JP2013203843A - Photocurable resin composition for laminating decoratively printed front plate and optical display panel or touch panel, and optical display or touch sensor made by laminating using the resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable resin composition mitigating the problem that: when a decoratively printed front plate and an optical display panel or touch panel are laminated with each other, a relevant decoratively printing ink is discolored.SOLUTION: The photocurable resin composition for laminating a decorative printed front plate and a touch panel or optical display panel with each other is provided, comprising a photopolymerizable oligomer, photopolymerizable monomer and photopolymerization initiator; wherein, it is characterized in that: the content of a hydroxyl-containing photopolymerizable monomer is 5.5 mass% or less.

Description

  The present invention relates to a photocurable resin composition used for bonding a decorative front plate and an optical display panel or a touch panel, and an optical display or touch sensor bonded using the same. About.

  Since optical display panels such as LCDs use a thin glass substrate, a front plate is installed on the front of the display panel when a front plate is installed for the purpose of protecting the glass substrate or when applications are expanded. In addition to this, a touch panel is often installed.

  Adhesive tape technology was used to attach the front plate, optical display panel, and touch panel. However, because there are problems with adhesiveness and bubbles, liquid resin is used as an alternative to the adhesive tape technology. Technology has been developed (Patent Document 1).

WO2010 / 027041 pamphlet

  The inventors of the present invention have a problem that when a front plate on which decorative printing is performed and an optical display panel or a touch panel are bonded together using a liquid resin of the prior art, the color of the ink for decorative printing changes. I found out.

  Accordingly, an object of the present invention is to provide a photocurable resin that improves the problem of discoloration of decorative printing ink when a front plate on which decorative printing has been performed and an optical display panel or a touch panel are bonded together. It is to provide a composition.

  In the photocurable resin composition containing a photopolymerizable oligomer, a photopolymerizable monomer and a photopolymerization initiator, the present inventors adjust the content of the hydroxyl group-containing photopolymerizable monomer in the composition, As a result, the following problems were solved.

  1st this invention is a photocurable resin composition for bonding with the front board by which decorative printing was performed, and a touchscreen or an optical display panel, Comprising: A photopolymerizable oligomer, a photopolymerizable monomer, and light A photocurable resin composition comprising a polymerization initiator and having a hydroxyl group-containing photopolymerizable monomer content of 5.5% by mass or less in the photocurable resin composition.

  2nd this invention is said 1st photocurable resin composition which contains a plasticizer further.

  In the third aspect of the present invention, the photopolymerizable oligomer is one or more kinds of oligomers selected from the group consisting of polyisoprene (meth) acrylate oligomers, polybutadiene (meth) acrylate oligomers, and polyurethane (meth) acrylate oligomers. It is the 1st or 2nd photocurable resin composition.

  The fourth aspect of the present invention is the photocurable resin composition according to any one of the first to third aspects, wherein the photopolymerizable monomer is one or more monomers selected from the group consisting of (meth) acrylate monomers. is there.

  According to a fifth aspect of the present invention, there is provided an optical display body comprising a front plate on which decorative printing has been performed and a touch panel or an optical display panel, which are bonded to each other by any one of the first to fourth photocurable resin compositions. Or it is a touch sensor.

  According to the present invention, the front plate on which decorative printing has been performed and the touch panel or the optical display panel can be bonded together without changing the color of the decorative printing ink.

FIG. 1a is a diagram showing a method for testing the discoloration of ink for decorative printing on a front plate subjected to decorative printing by a photocurable resin composition as a model. A photocurable resin composition is applied to the decorative printing surface of the glass plate (1) subjected to the decorative printing (2), and another glass plate (4) is disposed on the application surface, so that the photocurable resin is applied. Observe the discoloration of the ink in the applied part of the composition. FIG. 1b shows the case where there is a color change, and FIG. 1c shows the case where there is no color change.

  The photocurable resin composition of the present invention is a photocurable resin composition for bonding a front plate on which decorative printing has been performed and a touch panel or an optical display panel.

The front plate on which decorative printing has been performed may include any front plate decorated with printing ink. The printing ink can be any ink, for example, polyvinyl chloride resin, polyamide resin, polyester resin, polyacrylic resin, polyurethane resin, polyvinyl acetal resin, polyester urethane resin, cellulose ester. Examples thereof include colored inks that contain a resin such as a base resin or an alkyd resin as a binder and a pigment or dye of an appropriate color as a colorant. As a method for forming decorative printing, a normal printing method such as an offset printing method, a gravure printing method, a screen printing method, or the like can be used. A suitable ink is “GLS-HF” manufactured by Teikoku Ink.
The touch panel and the optical display panel can be any touch panel and optical display panel.

  The photocurable resin composition of the present invention is an adhesive for bonding a front plate and a touch panel or an optical display panel through a decorative printing surface of the front plate.

