JP2000144094A - Light postcurable adhesive composition and bonding of parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light postcurable adhesive compsn. which shows a suffi cient pressure-sensitive adhesivity at an initial stage, ensures a sufficient avail able application time after light irradiation, and furnishes an excellent adhesive strength after curing. SOLUTION: This is a light postcurable adhesive compsn. contg. a cationically polymerizable compd. (A) having at least one cationically polymerizable group in one molecule, a photopolymerization initiator (B) which can polymerize or cure the cationically polymerizable compd. (A) with light irradiation, and at least one type of polymer (C). When the photopolymerization initiator (B) is activated by irradiating this adhesive compsn. with light, the conversion rate of the cationically polymerizable compd. (A) exceeds 10% in the time range of 5 min to 5 hr at 25 deg.C. Furthermore, the conversion rate is 50% or more when aged at 25 deg.C for 7 days.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photo-curing type pressure-sensitive adhesive composition and a method for joining members, and more particularly, to a photo-curing type pressure-sensitive adhesive composition which has an adhesive force in an initial state, and has an adhesive force for a while after light irradiation. The present invention relates to a photo-curable pressure-sensitive adhesive composition that can be maintained and can be easily bonded, and exhibits a strong adhesive strength after a predetermined time after light irradiation, and a method for bonding members using the pressure-sensitive adhesive composition.

[0002]

2. Description of the Related Art Hitherto, a so-called pressure-sensitive adhesive has been proposed which has both easy workability of a pressure-sensitive adhesive, safety by eliminating volatile components, and adhesive strength and film strength comparable to an adhesive.

For example, Japanese Patent Application Laid-Open No. 2-272076 discloses a pressure-sensitive adhesive tape using a pressure-sensitive thermosetting adhesive made of a photopolymerizable composition containing an acrylate monomer and an epoxy resin. . Here, of the photopolymerizable composition, only the acrylate monomer is polymerized to form an adhesive tape. In this state, the adherends are bonded to each other via an adhesive tape, and thereafter, the epoxy resin is cured by heating, whereby sufficient adhesive strength is obtained.

However, in the method described in Japanese Patent Application Laid-Open No. 2-272076, an epoxy resin is cured by using heat to develop an adhesive force. Therefore, the method cannot be applied to an adherend made of a material having insufficient heat resistance, such as plastic, and the material of the adherend to be bonded is limited.

On the other hand, Japanese Patent Publication No. 5-506465 discloses a pressure-sensitive composition containing a radical photopolymerizable component such as an acrylate monomer, a cationic photopolymerizable component such as an epoxy compound, and an organometallic complex polymerization initiator. An adhesive is disclosed. This pressure-sensitive adhesive has been proposed in order to increase the adhesive force.In the production of the pressure-sensitive adhesive, light is irradiated to irradiate both the photoradical polymerizable component and the photocationic polymerizable component. Polymerized. That is, both radical polymerization and cationic polymerization are caused to constitute the pressure-sensitive adhesive.

Accordingly, the polymerization reaction has already been completed when the pressure-sensitive adhesive is formed into a sheet or the like, for example, and is configured to have sufficient sheet strength in advance. Therefore, when the adherend is joined, the adhesive strength is excellent, but even if energy such as heat or light is applied, the adhesive strength cannot be further improved.

[0007] On the other hand, epoxy-based adhesives have a cured adhesive product having excellent creep resistance, light resistance, water resistance, heat resistance, chemical resistance, etc., excellent adhesive strength, and Since it can bond a wide range of materials such as metal, plastic or glass, it is widely used for bonding various members ("New Epoxy Resin", edited by Hiroshi Kakiuchi, Shokodo, 1985).

However, the epoxy resin adhesive is
Generally, it is used in a liquid form. Therefore, uneven application at the time of applying the epoxy resin-based adhesive occurs,
The appearance of the end face of the joint may be impaired due to the exudation of the adhesive at the time of excessive application. In addition, since it is in a liquid state, it cannot be applied again to the surface once applied. Furthermore, since it is usually configured as a two-part adhesive, the mixing ratio between the main agent and the curing agent is limited, and poor adhesion is likely to occur due to mixing errors.

In order to solve the above problems,
A sheet or film formed from an epoxy resin-based adhesive has been proposed (JP-A-60-173076).
No.). However, such a sheet-like epoxy adhesive has a high elastic modulus in a normal state and a low initial adhesive strength, and thus does not have a temporary fixing property. Therefore, there is a problem that workability at the time of joining is not sufficient. In addition, since the sheet-like epoxy adhesive has insufficient adhesion to the adherend,
When bonding the adherends, severe curing conditions such as a high-temperature press or a high-pressure press are required, and the method cannot be applied to an adherend having no resistance to such curing conditions.

The present inventors have previously proposed a photopolymerizable composition utilizing two different polymerization modes (Japanese Patent Application Laid-Open No.
-279103). That is, a photopolymerizable composition including a radically polymerizable monomer such as an acrylic monomer, a radical polymerization catalyst, an epoxy group-containing compound, and a cationic polymerization catalyst for curing the epoxy group-containing compound has been proposed. Here, light is irradiated in advance to activate the radical polymerization catalyst, and the radical polymerizable monomer is polymerized,
After forming the tackifying polymer, the composition is formed into a sheet. In use, the sheet is irradiated with light that activates the cationic polymerization catalyst to cure the epoxy resin, thereby providing sufficient adhesive strength.

However, there has been a problem that curing the epoxy resin requires a long time curing after irradiation with light. In addition, the inventors of the present application have previously proposed a curable adhesive which can bond adherends under curing conditions that are not easily restricted by the adherend (Japanese Patent Laid-Open No. 10-120988). Here, a curable adhesive sheet containing an acrylic polymer, an epoxy resin, and a cationic photopolymerization initiator is disclosed. In this curable adhesive sheet, the cationic photopolymerization initiator is activated by light irradiation, and the epoxy resin is cured. Therefore, before applying the curable adhesive sheet to the adherend, or simply by irradiating light after the adherence, the adherends can be firmly joined to each other, and the heat resistance of the adherend is not a problem. No.

However, when the curable adhesive sheet is irradiated with light, the curing reaction proceeds at the same time, and after a while, the elastic modulus of the curable adhesive sheet increases. Was. That is, there is a problem in that the time from irradiation of light to the time when bonding becomes possible, that is, the pot life is short. Therefore, the present inventors have studied adding vinyl ether to the curable adhesive composition to thereby extend the pot life (EP).
0819746A2). However, when the pot life is extended by adding vinyl ether, the adhesive strength after curing may still be insufficient.

On the other hand, Japanese Patent Application Laid-Open No. 63-248825 discloses a fixing agent containing a poly (alkylene oxide) residue in order to suppress the surface layer hardening phenomenon called skin sticking which occurs immediately after exposure to ultraviolet light. Hardening type U using
V-curable epoxy resin compositions are disclosed. However, since it is trying to satisfy the property for suppressing the skin sticking simultaneously with the improvement of the adhesive force, it is difficult to design these properties independently.

JP-A-3-172378 discloses a photosensitive curable epoxy adhesive composition using an epoxide curing retarder selected from the group consisting of organic materials substituted with nitrile or vinyl ether. I have. Here, by using an organic material substituted with nitrile or vinyl ether, the pot life can be extended to nearly 40 minutes, but the adhesive strength is not specifically mentioned.

