WO2023080054A1 - 粘着材および粘着シート - Google Patents

粘着材および粘着シート Download PDF

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Publication number
WO2023080054A1
WO2023080054A1 PCT/JP2022/040153 JP2022040153W WO2023080054A1 WO 2023080054 A1 WO2023080054 A1 WO 2023080054A1 JP 2022040153 W JP2022040153 W JP 2022040153W WO 2023080054 A1 WO2023080054 A1 WO 2023080054A1
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Prior art keywords
meth
adhesive
sheet
acrylate
group
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PCT/JP2022/040153
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English (en)
French (fr)
Japanese (ja)
Inventor
幸男 白神
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Otsuka Chemical Co Ltd
Higashiyama Film Co Ltd
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Otsuka Chemical Co Ltd
Higashiyama Film Co Ltd
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Application filed by Otsuka Chemical Co Ltd, Higashiyama Film Co Ltd filed Critical Otsuka Chemical Co Ltd
Priority to KR1020247010762A priority Critical patent/KR20240087772A/ko
Priority to CN202280066183.XA priority patent/CN118055990A/zh
Priority to JP2023557989A priority patent/JPWO2023080054A1/ja
Publication of WO2023080054A1 publication Critical patent/WO2023080054A1/ja
Anticipated expiration legal-status Critical
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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
    • 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
    • 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

  • the present invention relates to an adhesive material and an adhesive sheet, and more particularly to an adhesive material and an adhesive sheet used for bonding one flexible member and another flexible member.
  • Adhesive materials are generally used to join the components that make up various displays and touch panels for televisions, mobile phones, smartphones, etc.
  • the adhesive material is provided, for example, in the form of a substrate-attached adhesive sheet having an adhesive layer on a supporting substrate, or a substrate-less adhesive sheet having no supporting substrate, and the members are bonded together.
  • Flexible displays include a foldable display that can be folded, a rollable display that can be rolled into a cylindrical shape, etc., and are expected to be used in mobile terminals such as smartphones and tablet terminals, and stationary displays that can be stored.
  • Patent Document 1 discloses one flexible member and another flexible member.
  • the (meth)acrylic copolymer is obtained by living radical polymerization, has a molecular weight distribution (Mw/Mn) of 3.0 or less, and has a Young's modulus of 10 kPa.
  • Adhesives are described which are characterized by a percentage of 60% or more.
  • An adhesive made of an adhesive composition containing a (meth)acrylic copolymer obtained by living radical polymerization has a lower adhesive strength than free radical polymerization. Therefore, although it is suitable for re-peelable applications such as process protection films, it is required to improve adhesive strength for non-re-peelable applications. For example, as an adhesive used for bonding a flexible member and another flexible member, even if it is repeatedly bent, the interface between the adhesive and the flexible member at the bent portion does not float or peel off. Therefore, it is required to improve not only resilience but also adhesive strength.
  • the present invention has been made in view of the above circumstances, and an object of the present invention is to provide an adhesive material that has excellent adhesive strength and excellent restorability.
  • the adhesive material of the present invention that can solve the above problems is a cured product of an adhesive composition containing (A) a (meth)acrylic copolymer having a crosslinkable functional group and (B) a crosslinking agent wherein the (A) (meth)acrylic copolymer is obtained by living radical polymerization, and the cured product is (X) a (meth)acrylic having a molecular weight of 500 or less compound, and the content of the (X) (meth)acrylic compound in the cured product is 60 mass ppm to 5000 mass ppm.
  • the adhesive material of the present invention has excellent adhesive strength and excellent restorability. Therefore, by using the adhesive material of the present invention for joining flexible members, it is possible to suppress the occurrence of lifting or peeling at the interface between the adhesive material and the flexible member at the bent portion even when the flexible members are repeatedly bent.
  • BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram of an example of the adhesive sheet of this invention.
  • BRIEF DESCRIPTION OF THE DRAWINGS It is a cross-sectional schematic diagram of an example of the flexible laminated member of this invention.
  • (meth)acrylic means “at least one of acrylic and methacrylic".
  • (Meth)acrylate means “at least one of acrylate and methacrylate”.
  • (Meth)acryloyl means “at least one of acryloyl and methacryloyl”.
  • a "vinyl monomer” refers to a monomer having a radically polymerizable carbon-carbon double bond in the molecule.
  • a “structural unit derived from a vinyl monomer” refers to a structural unit in which a radically polymerizable carbon-carbon double bond of a vinyl monomer is polymerized to form a carbon-carbon single bond.
  • the “structural unit derived from (meth)acrylate” refers to a structural unit in which the radically polymerizable carbon-carbon double bond of (meth)acrylate is polymerized to form a carbon-carbon single bond.
  • a “structural unit derived from a (meth)acrylic monomer” refers to a structural unit in which a radically polymerizable carbon-carbon double bond of a (meth)acrylic monomer is polymerized to form a carbon-carbon single bond.
  • the adhesive material of the present invention comprises a cured adhesive composition containing (A) a (meth)acrylic copolymer having a crosslinkable functional group and (B) a crosslinking agent. Then, the (A) (meth)acrylic copolymer is obtained by living radical polymerization, and the cured product is (X) a (meth)acrylic compound having a molecular weight of 500 or less (hereinafter simply “( X) (Meth)acrylic compound”), and the content of the (X) (meth)acrylic compound in the cured product is 60 mass ppm to 5000 mass ppm. do.
  • the adhesive (cured product of the adhesive composition) contains (X) a (meth)acrylic compound having a molecular weight of 500 or less.
  • the (X) (meth)acrylic compound is a compound having a (meth)acryloyl group.
  • the (X) (meth)acrylic compound has a molecular weight of 500 or less, preferably 300 or less, more preferably 250 or less. If the (X) (meth)acrylic compound has a molecular weight of 500 or less, the content can be easily adjusted in the step of forming the adhesive material, and the adhesive strength of the adhesive material can be improved.
  • the (X) (meth)acrylic compound preferably has a molecular weight of 70 or more, more preferably 100 or more, and still more preferably 150 or more. When the (X) (meth)acrylic compound has a molecular weight of 70 or more, it is possible to form an adhesive material having excellent adhesive strength and flexibility.
  • the (X) (meth)acrylic compound includes a (meth)acrylate having a linear alkyl group, a (meth)acrylate having a branched alkyl group, a (meth)acrylate having an alkoxy group, and a polyalkylene glycol structure.
  • Unit-containing (meth)acrylates, alicyclic hydrocarbon group-containing (meth)acrylates, aromatic group-containing (meth)acrylates, tertiary amino group-containing (meth)acrylates, (meth)acrylamides, etc. be done.
  • (meth)acrylates having a linear alkyl group (meth)acrylates having a branched alkyl group, (meth)acrylates having an alicyclic hydrocarbon group, (meth)acrylates having an aromatic group, and At least one selected from the group consisting of (meth)acrylamides is preferred.
  • the total content of the (meth)acrylate having a linear alkyl group and the (meth)acrylate having a branched alkyl group in the (X) (meth)acrylic compound is preferably 50% by mass or more, more preferably is 70% by mass or more, more preferably 90% by mass or more.
  • the (meth)acrylate having a straight-chain alkyl group is preferably a (meth)acrylate having a straight-chain alkyl group having 1 to 20 carbon atoms in the straight-chain alkyl group.
  • (Meth)acrylates having linear alkyl groups of 4 to 15 in number are more preferred.
  • Examples of (meth)acrylates having a linear alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, and n-hexyl (meth)acrylate.
  • n-octyl (meth)acrylate n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate and other linear alkyl (meth)acrylates esters.
  • the (meth)acrylate having a branched-chain alkyl group is preferably a (meth)acrylate having a branched-chain alkyl group having 3 to 20 carbon atoms in the branched-chain alkyl group. (Meth)acrylates with 3 to 10 branched alkyl groups are preferred.
  • Examples of (meth)acrylates having a branched alkyl group include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, 2 - (meth)acrylic acid branched chain alkyl esters such as ethylhexyl (meth)acrylate, isononyl (meth)acrylate and isodecyl (meth)acrylate.
  • Examples of (meth)acrylates having an alicyclic hydrocarbon group include (meth)acrylates having a cyclic alkyl group and (meth)acrylates having a polycyclic structure.
  • the (meth)acrylate having a cyclic alkyl group is preferably a (meth)acrylate having a cyclic alkyl group having 6 to 12 carbon atoms.
  • the cyclic alkyl group includes a cyclic alkyl group having a monocyclic structure (for example, a cycloalkyl group), and may have a chain portion.
  • (meth)acrylates having a cyclic alkyl group having a monocyclic structure include (meth)acrylic acid cyclic alkyl esters such as cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate. be able to.
  • the (meth)acrylate having an aromatic group is preferably a (meth)acrylate having an aromatic group having 6 to 12 carbon atoms.
  • the aromatic group include an aryl group, and may have a chain portion such as an alkylaryl group, an aralkyl group, an aryloxyalkyl group, and the like.
  • the (meth)acrylate having an aromatic group include a compound in which an aryl group is directly bonded to a (meth)acryloyloxy group, a compound in which an aralkyl group is directly bonded to a (meth)acryloyloxy group, and a (meth)acryloyloxy group.
  • a compound having an alkylaryl group directly bonded thereto may be mentioned.
  • the aryl group preferably has 6 to 12 carbon atoms.
  • the aralkyl group preferably has 6 to 12 carbon atoms.
  • the alkylaryl group preferably has 6 to 12 carbon atoms.
  • (Meth)acrylates having an aromatic group include benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate and the like.
  • the boiling point (760 mmHg) of the (X) (meth)acrylic compound is preferably 100°C or higher, more preferably 150°C or higher, still more preferably 200°C or higher, and preferably 500°C or lower, more preferably 400°C. 350° C. or less, more preferably 350° C. or less. If the boiling point is 100° C. or higher, an adhesive material having excellent adhesive strength and flexibility can be formed. It can improve the adhesive strength of the material.
  • Table 1 shows the boiling points (760 mmHg) of typical (meth)acrylic compounds.
