Laminate and article comprising the laminate

Abstract

To provide a laminate having an adhesive layer having excellent adhesive strength and an article having the laminate.SOLUTION: There is provided a laminate which comprises an adhesive layer containing a copolymer and a cued product of a crosslinking agent and a base material, wherein the copolymer is a copolymer of a polymerizable composition comprising a (meth)acrylate monomer, a polar monomer and a mono- or di-functional urethane(meth)acrylate oligomer and the polymerizable composition comprises approximately 0.005 to approximately 0.50 pt.mass of the mono- or di-functional urethane(meth)acrylate oligomer based on 100 pts.mass of the total of the (meth)acrylate monomer and the polar monomer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to laminates and articles including the laminates. [Background technology]

[0002] BACKGROUND ART Conventionally, laminates such as adhesive tapes having an adhesive layer have been developed.

[0003] Patent Document 1 (JP 2013-157420 A) describes an adhesive tape for processing semiconductor wafers and the like, which has a base layer and an adhesive layer, in which the adhesive layer contains a base polymer, an isocyanate-based crosslinking agent, and a urethane acrylate, in which the urethane acrylate contains a residual polymerization catalyst used in producing the urethane acrylate, the residual amount being 70 ppm or more and 200 ppm or less.

[0004] Patent Document 2 (JP 2011-089073 A) describes a pressure-sensitive adhesive sheet obtained by laminating a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive containing a urethane acrylate (D) having a photopolymerization initiator obtained by reacting a (meth)acrylic acid ester monomer (A) having a hydroxyl group, a photopolymerization initiator (B) having a hydroxyl group, and an isocyanate (C) having two or more isocyanate groups, and a (meth)acrylic acid ester polymer (E). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-157420 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-089073 Summary of the Invention [Problem to be solved by the invention]

[0006] A laminate including a pressure-sensitive adhesive layer may be applied to an adherend via the pressure-sensitive adhesive layer. In this case, for example, if the surface of the adherend is coated with a coating having low surface energy, the adhesive strength of the pressure-sensitive adhesive layer may be reduced.

[0007] The present disclosure provides a laminate including a pressure-sensitive adhesive layer with excellent adhesive strength, and an article including the laminate. [Means for solving the problem]

[0008] According to one embodiment of the present disclosure, there is provided a laminate comprising a substrate and a pressure-sensitive adhesive layer containing a cured product of a copolymer and a crosslinking agent, wherein the copolymer is a copolymer of a polymerizable composition containing a (meth)acrylate monomer, a polar monomer, and a mono- or di-functional urethane (meth)acrylate oligomer, and the polymerizable composition contains about 0.005 to about 0.50 parts by mass of the mono- or di-functional urethane (meth)acrylate oligomer per 100 parts by mass of the total amount of the (meth)acrylate monomer and the polar monomer.

[0009] According to another embodiment of the present disclosure, there is provided an article in which the above-described laminate is disposed on an adherend via a pressure-sensitive adhesive layer. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a laminate including a pressure-sensitive adhesive layer with excellent adhesive strength, and an article including the laminate.

[0011] The above description should not be considered as a disclosure of all embodiments of the present invention and all advantages associated with the present invention. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view of a laminate according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, for the purpose of illustrating typical embodiments of the present invention, a more detailed description will be given with reference to the drawings as necessary, but the present invention is not limited to these embodiments.

[0014] In the present disclosure, for example, "on" in "an adhesive layer disposed on a release liner" means that the adhesive layer is disposed directly on top of the release liner, or that the adhesive layer is disposed indirectly on top of the release liner via another layer.

[0015] In the present disclosure, for example, "under" in "a release liner disposed under an adhesive layer" means that the release liner is disposed directly under the adhesive layer, or that the release liner is disposed indirectly under the adhesive layer via another layer.

[0016] In the present disclosure, "transparent" refers to an average transmittance of about 80% or more, and desirably about 85% or more, or about 90% or more, in the visible light region (wavelength 400 nm to 700 nm) measured in accordance with JIS K 7375. There is no particular upper limit to the average transmittance, but it can be, for example, less than about 100%, about 99% or less, or about 98% or less.

[0017] In the present disclosure, the term "semi-transparent" refers to an average transmittance in the visible light region (wavelength 400 nm to 700 nm) measured in accordance with JIS K 7375 of less than approximately 80%, preferably approximately 75% or less, and is intended to not completely conceal the base, etc.

[0018] In the present disclosure, the term "film" also encompasses members called "sheets."

[0019] In this disclosure, "(meth)acrylic" means acrylic or methacrylic, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acryloyl" means acryloyl or methacryloyl.

[0020] A schematic cross-sectional view of a laminate according to one embodiment of the present disclosure is shown in Figure 1. The laminate 100 in Figure 1 includes a substrate 10, a pressure-sensitive adhesive layer 20, and a release liner 30. Here, the release liner shown in Figure 1 is an optional layer, and the laminate of the present disclosure does not necessarily include a release liner.

[0021] The adhesive strength of the laminate of the present disclosure can be evaluated by an adhesive strength test described below. In some embodiments, the laminate of the present disclosure can exhibit an adhesive strength of about 9.5 N / 25 mm or more, about 10.0 N / 25 mm or more, about 10.5 N / 25 mm or more, about 11.0 N / 25 mm or more, about 11.5 N / 25 mm or more, or about 12.0 N / 25 mm or more under room temperature conditions. The upper limit of the adhesive strength can be, for example, about 20.0 N / 25 mm or less, about 19.5 N / 25 mm or less, or about 19.0 N / 25 mm or less. Here, room temperature refers to the temperature in the room where the test is performed, and specifically refers to, for example, about 23°C ± about 5°C, about 23°C ± about 3°C, or about 23°C ± about 1°C.

[0022] In some embodiments, the laminate of the present disclosure can exhibit an adhesive strength of about 9.0 N / 25 mm or more, about 9.5 N / 25 mm or more, about 10.0 N / 25 mm or more, about 10.5 N / 25 mm or more, or about 11.0 N / 25 mm or more in a low-temperature (e.g., about 10° C.) environment. The upper limit of such adhesive strength can be, for example, about 18.0 N / 25 mm or less, about 17.5 N / 25 mm or less, or about 17.0 N / 25 mm or less.

[0023] The laminate of the present disclosure includes a pressure-sensitive adhesive layer containing a copolymer and a cured product of a crosslinking agent. Since the copolymer is a polymer that can be further crosslinked with a crosslinking agent, the copolymer before crosslinking with the crosslinking agent can also be called a "partial polymer."

