JP2003049130A - 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 by the method. SOLUTION: This method for producing an 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 and, if necessary, (c) 10-200 pts.wt. of a low-molecular weight polymer composed of a (meth)acrylic acid ester component unit as a main constituent unit and having a high Tg and a low molecular weight of <=20,000 Mw and >=25 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 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 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.

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. A further 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 by photopolymerization.

[0012]

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; (Meth) acrylic acid ester component unit as a main constituent unit, 5 to 200 parts by weight of a high molecular weight polymer having a weight average molecular weight of 50,000 or more, and if necessary, (c) a (meth) acrylic acid ester component unit as a main constituent unit 10 to 200 parts by weight of a high Tg low molecular weight polymer having a unit weight average molecular weight of 20,000 or less and a glass transition temperature (Tg) of 25 ° C. or higher, and (d) a photopolymerization initiator of 0.
A composition containing 01 to 5 parts by weight and (e) a cross-linking agent and containing substantially no solvent is dripped onto a support, and the composition is irradiated with ultraviolet rays in three or more stages in multiple stages. And reacting the composition.

The acrylic adhesive tape of the present invention is
A composition containing a support and the above-mentioned components (a) to (e) sprinkled on the support and containing substantially no solvent is irradiated with ultraviolet rays in three or more stages in multiple stages. It is characterized by having an adhesive layer obtained by reacting the composition. In the present invention, the composition sprinkled on the support is exposed to UV rays.
Irradiation is performed in multiple steps or more, but the intensity of the ultraviolet rays applied at this time is 500 to 5000 (W / m ² ) and then 1 or more and less than 500 (W / m ² ) It is preferable to adjust the ultraviolet irradiation energy so that the irradiation is performed first, and then irradiation is performed under the condition of 500 to 10,000 (W / m ² ) so that the irradiation becomes strong, weak, and strong.

[0014]

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, if necessary, (c) a high Tg low molecular weight polymer, (d) a photopolymerization initiator, and (e) a cross-linking agent. It is manufactured by photopolymerizing under a specific temperature condition on a support using a composition containing an agent and substantially not containing a 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 acid 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-based monomer containing 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 accordingly, 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, and (meth) acrylate.
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 (b) high molecular weight polymer 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 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 5 to 180 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). Used in the present invention
(c) The high Tg low molecular weight polymer is a polymer having a (meth) acrylic acid ester component unit as a main constituent unit and has a weight average molecular weight of 20,000 or less, preferably 1,000.
0 or less, particularly in the range of 10,000 to 2000, and the glass transition temperature (Tg) of this acrylic polymer is 2
It is 5 ° C or higher, preferably in the range of 40 to 180 ° C.

When the weight average molecular weight of this (c) high Tg low molecular weight polymer exceeds 20,000, the effect of improving the adhesive performance in the adhesive tape obtained using the composition of the present invention is not sufficiently exhibited. The above-mentioned (c) high Tg low molecular weight polymer 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 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) high 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) high 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-mentioned (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) high Tg low molecular weight polymer used in the present invention is 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 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.

Further, this (c) high Tg low molecular weight polymer is
It is preferable that a functional group reactive with an epoxy group or an isocyanate group is introduced. Examples of such functional groups include a hydroxyl group, a carboxyl group, an amino group,
Examples include amide group and mercapto group. (C) High Tg
It is preferred to use monomers having such functional groups in making low molecular weight polymers. Usually, the (c) high Tg low molecular weight polymer is used in an amount of 10 to 200 parts by weight, preferably 10 to 180 parts by weight, based on 100 parts by weight of the (a) acrylic monomer. used.

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 among the components formed by polymerizing the component (a), the component (b) and 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 cross-linking agent comprises the above-mentioned component (a), component (b),
It is added in an amount within the range of 0.01 to 5 parts by weight, preferably 0.01 to 3 parts by weight, based on 100 parts by weight of the total of the component (c). 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 includes, 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, polymerization inhibitors, stabilizers, etc. The agent may be blended.

Further, the composition used in the present invention comprises water,
Substantially free of aqueous or organic solvents,
The component (b), the component (c), 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, the above-mentioned (a) acrylic monomer, (b) high molecular weight polymer, (c) high Tg low molecular weight polymer, (d) photopolymerization initiator, (e) cross-linking It can be prepared by mixing the agent and, if desired, other components, and the unreacted monomer remaining when preparing the polymer 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, a predetermined amount of (c) high Tg low molecular weight polymer, (d) photopolymerization initiator, (e) cross-linking agent, and 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), the component (c), the component (d) and the component (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., it is usually 100 to 100000 cps, preferably 500 to 50.
It exhibits a viscosity in the range of 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 0.00
It is 1 to 1.0 mm.

