステル共重合体であることが好ましい。 The resin component preferably contains a polyolefin resin and a polystyrene resin at the same time. In this case, the polyolefin resin used is preferably a branched low density polyethylene, a linear low density polyethylene or an ethylene-vinyl acetate copolymer, and the polystyrene resin is a polystyrene, styrene-alkyl acrylate copolymer copolymer. A polymer or a styrene-methacrylic acid alkyl ester copolymer is preferred.
　ポリスチレン系樹脂は、樹脂粒子中、ポリオレフィン系樹脂粒子１００重量部に対して１２０～５６０重量部の範囲で含まれることが好ましい。
　ポリスチレン系樹脂の含有量が５６０重量部より多いと、発泡成形体の耐割れ性が低下することがある。一方、１２０重量部より少ないと、耐割れ性は大幅に向上するが、発泡性樹脂粒子の表面からの発泡剤の逸散が速くなる傾向がある。そのため、発泡剤の保持性が低下することによって発泡性樹脂粒子のビーズライフが短くなることがある。より好ましいポリスチレン系樹脂の含有量は１４０～４５０重量部、更に好ましい含有量は１５０～４００重量部である。 The polystyrene resin is preferably contained in the resin particles in the range of 120 to 560 parts by weight with respect to 100 parts by weight of the polyolefin resin particles.
When there is more content of a polystyrene-type resin than 560 weight part, the crack resistance of a foaming molding may fall. On the other hand, if it is less than 120 parts by weight, the cracking resistance is greatly improved, but the dissipation of the foaming agent from the surface of the expandable resin particles tends to be accelerated. Therefore, the bead life of the expandable resin particles may be shortened due to a decrease in the retention of the foaming agent. A more preferable content of the polystyrene resin is 140 to 450 parts by weight, and a more preferable content is 150 to 400 parts by weight.
　ポリオレフィン系樹脂とポリスチレン系樹脂とを同時に含ませる方法としては、例えば、両樹脂を押出機中で混練する方法、ポリオレフィン系樹脂からなる粒子に、水性媒体中で、スチレン系モノマーを含浸させ、次いでそのモノマーを重合させる方法等が挙げられる。この内、後者の方法は、より均一に両樹脂を混合でき、かつより球形に近い粒子が得られる観点から好ましい。ここで、後者の方法により得られた樹脂粒子をポリオレフィンとポリスチレンからなる複合樹脂粒子と称する。
　以下では、上記後者の方法を説明する。 Examples of the method of simultaneously including a polyolefin resin and a polystyrene resin include, for example, a method of kneading both resins in an extruder, impregnating particles made of a polyolefin resin with an styrene monomer in an aqueous medium, Examples thereof include a method of polymerizing the monomer. Among these, the latter method is preferable from the viewpoint of more uniformly mixing both resins and obtaining particles having a more spherical shape. Here, the resin particles obtained by the latter method are referred to as composite resin particles made of polyolefin and polystyrene.
Hereinafter, the latter method will be described.
　まず、原料としてのポリオレフィン系樹脂粒子は、公知の方法で得ることができる。例えば、まず、押出機を使用してポリオレフィン系樹脂を溶融押出した後、水中カット、ストランドカット等により造粒することで、ポリオレフィン系樹脂粒子を作製できる。通常、使用するポリオレフィン系樹脂の形状は、例えば、真球状、楕円球状（卵状）、円柱状、角柱状、ペレット状又はグラニュラー状である。以下では、ポリオレフィン系樹脂粒子をマイクロペレットとも記す。 First, polyolefin resin particles as a raw material can be obtained by a known method. For example, polyolefin resin particles can be prepared by first melt-extruding a polyolefin resin using an extruder and then granulating it by underwater cutting, strand cutting, or the like. Usually, the shape of the polyolefin resin to be used is, for example, a true sphere, an oval (egg), a column, a prism, a pellet, or a granular. Hereinafter, the polyolefin resin particles are also referred to as micropellets.
　ポリオレフィン系樹脂には、ラジカル補足剤が含まれていてもよい。ラジカル捕捉剤は、予めポリオレフィン系樹脂に添加しておくか、もしくは溶融押出と同時に添加してもよい。ラジカル補足剤としては、重合禁止剤（重合抑制剤を含む）、連鎖移動剤、酸化防止剤、ヒンダードアミン系光安定剤等のラジカルを捕捉する作用を有する化合物で、水に溶解し難いものが好ましい。
　ラジカル補足剤の使用量としては、ポリオレフィン系樹脂１００重量部に対して０．００５～０．５重量部であることが好ましい。 The polyolefin resin may contain a radical scavenger. The radical scavenger may be added to the polyolefin resin in advance, or may be added simultaneously with melt extrusion. The radical scavenger is preferably a compound having an action of scavenging radicals such as a polymerization inhibitor (including a polymerization inhibitor), a chain transfer agent, an antioxidant, a hindered amine light stabilizer, and the like, which is hardly soluble in water. .
The amount of the radical scavenger used is preferably 0.005 to 0.5 parts by weight with respect to 100 parts by weight of the polyolefin resin.
　ポリオレフィン系樹脂粒子は、他に、タルク、珪酸カルシウム、ステアリン酸カルシウム、合成あるいは天然に産出される二酸化ケイ素、エチレンビスステアリン酸アミド、メタクリル酸エステル系共重合体等の発泡核剤、トリアリルイソシアヌレート６臭素化物等の難燃剤、カーボンブラック、酸化鉄、グラファイト等の着色剤等を含んでいてもよい。
　次に、ポリオレフィン系樹脂粒子を重合容器内の水性媒体中に分散させ、スチレン系モノマーをポリオレフィン系樹脂粒子に含浸させながら重合させる。
　水性媒体としては、水、水と水溶性溶媒（例えば、アルコール）との混合媒体が挙げられる。 Polyolefin resin particles include talc, calcium silicate, calcium stearate, foamed nucleating agents such as synthetic or naturally produced silicon dioxide, ethylenebisstearic acid amide, methacrylic acid ester copolymer, triallyl isocyanurate A flame retardant such as hexabromide and a colorant such as carbon black, iron oxide and graphite may be included.
Next, the polyolefin resin particles are dispersed in an aqueous medium in a polymerization vessel and polymerized while impregnating the polyolefin resin particles with a styrene monomer.
Examples of the aqueous medium include water and a mixed medium of water and a water-soluble solvent (for example, alcohol).
　スチレン系モノマーは、スチレン及び置換スチレン（置換基には、低級アルキル、ハロゲン原子（特に塩素原子）等が含まれる）のいずれも使用できる。また、スチレン系モノマーは、スチレンと、置換スチレンとの混合物、スチレンと共重合可能な少量の他のモノマー（例えば、アクリロニトリル、メタクリル酸アルキルエステル（アルキル部分の炭素数１～８程度）、マレイン酸モノないしジアルキル（アルキル部分の炭素数１～４程度）、ジビニルベンゼン、エチレングリコールのモノないしジアクリル酸ないしメタクリル酸エステル、無水マレイン酸、Ｎ－フェニルマレイド等）との混合物が使用できる。これら混合物中、スチレンが優位量（例えば、５０重量％以上）を占めることが好ましい。
　なお、スチレン系モノマーには、トルエン、キシレン、シクロヘキサン、酢酸エチル、アジピン酸ジオクチル、等の溶剤（可塑剤）を添加してもよい。 As the styrenic monomer, any of styrene and substituted styrene (substituent includes lower alkyl, halogen atom (especially chlorine atom) and the like) can be used. The styrenic monomer is a mixture of styrene and substituted styrene, a small amount of other monomers copolymerizable with styrene (for example, acrylonitrile, alkyl methacrylate (about 1 to 8 carbon atoms in the alkyl portion), maleic acid, and the like. Mixtures with mono to dialkyl (alkyl group having about 1 to 4 carbon atoms), divinylbenzene, ethylene glycol mono to diacrylic acid or methacrylic acid ester, maleic anhydride, N-phenylmaleide and the like can be used. In these mixtures, styrene preferably occupies a dominant amount (for example, 50% by weight or more).
A solvent (plasticizer) such as toluene, xylene, cyclohexane, ethyl acetate, dioctyl adipate may be added to the styrene monomer.
　ポリオレフィン系樹脂粒子へのスチレン系モノマーの含浸は、重合させつつ行ってもよく、重合を開始する前に行ってもよい。この内、重合させつつ行うことが好ましい。なお、含浸させた後に重合を行う場合、ポリオレフィン系樹脂粒子の表面近傍でのスチレン系モノマーの重合が起こり易い。また、ポリオレフィン系樹脂粒子中に含浸されなかったスチレン系モノマーが単独で重合し易い。その結果、多量の微粒子状のポリスチレン系樹脂粒子が生成する場合がある。 The impregnation of the polyolefin resin particles with the styrene monomer may be performed while polymerizing, or may be performed before the polymerization is started. Of these, it is preferable to carry out the polymerization. In addition, when superposing | polymerizing after making it impregnate, superposition | polymerization of the styrene-type monomer near the surface of polyolefin resin particle occurs easily. In addition, the styrene monomer not impregnated in the polyolefin resin particles is easily polymerized alone. As a result, a large amount of fine particle polystyrene resin particles may be generated.
　スチレン系モノマーの重合には、油溶性のラジカル重合開始剤を使用できる。この重合開始剤としては、スチレン系モノマーの重合に汎用されている重合開始剤を使用できる。
　重合開始剤を重合容器内の水性媒体に添加する方法としては、種々の方法が挙げられる。例えば、
（１）重合容器とは別の容器内でスチレン系モノマーに重合開始剤を溶解して含有させ、このスチレン系モノマーを重合容器内に供給する方法、
（２）重合開始剤をスチレン系モノマーの一部、イソパラフィン等の溶剤又は可塑剤に溶解させて溶液を作製する。この溶液と、所定量のスチレン系モノマーとを重合容器内に同時に供給する方法、
（３）重合開始剤を水性媒体に分散させた分散液を作製する。この分散液とスチレン系モノマーとを重合容器内に供給する方法
等が挙げられる。
　上記重合開始剤の使用量は、通常スチレン系モノマーの使用総量の０．０２～２．０重量％添加することが好ましい。 An oil-soluble radical polymerization initiator can be used for the polymerization of the styrene monomer. As this polymerization initiator, a polymerization initiator generally used for the polymerization of styrene monomers can be used.
Various methods can be used as a method of adding the polymerization initiator to the aqueous medium in the polymerization vessel. For example,
(1) A method in which a polymerization initiator is dissolved and contained in a styrene monomer in a container different from the polymerization container, and the styrene monomer is supplied into the polymerization container.
(2) A solution is prepared by dissolving a polymerization initiator in a part of a styrene monomer, a solvent such as isoparaffin or a plasticizer. A method of simultaneously supplying this solution and a predetermined amount of styrenic monomer into the polymerization vessel,
(3) A dispersion in which a polymerization initiator is dispersed in an aqueous medium is prepared. Examples thereof include a method of supplying the dispersion and the styrene monomer into a polymerization vessel.
The polymerization initiator is preferably added in an amount of 0.02 to 2.0% by weight based on the total amount of styrene monomer used.
