WO2022220223A1 - Adhesive composition and adhesive sheet - Google Patents

Adhesive composition and adhesive sheet Download PDF

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Publication number
WO2022220223A1
WO2022220223A1 PCT/JP2022/017514 JP2022017514W WO2022220223A1 WO 2022220223 A1 WO2022220223 A1 WO 2022220223A1 JP 2022017514 W JP2022017514 W JP 2022017514W WO 2022220223 A1 WO2022220223 A1 WO 2022220223A1
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WIPO (PCT)
Prior art keywords
monomer
polyol
sensitive adhesive
pressure
adhesive composition
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PCT/JP2022/017514
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French (fr)
Japanese (ja)
Inventor
豪 宮沢
光人 伊藤
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東洋インキＳｃホールディングス株式会社
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Publication of WO2022220223A1 publication Critical patent/WO2022220223A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
    • C09J175/04—Polyurethanes
    • C09J175/06—Polyurethanes from polyesters
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]

Definitions

  • An embodiment of the present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet using the same.
  • adhesives that make up adhesive labels on containers typically contain petroleum-derived raw materials.
  • the adhesive label may be peeled off from the container after use, or discarded in the ground while still attached to the container.
  • the adhesive since the decomposition rate of the adhesive constituting the adhesive label is extremely slow, the adhesive remains in the soil semi-permanently and may cause destruction of the ecosystem in the soil.
  • carbon dioxide is generated, which is one of the causes of global warming.
  • Patent Document 1 discloses a pressure-sensitive adhesive composition containing a biodegradable polyester polymer obtained by copolymerizing lactic acid and caprolactone, a tackifying resin, and an isocyanate curing agent.
  • Patent Document 2 it is obtained by copolymerizing lactic acid, dibasic acid and a glycol component, has a glass transition temperature of ⁇ 70 to ⁇ 20° C., a weight average molecular weight of 20,000 to 300,000, A pressure sensitive adhesive composition is disclosed comprising a polyester polymer having a hydroxyl value of 1 to 100 mg KOH/g.
  • the polyester polymer described above has an ester bond as the main binding site of the polymer chain, and has insufficient wettability to the base material, resulting in insufficient removability. Furthermore, the polyester polymer described above undergoes cohesive failure at the time of peeling due to hydrolysis of the ester group under moist and heat resistant conditions, and tends to stain the adherend. In addition, since the ester bond at the main binding site increases the crystallinity of lactic acid, there is also the problem of insufficient adhesion to adherends at low temperatures and low adhesive strength at low temperatures.
  • embodiments of the present invention provide a pressure-sensitive adhesive composition that uses a biodegradable raw material or a biomass-derived raw material, has excellent adhesive properties and low-temperature adhesion, and is less polluting.
  • Containing a urethane prepolymer (A) having a hydroxyl group The polyol (ax) is a monomer (ax'1) having a lactic acid unit and a monomer (ax'2) having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit (excluding lactic acid).
  • ) is a copolymer of a monomer mixture containing
  • the total content of the monomer (ax'1) and the monomer (ax'2) is 10 to The pressure-sensitive adhesive composition according to any one of [1] to [4] above, which is 99.8% by mass.
  • the monomer mixture constituting the polyol (ax) further includes a monomer (ax'3) capable of reacting with the monomer (ax'1) and the monomer (ax'2).
  • a monomer (ax'3) capable of reacting with the monomer (ax'1) and the monomer (ax'2).
  • the pressure-sensitive adhesive composition according to any one of [1] to [6] above, wherein the monomer (ax'3) comprises a polyester polyol having a number average molecular weight of 200 to 2,000.
  • biodegradable base material contains at least one selected from the group consisting of polysaccharides, polyvinyl alcohol resins, and biodegradable polyester resins.
  • the pressure-sensitive adhesive composition has a high degree of biomass and a high biodegradable raw material usage ratio, sufficiently satisfies the adhesive properties, and has low contamination to the adherend in the heat and humidity resistance test, It is also possible to provide a pressure-sensitive adhesive composition that is excellent in adhesion at low temperatures. Moreover, it becomes possible to provide a pressure-sensitive adhesive sheet using the pressure-sensitive adhesive composition.
  • the disclosure of the present application relates to the subject matter described in Japanese Patent Application No. 2021-068377 filed on April 14, 2021, and all disclosures thereof are incorporated herein by reference.
  • adheresive sheet means containing a substrate and an adhesive layer comprising a cured product of the adhesive composition of the present invention.
  • a monomer having a lactic acid unit (ax'1), a monomer having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit (ax'2), and other monomers (ax' 3) may be abbreviated as monomer (ax'1), monomer (ax'2), and monomer (ax'3), respectively.
  • the urethane prepolymer (A) having a hydroxyl group may be abbreviated as urethane prepolymer (A).
  • Mw is the polystyrene equivalent weight average molecular weight obtained by gel permeation chromatography (GPC) measurement.
  • Mn is the polystyrene-equivalent number-average molecular weight determined by GPC measurement.
  • Adhesive composition which is one embodiment of the present invention contains at least a urethane prepolymer (A) having a hydroxyl group.
  • the pressure-sensitive adhesive composition may further contain a curing agent, a tackifying resin, a plasticizer, or other optional components, if necessary.
  • the pressure-sensitive adhesive composition may further contain a solvent.
  • the pressure-sensitive adhesive composition which is one embodiment of the present invention, contains a specific urethane prepolymer (A) having urethane bonds in the molecule, thereby improving wettability to the substrate and excellent removability. is obtained.
  • A specific urethane prepolymer having urethane bonds in the molecule
  • the decomposition of the bonding sites in the polymer is suppressed, so the adherend is less likely to stain.
  • the crystallinity derived from lactic acid is suppressed in the polymer, not only is the adhesive property excellent, but also the adhesion to the adherend at low temperatures is improved, and these performances can be satisfied.
  • Urethane prepolymer (A) is a urethane prepolymer having a hydroxyl group, which is a reaction product of polyol (ax), polyfunctional polyol (ay) (excluding polyol (ax)), and polyisocyanate (az). is.
  • reactant means a reaction product of polyol (ax), polyfunctional polyol (ay), and polyisocyanate (az).
  • Polyol (ax) preferably has two hydroxyl groups in one molecule.
  • the polyfunctional polyol (ay) preferably has two or more hydroxyl groups in one molecule.
  • Polyisocyanate (az) is preferably bifunctional isocyanate (also referred to as diisocyanate) having two isocyanate groups in one molecule.
  • the isocyanate groups (isocyanato groups) of the polyisocyanate (az) are used at a molar ratio (NCO/OH) that is less than the total hydroxyl groups of the polyol (ax) and polyfunctional polyol (ay). Thereby, the obtained urethane prepolymer becomes a urethane prepolymer having a hydroxyl group.
  • the polyol (ax) is a monomer (ax'1) having a lactic acid unit and a monomer (ax'2) having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit (excluding lactic acid).
  • ) is a copolymer of a monomer mixture containing
  • the glass transition temperature of the urethane prepolymer (A) and lactic acid It becomes possible to appropriately control the derived crystallinity, respectively, and sufficient adhesion and adhesive strength at low temperatures can be obtained.
  • the number average molecular weight (Mn) of the polyol (ax) may be 1,000 to 45,000 or less.
  • Mn number average molecular weight
  • a urethane bond can be appropriately introduced.
  • the introduction of the urethane bond suppresses the decomposition of the bonding site in the polymer in the heat and humidity resistance test, and reduces the contamination of the adherend.
  • the cohesive strength is improved, and the adhesive strength is improved.
  • the wettability is improved and the removability is also improved.
  • the glass transition temperature (Tg) of the urethane prepolymer (A) is -60°C to -10°C.
  • the above Tg is more preferably -50°C to -12°C, still more preferably -45°C to -15°C.
  • the entanglement of the polymer chains provides an appropriate cohesive force and sufficient adhesive force.
  • the glass transition temperature is adjusted to ⁇ 60° C. or higher, a sufficient cohesive force can be obtained, and the adhesive force can be easily increased.
  • the glass transition temperature is adjusted to ⁇ 10° C. or lower, excessive increase in cohesive force at low temperatures can be suppressed, and excellent adhesion at low temperatures and excellent adhesive properties can be easily obtained.
  • the urethane prepolymer (A) comprises a polyol (ax) having a number average molecular weight of 1,000 to 45,000, a polyfunctional polyol (ay) (excluding the polyol (ax)), It is a urethane prepolymer having a hydroxyl group, which is a reactant with polyisocyanate (az), and has a glass transition temperature of -60°C to -10°C.
  • the urethane prepolymer (A) using a polyol (ax) having a number average molecular weight of 1,000 to 45,000 and having a glass transition temperature of ⁇ 60 to ⁇ 10° C. enables biomass Even when a large amount of the monomer (ax'1) and the monomer (ax'2), which are biomass or biodegradable raw materials, are used in order to increase the degree or the usage ratio of biodegradable raw materials, moisture resistance A pressure-sensitive adhesive composition with low contamination in a thermal test and excellent low-temperature adhesion and adhesive properties can be easily prepared.
  • the weight average molecular weight of the urethane prepolymer (A) is preferably 10,000 to 200,000, more preferably 30,000 to 180,000, still more preferably 40,000 to 150,000.
  • the weight average molecular weight of the urethane prepolymer (A) is adjusted within the above range, it is possible to impart a cohesive force due to the entanglement of the polymer chains, making it easy to increase the adhesive force.
  • the weight-average molecular weight is adjusted to 200,000 or less, it is preferable in that it is possible to suppress a decrease in holding power due to a decrease in cohesion.
  • the polyol (ax) is a monomer (ax'1) having a lactic acid unit, a monomer having a lactone unit, and a monomer having an aliphatic hydroxycarboxylic acid unit (excluding lactic acid ) and at least one of the monomers (ax′2).
  • the monomer mixture may further contain other monomers (ax'3) as necessary.
  • the total content of the monomer (ax'1) and the monomer (ax'2) is 10 to 99.8% by mass. preferably 50 to 99.8% by mass, even more preferably 60 to 99.8% by mass.
  • the glass transition temperature of the urethane prepolymer (A) can be easily adjusted to an appropriate range, and adhesive properties can be easily improved, which is preferable.
  • the content of at least one of monomer (ax'1) and monomer (ax'2) which are biomass raw materials or biodegradable raw materials It is preferable to increase In one embodiment, it is particularly preferred that both the monomer (ax'1) and the monomer (ax'2) are biomass feedstock or biodegradable feedstock monomers. In another embodiment, the content of the monomer (ax'3), which is a biomass raw material or a biodegradable raw material, can be increased in order to increase the biomass degree or the usage ratio of the biodegradable raw material.
  • a large amount of the monomer (ax'1) and the monomer (ax'2) is added in order to increase the biomass degree or the usage ratio of biodegradable raw materials. or even when the content of the monomer (ax'3) is increased, it not only has excellent adhesive properties, but also has low staining resistance in a moisture and heat resistance test, and has good adhesion at low temperatures.
  • An excellent adhesive composition can be provided.
  • the ratio (ax'1)/(ax'2) between the content of the monomer (ax'1) and the content of the monomer (ax'2) in the monomer mixture constituting the polyol (ax) is , preferably 10/90 to 90/10, more preferably 20/80 to 80/20, still more preferably 30/70 to 70/30.
  • the ratio (ax'1)/(ax'2) is even more preferably 40/60 to 60/40, most preferably 50/50.
  • the number average molecular weight (Mn) of polyol (ax) may be 1,000 or more, preferably 2,500 or more.
  • the Mn may be 45,000 or less, preferably 40,000 or less, more preferably 37,000 or less, and even more preferably 35,000.
  • the Mn may be from 1,000 to 45,000.
  • the above Mn may be preferably 1,000 to 35,000, more preferably 2,500 to 35,000.
  • the wettability and cohesive force due to the urethane bond can be easily controlled.
  • the Mn is adjusted to 1,000 or more, it is possible to prevent the number of urethane bonds in the polymer obtained by urethanization from becoming too large. That is, in a test under heating such as resistance to moist heat, the rearrangement of the urethane groups excessively improves the adhesion and suppresses the occurrence of cohesive failure, thereby improving the staining resistance to the adherend. easier.
  • the above Mn is adjusted to 45,000 or less, it is possible to suppress the deterioration of the moist heat resistance and the removability due to the insufficient number of urethane bonds.
  • the Mn of the polyol (ax) may exceed 10,000 and be 35,000 or less from the viewpoint of easily obtaining superior removability.
  • the above Mn may be more preferably 11,000 to 30,000, and even more preferably 11,000 to 25,000.
  • the Mn of polyol (ax) may be from 1,000 to 10,000, more preferably from 2,000 to 7,500.
  • the monomer (ax'1) having a lactic acid unit is not particularly limited as long as it has a lactic acid unit.
  • Examples include lactic acid forms (ax′1-1) such as L-lactic acid and D-lactic acid, lactide forms (ax′1-2) such as L-lactide, D-lactide, DL-lactide and meso-lactide. be done.
  • a urethane prepolymer (A) having desired properties can be obtained by copolymerizing a monomer (ax'1) having such a lactic acid unit and a monomer (ax'2) described later. can.
  • the lactic acid unit-containing monomer (ax'1) can be used singly or in combination of two or more.
  • lactic acid unit means a "--O--CH(CH3)--CO--" unit, which is a partial structure of lactic acid.
  • Lactide (ax'1-2) is more preferred between lactic acid (ax'1-1) and lactide (ax'1-2). From the viewpoint of reactivity, the lactide compound has excellent copolymerizability and can lower the degree of crystallinity, thereby easily improving removability.
  • Lactate (ax'1-1) and lactide (ax'1-2) are biomass-derived raw materials and biodegradable raw materials.
  • the lactide form (ax'1-2) is preferable from the viewpoint of reactivity control during polyol production and solubility in solvents.
  • the lactide form (ax'1-2) includes at least one selected from the group consisting of L-lactide, D-lactide, DL-lactide, and meso-lactide.
  • DL-lactide means an equimolar mixture of L-lactide and D-lactide.
  • the lactide form (ax'1-2) includes a combination of L-lactide and D-lactide, DL-lactide, or meso-lactide. Lactide is preferred. In particular, meso-lactide is preferable from the viewpoint of being amorphous and improving wettability and further improving removability.
  • the weight ratio of L-lactide/D-lactide is preferably 5/95 to 95/5, more preferably 15/85 to 85/15. is. Within this range, the degree of crystallinity of lactic acid in the urethane prepolymer (A) can be lowered, and the adhesion at low temperatures can be improved.
  • the monomer (ax'1) having a lactic acid unit preferably contains at least meso-lactide.
  • the monomer having a lactic acid unit (ax'1) may further contain other lactide forms such as L-lactide, D-lactide and DL-lactide in addition to meso-lactide.
  • the purification step removes lactide forms other than meso-lactide.
  • unpurified meso-lactide may be used. That is, in addition to meso-lactide, at least one of L-lactide, D-lactide and DL-lactide may be mixed.
  • the content of the monomer (ax'1) is preferably 5 to 92% by mass, more preferably 15 to 70% by mass, based on the total mass of the monomer mixture constituting the polyol (a). .
  • the glass transition temperature of the urethane prepolymer (A) can be adjusted appropriately, and excellent adhesion to the substrate at low temperatures and excellent adhesive strength can be easily obtained. preferable.
  • Monomer (ax'2) is a monomer having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit. In one embodiment, one monomer or two or more monomers may be used as the monomer (ax'2). In one embodiment, the monomer (ax'2) is a monomer (ax'2-1) having an aliphatic hydroxycarboxylic acid unit (excluding lactic acid) and a monomer having a lactone unit ( ax'2-2). In one embodiment, the monomer (ax'2) preferably contains at least a monomer (ax'2-2) having a lactone unit.
  • Examples of the monomer (ax'2-1) having an aliphatic hydroxycarboxylic acid unit include glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 6- hydroxycaproic acid and the like.
  • Examples of the monomer (ax'2-2) having a lactone unit include lactones having 3 to 12 carbon atoms. Examples include ⁇ -propiolactone, ⁇ -butyrolactone, ⁇ -valerolactone, ⁇ -caprolactone, enantholactone, caprylolactone, laurolactone and the like.
  • the monomer having a lactone unit (ax'2-2 ) is preferred.
  • the monomer (ax′2-2) having a lactone unit is excellent in copolymerizability from the viewpoint of reactivity, and can easily lower the crystallinity of the lactic acid component, so that the removability can be easily improved. can be improved.
  • the monomers (ax'2-2) having a lactone unit ⁇ -caprolactone or 6-hydroxycaproic acid is preferred from the viewpoint of biodegradability.
  • the lactone unit-containing monomer (ax'2-2) may be used alone or in combination of two or more.
  • the content of the monomer (ax'2) is preferably 5 to 92% by mass, more preferably 18 to 70% by mass, based on the total mass of the monomer mixture constituting the polyol (ax). .
  • the glass transition temperature of the urethane prepolymer (A) can be appropriately adjusted, and excellent adhesion at low temperatures and excellent adhesion can be easily obtained, which is preferable.
  • the monomer (ax'3) is a monomer other than the monomer (ax'1) and the monomer (ax'2), and the monomer (ax'1) and the monomer ( It is not particularly limited as long as it has reactivity with ax'2).
  • polyols such as aliphatic glycols, polyester polyols which are reaction products of aliphatic dibasic acids and glycols, polyether polyols, polybutadiene polyols, and castor oil polyols can be used as the monomer (ax'3). can be done.
  • the monomer mixture constituting the polyol (ax) further contains the other monomer (ax'3), it becomes easier to lower the crystallinity of the lactic acid component in the urethane prepolymer (A). .
  • the monomer (ax'3) is also preferably a biomass-derived raw material or a biodegradable raw material.
  • a polyester polyol can be preferably used as the monomer (ax'3).
  • the compatibility with the monomers (ax'1) and (ax'2) is excellent, and the copolymerizability is improved, so that the crystallinity of the lactic acid component can be reduced. It becomes easy to improve removability.
  • the aliphatic glycol that can be used as the monomer (ax'3) is not particularly limited.
  • 1,2-propylene glycol and 1,3-propanediol are preferred because they are obtained from biomass-derived raw materials and are biodegradable raw materials.
  • the above aliphatic glycols may be used alone or in combination of two or more.
  • a polyester polyol that can be used as the monomer (ax'3) is obtained, for example, by condensation reaction of an aliphatic dibasic acid and an aliphatic glycol.
  • the above polyester polyol preferably contains an aliphatic polyester polyol having terminal hydroxyl groups and having a COOH/OH molar ratio of less than 1.0.
  • Such aliphatic polyester polyols are preferable because, unlike aromatic polyester polyols, many enzymes capable of decomposing aliphatic polyester polyols exist in nature.
  • aliphatic dibasic acids examples include adipic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, dodecenyl succinic anhydride, fumaric acid, succinic acid, and dodecane.
  • Aliphatic and alicyclic dicarboxylic acids such as diacids, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic acid, maleic anhydride, itaconic acid, citraconic acid, and the like.
  • sebacic acid and succinic acid are preferred because they are obtained from biomass-derived raw materials and are biodegradable raw materials.
  • the above aliphatic dibasic acids may be used alone or in combination of two or more.
  • the aliphatic glycol is as explained above.
  • An aromatic dibasic acid can be used as a raw material for a polyester polyol as long as it does not reduce the properties of the adhesive desired in the present invention, the degree of biomass of the adhesive, and the ratio of biodegradable raw materials in the adhesive. can be done.
  • the aromatic dibasic acid that can be used is not particularly limited.
  • the polyester polyol In the polyester polyol, the smaller the number of carbon atoms in the alkylene chain of the aliphatic dibasic acid used during production, the more hard segment phases there are in the polymer. As a result, there is a tendency that it is possible to effectively prevent the infiltration of moisture and easily improve the resistance to moist heat. From the same point of view, the number of carbon atoms in the alkylene chain of the aliphatic glycol is also preferably small. From this point of view, in one embodiment, the polyester polyol comprises, for example, an aliphatic dibasic acid having an alkylene chain with 2 to 12 carbon atoms and an alkylene chain having a linear or branched structure with 2 to 10 carbon atoms. may be a polymer with an aliphatic glycol having
  • the aliphatic dibasic acid for example, selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid is preferred.
  • sebacic acid and succinic acid are more preferred because they are obtained from biomass-derived raw materials and are biodegradable raw materials, and succinic acid is even more preferred.
  • aliphatic glycols include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, and 1,3-butane.
  • 1,2-propylene glycol and 1,3-propanediol are more preferred, and 1,3-propanediol is even more preferred.
  • a commercially available product can also be used as the polyester polyol.
  • examples include Kuraray Polyol P-1010 and P-2010 manufactured by Kuraray Co., Ltd. These are copolymers of adipic acid and 3-methyl-1,5-pentanediol.
  • the polyether polyol that can be used as the monomer (ax'3) is, for example, a reaction in which an active hydrogen-containing compound having two active hydrogens in one molecule is used as an initiator and one or more oxirane compounds are subjected to addition polymerization. It can be a thing.
  • the oxirane compounds include alkylene oxides (AO) such as ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO); tetrahydrofuran (THF) and the like.
  • AO alkylene oxides
  • EO ethylene oxide
  • PO propylene oxide
  • BO butylene oxide
  • THF tetrahydrofuran
  • a commercially available product can also be used as the polyether polyol.
  • "Sannics PP-600" polyoxypropylene glycol) manufactured by Sanyo Kasei Co., Ltd. can be used.
  • Polybutadiene-modified polyols that can be used as the monomer (ax'3) have, for example, two or more hydroxyl group ends, 1,2-vinyl sites, 1,4-cis sites, 1,4-trans sites, or has a hydrogenated structure and may be linear or branched polybutadiene.
  • the castor oil polyol that can be used as the monomer (ax'3) may be, for example, a polyol derived from castor oil or a polyol obtained by modifying castor oil.
  • polyols derived from castor oil include those obtained by substituting part of ricinoleic acid in glycerin esters with oleic acid, those obtained by esterifying ricinoleic acid obtained by saponifying castor oil with short-molecular-weight polyols, They may be fatty acid ester polyols derived from castor oil, such as mixtures of these with castor oil.
  • polyols obtained by modifying castor oil include vegetable oil-modified polyols and modified polyols having an aromatic skeleton (eg, bisphenol A, etc.).
  • vegetable oil-modified polyol part of the ricinoleic acid of the glycerin ester is replaced with fatty acids obtained from other plants, such as higher fatty acids such as linoleic acid, linolenic acid, and oleic acid obtained from soybean oil, rapeseed oil, and olive oil. It is obtained by
  • castor oil-derived polyols examples include "URIC HF-1300, Y-403, HF-2009” manufactured by Ito Oil Co., Ltd., and the like.
  • the number average molecular weight (Mn) of the monomer (ax'3) is preferably 50-3,000, more preferably 500-2,000. In one embodiment, the Mn of the polyester polyol used as the monomer (ax'3) is preferably 150 to 3,000, more preferably 200 to 2,000, and 200 to 800. is more preferred.
  • the monomer (ax'3) having Mn within the above range is used, so the crystallinity of the component derived from the monomer (ax'3) is low, so the lactic acid component in the urethane prepolymer (A) crystallinity tends to be easily reduced. As a result, removability and resistance to moist heat can be easily improved.
  • the monomer mixture constituting the polyol (ax) is a compound having an active hydrogen such as a hydroxyl group only at one end, and an acidic compound such as a sulfonate. It preferably does not contain compounds in which the groups form salts. Therefore, in one embodiment, the monomer mixture that constitutes the polyol (ax) consists only of the monomer (ax'1), the monomer (ax'2), and the monomer (ax'3) is preferred.
  • a method for producing the polyol (ax) is not particularly limited.
  • Polyol (ax) can be produced by known polymerization methods such as bulk polymerization and solution polymerization.
  • the procedure of the manufacturing method includes, for example, the following.
  • (Procedure 1) A method of using a lactic acid body as a monomer (ax'1) and an aliphatic hydroxycarboxylic acid body as a monomer (ax'2) as raw materials and subjecting them to direct dehydration polycondensation (e.g., USP 5,310,865).
  • (Procedure 2) A ring-opening polymerization method in which a lactide body is used as a monomer (ax'1) and a lactone body is used as a monomer (ax'2), and these are melt-polymerized (e.g., US Pat. No. 2,758, 987). In this (Procedure 2), all the lactide and lactone bodies are ring-opened to obtain a polyol containing lactic acid units and aliphatic hydroxycarboxylic acid units.
  • (Procedure 3) A method of producing a polymer by carrying out a dehydration polycondensation reaction using a lactic acid compound and an aliphatic hydroxycarboxylic acid compound in the presence of a catalyst, wherein at least a part of the steps includes solid phase polymerization. How to do it. Further, in the above (Procedure 1) to (Procedure 3), the polyol (ax) may be obtained by further copolymerizing other monomers such as aliphatic glycol and aliphatic dibasic acid.
  • the polyol (ax) obtained by copolymerizing the lactic acid monomer (ax′1-1) and the aliphatic hydroxycarboxylic acid compound (ax′1-1) may not have sufficient copolymerizability of the lactic acid monomer (ax'1-1) and the aliphatic hydroxycarboxylic acid monomer (ax'1-1). Therefore, the desired glass transition temperature and lactic acid-derived crystallinity cannot be achieved in the resulting polyol (ax), and it may be difficult to obtain desired properties in the urethane prepolymer (A).
  • a polyol (ax The above (procedure 2) is preferable to the method for producing ).
  • Monomers containing a lactide monomer (ax′1-2) and a lactone monomer (ax′2-2) to produce a polyol (ax) as described above (Procedure 2) It is preferable to use a mixture of polymers because the reactivity can be easily controlled, the copolymerizability is excellent, and the molecular weight can be easily increased.
  • a catalyst, a solvent, etc. can be used for the production of the polyol (ax), if necessary.
  • the catalyst may be the same catalyst as exemplified in the production of the urethane prepolymer (A) having hydroxyl groups, which will be described later.
  • the content of the monomer (ax'3) is 0.2% by mass or more and 90% by mass or less based on the total mass of the monomer mixture constituting the polyol (ax). good.
  • the content of the monomer (ax'3) is preferably 3-90% by mass, more preferably 10-70% by mass.
  • a polyester polyol having a number average molecular weight of 1,000 to 3,000 can be suitably used as the monomer (ax'3).
  • the content of the monomer (ax'3) constitutes the polyol (ax) It is preferably 0.2 to 10% by mass based on the total mass of the monomer mixture.
  • the above content is more preferably 0.7 to 9.5% by mass, even more preferably 0.9 to 2.5% by mass.
  • the glass transition temperature of the urethane prepolymer (A) can be adjusted appropriately, and the adhesion at low temperatures is excellent, and the adhesion is excellent. It is preferable in that power can be obtained.
  • the polyfunctional polyol (ay) is a compound having two or more hydroxyl groups, preferably three or more hydroxyl groups.
  • the urethane prepolymer (A) can have a branched skeleton and can improve cohesive strength, thereby imparting initial curability.
  • the polyfunctional polyol (ay) excludes the polyol (ax).
  • the number average molecular weight of the polyfunctional polyol (ay) is preferably 100-5,000, more preferably 500-3,000, still more preferably 800-2,000. When the number average molecular weight is within this range, sufficient crosslink density can be obtained by reaction with the isocyanate curing agent (B), and the holding power is improved.
  • polyfunctional polyols aliphatic polyols
  • polyester polyols polyether polyols, polybutadiene polyols, castor oil polyols, and the like
  • aliphatic polyester polyols are preferred.
  • the polyester polyol is an aliphatic polyester polyol having three or more hydroxyl groups, which is a reaction product of a polycarboxylic acid and an aliphatic glycol, or a reaction product of an aliphatic dibasic acid and an aliphatic polyol. is more preferable.
  • Aliphatic polyester polyols are particularly preferred because there are many enzymes in nature that can decompose them.
  • polyvalent carboxylic acid examples include trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, ethylene glycol bis(anhydrotrimellitate), glycerol tris(anhydrotrimate), and the like. is mentioned.
  • the above-mentioned aliphatic glycol may be the same as the compounds described above in the description of the monomer (ax'3).
  • aliphatic polyols examples include glycerin, trimethylolpropane, and pentaerythritol.
  • the aliphatic dibasic acid may be the same as the compounds described above in the description of the monomer (ax'3).
  • a commercially available product can also be used as the polyfunctional polyol (ay).
  • Sannics PP-600 manufactured by Sanyo Chemical Industries, Ltd. can be mentioned.
  • This is polyoxypropylene glycol, a copolymer of glycerin, propylene oxide (PO) and ethylene oxide (EO).
  • NISSO-PBGI-3000 manufactured by Nippon Soda Co., Ltd. can be used.
  • Kuraray Polyol F-1010 manufactured by Kuraray Co., Ltd. can be used.
  • the content of the polyfunctional polyol (ay) is preferably 0.5-25% by mass, more preferably 5-15% by mass, based on the total mass of the urethane prepolymer (A).
  • the content is 25% by mass or less, it is possible to suppress the generation of gelled substances or aggregates during the production of the urethane prepolymer (A), which is preferable.
