WO2023276331A1 - Adhesive composition and adhesive sheet - Google Patents

Adhesive composition and adhesive sheet Download PDF

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Publication number
WO2023276331A1
WO2023276331A1 PCT/JP2022/013223 JP2022013223W WO2023276331A1 WO 2023276331 A1 WO2023276331 A1 WO 2023276331A1 JP 2022013223 W JP2022013223 W JP 2022013223W WO 2023276331 A1 WO2023276331 A1 WO 2023276331A1
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Prior art keywords
meth
acrylate
pressure
sensitive adhesive
group
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PCT/JP2022/013223
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French (fr)
Japanese (ja)
Inventor
辰矢 渡部
ちひろ 村田
直樹 竹内
Original Assignee
東洋インキＳｃホールディングス株式会社
トーヨーケム株式会社
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Publication of WO2023276331A1 publication Critical patent/WO2023276331A1/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
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • 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
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/08—Macromolecular additives
    • 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
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • 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
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/14—Homopolymers or copolymers of esters of esters containing halogen, nitrogen, sulfur or oxygen atoms in addition to the carboxy oxygen
    • 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

  • Embodiments of the present invention relate to adhesive compositions and adhesive sheets.
  • a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition is used in a wide range of fields for labeling or adhesive purposes because of its ease of handling.
  • a thinner pressure-sensitive adhesive layer of an adhesive sheet in various applications.
  • the adhesive force of the adhesive sheet generally decreases as the thickness of the adhesive layer decreases. Therefore, there is a strong demand for the development of a pressure-sensitive adhesive sheet having high adhesive strength even under thin film conditions.
  • Patent Document 1 discloses a pressure-sensitive adhesive sheet comprising a thin pressure-sensitive adhesive film containing a certain amount of a monomer having a carboxyl group and having a predetermined weight-average molecular weight and gel fraction.
  • Patent Document 2 discloses a thin-film pressure-sensitive adhesive sheet using a pressure-sensitive adhesive containing an acrylic copolymer containing n-butyl (meth)acrylate and a synthetic hydrocarbon-based tackifying resin.
  • An embodiment of the present invention is a pressure-sensitive adhesive that exhibits high adhesive strength to both high-polarity adherends and low-polarity adherends, even if it is a thin film, and is also excellent in holding power and curved surface adhesion. and provide adhesive sheets.
  • the copolymer (A) includes an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, and a (meth)acrylate (a2) having no reactive functional group and having an aliphatic cyclic structure.
  • the (meth)acrylate (a3) having a carboxyl group includes (meth)acrylate (a3-1) represented by general formula (1) and (meth)acrylate (a3-2) represented by general formula (2).
  • a pressure-sensitive adhesive composition comprising at least one of (In the formula, R 1 is a hydrogen atom or a methyl group, m is an integer of 2 to 10, and n is an integer of 1 to 5.) (In the formula, R 2 is a hydrogen atom or a methyl group, R 3 is a divalent hydrocarbon group, and p is an integer of 1 to 5.) [2] The pressure-sensitive adhesive composition according to [1] above, wherein the (meth)acrylate (a3) contains a (meth)acrylate (a3-2) represented by the general formula (2). [3] The adhesive composition according to [1] or [2] above, wherein the copolymer (A) has an acid value in the range of 0.1 to 24.0 mgKOH/g.
  • tackifying resin contains at least one selected from the group consisting of a rosin-based tackifying resin, a synthetic hydrocarbon-based tackifying resin, and a terpene-phenol-based tackifying resin.
  • the pressure-sensitive adhesive composition according to any one of [5].
  • Adhesive sheets can be provided.
  • the disclosure of the present application relates to the subject matter described in Japanese Patent Application No. 2021-107190 filed on June 29, 2022, and the entire disclosure content thereof is incorporated herein by reference.
  • (Meth)acrylic acid includes acrylic acid and methacrylic acid.
  • (Meth)acrylates include acrylates and methacrylates.
  • a monomer is a monomer having an ethylenically unsaturated double bond.
  • the adherend refers to the other party to which the pressure-sensitive adhesive sheet is attached.
  • the various components described herein may be used singly or in combination of two or more.
  • the adhesive composition that is one embodiment of the present invention contains a copolymer (A) and a curing agent (B).
  • the copolymer (A) includes an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, and a (meth)acrylate (a2) having no reactive functional group and having an aliphatic cyclic structure. ) and a monomer mixture containing a (meth)acrylate (a3) having a carboxyl group.
  • the (meth)acrylate (a3) having a carboxyl group includes (meth)acrylate (a3-1) represented by general formula (1) and (meth)acrylate (a3-2) represented by general formula (2).
  • R 1 is a hydrogen atom or a methyl group
  • m is an integer of 2 to 10
  • n is an integer of 1 to 5.
  • R 2 is a hydrogen atom or a methyl group
  • R 3 is a divalent hydrocarbon group
  • p is an integer of 1 to 5.
  • the polarity of the copolymer is lowered to Adhesion can be improved, and at the same time, compatibility with low-polarity tackifying resins can be improved.
  • a (meth)acrylate having a carboxyl group represented by general formula (1) or general formula (2) cohesion and flexibility can be imparted to the pressure-sensitive adhesive layer.
  • the copolymer (A) includes an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, and a (meth)acrylate (a2) having no reactive functional group and having an aliphatic cyclic structure. , and a (meth)acrylate (a3) having a carboxyl group, and optionally a (meth)acrylate (a4) having a hydroxyl group and other monomers as optional monomers, obtained by polymerizing a monomer mixture It is a copolymer.
  • the acid value of the copolymer (A) is preferably 0.1-24.0 mgKOH/g, more preferably 0.2-20.0 mgKOH/g.
  • the acid value of the copolymer (A) is 0.1 to 24.0 mgKOH/g, the cohesive force and flexibility of the adhesive layer can be imparted in a well-balanced manner, and the adhesive force, holding force, and curved surface It becomes easier to achieve both adhesiveness.
  • (Meth)acrylate (a1) is an alkyl (meth)acrylate having an alkyl group having 4 to 12 carbon atoms.
  • (Meth)acrylate (a1) is preferably 60% by mass or more, more preferably 70% by mass or more in 100% by mass of the monomer mixture based on the total mass of the monomer mixture (100% by mass). you can On the other hand, the content may be preferably 99% by mass or less, more preferably 98% by mass or less, still more preferably 95% by mass or less, and even more preferably 92% by mass or less.
  • the content of (meth)acrylate (a1) is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, based on 100% by mass of the monomer mixture.
  • (meth)acrylate (a1) is an alkyl group having 4 to 7 carbon atoms ( It preferably contains a meth)acrylate (a-1) and an alkyl (meth)acrylate (a-2) having an alkyl group with 8 to 12 carbon atoms.
  • alkyl (meth)acrylate (a-1) having an alkyl group having 4 to 7 carbon atoms examples include n-butyl (meth)acrylate, isobutyl (meth)acrylate, and n-hexyl (meth)acrylate. .
  • n-butyl (meth)acrylate is preferred from the viewpoint of achieving both adhesive strength and holding power.
  • alkyl (meth)acrylate (a-2) having an alkyl group having 8 to 12 carbon atoms examples include 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl ( meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate and the like.
  • 2-ethylhexyl (meth)acrylate is preferred from the viewpoint of achieving both adhesive strength and holding power.
  • (Meth)acrylate (a2) is a (meth)acrylate having no reactive functional group and having an alicyclic structure.
  • (Meth)acrylate (a2) is preferably used in a content of 1 to 20% by mass based on 100% by mass of the monomer mixture. The above content is more preferably 2 to 15% by mass.
  • (Meth)acrylate (a2) is characterized by not having a reactive functional group other than an acryloyl group.
  • reactive functional groups include carboxyl groups, hydroxyl groups, amino groups, and epoxy groups.
  • Aliphatic cyclic structures include, for example, a cyclohexyl group, a dicyclopentenyl group, a dicyclopentanyl group, and an isobornyl group. From the viewpoint of improving adhesive strength to low-polar adherends and compatibility with tackifying resins, it is preferable to have a dicyclopentenyl group, a dicyclopentanyl group, or an isobornyl group as the aliphatic cyclic structure.
  • (Meth)acrylates (a2) include, for example, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and isobornyl (meth)acrylate.
  • dicyclopentenyl (meth)acrylate and dicyclopentanyl having a three-dimensional aliphatic cyclic structure from the viewpoint of improving the adhesive strength to low-polar adherends and compatibility with tackifying resins (Meth)acrylates and isobornyl (meth)acrylates are preferred, and isobornyl (meth)acrylates are more preferred.
  • [(meth)acrylate (a3)] is a (meth)acrylate having a carboxyl group, and (meth)acrylate (a3-1) represented by general formula (1) and general formula (2) (meth) ) contains at least one of acrylates (a3-2). Among them, it is more preferable to contain (meth)acrylate (a3-2) represented by formula (2) from the viewpoint of obtaining adhesive strength to both high-polarity adherends and low-polarity adherends.
  • (Meth)acrylate (a3) is preferably used in a content of 0.1 to 10% by mass based on 100% by mass of the monomer mixture.
  • the above content is more preferably 0.2 to 8% by mass.
  • Metalacrylate (a3-1) is a (meth)acrylate represented by general formula (1).
  • R 1 is a hydrogen atom or a methyl group
  • m is an integer of 2 to 10
  • n is an integer of 1 to 5.
  • m represents an integer of 2-10.
  • m is an integer of 2 to 10 from the viewpoint of coexistence of adhesive strength, holding power and curved surface adhesiveness.
  • m is preferably an integer of 2-8, more preferably an integer of 3-5.
  • n represents an integer of 1-5.
  • n may be an integer of 1 to 5, preferably an integer of 2 to 4, from the viewpoint of compatibility between adhesive strength, holding power, and curved surface adhesiveness.
  • (Meth)acrylate (a3-1) may be one produced by a conventional method, or one appropriately selected from commercially available monomers.
  • (Meth)acrylates (a3-1) include, for example, ⁇ -hydroxyethyl acrylate and ⁇ -carboxypolycaprolactone mono(meth)acrylate. These monomers are commercially available, for example, under the trade names of " ⁇ -CEA” (manufactured by Daicel Ornex) and "Aronix M-5300" (manufactured by Toagosei Co., Ltd.), and these commercial products can be used.
  • ((meth) acrylate (a3-2)) (Meth)acrylate (a3-2) is a (meth)acrylate represented by general formula (2).
  • R 2 is a hydrogen atom or a methyl group
  • R 3 is a divalent hydrocarbon group
  • p is an integer of 1 to 5.
  • p represents an integer of 1-5.
  • p may be an integer of 1 to 5, preferably an integer of 1 to 3, from the viewpoint of compatibility between adhesive strength, holding power, and curved surface adhesiveness.
  • R3 represents a divalent hydrocarbon group.
  • hydrocarbon groups include saturated aliphatic hydrocarbon groups such as alkylene groups, saturated alicyclic hydrocarbon groups such as cycloalkylene groups, aromatic hydrocarbon groups such as phenylene groups, unsaturated aliphatic hydrocarbon groups, or Examples include unsaturated alicyclic hydrocarbon groups.
  • R 3 is preferably a saturated aliphatic hydrocarbon group from the viewpoint of improving adhesion by imparting flexibility.
  • R 3 is more preferably an alkylene group, more preferably an alkylene group having 1 to 4 carbon atoms.
  • (Meth)acrylate (a3-2) may be one produced by a conventional method, or one appropriately selected from commercially available monomers.
  • Examples of (meth)acrylates (a3-2) include 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl fumarate, and 2-(meth)acryloyloxyethyl phthalate. .
  • These monomers are, for example, "light ester HO-MS”, “HOA-MS (N)”, “light acrylate HOA-HH (N)” and “HOA-MPL (N)” (manufactured by Kyoeisha Chemical Co., Ltd.). It is marketed as a brand name, and these commercial products can be used.
  • (Meth)acrylate (a3) in addition to (meth)acrylate (a3-1) and (meth)acrylate (a3-2), (meth)acrylate (a3-3) having a carboxyl group other than these ) may be further contained.
  • Other (meth)acrylates (a3-3) having a carboxyl group include, for example, (meth)acrylic acid.
  • (Meth) acrylate (a3-1) and (meth) acrylate (a3-2) are the main chain of the acrylic polymer compared to (meth) acrylates having short carboxyl groups in side chains such as acrylic acid and the carboxyl group are far apart. Therefore, excellent adhesion to a highly polar adherend can be obtained without being disturbed by the large alicyclic structure derived from the (meth)acrylate (a2). In addition, since the side chain is not too long, it is possible to suppress interference with the adhesion of the (meth)acrylate (a2)-derived aliphatic cyclic structure to the low-polar adherend.
  • (meth)acrylate (a3) based on the total mass of (meth)acrylate (a3) (100% by mass), other carboxyl groups other than (meth)acrylate (a3-1) and (meth)acrylate (a3-2)
  • the content of (meth)acrylate (a3-3) may be 43% by mass or less.
  • (meth)acrylate (a3) includes (meth)acrylate (a3-1) and (meth)acrylate (a3-2), and (meth)acrylate (a3-3) having a carboxyl group. and the content of (meth)acrylate (a3-3) in 100% by mass of (meth)acrylate (a3) may be greater than 0.1% by mass and 43% by mass or less.
  • (meth)acrylate (a3) contains only (meth)acrylate (a3-1) and (meth)acrylate (a3-2), and (meth)acrylate (a3) having a carboxyl group -3) is not included. That is, the content of (meth)acrylate (a3-3) may be 0% by mass.
  • the content of the (meth)acrylate (a3) component other than (meth)acrylate (a3-1) and (meth)acrylate (a3-2) is preferably as low as possible.
  • the content of the above components is preferably 40% by mass or less, more preferably 30% by mass or less, based on the total 100% by mass of the (meth)acrylate (a3), and 20% by mass. % or less.
  • the above content may be 0% by mass. When the above content is adjusted to 40% by mass or less, excellent adhesion to both highly polar adherends and low polar adherends can be easily obtained, which is preferable.
  • [(meth)acrylate (a4)] is a (meth)acrylate having a hydroxyl group.
  • the monomer mixture may further contain a (meth)acrylate (a4) having a hydroxyl group.
  • Inclusion of a (meth)acrylate (a4) having a hydroxyl group is preferable because cohesive force can be easily expressed and excellent holding power and curved surface adhesiveness can be easily obtained.
  • the (meth)acrylate (a4) having a hydroxyl group is preferably used in a content of 0.05 to 3% by mass based on 100% by mass of the monomer mixture. More preferably, the content is 0.1 to 2% by mass.
  • the hydroxyl group-containing (meth)acrylate (a4) is used at a content of 0.05 to 3% by mass, the cohesive strength of the pressure-sensitive adhesive layer is improved, making it easier to improve the holding power and adhesion to curved surfaces.
  • (Meth)acrylates (a4) having a hydroxyl group include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, Hydroxyalkyl (meth)acrylates such as acid 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate, and polyethylene glycol mono (meth)acrylates, polypropylene glycol mono(meth)acrylates, and glycol mono(meth)acrylates such as 1,4-cyclohexanedimethanol mono(meth)acrylate, and the like.
  • 2-hydroxyethyl (meth)acrylate is preferred.
  • Other monomers include an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, a (meth)acrylate (a2) having an aliphatic cyclic structure without a reactive functional group, and a carboxyl group. and (meth)acrylates other than (a3) having a hydroxyl group (meth)acrylate (a4) and monomers other than (meth)acrylates.
  • Other monomers can be used as long as they do not impair the adhesive strength, holding power, and curved surface adhesiveness of the adhesive. Specific examples thereof include alkyl (meth)acrylates having an alkyl group other than (meth)acrylate (a1). Other specific examples include monomers having an amide bond, monomers having an epoxy group, monomers having an amino group, monomers having an aromatic ring, monomers having an alkoxy(poly)alkylene oxide, and other vinyl monomers.
  • Alkyl (meth)acrylate monomers other than the (meth)acrylate (a1) include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-octadecyl ( meth)acrylate, and isooctadecyl (meth)acrylate, and the like.
  • the content thereof is preferably 0.1 to 20% by mass in 100% by mass of the monomer mixture.
  • Monomers having an amide bond include, for example, (meth)acrylamide, N-methylacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-dimethylaminopropyl(meth)acrylamide, (Meth)acrylamide compounds such as diacetoneacrylamide and N-(butoxymethyl)acrylamide, and heterocyclic ring-containing compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, and acryloylmorpholine.
  • Examples of monomers having an epoxy group include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and the like.
  • Monomers having an amino group are, for example, monoalkylamino (meth)acrylates such as monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, monomethylaminopropyl (meth)acrylate, and monoethylaminopropyl (meth)acrylate. ) acrylates and the like.
  • a monomer having an amide bond, a monomer having an epoxy group, and a monomer having an amino group are used, their content is preferably 0.1 to 1% by mass in 100% by mass of the monomer mixture.
  • aromatic ring-containing monomers examples include phenoxyethyl acrylate, benzyl acrylate, phenoxydiethylene glycol (meth)acrylate, and ethylene oxide-modified nonylphenol (meth)acrylate.
  • a monomer having an aromatic ring When a monomer having an aromatic ring is used, its content is preferably 0.1 to 10% by mass in 100% by mass of the monomer mixture.
  • Monomers with alkoxy(poly)alkylene oxides are, for example, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-phenoxyethyl acrylate, methoxypolyethyleneglycol (meth)acrylate, ethoxypolyethyleneglycol (meth)acrylate, methoxypolypropyleneglycol. (Meth)acrylate, ethoxypolypropyleneglycol (meth)acrylate, phenoxypolyethyleneglycol (meth)acrylate, phenoxypolypropyleneglycol (meth)acrylate and the like.
  • a monomer having an alkoxy(poly)alkylene oxide When a monomer having an alkoxy(poly)alkylene oxide is used, its content is preferably 0.1 to 10% by mass based on 100% by mass of the monomer mixture.
  • vinyl monomers include, but are not limited to, vinyl acetate, acrylonitrile, and the like. When other vinyl monomers are used, their content is preferably 0.1 to 10% by mass in 100% by mass of the monomer mixture.
