JP2013028681A - Photocurable resin composition and sealing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a photocurable resin composition excellent in the water vapor barrier property and resistance to electrode corrosion, having low viscosity, and capable of being cured by ultraviolet rays even in the environment in which ultraviolet rays of a specific wavelength is shielded, and to provide a sealing material made of the photocurable resin composition.SOLUTION: The photocurable resin composition includes rubber (A) containing a terminal-modified hydrogenated conjugated diene-aromatic vinyl-based copolymer (a1) and/or a terminal-modified hydrogenated conjugated diene-based copolymer (a2); a reactive diluent (B); and α-aminoacetophenone and/or acylphosphine oxide-based photopolymerization initiator (C). The content ratio of the (A) component and the (B) component [(A):(B)] is 10:90-90:10 in mass, and the content of the (C) component is 0.01-15 pts.mass based on 100 pts.mass total of the (A) component and the (B) component. The sealing material is made of the photocurable resin composition.

Description

  The present invention is a photocurable resin composition that is excellent in water vapor barrier properties and electrode corrosion resistance, has low viscosity, and can be cured with ultraviolet light even under an ultraviolet blocking environment of a specific wavelength, and the photocurable property The present invention relates to a sealing material made of a resin composition.

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 the like 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 the like 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 hydrogenated polybutadiene-based photocurable resin, so that the molecular weight between cross-linking points is small and high cross-linking and inhibits rubber elasticity, so that the water vapor permeability is excellent, but the elastic modulus is high, Since there is no elongation and the tensile strength is small and the fatigue property is also poor, when it is used as a sealing material or the like, it cracks and is not practical.
Therefore, it is possible to control the molecular weight and molecular weight distribution to increase the molecular weight, to have excellent photocurability, and to greatly improve the physical properties after curing as described above. A photocurable liquid resin containing a coalescence has been developed (see Patent Document 5).

Japanese Patent Laid-Open No. 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, and is effectively used as a sealing material. However, when used as a sealing material for electronic parts, particularly when used as a sealing material (sealing material) around the electrode, corrosion due to the electrode may be significant. In addition, as a sealing method for a multilayer film, a method is often employed in which a sealing material is applied to an interface portion of a film that has been pasted together, and the sealing material is made to enter between the films using a capillary phenomenon and then cured by ultraviolet rays. ing. When the viscosity of the sealing material is high (for example, when the viscosity at 23 ° C. exceeds 50 Pa · s), there is a problem that the method cannot be adopted. Further, in order to impart weather resistance to the multilayer film, An ultraviolet blocking layer may be provided, but in this case, there is a problem that the sealing material that has entered between the films cannot be cured with ultraviolet rays.
Therefore, the problem of the present invention is a photocurable resin composition that is excellent in water vapor barrier properties and electrode corrosion resistance, has low viscosity, and can be cured with ultraviolet rays even in an ultraviolet blocking environment of a specific wavelength, and It is providing the sealing material which consists of this photocurable resin composition.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a terminal-modified hydrogenated conjugated diene-aromatic vinyl copolymer (a1) and / or a terminal-modified hydrogenated conjugated diene copolymer (a2). By using a rubber (A) containing a specific amount of a specific photopolymerization initiator (C) together with a reactive diluent (B), the water vapor barrier property and the electrode corrosion resistance are excellent. It has been found that a photo-curable resin composition having a low viscosity and capable of ultraviolet curing even in an environment where ultraviolet rays having a wavelength of 380 nm or less are blocked can be provided.

