WO2008032851A1

WO2008032851A1 - Photocurable sealing agent composition and member with sealing layer

Info

Publication number: WO2008032851A1
Application number: PCT/JP2007/068021
Authority: WO
Inventors: Kuniaki Nakajima
Original assignee: Three Bond Co., Ltd.
Priority date: 2006-09-15
Filing date: 2007-09-11
Publication date: 2008-03-20
Also published as: JP2008069302A; TW200831650A

Abstract

Disclosed is a photocurable sealing agent composition containing (A) one or more bifunctional (meth)acrylates having a (meth)acryloyl group at both ends of an optionally branched aliphatic hydrocarbon wherein the main chain has 3-15 carbon atoms, (B) one or more monofunctional (meth)acrylates having a (meth)acryloyl group at one end of an optionally branched chain alkyl skeleton having 6-20 carbon atoms, (C) a styrene-isobutylene block copolymer, (D) a photopolymerization initiator and (E) a silica powder. Also disclosed is a member such as electronic component case which has a sealing layer obtained by applying the photocurable sealing agent composition over the member and irradiating the composition with light.

Description

Specification

Photocurable sealing agent composition and member with a Zeal layer

Technical field

The present invention relates to a photocurable sealant composition and a member having a seal layer using the photocurable sealant composition, and particularly includes an electronic circuit element such as a hard disk drive and an electronic component. The present invention relates to a sealing technique for an electronic component case. Background art

Sealing materials for sealing are used in electronic component cases that contain electronic circuit elements and electronic components, such as hard disk drives, to prevent the entry of dust and the like. As a sealing material, methods such as punching and bonding rubber sheets have been used, but the mass productivity is low, and a new mold is required to change the design, resulting in a low degree of design freedom.

In recent years, electronic components have been miniaturized, and it has become necessary to integrate and combine components. In addition, in order to improve reliability, improvements in sealing functions such as higher moisture permeability have been demanded. In order to satisfy these requirements, a sealing method (CIPG) has been adopted in which a sealing layer is formed by curing a sealing agent composition on a member, replacing the conventional rubber packing. .

As a sealing method, a method (FIPG) is generally known in which a liquid sealant is held between members to be sealed and then the sealant is cured by an appropriate method. When FIPG is used to seal electronic device parts such as hard disk drives, by-products and unreacted gases generated during the curing of the sealant stay inside the sealed parts, which are used in electronic circuit elements and electronic components. May be adversely affected. Therefore, in the sealing of electronic equipment members, C I P G G is more preferable than F I P G in terms of workability and reliability. As a method for curing the sealing agent, a method of applying energy such as heat or light is known. However, it has little effect on electronic circuit elements and electronic parts, has excellent productivity, and the sealing agent during curing. However, photocuring is preferred as a method of easily maintaining the shape.

Conventional photocurable sealant compositions include unsaturated polyester resins and epoxy resins. The acrylic resin such as cis (meth) acrylate and urethane (meth) acrylate is added with a photopolymerization initiator, or the epoxy resin is added with a photopolymerization initiator. In particular, those using urethane (meth) acrylate are easy to impart flexibility to the cured product, and therefore have been proposed to be used as a photo-curable sealing agent composition (Japanese Patent Laid-Open No. 20 0 5-1 3 9 4 6 No. 1). The photo-curing sealant composition using urethane (meth) acrylate is excellent in mass production, freedom of design, elongation of cured product, etc., and is excellent as a sealing material for the purpose of dust prevention. It is. On the other hand, the moisture permeability was not sufficiently high, and an excellent moisture-resistant sealing function could not be realized in the electronic component case.