  • the copolymer (A) can be obtained, for example, by adding a polymerization initiator to a monomer mixture and carrying out solution polymerization.
  • Solvents used in the solution polymerization include, for example, methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, hexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, and isopropanol. is preferred, and ethyl acetate is more preferred.
  • a polymerization initiator it is preferable to add about 0.001 to 1 part by mass of a polymerization initiator to 100 parts by mass of the monomer mixture.
  • the polymerization can be carried out at a temperature of about 50° C. to 90° C. for 6 hours to 20 hours under nitrogen stream.
  • the weight average molecular weight of the copolymer can be appropriately adjusted by using a chain transfer agent during the polymerization.
  • the weight average molecular weight (Mw) of the copolymer (A) is preferably 300,000 to 1,500,000, more preferably 500,000 to 1,300,000, and even more preferably 600,000 to 1,200,000.
  • Mw is adjusted in the range of 300,000 to 1,500,000, it becomes easy to achieve compatibility between adhesive strength, holding power, and curved surface adhesiveness.
  • the weight average molecular weight described in this specification is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).
  • Chain transfer agents are, for example, n-dodecylmercaptan, mercaptoisobutyl alcohol, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto-1-propanol, glycidylmercaptan, ⁇ -methyl Styrene dimer, carbon tetrachloride, chloroform, hydroquinone, and the like. About 0.01 to 1 part by mass of the chain transfer agent can be used with respect to 100 parts by mass of the monomer mixture.
  • Polymerization initiators are generally azo compounds and organic peroxides.
  • Azo compounds include, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), 1,1′-azobis(cyclohexane 1-carbonitrile), 2, 2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 4,4′-azobis(4-cyanovaleric acid), 2,2′-azobis(2-hydroxymethylpropionitrile), and 2,2′-azobis(2-(2-imidazolin-2-yl) propane) and the like.
  • Organic peroxides include, for example, benzoyl peroxide, t-butylperbenzoate, cumene hydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, Carbonate, t-butylperoxyneodecanoate, t-butylperoxybivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionylperoxide, diacetylperoxide and the like.
  • the adhesive composition further contains a curing agent (B).
  • a curing agent By including a curing agent, cohesive force can be improved, and holding power and curved surface adhesion can be improved to a practical level.
  • Curing agents (B) include, for example, isocyanate curing agents, epoxy curing agents, aziridine curing agents, metal chelate curing agents, amine curing agents, and amino resin curing agents. Among these, at least one selected from the group consisting of isocyanate-based curing agents, epoxy-based curing agents, and metal chelate-based curing agents can be used in order to obtain better holding power and curved surface adhesion. preferable.
  • Isocyanate-based curing agents include, for example, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate.
  • Epoxy curing agents include, for example, bisphenol A-epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diol.
  • glycidyl ether trimethylolpropane triglycidyl ether, diglycidylaniline, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane , and N,N,N',N'-tetraglycidylaminophenylmethane.
  • Metal chelate-based curing agents are, for example, coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium, and acetylacetone or ethyl acetoacetate. etc.
  • the content of the isocyanate-based curing agent in the curing agent (B) is preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the acrylic copolymer.
  • the content of the epoxy curing agent is preferably 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the acrylic copolymer.
  • the content of the metal chelate curing agent is preferably 0.1 to 2 parts by mass.
  • the adhesive composition may further comprise a tackifying resin.
  • tackifying resins include rosin-based tackifying resins, synthetic hydrocarbon-based tackifying resins, terpene-based tackifying resins, and terpene-phenol-based tackifying resins. It preferably contains at least one selected from the group consisting of hydrocarbon-based tackifying resins and terpene-phenol-based tackifying resins.
  • the adhesive force can be further improved.
  • a rosin-based tackifying resin and a synthetic hydrocarbon-based tackifying resin in combination it is easier to achieve both compatibility and adhesive strength to high-polarity adherends and low-polarity adherends. preferred to become
  • Rosin-based tackifying resins include rosin esters obtained by esterifying unmodified rosins such as gum rosin, tall oil rosin, and wood rosin with alcohol; Disproportionated rosin esters obtained by further esterifying these modified rosins with alcohol, modified rosin esters such as polymerized rosin esters and hydrogenated rosin esters, and rosin phenol obtained by adding phenol to the unmodified rosin are preferred. Among these, rosin esters and modified rosin esters are preferred because they further improve adhesive strength and transparency. In the rosin ester and the modified rosin ester, some hydroxyl groups of the alcohol used for esterification may remain unreacted.
  • alcohols used for esterification include monofunctional alcohols such as methanol, bifunctional alcohols such as ethylene glycol, trifunctional alcohols such as glycerin, and tetrafunctional alcohols such as pentaerythritol. Considering the compatibility with the acrylic copolymer, tri- or less functional alcohols are preferred.
  • Synthetic hydrocarbon-based tackifying resins include, for example, coumarone-based resins, coumarone-indene-based resins, styrene-based resins, xylene-based resins, phenol-based resins, and petroleum-based resins.
  • styrene-based resins are preferable because they have good compatibility with acrylic polymers and can further improve adhesive performance.
  • the tackifying resin used in the pressure-sensitive adhesive composition includes a rosin-based tackifying resin and a synthetic hydrocarbon-based resin from the viewpoint of achieving both high-polarity adherend and low-polarity adherend strength.
  • Tackifying resins are preferred.
  • Synthetic hydrocarbon-based tackifying resins are more preferred.
  • the softening point of the tackifying resin is preferably 80°C or higher, more preferably 90°C or higher. Moreover, the upper limit of the softening point is preferably 170°C, more preferably 160°C, and even more preferably 155°C. When the softening point of the tackifier resin is 80 to 170° C., it becomes easy to achieve both high levels of adhesive strength and holding power.
  • the softening point is the softening temperature measured according to the dry bulb method specified in JISK5902.
  • the tackifying resin is preferably used in a proportion of 10 to 50 parts by mass, more preferably 15 to 40 parts by mass, per 100 parts by mass of the copolymer (A).
  • the tackifying resin is used in a proportion of 10 to 50 parts by mass, it is possible to more easily achieve both adhesive strength, cohesive strength, and curved surface adhesiveness.
  • the pressure-sensitive adhesive composition can further include a polyolefin.
  • the pressure-sensitive adhesive composition contains polyolefin, the adhesive strength to low-polar adherends made of polyolefin can be improved.
  • Chlorinated polyolefins include, for example, chlorinated polypropylene, acid-modified chlorinated polypropylene, acrylic-modified chlorinated polypropylene, chlorinated polyethylene, and chlorinated ethylene-vinyl acetate copolymer.
  • chlorinated polypropylene chlorinated polypropylene, acid-modified chlorinated polypropylene, and acrylic-modified chlorinated polypropylene are preferable from the viewpoint of excellent solubility and high adhesion to polyolefin adherends.
  • Chlorinated polypropylene is more preferred.
  • the chlorine content in the chlorinated polyolefin is preferably 20% or more and 45% or less, more preferably 28% or more and 45% or less, from the viewpoint that the effect of improving the adhesive strength to low-polar polyolefin adherends is high.
  • Non-chlorinated polyolefins include, for example, polyethylene, polypropylene, ⁇ -olefin-propylene copolymer, ethylene-vinyl acetate copolymer, polybutene, maleated polypropylene, maleated polybutene, polybutadiene and its hydrides, polyisoprene and its hydrides, maleated polybutadiene, maleated polyisoprene, polybutadiene polyol and its hydride, polyisoprene polyol and its hydride, process oil and lubricating oils such as liquid paraffin, and the like.
  • ⁇ -olefin-polypropylene copolymer, maleated polypropylene, polybutene, and lubricating oil are preferable from the viewpoint of excellent solubility and high adhesion to polyolefin adherends.
  • lubricating oil paraffinic lubricating oil, naphthenic lubricating oil and the like are preferable.
  • chlorinated polyolefin is preferable from the viewpoint of excellent solubility and high adhesive strength to polyolefin adherends. Among them, chlorinated polypropylene is more preferable.
  • the polyolefin is preferably used in a proportion of 0.01 to 10 parts by mass, more preferably 0.02 to 5 parts by mass, per 100 parts by mass of the copolymer (A).
  • polyolefin is used in a proportion of 0.01 to 10 parts by mass, it is possible to more easily achieve both adhesive strength, cohesive strength, and curved surface adhesion to low-polar adherends.
  • the pressure-sensitive adhesive composition further contains, as optional components, a flame retardant auxiliary, a heat stabilizer, a weather stabilizer, an anti-aging agent, an ultraviolet absorber, a leveling agent, an antistatic agent, a slip agent, an anti-blocking agent, and an anti-fogging agent. , lubricants, dyes, waxes, emulsions, magnetics, and dielectric property modifiers.
  • Adhesive Sheet Another embodiment of the present invention relates to an adhesive sheet provided with an adhesive layer formed from the adhesive composition of the above embodiment.
  • the pressure-sensitive adhesive sheet preferably includes a substrate and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (hereinafter sometimes referred to as pressure-sensitive adhesive) of the above-described embodiment.
  • a double-sided pressure-sensitive adhesive sheet having pressure-sensitive adhesive layers on both sides of a core material, or a cast pressure-sensitive adhesive sheet having only a pressure-sensitive adhesive layer without a substrate and a core material are preferable.
  • the pressure-sensitive adhesive layer can be formed by applying a pressure-sensitive adhesive onto a substrate and drying it.
  • it can be formed by coating a release sheet with a pressure-sensitive adhesive, drying it to form a pressure-sensitive adhesive layer, and then laminating the substrate.
  • a peelable sheet is usually adhered to the surface of the pressure-sensitive adhesive layer that does not come into contact with the base material, and the adhesive layer is stored.
  • the viscosity can be adjusted by adding the solvent previously described in the solution polymerization.
  • the base material is preferably cellophane, plastic, rubber, foam, fabric, rubberized fabric, resin-impregnated fabric, glass, wood, or the like.
  • the shape of the base material can be selected from a plate shape and a film shape, but the film shape is preferable because it is easy to handle.
  • the base material one type can be used alone, or a laminate in which two or more types are combined can be used.
  • the above plastics include, for example, polyvinyl alcohol, triacetyl cellulose, polypropylene, polyethylene, polycycloolefins, polyolefins such as ethylene-vinyl acetate copolymer, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polycarbonates, polynorbornene, polyarylate, polyacryl, polyphenylene sulfide, polystyrene, polyamide, polyimide, and the like.
  • the method of applying the adhesive is not particularly limited. mentioned. It is preferable to carry out a drying process during coating.
  • the drying device is not particularly limited, and examples thereof include hot air dryers, infrared heaters, decompression methods, and the like.
  • the drying temperature is usually about 60 to 160°C.
  • the thickness of the adhesive layer is preferably 1 to 20 ⁇ m, more preferably 1 to 15 ⁇ m, even more preferably 1 to 10 ⁇ m.
  • the pressure-sensitive adhesive composition of the above embodiment can obtain excellent properties in terms of all of adhesive strength, holding power, and curved surface adhesion, even when the thickness is as thin as 1 to 20 ⁇ m.
  • the pressure-sensitive adhesive sheet which is one embodiment of the present invention, can be used for various purposes regardless of the adherend.
  • the adherend can be a variety of adherends ranging from highly polar to less polar, such as plastics such as polyolefins, glass, cardboard, and metals.
  • the weight average molecular weight (Mw) and acid value of the copolymer were measured by the following methods. ⁇ Measurement of weight average molecular weight (Mw)> GPC was used to measure the weight average molecular weight.
  • GPC is liquid chromatography for separating and quantifying a substance dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size, and the weight average molecular weight was determined in terms of polystyrene.
  • Apparatus name Shimadzu Corporation, LC-GPC system "Prominence" Column: 4 columns of GMHXL manufactured by Tosoh Corporation and 1 column of HXL-H manufactured by Tosoh Corporation were connected in series.
  • Mobile phase solvent Tetrahydrofuran Flow rate: 1.0 ml/min Column temperature: 40°C
  • Acid value ⁇ (5.61 ⁇ a ⁇ F) / S ⁇ / (non-volatile content / 100)
  • S Sample collection amount
  • a consumption of 0.1N-alcoholic potassium hydroxide solution
  • F Factor of 0.1N-alcoholic potassium hydroxide solution
  • reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen inlet tube (hereinafter simply referred to as "reaction vessel") was charged with 20 parts of 2-ethylhexyl acrylate, n- 70.8 parts of butyl acrylate, 5 parts of isobornyl acrylate, 0.2 parts of 2-hydroxyethyl acrylate, ⁇ -carboxypolycaprolactone monoacrylate (manufactured by Toagosei Co., Ltd., Aronix M-5300) 2 parts, 2-acryloyloxyethyl 2 parts of succinic acid (HOA-MS (N), manufactured by Kyoeisha Chemical Co., Ltd.), 70 parts of ethyl acetate, and 0.015 part of 2,2'-azobisisobutyronitrile were charged respectively.
  • reaction vessel was charged with 20 parts of 2-ethylhexyl acrylate, n- 70.8
  • Copolymers (A-2 to 11, A'-1 to 4) were prepared in the same manner as for copolymer (A-1), except that the types and amounts of monomers were changed as shown in Table 1. got
  • reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen inlet tube (hereinafter simply referred to as "reaction vessel") was charged with 20 parts of 2-ethylhexyl acrylate, n- 70.8 parts of butyl acrylate, 5 parts of isobornyl acrylate, 0.2 parts of 2-hydroxyethyl acrylate, 4 parts of 2-acryloyloxyethyl succinic acid (manufactured by Kyoeisha Chemical Co., Ltd., HOA-MS (N)), 35 parts of ethyl acetate 35 parts of methyl ethyl ketone and 0.015 part of 2,2'-azobisisobutyronitrile were charged.
  • the resulting pressure-sensitive adhesive composition was coated on a release sheet (made of polyethylene terephthalate) having a thickness of 38 ⁇ m using a comma coater so that the thickness after drying was 10 ⁇ m, and the composition was heated at 100° C. for 2 minutes. An adhesive layer was formed by drying. Next, a 25 ⁇ m thick substrate (made of polyethylene terephthalate, hereinafter referred to as a PET sheet) is attached to this adhesive layer, and aged for 1 week at a temperature of 23 ° C. and a relative humidity of 50%. A pressure-sensitive adhesive sheet having a structure of "adhesive sheet/adhesive layer/PET sheet" was obtained.
  • Examples 2 to 25, Comparative Examples 1 to 4 The adhesive compositions and adhesive sheets of Examples 2 to 25 and Comparative Examples 1 to 4 were obtained in the same manner as in Example 1, except that the composition and blending amount were changed as shown in Tables 2 and 3. .
  • Adhesive Sheet was evaluated by the following methods. Tables 2 and 3 show the results.
  • (1) Adhesive strength The obtained adhesive sheet was prepared in a size of 25 mm in width and 100 mm in length. In an atmosphere of 23° C. and a relative humidity of 50%, the peelable sheet was peeled off from the adhesive sheet, and the exposed adhesive layer was attached to a stainless steel (SUS) plate and crimped once with a 2 kg roll. After being left for 24 hours, the adhesive strength was measured in a 180° peel test in which a tensile tester was used to peel off at a speed of 300 mm/min in the direction of 180°, and evaluation was performed based on the following evaluation criteria.
  • SUS stainless steel
  • Adhesive strength is 12 N or more
  • very good B Adhesive strength is 10 N or more and less than 12 N
  • good C Adhesive strength is 6 N or more and less than 10 N
  • practical D Adhesive strength is less than 6 N
  • Impractical Adhesive strength was measured with respect to a polypropylene (PP) plate in the same manner as described above, and evaluation was performed based on the following evaluation criteria.
  • Adhesive strength is 12 N or more, very good B: Adhesive strength is 10 N or more and less than 12 N, good C: Adhesive strength is 6 N or more and less than 10 N, practical D: Adhesive strength is less than 6 N, impractical
  • the obtained pressure-sensitive adhesive sheet was cut into a size of 25 mm in width and 100 mm in length to obtain a sample. Then, in an atmosphere of 23° C. and a relative humidity of 50%, the release sheet was peeled off from the sample according to JIS Z 0237, and the exposed 25 mm wide and 25 mm long tip portion of the adhesive layer was attached to a polished stainless steel (SUS) plate. After pressing once with a 2 kg roll, a load of 1 kg was applied in an atmosphere of 70° C. and held for 70,000 seconds. The evaluation indicates the number of seconds when the sample dropped from the SUS plate.
  • SUS polished stainless steel
  • the pressure-sensitive adhesive sheet according to one embodiment of the present invention has excellent adhesion to both a stainless steel plate, which is a high-polarity adherend, and a polypropylene plate, which is a low-polarity adherend. It was confirmed that the strength and curved surface adhesiveness were also excellent. On the other hand, the pressure-sensitive adhesive sheets of the comparative examples were found to be unsatisfactory in any of the evaluation items, indicating that there is a problem in practical use and that they are not practical.

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Abstract

Provided is an adhesive composition including a copolymer (A) and a curing agent (B), the copolymer (A) being formed from a monomer mixture containing an alkyl (meth)acrylate (a1) that has a C4-12 alkyl group, a (meth)acrylate (a2) that has an aliphatic cyclic structure and does not have reactive functional groups, and a (meth)acrylate (a3) that has a carboxyl group, and the (meth)acrylate (a3) that has a carboxyl group including at least one of a (meth)acrylate (a3-1) represented by general formula (1) and a (meth)acrylate (a3-2) represented by general formula (2).

Description

粘着剤組成物及び粘着シートAdhesive composition and adhesive sheet
　本発明の実施形態は、粘着剤組成物及び粘着シートに関する。 Embodiments of the present invention relate to adhesive compositions and adhesive sheets.
