JP6106355B2 - Active energy ray-curable adhesive composition for plastic film or sheet - Google Patents

Description

The present invention relates to an active energy ray-curable adhesive composition capable of adhering various plastic films or sheets by irradiation with active energy rays such as electron beams or ultraviolet rays, and the composition of the present invention. Is suitable for use in the production of various optical films or sheets used for liquid crystal display elements, etc. It can be used in the field.
In the present specification, acrylate and / or methacrylate is represented by (meth) acrylate, acryloyl group and / or methacryloyl group is represented by (meth) acryloyl group, and acrylic acid and / or methacrylic acid is represented by (meth) acrylic acid. .
In the following description, unless otherwise specified, a plastic film or sheet is collectively expressed as “plastic film or the like”, and a film or sheet is collectively expressed as “film or the like”.

Conventionally, in a laminating method in which a thin-layer adherend such as a plastic film or a thin-layer adherend such as a plastic film and a thin-layer adherend made of another material are bonded together, an ethylene-vinyl acetate copolymer is used. A solvent-type adhesive composition containing a polymer or a polyurethane-based polymer is applied to the first thin-layer adherend and dried, and then the second thin-layer adherend is applied to the first thin-layer adherend using a nip roller or the like. The dry laminating method for pressure bonding is mainly performed.
The adhesive composition used in this method generally contains a large amount of a solvent in order to make the coating amount of the composition uniform, but for this reason, a large amount of solvent vapor is volatilized during drying, resulting in toxicity, work safety and Environmental pollution is a problem. In addition, the adhesive composition is a thin layer in a post-processing step such as a heat seal for bonding the obtained laminate film and a ruled line step for engraving grooves immediately after the thin layer adherend is bonded. There is a problem that the adherends are separated from each other.
As an adhesive composition for solving these problems, a solventless adhesive composition has been studied.

As the solventless adhesive composition, a two-component adhesive composition and an adhesive composition that is cured by an active energy ray such as an ultraviolet ray or an electron beam are widely used.
As the two-component adhesive composition, a so-called polyurethane adhesive composition is mainly used in which a polymer having a hydroxyl group at the terminal is a main agent and a polyisocyanate compound having an isocyanate group at the terminal is a curing agent. However, the composition has a drawback that it takes a long time to cure, and thus there is a problem in productivity such as being unable to enter a post-processing step such as a ruled line step immediately after laminating the thin layer adherend. .
On the other hand, the active energy ray-curable adhesive composition is excellent in productivity because of its high curing rate, and has recently attracted attention.

On the other hand, liquid crystal display devices are widely used in navigation systems for automobiles, small electronic devices such as mobile phones and PDAs, screens of word processors and personal computers, and even television receivers because of their features such as thinness, light weight, and low power consumption. doing.
In recent years, an active energy ray-curable adhesive has been used for bonding various optical films and the like used in the liquid crystal display element.

  Examples of the optical film include a polarizing plate, a retardation film, a viewing angle compensation film, a brightness enhancement film, an antireflection film, an antiglare film, a lens sheet, and a diffusion sheet, and various types of plastics are used. It has been.

  Among these plastics, polyvinyl alcohol, a polyvinyl alcohol resin that includes polyvinyl alcohol, a part of which vinyl acetate remains, or a part of which is butyralized, and triacetyl are particularly used for polarizing plates. A cellulose is mentioned. These plastics contain a hydroxyl group and are characterized by being very hydrophilic compared to ordinary plastics.

  As active energy ray-curable adhesive compositions for polarizing plates, compositions using photo radical polymerization, compositions using photo cation polymerization, and compositions using both photo radical polymerization and photo cation polymerization are known. Yes.

As an active energy ray-curable adhesive composition using photo radical polymerization, a composition containing a radical polymerizable compound containing a hydroxyl group and the like and a radical polymerizable compound not containing a polar group in a specific ratio (Patent Document 1), etc. It has been known.
However, the composition has a large shrinkage during curing, and depending on the type of adherend, it has been difficult to obtain sufficient peel strength due to the generation of stress at the interface.
Moreover, in order to solve this problem, the composition containing urethane (meth) acrylate and an acrylamide derivative is examined (for example, patent document 2 etc.).
However, the composition has a problem that water resistance and heat-and-moisture resistance that are practically required are insufficient although the initial adhesive force to the hydrophilic plastic is high. It is also possible to reduce the shrinkage stress during curing by improving the flexibility of the adhesive composition. However, since such a means lowers the heat resistance and water resistance of the adhesive, There is a problem that defects such as peeling, foaming, and cracks occur in applications that require high performance.

Examples of the active energy ray-curable adhesive composition using cationic photopolymerization include a composition mainly composed of an epoxy resin not containing an aromatic ring (Patent Document 3), an aliphatic epoxy compound, an alicyclic epoxy, and / or Or the composition (patent document 4) etc. containing an oxetane are known.
The composition has an advantage in that the generation of stress at the interface can be suppressed because the shrinkage at the time of curing is relatively small compared to the composition using photo radical polymerization.
However, photocationic polymerization is generally known to cause polymerization inhibition due to moisture and basic substances. In high humidity environments, substrates with a lot of moisture, and substrates with a basic surface. It was difficult to obtain sufficient peel strength. In addition, by using a composition containing a polyfunctional epoxy resin as a main component, it is possible to reduce the effect of curability reduction due to polymerization inhibition. There is a problem that the stress between the substrate and the base material becomes high and the adhesive force becomes insufficient.

