JP3043292B2 - Energy polymerizable composition and curable adhesive sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an energy-polymerizable composition, and more particularly to an energy-polymerizable composition which is polymerized in two different polymerization modes, for example, having a tackiness in a normal state. The present invention relates to an energy-polymerizable composition that can be suitably used for a curable pressure-sensitive adhesive sheet that can be cured after application, and a curable pressure-sensitive adhesive sheet using the energy-polymerizable composition.

[0002]

2. Description of the Related Art Acrylic pressure-sensitive adhesives have heat resistance, weather resistance,
Because of its excellent oil resistance, it is widely used for various adhesive processed products such as adhesive tape. However, an acrylic pressure-sensitive adhesive is designed to have a low elastic modulus as a physical property in order to develop a pressure-sensitive adhesive force. Therefore, it is difficult to develop high bonding strength such as adhesives, and it is used for applications that require high bonding strength, such as bonding steel plates for vehicles, structural members for houses and buildings, and housing members. Could not.

Therefore, a pressure-sensitive adhesive has been proposed which has both easy workability and high bonding strength and coating strength as high as that of an adhesive, and is excellent in safety because it contains no volatile components. For example, JP-A-2-272076 discloses that
An adhesive tape using a pressure-sensitive thermosetting adhesive composed of a photopolymerizable composition containing an acrylate monomer and an epoxy resin is disclosed. Here, it is stated that only the acrylate monomer in the photopolymerizable composition is polymerized to form an adhesive tape, and the epoxy resin is cured by heating after application, thereby increasing the adhesive strength.

However, in the method described in JP-A-2-272076, since heat is used for curing the epoxy resin, a material having poor heat resistance cannot be used as the adherend. However, there is a problem that the material is limited.

On the other hand, JP-A-5-506465 discloses a photosensitive composition comprising a photoradical polymerization component such as an acrylate monomer, a photocationic polymerization component such as an epoxy compound, and an organometallic complex polymerization initiator. A pressure-sensitive adhesive is disclosed. This pressure-sensitive adhesive has been proposed in order to increase the adhesive force, and in the production stage of the pressure-sensitive adhesive, both photoradical polymerization and photocation polymerization proceed, and these polymerization reactions are carried out. This is completed when the pressure-sensitive adhesive is formed into a sheet or the like. That is,
The obtained pressure-sensitive adhesive sheet is configured to have sufficient strength in advance. Therefore, when bonding to an adherend, a sufficient adhesive strength can be expected, but even when an external stimulus such as heat or light is applied, no further improvement in the adhesive strength can be expected.

[0006] Epoxy resin adhesives are excellent in creep resistance, light resistance, water resistance, heat resistance, chemical resistance, etc., have high adhesive strength, and are widely used in metals, plastics, glasses and the like. Since various materials can be adhered, it is widely used for attaching various joining members.

However, the epoxy resin adhesive is
Generally, since it is used in a liquid form, there are problems that coating unevenness occurs at the time of coating, the appearance of the joint end face is impaired due to spotting due to excessive coating, and it is not possible to apply the coating once again to the surface once applied. Was. Further, the epoxy resin adhesive is mainly configured as a two-part adhesive, and since the mixing ratio between the main agent and the curing agent is limited, attention must be paid to the mixing ratio when used.
In some cases, the desired adhesive strength could not be achieved due to an incorrect mixing ratio.

Therefore, a sheet-like epoxy adhesive formed by molding an epoxy resin-based adhesive into a sheet or film has been proposed (Japanese Patent Application Laid-Open No. 60-173076). However, the sheet-like epoxy adhesive has a high elastic modulus in a normal state and a low initial tackiness. Therefore, there is a problem that the sheet-like epoxy adhesive does not have a temporary fixing property and the workability at the time of joining is not sufficient. In addition, since the adhesiveness to the adherend is not sufficient, the adhesive must be adhered to the adherend under severe conditions such as high temperature and high pressure press, and the adherence does not have resistance to such processing conditions. Could not be applied to kimono.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a coating composition which has a sufficient initial adhesive strength under normal conditions, shortens the curing time until reaching the maximum adhesive strength by applying energy, and is easily cured. Can be suitably used for the bonding of members having insufficient heat resistance, and does not require severe conditions such as high temperature or high pressure pressing at the time of application, and is suitable for obtaining a curable adhesive sheet. An object of the present invention is to provide an energy polymerizable composition and a curable adhesive sheet using the energy polymerizable composition.

[0010]

SUMMARY OF THE INVENTION Although not yet known, the present inventors utilize two different polymerization modes,
An energy polymerizable composition that can be used as an adhesive is previously proposed. Here, a monomer for constituting an adhesive component such as an acrylic monomer, a polymerization initiator for polymerizing the monomer, a compound having an epoxy group, and a compound having an epoxy group are cured by ring-opening polymerization. Polymerizable composition containing a polymerization initiator. After the composition is formed into a sheet, the above-mentioned monomer is polymerized into a tacky polymer to form an adhesive sheet. When using the above-mentioned adhesive sheet, the ring-opening polymerization of the compound having an epoxy group is advanced by applying energy to cure the compound. However, there has been a problem that curing of a compound having an epoxy group requires a long time curing after applying energy. Further, it has been desired to further improve the adhesive force by the final cured adhesive.

