JP2011236297A - Method for producing cured product, cured product, sealing material for electronic component, and gasket material for electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for well productively producing a cured product having a low moisture permeability, a high weatherability and generates little outgas while maintaining the cured product at a desired hardness (for example, ≤55°); to provide a cured product obtained by the production method; and to provide a sealing material for an electronic component composed of the cured product, and a gasket material for an electronic component composed of the cured product.SOLUTION: The production method of a cured product includes: mixing 0.01 to 5 pts.mass of (3) a radical photoinitiator and 0.1 to 10 pts.mass of (4) a radical thermopolymerization initiator based on 100 pts.mass of the total of 90 to 30 mass% of (1) a liquid resin obtained by reacting a hydrogenated or nonhydrogenated conjugate dienic polymer polyol or a hydrogenated or nonhydrogenated conjugate diene-aromatic vinylic copolymer polyol with an unsaturated hydrocarbon group-containing compound, and 10 to 70 mass% of (2) a monofunctional or bifunctional (meth)acrylate; and irradiating the mixture with an active energy ray.

Description

  The present invention is a liquid obtained by reacting a hydrogenated or non-hydrogenated conjugated diene polymer polyol or a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol with an unsaturated hydrocarbon group-containing compound. The present invention relates to a method for producing a cured product using a resin, a cured product obtained by the production method, an electronic component sealing material comprising the cured product, and an electronic component gasket material comprising the cured product.

In recent years, various photocurable resins have been developed for sealing materials and adhesives.
For example, Patent Document 1 discloses a polyether polyol-based photocurable resin for surface processing of woodwork products such as woodworking plywood, furniture, and musical instruments. However, since polyether polyol has high hydrophilicity and high water vapor permeability, it is unsuitable for use in sealing materials and gasket materials that require water vapor barrier properties.
Patent Document 2 discloses a polyester polyol-based photocurable resin composition for wood coatings. However, polyester polyols are not suitable for use in sealing materials and gasket materials that are exposed to high-temperature and high-humidity environments because the polyester main chain undergoes hydrolysis and degradation under high-temperature and high-humidity environments.
A polybutadiene-based photocurable resin composition is known as one that improves the water vapor permeability and durability to high-temperature and high-humidity environments. For example, Patent Document 3 discloses that a hydroxyl group of a polymer having a polymer chain obtained by polymerizing butadiene with a 1,2-bond or a hydrogenated polymer chain and having a hydroxyl group in the molecule is acryloyl. An adhesive for optical instruments and precision machines using liquid polybutadiene (meth) acrylate modified with a polymerizable functional group such as a group or a methacryloyl group is disclosed. However, these have a low molecular weight as a 1,2-bond or hydrogenated polybutadiene-based photocurable resin, so that the molecular weight between cross-linking points is small and high cross-linking results in hindering rubber elasticity. Since it has a high elastic modulus, no elongation, low tensile strength, and poor fatigue, it was not practical due to cracking when used as a gasket, packing, sealing material, or the like.
Therefore, hydrogenated conjugated diene-based (co) polymer photocuring that can control the molecular weight and molecular weight distribution to increase the molecular weight, has excellent photocurability, and greatly improves the physical properties after curing described above. Liquid resin has been developed (see Patent Document 5).

JP-A-5-202163 JP 2000-219714 A JP 2002-371101 A Japanese Patent Publication No. 1-53681 JP 2007-145949 A

The composition containing the photocurable liquid resin described in Patent Document 5 has low hardness and good heat resistance. However, since the photocurable resin composition usually tends to generate unreacted components and low molecular components in the photocurable liquid resin as outgas, it is necessary to sufficiently bake to reduce the outgas. There are problems that the hardness of the cured product is increased and that it is difficult to increase productivity.
The present invention has been made under such circumstances, and the cured product has low moisture permeability, high weather resistance, and low outgas, while maintaining the cured product at a desired hardness (for example, 55 degrees or less). It is an object of the present invention to provide a method for producing a product with high productivity, a cured product obtained by the production method, a sealing material for electronic parts comprising the cured product, and a gasket material for electronic parts comprising the cured product. It is.

  As a result of intensive studies in order to solve the above problems, the present inventors have reacted a specific liquid resin, a specific monomer, a photo radical polymerization initiator, and a specific heat radical polymerization initiator at a specific ratio. The present inventors have found that a cured product having low moisture permeability, high weather resistance, and low outgas can be produced with high productivity while maintaining the cured product at a desired hardness (for example, 55 degrees or less). The present invention has been completed based on such findings.

That is, the present invention relates to the following [1] to [8].
[1] At least (1) a hydrogenated or non-hydrogenated conjugated diene polymer polyol or a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol is reacted with an unsaturated hydrocarbon group-containing compound. (3) radical photopolymerization initiator 0.01-5 with respect to a total of 100 parts by weight of 90-30% by weight of the liquid resin obtained and 10-70% by weight of (2) monofunctional or bifunctional (meth) acrylate. The manufacturing method of hardened | cured material by mixing a mass part and (4) 0.1-10 mass parts of thermal radical polymerization initiators, and making it react by irradiating an active energy ray.
[2] Hydrogenated or non-hydrogenated conjugated diene polymer polyol or hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol is produced by the following steps (A) to (B) or (A) to ( The method for producing a cured product according to [1], which is produced by C).
(A) Polymerization of a conjugated diene monomer or copolymerization of a conjugated diene monomer and an aromatic vinyl monomer with a dilithium initiator in a saturated hydrocarbon solvent, and a weight average molecular weight The process of manufacturing the conjugated diene type polymer or conjugated diene-aromatic vinyl type copolymer which has 5,000-40,000 and molecular weight distribution 3.0 or less.
(B) The conjugated diene polymer or conjugated diene-aromatic vinyl copolymer is reacted with an alkylene oxide to produce a conjugated diene polymer polyol or a conjugated diene-aromatic vinyl copolymer polyol. Process.
(C) Hydrogenation reaction of the conjugated diene polymer polyol or conjugated diene-aromatic vinyl copolymer polyol, and hydrogenated conjugated diene polymer polyol or hydrogenated conjugated diene-aromatic vinyl copolymer polyol Manufacturing process.
[3] The method for producing a cured product according to the above [2], wherein the aromatic vinyl monomer is at least one selected from styrene, α-methylstyrene, and paramethylstyrene.
[4] The method for producing a cured product according to any one of [1] to [3], wherein the unsaturated hydrocarbon group of the unsaturated hydrocarbon group-containing compound is a (meth) acryloyl group.
[5] The thermal radical polymerization initiator is a ketone peroxide polymerization initiator, a hydroperoxide polymerization initiator, a dialkyl peroxide polymerization initiator, a peroxyketal polymerization initiator, or a peroxyester polymerization initiator. The method for producing a cured product according to any one of the above [1] to [4], which is at least one selected from the group consisting of a peroxydicarbonate polymerization initiator and a diacyl peroxide polymerization initiator.
[6] A cured product obtained by the production method according to any one of [1] to [5].
[7] A sealing material for electronic parts comprising the cured product according to [6].
[8] A gasket material for electronic parts comprising the cured product according to [6].