  The active energy ray-curable adhesive composition using both photoradical polymerization and photocationic polymerization includes (meth) acrylate having an isocyanuric ring skeleton, alicyclic epoxy compound, a compound containing a hydroxyl group, and a photoacid generator. Composition (Patent Document 5) An epoxy resin having two or more epoxy groups, at least one of which is an alicyclic epoxy group, having two or more epoxy groups and an alicyclic epoxy Composition having an epoxy resin having no group, a cationic photopolymerization initiator and a polymerizable monomer (Patent Document 6), a compound having two or more (meth) acryl groups, a hydroxyl group and one (meth) acryl group Known is a compound, a cationic polymerizable compound having a (meth) acrylic group, a radical photopolymerization initiator and a composition containing a cationic photopolymerization initiator (Patent Document 7). That.

  These compositions are intended to solve the problem of shrinkage at the time of curing and polymerization inhibition due to moisture by hybridization using photo radical polymerization and photo cationic polymerization. It turned out that there was a problem as shown.

  The composition disclosed in Patent Document 5 contains a (meth) acrylate compound having an isocyanuric ring skeleton as an essential component, but according to the study by the present inventors, a bifunctional photoradically polymerizable compound is composed. When it is contained in a large amount, the shrinkage at the time of curing is not so small and stress generation at the interface cannot be suppressed. For this reason, it has been found that it is difficult to obtain sufficient peel strength depending on the substrate. .

  The composition disclosed in Patent Document 6 is described in the specification to include a hybridized composition as a concept, but in the examples, the composition is composed only of a photocationically polymerizable monomer. Only the thing is shown and lacks concreteness.

  The composition disclosed in Patent Document 7 contains a cationically polymerizable compound having a (meth) acrylic group as an essential component at a specific ratio, but according to the study by the present inventors, the compound is contained in the composition. If it is contained in a large amount, the shrinkage at the time of curing is not so small and the generation of stress at the interface cannot be suppressed, and it has been found that it is difficult to obtain a sufficient peel strength depending on the substrate.

JP 2008-009329 A (Claims) JP 2007-177169 A (Claims) JP-A-2004-245925 (Claims) JP 2008-134384 A (Claims) JP 2008-233279 A (Claims) JP 2008-257199 A (Claims) JP 2008-260879 A (Claims)

  The present invention has been made in view of the above problems, has low viscosity and excellent curability, has excellent adhesion to various plastic films, particularly hydrophilic plastic films, etc., and is sufficient for applications that require strict durability. Specifically, an object of the present invention is to provide an active energy ray-curable adhesive composition for a plastic film or the like that can maintain high adhesive force even under high temperature and high humidity conditions. .

As a result of various studies, the present inventors have found that a urethane (meth) acrylate, a compound having a carboxyl group and an ethylenically unsaturated group, a compound having a phosphate group and an ethylenically unsaturated group, an aliphatic or alicyclic skeleton And an active energy ray-curable adhesive composition containing a compound having an ethylenically unsaturated group and a photopolymerization initiator have excellent adhesion to various plastic films, especially hydrophilic plastic films, and require strict durability. The present invention has been completed by finding that it has sufficient performance even in applications to be used.
Hereinafter, the present invention will be described in detail.

  The composition of the present invention is low in viscosity and excellent in coating properties, and can maintain high adhesive force on various plastic films and the like, particularly hydrophilic plastic films and the like even under high temperature and high humidity conditions. It is effective for adhesion of a thin layer adherend such as a film, and can be suitably used for producing an optical film used particularly for a liquid crystal display device or the like.

The present invention includes the following (A) to (E) components as essential components, and optionally includes the following (F) components and the following (A) to (F) components in the following proportions: The present invention relates to an active energy ray-curable adhesive composition for sheets.
(A) Urethane (meth) acrylate (hereinafter referred to as “component (A)”): 10 to 70% by weight in the curable component
(B) Compound having carboxyl group and ethylenically unsaturated group (hereinafter referred to as “component (B)”): 3 to 30% by weight in the curable component
(C) Compound having phosphoric acid group and ethylenically unsaturated group (hereinafter referred to as “component (C)”): 0.1 to 15% by weight in the curable component
(D) Compound having aliphatic group or alicyclic skeleton and ethylenically unsaturated group (hereinafter referred to as “component (D)”): 5 to 45% by weight in the curable component
(E) Photoradical polymerization initiator (hereinafter referred to as “component (E)”): 0.1 to 20 parts by weight relative to 100 parts by weight of the total amount of curable components
(F) Compounds having an ethylenically unsaturated group other than the components (A) to (D): 0 to 30% by weight in the curable component
In addition, a sclerosing | hardenable component means (A)-(D) component, when a composition does not contain ( F) component, and when it contains ( F) component, (A)-(D) and (F) means a component.
Hereinafter, the essential components (A) to (E) will be described.

1. (A) Component (A) A component is urethane (meth) acrylate. In this invention, by containing (A) component, the hardened | cured material obtained will be excellent in adhesive force in any conditions of high temperature or high humidity.
As the component (A), both oligomers and polymers can be used, and those having a weight average molecular weight (hereinafter abbreviated as “Mw”) of 500 to 50,000 are preferable, and 3,000 to 40,000 are more preferable. belongs to.
In the present invention, Mw means a value obtained by converting the molecular weight measured by gel permeation chromatography into polystyrene.

As the component (A), various compounds can be used, and examples thereof include compounds obtained by reacting a hydroxyl group-containing (meth) acrylate with a compound having an isocyanate group obtained by reacting a polyol and an organic polyisocyanate.
Furthermore, the component (A) is preferably a urethane (meth) acrylate having two (meth) acryloyl groups [hereinafter referred to as a bifunctional urethane (meth) acrylate].

