WO2022059408A1 - Composition adhésive utilisée dans un dispositif d'affichage d'image, film optique doté d'une couche adhésive, et dispositif d'affichage d'image - Google Patents

Composition adhésive utilisée dans un dispositif d'affichage d'image, film optique doté d'une couche adhésive, et dispositif d'affichage d'image Download PDF

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WO2022059408A1
WO2022059408A1 PCT/JP2021/030264 JP2021030264W WO2022059408A1 WO 2022059408 A1 WO2022059408 A1 WO 2022059408A1 JP 2021030264 W JP2021030264 W JP 2021030264W WO 2022059408 A1 WO2022059408 A1 WO 2022059408A1
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meth
pressure
sensitive adhesive
adhesive composition
monomer
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PCT/JP2021/030264
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English (en)
Japanese (ja)
Inventor
昌邦 藤田
武史 仲野
良介 荒井
悠太 渡邉
潤枝 長田
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日東電工株式会社
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Priority to KR1020237012408A priority Critical patent/KR20230066606A/ko
Priority to CN202180064024.1A priority patent/CN116194543A/zh
Publication of WO2022059408A1 publication Critical patent/WO2022059408A1/fr

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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
    • 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
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C09J133/04—Homopolymers or copolymers of esters
    • C09J133/06—Homopolymers or copolymers of esters of esters containing only carbon, hydrogen and oxygen, the oxygen atom being present only as part of the carboxyl radical
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • 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]
    • 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]
    • C09J7/381—Pressure-sensitive adhesives [PSA] based on macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
    • C09J7/385—Acrylic polymers
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09F—DISPLAYING; ADVERTISING; SIGNS; LABELS OR NAME-PLATES; SEALS
    • G09F9/00—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements
    • G09F9/30—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements
    • G09F9/301—Indicating arrangements for variable information in which the information is built-up on a support by selection or combination of individual elements in which the desired character or characters are formed by combining individual elements flexible foldable or roll-able electronic displays, e.g. thin LCD, OLED
    • 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
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature

Definitions

  • the present invention relates to an adhesive composition used for an image display device, an optical film with an adhesive layer, and an image display device.
  • Various thin image display devices such as liquid crystal displays and organic EL displays usually have a laminated structure including an image forming layer such as a liquid crystal layer and an organic EL light emitting layer and one or more optical films. ..
  • a pressure-sensitive adhesive composition is generally used for joining the layers constituting the image display device.
  • an optical film composed of a plurality of layers for example, a polarizing plate composed of a polarizing element and a polarizing element protection film, an optical film composed of a polarizing plate and a retardation film, and the like, the plurality of said. Layers may be joined with an adhesive composition.
  • Patent Document 1 describes a (meth) acrylic copolymer having a specific (meth) acrylate unit having a side chain composed of an ether structure (alkyleneoxy group) as a constituent unit, and a pressure-sensitive adhesive containing the copolymer.
  • the agent composition is disclosed.
  • Patent Document 1 describes that the use of the pressure-sensitive adhesive composition can improve the flexibility of an image display device at room temperature (25 ° C.) and high temperature and high humidity (60 ° C., 90% RH).
  • the image display device may be used at a low temperature of about -20 ° C. Therefore, the pressure-sensitive adhesive composition used in the image display device is required to exhibit good properties even at low temperatures. Patent Document 1 does not consider the properties of the pressure-sensitive adhesive composition at low temperatures.
  • An object of the present invention is to provide a pressure-sensitive adhesive composition used in an image display device, which can exhibit good characteristics even at low temperatures.
  • the increase in the storage elastic modulus G'at a low temperature is suppressed to prevent the pressure-sensitive adhesive composition from becoming hard, and the adherend to which the pressure-sensitive adhesive composition comes into contact in an image display device, for example.
  • the pressure-sensitive adhesive composition contains a (meth) acrylic copolymer having a constituent unit to ensure the adhesive strength to the adherend while suppressing an increase in the storage elastic modulus G'at a low temperature.
  • the present invention A (meth) acrylic copolymer having a structural unit derived from at least one monomer selected from a cyclization polymerizable monomer and a urethane structure-containing (meth) acrylate monomer.
  • Adhesive composition used in image display devices, I will provide a.
  • the invention is:
  • the storage elastic modulus G'at -20 ° C is 2.0 ⁇ 10 6 Pa or less
  • Adhesive strength to PI film at -20 ° C is 8.0 N / 25 mm or more.
  • Adhesive composition used in image display devices, I will provide a.
  • the invention is: An optical film and an adhesive layer bonded to the optical film are provided.
  • the invention is: An image display device comprising the pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition of the present invention or the optical film with the pressure-sensitive adhesive layer of the present invention. I will provide a.
  • a pressure-sensitive adhesive composition used for an image display device which can exhibit good properties even at a low temperature, is achieved.
  • FIG. 1 is a cross-sectional view schematically showing an example of an optical film with an adhesive layer of the present invention.
  • FIG. 2 is a cross-sectional view schematically showing another example of the optical film with an adhesive layer of the present invention.
  • FIG. 3 is a cross-sectional view schematically showing an example of the image display device of the present invention.
  • the pressure-sensitive adhesive composition (A) of the present embodiment is a pressure-sensitive adhesive composition used in an image display device, and is a cyclization-polymerizable monomer and a urethane structure-containing (meth) acrylate monomer (hereinafter, “urethane-containing (meth) acrylic”. It contains a (meth) acrylic copolymer (B) having a structural unit (C) derived from at least one monomer selected from (described as "monomer”).
  • the pressure-sensitive adhesive composition (A) is usually an acrylic pressure-sensitive adhesive composition.
  • the term "(meth) acrylic” means acrylic and methacrylic.
  • (meth) clearate” is meant acrylate and methacrylate.
  • the cyclizable polymerizable monomer does not have a ring structure in the state of the monomer, but has a ring structure in the state of the structural unit derived from the monomer (in other words, formed by the polymerization of the monomer). ..
  • the structural unit (C) derived from the cyclizable polymerizable monomer has a ring structure.
  • the (meth) acrylic copolymer (B) has a structural unit (C) having a ring structure.
  • the bulkiness of the ring structure reduces the density of the (meth) acrylic copolymer (B) in the pressure-sensitive adhesive composition (A) and inhibits the regular arrangement of the copolymer (B) in the composition. Can be done.
