JP2009062264A - Clay mineral water dispersion method, water-dispersed pressure-sensitive adhesive composition, pressure-sensitive adhesive film, pressure-sensitive adhesive optical film, and image display device - Google Patents

Abstract

[PROBLEMS] To disperse a clay mineral in water, which can uniformly disperse a smectite layered clay mineral, and a water-dispersed pressure-sensitive adhesive which is composited with a smectite layered clay mineral with high adhesion reliability and further improved in transparency. Provided are a composition, a pressure-sensitive adhesive film comprising a pressure-sensitive adhesive layer made of the water-dispersed pressure-sensitive adhesive composition, a pressure-sensitive adhesive optical film, and an image display device using the pressure-sensitive adhesive optical film.
A smectite layered clay mineral clay mineral is immersed in water at 35 ° C. or lower for 24 hours or more, and then a phosphate dispersant or polycarboxylate dispersant is blended in water, and then dispersed by a dispersing device. A clay mineral is dispersed in water at 0 to 35 ° C. to obtain an aqueous dispersion of clay mineral. The water dispersion of the clay mineral and the water dispersion of the water dispersion polymer are blended to obtain a water dispersion pressure-sensitive adhesive composition. This is laminated | stacked on the single side | surface of the optical film 1, the adhesive layer 2 is formed, and an adhesive optical film is obtained.
[Selection] Figure 1

Description

  The present invention relates to an aqueous dispersion method of a clay mineral, an aqueous dispersion pressure-sensitive adhesive composition, an adhesive film, an adhesive optical film, and an image display device.

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 this application, a solvent-type pressure-sensitive adhesive produced using an organic solvent is used.

On the other hand, in recent years, from the viewpoint of reducing environmental impact, it has been desired to reduce the use of organic solvents, and conversion from a solvent-based adhesive to a water-dispersed adhesive that uses water as a dispersion medium is desired. Yes.
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 1).

  However, the conventional water-dispersed pressure-sensitive adhesives including Patent Document 1 as described above have improved adhesion to hydrophobic adherends such as polyolefins, but have particularly good adhesion to hydrophilic adherends such as glass. There is a problem that it is low and inferior in adhesion to a glass substrate such as a liquid crystal display. In the field of optical films, application of water-dispersed pressure-sensitive adhesives is generally difficult because high heat resistance and moisture resistance are required so that adhesion and the like are not reduced by severe heating or humidification. .

Examples of water-dispersed pressure-sensitive adhesives that have been applied to this field include water-dispersed adhesives obtained by emulsion polymerization of butyl acrylate, acrylic acid, phosphate group-containing monomers and 3-methacryloyloxypropyltrimethoxysilane. An acrylic pressure-sensitive adhesive composition has been proposed (see, for example, Patent Document 2).
Also, an aqueous dispersion of an acrylic copolymer obtained by emulsion polymerization of butyl acrylate, acrylic acid, and 3-methacryloyloxypropyltrimethoxysilane, and a smectite layered clay treated with a quaternary ammonium salt A water-dispersed acrylic pressure-sensitive adhesive composition obtained by mixing with a mineral aqueous dispersion has been proposed (for example, see Patent Document 3).
JP 2001-254063 A JP 2007-186661 A JP 2006-316085 A

  These water-dispersed pressure-sensitive adhesives proposed in Patent Documents 2 and 3 exhibit adhesive performance suitable for optical film applications. In particular, the composite water-dispersed pressure-sensitive adhesive disclosed in Patent Document 3 has a higher adhesive reliability such as heat-resistant adhesion, and can be applied to applications used under more severe conditions. However, smectite layered clay minerals treated with quaternary ammonium salts have low hydrophilicity and are difficult to disperse in water. Therefore, there is a limit to miniaturization of the dispersed particle diameter, and the transparency of the composite pressure-sensitive adhesive prepared by mixing with an acrylic copolymer aqueous dispersion is also limited. Moreover, the transparency (haze) of the water-dispersed acrylic pressure-sensitive adhesive composition of Patent Document 3 has sufficient transparency when the thickness is 20 μm, but the transparency may decrease as the thickness increases. In addition, there is a problem that it is difficult to apply to an application of an optical pressure-sensitive adhesive for laminating and bonding an optical film (for example, a use of laminating and bonding a polarizing plate and a retardation plate).

  An object of the present invention is to provide a clay mineral water dispersion method capable of uniformly dispersing a smectite-based layered clay mineral, a composite with a smectite-based layered clay mineral with high adhesion reliability, and water dispersion with further improved transparency. Another object is to provide a pressure-sensitive adhesive composition, a pressure-sensitive adhesive film having a pressure-sensitive adhesive layer made of the water-dispersed pressure-sensitive adhesive composition, a pressure-sensitive adhesive optical film, and an image display device using the pressure-sensitive adhesive optical film.

As a result of earnest research to achieve the above purpose, the dispersion conditions of clay minerals are related to the transparency (haze) of the composite water-dispersed pressure-sensitive adhesive. In particular, 1) Immersion of clay minerals in water It was found that the time, 2) the water temperature of the dipping step and the post-dispersing step, and 3) the timing of addition of the phosphate dispersant or polycarboxylate dispersant were important.
Specifically, the water dispersion method of the clay mineral according to the present invention includes a dipping step of immersing a smectite-based layered clay mineral that has been organically treated with a quaternary ammonium salt in water at 35 ° C. or lower for 24 hours or more, and the dipping step. After that, a phosphate-based dispersant or a polycarboxylate-based dispersant is added to the water, and then the clay mineral is dispersed in the water at 0 to 35 ° C. by a dispersing device; It is characterized by having.

Moreover, in the water dispersion method of the clay mineral of the present invention, it is preferable to further include a pre-dispersion step of dispersing the smectite-based layered clay mineral in water at 0 to 20 ° C. before the soaking step.
In the clay mineral water dispersion method of the present invention, it is preferable that the content ratio of the clay mineral is 5 to 20 parts by weight with respect to 100 parts by weight of the water in the post-dispersion step.

In the clay mineral water dispersion method of the present invention, in the post-dispersion step, the blending ratio of the phosphate dispersant or the polycarboxylate dispersant is 1 with respect to 100 parts by weight of the clay mineral. It is preferable that it is -40 weight part.
In the water dispersion method of a clay mineral according to the present invention, it is preferable that the clay mineral has a smectite layered clay mineral that is organically treated with a quaternary ammonium salt having a hydroxyl group.

The water-dispersed pressure-sensitive adhesive composition of the present invention is obtained by adding 100 parts by weight of the water-dispersed polymer and the water-dispersed clay mineral obtained by the above-described clay-mineral water-dispersing method. The clay mineral is blended so as to be 1 to 20 parts by weight.
The water-dispersed pressure-sensitive adhesive composition of the present invention has a haze value of 3% or less and a total light transmittance when molded into a sheet having a thickness of 200 μm when the above dispersion conditions and composition conditions are satisfied. It is preferable to be 90 to 100%.