Examples of the polyol include a polyol having a polyether skeleton, a polyol having a polyester skeleton, and a polyol having a polycarbonate skeleton.
Examples of the polyol having a polyether skeleton include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.
Examples of the polyol having a polyester skeleton include an esterification reaction product of a diol such as a low molecular weight diol or polycaprolactone diol and an acid component such as a dibasic acid or an anhydride thereof.
Examples of the low molecular weight diol include ethylene glycol, propylene glycol, cyclohexanedimethanol, 3-methyl-1,5-pentanediol, and 1,6-hexanediol.
Examples of the dibasic acid or an anhydride thereof include adipic acid, succinic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid and terephthalic acid, and anhydrides thereof.
Examples of the polycarbonate polyol include a reaction product of the low molecular weight diol or / and bisphenol such as bisphenol A and a carbonic acid dialkyl ester such as ethylene carbonate and carbonic acid dibutyl ester.

  Organic polyisocyanates include tolylene diisocyanate, 1,6-hexane diisocyanate, 4,4′-diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, 1,6-hexane diisocyanate trimer, hydrogenated tolylene diisocyanate, hydrogenated 4 , 4'-diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, paraphenylene diisocyanate, tolylene diisocyanate dimer, 1,5-naphthalene diisocyanate, hexamethylene diisocyanate interadduct, 4,4'-dicyclohexylmethane diisocyanate , Trimethylolpropane tris (tolylene diisocyanate) adduct, isophorone diisocyanate and the like. The organic polyisocyanate is preferably an organic diisocyanate.

  As the hydroxyl group-containing (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxypentyl (meth) acrylate, hydroxyhexyl (meth) acrylate, hydroxy Examples include octyl (meth) acrylate, pentaerythritol tri, di or mono (meth) acrylate, and hydroxyalkyl (meth) acrylate such as trimethylolpropane di or mono (meth) acrylate.

As the method for producing the component (A), in the presence of an addition catalyst such as dibutyltin dilaurate, a polyol and an organic polyisocyanate are heated and stirred for addition reaction, and a hydroxyalkyl (meth) acrylate is further added, and heated and stirred for addition reaction. Can be obtained.
As the component (A), these compounds may be used alone or in combination of two or more.

As the component (A), an ester is particularly excellent in that the adhesive strength under high humidity is excellent, and the adhesive strength after curing is small due to a change in viscosity of the composition over time or a change in viscosity. A bifunctional urethane (meth) acrylate having a polyether skeleton produced by using a polyol having a polyether skeleton as a polyol and having no bond is preferable.
Furthermore, as (A) component, it is bifunctional urethane (meth) acrylate which has polyether skeleton, Comprising: Mw is 3,000-40,000, More preferable.

(A) The content rate of a component is 10 to 70 weight% in a curable component, Preferably it is 30 to 60 weight%. (A) By setting the ratio of the component to 10% by weight or more, the cured product has excellent heat resistance and water resistance, and by making it 70% by weight or less, the viscosity of the composition has excellent coating properties. Thus, the cured product has excellent adhesive strength.
In addition, a sclerosing | hardenable component means (A)-(D) component, when a composition does not contain ( F) component, and when it contains ( F) component, (A)-(D) and (F) means a component.

2. Component (B) The component (B) is a compound having a carboxyl group and an ethylenically unsaturated group.
Examples of the ethylenically unsaturated group include a vinyl group, a vinyl ether group, and a (meth) acryloyl group, and a (meth) acryloyl group is preferable.
(B) A component can use only 1 type and can also use 2 or more types together.
The (B) component is used in combination with the later-described (C) component, whereby a remarkable effect of improving the adhesive strength can be obtained. The reason for this is unknown, but it is assumed that a partial esterification reaction with a hydroxyl group contained in the hydrophilic plastic occurs.

Specific examples of the component (B) include, as the compounds each having one carboxyl group and ethylenically unsaturated group in the molecule, acrylic acid and methacrylic acid, and the like. Examples of those having an ethylenically unsaturated group include fumaric acid and maleic acid.
As the component (B), acrylic acid or methacrylic acid is preferable from the viewpoint of copolymerizability with other components, and methacrylic acid is more preferable from the viewpoint of safety in handling.
As the component (B), these compounds may be used alone or in combination of two or more.

(B) containing proportion of component is from 3 to 30 wt% in the curable components is preferably 5 to 30 wt%, more preferably 5 to 20 wt%. (B) By making the ratio of a component 3 weight% or more, it can be excellent in adhesive strength, and by making it 30 weight% or less, the cured product is excellent in moisture and heat resistance and water resistance. be able to.

3. Component (C) The component (C) is a compound having a phosphate group and an ethylenically unsaturated group.
Component (C) is a compound in which one or two hydrogen atoms of orthophosphoric acid are substituted with an ethylenically unsaturated group.
Examples of the ethylenically unsaturated group include a vinyl group, a vinyl ether group, and a (meth) acryloyl group, and a (meth) acryloyl group is preferable.

  A preferred example of the component (C) is a compound in which one or two hydrogen atoms of orthophosphoric acid are substituted with a (meth) acryloyl group, and is excellent in solubility in the composition. A compound represented by the following formula (1) substituted with one organic group (hereinafter referred to as (C-1)), or represented by the following formula (2) in which two hydrogen atoms of orthophosphoric acid are substituted with an organic group. The compound [hereinafter referred to as (C-2)] is preferred.