Although not yet known, the inventors of the present application have previously disclosed that they can be used for joining members having insufficient heat resistance and do not require severe bonding conditions such as a high-temperature and high-pressure press. A curable adhesive sheet containing an acrylic polymer, a compound having an epoxy group, and a compound which is irradiated with light to induce ring opening of the epoxy group has been proposed as a curable adhesive sheet that can be used for the above method. In this curable pressure-sensitive adhesive sheet, the compound having an epoxy group is cured by light irradiation. Therefore, before or after the curable pressure-sensitive adhesive sheet is adhered to the adherend, the curable pressure-sensitive adhesive sheet is simply irradiated with light. The curable adhesive sheet can be firmly joined to the adherend, and the heat resistance of the adherend does not matter. In addition, since the acrylic polymer has a sufficient initial adhesive strength, the adhesiveness when affixing to an adherend is also enhanced.

However, when light is applied to the curable pressure-sensitive adhesive sheet, the curing reaction proceeds simultaneously with the light irradiation, and the elasticity of the curable pressure-sensitive adhesive sheet increases in a relatively short time. In some cases, the adhesiveness to the toner was reduced. Therefore, if the adherends are not joined to each other using the curable adhesive sheet immediately after the light irradiation, sufficient adhesive strength may not be obtained.

The present invention has been made to solve the problems of the above-mentioned curable adhesive sheet and the energy-polymerizable composition used therein which are not yet known. That is, an object of the present invention is to provide an energy-polymerizable composition and a curable adhesive sheet capable of shortening the curing time after energy application and improving the adhesive strength.

The invention according to claim 1 isPost-curing adhesive
An energy polymerizable composition for obtaining an agent,
(A) at least one (meth) acryloyl in one molecule
A compound having a hydroxyl group and at least one hydroxyl group,
(B) having an unsaturated bond copolymerizable with the compound (A)
CompoundWith respect to the compound (B) of the compound (A)
The ratio is in the range of 10/30 to 60/30 by weight,
(C) contains at least one epoxy group in one molecule
A compound and (D)Light irradiationCompounds (A) and (B)
(E) a polymerization initiator for initiating the polymerization ofLight irradiationBy
Polymerization to initiate ring-opening polymerization of epoxy group of compound (C)
With initiatorfurtherEnergy polymerization characterized by including
The composition is an acidic composition.

Further, in the invention described in claim 2, the polymerization initiator (D) is a polymerization initiator that starts the polymerization of the compounds (A) and (B) by irradiating light, and the polymerization initiator ( E) is a polymerization initiator that initiates ring-opening polymerization of the epoxy group of compound (C) by light irradiation.

According to the third aspect of the present invention, the polymerization initiator (D) is activated by irradiating light having a wavelength of 370 nm or more and 800 nm or less, and the polymerization initiator (E) becomes 300 nm or more. Activated by irradiation with light having a wavelength of less than 370 nm.

The invention according to claim 4 corresponds to a composition obtained by copolymerizing the compounds (A) and (B) in the energy polymerizable composition according to the invention according to claim 1, and corresponds to one molecule. Compound (A) having therein at least one (meth) acryloyl group and at least one hydroxyl group
And the compound (B) having an unsaturated bond copolymerizable with the compound (A) are formed by the compound (A) with respect to the compound (B).
The ratio will be in the range of 10/30 to 60/30 by weight.
A copolymer formed by Uni copolymerization initiator compounds one containing at least an epoxy group and (C), the ring-opening polymerization of the epoxy group of the compound from <br/> light irradiation (C) in a molecule And a polymerization initiator (E).

In the invention according to claim 5, the polymerization initiator (E) is activated by irradiation with light having a wavelength of 300 nm or more and less than 370 nm. The composition is an acidic composition.

According to a sixth aspect of the present invention, there is provided a curable adhesive sheet comprising the energy polymerizable composition according to the fourth or fifth aspect .

Hereinafter, the present invention will be described in detail. Compound (A) In the present invention, at least one (meth)
The compound (A) having an acryloyl group and at least one hydroxyl group is used to form a high molecular weight polymer as an adhesive component by being copolymerized with a compound (B) described later. The compound (A) is not particularly limited as long as it has at least one (meth) acryloyl group and at least one hydroxyl group in one molecule. Examples of compounds that can be used as compound (A) include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 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-hydroxyethylphthalic acid, 2-[(meth) acryloyloxy] ethyl-2-hydroxypropylphthalic acid,

[0021]

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[0022]

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[0023]

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[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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The above compounds 1 to 10 are preferably used since high cohesion can be obtained when a high molecular weight polymer is used. The compound (A) may be used alone or in combination of two or more.

Compound (B) The compound (B) is not particularly limited as long as it is a copolymerizable monomer having an unsaturated bond copolymerizable with the compound (A). The compound which is non-reactive with the epoxy group in the constituent compound (C) is preferable from the viewpoint of enhancing storage stability. From such a viewpoint, compounds such as a carboxyl group-containing compound such as acrylic acid and methacrylic acid, and a compound such as maleic anhydride having an acid anhydride skeleton are not preferred.

Examples of compounds that can be used as compound (B) include methyl (meth) acrylate and ethyl (meth)
Acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, tert-butyl (meth)
Acrylate, cyclohexyl (meth) 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 ,

[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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(Meth) acrylonitrile, N-vinylpyrrolidone, N-acryloylmorpholine, N-vinylcaprolactone, N-vinylpiperidine, styrene, indene, α-methylstyrene, p-methylstyrene, p
-Chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, divinylbenzene, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, vinyl cinnamate and the like. These may be used alone or in combination of two or more.