That is, the present invention relates to the following [1] to [8].
[1] Rubber (A) containing terminal-modified hydrogenated conjugated diene-aromatic vinyl copolymer (a1) and / or terminal-modified hydrogenated conjugated diene polymer (a2),
Reactive diluent (B), and α-aminoacetophenone and / or acylphosphine oxide photopolymerization initiator (C)
A photocurable resin composition comprising:
The content ratio [(A) :( B)] of the component (A) and the component (B) is 10:90 to 90:10 by mass ratio, and the content of the component (C) is the above ( The photocurable resin composition which is 0.01-15 mass parts with respect to a total of 100 mass parts of A) component and the said (B) component.
[2] The component (A) contains the component (a1) and the component (a2), and the mixing ratio [(a1) :( a2)] of the component (a1) and the component (a2) is The photocurable resin composition according to [1], wherein the ratio is 10:90 to 90:10.
[3] The photocurable resin composition according to the above [1], wherein the component (A) is one of the component (a1) and the component (a2).
[4] The above (1) to [3], wherein the component (a1) is a terminal acrylic-modified hydrogenated styrene butadiene rubber and the component (a2) is a terminal acrylic-modified hydrogenated butadiene rubber. The photocurable resin composition as described.
[5] The above [1] to [4], wherein the component (a1) has a weight average molecular weight of 2,000 to 40,000, and the component (a2) has a weight average molecular weight of 2,000 to 40,000. ] The photocurable resin composition in any one of.
[6] Any of the above [1] to [5], wherein the component (B) is a liquid photopolymerizable monovinyl monomer selected from vinyl esters, (meth) acrylic monomers, N-vinyl monomers, and polythiol compounds. The photocurable resin composition described in 1.
[7] The photocurable resin composition according to any one of [1] to [6], wherein a viscosity at 23 ° C. is 0.1 to 50 Pa · s.
[8] A sealing material comprising the photocurable resin composition according to any one of [1] to [7].

  The photocurable resin composition of the present invention is excellent in water vapor barrier properties and electrode corrosion resistance, has a low viscosity, and can be cured even under an environment where ultraviolet rays having a wavelength of 380 nm or less are blocked. A functional resin composition can be provided. Furthermore, since the cured product obtained by photocuring the photocurable resin composition has a low viscosity (Shore A hardness = 15 to 60 degrees), the photocurable resin composition is useful as a sealing material.

[Photocurable resin composition]
The photocurable resin composition of the present invention comprises a rubber containing a terminal-modified hydrogenated conjugated diene-aromatic vinyl copolymer (a1) and / or a terminal-modified hydrogenated conjugated diene copolymer (a2) (A2). ), A reactive diluent (B), and an α-aminoacetophenone and / or an acylphosphine oxide photopolymerization initiator (C), wherein the component (A) and the ( The content ratio [(A) :( B)] of the component B) is 10:90 to 90:10 by mass ratio, and the content of the component (C) is the component (A) and the component (B). 0.01-15 mass parts is contained with respect to a total of 100 mass parts of a component.
Hereinafter, each component which the photocurable resin composition of this invention contains is demonstrated in detail.

[(A) Rubber]
The rubber as component (A) is at least one of terminal-modified hydrogenated conjugated diene-aromatic vinyl copolymer (a1) and terminal-modified hydrogenated conjugated diene copolymer (a2) as an essential component. Containing. That is, the component (A) may be the component (a1) alone, the component (a2) alone, or a blend of two or more of the component (a1) or the component (a2). It may be a rubber, or may be a blend rubber comprising one or more components (a1) and (a2).
When the component (A) contains the component (a1) and the component (a2), the content ratio [(a1) :( a2)] of the component (a1) and the component (a2) is a photocurable resin composition. From the viewpoint of viscosity and hardness, the weight ratio is preferably 10:90 to 90:10, more preferably 30:70 to 70:30, and still more preferably 40:60 to 60:40.

((A1) terminal-modified hydrogenated styrene butadiene rubber, (a2) terminal-modified hydrogenated butadiene rubber)
Component (a1) is a liquid resin obtained by reacting a hydrogenated conjugated diene-aromatic vinyl copolymer polyol and an unsaturated hydrocarbon group-containing compound, and component (a2) is a hydrogenated conjugated diene polymer. It is a liquid resin obtained by reacting a polyol and an unsaturated hydrocarbon group-containing compound.
Such hydrogenated conjugated diene-aromatic vinyl copolymer polyol or hydrogenated conjugated diene polymer polyol is preferably produced by the following steps (I) to (III).
(I) A weight average molecular weight obtained by polymerizing a conjugated diene monomer or copolymerizing a conjugated diene monomer and an aromatic vinyl monomer with a dilithium initiator in a saturated hydrocarbon solvent. A step of producing a conjugated diene polymer or a conjugated diene-aromatic vinyl copolymer having 2,000 to 40,000 and a molecular weight distribution of 3 or less.
(II) A conjugated diene polymer polyol or a conjugated diene-aromatic vinyl copolymer polyol is produced by reacting the conjugated diene polymer or conjugated diene-aromatic vinyl copolymer with an alkylene oxide. Process.
(III) 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 (I) is living anionic polymerization, it can be polymerized by controlling the molecular weight and molecular weight distribution. As for the molecular weight, a polymer having a predetermined molecular weight can be polymerized depending on the amount of the dilithium initiator and the above monomer, and the molecular weight distribution is particularly at a weight average molecular weight of 2,000 or more (preferably 5,000 or more). It is easy to obtain a narrow polymer having 2 or less. If desired, anionic polymerization may be carried out in the presence of a randomizer.
Next, as the step (II), the polymer end or the copolymer obtained in the above step (I) (hereinafter sometimes referred to as a (co) polymer) and a polymer terminal which is a living anion By an equivalent reaction with an alkylene oxide, a conjugated diene polymer polyol or a conjugated diene-aromatic vinyl copolymer polyol (hereinafter referred to as (co) polymer polyol) having hydroxyl groups at both ends may be collectively referred to. ) Can be obtained.
Further, as step (III), a hydrogenation reaction (hereinafter referred to as hydrogenation reaction) is performed on the (co) polymer polyol obtained in step (II) 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 (I) 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 p-methylstyrene, and more preferably styrene, 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 by the said process (I), A well-known thing can be used. For example, Japanese Patent Publication No. 1-53681 discloses a monolithium compound in the presence of a tertiary amine in the presence of a disubstituted vinyl or alkenyl group-containing aromatic hydrocarbon (such as 1,3- (diisopropenyl) benzene). A method for producing a dilithium initiator by reacting with 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, the solvent of Unexamined-Japanese-Patent No. 2007-145949 can be referred.

