KR20070046721A - Adhesive - Google Patents

Abstract

THF of an adhesive in the adhesive which consists of acrylic resins (1) and (2) as a durable adhesive which does not produce the external appearance change of an optical laminated body in repeating heating and cooling under high humidity conditions and high heat conditions. Insoluble matter X (%) and Y (%) represented by Formula (III) provide the adhesive which satisfy | fills (I) and (II).

40 ≤ X ≤ 70 (I)

-0.51X + 41 <Y <0.45X + 24 (II)

             Y = B- (100-X) × C / 100 (III)

(In formula, B shows the weight percentage of the component of 300,000 or more of molecular weight in the mixture of (1) and (2), C shows the weight percentage of the component of 300,000 or more of molecular weight in THF melt | dissolution component of an adhesive. )

(1): Acrylic resin whose weight average molecular weights are 50,000-250,000.

(2): The acrylic resin containing (b) and whose weight average molecular weights are 1,000,000-1,500,000.

(b): Monomer containing a polar functional group and an olefinic double bond.

Description

Adhesive {ADHESIVE}

1 shows the correlation of X and Y in Table 4; An example is shown as a ((circle)) comparative example, (right) a straight down line shows Y = -0.15X + 41, and a right up straight line shows Y = 0.45X + 24.

This invention relates to an adhesive and the optical laminated body containing this adhesive.

The liquid crystal cell generally used for liquid crystal display devices, such as TFT and STN, has a structure where the liquid crystal component was clamped between two glass base materials. And optical films, such as a polarizing film and retardation film, are laminated | stacked on the surface of this glass base material through the adhesive which has an acrylic resin as a main component. And the optical laminated body formed by laminating | stacking a glass substrate, an adhesive, and an optical film in order, first, manufactures the optical film with an adhesive obtained by laminating | stacking an adhesive on an optical film, and then laminates a glass base material on the surface of an adhesive. The method is generally used.

Since the optical film with an adhesive has a large dimensional change by expansion and contraction under heat or wet heat conditions, it is easy to cause curls, etc., and it foams in the adhesive layer of the optical laminated body obtained, or lifts, peels, etc. between an adhesive layer and a glass base material. There was a problem that this occurred. In addition, under heat or wet heat conditions, the distribution of residual stress acting on the optical film with pressure-sensitive adhesive becomes uneven, and stress concentration occurs in the outer peripheral portion of the optical laminate, resulting in whitening in TN liquid crystal cell (TFT) and color unevenness in STN liquid crystal cell. There was a problem that occurred.

In order to solve such a problem, Unexamined-Japanese-Patent No. 2000-109771 has proposed the adhesive which has a high molecular weight acrylic resin of the weight average molecular weight 600,000-2,000,000, and the low molecular weight acrylic resin of the weight average molecular weight 500,000 or less as a main component.

Disclosure of the Invention

Challenges the invention seeks to solve

In recent years, attempts have been made to use liquid crystal displays for in-vehicle systems, such as car navigation systems. However, in-vehicle use has also been required to have durability such that foaming, lifting, peeling, discoloration and the like do not occur even under high temperature and high humidity conditions.

MEANS TO SOLVE THE PROBLEM The present inventors examined the optical laminated body obtained by laminating | stacking an optical film on the adhesive which crosslinks the composition of the high molecular weight acrylic resin and the low molecular weight acrylic resin which satisfy | fills the conditions described in the said patent document with a crosslinking agent, and whitening, It has been found that durability under high humidity conditions or high heat conditions may not be satisfied.

An object of the present invention, while suppressing the whitening of the optical laminate, under the high humidity conditions or high heat conditions, lifting, peeling, foaming in the pressure-sensitive adhesive layer between the glass substrate and the pressure-sensitive adhesive layer in the optical laminate A pressure-sensitive adhesive having excellent durability that hardly causes changes in appearance such as whitening, lifting, peeling, foaming, and discoloration even after repeated heating and cooling: an optical film with a pressure-sensitive adhesive made of the pressure-sensitive adhesive and an optical film, and the optical with pressure-sensitive adhesive It is providing the optical laminated body formed by laminating | stacking an optical film and a glass substrate through the adhesive layer of a film.

Means to solve the problem

Under these circumstances, the present inventors conducted a thorough examination of the pressure-sensitive adhesive and found that a specific pressure-sensitive adhesive could solve these problems, and completed the present invention.

That is, this invention WHEREIN: The adhesive which crosslinks the following acrylic resin (1) and (2) with a crosslinking agent WHEREIN: By weight percentage X (%) in the tetrahydrofuran insoluble content with respect to an adhesive, and it is Formula (III) An adhesive in which the weight percentage Y (%) of the high molecular weight component in the tetrahydrofuran insoluble content of the displayed adhesive satisfies the formulas (I) and (II); An optical film with pressure-sensitive adhesive formed by laminating the pressure-sensitive adhesive on both surfaces or one side of the optical film; It is an optical laminated body formed by laminating | stacking a glass base material on the adhesive layer of this optical film with an adhesive.

       40 ≤ X ≤ 70 (I)

-0.51X + 41 <Y <0.45X + 24 (II)

             Y = B- (100-X) × C / 100 (III)

(In formula, X shows the weight percentage (%) of the tetrahydrofuran insoluble content with respect to an adhesive, B represents the weight percentage of the component of 300,000 or more of molecular weight in the mixture of acrylic resin (1) and (2), C represents the weight percentage of the component of 300,000 or more of molecular weight in the tetrahydrofuran melt of an adhesive.)

Acrylic resin (1): Acrylic resin whose weight average molecular weight which has a structural unit (structural unit (a)) derived from the following monomer (a) as a main component is 50,000-250,000.

(a): (meth) acrylic acid ester represented by Formula (A)

(In formula, R <_1> represents a hydrogen atom or a methyl group, R <_2> represents a C1-C14 alkyl group or an aralkyl group. The hydrogen atom of the alkyl group of R <_2> or the aralkyl group is a C1-C10 alkoxy group. May be substituted.)

Acrylic resin (2): The acrylic resin containing a structural unit (a structural unit (b)) which has a structural unit (a) as a main component and originates in the following monomer (b), The weight average molecular weight of this resin is 1,000,000-1,500,000. Acrylic resin.

(b): A monomer containing at least one polar functional group selected from the group consisting of a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, an oxetanyl group, an aldehyde group and an isocyanate group and one olefinic double bond in the molecule.

To practice the invention  Best form for

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

The monomer (a) used for acrylic resin (1) and (2) of this invention is (meth) acrylic acid ester represented by Formula (A).

In formula, R <_1> represents a hydrogen atom or a methyl group, R <_2> represents a C1-C14 alkyl group or aralkyl group. The hydrogen atom of the aralkyl group of R ₂ or the hydrogen atom of the alkyl group may be substituted with a C 1-10 alkoxy group.

