JP4722781B2 - Adhesive optical film and image display device - Google Patents

Description

  The present invention relates to an adhesive optical film and an image display device, and more particularly to an adhesive optical film and an image display device used as various optical films including an adhesive layer and an undercoat layer.

Conventionally, optical films such as polarizing films, retardation films, brightness enhancement films, and viewing angle widening films have been used in various industrial applications, such as liquid crystal displays, organic electroluminescence devices (organic EL display devices), It is used by being attached to an image display device such as a plasma display panel (PDP).
As an optical film to be attached to a liquid crystal display, an adhesive optical film in which an adhesive is laminated on an optical film is known.

For example, an isocyanate-based polyfunctional compound is added to an acrylic polymer solution to prepare a pressure-sensitive adhesive solution, which is laminated (laminated) on a polarizing film with an undercoat layer (anchor layer) made of a water-dispersible polyester resin. An adhesive optical film has been proposed (see, for example, Patent Document 1).
In recent years, from the viewpoint of environmental impact, it has been desired to reduce the use of organic solvents. From solvent-based adhesives that use organic solvents as solvents, to water-dispersed adhesives that use water as a dispersion medium. Conversion is desired.

As such a water-dispersed pressure-sensitive adhesive, for example, a pressure-sensitive adhesive composition containing a copolymer emulsion, wherein the copolymer is 10 to 50% by weight of methacrylic acid 2- A pressure-sensitive adhesive composition in which ethylhexyl is copolymerized and the glass transition temperature of the copolymer is −25 ° C. or lower has been proposed (for example, see Patent Document 2).
JP 2004-54007 A JP 2001-254063 A

  However, the conventional pressure sensitive adhesive including Patent Document 1 as described above has low adhesion to an optical film, and when an optical film is usually attached to a liquid crystal display, the optical film is attached to the liquid crystal display. After that, if necessary, it is peeled once for position adjustment and re-attached (rework). With such an adhesive, the adhesive remains on the surface of the liquid crystal display at the time of peeling (hereinafter referred to as “adhesive”). "Remaining agent")), there is a problem that reworkability is not enough.

In addition, when handling an adhesive optical film in handling processes such as cutting or transporting the adhesive optical film, if the end of the adhesive optical film comes into contact with a person or a nearby object, the adhesive of that part is lost (hereinafter referred to as “adhesive”). It is called “lack”.) When the adhesive optical film lacking the adhesive is stuck on the liquid crystal display in this way, there is a problem that display failure occurs.
In addition, the conventional water-dispersed pressure-sensitive adhesive including Patent Document 2 as described above has improved adhesion to hydrophobic adherends such as polyolefin, but has particularly good adhesion to hydrophilic adherends such as glass. There is a problem that it is difficult to adhere firmly to a glass substrate such as a liquid crystal display.

Furthermore, the pressure-sensitive adhesive laminated as the pressure-sensitive adhesive optical film is required to have high heat resistance that does not cause defects even under severe heating. Further, depending on the application, it may be used not only under severe heating conditions but also under severe heating and humidification conditions, and high moisture and heat resistance is also required.
An object of the present invention is to use a pressure-sensitive adhesive optical film provided with a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive composition having high adhesion to a glass substrate and having high heat resistance and heat and moisture resistance, and the pressure-sensitive adhesive optical film. Another object of the present invention is to provide an image display apparatus.

In order to achieve the above object, the pressure-sensitive adhesive optical film of the present invention includes an optical film, a pressure-sensitive adhesive layer laminated on at least one surface of the optical film, and the optical film and the pressure-sensitive adhesive layer interposed therebetween. The pressure-sensitive adhesive layer comprises a pressure-sensitive adhesive composition prepared by polymerizing a raw material monomer, and the pressure-sensitive adhesive composition has a carbon number of 4 to 4 carbon atoms as a raw material monomer. is 18, the alkyl group is a straight-chain or branched alkyl and (meth) acrylic acid alkyl ester, an unsaturated carboxylic acid and / or carboxyalkyl acrylates, phosphoric acid group-containing represented by the following general formula (1) and vinyl monomers, containing the alkoxysilyl group-containing vinyl monomer, the mixing ratio of the raw material monomer, based on 100 parts by weight of the raw material monomer, Serial (meth) acrylic acid alkyl ester is 60 to 99 parts by weight, the unsaturated carboxylic acid, carboxyethyl acrylate, wherein the phosphoric acid group-containing vinyl monomers and the alkoxy total amount from 1 to 40 parts by weight of the silyl group-containing vinyl monomer In the raw material monomer, the carboxyl group concentration of the unsaturated carboxylic acid and carboxyalkyl acrylate is 0.05 to 1.50 mmol / g, and the phosphate group concentration is 0.01 to 0.45 mmol / g. g, and the undercoat layer is characterized by containing an oxazoline group-containing polymer.

(In general formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a polyoxyalkylene group represented by the following general formula (2), and X represents the following general formula (3). A phosphoric acid group or a salt thereof.

  (In general formula (2), n represents an integer of 1 to 4, and m represents an integer of 2 or more.)

(In General Formula (3), M ¹ and M ² each independently represent a hydrogen atom or a cation.)
Further, the pressure-sensitive adhesive optical film of the present invention, the mixing ratio of the raw material monomer, based on 100 parts by weight of the raw material monomer, the (meth) acrylic acid alkyl ester is 60 to 99 parts by weight, the unsaturated carboxylic acid It is preferable that the carboxyalkyl acrylate is 0.5 to 15 parts by weight, the phosphoric acid group-containing vinyl monomer is 0.5 to 20 parts by weight, and the alkoxysilyl group-containing vinyl monomer is 39 parts by weight or less.

In the pressure-sensitive adhesive optical film of the present invention, it is preferable that the blending ratio of the alkoxysilyl group-containing vinyl monomer is 0.001 to 1 part by weight with respect to 100 parts by weight of the total amount of raw material monomers.
In the pressure-sensitive adhesive optical film of the present invention, it is preferable that the pressure-sensitive adhesive composition is a water-dispersed pressure-sensitive adhesive composition.

Further, the pressure-sensitive adhesive optical film of the present invention, the subbing layer, it is preferable that a mixture of a polymer compound containing a plurality of oxazoline group-containing polymer and mosquitoes carboxyl group.
In the pressure-sensitive adhesive optical film of the present invention, it is preferable that the oxazoline group-containing polymer includes a main chain composed of an acrylic skeleton, and includes an oxazoline group in a side chain of the main chain.

Further, the pressure-sensitive adhesive optical film of the present invention, before the polymer compound containing a plurality of listen carboxyl group has a number average molecular weight, it is preferable that at least 1,000.
The image display device of the present invention is characterized by using at least one of the above-mentioned adhesive optical films.

  The pressure-sensitive adhesive optical film of the present invention has high adhesive strength with a glass substrate and can achieve strong adhesion. Furthermore, since it has high heat resistance and heat-and-moisture resistance, excellent durability can be obtained even in a high-temperature atmosphere or a high-temperature and high-humidity atmosphere. Therefore, the image display device of the present invention in which the adhesive optical film of the present invention is used can achieve high durability.

The pressure-sensitive adhesive optical film of the present invention includes an optical film, a pressure-sensitive adhesive layer laminated on at least one surface of the optical film, and an undercoat layer interposed between the optical film and the pressure-sensitive adhesive layer.
In the pressure-sensitive adhesive optical film of the present invention, the pressure-sensitive adhesive layer is composed of a pressure-sensitive adhesive composition, and this pressure-sensitive adhesive composition is a water-dispersed pressure-sensitive adhesive composition, and the raw material monomer has an alkyl group having 4 to 4 carbon atoms. 18 (meth) acrylic acid alkyl ester, carboxyl group-containing vinyl monomer, a phosphoric acid group-containing vinyl monomer and the noted monomers copolymerizable with the copolymerizable vinyl monomer represented by the following general formula (1) And the blending ratio of the raw material monomers is 60 to 99 parts by weight of the (meth) acrylic acid alkyl ester with respect to 100 parts by weight of the total amount of the raw material monomers, and the carboxyl group-containing vinyl monomer, the phosphate group-containing vinyl monomer, and The total amount of the copolymerizable vinyl monomer is 1 to 40 parts by weight, and the carboxyl group concentration in the raw material monomer is 0.05 to 1.50 mmol / g. Ri, and phosphoric acid group concentration is 0.01 to 0.45 mmol / g.