　粘着剤組成物から形成した粘着剤層を有する粘着シートは、取り扱いが容易であることから、幅広い分野において、ラベル又は接着の用途で使用されている。近年、コストダウン及び環境負荷軽減、並びに電子デバイスの軽量薄膜化の観点から、様々な用途において接着シートの粘着剤層の薄膜化が求められている。
　しかしながら、粘着シートの粘着力は、一般的に、粘着剤層の膜厚の減少に伴って低下する。このため、薄膜条件であっても高い粘着力を有する粘着シートの開発が強く望まれている。さらに、様々な用途で粘着シートを使用するためには、ステンレス板のような高極性被着体、及びポリオレフィンのような低極性被着体のどちらに対しても強い粘着力を示し、かつ保持力、及び曲面接着性にも優れている必要がある。
　特許文献１には、カルボキシル基を有する単量体を一定量含み、重量平均分子量とゲル分率とを既定した薄膜の粘着膜を備える粘着シートが開示されている。
　特許文献２には、ｎ－ブチル（メタ）アクリレートを含むアクリル共重合体と合成炭化水素系粘着付与樹脂とを含む粘着剤を用いた薄膜の粘着シートが開示されている。 A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition is used in a wide range of fields for labeling or adhesive purposes because of its ease of handling. In recent years, from the viewpoint of cost reduction, reduction of environmental load, and reduction in weight and thickness of electronic devices, there has been a demand for a thinner pressure-sensitive adhesive layer of an adhesive sheet in various applications.
However, the adhesive force of the adhesive sheet generally decreases as the thickness of the adhesive layer decreases. Therefore, there is a strong demand for the development of a pressure-sensitive adhesive sheet having high adhesive strength even under thin film conditions. Furthermore, in order to use the adhesive sheet in various applications, it is necessary to exhibit and retain strong adhesion to both high-polarity adherends such as stainless steel plates and low-polarity adherends such as polyolefins. It should also have good strength and curved surface adhesion.
Patent Document 1 discloses a pressure-sensitive adhesive sheet comprising a thin pressure-sensitive adhesive film containing a certain amount of a monomer having a carboxyl group and having a predetermined weight-average molecular weight and gel fraction.
Patent Document 2 discloses a thin-film pressure-sensitive adhesive sheet using a pressure-sensitive adhesive containing an acrylic copolymer containing n-butyl (meth)acrylate and a synthetic hydrocarbon-based tackifying resin.
特開２０１９－７７８２０号公報JP 2019-77820 A 国際公開第２０２０／２７１８０号WO2020/27180
　しかしながら、これら従来の粘着シートでは、ステンレス板などの高極性被着体に対する粘着力は優れるものの、ポリオレフィンのような低極性被着体に対する粘着力が充分ではない。特に、薄膜条件の場合において、高極性被着体及び低極性被着体のいずれに対しても高い粘着力を示すことは困難であり、加えて保持力と曲面適性についても満足することはできていないのが現状である。 However, although these conventional pressure-sensitive adhesive sheets have excellent adhesion to high-polarity adherends such as stainless steel plates, they do not have sufficient adhesion to low-polarity adherends such as polyolefin. In particular, in the case of thin film conditions, it is difficult to exhibit high adhesive strength to both high-polarity adherends and low-polarity adherends. The current situation is that they are not.
　本発明の実施形態は、薄膜であっても、高極性被着体及び低極性被着体のいずれに対しても、高い粘着力を示し、さらに保持力及び曲面接着性にも優れる、粘着剤及び粘着シートを提供する。 An embodiment of the present invention is a pressure-sensitive adhesive that exhibits high adhesive strength to both high-polarity adherends and low-polarity adherends, even if it is a thin film, and is also excellent in holding power and curved surface adhesion. and provide adhesive sheets.
　本発明の実施形態は、以下に関する。但し、本発明は、以下の実施形態に限定されず、様々な実施形態を含む。
　[１]共重合体（Ａ）と硬化剤（Ｂ）とを含む粘着剤組成物であって、
　上記共重合体（Ａ）は、炭素数４～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ１）、反応性官能基を有さず、脂肪族環式構造を有する（メタ）アクリレート（ａ２）、及びカルボキシル基を有する（メタ）アクリレート（ａ３）を含有するモノマー混合物の共重合体であり、
　上記カルボキシル基を有する（メタ）アクリレート（ａ３）は、一般式（１）で表される（メタ）アクリレート（ａ３－１）及び一般式（２）で表される（メタ）アクリレート（ａ３－２）の少なくともいずれかを含む、粘着剤組成物。
Figure JPOXMLDOC01-appb-C000003
 （式中、Ｒ１は水素原子又はメチル基、ｍは２～１０の整数、ｎは１～５の整数を示す。）
Figure JPOXMLDOC01-appb-C000004
 （式中、Ｒ２は水素原子又はメチル基、Ｒ３は２価の炭化水素基、ｐは１～５の整数を示す。）
　[２]上記（メタ）アクリレート（ａ３）は、一般式（２）で表される（メタ）アクリレート（ａ３－２）を含む、上記［１］に記載の粘着剤組成物。
　[３]上記共重合体（Ａ）は、酸価が０．１～２４．０ｍｇＫＯＨ／ｇの範囲にある、上記［１］又は［２］に記載の粘着剤組成物。
　[４]上記モノマー混合物は、さらに水酸基を有する（メタ）アクリレート（ａ４）を含有する、上記［１］～［３］のいずれか１項に記載の粘着剤組成物。
　[５]上記硬化剤（Ｂ）は、イソシアネート系硬化剤、エポキシ系硬化剤及び金属キレート系硬化剤からなる群より選ばれる少なくとも１種を含む、上記［１］～［４］のいずれか１項に記載の粘着剤組成物。
　[６]さらに粘着付与樹脂を含み、上記粘着付与樹脂は、ロジン系粘着付与樹脂、合成炭化水素系粘着付与樹脂及びテルペンフェノール系粘着付与樹脂からなる群より選ばれる少なくとも１種を含む、上記［１］～［５］のいずれか１項に記載の粘着剤組成物。
　［７］さらにポリオレフィンを含む、上記［１］～［６］のいずれか１項に記載の粘着剤組成物。
　［８］上記アルキル（メタ）アクリレート（ａ１）の含有量は、上記モノマー混合物の全質量を基準として、７０～９９質量％である、上記［１］～［７］のいずれか１項に記載の粘着剤組成物。
　［９］上記カルボキシル基を有する（メタ）アクリレート（ａ３）において、上記（メタ）アクリレート（ａ３－１）、及び上記（メタ）アクリレート（ａ３－２）以外の、その他カルボキシル基を有する（メタ）アクリレート（ａ３－３）の含有量は、上記カルボキシル基を有する（メタ）アクリレート（ａ３）の全質量を基準として、４３質量％以下である、上記［１］～［８］のいずれか１項に記載の粘着剤組成物。
　［１０］上記［１］～［９］のいずれか１項に記載の粘着剤組成物から形成してなる粘着剤層を備えた、粘着シート。
　［１１］上記粘着剤層は、厚みが１～２０μｍである、上記［１０］に記載の粘着シート。 Embodiments of the invention relate to the following. However, the present invention is not limited to the following embodiments, and includes various embodiments.
[1] A pressure-sensitive adhesive composition containing a copolymer (A) and a curing agent (B),
The copolymer (A) includes an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, and a (meth)acrylate (a2) having no reactive functional group and having an aliphatic cyclic structure. ), and a copolymer of a monomer mixture containing a (meth)acrylate (a3) having a carboxyl group,
The (meth)acrylate (a3) having a carboxyl group includes (meth)acrylate (a3-1) represented by general formula (1) and (meth)acrylate (a3-2) represented by general formula (2). ), a pressure-sensitive adhesive composition comprising at least one of
Figure JPOXMLDOC01-appb-C000003
 (In the formula, R 1 is a hydrogen atom or a methyl group, m is an integer of 2 to 10, and n is an integer of 1 to 5.)
Figure JPOXMLDOC01-appb-C000004
 (In the formula, R 2 is a hydrogen atom or a methyl group, R 3 is a divalent hydrocarbon group, and p is an integer of 1 to 5.)
[2] The pressure-sensitive adhesive composition according to [1] above, wherein the (meth)acrylate (a3) contains a (meth)acrylate (a3-2) represented by the general formula (2).
[3] The adhesive composition according to [1] or [2] above, wherein the copolymer (A) has an acid value in the range of 0.1 to 24.0 mgKOH/g.
[4] The adhesive composition according to any one of [1] to [3] above, wherein the monomer mixture further contains a (meth)acrylate (a4) having a hydroxyl group.
[5] Any one of [1] to [4] above, wherein the curing agent (B) contains at least one selected from the group consisting of an isocyanate curing agent, an epoxy curing agent, and a metal chelate curing agent. The pressure-sensitive adhesive composition according to the item.
[6] It further contains a tackifying resin, and the tackifying resin contains at least one selected from the group consisting of a rosin-based tackifying resin, a synthetic hydrocarbon-based tackifying resin, and a terpene-phenol-based tackifying resin. 1] The pressure-sensitive adhesive composition according to any one of [5].
[7] The pressure-sensitive adhesive composition according to any one of [1] to [6] above, further comprising polyolefin.
[8] Any one of [1] to [7] above, wherein the content of the alkyl (meth)acrylate (a1) is 70 to 99% by mass based on the total mass of the monomer mixture. adhesive composition.
[9] In the (meth)acrylate (a3) having a carboxyl group, (meth)acrylates other than the (meth)acrylate (a3-1) and the (meth)acrylate (a3-2) having a carboxyl group Any one of the above [1] to [8], wherein the content of the acrylate (a3-3) is 43% by mass or less based on the total mass of the (meth)acrylate (a3) having a carboxyl group. The pressure-sensitive adhesive composition according to .
[10] A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of [1] to [9] above.
[11] The pressure-sensitive adhesive sheet according to [10] above, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 20 μm.
　本発明によれば、薄膜であっても、高極性被着体及び低極性被着体のいずれに対しても高い粘着力を示し、さらに、保持力及び曲面接着性にも優れる、粘着剤及び粘着シートを提供できる。
　本願の開示は、２０２２年６月２９日に出願された特願２０２１－１０７１９０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, even if it is a thin film, it exhibits high adhesive strength to both high-polarity adherends and low-polarity adherends, and is also excellent in holding power and curved surface adhesion. Adhesive sheets can be provided.
The disclosure of the present application relates to the subject matter described in Japanese Patent Application No. 2021-107190 filed on June 29, 2022, and the entire disclosure content thereof is incorporated herein by reference.
　本発明について詳細に説明する前に、用語を定義する。先ず、シート、フィルム及びテープは同義語である。
　（メタ）アクリル酸は、アクリル酸及びメタクリル酸を含む。（メタ）アクリレートは、アクリレート及びメタクリレートを含む。モノマーは、エチレン性不飽和二重結合を有する単量体である。
　被着体は、粘着シートを貼り付ける相手方をいう。
　本明細書では、炭素数４～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ１）、反応性官能基を有さず、脂肪族環式構造を有する（メタ）アクリレート（ａ２）、及びカルボキシル基を有する（メタ）アクリレート（ａ３）、及び水酸基を有する（メタ）アクリレート（ａ４）を、それぞれ、（メタ）アクリレート（ａ１）、（メタ）アクリレート（ａ２）、（メタ）アクリレート（ａ３）、及び（メタ）アクリレート（ａ４）と称することがある。また、炭素数４～７のアルキル基を有するアルキル（メタ）アクリレート（ａ－１）、炭素数８～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ－２）、式（１）で表される（メタ）アクリレート（ａ３－１）、及び式（２）で表される（メタ）アクリレート（ａ３－２）を、それぞれ、（メタ）アクリレート（ａ－１）、（メタ）アクリレート（ａ－２）、（メタ）アクリレート（ａ３－１）、及び（メタ）アクリレート（ａ３－２）と称することがある。
　本明細書に記載する各種成分は、特に注釈しない限り、それぞれ独立に１種単独で、又は２種以上を混合して用いてもよい。 Before describing the present invention in detail, a definition of terms is provided. First, sheet, film and tape are synonyms.
(Meth)acrylic acid includes acrylic acid and methacrylic acid. (Meth)acrylates include acrylates and methacrylates. A monomer is a monomer having an ethylenically unsaturated double bond.
The adherend refers to the other party to which the pressure-sensitive adhesive sheet is attached.
In this specification, alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, (meth)acrylate (a2) having no reactive functional group and having an aliphatic cyclic structure, and carboxyl (meth)acrylate (a3) having a group and (meth)acrylate (a4) having a hydroxyl group, respectively, (meth)acrylate (a1), (meth)acrylate (a2), (meth)acrylate (a3), and (meth)acrylate (a4). In addition, an alkyl (meth)acrylate (a-1) having an alkyl group having 4 to 7 carbon atoms, an alkyl (meth)acrylate (a-2) having an alkyl group having 8 to 12 carbon atoms, represented by formula (1) (meth)acrylate (a3-1) represented by formula (2) and (meth)acrylate (a3-2) represented by formula (2), respectively, (meth)acrylate (a-1) and (meth)acrylate (a -2), (meth)acrylate (a3-1), and (meth)acrylate (a3-2).
Unless otherwise noted, the various components described herein may be used singly or in combination of two or more.
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、共重合体（Ａ）と硬化剤（Ｂ）とを含む。上記共重合体（Ａ）は、炭素数４～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ１）、反応性官能基を有さず、脂肪族環式構造を有する（メタ）アクリレート（ａ２）、及びカルボキシル基を有する（メタ）アクリレート（ａ３）を含有するモノマー混合物の共重合体である。上記カルボキシル基を有する（メタ）アクリレート（ａ３）は、一般式（１）で表される（メタ）アクリレート（ａ３－１）及び一般式（２）で表される（メタ）アクリレート（ａ３－２）からなる群から選択される少なくとも１つを含む。
Figure JPOXMLDOC01-appb-C000005
 （式中、Ｒ１は水素原子又はメチル基、ｍは２～１０の整数、ｎは１～５の整数を示す。）
Figure JPOXMLDOC01-appb-C000006
 （式中、Ｒ２は水素原子又はメチル基、Ｒ３は２価の炭化水素基、ｐは１～５の整数を示す。） 1. Adhesive Composition The adhesive composition that is one embodiment of the present invention contains a copolymer (A) and a curing agent (B). The copolymer (A) includes an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, and a (meth)acrylate (a2) having no reactive functional group and having an aliphatic cyclic structure. ) and a monomer mixture containing a (meth)acrylate (a3) having a carboxyl group. The (meth)acrylate (a3) having a carboxyl group includes (meth)acrylate (a3-1) represented by general formula (1) and (meth)acrylate (a3-2) represented by general formula (2). ) including at least one selected from the group consisting of
Figure JPOXMLDOC01-appb-C000005
 (In the formula, R 1 is a hydrogen atom or a methyl group, m is an integer of 2 to 10, and n is an integer of 1 to 5.)
Figure JPOXMLDOC01-appb-C000006
 (In the formula, R 2 is a hydrogen atom or a methyl group, R 3 is a divalent hydrocarbon group, and p is an integer of 1 to 5.)
　上記実施形態によれば、反応性官能基を有さず、脂肪族環式構造を有する（メタ）アクリレート（ａ２）を用いることによって、共重合体の極性を下げて低極性被着体との密着性を向上させ、それと同時に低極性の粘着付与樹脂との相溶性を向上させることができる。また、一般式（１）又は一般式（２）で表されるカルボキシル基を有する（メタ）アクリレートを用いることによって、粘着剤層に凝集力と柔軟性とを付与することができる。そして、上記の複合によって、薄膜でありながらも、高極性被着体及び低極性被着体のいずれに対しても高い粘着力が得られ、また優れた保持力及び曲面接着性を得ることができる。 According to the above embodiment, by using the (meth)acrylate (a2) having an aliphatic cyclic structure without a reactive functional group, the polarity of the copolymer is lowered to Adhesion can be improved, and at the same time, compatibility with low-polarity tackifying resins can be improved. Further, by using a (meth)acrylate having a carboxyl group represented by general formula (1) or general formula (2), cohesion and flexibility can be imparted to the pressure-sensitive adhesive layer. And, by the above combination, even though it is a thin film, it is possible to obtain high adhesive strength to both high-polarity adherends and low-polarity adherends, and to obtain excellent holding power and curved surface adhesion. can.
＜共重合体（Ａ）＞
　共重合体（Ａ）は、炭素数４～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ１）、反応性官能基を有さず、脂肪族環式構造を有する（メタ）アクリレート（ａ２）、及びカルボキシル基を有する（メタ）アクリレート（ａ３）を含み、さらに任意モノマーとして、必要に応じて、水酸基を有する（メタ）アクリレート（ａ４）、及びその他モノマーを含む、モノマー混合物を重合してなる共重合体である。 <Copolymer (A)>
The copolymer (A) includes an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, and a (meth)acrylate (a2) having no reactive functional group and having an aliphatic cyclic structure. , and a (meth)acrylate (a3) having a carboxyl group, and optionally a (meth)acrylate (a4) having a hydroxyl group and other monomers as optional monomers, obtained by polymerizing a monomer mixture It is a copolymer.
　共重合体（Ａ）の酸価は、０．１～２４．０ｍｇＫＯＨ／ｇであることが好ましく、０．２～２０．０ｍｇＫＯＨ／ｇがより好ましい。共重合体（Ａ）の酸価が０．１～２４．０ｍｇＫＯＨ／ｇである場合、粘着剤層の凝集力と柔軟性とをバランスよく付与することができ、粘着力、保持力、及び曲面接着性の両立がより容易になる。 The acid value of the copolymer (A) is preferably 0.1-24.0 mgKOH/g, more preferably 0.2-20.0 mgKOH/g. When the acid value of the copolymer (A) is 0.1 to 24.0 mgKOH/g, the cohesive force and flexibility of the adhesive layer can be imparted in a well-balanced manner, and the adhesive force, holding force, and curved surface It becomes easier to achieve both adhesiveness.
