JP2003049129A - Method for producing acrylic adhesive tape and acrylic adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an acrylic adhesive tape and to obtain an adhesive tape having excellent adhesive property, especially suitable for optical uses. SOLUTION: This method for producing an acrylic adhesive tape comprises casting a composition comprising (a) 100 pts.wt. of an acrylic monomer, (b) 5-200 pts.wt. of a high-molecular weight polymer having >=50,000 weight-average molecular weight, and, if necessary, (c-1) a polymer having a high Tg and a low molecular weight of <=20,000 weight-average molecular weight and 25-200 deg.C Tg or (c-2) a polymer having a low Tg and a low molecular weight of <=20,000 weight-average molecular weight and -85 to 20 deg.C Tg, (d) a photopolymerization initiator and (e) a crosslinking agent on a substrate and carrying out a reaction at 0-10 deg.C. This acrylic adhesive tape is obtained by the method.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a pressure-sensitive adhesive tape using an acrylic pressure-sensitive adhesive composition containing substantially no solvent, and the pressure-sensitive adhesive tape thus obtained.

[0002]

2. Description of the Related Art Conventionally, rubber-based adhesives and synthetic rubbers have been used as pressure-sensitive adhesives, but sufficient adhesive strength cannot be obtained only with these components. In order to impart effective properties to such a pressure sensitive adhesive, a tackifier such as a rosin acid derivative is added to the conventional pressure sensitive adhesive.

For example, in the case of an acrylic pressure-sensitive adhesive, the (meth) acrylic polymer has a tackiness on its own and can be a pressure-sensitive adhesive having good heat resistance and weather resistance without adding a tackifier. The adhesiveness at room temperature and the adhesiveness to low energy surfaces such as polyolefin and automobile paint surfaces are inferior to those to which a tackifier is added.
Even in such an acrylic pressure-sensitive adhesive, effective adhesion characteristics are imparted by adding a tackifier.

However, the improvement in the adhesive properties brought about by the addition of such a tackifier is not always satisfactory. There is also a problem caused by adding such a tackifier to an acrylic pressure-sensitive adhesive. When a general commercially available tackifier such as a rosin acid derivative is added to an acrylic pressure-sensitive adhesive, transparency and weather resistance are often lowered. Furthermore, when such a tackifier is present during the bulk polymerization reaction,
It acts as a chain transfer agent and a reaction terminator due to its structure,
There is a possibility that the polymerization reaction may be hindered or delayed.

It is also known to blend an acrylic polymer as a tackifier in a pressure sensitive adhesive. For example, JP-A-54-3136 discloses a pressure-sensitive adhesive containing an acrylic polymer and a tackifier. The tackifier used here is obtained by solution polymerization of a vinyl aromatic compound and a (meth) acrylic acid ester, and has a number average molecular weight of 500.
˜3000, and the softening point is 40 ° C. or lower. On the other hand, JP-A-1-139665 discloses that the number of carbon atoms is 1 to 1.
Obtained by polymerizing a (meth) acrylate having 20 alkyl and cycloalkyl groups, a free radical compatible olefinic acid (specifically acrylic acid, etc.), and optionally other ethylenically unsaturated monomers. An invention of an adhesive composition containing a polymer type additive having a number average molecular weight of 35,000 or less and a softening point of 40 ° C. or more is disclosed. In this publication, polymer type additives are
It is described that it can be produced by any of emulsion polymerization, suspension polymerization, solution polymerization and bulk polymerization. Further, in this publication, "this polymer-type additive is added to an adhesive composition by a known method such as a mixing or blending method so that the additive is uniformly contained in the adhesive composition. The additive is preferable. Is added to the pressure-sensitive adhesive composition in the form of an emulsion or an emulsion in an aqueous / organic solvent combined solute. "

However, in this publication, the polymer-type additive is produced by emulsion polymerization or solution polymerization, and thus prepared by emulsion polymerization or solution polymerization in a state of being emulsified and dispersed in a solvent or a dispersion medium. It is included in the adhesive. As described above, in the above publications, the use of the pressure-sensitive adhesive and the polymer-type additive both obtained by emulsion polymerization or solution polymerization is based on the conventional method of polymerizing an acrylic monomer without using a solvent or a dispersion medium. Although it has been known that it is possible (bulk polymerization), it is extremely difficult to control the reaction in the polymerization of an acrylic monomer which is carried out without using such a solvent or dispersion medium, and a polymer having a certain property can be selectively selected. Because it could not be manufactured. Further, the pressure-sensitive adhesive and the polymer-type additive produced by solution polymerization or emulsion polymerization can be easily produced by mixing with a solvent or a dispersion medium to form a homogeneous composition.

However, when adhering using such a solvent-based pressure-sensitive adhesive composition or an emulsion-type pressure-sensitive adhesive composition, a step of removing the solvent or water is required. For example, water having a large latent heat of vaporization was used. In some cases, the drying process becomes very long. Further, when an organic solvent is used, there is a problem in that an apparatus for capturing the organic solvent that diffuses is also required, and there is a concern that it may affect the environment.

On the other hand, as a method for producing a pressure-sensitive adhesive without using a solvent or a dispersion medium, there are JP-A-50-87129 and JP-A-50-102635, and these publications include: A mixture of (meth) acrylic acid alkyl ester and a vinyl monomer having a specific polar group,
A method for producing a pressure-sensitive adhesive tape is disclosed, in which a mixture obtained by adding these (co) polymers and a polymerization initiator is applied to a support sheet and heat-polymerized. In JP-A-50-87129, a redox type polymerization initiator is used because the polymerization does not proceed smoothly with an ordinary polymerization initiator due to the polymerization inhibiting action of oxygen. In JP-A-102635, a release sheet or belt is laid on the coated raw material pressure-sensitive adhesive composition, and contact with oxygen is cut off to cause a thermal polymerization reaction.

Thus, by using (meth) acrylic acid alkyl ester as a solvent and mixing an acrylic (co) polymer therein, a tape having a pressure-sensitive adhesive property is produced without using an organic solvent. be able to. However, in the method disclosed in the above-mentioned publication, since the monomer used as the solvent is polymerized by heat polymerization, the surface portion of the coating layer that is likely to come into contact with oxygen in the air is always mixed with oxygen. There is a risk of stopping the reaction due to contact,
There is a problem that it is difficult to uniformly polymerize in the layer thickness direction. Also, the monomers used here are
Since it is necessary to dissolve the (co) polymer, it has the same or similar composition as the solute (co) polymer. Therefore, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape obtained by the method described in the above publication is formed of a (co) polymer having almost the same composition.