(In general formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a polyoxyalkylene group, and X represents a phosphoric acid group or a salt thereof.)
Examples of the (meth) acrylic acid alkyl ester having 4 to 18 carbon atoms in the alkyl group include a methacrylic acid alkyl ester and / or an acrylic acid alkyl ester, and examples thereof include butyl (meth) acrylate and isobutyl (meth) acrylate. , Sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, (meth) Heptyl acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate , Isodecyl (meth) acrylate, undecyl (meth) acrylate, (Meth) dodecyl acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate ( Examples include (meth) acrylic acid alkyl (linear or branched alkyl having 4 to 18 carbon atoms) ester. These (meth) acrylic acid alkyl esters may be used alone or in combination, and the blending ratio (weight ratio) is, for example, 1/99 to 55/45 (butyl acrylate / 2-ethylhexyl acrylate). ), Preferably 5/95 to 60/40.

The mixing ratio of the (meth) acrylic acid alkyl ester is, for example, 60 to 99 parts by weight, preferably 70 to 99 parts by weight, more preferably 80 to 99 parts by weight, with respect to 100 parts by weight of the total amount of raw material monomers. Particularly preferred is 80 to 98 parts by weight.
Examples of the carboxyl group-containing vinyl monomers, Ri vinyl monomer der having a carboxyl group in the molecule, as an essential component, an unsaturated carboxylic acid and / or carboxyalkyl acrylate.
Examples of the unsaturated carboxylic acid include unsaturated carboxylic acids such as (meth) acrylic acid, fumaric acid, maleic acid, itaconic acid, crotonic acid, and cinnamic acid .
The carboxyalkyl acrylates, for example, beta-carboxyethyl acrylate, carboxypentyl acrylate, .omega.-carboxy - polycaprolactone monoacrylate and the like.
Moreover, as a carboxyl group-containing vinyl monomer, as an optional component, for example, unsaturated dicarboxylic acid monoesters such as monomethyl itaconate, monobutyl itaconate, 2-acryloyloxyethylphthalic acid, for example, 2-methacryloyloxyethyl trimellitic acid, 2-methacryloyloxy etc. acryloyl unsaturated tricarboxylic acid monoester such as oxyethyl pyromellitic acid may also be mentioned.

Examples of the carboxyl group-containing vinyl monomer include, as optional components, unsaturated dicarboxylic acid anhydrides such as itaconic anhydride, maleic anhydride, and fumaric anhydride.
These carboxyl group-containing vinyl monomers are used alone or in combination as appropriate.
The carboxyl group concentration of the carboxyl group-containing vinyl monomer is, for example, 0.05 to 1.50 mmol / g, preferably 0.20 to 0.90 mmol / g in the raw material monomer. In order to make the carboxyl group concentration of the carboxyl group-containing vinyl monomer within the above-mentioned range, although depending on the molecular weight of the carboxyl group-containing vinyl monomer, the blending ratio of the carboxyl group-containing vinyl monomer is set to 100 parts by weight of the total amount of raw material monomers. For example, it is set to 0.4 to 41 parts by weight, preferably 1.4 to 25 parts by weight. Moreover, the compounding ratio of the carboxyl group-containing vinyl monomer is, for example, 0.5 to 15 parts by weight, preferably 0.5 to 100 parts by weight with respect to the total amount of raw material monomers within the above-described range of the carboxyl group concentration. It can also be set to 10 parts by weight, more preferably 1 to 10 parts by weight. When the amount is less than the above range, the cohesive force of the water-dispersed pressure-sensitive adhesive composition is lowered, and when it is more than the above-mentioned range, stability during emulsion polymerization and water resistance of the water-dispersed pressure-sensitive adhesive composition are lowered.

The carboxyl group concentration of the carboxyl group-containing vinyl monomer is calculated by the following formula.
Carboxyl group concentration [mmol / g] = 1000 × {(Blend weight of carboxyl group-containing vinyl monomer [g]) / (Molecular weight of carboxyl group-containing vinyl monomer [g / mol])} / (Total weight of raw material monomers [g] )
In the above formula, the total weight of raw material monomers is a weight that does not include water and additives such as an initiator, an emulsifier, a chain transfer agent, a crosslinking agent, and a viscosity modifier, which will be described later.

  The phosphate group-containing vinyl monomer represented by the following general formula (1) is a polyalkylene oxide (meth) acrylate phosphate ester,

(In general formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a polyoxyalkylene group, and X represents a phosphoric acid group or a salt thereof.)
The polyoxyalkylene group represented by R ² is represented by the following general formula (2),

(In general formula (2), n represents an integer of 1 to 4, and m represents an integer of 2 or more.)
For example, a polyoxyethylene group (corresponding to n = 2 in the general formula (2)), a polyoxypropylene group (corresponding to n = 3 in the general formula (2)) and a random, block or graft unit thereof. The degree of polymerization of these oxyalkylene groups, that is, in the general formula (2), m is preferably 4 or more and usually 40 or less.

The higher the degree of polymerization of the oxyalkylene group, the higher the mobility of the side chain having the phosphate group, and the quicker interaction with the glass improves the adhesion of the water-dispersed pressure-sensitive adhesive composition to the glass substrate. To do.
Further, the phosphate group represented by X or a salt thereof is represented by the following general formula (3),

(In General Formula (3), M ¹ and M ² each independently represent a hydrogen atom or a cation.)
The cation is not particularly limited, and examples thereof include inorganic cations such as alkali metals such as sodium and potassium, alkaline earth metals such as calcium and magnesium, and organic cations such as quaternary amines.

  Moreover, what is generally marketed can be used for a phosphoric acid group containing vinyl monomer, for example, Sipomer PAM-100 (made by Rhodia Nikka Co., Ltd.), Phosmer PE (made by Unichemical Co., Ltd.), Phosmer. Mono [poly (ethylene oxide) methacrylate] phosphate esters such as PEH (Unichemical Co., Ltd.) and Phosmer PEDM (Unichemical Co., Ltd.), for example, Sipomer PAM-200 (Rodia Nikka Co., Ltd.), Mono [poly (propylene oxide) methacrylate] phosphates such as Phosmer PP (manufactured by Unichemical Co., Ltd.), Phosmer PPH (manufactured by Unichemical Co., Ltd.), and Phosmer PPDM (manufactured by Unichemical Co., Ltd.). .

These phosphate group-containing vinyl monomers are used alone or in combination as appropriate.
The phosphate group concentration of the phosphate group-containing vinyl monomer is, for example, 0.01 to 0.45 mmol / g, preferably 0.02 to 0.20 mmol / g in the raw material monomer. In order to make the phosphoric acid group concentration of the phosphoric acid group-containing vinyl monomer within the above-mentioned range, although depending on the molecular weight of the phosphoric acid group-containing vinyl monomer, the blending ratio of the phosphoric acid group-containing vinyl monomer is changed to a total amount of raw material monomers of 100. For example, 0.4 to 22 parts by weight, preferably 0.8 to 10 parts by weight with respect to parts by weight. The blending ratio of the phosphoric acid group-containing vinyl monomer is, for example, 0.5 to 20 parts by weight, preferably 0. It can also be set to 5 to 10 parts by weight, more preferably 1 to 5 parts by weight. If the amount is less than the above range, the effect of improving the adhesion to the glass substrate cannot be obtained sufficiently. If the amount is more than the above range, the stability during emulsion polymerization is lowered, or the elastic modulus of the water-dispersed pressure-sensitive adhesive composition is reduced. The adhesiveness may decrease due to the increase in the thickness.

The phosphate group concentration of the phosphate group-containing vinyl monomer is calculated by the following formula.
Phosphate group concentration [mmol / g] = 1000 × {(Blend weight of phosphate group-containing vinyl monomer [g]) / (Molecular weight of phosphate group-containing vinyl monomer [g / mol])} / (Total weight of raw material monomers) [G])
In the above formula, the total weight of raw material monomers is a weight that does not include water and additives such as an initiator, an emulsifier, a chain transfer agent, a crosslinking agent, and a viscosity modifier.