Here, as the monomer (a), for example, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, iso-butyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, acrylic esters such as iso-octyl acrylate, lauryl acrylate, stearyl acrylate, cyclohexyl acrylate, isobornyl acrylate, benzyl acrylate, methoxyethyl acrylate and ethoxymethyl acrylate; Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, iso-octyl methacrylate Methacrylic acid esters such as lauryl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, isobornyl methacrylate, benzyl methacrylate, methoxyethyl methacrylate and ethoxymethyl methacrylate Etc. can be mentioned.

As the monomer (a), two or more different monomers (a) may be used.

As content of the structural unit (structural unit (a)) derived from the monomer (a) in the acrylic resin (1) of this invention, it is 60 weight part or more normally with respect to 100 weight part of acrylic resin (1). It is preferably 70 parts by weight or more.

Moreover, as content of the structural unit (a) in the acrylic resin (2), it is about 70-99.9 weight part normally with respect to 100 weight part of acrylic resin (2), Preferably it is 90-99.6 weight part It is enough.

The structural unit (structural unit (b)) derived from the monomer (b) is an essential component of the acrylic resin (2), and may be contained in the acrylic resin (1) as an optional component. Here, the monomer (b) contains at least one polar functional group selected from the group consisting of a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, an oxetanyl group, an aldehyde group and an isocyanate group, and one olefinic double bond in the molecule. It is a monomer.

As a specific example of monomer (b), acrylic acid, methacrylic acid, maleic acid, itaconic acid etc. are mentioned as monomer (b) whose polar functional group is a carboxyl group, and a monomer (b) whose polar functional group is a hydroxyl group, for example. As examples, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like can be given. Moreover, as a monomer (b) whose polar functional group is an amide group, for example, acrylamide, methacrylamide, N, N- dimethylaminopropyl acrylamide, diacetonediamide, N, N-dimethyl acrylamide, N, N -Diethyl acrylamide, N-methylol acrylamide, etc. are mentioned.

As a monomer (b) whose polar functional group is an epoxy group, glycidyl acrylate, glycidyl methacrylate, 3, 4- epoxycyclohexyl methyl acrylate, 3, 4- epoxy cyclohexyl methyl methacryl The rate etc. are mentioned. Here, the monomer which an oxygen atom comprises a 3-membered ring and a 7-membered ring like 3, 4- epoxycyclohexyl methyl acrylate, 3, 4- epoxy cyclohexyl methyl methacrylate, has a highly reactive epoxy group In the monomer (b).

As a monomer (b) whose polar functional group is an oxetanyl group, For example, oxetanyl (meth) acrylate, 3-oxetanylmethyl (meth) acrylate, (3-methyl-3- oxetanyl) methyl (Meth) acrylate, (3-ethyl-3-oxetanyl) methyl (meth) acrylate, etc. are mentioned. Moreover, as a monomer (b) whose polar functional group is an amino group, N, N- dimethylaminoethyl acrylate, allylamine, etc. are mentioned, for example, As a monomer (b) whose polar functional group is an isocyanate group, it is 2, for example. -Methacryloyloxyethyl isocyanate etc. are mentioned, As a monomer (b) whose polar functional group is an aldehyde group, acrylaldehyde etc. are mentioned, for example.

As these monomers (b), you may use combining 2 or more types of different monomers (b), For example, the monomer (b) containing at least 1 sort (s) of polar functional group chosen from the group which consists of a hydroxyl group, an amino group, and an epoxy group. It is not preferable to use the monomer (b) containing a polar functional group capable of reacting at the same time as the combination of the monomer (b) containing an isocyanate group because gelation occurs during the polymerization of the acrylic resin.

Especially as a monomer (b), the monomer (b) whose polar functional group is a hydroxyl group, and the monomer (b) whose polar functional group is a carboxyl group are preferable, and 4-hydroxybutyl (meth) acrylate, acrylic acid, and 2-hydroxy are especially preferable. Preferred is oxyethyl (meth) acrylate.

When using a monomer (b) for an acrylic resin (1), as content of the structural unit (b) contained in an acrylic resin (1), it is 0.1-20 weight weight normally with respect to 100 weight part of acrylic resin (1). It is wealth. When content of a structural unit (b) is 20 weight part or less, since it exists in the tendency for the peeling and peeling off between a glass substrate and an adhesive layer to be preferable, it is preferable.

As content of the structural unit (b) contained in the acrylic resin (2), it is about 0.1-30 weight part normally with respect to 100 weight part of acrylic resin, Preferably it is about 0.5-10 weight part. When content of a structural unit (b) is 0.1 weight part or more, since the cohesion force of resin obtained tends to improve, and if it is 30 weight part or less, even if the dimension of an optical film changes, an adhesive layer follows the dimensional change and fluctuates. Therefore, since there is no difference between the brightness of the periphery of the liquid crystal cell and the brightness of the central part, whitening and color unevenness tend to be suppressed, which is preferable.

In addition, in order to make the value of Y mentioned later larger than -0.15X + 41, what is necessary is just to reduce the uncrosslinked component in an adhesive, ie, to reduce the low molecular weight component melt | dissolved in THF. Specifically, what is necessary is just to increase the structural unit (b) which can react with the crosslinking agent in the acrylic resin (1) which is a low molecular weight component, or to increase the use weight part of the acrylic resin (1) in a crosslinking agent.

Moreover, in order to make Y's formula smaller than 0.45X + 24, what is necessary is just to increase the uncrosslinked component in an adhesive, ie, what is necessary is just to increase the low molecular weight component melt | dissolved in THF. Specifically, in the acrylic resin (1) which is a low molecular weight component, what is necessary is just to reduce the structural unit (b) which can react with a crosslinking agent, or to reduce the use weight part of the acrylic resin (1) in a crosslinking agent.

As a weight ratio (non-volatile content) of the acrylic resin (1) and (2) used for the adhesive of this invention, an acrylic resin (1) is 10-50 weight part normally with respect to 100 weight part of adhesive resin compositions, Preferably Is about 20 to 40 parts by weight. If the acrylic resin (1) is 10 parts by weight or more, even if the size of the optical film changes, since the pressure-sensitive adhesive layer follows and changes in the dimensional change, there is no difference between the brightness of the periphery of the liquid crystal cell and the brightness of the central part. Since color nonuniformity tends to be suppressed, it is preferable, and when acrylic resin (1) is 50 weight part or less, the adhesiveness under high temperature, high humidity improves, there exists a tendency for the lifting and peeling between a glass substrate and an adhesive layer to fall, and also It is preferable because the reworkability tends to be improved.