As a photocurable sealant composition having a high moisture resistance, a composition using methacryloyl-modified liquid polyisoprene, an acrylate monomer, etc. has been proposed (Japanese Patent Laid-Open No. 2 0 0 5-6 0 4 6 5 Publication). However, this photo-curable sealant composition does not use a block copolymer, which is a flexibility-imparting component, and the methacrylyl-modified liquid polyisoprene is not difunctional at the end, so the cured product is There is a tendency to become hard in environments where heat is applied. For this reason, it was impossible to follow the movement of the member due to impact or temperature cycle, and a highly reliable sealing function could not be realized. Further, as a photocurable sealing agent composition having excellent moisture resistance, a sealing agent composition comprising an isoprene block and another block copolymer as a main component (Japanese Patent Laid-Open No. 5-29500). No. 3), gasket materials (Japanese Patent Laid-Open No. 1-11 3 2 3 0 69) and the like have been proposed. In order to form a seal layer, these require a process of forming a seal layer with an extruder, injection molding machine, etc., and then affixing to an applicable member. This is a problem in terms of mass productivity and design flexibility. Hot.

Furthermore, a photocurable sealing agent composition using a styrene-isobutylene-styrene block copolymer and a chain aliphatic monofunctional (meth) acrylate having 18 to 25 carbon atoms has also been proposed (JP-A-2). 0 0 5— 1 5 4 5 2 8). However, if the (meth) alkylene is monofunctional and the chain aliphatic chain has such a long carbon chain, a dense network is difficult to form when cured, improving the elastic element. I can't. As a result, the sealant composition is cured on the member and sealed. It could not be used for the purpose of forming a layer (CI PG).

Disclosure of the invention

Object of the invention

The object of the present invention is to solve the above-mentioned problems, and in particular, it has high moisture resistance, and a CI PG seal layer can be formed by applying a sealant composition onto a component and irradiating it with light. It is another object of the present invention to provide a highly reliable photo-curable sealing agent composition and a member with a sealing layer, which are excellent in design freedom and in which a seal layer can follow the movement of the member. Summary of invention

The present invention, first,

(A) General formula (1)

R ³ R ²

I I

H ₂ C = CC-0-R ¹ -0-CC = CH ₂ (1)

II II

o o

(Where R ¹ is a divalent aliphatic hydrocarbon group having 3 to 15 carbon atoms in the main chain, and R ² and R ³ are each independently a hydrogen atom or a methyl group)

At least one bifunctional (meth) acrylate, represented by

(B) General formula

R ⁵

I

R ⁴ -OCC = CH ₂ (2)

II

o

(Where R ⁴ is an alkyl group having 6 to 20 carbon atoms, and R ⁵ is a hydrogen atom or a methyl group)

At least one monofunctional (meth) acrylate, represented by

A photocurable sealant composition comprising (C) a styrene-isobutylene block copolymer, (D) a photopolymerization initiator, and (E) silica powder.

In the above, the amount of each component is based on the total weight of the composition. ~ 20 wt%, (B) component 40 to 80 wt%, (C) component 10 to 50 wt%, (D) component 0.1 to L: 0 wt%, and (E ) It is preferred that the component is 0. As the component (C), a triblock-structure styrene monoisoptylene-styrene copolymer is particularly preferable.

Secondly, the present invention is a member having a sealing layer formed by applying the above-mentioned photocurable sealing agent composition and curing it by irradiating light.

In the above, the member is preferably an electronic component housing such as a hard disk drive.

The invention's effect

The photocurable sealant composition of the present invention is a seal for an electronic component case containing an electronic circuit element such as a hard disk drive or an electronic component case, and the like, by sealing the sealant composition on the member. By adopting the sealing method of forming a layer, mass productivity and design freedom are high, and because it has excellent elasticity, it has good follow-up to the movement of members, and is particularly suitable for CIPG applications. Therefore, it is possible to solve the problem of outgas that occurs, and to form a sealing layer having excellent moisture resistance.

Embodiment of the Invention

Hereinafter, the photocurable sealant composition of the present invention will be described in detail.

The photocurable sealant composition of the present invention comprises (A) a bifunctional (meth) acrylate and (B) a monofunctional (meth) acrylate that reacts with light to generate radicals. (D) A photopolymerization initiator Based on the polymerization reaction. “(Meth) acrylate” is a general term for acrylate and methacrylate.