Moreover, the adhesive film of this invention is equipped with the support body and the adhesive layer which consists of said water dispersion type adhesive composition laminated | stacked on the at least single side | surface of the said support body, It is characterized by the above-mentioned.
The pressure-sensitive adhesive optical film of the present invention is the above-described pressure-sensitive adhesive film, wherein the support is an optical film.
The image display device of the present invention is characterized by using at least one of the above-mentioned adhesive optical films.

  According to the water dispersion method of a clay mineral of the present invention, the transparency of a water-dispersed pressure-sensitive adhesive composition composited with a smectite layered clay mineral having high adhesion reliability can be further improved. Therefore, it is possible to provide a pressure-sensitive adhesive film, a pressure-sensitive adhesive optical film, and an image display device using the pressure-sensitive adhesive optical film having more excellent optical characteristics.

The clay mineral water dispersion method of the present invention includes a dipping step in which the clay mineral is immersed in water at 35 ° C. or lower for 24 hours or more, and after the dipping step, the phosphate dispersant or the polycarboxylate dispersant is added to the water. And then a post-dispersing step of dispersing the clay mineral in water at 0 to 35 ° C. with a dispersing device.
Examples of the clay mineral include smectite, that is, a phyllosilicate mineral which is a montmorillonite group mineral and has a layered structure. Examples of smectites include montmorillonite, magnesia montmorillonite, tetsu montmorillonite, tectum magnesia montmorillonite, beidellite, aluminian beidellite, nontronite, aluminian nontronite, saponite (saponite), and aluminian support. Stones, hectorites, soconites, steven sites, etc. These clay minerals can be used alone or in combination of two or more.

The clay mineral is organically treated with a quaternary ammonium salt. Here, the organic treatment means that the interlayer cations of the clay mineral ion exchange with the quaternary ammonium salt.
The cation of the clay mineral is, for example, a metal cation such as sodium ion or calcium ion.
The quaternary ammonium salt includes a cation in which a hydrogen atom of an ammonium ion (NH ⁴⁺ ) is substituted with a propylene oxide skeleton, an ethylene oxide skeleton, an alkyl skeleton, a halide ion (for example, a chloride ion), or the like. A salt with an anion is mentioned.

The quaternary ammonium salt is more preferably one having a hydrophilic functional group such as a hydroxyl group at the terminal, specifically, one having a propylene oxide skeleton having a hydroxyl group at the terminal. Quaternary ammonium salts can be used alone or in combination of two or more.
As the clay mineral that has been organically treated with a quaternary ammonium salt, a general commercially available product is generally used, for example, the Lucentite series (manufactured by Co-op Chemical), and more specifically, Lucentite SPN, Lucene. Examples include Tight SAN, Lucentite SEN, and Lucentite STN.

The amount of the organic treatment in the clay mineral is not particularly limited and is, for example, 80 to 240 mol eq. / 100g.
The phosphate dispersant is blended in order to obtain dispersion stability of the clay mineral in water (for dispersion stabilization). Since the phosphate dispersant is adsorbed on the particle surface of the clay mineral, it is considered that dispersion stability can be obtained by the electrostatic repulsive force based on the negative charge of the phosphate.

  Specific examples of the phosphate dispersant include sodium orthophosphate, sodium pyrophosphate (sodium diphosphate), sodium tripolyphosphate (sodium triphosphate), sodium tetraphosphate, sodium hexametaphosphate, sodium polyphosphate, Examples thereof include trisodium phosphate and sodium dihydrogen phosphate. Preferably, sodium pyrophosphate, sodium tripolyphosphate, and sodium hexametaphosphate are used.

The polycarboxylate-based dispersant is blended in order to obtain dispersion stability of the clay mineral in water (for dispersion stabilization). Since the polycarboxylate-based dispersant is adsorbed on the particle surface of the clay mineral, it is considered that dispersion stability can be obtained by the electrostatic repulsive force based on the negative charge of the polycarboxylate (carboxylate).
Examples of the polycarboxylate-based dispersant include a polymer of a carboxylate salt of an inorganic cation (metal cation) such as sodium or an organic cation such as ammonium and a carboxylic acid, and poly (meth) acrylic acid Salts (ie, polyacrylates and / or polymethacrylates), poly (meth) acrylate / maleate copolymers, and the like. Specific examples of the polycarboxylate-based dispersant include sodium polycarboxylates such as sodium poly (meth) acrylate and sodium (meth) acrylate / sodium maleate copolymers, such as poly (meta ) Ammonium acrylate, ammonium polycarboxylate such as ammonium (meth) acrylate / ammonium maleate copolymer, and the like. Preferably, sodium polycarboxylate is used.

In the water dispersion method for a clay mineral of the present invention, first, the clay mineral is immersed in water in the immersion step. You may stir with a stirrer etc. during immersion.
The blending ratio of the clay mineral in the dipping process is, for example, 1 to 30 parts by weight, preferably 5 to 20 parts by weight with respect to 100 parts by weight of water.
The water temperature is set to 35 ° C. or lower, preferably 30 ° C. or lower, and is usually set to 10 ° C. or higher. When the water temperature exceeds 35 ° C., the clay mineral is phase-separated from water in the dipping step, so that the clay mineral cannot be sufficiently swollen, and the clay mineral is sufficiently uniformly dispersed in the subsequent post-dispersion step. I can't.

Moreover, water temperature can also be set to 0-10 degreeC, for example, and water can also be cooled (low temperature preservation).
The immersion time is set to 24 hours or more, preferably 72 hours or more, usually 168 hours (7 days) or less, although it depends on the immersion temperature and the presence or absence of stirring. In addition, when stirring as mentioned above or preserve | saved at low temperature, immersion time can also be made into 24-48 hours, for example. When the immersion time is less than the above range, the clay mineral cannot sufficiently swell (water sufficiently permeates), and the clay mineral cannot be dispersed sufficiently uniformly.

This immersion step can facilitate the dispersion of the clay mineral in the subsequent post-dispersion step.
Next, a phosphate-based dispersant or a polycarboxylate-based dispersant is added to water in which the clay mineral is immersed (water immersion liquid of the clay mineral) to disperse the clay mineral (post-dispersing step).
It is important that the timing (timing) in which the phosphate dispersant or the polycarboxylate dispersant is added is during the post-dispersing step, that is, after the dipping step. On the other hand, when a phosphate-based dispersant or a polycarboxylate-based dispersant is added during or before the dipping process, swelling of the clay mineral is inhibited.