[0015]

SUMMARY OF THE INVENTION In view of the above-mentioned state of the art, an object of the present invention is to have a sufficient initial adhesive force and cohesive force at room temperature, that is, exhibit excellent pressure-sensitive adhesiveness, Is a photo-curable pressure-sensitive adhesive composition which can ensure a sufficient pot life after light irradiation and has excellent adhesive strength after curing, and a method for joining members using the pressure-sensitive adhesive composition Is to provide.

[0016]

Means for Solving the Problems The invention according to claim 1 is characterized in that (A) a cationically polymerizable compound having at least one cationically polymerizable group in one molecule and (B) light irradiation. A photo-curable pressure-sensitive adhesive composition comprising: a polymerization initiator for initiating polymerization of the cationically polymerizable compound (A); and (C) at least one polymer, and irradiating the pressure-sensitive adhesive composition with light. After activating the polymerization initiator (B), the conversion of the cationically polymerizable compound (A) exceeds 10% at 25 ° C. for 5 minutes to 5 hours. The compound (A) has a conversion rate of 50% or more after curing for a day.

The invention according to claim 2 is characterized in that (A)
Having at least one cationically polymerizable group
The polymerizable compound and (B) click when irradiated with light.
Polymerization initiator for initiating polymerization of on-polymerizable compound (A)
Post-curing containing (C) and at least one polymer
A pressure-sensitive adhesive composition, wherein the frequency of the pressure-sensitive adhesive composition is 0.1.
Dynamic shear storage at 1 Hz and temperature range of 0-50 ° C
Elastic modulus is 10^Three-10 ⁶Pa range, for light irradiation
After activating the polymerization initiator (B), it is 5 minutes at 25 ° C.
Dynamic shear at 25 ° C. for a time in the range of
The shear storage modulus is 10 times the dynamic shear storage modulus before light irradiation
Over 7 days after further curing at 25 ° C for 7 days
Dynamic shear storage modulus at 0.1 Hz and 25 ° C. is 1
0⁶-10⁸It is characterized by being in the range of Pa.

According to a third aspect of the present invention, there is provided the photocurable pressure-sensitive adhesive composition according to the first or second aspect, wherein the cationically polymerizable compound (A) has an epoxy group as the cationically polymerizable group. And that the polymer (C) contains at least one (meth)
It is characterized by using a polymer having a compound having an acryloyl group and at least one hydroxyl group and a compound having an unsaturated bond copolymerizable with the compound (C2) (C2).

According to a fourth aspect of the invention, there is provided a method for joining members, wherein at least one of the members to be joined is attached to at least one of the members to be joined.
Before or after application of the photo-curable pressure-sensitive adhesive composition according to any one of the above, light of 300 nm or more and less than 800 nm is irradiated so that the light intensity is 5 mW / cm ² or more,
It is characterized in that members are joined after light irradiation. Hereinafter, details of the present invention will be described.

(Cationically polymerizable compound (A)) The cationically polymerizable compound (A) used in the present invention is not particularly limited as long as it is a compound having at least one cationically polymerizable group in one molecule. For example, a cationically polymerizable compound having a cationically polymerizable group such as a vinyloxy group, a styryl group, an epoxy group, and an oxetanyl group can be used. Preferably, a compound having an epoxy group as a cationically polymerizable group is suitably used because of its excellent adhesiveness and durability.

More specifically, as a compound containing a vinyloxy group, for example, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, tert-amyl vinyl ether, cyclohexyl vinyl ether,
2-ethylhexyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, 2-chloroethyl vinyl ether, ethylene glycol butyl vinyl ether, triethylene glycol methyl vinyl ether,
(4-vinyloxy) butyl benzoate, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, butane-
1,4-diol-divinyl ether, hexane-1,
6-diol-divinyl ether, cyclohexane-
1,4-dimethanol-divinyl ether, di (4-vinyloxy) butyl isophthalate, di (4-vinyloxy) butyl glutarate, di (4-vinyloxy) butyl succinate trimethylolpropane trivinyl ether, 2-hydroxyethyl vinyl ether , 4-hydroxybutyl vinyl ether, 6-hydroxyhexyl vinyl ether, cyclohexane-1,4-dimethanol-monovinyl ether, diethylene glycol monovinyl ether 3-aminopropyl vinyl ether, 2- (N, N-diethylamino) ethyl vinyl ether, urethane vinyl ether, polyester Examples thereof include vinyl ether, but are not particularly limited.

As the compound containing a styryl group, for example,
Styrene, p-methylstyrene, α-methylstyrene,
Examples thereof include p-methoxystyrene, p-tert-butoxystyrene, p-chloromethylstyrene, p-acetoxystyrene, and divinylbenzene, but are not particularly limited.

Examples of the compound having an epoxy group include bisphenol A epoxy resin, hydrogenated bisphenol A epoxy resin, bisphenol F epoxy resin, novolak type epoxy resin, aliphatic cyclic epoxy resin, and brominated epoxy resin. Resin, rubber modified epoxy resin, urethane modified epoxy resin, glycidyl ester compound, epoxidized polybutadiene, epoxidized SBS
(SBS indicates a styrene-butadiene-styrene copolymer), but is not particularly limited. The epoxy compound exhibits high adhesiveness and durability after curing.

Further, as for the cationically polymerizable compound (A) having at least one cationically polymerizable group in one molecule, one kind may be used alone, or two or more kinds may be used in combination. Further, a compound having a plurality of different cationically polymerizable groups in one molecule may be used.

(Polymerization Initiator (B)) The polymerization initiator (B) is prepared by subjecting the cationically polymerizable compound (A) to irradiation with light.
The compound is not particularly limited as long as it is a compound that polymerizes or cures, and a known photocationic polymerization catalyst or the like can be used.

The above-mentioned cationic photopolymerization catalyst is selected from, for example, iron-allene complex compounds, aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, pyridinium salts, aluminum complexes / silyl ethers, and is particularly limited. It is not something to be done. In addition, one kind of photocationic polymerization catalyst may be used as the photocationic polymerization catalyst, or a plurality of kinds may be used in combination.

Specific examples of the above cationic photopolymerization catalyst include IRGACURE 261 (manufactured by Ciba-Geigy),
Optomer SP-150 (made by Asahi Denka Kogyo), Optomer SP-151 (made by Asahi Denka Kogyo), Optmer SP-
170 (manufactured by Asahi Denka Kogyo), Optmer SP-171
(Manufactured by Asahi Denka Kogyo), UVE-1014 (manufactured by General Electronics), CD-1012 (manufactured by Sartomer), Sun Aid SI-60L (manufactured by Sanshin Chemical Industry),
Sun-Aid SI-80L (manufactured by Sanshin Chemical Industry), San-Aid SI-100L (manufactured by Sanshin Chemical Industry), CI-20
64 (manufactured by Nippon Soda), CI-2639 (manufactured by Nippon Soda), CI-2624 (manufactured by Nippon Soda), CI-248
1 (Nippon Soda Co., Ltd.), RHODORSIL Photoiniti
ator 2074 (Rhone Poulin), UVI-6
990 (manufactured by Union Carbide), BBI-103
(Manufactured by Midori Kagaku), MPI-103 (manufactured by Midori Kagaku), TPS-103 (manufactured by Midori Kagaku), MDS-1
03 (manufactured by Midori Kagaku), DTS-103 (manufactured by Midori Kagaku), DTS-103 (manufactured by Midori Kagaku), NAT-
Commercially available products such as 103 (manufactured by Midori Kagaku) and NDS-103 (manufactured by Midori Kagaku) can be used.

