JP5136058B2 - Photocurable composition for adhesives, photocurable adhesive sheet, laminate and adhesive sheet - Google Patents

Description

  The present invention relates to a photocurable adhesive composition, a photocurable adhesive sheet, a laminate and an adhesive sheet using the composition, and belongs to these technical fields.

As an agent for bonding two materials, a pressure-sensitive adhesive has a feature not found in a liquid adhesive.
One of its features is that it does not flow. For example, when a sheet-like material is bonded to another solid, if a pressure-sensitive adhesive is previously applied to the surface of the sheet-like material to be bonded, it can be stored, transported and processed in that state. For example, an ultraviolet cut film to be attached to a window glass of an automobile is commercially available in a form in which an adhesive is previously applied to one surface thereof. For this reason, it is easy to store and transport, and it can be processed and pasted into various shapes.
In addition, since the adhesive does not flow, it has a feature that the liquid does not protrude from the corner when the two materials are bonded together. For example, when a functional film such as a lens sheet of a projection television is adhered to a plate-like material, if a liquid adhesive is used, the adhesive protrudes from the corner portion, or conversely, the adhesive is insufficient and the corner is not sufficient. There arises a problem that the part of is not adhered. When protruding, if both materials are film-like, it is relatively easy to cut and discard the defective part of the corner, but it is not easy if it is plate-like, peeling or cracking in the vicinity of the cut part, etc. It becomes difficult to prevent defects. This problem is particularly remarkable when the plate-like material is glass. However, if an adhesive is previously applied to such a functional film and a release film is applied and protected, the film can be uniformly applied to the corners of the film. Moreover, it is possible to cut out to any size at any time.
Furthermore, since it does not flow, it has the feature that only the convex part of the shape which has unevenness | corrugations, such as a lens, can be affixed. If it is sticky, it can be fixed with the tip of the convex surface slightly biting into the adhesive, but in the case of a liquid, the liquid soaks into the concave surface. Not suitable for.

  However, the pressure-sensitive adhesive is an inherently soft material because it has the essential performance that it can be attached only by pressing it onto the adherend. Therefore, compared with the adhesive, the strength, heat resistance, and moist heat resistance are often inferior to the shear force.

From such a background, in recent years, attention has been focused on so-called adhesives, which are initially pressure-sensitive adhesives, but become hardened by heat and light to become adhesives. For example, a photocurable composition for an adhesive is known, which is initially an adhesive but cures when irradiated with light and changes to an adhesive.
As a photocurable composition for adhesives, specifically, a photocationically curable adhesive composition comprising a hydroxyl group-containing (meth) acrylate, an epoxy resin, and a photocationic polymerization initiator (see Patent Document 1). ), A cationic polymer such as a polyacrylate, a cationically curable compound such as an epoxy resin, and a cationic photopolymerization initiator (see Patent Document 2). . When these compositions are irradiated with light, cationic polymerization starts and cures to become an adhesive.

Japanese Patent No. 3043392 (Claims) Japanese Patent Laid-Open No. 10-120995 (Claims)

However, the conventional photocurable composition for adhesives has insufficient shearing adhesive strength and adhesive retention strength at high temperature and high temperature and high humidity.
Moreover, in the case of the composition for photocationic curing type adhesives, the fault of cationic polymerization itself was not avoided. Disadvantages include a problem that the curability deteriorates in a high-humidity environment or on a water-absorbing or hydrophilic substrate, acid derived from a photocationic polymerization initiator, corrosion problems due to ions, and the like.

  The present invention is excellent in shear adhesive strength and adhesive retention strength at high temperatures and high temperatures and high humidity, particularly excellent in curability on high humidity environments and water-absorbing or hydrophilic substrates, and has problems such as corrosion. It aims at providing the photocurable composition for adhesives which does not have, and the photocurable adhesive sheet which uses this, a laminated body, and an adhesive sheet. It is another object of the present invention to provide an adhesive sheet that can be easily applied to a substrate and has excellent shear strength and adhesive retention after light irradiation.

In order to solve the above problems, the present inventors have found that a photocurable composition using polyvinylpyrrolidone or a vinylpyrrolidone copolymer and a (meth) acrylate having a hydrophilic group in combination is effective. Completed the invention.
That is, the present invention has been solved by means described in the following <1>, <11>, <12> and <14> to <16>. It describes below with <2>-<10> and <13> which are preferable embodiments.
<1> (A) a polymer having vinylpyrrolidone as an essential constituent monomer unit and a K value of 20 or more, (B) a compound having a (meth) acryloyl group and a hydrophilic group, and (C) a photoradical A photo-curing agent for adhesives, containing a polymerization initiator and having a weight ratio ((A) / (B)) of component (A) and component (B) of 90/10 to 25/75 Mold composition,
<2> The photocurable composition for adhesives according to <1>, wherein the component (A) is a homopolymer of vinyl pyrrolidone or a copolymer of vinyl pyrrolidone and vinyl acetate,
<3> The photocurable composition for adhesives according to <1> or <2>, wherein the hydrophilic group in the component (B) is a hydroxyl group and / or a carboxyl group,
<4> The photocurable composition for adhesives according to <3>, wherein the component (B) includes a (meth) acrylate having a hydroxyl group,
<5> The photocurable composition for adhesives according to <4>, wherein the component (B) contains glycerin mono (meth) acrylate or polyalkylene glycol mono (meth) acrylate,
<6> The component (B) includes a compound having two or more (meth) acryloyl groups and one or more hydroxyl groups in one molecule, and the content thereof is a total weight of the component (A) and the component (B) 100 <1> The photocurable composition for adhesives according to <4>, which is 1 part by weight or more and 50 parts by weight or less with respect to parts by weight,
<7> The viscosity according to <6>, wherein the compound having two or more (meth) acryloyl groups and one or more hydroxyl groups in one molecule is a (meth) acrylic acid 2-mol adduct of diglycidyl ether. Photocurable composition for adhesives,
<8> The photocurable composition for adhesives according to <3>, wherein the component (B) includes a (meth) acrylate having a carboxyl group,
<9> The component (B) is at least one selected from the group consisting of a (meth) acrylic acid multimer, a caprolactone ring-opened product of (meth) acrylic acid, and an acid anhydride adduct of hydroxyalkyl (meth) acrylate. The photocurable composition for adhesives according to <8>,
<10> The photocurable composition for adhesives according to any one of <1> to <9>, further comprising an organic solvent and / or water,
<11> Photocuring characterized in that the composition according to any one of <1> to <10> is applied to a substrate and dried as necessary to form an adhesive layer. Mold adhesive sheet,
<12> The base material and / or the adherend is a transparent material, the photocurable adhesive sheet according to <11> and the adherend are bonded together, and light is irradiated from the transparent material side to be cured. A laminate characterized by being obtained by
<13> The laminate according to <12>, wherein when the photocurable adhesive sheet and the adherend are bonded together, the photocurable adhesive sheet and / or the adherend is wetted with water.
<14> A sheet manufactured from the photocurable adhesive sheet according to <11> and a release material, wherein the adhesive layer is wetted with water, and is then in close contact with the release material and irradiated with light to form a cured film. An adhesive sheet characterized by being formed;
<15> An adhesive sheet formed by irradiating the adhesive layer of the photocurable adhesive sheet according to <11> with light to form a cured film,
<16> An adhesive sheet obtained by irradiating the adhesive layer of the photocurable adhesive sheet according to <11> with light to form a cured film, and then wetting the cured film layer with water.

  According to the present invention, it has excellent shear strength and adhesive strength, and also has excellent adhesive retention at high temperatures and high temperatures and high humidity, and is particularly excellent in curability under high humidity environments and on water-absorbing or hydrophilic substrates. It is possible to provide a photocurable composition for an adhesive without problems such as corrosion, and a photocurable adhesive sheet, a laminate and an adhesive sheet using the composition. Moreover, according to the photocurable adhesive sheet of the present invention, it is possible to provide an adhesive sheet that can be easily applied to various adherends and has excellent shear strength and adhesive retention after light irradiation. it can.