  • Polyisocyanate (az) A known compound can be used as the polyisocyanate (az). Examples include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates.
  • aromatic polyisocyanates include 1,3-phenylene diisocyanate, 4,4'-diphenyldiisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6 - tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanatotoluene, 1,3,5-triisocyanatobenzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4' ,4′′-triphenylmethane triisocyanate, ⁇ , ⁇ ′-diisocyanate-1,3-dimethylbenzene, ⁇ , ⁇ ′-diisocyanate-1,4-dimethylbenzene, ⁇ , ⁇ ′-diisocyanate-1,4-diethylbenzene , 1,4
  • aliphatic polyisocyanates examples include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodeca methylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and the like.
  • HDI hexamethylene diisocyanate
  • pentamethylene diisocyanate 1,2-propylene diisocyanate
  • 2,3-butylene diisocyanate 1,3-butylene diisocyanate
  • dodeca methylene diisocyanate 2,4,4-trimethylhexamethylene diisocyanate
  • alicyclic polyisocyanates examples include isophorone diisocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2 ,6-cyclohexanediisocyanate, 4,4′-methylenebis(cyclohexylisocyanate), and 1,4-bis(isocyanatomethyl)cyclohexane.
  • IPDI isophorone diisocyanate
  • 1,3-cyclopentane diisocyanate 1,3-cyclohexane diisocyanate
  • 1,4-cyclohexane diisocyanate methyl-2,4-cyclohexane diisocyanate
  • methyl-2 ,6-cyclohexanediisocyanate 4,4′-methylenebis(cyclohe
  • polyisocyanates examples include trimethylolpropane adducts, biurets, allophanates, and trimers of the above polyisocyanates (this trimer contains an isocyanurate ring).
  • polyisocyanate (az) 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and the like are preferable. When at least one of these is used, a suitable cohesive force can be imparted by urethane bonds, and sufficient adhesive properties can be easily obtained.
  • the molar ratio (NCO/OH value) of the total hydroxyl group of the polyol (ax) and the polyfunctional polyol (ay) to the isocyanate group (isocyanato group) of the polyisocyanate (az) is , may be 0.1 or more, preferably 0.2 to 0.9, more preferably 0.3 to 0.85, still more preferably 0.4 to 0.85. It is preferable to adjust the mixing ratio of the raw materials so that the molar ratio (NCO/OH value) is within the above range. When the NCO/OH value approaches 1, gelled products or aggregates may easily occur during production of the urethane prepolymer (A).
  • the NCO/OH value is adjusted to 0.9 or less, it is possible to effectively suppress gelation during the production of the urethane prepolymer (A).
  • the value of NCO/OH is adjusted to 0.1 or more, the obtained urethane prepolymer (A) has a high molecular weight, which is preferable in that sufficient adhesive properties can be obtained.
  • the content of the polyisocyanate (az) may be 0.3 or more, preferably 0.5 to 30% by mass, based on the total mass of the urethane prepolymer (A), in order to obtain high adhesive strength. 0.6 to 20% by mass is more preferable, and 1.0 to 20% by mass is even more preferable.
  • catalysts In the production of the polyol (ax) or the hydroxyl group-containing urethane prepolymer (A), one or more catalysts can be used as necessary.
  • a known compound can be used as the catalyst.
  • Usable catalysts include, for example, tertiary amine compounds and organometallic compounds.
  • tertiary amine compounds include triethylamine, triethylenediamine, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU).
  • organometallic compounds include tin-based compounds and non-tin-based compounds.
  • tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, dioctyltin dilaurate, tributyltin sulfide, and tributyltin.
  • DBTDL dibutyltin dilaurate
  • Tin oxide Tin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, tin 2-ethyloctylate, and tin 2-ethylhexanoate.
  • non-tin compounds include titanium compounds such as dibutyl titanium dichloride, tetrabutyl titanate, and butoxy titanium trichloride; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate; iron-based such as iron 2-ethylhexanoate and iron acetylacetonate; cobalt-based such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc-based such as zinc naphthenate and zinc 2-ethylhexanoate; zirconium naphthenate Zirconium-based such as.
  • the type and amount of catalyst to be added can be appropriately adjusted within a range in which the reaction proceeds well.
  • the amount of the catalyst used is preferably 0.0001 to 1.0 parts by mass with respect to the total 100 parts by mass of the constituent components of the polyol (ax) or urethane prepolymer (A).
  • the amount used is more preferably 0.001 to 0.5 parts by mass, more preferably 0.005 to 0.1 parts by mass, and 0.01 to 0.1 parts by mass. Even more preferred.
  • the catalyst When a catalyst is used in the production of polyol (ax) or urethane prepolymer (A), the catalyst may be deactivated. In particular, it is preferable to use an inactivated catalyst in the production of the urethane prepolymer (A) having hydroxyl groups.
  • a reaction terminator for example, acetylacetone, a phosphoric acid compound, or the like can be blended. The reaction terminator may be used alone or in combination of two or more.
  • solvents can be used in the production of the polyol (ax) and the urethane prepolymer (A).
  • Usable solvents include, for example, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as ethyl acetate, hydrocarbon solvents such as toluene and xylene, and ether solvents such as diphenyl ether.
  • ketone solvents such as acetone and methyl ethyl ketone
  • ester solvents such as ethyl acetate
  • hydrocarbon solvents such as toluene and xylene
  • ether solvents such as diphenyl ether.
  • the pressure-sensitive adhesive composition may contain the polyol (ax) and the solvent used during the production of the urethane prepolymer (A).
  • a method for producing the urethane prepolymer (A) is not particularly limited.
  • the urethane prepolymer (A) can be produced, for example, by known polymerization methods such as bulk polymerization and solution polymerization.
  • the procedure of the manufacturing method includes, for example, the following. (Procedure 1) one or more polyisocyanates (az), one or more polyols (ax), multifunctional polyols (ay), optionally one or more catalysts, and optionally one or more solvents and put them all together in a flask.
  • the above (procedure 2) is preferable.
  • the above (procedure 2) by suppressing the local decrease in reactivity of the polyol (ax), the polyfunctional polyol (ay) and the polyisocyanate (az) and suppressing excessive reaction of the high molecular weight component, The molecular weight dispersity can be broadened.
  • the reaction temperature is preferably less than 100°C, more preferably 85 to 95°C.
  • the reaction temperature is adjusted to less than 100° C., side reactions other than the urethane reaction can be suppressed, making it possible to easily obtain the desired polymer.
  • the reaction temperature is preferably 100° C. or higher, more preferably 110° C. or higher, when no catalyst is used.
  • the adhesive composition that is one embodiment of the present invention may further contain a curing agent.
  • a curing agent is preferred in terms of improving the curability of the polymer.
  • curing agents include isocyanate curing agents (B), epoxy curing agents, melamine curing agents, carbodiimide curing agents, oxazoline curing agents, and aziridine curing agents.
  • the pressure-sensitive adhesive composition preferably contains an isocyanate curing agent (B).
  • the use of the isocyanate curing agent (B) is preferable in that the initial curability can be further improved, and sufficient holding power can be easily obtained.
  • isocyanate curing agent (B) A known compound can be used as the isocyanate curing agent (B).
  • it may be a compound exemplified as polyisocyanate (az), which is a raw material for urethane prepolymer (A) having a hydroxyl group.
  • polyisocyanate (az) polyisocyanate
  • aromatic polyisocyanates, aliphatic polyisocyanates, araliphatic polyisocyanates, alicyclic polyisocyanates, and trimethylolpropane adducts/biurets/trimers thereof can be used.
  • the adhesive composition may further contain an isocyanate curing agent (B) as necessary.
  • the content of the isocyanate curing agent (B) is preferably 25 parts by mass or less, more preferably 1.0 to 15 parts by mass, and more preferably 1.5 to 15 parts by mass with respect to 100 parts by mass of the urethane prepolymer (A). More preferred. When the content of the isocyanate curing agent (B) is adjusted within the above range, better initial curability can be easily obtained.
  • the adhesive composition may further comprise a tackifying resin.
  • a tackifying resin is preferable because it can further improve the adhesive properties.
  • the tackifying resin for example, rosin-based resins, polyterpene resins, aliphatic hydrocarbon resins, aliphatic petroleum resins, aromatic petroleum resins, alkylphenol formaldehyde resins (oily phenolic resins) and the like can be used.
  • the tackifying resin is preferably a resin obtained from a biomass-derived raw material. From this point of view, resins such as rosin-based resins and polyterpene resins are preferable as the tackifying resin.
  • the content of the tackifying resin is preferably 2 to 50 parts by mass, more preferably 5 to 40 parts by mass, based on 100 parts by mass of the urethane prepolymer (A).
  • the content is adjusted to 2 parts by mass or more, the desired adhesive property can be easily obtained due to the effect of the addition of the tackifying resin.
  • the content is adjusted to 50 parts by mass or less, it is preferable in terms of obtaining good compatibility with the polymer component such as the urethane prepolymer (A). Therefore, it is possible to suppress the occurrence of the problem of cloudiness or whitening in the coating liquid appearance or coating film appearance.
  • the pressure-sensitive adhesive composition may further contain general additives in addition to the above components as long as the pressure-sensitive adhesive properties and biodegradability are not impaired.
  • Additives that can be used include, for example, ultraviolet absorbers, light stabilizers, leveling agents, antistatic agents, release modifiers, fillers, colorants, antioxidants, plasticizers, surfactants, and the like.
  • Adhesive Sheet Another embodiment of the present invention relates to an adhesive sheet.
  • the pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the above embodiment on at least one surface of a substrate. That is, the adhesive sheet has a substrate and an adhesive layer provided on at least one surface of the substrate, and the adhesive layer is composed of a cured product of the adhesive composition of the above embodiment.
  • a release sheet may be provided on the other side of the pressure-sensitive adhesive layer that is not in contact with the substrate in order to prevent adhesion of foreign matter.
  • the pressure-sensitive adhesive layer is usually protected by a release sheet until just before use.
  • Base materials include plastics, papers, metal foils, laminates made of one or more of these materials, and the like.
  • a simple adhesion treatment may be applied to the surface of the base material in contact with the pressure-sensitive adhesive layer in order to improve adhesion.
  • dry treatment such as corona discharge treatment
  • wet treatment such as application of an anchor coating agent can be applied.
  • the plastic material constituting the base material includes, for example, ester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyethylene (PE), polypropylene (PP) and cycloolefin polymer (COP); ); vinyl resins such as polyvinyl chloride; amide resins such as nylon 66; urethane resins (including foams).
  • ester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyethylene (PE), polypropylene (PP) and cycloolefin polymer (COP); ); vinyl resins such as polyvinyl chloride; amide resins such as nylon 66; urethane resins (including foams).
  • the thickness of the substrate may generally be 10-300 ⁇ m. When a polyurethane sheet (including foam) is used as the substrate, the thickness of the substrate (sheet) may generally be from 20 to 50,000 ⁇ m. Paper can also be used as a substrate. Examples include plain paper, coated paper, and art paper. Metal foil can also be used as the substrate. Examples of metal foil include aluminum foil and copper foil.
  • the release sheet may be a release sheet having a known configuration.
  • a release sheet obtained by applying a known release treatment such as a silicone release agent to the surface of a sheet-like material such as plastic or paper can be used.
  • the substrate is preferably a biodegradable substrate composed of biodegradable raw materials.
  • the biodegradable substrate may be, for example, one or a combination of two or more selected from the group consisting of paper substrates, cloth substrates, and biodegradable resin substrates.
  • paper substrates include substrates obtained by molding pulp, and substrates obtained by mixing pulp with manila hemp or the like to improve strength.
  • fabric substrates include substrates formed from fibers such as cotton, rayon, and acetate.
  • a biodegradable resin base material means a base material formed from a resin synthesized using biomass such as plants, animals, and microorganisms, or a petroleum-derived but biodegradable resin.
  • biodegradable resins that make up the biodegradable resin substrate include, for example, polysaccharides, polyvinyl alcohol resins, and biodegradable polyester resins.
  • a biodegradable resin substrate can be constructed by using one or more of these in combination.
  • polysaccharides include cellulose and cellulose acetate resins.
  • biodegradable polyester resins include polyhydroxyalkane resins such as polyhydroxyalkane resins, polyhydroxyalkanoate resins, polyethylene terephthalate succinate resins, polybutylene adipate terephthalate resins, polybutylene succinate resins, and polybutylene succinate adipate resins. ate resins, polycaprolactone resins, polylactic acid resins, and poly(hydroxybutyrate) resins.
  • the biodegradable base material preferably contains cellulose and cellulose acetate resin.
  • the biodegradable substrate preferably comprises polyvinyl alcohol resin.
  • the biodegradable substrate preferably comprises a biodegradable polyester resin.
  • the biodegradable base material may contain various additives such as fillers, plasticizers, and lubricants as needed, in addition to the biodegradable resin.
  • the adhesive composition of the above embodiment A combination with a pressure-sensitive adhesive layer formed from a material tends to facilitate obtaining excellent adhesive strength.
  • the number average molecular weight of the polyol (ax) used to prepare the urethane prepolymer (A) in the pressure-sensitive adhesive composition exceeds 10,000, the adhesion with the biodegradable substrate is It is possible to easily form a pressure-sensitive adhesive sheet having improved and excellent adhesive strength.
  • Biodegradable resins that can be used to form the biodegradable substrate are also commercially available. Examples include: ⁇ Cellulose Dissolving pulp ⁇ Cellulose acetate (CA) resin manufactured by Nippon Paper Chemicals Co., Ltd. L-series ⁇ Polyvinyl alcohol resin manufactured by Daicel Corporation Nichigo G-polymer ⁇ Polyhydroxyalkanoate resin manufactured by Mitsubishi Chemical Co., Ltd.
  • CA Cellulose Dissolving pulp
  • CA Cellulose acetate
  • L-series ⁇ Polyvinyl alcohol resin manufactured by Daicel Corporation Nichigo G-polymer ⁇ Polyhydroxyalkanoate resin manufactured by Mitsubishi Chemical Co., Ltd.
  • Polyethylene terephthalate succinate (PETS) resin Apexa4026/6926 manufactured by Dupon Polybutylene adipate terephthalate (PBAT) resin; manufactured by BASF, Ecoflex Polybutylene succinate (PBS) resin: PTT MCC Biochem, BioPBS FZ71, FZ91, and FZ78 Polybutylene succinate adipate (PBSA) resin: PTT MCC Biochem, BioPBS FD92
  • the biodegradable substrate is cellulose resin, cellulose acetate resin, polybutylene adipate terephthalate, polybutylene succinate, polylactic acid, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)
  • the substrate is preferably formed using at least one biodegradable resin selected from the group consisting of:
  • the biodegradable base material can also be formed using a resin treated with a decomposition treatment liquid containing a fatty acid metal salt that promotes biodegradability.
  • a resin treated with a decomposition treatment liquid containing a fatty acid metal salt that promotes biodegradability Commercially available products of such resins include, for example, P-LIFE GREEN 20 (PE resin, containing 20% SMC 2360 manufactured by P-LIFE Japan Inc. as a decomposition treatment liquid), and P-LIFE GREEN 20 ( PP resin, containing 20% of SMC2360 manufactured by the same company as a decomposition treatment liquid), and the like.
  • the method of molding the biodegradable resin into a film or sheet to form the base material is not particularly limited.
  • a method of extrusion molding in which a biodegradable resin film or sheet extruded from a T-die using an extruder is cooled and solidified with a cast roll, or a method of molding using an inflation molding machine can be applied.
  • the pressure-sensitive adhesive composition of the above embodiment is applied to the surface (one side or both sides) of a substrate to form a coating layer, and then the coating layer is dried and cured. , and a method of forming an adhesive layer. Heating and drying temperatures may generally range from 60 to 150°C. The thickness of the adhesive layer may generally be 0.1-200 ⁇ m.
  • the coating method may be a known method, such as roll coater method, comma coater method, die coater method, reverse coater method, silk screen method, and gravure coater method.
  • the pressure-sensitive adhesive composition of the above-described embodiment is applied to the surface of a release sheet to form a coating layer, and then the coating layer is dried and cured to form a pressure-sensitive adhesive layer. is formed, and finally a substrate is attached to the exposed surface of the pressure-sensitive adhesive layer.
  • a cast adhesive sheet having a configuration of release sheet/adhesive layer/release sheet can be obtained by laminating a release sheet to the adhesive layer instead of the substrate.
  • Mw, Mn, and Tg described below are values measured as follows. [Measurement of weight average molecular weight (Mw) and number average molecular weight (Mn)] Weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) method. Measurement conditions are as follows. Both Mw and Mn are polystyrene equivalent values.
  • Glass transition temperature (Tg) A robot DSC (differential scanning calorimeter, "RDC220” manufactured by Seiko Instruments Inc.) was connected to "SSC5200 Disk Station” (manufactured by Seiko Instruments Inc.) and used for measurement. Place about 10 mg of sample in an aluminum pan, weigh and set in a differential scanning calorimeter, hold the same type of aluminum pan without a sample as a reference at a temperature of 100 ° C. for 5 minutes, and then use liquid nitrogen to Quenched to -120°C. Thereafter, the temperature was raised at a rate of temperature increase of 10°C/min, and the glass transition temperature (Tg, unit: °C) was determined from the obtained DSC chart.
  • Tg glass transition temperature
  • PD 1,3-propanediol, Mn76, hydroxyl number 2, (100% biomass, 100% biodegradability)
  • PPG600 Sannics PP-600, polyoxypropylene glycol, Mn600, hydroxyl number 2, manufactured by Sanyo Chemical Industries, Ltd. (0% biomass, 0% biodegradability)
  • P-1010 Kuraray polyol P-1010, 3-methyl-1,5-pentanediol/adipic acid, polyester polyol, Mn 1,000, manufactured by Kuraray Co., Ltd.
  • P-2010 Kuraray polyol P-2010, 3-methyl-1,5-pentanediol/adipic acid, polyester polyol, Mn 2,000, manufactured by Kuraray Co., Ltd.
  • HF-1300 URIC HF-1300, castor oil polyol, Mn 1,400, number of hydroxyl groups 2, manufactured by Ito Oil (100% biomass, 0% biodegradability)
  • Polyols ax'3-1 to ax'3-3 as described later.
  • ⁇ Polyfunctional polyol (ay)> F-1010 Kuraray polyol F-1010, 3-methyl-1,5-pentanediol/adipic acid/trimethylolpropane polyester polyol, Mn 1,000, number of hydroxyl groups 3, manufactured by Kuraray Co., Ltd.
  • GL-600 Sannics PP-600, glycerin/PO/EO, polyoxypropylene glycol, Mn600, 3 hydroxyl groups, manufactured by Sanyo Chemical Industries (0% biomass, 0% biodegradability)
  • GI3000 NISSO-PBGI-3000, polybutadiene polyol, Mn 3,100, number of hydroxyl groups 2, manufactured by Nippon Soda Co., Ltd. (0% biomass, 0% biodegradability)
  • Placel 410 polycaprolactone polyol, Mn 1,010, number of hydroxyl groups 4, manufactured by Daicel (0% biomass, 100% biodegradability)
  • IPDI isophorone diisocyanate
  • HDI hexamethylene diisocyanate
  • XDI m-xylene diisocyanate
  • HDI-TMP Trimethylolpropane adduct of hexamethylene diisocyanate, Takenate D-160N, manufactured by Mitsui Chemicals
  • XDI-TMP Trimethylolpropane adduct of xylene diisocyanate, Takenate D-110N, manufactured by Mitsui Chemicals
  • TDI-Nu Tri Isocyanurate form of diisocyanate, Takenate D-204, manufactured by Mitsui Chemicals [carbodiimide curing agent]
  • V-09B carbodiimide, carbodilide V-09B, manufactured by Nisshinbo Chemical Co., Ltd.
  • ⁇ Tackifying resin> A-75: Superester A-75, rosin resin, manufactured by Arakawa Chemical Co., Ltd. (92% biomass, 0% biodegradability)
  • D-125 Pencel D-125, rosin resin, manufactured by Arakawa Chemical Co., Ltd. (85% biomass, 0% biodegradability)
  • the biomass content is the mass ratio (mass%) of the biomass-derived raw materials used during production, or the content based on ASTM D6866.
  • polyol (ax'3) (polyol (ax'3-1))
  • a polyester polyol (ax'3-1) having a number average molecular weight of 1,000 is obtained by polymerizing sebacic acid, which is a raw material derived from biomass and is also a biodegradable raw material, and 1,3-propanediol. rice field.
  • the polyol (ax'3-1) had a biomass degree of 100% and a biodegradability of 100%.
  • polyester polyol (ax'3-2) having a number average molecular weight of 800 was obtained by polymerizing succinic acid, which is a raw material derived from biomass and is also a biodegradable raw material, and 1,3-propanediol.
  • the polyol (ax'3-2) had a biomass degree of 100% and a biodegradability of 100%.
  • polyester polyol (ax′3-3) having a number average molecular weight of 200 was obtained by polymerizing succinic acid, which is a raw material derived from biomass and is also a biodegradable raw material, and 1,3-propanediol.
  • the polyol (ax'3-3) had a biomass degree of 100% and a biodegradability degree of 100%.
  • polyol (ax) (polyol (ax-1)) 100 parts of L-lactic acid, 35 parts of 6-hydroxycaproic acid, and 0.6 parts of tin powder were charged into a reactor equipped with a Dean-Stark trap. These were stirred at 150° C./50 mmHg for 3 hours to distill off the water, and then stirred at 150° C./30 mmHg for an additional 2 hours. Next, 210 parts of diphenyl ether was added to this reaction solution, and azeotropic dehydration was carried out at 150° C./35 mmHg. Distilled water and solvent were separated by a water separator, and only the solvent was returned to the reactor.
  • Polyol (ax-2, ax-3) Polyols (ax-2, ax-3) were obtained in the same manner as in the production of polyol (ax-1) by changing the blending amount (parts by mass) as shown in Table 1.
  • Table 1 shows the number average molecular weight (Mn) of the obtained polyol.
  • Polyol (ax-4) Into a reactor equipped with a stirrer, thermometer, and outflow cooler, 100 parts of L-lactide, 400 parts of ⁇ -caprolactone, 500 parts of P-1010, and 2-ethyloctyl as a catalyst were added as shown in Table 1. 0.1 part of tin oxide was charged. These materials were heated to 170° C. over 5 hours under normal pressure in a nitrogen atmosphere, and then reacted for 3 hours. Distilled water was removed from the system, and a polymerization reaction was carried out. Thereafter, while reducing the pressure to 10 mmHg, the remaining unreacted monomer was removed over 3 hours to obtain polyol (ax-4). The number average molecular weight (Mn) of this polyol (ax-4) was 2,000.
  • Polyol (ax-5 to ax-55, axc-1 to 3) Polyols (ax-5 to ax-55, axc-1 to axc-3) were prepared in the same manner as in the production of polyol (ax-4), except that the amount (parts by mass) was changed as shown in Table 1. got Table 1 shows the number average molecular weight (Mn) of the obtained polyol.
  • the content of each monomer is the content (% by mass) based on the total amount (100% by mass) of the monomer mixture constituting the polyol (ax).
  • Monomer (ax'1)/monomer (ax'2) is the ratio of the content of monomer (ax'1) to the content of monomer (ax'2).
  • Urethane Prepolymer (A) Having a Hydroxyl Group (Urethane Prepolymer (A-1)) 100 parts of polyol (ax-1), 12.1 parts of F-1010, 8.7 parts of HDI, a catalyst 0.04 part of dioctyltin dilaurate and toluene in an amount to give a non-volatile content of 60% were charged as a solution. These materials were gradually heated to 100° C. and reacted for 5 hours. After confirming that the NCO characteristic absorption (2,270 cm ⁇ 1 ) on the IR chart had disappeared, the mixture was cooled to 25° C. and 0.08 part of acetylacetone was added to complete the reaction.
  • the urethane prepolymer (A-1) thus obtained had a weight average molecular weight (Mw) of 50,000 and a glass transition temperature (Tg) of -10°C.
  • NCO/OH is the isocyanate group (NCO) of the polyisocyanate (ay) and the hydroxyl group (OH) of the polyol (ax) when producing the urethane prepolymer (A) having a hydroxyl group. and the molar ratio (NCO/OH).
  • Adhesive Composition and Adhesive Sheet 100 parts of the urethane prepolymer (A-1), 5.0 parts of HDI-TMP as the isocyanate curing agent (B), and ethyl acetate as the solvent were blended so that the non-volatile content was 50%, and the mixture was stirred with a disper. to obtain an adhesive composition.
  • a polyethylene terephthalate (PET) ("Lumirror T-60", manufactured by Toray Industries, Inc.) with a thickness of 50 ⁇ m was prepared as a base material.
  • PET polyethylene terephthalate
  • the previously prepared pressure-sensitive adhesive composition was applied onto the substrate to form a coating layer. Coating was performed at a coating speed of 3 m/min, a width of 30 cm, and a thickness of 25 ⁇ m after drying. Next, the formed coating layer was dried at 100° C. for 1 minute using a drying oven to form an adhesive layer.
  • a commercially available release sheet having a thickness of 38 ⁇ m was adhered to the adhesive layer, and cured under conditions of 23° C. and 50% RH for 1 week to obtain an adhesive sheet 1 .
  • Examples 2 to 82, Comparative Examples 1 to 4 The materials and blending amounts (parts by mass) of Example 1 were changed as shown in Table 3, and the pressure-sensitive adhesive compositions of Examples 2 to 82 and Comparative Examples 1 to 4 were prepared in the same manner as in Example 1, respectively. and an adhesive sheet was obtained.
  • Example 83-88 In the same manner as in Example 1, except that the materials and blending amounts (parts by mass) of Example 1 were changed as shown in Table 3, and the base material was changed to the following biodegradable base material, each example PSA compositions and PSA sheets of 83 to 88 were obtained.
  • ⁇ Biodegradable base material> A biodegradable resin described below was extruded at a temperature of 230° C. using a 30 mm ⁇ inflation extruder (manufactured by Tosoku Seimitsu Kogyo Co., Ltd.) to obtain a biodegradable base material having a thickness of 50 ⁇ m.
  • cellulose manufactured by Nippon Paper Chemicals Co., Ltd., dissolving pulp
  • PBAT polybutylene adipate terephthalate (manufactured by BASF, Ecoflex)
  • PBS Polybutylene succinate (PTT MCC Biochem, BioPBS FZ71)
  • PLA polylactic acid, (manufactured by ThompsoneWorks, 4032D)
  • PHBHHx Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (manufactured by Kaneka, AONILEX)
  • CA cellulose acetate resin (manufactured by Daicel, L-20)
  • the biomass degree of the adhesive is the mass ratio of the biomass-derived raw material used in the production of the adhesive to the total mass of the adhesive, and was calculated according to the following formula (1). In addition, each mass is non-volatile content conversion.
  • the biomass degree is preferably 5% or more, more preferably 10% or more, and even more preferably 25% or more.
  • Biomass degree of adhesive (mass%) 100 ⁇ [mass of raw material derived from biomass (g)] / [total mass of adhesive (g)]
  • the usage ratio of the biodegradable raw material of the adhesive is the mass ratio of the biodegradable raw material used in the production of the adhesive to the total mass of the adhesive, and was calculated according to the following formula (2). .
  • each mass is non-volatile content conversion.
  • the usage ratio is preferably 60% or more.
  • the peel speeds were low peel speed (0.3 m/min) and high peel speed (30 m/min). Evaluation criteria are as follows. (Evaluation criteria) A: The adhesive sheet could be peeled off without staining the SUS plate. excellence. B: The SUS plate was very slightly contaminated. Good. C: The SUS plate was slightly contaminated. Practical. D: The SUS plate was contaminated. Not practical.
  • the pressure-sensitive adhesive sheets produced in Examples and Comparative Examples were cut into pieces having a width of 25 mm and a length of 100 mm, and used as samples. Then, in accordance with JIS Z 0237, the release sheet was peeled off from the sample under an atmosphere of 23° C. and 50% RH, and the exposed adhesive layer was adhered to a polished stainless steel (SUS) plate. After 24 hours of adhesion, the adhesive strength (N/25 mm) was measured using a tensile tester under the conditions of a peel speed of 300 mm/min and a peel angle of 180°. Evaluation criteria are as follows. (Evaluation criteria) A: The adhesive strength is 15 N/25 mm or more. excellence.
  • the adhesive strength is 10 N/25 mm or more and less than 15 N/25 mm. Good.
  • C Adhesive strength of 5 N/25 mm or more and less than 10 N/25 mm. Practical.
  • D The adhesive strength is less than 5 N/25 mm. Not practical.
  • the release sheet was peeled off from the pressure-sensitive adhesive sheets produced in Examples and Comparative Examples, and the exposed pressure-sensitive adhesive layer portion (tip of pressure-sensitive adhesive sheet, width 25 mm, length 25 mm) was adhered to a polished stainless steel (SUS) plate. , and press-bonded once with a 2 kg roll. After that, a load of 1 kg was applied in an atmosphere of 80° C. and held for 70,000 seconds.
