TWI675081B - Optical film with adhesive agent and optical laminate - Google Patents

Abstract

This case provides an optical film with an adhesive provided with an adhesive layer directly on one side of a polarizing film, and an optical laminate having excellent durability to which the film is applied.

The optical film with an adhesive according to the present invention is an optical film with an adhesive having an adhesive layer formed on one side of a polarizing film. The adhesive layer is composed of acrylic resin, epoxy resin-free or The adhesive composition of the primary amine-based silane compound is formed, and the sum of the thickness of the polarizing film and the thickness of the adhesive layer is 55 μm or less.

Description

Optical film and optical laminate with adhesive

The present invention relates to an optical film with an adhesive and an optical laminate in which an adhesive layer is directly formed on one side of a polarizing film.

Liquid crystal display devices have been used in desktop computers and electronic clocks in the past, but in recent years, their use has continued to develop rapidly, from mobile devices such as mobile phones to large televisions, regardless of screen size. In addition to liquid crystal display devices, organic electroluminescence (organic EL) display devices tend to increase in mobile applications. In addition, the polarizing plates used in these image display devices have not only increased demand, but also required performance suitable for various applications.

The above-mentioned polarizing plate is generally formed by laminating a protective film on both sides of a polarizing film including a polyvinyl alcohol-based resin having a dichroic dye adsorbed and oriented. In addition, in order to adhere to a liquid crystal cell or other optical members, an adhesive layer is provided on one side of the polarizing plate, and a release film is attached to the surface of the adhesive layer to circulate. Before the laminated body having such a structure is bonded to the liquid crystal cell, the release film is peeled from the polarizing plates provided with the adhesive layer, and the laminated body is bonded to the liquid crystal cell through the exposed adhesive layer. This setting has adhesion The polarizing plate of the agent layer generates static electricity when the release film is peeled off and bonded to the liquid crystal cell. Therefore, it is strongly desired to develop a countermeasure against this situation.

Therefore, it is proposed that an ionic compound is formulated in the adhesive composition, and thereby the adhesive layer formed thereon imparts antistatic properties. For example, in Japanese Patent No. 5323315 (Patent Document 1), it is disclosed that an ionic compound having an organic cation and solid at room temperature (25 ° C) is blended in an acrylic adhesive. Furthermore, Japanese Patent No. 5457761 (Patent Document 2) has disclosed that an ionic compound composed of an alkali metal cation and a bis (fluorosulfofluorenyl) fluorenimide anion is blended in an acrylic adhesive.

On the other hand, with the recent diversification of liquid crystal display devices, thinner and lighter components are required. Therefore, a polarizing plate provided with a protective film on only one side of the polarizing film is used, and an adhesive layer is directly provided on the other side of the polarizing film to be laminated on the liquid crystal cell or the like. In this configuration, when the above-mentioned antistatic adhesive is used as the adhesive, for example, in a hot and humid environment, there is a problem that deterioration of the polarizing film (deiodination) occurs.

In order to solve this problem, Japanese Patent Application Laid-Open No. 2012-247574 (Patent Document 3) has disclosed that an alkali metal salt is blended in an acrylic adhesive. However, the method described in Patent Document 3 has room for improvement in optical durability.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 5332315 (Japanese Patent Laid-Open No. 2009-79205)

[Patent Document 2] Japanese Patent No. 5457761 (Japanese Patent Application No. 2011-517722)

[Patent Document 3] Japanese Patent Laid-Open No. 2012-247574

The present invention was developed by a developer in order to solve the above-mentioned problems, and is to provide an optical film with an adhesive provided with an adhesive layer directly on one side of a polarizing film, and an optical laminate having excellent optical durability to which the film is applied.

That is, the present invention is an optical film with an adhesive layer formed with an adhesive layer on one side of a polarizing film, and the adhesive layer is composed of an acrylic resin and a silane containing no epoxy group or primary amine group. The compound adhesive composition is formed, and the sum of the thickness of the polarizing film and the thickness of the adhesive layer is 55 μm or less.

The adhesive composition may further include an antistatic agent having an inorganic cation. The inorganic cation is preferably an alkali metal or alkaline earth metal cation, and more preferably an alkali metal cation.

In the above-mentioned optical film with an adhesive, the thickness of the polarizing film is preferably 30 μm or less, and the thickness of the adhesive layer is more preferably 45 μm or less.

A protective film is also laminated on the side opposite to the adhesive layer of the optical film with an adhesive. In any of the above-mentioned optical films with an adhesive, a release film is preferably laminated on the adhesive.

For any of the above optical films with an adhesive, after peeling the release film from the adhesive layer, the optical film can be attached to the liquid crystal cell on the side of the adhesive layer. The optical film with an adhesive is a laminated body obtained by laminating an adhesive to an alkali-free glass through the adhesive, and the change in polarization degree after storage at a temperature of 80 ° C and a relative humidity of 90% for 24 hours is -1 A range of 0 percent is more preferable. In addition, the optical film with an adhesive is a laminated body obtained by laminating an adhesive-free glass to an alkali-free glass through the adhesive, and storing the monomer transmittance change after storage at a temperature of 80 ° C and a relative humidity of 90% for 24 hours. It is better to be less than 2%.

In another aspect, the present invention is an optical laminate, which is obtained by peeling a release film from an adhesive layer of any of the above-mentioned optical films with an adhesive, and bonding the liquid crystal cell to the adhesive layer side.

According to the present invention, an adhesive-attached optical film with an adhesive layer formed directly on one side of the polarizing film can suppress the deterioration of the polarizing film in a hot and humid environment. Moreover, by applying this optical film with an adhesive to a glass substrate, it can be set as the optical laminated body for liquid crystal display devices. This optical laminate system is excellent in thinness, lightness, and durability.

The optical film with an adhesive according to the present invention has a constitution in which an adhesive layer is directly provided on one side of the polarizing film as described above. Hereinafter, each member constituting the optical film with an adhesive will be described.

[Polarizing film]

The polarizing film is a film having a function of extracting linearly polarized light from incident natural light. For example, it can be used for a polyvinyl alcohol-based resin film to adsorb and orient a polarizing film having a dichroic dye. The polyvinyl alcohol-based resin constituting the polarizing film can be obtained by saponifying a polyvinyl acetate-based resin. The polyvinyl acetate-based resin is other than polyvinyl acetate which is a homopolymer of vinyl acetate, and examples thereof include copolymers of vinyl acetate and other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamide having an ammonium group.

The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be further modified. For example, polyvinyl aldehyde and polyvinyl acetal modified with aldehydes may be used. The polymerization degree of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

Those who make such a polyvinyl alcohol-based resin use an embryonic film as a polarizing film. The polyvinyl alcohol-based resin can be formed into a film by a known method. The film thickness of the embryonic membrane made of a polyvinyl alcohol-based resin is not particularly limited, and is, for example, about 1 to 150 μm. When the ease of extension is taken into consideration, the film thickness is preferably 10 μm or more.

The polarizing film is applied to the embryonic film of such a polyvinyl alcohol-based resin: a step of uniaxial extension, a step of dyeing the film with a dichroic pigment and adsorbing the dichroic pigment, a step of treating the film with an aqueous boric acid solution, and The step of washing the film with water is finally manufactured by drying. As the dichroic dye system, iodine or a dichroic organic dye can be used. In terms of the film thickness of the polarizing film, usually 1 to 30 μm is used.

[Adhesive]

The adhesive layer of the present invention is formed of an adhesive composition mainly comprising an acrylic resin and further containing a silane compound.

(Acrylic)

The acrylic resin used in the adhesive composition may be a polymer containing a structural unit derived from a (meth) acrylic acid ester represented by the following formula (I) as a main component. Generally, it further includes other structural units. , Especially the structural unit derived from a monomer having a polar functional group. In the present specification, "(meth) acrylic acid" means either acrylic acid or methacrylic acid, and the same applies to "(meth)" when it is referred to as (meth) acrylate or the like.