When producing the acrylic resins (1) and (2) used in the present invention, it is further a monomer different from the monomers (a) and (b), and has a cyclic structure of at least one olefinic double bond and a 5-membered ring in the molecule. You may superpose | polymerize with the monomer (c) containing. Here, as a monomer (c), For example, the monomer which contains one olefinic double bond and an alicyclic structure in a molecule | numerator (henceforth an alicyclic monomer); And a monomer containing one olefinic double bond and a heterocyclic structure in the molecule (hereinafter, may be referred to as a heterocyclic monomer).

The alicyclic structure in the alicyclic monomer is usually a cycloparaffin structure or cycloolefin structure having 5 or more carbon atoms, preferably about 5 to 7 carbon atoms. Moreover, in a cycloolefin structure, an olefinic double bond is contained in an alicyclic structure.

As a monomer which contains one olefinic double bond and an alicyclic structure in a specific molecule | numerator, isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, and trimethylcyclohexyl acryl Acrylate esters having alicyclic structures such as acrylate, tert-butylcyclohexyl acrylate, cyclohexyl alpha ethoxy acrylate, cyclohexyl phenyl acrylate: isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate Cycloaliphatic compounds such as cyclododecyl methacrylate, methylcyclohexyl methacrylate, trimethylcyclohexyl methacrylate, tert-butylcyclohexyl methacrylate, cyclohexyl alpha ethoxy methacrylate, cyclohexylphenyl methacrylate Methacrylic acid ester etc. which have a structure are illustrated.

As an alicyclic monomer, especially isobornyl acrylate, cyclohexyl acrylate, isobornyl methacrylate, cyclohexyl methacrylate, and dicyclopentanyl acrylate are preferable because it is easy to obtain.

Moreover, as an acrylate containing two or more alicyclic structures, biscyclohexyl methyl itaconate, a dicyclo octyl itaconate, a dicyclo dodecyl methyl succinate, etc. are mentioned, The vinyl cyclohexyl acetate containing a vinyl group is mentioned. Equivalent is monomer (d).

The heterocyclic structure in the heterocyclic monomer is a complex in which at least one methylene group in an alicyclic hydrocarbon group having 5 or more carbon atoms, preferably 5 to 7 carbon atoms is substituted with a hetero atom such as a nitrogen atom, an oxygen atom, or a sulfur atom It is ventilation.

Specifically, acryloyl morpholine, vinyl caprolactam, N-vinyl-2-pyrrolidone, tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, caprolactone modified tetrahydrofurfuryl acrylate, etc. Can be mentioned. In addition, an olefinic double bond may be contained in the heterocycle, such as 2,5-dihydrofuran. As a monomer containing one olefinic double bond and a heterocyclic structure in a molecule | numerator, N-vinylpyrrolidone, vinyl caprolactam, and acryloyl morpholine are especially preferable.

You may use a different monomer (c) as monomer (c).

As content of the structural unit (structural unit (c)) derived from the monomer (c) contained in the acrylic resin (1) or (2) of this invention, it is about 10 weight part normally with respect to 100 weight part of acrylic resins. It is as follows. When the structural unit (c) is contained, the pressure-sensitive adhesive layer follows the dimensional change even if the optical film changes in size, so that there is no difference between the brightness of the periphery of the liquid crystal cell and the brightness of the central part, so that whitening and color unevenness occur. It may be suppressed.

In addition, when manufacturing acrylic resin (1) and (2) used for this invention, you may superpose | polymerize with a vinylic monomer (d). A vinyl monomer (d) is a monomer different from monomer (a)-(c), and is a monomer which has at least 1 vinyl group in a molecule | numerator, For example, a vinyl ester, a vinyl halide, a vinylidene halide, a conjugated diene compound, Styrene-based monomers, nitrogen-containing aromatic vinyls, and (meth) acrylonitrile.

Here, as vinyl ester, Monovinyl ester, such as vinyl acetate, a vinyl propionate, a vinyl butyrate, a vinyl 2-ethylhexanoate, a vinyl laurate; Divinyl esters, such as adivinic acid adipic acid and divinyl sebacate, are mentioned.

Vinyl chloride, vinyl bromide, etc. are illustrated as vinyl halide, vinylidene chloride, etc. are illustrated as vinylidene halide, and acrylonitrile and methacrylonitrile are illustrated as (meth) acrylonitrile.

A conjugated diene compound is an olefin which has a conjugated double bond in a molecule | numerator, As a specific example, isoprene, butadiene, chloroprene, etc. are mentioned.

As the styrene monomer, styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, diethyl styrene, triethyl styrene, propyl styrene, butyl styrene, hexyl styrene, heptyl styrene, octyl styrene, fluoro styrene, chloro styrene , Bromostyrene, dibromostyrene, iodine styrene, nitrostyrene, acetyl styrene, methoxy styrene, divinylbenzene and the like. As nitrogen containing aromatic vinyl, vinylpyridine, vinyl carbazole, etc. are mentioned, for example.

As the monomer (d), plural kinds of different monomers (d) may be used.

The structural unit (d) derived from the monomer (d) contained in the acrylic resin (1) or (2) is usually 5 parts by weight or less, preferably 0.05 parts by weight or less, particularly with respect to 100 parts by weight of the acrylic resin. Preferably, it is preferable that it does not contain substantially.

Moreover, when manufacturing acrylic resin (1) and (2) used for this invention, as a monomer different from monomer (a)-(d), the monomer (e) which contains several olefinic double bond in a molecule | numerator You may contain it. As the monomer (e), for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, 1,3,5-triacryloylhexahydro-S-triazine, tetramethylol (Meth) acrylates, such as methane tetraacrylate; Bis (meth) acrylamides such as methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide and N, N-diallyl acrylamide; Allyl (meth) acrylate, triallyl isocyanurate, triallylamine, tetraallyl pyromellitate, N, N, N ', N'- tetraallyl-1,4-diaminobutane, tetraallyl ammonium salt, etc. Can be mentioned.

As the monomer (e), plural kinds of different monomers (e) may be used.

The structural unit (e) derived from the monomer (e) contained in the acrylic resin (1) or (2) is usually 5 parts by weight or less, preferably 0.05 parts by weight or less, particularly with respect to 100 parts by weight of the acrylic resin. Preferably, it is preferable that it does not contain substantially.

As a manufacturing method of the acrylic resin (1) used for this invention, a solution polymerization method, an emulsion polymerization method, a block polymerization method, suspension polymerization method, etc. are mentioned, for example.

Moreover, in manufacture of acrylic resin (1), a polymerization initiator is used normally. About 0.1-5 weight part of polymerization initiators are used with respect to a total of 100 weight part of all the monomers used for manufacture of an acrylic resin (1).