　水性媒体中には、水溶性のラジカル重合禁止剤を溶解させておくことが好ましい。水溶性のラジカル重合禁止剤はポリオレフィン系樹脂粒子表面におけるスチレン系モノマーの重合を抑制するだけでなく、水性媒体中に浮遊するスチレン系モノマーが単独で重合するのを防止して、ポリスチレン系樹脂の微粒子の生成を減らすことができるからである。
　水溶性のラジカル重合禁止剤としては、水１００ｇに対して１ｇ以上溶解する重合禁止剤が使用できる。
　上記水溶性のラジカル重合禁止剤の使用量としては、水性媒体の水１００重量部に対して０．００１～０．０４重量部が好ましい。
　なお、上記水性媒体中に無機系分散剤等の分散剤と界面活性剤とを添加しておくことが好ましい。 It is preferable to dissolve a water-soluble radical polymerization inhibitor in the aqueous medium. The water-soluble radical polymerization inhibitor not only suppresses the polymerization of the styrene monomer on the surface of the polyolefin resin particles, but also prevents the styrene monomer floating in the aqueous medium from being polymerized alone. This is because the generation of fine particles can be reduced.
As the water-soluble radical polymerization inhibitor, a polymerization inhibitor that can dissolve 1 g or more in 100 g of water can be used.
The amount of the water-soluble radical polymerization inhibitor used is preferably 0.001 to 0.04 parts by weight with respect to 100 parts by weight of water in the aqueous medium.
In addition, it is preferable to add a dispersant such as an inorganic dispersant and a surfactant to the aqueous medium.
　重合容器の形状及び構造としては、従来からスチレン系モノマーの懸濁重合に用いられているものであれば、特に限定されない。例えば、攪拌翼を供えた重合容器が好適に使用される。
　また、攪拌翼の形状についても特に限定はなく、具体的には、Ｖ型パドル翼、ファードラー翼、傾斜パドル翼、平パドル翼、プルマージン翼等のパドル翼、タービン翼、ファンタービン翼等のタービン翼、マリンプロペラ翼のようなプロペラ翼等が挙げられる。これら攪拌翼の内では、パドル翼が好ましい。攪拌翼は、単段翼であっても多段翼であってもよい。重合容器に邪魔板（バッフル）を設けてもよい。 The shape and structure of the polymerization vessel are not particularly limited as long as they are conventionally used for suspension polymerization of styrene monomers. For example, a polymerization vessel provided with a stirring blade is preferably used.
Further, the shape of the stirring blade is not particularly limited, and specifically, a paddle blade such as a V-shaped paddle blade, a fiddler blade, an inclined paddle blade, a flat paddle blade, a pull margin blade, a turbine blade, a fan turbine blade, etc. Examples include a turbine blade and a propeller blade such as a marine propeller blade. Of these stirring blades, paddle blades are preferred. The stirring blade may be a single-stage blade or a multi-stage blade. A baffle may be provided in the polymerization container.
　また、スチレン系モノマーをマイクロペレット中にて重合させる際の水性媒体の温度は、特に限定されないが、使用するポリオレフィン系樹脂の融点の－３０～＋２０℃の範囲であることが好ましい。より具体的には、７０～１４０℃が好ましく、８０～１３５℃がより好ましい。更に、水性媒体の温度は、スチレン系モノマーの重合開始から終了までの間、一定温度であってもよいし、段階的に上昇させてもよい。水性媒体の温度を上昇させる場合には、０．１～２℃／分の昇温速度で上昇させることが好ましい。
　更に、架橋したポリオレフィン系樹脂からなる粒子を使用する場合、架橋は、スチレン系モノマーを含浸させる前に予め行なっておいてもよいし、マイクロペレット中にスチレン系モノマーを含浸、重合させている間に行なってもよいし、マイクロペレット中にスチレン系モノマーを含浸、重合させた後に行なってもよい。 The temperature of the aqueous medium when the styrene monomer is polymerized in the micropellet is not particularly limited, but is preferably in the range of −30 to + 20 ° C. of the melting point of the polyolefin resin to be used. More specifically, 70 to 140 ° C. is preferable, and 80 to 135 ° C. is more preferable. Furthermore, the temperature of the aqueous medium may be a constant temperature from the start to the end of the polymerization of the styrenic monomer, or may be increased stepwise. When increasing the temperature of the aqueous medium, it is preferable to increase it at a rate of temperature rise of 0.1 to 2 ° C./min.
Furthermore, when using particles comprising a crosslinked polyolefin resin, the crosslinking may be performed in advance before impregnating the styrene monomer, or while impregnating and polymerizing the styrene monomer in the micropellets. Alternatively, it may be performed after impregnating and polymerizing a styrenic monomer in a micropellet.
　ポリオレフィン系樹脂の架橋に用いられる架橋剤としては、例えば、２，２－ジ－ｔ－ブチルパーオキシブタン、ジクミルパーオキサイド、２，５－ジメチル－２，５－ジ－ｔ－ブチルパーオキシヘキサン等の有機過酸化物が挙げられる。なお、架橋剤は、単独でも二種以上併用してもよい。また、架橋剤の使用量は、通常、ポリオレフィン系樹脂粒子（マイクロペレット）１００重量部に対して０．０５～１．０重量部が好ましい。
　架橋剤を添加する方法としては、例えば、架橋剤をポリオレフィン系樹脂に直接添加する方法、溶剤、可塑剤又はスチレン系モノマーに架橋剤を溶解させた上で添加する方法、架橋剤を水に分散させた上で添加する方法等が挙げられる。この内、スチレン系モノマーに架橋剤を溶解させた上で添加する方法が好ましい。 Examples of the crosslinking agent used for crosslinking the polyolefin resin include 2,2-di-t-butylperoxybutane, dicumyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxy. An organic peroxide such as hexane may be mentioned. In addition, a crosslinking agent may be individual or may be used together 2 or more types. The amount of the crosslinking agent used is usually preferably 0.05 to 1.0 part by weight with respect to 100 parts by weight of the polyolefin resin particles (micropellets).
As a method of adding a crosslinking agent, for example, a method of directly adding a crosslinking agent to a polyolefin resin, a method of adding a crosslinking agent after dissolving it in a solvent, a plasticizer or a styrene monomer, and dispersing the crosslinking agent in water For example, a method of adding after adding them. Among these, the method of adding after dissolving a crosslinking agent in a styrene-type monomer is preferable.
　　（２）紫外線吸収剤
　紫外線吸収剤としては、特に限定されず、公知の紫外線吸収剤をいずれも使用できる。具体的には、２－（２Ｈ－ベンゾトリアゾール－２－イル）－ｐ－クレゾール、２－（２Ｈ－ベンゾトリアゾール－２－イル）－４，６－ビス（１－メチル－１－フェニルエチル）フェノール、２－［５－クロロ－（２Ｈ）－ベンゾトリアゾール－２－イル］－４－メチル－６－（ｔｅｒｔ－ブチル）フェノール、２，４－ジ－ｔｅｒｔ－ブチル－６－（５－クロロベンゾトリアゾール－２－イル）フェノール等のベンゾトリアゾール系、オクタベンゾンのようなベンゾフェノン系、２－（４，６－ジフェニル－１，３，５－トリアジン－２－イル）－５－［（ヘキシル）オキシ］フェノールのようなトリアジン系、マロン酸エステル系等の紫外線吸収剤が挙げられる。この中でもベンゾトリアゾール系及びベンゾフェノン系紫外線吸収剤が好ましい。 (2) Ultraviolet absorber The ultraviolet absorber is not particularly limited, and any known ultraviolet absorber can be used. Specifically, 2- (2H-benzotriazol-2-yl) -p-cresol, 2- (2H-benzotriazol-2-yl) -4,6-bis (1-methyl-1-phenylethyl) Phenol, 2- [5-chloro- (2H) -benzotriazol-2-yl] -4-methyl-6- (tert-butyl) phenol, 2,4-di-tert-butyl-6- (5-chloro Benzotriazoles such as benzotriazol-2-yl) phenol, benzophenones such as octabenzone, 2- (4,6-diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy And UV absorbers such as triazine type and malonic ester type such as phenol. Of these, benzotriazole-based and benzophenone-based ultraviolet absorbers are preferred.
　紫外線吸収剤は、発泡剤の含浸時に、含浸系に存在している。紫外線吸収剤は、発泡剤の含浸と共に、樹脂粒子と接触することで、樹脂粒子の表面層にコーティングされると共に、内部に浸透するものと発明者等は考えている。その使用量は、樹脂粒子１００重量部に対して、０．０１～０．５重量部であることが好ましい。０．０１重量部より少ない場合、得られる発泡性樹脂粒子に含まれる紫外線吸収剤の量が少なくなり、その結果、所望の紫外線遮蔽性が得られないことがある。０．５重量部より多い場合、通常使用される発泡成形体の厚さから考えると、それ以上添加しても効果は同等程度のものしか得られないことや、生産時の取り扱いが不便であることや、耐衝撃性の低下が危惧される。より好ましい使用量は、０．０２～０．４重量部である。 The UV absorber is present in the impregnation system when impregnated with the foaming agent. The inventors consider that the ultraviolet absorber is coated on the surface layer of the resin particles by being in contact with the resin particles while being impregnated with the foaming agent, and penetrates into the inside. The amount used is preferably 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the resin particles. When the amount is less than 0.01 parts by weight, the amount of the ultraviolet absorber contained in the obtained expandable resin particles decreases, and as a result, the desired ultraviolet shielding property may not be obtained. When the amount is more than 0.5 parts by weight, considering the thickness of a normally used foamed molded product, even if it is added more than that, only the same effect can be obtained, and handling during production is inconvenient. In addition, there is a concern about the decrease in impact resistance. A more preferred use amount is 0.02 to 0.4 parts by weight.
　　（３）発泡剤
　発泡剤としては、公知の種々の揮発性発泡剤が使用できる。具体的には、ヘキサン、ノルマルペンタン、イソペンタン、ネオペンタン、工業用ペンタン、石油エーテル、ノルマルブタン、イソブタン、プロパン、シクロヘキサン、シクロペンタン等の単独又は混合物が挙げられる。特に、ブタン、ペンタンを用いることが好ましい。
　更に、発泡助剤を用いてもよい。発泡助剤としては、例えば、シクロヘキサン、ｄ－リモネン等の溶剤、ジイソブチルアジペート、グリセリン、ジアセチル化モノラウレート、やし油等の可塑剤（高沸点溶剤）が挙げられる。なお、発泡助剤の添加量としては、樹脂粒子１００重量部に対して０．５～１０重量部が好ましい。 (3) Foaming agent Various known volatile foaming agents can be used as the foaming agent. Specific examples include hexane, normal pentane, isopentane, neopentane, industrial pentane, petroleum ether, normal butane, isobutane, propane, cyclohexane, and cyclopentane. In particular, it is preferable to use butane or pentane.
Further, a foaming aid may be used. Examples of foaming aids include solvents such as cyclohexane and d-limonene, and plasticizers (high-boiling solvents) such as diisobutyl adipate, glycerin, diacetylated monolaurate, and coconut oil. The addition amount of the foaming aid is preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the resin particles.