RO-PO- (OH) ₂ (1)
(RO) ₂ -PO- (OH) (2)

In the formulas (1) and (2), R means a (meth) acryloyloxyalkyl group.
Examples of the (meth) acryloyloxyalkyl group in R include a 2- (meth) acryloyloxyethyl group and a 2- (meth) acryloyloxypropyl group.

As (C-1) and (C-2), a compound in which R is a (meth) acryloyloxyalkyl group is preferable because of its excellent shear adhesive strength and peel adhesive strength.
More preferred is a compound wherein R is a methacryloyloxyalkyl group.
A particularly preferred compound is 2-methacryloyloxyethyl acid phosphate.
As the component (C), these compounds may be used alone or in combination of two or more.

Containing proportion of component (C), from the viewpoint of storage stability of the adhesive strength and composition is 0.1 to 15 wt% in the curable component, is good Mashiku 0.5-7 wt%, More preferably, it is 1 to 5% by weight. (C) By making the content rate of a component 0.1 weight% or more, adhesiveness can be improved significantly, and by making it 15 weight% or less, the ester bond which a sclerosing | hardenable component has is cut | disconnected. This can prevent a decrease in the viscosity of the composition over time.
By combining the component (B) and the component (C) in the composition of the present invention, the adhesion to the hydrophilic plastic substrate is remarkably improved. As described above, it is presumed that the component (C) promotes the esterification reaction between the hydroxyl group of the hydrophilic plastic and the carboxyl group of the component (B).

4). Component (D) The component (D) is a compound having an aliphatic or alicyclic skeleton and an ethylenically unsaturated group.
Examples of the ethylenically unsaturated group include a vinyl group, a vinyl ether group, and a (meth) acryloyl group, and a (meth) acryloyl group is preferable from the viewpoint of excellent copolymerizability with other components and a curing rate.

In the specific example of the component (D), as the aliphatic (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl Mention may be made of alkyl (meth) acrylates such as (meth) acrylate, heptyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.
Examples of the (meth) acrylate having an alicyclic skeleton include isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and dicyclopentenyloxyethyl (meth) acrylate. It is done.
Among these, (meth) acrylate having an alicyclic skeleton is preferable because the heat resistance of the cured product is particularly excellent, and among these, isobornyl (meth) acrylate is preferable because of its excellent adhesive force.
As the component (D), these compounds may be used alone or in combination of two or more.

(D) proportion of component is 5 to 45 wt% in the curable components, good Mashiku is 20 to 40 wt%. By making the ratio of the component (D) 5% by weight or more, the cured product can be excellent in moisture and heat resistance and water resistance, and by making it 45% by weight or less, it has excellent adhesion to hydrophilic plastics. Can be.

5. (E) component (E) component is a radical photopolymerization initiator.
The component (E) is a compound that generates radicals by irradiation with active energy rays and initiates polymerization of a compound having an ethylenically unsaturated group.

Specific examples of the component (E) 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- (methylvinyl) 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-o , 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butan-1-one, 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholine-4- Arophenyl) -butan-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 Benzophenones such as (diethylamino) benzophenone, N, N′-tetramethyl-4,4′-diaminobenzophenone, N, N′-tetraethyl-4,4′-diaminobenzophenone and 4-methoxy-4′-dimethylaminobenzophenone Compound;
Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl- (2,4,6-trimethylbenzoyl) phenylphosphinate and bis (2, Acylphosphine oxide compounds such as 6-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 And thioxanthone compounds such as -hydroxypropyl-N, N, N-trimethylammonium chloride and fluorothioxanthone.

Among these, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, ethyl- (2,4,6-trimethylbenzoyl) phenylphosphinate and bis Even when acylphosphine oxide compounds such as (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide irradiate active energy rays through a film containing an ultraviolet absorber or the like and having low permeability. This is preferable because of good curability.
In addition, when these compounds are used, surface hardening can be achieved even if the absorption wavelength is short, such as 1-hydroxycyclohexyl phenyl ketone, for the purpose of improving the surface curability of the part that is susceptible to curing inhibition by oxygen, such as the film end face. Photoinitiators that improve the properties may be combined.
(E) As a component, these compounds may be used independently or may be used in combination of 2 or more type.

(E) the proportion of component is 0.1 to 20 parts by weight of the curable component 100 parts by weight of the total amount, good Mashiku is 1 to 10 parts by weight. (E) By making the ratio of a component into 0.1 weight part or more, the photocurability of a composition can be made sufficient and it shall be excellent in adhesiveness, and shall be 20 weight part or less. Thus, the internal curability of the adhesive layer can be made excellent, and the adhesiveness can be made excellent.

6). Other components The composition of the present invention comprises the components (A) to (E) as essential components, but various components can be blended depending on the purpose.
In order to further improve heat resistance, water resistance, adhesion, and the like, a compound having an ethylenically unsaturated group other than the components (A) to (D) (hereinafter referred to as “component (F)”), an antioxidant [ Hereinafter, “(G) component”], a silane coupling agent, an ultraviolet absorber and the like can be blended.
The components (F) and (G), which are preferable other components, will be specifically described below.

6-1. (F) Component (F) As a component, (meth) acrylate is preferable.
Specific examples of (meth) acrylates include phenoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, benzyl (meth) acrylate, carbitol (meth) acrylate, N-vinylcaprolactone, (meth) acryloylmorpholine, glycidyl. (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) acrylate having a maleimide group, and 1,4-butanediol mono (meta) ) Mono (meth) acrylate such as acrylate; 1,6-hexanediol di (meth) acrylate, nonanediol diacrylate, polyethylene glycol di (meth) acrylate, ethylene glycol di ( Data) acrylate, tribromophenyl oxyethyl (meth) acrylate; and polyester poly (meth) acrylate of (meth) acrylate oligomer and the like.
In addition to these, trifunctional or higher functional (meth) acrylates can also be used.
Specifically, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tris ( 2- (meth) acryloyloxyethyl) isocyanurate and the like.
As the component (F), these compounds may be used alone or in combination of two or more.