As a polymerization initiator, a thermal polymerization initiator, a photoinitiator, etc. are illustrated, As a photoinitiator, 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone etc. are mentioned, for example. Can be. As a thermal polymerization initiator, it is 2,2'- azobisisobutyronitrile, 2,2'- azobis (2-methylbutyronitrile), 1,1'- azobis (cyclohexane-1, for example). -Carbonitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2, Azo compounds, such as 2'- azobis (2-methyl propionate) and 2,2'- azobis (2-hydroxymethyl propionitrile); Lauryl peroxide, tert-butylhydroperoxide, benzoyl peroxide, tert-butylperoxybenzoate, cumene hydroperoxide, diisopropylperoxydicarbonate, di-n-propylperoxydicarbonate, tert-butylperoxyneo Organic peroxides such as decanoate, tert-butylperoxy pivalate and (3,5,5-trimethylhexanoyl) peroxide; Inorganic peroxides such as potassium persulfate, ammonium persulfate, hydrogen peroxide and the like. Moreover, the redox system initiator etc. which used together the thermal polymerization initiator and the reducing agent can also be used as a polymerization initiator.

As a manufacturing method of the acrylic resin (1), the solution polymerization method is especially preferable. As a specific example of the solution polymerization method, a desired monomer and an organic solvent are mixed to prepare a monomer concentration of 20% by weight or more, preferably 30 to 60% by weight, and then a polymerization initiator is added under a nitrogen atmosphere, The method of stirring about 40 to 90 degreeC, Preferably it is about 60 to 80 degreeC, about 3 to 10 hours, etc. are mentioned. Moreover, in order to control reaction, you may add the monomer to be used and a polymerization initiator during superposition | polymerization, or after melt | dissolving in an organic solvent.

Here, as an organic solvent, For example, aromatic hydrocarbons, such as toluene and xylene; Ester types such as ethyl acetate and butyl acetate; aliphatic alcohols such as n-propyl alcohol and isopropyl alcohol; Ketones, such as methyl ethyl ketone and a methyl isobutyl ketone, etc. are mentioned.

As a molecular weight of the acrylic resin (1) obtained in this way, the weight average molecular weight by standard polystyrene conversion of a gel permeation chromatography (GPC) is 50,000-250,000 normally. If the weight average molecular weight is 50,000 or more, since the adhesiveness under high temperature, high humidity improves, there exists a tendency for the lifting and peeling between a glass substrate and an adhesive layer to fall, and reworkability tends to improve, and it is preferable, and a weight average molecular weight If it is 250,000 or less, even if the dimension of an optical film changes, since an adhesive layer tracks and changes to the dimension change, there exists no difference between the brightness of the peripheral part of a liquid crystal cell, and the brightness of a center part, and there exists a tendency for whitening and color nonuniformity to be suppressed. It is preferable because it is.

As a manufacturing method of the acrylic resin (2) used for this invention, a solution polymerization method, an emulsion polymerization method, a block polymerization method, suspension polymerization method, etc. are mentioned, for example, A solution polymerization method is especially preferable. .

As a specific example of the solution polymerization method, after mixing a desired monomer and an organic solvent, the monomer concentration is prepared in 40 weight% or more, Preferably, 50-60 weight% of mixed liquid, and a polymerization initiator is 0.001-0.2 in nitrogen atmosphere. About a weight part is added, The method of stirring for about 8 hours or more, Preferably it is about 10 to 12 hours, etc. at about 40-90 degreeC, Preferably it is about 50-70 degreeC.

The polymerization initiator used in the acrylic resin (2) is the same polymerization initiator as used in the acrylic resin (1). In addition, as the organic solvent, the same organic solvent as used in the acrylic resin (1) is used.

As a molecular weight of the acrylic resin (2) obtained in this way, the weight average molecular weight (Mw) by standard polystyrene conversion of a gel permeation chromatography (GPC) is 1,000,000-1,500,000. When a weight average molecular weight is 1,000,000 or more, since the adhesiveness under high temperature, high humidity improves, there exists a tendency for the lifting and peeling between a glass substrate and an adhesive layer to fall, and there exists a tendency for rework property to improve, and it is preferable. If the weight average molecular weight is 1,500,000 or less, even if the size of the optical film changes, the pressure-sensitive adhesive layer follows the size change and changes, so that there is no difference between the brightness of the periphery of the liquid crystal cell and the brightness of the central part, and whitening and color unevenness are suppressed. It is preferable because it tends to be.

The crosslinking agent used for the adhesive of this invention has two or more functional groups which can bridge | crosslink in the polar functional group contained in the acrylic resin (2), Specifically, an isocyanate type compound, an epoxy type compound, and a metal chelate type compound And aziridine compounds.

Here, an isocyanate type compound is tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, Tetramethyl xylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate, etc. are mentioned, The adduct body and isocyanate compound which made polyol, such as glycerol and a trimethylol propane, react with the said isocyanate compound, It is a crosslinking agent of this invention also about what was set as 2, trimer, etc. Among these, the adduct of tolylene diisocyanate is especially preferable.

As an epoxy type compound, For example, bisphenol-A epoxy resin, ethylene glycol glycidyl ether, polyethylene glycol glycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1, 6-hexane Diol diglycidyl ether, trimethylolpropanetriglycidyl ether, diglycidyl aniline, N, N, N ', N'-tetraglycidyl-m-xylenediamine and 1,3-bis (N, N'- diglycidylaminomethyl) cyclohexane etc. are mentioned.

Examples of the metal chelate compound include compounds in which acetylacetone and ethyl acetoacetate are coordinated with polyvalent metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium. Can be mentioned.

As an aziridine type compound, it is N, N-diphenylmethane-4,4'-bis (1-aziridine carboxyl), N, N'-toluene-2,4-bis (1-aziri, for example). Dinecarboxamide), triethylenemelamine, bisisophthaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, N, N'-hexamethylene-1,6-bis ( 1-aziridinecarboxide), trimethylolpropane-tri-β-aziridinylpropionate, tetramethylolmethane-tri-β-aziridinylpropionate, and the like.

You may use 2 or more types of crosslinking agents as a crosslinking agent. As a usage-amount of the crosslinking agent (non-volatile content) in an adhesive, with respect to a total of 100 weight part (non-volatile content) of acrylic resin (1) and (2), it is about 0.8-5 weight part normally, Preferably it is 1-3 It is about parts by weight. Although Unexamined-Japanese-Patent No. 2000-109771 specifically uses 0.1 weight part and 0.15 weight part crosslinking agent with respect to a total of 100 weight part (non-volatile content) of acrylic resin (1) and (2), the quantity of a crosslinking agent is If it is 0.8 weight part or more, the uncrosslinked component in an adhesive will decrease, and the value of Y mentioned later will become larger than -0.15X + 41, As a result, durability, such as lifting and peeling between a glass substrate and an adhesive layer, will become favorable. desirable. Moreover, when it is 5 weight part or less, the uncrosslinked component in an adhesive increases and the value of Y mentioned later tends to become smaller than 0.45X + 24, As a result, since the followability of an adhesive layer is excellent with respect to the dimensional change of an optical film, Whitening and color nonuniformity tend to decrease, which is preferable.

