JP2003049128A - Method for producing acrylic adhesive sheet for optical member and acrylic adhesive sheet for optical member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an acrylic adhesive sheet for an optical member and to obtain an adhesive sheet having excellent adhesive property, especially suitable for optical uses by the method. SOLUTION: This method for producing the acrylic adhesive sheet comprises casting a composition comprising (a) 100 pts.wt. of an acrylic monomer consisting essentially of a (meth)acrylic acid ester, (b) 5-200 pts.wt. of a high- molecular weight polymer composed of a (meth)acrylic acid ester component unit as a constituent unit and having >=50,000 Mw, (c) 10-200 pts.wt. of a polymer composed of a (meth)acrylic acid ester component unit as a main constituent unit and having a low Tg and a low molecular weight of <=20,000 Mw and <=20 deg.C Tg, (d) 0.01-5 pts.wt. of a photopolymerization initiator and (e) a crosslinking agent but not a solvent on a substrate and irradiating the cast composition with ultraviolet light rays dividedly at three- or multistage. This adhesive sheet for an optical member is obtained by the method.

Description

Detailed Description of the Invention

[0001]

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

[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 the adhesive agent prepared by emulsion polymerization or solution polymerization in the state of being emulsion-dispersed or dissolved in the solute is used. It is compounded. 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 that it is possible to polymerize an acrylic monomer without using a reaction solvent. Although it has been known (bulk polymerization), it is extremely difficult to control the reaction in the polymerization of acrylic monomers that is carried out without using such a reaction solvent, and it is necessary to selectively produce a polymer having certain properties. Because I couldn't. Further, the pressure-sensitive adhesive and the polymer-type additive produced by solution polymerization or emulsion polymerization can be easily produced as a uniform composition by mixing with a reaction solvent.

However, when the adhesive composition or emulsion type adhesive composition containing such a solvent is used for bonding, a step of removing the solvent is required, and for example, water having a large latent heat of vaporization is 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, there are JP-A-50-87129 and JP-A-50-102635, and these publications (meta) A mixture obtained by adding these (co) polymers and a polymerization initiator to a mixture of an acrylic acid alkyl ester and a vinyl monomer having a specific polar group is applied to a support sheet, and heat-polymerized. A method for producing a pressure-sensitive adhesive tape is disclosed. And Japanese Patent Laid-Open No. Sho 50
In Japanese Patent Publication No. 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, and JP-A-5-29129 discloses the method.
In JP-A 0-102635, a release sheet or belt is placed 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.

Further, Japanese Patent Laid-Open No. 2-60981 discloses that
A liquid material obtained by adding a photopolymerization initiator to a vinyl-based monomer containing an acrylic acid alkyl ester as a main component is applied or impregnated on a base material and irradiated with ultraviolet rays having a strength of 1 to 300 W / m ² to obtain at least 90% by weight. A method for producing an acrylic pressure-sensitive adhesive sheet for an optical member is disclosed in which a polymerization reaction is performed, and then ultraviolet rays having an intensity higher than that is irradiated to complete the polymerization reaction.
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 sheet for optical members, which has excellent pressure-sensitive adhesive strength and cohesive strength by photopolymerization.
A further object of the present invention is to provide an acrylic pressure-sensitive adhesive sheet for optical members, which has excellent adhesive properties such as adhesive force and cohesive force due to photopolymerization.

Another object of the present invention is to provide an acrylic pressure-sensitive adhesive sheet for optical members, 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 sheet for optical members of the present invention comprises: (a) an acrylic monomer containing a (meth) acrylic acid ester as a main component, and 100 parts by weight of the acrylic monomer. (b) The main component is the (meth) acrylic acid ester component unit, and the weight average molecular weight is 500.
5 to 200 parts by weight of a high molecular weight polymer of 00 or more and, if necessary, a (c) (meth) acrylic acid ester component unit as a main constituent unit, a weight average molecular weight of 20,000 or less, and a glass transition temperature (Tg). Low T below 20 ℃
g containing 10 to 200 parts by weight of a low molecular weight polymer, 0.01 to 5 parts by weight of (d) a photopolymerization initiator, and (e) a crosslinking agent,
The composition containing substantially no solvent is drowned on the support,
It is characterized in that the composition is reacted by irradiating the composition with ultraviolet rays changed in three or more stages in multiple stages.