In the above formula (I), which becomes a main structural unit of an acrylic resin, R ¹ is a hydrogen atom or a methyl group, and R ² is an alkyl group or an aralkyl group having 1 to 14 carbon atoms, and an alkyl group is preferred. The alkyl or aralkyl group represented by R ² may be substituted with a hydrogen atom in each group by an alkoxy group having 1 to 10 carbon atoms.

The (meth) acrylate represented by formula (I), specifically, may be Examples: Linear alkyl acrylates such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, and lauryl acrylate; such as isobutyl propylene, 2-ethylhexyl acrylate, Branched alkyl acrylates of isooctyl acrylate; such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, lauryl methacrylate Linear alkyl methacrylate; such as isobutyl methacrylate, 2-ethylhexyl methacrylate, branched alkyl methacrylate, etc.

When R ² is an alkoxy-substituted alkyl group, that is, when R ² is an alkoxy alkyl group, as the (meth) acrylate represented by the formula (I), specifically, acrylic acid 2 may be exemplified. -Methoxyethyl, ethoxymethyl acrylate, 2-methoxyethyl methacrylate, ethoxymethyl methacrylate, and the like. When R ² is an aralkyl group, specific examples of the (meth) acrylate represented by formula (I) include benzyl acrylate and benzyl methacrylate.

These (meth) acrylic acid esters can be used individually as a raw material, and a different plural number can also be used. Among these, n-butyl acrylate is preferably used. Specifically, among all the monomers constituting the acrylic resin, it is preferable that the n-butyl acrylate is 50% by weight or more. Of course, in addition to n-butyl acrylate, other (meth) acrylates corresponding to formula (I) may be used in combination.

When the acrylic resin contains a structural unit derived from a monomer having a polar functional group, it is preferable that the monofunctional system having a polar functional group is a (meth) acrylic compound having a polar functional group. Examples of the polar functional group possessed by the monomer include free carboxyl, hydroxyl, amine, and epoxy groups. The first heterocyclic group.

Examples of monomers having polar functional groups include: monomers having free carboxyl groups such as acrylic acid, methacrylic acid, and β-carboxyethyl (meth) acrylate; such as 2-hydroxy (meth) acrylate Ethyl ester, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2- (2-hydroxyethoxy) ethyl (meth) acrylate, 2- (meth) acrylate 2- Or 3-chloro-2-hydroxypropyl ester, diethylene glycol mono (meth) acrylate monomer having a hydroxyl group; such as propylene morpholine, vinyl caprolactam, N-vinyl-2- Pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth) acrylate, caprolactone modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexyl methyl (meth) acrylate, (methyl ) Glycidyl acrylate, 2,5-dihydrofuran monomers with heterocyclic groups; such as amino (meth) acrylate, N, N-dimethylamino ethyl (meth) acrylate, Monomer of dimethylaminopropyl (meth) acrylate, which has an amine group different from a heterocyclic ring, etc. These polar functional groups may be used individually, or different plural kinds may be used.

Among these, in consideration of the reactivity of the obtained acrylic resin, it is preferable to use a monomer having a hydroxyl group as the polar functional group-containing monomer constituting the acrylic resin. Moreover, in addition to the monomer having a hydroxyl group, it is also effective to use another monomer having a polar functional group, such as a monomer having a free carboxyl group.

The acrylic resin may further include a structural unit derived from a monomer other than the formula (I) having an aromatic ring. The monomer having an aromatic ring other than the formula (I) is preferably a compound having one olefinic double bond and at least one aromatic ring in the molecule without a polar functional group. Suitable examples include Examples include (meth) acrylic compounds having an aromatic ring. The (meth) acrylic compound having such an aromatic ring also includes benzyl acrylate, neopentyl glycol benzoate (meth) acrylate, and the like, but particularly preferably contains benzene represented by formula (II) (Meth) acrylate of oxyethyl.

In the formula, R ³ represents a hydrogen atom or a methyl group, n represents an integer of 1 to 8, and R ⁴ represents a hydrogen atom, an alkyl group, an aralkyl group, or an aryl group. When R ⁴ is an alkyl group, its carbon number may be about 1 to 9, similarly, when it is an aralkyl group, its carbon number may be about 7 to 11 and, when it is an aryl group, its carbon number may be 6 to Around 10.

Examples of the alkyl group having 1 to 9 carbon atoms constituting R ⁴ in formula (II) include methyl, butyl, and nonyl; examples of the aralkyl group having 7 to 11 carbon atoms include benzyl, phenethyl, and naphthyl Examples of the aryl group having 6 to 10 carbon atoms include phenyl, tolyl, and naphthyl.

To give specific examples of phenoxyethyl-containing (meth) acrylates represented by formula (II), there are: 2-phenoxyethyl (meth) acrylate, (meth) acrylate 2 -(2-phenoxyethoxy) ethyl ester, (meth) acrylate of nonylphenol modified by ethylene oxide, 2- (o-phenylphenoxy) ethyl (meth) acrylate, etc. . These (meth) acrylic acid esters containing a phenoxyethyl group may be used individually, respectively, and you may use them in combination of multiple plural. Among these, 2-phenoxyethyl (meth) acrylate or 2- (2-benzene) Ethoxyethoxy) ethyl ester is one of unsaturated monomers having an aromatic ring constituting an acrylic resin.

The acrylic resin contained as the main component in the adhesive composition is based on the total solid content, and the structural unit derived from the (meth) acrylate represented by the aforementioned formula (I) is usually 60 to 99.9% by weight. It is preferably contained in a proportion of 80 to 99.6% by weight. The structural unit derived from a monomer having a polar functional group is usually contained in a proportion of 0.1 to 20% by weight, preferably 0.4 to 10% by weight. It is contained in a proportion, and a structural unit derived from a monomer other than formula (I) having an aromatic ring is usually contained in a proportion of 0 to 40% by weight, and preferably contained in a proportion of 6 to 12% by weight.

The acrylic resin used in the present invention may be other than the (meth) acrylate of the formula (I), the monomer having a polar functional group, and the monomer other than the formula (I) having an aromatic ring, as described above. Contains building blocks derived from monomers other than these. Examples include: a structural unit derived from a (meth) acrylate having an alicyclic structure in the molecule, a structural unit derived from a styrene monomer, a structural unit derived from a vinyl monomer, A structural unit having a plurality of (meth) acrylfluorenyl monomers in the molecule, a structural unit derived from a (meth) acrylfluorene derivative, and the like.

The carbon number of the alicyclic structure is usually a cycloparaffin structure of 5 or more, preferably about 5 to 7. Specific examples of the acrylate having an alicyclic structure include isoamyl acrylate, cyclohexyl acrylate, dicyclopentyl acrylate, cyclododecyl acrylate, methyl cyclohexyl acrylate, and trimethyl cyclohexyl acrylate. , Tert-butyl cyclohexyl acrylate, α-ethoxy cyclohexyl acrylate, cyclohexyl phenyl acrylate, etc .; have alicyclic Specific examples of the structured methacrylate include isopropyl methacrylate, cyclohexyl methacrylate, dicyclopentyl methacrylate, cyclododecyl methacrylate, and methyl cyclohexyl methacrylate. , Trimethylcyclohexyl methacrylate, third butyl cyclohexyl methacrylate, cyclohexyl phenyl methacrylate, and the like.

Examples of the styrene-based monosystem include methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, and propylene. Alkylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene; such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene Halogenated styrene; and, nitrostyrene, acetonitrile, methoxystyrene, divinylbenzene, and the like.

Examples of vinyl-based monomers include fatty acid vinyl esters of vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; vinyl halogenated vinyl chloride and vinyl bromide; Such as vinylidene chloride halogenated vinylidene; such as vinylpyridine, vinylpyrrolidone, vinylcarbazole nitrogen-containing aromatic ethylene; such as butadiene, isoprene, chlorodipine conjugated diene monomer; and , Acrylonitrile, methacrylonitrile, etc.