  • the content of the (X) (meth)acrylic compound in the adhesive (cured product of the adhesive composition) is preferably 60 mass ppm or more, more preferably 70 mass ppm or more, and still more preferably 80 mass ppm or more. , preferably 5000 mass ppm or less, more preferably 1000 mass ppm or less, and even more preferably 500 mass ppm or less. If the content of the (X) (meth)acrylic compound is 60 mass ppm or more, the restorability and holding power will be better, and if it is 5000 mass ppm or less, the adhesive material will have excellent adhesive strength. .
  • the content of the (X) (meth)acrylic compound in the adhesive can be adjusted by adjusting the amount of the (meth)acrylic compound added to the adhesive composition.
  • the (X) (meth)acrylic compound may be added separately, or the unreacted monomer contained in the (A) (meth)acrylic copolymer solution described later may be added to (X) It may be used as a (meth)acrylic compound.
  • the adhesive composition forming the adhesive of the present invention contains (A) a (meth)acrylic copolymer having a crosslinkable functional group and (B) a crosslinker.
  • the adhesive composition contains (A) a (meth)acrylic copolymer having a crosslinkable functional group (hereinafter sometimes simply referred to as "(A) copolymer").
  • the (A) (meth)acrylic copolymer may be a copolymer having a structural unit derived from a (meth)acrylic monomer as a main component (50% by mass or more), other than the (meth)acrylic monomer.
  • the copolymer (A) can contain a structural unit derived from a vinyl monomer of
  • the content of the structural unit derived from the (meth)acrylic monomer in the copolymer (A) is preferably 80% by mass or more, more preferably 90% by mass or more, based on 100% by mass of the entire copolymer.
  • the copolymer (A) may be composed only of structural units derived from (meth)acrylic monomers.
  • the (A) copolymer is preferably a (meth)acrylate copolymer.
  • the (meth)acrylate copolymer may be a copolymer having a structural unit derived from (meth)acrylate as a main component (50% by mass or more), and is derived from a vinyl monomer other than (meth)acrylate. It can contain structural units.
  • the (meth)acrylate is an ester compound in which the hydrogen atom of the carboxy group of (meth)acrylic acid is substituted with an organic group.
  • the content of structural units derived from (meth)acrylate in the copolymer (A) is preferably 80% by mass or more, more preferably 90% by mass or more, based on 100% by mass of the entire copolymer.
  • the (A) copolymer has a crosslinkable functional group that reacts with the (B) crosslinker described later.
  • the crosslinkable functional group reacts with a crosslinkable point of the (B) crosslinking agent described later.
  • 1 type may be sufficient as the said crosslinkable functional group, and 2 or more types may be sufficient as it.
  • Examples of the crosslinkable functional group include one or more selected from the group consisting of a hydroxy group, a carboxy group and an epoxy group, preferably a hydroxy group and/or a carboxy group.
  • the total amount of crosslinkable functional groups per unit mass of the (A) copolymer is preferably 0.5 ⁇ mol/g or more, more preferably 5 ⁇ mol/g or more, still more preferably 10 ⁇ mol/g or more, and particularly preferably 15 ⁇ mol/g. /g or more, preferably 1500 ⁇ mol/g or less, more preferably 1000 ⁇ mol/g or less, still more preferably 700 ⁇ mol/g or less, and particularly preferably 500 ⁇ mol/g or less.
  • the total amount of the crosslinkable functional groups is 5 ⁇ mol/g or more, the durability of the obtained adhesive is excellent, and when it is 1500 ⁇ mol/g or less, the adhesion of the adhesive to the adherend is excellent.
  • the amount of carboxy groups per unit mass of the copolymer (A) is preferably 5 ⁇ mol/g or more, more preferably 50 ⁇ mol/g or more, and still more preferably 100 ⁇ mol. /g or more, particularly preferably 150 ⁇ mol/g or more, preferably 1500 ⁇ mol/g or less, more preferably 1000 ⁇ mol/g or less, still more preferably 700 ⁇ mol/g or less, and particularly preferably 500 ⁇ mol/g or less.
  • the hydroxy group per unit mass of the (A) copolymer is preferably 0.5 ⁇ mol/g or more, more preferably 5 ⁇ mol/g or more, and still more preferably It is 10 ⁇ mol/g or more, particularly preferably 15 ⁇ mol/g or more, preferably 150 ⁇ mol/g or less, more preferably 100 ⁇ mol/g or less, still more preferably 70 ⁇ mol/g or less, and particularly preferably 50 ⁇ mol/g or less.
  • the (A) copolymer has a crosslinkable functional group. That is, the copolymer (A) contains a structural unit (a-1) having a crosslinkable functional group in its structure.
  • the structural unit (a-1) having the crosslinkable functional group may be of only one type, or may be of two or more types.
  • the crosslinkable functional group is a structural unit derived from a (meth)acrylic monomer (preferably a (meth)acrylate monomer and/or (meth)acrylic acid), and a structural unit derived from a vinyl monomer other than the (meth)acrylic monomer. You can have either.
  • the structural unit (a-1) having a crosslinkable functional group is a structure derived from a (meth)acrylic monomer (preferably (meth)acrylate monomer and/or (meth)acrylic acid) having a crosslinkable functional group. unit, or a structural unit derived from a vinyl monomer other than a (meth)acrylic monomer having a crosslinkable functional group.
  • the content of the structural unit (structural unit (a-1) having a crosslinkable functional group) derived from a vinyl monomer having a crosslinkable functional group in the copolymer (A) is 100% by mass of the entire copolymer. , preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 1% by mass or more, particularly preferably 3% by mass or more, and preferably 20% by mass or less, more preferably is 15% by mass or less, more preferably 10% by mass or less, and particularly preferably 8% by mass or less.
  • the vinyl monomer having a crosslinkable functional group includes vinyl monomers other than (meth)acrylic monomers having a crosslinkable functional group and (meth)acrylic monomers having a crosslinkable functional group.
  • Examples of the (meth)acrylic monomer include (b1) a (meth)acrylic monomer having no crosslinkable functional group and (b2) a (meth)acrylic monomer having a crosslinkable functional group. These monomers may be used alone or in combination of two or more.
  • the (b1) (meth)acrylic monomer having no crosslinkable functional group is preferably (b1-1) a (meth)acrylate monomer having no crosslinkable functional group.
  • Examples of the (b2) (meth)acrylic monomer having a crosslinkable functional group include (b2-1) a (meth)acrylate monomer having a crosslinkable functional group.
  • the (b1) (meth)acrylic monomer having no crosslinkable functional group includes (meth)acrylates having a linear alkyl group, (meth)acrylates having a branched alkyl group, and (meth)acrylates having an alkoxy group. ) acrylates, (meth)acrylates having an alicyclic hydrocarbon group, (meth)acrylates having an aromatic group, (meth)acrylates having a tertiary amino group, and (meth)acrylamides.
  • (meth)acrylates having a linear alkyl group (meth)acrylates having a branched alkyl group, (meth)acrylates having an alicyclic hydrocarbon group, and (meth)acrylates having an aromatic group and (meth)acrylamides are preferred.
  • the (meth)acrylate having a straight-chain alkyl group is preferably a (meth)acrylate having a straight-chain alkyl group having 1 to 20 carbon atoms in the straight-chain alkyl group.
  • (Meth)acrylates having 5 to 15 linear alkyl groups are more preferred.
  • Examples of (meth)acrylates having a linear alkyl group include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, and n-hexyl (meth)acrylate.
  • n-octyl (meth)acrylate n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-lauryl (meth)acrylate, n-stearyl (meth)acrylate and other linear alkyl (meth)acrylates esters.
  • the (meth)acrylate having a branched-chain alkyl group is preferably a (meth)acrylate having a branched-chain alkyl group having 3 to 20 carbon atoms in the branched-chain alkyl group. (Meth)acrylates with 3 to 10 branched alkyl groups are preferred.
  • Examples of (meth)acrylates having a branched alkyl group include isopropyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isooctyl (meth)acrylate, 2 - (meth)acrylic acid branched chain alkyl esters such as ethylhexyl (meth)acrylate, isononyl (meth)acrylate and isodecyl (meth)acrylate.
  • (meth)acrylates having an alkoxy group examples include (meth)acrylic acid alkoxyalkyl esters such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate.
  • Examples of (meth)acrylates having an alicyclic hydrocarbon group include (meth)acrylates having a cyclic alkyl group and (meth)acrylates having a polycyclic structure.
  • the (meth)acrylate having a cyclic alkyl group is preferably a (meth)acrylate having a cyclic alkyl group having 6 to 12 carbon atoms.
  • the cyclic alkyl group includes a cyclic alkyl group having a monocyclic structure (for example, a cycloalkyl group), and may have a chain portion.
  • (meth)acrylates having a cyclic alkyl group having a monocyclic structure include (meth)acrylic acid cyclic alkyl esters such as cyclohexyl (meth)acrylate, methylcyclohexyl (meth)acrylate, and cyclododecyl (meth)acrylate. be able to.
  • the (meth)acrylate having a polycyclic structure is preferably a (meth)acrylate having a polycyclic structure with 6 to 12 carbon atoms.
  • the polycyclic structure includes cyclic alkyl groups having a bridged ring structure (eg, adamantyl group, norbornyl group, isobornyl group), and may have a chain portion.
  • (meth)acrylates having a polycyclic structure include bornyl (meth)acrylate, isobornyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-adamantyl (meth)acrylate, 2-methyl-2- adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate, norbornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyloxyethyl (meth) Acrylate, dicyclopentenyloxyethyl (meth)acrylate and the like can be mentioned.
  • the (meth)acrylate having an aromatic group is preferably a (meth)acrylate having an aromatic group having 6 to 12 carbon atoms.
  • the aromatic group include an aryl group, and may have a chain portion such as an alkylaryl group, an aralkyl group, an aryloxyalkyl group, and the like.
  • the (meth)acrylate having an aromatic group include a compound in which an aryl group is directly bonded to a (meth)acryloyloxy group, a compound in which an aralkyl group is directly bonded to a (meth)acryloyloxy group, and a (meth)acryloyloxy group.
  • a compound having an alkylaryl group directly bonded thereto may be mentioned.
  • the aryl group preferably has 6 to 12 carbon atoms.
  • the aralkyl group preferably has 6 to 12 carbon atoms.
