JP5978500B2 - Active energy ray curable resin composition for void filling - Google Patents

Description

  The present invention relates to an active energy ray-curable void filling resin composition and an image display device produced using the resin composition.

2. Description of the Related Art Liquid crystal displays (hereinafter referred to as “LCD”) and organic EL (OLED) are widely used as image display devices used in mobile devices such as mobile phones, smartphones, and portable game machines.
In recent years, in these image display devices for mobile devices, the refractive index of these members is a gap between the surface protective layer or the touch panel and the display surface of the image display unit, or between the surface protective layer and the touch panel. There has been proposed a method of improving the brightness and contrast of an image display apparatus by suppressing the reflection of light by filling a transparent material close to the above, thereby improving the transparency. Examples of the transparent material include a transparent resin sheet, a reaction curable liquid resin, and an adhesive.

  Patent Document 1 has a viscosity that does not swell and dissolve the transparent resin sheet and one or both of the liquid crystal display panel and the transparent protective plate through the transparent resin sheet made of a plasticizer-containing acrylic polymer. A method of manufacturing an LCD is disclosed in which a viewing side of a liquid crystal display panel and a transparent protective plate are brought into close contact with each other in a state where a volatile liquid of 10 cp or less is provided, and then dried under heating and pressing.

  Patent Document 2 fixes a liquid crystal display element and a glass plate by injecting a reaction-curable silicone gel, which is a colorless and transparent elastic resin, between the liquid crystal display element and the glass plate in a liquid state and then curing the gel. An LCD manufacturing method is disclosed.

  Patent Document 3 discloses an LCD in which a transparent material is filled between a liquid crystal display element and a protective plate. As the transparent material, a material in which an unsaturated polyester is dissolved in a polymerizable monomer is used, which is solidified after being injected into a gap between the liquid crystal display element and the protective plate.

  Patent Document 4 discloses a pressure-sensitive adhesive composition for an optical member containing a (meth) acrylic polymer obtained by copolymerizing an alkyl (meth) acrylate and a hydroxyl group-containing (meth) acrylate at a specific ratio, and a peroxide. .

JP 09-197387 A Japanese Patent Laid-Open No. 06-59253 Japanese Patent Laid-Open No. 03-204616 JP 2007-31506 A

As described above, transparent resin sheets, reactive curable liquid resins, adhesives, and the like have been proposed as transparent materials for filling voids used in image display devices.
However, since the transparent resin sheet has a higher elastic modulus than the liquid resin and the pressure-sensitive adhesive, there is a problem that the gap filling property is poor.
In addition, the reaction curable liquid resin becomes a process for handling a liquid, and the manufacturing process becomes complicated. Further, the silicone gel has a low adhesive force and has a problem in reliability.

On the other hand, since the adhesive is easy to handle, has a high yield, and has high reliability, it is suitable for a structure in which the image display device and the surface protective layer are directly bonded.
However, the surface protective layer in the image display device has a concavo-convex shape such as a light-shielding layer, and when sticking an adhesive to the concavo-convex shape surface, or adheres to the display surface of an image display unit provided with a concavo-convex layer. When pasting the agent, even if the uneven shape is filled without gaps, even if it is left for a long time under high temperature and high humidity conditions, air bubbles are generated at the surface protective layer, the display surface of the image display unit, or the interface with the touch panel module. It is necessary that no peeling occurs and no whitening occurs. In recent years, the uneven film thickness tends to increase from the viewpoint of design, and the demand for gap filling properties and reliability is increasing, and there is a need for void filling resins that solve this problem.

  The present inventors have excellent void filling properties, curability and adhesiveness, and in particular, UV curability and adhesiveness when the surface protective layer, image display unit or touch panel module of an image display device is attached to each other and laminated. In order to find an active energy ray-curable void-filling resin composition that excels in the process, the inventors have intensively studied.

  As a result of intensive studies to achieve the above object, the inventors of the present invention continuously (A) an ethylenically unsaturated group-containing compound and (B) a vinyl monomer at a copolymerization temperature of 150 to 350 ° C. A composition containing a copolymer having a weight average molecular weight of 1,000 to 20,000 obtained by polymerization and (C) a photopolymerization initiator is suitable as a void filling resin used in an image display device or the like. As a result, they have reached the present invention.

The present invention is an active energy ray-curable resin composition for void filling, which contains at least the following components (A) to (C).
Component (A): ethylenically unsaturated group-containing compound,
Component (B): a copolymer having a weight average molecular weight of 1,000 to 20,000 obtained by continuous polymerization of a vinyl monomer at a copolymerization temperature of 150 to 350 ° C.,
Component (C): Photopolymerization initiator.

