JP4370888B2 - Optical film with adhesive and optical laminate using the same - Google Patents

Description

The present invention relates to an optical film pressure-sensitive adhesive of the pressure-sensitive adhesive provided on the optical film containing the acrylic resin composition, and an optical laminate stuck to the glass substrate and the adhesive optical film with adhesive.

  The liquid crystal cell has a structure in which a liquid crystal component is sandwiched between two glass substrates, and a polarizing film, a retardation film, etc. are provided on the surface of the glass substrate via an adhesive mainly composed of an acrylic resin. These optical films are laminated to give an optical laminate used for a liquid crystal display device such as TFT and STN. As a method for producing an optical laminate, generally, a method of first laminating an adhesive on an optical film to obtain an optical film with an adhesive, and then laminating a glass substrate on the surface of the adhesive is generally used.

  Such an optical film with pressure-sensitive adhesive tends to curl due to large dimensional change due to expansion and contraction under heat or wet heat conditions, and foams in the pressure-sensitive adhesive layer of the obtained optical laminate, or the pressure-sensitive adhesive layer and the glass substrate. There was a problem that floating and the like occurred. Furthermore, the distribution of residual stress acting on the optical film with adhesive is not uniform under heat or wet heat conditions, resulting in stress concentration at the outer periphery of the optical laminate, resulting in display unevenness such as white spots and color unevenness. There was a problem.

  In order to solve such a problem, it has been proposed to use, as an adhesive, a resin composition comprising an acrylic resin having a polystyrene-equivalent weight average molecular weight of 600,000 to 2,000,000 and an acrylic resin having the same weight average molecular weight of 500,000 or less. Specifically, an adhesive containing an acrylic resin composition of butyl acrylate / acrylic acid copolymer (same weight average molecular weight 1,500,000) and butyl acrylate / hydroxyethyl acrylate copolymer (same weight average molecular weight 100,000) is used. The use is disclosed (Patent Document 1).

JP 2000-109771 A ([Claims] and Example 1)

When the present inventors examined the said adhesive, it became clear that the peeling between the adhesive layer and glass substrate in an optical laminated body may not fully be suppressed.
The purpose of the present invention is to relieve stress concentration caused by expansion and contraction of the optical film, suppress white spots and color unevenness of the optical laminate, and float off between the optical film and the adhesive layer in the optical laminate. and can suppress foaming in the adhesive layer, a acrylic resin composition containing provide a pressure-sensitive adhesive and the optical film pressure-sensitive adhesive consisting of an optical film further adhesive layer of the optical film pressure-sensitive adhesive the invention is to provide an optical laminate formed by laminating a glass substrate optical film through.

  As a result of intensive studies to solve such problems, the present inventors have found that a specific acrylic resin composition is suitable as a pressure-sensitive adhesive, and an optical laminate for reattaching an optical film with a pressure-sensitive adhesive. Thus, even after the film was peeled off, it was found that almost no fogging or adhesive residue was generated on the surface of the glass substrate in contact with the pressure-sensitive adhesive layer, that is, the reworkability was excellent, and the present invention was completed.

Sunawa Chi invention is an optical film pressure-sensitive adhesive comprising a pressure sensitive adhesive and an optical film, the adhesive is made of blended a crosslinking agent and an acrylic resin composition and / or the silane compound The acrylic resin composition contains the following acrylic resins (1) and (2), and the content of the following acrylic resin (1) is 100 parts by weight in total of the following acrylic resins (1) and (2). On the other hand, it is 40 to 95 parts by weight, and the content of the following acrylic resin (2) is 5 to 60 parts by weight with respect to a total of 100 parts by weight of the following acrylic resins (1) and (2) . optical film, and is intended to provide an optical laminate comprising the optical film and the glass substrate with the PSA.

Acrylic resin (1): structural unit derived from the following (a) (structural unit (a)) , structural unit derived from the following (b) (structural unit (b)) and structural unit derived from the following (c) ( Acrylic resin containing structural unit (c)) .

Acrylic resin (2): containing structural units (a) and (c), not containing structural unit (b), the content of structural unit (a) being 100 parts by weight of acrylic resin (2) 65 to 99.95 parts by weight of a linear acrylic resin.

（式中、Ｒ₁は水素原子またはメチル基を表し、Ｒ₂は炭素数１〜１４のアルキル基またはアラルキル基を表す。Ｒ₂ のアルキルまたはアラルキル基には炭素数１〜１０のアルコキシ基が結合していてもよい。） (a): (meth) acrylic acid ester represented by the following formula (A)

(Wherein, R ₁ represents a hydrogen atom or a methyl group, R ₂ is an alkyl or aralkyl group .R ₂ represents an alkyl group or an aralkyl group having 1 to 14 carbon atoms alkoxy group having 1 to 10 carbon atoms May be combined.)

(b): a monomer containing at least two olefinic double bonds in the molecule
(c): A monomer containing a carboxyl group or hydroxyl group and one olefinic double bond in the molecule.