The photocurable resin composition of the present invention contains a photopolymerizable oligomer, a photopolymerizable monomer and a photopolymerization initiator, and the content of the hydroxyl group-containing photopolymerizable monomer in the photocurable resin composition is 5.5 mass. % Or less.

<Photopolymerizable oligomer>
The photopolymerizable oligomer is not particularly limited as long as it is a photopolymerizable oligomer, but one or more selected from the group consisting of a polyisoprene (meth) acrylate oligomer, a polybutadiene (meth) acrylate oligomer, and a polyurethane (meth) acrylate oligomer. (Meth) acrylate oligomers are preferred.

  The polyisoprene (meth) acrylate oligomer is also called (meth) acryl-modified polyisoprene, and preferably has a molecular weight of 1000 to 100,000, more preferably 100,000 to 50,000. As a commercially available product, for example, “UC-203” (molecular weight 36000) manufactured by Kuraray Co., Ltd. is available.

  The polybutadiene (meth) acrylate oligomer is also called (meth) acryl-modified polybutadiene, and preferably has a molecular weight of 500 to 100,000, more preferably 1,000 to 30,000. An example of a commercially available product is “TE2000” (molecular weight 2000) manufactured by Nippon Oil Corporation.

  The polyurethane (meth) acrylate oligomer is also called (meth) acryl-modified polyurethane and preferably has a molecular weight of 1000 to 100,000, more preferably 10,000 to 50,000. As a commercial item, there exists "UA-1" by a light chemical company, for example.

  As the (meth) acrylate oligomer, a polyisoprene (meth) acrylate oligomer is particularly preferable.

<Photopolymerizable monomer>
The photopolymerizable monomer is not particularly limited as long as it is a photopolymerizable monomer, but is preferably a (meth) acrylate monomer.

  (Meth) acrylate monomers include, for example, 2-ethylhexyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, lauryl (meth) acrylate, alkyl (meth) ) Acrylate, methoxyethyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,3- Butylene glycol di (meth) acrylate, 1,4-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, dicyclo Integrators sulfonyloxy ethyl (meth) acrylate, a norbornene (meth) acrylate can be exemplified. These (meth) acrylates phenoxyethyl (meth) acrylate (PO), phenoxypolyethylene glycol (meth) acrylate, cyclohexyl (meth) acrylate (CH), nonylphenol EO adduct (meth) acrylate, methoxytriethylene glycol (meth) acrylate Tetrahydrofurfuryl (meth) acrylate can also be used. These (meth) acrylate monomers can be used alone or in combination of two or more.

  The photopolymerizable monomer is preferably contained in an amount of 30 to 300 parts by mass, more preferably 50 to 150 parts by mass, and most preferably 70 to 120 parts by mass with respect to 100 parts by mass of the photopolymerizable oligomer.

<Photopolymerization initiator>
As the photopolymerization initiator, a general photopolymerization initiator can be used, for example, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 1-hydroxy-cyclohexyl ruphenyl-ketone, benzophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenyl Ethoxyphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1- [ 4-methylthio] phenyl] -2-morpholinopropan-1-one, benzoin methyl ether, Zoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer, 2-hydroxy-2-methyl-1-phenyl-1-propanone, isopropylthioxanthone, methyl o-benzoylbenzoate, [ 4- (methylphenylthio) phenyl] phenylmethane, 2,4-diethylthioxanthone, 2-chlorothioxanthone, benzophenone, ethylanthraquinone, benzophenone ammonium salt, thioxanthone ammonium salt, bis ( , 6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, 4,4′-bisdiethylaminobenzophenone, 1,4 dibenzoylbenzene, 10-butyl-2-chloroacridone, 2,2′bis (o-chlorophenyl) 4,5,4 ′, 5 ′ -Tetrakis (3,4,5-trimethoxyphenyl) 1,2'-biimidazole, 2,2'bis (o-chlorophenyl) 4,5,4 ', 5'-tetraphenyl-1,2'-bi Imidazole, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoyldiphenyl ether, acrylated benzopheno Bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium, o-methylbenzoylbenzoate, p- Dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl ethyl ester, active tertiary amine, carbazole / phenone photoinitiator, acridine photoinitiator, triazine photoinitiator, benzoyl photoinitiator An agent etc. can be illustrated. One kind or two or more kinds of these photopolymerization initiators can be used.

  In the present invention, preferred photopolymerization initiators include 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide and 1-hydroxycyclohexylphenylphenyl ketone, and each may be used alone or in combination. Also good.

  The amount of the photopolymerization initiator is preferably 0.1 to 50 parts by mass or less, more preferably 0.5 to 40 parts by mass or less, with respect to 100 parts by mass in total of the photopolymerizable oligomer and the photopolymerizable monomer. Preferably it is 1-20 mass parts.