(Polymer (C)) As the polymer (C),
A cationically polymerizable compound (A), a polymerization initiator (B),
There is no particular limitation as long as the composition comprising the compound (C) can exhibit adhesiveness. Further, as for the polymer (C), a plurality of kinds of polymers may be appropriately combined and used.

As the polymer (C), (meth) acrylic polymers, polyesters, polyurethanes, silicones, polyethers, polycarbonates, polyvinyl ethers, polyvinyl chlorides, polyvinyl acetates, polyisobutylenes, polyolefins and the like can be used. And copolymers based on these can also be used.

Regarding the polymer structure of the polymer (C), for example, a random copolymer structure, a block copolymer structure, an alternating copolymer structure, a stereoregular copolymer structure, a multi-branched copolymer structure, and a star Examples include a type copolymer structure, a dendritic copolymer structure, a ladder copolymer structure, a cyclic copolymer structure, and a helical copolymer structure, but are not particularly limited.

The molecular weight of the polymer (C) is preferably large, and preferably has a weight average molecular weight of about 200,000 to 5,000,000. When the weight average molecular weight is 200,000 or less, the cohesive force of the photo-curable pressure-sensitive adhesive composition is insufficient, stringing may occur at the time of application, and peeling may occur. In some cases, application and sheet molding may be difficult.

As the polymer (C), preferably,
A compound (C1) having at least one (meth) acryloyl group and at least one hydroxyl group in one molecule;
A polymer containing the compound (C1) and the compound (C2) having a copolymerizable unsaturated bond is used, and thereby it is possible to sufficiently increase the curing speed after a lapse of the usable time, which is desirable.

The compound (C1) is not particularly limited as long as it has at least one (meth) acryloyl group and at least one hydroxyl group in one molecule, and examples thereof include 2-hydroxyethyl (meth) acrylate and 3-hydroxyethyl (meth) acrylate.
Hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 5-hydroxypentyl (meth) acrylate, 6-hydroxyhexyl (meth) Acrylate, 3-hydroxy-3-methylbutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, pentaerythritol tri (meth) acrylate, 2-[(meth) acryloyloxy] ethyl 2-hydroxyethyl phthalate Acid, 2-
[(Meth) acryloyloxy] ethyl 2-hydroxypropyl phthalic acid,

[0034]

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[0035]

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[0036]

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[0037]

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[0039]

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[0041]

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As the compound (C1), only one type may be used, or two or more types may be used in combination.
Further, as for the compound (C2), the compound (C1)
There is no particular limitation as long as it has an unsaturated bond copolymerizable with

Examples of the compound (C2) include styrene derivatives, vinyl ester derivatives, N-vinyl derivatives, (meth) acrylate derivatives, (meth) acrylonitrile derivatives, (meth) acrylic acid, maleic anhydride, and maleimide acid derivatives. Can be mentioned. Compound (C2)
May be used alone or in combination of two or more.

Examples of the styrene derivative include styrene, indene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butoxystyrene, p-chloromethylstyrene, p-acetoxystyrene, divinylbenzene And the like.

Examples of the above vinyl ester derivatives include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl cinnamate and the like. Examples of the N-vinyl derivative include N-vinylpyrrolidone, N-acryloylmorpholine, N-vinylcaprolactone, N-vinylpiperidine and the like.

Examples of (meth) acrylate derivatives include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth) acrylate, and cyclohexyl (meth) acrylate. ) Acrylate, 2
-Ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isomyristyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) Acrylate, 2-butoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, hexanediol di (meth) acrylate, ethylene glycol di (meth)
Acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate,
Trimethylolpropane tri (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate

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Can be used. In the present invention, the compounding ratio of the compound (C1) and the compound (C2) is preferably in the range of 1 to 10,000 polymerization of the compound (C2) with respect to 100 parts by weight of the compound (C1). When the compounding ratio of the compound (C2) is less than 1 part by weight, the curing speed after light irradiation is too fast, and it may be difficult to secure the pot life. If it exceeds 10,000 parts by weight, In some cases, the curing speed is too slow, and it is difficult to achieve a curing speed that can withstand practical use.

(Blending Ratio) In the present invention, the cationically polymerizable compound (A), the polymerization initiator (B) and the polymer (C)
For the cationic polymerizable compound (A) 1
The polymerization initiator (B) is 0.001 to 1 part by weight based on 00 parts by weight.
000 parts by weight, 1 to 10 for polymer (C)
It is preferably in the range of 000 parts by weight.

When the amount of the polymerization initiator (B) is less than 0.001 part by weight, the concentration of active species generated by light irradiation becomes low, so that it may be difficult to obtain a sufficient curing rate, and the amount may be 1000 parts by weight. If the amount exceeds the above range, the concentration of active species generated by light irradiation becomes too high, and it may be difficult to control the polymerization or curing rate.

When the amount of the polymer (C) is less than 1 part by weight,
In some cases, the polymer (C) cannot be expected to exhibit tackiness and initial cohesive strength. When the amount exceeds 10,000 parts by weight, the proportion of the cationically polymerizable compound (A) decreases, and Even if cured, it may be difficult to increase the adhesive strength after light irradiation.

(Conversion rate) In the photo-curing type pressure-sensitive adhesive composition according to the first aspect of the present invention, the pressure-sensitive adhesive composition is irradiated with light to activate the polymerization initiator (B), and then to 25 ° C. 5 to 5 minutes
Cationically polymerizable compound (A) in the time range of time
Of the cationically polymerizable compound (A) after curing at 25 ° C. for further 7 days has a conversion of more than 10%.
%.

If the conversion of the cationically polymerizable compound (A) exceeds 10% by 5 minutes at 25 ° C. after activating the polymerization initiator (B) by irradiating with light, immediately after irradiating with light, Since the adhesive strength starts to disappear, sufficient pot life cannot be secured.

On the other hand, if the conversion of the cationically polymerizable compound (A) does not exceed 10% even after 5 hours at 25 ° C. after irradiating light to activate the polymerization initiator (B), Although the working time can be long enough, it is difficult to complete the curing quickly.

Further, after light irradiation, the composition is cured,
If the conversion of the cationically polymerizable compound (A) after curing for a day does not exceed 50%, curing will be incomplete and sufficient adhesive strength cannot be expected.

(Dynamic Shear Storage Elastic Modulus in the Invention of Claim 2) The photo-curable pressure-sensitive adhesive composition according to the invention of claim 2 has a frequency of 0.1 Hz and a temperature range of 0 to 50 ° C. Shear modulus of elasticity is 10 ³ to 10 ⁶ Pa
After activating the polymerization initiator (B) by light irradiation, at 25 ° C. for 5 minutes to 5 hours,
The dynamic storage elastic modulus at 25 ° C. exceeds 10 times the dynamic shear storage elastic modulus before light irradiation, and after curing at 25 ° C. for 7 days, the dynamic storage elasticity at 25 ° C. at a frequency of 0.1 Hz is obtained. The rate is in the range of 10 ⁶ to 10 ⁸ Pa.

When the dynamic shear storage modulus is 0.1
When the temperature is less than 10 ³ Pa in Hz and a temperature range of 0 to 50 ° C., the cohesive strength becomes poor, and it becomes difficult to secure a sufficient initial adhesive strength. Conversely, if it exceeds 10 ⁶ Pa, the elastic modulus becomes too high, and it is difficult to secure the initial adhesive strength.