Examples of the monomer having a plurality of (meth) acrylfluorenyl groups in the molecule include 1,4-butanediol di (meth) acrylate and 1,6-hexanediol di (meth) acrylate , 1,9-nonanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate Tripropylene glycol di (meth) acrylate monomers with two (meth) acrylfluorene groups in the molecule; such as trimethylolpropane tris (methyl (Meth) acrylate is a monomer having three (meth) acrylfluorene groups in the molecule.

Examples of (meth) acrylamide derivatives include N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, and N- (3-hydroxypropyl) ) (Meth) acrylamide, N- (4-hydroxybutyl) (meth) acrylamide, N- (5-hydroxypentyl) (meth) acrylamide, N- (6-hydroxyhexyl) ) (Meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamine Amine, N- (3-dimethylaminopropyl) (meth) acrylamide, N- (1,1-dimethyl-3-oxobutyl) (meth) acrylamide, N -[2- (2-Pendoxy-1-imidazolidinyl) ethyl] (meth) acrylamide, 2-propenylamino-2-methyl-1-propanesulfonic acid, N- (formaldehyde Oxymethyl) acrylamide, N- (ethoxymethyl) (meth) acrylamide, N- (propoxymethyl) (meth) acrylamide, N- (1-methyl Ethoxymethyl) (meth) acrylamide, N- (1-methylpropoxymethyl) (meth) acrylamide, N- (2-methylpropoxymethyl) (methyl Acryl) acrylamide [alias N- (isobutoxymethyl) (meth) acrylamide], N- (butoxymethyl) (meth) acrylamide, N- (1,1- (Dimethyl ethoxymethyl) (methyl Propyl) acrylamide, N- (2-methoxyethyl) (meth) acrylamide, N- (2-ethoxyethyl) (meth) acrylamide, N- (2-propyl (Oxyethyl) (meth) acrylamide, N- [2- (1-methylethoxy) ethyl] (meth) acrylamide, N- [2- (1-methylpropoxyl) (Yl) ethyl] (meth) acrylamide, N- [2- (2-methylpropoxy) ethyl] (meth) acrylamide [alias N- (2-isobutoxyethyl ) (Meth) acrylamide], N- (2-butoxyethyl) (meth) acrylamide, N- [2- (1,1-dimethylethoxy) ethyl] ( (Meth) acrylamide and the like. Among these, N- (methoxymethyl) acrylamide is particularly preferred, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, or N- (2-methylpropoxy) Methacrylamide.

These monomers can be used individually or in combination of 2 or more types. The acrylic resin used in the adhesive is not derived from (meth) acrylates of the formula (I), monomers other than the formula (I) having an aromatic ring, and monomers having a polar functional group The structural unit of the monomer is based on the total solid content of the resin, and is usually contained in a proportion of 0 to 20% by weight, preferably in a proportion of 0 to 10% by weight.

As described above, the resin component of the adhesive composition can be derived from a (meth) acrylate structural unit represented by the formula (I) as a main component, and includes a structure derived from a monomer having a polar functional group. The unit further includes two or more types of acrylic resins including an arbitrary structural unit derived from a monomer other than the formula (I) having an aromatic ring. Furthermore, the acrylic resin and the acrylic resin different from the acrylic resin may be, for example, an acrylic resin having a structural unit derived from a (meth) acrylate of the formula (I) and having no polar functional group. The structural unit derived from the (meth) acrylic acid ester of the formula (I) as a main component, including the structural unit derived from a monomer having a polar functional group, and further including any aromatic ring derived from the formula (I) The acrylic resin of the structural unit other than the monomer is a main component of the adhesive composition, and is preferably 60% by weight or more and 80% by weight or more of the entire acrylic resin.

The weight average molecular weight (Mw) of the acrylic resin, which is the main component of the adhesive composition, by standard polystyrene conversion of gel permeation chromatography (GPC), is preferably in the range of 500,000 to 2 million. Conversion weight flat If the average molecular weight is 500,000 or more, the adhesion in a high-humidity environment will be improved, the possibility of floating and peeling between the glass substrate and the adhesive layer tends to decrease, and the reworkability tends to improve. , So it is better. In addition, if the weight average molecular weight is 2 million or less, when the adhesive layer is bonded to an optical film, even if the size of the optical film is changed, the adhesive layer will change in accordance with the change in the size. There is no difference between the brightness and the brightness at the center, and it is preferable to suppress whitening and staining. The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually in the range of about 2 to about 10.

The acrylic resin may be composed of only those having a relatively high molecular weight as described above. In addition to such an acrylic resin, it may be composed of a mixture of acrylic resins different from the acrylic resin. The acrylic resin that can be mixed and used includes, for example, a structural unit derived from the (meth) acrylic acid ester represented by the aforementioned formula (I) as a main component and a weight average molecular weight in a range of 50,000 to 300,000.

Acrylic resin (a mixture of two or more types in combination) is a solution in which it is dissolved in ethyl acetate and the concentration is adjusted to 20% by weight. The viscosity at 25 ° C is less than 20Pa‧s, and the viscosity is 0.1 to The viscosity of 7Pa‧s is better. If the viscosity at this time is 20 Pa · s or less, the adhesiveness in a high humidity and heat environment will be improved, and the possibility of floating and peeling between the glass substrate and the adhesive layer will tend to decrease, and the reworkability will increase The tendency is better. Viscosity can be measured by a Brookfield viscometer.

Moreover, from the viewpoint of showing adhesiveness, acrylic resin The glass transition temperature of the acrylic resin is preferably in a range of -10 to -60 ° C. The glass transition temperature of the resin can be measured by a differential scanning calorimeter (DSC).

The acrylic resin constituting the adhesive composition can be produced by various known methods such as a solution polymerization method, a block polymerization method, a suspension polymerization method, or an emulsion polymerization method using water as a medium. In the production of this acrylic resin, a polymerization initiator can usually be used. The polymerization initiator is used in an amount of about 0.001 to 5 parts by weight based on 100 parts by weight of the total of all the monomers used in the production of the acrylic resin. In addition, the acrylic resin can be produced by a method in which polymerization is performed by active energy rays such as ultraviolet rays.

As the polymerization initiator, a thermal polymerization initiator or a photopolymerization initiator can be used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone and the like. Examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane) -1-carboxonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxypentyl) Nitrile), dimethyl-2,2'-azobis (2-methylpropionate), 2,2'-azobis (2-hydroxymethylpropionitrile) azo compounds; such as laurel Base peroxide, tertiary butyl hydroperoxide, benzophenone peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxide dicarbonate, dicarbonate peroxide Organic peroxides of dipropyl ester, tert-butyl peroxyneodecanoate, tert-butyl peroxy 2-methylpropionate, (3,5,5-trimethylhexyl) peroxide; Such as potassium persulfate, ammonium persulfate, inorganic peroxide of hydrogen peroxide, etc. Also, you can use and As the polymerization initiator, a redox-based initiator such as a peroxide and a reducing agent is used.

As for the method for producing an acrylic resin, among the methods described above, a solution polymerization method is preferred. To list and explain specific examples of the solution polymerization method, the desired monomers and organic solvents may be mixed, and a thermal polymerization initiator may be added in a nitrogen gas environment. The temperature is about 40 to 90 ° C, preferably 60. Method of stirring to about 80 ° C for about 3 to 10 hours. In addition, in order to control the reaction, a monomer or a thermal polymerization initiator may be added continuously or intermittently during the polymerization, or may be added in a state of being dissolved in an organic solvent. Among them, organic solvents can be used, for example, aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propanol and isopropanol; such as acetone and methyl ethyl Ketones, ketones of methyl isobutyl ketone, and the like.

