JP5755419B2 - Photo-curing adhesive composition for bonding optical display or touch sensor and optical display or touch sensor bonded using the same - Google Patents

Description

  The present invention relates to a photocurable adhesive composition that can be used for bonding an optical display or a touch sensor, and an optical display or touch panel bonded using the same.

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

  Usually, protective panels and touch panels are fixed in a frame shape with the peripheral part of the case to which the optical display panel is fixed using adhesive tape, but structures fixed in this way have poor adhesion. In addition, since an air layer is formed between the optical display panel and the protective panel, and between the optical display panel and the touch panel, the display screen is difficult to see due to surface reflection, and visibility is reduced.

  Furthermore, as the thickness of the optical display panel is reduced, the substrate glass used is becoming thinner, and there is a concern that the glass is broken when the display body is dropped.

  As a method for simultaneously satisfying the prevention of visibility deterioration due to the above-mentioned surface reflection and the reinforcement of the optical display body, as a method replacing the above-described technology using the adhesive tape having the problem of adhesiveness and bubbles, a technology using a liquid resin is used. Attention has been gathered.

  However, the glass of optical display panels used for bonding with protective panels or touch panels is becoming thinner due to the need for thinner and lighter display devices, and liquid resin cures with technology using liquid resin. The glass may be damaged or deformed due to the curing shrinkage stress during the process. In the case where the optical display panel is a liquid crystal panel, the cell gap of the liquid crystal fluctuates due to the curing shrinkage stress and causes a display defect. Therefore, a resin having a reduced curing shrinkage rate and elastic modulus is used (Patent Document 1). .

  In addition, when the protective panel is an optical functional material such as an acrylic plate or a polycarbonate plate, heat and moisture resistance tests can be performed due to differences in linear expansion between glass and acrylic, and distortion during molding of plastic molding materials such as acrylic plates and polycarbonate. In this case, molding distortion is alleviated and moisture absorption / drying occurs, and surface accuracy changes such as dimensional changes and warping occur. The change in dimensions and the change in surface accuracy cause breakage of the glass and display failure of the LCD. Therefore, the resin has a flexible and sufficient elongation rate to alleviate the deformation of the protective panel.

  As a result of pursuing flexibility, the conventional liquid resin corresponding to the above problems requires a high integrated light amount to obtain sufficient adhesive strength, and tact at the time of module manufacture has been a problem.

  As a general method for increasing the tact, (1) a method using a polyfunctional acrylate monomer, and (2) a ketone and an amine curing accelerator such as an alkyl ester of dimethylaminobenzoic acid, triethanolamine or methyldiethanolamine are used. There was a method (Non-patent Document 1) to be used in combination.

WO2010 / 027041 pamphlet

Optical Application Technology / Material Dictionary, page 104, line 5, edited by Optical Application Technology / Material Dictionary Committee, published in 2006

  The present inventors (1) In the method using a polyfunctional acrylate monomer, since the elastic modulus and shrinkage rate of the cured product are increased, the curing shrinkage stress is increased, and glass breakage and display unevenness of the display are generated. It has been found that (2) the method of using a ketone and an amine curing accelerator in combination causes problems such as coloring after the heat resistance test, discoloration, and strength reduction after the moisture resistance test.

  Accordingly, an object of the present invention is to provide a photocurable adhesive composition that can exhibit strength with a low integrated light quantity and suppresses discoloration and a decrease in strength after a moisture resistance test while suppressing an increase in cure shrinkage and elastic modulus.

  The present inventors have found that the above problems can be achieved by using a hindered amine as a curing agent in a specific photocurable adhesive composition, and have completed the present invention.

  1st this invention contains 1 or more types of (meth) acrylate oligomer chosen from the group which consists of a polyisoprene (meth) acrylate oligomer, a polybutadiene (meth) acrylate oligomer, and a polyurethane (meth) acrylate oligomer, and a hindered amine. It is a photocurable adhesive composition.

  2nd this invention is an optical display body or a touch sensor bonded together by said photocurable adhesive composition.

  The third aspect of the present invention is a photocurable type containing at least one (meth) acrylate oligomer selected from the group consisting of a polyisoprene (meth) acrylate oligomer, a polybutadiene (meth) acrylate oligomer, and a polyurethane (meth) acrylate oligomer. A method for improving the curability of the adhesive composition, wherein a hindered amine is added to the photocurable adhesive composition.