  The mixing ratio of the phosphate dispersant is, for example, 1 to 40 parts by weight, preferably 1 to 20 parts by weight, and more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the clay mineral. The blending ratio of the polycarboxylate-based dispersant is, for example, 1 to 40 parts by weight, preferably 10 to 40 parts by weight, and more preferably 20 to 30 parts by weight with respect to 100 parts by weight of the clay mineral. If the blending ratio of phosphate dispersant and polycarboxylate dispersant is less than the above range, dispersion stabilization of clay mineral particles by phosphate dispersant or polycarboxylate dispersant The effect becomes low, and a fine dispersion state of the clay mineral particles may not be obtained, or aggregation may be caused in mixing with the water-dispersed polymer. On the other hand, when the blending ratio of the phosphate-based dispersant or the polycarboxylate-based dispersant exceeds the above range, the ionic strength of the aqueous dispersion becomes high and salting out may occur.

Next, in the post-dispersing step, the clay mineral is dispersed at 0 to 35 ° C. with respect to water by a dispersing device.
The content ratio of the clay mineral in the post-dispersion step is set to, for example, 5 to 20 parts by weight, preferably 5 to 10 parts by weight with respect to 100 parts by weight of water.
The temperature (water temperature) at the time of dispersion of the clay mineral in the post-dispersion step is set to 0 to 35 ° C, preferably 0 to 30 ° C, and more preferably 0 to 20 ° C. When the temperature at the time of dispersion of the clay mineral in the post-dispersion step exceeds the above range, the clay mineral may cause a phase separation with water as in the dipping step, which is not preferable.

The dispersion device is not particularly limited as long as the above dispersion condition can be satisfied. For example, a homomixer, a disper, an ultrasonic disperser and the like are preferably used.
In the case of using a homomixer and / or a disper as the dispersing device, as the dispersion condition, for example, the peripheral speed of the dispersing device is set to 400 m / s or more, preferably 800 m / s or more, usually 2000 m / s. Set to s or less. If it is less than the above range, dispersion may be insufficient.

The clay mineral usually has a plate-like structure in which multiple silicate layers are overlapped. When the average particle diameter of the clay mineral is preferably 200 nm or less, more preferably 100 nm or less, The dispersion process is terminated. If the post-dispersion step is terminated when the average particle diameter exceeds 200 nm, the transparency may be lowered.
As described above, the important points in the water dispersion method of this clay mineral are 1) the immersion time of the clay mineral in water, 2) the water temperature of the dipping process and the post-dispersing process, 3) the phosphate-based dispersant or the poly This is the time when the carboxylate-based dispersant is added, and can be considered as follows.

1) Regarding the immersion time of clay minerals in water, since clay minerals treated with quaternary ammonium salts have low hydrophilicity, it is necessary to allow time for water to sufficiently wet the particle surface and penetrate between layers. It is done. It is considered that dispersion is facilitated when water sufficiently permeates between layers.
2) Regarding the water temperature in the dipping process and the post-dispersing process, clay minerals treated with a quaternary ammonium salt tend to separate from water when the water temperature is high. A state cannot be obtained. It is considered that the reason why the layers are separated at high temperature is that the hydrophilicity of the organic treatment agent (quaternary ammonium salt) further decreases at high temperature.

  3) Regarding the timing of addition of the phosphate dispersant or polycarboxylate dispersant, the phosphate dispersant and polycarboxylate when the clay mineral treated with quaternary ammonium salt is immersed in water. The point is that no dispersant is added. Phosphate-based dispersants or polycarboxylate-based dispersants tend to inhibit the immersion of water between layers of clay minerals, resulting in a decrease in dispersion state (dispersion stability). The immersion of water between layers is driven by the osmotic pressure due to the difference in ionic concentration between water and the layer, so the addition of a phosphate dispersant or polycarboxylate dispersant increases the ion concentration in water ( Therefore, it is considered that the osmotic pressure is lowered and the immersion of water between layers is hindered.

In addition, the above-described clay mineral water dispersion method may further include a pre-dispersion step of dispersing the smectite layered clay mineral in water before the dipping step.
That is, in the pre-dispersion step, first, the same smectite layered clay mineral as described above is blended in water, and then the smectite layered clay mineral is dispersed in water.
The temperature (water temperature) at the time of dispersion of the clay mineral in the pre-dispersion step is set to, for example, 0 to 20 ° C, preferably 7 to 20 ° C. When the temperature at the time of dispersion | distribution of the clay mineral in a pre-dispersion process exceeds the said range, there exists a possibility that a clay mineral may aggregate.

Moreover, the dispersion time in a pre-dispersion process is 5 to 30 minutes, for example, Preferably, it is 10 to 20 minutes.
By carrying out the pre-dispersing step, the swelling of the clay mineral into water can be promoted.
In particular, the pre-dispersion step is preferably performed when a polycarboxylate-based dispersant is blended as a dispersant in the post-dispersion step.

Next, the water-dispersed pressure-sensitive adhesive composition of the present invention, in which a water-dispersed polymer and a clay mineral water dispersion obtained by the above-described clay mineral water dispersion method are blended, will be described.
This water-dispersed pressure-sensitive adhesive composition contains a water-dispersed polymer and an aqueous dispersion of clay mineral.
Examples of the water-dispersed polymer include water-dispersed acrylic polymers, and examples of such water-dispersed acrylic polymers include (meth) acrylic acid alkyl ester as a main component, and As other components, a reactive functional group-containing vinyl monomer having a reactive functional group, a copolymerizable vinyl monomer copolymerizable with the above monomers ((meth) acrylic acid alkyl ester and reactive functional group-containing vinyl monomer), and Can be obtained by copolymerizing a vinyl monomer mixture containing.

  The (meth) acrylic acid alkyl ester is a methacrylic acid alkyl ester and / or an acrylic acid alkyl ester, and is represented by, for example, the following general formula (1).

(In the general formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a linear or branched alkyl group having 1 to 18 carbon atoms.)
Examples of R ² include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, sec-butyl group, t-butyl group, pentyl group, neopentyl group, isopentyl group, hexyl group, and heptyl group. Octyl group, 2-ethylhexyl group, isooctyl group, nonyl group, isononyl group, decyl group, isodecyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, etc. Is mentioned.

  Specific examples of (meth) acrylic acid alkyl esters include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and (meth) acrylic acid. Butyl, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, neopentyl (meth) acrylate, isopentyl (meth) acrylate, (meta ) Hexyl acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, (meth) acrylic acid Isononyl, decyl (meth) acrylate, isodecyl (meth) acrylate, (meth) acrylic Undecyl sulfate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, (meth) acrylic Examples include alkyl (meth) acrylate (linear or branched alkyl having 1 to 18 carbon atoms) ester such as octadecyl acid. These alkyl (meth) acrylates can be used alone or in combination of two or more.

The mixing ratio of the (meth) acrylic acid alkyl ester is 60 to 99.5 parts by weight, preferably 80 to 99 parts by weight, with respect to 100 parts by weight of the vinyl monomer mixture.
Examples of the reactive functional group contained in the reactive functional group-containing vinyl monomer include a carboxyl group, an epoxy group, a hydroxyl group, an amide group, an amino group, a cyano group, an imide group, a sulfonic acid group, and an isocyanate group. . Preferably, a carboxyl group is mentioned.