  • the evaluation indicates the number of seconds when the sample dropped from the SUS plate. When the sample did not fall, the number of millimeters by which the adhesive layer adhered to the SUS plate (tip of the adhesive sheet) shifted downward due to the load. Evaluation criteria are as follows.
  • a pressure-sensitive adhesive sheet used for evaluation of initial curability was produced as follows.
  • a polyethylene terephthalate (PET) (“Lumirror T-60” manufactured by Toray Industries, Inc.) having a thickness of 50 ⁇ m was prepared as a base material.
  • PET polyethylene terephthalate
  • each pressure-sensitive adhesive composition obtained in Examples and Comparative Examples was applied onto a base material at a coating speed of 30 m/min, a width of 150 cm, and a thickness of 25 ⁇ m after drying. It was coated to form a coating layer.
  • the formed coating layer was dried at 100° C. for 1 minute using a drying oven to form an adhesive layer.
  • a commercially available release sheet having a thickness of 38 ⁇ m was adhered to the adhesive layer, and cured under conditions of 23° C. and 50% RH for 1 week to obtain an adhesive sheet.
  • the release sheet was peeled off, and the state of the surface (coated surface) of the pressure-sensitive adhesive layer exposed after peeling was examined by a finger tack test, and the presence or absence of adhesive residue on the finger was examined. evaluated. Evaluation criteria are as follows. (Evaluation criteria) A: The adhesive did not transfer to the finger. excellence. B: The adhesive was very slightly transferred to the finger. Good. C: The adhesive was slightly transferred to the finger. Practical. D: The adhesive transferred to the finger. Not practical.
  • the pressure-sensitive adhesive composition (Example) of the present invention contains a specific urethane prepolymer (A), so that the biomass degree of the pressure-sensitive adhesive and the usage ratio of biodegradable raw materials in the pressure-sensitive adhesive It was confirmed that even if the viscosity is high, the adhesive property is sufficiently satisfied, the staining resistance is excellent in the moist heat resistance test (low staining resistance), and the adhesion at low temperatures is also excellent.
  • the adhesion at low temperature among the lactide forms (ax'1-2), when L-lactide and D-lactide are used in combination, or when DL-lactide or meso-lactide is used, It was confirmed that better adhesion was obtained. Furthermore, it was confirmed that when meso-lactide was used, particularly excellent removability was obtained.
  • Comparative Examples 1 and 2 show that in the preparation of polyol (ax), a monomer (ax'1) having a lactic acid unit and a monomer (ax' 2) are not used together. Moreover, in Comparative Example 3, the number average molecular weight of the polyol (ax) is outside the range defined by the present invention.
  • the pressure-sensitive adhesive composition of the present invention can achieve desired adhesive properties, resistance to staining in a moisture and heat resistance test, and adhesion at low temperatures by using a specific urethane prepolymer (A). .
  • a specific urethane prepolymer (A) used as the base material
  • properties such as adhesive strength can be enhanced by combining with the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention. can be easily improved. For example, comparing Example 44 with Examples 87 and 88, it can be seen that the use of a biodegradable substrate improves adhesion.

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  • Chemical & Material Sciences (AREA)
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Abstract

Provided is an adhesive composition containing a urethane prepolymer (A) that has a hydroxyl group and is a reaction product of a polyol (ax) with a number average molecular weight of 1,000-45,000, a polyfunctional polyol (ay) (excluding the polyol (ax)), and a polyisocyanate (az), in which the polyol (ax) is a copolymer of a monomer mixture including a monomer (ax'1) having a lactic acid unit and a monomer (ax'2) (excluding lactic acid) having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit, and the urethane prepolymer (A) having a hydroxyl group has a glass transition temperature of -60°C to -10°C inclusive. Also provided is an adhesive sheet having a substrate and an adhesive layer that is provided on at least one surface of the substrate and formed from the adhesive composition.

Description

粘着剤組成物および粘着シートAdhesive composition and adhesive sheet
　本発明の実施形態は、粘着剤組成物およびそれを用いた粘着シートに関する。 An embodiment of the present invention relates to a pressure-sensitive adhesive composition and a pressure-sensitive adhesive sheet using the same.
　例えば、容器の粘着ラベルを構成する粘着剤は、代表的に石油由来の原料を含む。粘着ラベルは、使用後に容器から剥がされ、または容器に貼付されたまま、土中に廃棄される場合がある。この場合、粘着ラベルを構成する粘着剤の分解速度が極めて遅いために、粘着剤は半永久的に土中に残り、さらには土中の生態系を破壊する原因となり得る。また、石油由来の原料を含む製品を焼却した場合には、二酸化炭素が発生し、地球温暖化進行の一つの原因となる。これらのことから、近年、生分解性原料の使用、または再生可能な原料であるバイオマス由来の原料の使用が推奨され始めている。 For example, adhesives that make up adhesive labels on containers typically contain petroleum-derived raw materials. The adhesive label may be peeled off from the container after use, or discarded in the ground while still attached to the container. In this case, since the decomposition rate of the adhesive constituting the adhesive label is extremely slow, the adhesive remains in the soil semi-permanently and may cause destruction of the ecosystem in the soil. In addition, when products containing petroleum-derived raw materials are incinerated, carbon dioxide is generated, which is one of the causes of global warming. For these reasons, in recent years, the use of biodegradable raw materials or the use of renewable raw materials derived from biomass has begun to be recommended.
　粘着剤組成物の原料において、生分解性原料、またはバイオマス由来の原料を使用した、ポリエステルポリマーが知られている。特許文献１では、乳酸とカプロラクトンとを共重合して得られた生分解性ポリエステルポリマー、粘着付与樹脂、およびイソシアネート硬化剤を含有する、粘着剤組成物が開示されている。 Polyester polymers using biodegradable raw materials or biomass-derived raw materials are known as raw materials for adhesive compositions. Patent Document 1 discloses a pressure-sensitive adhesive composition containing a biodegradable polyester polymer obtained by copolymerizing lactic acid and caprolactone, a tackifying resin, and an isocyanate curing agent.
　また、特許文献２では、乳酸と、二塩基酸と、グリコール成分との共重合によって得られ、ガラス転移温度が－７０～－２０℃であり、重量平均分子量が２万～３０万であり、水酸基価が１～１００ｍｇＫＯＨ／ｇであるポリエステルポリマーを含む、粘着剤組成物が開示されている。 Further, in Patent Document 2, it is obtained by copolymerizing lactic acid, dibasic acid and a glycol component, has a glass transition temperature of −70 to −20° C., a weight average molecular weight of 20,000 to 300,000, A pressure sensitive adhesive composition is disclosed comprising a polyester polymer having a hydroxyl value of 1 to 100 mg KOH/g.
　しかし、特許文献１および２に開示されているポリエステルポリマーを用いた粘着剤組成物では、充分な粘着特性を得ることが困難であった。特に、上記ポリエステルポリマーは、ポリマー鎖の主たる結合部位がエステル結合であり、基材への濡れ性が不足しているため、再剥離性が不充分である。さらに、上記ポリエステルポリマーは、耐湿熱条件下において、エステル基の加水分解によって剥離時に凝集破壊が起こり、被着体に対する汚染が生じやすい。また、主たる結合部位のエステル結合は、乳酸の結晶性を高めるため、低温時の被着体に対する密着性が不足し、低温での粘着力が低いという問題もある。 However, with the adhesive compositions using the polyester polymer disclosed in Patent Documents 1 and 2, it was difficult to obtain sufficient adhesive properties. In particular, the polyester polymer described above has an ester bond as the main binding site of the polymer chain, and has insufficient wettability to the base material, resulting in insufficient removability. Furthermore, the polyester polymer described above undergoes cohesive failure at the time of peeling due to hydrolysis of the ester group under moist and heat resistant conditions, and tends to stain the adherend. In addition, since the ester bond at the main binding site increases the crystallinity of lactic acid, there is also the problem of insufficient adhesion to adherends at low temperatures and low adhesive strength at low temperatures.
特開２００４－２３１７９７号公報Japanese Patent Application Laid-Open No. 2004-231797 特開２０１０－３７４６３号公開Japanese Unexamined Patent Publication No. 2010-37463
　このように、生分解性原料、または再生可能な原料であるバイオマス由来の原料を使用したポリエステルポリマーを含む、従来の粘着剤組成物では、粘着特性を満足し、さらに、耐湿熱試験での低汚染性および低温時の密着性といったこれらの特性を充分に満たすことが困難である。
　したがって、本発明の実施形態は、生分解性原料、またはバイオマス由来の原料を使用し、粘着特性、および低温時の密着性に優れ、低汚染性である、粘着剤組成物を提供する。 As described above, conventional PSA compositions containing polyester polymers made from biodegradable raw materials or renewable biomass-derived raw materials satisfy adhesive properties and exhibit low heat resistance in the moisture and heat resistance test. It is difficult to satisfactorily satisfy these properties such as stain resistance and adhesion at low temperatures.
Accordingly, embodiments of the present invention provide a pressure-sensitive adhesive composition that uses a biodegradable raw material or a biomass-derived raw material, has excellent adhesive properties and low-temperature adhesion, and is less polluting.
　本発明者らは、上記課題を解決するために鋭意検討を行い、本発明を完成した。すなわち、本発明の実施形態は以下に関する。しかし、本発明は以下に記載する実施形態に限定されることなく、様々な実施形態を含む。 The present inventors have made intensive studies to solve the above problems and completed the present invention. That is, embodiments of the present invention relate to: However, the present invention includes various embodiments without being limited to the embodiments described below.
　［１］数平均分子量が１，０００～４５，０００であるポリオール（ａｘ）、多官能ポリオール（ａｙ）（ただし、ポリオール（ａｘ）は除く）、およびポリイソシアネート（ａｚ）の反応物である、水酸基を有するウレタンプレポリマー（Ａ）を含み、
　上記ポリオール（ａｘ）は、乳酸単位を有する単量体（ａｘ’１）と、ラクトン単位および脂肪族ヒドロキシカルボン酸単位の少なくともいずれかを有する単量体（ａｘ’２）（ただし、乳酸は除く）とを含む単量体混合物の共重合体であり、
　上記水酸基を有するウレタンプレポリマー（Ａ）は、ガラス転移温度が－６０℃～－１０℃である、粘着剤組成物。 [1] A reaction product of a polyol (ax) having a number average molecular weight of 1,000 to 45,000, a polyfunctional polyol (ay) (excluding the polyol (ax)), and a polyisocyanate (az). Containing a urethane prepolymer (A) having a hydroxyl group,
The polyol (ax) is a monomer (ax'1) having a lactic acid unit and a monomer (ax'2) having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit (excluding lactic acid). ) is a copolymer of a monomer mixture containing
The pressure-sensitive adhesive composition, wherein the hydroxyl group-containing urethane prepolymer (A) has a glass transition temperature of -60°C to -10°C.
　［２］上記ポリオール（ａｘ）の数平均分子量が１０，０００を超え、３５,０００以下である、上記［１］に記載の粘着剤組成物。 [2] The pressure-sensitive adhesive composition according to [1] above, wherein the polyol (ax) has a number average molecular weight of more than 10,000 and not more than 35,000.
　［３］さらにイソシアネート硬化剤（Ｂ）を含む、上記［１］または［２］に記載の粘着剤組成物。 [3] The pressure-sensitive adhesive composition according to [1] or [2] above, further comprising an isocyanate curing agent (B).
　［４］上記水酸基を有するウレタンプレポリマー（Ａ）は、重量平均分子量が１０，０００～２００，０００である、上記［１］～「３」のいずれか１項に記載の粘着剤組成物。 [4] The pressure-sensitive adhesive composition according to any one of [1] to "3" above, wherein the urethane prepolymer (A) having hydroxyl groups has a weight average molecular weight of 10,000 to 200,000.
　［５］上記ポリオール（ａｘ）を構成する単量体混合物の全質量を基準として、上記単量体（ａｘ’１）と、上記単量体（ａｘ’２）との合計含有率が１０～９９．８質量％である、上記［１］～［４］のいずれか１項に記載の粘着剤組成物。 [5] Based on the total mass of the monomer mixture constituting the polyol (ax), the total content of the monomer (ax'1) and the monomer (ax'2) is 10 to The pressure-sensitive adhesive composition according to any one of [1] to [4] above, which is 99.8% by mass.
　［６］上記単量体（ａｘ’２）が、少なくともＭｅｓｏ－ラクチドを含む、上記［１］～［５］のいずれか１項に記載の粘着剤組成物。 [6] The adhesive composition according to any one of [1] to [5] above, wherein the monomer (ax'2) contains at least Meso-lactide.
　［７］上記ポリオール（ａｘ）を構成する単量体混合物が、上記単量体（ａｘ’１）および上記単量体（ａｘ’２）と反応可能な単量体（ａｘ’３）をさらに含み、
　上記単量体（ａｘ’３）が、２００～２,０００の数平均分子量を有するポリエステルポリオールを含む、上記［１］～［６］のいずれか１項に記載の粘着剤組成物。 [7] The monomer mixture constituting the polyol (ax) further includes a monomer (ax'3) capable of reacting with the monomer (ax'1) and the monomer (ax'2). including
The pressure-sensitive adhesive composition according to any one of [1] to [6] above, wherein the monomer (ax'3) comprises a polyester polyol having a number average molecular weight of 200 to 2,000.
　［８］基材と、上記基材の少なくとも一方の面に設けられた、上記［１］～［７］のいずれか１項に記載の粘着剤組成物から形成されてなる粘着剤層とを有する粘着シート。 [8] A base material, and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of [1] to [7] provided on at least one surface of the base material Adhesive sheet with.
　［９］上記基材が、生分解性基材である、上記［８］に記載の粘着シート。 [9] The pressure-sensitive adhesive sheet according to [8] above, wherein the base material is a biodegradable base material.
　［１０］上記生分解性基材が、多糖類、ポリビニルアルコール樹脂、および生分解性ポリエステル樹脂からなる群から選択される少なくとも１種を含む、上記［９］に記載の粘着シート。 [10] The adhesive sheet according to [9] above, wherein the biodegradable base material contains at least one selected from the group consisting of polysaccharides, polyvinyl alcohol resins, and biodegradable polyester resins.
　本発明によれば、バイオマス度および生分解性原料の使用比率が高い粘着剤組成物であって、粘着特性を充分に満足し、さらに、耐湿熱試験での被着体に対する汚染性が低く、かつ低温時の密着性にも優れる、粘着剤組成物の提供が可能となる。また、上記粘着剤組成物を用いた粘着シートの提供が可能となる。
　本願の開示は、２０２１年４月１４日に出願された特願２０２１－０６８３７７号に記載の主題と関連しており、これら全ての開示内容は引用によりここに援用される。 According to the present invention, the pressure-sensitive adhesive composition has a high degree of biomass and a high biodegradable raw material usage ratio, sufficiently satisfies the adhesive properties, and has low contamination to the adherend in the heat and humidity resistance test, It is also possible to provide a pressure-sensitive adhesive composition that is excellent in adhesion at low temperatures. Moreover, it becomes possible to provide a pressure-sensitive adhesive sheet using the pressure-sensitive adhesive composition.
The disclosure of the present application relates to the subject matter described in Japanese Patent Application No. 2021-068377 filed on April 14, 2021, and all disclosures thereof are incorporated herein by reference.
　本発明の説明の前に用語を定義する。
　本明細書で記載する「粘着シート」とは、基材と、本発明の粘着剤組成物の硬化物からなる粘着剤層とを含むことを意味する。 Terms are defined prior to describing the present invention.
The "adhesive sheet" described in this specification means containing a substrate and an adhesive layer comprising a cured product of the adhesive composition of the present invention.
　本明細書において「～」を用いて特定される数値範囲は、「～」の前後に記載される数値を下限値および上限値の範囲として含むことを意味する。
　本明細書に記載する各種成分は、特に注釈しない限り、それぞれ独立して１種を単独で使用しても、２種以上を併用してもよい。 In this specification, a numerical range specified using "to" means to include the numerical values described before and after "to" as a range of lower and upper values.
Unless otherwise noted, the various components described herein may be independently used singly or in combination of two or more.
　本明細書において、乳酸単位を有する単量体（ａｘ’１）、ラクトン単位および脂肪族ヒドロキシカルボン酸単位の少なくともいずれかを有する単量体（ａｘ’２）、およびその他単量体（ａｘ’３）を、それぞれ、単量体（ａｘ’１）、単量体（ａｘ’２）、および単量体（ａｘ’３）と略記することがある。また、水酸基を有するウレタンプレポリマー（Ａ）をウレタンプレポリマー（Ａ）と略記することがある。 In this specification, a monomer having a lactic acid unit (ax'1), a monomer having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit (ax'2), and other monomers (ax' 3) may be abbreviated as monomer (ax'1), monomer (ax'2), and monomer (ax'3), respectively. Moreover, the urethane prepolymer (A) having a hydroxyl group may be abbreviated as urethane prepolymer (A).
　本明細書において、「Ｍｗ」は、ゲルパーミエーションクロマトグラフィ（ＧＰＣ）測定によって求めたポリスチレン換算の重量平均分子量である。「Ｍｎ」は、ＧＰＣ測定によって求めたポリスチレン換算の数平均分子量である。これらは、［実施例］の項に記載する方法によって測定することができる。 In the present specification, "Mw" is the polystyrene equivalent weight average molecular weight obtained by gel permeation chromatography (GPC) measurement. "Mn" is the polystyrene-equivalent number-average molecular weight determined by GPC measurement. These can be measured by the methods described in the [Examples] section.
　以下、本発明の実施形態を詳細に説明する。ただし、以下の説明は、本発明の実施態様の一例（代表例）であり、本発明はその要旨を超えない限り、これらの内容に限定されない。 Hereinafter, embodiments of the present invention will be described in detail. However, the following description is an example (representative example) of embodiments of the present invention, and the present invention is not limited to these contents as long as the gist thereof is not exceeded.
＜１＞粘着剤組成物
　本発明の一実施形態である粘着剤組成物は、水酸基を有するウレタンプレポリマー（Ａ）を少なくとも含む。上記粘着剤組成物は、必要に応じて、硬化剤、粘着付与樹脂、可塑剤、またはその他任意成分をさらに含んでよい。上記粘着剤組成物は、さらに溶剤を含んでよい。 <1> Adhesive composition The adhesive composition which is one embodiment of the present invention contains at least a urethane prepolymer (A) having a hydroxyl group. The pressure-sensitive adhesive composition may further contain a curing agent, a tackifying resin, a plasticizer, or other optional components, if necessary. The pressure-sensitive adhesive composition may further contain a solvent.
　本発明の一実施形態である粘着剤組成物は、分子内にウレタン結合を有する、特定のウレタンプレポリマー（Ａ）を含むことで、基材への濡れ性が向上し、優れた再剥離性が得られる。また、耐湿熱試験において、ポリマーにおける結合部位の分解が抑制されるため、被着体に対する汚染性が低い。さらに、ポリマーにおいて乳酸由来の結晶性が抑制されるため、粘着特性に優れるだけでなく、低温時の被着体に対する密着性についても良好となり、これら性能を満足することができる。 The pressure-sensitive adhesive composition, which is one embodiment of the present invention, contains a specific urethane prepolymer (A) having urethane bonds in the molecule, thereby improving wettability to the substrate and excellent removability. is obtained. In addition, in the heat and humidity resistance test, the decomposition of the bonding sites in the polymer is suppressed, so the adherend is less likely to stain. Furthermore, since the crystallinity derived from lactic acid is suppressed in the polymer, not only is the adhesive property excellent, but also the adhesion to the adherend at low temperatures is improved, and these performances can be satisfied.
＜ウレタンプレポリマー（Ａ）＞
　ウレタンプレポリマー（Ａ）は、ポリオール（ａｘ）と、多官能ポリオール（ａｙ）（ただし、ポリオール（ａｘ）は除く）と、ポリイソシアネート（ａｚ）との反応物である、水酸基を有するウレタンプレポリマーである。 <Urethane prepolymer (A)>
Urethane prepolymer (A) is a urethane prepolymer having a hydroxyl group, which is a reaction product of polyol (ax), polyfunctional polyol (ay) (excluding polyol (ax)), and polyisocyanate (az). is.
　上記「反応物」とは、ポリオール（ａｘ）と、多官能ポリオール（ａｙ）と、ポリイソシアネート（ａｚ）との反応生成物を意味する。ポリオール（ａｘ）は、１分子中に２つの水酸基を有することが好ましい。また、多官能ポリオール（ａｙ）は、１分子中に２つ以上の水酸基を有することが好ましい。ポリイソシアネート（ａｚ）は、１分子中に２つのイソシアネート基を有する２官能イソシアネート（ジイソシアネートともいう）が好ましい。ポリイソシアネート（ａｚ）のイソシアネート基（イソシアナト基）は、ポリオール（ａｘ）および多官能ポリオール（ａｙ）を合計した水酸基よりも少なくなるようなモル比（ＮＣＯ／ＯＨ）で使用する。これにより、得られるウレタンプレポリマーは、水酸基を有するウレタンプレポリマーとなる。 The above "reactant" means a reaction product of polyol (ax), polyfunctional polyol (ay), and polyisocyanate (az). Polyol (ax) preferably has two hydroxyl groups in one molecule. Moreover, the polyfunctional polyol (ay) preferably has two or more hydroxyl groups in one molecule. Polyisocyanate (az) is preferably bifunctional isocyanate (also referred to as diisocyanate) having two isocyanate groups in one molecule. The isocyanate groups (isocyanato groups) of the polyisocyanate (az) are used at a molar ratio (NCO/OH) that is less than the total hydroxyl groups of the polyol (ax) and polyfunctional polyol (ay). Thereby, the obtained urethane prepolymer becomes a urethane prepolymer having a hydroxyl group.
　上記ポリオール（ａｘ）は、乳酸単位を有する単量体（ａｘ’１）と、ラクトン単位および脂肪族ヒドロキシカルボン酸単位の少なくともいずれかを有する単量体（ａｘ’２）（ただし、乳酸は除く）とを含む単量体混合物の共重合体である。上記ポリオール（ａｘ）を構成する単量体混合物が、単量体（ａｘ’１）と単量体（ａｘ’２）とを含むことによって、ウレタンプレポリマー（Ａ）のガラス転移温度、および乳酸由来の結晶性をそれぞれ適度に制御可能となり、低温時の密着性および粘着力が充分に得られる。 The polyol (ax) is a monomer (ax'1) having a lactic acid unit and a monomer (ax'2) having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit (excluding lactic acid). ) is a copolymer of a monomer mixture containing By including the monomer (ax'1) and the monomer (ax'2) in the monomer mixture constituting the polyol (ax), the glass transition temperature of the urethane prepolymer (A) and lactic acid It becomes possible to appropriately control the derived crystallinity, respectively, and sufficient adhesion and adhesive strength at low temperatures can be obtained.
　上記ポリオール（ａｘ）の数平均分子量（Ｍｎ）は、１，０００～４５，０００以下であってよい。上記Ｍｎが上記範囲内であることで、ウレタン結合を適度に導入することができる。ウレタン結合の導入により、耐湿熱試験においてポリマーにおける結合部位の分解が抑制され、被着体に対する汚染性が低くなる。また、凝集力の向上によって、粘着力が向上する。さらに、濡れ性が向上し、再剥離性も向上する。 The number average molecular weight (Mn) of the polyol (ax) may be 1,000 to 45,000 or less. When the Mn is within the above range, a urethane bond can be appropriately introduced. The introduction of the urethane bond suppresses the decomposition of the bonding site in the polymer in the heat and humidity resistance test, and reduces the contamination of the adherend. In addition, the cohesive strength is improved, and the adhesive strength is improved. Furthermore, the wettability is improved and the removability is also improved.
　上記ウレタンプレポリマー（Ａ）のガラス転移温度（Ｔｇ）は、－６０℃～－１０℃である。上記Ｔｇは、より好ましくは－５０℃～－１２℃であり、さらに好ましくは－４５℃～－１５℃である。
　ガラス転移温度が上記範囲内である場合、ポリマー鎖の絡み合いによって適度な凝集力となり、充分な粘着力が得られる。具体的には、ガラス転移温度を－６０℃以上に調整した場合、充分な凝集力が得られ、粘着力を容易に高めることができる。また、ガラス転移温度を－１０℃以下に調整した場合、低温時の凝集力が過度に高まることを抑制でき、低温時の優れた密着性、および優れた粘着特性を容易に得ることができる。 The glass transition temperature (Tg) of the urethane prepolymer (A) is -60°C to -10°C. The above Tg is more preferably -50°C to -12°C, still more preferably -45°C to -15°C.
When the glass transition temperature is within the above range, the entanglement of the polymer chains provides an appropriate cohesive force and sufficient adhesive force. Specifically, when the glass transition temperature is adjusted to −60° C. or higher, a sufficient cohesive force can be obtained, and the adhesive force can be easily increased. In addition, when the glass transition temperature is adjusted to −10° C. or lower, excessive increase in cohesive force at low temperatures can be suppressed, and excellent adhesion at low temperatures and excellent adhesive properties can be easily obtained.
　一実施形態において、ウレタンプレポリマー（Ａ）は、数平均分子量が１，０００～４５，０００であるポリオール（ａｘ）と、多官能ポリオール（ａｙ）（ただし、ポリオール（ａｘ）は除く）と、ポリイソシアネート（ａｚ）との反応物である、水酸基を有するウレタンプレポリマーであり、ガラス転移温度が－６０℃～－１０℃である。 In one embodiment, the urethane prepolymer (A) comprises a polyol (ax) having a number average molecular weight of 1,000 to 45,000, a polyfunctional polyol (ay) (excluding the polyol (ax)), It is a urethane prepolymer having a hydroxyl group, which is a reactant with polyisocyanate (az), and has a glass transition temperature of -60°C to -10°C.
　上述のように、数平均分子量が１，０００～４５，０００であるポリオール（ａｘ）を用い、かつガラス転移温度が、－６０～－１０℃であるウレタンプレポリマー（Ａ）によれば、バイオマス度または生分解性原料の使用比率を高めるために、バイオマス原料または生分解性原料である単量体（ａｘ’１）と単量体（ａｘ’２）とを多量に用いた場合でも、耐湿熱試験での汚染性が低く、低温時の密着性、および粘着特性に優れた粘着剤組成物を容易に構成することができる。 As described above, the urethane prepolymer (A) using a polyol (ax) having a number average molecular weight of 1,000 to 45,000 and having a glass transition temperature of −60 to −10° C. enables biomass Even when a large amount of the monomer (ax'1) and the monomer (ax'2), which are biomass or biodegradable raw materials, are used in order to increase the degree or the usage ratio of biodegradable raw materials, moisture resistance A pressure-sensitive adhesive composition with low contamination in a thermal test and excellent low-temperature adhesion and adhesive properties can be easily prepared.
　ウレタンプレポリマー（Ａ）の重量平均分子量は、１０，０００～２００，０００が好ましく、より好ましくは３０，０００～１８０，０００であり、さらに好ましくは４０，０００～１５０，０００である。ウレタンプレポリマー（Ａ）の重量平均分子量を上記範囲内に調整した場合、ポリマー鎖の絡み合いによる凝集力を付与することができ、粘着力を高めることが容易となる。また、上記粘着力の向上に加えて、ウレタン化によって形成されるウレタン結合による濡れ性の向上および凝集力の向上が可能となるため、再剥離性の付与および高粘着力化がより容易となるために好ましい。特に、重量平均分子量を２００，０００以下に調整した場合は、凝集力の低下によって保持力が低下することを抑制できる点で好ましい。 The weight average molecular weight of the urethane prepolymer (A) is preferably 10,000 to 200,000, more preferably 30,000 to 180,000, still more preferably 40,000 to 150,000. When the weight average molecular weight of the urethane prepolymer (A) is adjusted within the above range, it is possible to impart a cohesive force due to the entanglement of the polymer chains, making it easy to increase the adhesive force. In addition to the above-mentioned improvement in adhesive strength, it is possible to improve wettability and cohesive strength due to the urethane bonds formed by urethanization, making it easier to impart removability and increase adhesive strength. preferred for In particular, when the weight-average molecular weight is adjusted to 200,000 or less, it is preferable in that it is possible to suppress a decrease in holding power due to a decrease in cohesion.
　以下、粘着剤組成物の構成成分についてより具体的に説明する。
［ポリオール（ａｘ）］
　一実施形態において、ポリオール（ａｘ）は、乳酸単位を有する単量体（ａｘ’１）と、ラクトン単位を有する単量体および脂肪族ヒドロキシカルボン酸単位を有する単量体（ただし、乳酸は除く）の少なくともいずれかの単量体（ａｘ’２）とを含む単量体混合物の共重合によって得られる。上記単量体混合物は、必要に応じて、その他単量体（ａｘ’３）をさらに含んでもよい。その他単量体（ａｘ’３）を適切に選択することで、ポリオールの分子量を制御することが容易となり、所望とする数平均分子量を有するポリオール（ａｘ）を容易に得ることができる。 The constituent components of the pressure-sensitive adhesive composition will be described in more detail below.