  Examples of the alkylene oxide used in step (II) include ethylene oxide, propylene oxide, butylene oxide, and the like. This polyolation reaction (step (II)) is preferably performed immediately after the polymerization reaction (step (I)).

If the weight average molecular weight of the (co) polymer polyol obtained by the step (II) is 2,000 or more (preferably 5,000 or more), the molecular weight between the crosslinking points can be increased, and after the photocuring reaction The elastic modulus is preferably low and the elongation (Eb) can be increased. On the other hand, if a (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 polymerization is performed with a dilithium catalyst in step (I). Since it is not necessary to lower the solid content concentration as a polymerization process, the cost is preferable. The weight average molecular weight of the (co) polymer polyol obtained by the step (II) is more preferably 5,000 to 40,000, and further preferably 5,000 to 30,000. In addition, in this specification, a weight average molecular weight is the value calculated | required by polystyrene conversion on the basis of the monodispersed polystyrene by the gel permeation chromatography (GPC).
Moreover, if molecular weight distribution is 3 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. In addition, in this specification, molecular weight distribution is computed from the weight average molecular weight and number average molecular weight which were calculated | required by polystyrene conversion on the basis of the monodispersed polystyrene by the gel permeation chromatography (GPC).
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 or less, more preferably 2.0 or less, still more preferably 1.5 or less, and particularly preferably 1.2 or less.

The hydrogenation reaction in step (III) is performed by hydrogenating the (co) polymer polyol obtained in step (II) 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 (III) 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.

An unsaturated hydrocarbon group is introduced into the terminal of the hydrogenated (co) polymer polyol by reacting the hydrogenated (co) polymer polyol obtained as described above with an unsaturated hydrocarbon group-containing compound. The component (a1) or (a2) can be produced.
As the component (a1), a terminal acrylic-modified hydrogenated styrene butadiene rubber is preferable, and as the component (a2), a terminal acrylic-modified hydrogenated butadiene rubber is preferable. That is, 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.
Preferred examples of (meth) acryloyl isocyanate include 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyethyl isocyanate.

The weight average molecular weights of the terminal-modified hydrogenated styrene butadiene rubber (a1) and the terminal-modified hydrogenated butadiene rubber (a2) are preferably 2,000 to 40,000, more preferably 5,000 to 40,000, More preferably, it is 5,000-30,000, More preferably, it is 10,000-30,000, More preferably, it is 15,000-20,000.
The molecular weight distribution (Mw / Mn) of the terminal-modified hydrogenated styrene butadiene rubber (a1) and the terminal-modified hydrogenated butadiene rubber (a2) is preferably 3 or less, more preferably 2 or less, and even more preferably 1 .5 or less, particularly preferably 1.2 or less.
When the weight average molecular weights of the component (a1) and the component (a2) are within this range, the viscosity of the terminal-modified hydrogenated styrene butadiene rubber is not too high, the handleability is good, and the viscosity of the photopolymerization initiator. Can be lowered. Further, when the molecular weight distribution is 3 or less, reproducibility is easily obtained in mass production, and it becomes easy to obtain a (co) polymer having the same molecular weight.
The hydrogenation rate in the component (a1) and the component (a2) is preferably 50% or more, more preferably 70% or more, more preferably 80% or more, and still more preferably, from the viewpoint of water vapor barrier properties and heat resistance. Is 90% or more, particularly preferably 95% or more.
The content of the structural unit derived from styrene in the terminal-modified hydrogenated styrene-butadiene rubber (a1) (hereinafter referred to as styrene content) is not particularly limited, but is preferably 10 to 40 with respect to all the structural units. It is 10 mass%, More preferably, it is 10-30 mass%.