  As the reactive functional group-containing vinyl monomer, specifically, as a carboxyl group-containing vinyl monomer, for example, unsaturated carboxylic acid such as (meth) acrylic acid, fumaric acid, maleic acid, itaconic acid, crotonic acid, cinnamic acid, etc. Acids, for example, unsaturated dicarboxylic acid anhydrides such as fumaric anhydride, maleic anhydride, itaconic anhydride, for example, unsaturated dicarboxylic acid monoesters such as monomethyl itaconic acid, monobutyl itaconic acid, 2-acryloyloxyethylphthalic acid, Examples thereof include unsaturated tricarboxylic acid monoesters such as 2-methacryloyloxyethyl trimellitic acid and 2-methacryloyloxyethyl pyromellitic acid, and carboxyalkyl acrylates such as carboxyethyl acrylate and carboxypentyl acrylate.

  As the reactive functional group-containing vinyl monomer, in addition to the above-mentioned carboxyl group-containing vinyl monomer, for example, epoxy group-containing vinyl monomers such as glycidyl (meth) acrylate and methyl glycidyl (meth) acrylate, for example, acrylic Hydroxyl group-containing vinyl monomers such as 2-hydroxyethyl acid, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, ethylene glycol (meth) acrylate, propylene glycol (meth) acrylate, such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-methylol Amide group-containing vinyl monomers such as (meth) acrylamide, N-methylolpropane (meth) acrylamide, N-vinylcarboxylic acid amide, for example, dimethylaminoethyl (meth) acrylate, t-butylaminoethyl (meth) acrylate, etc. Amino group-containing vinyl monomers, for example, cyano group-containing vinyl monomers such as acrylonitrile and methacrylonitrile, for example, maleimide-based imide groups such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide Vinyl monomers, for example, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitacimide Itacimide-based imide group vinyl-containing monomers such as imide and N-laurylitaconimide, such as N- (meth) acryloyloxymethylene succinimide, N- (meth) acryloyl-6-oxyhexamethylene succinimide, N- (meth) acryloyl Succinimide-based imide group-containing vinyl monomers such as -8-oxyoctamethylene succinimide, such as styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, Sulfonic acid group-containing vinyl monomers such as sulfopropyl (meth) acrylate and (meth) acryloyloxynaphthalenesulfonic acid, for example, isocyanates such as 2-methacryloyloxyethyl isocyanate Group-containing vinyl monomers.

Of these reactive functional group-containing vinyl monomers, a carboxyl group-containing vinyl monomer is preferable.
The mixing ratio of the reactive functional group-containing vinyl monomer is, for example, 0.5 to 15 parts by weight, preferably 0.5 to 10 parts by weight with respect to 100 parts by weight of the vinyl monomer mixture.
Examples of the copolymerizable vinyl monomer include vinyl esters such as vinyl acetate and vinyl propionate, and olefinic monomers such as ethylene, propylene, isoprene, butadiene, and isobutylene, such as cyclohexyl (meth) acrylate, (meta ) Cyclopentyl acrylate, (meth) acrylic acid bornyl, (meth) acrylic acid alicyclic hydrocarbon esters such as isobornyl (meth) acrylate, for example, (meth) acrylic acid aryl esters such as phenyl (meth) acrylate, For example, aromatic vinyl monomers such as styrene and vinyltoluene such as (meth) acryloylmorpholine, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, and (meth) acrylic acid t- Butylaminoethyl Nitrogen atom-containing vinyl monomers such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxyethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, etc. For example, vinyl ether monomers such as vinyl ether, halogen atom-containing monomers such as vinyl chloride, such as N-vinylpyrrolidone, N- (1-methylvinyl) pyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinyl Contains vinyl groups such as pyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-vinylmorpholine, tetrahydrofurfuryl (meth) acrylate Heterocyclic compounds, for example, acrylic acid ester monomer containing a halogen atom.

Moreover, a polyfunctional monomer is mentioned as a copolymerizable 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. , Neopentyl glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, pentaerythritol di (meth) acrylate, tetramethylolmethane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc. Mono or poly) alkylene polyol poly (meth) acrylate, divinylbenzene and the like. Examples of the polyfunctional monomer include epoxy acrylate, polyester acrylate, and urethane acrylate.

Furthermore, examples of the copolymerizable vinyl monomer include alkoxysilyl group-containing vinyl monomers.
Examples of the alkoxysilyl group-containing vinyl monomer include silicone (meth) acrylate monomers and silicone 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, 3- (meth) acryloyloxypropyl-tributoxysilane, 10- (meth) acryloyloxydecyl-trimethoxysilane, 10- (meth) a (Meth) acryloyloxyalkyl-trialkoxysilanes such as liloyloxydecyl-triethoxysilane, such as (meth) acryloyloxymethyl-methyldimethoxysilane, (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-methyldi Toxisilane, 3- (meth) acryloyloxypropyl-ethyldimethoxysilane, 3- (meth) acryloyloxypropyl-ethyldiethoxysilane, 3- (meth) acryloyloxypropyl-ethyldipropoxysilane, 3- (meth) acryloyloxy Such as propyl-ethyldiisopropoxysilane, 3- (meth) acryloyloxypropyl-ethyldibutoxysilane, 3- (meth) acryloyloxypropyl-propyldimethoxysilane, 3- (meth) acryloyloxypropyl-propyldiethoxysilane (Meth) acryloyloxyalkyl, such as (meth) acryloyloxyalkyl-alkyldialkoxysilane and the corresponding (meth) acryloyloxyalkyl-dialkyl (mono) alkoxysilane A kill silane derivative is mentioned.

  Examples of silicone-based vinyl monomers include vinyltrialkoxysilanes such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, and vinyltributoxysilane, and vinylalkyldisilanes corresponding to these. Alkoxysilanes and vinyldialkylalkoxysilanes such as vinylmethyltrimethoxysilane, vinylmethyltriethoxysilane, β-vinylethyltrimethoxysilane, β-vinylethyltriethoxysilane, γ-vinylpropyltrimethoxysilane, γ-vinylpropyl Triethoxysilane, γ-vinylpropyltripropoxysilane, γ-vinylpropyltriisopropoxysilane, γ-vinylpropyltributoxysilane, 4-vinylbutyltrime Vinylalkyltrialkoxysilanes such as xylsilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, and the corresponding (vinylalkyl) alkyldialkoxysilanes and (vinyl Alkyl) dialkyl (mono) alkoxysilane and the like.

These copolymerizable vinyl monomers can be used alone or in combination of two or more.
Of these copolymerizable vinyl monomers, an alkoxysilyl group-containing vinyl monomer is preferable. By using an alkoxysilyl group-containing vinyl monomer, an alkoxysilyl group is introduced into the copolymer, and a uniform cross-linked structure can be formed by a reaction between them.