Having such a nearly single composition (co)
A pressure-sensitive adhesive layer made of a polymer does not exhibit sufficient adhesive strength with respect to an adherend such as polyolefin which is said to be difficult to adhere. Further, in JP-A-2-60981, a liquid material obtained by adding a photopolymerization initiator to a vinyl-based monomer containing an alkyl acrylate as a main component is applied or impregnated on a base material to have a strength of 1 to 300 W / m. by irradiating the ^second ultraviolet rays polymerization reaction of at least 90 wt%, then an acrylic pressure-sensitive adhesive tape manufacturing method to complete the polymerization reaction by irradiation with the intensity or more ultraviolet radiation is disclosed. Then, in this method, in order to prevent polymerization inhibition and polymerization delay by oxygen, a method of performing an inert gas purge or a method of covering the surface with a polyester film to prevent contact with oxygen, or a compound having a deoxidizing effect. And the like are disclosed. However, such a method cannot completely remove dissolved oxygen. Furthermore, under the conditions for obtaining the high molecular weight polymer described in this publication, the polymerization is delayed due to the influence of dissolved oxygen in the initial stage of the polymerization. Therefore, there is a problem that the polymerization reaction time (UV irradiation time) becomes long and the productivity decreases.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing an acrylic pressure-sensitive adhesive tape having excellent adhesive properties such as adhesive force and cohesive force by photopolymerization. Another object of the present invention is to provide an acrylic pressure-sensitive adhesive tape having excellent adhesive properties such as adhesive force and cohesive force.

Another object of the present invention is to provide an acrylic pressure-sensitive adhesive tape, which is particularly suitable for sticking optical members, and a method for producing the same.

[0013]

SUMMARY OF THE INVENTION The method for producing an acrylic pressure-sensitive adhesive tape according to the present invention comprises: (a) an acrylic monomer containing a (meth) acrylic acid ester as a main component; 5 to 200 parts by weight of a high molecular weight polymer having a (meth) acrylic acid ester component unit as a main constituent unit and a weight average molecular weight of 50,000 or more, and if necessary, (c-1) a (meth) acrylic acid ester component unit. The main constitutional unit, the weight average molecular weight is 20,000 or less,
High glass transition temperature (Tg) in the range of 25-200 ℃
Tg low molecular weight polymer or (c-2) (meth) acrylic acid ester component unit as a main constituent unit, the weight average molecular weight is 20,000 or less, the glass transition temperature (Tg)-
Low Tg low molecular weight polymer in the range of 85 to 20 ° C
˜300 parts by weight, (d) a photopolymerization initiator in an amount of 0.01 to 5 parts by weight, and (e) a cross-linking agent, and containing substantially no solvent, the composition is drowned on a support. The composition temperature is 0 to 1
It is characterized in that the composition is reacted while being maintained within the range of 0 ° C.

The acrylic adhesive tape of the present invention is
The composition containing a support and the above-mentioned components (a) to (e) sprinkled on the support and containing substantially no solvent has a temperature of 0 to
It is characterized by having a pressure-sensitive adhesive layer in which the composition is reacted while being maintained within a range of 10 ° C. In the present invention, by maintaining the temperature of the composition drowned on the support within the range of 0 to 10 ° C. to allow the polymerization reaction to proceed, the reaction does not proceed rapidly, and the radical chain The migration reaction is also suppressed. Furthermore, since the reaction activity of the surface of the composition coated on the support is low, the composition is less affected by oxygen in the air when it reacts, and thus a desired pressure-sensitive adhesive layer can be formed. it can.

[0015]

DETAILED DESCRIPTION OF THE INVENTION Next, the acrylic pressure-sensitive adhesive tape of the present invention will be specifically described along with its manufacturing method.
The acrylic pressure-sensitive adhesive tape of the present invention comprises (a) an acrylic monomer, (b) a high molecular weight polymer, and (c-1) a high Tg, if necessary.
Low-molecular weight polymer, or (c-2) low Tg low-molecular weight polymer, (d) a photopolymerization initiator, (e) a support containing a composition containing a cross-linking agent, substantially no solvent It is produced by carrying out a polymerization reaction on the body under specific temperature conditions.

The (a) acrylic monomer used in the present invention is a monomer whose main component is (meth) acrylic acid ester. This (a) acrylic monomer mainly composed of (meth) acrylic ester dissolves or disperses a specific high molecular weight polymer and a low molecular weight polymer described later, and at the same time, the (a) acrylic monomer itself is copolymerized. To form an adhesive.

Examples of such an acrylic monomer containing (a) (meth) acrylic ester as a main component include:
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic acid-2- (Meth) acrylic acid alkyl ester such as ethylhexyl, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate; (meth) acrylate such as cyclohexyl (meth) acrylate ) Esters of acrylic acid with alicyclic alcohols; aryl (meth) acrylates such as phenyl (meth) acrylate and benzyl (meth) acrylate can be mentioned. Such (meth) acrylic acid ester can be used alone or in combination.

The (a) acrylic monomer having a (meth) acrylic acid ester as a main component used in the present invention contains the above-mentioned (meth) acrylic acid ester as a main component, but further contains another monomer. You may have. Examples of other monomers that can be used in the present invention include:
Such as (meth) acrylic acid, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate. ) Alkoxyalkyl acrylates; salts such as alkali metal salts of (meth) acrylic acid; ethylene glycol di (meth) acrylic acid esters, diethylene glycol di (meth) acrylic acid esters, triethylene glycol di (meth) acrylic acid esters , Such as polyethylene glycol di (meth) acrylic acid ester, propylene glycol di (meth) acrylic acid ester, dipropylene glycol di (meth) acrylic acid ester, tripropylene glycol di (meth) acrylic acid ester ( Poly) Di (meth) acrylic acid esters of Ruki glycol; polyvalent (meth) acrylic acid esters such as trimethylolpropane tri (meth) acrylate; (meth) acrylonitrile; vinyl acetate;
Vinylidene chloride; vinyl halide compounds such as 2-chloroethyl (meth) acrylate; (meth) acrylic acid esters of cycloaliphatic alcohols such as cyclohexyl (meth) acrylate; 2-vinyl-2-oxazoline, 2 -Vinyl-5-methyl-2-oxazoline, oxazoline group-containing polymerizable compounds such as 2-isopropenyl-2-oxazoline;
(Meth) acryloylaziridine, (meth) acrylic acid
Aziridine group-containing polymerizable compounds such as -2-aziridinylethyl; such as allyl glycidyl ether, (meth) acrylic acid glycidyl ether, (meth) acrylic acid glycidyl ether, (meth) acrylic acid-2-ethyl glycidyl ether Epoxy group-containing vinyl monomer; (meth) acrylic acid-2-hydroxyethyl, acrylic acid-2-hydroxypropyl, monoester of (meth) acrylic acid with polypropylene glycol or polyethylene glycol, lactones and (meth) Hydroxyl group-containing vinyl compounds such as adducts with 2-hydroxyethyl acrylate; Fluorine-containing vinyl monomers such as fluorine-substituted methacrylic acid alkyl esters, fluorine-substituted acrylic acid alkyl esters; itaconic acid, crotonic acid, maleic acid Unsaturated carvone such as fumaric acid (But excluding (meth) acrylic acid), salts thereof, and (partial) ester compounds and acid anhydrides thereof; reactive halogen-containing vinyl monomers such as 2-chloroethyl vinyl ether and monochlorovinyl acetate; methacrylamide. , N-methylol methacrylamide, N-methoxyethyl methacrylamide, N-
Amide group-containing vinyl monomers such as butoxymethylmethacrylamide; such as vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, and 2-methoxyethoxytrimethoxysilane. Other examples include organic silicon group-containing vinyl compound monomers; and macromonomers having a radically polymerizable vinyl group at the terminal of a vinyl group-polymerized monomer. Such monomers can be copolymerized with the above-mentioned (meth) acrylic acid ester alone or in combination.