[(B) Reactive diluent]
The photocurable resin composition of the present invention contains a reactive diluent. The reactive diluent reduces the viscosity of the photocurable resin composition and facilitates application, and can be polymerized when the photocurable resin composition is photocured.
As a reactive diluent, for example, a liquid photopolymerizable monovinyl monomer selected from vinyl esters such as vinyl acetate, (meth) acrylic monomers, N-vinyl monomers, polythiol compounds, etc. can be used. A (meth) acryl monomer is preferred from the viewpoint of being present and the viewpoint of easily controlling the curing reaction.
Examples of (meth) acrylic monomers include n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, isomyristyl (meth) acrylate, isostearyl (meth) acrylate, n-octadecyl ( (Meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl ( Examples include (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, ester of (meth) acrylic acid and polyhydric alcohol, and the like. Among these, isobornyl (meth) acrylate and dicyclopentenyloxyethyl (meth) acrylate are preferable from the viewpoint of water vapor barrier properties and sealing properties.

Examples of the N-vinyl monomer include N, N-dimethylacrylamide, N-vinylpyrrolidone, N-vinylcaprolactam and the like.
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; aromatics such as xylylenedithiol Polythiols; polythiols obtained by substituting halogen atoms of halohydrin adducts of alcohols with mercapto groups; polythiols comprising hydrogen sulfide reaction products of polyepoxide compounds; polyhydric alcohols having 2 to 6 hydroxyl groups in the molecule And polythiols composed of esterified products of thioglycolic acid, β-mercaptopropionic acid or β-mercaptobutanoic acid.

  In the case where the component (A) and the component (B) are contained in the photocurable resin composition of the present invention, [(A) :( B)] is a mass ratio of 10:90 to 90 from the viewpoint of viscosity and hardness. : 10 is important. From this viewpoint, when (A) component and (B) component are contained, [(A) :( B)] is a mass ratio, preferably 20:80 to 80:20, more preferably 30:70 to 70. : 30, more preferably 40:60 to 60:40.

[(C) α-aminoacetophenone and / or acylphosphine oxide photopolymerization initiator]
The photocurable resin composition of the present invention contains at least one of α-aminoacetophenone and an acylphosphine oxide photopolymerization initiator as the component (C). Among the photopolymerization initiators, by containing at least one of α-aminoacetophenone and acylphosphine oxide photopolymerization initiators, it has excellent electrode corrosion resistance and can be used in an ultraviolet blocking environment with a wavelength of 380 nm or less. It can be set as the photocurable resin composition which can be hardened | cured. From this, it is presumed that aminoacetophenone and acylphosphine oxide photopolymerization initiators could absorb active energy rays having a wavelength of 380 nm or more. It is preferable to use at least the following α-aminoacetophenone from the viewpoint of providing a photocurable resin composition that is excellent in electrode corrosion resistance and can be cured by ultraviolet rays even in an ultraviolet blocking environment.

  As the acylphosphine oxide photopolymerization initiator, for example, those represented by the following general formula (1) or (2) are preferable.

In said general formula, R < ¹ > -R < ⁵ > represents a C1-C5 alkyl group and a C1-C5 alkoxy group each independently. R ⁶ represents an alkyl group having 1 to 15 carbon atoms. p ¹ ~p ⁵ are each independently an integer of 0 to 3. q represents 0 or 1;
As a C1-C5 alkyl group which R < ¹ > -R < ⁵ > represents each independently, a methyl group, an ethyl group, various propyl groups ("various" shows that a linear and all branched chains are included. The same applies hereinafter), and various butyl groups. Among these, a methyl group is preferable. Examples of the alkoxy group having 1 to 5 carbon atoms independently represented by R ^{1 to} R ⁵ include a methoxy group and an ethoxy group. Among these, a methoxy group is preferable.
Examples of the alkyl group having 1 to 15 carbon atoms represented by R ⁶ include a methyl group, an ethyl group, various propyl groups, various butyl groups, various hexyl groups, various octyl groups, various decyl groups, and various dodecyl groups. Among these, an alkyl group having 1 to 10 carbon atoms is preferable, an alkyl group having 4 to 10 carbon atoms is more preferable, and an alkyl group having 5 to 8 carbon atoms is more preferable.
In general formula (1), p ¹ is preferably 3. p ² is preferably 0 when q is 0, and is preferably 3 when q is 1. p ³ is preferably 0. In the general formula (2), p ⁴ and p ⁵ are both 2 are preferred.
Preferable specific examples of the acylphosphine oxide photopolymerization initiator represented by the general formula (1) or (2) are shown below, but are not particularly limited thereto.