The blending ratio of the copolymerizable vinyl monomer is, for example, 39.5 parts by weight or less, preferably 19 parts by weight or less with respect to 100 parts by weight of the vinyl monomer mixture.
When an alkoxysilyl group-containing vinyl monomer is blended as the copolymerizable vinyl monomer, the blending ratio is, for example, 0.001 to 1 part by weight with respect to 100 parts by weight of the vinyl monomer mixture, preferably 0. 01 to 0.1 parts by weight.

The water-dispersed polymer can be obtained by copolymerizing the above vinyl monomer mixture.
In order to copolymerize the above vinyl monomer mixture, for example, a known polymerization method such as emulsion polymerization is used.
In emulsion polymerization, for example, an emulsifier, a polymerization initiator, and, if necessary, a chain transfer agent are appropriately blended in water together with the above-described vinyl monomer mixture and copolymerized. More specifically, for example, a known emulsion polymerization method such as a batch charging method (batch polymerization method), a monomer dropping method, a monomer emulsion dropping method, or a combination thereof can be employed. In the monomer dropping method and the monomer emulsion dropping method, continuous dropping or divided dropping is appropriately selected. Although reaction conditions etc. are suitably selected according to the kind of polymerization initiator, etc., superposition | polymerization temperature is 20-90 degreeC, for example.

  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.

Moreover, radically polymerizable (reactive) emulsifiers (for example, Aqualon HS-10) in which radically polymerizable functional groups (radical reactive groups) such as propenyl groups and allyl ether groups are introduced into these anionic and nonionic emulsifiers. And Daiichi Kogyo Seiyaku Co., Ltd.).
These emulsifiers can be used alone or in combination of two or more.
The blending ratio of the emulsifier is, for example, about 0.2 to 10 parts by weight, preferably about 0.5 to 5 parts by weight with respect to 100 parts by weight of the vinyl monomer mixture.

  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 '-Dimethyleneisobutylamidine), 2,2'-azobis (N, N'-dimethyleneisobutylamidine) dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] Azo initiators such as hydrochloride, for example, persulfate initiators such as potassium persulfate and ammonium persulfate such as benzoyl peroxide, t-butyl hydroperoxide, Peroxide-based initiators such as hydrogen fluoride, for example, substituted ethane-based initiators such as phenyl-substituted ethane, for example, carbonyl-based initiators such as aromatic carbonyl compounds, for example, a combination of persulfate and sodium bisulfite, Redox initiators (combination of peroxide and reducing agent) such as a combination of peroxide and sodium ascorbate.

The polymerization initiator may be either water-soluble or oil-soluble, and these polymerization initiators can be used alone or in combination of two or more.
The mixing ratio of the polymerization initiator is, for example, 0.005 to 1 part by weight with respect to 100 parts by weight of the vinyl monomer mixture.
Note that the dissolved oxygen concentration in the vinyl monomer mixture may be reduced by nitrogen substitution before or while the polymerization initiator is blended with the vinyl monomer mixture.

The chain transfer agent is blended as necessary and adjusts the molecular weight of the water-dispersed polymer, 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 can be used alone or in combination of two or more.

The mixing ratio of the chain transfer agent is, for example, 0.001 to 0.5 parts by weight with respect to 100 parts by weight of the vinyl monomer mixture.
By such emulsion polymerization, the obtained water-dispersed polymer can be prepared as an emulsion (water dispersion).
In addition, the aqueous dispersion of the water-dispersed polymer is obtained by polymerizing the above-described vinyl monomer mixture by a method that does not use an organic solvent other than emulsion polymerization (for example, suspension polymerization, etc.), and then, if necessary, It is also possible to prepare with an emulsifier.

Moreover, the average particle diameter of the emulsion particle | grains of a water dispersion type polymer is 0.05-10 micrometers, for example, Preferably, it is 0.1-1 micrometer.
The solid content concentration of the aqueous dispersion of the prepared water-dispersed polymer is, for example, 10 to 80% by weight, preferably 20 to 60% by weight.
And in order to obtain the water dispersion-type adhesive composition of this invention, the water dispersion liquid of a water dispersion type polymer and the water dispersion liquid of a clay mineral are mix | blended.

  The mixing ratio of the aqueous dispersion of the water-dispersed polymer and the aqueous dispersion of the clay mineral is such that the clay mineral is 100 parts by weight of the solid content of the aqueous dispersion of the water-dispersed polymer (water-dispersed polymer). The solid content (clay mineral) of the aqueous dispersion is 1 to 20 parts by weight, preferably 5 to 15 parts by weight. When it exceeds the above range, the transparency is lowered. On the other hand, when it is less than the above range, the effect of improving excellent adhesiveness (adhesion reliability) under a severe atmosphere such as a high temperature atmosphere or a high temperature and high humidity atmosphere cannot be obtained.

In the water-dispersed pressure-sensitive adhesive composition thus obtained, if necessary, a crosslinking agent, a viscosity modifier, a release modifier, a plasticizer, a softener, a filler, a colorant (pigment, dye, etc.), Additives usually added to the water-dispersed pressure-sensitive adhesive composition such as an anti-aging agent and a surfactant may be added at an appropriate ratio.
Furthermore, this water-dispersed pressure-sensitive adhesive composition is adjusted to, for example, pH 7 to 9, preferably pH 7 to 8, for example, with ammonia water for the purpose of improving the stability of the emulsion.

The water-dispersed pressure-sensitive adhesive composition thus obtained has a haze value of, for example, 3% or less, preferably 2% or less when formed into a sheet having a thickness of 200 μm, and the total light transmittance is For example, it is 90 to 100%, preferably 92 to 100%.
The haze value is the ratio of the scattered light to the transmitted light when the transmitted light (parallel light) incident from the light source passes through the sheet-like water-dispersed pressure-sensitive adhesive composition and scatters. ).

Haze value (%) = (scattered light amount) / (total transmitted light amount) × 100 (2)
When the haze value is within the above range, a water-dispersed pressure-sensitive adhesive composition with better transparency can be obtained. On the other hand, when the haze value exceeds the above range, the scattered light may increase and appear cloudy.
The haze value is measured with a haze meter (“NDH2000” manufactured by Nippon Denshoku Industries Co., Ltd. or “HM-150 type” manufactured by Murakami Color Research Laboratory Co., Ltd.) in accordance with JIS K7136.

The total light transmittance is the ratio of the transmitted light to the incident light when the light incident from the light source (incident light) is transmitted through the sheet-like water-dispersed pressure-sensitive adhesive composition. Indicated.
Total light transmittance (%) = (transmitted light amount) / (incident light amount) × 100 (3)
When the total light transmittance is less than the above range, the optical characteristics may be deteriorated.
In order to form the water-dispersed pressure-sensitive adhesive composition into a sheet, the water-dispersed pressure-sensitive adhesive composition is applied to a glass plate and dried at, for example, 80 to 130 ° C.