  According to the present invention, there is provided a method for producing a cured product having low moisture permeability, high weather resistance, and low outgassing with high productivity while maintaining the cured product at a desired hardness (for example, 55 degrees or less). Can be provided.

[Method for producing cured product]
The present invention at least (1) reacts a hydrogenated or non-hydrogenated conjugated diene polymer polyol or a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol with an unsaturated hydrocarbon group-containing compound. The total amount of liquid resin 90 to 30% by mass and (2) monofunctional or bifunctional (meth) acrylate 10 to 70% by mass with respect to 100 parts by mass of (3) photoradical polymerization initiator 0.01 to 5 mass parts and (4) 0.1-10 mass parts of thermal radical polymerization initiators are mixed, and it is a manufacturing method of hardened | cured material by irradiating an active energy ray and making it react.
Hereinafter, components (1) to (4) will be described in order.

((1) Liquid resin)
Component (1) is obtained by reacting a hydrogenated or non-hydrogenated conjugated diene polymer polyol or a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol with an unsaturated hydrocarbon group-containing compound. Liquid resin. The liquid resin can be cured by light or heat.
Such hydrogenated or non-hydrogenated conjugated diene polymer polyol or hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol is prepared by the following steps (A) to (B) or (A) to (C). It is preferable to manufacture by.
(A) Polymerization of a conjugated diene monomer or copolymerization of a conjugated diene monomer and an aromatic vinyl monomer with a dilithium initiator in a saturated hydrocarbon solvent, and a weight average molecular weight The process of manufacturing the conjugated diene type polymer or conjugated diene-aromatic vinyl type copolymer which has 5,000-40,000 and molecular weight distribution 3.0 or less.
(B) The conjugated diene polymer or conjugated diene-aromatic vinyl copolymer is reacted with an alkylene oxide to produce a conjugated diene polymer polyol or a conjugated diene-aromatic vinyl copolymer polyol. Process.
(C) Hydrogenation reaction of the conjugated diene polymer polyol or conjugated diene-aromatic vinyl copolymer polyol, and hydrogenated conjugated diene polymer polyol or hydrogenated conjugated diene-aromatic vinyl copolymer polyol Manufacturing process.

Since the reaction in the step (A) is living anionic polymerization, it can be polymerized by controlling the molecular weight and molecular weight distribution. The molecular weight can be obtained by polymerizing a polymer having a predetermined molecular weight depending on the amount of the dilithium initiator and the above monomer. In particular, when the weight average molecular weight is 5,000 or more, a narrow polymer having a molecular weight distribution of 2 or less is used. Easy to get. If desired, anionic polymerization may be carried out in the presence of a randomizer.
Next, as the step (B), the conjugate of the (co) polymer obtained in the above step (A) is reacted with a polymer end, which is a living anion, and an alkylene oxide in an equivalent amount, thereby having a hydroxyl group at both ends. A diene polymer polyol or a conjugated diene-aromatic vinyl copolymer polyol (hereinafter may be collectively referred to as a (co) polymer polyol) can be obtained.
Furthermore, as a step (C), a hydrogenation reaction (hereinafter referred to as a hydrogenation reaction) is performed on the (co) polymer polyol obtained in the step (B) having a double bond in the main chain, thereby providing a hydrogenated conjugate. A diene polymer polyol or a hydrogenated conjugated diene-aromatic vinyl copolymer polyol (hereinafter sometimes referred to as a hydrogenated (co) polymer polyol) may be obtained.

Examples of the conjugated diene monomer that can be used in the step (A) include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene and the like can be mentioned. These may be used alone or in combination of two or more. Among these, 1,3-butadiene is preferable from the viewpoint of securing rubber elasticity which is preferably possessed after curing.
The aromatic vinyl monomer is preferably styrene, α-methylstyrene or paramethylstyrene from the viewpoint of rubber physical properties after curing. One aromatic vinyl monomer may be used alone, or two or more aromatic vinyl monomers may be used in combination.

It does not specifically limit as a dilithium initiator used at the said process (A), A well-known thing can be used. For example, in Patent Document 4 (Japanese Patent Publication No. 1-53681), a monolithium compound is mixed with a disubstituted vinyl or alkenyl group-containing aromatic hydrocarbon (for example, 1,3- (diiso) in the presence of a tertiary amine. A method for producing dilithium initiators by reaction with propenyl) benzene etc. is described.
Monolithium compounds used when producing a dilithium initiator include ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-butyl lithium, tert-octyl lithium, and n-decyl lithium. Phenyl lithium, 2-naphthyl lithium, 2-butylphenyl lithium, 4-phenylbutyl lithium, cyclohexyl lithium, cyclopentyl lithium and the like. Among these, sec-butyl lithium is preferable.

Examples of the tertiary amine used when producing the dilithium initiator include lower aliphatic amines such as trimethylamine and triethylamine, N, N-diphenylmethylamine, and the like. Among these, triethylamine is preferable.
Examples of the disubstituted vinyl or alkenyl group-containing aromatic hydrocarbon include 1,3- (diisopropenyl) benzene, 1,4- (diisopropenyl) benzene, and 1,3-bis (1-ethylethenyl). ) Benzene, 1,4-bis (1-ethylethenyl) benzene and the like are preferred.

  The solvent used in the preparation of the dilithium initiator and the production of the (co) polymer may be any organic solvent inert to the reaction, and may be a hydrocarbon system such as an aliphatic, alicyclic, or aromatic hydrocarbon compound. A solvent is used. In addition, about this solvent, patent document 5 (Unexamined-Japanese-Patent No. 2007-145949) can be referred.

  Moreover, as an alkylene oxide used at a process (B), ethylene oxide, a propylene oxide, or a butylene oxide etc. are mentioned, for example. This polyol reaction (step (B)) is preferably carried out immediately after the polymerization reaction (step (A)).

If the weight average molecular weight of the (co) polymer polyol obtained in the step (B) is 5,000 or more, the molecular weight between the crosslinking points can be increased, and after the photocuring reaction, the elastic modulus is lowered and the elongation ( Since Eb) can be increased, it is preferable. On the other hand, if the (co) polymer polyol having a weight average molecular weight of 40,000 or less is produced, the polymerization viscosity does not become too high when the polymerization is performed with the dilithium catalyst in the step (A). Since it is not necessary to lower the solid content concentration as a polymerization process, the cost is preferable. As for the weight average molecular weight of the (co) polymer polyol obtained by the process (B), 5,000-30,000 are more preferable.
Moreover, if molecular weight distribution is 3.0 or less, the various influence by a low molecular weight component and a high molecular weight component can be suppressed. In particular, since the viscosity is greatly affected by the molecular weight, the fluctuation of the molecular weight causes a viscosity variation. If it is the said method, since the (co) polymer of narrow molecular weight distribution can be synthesize | combined, the (co) polymer of the same molecular weight can be obtained with good reproducibility, and the effect of stabilizing a viscosity can be expected.
The liquid material (liquid resin) used in the present invention is often dispensed by a dispenser. In this case, variation in material viscosity results in variation in dimensions after coating, so viscosity stabilization is important. The molecular weight distribution is preferably 3.0 or less, more preferably 2.0 or less.