Further, the acrylic pressure-sensitive adhesive sheet for optical members of the present invention comprises a support and the above-mentioned (a) sprinkled on the support.
To (e) the composition containing substantially no solvent and having a pressure-sensitive adhesive layer obtained by reacting the composition by irradiating the composition with ultraviolet rays changed in three stages or more in multiple stages . In the present invention, the composition drowned on the support is irradiated with ultraviolet rays in three or more stages in multiple stages.
The intensity of the ultraviolet rays irradiated at this time is 500 to 5000
After irradiation under the condition of (W / m ² ), 1 or more and less than 500 (W / m ²
m ² ) and then 500-10,000 (W /
It is preferable to adjust the ultraviolet irradiation energy so that the irradiation becomes strong, weak or strong, such as irradiation under the condition of m ² ).

[0015]

DETAILED DESCRIPTION OF THE INVENTION Next, the acrylic pressure-sensitive adhesive sheet for an optical member of the present invention will be specifically described along with its manufacturing method. The acrylic pressure-sensitive adhesive sheet for optical members of the present invention is
(a) Acrylic monomer, (b) high molecular weight polymer, optionally (c) low Tg low molecular weight polymer, (d) photopolymerization initiator, (e) contains a cross-linking agent, substantially It is produced by photopolymerization on a support under a specific temperature condition using a composition containing no solvent.

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 a weight average molecular weight of 5
0000 or more, preferably 100,000 to 200,000
It is an acrylic polymer in the range of 0. 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 higher glass transition temperature (Tg) than low molecular weight polymers. That is, the glass transition temperature (Tg) of the high molecular weight polymer (b) is usually −85 to 0 ° C., preferably −85 ° C.
85 to -5 ° C.

The high molecular weight polymer (b) is added in an amount of 5 to 200 parts by weight, preferably 10 to 150 parts by weight, based on 100 parts by weight of the acrylic monomer (a). The low Tg low molecular weight polymer (c) optionally 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 10,000 or less. And particularly in the range of 10,000 to 2000, and the glass transition temperature (Tg) of this acrylic polymer is 20 ° C. or lower,
It is preferably in the range of −85 to 0 ° C. This (c) Low Tg
When the weight average molecular weight of the low molecular weight polymer exceeds 20,000, the stress relaxation property of the pressure-sensitive adhesive layer in the pressure-sensitive adhesive tape obtained using the composition of the present invention becomes poor. The (c) low Tg low molecular weight polymer as described above is formed by polymerizing a (meth) acrylic acid ester with 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 and 1 to 20 carbon atoms are used.
(Meth) acrylic acid alkyl ester with alcohol having alkyl group of (meth) acrylic acid and carbon number 3 to
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. Among such (meth) acrylic acid esters, in the present invention, preferably (meth) acrylic acid alkyl ester having an alkyl group having 1 to 4 carbon atoms and / or an alicyclic alcohol having 3 to 14 carbon atoms and (meth ) Use of esters with acrylic acid and / or with benzyl alcohol.

The (c) low Tg low molecular weight polymer 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 (c) low Tg low molecular weight polymer used in the present invention is obtained by converting the repeating unit ((meth) acrylic acid ester component unit) derived from the above (meth) acrylic acid ester into monomer conversion. 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight
It has the above amount.