[0024] The copolymer constituting the pressure-sensitive adhesive layer is a copolymer of a polymerizable composition containing a (meth)acrylate monomer, a polar monomer, and a mono- or di-functional urethane (meth)acrylate oligomer, and this polymerizable composition contains about 0.005 to about 0.50 parts by mass of the mono- or di-functional urethane (meth)acrylate oligomer per 100 parts by mass of the total amount of the (meth)acrylate monomer and the polar monomer. It is believed that the pressure-sensitive adhesive layer of the present disclosure can introduce a urethane moiety into the copolymer by using a mono- or di-functional urethane (meth)acrylate oligomer (sometimes referred to as "oligomer"), thereby improving adhesive strength to an adherend or the like. The present inventors have found that adhesive strength can be improved even when the amount of such oligomer is small.

[0025] The (meth)acrylate monomer and polar monomer contained in the polymerizable composition are not particularly limited. These monomers may typically be monofunctional monomers. The polymerizable composition may optionally contain a polyfunctional (meth)acrylate.

[0026] Examples of monofunctional monomers include monofunctional (meth)acrylate monomers, such as alkyl (meth)acrylates in which the alkyl group has 1 to 20 carbon atoms (sometimes referred to as "C1-20 alkyl (meth)acrylates"), and monofunctional polar monomers, such as unsaturated monomers having a vinyl carbonyl group and a polar group (sometimes referred to as "polar unsaturated monomers"). The monofunctional monomers can be used alone or in combination of two or more.

[0027] An alkyl(meth)acrylate having an alkyl group with 1 to 20 carbon atoms means that, for example, when the alkyl(meth)acrylate is viewed as an ester of acrylic acid and an alkyl alcohol, the alkyl alcohol has 1 to 20 carbon atoms. In other words, when the alkyl(meth)acrylate is an ester of acrylic acid and an alkyl alcohol, the alkyl(meth)acrylate has 1 to 20 carbon atoms. 1 When expressed as R 1 is an alkyl group having 1 to 20 carbon atoms.

[0028] The number of carbon atoms in the alkyl group of the alkyl (meth)acrylate is preferably 4 or more, 6 or more, or 8 or more, and is preferably 18 or less, 16 or less, 14 or less, or 12 or less, from the viewpoint of the adhesive strength of the pressure-sensitive adhesive layer, for example.

[0029] Examples of alkyl(meth)acrylates include methyl(meth)acrylate, ethyl(meth)acrylate, n-propyl(meth)acrylate, isopropyl(meth)acrylate, n-butyl(meth)acrylate, isobutyl(meth)acrylate, sec-butyl(meth)acrylate, tert-butyl(meth)acrylate, n-pentyl(meth)acrylate, n-hexyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, n-heptyl(meth)acrylate, n-octyl(meth)acrylate, isooctyl(meth)acrylate, and n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, n-undecyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, n-pentadecyl (meth)acrylate, n-hexadecyl (meth)acrylate, n-heptadecyl (meth)acrylate, n-octadecyl (meth)acrylate, cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, and isobornyl (meth)acrylate, etc. Among these, 2-ethylhexyl (meth)acrylate is preferred from the viewpoint of adhesive strength, etc.

[0030] The polar unsaturated monomer has a vinyl carbonyl group and a polar group.

[0031] Examples of polar groups include a hydroxyl group, a carboxyl group, a carbamoyl group, an amino group, an epoxy group, and a nitrile group, and among these, a hydroxyl group, a carboxyl group, and an amino group are preferred.

[0032] The vinylcarbonyl group is a group represented by CH═CH—C(═O)—. The vinylcarbonyl group and the polar group may be bonded directly or via a linking group such as an alkylene group.

[0033] Examples of polar unsaturated monomers include hydroxyl group-containing unsaturated monomers such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol (meth)acrylate, and polypropylene glycol (meth)acrylate; carboxyl group-containing unsaturated monomers (sometimes simply referred to as "carboxylic acids") such as acrylic acid, itaconic acid, maleic acid, and fumaric acid; amide group-containing unsaturated monomers such as (meth)acrylamide, diacetone (meth)acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam, and N-vinylformamide; amino group-containing unsaturated monomers such as N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate; epoxy group-containing unsaturated monomers such as glycidyl (meth)acrylate; and cyclic ether-containing unsaturated monomers such as tetrahydrofurfuryl (meth)acrylate. Among these, carboxyl group-containing unsaturated monomers such as acrylic acid are preferred from the viewpoint of adhesive strength, etc. For example, when the surface energy of the adherend surface to which the pressure-sensitive adhesive layer is applied is low, it is preferred to use N-vinylpyrrolidone and / or tetrahydrofurfuryl (meth)acrylate from the viewpoint of improving adhesive strength to such surface.

[0034] The ratio of (meth)acrylate monomers to polar monomers in the monofunctional monomers is preferably about 70% by mass or more, about 85% by mass or more, or about 87% by mass or more, and about 99% by mass or less, or about 98% by mass or less, and the ratio of polar monomers (e.g., polar unsaturated monomers) is preferably about 1% by mass or more, or about 2% by mass or more, and about 30% by mass or less, about 20% by mass or less, about 15% by mass or less, about 13% by mass or less, or about 10% by mass or less, where the total amount of monofunctional monomers is 100% by mass. When the ratio of (meth)acrylate monomers to polar monomers in the monofunctional monomers is within the above ranges, conformability to uneven areas, adhesive strength, holding power, etc. can be improved.

[0035] Examples of the polyfunctional (meth)acrylate, which is an optional component, include 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, and tetramethylolmethane tri(meth)acrylate.

[0036] When a polyfunctional (meth)acrylate is blended in the polymerizable composition, the content of the polyfunctional (meth)acrylate in the monomer components is preferably about 0.05 mmol or more, or about 0.1 mmol or more and about 0.8 mmol or less, per 100 g of the monofunctional monomer. When the content ratio of the polyfunctional (meth)acrylate is within the above range, the composition has excellent conformability to uneven areas, adhesive strength, holding power, etc.

[0037] The mono- or di-functional urethane (meth)acrylate oligomer refers to a mono- or di-functional compound having a plurality of units (units having a urethane bond) derived from a urethane (meth)acrylate monomer and having a (meth)acryloyl group.

[0038] The amount of mono- or difunctional urethane (meth)acrylate oligomer blended relative to 100 parts by mass of the total amount of the (meth)acrylate monomer and polar monomer described above is, from the viewpoints of adhesive strength and suppression of gelation of the pressure-sensitive adhesive, preferably about 0.005 parts by mass or more, about 0.010 parts by mass or more, about 0.020 parts by mass or more, about 0.030 parts by mass or more, about 0.040 parts by mass or more, or about 0.050 parts by mass or more, and preferably about 0.50 parts by mass or less, about 0.45 parts by mass or less, about 0.40 parts by mass or less, about 0.35 parts by mass or less, or about 0.30 parts by mass or less. The oligomer used in the pressure-sensitive adhesive layer of the present disclosure can exhibit excellent adhesive strength despite being used in a small amount compared to the amount used of the monomer component.