(Silane compound)

The adhesive composition of the present invention may contain a silane compound in addition to the aforementioned acrylic resin. Thereby, when bonding the optical film with an adhesive of the present invention to a glass substrate such as a liquid crystal cell, the adhesion between the adhesive layer and the glass substrate can be improved. The acrylic resin before the cross-linking agent is prepared may contain a silane compound.

The silane compound is a compound having at least one alkoxysilyl group in the molecule. In the present invention, from the viewpoint of suppressing the deterioration of optical performance in the endurance test, the silane compound is used in a molecule that does not contain an epoxy group or a primary amine group (one that does not contain an epoxy group and does not include a primary amine group) .

Examples of the compound having at least one alkoxysilyl group in the molecule include XR ⁵ -Si-R ⁶ _n (OR ⁷ ) _3-n (III) represented by the following formula (III).

In the above formula (III), R ⁵ represents an alkylene group having 1 to 7 carbon atoms, or at least one methylene group constituting the alkylene group is selected from -NH-, -O-, -CO-, and -S- is a substituted group of at least one type. R ⁶ represents an alkyl group having 1 to 3 carbon atoms, and R ⁷ represents an alkyl group having 1 to 3 carbon atoms. Here, n represents an integer from 0 to 2. In addition, X in the formula (III) represents a mercapto group, a vinyl group, a styryl group, a methacrylic group, an acrylic group, an isocyanate group, an acid anhydride structure, or a halogen.

Specific examples of the compound corresponding to the above formula (III) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, vinyltrimethoxysilane, and vinyltrimethoxy Ethoxysilane, vinyl ginseng (2-methoxyethoxy) silane, p-styrenetrimethoxysilane, 3-methacryl methoxypropyltrimethoxysilane, 3-methacryl Oxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-propenefluorene Oxypropyltrimethoxysilane, 3-trimethoxysilylpropylsuccinic anhydride, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, and the like.

As for the silane compound, in addition to the compound corresponding to the above formula (III), S-4,5-dihydrothiazol-2-ylN-3- (triethoxysilyl) propane can also be used. Thiocarbamate, 1- (3- (triethoxysilyl) propyl ) -3- (pyridin-2-yl) urea and the like.

Furthermore, a compound having the following formula (IV) and having two or more alkoxysilyl groups in the molecule may be used.

In the above formula (IV), R ⁸ represents an alkylene group having 1 to 7 carbon atoms, or at least one methylene group constituting the alkylene group is selected from -NH-, -O-, -CO-, and -S- is a substituted group of at least one type. Further, R ⁹ represents an alkyl group having 1 to 3 carbon atoms, R ¹⁰ represents an alkyl group having 1 to 3 carbon atoms, and m is an integer of 0 to 2.

To give specific examples corresponding to the compound of formula (IV), there are trimeric isohydrogenate (3-trimethoxysilylpropyl) ester and trimeric isohydrogenate (3-triethoxysilyl) Propyl esters, etc.

The silane compound used in the present invention may also be a polysiloxane oligomer type. Even if it is an oligomeric type, it is preferable that it does not have an epoxy group or a primary amine group in a molecule | numerator. When a polysiloxane oligomer is represented as a (monomer)-(monomer) copolymer, the following is mentioned.

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxyoxide Based silane copolymer, Copolymers containing mercaptopropyl, such as 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer; mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane -Tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, mercaptomethyltriethoxysilane-tetraethoxysilane copolymer, and other copolymers containing mercaptomethyl ; 3-methacryloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methyl Propylene alkoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-methacryl propyltriethoxysilane-tetraethoxysilane copolymer, 3-methylpropylene Ethoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methyl Propylene propylene methoxypropylmethyl diethoxysilane-tetramethoxysilane copolymer, 3-methacryl methoxypropylmethyldiethoxysilane-tetraethoxy base Copolymers containing methacryloxypropyl groups such as silane copolymers; 3-acryloxypropyltrimethoxysilane-tetramethoxysilane copolymers, 3-acryloxypropyltrimethoxysilane -Tetraethoxysilane copolymer, 3-propenyloxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-propenyloxypropyltriethoxysilane-tetraethoxysilane Copolymer, 3-propenyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-propenyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer , 3-propenyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-propenyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer, etc. Copolymer of propylene methoxypropyl; vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethylsiloxane Oxysilane copolymer, Vinyltriethoxysilane-tetraethoxysilane copolymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, vinylmethyldimethoxysilane-tetraethoxysilane copolymer Polymer, vinylmethyldiethoxysilane-tetramethoxysilane copolymer, vinylmethyldiethoxysilane-tetraethoxysilane copolymer, and other copolymers containing vinyl groups; the above-mentioned silane compounds You can use 2 or more types together.

These silane compounds are liquid in most cases. In the adhesive composition, the compounding amount of the silane compound is generally used at a ratio of about 0.01 to 10 parts by weight based on 100 parts by weight of the solid content of the acrylic resin (when two or more kinds are used), and it is preferably used It is used in a proportion of 0.05 to 5 parts by weight, more preferably in a proportion of 0.1 to 1 part by weight. If the compounding amount of the silane compound is 0.01 parts by weight or more, the adhesion between the adhesive layer and the glass substrate is improved, so it is preferable. In addition, if the blending amount is 10 parts by weight or less, it is preferred that the silane compound tends to be prevented from oozing out of the adhesive layer.

(Antistatic agent)

In the present invention, in order to impart conductivity to the adhesive layer and improve the antistatic property of the optical film with the adhesive, in addition to the acrylic resin and the silane compound, an adhesive composition containing an antistatic agent can be further formulated. . The antistatic agent is preferably an antistatic agent having an inorganic cation.

Examples of the inorganic cation include alkali metal cations and alkaline earth metal cations. Examples of the alkali metal that can be used as the cationic component include lithium, sodium, and potassium. Examples of the alkaline earth metals include beryllium, magnesium, and calcium. Among them, alkali metals are preferred, lithium and potassium are more preferred, and potassium is even more preferred.

The anionic component constituting the antistatic agent may be an organic anion or an inorganic anion. The inorganic anions include, for example: anions chloride [Cl ^-], bromine anion [Br ^-], iodide anion [I ^-], [tetrachloroaluminate anion AlCl ₄ ^-], [heptachlorodialuminate anion Al ₂ cl ₇ ^-], [tetrafluoroborate anion BF ₄ ^-], hexafluorophosphate anions [PF ₆ ^-], [perchlorate anion ClO ₄ ^-], nitrate anion [NO ₃ ^-], hexafluoro arsenic anions [AsF ₆ ^-], [hexafluoroantimonate anion SbF ₆ ^-], [hexafluoro niobate anions NbF ₆ ^-], six tantalum fluoride anions [TaF ₆ ^-], dicyanimide anion [(CN) ₂ N ^-] and the like.

Further, the organic anion includes, for example: acetate anion [CH ₃ COO ^-], trifluoroacetate anion [CF ₃ COO ^-], mesylate anion [CH ₃ SO ₃ ^-], trifluoromethanesulfonic ester anion [CF ₃ SO ₃ ^-], a - [p- toluenesulfonate anion _{-CH 3 C 6 H 4 SO 3} - ], bis (sulfo-fluoro-acyl) acyl imide anion [(FSO _{2) 2} N ^-], bis (trifluoromethane sulfonic acyl) acyl imide anion _{[(CF 3 SO 2) 2 N} - ], reference (trifluoromethane sulfonic acyl) methanation anions _{[(CF 3 SO 2) 3 C} - ], [dimethylsilylene phosphonate anion (CH _{3) 2} POO ^-], (poly) hydrogen fluoride anions [F (HF) _n ^- _n is about 1 to 3], [thiocyanate anion SCN ^- ], perfluoro butane sulfonate anion [C ₄ F ₉ SO ₃ ^-], bis (pentafluoroethane sulfonic acyl) acyl imide anion _{[(C 2 F 5 SO 2)} 2 N - ], perfluoro butyrate anion [C ₃ F ₇ COO ^-], (trifluoromethane sulfonic acyl) (trifluoromethane-carbonyl) acyl imide anion _{[(CF 3 SO 2) (CF} 3 CO) N - ], perfluoropropane [1,3-sulfonate anion ^{_{- O 3 S (CF 2)}} 3 SO 3 - ], a carbonate anion [C O ₃ ^2- ] etc.