The (c) low Tg low molecular weight polymer used in the present invention is derived from a monomer copolymerizable with a (meth) acrylic acid ester in addition to the above-mentioned (meth) acrylic acid ester component unit. It may have a repeating unit
Examples of such monomers include (meth) acrylic acid,
Alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate; Salts of (meth) acrylic acid alkali metal salts and the like; ethylene glycol di (meth) acrylic acid ester, diethylene glycol di (meth) acrylic acid ester, triethylene glycol di (meth) acrylic acid ester, polyethylene glycol di ( Meta)
Di (meth) acrylates such as acrylic acid ester, di (meth) acrylic acid ester of propylene glycol, di (meth) acrylic acid ester of dipropylene glycol, di (meth) acrylic acid ester of tripropylene glycol ) Acrylic ester;
Poly (meth) acrylic acid ester such as trimethylolpropane tri (meth) acrylic acid ester; (meth)
Acrylonitrile; vinyl acetate; vinylidene chloride; vinyl halide compounds such as 2-chloroethyl (meth) acrylate; 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl- Oxazoline group-containing polymerizable compound such as 2-oxazoline; (meth)
Acryloylaziridine, aziridine group-containing polymerizable compounds such as (meth) acrylic acid-2-aziridinylethyl; allyl glycidyl ether, (meth) acrylic acid glycidyl ether, (meth) acrylic acid glycidyl ether, (meth) acrylic acid -2-Epoxy group-containing vinyl monomer such as ethyl glycidyl ether; 2- (meth) acrylic acid-2-hydroxyethyl, -2-hydroxypropyl acrylate, mono (meth) acrylic acid with polypropylene glycol or polyethylene glycol ester,
A hydroxyl group-containing vinyl compound such as an adduct of lactones and 2-hydroxyethyl (meth) acrylate;
Fluorine-containing vinyl monomers such as fluorine-substituted methacrylic acid alkyl esters and fluorine-substituted acrylic acid alkyl esters; unsaturated carboxylic acids such as itaconic acid, crotonic acid, maleic acid, and fumaric acid (except (meth) acrylic acid) , Their salts and their (partial) ester compounds and acid anhydrides; 2-chloroethyl vinyl ether,
Reactive halogen-containing vinyl monomers such as monochlorovinyl acetate; amide group-containing vinyl monomers such as methacrylamide, N-methylolmethacrylamide, N-methoxyethylmethacrylamide, and N-butoxymethylmethacrylamide; vinyltri Organosilicon group-containing vinyl compound monomers such as methoxysilane, γ-methacryloxypropyltrimethoxysilane, allyltrimethoxysilane, trimethoxysilylpropylallylamine, and 2-methoxyethoxytrimethoxysilane; other vinyl groups are polymerized. Examples thereof include macromonomers having a radically polymerizable vinyl group at the terminal of the monomer. Such monomers can be copolymerized with the above-mentioned (meth) acrylic acid ester alone or in combination.

In the usual case, this (c) low Tg low molecular weight polymer is used in an amount of 10 to 200 parts by weight, preferably 1 part by weight, relative to 100 parts by weight of the (a) acrylic monomer.
Used in an amount of 5 to 150 parts by weight. Such (c) low
By using a Tg low molecular weight polymer, the resulting acrylic pressure-sensitive adhesive sheet for optical members will have excellent stress relaxation properties, and the adhesive performance at the outer periphery of the adhesive surface will decrease even if the adhesive area increases. Less is. In the case where such a sticking area is large, the property that the sticking performance does not change in the outer peripheral portion of the sticking surface is particularly important as a pressure-sensitive adhesive sheet 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 size of the liquid crystal element increases, the stress at the end edge where the transparent substrate and the polarizing plate are adhered increases, The phenomenon of light leakage, which causes light to leak due to the distortion of the light, is likely to occur. Such internal stress can be efficiently relaxed by using (c) a low Tg low molecular weight polymer.

The composition used in the present invention has the above (a)
It contains a component, a component (b), a component (c) if necessary, a photopolymerization initiator (d) and a crosslinking agent (e). 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 [for example, manufactured by Ciba Geigy,
Product name: Darocur 2959], α-hydroxy-α, α'-
Dimethylacetophenone [for example, manufactured by Ciba Geigy, trade name: Darocur 1173], methoxyacetophenone,
Acetophenone-based photopolymerization of 2,2-dimethoxy-2-phenylacetone [eg Ciba Geigy, trade name: Irgacure 651], 2-hydroxy-2-cyclohexylacetophenone [Ciba Geigy, trade name: Irgacure 184] Initiators; ketal-based photopolymerization initiators such as benzyl dimethyl ketal; and other photopolymerization initiators such as halogenated ketones, acylphosphinoxides, and acylphosphanates.