The hydrogenation reaction in step (C) is carried out by hydrogenating the (co) polymer polyol obtained in step (B) in an organic solvent under hydrogen pressure and in the presence of a hydrogenation catalyst.
The hydrogenation catalyst used in the method of the present invention is a heterogeneous catalyst such as palladium-carbon, reduced nickel, rhodium, or the like, or an organic nickel compound such as nickel naphthenate or nickel octoate, or an organic cobalt such as cobalt naphthenate or cobalt octoate. A homogeneous catalyst in which the compound is combined with an organoaluminum compound such as triethylaluminum or triisobutylaluminum or an organolithium compound such as n-butyllithium or sec-butyllithium can be used. As a cocatalyst, for example, an ether compound such as tetrahydrofuran, ethylene glycol dimethyl ether, or diethylene glycol dimethyl ether may be used.
As another hydrogenation reaction method, for example, the (co) polymer polyol before hydrogenation is mixed with dicyclopentadienyl titanium halide, organic carboxylate nickel, organic carboxylate nickel and periodic tables I to III. 1 catalyst using a hydrogenation catalyst comprising a group III organometallic compound, nickel, platinum, barium, ruthenium, rhenium, rhodium metal catalyst or cobalt, nickel, rhodium, ruthenium complex, etc. supported on carbon, silica, diatomaceous earth, etc. Under hydrogen pressurized to -100 atm, or in the presence of lithium aluminum hydride, p-toluenesulfonyl hydrazide, Zr-Ti-Fe-V-Cr alloy, Zr-Ti-Nb-Fe-V-Cr alloy, the presence of the hydrogen storage alloy such as LaNi ₅ alloy, or with pressurized under hydrogen in 1 to 100 atm, And a hydrogenation catalyst obtained by mixing a cyclohexane solution of di-p-tolyl-bis (1-cyclopentadienyl) titanium and an n-hexane solution of n-butyllithium under hydrogen. Examples of the method include hydrogenation under hydrogen pressurized to 1 to 100 atm.

Among the various hydrogenation catalysts described above, a Ziegler hydrogenation catalyst or a palladium-carbon hydrogenation catalyst comprising a combination of a transition metal compound and an alkylaluminum compound is preferred.
Such transition metal compounds include tris (acetylacetonato) cobalt, bis (acetylacetonato) nickel, tris (acetylacetonato) iron, tris (acetylacetonato) chromium, tris (acetylacetonato) manganese, bis (acetyl). Acetonato) manganese, tris (acetylacetonato) ruthenium, bis (acetylacetonato) cobalt, bis (cyclopentadienyl) dichlorotitanium, bis (cyclopentadienyl) dichlorozirconium, bis (triphenylphosphine) cobalt dichloride, Examples thereof include bis (2-hexanoate) nickel, bis (2-hexanoate) cobalt, titanium tetraisopropoxide, and titanium tetraethoxide. Among these, bis (acetylacetonato) nickel and tris (acetylacetonato) cobalt are preferable from the viewpoint of hydrogenation activity.
Examples of the alkylaluminum compound used in the Ziegler hydrogenation catalyst include trimethylaluminum, triethylaluminum, triisopropylaluminum, triisobutylaluminum, tri-n-butylaluminum, dimethylaluminum chloride, diethylaluminum chloride, diisobutylaluminum chloride, methylaluminum dichloride. , Ethylaluminum dichloride, isobutylaluminum dichloride, diethylaluminum hydride, diisobutylaluminum hydride, ethylaluminum sesquichloride. Among these, from the viewpoint of hydrogenation activity, triisobutylaluminum, triethylaluminum, and diisobutylaluminum hydride are preferable, and triisobutylaluminum is more preferable.

  Although there is no restriction | limiting in particular in the usage form of a Ziegler type | system | group hydrogenation catalyst, The method of preparing the catalyst solution which made the transition metal compound and the alkyl aluminum compound react previously and adding it to a polymerization solution can be mentioned preferably. The amount of the alkylaluminum compound used in this case is preferably 0.2 to 5 mol with respect to 1 mol of the transition metal compound. The reaction for preparing the catalyst is carried out in the temperature range of −40 to 100 ° C., preferably 0 to 80 ° C., and the reaction time is in the range of 1 minute to 3 hours.

  Moreover, the temperature of the hydrogenation reaction in the step (C) is usually preferably 50 to 180 ° C, more preferably 70 to 150 ° C. The hydrogenation reaction is preferably carried out at a hydrogen pressure of 5 to 100 atmospheres (5,06.25 to 101,325 hPa), more preferably 10 to 50 atmospheres (10132.5 to 50,662.5 hPa). Is called. If the reaction temperature and the hydrogen pressure are in this range, the catalyst activity can be maintained high, and the catalyst is hardly deactivated or side reaction is preferable.

The hydrogenated (co) polymer polyol obtained as described above is reacted with an unsaturated hydrocarbon group-containing compound to introduce an unsaturated hydrocarbon group at the terminal of the hydrogenated (co) polymer polyol.
As the unsaturated hydrocarbon group, a (meth) acryloyl group is preferable. As the unsaturated hydrocarbon group-containing compound, (meth) acryloyl isocyanate is preferable, and the hydrogenated (co) polymer polyol is (meth) acrylated by reaction with them.
Examples of (meth) acryloyl isocyanate include 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate.

  The liquid resin obtained as described above is mixed with (2) isobornyl (meth) acrylate, (3) a photoradical polymerization initiator, and (4) a diperoxide compound as a thermal radical polymerization initiator. And reacting with active energy rays such as electron beam.

((2) Monofunctional or bifunctional (meth) acrylate)
The monofunctional or bifunctional (meth) acrylate monomer preferably has a molecular weight of less than 1,000, more preferably 150 to 600.
Examples of the monofunctional (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and t-butyl (meth). Acrylate, isoamyl (meth) acrylate, isobornyl (meth) acrylate, isobutyl (meth) acrylate, isodecyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate , Isomyristyl (meth) acrylate, benzyl (meth) acrylate, lauroxypolyethylene glycol (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) Acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, phenoxyethyl (meth) acrylate, Dicyclopentenyloxyethyl (meth) acrylate, diethylene glycol monoethyl ether (meth) acrylate, dimethylaminoethyl (meth) acrylate, dipropylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, ethoxylated phenyl (meth) acrylate, Methoxydipropylene glycol (meth) acrylate, methoxytripylene glycol (meth) acrylate, methoxypolyethyleneglycol (Meth) acrylate, methoxytriethylene glycol acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, nonylphenoxypolypropylene glycol (meth) acrylate, nonylphenoxypolyethyleneglycol-polypropyleneglycol (meth) acrylate, nonylphenoxypolypropyleneglycol-polyethyleneglycol (meta ) Acrylate and the like. These may be used individually by 1 type and may use 2 or more types together. As the monofunctional (meth) acrylate monomer, isobornyl methacrylate, dicyclopentanyl acrylate, and dicyclopentenyl acrylate are preferable.

