Ultraviolet-curable composition for printing and method for producing laminate

Abstract

The purpose of the present invention is to provide an ultraviolet-curable composition for printing which has excellent printability and re-peelability. Another purpose of the present invention is to provide a method for producing a laminate which uses said ultraviolet-curable composition for printing. The present invention is an ultraviolet-curable composition for printing comprising a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, a photopolymerization initiator, and a thermoplastic resin. A cured product which has a thickness of 100 μm and which is obtained by coating the ultraviolet-curable composition for printing onto a substrate and performing irradiation with light of a wavelength of 280-480 nm, an irradiance of 60 mW / cm2, and an irradiation amount of 900 mJ / cm2 in an atmospheric environment without sealing the upper surface of the coating has a shear storage modulus of not less than 5.0×104 Pa at 150°C in a dynamic viscoelasticity measurement performed with a frequency of 1 Hz.

Description

UV-curable composition for printing and method for producing laminate

[0001] The present invention relates to an ultraviolet-curable composition for printing, and also to a method for producing a laminate using the ultraviolet-curable composition for printing.

[0002] Adhesives are used to bond electronic components inside electronic devices such as smartphones and PCs. A typical adhesive bonding method involves first preparing an adhesive sheet with separators on both sides of the adhesive, and then cutting the adhesive sheet into a desired shape. One separator is then peeled from the cut adhesive sheet, and one side of the exposed adhesive is bonded to a first adherend. The other separator is then peeled off, and the other side of the exposed adhesive is bonded to a second adherend. This method generates waste because a portion of the adhesive sheet is discarded after cutting.

[0003] In response to this, a method has been studied in which an adhesive is printed in a desired shape and then attached to an adherend, without producing an adhesive sheet, which can reduce waste generation.

[0004] For example, Patent Document 1 discloses an invention for providing a radiation-curable pressure-sensitive adhesive composition that allows for fine patterning and exhibits high adhesion to various adherends such as metals and plastics. Patent Document 1 describes a radiation-curable pressure-sensitive adhesive composition that contains 10 to 70% by weight of an aromatic ring-free ethylenically unsaturated monomer, 1 to 10% by weight of a photopolymerization initiator, and 10 to 55% by weight of a crosslinking agent.

[0005] Furthermore, Patent Document 2 discloses an invention for providing a photocurable adhesive composition that, even when irradiated with light in the presence of oxygen, provides a laminate having adhesive strength equivalent to that in the absence of oxygen. Patent Document 2 describes a photocurable adhesive composition containing (A) a (meth)acrylate oligomer, (B) a monofunctional (meth)acrylate monomer, (C) a di- to tetra-functional (meth)acrylate monomer, (D) a photoinitiator, (E) a tackifier having a softening point of 70 to 150°C, and (F) a liquid plasticizer.

[0006] Patent Document 1: JP 2013-216742 A, International Publication No. 2016 / 163152

[0007] As described above, the method of printing a pressure-sensitive adhesive composition into a desired shape and then laminating it to an adherend without preparing a pressure-sensitive adhesive sheet can reduce waste generation. On the other hand, as a method of curing the pressure-sensitive adhesive composition, ultraviolet curing is desirable to avoid heating the adherend, but if the pressure-sensitive adhesive composition is exposed without being covered with a separator during curing, sufficient ultraviolet reactivity may not be obtained. Furthermore, since conventional pressure-sensitive adhesive compositions have too high adhesive strength, there has been a demand for a printing ultraviolet-curable composition with excellent removability (reworkability).

[0008] An object of the present invention is to provide an ultraviolet-curable composition for printing that has excellent printability and removability, and a method for producing a laminate using the ultraviolet-curable composition for printing.

[0009] Disclosure 1 relates to an ultraviolet-curable composition for printing containing a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, a photopolymerization initiator, and a thermoplastic resin, and the ultraviolet-curable composition for printing is coated on a substrate, and the coated surface is not sealed, and in an atmospheric environment, light having a wavelength of 280 nm or more and 480 nm or less is irradiated at an irradiance of 60 mW / cm. ２ , irradiation amount 900mJ / cm ２ A cured product having a thickness of 100 μm obtained by irradiating under the conditions of ４ Disclosure 2 is a method for producing a UV-curable composition for printing, which is coated on a substrate, and the coated surface is not sealed, and is exposed to light with a wavelength of 280 nm or more and 480 nm or less at an irradiance of 60 mW / cm. ２ , irradiation amount 900mJ / cm ２ A 100 μm thick cured product obtained by irradiating under the conditions of 1) was immersed in tetrahydrofuran and filtered. The mass was measured within 3 minutes after wiping off the tetrahydrofuran on the surface. １ (g), W １The cured product was dried at 110°C for 60 minutes and the mass was calculated as W ２ (g), W １ / W ２ The ultraviolet-curable composition for printing according to Disclosure 1, wherein the swelling ratio, represented by the formula (I), is 1.0 or more and 6.0 or less. Disclosure 3 is the ultraviolet-curable composition for printing according to Disclosure 1 or 2, wherein the content of the polyfunctional (meth)acrylic monomer in the ultraviolet-curable composition for printing is 3% by mass or more and 99% by mass or less. Disclosure 4 is the ultraviolet-curable composition for printing according to Disclosure 3, wherein the content of the polyfunctional (meth)acrylic monomer in the ultraviolet-curable composition for printing is 6% by mass or more and 30% by mass or less. Disclosure 5 is the ultraviolet-curable composition for printing according to Disclosure 1, 2, 3, or 4, further comprising a polymerizable carbon-carbon double bond-containing nitrogen compound, wherein the content of the polymerizable carbon-carbon double bond-containing nitrogen compound is 0.5 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the ultraviolet-curable composition for printing excluding the thermoplastic resin. Disclosure 6 is the ultraviolet-curable composition for printing according to Disclosures 1, 2, 3, 4, or 5, which has a viscosity of 0.1 mPa·s or more and 100,000 mPa·s as measured at 25° C. using an E-type viscometer. Disclosure 7 is an ultraviolet-curable composition for printing containing a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, a photopolymerization initiator, and a thermoplastic resin, wherein the ultraviolet-curable composition for printing is applied to a substrate, and the upper surface of the coating is not sealed, and in an atmospheric environment, light having a wavelength of 280 nm or more and 480 nm or less is irradiated at an irradiance of 60 mW / cm. ２ , irradiation amount 900mJ / cm ２ The cured product having a thickness of 100 μm obtained by irradiating under the conditions of 1. above was immersed in tetrahydrofuran, filtered, and the mass measured within 3 minutes after wiping off the tetrahydrofuran on the surface was determined as W １ (g), W １ The cured product was dried at 110°C for 60 minutes and the mass was calculated as W ２ (g), W １ / W ２and a glass transition temperature of 70°C or lower. Disclosure 8 is the UV-curable composition for printing according to Disclosure 7, wherein the content of the polyfunctional (meth)acrylic monomer in the UV-curable composition for printing is 1% by mass or more and 99% by mass or less. Disclosure 9 is the UV-curable composition for printing according to Disclosure 8, wherein the content of the polyfunctional (meth)acrylic monomer in the UV-curable composition for printing is 3% by mass or more and 45% by mass or less. Disclosure 10 is the UV-curable composition for printing according to Disclosure 7, 8, or 9, further comprising a polymerizable carbon-carbon double bond-containing nitrogen compound, wherein the content of the polymerizable carbon-carbon double bond-containing nitrogen compound is 0.5 parts by mass or more and 55 parts by mass or less per 100 parts by mass of the total UV-curable composition for printing excluding the thermoplastic resin. Disclosure 11 is the UV-curable composition for printing according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10, wherein the content of the thermoplastic resin in the UV-curable composition for printing is 1% by mass or more and 60% by mass or less. Disclosure 12 is the UV-curable composition for printing according to Disclosure 11, wherein the content of the thermoplastic resin in the UV-curable composition for printing is 10% by mass or more and 40% by mass or less. Disclosure 13 is the UV-curable composition for printing according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12, which is used for screen printing or flexographic printing. Disclosure 14 is a method for producing a laminate, comprising applying the UV-curable composition for printing according to Disclosure 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, or 13 onto a first adherend, exposing the composition to light to form an adhesive layer, and attaching a second adherend to the adhesive layer to produce a laminate. Disclosure 15 relates to the method for producing a laminate according to Disclosure 14, wherein the method for applying the ultraviolet-curable composition for printing is screen printing or flexographic printing, and the ultraviolet-curable composition for printing is partially applied onto the first adherend. The present invention is described in detail below.