The bifunctional (meth) acrylate of the component (A) of the present invention is used for the purpose of improving the adhesive strength and heat resistance of the photocurable sealing agent composition. Bifunctional is a compound having two (meth) acryloyl groups contributing to the reaction in the molecule.

Here, the component (A) of the present invention will be described. The bifunctional (meth) acrylate of the component (A) is a compound represented by the general formula (1), and R ¹ is a divalent aliphatic hydrocarbon group having 3 to 15 carbon atoms in the main chain. As long as it has a branched chain It may also have an unsaturated bond (double bond) in addition to the saturated bond. R ¹ is preferably an alkylene group having 3 to 15 carbon atoms in the main chain. As the bifunctional (meth) acrylate of component (A), 1,3-butanediol di (meth) acrylate, 2-ethyl-2-butylpropanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate , Neopentyl alcoholic (meth) acrylate, 1,6-hexanediol (meth) acrylate, 3-methyl-1,5-pentanedio ^ / di (meth) acrylate, 1,9-nonanediol Di (meth) acrylate, 2,4-jetyl_ 1,5-pentanediol di (meth) acrylate, 2-methyl-1,8-octanediol di (meth) acrylate, 1, 10 0-decanediol di (Meth) acrylate, 2_ethyl-2-butylpropanediol (meth) acrylate, 1, 1 2—dodecanedi (meth) alk Rate, 1, 1 4 one Pentadekanji (meth) Akurireto, 1, 1 5- Pentadekanji (meth) § acrylate and the like, Ru can be used to select a single or plurality of types of these. These bifunctional (meth) acrylates need to have 3 to 15 carbon atoms in the main chain hydrocarbon in order not to impair the adhesive strength and heat resistance of the cured product. The total number of carbon atoms in R ¹ is not particularly limited, but is preferably 3-20. The addition amount is preferably 0.1 to 20% by weight, and more preferably 0.5 to 10% by weight.

The monofunctional (meth) acrylate of the component (B) of the present invention is a compound represented by the general formula (2), and is used for the purpose of enhancing the flexibility and curability of the photocurable sealing agent composition. The R ⁴ is not particularly limited as long as it is an alkyl group having 6 to 20 carbon atoms, and may have a branched chain. Specifically, 2-ethylhexyl (meth) acrylate, isoamyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isodecyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) ) Acrylate, isomyristyl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, icosanyl (meth) acrylate, and the like. These can be used singly or in combination so that the flexibility of the cured product meets the purpose. In addition, if the carbon number of the alkyl group of the component (B) becomes too small, the flexibility of the cured product decreases or the adhesiveness of the surface increases, making it difficult to use as a sealing agent. If the value is too large, the curability is deteriorated and the productivity is lowered. Monofunctional (meth) acrylates having an alkyl group with 6 to 20 carbon atoms are preferred, and those with 8 to 18 carbon atoms are preferred in order to give moderate flexibility to the cured product and excellent curability to the uncured product. Is more preferable. Further, the addition amount is preferably 40 to 80% by weight, and more preferably 50 to 70% by weight. If the added amount is 40% by weight or less, the cured product becomes too hard, and if it is 80% by weight or more, it becomes too soft when used in a high temperature environment, and the sealing performance is deteriorated.

The styrene-isobutylene block copolymer of component (C) of the present invention is used for the purpose of imparting moisture resistance and flexibility to the photocurable sealant composition. The component (C) may be a block copolymer having a polystyrene block composed of a styrene monomer and a polyisobutylene block composed of an isobutylene monomer. However, a styrene-isobutylene-styrene triblock having a triploc structure may be used. A polymer is more preferred. In the present invention, the polymer preferably has a styrene block content of 10 to 40% by weight, more preferably 15 to 35% by weight. The amount of the component (C) is preferably 10 to 50% by weight, more preferably 20 to 40% by weight. If the amount added is less than 10% by weight, sufficient moisture permeation resistance cannot be imparted to the composition, and if it exceeds 50% by weight, it will be sufficient in the components (A) and (B). Incompatible or dispersible. Commercially available products of the triblock copolymer include SIBSTAR 072 T and SIBSTARR1 0 2 T (manufactured by Kane force Co., Ltd.).