Preferably, methyl (meth) acrylate, ethyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, or alcohol having a CO—C ether bond is used because of high polymerization reactivity. (Meth) acrylic acid esters are used.

Copolymerization ratio The copolymerization ratio of the compound (A) and the compound (B) is such that, even if a polymer having a sufficient cohesive force and initial tackiness is formed , both fast curing and adhesive force can be achieved. For the reason, the ratio (weight ratio) of compound (A) and compound (B)
Is selected to be in the range of 10/30 to 60/30.
You.

Compound (C) In the energy polymerizable composition according to the present invention, the compound (C) containing at least one epoxy group in one molecule comprises
It is used as a curing component when a curable adhesive sheet is formed. The compound (C) is not particularly limited as long as it has an epoxy group. For example, bisphenol A epoxy resin, hydrogenated bisphenol A
Epoxy resins, bisphenol F epoxy resins, novolak epoxy resins, aliphatic cyclic epoxy resins, brominated epoxy resins, rubber-modified epoxy resins, urethane-modified epoxy resins, glycidyl ester-based compounds, and the like. The compounds having an epoxy group may be used alone or in combination of two or more.

Polymerization Initiator (D) The polymerization initiator (D) is activated by the application of energy and is used to initiate the polymerization of the compounds (A) and (B). Examples of such a polymerization initiator (D) include a thermal radical polymerization initiator that is activated by applying thermal energy, a photoradical polymerization initiator that is activated by being irradiated with light, and the like.

As the thermal radical polymerization initiator, for example,
Peroxides such as benzoyl peroxide and cumene hydroperoxide; azo compounds such as azobisnitrile;

Examples of photo-radical polymerization initiators include acetophenone derivative compounds such as methoxyacetophenone; benzoin ether compounds such as benzoin propyl ether; ketal derivative compounds such as benzyl dimethyl ketal; phosphine oxide derivative compounds;
Bis (η5-cyclopentadienyl) titanocene derivative compounds and the like can be mentioned. The polymerization initiator (D) may be used alone or in combination of two or more.

Polymerization Initiator (E) The polymerization initiator (E) is not particularly limited as long as it is activated by applying energy and initiates ring-opening polymerization of the compound (C) having an epoxy group. Examples thereof include a thermal polymerization initiator activated by application of energy and a photopolymerization initiator activated by irradiation with light.

Examples of the thermal polymerization initiator include dicyandiamide, hydrazide, imidazole compound, amine adduct, amine imide, sulfonium salt, ammonium salt and pyridinium salt.

The photopolymerization initiator can be selected from heat-allene complex compounds, aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, pyridinium salts, aluminum complexes, silanols, and the like. As for the polymerization initiator (E), one type of polymerization initiator may be used, or a plurality of types of polymerization initiators may be used in combination.

Mixing ratio In the present invention, the mixing ratio of the polymer consisting of the compounds (A) and (B), the compound (C) having an epoxy group, and the polymerization initiator (E) is such that the adhesive force and Although not particularly limited, as long as a sufficient adhesive strength after activation energy application is obtained, preferably compound (A)
And 100 parts by weight of the polymer obtained from (B),
The compound having an epoxy group is blended in a proportion of 1 to 10000 parts by weight, and the polymerization initiator (E) is blended in a proportion of 0.01 to 1000 parts by weight.

When the compounding ratio of the compound having an epoxy group is 1
If the amount is less than 10 parts by weight, even if the compound having an epoxy group is cured by applying activation energy, sufficient adhesive strength may not be obtained.If the proportion of the compound having an epoxy group exceeds 10,000 parts by weight, In some cases, the mixing ratio of the polymer composed of the compounds (A) and (B) decreases, and sufficient tackiness may not be obtained. Further, when the compounding ratio of the polymerization initiator (E) is less than 0.01 part by weight, the compound (C) having an epoxy group may not be sufficiently polymerized even if activation energy is imparted, and thus, 1000 parts by weight. If it is added in excess of parts by weight, the proportion of the polymerization initiator will be too large, the consumption of epoxy will be too fast after light irradiation, curing will be completed before lamination, and sufficient adhesive strength will be obtained. And the adhesive strength after curing may not be high.

In the present invention, a vinyl ether compound may preferably be further added in order to lengthen the time from light irradiation to application, that is, the pot life, and the vinyl ether compound may further be added. In this case, the compound (C) having an epoxy group described above,
About the compounding ratio of the vinyl ether compound and the cationic photopolymerization initiator, preferably, 30 to 70 parts by weight of the epoxy group-containing compound (C), 1 to 30 parts by weight of the vinyl ether compound and 0 parts of the cationic photopolymerization initiator .0
It is 1 to 10 parts by weight.

When the compounding ratio of the epoxy group-containing compound is less than 30 parts by weight, even if it is cured, the original adhesive properties of the epoxy resin may not be exhibited. In some cases, the cohesive force of the sheet is reduced, and it is difficult to temporarily fix the sheet to an adherend, and improvement in workability may not be expected.