The photopolymerization initiator (d) is used in an amount of 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 is a compound capable of forming a cross-linking structure between the components formed by polymerizing the component (a), the component (b), and optionally the component (c).

Examples of such a cross-linking agent include a compound having an epoxy group (polyfunctional epoxy compound), 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 crosslinking agent is usually used in an amount of 0.01 to 5 parts by weight, based on 100 parts by weight of the acrylic monomer (a).
It is preferably blended in an amount within the range of 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 may be further blended with additives such as an ultraviolet absorber, an antioxidant, a silane coupling agent, a dye, a pigment, a polymerization inhibitor and a stabilizer.

Further, the composition used in the present invention comprises water,
Substantially free of aqueous or organic solvents,
The above component (b), if necessary component (c), component (d), component (e),
Still other components are dissolved or dispersed in (a) the acrylic monomer. The composition used in the present invention, (a) the acrylic monomer, (b) a high molecular weight polymer,
It may be prepared by mixing (c) 10 to 200 parts by weight of a low Tg low molecular weight polymer, (d) a photopolymerization initiator, (e) a cross-linking agent, and optionally other components. However, the unreacted monomer that remains when the above polymer is prepared can be used as the (a) 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, the resulting acrylic monomer solution or dispersion, if necessary (c) low Tg low molecular weight polymer, (d) photopolymerization initiator, (e) cross-linking agent, and further optionally other components. The composition used in the present invention can be obtained by adding and mixing.

The composition having the above composition is
The component (b), and optionally the components (c), (d) and (e), are dissolved or dispersed in the monomer which is the component (a), and the so-called solvent is not substantially contained. 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.

Then, the composition prepared as described above is coated on a support. As the support used here, a polyolefin film, a polyester film,
Mention may be made of silicone-treated polyester films. 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 0.
It is 001 to 0.1 mm.

The composition thus coated on the surface of the support is polymerized on this support. The composition used in the present invention (the composition applied to the surface of the support) contains (d) a photopolymerization initiator as a reaction initiator, and the composition is irradiated with a predetermined light beam. This initiates photopolymerization. However, in the present invention, not only the irradiation of light rays, but also the irradiation of ultraviolet rays is performed in three or more stages. By irradiating with ultraviolet light in three or more stages in this manner, the polymerization reaction of the composition on the support does not rapidly proceed, and the composition or composition distribution of the obtained polymer becomes uniform, and the entire sheet is As a result, it is possible to manufacture a homogeneous sheet having uniform properties. The irradiation conditions of the ultraviolet light at this time are such that, in the light irradiation of the first step, the maximum intensity of light is usually 500 to 5000 (W / m ² ), preferably 50.
Set it to 0 to 3000 (W / m ² ). If the maximum intensity of ultraviolet light to be irradiated in this first step is less than the lower limit value, the ultraviolet irradiation time may be long and productivity may not be improved. If the maximum intensity exceeds the upper limit value, a large amount of low molecular weight The formation of polymer significantly reduces the adhesive properties. The UV irradiation time in the first step is usually 0.01 to 5 seconds. That is, in the first step of UV irradiation, the polymerization reaction rate of the applied composition is usually 0.01 to 10% by weight, preferably 0.1 to 5% by weight.
UV irradiation conditions are set so that When the polymerization reaction rate by the ultraviolet irradiation in the first step is less than the above lower limit value, the effect of eliminating the influence of dissolved oxygen to improve productivity becomes low, and the polymerization reaction rate remarkably exceeds the upper limit value. If it exceeds the range, the adhesive performance of the adhesive sheet, particularly the heat resistance, is deteriorated.