In the present invention, the above specific photopolymerization initiator is used, but when other photopolymerization initiators such as α-aminoalkylphenone photopolymerization initiators are used instead, the electrode corrosion resistance is poor, Moreover, it becomes a photocurable resin composition that cannot be cured by ultraviolet light under an ultraviolet shielding environment of 380 nm or less.
Content of (C) component in the photocurable resin composition of this invention is 0.01-15 mass parts with respect to a total of 100 mass parts of (A) component and (B) component. When it is less than 0.01 parts by mass, the curability in an ultraviolet blocking environment with a wavelength of 380 nm or less is insufficient, and the sealing property (sealing property) of the photocurable resin composition becomes poor. On the other hand, even if it exceeds 15 parts by mass, the effect of addition reaches a peak, and the burden of manufacturing cost increases. From this viewpoint, the content of the component (C) in the photocurable resin composition is preferably 0.3 to 13 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (B). Preferably it is 0.5-13 mass parts, More preferably, it is 0.5-10 mass parts, More preferably, it is 0.5-7 mass parts, More preferably, it is 0.5-5 mass parts, Most preferably, it is 0.5- 3 parts by mass.
In addition, the photocurable resin composition of this invention may contain other photoinitiators other than the said (C) component in the grade which does not lose the effect of this invention. When these other photopolymerization initiators are contained, the content thereof is preferably 2 parts by mass or less, more preferably 1 part by mass with respect to 100 parts by mass of component (A) from the viewpoint of electrode corrosion resistance and the like. Hereinafter, it is further preferably 0.5 parts by mass or less, particularly preferably 0.1 parts by mass or less.

[(D) Additive]
The photocurable resin composition of the present invention may further contain various additives.
Although there is no restriction | limiting in particular as an additive, For example, coloring agents, such as a photosensitizer, an inorganic filler, a thickener, tackifying resin, titanium black, 1, 4- cyclohexylcarbodiimide, N, N'- ethylcarbodiimide, etc. And carbodiimide compounds.
-Photosensitizer-
Examples of photosensitizers include amine compounds such as aliphatic amines and aromatic amines; ureas such as o-tolylthiourea; sodium diethyldithiophosphate, s-benzylisothuronium-p-toluenesulfonate, and the like. Sulfur compounds; Nitriles such as N, N-disubstituted-p-aminobenzonitrile compounds; Phosphorus compounds such as tri-n-butylphosphine; Other nitrogen compounds such as N-nitrosohydroxylamine derivatives .

-Thickener-
By adding a thickener to the photocurable resin composition, thickening and thixotropic properties are imparted, and moldability can be improved. Examples of the thickener include inorganic fillers and organic thickeners.
Examples of the inorganic filler include surface-treated fine silica of wet silica and dry silica, and natural minerals such as organic bentonite. More specifically, silica fine powder pulverized by a dry method [for example, “Aerosil 300” (manufactured by Nippon Aerosil Co., Ltd.)], fine powder obtained by modifying this silica fine powder with trimethyldisilazane [for example, “Aerosil” RX300 "(manufactured by Nippon Aerosil Co., Ltd.) and the like] and fine powder obtained by modifying the silica fine powder with polydimethylsiloxane [for example," Aerosil RY300 "(manufactured by Nippon Aerosil Co., Ltd.)] and the like. 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 transparency.
Examples of the organic thickener include amide wax, hydrogenated castor oil, or a mixture thereof. More specifically, hydrogenated castor oil which is a hydrogenated product of castor oil (non-drying oil whose main component is ricinoleic acid) [for example, “ADVITOLOL 100” (manufactured by Zudchemy Catalyst Co., Ltd.), “Disparon (registered trademark) 305” (Made by Enomoto Kasei Co., Ltd.) and the like, and higher amide waxes which are compounds obtained by substituting hydrogen of ammonia with an acyl group [for example, “Disparon (registered trademark) 6500” (made by Enomoto Kasei Co., Ltd.)] and the like.
-Tackifying resin-
Examples of the tackifier resin include terpene resins, terpene phenol resins, coumarone resins, coumarone-indene resins, petroleum hydrocarbons, and rosin derivatives.