When the compounding ratio of the vinyl ether compound is less than 1 part by weight, the curing is substantially the same as that of the compound having an epoxy group alone, and when it exceeds 30 parts by weight, the cured product obtained by photocuring is not cured. In some cases, the strength becomes low and sufficient adhesive strength cannot be exhibited.

When the compounding ratio of the cationic photopolymerization initiator is 0.0
If the amount is less than 1 part by weight, the concentration of the cationically polymerizable species will be low even if photocured, and the curing speed may not be able to be set to an appropriate size. The curing proceeds rapidly on the surface of the pressure-sensitive adhesive sheet, and even when the composition contains a vinyl ether compound, the adhesion of the surface of the curable pressure-sensitive adhesive sheet to the adherend may decrease. Therefore, even though the mechanical strength of the final cured adhesive product is sufficient, the adhesive strength may not be sufficient. In the above preferable mixing ratio, a more preferable mixing ratio of the cationic photopolymerization initiator is 0.05 to 5 parts by weight, and further preferably 0.1 to 3 parts by weight.

Further, as for the polymer composed of the compounds (A) and (B), compounds 30 to 30 having an epoxy group can be used.
70 parts by weight, 1 to 30 parts by weight of the vinyl ether compound and 0.01 to 10 parts by weight of the cationic photopolymerization initiator,
It is preferable to mix in a proportion of 30 to 70 parts by weight. When the blending ratio of the polymer is less than 30 parts by weight, the cohesive force of the curable adhesive sheet is reduced, so that the temporary fixing to the adherend becomes impossible, and improvement in workability may not be expected.
If the amount is more than 0 parts by weight, the original adhesiveness of the epoxy resin may not be expected.

Other additives In the curable pressure-sensitive adhesive sheet according to the present invention, if necessary, heat resistance and cohesive strength at high temperatures may be improved as long as the object of the present invention is not impaired. One or more crosslinkable monomers such as a functional acrylate monomer or a polyfunctional vinyl monomer may be contained.

The crosslinkable monomer is not particularly restricted but includes, for example, hexanediol di (meth) acrylate, ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate. ) 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, Examples thereof include dipentaerythritol hexa (meth) acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate, and one or more of these are suitably used.

Other Components In the energy polymerizable composition according to the present invention, in addition to the compounds (A), (B), (C) and the polymerization initiators (D), (E), the present invention Known tackifying resins, extenders, and the like may be appropriately blended as long as the object of the present invention is not impaired.

For example, rosin-based resins, modified rosin-based resins, terpene resins, terpene phenolic resins, aromatic modified terpene resins, C5-based or C9-based resins are used for the purpose of improving the tackiness of the curable adhesive sheet of the present invention. And a tackifier resin such as petroleum resin and coumarone resin. In particular,
When the adherend is a polyolefin, a rosin-based resin and a petroleum resin are preferable in that a strong adhesive force can be exhibited.

For the purpose of improving coating properties, thickeners such as acrylic rubber, epichlorohydrin rubber, isoprene rubber, butyl rubber, etc., thixotropic agents such as colloidal silica, polyvinylpyrrolidone, etc., and increasing amounts of calcium carbonate, titanium oxide, clay, etc. An agent may be added.

Further, for the purpose of imparting a high-strength shear adhesive force when the adhesive sheet is formed, an inorganic hollow body such as a glass balloon, an alumina balloon, or a ceramic balloon; or an organic hollow body such as a nylon bead, an acrylic bead, or a silicon bead. Spherical bodies; organic hollow bodies such as vinylidene chloride balloons and acrylic balloons; and single fibers such as glass, polyester, rayon, nylon and cellulose may be added.

When the above glass fibers are blended, it is possible to add a fibrous chip to the composition. High shear strength can be obtained.

The invention according to claim 2 In the invention according to claim 2, the polymerization initiator (D) comprises:
It is a photopolymerization initiator that initiates the polymerization of compounds (A) and (B) by irradiation with light. As such a photopolymerization initiator, a compound that is activated by irradiation with light and initiates polymerization is used. Although not particularly limited, one or more of the above-described photoradical polymerization initiators can be suitably used.

The polymerization initiator (E) is not particularly limited as long as it is a compound which is activated by irradiation with light to initiate ring-opening polymerization of an epoxy group. One or more of these can be suitably used, and an onium salt compound is preferably used.

Further, the onium salt compound is 370 n
m is activated by irradiation with light having a wavelength of less than m and is stable against heat, which is advantageous in improving the storage stability of the curable adhesive sheet before light irradiation, and the structure of the growth terminal is Since the reaction is more active at room temperature and there is no inactivation which is a termination reaction, the curing reaction after light irradiation and bonding can surely proceed at room temperature.

Specific examples of the onium salt compound include aromatic diazonium salts, aromatic iodonium salts, aromatic sulfonium salts, and pyridinium salts. More specifically, for example, Optomer SP-
150 (manufactured by Asahi Denka Kogyo), Optmer SP151 (manufactured by Asahi Denka Kogyo), Optmer SP171 (manufactured by Asahi Denka Kogyo), Optmer SP-170 (manufactured by Asahi Denka Kogyo), U
VE-1014 (manufactured by General Electronics), C
D-1012 (manufactured by Sartomer), Sun Aid SI-6
0L (manufactured by Sanshin Chemical Industry Co., Ltd.), Sun-Aid SL-80L
(Manufactured by Sanshin Chemical Industry Co., Ltd.), Sun-Aid SI-100L (manufactured by Sanshin Chemical Industry Co., Ltd.), CI-2064 (manufactured by Nippon Soda Co., Ltd.),
Commercially available compounds such as CI-2639 (Nippon Soda Co., Ltd.), CI-2624 (Nippon Soda Co., Ltd.), and CI-2481 (Nippon Soda Co., Ltd.) can be used.