  • the increase in the storage elastic modulus G'of the pressure-sensitive adhesive composition (A) at a low temperature for example, 0 ° C. or lower and -25 ° C. or higher
  • the monomer already has a ring structure, it is less susceptible to the influence of steric hindrance due to the ring structure at the time of polymerization, and the arrangement of the structural unit (C) in the (meth) acrylic copolymer (B). It is presumed that the ability to make the above random is also contributing to the suppression of the increase in the storage elastic modulus G'at low temperatures.
  • the structural unit (C) may have a ring structure formed by the polymerization of the cyclizable polymerizable monomer in the main chain.
  • the ring structure since the ring structure is located in the main chain, the molecular weight between the entangled points in the (meth) acrylic copolymer (B) can be increased, and the action of suppressing the increase in the storage elastic modulus G'at a low temperature. Becomes more certain.
  • the number of the ring structures included in the structural unit (C) may be 1 or 2 or more, but is typically 1.
  • the structural unit (C) has a ring structure formed by the polymerization of the cyclization polymerizable monomer, and the ring structure may have a polar group.
  • polar groups are ether groups, amino groups, amide groups and sulfide groups.
  • the polar group is preferably an ether group, an amino group or an amide group.
  • the polar group may form part of the skeleton of the ring structure.
  • the embodiment in which the ring structure has a polar group is particularly suitable for improving the adhesive force at a low temperature on an adherend such as a PI film.
  • the number of polar groups contained in the ring structure is, for example, 1 to 4, and may be 1 to 2.
  • the ring structure may be, for example, a 4-membered ring, a 5-membered ring, a 6-membered ring, a 7-membered ring, or an 8-membered ring, preferably a 5-membered ring or a 6-membered ring.
  • the cyclized polymerizable monomer may have two or more polymerizable groups. Even if the at least one polymerizable group selected from the two or more polymerizable groups is a group that forms the main chain of the (meth) acrylic copolymer (B) by polymerization, the ring of the structural unit (C) is obtained by polymerization. It may be a group forming a structure. Further, at least one polymerizable group selected from two or more polymerizable groups has a main chain and a structure constituting the (meth) acrylic copolymer (B) by polymerization with another one or two or more polymerizable groups. It may be a group forming both of the ring structures of the unit (C).
  • the cyclization polymerizable monomer has a polymerizable group that constitutes the main chain of the (meth) acrylic copolymer (B) by polymerization and a polymerizable group that constitutes the ring structure of the structural unit (C) by polymerization. May be.
  • polymerizable groups examples are vinyl groups and allyl groups.
  • the polymerizable group is not limited to the above example.
  • the cyclization polymerizable monomer may be a (meth) acrylate monomer.
  • the (meth) acrylate monomer may have a polymerizable group not only in its main chain but also in its side chain (the polymerizable group of the main chain is usually a vinyl group).
  • the main chain and the side chain of the monomer mean a portion located in the main chain and a portion located in the side chain in the polymer formed by the polymerization of the monomer, respectively.
  • the cyclizable polymerizable monomer may be 2- (allyloxymethyl) acrylate represented by the following formula (1) (hereinafter referred to as “AOMA”).
  • AOMA is a kind of (meth) acrylate monomer.
  • AOMA has two polymerizable groups. The two polymerizable groups form a main chain constituting the (meth) acrylic copolymer (B) by polymerization of AOMA and another monomer (the other monomer contains another AOMA), and the said A ring structure can be formed in the main chain by polymerization between two polymerizable groups.
  • the structural unit (C) derived from AOMA has a ring structure which is a 5-membered ring in the main chain.
  • the ring structure has one polar group, and the polar group is an ether group constituting the skeleton of the ring structure.
  • the (meth) acrylic copolymer (B) having the structural unit (C) derived from AOMA has an ether group in the main chain. Having an ether group in the main chain enables further increase in the molecular weight between entangled points in the (meth) acrylic copolymer (B), for example.
  • the ether group of the main chain can function as a hydrogen bond acceptor in a state where it is not so affected by steric hindrance by other side chains. Therefore, it is more reliable to secure the adhesive strength of the pressure-sensitive adhesive composition at a low temperature.
  • the urethane-containing (meth) acrylic monomer typically has a urethane structure in its side chain.
  • the at least one monomer contains a urethane-containing (meth) acrylic monomer
  • the (meth) acrylic copolymer (B) has a high-density polar structure called a urethane structure (-COO-NH-) in the side chain. ..
  • its distribution in the pressure-sensitive adhesive composition is more uniform than, for example, when the pressure-sensitive adhesive composition contains a polyurethane polymer.
  • the high-density polar structure in the side chain reduces the density of the (meth) acrylic copolymer (B) in the pressure-sensitive adhesive composition (A) due to the repulsive force between the polar structures, and at the same time, the copolymer in the composition. It can inhibit the regular sequence of (B). As a result, it is presumed that the increase in the storage elastic modulus G'at a low temperature is suppressed for the pressure-sensitive adhesive composition (A). Further, the polar structure is suitable for improving the adhesive force to the adherend at a low temperature.
  • the urethane structure of the urethane-containing (meth) acrylic monomer is typically located in the side chain of the monomer.
  • the COO group of the acrylic acid ester structure in the urethane-containing (meth) acrylic monomer and the urethane structure closest to the COO group may be connected by an alkylene group having 1 to 5 carbon atoms.
  • the carbon number of the alkylene group may be 4 or less, 3 or less, and further may be 2 or less. According to the studies by the present inventors, in the above case, the distance between the COO group of the acrylic acid ester structure and the urethane structure does not become excessively large, so that the action of the urethane structure becomes more reliable.
  • the alkylene group may be linear or may have a branch.
  • the urethane-containing (meth) acrylic monomer may be an acrylic acid-2-butylcarbamoyloxyethyl ester represented by the following formula (2).
  • the glass transition temperature (Tg) when each monomer is homopolymer is, for example, ⁇ 80 to 100 ° C., even if it is ⁇ 70 to 90 ° C. good.
  • Tg of a polymer is defined as the temperature at which tan ⁇ (tangent loss) obtained by evaluation of dynamic viscoelasticity with respect to the polymer shows a peak.
  • the ratio of the structural unit (C) to all the structural units of the (meth) acrylic copolymer (B) is, for example, 0.5 to 80% by weight, 1 to 40% by weight, and further 2 to 20% by weight. There may be.
  • the (meth) acrylic copolymer (B) may have a structural unit derived from the (meth) acrylic monomer (a) having an alkyl group having 4 to 30 carbon atoms in the side chain. It may have a constituent unit as a main unit. The alkyl group may be linear or may have a branch.