  In addition to these, compounds such as those described in pages 53 to 56 of the document “Latest UV Curing Technology” [Printing Information Association, 1991] are listed.

These (meth) acrylates are available as commercial products, manufactured by Toagosei Co., Ltd., Aronix M-305, M-309, M-310, M-315, M-320, M-350, M-360, M-402, M-404, M-408, M-450 etc. are mentioned.
(F) The preferable mixture ratio of a component is the range of 0-30 mass% in a sclerosing | hardenable component.

6-2. (G) Component (G) The antioxidant of a component is mix | blended in order to improve the light resistance of hardened | cured material, for example, phenolic antioxidant, phosphorus antioxidant, sulfur antioxidant, etc. Is mentioned.
Examples of phenolic antioxidants include hindered phenols such as di-t-butylhydroxytoluene. As what is marketed, Ade-20 Co., Ltd. AO-20, AO-30, AO-40, AO-50, AO-60, AO-70, AO-80 etc. are mentioned. Examples of the phosphorus-based antioxidant include phosphines such as trialkylphosphine and triarylphosphine, and trialkyl phosphites and triaryl phosphites. Examples of commercially available products of these derivatives include Adeka Co., Ltd., ADK STAB PEP-4C, PEP-8, PEP-24G, PEP-36, HP-10, 260, 522A, 329K, 1178, 1500, 135A, 3010. Etc.
Examples of the sulfur-based antioxidant include thioether compounds, and examples of commercially available products include AO-23, AO-412S, and AO-503A manufactured by Adeka Corporation. These may be used alone or in combination of two or more.

(G) As for the usage rate when using a component, 0.01 to 5 weight% is preferable in a composition, More preferably, it is 0.1 to 1 weight%.
When the use ratio is 0.1% by weight or more, the durability of the composition can be improved. On the other hand, when it is 5% by weight or less, insufficient curing and insufficient adhesive strength can be prevented.

6-3. Other components In addition to the above, the composition of the present invention may contain other components usually used in adhesive compositions.
Silane coupling agents are silane coupling agents that can improve the interfacial bond strength between the adhesive layer and the hydrophilic plastic, antioxidants and UV absorbers that can enhance the durability of cured products such as heat resistance and weather resistance. It is. The silane coupling agent used in the present invention is not particularly limited as long as it can contribute to improvement in adhesion to the substrate.

  Specifically, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane 3- (meth) acryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- (meth) acryloxypropylmethyldiethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, N-2 -(Aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltriethoxysilane, 3- Aminopropyltrimethoxysilane, 3-aminop Pyrtriethoxysilane, 3-triethoxysilyl-N- (1,3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltri And methoxysilane.

The use ratio when using the silane coupling agent is preferably 0.1 to 10% by weight, more preferably 1 to 5% by weight in the composition.
When the usage ratio is 0.1% by weight or more, the adhesive strength of the composition can be improved. On the other hand, when the usage rate is 10% by weight or less, it is possible to prevent the adhesive force from changing over time. A silane coupling agent may use the above-mentioned compound, or may use 2 or more types.

For the purpose of improving light resistance, an ultraviolet absorber may be used. Triazine-based ultraviolet absorbers such as Tinuvin 400, Tinuvin 405, Tinuvin 460, Tinuvin 479 manufactured by BASF Corporation, Tinuvin 900, Tinuvin 928, Tinuvin 1130 Benzotriazole-based UV absorbers such as
These may be used alone or in combination of two or more. The use ratio when using the ultraviolet absorber is preferably 0.01 to 5% by weight, more preferably 0.1 to 1% by weight in the composition. If it exceeds 5 parts by weight, the curability of the composition is significantly reduced.

  As other components other than the above, specifically, inorganic fillers, softeners, antioxidants, anti-aging agents, stabilizers, tackifying resins, leveling agents, antifoaming agents, plasticizers, dyes, pigments, A treating agent, an ultraviolet blocking agent, and the like can be blended.

7). As a method for producing an active energy ray-curable adhesive composition for plastic films or sheets , the above components (A) to (E) are further agitated and mixed in accordance with conventional methods, if necessary, and other components. Can be manufactured.
In this case, heating can be performed as necessary. The heating temperature may be appropriately set according to the composition to be used, the substrate, the purpose, etc., but is preferably 30 to 80 ° C.

The composition of the present invention can be used for adhesion between plastic films and the like, and adhesion between plastic films and the like and various other substrates (hereinafter referred to as other substrates).
In the following, when simply described as “base material”, it means a general term for plastic films and other base materials.
Other examples of the substrate include paper and metal.
As a method of use, a conventional method may be used, and examples include a method of applying to a base material, pasting with another base material, and irradiating active energy rays.

Examples of the material in the plastic film include polyvinyl chloride resin, polyvinylidene chloride, cellulosic resin, polyethylene, polypropylene, polystyrene, ABS resin, polyamide, polyester, polycarbonate, polyurethane, polyvinyl alcohol, triacetyl cellulose, cycloolefin polymer, Examples include polymethyl methacrylate, acrylic / styrene resin, ethylene-vinyl acetate copolymer, and chlorinated polypropylene.
Examples of the paper include imitation paper, fine paper, craft paper, art coated paper, caster coated paper, pure white roll paper, parchment paper, water resistant paper, glassine paper, and corrugated paper.
Examples of the metal foil include aluminum foil.