In addition, in this specification, the crosslinked material or hardened | cured material obtained by irradiating an active energy ray to a composition is collectively represented as "hardened | cured material." Further, acrylate or methacrylate is represented as (meth) acrylate, and acryl or methacryl is represented as (meth) acryl.
Hereinafter, the present invention will be described in detail.

  The active energy ray-curable resin composition for void filling of the present invention contains an ethylenically unsaturated group-containing compound as component (A) as a curable component and is obtained by high-temperature continuous polymerization as component (B). In addition, since the composition contains a relatively low molecular weight copolymer, the composition has low viscosity, excellent fluidity, excellent void filling properties, and is suitable as a filling resin for improving impact resistance, as well as curability and adhesion. In addition, the cured product has excellent transparency.

  Further, as the composition of the present invention, the component (A) contains a (meth) acrylate having an alkoxysilyl group in the molecule, or a copolymer having an alkoxysilyl group is used as the component (B). As a result, the curing progresses by the crosslinking reaction of the alkoxysilyl group even at a location where the active energy rays irradiated at the time of curing are not sufficiently reached, such as the edge of the image display device, so that sufficient adhesion reliability of the entire image display device is achieved. Sex can be secured. Therefore, according to the present invention, a high-quality image display device can be obtained.

  The resin composition of the present invention contains the components (A) and (B) described above as the resin component. Hereinafter, both components will be described.

1. Ingredient (A)
Component (A) of the present invention is an ethylenically unsaturated group-containing compound.
Examples of the ethylenically unsaturated group in the component (A) include a vinyl group, a vinyl ether group, a (meth) acryloyl group, and a (meth) acrylamide group.
As the component (A), various compounds can be used. Specific examples include (meth) acrylate, (meth) acrylamide, aromatic vinyl compounds such as styrene and vinyltoluene, vinyl acetate, N-vinylpyrrolidone, N-vinylformamide, and N-vinylcaprolactam.

Among these, (meth) acrylate is preferable.
As the (meth) acrylate, a compound having one (meth) acryloyl group [hereinafter referred to as “monofunctional (meth) acrylate”] and a compound having two or more (meth) acryloyl groups [hereinafter referred to as “polyfunctional”. ("Meth) acrylate").

  Monofunctional (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, and stearyl ( Alkyl (meth) acrylates such as meth) acrylates; alicyclics such as cyclohexyl (meth) acrylates, tricyclodecane (meth) acrylates, dicyclopentenyl (meth) acrylates, isobornyl (meth) acrylates and adamantyl (meth) acrylates ( (Meth) acrylate; 2-methoxyethyl (meth) acrylate, methoxytriethylene glycol (meth) acrylate, 2-ethylhexyl carbitol (meth) acrylate, ethoxyethoxy Alkoxyalkyl (meth) acrylates such as ethyl (meth) acrylate; phenoxyethyl (meth) acrylate, nonylphenoxyethyl (meth) acrylate, benzyl (meth) acrylate, (meth) acrylate of a phenol derivative modified with alkylene oxide and 2- Aromatic (meth) acrylate of hydroxy-3-phenoxypropyl (meth) acrylate; tetrahydrofurfuryl (meth) acrylate; N- (meth) acryloyloxyethyl tetrahydrophthalimide and N- (meth) acryloyloxyethyl hexahydrophthalimide Maleimide (meth) acrylate; and oxazolidinone ethyl (meth) acrylate.

Examples of the polyfunctional (meth) acrylate include 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 3-methyl-1, 5-pentanediol di (meth) acrylate, 2-butyl-2-ethyl-1,3-nonanediol diacrylate, 2-methyl-1,8-octanediol di (meth) acrylate, 2-hydroxy-1,3 -Di (meth) acryloyloxypropane, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, glycerin di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, Pentaerythritol tetra (meta) Polyol poly (meth) acrylates such as acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate; alkylene oxides of the starting alcohol for these poly (meth) acrylates [ Ethylene oxide and propylene oxide, etc.] Adduct poly (meth) acrylates; Poly (meth) acrylates of caprolactone modified products of the raw alcohols of these poly (meth) acrylates; Di (meth) acrylates and ethylene oxides of ethylene oxide-modified isocyanuric acid Examples include poly (meth) acrylates of alkylene oxide modified isocyanuric acid such as tri (meth) acrylate of modified isocyanuric acid. Not limited to.
As polyfunctional (meth) acrylate, an oligomer can also be used, and specifically, urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate and the like can be mentioned.

  As (meth) acrylamide, N-alkyl (meth) acrylamide such as N-methyl (meth) acrylamide and N-ethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide and N, N-diethyl (meth) N, N-dialkyl (meth) acrylamide such as acrylamide, (meth) acryloylmorpholine and the like can be mentioned.