The composition thus coated on the surface of the support is polymerized on this support. In the composition used in the present invention (the composition coated on the surface of the support), (d) a photopolymerization initiator is oriented as a reaction initiator, and the composition is irradiated with a predetermined light beam. This starts 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 ultraviolet rays 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 tape As a result, it is possible to manufacture a uniform tape having no unevenness in characteristics. At this time, the irradiation condition of ultraviolet rays is such that the maximum intensity of light is usually 5 in the first stage light irradiation.
00-5000 (W / m ² ), preferably 500-3
Set to 000 (W / m ² ). If the maximum intensity of the ultraviolet rays to be irradiated in this first stage is less than the lower limit value, the ultraviolet irradiation time may be long and the productivity may not be improved. It is expensive and can lead to high costs. 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
The ultraviolet irradiation conditions are set so as to be 10% by weight, preferably 0.1 to 5% by weight. 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 above range, the adhesive performance of the adhesive tape, particularly the heat resistance, is reduced.

In the present invention, the ultraviolet irradiation in the second step is performed so that the maximum intensity of light is 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 adhesive tape 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 has a maximum light intensity of 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 second to 5 minutes, preferably 30 seconds to 3 minutes. Further, in the present invention, it is preferable that the temperature of the composition is not so high when the composition is irradiated with ultraviolet rays as described above. At this time, the reaction is preferably carried out so that the temperature of the composition becomes 50 ° C. or lower, and particularly the temperature of the composition may be controlled within the range of 0 to 35 ° C., preferably 0 to 30 ° C. That is, in order to lower the polymerization reaction temperature below 0 ° C., expensive equipment is required, and at 0 ° C. or lower, the reaction rate becomes too low, which is inefficient, and the polymerization reaction temperature exceeds the above upper limit temperature. If it exceeds, the chain transfer rate increases and it is difficult to form a high molecular weight polymer.

Since the acrylic pressure-sensitive adhesive tape manufactured by the method of the present invention is irradiated with ultraviolet rays in three or more stages, a very homogeneous acrylic pressure-sensitive adhesive tape can be manufactured. Moreover, high Tg low molecular weight polymer
When (c) is used, the acrylic pressure-sensitive adhesive tape of the present invention exhibits excellent heat resistance and wet heat resistance. In addition, when the high Tg low molecular weight polymer (c) 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.

[0044]

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) high Tg low molecular weight polymer, a predetermined amount of (d) a photopolymerization initiator, and a predetermined amount of (e) a cross-linking agent, a substantially solvent-free composition prepared Then
By dripping this composition on a support and irradiating this composition with ultraviolet rays changed in three or more stages in multiple stages and reacting this composition, excellent adhesive strength is exhibited and high holding power is obtained. In addition, it is possible to manufacture an acrylic pressure-sensitive adhesive tape having excellent adherence to curved surfaces. In particular, by performing the photopolymerization reaction in three stages, the composition coated on the surface of the support is less susceptible to factors such as oxygen that inhibit the progress of the reaction, and an adhesive tape having desired characteristics can be obtained. It can be manufactured.

The acrylic adhesive tape of the present invention is
Since the pressure-sensitive adhesive layer contains substantially no 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.

[0046]

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.

[0047]

[Production Example 1] Preparation of high Tg low molecular weight polymer (C-1) Volume 2 equipped with stirrer, thermometer, nitrogen gas introduction pipe and cooling pipe
Into a 4-liter four-necked flask, 1,200 g of isobutyl methacrylate (hereinafter referred to as i-BMA) and 96 g of n-dodecyl mercaptan as a molecular weight modifier were charged and heated to 70 ° C. while replacing the air in the flask with nitrogen. did.

Next, 3.6 g of cumyl peroxyneodecanoate as a polymerization initiator 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 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 (C-1) was obtained. The weight average molecular weight (Mw) of the obtained high Tg low molecular weight polymer (C-1) was 490.
0 and the glass transition temperature (Tg) was 48 ° C.