Especially, if the polar functional group contained in acrylic resin (1) is a hydroxyl group, and a crosslinking agent is an isocyanate type compound, since the reactivity of this hydroxyl group and a crosslinking agent is excellent, the quantity of the hydroxyl group in acrylic resin (1), and the quantity of a crosslinking agent will be The value of Y mentioned later can be controlled simply by controlling. In particular, the adduct body which made polyol, such as glycerol and trimethylol propane, react with tolylene diisocyanate and tolylene diisocyanate, dimerized tolylene diisocyanate, and trimerized tolylene diisocyanate is selected from the group which consists of these. At least 1 type of crosslinking agent is preferable.

The pressure-sensitive adhesive of the present invention is a pressure-sensitive adhesive formed by crosslinking the acrylic resins (1) and (2) thus obtained with a crosslinking agent, wherein the weight percentage X (%) of the THF insoluble content relative to the pressure-sensitive adhesive is represented by the formula (III) The weight percentage Y (%) of the high molecular weight component in the tetrahydrofuran insoluble content of the pressure-sensitive adhesive satisfies the formulas (I) and (II).

        40≤ X ≤70 (Ⅰ)

-0.51X + 41 <Y <0.45X + 24 (II)

             Y = B- (100-X) × C / 100 (III)

In the formula, X represents the weight percentage (%) of the tetrahydrofuran insoluble content with respect to the pressure-sensitive adhesive. Specifically, it measures by the following method.

(i) The adhesion layer (thickness 25 micrometers) of about 8 cm x 8 cm area, and the metal mesh of SUS 304 mesh (about 10 cm x about 10 cm, weight Wm) are attached.

(Ii) The weight (Ws) of the deposit obtained in (i) is weighed, folded four times to fix the adhesive layer inward, and fixed with a stapler, and then weighed (Wb).

(Iv) The mesh obtained in (ii) is put into a 125 ml glass container, and 10 ml of THF is added thereto for immersion, and then the glass container is stored at room temperature for 6 days.

(Iii) A mesh is taken out of a glass container, dried at 120 degreeC for 24 hours, and it weighs (Wa), and calculates a gel fraction based on following Formula.

X (% by weight) = [{Wa- (Wb-Ws) -Wm} / (Ws-Wm)] × 100

If X is 70% or less, the crosslinking density is low, which is excellent in flexibility, and whitening and color unevenness tend to be suppressed, and X is preferably 40% or more because cohesive force is improved and durability tends to be improved. Do.

B in Formula (III) shows the weight percentage of the high molecular weight component of 300,000 or more of molecular weight in the mixture of acrylic resin (1) and (2), and C is the high molecular weight of 300,000 or more in THF melt | dissolution powder of an adhesive. Indicate the weight percentage of components. That is, Y defined by Formula (III) represents the weight percentage of THF insoluble content in an adhesive, ie, the weight average molecular weight 300,000 or more of the component bridge | crosslinked by the crosslinking agent.

In addition, the said molecular weight and its weight percentage are measured by standard polystyrene conversion of gel permeation chromatography (GPC).

If Y is less than 0.45X + 24, a crosslinking density will become low, since it is excellent in flexibility, and whitening and a color nonuniformity tend to be suppressed, it is preferable. Cohesion force improves that Y is -0.51X + 41 or more, and there exists a tendency which durability improves.

In order that the adhesive of this invention may improve the adhesiveness of an adhesive layer and a glass substrate, it is preferable to contain a silane type compound. The silane compound may be any of a monomer and an oligomer. As a silane type compound monomer, vinyl trimethoxysilane, vinyl triethoxysilane, vinyl tris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropyl methyl dimeth, for example. Methoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxy Silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3- Mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethyl Silane and the like. As oligomer of a silane compound, 3-mercaptopropyl trimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyl trimethoxysilane-tetraethoxysilane copolymer, mercaptomethyl trimethoxysilane- Tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, mercaptomethyltriethoxysilane-tetraethoxysilane Polymer, 3-methacryloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloxypropyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetramethoxysilane copolymer, 3-Aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetramethoxysil Copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 2- (3,4 epoxycyclohexyl) ethyltrimethoxysilane-tetraethoxysilane copolymer, tetraethoxysilane copolymer Etc. can be mentioned.

You may use two or more types of silane compounds for the adhesive of this invention.

As the usage-amount (solution) of a silane compound in an adhesive, it is about 0.0001-10 weight part normally with respect to 100 weight part (non-volatile content) of an acrylic resin composition, Preferably it is used in the quantity of 0.01-5 weight part. . Since the adhesiveness of an adhesive layer and a glass substrate improves that the quantity of a silane type compound is 0.0001 weight part or more, it is preferable. Moreover, since the amount of a silane compound is 10 weight part or less, since there exists a tendency to suppress bleeding out of a silane compound from an adhesive layer, it is preferable.

The pressure-sensitive adhesive of the present invention contains an acrylic resin (1), an acrylic resin (2) and a crosslinking agent as described above, and preferably contains a silane compound, but further contains a crosslinking catalyst, weathering stabilizer, tackifier, and plasticizer. , Softeners, dyes, pigments, inorganic fillers and the like may be blended.

Especially, if a crosslinking catalyst and a crosslinking agent are mix | blended with an adhesive, the optical film with an adhesive can be prepared by aging for a short time, and the optical laminated body containing this film is a thing which lifted, peeling off, and an adhesive layer between an optical film and an adhesive layer. Foaming in the inside may be suppressed and the rework property may be excellent.

Examples of the crosslinking catalyst include hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, triethylenediamine, polyamino resin, melamine resin, and the like. An amine compound etc. are mentioned. When using an amine compound as a crosslinking catalyst for an adhesive, an isocyanate type compound is preferable as a crosslinking agent.