The photo-curable resin composition of the present invention is, for example, in a mixer such as a planetary mixer, the component (A), the component (B), the component (C), and the component (D) as necessary. Etc. are obtained by thoroughly mixing them. The photocurable resin composition thus obtained is applied to, for example, a portion to be sealed of an electronic component, or applied to an interfacial site between films of a multi-layer film laminated in advance, and the composition is formed by capillary action. Can be hardened and sealed (sealed) by irradiating with active energy rays. In addition, if the photocurable resin composition of this invention is used as a sealing material (sealing material), even if the outermost layer of a multilayer film is provided with the ultraviolet blocking layer, it can be cured by active energy rays. .
Examples of the active energy rays include particle rays, electromagnetic waves, and combinations thereof. Examples of the particle beam include an electron beam (EB) and an α ray, and examples of the electromagnetic wave include an ultraviolet ray (UV), a visible ray, an infrared ray, a γ ray and an X ray. Among these, it is preferable to use ultraviolet rays as active energy rays. Examples of the ultraviolet light 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 active energy ray is preferably irradiated in an inert gas atmosphere such as nitrogen gas or carbon dioxide gas or an atmosphere in which the oxygen concentration is lowered, but can be sufficiently cured even in a normal air atmosphere. The irradiation temperature is usually preferably 10 to 200 ° C., and the irradiation time is usually preferably 10 seconds to 60 minutes. The integrated light quantity is usually preferably 1,000 to 20,000 mJ / cm ² .

  The photocurable resin composition of the present invention preferably has a viscosity at 23 ° C. of 0.1 to 50 Pa · s, more preferably 0.5 to 30 Pa · s, still more preferably 0.5 to 15 Pa · s, and still more preferably. Is 1 to 10 Pa · s, particularly preferably 2 to 4 Pa · s, and has a low viscosity. Therefore, the photocurable resin composition of the present invention is applied to the interface portion of the film laminated in advance to utilize the capillary phenomenon. Thus, the photo-curable resin composition can enter between the films. The viscosity is a value measured according to the method described in the examples.

EXAMPLES Next, although an Example demonstrates this invention still in detail, this invention is not limited at all by these examples.
In addition, about the photocurable resin composition obtained by the Example and the comparative example, according to the following method, moisture permeability, electrode corrosion resistance, and a viscosity are evaluated or measured, and also this photocurable resin composition is wavelength 380nm. It was investigated whether it hardened | cured by the irradiation of the ultraviolet rays from which the following ultraviolet rays were interrupted | blocked. Moreover, the hardness of the hardened | cured material obtained by hardening this photocurable resin composition by ultraviolet irradiation was measured in accordance with the following method.

(Method of evaluating moisture permeability)
Using a moisture permeable cup of method A described in JIS L1099, measurement was performed under the conditions of 40 ° C. and 90% relative humidity in accordance with JIS Z0208. In addition, as a test body, the sheet | seat of thickness 0.86mm was used. It shows that it is excellent in water vapor | steam barrier property, so that a value is small.
(Evaluation method for electrode corrosion resistance)
A circuit is printed with indium-zinc composite oxide (IZO) on a polyethylene terephthalate film (PET film), the photocurable resin composition obtained in each example is sealed on the circuit with a thickness of about 1 mm, and UV irradiation is performed. And cured. Thereafter, a voltage of 80 V was applied to the circuit, and the circuit was left for 96 hours at 60 ° C. and 90% humidity. The resistance value before being left was subtracted from the resistance value after being left, and the obtained value was used as an index of electrode corrosion resistance. It shows that electrode corrosion resistance is so high that a numerical value is small.
(Measurement method of viscosity)
Under room temperature conditions (23 ° C.), the viscosity of the photocurable resin composition obtained in each example was measured with a rheometer “RS-600” (manufactured by Harke). The photocurable resin composition before curing was adjusted to 30 ° C., the shear stress was measured while changing the shear rate in the range of ¹ to 10 s ⁻¹ with a gap of 0.2 mm, and the shear rate and ½ of the stress. An approximate line by the least square method was drawn from the Casson plot in which the power was plotted, and the viscosity at the shear rate of 1 s ⁻¹ was calculated.