  • the alkylaryl group preferably has 6 to 12 carbon atoms.
  • (Meth)acrylates having an aromatic group include benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl (meth)acrylate and the like.
  • Examples of (meth)acrylates having a tertiary amino group include 2-(dimethylamino)ethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.
  • Examples of the (meth)acrylamides include N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N,N-diisopropyl(meth)acrylamide, (meth)acrylamide, N-methyl(meth) Acrylamide, N-ethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-tert-butyl (meth)acrylamide, N-octyl (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl ( meth)acrylamide, N-propoxymethyl(meth)acrylamide, N-butoxymethyl(meth)acrylamide, diacetoneacrylamide, 4-(meth)acryloylmorpholine and the like.
  • the (meth)acrylamides are (meth)acryl monomers, but are not included in (meth)acrylate monomers.
  • the (b2) (meth)acrylic monomer having a crosslinkable functional group includes a (meth)acrylic monomer having a hydroxy group (preferably a (meth)acrylate monomer), a (meth)acrylic monomer having a carboxy group (preferably ( meth)acrylic acid), (meth)acrylic monomers (preferably (meth)acrylate monomers) having an epoxy group, and the like.
  • a (meth)acrylic monomer having a hydroxy group and/or a (meth)acrylic monomer having a carboxy group are preferred.
  • Examples of the (meth)acrylic monomer having a hydroxy group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6 - hydroxyalkyl (meth)acrylates such as hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate; (4-hydroxymethylcyclohexyl) hydroxyalkylcycloalkane (meth)acrylates such as methyl (meth)acrylate; and caprolactone adducts of hydroxyalkyl (meth)acrylates.
  • hydroxyalkyl (meth)acrylates are preferred, and (meth)acrylates having a hydroxyalkyl group having 1 to 5 carbon atoms are more preferred.
  • Examples of the (meth)acrylic monomer having a carboxy group include carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl maleate, 2 - Monomers obtained by reacting (meth)acrylates having a hydroxy group such as (meth)acryloyloxyethyl phthalate with acid anhydrides such as maleic anhydride, succinic anhydride, and phthalic anhydride (e.g., 2-acryloyloxy hydrogen succinate) Ethyl, 2-methacryloyloxyethyl hydrogen succinate, 2-(acryloyloxy)ethyl hydrogen hexahydrophthalate, 2-(methacryloyloxyethyl) hydrogen hexahydrophthalate, 1-(2-acryloyloxyethyl) phthalate, phthalate acid 1-(2-methacryl
  • Examples of the (meth)acrylic acid ester having an epoxy group include glycidyl (meth)acrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate.
  • vinyl monomers other than the (meth)acrylic monomer examples include (b3) a vinyl monomer other than a (meth)acrylic monomer having no crosslinkable functional group, and (b4) a (meth)acrylic monomer having a crosslinkable functional group. Vinyl monomers are mentioned. These monomers may be used alone or in combination of two or more.
  • Vinyl monomers other than the (b3) (meth)acrylic monomer having no crosslinkable functional group include aromatic vinyl monomers, vinyl monomers containing heterocycles, vinyl carboxylates, and vinyl monomers containing a tertiary amino group. , vinylamides, ⁇ -olefins, dienes, halogenated vinyl monomers, and the like.
  • Examples of the aromatic vinyl monomers include styrene, ⁇ -methylstyrene, 4-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methoxystyrene and 1-vinylnaphthalene.
  • Examples of the vinyl monomer containing the heterocycle include 2-vinylthiophene, N-methyl-2-vinylpyrrole, 2-vinylpyridine, 4-vinylpyridine and the like.
  • Examples of the vinyl carboxylate include vinyl acetate, vinyl pivalate, and vinyl benzoate.
  • Examples of vinyl monomers containing a tertiary amino group include N,N-dimethylallylamine.
  • Examples of the vinylamides include N-vinylformamide, N-vinylacetamide, 1-vinyl-2-pyrrolidone, N-vinyl- ⁇ -caprolactam and the like.
  • Examples of the ⁇ -olefin include 1-hexene, 1-octene, 1-decene and the like.
  • Examples of the dienes include butadiene, isoprene, 4-methyl-1,4-hexadiene, and 7-methyl-1,6-octadiene.
  • halogenated vinyl monomer examples include vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, hexafluoropropylene, tetrafluoropropylene, vinylidene chloride, vinyl chloride, 1-chloro-1-fluoro Examples include ethylene, 1,2-dichloro-1,2-difluoroethylene, and the like.
  • Examples of the (b4) vinyl monomer other than the (meth)acrylic monomer having a crosslinkable functional group include a vinyl monomer having a hydroxy group, a vinyl monomer having a carboxy group, and a vinyl monomer containing an epoxy group.
  • Examples of vinyl monomers having a hydroxy group include p-hydroxystyrene and allyl alcohol.
  • vinyl monomers having a carboxyl group include crotonic acid, maleic acid, itaconic acid, citraconic acid, and cinnamic acid.
  • Examples of vinyl monomers containing epoxy groups include 2-allyloxirane, glycidyl vinyl ether, 3,4-epoxycyclohexyl vinyl ether, and the like.
  • the (A) copolymer may be a random copolymer, a block copolymer, or a graft copolymer, preferably a random copolymer.
  • the weight average molecular weight (Mw) of the (A) copolymer is preferably 200,000 or more, more preferably 300,000 or more, still more preferably 400,000 or more, and preferably 3 million or less, more preferably 2 million or less. , more preferably 1,500,000 or less, and particularly preferably 1,100,000 or less.
  • Mw of the (A) copolymer is 200,000 or more, the cohesive force is increased and the heat resistance of the adhesive material is improved. A method for measuring the weight average molecular weight (Mw) will be described later.
  • the molecular weight distribution (Mw/Mn) of the (A) copolymer is preferably 3.0 or less, more preferably 2.7 or less, and still more preferably 2.5 or less.
  • the molecular weight distribution (Mw/Mn) is a value calculated by (weight average molecular weight (Mw))/(number average molecular weight (Mn)), and methods for measuring Mw and Mn will be described later. .
  • the glass transition temperature (Tg) of the copolymer (A) is preferably ⁇ 70° C. or higher, more preferably ⁇ 60° C. or higher, and preferably 0° C. or lower, more preferably ⁇ 10° C. or lower, further preferably -20°C or lower, particularly preferably -35°C or lower. If the glass transition temperature is -70°C or higher, the adhesive will have sufficient cohesive strength and the durability of the adhesive will be improved. etc. are suppressed, and the durability is improved.
  • the glass transition temperature (Tg) of the (A) copolymer is a value calculated by the following FOX formula (formula (1)).
  • Tg represents the glass transition temperature (°C) of the copolymer.
  • Tgi indicates the glass transition temperature (°C) when the vinyl monomer i forms a homopolymer.
  • i is a natural number from 1 to n.
  • Table 2 shows the glass transition temperatures of representative homopolymers.
  • the copolymer (A) is obtained by living radical polymerization of a monomer composition containing two or more vinyl monomers (obtained by polymerization using a living radical polymerization method). be.
  • the living radical polymerization method maintains the simplicity and versatility of the conventional radical polymerization method. It is easy to precisely control and manufacture a polymer with a uniform composition. Therefore, in the copolymer produced by the living radical polymerization method, the crosslinkable functional groups are uniformly distributed in each molecular chain. Therefore, if a copolymer produced by a living radical polymerization method is used, the density of cross-linking points in the formed adhesive layer becomes uniform as a whole. When the crosslink point density is uniform throughout, the recovery rate of the adhesive layer can be made better.
  • a random copolymer can be obtained by using a mixture of the monomers (vinyl monomers) constituting the (A) copolymer.
  • a block copolymer can also be obtained by sequentially reacting vinyl monomers constituting the copolymer.
  • Living radical polymerization methods include methods using compounds that can generate nitroxide radicals (nitrooxide method; NMP method); A method of living polymerization from the polymerization initiation compound (ATRP method); a method of using a dithiocarboxylic acid ester or a xanthate compound (RAFT method); a method of using an organic tellurium compound (TERP method); A method using an organic iodine compound (ITP method); a method using an iodine compound as a polymerization initiator compound and an organic compound such as a phosphorus compound, a nitrogen compound, an oxygen compound, or a hydrocarbon as a catalyst (reversible transfer catalyst polymerization; RTCP method, reversible catalyst-mediated polymerization; RCMP method).
  • TERP method it is preferable to use the TERP method from the viewpoint of the diversity of usable monomers, molecular weight control in the high molecular region, uniform composition, or coloring.
  • the TERP method is a method of polymerizing a radically polymerizable compound (vinyl monomer) using an organic tellurium compound as a chain transfer agent. 2004/072126 and methods described in WO 2004/096870.
  • Specific polymerization methods for the TERP method include the following (a) to (d).
  • R 1 is an alkyl group having 1 to 8 carbon atoms, an aryl group, or an aromatic heterocyclic group.
  • R 2 and R 3 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
  • R 4 is an alkyl group having 1 to 8 carbon atoms, an aryl group, a substituted aryl group, an aromatic heterocyclic group, an alkoxy group, an acyl group, an amido group, an oxycarbonyl group, a cyano group, an allyl group or a propargyl group.
  • R 1 is an alkyl group having 1 to 8 carbon atoms, an aryl group or an aromatic heterocyclic group.
  • Specific examples of the organic ditelluride compound represented by formula (2) include dimethyl ditelluride, dibutyl ditelluride, and the like.
  • the azo polymerization initiator can be used without particular limitation as long as it is an azo polymerization initiator used in normal radical polymerization.
  • ADVN ,2′-azobis(2,4-dimethylvaleronitrile)
  • ACBN 1,1′-azobis(1-cyclohexanecarbonitrile)
  • V-70 2,2′-azobis(4-methoxy-2,4- dimethylvaleronitrile)
  • the polymerization step is carried out in a vessel substituted with an inert gas, with a vinyl monomer and an organic tellurium compound of formula (1) for the purpose of promoting the reaction, controlling the molecular weight and molecular weight distribution depending on the type of the vinyl monomer, and further adding an azo A polymerization initiator and/or an organic ditelluride compound of formula (2) are mixed.