The invention according to claim 3 In the invention according to claim 3, the polymerization initiator (D) comprises:
The polymerization initiator (E) is activated by irradiation with light having a wavelength of 370 nm or more and 800 nm or less.
It is activated by irradiation with light having a wavelength of not less than 00 nm and less than 370 nm. Therefore, by irradiating light having a wavelength of 370 to 800 nm, an adhesive polymer composed of a copolymer of the compound (A) and the compound (B) can be formed. By irradiating light having a wavelength, curing can be advanced by ring-opening polymerization of a compound having an epoxy group.

As the photopolymerization initiator (D) activated by irradiation with light having a wavelength of not less than 370 nm and not more than 800 nm, the above-mentioned photoradical polymerization initiator can be suitably used. As for the photopolymerization initiator (E) activated by irradiation with light having a wavelength of the above, the above-mentioned photopolymerization initiator, preferably, the above-mentioned onium salt compound can be suitably used.

The invention according to claim 4 The energy polymerizable composition according to the invention according to claim 4 is characterized in that the compound (A) and the compound (B) are a compound
The ratio of (A) to compound (B) is 10/3 by weight.
It is characterized by comprising a copolymer copolymerized so as to be in the range of 0 to 60/30, a compound (C) containing at least one epoxy group, and a polymerization initiator (E). That is, in the energy polymerizable composition according to the first aspect of the present invention, the energy polymerizable composition is obtained by previously copolymerizing the compound (A) with the compound (B) to form a copolymer. Corresponding composition.

In the energy polymerizable composition according to the fourth aspect of the present invention, since a copolymer comprising the above-mentioned copolymer has been produced, the polymerization initiator (E) is activated by applying energy. The compound (C) containing at least one epoxy group in one molecule can be cured by proceeding with ring-opening polymerization.

Examples of the copolymer of the compound (A) and the compound (B) include the compounds (A) and (B) described above.
It is not particularly limited as long as it consists of
Random copolymer, block copolymer, alternating copolymer,
Stereoregular copolymers, hyperbranched copolymers, star-shaped copolymers,
Any structure such as a dendritic copolymer, a ladder copolymer, a cyclic copolymer, and a helical copolymer can be used.

Further, the polymerization method for obtaining the above copolymer is not particularly limited, and an appropriate method such as a radical polymerization method, an anion polymerization method, a coordination polymerization method, or a photopolymerization method can be used.

The molecular weight of the above copolymer is not particularly limited, but is preferably large.
Those having a weight average molecular weight of about 200,000 to 5,000,000 are preferred. When the weight average molecular weight is 200,000 or less, the cohesive force of the sheet is insufficient, and stringing or sticking may occur at the time of sticking. When the weight average molecular weight exceeds 5,000,000, the viscosity of the composition containing the copolymer and the compound (C) having an epoxy group becomes high, and it may be impossible to form a sheet.

The curable adhesive according to the sixth aspect of the present invention.
The curable adhesive sheet according to the invention according to claim 6 is made of the energy polymerizable composition according to claim 4 or 5. In this case, as for the method of obtaining the curable adhesive sheet, after the energy polymerizable composition according to the first aspect of the present invention is formed into a sheet, energy is applied to activate the polymerization initiator (D). Compound (A)
And a compound (B). Alternatively, in the energy-polymerizable composition according to the first aspect, energy is applied to activate the polymerization initiator (D) to obtain a copolymer of the compound (A) and the compound (B). After that, the sheet may be molded to obtain a curable pressure-sensitive adhesive sheet.

In the latter case, the method for forming the sheet of the energy polymerizable composition according to the fourth aspect of the present invention is not particularly limited, and solvent coating, extrusion coating, calendering, or the like may be used as appropriate. Can be.

The solvent coating method is a method in which each component is dissolved in an organic solvent, coated on a substrate, and dried to form a sheet. In addition, the extrusion coating method and the calendering method have a weight average molecular weight of tens of thousands to 50 having a hot melt property.
This is a method in which a composition containing about 10,000 of the above-mentioned copolymer, a compound (C) having an epoxy group, and a polymerization initiator (E) is heated and melted, and is applied on a substrate using a melt coating apparatus. .

The method for forming the energy-polymerizable composition according to the first aspect of the present invention into a sheet can be similarly performed by using an appropriate method such as solvent coating, extrusion coating, or calendering. Further, after forming the sheet as described above, the polymerization initiator (D) is activated by applying energy to form a copolymer of the compound (A) and the compound (B) in the sheet. I just need.

In the case where the polymerization initiators (D) and (E) are constituted by a polymerization initiator which is activated by light irradiation, the energy can be easily applied by light irradiation. The process from the formation of the copolymer to the curing can be performed by a single means of irradiating light.

Further, as in the invention according to claim 3, the polymerization initiator (D) is 370 nm or more and 800 nm
The one which is activated by irradiating light of the following wavelengths is used. For the polymerization initiator (E), 300 nm or more,
In the case where a material activated by irradiation with light having a wavelength of less than 370 nm is used, the curing reaction can be surely progressed after the copolymer is formed by changing the wavelength of the light to be irradiated. .