Bifunctional (meth) acrylate monomers include 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, 1,10-decanediol diacrylate, tricyclodecane dimethanol diacrylate, and dimethylol diester. And cyclopentane di (meth) acrylate.
Monofunctional or bifunctional (meth) acrylates not only reduce the viscosity of the photocurable composition before curing, but also improve the physical properties after curing. That is, it is possible to improve the adhesive strength, decrease the hardness, improve Eb (elongation), and Tb (breaking strength). For this reason, monofunctional or bifunctional (meth) acrylate is essential instead of trifunctional or higher functional (meth) acrylate, but the use of trifunctional or higher functional (meth) acrylate is not denied. In addition, when using together the trifunctional or more than trifunctional (meth) acrylate, the compounding quantity becomes like this. Preferably it is 15 mass% or less with respect to the whole quantity of (meth) acrylate, More preferably, it is 5 mass% or less, More preferably, it is 2 mass % Or less.
The compounding quantity of monofunctional or bifunctional (meth) acrylate is 10-70 mass% with respect to the sum total of a component (1) and (2), Preferably it is 10-60 mass%, More preferably, it is 20-40 mass. %. If it is 10 mass% or more, the viscosity reduction effect can be enjoyed when all components are mixed and reacted, and extrusion, discharge, etc. are facilitated, and it becomes easy to form a sealing material or the like. Moreover, if it is 60 mass% or less, when all components are mixed and made to react, a viscosity will not become low too much and it will become difficult to flow down the sealing material etc. immediately after formation. Furthermore, since the adhesive strength and elasticity of the cured sealing material and the like are ensured, the airtightness is not easily lost.

((3) Photoradical polymerization initiator)
As radical photopolymerization initiators, benzoin derivatives, benzyl ketals [for example, Ciba Specialty Chemicals Co., Ltd., trade name: Irgacure 651], α-hydroxyacetophenones [for example, Ciba -Specialty Chemicals Co., Ltd., trade names: Darocur 1173, Irgacure 184, Irgacure 127], α-aminoacetophenones [for example, Ciba Specialty Chemicals, Inc., trade names: Irgacure 907, Irgacure 369], Combination use of α-aminoacetophenones and thioxanthones (for example, isopropylthioxanthone, diethylthioxanthone), acylphosphine oxides [for example, Ciba Specialty Chemicals, Inc., trade name: Irgacure 8 9], and the like, as a hydrogen abstraction type, combined use of benzophenones and amines, combination and the like of the thioxanthone and amine. Further, an intramolecular cleavage type and a hydrogen abstraction type may be used in combination. Of these, oligomerized α-hydroxyacetophenone and acrylated benzophenones are preferred. More specifically, oligo [2-hydroxy-2-methyl-1- [4- (1-methylvinyl) phenyl] propanone] [for example, Lamberti S. et al. p. A product, trade name: ESACURE KIP150, etc.], acrylated benzophenone [for example, trade name: Ebecryl P136, etc., manufactured by Daicel UCB Co., Ltd.], imide acrylate, and the like.
In addition to the above-mentioned radical photopolymerization initiators, 1- [4- (2-hydroxyethoxy) phenyl] -2-methyl-1-propan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone 1-hydroxy-cyclohexyl-ketone and benzophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2,4,6-trimethylbenzoylphenylphosphine oxide, 2,4,6- Trimethylbenzoylphenylphenylethoxyphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1,2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2- Methyl-1-[(4-methylthio) phenyl] -2-morpholinopro 1-one, benzoyl methyl ether, benzoyl ethyl ether, benzoyl butyl ether, benzoyl isopropyl ether, bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide, 2-hydroxy-2-methyl- [4- (1- Methylvinyl) phenyl] propanol oligomer, mixture of 2-hydroxy-2-methyl- [4- (1-methylvinyl) phenyl] propanol oligomer and 2-hydroxy-2-methyl-1-phenyl-1-propanone, isopropylthioxanthone , Methyl o-benzoylbenzoate, [4- (methylphenylthio) phenyl] phenylmethane, and the like can also be used.
The amount of radical photopolymerization initiator compounded in the photocurable composition is 0.01 to 5 parts by mass, preferably 0.1 to 5 parts by mass with respect to 100 parts by mass in total of components (1) and (2). 3 parts by mass, more preferably 0.2-2 parts by mass.

((4) Thermal radical polymerization initiator)
In the present invention, it is necessary to use a thermal radical polymerization initiator together with the component (3) in order to increase the efficiency of the curing process of the cured product and to effectively reduce the outgas generation from the cured product.
Examples of thermal radical polymerization initiators include ketone peroxide polymerization initiators (H—OO—CR′R ″ —OO—H, etc.), hydroperoxide polymerization initiators (R—OOH), and dialkyl peroxide polymerizations. Initiator (R—OO—R ′), peroxyketal (peroxyacetal) polymerization initiator (R—OO—CR′R ″ —OO—R ′ ″), peroxyester polymerization initiator ( R-CO-OO-R '), peroxydicarbonate polymerization initiator (R-O-CO-OO-CO-O-R'), diacyl peroxide polymerization initiator (R-CO-OO-CO) -R ') and the like; and azo compounds such as 2,2'-azobisisobutyronitrile. R, R ′, R ″, R ′ ″ each independently represents an alkyl group or an aryl group, and the “—CR′R ″ —” site is combined with a carbon atom. An aliphatic ring (for example, a cyclohexane ring) may be formed. These may be used individually by 1 type and may use 2 or more types together.
As the thermal radical polymerization initiator, an organic oxide is preferable from the viewpoint of easy generation of radicals at a baking temperature described later, and high reactivity and storage stability, and a ketone peroxide polymerization initiator, Hydroperoxide polymerization initiators, dialkyl peroxide polymerization initiators, peroxyketal polymerization initiators, and peroxyester polymerization initiators are more preferable. Furthermore, from the viewpoint of hydrogen abstraction ability in the molecular chain, a ketone peroxide polymerization initiator, a hydroperoxide polymerization initiator, a dialkyl peroxide polymerization initiator, and a peroxyketal polymerization initiator are more preferable.