  • the inert gas include nitrogen, argon, and helium. Argon and nitrogen are preferred.
  • the amount of the vinyl monomer used in (a), (b), (c) and (d) may be appropriately adjusted according to the physical properties of the desired copolymer.
  • the polymerization reaction can be carried out without a solvent, it may be carried out by using an aprotic or protic solvent generally used in radical polymerization and stirring the mixture.
  • Aprotic solvents that can be used are, for example, acetonitrile, methyl ethyl ketone, anisole, benzene, toluene, propylene glycol monomethyl ether acetate, ethyl acetate, tetrahydrofuran (THF), N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methyl-2-pyrrolidone (NMP), acetone, dioxane, chloroform, carbon tetrachloride and the like.
  • protic solvents examples include water, methanol, ethanol, isopropanol, n-butanol, ethyl cellosolve, butyl cellosolve, 1-methoxy-2-propanol, hexafluoroisopropanol, diacetone alcohol and the like.
  • a solvent may be used individually and may use 2 or more types together.
  • the amount of the solvent to be used may be appropriately adjusted, and is preferably 0.01 ml to 50 ml per 1 g of the vinyl monomer.
  • the reaction temperature and reaction time may be appropriately adjusted depending on the molecular weight or molecular weight distribution of the resulting copolymer, but the mixture is usually stirred at 0°C to 150°C for 1 minute to 100 hours.
  • the pressure is usually normal pressure, but may be pressurized or reduced.
  • the desired copolymer can be separated from the resulting reaction mixture by removing the used solvent, residual vinyl monomers, and the like by ordinary separation and purification means.
  • the growing terminal of the copolymer obtained by the polymerization reaction is in the form of —TeR 1 (wherein R 1 is the same as above) derived from the tellurium compound, and is deactivated by an operation in air after the completion of the polymerization reaction.
  • TeR 1 (wherein R 1 is the same as above) derived from the tellurium compound
  • tellurium atoms may remain. Copolymers with tellurium atoms remaining at the terminals are colored and have poor thermal stability, so the tellurium atoms may be removed.
  • Examples of the method for removing tellurium atoms include a radical reduction method; a method of adsorption with activated carbon or the like; a method of adsorbing a metal with an ion exchange resin or the like; these methods can also be used in combination.
  • the other end of the copolymer obtained by the polymerization reaction (the end opposite to the growing end) is -CR 2 R 3 R 4 derived from a tellurium compound (wherein R 2 , R 3 and R 4 are represented by the formula is the same as R 2 , R 3 and R 4 in (1)).
  • the adhesive composition contains (B) a cross-linking agent.
  • the (B) cross-linking agent is a compound having two or more cross-linkable points in one molecule capable of cross-linking with the functional group (preferably the cross-linkable functional group) of the (A) copolymer.
  • the crosslinkable point is a reactive group capable of reacting with the functional group of the copolymer (A).
  • the number of crosslinkable points is the number of alkoxy groups, acylate groups, isocyanate groups, epoxy groups, or aziridine groups.
  • cross-linking agent examples include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, aziridine-based cross-linking agents, metal chelate-based cross-linking agents, melamine resin-based cross-linking agents, and urea resin-based cross-linking agents.
  • the said crosslinking agent may be used individually by 1 type, and may use 2 or more types together.
  • isocyanate-based cross-linking agents, epoxy-based cross-linking agents, and aziridine-based cross-linking agents are preferable.
  • agent is more preferred, and from the viewpoint of heat resistance, an epoxy-based cross-linking agent is particularly preferred.
  • the isocyanate-based cross-linking agent is a compound having two or more isocyanate groups (including an isocyanate regenerative functional group in which the isocyanate group is temporarily protected by a blocking agent or quantization) as a reactive group in one molecule.
  • the isocyanate-based cross-linking agents may be used alone or in combination of two or more.
  • Isocyanate cross-linking agents include aromatic polyisocyanates, alicyclic polyisocyanates, aliphatic polyisocyanates, adducts of these with various polyols, isocyanurate bonds, biuret bonds, allophanate bonds, etc. polyisocyanate and the like.
  • lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, 1,3-bis(isocyanatomethyl ) Alicyclic polyisocyanates such as cyclohexane; Aromatic polyisocyanates such as isocyanate, tetramethylxylylene diisocyanate, 1,5-naphthalene diisocyanate, triphenylmethane triisocyanate and polymethylene polyphenyl isocyanate; trimethylolpropane/tolylene diisocyanate trimer adduct, trimethylolpropane Isocyanate adducts such as / hexamethylene diisocyanate trimer adduct, isocyanurate of hexamethylene diisocyanate;
  • an aliphatic polyisocyanate for example, an isocyanurate of hexamethylene diisocyanate
  • an isocyanurate of a aliphatic diisocyanate for example, an isocyanurate of hexamethylene diisocyanate
  • epoxy cross-linking agent refers to a compound having two or more epoxy groups as reactive groups in one molecule.
  • the epoxy-based cross-linking agents may be used alone or in combination of two or more.
  • epoxy-based cross-linking agents examples include bisphenol A type epoxy resin, epichlorohydrin type epoxy resin, ethylene glycidyl ether, N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, and diamine glycidyl.
  • the content of crosslinkable points in the crosslinker (B) is preferably 0.5 mmol/g or more, more preferably 1.0 mmol/g or more, still more preferably 3.0 mmol/g or more, and particularly preferably 6 0 mmol/g or more, preferably 20.0 mmol/g or less, more preferably 15.0 mmol/g or less, still more preferably 12.0 mmol/g or less. (B) If the content of the crosslinkable points of the crosslinker is within this range, the cohesive force of the formed adhesive material will be favorable, and even if it is bent, the occurrence of deformation at the bent portion can be further suppressed.
  • the total amount of crosslinkable points of the (B) crosslinking agent with respect to the unit mass of the (A) copolymer in the adhesive composition is preferably 1 ⁇ mol/g or more, more preferably 2 ⁇ mol/g or more, and still more preferably 3 ⁇ mol/g. /g or more, preferably 100 ⁇ mol/g or less, more preferably 50 ⁇ mol/g or less, still more preferably 10 ⁇ mol/g or less.
  • the molar ratio of the crosslinkable functional groups possessed by the copolymer (A) to the total amount of crosslinkable points possessed by the (B) crosslinking agent is preferably 4 or more, more preferably 8 or more, still more preferably 40 or more, preferably 500 or less, more preferably 250 or less, still more preferably 120 or less.
  • additives In addition to the (A) copolymer and (B) cross-linking agent, other additives may be added to the adhesive composition.
  • Other additives include cross-linking accelerators, cross-linking retarders, tackifying resins (tackifiers), silane coupling agents, polymerizable compounds, photopolymerization initiators, plasticizers, softeners, release aids, dyes, and pigments.
  • dyes include dyes, fluorescent brighteners, antistatic agents, wetting agents, surfactants, thickeners, antifungal agents, preservatives, oxygen absorbers, ultraviolet absorbers, antioxidants, near-infrared absorbers, water-soluble quenchers agents, fragrances, metal deactivators, nucleating agents, alkylating agents, flame retardants, lubricants, processing aids, and the like.
  • Cross-linking retarder A cross-linking retarder may be added to the adhesive composition as necessary.
  • the cross-linking retarder is a compound capable of suppressing an excessive increase in viscosity of the pressure-sensitive adhesive composition by blocking the functional group of the cross-linking agent in the pressure-sensitive adhesive composition containing the cross-linking agent.
  • cross-linking retarder is not particularly limited, but for example, ⁇ -diketones such as acetylacetone, hexane-2,4-dione, heptane-2,4-dione, octane-2,4-dione; ⁇ -ketoesters such as methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, octyl acetoacetate, oleyl acetoacetate, lauryl acetoacetate and stearyl acetoacetate; benzoylacetone and the like can be used.
  • the cross-linking retarder one capable of acting as a chelating agent is preferable, and ⁇ -diketones and ⁇ -ketoesters are preferable, and acetylacetone is particularly preferable.
  • the content of the cross-linking retarder that can be blended in the adhesive composition is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, relative to 100 parts by mass of the copolymer (A). It is preferably 0.08 parts by mass or more, preferably 4.0 parts by mass or less, more preferably 3.0 parts by mass or less, and even more preferably 1.0 parts by mass or less.
  • silane coupling agent A silane coupling agent may be added to the adhesive composition as necessary.
  • the silane coupling agent include, but are not limited to, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, Epoxy group-containing silane coupling agents such as 2-(3,4 epoxycyclohexyl)ethyltrimethoxysilane; 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3- Amino group-containing silane coupling agents such as triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl- ⁇ -aminopropyltrimethoxysilane; 3-acryloxypropyltrimethoxysilane, 3- Examples thereof include (meth)acryl
  • the content of the silane coupling agent that can be blended in the adhesive composition is preferably 1 part by mass or less, more preferably 0.01 part by mass to 1 part by mass with respect to 100 parts by mass of the copolymer (A). More preferably, it ranges from 0.02 parts by mass to 0.6 parts by mass.
  • tackifying resin A tackifying resin other than the copolymer may be blended in the adhesive composition, if necessary.
  • the tackifier resin is not particularly limited, and examples thereof include rosin-based tackifier resins, terpene-based tackifier resins, phenol-based tackifier resins, and hydrocarbon-based tackifier resins.
  • rosin-based tackifying resins examples include unmodified rosins (fresh rosins) such as gum rosin, wood rosin, tall oil rosin, and modified rosins obtained by modifying these unmodified rosins by polymerization, disproportionation, hydrogenation, etc. rosin, stabilized rosin, disproportionated rosin, completely hydrogenated rosin, partially hydrogenated rosin, and other chemically modified rosins), as well as various rosin derivatives.
  • fresh rosins fresh rosins
  • modified rosins obtained by modifying these unmodified rosins by polymerization, disproportionation, hydrogenation, etc.