Coating on the substrate may be performed by a conventionally known method, natural coater, knife belt coater, floating knife, knife over roll, knife on blanket, spray, dip, kiss roll, squeeze roll, reverse roll, air blade , Curtain flow coater, comma coater, gravure coater, micro gravure coater, die coater and curtain coater.
Moreover, what is necessary is just to select the application | coating thickness of the composition of this invention according to the base material to be used and a use, However, Preferably it is 0.1-100 micrometers, More preferably, it is 1-25 micrometers.

Examples of the active energy rays include visible light, ultraviolet rays, X-rays, and electron beams, but ultraviolet rays are preferable because inexpensive devices can be used.
Various light sources can be used as the light source when cured by ultraviolet rays, and examples thereof include a pressurized or high pressure mercury lamp, a metal halide lamp, a xenon lamp, an electrodeless discharge lamp, a carbon arc lamp, and an LED.
In the case of curing with an electron beam, various devices can be used as an EB irradiation device that can be used, such as a Cockloft-Waltsin type, a bandegraph type, and a resonance transformer type device. What has the energy of 1000 eV is preferable, More preferably, it is 100-300 eV.

The composition of the present invention is suitable for bonding a thin layer adherend as a substrate.
The method of use for adhering the thin-layer adherend may be in accordance with a method usually used in the production of laminates.
For example, a method in which the composition is applied to a first thin-layer adherend, dried as necessary, and then a second thin-layer adherend is bonded thereto and irradiated with active energy rays. Is mentioned.

Examples of the thin layer adherend include plastic film, paper, metal foil, and the like.
The plastic film or the like needs to be capable of transmitting active energy rays, and the film thickness may be selected according to the thin layer adherend to be used and the application, but preferably the thickness is 0.5 mm or less. is there.

Among these thin layer adherends, the composition of the present invention is suitably used for bonding plastic films and the like, and can be suitably used for hydrophilic plastics.
Specific examples of hydrophilic plastics include plastics produced by molding and processing polymers containing hydrophilic sites such as hydroxyl groups, carboxyl groups, phosphate groups, sulfonate groups, amino groups and amide bonds. Can do. Preferable examples of the polymer containing a hydrophilic part include polyvinyl alcohol, triacetyl cellulose, polyvinyl acetal, polyamide and the like. As the polyvinyl alcohol, those partially partially butyralized can also be used.
In addition, it is also possible to use a polymer which has been subjected to hydrophilic treatment after molding a polymer having no hydrophilic portion. Specifically, a plastic or the like in which a hydrophilic group is introduced into a polymer having no hydrophilic portion by corona treatment, plasma treatment, flame treatment, primer treatment of a hydrophilic portion-containing polymer, or the like can be given. Preferable specific examples include polyethylene terephthalate primer-treated with polyamide.
As the hydrophilic plastic, a plastic produced by molding a polymer containing a hydrophilic part is preferable, and polyvinyl alcohol and triacetyl cellulose are more preferably used as the polymer containing a hydrophilic part.

  Further, before bonding the adherend, an activation treatment can be performed on one or both surfaces in order to increase the interlayer adhesion. Examples of the surface activation treatment include plasma treatment, corona discharge treatment, chemical treatment, surface roughening treatment and etching treatment, and flame treatment, and these may be used in combination.

Coating on the thin layer adherend may be performed according to a conventionally known method, and examples thereof include the same method as described above.
The coating thickness of the composition of the present invention may be selected according to the thin layer adherend to be used and the application, but the same coating thickness as described above is preferable.

Laminate films obtained from the composition of the present invention are excellent in adhesive strength under high temperature and high humidity conditions, and therefore suitable for optical films such as polarizing plates and protective films, retardation films used in liquid crystal display devices and the like. Can be used for
Especially the composition of this invention can be preferably used for manufacture of a polarizing plate and a polarizing plate with retardation film. Hereinafter, the manufacturing method of a polarizing plate is demonstrated.

  In the present specification, a polarizer means a film or film having a polarizing function described later, and a polarizing plate is a polarizer with a protective layer in which one or both sides of the polarizer are protected by a film or film. Represents that. Moreover, a polarizing plate with a retardation film represents a polarizer or a polarizing plate in which a retardation film is bonded or a film having a retardation function is formed by coating.

7-1. Production method of polarizing plate As described above, the composition of the present invention can be preferably used for adhesion of hydrophilic plastics. In the production of a polarizing plate, polyvinyl alcohol used as a polarizer and tri-layer used as a protective film for a polarizer. Acetyl cellulose corresponds to a hydrophilic plastic.

  The composition of the present invention can be used for adhesion between a polarizer and a protective film and adhesion between a polarizing plate and a retardation film.

A polarizer has a function of selectively transmitting linearly polarized light in one direction from natural light.
Specific examples of polarizers include iodine polarizers in which iodine is adsorbed and oriented on a polyvinyl alcohol film, dichroic dyes in which dichroic dye is adsorbed and oriented on a polyvinyl alcohol film, and (lyotropic) liquid crystal Examples thereof include a coating type polarizer coated with a dye in a state, oriented and fixed.
These iodine-based polarizers, dye-based polarizers, and coating-type polarizers have the function of selectively transmitting one direction of linearly polarized light from natural light and absorbing the other direction of linearly polarized light. It is called a type polarizer.