[Polyol (ax)]
In one embodiment, the polyol (ax) is a monomer (ax'1) having a lactic acid unit, a monomer having a lactone unit, and a monomer having an aliphatic hydroxycarboxylic acid unit (excluding lactic acid ) and at least one of the monomers (ax′2). The monomer mixture may further contain other monomers (ax'3) as necessary. By appropriately selecting the other monomer (ax'3), it becomes easy to control the molecular weight of the polyol, and the polyol (ax) having the desired number average molecular weight can be easily obtained.
　ポリオール（ａｘ）を構成する単量体混合物の全質量を基準として、単量体（ａｘ’１）と単量体（ａｘ’２）との合計含有率は、１０～９９．８質量％であることが好ましく、５０～９９．８質量％がより好ましく、６０～９９．８質量％がさらに好ましい。上記合計含有率が上記範囲内である場合、ウレタンプレポリマー（Ａ）のガラス転移温度を適切な範囲に容易に調整することができ、粘着特性を容易に向上できる点で好ましい。 Based on the total mass of the monomer mixture constituting the polyol (ax), the total content of the monomer (ax'1) and the monomer (ax'2) is 10 to 99.8% by mass. preferably 50 to 99.8% by mass, even more preferably 60 to 99.8% by mass. When the total content is within the above range, the glass transition temperature of the urethane prepolymer (A) can be easily adjusted to an appropriate range, and adhesive properties can be easily improved, which is preferable.
　バイオマス度、または生分解性原料の使用比率を高める場合には、バイオマス原料または生分解性原料である単量体（ａｘ’１）および単量体（ａｘ’２）の少なくともいずれかの含有率を高めることが好ましい。一実施形態において、単量体（ａｘ’１）および単量体（ａｘ’２）が、いずれもバイオマス原料または生分解性原料の単量体であることが特に好ましい。他の実施形態において、バイオマス度、または生分解性原料の使用比率を高めるために、バイオマス原料または生分解性原料である単量体（ａｘ’３）の含有率を高めることもできる。 When increasing the degree of biomass or the usage ratio of biodegradable raw materials, the content of at least one of monomer (ax'1) and monomer (ax'2) which are biomass raw materials or biodegradable raw materials It is preferable to increase In one embodiment, it is particularly preferred that both the monomer (ax'1) and the monomer (ax'2) are biomass feedstock or biodegradable feedstock monomers. In another embodiment, the content of the monomer (ax'3), which is a biomass raw material or a biodegradable raw material, can be increased in order to increase the biomass degree or the usage ratio of the biodegradable raw material.
　本発明の一実施形態の粘着剤組成物によれば、バイオマス度または生分解性原料の使用比率を高めるために、単量体（ａｘ’１）と単量体（ａｘ’２）とを多量に用いた場合でも、または、単量体（ａｘ’３）の含有率を高めた場合でも、粘着特性に優れるだけでなく、耐湿熱試験での汚染性が低く、および低温時の密着性に優れた粘着剤組成物を提供することができる。 According to the pressure-sensitive adhesive composition of one embodiment of the present invention, a large amount of the monomer (ax'1) and the monomer (ax'2) is added in order to increase the biomass degree or the usage ratio of biodegradable raw materials. or even when the content of the monomer (ax'3) is increased, it not only has excellent adhesive properties, but also has low staining resistance in a moisture and heat resistance test, and has good adhesion at low temperatures. An excellent adhesive composition can be provided.
　ポリオール（ａｘ）を構成する単量体混合物における単量体（ａｘ’１）の含有量と単量体（ａｘ’２）の含有量との比率（ａｘ’１）／（ａｘ’２）は、１０／９０～９０／１０が好ましく、より好ましくは、２０／８０～８０／２０であり、さらに好ましくは、３０／７０～７０／３０である。一実施形態において、上記比率（ａｘ’１）／（ａｘ’２）は、４０／６０～６０／４０であることがさらにより好ましく、５０／５０であることが最も好ましい。
　上記比率（ａｘ’１）／（ａｘ’２）を上記範囲内に調整することによって、粘着剤中のバイオマス度が高く、かつ生分解性原料の使用比率が高い場合でも、所望する粘着特性を容易に得ることができる。 The ratio (ax'1)/(ax'2) between the content of the monomer (ax'1) and the content of the monomer (ax'2) in the monomer mixture constituting the polyol (ax) is , preferably 10/90 to 90/10, more preferably 20/80 to 80/20, still more preferably 30/70 to 70/30. In one embodiment, the ratio (ax'1)/(ax'2) is even more preferably 40/60 to 60/40, most preferably 50/50.
By adjusting the ratio (ax'1) / (ax'2) within the above range, the desired adhesive properties can be achieved even when the biomass degree in the adhesive is high and the usage ratio of biodegradable raw materials is high. can be obtained easily.
　ポリオール（ａｘ）の数平均分子量（Ｍｎ）は、１，０００以上であってよく、好ましくは２，５００以上であってよい。一方、上記Ｍｎは、４５，０００以下であってよく、好ましくは４０，０００以下であり、より好ましくは３７，０００以下であり、さらに好ましくは３５，０００であってよい。
　一実施形態において、上記Ｍｎは、１，０００～４５，０００であってよい。上記Ｍｎは、好ましくは１，０００～３５，０００であってよく、さらに好ましくは２，５００～３５，０００であってよい。 The number average molecular weight (Mn) of polyol (ax) may be 1,000 or more, preferably 2,500 or more. On the other hand, the Mn may be 45,000 or less, preferably 40,000 or less, more preferably 37,000 or less, and even more preferably 35,000.
In one embodiment, the Mn may be from 1,000 to 45,000. The above Mn may be preferably 1,000 to 35,000, more preferably 2,500 to 35,000.
　上記Ｍｎを上記範囲内に調整した場合、ウレタン結合による濡れ性および凝集力を容易に制御できる。具体的には、上記Ｍｎを１，０００以上に調整した場合、ウレタン化により得られるポリマーのウレタン結合数が多くなり過ぎることを抑制できる。すなわち、耐湿熱性等の加熱下での試験において、ウレタン基の再配列に伴い密着性が過度に向上し、凝集破壊を生じることを抑制でき、そのことによって、被着体に対する汚染性の改善が容易となる。また、上記Ｍｎを４５，０００以下に調整した場合、ウレタン結合数が不足し、耐湿熱性、および再剥離性が悪化することを抑制できる。 When the above Mn is adjusted within the above range, the wettability and cohesive force due to the urethane bond can be easily controlled. Specifically, when the Mn is adjusted to 1,000 or more, it is possible to prevent the number of urethane bonds in the polymer obtained by urethanization from becoming too large. That is, in a test under heating such as resistance to moist heat, the rearrangement of the urethane groups excessively improves the adhesion and suppresses the occurrence of cohesive failure, thereby improving the staining resistance to the adherend. easier. Moreover, when the above Mn is adjusted to 45,000 or less, it is possible to suppress the deterioration of the moist heat resistance and the removability due to the insufficient number of urethane bonds.
　一実施形態において、より優れた再剥離性が容易に得られる観点から、ポリオール（ａｘ）のＭｎは、１０，０００を超え、３５,０００以下であってよい。上記Ｍｎは、より好ましくは１１，０００～３０，０００であってよく、さらに好ましくは１１，０００～２５，０００であってよい。 In one embodiment, the Mn of the polyol (ax) may exceed 10,000 and be 35,000 or less from the viewpoint of easily obtaining superior removability. The above Mn may be more preferably 11,000 to 30,000, and even more preferably 11,000 to 25,000.
　他の実施形態において、ポリオール（ａｘ）のＭｎは、１，０００～１０，０００であってよく、より好ましくは２，０００～７，５００であってよい。 In another embodiment, the Mn of polyol (ax) may be from 1,000 to 10,000, more preferably from 2,000 to 7,500.
（単量体（ａｘ’１））
　乳酸単位を有する単量体（ａｘ’１）は、乳酸単位を有していればよく、特に限定されない。例えば、Ｌ－乳酸、Ｄ－乳酸等の乳酸体（ａｘ’１－１）、Ｌ－ラクチド、Ｄ－ラクチド、ＤＬ－ラクチド、ｍｅｓｏ－ラクチド等のラクチド体（ａｘ’１－２）などが挙げられる。このような乳酸単位を有する単量体（ａｘ’１）と、後述する単量体（ａｘ’２）とを共重合させることによって、所望の特性を有するウレタンプレポリマー（Ａ）を得ることができる。上記乳酸単位を有する単量体（ａｘ’１）は、１種または２種以上を組み合わせて使用できる。 (monomer (ax'1))
The monomer (ax'1) having a lactic acid unit is not particularly limited as long as it has a lactic acid unit. Examples include lactic acid forms (ax′1-1) such as L-lactic acid and D-lactic acid, lactide forms (ax′1-2) such as L-lactide, D-lactide, DL-lactide and meso-lactide. be done. A urethane prepolymer (A) having desired properties can be obtained by copolymerizing a monomer (ax'1) having such a lactic acid unit and a monomer (ax'2) described later. can. The lactic acid unit-containing monomer (ax'1) can be used singly or in combination of two or more.
　なお、本明細書における「乳酸単位」とは、乳酸の部分構造である「－Ｏ－ＣＨ（ＣＨ３）―ＣＯ－」単位を意味する。
　乳酸体（ａｘ’１－１）とラクチド体（ａｘ’１－２）とでは、ラクチド体（ａｘ’１－２）がより好ましい。ラクチド体は、反応性の観点で、共重合性に優れ結晶化度を低くすることができ、そのことにより再剥離性を容易に向上できる。 The term "lactic acid unit" as used herein means a "--O--CH(CH3)--CO--" unit, which is a partial structure of lactic acid.
Lactide (ax'1-2) is more preferred between lactic acid (ax'1-1) and lactide (ax'1-2). From the viewpoint of reactivity, the lactide compound has excellent copolymerizability and can lower the degree of crystallinity, thereby easily improving removability.
　乳酸体（ａｘ’１－１）とラクチド体（ａｘ’１－２）は、バイオマス由来の原料であり、かつ生分解性原料である。このなかでも、ポリオール製造時の反応性制御および溶剤への溶解性の観点から、ラクチド体（ａｘ’１－２）が好ましい。ラクチド体（ａｘ’１－２）は、Ｌ－ラクチド、Ｄ－ラクチド、ＤＬ－ラクチド、およびｍｅｓｏ－ラクチドからなる群から選択される少なくとも１種を含む。ここで、ＤＬ－ラクチドとは、Ｌ－ラクチドとＤ－ラクチドとの等モル混合物を意味する。 Lactate (ax'1-1) and lactide (ax'1-2) are biomass-derived raw materials and biodegradable raw materials. Among these, the lactide form (ax'1-2) is preferable from the viewpoint of reactivity control during polyol production and solubility in solvents. The lactide form (ax'1-2) includes at least one selected from the group consisting of L-lactide, D-lactide, DL-lactide, and meso-lactide. Here, DL-lactide means an equimolar mixture of L-lactide and D-lactide.
　乳酸由来の結晶化度を低下させ低温時の密着性を向上する観点から、ラクチド体（ａｘ’１－２）としては、Ｌ－ラクチドとＤ－ラクチドとの併用、ＤＬ－ラクチド、またはｍｅｓｏ－ラクチドが好ましい。特に、非晶性で濡れ性を向上させ再剥離性をより向上させる観点から、ｍｅｓｏ－ラクチドが好ましい。
　Ｌ－ラクチドおよびＤ－ラクチドを併用する場合には、Ｌ－ラクチド／Ｄ－ラクチドの重量比は、５／９５～９５／５であることが好ましく、より好ましくは、１５／８５～８５／１５である。この範囲内となることで、ウレタンプレポリマー（Ａ）中の乳酸の結晶化度を低くすることができ、低温時の密着性を向上できる。 From the viewpoint of reducing the crystallinity derived from lactic acid and improving the adhesion at low temperatures, the lactide form (ax'1-2) includes a combination of L-lactide and D-lactide, DL-lactide, or meso-lactide. Lactide is preferred. In particular, meso-lactide is preferable from the viewpoint of being amorphous and improving wettability and further improving removability.
When L-lactide and D-lactide are used in combination, the weight ratio of L-lactide/D-lactide is preferably 5/95 to 95/5, more preferably 15/85 to 85/15. is. Within this range, the degree of crystallinity of lactic acid in the urethane prepolymer (A) can be lowered, and the adhesion at low temperatures can be improved.
　一実施形態において、乳酸単位を有する単量体（ａｘ’１）は、少なくともｍｅｓｏ－ラクチドを含むことが好ましい。一実施形態において、乳酸単位を有する単量体（ａｘ’１）は、ｍｅｓｏ－ラクチドに加えて、Ｌ－ラクチド、Ｄ－ラクチド、ＤＬ－ラクチドといった他のラクチド体をさらに含んでもよい。例えば、ｍｅｓｏ－ラクチドの製造では、その精製段階でｍｅｓｏ－ラクチド以外のラクチド体が取り除かれる。しかし、本実施形態では、未精製のｍｅｓｏ－ラクチドを使用してもよい。すなわち、ｍｅｓｏ－ラクチド以外に、Ｌ－ラクチド、Ｄ－ラクチド、およびＤＬ－ラクチドの少なくとも１種が混在していてもよい。 In one embodiment, the monomer (ax'1) having a lactic acid unit preferably contains at least meso-lactide. In one embodiment, the monomer having a lactic acid unit (ax'1) may further contain other lactide forms such as L-lactide, D-lactide and DL-lactide in addition to meso-lactide. For example, in the production of meso-lactide, the purification step removes lactide forms other than meso-lactide. However, in this embodiment, unpurified meso-lactide may be used. That is, in addition to meso-lactide, at least one of L-lactide, D-lactide and DL-lactide may be mixed.
　単量体（ａｘ’１）の含有率は、ポリオール（ａ）を構成する単量体混合物の全質量を基準として、５～９２質量％であることが好ましく、１５～７０質量％がより好ましい。上記含有率を上記範囲内に調整した場合、ウレタンプレポリマー（Ａ）のガラス転移温度を適切に調整でき、低温時の優れた基材密着性、および優れた粘着力が容易に得られる点で好ましい。 The content of the monomer (ax'1) is preferably 5 to 92% by mass, more preferably 15 to 70% by mass, based on the total mass of the monomer mixture constituting the polyol (a). . When the above content is adjusted within the above range, the glass transition temperature of the urethane prepolymer (A) can be adjusted appropriately, and excellent adhesion to the substrate at low temperatures and excellent adhesive strength can be easily obtained. preferable.
（単量体（ａｘ’２））
　単量体（ａｘ’２）は、ラクトン単位および脂肪族ヒドロキシカルボン酸単位の少なくとも一方を有する単量体である。一実施形態において、単量体（ａｘ’２）として、１種の単量体を使用しても、または２種以上の単量体を使用してもよい。
　一実施形態において、単量体（ａｘ’２）は、脂肪族ヒドロキシカルボン酸単位を有する単量体（ａｘ’２－１）（ただし、乳酸は除く）、およびラクトン単位を有する単量体（ａｘ’２－２）の少なくとも一方であってよい。一実施形態において、単量体（ａｘ’２）は、ラクトン単位を有する単量体（ａｘ’２－２）を少なくとも含むことが好ましい。 (monomer (ax'2))
Monomer (ax'2) is a monomer having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit. In one embodiment, one monomer or two or more monomers may be used as the monomer (ax'2).
In one embodiment, the monomer (ax'2) is a monomer (ax'2-1) having an aliphatic hydroxycarboxylic acid unit (excluding lactic acid) and a monomer having a lactone unit ( ax'2-2). In one embodiment, the monomer (ax'2) preferably contains at least a monomer (ax'2-2) having a lactone unit.
　これらの単量体（ａｘ’２）を、乳酸単位を有する単量体（ａｘ’１）と共重合させることによって、ウレタンプレポリマー（Ａ）中の乳酸成分の結晶化度を低下させ、ガラス転移温度を適切な範囲に調整できる。その結果、粘着剤組成物において優れた粘着力などの特性を実現できるウレタンプレポリマー（Ａ）を得ることができる。 By copolymerizing these monomers (ax'2) with monomers (ax'1) having lactic acid units, the degree of crystallinity of the lactic acid component in the urethane prepolymer (A) is reduced, and glass The transition temperature can be adjusted within an appropriate range. As a result, it is possible to obtain a urethane prepolymer (A) capable of realizing properties such as excellent adhesive strength in the pressure-sensitive adhesive composition.
　脂肪族ヒドロキシカルボン酸単位を有する単量体（ａｘ’２－１）としては、例えば、グリコール酸、３－ヒドロキシ酪酸、４－ヒドロキシ酪酸、３－ヒドロキシ吉草酸、４－ヒドロキシ吉草酸、６－ヒドロキシカプロン酸等が挙げられる。
　ラクトン単位を有する単量体（ａｘ’２－２）としては、例えば、炭素数３～１２のラクトン等が挙げられる。例えば、β－プロピオラクトン、β－ブチロラクトン、δ－バレロラクトン、ε－カプロラクトン、エナントラクトン、カプリロラクトン、ラウロラクトン等が挙げられる。 Examples of the monomer (ax'2-1) having an aliphatic hydroxycarboxylic acid unit include glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 6- hydroxycaproic acid and the like.
Examples of the monomer (ax'2-2) having a lactone unit include lactones having 3 to 12 carbon atoms. Examples include β-propiolactone, β-butyrolactone, δ-valerolactone, ε-caprolactone, enantholactone, caprylolactone, laurolactone and the like.
　脂肪族ヒドロキシカルボン酸単位を有する単量体（ａｘ’２－１）と、ラクトン単位を有する単量体（ａｘ’２－２）とでは、ラクトン単位を有する単量体（ａｘ’２－２）の方が好ましい。ラクトン単位を有する単量体（ａｘ’２－２）は、反応性の観点で共重合性に優れ、また乳酸成分の結晶化度を容易に低くすることができるため、再剥離性を容易に向上させることができる。
　ラクトン単位を有する単量体（ａｘ’２－２）のなかでも、生分解性を有する観点から、ε－カプロラクトン、または６－ヒドロキシカプロン酸が好ましい。上記ラクトン単位を有する単量体（ａｘ’２－２）は、１種のみで使用しても、または２種以上を組み合わせて使用してもよい。 In the monomer having an aliphatic hydroxycarboxylic acid unit (ax'2-1) and the monomer having a lactone unit (ax'2-2), the monomer having a lactone unit (ax'2-2 ) is preferred. The monomer (ax′2-2) having a lactone unit is excellent in copolymerizability from the viewpoint of reactivity, and can easily lower the crystallinity of the lactic acid component, so that the removability can be easily improved. can be improved.
Among the monomers (ax'2-2) having a lactone unit, ε-caprolactone or 6-hydroxycaproic acid is preferred from the viewpoint of biodegradability. The lactone unit-containing monomer (ax'2-2) may be used alone or in combination of two or more.
　単量体（ａｘ’２）の含有率は、ポリオール（ａｘ）を構成する単量体混合物の全質量を基準として、５～９２質量％であることが好ましく、１８～７０質量％がより好ましい。含有率を上記範囲内に調整した場合、ウレタンプレポリマー（Ａ）のガラス転移温度を適切に調整でき、低温時の優れた密着性、および優れた粘着力が容易に得られる点で好ましい。 The content of the monomer (ax'2) is preferably 5 to 92% by mass, more preferably 18 to 70% by mass, based on the total mass of the monomer mixture constituting the polyol (ax). . When the content is adjusted within the above range, the glass transition temperature of the urethane prepolymer (A) can be appropriately adjusted, and excellent adhesion at low temperatures and excellent adhesion can be easily obtained, which is preferable.
（単量体（ａｘ’３））
　単量体（ａｘ’３）は、単量体（ａｘ’１）および単量体（ａｘ’２）以外のその他単量体であって、単量体（ａｘ’１）および単量体（ａｘ’２）と反応性を有するものであれば特に限定されない。例えば、単量体（ａｘ’３）として、脂肪族グリコール、脂肪族二塩基酸とグリコールとの反応生成物であるポリエステルポリオール、ポリエーテルポリオール、ポリブタジエンポリオール、ヒマシ油ポリオール等のポリオールを使用することができる。ポリオール（ａｘ）を構成する単量体混合物が、その他単量体（ａｘ’３）をさらに含む場合、ウレタンプレポリマー（Ａ）中の乳酸成分の結晶化度を低くすることがより容易となる。 (monomer (ax'3))
The monomer (ax'3) is a monomer other than the monomer (ax'1) and the monomer (ax'2), and the monomer (ax'1) and the monomer ( It is not particularly limited as long as it has reactivity with ax'2). For example, polyols such as aliphatic glycols, polyester polyols which are reaction products of aliphatic dibasic acids and glycols, polyether polyols, polybutadiene polyols, and castor oil polyols can be used as the monomer (ax'3). can be done. When the monomer mixture constituting the polyol (ax) further contains the other monomer (ax'3), it becomes easier to lower the crystallinity of the lactic acid component in the urethane prepolymer (A). .
　バイオマス度または生分解性原料の含有率を高めるためには、単量体（ａｘ’３）についても、バイオマス由来の原料または生分解性原料であることが好ましい。一実施形態では、単量体（ａｘ’３）として、特に、ポリエステルポリオールを好適に使用することができる。ポリエステルポリオールを使用した場合、単量体（ａｘ’１）および（ａｘ’２）との相溶性に優れ、共重合性が向上することによって、乳酸成分の結晶化度を低下させることができ、再剥離性を高めることが容易となる。 In order to increase the degree of biomass or the content of biodegradable raw materials, the monomer (ax'3) is also preferably a biomass-derived raw material or a biodegradable raw material. In one embodiment, a polyester polyol can be preferably used as the monomer (ax'3). When a polyester polyol is used, the compatibility with the monomers (ax'1) and (ax'2) is excellent, and the copolymerizability is improved, so that the crystallinity of the lactic acid component can be reduced. It becomes easy to improve removability.
　単量体（ａｘ’３）として使用できる脂肪族グリコールは、特に限定されない。例えば、エチレングリコール、１，２－プロピレングリコール、１，３－プロパンジオール、２－メチル－１，３－プロパンジオール、１，２－ブタンジオール、１，３－ブタンジオール、１，４－ブタンジオール、１，５－ペンタンジオール、１，６－ヘキサンジオール、３－メチル－１，５－ペンタンジオール、ネオペンチルグリコール、ジエチレングリコール、ジプロピレングリコール、２，２，４－トリメチル－１，５－ペンタンジオール、２－エチル－２－ブチルプロパンジオール、１，９－ノナンジオール、２－メチルオクタンジオール、１，１０－デカンジオール、１，４－シクロヘキサンジメタノール、１，２－シクロヘキサンジメタノール等が挙げられる。特に、バイオマス由来の原料から得られ、かつ生分解性原料であることから、１，２－プロピレングリコール、１，３－プロパンジオールが好ましい。上記脂肪族グリコールは、１種のみを使用しても、または２種以上を組み合わせて使用してもよい。 The aliphatic glycol that can be used as the monomer (ax'3) is not particularly limited. For example, ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol , 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 2,2,4-trimethyl-1,5-pentanediol , 2-ethyl-2-butylpropanediol, 1,9-nonanediol, 2-methyloctanediol, 1,10-decanediol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol and the like. . In particular, 1,2-propylene glycol and 1,3-propanediol are preferred because they are obtained from biomass-derived raw materials and are biodegradable raw materials. The above aliphatic glycols may be used alone or in combination of two or more.
　単量体（ａｘ’３）として使用できるポリエステルポリオールは、例えば、脂肪族二塩基酸と脂肪族グリコールとを縮合反応させて得られる。上記ポリエステルポリオールは、ＣＯＯＨ／ＯＨモル比が１．０未満となる、末端に水酸基を有する脂肪族ポリエステルポリオールを含むことが好ましい。このような脂肪族ポリエステルポリオールは、芳香族ポリエステルポリオールとは異なり、脂肪族ポリエステルポリオールを分解可能な酵素が自然界に多数存在するために好ましい。 A polyester polyol that can be used as the monomer (ax'3) is obtained, for example, by condensation reaction of an aliphatic dibasic acid and an aliphatic glycol. The above polyester polyol preferably contains an aliphatic polyester polyol having terminal hydroxyl groups and having a COOH/OH molar ratio of less than 1.0. Such aliphatic polyester polyols are preferable because, unlike aromatic polyester polyols, many enzymes capable of decomposing aliphatic polyester polyols exist in nature.
　上記脂肪族二塩基酸としては、アジピン酸、アゼライン酸、セバシン酸、１,４－シクロヘキサンジカルボン酸、４－メチル－１,２－シクロヘキサンジカルボン酸、ドデセニル無水コハク酸、フマル酸、コハク酸、ドデカン二酸、ヘキサヒドロ無水フタル酸、テトラヒドロ無水フタル酸、マレイン酸、無水マレイン酸、イタコン酸、シトラコン酸等の脂肪族および脂環族ジカルボン酸等が挙げられる。特に、バイオマス由来の原料から得られ、かつ生分解性原料であることから、セバシン酸、およびコハク酸が好ましい。上記脂肪族二塩基酸は、１種のみを使用しても、または２種以上を組み合わせて使用してもよい。一方、脂肪族グリコールは、先に説明したとおりである。 Examples of the aliphatic dibasic acids include adipic acid, azelaic acid, sebacic acid, 1,4-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, dodecenyl succinic anhydride, fumaric acid, succinic acid, and dodecane. Aliphatic and alicyclic dicarboxylic acids such as diacids, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, maleic acid, maleic anhydride, itaconic acid, citraconic acid, and the like. In particular, sebacic acid and succinic acid are preferred because they are obtained from biomass-derived raw materials and are biodegradable raw materials. The above aliphatic dibasic acids may be used alone or in combination of two or more. On the other hand, the aliphatic glycol is as explained above.
　本発明において所望とする粘着剤の特性、並びに粘着剤のバイオマス度および粘着剤における生分解性原料の比率を低下させない程度であれば、ポリエステルポリオールの原料として、芳香族二塩基酸を使用することができる。
　使用できる上記芳香族二塩基酸としては、特に限定されない。例えば、テレフタル酸、イソフタル酸、オルソフタル酸、１，５－ナフタレンジカルボン酸、２，６－ナフタレンジカルボン酸、４，４’－ジフェニルジカルボン酸、２，２’－ジフェニルジカルボン酸、４，４’－ジフェニルエーテルジカルボン酸等が挙げられる。これらは、１種のみを使用しても、または２種以上を組み合わせて使用してもよい。 An aromatic dibasic acid can be used as a raw material for a polyester polyol as long as it does not reduce the properties of the adhesive desired in the present invention, the degree of biomass of the adhesive, and the ratio of biodegradable raw materials in the adhesive. can be done.
The aromatic dibasic acid that can be used is not particularly limited. For example, terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-diphenyldicarboxylic acid, 2,2′-diphenyldicarboxylic acid, 4,4′- diphenyl ether dicarboxylic acid and the like. These may be used alone or in combination of two or more.
　ポリエステルポリオールにおいて、製造時に使用する脂肪族二塩基酸のアルキレン鎖の炭素数が小さいほど、ポリマーにおいてハードセグメント相が増加する。その結果、水分の浸入を効果的に防止でき、耐湿熱性を容易に向上できる傾向がある。また、同様の観点から、脂肪族グリコールのアルキレン鎖についても、炭素数が小さいことが好ましい。
　このような観点から、一実施形態において、上記ポリエステルポリオールは、例えば、アルキレン鎖の炭素数が２～１２の脂肪族二塩基酸と、炭素数２～１０の直鎖または分岐構造のアルキレン鎖を有する脂肪族グリコールとの重合物であってよい。 In the polyester polyol, the smaller the number of carbon atoms in the alkylene chain of the aliphatic dibasic acid used during production, the more hard segment phases there are in the polymer. As a result, there is a tendency that it is possible to effectively prevent the infiltration of moisture and easily improve the resistance to moist heat. From the same point of view, the number of carbon atoms in the alkylene chain of the aliphatic glycol is also preferably small.
From this point of view, in one embodiment, the polyester polyol comprises, for example, an aliphatic dibasic acid having an alkylene chain with 2 to 12 carbon atoms and an alkylene chain having a linear or branched structure with 2 to 10 carbon atoms. may be a polymer with an aliphatic glycol having
　上記脂肪族二塩基酸として、例えば、シュウ酸、マロン酸、コハク酸、グルタン酸、アジピン酸、ピメリン酸、スベリン酸、アゼライン酸、セバシン酸、ウンデカン二酸、およびドデカン二酸からなる群から選択される少なくとも１種が好ましい。なかでも、バイオマス由来の原料から得られ、かつ生分解性原料であること併せて、セバシン酸、およびコハク酸がより好ましく、コハク酸がさらに好ましい。 The aliphatic dibasic acid, for example, selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid is preferred. Among them, sebacic acid and succinic acid are more preferred because they are obtained from biomass-derived raw materials and are biodegradable raw materials, and succinic acid is even more preferred.