(Investigation of the possibility of curing by irradiating ultraviolet rays with a wavelength of 380 nm or less blocked)
On the photocurable resin composition obtained in each example, a PET film and a UV cut film with a wavelength of 380 nm or less were sequentially laminated, and active energy rays were irradiated from the UV cut film side. Thereafter, the PET film and the UV cut film were peeled off to check whether the residue was solid or liquid, and the photocurable resin composition was determined to be cured or uncured.
Irradiation with active energy rays was performed at an irradiance of 150 mW / cm ² (wavelength: 320 to 390 nm) at room temperature in an air atmosphere using an ultraviolet irradiator “SE-UV1501BA-LT” (manufactured by Sen Engineering Co., Ltd.). For a second.
(Measurement method of hardness)
The photo-curable resin composition obtained in each example was made into a sheet form, UV-cured, and then adjusted to have a thickness of about 6 mm by stacking the sheets, in accordance with JIS K6253 (type A durometer). Hardness was measured.
Irradiation with active energy rays was performed at an irradiance of 150 mW / cm ² (wavelength: 320 to 390 nm) at room temperature in an air atmosphere using an ultraviolet irradiator “SE-UV1501BA-LT” (manufactured by Sen Engineering Co., Ltd.). For a second.

<Production Example 1> Production of terminal-modified hydrogenated styrene-butadiene rubber In a reactor having an internal volume of 7 L purged with argon, 1.90 kg of dehydrated purified cyclohexane, 2 kg of hexane solution of 12.9-butadiene of 22.9% by mass, 20 kg After adding 0.573 kg of a 0.02 mass% styrene cyclohexane solution and 130.4 ml of a 1.6 mol / L hexane solution of 2,2-di (tetrahydrofuryl) propane, a 0.5 mol / L dilithium polymerization initiator is added. 108.0 ml was added to initiate the polymerization. The mixture was heated to 50 ° C., polymerized for 1.5 hours, 108.0 ml of a 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.
A hexane solution of the obtained copolymer is precipitated in isopropyl alcohol and sufficiently dried to give a styrene butadiene rubber having a hydroxyl group at the molecular end (styrene content: 20% by mass, weight average molecular weight 18,000, molecular weight distribution). 1.15) was obtained. In addition, the weight average molecular weight was calculated | required by polystyrene conversion using GPC method (Gel Permeation Chromatography).

(Hydrogenation treatment)
120 g of styrene butadiene rubber having a hydroxyl group at the molecular end obtained above was dissolved in 1 L of sufficiently dehydrated and purified hexane, and then nickel naphthenate, triethylaluminum and butadiene prepared in separate containers in advance [1: 3: 3 (molar ratio)] was prepared so that the amount of nickel was 1 mol with respect to 1,000 mol of the butadiene-derived structural unit of the styrene-butadiene rubber. Hydrogen was added under pressure at 2.758 MPa (400 psi) to the sealed reaction vessel, and a hydrogenation reaction was performed at 110 ° C. for 4 hours.
Thereafter, the catalyst residue was extracted and separated with ³ mol / m ³ hydrochloric acid, and further centrifuged to separate the catalyst residue by sedimentation. Then, a hydrogenated styrene butadiene rubber having a hydroxyl group at the molecular end is precipitated in isopropyl alcohol and further sufficiently dried to obtain a hydrogenated styrene butadiene rubber having a hydroxyl group at the molecular end (styrene content 20 mass%, weight average molecular weight). 16,500, hydrogenation rate 98%, molecular weight distribution 1.1) were obtained.
(Modification of molecular ends)
The thus obtained hydrogenated styrene butadiene rubber having a hydroxyl group at the molecular end is dissolved in cyclohexane and stirred at 40 ° C., 2-acryloyloxyethyl isocyanate (“Karenz (registered trademark) AOI”, manufactured by Showa Denko KK). Was slowly added dropwise, and the mixture was further stirred for 4 hours, and then crystals were precipitated in isopropyl alcohol to obtain a terminal-modified hydrogenated styrene butadiene rubber.

<Examples 1-4, Comparative Examples 1-5>
Each component was mixed with the planetary mixer by the compounding quantity (unit: mass part) shown in Table 1, and the photocurable resin composition was obtained. Each evaluation and measurement was performed according to the said method using this photocurable resin composition. The results are shown in Table 1.