When a photopolymerization initiator is used as the polymerization initiator (D), if light having a wavelength exceeding 800 nm is used, the performance of the curable adhesive sheet may be deteriorated by radiant heat. Equipment such as a cut filter may be required, and other heat removal equipment may be required.

When the polymerization initiator (E) is used as a photopolymerization initiator, when light having a wavelength of less than 300 nm is used, there is little light transmission power, only the surface is cured, and the curable adhesive is used. The adhesion of the adhered sheet to the adherend on the adhered surface may decrease, or the interior of the curable adhesive sheet may remain uncured.

Adhesive Member The curable adhesive sheet according to the present invention is used as it is in the form of a double-sided pressure-sensitive adhesive tape so as to be interposed between bonding members to be adhered to an adherend. Alternatively, the adhesive may be formed as an adhesive layer on at least one surface of a substrate and configured as an adhesive member with the substrate.

Examples of the substrate include various nonwoven fabrics such as rayon or cellulose, films or sheets made of various synthetic resins such as polyethylene, polyester, cellophane, polypropylene, polystyrene, and polyimide; foamed polyethylene, urethane foam, and neoprene foam. , Foamed vinyl chloride, foamed polystyrene and other foams, polystyrene, ABS, acrylic, polypropylene, polyethylene and other synthetic resins, resin plates,
Sheets or plates made of various metals such as steel, stainless steel, copper, and aluminum, glass, wood, paper, cloth, tiles, gypsum boards, light culverts, and the like can be used without any particular limitation. Further, the shape of the substrate is not limited to a thin shape such as a sheet or a plate, and may be any shape such as a prism, a rod, a sphere, and a shape having an aspheric surface.

Member joining method The member joining using the curable adhesive sheet according to the present invention is performed.
In the bonding method, when bonding the bonding member to the adherend via the curable adhesive sheet, that is, before bonding,
Alternatively, light irradiation is performed after the bonding to cure the curable adhesive sheet. In this case, preferably, “before bonding” means before bonding and before curing of the resin having an epoxy group is completed by light irradiation . When the curing of the compound having an epoxy group is completed by light irradiation , the curable pressure-sensitive adhesive sheet becomes too hard, and a sufficient initial adhesive strength may not be obtained.

Before the joining member is joined to the adherend, when light is irradiated as activation energy to cure the curable adhesive sheet, the light is applied to the joining member or the adherend. Is not irradiated, it is possible to prevent deterioration of the bonding member and the adherend due to light. Therefore, when joining an adherend or a joining member that is likely to be deteriorated by light irradiation, it is desirable to irradiate the curable adhesive sheet in advance with light as described above. Further, when one of the adherend and the bonding member is easily deteriorated by light and the other is hardly deteriorated by light,
A curable pressure-sensitive adhesive sheet may be attached to the other member side, irradiated with light, and then attached to the one member.

When the photosensitive onium salt compound is used as a photo-cationic polymerization initiator, the wavelength of light irradiated upon curing is light in a wavelength region of 300 nm or more, and the intensity is 1 mW / cm ^2. ~ 100mW / cm
It is preferred to use less than ^two lights. Wavelength is 300nm
If less than the above, sufficient energy to activate the photosensitive onium salt compound can be obtained, but there is not much light transmission power, only the adhesive surface is cured, and the bonding surface of the curable adhesive sheet is cured. Adhesion to the adherend may be reduced. Further, the inside of the curable adhesive sheet may remain uncured.

The intensity of light in the wavelength region of 300 nm or more is
In the case of less than 1 mW / cm ² , the energy is not enough to activate the photosensitive onium salt compound, and only a small amount of the onium salt compound is exposed to light, so that the curing speed becomes extremely slow. Therefore, preferably, 300 nm or more, more preferably 300 nm or more, less than 800 nm,
More preferably, light in a wavelength region of 300 nm or more and less than 400 nm is used.

When the intensity of the light irradiated during the above-mentioned curing exceeds 100 mW / cm ² , the radiation heat due to the light cannot be ignored, and the curing reaction due to the heat is accelerated. , Immediately surface hardening occurs. That is, the adhesiveness of the curable adhesive sheet to the adherend may hardly be seen.

[0090] In the energy polymerizable composition according to the invention described in the action claim 1, a compound having at least one (meth) acryloyl group and at least one hydroxyl group in the molecule (A)
And a compound (B) having a copolymerizable unsaturated bond with the compound (B).
The ratio is in the range of 10/30 to 60/30 by weight,
Copolymers of the polymerization initiator by light irradiation (D) is activated by compounds (A) and (B) and is Ru is generated. Since this <br/> copolymer which in a normal state has adhesion, the energy polymerizable composition according to the present invention can be suitably used as an adhesive or a curable pressure-sensitive adhesive sheet. Further, the composition contains the compound (C) having an epoxy group and the polymerization initiator (E), and the polymerization initiator (E) is activated by light irradiation, whereby the compound (C) having an epoxy group is ring-opened. Polymerizes and cures. Therefore, it is possible to give an adhesive cured product having high adhesive strength by light irradiation . In particular, in the invention described in claim 1, the compound (A) having the at least one (meth) acryloyl group and at least one hydroxyl group and the compound (B) having an unsaturated bond copolymerizable therewith are provided. , The curing proceeds quickly,
Therefore, it is possible to shorten the time from the light irradiation to the time when the final adhesive strength is obtained. Therefore, the curing time after light irradiation can be shortened.