[0010] Hereinafter, the UV-curable composition for printing according to Disclosure 1 will also be referred to as the "UV-curable composition for printing according to Invention 1," and the UV-curable composition for printing according to Disclosure 7 will also be referred to as the "UV-curable composition for printing according to Invention 2." Furthermore, matters common to the UV-curable composition for printing according to Invention 1 and the UV-curable composition for printing according to Invention 2 will be described as the "UV-curable composition for printing according to the present invention." The present inventors investigated how to obtain a UV-curable composition for printing containing a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, a photopolymerization initiator, and a thermoplastic resin, and then cure the composition under specific conditions to obtain a cured product having a shear storage modulus at 150°C of a specific value or greater. As a result, they discovered that a UV-curable composition for printing with excellent printability and removability could be obtained, leading to the completion of Invention 1. Furthermore, the present inventors have investigated how to prepare an ultraviolet-curable composition for printing containing a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, a photopolymerization initiator, and a thermoplastic resin, and then cure the composition under specific conditions to obtain a cured product having a swelling ratio when immersed in tetrahydrofuran and a glass transition temperature within specific ranges. As a result, they have found that it is possible to obtain an ultraviolet-curable composition for printing that has excellent printability and removability, and have completed Invention 2.

[0011] The UV-curable composition for printing of the present invention contains a monofunctional (meth)acrylic monomer. By containing the monofunctional (meth)acrylic monomer, the UV-curable composition for printing of the present invention has excellent adhesion to various substrates. In this specification, the term "(meth)acrylic" refers to acrylic or methacrylic, the term "monofunctional (meth)acrylic monomer" refers to a monomer having one (meth)acryloyl group in one molecule, and the term "(meth)acryloyl" refers to acryloyl or methacryloyl.

[0012] Examples of the monofunctional (meth)acrylic monomer include monofunctional (meth)acrylic acid ester compounds and monofunctional (meth)acrylamide compounds.

[0013] Examples of the monofunctional (meth)acrylic acid ester compound include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-heptyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, isomyristyl (meth)acrylate, stearyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. , cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, bicyclopentenyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, methoxyethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, tetrahydrofurfuryl alcohol acrylic acid polymer ester, ethyl carbitol (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, 1H,1H,5H-Octafluoropentyl (meth)acrylate, imide (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 2-(meth)acryloyloxyethyl succinate, 2-(meth)acryloyloxyethyl hexahydrophthalate, 2-(meth)acryloyloxyethyl 2-hydroxypropyl phthalate, 2-(meth)acryloyloxyethyl phosphate, (3-ethyloxetan-3-yl)methyl (meth)acrylate, 2-(((butylamino)carbonyl)oxy)ethyl (meth)acrylate, (3-propyloxetan-3-yl)methyl (meth)acrylate, (3-butyloxetan-3-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)ethyl (meth)acrylate , (3-ethyloxetan-3-yl)propyl (meth)acrylate, (3-ethyloxetan-3-yl)butyl (meth)acrylate, (3-ethyloxetan-3-yl)pentyl (meth)acrylate, (3-ethyloxetan-3-yl)hexyl (meth)acrylate, γ-butyrolactone (meth)acrylate, (2,2-dimethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-methyl-2-isobutyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (2-cyclohexyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, cyclic trimethylolpropane formal acrylate, and the like.

[0014] Examples of the monofunctional (meth)acrylamide compound include N,N-dimethyl(meth)acrylamide, N-(meth)acryloylmorpholine, N-hydroxyethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, and N,N-dimethylaminopropyl(meth)acrylamide.

[0015] The preferred lower limit of the content of the monofunctional (meth)acrylic monomer in the ultraviolet-curable composition for printing of the present invention is 10% by mass, and the preferred upper limit is 80% by mass. By having the content of the monofunctional (meth)acrylic monomer in this range, the resulting ultraviolet-curable composition for printing will have better printability and adhesion to various substrates. The more preferred lower limit of the content of the monofunctional (meth)acrylic monomer is 20% by mass, and the more preferred upper limit is 60% by mass.

[0016] The ultraviolet-curable composition for printing of the present invention contains a polyfunctional (meth)acrylic monomer. The polyfunctional (meth)acrylic monomer serves as a cross-linking component, and by containing the polyfunctional (meth)acrylic monomer, the ultraviolet-curable composition for printing of the present invention has excellent printability and removability. In this specification, the "polyfunctional (meth)acrylic monomer" means a monomer having two or more (meth)acryloyl groups in one molecule.

[0017] Examples of the polyfunctional (meth)acrylic monomer include polyfunctional urethane (meth)acrylate, polyfunctional (meth)acrylic acid ester compound, polyfunctional epoxy (meth)acrylate, etc. In this specification, the term "(meth)acrylate" means acrylate or methacrylate, and the term "epoxy (meth)acrylate" refers to a compound in which all epoxy groups in an epoxy compound have reacted with (meth)acrylic acid.

[0018] The polyfunctional urethane (meth)acrylate can be obtained, for example, by reacting an isocyanate compound with a (meth)acrylic acid derivative having a hydroxyl group in the presence of a catalytic amount of a tin compound.

[0019] Examples of the isocyanate compound that can be used as a raw material for the polyfunctional urethane (meth)acrylate include isophorone diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), hydrogenated MDI, polymeric MDI, 1,5-naphthalene diisocyanate, norbornane diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, lysine diisocyanate, triphenylmethane triisocyanate, tris(isocyanatephenyl)thiophosphate, tetramethylxylylene diisocyanate, and 1,6,11-undecane triisocyanate.

[0020] Furthermore, as the isocyanate compound serving as a raw material for the polyfunctional urethane (meth)acrylate, a chain-extended isocyanate compound obtained by reacting a polyol with an excess of an isocyanate compound can also be used. Examples of the polyol include ethylene glycol, propylene glycol, glycerin, sorbitol, trimethylolpropane, carbonate diol, polyether diol, polyester diol, and polycaprolactone diol.

[0021] Examples of the (meth)acrylic acid derivatives having a hydroxyl group include hydroxyalkyl mono(meth)acrylates, mono(meth)acrylates of dihydric alcohols, and mono(meth)acrylates or di(meth)acrylates of trihydric alcohols. Examples of the hydroxyalkyl mono(meth)acrylates include 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate, 2-hydroxybutyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate. Examples of the dihydric alcohols include ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and polyethylene glycol. Examples of the trihydric alcohols include trimethylolethane, trimethylolpropane, and glycerin.