The total light transmittance is measured by a haze meter (Nippon Denshoku Industries Co., Ltd., “NDH2000” or Murakami Color Research Laboratory Co., Ltd. “HM-150”) in accordance with JIS K7361-1.
In the water-dispersed pressure-sensitive adhesive composition of the present invention thus obtained, the clay mineral is finely and uniformly dispersed in the water-dispersed pressure-sensitive adhesive composition. Therefore, if the water-dispersed pressure-sensitive adhesive composition is formed as a pressure-sensitive adhesive layer, high adhesion reliability (especially high moist heat resistance and high heat resistance) can be obtained while ensuring excellent transparency.

Next, the manufacturing method of one Embodiment of the adhesive optical film (adhesive film) of this invention is demonstrated with reference to FIG.
To obtain an adhesive optical film, first, an optical film 1 as a support is prepared.
The optical film 1 is not particularly limited, 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.

And the adhesive layer 2 which consists of a water dispersion-type adhesive composition is provided in the single side | surface of the optical film 1. FIG.
In order to provide the pressure-sensitive adhesive layer 2, for example, a method of transferring the pressure-sensitive adhesive layer 2 from the release sheet 3 on which the pressure-sensitive adhesive layer 2 is formed to the optical film 1 described above can be mentioned. The release sheet 3 on which the pressure-sensitive adhesive layer 2 is formed is prepared by directly coating the release sheet 3 with a water-dispersed pressure-sensitive adhesive composition by a known coating method such as a knife coating method, and drying it. be able to. In order to transfer the pressure-sensitive adhesive layer 2, the pressure-sensitive adhesive layer 2 on which the release sheet 3 is formed is bonded to the optical film 1, and then the release sheet 3 is peeled off from the pressure-sensitive adhesive layer 2.

In order to provide the pressure-sensitive adhesive layer 2, for example, the optical film 1 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.
Examples of the release sheet 3 include 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. The surface of the release sheet 3 may be subjected to treatments such as silicone treatment, long-chain alkyl treatment, and fluorine treatment as necessary in order to improve the peelability from the pressure-sensitive adhesive layer 2.

The thickness (thickness after drying) of the pressure-sensitive adhesive layer 2 is set to, for example, 1 to 500 μm, preferably 5 to 200 μm.
Although not shown, an undercoat layer is provided in advance on the surface of the optical film 1 (the surface on the side where the pressure-sensitive adhesive layer 2 is formed) in order to improve the adhesive force (throwing force) with the pressure-sensitive adhesive layer 2. Undercoating can be applied.

Thus, an adhesive optical film can be obtained by providing the adhesive layer 2 made of the water-dispersed adhesive composition on one surface of the optical film 1.
The pressure-sensitive adhesive optical film obtained in this way has a pressure-sensitive adhesive layer made of a water-dispersed pressure-sensitive adhesive composition that ensures excellent transparency, so that excellent optical properties are obtained without depending on the thickness of the pressure-sensitive adhesive layer. Characteristics can be obtained. In addition, excellent optical characteristics can be obtained even in a product in which an optical film is laminated and adhered in several layers (for example, a product having a configuration such as a polarizing plate / adhesive layer / retardation plate / adhesive layer). . Furthermore, since it has high adhesion reliability in the adhesion of the liquid crystal display to the glass substrate, it is suitably used for optical applications.

In the above description, the pressure-sensitive adhesive layer 2 is provided on one side of the optical film 1, but can also be provided on both sides of the optical film 1.
In the above description, the adhesive film of the present invention has been described as the adhesive optical film of the present invention including an optical film as a support. For example, an adhesive sheet including a sheet as a support or a tape as a support. It is also used as an adhesive optical tape provided.

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 water-dispersed polymer)
To the container, 100 parts of butyl acrylate, 5 parts of acrylic acid, and 0.015 part of 3-methacryloyloxypropyl-trimethoxysilane (KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd.) were added and mixed to prepare a vinyl monomer mixture. Next, 13 g of Aqualon HS-10 (Daiichi Kogyo Seiyaku Co., Ltd.) and 360 g of ion-exchanged water are added as reactive emulsifiers to 627 g of the prepared vinyl monomer mixture, and for 5 minutes using a homomixer (made by Tokushu Kika Co., Ltd.). A monomer pre-emulsion was prepared by stirring and forcibly emulsifying at 6000 (1 / min).

Subsequently, 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, 0.2 g of 2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (VA-057, manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was stirred at 60 ° C. Polymerized for 1 hour. Next, 800 g of the remaining monomer pre-emulsion was dropped into the reaction vessel over 3 hours while maintaining the reaction vessel at 60 ° C., and then polymerized for 3 hours to obtain a water-dispersed polymer having a solid content of 48%. An aqueous dispersion was obtained. Subsequently, this was cooled to room temperature and 10% aqueous ammonia was added to adjust the pH to 8.
(Preparation of aqueous dispersion of clay mineral)
90 parts of ion-exchanged water, Lucentite SPN (Smectite treated with a quaternary ammonium salt having a propylene oxide skeleton having a hydroxyl group at the end and subjected to a hydrophobization treatment in an amount of 120 mol eq./100 g, manufactured by Coop Chemical Co., Ltd.) 10 Part was added and immersed for 4 days (96 hours) at 23 ° C. in a stationary state to swell Lucentite SPN in water (immersion step).

  Thereafter, sodium hexametaphosphate (phosphate dispersant, manufactured by Kishida Chemical Co., Ltd.) was added at a ratio of 10 parts to 100 parts of Lucentite SPN and dissolved. Next, using a homomixer (manufactured by Tokushu Kika Co., Ltd.), the aqueous solution in which the Lucentite SPN was immersed was cooled in an ice-water bath to remove heat and 10000 (1 / min) (= peripheral speed 1100 m / min) for 15 minutes. The mixture was stirred and dispersed in s) (post-dispersion step). The maximum temperature of the aqueous solution during dispersion was 25 ° C., and the minimum temperature was 20 ° C.

Thereafter, the aqueous dispersion was filtered through a nylon mesh having an opening diameter of 80 μm, and the aqueous dispersion of the filtrate was degassed in a vacuum state at 23 ° C. (room temperature) to prepare an aqueous dispersion of clay mineral.
(Preparation of water-dispersed pressure-sensitive adhesive composition)
By mixing the water dispersion of the clay mineral with the water dispersion of the water dispersion polymer so that the clay mineral is 10 parts with respect to 100 parts of the water dispersion polymer, and stirring and mixing, 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 was performed on one side of the optical film.
(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.) so that the thickness after drying was 23 μm and 200 μm, respectively. Then, it was made to dry at 100 degreeC for 2 minute (s) with a hot-air circulation type oven, and the adhesive layer was formed on the release film. This was attached to an optical film that had been subjected to undercoating treatment to produce an adhesive optical film.