As the copolymerizable vinyl monomer copolymerizable with the above-mentioned monomer , an alkoxysilyl group-containing vinyl monomer can be mentioned as an essential component. Examples of the alkoxysilyl group-containing vinyl monomer include silicone-based (meth) acrylate monomers and silicone-based vinyl monomers.
Examples of the silicone-based (meth) acrylate monomer include (meth) acryloyloxymethyl-trimethoxysilane, (meth) acryloyloxymethyl-triethoxysilane, 2- (meth) acryloyloxyethyl-trimethoxysilane, 2- ( (Meth) acryloyloxyethyl-triethoxysilane, 3- (meth) acryloyloxypropyl-trimethoxysilane, 3- (meth) acryloyloxypropyl-triethoxysilane, 3- (meth) acryloyloxypropyl-tripropoxysilane, 3 -(Meth) acryloyloxypropyl-triisopropoxysilane, (meth) acryloyloxyalkyl-trialkoxysilane such as 3- (meth) acryloyloxypropyl-tributoxysilane, for example, (meth) acryloyloxymethyl-methyl Dimethoxysilane, (meth) acryloyloxymethyl-methyldiethoxysilane, 2- (meth) acryloyloxyethyl-methyldimethoxysilane, 2- (meth) acryloyloxyethyl-methyldiethoxysilane, 3- (meth) acryloyloxypropyl -Methyldimethoxysilane, 3- (meth) acryloyloxypropyl-methyldiethoxysilane, 3- (meth) acryloyloxypropyl-methyldipropoxysilane, 3- (meth) acryloyloxypropyl-methyldiisopropoxysilane, 3- (Meth) acryloyloxypropyl-methyldibutoxysilane, 3- (meth) acryloyloxypropyl-ethyldimethoxysilane, 3- (meth) acryloyloxypropyl-ethyldiethoxysilane, 3- (meth) acryloyloxypropyl Ethyl dipropoxysilane, 3- (meth) acryloyloxypropyl-ethyldiisopropoxysilane, 3- (meth) acryloyloxypropyl-ethyldibutoxysilane, 3- (meth) acryloyloxypropyl-propyldimethoxysilane, 3- ( Examples include (meth) acryloyloxyalkyl-alkyl dialkoxysilanes such as (meth) acryloyloxypropyl-propyldiethoxysilane, and (meth) acryloyloxyalkyl-dialkyl (mono) alkoxysilanes corresponding to these.
Examples of the silicone-based vinyl monomer include vinyltrialkoxysilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, and vinyl corresponding to these. Alkyldialkoxysilanes and vinyldialkylalkoxysilanes such as vinylmethyltrimethoxysilane, vinylmethyltriethoxysilane, β-vinylethyltrimethoxysilane, β-vinylethyltriethoxysilane, γ-vinylpropyltrimethoxysilane, γ -Vinylalkyl such as vinylpropyltriethoxysilane, γ-vinylpropyltripropoxysilane, γ-vinylpropyltriisopropoxysilane, γ-vinylpropyltributoxysilane Another trialkoxysilane, these correspond and (vinyl) alkyl dialkoxy silanes, and the like (vinyl alkyl) dialkyl (mono) alkoxysilanes.
Moreover, as a copolymerizable vinyl monomer, functional group containing vinyl monomers other than carboxylic acid are mentioned as an arbitrary component, for example.
Examples of such functional group-containing vinyl monomers include vinyl acetate, vinyl propionate and other carboxylic acid vinyl esters, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, and the like. Hydroxyl group-containing vinyl monomers such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N- Amide group-containing unsaturated monomers such as methoxymethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-vinylcarboxylic acid amide, for example, glycidyl (meth) acrylate, (meta ) Methyl glycy acrylate Glycidyl group-containing unsaturated monomers such as styrene, for example, cyano group-containing unsaturated monomers such as acrylonitrile and methacrylonitrile, for example, isocyanate group-containing unsaturated monomers such as 2-methacryloyloxyethyl isocyanate, such as styrene sulfonic acid, allyl Sulfonic acid group-containing unsaturated monomers such as sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, For example, maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N-phenylmaleimide, such as N-methylitaconimide, N-ethylitaconimide N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexylitaconimide, N-cyclohexyl leuconconimide, N-lauryl itaconimide and other itaconimide monomers such as N- (meth) acryloyloxymethylene succinimide, Succinimide monomers such as N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl-8-oxyoctamethylene succinimide, such as polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate And glycol-based acrylic ester monomers such as (meth) acrylic acid methoxyethylene glycol and (meth) acrylic acid methoxypolypropylene glycol.

Furthermore, a polyfunctional monomer is mentioned as an above-described functional group containing vinyl monomer.
Examples of the multifunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and tetraethylene glycol di (meth) acrylate. (Mono or poly) alkylene glycol di (meth) such as (mono or poly) ethylene glycol di (meth) acrylate and (mono or poly) propylene glycol di (meth) acrylate such as propylene glycol di (meth) acrylate In addition to acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol Examples include tall tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and divinylbenzene. Examples of the polyfunctional monomer include epoxy acrylate, polyester acrylate, and urethane acrylate.

As the copolymerizable vinyl monomer, in addition to the above alkoxysilyl group-containing vinyl monomer, as an optional component, for example, an aromatic vinyl monomer such as styrene, for example, methyl (meth) acrylate, (meth) acrylic Alkyl (meth) acrylates (linear or branched alkyls having 1 to 3 carbon atoms) such as ethyl acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, for example, cyclohexyl (meth) acrylate, (meta ) (Meth) acrylic acid alicyclic hydrocarbon esters such as bornyl acrylate, isobornyl (meth) acrylate, for example, (meth) acrylic aryl esters such as phenyl (meth) acrylate, for example, (meth) acrylic acid Alkoxy group-containing unsaturated monomers such as methoxyethyl, ethoxyethyl (meth) acrylate, For example, olefin monomers such as ethylene, propylene, isoprene, butadiene and isobutylene, vinyl ether monomers such as vinyl ether, halogen atom-containing unsaturated monomers such as vinyl chloride, and others such as N-vinylpyrrolidone, N- (1-methylvinyl) pyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinyl Examples include vinyl group-containing heterocyclic compounds such as morpholine and tetrahydrofurfuryl (meth) acrylate, for example, acrylate monomers containing halogen atoms such as fluorine atoms such as fluorine (meth) acrylate.

These copolymerizable vinyl monomers are used alone or in combination as appropriate.
By using an alkoxysilyl group-containing vinyl monomer as a copolymerizable vinyl monomer, it is introduced alkoxysilyl groups in the polymer chain can form a crosslinked structure by the reaction of it with each other. In particular, in a water-dispersed pressure-sensitive adhesive composition, the cross-linking agent described later has a non-uniform cross-linking structure, and terminal peeling is likely to occur. However, when an alkoxysilyl group-containing monomer is used, a uniform cross-linked structure can be formed, so that adhesion and fixation to a glass substrate can be improved. In addition, the alkoxysilyl group can interact with the glass substrate to enhance the adhesion to the glass substrate.

The mixing ratio of the copolymerizable vinyl monomer over, based on 100 parts by weight of the total amount of the raw material monomer, for example, 39 parts by weight or less, preferably, 19 parts by weight or less, still more preferably not more than 18 parts by weight. When the copolymerizable vinyl monomer is an alkoxysilyl group-containing vinyl monomer, the blending ratio is, for example, 0.001 to 1 part by weight, preferably 0 with respect to 100 parts by weight of the total amount of raw material monomers. 0.005 to 0.1 part by weight. If the alkoxysilyl group-containing vinyl monomer is less than the above range, crosslinking by the alkoxysilyl group is insufficient, leading to a decrease in cohesive strength of the water-dispersed pressure-sensitive adhesive composition, water-dispersed adhesive composition and glass If the adhesiveness with the substrate cannot be improved and the amount is larger than the above range, the stability during emulsion polymerization and the adhesiveness may be lowered.

  Moreover, among the above-mentioned raw material monomers, the total amount of the above-mentioned carboxyl group-containing vinyl monomer, phosphoric acid group-containing vinyl monomer and copolymerizable vinyl monomer is such that the blending ratio is, for example, 100 parts by weight of the total amount of raw material monomers. 1 to 40 parts by weight, preferably 1 to 30 parts by weight, more preferably 1 to 20 parts by weight, and particularly preferably 2 to 20 parts by weight.

And in order to prepare a water dispersion-type adhesive composition, the above-mentioned raw material monomer is copolymerized by polymerization methods, such as emulsion polymerization, for example.
In emulsion polymerization, for example, a polymerization initiator, an emulsifier, and, if necessary, a chain transfer agent are appropriately blended in water together with the above-described raw material monomers for copolymerization. More specifically, for example, known emulsion polymerization methods such as a batch charging method (batch polymerization method), a monomer dropping method, and a monomer emulsion dropping method can be employed. In the monomer dropping method, continuous dropping or divided dropping is appropriately selected. Although reaction conditions etc. are selected suitably, superposition | polymerization temperature is 20-90 degreeC, for example.