In the present invention, the ultraviolet irradiation in the second step has a maximum light intensity of usually 1 or more and less than 500 (W / m).
² ), preferably 1 to 450 (W / m ² ).
If the maximum intensity of ultraviolet rays in the second stage is less than the lower limit value, the irradiation time of ultraviolet rays may be long and the productivity may deteriorate, and if the maximum intensity of ultraviolet rays deviates from the upper limit value and is high,
A high-performance pressure-sensitive adhesive sheet may not be obtained due to the formation of a low molecular weight polymer. The UV irradiation time in the second step is usually 10 to 360 seconds, preferably,
It is 10 to 300 seconds. That is, in the second-stage ultraviolet irradiation, the ultraviolet irradiation conditions are set so that the polymerization reaction rate of the applied composition is usually within the range of 90 to 95% by weight. If the polymerization reaction rate in the second step is less than the above lower limit, the amount of low-molecular weight polymer produced in the ultraviolet irradiation step in the third step may increase, so that the adhesive performance, particularly the heat resistance performance may decrease. Further, if the polymerization reaction rate deviates from the upper limit value and becomes high, the ultraviolet irradiation time becomes long and the productivity may decrease.

Further, in the present invention, the ultraviolet irradiation in the third step is performed so that the maximum intensity of light is usually 500 to 10,000.
(W / m ² ), preferably 1000 to 5000 (W / m ² ).
m ² ). If the maximum intensity of ultraviolet rays in the third step is less than the lower limit value, the time required to complete the reaction may be long and productivity may decrease, and the maximum intensity of ultraviolet rays deviates from the upper limit value and is high. The risk of damage to the adhesive surface and the support due to the radiant heat from the ultraviolet lamp increases. The UV irradiation time in the third step is usually 0.1 to 60 seconds, preferably 1 to 30 seconds.
Seconds. That is, in the ultraviolet irradiation of the third step, the ultraviolet irradiation conditions are set so that the polymerization reaction rate of the applied composition is usually 99% by weight or more, preferably 99.5% by weight or more. If the polymerization reaction rate in the third stage is lower than the lower limit value, the presence of residual monomers lowers the adhesive performance such as cohesive force and increases the odor, which is not practical.

Further, even when the ultraviolet irradiation step is performed in the fourth step or more, the irradiation conditions can be set according to the above steps. In the present invention, the total UV irradiation time varies depending on the thickness of the coating layer, but is usually 1
It is 0 seconds to 10 minutes, preferably 30 seconds to 7 minutes. Further, in the present invention, when the composition is polymerized by irradiating with the ultraviolet ray as described above, the temperature of the composition is 0-10.
It is preferable to control within the range of ° C. Expensive equipment is required to lower the polymerization reaction temperature below 0 ° C.
Further, at a temperature lower than 0 ° C., the irradiation time becomes long and it is not efficient. On the other hand, if the temperature exceeds 10 ° C., the chain transfer rate increases and it is difficult to efficiently obtain a high molecular weight polymer. Then, as described above, by performing the photopolymerization reaction at a low temperature and in at least three stages, the polymerization reaction does not proceed in a completely random state but in a certain degree of order. Therefore, it is difficult for the obtained polymers to have significant variations in the molecular weight, molecular weight distribution, structure, characteristics, and the like. In particular, runaway reaction can be effectively prevented.

As described above, the acrylic pressure-sensitive adhesive sheet for optical members manufactured by the method of the present invention is irradiated with ultraviolet rays in three or more steps in multiple steps, and the ultraviolet rays are irradiated to cause a polymerization reaction. A very uniform acrylic pressure-sensitive adhesive sheet for optical members can be produced. Moreover, when a low Tg low molecular weight polymer (c) is used as the low molecular weight polymer, it has an excellent effect of relieving internal stress generated inside the acrylic pressure sensitive adhesive sheet, and this acrylic pressure sensitive adhesive sheet is used for a large area liquid crystal device or the like. Even in such a case, 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.

[0043]

In the method for producing an acrylic pressure-sensitive adhesive sheet for optical members of the present invention, (a) an acrylic monomer having a (meth) acrylic acid ester as a main component, and a predetermined amount of (b) a high molecular weight polymer, A predetermined amount of (c) a low Tg low molecular weight polymer, a predetermined amount of (d) a photopolymerization initiator, and a predetermined amount of (e) a crosslinking agent, and a composition containing substantially no solvent. An acrylic pressure-sensitive adhesive sheet for an optical member having excellent optical properties is prepared by reacting the composition prepared by dripping the composition on a support and irradiating the composition with ultraviolet rays changed in three or more stages in multiple stages. It can be manufactured. In particular, the photopolymerization reaction is carried out in three stages, and the photopolymerization reaction is carried out at a low temperature, so that the composition coated on the surface of the support is affected by factors such as oxygen which inhibit the progress of the reaction. Becomes difficult,
A PSA sheet having desired properties can be manufactured.