　発泡剤の含浸は、例えば、加圧下又は常圧下、３０～１４０℃の温度で、それ自体公知の方法により０．５～６時間行うことができる。例えば、Ｖ型、Ｃ型あるいはＤＣ型等の回転混合機であって、密閉耐圧の容器中で樹脂粒子を流動させ、発泡剤を導入して含浸させる方法、攪拌機付密閉耐圧容器中で樹脂粒子を発泡剤に浸漬して含浸させる方法、重合による樹脂粒子製造後の密閉系の容器中に、発泡剤を圧入して含浸させる方法等が挙げられる。 The impregnation with the foaming agent can be performed, for example, under pressure or normal pressure at a temperature of 30 to 140 ° C. by a method known per se for 0.5 to 6 hours. For example, a rotary mixer such as a V-type, C-type, or DC-type, in which resin particles are flowed in a sealed pressure-resistant container and a foaming agent is introduced and impregnated; And a method of impregnating and impregnating a foaming agent into a closed container after production of resin particles by polymerization.
　発泡性樹脂粒子中の発泡剤の含有量は、樹脂粒子１００重量部に対して、７．５～１１重量部であることが好ましい。発泡剤の含有量が７．５重量部未満であると、発泡性樹脂粒子の発泡性が低下することがある。発泡性が低下すると、嵩倍数の高い低嵩密度の予備発泡粒子が得られ難くなると共に、この予備発泡粒子を型内成形して得られる発泡成形体は融着率が低下し、耐割れ性が低下することがある。一方、１１重量部を超えると、嵩倍数６５倍以上の低嵩密度の予備発泡粒子を得ることができる。しかし、予備発泡粒子中の気泡サイズが過大となり易く、成形性の低下や、得られる発泡成形体の圧縮、曲げ等の強度特性の低下が発生することがある。より好ましい発泡剤の含有量は、８～１０．５重量部の範囲である。 The content of the foaming agent in the expandable resin particles is preferably 7.5 to 11 parts by weight with respect to 100 parts by weight of the resin particles. If the content of the foaming agent is less than 7.5 parts by weight, the foamability of the foamable resin particles may be lowered. When foamability is reduced, it becomes difficult to obtain low-bulk-density pre-expanded particles having a high bulk ratio, and the foam-molded product obtained by molding the pre-expanded particles in a mold has a lower fusion rate and is resistant to cracking. May decrease. On the other hand, when the amount exceeds 11 parts by weight, pre-expanded particles having a low bulk density of 65 times or more can be obtained. However, the bubble size in the pre-expanded particles tends to be excessive, and the moldability and the strength characteristics such as compression and bending of the obtained foamed molded product may be reduced. A more preferable foaming agent content is in the range of 8 to 10.5 parts by weight.
　　（４）発泡性樹脂粒子の平均粒子径
　発泡性樹脂粒子の平均粒子径は、８００～２４００μｍであることが好ましい。８００μｍを下回る平均粒子径の発泡性樹脂粒子は、その粒子を得る際に収率が悪く、その結果コストアップすることがある。また、発泡剤の保持性が低下してビーズライフが短くなる傾向がある。２４００μｍを越えると、複雑な形状をした発泡成形体を成形する際、金型への充填性が悪くなる傾向がある。好ましい平均粒子径は、１２００～２０００μｍである。 (4) Average particle diameter of expandable resin particles The average particle diameter of the expandable resin particles is preferably 800 to 2400 μm. When the expandable resin particles having an average particle diameter of less than 800 μm are obtained, the yield is poor, and as a result, the cost may increase. In addition, the retention of the foaming agent tends to be reduced and the bead life tends to be shortened. If it exceeds 2400 μm, the filling property to the mold tends to be poor when molding a foamed molded product having a complicated shape. A preferable average particle diameter is 1200 to 2000 μm.
　（予備発泡粒子）
　次に、発泡性樹脂粒子を例えば嵩倍数５～６０倍に予備発泡させることで予備発泡粒子を得ることができる。具体的には、発泡剤が含浸された発泡性樹脂粒子を、必要に応じて、水蒸気等の加熱媒体を用いて加熱して所定の嵩密度に予備発泡させることで、予備発泡粒子を得ることができる。
　予備発泡粒子は、嵩倍数５～６０倍（嵩密度０．０１６～０．２ｇ／ｃｍ3）を有している。好ましい嵩倍数は１０～５５倍である。嵩倍数が６０倍より大きいと、予備発泡粒子の独立気泡率が低下して、予備発泡粒子を発泡させて得られる発泡成形体の強度が低下することがある。一方、５倍より小さいと、予備発泡粒子を発泡させて得られる発泡成形体の重量が増加することがある。 (Pre-expanded particles)
Next, the pre-expanded particles can be obtained by pre-expanding the expandable resin particles to a bulk multiple of 5 to 60 times, for example. Specifically, the foamed resin particles impregnated with the foaming agent are heated using a heating medium such as water vapor as necessary to pre-foam to a predetermined bulk density to obtain pre-foamed particles. Can do.
The pre-expanded particles have a bulk multiple of 5 to 60 times (bulk density 0.016 to 0.2 g / cm 3 ). The preferred bulk factor is 10 to 55 times. When the bulk factor is larger than 60 times, the closed cell ratio of the pre-expanded particles is lowered, and the strength of the foamed molded product obtained by foaming the pre-expanded particles may be lowered. On the other hand, if it is less than 5 times, the weight of the foamed molded product obtained by foaming the pre-foamed particles may increase.
　（発泡成形体）
　本発明の発泡成形体は、紫外線吸収剤を含む発泡性樹脂粒子から得られる。また、発泡成形体は、その表皮から５ｍｍの厚さにカットされた試料において、３％以下の３６５ｎｍの波長の光の透過率を有している。要するに、この発泡成形体は、表皮から５ｍｍの厚さの領域において高い紫外線の遮蔽性を有している。透過率は２％以下であることが好ましい。
　発泡成形体は、上記予備発泡粒子を液晶表示パネル、太陽電池セル、半導体ウェハ及び半導体装置から選択される電気製品の輸送及び／又は保管容器の形状に型内成形させることで得られる。具体的には、予備発泡粒子を成形機の型内に充填し、加熱して二次発泡させ、予備発泡粒子同士を融着一体化させることによって所望形状を有する発泡成形体を得ることができる。上記成形機としては、ポリスチレン系樹脂予備発泡粒子から発泡成形体を製造する際に用いられるＥＰＳ成形機等を用いることができる。
　上記電気製品は、紫外線の照射による劣化を防止することが強く求められている。本発明の発泡成形体は、紫外線吸収剤が表面だけでなく内部にも分散した発泡性樹脂粒子に由来する。そのため、透過光中の紫外線が、発泡成形体の表面で多く遮断されると共に、内部においても紫外線吸収剤を含んだセルを幾重にも散乱しながら通過することで、効率的に遮断できる。 (Foamed molded product)
The foamed molded product of the present invention is obtained from expandable resin particles containing an ultraviolet absorber. Further, the foamed molded article has a light transmittance of 365% or less of light of 3% or less in a sample cut to a thickness of 5 mm from the skin. In short, this foamed molded article has a high ultraviolet shielding property in a region having a thickness of 5 mm from the skin. The transmittance is preferably 2% or less.
The foamed molded body is obtained by molding the pre-expanded particles into a shape of a container for transporting and / or storing electrical products selected from liquid crystal display panels, solar cells, semiconductor wafers and semiconductor devices. Specifically, the pre-expanded particles are filled in a mold of a molding machine, heated and subjected to secondary foaming, and the pre-expanded particles are fused and integrated to obtain a foam-molded article having a desired shape. . As the molding machine, there can be used an EPS molding machine or the like used when producing a foam molded body from polystyrene resin pre-foamed particles.
The electrical products are strongly required to prevent deterioration due to ultraviolet irradiation. The foamed molded article of the present invention is derived from expandable resin particles in which an ultraviolet absorber is dispersed not only on the surface but also inside. For this reason, a large amount of ultraviolet light in the transmitted light is blocked on the surface of the foamed molded article, and also can be efficiently blocked by passing through the cell containing the ultraviolet absorber while being scattered inside and outside.
　例えば、発泡成形体の表皮部分を１ｍｍ程度にスライスしたものについての３５０ｎｍ、５００ｎｍ及び８００ｎｍの波長の光に対する透過率を測定した場合、本発明では、３５０ｎｍでの透過率／５００ｎｍでの透過率（比率Ａ）が１／２以下、及び／又は、３５０ｎｍでの透過率／８００ｎｍでの透過率（比率Ｂ）が１／３以下の関係を有する発泡成形体を得ることができる。比率Ａは、その値が低いほど、３５０ｎｍの波長の光が５００ｎｍの波長の光より透過し難いことを意味する。同様に、比率Ｂは、その値が低いほど、３５０ｎｍの波長の光が８００ｎｍの波長の光より透過し難いことを意味する。つまり、比率Ａ及びＢが低いほど、紫外線を選択的に遮蔽する効果が高いことを意味する。
　なお、比率Ａは０．４～０の範囲であることが好ましく、比率Ｂは０．３～０の範囲であることが好ましい。これら範囲内に透過率が存在することで、より紫外線を選択的に遮蔽する効果が高い発泡成形体を得ることができる。
　発泡成形体の形状は、特に限定されず、輸送及び／又は保管する製品の形状に応じて適宜設定できる。本発明の発泡成形体は、紫外線を効率的に遮断できるだけでなく、耐衝撃性にも優れているため、長距離の輸送や長期間の保管にも耐えることが可能である。 For example, when the transmittance for light having a wavelength of 350 nm, 500 nm, and 800 nm is measured for a slice of the skin portion of the foam molded article, the transmittance at 350 nm / the transmittance at 500 nm ( It is possible to obtain a foamed molded article having a relationship in which the ratio A) is 1/2 or less and / or the transmittance at 350 nm / the transmittance at 800 nm (ratio B) is 1/3 or less. The ratio A means that the lower the value, the harder it is to transmit light with a wavelength of 350 nm than light with a wavelength of 500 nm. Similarly, the ratio B means that the lower the value, the more difficult it is for light with a wavelength of 350 nm to transmit than light with a wavelength of 800 nm. That is, the lower the ratios A and B, the higher the effect of selectively blocking ultraviolet rays.
The ratio A is preferably in the range of 0.4 to 0, and the ratio B is preferably in the range of 0.3 to 0. By having the transmittance within these ranges, it is possible to obtain a foamed molded article having a higher effect of selectively blocking ultraviolet rays.
The shape of the foamed molded product is not particularly limited, and can be appropriately set according to the shape of the product to be transported and / or stored. The foamed molded article of the present invention can not only effectively block ultraviolet rays but also has excellent impact resistance, and can withstand long-distance transportation and long-term storage.