  The polymerization initiator is not particularly limited, and a polymerization initiator usually used for emulsion polymerization is used. For example, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylpropionamidine) disulfate, 2,2′-azobis (2-methylpropionamidine) dihydrochloride, 2, 2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, 2,2′-azobis (N, N Azo initiators such as' -dimethyleneisobutylamidine), 2,2'-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, for example, persulfate such as potassium persulfate and ammonium persulfate Salt-based initiators, for example, peroxide-based initiators such as benzoyl peroxide, t-butyl hydroperoxide, and hydrogen peroxide, for example, substituted ethers such as phenyl-substituted ethane. For example, carbonyl initiators such as aromatic carbonyl compounds, redox initiators such as a combination of persulfate and sodium bisulfite, a combination of peroxide and sodium ascorbate, etc. It is done.

These polymerization initiators are suitably used alone or in combination.
Of these polymerization initiators, azo initiators are preferably used.
The mixing ratio of the polymerization initiator is appropriately selected, and is, for example, 0.005 to 1 part by weight with respect to 100 parts by weight of the total amount of raw material monomers.
Note that the dissolved oxygen concentration in the monomer solution may be reduced by nitrogen substitution before or while blending the above-described raw material monomer with the polymerization initiator.

  The emulsifier is not particularly limited, and a known emulsifier usually used for emulsion polymerization is used. For example, sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkyl phenyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene Anionic emulsifiers such as sodium alkylsulfosuccinate, for example, nonionic emulsifiers such as polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, and polyoxyethylene polyoxypropylene block polymer.

Further, radically polymerizable (reactive) emulsifiers (for example, Aqualon HS-10 (for example, Aqualon HS-10) in which radically polymerizable functional groups (reactive groups) such as propenyl groups and allyl ether groups are introduced into these anionic emulsifiers and nonionic emulsifiers. Daiichi Kogyo Seiyaku Co., Ltd.), Latemul PD-104 (Kao Co., Ltd.)) and the like.
These emulsifiers are used alone or in combination as appropriate. Moreover, the mixture ratio of an emulsifier is 0.2-10 weight part with respect to 100 weight part of total amounts of a raw material monomer, Preferably, it is 0.5-5 weight part.

The chain transfer agent adjusts the molecular weight of the water-dispersed pressure-sensitive adhesive composition as necessary, and a chain transfer agent usually used for emulsion polymerization is used. Examples thereof include mercaptans such as 1-dodecanethiol, mercaptoacetic acid, 2-mercaptoethanol, 2-ethylhexyl thioglycolate, and 2,3-dimethylcapto-1-propanol.
These chain transfer agents are appropriately used alone or in combination. Moreover, the mixture ratio of a chain transfer agent is 0.001-0.5 weight part with respect to 100 weight part of total amounts of a raw material monomer, for example.

And the copolymer obtained by such emulsion polymerization can be prepared as an emulsion (water dispersion) of a water-dispersed pressure-sensitive adhesive composition.
The water-dispersed pressure-sensitive adhesive composition may be prepared, for example, by polymerizing the above-described raw material monomers by a method that does not use an organic solvent other than emulsion polymerization, and then dispersing in water using the above-described emulsifier. it can.

  Moreover, you may mix | blend a crosslinking agent with a water dispersion-type adhesive composition as needed according to the objective and use. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, and a metal chelate crosslinking agent. These crosslinking agents are not particularly limited, and oil-soluble or water-soluble crosslinking agents are used. These crosslinking agents are suitably used alone or in combination, and the blending ratio thereof is, for example, 0.1 to 10 parts by weight with respect to 100 parts by weight of the total amount of raw material monomers.

The water-dispersed pressure-sensitive adhesive composition is adjusted to, for example, pH 7-9, preferably pH 7-8, for example, with ammonia water for the purpose of improving the stability of the emulsion.
Furthermore, the water-dispersed pressure-sensitive adhesive composition includes a viscosity modifier, and if necessary, a release modifier, a plasticizer, a softener, a filler, a colorant (pigment, dye, etc.), an anti-aging agent, and a surfactant. For example, additives that are usually added to the water-dispersed pressure-sensitive adhesive composition may be appropriately added. The mixing ratio of these additives is not particularly limited, and can be appropriately selected.

The viscosity modifier is not particularly limited, and examples thereof include an acrylic thickener.
The gel fraction of the water-dispersed pressure-sensitive adhesive composition (solid content) thus prepared is, for example, 50 to 100% by weight, and preferably 70 to 100% by weight. When the gel fraction is lower than the above-described value, foaming or peeling may occur when this water-dispersed pressure-sensitive adhesive composition is applied to a pressure-sensitive adhesive optical film and used in a high-temperature and high-humidity atmosphere.

The gel fraction can be calculated by the following formula when the water-dispersed pressure-sensitive adhesive composition is covered with a Teflon sheet (registered trademark) and immersed in ethyl acetate for 7 days.
Gel fraction (% by weight) = (weight of water-dispersed pressure-sensitive adhesive composition adhering to the Teflon sheet after immersion) / weight of water-dispersed pressure-sensitive adhesive composition before immersion) × 100
In the pressure-sensitive adhesive optical film of the present invention, the undercoat layer contains an oxazoline group-containing polymer.

The oxazoline group-containing polymer includes, for example, a main chain composed of an acrylic skeleton or a styrene skeleton, and has an oxazoline group in the side chain of the main chain, and preferably includes a main chain composed of an acrylic skeleton. And an oxazoline group-containing acrylic polymer having an oxazoline group in the side chain of the main chain.
Examples of the oxazoline group include 2-oxazoline group, 3-oxazoline group, 4-oxazoline group, and preferably 2-oxazoline group.

  The 2-oxazoline group is generally represented by the following general formula (4).

(In general formula (4), R ³ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, a halogen atom, an alkyl group, an aralkyl group, a phenyl group or a substituted phenyl group.)
The number average molecular weight of the oxazoline group-containing polymer is, for example, 5000 or more, preferably 10,000 or more, and usually 1000000 or less. When the number average molecular weight is lower than 5000, the strength of the undercoat layer is insufficient, causing cohesive failure, and the anchoring force may not be improved. When the number average molecular weight is higher than 1,000,000, workability may be inferior. The oxazoline group-containing polymer has an oxazoline value of, for example, 1500 g solid / eq. Hereinafter, preferably, 1200 g solid / eq. It is as follows. The oxazoline value is 1500 g solid / eq. If it is larger, the amount of the oxazoline group contained in the molecule decreases, and the anchoring force may not be improved.

Since the oxazoline group-containing polymer reacts with a functional group (such as a carboxyl group or a hydroxyl group) contained in the water-dispersed pressure-sensitive adhesive composition at a relatively low temperature, the oxazoline group-containing polymer can be contained in the undercoat layer. For example, it reacts with a functional group in the pressure-sensitive adhesive layer and can adhere firmly.
As the oxazoline group-containing polymer, a general commercial product is usually used. Specifically, Epocros WS-500 (aqueous solution type, solid content 40%, main chain: acrylic, pH 7-9, oxazoline value 220 g solid / eq , Manufactured by Nippon Shokubai Co., Ltd.), Epocross WS-700 (aqueous solution type, solid content 25%, main chain: acrylic, pH 7-9, oxazoline value 220 g solid / eq., Manufactured by Nippon Shokubai Co., Ltd.) Oxazoline group-containing acrylic polymer, for example, Epocross K-1000 series (emulsion type, solid content 40%, main chain: styrene / acrylic, oxazoline value 1100 g solid / eq., PH 7-9, manufactured by Nippon Shokubai Co., Ltd.) Epocross K-2000 series (emulsion type, solid content 40%, main chain: styrene / a Lil system, pH 7-9, oxazoline value 550 g solid / eq., And the like oxazoline group-containing acrylic / styrene polymers, such as KK Nippon Shokubai). From the viewpoint of improving adhesion, an aqueous solution type oxazoline group-containing acrylic polymer is preferable to an emulsion type containing an emulsifier.

With such an oxazoline group-containing acrylic polymer, the affinity with the water-dispersed pressure-sensitive adhesive composition is good, the adhesion between the optical film and the water-dispersed pressure-sensitive adhesive composition is increased, and high heat resistance is achieved. It is possible to obtain a pressure-sensitive adhesive optical film having
Such an oxazoline group-containing polymer is generally dissolved or dispersed in a solution such as an organic solvent or water, and is prepared as a resin solution or an aqueous dispersion containing the oxazoline group-containing polymer. In addition, it is preferable to prepare as an aqueous dispersion from a viewpoint of preventing deterioration of the optical film.