Examples of the ketone peroxide polymerization initiator include methyl isobutyl ketone peroxide, methyl ethyl ketone peroxide, and cyclohexanone peroxide.
Examples of the hydroperoxide-based polymerization initiator include 2,5-bis (hydroperoxy) -2,5-dimethylhexane, t-butyl hydroperoxide, cumene hydroperoxide, tetramethylbutyl hydroperoxide, and the like. It is done.
Examples of the dialkyl peroxide polymerization initiator include 2,5-dimethyl-2,5-bis (t-butyldioxy) -3-hexane, di-t-butyl peroxide, dicumyl peroxide, and the like.
Examples of the peroxyketal polymerization initiator include 1,1-di (t-butylperoxy) cyclohexane, 1,1-bis (t-butyldioxy) -3,3,5-trimethylcyclohexane, butyl-4,4. -Bis (t-butyldioxy) valerate etc. are mentioned.
Examples of peroxyester polymerization initiators include acetyl peroxide, lauroyl peroxide, di-t-butyldiperoxyisophthalate, 3,3 ′, 4,4′-tetrakis (t-butyldioxycarbonyl) benzophenone. 1,1,3,3-tetramethylbutylperoxyneodecanate and the like.
Examples of the peroxydicarbonate-based polymerization initiator include diisopropyl peroxydicarbonate, di-sec-butyl peroxydicarbonate, and the like.
Examples of the diacyl peroxide polymerization initiator include dibenzoyl peroxide, di (3-methylbenzoyl) peroxide, 3,5,5-trimethylhexanoyl peroxide, and dilauroyl peroxide.

(Other ingredients)
In addition to the components (1) to (4), a polythiol compound having 2 to 6 mercapto groups in the molecule may be mixed together.
The polythiol compound is not particularly limited as long as it has 2 to 6 mercapto groups in the molecule. For example, aliphatic polythiols such as alkanedithiol having about 2 to 20 carbon atoms, xylylene dithiol, etc. Aro-aliphatic polythiols, polythiols formed by replacing halogen atoms of halohydrin adducts of alcohols with mercapto groups, polythiols made of hydrogen sulfide reaction products of polyepoxide compounds, and having 2 to 6 hydroxyl groups in the molecule Examples include polythiols composed of esterified products of polyhydric alcohols and thioglycolic acid, β-mercaptopropionic acid, or β-mercaptobutanoic acid.
Examples of the polyhydric alcohol having 2 to 6 hydroxyl groups in the molecule include alkanediol having 2 to 20 carbon atoms, poly (oxyalkylene) glycol, glycerol, diglycerol, trimethylolpropane, ditrimethylolpropane, and pentaerythritol. And dipentaerythritol.

  Specific examples of the polythiol compound include, for example, ethylene glycol di (thioglycolate), ethylene glycol di (β-mercaptopropionate), ethylene glycol di (β-mercaptobutanoate), trimethylene glycol di (thioglycolate). , Trimethylene glycol di (β-mercaptopropionate), trimethylene glycol di (β-mercaptobutanate), propylene glycol di (thioglycolate), propylene glycol di (β-mercaptopropionate), propylene glycol di (Β-mercaptobutanate), 1,3-butanediol di (thioglycolate), 1,3-butanediol di (β-mercaptopropionate), 1,3-butanediol di (β-mercaptobutanate) ), 1,4-butane All di (thioglycolate), 1,4-butanediol di (β-mercaptopropionate), 1,4-butanediol di (β-mercaptobutanate), neopentyl glycol di (thioglycolate), neopentyl Glycol di (β-mercaptopropionate), neopentyl glycol di (β-mercaptobutanate), 1,6-hexanediol di (thioglycolate), 1,6-hexanediol di (β-mercaptopropionate) ), 1,6-hexanediol di (β-mercaptobutanate), 1,8-octanediol di (thioglycolate), 1,8-octanediol di (β-mercaptopropionate), 1,8- Octanediol di (β-mercaptobutanate), 1,9-nonanediol di (thioglycolate) 1,9-nonanediol di (β-mercaptopropionate), 1,9-nonanediol di (β-mercaptobutanate), cyclohexane-1,4-dimethanoldi (thioglycolate), cyclohexane-1,4 -Dimethanol di (β-mercaptopropionate), cyclohexane-1,4-dimethanol di (β-mercaptobutanate), diethylene glycol di (thioglycolate), diethylene glycol di (β-mercaptopropionate), diethylene glycol di (β- Mercaptobutanate), triethylene glycol di (thioglycolate), triethylene glycol di (β-mercaptopropionate), triethylene glycol di (β-mercaptobutanate), polyethylene glycol di (thioglycolate), poly Reethylene glycol di (β-mercaptopropionate), polyethylene glycol di (β-mercaptobutanate), dipropylene glycol di (thioglycolate), dipropylene glycol di (β-mercaptopropionate), dipropylene glycol di (Β-mercaptobutanate), tripropylene glycol di (thioglycolate), tripropylene glycol di (β-mercaptopropionate), tripropylene glycol di (β-mercaptobutanate), polypropylene glycol di (thioglycolate) ), Polypropylene glycol di (β-mercaptopropionate), polypropylene glycol di (β-mercaptobutanoate), polytetramethylene ether glycol di (thioglycolate), polytetramethyle Ether glycol di (β-mercaptopropionate), polytetramethylene ether glycol di (β-mercaptobutanate), di (thioglycolate) of cyclohexane-1,4-dimethanol ethylene oxide adduct, cyclohexane-1 , 4-dimethanol ethylene oxide adduct di (β-mercaptopropionate), cyclohexane-1,4-dimethanol ethylene oxide adduct di (β-mercaptobutanate), hydrogenated bisphenol A ethylene oxide adduct Di (thioglycolate), hydrogenated bisphenol A ethylene oxide adduct di (β-mercaptopropionate), hydrogenated bisphenol A ethylene oxide adduct di (β-mercaptobutanate), cyclohexane-1,4 -Dimethanol Di (thioglycolate) of pyrene oxide adduct, di (β-mercaptopropionate) of cyclohexane-1,4-dimethanol propylene oxide adduct, (β of cyclohexane-1,4-dimethanol propylene oxide adduct -Mercaptobutanate), di (thioglycolate) of hydrogenated bisphenol A propylene oxide adduct, di (β-mercaptopropionate) of hydrogenated bisphenol A propylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct Di (β-mercaptobutanate), glycerol tri (thioglycolate), glycerol tri (β-mercaptopropionate), glycerol tri (β-mercaptobutanate), diglycerol tetra (thioglycolate), diglycerol Tiger (β-mercaptopropionate), diglyceroltetra (β-mercaptobutanate), trimethylolpropane tri (thioglycolate), trimethylolpropane tri (β-mercaptopropionate), trimethylolpropane tri (β -Mercaptobutanate), ditrimethylolpropane tetra (thioglycolate), ditrimethylolpropane tetra (β-mercaptopropionate), ditrimethylolpropane tetra (β-mercaptobutanate), pentaerythritol tetra (thioglycolate), Pentaerythritol tetra (β-mercaptopropionate), pentaerythritol tetra (β-mercaptobutanate), dipentaerythritol hexa (thioglycolate), dipentaerythritol hexa beta-mercaptopropionate), dipentaerythritol hexa (beta-mercapto pig sulfonate) and the like.