If the dynamic shear storage modulus at 25 ° C. exceeds 10 times that before light irradiation by 5 minutes at 25 ° C. after activating the polymerization initiator (B) by irradiating light, Since the initial adhesive strength starts to disappear immediately after the light irradiation, it is difficult to secure a sufficient pot life.

Further, even after 5 hours at 25 ° C. after activating the polymerization initiator (B) by irradiating light, the dynamic shear storage elastic modulus at 25 ° C. is not changed. If it does not exceed 10 times, the pot life can be made sufficiently long, but it is no longer possible to complete the curing promptly.

Further, after curing at 25 ° C. for 7 days, 25
When the dynamic shear storage modulus at ℃ does not exceed 10 ⁶ Pa is insufficient cohesive strength by it becomes impossible to expect sufficient adhesion, when it exceeds 10 ⁸ Pa, the adhesive force becomes too hard and decrease I do.

The photo-curable pressure-sensitive adhesive composition and the cured product of the present invention have viscoelastic properties, and the mechanical properties of such a substance generally depend on the rate of deformation and temperature applied. It changes ("Lecture / Rheology" edited by The Rheological Society of Japan, Polymer Publishing Association, first edition in 1992). A time-temperature conversion rule is empirically established based on accumulated knowledge so far, and is given as a WLF equation. From such an empirical rule, the measurement value of the dynamic shear storage modulus under conditions different from the measurement conditions in the invention according to claim 2 is obtained by using the above time-temperature conversion rule. Can be converted to a dynamic shear storage modulus. Accordingly, as long as such a converted value satisfies the range described in claim 2, the measured value of the dynamic shear storage modulus measured under the different conditions is included in the range described in claim 2. .

(Production method of photo-curable pressure-sensitive adhesive composition) The production of the photo-curable pressure-sensitive adhesive composition according to the present invention is not particularly limited, and the cationically polymerizable compound (A) and the polymerization initiator (B) ) And the polymer (C) are melt-mixed, or a method obtained by dissolving them in a solvent can be used. That is, it is appropriately selected according to the test state of the compound or composition to be used.

When the photo-curable pressure-sensitive adhesive composition is provided in the form of a pressure-sensitive adhesive sheet, the composition is coated by a known coating method such as hot melt coating or cast coating to form a sheet. I just need.

Preferably, the cationically polymerizable compound (A), the polymerization initiator (B) and one or more of
A photocurable composition containing a compound (D) having an unsaturated double bond in the molecule and a compound (E) that polymerizes the compound (D) by light irradiation to form a polymer (C) is obtained. The photocurable composition may be irradiated with light to activate the compound (E) and polymerize the compound (D), thereby generating the polymer (C). That is, the polymer (C) is produced by polymerization of the compound (D), and the photo-curing type according to the present invention containing the cationic polymerizable compound (A), the polymerization initiator (B) and the polymer (C). An adhesive composition may be formed.

The light source for exposing the compound (E) to light is suitably selected from low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, metal halide lamps, and fluorescent lamps. A light source can be used. In order to expose only the compound (E) and leave the polymerization initiator (B) unexposed, it is desirable to use light obtained by cutting light in the photosensitive wavelength region of the polymerization initiator (B) with a filter or the like.

As the compound (D), for example, a compound having an unsaturated bond exhibiting radical polymerizability can be used. Examples of such a compound include a styrene derivative, a compound having a vinyl ester group, and an acryloyl group. And a compound having a methacryloyl group.

Further, a compound having simultaneously two or more kinds of unsaturated bonds exhibiting radical polymerizability may be used as the compound (D). Examples of the styrene derivative include styrene, indene, P-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butoxystyrene, p-chloromethylstyrene, p-acetoxystyrene, divinylbenzene, and the like. be able to. Examples of the compound having a vinyl ester group include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, and vinyl cinnamate.

Compounds having a (meth) acryloyl group (hereinafter, acryloyl and methacryloyl are collectively referred to as (meth) acryl). As acrylate and (meth) acrylate (collectively referred to as (meth) acrylate), for example, acrylic acid and at least one
A compound obtained by esterifying a compound having one hydroxyl group in a molecule, a compound obtained by esterifying methacrylic acid and a compound having at least one hydroxyl group in one molecule, a plurality of acrylic acid and methacrylic acid in one molecule And a compound obtained by esterifying a compound having a hydroxyl group.

Also, as for the compound (D), it is preferable to use the compound (C1) and the compound (C2) in combination, since the curing rate can be sufficiently increased.

The compound (E) is not particularly limited as long as it does not exhibit a sensitizing effect on the polymerization initiator (B), and a photo-radical polymerization initiator can be suitably used. Examples of such a photoradical polymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone, α-hydroxy-α, α′-dimethylacetophenone, methoxyacetophenone, Acetophenone derivative compounds such as 2-dimethoxy-2-phenylacetophenone; benzoin ether compounds such as benzoin ethyl ether and benzoin propyl ether; ketal derivative compounds such as benzyl dimethyl ketal; halogenated ketones; acyl phosphine oxides; , 2-
Methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-
N, N-dimethylamino-1- (4-morpholinophenyl) -1-butanone; 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; bis- (2
6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide; bis (η5-cyclopentadienyl) -bis (pentafluorophenyl) -titanium, bis (η5-cyclopentadienyl) -bis [2 , 6-Difluoro-3- (1H-pyrid-1-yl)
Phenyl] titanium and the like are not particularly limited. Further, a plurality of types of radical polymerization initiators may be selected and used, or a commercially available one containing the above compound may be used.

(Other Addable Components) In the photo-curable pressure-sensitive adhesive composition according to the present invention, in addition to the above-mentioned essential components, known tackifying resins, extenders, and the like, as long as the object of the present invention is not impaired. A sensitizer and the like may be appropriately blended.

For example, as the tackifier resin, rosin resin, modified rosin resin, terpene resin, terpene phenol resin, aromatic modified terpene resin, C5 or C9 petroleum resin, cumarone resin, etc. It may be added. In particular, when the adherend is a polyolefin, a rosin-based resin or a petroleum-based resin is preferably used because strong adhesion can be exhibited.

To enhance coatability, thickeners such as acrylic rubber, epichlorohydrin rubber, isoprene rubber, and butyl rubber; thixotropic agents such as colloidal silica and polyvinylpyrrolidone; extenders such as calcium carbonate, titanium oxide and clay ; Polyester, (meta)
A modifier such as an acrylic polymer, polyurethane, silicone, polyether, polyvinyl ether, polyvinyl chloride, polyvinyl acetate, polyisobutylene, or waxes may be added.

Further, when the photocurable composition according to the present invention is used as an adhesive, an inorganic hollow body such as a glass balloon, an alumina balloon, a ceramic balloon, and the like; Organic hollow bodies such as organic hollow bodies such as vinylidene chloride balloons and acrylic balloons; single fibers such as glass, polyester, rayon, nylon, cellulose and acetate may be added.

When the above glass fibers are blended, fibrous chips can be added to the composition. However, high shearing force can be obtained by impregnating the above-mentioned photocurable composition into a glass woven fabric and polymerizing it. Adhesive strength can be obtained.

For the purpose of improving photosensitivity, anthracene, perylene, coronene, tetracene, benzanthracene, phenothiazine, flavin, acridine, ketocoumarin, thioxanthone derivative, benzophenone,
Acetophenone, 2-chlorothioxanthone, 2,4-
A sensitizer such as dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, or isopropylthioxanthone may be appropriately added.