  4th this invention is a photocurable type | mold containing 1 or more types of (meth) acrylate oligomer chosen from the group which consists of a polyisoprene (meth) acrylate oligomer, a polybutadiene (meth) acrylate oligomer, and a polyurethane (meth) acrylate oligomer. A method for improving coloring of an adhesive composition due to heat, wherein a hindered amine is added to the photocurable adhesive composition.

  According to the first and second aspects of the present invention, the photo-curing type is capable of exhibiting strength with a low integrated light quantity, and suppressing coloring and discoloration due to heat and a decrease in strength after a moisture resistance test while suppressing an increase in curing shrinkage rate and elastic modulus. A resin composition and an optical display or a touch sensor bonded using the resin composition can be provided.

  According to the 3rd and 4th this invention, the sclerosis | hardenability of the photocurable adhesive composition containing a (meth) acrylate oligomer and coloring by a heat | fever can be improved.

  The photocurable adhesive composition of the present invention comprises at least one (meth) acrylate oligomer and a hindered amine selected from the group consisting of a polyisoprene (meth) acrylate oligomer, a polybutadiene (meth) acrylate oligomer, and a polyurethane (meth) acrylate oligomer. Is a photocurable adhesive composition containing:

The photocurable adhesive composition of the present invention includes one or more (meth) acrylate oligomers selected from the group consisting of polyisoprene (meth) acrylate oligomers, polybutadiene (meth) acrylate oligomers, and polyurethane (meth) acrylate oligomers. .
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 commercial item, there exists "UC-1" (molecular weight 25000) made from Kuraray, for example.

  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.

  The photocurable adhesive composition of the present invention contains a hindered amine. Any conventionally known hindered amine can be used.

  As the hindered amine, for example, a compound represented by the structure of the following formula is preferable.

（式中、Ｒ⁵は水素原子、炭素原子数１〜１２の直鎖若しくは分岐のアルキル基、又は、炭素原子数１〜１２の直鎖若しくは分岐のアルコキシ基を表し、Ｒ⁶はカーボネート基、又は、１〜４価の有機カルボン酸のカルボキシル基から水素原子を除いた残基を表し、ｎは１〜４の整数を表す。）

(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, it represents a residue obtained by removing a hydrogen atom from a carboxyl group of a monovalent to tetravalent organic carboxylic acid, and n represents an integer of 1 to 4.)

  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.

  In the photocurable adhesive composition of the present invention, the hindered amine is preferably 0.01 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, most preferably 100 parts by mass of the (meth) acrylate oligomer. Contains 0.1 to 3 parts by mass.

  The photocurable adhesive composition of the present invention can further contain one or more components selected from the group consisting of (meth) acrylate monomers and plasticizers. The photocurable adhesive composition of the present invention can impart elongation to a cured product by including a (meth) acrylate monomer. The photocurable adhesive composition of the present invention is elastic by including a plasticizer. The rate can be controlled.

  (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, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, ethylene Glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, hydroxyethyl (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, dicyclopentenyloxyethyl (meth) acrylate, norbornene (meth) acrylate Can be illustrated. These (meth) acrylate phenoxyethyl (meth) acrylate (PO), phenoxy polyethylene glycol (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, cyclohexyl (meth) acrylate (CH), nonylphenol EO adduct It is selected from (meth) acrylate, methoxytriethylene glycol (meth) acrylate and tetrahydrofurfuryl (meth) acrylate. These (meth) acrylate monomers can be used alone or in combination of two or more.

  The (meth) acrylate monomer is contained in an amount of preferably 300 parts by mass or less, more preferably 150 parts by mass or less, and most preferably 120 parts by mass or less with respect to 100 parts by mass of the (meth) acrylate oligomer.

  Examples of the plasticizer include polymers compatible with (meth) acrylate oligomers, oligomers, phthalates, castor oils, and the like. Examples of the oligomer or polymer include polyisoprene-based, polybutadiene-based, and xylene-based oligomers or polymers. These softening ingredients are commercially available from Kuraray as the LIR series and from Degussa as the polyoil series. One or more kinds of these softening components can be used.

  The plasticizer is preferably contained in an amount of 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 of the (meth) acrylate oligomer.

  The photocurable adhesive composition of the present invention may further contain a photoinitiator. As the photoinitiator, a common initiator can be used, for example, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 1-hydroxy Sea cyclohexyl phenyl ketone, benzophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine 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, benzoin ester 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, ethyl anthraquinone, benzophenone ammonium salt, thioxanthone ammonium salt, bis (2,6-di) Toxibenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzophenone, 4-methyl Benzophenone, 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′-biimidazole, 2 -Benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoyldiphenyl ether, acrylated benzofe Non, 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 photopolymerization initiator, acridine photopolymerization initiator, triazine photopolymerization initiator, benzoyl photopolymerization initiation An agent etc. can be illustrated. One or more of these photoinitiators can be used.