　また、上記脂肪族グリコールとして、例えば、エチレングリコール、１，２－プロピレングリコール、１，３－プロパンジオール、２－メチル－１，３－プロパンジオール、１，２－ブタンジオール、１，３－ブタンジオール、１，４－ブタンジオール、１，５－ペンタンジオール、１，６－ヘキサンジオール、１，７－ヘプタンジオール、１，８－オクタンジオール、１，９－ノナンジオール、１，１０－デカンジオール、ネオペンチルグリコール、３－メチル－１，５－ペンタンジオール、および２－メチルオクタンジオールからなる群から選択される少なくとも１種が好ましい。なかでも１，２－プロピレングリコール、および１，３－プロパンジオールがより好ましく、１，３－プロパンジオールがさらに好ましい。 Examples of aliphatic glycols include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, and 1,3-butane. Diol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol , neopentyl glycol, 3-methyl-1,5-pentanediol, and 2-methyloctanediol. Among them, 1,2-propylene glycol and 1,3-propanediol are more preferred, and 1,3-propanediol is even more preferred.
　一実施形態において、ポリエステルポリオールとして、市販品を使用することもできる。例えば、クラレ社製のクラレポリオールＰ－１０１０、およびＰ－２０１０が挙げられる。これらは、アジピン酸と、３－メチル－１，５－ペンタンジオールとの共重合体である。 In one embodiment, a commercially available product can also be used as the polyester polyol. Examples include Kuraray Polyol P-1010 and P-2010 manufactured by Kuraray Co., Ltd. These are copolymers of adipic acid and 3-methyl-1,5-pentanediol.
　単量体（ａｘ’３）として使用できるポリエーテルポリオールは、例えば、１分子中に２つの活性水素を有する活性水素含有化合物を開始剤として用い、１種以上のオキシラン化合物を付加重合させた反応物であってよい。
　上記オキシラン化合物としては、例えば、エチレンオキシド（ＥＯ）、プロピレンオキシド（ＰＯ）、およびブチレンオキシド（ＢＯ）等のアルキレンオキシド（ＡＯ）；テトラヒドロフラン（ＴＨＦ）等が挙げられる。
　一実施形態において、上記ポリエーテルポリオールとして、市販品を使用することもできる。例えば、三洋化成株式会社製の「サンニックスＰＰ－６００」（ポリオキシプロピレングリコール）を使用できる。 The polyether polyol that can be used as the monomer (ax'3) is, for example, a reaction in which an active hydrogen-containing compound having two active hydrogens in one molecule is used as an initiator and one or more oxirane compounds are subjected to addition polymerization. It can be a thing.
Examples of the oxirane compounds include alkylene oxides (AO) such as ethylene oxide (EO), propylene oxide (PO), and butylene oxide (BO); tetrahydrofuran (THF) and the like.
In one embodiment, a commercially available product can also be used as the polyether polyol. For example, "Sannics PP-600" (polyoxypropylene glycol) manufactured by Sanyo Kasei Co., Ltd. can be used.
　単量体（ａｘ’３）として使用できるポリブタジエン変性ポリオールは、例えば、２つ以上の水酸基末端を有し、１，２－ビニル部位、１，４－シス部位、１，４－トランス部位またはそれらが水素化された構造を有し、直鎖状若しくは分岐状のポリブタジエンであってよい。 Polybutadiene-modified polyols that can be used as the monomer (ax'3) have, for example, two or more hydroxyl group ends, 1,2-vinyl sites, 1,4-cis sites, 1,4-trans sites, or has a hydrogenated structure and may be linear or branched polybutadiene.
　単量体（ａｘ’３）として使用できるヒマシ油ポリオールは、例えば、ヒマシ油から誘導されるポリオール、またはヒマシ油を変性して得られるポリオールであってよい。 The castor oil polyol that can be used as the monomer (ax'3) may be, for example, a polyol derived from castor oil or a polyol obtained by modifying castor oil.
　上記ヒマシ油から誘導されるポリオールとしては、例えば、このグリセリンエステルのリシノレイン酸の一部をオレイン酸に置換したもの、ヒマシ油を鹸化して得られるリシノレイン酸を短分子ポリオールとエステル化したもの、これらとヒマシ油との混合物等、ヒマシ油由来の脂肪酸エステルポリオールであってよい。 Examples of polyols derived from castor oil include those obtained by substituting part of ricinoleic acid in glycerin esters with oleic acid, those obtained by esterifying ricinoleic acid obtained by saponifying castor oil with short-molecular-weight polyols, They may be fatty acid ester polyols derived from castor oil, such as mixtures of these with castor oil.
　上記ヒマシ油を変性して得られるポリオールとしては、例えば、植物油変性ポリオール、芳香族骨格（例えばビスフェノールＡ等）を有する変性ポリオール等が挙げられる。植物油変性ポリオールは、グリセリンエステルのリシノレイン酸の一部を、他の植物より得られる脂肪酸、例えば、大豆油、なたね油、オリーブ油等より得られるリノール酸、リノレン酸、オレイン酸等の高級脂肪酸に置換して得られるものである。 Examples of polyols obtained by modifying castor oil include vegetable oil-modified polyols and modified polyols having an aromatic skeleton (eg, bisphenol A, etc.). In the vegetable oil-modified polyol, part of the ricinoleic acid of the glycerin ester is replaced with fatty acids obtained from other plants, such as higher fatty acids such as linoleic acid, linolenic acid, and oleic acid obtained from soybean oil, rapeseed oil, and olive oil. It is obtained by
　ヒマシ油由来ポリオールの市販品としては、例えば、伊藤製油社製「ＵＲＩＣ　ＨＦ－１３００、Ｙ－４０３、ＨＦ－２００９」等が挙げられる。 Examples of commercially available castor oil-derived polyols include "URIC HF-1300, Y-403, HF-2009" manufactured by Ito Oil Co., Ltd., and the like.
　一実施形態において、上記単量体（ａｘ’３）の数平均分子量（Ｍｎ）は、５０～３，０００が好ましく、より好ましくは５００～２，０００である。一実施形態において、単量体（ａｘ’３）として使用するポリエステルポリオールのＭｎは、１５０～３,０００であることが好ましく、２００～２,０００であることがより好ましく、２００～８００であることがさらに好ましい。
　上記範囲内のＭｎを有する単量体（ａｘ’３）を使用した場合、単量体（ａｘ’３）に由来する成分の結晶化度が低いため、ウレタンプレポリマー（Ａ）中の乳酸成分の結晶化度を容易に低下できる傾向がある。その結果、再剥離性および耐湿熱性を容易に高めることができる。 In one embodiment, the number average molecular weight (Mn) of the monomer (ax'3) is preferably 50-3,000, more preferably 500-2,000. In one embodiment, the Mn of the polyester polyol used as the monomer (ax'3) is preferably 150 to 3,000, more preferably 200 to 2,000, and 200 to 800. is more preferred.
When the monomer (ax'3) having Mn within the above range is used, the crystallinity of the component derived from the monomer (ax'3) is low, so the lactic acid component in the urethane prepolymer (A) crystallinity tends to be easily reduced. As a result, removability and resistance to moist heat can be easily improved.
　一実施形態において、ポリオール（ａｘ）を構成する単量体混合物は、ウレタン化において十分な反応性を得る観点から、水酸基などの活性水素を片末端にのみ有する化合物、およびスルホン酸塩などの酸性基が塩を形成している化合物を含まないことが好ましい。したがって、一実施形態において、ポリオール（ａｘ）を構成する単量体混合物は、単量体（ａｘ’１）、単量体（ａｘ’２）、および単量体（ａｘ’３）のみからなることが好ましい。 In one embodiment, from the viewpoint of obtaining sufficient reactivity in urethanization, the monomer mixture constituting the polyol (ax) is a compound having an active hydrogen such as a hydroxyl group only at one end, and an acidic compound such as a sulfonate. It preferably does not contain compounds in which the groups form salts. Therefore, in one embodiment, the monomer mixture that constitutes the polyol (ax) consists only of the monomer (ax'1), the monomer (ax'2), and the monomer (ax'3) is preferred.
（ポリオール（ａｘ）の製造方法）
　ポリオール（ａｘ）の製造方法は、特に制限されない。ポリオール（ａｘ）は、塊状重合法および溶液重合法等の公知の重合方法によって製造することができる。製造方法の手順としては、例えば、以下が挙げられる。
　（手順１）単量体（ａｘ’１）として乳酸体、および単量体（ａｘ’２）として脂肪族ヒドロキシカルボン酸体を原料として使用し、これらを直接脱水重縮合する方法（例えば、ＵＳＰ ５，３１０，８６５号に示されている製造方法）。
　（手順２）単量体（ａｘ’１）としてラクチド体と、単量体（ａｘ’２）としてラクトン体を使用し、これらを溶融重合する開環重合法（例えば、米国特許２，７５８，９８７号に開示されている製造方法）。この（手順２）では、ラクチド体およびラクトン体は全て開環し、乳酸単位および脂肪族ヒドロキシカルボン酸単位を含むポリオールが得られる。
　（手順３）乳酸体および脂肪族ヒドロキシカルボン酸体を使用し、触媒の存在下、脱水重縮合反応を行うことによって重合体を製造する方法であり、少なくとも一部の工程で、固相重合を行う方法。
　また、上記（手順１）～（手順３）において、さらに脂肪族グリコールおよび脂肪族二塩基酸等のその他の単量体を共重合させて、ポリオール（ａｘ）を得てもよい。 (Method for producing polyol (ax))
A method for producing the polyol (ax) is not particularly limited. Polyol (ax) can be produced by known polymerization methods such as bulk polymerization and solution polymerization. The procedure of the manufacturing method includes, for example, the following.
(Procedure 1) A method of using a lactic acid body as a monomer (ax'1) and an aliphatic hydroxycarboxylic acid body as a monomer (ax'2) as raw materials and subjecting them to direct dehydration polycondensation (e.g., USP 5,310,865).
(Procedure 2) A ring-opening polymerization method in which a lactide body is used as a monomer (ax'1) and a lactone body is used as a monomer (ax'2), and these are melt-polymerized (e.g., US Pat. No. 2,758, 987). In this (Procedure 2), all the lactide and lactone bodies are ring-opened to obtain a polyol containing lactic acid units and aliphatic hydroxycarboxylic acid units.
(Procedure 3) A method of producing a polymer by carrying out a dehydration polycondensation reaction using a lactic acid compound and an aliphatic hydroxycarboxylic acid compound in the presence of a catalyst, wherein at least a part of the steps includes solid phase polymerization. How to do it.
Further, in the above (Procedure 1) to (Procedure 3), the polyol (ax) may be obtained by further copolymerizing other monomers such as aliphatic glycol and aliphatic dibasic acid.
　上記（手順１）～（手順３）において、乳酸体の単量体（ａｘ’１－１）と脂肪族ヒドロキシカルボン酸体（ａｘ’１－１）との共重合により得られるポリオール（ａｘ）は、乳酸体の単量体（ａｘ’１－１）および脂肪族ヒドロキシカルボン酸体（ａｘ’１－１）の共重合性が充分ではない場合がある。そのため得られるポリオール（ａｘ）において所望とするガラス転移温度、および乳酸由来の結晶性を達成できず、ウレタンプレポリマー（Ａ）において、所望とする特性を得ることが困難となる場合がある。 In the above (procedure 1) to (procedure 3), the polyol (ax) obtained by copolymerizing the lactic acid monomer (ax′1-1) and the aliphatic hydroxycarboxylic acid compound (ax′1-1) may not have sufficient copolymerizability of the lactic acid monomer (ax'1-1) and the aliphatic hydroxycarboxylic acid monomer (ax'1-1). Therefore, the desired glass transition temperature and lactic acid-derived crystallinity cannot be achieved in the resulting polyol (ax), and it may be difficult to obtain desired properties in the urethane prepolymer (A).
　したがって、上記（手順１）にしたがい、乳酸体の単量体（ａｘ’１－１）と脂肪族ヒドロキシカルボン酸体（ａｘ’１－１）を含む単量体混合物の共重合によってポリオール（ａｘ）を製造する方法よりも、上記（手順２）の方が好ましい。上記（手順２）のように、ポリオール（ａｘ）を製造するために、ラクチド体の単量体（ａｘ’１－２）およびラクトン体の単量体（ａｘ’２－２）を含む単量体混合物を用いた場合は、反応性の制御が容易となり、共重合性に優れ、高分子量化が容易となる点で好ましい。 Therefore, according to the above (procedure 1), a polyol (ax The above (procedure 2) is preferable to the method for producing ). Monomers containing a lactide monomer (ax′1-2) and a lactone monomer (ax′2-2) to produce a polyol (ax) as described above (Procedure 2) It is preferable to use a mixture of polymers because the reactivity can be easily controlled, the copolymerizability is excellent, and the molecular weight can be easily increased.
　ポリオール（ａｘ）の製造には、必要に応じて、触媒、および溶剤等を用いることができる。触媒は、後述する水酸基を有するウレタンプレポリマー（Ａ）の製造で例示する触媒と同じであってよい。 A catalyst, a solvent, etc. can be used for the production of the polyol (ax), if necessary. The catalyst may be the same catalyst as exemplified in the production of the urethane prepolymer (A) having hydroxyl groups, which will be described later.
　一実施形態において、単量体（ａｘ’３）の含有率は、ポリオール（ａｘ）を構成する単量体混合物の全質量を基準として、０．２質量％以上、９０質量％以下であってよい。一実施形態において、単量体（ａｘ’３）の含有率は、３～９０質量％であることが好ましく、１０～７０質量％がより好ましい。例えば、この実施形態では、単量体（ａｘ’３）として数平均分子量が１,０００～３,０００のポリエステルポリオールを好適に使用できる。 In one embodiment, the content of the monomer (ax'3) is 0.2% by mass or more and 90% by mass or less based on the total mass of the monomer mixture constituting the polyol (ax). good. In one embodiment, the content of the monomer (ax'3) is preferably 3-90% by mass, more preferably 10-70% by mass. For example, in this embodiment, a polyester polyol having a number average molecular weight of 1,000 to 3,000 can be suitably used as the monomer (ax'3).
　他の実施形態において、単量体（ａｘ’３）として数平均分子量が２００～８００のポリエステルポリオールを使用する場合、単量体（ａｘ’３）の含有率は、ポリオール（ａｘ）を構成する単量体混合物の全質量を基準として、０．２～１０質量％であることが好ましい。上記含有率は、０．７～９．５質量％であることがより好ましく、０．９～２．５質量％であることがさらに好ましい。 In another embodiment, when using a polyester polyol having a number average molecular weight of 200 to 800 as the monomer (ax'3), the content of the monomer (ax'3) constitutes the polyol (ax) It is preferably 0.2 to 10% by mass based on the total mass of the monomer mixture. The above content is more preferably 0.7 to 9.5% by mass, even more preferably 0.9 to 2.5% by mass.
　上記単量体（ａｘ’３）の含有率をそれぞれ上記範囲内に調整した場合、ウレタンプレポリマー（Ａ）のガラス転移温度を適切に調整でき、低温時の密着性に優れ、および優れた粘着力が得られる点で好ましい。 When the content of the monomer (ax'3) is adjusted within the above range, the glass transition temperature of the urethane prepolymer (A) can be adjusted appropriately, and the adhesion at low temperatures is excellent, and the adhesion is excellent. It is preferable in that power can be obtained.
［多官能ポリオール（ａｙ）］
　多官能ポリオール（ａｙ）は、水酸基を２つ以上有する化合物であり、好ましくは水酸基を３つ以上有する化合物である。多官能ポリオール（ａｙ）が水酸基を３つ以上有する化合物を含有することで、ウレタンプレポリマー（Ａ）に分岐骨格を生じさせ、凝集力を向上できるため、初期硬化性を付与することができる。ただし、多官能ポリオール（ａｙ）は、ポリオール（ａｘ）は除く。 [Polyfunctional polyol (ay)]
The polyfunctional polyol (ay) is a compound having two or more hydroxyl groups, preferably three or more hydroxyl groups. When the polyfunctional polyol (ay) contains a compound having 3 or more hydroxyl groups, the urethane prepolymer (A) can have a branched skeleton and can improve cohesive strength, thereby imparting initial curability. However, the polyfunctional polyol (ay) excludes the polyol (ax).
　多官能ポリオール（ａｙ）の数平均分子量は、１００～５，０００が好ましく、より好ましくは５００～３，０００であり、さらに好ましくは８００～２,０００である。数平均分子量がこの範囲内にあることで、イソシアネート硬化剤（Ｂ）との反応で充分な架橋密度が得られ、保持力が向上する。 The number average molecular weight of the polyfunctional polyol (ay) is preferably 100-5,000, more preferably 500-3,000, still more preferably 800-2,000. When the number average molecular weight is within this range, sufficient crosslink density can be obtained by reaction with the isocyanate curing agent (B), and the holding power is improved.
　多官能ポリオール（ａｙ）として、脂肪族ポリオール、ポリエステルポリオール、ポリエーテルポリオール、ポリブタジエンポリオール、およびヒマシ油ポリオール等を使用することができる。なかでも、脂肪族ポリエステルポリオールが好ましい。ポリエステルポリオールは、多価カルボン酸と脂肪族グリコールとの反応生成物であるか、脂肪族二塩基酸と脂肪族ポリオールとの反応生成物である、水酸基を３つ以上有する脂肪族ポリエステルポリオールであることがより好ましい。脂肪族ポリエステルポリオールは、これらを分解可能な酵素が自然界に多数存在することから特に好ましい。 As polyfunctional polyols (ay), aliphatic polyols, polyester polyols, polyether polyols, polybutadiene polyols, castor oil polyols, and the like can be used. Among them, aliphatic polyester polyols are preferred. The polyester polyol is an aliphatic polyester polyol having three or more hydroxyl groups, which is a reaction product of a polycarboxylic acid and an aliphatic glycol, or a reaction product of an aliphatic dibasic acid and an aliphatic polyol. is more preferable. Aliphatic polyester polyols are particularly preferred because there are many enzymes in nature that can decompose them.
　上記多価カルボン酸としては、例えば、トリメリット酸、ピロメリット酸、ベンゾフェノンテトラカルボン酸、ビフェニルテトラカルボン酸、エチレングリコールビス（アンヒドロトリメリテート）、グルセロールトリス（アンヒドロトリメート）等が挙げられる。一方、上記脂肪族グリコールとしては、先に単量体（ａｘ’３）に関する説明で記載した化合物と同様であってよい。 Examples of the polyvalent carboxylic acid include trimellitic acid, pyromellitic acid, benzophenonetetracarboxylic acid, biphenyltetracarboxylic acid, ethylene glycol bis(anhydrotrimellitate), glycerol tris(anhydrotrimate), and the like. is mentioned. On the other hand, the above-mentioned aliphatic glycol may be the same as the compounds described above in the description of the monomer (ax'3).
　上記脂肪族ポリオールとしては、例えば、グリセリン、トリメチロールプロパン、ペンタエリスリトールなどが挙げられる。一方、脂肪族二塩基酸は、先に単量体（ａｘ’３）に関する説明で記載した化合物と同様であってよい。 Examples of the aliphatic polyols include glycerin, trimethylolpropane, and pentaerythritol. On the other hand, the aliphatic dibasic acid may be the same as the compounds described above in the description of the monomer (ax'3).
　一実施形態において、多官能ポリオール（ａｙ）として、市販品を使用することもできる。例えば、三洋化成工業社製のサンニックスＰＰ－６００が挙げられる。これは、グリセリンとプロピレンオキシド（ＰＯ）とエチレンオキシド（ＥＯ）との共重合体である、ポリオキシプロピレングリコールである。
　また、例えば、日本曹達社製のＮＩＳＳＯ－ＰＢＧＩ－３０００が挙げられる。これは、グリセリンとプロピレンオキシド（ＰＯ）とエチレンオキシド（ＥＯ）との共重合体である、ポリオキシプロピレングリコールである。
　また、例えば、クラレ社製のクラレポリオールＦ－１０１０が挙げられる。これは、３－メチル－１，５－ペンタンジオールと、アジピン酸と、トリメチロールプロパンとの共重合体である、３分岐構造のポリエステルポリオールである。
　さらに、例えば、ダイセル社製のＰｌａｃｃｅｌ４１０が挙げられる。これは、４官能水酸基含有化合物とε－カプロラクトンとの重合体である、４分岐構造のポリエステルポリオールである。 In one embodiment, a commercially available product can also be used as the polyfunctional polyol (ay). For example, Sannics PP-600 manufactured by Sanyo Chemical Industries, Ltd. can be mentioned. This is polyoxypropylene glycol, a copolymer of glycerin, propylene oxide (PO) and ethylene oxide (EO).
Also, for example, NISSO-PBGI-3000 manufactured by Nippon Soda Co., Ltd. can be used. This is polyoxypropylene glycol, a copolymer of glycerin, propylene oxide (PO) and ethylene oxide (EO).
Also, for example, Kuraray Polyol F-1010 manufactured by Kuraray Co., Ltd. can be used. This is a tri-branched polyester polyol which is a copolymer of 3-methyl-1,5-pentanediol, adipic acid and trimethylolpropane.
Furthermore, for example, Placel 410 manufactured by Daicel Corporation can be used. This is a tetra-branched polyester polyol which is a polymer of a tetrafunctional hydroxyl group-containing compound and ε-caprolactone.
　多官能ポリオール（ａｙ）の含有率は、ウレタンプレポリマー（Ａ）の全質量を基準として、０．５～２５質量％が好ましく、より好ましくは、５～１５質量％である。０．５質量％以上であると、分岐骨格が充分に形成され、凝集力に優れ、初期硬化性がより向上する。また、２５質量％以下であると、ウレタンプレポリマー（Ａ）の製造時に、ゲル化物または凝集物の発生を抑制できるため好ましい。 The content of the polyfunctional polyol (ay) is preferably 0.5-25% by mass, more preferably 5-15% by mass, based on the total mass of the urethane prepolymer (A). When it is 0.5% by mass or more, the branched skeleton is sufficiently formed, the cohesive force is excellent, and the initial curability is further improved. Further, when the content is 25% by mass or less, it is possible to suppress the generation of gelled substances or aggregates during the production of the urethane prepolymer (A), which is preferable.
［ポリイソシアネート（ａｚ）］
　ポリイソシアネート（ａｚ）としては公知の化合物を使用できる。例えば、芳香族ポリイソシアネート、脂肪族ポリイソシアネート、および脂環族ポリイソシアネート等が挙げられる。 [Polyisocyanate (az)]
A known compound can be used as the polyisocyanate (az). Examples include aromatic polyisocyanates, aliphatic polyisocyanates, and alicyclic polyisocyanates.
　芳香族ポリイソシアネートとしては、例えば、１，３－フェニレンジイソシアネート、４，４’－ジフェニルジイソシアネート、１，４－フェニレンジイソシアネート、４，４’－ジフェニルメタンジイソシアネート、２，４－トリレンジイソシアネート、２，６－トリレンジイソシアネート、４，４’－トルイジンジイソシアネート、２，４，６－トリイソシアネートトルエン、１，３，５－トリイソシアネートベンゼン、ジアニシジンジイソシアネート、４，４’－ジフェニルエーテルジイソシアネート、および４，４’，４”－トリフェニルメタントリイソシアネート、ω，ω’－ジイソシアネート－１，３－ジメチルベンゼン、ω，ω’－ジイソシアネート－１，４－ジメチルベンゼン、ω，ω’－ジイソシアネート－１，４－ジエチルベンゼン、１，４－テトラメチルキシリレンジイソシアネート、および１，３－テトラメチルキシリレンジイソシアネート等が挙げられる。 Examples of aromatic polyisocyanates include 1,3-phenylene diisocyanate, 4,4'-diphenyldiisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6 - tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanatotoluene, 1,3,5-triisocyanatobenzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, and 4,4' ,4″-triphenylmethane triisocyanate, ω,ω′-diisocyanate-1,3-dimethylbenzene, ω,ω′-diisocyanate-1,4-dimethylbenzene, ω,ω′-diisocyanate-1,4-diethylbenzene , 1,4-tetramethylxylylene diisocyanate, and 1,3-tetramethylxylylene diisocyanate.
　脂肪族ポリイソシアネートとしては、例えば、トリメチレンジイソシアネート、テトラメチレンジイソシアネート、ヘキサメチレンジイソシアネート（ＨＤＩ）、ペンタメチレンジイソシアネート、１，２－プロピレンジイソシアネート、２，３－ブチレンジイソシアネート、１，３－ブチレンジイソシアネート、ドデカメチレンジイソシアネート、および２，４，４－トリメチルヘキサメチレンジイソシアネート等が挙げられる。 Examples of aliphatic polyisocyanates include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodeca methylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and the like.
　脂環族ポリイソシアネートとしては、例えば、イソホロンジイソシアネート（ＩＰＤＩ）、１，３－シクロペンタンジイソシアネート、１，３－シクロヘキサンジイソシアネート、１，４－シクロヘキサンジイソシアネート、メチル－２，４－シクロヘキサンジイソシアネート、メチル－２，６－シクロヘキサンジイソシアネート、４，４’－メチレンビス（シクロヘキシルイソシアネート）、および１，４－ビス（イソシアネートメチル）シクロヘキサン等が挙げられる。 Examples of alicyclic polyisocyanates include isophorone diisocyanate (IPDI), 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2,4-cyclohexane diisocyanate, methyl-2 ,6-cyclohexanediisocyanate, 4,4′-methylenebis(cyclohexylisocyanate), and 1,4-bis(isocyanatomethyl)cyclohexane.
　その他、ポリイソシアネートとして、例えば、上記ポリイソシアネートのトリメチロールプロパンアダクト体、ビウレット体、アロファネート体、および３量体（この３量体はイソシアヌレート環を含む。）等が挙げられる。 In addition, examples of polyisocyanates include trimethylolpropane adducts, biurets, allophanates, and trimers of the above polyisocyanates (this trimer contains an isocyanurate ring).
　ポリイソシアネート（ａｚ）としては、４，４’－ジフェニルメタンジイソシアネート、ヘキサメチレンジイソシアネート（ＨＤＩ）、および、イソホロンジイソシアネート（ＩＰＤＩ）等が好ましい。これらの少なくとも１種を使用した場合、適度なウレタン結合による凝集力を付与することができ、充分な粘着特性が容易に得られる。 As the polyisocyanate (az), 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and the like are preferable. When at least one of these is used, a suitable cohesive force can be imparted by urethane bonds, and sufficient adhesive properties can be easily obtained.
　ウレタンプレポリマー（Ａ）の製造において、ポリイソシアネート（ａｚ）のイソシアネート基（イソシアナト基）に対する、ポリオール（ａｘ）および多官能ポリオール（ａｙ）を合計した水酸基のモル比（ＮＣＯ／ＯＨの値）は、０．１以上であってよく、好ましくは０．２～０．９であり、より好ましくは０．３～０．８５であり、さらに好ましくは０．４～０．８５である。上記モル比（ＮＣＯ／ＯＨの値）が上記範囲内となるように、原料の配合比を調整することが好ましい。
　ＮＣＯ／ＯＨの値が１に近づくと、ウレタンプレポリマー（Ａ）の製造時にゲル化物または凝集物が生じやすくなる場合がある。そのため、ＮＣＯ／ＯＨの値を０．９以下に調整することによって、ウレタンプレポリマー（Ａ）の製造時のゲル化を効果的に抑制することができる。ＮＣＯ／ＯＨの値を０．１以上に調整した場合、得られるウレタンプレポリマー（Ａ）の分子量が高くなり、充分な粘着特性が得られる点で好ましい。 In the production of the urethane prepolymer (A), the molar ratio (NCO/OH value) of the total hydroxyl group of the polyol (ax) and the polyfunctional polyol (ay) to the isocyanate group (isocyanato group) of the polyisocyanate (az) is , may be 0.1 or more, preferably 0.2 to 0.9, more preferably 0.3 to 0.85, still more preferably 0.4 to 0.85. It is preferable to adjust the mixing ratio of the raw materials so that the molar ratio (NCO/OH value) is within the above range.
When the NCO/OH value approaches 1, gelled products or aggregates may easily occur during production of the urethane prepolymer (A). Therefore, by adjusting the NCO/OH value to 0.9 or less, it is possible to effectively suppress gelation during the production of the urethane prepolymer (A). When the value of NCO/OH is adjusted to 0.1 or more, the obtained urethane prepolymer (A) has a high molecular weight, which is preferable in that sufficient adhesive properties can be obtained.
　ポリイソシアネート（ａｚ）の含有率は、高い粘着力を得るために、ウレタンプレポリマー（Ａ）の全質量を基準として、０．３以上であってよく、０．５～３０質量％が好ましく、０．６～２０質量％がより好ましく、１．０～２０質量％がさらに好ましい。 The content of the polyisocyanate (az) may be 0.3 or more, preferably 0.5 to 30% by mass, based on the total mass of the urethane prepolymer (A), in order to obtain high adhesive strength. 0.6 to 20% by mass is more preferable, and 1.0 to 20% by mass is even more preferable.