Acrylic resin composition containing an acrylic resin as defined in the present invention (1) and the acrylic resin (2) is excellent in flexibility and has excellent adhesion to the optical film. Further, by blending a curing agent with the acrylic resin composition and / or the silane compound as a viscous Chakuzai, the optical film pressure-sensitive adhesive consisting of this and the optical film, for example by bonding to the glass substrate of the liquid crystal cell when the optical laminate, wet heat conditions, because the stress sensitive adhesive layer due to dimensional changes of the optical film is absorbed and relaxed, is reduced local stress concentration,浮剥of the adhesive layer to the glass substrate This is suppressed. Further, since optical defects due to non-uniform stress distribution are prevented, display unevenness such as white spots and color unevenness is suppressed. Furthermore, because of its excellent reworkability, even if the optical film with adhesive once laminated is peeled off from the glass substrate of the optical laminate, adhesive residue and fogging are suppressed on the surface of the glass substrate after peeling, and again the glass substrate Can be used as
In particular, the above acrylic resin composition, an adhesive obtained by blending a example an isocyanate compound and an organic amine compound crosslinking agent may be prepared optical film pressure-sensitive adhesive in a short time of ripening, the adhesive optical laminate urging optical film was bonded to a glass substrate,浮剥Re and between the glass substrate and the adhesive layer, is suppressed foaming in the adhesive layer, moreover excellent reworkability.

（式中、Ｒ₁は水素原子またはメチル基を表し、Ｒ₂は炭素数１〜１４のアルキル基またはアラルキル基を表す。Ｒ₂ のアルキル基、アラルキル基には炭素数１〜１０のアルコキシ基が結合していてもよい。） Hereinafter, the present invention will be described in detail.
In the present invention , the monomer (a) used in the acrylic resins (1) and (2) is a (meth) acrylic acid ester represented by the formula (A) .

(In the formula, R ₁ represents a hydrogen atom or a methyl group, and R ₂ represents an alkyl group or an aralkyl group having 1 to 14 carbon atoms. The alkyl group or the aralkyl group represented by R ₂ has an alkoxy group having 1 to 10 carbon atoms. May be bonded.)

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, iso-octyl acrylate, lauryl acrylate Acrylates such as stearyl acrylate, cyclohexyl 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, lauryl methacrylate, stearyl methacrylate , It may be mentioned cyclohexyl methacrylate, benzyl methacrylate, methacrylic acid esters such as methoxyethyl methacrylate and ethoxyethyl methacrylate and the like. As the monomer (a), it may be used two different than above.

In A acrylic resin (1), the content of the structural unit derived from the monomer (a) (structural unit (a)), the acrylic resin (1) with respect to 100 parts by weight, usually 65 to 99.85 weight Part, preferably about 70 to 95 parts by weight.
Moreover, content of the structural unit (structural unit (a)) derived from the monomer (a) in the acrylic resin (2) is 65 to 99.95 parts by weight with respect to 100 parts by weight of the acrylic resin (2). It is.

The monomer (b) used in the A acrylic resin (1), a monomer containing at least two olefinic double bonds in the molecule. Due to the presence of the monomer (b), the main chain composed of the structural unit (a) of the acrylic resin (1) is crosslinked.
Specific examples of the monomer (b) include a monomer (bifunctional monomer) containing two olefinic double bonds in the molecule, 1,4-butanediol di (meth) acrylate, 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 Monomers having two (meth) acryloyl groups in the molecule such as di (meth) acrylate, bis (meth) acrylamides such as methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide, divinyl adipate, divinyl sebacate Divinyl esters such as allyl methacrylate Rate, divinylbenzene and the like. Moreover, as a monomer (trifunctional monomer) containing three olefinic double bonds in the molecule, 1,3,5-triacryloylhexahydro-s-triazine, triallyl isocyanurate, triallylamine, N, N-diallylacrylamide etc. are mentioned, As a monomer (tetrafunctional monomer) which contains four olefinic double bonds in a molecule | numerator, tetramethylol methane tetraacrylate, tetraallyl pyromellitate, N, N, N ′, N′-tetraallyl-1,4-diaminobutane, tetraallylammonium salt and the like can be mentioned. As the monomer (b), it may be used two different than above.

（式中、Ｒ₃は水素原子またはメチル基を表す。） Among the monomers (b), bifunctional monomers are preferable, and monomers having two ( meth) acryloyl groups in the molecule as represented by the following formula (B) are particularly preferable.

(In the formula , R ₃ represents a hydrogen atom or a methyl group.)

The content ([b-1] ) of the structural unit derived from the monomer (b) in the acrylic resin (1) is usually 0.05 to 5 parts by weight with respect to 100 parts by weight of the acrylic resin (1). The amount is preferably about 0.1 to 3 parts by weight. When [b-1] is 0.05 parts by weight or more, the effect of improving white spots occurring during the production of the optical laminate tends to be improved, and when it is 5 parts by weight or less, acrylic is preferred. This is preferable because the formation of gel during the production of the resin tends to be suppressed.

The acrylic resin (2) used in the present invention is a linear acrylic resin having the structural unit (a) as a main component, in other words, an acrylic resin that substantially does not contain the structural unit (b). When substantially describing an acrylic resin containing no structural units (b) specifically contains a structural unit (a) as an essential component, the amount of structural units (b), contained in the acrylic resin (1) those are the content of the structural units (b) of less than one fifth of the weight. That is, the content of the structural unit (b) in the acrylic resin (2) ([b-2]) and the content of the structural unit (b) in the acrylic resin (1) used simultaneously as the acrylic resin composition ([b -1]) means that it is represented by the following formula.
[B-2] / [b-1] ≦ 1/5

In particular, the content of the structural unit (b) in the acrylic resin (2) is preferably 0.02 parts by weight or less, more preferably 0.01 parts by weight or less with respect to 100 parts by weight of the acrylic resin (2). By the acrylic resin (2) is a linear acrylic resin, preferred since it tends to Re lifting peeling between the adhesive layer and the glass substrate containing A acrylic resin composition can be suppressed.