When the composition of the present invention is a moisture-curing composition, it is preferable to use a (meth) acrylate having an alkoxysilyl group.
As the (meth) acrylate having an alkoxysilyl group, a (meth) acrylate having a methoxysilyl group or an ethoxysilyl group is preferable from the viewpoint of excellent reactivity and flexibility of a cured product.
Specific examples of the (meth) acrylate having a methoxysilyl group or an ethoxysilyl group include, for example, trimethoxysilylpropyl (meth) acrylate, triethoxysilylpropyl (meth) acrylate, methyldimethoxysilylpropyl (meth) acrylate, and dimethylmethoxy. Examples include silylpropyl (meth) acrylate.

  These compounds may be used alone or in combination of two or more.

As the component (A), a polyfunctional (meth) acrylate is preferable in that it has excellent impact resistance after curing and can have an appropriate viscosity capable of preventing bleeding when used for hole filling. In the present invention, the component (B) acts as a plasticizer, so that even if only a polyfunctional (meth) acrylate is used as the component (A), the viscosity can be made appropriate as a composition for void fillers. .
It is preferable that 20-100 weight% of polyfunctional (meth) acrylate is contained in a component (A), More preferably, it is 50-100 weight%.

  When (meth) acrylate having an alkoxysilyl group is used as the component (A), the content thereof is preferably 10 to 70% by weight, more preferably 30 to 50% by weight in the component (A).

2. Ingredient (B)
Component (B) of the present invention is a copolymer having a weight average molecular weight of 1,000 to 20,000 obtained by continuous polymerization of a vinyl monomer at a copolymerization temperature of 150 to 350 ° C.

  There is no restriction | limiting in particular as a vinyl-type monomer which can be used for the copolymer of a component (B), (meth) acrylate, (meth) acrylic acid, styrene, (alpha) -methylstyrene, acrylonitrile, vinyl acetate, etc. are mentioned. However, (meth) acrylate is preferred because of excellent copolymerizability, mechanical properties of the cured product, weather resistance, water resistance, and the like.

  Examples of (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) ) Acrylate, t-butyl (meth) acrylate, neopentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, etc. Alicyclic alkyl (meth) acrylates such as alkyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate and tricyclodecynyl (meth) acrylate, -Heteroatom-containing (meth) acrylates such as methoxyethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, chloroethyl (meth) acrylate, trifluoroethyl (meth) acrylate and tetrahydrofurfuryl (meth) acrylate .

  Among these, alkyl (meth) acrylates having 4 or more carbon atoms are preferable because they give the cured product flexibility and are excellent in water resistance and weather resistance. The proportion of the alkyl (meth) acrylate having 4 or more carbon atoms is preferably 40 parts by weight or more (when the total amount of monomers used for the production of the component (B) copolymer is 100 parts by weight). If it is less than 40 parts by weight, the glass transition temperature becomes high, and the flexibility of the cured product may be insufficient.

For the purpose of imparting moisture curability to the component (B), a vinyl monomer having an alkoxysilyl group can be copolymerized.
Examples of vinyl monomers having an alkoxysilyl group include vinyltrimethoxysilane, vinyltriethoxysilane, vinylmethyldimethoxysilane and vinylalkoxysilanes such as vinylmethoxydimethylsilane, trimethoxysilylpropyl (meth) acrylate, and triethoxy. Alkoxysilyl group-containing (meth) acrylates such as silylpropyl (meth) acrylate and methyldimethoxysilylpropyl (meth) acrylate, alkoxysilyl group-containing vinyl ethers such as trimethoxysilylpropyl vinyl ether, alkoxy such as vinyl trimethoxysilylundecanoate Examples include silyl group-containing vinyl esters.
Among these, alkoxysilyl group-containing (meth) acrylates are preferable because they are excellent in copolymerizability with other vinyl monomers and the flexibility of the resulting copolymer.

  A preferable ratio in the case of copolymerizing a vinyl monomer having an alkoxysilyl group with the component (B) is 5 to 70 parts by weight, more preferably 10 to 50 parts by weight (a copolymer of the component (B) When the total amount of monomers used in the production of 100 parts by weight is used). If it is less than 5 parts by weight, the moisture curability may be insufficient, and if it exceeds 70 parts by weight, the gap filling property and adhesiveness may be deteriorated.

  These monomers may polymerize one type or two or more types.