For the purpose of adjusting the time from the irradiation of light until the bonding becomes possible, that is, the pot life, 12-crown-4, 15-crown-5, 18-crown-6,
24-crown-8, 30-crown-10, 2-aminomethyl-12-crown-4, 2-aminomethyl-1
5-crown-5, 2-aminomethyl-18-crown-6, 2-hydroxymethyl-12-crown-4,2
-Hydroxymethyl-15-crown-5, 2-hydroxymethyl-18-crown-6, dicyclohexano-
18-crown-6, dicyclohexano-24-crown-8-dibenzo-18-crown-6, dibenzo-2
4-crown-8, dibenzo-30-crown-10,
Benzo-12-crown-4, benzo-15-crown-5, benzo-18-crown-6,4'-aminobenzo-15-crown-5,4'-bromobenzo-15-
Crown-5,4'-formylbenzo-15-crown-5,4'-nitrobenzo-15-crown-5, bis [(benzo-15-crown-5) -15-ylmethyl] pimelate, poly [(dibenzo- 18-Crown-
6) -co-formaldehyde] or a compound having a cyclic ether structure, or a polyether such as polyethylene glycol, polypropylene glycol or polytetrahydrofuran.

(Processed article using photo-post-curable pressure-sensitive adhesive composition) The photo-post-curable pressure-sensitive adhesive composition according to the present invention may be in the form of a sheet, or may be formed on at least one surface and a part of a substrate. A light post-curing adhesive sheet may be formed by laminating.
Examples of the base material include various nonwoven fabrics such as rayon or cellulose, films or sheets made of various synthetic resins such as polyethylene, polyester, polystyrene, cellophane, polypropylene, and polyimide; foamed polyethylene, urethane foam, and foamed vinyl chloride. Foam, polyethylene, polyester, polystyrene,
Acrylic, ABS, polypropylene, rigid vinyl chloride,
A synthetic resin plate made of various synthetic resins such as polycarbonate, a sheet or plate made of various metals such as steel, stainless steel, aluminum, copper, and plated steel plate, glass, ceramics, wood, paper, cloth, and the like can be used. It is not something to be done. Further, the shape of the base material is not limited to a thin shape such as a sheet shape or a plate shape, and may be any shape such as a prism shape, a rod shape, and a shape having an aspheric surface.

(Method of joining members) Light post-curing according to the present invention
When members are joined using a mold adhesive composition,
Apply the curable pressure-sensitive adhesive composition to at least one of the members
Before or after coating, 300 nm or more and less than 800 nm
In the wavelength range of 5 mW / cm ^Twothat's all
Irradiate light, and after light irradiation, both members can be joined.
preferable. 50mW / cm^TwoIf less than
It is difficult to sufficiently activate the polymerization initiator (B).
Sometimes.

Examples of the light source for exposing the photocurable composition according to the present invention include excimer laser, low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high-pressure mercury lamp, chemical lamp, black light lamp, and microwave excitation. Examples include a mercury lamp, a metal halide lamp, a fluorescent lamp, and natural light such as sunlight.

(Function) In the photo-curable pressure-sensitive adhesive composition according to the first aspect of the present invention, the polymerization initiator (B) is activated by light irradiation, and the cation of the cationic polymerizable compound (A) is activated. The polymerization proceeds and is polymerized and cured. The polymer (C) is blended so that the photo-curable pressure-sensitive adhesive composition containing the cationically polymerizable compound (A), the polymerization initiator (B) and the polymer (C) exhibits tackiness. In the initial state, it has a sufficient initial cohesive strength and adhesive strength. Therefore, the work such as the temporary fixing and the temporary process can be performed using the adhesive force.

Therefore, the adhesive can be easily applied to the adherends by utilizing the adhesive force, and is polymerized and cured by the above-mentioned irradiation of light, so that the adherends can be firmly joined after curing. .

In addition, according to the first aspect of the present invention, after the polymerization initiator (B) is activated by light irradiation,
At a time in the range of 5 minutes to 5 hours, the conversion of the cationically polymerizable compound (A) exceeds 10%.
Since the conversion rate of the cationically polymerizable compound (A) after curing for 50 days becomes 50% or more, the adhesive strength is maintained for a while after light irradiation, and the pot life is sufficient to allow the bonding operation to be performed with a margin. While ensuring excellent adhesive strength after curing.

Further, in the invention according to the second aspect, the light post-curing type pressure-sensitive adhesive composition is irradiated with light to activate the polymerization initiator (B) at 25 ° C. for 5 minutes to 5 hours. In time, since the dynamic shear storage modulus at 25 ° C. exceeds 10 times the dynamic shear storage modulus before light irradiation, the adhesive force is maintained for a while after the light irradiation, and the joining operation can be performed with a margin. It is possible to secure a pot life of the order.

Further, after curing at 25 ° C. for 7 days,
Since the dynamic shear storage elastic modulus at a frequency of 0.1 Hz and 25 ° C. is in the range of 10 ⁶ to 10 ⁸ Pa, the elastic modulus is increased, and the adherends are firmly joined.

In addition, the dynamic shear storage modulus of the light post-curable pressure-sensitive adhesive composition before use in the temperature range from 0.1 Hz to 0 to 50 ° C. is in the range of 10 ³ to 10 ⁶ Pa. It is soft enough before use and can therefore be easily applied to adherends.

According to the third aspect of the present invention, an epoxy group-containing compound is used as the cationically polymerizable compound (A), and is cured by ring-opening polymerization of an epoxy group. Give things. Compound (C1) wherein polymer (C) has at least one (meth) acryloyl group and at least one hydroxyl group
And a polymer having a compound (C) having an unsaturated bond copolymerizable with the compound (C1), so that not only a sufficient pot life can be ensured, but also the light The curable pressure-sensitive adhesive composition cures. Accordingly, it is possible to ensure both the pot life and the quick curing property.

In the method for joining members according to the fourth aspect of the present invention, before or after applying the photo-curable pressure-sensitive adhesive composition according to the present invention to the member, the thickness is 300 nm or more and 800 nm or more.
When the photocationic polymerization catalyst is used as the polymerization initiator (B), the photocationic polymerization catalyst is sufficiently activated because the light in the wavelength region of less than 5 mW / cm ² is irradiated with the light. As a result, the polymerization and curing of the cationically polymerizable compound (A) proceed quickly and reliably, and the curing of the photo-curable pressure-sensitive adhesive composition proceeds promptly. Therefore, the members can be firmly joined.

Further, since the photo-curable pressure-sensitive adhesive composition according to the present invention has a sufficient initial cohesive force and pressure-sensitive adhesive strength in the initial state, the members can be easily connected to each other without the need for complicated temporary fixing work. Can be joined.

[0097]

The present invention will be described in more detail by way of the following non-limiting examples.

(Evaluation Method) In the following Examples and Comparative Examples, the conversion of epoxy groups, SUS
The shear adhesive strength, the pot life, and the elastic modulus (Example 4 and Comparative Example 2) were evaluated.