  • rosin stabilized rosin, disproportionated rosin, completely hydrogenated rosin, partially hydrogenated rosin, and other chemically modified rosins
  • rosin derivative examples include rosin phenolic resins obtained by adding phenol to rosins (unmodified rosin, modified rosin) with an acid catalyst and thermally polymerizing them; Ester compounds (unmodified rosin esters) and denatured rosin ester compounds obtained by esterifying denatured rosin with alcohols (polymerized rosin esters, stabilized rosin esters, disproportionated rosin esters, completely hydrogenated rosin esters, partially hydrogenated rosin rosin ester-based resins such as esters); unsaturated fatty acid-modified rosin-based resins obtained by modifying unmodified rosin or modified rosin with unsaturated fatty acids; unsaturated fatty acid-modified rosin ester-based resins obtained by modifying rosin ester-based resins with unsaturated fatty acids ; unmodified rosin, modified rosin, rosin alcohol resin obtained by reducing the carboxyl group in unsaturated
  • Terpene-based tackifying resins include, for example, ⁇ -pinene polymer, ⁇ -pinene polymer, terpene-based resins such as dipentene polymer, and modification of these terpene-based resins (phenol modification, aromatic modification, hydrogenation modification, hydrocarbon-modified) modified terpene-based resins (for example, terpene-phenolic resins, styrene-modified terpene-based resins, aromatic modified terpene-based resins, hydrogenated terpene-based resins).
  • phenol modification, aromatic modification, hydrogenation modification, hydrocarbon-modified terpene-based resins for example, terpene-phenolic resins, styrene-modified terpene-based resins, aromatic modified terpene-based resins, hydrogenated terpene-based resins.
  • phenol-based tackifying resins include condensation products of various phenols (e.g., phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcinol) and formaldehyde (e.g., alkylphenol-based resins, xylene-formaldehyde-based resins), resoles obtained by addition reaction of the above phenols and formaldehyde with an alkali catalyst, and novolaks obtained by condensation reaction of the above phenols and formaldehyde with an acid catalyst.
  • phenols e.g., phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcinol
  • formaldehyde e.g., alkylphenol-based resins, xylene-formaldehyde-based resins
  • resoles obtained by addition reaction of the above phenols and formaldehyde with an alkali
  • hydrocarbon-based tackifying resins include, for example, aliphatic hydrocarbon resins [olefins and dienes having 4 to 5 carbon atoms (olefins such as butene-1, isobutylene, pentene-1; butadiene, Dienes such as 1,3-pentadiene and isoprene), etc.], aliphatic cyclic hydrocarbon resins [so-called “C4 petroleum fraction” and “C5 petroleum fraction” are cyclized dimers Alicyclic hydrocarbon resins polymerized after solidification, polymers of cyclic diene compounds (cyclopentadiene, dicyclopentadiene, ethylidenenorbornene, dipentene, etc.) or hydrogenated products thereof, aromatic hydrocarbon resins such as the following Alicyclic hydrocarbon resins obtained by hydrogenating aromatic rings of aliphatic/aromatic petroleum resins], aromatic hydrocarbon resins [vinyl group-containing
  • the content of the tackifying resin that can be blended in the adhesive composition is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and still more preferably 20 parts by mass with respect to 100 parts by mass of the (A) copolymer. It is at least 60 parts by mass, preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less.
  • the adhesive composition may contain a polymerizable compound. Flexibility can be imparted to the adhesive by blending the polymerizable compound and polymerizing the polymerizable compound in the adhesive.
  • Examples of the polymerizable compound include compounds having two or more polymerizable groups in one molecule.
  • Examples of polymerizable groups include ethylenically unsaturated groups.
  • the said polymerizable compound can be used individually or in combination of 2 or more types.
  • Examples of the polymerizable compound include compounds having two or more (meth)acryloyl groups, and polyfunctional monomers and polyfunctional oligomers are preferred.
  • the number of ethylenically unsaturated groups in one molecule of the polymerizable compound is preferably 2 or more, preferably 4 or less, and more preferably 3 or less.
  • Examples of the compound having two or more (meth)acryloyl groups include hexanediol di(meth)acrylate, butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, and (poly)propylene glycol.
  • the content of the polymerizable compound is preferably 0.1 parts by mass or more, more preferably 2.5 parts by mass, relative to 100 parts by mass of the copolymer (A). It is at least 100 parts by mass, preferably 50 parts by mass or less.
  • photopolymerization initiator When the polymerizable compound is cured with an active energy ray, it is preferable to incorporate a photopolymerization initiator into the adhesive composition. By blending a photopolymerization initiator, the reaction during active energy ray irradiation can be stabilized.
  • the photopolymerization initiator is not particularly limited as long as it generates radicals by the action of light. is mentioned. These photopolymerization initiators can be used alone or in combination of two or more. Among these photopolymerization initiators, photopolymerization initiators of hydrogen abstraction type benzophenones and intramolecular cleavage type acetophenones are preferable from the viewpoint of efficient intermolecular or intramolecular crosslinking.
  • the content of the photopolymerization initiator is preferably 0.01 parts by mass or more, more preferably 0.1, with respect to 100 parts by mass of the copolymer (A). It is at least 0.5 parts by mass, more preferably at least 0.5 parts by mass, preferably at most 10 parts by mass, more preferably at most 5 parts by mass, still more preferably at most 2 parts by mass.
  • the content of the photopolymerization initiator is within the above range, the curing speed is improved, and insufficient curing can be suppressed.
  • the adhesive composition may contain an auxiliary agent for the photopolymerization initiator.
  • auxiliary agent include triethanolamine, triisopropanolamine, 4,4'-dimethylaminobenzophenone (Michler's ketone), 4,4'-diethylaminobenzophenone, 2-dimethylaminoethylbenzoate, and ethyl 4-dimethylaminobenzoate.
  • plasticizer A plasticizer may be added to the adhesive composition, if necessary.
  • the plasticizer include, but are not limited to, oils such as paraffin oil and process oil; liquid rubbers such as liquid polyisoprene, liquid polybutadiene, and liquid ethylene-propylene rubber; tetrahydrophthalic acid, azelaic acid, benzoic acid, and phthalate.
  • Acids trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, citric acid and their derivatives; dioctyl phthalate (DOP), dibutyl phthalate (DBP), dioctyl adipate, adipine diisononyl acid (DINA), isodecyl succinate, and the like.
  • the said plasticizer may be used individually by 1 type, and may use 2 or more types together. Among these, liquid rubber is preferred.
  • the weight average molecular weight (Mw) of the liquid rubber is preferably 5,000 or more, more preferably 10,000 or more, and preferably 60,000 or less, more preferably 50,000 or less.
  • Mw weight average molecular weight
  • the content of the plasticizer is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 10 parts by mass with respect to 100 parts by mass of the (A) copolymer. It is at least 50 parts by mass, preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less.
  • the adhesive composition can be produced by mixing the (A) copolymer, (B) a cross-linking agent, and optionally a (meth)acrylic compound and other additives.
  • the adhesive composition may contain (A) a solvent derived from the production of the copolymer, or may be further diluted with an appropriate solvent so as to have a viscosity suitable for forming an adhesive layer. It may be a liquid solution.
  • the solvent examples include aliphatic hydrocarbons such as hexane and heptane; aromatic hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and ethylene chloride; acetone, methyl ethyl ketone, methyl isobutyl ketone, and 2-pentanone.
  • isophorone ketones such as cyclohexanone
  • esters such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate
  • cellosolve solvents such as ethyl cellosolve
  • ethanol isopropyl alcohol, n-butyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoisopropyl Alcohol solvents such as ether, propylene glycol monomethyl ether, and diethylene glycol monobutyl ether can be used. These solvents may be used singly or in combination of two or more.
  • the amount of the solvent used may be appropriately adjusted so that the adhesive composition has a viscosity suitable for coating, and is not particularly limited, but from the viewpoint of coatability, for example, 1% by mass to 90% by mass is preferable. , more preferably 10% by mass to 80% by mass, more preferably 20% by mass to 70% by mass.
  • the gel fraction of the adhesive material is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 99% by mass, and still more preferably 80% by mass to 99% by mass from the viewpoint of durability and adhesive strength. %, particularly preferably 90% to 99% by weight. If the gel fraction is too low, durability tends to be insufficient due to insufficient cohesion.
  • the gel fraction can be controlled by the blending amount of the cross-linking agent in the adhesive composition, the cross-linking treatment temperature, and the cross-linking treatment time.
  • the glass transition temperature (Tg) of the adhesive material is preferably ⁇ 70° C. or higher, more preferably ⁇ 60° C. or higher, still more preferably ⁇ 50° C. or higher, and preferably 0° C. or lower, more preferably ⁇ 10° C. or lower. , and more preferably ⁇ 20° C. or lower. If the glass transition temperature is -70°C or higher, the adhesive will have sufficient cohesive strength and the durability of the adhesive will be improved. etc. are suppressed, and the durability is improved. In addition, it can withstand repeated bending in low-temperature environments such as cold regions. A method for measuring the glass transition temperature (Tg) of the adhesive will be described later.
  • the shear storage modulus (G′ 25 ) of the adhesive at 25° C. is preferably 0.015 MPa or more, more preferably 0.02 MPa or more, still more preferably 0.025 MPa or more, and preferably 0.07 MPa or less. It is more preferably 0.05 MPa or less, still more preferably 0.04 MPa or less.
  • the shear storage modulus (G′ ⁇ 40 ) of the adhesive at ⁇ 40° C. is preferably 0.1 MPa or more, more preferably 0.2 MPa or more, still more preferably 0.4 MPa or more, and 1.8 MPa or less. It is preferably 1.5 MPa or less, more preferably 1.2 MPa or less.
  • the shear storage modulus (G′ 60 ) of the pressure-sensitive adhesive at 60° C. is preferably 0.01 MPa or more, more preferably 0.02 MPa or more, still more preferably 0.03 MPa or more, and preferably 0.06 MPa or less. It is more preferably 0.055 MPa or less, still more preferably 0.05 MPa or less.
  • the adhesive has appropriate flexibility even in high-temperature and low-temperature environments, and the shape Followability becomes better, and cohesion and adhesiveness of the adhesive material become better.
  • a method for measuring the shear storage modulus (G') of the adhesive will be described later.