[0022] Examples of the polyfunctional (meth)acrylic acid ester compound include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 2-n-butyl-2-ethyl-1,3-propanediol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, ethylene oxide-added bisphenol A di(meth)acrylate, propylene oxide-added bisphenol A di(meth)acrylate, ethylene oxide-added bisphenol F di(meth)acrylate, dimethyloldicyclopentadienyl di(meth)acrylate, ethylene oxide-modified isocyanuric acid di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl (meth)acrylate, carbonate diol di(meth)acrylate, polyether diol di(meth)acrylate, polyester diol di(meth)acrylate, polycaprolactone diol di(meth)acrylate, polybutadiene diol di(meth)acrylate, tri Examples of the acrylate include cyclodecane dimethanol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethylene oxide-added trimethylolpropane tri(meth)acrylate, propylene oxide-added trimethylolpropane tri(meth)acrylate, caprolactone-modified trimethylolpropane tri(meth)acrylate, ethylene oxide-added isocyanuric acid tri(meth)acrylate, glycerin tri(meth)acrylate, propylene oxide-added glycerin tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tris(meth)acryloyloxyethyl phosphate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified dipentaerythritol hexa(meth)acrylate.

[0023] Examples of the polyfunctional epoxy (meth)acrylate include bisphenol A type epoxy (meth)acrylate, bisphenol F type epoxy (meth)acrylate, bisphenol E type epoxy (meth)acrylate, and caprolactone-modified versions of these.

[0024] The polyfunctional (meth)acrylic monomer preferably has a lower limit of double bond concentration of 4.0 mol%. A double bond concentration of 4.0 mol% or higher improves crosslink density, resulting in superior removability of the UV-curable printing composition. A more preferred lower limit of the double bond concentration is 8.0 mol%. There is no particular preferred upper limit for the double bond concentration, but the practical upper limit is 30 mol%. In this specification, the double bond concentration is a value obtained by dividing the sum of the molecular weights of the carbon-carbon double bonds contained in the polyfunctional (meth)acrylic monomer by the molecular weight of the polyfunctional (meth)acrylic monomer. The molecular weight of the carbon-carbon double bond refers to the sum of the atomic weights of the carbon atoms constituting the carbon-carbon double bond and the hydrogen atoms bonded to those carbon atoms. When multiple polyfunctional (meth)acrylic monomers are used, the preferred and more preferred lower limits of the double bond concentration refer to the mass average values.

[0025] The preferred lower limit of the content of the polyfunctional (meth)acrylic monomer in the UV-curable composition for printing of Invention 1 is 3% by mass, and the preferred upper limit is 99% by mass. When the content of the polyfunctional (meth)acrylic monomer in the UV-curable composition for printing of Invention 1 is within this range, the resulting UV-curable composition for printing has even better printability and removability. The more preferred lower limit of the content of the polyfunctional (meth)acrylic monomer in the UV-curable composition for printing of Invention 1 is 6% by mass, and the more preferred upper limit is 30% by mass. The preferred lower limit of the content of the polyfunctional (meth)acrylic monomer in the UV-curable composition for printing of Invention 2 is 1% by mass, and the preferred upper limit is 99% by mass. When the content of the polyfunctional (meth)acrylic monomer in the UV-curable composition for printing of Invention 2 is within this range, the resulting UV-curable composition for printing has even better printability and removability. The more preferred lower limit of the content of the polyfunctional (meth)acrylic monomer in the ultraviolet-curable composition for printing of the second invention is 3% by mass, and the more preferred upper limit is 45% by mass.

[0026] The ultraviolet-curable composition for printing of the present invention preferably further contains a nitrogen-containing compound containing a polymerizable carbon-carbon double bond. By containing the nitrogen-containing compound containing a polymerizable carbon-carbon double bond, the resulting ultraviolet-curable composition for printing has superior reactivity in the presence of oxygen. Note that a nitrogen-containing compound having a (meth)acryloyl group is treated as the monofunctional (meth)acrylic monomer or the polyfunctional (meth)acrylic monomer, rather than as the nitrogen-containing compound containing a polymerizable carbon-carbon double bond.

[0027] Examples of the nitrogen-containing compound containing a polymerizable carbon-carbon double bond include nitrogen-containing vinyl compounds and maleimide compounds.

[0028] The nitrogen-containing vinyl compound is preferably an amide compound having a vinyl group, more preferably a cyclic amide compound having a vinyl group.

[0029] The cyclic amide compound having a vinyl group preferably has a lactam structure, and more preferably is a compound represented by the following formula (1):

[0030]

[0031] In formula (1), n ​​represents an integer of 2 to 6.

[0032] Examples of the compound represented by the formula (1) include N-vinyl-2-pyrrolidone, N-vinyl-ε-caprolactam, etc. Among these, N-vinyl-ε-caprolactam is preferred.

[0033] Among the above-mentioned amide compounds having a vinyl group, examples of compounds other than the above-mentioned cyclic amide compounds having a vinyl group include N-vinylacetamide.

[0034] Examples of the maleimide compound include N-phenylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, N-(2-methylphenyl)maleimide, N-(4-methylphenyl)maleimide, N-(2,6-diethylphenyl)maleimide, N-methylmaleimide, N-ethylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-benzylmaleimide, N-phenylmethylmaleimide, N-octadecenylmaleimide, N-dodecenylmaleimide, N-(4-carboxycyclohexylmethyl)maleimide, 4-hydroxyphenylmaleimide, and N-(4-anilinophenyl)maleimide.

[0035] The preferred lower limit of the content of the polymerizable carbon-carbon double bond-containing nitrogen compound per 100 parts by mass of the total UV-curable composition for printing excluding the thermoplastic resin described below is 0.1 parts by mass, and the preferred upper limit is 90 parts by mass. When the content of the polymerizable carbon-carbon double bond-containing nitrogen compound is within this range, the resulting UV-curable composition for printing will have superior reactivity in the presence of oxygen and superior adhesion to various substrates. The more preferred lower limit of the content of the polymerizable carbon-carbon double bond-containing nitrogen compound is 0.5 parts by mass, and the more preferred upper limit is 55 parts by mass.

[0036] The ultraviolet-curable composition for printing contains a photopolymerization initiator. As the photopolymerization initiator, a photoradical polymerization initiator is preferably used. The photopolymerization initiators may be used alone or in combination of two or more.

[0037] Examples of the photoradical polymerization initiator include a benzophenone compound, an alkylphenone compound, an acylphosphine oxide compound, a titanocene compound, an oxime ester compound, a benzoin ether compound, a thioxanthone compound, etc. Examples of the alkylphenone compound include an acetophenone compound, etc.

[0038] Specific examples of the photoradical polymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2-benzyl-2-(dimethylamino)-1-(4-(morpholino)phenyl)-1-butanone, 2-(dimethylamino)-2-((4-methylphenyl)methyl)-1-(4-(4-morpholinyl)phenyl)-1-butanone, 2,2-dimethoxy-1,2-diphenylethan-1-one, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2- Examples include methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-(phenylthio)phenyl)-1,2-octanedione 2-(O-benzoyloxime), 2,4,6-trimethylbenzoyldiphenylphosphine oxide, benzoin methyl ether, benzoin ethyl ether, and benzoin isopropyl ether.

[0039] The preferred lower limit of the content of the photopolymerization initiator in the ultraviolet-curable composition for printing of the present invention is 0.2 parts by mass, and the preferred upper limit is 10 parts by mass. When the content of the photopolymerization initiator is within this range, the resulting ultraviolet-curable composition for printing has better storage stability, curability, and adhesion to various substrates. The more preferred lower limit of the content of the photopolymerization initiator is 0.4 parts by mass, and the more preferred upper limit is 8 parts by mass.