In the pressure-sensitive adhesive optical film of the present invention, the undercoat layer is preferably composed of a mixture of an oxazoline group-containing polymer and a compound containing a plurality of carboxyl groups (that is, a compound containing a plurality of carboxyl groups ) .

The compounds containing multiple carboxyl group, a polymer compound, for example, acrylic acid, polymers of unsaturated compounds, such as methacrylic acid (polyacrylic acid, polymethacrylic acid, etc.), for example, the unsaturated Copolymers of compounds, specifically copolymers of acrylic acid and methacrylic acid, copolymers of acrylic acid and maleic acid, copolymers of methacrylic acid and maleic acid, acrylic acid, methacrylic acid and maleic acid A copolymer etc. are mentioned. Preferably, a copolymer of acrylic acid and maleic acid is used.
In addition to the polymer compound (essential component) described above as a compound containing a plurality of carboxyl groups, as an optional component, for example, dicarboxylic acid compounds such as succinic acid, adipic acid, and phthalic acid, such as citric acid A saturated low molecular weight compound containing a plurality of carboxyl groups such as a tricarboxylic acid compound may be further contained.

The compound containing a plurality of carboxyl groups has a number average molecular weight (GPC measurement, standard polyethylene glycol equivalent) of, for example, 1000 or more, preferably 3000 to 200000.
Moreover, the carboxyl group which the compound containing a some carboxyl group has may form the salt with the cation all or one part.

Examples of the cation include inorganic cations such as potassium ion and sodium ion, for example, ammonium cations, and organic cations such as primary amine, secondary amine, and tertiary amine cations.
As the compound containing a plurality of carboxyl groups, generally commercially available products are used. Specifically, Poise 532A (acrylic acid / maleic acid copolymer ammonium salt, number average molecular weight of about 10,000, manufactured by Kao Corporation) ) And the like.

  A mixture of such an oxazoline group-containing polymer and a compound containing a plurality of carboxyl groups is generally dissolved or dispersed in a solution such as an organic solvent or water, and the oxazoline group-containing polymer and a plurality of carboxyl groups are combined. It is prepared as a resin solution or aqueous dispersion of a mixture with the contained compound. Preferably, the mixture is prepared as a water-dispersed mixture of an oxazoline group-containing polymer and a compound containing a plurality of carboxyl groups (water-dispersed polymer).

  In general, when a water-soluble material is used as the undercoat layer, if the thickness of the undercoat layer increases, the strength of the undercoat layer may decrease when used in a high-humidity atmosphere, resulting in interlaminar fracture. . However, if the undercoat layer is a mixture of an oxazoline group-containing polymer and a compound containing a plurality of carboxyl groups, the oxazoline group of the oxazoline group-containing polymer and the carboxyl group of the compound containing a plurality of carboxyl groups As a result of the reaction, the undercoat layer is cross-linked to become a stronger undercoat layer, and thus it is presumed that the heat resistance and heat-and-moisture resistance are increased and the adhesion is increased.

  The compounding ratio of the compound containing a plurality of carboxyl groups is, for example, 1 to 30 parts by weight, preferably 2 to 20 parts per 100 parts by weight of the total amount of the oxazoline group-containing polymer and the compound containing a plurality of carboxyl groups. Part by weight, more preferably 3 to 10 parts by weight. If the compound containing a plurality of carboxyl groups is less than 1 part by weight, the effect of crosslinking the undercoat layer may be reduced. When the compound containing a plurality of carboxyl groups is more than 30 parts by weight, the undercoat layer may become cloudy and optical properties may be deteriorated.

The optical film is not particularly limited as long as it has optical characteristics and is attached to a liquid crystal display or the like, and examples thereof include a polarizing film, a retardation film, a brightness enhancement film, and a viewing angle widening film.
As a polarizing film, what provided the transparent protective film on the single side | surface or both surfaces of a polarizer is used.

  The polarizer is not particularly limited, and examples thereof include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, ethylene / vinyl acetate copolymer partially saponified films, iodine and dichroism. Examples thereof include uniaxially stretched films dyed with dichroic substances such as dyes, and polyene-based oriented films such as polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Preferably, a polarizer obtained by uniaxially stretching a polyvinyl alcohol film with iodine is used.

  Examples of the transparent protective film include polyester polymer films such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymer films such as diacetyl cellulose and triacetyl cellulose, acrylic polymer films such as polymethyl methacrylate, polystyrene, acrylonitrile and styrene. Examples thereof include a styrene polymer film such as a polymer (AS resin), and a polycarbonate polymer film. In addition, polyethylene, polypropylene, polyolefin having a cyclo or norbornene structure, polyolefin polymer film such as ethylene / propylene copolymer, vinyl chloride polymer film, nylon, amide polymer film such as aromatic polyamide, imide polymer film, Sulfone polymer film, polyether sulfone polymer film, polyether ether ketone polymer film, polyphenylene sulfide polymer film, vinyl alcohol polymer film, vinylidene chloride polymer film, vinyl butyral polymer film, arylate polymer film, poly Of oxymethylene-based polymer film, epoxy-based polymer film, or blends of the above-mentioned polymers Irumu also include such.

The transparent protective film can also be formed as a cured layer of thermosetting or ultraviolet curable resin such as acrylic, urethane, acrylurethane, epoxy, and silicone.
As a transparent protective film, Preferably, a cellulose polymer is mentioned. The thickness in particular of a transparent protective film is not restrict | limited, For example, it is 500 micrometers or less, Preferably, it is 1-300 micrometers, More preferably, it is 5-200 micrometers.

In order to bond the polarizer and the transparent protective film, for example, an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based adhesive, a latex-based adhesive, a water-based polyester adhesive, or the like is used. Glue.
Examples of the retardation film include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, a liquid crystal polymer alignment film, and a liquid crystal polymer alignment layer supported by the film. The thickness of the retardation film is not particularly limited and is, for example, 20 to 150 μm.

  Examples of the polymer material include polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, Polyphenylene sulfide, polyphenylene oxide, polyallylsulfone, polyvinyl alcohol, polyamide, polyimide, polyolefin, polyvinyl chloride, cellulose polymer, or binary, ternary copolymers, graft copolymers, blends Such as things. These polymer materials become an oriented product (stretched film) by stretching or the like.

  Examples of the liquid crystalline polymer include various main chain types and side chain types in which a conjugated linear atomic group (mesogen) imparting liquid crystal orientation is introduced into the main chain or side chain of the polymer. It is done. As the main chain type liquid crystalline polymer, for example, a structure in which a mesogenic group is bonded at a spacer portion imparting flexibility, specifically, a nematic orientation polyester-based liquid crystalline polymer, a discotic polymer or a cholesteric polymer. Etc. As the side chain type liquid crystalline polymer, for example, polysiloxane, polyacrylate, polymethacrylate or polymalonate is used as the main chain skeleton, and the side chain is substituted by a nematic orientation-imparting para-substitution through a spacer portion composed of a conjugated atomic group. Examples thereof include those having a mesogenic part composed of a cyclic compound unit. These liquid crystalline polymers are prepared by, for example, applying a solution of a liquid crystalline polymer on an alignment-treated surface such as a surface of a thin film such as polyimide or polyvinyl alcohol formed on a glass plate, or an oblique deposition of silicon oxide. It is obtained by developing and heat treatment.

In addition, the retardation film may be, for example, a film for the purpose of expanding coloring or viewing angle due to birefringence of various wavelength films or liquid crystal layers, or may have a phase difference as appropriate depending on the purpose of use. Two or more retardation films may be laminated to control optical characteristics such as retardation.
Examples of brightness enhancement films are those that transmit linearly polarized light with a predetermined polarization axis and reflect other light, such as dielectric multilayer thin films and multilayer laminates of thin film films with different refractive index anisotropies. , Cholesteric liquid crystal polymer alignment films and those whose alignment liquid crystal layer is supported on a film substrate, such as those that reflect either left-handed or right-handed circularly polarized light and transmit other light, etc. Is mentioned.

  The viewing angle widening film is a film that widens the viewing angle so that the image can be seen relatively clearly even when the screen of the liquid crystal display is viewed from a slightly oblique direction rather than perpendicular to the screen. Examples thereof include an alignment film such as a film and a liquid crystal polymer, and a support in which an alignment layer such as a liquid crystal polymer is supported on a transparent substrate. Retardation films used as viewing angle widening films include birefringent polymer films stretched biaxially in the plane direction and thickness direction refractions stretched uniaxially in the plane direction and stretched in the thickness direction. A birefringent film such as a polymer having birefringence with a controlled rate or a tilted orientation film is used.