By combining the above-mentioned (Α) bifunctional (meth) acrylate, (Β) monofunctional (meth) acrylate, and (C) styrene-isobutylene block copolymer, the cured product of the photocurable sealant composition is It can have excellent elasticity, and it exhibits high sealing performance in CIPG applications. It should be noted that if the amount of each component deviates significantly from the amount described above, it will be difficult to obtain the required inertia.

The photopolymerization initiator of component (D) of the present invention is used for the purpose of curing the photocurable sealant composition. The component (D) may be an initiator that generates radicals by light irradiation. If it is not specifically limited, a well-known thing can be used. For example, dimethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, methoxyacetophenone, acetophenone, propiophenone, benzophenone, xanthol, fluorein, benzaldehyde, anthraquinone, triphenylamine, 2, 2-dimethoxy-1 , 2-Diphenylethane 1-one, carbazole, 2-hydroxy-2 _Methylphenylpropane 1-one, 1- [4 1- (2-hydroxyethyl) phenyl] — 2-hydroxy-1-2-methyl-1 —Propane 1-one, 2-hydroxyl— 1— {4— [4— (2 -Hydroxy-2-methylpropionyl) benzyl] phenyl} — 2-Methylpropane 1 1-one, 2-benzyl — 2—Dimethylamino 1-- (4-morpholinophenyl) 1 1-butanone, bis (2, 4,6-trimethylbenzoyl) phenylphosphine oxide, 2,4,6-trimethyl benzoyldiphenylphosphine oxide, 2-hydroxy-1,2-methyl-1, 1-methylvinyl) phenyl] propanone oligomer, 3-methylacetophenone, 4-methylacetophenone, 3-pentylasephenone, 4-methoxyacetophenone, 3-promoacetophenone, p-diacetyl Benzene, 3-Methoxybenzophenone, 4-arylacetophenone, 4-Methylbenzophenone, 4 _Chromium 1-Benzylbenzophenone, 3-Chloroxane] ^ one, 3, 9— Dichloroxanthone, 3-chloro-8-nonylxanthone, benzoyl, benzoin methyl ether, benzoin butyl ether, bis (4-dimethylaminophenyl) ) Ketone, benzyl methoxy ketal, 2 Kurorochiokisa 1 ^ Ichin the like. The addition amount is preferably in the range of 0.1 to 10% by weight, but more preferably in the range of 0.1 to 5% by weight.

The silica powder of component (E) of the present invention is used to give thixotropic properties to the liquid composition before curing. In order to cure the photo-curable sealant composition on a member to form a seal layer, it is necessary to maintain the shape until it is applied and cured at a certain height or higher. To achieve this, silica powder is added to achieve this. This silica powder has a surface treatment with an average primary particle diameter of 1 to 100 nm, preferably 5 to 50 nm, and has been surface-treated or not surface-treated. Either can be used Is possible. Specific examples of the surface-treated products include alumina-containing silica and titanium oxide that coexist with chlorides such as titanium chloride, aluminum chloride, and iron chloride when hydrolyzing silicon tetrachloride in hydrogen peroxide. Examples thereof include finely divided silica such as silica containing iron, silica containing iron oxide, and the like, and those obtained by hydrophobizing the surface of hydrophilic finely divided silica are particularly preferable. Hydrophobic fine-powdered silica is a surface of normal hydrophilic fine-powdered silica. Alkyl, aryl, aralkyl silane coupling agents having a hydrophobic group such as n-octyltrialkoxysilane, dimethyldichlorosilane, hexamethyldi It is obtained by treating with a silylating agent such as silazane, a polydimethylsiloxane having a hydroxyl group at the terminal, a higher alcohol such as stearyl alcohol, or a higher fatty acid such as stearic acid. These finely divided silicas may be used alone or in combination of two or more. The addition amount is preferably 0.1 to 30% by weight, and more preferably 1.0 to 15% by weight.