However, in the present invention, the (a) acrylic monomer has a (meth) acrylic acid ester as a main component, and therefore, the (meth) acrylic acid ester is 50
It is contained in an amount of not less than 70% by weight, preferably not less than 70% by weight, more preferably not less than 90% by weight. The (b) high molecular weight polymer used in the present invention has a (meth) acrylic acid ester component unit as a main constituent unit, and has a weight average molecular weight of 50,000 or more, preferably 100,000 to 20,000.
It is an acrylic polymer in the range of 00. In addition,
In the present invention, the weight average molecular weight is a value determined by gel permeation chromatography (GPC).

The high molecular weight tacky polymer (b) is formed by polymerizing a monomer having a polymerizable unsaturated bond containing (meth) acrylic acid ester as a main component. In the present invention, as such (meth) acrylic acid ester, (meth) acrylic acid alkyl ester of (meth) acrylic acid and alcohol having an alkyl group having 1 to 20 carbon atoms, (meth) acrylic acid and 3 to 3 carbon atoms are used. Ester of 14 alicyclic alcohol and ester of (meth) acrylic acid and aromatic alcohol having 6 to 14 carbon atoms can be used.

Examples of such (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth)
Butyl acrylate, Pentyl (meth) acrylate, Hexyl (meth) acrylate, 2-Ethylhexyl (meth) acrylate, Octyl (meth) acrylate, Nonyl (meth) acrylate, Decyl (meth) acrylate, ( Meta)
(Meth) acrylic acid alkyl ester such as dodecyl acrylate; ester of (meth) acrylic acid such as cyclohexyl (meth) acrylate with alicyclic alcohol; phenyl (meth) acrylate, benzyl (meth) acrylate Such (meth) acrylic acid aryl ester can be mentioned. Such (meth) acrylic acid ester can be used alone or in combination.

The high molecular weight polymer (b) used in the present invention is prepared by using the above-mentioned (meth) acrylic acid ester as a main component as a monomer having a polymerizable unsaturated bond. Therefore, the (b) high molecular weight polymer used in the present invention has a repeating unit ((meth) acrylic acid ester component unit) derived from the above-mentioned (meth) acrylic acid ester in a monomer conversion of 50 It is contained in an amount of not less than 70% by weight, preferably not less than 70% by weight, more preferably not less than 90% by weight.

The high molecular weight polymer (b) used in the present invention is a repeating polymer derived from a monomer copolymerizable with (meth) acrylic acid ester in addition to the above-mentioned (meth) acrylic acid ester component unit. It may have a unit. Examples of such a monomer include (meth) acrylic acid, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate,
Alkoxyalkyl (meth) acrylates such as butoxyethyl (meth) acrylate and ethoxypropyl (meth) acrylate; salts such as alkali metal salts of (meth) acrylic acid; di (meth) acrylic acid esters of ethylene glycol, diethylene glycol Di (meth) acrylic acid ester, triethylene glycol di (meth) acrylic acid ester, polyethylene glycol di (meth) acrylic acid ester, propylene glycol di (meth) acrylic acid ester, dipropylene glycol di (meth) acrylic acid ester ) Acrylic esters, di (meth) acrylic acid esters of (poly) alkylene glycols such as di (meth) acrylic acid esters of tripropylene glycol; polyvalent (meth) acrylates such as trimethylolpropane tri (meth) acrylic acid esters ) Acrylic acid ester; (meth) acrylonitrile, vinyl acetate, vinylidene chloride; (meth)
Halogenated vinyl compounds such as 2-chloroethyl acrylate; 2-vinyl-2-oxazoline, 2-vinyl-5-methyl
-Oxazoline, 2-isopropenyl-2-oxazoline-containing oxazoline group-containing polymerizable compound; (meth) acryloylaziridine, (meth) acrylate-2-aziridinylethyl-containing polymerizable compound Allyl glycidyl ether, (meth) acrylic acid glycidyl ether, (meth) acrylic acid glycidyl ether,
Epoxy group-containing vinyl monomer such as (meth) acrylic acid-2-ethylglycidyl ether; (meth) acrylic acid
Such as 2-hydroxyethyl, 2-hydroxypropyl acrylate, monoesters of (meth) acrylic acid with polypropylene glycol or polyethylene glycol, adducts of lactones with 2-hydroxyethyl (meth) acrylate. Hydroxyl group-containing vinyl compound; Fluorine-containing vinyl monomers such as fluorine-substituted methacrylic acid alkyl ester and fluorine-substituted acrylic acid alkyl ester; unsaturated carboxylic acids such as itaconic acid, crotonic acid, maleic acid and fumaric acid (however, (meta ) Excluding acrylic acid),
These salts and their (partial) ester compounds and acid anhydrides; reactive halogen-containing vinyl monomers such as 2-chloroethyl vinyl ether and monochlorovinyl acetate; methacrylamide, N-methylolmethacrylamide, N-methoxyethyl. Amide group-containing vinyl monomers such as methacrylamide, N-butoxymethylmethacrylamide; vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, 2-methoxyethoxytriamine Examples thereof include organic silicon group-containing vinyl compound monomers such as methoxysilane; and macromonomers having a radically polymerizable vinyl group at the terminal of a vinyl group-polymerized monomer. Such monomers can be copolymerized with the above-mentioned (meth) acrylic acid ester alone or in combination.

Examples of the high molecular weight polymer (b) used in the present invention include copolymers of butyl acrylate / 2-ethylhexyl acrylate / acrylic acid / 2-hydroxyethyl acrylate, 2-ethylhexyl acrylate / acrylic acid / 2. There may be mentioned copolymers such as hydroxyethyl acrylate. This (b) high molecular weight polymer usually has a glass transition temperature (Tg),
The glass transition temperature (Tg) of high molecular weight polymers is
Tg has a lower glass transition temperature (Tg) than low molecular weight polymers. That is, the glass transition temperature (Tg) of this (b) high molecular weight polymer is usually 0 to -85 ° C, preferably-.
5 to -85 ° C.