Component (B) can be obtained by radical polymerization, and can be obtained by a high-temperature continuous polymerization method at 150 to 350 ° C. The polymerization method may be any of solution polymerization, bulk polymerization, and dispersion polymerization, and may also be a living radical polymerization method developed in recent years. When the polymerization temperature is less than 150 ° C., branching reaction occurs and the molecular weight distribution is widened, and a large amount of initiator and chain transfer agent are required to lower the molecular weight, thus adversely affecting the weather resistance, heat resistance and durability. give. In addition, production problems such as heat removal may occur. On the other hand, if it is higher than 350 ° C., a decomposition reaction occurs and the polymerization solution is colored or the molecular weight is lowered. By polymerizing in this temperature range, it is possible to efficiently produce a copolymer having an appropriate molecular weight, a low viscosity, no coloration and little impurities.
That is, according to the polymerization method, a very small amount of polymerization initiator may be used, and it is not necessary to use a chain transfer agent such as mercaptan or a polymerization solvent, and a highly pure copolymer can be obtained. In general, it is important to uniformly introduce a crosslinkable functional group into a polymer in order to maintain physical properties such as curability and weather resistance. It is preferable to use a stirred tank reactor as the reactor because a (meth) acrylic acid ester copolymer having a relatively narrow composition distribution (distribution of crosslinkable functional groups) and molecular weight distribution can be obtained. Also, a process using a continuous stirred tank reactor is more preferable than a tubular reactor because the composition distribution and molecular weight distribution are narrowed.

As the high-temperature continuous polymerization method, a known method disclosed in JP-A-57-502171, JP-A-59-6207, JP-A-60-215007, or the like may be used.
For example, after filling a pressurizable reactor with a solvent and setting it to a predetermined temperature under pressure, the reactor is charged with a monomer mixture composed of each monomer and, if necessary, a polymerization solvent at a constant supply rate. And a method of extracting a polymerization solution in an amount commensurate with the supply amount of the monomer mixture. Moreover, a polymerization initiator can also be mix | blended with a monomer mixture as needed. The blending amount when blended is preferably 0.001 to 2 parts by weight with respect to 100 parts by weight of the monomer mixture.
The pressure depends on the reaction temperature, the monomer mixture used and the boiling point of the solvent, and does not affect the reaction, but may be any pressure that can maintain the reaction temperature.
The residence time of the monomer mixture is preferably 1 to 60 minutes. If the residence time is less than 1 minute, the monomer may not sufficiently react, and if the unreacted monomer exceeds 60 minutes, the productivity may deteriorate. The preferred residence time is 2 to 40 minutes.

The weight average molecular weight of the component (B) is preferably 1,000 to 20,000, more preferably 2,000 to 15,000. When the weight average molecular weight is less than 1,000, the mechanical strength of the curable composition is not sufficient, and when it exceeds 20,000, the viscosity becomes too high.
The polydispersity (Mw / Mn), which is the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the component (B), is preferably 5 or less, and more preferably 3 or less. The reason is that the balance between the viscosity of the composition and the physical properties of the resulting coating is good.
In the present invention, the number average molecular weight and the weight average molecular weight mean a molecular weight in terms of polystyrene measured by gel permeation chromatography (hereinafter referred to as “GPC”) using tetrahydrofuran as a solvent.
Moreover, -80-20 degreeC is preferable and, as for the glass transition temperature of a component (B), More preferably, it is -70-10 degreeC. When it exceeds 20 degreeC, workability | operativity will worsen and gap filling property will be inferior.

  When the component (B) contains an alkoxysilyl group, the number of alkoxysilyl groups in one molecule is preferably 0.1 to 4, more preferably 0.3 to 3. If it is less than 0.1, curing is insufficient, and if it exceeds 4, the cured product becomes hard.

The radical polymerization initiator used for the production of the component (B) may be any initiator that generates radicals at a predetermined reaction temperature. Specifically, peroxides such as diisopropyl peroxydicarbonate, di-2-ethoxyethyloxydicarbonate, tertiary butyl peroxypivalate, ditertiary butyl peroxide, benzoyl peroxide and lauroyl peroxide, or 2, Azo compounds such as 2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile) and 2,2'-azobis (2,4-dimethylvaleronitrile), ammonium persulfate and persulfate Examples thereof include inorganic peroxides such as potassium and metal complexes used for living polymerization. Further, a thermally initiated radical generated from styrene or the like may be used.
Particularly preferably, ditertiary butyl peroxide, ditertiary hexyl peroxide, ditertiary amyl peroxide, and azo initiator are inexpensive and the initiator radicals are less likely to cause hydrogen abstraction. When the hydrogen abstraction reaction occurs frequently, the molecular weight distribution becomes wide, and a low molecular weight component into which no crosslinkable functional group is introduced is likely to be formed, and the weather resistance may be deteriorated.

  In the present invention, solution polymerization performed in an organic solvent and bulk polymerization performed without a solvent can be used. Among these, bulk polymerization is preferable, but when an organic solvent is used, organic hydrocarbon compounds are suitable, cyclic ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbon compounds such as benzene, toluene and xylene, ethyl acetate, and the like. And esters such as butyl acetate, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, and alcohols such as methanol, ethanol, and isopropanol are exemplified, and one or more of these can be used. In a solvent that does not dissolve the (meth) acrylic acid ester copolymer well, scales are likely to grow on the walls of the reactor, and production problems are likely to occur in the cleaning process. The amount of solvent used is preferably 80 parts or less.