  • the (meth) acrylic copolymer (B) may have one or more structural units derived from the (meth) acrylic monomer (a).
  • the (meth) acrylic monomer (a) is, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate.
  • the "main unit” occupies, for example, 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 94% by mass or more, among all the constituent units of the polymer. Means a unit.
  • the upper limit of the ratio occupied by the main unit is, for example, 99% by mass or less.
  • the (meth) acrylic copolymer (B) may have a structural unit derived from the (meth) acrylic monomer (a) having a long-chain alkyl group in the side chain.
  • the structural unit can contribute, for example, to lower the storage elastic modulus G'of the pressure-sensitive adhesive composition (A) at low to high temperatures.
  • the structural unit is, for example, n-dodecyl (meth) acrylate (lauryl (meth) acrylate).
  • the term "long-chain alkyl group” means an alkyl group having 6 to 30 carbon atoms.
  • the (meth) acrylic copolymer (B) has a structural unit derived from the (meth) acrylic monomer (a) whose Tg is in the range of ⁇ 70 ° C. to ⁇ 20 ° C. when homopolymerized. May be. In this case, an increase in the storage elastic modulus G'at a low temperature can be more reliably suppressed.
  • the structural unit is, for example, 2-ethylhexyl acrylate.
  • the (meth) acrylic copolymer (B) may have a structural unit other than the structural unit derived from the (meth) acrylic monomer (a).
  • the structural unit is derived from a cyclizable polymerizable monomer and / or a urethane-containing (meth) acrylic monomer, and a monomer (b) copolymerizable with the (meth) acrylic monomer (a).
  • the (meth) acrylic copolymer (B) may have one or more of the constituent units.
  • the monomer (b) is, for example, a (meth) acrylic monomer (c) having a hydroxyl group.
  • the (meth) acrylic monomer (c) is, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate. , 8-Hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, hydroxyalkyl (meth) acrylate such as 12-hydroxylauryl (meth) acrylate, and (4-hydroxymethylcyclohexyl) -methyl acrylate.
  • the (meth) acrylic monomer (c) is preferably 2-hydroxyethyl (meth) acrylate or 4-hydroxybutyl (meth) acrylate because the durability of the pressure-sensitive adhesive composition (A) can be improved.
  • the monomer (b) may be a carboxyl group-containing monomer, an amino group-containing monomer, or an amide group-containing monomer.
  • the carboxyl group-containing monomer is, for example, (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid.
  • the amino group-containing monomer is, for example, N, N-dimethylaminoethyl (meth) acrylate or N, N-dimethylaminopropyl (meth) acrylate.
  • the amide group-containing monomer is, for example, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropylacrylamide, N-methyl (meth) acrylamide, N-.
  • the monomer (b) may be a polyfunctional monomer.
  • the gel fraction of the pressure-sensitive adhesive composition (A) can be adjusted and the cohesive force can be controlled.
  • the polyfunctional monomer include hexanediol di (meth) acrylate (1,6-hexanediol di (meth) acrylate), butanediol di (meth) acrylate, and (poly) ethylene glycol di (meth) acrylate.
  • Poly propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethyl propantri
  • Polyfunctional acrylates such as meth) acrylates, tetramethylol methanetri (meth) acrylates, allyl (meth) acrylates, vinyl (meth) acrylates, epoxy acrylates, polyester acrylates, urethane acrylates; and divinylbenzene.
  • the polyfunctional acrylate is preferably 1,6-hexanediol diacrylate or dipentaerythritol hexa (meth) acrylate.
  • Examples of the monomer (b) other than those described above include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, and (meth) acrylic.
  • (Meta) acrylic acid alkoxyalkyl esters such as 3-methoxypropyl acid, 3-ethoxypropyl (meth) acrylic acid, 4-methoxybutyl (meth) acrylic acid, 4-ethoxybutyl (meth) acrylic acid; (meth) acrylic Epoxy group-containing monomers such as glycidyl acid, (meth) methyl glycidyl acrylate; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphate group-containing monomers; (meth) cyclopentyl acrylate, (meth).
  • (Meta) acrylates having group hydrocarbon groups Vinyl esters such as vinyl acetate and vinyl propionate; Aromatic vinyl compounds such as styrene and vinyl toluene; Olefins or dienes such as ethylene, propylene, butadiene, isoprene and isobutylene Vinyl ethers such as vinyl alkyl ether; vinyl chloride.
  • the total content of the structural units derived from the functional monomer may be, for example, 20% by mass or less, 10% by mass or less, 8% by mass or less, and further 5% by mass or less.
  • the (meth) acrylic copolymer (B) has the structural unit
  • the total content of the structural unit is, for example, 0.01% by mass or more, and may be 0.05% by mass or more.
  • the total content of the structural units derived from the other monomer (b) in the (meth) acrylic copolymer (B) is, for example, 30% by mass or less, may be 10% by mass or less, and may be 0. It may be mass% (not including the structural unit).
  • the (meth) acrylic copolymer (B) can be formed by polymerizing a group of monomers containing the above-mentioned monomers by a known method.
  • the monomer and a partial polymer of the monomer may be polymerized.
  • the polymerization can be carried out by, for example, solution polymerization, emulsion polymerization, bulk polymerization, thermal polymerization, or active energy ray polymerization. Solution polymerization and active energy ray polymerization are preferable for the polymerization because the pressure-sensitive adhesive composition (A) having excellent optical transparency can be formed.
  • the polymerization is preferably carried out while avoiding contact between the monomer and / or the partial polymer and oxygen, and for this purpose, for this purpose, for example, polymerization in an inert gas atmosphere such as nitrogen, or oxygen is added by a resin film or the like. Polymerization in a cut-off state can be adopted.
  • the (meth) acrylic copolymer (B) to be formed may be in any form such as a random copolymer, a block copolymer, a graft copolymer or the like, but the (meth) acrylic copolymer (B) may be formed. From the viewpoint of increasing the degree of dispersion of the structural unit (C) in the above, a random copolymer may be used.
  • the polymerization system forming the (meth) acrylic copolymer (B) may contain one kind or two or more kinds of polymerization initiators.
  • the type of the polymerization initiator can be selected by the polymerization reaction, and may be, for example, a photopolymerization initiator or a thermal polymerization initiator.
  • Solvents used for solution polymerization are, for example, esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; cyclohexane, Aromatic hydrocarbons such as methylcyclohexane; ketones such as methylethylketone and methylisobutylketone.
  • the solvent is not limited to the above example.