[0050]

[Production Example 2] Preparation of acrylic syrup A-1 A 2-liter four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introducing tube and a cooling tube was charged with 2-ethylhexyl acrylate (hereinafter referred to as 2-EHA). ): 919 g, acrylic acid (hereinafter referred to as AA): 80 g, 2-hydroxyethyl acrylate: 1 g, n-dodecyl mercaptan: 0.6 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. The temperature of the reaction system is 115
When the temperature was lowered to ℃, forced cooling was performed to obtain an acrylic syrup A-1. This syrup (acrylic syrup A-1) contains a monomer at a concentration of 67% by weight and a polymer at a concentration of 33% by weight.
The weight average molecular weight (Mw) of the polymer component in -1 measured by GPC was 210,000.

[0052]

[Production Example 3] Preparation of acrylic syrup A-2 Butyl acrylate (hereinafter referred to as BA): 1920 g, A
A: 80 g, 2-methyl-1- [4- (methylthio) phenyl] -2-
Morpholinopropanone-1 (manufactured by Ciba-Geigy Co., Ltd., trade name Irgacure 907): 0.03 g was charged into a photopolymerization apparatus and intermittently irradiated with an ultraviolet ray having an intensity of 56 (W / m ² ) to obtain an acrylic system. Syrup A-2 was obtained. The monomer concentration in this acrylic syrup A-2 was 80% by weight, and the polymer concentration was 20% by weight. Regarding the polymer content contained in this acrylic syrup A-2, G
The (Mw) measured by PC was 800,000.

[0053]

Example 1 As shown in Formulation Example 1 in Table 1, 100 g of acrylic syrup A-1, 20 g of high Tg low molecular weight polymer (C-1), and 2-hydroxy- as a photopolymerization initiator
0.3 g of 2-methyl-1-phenyl-propan-1-one (trade name: Darocur 1173; manufactured by Ciba Geigy)
As a cross-linking agent, N, N, N ', N'-tetraglycidyl-m-xylylenediamine (trade name: Tetrad X; manufactured by Mitsubishi Gas Chemical Co., Inc.) was mixed in an amount of 0.05 g to obtain an acrylic adhesive. Agent composition E-1 was obtained.

Pressure-sensitive adhesive composition E obtained as described above
-1 was applied to a peeled polyester film having a thickness of 25 μm so as to have a thickness of 30 μm. This is room temperature, under nitrogen gas atmosphere, maximum strength 1000W
The light was irradiated with light from a high-pressure mercury lamp adjusted to be / m ² to perform photopolymerization. The polymerization reaction rate after the first-stage polymerization reaction was 4% by weight.

Next, in a nitrogen gas atmosphere, the maximum strength is 4
Photopolymerization was carried out by irradiating light from a high pressure mercury lamp adjusted so as to be 00 W / m ² . The polymerization reaction rate after the second-stage polymerization reaction was 94% by weight. Further, in a nitrogen gas atmosphere, light was irradiated from a high pressure mercury lamp adjusted to have a maximum intensity of 1500 W / m ² to perform photopolymerization.
The polymerization reaction rate after the third-stage polymerization reaction was 99.8% by weight.

Table 2 shows the adhesive performance of the obtained adhesive tape. The adhesive property of the adhesive tape was evaluated as follows. <Adhesive Tape Evaluation Test> Adhesive Strength Test The obtained adhesive tape was transferred to a 25 μm PET film and the adhesive strength was measured according to JIS Z-0273.
As the adherend, SUS304 plate and polypropylene were used. Holding power test The obtained pressure-sensitive adhesive tape was transferred to a PET film of 25 μm, and SUS304 was used as an adherend according to JIS Z-0273, and the attachment area was 20 mm × 20 mm, 23 ° C., 65 ° C.
After sticking under the condition of RH%, the time from standing still at 80 ° C. for 20 minutes to dropping with a load of 1 kg or the deviation after 1 hour was measured. Curved surface sticking test The obtained adhesive tape was transferred to a urethane foam having a thickness of 5 mm to prepare a test tape for a curved surface sticking test. This test tape was cut into 20 mm × 50 mm to obtain a test piece.
50 mm of this test piece polished with No. 280 water-resistant abrasive paper
It was attached to a φSUS304 cylinder. The sample was left to stand at 23 ° C. for 24 hours and further left at 40 ° C. for 24 hours, and the edge or peeling distance of the edge of the test piece was measured.