  The composition ratio of the component (A) and the component (B) is such that the total amount of the component (A) and the component (B) is 100% by weight, the component (A) is 40 to 80% by weight, and the component (B) is 60 to 60%. 20 weight% is preferable, More preferably, a component (A) is 50 to 70 weight% and a component (B) is 50 to 30 weight%. When the component (A) is less than 40 parts by weight, curability and adhesive strength are insufficient.

3. Ingredient (C)
Component (C) is a photopolymerization initiator. Component (C) is a compound that generates radicals upon irradiation with active energy rays and initiates polymerization of component (A).

Specific examples of component (C) include benzyl dimethyl ketal, benzyl, benzoin, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropane -1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, oligo [2-hydroxy-2-methyl-1- [4-1- (methyl) Vinyl) phenyl] propanone, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] -phenyl} -2-methylpropan-1-one, 2-methyl-1- [ 4- (Methylthio)] phenyl] -2-morpholinopropane-1 ON, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholin-4-yl-phenyl) ) -Butane-1-one, Adekaoptomer N-1414 (Asahi Denka), phenylglyoxylic acid methyl ester, ethyl anthraquinone, phenanthrenequinone, and other aromatic ketone compounds;
Benzophenone, 2-methylbenzophenone, 3-methylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzophenone, 4-phenylbenzophenone, 4- (methylphenylthio) phenylphenylmethane, methyl-2-benzophenone, 1- [4- (4-Benzoylphenylsulfanyl) phenyl] -2-methyl-2- (4-methylphenylsulfonyl) propan-1-one, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis ( Benzophenone compounds such as diethylamino) benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone, N, N′-tetraethyl-4,4′-diaminobenzophenone and 4-methoxy-4′-dimethylaminobenzophenone ;
Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl- (2,4,6-trimethylbenzoyl) phenylphosphinate and bis (2,6 -Acylphosphine oxide compounds such as -dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide;
Thioxanthone, 2-chlorothioxanthone, 2,4-diethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propylthioxanthone, 3- [3,4-dimethyl-9-oxo-9H-thioxanthone-2-yl] oxy] -2-hydroxy Thioxanthone compounds such as propyl-N, N, N-trimethylammonium chloride and fluorothioxanthone;
Acridone compounds such as acridone and 10-butyl-2-chloroacridone;
1,2-octanedione 1- [4- (phenylthio) -2- (O-benzoyloxime)], ethanone 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1 Oxime esters such as-(O-acetyloxime), 2- (o-chlorophenyl) -4,5-diphenylimidazole dimer, 2- (o-chlorophenyl) -4,5-di (m-methoxyphenyl) Imidazole dimer, 2- (o-fluorophenyl) -4,5-phenylimidazole dimer, 2- (o-methoxyphenyl) -4,5-diphenylimidazole dimer, 2- (p-methoxyphenyl) ) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer and 2- (2,4-dimethoxy) 2,4,5-triarylimidazole dimers such as phenyl) -4,5-diphenylimidazole dimer; and acridines such as 9-phenylacridine and 1,7-bis (9,9'-acridinyl) heptane Derivatives and the like.
These compounds can be used alone or in combination of two or more.

As a mixture ratio of a component (C), 0.1 to 10 weight% is preferable with respect to 100 weight part of total amounts except the component (C) in a composition, More preferably, 0.5 to 5 weight% It is.
By setting the blending ratio of component (C) to 0.1% by weight or more, the composition can be cured with an appropriate amount of active energy dose, and the productivity can be improved. Thus, the cured product can be made excellent in weather resistance and transparency.

4). Other components Although this invention makes above-described component (A), (B) and (C) essential, you may contain a various component as needed. Hereinafter, other components will be described.
4-1. Organic Solvent The composition of the present invention may be a solvent-free system that does not contain an organic solvent, or may contain an organic solvent for the purpose of improving coating properties. As an organic solvent, the organic solvent mentioned above in connection with manufacture of a component (B) can be used, for example.
The use ratio of the organic solvent may be set as appropriate, but is preferably 10 to 90% by weight, more preferably 30 to 80% by weight in the composition.