  • the solvent may be a mixed solvent of two or more kinds of solvents.
  • the polymerization initiator used for solution polymerization is, for example, an azo-based polymerization initiator, a peroxide-based polymerization initiator, or a redox-based polymerization initiator.
  • the peroxide-based polymerization initiator is, for example, dibenzoyl peroxide or t-butyl permalate.
  • the azo-based polymerization initiator disclosed in JP-A-2002-69411 is preferable.
  • the azo-based polymerization initiator is, for example, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis (2-methylpropion).
  • the polymerization initiator is not limited to the above example.
  • the amount of the azo-based polymerization initiator used is, for example, 0.05 to 0.5 parts by weight, or 0.1 to 0.3 parts by weight, based on 100 parts by weight of the total amount of the monomers.
  • the active energy rays used for polymerization are, for example, ⁇ rays, ⁇ rays, ⁇ rays, neutron rays, ionizing radiation such as electron beams, and ultraviolet rays.
  • the active energy ray is preferably ultraviolet light.
  • Polymerization by irradiation with ultraviolet rays is also called photopolymerization.
  • the polymerization system of active energy ray polymerization typically contains a photopolymerization initiator.
  • the polymerization conditions of the active energy polymerization are not limited as long as the (meth) acrylic polymer is formed.
  • the photopolymerization initiator examples include a benzoin ether-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, an ⁇ -ketol-based photopolymerization initiator, an aromatic sulfonyl chloride-based photopolymerization initiator, and a photoactive oxime-based photopolymerization initiator.
  • the photopolymerization initiator is not limited to the above example.
  • benzoin ether-based photopolymerization initiator examples include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethan-1-one, and anisolemethyl. It is ether.
  • acetophenone-based photopolymerization initiator examples include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, 4-phenoxydichloroacetophenone, and 4- (t-butyl) dichloro. Acetophenone.
  • the ⁇ -ketol-based photopolymerization initiator is, for example, 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one.
  • the aromatic sulfonyl chloride-based photopolymerization initiator is, for example, 2-naphthalene sulfonyl chloride.
  • the photoactive oxime-based photopolymerization initiator is, for example, 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.
  • the benzoin-based photopolymerization initiator is, for example, benzoin.
  • the benzyl-based photopolymerization initiator is, for example, benzyl.
  • Benzophenone-based photopolymerization initiators are, for example, benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and ⁇ -hydroxycyclohexylphenylketone.
  • the ketal-based photopolymerization initiator is, for example, benzyldimethyl ketal.
  • the thioxanthone-based photopolymerization initiator is, for example, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.
  • the amount of the photopolymerization initiator used is, for example, 0.01 to 1 part by weight with respect to 100 parts by weight of the total amount of the monomer, and may be 0.05 to 0.5 part by weight.
  • the polyfunctional monomer (polyfunctional acrylate or the like) which is the monomer (b) can be used for both solvent type and active energy ray curable type pressure-sensitive adhesive compositions
  • the polyfunctional monomer and the photopolymerization initiator are used for the solvent-type pressure-sensitive adhesive composition, for example, the pressure-sensitive adhesive composition by irradiation with active energy rays after removing the solvent by heat drying. The curing may proceed.
  • the weight average molecular weight (Mw) of the (meth) acrylic copolymer (B) is, for example, 1 million to 3 million, and from the viewpoint of the durability and heat resistance of the pressure-sensitive adhesive composition (A), 1.1 million to 3 million. It may be 2 million, or even 1.1 million to 1.8 million.
  • the molecular weight distribution (Mw / number average molecular weight (Mn)) of the (meth) acrylic copolymer (B) is, for example, 2 to 20, and may be 4 to 15.
  • Mw and Mn of a polymer and an oligomer in this specification are values (polystyrene conversion) based on the measurement of GPC (gel permeation chromatography).
  • the content of the (meth) acrylic copolymer (B) in the pressure-sensitive adhesive composition (A) is, for example, 50% by mass or more, 60% by mass or more, and further 70% by mass or more in terms of solid content ratio. May be good.
  • the pressure-sensitive adhesive composition (A) may further contain a (meth) acrylic oligomer.
  • the inclusion of the (meth) acrylic oligomer reduces the entanglement of the molecular chains of the (meth) acrylic copolymer (B) with each other, whereby the storage elastic modulus G of the pressure-sensitive adhesive composition (A) at a low temperature is reduced. 'The rise can be suppressed more reliably.
  • the (meth) acrylic oligomer can have the same composition as the above-mentioned (meth) acrylic copolymer (B) except that the Mw is different. However, the (meth) acrylic oligomer does not have to have the structural unit (C) derived from the cyclization polymerizable monomer and the urethane-containing (meth) acrylic monomer.
  • the Mw of the (meth) acrylic oligomer is, for example, 1000 or more, 2000 or more, 3000 or more, and further may be 4000 or more.
  • the upper limit of Mw of the (meth) acrylic oligomer is, for example, 30,000 or less, and may be 15,000 or less, 10,000 or less, and further 7,000 or less.
  • the (meth) acrylic oligomer has, for example, one or more structural units derived from each of the following monomers: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate.
  • the (meth) acrylic oligomer may have a structural unit derived from an acrylic monomer having a relatively bulky structure.
  • the acrylic monomer is, for example, an alkyl (meth) acrylate having an alkyl group having a branched structure such as isobutyl (meth) acrylate and t-butyl (meth) acrylate; cyclohexyl (meth) acrylate and isobornyl (meth) acrylate.
  • Ester of (meth) acrylic acid such as dicyclopentanyl (meth) acrylate and alicyclic alcohol; aryl (meth) acrylate such as phenyl (meth) acrylate and benzyl (meth) acrylate.
  • the acrylic monomer preferably has a cyclic structure, and more preferably has two or more cyclic structures. Further, when irradiation with ultraviolet rays is carried out at the time of polymerization of the (meth) acrylic oligomer and / or at the time of forming the pressure-sensitive adhesive composition, the progress of the polymerization and / or the formation is not easily hindered.
  • the body preferably has no unsaturated bond, and for example, an alkyl (meth) acrylate having an alkyl group having a branched structure, an ester of (meth) acrylic acid and an alicyclic alcohol can be used.
  • the (meth) acrylic oligomer examples include a copolymer of butyl acrylate, methyl acrylate and acrylic acid, a polymer of cyclohexyl methacrylate and isobutyl methacrylate, a polymer of cyclohexyl methacrylate and isobornyl methacrylate, and cyclohexyl.