[0039] Mono- or di-functional urethane (meth)acrylate oligomers are urethane oligomers, which are reaction products of polyols such as diols and polyisocyanates such as diisocyanates, into which one or two (meth)acryloyl groups have been introduced at either the terminal or side chain. These (meth)acryloyl groups react with the above-mentioned monomer components to form copolymers. The mono- and difunctional urethane (meth)acrylate oligomers may each be one type or a combination of two or more types. The polyols and polyisocyanates constituting such oligomers may each be one type or a combination of two or more types.

[0040] Examples of polyols include polyester polyols, polyether polyols, polycarbonate polyols, and polycaprolactone polyols.

[0041] The polyol may include a low molecular weight diol, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,4-cyclohexanedimethanol, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated bisphenol F, 1,2-cyclopentanediol, and tricyclo[5.2.1.0]diol. 2,6 ]Decanedimethanol is an example.

[0042] Examples of polyisocyanates include aliphatic isocyanates and aromatic isocyanates. Examples of aliphatic isocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, decamethylene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, and 4,4'-methylenebis(cyclohexylisocyanate). Examples of aromatic isocyanates include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, methylene diphenyl 4,4'-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, diphenylmethane-2,2'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 4,4'-diisocyanato-3,3'-dimethylbiphenyl, 1,5-naphthalene diisocyanate, and 2-methyl-1,5-naphthalene diisocyanate.

[0043] The introduction of a (meth)acryloyl group can be achieved, for example, by reacting a hydroxyl group-containing (meth)acrylate with the isocyanato terminal of the urethane oligomer. Examples of hydroxyl group-containing (meth)acrylates include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, dipropylene glycol monoacrylate, and dipropylene glycol monomethacrylate. The hydroxyl group-containing (meth)acrylates can be used alone or in combination of two or more. In this embodiment, it is desirable to use an excess of polyisocyanate relative to the polyol during the synthesis of the urethane oligomer, i.e., to set the molar ratio of NCO groups to OH groups to be greater than 1.

[0044] The introduction of (meth)acryloyl groups can also be achieved by reacting the hydroxyl terminals of the urethane oligomer with an isocyanato group-containing (meth)acrylate. Examples of isocyanato group-containing (meth)acrylates include 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate. In this embodiment, it is desirable to use an excess of polyol relative to polyisocyanate during the synthesis of the urethane oligomer, i.e., to set the molar ratio of NCO groups to OH groups to less than 1.

[0045] Examples of urethane (meth)acrylate oligomers include polyester-based urethane (meth)acrylate oligomers, polycarbonate-based urethane (meth)acrylate oligomers, and polyether-based urethane (meth)acrylate oligomers. Among these, polyether-based urethane (meth)acrylate oligomers are preferred from the viewpoint of adhesive strength, etc. Here, the bifunctional urethane (meth)acrylate oligomers can also be referred to as polyester-based urethane di(meth)acrylate oligomers, polycarbonate-based urethane di(meth)acrylate oligomers, and polyether-based urethane di(meth)acrylate oligomers.

[0046] The weight average molecular weight (Mw) of the mono- or difunctional urethane (meth)acrylate oligomer may be, for example, about 1,000 or more or about 50,000 or less. From the viewpoint of adhesive strength, etc., the weight average molecular weight is preferably about 5,000 or more, about 6,000 or more, about 8,000 or more, or about 10,000 or more, and is preferably about 30,000 or less, about 25,000 or less, about 20,000 or less, about 18,000 or less, or about 15,000 or less. In the present disclosure, "weight average molecular weight" is a value calculated using standard polystyrene standards by gel permeation chromatography.

[0047] The glass transition temperature (Tg) of the mono- or di-functional urethane (meth)acrylate oligomer may be, for example, about 100°C or lower, or about -100°C or higher. From the viewpoint of adhesive strength, etc., the glass transition temperature is preferably about 70°C or lower, about 60°C or lower, about 50°C or lower, about 30°C or lower, about 10°C or lower, or about 0°C or lower, and is preferably about -90°C or higher, about -85°C or higher, about -80°C or higher, or about -75°C or higher. In the present disclosure, the "glass transition temperature" is a value determined in accordance with ASTM E1640-09 using the storage modulus (E') by dynamic mechanical analysis (DMA).

[0048] The copolymer (partial polymer) is preferably prepared using radical polymerization, and can be prepared using known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization, bulk polymerization, etc. Depending on the polymerization method, various auxiliaries such as polymerization initiators, chain transfer agents, emulsifiers, and suspending agents can be used, and solvents (e.g., ethyl acetate) can also be used.

[0049] Examples of the polymerization initiator include organic peroxides such as benzoyl peroxide, lauroyl peroxide, and bis(4-tert-butylcyclohexyl)peroxydicarbonate, and thermal polymerization initiators such as azo-based polymerization initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl 2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(2,4-dimethylvaleronitrile) (AVN). The amount of such initiator used can be about 0.01 parts by weight or more, or about 0.05 parts by weight or more, and about 5 parts by weight or less, about 3 parts by weight or less, about 1 part by weight or less, or about 0.5 parts by weight or less, based on 100 parts by weight of the total of the monomer and oligomer components polymerizable with the polymerization initiator.

[0050] The copolymer can also be obtained by, for example, blending a photopolymerization initiator with the monomer component and oligomer component, and irradiating the mixture with light to photopolymerize the monomer component and oligomer component.

[0051] Examples of the photopolymerization initiator include azo compounds such as azobisisobutyronitrile; benzoins such as benzoin, benzoin methyl ether, benzisoethyl ether, benzoin propyl ether, benzoin isobutyl ether, α-methylbenzoin, and α-phenylbenzoin; anthraquinones such as anthraquinone, methylanthraquinone, and chloroanthraquinone; and onium salts such as p-methoxybenzenediazonium, hexafluorophosphate, diphenyliodonium, and triphenylsulfonium.

[0052] Other examples of photopolymerization initiators include benzyl dialkyl ketals such as 2,2-dimethoxy-1,2-diphenylethan-1-one; α-hydroxyalkylphenones such as 1-hydroxycyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, and 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one; 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, and 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1,2-(dimethylamino)-2- Examples of the oxime include α-aminoalkylphenones such as [(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone; acylphosphine oxides such as 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide and bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide; titanocenes such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium; and oxime esters such as 1,2-octanedione, 1-[4-(phenylthio)-, 2-(O-benzoyloxime)], ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetyloxime).

[0053] The content of the photopolymerization initiator used in preparing the copolymer can be about 0.01 part by mass or more or about 0.05 part by mass or more, and about 1.0 part by mass or less or about 0.5 part by mass or less, relative to 100 parts by mass of the total of the monomer components and oligomer components polymerizable with the photopolymerization initiator.

[0054] The light irradiation can be, for example, irradiation with ultraviolet rays, electron beams, X-rays, or other radiation. For example, the irradiation intensity is about 0.05 mW / cm for a composition containing a photopolymerization initiator, a monomer component, and an oligomer component. 2 or more than or about 0.1 mW / cm 2 More than about 10mW / cm 2 Less than or equal to about 5mW / cm 2 Thereafter, the copolymer can be obtained by irradiating with radiation (for example, ultraviolet light) for an irradiation time of about 5 seconds or more, or about 10 seconds or more, and about 300 seconds or less, or about 240 seconds or less.