An example of manufacture of a photocurable adhesive sheet using the photocurable composition for an adhesive of the present invention will be shown. An example of laminate production using the photo-curable adhesive sheet of the present invention will be shown. An example of adhesive sheet manufacture using the photocurable composition for an adhesive of the present invention or a photocurable adhesive sheet is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Adhesive layer 3 Release material 4 Adhering body 5 Water 10 Adhesive photocurable composition 20 Hardened layer 30 Hardened layer B1 which absorbed water Photocurable adhesive sheet B2 Release material Laminated photo-curing adhesive sheet C, C ′ laminate D ₁ , D ₂ , D ₃ adhesive sheet

Hereinafter, the present invention will be described in detail.
The photocurable composition for an adhesive of the present invention (hereinafter also referred to as the composition of the present invention) is a polymer having (A) vinylpyrrolidone as an essential constituent monomer unit and a K value of 20 or more. , (B) a compound having a (meth) acryloyl group and a hydrophilic group, and (C) a radical photopolymerization initiator, and the weight ratio of the component (A) and the component (B) ((A) / (B )) Is 90/10 to 25/75.
In the present specification, an acryloyl group or a methacryloyl group is represented as a (meth) acryloyl group, and an acrylate or methacrylate is represented as a (meth) acrylate.
Hereinafter, each component will be described.

1. Component (A) The component (A) is a polymer having vinyl pyrrolidone as an essential constituent monomer unit and a K value of 20 or more.
(A) As K value of a component, 20-200 are preferable, More preferably, it is 20-130, More preferably, it is 25-100, Especially preferably, it is 50-100. When the K value is less than 20, the state of the coating film before light irradiation is not an adhesive coating film but a liquid state.
The K value is a general parameter “K value of Fikentscher” representing the average molecular weight, the degree of polymerization, and the intrinsic viscosity. The larger the K value, the higher the molecular weight. The molecular weight of polyvinylpyrrolidone is generally represented by this K value, and the K value also defines the average molecular weight in the present invention.
In the present invention, according to the 13th revised Japanese Pharmacopoeia Manual (1996), the K value is the weight of the converted dehydrated product in 100 mL of the solution, c (g), and the kinematic viscosity of the sample solution relative to the kinematic viscosity of the solvent. The ratio is η _rel , K = 1000 · K ₀ , which means the value of K obtained by calculating K ₀ in the following equation.
_{log (η rel) / c =} 75K 0 2 /(1+1.5K 0 c) + K 0

The component (A) may be a homopolymer of vinyl pyrrolidone or a copolymer with a monomer copolymerizable with vinyl pyrrolidone (hereinafter referred to as other monomer).
Other monomers include vinyl acetate, vinyl caprolactam, α-olefins such as 1-butene and 1-hexadecene.
As other monomers, those in which the resulting copolymer is water-soluble are preferred. In this case, the copolymerization ratio of other monomers is preferably 0 to 60 mol%, more preferably 0 to 50 mol%.
Among these, as the component (A), a homopolymer of vinyl pyrrolidone and a copolymer of vinyl pyrrolidone and vinyl acetate (hereinafter also referred to as “VPVA copolymer”) are preferable.

  In the VPVA copolymer, the copolymerization ratio of vinyl pyrrolidone and vinyl acetate is preferably a copolymer containing 70 mol% or less of vinyl acetate, more preferably 20 to 60 mol%. It is preferable that the copolymerization ratio of vinyl acetate is 70 mol% or less because good adhesive force can be obtained. A copolymer having a vinyl acetate copolymerization ratio of 20 mol% or more is preferred because of excellent coating properties of the composition.

  As the component (A), the aforementioned polymers may be used alone or in combination of two or more.

2. Component (B) The component (B) is a compound having a (meth) acryloyl group and a hydrophilic group.
Examples of the hydrophilic group in the component (B) include a hydroxyl group, a carboxyl group, a sulfone group, a phosphate group, an amino group, and an amide group.
Among these, a hydroxyl group and a carboxyl group are preferable from the viewpoints of excellent compatibility with the component (A), a cured film having excellent moisture and heat resistance, and less problems of corrosion of the substrate. Hereinafter, a compound having a (meth) acryloyl group and a hydroxyl group (hereinafter referred to as (B-1)) and a compound having a (meth) acryloyl group and a carboxyl group (hereinafter referred to as (B-2)) will be described.

  Specific examples of the component (B-1) include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate; glycerin mono ( Glycerin (meth) acrylates such as meth) acrylate and glycerin di (meth) acrylate; Polyalkylene glycol mono (meth) acrylates such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate; Mono or trimethylolpropane Di (meth) acrylate, ditrimethylolpropane mono-, di- or tri (meth) acrylate, pentaerythritol mono-, di- or tri (meth) acrylate and dipentaerythritol Mono or poly (meth) acrylates of polyols such as mono-, di-, tri-, tetra- or penta (meth) acrylates; mono- or poly (meth) acrylates of adducts of alkylene oxides (such as ethylene oxide and propylene oxide) of the polyols; And a (meth) acrylic acid 2 mol adduct of polyalkylene glycol diglycidyl ether, a (meth) acrylic acid 1 mol adduct of polyalkylene glycol diglycidyl ether, a (meth) acrylic acid 2 mol adduct of glycerin diglycidyl ether, And a (meth) acrylic acid adduct of diglycidyl ether such as a 1-mole (meth) acrylic acid adduct of glycerin diglycidyl ether.

  (B-1) As a component, the compound excellent in compatibility with (A) component is preferable. Specifically, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, 4-hydroxybutyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (Meth) acrylate, polyethylene glycol diglycidyl ether (repetition number 1 to 20) (meth) acrylic acid 2 mol adduct, glycerin diglycidyl ether (meth) acrylic acid 2 mol adduct, and the like.

  Further, as the component (B-1), it is preferable that glycerin mono (meth) acrylate or polyalkylene glycol mono (meth) acrylate is contained because the adhesive strength after photocuring is excellent.

Next, the component (B-1) contains a compound having two or more (meth) acryloyl groups and one or more hydroxyl groups in one molecule (hereinafter referred to as a hydroxyl group-containing polyfunctional (meth) acrylate). Is preferable because it has excellent wet heat resistance after photocuring. In this case, the mixing ratio of the hydroxyl group-containing polyfunctional (meth) acrylate is preferably in the range of 1 part by weight to 50 parts by weight with respect to 100 parts by weight of the total amount of the component (A) and the component (B). . The amount is more preferably 1 to 30 parts by weight, and further preferably 3 to 20 parts by weight. It is preferable that the blending ratio of the hydroxyl group-containing polyfunctional (meth) acrylate is in the above range because of excellent adhesion retention in a moisture and heat resistant environment.
As the hydroxyl group-containing polyfunctional (meth) acrylate, a 2-methacrylate (meth) acrylic acid adduct of diglycidyl ether is preferable.

  Further, when a hydroxyl group-containing polyfunctional (meth) acrylate is used as the component (B-1), a compound having one (meth) acryloyl group and one or more hydroxyl groups (hereinafter referred to as a hydroxyl group-containing monofunctional (meth) acrylate) Is preferably used in combination because of excellent adhesion performance, in particular, excellent adhesion retention in a humid and heat resistant environment (in a high temperature and high humidity environment).