[0040] The ultraviolet-curable composition for printing of the present invention contains a thermoplastic resin. By containing the thermoplastic resin, the ultraviolet-curable composition for printing of the present invention has excellent printability.

[0041] The thermoplastic resin may or may not be photoreactive.

[0042] Examples of the thermoplastic resin include solventless acrylic polymers. Examples of the solventless acrylic polymer include polymers of at least one monomer selected from (meth)acrylic acid alkyl esters having an alkyl group containing 1 to 20 carbon atoms, or copolymers of such monomers with other copolymerizable monomers. Commercially available solventless acrylic polymers include the ARUFON-UP1000 series, UH2000 series, and UC3000 series (all manufactured by Toagosei Co., Ltd.), the Kurariti LA series, and the Kurariti LK series (all manufactured by Kuraray Co., Ltd.).

[0043] The preferred lower limit of the content of the thermoplastic resin in the UV-curable composition for printing of the present invention is 1% by mass, and the preferred upper limit is 60% by mass. By ensuring that the content of the thermoplastic resin is within this range, the viscosity of the resulting UV-curable composition for printing is improved, allowing for the formation of a thick coating film, resulting in superior printability, and preventing a decrease in adhesion at high temperatures. The more preferred lower limit of the content of the thermoplastic resin is 10% by mass, and the more preferred upper limit is 40% by mass.

[0044] The ultraviolet-curable composition for printing of the present invention may contain a thermosetting resin or a moisture-curing resin, and thus may exhibit reactivity to triggers such as heat and moisture.

[0045] The ultraviolet-curable composition for printing of the present invention may further contain a tackifier, such as a rosin-based resin or a terpene-based resin, within the scope of not impairing the object of the present invention.

[0046] The ultraviolet-curable composition for printing of the present invention may contain a plasticizer, such as an organic acid ester, an organic phosphate ester, or an organic phosphite ester.

[0047] Examples of the organic acid esters include monobasic organic acid esters and polybasic organic acid esters. Examples of the monobasic organic acid esters include glycol esters obtained by reacting monobasic organic acids such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, pelargonic acid (n-nonylic acid), and decylic acid with glycols such as triethylene glycol, tetraethylene glycol, and tripropylene glycol. Examples of the polybasic organic acid esters include ester compounds obtained by reacting polybasic organic acids such as adipic acid, sebacic acid, and azelaic acid with alcohols having a linear or branched structure and 4 to 8 carbon atoms.

[0048] Specific examples of the organic acid ester include triethylene glycol di-2-ethylbutyrate (3GH), triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, and triethylene glycol di-n-heptanoate (3G7). Other examples include tetraethylene glycol di-n-heptanoate (4G7), tetraethylene glycol di-2-ethylhexanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, and 1,3-propylene glycol di-2-ethylbutyrate. Further examples include 1,4-butylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, and dipropylene glycol di-2-ethylbutyrate. Other examples include triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate (4GH), diethylene glycol dicaprylate, dihexyl adipate (DHA), dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, etc. Other examples include oil-modified sebacic acid alkyd, a mixture of a phosphate ester and an adipate ester, and a mixed adipate ester prepared from an alkyl alcohol having 4 to 9 carbon atoms and a cyclic alcohol having 4 to 9 carbon atoms.

[0049] Examples of the organic phosphate ester or organic phosphite ester include compounds obtained by the condensation reaction between phosphoric acid or phosphorous acid and an alcohol. Of these, compounds obtained by the condensation reaction between an alcohol having 1 to 12 carbon atoms and phosphoric acid or phosphorous acid are preferred. Examples of the alcohol having 1 to 12 carbon atoms include methanol, ethanol, butanol, hexanol, 2-ethylbutanol, heptanol, octanol, 2-ethylhexanol, decanol, dodecanol, butoxyethanol, butoxyethoxyethanol, and benzyl alcohol. Examples of the organic phosphate ester or organic phosphite ester include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, tributyl phosphate, tri(2-ethylhexyl) phosphate, tri(butoxyethyl) phosphate, tri(2-ethylhexyl) phosphite, isodecylphenyl phosphate, and triisopropyl phosphate.

[0050] The ultraviolet-curable composition for printing of the present invention may contain a defoaming agent, such as a silicone-based defoaming agent, an acrylic polymer-based defoaming agent, a vinyl ether polymer-based defoaming agent, or an olefin polymer-based defoaming agent.

[0051] The ultraviolet-curable composition for printing of the present invention may further contain various known additives, such as a viscosity modifier, a silane coupling agent, a sensitizer, a heat curing agent, a cure retarder, an antioxidant, a storage stabilizer, a dispersant, a filler, etc. From the viewpoint of preventing a decrease in ultraviolet reactivity, the ultraviolet-curable composition for printing of the present invention preferably contains substantially no organic solvent, and specifically, the content of the organic solvent is preferably 1.5% by mass or less relative to 100% by mass of the ultraviolet-curable composition for printing.

[0052] Examples of a method for preparing the ultraviolet-curable composition for printing of the present invention include a method of using a mixer to mix the monofunctional (meth)acrylic monomer, the polyfunctional (meth)acrylic monomer, the photopolymerization initiator, the thermoplastic resin, and additives added as needed, etc. Examples of the mixer include a homodisper, a homomixer, a universal mixer, a planetary mixer, a kneader, and a three-roll mill.

[0053] The ultraviolet-curable composition for printing of the present invention 1 is prepared by applying the ultraviolet-curable composition for printing to a substrate, and then irradiating the coated surface with light having a wavelength of 280 nm or more and 480 nm or less at an irradiance of 60 mW / cm under an atmospheric environment without sealing the coated surface. ２ , irradiation amount 900mJ / cm ２ The cured product having a thickness of 100 μm obtained by irradiating under the conditions of ４ Pa. At this time, the total irradiance is 60 mW / cm ２ and an irradiation dose of 900 mJ / cm ２ If the cured product has a shear storage modulus of 5.0×10 at 150° C., the cured product may be irradiated with light of multiple wavelengths in the wavelength range of 280 nm to 480 nm (the same applies to the swelling ratio and glass transition temperature of the cured product described later). As the substrate, a PET film with a release treatment applied to the surface (release PET film) is preferably used. ４ When the shear storage modulus of the cured product is 7.0 × 10 Pa or more, the cured product has a high crosslink density and low interfacial adhesive strength, and therefore the cured product has excellent removability. ４ Pa, and a more preferable lower limit is 8.0 × 10 ４ From the viewpoint of adhesion to various substrates, the preferred upper limit of the shear storage modulus at 150°C of the cured product is 5.0 x 10 ６ Pa, and a more preferable upper limit is 1.0 × 10 ６Pa. Specifically, the shear storage modulus of the cured product at 150°C can be measured, for example, according to the following procedure. First, the ultraviolet-curable composition for printing is coated onto a release PET film as a substrate. Then, in an atmospheric environment without sealing the coated surface, a light irradiation device is used to irradiate the cured product with light having a wavelength of 280 nm or more and 480 nm or less, preferably 315 nm or more and 480 nm or less, at an irradiance of 60 mW / cm. ２ , irradiation amount 900mJ / cm ２ The ultraviolet-curable composition for printing is cured by irradiating the composition under the above conditions to obtain a cured product having a thickness of 100 μm. For example, an M UVBA (manufactured by ITEC Co., Ltd.) can be used as the light irradiation device. The shear storage modulus at 150°C can be determined by performing dynamic viscoelasticity measurement on the obtained cured product using a dynamic viscoelasticity measuring device under the following conditions: shear method, measurement temperature -100°C to 200°C, heating rate 5°C / min, strain 1.0%, and frequency 1 Hz.