[0055] Chain transfer agents are substances that control free radical polymerization and are generally known in the art. Examples of chain transfer agents include halogenated hydrocarbons such as carbon tetrabromide, and sulfur compounds such as lauryl mercaptan, butyl mercaptan, ethanethiol, isooctyl thioglycolate (IOTG), 2-ethylhexyl thioglycolate, 2-ethylhexyl mercaptopropionate, 2-mercaptoimidazole, and 2-mercaptoethyl ether. Chain transfer agents can be used alone or in combination.

[0056] The content of the chain transfer agent can be set depending on the desired molecular weight and the type of the chain transfer agent, and can be, for example, about 0.01 part by mass or more or about 0.05 part by mass or more, and about 1.0 part by mass or less or about 0.5 part by mass or less, relative to 100 parts by mass in total of the monomer component and the oligomer component on which the chain transfer agent acts.

[0057] The pressure-sensitive adhesive layer of the present disclosure can be prepared using a pressure-sensitive adhesive composition containing a copolymer (partial polymer) and a crosslinking agent. By using a composition containing a crosslinking agent, the pressure-sensitive adhesive layer containing a cured product of the copolymer and the crosslinking agent can have a crosslinked structure. There are no particular limitations on the crosslinking agent, and for example, a thermal crosslinking agent and a radiation crosslinking agent (e.g., an ultraviolet crosslinking agent) can be used. The thermal crosslinking agent and the radiation crosslinking agent can be used in combination. Each of these crosslinking agents can be used alone or in combination of two or more.

[0058] Examples of thermal crosslinking agents include isocyanate compounds such as hexamethylene diisocyanate and toluidine diisocyanate; epoxy compounds such as 1,3-bis(N,N-diglycidylaminomethyl)toluene and N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane; metal chelate compounds such as trisethylacetoacetate aluminum and ethylacetoacetate aluminum diisopropylate; and imine compounds such as N,N'-toluene-2,4-bis(1-aziridinecarboxamide)triethylenemelamine and hexamethylenediethyleneurea. Other examples that can be used include bisamide-based crosslinking agents (e.g., [3-(2-methylaziridine-1-carbonyl)phenyl]-(2-methylaziridin-1-yl)methanone), aziridine-based crosslinking agents (e.g., Chemitite PZ33 manufactured by Nippon Shokubai and NeoCryl CX-100 manufactured by Avecia), carbodiimide-based crosslinking agents (e.g., Carbodilite V-03, V-05, and V-07 manufactured by Nisshinbo), and epoxy-based crosslinking agents (e.g., E-AX, E-5XM, and E5C manufactured by Soken Chemical & Engineering).

[0059] Examples of ultraviolet crosslinking agents, which are a type of radiation crosslinking agent, include benzophenone compounds such as benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, and 3,3'-dimethyl-4-methoxybenzophenone, and (meth)acrylic polymers having an ultraviolet crosslinkable moiety.

[0060] A (meth)acrylic polymer having an ultraviolet-crosslinkable moiety can act as an additive to make a composition containing a copolymer (partial polymer) ultraviolet-crosslinkable. A composition containing such a (meth)acrylic polymer having an ultraviolet-crosslinkable moiety has good compatibility between the components, making it less susceptible to microscopic or macroscopic phase separation, thereby improving performance such as crosslinkability and transparency. The ultraviolet-crosslinkable moiety may be a polymerizable functional group such as a (meth)acrylic group or an epoxy group, and may have a structure capable of abstracting hydrogen radicals upon ultraviolet irradiation.

[0061] In a representative embodiment, a (meth)acrylic polymer having a UV-crosslinkable moiety has at least one structure capable of abstracting hydrogen radicals upon UV irradiation. This structure is excited by UV irradiation and abstracts hydrogen radicals from other portions of the copolymer and the (meth)acrylic polymer having a UV-crosslinkable moiety in the pressure-sensitive adhesive composition, or from other molecules of the copolymer and the (meth)acrylic polymer having a UV-crosslinkable moiety. As a result, radicals are generated on the molecules of the copolymer and the (meth)acrylic polymer having a UV-crosslinkable moiety. Various reactions occur in the system, including the formation of crosslinked structures through bonding between the generated radicals, the generation of peroxide radicals through reaction with oxygen molecules and the formation of crosslinked structures via the generated peroxide radicals, and the abstraction of other hydrogen radicals by the generated radicals. Ultimately, the pressure-sensitive adhesive composition of the present disclosure can be crosslinked to obtain a pressure-sensitive adhesive. Having a structure capable of abstracting hydrogen radicals upon UV irradiation is advantageous because it does not require an additional photoinitiator.

[0062] Examples of structures capable of abstracting hydrogen radicals upon irradiation with ultraviolet light include a benzophenone group, a benzyl group, an o-benzoylbenzoate group, a thioxanthone group, a 3-ketocoumarin group, a 2-ethylanthraquinone group, a camphorquinone group, etc. Among these, it is preferable to use a benzophenone group from the viewpoints of transparency, reactivity, etc.

[0063] The (meth)acrylic polymer having a structure capable of abstracting hydrogen radicals upon irradiation with ultraviolet light may be a copolymer of at least one alkyl (meth)acrylate selected from alkyl (meth)acrylates having a linear, branched, or cyclic alkyl group having 1 to 22 carbon atoms and a (meth)acrylate having a benzophenone group, a benzyl group, an o-benzoylbenzoic acid ester group, a thioxanthone group, a 3-ketocoumarin group, a 2-ethylanthraquinone group, a camphorquinone group, or the like.

[0064] For example, examples of (meth)acrylates having a benzophenone group that can be used include 4-acryloyloxybenzophenone, 4-acryloyloxyethoxybenzophenone, 4-acryloyloxy-4'-methoxybenzophenone, 4-acryloyloxyethoxy-4'-methoxybenzophenone, 4-acryloyloxy-4'-bromobenzophenone, 4-acryloyloxyethoxy-4'-bromobenzophenone, 4-methacryloyloxybenzophenone, 4-methacryloyloxyethoxybenzophenone, 4-methacryloyloxy-4'-methoxybenzophenone, 4-methacryloyloxyethoxy-4'-methoxybenzophenone, 4-methacryloyloxy-4'-bromobenzophenone, 4-methacryloyloxyethoxy-4'-bromobenzophenone, and mixtures thereof. Among these, those in which an alkylene group, for example, an alkylene group having 1 to 6 carbon atoms, is interposed between the (meth)acryloyl group and the benzophenone group are advantageous because they have an excellent balance between stability and reactivity, and examples of such (meth)acrylates include 4-acryloyloxyethoxybenzophenone, 4-acryloyloxyethoxy-4'-methoxybenzophenone, 4-acryloyloxyethoxy-4'-bromobenzophenone, 4-methacryloyloxyethoxybenzophenone, 4-methacryloyloxyethoxy-4'-methoxybenzophenone, and 4-methacryloyloxyethoxy-4'-bromobenzophenone.