As component (B-2), monovalent carboxylic acids such as (meth) acrylic acid, crotonic acid and cinnamic acid; divalent carboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid; (meth) acrylic acid (Meth) acrylic acid multimers such as dimer and (meth) acrylic acid trimer; caprolactone ring-opened product of (meth) acrylic acid; acid anhydride adduct of hydroxyalkyl (meth) acrylate and the like. Examples of the hydroxyalkyl (meth) acrylate include compounds similar to those exemplified in the component (B). Examples of the acid anhydride include succinic anhydride, maleic anhydride, phthalic anhydride, and tetrahydrophthalic anhydride. Can be mentioned.
Among these, (meth) acrylic multimer, caprolactone ring-opened product of (meth) acrylic acid, and acid anhydride adduct of hydroxyalkyl (meth) acrylate are excellent in compatibility with component (A), and cured film It is preferable because of its excellent adhesiveness.
The acid anhydride adduct of hydroxyalkyl (meth) acrylate is more preferably a succinic anhydride adduct of hydroxyethyl (meth) acrylate.
Use of the component (B-2) is preferable because the water resistance of the cured product can be improved.

Further, a compound having both a hydroxyl group and a carboxyl group, that is, a compound belonging to both (B-1) and (B-2) may be used.
As such a compound, for example, a compound obtained by adding an acid anhydride to one of hydroxyl groups of a compound having one or more (meth) acryloyl groups and two or more hydroxyl groups. Examples of the acid anhydride include the same compounds as described above.
Specific examples include a succinic anhydride adduct of pentaerythritol di (meth) acrylate, a succinic anhydride adduct of a (meth) acrylic acid 2 mol adduct of glycerin diglycidyl ether, and the like.

  As the component (B), the aforementioned compounds may be used alone or in combination of two or more.

3. Component (C) The component (C) of the present invention is a photoradical polymerization initiator, and various compounds can be used as long as they generate a radical upon irradiation with light. As light, ultraviolet light or visible light is used.
Specific examples of the component (C) include 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane. -1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] 2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, diethoxyacetophenone, oligo {2-hydroxy-2-methyl- 1- [4- (1-methylvinyl) phenyl] propanone} and 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -be Acetophenone compounds such as [zyl] -phenyl} -2-methyl-propan-1-one; benzophenone, 4-phenylbenzophenone, 2,4,6-trimethylbenzophenone, 4-benzoyl-4′-methyl-diphenylsulfide, etc. Benzophenone compounds; methyl benzoylformate, oxy-phenyl-acetic acid 2- (2-oxo-2-phenyl-acetoxy-ethoxy) -ethyl ester and oxy-phenyl-acetic acid 2- (2-hydroxy-) Α-ketoester compounds such as ethoxy) -ethyl ester; thioxanthone compounds such as 2-isopropylthioxanthone and 2,4-diethylthioxanthone; 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2, , 6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, and other phosphine oxide compounds; benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin compounds such as benzoin isopropyl ether and benzoin isobutyl ether; Ji Tanosen compounds; 1- [4- (4-benzoyl) phenyl] -2-methyl-2- (4-methyl-phenylsulfinyl) propane - 1-one acetophenone / benzophenone hybrid photoinitiators; 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)] and other oxime ester-based photoradical weights A combined initiator; and camphorquinone.
(C) As a component, since the compound which has a hydroxyl group is excellent in solubility with (A) and (B) component, it is preferable.

When component (C) is a hydrogen abstraction type photo radical polymerization initiator such as a benzophenone compound or a thioxanthone compound , it is preferable to use a polymerization accelerator.
Specific examples of the polymerization accelerator include ethyl-4- (dimethylamino) benzoate, 2-ethylhexyl-4- (dimethylamino) benzoate, 2- (dimethylamino) ethylbenzoate, poly [oxy (methyl-1,2- Ethanediyl)], α- [4- (dimethylamino) benzoyl-ω-butoxy-], butoxyethyl-4- (dimethylamino) benzoate, triethanolamine, triethylamine, and the like.
As the component (C), the aforementioned compounds may be used alone or in combination of two or more.

  (C) As a compounding ratio of a component, 0.01-10 weight part is preferable with respect to 100 weight part of total amounts of (A) and (B) component, More preferably, it is 0.1-5 weight part. . The amount of 0.01 parts by weight or more is preferable because an effect of initiating polymerization is obtained. Moreover, it is preferable that it is 10 parts by weight or less because good physical properties of the cured product can be obtained and the problem of odor due to the decomposition product of the component (C) does not occur.

4). Other components Although the composition of this invention makes above-described (A)-(C) component essential, the other component mentioned later can also be mix | blended as needed.

The composition of the present invention is preferably blended with an organic solvent and / or water because coating at room temperature becomes possible.
As the organic solvent, those capable of dissolving the component (A) are preferable.
Specifically, monools such as methanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, 2-butanol, amyl alcohol, cyclohexanol and 2-ethylhexanol; ethylene glycol, diethylene glycol, propylene glycol, 1,3 Diols such as butanediol and 1,4-butanediol; alkylene glycol mono, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol monobutyl ether Alkyl ethers; diethylene glycol monomethyl ether, diethylene glycol monoethyl ether Dialkylene glycol monoalkyl ethers such as ter and diethylene glycol monobutyl ether; alkylene glycol monoacetates such as ethylene glycol monoacetate; dialkylene glycol monoacetates such as diethylene glycol monoacetate; diacetone alcohol; lactones such as γ-butyrolactone; ethyl lactate; And N-methyl-2-pyrrolidone and the like.
A preferable blending ratio of the organic solvent and / or water is 20 to 2,000 parts by weight, more preferably 50 to 500 parts by weight with respect to 100 parts by weight of the total amount of the components (A) and (B).

  If necessary, a compound having an ethylenically unsaturated group (hereinafter referred to as other unsaturated compound) other than the component (B) can be blended in the composition of the present invention.

Other unsaturated compounds include (meth) acrylate ((meth) acrylic acid ester), vinyl ether, N-substituted maleimide, N-substituted citraconic imide, N-substituted 3,4,5,6-tetrahydrophthalimide, N- Examples include vinyl pyrrolidone, N-vinyl caprolactone, (meth) acrylamide, and N-substituted (meth) acrylamide.
As other unsaturated compounds, compounds having excellent compatibility with the component (A) are preferable.
Examples of the compound having excellent compatibility with the component (A) include N- (2-hydroxyethyl) maleimide, N- (2-hydroxyethyl) citraconimide, N- (2-hydroxyethyl) dimethylmaleimide, N- Examples include vinyl pyrrolidone, N-vinyl caprolactone, N, N-dimethyl (meth) acrylamide and the like.

  The blending ratio of the other unsaturated compounds is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, still more preferably 10 parts by weight or less with respect to 100 parts by weight of the total amount of the components (A) and (B). is there.

In the present invention, for the purpose of improving the heat-and-moisture resistance performance of the resulting adhesive, a compound that is solid at room temperature having two or more hydrogen-bonding functional groups in one molecule that does not have a (meth) acryloyl group (hereinafter referred to as “a”). , "Solid hydrogen bonding compound"). As the solid hydrogen bonding compound, a compound that is compatible with the component (A) and the component (B) is preferable, and a compound that is not soluble in water is particularly preferable. Specific examples of the hydrogen bonding functional group include a hydroxyl group, a carboxyl group, and an amino group.
Examples of the solid hydrogen bonding compound include shellac, monosaccharide, polysaccharide, trimethylolpropane, pentaerythritol, alkylene oxide adduct of isocyanuric acid, urea, malic acid, tartaric acid and glycine. Of these, shellac is particularly preferable because it has a high effect of enhancing the heat and moisture resistance of the adhesive layer after curing and maintains transparency.
Here, shellac is a natural resin that is extracted from the secretions of the silkworm, and is a water-insoluble resin containing a compound having a hydroxyl group and a carboxyl group as main components. Shellac is a highly safe compound that can be used for food as well as a relatively inexpensive natural resin. When shellac is used, it is preferable to mix an alcohol solvent with the composition of the present invention in order to increase the solubility of shellac.