Hereinafter, with reference to FIG. 1, the manufacturing method of the adhesive optical film of this invention is demonstrated.
In order to obtain an adhesive optical film, first, the optical film 1 is prepared.
Then, the undercoat layer 2 is provided on one side of the optical film 1. In this description, the undercoat layer 2 is provided on one side of the optical film, but may be provided on both sides, although not shown, if necessary.

In order to provide the undercoat layer 2, for example, a resin solution or an aqueous dispersion of an oxazoline group-containing polymer or a mixture of an oxazoline group-containing polymer and a compound containing a plurality of carboxyl groups is applied to the optical film 1 by knife coating. It is directly coated and dried by a known coating method such as a method.
The thickness (thickness after drying) of the undercoat layer 2 is set to, for example, 1 to 500 nm, preferably 10 to 450 nm, and more preferably 20 to 400 nm. When the thickness of the undercoat layer 2 is set within the above-described range, the adhesion between the optical film 1 and the pressure-sensitive adhesive layer 3 can be sufficiently increased.

Next, an adhesive layer 3 is provided on one side of the optical film 1 with an undercoat layer 2 interposed.
In order to provide the pressure-sensitive adhesive layer 3, for example, a method of transferring the pressure-sensitive adhesive layer 3 from the release sheet 4 on which the pressure-sensitive adhesive layer 3 is formed to the above-described undercoat layer 2 can be mentioned. The release sheet 4 on which the pressure-sensitive adhesive layer 3 is formed is prepared by directly coating the release sheet 4 with a water-dispersed pressure-sensitive adhesive composition by a known coating method such as a knife coating method and drying it. can do. Further, in order to transfer the pressure-sensitive adhesive layer 3, the release sheet 4 on which the pressure-sensitive adhesive layer 3 is formed is brought into contact with the optical film 1 on which the undercoat layer 2 is provided. Thus, after bonding together, the release sheet 4 is peeled off from the adhesive layer 3.

In order to provide the pressure-sensitive adhesive layer 3, for example, the above-described undercoat layer 2 may be directly coated with a water-dispersed pressure-sensitive adhesive composition by a known coating method such as a knife coating method and dried. it can.
Examples of the release sheet 4 include paper, synthetic resin films such as polyethylene, polypropylene, and polyethylene terephthalate, rubber sheets, paper, cloth, nonwoven fabric, nets, foamed sheets, metal foils, and laminated sheet bodies thereof. In order to improve the peelability from the pressure-sensitive adhesive layer 3, the surface of the release sheet 4 may be subjected to treatments such as silicone treatment, long-chain alkyl treatment, and fluorine treatment as necessary.

The thickness (thickness after drying) of the pressure-sensitive adhesive layer 3 is set in the range of, for example, 1 to 100 μm, preferably 3 to 50 μm, and more preferably 5 to 40 μm.
Thus, the pressure-sensitive adhesive optical film of the present invention can be obtained by providing the pressure-sensitive adhesive layer 3 made of the pressure-sensitive adhesive composition with the undercoat layer 2 interposed on at least one surface of the optical film 1.

The adhesive optical film of the present invention thus obtained can be used in various industries as an optical film such as a polarizing film, a retardation film, a brightness enhancement film, and a viewing angle widening film without impairing the optical properties of the optical film. It is suitably used for applications.
In particular, since such an adhesive optical film has a high adhesive force between the adhesive layer 3 and the optical film 1, when adhering to a liquid crystal display or the like, after adhering the optical film 1 to a liquid crystal display, Even if it peels once and re-sticks (rework) for position adjustment, the adhesive remaining at the time of peeling can be effectively suppressed and reworked. Therefore, efficient sticking work can be realized.

Also, when handling in the usage process such as cutting and transporting the adhesive optical film, even if the end of the adhesive optical film comes into contact with people or other objects, it is possible to effectively suppress adhesive chipping. In addition, it is possible to effectively prevent display defects of the liquid crystal display due to the lack of adhesive.
Furthermore, since such an adhesive optical film has high heat resistance, if it is attached to a liquid crystal display or the like, it can effectively prevent a decrease in adhesion with the liquid crystal display even in a high temperature atmosphere. Excellent durability can be obtained even in an atmosphere.

Furthermore, since such an adhesive optical film has high moisture and heat resistance, if it is attached to a liquid crystal display or the like, it effectively prevents a decrease in adhesion to the liquid crystal display even in a high temperature and high humidity atmosphere. Excellent durability can be obtained even in a high temperature and high humidity atmosphere.
Since the pressure-sensitive adhesive optical film of the present invention has high heat resistance and moist heat resistance, if it is attached to the surface of a glass substrate of an image display device, it has excellent durability even in a high temperature atmosphere or a high temperature and high humidity atmosphere. Can be obtained.

Therefore, the adhesive optical film thus obtained is applied to the surface of a glass substrate of an image display device such as a liquid crystal display, an organic electroluminescence device (organic EL display device), a plasma display panel (PDP), and the undercoat layer 2. By sticking through the pressure-sensitive adhesive layer 3 interposing, an image display device excellent in durability can be obtained.
In addition, in a normal water-dispersed pressure-sensitive adhesive composition, a rosin resin, a tackifying resin such as an elastomer, and the like are added in order to improve adhesion to an adherend. Although the water-dispersed pressure-sensitive adhesive composition used is water-dispersed, it can increase adhesion without adding such a tackifying resin, so that it is low-cost and has high adhesion. A pressure-sensitive adhesive optical film comprising a pressure-sensitive adhesive layer made of an adhesive composition, and an image display device using such a pressure-sensitive adhesive optical film can be obtained.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to the following examples and comparative examples. In the following description, “parts” and “%” are based on weight unless otherwise specified.
Example 1
(Preparation of monomer pre-emulsion)
In the container, as raw material monomers, 100 parts of butyl acrylate, 5 parts of acrylic acid, 2 parts of mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0), 3-methacryloyloxypropyl -A trimethoxysilane (KBM-503, Shin-Etsu Chemical Co., Ltd.) 0.01 part was added and mixed, and the monomer mixture was prepared. Next, 13 g (2 parts (solid content)) of Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd.) and 360 g of ion-exchanged water as an emulsifier are added to 627 g of the prepared monomer mixture, and a homogenizer (Special Machine Co., Ltd.) is added. For 5 minutes at 5000 (1 / min) and forcibly emulsified to prepare a monomer pre-emulsion.
(Preparation of water-dispersed pressure-sensitive adhesive composition)
200 g of the monomer pre-emulsion prepared above and 330 g of ion-exchanged water were charged into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirrer, and then the reaction vessel was purged with nitrogen and 2,2 ′ -0.2 g of azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (VA-057, manufactured by Wako Pure Chemical Industries, Ltd.) was added and polymerized at 60 ° C for 1 hour. did. Next, 800 g of the remaining monomer pre-emulsion was dropped into the reaction vessel over 3 hours, and then polymerized for 3 hours. Thereafter, polymerization was performed at 60 ° C. for 3 hours while purging with nitrogen to obtain an emulsion solution of a water-dispersed pressure-sensitive adhesive composition having a solid content of 48%. Next, this was cooled to room temperature, 10% aqueous ammonia was added to adjust the pH to 8, and 3.0 g of acrylic thickener Aron B-500 (manufactured by Toagosei Co., Ltd.) was added. Thus, a water-dispersed pressure-sensitive adhesive composition was prepared.
(Preparation of optical film)
A polyvinyl alcohol film (thickness 80 μm) is stretched 5 times the original length in an aqueous iodine solution at 40 ° C., and then the polyvinyl alcohol film is pulled up from the aqueous iodine solution and dried at 50 ° C. for 4 minutes to obtain a polarizer. Obtained. A triacetyl cellulose film as a transparent protective film was adhered to both sides of the polarizer using a polyvinyl alcohol adhesive to obtain an optical film.
(Undercoating)
Undercoating is performed by using Epocros WS-500 (oxazoline group-containing acrylic polymer, manufactured by Nippon Shokubai Co., Ltd.) in a mixed solvent of water and ethanol (1: 1 by weight) with a solid content of 0.25% by weight. The diluted solution was applied to one side of the optical film using a wire bar # 5 and dried at 40 ° C. for 2 minutes for processing.
(Preparation of adhesive optical film)
The prepared water-dispersed pressure-sensitive adhesive composition was coated on a release film (polyethylene terephthalate substrate, Diafoil MRF38, manufactured by Mitsubishi Chemical Polyester Co., Ltd.), heat-treated at 100 ° C. for 2 minutes, and a thickness of 23 μm. The pressure-sensitive adhesive layer was formed and adhered to the treated surface of an optical film that had been previously primed to produce a pressure-sensitive adhesive optical film.