Further, in the acrylic pressure-sensitive adhesive sheet for optical members of the present invention, the pressure-sensitive adhesive layer contains substantially no solvent,
No solvent removal step is required when producing the pressure-sensitive adhesive, and there is no environmental pollution due to the solvent. Further, the acrylic pressure-sensitive adhesive sheet for optical members of the present invention does not contain a solvent as described above, and the pressure-sensitive adhesive obtained from this composition also does not contain a solvent, and the pressure-sensitive adhesive is It also contains virtually no low-boiling substances. Therefore, the offensive odor such as the residual organic solvent odor peculiar to the conventional pressure-sensitive adhesive is small.

[0045]

EXAMPLES Next, the acrylic pressure-sensitive adhesive sheet for optical members of the present invention and the method for producing the same will be specifically described with reference to Examples, but the present invention is not limited to these.

[0046]

[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 50 ° 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. The syrup had a monomer concentration of 71% by weight and a polymer concentration of 29% by weight. The polymer content in the acrylic syrup A-1 was measured by GPC.
The weight average molecular weight (Mw) measured by was 720,000.

[0048]

[Production Example 2] Preparation of acrylic syrup A-2 Butyl acrylate (hereinafter referred to as BA): 1900 g, A
A: 50 g, 2-hydroxyethyl acrylate (hereinafter 2-H
EA): 50 g, and 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1 (manufactured by Ciba-Geigy Co., Ltd., trade name Irgacure 907): 0.
03 g was placed in a photopolymerization apparatus and intermittently irradiated with an ultraviolet ray having an intensity of 56 W / m ² , to obtain an acrylic syrup A-2. This syrup has a monomer concentration of 85% by weight and a polymer concentration of 15% by weight, and this acrylic syrup A-
The weight average molecular weight (Mw) of the polymer component in 2 was 950,000 as measured by GPC.

[0049]

[Production Example 3] Preparation of 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 set to 6 by a 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. Continuous polymerization initiator
1,1'-azobis (cyclohexane-1-carbonitrile):
After 1.5 g of the solution was put under stirring to carry out a polymerization reaction for 2 hours,
The reaction system was cooled to room temperature with a water bath to obtain low molecular weight polymer L-1.

The resulting 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.

[0053]

[Production Example 4] Preparation of low molecular weight polymer L-2 In Production Example 1, 2-EHA: 980 g, AA: 20 g
And n-dodecyl mercaptan as a molecular weight regulator: 1
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 resulting 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.

[0055]

[Formulation 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.

[0056]

[Formulation Examples 2-7] Adhesive compositions E-2 to 7 were prepared in the same formulation as shown in Table 1 in the same manner as in Formulation Example 1. E-3 was mixed with a silane coupling agent (KBM-403, manufactured by Shin-Etsu Polymer Co., Ltd.). << Evaluation Test of Adhesive Sheet >> Preparation of Test Piece The adhesive sheet was transferred to a three-layer laminated polarizing plate composed of triacetyl cellulose / polyvinyl alcohol / triacetyl cellulose, and cut into 150 mm × 200 mm to obtain a test piece. 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.

[0057]

Example 1 Acrylic pressure-sensitive adhesive composition E-1 was applied onto a peeled polyester film having a thickness of 25 μm. The maximum strength of this is 100 under nitrogen gas atmosphere.
Photopolymerization was performed by irradiating light from a high-pressure mercury lamp adjusted to 0 W / m ² . The polymerization rate at this time is 2% by weight
Met.

Then, light was irradiated from a high-pressure mercury lamp adjusted to have a maximum intensity of 20 W / m ² to carry out second-stage photopolymerization. The polymerization rate after the second-stage polymerization was 92% by weight. Further, light was irradiated from a high pressure mercury lamp adjusted to have a maximum intensity of 2000 W / m ^2, and photopolymerization of the third step was performed. The polymerization rate after this third-stage polymerization is
It was 99.8% by weight. Table 2 shows the evaluation test results of the acrylic pressure-sensitive adhesive sheet for optical members thus obtained.