Further, when mixing and reacting the components (1) to (4), if an inorganic filler and / or an organic thickener is added, the composition has thixotropy and the moldability of the mixture is increased. Can be improved.
Examples of the inorganic filler include silica (SiO ₂ ), alumina, titania, and viscosity mineral. Among these, silica powder, silica powder subjected to hydrophobic treatment or a mixture thereof is preferable. More specifically, silica fine powder pulverized by a dry method [for example, product name: Aerosil 300 manufactured by Nippon Aerosil Co., Ltd.], fine powder obtained by modifying this silica fine powder with trimethyldisilazane [for example, Japan Aerosil Co., Ltd., trade name: Aerosil RX300, etc.] and fine powder obtained by modifying the above silica fine powder with polydimethylsiloxane [for example, Nippon Aerosil Co., Ltd., trade name: Aerosil RY300, etc.].
The average particle diameter of the inorganic filler is preferably 5 to 50 μm, more preferably 5 to 12 μm, from the viewpoint of thickening and thixotropy.
When adding an inorganic filler, the addition amount is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 7 parts by mass, with respect to 100 parts by mass in total of components (1) and (2). More preferably, it is 1-5 mass parts.

As the organic thickener, hydrogenated castor oil, amide wax or a mixture thereof is preferable. Specifically, as an organic thickener, hydrogenated castor oil which is a hydrogenated product of castor oil (non-drying oil whose main component is ricinoleic acid) [for example, product name: ADVITROL100, Enomoto Kasei Co., Ltd. Product name: Disparone 305, etc.] and high-grade amide wax which is a compound having an amide bond [for example, trade name: Disparon 6500, manufactured by Enomoto Kasei Co., Ltd.], and the like.
When adding an organic thickener, the addition amount is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 7 parts by mass with respect to 100 parts by mass in total of components (1) and (2). More preferably, it is 1 to 5 parts by mass.

In the present invention, a terminal (meth) acrylate oligomer may be further added and reacted. By blending the terminal (meth) acrylate oligomer, the viscosity of the photocurable composition can be adjusted, and physically, a decrease in hardness, an improvement in Eb (elongation) and Tb (breaking strength), etc. Can be achieved. The terminal (meth) acrylate oligomer refers to an oligomer having an acryloyl group or a methacryloyl group at one end or both ends.
Examples of the terminal (meth) acrylate oligomer include hydrogenated polybutadiene (meth) acrylate oligomer, polyester (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, urethane (meth) acrylate oligomer, polyol (meth) acrylate An oligomer etc. are mentioned.
The terminal (meth) acrylate oligomer is preferably a hydrocarbon oligomer, that is, a non-hydrogenated or hydrogenated oligomer or a terminal (meth) acrylate hydrogenated oligomer, from the viewpoint of moisture permeability and weather resistance. The weight average molecular weight of the terminal (meth) acrylate oligomer is preferably 5,000 to 40,000, more preferably 5,000 to 15,000. When the weight average molecular weight is within this range, there are advantages that it is easy to handle as a liquid raw material and the cured product has low hardness.

  When adding a terminal (meth) acrylate oligomer, the addition amount is from the viewpoint of maintaining the weather resistance of the cured product and keeping moisture permeability low, with respect to a total of 100 parts by mass of the components (1) and (2), Preferably it is 120 mass parts or less, More preferably, it is 30 mass parts or less, More preferably, it is 10 mass parts or less, More preferably, it is 5 mass parts or less.

In the present invention, a stabilizer or the like may be further added and reacted.
As a stabilizer, triethylene glycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate] [for example, Ciba Specialty Chemicals Co., Ltd., trade name: “IRGANOX ( Registered trademark) 245 ", manufactured by Asahi Denka Kogyo Co., Ltd., trade name:" ADEKA STAB (registered trademark) AO-70 ", etc.], 3,9-bis {2- [3- (3-t-butyl-4- Hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl} -2,4,8,10-tetraoxaspiro [5.5] undecane [for example, manufactured by Asahi Denka Kogyo Co., Ltd., trade name: Phenolic antioxidants such as “ADK STAB (registered trademark) AO-80” and the like.
When a stabilizer is added, the addition amount is preferably 0.1 to 5 parts by mass, more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass in total of components (1) and (2). More preferably, it is 0.5 to 2 parts by mass.

  Furthermore, from the viewpoint of improving the adhesion with electronic components when the cured product of the present invention is used as a sealing material or gasket material for electronic components, terpene resin, terpene phenol resin, coumarone resin, coumarone-indene resin, petroleum-based You may make it react by adding additives, such as various tackifiers, such as a hydrocarbon and a rosin derivative, and coloring agents, such as titanium black. When adding these, the addition amount is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 3 parts by mass with respect to 100 parts by mass in total of components (1) and (2). .

In the present invention, the components (1) to (4) and, if necessary, the above-mentioned other components are mixed to form a photocurable composition, and then irradiated with active energy rays such as ultraviolet rays and electron beams to react. Cured to produce a cured product.
There is no restriction | limiting in particular in the mixing method of each component, A well-known method is applicable. For example, each component can be kneaded using a kneader capable of adjusting the temperature, for example, a single screw extruder, a twin screw extruder, a planetary mixer, a twin screw mixer, a high shear mixer, and the like.
Examples of the active energy rays include ionizing radiation such as ultraviolet rays and electron beams, α rays, β rays, and γ rays. Among these, ultraviolet rays are preferable. Examples of the ultraviolet ray source include a xenon lamp, a low-pressure mercury lamp, a high-pressure mercury lamp, a metal halide lamp, and a microwave excimer lamp. The atmosphere for irradiating the active energy rays is preferably an inert gas atmosphere such as nitrogen gas or carbon dioxide gas, or an atmosphere with a reduced oxygen concentration, but can be sufficiently cured even in a normal air atmosphere. The irradiation atmosphere temperature is usually preferably 10 to 200 ° C, more preferably 10 to 100 ° C, and further preferably 10 to 80 ° C. The integrated light quantity is preferably 2,000 to 10,000 mJ / cm ² , but in the present invention, 2,000 to 6,000 mJ / cm ² is sufficient, and even 2,000 to 4,000 mJ / cm ^2. It is enough.