<Hydroxyl-containing photopolymerizable monomer>
In the photocurable resin composition of the present invention, the content of the hydroxyl group-containing photopolymerizable monomer in the photocurable resin composition is 5.5% by mass or less. The content of the hydroxyl group-containing photopolymerizable monomer is preferably 4.0% by mass or less, more preferably 3.0% by mass or less.

  The hydroxyl group-containing photopolymerizable monomer means any monomer having a hydroxyl group and having photopolymerizability. Examples of the hydroxyl group-containing photopolymerizable monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like. .

<Plasticizer>
The photocurable resin composition of the present invention can further contain a plasticizer. The photocurable adhesive composition of this invention can control the elasticity modulus by including a plasticizer.

  Examples of the plasticizer include polymers that are compatible with the photopolymerizable oligomer, oligomers, phthalates, and castor oils. Examples of the oligomer or polymer include polyisoprene-based, polybutadiene-based, and xylene-based oligomers or polymers. These plasticizers are commercially available from Kuraray as the LIR series and from Degussa as the polyoil series. These plasticizers can be used alone or in combination of two or more.

  The plasticizer is preferably 500 parts by mass or less, more preferably 300 parts by mass or less, and still more preferably 250 parts by mass or less with respect to 100 parts by mass in total of the photopolymerizable oligomer and the photopolymerizable monomer.

<Other ingredients>
The photocurable resin composition of the present invention can further contain conventional additives such as hindered amines, adhesion-imparting agents, and antioxidants.

As a hindered amine, for example, the structure of the following formula:

(Wherein R ⁵ represents a hydrogen atom, a linear or branched alkyl group having 1 to 12 carbon atoms, or a linear or branched alkoxy group having 1 to 12 carbon atoms, R ⁶ represents a carbonate group, Or the compound which represents the residue remove | excluding the hydrogen atom from the carboxyl group of 1-4 valent organic carboxylic acid, and n represents the integer of 1-4 is mentioned.

  As a commercial product of hindered amine, tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate (manufactured by ADEKA, trade name ADK STAB LA-52), Tetrakis (1,2,2,6,6-pentamethyl-4-piperidyl) butane-1,2,3,4-butanetetracarboxylate (manufactured by ADEKA, trade name ADK STAB LA-57), 1,2,2 , 6,6-pentamethyl-4-piperidyl, and tridecyl-1,2,3,4-butanetetracarboxylate (manufactured by ADEKA, trade name Adeka Stab LA-62), 2,2,6,6-tetramethyl- A condensate of piperidinol, tridecyl alcohol and 1,2,3,4-butanetetracarboxylic acid (trade name Adekasta, manufactured by ADEKA) LA-67), 1,2,3,4-butanetetracarboxylic acid and 2,2,6,6-tetramethyl-4-piperidinol and β, β, β, β-tetramethyl-3,9- (2 , 4,8,10-tetraoxaspiro [5,5] undecane) -diethanol condensate (product of ADEKA, trade name ADK STAB LA-68LD), decanedioic acid bis (2,2,6,6-tetra Methyl-4-piperidyl) (manufactured by ADEKA, trade name ADK STAB LA-77Y, Ciba Specialty Chemicals, trade name TINUVIN 123), 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate (ADEKA) Product name ADK STAB LA-82, manufactured by Hitachi Chemical Co., Ltd., product name FA-711MM), 2,2,6,6-tetramethyl-4-piperidyl methacrylate (AD KA, trade name ADK STAB LA-87, Hitachi Chemical Co., Ltd., trade name FA-712HM), high molecular weight hindered amine light stabilizer (Ciba Specialty Chemicals, trade name CHIMASSORB 119FL, CHIMASSORB 2020FDL), poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) Imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (Ciba Specialty Chemicals, trade name CHIMASSORB 944FDL), polymer sterically hindered amine derivative (Ciba Specialty)・ Product made by Chemicals, trade name TINUVIN 622LD), 2- (3,5-di-t-butyl) -4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl) (manufactured by Ciba Specialty Chemicals, trade name TINUVIN 144), bis (1, 2,2,6,6-pentamethyl-4-piperidinyl) sebacate (trade name TINUVIN 765, manufactured by Ciba Specialty Chemicals), bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (Ciba -Specialty Chemicals make, brand name TINUVIN 770) etc. can be obtained.

  Silane coupling agents such as vinyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldisilane as adhesion promoters Ethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3- Methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxy Lan, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl- Butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropyl, methyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, Examples thereof include bis (triethoxysilylpropyl) tetrasulfide and 3-isocyanatopropyltriethoxysilane. One kind or two or more kinds of these adhesion-imparting agents can be used.