[0054] The shear storage modulus of the cured product at 150° C. can be increased by increasing the content of the polyfunctional (meth)acrylic monomer. The shear storage modulus of the cured product at 150° C. can also be increased by using a polyfunctional (meth)acrylic monomer having a large number of (meth)acryloyl groups per molecule.

[0055] The ultraviolet-curable composition for printing of the second invention is prepared by applying the ultraviolet-curable composition for printing to a substrate, and then irradiating the coated surface with light having a wavelength of 280 nm or more and 480 nm or less at an irradiance of 60 mW / cm under atmospheric conditions without sealing the coated surface. ２ , irradiation amount 900mJ / cm ２ The cured product having a thickness of 100 μm obtained by irradiating under the conditions of 1. above was immersed in tetrahydrofuran, filtered, and the mass measured within 3 minutes after wiping off the tetrahydrofuran on the surface was determined as W １ (g), W １ The cured product was dried at 110°C for 60 minutes and the mass was calculated as W ２ (g), W １ / W ２The ultraviolet-curable composition for printing of the present invention 1 has a swelling ratio of 1.0 (lower limit) and 6.0 (upper limit). In addition, the ultraviolet-curable composition for printing of the present invention 1 is coated on a substrate, and the coated surface is not sealed. When the composition is irradiated with light having a wavelength of 280 nm or more and 480 nm or less at an irradiance of 60 mW / cm under atmospheric conditions, the swelling ratio is 1.0 (lower limit) and 6.0 (upper limit). ２ , irradiation amount 900mJ / cm ２ A 100 μm thick cured product obtained by irradiating under the conditions of 1) was immersed in tetrahydrofuran and filtered. The mass was measured within 3 minutes after wiping off the tetrahydrofuran on the surface. １ (g), W １ The cured product was dried at 110°C for 60 minutes and the mass was calculated as W ２ (g), W １ / W ２ The preferred lower limit of the swelling ratio represented by the formula (2) is 1.0, and the preferred upper limit is 6.0. In this case, when the total irradiance is 60 mW / cm ２ and an irradiation dose of 900 mJ / cm ２ As long as the cured product satisfies the above condition, light of multiple wavelengths in the wavelength range of 280 nm to 480 nm may be irradiated (the same applies to the glass transition temperature of the cured product described below). A PET film with a release-treated surface (release PET film) is preferably used as the substrate. When the swelling ratio of the cured product is 1.0 or more, the UV-curable composition for printing of the present invention does not become too hard and exhibits excellent adhesion to various substrates. When the swelling ratio of the cured product is 6.0 or less, the UV-curable composition for printing of the present invention exhibits excellent removability. The upper limit of the swelling ratio of the cured product in the UV-curable composition for printing of Invention 2 is preferably 10. Furthermore, the upper limit of the swelling ratio of the cured product in the UV-curable composition for printing of Invention 1 is more preferably 10. Specifically, the swelling ratio of the cured product can be measured, for example, according to the following procedure. First, the UV-curable composition for printing is coated on a release PET film as a substrate. Thereafter, without sealing the coated surface, a light irradiation device is used to irradiate the coated surface with light having a wavelength of 280 nm or more and 480 nm or less, preferably 315 nm or more and 480 nm or less, at an irradiance of 60 mW / cm in an atmospheric environment. ２ , irradiation amount 900mJ / cm２ By irradiating under the above conditions, the ultraviolet-curable composition for printing is cured to obtain a cured product having a thickness of 100 μm. As the light irradiation device, for example, M UVBA (manufactured by ITEC Co., Ltd.) can be used. Approximately 0.1 g of the obtained cured product is weighed and immersed in tetrahydrofuran at 23°C for 24 hours. After immersion, the cured product is filtered, the tetrahydrofuran is wiped off, and then it is weighed again (W １ (g)). Then, W １ The cured product for which the value of W was measured is dried at 110°C for 60 minutes and then weighed again (W ２ (g)). The swelling ratio of the cured product is W １ W ２ It can be obtained by dividing by

[0056] The swelling ratio of the cured product can be reduced by increasing the content of the polyfunctional (meth)acrylic monomer, or by using a polyfunctional (meth)acrylic monomer having a large number of (meth)acryloyl groups per molecule.

[0057] The ultraviolet-curable composition for printing of the second invention is prepared by applying the ultraviolet-curable composition for printing to a substrate, and then irradiating the coated surface with light having a wavelength of 280 nm or more and 480 nm or less at an irradiance of 60 mW / cm under atmospheric conditions without sealing the coated surface. ２ , irradiation amount 900mJ / cm ２ The upper limit of the glass transition temperature of a 100 μm-thick cured product obtained by irradiating the composition under the conditions of (a) to (c) above is 70° C. The ultraviolet-curable composition for printing of the present invention 1 can be cured by irradiating the composition on a substrate with light having a wavelength of 280 nm or more and 480 nm or less at an irradiance of 60 mW / cm under atmospheric conditions without sealing the coated surface. ２ , irradiation amount 900mJ / cm ２The preferred upper limit of the glass transition temperature of a 100 μm-thick cured product obtained by irradiation under the above conditions is 70°C. When the glass transition temperature of the cured product is 70°C or less, the ultraviolet-curable composition for printing of the present invention exhibits excellent removability. The preferred upper limit of the glass transition temperature of the cured product is 55°C. Furthermore, from the viewpoint of adhesion to various substrates, the preferred lower limit of the glass transition temperature of the cured product is -30°C, and more preferably -20°C. Specifically, the glass transition temperature of the cured product can be measured, for example, according to the following procedure. That is, first, the ultraviolet-curable composition for printing is coated on a release PET film as a substrate. Thereafter, using a light irradiation device, light having a wavelength of 280 nm or more and 480 nm or less, preferably 315 nm or more and 480 nm or less, is irradiated at an irradiance of 60 mW / cm under atmospheric conditions without sealing the upper surface of the coating. ２ , irradiation amount 900mJ / cm ２ The UV-curable composition for printing is cured by irradiating under these conditions to obtain a cured product having a thickness of 100 μm. For example, an M UVBA (manufactured by ITEC Co., Ltd.) can be used as the light irradiation device. The cured product thus obtained is subjected to dynamic viscoelasticity measurement using a dynamic viscoelasticity measuring device under the conditions of a shear method, a measurement temperature of -100°C to 200°C, a heating rate of 5°C / min, a strain of 1.0%, and a frequency of 1 Hz. The tan δ peak temperature obtained when the measurement temperature is 100°C to 200°C can be determined as the glass transition temperature.

[0058] Among the monomer components contained in the UV-curable composition for printing of the present invention, the greater the proportion of monomer components with higher glass transition temperatures, the higher the glass transition temperature of the cured product, and the greater the proportion of monomer components with lower glass transition temperatures, the lower the glass transition temperature of the cured product. Therefore, by adjusting the blending ratio of these monomer components, the glass transition temperature of the cured product can be adjusted.