Each acrylic resin (1) and the acrylic resin (2) it is used in the present invention, a polar functional group selected from carboxyl group and a hydroxyl group, a monomer containing a single olefinic double bond and the intramolecular ( structural units derived from c) you containing (structural unit (c)). Polar functional group of the structural unit (c) is, you crosslinked with later crosslinking agent.

As specific examples of the monomer (c), examples of the monomer (c) whose polar functional group is a carboxyl group include acrylic acid, methacrylic acid, maleic acid, itaconic acid, and the like. Examples of the monomer (c) that is a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, and the like . And these monomers (c), may be used in combination on different two or more kinds.

The content of the structural unit (c) contained in the acrylic resin (2) is usually about 0.05 to 20 parts by weight, preferably 0.1 to 15 parts per 100 parts by weight of the acrylic resin (2). About parts by weight. When the content of the structural unit (c) is 0.05 parts by weight or more, the cohesive force of the obtained resin tends to be improved, and when it is 20 parts by weight or less , the optical film and the pressure-sensitive adhesive layer It is preferable because there is a tendency that the floating peeling between the two is suppressed.
The content of the structural unit (c) contained in the acrylic resin (1) is usually 20 parts by weight or less with respect to 100 parts by weight of the acrylic resin (1). When the content of the structural unit (c) is less than 20 parts by weight, Re floating peeling between the glass substrate and the adhesive layer is preferred since it tends to be suppressed.

  When the acrylic resins (1) and (2) used in the present invention are produced, they may be polymerized together with a vinyl monomer (d) different from any of the monomers (a) to (c). Examples of the vinyl monomer include fatty acid vinyl esters, vinyl halides, vinylidene halides, aromatic vinyls, (meth) acrylonitrile, conjugated diene compounds, and the like.

Examples of the fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate acid, vinyl 2-ethylhexanoate, and vinyl laurate.
Examples of the vinyl halide include vinyl chloride and vinyl bromide, examples of the vinylidene halide include vinylidene chloride and the like, and examples of the (meth) acrylonitrile include acrylonitrile and methacrylonitrile.
The conjugated diene compound is an olefin having a conjugated double bond in the molecule, and specific examples include isoprene, butadiene and chloroprene.
Aromatic vinyl is a compound having a vinyl group and an aromatic group. Specific examples include styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexyl. Styrene monomers such as styrene, heptylstyrene, octylstyrene, fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene, nitrostyrene, acetylstyrene and methoxystyrene, and nitrogen-containing aromatics such as vinylpyridine and vinylcarbazole Vinyl etc. are mentioned. And these vinyl monomers and (d), may be used in combination on different two or more kinds.

The structural unit (d) derived from the monomer (d) contained in the acrylic resin (1) is usually 5 parts by weight or less with respect to 100 parts by weight of all the structural units constituting the acrylic resin (1). The amount is preferably 0.05 parts by weight or less , but more preferably substantially not contained.
The structural unit (d) contained in the acrylic resin (2) is usually 5 parts by weight or less, preferably 0.05 parts by weight or less with respect to 100 parts by weight of all structural units constituting the acrylic resin (2). Although it is , it is more preferable not to contain substantially.

Examples of the method for producing the acrylic resins (1) and (2) used in the present invention include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a suspension polymerization method. In the production of acrylic resin, a polymerization initiator is usually used. The polymerization initiator is used in an amount of about 0.001 to 5 parts by weight with respect to a total of 100 parts by weight of all monomers used in the production of the acrylic resin.

Examples of the polymerization initiator include thermal polymerization initiators and photopolymerization initiators, and examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone. Can be mentioned. Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile). 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2′-azobis (2-methylpro) Azo compounds such as pioneate) and 2,2′-azobis (2-hydroxymethylpropionitrile); lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroper Oxide, diisopropyl peroxydicarbonate, di-n-propyl peroxydicarbonate, tert-butyl peroxyneo Decanoate, tert- butyl peroxypivalate, organic peroxides, such as (3,5,5-trimethyl hexanoyl) peroxide; potassium persulfate, ammonium persulfate, inorganic peroxides such as hydrogen peroxide and the like. A redox initiator using a thermal polymerization initiator and a reducing agent in combination can also be used as the polymerization initiator.

As a method for producing the acrylic resins (1) and (2), a solution polymerization method is particularly preferable. Specific examples of the solution polymerization method include monomers (a) to (c), and if necessary, the monomer (d) and an organic solvent are mixed, and a polymerization initiator is added under a nitrogen atmosphere. A method of adding and stirring at about 40 to 90 ° C., preferably about 60 to 80 ° C. for about 3 to 10 hours can be mentioned. In order to control the reaction, the monomer or polymerization initiator to be used may be added during the polymerization or after being dissolved in an organic solvent.
Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as n-propyl alcohol and isopropyl alcohol; methyl ethyl ketone and methyl isobutyl ketone. And ketones.