  Antioxidants include BHT, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, pentaerythrityl. Tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) Propionate], triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-t- Butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethyle Bis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4- Hydroxybenzyl) benzene, tris- (3,5-di-t-butyl-4-hydroxybenzyl) -isocyanurate, octylated diphenylamine, 2,4, -bis [(octylthio) methyl] -O-cresol, isooctyl- Examples include 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate and dibutylhydroxytoluene. These antioxidants can be used alone or in combination of two or more.

  When the light curable resin composition of the present invention is not exposed to a part of the adhesive composition applied to the adhesion surface due to the structure of the material to be adhered, the light is cured by the light and the light is cured. Where it does not hit, it can be made into a resin composition of a combination type of photocuring and thermosetting, in which an organic peroxide is added and cured by heat. Examples of organic peroxides include ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, and peroxydicarbonates. One type or two or more types of these organic oxides can be used. These organic oxides can be used alone or in combination of two or more, and the amount is preferably from 0.1 to 10 parts by mass, more preferably from 100 to 10 parts by mass, based on 100 parts by mass of the photopolymerizable oligomer and photopolymerizable monomer. Preferably it is 0.5-5 mass parts. Naphthenic acid metal complexes, dimethylaniline, quaternary ammonium salts, and phosphates can be used as the above-mentioned organic peroxide curing accelerator.

  The photocurable resin composition of the present invention can be used as an adhesive in an optical display or a touch sensor. For example, an optical display body or a touch sensor can be manufactured by using it for bonding a front plate on which decorative printing has been performed and an optical display panel or a touch panel via a decorative printing surface. Bonding can be performed by a normal method.

  The present invention includes an optical display body including a front plate and an optical display panel that have been subjected to decorative printing, or a front plate and a touch panel that have been subjected to decorative printing, which are bonded together with the above-described photocurable resin composition. Also related to touch sensors. These optical display bodies and touch panels can be incorporated into electronic devices such as televisions, digital cameras, mobile phones, personal computers, monitors, and televisions.

  The present invention is illustrated by the following examples, but the present invention is not limited to these examples.

(Examples 1-8 and Comparative Examples 1-2)
The components shown in Tables 1 to 3 were blended in the amounts (mass basis) shown in Tables 1 to 3 to obtain photocurable resin compositions of Examples 1 to 8 and Comparative Examples 1 and 2.

FA-711MM: Pentamethylpiperidyl methacrylate HOP: 2-hydroxypropyl methacrylate I-184: 1-hydroxy-cyclohexylphenyl-ketone UC-203: Polyisoprene methacrylate oligomer L-LIR: Liquid polyisoprene Poly oil 110: Liquid Polybutadiene

HOB: 2-hydroxybutyl methacrylate QM-657: dicyclopentenyloxyethyl methacrylate

(Test example) Discoloration of ink for decorative printing Test method: Examples 1 to 8 and Examples 1 to 8 on the ink surface of a glass plate on which the entire surface of one side was printed with ink ("GLS-HF" manufactured by Teikoku Ink) One drop of each photocurable resin composition of Comparative Examples 1 and 2 was applied, and another glass plate having the same size was disposed on the application surface (see FIG. 1a). After 12 hours of arrangement, the discolored state of the ink was visually observed from the direction shown in FIG. 1a. If there is a color difference between the part where the photocurable resin composition is applied and the other part as shown in FIG. 1b, the color is changed, and the part where the photocurable resin composition is applied as shown in FIG. 1c. If there was no color difference in other parts, “no discoloration” was set.
Test results: Tables 1 to 3 show the results of the discoloration test of the decorative printing ink.

  According to the present invention, the front plate on which decorative printing has been performed and the touch panel or the optical display panel can be bonded to each other without changing the color of the decorative printing ink. Useful for bonding touch sensors.

1: Glass plate 2: Decorative printing 3: Photocurable resin composition 4: Glass plate

Claims (5)

  A photocurable resin composition for bonding a decorative printed front plate to a touch panel or an optical display panel, comprising a photopolymerizable oligomer, a photopolymerizable monomer and a photopolymerization initiator, The photocurable resin composition, wherein the content of the hydroxyl group-containing photopolymerizable monomer in the photocurable resin composition is 5.5% by mass or less.   Furthermore, the photocurable resin composition of Claim 1 containing a plasticizer.   The light according to claim 1 or 2, wherein the photopolymerizable oligomer is at least one oligomer selected from the group consisting of a polyisoprene (meth) acrylate oligomer, a polybutadiene (meth) acrylate oligomer, and a polyurethane (meth) acrylate oligomer. A curable resin composition.   The photocurable resin composition according to any one of claims 1 to 3, wherein the photopolymerizable monomer is at least one monomer selected from the group consisting of (meth) acrylate monomers.   The optical display body or touch sensor by which the front board by which decorative printing was given, and the touch panel or the optical display panel were bonded together by the photocurable resin composition of any one of Claims 1-4.