The mixing ratio of the solid hydrogen bonding compound is preferably 0 to 45 parts by weight with respect to 100 parts by weight of the total amount of the components (A) and (B). It is more preferably 0 to 35 parts by weight.
A blending ratio of 45 parts by weight or less is preferable because good adhesive force can be maintained.

It is possible to add a polymerization inhibitor and / or an antioxidant to the photocurable composition for the adhesive of the present invention, so that the photocurable composition and the photocurable adhesive for the adhesive of the present invention are added. The storage stability of the receiving sheet can be improved, which is preferable.
As the polymerization inhibitor, hydroquinone, hydroquinone monomethyl ether, 2,6-di-tert-butyl-4-methylphenol, and various phenolic antioxidants are preferable. Subsequent antioxidants, clopene antioxidants and the like can also be added.
The total addition amount of these polymerization inhibitors and / or antioxidants is preferably 0.001 to 3 parts by weight, more preferably 100 parts by weight of the total amount of components (A) and (B). 0.01 to 0.5 part by weight.
An addition amount of 0.001 part by weight or more is preferable because of excellent storage stability. Further, if it is 3 parts by weight or less, it is preferable because poor appearance due to bleed-out hardly occurs.
Here, the polymerization inhibitor and / or the antioxidant may be the one added to the product of the component (B), or may be added additionally when blended with the component (A). good.

A silane coupling agent may be added to the composition of the present invention for the purpose of increasing the holding power under high temperature and high humidity conditions or for improving the adhesion performance to inorganic substances such as glass, metal and metal oxide. it can.
Examples of the silane coupling agent include compounds having one or more (meth) acryloyl groups and one or more alkoxysilyl groups in one molecule. Specifically, 3-methacryloxypropyltrimethoxysilane can be exemplified.
A preferable addition amount is 0 part by weight or more and 10 parts by weight or less, and more preferably 0 part by weight or more and 3 parts by weight or less with respect to 100 parts by weight of the total amount of the components (A) and (B). It is preferable for the amount added to be in the above-mentioned range since the adhesive force to an inorganic material such as glass is improved.

The composition of the present invention is dissolved in a polymerizable component and has a molecular weight of 500 in order to increase the toughness of the pressure-sensitive adhesive coating film before photocuring or to relax the strain at the time of curing to improve the adhesiveness. Filling insoluble in the composition of the present invention, such as a polymer having compatibility with the composition of the present invention, transparent ultra-fine dispersed fine particles such as colloidal silica, silica, alumina, talc, clay, etc. An agent can also be blended.
Moreover, the compound which gelatinizes (A) component by solvent drying or heating can also be added, for example, ammonium persulfate etc. can also be added.

In addition to the above, general additives such as light stabilizers such as hindered amine compounds, ultraviolet absorbers such as benzotriazole compounds, antistatic agents, antifoaming agents, wetting agents, and leveling improvers are used in combination. be able to. When an ultraviolet absorber is used, it is preferable to use a compound that generates radicals by visible light as the component (C) of the present invention.
As the antifoaming agent, wetting agent, and leveling agent, various substances such as silicone compounds, fluorine compounds, and hydrocarbon compounds can be used.

5. The present invention relates to (A) a polymer having vinylpyrrolidone as an essential constituent monomer unit and a K value of 20 or more, (B) a (meth) acryloyl group and a hydrophilic group. And (C) a radical photopolymerization initiator, and a weight ratio of (A) component and (B) component ((A) / (B)) is 90/10 to 25/75 The product is used as a photocurable composition for pressure-sensitive adhesives.
That is, the photocurable composition for an adhesive of the present invention is a composition containing the components (A), (B) and (C) as essential components, and the components (A) and (B). The weight ratio ((A) / (B)) is 90/10 to 25/75. The ratio of the component (A) to the component (B) is preferably in the range of (A) / (B) = 80/20 to 35/65.
When the proportion of the component (A) exceeds 90, it becomes impossible to obtain a soft adhesive coating film that can be pasted. On the other hand, if it is less than 25, it becomes closer to a liquid rather than an adhesive coating film. End up.

Examples of the method for producing the composition of the present invention include a method in which essential components are stirred and mixed at a high temperature to dissolve, and in the case of a composition containing an organic solvent and / or water (hereinafter referred to as an organic solvent). And a method of dissolving each component with stirring in an organic solvent.
When the composition of this invention contains the organic solvent etc., since each component can be melt | dissolved and mixed easily, it is preferable on manufacture.

6). Photocurable adhesive sheet The composition of the present invention can be preferably used for the production of a photocurable adhesive sheet.
This item will be described in part based on FIG. 1 and FIG. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted. Various details are possible for the details.
The photocurable adhesive sheet may be produced by a conventional method, for example, by applying a photocurable composition for an adhesive to a substrate.

FIG. 1 shows an example of production of a photocurable adhesive sheet using the photocurable composition for an adhesive of the present invention.
When the photocurable composition 10 for an adhesive of the present invention is a solventless composition (FIG. 1: A1), the composition 10 is heated and applied to the substrate (substrate sheet) 1. . When the photocurable composition 10 for an adhesive of the present invention contains an organic solvent or the like (FIG. 1: A2 (solvent composition), A3 (aqueous composition)), the composition 10 is used as the substrate 1. After coating, the organic solvent is dried to evaporate (FIGS. 1: 1-1, 1-2).
By these methods, a photocurable adhesive sheet B1 in which a photocurable adhesive layer 2 (hereinafter simply referred to as an adhesive layer) is formed on the substrate 1 is manufactured.

The base material may be a material for adhesion (hereinafter referred to as an adherend), or may be a releasable material unrelated to the adherend (hereinafter referred to as a release material).
Examples of the material of the base material include wood, paper, cloth, leather, glass, ceramics, steel plate, aluminum and other metals, metal or metal oxide deposited films, silicon, and polymers.
Examples of the polymer include cellophane, polyester such as polyethylene terephthalate (PET) and polyethylene naphthalate, polyamide, polyimide, polycarbonate, urea / melamine resin, epoxy resin, polyurethane, polylactic acid, polyethylene, polypropylene, cycloolefin polymer, acrylic resin, and methacrylic resin. Examples thereof include resins, polyvinyl chloride, polystyrene, polyvinyl acetate, polyvinyl alcohol, triacetyl cellulose, hydroxypropyl cellulose, polyether sulfone, copolymers of the above polymers, liquid crystal polymers, and fluororesins. As the paper, a paper whose surface is treated with silicone can also be used.
The polymer is preferably a film.
Examples of the release material include non-surface-treated OPP film (polypropylene), silicone-treated PET film, and paper whose surface is silicone-treated.

  The coating amount of the composition of the present invention may be appropriately selected according to the application to be used, but it is preferable to apply the coating so that the film thickness after drying the organic solvent is 0.5 to 500 μm. More preferably, it is 5-50 micrometers.

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

  After the photocurable adhesive sheet B1 is manufactured, it is preferable to laminate the release material 3 as a protective film on the adhesive layer 2 to form a photocurable adhesive sheet B2 laminated with the release material. Moreover, a mold release material can be used as the base material 1 and the mold release material 3 can be laminated on the adhesive layer.

The photocurable adhesive sheet of the present invention can be preferably used for production of a laminate.
As a method for producing a laminate, a photocurable adhesive sheet and an adherend are bonded together, and at least one of the substrate or adherend of the photocurable adhesive sheet is used as a transparent material, A method of irradiating and curing light from the material side can be used.
That is, in the present invention, the laminate production method comprises (A) a polymer having vinylpyrrolidone as an essential constituent monomer unit and a K value of 20 or more, (B) a (meth) acryloyl group and a hydrophilic group. And a composition containing (C) a radical photopolymerization initiator and having a weight ratio of (A) component and (B) component ((A) / (B)) of 90/10 to 25/75. A step of applying to the substrate, a step of drying the composition as necessary to form an adhesive layer, a step of bonding the adhesive layer and the adherend, and a substrate and / or adherend And a step of curing by irradiating light from the transparent material side.