4-2. Moisture Curing Catalyst When the composition of the present invention is used as a moisture curable composition, it is preferable to use a moisture curing catalyst.
Moisture curing catalysts include those used in conventional moisture curable compositions, and alkoxysilyl group-containing copolymers and alkoxysilyl group-containing (meth) acrylate alkoxysilyl groups can be condensed with moisture. Any compound can be used as long as it is.
Specifically, tin-based catalysts such as dibutyltin laurate, dibutyltin diacetate and dibutyltin diacetoacetonate, titanates such as tetrabutyltitanate and tetrapropyltitanate; aluminum trisacetylacetonate, aluminum trisethylacetate Organoaluminum compounds such as acetate and diisopropoxyaluminum ethyl acetoacetate; Chelate compounds such as zirconium tetraacetylacetonate and titanium tetraacetylacetonate; Lead octylate; Butylamine, octylamine, dibutylamine, monoethanolamine, diethanolamine , Triethanolamine, diethylenetriamine, triethylenetetramine, oleylamine, cyclohexylamine, benzylamine, diethyl Aminopropylamine, xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, 2,4,6-tris (dimethylaminomethyl) phenol, morpholine, N-methylmorpholine, 2-ethyl-4-methylimidazole and 1,8- Examples include amine compounds such as diazabicyclo (5,4,0) undecene-7 (DBU); salts of these amine compounds with carboxylic acids and the like. Moreover, silanol condensation catalysts such as carboxylic acids, carboxylic acid metal salts, organic sulfonic acids, acidic phosphoric acid esters, organometallic compounds containing a group 3B / group 4A metal, other acidic catalysts, and basic catalysts.
The use ratio of the moisture curing catalyst may be appropriately set depending on the purpose and the type and ratio of the copolymer having an alkoxysilyl group and / or the (meth) acrylate having an alkoxysilyl group. 0.1 to 10 weight% is preferable in a thing, More preferably, it is 0.5 to 5 weight%.

4-3. Other components In addition to the above, the composition of the present invention may contain an inorganic material, a leveling agent, a silane coupling agent, a polymerization inhibitor and / or an antioxidant, a light resistance improver, etc., if necessary. Can do.

5. Active energy ray-curable void filling resin composition The composition of the present invention essentially comprises the components (A), (B) and (C).
The manufacturing method of the composition of this invention should just follow a conventional method, and can stir and mix the said component (A), (B) and (C) and another component as needed. If necessary, the mixing time can be shortened by heating.
The composition of the present invention can be widely used to fill voids in articles, and in particular, a surface protective layer and a touch panel module which are constituent members of an image display device including a touch panel (hereinafter referred to as “touch panel type image display device”). In addition, it can be suitably used to paste these members together by filling them between the image display units.

6). Touch Panel Type Image Display Device The touch panel type image display device mainly includes a surface protective layer, a touch panel module, and an image display unit.
The composition of the present invention can be mainly used to fill a gap between the surface protective layer or the touch panel module and the image display unit and a gap between the surface protective layer and the touch panel module.
For example, when filling the gap between the surface protective layer and the touch panel module, the composition of the present invention is applied to the surface of the surface protective layer facing the touch panel module, and the touch panel module is bonded to the coated surface, and then transparent. What is necessary is just to irradiate an active energy ray to a coating surface through the surface protective layer which is material. A space between the surface protective layer or the touch panel module and the image display unit can be filled with the composition of the present invention in accordance with the above method.
In order to increase the interlayer adhesion, an activation treatment can be performed on one or both surfaces to be bonded. Examples of the surface activation treatment include plasma treatment, corona discharge treatment, chemical treatment, surface roughening treatment, etching treatment, and flame treatment, and these may be used in combination.

The coating amount of the composition of the present invention may be appropriately selected according to the use to be used, but it is preferable that the coating film thickness is 0.5 to 500 μm, more preferably 5 to 5 μm. 200 μm.
As a coating method, it may be appropriately set according to the purpose, and a method of coating with a conventionally known bar coater, doctor blade, knife coater, comma coater, reverse roll coater, die coater, gravure coater, micro gravure coater, etc. Is mentioned.

When the composition contains an organic solvent, the composition is dried after coating to evaporate the organic solvent.
What is necessary is just to set drying conditions suitably according to the organic solvent to be used, and the method etc. which heat to the temperature of 40-120 degreeC are mentioned.

Examples of the active energy rays used for curing the composition of the present invention include ultraviolet rays, visible rays, X-rays, and electron beams. Since inexpensive devices can be used, it is possible to use ultraviolet rays and / or visible rays. preferable. Various light sources can be used as the light source in the case of curing with ultraviolet rays and / or visible rays. Suitable light sources include low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultra high pressure mercury lamps, metal halide lamps, UV electrodeless lamps, and LEDs that emit ultraviolet and / or visible light.
What is necessary is just to select suitably irradiation conditions, such as irradiation intensity | strength in active energy ray irradiation, according to the composition to be used, a base material, the objective, etc.

The surface protective layer is a layer disposed on the outermost surface when disposed on the image display device.
The surface protective layer may be composed of only a polymer film, glass, or the like, or may be composed of a plurality of layers together with other layers.
The surface protective layer is not particularly limited as long as it is conventionally used as a protective film for an image display device, and can be, for example, an acrylic resin such as polymethyl methacrylate (PMMA), a polycarbonate resin, or glass. The thickness of the surface protective layer is usually 0.1 to 5 mm.