　以下実施例を挙げて更に説明するが、本発明はこれら実施例によって限定されるものではない。
　＜発泡性樹脂粒子の発泡剤含有量＞
　発泡性樹脂粒子を５～２０ｍｇ精秤し、測定試料とする。この測定試料を１８０～２００℃に保持された熱分解炉（島津製作所社製：ＰＹＲ－１Ａ）にセットし、測定試料を密閉後、１２０秒間に亘って加熱して発泡剤成分を放出させる。この放出された発泡剤成分をガスクロマトグラフ（島津製作所社製：ＧＣ－１４Ｂ、検出器：ＦＩＤ）を用いて下記条件にて発泡剤成分のチャートを得る。予め測定しておいた発泡剤成分の検量線に基づいて、得られたチャートから発泡性樹脂粒子中の発泡剤含有量（重量％）を算出する。
ガスクロマトグラフの測定条件
カラム：信和化工社製「Ｓｈｉｍａｌｉｔｅ　６０／８０　ＮＡＷ」（φ３ｍｍ×３ｍ）
カラム温度：７０℃
検出器温度：１１０℃
注入口温度：１１０℃
キャリアーガス：窒素
キャリアーガス流量：６０ｍｌ／ｍｉｎ The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.
<Foaming agent content of expandable resin particles>
Precisely weigh 5 to 20 mg of the expandable resin particles to obtain a measurement sample. This measurement sample is set in a pyrolysis furnace (manufactured by Shimadzu Corporation: PYR-1A) maintained at 180 to 200 ° C., and the measurement sample is sealed and heated for 120 seconds to release the blowing agent component. A chart of the blowing agent component is obtained under the following conditions using a gas chromatograph (manufactured by Shimadzu Corporation: GC-14B, detector: FID) for the released blowing agent component. Based on the calibration curve of the foaming agent component measured in advance, the foaming agent content (% by weight) in the foamable resin particles is calculated from the obtained chart.
Gas chromatograph measurement condition column: “Shimalite 60/80 NAW” (φ3 mm × 3 m), manufactured by Shinwa Kako Co., Ltd.
Column temperature: 70 ° C
Detector temperature: 110 ° C
Inlet temperature: 110 ° C
Carrier gas: Nitrogen carrier gas Flow rate: 60 ml / min
　＜予備発泡条件＞
　スチームで予熱した常圧予備発泡機（機内容積５０Ｌ）に発泡性樹脂粒子５００～２０００ｇ投入し、撹拌しながら約０．０２ＭＰａの設定でスチームを導入しつつ、空気も供給して、約２～３分間で所定の嵩密度（嵩倍数）まで発泡させる。 <Pre-foaming conditions>
500 to 2000 g of expandable resin particles are put into a normal pressure pre-foaming machine (internal volume 50 L) preheated with steam, and air is supplied while introducing steam at a setting of about 0.02 MPa while stirring, and about 2 to It is made to foam to a predetermined bulk density (bulk multiple) in 3 minutes.
　＜予備発泡粒子の嵩倍数＞
　約５ｇの予備発泡粒子の重量（ａ）を小数以下２位で秤量する。次に、最小メモリ単位が５ｃｍ3である５００ｃｍ3メスシリンダーに秤量した予備発泡粒子を入れる。これにメスシリンダーの口径よりやや小さい円形の樹脂板であって、その中心に巾約１．５ｃｍ、長さ約３０ｃｍの棒状の樹脂板が直立して固定された押圧具をあてて、予備発泡粒子の体積（ｂ）を読み取る。次いで、式（ｂ）／（ａ）により予備発泡粒子の嵩倍数を求める。 <Bulk multiple of pre-expanded particles>
The weight (a) of about 5 g of pre-expanded particles is weighed at the second decimal place. Next, weighed pre-expanded particles are placed in a 500 cm 3 graduated cylinder with a minimum memory unit of 5 cm 3 . Pre-foaming is applied to this with a circular resin plate that is slightly smaller than the diameter of the graduated cylinder, and a rod-shaped resin plate with a width of about 1.5 cm and a length of about 30 cm fixed upright at the center. Read the volume (b) of the particles. Next, the bulk multiple of the pre-expanded particles is determined by the formula (b) / (a).
　＜発泡成形体の倍数＞
　発泡成形体（成形後、４０℃で２０時間以上乾燥させたもの）から切り出した試験片（例７５×３００×３５ｍｍ）の重量（ａ）と体積（ｂ）をそれぞれ有効数字３桁以上になるように測定する。次いで、式（ｂ）／（ａ）により発泡成形体の倍数を求める。 <Multiple of foam molding>
The weight (a) and volume (b) of a test piece (example 75 × 300 × 35 mm) cut out from a foamed molded product (after being molded and dried at 40 ° C. for 20 hours or more) each have three or more significant figures. Measure as follows. Next, a multiple of the foamed molded product is obtained by the formula (b) / (a).
　＜発泡成形体の透過率＞
　（１）方法Ａ
　発泡成形体を表皮部分について５０×５０×５ｍｍ（±１ｍｍ以内）にカット（スライス）してサンプルを得る。図７に示すように、ＵＶライト１（ＳＥＮ　ＬＩＧＨＴＳ　ＣＯＲＰ社製ＨＬＲ１００Ｔ－２、ランプ：ＨＬ１００）が、分光放射計２（携帯型分光放射計（英弘精機社製ＭＳ－７２０））の受光部３の真上になるよう、かつ、ＵＶライト１先端から受光部３までが、９０±５ｍｍになるようにＵＶライト１と分光放射計３を設置する。図中、４は光源、５はランプカバーを意味する。
　まず、分光放射計１により、３６５ｎｍの波長の光についての原光放射度を測定する。その後、サンプルを受光部３に載せ、３６５ｎｍの波長の光についての透過放射度を測定する。得られた原光放射度とサンプルの透過放射度を以下式に代入することより、個々のサンプルの透過率を求める。本明細書での透過率は、１サンプルについて３回測定した値の平均値を意味する。
　透過率（％）＝サンプルの透過放射度（365nm）÷原光放射度（365nm）×100
　上記算出式にて得られた、透過率の平均値が３．０％以下であれば良好な紫外線遮断性があると判断する。 <Transmissivity of foam molded article>
(1) Method A
A sample is obtained by cutting (slicing) the foamed molded product into 50 × 50 × 5 mm (within ± 1 mm) of the skin portion. As shown in FIG. 7, the UV light 1 (HLR100T-2 manufactured by SEN LIGHTTS CORP, lamp: HL100) is the light receiving unit 3 of the spectroradiometer 2 (portable spectroradiometer (MS-720 manufactured by Eihiro Seiki Co., Ltd.)). The UV light 1 and the spectroradiometer 3 are installed so that the distance from the front end of the UV light 1 to the light receiving unit 3 is 90 ± 5 mm. In the figure, 4 indicates a light source and 5 indicates a lamp cover.
First, the original radioactivity for light having a wavelength of 365 nm is measured by the spectroradiometer 1. Thereafter, the sample is mounted on the light receiving unit 3 and the transmitted radiation for the light having a wavelength of 365 nm is measured. The transmittance of each sample is obtained by substituting the obtained original light radiance and the transmitted radiance of the sample into the following equation. The transmittance | permeability in this specification means the average value of the value measured 3 times about 1 sample.
Transmittance (%) = Sample transmitted irradiance (365nm) ÷ Original light irradiance (365nm) x 100
If the average value of the transmittance obtained by the above calculation formula is 3.0% or less, it is judged that there is a good ultraviolet blocking property.
　（２）方法Ｂ
　発泡成形体を表皮部分について、４０×４０×約１ｍｍ（厚さ）にカットスライスする。スライスした試料を、紫外可視分光光度計（島津製作所社製ＵＶ－２４５０ＰＣ）を用いて透過率を測定する。１つの試料に付き測定箇所を変更しながら、３点以上測定する。測定条件は、測定波長範囲８００～２００ｎｍ、スリット幅２．０ｎｍ、可視光紫外光源切換え波長３６０ｎｍとし、光源としてハロゲンランプ及び重水素ランプを使用する。
　得られた測定結果から、１測定点ごとに、以下の式１及び２で表されるように、５００ｎｍの透過率に対する３５０ｎｍの透過率（比率Ａ）及び８００ｎｍの透過率に対する３５０ｎｍの透過率（比率Ｂ）をそれぞれ算出する。次いで、３つ以上の測定点の比率Ａと比率Ｂの平均値を求める。 (2) Method B
The foam molded body is cut and sliced into 40 × 40 × about 1 mm (thickness) for the skin portion. The transmittance of the sliced sample is measured using an ultraviolet-visible spectrophotometer (UV-2450PC manufactured by Shimadzu Corporation). Measure three or more points while changing the measurement location on one sample. Measurement conditions are a measurement wavelength range of 800 to 200 nm, a slit width of 2.0 nm, a visible light ultraviolet light source switching wavelength of 360 nm, and a halogen lamp and a deuterium lamp are used as light sources.
From the obtained measurement results, as represented by the following formulas 1 and 2, for each measurement point, the transmittance of 350 nm with respect to the transmittance of 500 nm (ratio A) and the transmittance of 350 nm with respect to the transmittance of 800 nm ( Each ratio B) is calculated. Next, an average value of the ratios A and B of three or more measurement points is obtained.
　比率Ａが１／２以下、及び／又は、比率Ｂが１／３以下である場合、良好な紫外線遮断性があると判断する。なお、この判断は、５００ｎｍ及び８００ｎｍの透過率が１．０％以下の場合について行う。
(式1)（350nmの透過率）％/（500nmの透過率）％=1/2以下
(式2)（350nmの透過率）％/（800nmの透過率）％＝1/3以下 When the ratio A is 1/2 or less and / or the ratio B is 1/3 or less, it is determined that there is a good ultraviolet blocking property. This determination is made when the transmittance at 500 nm and 800 nm is 1.0% or less.
(Formula 1) (350 nm transmittance)% / (500 nm transmittance)% = 1/2 or less
(Formula 2) (350 nm transmittance)% / (800 nm transmittance)% = 1/3 or less
　＜発泡成形体の紫外線吸収剤検出量＞
　高速溶媒抽出装置（Ｄｉｏｎｅｘ製）を用いて試料より紫外線吸収剤をアセトニトリル液中に抽出する。得られた抽出液中の紫外線吸収剤の量を超高速液体クロマトグラフにて測定する。得られた値より、下式により発泡成形体中の紫外線吸収剤検出量を算出する。
　発泡成形体の紫外線吸収剤検出量（重量％）
＝抽出液中紫外線吸収剤濃度（μｇ／ｍＬ）×５０（ｍＬ）／０．２（ｇ）／１００００
　なお、抽出条件及び測定条件は次の通りである。
（ｉ）抽出条件
　測定装置：高速溶媒抽出装置　ＡＳＥ－３５０（Ｄｉｏｎｅｘ製）
　抽出温度：１００℃
　抽出溶媒：アセトニトリル／抽出セル＝１０ｍＬ
　抽出圧力：１０．５ＭＰａ
　昇温時間：５ｍｉｎ／静置時間：１５ｍｉｎ
　リンス量：２５％
　パージ時間：７０ｓｅｃ／３回（サイクル数）
　抽出用試料準備方法：精秤値が０．２ｇになるように、小カッターにて幅２ｍｍ（長さは約２．５ｃｍ、高さは約５～１５ｃｍ）の短冊状に裁断することで試料０．２ｇを得る。 <Detection amount of UV absorber in foamed molded product>
The ultraviolet absorber is extracted from the sample into an acetonitrile liquid using a high-speed solvent extraction device (manufactured by Dionex). The amount of the ultraviolet absorber in the obtained extract is measured with an ultrahigh performance liquid chromatograph. From the obtained value, the detected amount of the ultraviolet absorber in the foamed molded product is calculated by the following formula.