Various light sources can be used as the light source. Suitable light sources include 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 set suitably irradiation conditions, such as irradiation intensity | strength in light irradiation, suitably according to the photocurable composition for adhesives to be used, a base material, the objective, etc.

FIG. 2 shows the use of a light-curing adhesive sheet B2 laminated with a release material (release sheet, release film) 3, and irradiates light from the substrate (substrate sheet) 1 side to form the laminate C. An example of manufacturing is shown.
In FIG. 2, the release material 3 is released from the photocurable adhesive sheet B2 immediately before use (FIG. 2: 2-1), and the adhesive layer 2 and the adherend 4 are brought into close contact (FIG. 2). : 2-2a), light irradiation from the base material (base material sheet) 1 side (FIG. 2: 2-3a), the adhesive layer 2 as the hardened layer 20, and the laminate C (FIG. 2: 2-4a) Is manufactured.

  Here, when bonding a photocurable adhesive sheet and a to-be-adhered body, the adhesive layer or adherend of a photocurable adhesive sheet or a to-be-adhered body can also be apply | coated and bonded together with water. In this method, either the base material (base material sheet) 1 constituting the photocurable adhesive sheet or the adherend 4 to which the photocurable adhesive sheet is attached is made of a material having water absorption and / or moisture permeability (hereinafter referred to as water absorption). -It is preferably applicable to the case of a moisture-permeable substrate. As an advantage of this method, it is possible to easily prevent foam biting when bonding a photocurable adhesive sheet, and to obtain a strong adhesive force when using a water-absorbing / moisture permeable substrate. Can be mentioned.

FIG. 2-2b and subsequent figures (FIGS. 2-2b to 2-4b) in FIG. 2 show an example of laminating in the presence of water when laminating a photocurable adhesive sheet and an adherend.
In FIG. 2, first, the photocurable adhesive sheet adhesive layer 2 and the adherend 4 are laminated with water 5 interposed therebetween (FIG. 2: 2-2b), and the substrate (substrate sheet) 1 Light irradiation is performed from the side (FIG. 2: 2-3b), and the adhesive layer 2 is used as a hardened layer 30 containing water to produce a laminate C ′ (FIG. 2: 2-4b). In this case, the obtained laminate C ′ can be further dried.

  As a method of wetting the adhesive layer or adherend of the photocurable adhesive sheet with water, there are a method of applying water, a method of exposing to minute water droplets in gas, a method of exposing to water vapor, and the like.

As a method of applying water, a method of laminating a photocurable adhesive sheet simultaneously with applying water is preferable.
As water to be used at this time, an aqueous solution can be used in addition to water.
As the aqueous solution, an aqueous solution of a compound that gels the component (A), the composition of the present invention containing water, and the like are preferable.
(A) As a compound which gelatinizes a component, ammonium persulfate, poly (meth) acrylic acid, etc. are mentioned, Polyacrylic acid is especially preferable. The molecular weight of polyacrylic acid is preferably in the range of 500 to 10,000 in terms of weight average molecular weight. The concentration of the polyacrylic acid aqueous solution is not particularly limited, but is preferably 20 to 70% by weight.
As the aqueous solution, it is more preferable to use an aqueous solution of a compound that gels the component (A), since it is particularly excellent in holding power in a high-temperature and high-humidity environment after photocuring.

As a method of exposing to minute water droplets in gas, a method of exposing to fog generated by spraying or the like, or minute water droplets (steam) generated by condensing water vapor generated from boiling water at a temperature of 100 ° C. or lower (for example, room temperature) ) And the like.
Examples of the method of exposing to water vapor include a method of placing the adherend or the photocurable adhesive sheet of the present invention in a high-temperature and high-humidity tank, a method of exposing to high-humidity air generated from a humidifier, and the like.

  In the method of wetting the adhesive layer or adherend of the photocurable adhesive sheet with water, it is most preferable to use an aqueous solution of a compound that gels the component (A) and water vapor.

7). Adhesive Sheet The photocurable composition of the present invention and the above-described photocurable adhesive sheet can be preferably used in the production of an adhesive sheet.
This item will be described in part with reference to FIG.

  The substrate on which the photocurable composition is applied may be an adherend or a release material. Specific examples of the substrate can be the same as described above.

  As the mold release material, a material having low water absorption and moisture permeability is preferable for the purpose of preventing evaporation of moisture. Preferable examples include silicone-treated PET film, polyethylene, polypropylene and the like. Further, in order to enhance the effect of preventing water evaporation, a metal vapor deposition film such as an aluminum vapor deposition film may be used.

The adhesive sheet of the present invention is a sheet having a cured film that does not have tackiness in which a polymerizable component such as the component (B) is polymerized, but the surface is wetted with an organic solvent such as water or alcohol, or these are Adhesion is exhibited by absorption inside.
Here, water is preferable as a material that develops adhesiveness. When this adhesive sheet has water on the surface of the cured film or water is absorbed in the interior, it will cause a slight slime on the surface, or it will show weak adhesion, and can be applied to various substrates. And peeling becomes possible. When water is released by drying after being attached to the base material, it becomes hard and exhibits good adhesive performance with excellent shear strength and holding power.

An example of the preferable manufacturing method of an adhesive sheet is demonstrated based on FIG.
First, using the photocurable adhesive sheet B1 obtained by the above method, the component (B) is cured by irradiating light from the adhesive layer 2 side (FIG. 3: 3-1c), and the cured layer 20 to form, it is possible to produce an adhesive sheet D ₁ of the present invention (FIG. 3: 3-2c). Here, a protective film (not shown) may be stuck on the cured layer 20 to obtain a product. Examples of the protective film include polyolefins such as polyethylene and polypropylene, polyethylene terephthalate or the like as a base material, and a weak adhesive applied on the surface. When this adhesive sheet is affixed to an adherend, the adherend and / or the cured layer 20 is wetted with an organic solvent such as water or alcohol. In this case, water is preferable as the liquid. In this case, as a method of wetting the cured layer 20 with water, the same method as described above can be used. In this case, the cured layer 20 may be wetted with water or the adherend may be wetted with water.
Another form of the adhesive sheet of the present invention is an adhesive sheet D ₂ (FIG. 3: 3-4c, hereinafter referred to as a water-drying type adhesive sheet) obtained by wetting the cured layer 20 with water (FIG. 3: 3-3c). ) If this is necessary to save water dried adhesive sheet is a cured layer 30 which has absorbed water, it is preferable that the release agent 3 was laminated to the adhesive sheet D ₃ (Figure 3: 3-5C).

Next, another example of a preferable method for producing a water-drying type adhesive sheet will be described with reference to FIG.
First, in the production of the photocurable adhesive sheet, the composition (A3) containing water is used as the photocurable composition, and it is not completely dried and is in an intermediate state between the high-viscosity liquid and the adhesive coating film. Either use a dried one (FIG. 3: 3-1a) or use one obtained by absorbing water in the adhesive layer 2 of the photocurable adhesive sheet B1 obtained by the above method ( Fig. 3: 3-1b), laminating the release material 3 (Fig. 3: 3-2a), irradiating light from the release material 3 side to cure the component (B) and forming a cured layer 30 that has absorbed water. (FIG. 3: 3-3a) and adhesive sheet D ₃ (FIG. 3: 3-4a) are manufactured.
In this case, the method similar to the above is mentioned as a method of wetting the adhesive layer 2 with water.

  In the manufacturing example of the adhesive sheet described above (FIG. 3-3a), light is irradiated after the release material is laminated. Advantages include the ability to reduce residual monomers by inhibiting oxygen inhibition of radical polymerization.