［（メタ）アクリレート（ａ１）］
　（メタ）アクリレート（ａ１）は、炭素数４～１２のアルキル基を有するアルキル（メタ）アクリレートである。（メタ）アクリレート（ａ１）は、モノマー混合物の全質量を基準（１００質量％）として、モノマー混合物１００質量％中に、好ましくは６０質量％以上、より好ましくは７０質量％以上の含有量であってよい。一方、上記含有量は、好ましくは９９質量％以下、より好ましくは９８質量％以下、さらに好ましくは９５質量％以下、さらにより好ましくは９２質量％以下であってよい。
　一実施形態において、（メタ）アクリレート（ａ１）の含有量は、モノマー混合物１００質量％中に、６０～９９質量％が好ましく、７０～９８質量％がより好ましい。上記含有量を６０～９９質量％にした場合、粘着力、保持力、及び曲線接着性の両立がより容易になる。高極性被着体及び低極性被着体に対する粘着力の両立、並びに粘着付与樹脂との相溶性の観点から、（メタ）アクリレート（ａ１）は、炭素数４～７のアルキル基を有するアルキル（メタ）アクリレート（ａ－１）、及び、炭素数８～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ－２）を含有することが好ましい。 [(meth)acrylate (a1)]
(Meth)acrylate (a1) is an alkyl (meth)acrylate having an alkyl group having 4 to 12 carbon atoms. (Meth)acrylate (a1) is preferably 60% by mass or more, more preferably 70% by mass or more in 100% by mass of the monomer mixture based on the total mass of the monomer mixture (100% by mass). you can On the other hand, the content may be preferably 99% by mass or less, more preferably 98% by mass or less, still more preferably 95% by mass or less, and even more preferably 92% by mass or less.
In one embodiment, the content of (meth)acrylate (a1) is preferably 60 to 99% by mass, more preferably 70 to 98% by mass, based on 100% by mass of the monomer mixture. When the above content is 60 to 99% by mass, it becomes easier to achieve both adhesive strength, holding power, and curve adhesiveness. From the viewpoint of compatibility with high-polarity adherends and low-polarity adherends and compatibility with tackifying resins, (meth)acrylate (a1) is an alkyl group having 4 to 7 carbon atoms ( It preferably contains a meth)acrylate (a-1) and an alkyl (meth)acrylate (a-2) having an alkyl group with 8 to 12 carbon atoms.
　（メタ）アクリレート（ａ－１）成分の（メタ）アクリレート（ａ－２）成分に対する含有割合（比率）は、重量比で、（ａ－１）／（ａ－２）＝９９／１～２０／８０が好ましく、９８／２～５０／５０がより好ましく、９５／５～６０／４０がさらに好ましい。上記成分を上記比率で使用することによって、高極性被着体に対する粘着力と、低極性被着体に対する粘着力とを両立することが容易となり、粘着付与樹脂との相溶性を向上させ、さらに粘着力を向上することもできる。 The content ratio (ratio) of the (meth)acrylate (a-1) component to the (meth)acrylate (a-2) component is (a-1)/(a-2) = 99/1 to 20 by weight. /80 is preferred, 98/2 to 50/50 is more preferred, and 95/5 to 60/40 is even more preferred. By using the above components in the above ratio, it becomes easy to achieve both adhesion to high-polarity adherends and adhesion to low-polarity adherends, and compatibility with tackifying resins is improved. It can also improve adhesion.
　炭素数４～７のアルキル基を有するアルキル（メタ）アクリレート（ａ－１）として、例えば、ｎ－ブチル（メタ）アクリレート、イソブチル（メタ）アクリレート、及びｎ－ヘキシル（メタ）アクリレート等が挙げられる。これらのなかでも、粘着力と保持力との両立の観点から、ｎ－ブチル（メタ）アクリレートが好ましい。 Examples of the alkyl (meth)acrylate (a-1) having an alkyl group having 4 to 7 carbon atoms include n-butyl (meth)acrylate, isobutyl (meth)acrylate, and n-hexyl (meth)acrylate. . Among these, n-butyl (meth)acrylate is preferred from the viewpoint of achieving both adhesive strength and holding power.
　炭素数８～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ－２）として、例えば、２－エチルヘキシル（メタ）アクリレート、ｎ－オクチル（メタ）アクリレート、イソオクチル（メタ）アクリレート、ｎ－ノニル（メタ）アクリレート、イソノニル（メタ）アクリレート、ｎ－デシル（メタ）アクリレート、イソデシル（メタ）アクリレート、ドデシル（メタ）アクリレート等が挙げられる。これらのなかでも、粘着力と保持力との両立の観点から、２－エチルヘキシル（メタ）アクリレートが好ましい。 Examples of the alkyl (meth)acrylate (a-2) having an alkyl group having 8 to 12 carbon atoms include 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl ( meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate and the like. Among these, 2-ethylhexyl (meth)acrylate is preferred from the viewpoint of achieving both adhesive strength and holding power.
［（メタ）アクリレート（ａ２）］
　（メタ）アクリレート（ａ２）は、反応性官能基を有さず、脂肪族環式構造を有する（メタ）アクリレートである。
　（メタ）アクリレート（ａ２）は、モノマー混合物１００質量％中に、１～２０質量％の含有量で使用することが好ましい。上記含有量は、２～１５質量％がより好ましい。（メタ）アクリレート（ａ２）を１～２０質量％の含有量で使用することによって、粘着力、保持力、及び曲線接着性の両立がより容易になる。 [(meth)acrylate (a2)]
(Meth)acrylate (a2) is a (meth)acrylate having no reactive functional group and having an alicyclic structure.
(Meth)acrylate (a2) is preferably used in a content of 1 to 20% by mass based on 100% by mass of the monomer mixture. The above content is more preferably 2 to 15% by mass. By using the (meth)acrylate (a2) in a content of 1 to 20% by mass, it becomes easier to achieve both adhesive strength, holding power and curvilinear adhesiveness.
　（メタ）アクリレート（ａ２）は、アクリロイル基以外の反応性官能基を有さないことを特徴とする。反応性官能基として、例えば、カルボキシル基、水酸基、アミノ基、及びエポキシ基などが挙げられる。
　脂肪族環式構造としては、例えば、シクロヘキシル基、ジシクロペンテニル基、ジシクロペンタニル基、及びイソボルニル基などが挙げられる。低極性被着体に対する粘着力、及び粘着付与樹脂との相溶性を向上させる観点から、脂肪族環式構造として、ジシクロペンテニル基、ジシクロペンタニル基、又はイソボルニル基を有することが好ましい。 (Meth)acrylate (a2) is characterized by not having a reactive functional group other than an acryloyl group. Examples of reactive functional groups include carboxyl groups, hydroxyl groups, amino groups, and epoxy groups.
Aliphatic cyclic structures include, for example, a cyclohexyl group, a dicyclopentenyl group, a dicyclopentanyl group, and an isobornyl group. From the viewpoint of improving adhesive strength to low-polar adherends and compatibility with tackifying resins, it is preferable to have a dicyclopentenyl group, a dicyclopentanyl group, or an isobornyl group as the aliphatic cyclic structure.
　（メタ）アクリレート（ａ２）としては、例えば、シクロヘキシル（メタ）アクリレート、ジシクロペンテニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、及びイソボルニル（メタ）アクリレート等が挙げられる。このなかでも、低極性被着体に対する粘着力、及び粘着付与樹脂との相溶性の向上の観点から、立体的な脂肪族環式構造を有する、ジシクロペンテニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、及びイソボルニル（メタ）アクリレートが好ましく、イソボルニル（メタ）アクリレートがさらに好ましい。 (Meth)acrylates (a2) include, for example, cyclohexyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and isobornyl (meth)acrylate. Among these, dicyclopentenyl (meth)acrylate and dicyclopentanyl having a three-dimensional aliphatic cyclic structure from the viewpoint of improving the adhesive strength to low-polar adherends and compatibility with tackifying resins (Meth)acrylates and isobornyl (meth)acrylates are preferred, and isobornyl (meth)acrylates are more preferred.
［（メタ）アクリレート（ａ３）］
　（メタ）アクリレート（ａ３）は、カルボキシル基を有する（メタ）アクリレートであり、一般式（１）で表される（メタ）アクリレート（ａ３－１）及び一般式（２）で表される（メタ）アクリレート（ａ３－２）の少なくともいずれか一方を含む。
　なかでも、高極性被着体及び低極性被着体の両方に対する粘着力を得る観点から、式（２）で表される（メタ）アクリレート（ａ３－２）を含有することがより好ましい。 [(meth)acrylate (a3)]
(Meth)acrylate (a3) is a (meth)acrylate having a carboxyl group, and (meth)acrylate (a3-1) represented by general formula (1) and general formula (2) (meth) ) contains at least one of acrylates (a3-2).
Among them, it is more preferable to contain (meth)acrylate (a3-2) represented by formula (2) from the viewpoint of obtaining adhesive strength to both high-polarity adherends and low-polarity adherends.
　（メタ）アクリレート（ａ３）は、モノマー混合物１００質量％中に、０．１～１０質量％の含有量で使用することが好ましい。上記含有量は、０．２～８質量％がより好ましい。（メタ）アクリレート（ａ３）を０．１～１０質量％の含有量で使用することによって、粘着力、保持力、及び曲線接着性の両立がより容易になる。 (Meth)acrylate (a3) is preferably used in a content of 0.1 to 10% by mass based on 100% by mass of the monomer mixture. The above content is more preferably 0.2 to 8% by mass. By using the (meth)acrylate (a3) in a content of 0.1 to 10% by mass, it becomes easier to achieve both adhesive strength, holding power, and curve adhesiveness.
（（メタ）アクリレート（ａ３－１））
　（メタ）アクリレート（ａ３－１）は、一般式（１）で表される（メタ）アクリレートである。
Figure JPOXMLDOC01-appb-C000007
 （式中、Ｒ１は水素原子又はメチル基、ｍは２～１０の整数、ｎは１～５の整数を示す。） ((meth) acrylate (a3-1))
(Meth)acrylate (a3-1) is a (meth)acrylate represented by general formula (1).
Figure JPOXMLDOC01-appb-C000007
 (In the formula, R 1 is a hydrogen atom or a methyl group, m is an integer of 2 to 10, and n is an integer of 1 to 5.)
　一般式（１）において、ｍは２～１０の整数を示す。ｍは、粘着力、保持力、及び曲面接着性の両立の観点から、２～１０の整数である。ｍは、好ましくは２～８の整数、さらに好ましくは３～５の整数である。ｎは１～５の整数を示す。ｎは、粘着力、保持力、及び曲面接着性の両立の観点から、１～５の整数であってよいが、好ましくは２～４の整数である。 In general formula (1), m represents an integer of 2-10. m is an integer of 2 to 10 from the viewpoint of coexistence of adhesive strength, holding power and curved surface adhesiveness. m is preferably an integer of 2-8, more preferably an integer of 3-5. n represents an integer of 1-5. n may be an integer of 1 to 5, preferably an integer of 2 to 4, from the viewpoint of compatibility between adhesive strength, holding power, and curved surface adhesiveness.
　（メタ）アクリレート（ａ３－１）は、常法により製造したものであっても、市販のモノマーから適宜選択したものであってもよい。
　（メタ）アクリレート（ａ３－１）として、例えば、β－ヒドロキシエチルアクリレート、及びω－カルボキシポリカプロラクトンモノ（メタ）アクリレート等が挙げられる。これらのモノマーは、例えば「β－ＣＥＡ」（ダイセル・オルネクス社製）、及び「アロニックスＭ－５３００」（東亞合成社製）の商品名として市販されており、これら市販品を用いることができる。 (Meth)acrylate (a3-1) may be one produced by a conventional method, or one appropriately selected from commercially available monomers.
(Meth)acrylates (a3-1) include, for example, β-hydroxyethyl acrylate and ω-carboxypolycaprolactone mono(meth)acrylate. These monomers are commercially available, for example, under the trade names of "β-CEA" (manufactured by Daicel Ornex) and "Aronix M-5300" (manufactured by Toagosei Co., Ltd.), and these commercial products can be used.
（（メタ）アクリレート（ａ３－２））
　（メタ）アクリレート（ａ３－２）は、一般式（２）で表される（メタ）アクリレートである。
Figure JPOXMLDOC01-appb-C000008
 （式中、Ｒ２は水素原子又はメチル基、Ｒ３は２価の炭化水素基、ｐは１～５の整数を示す。） ((meth) acrylate (a3-2))
(Meth)acrylate (a3-2) is a (meth)acrylate represented by general formula (2).
Figure JPOXMLDOC01-appb-C000008
 (In the formula, R 2 is a hydrogen atom or a methyl group, R 3 is a divalent hydrocarbon group, and p is an integer of 1 to 5.)
　一般式（２）において、ｐは１～５の整数を示す。ｐは、粘着力、保持力、及び曲面接着性の両立の観点から、１～５の整数であってよいが、好ましくは１～３の整数である。Ｒ３は２価の炭化水素基を示す。
　炭化水素基として、例えば、アルキレン基等の飽和脂肪族炭化水素基、シクロアルキレン基等の飽和脂環族炭化水素基、フェニレン基等の芳香族炭化水素基、不飽和脂肪族炭化水素基、または不飽和脂環族炭化水素基などが挙げられる。
　これらのなかでも、柔軟性付与による粘着力向上の観点から、Ｒ３は、飽和脂肪族炭化水素基であることが好ましい。Ｒ３は、アルキレン基であることがより好ましく、炭素数１～４のアルキレン基であることがさらに好ましい。 In general formula (2), p represents an integer of 1-5. p may be an integer of 1 to 5, preferably an integer of 1 to 3, from the viewpoint of compatibility between adhesive strength, holding power, and curved surface adhesiveness. R3 represents a divalent hydrocarbon group.
Examples of hydrocarbon groups include saturated aliphatic hydrocarbon groups such as alkylene groups, saturated alicyclic hydrocarbon groups such as cycloalkylene groups, aromatic hydrocarbon groups such as phenylene groups, unsaturated aliphatic hydrocarbon groups, or Examples include unsaturated alicyclic hydrocarbon groups.
Among these, R 3 is preferably a saturated aliphatic hydrocarbon group from the viewpoint of improving adhesion by imparting flexibility. R 3 is more preferably an alkylene group, more preferably an alkylene group having 1 to 4 carbon atoms.
　（メタ）アクリレート（ａ３－２）は、常法により製造したものであっても、市販のモノマーから適宜選択したものであってもよい。
　（メタ）アクリレート（ａ３－２）として、例えば、２－（メタ）アクリロイルオキシエチルコハク酸、２－（メタ）アクリロイルオキシエチルフマル酸、及び２－（メタ）アクリロイルオキシエチルフタル酸等が挙げられる。これらのモノマーは、例えば、「ライトエステルＨＯ－ＭＳ」、「ＨＯＡ－ＭＳ（Ｎ）」、「ライトアクリレートＨＯＡ－ＨＨ（Ｎ）」及び「ＨＯＡ－ＭＰＬ（Ｎ）」（共栄社化学社製）の商品名として市販されており、これら市販品を用いることができる。 (Meth)acrylate (a3-2) may be one produced by a conventional method, or one appropriately selected from commercially available monomers.
Examples of (meth)acrylates (a3-2) include 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxyethyl fumarate, and 2-(meth)acryloyloxyethyl phthalate. . These monomers are, for example, "light ester HO-MS", "HOA-MS (N)", "light acrylate HOA-HH (N)" and "HOA-MPL (N)" (manufactured by Kyoeisha Chemical Co., Ltd.). It is marketed as a brand name, and these commercial products can be used.
　（メタ）アクリレート（ａ３）は、（メタ）アクリレート（ａ３－１）、及び（メタ）アクリレート（ａ３－２）に加えて、これら以外の、その他カルボキシル基を有する（メタ）アクリレート（ａ３－３）をさらに含有してもよい。
　その他カルボキシル基を有する（メタ）アクリレート（ａ３－３）としては、例えば（メタ）アクリル酸等が挙げられる。 (Meth)acrylate (a3), in addition to (meth)acrylate (a3-1) and (meth)acrylate (a3-2), (meth)acrylate (a3-3) having a carboxyl group other than these ) may be further contained.
Other (meth)acrylates (a3-3) having a carboxyl group include, for example, (meth)acrylic acid.
　（メタ）アクリレート（ａ３）として、（メタ）アクリレート（ａ３－１）又は（メタ）アクリレート（ａ３－２）を使用することで、側鎖の末端に存在するカルボシキル基、及び（メタ）アクリレート（ａ２）由来の大きな脂肪族環式構造が、高極性被着体又は低極性被着体に密着することを互いに妨害せず、高極性被着体への粘着力と低極性被着体への粘着力との両立が可能となる。 By using (meth)acrylate (a3-1) or (meth)acrylate (a3-2) as (meth)acrylate (a3), the carboxyl group present at the end of the side chain and the (meth)acrylate ( The large aliphatic cyclic structure derived from a2) does not interfere with each other from adhering to a highly polar adherend or a low polar adherend, and has adhesion to a highly polar adherend and adhesion to a low polar adherend. It is possible to achieve compatibility with adhesive strength.
　（メタ）アクリル酸のような側鎖が短いカルボキシル基を有する（メタ）アクリレートに比べて、（メタ）アクリレート（ａ３－１）及び（メタ）アクリレート（ａ３－２）は、アクリルポリマーの主鎖とカルボキシル基との距離が離れている。そのため、（メタ）アクリレート（ａ２）由来の大きな脂肪族環式構造に邪魔されることなく、高極性被着体に対してより優れた密着性を得ることができる。また、側鎖が長すぎないことで、低極性被着体に対する（メタ）アクリレート（ａ２）由来の脂肪族環式構造の密着を妨害することを抑制できる。 (Meth) acrylate (a3-1) and (meth) acrylate (a3-2) are the main chain of the acrylic polymer compared to (meth) acrylates having short carboxyl groups in side chains such as acrylic acid and the carboxyl group are far apart. Therefore, excellent adhesion to a highly polar adherend can be obtained without being disturbed by the large alicyclic structure derived from the (meth)acrylate (a2). In addition, since the side chain is not too long, it is possible to suppress interference with the adhesion of the (meth)acrylate (a2)-derived aliphatic cyclic structure to the low-polar adherend.