When the surface protective layer is a laminate composed of a plurality of layers, on the observer side of the image display device, functions such as wear resistance, scratch resistance, antifouling property, antireflection property, antistatic property, etc. A layer for imparting properties can be provided.
For example, abrasion resistance and scratch resistance can be obtained by forming a hard coat layer. Furthermore, it is possible to impart antistatic properties, antifouling properties and the like to the hard coat layer.

When the surface protective layer is a laminate composed of a plurality of layers, an additional layer such as a printed layer, a hard coat layer, or a vapor deposition layer is formed on the entire surface or a part of the surface protective layer on the opposite side of the observer side. It may be included in the area.
When such an additional layer is formed in a partial region of the surface protective layer, the surface protective layer becomes a surface having an uneven shape. The thickness of the surface protective layer in this case is generally 0. 1-6 mm.

  When the surface protective layer has a concavo-convex shape at the end, or when the image display unit includes a layer having a concavo-convex shape at the end, the surface protective layer or the entire image display unit may be bonded to another member. Since the composition of the present invention fills the uneven shapes of the end portions without any gaps, a high-quality image display device can be obtained. In addition, when the component (B) of the composition of the present invention has an alkoxysilyl group in the molecule, or the composition of the present invention contains a (meth) acrylate having an alkoxysilyl group in the component (A) Since the composition of the present invention has moisture curability, it is also prevented from being cured by moisture at such an end portion and causing peeling at the end portion.

  Examples of the touch panel module include various systems such as a capacitive film system such as a resistive film system, a surface capacitive system, and a projected capacitive system.

Examples of the image display unit include transmissive or reflective liquid crystal display units, plasma display units, organic EL (OLED) units, and image display units such as electronic paper.
An additional functional layer (single layer or multiple layers), for example, a polarizing plate or the like can be provided on the display surface of the image display unit. A touch panel module may be present on the display surface of the image display unit.

The touch panel image display device can be used for various electronic devices.
Specific examples of the electronic device include a mobile phone, a smart phone, a portable information terminal, a portable game machine, an electronic book, a car navigation system, a portable music player, a clock, a tablet computer, a video camera, a video player, a digital camera, Examples include a positioning system (GPS) device and a personal computer (PC).

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the following description, “part” means part by weight, and “%” means weight%.

The meanings of the abbreviations used in the examples are as follows.
M402: A mixture of dipentaerythritol pentaacrylate and hexaacrylate, Aronix M402 manufactured by Toagosei Co., Ltd.
DPCA60: caprolactone-modified dipentaerythritol hexaacrylate, KAYARAD DPCA60 manufactured by Nippon Kayaku Co., Ltd.
Polymer A: alkoxysilyl group-containing polymer obtained in Production Example 1 described later (Tg = −57 ° C., Mw = 3300, Mw / Mn = 1.9).
Polymer B: acrylic polymer obtained in Production Example 2 described later (Tg = −64 ° C., Mw = 2500, Mw / Mn = 1.6).
Irg379: 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, manufactured by BASF.
KBM5103: 3-acryloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical
DBTDL: dibutyltin dilaurate, manufactured by ADEKA

○ Production Example 1 [Production of component (B)]
The temperature of a 1000 ml capacity pressurized stirred tank reactor equipped with an oil jacket was kept at 200 ° C. Next, while maintaining the reactor pressure constant, 10 parts of methyl methacrylate (hereinafter also referred to as “MMA”), 77 parts of butyl acrylate (hereinafter also referred to as “BA”), 13 parts of trimethoxysilylpropyl methacrylate, isopropyl alcohol A monomer mixture consisting of 8 parts (hereinafter also referred to as “IPA”), 4 parts of trimethyl orthoacetate and 1 part of ditertiary hexyl peroxide as a polymerization initiator is supplied at a constant feed rate (48 g / min, residence time: 12 minutes), continuous supply from the raw material tank to the reactor was started, and a reaction solution corresponding to the supply amount of the monomer mixture was continuously withdrawn from the outlet. Immediately after the start of the reaction, once the reaction temperature decreased, a temperature increase due to the heat of polymerization was observed, but the reaction temperature was maintained at 227 to 229 ° C. by controlling the oil jacket temperature.
The time when the temperature became stable from the start of the supply of the monomer mixture was taken as the reaction liquid collection start point, and the reaction was continued for 25 minutes. As a result, 1.2 kg of the monomer mixture was supplied, and 1.2 kg of reaction was started. The liquid was collected.
Thereafter, the reaction solution was introduced into a thin film evaporator to separate volatile components such as unreacted monomers to obtain a concentrated solution. The resulting copolymer is referred to as polymer A.
Tetrahydrofuran was used as the solvent, and the polystyrene-reduced weight average molecular weight (hereinafter also referred to as “Mw”) measured by GPC was 3300, and Mw / Mn was 1.9.