The acrylic resin (1) thus obtained has a viscosity (25 ° C.) of a solution obtained by diluting it with ethyl acetate to a solid content of 30% by weight, usually 10 Pa · s or less, preferably 5 Pa · s or less. is there. When the viscosity is 10 Pa · s or less, even if the dimension of the optical film changes, the pressure-sensitive adhesive layer fluctuates following the change in dimension, so the brightness of the periphery of the liquid crystal cell and the brightness of the center This is preferable because there is no difference between them and display unevenness such as white spots and color unevenness tends to be suppressed. The molecular weight of the acrylic resin (1) is usually 5 × 10 ⁵ or more, preferably 1 × 10 ⁶ or more, as determined by gel permeation chromatography (GPC) light scattering method. When the weight average molecular weight is 5 × 10 ⁵ or more, the adhesiveness under high temperature and high humidity is improved, and there is a tendency that the peeling between the glass substrate and the pressure-sensitive adhesive layer is lowered, and the reworkability is improved. It is preferable because of the tendency.

As the molecular weight of the acrylic resin (2), the weight average molecular weight determined by the light scattering method of gel permeation chromatography (GPC) is usually 1 × 10 ⁶ or more, preferably 2 × 10 ⁶ to 1 × 10 ^7. It is. When the weight average molecular weight is 1 × 10 ⁶ or more, the adhesiveness under high temperature and high humidity is improved, and the peeling between the glass substrate and the pressure-sensitive adhesive layer tends to decrease, and the reworkability is improved. It is preferable because of its tendency. When the weight average molecular weight is 1 × 10 ⁷ or less, even if the dimension of the optical film changes, the pressure-sensitive adhesive layer fluctuates following the change in dimension, so the brightness of the peripheral edge and the brightness of the center of the liquid crystal cell This is preferable because there is no difference between the two and display unevenness such as white spots and color unevenness tends to be suppressed.

The acrylic resin composition used in the present invention is a resin composition containing the acrylic resin (1) and the acrylic resin (2) thus obtained, and the production method thereof is usually an acrylic resin (1) and an acrylic resin. (2) is manufactured separately and then mixed, but after manufacturing either acrylic resin (1) or acrylic resin (2), different acrylic resins may be manufactured in the presence of the manufactured acrylic resin. Moreover, after mixing acrylic resin (1) and (2), you may dilute with an organic solvent.

The weight ratio (solid content ) between the acrylic resin (1) and the acrylic resin (2) in the acrylic resin composition is 100 parts by weight of the acrylic resin (1) and the acrylic resin (2). There usually 5 parts by weight or more, preferably about 10 to 60 parts by weight. If the acrylic resin (2) is 5 parts by weight or more, even if the dimension of the optical film changes, the pressure-sensitive adhesive layer fluctuates following the change in dimension, so the brightness of the peripheral part of the liquid crystal cell and the central part This is preferable because there is no difference in brightness and display unevenness such as white spots and color unevenness tends to be suppressed.

The viscosity of a solution (25 ° C.) prepared by adjusting the acrylic resin composition to 30 wt % solid content with ethyl acetate is preferably 10 Pa · s or less, more preferably 1 to 5 Pa · s. When the viscosity is 10 Pa · s or less, the adhesiveness under high temperature and high humidity is improved, the peeling between the glass substrate and the pressure-sensitive adhesive layer tends to decrease, and the reworkability tends to be improved. This is preferable.

Acrylic resin composition containing an acrylic resin (1) and the acrylic resin (2) is further blended a crosslinking agent and / or the silane compound, Ru is an adhesive. Here, the cross-linking agent has two or more functional groups capable of cross-linking with polar functional groups in the molecule, specifically, isocyanate compounds, epoxy compounds, metal chelate compounds , aziridine compounds, etc. Is exemplified.

Here, the isocyanate compound includes, for example, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, Examples thereof include phenylmethane triisocyanate and polymethylene polyphenyl isocyanate. Further, the isocyanate compound, glycerol, adducts and obtained by reacting an a polyol Le of trimethylolpropane, which was an isocyanate compound 2,3-mers etc. is also Ru cormorants become crosslinking agent.

Examples of the epoxy compound include bisphenol A type epoxy resin, ethylene glycol glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylol propane tri Examples thereof include glycidyl ether, diglycidyl aniline, N, N, N ′, N′-tetraglycidyl-m-xylenediamine , and 1,3-bis (N, N′-diglycidylaminomethyl) cyclohexane.

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

Examples of the aziridine compound include N, N′-diphenylmethane-4,4′-bis (1-aziridinecarboxide), N, N′-toluene-2,4-bis (1-aziridinecarboxamide), triethylenemelamine Bisisophthaloyl-1- (2-methylaziridine), tri-1-aziridinylphosphine oxide, N, N′-hexamethylene-1,6-bis (1-aziridinecarboxide), trimethylolpropane Examples include tri-β-aziridinyl propionate and tetramethylolmethane-tri-β-aziridinyl propionate.