　一実施形態において、（メタ）アクリレート（ａ３）の全質量を基準（１００質量％）として、（メタ）アクリレート（ａ３－１）及び（メタ）アクリレート（ａ３－２）以外の、その他カルボキシル基を有する（メタ）アクリレート（ａ３－３）の含有量は４３質量％以下であってよい。一実施形態において、（メタ）アクリレート（ａ３）は、（メタ）アクリレート（ａ３－１）及び（メタ）アクリレート（ａ３－２）と、その他カルボキシル基を有する（メタ）アクリレート（ａ３－３）とを含み、（メタ）アクリレート（ａ３）１００質量％中の、（メタ）アクリレート（ａ３－３）の含有量は０．１質量％を超え、４３質量％以下であってよい。他の実施形態において、（メタ）アクリレート（ａ３）は、（メタ）アクリレート（ａ３－１）と（メタ）アクリレート（ａ３－２）とのみを含み、その他カルボキシル基を有する（メタ）アクリレート（ａ３－３）を含まない。すなわち、（メタ）アクリレート（ａ３－３）の含有量は０質量％であってもよい。
　（メタ）アクリレート（ａ３－１）及び（メタ）アクリレート（ａ３－２）以外の（メタ）アクリレート（ａ３）成分の含有量は、少ないほど好ましい。一実施形態において、上記成分の含有量は、（メタ）アクリレート（ａ３）の合計１００質量％中に、４０質量％以下であることが好ましく、３０質量％以下であることがより好ましく、２０質量％以下であることがさらに好ましい。上記含有量は０質量％であってもよい。上記含有量を４０質量％以下に調整した場合、高極性被着体及び低極性被着体の双方に対して優れた粘着力を容易に得ることができるために好ましい。 In one embodiment, based on the total mass of (meth)acrylate (a3) (100% by mass), other carboxyl groups other than (meth)acrylate (a3-1) and (meth)acrylate (a3-2) The content of (meth)acrylate (a3-3) may be 43% by mass or less. In one embodiment, (meth)acrylate (a3) includes (meth)acrylate (a3-1) and (meth)acrylate (a3-2), and (meth)acrylate (a3-3) having a carboxyl group. and the content of (meth)acrylate (a3-3) in 100% by mass of (meth)acrylate (a3) may be greater than 0.1% by mass and 43% by mass or less. In another embodiment, (meth)acrylate (a3) contains only (meth)acrylate (a3-1) and (meth)acrylate (a3-2), and (meth)acrylate (a3) having a carboxyl group -3) is not included. That is, the content of (meth)acrylate (a3-3) may be 0% by mass.
The content of the (meth)acrylate (a3) component other than (meth)acrylate (a3-1) and (meth)acrylate (a3-2) is preferably as low as possible. In one embodiment, the content of the above components is preferably 40% by mass or less, more preferably 30% by mass or less, based on the total 100% by mass of the (meth)acrylate (a3), and 20% by mass. % or less. The above content may be 0% by mass. When the above content is adjusted to 40% by mass or less, excellent adhesion to both highly polar adherends and low polar adherends can be easily obtained, which is preferable.
［（メタ）アクリレート（ａ４）］
　（メタ）アクリレート（ａ４）は、水酸基を有する（メタ）アクリレートである。上記実施形態において、上記モノマー混合物は、さらに水酸基を有する（メタ）アクリレート（ａ４）を含むことができる。
　水酸基を有する（メタ）アクリレート（ａ４）を含有することで、凝集力を発現しやすく、優れた保持力と曲面接着性とを容易に得ることができるために好ましい。水酸基を有する（メタ）アクリレート（ａ４）は、モノマー混合物１００質量％中に、０．０５～３質量％の含有量で使用することが好ましい。上記含有量は０．１～２質量％がより好ましい。水酸基を有する（メタ）アクリレート（ａ４）を０．０５～３質量％の含有量で使用した場合、粘着剤層の凝集力が向上、保持力及び曲面接着性の向上がより容易になる。 [(meth)acrylate (a4)]
(Meth)acrylate (a4) is a (meth)acrylate having a hydroxyl group. In the above embodiment, the monomer mixture may further contain a (meth)acrylate (a4) having a hydroxyl group.
Inclusion of a (meth)acrylate (a4) having a hydroxyl group is preferable because cohesive force can be easily expressed and excellent holding power and curved surface adhesiveness can be easily obtained. The (meth)acrylate (a4) having a hydroxyl group is preferably used in a content of 0.05 to 3% by mass based on 100% by mass of the monomer mixture. More preferably, the content is 0.1 to 2% by mass. When the hydroxyl group-containing (meth)acrylate (a4) is used at a content of 0.05 to 3% by mass, the cohesive strength of the pressure-sensitive adhesive layer is improved, making it easier to improve the holding power and adhesion to curved surfaces.
　水酸基を有する（メタ）アクリレート（ａ４）は、例えば、２－ヒドロキシエチル（メタ）アクリレート、２－ヒドロキシプロピル（メタ）アクリレート、３－ヒドロキシプロピル（メタ）アクリレート、２－ヒドロキシブチル（メタ）アクリレート、酸３－ヒドロキシブチル（メタ）アクリレート、４－ヒドロキシブチル（メタ）アクリレート、６－ヒドロキシヘキシル（メタ）アクリレート、及び８－ヒドロキシオクチル（メタ）アクリレートなどのヒドロキシアルキル（メタ）アクリレート、並びにポリエチレングリコールモノ（メタ）アクリレート、ポリプロピレングリコールモノ（メタ）アクリルレート、及び１，４－シクロヘキサンジメタノールモノ（メタ）アクリレートなどのグリコールモノ（メタ）アクリレート、等が挙げられる。これらのなかでも、２－ヒドロキシエチル（メタ）アクリレートが好ましい。 (Meth)acrylates (a4) having a hydroxyl group include, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, Hydroxyalkyl (meth)acrylates such as acid 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate, and polyethylene glycol mono (meth)acrylates, polypropylene glycol mono(meth)acrylates, and glycol mono(meth)acrylates such as 1,4-cyclohexanedimethanol mono(meth)acrylate, and the like. Among these, 2-hydroxyethyl (meth)acrylate is preferred.
［その他モノマー］
　その他モノマーは、炭素数４～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ１）、反応性官能基を有さず、脂肪族環式構造を有する（メタ）アクリレート（ａ２）、及びカルボキシル基を有する（メタ）アクリレート（ａ３）、水酸基を有する（メタ）アクリレート（ａ４）以外の、その他（メタ）アクリレートと、（メタ）アクリレート以外のモノマーである。
　その他モノマーは、粘着剤の粘着力、保持力、及び曲面接着性を損なわない範囲で用いることができる。具体的には、（メタ）アクリレート（ａ１）以外のアルキル基を有するアルキル（メタ）アクリレート等が挙げられる。他の具体例として、例えばアミド結合を有するモノマー、エポキシ基を有するモノマー、アミノ基を有するモノマー、芳香環を有するモノマー、アルコキシ（ポリ）アルキレンオキサイドを有するモノマー、及びその他ビニルモノマー等が挙げられる。 [Other monomers]
Other monomers include an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, a (meth)acrylate (a2) having an aliphatic cyclic structure without a reactive functional group, and a carboxyl group. and (meth)acrylates other than (a3) having a hydroxyl group (meth)acrylate (a4) and monomers other than (meth)acrylates.
Other monomers can be used as long as they do not impair the adhesive strength, holding power, and curved surface adhesiveness of the adhesive. Specific examples thereof include alkyl (meth)acrylates having an alkyl group other than (meth)acrylate (a1). Other specific examples include monomers having an amide bond, monomers having an epoxy group, monomers having an amino group, monomers having an aromatic ring, monomers having an alkoxy(poly)alkylene oxide, and other vinyl monomers.
　上記（メタ）アクリレート（ａ１）以外のアルキル（メタ）アクリレートモノマーは、例えば、メチル（メタ）アクリレート、エチル（メタ）アクリレート、ｎ－プロピル（メタ）アクリレート、イソプロピル（メタ）アクリレート、ｎ－オクタデシル（メタ）アクリレート、及びイソオクタデシル（メタ）アクリレート等が挙げられる。
　（メタ）アクリレート（ａ１）以外のアルキル（メタ）アクリレートモノマーを用いる場合、その含有量は、モノマー混合物１００質量％中、０．１～２０質量％であることが好ましい。 Alkyl (meth)acrylate monomers other than the (meth)acrylate (a1) include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-octadecyl ( meth)acrylate, and isooctadecyl (meth)acrylate, and the like.
When using an alkyl (meth)acrylate monomer other than (meth)acrylate (a1), the content thereof is preferably 0.1 to 20% by mass in 100% by mass of the monomer mixture.
　アミド結合を有するモノマーは、例えば、（メタ）アクリルアミド、Ｎ－メチルアクリルアミド、Ｎ－イソプロピルアクリルアミド、Ｎ，Ｎ－ジメチルアクリルアミド、Ｎ，Ｎ－ジエチルアクリルアミド、Ｎ、Ｎ－ジメチルアミノプロピル（メタ）アクリルアミド、ジアセトンアクリルアミド、及びＮ－(ブトキシメチル)アクリルアミド等の（メタ）アクリルアミド系化合物、並びにＮ－ビニルピロリドン、Ｎ－ビニルカプロラクタム、及びアクリロイルモルホリン等の複素環含有化合物等が挙げられる。
　エポキシ基を有するモノマーは、例えば、グリシジル（メタ）アクリレート、メチルグリシジル（メタ）アクリレート、及び３，４－エポキシシクロヘキシルメチル（メタ）アクリレート等が挙げられる。
　アミノ基を有するモノマーは、例えば、モノメチルアミノエチル（メタ）アクリレート、モノエチルアミノエチル（メタ）アクリレート、モノメチルアミノプロピル（メタ）アクリレート、及びモノエチルアミノプロピル（メタ）アクリレート等のモノアルキルアミノ（メタ）アクリレート等が挙げられる。
　アミド結合を有するモノマー、エポキシ基を有するモノマー、及びアミノ基を有するモノマーを用いる場合、その含有率は、モノマー混合物１００質量％中、それぞれ０．１～１質量％であることが好ましい。 Monomers having an amide bond include, for example, (meth)acrylamide, N-methylacrylamide, N-isopropylacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-dimethylaminopropyl(meth)acrylamide, (Meth)acrylamide compounds such as diacetoneacrylamide and N-(butoxymethyl)acrylamide, and heterocyclic ring-containing compounds such as N-vinylpyrrolidone, N-vinylcaprolactam, and acryloylmorpholine.
Examples of monomers having an epoxy group include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, and the like.
Monomers having an amino group are, for example, monoalkylamino (meth)acrylates such as monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, monomethylaminopropyl (meth)acrylate, and monoethylaminopropyl (meth)acrylate. ) acrylates and the like.
When a monomer having an amide bond, a monomer having an epoxy group, and a monomer having an amino group are used, their content is preferably 0.1 to 1% by mass in 100% by mass of the monomer mixture.
　芳香環を有するモノマーは、例えば、フェノキシエチルアクリレート、ベンジルアクリレート、フェノキシジエチレングリコール（メタ）アクリレート、及びエチレンオキサイド変性ノニルフェノール（メタ）アクリレート等が挙げられる。
　芳香環を有するモノマーを用いる場合、その含有率は、モノマー混合物１００質量％中、０．１～１０質量％であることが好ましい。 Examples of aromatic ring-containing monomers include phenoxyethyl acrylate, benzyl acrylate, phenoxydiethylene glycol (meth)acrylate, and ethylene oxide-modified nonylphenol (meth)acrylate.
When a monomer having an aromatic ring is used, its content is preferably 0.1 to 10% by mass in 100% by mass of the monomer mixture.
　アルコキシ（ポリ）アルキレンオキサイドを有するモノマーは、例えば、２－メトキシエチルアクリレート、２－エトキシエチルアクリレート、２－フェノキシエチルアクリレート、メトキシポリエチレングリコール（メタ）アクリレート、エトキシポリエチレングリコール（メタ）アクリレート、メトキシポリプロピレングリコール（メタ）アクリレート、エトキシポリプロピレングリコール（メタ）アクリレート、フェノキシポリエチレングリコール（メタ）アクリレート、及びフェノキシポリプロピレングリコール（メタ）アクリレート等が挙げられる。
　アルコキシ（ポリ）アルキレンオキサイドを有するモノマーを用いる場合、その含有率は、モノマー混合物１００質量％中、０．１～１０質量％であることが好ましい。 Monomers with alkoxy(poly)alkylene oxides are, for example, 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-phenoxyethyl acrylate, methoxypolyethyleneglycol (meth)acrylate, ethoxypolyethyleneglycol (meth)acrylate, methoxypolypropyleneglycol. (Meth)acrylate, ethoxypolypropyleneglycol (meth)acrylate, phenoxypolyethyleneglycol (meth)acrylate, phenoxypolypropyleneglycol (meth)acrylate and the like.
When a monomer having an alkoxy(poly)alkylene oxide is used, its content is preferably 0.1 to 10% by mass based on 100% by mass of the monomer mixture.
　その他ビニルモノマーは、例えば、酢酸ビニル、及びアクリロニトリルなどが挙げられるが、これらに限定されない。
　その他ビニルモノマーを用いる場合、その含有率は、モノマー混合物１００質量％中、０．１～１０質量％であることが好ましい。 Other vinyl monomers include, but are not limited to, vinyl acetate, acrylonitrile, and the like.
When other vinyl monomers are used, their content is preferably 0.1 to 10% by mass in 100% by mass of the monomer mixture.
［共重合体（Ａ）の製造］
　共重合体（Ａ）は、例えば、モノマー混合物に重合開始剤を加え、溶液重合することで得ることができる。上記溶液重合に使用する溶剤は、例えば、酢酸メチル、酢酸エチル、酢酸ｎ－ブチル、酢酸イソブチル、トルエン、キシレン、ヘキサン、アセトン、メチルエチルケトン、メチルイソブチルケトン、メタノール、エタノール、ｎ－プロパノール、及びイソプロパノール等が好ましく、酢酸エチルがより好ましい。 [Production of copolymer (A)]
The copolymer (A) can be obtained, for example, by adding a polymerization initiator to a monomer mixture and carrying out solution polymerization. Solvents used in the solution polymerization include, for example, methyl acetate, ethyl acetate, n-butyl acetate, isobutyl acetate, toluene, xylene, hexane, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, and isopropanol. is preferred, and ethyl acetate is more preferred.
　溶液重合は、モノマー混合物の１００質量部に対して、重合開始剤を０．００１～１質量部程度加えて重合を行うことが好ましい。通常、重合は、窒素気流下で、５０℃～９０℃程度の温度で、６時間～２０時間にわたって行うことができる。また、重合の際、連鎖移動剤を使用して、共重合体の重量平均分子量を適宜調整することができる。 In solution polymerization, it is preferable to add about 0.001 to 1 part by mass of a polymerization initiator to 100 parts by mass of the monomer mixture. Generally, the polymerization can be carried out at a temperature of about 50° C. to 90° C. for 6 hours to 20 hours under nitrogen stream. Moreover, the weight average molecular weight of the copolymer can be appropriately adjusted by using a chain transfer agent during the polymerization.
　一実施形態において、共重合体（Ａ）の重量平均分子量（Ｍｗ）は、３０万～１５０万が好ましく、５０万～１３０万がより好ましく、６０万～１２０万がさらに好ましい。Ｍｗを３０万～１５０万の範囲に調整した場合、粘着力、保持力、及び曲面接着性の両立が容易になる。なお、本明細書に記載する重量平均分子量は、ゲル浸透クロマトグラフィー（ＧＰＣ）によって測定したポリスチレン換算の値である。 In one embodiment, the weight average molecular weight (Mw) of the copolymer (A) is preferably 300,000 to 1,500,000, more preferably 500,000 to 1,300,000, and even more preferably 600,000 to 1,200,000. When Mw is adjusted in the range of 300,000 to 1,500,000, it becomes easy to achieve compatibility between adhesive strength, holding power, and curved surface adhesiveness. In addition, the weight average molecular weight described in this specification is a polystyrene-equivalent value measured by gel permeation chromatography (GPC).
　連鎖移動剤は、例えば、ｎ－ドデシルメルカプタン、メルカプトイソブチルアルコール、メルカプト酢酸、２－メルカプトエタノール、チオグリコール酸、チオグルコール酸２－エチルヘキシル、２，３－ジメルカプト－１－プロパノール、グリシジルメルカプタン、α－メチルスチレンダイマー、四塩化炭素、クロロホルム、及びハイドロキノン等が挙げられる。連鎖移動剤は、モノマー混合物の１００質量部に対して、０．０１～１質量部程度を使用できる。 Chain transfer agents are, for example, n-dodecylmercaptan, mercaptoisobutyl alcohol, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto-1-propanol, glycidylmercaptan, α-methyl Styrene dimer, carbon tetrachloride, chloroform, hydroquinone, and the like. About 0.01 to 1 part by mass of the chain transfer agent can be used with respect to 100 parts by mass of the monomer mixture.
　重合開始剤は、一般的に、アゾ系化合物及び有機過酸化物である。
　アゾ系化合物は、例えば、２，２'－アゾビスイソブチロニトリル、２，２'－アゾビス（２－メチルブチロニトリル）、１，１'－アゾビス（シクロヘキサン１－カルボニトリル）、２，２'－アゾビス（２，４－ジメチルバレロニトリル）、２，２'－アゾビス（２，４－ジメチル－４－メトキシバレロニトリル）、ジメチル２，２'－アゾビス（２－メチルプロピオネート）、４，４'－アゾビス（４－シアノバレリック酸）、２，２'－アゾビス（２－ヒドロキシメチルプロピオニトリル）、及び２，２'－アゾビス（２－（２－イミダゾリン－２－イル）プロパン）等が挙げられる。
　有機過酸化物は、例えば、過酸化ベンゾイル、ｔ－ブチルパーベンゾエイト、クメンヒドロパーオキシド、ジイソプロピルパーオキシジカーボネート、ジ－ｎ－プロピルパーオキシジカーボネート、ジ（２－エトキシエチル）パーオキシジカーボネート、ｔ－ブチルパーオキシネオデカノエート、ｔ－ブチルパーオキシビバレート、（３，５，５－トリメチルヘキサノイル）パーオキシド、ジプロピオニルパーオキシド、及びジアセチルパーオキシド等が挙げられる。 Polymerization initiators are generally azo compounds and organic peroxides.