  • the above-mentioned polymerization method of the (meth) acrylic copolymer (B) can be adopted.
  • the blending amount thereof is, for example, 70 parts by weight or less with respect to 100 parts by weight of the (meth) acrylic copolymer (B), and 50 parts by weight. It may be 10 parts or less, and further 40 parts by weight or less.
  • the lower limit of the blending amount is, for example, 1 part by weight or more, 2 parts by weight or more, and further 3 parts by weight or more with respect to 100 parts by weight of the (meth) acrylic copolymer (B).
  • the (meth) acrylic oligomer can be used in both solvent-type and active energy ray-curable type pressure-sensitive adhesive compositions. However, when it is used for an active energy ray-curable pressure-sensitive adhesive composition and the (meth) acrylic oligomer is dissolved in a solvent, the mixture is mixed with the (meth) acrylic oligomer. For example, after removing the solvent by heat drying, curing by irradiation with active energy rays may proceed.
  • the pressure-sensitive adhesive composition (A) may further contain a cross-linking agent.
  • the use of the cross-linking agent improves the cohesive force of the pressure-sensitive adhesive composition (A).
  • the cross-linking agent is, for example, an organic cross-linking agent or a polyfunctional metal chelate.
  • the organic cross-linking agent is, for example, an isocyanate-based cross-linking agent, a peroxide-based cross-linking agent, an epoxy-based cross-linking agent, or an imine-based cross-linking agent.
  • the polyfunctional metal chelate has a structure in which a polyvalent metal and an organic compound are covalently bonded or coordinated.
  • the polyvalent metals are, for example, Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn and Ti. be.
  • Atoms in organic compounds to which polyvalent metals are covalently or coordinated are typically oxygen atoms.
  • the organic compound is, for example, an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, or a ketone compound.
  • the organic cross-linking agent and the polyfunctional metal chelate can be used for both solvent-type and active energy ray-curable type pressure-sensitive adhesive compositions.
  • the cross-linking agent is preferably a peroxide-based cross-linking agent, an isocyanate-based cross-linking agent, and more preferably a peroxide-based cross-linking agent. Since the peroxide-based cross-linking agent promotes cross-linking between the side chains of the (meth) acrylic polymer, in the cross-linking with the peroxide-based cross-linking agent, the cross-linking of the molecular chain after the cross-linking is compared with the cross-linking with the isocyanate-based cross-linking agent. The degree of freedom increases.
  • the isocyanate-based cross-linking agent is preferably a bifunctional cross-linking agent.
  • Cross-linking with a bifunctional cross-linking agent forms a two-dimensional cross-linking structure.
  • the degree of freedom of the molecular chain after cross-linking can be increased as compared with the trifunctional cross-linking agent that forms a three-dimensional cross-linked structure.
  • an isocyanate-based cross-linking agent When an isocyanate-based cross-linking agent is used, the balance between durability and storage elastic modulus G'at low temperature can be improved by using a bifunctional cross-linking agent and a tri-functional cross-linking agent in combination. good.
  • a peroxide-based cross-linking agent and an isocyanate-based cross-linking agent may be used in combination.
  • the polyfunctional monomer which is the above-mentioned monomer (b) and the cross-linking agent may be used in combination.
  • the blending amount thereof is, for example, 0.01 to 10 parts by weight, and 0.1 to 5 parts by weight, based on 100 parts by weight of the (meth) acrylic copolymer (B). It may be 0.1 to 3 parts by weight.
  • the blending amount thereof is, for example, 0.2 to 5 parts by weight with respect to 100 parts by weight of the (meth) acrylic copolymer (B), and 0.5 to 0.5 parts by weight. It may be 3 parts by weight.
  • the weight ratio of the peroxide-based cross-linking agent to the isocyanate-based cross-linking agent is, for example, 1.2 or more, 1.5 or more, and further 2 or more. May be. Further, the upper limit of the weight ratio is, for example, 500 or less, and may be 300 or less, and further may be 200 or less.
  • the pressure-sensitive adhesive composition (A) may contain other additives.
  • Additives include, for example, silane coupling agents, polyether compounds (polyalkylene glycols such as polypropylene glycol), colorants such as pigments and dyes, surfactants, plasticizers, tackifiers, and surface lubricants. , Leveling agent, softener, antioxidant, antiaging agent, light stabilizer, ultraviolet absorber, polymerization inhibitor, antistatic agent (alkali metal salt which is an ionic compound, ionic liquid, ionic solid, etc.), inorganic filling Materials, organic fillers, powders such as metal powders, particles, and foil-like substances.
  • the pressure-sensitive adhesive composition (A) may have the following characteristics.
  • the storage elastic modulus G'at ⁇ 20 ° C. is, for example, 2.0 ⁇ 10 6 Pa or less, 1.0 ⁇ 10 6 Pa or less, 5.0 ⁇ 10 5 Pa or less, 3.0 ⁇ 10 5 Pa or less, It may be 2.5 ⁇ 10 5 Pa or less, 2.0 ⁇ 10 5 Pa or less, and further 1.6 ⁇ 10 5 Pa or less.
  • the lower limit of the storage elastic modulus G'at ⁇ 20 ° C. is, for example, 1.0 ⁇ 10 4 Pa or more.
  • the storage elastic modulus G'at 25 ° C. is, for example, 1.0 ⁇ 10 5 Pa or less, 8.0 ⁇ 10 4 Pa or less, 5.0 ⁇ 10 4 Pa or less, 4.0 ⁇ 10 4 Pa or less, and further. May be 3.0 ⁇ 10 4 Pa or less.
  • the lower limit of the storage elastic modulus G'at 25 ° C. is, for example, 1.0 ⁇ 10 4 Pa or more.
  • the adhesive strength to the PI film at ⁇ 20 ° C. is, for example, 8.0 N / 25 mm or more, 10.0 N / 25 mm or more, 12.0 N / 25 mm or more, and further may be 13.0 N / 25 mm or more.
  • the upper limit of the adhesive strength is, for example, 30 N / 25 mm or less.
  • the adhesive strength to the PI film is evaluated in the state of the pressure-sensitive adhesive composition (A) as a layer, in other words, the state of the pressure-sensitive adhesive layer. From this point of view, it is the adhesive strength when the pressure-sensitive adhesive layer is used.
  • the adhesive strength to the PI film at 25 ° C. is, for example, 2.0 N / 25 mm or more, 3.0 N / 25 mm or more, 4.0 N / 25 mm or more, 6.0 N / 25 mm or more, and further 8.0 N / 25 mm or more. There may be.