  In the iodine-based polarizer and the dye-based polarizer, a protective layer is usually provided on one side or both sides thereof, but the composition of the present invention can be used for bonding the polarizer and the protective film.

  Examples of protective films used in the protective layer include cellulose acetate resin films such as triacetyl cellulose and diacetyl cellulose, acrylic resin films, polyester resin films, polyarylate resin films, polyether sulfone resin films, and cyclic rings such as norbornene. Examples thereof include cyclic polyolefin resin films containing olefin as a monomer.

Next, the composition of this invention can also be used for adhesion | attachment of a polarizing plate and retardation film.
In this case, a polarizing plate having a protective layer on one side or both sides can be used.
In this case, the protective layer may be one obtained by bonding the protective film or a protective film formed by coating.
In a polarizing plate provided with a protective layer only on one side, the surface to be bonded to the retardation film may be a surface with a protective layer or a surface without a protective layer.

  Various types of retardation films can be used. Optical films that have been subjected to processing such as uniaxial or biaxial stretching, or liquid crystal compounds are applied to a substrate, and processed to be oriented and fixed. An optical film or the like is used, and the magnitude relationship (refractive index ellipsoid) of the three-dimensional refractive index is controlled in accordance with the use conditions. It is mainly used to compensate for coloration of the liquid crystal layer of a liquid crystal display and to compensate for changes in phase difference due to viewing angle.

Specific examples of retardation films include optical film materials that are subjected to processing such as stretching, polyolefins such as polyethylene, polypropylene, and cyclic polyolefins, polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polyarylate. And polyamide.
The above-mentioned cyclic polyolefin is a general generic name for resins obtained from cyclic olefins such as norbornene, tetracyclododecene, and derivatives thereof. For example, JP-A-3-14882 and JP-A-3-122137. Etc. are mentioned.
Specifically, ring-opening polymers of cyclic olefins, addition polymers of cyclic olefins, random copolymers of cyclic olefins and α-olefins such as ethylene and propylene, and these are modified with unsaturated carboxylic acids or their derivatives. Examples of such graft-modified products can be given. Furthermore, these hydrides are mentioned. Examples of the products include ZEONEX and ZEONOR manufactured by Nippon Zeon Co., Ltd., Arton manufactured by JSR Corporation, and TOPAS manufactured by TICONA.

  In addition, as an optical film that is coated with a liquid crystal compound or the like and processed for orientation and fixation, “WV film” [Fuji Photo Film Co., Ltd.], “LC film”, “NH film” (Both made by Nippon Oil Corporation).

The manufacturing method of a polarizing plate or a polarizing plate with a retardation film will be described using the composition of the present invention.
Examples of the production method include a method including the following steps [1] to [3].
[1] A step of applying the composition of the present invention to any one of a polarizer, a polarizing plate, a protective film, a protective film, a retardation film, and a retardation film as an adherend.
[2] A step of laminating one of a polarizer, a polarizing plate, a protective film, a protective film, a retardation film, and a retardation film as the other adherend to the film coated with the composition
[3] A step of irradiating active energy rays through a substrate coated with the composition of the present invention after laminating the films. When laminating a protective film or a retardation film only on one side, polarization is performed according to the above procedure. A plate or a polarizing plate with a retardation film can be produced, but when pasting on both sides, the step [3] may be carried out after repeating the steps [1] and [2] twice. [1], [2] and [3] may be repeated twice.

  The coating method in the step [1] and the active energy ray irradiation method in the step [3] may be performed by the same method as described above.

When using a polarizing plate with a retardation film as a circularly polarizing plate, in order to obtain a circularly polarized state over a wide band, a retardation film having a different retardation is further pasted on the retardation film side of the polarizing plate with a retardation film. It can also be combined.
Specifically, there is a method in which a retardation film having a ½ wavelength with respect to each wavelength is bonded to a polarizing film, and a retardation film having a ¼ wavelength is bonded to each wavelength. . In this case, step [3] may be performed after steps [1] and [2] are repeated three times, or steps [1], [2] and [3] may be repeated three times.

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

○ Examples 1 to 8 and Comparative Examples 1 to 8
The components (A) to (G) shown in Table 1 below were dissolved by heating and stirring at 60 ° C. for 1 hour to produce an active energy ray-curable adhesive composition.

The obtained composition was evaluated according to the following test method. The results are shown in Table 2.
(25 ° C viscosity)
The viscosity of the active energy ray-curable adhesive composition at 25 ° C. was measured using an E-type viscometer. Further, the viscosity after one week from the blending was measured, and the change with time was confirmed.

The numbers in Table 1 mean the number of copies. Abbreviations in Table 1 are as follows.
1) Component (A) KY-303: Polyether urethane acrylate, Mw: 15,000, manufactured by Negami Kogyo Co., Ltd., trade name Art Resin KY-303
M-1600: polyether urethane acrylate, Mw: 3,000, manufactured by Toagosei Co., Ltd., trade name Aronix M-1600
OT-1001: Polyester urethane acrylate, Mw: 40,000, manufactured by Toagosei Co., Ltd., trade name Aronix OT-1001

2) Component (B) MAA: methacrylic acid, GE-110 manufactured by Mitsubishi Gas Chemical Company, Inc.