In addition, by irradiating the obtained cured product with active energy rays again, the properties can be stabilized and the generation amount of outgas can be reduced. However, according to the method of the present invention, such an operation is performed. Even if it is not necessary, it can be sufficiently stabilized and the amount of outgas generated can be reduced. Moreover, it is usually performed to reduce generation of outgas from the cured product by sufficiently heating (baking) the obtained cured product, but the cured product obtained by the method of the present invention is used. If so, unreacted components and low-molecular components that are outgas generation factors are reduced, so that the baking operation can be shortened or omitted in some cases, and productivity can be increased. In addition, baking temperature becomes like this. Preferably it is 80-180 degreeC, More preferably, it is 100-170 degreeC, More preferably, it is 130-170 degreeC.
The cured product thus obtained has a JIS-A hardness measured by a type A durometer in accordance with JIS K6253 of 58 degrees or less, and has a sufficient sealing property. The JIS-A hardness of the cured product is more preferably 10 to 55 degrees, further preferably 20 to 55 degrees, and particularly preferably 25 to 52 degrees.
Moreover, the moisture permeability of the obtained hardened | cured material is 40 g / m < ² > * 24h or less, and the function as a sealing material or a gasket is fully exhibited. More specifically, the moisture permeability of the cured product is 15 g / m ² · 24 h or less, and more specifically about 3 to 10 g / m ² · 24 h.

In addition, the photocurable composition obtained by mixing each component is applied to an adherend, and then cured by irradiation with energy rays, whereby the gasket material for electronic components of the present invention and other electronic component seals The material can be manufactured. As the adherend, for example, one made of a hard resin can be used, but a metal one is preferable from the viewpoint of workability. There is no particular limitation on the metal, for example, cold-rolled steel sheet, galvanized steel sheet, aluminum / zinc alloy plated steel sheet, stainless steel sheet, aluminum plate, aluminum alloy plate, magnesium plate, magnesium alloy plate, etc. Can be used. Moreover, what injection-molded magnesium can also be used. From the viewpoint of corrosion resistance, a metal subjected to electroless nickel plating is preferable. As this electroless nickel plating treatment method, a known method conventionally applied to metal materials, for example, nickel sulfate, sodium hypophosphite, lactic acid, propionic acid and the like at an appropriate ratio of pH 4-5, A method of immersing a metal plate in an electroless nickel plating bath made of an aqueous solution having a temperature of about 85 to 95 ° C. can be used.
In addition, applications of the sealing material for electronic parts include gaskets for HDDs, liquid crystal seals, and the like. The thickness of the sealing material can be appropriately selected depending on the application, but is usually about 0.1 to 2 mm.

Application of the photocurable composition to a substrate such as an adherend can be performed by an arbitrary method using a coating liquid in which the temperature of the composition is adjusted as necessary and adjusted to a constant viscosity, For example, methods such as gravure coating, roll coating, spin coating, reverse coating, bar coating, screen coating, blade coating, air knife coating, dipping, dispensing, and inkjet can be used.
In the sealing material, the cross-sectional shape of the sealing layer is such that the sealing layer is higher than the sealing layer width 1 from the viewpoint of efficiently using a space in an electronic device such as an HDD or a printing device while ensuring good sealing performance. Is preferably 0.2 to 2, more preferably 0.3 to 2. When the height cannot be obtained at one time, it can be applied in several times. In this case, it is possible to cure by irradiating energy rays every time one step is applied.
The sealing material for electronic components of the present invention is suitable as a gasket material for electronic components, and particularly suitable as a gasket material for hard disk devices.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
The outgas generation amount, moisture permeability, weather resistance and hardness were measured according to the following methods.

(Outgas generation amount)
The outgas content per 200 mg of the cured product was measured by a gas chromatograph mass spectrometer (GC-MS) and used as an index of the outgas generation amount.
-GC-MS analysis conditions-
GC conditions:
Use column "capillary column" (length 30m x inner diameter 250μm)
Oven (Condition; temperature rise from 40 ° C to 300 ° C)
Inlet temperature 250 ℃
Carrier gas ... Helium injection mode ... Splitless MS condition:
Measurement method ... SCAN method Interface temperature 280 ℃
Ion source temperature 230 ° C
Detector voltage 1500V
(Moisture permeability)
The adhesive composition was formed into a film with a thickness of about 1 mm by a coater and cured under the ultraviolet irradiation conditions shown in Table 1. Using this cured product, in accordance with JIS Z0208, the moisture permeability was measured by the cup method under the conditions of 40 ° C. and relative humidity of 95%, and used as a moisture permeability index.
(Weather resistance: Sunshine weather deterioration test)
Using a test apparatus “Sunshine Super Weather Meter” manufactured by Suga Test Instruments Co., Ltd., the degree of cracking and yellowing that occurred on the surface of the cured product after 100 hours was confirmed and evaluated according to the following evaluation criteria.
-Crack-
○: No crack △: Some cracks ×: Many cracks-Yellowing-
○: No yellowing △: Slightly yellowing ×: Fully yellowing (hardness)
In accordance with JIS K6253, the hardness of the cured product was measured with a type A durometer. A test body having a thickness of about 6 mm obtained by laminating seven sheets having a thickness of about 0.9 mm was used.

Production Example 1 (Production of terminal-modified SBR)
First, 1 mol of 1,3- (diisopropenyl) benzene was added to cyclohexane that had been sufficiently dehydrated and purified, and then 2 mol of triethylamine and 2 mol of sec-butyllithium were sequentially added, and the mixture was stirred at 50 ° C. for 2 hours. A polymerization initiator was prepared.
In a 7 L polymerization reactor purged with argon, 1.9 kg of dehydrated and purified cyclohexane, 2.0 kg of a hexane solution of 12.9-butadiene monomer of 22.9% by mass, and a cyclohexane solution of 20.0% by mass of styrene monomer were added. After adding 130.4 ml of a hexane solution of 0.765 kg, 1.6 mol / L of 2,2-di (tetrahydrofuryl) propane, 108.0 ml of a 0.5 mol / L dilithium polymerization initiator was added to perform polymerization. Started.
Polymerization was carried out for 1.5 hours while raising the temperature of the polymerization reactor to 50 ° C., then 108.0 ml of 1 mol / L ethylene oxide cyclohexane solution was added, and the mixture was further stirred for 2 hours, and then 50 ml of isopropyl alcohol was added. did. A hexane solution of the polymer was precipitated in isopropyl alcohol and sufficiently dried to obtain a polymer polyol. This polymer polyol is a non-hydrogenated styrene-butadiene copolymer containing hydroxyl groups at both ends, has a styrene content of 25% by mass, and is converted into polystyrene using a gel permeation chromatography (GP) method. The weight average molecular weight determined by the above was 14,500 and the molecular weight distribution was 1.20.
(Reaction with unsaturated hydrocarbon group-containing compound)
100 g of the sufficiently dried polymer polyol was dissolved in cyclohexane, and 3.76 g of 2-acryloyloxyethyl isocyanate (manufactured by Showa Denko KK: Karenz AOI) was slowly added dropwise with stirring at 40 ° C., The mixture was further stirred for 4 hours, precipitated in isopropyl alcohol and dried to obtain a terminal-modified styrene-butadiene copolymer (terminal-modified SBR) which is a liquid resin.