[0059] The ultraviolet-curable composition for printing of Invention 1 has a viscosity, measured at 25°C using an E-type viscometer, of preferably 0.1 mPa·s lower limit and 100,000 mPa·s upper limit. Because the viscosity is in this range, the ultraviolet-curable composition for printing of Invention 1 can be suitably applied by screen printing or flexographic printing. The ultraviolet-curable composition for printing of Invention 1 has a more preferred lower limit and 50,000 mPa·s upper limit of the viscosity, both of which are 0.5 mPa·s and 50,000 mPa·s upper limit. The viscosity of the ultraviolet-curable composition for printing of Invention 2 is not particularly limited and is adjusted depending on the application method. For example, when applied by screen printing, the preferred lower limit and upper limit of the viscosity at 25°C are 3.5 Pa·s and 100 Pa·s, respectively, and when applied by flexographic printing, the preferred lower limit and upper limit of the viscosity at 25°C are 0.5 Pa·s and 1.5 Pa·s, respectively. The viscosity can be measured, for example, using a VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer, by selecting an appropriate rotation speed from 1 to 100 rpm based on the optimum torque number in each viscosity range using an appropriate cone plate.

[0060] The UV-curable composition for printing of the present invention is used for printing. Forming an adhesive layer by applying a desired pattern to an adherend (substrate) by printing has the advantage of eliminating the cutting step compared to obtaining a composition of the desired shape by cutting a sheet-like composition immediately before lamination. As a result, it is possible to suppress waste generation and reduce the environmental load. In particular, the UV-curable composition for printing of the present invention is preferably used for screen printing or flexographic printing.

[0061] The present invention also provides a method for producing a laminate, which comprises applying the UV-curable composition for printing of the present invention to a first adherend, exposing the composition to light to form an adhesive layer, and attaching a second adherend to the adhesive layer to produce a laminate. Screen printing or flexographic printing is preferably used as a method for applying the UV-curable composition for printing. Furthermore, the UV-curable composition for printing is preferably applied partially onto the first adherend.

[0062] According to the present invention, it is possible to provide an ultraviolet-curable composition for printing that has excellent printability and removability. Furthermore, according to the present invention, it is possible to provide a method for producing a laminate using the ultraviolet-curable composition for printing.

[0063] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0064] (Examples 1-1 to 1-21, Comparative Examples 1-1 to 1-7) Each material was mixed in a planetary mixer (Thinky Corporation's "Awatori Rentaro") according to the blending ratios shown in Tables 1 to 3 to obtain each ultraviolet-curable composition for printing in the Examples and Comparative Examples. Details of the materials listed by abbreviations in the tables are as follows.(Monofunctional (meth)acrylic monomers) CBA: ethyl carbitol acrylate (manufactured by Osaka Organic Chemical Industry Ltd., "Viscoat #190") #192: phenoxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd., "Viscoat #192") #150D: tetrahydrofurfuryl alcohol acrylic acid polymer ester (manufactured by Osaka Organic Chemical Industry Ltd., "Viscoat #150D") IDAA: isodecyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.) 4-HBA: 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.) (Polyfunctional (meth)acrylic monomers) NP-A: neopentyl glycol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Acrylate NP-A") TMPTA: trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Industry Ltd., "Viscoat #295") DPCA-120: caprolactone-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., "KAYARAD DPCA-120") CN9004: aliphatic urethane acrylate (manufactured by Sartomer Corporation) (polymerizable carbon-carbon double bond-containing nitrogen compound) NVC: N-vinyl-ε-caprolactam (manufactured by Tokyo Chemical Industry Co., Ltd.) NPMI: N-phenylmaleimide (manufactured by Nippon Shokubai Co., Ltd.) NCMI: N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.) (photopolymerization initiator) Omnirad TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by IGM Resins) Omnirad 819: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins) Omnirad 184: 1-hydroxycyclohexyl phenyl ketone (manufactured by IGM Resins) (thermoplastic resin) LA2140: acrylic block copolymer (manufactured by Kuraray) LA2330: acrylic block copolymer (manufactured by Kuraray) LK9243: acrylic block copolymer (manufactured by Kuraray) (defoaming agent) KS-66: oil compound type defoaming agent (manufactured by Shin-Etsu Chemical Co., Ltd.) in which finely powdered silica is blended with silicone oil.

[0065] (Viscosity) 0.4 mL of the obtained ultraviolet-curable composition for printing was sampled, and the viscosity was measured using a VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer with a CP1 cone plate at 25°C and 10 rpm. The results are shown in Tables 1 to 3.

[0066] (Shear storage modulus and glass transition temperature of the cured product at 150°C) The obtained ultraviolet-curable composition for printing was applied to a release PET film (manufactured by Nippa Corporation, "1-E", thickness 50 μm) using an applicator. Thereafter, the upper surface of the coating was not sealed and the cured product was cured in an atmospheric environment using a batch-type UV LED curing device with a wavelength of 365 nm and an illuminance of 20 mW / cm. ２ UV rays with a wavelength of 405 nm and an illuminance of 40 mW / cm ２ The total irradiation amount is 900 mJ / cm ２ The UV-curable printing composition was cured by simultaneously irradiating the UV-curable composition with UV-light so that the cured product had a thickness of 100 μm. The batch-type UV LED curing device used was an M UVBA (manufactured by ITEC Corporation). Dynamic viscoelasticity measurements were performed on the cured product using a dynamic viscoelasticity measuring device (manufactured by IT Measurement & Control Co., Ltd., "DVA-200") under the shear method, with a measurement temperature of -100°C to 200°C, a heating rate of 5°C / min, a strain of 1.0%, and a frequency of 1 Hz. The shear storage modulus at 150°C was determined, and the tan δ peak temperature was calculated as the glass transition temperature. The results are shown in Tables 1 to 3.

[0067] (Swelling ratio of cured product) Approximately 0.1 g of the cured product obtained in the same manner as in "(Shear storage modulus and glass transition temperature of cured product at 150°C)" above was weighed out and immersed in tetrahydrofuran at 23°C for 24 hours. After immersion, the cured product was filtered, the tetrahydrofuran was wiped off, and then it was reweighed (W １ (g)). Then, W １ The cured product for which the value of W was measured was dried at 110°C for 60 minutes and then re-weighed (W ２ (g)). W １ W ２ The swelling ratio of the cured product was calculated by dividing the obtained value by 1. The results are shown in Tables 1 to 3.

[0068] <Evaluation> The ultraviolet-curable compositions for printing obtained in Examples 1-1 to 1-21 and Comparative Examples 1-1 to 1-7 were evaluated as follows. The results are shown in Tables 1 to 3.