  • the upper limit of the adhesive strength is, for example, 30 N / 25 mm or less.
  • the adhesive force to the PI film at ⁇ 20 ° C. may be larger than the adhesive force to the PI film at 25 ° C.
  • the pressure-sensitive adhesive composition (A) can simultaneously satisfy the above-mentioned ranges for the storage elastic modulus G'at ⁇ 20 ° C. and the adhesive strength against the PI film at ⁇ 20 ° C. Further, the pressure-sensitive adhesive composition (A) can simultaneously satisfy the above-mentioned ranges with respect to the storage elastic modulus G'at 25 ° C. and the adhesive strength to the PI film at 25 ° C.
  • the Tg of the pressure-sensitive adhesive composition (A) is, for example, ⁇ 55 to ⁇ 30 ° C.
  • the lower limit of Tg may be ⁇ 50 ° C. or higher, ⁇ 45 ° C. or higher, and even ⁇ 40 ° C. or higher.
  • the upper limit of Tg may be ⁇ 35 ° C. or lower.
  • the gel fraction of the pressure-sensitive adhesive layer composition (A) is, for example, 55% or more, and may be 60% or more, 65% or more, 70% or more, and further 75% or more.
  • the upper limit of the gel fraction of the pressure-sensitive adhesive composition (A) is, for example, 95% or less, 90% or less, and further may be 85% or less. When the gel fraction of the pressure-sensitive adhesive composition (A) is in these ranges, the above-mentioned effects can be obtained more reliably.
  • the good properties of the pressure-sensitive adhesive composition at low temperature when incorporated into an image display device have a storage elastic modulus G'at ⁇ 20 ° C. It is also achieved by suppressing the rise and ensuring the adhesive strength to the PI film at ⁇ 20 ° C.
  • the storage elastic modulus G'at ⁇ 20 ° C. is 2.0 ⁇ 10 6 Pa or less
  • the adhesive force to the PI film at ⁇ 20 ° C. is 8.0 N / 25 mm or more.
  • the pressure-sensitive adhesive composition (D) used in the apparatus is disclosed.
  • the storage elastic modulus G'at ⁇ 20 ° C. and / or the adhesive force to the PI film at ⁇ 20 ° C. may be in the above-mentioned ranges in the description of the pressure-sensitive adhesive composition (A).
  • the storage elastic modulus G'at 25 ° C. and / or the pressure-sensitive adhesive force against the PI film at 25 ° C. may be in the above-mentioned ranges in the description of the pressure-sensitive adhesive composition (A).
  • the pressure-sensitive adhesive composition (D) is usually an acrylic pressure-sensitive adhesive composition.
  • the pressure-sensitive adhesive composition (D) may contain a (meth) acrylic copolymer (B).
  • the pressure-sensitive adhesive composition (D) does not contain the (meth) acrylic copolymer (B), but may contain other (meth) acrylic polymer (E).
  • the (meth) acrylic polymer (E) is a (meth) acrylic copolymer (B) except that it does not have a structural unit (C) derived from a cyclizable polymerizable monomer and a urethane-containing (meth) acrylic monomer. In the above description, it may have a structural unit derived from each of the above-mentioned monomers.
  • the pressure-sensitive adhesive composition (D) may contain the oligomers, cross-linking agents, additives and the like described above in the description of the pressure-sensitive adhesive composition (A).
  • the pressure-sensitive adhesive composition (D) may have the same characteristics as the pressure-sensitive adhesive composition (A).
  • the types of the pressure-sensitive adhesive compositions (A) and (D) are, for example, an emulsion type, a solvent type (solution type), an active energy ray curing type, and a heat melting type (hot melt type). Of these, a solvent-type or active energy ray-curable pressure-sensitive adhesive composition is preferable, and from the viewpoint of productivity and easy formation of a thick pressure-sensitive adhesive layer, the active energy ray-curable pressure-sensitive adhesive composition is used. You may. However, the type of the pressure-sensitive adhesive composition is not limited to the above example.
  • the pressure-sensitive adhesive compositions (A) and (D) are compositions used in an image display device.
  • the image display device is typically an organic EL display or a liquid crystal display.
  • the image display device may be a flexible image display device, and the flexible image display device may be a foldable image display device or a rollable image display device that can be rolled up.
  • the image display device is not limited to the above example.
  • FIG. 1 shows an example of an optical film with an adhesive layer.
  • the optical film 1 (1A) with an adhesive layer of FIG. 1 is a film used for an image display device, and includes an adhesive layer 2 and an optical film 3.
  • the optical film 1A with an adhesive layer of FIG. 1 has a two-layer structure of an adhesive layer 2 and an optical film 3, and the adhesive layer 2 is bonded to one surface of the optical film 3.
  • the pressure-sensitive adhesive layer 2 contains the pressure-sensitive adhesive composition (A) or (D).
  • the pressure-sensitive adhesive layer 2 may be composed of the pressure-sensitive adhesive composition (A) or (D).
  • the thickness of the pressure-sensitive adhesive layer 2 is, for example, 1 to 200 ⁇ m, 5 to 150 ⁇ m, 10 to 100 ⁇ m, and further may be 10 to 50 ⁇ m.
  • the adhesive layer 2 can be formed as follows.
  • the pressure-sensitive adhesive composition is a solvent type, for example, a mixture of a (meth) acrylic copolymer and a solvent and, if necessary, a (meth) acrylic oligomer, a cross-linking agent, an additive, etc., is used as a base film. It is applied on top and dried to form the pressure-sensitive adhesive layer 2.
  • the pressure-sensitive adhesive composition is an active energy ray-curable type, for example, a monomer (group) that becomes a (meth) acrylic copolymer by polymerization and, if necessary, a partial polymer of the monomer (group).
  • the pressure-sensitive adhesive layer 2 can be formed.
  • the base film may be a film whose surface has been peeled off.
  • the pressure-sensitive adhesive layer 2 formed on the base film can be transferred to any layer.
  • the base film may be an optical film, and in this case, an optical film with an adhesive layer including the adhesive layer 2 can be obtained.
  • the base film may be a separator. Further, the pressure-sensitive adhesive layer 2 formed on the base film may be bonded (bonded) to the optical film to obtain an optical film with a pressure-sensitive adhesive layer including the pressure-sensitive adhesive layer 2.
  • a known method can be adopted for applying the above mixture to the base film.
  • the application is, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, extruded coat by die coater, etc. Can be carried out by.