The high molecular weight polymer (b) is added in an amount of 5 to 200 parts by weight, preferably 5 to 150 parts by weight, based on 100 parts by weight of the acrylic monomer (a).
By using the high molecular weight polymer (b) in such an amount, the high molecular weight polymer (b) can be satisfactorily dissolved or dispersed in the acrylic monomer (a). The composition used in the present invention includes (c-1) a high Tg low molecular weight polymer, or (c-
2) Add low Tg low molecular weight polymer as needed.

Here, (c-1) the high Tg low molecular weight polymer is
It is a polymer having a (meth) acrylic acid ester component unit as a main constituent unit, and its weight average molecular weight is 20,000 or less, preferably 10,000 or less, and particularly 10,000.
The glass transition temperature (Tg) of the acrylic polymer is 25 to 200 ° C., preferably 40.
Within the range of ~ 180 ° C.

The (c-2) low Tg low molecular weight polymer used in the present invention is a polymer having a (meth) acrylic acid ester component unit as a main constituent unit, and its weight average molecular weight is 20,000 or less, preferably Is 10000 or less, particularly in the range of 10,000 to 2000, and the glass transition temperature (Tg) of this acrylic polymer is -85 to 20.
Within the range of ° C. When the weight average molecular weight of this (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer exceeds 20,000, the effect of improving the adhesive performance of the adhesive tape obtained using the composition of the present invention is Not fully expressed.

In the above (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer, the (meth) acrylic acid ester is a polymer containing (meth) acrylic acid ester as a main component. It is formed by polymerizing a monomer having a polyunsaturated bond. In the present invention, such (meta)
As the acrylate ester, (meth) acrylic acid alkyl ester of (meth) acrylic acid and alcohol having an alkyl group having 1 to 20 carbon atoms, and (meth) acrylic acid and alicyclic alcohol having 3 to 14 carbon atoms ester,
An ester of (meth) acrylic acid and an aromatic alcohol having 6 to 14 carbon atoms can be used.

Examples of such (meth) acrylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth)
Butyl acrylate, Pentyl (meth) acrylate, Hexyl (meth) acrylate, 2-Ethylhexyl (meth) acrylate, Octyl (meth) acrylate, Nonyl (meth) acrylate, Decyl (meth) acrylate, ( Meta)
(Meth) acrylic acid alkyl ester such as dodecyl acrylate; ester of (meth) acrylic acid such as cyclohexyl (meth) acrylate with alicyclic alcohol; phenyl (meth) acrylate, benzyl (meth) acrylate Such (meth) acrylic acid aryl ester can be mentioned. Such (meth) acrylic acid ester can be used alone or in combination. The (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer used in the present invention is composed of the above-mentioned (meth) acrylic acid ester as a main component as a monomer having a polymerizable unsaturated bond. Is prepared using. Therefore,
The (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer used in the present invention is a repeating unit ((meth) acryl) derived from the above-mentioned (meth) acrylic acid ester. The acid ester component unit) is contained in an amount of 50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more in terms of monomer.

The (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer used in the present invention is a (meth) acrylic ester in addition to the above (meth) acrylic acid ester component unit. It may have a repeating unit derived from a monomer copolymerizable with the acid ester. Examples of such a monomer include (meth) acrylic acid, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, (meth)
Butoxyethyl acrylate, alkoxyalkyl (meth) acrylate such as ethoxypropyl (meth) acrylate; salts such as alkali metal salts of (meth) acrylic acid; ethylene glycol di (meth) acrylic acid ester, diethylene glycol di ( (Meth) acrylic acid ester,
Triethylene glycol di (meth) acrylic acid ester, polyethylene glycol di (meth) acrylic acid ester, propylene glycol di (meth) acrylic acid ester, dipropylene glycol di (meth) acrylic acid ester, tripropylene glycol di (meth) acrylic acid ester Di (meta)
Di (meth) acrylic acid ester of (poly) alkylene glycol such as acrylic acid ester; trimethylolpropane poly (meth) acrylic acid ester such as tri (meth) acrylic acid ester; (meth) acrylonitrile; vinyl acetate; Vinylidene chloride; (meth) acrylic acid
-2-Vinyl halide compounds such as chloroethyl; 2-
Oxazoline group-containing polymerizable compounds such as vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline; (meth) acryloylaziridine, (meth) acrylic acid-2- Aziridine group-containing polymerizable compounds such as aziridinylethyl; allyl glycidyl ether, (meth) acrylic acid glycidyl ether, (meth) acrylic acid glycidyl ether, (meth)
Epoxy group-containing vinyl monomer such as 2-ethyl glycidyl acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl acrylate,
Hydroxy group-containing vinyl compounds such as monoesters of (meth) acrylic acid and polypropylene glycol or polyethylene glycol, adducts of lactones and 2-hydroxyethyl (meth) acrylate; fluorine-substituted methacrylic acid alkyl esters, fluorine Fluorine-containing vinyl monomers such as substituted acrylic acid alkyl esters; unsaturated carboxylic acids such as itaconic acid, crotonic acid, maleic acid and fumaric acid (excluding (meth) acrylic acid), salts thereof and these ( Partial) ester compounds and acid anhydrides; reactive halogen-containing vinyl monomers such as 2-chloroethyl vinyl ether, monochlorovinyl acetate; methacrylamide, N-methylolmethacrylamide, N-methoxyethylmethacrylamide, N-butoxymethyl. Like methacrylamide Vinyl group-containing vinyl monomers; vinyl compounds containing organosilicon groups such as vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, and 2-methoxyethoxytrimethoxysilane. Other than the monomers, macromonomers having a radically polymerizable vinyl group at the terminal of a vinyl group-polymerized monomer can be used. Such monomers can be copolymerized with the above-mentioned (meth) acrylic acid ester alone or in combination.