Among these, an anionic component containing a fluorine atom, in particular, can impart excellent antistatic properties to the antistatic agent, and is therefore suitable for use. For example, a bis (fluorosulfonyl) fluorenimide anion and a hexafluorophosphate are preferably used. Anion, or bis (trifluoromethanesulfonyl) phosphonium imine anion. Among them, bis (fluorosulfonyl) fluorenimide anion and bis (trifluoromethanesulfonyl) fluorenimide anion are particularly preferably used.

Specific examples of the antistatic agent used in the present invention can be appropriately selected from the combination of the above-mentioned cationic component and anionic component. Specific compounds include the following.

‧Lithium salt:

Lithium hexafluorophosphate, lithium bis (fluorosulfonyl) fluorenimide, lithium bis (trifluoromethanesulfonyl) fluorenimide, lithium p-toluenesulfonate, and the like.

‧Sodium salt:

Sodium hexafluorophosphate, sodium bis (fluorosulfonyl) fluorenimide, sodium bis (trifluoromethanesulfonyl) fluorenimide, sodium p-toluenesulfonate, and the like.

‧ Potassium salt:

Potassium hexafluorophosphate, potassium bis (fluorosulfonyl) fluorenimide, potassium bis (trifluoromethanesulfonyl) fluorenimide, potassium p-toluenesulfonate, and the like.

Such antistatic agents can be used individually or in combination of two or more kinds. The antistatic agent is of course not limited to those listed above.

The antistatic agent is usually formulated at a ratio of 0.2 to 8 parts by weight with respect to 100 parts by weight of the solid content of the aforementioned acrylic resin (the total amount when two or more kinds are used). When the antistatic agent is blended in an amount of 0.2 parts by weight or more, the antistatic performance is improved, and therefore it is preferable, and if the amount is 8 parts by weight or less, durability is easily maintained, which is preferable. The blending ratio of the antistatic agent is preferably 0.5 part by weight or more and 3 parts by weight or less.

In the present invention, in addition to the acrylic resin and the silane compound, an antistatic agent is blended to impart conductivity to the adhesive layer, so that the optical film with the adhesive has excellent antistatic properties. Therefore, an optical laminated system to which such an optical film with an adhesive is applied has excellent thinness, lightness, good antistatic properties, and excellent durability.

(Crosslinking agent)

The adhesive composition of the present invention may contain a crosslinking agent in addition to the above-mentioned acrylic resin, silane compound, and antistatic agent. The cross-linking agent has at least 2 in the molecule and can be polarized with acrylic resin in particular. A functional group compound whose functional unit monomer is a cross-linked structural unit. Specifically, an isocyanate-based compound, an epoxy-based compound, an aziridine-based compound, a metal chelate compound, and the like can be exemplified.

An isocyanate-based compound used as a crosslinking agent is a compound having at least two isocyanate groups (-NCO) in the molecule. Specific compounds include, for example, methylphenyl diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, phenylene diisocyanate, hydrogenated diisocyanate, Diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and the like. In addition, the adducts of these isocyanate compounds after reacting with polyols such as glycerin or trimethylolpropane, or the isocyanate compounds as dimers, trimers, etc., can also be used as crosslinking agents for adhesives. . Two or more kinds of isocyanate-based compounds may be used in combination.

The epoxy-based compound used as a crosslinking agent is a compound having at least two epoxy groups in the molecule. Specific compounds include, for example, bisphenol A epoxy resin, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol diglycidyl ether, glycerol triglycidyl ether, 1,6-hexane Glycol diglycidyl ether, trimethylolpropane triglycidyl ether, N, N-diglycidyl aniline, N, N, N ', N'-tetraglycidyl-m-xylylene diamine, 1 , 3-bis (N, N'-diglycidylaminomethyl) cyclohexane and the like. You may mix and use 2 or more types of epoxy compounds.

The aziridine-based compound used as a cross-linking agent is a compound having at least two so-called ethyleneimines of a three-membered ring skeleton composed of one nitrogen atom and two carbon atoms. Specific compounds can be listed Examples include diphenylmethane-4,4'-bis (1-aziridinecarboxamide), toluene-2,4-bis (1-aziridinecarboxamide), triethylenemelamine, isophthalate Formamidine bis-1- (2-methylaziridine), ginsane-1-aziridinylphosphine oxide, hexamethylene-1,6-bis (1-aziridinecarboxamide), Trimethylolpropane-gins-β-aziridinylpropionate, tetramethylolmethane-gins-β-aziridinylpropionate, and the like.

Examples of the metal adducts used as the cross-linking agent include acetoacetone or acetone complexed with polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, and zirconium.醯 Ethyl acetate compounds.

Among these cross-linking agents, an isocyanate-based compound is preferably used, and in particular, diphenyl diisocyanate, methylphenyl diisocyanate, hexamethylene diisocyanate, or the Adducts of isocyanate compounds such as glycerol or trimethylolpropane, or mixtures of isocyanate compounds such as dimers, trimers, etc., or those in which these isocyanate compounds are mixed. Examples of suitable isocyanate-based compounds include methylphenyl diisocyanate, adducts obtained by reacting methylphenyl diisocyanate with a polyol, and dimers of methylphenyl diisocyanate. And terpolymer of methylphenylene diisocyanate, and an adduct obtained by reacting hexamethylene diisocyanate, hexamethylene diisocyanate with a polyol, and hexamethylene diisocyanate Dimer of methylene and terpolymer of hexamethylene diisocyanate.

The cross-linking agent is usually formulated at a ratio of 0.1 to 1 part by weight based on 100 parts by weight of acrylic resin (the total amount when two or more types are used). If the compounding amount of the cross-linking agent is 0.1 parts by weight or more, the durability of the adhesive layer tends to be improved, so it is preferable, and if it is 1 part by weight or less, the resin film with the adhesive is applied to the film. For a liquid crystal display device The whitening is less noticeable, so it is better.

(Other ingredients constituting the adhesive composition)

The adhesive composition described above may further contain a cross-linking catalyst, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, a resin other than an acrylic resin, and the like. In addition, an ultraviolet curable compound is blended in the adhesive composition, and after forming the adhesive layer, it is irradiated with ultraviolet rays to harden it to form a harder adhesive layer.

When the adhesive composition contains both a cross-linking agent and a cross-linking catalyst, the adhesive layer can be prepared by curing in a short time. The obtained resin film with an adhesive can suppress the occurrence of floating and peeling between the resin film and the adhesive layer, or suppress the generation of air bubbles in the adhesive layer, and the reworkability becomes better. Examples of the crosslinking catalyst include: hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, ethylenediamine, triethylenetetramine, isophoronediamine , Amine compounds such as trimethylene diamine, polyamine resin and melamine resin. When an amine-based compound is formulated as a cross-linking catalyst in the adhesive composition, the cross-linking agent is preferably an isocyanate-based compound.

Each of the components constituting the adhesive composition is mixed in a solvent-dissolved state to prepare an adhesive composition, which is coated on a suitable substrate film and dried to form an adhesive layer. The substrate film used therein is generally a plastic film, and typical examples thereof include a release film subjected to a release treatment. The release film may be, for example, the surface of an adhesive layer on which a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate is formed. Polysilicon treatment Processor, etc.

[Optical film with adhesive]

In the optical film with an adhesive of the present invention, the sum of the thickness of the polarizing film and the thickness of the adhesive layer is 55 μm or less. Thereby, for example, the optical laminated body in which the optical film with an adhesive is applied to a glass substrate is thin and lightweight, and has excellent durability.