Example 2
In the undercoating treatment of Example 1, Epocros WS-500 (oxazoline group-containing acrylic polymer, manufactured by Nippon Shokubai Co., Ltd.) was changed to WS-700 (oxazoline group-containing acrylic polymer, manufactured by Nippon Shokubai Co., Ltd.). Except for the above, the same process as in Example 1 was performed to prepare an adhesive optical film.

Example 3
In the preparation of the monomer pre-emulsion of Example 1, 0.01 part of 3-methacryloyloxypropyl-trimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 3-methacryloyloxypropyl-trimethoxysilane (KBM- 503, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.02 part, and as an emulsifier, Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd.) 13 g (2 parts (solid content)), Aqualon HS-10 (No. 1) Monolithic pre-emulsion treated in the same manner as in Example 1 except that 19 g (3 parts (solid content)) manufactured by Ichi Kogyo Seiyaku Co., Ltd. was changed and 360 g of ion-exchanged water was changed to 354 g of ion-exchanged water. Was prepared. Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

  Next, in the preparation of the primer solution in the primer treatment of Example 1, the primer solution Epocross WS-500 (oxazoline group-containing acrylic polymer, manufactured by Nippon Shokubai Co., Ltd.) was changed to Epocross WS-700 (oxazoline group-containing acrylic). -Based polymer, manufactured by Nippon Shokubai Co., Ltd.) and Poise 532A (acrylic acid / maleic acid copolymer ammonium salt, number average molecular weight of about 10,000, manufactured by Kao Corporation) (mixing ratio is solid content ratio) 95: 5), except that the solid content of the primer solution was changed from 0.25 wt% to 2.0 wt%, the same treatment as in Example 1 was performed to prepare a primer solution, An adhesive optical film was produced.

Example 4
In the preparation of the monomer pre-emulsion of Example 1, 2 parts of mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0) were mixed with mono [poly (propylene oxide) methacrylate] phosphoric acid. The ester (average degree of polymerization of propylene oxide was about 5.0) was changed to 3 parts, and 13 g (2 parts (solid content)) of Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd.) as an emulsifier was added to Hightenol LA- A monomer pre-emulsion was prepared in the same manner as in Example 1 except that the amount was changed to 16 (made by Daiichi Kogyo Seiyaku Co., Ltd.) 13 g (2 parts (solid content)). Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

Subsequently, it processed like Example 2 and produced the adhesion type optical film.
Example 5
In the preparation of the monomer pre-emulsion of Example 1, 2 parts of mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0) were mixed with mono [poly (propylene oxide) methacrylate] phosphoric acid. The ester (average degree of polymerization of propylene oxide is about 5.0) was changed to 4 parts, and 13 g (2 parts (solid content)) of Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd.) as an emulsifier was used. 16 (Daiichi Kogyo Seiyaku Co., Ltd.) 19 g (3 parts (solid content)), except that ion-exchanged water 360 g was changed to ion-exchanged water 354 g. A monomer pre-emulsion was prepared. Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

Subsequently, it processed like Example 2 and produced the adhesion type optical film.
Example 6
In the same manner as in Example 5, a monomer pre-emulsion was prepared and a water-dispersed pressure-sensitive adhesive composition was prepared.
Next, in the preparation of the primer solution in the primer treatment of Example 1, the primer solution, Epocross WS-500 (oxazoline group-containing acrylic polymer, manufactured by Nippon Shokubai Co., Ltd.), WS-700 (oxazoline group-containing acrylic system) Polymer, manufactured by Nippon Shokubai Co., Ltd., and treated in the same manner as in Example 1 except that the solid content of the primer solution was changed from 0.25 wt% to 0.1 wt%. Was made.

Example 7
In the same manner as in Example 5, a monomer pre-emulsion was prepared, and a water-dispersed pressure-sensitive adhesive composition was prepared.
Next, in the preparation of the primer solution in the primer treatment of Example 1, the primer solution, Epocross WS-500 (oxazoline group-containing acrylic polymer, manufactured by Nippon Shokubai Co., Ltd.), WS-700 (oxazoline group-containing acrylic system) Polymer, manufactured by Nippon Shokubai Co., Ltd., and treated in the same manner as in Example 1 except that the solid content of the primer solution was changed from 0.25 wt% to 0.5 wt%. Was made.

Example 8
In the preparation of the monomer pre-emulsion of Example 1, 5 parts of acrylic acid was changed to 11 parts of β-carboxyethyl acrylate (Sipomer β-CEA, Rhodia Nikka Co., Ltd.) and mono [poly (propylene oxide) methacrylate. ] 2 parts of phosphate ester (average degree of polymerization of propylene oxide of about 5.0) was changed to 4 parts of mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0) Was processed in the same manner as in Example 1 to prepare a monomer pre-emulsion. Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

Subsequently, it processed like Example 2 and produced the adhesion type optical film.
Example 9
In the preparation of the monomer pre-emulsion of Example 1, 5 parts of acrylic acid were mixed with 0.5 part of acrylic acid and ω-carboxy-polycaprolactone monoacrylate (Aronix M-5300, average degree of polymerization of caprolactone groups about 2, Toagosei ( 18.8 parts), mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide about 5.0) 2 parts mono [poly (propylene oxide) methacrylate] Phosphoric ester (average degree of polymerization of propylene oxide of about 5.0) was changed to 4 parts, and 13 g (2 parts (solid content)) Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd.) as an emulsifier Except having changed to LA-16 (Daiichi Kogyo Seiyaku Co., Ltd.) 19g (3 parts (solid content)), it processed like Example 1, The Roh-mer pre-emulsion was prepared. Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

Subsequently, it processed like Example 2 and produced the adhesion type optical film.
Comparative Example 1
In the preparation of the monomer pre-emulsion of Example 1, mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0) was not added, but 3-methacryloyloxypropyl-trimethoxysilane ( Example except that 0.01 parts of KBM-503 (manufactured by Shin-Etsu Chemical Co., Ltd.) was changed to 0.06 parts of 3-methacryloyloxypropyl-trimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) A monomer pre-emulsion was prepared in the same manner as in No. 1. Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

Subsequently, it processed like Example 2 and produced the adhesion type optical film.
Comparative Example 2
In the same manner as in Comparative Example 1, a monomer pre-emulsion was prepared and a water-dispersed pressure-sensitive adhesive composition was prepared.
Next, in the preparation of the primer solution in the primer treatment of Example 1, the primer solution Epocross WS-500 (oxazoline group-containing acrylic polymer, manufactured by Nippon Shokubai Co., Ltd.) was used as a water-dispersed urethane resin (Takelac W511, (Mitsui Takeda Chemical Co., Ltd.) and a water-dispersed isocyanate curing agent (Takenate WD725, Mitsui Takeda Chemical Co., Ltd.) mixed solution (mixing ratio is 1: 1). A primer solution was prepared in the same manner as in Example 1 except that the solid content of the primer solution was changed from 0.25% by weight to 2.0% by weight to prepare an adhesive optical film.

Comparative Example 3
In the preparation of the monomer pre-emulsion of Example 1, mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0) was not added, but 3-methacryloyloxypropyl-trimethoxysilane ( Example except that 0.01 parts of KBM-503 (manufactured by Shin-Etsu Chemical Co., Ltd.) was changed to 0.02 parts of 3-methacryloyloxypropyl-trimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) A monomer pre-emulsion was prepared in the same manner as in No. 1. Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

  Subsequently, in the preparation of the primer solution in the primer treatment of Example 1, the primer solution Epocross WS-500 (oxazoline group-containing acrylic polymer, manufactured by Nippon Shokubai Co., Ltd.) was replaced with Poliment SK-1000 (ethyleneimine modified acrylic). The polymer was treated in the same manner as in Example 1 except that the solid content of the primer solution was changed to 2.0% by weight. A film was prepared.

Comparative Example 4
In the preparation of the monomer pre-emulsion of Example 1, 2 parts of mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0) were mixed with mono [poly (ethylene oxide) methacrylate] phosphate ester ( The average polymerization degree of ethylene oxide was changed to 2 parts, and as an emulsifier, 13 g (2 parts (solid content)) of Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd.) was added to Latemul PD-104 (Kao ( Co., Ltd., 20% aqueous solution) 65 g (2 parts (solid content)), except that ion-exchanged water 360 g was changed to ion-exchanged water 308 g. Was prepared. Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1.