Detection amount of UV absorber in foamed molded product (wt%)
= UV absorber concentration in extract (μg / mL) × 50 (mL) /0.2 (g) / 10000
The extraction conditions and measurement conditions are as follows.
(I) Extraction conditions Measuring device: High-speed solvent extraction device ASE-350 (manufactured by Dionex)
Extraction temperature: 100 ° C
Extraction solvent: acetonitrile / extraction cell = 10 mL
Extraction pressure: 10.5 MPa
Temperature rising time: 5 min / Standing time: 15 min
Rinse amount: 25%
Purge time: 70 sec / 3 times (number of cycles)
Sample preparation method for extraction: The sample is cut into a strip with a width of 2 mm (length is about 2.5 cm, height is about 5 to 15 cm) with a small cutter so that the precision balance is 0.2 g. 0.2 g is obtained.
　（ｉｉ）測定条件
　測定装置：日立ハイテクノロジーズ社製超高速液体クロマトグラフＬａＣｈｒｏｍＵｌｔｒａ
　カラム　：ＬａＣｈｒｏｍＵｌｔｒａ　Ｃ１８　２μｍ（２．０ｍｍＩ．Ｄ．＊５０ｍｍＬ）
　測定条件：カラム温度（４０℃）、移動相（Ａ＝０．０５％ＴＦＡ　Ｂ＝アセトニトリル）、移動相流量（０．６ｍＬ／ｍｉｎ）、移動相条件（０→２ｍｉｎ＝Ｂｃｏｎｃ．５０％、２→４ｍｉｎ　Ｂｃｏｎｃ．５０％→１００％、４→１０ｍｉｎ＝Ｂｃｏｎｃ．１００％）、ポンプ温度（室温）、測定時間（１０ｍｉｎ）、検出（ＵＶ＝２２５ｎｍ）、注入量（２μＬ）
　測定用抽出液作製方法：アセトニトリルによる抽出液を５０ｍＬに定容する。定容された抽出液を、直径０．２０μｍの非水系クロマトディスクによりろ過することで、測定用抽出液とする。 (Ii) Measurement conditions Measuring device: Hitachi High-Technologies ultra-high performance liquid chromatograph LaChromUltra
Column: LaChromUltra C18 2 μm (2.0 mm ID * 50 mmL)
Measurement conditions: column temperature (40 ° C.), mobile phase (A = 0.05% TFA B = acetonitrile), mobile phase flow rate (0.6 mL / min), mobile phase conditions (0 → 2 min = Bconc. 50%, 2 → 4 min Bconc. 50% → 100%, 4 → 10 min = Bconc.100%), pump temperature (room temperature), measurement time (10 min), detection (UV = 225 nm), injection volume (2 μL)
Method for preparing extract for measurement: The extract with acetonitrile is made up to a volume of 50 mL. The fixed volume extract is filtered through a non-aqueous chromatographic disk having a diameter of 0.20 μm to obtain a measurement extract.
　＜発泡成形体の落球衝撃強度＞
　ＪＩＳ　Ｋ　７２１１に準拠し、所定の倍数の発泡成形体から切り出した２１５ｍｍ（長さ）×４０ｍｍ（幅）×２０ｍｍ（厚さ）の試験片を支点間の間隔１５０ｍｍの上に載置する。試験片に３２１ｇの剛球を落とすことにより、落球衝撃強度、すなわち５０％破壊高さを次の計算式により算出する。なお、試験片は、６面とも表皮はないものとする。 <Falling ball impact strength of foam molding>
In accordance with JIS K 7211, a test piece of 215 mm (length) × 40 mm (width) × 20 mm (thickness) cut out from a foamed product having a predetermined multiple is placed on a space of 150 mm between fulcrums. By dropping a 321 g hard ball on the test piece, the falling ball impact strength, that is, the 50% breaking height is calculated by the following formula. In addition, the test piece shall have no epidermis on all six sides.
　Ｈ５０＝Ｈｉ＋ｄ［Σ（ｉ・ｎｉ）／Ｎ±０．５］
　　Ｈ５０：５０％破壊高さ（ｃｍ）
　　Ｈｉ：高さ水準（ｉ）が０のときの試験高さ（ｃｍ）であり、試験片が破壊することが予測される高さ
　　ｄ：試験高さを上下させるときの高さ間隔（ｃｍ）
　　ｉ：Ｈｉのときを０とし、１つずつ増減する高さ水準
　　（ｉ＝…－３、－２、－１、０、１、２、３…）
　　ｎｉ：各水準において破壊した（又は破壊しなかった）試験片の数
　　Ｎ：破壊した（又は破壊しなかった）試験片の総数（Ｎ＝Σｎｉ）（いずれか多いほうのデータを使用する。なお、同数の場合はどちらを使用してもよい）
　　±０．５：破壊したデータを使用するときは負を、破壊しなかったデータを使用するときは正をとる。 H50 = Hi + d [Σ (i · ni) /N±0.5]
H50: 50% fracture height (cm)
Hi: Test height (cm) when the height level (i) is 0 and the height at which the test piece is expected to break d: Height interval (cm) when the test height is raised or lowered
i: Height level when Hi is 0, and a level that increases or decreases by 1 (i = ...- 3, -2, -1, 0, 1, 2, 3 ...)
ni: number of test pieces destroyed (or not destroyed) at each level N: total number of test pieces destroyed (or not destroyed) (N = Σni) (whichever is greater is used) Either can be used for the same number)
± 0.5: Negative when using destroyed data, positive when using non-destructed data.
　実施例１
　（樹脂粒子の製造）
　エチレン－酢酸ビニル共重合体樹脂粒子（日本ポリエチレン社製ＬＶ－２１１、メルトフローレート０．３ｇ／１０分、酢酸ビニル含量６．２重量％）１００重量部に、珪酸カルシウム０．３重量部とステアリン酸カルシウム０．１重量部とを加えて、押出機にて均一に混練した。混練物を水中カット方式により造粒ペレットとした（エチレン－酢酸ビニル共重合体樹脂粒子は１００粒あたり８０ｍｇに調整した）。
　内容積１００リットルの攪拌機付き耐圧容器に、上記ペレット４０重量部、純水１２０重量部、ピロリン酸マグネシウム０．４５重量部、ドデシルベンゼンスルホン酸ソーダ０．０２重量部を加えて混合物を得た。混合物を攪拌してペレットを純水中に懸濁させた。
　次いで、この懸濁液に、ラジカル重合開始剤としてジクミルパーオキサイド０．０３重量部を２０重量部のスチレンモノマーに溶解させた混合液を３０分かけて滴下した。滴下後３０分間保持した後、反応系の温度を１３５℃まで上昇させ、２時間保持した後、常温まで冷却した。 Example 1
(Manufacture of resin particles)
100 parts by weight of ethylene-vinyl acetate copolymer resin particles (LV-211, made by Nippon Polyethylene Co., Ltd., melt flow rate 0.3 g / 10 min, vinyl acetate content 6.2% by weight), 0.3 parts by weight of calcium silicate, 0.1 part by weight of calcium stearate was added and kneaded uniformly with an extruder. The kneaded product was granulated pellets by an underwater cutting method (the ethylene-vinyl acetate copolymer resin particles were adjusted to 80 mg per 100 particles).
A mixture was obtained by adding 40 parts by weight of the above pellets, 120 parts by weight of pure water, 0.45 parts by weight of magnesium pyrophosphate, and 0.02 parts by weight of sodium dodecylbenzenesulfonate to a pressure-resistant container with a stirrer having an internal volume of 100 liters. The mixture was stirred to suspend the pellet in pure water.
Next, a mixed solution obtained by dissolving 0.03 part by weight of dicumyl peroxide as a radical polymerization initiator in 20 parts by weight of styrene monomer was dropped into this suspension over 30 minutes. After maintaining for 30 minutes after dropping, the temperature of the reaction system was increased to 135 ° C., maintained for 2 hours, and then cooled to room temperature.
　次いで、この懸濁液に、ドデシルベンゼンスルホン酸ソーダ０．１６重量部を加えた後、反応系の温度を９０℃に昇温した。ベンゾイルパーオキサイド０．３重量部、ｔ－ブチルパーオキシベンゾエート０．０２重量部、ジクミルパーオキサイド０．８重量部を４０重量部のスチレンモノマーに溶解させて混合液を得た。この混合液を上記昇温後の反応系に４時間かけて滴下することで、スチレンモノマーをペレットに吸収させながら重合した。その後、反応系を９０℃で３時間保持した後、１３５℃に昇温させ、その温度で３時間保持することで重合を完結させた。上記重合を完結させた後、常温まで冷却し、複合樹脂粒子を得た。 Next, 0.16 part by weight of sodium dodecylbenzenesulfonate was added to this suspension, and then the temperature of the reaction system was raised to 90 ° C. A mixed solution was obtained by dissolving 0.3 part by weight of benzoyl peroxide, 0.02 part by weight of t-butylperoxybenzoate and 0.8 part by weight of dicumyl peroxide in 40 parts by weight of styrene monomer. The mixture was dropped into the reaction system after the temperature increase over 4 hours to polymerize the styrene monomer while absorbing the styrene monomer. Then, after hold | maintaining a reaction system at 90 degreeC for 3 hours, it heated up at 135 degreeC, and superposition | polymerization was completed by hold | maintaining at that temperature for 3 hours. After the polymerization was completed, the mixture was cooled to room temperature to obtain composite resin particles.
　（発泡剤及び紫外線吸収剤の含浸及び予備発泡）
　内容積５０リットルの耐圧で密閉可能なＶ型ブレンダーに、ポリエチレン改質ポリスチレン系樹脂粒子を１００重量部、紫外線吸収剤として２－（２Ｈ－ベンゾトリアゾール－２－イル）－ｐ－クレゾール（チバ・スペシャリティ・ケミカルズ社製ＴＩＮＵＶＩＮ　Ｐ）０．１０重量部、ジイソブチルアジペート０．５重量部、脂肪族第４級アンモニウム塩(第一工業製薬社製カチオーゲンＥＳ－ＯＷ）２．０重量部を加え、密閉し撹拌しながら、ブタン１４重量部を圧入した。そして、器内を６０℃で２時間保持した後、冷却して発泡性樹脂粒子を取り出した。得られた発泡性樹脂粒子中の発泡剤の含有量は９．０重量部であった。
　取り出した発泡性樹脂粒子は直ちに、バッチ式予備発泡機で嵩倍数３０倍に予備発泡して予備発泡粒子とし、その後温度２３℃の恒温室にて保管した。 (Impregnation with foaming agent and UV absorber and preliminary foaming)
A V-type blender with an internal volume of 50 liters that can be sealed with pressure resistance, 100 parts by weight of polyethylene-modified polystyrene resin particles, and 2- (2H-benzotriazol-2-yl) -p-cresol (Ciba Add 0.10 parts by weight of TINUVIN P, Specialty Chemicals, 0.5 parts by weight of diisobutyl adipate, and 2.0 parts by weight of an aliphatic quaternary ammonium salt (Cathogen ES-OW, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) While stirring, 14 parts by weight of butane was press-fitted. And after hold | maintaining the inside of a container at 60 degreeC for 2 hours, it cooled and took out the expandable resin particle. Content of the foaming agent in the obtained expandable resin particle was 9.0 weight part.