  • the adhesive material has a ratio (G ' -40 /G' 25 ) of a shear storage modulus (G' 25 ) at 25°C and a shear storage modulus (G' -40 ) at -40° C of 5 or more. more preferably 10 or more, still more preferably 15 or more, and preferably 35 or less, more preferably 30 or less, still more preferably 25 or less. If the ratio (G′ ⁇ 40 /G′ 25 ) is within the above range, the film has flexibility in a low-temperature environment and is excellent in adhesive strength and restorability.
  • the pressure-sensitive adhesive material has a ratio (G'25/ G'60 ) of a shear storage modulus (G'60) at 60°C and a shear storage modulus ( G'25 ) at 25 ° C of 0.5 or more. is preferably 0.7 or more, still more preferably 1.0 or more, and preferably 2.0 or less, more preferably 1.8 or less, still more preferably 1.5 or less.
  • the ratio (G' 25 /G' 60 ) is within the above range, it has heat resistance in a high-temperature environment and is excellent in adhesive strength and restorability.
  • the adhesive material may contain a metal component.
  • a copolymer produced by a living radical polymerization method may contain residual metal components (more than 0 mass ppm) as impurities derived from a chain transfer agent.
  • a tellurium component derived from the organic tellurium compound represented by formula (1) remains.
  • the adhesive contains a metal component, the adhesive strength of the adhesive becomes better.
  • the content of the tellurium component in the adhesive is 35 ⁇ 10 -6 in terms of metal with respect to 1 part by mass of the (A) (meth)acrylic copolymer. It is preferably at least 55 ⁇ 10 ⁇ 6 parts by mass, still more preferably at least 65 ⁇ 10 ⁇ 6 parts by mass, and preferably at most 1000 ⁇ 10 ⁇ 6 parts by mass, more preferably 400 ⁇ 10 ⁇ 6 parts by mass or more. It is 6 parts by mass or less, more preferably 200 ⁇ 10 ⁇ 6 parts by mass or less. If the content of the tellurium component in the adhesive material is 35 ⁇ 10 ⁇ 6 parts by mass or more, the adhesive strength will be further improved, and if it is 1000 ⁇ 10 ⁇ 6 parts by mass or less, the transparency of the adhesive material will be good.
  • the adhesive material is obtained by curing the adhesive composition. Specifically, the adhesive composition is heat-treated to remove the solvent, and (A) the (meth)acrylic copolymer and (B) the cross-linking agent are allowed to react. Moreover, the said adhesive material can adjust content of the (X) (meth)acrylic compound in the adhesive material obtained by adjusting the heat processing temperature and time of an adhesive composition.
  • the heat treatment may be performed at a constant temperature, or may be performed multiple times at different temperatures.
  • the heat treatment temperature is preferably 110° C. or higher, more preferably 125° C. or higher, still more preferably 140° C. or higher, and preferably 200° C. or lower, more preferably 180° C. or lower, further preferably 160° C. or lower.
  • the heat treatment time is preferably 1 to 8 minutes, more preferably 2 to 5 minutes. Examples of heat treatment means include hot air, near infrared rays, infrared rays, and high frequency.
  • the adhesive material of the present invention is preferably used for the adhesive layer (adhesive material) used in flexible displays that can be repeatedly bent and stretched.
  • the flexible display that can be used by repeatedly bending and stretching include a foldable display that can be folded and a rollable display that can be rolled into a cylindrical shape.
  • Flexible displays are expected to be used for mobile terminals such as smartphones and tablet terminals, and stationary displays that can be stored.
  • the adhesive material is suitable for a flexible display adhesive material for bonding one flexible member and another flexible member that constitute a flexible display.
  • the pressure-sensitive adhesive sheet of the present invention comprises a base sheet and a pressure-sensitive adhesive layer formed on at least one surface of the base sheet, wherein the pressure-sensitive adhesive layer is the pressure-sensitive adhesive.
  • the adhesive layer is formed on at least one side or at least a part of the base sheet.
  • the adhesive layer may be a single layer or may have a multilayer structure.
  • sheet is defined in JIS as a flat product that is thin and generally has a small thickness relative to its length and width.
  • a thin flat product with an extremely small thickness and an arbitrarily limited maximum thickness usually supplied in the form of a roll (Japanese Industrial Standard JIS K6900).
  • a thickness of 100 ⁇ m or more is called a sheet, and a thickness of less than 100 ⁇ m is sometimes called a film.
  • the boundary between a sheet and a film is not clear, and there is no need to distinguish between the two in the present invention. But "sheet” is included.
  • the base sheet can be appropriately selected and used according to the application of the pressure-sensitive adhesive sheet.
  • Polyimide resin such as polyethylene terephthalate (PET) resin and polyethylene naphthalate (PEN) resin; polycarbonate resin; poly(meth)acrylate resin; polystyrene resin; polyamide resin;
  • Polyolefin resins such as polyethylene resins, polycycloolefin resins, cycloolefin copolymer resins; polyphenylene sulfide resins; polysulfone resins; polyether sulfone resins; polyether ether ketone resins; (TAC) resin, cellulose resin such as diacetyl cellulose resin; polyvinyl chloride resin; polyvinylidene chloride resin; polyvinyl alcohol resin; polyvinyl acetate resin;
  • TAC polyether ether ketone resin
  • the polymeric material is selected from the group consisting of polyethylene terephthalate resin, polyimide resin, polycarbonate resin, poly(meth)acrylate resin, polycycloolefin resin, cycloolefin copolymer resin and triacetylcellulose resin. It is preferable to contain at least one selected material, and among these, PET is preferable in terms of excellent mechanical strength and dimensional stability. Moreover, polyimide is preferable in terms of excellent heat resistance. That is, the base sheet is preferably a PET sheet (especially a biaxially stretched PET sheet) or a polyimide sheet.
  • the thickness of the base sheet is not particularly limited and may be appropriately selected, but is generally preferably 5 ⁇ m or more, more preferably 10 ⁇ m or more, still more preferably 20 ⁇ m or more, and preferably 200 ⁇ m or less, more preferably 100 ⁇ m. 50 ⁇ m or less, more preferably 50 ⁇ m or less. If the thickness is less than 5 ⁇ m, the strength of the base sheet will be insufficient, and problems such as tearing of the sheet will occur when peeled off. Further, if the thickness of the base sheet is thicker than 200 ⁇ m, problems such as the sheet itself becoming expensive occur.
  • one side or both sides of the base sheet can be surface-treated by an oxidation method, a roughening method, or the like, if desired.
  • the oxidation method include corona discharge treatment, plasma treatment, chromic acid treatment (wet), flame treatment, hot air treatment, ozone/ultraviolet irradiation treatment, and the like.
  • the roughening method include a sandblasting method and a solvent treatment method.
  • the thickness of the adhesive material (adhesive layer) formed on the base sheet can be appropriately set according to, for example, the adhesive force required for the adhesive sheet.
  • the thickness of the adhesive layer is generally 1 ⁇ m to 100 ⁇ m, preferably 5 ⁇ m to 50 ⁇ m, more preferably 10 ⁇ m to 30 ⁇ m.
  • the method for forming the adhesive layer is not particularly limited, and for example, a method of applying an adhesive composition, heat-treating, and removing the solvent as in the following methods (1) and (2). mentioned.
  • (1) A method of applying an adhesive composition to one or both sides of a substrate sheet using various coating devices, heat-treating, and curing as necessary.
  • (2) Using various coating devices, the adhesive composition is applied to the release surface of the release sheet whose surface has been subjected to release treatment, heat-treated, and transferred to one or both sides of the base sheet. How to cure according to.
  • Examples of the coating apparatus include reverse roll coaters, gravure coaters, forward roll coaters, knife coaters, wire bar coaters, doctor blade coaters, slot die coaters, curtain coaters, and dip coaters.
  • the curing conditions include, for example, 30°C to 50°C for 3 to 7 days.
  • the pressure-sensitive adhesive sheet may have a release sheet (separator) on the surface of the pressure-sensitive adhesive layer until it is used.
  • a release layer is provided on the opposite side of the adhesive layer laminated surface of the base sheet without using a separate release sheet, and the surface of the release layer is wound in a roll so that the exposed surface side of the adhesive layer is in contact. , or may be stacked in a stack.
  • the release sheet is used as a protective material for the adhesive layer, and is peeled off when the adhesive sheet of the present invention is attached to an adherend.
  • the release sheet examples include paper such as glassine paper, coated paper, laminated paper, and various plastic sheets coated with a release agent such as silicone resin.
  • the plastic sheet used for the release sheet the ones listed as the base sheet can be appropriately used.
  • the thickness of the release sheet is not particularly limited, it is usually 10 ⁇ m to 150 ⁇ m.
  • the adhesive sheet include an adhesive layer used for bonding one flexible member and another flexible member constituting a flexible display, and a flexible sheet attached to at least one surface of the adhesive layer.
  • the configuration of the pressure-sensitive adhesive sheet includes an embodiment having an adhesive layer and a first flexible sheet member attached to one surface of the adhesive layer; An aspect having a first flexible sheet member and a second flexible sheet member adhered to the other surface of the adhesive layer may be mentioned.
  • FIG. 1 An example of the adhesive sheet of the present invention is shown in FIG.
  • the adhesive sheet 10 in FIG. 1 is composed of an adhesive layer 12, a first flexible sheet member 14 sandwiching the adhesive layer 12, and a second flexible sheet member 16. As shown in FIG. The adhesive layer 12 is in contact with the releasable surfaces of the first flexible sheet member 14 and the second flexible sheet member 16 .
  • the adhesive layer is formed from the adhesive material.
  • the thickness of the adhesive layer is preferably 5 ⁇ m or more, more preferably 10 ⁇ m or more, still more preferably 20 ⁇ m or more, and particularly preferably 40 ⁇ m or more, from the viewpoint of ensuring sufficient adhesion to the adherend.
  • the thickness of the adhesive layer is preferably 100 ⁇ m or less, more preferably 75 ⁇ m or less, and even more preferably 60 ⁇ m or less from the viewpoint of suppressing the protrusion of the adhesive layer.
  • the adhesive strength of the adhesive layer to the flexible sheet member (excluding the release sheet) at 23°C is preferably 10 N/25 mm or more, more preferably 13 N/25 mm or more, and still more preferably 15 N/25 mm or more. If it is 10 N/25 mm or more, it is possible to suppress lifting and peeling of the adhesive material. Although the upper limit of the adhesive strength is not particularly limited, it is usually 50 N/25 mm or less, preferably 40 N/25 mm or less.