When the polymerization initiators (D) and (E) are activated by light irradiation, respectively, as in the second aspect of the invention, First, an adhesive polymer comprising a copolymer of the compound (A) and the compound (B) can be produced, and in that state, it can be easily applied to an adherend. In addition, the ring-opening polymerization of the compound (C) having an epoxy group proceeds by further irradiating light before or after attaching to the adherend, and a strong adhesive cured product is obtained. Therefore, since it can be cured by light irradiation, it can be applied to an adherend having difficulty in heat resistance.

According to the third aspect of the present invention, the polymerization initiator (D) is activated by irradiation with light having a wavelength of 370 nm or more and 800 nm or less. A) and the compound (B) can form a copolymer, while the polymerization initiator (E) is activated by light having a wavelength of 300 nm or more and less than 370 nm. By doing so, curing can be advanced. That is, since the wavelengths of light for activating the polymerization initiators (D) and (E) are different as described above, first, only the copolymerization of the compound (A) and the compound (B) is caused to occur. After the copolymer is obtained, by irradiating light having the above specific wavelength, the curing reaction can be surely progressed by ring-opening polymerization of the compound having an epoxy group.

When light having a wavelength of less than 300 nm is used for curing, curing may not sufficiently proceed to the inside, whereas in the invention according to claim 3, light having a wavelength of 300 nm or more is used. Because of the use, curing proceeds reliably to the inside.

In the invention described in claim 4, the copolymer of the compound (A) and the compound (B), the compound (C) having an epoxy group, and the polymerization initiator (E) are a compound
The ratio of (A) to compound (B) is 10/3 by weight.
Copolymerized so as to be in the range of 0 to 60/30
Since it contains a polymer, the energy polymerizable composition can be easily cured by irradiating the energy polymerizable composition with light for activating the polymerization initiator (E). Therefore, when used as adhesive or curable pressure-sensitive adhesive sheet In example embodiment, it can be suitably used to an adherend with a difficulty in heat resistance. Moreover, similarly to the case of the adhesive or the curable adhesive sheet using the energy-polymerizable composition according to the invention of claim 1, curing from irradiation of light to development of the final adhesive strength. Since the time can be shortened and the adhesive has tackiness under normal conditions, severe conditions such as pressing under high temperature and high pressure are not required.

In the case where the polymerization initiator (E) is activated by light having a wavelength of 300 nm or more and less than 370 nm, the curing proceeds to the inside without fail, and Strength is sufficiently increased.

The curable pressure-sensitive adhesive sheet according to the sixth aspect of the invention is composed of the energy polymerizable composition according to the fourth or fifth aspect of the present invention, and thus is easily applied to an adherend in a normal state. The compound (C) having an epoxy group undergoes ring-opening polymerization and cures by irradiation with light, thereby providing a strong adhesive cured product.
In addition, since it can be attached to an adherend using the above-mentioned adhesiveness, harsh conditions such as pressing under high temperature and high pressure are not required for joining. Furthermore, in the invention according to claim 4, since the copolymer of the specific compound (A) and the compound (B) is used, the curing time until the final adhesion strength is exhibited after energy application. Shortening can be achieved.

[0097]

[0098]

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

Example 1 In a 2 L separable flask, compound 2 (product name: Plaxel FM-2D, n = 2, manufactured by Daicel Chemical Industries Ltd.) as compound (A) 50 was used.
g, glycidyl methacrylate 150 g, and an epoxy resin (trade name: Epicoat 8 manufactured by Yuka Shell Epoxy Co., Ltd.)
28) 300 g, 150 g of an epoxy resin (trade name: Rikaresin BEO-60E, manufactured by Nippon Rika Co., Ltd.), and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentyl phos as a photoradical polymerization initiator 0.5 g of fin oxide (trade name: Irgacure 1700, manufactured by Ciba Geigy) and 2.5 g of photocationic polymerization initiator (trade name: Optmer SP-170, manufactured by Asahi Denka Kogyo Co., Ltd.)
Was stirred and mixed until uniform, and then dissolved oxygen was removed by bubbling with nitrogen gas for 20 minutes to obtain a photopolymerizable composition.

The above photopolymerizable composition was applied to a polyethylene terephthalate film whose surface was subjected to a release treatment to a thickness of 0.1 μm.
The film was coated so as to have a thickness of 3 mm, and another surface of the coated film of the photopolymerizable composition was coated with a polyethylene terephthalate film having a release treatment. Thus, a laminate in which the coating film made of the photopolymerizable composition was sandwiched between the pair of polyethylene terephthalate films was obtained.

Using a fluorescent lamp having a maximum emission wavelength at 400 nm, near-ultraviolet light substantially not containing light in a wavelength region of 360 nm or less, and a light intensity of 1 mW / c.
as a m ^2, and irradiated for 10 minutes to obtain a cured pressure-sensitive adhesive sheet.

(Examples 2 to 19 and Comparative Examples 1 to 8) The compositions of the photopolymerizable compositions used to obtain the curable adhesive sheets were changed as shown in Tables 1 to 4 below. Except for this, a curable adhesive sheet was produced in the same manner as in Example 1.