The optical film with an adhesive of this invention consists of the said adhesive and an optical film, As the manufacturing method, the adhesive diluted in the organic solvent is apply | coated on a peeling film, for example, and it is 0.5-10 at 60-120 degreeC. The mixture is heated for about a minute to distill off the organic solvent to obtain an adhesive layer. Subsequently, after attaching an optical film to an adhesive layer, the temperature is 23 degreeC, the atmospheric high surface of 65% of humidity, 5 to 20 degree of maturation are also aged, and after a crosslinking agent fully reacts, the peeling film is peeled off and the method of obtaining an optical film with an adhesive is obtained. ; After obtaining an adhesive layer similarly to the above, after combining the obtained laminated | multilayer body of the peeling film and an adhesive layer in multiple layers so that a peeling film and an adhesive layer may be alternated, the atmosphere high surface of temperature 23 degreeC and humidity 65%, After maturing for about 5 to 20 days, and the crosslinking agent reacts sufficiently, the release film is peeled off, an optical film is attached instead, and the peeling film is further peeled off to obtain an optical film with pressure-sensitive adhesive.

Here, a peeling film is a base material at the time of forming an adhesive layer. It may be a base material which protects an adhesive layer from foreign substances, such as dust, when it preserves during aging or as an optical film with an adhesive. As a specific example of a peeling film, the film which consists of various resins, such as a polyethylene terephthalate, a polybutylene terephthalate, a polycarbonate, and a polyacrylate, is made into a base material, and it carries out a mold release process to the bonding surface with the adhesive layer of this base material ( Silicon processing) etc. are mentioned.

As an optical film used for the optical film with an adhesive of this invention, it is a film which has an optical characteristic, for example, a polarizing film, retardation film, etc. are mentioned. A polarizing film is an optical film which has a function which emits polarized light with respect to incident light, such as natural light. As a polarizing film, the linear polarizing film which has the property which absorbs the linearly polarized light of the vibration surface parallel to an optical axis, and transmits the linearly polarized light which has the vibration surface which is a perpendicular plane, and the polarization which reflects the linearly polarized light of the vibration surface parallel to an optical axis The elliptical polarizing film etc. which laminated | stacked the separation film, the polarizing film, and the retardation film mentioned later are mentioned. As a specific example of a polarizing film, the thing in which the dichroic dye, such as iodine and a dichroic dye, was adsorption-oriented to the polyvinyl alcohol film uniaxially stretched, etc. are mentioned.

Retardation film is an optical film having optical anisotropy such as uniaxial or biaxial, for example, polyvinyl alcohol, polycarbonate, polyester, polyacrylate, polyimide, polyolefin, polystyrene, polysulfone, polyether By stretching a polymer film composed of sulfone, polyvinylidene fluoride / polymethyl methacrylate, liquid crystalline polyester, acetyl cellulose, cyclic polyolefin, ethylene-vinyl acetate copolymer saponified material, polyvinyl chloride and the like by about 1.01 to 6 times The stretched film obtained etc. are mentioned. Especially, the polymer film which uniaxially stretched and biaxially stretched polycarbonate or polyvinyl alcohol is preferable.

Examples of the retardation film include a uniaxial retardation film, a wide viewing angle retardation film, a low light modulus retardation film, a temperature compensated retardation film, an LC film (rod-shaped liquid crystal torsion alignment), a WV film (disc-shaped liquid crystal tilt alignment), and a NH film (rod Shape liquid crystal tilt orientation), VAC film (complete biaxially-oriented retardation film), newVAC film (biaxially-oriented retardation film), etc. are mentioned.

Moreover, what further adhered the board | substrate film (Protective Film) to one or both surfaces of these optical films is used suitably as an optical film. As a board | substrate film, For example, an acetyl cellulose type film, such as an acrylic resin film different from the acrylic resin of this invention, a cellulose acetate film, a polyester resin film, an olefin resin film, a polycarbonate resin film, a polyether ether ketone Resin films, polysulfone resin films, and the like. You may mix | blend ultraviolet absorbers, such as a salicylic acid ester type compound, a benzophenone type compound, a benzotriazole type compound, a triazine type compound, the cyanoacrylate type compound, and a nickel complex salt type compound, to a board | substrate film. Among the substrate films, acetylcellulose-based films are preferable.

The optical laminated body of this invention consists of an optical film with an adhesive, and a glass substrate. An optical laminated body can adhere and manufacture the adhesive layer and glass substrate of an optical film with an adhesive normally. Here, as a glass substrate, the glass substrate of a liquid crystal cell, bulletproof glass, glass for sunglasses, etc. are mentioned, for example. Especially, the adhesive layer of an optical film with an adhesive (top polarizing plate) is affixed on the glass substrate of the upper part of a liquid crystal cell, and the adhesive layer of another optical film with an adhesive (lower plate polarizing plate) is stuck to the glass substrate of a lower part of a liquid crystal cell. Since an optical laminated body can be used as a liquid crystal display device, it is preferable. As a material of a glass substrate, soda lime glass, low alkali glass, an alkali free glass, etc. are mentioned, for example.

Since the optical laminated body of this invention hardly generate | occur | produces cloudiness, adhesive residue, etc. on the surface of the glass substrate which contacted the adhesive layer even after peeling the optical film with an adhesive from an optical laminated body, it was again made to the peeled glass substrate. It is easy to stick | attach the optical film with an adhesive, ie, it is excellent in rework property.

Example

Hereinafter, an Example is given and this invention is demonstrated further more concretely. In addition, "part" and "%" in an Example are a basis of weight unless there is particular notice. In addition, the non volatile matter was performed by the measuring method based on J1S K-5407. Specifically, the pressure-sensitive adhesive solution is applied to an arbitrary weight and a chalet, and the residual non-volatile content weight after drying in an explosion-proof oven at 115 ° C. for 2 hours is expressed as a ratio with respect to the weight of the first measured solution. The weight average molecular weight was measured in standard polystyrene conversion using a device, and the sample concentration was 5 mg / ml, the sample introduction amount was 100 µl, and Tosoh Co., Ltd. was manufactured as two columns: TSKgel G6000H _XL 2 and TSKgel G5000H _XL 2 in order, in series. It was calculated | required using tetrahydrofuran as an eluate on the conditions of the temperature of 40 degreeC, and the flow rate of 1 ml / min using what was used.

<Production Example of Acrylic Resin>

(Polymerization example 1)

222 parts of ethyl acetate was poured into the reactor equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer, and the inside of the apparatus was replaced with nitrogen gas so as not to contain oxygen, and the internal temperature was raised to 75 ° C. After adding the total amount of the solution which melt | dissolved 0.5 part of azobisisobutyronitrile (it is called AIBN) in 12.5 parts of ethyl acetate, 36 parts of butyl acrylates as a monomer (a) and meta, maintaining internal temperature at 74-76 degreeC, meta A mixed solution of 44 parts of butyl acrylate and 20 parts of methyl acrylate was added dropwise into the reaction system over 3 hours. Thereafter, the mixture was kept at 74 to 76 ° C for 5 hours to complete the reaction. It was the weight average molecular weight 100,000 of polystyrene conversion of GPC.