Azo compounds include, for example, 2,2′-azobisisobutyronitrile, 2,2′-azobis(2-methylbutyronitrile), 1,1′-azobis(cyclohexane 1-carbonitrile), 2, 2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 4,4′-azobis(4-cyanovaleric acid), 2,2′-azobis(2-hydroxymethylpropionitrile), and 2,2′-azobis(2-(2-imidazolin-2-yl) propane) and the like.
Organic peroxides include, for example, benzoyl peroxide, t-butylperbenzoate, cumene hydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, Carbonate, t-butylperoxyneodecanoate, t-butylperoxybivalate, (3,5,5-trimethylhexanoyl)peroxide, dipropionylperoxide, diacetylperoxide and the like.
＜硬化剤（Ｂ）＞
　一実施形態において、粘着剤組成物は、さらに硬化剤（Ｂ）を含む。硬化剤を含むことで、凝集力を向上させ、保持力と曲面接着性とを実用レベルまで向上できる。硬化剤（Ｂ）は、例えば、イソシアネート系硬化剤、エポキシ系硬化剤、アジリジン系硬化剤、金属キレート系硬化剤、アミン系硬化剤、及びアミノ樹脂系硬化剤等が挙げられる。
　これらのなかでも、より優れた保持力と曲面接着性とを得られる点から、イソシアネート系硬化剤、エポキシ系硬化剤及び金属キレート系硬化剤からなる群より選ばれる少なくとも１種を使用することが好ましい。 <Curing agent (B)>
In one embodiment, the adhesive composition further contains a curing agent (B). By including a curing agent, cohesive force can be improved, and holding power and curved surface adhesion can be improved to a practical level. Curing agents (B) include, for example, isocyanate curing agents, epoxy curing agents, aziridine curing agents, metal chelate curing agents, amine curing agents, and amino resin curing agents.
Among these, at least one selected from the group consisting of isocyanate-based curing agents, epoxy-based curing agents, and metal chelate-based curing agents can be used in order to obtain better holding power and curved surface adhesion. preferable.
　イソシアネート系硬化剤は、例えば、トリ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、イソホロンジイソシアネート、キシリレンジイソシアネート、水添キシリレンジイソシアネート、ジフェニルメタンジイソシアネート、水添ジフェニルメタンジイソシアネート、テトラメチルキシリレンジイソシアネート、ナフタレンジイソシアネート、トリフェニルメタントリイソシアネート、及びポリメチレンポリフェニルイソシアネート等のジイソシアネートと、トリメチロールプロパン等のポリオール化合物とのアダクト体、そのビュレット体、及びそのイソシアヌレート体、並びに上記ジイソシアネートと、ポリエーテルポリオール、ポリエステルポリオール、アクリルポリオール、ポリブタジエンポリオール、及びポリイソプレンポリオール等のうちのいずれかのポリオールとのアダクト体などの、分子内に３個以上のイソシアネート基を有する化合物；
　トリ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、イソホロンジイソシアネート、キシリレンジイソシアネート、水添キシリレンジイソシアネート、ジフェニルメタンジイソシアネート、水添ジフェニルメタンジイソシアネート、テトラメチルキシリレンジイソシアネート、ナフタレンジイソシアネート、トリフェニルメタントリイソシアネート、及びポリメチレンポリフェニルイソシアネート等のジイソシアネート、並びにヘキサメチレンジイソシアネートのアロファネート体等の、分子内に２個のイソシアネート基を有する化合物；等が挙げられる。
　これらのなかでも、トリ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が、粘着物性を容易に調整できるため好ましい。なお、イソシアネート基の個数は平均個数である。 Isocyanate-based curing agents include, for example, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate. Isocyanate, adducts of diisocyanates such as polymethylene polyphenyl isocyanate and polyol compounds such as trimethylolpropane, burettes thereof, isocyanurates thereof, and the diisocyanates, polyether polyols, polyester polyols, acrylic polyols, Compounds having 3 or more isocyanate groups in the molecule, such as polybutadiene polyols, polyisoprene polyol adducts with any of polyols;
tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and polymethylene polyphenyl isocyanate compounds having two isocyanate groups in the molecule, such as diisocyanates such as hexamethylene diisocyanate and allophanate forms of hexamethylene diisocyanate;
Among these, the trimethylolpropane adduct of tolylene diisocyanate is preferable because the adhesive properties can be easily adjusted. In addition, the number of isocyanate groups is the average number.
　エポキシ系硬化剤は、例えば、ビスフェノールＡ－エピクロロヒドリン型のエポキシ系樹脂、エチレングリコールジグリシジルエーテル、ポリエチレングリコールジグリシジルエーテル、グリセリンジグリシジルエーテル、グリセリントリグリシジルエーテル、１，６－ヘキサンジオールジグリシジルエーテル、トリメチロールプロパントリグリシジルエーテル、ジグリシジルアニリン、Ｎ，Ｎ，Ｎ'，Ｎ'－テトラグリシジル－ｍ－キシリレンジアミン、１、３－ビス（Ｎ、Ｎ'－ジグリシジルアミノメチル）シクロヘキサン、及びＮ，Ｎ，Ｎ'，Ｎ'－テトラグリシジルアミノフェニルメタン等が挙げられる。 Epoxy curing agents include, for example, bisphenol A-epichlorohydrin type epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diol. glycidyl ether, trimethylolpropane triglycidyl ether, diglycidylaniline, N,N,N',N'-tetraglycidyl-m-xylylenediamine, 1,3-bis(N,N'-diglycidylaminomethyl)cyclohexane , and N,N,N',N'-tetraglycidylaminophenylmethane.
　金属キレート系硬化剤は、例えば、アルミニウム、鉄、銅、亜鉛、スズ、チタン、ニッケル、アンチモン、マグネシウム、バナジウム、クロム、及びジルコニウムなどの多価金属と、アセチルアセトン又はアセト酢酸エチルとの配位化合物等が挙げられる。 Metal chelate-based curing agents are, for example, coordination compounds of polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium, and acetylacetone or ethyl acetoacetate. etc.
　硬化剤（Ｂ）のうち、イソシアネート系硬化剤の含有量は、アクリル系共重合体１００質量部に対して、０．１～３質量部であることが好ましい。エポキシ系硬化剤の含有量は、アクリル系共重合体１００質量部に対して、０．０１～０．５質量部であることが好ましい。金属キレート系硬化剤の含有量は、０．１～２質量部であることが好ましい。上記範囲の含有量で、硬化剤（Ｂ）を使用した場合、粘着力と保持力との両立が容易になる。 The content of the isocyanate-based curing agent in the curing agent (B) is preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the acrylic copolymer. The content of the epoxy curing agent is preferably 0.01 to 0.5 parts by mass with respect to 100 parts by mass of the acrylic copolymer. The content of the metal chelate curing agent is preferably 0.1 to 2 parts by mass. When the curing agent (B) is used in a content within the above range, it becomes easy to achieve both adhesive strength and holding power.
＜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。
　粘着付与樹脂は、例えば、ロジン系粘着付与樹脂、合成炭化水素系粘着付与樹脂、テルペン系粘着付与樹脂、及びテルペンフェノール系粘着付与樹脂等が挙げられ、このなかでも、ロジン系粘着付与樹脂、合成炭化水素系粘着付与樹脂、及びテルペンフェノール系粘着付与樹脂からなる群から選ばれる少なくとも１種を含むことが好ましい。これらの粘着付与樹脂を含むことで、粘着力をより向上できる。
　さらに、ロジン系粘着付与樹脂と合成炭化水素系粘着付与樹脂とを併用して用いることで、相溶性と、高極性被着体及び低極性被着体への粘着力の両立とが、より容易になるために好ましい。 <Tackifying resin>
In one embodiment, the adhesive composition may further comprise a tackifying resin.
Examples of tackifying resins include rosin-based tackifying resins, synthetic hydrocarbon-based tackifying resins, terpene-based tackifying resins, and terpene-phenol-based tackifying resins. It preferably contains at least one selected from the group consisting of hydrocarbon-based tackifying resins and terpene-phenol-based tackifying resins. By including these tackifying resins, the adhesive force can be further improved.
Furthermore, by using a rosin-based tackifying resin and a synthetic hydrocarbon-based tackifying resin in combination, it is easier to achieve both compatibility and adhesive strength to high-polarity adherends and low-polarity adherends. preferred to become
　ロジン系粘着付与樹脂は、ガムロジン、トール油ロジン、ウッドロジンの未変性ロジンをアルコールなどでエステル化したロジンエステル；未変性ロジンを変性した不均化ロジン、重合ロジン、水添ロジンなどの変性ロジン；これら変性ロジンをさらにアルコールなどでエステル化した不均化ロジンエステル、重合ロジンエステル、水添ロジンエステルなどの変性ロジンエステル、及び上記未変性ロジンにフェノールを付加したロジンフェノール等が好ましい。
　これらのなかでも、粘着力及び透明性がより向上することから、ロジンエステル、及び変性ロジンエステルが好ましい。なお、ロジンエステル及び変性ロジンエステルには、エステル化に用いたアルコールなどの水酸基の一部が未反応で残存している場合もある。エステル化に用いるアルコールは、メタノールなどの単官能アルコール、エチレングリコールなどの２官能アルコール、グリセリンなどの３官能アルコール、及びペンタエリスリトールなどの４官能アルコールが挙げられる。アクリル系共重合体との相溶性を考慮すると３官能以下のアルコールが好ましい。 Rosin-based tackifying resins include rosin esters obtained by esterifying unmodified rosins such as gum rosin, tall oil rosin, and wood rosin with alcohol; Disproportionated rosin esters obtained by further esterifying these modified rosins with alcohol, modified rosin esters such as polymerized rosin esters and hydrogenated rosin esters, and rosin phenol obtained by adding phenol to the unmodified rosin are preferred.
Among these, rosin esters and modified rosin esters are preferred because they further improve adhesive strength and transparency. In the rosin ester and the modified rosin ester, some hydroxyl groups of the alcohol used for esterification may remain unreacted. Examples of alcohols used for esterification include monofunctional alcohols such as methanol, bifunctional alcohols such as ethylene glycol, trifunctional alcohols such as glycerin, and tetrafunctional alcohols such as pentaerythritol. Considering the compatibility with the acrylic copolymer, tri- or less functional alcohols are preferred.
　合成炭化水素系粘着剤付与樹脂は、例えば、クマロン系樹脂、クマロンインデン系樹脂、スチレン系樹脂、キシレン系樹脂、フェノール系樹脂、石油系樹脂等が挙げられる。これらのなかでも、アクリル系重合体との相溶性が良く粘着性能がより向上できる点から、スチレン系樹脂が好ましい。 Synthetic hydrocarbon-based tackifying resins include, for example, coumarone-based resins, coumarone-indene-based resins, styrene-based resins, xylene-based resins, phenol-based resins, and petroleum-based resins. Among these, styrene-based resins are preferable because they have good compatibility with acrylic polymers and can further improve adhesive performance.
　一実施形態において、粘着剤組成物で用いられる粘着付与樹脂としては、高極性被着体及び低極性被着体に対する粘着力を両立するという観点で、ロジン系粘着付与樹脂、及び合成炭化水素系粘着付与樹脂が好ましい。合成炭化水素系粘着付与樹脂がより好ましい。 In one embodiment, the tackifying resin used in the pressure-sensitive adhesive composition includes a rosin-based tackifying resin and a synthetic hydrocarbon-based resin from the viewpoint of achieving both high-polarity adherend and low-polarity adherend strength. Tackifying resins are preferred. Synthetic hydrocarbon-based tackifying resins are more preferred.
　粘着付与樹脂の軟化点は、８０℃以上が好ましく、９０℃以上がより好ましい。また、軟化点の上限は、１７０℃が好ましく、１６０℃がより好ましく、１５５℃がさらに好ましい。粘着付与樹脂の軟化点が８０～１７０℃である場合、粘着力と保持力とを高いレベルで両立し易くなる。なお、軟化点は、ＪＩＳＫ５９０２に規定されている乾球法にしたがって測定した軟化温度である。 The softening point of the tackifying resin is preferably 80°C or higher, more preferably 90°C or higher. Moreover, the upper limit of the softening point is preferably 170°C, more preferably 160°C, and even more preferably 155°C. When the softening point of the tackifier resin is 80 to 170° C., it becomes easy to achieve both high levels of adhesive strength and holding power. The softening point is the softening temperature measured according to the dry bulb method specified in JISK5902.
　粘着付与樹脂は、共重合体（Ａ）１００質量部に対して、１０～５０質量部の割合で使用することが好ましく、１５～４０質量部がより好ましい。粘着付与樹脂を１０～５０質量部の割合で使用した場合、粘着力、凝集力、及び曲面接着性をより容易に両立することができる。 The tackifying resin is preferably used in a proportion of 10 to 50 parts by mass, more preferably 15 to 40 parts by mass, per 100 parts by mass of the copolymer (A). When the tackifying resin is used in a proportion of 10 to 50 parts by mass, it is possible to more easily achieve both adhesive strength, cohesive strength, and curved surface adhesiveness.
＜ポリオレフィン＞
　一実施形態において、粘着剤組成物は、さらにポリオレフィンを含むことができる。粘着剤組成物がポリオレフィンを含む場合、ポリオレフィン製の低極性被着体に対する粘着力を向上できる。 <Polyolefin>
In one embodiment, the pressure-sensitive adhesive composition can further include a polyolefin. When the pressure-sensitive adhesive composition contains polyolefin, the adhesive strength to low-polar adherends made of polyolefin can be improved.
　ポリオレフィンは、塩素化されているポリオレフィン（以下、塩素化ポリオレフィン）と、塩素化されていないポリオレフィン（以下、非塩素化ポリオレフィン）に分類される。
　塩素化ポリオレフィンは、例えば、塩素化ポリプロピレン、酸変性塩素化ポリプロピレン、アクリル変性塩素化ポリプロピレン、塩素化ポリエチレン、及び塩素化エチレン酢酸ビニルコポリマー等が挙げられる。これらのなかでも、溶解性に優れ、かつポリオレフィン製被着体への粘着力が高いという観点から、塩素化ポリプロピレン、酸変性塩素化ポリプロピレン、及びアクリル変性塩素化ポリプロピレンが好ましい。塩素化ポリプロピレンがより好ましい。塩素化ポリオレフィンにおける塩素含有率は、ポリオレフィン製の低極性被着体に対する粘着力の向上効果が高いという観点から、２０％以上～４５％以下が好ましく、２８％以上～４５％以下がより好ましい。 Polyolefins are classified into chlorinated polyolefins (hereinafter referred to as chlorinated polyolefins) and non-chlorinated polyolefins (hereinafter referred to as non-chlorinated polyolefins).
Chlorinated polyolefins include, for example, chlorinated polypropylene, acid-modified chlorinated polypropylene, acrylic-modified chlorinated polypropylene, chlorinated polyethylene, and chlorinated ethylene-vinyl acetate copolymer. Among these, chlorinated polypropylene, acid-modified chlorinated polypropylene, and acrylic-modified chlorinated polypropylene are preferable from the viewpoint of excellent solubility and high adhesion to polyolefin adherends. Chlorinated polypropylene is more preferred. The chlorine content in the chlorinated polyolefin is preferably 20% or more and 45% or less, more preferably 28% or more and 45% or less, from the viewpoint that the effect of improving the adhesive strength to low-polar polyolefin adherends is high.
　非塩素化ポリオレフィンとしては、例えば、ポリエチレン、ポリプロピレン、αオレフィン－プロピレンコポリマー、エチレン－酢酸ビニルコポリマー、ポリブテン、マレイン化ポリプロピレン、マレイン化ポリブテン、ポリブタジエン及びその水素化物、ポリイソプレン及びその水素化物、マレイン化ポリブタジエン、マレイン化ポリイソプレン、ポリブタジエンポリオール及びその水素化物、ポリイソプレンポリオール及びその水素化物、並びにプロセスオイル及び流動パラフィン等の潤滑油、等が挙げられる。
　これらのなかでも、溶解性に優れ、かつポリオレフィン製被着体への粘着力が高いという観点から、αオレフィン－ポリプロピレンコポリマー、マレイン化ポリプロピレン、ポリブテン、及び潤滑油が好ましい。潤滑油としては、パラフィン系潤滑油、ナフテン系潤滑油等が好ましい。粘着剤組成物で用いられるポリオレフィンとして、溶解性に優れ、かつポリオレフィン製被着体への粘着力が高いという観点から、塩素化ポリオレフィンが好ましい。そのなかでも、塩素化ポリプロピレンがより好ましい。 Non-chlorinated polyolefins include, for example, polyethylene, polypropylene, α-olefin-propylene copolymer, ethylene-vinyl acetate copolymer, polybutene, maleated polypropylene, maleated polybutene, polybutadiene and its hydrides, polyisoprene and its hydrides, maleated polybutadiene, maleated polyisoprene, polybutadiene polyol and its hydride, polyisoprene polyol and its hydride, process oil and lubricating oils such as liquid paraffin, and the like.
Among these, α-olefin-polypropylene copolymer, maleated polypropylene, polybutene, and lubricating oil are preferable from the viewpoint of excellent solubility and high adhesion to polyolefin adherends. As the lubricating oil, paraffinic lubricating oil, naphthenic lubricating oil and the like are preferable. As the polyolefin used in the pressure-sensitive adhesive composition, chlorinated polyolefin is preferable from the viewpoint of excellent solubility and high adhesive strength to polyolefin adherends. Among them, chlorinated polypropylene is more preferable.
　ポリオレフィンは、共重合体（Ａ）の１００質量部に対して、０．０１～１０質量部の割合で使用することが好ましく、０．０２～５質量部がより好ましい。ポリオレフィンを０．０１～１０質量部の割合で使用した場合、低極性被着体に対する粘着力、凝集力、及び曲面接着性をより容易に両立することができる。 The polyolefin is preferably used in a proportion of 0.01 to 10 parts by mass, more preferably 0.02 to 5 parts by mass, per 100 parts by mass of the copolymer (A). When polyolefin is used in a proportion of 0.01 to 10 parts by mass, it is possible to more easily achieve both adhesive strength, cohesive strength, and curved surface adhesion to low-polar adherends.