Further, it is preferable that a functional group having reactivity with an epoxy group or an isocyanate group is introduced into this (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer. Examples of such functional groups include hydroxyl group, carboxyl group, amino group, amide group, mercapto group, (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer It is preferable to use a monomer having such a functional group in the production of Usually, the (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer is used in an amount of 5 to 300 parts by weight based on 100 parts by weight of the (a) acrylic monomer. It is used, preferably in an amount of 10 to 200 parts by weight. By using such (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer, the resulting acrylic pressure-sensitive adhesive tape will have excellent stress relaxation properties and sticking Even if the area becomes large, there is little deterioration in the sticking performance at the outer peripheral portion of the sticking surface. This tendency is particularly high when the low Tg low molecular weight polymer (c-2) having a low glass transition temperature (Tg) is used. The property that the adhesive performance does not change in the outer peripheral portion of the adhesive surface when such an adhesive area is large is particularly important as an adhesive tape for optical elements such as liquid crystal elements. That is, for example, in a liquid crystal element, a polarizing plate is attached to the surface of a transparent substrate, but as the liquid crystal element becomes larger, the stress at the end edge where the transparent substrate and the polarizing plate are bonded becomes larger, and this peripheral edge The phenomenon of light leakage, where light leaks from the part, is likely to occur. Such internal stress is more efficiently relaxed by using (c-2) low Tg low molecular weight polymer than using high Tg low molecular weight polymer (c-1) with high glass transition temperature (Tg). be able to. Therefore, in the present invention, the adhesive tape using (c-2) low Tg low molecular weight polymer as the low molecular weight polymer is particularly suitable for optical use. On the other hand, the adhesive tape using a low molecular weight polymer (c-1) with a high glass transition temperature (Tg) is (c-2) low Tg.
Compared with the adhesive tape using low molecular weight polymer,
It shows higher heat resistance and very good wet heat stability.

Further, in the present invention, a composition used for producing an acrylic pressure-sensitive adhesive tape is used without using the above (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer. It can also be prepared. The adhesive tape prepared without using this (c-1) high Tg low molecular weight polymer or (c-2) low Tg low molecular weight polymer does not change its properties due to heat, and has excellent heat resistance and Shows resistance to moist heat.

The composition used in the present invention has the above (a)
Ingredient, (b) ingredient, and further blended if necessary (c-1)
Component or (c-2) component, (d) photopolymerization initiator and (e)
And a crosslinking agent. The photopolymerization initiator (d) used in the present invention is a photoradical polymerization initiator and / or a photocationic polymerization initiator, examples of which include 4- (2-hydroxyethoxy) phenyl (2-hydroxy). -2-Propyl) ketone [eg Ciba Geigy, trade name: Darocur 2959], α-hydroxy-α, α'-dimethylacetophenone [eg Ciba Geigy, trade name: Darocur 1173], methoxyacetophenone, 2,2- Dimethoxy
-2-Phenylacetone [eg Ciba-Geigy, trade name: Irgacure 651], 2-hydroxy-2-cyclohexylacetophenone [Ciba-Geigy, trade name: Irgacure 184] and other acetophenone-based photopolymerization initiators; benzyldimethyl Examples thereof include ketal-based photopolymerization initiators such as ketals; other halogenated ketones, photopolymerization initiators such as acylphosphinoxide and acylphosphanate.

The photopolymerization initiator (d) is 0.01 to 5 parts by weight, preferably 0.01 to 3 parts by weight, and particularly preferably 0.1 to 100 parts by weight of the acrylic monomer (a). It is compounded in an amount within the range of 05 to 2 parts by weight. Also,
The composition used in the present invention further contains (e) a crosslinking agent. The cross-linking agent used in the present invention forms a cross-linking structure between the component (a), the component (b), and the component formed by the polymerization of the component (c-1) or the component (c-2). Is a compound to be obtained.

Examples of such a cross-linking agent include a compound having an epoxy group (polyfunctional epoxy compound) and a compound having an isocyanate group (polyfunctional isocyanate compound).
Can be mentioned. Specific examples of the compound having an epoxy group include bisphenol A, epichlorohydrin type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol glycidyl. Ether, trimethylolpropane triglycidyl ether,
Diglycidyl aniline, diamine glycidyl amine, N,
N, N ', N'-Tetraglycidyl-m-xylylenediamine and 1,3-bis (N, N'-diamineglycidylaminomethyl)
Cyclohexane and the like can be mentioned, and examples of the isocyanate compound include tolylene diisocyanate,
Hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, tetramethylxylylene diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate and trimethylol thereof An adduct with a polyol such as propane may be mentioned.

This cross-linking agent is the above-mentioned component (a) component (b) component (c-1)
With respect to the total of 100 parts by weight of the component (c-2) component, 0.01
To 5 parts by weight, preferably 0.01 to 3 parts by weight. When the above-mentioned polymerization initiator and crosslinking agent are used, it is preferable that they also contain substantially no solvent.

The acrylic pressure-sensitive adhesive composition of the present invention further comprises, as a filler, inorganic substances such as calcium carbonate, aluminum hydroxide, silica, clay, talc, titanium oxide, glass balloons, shirasu balloons, ceramic balloons and the like. Inorganic hollow bodies, organic materials such as nylon beads, acrylic beads, and silicon beads, organic hollow bodies such as vinylidene chloride balloons and acrylic balloons, foaming agents, dyes, pigments, silane coupling agents, polymerization inhibitors, stabilizers, etc. The additives to be blended with may be blended.

Further, the composition used in the present invention is water,
Substantially free of aqueous or organic solvents,
The component (b), the component (c-1) or the component (c-2), the component (d),
The component (e) and other components are dissolved or dispersed in the acrylic monomer (a). The composition used in the present invention comprises the above-mentioned (a) acrylic monomer, (b) high molecular weight polymer, and (c-1) high Tg low molecular weight polymer or, if necessary,
(c-2) 5 to 300 parts by weight of low Tg low molecular weight polymer, (d)
Although it can be prepared by mixing the photopolymerization initiator, (e) a crosslinking agent, and optionally other components,
Unreacted monomer remaining when preparing the polymer
(a) It can be used as an acrylic monomer.
That is, for example, the above (b) high molecular weight polymer can be partially polymerized without using a solvent, and an unreacted monomer can be used as the component (a) during this partial polymerization. The reaction product (acrylic syrup) thus obtained by partial polymerization is an acrylic monomer solution or dispersion containing a predetermined amount of high molecular weight polymer. Then, if necessary, a predetermined amount of (c-1) high Tg low molecular weight polymer or (c-2) low polymer is added to the obtained acrylic monomer solution or dispersion.
The composition used in the present invention can be obtained by adding and mixing the Tg low molecular weight polymer, (d) photopolymerization initiator, (e) crosslinking agent, and optionally other components.

The composition having the above composition is
The component (b), the component (c-1) or the component (c-2), the component (d) and the component (e) are dissolved or dispersed in the monomer which is the component (a), and a so-called solvent is substantially used. Not contained in. When the viscosity of the composition having the above composition is measured at 25 ° C., the viscosity is usually in the range of 100 to 100000 cps, preferably 500 to 50,000 cps, and the composition is a viscous liquid. The liquid having such a viscosity can be coated on the support using a conventional coating device.