The taken-out expandable resin particles were immediately pre-expanded to a bulk multiple of 30 times with a batch type pre-expander to obtain pre-expanded particles, and then stored in a thermostatic chamber at a temperature of 23 ° C.
　（発泡成形）
　得られた予備発泡粒子の型内発泡成形を行った。３００ｍｍ（幅）×４００ｍｍ（長さ）×３０ｍｍ（厚さ）の金型内に予備発泡粒子を導入し、０．７ｋｇｆ／ｃｍ2の水蒸気を３０秒導入して加熱した。加熱後、発泡成形体の発泡圧が０．０５ｋｇｆ／ｃｍ2以下に低下するまで冷却を行い、倍数３０倍の発泡成形体を取り出した。
　取り出した発泡成形体を、３５℃の雰囲気下で６時間以上放置した。得られた発泡成形体の表皮部分の透過率を測定し、結果を図１に示す。また、方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量とを表１に示す。 (Foam molding)
The obtained pre-expanded particles were subjected to in-mold foam molding. Pre-expanded particles were introduced into a 300 mm (width) × 400 mm (length) × 30 mm (thickness) mold, and 0.7 kgf / cm 2 of water vapor was introduced for 30 seconds and heated. After the heating, cooling was performed until the foaming pressure of the foamed molded product decreased to 0.05 kgf / cm 2 or less, and a foamed molded product with a multiple of 30 times was taken out.
The removed foamed molded product was allowed to stand in an atmosphere of 35 ° C. for 6 hours or more. The transmittance of the skin portion of the obtained foamed molded product was measured, and the results are shown in FIG. Further, Table 1 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the detected amount of the ultraviolet absorber. Show.
　実施例２
　紫外線吸収剤として、オクタベンゾン（チバ・スペシャリティ・ケミカルズ社製ＣＨＩＭＡＳＳＯＲＢ　８１）を使用したこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．９重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定し、結果を図２に示す。また、方法Ａによる透過率と、測定結果算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量とを表１に示す。 Example 2
The same procedure as in Example 1 was performed except that octabenzone (CHIMASORB 81 manufactured by Ciba Specialty Chemicals) was used as the ultraviolet absorber. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured, and a result is shown in FIG. In addition, Table 1 shows the transmittance according to Method A, the transmittance at 350 nm, 500 nm, and 800 nm calculated by the measurement results (Method B), the ratios A and B, the falling ball impact value, and the UV absorber detection amount. .
　実施例３
　紫外線吸収剤として、２－（２Ｈ－ベンゾトリアゾール－２－イル）－４，６－ジ－ｔｅｒｔ－ペンチルフェノール（チバ・スペシャリティ・ケミカルズ社製ＴＩＮＵＶＩＮ　３２８）を使用したこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．９重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定し、結果を図３に示す。また、方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量とを表１に示す。 Example 3
Example 1 except that 2- (2H-benzotriazol-2-yl) -4,6-di-tert-pentylphenol (TINUVIN 328 manufactured by Ciba Specialty Chemicals) was used as the UV absorber. Went to. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured, and a result is shown in FIG. Further, Table 1 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the detected amount of the ultraviolet absorber. Show.
　実施例４
　紫外線吸収剤として、２－（２Ｈ－ベンゾトリアゾール－２－イル）－６－ドデシル－４－メチルフェノール（チバ・スペシャリティ・ケミカルズ社製ＴＩＮＵＶＩＮ　５７１）を使用したこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は９．０重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定し、結果を図４に示す。また、方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量とを表１に示す。 Example 4
As in Example 1, except that 2- (2H-benzotriazol-2-yl) -6-dodecyl-4-methylphenol (TINUVIN 571 manufactured by Ciba Specialty Chemicals) was used as the UV absorber. It was. Content of the foaming agent in the obtained expandable resin particle was 9.0 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured, and a result is shown in FIG. Further, Table 1 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the detected amount of the ultraviolet absorber. Show.
　実施例５
　発泡剤及び紫外線吸収剤の含浸を以下のように湿式で行うこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．５重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定した。方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量とを表１に示す。
　（湿式含浸）
　内容積５リットルの耐圧で密閉可能な撹拌機付き耐圧容器中の水１００重量部に、複合樹脂粒子１００重量部、ドデシルベンゼンスルホン酸ソーダ０．０４重量部、アルキルモノエタノールアミン（日油社製ナイミーンＬ－２０１）０．３重量部、紫外線吸収剤として、２－（２Ｈ－ベンゾトリアゾール－２－イル）－ｐ－クレゾール（ＴＩＮＵＶＩＮ　Ｐ）０．１０重量部を加え、撹拌し懸濁させた。
　その後、ブタン１４重量部を容器内に圧入した。その後、懸濁液の温度を７０℃まで昇温させ、３時間保持した。冷却後、得られた発泡性樹脂粒子を取出した。 Example 5
The same procedure as in Example 1 was performed except that the impregnation with the foaming agent and the ultraviolet absorber was performed in a wet manner as follows. Content of the foaming agent in the obtained expandable resin particle was 8.5 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured. Table 1 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm calculated from the measurement results (Method B), the ratios A and B, the falling ball impact value, and the UV absorber detection amount.
(Wet impregnation)
To 100 parts by weight of water in a pressure-resistant container with a stirrer capable of being sealed with an internal volume of 5 liters, 100 parts by weight of composite resin particles, 0.04 parts by weight of sodium dodecylbenzenesulfonate, alkyl monoethanolamine (manufactured by NOF Corporation) Nimin L-201) 0.3 parts by weight and, as a UV absorber, 0.10 parts by weight of 2- (2H-benzotriazol-2-yl) -p-cresol (TINUVIN P) were added and suspended by stirring. .
Thereafter, 14 parts by weight of butane was pressed into the container. Thereafter, the temperature of the suspension was raised to 70 ° C. and held for 3 hours. After cooling, the obtained expandable resin particles were taken out.
　比較例１
　紫外線吸収剤を添加しなかったこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．９重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定し、結果を図５に示す。また、方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値とを表１に示す。 Comparative Example 1
The same procedure as in Example 1 was performed except that no ultraviolet absorber was added. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured, and a result is shown in FIG. Further, Table 1 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm and 800 nm (Method B) calculated from the measurement results, the ratios A and B, and the falling ball impact value.
　比較例２
　実施例５のように湿式で発泡剤の含浸を行うこと以外は比較例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．６重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定した。方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値とを表１に示す。 Comparative Example 2
The same procedure as in Comparative Example 1 was performed except that the foaming agent was impregnated in a wet manner as in Example 5. Content of the foaming agent in the obtained expandable resin particle was 8.6 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured. Table 1 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm and 800 nm (Method B) calculated from the measurement results, the ratios A and B, and the falling ball impact value.
　実施例６
　紫外線吸収剤の添加量を０．０５重量部としたこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．８重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定した。方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量を表２に示す。 Example 6
The same procedure as in Example 1 was performed except that the addition amount of the ultraviolet absorber was 0.05 parts by weight. Content of the foaming agent in the obtained expandable resin particle was 8.8 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured. Table 2 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the UV absorber detection amount.
　実施例７
　紫外線吸収剤の添加量を０．０５重量部としたこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は９．２重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定し、結果を図６に示す。また、方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量を表２に示す。 Example 7
The same procedure as in Example 1 was performed except that the addition amount of the ultraviolet absorber was 0.05 parts by weight. The content of the foaming agent in the obtained expandable resin particles was 9.2 parts by weight. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured, and a result is shown in FIG. Further, Table 2 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the UV absorber detection amount. .
　実施例８
　紫外線吸収剤の添加量を０．０２重量部としたこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は９．０重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定した。方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量を表２に示す。 Example 8
The same operation as in Example 1 was performed except that the addition amount of the ultraviolet absorber was 0.02 part by weight. Content of the foaming agent in the obtained expandable resin particle was 9.0 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured. Table 2 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the UV absorber detection amount.
　実施例９
　紫外線吸収剤の添加量を０．００５重量部としたこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．９重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定した。方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量を表２に示す。 Example 9
The same operation as in Example 1 was performed except that the addition amount of the ultraviolet absorber was 0.005 part by weight. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured. Table 2 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the UV absorber detection amount.
　実施例１０
　紫外線吸収剤の添加量を０．０２重量部としたこと以外は実施例５と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．９重量部であった。また、得られた発泡成形体の表皮部分の透過率を測定した。方法Ａによる透過率と、測定結果から算出した３５０ｎｍ、５００ｎｍ及び８００ｎｍでの透過率（方法Ｂ）と、比率Ａ及びＢと、落球衝撃値と、紫外線吸収剤検出量を表２に示す。 Example 10
The same operation as in Example 5 was performed except that the addition amount of the ultraviolet absorber was 0.02 part by weight. Content of the foaming agent in the obtained expandable resin particle was 8.9 weight part. Moreover, the transmittance | permeability of the skin part of the obtained foaming molding was measured. Table 2 shows the transmittance by Method A, the transmittance at 350 nm, 500 nm, and 800 nm (Method B) calculated from the measurement results, the ratios A and B, the falling ball impact value, and the UV absorber detection amount.
　実施例１１
　予備発泡粒子の嵩倍数及び発泡成形体の倍数を１５倍としたこと以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．８重量部であった。方法Ａによる透過率と、落球衝撃値とを表３に示す。 Example 11
The same procedure as in Example 1 was performed except that the bulk magnification of the pre-expanded particles and the magnification of the foamed molded product were 15 times. Content of the foaming agent in the obtained expandable resin particle was 8.8 weight part. Table 3 shows the transmittance according to Method A and the falling ball impact value.
　実施例１２
　（樹脂粒子の製造）
　無架橋の直鎖状低密度ポリエチレン系樹脂として、メタロセン触媒を使用して合成したＬＬＤＰＥ（日本ポリエチレン社製の商品名「ＮＦ－４４４Ａ」、メルトフローレート（ＭＩ）＝２．０ｇ／１０分、密度：０．９１２ｇ／ｃｍ3）を用いた。この樹脂を押出機に投入して溶融混練した。混練物を水中カット方式により造粒ペレットとした（略球状、ポリエチレン系樹脂粒子は１００粒あたり約６０ｍｇに調整した）。
　内容積１００リットルの撹拌機付き耐圧容器に、ピロリン酸マグネシウム０．８重量部及びドデシルベンゼンスルホン酸ソーダ０．０２重量部を水１００重量部に分散させて分散用媒体を得た。分散用媒体に上記ポリエチレン系樹脂粒子１００重量部を分散させて懸濁液を得た。 Example 12
(Manufacture of resin particles)
As a non-crosslinked linear low density polyethylene resin, LLDPE synthesized using a metallocene catalyst (trade name “NF-444A” manufactured by Nippon Polyethylene Co., Ltd., melt flow rate (MI) = 2.0 g / 10 min. Density: 0.912 g / cm 3 ) was used. This resin was put into an extruder and melt-kneaded. The kneaded product was made into granulated pellets by an underwater cutting method (substantially spherical, polyethylene resin particles were adjusted to about 60 mg per 100 grains).