The thickness of the polarizing film is preferably 30 μm or less, more preferably 1 μm or more, and even more preferably 3 to 25 μm. If the thickness of the polarizing film is 30 μm or less, the shrinkage of the polarizing film in a high-temperature environment can be suppressed. Therefore, there is a possibility of floating and peeling between the polarizing film and the adhesive layer, or between the adhesive layer and the glass substrate. There is a tendency to decrease. When the thickness is 1 μm or more, the handling property of the polarizing film tends to be improved. As for a polarizing film, the thinner the thickness, the more easily it is affected by the antistatic agent or the silane compound contained in the adhesive layer, and the optical performance tends to deteriorate in the durability test. According to the adhesive layer of the present invention, even when such a thin polarizing film is used, it becomes a person having excellent optical durability.

Moreover, the thickness of the adhesive layer is preferably 45 μm or less, more preferably 10 μm or more, and even more preferably 10 to 25 μm. When the thickness of the adhesive layer is 45 μm or less, the adhesiveness in a high-humidity heat environment is improved, the possibility of floating and peeling between the glass substrate and the adhesive layer tends to be reduced, and the reworkability is improved. Tends to be better. Moreover, if the thickness is 10 μm or more, even if it is bonded to an adhesive The size of the optical film of the layer changes, and the adhesive layer also changes in accordance with the change of the size, so there is no difference between the brightness of the peripheral portion of the liquid crystal cell and the brightness of the center portion, and there is a tendency to suppress whitening and stain .

The adhesive layer is formed on the polarizing film. For example, the aforementioned adhesive composition can be pre-coated on the release film to form an adhesive layer, and then a polarizing film can be laminated on the obtained adhesive layer. A method of applying an adhesive composition to a film to form an adhesive layer, and attaching a release film to the adhesive surface is performed. In order to protect the surface of the adhesive layer, the release film is preferably adhered to the surface of the adhesive layer until use.

The optical film with an adhesive of the present invention is an adhesive that is exposed by peeling the release film from the adhesive layer in a state where a protective film described later is provided on the side opposite to the adhesive layer of the polarizing film. The laminated body is made of alkali-free glass to form a laminated body, and the laminated body is placed in a hot and humid environment at a temperature of 80 ° C and a relative humidity of 90% for 24 hours, and further placed in an environment of a temperature of 23 ° C and a relative humidity of 60% for 24 hours. When the durability test is performed, the amount of change in polarization (ΔPy) is in the range of -1 to 0 percent, and the amount of change in monomer transmission rate (△ Ty) at this time may be 2 percent or less. If the amount of change in the degree of polarization and the transmittance of the monomer is large, the appearance of the polarizer will be poor. Furthermore, if such a polarizing plate is applied to a liquid crystal display device, problems such as a decrease in contrast may occur. Therefore, it is preferable that the amount of change before and after the endurance test is small.

The above-mentioned optical characteristics can be obtained by calculating the difference between the visual acuity correction monomer transmittance (Ty) and the visual acuity correction polarization (Py) before and after the endurance test. The visual sensitivity correction unit transmittance (Ty) and the visual sensitivity correction polarization (Py) are measured by using a spectrophotometer with an integrating sphere and measuring the MD transmission rate and TD transmission rate in the range of 380 to 780 nm. Based on the following formulae (1) and (2), the individual transmittance and polarization of each wavelength are obtained. Further, according to JIS Z 8701: 1999 "Color Representation Method-XYZ Color System and X ₁₀ Y ₁₀ Z _{The 10} degree color system (2 light field (C light source)) was obtained by correcting visual sensitivity. The "MD transmittance" is the transmittance when the direction of polarized light emitted from Glan-Thompson prism is parallel to the transmission axis of the polarizer sample, and is expressed by the following formula (1) And (2) is indicated as "MD". In addition, the "TD transmittance" is the transmittance when the direction of polarized light emitted by Glan-Thomson 稜鏡 is perpendicular to the transmission axis of the polarizer sample, and is expressed in equations (1) and (2). The middle system is indicated as "TD".

Monomer penetration rate (%) = (MD + TD) / 2 .. Formula (1)

Polarization (%) = ((MD-TD) / (MD + TD)) × 100 .. Formula (2)

〔Protective film〕

The optical film with an adhesive of the present invention is preferably an area layer protective film on the side opposite to the side where the adhesive layer is formed with the polarizing film. As the protective film, a transparent resin film can be used. Examples of the transparent resin constituting the protective film include cellulose resins represented by triethyl cellulose and diethyl cellulose, acrylic resins, polyester resins, polyolefin resins, polycarbonate resins, and polyetheretherketone. Resin, polyfluorene resin, etc. The transparent resin constituting the protective film may also contain ordinary additives, such as ultraviolet absorbers, infrared absorbers, organic dyes, pigments, inorganic pigments, antioxidants, antistatic agents, surfactants, lubricants, and dispersants. , Heat stabilizers, etc. Among them, ultraviolet absorbers are suitable for use because they improve weather resistance. Examples of the ultraviolet absorbers include salicylate-based compounds, benzophenone-based compounds, benzotriazole-based compounds, and Based compounds, cyanoacrylate based compounds, nickel salt based compounds, and the like. Protective film: Cellulose resin film and acrylic resin film, such as triacetyl cellulose film, are suitable.

The cellulose-based resin film is a film formed of a part or all of the esterified cellulose, and examples thereof include films formed of cellulose acetate, propionate, butyrate, and mixed esters thereof. Among them, triacetam cellulose film, diacetam cellulose film, cellulose acetate propionate film, cellulose acetate butyrate film and the like are preferably used.

Cellulose-based resin films are easily available on the market. For example, the brand names are: "FUJITAC TD" sold by FUJIFILM Corporation, and "Konica Minolta TAC Film KC" sold by Konica Minolta Opto Co., Ltd. "Wait.

The acrylic resin film is a film formed by mixing an acrylic resin with a methacrylic resin and additives added as necessary, and melt-kneading the acrylic resin. The methacrylic resin is a polymer mainly composed of a methacrylate. The methacrylic resin may be a homopolymer of one type of methacrylate, or a copolymer of methacrylate and other methacrylates or acrylates. Examples of the methacrylate include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate. The number of carbon atoms in the alkyl group is usually about 1 to 4. In addition, acrylates obtained by copolymerization with methacrylates are based on alkyl acrylates. Examples include methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. The number of carbon atoms of the alkyl group is usually about 1 to 8. In addition to these, the copolymer may include a compound having at least one polymerizable carbon-carbon double bond in the molecule, such as an aromatic vinyl compound such as styrene, or a vinyl cyanide compound such as acrylonitrile.

The acrylic resin can improve the durability of the film, and therefore may have a ring structure in the polymer main chain. The ring structure is preferably a heterocyclic structure such as a cyclic acid anhydride structure, a cyclic amidine structure, and a lactone ring structure. Specific examples include cyclic anhydride structures such as glutaric anhydride structure and succinic anhydride structure, cyclic fluorene imine structures such as glutarimide structure and succinimide structure, butyrolactone and valerolactone, etc. Lactone ring structure.

From the viewpoint of impact resistance and film-forming properties of the film, the acrylic resin film preferably contains acrylic rubber particles. The amount of the acrylic rubber particles that can be contained in the acrylic resin is preferably 5% by weight or more, more preferably 10% by weight or more, based on 100% by weight of the acrylic resin. Although the upper limit of the amount of acrylic rubber particles is not a critical value, if the amount of acrylic rubber particles is too large, the surface hardness of the film will decrease, and when the film is subjected to a surface treatment, the solvent resistance to the organic solvent in the surface treatment agent will be reduced. Will fall. Therefore, the amount of the acrylic rubber particles that can be contained in the acrylic resin is preferably 80% by weight or less, and more preferably 60% by weight or less.

The thickness of the protective film described above is not particularly limited, but is usually 1 to 100 μm. The thickness of the film is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, still more preferably 80 μm or less, still more preferably 50 μm or less, and still more preferably 30 μm or less.