Other inorganic fillers other than silica powder, such as calcium carbonate and carbon black, have poor compatibility with the components (A) and (B) in the present invention, and are sufficiently contained in the components (A) and (B). Thixotropy cannot be expressed because it does not disperse. In addition, since the curable composition of the present invention achieves curing by irradiation with light, if a silica powder having an extremely high concealing property is selected, the curability may be hindered.

In addition to the components (A) to (E), other components can be added to the photocurable sealant composition of the present invention as necessary. Examples of the component to be added include a stabilizer, a colorant, a thermal polymerization initiator, an adhesion promoter, an anti-aging agent, and a dispersion aid. In order to improve the adhesiveness of the photocurable sealing agent composition of the present invention, it is particularly preferable to add an adhesion assistant. As the adhesion aid, a silane coupling agent, a titanium coupling agent, and the like can be applied, but a silane-powered coating agent is preferable from the viewpoint of storage stability and compatibility of the composition. Specifically, a silane coupling agent having at least one functional group selected from an epoxy group, a (meth) acrylic group, a biel group, and a strong rubamate group in the molecule and a silicon atom-bonded hydroxyl group is preferable. .

The member having the seal layer of the present invention is formed by applying the sealant composition on the member and then curing it by light irradiation. Application can be done by any method, The light source can be a high pressure mercury lamp, an ultra high pressure mercury lamp, a metal halide lamp, a mercury xenon lamp, a xenon lamp, or an LED. The irradiation ambient temperature is usually in the range of 10 to 200 ° C, and the wavelength of the irradiation light is (D) the absorption wavelength band of the photopolymerization initiator.

Example

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. The evaluation contents of the sealant composition are two items, ie, moisture permeability of the cured product, water vapor permeability coefficient and elasticity as elongation. The smaller the value of the water vapor transmission coefficient, the better the moisture resistance, and it is preferably in the range of 0 to 20 g / m ² '24 h 'atm. The larger the numerical value of elongation, the better the followability at the time of sealing, and it is preferably 90% by weight or more. The elongation and water vapor transmission coefficient were measured by the following methods.

[Growth rate]

Form forms a uniform film-shaped 1 mm thick light-curing sealant compositions of the present invention prior to curing, their respective Thereto light 3000 m J cm ² each side using a high-pressure mercury lamp It hardened | cured by irradiating both surfaces and the sheet-like hardened | cured material was obtained. This was punched out with a No. 3 type dumbbell specified in JISK 6251 to produce a dumbbell-shaped specimen for tensile testing. Using this test piece, the elongation at break (elongation rate) of the cured product of the sealant composition of the present invention was measured by carrying out a tensile test specified in JISK 6251 using a universal tensile tester. The tensile speed of the universal tensile testing machine was 50 Omm per minute, and the stretched part was measured with a vernier caliper specified by JISB 7503 or a caliper with equivalent or better performance. The median value obtained when the test was performed three times was adopted as the elongation value.

[Water vapor transmission coefficient]

The photocurable sealant composition of the present invention before curing is formed into a uniform film having a thickness of 0.5 mm, and 300 Om J / cm ² of light is applied to each side using a high-pressure mercury lamp. Each was cured by irradiation on both sides to obtain a sheet-like cured product. This sheet was cut into a 15.2 cm ² circular test piece, and a differential pressure vapor permeability measurement device was installed. The water vapor permeation coefficient was measured using a device (GTR-30XA3B, manufactured by GTR Tech).

Example 1

2-Acetyl-2-butylpropanediol diacrylate as component (A), isononyl acrylate as component (B), styrene-isobutylene-styrene copolymer with triblock structure as component (C) (styrene content) 23% by weight: Trade name SI BSTAR 072 T manufactured by Kane force Co., Ltd.) (D) Component 2-hydroxy-2-methyl- 1 1 [4-1 (1-methyl vinyl) phenyl] propane oligomer (trade name ESACURE KIP 150 Lamb erti), and (E) component untreated surface-treated fumed silica (trade name: Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) was used. (A) (B) (C) (D) After stirring the components to 60 ° C to obtain a uniform liquid, the (E) component is mixed with a planetary mixer, and a sealant composition is obtained. Got. The amount of each compound is shown in Table 1 in parts by weight. Using a high-pressure mercury lamp

A cured product was produced by irradiating 300 OmJZcm ² of light on each side, and the water vapor transmission coefficient and the elongation were measured. As shown in Table 1, all obtained good results.