Next, the composition prepared as described above is coated on a support. As the support used here, a polyolefin film, a polyester film,
Examples thereof include paper, metal foil, cloth, non-woven fabric, silicone-treated polyester film, and silicone-treated paper. The acrylic pressure-sensitive adhesive composition of the present invention is applied to the surface of such a support. The coating thickness of this composition is usually 0.1.
01 to 10.0 mm, preferably 0.01 to 5.0 mm
Is.

The composition thus coated on the surface of the support is polymerized on this support. In the present invention, the composition coated on the surface of the support is reacted at a temperature within the range of 0 to 10 ° C. Since the composition applied to the surface of the support in the present invention contains substantially no solvent, when the applied composition begins to react, the reaction proceeds at once because it is bulk polymerization. In addition, as the reaction temperature increases, the activity of the surface of the composition applied to the surface of the support increases, and the desired reaction does not proceed on the surface of the composition that comes into contact with oxygen in the air. The component formed in the above may be different from the components in other portions, and the characteristics of the pressure-sensitive adhesive layer may differ in the thickness direction of the pressure-sensitive adhesive layer. For this reason, in the present invention, the reaction temperature of the composition coated on the surface of the support is controlled to a very low temperature as described above to carry out the polymerization reaction under mild conditions. In addition, in order to lower the polymerization reaction temperature of the composition applied to the surface of the support below 0 ° C., expensive equipment is required, and at a temperature below 0 ° C., the reaction time becomes long. Not efficient or practical. Further, if the temperature exceeds 10 ° C., the chain transfer rate increases, so that a high molecular weight polymer cannot be efficiently obtained. Furthermore, since the reaction activity of the composition coated on the support also becomes high, the composition other than the planned polymerization reaction proceeds on the surface of the composition when the composition on the coated surface comes into contact with oxygen. There is a possibility that the possibility increases and the uniformity of the pressure-sensitive adhesive layer in the obtained pressure-sensitive adhesive tape is impaired.

In the present invention, a photopolymerization reaction is employed for the reaction of the composition coated on the support as described above. In the present invention, visible light or ultraviolet light can be used in the polymerization reaction of this composition. That is, the composition used in the present invention contains a photopolymerization initiator, and the type of irradiation light can be specified by the type of the photopolymerization initiator. Particularly in the present invention, it is preferable that the composition coated on the surface of the support is subjected to a polymerization reaction by using ultraviolet rays which do not require strict light-shielding equipment when preparing the composition. As the ultraviolet rays preferably used here, a normal ultraviolet ray irradiation device or a so-called black light can be used. When using such ultraviolet rays, the irradiation time is usually 10 to 600 seconds,
It is preferably 10 to 480 seconds. It should be noted that such irradiation of ultraviolet rays may be continuous or intermittent. In the case of intermittent UV irradiation, the irradiation time is
It is the total of intermittent UV irradiation time.

Thus, the acrylic pressure-sensitive adhesive tape produced by the method of the present invention is extremely low in temperature of the composition on the support during the polymerization reaction is controlled to be as low as 0 to 10 ° C. It is possible to produce a very homogeneous acrylic adhesive tape. Moreover, by using the low Tg low molecular weight polymer (c-2) as the low molecular weight polymer, it is excellent in the effect of relaxing the internal stress generated inside the acrylic pressure sensitive adhesive sheet, and this acrylic pressure sensitive adhesive sheet can be used for large area liquid crystal devices. Even in the case of using, the internal stress is eliminated in the acrylic pressure-sensitive adhesive sheet of the present invention, so that the light leakage phenomenon in the main part of the liquid crystal element can be effectively prevented.

When the high Tg low molecular weight polymer (c-1) is used, the acrylic pressure-sensitive adhesive tape of the present invention exhibits excellent heat resistance and plastic adhesion. Further, when the low molecular weight polymer is not blended, there are few substances whose characteristics change due to heat, so that an acrylic pressure-sensitive adhesive tape having particularly excellent heat resistance can be obtained.

[0045]

According to the method for producing an acrylic pressure-sensitive adhesive tape of the present invention, (a) an acrylic monomer containing a (meth) acrylic acid ester as a main component, a predetermined amount of (b) (a high molecular weight polymer, and if necessary, A predetermined amount of (c-1) high Tg low molecular weight polymer, or (c-2) low Tg low molecular weight polymer, and a predetermined amount of
(d) A photopolymerization initiator and a predetermined amount of (e) a cross-linking agent are contained to prepare a composition containing substantially no solvent, and the composition is drowned on a support, and the composition is By reacting this composition while maintaining the temperature within the range of 0 to 10 ° C., an acrylic pressure-sensitive adhesive tape exhibiting excellent adhesive strength, high holding power, and excellent curved surface adhesiveness is manufactured. be able to. In particular, by performing the photopolymerization reaction at a low temperature, the composition coated on the surface of the support becomes less susceptible to factors such as oxygen that inhibit the progress of the reaction, and to produce an adhesive tape having desired characteristics. You can

The acrylic pressure-sensitive adhesive tape thus obtained can be suitably used especially for optical applications, for example, as an acrylic pressure-sensitive adhesive tape for sticking a polarizing plate on a transparent substrate in a liquid crystal element. Further, in the acrylic pressure-sensitive adhesive tape of the present invention, the pressure-sensitive adhesive layer does not substantially contain a solvent, a solvent removing step is not required when manufacturing the pressure-sensitive adhesive, and the environment is not polluted by the solvent. Further, the acrylic pressure-sensitive adhesive tape of the present invention does not contain a solvent as described above, the adhesive obtained from this composition also does not contain a solvent, and the pressure-sensitive adhesive is substantially It also does not contain low-boiling substances. Therefore, the offensive odor such as the residual organic solvent odor peculiar to the conventional pressure-sensitive adhesive is small.

[0047]

EXAMPLES Next, the acrylic pressure-sensitive adhesive tape and the method for producing the same of the present invention will be specifically described by showing examples, but the present invention is not specifically limited by these.

[0048]

[Production Example 1] Preparation of acrylic syrup A-1 A 2-liter four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube and a cooling tube was charged with 2-ethylhexyl acrylate (hereinafter referred to as 2-EHA). ): 959 g, acrylic acid (hereinafter referred to as AA): 40 g, 2-hydroxyethyl acrylate: 1 g, n-dodecyl mercaptan: 0.1 g
While replacing the air in the flask with nitrogen,
Heated to 0 ° C.

Then, as a polymerization initiator, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile): 0.0
25 g was added under stirring and mixed uniformly. After the polymerization initiator was added, the temperature of the reaction system rose, but when the polymerization reaction was continued without cooling, the temperature of the reaction system reached 119 ° C. and then gradually began to drop. 2-EHA: 192 g and AA: 8 g were added, and the temperature of the reaction system was cooled to 110 ° C. Furthermore, forced cooling with a water bath was performed to obtain an acrylic syrup A-1. This syrup contains a monomer at a concentration of 71% and a polymer at a concentration of 29%, and the weight-average molecular weight (Mw) of the polymer component in the obtained acrylic syrup A-1 measured by GPC.
Was 720,000.