When an adhesive-attached optical film with the above-mentioned protective film is laminated on the visible side of the liquid crystal cell, a surface treatment layer may be provided on the opposite side of the surface where the protective film is in contact with the polarizing film, if necessary. The surface treatment layer may be, for example, a hard coat layer, an anti-glare layer, an anti-reflection layer, an antistatic layer, or the like. Among these, a plurality of layers may be provided.

In addition, when the laminated optical film with a protective film and an adhesive is disposed on the back side of the liquid crystal cell, a known system such as a brightness enhancement film, a light condensing film, and a diffusion film may be disposed on the liquid crystal cell. Instead of providing the above-mentioned surface treatment layer, various optical films on the back side of the substrate are provided.

The method for adhering the protective film and the polarizing film is not particularly limited, and a known adhesive or adhesive can be used. Examples of the adhesive include water-based adhesives which are composed of an aqueous solution or an aqueous dispersion, and which evaporate the water of the solvent to develop the adhesive force; and are hardened by irradiating active energy rays such as ultraviolet rays to develop the adhesive activity Energy ray hardening type adhesives and the like. Examples of the adhesive include general acrylic adhesives. Of course, the adhesive of the present invention may be used.

[Optical Laminate]

The optical laminated body of the present invention is a laminated optical film with an adhesive on a liquid crystal cell or the like. Laminating an optical film with an adhesive to a glass substrate is, for example, as long as the release film is peeled off from the optical film with an adhesive obtained in the manner described above, and the exposed adhesive layer is bonded to the surface of the glass substrate. can. Here, the glass substrate includes, for example, a glass substrate for a liquid crystal cell, anti-glare glass, and glass for sunglasses. Among them, in front of the liquid crystal cell The glass substrate on the front side (identification side) is laminated with an adhesive-attached optical film (upper polarizer) through an adhesive layer, and the glass substrate on the back side of the liquid crystal cell is laminated with another adhesive-attached optical layer An optical laminated body made of a thin film (lower polarizing plate) is preferred because it can be used as a liquid crystal display device. Examples of the material of the glass substrate include soda-lime glass, low-alkali glass, and alkali-free glass.

The optical laminated body of the present invention can be suitably used for a liquid crystal display device. Such a liquid crystal display device can be suitably used in, for example, liquid crystal displays for personal computers such as notebooks, desktops, and PDAs (Personal Digital Assistant), televisions, car-mounted displays, electronic dictionaries, digital cameras, digital cameras, and desks. Supercomputers, clocks, etc.

(Example)

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, parts and% indicating the amount used and even the content are based on weight unless otherwise specified.

In the following examples, the weight average molecular weight is 4 "TSKgel XL" manufactured by TOSOH Co., Ltd., and 1 "Shodex GPC KF-802" manufactured by Showa Denko Corporation and sold by Zhaoguang Trading Co., Ltd. A total of 5 columns were arranged in series as a column in a GPC device, and tetrahydrofuran was used as the eluent. The sample concentration was 5 mg / mL, the sample introduction amount was 100 μL, the temperature was 40 ° C, and the flow rate was 1 mL / min. Styrene conversion value.

First, an example of polymerization of an acrylic resin as a main component for producing an adhesive composition is shown.

[Polymerization Example 1]

In a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer, 81.8 parts of ethyl acetate, 60 parts of butyl acrylate, 28.0 parts of methyl acrylate, 4.0 parts of 2-hydroxyethyl acrylate, and 2- (acrylate) A mixed solution of 8.0 parts of 2-phenoxyethoxy) ethyl ester was replaced with nitrogen in the apparatus to make it oxygen-free and the internal temperature was raised to 55 ° C. Then, the entire amount of a solution in which 0.14 parts of azobisisobutyronitrile (polymerization initiator) was dissolved in 10 parts of ethyl acetate was added. One hour after the starter was added, the temperature was maintained, and then the internal temperature was maintained at 54 to 56 ° C. Ethyl acetate was continuously added to the reaction container at an addition rate of 17.3 parts / hour, and the concentration of the acrylic resin became 35%. At this time, the addition of ethyl acetate was stopped, and the temperature was maintained at that temperature for 12 hours from the start of the ethyl acetate addition. Finally, ethyl acetate was added to adjust the concentration of the acrylic resin to 20% to prepare an ethyl acetate solution of the acrylic resin. The weight average molecular weight Mw of the obtained acrylic resin by polystyrene conversion of GPC was 1.3 million, and the molecular weight distribution Mw / Mn was 4.2.

Next, examples and comparisons of examples of producing a polarizing film with an adhesive by preparing an adhesive composition using the acrylic resin manufactured above, and setting an adhesive layer formed of the composition on one side of a polarizing film, example. In the following examples, the following are used for the cross-linking agent, the antistatic agent, and the silane compound.

<Crosslinking agent>

TAKENATED-110N: Ethyl acetate solution of trimethylolpropane adduct of phenylene diisocyanate (solid content concentration 75%) was obtained from Mitsui Chemicals Co., Ltd. Hereinafter, it is represented by "D110N".

<Antistatic agent>

K-FSI: Potassium N, N-bis (fluorosulfonyl) fluorenimide (solid), obtained from Mitsubishi Materials Electronic Chemicals Co., Ltd. Hereinafter, it is expressed as "KFSI".

<Silane compound>

X-41-1818: Polysiloxyalkoxy oligomer (liquid), obtained from Shin-Etsu Chemical Industry Co., Ltd. Hereinafter, it is represented by "X-41-1818".

X-12-965: Ginseng- (3-trimethoxysilylpropyl) trimeric isohydrogenate (liquid), obtained by Shin-Etsu Chemical Industry Co., Ltd. Hereinafter, it is represented by "X-12-965".

X-12-967C: 3-trimethoxysilylpropylsuccinic anhydride (liquid), obtained by Shin-Etsu Chemical Industry Co., Ltd. Hereinafter, it is represented by "X-12-967C".

KBM-802: 3-mercaptopropylmethyldimethoxysilane (liquid), obtained by Shin-Etsu Chemical Industry Co., Ltd. Hereinafter, it is represented by "KBM-802".

KBM-403: 3-Glycidoxypropyltrimethoxysilane (liquid), obtained from Shin-Etsu Chemical Industry Co., Ltd. Hereinafter, it is represented by "KBM-403".

KBM-602: N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane (liquid), obtained from Shin-Etsu Chemical Industry Co., Ltd. Hereinafter, it is represented by "KBM-602".

[Examples 1 to 4, Comparative Examples 1 and 2]

(a) Preparation of adhesive composition

Using the 20% ethyl acetate solution of the acrylic resin obtained in Polymerization Example 1, the above-mentioned antistatic agent and each of Table 1 were mixed in an amount of each shown in Table 1 with respect to 100 parts of each solid content. The amount of the cross-linking agent and the amount of the silane compound shown in Table 1 were each added to ethyl acetate such that the solid content concentration became 13% to prepare adhesive compositions. The cross-linking agent was obtained as an ethyl acetate solution, but the added amount shown in Table 1 is its solid content.

(b) Production of adhesive sheet

Each adhesive composition prepared in the above (a) was coated on a polyethylene terephthalate film subjected to a release treatment using a coater so that the thickness after drying became 20 μm [by Lintec Corporation] The obtained product name "T204" is called a release treatment surface of a separator], and was dried at 100 ° C for 1 minute to prepare an adhesive sheet.

(c) Fabrication of polarizing film

A polyvinyl alcohol film having an average degree of polymerization of about 2400, a degree of saponification of 99.9 mol% or more, and a thickness of 30 μm is subjected to dry uniaxial extension to about 4 times, After being kept in a tight state and directly immersed in pure water at 40 ° C for 1 minute, it was immersed in an aqueous solution having a weight ratio of iodine / potassium iodide / water of 0.05 / 10/100 at 28 ° C for 60 seconds. Thereafter, it was immersed in an aqueous solution having a weight ratio of potassium iodide / boric acid / water at 8.5 / 7.5 / 100 at 68 ° C. for 300 seconds. Next, it was washed with pure water at 10 ° C for 20 seconds, and then dried at 65 ° C to prepare a polarizing film having iodine adsorbed and oriented on a polyvinyl alcohol film stretched through one axis. The thickness of the polarizing film was 11 μm.