Oite the viscosity Chakuzai may use two or more crosslinking agents. The use amount (solid content) of the crosslinking agent in the pressure-sensitive adhesive is usually about 0.005 to 5 parts by weight, preferably about 0.01 to 3 parts by weight with respect to 100 parts by weight (solid content) of the acrylic resin. It is. When the amount of the cross-linking agent is 0.005 weight or more, it is preferable because floating and reworkability between the optical film and the pressure-sensitive adhesive layer tend to be improved, and when it is 5 parts by weight or less, the optical film. Since the followability of the pressure-sensitive adhesive layer is excellent with respect to the dimensional change, display unevenness such as white spots and color unevenness tends to decrease, which is preferable.

  When only an isocyanate compound is blended as the cross-linking agent, when only an epoxy compound is blended, the optical laminate provided by the resulting pressure-sensitive adhesive is preferred because it tends to be excellent in exfoliation and reworkability.

As the silane compound used in the viscous adhesive, if example embodiment, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2- aminoethyl) -3-aminopropyl methyl dimethoxy silane N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and the like. Visco Chakuzai may use two or more kinds of silane-based compounds.

The usage- amount of the silane type compound in an adhesive is about 0.0001-10 weight part normally with respect to a total of 100 weight part (solid content) of acrylic resin (1) and (2), Preferably 0.01- 5 parts by weight of der Ru. When the amount of the silane compound is 0.0001 part by weight or more , the adhesiveness between the pressure-sensitive adhesive layer and the glass substrate is improved. If the amount of the silane compound is 10 parts by weight or less, the silane compound is prevented from bleeding out from the adhesive layer, since it tends to suppress the cohesive failure of the adhesive layer, preferred. Adhesive preferably contains both a crosslinking agent and a silane compound.

Viscosity Chakuzai an acrylic resin composition as described above are those obtained by blending a crosslinking agent and / or the silane compound, also contain organic solvents used prior to production of the acrylic resin composition Good. Furthermore, crosslinking catalysts, weathering stabilizer, tackifier, plasticizer, softener, dye, pigment, a non-machine filler or the like may be blended in the adhesive.

  Among them, when a crosslinking catalyst and a crosslinking agent are blended in the pressure-sensitive adhesive, an optical film with a pressure-sensitive adhesive can be prepared by aging in a short time, and the optical laminate including the film is between the optical film and the pressure-sensitive adhesive layer. It is preferable because it prevents floating and foaming in the pressure-sensitive adhesive layer and is excellent in reworkability. Examples of the crosslinking catalyst include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, triethylenediamine, polyamino resin, and melamine resin. When an amine compound is used as a crosslinking catalyst for the pressure-sensitive adhesive, an isocyanate compound is suitable as the crosslinking agent.

Adhesive attached optical film arm of the present invention are those consisting of the adhesive and the optical film, as its production method, for example, an adhesive is applied which is diluted in an organic solvent on a release film, 60 The organic solvent is distilled off by heating at ~ 120 ° C for about 0.5 to 10 minutes to obtain a pressure-sensitive adhesive layer. Next, after pasting the optical film on the pressure-sensitive adhesive layer, if the atmosphere is at a temperature of 23 ° C. and humidity of 50%, it is aged for 5 to 20 days, and after the crosslinking agent has sufficiently reacted, the release film is peeled off. Method for obtaining an optical film with an adhesive; after obtaining an adhesive layer in the same manner as described above, the release film and the adhesive layer are alternately laminated on the obtained laminate of the release film and the adhesive layer. After being combined in multiple layers, if the atmosphere is at 23 ° C. and 50% humidity, it is aged for about 5 to 20 days, and after the crosslinking agent has reacted sufficiently, the release film is peeled off, and an optical film is pasted instead. And a method for obtaining an optical film with a pressure-sensitive adhesive.
Here, a peeling film is a base material at the time of forming an adhesive layer. In some cases, it is a base material that protects the pressure-sensitive adhesive layer from foreign matters such as dust and dust during aging and storage as an optical film with pressure-sensitive adhesive. As a specific example of the release film, a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate is used as a base material, and a release treatment (silicone treatment) is performed on the bonding surface with the adhesive layer of the base material. Etc.).

  The optical film used for the optical film with pressure-sensitive adhesive of the present invention is a film having optical properties, and examples thereof include a polarizing film and a retardation film. A polarizing film is an optical film having a function of emitting polarized light with respect to incident light such as natural light. As a polarizing film, a linearly polarizing film having a property of absorbing linearly polarized light having a vibrating surface parallel to the optical axis and transmitting linearly polarized light having a vibrating surface that is a vertical surface, parallel to the optical axis. Examples thereof include a polarizing separation film that reflects linearly polarized light on the vibration surface, and an elliptically polarizing film in which a polarizing film and a retardation film described later are laminated. Specific examples of the polarizing film include a film in which a dichroic dye such as iodine or a dichroic dye is adsorbed and oriented on a uniaxially stretched polyvinyl alcohol film.

  The retardation film is an optical film having optical anisotropy such as uniaxial or biaxial, for example, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polystyrene, polysulfone, polyethersulfone, polysulfone, By stretching a polymer film made of vinylidene fluoride / polymethyl methacrylate, liquid crystal polyester, acetyl cellulose, cyclic polyolefin, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride, etc. by about 1.0 to 6 times. The stretched film obtained is mentioned. Among these, a polymer film obtained by uniaxially or biaxially stretching polycarbonate or polyvinyl alcohol is preferable.