Epoxy Conversion The epoxy conversion was calculated first, including the amount of epoxy groups contained in the composition. That is, the content of the epoxy group in the photo-curable pressure-sensitive adhesive is determined by adding a predetermined amount of the pressure-sensitive adhesive to a dioxane solution of hydrogen chloride and ethanol at a ratio of 1: 1 and stirring at room temperature for about 5 hours. Unreacted hydrogen chloride was determined by back titration with potassium hydroxide. The formula for calculating the epoxy group content (Zmol / g) is as follows. Z (mol / g) = (S2−S1) × C × f / (Ws ×
1000) S1 (mL): Titration of potassium hydroxide in ethanol solution required for this test S2 (mL): Titration of potassium hydroxide in ethanol solution required for blank test C (mol / L): For titration F: Factor of potassium hydroxide ethanol solution used for titration Ws (g): Amount of titration sample to be collected However, if the titration sample contains an acid such as a carboxyl group, the acid is used in advance. Is determined, and a value obtained by subtracting the value from Z is the epoxy group content.

Therefore, the conversion of the epoxy group (Conv
(%)) Was determined by the following equation. Conv = (Z0-Z1) / Z0 × 100 Z0 (mol / g): epoxy group content of the post-curing pressure-sensitive adhesive before light irradiation Z1 (mol / g): when a predetermined time has elapsed after light irradiation Epoxy group content of light post-curing adhesive

Shear adhesive strength The photo-curable pressure-sensitive adhesive sheets obtained in Examples 1 to 3 and Comparative Example were cut into a size of 25 mm × 25 mm, polished with a water-resistant abrasive paper # 280, and the surface thereof was ethyl acetate. Attached on a degreased and dried stainless steel plate (SUS304, hereinafter abbreviated as A) having a width of 30 mm, a length of 150 mm and a thickness of 2 mm. Light having a light intensity of 30 mW / cm ^{2 in} a wavelength region of 300 nm to 370 nm was irradiated to the applied photocurable pressure-sensitive adhesive sheet for 30 seconds. Immediately after the light irradiation, the polyethylene terephthalate film coated on the curable pressure-sensitive adhesive sheet was peeled off, and another adherend A was bonded to obtain a bonded shear adhesion test piece. The measurement of the shear adhesive strength was performed after curing for 7 days after bonding, and then JIS Z 685
Tensile strength using a tensile tester according to 0
The shear adhesion was measured at mm / min.

Pot life In the above-mentioned evaluation of the shear adhesive strength, the curable pressure-sensitive adhesive sheet stuck on the adherend A was irradiated, and after a lapse of a predetermined time, another adherend A was irradiated.
For the purpose of the present invention, it can be evaluated that there is an effect if the shearing adhesive force is almost equal to that obtained when bonding is performed immediately after irradiation, even if a long time has elapsed after irradiation. Therefore, the time from the longest light irradiation to the bonding, which can be evaluated as having an effect, was taken as the pot life.

Elastic Modulus The dynamic shear storage modulus was measured by Rheometrics.
Using a viscoelasticity spectrometer RDA-II, the sample was sandwiched between φ25 mm aluminum plate plates under the measurement conditions of a measurement temperature of 25 ° C., an applied frequency of 0.1 Hz and an applied strain of 2.0%.

Example 1 In a 2 L separable flask, 500 g of ethyl acrylate and 5 epoxy resins (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.)
00g and bis (2,6-dimethoxybenzoyl)-
2,4,4-trimethylpentylphosphine oxide (Ciba Geigy, trade name: Irgacure 1700)
1 g of a polymerization initiator (B) (manufactured by Asahi Denka Kogyo KK, trade name:
5 g of Optomer SP-170) and 50 g of polypropylene glycol (number-average molecular weight 2000) were stirred until uniform, mixed, and then bubbled with nitrogen gas for 20 minutes to remove dissolved oxygen, thereby allowing photopolymerization. The composition was obtained.

The above photopolymerizable composition was coated on a polyethylene terephthalate file whose surface had been release treated to a thickness of 0.1 μm.
Coating was performed so as to be 3 mm. Another polyethylene terephthalate film, the surface of which was release-treated, was overlaid on the applied coating film to cover the coating film. Thus, a laminate in which the photopolymerizable composition layer was sandwiched between the polyethylene terephthalate films was obtained.

A fluorescent lamp having a maximum emission wavelength at 400 nm was used for the above-mentioned laminate, and near-ultraviolet rays substantially containing no light in a wavelength region of 370 nm or less were irradiated with a light intensity of 1 mW / cm.
² so as to be irradiated 10 minutes to obtain a light cured adhesive composition comprising been formed into a sheet.

The sheet-shaped photo-curable pressure-sensitive adhesive composition was irradiated with light using a high-pressure mercury lamp so that the light intensity was 30 mW / cm ² for 30 seconds to activate the polymerization initiator (B). Then, after 30 minutes at 25 ° C., a sample was cut out from the photo-cured pressure-sensitive adhesive composition sheet, and the conversion of the epoxy group was measured. In this case, the conversion of the epoxy group is 1
It was 5% and exceeded 10% (the conversion of the epoxy group after 5 minutes of light irradiation was 5%).

Further, after irradiating with the above-mentioned high-pressure mercury lamp and curing at 25 ° C. for 7 days, a sample was cut out again from the photo-curable pressure-sensitive adhesive composition sheet, and the conversion of epoxy groups was measured. , 80%.

The post-curing pressure-sensitive adhesive composition sheet had a shear adhesion before curing of 0.5 kgf / cm ² and a curing adhesion after curing for 7 days after light irradiation of 30 kgf / cm ² .
The pot life was 40 minutes.

Example 2 In a 2 L separable flask, 500 g of ethyl acrylate and 5 epoxy resins (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.)
00g and bis (2,6-dimethoxybenzoyl)-
2,4,4-trimethylpentylphosphine oxide (Ciba Geigy, trade name: Irgacure 1700)
1 g of a polymerization initiator (B) (manufactured by Asahi Denka Kogyo KK, trade name:
5 g of Optomer SP-170) and dicyclohexano-
Stir 5 g of 18-crown-6 until uniform,
After mixing, dissolved oxygen was removed by bubbling with nitrogen gas for 20 minutes to obtain a photopolymerizable composition.

The above photopolymerizable composition was coated on a polyethylene terephthalate file whose surface had been release-treated to a thickness of 0.1 mm.
Coating was performed so as to be 3 mm. Another polyethylene terephthalate film, the surface of which was release-treated, was overlaid on the applied coating film to cover the coating film. Thus, a laminate in which the photopolymerizable composition layer was sandwiched between the polyethylene terephthalate films was obtained.

A fluorescent lamp having a maximum emission wavelength at 400 nm was used for the above-mentioned laminate, and near-ultraviolet light substantially not containing light in a wavelength region of 370 nm or less was irradiated with a light intensity of 1 mW / cm.
² so as to be irradiated 10 minutes to obtain a light cured adhesive composition comprising been formed into a sheet.

The sheet-shaped photo-curable pressure-sensitive adhesive composition was irradiated with light for 30 seconds using a high-pressure mercury lamp so that the light intensity became 30 mW / cm ² to activate the polymerization initiator (B). Thereafter, after 60 minutes at 25 ° C., a sample was cut out from the photo-cured pressure-sensitive adhesive composition sheet, and the conversion of the epoxy group was measured. In this case, the conversion of the epoxy group is 2
It was 0% and exceeded 10% (the conversion of the epoxy group after 5 minutes of light irradiation was 5%).

Furthermore, after irradiating with the above-mentioned high-pressure mercury lamp and curing at 25 ° C. for 7 days, a sample was cut out again from the photo-curable pressure-sensitive adhesive composition sheet, and the conversion of the epoxy group was measured. , 80%.