［触媒］
　ポリオール（ａｘ）、または水酸基を有するウレタンプレポリマー（Ａ）の製造において、必要に応じて、１種以上の触媒を用いることができる。触媒としては公知の化合物を使用できる。使用できる触媒として、例えば、３級アミン系化合物および有機金属系化合物等が挙げられる。 [catalyst]
In the production of the polyol (ax) or the hydroxyl group-containing urethane prepolymer (A), one or more catalysts can be used as necessary. A known compound can be used as the catalyst. Usable catalysts include, for example, tertiary amine compounds and organometallic compounds.
　３級アミン系化合物としては、例えば、トリエチルアミン、トリエチレンジアミン、および１，８－ジアザビシクロ（５，４，０）－ウンデセン－７（ＤＢＵ）等が挙げられる。 Examples of tertiary amine compounds include triethylamine, triethylenediamine, and 1,8-diazabicyclo(5,4,0)-undecene-7 (DBU).
　有機金属系化合物としては、例えば、錫系化合物および非錫系化合物等が挙げられる。
　錫系化合物としては、例えば、ジブチル錫ジクロライド、ジブチル錫オキシド、ジブチル錫ジブロマイド、ジブチル錫ジマレエート、ジブチル錫ジラウレート（ＤＢＴＤＬ）、ジブチル錫ジアセテート、ジブチル錫スルファイド、ジオクチル錫ジラウレート、トリブチル錫スルファイド、トリブチル錫オキシド、トリブチル錫アセテート、トリエチル錫エトキサイド、トリブチル錫エトキサイド、ジオクチル錫オキシド、トリブチル錫クロライド、トリブチル錫トリクロロアセテート、２－エチルオクチル酸錫、および２－エチルヘキサン酸錫等が挙げられる。 Examples of organometallic compounds include tin-based compounds and non-tin-based compounds.
Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, dioctyltin dilaurate, tributyltin sulfide, and tributyltin. Tin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, tin 2-ethyloctylate, and tin 2-ethylhexanoate.
　非錫系化合物としては、例えば、ジブチルチタニウムジクロライド、テトラブチルチタネート、およびブトキシチタニウムトリクロライド等のチタン系；オレイン酸鉛、２－エチルヘキサン酸鉛、安息香酸鉛、およびナフテン酸鉛等の鉛系；２－エチルヘキサン酸鉄および鉄アセチルアセトネート等の鉄系；安息香酸コバルトおよび２－エチルヘキサン酸コバルト等のコバルト系；ナフテン酸亜鉛および２－エチルヘキサン酸亜鉛等の亜鉛系；ナフテン酸ジルコニウム等のジルコニウム系が挙げられる。
　触媒の種類および添加量は、反応が良好に進む範囲で適宜調整することができる。 Examples of non-tin compounds include titanium compounds such as dibutyl titanium dichloride, tetrabutyl titanate, and butoxy titanium trichloride; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate; iron-based such as iron 2-ethylhexanoate and iron acetylacetonate; cobalt-based such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc-based such as zinc naphthenate and zinc 2-ethylhexanoate; zirconium naphthenate Zirconium-based such as.
The type and amount of catalyst to be added can be appropriately adjusted within a range in which the reaction proceeds well.
　触媒の使用量は、ポリオール（ａｘ）またはウレタンプレポリマー（Ａ）の構成成分の合計１００質量部に対して、０．０００１～１．０質量部であることが好ましい。上記使用量は、０．００１～０．５質量部であることがより好ましく、０．００５～０．１質量部であることがさらに好ましく、０．０１～０．１質量部であることがさらにより好ましい。 The amount of the catalyst used is preferably 0.0001 to 1.0 parts by mass with respect to the total 100 parts by mass of the constituent components of the polyol (ax) or urethane prepolymer (A). The amount used is more preferably 0.001 to 0.5 parts by mass, more preferably 0.005 to 0.1 parts by mass, and 0.01 to 0.1 parts by mass. Even more preferred.
　ポリオール（ａｘ）またはウレタンプレポリマー（Ａ）の製造時に触媒を用いる場合、上記触媒を不活性化させてもよい。特に、水酸基を有するウレタンプレポリマー（Ａ）の製造では、不活性化させた触媒を使用することが好ましい。反応停止剤として、例えば、アセチルアセトン、またはリン酸化合物等を配合することができる。反応停止剤は、1種のみを使用しても、または２種以上を組合せて使用してもよい。 When a catalyst is used in the production of polyol (ax) or urethane prepolymer (A), the catalyst may be deactivated. In particular, it is preferable to use an inactivated catalyst in the production of the urethane prepolymer (A) having hydroxyl groups. As a reaction terminator, for example, acetylacetone, a phosphoric acid compound, or the like can be blended. The reaction terminator may be used alone or in combination of two or more.
［溶剤］
　ポリオール（ａｘ）、ウレタンプレポリマー（Ａ）の製造には、必要に応じて、１種以上の溶剤を用いることができる。使用できる溶剤として、例えば、アセトン、およびメチルエチルケトン等のケトン系溶剤、酢酸エチル等のエステル系溶剤、トルエン、およびキシレン等の炭化水素系溶剤、並びにジフェニルエーテル等のエーテル系溶剤等が挙げられる。特に、ウレタンプレポリマー（Ａ）の製造では、上記溶剤のなかでも、溶解性および溶剤の沸点等の点から、エステル系溶剤、および炭化水素系溶剤等が好ましい。一実施形態において、粘着剤組成物は、ポリオール（ａｘ）、ウレタンプレポリマー（Ａ）の製造時に使用した溶剤を含んでいてもよい。 [solvent]
If necessary, one or more solvents can be used in the production of the polyol (ax) and the urethane prepolymer (A). Usable solvents include, for example, ketone solvents such as acetone and methyl ethyl ketone, ester solvents such as ethyl acetate, hydrocarbon solvents such as toluene and xylene, and ether solvents such as diphenyl ether. In particular, in the production of the urethane prepolymer (A), among the above solvents, ester solvents, hydrocarbon solvents, and the like are preferable from the viewpoints of solubility and the boiling point of the solvent. In one embodiment, the pressure-sensitive adhesive composition may contain the polyol (ax) and the solvent used during the production of the urethane prepolymer (A).
［ウレタンプレポリマー（Ａ）の製造方法］
　ウレタンプレポリマー（Ａ）の製造方法は、特に制限されない。ウレタンプレポリマー（Ａ）は、例えば、塊状重合法および溶液重合法等の公知の重合方法によって製造することができる。製造方法の手順としては、例えば、以下が挙げられる。
　（手順１）１種以上のポリイソシアネート（ａｚ）、１種以上のポリオール（ａｘ）、多官能ポリオール（ａｙ）、必要に応じて１種以上の触媒、および必要に応じて１種以上の溶剤を使用し、これらを一括してフラスコに仕込む手順。
　（手順２）１種以上のポリオール（ａｘ）、多官能ポリオール（ａｙ）、必要に応じて１種以上の触媒、および必要に応じて１種以上の溶剤をフラスコに仕込み、これに１種以上のポリイソシアネート（ａｚ）を滴下添加する手順。 [Method for producing urethane prepolymer (A)]
A method for producing the urethane prepolymer (A) is not particularly limited. The urethane prepolymer (A) can be produced, for example, by known polymerization methods such as bulk polymerization and solution polymerization. The procedure of the manufacturing method includes, for example, the following.
(Procedure 1) one or more polyisocyanates (az), one or more polyols (ax), multifunctional polyols (ay), optionally one or more catalysts, and optionally one or more solvents and put them all together in a flask.
(Procedure 2) One or more polyols (ax), polyfunctional polyols (ay), optionally one or more catalysts, and optionally one or more solvents are charged into a flask, into which one or more dropwise addition of polyisocyanate (az) of.
　これらの手順のなかでも、上記（手順２）が好ましい。上記（手順２）では、ポリオール（ａｘ）、多官能ポリオール（ａｙ）およびポリイソシアネート（ａｚ）の局所的な反応性の低下を抑制し、および過度な高分子量成分の反応を抑制することによって、分子量分散度を広くすることができる。 Among these procedures, the above (procedure 2) is preferable. In the above (procedure 2), by suppressing the local decrease in reactivity of the polyol (ax), the polyfunctional polyol (ay) and the polyisocyanate (az) and suppressing excessive reaction of the high molecular weight component, The molecular weight dispersity can be broadened.
　反応温度は、触媒を使用する場合、１００℃未満が好ましく、８５～９５℃がより好ましい。反応温度を１００℃未満に調整した場合、ウレタン反応以外の副反応を抑制できるため、所望とするポリマーを容易に得ることができる。反応温度は、触媒を使用しない場合、１００℃以上が好ましく、１１０℃以上がより好ましい。 When using a catalyst, the reaction temperature is preferably less than 100°C, more preferably 85 to 95°C. When the reaction temperature is adjusted to less than 100° C., side reactions other than the urethane reaction can be suppressed, making it possible to easily obtain the desired polymer. The reaction temperature is preferably 100° C. or higher, more preferably 110° C. or higher, when no catalyst is used.
＜硬化剤＞
　本発明の一実施形態である粘着剤組成物は、さらに硬化剤を含んでもよい。硬化剤の使用は、ポリマーの硬化性を向上できる点で好ましい。
　硬化剤として、例えば、イソシアネート硬化剤（Ｂ）、エポキシ硬化剤、メラミン硬化剤、カルボジイミド硬化剤、オキサゾリン硬化剤、およびアジリジン硬化剤等を使用することができる。
　一実施形態において、粘着剤組成物は、イソシアネート硬化剤（Ｂ）を含むことが好ましい。イソシアネート硬化剤（Ｂ）の使用は、初期硬化性を更に向上させることができ、特に、充分な保持力が容易に得られる点で好ましい。 <Curing agent>
The adhesive composition that is one embodiment of the present invention may further contain a curing agent. The use of a curing agent is preferred in terms of improving the curability of the polymer.
Examples of curing agents that can be used include isocyanate curing agents (B), epoxy curing agents, melamine curing agents, carbodiimide curing agents, oxazoline curing agents, and aziridine curing agents.
In one embodiment, the pressure-sensitive adhesive composition preferably contains an isocyanate curing agent (B). The use of the isocyanate curing agent (B) is preferable in that the initial curability can be further improved, and sufficient holding power can be easily obtained.
［イソシアネート硬化剤（Ｂ）］
　イソシアネート硬化剤（Ｂ）としては、公知の化合物を使用できる。例えば、水酸基を有するウレタンプレポリマー（Ａ）の原料であるポリイソシアネート（ａｚ）として例示した化合物であってよい。具体的には、芳香族ポリイソシアネート、脂肪族ポリイソシアネート、芳香脂肪族ポリイソシアネート、脂環族ポリイソシアネート、および、これらのトリメチロールプロパンアダクト体／ビウレット体／３量体を用いることができる。 [Isocyanate curing agent (B)]
A known compound can be used as the isocyanate curing agent (B). For example, it may be a compound exemplified as polyisocyanate (az), which is a raw material for urethane prepolymer (A) having a hydroxyl group. Specifically, aromatic polyisocyanates, aliphatic polyisocyanates, araliphatic polyisocyanates, alicyclic polyisocyanates, and trimethylolpropane adducts/biurets/trimers thereof can be used.
　一実施形態において、粘着剤組成物は、必要に応じて、さらにイソシアネート硬化剤（Ｂ）を含んでもよい。イソシアネート硬化剤（Ｂ）の含有量は、ウレタンプレポリマー（Ａ）１００質量部に対して、２５質量部以下が好ましく、１．０～１５質量部がより好ましく、１．５～１５質量部がさらに好ましい。イソシアネート硬化剤（Ｂ）の含有量を上記範囲内に調整した場合、より優れた初期硬化性を容易に得ることができる。 In one embodiment, the adhesive composition may further contain an isocyanate curing agent (B) as necessary. The content of the isocyanate curing agent (B) is preferably 25 parts by mass or less, more preferably 1.0 to 15 parts by mass, and more preferably 1.5 to 15 parts by mass with respect to 100 parts by mass of the urethane prepolymer (A). More preferred. When the content of the isocyanate curing agent (B) is adjusted within the above range, better initial curability can be easily obtained.
＜粘着付与樹脂＞
　一実施形態において、粘着剤組成物は、さらに粘着付与樹脂を含んでもよい。粘着付与樹脂の使用は、より粘着特性を向上させることができる点で好ましい。
　粘着付与樹脂として、例えば、ロジン系樹脂、ポリテルペン樹脂、脂肪族炭化水素樹脂、脂肪族石油樹脂、芳香族石油樹脂、アルキルフェノールホルムアルデヒド樹脂（油性フェノール樹脂）等を使用することができる。
　また、粘着付与樹脂は、バイオマス由来の原料から得られた樹脂であることが好ましい。このような点から、粘着付与樹脂として、例えば、ロジン系樹脂、またはポリテルペン樹脂等の樹脂が好ましい。 <Tackifying resin>
In one embodiment, the adhesive composition may further comprise a tackifying resin. The use of a tackifying resin is preferable because it can further improve the adhesive properties.
As the tackifying resin, for example, rosin-based resins, polyterpene resins, aliphatic hydrocarbon resins, aliphatic petroleum resins, aromatic petroleum resins, alkylphenol formaldehyde resins (oily phenolic resins) and the like can be used.
Moreover, the tackifying resin is preferably a resin obtained from a biomass-derived raw material. From this point of view, resins such as rosin-based resins and polyterpene resins are preferable as the tackifying resin.
　粘着付与樹脂の含有量は、ウレタンプレポリマー（Ａ）１００質量部に対して、２～５０質量部が好ましく、５～４０質量部がより好ましい。
　上記含有量を２質量部以上に調整した場合、粘着付与樹脂の添加による効果によって、所望とする粘着特性を容易に得ることができる。また、上記含有量を５０質量部以下に調整した場合、ウレタンプレポリマー（Ａ）等のポリマー成分との良好な相溶性が得られる点で好ましい。そのため、塗液外観または塗膜外観において、白濁化または白化する問題の発生を抑制することができる。 The content of the tackifying resin is preferably 2 to 50 parts by mass, more preferably 5 to 40 parts by mass, based on 100 parts by mass of the urethane prepolymer (A).
When the above content is adjusted to 2 parts by mass or more, the desired adhesive property can be easily obtained due to the effect of the addition of the tackifying resin. Further, when the content is adjusted to 50 parts by mass or less, it is preferable in terms of obtaining good compatibility with the polymer component such as the urethane prepolymer (A). Therefore, it is possible to suppress the occurrence of the problem of cloudiness or whitening in the coating liquid appearance or coating film appearance.
＜その他の成分＞
　一実施形態において、粘着剤組成物は、粘着剤としての特性と、生分解性を損なわない程度であれば、上記成分以外に一般的な添加剤をさらに含んでもよい。使用できる添加剤として、例えば、紫外線吸収剤、光安定剤、レベリング剤、帯電防止剤、剥離調整剤、充填剤、着色剤、老化防止剤、可塑剤、および界面活性剤等が挙げられる。 <Other ingredients>
In one embodiment, the pressure-sensitive adhesive composition may further contain general additives in addition to the above components as long as the pressure-sensitive adhesive properties and biodegradability are not impaired. Additives that can be used include, for example, ultraviolet absorbers, light stabilizers, leveling agents, antistatic agents, release modifiers, fillers, colorants, antioxidants, plasticizers, surfactants, and the like.
＜２＞粘着シート
　本発明の他の実施形態は、粘着シートに関する。粘着シートは、基材の少なくとも一方の面に、上記実施形態の粘着剤組成物から形成されてなる粘着剤層を有する。すなわち、粘着シートは、基材と、基材の少なくとも一方の面に設けられた粘着剤層とを有し、粘着剤層は上記実施形態の粘着剤組成物の硬化物から構成される。一実施形態において、基材と接していない粘着剤層の他方の面には、異物の付着を防止するために剥離シートを設けてよい。通常、粘着剤層は、使用する直前まで剥離シートによって保護される。 <2> Adhesive Sheet Another embodiment of the present invention relates to an adhesive sheet. The pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the above embodiment on at least one surface of a substrate. That is, the adhesive sheet has a substrate and an adhesive layer provided on at least one surface of the substrate, and the adhesive layer is composed of a cured product of the adhesive composition of the above embodiment. In one embodiment, a release sheet may be provided on the other side of the pressure-sensitive adhesive layer that is not in contact with the substrate in order to prevent adhesion of foreign matter. The pressure-sensitive adhesive layer is usually protected by a release sheet until just before use.
　基材は、柔軟なシートおよび板材であればよく、制限なく使用できる。基材は、プラスチック、紙、および金属箔、ならびにこれら１種以上の材料から構成される積層体等が挙げられる。
　粘着剤層と接する基材の表面は、密着性向上のため、簡便な接着処理を適用してもよい。例えば、コロナ放電処理等の乾式処理、アンカーコート剤塗布等の湿式処理を適用することができる。 Any flexible sheet or plate material can be used as the base material without limitation. Base materials include plastics, papers, metal foils, laminates made of one or more of these materials, and the like.
A simple adhesion treatment may be applied to the surface of the base material in contact with the pressure-sensitive adhesive layer in order to improve adhesion. For example, dry treatment such as corona discharge treatment and wet treatment such as application of an anchor coating agent can be applied.
　一実施形態において、基材を構成するプラスチック材料としては、例えば、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）等のエステル系樹脂；ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）およびシクロオレフィンポリマー（ＣＯＰ）等のオレフィン系樹脂；ポリ塩化ビニル等のビニル系樹脂；ナイロン６６等のアミド系樹脂；ウレタン系樹脂（発泡体を含む）等が挙げられる。 In one embodiment, the plastic material constituting the base material includes, for example, ester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyethylene (PE), polypropylene (PP) and cycloolefin polymer (COP); ); vinyl resins such as polyvinyl chloride; amide resins such as nylon 66; urethane resins (including foams).
　基材の厚みは、一般的に１０～３００μｍであってよい。基材としてポリウレタンシート（発泡体を含む）を使用する場合、基材（シート）の厚みは、一般的に２０～５０，０００μｍであってよい。基材として紙を使用することもできる。例えば、普通紙、コート紙、およびアート紙等が挙げられる。また、基材として金属箔を使用することもできる。金属箔としては、例えば、アルミニウム箔、および銅箔等が挙げられる。 The thickness of the substrate may generally be 10-300 μm. When a polyurethane sheet (including foam) is used as the substrate, the thickness of the substrate (sheet) may generally be from 20 to 50,000 μm. Paper can also be used as a substrate. Examples include plain paper, coated paper, and art paper. Metal foil can also be used as the substrate. Examples of metal foil include aluminum foil and copper foil.
　剥離シートは、公知の構成を有する剥離シートであってよい。例えば、プラスチックまたは紙等のシート状の材料表面に、シリコーン系剥離剤等の公知の剥離処理を適用した剥離シートを使用できる。 The release sheet may be a release sheet having a known configuration. For example, a release sheet obtained by applying a known release treatment such as a silicone release agent to the surface of a sheet-like material such as plastic or paper can be used.
　一実施形態において、基材は、生分解性原料から構成される生分解性基材であることが好ましい。生分解性基材は、例えば、紙基材、布基材、および生分解性樹脂基材からなる群から選択される１種又は２種以上の組合せであってよい。
　紙基材の一例として、パルプを成形した基材、またはパルプにマニラ麻などを混ぜて強度を改善した基材などが挙げられる。
　布基材の一例として、綿、レーヨン、アセテートなどの繊維から形成される基材が挙げられる。
　生分解性樹脂基材とは、植物、動物、および微生物といったバイオマスを用いて合成した樹脂、または石油由来であるが生分解性を有する樹脂から形成される基材を意味する。一実施形態において、生分解性樹脂基材を構成する生分解性樹脂としては、例えば、多糖類、ポリビニルアルコール樹脂、および生分解性ポリエステル樹脂が挙げられる。これらの１種又は２種以上を組合せて使用して生分解性樹脂基材を構成することができる。 In one embodiment, the substrate is preferably a biodegradable substrate composed of biodegradable raw materials. The biodegradable substrate may be, for example, one or a combination of two or more selected from the group consisting of paper substrates, cloth substrates, and biodegradable resin substrates.
Examples of paper substrates include substrates obtained by molding pulp, and substrates obtained by mixing pulp with manila hemp or the like to improve strength.
Examples of fabric substrates include substrates formed from fibers such as cotton, rayon, and acetate.
A biodegradable resin base material means a base material formed from a resin synthesized using biomass such as plants, animals, and microorganisms, or a petroleum-derived but biodegradable resin. In one embodiment, biodegradable resins that make up the biodegradable resin substrate include, for example, polysaccharides, polyvinyl alcohol resins, and biodegradable polyester resins. A biodegradable resin substrate can be constructed by using one or more of these in combination.
　多糖類の具体例として、セルロース、および酢酸セルロース樹脂が挙げられる。
　生分解性ポリエステル樹脂の具体例として、ポリヒドロキシアルカン樹脂、ポリヒドロキシアルカノエート樹脂、ポリエチレンテレフタレートサクシネート樹脂、ポリブチレンアジペートテレフタレート樹脂、ポリブチレンサクシネート樹脂、およびポリブチレンサクシネートアジペート樹脂といったポリヒドロキシアルカノエート樹脂、ポリカプロラクトン樹脂、ポリ乳酸樹脂、並びにポリ（ヒドロキシブチレート）樹脂が挙げられる。 Specific examples of polysaccharides include cellulose and cellulose acetate resins.
Specific examples of biodegradable polyester resins include polyhydroxyalkane resins such as polyhydroxyalkane resins, polyhydroxyalkanoate resins, polyethylene terephthalate succinate resins, polybutylene adipate terephthalate resins, polybutylene succinate resins, and polybutylene succinate adipate resins. ate resins, polycaprolactone resins, polylactic acid resins, and poly(hydroxybutyrate) resins.
　特に限定するものではないが、一実施形態において、生分解性基材は、セルロースおよび酢酸セルロース樹脂を含むことが好ましい。他の実施形態において、生分解性基材は、ポリビニルアルコール樹脂を含むことが好ましい。さらに他の実施形態において、生分解性基材は、生分解性ポリエステル樹脂を含むことが好ましい。生分解性基材は、生分解性樹脂の他に、必要に応じて、充填剤、可塑剤、および潤滑剤などの各種添加剤を含んでもよい。 Although not particularly limited, in one embodiment, the biodegradable base material preferably contains cellulose and cellulose acetate resin. In other embodiments, the biodegradable substrate preferably comprises polyvinyl alcohol resin. In still other embodiments, the biodegradable substrate preferably comprises a biodegradable polyester resin. The biodegradable base material may contain various additives such as fillers, plasticizers, and lubricants as needed, in addition to the biodegradable resin.
　特に限定するものではないが、多糖類、ポリビニルアルコール樹脂、および生分解性ポリエステル樹脂からなる群から選択される１種以上を含む生分解性基材を使用した場合、上記実施形態の粘着剤組成物から形成される粘着剤層との組合せによって、優れた粘着力を得ることが容易となる傾向がある。一実施形態において、粘着剤組成物におけるウレタンプレポリマー（Ａ）を調製するために使用するポリオール（ａｘ）の数平均分子量が１０,０００を超える場合、上記生分解性基材との密着性が向上し、優れた粘着力を有する粘着シートを容易に構成できる。 Although not particularly limited, when using a biodegradable base material containing one or more selected from the group consisting of polysaccharides, polyvinyl alcohol resins, and biodegradable polyester resins, the adhesive composition of the above embodiment A combination with a pressure-sensitive adhesive layer formed from a material tends to facilitate obtaining excellent adhesive strength. In one embodiment, when the number average molecular weight of the polyol (ax) used to prepare the urethane prepolymer (A) in the pressure-sensitive adhesive composition exceeds 10,000, the adhesion with the biodegradable substrate is It is possible to easily form a pressure-sensitive adhesive sheet having improved and excellent adhesive strength.
　上記生分解性基材を形成するために使用できる生分解性樹脂は、市販品として入手することもできる。一例として、以下が挙げられる。
・セルロース
　日本製紙ケミカル社製、溶解パルプ
・酢酸セルロース（ＣＡ）樹脂
　ダイセル社製、Ｌ－シリーズ
・ポリビニルアルコール樹脂
　三菱ケミカル社製、ニチゴーＧポリマー
・ポリヒドロキシアルカノエート樹脂
　ポリエチレンテレフタレートサクシネート（ＰＥＴＳ）樹脂：Ｄｕｐｏｎ社製、Ａｐｅｘａ４０２６／６９２６
　ポリブチレンアジペートテレフタレート（ＰＢＡＴ）樹脂；ＢＡＳＦ社製、エコフレックス
　ポリブチレンサクシネート（ＰＢＳ）樹脂：ＰＴＴ　ＭＣＣ　バイオケム社製、ＢｉｏＰＢＳ　ＦＺ７１、ＦＺ９１、およびＦＺ７８
　ポリブチレンサクシネートアジペート（ＰＢＳＡ）樹脂：ＰＴＴ　ＭＣＣ　バイオケム社製、ＢｉｏＰＢＳ　ＦＤ９２
　ポリ乳酸（ＰＬＡ）樹脂：（ＮａｔｕｒｔｅＷｏｒｋｓ社製、３０００～７０００シリーズ
　ポリ（３－ヒドロキシブチレート）（Ｐ３ＨＢ）樹脂：ＰＨＢ　Ｉｎｄｕｓｔｏｒｉａｌ社製ＢＩＯＣＹＣＬＥ　１０００）、
　ポリ（４－ヒドロキシブチレート）（Ｐ４ＨＢ）樹脂（Ｔｅｐｈａ　Ｍｅｄｉｃａｌ　Ｄｅｖｉｃｅｓ社製ＴｅｐｈａＦＬＥＸ）、
　ポリ（３－ヒドロキシブチレート－ｃｏ－３－ヒドロキシヘキサノエート）（ＰＨＢＨＨｘ）樹脂（カネカ社製ＡＯＮＩＬＥＸ）、
　ポリ（３－ヒドロキシブチレート－ｃｏ－３－ヒドロキシバレレート（ＰＨＢＨＶ）樹脂（ＴｉａｎＡｎ　Ｂｉｏｐｏｌｙｍｅｒ社製ＥＮＭＡＴ　Ｙ１０００）、
　ポリ（３－ヒドロキシブチレート－ｃｏ－４－ヒドロキシブチレート）（ＰＨＢＨＢ）樹脂（ＣＪ　ＣｈｅｉｌＪｅｄａｎｇ社製Ｙｉｅｌｄ１０）等
・ポリカプロラクトン樹脂
　ダイセル社製、プラクセル　Ｈ１Ｐ、Ｈ５Ｃ、およびＨ８Ｃ Biodegradable resins that can be used to form the biodegradable substrate are also commercially available. Examples include:
・Cellulose Dissolving pulp ・Cellulose acetate (CA) resin manufactured by Nippon Paper Chemicals Co., Ltd. L-series ・Polyvinyl alcohol resin manufactured by Daicel Corporation Nichigo G-polymer ・Polyhydroxyalkanoate resin manufactured by Mitsubishi Chemical Co., Ltd. Polyethylene terephthalate succinate (PETS) resin : Apexa4026/6926 manufactured by Dupon
Polybutylene adipate terephthalate (PBAT) resin; manufactured by BASF, Ecoflex Polybutylene succinate (PBS) resin: PTT MCC Biochem, BioPBS FZ71, FZ91, and FZ78
Polybutylene succinate adipate (PBSA) resin: PTT MCC Biochem, BioPBS FD92
Polylactic acid (PLA) resin: (manufactured by NaturteWorks, 3000-7000 series poly(3-hydroxybutyrate) (P3HB) resin: BIOCYCLE 1000 manufactured by PHB Industrial),
Poly(4-hydroxybutyrate) (P4HB) resin (TephaFLEX from Tepha Medical Devices),
Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) resin (AONILEX manufactured by Kaneka),
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBHV) resin (ENMAT Y1000 from TianAn Biopolymer),
Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (PHBHB) resin (Yield 10 from CJ CheilJedang), etc. Polycaprolactone resin Plaxel H1P, H5C, and H8C from Daicel
　一実施形態において、生分解性基材は、セルロース樹脂、酢酸セルロース樹脂、ポリブチレンアジペートテレフタレート、ポリブチレンサクシネート、ポリ乳酸、およびポリ（３－ヒドロキシブチレート－ｃｏ－３－ヒドロキシヘキサノエート）からなる群から選択される少なくとも１種の生分解性樹脂を用いて形成される基材であることが好ましい。 In one embodiment, the biodegradable substrate is cellulose resin, cellulose acetate resin, polybutylene adipate terephthalate, polybutylene succinate, polylactic acid, and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) The substrate is preferably formed using at least one biodegradable resin selected from the group consisting of:
　上記生分解性基材は、上記生分解性樹脂の他に、生分解性を促進する脂肪酸金属塩を含む分解処理液で処理された樹脂を用いて形成することもできる。このような樹脂の市販品として、例えば、ピーライフ・ジャパン・インク社製、Ｐ－ＬＩＦＥ　ＧＲＥＥＮ　２０（ＰＥ樹脂、分解処理液として同社製のＳＭＣ２３６０を２０％含有）、およびＰ－ＬＩＦＥ　ＧＲＥＥＮ　２０（ＰＰ樹脂、分解処理液として同社製のＳＭＣ２３６０を２０％含有）等が挙げられる。 In addition to the biodegradable resin, the biodegradable base material can also be formed using a resin treated with a decomposition treatment liquid containing a fatty acid metal salt that promotes biodegradability. Commercially available products of such resins include, for example, P-LIFE GREEN 20 (PE resin, containing 20% SMC 2360 manufactured by P-LIFE Japan Inc. as a decomposition treatment liquid), and P-LIFE GREEN 20 ( PP resin, containing 20% of SMC2360 manufactured by the same company as a decomposition treatment liquid), and the like.