  • the mixture to be applied to the base film preferably has a viscosity suitable for handling and coating.
  • the pressure-sensitive adhesive composition is an active energy ray-curable type, it is preferable that the mixture contains a partial polymer of a monomer (group).
  • the release film that can be used as the base film is, for example, a resin film whose surface has been peeled off with a silicone compound.
  • the drying temperature of the mixture is, for example, 40 to 200 ° C, 50 to 180 ° C, and further 70 to 170 ° C.
  • the drying time of the mixture is, for example, 5 seconds to 20 minutes, 5 seconds to 10 minutes, and further 10 seconds to 5 minutes.
  • the optical film 3 is, for example, a polarizing film, a retardation film, and a laminated film or an optical laminate including a polarizing film and / or a retardation film.
  • the optical film 3 is not limited to the above example as long as it is used for an image display device.
  • the optical film 3 may include a film made of glass.
  • the thickness of the optical film 3 is, for example, 1 ⁇ m or more, 5 ⁇ m or more, and may be 25 ⁇ m or more.
  • the upper limit of the thickness of the optical film 3 is, for example, 200 ⁇ m or less.
  • the polarizing film contains a polarizing element.
  • a splitter protective film may be bonded to at least one surface of the splitter. Any adhesive or adhesive can be used to bond the stator to the polarizing element protective film.
  • the splitter is typically a polyvinyl alcohol (PVA) film in which iodine is oriented by various methods such as stretching in the air (dry stretching), stretching in boric acid in water, and coating.
  • the retardation film is a film having birefringence in the in-plane direction and / or the thickness direction.
  • the retardation film is, for example, a stretched resin film or a film in which a liquid crystal material is oriented and immobilized.
  • the retardation film may be, for example, a ⁇ / 4 plate, a ⁇ / 2 plate, an antireflection retardation film (see, for example, paragraphs 0221, 0222, 0228 of JP2012-133303A), and a retardation film for viewing angle compensation (see paragraphs 0221, 0222, 0228).
  • paragraphs 0225 and 0226 of JP2012-133303 see, for example, paragraph 0227 of JP2012-13303
  • the retardation film is not limited to the above example as long as it has birefringence in the in-plane direction and / or the thickness direction.
  • the retardation value of the retardation film, the arrangement angle, the three-dimensional birefringence, and whether it is a single layer or a multilayer are not limited.
  • a known film can be used as the retardation film.
  • the thickness of the retardation film is, for example, 50 ⁇ m or less, 20 ⁇ m or less, 10 ⁇ m or less, and further may be 1 to 9 ⁇ m.
  • FIG. 2 shows another example of the optical film with an adhesive layer.
  • the optical film 1 (1B) with an adhesive layer of FIG. 2 is a film used for an image display device, and the bonding surface between the adhesive layer 2, the optical film 3, and the optical film 3 in the adhesive layer 2 is It is provided with a separator 4 arranged on the opposite surface.
  • the optical film 1B with an adhesive layer of FIG. 2 has a three-layer structure of an optical film 3, an adhesive layer 2, and a separator 4.
  • the separator 4 has a function of protecting the pressure-sensitive adhesive layer 2 during distribution and storage of the optical film 1B with a pressure-sensitive adhesive layer, and is peeled off when the optical film 1B with a pressure-sensitive adhesive is used.
  • the separator 4 is typically a resin film.
  • the resin constituting the separator 4 is, for example, polyester such as PET, polyolefin such as polyethylene and polypropylene, polycarbonate, acrylic, polystyrene, polyamide, and polyimide.
  • the surface of the separator 4 in contact with the pressure-sensitive adhesive layer 2 may be peeled off.
  • the peeling treatment can be carried out with, for example, a silicone compound.
  • the separator 4 is not limited to the above example.
  • the thickness of the separator 4 is, for example, 20 ⁇ m to 100 ⁇ m.
  • the optical film 1 with an adhesive may include layers other than those described above.
  • the other layer is, for example, a protective film arranged on the surface of the optical film 3 opposite to the surface of the pressure-sensitive adhesive layer 2.
  • the protective film can be bonded to the optical film 3 by any pressure-sensitive adhesive layer including the pressure-sensitive adhesive layer 2.
  • the protective film is typically a resin film.
  • the resin constituting the protective film is, for example, polyester such as PET, polyolefin such as polyethylene and polypropylene, acrylic and cycloolefin.
  • the protective film is not limited to the above example.
  • the protective film may be a glass film or a laminated film including a glass film.
  • the thickness of the protective film is, for example, 5 to 60 ⁇ m, 10 to 40 ⁇ m, and may be 10 to 30 ⁇ m.
  • the protective film may be subjected to surface treatment such as antiglare, antireflection, and antistatic.
  • the other layer may be, for example, an antistatic layer.
  • the antistatic layer are an ionic compound-containing layer, a conductive particle-containing layer, and a conductive polymer-containing layer.
  • the optical film 1 with an adhesive layer can be distributed and stored, for example, as a wound body obtained by winding the strip-shaped film 1 or as a laminated body of the sheet-fed film 1.
  • the optical film 1 with an adhesive layer is for an image display device.
  • FIG. 3 An example of the image display device is shown in FIG.
  • the image display device 8 shown in FIG. 3 has an optical laminate in which a substrate 6, an image forming layer (organic EL layer) 5, an adhesive layer 2, an optical film 3, and a protective film 7 are laminated in this order.
  • the image display device 8 includes an adhesive layer 2.
  • the image display device 8 includes an optical film 1 with an adhesive layer including an adhesive layer 2 and an optical film 3.
  • the substrate 6 and the image forming layer 5 may have the same configurations as the substrate and the image forming layer included in the known organic EL display.
  • the image display device 8 can obtain good characteristics such as impact resistance and bending resistance even at low temperatures.
  • the image display device 8 in FIG. 3 is an organic EL display.
  • the image display device 8 is not limited to the above example.
  • the image display device 8 may have any configuration as long as it includes the pressure-sensitive adhesive layer 2 or the optical film 1 with the pressure-sensitive adhesive layer.
  • the image display device 8 may be a flexible image display device.
  • the Mw of the (meth) acrylic copolymer A1 was 1.33 million, and the molecular weight distribution Mw / Mn was 11.8.
  • the Mw and Mn of the (meth) acrylic copolymer and the (meth) acrylic oligomer prepared in each synthetic example were measured by GPC under the following measurement conditions.