Production Example 2 (Production of terminal-modified hydrogenated SBR)
In the same manner as in Production Example 1, a polymer polyol, that is, a styrene-butadiene copolymer containing hydroxyl groups at both ends was produced. The styrene content of the polymer polyol was 25% by mass, the weight average molecular weight determined by polystyrene conversion using a gel permeation chromatography (GP) method was 14,500, and the molecular weight distribution was 1.20.
(Hydrogenation treatment)
120 g of the obtained polymer polyol was dissolved in 1 L of sufficiently dehydrated and purified hexane, and then a catalyst solution of nickel naphthenate, triethylaluminum, and butadiene prepared in a separate container in a 1: 3: 3 (molar ratio) was used together. It charged so that it might become 1 mol of nickel with respect to 1,000 mol of butadiene parts in a polymer solution. Hydrogen was added under pressure to 27,580 hPa (400 psi) in a sealed reaction vessel, and a hydrogenation reaction was performed at 110 ° C. for 4 hours. Thereafter, the catalyst residue was extracted and separated with hydrochloric acid of 3N concentration, and further centrifuged to separate the catalyst residue by sedimentation. Thereafter, the obtained hydrogenated polymer polyol was precipitated in isopropyl alcohol and further sufficiently dried.
(Reaction with unsaturated hydrocarbon group-containing compound)
100 g of the above sufficiently dried hydrogenated polymer polyol was dissolved in cyclohexane, and 3.76 g of 2-acryloyloxyethyl isocyanate (manufactured by Showa Denko KK: Karenz AOI) was slowly added dropwise while stirring at 40 ° C. Then, the mixture was further stirred for 4 hours, precipitated in isopropyl alcohol and dried to obtain a terminal-modified hydrogenated styrene-butadiene copolymer (terminal-modified hydrogenated SBR) which is a liquid resin.

Examples 1-3 and Comparative Examples 1-4
Each component shown in Table 1 was kneaded with a planetary mixer at 25 ° C. in each compounding amount to obtain a photocurable composition. While conveying each photocurable composition obtained with a conveyor belt, using a metal halide lamp as a light source, an ultraviolet irradiation device (device name “Light Hammer 6”, manufactured by Fusion UV Systems Japan Co., Ltd.), A cured product was obtained by irradiating with ultraviolet rays according to the following condition 1 or 2 in an air atmosphere and baking appropriately.
Table 1 shows the results of measuring the outgas generation amount, moisture permeability, and hardness of the obtained cured product.
(UV irradiation conditions)
Condition 1: Illuminance 1100 mW / cm ² (wavelength 320 to 390 nm), integrated light quantity 2,500 mJ / cm ² (corresponding to one irradiation)
Condition 2: Illuminance 1100 mW / cm ² (wavelength 320 to 390 nm), integrated light amount 7,500 mJ / cm ² (corresponding to 3 irradiations)

The annotations in the table are explained as follows.
* 1: Terminally modified hydrogenated SBR obtained in Production Example 2
* 2: Terminal modified SBR obtained in Production Example 1 (non-hydrogenated)
* 3: Trade name “UV-3000B”, photocurable polyurethane acrylate, manufactured by Nippon Synthetic Chemical Co., Ltd., weight average molecular weight 18,000
* 4: Trade name “Irgacure (registered trademark) 184” (1-hydroxycyclohexyl-phenyl-ketone, manufactured by Ciba Specialty Chemicals Co., Ltd.)
* 5: 1,1-di (t-butylperoxy) cyclohexane * 6: Heated at 160 ° C. for 4 hours.

  From Table 1, the outgas generation amount is reduced even if the cured product obtained in the Examples has a small ultraviolet irradiation amount. Furthermore, since the moisture permeability is low, the weather resistance is high, and the hardness is between 40 and 50 degrees, it is suitable as a sealing material for electronic parts, particularly as a gasket material for electronic parts.

  The cured product obtained by the present invention can be used as a sealing material for various uses, for example, for gaskets for HDDs, liquid crystal seals, and the like.

Claims (8)

  At least (1) obtained by reacting a hydrogenated or non-hydrogenated conjugated diene polymer polyol or a hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol with an unsaturated hydrocarbon group-containing compound. (3) 0.01 to 5 parts by mass of a radical photopolymerization initiator with respect to a total of 100 parts by mass of the liquid resin 90 to 30% by mass and (2) monofunctional or bifunctional (meth) acrylate 10 to 70% by mass, And (4) The manufacturing method of hardened | cured material by mixing 0.1-10 mass parts of thermal radical polymerization initiators, and making it react by irradiating an active energy ray. Hydrogenated or non-hydrogenated conjugated diene polymer polyol or hydrogenated or non-hydrogenated conjugated diene-aromatic vinyl copolymer polyol is produced by the following steps (A) to (B) or (A) to (C). The manufacturing method of the hardened | cured material of Claim 1 manufactured.
(A) Polymerization of a conjugated diene monomer or copolymerization of a conjugated diene monomer and an aromatic vinyl monomer with a dilithium initiator in a saturated hydrocarbon solvent, and a weight average molecular weight The process of manufacturing the conjugated diene type polymer or conjugated diene-aromatic vinyl type copolymer which has 5,000-40,000 and molecular weight distribution 3.0 or less.
(B) The conjugated diene polymer or conjugated diene-aromatic vinyl copolymer is reacted with an alkylene oxide to produce a conjugated diene polymer polyol or a conjugated diene-aromatic vinyl copolymer polyol. Process.
(C) Hydrogenation reaction of the conjugated diene polymer polyol or conjugated diene-aromatic vinyl copolymer polyol, and hydrogenated conjugated diene polymer polyol or hydrogenated conjugated diene-aromatic vinyl copolymer polyol Manufacturing process.   The method for producing a cured product according to claim 2, wherein the aromatic vinyl monomer is at least one selected from styrene, α-methylstyrene, and paramethylstyrene.   The manufacturing method of the hardened | cured material in any one of Claims 1-3 whose unsaturated hydrocarbon group of the said unsaturated hydrocarbon group containing compound is a (meth) acryloyl group.   The thermal radical polymerization initiator is a ketone peroxide polymerization initiator, a hydroperoxide polymerization initiator, a dialkyl peroxide polymerization initiator, a peroxyketal polymerization initiator, a peroxyester polymerization initiator, a peroxy ester The manufacturing method of the hardened | cured material in any one of Claims 1-4 which is at least 1 sort (s) selected from the group which consists of a dicarbonate type | system | group polymerization initiator and a diacyl peroxide type | system | group polymerization initiator.   Hardened | cured material obtained by the manufacturing method in any one of Claims 1-5.   The sealing material for electronic components which consists of a hardened | cured material of Claim 6.   The gasket material for electronic components which consists of a hardened | cured material of Claim 6.