  As the retardation film, uniaxial retardation film, wide viewing angle retardation film, low photoelasticity retardation film, temperature compensation retardation film, LC film (rod-like liquid crystal twist orientation), WV film (disc-like liquid crystal tilt) Orientation), NH film (rod-like liquid crystal tilted orientation), VAC film (fully biaxially oriented retardation film), newVAC film (biaxially oriented retardation film), and the like.

Furthermore, what has bonded the board | substrate film (Protective Film) to the single side | surface or both surfaces of these optical films is used suitably as an optical film. As the substrate film, for example, an acrylic resin film different from the acrylic resin defined in the present invention , an acetyl cellulose film such as a cellulose triacetate film, a polyester resin film, an olefin resin film, a polycarbonate resin film, a polyether ether ketone resin film And a polysulfone resin film. The substrate film may contain an ultraviolet absorber such as a salicylic acid ester compound, a benzophenone compound, a benzotriazole compound, a triazine compound, a cyanoacrylate compound, or a nickel complex compound. Among the substrate films, acetylcellulose-based films are preferable.

The optical layered body of the present invention comprises an optical film with an adhesive and a glass substrate. Optical stack can usually be prepared by pasting a glass substrate pressure-sensitive adhesive layer of the optical film pressure-sensitive adhesive. Here, as a glass substrate, the glass substrate of a liquid crystal cell, the glass for glare-proof, the glass for sunglasses etc. are mentioned, for example. Among them, an adhesive layer of an optical film with an adhesive (upper polarizing plate) is bonded to the glass substrate at the upper part of the liquid crystal cell, and another optical film with adhesive (lower polarizing plate) on the glass substrate at the lower part of the liquid crystal cell. ) Is preferably used because it can be used as a liquid crystal display device. Examples of the material for the glass substrate include soda lime glass, low alkali glass, and non-alkali glass.

The optical layered body of the present invention is peeled off from the surface of the glass substrate that has been in contact with the pressure-sensitive adhesive layer even after the optical film with the pressure-sensitive adhesive is peeled off from the optical layered body. glass substrate again, cut with easily implementation it back bonding the optical film pressure-sensitive adhesive, i.e., it is excellent in reworking property.

Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, “parts” and “%” are based on weight unless otherwise specified. The solid content was measured by a method according to JIS K-5407. Specifically, the table at a rate vs. any weight adhesive solution, taken up in a petri dish and the residual solid weight after drying 2 hours at 115 ° C. at explosion-proof oven, the weight of the first to the weighed solution It is a thing. The viscosity is a value measured with a Brookfield viscometer at 25 ° C. The weight average molecular weight measurement by GPC light scattering method uses a GPC apparatus equipped with a light scattering photometer and a differential refractometer as a detector, sample concentration 5 mg / ml, sample introduction amount 100 μml, column temperature 40 ° C., flow rate 1 ml / in conditions min, and it carried out using tetrahydrofuran as eluent. The weight average molecular weight by terms of polystyrene, the sample and standard polystyrene were measured under the conditions of the same GPC, it was determined by converting the molecular weight from retention volume.

<Examples of acrylic resin production>
(Polymerization example 1)
A reactor equipped with a cooling pipe, a nitrogen introducing pipe, a thermometer, and a stirrer was charged with 233 parts of ethyl acetate, the air in the apparatus was replaced with nitrogen gas, and the internal temperature was reduced to 70 ° C. The temperature rose. After adding 0.5 part of azobisisobutyronitrile (hereinafter sometimes referred to as AIBN) which is a polymerization initiator, acrylic acid is used as monomer (a) while maintaining the internal temperature at 65 to 75 ° C. 95 parts of butyl, 1 part of ethylene glycol diacrylate (hereinafter sometimes referred to as EGDA) as the monomer (b) and 4-hydroxybutyl acrylate (hereinafter referred to as 4HBA) as the monomer (c) 4 parts of the mixed solution was dropped into the reaction system over 3 hours. Thereafter, the mixture was kept at 65 to 75 ° C. for 5 hours to complete the reaction. When the solid content concentration of the obtained acrylic resin solution was adjusted to 30.0%, the viscosity was 263 mPa · s. The weight average molecular weight by GPC light scattering method was about 2,300,000, and the weight average molecular weight in terms of polystyrene was 553,000.

(Polymerization example 2)
Except the amount of the amount and the polymerization initiator of the monomer (b) to change as described in Table 1 was prepared an acrylic resin in the same manner as in Polymerization Example 1. Table 1 shows the viscosity of the obtained resin solution and the measurement results of the light scattering method and the weight average molecular weight in terms of polystyrene .

(Polymerization Examples 3 and 4)
Used amounts described monomer of (a) in Table 1, the monomer (b) tripropylene glycol diacrylate used amounts given (hereinafter may be serial TPGDA and table.) In Table 1, the single mer of acrylic acid using amounts shown in Table 1 as (c), further the amount of the polymerization initiator other than to change as described in Table 1 in the same manner as in polymerization example 1 to produce an acrylic resin. Table 1 shows the viscosity of the obtained resin solution and the measurement results of the light scattering method and the weight average molecular weight in terms of polystyrene .