[0065] Examples of alkyl(meth)acrylates having a linear, branched, or cyclic alkyl group having 1 to 22 carbon atoms include methyl(meth)acrylate, ethyl(meth)acrylate, n-butyl(meth)acrylate, hexyl(meth)acrylate, n-octyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isobutyl(meth)acrylate, tert-butyl(meth)acrylate, cyclohexyl(meth)acrylate, isobornyl(meth)acrylate, and dicyclopentanyl(meth)acrylate.

[0066] In some embodiments, the molar number of the structure capable of abstracting hydrogen radicals upon UV irradiation, for example, the benzophenone group, can be about 0.3 μmol / g or more, about 5 μmol / g or more, or about 10 μmol / g or more, based on the total mass of the copolymer and the (meth)acrylic polymer having a UV-crosslinkable moiety in the composition, and can be about 320 μmol / g or less, about 250 μmol / g or less, or about 150 μmol / g or less. By setting the amount of the structure capable of abstracting hydrogen radicals upon UV irradiation within such a range, it is possible to control the density of the crosslinked structure formed by UV irradiation and adjust performance such as adhesiveness.

[0067] The (meth)acrylic polymer having an ultraviolet crosslinkable site may have one or more polymerized units derived from other monomers than those mentioned above. Examples of such other monomers include olefins such as ethylene, butadiene, isoprene, and isobutylene; vinyl monomers such as vinyl acetate, vinyl propionate, and styrene; 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, 1-glycerol (meth)acrylate, 2-hydroxyethyl (meth)acrylamide, N-hydroxypropyl (meth)acrylamide, vinyl alcohol, and allyl alcohol. hydroxyl group-containing monomers such as hydroxyl group-containing monomers; carboxyl group-containing monomers such as (meth)acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid, or anhydrides thereof (e.g., maleic anhydride); amide group-containing monomers such as N-vinylcaprolactam, N-vinylpyrrolidone, (meth)acrylamide, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, and N-octyl(meth)acrylamide; and amino group-containing monomers such as N,N-dimethylaminoethyl(meth)acrylate, N,N-diethylaminoethyl(meth)acrylate, and N,N-dimethylaminoethyl(meth)acrylamide.

[0068] The (meth)acrylic polymer having an ultraviolet crosslinkable moiety can be produced by polymerizing the above-mentioned monomer in the presence of a polymerization initiator. As the polymerization method, a general radical polymerization method such as solution polymerization, emulsion polymerization, suspension polymerization, or bulk polymerization can be used.

[0069] It is preferable to use radical polymerization using a thermal polymerization initiator so that the ultraviolet crosslinkable portion does not react. Examples of such a thermal polymerization initiator include organic peroxides such as benzoyl peroxide, t-butyl perbenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, di(2-ethoxyethyl)peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, lauroyl peroxide, (3,5,5-trimethylhexanoyl)peroxide, dipropionyl peroxide, and diacetyl peroxide, and 2,2'-azobisisobutyronitrile. Examples of azo compounds include 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2-hydroxymethylpropionitrile), and 2,2'-azobis[2-(2-imidazolin-2-yl)propane].

[0070] The weight average molecular weight of the (meth)acrylic polymer having an ultraviolet crosslinkable moiety is not particularly limited, but can be, for example, about 10,000 or more, about 50,000 or more, or about 100,000 or more, and can be about 1,000,000 or less, about 800,000 or less, or about 600,000 or less.

[0071] The amount of crosslinking agent in the pressure-sensitive adhesive composition for preparing the pressure-sensitive adhesive layer can be, for example, approximately 0.05% by mass or more, approximately 0.1% by mass or more, approximately 0.5% by mass or more, or approximately 1.0% by mass or more, calculated as solid content, and can be approximately 10% by mass or less, approximately 5.0% by mass or less, or approximately 1.0% by mass or less.

[0072] The PSA composition may optionally contain other components, either singly or in combination, as long as they do not adversely affect the effects of the present disclosure. Examples of other components include resins other than the copolymers described above (e.g., thermoplastic resins), fillers, conductive agents, thermal conductivity imparting agents, antioxidants, UV absorbers, light stabilizers, heat stabilizers, dispersants, plasticizers, lubricants, surfactants, leveling agents, silane coupling agents, catalysts, pigments, and dyes.

[0073] The pressure-sensitive adhesive layer of the present disclosure can be obtained, for example, by applying a pressure-sensitive adhesive composition containing a copolymer (partial polymer) and a crosslinking agent to a substrate or release liner described below, followed by a heat treatment and / or radiation (e.g., ultraviolet) irradiation treatment.

[0074] The heat treatment can be carried out using, for example, a heater such as an infrared heater, hot air, an oven, or the like. The heat treatment can be carried out batchwise or continuously using a belt conveyor or the like, but from the viewpoint of productivity, it is preferable to carry out the heat treatment continuously. The heating temperature (set temperature) can be, for example, about 70°C or higher, about 80°C or higher, or about 90°C or higher. There is no particular restriction on the upper limit of the heating temperature, and it can be, for example, about 160°C or lower, about 140°C or lower, or about 120°C or lower.

[0075] Ultraviolet irradiation, which is a type of radiation irradiation, can be carried out using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an electrodeless lamp, or a UV-LED as a light source. Ultraviolet irradiation can be carried out in batches or continuously using a belt conveyor or the like, but from the viewpoint of productivity, it is preferable to carry out the irradiation continuously. The irradiation dose of ultraviolet light (UV-C) is, for example, about 1 mJ / cm. 2 Above, about 50mJ / cm 2 or more, or about 100 mJ / cm 2 There is no particular upper limit to the amount of ultraviolet light irradiation, but for example, it can be about 500 mJ / cm 2 or more. 2 Less than or equal to about 450 mJ / cm 2It can be as follows:

[0076] The thickness of the pressure-sensitive adhesive layer of the present disclosure may be appropriately set in consideration of the required adhesive strength, etc. Such a thickness may be, for example, about 10 micrometers or more, about 20 micrometers or more, or about 30 micrometers or more, and about 300 micrometers or less, about 200 micrometers or less, or about 100 micrometers or less.

[0077] The laminate of the present disclosure includes a substrate.