[0057]

[Example 2] The acrylic syrup A in Example 1
An acrylic pressure-sensitive adhesive composition E-2 was obtained in the same manner except that an acrylic syrup A-2 was used instead of -1 (see Formulation Example 2 in Table 1). Next, using the acrylic pressure-sensitive adhesive composition E-2, a pressure-sensitive adhesive tape was obtained in the same manner except that the photopolymerization in the first, second and third steps was performed as shown below.

The maximum intensity of ultraviolet rays in the first stage is 80
The polymerization reaction rate is 0 W / m ² , the polymerization reaction rate is 1% by weight, the maximum intensity of ultraviolet rays in the second step is 200 W / m ² , the polymerization reaction rate is 91% by weight, and the maximum ultraviolet rays in the third step is The strength was 2000 W / m ² and the polymerization reaction rate was 99.5% by weight. Table 2 shows the adhesive performance of the obtained adhesive tape.

[0059]

Example 3 100 g of acrylic syrup A-1 and B
20 g of A, 30 g of high Tg low molecular weight polymer (C-1), 2-hydroxy-2-methyl-1-phenyl as a photopolymerization initiator
0.3 g of -propan-1-one (trade name: Darocur 1173; manufactured by Ciba Geigy Ltd.), an isocyanate compound composed of toluene diisocyanate and trimethylolpropane as a cross-linking agent (trade name: Coronate L; Nippon Polyurethane Co., Ltd.) (Manufactured by Mfg. Co., Ltd.) was mixed to obtain an acrylic pressure-sensitive adhesive composition E-3 (see Formulation Example 3 in Table 1).

Then, this acrylic pressure-sensitive adhesive composition E-
A pressure-sensitive adhesive tape was obtained in the same manner as in Example 3, except that the first, second, and third photopolymerizations were performed as described below. However, a black light was used for the second stage ultraviolet irradiation. The maximum intensity of ultraviolet light in the first stage is 1000 W / m ²
The polymerization reaction rate was 3% by weight, the maximum intensity of ultraviolet light (using black light) in the second step was 40 W / m ² , and the polymerization reaction rate was 93% by weight. The maximum strength is 3000 W / m ² and the polymerization reaction rate is 9
It was 9.9% by weight.

Table 2 shows the adhesive performance of the obtained adhesive tape.

[0062]

[Example 4] In Example 1, the maximum intensity of the ultraviolet light in the first step was 3000 W / m ² , the polymerization reaction rate was 9% by weight, and the maximum intensity was obtained by using a black light for the ultraviolet irradiation in the second step. Was 40 W / m ² to give a polymerization reaction rate of 90%, and the third stage maximum intensity of ultraviolet rays was 2000 W / m ² to give a polymerization reaction rate of 99.5% by weight. did.

Table 2 shows the adhesive performance of the obtained adhesive tape.

[0064]

Example 5 An acrylic pressure-sensitive adhesive composition E-4 was obtained in the same manner as in Example 1 except that the high Tg low molecular weight polymer (C-1) was not used (compounding example in Table 1). 4). Then, using the acrylic pressure-sensitive adhesive composition E-4, a pressure-sensitive adhesive tape was prepared in the same manner as in Example 1. Table 2 shows the adhesive performance of the obtained adhesive tape.

[0065]

Comparative Example 1 In Example 1, the ultraviolet irradiation of the second stage was directly performed without performing the ultraviolet irradiation of the first stage (maximum intensity of 40%).
0 W / m ² , polymerization reaction rate 94% by weight), and then UV irradiation was performed in the same manner as in Example 1 as in the third step. The polymerization reaction rate by ultraviolet irradiation in the third step was 99.8% by weight.

Table 2 shows the adhesive performance of the obtained adhesive tape.

[0067]

[Comparative Example 2] In Example 1, the polymerization reaction rate by the first stage ultraviolet irradiation was set to 20% by weight, the polymerization reaction rate by the second stage ultraviolet irradiation was set at 93% by weight, and the third stage ultraviolet irradiation was performed. An adhesive tape was prepared in the same manner except that the polymerization reaction rate by irradiation was set to 99.4% by weight.

Table 2 shows the adhesive performance of the obtained adhesive tape.

[0069]

[Comparative Example 3] In Example 1, the polymerization reaction rate by UV irradiation in the first step was 4% by weight, the polymerization reaction rate by UV irradiation in the second step was 80% by weight, and the UV conversion in the third step was performed. An adhesive tape was prepared in the same manner except that the polymerization reaction rate by irradiation was set to 99.2% by weight.