(Polymerization Example 5 : for comparison )
An acrylic resin was produced in the same manner as in Polymerization Example 1 except that the monomer (b) was not used and the amount of the polymerization initiator was changed as shown in Table 1 . Table 1 shows the viscosity of the obtained resin solution and the measurement results of the light scattering method and the weight average molecular weight in terms of polystyrene .

(Polymerization Example 6)
The same reactor as in Polymerization Example 1, 95 parts butyl acrylate as a monomer (a), 4 parts of 4HBA as a monomer (c), and 233 parts of ethyl acetate narrowing specification, the apparatus with nitrogen gas The air was replaced with oxygen free, and the internal temperature was raised to 70 ° C. After 0.05 parts of added pressure to the AIBN, was incubated at 50 ° C. 10 hours to complete the reaction. The reaction product obtained was precipitated purified by methanol solvent, the solvent was distilled off, dissolved again with ethyl acetate, the concentration of solids to obtain an ethyl acetate solution of acrylic resin is 15%. The measurement results of the viscosity and weight average molecular weight of the obtained resin solution are shown together in Table 1.

(Polymerization Example 7)
In Polymerization Example 6 , the reaction was carried out in the same manner except that the reaction temperature was 60 ° C., and an ethyl acetate solution of an acrylic resin having a solid content concentration of 20.1% was obtained. The measurement results of the viscosity and weight average molecular weight of the obtained resin solution are shown together in Table 1.

(Polymerization Example 8)
In a reaction vessel similar to Polymerization Example 1, 96 parts of ethyl acetate, 99 parts of butyl acrylate as monomer (a) and 1 part of acrylic acid as monomer (c) were charged, and the air in the apparatus was purged with nitrogen gas. After substitution and oxygen free, the internal temperature was raised to 55 ° C. 2,2′-azobis (2,4-dimethylvaleronitrile), a polymerization initiator, was added in a total amount of 0.05 part in 4 parts of ethyl acetate, and then the internal temperature was maintained at 54 to 56 ° C. Keep warm for hours. At this time, the concentration of ethyl acetate was 50%. Then, as the concentration of ethyl acetate is increased One not a 5% ethyl acetate was added every 3 hours, ethyl acetate concentration is kept further 3 hours from the time that was 85%, carrying out the reaction, solid concentration An ethyl acetate solution of an acrylic resin having a content of 15.4% was obtained. The measurement results of the viscosity and weight average molecular weight of the obtained resin solution are shown together in Table 1.

< Example of production of acrylic resin composition and pressure-sensitive adhesive containing the composition >
(Examples of production of pressure-sensitive adhesives used in Examples 1 to 5 and Comparative Examples 1 to 4)
Of the acrylic resin solution obtained in Polymerization Example (1) and (2), the weight of each solid content was prepared in ethyl acetate solution of an acrylic resin composition was mixed in a ratio as in Table 2 . The solid content 100 parts contained in the ethyl acetate solution, isocyanate compound is a crosslinking agent (trade name: Coronate L, manufactured by Nippon Polyurethane Co.) 0.1 parts of (solid) is the silane compound γ- glycidoxypropyltrimethoxysilane was mixed with propyl trimethoxysilane down 0.2 parts to obtain a pressure-sensitive adhesive.

(Examples of production of pressure-sensitive adhesives used in Examples 6 to 9 and Comparative Example 5 )
Polymerization Example obtained in the acrylic resin solution (1) and (2), the weight of each solid content was prepared ethyl acetate solution of mixed and an acrylic resin composition such that the ratio as in Table 3 . The solid content 100 parts contained in the ethyl acetate solution, isocyanate compound is a crosslinking agent (trade name: Coronate L, manufactured by Nippon Polyurethane Co.) 0.1 parts of (solid) is the silane compound 0.2 parts of γ-glycidoxypropyltrimethoxysilane and triethylenediamine as an amine compound were mixed in the amounts shown in Table 3 to obtain a pressure-sensitive adhesive.

<Production Example 1 of optical film with adhesive and optical laminate>
(Aging for 14 days: Examples 1 to 5 and Comparative Examples 1 to 4)
Polyethylene terephthalate film (trade name: manufactured by Lintec Corporation ) obtained by releasing the pressure-sensitive adhesive obtained in the previous (Examples for producing pressure-sensitive adhesives used in Examples 1 to 5 and Comparative Examples 1 to 4) using an applicator. PET3811) was applied to the release-treated surface so that the thickness after drying was 25 μm, and dried at 90 ° C. for 1 minute to obtain a sheet-like pressure-sensitive adhesive. Next, a polarizing film (a film having a three-layer structure in which both sides of a film stretched by adsorbing iodine to polyvinyl alcohol are sandwiched by a triacetyl cellulose-based substrate film) is used as an optical film. The surfaces having the pressure-sensitive adhesive were pasted together with a laminator, and then aged for 14 days under conditions of a temperature of 40 ° C. and a humidity of 50% to obtain an optical film with a pressure-sensitive adhesive provided with a pressure-sensitive adhesive layer. Subsequently, the surfaces of the pressure-sensitive adhesive layer of the optical film with pressure-sensitive adhesive were bonded to both surfaces of a glass substrate for liquid crystal cell (Corning Corp., 1737) so as to be crossed Nicol. When this was stored at 80 ° C. and Dry for 96 hours (Condition 1) and when stored at 60 ° C. and 90% RH for 96 hours (Condition 2), the durability and white spots in the optical laminate after storage were each The expression state of was visually observed. The results were classified in a manner which will be described later, are summarized in Table 2.