(Evaluation) Evaluation of Shear Adhesive Strength The laminate obtained as described above was cut into a size of 25 mm × 25 mm, and polished with water-resistant abrasive paper # 280.
The surface was degreased and dried with ethyl acetate, width 30 mm, length 1
50mm, 2mm thick stainless steel plate (SUS304,
Hereinafter, the adherend A is abbreviated. ). Next, 300n
The light intensity is 30 mW / cm ^{2 in} the wavelength range from m to 370 nm.
The cured light-sensitive adhesive sheet was irradiated with light for 30 seconds. Immediately after the light irradiation, the polyethylene terephthalate film coated on the back surface of the curable adhesive sheet is immediately peeled off, and the adherend B prepared in the same manner as the adherend A is bonded and sheared. A force specimen was obtained. Using this shear adhesion test piece, after curing for 7 days after bonding, the shear adhesion was measured according to JIS K 6850. The results are shown in Tables 1 to 4 below.

Evaluation of Curing Completion Time A shear adhesion test piece was obtained in the same manner as in the above-mentioned shear adhesion evaluation, and after the shear adhesion test piece was obtained, the crosshead was measured every predetermined time according to JIS K 6850. The shear adhesion was measured at a speed of 10 mm / min, and the measured value (kgf)
Was divided by the adhesive area to obtain the shear adhesive force per unit area, and the time when the shear adhesive force per unit area almost reached a saturation value was defined as the curing completion time.

[0105]

[Table 1]

[0106]

[Table 2]

[0107]

[Table 3]

[0108]

[Table 4]

[0109]

[Table 5]

[0110]

The energy-polymerizable composition according to the first aspect of the present invention has at least one (meth) compound per molecule.
Compound (A) having an acryloyl group and at least one hydroxyl group, and compound (B) having an unsaturated bond copolymerizable with compound (A) are compound (A)
The ratio with respect to (B) is 10/30 to 60/30 by weight.
Included in such a range, a compound having an epoxy group (C), and a polymerization initiator and (D), for further comprising a polymerization initiator (E), polymerization initiator (D) activity When the energy polymerizable composition according to the invention according to claim 4 having a copolymer of the compound (A) and the compound (B) by being converted to It can be easily applied to the body without requiring severe bonding conditions. In addition, by irradiating the polymerization initiator (E) with light prior to or after application, the compound (C) undergoes ring-opening polymerization and cure proceeds. Therefore, the adherends can be firmly bonded to each other.

In addition, since a copolymer of the specific compound (A) and the compound (B) having an unsaturated bond is used, energy is applied to activate the polymerization initiator (E). Even if the curing is advanced, the cohesive force is unlikely to decrease, so that the adhesive or the curable adhesive sheet formed using the energy-polymerizable composition according to the invention according to claim 1 requires energy. The pot life from the application of the material to the application can be made sufficiently long. In addition, since it contains the specific copolymer, the compound (C) having an epoxy group, and the polymerization initiator (E), the curing completion time until curing reaches the final adhesive strength, that is, the curing time Can be shortened.

Therefore, it is possible to stably provide a curable adhesive or a curable adhesive sheet having an excellent balance between the pot life and the curing time until the curing is completed.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08G 59/40-59/66 C09J 7/00 C09J 163/00-163/10 C08F 2/48-2 / 50 C09J 5/00

Claims (6)

(57) [Claims] An energy for obtaining a post-curable adhesive.
-A polymerizable composition, (A) a compound having at least one (meth) acryloyl group and at least one hydroxyl group in one molecule, and (B) an unsaturated bond copolymerizable with the compound (A). With respect to compound (B) of compound (A)
Ratio is in the range of 10 / 30-60 / 30 by weight, of (C) at least a compound of one containing an epoxy group and, (D) compound by light irradiation in one molecule (A) and (B) An energy-polymerizable composition, further comprising: a polymerization initiator for initiating polymerization; and (E) a polymerization initiator for initiating ring-opening polymerization of an epoxy group of compound (C) by light irradiation . 2. The polymerization initiator (D) is a polymerization initiator for initiating polymerization of the compounds (A) and (B) by light irradiation, and the polymerization initiator (E) is a compound The energy polymerizable composition according to claim 1, which is a polymerization initiator that initiates ring-opening polymerization of the epoxy group (C). 3. The polymerization initiator (D) is activated by irradiating light with a wavelength of 370 nm or more and 800 nm or less, and the polymerization initiator (E) is 300 nm or more.
The energy polymerizable composition according to claim 2, which is activated by irradiation with light having a wavelength of less than 370 nm. 4. A compound (A) having at least one (meth) acryloyl group and at least one hydroxyl group in one molecule, and a compound (B) having an unsaturated bond copolymerizable with the compound (A). Is the compound (B) of the compound (A)
Is in the range of 10/30 to 60/30 by weight.
And become so copolymerized with styrenesulfonate, at least an epoxy group one containing compound (C), polymerization is initiated ring-opening polymerization of the epoxy group of the compound (C) by light irradiation in one molecule An energy polymerizable composition comprising an initiator (E). 5. The energy polymerizable composition according to claim 4, wherein the polymerization initiator (E) is activated by irradiating light having a wavelength of 300 nm or more and less than 370 nm. 6. A curable adhesive sheet comprising the energy-polymerizable composition according to claim 4 or 5.