○ Production Example 2 [Production of component (B)]
Manufactured except that the monomer mixture is changed to 20 parts MMA, 80 parts 2-ethylhexyl acrylate, 25 parts methyl ethyl ketone, 1 part ditertiary butyl peroxide as a polymerization initiator, and the reaction temperature is maintained at 234-236 ° C. Polymerization and treatment were performed in the same manner as in Example 1 to obtain a copolymer. The copolymer is referred to as polymer B.
The Mw of the polymer B was 2500 and Mw / Mn = 1.6.

(Examples 1 to 4 and Comparative Examples 1 to 3)
The compounds shown in Table 1 were charged into a stainless steel container at the ratio shown in Table 1, and stirred at room temperature until uniform with a magnetic stirrer to obtain an active energy ray-curable resin composition for void filling. The obtained composition was evaluated by the following evaluation methods.

(Evaluation method)
(1) UV curable The composition was applied to a glass plate with a bar coater (50 μm). Each time UV irradiation was performed once under the following conditions, the surface was touched with a finger, and the number of irradiation times until the liquid material did not adhere (pass ) Was measured.
UV irradiation conditions: 80 W / cm condensing type metal halide lamp, lamp height 10 cm (focus), conveyor speed 5 m / min.

(2) Moisture-curing property The composition was applied to a glass plate with a bar coater (50 μm) and allowed to stand under the following conditions. Then, the surface was touched with a finger, and the number of days until no liquid matter adhered was measured.
Standing conditions: 30 ° C., 80% Rh.

(3) Tensile shear strength After applying the composition to a glass plate with a bar coater (50 μm) and bonding another glass plate together, UV test was performed 5 times under the following conditions to prepare a test piece. The tensile shear strength was measured according to JIS K6850.
UV irradiation conditions: 80 W / cm condensing type metal halide lamp, lamp height 10 cm (focus), conveyor speed 5 m / min.

In Examples 1 to 4 which are the compositions of the present invention, both UV curability and tensile shear strength were excellent. In addition, since Example 1 is not a moisture curable composition, moisture sclerosis | hardenability is not evaluated.
Further, in the moisture curable compositions of Examples 2 to 4 using the component (B) having an alkoxysilyl group in the molecule and / or the acrylate having the alkoxysilyl group in the molecule (component (A)), the moisture is further increased. The curability was excellent.
On the other hand, since Comparative Example 1 did not contain the component (A) of the present invention, both UV curability and tensile shear strength were inferior. Moreover, since the comparative example 2 does not contain the component (B) of this invention, both UV sclerosis | hardenability and tensile shear strength were inferior. In Comparative Example 3, since the content of the component (A) of the present invention was too small, both the UV curability and the tensile shear strength were inferior.

  The active energy ray-curable resin composition for void filling of the present invention is used for filling voids in articles, for example, filling and bonding between layers of a laminate, in particular, any or all of touch panel modules, surface protective layers, and image display units. Can be suitably used for the manufacture of an image display device characterized by being fixed.

Claims (7)

Containing at least the following components (A) to (C),
An active energy ray comprising 40 to 80% by weight of the following component (A) and 60 to 20% by weight of the following component (B) with respect to a total of 100% by weight of the following components (A) and (B) A curable void filling resin composition.
Component (A): (meth) acrylate having an alkoxysilyl group and / or an ethylenically unsaturated group-containing compound containing two or more (meth) acryloyl group-containing compounds as essential components (however, two or more The compound having a (meth) acryloyl group is contained in the component (A) in an amount of 20 to 100% by weight) .
Component (B): a copolymer having a weight average molecular weight of 1,000 to 20,000 obtained by continuous polymerization of a vinyl monomer at a copolymerization temperature of 150 to 350 ° C.,
Component (C): Photopolymerization initiator. The composition according to claim 1, wherein the vinyl monomer of component (B) contains an alkyl (meth) acrylate having an alkyl group having 4 or more carbon atoms. The composition according to claim 1 or 2, wherein the glass transition temperature of component (B) is -80 to 20 ° C. The composition according to any one of claims 1 to 3, wherein the polydispersity of the component (B) is 5 or less. The composition according to any one of claims 1 to 4, wherein the component (B) has an alkoxysilyl group in the molecule. The composition according to any one of claims 1 to 5, comprising (meth) acrylate having an alkoxysilyl group in an amount of 10 to 70% by weight in the component (A). An image display device, wherein any or all of the touch panel module, the surface protective layer, and the image display unit are fixed by the cured product of the composition according to any one of claims 1 to 6.