(d) Fabrication of polarizing plate with adhesive

On one side of the polarizing film prepared in (c) above, a transparent protective film made of a triethyl cellulose cellulose film with a thickness of 25 μm was attached via an adhesive made of an aqueous solution containing a polyvinyl alcohol resin [Konica Minolta Opto Co., Ltd.'s trade name is "KC2UA"], making polarizing plates. Next, the polarizer film surface of the laminating machine was laminated on the surface opposite to the separator film (adhesive layer) of the adhesive sheet prepared in (b) above, and the temperature was 23 ° C and the relative humidity was 65%. The conditions were matured for 7 days, and a polarizing plate with a protective film and an adhesive was laminated.

(e) Evaluation of durability of optical laminates

The polarizing plate with a protective film laminated with a protective film produced in the above (d) was cut into a size of 30 mm × 30 mm, the separation film was peeled off, and an alkali-free glass was bonded to the exposed adhesive layer side [Corning Company Manufactured under the trade name "EAGLE XG"] to make an optical laminate. For this optical multilayer body, a spectrophotometer with an integrating sphere [product name "V7100" manufactured by JASCO Corporation] was used to measure the MD transmittance and TD transmittance in the range of 380 to 780 nm. Equations (1) and (2) calculate the individual transmittance and polarization at each wavelength, and further based on JIS Z 8701: 1999 "Color Representation Method-XYZ Table Color System and X ₁₀ Y ₁₀ Z ₁₀ Table Color System" The visual sensitivity correction was performed on the 2 degree visual field (C light source), and the visual sensitivity correction unit transmittance (Ty) and the visual sensitivity correction polarization (Py) before the endurance test were obtained. In addition, the optical multilayer system uses the triacetate cellulose film side of the polarizing plate as the detector side, and is set on a spectrophotometer with an integrating sphere so that light enters from the glass side.

Then, the optical laminated body was left for 24 hours in a hot and humid environment at a temperature of 80 ° C and a relative humidity of 90%, and then left for 24 hours in an environment at a temperature of 23 ° C and a relative humidity of 60%, in the same manner as before the endurance test. Then, Ty and Py after the endurance test were obtained. After that, the Py and Ty before the test are subtracted from the Py and Ty after the test, respectively, and the change amount before and after the endurance test is calculated, and the change in the degree of polarization (△ Py) and the change in the transmittance of the monomer (△ Ty) are calculated. . The results are shown in Table 1.

Liquid (solid content concentration 75%), obtained from Mitsui Chemicals Co., Ltd., trade name: TAKENATED-110N. KFSI: Potassium N, N-bis (fluorosulfonyl) fluorenimide (solid), obtained from Mitsubishi Materials Electronic Chemicals Co., Ltd. X-41-1818: Polysiloxyalkoxy oligomer (liquid), obtained from Shin-Etsu Chemical Industry Co., Ltd. X-12-965: Ginseng- (3-trimethoxysilylpropyl) trimeric isohydrogenate (liquid), obtained by Shin-Etsu Chemical Industry Co., Ltd. X-12-967C: 3-trimethoxysilylpropylsuccinic anhydride (liquid), obtained by Shin-Etsu Chemical Industry Co., Ltd. KBM-802: 3-mercaptopropylmethyldimethoxysilane (liquid), obtained from Shin-Etsu Chemical Industry Co., Ltd. KBM-403: 3-glycidoxypropyltrimethoxysilane (liquid), obtained from Shin-Etsu Acquired by Chemical Industry Co., Ltd. KBM-602: N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane (liquid), obtained from Shin-Etsu Chemical Industry Co., Ltd. <Optical durability> △ Py: change in polarization degree △ Ty: change in transmittance of a monomer

As shown in Table 1, it can be seen that Examples 1 to 4 using the polarizing plate with an adhesive of the present invention are compared with Comparative Examples 1 and 2 using a polarizing plate with an adhesive that exceeds the requirements of the present invention. After the high-humidity heat endurance test, the amount of change in polarized light (△ Py) and the amount of change in monomer transmittance (△ Ty) are low, so the deterioration of the polarizing film in a high-humidity environment can be suppressed, and the durability is excellent.

(Industrial availability)

The adhesive-attached optical film of the present invention is bonded When it is used for glass, it has excellent durability and is suitable for use in liquid crystal display devices.

Claims (11)

An optical film with an adhesive is an optical film with an adhesive on which an adhesive layer is formed on one side of a polarizing film. The adhesive layer is composed of a compound represented by formula (III) or formula ( IV) The compound shown in the figure and the adhesive composition of acrylic resin. The sum of the thickness of the polarizing film and the thickness of the adhesive layer is 55 μm or less. XR ⁵ -Si-R ⁶ _n (OR ⁷ ) _{3- n} (III) In the formula (III), R ⁵ represents an alkylene group having 1 to 7 carbon atoms, or at least one methylene group constituting the alkylene group is selected from -NH-, -O-, -CO -, And -S- substituted with at least one or more types of groups; R ⁶ represents an alkyl group having 1 to 3 carbon atoms, R ⁷ represents an alkyl group having 1 to 3 carbon atoms; wherein n represents an integer of 0 to 2; X represents a mercapto group, a vinyl group, a styryl group, a methacrylic group, an acrylic group, a halogen atom, an isocyanate group, or an anhydride structure; In formula (IV), R ⁸ represents an alkylene group having 1 to 7 carbon atoms, or at least one methylene group constituting the alkylene group is selected from -NH-, -O-, -CO-, and- S- is substituted with at least one or more types of groups; and R ⁹ represents an alkyl group having 1 to 3 carbon atoms, R ¹⁰ represents an alkyl group having 1 to 3 carbon atoms, and m is an integer of 0 to 2. The adhesive-attached optical film according to item 1 of the scope of the patent application, wherein the adhesive composition further comprises an antistatic agent having an inorganic cation. The adhesive-attached optical film according to item 2 of the scope of the patent application, wherein the inorganic cation is an alkali metal or alkaline earth metal cation. The adhesive-attached optical film according to item 3 of the scope of the patent application, wherein the inorganic cation is an alkali metal cation. According to the optical film with an adhesive agent described in any one of the scope of claims 1 to 4, the thickness of the polarizing film is 30 μm or less. According to the optical film with an adhesive agent described in any one of the scope of claims 1 to 4, the thickness of the aforementioned adhesive agent layer is 45 μm or less. The optical film with an adhesive agent as described in any one of the scope of claims 1 to 4, wherein a protective film is laminated on the side opposite to the adhesive layer of the aforementioned optical film with an adhesive agent. The optical film with an adhesive agent according to any one of claims 1 to 4 of the scope of application for a patent, wherein a release film is laminated on the adhesive agent layer. The optical film with an adhesive as described in item 7 of the scope of the patent application, wherein the laminated body obtained by laminating the adhesive through the aforementioned optical film with an adhesive on an alkali-free glass at a temperature of 80 ° C, phase The change in polarization after 24 hours of storage at 90% humidity is in the range of -1 to 0 percent. The optical film with an adhesive as described in item 7 of the scope of the patent application, wherein the laminated body obtained by laminating the adhesive through the aforementioned optical film with an adhesive on an alkali-free glass at a temperature of 80 ° C, After 24 hours of storage at 90% relative humidity, the change in monomer transmission rate is less than 2%. An optical laminated body is an optical film with an adhesive as described in any one of the scope of claims 1 to 7 of the patent application, and is adhered to the liquid crystal cell on the side of the adhesive layer.