(Polymerization Examples 2-5)

It was set as the monomer composition shown in Table 1, and it completed substantially similarly to the polymerization example 1, and completed reaction.

Monomer composition (parts by weight) Mw (× 10000) BA BMA MA 2HEA AA Polymerization Example 1 36 44 20 0 0 10 Polymerization Example 2 35.2 44 20 0.8 0 10 Polymerization Example 3 35 44 20 One 0 9 Polymerization Example 4 35 44 20 0 One 10 Polymerization Example 5 99.5 0 0 0.5 0 10

BA: Butyl acrylate, BMA: Butyl methacrylate

     MA: Methyl acrylate, 2HEA: 2-hydroxyethyl acrylate

AA: acrylic acid

(Polymerization example 6)

81.8 parts of acetone, 98.9 parts of butyl acrylate (hereinafter referred to as BA) as monomer (a) and 1.1 parts of acrylic acid (hereinafter referred to as AA) as monomer (b) to a reactor equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer After injecting the mixed solution, replacing the air in the apparatus with nitrogen gas to raise the internal temperature to 55 ° C without containing oxygen, 0.14 parts of azobisisobutyronitrile (hereinafter referred to as AIBN) was added to 10 parts of acetone. The total amount of the dissolved solution was added. 1 hour after the initiator addition, the acetone solvent was continuously added to the reactor at an addition rate of 17.3 parts by weight to hr so that the concentration of the acrylic resin from which the monomer was removed (hereinafter, referred to as reaction concentration) was 35% by weight. It was kept at 56 ° C for 12 hours, and finally, ethyl acetate solvent was added to adjust the reaction concentration to 20%. The weight average molecular weight 1,200,000 and Mw / Mn were 3.9.

(Polymerization examples 7-8)

It was set as the monomer composition shown in Table 2, and it carried out substantially similarly to the polymerization example 6, and completed reaction.

In Table 2, the monomer composition ratio, molecular weight, and molecular weight distribution of 8 from the polymerization example 6 were put together.

Monomer composition (parts by weight) Mw (× 10000) Mw / Mn BA AA HBA Polymerization Example 6 98.9 1.1 0 120 3.9 Polymerization Example 7 95 5 0 157 3.4 Polymerization Example 8 99 0 One 143 3.2

BA: Butyl acrylate, AA: Acrylic acid

HBA: 4-hydroxybutyl acrylate

(Example 1)

<Production Example of Adhesive>

Acrylic resin (1) and (2) were mixed at the weight ratio of Table 3, and the ethyl acetate solution of the acrylic resin composition was obtained. To 100 parts of nonvolatile matters of the obtained solution, two parts of adducts of a tolylene diisocyanate as a crosslinking agent (brand name: Colonate L, manufactured by Nippon Polyurethane Industry) (nonvolatile matters), and a silane compound (brand name: Y11597, manufactured by Torre Dow Corning) ) 0.1 part was mixed to obtain the pressure-sensitive adhesive of the present invention.

<Manufacture example of an optical film with an adhesive and an optical laminated body>

The pressure-sensitive adhesive thus obtained was applied to a release treatment surface of a polyethylene terephthalate film (Lintec, trade name: PET3811) released by using an applicator so that the thickness after drying was 25 μm, and dried at 90 ° C. for 1 minute. And sheet-like adhesive were obtained. Subsequently, as an optical film, the polarizing film (the film which has the 3-layered structure which interposed the triacetyl cellulose type protective film on both surfaces of what adsorbed and extended | stretched iodine to polyvinyl alcohol) was used, and on the optical film, After attaching the surface which has the obtained adhesive with a laminator, it aged for 10 days on conditions of the temperature of 23 degreeC, and humidity of 65%, and obtained the optical film with an adhesive in which the adhesive layer was formed. Subsequently, the optical film with pressure-sensitive adhesive was attached to both surfaces of a glass substrate for liquid crystal cell (manufactured by Corning Corporation, 1737) so as to be cross nicol, to obtain an optical laminate. When this is stored for 96 hours at 80 ° C and dry (heat resistance), and for 96 hours at 60 ° C and 90% RH (humidity and heat resistance), after heating to 60 ° C, the temperature is lowered to -20 ° C and 60 When the process of raising the temperature to 1 ° C. was performed for 1 cycle (1 hour) and stored for 100 cycles (thermal shock resistance, HS in Table 4), the durability in the optical laminate after storage, and the heat resistance conditions Whitening expression was visually observed. The results were classified into the following tips and shown in Table 4.

<Whitening of Optical Laminates>

Evaluation of the expression state of whitening was performed with the following four steps.

(Double-circle): Whitening is not seen at all.

(Circle): Whitening is hardly noticeable.

(Triangle | delta): A white flower is outstanding.

X: Whitening is observed remarkably.

<Durability of Optical Laminate>

Evaluation of durability was performed in the following four steps.

(Double-circle): Appearance change, such as lifting, peeling, foaming, is not seen at all.

(Circle): Almost no external appearance changes, such as lifting, peeling, and foaming, are seen.

(Triangle | delta): Appearance changes, such as lifting, peeling and foaming, are notable a little.

X: Appearance changes, such as lifting, peeling, foaming, are remarkably observed.

<Reworkability>

First, the optical laminated body was prepared to the test piece of 25 mm x 150 mm. Next, this test piece is affixed on the glass substrate for liquid crystal cells (Soda lime glass by Nippon Itagara Co., Ltd.) using the attachment apparatus (Fuji Plastic Machinery Co., Ltd. product "Ramipaka"), and 50 degreeC, 5 kg / Treatment was performed by autoclave for 20 minutes at cm 2 (490.3 kPa). Subsequently, after heat-processing at 50 degreeC for 2 hours, after storing for 48 hours in 50 degreeC oven, this adhesion test piece is peeled at 180 degree direction at the speed of 300 mm / min in 23 degreeC and 65% RH atmosphere of relative temperature, As a result of observing the glass plate surface state, it was favorable.

(Examples 2-16 Comparative Examples 1-8)

According to Example 1, acrylic resins (1) and (2) were mixed in the weight ratio shown in Table 3, to obtain an ethyl acetate solution of the acrylic resin composition. The crosslinking agent and the silane compound were mixed with 100 parts of nonvolatile matters of the obtained solution, and the adhesive of this invention was obtained.

Table 3 shows the mixing ratios of the acrylic resins (1) and (2), the type and amount of the crosslinking agent, the silane compound species and amount, and the weight percentage B of the components having a molecular weight of 300,000 or more in the mixture of the acrylic resins (1) and (2). It was.

The symbol of the crosslinking agent and silane compound of Table 3 is shown below.