Example 2

(A) R ¹ is a bifunctional acrylate with a main chain of 5 carbon atoms and side chains (2,

4_Jetyl 1,5-pentenediol diacrylate) was used in the same procedure as in Example 1 to obtain a sealant composition. A cured product was prepared and measured in the same manner as in Example 1. As shown in Table 1, both the water vapor transmission coefficient and the elongation were good.

Example 3

(A) The sealing agent composition was the same as in Example 1, except that bifunctional acrylate (1,12-dodecanediol diacrylate) in which R ¹ is an alkylene group having 12 carbon atoms was used as component (A). Got. A cured product was prepared and measured in the same manner as in Example 1. As shown in Table 1, both the water vapor transmission coefficient and the elongation were good.

Example 4 A sealant composition was obtained in the same procedure as in Example 1 except that a mixture of Tisooctylacrylate and isostearylacrylate was used as the component (B). A cured product was prepared and measured in the same manner as in Example 1. As shown in Table 1, both the water vapor transmission coefficient and the elongation were good.

Example 5

(C) Similar to Example 1 except that a triblock styrene-isobutylene-styrene block copolymer (styrene content: 15% by weight: manufactured by SIBSTAR 1 0 2 T Kane force Co., Ltd.) was used as the component. A sealant composition was obtained by the procedure. A cured product was prepared and measured in the same manner as in Example 1. As shown in Table 1, both the water vapor transmission coefficient and the elongation were good.

Example 6

A procedure similar to that of Example 1 except that a styrene-isobutylene block copolymer having a diblock structure (styrene content: 20% by weight, number average molecular weight: about 30, 00) was used as the component (C). A sealant composition was obtained. A cured product was prepared and measured in the same manner as in Example 1. As shown in Table 1, both the water vapor transmission coefficient and the elongation were good.

Comparative Example 1

(A) A sealant composition was obtained in the same procedure as in Example 1 except that the component was not used. An attempt was made to produce a cured product in the same manner as in Example 1, but the evaluation was not possible because the cured film was insufficient and a cured film could not be formed.

Comparative Example 2

(A) A sealant composition was obtained in the same procedure as in Example 1, except that trimethylolpropane triacrylate was used instead of the component. When a cured product was prepared and measured in the same manner as in Example 1, neither the elongation rate nor the water vapor transmission coefficient was satisfactory. Comparative Example 3

A sealant composition was obtained in the same procedure as in Example 1, except that 1,16-hexadecanediol diacrylate was used in place of the component (A). When a cured product was prepared and measured in the same manner as in Example 1, neither the elongation rate nor the water vapor transmission coefficient was satisfactory. Comparative Example 4

A sealant composition was obtained in the same procedure as in Example 1, except that PO modified bisphenol A diacrylate was used instead of the component (A). When a cured product was prepared and measured in the same manner as in Example 1, neither the elongation rate nor the water vapor transmission coefficient was satisfactory. Comparative Example 5

(A) A sealant composition was obtained in the same procedure as in Example 1, except that ethylene glycol diacrylate was used instead of the component. When a cured product was prepared and measured in the same manner as in Example 1, neither the elongation rate nor the water vapor transmission coefficient was satisfactory.

Comparative Example 6

A sealant composition was obtained in the same procedure as in Example 1, except that 1,5-pentanediol acrylate was used in place of the component (B). When a cured product was prepared and measured in the same manner as in Example 1, the cured product became very hard, and a test piece could not be prepared and could not be measured.

Comparative Example 7

A sealant composition was obtained in the same procedure as in Example 1 except that pentyl acrylate was used in place of the component (B). When a cured product was prepared and measured in the same manner as in Example 1, neither the elongation rate nor the water vapor transmission coefficient was satisfactory.