* 1: Terminal-modified hydrogenated styrene butadiene rubber obtained in Production Example 1 * 2: Kuraray Co., Ltd., weight average molecular weight = 7,000
* 3: "CN9014", manufactured by Sartomer * 4: isobornyl acrylate, manufactured by Osaka Organic Chemical Industry Co., Ltd. * 5: dicyclopentenyloxyethyl acrylate, manufactured by Hitachi Chemical Co., Ltd. * 6: "Irgacure (registered trademark)" 36P "(BASF)
* 7: "LUCIRIN (registered trademark) TPO" (manufactured by BASF), see the following chemical structural formula * 8: "Irgacure (registered trademark) 184" (manufactured by BASF), refer to the following chemical structural formula * 9: Measurement temperature Changed to 50 ° C.

From Table 1, the photocurable composition of the present invention has a low viscosity at 23 ° C., low moisture permeability, and high electrode corrosion resistance. Furthermore, it can be seen that curing can be performed by ultraviolet irradiation even in an environment where ultraviolet rays having a wavelength of 380 nm or less are blocked.
On the other hand, the photocurable resin composition of Comparative Example 1 does not contain the component (a2) and contains a photopolymerization initiator other than the component (C) specified in the present invention. In the environment where the viscosity is high and the ultraviolet ray having a wavelength of 380 nm or less is blocked, the ultraviolet ray cannot be cured. In Comparative Examples 2 to 4, although the component (a2) was added in addition to the component (a1), and because it contains a photopolymerization initiator other than the component (C) specified in the present invention, In an environment where ultraviolet rays having a wavelength of 380 nm or less were blocked, ultraviolet curing could not be performed. Furthermore, Comparative Example 5 is a case in which the component (B) is not contained, and UV curing was possible in an environment where UV light having a wavelength of 380 nm or less was blocked. However, the viscosity was too high, and “capillary phenomenon. It was a photocurable resin composition in which the method of curing by ultraviolet rays after allowing the sealing material to enter between the films using the method could not be adopted, and the problem of the present invention could not be solved.

  The photocurable resin composition of the present invention is excellent in water vapor barrier properties and electrode corrosion resistance, has a low viscosity, and can be cured in an ultraviolet shielding environment of 380 nm or less. It is useful as a (sealing material), particularly as a sealing material (sealing material) for electronic parts. More specifically, sealing materials for electronic displays such as organic electroluminescent elements and inorganic electroluminescent elements, backlights for electronic devices such as mobile phones, digital video cameras, and PDAs that use LEDs, large displays, and roads It is useful as a sealing material for a light emitting element such as a display unit such as a display and general illumination.

Claims (8)

A rubber (A) containing the terminal-modified hydrogenated conjugated diene-aromatic vinyl copolymer (a1) and / or the terminal-modified hydrogenated conjugated diene polymer (a2),
Reactive diluent (B), and α-aminoacetophenone and / or acylphosphine oxide photopolymerization initiator (C)
A photocurable resin composition comprising:
The content ratio [(A) :( B)] of the component (A) and the component (B) is 10:90 to 90:10 by mass ratio, and the content of the component (C) is the above ( The photocurable resin composition which is 0.01-15 mass parts with respect to a total of 100 mass parts of A) component and the said (B) component.   The component (A) contains the component (a1) and the component (a2), and the mixing ratio [(a1) :( a2)] of the component (a1) and the component (a2) is 10 by mass ratio. The photocurable resin composition of Claim 1 which is: 90-90: 10.   The photocurable resin composition according to claim 1, wherein the component (A) is one of the component (a1) and the component (a2).   The photocurable resin according to claim 1, wherein the component (a1) is a terminal acrylic-modified hydrogenated styrene butadiene rubber, and the component (a2) is a terminal acrylic-modified hydrogenated butadiene rubber. Composition.   The weight average molecular weight of the (a1) component is 2,000 to 40,000, and the weight average molecular weight of the (a2) component is 2,000 to 40,000. Photocurable resin composition.   The photocurable property according to any one of claims 1 to 5, wherein the component (B) is a liquid photopolymerizable monovinyl monomer selected from vinyl esters, (meth) acrylic monomers, N-vinyl monomers, and polythiol compounds. Resin composition.   The photocurable resin composition in any one of Claims 1-6 whose viscosity in 23 degreeC is 0.1-50 Pa.s.   The sealing material which consists of a photocurable resin composition in any one of Claims 1-7.