The adhesive sheet of this invention can be preferably used for manufacture of a laminated body.
The adhesive sheet of the present invention can be preferably applied when either the substrate (substrate sheet) or the adherend is a water-absorbing substrate. As a method of use, after peeling off the release material, it can be adhered to the adherend by drying the moisture. In the case where the adhesive sheet is sandwiched between the release materials, the two release materials can be peeled off, any two materials can be bonded together, and the moisture can be dried and bonded. As drying conditions, it may be allowed to stand at room temperature for several days, or may be dried at room temperature or higher. The drying temperature and time can be appropriately adjusted.

8). Applications According to the composition of the present invention, it is easy to apply, and a photo-curing adhesive sheet having excellent shear strength and adhesive retention after light irradiation can be produced. Moreover, according to the composition of the present invention, it is easy to apply, and an adhesive sheet having excellent shear strength and adhesive holding force can be produced after application and drying. In addition, all the adhesive sheets have the external appearance excellent in colorless transparency.
From the above features, the photo-curable adhesive sheet and adhesive sheet of the present invention are used for the manufacture of building materials such as wallpaper, laminated plywood and crime prevention glass, the manufacture of window glass with UV cut filters for automobiles, etc. Manufacturing of various protective films such as protective films, bonding of labels to beverage bottles, cans, bottles, bonding of exhibits to show windows, bonding of display members such as projection televisions, and electric circuits It can be suitably used for bonding various materials and members such as bonding of laminated plates to be used.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, this invention is not limited by these Examples.
In the following, “parts” means parts by weight.

<Abbreviations in Examples and Comparative Examples>
The meanings of the abbreviations in Examples and Comparative Examples are described below.
○ (A) component PVP-K90: Polyvinylpyrrolidone, manufactured by ISP, PVP K-90 (K value 90)
-PVP-K30: Polyvinylpyrrolidone, manufactured by ISP Co., Ltd., PVP K-30 (K value 30)
S-630: VPVA copolymer, manufactured by ISP, S-630 (vinyl pyrrolidone 60 mol%, K value 36)

○ (A) 'component PVP-K15: Polyvinylpyrrolidone, manufactured by ISP Co., Ltd., PVP K-15 (K value 15)

○ (B) component · GLM: Glycerin monomethacrylate, manufactured by NOF Corporation, Blemmer GLM
PE-90: Polyethylene glycol monomethacrylate, manufactured by NOF Corporation, Bremer PE-90 (average number of ethylene glycol repeats 2)
400EA: Polyethylene glycol diglycidyl ether acrylic acid 2 mol adduct, manufactured by Kyoeisha Chemical Co., Ltd., epoxy ester 400EA (average number of ethylene glycol repeats 9)
・ 80MFA: 2 mol of acrylic acid adduct of glycerin diglycidyl ether, manufactured by Kyoeisha Chemical Co., Ltd., epoxy ester 80MFA
M-5600: Acrylic acid dimer, manufactured by Toagosei Co., Ltd., Aronix M-5600

○ (C) component Irg2959: 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, manufactured by Ciba Specialty Chemicals Co., Ltd., Irgacure 2959

○ Other components M245: Polyethylene glycol diacrylate, manufactured by Toagosei Co., Ltd., Aronix M-245 (average number of ethylene glycol repeats 9)
KBM503: 3-methacryloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503
-PGM: Propylene glycol monomethyl ether-Shellac: White rack GBN-D, manufactured by Gifu Seratech Co., Ltd.

<Example 1 to Example 14, Comparative Example 1, Comparative Example 2>
Preparation of composition The components shown in Tables 1 to 3 were stirred and mixed according to a conventional method to prepare a composition for a photocurable adhesive.
As a blending procedure, first, polyvinylpyrrolidone was dissolved in an organic solvent, and then other components were added and stirred and mixed. In addition, the numerical value of the compounding composition in a table | surface represents a weight part.
Using the obtained composition, a photocurable adhesive sheet was produced according to the method described later, and the adhesive film was evaluated. Furthermore, adhesiveness was evaluated.

○ Manufacture of photo-curing type adhesive sheet Easy-adhesion PET film (Toyobo Co., Ltd., Cosmo Shine A4300, film thickness 125 μm, hereinafter simply referred to as easy-adhesion PET) After coating with an applicator so that the film thickness was about 15 μm, it was dried at 70 ° C. for 3 minutes to obtain a photocurable adhesive sheet having an adhesive coating film (adhesive layer). Next, a release film (siliconized PET film) was laminated on the surface of the adhesive coating film.
The obtained photocurable pressure-sensitive adhesive sheet was evaluated for sticking fixability, release film soiling and peelability to glass according to the following methods. The results are shown in Table 4.

-Sticking fixability The obtained photocurable adhesive sheet was peeled off from the release film and attached to glass immediately before use.
At this time, those that were fixed without slipping were marked with ◯.
On the contrary, the case where it was liquid or the liquid bleeded out to the surface and could not be fixed by sliding was evaluated as x.

● Release film stains When the release film was peeled off, the case where there was no stain such as liquid adhering to the release film side was evaluated as ○, and the case where there was such a stain was evaluated as ×.

● Removability to glass When a photo-curing adhesive sheet from which a release film has been peeled off is once attached to glass and then peeled off, some of those that can be peeled cleanly from the glass without tearing the adhesive film What was torn and remained in the glass was evaluated as x.

○ Manufacture of laminates (Evaluation of adhesion between easy-adhesion PET and glass)
The obtained photo-curable adhesive sheet is cut into a 1 cm × 4 cm strip, the release film (release material) is peeled off, and the adhesive part of the adhesive film surface is 1 cm × 1 cm. , Pasted on a slide glass.
Then, 60W / cm high-pressure mercury lamp with a parallel light cold mirror manufactured by Eye Graphics Co., Ltd. (lamp height 30 cm, illuminance meter “UV POWER PUCK” manufactured by Fusion Co., Ltd., illuminance of 100 mW / cm ^{2 in} the UV-A region) Thus, the glass body was irradiated with ultraviolet rays for 30 seconds (irradiation energy was 3,000 mJ / cm ² ) and cured to produce a laminate.
According to the following method, the obtained laminate was evaluated for shear adhesive strength and adhesive retention strength under heat and humidity heat resistance environments. The results are shown in Table 4.

-Shear adhesive strength The shear adhesive strength of the obtained laminate was measured using an Instron 5560 manufactured by Instron Co., Ltd. at a tensile speed of 10 mm / min.

● Adhesive retention in heat and moisture resistant environments In order to suspend and hold a weight on the obtained laminate, 2.5 cm wide adhesive PET is attached to both ends of the laminate with an adhesive. A hole was made in the adhesive PET. Subsequently, it was suspended by the hook at the fall time measuring device set in the constant temperature and humidity chamber. Thereafter, 85 ° C. for the heat resistance test, and 60 ° C. 90% R.D. H. After holding for 30 minutes in this environment, a 1 kg weight was suspended and the drop time was measured.

<Comparative Example 3>
Easy-adhesive PET is cut into 1cm x 4cm strips, and a double-sided tape for general use (acrylic adhesive, product number W621P03) manufactured by Sekisui Chemical Co., Ltd. is used to attach a release film so that the adhesive part is 1cm x 1cm In the same manner as in Example 1, evaluation as an adhesive coating film (sticking fixability, release film dirt and peelability to glass) was performed.
In the same manner, the above-mentioned double-sided tape attached to easy-adhesive PET was attached to a slide glass, and the adhesion was evaluated in the same manner as in Example 1.
Table 4 shows the obtained results.

<Comparative example 4>
Evaluation was performed in the same manner as in Comparative Example 3 except that the double-sided tape was changed to Sumitomo 3M Co., Ltd. Scotch transparent double-sided tape (acrylic adhesive, product number 665-1-18).
Table 4 shows the obtained results.