3) Component (C) P-2M: 2-methacryloyloxyethyl acid phosphate, manufactured by Kyoeisha Chemical Co., Ltd. Light ester P-2M

4) Component (D) -IBXA: Isobornyl acrylate, manufactured by Kyoeisha Chemical Co., Ltd. Light acrylate IB-XA
FA-513AS: dicyclopentanyl acrylate, manufactured by Hitachi Chemical Co., Ltd. FA-513AS

5) Component (E) Irg819: Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, IRGACURE819 manufactured by BASF
TPO: 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, BASF DAROCUR TPO
Irg184: 1-hydroxy-cyclohexyl-phenyl-ketone, IRSFACURE184 manufactured by BASF
6) Component (F) HPA: 2-hydroxypropyl acrylate, Kyoeisha Chemical Co., Ltd. light ester HOP-A
# 190: 2- (Ethoxyethoxy) ethyl acrylate, Osaka Organic Chemical Industry Co., Ltd. Viscoat 190
-HBA: 2-hydroxybutyl acrylate, Kyoeisha Chemical Co., Ltd. light acrylate HOB-A
POA: Phenoxyethyl acrylate, Kyoeisha Chemical Co., Ltd. light acrylate PO-A
THFA: Tetrahydrofurfuryl acrylate, Kyoeisha Chemical Co., Ltd. light acrylate THF-A

6) Component (G) AO-80: 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane, Adeka Corporation Adeka Stub AO-80
3010: triisodecyl phosphite, Adeka Co., Ltd. Adeka Stub 3010

(Model experiment for manufacturing polarizing plate)
Assuming that a polarizer and a protective layer, which are hydrophilic plastics, are bonded for manufacturing a polarizing plate, the following model experiment was conducted using a PET film U34 (50 μm) manufactured by Toray Industries, Inc. as a base material for an adhesion test. went.
The composition obtained above was applied on a film to a thickness of 25 μm by a bar coater. After laminating U34, a 160 W / cm condensing type metal halide lamp (30 cm from the focal length) was used to cure at a conveyor speed of 5 m / min to produce a laminate film as a test specimen. The ultraviolet intensity was 150 mW / cm ² and the integrated light quantity was 400 mJ / cm ² (both values at 365 nm).

The obtained specimen was allowed to stand at room temperature for 30 minutes or more, and then the peel strength was measured with a tensile tester (Instron 5564 manufactured by Instron Japan Company Limited) under the following conditions.
-Test piece: 25 mm x 100 mm
Test method: T-shaped peeling / peeling speed: 200 mm / min
Next, the obtained specimen was subjected to a high temperature test and a high humidity test under the following conditions, and then peel strength was measured by the same method and conditions as described above.
After high temperature test: 96 hours at 85 ° C. After high humidity test: 96 hours at 60 ° C. and 90% RH.

The composition of the present invention was excellent in initial adhesive strength and excellent in adhesive strength after a high temperature test and a high humidity test.
In the compositions of Comparative Examples 1 to 4, both the initial adhesive strength and the adhesive strength after the high humidity test were low.

  The composition of the present invention can be used as an adhesive for various plastic films, especially as an adhesive for hydrophilic plastics, and is particularly suitable for the production of optical films such as liquid crystal display devices, particularly for the production of polarizing plates. Can be used for

Claims (10)

Active energy for plastic film or sheet comprising the following components (A) to (E) as essential components, optionally including the following components (F), and including the following components (A) to (F) in the following proportions: A wire curable adhesive composition.
(A) Urethane (meth) acrylate: 10 to 70% by weight in the curable component
(B) Compound having carboxyl group and ethylenically unsaturated group: 3 to 30% by weight in the curable component
(C) Compound having phosphoric acid group and ethylenically unsaturated group: 0.1 to 15% by weight in curable component
(D) Compound having aliphatic group or alicyclic skeleton and ethylenically unsaturated group: 5 to 45% by weight in the curable component
(E) Photoradical polymerization initiator: 0.1 to 20 parts by weight relative to 100 parts by weight of the total amount of curable components
(F) Compounds having an ethylenically unsaturated group other than the components (A) to (D): 0 to 30% by weight in the curable component
In addition, a sclerosing | hardenable component means (A)-(D) component, when a composition does not contain ( F) component, and when it contains ( F) component, (A)-(D) and (F) means a component. The active energy ray-curable adhesive composition for plastic film or sheet according to claim 1, wherein the component (B) is contained in the curable component in an amount of 5 to 30% by weight. The component (A) is a compound having two (meth) acryloyl groups, a polyether skeleton, and a weight average molecular weight of 3,000 to 40,000. The active energy ray-curable adhesive composition for plastic film or sheet as described. The active energy ray curing for plastic films or sheets according to any one of claims 1 to 3, wherein the component (B) comprises a compound having one ethylenically unsaturated group and one carboxyl group. Mold adhesive composition. (B) A component is (meth) acrylic acid, The active energy ray hardening-type adhesive composition for plastic films or sheets of any one of Claims 1-4. (C) A component is 2-methacryloyloxyethyl acid phosphate, The active energy ray hardening-type adhesive composition for plastic films or sheets of any one of Claims 1-5. The component (D) is a compound having an alicyclic skeleton and an ethylenically unsaturated group. The active energy ray-curable adhesive composition for plastic film or sheet according to any one of claims 1 to 6. object. A hydrophilic plastic obtained by producing a polymer in which either one or both of a plastic film or sheet contains a hydrophilic part selected from a hydroxyl group, a carboxyl group, a phosphoric acid group, a sulfonic acid group, an amino group and an amide bond. The active energy ray-curable adhesive composition for plastic film or sheet according to any one of claims 1 to 7 . The plastic film or sheet is a polyvinyl alcohol resin, The active energy ray-curable adhesive composition for a plastic film or sheet according to any one of claims 1 to 8 . Claim 1 polarizing plate prepared for radiation-curable adhesive composition comprising a composition according to any one of claims 9.