Subsequently, it processed similarly to the comparative example 3, and produced the adhesion type optical film.
Comparative Example 5
In the preparation of the monomer pre-emulsion of Example 1, 5 parts of acrylic acid was changed to 20 parts of acrylic acid, and mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide was about 5.0). A monomer pre-emulsion was prepared in the same manner as in Example 1 except that it was not added. Subsequently, polymerization was carried out in the same manner as in Example 1. However, since it aggregated during polymerization, a water-dispersed pressure-sensitive adhesive composition could not be obtained.

Comparative Example 6
In the preparation of the monomer pre-emulsion of Example 1, acrylic acid was not added, and 2 parts of mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0) Ethylene oxide) methacrylate] phosphoric acid ester (average degree of polymerization of ethylene oxide: about 5.5) A monomer pre-emulsion was prepared in the same manner as in Example 1 except that the amount was changed to 25 parts. Subsequently, polymerization was carried out in the same manner as in Example 1. However, since it aggregated during polymerization, a water-dispersed pressure-sensitive adhesive composition could not be obtained.

In Table 1, the monomer composition is expressed in parts by weight. In Table 1, the carboxyl group concentration and the phosphate group concentration are also shown.
In Table 1, regarding the carboxyl group concentration, the molecular weight of acrylic acid is 72, the molecular weight of β-carboxyethyl acrylate is 144, and ω-carboxy-polycaprolactone monoacrylate (average degree of polymerization of caprolactone group is about 2). The molecular weight (average molecular weight) was calculated as 276.

  In Table 1, the phosphoric acid group concentration is 456 for the molecular weight (average molecular weight) of mono [poly (propylene oxide) methacrylate] phosphate ester (average degree of polymerization of propylene oxide of about 5.0). (Ethylene oxide) methacrylate] The molecular weight (average molecular weight) of phosphate ester (average degree of polymerization of ethylene oxide of about 5.5) was calculated as 413.5.

Moreover, the numerical value of the undercoat solution (undercoat layer) column in Table 1 indicates the solid content% by weight in the undercoat solution. The numerical value in parenthesis shows solid content ratio.
(Evaluation)
1) Glass adhesion of adhesive optical film
The adhesive optical film of each example and each comparative example was cut to a width of 25 mm, and this was attached to a glass plate (Corning # 1737, manufactured by Corning), and a 2 kg rubber roller was reciprocated once. After pressure bonding, it was left in an autoclave at 50 ° C. and 0.5 MPa for 15 minutes, then cooled to 25 ° C., and 90 ° peel adhesion (peel rate 300 mm / min) was measured (initial adhesive strength).

Further, after being left in an autoclave, it was further left for 40 hours in an atmosphere at 60 ° C., then cooled to 25 ° C., and 90 ° peel adhesion (peeling speed 300 mm / min) was measured. The results are shown in Table 2.
In addition, it shows that glass adhesiveness is so favorable that the value of peeling adhesive force is high.
2) Adhesive fixing property of adhesive optical film The adhesive optical film of each Example and each comparative example was cut into a size of 235 × 310 mm, and this was cut into a 0.7 mm thick glass plate (Corning # 1737, After being left in an autoclave at 50 ° C. and 0.5 MPa for 15 minutes, it was heated in an atmosphere of 90 ° C. and an atmosphere of 60 ° C./90% RH for 500 hours. The presence or absence of peeling of the adhesive optical film was confirmed by visual observation. The results are shown in Table 2.

In addition, the presence or absence of peeling of the adhesive optical film was confirmed according to the following criteria.
○: No change such as peeling was observed Δ: Peeling of less than 1 mm was observed at the edge of the adhesive optical film X: Peeling of 1 mm or more was observed at the edge of the adhesive optical film 3) Water Gel fraction of dispersion-type pressure-sensitive adhesive composition First, a water-dispersed pressure-sensitive adhesive composition (about 100 mg) obtained in each example and each comparative example was first weighed in advance to a Teflon sheet (registered trademark, product number: NTF-1122). ) And octopus yarn (12 cm), and this wrap was weighed. The packet was then placed in a 50 ml glass bottle, and then enough ethyl acetate was added to seal the glass bottle and soaked at room temperature for 7 days. Thereafter, the soaked package was taken out and wiped off the ethyl acetate adhering to the Teflon sheet, and then the package was dried in a dryer at 130 ° C. for 2 hours. Thereafter, the package after drying was weighed. And the gel fraction was computed by the following formula.

Gel fraction (% by weight) = {(C−A) / (B−A)} × 100
The details of the symbols in the formula are as follows.
A (g): Total weight of Teflon sheet and octopus yarn (tare weight)
B (g): Teflon sheet and octopus yarn and water-dispersed pressure-sensitive adhesive composition immersed in ethyl acetate, total weight before drying C (g): Teflon sheet and octopus yarn, water-dispersed pressure-sensitive adhesive composition Table 2 shows the total weight after immersion in ethyl acetate and drying.

It is an expanded sectional view of one embodiment of the adhesion type optical film of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical film 2 Undercoat layer 3 Adhesive layer 4 Release sheet

Claims (8)

An optical film, an adhesive layer laminated on at least one surface of the optical film, and an undercoat layer interposed between the optical film and the adhesive layer,
The pressure-sensitive adhesive layer comprises a pressure-sensitive adhesive composition prepared by polymerizing raw material monomers,
The pressure-sensitive adhesive composition, as a raw material monomer, a number of carbon atoms in the alkyl group is 4 to 18, alkyl group, a linear or branched alkyl and (meth) acrylic acid alkyl esters, unsaturated carboxylic acids and / or Containing a carboxyalkyl acrylate , a phosphate group-containing vinyl monomer represented by the following general formula (1), and an alkoxysilyl group-containing vinyl monomer ,
The blending ratio of the raw material monomers is 60 to 99 parts by weight of the (meth) acrylic acid alkyl ester with respect to 100 parts by weight of the total amount of raw material monomers, and contains the unsaturated carboxylic acid, carboxyalkyl acrylate , and phosphate group. The total amount of the vinyl monomer and the alkoxysilyl group-containing vinyl monomer is 1 to 40 parts by weight,
In the raw material monomers, the unsaturated carboxylic acid and carboxyalkyl acrylate have a carboxyl group concentration of 0.05 to 1.50 mmol / g and a phosphate group concentration of 0.01 to 0.45 mmol / g . ,
The pressure-sensitive adhesive optical film, wherein the undercoat layer contains an oxazoline group-containing polymer.
(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, R ² represents a polyoxyalkylene group represented by the following general formula (2), and X represents the following general formula (3). A phosphoric acid group or a salt thereof.
(In general formula (2), n represents an integer of 1 to 4, and m represents an integer of 2 or more.)
(In General Formula (3), M ¹ and M ² each independently represent a hydrogen atom or a cation.) The mixing ratio of the raw material monomers is 60 to 99 parts by weight of the (meth) acrylic acid alkyl ester and 0.5 to 15 parts by weight of the unsaturated carboxylic acid and carboxyalkyl acrylate with respect to 100 parts by weight of the total amount of raw material monomers. The adhesive optical film according to claim 1, wherein the phosphoric acid group-containing vinyl monomer is 0.5 to 20 parts by weight, and the alkoxysilyl group-containing vinyl monomer is 39 parts by weight or less. The pressure-sensitive adhesive optical film according to claim 1 or 2, wherein the compounding ratio of the alkoxysilyl group-containing vinyl monomer is 0.001 to 1 part by weight with respect to 100 parts by weight of the total amount of raw material monomers. .   The pressure-sensitive adhesive optical film according to claim 1, wherein the pressure-sensitive adhesive composition is a water-dispersed pressure-sensitive adhesive composition. The undercoat layer, characterized in that a mixture of a polymer compound containing a plurality of oxazoline group-containing polymer and mosquitoes carboxyl group, adhesive optical film according to claim 1.   The pressure-sensitive adhesive optical film according to claim 1, wherein the oxazoline group-containing polymer includes a main chain composed of an acrylic skeleton, and includes an oxazoline group in a side chain of the main chain. . Before polymer compound containing a plurality of hear carboxyl group, the number average molecular weight, characterized in that it is 1,000 or more, pressure-sensitive adhesive optical film according to claim 5 or 6.   An image display device using at least one adhesive optical film according to claim 1.