[0078] The material for the substrate is not particularly limited, and examples thereof include (meth)acrylic resins including polymethyl methacrylate (PMMA) and (meth)acrylic copolymers, resins having urethane bonds (e.g., polyurethanes), fluororesins such as ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), and methyl methacrylate-vinylidene fluoride copolymer (PMMA / PVDF), silicone resins, polyolefins such as polyvinyl chloride (PVC), polycarbonate (PC), polyethylene (PE), and polypropylene (PP), polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyamides such as nylon, ethylene / acrylic acid copolymer (EAA) and its ionomers, and copolymers such as ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer (EVOH), which can be used alone or in blends of two or more. Here, in the present disclosure, the term "resin having a urethane bond" refers to a urethane resin, and can also include, for example, a resin prepared using at least one selected from a urethane (meth)acrylate and a urethane (meth)acrylate oligomer, and the urethane resin can also include a (meth)acrylic urethane resin.

[0079] The substrate may have a multilayer structure. For example, the substrate may be a laminate of films formed from the above resins, or a multilayer coating of the above resins. The substrate may have a three-dimensional uneven shape such as an embossed pattern on the entire surface or a part of the surface.

[0080] For example, the substrate can be formed by coating the adhesive layer with a resin composition directly or via an adhesive layer, decorative layer, or the like. The coating of the substrate can be carried out before or after applying the laminate to an adherend, which will be described later. Alternatively, the resin composition can be coated on a release liner to form a substrate film, and the film can be laminated on the adhesive layer. The substrate film can be formed, for example, by coating a resin material, such as a curable (meth)acrylic resin composition or a reactive polyurethane composition, onto a release liner or the like by knife coating, bar coating, blade coating, doctor coating, roll coating, cast coating, or the like, and then, if necessary, by radiation curing or heat curing.

[0081] The substrate may be a film formed in advance by extrusion or stretching. Such a film can be laminated to the pressure-sensitive adhesive layer. By using a film with high flatness, the article (structure) can be given an appearance with even higher surface flatness. The substrate can also be formed by multilayer extrusion with other layers. Examples of other layers that can be used include (meth)acrylic films. Examples of (meth)acrylic films include films of resins containing polymethyl methacrylate (PMMA), polybutyl acrylate, (meth)acrylic copolymers, ethylene / acrylic copolymers, and ethylene vinyl acetate / acrylic copolymers. (Meth)acrylic films have excellent transparency and / or scratch resistance, are resistant to heat and / or light, and are resistant to fading and / or gloss changes. In addition, they have excellent moldability without the use of plasticizers, and because they do not require plasticizers, they also have excellent contamination resistance. Among these, those containing PMMA as the main component are preferred. For example, if a (meth)acrylic resin having excellent scratch resistance is used as the other layer and a fluororesin such as ETFE, PVDF, or PMMA / PVDF having excellent chemical resistance is used as the substrate, the substrate formed can have the properties of both layers.

[0082] The substrate of the present disclosure may contain optional components to the extent that they do not impair performance (e.g., protective performance) appropriate for the application. Examples of optional components include fillers, antioxidants, UV absorbers, light stabilizers, heat stabilizers, hard coating materials, glossing agents, dispersants, plasticizers, flow improvers, surfactants, leveling agents, silane coupling agents, catalysts, pigments, and dyes. In particular, the use of UV absorbers such as benzotriazole, Tinuvin™ 400 (manufactured by BASF), and hindered amine light stabilizers (HALS) such as Tinuvin™ 292 (manufactured by BASF) can effectively prevent discoloration, fading, and deterioration of the underlying adhesive layer. The hard coating material may be contained in the substrate or may be separately coated on the substrate and applied as a hard coating layer. The optional components may be used alone or in combination of two or more.

[0083] The substrate may be partially translucent or opaque, but when the laminate includes a decorative layer or the like, it is preferable that the substrate is transparent from the viewpoint of visibility of such a layer.

[0084] The thickness of the substrate can vary, but can be, for example, about 1 micrometer or more, about 5 micrometers or more, about 10 micrometers or more, about 30 micrometers or more, or about 50 micrometers or more, and can be about 200 micrometers or less, about 150 micrometers or less, about 100 micrometers or less, or about 90 micrometers or less.

[0085] In some embodiments, the laminate of the present disclosure optionally includes an additional layer. Examples of such additional layers include at least one selected from the group consisting of a decorative layer (e.g., a color layer, a pattern layer, or a relief layer), a glitter layer, a bonding layer, an intermediate film layer, and a release liner. The additional layer can be applied to the entire surface or a portion of the laminate. The additional layer may have a three-dimensional shape, such as an embossed pattern, on its surface. A laminate including a layer that can exhibit decorative properties (e.g., a decorative layer) can also be referred to as a "decorative laminate." When the laminate also exhibits protective properties, such as the ability to prevent chipping by pebbles, it can also be referred to as a "protective laminate."

[0086] Examples of decorative layers include, but are not limited to, color layers that exhibit paint colors, such as light colors such as white and yellow, and dark colors such as red, brown, green, blue, gray, and black; pattern layers that impart patterns such as wood grain, stone grain, geometric patterns, and leather patterns, logos, and designs to articles; relief (embossed pattern) layers that have an uneven surface; and combinations of these.

[0087] The decorative layer is not limited to the following, but can be applied to the entire surface or part of the layers constituting the laminate, such as the substrate and / or the adhesive layer, directly or via an adhesive layer or the like.

[0088] Materials for the color layer are not limited to the following, but include, for example, inorganic pigments such as carbon black, yellow lead, yellow iron oxide, red iron oxide, and red iron oxide; phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; organic pigments such as azo lake pigments, indigo pigments, perinone pigments, perylene pigments, quinophthalone pigments, dioxazine pigments, and quinacridone pigments such as quinacridone red; and other pigments dispersed in a binder resin such as a (meth)acrylic resin or a resin having a urethane bond.

[0089] The color layer can be formed using such materials by a coating method such as gravure coating, roll coating, die coating, bar coating, or knife coating.

[0090] The pattern layer is not limited to the following, but may be one in which a pattern such as a design, logo, or picture is applied directly to the substrate and / or pressure-sensitive adhesive layer using a printing method such as gravure direct printing, gravure offset printing, inkjet printing, laser printing, or screen printing, or may alternatively be a film or sheet having a pattern, logo, or picture formed by coating such as gravure coating, roll coating, die coating, bar coating, or knife coating, punching, etching, etc. The material for the pattern layer may be, for example, the same material as that used for the color layer.

[0091] The relief layer can be a thermoplastic resin film having a textured surface formed by a conventional method such as embossing, scratching, laser processing, dry etching, or hot pressing. The relief layer can also be formed by applying a thermosetting or radiation-curing resin such as a curable (meth)acrylic resin to a release liner having a textured surface, curing it by heating or irradiating it with radiation, and then removing the release liner.

[0092] The thermoplastic resin, thermosetting resin, and radiation-curable resin used in the relief layer are not particularly limited, and examples thereof include fluorine-based resins, polyester-based resins such as PET and PEN, (meth)acrylic resins, polyolefin-based resins such as polyethylene and polypropylene, thermoplastic elastomers, polycarbonate, polyamide, ABS resin, acrylonitrile-styrene resin, polystyrene, vinyl chloride, resins having a urethane bond, etc. The relief layer may contain at least one of the pigments used in the color layer.