<Production Example 2 of optical film with adhesive and optical laminate>
(Aging for 7 days: Examples 6 to 9 and Comparative Example 5)
Except that the aging time of the optical film with the adhesive was set to 7 days using the adhesive obtained in the previous (Examples for producing the adhesive to be used in Examples 6 to 9 and Comparative Example 5) . The optical film and the optical laminate were manufactured in the same manner as in Production Example 1>, and for each of the conditions 1 and 2, the durability and the appearance of white spots in the optical laminate after storage were visually observed. The results were classified in the following manner, it is summarized in Table 3.

<White Leakage of Optical Laminate>
The evaluation of the expression state of white spots was performed in the following four stages.
A: No white spots are observed.
○: White spots are hardly noticeable.
Δ: White spots are slightly noticeable.
X: White spots are noticeable.

<Durability of optical laminate>
The durability was evaluated in the following four stages.
A: No change in appearance such as floating, peeling or foaming is observed.
○: Almost no change in appearance such as floating, peeling or foaming.
Δ: Appearance changes such as floating, peeling and foaming are slightly noticeable.
X: Appearance changes such as floating, peeling and foaming are noticeable.

<Reworkability>
The reworkability was evaluated as follows. First, the optical film with pressure-sensitive adhesive was cut into a 25 mm × 150 mm test piece. Next, this test piece was attached to a glass substrate for liquid crystal cells (Soda Lime Glass, manufactured by Nippon Sheet Glass Co., Ltd.) using an attaching device (“Lami Packer” manufactured by Fuji Plastic Machinery Co., Ltd.), 50 ° C., 5 kg / Autoclaving was performed at cm ² (490.3 kPa) for 20 minutes. Then, have rows 2 hours of heat treatment at 70 ° C., after further 24 hours storage at 70 ° C. in an oven, 23 ° C., the bonded specimens at a relative humidity of 50% RH atmosphere for 300 mm / min Table 2 and Table 3 show the results of peeling in a 180 ° direction at a speed, observing the state of the glass plate surface, and classifying in the following manner .

The state of the surface of the glass plate was evaluated for reworkability the following four stages.
A: No fogging or adhesive residue is observed on the glass plate surface.
○: Almost no fogging or the like is observed on the glass plate surface.
(Triangle | delta): Cloudiness etc. are recognized by the glass plate surface.
X: Adhesive residue is recognized on the glass plate surface.

The optical film with pressure-sensitive adhesive of the present invention and the optical laminate obtained by bonding it to a glass substrate can be suitably used for, for example, a liquid crystal cell.

Claims (7)

An optical film with an adhesive comprising an adhesive and an optical film,
The pressure-sensitive adhesive is a pressure-sensitive adhesive formed by blending an acrylic resin composition and a crosslinking agent and / or a silane compound,
The acrylic resin composition contains the following acrylic resins (1) and (2), and the content of the following acrylic resin (1) is 100 parts by weight in total of the following acrylic resins (1) and (2). The acrylic resin composition is 40 to 95 parts by weight, and the content of the following acrylic resin (2) is 5 to 60 parts by weight with respect to a total of 100 parts by weight of the following acrylic resins (1) and (2). Optical film with adhesive.
Acrylic resin (1): structural unit derived from the following (a) (structural unit (a)), structural unit derived from the following (b) (structural unit (b)) and structural unit derived from the following (c) ( Acrylic resin containing structural unit (c)).
Acrylic resin (2): containing structural units (a) and (c), not containing structural unit (b), the content of structural unit (a) being 100 parts by weight of acrylic resin (2) 65 to 99.95 parts by weight of a linear acrylic resin.
(a): (meth) acrylic acid ester represented by the following formula (A)

(Wherein R ₁ represents a hydrogen atom or a methyl group, R ₂ represents an alkyl group or an aralkyl group having 1 to 14 carbon atoms. The alkyl or aralkyl group represented by R ₂ is an alkoxy group having 1 to 10 carbon atoms. May be substituted.)
(b): a monomer containing at least two olefinic double bonds in the molecule
(c): a monomer containing a carboxyl group or hydroxyl group and one olefinic double bond in the molecule   The optical film with an adhesive according to claim 1, wherein the content of the structural unit (a) in the acrylic resin (1) is 65 to 99.85 parts by weight with respect to 100 parts by weight of the acrylic resin (1). The optical film with pressure-sensitive adhesive according to claim 1 or 2, wherein the monomer (b) is a monomer containing at least two (meth) acryloyl groups represented by the following formula (B) in the molecule.

(In the formula, R ₃ represents a hydrogen atom or a methyl group.)   The optical film with an adhesive according to any one of claims 1 to 3, wherein the adhesive further contains an amine compound as a crosslinking catalyst.   An optical film is a polarizing film and / or a phase difference film, The optical film with an adhesive in any one of Claims 1-4.   The optical film with an adhesive according to any one of claims 1 to 5, wherein a release film is further laminated on the adhesive layer of the optical film with an adhesive.   The optical laminated body which consists of an optical film with an adhesive in any one of Claims 1-5, and a glass substrate.