Table 2 shows the adhesive performance of the obtained adhesive tape.

[0071]

[Comparative Example 4] In Example 1, the polymerization reaction rate by the first stage ultraviolet irradiation was set to 3% by weight, and the polymerization reaction rate by the second stage ultraviolet irradiation was set to 99% by weight. An adhesive tape was prepared in the same manner except that the polymerization reaction rate by irradiation was set to 99.4% by weight.

Table 2 shows the adhesive performance of the obtained adhesive tape.

[0073]

[Comparative Example 5] In Example 1, the polymerization reaction rate by ultraviolet irradiation of the first step was set to 3% by weight, and the polymerization reaction rate of ultraviolet irradiation in the second step was adjusted to 93% by weight. An adhesive tape was prepared in the same manner except that the polymerization reaction rate by irradiation was set to 96.5% by weight.

Table 2 shows the adhesive performance of the obtained adhesive tape.

[0075]

[Table 1]

[0076]

[Table 2]

[0077]

[Example 6] In Example 1, the acrylic pressure-sensitive adhesive composition E-1 was applied on a polyester film having a thickness of 25 µm to a thickness of 30 µm. While maintaining the temperature of this composition at 5 ° C., the maximum intensity of UV irradiation in the first step was 1000 W / m ² under a nitrogen gas atmosphere, and the maximum UV irradiation in the second step and the third step was maximum. The strength is the same as in Example 1, and the temperature of the composition is 5 ° C.
The adhesive tape was manufactured while maintaining The polymerization reaction rate of the obtained adhesive tape was 99.5% by weight. Table 3 shows the adhesive performance of the obtained adhesive tape.

[0078]

[Table 3]

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09J 4/00 C09J 4/00 4J040 163/00 163/00 175/04 175/04 F term (reference) 4J004 AA01 AA10 AB01 AB05 AB07 CA02 CA04 CA06 CA08 CB01 CB02 CC02 EA06 FA05 FA10 GA01 4J011 PA69 PC02 PC08 4J026 AA44 AC18 BA27 BB07 4J034 BA03 DA05 DP18 HA01 HA02 HA07 HC03 HC12 HC71 HC22 HC08 HC22 HC64 HC67 HC71 HC71 HC71 HC71 HC22 JA15 4J040 EC022 EC122 EF032 EF282 FA011 FA012 FA081 FA082 FA131 FA132 FA201 FA202 FA221 FA222 GA05 GA07 GA14 GA22 GA24 HB13 HB18 HD21 JA09 JA12 JB02 JB08 KA13 KA16 LA06 LA07 LA08 MA05 MA10 MB03 NA17 NA19 PA23 PA30 PA32 PA32

Claims (9)

[Claims] 1. (a) Acrylic monomer having a (meth) acrylic ester as a main component, and the acrylic monomer 1.
5 to 200 parts by weight of a high molecular weight polymer having a (meth) acrylic acid ester component unit as a main constitutional unit and a weight average molecular weight of 50,000 or more with respect to 00 parts by weight, and if necessary, (c) ( 10 to 200 parts by weight of a high Tg low molecular weight polymer having a (meth) 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 25 ° C. or more, (d) A composition containing 0.01 to 5 parts by weight of a photopolymerization 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 tape, 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. Acrylic adhesive tape manufacturing method. 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. Of adhesive tape. 5. 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. 6. A support, and a pressure-sensitive adhesive layer obtained by reacting the composition by irradiating the composition described below, which has been drowned on the support, with ultraviolet light in three or more stages in multiple stages. 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 (meth) acrylic acid ester component unit as a main constitutional unit, and a weight average molecular weight of 20,000 or less. 10 to 200 parts by weight of a high Tg low molecular weight polymer having a glass transition temperature (Tg) of 25 ° C. or higher, (d) a photopolymerization initiator of 0.01 to 5 parts by weight, and (e) a crosslinking agent. Contains, substantially contains solvent There is no composition. 7. 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 under the condition of 1. Acrylic adhesive tape. 8. The acrylic pressure-sensitive adhesive tape according to claim 6, wherein the glass transition temperature of the high molecular weight polymer (b) is in the range of −85 to 0 ° C. 9. The acrylic according to claim 6, wherein the crosslinking agent (e) is at least one kind of compound selected from the group consisting of polyfunctional epoxy compounds and polyfunctional isocyanate compounds. System adhesive tape.