A dispersion medium was obtained by dispersing 0.8 parts by weight of magnesium pyrophosphate and 0.02 parts by weight of sodium dodecylbenzenesulfonate in 100 parts by weight of water in a pressure-resistant container equipped with a stirrer having an internal volume of 100 liters. 100 parts by weight of the polyethylene resin particles were dispersed in a dispersion medium to obtain a suspension.
　次に、重合開始剤としてジクミルパーオキサイド０．２重量部を予めスチレンモノマー１００重量部に溶解して第１のスチレンモノマー溶液を得た。上記懸濁液の温度を６０℃に調節し、第１のスチレンモノマー溶液を３０分かけて定量で懸濁液に添加した。この後、６０℃で１時間攪拌してポリエチレン系樹脂粒子中にスチレンモノマーを含浸させた。次に分散液の温度を１３０℃に昇温し、１３０℃を２時間保持してスチレンモノマーをポリエチレン系樹脂粒子中で重合させた。
　引き続いて、重合開始剤としてジクミルパーオキサイド０．３５重量部をスチレンモノマー３００重量部に溶解させて第２のスチレンモノマー溶液を得た。第２のスチレンモノマー溶液を、先の重合系に１時間あたり６０重量部の割合で５時間かけて連続的に滴下した。第２のスチレンモノマー溶液中のスチレンモノマーを、ポリエチレン系樹脂粒子中に含浸させながら重合させた。上記重合後、常温まで冷却し、複合樹脂粒子を得た。 Next, 0.2 parts by weight of dicumyl peroxide as a polymerization initiator was previously dissolved in 100 parts by weight of styrene monomer to obtain a first styrene monomer solution. The temperature of the suspension was adjusted to 60 ° C., and the first styrene monomer solution was quantitatively added to the suspension over 30 minutes. Then, it stirred at 60 degreeC for 1 hour, and impregnated the styrene monomer in the polyethylene-type resin particle. Next, the temperature of the dispersion was raised to 130 ° C., and the temperature was maintained at 130 ° C. for 2 hours to polymerize the styrene monomer in the polyethylene resin particles.
Subsequently, 0.35 parts by weight of dicumyl peroxide as a polymerization initiator was dissolved in 300 parts by weight of styrene monomer to obtain a second styrene monomer solution. The second styrene monomer solution was continuously added dropwise to the previous polymerization system at a rate of 60 parts by weight per hour for 5 hours. The styrene monomer in the second styrene monomer solution was polymerized while impregnating the polyethylene resin particles. After the polymerization, the mixture was cooled to room temperature to obtain composite resin particles.
　（発泡剤及び紫外線吸収剤の含浸及び予備発泡）
　ジイソブチルアジペートの量を０．９重量部とし、ブタンの量を１８重量部とし、脂肪族第４級アンモニウム塩を使用しないこと以外は実施例１と同様にして発泡性樹脂粒子を得た。得られた発泡性樹脂粒子中の発泡剤の含有量は９．１重量部であった。発泡性樹脂粒子を実施例１と同様にして予備発泡させることで嵩倍数５０倍の予備発泡粒子を得、その後温度２３℃の恒温室にて保管した。
　（発泡成形）
　実施例１と同様にして型内発泡成形を行い、倍数５０倍の発泡成形体を得た。方法Ａによる透過率と、落球衝撃値とを表３に示す。 (Impregnation with foaming agent and UV absorber and preliminary foaming)
Expandable resin particles were obtained in the same manner as in Example 1 except that the amount of diisobutyl adipate was 0.9 parts by weight, the amount of butane was 18 parts by weight, and no aliphatic quaternary ammonium salt was used. Content of the foaming agent in the obtained expandable resin particle was 9.1 weight part. The foamed resin particles were prefoamed in the same manner as in Example 1 to obtain prefoamed particles having a bulk multiple of 50 times, and then stored in a thermostatic chamber at a temperature of 23 ° C.
(Foam molding)
In-mold foam molding was carried out in the same manner as in Example 1 to obtain a foam molded article having a multiple of 50 times. Table 3 shows the transmittance according to Method A and the falling ball impact value.
　実施例１３
　紫外線吸収剤の添加量を０．０２重量部としたこと以外は実施例１２と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は９．１重量部であった。方法Ａによる透過率と、落球衝撃値とを表３に示す。 Example 13
The same operation as in Example 12 was performed except that the addition amount of the ultraviolet absorber was 0.02 part by weight. Content of the foaming agent in the obtained expandable resin particle was 9.1 weight part. Table 3 shows the transmittance according to Method A and the falling ball impact value.
　実施例１４
　（樹脂粒子の製造）
　内容量１００リットルの攪拌機付き重合容器に、水４００００重量部、第三リン酸カルシウム１００重量部及びドデシルベンゼンスルフォン酸カルシウム２．０重量部を供給して分散液を得た。次いで、分散液に、攪拌下で、スチレンモノマー４００００重量部、ベンゾイルパーオキサイド９６．０重量部及びｔ－ブチルパーオキシベンゾエート２８．０重量部を添加した。添加後で９０℃に昇温してスチレン系モノマーを重合させた。そして、この温度で６時間保持し、更に、１２５℃に昇温した。昇温してから２時間後に室温まで冷却することで、ポリスチレン系樹脂粒子（Ａ）を得た。
　ポリスチレン系樹脂粒子（Ａ）を篩分けすることで、種粒子として粒子径０．５～０．７１ｍｍのポリスチレン系樹脂粒子（Ｂ）を得た。 Example 14
(Manufacture of resin particles)
A dispersion liquid was obtained by supplying 40000 parts by weight of water, 100 parts by weight of tricalcium phosphate and 2.0 parts by weight of calcium dodecylbenzenesulfonate to a polymerization vessel equipped with a stirrer having an internal volume of 100 liters. Next, 40000 parts by weight of styrene monomer, 96.0 parts by weight of benzoyl peroxide and 28.0 parts by weight of t-butyl peroxybenzoate were added to the dispersion under stirring. After the addition, the temperature was raised to 90 ° C. to polymerize the styrene monomer. And it hold | maintained at this temperature for 6 hours, and also heated up at 125 degreeC. Polystyrene resin particles (A) were obtained by cooling to room temperature 2 hours after raising the temperature.
By sieving the polystyrene resin particles (A), polystyrene resin particles (B) having a particle diameter of 0.5 to 0.71 mm were obtained as seed particles.
　次に、内容量５リットルの攪拌機付き重合容器内に、水２０００重量部、ポリスチレン系樹脂粒子（Ｂ）５００重量部、ピロリン酸マグネシウム６．０重量部及びドデシルベンゼンスルフォン酸カルシウム０．３重量部を供給した。供給物を攪拌しながら７０℃に昇温した。
　次に、ベンゾイルパーオキサイド４．５重量部及びｔ－ブチルパーオキシベンゾエート１．１重量部をスチレンモノマー２００重量部に溶解させて溶液を得た。この溶液を上記５リットルの重合容器に供給した。供給してから３０分経過後に１００℃に昇温し、スチレンモノマー１３００重量部を２時間かけてポンプで一定量づつ上記５リットルの重合容器内に供給した。供給後、１２０℃に昇温し、昇温してから２時間経過後に室温まで冷却することでポリスチレン系樹脂粒子（Ｃ）を得た。 Next, in a polymerization vessel equipped with a stirrer having an internal volume of 5 liters, water 2000 parts by weight, polystyrene resin particles (B) 500 parts by weight, magnesium pyrophosphate 6.0 parts by weight and calcium dodecylbenzenesulfonate 0.3 parts by weight Supplied. The feed was heated to 70 ° C. with stirring.
Next, 4.5 parts by weight of benzoyl peroxide and 1.1 parts by weight of t-butylperoxybenzoate were dissolved in 200 parts by weight of styrene monomer to obtain a solution. This solution was supplied to the 5 liter polymerization vessel. After 30 minutes from the supply, the temperature was raised to 100 ° C., and 1300 parts by weight of styrene monomer was supplied into the 5 liter polymerization vessel by a fixed amount over 2 hours by a pump. After the supply, the temperature was raised to 120 ° C., and after 2 hours from the temperature raising, the resin was cooled to room temperature to obtain polystyrene resin particles (C).
　（発泡剤及び紫外線吸収剤の含浸）
　続いて、別の内容量５リットルの攪拌機付き重合容器に、水２２００重量部、ポリスチレン系樹脂粒子（Ｃ）１８００重量部、ピロリン酸マグネシウム６．０重量部及びドデシルベンゼンスルフォン酸カルシウム０．４重量部、２－（２Ｈ－ベンゾトリアゾール－２－イル）－ｐ－クレゾール（ＴＩＮＵＶＩＮ　Ｐ）１．８重量部（ポリスチレン系樹脂に対して０．１重量部）を供給して攪拌しながら７０℃に昇温した。次に、発泡助剤としてシクロヘキサン１８．０重量部及び可塑剤としてジイソブチルアジペート１２．６重量部を重合容器内に入れて密閉し１００℃に昇温した。
　次に、発泡剤としてｎ－ブタン１００重量部をポリスチレン系樹脂粒子（Ｃ）が入った重合容器内に圧入して３時間保持した。この後、３０℃以下まで冷却した上で重合容器内から発泡性樹脂粒子を取り出した。取り出した発泡性樹脂粒子は、乾燥させた上で１３℃の恒温室内に５日間放置した。 (Impregnation with foaming agent and UV absorber)
Subsequently, 2200 parts by weight of water, 1800 parts by weight of polystyrene resin particles (C), 6.0 parts by weight of magnesium pyrophosphate, and 0.4 parts by weight of calcium dodecylbenzenesulfonate were added to another polymerization vessel equipped with a stirrer having a capacity of 5 liters. 1 part, 2- (2H-benzotriazol-2-yl) -p-cresol (TINUVIN P) 1.8 parts by weight (0.1 parts by weight with respect to the polystyrene resin) and stirred at 70 ° C. The temperature rose. Next, 18.0 parts by weight of cyclohexane as a foaming aid and 12.6 parts by weight of diisobutyl adipate as a plasticizer were placed in a polymerization vessel, sealed and heated to 100 ° C.
Next, 100 parts by weight of n-butane as a foaming agent was pressed into a polymerization vessel containing polystyrene resin particles (C) and held for 3 hours. Then, after cooling to 30 degrees C or less, the expandable resin particle was taken out from the inside of a polymerization container. The taken-out expandable resin particles were dried and left in a thermostatic chamber at 13 ° C. for 5 days.