[0069] (Adhesive Strength, Peel Residue, Removability) A cured product obtained in the same manner as in "(Shear Storage Modulus and Glass Transition Temperature of Cured Product at 150°C)" above was cut into a width of 2.54 mm and a length of 10 mm. Next, the film was transferred to the inner treated surface of an easy-adhesion polyester film ("Cosmoshine A4100", manufactured by Toyobo Co., Ltd.) so that the unsealed surface was in contact, and the film was cut into a width of 2.54 mm and a length of 20 mm (adhesion surface 10 mm). Next, the release PET film on the side opposite the transfer surface was peeled off, and the exposed surface was attached to a SUS substrate and pressed by moving it back and forth with a 2 kg roller to obtain a test specimen. The obtained test specimen was adjusted to 25°C and stored for 24 hours. After storage, the test specimen was subjected to a 90° peel test at 25°C and a peel rate of 300 mm / min using a variable angle peel force measuring device ("VPA-2", manufactured by Kyowa Interface Science Co., Ltd.) to measure adhesive strength. The adhesive strength of the test piece after storing it at 40°C for 7 days was also measured in the same manner. In addition, the SUS substrate after the 90° peel test on the test piece stored at 25°C for 24 hours was observed to check for the presence or absence of peel residue, and the removability was evaluated according to the following criteria: ○: No peel residue, and adhesive strength after 24 hours storage at 25°C is less than 8.0 N / inch ×: Peel residue is present, or no peel residue is present, but adhesive strength after 24 hours storage at 25°C is 8.0 N / inch or more

[0070] (Printability) [Flexographic printing] Each of the ultraviolet-curable compositions for printing obtained in Examples 1-1 to 1-11, 1-13 to 1-15, 1-19 to 1-21 and Comparative Examples 1-1 to 1-5 and 1-7 was applied to a thickness of 10 μm on a PET film (manufactured by Nippa Corporation, "1-E", thickness 50 μm) using a flexographic printing device, and the printability was evaluated according to the following criteria. The flexographic printing device used was a small flexographic printing tester FC11 (manufactured by MT Tech Co., Ltd.). ○: When the coated surface was smooth and any shape could be printed without bleeding. △: When any shape could be formed but bleeding occurred. ×: When any shape could not be formed. [Screen Printing] Each of the ultraviolet-curable printing compositions obtained in Examples 1-12, 1-16 to 1-18 and Comparative Example 1-6 was screen-printed onto a PET film (Nippa Corporation, "1-E", thickness 50 μm) using a screen printer (SERIA Corporation, "SSA-PC560E"). A pattern-treated 500-mesh printing plate was used to apply a pattern to the PET film, and stringiness upon separation from the screen, leveling of the printed matter, and defoaming were observed. The printability was evaluated according to the following criteria. ○: When stringiness, leveling, and defoaming were good. △: When no stringiness was observed, but the printed surface was slightly rough or defoaming was not observed. ×: When stringiness occurred upon separation from the plate.

[0071]

[0072]

[0073]

[0074] (Examples 2-1 to 2-22, Comparative Examples 2-1 to 2-10) Each material was mixed in a planetary mixer (Thinky Corporation's "Awatori Rentaro") according to the blending ratios shown in Tables 4 to 6 to obtain each ultraviolet-curable composition for printing in the Examples and Comparative Examples. Details of the materials listed by abbreviations in the tables are as follows.(Monofunctional (meth)acrylic monomers) CBA: ethyl carbitol acrylate (manufactured by Osaka Organic Chemical Industry Ltd., "Viscoat #190") #192: phenoxyethyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd., "Viscoat #192") #216: acrylic acid-2-butylcarbamoyloxyethyl ester (manufactured by Osaka Organic Chemical Industry Ltd., "Viscoat #216") M140: N-acryloyloxyethylhexahydrophthalimide (manufactured by Toagosei Co., Ltd.) (polymerizable carbon-carbon double bond-containing nitrogen compounds) NVC: N-vinyl-ε-caprolactam (manufactured by Tokyo Chemical Industry Co., Ltd.) NPMI: N-phenylmaleimide (manufactured by Nippon Shokubai Co., Ltd.) NCMI: N-cyclohexylmaleimide (manufactured by Nippon Shokubai Co., Ltd.) (polyfunctional (meth)acrylic monomers) NP-A: neopentyl glycol diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., "Light Acrylate NP-A") TMPTA: trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Industry Ltd., "Viscoat #295") DPCA-120: caprolactone-modified dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd., "KAYARAD DPCA-120") 160TM: polyether-based multifunctional urethane acrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.) (photopolymerization initiator) Omnirad TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by IGM Resins) Omnirad 819: bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (manufactured by IGM Resins) Omnirad 184: 1-hydroxycyclohexyl phenyl ketone (manufactured by IGM Resins) (thermoplastic resin) LA2140: acrylic block copolymer (manufactured by Kuraray) LA2330: acrylic block copolymer (manufactured by Kuraray) LK9243: acrylic block copolymer (manufactured by Kuraray) (defoaming agent) KS-66: oil compound type defoaming agent (manufactured by Shin-Etsu Chemical Co., Ltd.) in which finely powdered silica is blended with silicone oil.

[0075] (Viscosity) 0.4 mL of the obtained ultraviolet-curable composition for printing was sampled, and the viscosity was measured using a VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer with a CP1 cone plate at 25°C and 10 rpm. The results are shown in Tables 4 to 6.

[0076] (Swelling ratio of cured product) The obtained ultraviolet-curable composition for printing was applied to a release PET film (manufactured by Nippa Corporation, "1-E", thickness 50 μm) using an applicator. Thereafter, without sealing the top surface of the coating, the cured product was cured in an atmospheric environment using a batch-type UV LED curing device with a wavelength of 365 nm and an illuminance of 20 mW / cm. ２ UV rays with a wavelength of 405 nm and an illuminance of 40 mW / cm ２ The total irradiation amount is 900 mJ / cm ２ The UV-curable composition for printing was cured by simultaneous irradiation so that the thickness was 100 μm, thereby obtaining a cured product having a thickness of 100 μm. The batch-type UV LED curing device used was an M UVBA (manufactured by ITEC Co., Ltd.). Approximately 0.1 g of the obtained cured product was weighed and immersed in tetrahydrofuran at 23° C. for 24 hours. After immersion, the cured product was filtered, the tetrahydrofuran was wiped off, and then it was reweighed (W １ (g)). Then, W １ The cured product for which the value of W was measured was dried at 110°C for 60 minutes and then re-weighed (W ２ (g)). W １ W ２ The swelling ratio of the cured product was calculated by dividing the value by 1. The results are shown in Tables 4 to 6.

[0077] (Glass Transition Temperature of Cured Product) For cured products obtained in the same manner as in "(Swelling Ratio of Cured Product)" above, dynamic viscoelasticity measurement was performed using a dynamic viscoelasticity measuring device (manufactured by IT Measurement & Control Co., Ltd., "DVA-200") under the conditions of a shear method, a measurement temperature of -100°C to 200°C, a heating rate of 5°C / min, a strain of 1.0%, and a frequency of 1 Hz. The tan δ peak temperature was determined as the glass transition temperature. The results are shown in Tables 4 to 6.

[0078] <Evaluation> The ultraviolet-curable compositions for printing obtained in Examples 2-1 to 2-22 and Comparative Examples 2-1 to 2-10 were evaluated as follows. The results are shown in Tables 4 to 6.

[0079] (Adhesive strength, peeling residue, removability) The cured product obtained in the same manner as in "(Swelling ratio of the cured product)" above was cut into a width of 2.54 mm and a length of 10 mm, and transferred to the inner treated surface of an easy-adhesion polyester film ("Cosmoshine A4100", manufactured by Toyobo Co., Ltd.) so that the unsealed surface was in contact, and the film was cut into a width of 2.54 mm and a length of 20 mm (adhesion surface 10 mm). Next, the release PET film on the side opposite the transfer surface was peeled off, and the exposed surface was attached to a SUS substrate and pressed by moving it back and forth with a 2 kg roller to obtain a test specimen. The obtained test specimen was adjusted to 25 ° C and stored for 24 hours. After storage, the test specimen was subjected to a 90 ° peel test at 25 ° C and a peel rate of 300 mm / min using an angle variable peel force measuring device ("VPA-2", manufactured by Kyowa Interface Science Co., Ltd.) to measure the adhesive strength. The adhesive strength of the test piece after storing it at 40°C for 7 days was also measured in the same manner. In addition, the SUS substrate after the 90° peel test on the test piece stored at 25°C for 24 hours was observed to check for the presence or absence of peel residue, and the removability was evaluated according to the following criteria: ○: No peel residue, and adhesive strength after 24 hours storage at 25°C is less than 8.0 N / inch ×: Peel residue is present, or no peel residue is present, but adhesive strength after 24 hours storage at 25°C is 8.0 N / inch or more