  The amount of the photoinitiator is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and further preferably 1 to 15 parts by mass with respect to 100 parts by mass of the (meth) acrylate oligomer.

  In the present invention, preferred photoinitiators include 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide and 1-hydroxycyclohexylphenylphenyl ketone, which may be used alone or in combination. Good.

  The photocurable adhesive composition of the present invention can further contain an adhesion-imparting agent. 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. The amount of the adhesion-imparting agent is preferably 10 parts by mass or less, more preferably 1 part by mass or less with respect to 100 parts by mass of the (meth) acrylate oligomer.

  The photocurable adhesive composition of the present invention can further contain an antioxidant. 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. The amount of the antioxidant is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass of the (meth) acrylate oligomer.

  When the light curable adhesive composition of the present invention is not exposed to a part of the adhesive composition applied to the adhesive surface due to the structure of the material to be adhered, the light irradiates it with light and cures the light. Where it does not hit, it can be an adhesive 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. One type or two or more types of these organic oxides can be used, and the amount thereof is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 100 parts by mass with respect to 100 parts by mass of the (meth) acrylate oligomer. 3 parts by mass. Naphthenic acid metal complexes, dimethylaniline, quaternary ammonium salts, and phosphates can be used as the above-mentioned organic peroxide curing accelerator.

  The photocurable adhesive composition of the present invention can be used as an adhesive in an optical display or a touch sensor. For example, bonding of an optical display panel and a touch panel, bonding of an optical display panel and a protection panel, bonding of a touch panel and a protection panel, bonding of an optical display panel and an optical display panel, optical display panel and parallax barrier And can be used for bonding. Bonding can be performed by a normal method.

  The present invention also relates to an optical display or a touch sensor bonded together with the photocurable adhesive composition. These bonded bodies can be incorporated into electronic devices such as televisions, digital cameras, mobile phones, personal computers, monitors, and televisions.

  The present invention relates to a photocurable adhesive composition containing one or more (meth) acrylate oligomers selected from the group consisting of polyisoprene (meth) acrylate oligomers, polybutadiene (meth) acrylate oligomers, and polyurethane (meth) acrylate oligomers. It is also related to a method for improving the curability of the composition, wherein a hindered amine is added to the photocurable adhesive composition.

  Furthermore, the present invention provides a photocurable adhesive containing at least one (meth) acrylate oligomer selected from the group consisting of a polyisoprene (meth) acrylate oligomer, a polybutadiene (meth) acrylate oligomer, and a polyurethane (meth) acrylate oligomer. It is also related to a method for improving the coloration of the composition by heat, characterized in that a hindered amine is added to the photocurable adhesive composition.

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

(Examples 1-7 and Comparative Examples 1-4)
The components shown in Table 1 were blended in the amounts (mass basis) shown in Table 1 to obtain photocurable adhesive compositions of Examples 1 to 7 and Comparative Examples 1 to 4.

UC-1: Polyisoprene methacrylate oligomer (molecular weight 25000)
UT4462: Polyurethane acrylate (molecular weight 2000)
UA-1: Polyurethane methacrylate oligomer (molecular weight 2400)
TE-2000: Polybutadiene methacrylate oligomer (molecular weight 2000)
QM657: dicyclopentenyloxyethyl methacrylate HOB: 2-hydroxybutyl methacrylate HO: 2-hydroxyethyl methacrylate BZ: benzyl methacrylate IB: isobornyl methacrylate RM1002: isobornyl methacrylate LA: lauryl acrylate Polyoil 110: liquid polybutadiene L-LIR : Liquid polyisoprene BF-1000: epoxidized polybutadiene Lucillin TPO: 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide Benzoylphenylphosphine oxide TZT: Trimethylbenzophenone and monomethylbenzo Phenone mixture Karenz PE-01: Pentaerythritol tetrakis (3-mercaptobutyrate)
Tinuvin 123: bis [1- (octyloxy) -2,2,6,6-tetramethyl-4-piperidinyl] sebacate

(Test Example 1)
(1. Measurement of adhesive strength)
A test piece for measuring adhesive strength was prepared as follows. A sample was bonded to glass / glass with a bonding area of 5 mm and a bonding thickness of 0.3 mm, and UV-cured.