　粘着剤組成物は、さらに、任意成分として、難燃助剤、耐熱安定剤、耐候安定剤、老化防止剤、紫外線吸収剤、レベリング剤、帯電防止剤、スリップ剤、アンチブロッキング剤、防曇剤、滑剤、染料、ワックス、乳剤、磁性体、および誘電特性調整剤を含むことができる。 The pressure-sensitive adhesive composition further contains, as optional components, a flame retardant auxiliary, a heat stabilizer, a weather stabilizer, an anti-aging agent, an ultraviolet absorber, a leveling agent, an antistatic agent, a slip agent, an anti-blocking agent, and an anti-fogging agent. , lubricants, dyes, waxes, emulsions, magnetics, and dielectric property modifiers.
２．粘着シート
　本発明の他の実施形態は、上記実施形態の粘着剤組成物から形成した粘着剤層を備える粘着シートに関する。
　一実施形態において、粘着シートは、基材と、上記実施形態の粘着剤組成物（以下、粘着剤と称する場合もある）から形成した粘着剤層とを備えていることが好ましい。また、別の態様として、芯材の両面に粘着剤層を有する両面粘着シート、又は、基材及び芯材を有さずに、粘着剤層のみで構成されたキャスト粘着シートも好ましい。上記粘着剤層は、粘着剤を基材上に塗工し、乾燥することで形成できる。別法として、粘着剤を剥離性シート上に塗工し、乾燥して粘着剤層を形成した後、基材を貼り合わせることによって形成できる。なお、粘着剤層の基材と接しない面に、通常、剥離性シートを貼り合わせて保管する。 2. Adhesive Sheet Another embodiment of the present invention relates to an adhesive sheet provided with an adhesive layer formed from the adhesive composition of the above embodiment.
In one embodiment, the pressure-sensitive adhesive sheet preferably includes a substrate and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (hereinafter sometimes referred to as pressure-sensitive adhesive) of the above-described embodiment. Further, as another aspect, a double-sided pressure-sensitive adhesive sheet having pressure-sensitive adhesive layers on both sides of a core material, or a cast pressure-sensitive adhesive sheet having only a pressure-sensitive adhesive layer without a substrate and a core material are preferable. The pressure-sensitive adhesive layer can be formed by applying a pressure-sensitive adhesive onto a substrate and drying it. Alternatively, it can be formed by coating a release sheet with a pressure-sensitive adhesive, drying it to form a pressure-sensitive adhesive layer, and then laminating the substrate. A peelable sheet is usually adhered to the surface of the pressure-sensitive adhesive layer that does not come into contact with the base material, and the adhesive layer is stored.
　上記粘着剤を塗工する際に、溶液重合で先に説明した溶剤を添加して、粘度を調整することができる。 When applying the adhesive, the viscosity can be adjusted by adding the solvent previously described in the solution polymerization.
　上記基材は、例えば、セロハン、プラスチック、ゴム、発泡体、布帛、ゴムびき布、樹脂含浸布、ガラス、及び木材等が好ましい。基材の形状は、板状及びフィルム状を選択できるが、取り扱いが容易であるフィルム状が好ましい。基材は、１種を単独で使用しても、又は２種以上を組合せた積層体を使用できる。 The base material is preferably cellophane, plastic, rubber, foam, fabric, rubberized fabric, resin-impregnated fabric, glass, wood, or the like. The shape of the base material can be selected from a plate shape and a film shape, but the film shape is preferable because it is easy to handle. As for the base material, one type can be used alone, or a laminate in which two or more types are combined can be used.
　上記プラスチックは、例えば、ポリビニルアルコール、トリアセチルセルロース、ポリプロピレン、ポリエチレン、ポリシクロオレフィン、及びエチレン－酢酸ビニル共重合体等のポリオレフィン、ポリエチレンテレフタレート、ポリブチレンテレフタレート、及びポリエチレンナフタレート等のポリエステル、ポリカーボネート、ポリノルボルネン、ポリアリレート、ポリアクリル、ポリフェニレンサルファイドム、ポリスチレン、ポリアミド、及びポリイミド、等が挙げられる。 The above plastics include, for example, polyvinyl alcohol, triacetyl cellulose, polypropylene, polyethylene, polycycloolefins, polyolefins such as ethylene-vinyl acetate copolymer, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, polycarbonates, polynorbornene, polyarylate, polyacryl, polyphenylene sulfide, polystyrene, polyamide, polyimide, and the like.
　粘着剤の塗工方法は、特に制限はなく、例えば、マイヤーバー、アプリケーター、刷毛、スプレー、ローラー、グラビアコーター、ダイコーター、リップコーター、コンマコーター、ナイフコーター、リバースコ－ター、及びスピンコーター等が挙げられる。塗工に際して、乾燥工程を行うことが好ましい。
　乾燥装置は、特に制限はなく、例えば、熱風乾燥機、赤外線ヒーター、及び減圧法等が挙げられる。乾燥温度は、通常６０～１６０℃程度である。
　粘着剤層の厚さは、１～２０μｍが好ましく、１～１５μｍがより好ましく、１～１０μｍであることがさらに好ましい。上記実施形態の粘着剤組成物は、１～２０μｍといった薄膜であっても、粘着力、保持力、及び曲面接着性の全てについて、優れた特性を得ることができる。 The method of applying the adhesive is not particularly limited. mentioned. It is preferable to carry out a drying process during coating.
The drying device is not particularly limited, and examples thereof include hot air dryers, infrared heaters, decompression methods, and the like. The drying temperature is usually about 60 to 160°C.
The thickness of the adhesive layer is preferably 1 to 20 μm, more preferably 1 to 15 μm, even more preferably 1 to 10 μm. The pressure-sensitive adhesive composition of the above embodiment can obtain excellent properties in terms of all of adhesive strength, holding power, and curved surface adhesion, even when the thickness is as thin as 1 to 20 μm.
　本発明の一実施形態である粘着シートは、被着体を選ばずに、様々な用途で使用できる。被着体は、ポリオレフィンなどのプラスチック、ガラス、ダンボール、及び金属等といった、高極性から低極性にわたる様々な被着体であってよい。 The pressure-sensitive adhesive sheet, which is one embodiment of the present invention, can be used for various purposes regardless of the adherend. The adherend can be a variety of adherends ranging from highly polar to less polar, such as plastics such as polyolefins, glass, cardboard, and metals.
　以下、実施例によって本発明をより具体的に説明するが、本発明は実施例に限定されるものではない。なお、実施例に記載する「部」は「質量部」を、「％」は「質量％」を意味する。また、表中の配合量は、質量部であり、溶剤以外は、不揮発分換算値である。表中の空欄は、配合がないことを表す。 The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the examples. In addition, "part" described in an Example means "mass part", and "%" means "mass %." In addition, the compounding amount in the table is in parts by mass, and values other than the solvent are converted to non-volatile matter. A blank column in the table indicates that there is no compounding.
　なお、共重合体の重量平均分子量（Ｍｗ）と酸価の測定は、次の方法により行なった。
＜重量平均分子量（Ｍｗ）の測定＞
　重量平均分子量の測定はＧＰＣを用いた。ＧＰＣは溶媒（ＴＨＦ；テトラヒドロフラン）に溶解した物質をその分子サイズの差によって分離定量する液体クロマトグラフィーであり、重量平均分子量の決定はポリスチレン換算で行った。
　装置名：島津製作所製、ＬＣ－ＧＰＣシステム「Ｐｒｏｍｉｎｅｎｃｅ」
　カラム：東ソー社製ＧＭＨＸＬ４本、東ソー社製ＨＸＬ-Ｈ１本を直列に連結した。
　移動相溶媒：テトラヒドロフラン
　流量：１．０ｍｌ／ｍｉｎ
　カラム温度：４０℃ The weight average molecular weight (Mw) and acid value of the copolymer were measured by the following methods.
<Measurement of weight average molecular weight (Mw)>
GPC was used to measure the weight average molecular weight. GPC is liquid chromatography for separating and quantifying a substance dissolved in a solvent (THF; tetrahydrofuran) based on the difference in molecular size, and the weight average molecular weight was determined in terms of polystyrene.
Apparatus name: Shimadzu Corporation, LC-GPC system "Prominence"
Column: 4 columns of GMHXL manufactured by Tosoh Corporation and 1 column of HXL-H manufactured by Tosoh Corporation were connected in series.
Mobile phase solvent: Tetrahydrofuran Flow rate: 1.0 ml/min
Column temperature: 40°C
＜酸価の測定＞
　共栓三角フラスコ中に試料１ｇを精密に量り採り、トルエン／エタノール（容量比：トルエン／エタノール＝２／１）混合液１００ｍｌを加えて、上記試料を溶解した後、０．１Ｎ－アルコール性水酸化カリウム溶液にて滴定した。酸価（単位：ｍｇＫＯＨ／ｇ）は、次式により求めた。なお、酸価は、乾燥した試料の数値とした。
　酸価＝｛（５．６１×ａ×Ｆ）／Ｓ｝／（不揮発分濃度／１００）
　Ｓ：試料の採取量（ｇ）
　ａ：０．１Ｎ－アルコール性水酸化カリウム溶液の消費量（ｍｌ）
　Ｆ：０．１Ｎ－アルコール性水酸化カリウム溶液のファクター <Measurement of acid value>
Accurately weigh 1 g of sample into a stoppered Erlenmeyer flask, add 100 ml of toluene/ethanol (volume ratio: toluene/ethanol = 2/1) mixture, dissolve the above sample, and add 0.1N-alcoholic water. It was titrated with a potassium oxide solution. The acid value (unit: mgKOH/g) was determined by the following formula. In addition, the acid value was the numerical value of the dried sample.
Acid value = {(5.61 × a × F) / S} / (non-volatile content / 100)
S: Sample collection amount (g)
a: consumption of 0.1N-alcoholic potassium hydroxide solution (ml)
F: Factor of 0.1N-alcoholic potassium hydroxide solution
（共重合体（Ａ－１）の製造）
　撹拌機、温度計、還流冷却管、滴下装置、及び窒素導入管を備えた反応容器（以下、単に「反応容器」と記述する。）に、窒素雰囲気下、２－エチルヘキシルアクリレート２０部、ｎ－ブチルアクリレート７０．８部、イソボルニルアクリレート５部、２－ヒドロキシエチルアクリレート０．２部、ω－カルボキシポリカプロラクトンモノアクリレート（東亞合成社製、アロニックスＭ－５３００）２部、２－アクリロイルオキシエチルコハク酸（共栄社化学社製、ＨＯＡ－ＭＳ（Ｎ））２部、酢酸エチル７０部、及び２，２'－アゾビスイソブチロニトリル０．０１５部をそれぞれ仕込んだ。これらを撹拌しながら加熱を行い、重合反応の開始を確認して、還流温度で２時間反応した。次いで、２，２'－アゾビスイソブチロニトリル０．０３部を反応溶液に添加し、６時間反応を継続した。その後、反応容器を冷却し、酢酸エチル１３０部を加え、重量平均分子量９０万の共重合体（Ａ－１）溶液を得た。 (Production of copolymer (A-1))
A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen inlet tube (hereinafter simply referred to as "reaction vessel") was charged with 20 parts of 2-ethylhexyl acrylate, n- 70.8 parts of butyl acrylate, 5 parts of isobornyl acrylate, 0.2 parts of 2-hydroxyethyl acrylate, ω-carboxypolycaprolactone monoacrylate (manufactured by Toagosei Co., Ltd., Aronix M-5300) 2 parts, 2-acryloyloxyethyl 2 parts of succinic acid (HOA-MS (N), manufactured by Kyoeisha Chemical Co., Ltd.), 70 parts of ethyl acetate, and 0.015 part of 2,2'-azobisisobutyronitrile were charged respectively. These were heated while being stirred, and after confirming the initiation of the polymerization reaction, the reaction was carried out at the reflux temperature for 2 hours. Then, 0.03 part of 2,2'-azobisisobutyronitrile was added to the reaction solution, and the reaction was continued for 6 hours. After that, the reaction vessel was cooled, and 130 parts of ethyl acetate was added to obtain a copolymer (A-1) solution having a weight average molecular weight of 900,000.
（共重合体（Ａ－２～１１、Ａ’－１～４）の製造）
　モノマーの種類及び配合量を表１に記載のとおりに変えた以外は、共重合体（Ａ－１）と同様の方法によって、共重合体（Ａ－２～１１、Ａ’－１～４）を得た。 (Production of copolymers (A-2 to 11, A'-1 to 4))
Copolymers (A-2 to 11, A'-1 to 4) were prepared in the same manner as for copolymer (A-1), except that the types and amounts of monomers were changed as shown in Table 1. got
（共重合体（Ａ－１２）の製造）
　撹拌機、温度計、還流冷却管、滴下装置、及び窒素導入管を備えた反応容器（以下、単に「反応容器」と記述する。）に、窒素雰囲気下、２－エチルヘキシルアクリレート２０部、ｎ－ブチルアクリレート７０．８部、イソボルニルアクリレート５部、２－ヒドロキシエチルアクリレート０．２部、２－アクリロイルオキシエチルコハク酸（共栄社化学社製、ＨＯＡ－ＭＳ（Ｎ））４部、酢酸エチル３５部、メチルエチルケトン３５部、２，２'－アゾビスイソブチロニトリル０．０１５部をそれぞれ仕込んだ。これらを撹拌しながら加熱を行い、重合反応の開始を確認して、還流温度で２時間反応した。次いで、２，２'－アゾビスイソブチロニトリル０．０３部を反応溶液に添加し、６時間反応を継続した。その後、反応容器を冷却し、酢酸エチル１３０部を加え、重量平均分子量４０万の共重合体（Ａ－１２）溶液を得た。 (Production of copolymer (A-12))
A reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, a dropping device, and a nitrogen inlet tube (hereinafter simply referred to as "reaction vessel") was charged with 20 parts of 2-ethylhexyl acrylate, n- 70.8 parts of butyl acrylate, 5 parts of isobornyl acrylate, 0.2 parts of 2-hydroxyethyl acrylate, 4 parts of 2-acryloyloxyethyl succinic acid (manufactured by Kyoeisha Chemical Co., Ltd., HOA-MS (N)), 35 parts of ethyl acetate 35 parts of methyl ethyl ketone and 0.015 part of 2,2'-azobisisobutyronitrile were charged. These were heated while being stirred, and after confirming the initiation of the polymerization reaction, the reaction was carried out at the reflux temperature for 2 hours. Then, 0.03 part of 2,2'-azobisisobutyronitrile was added to the reaction solution, and the reaction was continued for 6 hours. After that, the reaction vessel was cooled, and 130 parts of ethyl acetate was added to obtain a copolymer (A-12) solution having a weight average molecular weight of 400,000.
Figure JPOXMLDOC01-appb-T000009
Figure JPOXMLDOC01-appb-T000009
　表１の略号を以下に記載する。
　２ＥＨＡ：２－エチルヘキシルアクリレート
　ＢＡ：ｎ－ブチルアクリレート
　ＣＨＡ：シクロヘキシルアクリレート
　ＩＢＸＡ：イソボルニルアクリレート
　ＤＣＰＡ：ジシクロペンタニルアクリレート
　Ｍ－５３００：ω－カルボキシポリカプロラクトンモノアクリレート（東亞合成社製、アロニックスＭ－５３００）
　β－ＣＥＡ：β－カルボキシエチルアクリレート（ダイセル・オルネクス者製、β－ＣＥＡ）
　ＨＯＡ－ＭＳ（Ｎ）：２－アクリロイルオキシエチルコハク酸（共栄社化学社製、ＨＯＡ－ＭＳ（Ｎ））
　ＨＯＡ－ＨＨ：２－アクリロイルオキシエチルヘキサヒドロフタル酸（共栄社化学社製、ライトアクリレートＨＯＡ－ＨＨ）
　ＡＡ：アクリル酸
　ＨＥＡ：２－ヒドロキシエチルアクリレート Abbreviations in Table 1 are listed below.
2EHA: 2-ethylhexyl acrylate BA: n-butyl acrylate CHA: cyclohexyl acrylate IBXA: isobornyl acrylate DCPA: dicyclopentanyl acrylate M-5300: ω-carboxypolycaprolactone monoacrylate (manufactured by Toagosei Co., Ltd., Aronix M-5300 )
β-CEA: β-carboxyethyl acrylate (β-CEA manufactured by Daicel Ornex)
HOA-MS (N): 2-acryloyloxyethyl succinic acid (manufactured by Kyoeisha Chemical Co., Ltd., HOA-MS (N))
HOA-HH: 2-acryloyloxyethylhexahydrophthalic acid (manufactured by Kyoeisha Chemical Co., Ltd., light acrylate HOA-HH)
AA: acrylic acid HEA: 2-hydroxyethyl acrylate
Ｉ．粘着剤組成物、粘着シートの作製
（実施例１）
　共重合体（Ａ－１）１００部に対して、硬化剤としてトリ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１．０部（不揮発分換算）、ロジン系粘着付与樹脂であるペンセルＤ－１２５（荒川化学社製）１０部、合成炭化水素系粘着付与樹脂であるＦＴＲ６１００（三井化学社製）１０部、及びポリオレフィンであるスーパークロン３６０Ｔ（日本製紙社製）１部、をそれぞれ配合し、さらに溶剤として酢酸エチルを加えて、不揮発分を３０％に調整して、粘着剤組成物を得た。 I. Preparation of adhesive composition and adhesive sheet (Example 1)
Per 100 parts of the copolymer (A-1), 1.0 parts of trimethylolpropane adduct of tolylene diisocyanate as a curing agent (in terms of non-volatile content), a rosin-based tackifying resin Pencel D-125 (Arakawa Chemical Co., Ltd.), 10 parts of FTR6100 (manufactured by Mitsui Chemicals, Inc.), which is a synthetic hydrocarbon-based tackifying resin, and 1 part of Superchron 360T (manufactured by Nippon Paper Industries, Ltd.), which is a polyolefin, are blended, and acetic acid is used as a solvent. Ethyl was added to adjust the non-volatile content to 30% to obtain an adhesive composition.