[0059]

Examples 2 to 4 and Comparative Examples 1 to 5 In the same manner as in Example 1, adhesive sheets for optical members were obtained under the polymerization conditions shown in Table 2. Table 2 also shows the evaluation test results of the obtained pressure-sensitive adhesive sheet for optical members.

[0060]

Examples 5 to 8 and Comparative Examples 6 to 10 As in Example 1,
Under the polymerization conditions shown in Table 3, an adhesive sheet for optical members was obtained.
Table 3 also shows the evaluation test results of the obtained pressure-sensitive adhesive sheet for optical members.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G02B 5/30 G02B 5/30 F term (reference) 2H049 BA02 BB52 BC22 4J004 AA10 AA17 AB01 AB07 CA04 CA06 CC02 FA08 GA01 4J040 DF021 EF181 EF291 EF301 FA141 FA151 FA161 HB14 HC01 JA09 JB08 JB09 KA13 KA16 LA01 LA02 LA10 MA05 MA10 NA17

Claims (8)

[Claims] 1. (a) Acrylic monomer having a (meth) acrylic ester as a main component, and the acrylic monomer 1.
(B) (meth) acrylic acid ester component unit as a main constitutional unit, 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) (meth) ) 10 to 200 parts by weight of a low Tg low molecular weight polymer having an acrylic acid ester component unit as a main constitutional unit, a weight average molecular weight of 20,000 or less, and a glass transition temperature (Tg) of 20 ° C. or less; A composition containing 0.01 to 5 parts by weight of a polymerization initiator, (e) a cross-linking agent, and substantially no solvent is drowned on a support, and the composition is exposed to ultraviolet light in three or more stages. A method for producing an acrylic pressure-sensitive adhesive sheet for optical members, which comprises reacting the composition by irradiating the composition in different stages. 2. The ultraviolet ray is 500 to 5000 (W / m ² )
The irradiation is performed under the condition of 1 or more and less than 500 (W / m ² ), and then the irradiation is performed under the condition of 500 to 10,000 (W / m ² ) after the irradiation of 1) or less. A method for producing an acrylic pressure-sensitive adhesive sheet for optical members. 3. The method for producing an acrylic pressure-sensitive adhesive sheet for an optical member according to claim 1, wherein the glass transition temperature of the high molecular weight polymer (b) is within the range of −85 to 0 ° C. 4. The optical 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 acrylic adhesive sheet for parts. 5. A support and the following composition sprinkled on the support have an adhesive layer obtained by reacting the composition by irradiating the composition with ultraviolet light in three or more stages in multiple stages. Acrylic pressure-sensitive adhesive sheet for optical member characterized by: (a) (meth) acrylic acid ester as a main component, and (b) (meth) acrylic acid ester based on 100 parts by weight of the acrylic monomer. 5 to 200 parts by weight of a high molecular weight polymer having a component unit as a main constitutional unit and a weight average molecular weight of 50,000 or more, and optionally (c) a (meth) acrylic acid ester component unit as a main constitutional unit and having a weight average molecular weight of 10 to 200 parts by weight of a low Tg low molecular weight polymer having a glass transition temperature (Tg) of 20 ° C. or less, (d) a photopolymerization initiator of 0.01 to 5 parts by weight, and (e) Contains a cross-linking agent Composition containing no solvent. 6. The above-mentioned ultraviolet ray is 500 to 5000 (W / m ² ).
The irradiation is performed under the condition of 1 or more and less than 500 (W / m ² ), and then the irradiation is performed under the condition of 500 to 10,000 (W / m ² ) after the irradiation under the condition of 1. Acrylic adhesive sheet for optical members. 7. The acrylic pressure-sensitive adhesive sheet for an optical member according to claim 5, wherein the glass transition temperature of the high molecular weight polymer (b) is within the range of −85 to 0 ° C. 8. The optical 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. Acrylic adhesive sheet for parts.