　基材を形成するために、生分解性樹脂をフィルムまたはシートの形状に成形加工する方法は特に限定されない。例えば、押出機を用いてＴダイから押出した生分解性樹脂のフィルムまたはシートをキャストロールで冷却固化する押出成形、またはインフレーション成形機を用いて成形する方法等を適用することができる。 The method of molding the biodegradable resin into a film or sheet to form the base material is not particularly limited. For example, a method of extrusion molding in which a biodegradable resin film or sheet extruded from a T-die using an extruder is cooled and solidified with a cast roll, or a method of molding using an inflation molding machine can be applied.
　粘着シートの製造方法としては、例えば、基材の表面（片面または両面）に上記実施形態の粘着剤組成物を塗工して塗工層を形成し、次いで塗工層を乾燥および硬化して、粘着剤層を形成する方法が挙げられる。加熱および乾燥温度は、一般的に６０～１５０℃であってよい。粘着剤層の厚みは、一般的に０．１～２００μｍであってよい。 As a method for producing a pressure-sensitive adhesive sheet, for example, the pressure-sensitive adhesive composition of the above embodiment is applied to the surface (one side or both sides) of a substrate to form a coating layer, and then the coating layer is dried and cured. , and a method of forming an adhesive layer. Heating and drying temperatures may generally range from 60 to 150°C. The thickness of the adhesive layer may generally be 0.1-200 μm.
　塗布方法としては、公知の方法であってよく、例えば、ロールコーター法、コンマコーター法、ダイコーター法、リバースコーター法、シルクスクリーン法、およびグラビアコーター法等が挙げられる。 The coating method may be a known method, such as roll coater method, comma coater method, die coater method, reverse coater method, silk screen method, and gravure coater method.
　また、上記方法とは別の方法として、剥離シートの表面に上記実施形態の粘着剤組成物を塗工して塗工層を形成し、次いで塗工層を乾燥および硬化することによって粘着剤層を形成し、最後に粘着剤層の露出面に基材を貼り合わる方法が挙げられる。この方法において、基材の代わりに剥離シートを粘着剤層に貼り合わせると、剥離シート／粘着剤層／剥離シートの構成を有するキャスト粘着シートが得られる。 Further, as a method different from the above method, the pressure-sensitive adhesive composition of the above-described embodiment is applied to the surface of a release sheet to form a coating layer, and then the coating layer is dried and cured to form a pressure-sensitive adhesive layer. is formed, and finally a substrate is attached to the exposed surface of the pressure-sensitive adhesive layer. In this method, a cast adhesive sheet having a configuration of release sheet/adhesive layer/release sheet can be obtained by laminating a release sheet to the adhesive layer instead of the substrate.
　以下、本発明の実施態様について実施例によって説明する。なお、本発明の実施態様が実施例に限定されないことはいうまでもない。以下に記載する「部」は「質量部」を意味し、「％」は「質量％」を意味する。
　また、以下に記載する実施例および表に記載された原料（溶剤を除く）の配合量は、不揮発分換算の値である。 Embodiments of the present invention will now be described with reference to examples. In addition, it cannot be overemphasized that the embodiment of this invention is not limited to an Example. "Part" described below means "mass part", and "%" means "% by mass".
In addition, the blending amounts of raw materials (excluding solvents) described in the examples and tables described below are values in terms of non-volatile matter.
　さらに、以下に記載するＭｗ，Ｍｎ、およびＴｇは、以下のようにして測定した値である。
［重量平均分子量（Ｍｗ）、および数平均分子量（Ｍｎ）の測定］
　重量平均分子量（Ｍｗ）および数平均分子量（Ｍｎ）は、ゲルパーミエーションクロマトグラフィ（ＧＰＣ）法により測定した。測定条件は、以下のとおりである。なお、ＭｗおよびＭｎはいずれも、ポリスチレン換算値である。
（測定条件）
　装置：ＳＨＩＭＡＤＺＵＰｒｏｍｉｎｅｎｃｅ（島津製作所社製）
　カラム：ＳＨＯＤＥＸＬＦ－８０４（昭和電工社製）を３本直列に接続
　検出器：示差屈折率検出器
　溶媒：テトラヒドロフラン（ＴＨＦ）
　流速：０．５ｍＬ／分
　溶媒温度：４０℃
　試料濃度：０．１％
　試料注入量：１００μＬ Furthermore, Mw, Mn, and Tg described below are values measured as follows.
[Measurement of weight average molecular weight (Mw) and number average molecular weight (Mn)]
Weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) method. Measurement conditions are as follows. Both Mw and Mn are polystyrene equivalent values.
(Measurement condition)
Apparatus: SHIMADZUProminence (manufactured by Shimadzu Corporation)
Column: 3 SHODEXLF-804 (manufactured by Showa Denko) connected in series Detector: Differential refractive index detector Solvent: Tetrahydrofuran (THF)
Flow rate: 0.5 mL/min Solvent temperature: 40°C
Sample concentration: 0.1%
Sample injection volume: 100 μL
［ガラス転移温度（Ｔｇ）］
　ロボットＤＳＣ（示差走査熱量計、セイコーインスツルメンツ社製「ＲＤＣ２２０」）に「ＳＳＣ５２００ディスクステーション」（セイコーインスツルメンツ社製）を接続して、測定に使用した。約１０ｍｇの試料をアルミニウムパンに入れ、秤量して示差走査熱量計にセットし、試料を入れない同タイプのアルミニウムパンをリファレンスとして、１００℃の温度で５分間保持した後、液体窒素を用いて－１２０℃まで急冷した。その後、昇温速度１０℃／分で昇温し、得られたＤＳＣチャートからガラス転移温度（Ｔｇ、単位：℃）を決定した。 [Glass transition temperature (Tg)]
A robot DSC (differential scanning calorimeter, "RDC220" manufactured by Seiko Instruments Inc.) was connected to "SSC5200 Disk Station" (manufactured by Seiko Instruments Inc.) and used for measurement. Place about 10 mg of sample in an aluminum pan, weigh and set in a differential scanning calorimeter, hold the same type of aluminum pan without a sample as a reference at a temperature of 100 ° C. for 5 minutes, and then use liquid nitrogen to Quenched to -120°C. Thereafter, the temperature was raised at a rate of temperature increase of 10°C/min, and the glass transition temperature (Tg, unit: °C) was determined from the obtained DSC chart.
＜１＞原料
　表に示した原料は、以下のとおりである。
＜ポリオール（ａｘ）＞
［単量体（ａｘ’１）］
　Ｌ－乳酸（バイオマス度１００％、生分解性度１００％）
　Ｄ－乳酸（バイオマス度１００％、生分解性度１００％）
　Ｌ－ラクチド（バイオマス度１００％、生分解性度１００％）
　Ｄ－ラクチド（バイオマス度１００％、生分解性度１００％）
　ＤＬ－ラクチド（バイオマス度１００％、生分解性度１００％）
　ｍｅｓｏ－ラクチド（バイオマス度１００％、生分解性度１００％） <1> Raw materials The raw materials shown in the table are as follows.
<Polyol (ax)>
[monomer (ax′1)]
L-lactic acid (100% biomass, 100% biodegradability)
D-lactic acid (100% biomass, 100% biodegradability)
L-lactide (100% biomass, 100% biodegradability)
D-lactide (100% biomass, 100% biodegradability)
DL-lactide (100% biomass, 100% biodegradability)
meso-lactide (100% biomass, 100% biodegradability)
［単量体（ａｘ’２）］
　６－ヒドロキシカプロン酸（バイオマス度０％、生分解性度１００％）
　ε－カプロラクトン（バイオマス度０％、生分解性度１００％） [monomer (ax′2)]
6-hydroxycaproic acid (0% biomass, 100% biodegradability)
ε-Caprolactone (0% biomass, 100% biodegradability)
［単量体（ａｘ’３）］
　ＰＤ：１，３－プロパンジオール、Ｍｎ７６、水酸基数２、（バイオマス度１００％、生分解性度１００％）
　ＰＰＧ６００：サンニックス　ＰＰ－６００、ポリオキシプロピレングリコール、Ｍｎ６００、水酸基数２、三洋化成工業社製（バイオマス度０％、生分解性度０％）
　Ｐ－１０１０：クラレポリオールＰ－１０１０、３－メチル－１，５－ペンタンジオール／アジピン酸、ポリエステルポリオール、Ｍｎ１，０００、クラレ社製（バイオマス度０％、生分解性度０％）
　Ｐ－２０１０：クラレポリオールＰ－２０１０、３－メチル－１，５－ペンタンジオール／アジピン酸、ポリエステルポリオール、Ｍｎ２，０００、クラレ社製（バイオマス度０％、生分解性度０％）
　ＨＦ－１３００：ＵＲＩＣ　ＨＦ－１３００、ヒマシ油ポリオール、Ｍｎ１，４００、水酸基数２、伊藤製油社製（バイオマス度１００％、生分解性度０％）
　ポリオールａｘ’３－１～ａｘ’３－３：後述のとおり。 [monomer (ax'3)]
PD: 1,3-propanediol, Mn76, hydroxyl number 2, (100% biomass, 100% biodegradability)
PPG600: Sannics PP-600, polyoxypropylene glycol, Mn600, hydroxyl number 2, manufactured by Sanyo Chemical Industries, Ltd. (0% biomass, 0% biodegradability)
P-1010: Kuraray polyol P-1010, 3-methyl-1,5-pentanediol/adipic acid, polyester polyol, Mn 1,000, manufactured by Kuraray Co., Ltd. (0% biomass, 0% biodegradability)
P-2010: Kuraray polyol P-2010, 3-methyl-1,5-pentanediol/adipic acid, polyester polyol, Mn 2,000, manufactured by Kuraray Co., Ltd. (0% biomass, 0% biodegradability)
HF-1300: URIC HF-1300, castor oil polyol, Mn 1,400, number of hydroxyl groups 2, manufactured by Ito Oil (100% biomass, 0% biodegradability)
Polyols ax'3-1 to ax'3-3: as described later.
＜多官能ポリオール（ａｙ）＞
　Ｆ－１０１０：クラレポリオールＦ－１０１０、３－メチル－１，５－ペンタンジオール／アジピン酸／トリメチロールプロパンポリエステルポリオール、Ｍｎ１，０００、水酸基数３、クラレ社製（バイオマス度０％、生分解性度０％）
　ＧＬ－６００：サンニックス　ＰＰ－６００、グリセリン／ＰＯ／ＥＯ、ポリオキシプロピレングリコール、Ｍｎ６００、水酸基数３、三洋化成工業社製（バイオマス度０％、生分解性度０％）
　ＧＩ３０００：ＮＩＳＳＯ－ＰＢＧＩ－３０００、ポリブタジエンポリオール、Ｍｎ３，１００、水酸基数２、日本曹達社製（バイオマス度０％、生分解性度０％）
　Ｐｌａｃｃｅｌ４１０：ポリカプロラクトンポリオール、Ｍｎ１，０１０、水酸基数４、ダイセル社製（バイオマス度０％、生分解性度１００％） <Polyfunctional polyol (ay)>
F-1010: Kuraray polyol F-1010, 3-methyl-1,5-pentanediol/adipic acid/trimethylolpropane polyester polyol, Mn 1,000, number of hydroxyl groups 3, manufactured by Kuraray Co., Ltd. (0% biomass, biodegradable degree 0%)
GL-600: Sannics PP-600, glycerin/PO/EO, polyoxypropylene glycol, Mn600, 3 hydroxyl groups, manufactured by Sanyo Chemical Industries (0% biomass, 0% biodegradability)
GI3000: NISSO-PBGI-3000, polybutadiene polyol, Mn 3,100, number of hydroxyl groups 2, manufactured by Nippon Soda Co., Ltd. (0% biomass, 0% biodegradability)
Placel 410: polycaprolactone polyol, Mn 1,010, number of hydroxyl groups 4, manufactured by Daicel (0% biomass, 100% biodegradability)
＜ポリイソシアネート（ａｚ）＞
　ＩＰＤＩ：イソホロンジイソシアネート
　ＨＤＩ：ヘキサメチレンジイソシアネート
　ＸＤＩ：ｍ－キシレンジイソシアネート <Polyisocyanate (az)>
IPDI: isophorone diisocyanate HDI: hexamethylene diisocyanate XDI: m-xylene diisocyanate
＜硬化剤＞
［イソシアネート硬化剤（Ｂ）］
　ＨＤＩ－ＴＭＰ：ヘキサメチレンジイソシアネートのトリメチロールプロパンアダクト体、タケネートＤ－１６０Ｎ、三井化学社製
　ＸＤＩ－ＴＭＰ：キシレンジイソシアネートのトリメチロールプロパンアダクト体、タケネートＤ－１１０Ｎ、三井化学社製
　ＴＤＩ－Ｎｕ：トリレンジイソシアネートのイソシアヌレート体、タケネートＤ－２０４、三井化学社製［カルボジイミド硬化剤］
　Ｖ－０９Ｂ：カルボジイミド、カルボジライドＶ－０９Ｂ、日清紡ケミカル社製 <Curing agent>
[Isocyanate curing agent (B)]
HDI-TMP: Trimethylolpropane adduct of hexamethylene diisocyanate, Takenate D-160N, manufactured by Mitsui Chemicals XDI-TMP: Trimethylolpropane adduct of xylene diisocyanate, Takenate D-110N, manufactured by Mitsui Chemicals TDI-Nu: Tri Isocyanurate form of diisocyanate, Takenate D-204, manufactured by Mitsui Chemicals [carbodiimide curing agent]
V-09B: carbodiimide, carbodilide V-09B, manufactured by Nisshinbo Chemical Co., Ltd.
＜粘着付与樹脂＞
　Ａ－７５：スーパーエステルＡ－７５、ロジン系樹脂、荒川化学社製（バイオマス度９２％、生分解性度０％）
　Ｄ－１２５：ペンセルＤ－１２５、ロジン系樹脂、荒川化学社製（バイオマス度８５％、生分解性度０％） <Tackifying resin>
A-75: Superester A-75, rosin resin, manufactured by Arakawa Chemical Co., Ltd. (92% biomass, 0% biodegradability)
D-125: Pencel D-125, rosin resin, manufactured by Arakawa Chemical Co., Ltd. (85% biomass, 0% biodegradability)
　上記原料において、バイオマス度は、製造時に使用したバイオマス由来の原料の質量割合（質量％）、またはＡＳＴＭ　Ｄ６８６６に基づいた含有率である。 In the above raw materials, the biomass content is the mass ratio (mass%) of the biomass-derived raw materials used during production, or the content based on ASTM D6866.
　上記原料における生分解性は、ＩＳＯ　１７５５６、ＩＳＯ　１４８５１、ＩＳＯ　１４８５２、ＩＳＯ　１５９８５、ＩＳＯ　１３９７５、ＩＳＯ　１４８５３、ＩＳＯ　１４８５５－１、ＩＳＯ　１４８５５－２、ＩＳＯ　１８８３０、ＩＳＯ　１９６７９、ＡＳＴＭ　Ｄ７０８１、およびＡＳＴＭ　Ｄ６６９１等、並びにＩＳＯ規格に対応するＪＩＳ規格に基づき決定した。生分解性が認められる場合、原料の生分解性度を１００％とした。 ISO 17556, ISO 14851, ISO 14852, ISO 15985, ISO 13975, ISO 14853, ISO 14855-1, ISO 14855-2, ISO 18830, ISO 19679, ASTM D7081, and ASTM D6691, etc. Also, it was determined based on the JIS standard corresponding to the ISO standard. When biodegradability was recognized, the degree of biodegradability of the raw material was defined as 100%.
＜２＞ポリオール（ａｘ’３）の製造例
（ポリオール（ａｘ’３－１））
　バイオマス由来の原料からなり、かつ生分解性原料でもあるセバシン酸と、１,３－プロパンジオールとを重合して、数平均分子量が１，０００であるポリエステルポリオール（ａｘ’３－１）を得た。ポリオール（ａｘ’３－１）のバイオマス度は１００％であり、生分解性度は１００％であった。 <2> Production example of polyol (ax'3) (polyol (ax'3-1))
A polyester polyol (ax'3-1) having a number average molecular weight of 1,000 is obtained by polymerizing sebacic acid, which is a raw material derived from biomass and is also a biodegradable raw material, and 1,3-propanediol. rice field. The polyol (ax'3-1) had a biomass degree of 100% and a biodegradability of 100%.
（ポリオール（ａｘ’３－２））
　バイオマス由来の原料からなり、かつ生分解性原料でもあるコハク酸と、１,３－プロパンジオールとを重合して、数平均分子量が８００であるポリエステルポリオール（ａｘ’３－２）を得た。ポリオール（ａｘ’３－２）のバイオマス度は１００％であり、生分解性度は１００％であった。 (Polyol (ax'3-2))
A polyester polyol (ax'3-2) having a number average molecular weight of 800 was obtained by polymerizing succinic acid, which is a raw material derived from biomass and is also a biodegradable raw material, and 1,3-propanediol. The polyol (ax'3-2) had a biomass degree of 100% and a biodegradability of 100%.
（ポリオール（ａｘ’３－３））
　バイオマス由来の原料からなり、かつ生分解性原料でもあるコハク酸と、１,３－プロパンジオールとを重合して、数平均分子量が２００であるポリエステルポリオール（ａｘ’３－３）を得た。ポリオール（ａｘ’３－３）のバイオマス度は１００％であり、生分解性度は１００％であった。 (Polyol (ax'3-3))
A polyester polyol (ax′3-3) having a number average molecular weight of 200 was obtained by polymerizing succinic acid, which is a raw material derived from biomass and is also a biodegradable raw material, and 1,3-propanediol. The polyol (ax'3-3) had a biomass degree of 100% and a biodegradability degree of 100%.
＜３＞ポリオール（ａｘ）の製造例
（ポリオール（ａｘ－１））
　ディーンスタークトラップを設置した反応缶内に、Ｌ－乳酸１００部、６－ヒドロキシカプロン酸３５部、および錫粉末０．６部を仕込んだ。これらを、１５０℃／５０ｍｍＨｇで３時間撹拌しながら水を留出させ、その後、１５０℃／３０ｍｍＨｇでさらに２時間撹拌した。次いで、この反応溶液に、ジフェニルエーテル２１０部を加え、１５０℃／３５ｍｍＨｇで共沸脱水反応を行い、留出した水と溶媒とを水分離器で分離して、溶媒のみを反応缶に戻した。２時間後、モレキュラシーブ３Ａを充填したカラムに通してから反応缶に戻るようにして、１３０℃／１７ｍｍＨｇで１０時間反応を行った。その後、反応溶液にプロパンジオール（ＰＤ）６．０部を加え、１３０℃／１７ｍｍＨｇで1０時間反応を行い、反応を終了させた。
　上記のようにして得た反応溶液に、脱水したジフェニルエーテル４４０部を加えて希釈した後、４０℃まで冷却して、析出した結晶を瀘過した。この結晶に０．５Ｎ－ＨＣｌ１２０部とエタノール１２０部とを加え、３５℃で１時間撹拌した後に瀘過した。得られた固形物を６０℃／５０ｍｍＨｇで乾燥して、ポリオール（ａｘ－１）を得た。このポリオール（ａｘ－１）の数平均分子量（Ｍｎ）は１，７００であった。 <3> Production example of polyol (ax) (polyol (ax-1))
100 parts of L-lactic acid, 35 parts of 6-hydroxycaproic acid, and 0.6 parts of tin powder were charged into a reactor equipped with a Dean-Stark trap. These were stirred at 150° C./50 mmHg for 3 hours to distill off the water, and then stirred at 150° C./30 mmHg for an additional 2 hours. Next, 210 parts of diphenyl ether was added to this reaction solution, and azeotropic dehydration was carried out at 150° C./35 mmHg. Distilled water and solvent were separated by a water separator, and only the solvent was returned to the reactor. After 2 hours, the reaction was carried out at 130° C./17 mmHg for 10 hours by passing it through a column packed with molecular sieve 3A and returning it to the reactor. Then, 6.0 parts of propanediol (PD) was added to the reaction solution, and the reaction was carried out at 130° C./17 mmHg for 10 hours to complete the reaction.
After diluting the reaction solution obtained by adding 440 parts of dehydrated diphenyl ether, the solution was cooled to 40° C. and the precipitated crystals were filtered. 120 parts of 0.5N-HCl and 120 parts of ethanol were added to the crystals, and the mixture was stirred at 35°C for 1 hour and filtered. The resulting solid was dried at 60° C./50 mmHg to obtain polyol (ax-1). The number average molecular weight (Mn) of this polyol (ax-1) was 1,700.
（ポリオール（ａｘ－２、ａｘ－３））
　配合量（質量部）を表１に示すとおりに変更し、ポリオール（ａｘ－１）の製造と同様にして、それぞれポリオール（ａｘ－２、ａｘ－３）を得た。
　得られたポリオールの数平均分子量（Ｍｎ）を表１に示す。 (Polyol (ax-2, ax-3))
Polyols (ax-2, ax-3) were obtained in the same manner as in the production of polyol (ax-1) by changing the blending amount (parts by mass) as shown in Table 1.
Table 1 shows the number average molecular weight (Mn) of the obtained polyol.
（ポリオール（ａｘ－４））
　撹拌機、温度計、流出用冷却機を装備した反応缶内に、表１に示すように、Ｌ－ラクチド１００部、ε－カプロラクトン４００部、Ｐ－１０１０ ５００部、および触媒として２－エチルオクチル酸錫０．１部を仕込んだ。これら材料を、窒素雰囲気の常圧下で、５時間かけて１７０℃まで昇温させた後、３時間反応させ、留出する水を系外に除去し、重合反応を行った。
　その後、１０ｍｍＨｇまで減圧しながら、残存する未反応の単量体を３時間かけて除去し、ポリオール（ａｘ－４）を得た。このポリオール（ａｘ－４）の数平均分子量（Ｍｎ）は、２，０００であった。 (Polyol (ax-4))
Into a reactor equipped with a stirrer, thermometer, and outflow cooler, 100 parts of L-lactide, 400 parts of ε-caprolactone, 500 parts of P-1010, and 2-ethyloctyl as a catalyst were added as shown in Table 1. 0.1 part of tin oxide was charged. These materials were heated to 170° C. over 5 hours under normal pressure in a nitrogen atmosphere, and then reacted for 3 hours. Distilled water was removed from the system, and a polymerization reaction was carried out.
Thereafter, while reducing the pressure to 10 mmHg, the remaining unreacted monomer was removed over 3 hours to obtain polyol (ax-4). The number average molecular weight (Mn) of this polyol (ax-4) was 2,000.
（ポリオール（ａｘ－５～ａｘ－５５、ａｘｃ－１～３））
　配合量（質量部）を表１に示すとおりに変更した以外は、ポリオール（ａｘ－４）の製造と同様にして、それぞれポリオール（ａｘ－５～ａｘ－５５、ａｘｃ－１～ａｘｃ－３）を得た。得られたポリオールの数平均分子量（Ｍｎ）を表１に示す。 (Polyol (ax-5 to ax-55, axc-1 to 3))
Polyols (ax-5 to ax-55, axc-1 to axc-3) were prepared in the same manner as in the production of polyol (ax-4), except that the amount (parts by mass) was changed as shown in Table 1. got Table 1 shows the number average molecular weight (Mn) of the obtained polyol.
　なお、表１において、それぞれの単量体の含有率は、ポリオール（ａｘ）を構成する単量体混合物の全量（１００質量％）を基準とする含有率（質量％）である。単量体（ａｘ’１）／単量体（ａｘ’２）は、単量体（ａｘ’１）の含有量と単量体（ａｘ’２）の含有量の比率である。 In Table 1, the content of each monomer is the content (% by mass) based on the total amount (100% by mass) of the monomer mixture constituting the polyol (ax). Monomer (ax'1)/monomer (ax'2) is the ratio of the content of monomer (ax'1) to the content of monomer (ax'2).
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
＜４＞水酸基を有するウレタンプレポリマー（Ａ）の製造例
（ウレタンプレポリマー（Ａ－１））
　撹拌機、還流冷却管、窒素導入管、温度計、滴下ロートを備えた４口フラスコにポリオール（ａｘ－１）を１００部、Ｆ－１０１０を１２．１部、ＨＤＩを８．７部、触媒としてジオクチル錫ジラウレートを０．０４部、およびトルエンを不揮発分が６０％となる量で仕込んだ。これらの材料を１００℃まで徐々に昇温して、５時間反応を行った。ＩＲチャートのＮＣＯ特性吸収（２，２７０ｃｍ－１）が消失していることを確認した後に、２５℃まで冷却し、アセチルアセトン０．０８部を加え、反応を終了した。
　このようにして得たウレタンプレポリマー（Ａ－１）の重量平均分子量（Ｍｗ）は５０，０００、ガラス転移温度（Ｔｇ）は－１０℃であった。 <4> Production Example of Urethane Prepolymer (A) Having a Hydroxyl Group (Urethane Prepolymer (A-1))
100 parts of polyol (ax-1), 12.1 parts of F-1010, 8.7 parts of HDI, a catalyst 0.04 part of dioctyltin dilaurate and toluene in an amount to give a non-volatile content of 60% were charged as a solution. These materials were gradually heated to 100° C. and reacted for 5 hours. After confirming that the NCO characteristic absorption (2,270 cm −1 ) on the IR chart had disappeared, the mixture was cooled to 25° C. and 0.08 part of acetylacetone was added to complete the reaction.
The urethane prepolymer (A-1) thus obtained had a weight average molecular weight (Mw) of 50,000 and a glass transition temperature (Tg) of -10°C.
（ウレタンプレポリマー（Ａ－２～Ａ－５９、ＡＣ－１～ＡＣ－３））
　ウレタンプレポリマー（Ａ－１）の材料および配合量（質量部）を表２に示すとおりに変更した以外は、ウレタンプレポリマー（Ａ－１）の製造と同様し、不揮発分６０％となるようにトルエンを調整して、それぞれウレタンプレポリマー（Ａ－２～５６、ＡＣ－１～３）を得た。得られたウレタンプレポリマーの重量平均分子量（Ｍｗ）、ガラス転移温度（Ｔｇ）を表２に示す。 (Urethane prepolymers (A-2 to A-59, AC-1 to AC-3))
In the same manner as in the production of urethane prepolymer (A-1), except that the material and amount (parts by mass) of urethane prepolymer (A-1) were changed as shown in Table 2, the non-volatile content was adjusted to 60%. toluene to obtain urethane prepolymers (A-2 to 56, AC-1 to 3) respectively. Table 2 shows the weight average molecular weight (Mw) and glass transition temperature (Tg) of the obtained urethane prepolymer.
　なお、表２において、「ＮＣＯ／ＯＨ」の値は、水酸基を有するウレタンプレポリマー（Ａ）を製造する際のポリイソシアネート（ａｙ）のイソシアネート基（ＮＣＯ）およびポリオール（ａｘ）の水酸基（ＯＨ）とのモル比（ＮＣＯ／ＯＨ）である。 In Table 2, the value of "NCO/OH" is the isocyanate group (NCO) of the polyisocyanate (ay) and the hydroxyl group (OH) of the polyol (ax) when producing the urethane prepolymer (A) having a hydroxyl group. and the molar ratio (NCO/OH).
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000006
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000007
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000008
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
＜５＞粘着剤組成物および粘着シートの製造例
（実施例１）
　ウレタンプレポリマー（Ａ－１）を１００部、イソシアネート硬化剤（Ｂ）として、ＨＤＩ－ＴＭＰを５．０部、および溶剤として酢酸エチルを不揮発分５０％となるように配合し、ディスパーで撹拌して、粘着剤組成物を得た。 <5> Production Example of Adhesive Composition and Adhesive Sheet (Example 1)
100 parts of the urethane prepolymer (A-1), 5.0 parts of HDI-TMP as the isocyanate curing agent (B), and ethyl acetate as the solvent were blended so that the non-volatile content was 50%, and the mixture was stirred with a disper. to obtain an adhesive composition.