[0050]

[Production Example 2] Preparation of acrylic syrup A-2 Butyl acrylate (hereinafter referred to as BA): 1900 g, A
A: 50 g, 2-HEA: 50 g, and 2-methyl-1- [4-
(Methylthio) phenyl] -2-morpholinopropanone-1
(Ciba Geigy Co., Ltd., trade name: Irgacure 90
7): 0.03 g was charged into a photopolymerization device, and the strength was 56 W
/ M ² ultraviolet rays were intermittently irradiated to obtain an acrylic syrup A-2. This acrylic syrup A-2 contained a monomer at a concentration of 85% by weight and a polymer at a concentration of 15% by weight, and the weight average molecular weight of the polymer component in the obtained acrylic syrup A-2 was measured by GPC. (Mw) was 950,000.

[0051]

[Production Example 3] Preparation of low Tg low molecular weight polymer L-1 A 2-liter 4-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introducing tube and a cooling tube was charged with 2-EHA: 980.
g, AA: 20 g, and n-dodecyl mercaptan: 100 g as a molecular weight modifier were charged, and the mixture was heated to 60 ° C. while replacing the air in the flask with nitrogen gas.

Then, as a polymerization initiator, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile): 0.0
5 g was put under stirring and mixed uniformly. After adding the polymerization initiator, the temperature of the reaction system rose, but when the polymerization reaction was continued without cooling, the temperature of the reaction system reached 110 ° C.,
After that, it began to fall gradually. The temperature in the system is 6 due to the water bath
It was forcibly cooled to 0 ° C. After forced cooling, further 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile):
0.05 g was added under stirring and mixed uniformly. After the second addition of the initiator, the temperature of the reaction system rose, but when the polymerization reaction was continued without cooling, the temperature of the reaction system was 105 ° C.
Reached Then, the temperature of the reaction system was forcibly cooled to 75 ° C. with a water bath.

Further, 0.1 g of dimethyl 2,2'-azobis (2-methylpropionate) was added. When the temperature of the reaction system rose, but the polymerization reaction was continued without cooling,
The temperature of the reaction system reached 120 ° C. The temperature of the reaction system was cooled to 110 ° C. with a water bath. Continuing, polymerization initiator 1,
1'-Azobis (cyclohexane-1-carbonitrile): 1.
After 5 g was added under stirring to carry out a polymerization reaction for 2 hours, the reaction system was cooled to room temperature in a water bath to obtain a low Tg low molecular weight polymer L-1.

The obtained low Tg low molecular weight polymer L-1 had a weight average molecular weight (Mw) of 3,100 and a glass transition temperature (Tg) of -68 ° C.

[0055]

Production Example 4 Preparation of Low Tg Low Molecular Weight Polymer L-2 In Production Example 3, 2-EHA: 980 g, AA: 20 g
And n-dodecyl mercaptan as a molecular weight regulator: 1
Low Tg low molecular weight polymer L-2 was obtained in the same manner except that BA: 900 g, methoxyethyl acrylate: 100 g and α-methylstyrene dimer: 100 g as a molecular weight modifier were used instead of 00 g.

The obtained low Tg low molecular weight polymer L-2 had a weight average molecular weight (Mw) of 7,000 and a glass transition temperature (Tg) of -50 ° C.

[0057]

[Production Example 5] Preparation of high-Tg low-molecular weight polymer L-3 In a 4-necked flask having a capacity of 2 liters equipped with a stirrer, a thermometer, a nitrogen gas introduction tube and a cooling tube, isobutyl methacrylate (hereinafter referred to as i-BMA ): 1200 g and n-dodecyl mercaptan: 96 g as a molecular weight modifier were charged, and the air in the flask was heated to 70 ° C. while replacing the air with nitrogen.

Then, 3.6 g of cumyl peroxyneodecanoate as a polymerization initiator was added under stirring to uniformly mix them. After the polymerization initiator was added, the temperature of the reaction system rose, but when the polymerization reaction was continued without cooling, the temperature of the reaction system reached 110 ° C., and then gradually began to drop.
The temperature in the system was forcibly cooled to 70 ° C. with a water bath. After forced cooling, cumyl peroxyneodecanoate:
3.6 g was added with stirring to uniformly mix. After the second addition of the initiator, the temperature of the reaction system rose, but when the polymerization reaction was continued without cooling, the temperature of the reaction system reached 105 ° C. Then, the temperature of the reaction system was forcibly cooled to room temperature with a water bath.

Further, 1000 g of the obtained partial polymer was placed in a stainless steel container, 20 g of cumylperoxy neodecanoate and 20 g of t-hexylperoxy 2-ethylhexanoate were added and mixed well, and then 120 ° C.
High Tg by polymerizing for 1 hour in a heat dryer
A low molecular weight polymer L-3 was obtained. The obtained high Tg low molecular weight polymer L-3 had a weight average molecular weight (Mw) of 4,900 and a glass transition temperature (Tg) of 48 ° C.

[0060]

Example 1 Acrylic syrup A obtained in Production Example 1
-1 of 100 g, 2-hydroxy-2 as a photopolymerization initiator
-Methyl-1-phenyl-propan-1-one (trade name: Darocur 1173; manufactured by Ciba Geigy): 0.15 g,
As a cross-linking agent, N, N, N ', N'-tetraglycyl-m-xylylenediamine (trade name: Tetrad X; manufactured by Mitsubishi Gas Chemical Co., Inc.): 0.05 g was mixed to prepare an acrylic adhesive composition. The product E-1 was prepared. This composition is shown in Table 1.

This pressure-sensitive adhesive composition E-1 was prepared to have a thickness of 25 μm.
It was applied onto a polyester film which had been subjected to a peeling treatment of m. The maximum strength of this is 40 W / m in a nitrogen gas atmosphere.
Light was irradiated from a high-pressure mercury lamp adjusted to ² to carry out photopolymerization while keeping the temperature at 5 ° C. The polymerization rate at this time was 99.8% by weight. Thus, an acrylic adhesive sheet was obtained. Table 2 shows the evaluation test results of the obtained pressure-sensitive adhesive sheet.