　（予備発泡及び発泡成形）
　上記発泡性樹脂粒子を使用すること以外は実施例１と同様に行った。得られた発泡性樹脂粒子中の発泡剤の含有量は８．５重量部であった。方法Ａによる透過率と、落球衝撃値とを表３に示す。 (Pre-foaming and foaming)
It carried out similarly to Example 1 except using the said expandable resin particle. Content of the foaming agent in the obtained expandable resin particle was 8.5 weight part. Table 3 shows the transmittance according to Method A and the falling ball impact value.
　表１～３中、評価結果中の○、△及び×は、次の基準に基づいている。即ち、発泡成形体は、紫外線遮蔽性と落球衝撃値の両者を兼ね備えていることが望ましい。よって、本明細書では、紫外線遮蔽性は、以下の条件（Ｉ）を、落球衝撃値は、以下の条件（ＩＩ）を、満たすことが望ましい、と規定する。
　条件（Ｉ）：方法Ａによる透過率が３．０％以下であること
　条件（ＩＩ）：落球衝撃値が３５ｃｍ以上であること
　○、△及び×は条件（Ｉ）と（ＩＩ）の観点で実施例及び比較例を以下のように評価している。
　○：条件（Ｉ）と（ＩＩ）の両方を満たす
　△：条件（Ｉ）と（ＩＩ）のどちらか一方のみを満たす
　×：条件（Ｉ）を満たさない
　表３中、ＥＶＡはエチレン－酢酸ビニル共重合体、ＰＳはポリスチレン、ｍＬＬＤＰＥはメタロセン触媒による無架橋の直鎖状低密度ポリエチレン系樹脂、をそれぞれ意味する。 In Tables 1 to 3, ◯, Δ, and × in the evaluation results are based on the following criteria. That is, it is desirable that the foamed molded product has both ultraviolet shielding properties and a falling ball impact value. Therefore, in this specification, it is defined that the ultraviolet shielding property preferably satisfies the following condition (I), and the falling ball impact value preferably satisfies the following condition (II).
Condition (I): Transmittance by method A is 3.0% or less Condition (II): Falling ball impact value is 35 cm or more ○, Δ and × are from the viewpoint of conditions (I) and (II) Examples and comparative examples are evaluated as follows.
○: Satisfies both conditions (I) and (II) Δ: Satisfies only one of conditions (I) and (II) ×: Does not satisfy condition (I) In Table 3, EVA is ethylene-vinyl acetate Copolymer, PS means polystyrene, and mLLDPE means non-crosslinked linear low density polyethylene resin by metallocene catalyst.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　実施例１～１４と比較例１～２とから、発泡性樹脂粒子が紫外線吸収剤を含むことで、それを原料として得られる発泡成形体の紫外線の遮蔽性が向上していることが分かる。紫外線の遮蔽性の向上は、図１～６からも明らかである。即ち、図では、紫外線の波長領域である、４００～３００ｎｍの波長の光に対して、実施例１～５は、比較例１よりも明らかに減少しているため、紫外線吸収剤を含むことで、紫外線の遮蔽性が向上していることが示されている。 From Examples 1 to 14 and Comparative Examples 1 and 2, it can be seen that when the expandable resin particles contain an ultraviolet absorber, the ultraviolet shielding property of the foamed molded article obtained from the foamed resin particles is improved. The improvement in ultraviolet shielding properties is also apparent from FIGS. That is, in the figure, Examples 1 to 5 are clearly less than Comparative Example 1 with respect to light having a wavelength of 400 to 300 nm, which is the wavelength region of ultraviolet rays. It has been shown that the shielding property of ultraviolet rays is improved.
　また、実施例１～４により、紫外線吸収剤を変更しても、発泡性樹脂粒子を原料として得られる発泡成形体の紫外線の遮蔽性が向上していることが分かる。加えて、従来、紫外線吸収剤は、比較的高温を必要とする樹脂との混練により樹脂粒子中に分散させていた。しかし、実施例１～５では、５０～７０℃という低温で行われる発泡剤の含浸工程にて紫外線吸収剤を樹脂内部に含浸させている。そのため、紫外線を遮断できる発泡成形体を簡易に得られることが分かる。
　更に、実施例１～１４により得られた発泡成形体は、電気製品の輸送・保管容器に十分適用可能な落球衝撃強度を有していることが分かる。 Further, it can be seen from Examples 1 to 4 that even when the ultraviolet absorbent is changed, the ultraviolet shielding property of the foamed molded article obtained from the foamable resin particles as a raw material is improved. In addition, conventionally, an ultraviolet absorber has been dispersed in resin particles by kneading with a resin that requires a relatively high temperature. However, in Examples 1 to 5, the ultraviolet absorbent is impregnated in the resin in the foaming agent impregnation step performed at a low temperature of 50 to 70 ° C. Therefore, it turns out that the foaming molding which can interrupt | block an ultraviolet-ray can be obtained easily.
Further, it can be seen that the foam molded articles obtained in Examples 1 to 14 have a falling ball impact strength that can be sufficiently applied to containers for transporting and storing electrical products.
　また、実施例１と５とから、紫外線吸収剤を乾式及び湿式のいずれで付与した場合でも、良好な紫外線の遮蔽性が得られることがわかる。
　更に、実施例１と６～９から、紫外線吸収剤の量を多くすることで、紫外線の遮蔽性が向上することが分かる。
　また、実施例１、１２及び１４から、樹脂種を変更しても、良好な紫外線の遮蔽性が得られることが分かる。なお、落球衝撃値はポリオレフィン成分が含まれているほうが良好であることが分かる。
　更に、実施例１と１１とから、発泡倍率を変化させても、良好な紫外線の遮蔽性が得られることが分かる。
　次に、方法Ａに使用したＵＶライトの波長毎の放射度を示すグラフを図８（ａ）に、実施例１と比較例１の発泡成形体の波長毎の放射度を示すグラフを図８（ｂ）に示す。図８（ｂ）中、点線は実施例１を、実線は比較例１を示す。図８（ｂ）から、実施例１の発泡成形体は、３６５ｎｍ付近の波長の光を有意に遮蔽できていることが分かる。 In addition, it can be seen from Examples 1 and 5 that good ultraviolet shielding properties can be obtained when the ultraviolet absorber is applied either dry or wet.
Furthermore, from Examples 1 and 6 to 9, it can be seen that the ultraviolet shielding property is improved by increasing the amount of the ultraviolet absorber.
In addition, it can be seen from Examples 1, 12, and 14 that good ultraviolet shielding properties can be obtained even if the resin type is changed. It is understood that the falling ball impact value is better when the polyolefin component is contained.
Furthermore, it can be seen from Examples 1 and 11 that good ultraviolet shielding properties can be obtained even when the expansion ratio is changed.
Next, FIG. 8A is a graph showing the irradiance for each wavelength of the UV light used in Method A, and FIG. 8 is a graph showing the irradiance for each wavelength of the foam molded articles of Example 1 and Comparative Example 1. Shown in (b). In FIG. 8B, the dotted line indicates Example 1 and the solid line indicates Comparative Example 1. FIG. 8B shows that the foamed molded product of Example 1 can significantly shield light having a wavelength of around 365 nm.
１　ＵＶライト、２　分光放射計、３　受光部、４　光源、５　ランプカバー 1 UV light, 2 spectroradiometer, 3 light receiving part, 4 light source, 5 lamp cover

Claims (6)

  1. 　発泡性樹脂粒子となりうる樹脂粒子と紫外線吸収剤を、発泡剤の含浸時に接触させることにより発泡性樹脂粒子を得、
    　次いで前記発泡性樹脂粒子を予備発泡させて予備発泡粒子を得、
    　更に、前記予備発泡粒子を、液晶表示パネル、太陽電池セル、半導体ウェハ及び半導体装置から選択される電気製品の輸送・保管容器に対応する形状に型内成形させることにより、紫外線遮蔽性を有する発泡成形体を得る工程からなる発泡成形体の製造方法。     Expandable resin particles are obtained by contacting resin particles that can become expandable resin particles and an ultraviolet absorber when impregnated with the foaming agent,
    Next, the foamable resin particles are prefoamed to obtain prefoamed particles,
    Further, the pre-expanded particles are molded in-mold into a shape corresponding to a transport / storage container for electrical products selected from liquid crystal display panels, solar cells, semiconductor wafers and semiconductor devices. A method for producing a foamed molded product comprising a step of obtaining a molded product.
  2. 　前記紫外線吸収剤が、ベンゾトリアゾール系又はベンゾフェノン系の紫外線吸収剤であり、前記樹脂粒子１００重量部に対して、０．０１～０．５重量部使用される請求項１に記載の発泡成形体の製造方法。 The foam molded article according to claim 1, wherein the ultraviolet absorber is a benzotriazole-based or benzophenone-based ultraviolet absorber and is used in an amount of 0.01 to 0.5 parts by weight with respect to 100 parts by weight of the resin particles. Manufacturing method.
  3. 　前記樹脂粒子が、ポリオレフィン系樹脂とポリスチレン系樹脂を含む樹脂粒子である請求項１に記載の発泡成形体の製造方法。 The method for producing a foam molded article according to claim 1, wherein the resin particles are resin particles containing a polyolefin resin and a polystyrene resin.
  4. 　前記樹脂粒子が、ポリオレフィン系樹脂１００重量部とポリスチレン系樹脂１２０～５６０重量部とを含む樹脂粒子である請求項１に記載の発泡成形体の製造方法。 2. The method for producing a foam molded article according to claim 1, wherein the resin particles are resin particles containing 100 parts by weight of a polyolefin resin and 120 to 560 parts by weight of a polystyrene resin.
  5. 　紫外線吸収剤を含む発泡性樹脂粒子から得られる発泡成形体であり、
    　前記発泡成形体は、その表皮から５ｍｍの厚さにカットされた試料において、３％以下の３６５ｎｍの波長の光の透過率を有する液晶表示パネル、太陽電池セル、半導体ウェハ及び半導体装置から選択される電気製品の輸送・保管容器用の発泡成形体。     It is a foam molded article obtained from expandable resin particles containing an ultraviolet absorber,
    The foamed molded product is selected from a liquid crystal display panel, a solar battery cell, a semiconductor wafer, and a semiconductor device having a transmittance of light having a wavelength of 365 nm of 3% or less in a sample cut to a thickness of 5 mm from the skin. Foam moldings for transport and storage containers for electrical products.
  6. 　前記樹脂が、ポリオレフィン系樹脂とポリスチレン系樹脂を含み、前記紫外線吸収剤が、ベンゾトリアゾール系又はベンゾフェノン系の紫外線吸収剤であり、前記樹脂１００重量部に対して、０．０１～０．５重量部使用される請求項５に記載の発泡成形体。 The resin includes a polyolefin-based resin and a polystyrene-based resin, and the ultraviolet absorber is a benzotriazole-based or benzophenone-based ultraviolet absorber, and is 0.01 to 0.5 weight with respect to 100 parts by weight of the resin. The foam-molded article according to claim 5, wherein a part thereof is used.
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