[0093] The decorative layer of the present disclosure may contain optional components, such as fillers, reinforcing agents, antioxidants, UV absorbers, light stabilizers, heat stabilizers, dispersants, plasticizers, flow improvers, surfactants, leveling agents, silane coupling agents, and catalysts, within the scope of not adversely affecting the effects of the present disclosure.

[0094] The thickness of the decorative layer is not particularly limited and may be adjusted appropriately depending on the required decorativeness, etc. The thickness may be, for example, about 1 micrometer or more, about 3 micrometers or more, or about 5 micrometers or more, and about 50 micrometers or less, about 40 micrometers or less, or about 30 micrometers or less.

[0095] The lustrous layer may be, but is not limited to, a layer comprising a metal selected from aluminum, nickel, gold, silver, copper, platinum, chromium, iron, tin, indium, titanium, lead, zinc, germanium, etc., or an alloy or compound thereof, formed on the entire surface or part of a layer constituting the laminate, for example, the substrate and / or the pressure-sensitive adhesive layer, by vacuum deposition, sputtering, ion plating, plating, etc. The thickness of the lustrous layer can be appropriately set depending on the required decorativeness, etc.

[0096] The laminate of the present disclosure can use a bonding layer (sometimes referred to as a "primer layer") to bond additional layers in the laminate. Commonly used adhesives such as (meth)acrylic, polyolefin, polyurethane, polyester, and rubber adhesives, including solvent-based, emulsion-based, pressure-sensitive, heat-sensitive, heat-curable, and UV-curable adhesives, can be used as the bonding layer. The bonding layer can be applied by known coating methods.

[0097] The laminate of the present disclosure may include an intermediate film layer, which may be, for example, a resin film made of a resin having a urethane bond, a polyolefin such as polyvinyl chloride, polyethylene, or polypropylene, a polyester such as polyethylene terephthalate or polybutylene terephthalate, a (meth)acrylic polymer, or a fluorine-based polymer.

[0098] The thickness of the intermediate film layer can be about 5 micrometers or more, about 10 micrometers or more, or about 15 micrometers or more, and about 200 micrometers or less, about 100 micrometers or less, or about 50 micrometers or less.

[0099] The laminate of the present disclosure typically has a release liner applied to the adhesive layer. Examples of release liners include paper; plastic materials such as polyethylene, polypropylene, polyester (e.g., PET), and cellulose acetate; and paper coated with such plastic materials. These liners may have a surface that has been treated with a release agent such as silicone.

[0100] The thickness of the release liner can generally be about 5 micrometers or more, about 15 micrometers or more, or about 25 micrometers or more, and can be about 500 micrometers or less, about 300 micrometers or less, about 100 micrometers or less, or about 50 micrometers or less.

[0101] The laminate of the present disclosure may be, for example, a sheet product, a rolled product, or a three-dimensional shape.

[0102] The following manufacturing method will be described as an example, but the manufacturing method of the laminate of the present disclosure is not limited to this.

[0103] For example, in the case of a laminate having a configuration in which a release liner, a pressure-sensitive adhesive layer, a decorative layer (e.g., a color layer), and a substrate are sequentially formed, a pigment-containing color layer composition is coated on the substrate, and a drying process and a curing process are performed as necessary to form the color layer. Subsequently, a pressure-sensitive adhesive composition is coated on the color layer, and a drying process and a curing process are performed as necessary to form the pressure-sensitive adhesive layer, and then a release liner is attached to the pressure-sensitive adhesive layer to form the laminate.

[0104] In some embodiments, the laminate of the present disclosure described above is placed on an adherend via a pressure-sensitive adhesive layer to provide an article comprising the laminate.

[0105] There are no particular limitations on the material of the adherend to which the laminate can be applied. Examples of such materials include resin materials (e.g., polyolefin resin, polyester resin, (meth)acrylic resin, polycarbonate resin, resin with urethane bonds, acrylonitrile-butadiene-styrene copolymer), inorganic materials (e.g., glass, ceramic, concrete, gypsum, calcium silicate, natural stone, asphalt), rubber materials, fabric materials (e.g., woven fabric, knitted fabric, nonwoven fabric), metal or metal alloy materials (e.g., iron, aluminum, stainless steel), and wood materials including paper. An optional layer such as an antifouling layer (e.g., an antifouling coating) may be applied to the surface of the adherend. From the viewpoint of adhesive strength, the surface of the adherend preferably contains a resin material, and more preferably contains a (meth)acrylic resin and / or a resin with urethane bonds. The laminate of the present disclosure can be suitably adhered to adherends with urethane coatings, for example, and can be used for urethane coatings.

[0106] The pressure-sensitive adhesive layer constituting the laminate of the present disclosure has excellent adhesive strength, making it suitable for application to low surface energy surfaces such as antifouling layers. Therefore, the laminate of the present disclosure can be suitably used for adherends with low surface energy, more specifically, for adherends with a surface energy of about 36 dynes / cm or less. For example, urethane-coated surfaces that exhibit antifouling properties have such low surface energy surfaces. Specific examples of the surface energy of such surfaces can be about 36 dynes / cm or less, about 35 dynes / cm or less, about 34 dynes / cm or less, or about 33 dynes / cm or less. The lower limit of such surface energy can be, for example, about 22 dynes / cm or more, about 23 dynes / cm or more, or about 24 dynes / cm or more. The surface energy of the adherend surface can be tested according to JIS K 6768:1999, Plastic Film and Sheet Wet Tension Test Method. Specifically, several drops of the test mixture are placed on the test piece, and the test mixture is immediately spread using a wire bar, cotton swab, or brush. After two seconds, the surface energy (wet tension) can be determined from the state of the center of the liquid film. If the applied liquid film remains intact and in its original state, it is judged as "wet." If it breaks, it is judged as "not wet." The surface tension (dyne / cm (microN / cm)) of the test mixture used when the test piece is judged as "wet" can be evaluated as the surface energy (wet tension) of the test piece. For example, a series of test mixtures for wetting tension testing manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. can be used as the test mixture.

[0107] The shape or configuration of the adherend is not particularly limited, and may be, for example, a planar shape (e.g., a film or plate shape), a curved shape, an irregular shape, or a three-dimensional shape, and may be a single-layer structure, a laminated structure, or a composite structure in which multiple components of different shapes or materials are combined.

[0108] The laminate of the present disclosure can be used in a variety of applications. Examples of such applications include signs (e.g., internally illuminated signs and externally illuminated signs); signs (e.g., internally illuminated signs and externally illuminated signs); various interior or exterior parts, such as interior or exterior parts for vehicles such as automobiles, trains, aircraft, and ships (e.g., roof members, pillar members, door trim members, instrument panel members, front members such as hoods, bumper members, fender members, side sill members, and interior panel members); and interior or exterior parts for buildings (e.g., roof members such as window glass, doors, sashes, and roofing members such as roof tiles, exterior wall members, wallpaper, etc.); electrical appliances such as personal computers, smartphones, mobile phones, refrigerators, and air conditioners; stationery; furniture; desks; and various containers such as cans. The pressure-sensitive adhesive layer constituting the laminate of the present disclosure also has excellent durability, such as weather resistance, and can therefore be suitably used for exterior applications, more specifically, for the exterior of vehicles (e.g., automobiles).