The shear adhesive strength before curing of the pressure-sensitive adhesive composition sheet after curing was 0.9 kgf / cm ² , and the shear adhesive strength after curing for 7 days after light irradiation was 40 kgf / cm ² .
The pot life was 80 minutes.

Example 3 In a 2 L separable flask, 300 g of tetrahydrofurfuryl acrylate was added.
200 g of Praxel FM-1D (compound 2 described above, n = 1, manufactured by Daicel Chemical Industries) and 500 g of epoxy resin (manufactured by Yuka Shell Epoxy, trade name: Epicoat 828)
And bis (2,6-dimethoxybenzoyl) -2,4
1 g of 4-trimethylpentylphosphine oxide (manufactured by Ciba Geigy, trade name: Irgacure 1700), 5 g of polymerization initiator (B) (manufactured by Asahi Denka Kogyo, trade name: Optomer SP-170), and dicyclohexano-18- After stirring and mixing 5 g of Crown-6 until uniform, the dissolved oxygen was removed by bubbling with nitrogen gas for 20 minutes to obtain a photopolymerizable composition.

The above photopolymerizable composition was coated on a polyethylene terephthalate file whose surface had been release treated to a thickness of 0.1 μm.
Coating was performed so as to be 3 mm. Another polyethylene terephthalate film, the surface of which was release-treated, was overlaid on the applied coating film to cover the coating film. Thus, a laminate in which the photopolymerizable composition layer was sandwiched between the polyethylene terephthalate films was obtained.

A fluorescent lamp having a maximum emission wavelength of 400 nm was used for the laminate, and near-ultraviolet light substantially not containing light in a wavelength range of 370 nm or less was irradiated with a light intensity of 1 mW / cm.
² so as to be irradiated 10 minutes to obtain a light cured adhesive composition comprising been formed into a sheet.

The sheet-shaped photo-curable pressure-sensitive adhesive composition was irradiated with light for 30 seconds using a high-pressure mercury lamp so that the light intensity became 30 mW / cm ² , thereby activating the polymerization initiator (B). Thereafter, after 60 minutes at 25 ° C., a sample was cut out from the photo-cured pressure-sensitive adhesive composition sheet, and the conversion of the epoxy group was measured. In this case, the conversion of the epoxy group is 1
It was 5% and exceeded 10% (the conversion of the epoxy group after 5 minutes of light irradiation was 7%).

Furthermore, after irradiating with the above-mentioned high-pressure mercury lamp and curing at 25 ° C. for 7 days, a sample was cut out again from the photo-curable pressure-sensitive adhesive composition sheet, and the conversion of the epoxy group was measured. , 98%.

[0121] Shear adhesive strength before curing of the light cured pressure-sensitive adhesive composition sheet is 0.8 kgf / cm ^2, a shear adhesive strength 7 days after curing after light irradiation was 80 kgf / cm ^2.
The pot life was 80 minutes.

Comparative Example 1 In a 2 L separable flask, 500 g of ethyl acrylate and 5 epoxy resins (trade name: Epicoat 828, manufactured by Yuka Shell Epoxy Co., Ltd.)
00g and bis (2,6-dimethoxybenzoyl)-
2,4,4-trimethylpentylphosphine oxide (Ciba Geigy, trade name: Irgacure 1700)
1 g of a polymerization initiator (B) (manufactured by Asahi Denka Kogyo KK, trade name:
5 g of Optomer SP-170) were stirred until uniform, mixed, and then bubbled with nitrogen gas for 20 minutes to remove dissolved oxygen and obtain a photopolymerizable composition.

The above photopolymerizable composition was coated on a polyethylene terephthalate file whose surface had been release-treated to a thickness of 0.1 μm.
Coating was performed so as to be 3 mm. Another polyethylene terephthalate film, the surface of which was release-treated, was overlaid on the applied coating film to cover the coating film. Thus, a laminate in which the photopolymerizable composition layer was sandwiched between the polyethylene terephthalate films was obtained.

A fluorescent lamp having a maximum emission wavelength of 400 nm was used for the above-mentioned laminate, and near-ultraviolet rays substantially containing no light in a wavelength region of 370 nm or less were emitted at a light intensity of 1 mW / cm.
² so as to be irradiated 10 minutes to obtain a light cured adhesive composition comprising been formed into a sheet.

The sheet-like photo-curable pressure-sensitive adhesive composition was irradiated with light using a high-pressure mercury lamp so that the light intensity was 30 mW / cm ² for 30 seconds to activate the polymerization initiator (B). Then, after 30 minutes at 25 ° C., a sample was cut out from the photo-cured pressure-sensitive adhesive composition sheet, and the conversion of the epoxy group was measured. In this case, the conversion of the epoxy group is 2
At 5%, it exceeded 10%.

Further, after irradiating with the above-mentioned high-pressure mercury lamp and curing at 25 ° C. for 7 days, a sample was cut out again from the photo-curable pressure-sensitive adhesive composition sheet, and the conversion of the epoxy group was measured. , 80%.

The post-curing pressure-sensitive adhesive composition sheet had a shear adhesive strength before curing of 0.5 kgf / cm ² and a curing adhesive strength after curing for 7 days after light irradiation of 40 kgf / cm ² .
The pot life was 5 minutes.

Example 4 300 g of tetrahydrofurfuryl acrylate was placed in a 2 L separable flask.
200 g of PLACCEL FM-5D (the above-mentioned compound 2, wherein n = 1, manufactured by Daicel Chemical Industries, Ltd.) and an epoxy resin (manufactured by Yuka Shell Epoxy Co., trade name: Epicoat 82)
8) 500 g of bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide (Ciba Geigy, trade name: Irgacure 170)
0) 1 g, 5 g of a polymerization initiator (B) (manufactured by Asahi Denka Kogyo KK, trade name: Optomer SP-170), and 3 g of dicyclohexano-18-crown-6 were stirred and mixed until uniform. The dissolved oxygen was removed by bubbling with a nitrogen gas for 20 minutes to obtain a photopolymerizable composition.

Using the above photopolymerizable composition, a photocurable pressure-sensitive adhesive composition sheet was obtained in the same manner as in Example 1. The frequency of the light post-curing pressure-sensitive adhesive composition sheet was 0.1 Hz and 2 Hz.
The dynamic shear storage modulus at 5 ° C. was 8 × 10 ³ Pa.

The photo-curable pressure-sensitive adhesive composition sheet was irradiated with light having a wavelength of 365 nm for 30 seconds using a high-pressure mercury lamp so that the light intensity became 30 mW / cm ² , thereby activating the polymerization initiator (B). After 25 minutes at 25 ° C., 0.1
When the dynamic shear storage elastic modulus at 25 Hz and 25 ° C. was measured, the dynamic shear storage elastic modulus before light irradiation was 1 at 10 ⁵ Pa.
It was confirmed that it exceeded 0 times (the elastic modulus after 5 minutes of light irradiation was 10 ⁴ Pa). Furthermore, after irradiating with light to activate the polymerization initiator (B), after curing at 25 ° C. for 7 days, the dynamic shear storage modulus at a frequency of 0.1 Hz and 25 ° C. was measured. It was ⁷ Pa.