Example 2
In preparation of the aqueous dispersion of clay mineral in Example 1, it was the same as Example 1 except that sodium pyrophosphate (phosphate dispersant, manufactured by Wako Pure Chemical Industries, Ltd.) was added instead of sodium hexametaphosphate. Then, an aqueous dispersion of clay mineral was prepared, and then a water-dispersed pressure-sensitive adhesive composition was prepared to produce a pressure-sensitive optical film.

Example 3
In preparation of the aqueous dispersion of clay mineral in Example 1, it was the same as Example 1 except that sodium tripolyphosphate (phosphate dispersant, manufactured by Wako Pure Chemical Industries, Ltd.) was added instead of sodium hexametaphosphate. Then, an aqueous dispersion of clay mineral was prepared, and then a water-dispersed pressure-sensitive adhesive composition was prepared to produce a pressure-sensitive optical film.

Example 4
In the post-dispersing step of the preparation of the clay mineral aqueous dispersion in Example 1, the same procedure as in Example 1 was used, except that a disper (made by Special Machinery Co., Ltd.) was used instead of the homomixer (made by Special Machinery Co., Ltd.). Then, an aqueous dispersion of clay mineral was prepared, and then a water-dispersed pressure-sensitive adhesive composition was prepared to produce a pressure-sensitive optical film. Dispersion conditions for the disperser were a dispersion time of 15 minutes and a rotational speed of 3000 (1 / min) (= peripheral speed 330 m / s).

Example 5
In the immersion step of preparation of the clay mineral aqueous dispersion in Example 1, a water dispersion of clay mineral was prepared in the same manner as in Example 1 except that the water temperature during immersion was changed from 23 ° C. to 3 ° C. Subsequently, a water-dispersed pressure-sensitive adhesive composition was prepared, and a pressure-sensitive adhesive optical film was produced.
Example 6
Example 1 Except that the maximum temperature during dispersion was changed from 25 ° C. to 30 ° C. and the minimum temperature was changed from 20 ° C. to 25 ° C. in the post-dispersion step of the preparation of the clay mineral aqueous dispersion in Example 1. In the same manner as above, an aqueous dispersion of clay mineral was prepared, and then a water-dispersed pressure-sensitive adhesive composition was prepared to produce a pressure-sensitive optical film.

Example 7
In the immersion step of preparation of the aqueous dispersion of clay mineral in Example 1, the water of the clay mineral was changed in the same manner as in Example 1 except that the immersion time was changed from 4 days (96 hours) to 2 days (48 hours). A dispersion was prepared, and subsequently a water-dispersed pressure-sensitive adhesive composition was prepared to produce a pressure-sensitive adhesive optical film.

Example 8
In the preparation of the water-dispersed pressure-sensitive adhesive composition in Example 1, the blending ratio of the clay mineral aqueous dispersion was changed so that the clay mineral was 10 parts to 3 parts with respect to 100 parts of the water-dispersed polymer. A water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the pressure-sensitive adhesive optical film was produced.

Example 9
In preparation of the aqueous dispersion of clay mineral in Example 1, the pre-dispersion step was performed before the dipping step, and the same as in Example 1 except that sodium polycarboxylate was used instead of sodium hexametaphosphate. Then, an aqueous dispersion of clay mineral was prepared, and then a water-dispersed pressure-sensitive adhesive composition was prepared to produce a pressure-sensitive optical film.

  That is, 90 parts of ion-exchanged water was treated with Lucentite SPN (a quaternary ammonium salt having a propylene oxide skeleton having a hydroxyl group at the terminal, and the interlayer was hydrophobized in an amount of 120 mol eq./100 g. 10 parts were added, and the Lucentite SPN was dispersed with a homomixer at a water temperature of 7 to 20 ° C. for 5 minutes (pre-dispersion step).

After the pre-dispersion step, the solution was immersed for 4 days (96 hours) at 23 ° C. in a stationary state to swell Lucentite SPN in water (immersion step).
After the dipping process, sodium polycarboxylate (trade name: Aron A210, polycarboxylate-based dispersant, manufactured by Toagosei Co., Ltd.) was added and dissolved at a ratio of 30 parts to 100 parts of Lucentite SPN. Next, using a homomixer (manufactured by Tokushu Kika Co., Ltd.), the aqueous solution in which the Lucentite SPN was immersed was cooled in an ice-water bath to remove heat and 10000 (1 / min) (= peripheral speed 1100 m / min) for 15 minutes. The mixture was stirred and dispersed in s) (post-dispersion step). The maximum temperature of the aqueous solution during dispersion was 25 ° C., and the minimum temperature was 20 ° C.

Thereafter, the aqueous dispersion was filtered through a nylon mesh having an opening diameter of 80 μm, and the aqueous dispersion of the filtrate was degassed in a vacuum state at 23 ° C. (room temperature) to prepare an aqueous dispersion of clay mineral.
Thereafter, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, and then a pressure-sensitive adhesive optical film was produced.
Comparative Example 1
An aqueous dispersion of clay mineral was prepared in the same manner as in Example 1, except that in the immersion step of preparation of the aqueous dispersion of clay mineral in Example 1, the temperature during immersion was changed from 23 ° C to 40 ° C.

However, in the prepared aqueous dispersion of clay mineral, the clay mineral was phase-separated from water, and the clay mineral did not swell sufficiently. Therefore, a water-dispersed pressure-sensitive adhesive composition and a pressure-sensitive adhesive optical film could not be obtained.
Comparative Example 2
In the post-dispersing step of the preparation of the clay mineral aqueous dispersion in Example 1, an ultrasonic disperser (US-600T, manufactured by Nissei) was used instead of the homomixer (manufactured by Special Machinery Corporation). An aqueous dispersion of clay mineral was prepared in the same manner as in Example 1, and then an aqueous dispersion type pressure-sensitive adhesive composition was prepared. The maximum temperature during dispersion in the post-dispersion step was 50 ° C., and the minimum temperature was 45 ° C.

However, in the prepared aqueous dispersion of clay mineral, the clay mineral was phase-separated from water, and the clay mineral did not swell sufficiently. Therefore, a water-dispersed pressure-sensitive adhesive composition and a pressure-sensitive adhesive optical film could not be obtained.
Comparative Example 3
In the preparation of the clay mineral aqueous dispersion in Example 1, a clay mineral aqueous dispersion was prepared in the same manner as in Example 1 except that sodium hexametaphosphate was not added. A composition was prepared. However, many aggregates were generated in the water-dispersed pressure-sensitive adhesive composition.