  • Table 1 shows the composition (monomer charging ratio), Mw and molecular weight distribution (Mw / Mn) of the (meth) acrylic copolymer and the (meth) acrylic oligomer prepared in each synthetic example.
  • Mw and Mw / Mn "-" indicates unmeasured.
  • the entire surface was irradiated with ultraviolet rays under the conditions of an illuminance of 4 mW / cm 2 and a light intensity of 1200 mJ / cm 2 , and the pressure-sensitive adhesive composition was photo-cured to form a layer (thickness 20 ⁇ m) of the pressure-sensitive adhesive composition.
  • a plurality of layers of each of the formed pressure-sensitive adhesive compositions were laminated to obtain a laminated film (thickness 2 mm) of each pressure-sensitive adhesive composition of Examples and Comparative Examples.
  • the laminated film was punched into a circle having a diameter of 7.9 mm to obtain a test piece.
  • dynamic viscoelasticity measurements were performed on the obtained test pieces to evaluate the peak temperatures of storage elastic modulus G'at -20 ° C, storage elastic modulus G'at 25 ° C, and tan ⁇ (tangent loss). did.
  • tan ⁇ is obtained as the ratio G'' / G'of the loss elastic modulus G'' to the storage elastic modulus G'.
  • the peak temperature of the evaluated tan ⁇ was taken as Tg of the pressure-sensitive adhesive composition.
  • the Advanced Rheometric Expansion System (ARES) manufactured by Rheometric Scientific was used for the dynamic viscoelasticity measurement.
  • the measurement conditions are as follows. (Measurement condition) Deformation mode: Torsion measurement temperature: -70 to 150 ° C Temperature rise rate: 5 ° C / min
  • the gel fraction was evaluated as follows. First, about 0.2 g of the pressure-sensitive adhesive composition was scraped from the laminated film prepared above to obtain small pieces. Next, the obtained small pieces were wrapped with a stretched porous membrane of polytetrafluoroethylene (NTF1122 manufactured by Nitto Denko, average pore size 0.2 ⁇ m) and tied with a kite string to obtain a test piece. Next, the weight W 1 of the obtained test piece was measured. Weight W 1 is the sum of the weights of the small pieces of the pressure-sensitive adhesive layer, the stretched porous membrane, and the kite string. The total weight W 0 of the stretched porous membrane and the kite string used was measured in advance.
  • NTF1122 polytetrafluoroethylene
  • Adhesive strength against PI film The evaluation of the adhesive strength to the PI film was carried out as follows. First, a PET film (50 ⁇ m) having a corona-treated surface is attached to the layer (thickness 20 ⁇ m) of the pressure-sensitive adhesive composition prepared above, and this is cut into strips having a width of 25 mm and a length of 100 mm. A test piece was obtained. The bonding was carried out so that the corona-treated surface was in contact with the above layer. Next, a test piece was attached to a PI film (Kapton manufactured by Toray DuPont, thickness 50 ⁇ m) fixed to the surface of a stainless steel plate to obtain a test sample.
  • PI film Kerpton manufactured by Toray DuPont, thickness 50 ⁇ m
  • the fixing of the PI film was carried out using a double-sided adhesive tape having sufficient adhesive strength so that the PI film would not peel off from the stainless steel plate during the peeling test described later.
  • the test pieces are bonded so that one end in the long side direction of the test piece becomes a free end without contacting the PI film over a length of 20 mm, and the pressure-sensitive adhesive composition in the test piece except for the free end.
  • the procedure was performed so that the entire exposed surface of the layer of the object was in contact with the PI film.
  • the temperature of the crimping roller having a mass of 2 kg specified in Japanese Industrial Standards (former Japanese Industrial Standards; JIS) Z0237: 2009 is applied. It was reciprocated once at 25 ° C.
  • a test sample that had been allowed to stand for 30 minutes after reciprocating the crimping roller was set in a tensile tester with a constant temperature bath.
  • the long side direction of the test piece coincides with the direction between the chucks of the testing machine, and one chuck of the testing machine grips the lead tape attached to the free end, and the other chuck holds the lead tape. It was carried out to grip the PI film and the stainless plate.
  • the environmental temperature of the tester and the test sample was controlled to each evaluation temperature (-20 ° C or 25 ° C; both had a relative humidity of 50 ⁇ 5%). After allowing to stand for 5 minutes after the environmental temperature reached the evaluation temperature, the test piece was peeled off from the PI film at a peeling angle of 180 ° and a test speed of 300 mm / min, and a 180 ° peeling test was carried out. After the start of the test, the first measured value of the peeled length of 10 mm was ignored, and then the average value of the peeled 70 mm length measured value was taken as the adhesive strength to the PI film.
  • the pressure-sensitive adhesive composition of the present invention can be used in an image display device.

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  • Chemical & Material Sciences (AREA)
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Abstract

L'invention concerne une composition adhésive comprenant un copolymère (méth)acrylique comportant un motif structural dérivé d'au moins un monomère choisi parmi un monomère polymérisable par cyclisation et un monomère (méth)acrylate contenant une structure uréthane. La composition adhésive est utilisée dans un dispositif d'affichage d'image, et peut présenter des propriétés intéressantes même à basse température. La composition adhésive selon l'invention peut être une composition dont le module d'élasticité de stockage G' à -20 °C est inférieur ou égal à 2,0 × 106 Pa, et la force adhésive à -20 °C par rapport à un film de polyimide est égale ou supérieure à 8,0 N/25 mm.
PCT/JP2021/030264 2020-09-17 2021-08-18 Composition adhésive utilisée dans un dispositif d'affichage d'image, film optique doté d'une couche adhésive, et dispositif d'affichage d'image WO2022059408A1 (fr)

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KR1020237012408A KR20230066606A (ko) 2020-09-17 2021-08-18 화상 표시 장치에 사용하는 점착제 조성물, 점착제층을 구비한 광학 필름 및 화상 표시 장치
CN202180064024.1A CN116194543A (zh) 2020-09-17 2021-08-18 用于图像显示装置的粘合剂组合物、带粘合剂层的光学膜及图像显示装置

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JP2020156440A JP2022050067A (ja) 2020-09-17 2020-09-17 画像表示装置に用いる粘着剤組成物、粘着剤層付き光学フィルム及び画像表示装置
JP2020-156440 2020-09-17

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WO2022059408A1 true WO2022059408A1 (fr) 2022-03-24

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JP2023154283A (ja) * 2022-04-06 2023-10-19 株式会社レゾナック 接着剤組成物、回路接続用接着剤フィルム、回路接続構造体及びその製造方法

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