  The adhesive strength was measured as follows. One glass bonded to the cross was fixed, the other glass was pulled at a tensile test speed of 5 mm / min, and the maximum value when the glass bonded to the cross was peeled was defined as the adhesive strength.

(2. Measurement of cure shrinkage, elastic modulus and elongation)
The cure shrinkage was measured by JIS K6833 specific gravity cup method.
The elastic modulus and elongation rate are JIS Z1702 No. Three dumbbell test pieces (thickness 1 mm) were measured at a speed of 10 m / min using an autograph manufactured by Shimadzu Corporation. The dumbbell specimen was cured using a diffusion metal halide lamp with a conveyor. The amount of light was measured at a wavelength of 350 nm (Oak illuminometer).

(Measurement of appearance after 3.80 ° C. and 100 hours)
A test piece for measuring the appearance after 100 hours at 80 ° C. was prepared as follows. A sample thickness of 0.3 mm was set, and UV curing was performed by sandwiching the glass.

  The measurement of the appearance after 80 hours at 80 ° C. was performed by visually checking the appearance after the test piece was left at 80 ° C. for 100 hours.

  The adhesive strength after 65 hours at 95 ° C. for 100 hours (after the moisture resistance test) was measured by the following method.

  The test piece prepared by the method described in paragraph 0050 was allowed to stand at 65 ° C. and 95% for 100 hours, and then measured by the measurement method described in paragraph 0051.

  Table 2 shows the measurement results of the adhesive strength, cure shrinkage rate, elastic modulus and elongation rate, and the appearance after 100 hours at 80 ° C. From Table 2, compared to the corresponding comparative examples, the examples can suppress the increase in curing shrinkage rate and elastic modulus while obtaining the same adhesive strength with a lower amount of light, the strength decrease after the moisture resistance test is suppressed, and the curability. It can be seen that is improved.

(Examples 8 to 16 and Comparative Example 5)
The components shown in Table 3 were blended in the amounts (mass basis) shown in Table 3 to obtain the photocurable adhesive compositions of Examples 8 to 16 and Comparative Example 5.

Tinuvin 144: bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-butylmalonate
LA-62: 1,2,2,6,6-pentamethyl-4-piperidyl and tridecyl-1,2,3,4-butanetetracarboxylate
FA-711MM: Pentamethylpiperidyl methacrylate FA-711H: 2,2,6,6-tetramethyl-4-piperidyl methacrylate

  Table 4 shows the measurement results of the adhesive strength, elastic modulus and elongation rate, and appearance after 80 hours at 100C. From Table 4, it can be seen that the Examples are extremely less colored by heat than the Comparative Examples.

  The present invention can develop strength with a low integrated light quantity, and can suppress the discoloration due to heat and the decrease in strength after the moisture resistance test while suppressing the increase in curing shrinkage rate and elastic modulus. Available to:

Claims (5)

And one or more oligomers selected from polyisoprene (meth) acrylate oligomer and polybutadiene (meth) acrylate oligomer chromatography or Ranaru group containing a 2,2,6,6-tetramethyl-4-piperidyl methacrylate, For bonding optical display panel and touch panel, for bonding optical display panel and protective panel, for bonding touch panel and protective panel, for bonding optical display panel and optical display panel, or optical display panel A photo-curing adhesive composition for bonding to a parallax barrier.   The photocurable adhesive composition according to claim 1, further comprising one or more components selected from the group consisting of (meth) acrylate monomers and plasticizers.   The optical display body or touch sensor bonded together with the photocurable adhesive composition of Claim 1 or 2. Containing polyisoprene (meth) acrylate oligomer and polybutadiene (meth) one or more oligomers selected from acrylate oligomer chromatography or Ranaru group, for bonding the optical display panel and the touch panel, an optical display panel and protective panel Of a photocurable adhesive composition for laminating, for laminating a touch panel and a protective panel, for laminating an optical display panel and an optical display panel, or for laminating an optical display panel and a parallax barrier A method for improving curability, the method comprising adding 2,2,6,6-tetramethyl-4-piperidyl methacrylate to the photocurable adhesive composition. Containing polyisoprene (meth) acrylate oligomer and polybutadiene (meth) one or more oligomers selected from acrylate oligomer chromatography or Ranaru group, for bonding the optical display panel and the touch panel, an optical display panel and protective panel Of a photocurable adhesive composition for laminating, for laminating a touch panel and a protective panel, for laminating an optical display panel and an optical display panel, or for laminating an optical display panel and a parallax barrier A method for improving coloring, characterized in that 2,2,6,6-tetramethyl-4-piperidyl methacrylate is added to the photocurable adhesive composition.