<Comparative Example 5>
Preparation of composition 45 parts of 2-ethylhexyl acrylate, 30 parts of N-vinylpyrrolidone, 25 parts of bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., EP-828), Ciba Specialty Chemicals Co., Ltd. ) Photoradical polymerization initiator Irgacure 1700 (bis (2,6-dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide and 2-hydroxy-2-methyl-1-phenyl-propane-1- 0.4 parts of a 1: 3 mixture of ON, hereinafter referred to as Irg-1700), photocationic polymerization initiator Adekaoptomer SP-170 (triarylsulfonium hexafluoroantimonate, hereinafter SP) manufactured by Asahi Denka Kogyo Co., Ltd. -170) was mixed and stirred and mixed to prepare a composition.

○ Manufacture of photo-curing adhesive sheet After nitrogen bubbling was applied to this composition, it was applied to easy-adhesive PET with a bar coater to a film thickness of about 15 μm, and a release film (siliconized PET) was laminated. . Next, an 80 W / cm metal halide lamp manufactured by Eye Graphics Co., Ltd. was irradiated through the PET film that cuts off ultraviolet rays until the composition was in an adhesive state, to obtain a photocurable adhesive sheet.
Evaluation similar to Example 1 was performed with respect to this photocurable adhesive sheet.

-Manufacture of a laminated body The obtained photocurable adhesive sheet was used, the laminated body was manufactured by the method similar to Example 1, and adhesiveness evaluation was performed by the method similar to Example 1. FIG.
Table 4 shows the obtained results.

<Comparative Example 6>
20 parts hydroxy group-containing monofunctional methacrylate (2-hydroxyethyl methacrylate caprolactone adduct (average number of moles added 2), Daicel Chemical Industries, Plaxel FM-2D), 30 parts tetrahydrofurfuryl methacrylate, hydrogenated 50 parts of bisphenol A type epoxy resin (Japan Epoxy Resin Co., Ltd., YX-8000, epoxy equivalent of 205 g / eq), 0.1 part of Irg-1700, 0.5 part of SP-170 and blended with stirring. Thus, a composition was prepared.

○ Manufacture of photo-curing adhesive sheet After nitrogen bubbling was applied to this composition, it was applied to easy-adhesive PET with a bar coater to a film thickness of about 15 μm, and a release film (siliconized PET) was laminated. .
Next, a 60 W / cm high-pressure mercury lamp with a parallel light cold mirror (lamp height: 30 cm) manufactured by iGraphics Co., Ltd. is irradiated through the PET film that cuts ultraviolet rays until the composition is in an adhesive state. A curable adhesive sheet was obtained.
Evaluation similar to Example 1 was performed with respect to this photocurable adhesive sheet.

-Manufacture of a laminated body The obtained photocurable adhesive sheet was used, the laminated body was manufactured by the method similar to Example 1, and adhesiveness evaluation was performed by the method similar to Example 1. FIG.
Table 4 shows the obtained results.

<Example 15 and Example 16>
Using the components shown in Table 3, compositions of Example 15 and Example 16 were prepared in the same manner as in Example 1. In Example 16, water was used instead of the organic solvent (ethanol).

<Example 17>
○ Production of photocurable adhesive sheet The composition of Example 15 was applied to easy-adhesive PET with an applicator so that the film thickness after solvent drying was about 15 μm, and then dried at 70 ° C. for 10 minutes. Thus, a photocurable adhesive sheet was obtained.

○ Production of Adhesive Sheet Next, the composition of Example 16 which is an aqueous solution was hung on one end of the obtained photo-curing adhesive sheet, and separated from the top while applying pressure with a roller so as to extend from the end. A mold film was laminated (corresponding to performing 3-1b and 3-2a in FIG. 3 simultaneously).
Next, it is cured by irradiating ultraviolet rays through a release film (silicon-treated PET of about 40 μm thickness) for 1 minute with a 60 W / cm high-pressure mercury lamp (lamp height: 30 cm) with a parallel light cold mirror manufactured by IGraphics. An adhesive sheet was obtained. Since this adhesive sheet contains water, it was in the form of a sticky coating.
About the obtained adhesive sheet, according to the method similar to Example 1, evaluation (adhesion fixing property, mold release film dirt, and peelability to glass) as an adhesive coating film was performed.

-Manufacture of a laminated body The release film was peeled off from the obtained adhesive sheet, and after attaching to a slide glass, it dried at 60 degreeC for 15 hours, and manufactured the laminated body. About the obtained laminated body, adhesiveness evaluation was performed by the method similar to Example 1. FIG.
Table 4 shows the obtained results.

<Example 18>
In the manufacturing process of the adhesive sheet of Example 17, when the release film was laminated, the aqueous solution intervened at the interface was changed from the composition of Example 16 to a polyacrylic acid aqueous solution (weight average molecular weight 6,000, solid content 40% by weight). The adhesive sheet was produced in the same manner as in Example 17 except that the composition was changed to) and evaluated in the same manner as in Example 17.
Using the obtained adhesive sheet, a laminate was produced in the same manner as in Example 17, and evaluated in the same manner as in Example 1.
Table 4 shows the obtained results.

<Example 19>
The photocurable adhesive sheet obtained in Example 17 was used.
The photocurable adhesive sheet was exposed to steam from water boiled in a water bath for 1 minute (corresponding to 3-1b in FIG. 3), and then a release film was laminated (3-2a in FIG. 3). Equivalent to.)
Thereafter, an adhesive sheet was produced in the same manner as in Example 17, and evaluated in the same manner as in Example 17.
Using the obtained adhesive sheet, a laminate was produced in the same manner as in Example 17, and evaluated in the same manner as in Example 1.
Table 4 shows the obtained results.

<Example 20>
○ Production of photocurable adhesive sheet After the composition of Example 3 was applied to the untreated surface of an OPP (stretched polypropylene) film with an applicator so that the film thickness after solvent drying was about 15 μm, It was made to dry at 70 degreeC for 3 minute (s), the release film (silicone processing PET film) was laminated on the surface, and the photocurable adhesive sheet was obtained.
○ Manufacture of Laminate This photo-curing type adhesive sheet was cut into a 1 cm square, the release film was peeled off and attached to a slide glass, the OPP film was peeled off, and another slide glass was attached to this surface. . 23 ° C. 65% R.D. H. After being allowed to stand in an environment of 1 night, a 60 W / cm high-pressure mercury lamp with a parallel light cold mirror (lamp height: 30 cm) irradiated with UV rays for 30 seconds is cured and bonded to produce a laminate. did.
The shear adhesive strength of the laminate was measured at a speed 10 mm / min tensile by Instron 5560 was ^{930N / cm 2 (95kgf / cm} 2).

From the results of Examples 1 to 19, the photocurable pressure-sensitive adhesive sheet or adhesive sheet obtained from the composition of the present invention is excellent in stickability, and the laminate obtained by photocuring or drying water is: It exhibited excellent adhesiveness in terms of shear adhesive strength, heat resistance retention, and moisture and heat resistance.
In contrast, a composition containing no component (B) (Comparative Example 1) or a composition using a polyvinyl pyrrolidone having a K value less than 20 different from the component (A) of the present invention (Comparative Example 2). The photo-curing type adhesive sheet or adhesive sheet obtained from No. 1 was insufficient in various performances of the adhesive coating film and also had insufficient moisture and heat resistance for adhesion evaluation. Moreover, although the commercially available adhesive (Comparative Examples 3-4) was excellent in the performance of the adhesive coating film, all the adhesive forces of adhesive evaluation were inadequate. In addition, the photocationically polymerizable adhesive composition (Comparative Examples 5 to 6) has insufficient adhesive strength for adhesive evaluation as well as insufficient adhesion of the adhesive coating film to glass. Met.
Further, from the results of Examples 5 to 7, compositions (Examples 5 and 6) containing a hydroxyl group-containing polyfunctional (meth) acrylate as the component (B) are preferable in terms of excellent moist heat resistance, The composition (Example 6) containing a hydroxyl group-containing monofunctional (meth) acrylate was more preferable.
Furthermore, from Example 8 and Example 9, as the composition (Example 8) having a larger K value of the component (A), the adhesive coating film was more difficult to tear, and the heat and moisture resistance after adhesion was excellent. .
Examples 17 to 19 are adhesive sheets produced by adding water to the dried coating film and photocuring it, and these also had excellent performance as an adhesive.
Among these examples, Example 18 containing a polyacrylic acid aqueous solution that gels the component (A) was particularly excellent in moisture and heat resistance. Further, in Example 19 in which water was absorbed from water vapor (steam), there was an advantage that the process was simple, and the workplace was not soiled by the protrusion of water.
Finally, the laminates and adhesive sheets obtained in the examples both had an appearance with excellent colorless transparency.