Using this water-dispersed pressure-sensitive adhesive composition, a pressure-sensitive adhesive optical film was produced in the same manner as in Example 1. However, white turbidity was observed and the appearance was poor.
Comparative Example 4
In the preparation of the clay mineral aqueous dispersion of Example 1, before immersing the Lucentite SPN (that is, during the immersing step), first, sodium hexametaphosphate was added to and dissolved in ion-exchanged water, and then this hexametaline. A clay mineral aqueous dispersion was prepared in the same manner as in Example 1 except that Lucentite SPN was added to the sodium acid aqueous solution. However, the clay mineral was not sufficiently swollen in the prepared aqueous dispersion of clay mineral.

Subsequently, an aqueous dispersion type pressure-sensitive adhesive composition was prepared from this clay mineral aqueous dispersion in the same manner as in Example 1. However, many aggregates were generated in the water-dispersed pressure-sensitive adhesive composition.
Thereafter, an adhesive optical film was produced from this water-dispersed adhesive composition in the same manner as in Example 1.
Comparative Example 5
In the preparation of the water-dispersed pressure-sensitive adhesive composition in Example 1, a water-dispersed pressure-sensitive adhesive composition was prepared in the same manner as in Example 1 except that the clay mineral aqueous dispersion was not blended. A film was prepared.

Comparative Example 6
An aqueous dispersion of clay mineral was prepared in the same manner as in Example 1, except that the immersion time in the preparation of the aqueous dispersion of clay mineral in Example 1 was changed from 4 days (96 hours) to 12 hours. did.
However, the clay mineral was not sufficiently swollen in the prepared aqueous dispersion of clay mineral. Therefore, a water-dispersed pressure-sensitive adhesive composition and a pressure-sensitive adhesive optical film could not be obtained.

Table 1 shows the formulation of each example and each comparative example.
(Evaluation)
1) Dispersion State In Examples 1 to 9 and Comparative Examples 1 to 4 and 6, the state of the clay mineral aqueous dispersion and the pressure-sensitive adhesive layer were evaluated by appearance observation. The results are shown in Table 1.

The dispersion state was confirmed according to the following criteria.
A: No aggregation or phase separation was observed in the aqueous dispersion, and no foreign matter or white turbidity was observed in the adhesive layer. ○: No aggregation or phase separation was observed in the aqueous dispersion, and no foreign matter was observed in the adhesive layer. However, some cloudiness was observed. Δ: No phase separation was observed in the aqueous dispersion, but aggregates were observed. ×: Aggregation and phase separation were observed in the aqueous dispersion. 2) Haze value Examples 1 to 9 and Comparative Examples 3 to 5 were cut into 50 × 50 mm, and the haze value of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive optical film was determined according to JIS K7136 according to haze meter (Murakami Color Technology). Measured by a laboratory company, "HM-150 type"). The results are shown in Table 1.

3) Total light transmittance The adhesive optical films obtained in Examples 1 to 9 and Comparative Examples 3 to 5 were cut into 50 × 50 mm, and the total light transmittance of the adhesive layer in the adhesive optical film was determined according to JIS. Based on K7361-1, it was measured with a haze meter (Murakami Color Research Laboratory Co., Ltd., “HM-150 type”). The results are shown in Table 1.

4) Adhesive Fixability of Adhesive Optical Film The adhesive optical film obtained in Examples 1 to 9 and Comparative Example 5 and having a pressure-sensitive adhesive layer thickness of 23 μm was cut into a rectangular shape having a size of 230 × 310 mm. Thereafter, the release film was peeled off, and this was attached to a 0.7 mm thick glass plate (Corning # 1737, manufactured by Corning) and left in an autoclave at 50 ° C. and 0.5 MPa for 15 minutes. Then, when it heated for 500 hours in 60 degreeC and 90% RH atmosphere, the presence or absence of the part peeled from the edge part of an adhesive optical film and the length of the peeled part were confirmed by visual observation. The results are shown in Table 1.

In addition, about the peeling part of the adhesion type optical film, it confirmed on the following reference | standard.
◎: No change such as peeling was observed. ○: Peeling was observed at a portion of 0.5 mm or less from the edge of the adhesive optical film. △: 0.5 mm from the edge of the adhesive optical film exceeded 1 mm. Peeling was observed in the following parts. X: Peeling was observed in a part exceeding 1 mm from the end of the adhesive optical film. Abbreviated names of the dispersants in Table 1 are shown below.
-Na hexametaphosphate: sodium hexametaphosphate, phosphate dispersant, manufactured by Kishida Chemical Co., Ltd.-Na pyrophosphate: sodium pyrophosphate, phosphate dispersant, manufactured by Wako Pure Chemical Industries, Ltd.-Tripolyphosphate Na: sodium tripolyphosphate , Phosphate dispersant, manufactured by Wako Pure Chemical Industries, Ltd., polycarboxylic acid Na: sodium polycarboxylate, trade name: Aron A210, polycarboxylate dispersant, manufactured by Toagosei Co., Ltd.

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

Explanation of symbols

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

Claims (10)

An immersion step of immersing the smectite-based layered clay mineral treated with a quaternary ammonium salt in water at 35 ° C. or lower for 24 hours or more;
After the immersion step, a phosphate-based dispersant or a polycarboxylate-based dispersant is added to the water, and then the clay mineral is dispersed in the water at 0 to 35 ° C. by a dispersing device. And a dispersion step. A method for dispersing clay minerals in water.   The water dispersion method of clay mineral according to claim 1, further comprising a pre-dispersion step of dispersing the smectite-based layered clay mineral in water at 0 to 20 ° C before the dipping step.   3. The method for dispersing water of clay minerals according to claim 1, wherein, in the post-dispersing step, a content ratio of the clay mineral is 5 to 20 parts by weight with respect to 100 parts by weight of the water. .   In the post-dispersion step, a blending ratio of the phosphate dispersant or the polycarboxylate dispersant is 1 to 40 parts by weight with respect to 100 parts by weight of the clay mineral. Item 4. A method for dispersing a clay mineral in water according to any one of Items 1 to 3.   5. The water dispersion of a clay mineral according to claim 1, wherein the clay mineral has a smectite-based layered clay mineral organically treated with a quaternary ammonium salt having a hydroxyl group. Method. A water-dispersed polymer;
An aqueous dispersion of clay mineral obtained by the water dispersion method of clay mineral according to any one of claims 1 to 5,
A water-dispersed pressure-sensitive adhesive composition, wherein the clay mineral is blended in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of the water-dispersed polymer.   The water-dispersed pressure-sensitive adhesive composition according to claim 6, wherein when formed into a sheet having a thickness of 200 μm, the haze value is 3% or less and the total light transmittance is 90 to 100%. A support;
A pressure-sensitive adhesive film comprising: a pressure-sensitive adhesive layer made of the water-dispersed pressure-sensitive adhesive composition according to claim 6 or 7, which is laminated on at least one side of the support.   The pressure-sensitive adhesive film according to claim 8, wherein the support is an optical film.   An image display device comprising at least one adhesive optical film according to claim 9.

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