Using the above-mentioned photo-post-curable pressure-sensitive adhesive composition sheet, when the shear adhesive strength was evaluated in the same manner as in Example 1, the shear adhesive strength before curing was 0.8 kgf / cm ^2. Adhesive strength after curing for 7 days at 80 kgf /
cm ² . In addition, when the pot life was evaluated in the same manner as in Example 1, it was 80 minutes.

(Comparative Example 2) In a 2 L separable flask, 300 g of tetrahydrofurfuryl acrylate was added.
200 g of PLACCEL FM-5D (the above-mentioned compound 2, wherein n = 1, manufactured by Daicel Chemical Industries, Ltd.) and an epoxy resin (manufactured by Yuka Shell Epoxy Co., trade name: Epicoat 82)
8) 500 g of bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide (Ciba Geigy, trade name: Irgacure 170)
0) 1 g of the polymerization initiator (B) (trade name: Optomer SP-170, manufactured by Asahi Denka Kogyo Co., Ltd.) was stirred and mixed until uniform, followed by bubbling with nitrogen gas for 20 minutes. The dissolved oxygen was removed to obtain a photopolymerizable composition.

Using the above photopolymerizable composition, a photocurable PSA composition sheet was obtained in the same manner as in Example 1. The frequency of the light post-curing pressure-sensitive adhesive composition sheet was 0.1 Hz and 2 Hz.
The dynamic shear storage modulus at 5 ° C. was 8 × 10 ³ Pa.

The photo-curable pressure-sensitive adhesive composition sheet was irradiated with light having a wavelength of 365 nm for 30 seconds using a high-pressure mercury lamp so that the light intensity became 30 mW / cm ² , thereby activating the polymerization initiator (B). After 25 minutes and 1 minute, the dynamic shear storage modulus at 25 ° C. was measured. As a result, it was confirmed that the dynamic shear storage modulus before light irradiation exceeded 10 times at 10 ⁵ Pa. Was. Further, the above polymerization initiator (B)
After irradiating with light for activating, and after curing at 25 ° C. for 7 days, the dynamic shear storage modulus at a frequency of 0.1 Hz and 25 ° C. was measured to be 10 ⁷ Pa.

Using the above photocurable pressure-sensitive adhesive composition sheet, the shear adhesive strength was evaluated in the same manner as in Example 1. The shear adhesive strength before curing was 0.5 kgf / cm ^2. Adhesive strength after curing for 7 days at 40 kgf /
cm ² . Further, when the pot life was evaluated in the same manner as in Example 1, it was 5 minutes.

[0136]

According to the photo-curable pressure-sensitive adhesive composition according to the first aspect of the present invention, the cationically polymerizable compound (A)
, A polymerization initiator (B) and a polymer (C), and after irradiation with light, activates the polymerization initiator (B).
The conversion rate of the cationically polymerizable compound (A) exceeds 10% in a time period ranging from minutes to 5 hours, and the conversion rate of the cationically polymerizable compound (A) after curing at 25 ° C. for 7 days is 5%.
Since it is 0% or more, in the initial state, it has an adhesive strength enough to be temporarily fixed and temporarily fixed, can be easily applied to an adherend, and has an adhesive strength for a while after light irradiation. It is possible to secure a pot life that is long enough to allow the joining operation to be continued with a margin. In addition, after curing is completed, sufficient adhesive strength is exhibited.

In the photo-curable pressure-sensitive adhesive composition according to the second aspect, the cationically polymerizable compound (A)
And the polymerization initiator (B) and the polymer (C), and the dynamic shear storage modulus in the frequency range of 0.1 Hz and the temperature range of 0 to 50 ° C. is in the range of 10 ³ to 10 ⁶ Pa. In the initial state, it shows sufficient adhesiveness, and can be easily applied to an adherend, and since the adhesive force lasts for a while after light irradiation, the working time that can be performed with a margin for bonding work can be provided. It can be of sufficient length. Moreover, 25
Dynamic shear storage elastic modulus at 25 ° C in the range of 5 minutes to 5 hours at 10 ° C exceeds 10 times the elastic modulus before light irradiation, and after curing at 25 ° C for 7 days, frequency 0.1 Hz, 25 ° C.
Since the dynamic shear storage elastic modulus in the range of 10 ⁶ to 10 ⁸ Pa is in the range, a cured adhesive product that can exhibit sufficient adhesive strength is provided.

Therefore, by using the photo-post-curing pressure-sensitive adhesive composition according to the first and second aspects of the present invention, the adherends can be easily temporarily fixed without performing a complicated temporary fixing operation. In addition, since a sufficient pot life after light irradiation is secured, the joining operation can be performed with a margin. Further, after the curing is completed, the adherends can be firmly joined to each other in order to give a strong adhesive cured product.

Continued on front page F-term (reference) 4J036 AD08 AF06 AJ08 AK03 AK04 FB03 FB18 GA22 GA24 HA02 JA06 4J040 DA002 DA142 DB021 DB031 DC022 DD051 DD052 DE022 DF042 DF052 EC041 EC061 EC071 EC091 EC151 EC211 GA351 EA002 002 002 KA13 KA14 LA06 PA32 PA38 PA41

Claims (4)

[Claims] 1. A polymerization method comprising: (A) a cationically polymerizable compound having at least one cationically polymerizable group in one molecule; and (B) polymerization for initiating polymerization of the cationically polymerizable compound (A) upon irradiation with light. A photo-curable pressure-sensitive adhesive composition comprising: an initiator; and (C) at least one polymer, wherein the pressure-sensitive adhesive composition is irradiated with light to activate the polymerization initiator (B). From 5 at 25 ° C
The conversion of the cationically polymerizable compound (A) exceeds 10% for a time in the range of
A photo-curable pressure-sensitive adhesive composition, wherein the conversion of the compound (A) after curing for one day is 50% or more. 2. (A) a cationically polymerizable compound having at least one cationically polymerizable group in one molecule, and (B) polymerization for initiating polymerization of the cationically polymerizable compound (A) by irradiation with light. A post-curing pressure-sensitive adhesive composition comprising: an initiator; and (C) at least one polymer, wherein the pressure-sensitive adhesive composition has a frequency of 0.1 H
z and the dynamic shear storage modulus in the temperature range of 0 to 50 ° C. are in the range of 10 ³ to 10 ⁶ Pa, and after activating the polymerization initiator (B) by irradiation with light, 5 minutes at 25 ° C. ~ 5
In the time range of 25 hours, the dynamic shear storage modulus at 25 ° C. exceeds 10 times the dynamic shear storage modulus before light irradiation, and after a further 7 days curing at 25 ° C., the frequency is increased to 0.1%.
Dynamic shear storage modulus at 1 Hz and 25 ° C. is 10 ⁶
A photo-curable pressure-sensitive adhesive composition, wherein the pressure-sensitive adhesive composition is in the range of from 10 to 10 ⁸ Pa. 3. The cationically polymerizable group of the cationically polymerizable compound (A) is an epoxy group, and the polymer (C) has at least one compound per (C1) molecule.
2. A polymer comprising a compound having two (meth) acryloyl groups and at least one hydroxyl group, and a compound having an unsaturated bond copolymerizable with the compound (C2) (C2). Or the photo-curable pressure-sensitive adhesive composition according to 2. 4. Before or after application of the photo-curable pressure-sensitive adhesive composition according to claim 1 on at least one of the members to be joined, 300 nm or more, 800 n.
A method for joining members, comprising irradiating light of less than m to a light intensity of 5 mW / cm ² or more, and joining the members after light irradiation.