[0080] (Printability) [Flexographic printing] Each of the ultraviolet-curable compositions for printing obtained in Examples 2-1 to 2-9, 2-12, 2-14 to 2-19, 2-21, and 2-22, and Comparative Examples 2-1 to 2-7 and 2-9 was applied to a thickness of 10 μm on a PET film (manufactured by Nippa Corporation, "1-E", thickness 50 μm) using a flexographic printing device, and the printability was evaluated according to the following criteria. The flexographic printing device used was a small flexographic printing tester FC11 (manufactured by MT Tech Co., Ltd.). ○: When the coated surface was smooth and any shape could be printed without bleeding. △: When any shape could be formed, but bleeding occurred. ×: When any shape could not be formed. [Screen Printing] Each of the printing ultraviolet-curable compositions obtained in Examples 2-10, 2-11, 2-13, and 2-20 and Comparative Examples 2-8 and 2-10 was screen-printed onto a PET film (Nippa Corporation, "1-E", thickness 50 μm) using a screen printer (SERIA Corporation, "SSA-PC560E"). A pattern-treated 500-mesh screen printing plate was used to apply a pattern to the PET film, and stringiness upon separation from the screen plate, leveling of the printed matter, and defoaming were observed. Printability was evaluated according to the following criteria. ○: When stringing, leveling, and defoaming were good △: When there was no stringing, but the printed surface was slightly rough or defoaming was not achieved ×: When stringing occurred when separating the plate

[0081]

[0082]

[0083]

[0084] According to the present invention, it is possible to provide an ultraviolet-curable composition for printing that has excellent printability and removability. Furthermore, according to the present invention, it is possible to provide a method for producing a laminate using the ultraviolet-curable composition for printing.

Claims

1. This is a UV-curable composition for printing containing a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, a photopolymerization initiator, and a thermoplastic resin. The aforementioned UV-curable composition for printing further contains a polymerizable carbon-carbon double bond-containing nitrogen compound, The polymerizable carbon-carbon double bond-containing nitrogen compound is a compound other than a nitrogen compound having a (meth)acryloyl group. The aforementioned UV-curable composition for printing is applied to a substrate, and without sealing the coated surface, light with a wavelength of 280 nm to 480 nm is exposed to the substrate at an irradiance of 60 mW / cm² in an atmospheric environment. ２ , irradiation amount 900mJ / cm ２ For a 100 μm thick cured material obtained by irradiation under the specified conditions, the shear storage modulus at 150°C was found to be 5.0 × 10⁻⁶ when dynamic viscoelasticity measurements were performed at a frequency of 1 Hz. ４ It is Pa or higher. A UV-curable composition for printing, characterized by the following features.

2. The ultraviolet curable composition for printing is applied onto a substrate, and without sealing the coated upper surface, in an atmospheric environment, light with a wavelength of 280 nm or more and 480 nm or less is irradiated at an irradiance of 60 mW / cm ２ , and for the cured product with a thickness of 100 μm obtained by irradiation under the condition of an irradiation dose of 900 mJ / cm ２ , after immersing in tetrahydrofuran and then filtering, the mass measured within 3 minutes after wiping off the tetrahydrofuran on the surface is W １ (g). For the cured product for which W １ is measured, after drying at 110°C for 60 minutes, the mass measured is taken as W ２ (g). When the swelling ratio represented by W １ / W ２ is 1.0 or more and 6.0 or less, the ultraviolet curable composition for printing according to claim 1.

3. The ultraviolet-curable composition for printing according to claim 1 or 2, wherein the content of the polyfunctional (meth)acrylic monomer in the ultraviolet-curable composition for printing is 3% by mass or more and 99% by mass or less.

4. The ultraviolet-curable composition for printing according to claim 3, wherein the content of the polyfunctional (meth)acrylic monomer in the ultraviolet-curable composition for printing is 6% by mass or more and 30% by mass or less.

5. The ultraviolet-curable composition for printing according to claim 1 or 2, wherein the content of the polymerizable carbon-carbon double bond-containing nitrogen compound in a total of 100 parts by mass of the ultraviolet-curable composition for printing, excluding the thermoplastic resin, is 0.5 parts by mass or more and 50 parts by mass or less.

6. The UV-curable composition for printing according to claim 1 or 2, wherein the viscosity measured at 25°C using an E-type viscometer is 0.1 mPa·s or more and 100,000 mPa·s or less.

7. This is a UV-curable composition for printing containing a monofunctional (meth)acrylic monomer, a polyfunctional (meth)acrylic monomer, a photopolymerization initiator, and a thermoplastic resin. The aforementioned UV-curable composition for printing further contains a polymerizable carbon-carbon double bond-containing nitrogen compound, The polymerizable carbon-carbon double bond-containing nitrogen compound is a compound other than a nitrogen compound having a (meth)acryloyl group. The aforementioned UV-curable composition for printing is applied to a substrate, and without sealing the coated surface, light with a wavelength of 280 nm to 480 nm is exposed to the substrate at an irradiance of 60 mW / cm² in an atmospheric environment. ２ , irradiation amount 900mJ / cm ２ The mass of a 100 μm thick cured material obtained by irradiation under the following conditions was measured within 3 minutes after immersion in tetrahydrofuran, filtration, and wiping off the tetrahydrofuran from the surface. １ (g), W １ For the cured material measured, the mass measured after drying at 110°C for 60 minutes was W. ２ When (g) is used, W １ / W ２ A UV-curable composition for printing, having a swelling ratio of 1.0 or more and 6.0 or less, and a glass transition temperature of 70°C or less.

8. The ultraviolet-curable composition for printing according to claim 7, wherein the content of the polyfunctional (meth)acrylic monomer in the ultraviolet-curable composition for printing is 1% by mass or more and 99% by mass or less.

9. The ultraviolet-curable composition for printing according to claim 8, wherein the content of the polyfunctional (meth)acrylic monomer in the ultraviolet-curable composition for printing is 3% by mass or more and 45% by mass or less.

10. The ultraviolet-curable composition for printing according to claim 7, 8, or 9, wherein the content of the polymerizable carbon-carbon double bond-containing nitrogen compound in a total of 100 parts by mass of the ultraviolet-curable composition for printing, excluding the thermoplastic resin, is 0.5 parts by mass or more and 55 parts by mass or less.

11. The ultraviolet-curable composition for printing according to claim 1, 2, 7, 8, or 9, wherein the content of the thermoplastic resin in the ultraviolet-curable composition for printing is 1% by mass or more and 60% by mass or less.

12. The ultraviolet-curable composition for printing according to claim 11, wherein the content of the thermoplastic resin in the ultraviolet-curable composition for printing is 10% by mass or more and 40% by mass or less.

13. A UV-curable printing composition according to claim 1, 2, 7, 8, or 9, used in screen printing or flexographic printing.

14. A method for manufacturing a laminate, characterized by applying the UV-curable printing composition described in claim 1, 2, 7, 8, or 9 onto a first adherend, forming an adhesive layer by exposure, and then attaching a second adherend onto the adhesive layer to produce a laminate.

15. The method for applying the UV-curable printing composition is screen printing or flexographic printing, wherein the UV-curable printing composition is partially applied to the first adherend, as described in claim 14.