　得られた粘着剤組成物を、厚さ３８μｍの剥離性シート（ポリエチレンテレフタレート製）上に、乾燥後の厚さが１０μｍになるようにコンマコーターを用いて塗工を行い、１００℃で２分間乾燥することで粘着剤層を形成した。次いで、この粘着剤層に、厚さ２５μｍの基材（ポリエチレンテレフタレート製、以下、ＰＥＴシートという）を貼り合せ、温度２３℃、相対湿度５０％の条件で、１週間熟成することによって、「剥離性シート／粘着剤層／ＰＥＴシート」の構成を有する粘着シートを得た。 The resulting pressure-sensitive adhesive composition was coated on a release sheet (made of polyethylene terephthalate) having a thickness of 38 μm using a comma coater so that the thickness after drying was 10 μm, and the composition was heated at 100° C. for 2 minutes. An adhesive layer was formed by drying. Next, a 25 μm thick substrate (made of polyethylene terephthalate, hereinafter referred to as a PET sheet) is attached to this adhesive layer, and aged for 1 week at a temperature of 23 ° C. and a relative humidity of 50%. A pressure-sensitive adhesive sheet having a structure of "adhesive sheet/adhesive layer/PET sheet" was obtained.
（実施例２～２５、比較例１～４）
　組成と配合量を表２、３に記載のとおりに変更した以外は、実施例１と同様の方法により、実施例２～２５及び比較例１～４の粘着剤組成物及び粘着シートを得た。 (Examples 2 to 25, Comparative Examples 1 to 4)
The adhesive compositions and adhesive sheets of Examples 2 to 25 and Comparative Examples 1 to 4 were obtained in the same manner as in Example 1, except that the composition and blending amount were changed as shown in Tables 2 and 3. .
II．粘着シートの評価
　得られた粘着シートを以下の方法で評価した。結果を表２、３に示す。
（１）粘着力
　得られた粘着シートを幅２５ｍｍ及び縦１００ｍｍの大きさに準備した。２３℃相対湿度５０％雰囲気下、前記粘着シートから剥離性シートを剥がして露出した粘着剤層をステンレス（ＳＵＳ）板に貼り付け、２ｋｇロールで１往復圧着した。２４時間放置した後に引張試験機を用いて１８０度方向に３００ｍｍ／分の速度で引き剥がす１８０°ピール試験において粘着力を測定し、下記の評価基準に基づいて評価を行った。（ＪＩＳ Ｚ ０２３７：２０００に準拠）
（評価基準）
　Ａ：粘着力が１２Ｎ以上であり、非常に良好
　Ｂ：粘着力が１０Ｎ以上１２Ｎ未満であり、良好
　Ｃ：粘着力が６Ｎ以上１０N未満であり、実用可
　Ｄ：粘着力が６N未満であり、実用不可
　上記同様にポリプロピレン（ＰＰ）板に対して粘着力を測定し、下記の評価基準に基づいて評価を行った。
（評価基準）
　Ａ：粘着力が１２Ｎ以上であり、非常に良好
　Ｂ：粘着力が１０Ｎ以上１２Ｎ未満であり、良好
　Ｃ：粘着力が６Ｎ以上１０N未満であり、実用可
　Ｄ：粘着力が６N未満であり、実用不可 II. Evaluation of Adhesive Sheet The obtained adhesive sheet was evaluated by the following methods. Tables 2 and 3 show the results.
(1) Adhesive strength The obtained adhesive sheet was prepared in a size of 25 mm in width and 100 mm in length. In an atmosphere of 23° C. and a relative humidity of 50%, the peelable sheet was peeled off from the adhesive sheet, and the exposed adhesive layer was attached to a stainless steel (SUS) plate and crimped once with a 2 kg roll. After being left for 24 hours, the adhesive strength was measured in a 180° peel test in which a tensile tester was used to peel off at a speed of 300 mm/min in the direction of 180°, and evaluation was performed based on the following evaluation criteria. (Compliant with JIS Z0237:2000)
(Evaluation criteria)
A: Adhesive strength is 12 N or more, very good B: Adhesive strength is 10 N or more and less than 12 N, good C: Adhesive strength is 6 N or more and less than 10 N, practical D: Adhesive strength is less than 6 N, Impractical Adhesive strength was measured with respect to a polypropylene (PP) plate in the same manner as described above, and evaluation was performed based on the following evaluation criteria.
(Evaluation criteria)
A: Adhesive strength is 12 N or more, very good B: Adhesive strength is 10 N or more and less than 12 N, good C: Adhesive strength is 6 N or more and less than 10 N, practical D: Adhesive strength is less than 6 N, impractical
（２）保持力
　得られた粘着シートを幅２５ｍｍ及び長さ１００ｍｍの大きさに切り取り試料とした。次いで２３℃相対湿度５０％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、露出した粘着剤層の先端部幅２５ｍｍ及び長さ２５ｍｍ部分を研磨したステンレス（ＳＵＳ）板に貼着し、２ｋｇロールで１往復圧着した後、７０℃雰囲気で１ｋｇの荷重をかけ、７万秒保持した。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、粘着剤層とＳＵＳ板の接着先端部が、荷重により下にずれたｍｍ数を示す。評価基準を以下に示す。
（評価基準）
　Ａ：試料のずれが０．０５ｍｍ未満、非常に良好
　Ｂ：試料のずれが０．０５ｍｍ以上０．２ｍｍ未満であり、良好
　Ｃ：試料のずれが０．２ｍｍ以上で落下なし、実用可
　Ｄ：試料が落下、実用不可 (2) Holding power The obtained pressure-sensitive adhesive sheet was cut into a size of 25 mm in width and 100 mm in length to obtain a sample. Then, in an atmosphere of 23° C. and a relative humidity of 50%, the release sheet was peeled off from the sample according to JIS Z 0237, and the exposed 25 mm wide and 25 mm long tip portion of the adhesive layer was attached to a polished stainless steel (SUS) plate. After pressing once with a 2 kg roll, a load of 1 kg was applied in an atmosphere of 70° 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 drop, it indicates the number of millimeters by which the adhesive tip of the pressure-sensitive adhesive layer and the SUS plate was displaced downward due to the load. Evaluation criteria are shown below.
(Evaluation criteria)
A: Sample deviation is less than 0.05 mm, very good B: Sample deviation is 0.05 mm or more and less than 0.2 mm, good C: Sample deviation is 0.2 mm or more, no drop, practically acceptable D: Sample dropped, impractical
（３）曲面接着性
　得られた粘着シートを使用して、２３℃、相対湿度５０％の恒温恒湿室において、幅１５ｍｍ及び長さ２５ｍｍの測定試料を作製した。この測定試料から剥離シートを剥がし、露出した粘着剤層を、１０ｍｍφの円筒状ポリプロピレン（ＰＰ）樹脂の円周方向に貼り付け、７２時間放置した。その後、さらに８０℃雰囲気下で２４時間放置した。その後、貼り付けられた測定試料の末端部分の剥がれた状態を目視で観察し、下記基準で評価した。
（評価基準）
　Ａ：末端部分に剥がれがなく、非常に良好
　Ｂ：末端部分に剥がれが長さ３ｍｍ未満であり、良好
　Ｃ：末端部分の剥がれが長さ３ｍｍ以上８ｍｍ未満であり、実用可
　Ｄ：末端部分の剥がれが長さ８ｍｍ以上であり、実用不可 (3) Curved Surface Adhesiveness Using the obtained pressure-sensitive adhesive sheet, a measurement sample with a width of 15 mm and a length of 25 mm was prepared in a constant temperature and humidity chamber at 23° C. and a relative humidity of 50%. The release sheet was peeled off from this measurement sample, and the exposed adhesive layer was attached to a cylindrical polypropylene (PP) resin having a diameter of 10 mm in the circumferential direction, and left for 72 hours. After that, it was left in an atmosphere of 80° C. for 24 hours. After that, the peeled state of the end portion of the attached measurement sample was visually observed and evaluated according to the following criteria.
(Evaluation criteria)
A: No peeling at the end portion, very good B: Peeling at the end portion with a length of less than 3 mm, good C: Peeling at the end portion with a length of 3 mm or more and less than 8 mm, practically acceptable D: End portion Peeling is 8mm or more in length, impractical
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000010
Figure JPOXMLDOC01-appb-T000011
Figure JPOXMLDOC01-appb-T000011
　表２、３における略号を以下に記載する。
＜粘着付与樹脂＞
　Ｄ－１２５：ペンセルＤ－１２５（荒川化学社製、ロジン系粘着付与樹脂）
　ＦＴＲ６１００：ＦＴＲ６１００（三井化学社製、合成炭化水素系粘着付与樹脂（スチレン系粘着付与樹脂））
　Ｔ１１５：ＹＳポリスターＴ１１５（ヤスハラケミカル社製、テルペンフェノール系粘着付与樹脂）
　ＰＸ１０００：ＹＳレジンＰＸ１０００（ヤスハラケミカル社製、テルペン系粘着付与樹脂）
＜ポリオレフィン＞
　３６０Ｔ：スーパークロン３６０Ｔ（日本製紙社製、塩素化ポリプロピレン、塩素含有率３１％）
　９３０：スーパークロン９３０（日本製紙社製、塩素化ポリプロピレン、塩素含有率２１％）
＜硬化剤＞
　ＴＤＩ／ＴＭＰ：トリ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（不揮発分３７．５％）
　ＴＥＴＲＡＤ－Ｘ：Ｎ,Ｎ,Ｎ',Ｎ'－テトラグリシジル－ｍ－キシリレンジアミン（三菱ガス化学社製）
　アルミキレートＡ：アルミニウムトリスアセチルアセトネート（川研ファインケミカル社製）
　ケミタイトＰＺ－３３：トリメチロールプロパントリス［３－（アジリジン－１－イル）プロピオナート］（日本触媒社製） The abbreviations in Tables 2 and 3 are described below.
<Tackifying resin>
D-125: Pencel D-125 (manufactured by Arakawa Chemical Co., Ltd., rosin-based tackifying resin)
FTR6100: FTR6100 (manufactured by Mitsui Chemicals, synthetic hydrocarbon-based tackifying resin (styrene-based tackifying resin))
T115: YS Polyster T115 (manufactured by Yasuhara Chemical Co., Ltd., terpene phenol-based tackifying resin)
PX1000: YS resin PX1000 (manufactured by Yasuhara Chemical Co., Ltd., terpene-based tackifying resin)
<Polyolefin>
360T: Superchron 360T (manufactured by Nippon Paper Industries, chlorinated polypropylene, chlorine content 31%)
930: Superchron 930 (manufactured by Nippon Paper Industries, chlorinated polypropylene, chlorine content 21%)
<Curing agent>
TDI/TMP: Trimethylolpropane adduct of tolylene diisocyanate (37.5% non-volatile content)
TETRAD-X: N,N,N',N'-tetraglycidyl-m-xylylenediamine (manufactured by Mitsubishi Gas Chemical Company)
Aluminum chelate A: aluminum trisacetylacetonate (manufactured by Kawaken Fine Chemicals)
Chemitite PZ-33: trimethylolpropane tris[3-(aziridin-1-yl)propionate] (manufactured by Nippon Shokubai Co., Ltd.)
　表２、３に示すように、本発明の一実施形態である粘着シートは、高極性被着体であるステンレス板と低極性被着体であるポリプロピレン板の両方に対する粘着力に優れ、さらに保持力、及び曲面接着性にも優れていることが確認できた。これに対し、比較例の粘着シートでは、いずれかの評価項目が不良となっており、実用上問題があり、実用不可であることが分かる。 As shown in Tables 2 and 3, the pressure-sensitive adhesive sheet according to one embodiment of the present invention has excellent adhesion to both a stainless steel plate, which is a high-polarity adherend, and a polypropylene plate, which is a low-polarity adherend. It was confirmed that the strength and curved surface adhesiveness were also excellent. On the other hand, the pressure-sensitive adhesive sheets of the comparative examples were found to be unsatisfactory in any of the evaluation items, indicating that there is a problem in practical use and that they are not practical.

Claims (11)

  1. 　共重合体（Ａ）と硬化剤（Ｂ）とを含み、
    　前記共重合体（Ａ）は、炭素数４～１２のアルキル基を有するアルキル（メタ）アクリレート（ａ１）、反応性官能基を有さず、脂肪族環式構造を有する（メタ）アクリレート（ａ２）、及びカルボキシル基を有する（メタ）アクリレート（ａ３）を含有するモノマー混合物の共重合体であり、
    　前記カルボキシル基を有する（メタ）アクリレート（ａ３）は、一般式（１）で表される（メタ）アクリレート（ａ３－１）及び一般式（２）で表される（メタ）アクリレート（ａ３－２）の少なくともいずれかを含む、粘着剤組成物。
    Figure JPOXMLDOC01-appb-C000001
     （式中、Ｒ１は水素原子又はメチル基、ｍは２～１０の整数、ｎは１～５の整数を示す。）
    Figure JPOXMLDOC01-appb-C000002
     （式中、Ｒ２は水素原子又はメチル基、Ｒ３は２価の炭化水素基、ｐは１～５の整数を示す。）     including a copolymer (A) and a curing agent (B),
    The copolymer (A) includes an alkyl (meth)acrylate (a1) having an alkyl group having 4 to 12 carbon atoms, and a (meth)acrylate (a2) having no reactive functional group and having an aliphatic cyclic structure. ), and a copolymer of a monomer mixture containing a (meth)acrylate (a3) having a carboxyl group,
    The (meth)acrylate (a3) having a carboxyl group includes (meth)acrylate (a3-1) represented by general formula (1) and (meth)acrylate (a3-2) represented by general formula (2). ), a pressure-sensitive adhesive composition comprising at least one of
    Figure JPOXMLDOC01-appb-C000001
     (In the formula, R 1 is a hydrogen atom or a methyl group, m is an integer of 2 to 10, and n is an integer of 1 to 5.)
    Figure JPOXMLDOC01-appb-C000002
     (In the formula, R 2 is a hydrogen atom or a methyl group, R 3 is a divalent hydrocarbon group, and p is an integer of 1 to 5.)
  2. 　前記（メタ）アクリレート（ａ３）は、一般式（２）で表される（メタ）アクリレート（ａ３－２）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 (meth)acrylate (a3) contains a (meth)acrylate (a3-2) represented by general formula (2).
  3. 　前記共重合体（Ａ）は、酸価が０．１～２４．０ｍｇＫＯＨ／ｇの範囲にある、請求項１又は２に記載の粘着剤組成物。 The adhesive composition according to claim 1 or 2, wherein the copolymer (A) has an acid value in the range of 0.1 to 24.0 mgKOH/g.
  4. 　前記モノマー混合物が、さらに、水酸基を有する（メタ）アクリレート（ａ４）を含有する、請求項１～３のいずれか１項に記載の粘着剤組成物。 The pressure-sensitive adhesive composition according to any one of claims 1 to 3, wherein the monomer mixture further contains a (meth)acrylate (a4) having a hydroxyl group.
  5. 　前記硬化剤（Ｂ）は、イソシアネート系硬化剤、エポキシ系硬化剤、及び金属キレート系硬化剤からなる群より選ばれる少なくとも１種を含む、請求項１～４のいずれか１項に記載の粘着剤組成物。 The adhesive according to any one of claims 1 to 4, wherein the curing agent (B) contains at least one selected from the group consisting of an isocyanate curing agent, an epoxy curing agent, and a metal chelate curing agent. agent composition.
  6. 　さらに粘着付与樹脂を含み、前記粘着付与樹脂は、ロジン系粘着付与樹脂、合成炭化水素系粘着付与樹脂、及びテルペンフェノール系粘着付与樹脂からなる群より選ばれる少なくとも１種を含む、請求項１～５のいずれか１項に記載の粘着剤組成物。 Further comprising a tackifying resin, wherein the tackifying resin comprises at least one selected from the group consisting of rosin-based tackifying resins, synthetic hydrocarbon-based tackifying resins, and terpene-phenol-based tackifying resins, claims 1- 6. The adhesive composition according to any one of 5.
  7. 　さらにポリオレフィンを含む、請求項１～６のいずれか１項に記載の粘着剤組成物。 The pressure-sensitive adhesive composition according to any one of claims 1 to 6, further comprising polyolefin.
  8. 　前記アルキル（メタ）アクリレート（ａ１）の含有量は、前記モノマー混合物の全質量を基準として、７０～９９質量％である、請求項１～７のいずれか１項に記載の粘着剤組成物。 The pressure-sensitive adhesive composition according to any one of claims 1 to 7, wherein the content of said alkyl (meth)acrylate (a1) is 70 to 99% by mass based on the total mass of said monomer mixture.
  9. 　前記カルボキシル基を有する（メタ）アクリレート（ａ３）において、前記（メタ）アクリレート（ａ３－１）、及び前記（メタ）アクリレート（ａ３－２）以外の、その他カルボキシル基を有する（メタ）アクリレート（ａ３－３）の含有量は、前記カルボキシル基を有する（メタ）アクリレート（ａ３）の全質量を基準として、４３質量％以下である、請求項１～８のいずれか１項に記載の粘着剤組成物。 In the (meth)acrylate (a3) having a carboxyl group, (meth)acrylate (a3) having a carboxyl group other than the (meth)acrylate (a3-1) and the (meth)acrylate (a3-2) The content of -3) is 43% by mass or less based on the total mass of the (meth)acrylate (a3) having a carboxyl group, The pressure-sensitive adhesive composition according to any one of claims 1 to 8. thing.
  10. 　請求項１～９のいずれか１項に記載の粘着剤組成物から形成してなる粘着剤層を備えた、粘着シート。 A pressure-sensitive adhesive sheet comprising a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of claims 1 to 9.
  11. 　前記粘着剤層は、厚みが１～２０μｍである、請求項１０に記載の粘着シート。 The pressure-sensitive adhesive sheet according to claim 10, wherein the pressure-sensitive adhesive layer has a thickness of 1 to 20 µm.
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