Colonate L: Tolylene diisocyanate adduct manufactured by Nippon Polyurethane Industry Co., Ltd. "Colonate L"

D-140N: Mitsui Takeda Chemical Co., Ltd. isophorone diisocyanate adduct "Takenate D-140N"

FL-2: Tomica diisocyanate isocyanurate body "sumizu FL-2"

Y11597: Toray Dow Corning Co., Ltd. silane agent `` Y11597 ''

X-41-1805: Shin-Etsu Chemical Co., Ltd. silicone alkoxy oligomer "X-41-1805"

Table 4 shows the weight percent (%) of tetrahydrofuran insoluble to the pressure-sensitive adhesive X, the weight percentage (%) of the components having a molecular weight of 300,000 or more in the tetrahydrofuran dissolved content of the pressure-sensitive adhesive C, Y (= B- (100-X ) And C / 100) and whitening, heat resistance, moisture resistance, and HS durability.

The result of Table 4 was put together in FIG. The comparative example ((circle)) was shown by the Example as (▲).

Reworkability was all favorable.

[Industry availability]

The adhesive of this invention can be used as an adhesive suitable for optical laminated bodies, such as a TN liquid crystal cell (TFT), for example. Moreover, when the composition of this invention is used for the adhesive of STN liquid crystal cell, the color nonuniformity of the optical laminated body obtained can be suppressed.

The pressure-sensitive adhesive of the present invention is excellent in flexibility by controlling the amount of the low molecular weight component soluble in tetrahydrofuran (THF) in the pressure-sensitive adhesive, that is, the amount of uncrosslinked component in the pressure-sensitive adhesive, and the adhesiveness excellent in optical films and the like. It gives to an optical laminated body. Moreover, when the optical film with an adhesive which laminated | stacked the optical film and this adhesive is laminated | stacked on the glass substrate of a liquid crystal cell, for example, the optical laminated body of this invention is provided. Since the pressure-sensitive adhesive layer absorbs and relaxes the stress caused by the dimensional change of the optical film and the glass substrate under moist heat conditions, such an optical laminate reduces local stress concentration and lifts and peels off the pressure-sensitive adhesive layer on the glass substrate. This is suppressed. Moreover, since optical defects resulting from nonuniform stress distribution are prevented, when a glass substrate is a TN liquid crystal cell (TFT), whitening is suppressed.

In addition, even after peeling the film from the optical laminated body in order to reattach the optical film with pressure-sensitive adhesive, so-called rework in which the surface of the glass base material that is in contact with the pressure-sensitive adhesive layer hardly generates a blur or an adhesive. Excellent in sex Thereby, even if peeling the optical film with an adhesive which once laminated | stacked from the glass substrate of an optical laminated body, the remainder of an adhesive agent and cloudiness are suppressed on the surface of the glass substrate after peeling, and can be used as a glass substrate again.

Claims (15)

 In the pressure-sensitive adhesive formed by crosslinking the acrylic resins (1) and (2) with a crosslinking agent, the weight percentage X (%) of the tetrahydrofuran insoluble content with respect to the pressure-sensitive adhesive and the tetrahydrofuran insoluble content of the pressure-sensitive adhesive represented by formula (III) The adhesive which the weight percentage Y (%) of the high molecular weight component in satisfy | fills Formula (I) and (II).        40 ≤ X ≤ 70 (I) -0.51X + 41 <Y <0.45X + 24 (II)              Y = B- (100-X) × C / 100 (III) (In formula, X shows the weight percentage (%) of the tetrahydrofuran insoluble content with respect to an adhesive, B represents the weight percentage of the component of 300,000 or more of molecular weight in the mixture of acrylic resin (1) and (2), C represents the weight percentage of the component of 300,000 or more of molecular weight in the tetrahydrofuran melt of an adhesive.) Acrylic resin (1): Acrylic resin whose weight average molecular weight which has a structural unit (structural unit (a)) derived from the following monomer (a) as a main component is 50,000-250,000. (a): (meth) acrylic acid ester represented by Formula (A)

(In formula, R <_1> represents a hydrogen atom or a methyl group, R <_2> represents a C1-C14 alkyl group or an aralkyl group. The hydrogen atom of the alkyl group of R <_2> or the aralkyl group is a C1-C10 alkoxy group. May be substituted.) Acrylic resin (2): The acrylic resin containing a structural unit (a structural unit (b)) which has a structural unit (a) as a main component and originates in the following monomer (b), The weight average molecular weight of this resin is 1,000,000-1,500,000. Acrylic resin. (b): A monomer containing at least one polar functional group selected from the group consisting of a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, an oxetanyl group, an aldehyde group and an isocyanate group and one olefinic double bond in the molecule. The method of claim 1, The adhesive which contains a structural unit (b) further in acrylic resin (1). The method of claim 2, The pressure-sensitive adhesive whose structural unit (b) contained in the acrylic resin (1) is a monomer containing at least one hydroxyl group and one olefinic double bond in a molecule. The method of claim 1, The adhesive whose crosslinking agent is an isocyanate type crosslinking agent. The method of claim 4, wherein The crosslinking agent is at least one kind of crosslinking agent selected from the group consisting of tolylene diisocyanate, adduct obtained by reacting tolylene diisocyanate with a polyol, dimerization of tolylene diisocyanate, and trimerization of tolylene diisocyanate Pressure-sensitive adhesive, characterized in that. The method according to any one of claims 1 to 5, Furthermore, the adhesive containing a silane compound. The optical film with an adhesive formed by laminating | stacking the adhesive of Claim 1 on both surfaces or single side | surface of an optical film. The method of claim 7, wherein The optical film with an adhesive whose optical film is a polarizing film and / or retardation film. The method according to claim 7 or 8, The optical film with an adhesive whose optical film is an optical film formed by further attaching an acetyl cellulose type film as a protective film. The method according to any one of claims 7 to 8, The optical film with an adhesive formed by laminating | stacking a peeling film further on the adhesive layer of an optical film with an adhesive. The optical laminated body formed by laminating | stacking a glass base material on the adhesive layer of the optical film with an adhesive as described in any one of Claims 7-8. The optical laminated body formed by laminating | stacking a glass base material on the adhesive layer obtained by peeling after peeling a peeling film from the optical film with an adhesive of Claim 11. The optical laminated body which laminates the optical film with an adhesive again on the glass base material obtained by peeling after peeling the optical film with an adhesive from the optical laminated body of Claim 11. The optical laminated body which laminates the optical film with an adhesive again on the glass base material obtained by peeling after peeling the optical film with an adhesive from the optical laminated body of Claim 12. 0.8-5 weight part of crosslinking agent is mixed with respect to a total of 100 weight part (non-volatile content) of acrylic resin (1) and (2), The manufacturing method of the adhesive which satisfy | fills Formula (I) and (II) .

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