[0109] The method for applying the laminate of the present disclosure to the adherend (support member) that constitutes the article is not particularly limited, and any known method can be used as appropriate. Examples of such methods include hand lamination, injection molding methods such as insert injection molding, in-mold molding, over-mold molding, two-color injection molding, core-back injection molding, and sandwich injection molding, lamination, and three-dimensional thermal orientation molding (TOM). [Example]

[0110] The following examples illustrate specific embodiments of the present disclosure, but the present invention is not limited thereto. All parts and percentages are by weight unless otherwise specified. Numerical values ​​inherently contain errors resulting from measurement principles and measuring devices. Numerical values ​​are expressed to the nearest significant digit with ordinary rounding applied.

[0111] The various materials used are shown in Table 1. In the table, "Mw" and "Tg" mean "weight average molecular weight" and "glass transition temperature," respectively.

[0112] [Table 1]

[0113] Preparation of adhesive composition The polymerizable compositions obtained by mixing the monomer and oligomer components, chain transfer agent, polymerization initiator, and solvent shown in Tables 2 and 3 in the proportions shown in Tables 2 and 3 were placed in 225 mL glass bottles, bubbled with nitrogen gas, and then sealed with caps. The glass bottles were shaken in a 60°C water bath for 24 hours to prepare copolymer-containing solutions. Each pressure-sensitive adhesive composition was prepared by adding and mixing a crosslinker (solids content: 10%) to the copolymer-containing solution so that 1.25 parts by weight of the crosslinker was contained per 100 parts by weight of the resulting solution (solids content: 40%). The numerical values ​​for each component in Tables 2 and 3 are based on parts by weight, and each component was blended so that the total amount of the acrylate monomer and polar monomer was 100 parts by weight.

[0114] Preparation of laminate (adhesive tape) The adhesive composition was applied to a release liner, which was then placed in an oven at 65°C for 3 minutes, and then in an oven at 95°C for 3 minutes to crosslink and dry. The crosslinked and dried product was laminated with a substrate to prepare laminates (adhesive tapes) having the configuration shown in Figure 1.

[0115] Evaluation Test The peel adhesive strength of the pressure-sensitive adhesive tape to a coated panel was evaluated using the following method. The results are shown in Tables 2 and 3. The coated panel used here was a urethane-coated panel (Tmac9000, manufactured by ACT Test Panel Technologies, Hillsdale, Michigan, USA) with a surface energy of approximately 24 dynes / cm. The pressure-sensitive adhesive compositions of Comparative Examples 3 to 6 gelled and could not be subjected to the following tests, and are therefore indicated as "-" in Tables 2 and 3.

[0116] Room temperature adhesion test The 180-degree peel adhesive strength was measured at room temperature (23°C) in accordance with ASTM D 1000. Specifically, the pressure-sensitive adhesive tape was cut into 0.5-inch wide pieces to prepare test samples, and the 180-degree peel adhesive strength of the test samples was measured on the painted surface of a painted panel in a room temperature environment in accordance with ASTM D 1000.

[0117] Low temperature adhesion test A test sample of the pressure-sensitive adhesive tape prepared in the same manner as in the above test was applied to the painted surface of a painted panel and left to stand for 20 minutes in an environment of 23°C. The test sample was then exposed to a low-temperature environment of 10°C for 10 minutes, and the 90-degree peel adhesive strength of the test sample was measured in the low-temperature environment of 10°C.

[0118] [Table 2]

[0119] [Table 3]

[0120] It will be apparent to those skilled in the art that the above-described embodiments and examples can be modified in various ways without departing from the basic principles of the present invention, and that various improvements and modifications of the present invention can be made without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0121] 10 Base material 20 adhesive layer 30 Release Liner 100 laminate

[0122] Some embodiments of the present disclosure are described in [Item 1] to [Item 7] below. [Item 1] a pressure-sensitive adhesive layer including a copolymer and a cured product of a crosslinking agent, and a substrate; the copolymer is a copolymer of a polymerizable composition containing a (meth)acrylate monomer, a polar monomer, and a mono- or di-functional urethane (meth)acrylate oligomer, and the polymerizable composition contains about 0.005 to about 0.50 parts by mass of the mono- or di-functional urethane (meth)acrylate oligomer per 100 parts by mass of the total amount of the (meth)acrylate monomer and the polar monomer; Laminate. [Item 2] Item 2. The laminate according to item 1, wherein the mono- or di-functional urethane (meth)acrylate oligomer is a polyether-based urethane (meth)acrylate oligomer. [Item 3] 3. The laminate according to item 1 or 2, wherein the weight average molecular weight of the mono- or di-functional urethane (meth)acrylate oligomer is about 5,000 to about 30,000. [Item 4] 4. The laminate according to any one of items 1 to 3, wherein the glass transition temperature of the mono- or di-functional urethane (meth)acrylate oligomer is about 70° C. or lower. [Item 5] 5. The laminate according to any one of items 1 to 4, which is for use on an adherend having a surface energy of about 36 dynes / cm or less. [Item 6] 6. The laminate according to any one of items 1 to 5, which is for exterior use. [Item 7] 7. An article, in which the laminate according to any one of items 1 to 6 is disposed on an adherend via the pressure-sensitive adhesive layer.

Claims

1. a pressure-sensitive adhesive layer including a copolymer and a cured product of a crosslinking agent, and a substrate; the copolymer is a copolymer of a polymerizable composition containing a (meth)acrylate monomer, a polar monomer, and a mono- or di-functional urethane (meth)acrylate oligomer, and the polymerizable composition contains 0.005 to 0.50 parts by mass of the mono- or di-functional urethane (meth)acrylate oligomer per 100 parts by mass of the total amount of the (meth)acrylate monomer and the polar monomer; Laminate.

2. The laminate according to claim 1 , wherein the mono- or di-functional urethane (meth)acrylate oligomer is a polyether-based urethane (meth)acrylate oligomer.

3. 3. The laminate according to claim 1, wherein the weight average molecular weight of the mono- or di-functional urethane (meth)acrylate oligomer is 5,000 to 30,000.

4. The laminate according to claim 1 or 2, wherein the mono- or di-functional urethane (meth)acrylate oligomer has a glass transition temperature of 70°C or lower.

5. 3. The laminate according to claim 1, which is for use on an adherend having a surface energy of 36 dynes / cm or less.

6. The laminate according to claim 1 or 2, which is for exterior use.

7. An article, comprising the laminate according to claim 1 or 2, disposed on an adherend via the pressure-sensitive adhesive layer.

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