The evaluation test method for the obtained pressure-sensitive adhesive sheet is as follows. << Optical Property Evaluation Test of Adhesive Sheet >> Preparation of Test Piece The adhesive sheet was transferred to a three-layer laminated polarizing plate made of triacetyl cellulose / polyvinyl alcohol / triacetyl cellulose and cut into 150 mm × 200 mm to obtain a test piece. did. Durability test A test piece was attached to one side of a glass plate, 90 ° C, DRY for 1000 hours, and 60 ° C, 90% RH (relative humidity).
The appearance change of the test piece was observed under each condition for 100 hours. The evaluation was performed in the following three stages. ○: No change such as floating, peeling, foaming, etc. is observed. Δ: A slight change in any of floating, peeling and foaming is observed. X: Changes such as floating, peeling, and foaming are observed. Light Leakage Resistance Test Specimens were attached to both sides of a glass plate so as to form a crossed Nicol, and 90 hours at DRY for 1000 hours, and 60
Under each condition of 100 ° C. and 90% RH (relative humidity), the change in appearance of the test piece was observed. The evaluation was performed in the following three stages. ○: No light leakage is seen. B: Light leakage is slightly observed in the outer peripheral portion of the test piece. X: Light leakage is seen.

[0063]

Examples 2 to 8 In Example 1, pressure sensitive adhesive compositions E-2 to E-8 were prepared in the amounts shown in Table 1 for the respective components. In addition, silane coupling agent (trade name: KBM-403, manufactured by Shin-Etsu Polymer Co., Ltd.) is 0.2 in E-3.
It is blended by weight.

Using the adhesive compositions E-1 to E-8,
The conditions were set as shown in Tables 2, 3 and 4 to obtain an acrylic pressure-sensitive adhesive sheet for optical members. The evaluation test results of the obtained pressure-sensitive adhesive sheet are shown in Tables 2, 3 and 4.

[0065]

Comparative Examples 1-10 E-1, E-3, prepared as described above
Using E-4, E-7 and E-8, the conditions were set as shown in Tables 2, 3 and 4 to obtain acrylic pressure-sensitive adhesive sheets for optical members. The evaluation test results of the obtained pressure-sensitive adhesive sheet are shown in Tables 2, 3 and 4.

[0066]

[Table 1]

[0067]

[Table 2]

[0068]

[Table 3]

[0069]

[Table 4]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08G 59/40 C08G 59/40 4J036 C09J 4/00 C09J 4/00 4J040 163/00 163/00 175/04 175/04 G02B 5/30 G02B 5/30 // C08F 20/10 C08F 20/10 F term (reference) 2H049 BB52 BC22 4J004 AA01 AA10 AB01 AB05 AB07 CA02 CA04 CA06 CA08 CB01 CB02 CC02 EA06 FA05 FA10 GA01 4J011 CA01 CA03 CA05 CA08 CC04 CC09 CC10 PA69 PB38 PC02 PC08 4J026 AA24 AA31 AA38 AA43 AA45 AA46 AA47 AA48 AA49 AA50 AA53 AA54 AA55 AA59 AA61 AA63 AA76 AC33 AC34 BA06 BA36 BA36 BA50 BA35 BA35 BA35 BA35 BA31 BA32 BA31 BA31 BA32 BA31 BA32 BA31 BA31 BA32 BA31 BA32 BA31 BA32 GA06 4J034 BA03 DA01 DA02 DA03 DA06 DB03 DB07 DP02 DP03 DP11 DP16 DP17 DP18 HA01 HA06 HA07 HA08 HB07 HC03 HC12 HC13 HC17 HC22 HC46 HC52 HC61 HC64. MB03 NA17 NA19 PA23 PA30 PA32

Claims (8)

[Claims] 1. An acrylic monomer containing (a) a (meth) acrylic acid ester as a main component, and (b) a (meth) acrylic acid ester component unit as a main constituent unit with respect to 100 parts by weight of the acrylic monomer. And 5 to 200 parts by weight of a high molecular weight polymer having a weight average molecular weight of 50,000 or more, and (c-1) (meth) acrylic acid ester component unit as a main constitutional unit if necessary, and a weight average molecular weight of 20,000 or less. And a high Tg low molecular weight polymer having a glass transition temperature (Tg) in the range of 25 to 200 ° C. or a (c-2) (meth) acrylic acid ester component unit as a main constitutional unit, and a weight average molecular weight of 20,000. 5 to 300 parts by weight of a low Tg low molecular weight polymer having a glass transition temperature (Tg) in the range of −85 to 20 ° C., and (d) a photopolymerization initiator of 0.01 to 5 parts by weight. , (E) Crosslink A composition containing a preparative cast onto a support, 0
A method for producing an acrylic pressure-sensitive adhesive tape, which comprises reacting the composition at a temperature within the range of -10 ° C. 2. The method for producing an acrylic pressure-sensitive adhesive tape according to claim 1, wherein the acrylic pressure-sensitive adhesive tape is an acrylic pressure-sensitive adhesive tape for optical members. 3. The method for producing an acrylic pressure-sensitive adhesive tape according to claim 1, wherein the glass transition temperature of the high molecular weight polymer (b) is in the range of −85 to 0 ° C. 4. The acrylic according to claim 1, wherein the crosslinking agent (e) is at least one compound selected from the group consisting of polyfunctional epoxy compounds and polyfunctional isocyanate compounds. Manufacturing method of adhesive tape. 5. A support, and a pressure-sensitive adhesive layer formed by maintaining the temperature of the following composition drowned on the support within the range of 0 to 10 ° C. to cause a reaction. An acrylic adhesive tape comprising: (a) an acrylic monomer containing a (meth) acrylic acid ester as a main component, and (b) a (meth) acrylic acid ester component unit as a main component based on 100 parts by weight of the acrylic monomer. 5 to 200 parts by weight of a high molecular weight polymer having a weight average molecular weight of 50,000 or more as a constitutional unit, and if necessary, a (c-1) (meth) acrylic acid ester component unit as a main constitutional unit, and a weight average molecular weight of 20,000. Or less, a high Tg low molecular weight polymer having a glass transition temperature (Tg) in the range of 25 to 200 ° C., or (c-2) (meth)
Acrylic ester component unit as the main constituent unit, the weight average molecular weight is 20,000 or less, the glass transition temperature (T
g) contains 5 to 300 parts by weight of a low Tg low molecular weight polymer having a temperature range of −85 to 20 ° C., (d) a photopolymerization initiator of 0.01 to 5 parts by weight, and (e) a crosslinking agent And a composition containing substantially no solvent. 6. The acrylic pressure-sensitive adhesive tape according to claim 5, wherein the glass transition temperature of the high molecular weight polymer (b) is in the range of 0 to −85 ° C. 7. The acrylic according to claim 5, wherein the crosslinking agent (e) is at least one compound selected from the group consisting of polyfunctional epoxy compounds and polyfunctional isocyanate compounds. System adhesive tape. 8. The acrylic pressure-sensitive adhesive tape according to claim 5, wherein the acrylic pressure-sensitive adhesive tape is an acrylic pressure-sensitive adhesive tape for optical members.