  • the adhesive strength of the adhesive layer to the flexible sheet member (excluding the release sheet) at 60°C is preferably 7 N/25 mm or more, more preferably 10 N/25 mm or more, still more preferably 12 N/25 mm or more. If it is 7 N/25 mm or more, it is possible to suppress lifting and peeling of the adhesive even in a high-temperature environment.
  • the upper limit of the adhesive strength is not particularly limited, it is usually 50 N/25 mm or less, preferably 40 N/25 mm or less.
  • the flexible sheet members include flexible base sheets and release sheets.
  • the base sheet is a sheet member that supports the adhesive layer, and this sheet member may be a functional sheet member.
  • the functional sheet members include cover films, barrier films, polarizing films, retardation films, optical compensation films, brightness enhancement films, diffusion films, and antireflection films.
  • the release sheet protects the adhesive layer until the adhesive layer is adhered to the adherend, and is peeled off from the adhesive layer before the adhesive layer is adhered to the adherend.
  • the flexible sheet members include polymeric material sheets and glass sheets.
  • the thickness of the flexible sheet member is not particularly limited, it is preferably 2 ⁇ m to 500 ⁇ m, more preferably 2 ⁇ m to 200 ⁇ m from the viewpoint of excellent handleability.
  • Polyimide resin polyester resin such as polyethylene terephthalate resin and polyethylene naphthalate resin; polycarbonate resin; poly(meth)acrylate resin; polystyrene resin; polyamide resin; Polyolefin resins such as cycloolefin resins and cycloolefin copolymer resins; polyphenylene sulfide resins; polyvinyl chloride resins; polyvinylidene chloride resins; polyvinyl alcohol resins; The polymeric materials may be used alone or in combination of two or more.
  • the flexible sheet member may be composed of a single layer comprising a layer containing one or more of the polymeric materials, or a layer containing one or more of the polymeric materials and a layer containing the polymeric material. It may be composed of two or more layers, such as a layer containing one or more polymeric materials different from the layer.
  • the flexible sheet member is preferably a release sheet whose surface in contact with the adhesive layer is subjected to release treatment.
  • Release agents used in the release treatment include, for example, silicone-based, fluorine-based, alkyd-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents.
  • the adhesive sheet has a first flexible sheet member attached to one surface of the adhesive layer and a second flexible sheet member attached to the other surface of the adhesive layer.
  • the sheet member is a first release sheet
  • the second flexible sheet member is a second release sheet
  • the first release sheet and the second release sheet are attached such that the release surfaces of the first release sheet and the second release sheet are in contact with the adhesive layer. is preferred.
  • one of the release sheets should be a heavy release type release sheet with a large release force
  • the other release sheet should be a light release type release sheet with a small release force. is preferred.
  • the pressure-sensitive adhesive sheet can be produced, for example, by coating the above-described pressure-sensitive adhesive composition on a flexible sheet member and, if necessary, curing it by heat treatment to form the pressure-sensitive adhesive layer.
  • a reverse gravure coating method for example, a reverse gravure coating method, a direct gravure coating method, a die coating method, a bar coating method, a wire bar coating method, a roll coating method, a spin coating method, a dip coating method, a spray coating method, a knife
  • Various coating methods such as coating method and kiss coating method; inkjet method; various printing methods such as offset printing, screen printing and flexo printing can be employed.
  • the surface of the release sheet may be subjected to surface treatment such as corona treatment, plasma treatment, hot air treatment, ozone treatment, and ultraviolet treatment.
  • the heat treatment is not particularly limited as long as the solvent or the like used in the adhesive composition can be removed and the adhesive composition can be cured, but it is preferable to perform the heat treatment at a temperature of 110°C to 200°C for about 1 to 8 minutes.
  • the adhesive composition is applied to the first flexible sheet member, and the adhesive layer is formed on the first flexible sheet member. is formed, the second flexible sheet member may be adhered to this adhesive layer. Furthermore, the adhesive layer may be cured as necessary.
  • the curing conditions include, for example, 60° C. for about 3 to 7 days.
  • the pressure-sensitive adhesive material of the present invention can be suitably used for flexible laminated members.
  • the flexible laminate member includes a first flexible member, a second flexible member, and an adhesive layer for bonding the first flexible member and the second flexible member to each other, wherein the adhesive
  • the layer is characterized by being made of the adhesive material. Since the adhesive layer of the flexible laminated member is formed from the adhesive material, even when the flexible laminated member is repeatedly bent, appearance defects such as wavy appearance at the bent portion are suppressed.
  • the flexible laminated member 20 of FIG. 2 includes a first flexible member 22, a second flexible member 24, and an adhesive layer between the first flexible member 22 and the second flexible member 24 for bonding these flexible members together. 12.
  • the configuration of the flexible laminated member includes, for example, a configuration in which both the first flexible member and the second flexible member are constituent members of the flexible device;
  • a configuration that is a functional sheet member bonded to a flexible device may be mentioned.
  • the flexible device include a foldable display that can be folded and a rollable display that can be rolled into a cylinder.
  • the functional sheet members include cover films, barrier films, polarizing films, retardation films, optical compensation films, brightness enhancement films, diffusion films, antireflection films, transparent conductive films, metal mesh films, cushion films, and the like. be done.
  • the first flexible member and the second flexible member are members that can be repeatedly bent or bent for use.
  • Examples of the first flexible member and the second flexible member include flexible substrate materials, functional sheet members, and display elements (organic EL modules, electronic paper modules, etc.). At least one of the first flexible member and the second flexible member is preferably a display element.
  • the flexible laminate member can be used in flexible displays.
  • the method for producing the flexible laminated member is not particularly limited, and examples thereof include the following methods (1) to (4).
  • the release sheet attached to one surface of the adhesive sheet is peeled off, the exposed adhesive layer is attached to the first flexible member, and then the release sheet is attached to the other surface of the adhesive sheet. is peeled off, and the exposed adhesive layer and the second flexible member are adhered to obtain a flexible laminated member.
  • the adhesive layer After coating the adhesive composition on one surface of the first flexible member and curing it by drying and heat treatment as necessary to form an adhesive layer, the adhesive layer has the releasability of a release sheet. Affix the surface. Then, the adhesive layer exposed by peeling off the release sheet is attached to the second flexible member to obtain a flexible laminated member.
  • the order of using the first flexible member and the second flexible member may be changed.
  • the adhesive layer can be formed using various coating methods and various printing methods similar to those used in the production of the adhesive sheet, and the same applies to the drying and curing steps. Moreover, you may cure as needed.
  • the release sheet used for manufacturing the flexible laminated member may be the same as the release sheet used for the pressure-sensitive adhesive sheet.
  • the present invention will be described in more detail based on specific examples.
  • the present invention is by no means limited to the following examples, and can be modified as appropriate without changing the gist of the invention.
  • Mw weight average molecular weight
  • Mw/Mn molecular weight distribution
  • (meth)acrylic compound content of the adhesive the gel fraction, the glass transition temperature, the shear storage modulus, the adhesive strength, 400%
  • the recovery rate when distorted was evaluated according to the following method.
  • EHA 2-ethylhexyl acrylate
  • LA lauryl acrylate
  • AA acrylic acid
  • HBA 4-hydroxybutyl acrylate
  • BTEE ethyl 2-methyl-2-n-butyltheranyl-propionate
  • V-70 2,2′-azobis(4-methoxy -2,4-dimethylvaleronitrile)
  • AIBN azobisisobutyronitrile
  • AcOEt ethyl acetate
  • Polystyrene (molecular weight 2,890,000, 1,090,000, 775,000, 427,000, 190,000, 96,400, 37,900, 10,200, 2,630, 440) was used as a standard. Then, a calibration curve (calibration curve) was prepared, and the weight average molecular weight (Mw) and number average molecular weight (Mn) were measured. A molecular weight distribution (Mw/Mn) was calculated from this measured value.
  • Adhesive layer thickness (Adhesive layer thickness) Using a thickness measuring machine ("TH-104" manufactured by Tester Sangyo Co., Ltd.), the total thickness of the entire adhesive sheet is measured, and the thickness of the adhesive layer is obtained by subtracting the thickness of the release sheet from this total thickness. asked for
  • the adhesive layer (adhesive material) constituting the adhesive sheet was cut into a width of 20 mm and a length of 40 mm, both release sheets were peeled off from the adhesive layer, placed in a 20 mL vial, the sample mass was measured, and then sealed. Next, the vial was heated at 200° C. for 30 minutes using a headspace autosampler (HSS), and a sample gas was collected from the heated vial and injected into a gas chromatograph (GC) measuring device for analysis. . The monomer content was calculated using a calibration curve prepared in advance using reagents. The HSS and GC settings are as follows.
  • HSS TurboMatrix 40 manufactured by PerkinElmer Heating time: 30 minutes Pressure time: 3.00 minutes Injection time: 0.05 minutes
  • Adhesive layers (adhesive materials) constituting the adhesive sheet were laminated using a hand roller to prepare a laminate having a thickness of 0.5 mm. Using this laminate as a sample, the temperature change of the loss elastic modulus of the adhesive was measured using a viscoelasticity measuring device (manufactured by TA Instruments, ARES-G2), and the peak value was defined as the glass transition temperature (Tg).
  • Shear storage modulus Adhesive layers (adhesive materials) constituting the adhesive sheet were laminated using a hand roller to prepare a laminate having a thickness of 0.5 mm. Using this laminate as a sample, using a viscoelasticity measuring device (manufactured by TA Instruments, Discovery HR-2), shear mode, geometry: 8 mm diameter parallel plate, axial force: 2.2 N, frequency: 1 Hz, strain: 1 %, the shear storage modulus was measured at -40°C, 25°C and 60°C.
  • Adhesive layers (adhesive materials) constituting the adhesive sheet were laminated using a hand roller to prepare a laminate having a thickness of 0.5 mm.