<Examples 21-33, Comparative Example 7>
Preparation of composition Using the components shown in Tables 5 and 6, compositions were prepared in the same manner as in the above Examples.
Using the obtained composition, an adhesive sheet was produced in accordance with the method described later, and the sticking property with water to the glass plate and the outdoor exposure durability and removability were evaluated.

○ Manufacture of adhesive sheet Apply the obtained composition to a 50 μm thick easy-adhesion-treated PET film (Toyobo Co., Ltd., Cosmo Shine A4300) with an applicator so that the film thickness after drying is about 15 μm. The mixture was dried for 5 minutes in a dryer at 70 ° C., and then cooled to room temperature.
Then, it was cured by UV irradiation under the conditions of 80 W / cm high-pressure mercury lamp (with a parallel light cold mirror), lamp height of 30 cm, conveyor speed of 3 m / min, and 3 passes to prepare an adhesive sheet.
The above adhesive sheet was not sticky at room temperature.

● Evaluation of Adhesiveness of Water to Glass Plate Adhesive sheets of Examples 21 to 33 and Comparative Example 7 were cut into 5 cm × 10 cm and used as test specimens. After water was sprayed on the glass plate, a test specimen was attached thereto (corresponding to 3-4c in FIG. 3).
About the sticking property at this time, according to the following method, the peelability at the time of adhesion surface contact and adhesion slide property were evaluated. The results are shown in Table 7.
Thereafter, excess water inside was expelled from the end of the film while rubbing the upper surface of the film with tissue paper. Subsequently, it was left to dry in the room for 2 weeks to complete the adhesion.

・ Peelability when contacting the adhesive surface ○ Even if the adhesive surfaces of the adhesive sheet touch each other, it can be peeled lightly without giving any change in appearance to the adhesive surface. Was evaluated as x.
-Adhesive slide property In the state where water is present between the glass and the adhesive surface, the case where the pasting position can be fine-adjusted while sliding is indicated as ◯, and the case where it cannot be indicated as X.

● Evaluation of outdoor exposure durability and removability Table 7 shows the results of evaluation as follows.

-Appearance transparency The above-mentioned adhesive was exposed to the rooftop of a building in Nagoya City for two months while keeping the film side as an upper surface at an angle of 45 degrees. In addition, there was rainfall for 9 days in the 2 weeks in the initial stage of the test. After that, there were a total of 7 days of rain. In this outdoor exposure test, those that maintained transparency even during rainfall were evaluated as ◯, and those that were whitened were evaluated as ×.
-Adhesive durability: The peeling at the end after 2 months of outdoor exposure is within 1 cm at the maximum, and the area where the peeled area was 5% or less of the whole ○, 5-10% peeled △ 10% What peeled above was evaluated as x.
・ Evaluation of removability by water immersion The adhesive after 2 months of outdoor exposure is immersed in water overnight, peeled off easily with little force, and the adherend after peeling was clean. △ △ indicates that the adherend after peeling was clean but required some force, △ indicates that the adherend was dirty but the adherend was dirty, and × indicates that the adherend was not peelable did.

● Evaluation of adhesive strength The results are shown in Table 7 after evaluation as follows.
The adhesive sheets of Examples 21 to 33 and Comparative Example 7 were cut into 1-inch strips, attached to glass using water as described above, and dried indoors for 2 weeks. Thereafter, a 180 ° peel test was performed.
At this time, PET was broken from the edge because the adhesive strength was too strong, and it was impossible to peel off. ○ a, the one that was peelable once and the adhesive strength of 10N or more was obtained. ○ b, peeled without material destruction, but peel strength of 5N or more ○ c, peel strength 1-5N, Δ, peel strength 0.2-1N X and those having a peel strength of less than 0.2 were evaluated as xx.

  As shown in Table 7, the adhesive sheet of the present invention can be peeled off without soiling the adhesive surfaces when the adhesive surfaces touch each other at the time of pasting, and is also slid in the pasted position. It is also possible to combine them. Further, the adhesive strength after the water has dried is very strong, and it has durability that hardly peels even when exposed to the outdoors for 2 months from the rainy season. However, when it is immersed in water overnight, it can be easily peeled off, and there is also a feature that no adhesive layer remains on the adherend.

The composition of this invention can be used for manufacture of a photocurable adhesive sheet and an adhesive sheet. Moreover, the photocurable adhesive sheet of this invention can be used for manufacture of a laminated body and an adhesive sheet. Furthermore, the adhesive sheet of this invention can be used for manufacture of a laminated body.
More specifically, the photocurable pressure-sensitive adhesive sheet and adhesive sheet of the present invention can be used for the various applications described above.

Claims (10)

(A) a polymer having vinylpyrrolidone as an essential constituent monomer unit and a K value of 20 or more,
(B) a compound having a (meth) acryloyl group and a hydrophilic group, and
(C) containing a photo radical polymerization initiator,
The weight ratio ((A) / (B)) of the component (A) and the component (B) is 90/10 to 25/75,
(1) (B) component contains (B-1) diglycidyl ether (meth) acrylic acid 2-mol adduct, and (B-1) component content is the total of (A) component and (B) component 1 part by weight or more and 50 parts by weight or less with respect to 100 parts by weight, or
(2) Component (B) is selected from the group consisting of (B-2) (meth) acrylic acid multimer, caprolactone ring-opened product of (meth) acrylic acid, and acid anhydride adduct of hydroxyalkyl (meth) acrylate. A photocurable composition for adhesives, comprising at least one. The photocurable composition for adhesives according to claim 1, wherein in (2), the (B- 2 ) component is a (meth) acrylic acid multimer. The photocurable composition for adhesives according to claim 1 or 2 , wherein the component (A) is a vinylpyrrolidone homopolymer or a copolymer of vinylpyrrolidone and vinyl acetate. Furthermore, the photocurable composition for adhesives as described in any one of Claims 1-3 containing an organic solvent and / or water. A photocurable adhesive sheet, wherein the composition according to any one of claims 1 to 4 is applied to a substrate and dried as necessary to form an adhesive layer. . The substrate and / or the adherend is made of a transparent material, the photocurable adhesive sheet according to claim 5 and the adherend are bonded together, and the substrate is obtained by curing by irradiating light from the transparent material side. A laminate characterized by the following. The laminate according to claim 6 , wherein when the photocurable adhesive sheet and the adherend are bonded together, the photocurable adhesive sheet and / or the adherend is wetted with water. A sheet produced from the photocurable adhesive sheet according to claim 5 and a release material, wherein the adhesive layer is wetted with water, and is then brought into close contact with the release material and irradiated with light to form a cured film. An adhesive sheet. An adhesive sheet obtained by irradiating the adhesive layer of the photocurable adhesive sheet according to claim 5 with light to form a cured film. 6. An adhesive sheet obtained by irradiating the adhesive layer of the photocurable adhesive sheet according to claim 5 with light to form a cured film, and then wetting the cured film layer with water.

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