　基材として、厚さ５０μｍのポリエチレンテレフタレート（ＰＥＴ）（「ルミラーＴ－６０」、東レ社製）を準備した。コンマコーター（登録商標）を用いて、上記基材上に、先に調製した粘着剤組成物を塗工し、塗工層を形成した。塗工は、塗工速度３ｍ／分、幅３０ｃｍで乾燥後の厚みが２５μｍになるように実施した。次に、形成された塗工層を、乾燥オーブンを使用して、１００℃、１分間の条件で乾燥して、粘着剤層を形成した。この粘着剤層の上に、厚さ３８μｍの市販の剥離シートを貼り合わせ、さらに２３℃、５０％ＲＨの条件下で１週間養生を行うことによって、粘着シート１を得た。 A polyethylene terephthalate (PET) ("Lumirror T-60", manufactured by Toray Industries, Inc.) with a thickness of 50 μm was prepared as a base material. Using a comma coater (registered trademark), the previously prepared pressure-sensitive adhesive composition was applied onto the substrate to form a coating layer. Coating was performed at a coating speed of 3 m/min, a width of 30 cm, and a thickness of 25 μm after drying. Next, the formed coating layer was dried at 100° C. for 1 minute using a drying oven to form an adhesive layer. A commercially available release sheet having a thickness of 38 μm was adhered to the adhesive layer, and cured under conditions of 23° C. and 50% RH for 1 week to obtain an adhesive sheet 1 .
（実施例２～８２、比較例１～４）
　実施例１の材料および配合量（質量部）を表３に示すとおりに変更し、これ以外は実施例１と同様にして、それぞれ実施例２～８２、比較例１～４の粘着剤組成物および粘着シートを得た。 (Examples 2 to 82, Comparative Examples 1 to 4)
The materials and blending amounts (parts by mass) of Example 1 were changed as shown in Table 3, and the pressure-sensitive adhesive compositions of Examples 2 to 82 and Comparative Examples 1 to 4 were prepared in the same manner as in Example 1, respectively. and an adhesive sheet was obtained.
（実施例８３～８８）
　実施例１の材料および配合量（質量部）を表３に示すとおりに変更し、さらに基材を、下記生分解性基材に変更した以外は、実施例１と同様にして、それぞれ実施例８３～８８の粘着剤組成物および粘着シートを得た。
＜生分解性基材＞
　以下に記載する生分解性樹脂を、３０ｍｍΦインフレーション押出機（東測精密工業社製）を用いて温度２３０℃にて押出成形し、厚さ５０μｍの生分解性基材を得た。
　Ｃ：セルロース（日本製紙ケミカル社製、溶解パルプ）
　ＰＢＡＴ：ポリブチレンアジペートテレフタレート（ＢＡＳＦ社製、エコフレックス）
　ＰＢＳ：ポリブチレンサクシネート（ＰＴＴ　ＭＣＣ　バイオケム社製、ＢｉｏＰＢＳ　ＦＺ７１）
　ＰＬＡ：ポリ乳酸、（ＮａｔｕｒｔｅＷｏｒｋｓ社製、４０３２Ｄ）
　ＰＨＢＨＨｘ：ポリ（３－ヒドロキシブチレート－ｃｏ－３－ヒドロキシヘキサノエート）（カネカ社製、ＡＯＮＩＬＥＸ）
　ＣＡ：酢酸セルロース樹脂（ダイセル社製、Ｌ－２０） (Examples 83-88)
In the same manner as in Example 1, except that the materials and blending amounts (parts by mass) of Example 1 were changed as shown in Table 3, and the base material was changed to the following biodegradable base material, each example PSA compositions and PSA sheets of 83 to 88 were obtained.
<Biodegradable base material>
A biodegradable resin described below was extruded at a temperature of 230° C. using a 30 mmΦ inflation extruder (manufactured by Tosoku Seimitsu Kogyo Co., Ltd.) to obtain a biodegradable base material having a thickness of 50 μm.
C: cellulose (manufactured by Nippon Paper Chemicals Co., Ltd., dissolving pulp)
PBAT: polybutylene adipate terephthalate (manufactured by BASF, Ecoflex)
PBS: Polybutylene succinate (PTT MCC Biochem, BioPBS FZ71)
PLA: polylactic acid, (manufactured by NaturteWorks, 4032D)
PHBHHx: Poly (3-hydroxybutyrate-co-3-hydroxyhexanoate) (manufactured by Kaneka, AONILEX)
CA: cellulose acetate resin (manufactured by Daicel, L-20)
＜６＞粘着剤組成物の特性評価
　実施例１～８２、および比較例１～４で得た粘着剤組成物について、以下の方法にしたがい、バイオマス度、および生分解性原料の使用比率を算出した。結果を表３に示す。 <6> Characteristic evaluation of adhesive composition For the adhesive compositions obtained in Examples 1 to 82 and Comparative Examples 1 to 4, the biomass degree and the usage ratio of biodegradable raw materials were calculated according to the following method. did. Table 3 shows the results.
＜粘着剤のバイオマス度＞
　粘着剤のバイオマス度とは、粘着剤の総質量に対し、粘着剤の製造時に使用したバイオマス由来の原料の質量割合であり、以下の計算式（１）にしたがって算出した。なお、各質量は不揮発分換算である。バイオマス度は５％以上が好ましく、１０％以上がより好ましく、２５％以上がさらに好ましい。 <Biomass degree of adhesive>
The biomass degree of the adhesive is the mass ratio of the biomass-derived raw material used in the production of the adhesive to the total mass of the adhesive, and was calculated according to the following formula (1). In addition, each mass is non-volatile content conversion. The biomass degree is preferably 5% or more, more preferably 10% or more, and even more preferably 25% or more.
計算式（１）：
　粘着剤のバイオマス度（質量％）＝１００×［バイオマス由来の原料の質量（ｇ）］／［粘着剤の総質量（ｇ）］ Calculation formula (1):
Biomass degree of adhesive (mass%) = 100 × [mass of raw material derived from biomass (g)] / [total mass of adhesive (g)]
＜粘着剤の生分解性原料の使用比率＞
　粘着剤の生分解性原料の使用比率とは、粘着剤の総質量に対し、粘着剤の製造時に使用した生分解性の原料の質量割合であり、以下の計算式（２）にしたがって算出した。なお、各質量は不揮発分換算である。使用比率は６０％以上であることが好ましい。 <Usage ratio of biodegradable raw materials for adhesives>
The usage ratio of the biodegradable raw material of the adhesive is the mass ratio of the biodegradable raw material used in the production of the adhesive to the total mass of the adhesive, and was calculated according to the following formula (2). . In addition, each mass is non-volatile content conversion. The usage ratio is preferably 60% or more.
計算式（２）：
　粘着剤の生分解性原料の使用比率＝１００×［生分解性原料の使用質量％］／［粘着剤１００質量％］ Calculation formula (2):
Usage ratio of biodegradable raw materials in adhesive = 100 × [% by mass of biodegradable raw materials used] / [100% by mass of adhesive]
＜７＞粘着シートの特性評価
　実施例１～８８、および比較例１～４で得た粘着剤組成物を使用して製造した粘着シートについて、以下の方法にしたがい、各種特性の評価を行った。結果を表３に示す。 <7> Characteristic Evaluation of Adhesive Sheet Various characteristics of the adhesive sheets produced using the adhesive compositions obtained in Examples 1 to 88 and Comparative Examples 1 to 4 were evaluated according to the following methods. . Table 3 shows the results.
＜粘着特性＞
［再剥離力］
　実施例および比較例で製造した粘着シートを、幅２５ｍｍ、長さ１００ｍｍの大きさに切り取り、試料として使用した。この試料を、ステンレス板（ＳＵＳ３０４）に対して、２３℃、５０％ＲＨ雰囲気下で貼着した。次いで、ＪＩＳ０２３７に準じて２Ｋｇロール圧着し、２３℃、５０％ＲＨ雰囲気下で２４時間放置した。その後、引張試験機を用い、２通りの剥離速度で粘着シートをステンレス板から剥離（１８０度ピール）し、糊残りなどの外観を比較した。剥離速度は、低剥離速度（０．３ｍ／分）、および高剥離速度（３０ｍ／分）とした。評価基準は以下のとおりである。
（評価基準）
　　Ａ：ＳＵＳ板を汚染せず粘着シートを剥離できた。優秀。
　　Ｂ：ＳＵＳ板を極わずかに汚染した。良好。
　　Ｃ：ＳＵＳ板をわずかに汚染した。実用可。
　　Ｄ：ＳＵＳ板を汚染した。実用不可。 <Adhesive properties>
[Removal force]
The pressure-sensitive adhesive sheets produced in Examples and Comparative Examples were cut into pieces having a width of 25 mm and a length of 100 mm, and used as samples. This sample was adhered to a stainless steel plate (SUS304) in an atmosphere of 23° C. and 50% RH. Then, according to JIS0237, a 2-kg roll was pressure-bonded and left in an atmosphere of 23° C. and 50% RH for 24 hours. After that, using a tensile tester, the pressure-sensitive adhesive sheet was peeled off from the stainless steel plate at two peeling speeds (180 degree peel), and the appearance such as adhesive residue was compared. The peel speeds were low peel speed (0.3 m/min) and high peel speed (30 m/min). Evaluation criteria are as follows.
(Evaluation criteria)
A: The adhesive sheet could be peeled off without staining the SUS plate. excellence.
B: The SUS plate was very slightly contaminated. Good.
C: The SUS plate was slightly contaminated. Practical.
D: The SUS plate was contaminated. Not practical.
［粘着力］
　実施例および比較例で製造した粘着シートを幅２５ｍｍ、長さ１００ｍｍの大きさに切り取り、試料として使用した。次いで、２３℃、５０％ＲＨ雰囲気下、ＪＩＳ　Ｚ　０２３７に準拠して、試料から剥離シートを剥がし、露出した粘着剤層を、研磨したステンレス（ＳＵＳ）板に貼着した。２ｋｇロールで１往復圧着し、貼着２４時間後に、引張試験機を使用して、剥離速度３００ｍｍ／ｍｉｎ、剥離角度１８０°の条件で、粘着力（Ｎ／２５ｍｍ）を測定した。評価基準は以下のとおりである。
（評価基準）
　　Ａ：粘着力が１５Ｎ／２５ｍｍ以上。優秀。
　　Ｂ：粘着力が１０Ｎ／２５ｍｍ以上、１５Ｎ／２５ｍｍ未満。良好。
　　Ｃ：粘着力が５Ｎ／２５ｍｍ以上、１０Ｎ／２５ｍｍ未満。実用可。
　　Ｄ：粘着力が５Ｎ／２５ｍｍ未満。実用不可。 [Adhesive force]
The pressure-sensitive adhesive sheets produced in Examples and Comparative Examples were cut into pieces having a width of 25 mm and a length of 100 mm, and used as samples. Then, in accordance with JIS Z 0237, the release sheet was peeled off from the sample under an atmosphere of 23° C. and 50% RH, and the exposed adhesive layer was adhered to a polished stainless steel (SUS) plate. After 24 hours of adhesion, the adhesive strength (N/25 mm) was measured using a tensile tester under the conditions of a peel speed of 300 mm/min and a peel angle of 180°. Evaluation criteria are as follows.
(Evaluation criteria)
A: The adhesive strength is 15 N/25 mm or more. excellence.
B: The adhesive strength is 10 N/25 mm or more and less than 15 N/25 mm. Good.
C: Adhesive strength of 5 N/25 mm or more and less than 10 N/25 mm. Practical.
D: The adhesive strength is less than 5 N/25 mm. Not practical.
［保持力］
　実施例および比較例で製造した粘着シートから剥離シートを剥がし、露出した粘着剤層の部分（粘着シートの先端部、幅２５ｍｍ、長さ２５ｍｍ）を、研磨したステンレス（ＳＵＳ）板に貼着し、２ｋｇロールで１往復圧着した。その後、８０℃の雰囲気で１ｋｇの荷重をかけ、７万秒にわたって保持した。評価は、ＳＵＳ板から試料が落下した場合はその秒数を示す。試料が落下しなかった場合は、ＳＵＳ板に対する粘着剤層の接着部（粘着シートの先端部）が、荷重によって下にずれたｍｍ数を示す。評価基準は以下のとおりである。
（評価基準）
　　Ａ：試料のずれが２ｍｍ未満。優秀。
　　Ｂ：試料のずれが２ｍｍ以上５ｍｍ未満。良好。
　　Ｃ：試料のずれが５ｍｍ以上で落下しなかった。実用可。
　　Ｄ：試料が落下した。実用不可。 [Holding power]
The release sheet was peeled off from the pressure-sensitive adhesive sheets produced in Examples and Comparative Examples, and the exposed pressure-sensitive adhesive layer portion (tip of pressure-sensitive adhesive sheet, width 25 mm, length 25 mm) was adhered to a polished stainless steel (SUS) plate. , and press-bonded once with a 2 kg roll. After that, a load of 1 kg was applied in an atmosphere of 80° C. and held for 70,000 seconds. The evaluation indicates the number of seconds when the sample dropped from the SUS plate. When the sample did not fall, the number of millimeters by which the adhesive layer adhered to the SUS plate (tip of the adhesive sheet) shifted downward due to the load. Evaluation criteria are as follows.
(Evaluation criteria)
A: Sample deviation is less than 2 mm. excellence.
B: Sample displacement is 2 mm or more and less than 5 mm. Good.
C: The sample was displaced by 5 mm or more and did not drop. Practical.
D: The sample fell. Not practical.
［初期硬化性］
　初期硬化性の評価に使用する粘着シートを以下のようにして製造した。
　基材として厚さ５０μｍのポリエチレンテレフタレート（ＰＥＴ）（「ルミラーＴ－６０」、東レ社製）を準備した。コンマコーター（登録商標）を用い、基材上に、実施例および比較例で得た各粘着剤組成物を、塗工速度３０ｍ／分、幅１５０ｃｍで、乾燥後の厚みが２５μｍになるように塗工し、塗工層を形成した。次に、形成された塗工層を、乾燥オーブンを使用して１００℃１分間の条件で乾燥して、粘着剤層を形成した。この粘着剤層の上に、厚さ３８μｍの市販の剥離シートを貼り合わせ、さらに２３℃、５０％ＲＨの条件下で１週間養生を行うことで、粘着シートを得た。
　上記のようにして得た粘着シートについて、剥離シートを剥がし、剥がした後に露出した粘着剤層の表面（塗工面）の状態を指触タック試験にて検討し、指への糊残りの有無を評価した。評価基準は以下のとおりである。
（評価基準）
　　Ａ：指へ粘着剤が転着しなかった。優秀。
　　Ｂ：指へ粘着剤が極わずかに転着した。良好。
　　Ｃ：指へ粘着剤がわずかに転着した。実用可。
　　Ｄ：指へ粘着剤が転着した。実用不可。 [Initial Curability]
A pressure-sensitive adhesive sheet used for evaluation of initial curability was produced as follows.
A polyethylene terephthalate (PET) (“Lumirror T-60” manufactured by Toray Industries, Inc.) having a thickness of 50 μm was prepared as a base material. Using a comma coater (registered trademark), each pressure-sensitive adhesive composition obtained in Examples and Comparative Examples was applied onto a base material at a coating speed of 30 m/min, a width of 150 cm, and a thickness of 25 μm after drying. It was coated to form a coating layer. Next, the formed coating layer was dried at 100° C. for 1 minute using a drying oven to form an adhesive layer. A commercially available release sheet having a thickness of 38 μm was adhered to the adhesive layer, and cured under conditions of 23° C. and 50% RH for 1 week to obtain an adhesive sheet.
With respect to the pressure-sensitive adhesive sheet obtained as described above, the release sheet was peeled off, and the state of the surface (coated surface) of the pressure-sensitive adhesive layer exposed after peeling was examined by a finger tack test, and the presence or absence of adhesive residue on the finger was examined. evaluated. Evaluation criteria are as follows.
(Evaluation criteria)
A: The adhesive did not transfer to the finger. excellence.
B: The adhesive was very slightly transferred to the finger. Good.
C: The adhesive was slightly transferred to the finger. Practical.
D: The adhesive transferred to the finger. Not practical.
＜耐湿熱性＞
［被着体に対する汚染性］
　実施例および比較例で製造した粘着シートを幅２５ｍｍ、長さ１００ｍｍの大きさに切り出し試料として使用した。この試料を、ステンレス板（ＳＵＳ３０４）に対して２３℃、５０％ＲＨ雰囲気下で貼着し、さらにＪＩＳ０２３７に準じて２Ｋｇロール圧着した。次いで、６０℃、９５％ＲＨ雰囲気下に７２時間放置した後、粘着シートを剥離し、剥離後のＳＵＳ板の表面を目視で評価することによって、粘着剤層の再剥離性を評価した。評価基準は以下のとおりである。
（評価基準）
　Ａ：ＳＵＳ板を汚染しなかった。優秀。
　Ｂ：ＳＵＳ板を極わずかに汚染した。良好。
　Ｃ：ＳＵＳ板をわずかに汚染した。実用可。
　Ｄ：ＳＵＳ板を汚染した。実用不可。 <Damp heat resistance>
[Staining property to adherend]
The pressure-sensitive adhesive sheets produced in Examples and Comparative Examples were cut into pieces having a width of 25 mm and a length of 100 mm and used as samples. This sample was adhered to a stainless steel plate (SUS304) at 23° C. and 50% RH, and further pressure-bonded with a 2 kg roll according to JIS0237. Then, the pressure-sensitive adhesive sheet was peeled off after being left in an atmosphere of 60° C. and 95% RH for 72 hours, and the peelability of the pressure-sensitive adhesive layer was evaluated by visually evaluating the surface of the SUS plate after peeling. Evaluation criteria are as follows.
(Evaluation criteria)
A: The SUS plate was not contaminated. excellence.
B: The SUS plate was very slightly contaminated. Good.
C: The SUS plate was slightly contaminated. Practical.
D: The SUS plate was contaminated. Not practical.
＜低温耐性＞
［被着体に対する密着性］
　実施例および比較例で製造した粘着シートを幅２５ｍｍ、長さ１００ｍｍの大きさに切り取り、試料とした。次いで、－５℃雰囲気下、ＪＩＳ Ｚ ０２３７に準拠して、試料から剥離シートを剥がし、露出した粘着剤層を研磨したステンレス板（ＳＵＳ３０４）に貼り付け、さらに２ｋｇロールで１往復圧着した。貼着２４時間後に、引張試験機を使用して、剥離速度３００ｍｍ／ｍｉｎ、剥離角度１８０°の条件で、粘着力（Ｎ／２５ｍｍ）を測定した。評価基準は以下のとおりである。
（評価基準）
　Ａ：粘着力が１５Ｎ／２５ｍｍ以上。優秀。
　Ｂ：粘着力が１０Ｎ／２５ｍｍ以上、１５Ｎ／２５ｍｍ未満。良好。
　Ｃ：粘着力が５Ｎ／２５ｍｍ以上、１０Ｎ／２５ｍｍ未満。実用可。
　Ｄ：粘着力が５Ｎ／２５ｍｍ未満。実用不可。 <Low temperature resistance>
[Adhesion to adherend]
The pressure-sensitive adhesive sheets produced in Examples and Comparative Examples were cut into pieces having a width of 25 mm and a length of 100 mm to obtain samples. Then, in an atmosphere of −5° C., according to JIS Z 0237, the release sheet was peeled off from the sample, and the exposed adhesive layer was attached to a polished stainless steel plate (SUS304), and further crimped once with a 2 kg roll. Twenty-four hours after the application, the adhesive strength (N/25 mm) was measured using a tensile tester under the conditions of a peel speed of 300 mm/min and a peel angle of 180°. Evaluation criteria are as follows.
(Evaluation criteria)
A: The adhesive strength is 15 N/25 mm or more. excellence.
B: The adhesive strength is 10 N/25 mm or more and less than 15 N/25 mm. Good.
C: Adhesive strength of 5 N/25 mm or more and less than 10 N/25 mm. Practical.
D: The adhesive strength is less than 5 N/25 mm. Not practical.
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000012
Figure JPOXMLDOC01-appb-T000013
Figure JPOXMLDOC01-appb-T000013
　表３に示すように本発明の粘着剤組成物（実施例）は、特定のウレタンプレポリマー（Ａ）を含んでいることで、粘着剤のバイオマス度および粘着剤における生分解性原料の使用比率が高くても、粘着特性を充分に満たし、さらに耐湿熱試験での汚染性に優れ（汚染性が低く）、加えて低温時の密着性にも優れていることが確認できた。
　特に、低温時の密着性については、ラクチド体（ａｘ’１－２）のなかでも、Ｌ－ラクチドおよびＤ－ラクチドを併用した場合、またはＤＬ－ラクチド、あるいはｍｅｓｏ－ラクチドを使用した場合に、より優れた密着性が得られることが確認できた。さらに、ｍｅｓｏ－ラクチドを使用した場合には、再剥離性についても特に優れた結果が得られることが確認できた。 As shown in Table 3, the pressure-sensitive adhesive composition (Example) of the present invention contains a specific urethane prepolymer (A), so that the biomass degree of the pressure-sensitive adhesive and the usage ratio of biodegradable raw materials in the pressure-sensitive adhesive It was confirmed that even if the viscosity is high, the adhesive property is sufficiently satisfied, the staining resistance is excellent in the moist heat resistance test (low staining resistance), and the adhesion at low temperatures is also excellent.
In particular, regarding the adhesion at low temperature, among the lactide forms (ax'1-2), when L-lactide and D-lactide are used in combination, or when DL-lactide or meso-lactide is used, It was confirmed that better adhesion was obtained. Furthermore, it was confirmed that when meso-lactide was used, particularly excellent removability was obtained.
　一方、比較例の粘着剤組成物では、所望とする粘着特性、耐湿熱試験での汚染性、低温時の密着性を得ることが困難であった。比較例１および２は、ポリオール（ａｘ）の調製において、乳酸単位を有する単量体（ａｘ’１）と、ラクトン単位および脂肪族ヒドロキシカルボン酸単位の少なくともいずれかを有する単量体（ａｘ’２）とを併用していない。また、比較例３は、ポリオール（ａｘ）の数平均分子量が本発明で規定する範囲外となる。
　以上のことから、本発明の粘着剤組成物は、特定のウレタンプレポリマー（Ａ）の使用によって、所望とする粘着特性、耐湿熱試験での汚染性、低温時の密着性を実現できることが分かる。
　また、本発明の粘着シートにおいて、基材として生分解性基材を使用した場合には、本発明の粘着剤組成物から形成される粘着剤層との組合せによって、粘着力などの特性をより容易に向上させることができる。例えば、実施例４４と、実施例８７および８８との対比から、生分解性基材の使用によって、粘着力が向上していることが分かる。 On the other hand, with the pressure-sensitive adhesive compositions of Comparative Examples, it was difficult to obtain the desired adhesive properties, resistance to staining in a moisture and heat resistance test, and adhesion at low temperatures. Comparative Examples 1 and 2 show that in the preparation of polyol (ax), a monomer (ax'1) having a lactic acid unit and a monomer (ax' 2) are not used together. Moreover, in Comparative Example 3, the number average molecular weight of the polyol (ax) is outside the range defined by the present invention.
From the above, it can be seen that the pressure-sensitive adhesive composition of the present invention can achieve desired adhesive properties, resistance to staining in a moisture and heat resistance test, and adhesion at low temperatures by using a specific urethane prepolymer (A). .
Further, in the pressure-sensitive adhesive sheet of the present invention, when a biodegradable base material is used as the base material, properties such as adhesive strength can be enhanced by combining with the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention. can be easily improved. For example, comparing Example 44 with Examples 87 and 88, it can be seen that the use of a biodegradable substrate improves adhesion.

Claims (10)

  1. 　数平均分子量が１，０００～４５，０００であるポリオール（ａｘ）、多官能ポリオール（ａｙ）（ただし、ポリオール（ａｘ）は除く）、およびポリイソシアネート（ａｚ）の反応物である、水酸基を有するウレタンプレポリマー（Ａ）を含み、
    　前記ポリオール（ａｘ）は、乳酸単位を有する単量体（ａｘ’１）と、ラクトン単位および脂肪族ヒドロキシカルボン酸単位の少なくともいずれかを有する単量体（ａｘ’２）（ただし、乳酸は除く）とを含む単量体混合物の共重合体であり、
    　前記水酸基を有するウレタンプレポリマー（Ａ）は、ガラス転移温度が－６０℃～－１０℃である、粘着剤組成物。     Polyol (ax) having a number average molecular weight of 1,000 to 45,000, polyfunctional polyol (ay) (excluding polyol (ax)), and polyisocyanate (az), having a hydroxyl group including a urethane prepolymer (A),
    The polyol (ax) is a monomer (ax'1) having a lactic acid unit and a monomer (ax'2) having at least one of a lactone unit and an aliphatic hydroxycarboxylic acid unit (excluding lactic acid). ) is a copolymer of a monomer mixture containing
    The pressure-sensitive adhesive composition, wherein the hydroxyl group-containing urethane prepolymer (A) has a glass transition temperature of -60°C to -10°C.
  2. 　上記ポリオール（ａｘ）の数平均分子量が１０，０００を超え、３５,０００以下である、請求項１に記載の粘着剤組成物。 The pressure-sensitive adhesive composition according to claim 1, wherein the polyol (ax) has a number average molecular weight of more than 10,000 and not more than 35,000.
  3. 　さらにイソシアネート硬化剤（Ｂ）を含む、請求項1に記載の粘着剤組成物。 The pressure-sensitive adhesive composition according to claim 1, further comprising an isocyanate curing agent (B).
  4. 　前記水酸基を有するウレタンプレポリマー（Ａ）は、重量平均分子量が１０，０００～２００，０００である、請求項１に記載の粘着剤組成物。 The pressure-sensitive adhesive composition according to claim 1, wherein the urethane prepolymer (A) having hydroxyl groups has a weight average molecular weight of 10,000 to 200,000.
  5. 　前記ポリオール（ａｘ）を構成する単量体混合物の全質量を基準として、前記単量体（ａｘ’１）と、前記単量体（ａｘ’２）との合計含有率が１０～９９．８質量％である、請求項１に記載の粘着剤組成物。 Based on the total mass of the monomer mixture constituting the polyol (ax), the total content of the monomer (ax'1) and the monomer (ax'2) is 10 to 99.8. The pressure-sensitive adhesive composition according to claim 1, which is % by mass.
  6. 　前記単量体（ａｘ’２）が、少なくともＭｅｓｏ－ラクチドを含む、請求項１に記載の粘着剤組成物。 The pressure-sensitive adhesive composition according to claim 1, wherein the monomer (ax'2) contains at least Meso-lactide.
  7. 　前記ポリオール（ａｘ）を構成する単量体混合物が、前記単量体（ａｘ’１）および前記単量体（ａｘ’２）と反応可能な単量体（ａｘ’３）をさらに含み、
    　前記単量体（ａｘ’３）が、２００～２,０００の数平均分子量を有するポリエステルポリオールを含む、請求項１に記載の粘着剤組成物。     The monomer mixture constituting the polyol (ax) further includes a monomer (ax'3) capable of reacting with the monomer (ax'1) and the monomer (ax'2),
    The pressure-sensitive adhesive composition according to claim 1, wherein the monomer (ax'3) comprises a polyester polyol having a number average molecular weight of 200-2,000.
  8. 　基材と、前記基材の少なくとも一方の面に設けられた、請求項１～７のいずれか１項に記載の粘着剤組成物から形成されてなる粘着剤層とを有する粘着シート。 A pressure-sensitive adhesive sheet having a base material and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of claims 1 to 7 provided on at least one surface of the base material.
  9. 　前記基材が、生分解性基材である、請求項８に記載の粘着シート。 The pressure-sensitive adhesive sheet according to claim 8, wherein the base material is a biodegradable base material.
  10. 　前記生分解性基材が、多糖類、ポリビニルアルコール樹脂、および生分解性ポリエステル樹脂からなる群から選択される少なくとも１種を含む、請求項９に記載の粘着シート。 The pressure-sensitive adhesive sheet according to claim 9, wherein the biodegradable base material contains at least one selected from the group consisting of polysaccharides, polyvinyl alcohol resins, and biodegradable polyester resins.
PCT/JP2022/017514 2021-04-14 2022-04-11 Adhesive composition and adhesive sheet WO2022220223A1 (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004231797A (en) * 2003-01-30 2004-08-19 Toyobo Co Ltd Biodegradable adhesive, varnish and laminate using the same
JP2010037463A (en) * 2008-08-06 2010-02-18 Nitto Denko Corp Polyester, polyester composition, adhesive composition, adhesive layer, and adhesive sheet
WO2014088023A1 (en) * 2012-12-05 2014-06-12 東洋紡株式会社 Copolymerized polyurethane resin and aqueous emulsion
JP2015218298A (en) * 2014-05-20 2015-12-07 東洋紡株式会社 Polylactic acid-based polyester resin, polylactic acid-based polyester resin water dispersion, and method for producing the polylactic acid-based polyester resin water dispersion

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004231797A (en) * 2003-01-30 2004-08-19 Toyobo Co Ltd Biodegradable adhesive, varnish and laminate using the same
JP2010037463A (en) * 2008-08-06 2010-02-18 Nitto Denko Corp Polyester, polyester composition, adhesive composition, adhesive layer, and adhesive sheet
WO2014088023A1 (en) * 2012-12-05 2014-06-12 東洋紡株式会社 Copolymerized polyurethane resin and aqueous emulsion
JP2015218298A (en) * 2014-05-20 2015-12-07 東洋紡株式会社 Polylactic acid-based polyester resin, polylactic acid-based polyester resin water dispersion, and method for producing the polylactic acid-based polyester resin water dispersion

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