  • a viscoelasticity measuring device manufactured by TA Instruments, Discovery HR-2
  • ⁇ angular frequency
  • Adhesive force One release sheet of the adhesive sheet was peeled off from the adhesive layer, and a corona-treated surface of a polyethylene terephthalate film (Toyobo Ester (registered trademark) film E5100: manufactured by Toyobo Co., Ltd., thickness 50 ⁇ m) was adhered to the adhesive layer surface, 25 mm wide, It was cut to a size of 150 mm in length.
  • the other release sheet is peeled off from the adhesive layer, and the adhesive layer surface is pressed against a polyimide (PI) film (Kapton (registered trademark) 200V: manufactured by Toray DuPont Co., Ltd., thickness 50 ⁇ m) by reciprocating a 2 kg roller twice. bottom.
  • PI polyimide
  • the other release sheet was peeled off from the adhesive layer, and a 2 kg roller was moved back and forth twice on a stainless steel plate (SUS304, surface finish BA, 60 mm ⁇ 30 mm ⁇ thickness 1.5 mm) so that the adhesion area was 25 mm ⁇ 25 mm. and crimped.
  • a weight of 1 kgf was vertically attached to the test piece and left to stand in an atmosphere of 80° C. for 24 hours. For those that did not fall within 24 hours, the length (mm) by which the bonding position between the stainless steel plate and the test piece deviated downward, that is, the amount of deviation was measured.
  • the obtained copolymer no. A had a weight average molecular weight (Mw) of 920,000, a molecular weight distribution (Mw/Mn) of 2.48, and a solid content of the solution of 25.0% by mass.
  • the resulting copolymer solution contained unreacted monomers (residual monomers).
  • the solid content of the copolymer solution is the total amount of components other than the solvent contained in the copolymer solution.
  • Copolymer no The copolymer solution containing A was heated at 130° C. for 1 hour to remove residual monomers. After that, nitric acid and hydrogen peroxide water were added to incinerate at 180 ° C. for 4 hours, and ultrapure water was added to prepare the test solution. Union No. The content of the tellurium component with respect to 1 part by mass of A was 91 ⁇ 10 ⁇ 6 parts by mass in terms of metal.
  • copolymer No. A copolymer solution containing B was obtained.
  • the Mw of B was 890,000, the Mw/Mn was 7.67, and the solid content of the solution was 39.5% by mass.
  • the resulting copolymer solution contained unreacted monomers (residual monomers).
  • Table 3 shows the raw material monomers, organic tellurium compounds, azo polymerization initiators, solvents, reaction conditions, etc. used.
  • Table 4 shows the composition, Mw, Mw/Mn, and glass transition temperature of each copolymer. The content of each functional group in the copolymer was calculated from the ratio of the monomers used in the polymerization reaction.
  • Adhesive composition No. 1 In the copolymer solution obtained in Synthesis Example 1, TETRAD (registered trademark)-C: manufactured by Mitsubishi Gas Chemical Co., Ltd., 1,3-bis(N,N-diglycidylaminoethyl)cyclohexane, epoxy group content: 9.76 mmol/g) 0.04 parts by mass was added and stirred. Adhesive composition No. got 1.
  • Adhesive composition No. 2 (Adhesive composition No. 2) Copolymer No. 1 obtained in Synthesis Example 2 was added to the copolymer solution.
  • the solid content of the copolymer solution containing B (97.3 parts by mass of the copolymer component of copolymer No. B, 2.7 parts by mass of the unreacted monomer component) was changed to 100 parts by mass.
  • Adhesive sheet No. 1 On the release surface of the first release sheet (PET film subjected to release treatment on the surface, Clean Sepa (registered trademark) HY-US20A: manufactured by Higashiyama Film Co., Ltd., thickness 75 ⁇ m), after drying using a baker applicator Adhesive composition No. 1 was added so that the film thickness was 50 ⁇ m. After applying No. 1, heat treatment was performed at 170° C. for 3 minutes using a constant temperature dryer.
  • the adhesive layer formed on the first release sheet is coated with a second release sheet (PET film whose surface is subjected to a release treatment, Clean Sepa (registered trademark) HY-S10: manufactured by Higashiyama Film Co., Ltd., thickness 50 ⁇ m).
  • a second release sheet PET film whose surface is subjected to a release treatment, Clean Sepa (registered trademark) HY-S10: manufactured by Higashiyama Film Co., Ltd., thickness 50 ⁇ m.
  • Adhesive sheet No. 2 to 4, 7, 8 Except for changing the heat treatment temperature and time as shown in Table 5, PSA sheet No. Adhesive sheet No. 1 was manufactured in the same manner as for No. 1. 2-4, 7, 8 were produced.
  • Adhesive sheet No. 5 On the release surface of the first release sheet (PET film subjected to release treatment on the surface, Clean Sepa (registered trademark) HY-US20A: manufactured by Higashiyama Film Co., Ltd., thickness 75 ⁇ m), the film after drying using a knife coater After the adhesive composition was applied to a thickness of 50 ⁇ m, it was heat treated at 70° C. for 1 minute using a hot air dryer, and then heat treated at 130° C. for 2 minutes using a hot air circulation dryer.
  • the adhesive layer formed on the first release sheet is coated with a second release sheet (PET film whose surface is subjected to a release treatment, Clean Sepa (registered trademark) HY-S10: manufactured by Higashiyama Film Co., Ltd., thickness 50 ⁇ m).
  • a second release sheet PET film whose surface is subjected to a release treatment, Clean Sepa (registered trademark) HY-S10: manufactured by Higashiyama Film Co., Ltd., thickness 50 ⁇ m.
  • Adhesive sheet No. 6 (Adhesive sheet No. 6) Except for changing the heat treatment temperature and time as shown in Table 5, PSA sheet No. Adhesive sheet No. 5 was produced in the same manner as for No. 5. 6 was produced.
  • Adhesive sheet No. 9 to 13 Adhesive composition no. 1 as Adhesive Composition No. 1; Adhesive sheet No. 2 except that the heat treatment temperature and time were changed as shown in Table 5. Adhesive sheet No. 1 was manufactured in the same manner as for No. 1. 9-13 were produced.
  • Adhesive sheet No. 1 to 6 the adhesive layer (adhesive material) is a cured product of an adhesive composition containing (A) a (meth)acrylic copolymer obtained by living radical polymerization and (B) a cross-linking agent. , the content of (X) (meth)acrylic compound in the cured product is 60 mass ppm to 5000 mass ppm.
  • These adhesive sheet Nos. 1 to 6 are excellent in the restoration rate of the adhesive layer (adhesive material) and also excellent in adhesive force.
  • Adhesive sheet No. In 7 and 8, the adhesive layer (adhesive material) consists of a cured product of an adhesive composition containing (A) a (meth)acrylic copolymer obtained by living radical polymerization and (B) a cross-linking agent. .
  • adhesive sheet No. In No. 7 the content of (X) (meth)acrylic compound in the cured product is less than 60 mass ppm. Therefore, the recovery rate and holding power of the adhesive layer (adhesive material) are inferior.
  • adhesive sheet No. In No. 8 the content of (X) (meth)acrylic compound in the cured product is more than 5000 ppm by mass. Therefore, adhesive strength is inferior.
  • the present invention includes the following aspects.
  • the (X) (meth)acrylic compound is a (meth)acrylate having a linear alkyl group, a (meth)acrylate having a branched alkyl group, a (meth)acrylate having an alicyclic hydrocarbon group, an aromatic 3.
  • the pressure-sensitive adhesive according to aspect 1 or 2 which is one or more compounds selected from the group consisting of (meth)acrylates and (meth)acrylamides having a group group.
  • Module 10 A substrate sheet and an adhesive layer formed on at least one surface of the substrate sheet, wherein the adhesive layer is the adhesive material according to any one of aspects 1 to 9. adhesive sheet.
  • a pressure-sensitive adhesive sheet having an adhesive layer used for bonding one flexible member and another flexible member, and a flexible sheet member adhered to at least one surface of the pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer is A pressure-sensitive adhesive sheet comprising the pressure-sensitive adhesive material according to any one of aspects 1 to 9.
  • the adhesive sheet has a first flexible sheet member attached to one surface of the adhesive layer and a second flexible sheet member attached to the other surface of the adhesive layer, and the first flexible sheet member is attached to the other surface of the adhesive layer.
  • the sheet member is a first release sheet
  • the second flexible sheet member is a second release sheet
  • the first release sheet and the second release sheet are attached such that the release surfaces of the first release sheet and the second release sheet are in contact with the adhesive layer.
  • Adhesive sheet 12 Adhesive layer 14: First flexible sheet member 16: Second flexible sheet member 20: Flexible laminate member 22: First flexible member 24: Second flexible member

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Materials For Medical Uses (AREA)
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014031440A (ja) * 2012-08-03 2014-02-20 Lintec Corp 保護フィルム及びその製造方法
WO2018062280A1 (ja) * 2016-09-30 2018-04-05 日東電工株式会社 偏光フィルム用粘着剤組成物、偏光フィルム用粘着剤層の製造方法、粘着剤層付偏光フィルム、及び、画像表示装置
WO2019021843A1 (ja) * 2017-07-25 2019-01-31 大塚化学株式会社 粘着剤組成物および粘着フィルム
JP2020076097A (ja) * 2018-11-06 2020-05-21 三菱ケミカル株式会社 無溶剤型粘着剤組成物、無溶剤型粘着剤および粘着シート
WO2021161990A1 (ja) * 2020-02-10 2021-08-19 積水化学工業株式会社 粘着テープ

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Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014031440A (ja) * 2012-08-03 2014-02-20 Lintec Corp 保護フィルム及びその製造方法
WO2018062280A1 (ja) * 2016-09-30 2018-04-05 日東電工株式会社 偏光フィルム用粘着剤組成物、偏光フィルム用粘着剤層の製造方法、粘着剤層付偏光フィルム、及び、画像表示装置
WO2019021843A1 (ja) * 2017-07-25 2019-01-31 大塚化学株式会社 粘着剤組成物および粘着フィルム
JP2020076097A (ja) * 2018-11-06 2020-05-21 三菱ケミカル株式会社 無溶剤型粘着剤組成物、無溶剤型粘着剤および粘着シート
WO2021161990A1 (ja) * 2020-02-10 2021-08-19 積水化学工業株式会社 粘着テープ

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