Comparative Example 8

(B) A sealant composition was prepared in the same procedure as in Example 1 except that paracumylphenoloxyethylene glycolate was used instead of the component, and the composition did not become a uniform liquid. The agent could not be obtained.

Comparative Example 9

A sealant composition was obtained in the same procedure as in Example 1, except that isoponyl acrylate was used in place of the component (B). When a hard material was prepared and measured in the same manner as in Example 1, the cured product became very hard, and a test piece could not be prepared and could not be measured. Comparative Example 1 0

(B) A sealant composition was obtained in the same manner as in Example 1 except that henecosanyl acrylate was used in place of the component. A cured product was prepared and measured in the same manner as in Example 1. B) Both the elongation and water vapor transmission coefficient were not satisfactory.

Comparative Example 1 1

A sealant composition was obtained in the same procedure as in Example 1, except that methacryloylated liquid polyisoprene (UC-2203, manufactured by Kuraray Co., Ltd.) was used instead of the component (C). When a cured product was prepared and measured in the same manner as in Example 1, as shown in Table 1, although the water vapor transmission coefficient was satisfactory, the elongation was small and it was not usable as a CIPG sealant.

Comparative Example 1 2

A sealant composition was obtained in the same manner as in Example 1 except that styrene-ethylene butylene-styrene block copolymer (manufactured by Kraton G 1 7 2 6 Kraton Polymer Co., Ltd.) was used instead of the component (C). It was. When a cured product was prepared and measured in the same manner as in Example 1, good results were obtained for the elongation as shown in Table 1, but the water vapor transmission coefficient was not satisfactory.

Comparative Example 1 3

(C) A sealant composition was obtained in the same procedure as in Example 1, except that a styrene-ethylene / propylene-styrene block copolymer (manufactured by Kuraray Co., Ltd.) was used instead of the component. . A cured product was prepared and measured in the same manner as in Example 1. As shown in Table 1, although an excellent result was obtained with respect to the elongation, the water vapor transmission coefficient was not satisfactory.

Comparative Example 1 4

(C) A sealant composition was obtained in the same procedure as in Example 1 except that polyurethane acrylate (purple UV-3700 B manufactured by Nippon Gosei Chemical Industry Co., Ltd.) was used instead of component (C). . A cured product was prepared and measured in the same manner as in Example 1. As shown in Table 1, neither the elongation rate nor the water vapor transmission coefficient was satisfactory.

Reference example

A sealant composition was obtained in the same procedure as in Example 1, except that the component (E) was not used. It was confirmed that this sealant composition was inadequate for CIPG use because its shape retention was poor and the bead shape could not be retained after application. table 1

Example

1 2 3 4 5 6

2-Ethyl-2-butylpropane

5 5 5 5 Diol diatalylate

A 2—Jetyl 1,5—Pentane

Five

Diol diatalylate

1,12—Dodecanediol acrylate 5

Isononyl acrylate 95 95 95 95 95

B Isooctyl acrylate 50

Isostearyl acrylate 45

SIBSTAR 072T 35 35 35 35

C SIBSTAR 102T 35

Styrene monoisobutylene copolymer 35

D ESACURE KIP150 2 2 2 2 2 2

E AEROSIL 200 6 6 6 6 6 6 Water vapor transmission coefficient (gZm ² · 24h · atm) 15 16 15 14 17 15 Elongation (%) 100 120 100 90 160 90

Table 2

Industrial applicability

The photocurable sealant composition and the member with the sealant obtained from the present invention have an electronic component housing containing an electronic circuit element such as an eight-sided disk or an electronic component because of its excellent moisture permeation resistance and elasticity. It is useful as a moisture-permeable sealant for body seals and other members that require moisture permeability.

Claims

The scope of the claims

1. (A) General formula (1)

R ³ R ²

I I

H ₂ C = CC-0-R ¹ -0-CC = CH ₂ (1)

II II

o o

At least one bifunctional (meth) acrylate, represented by

(B) — General formula

R ⁵

I

R ⁴ -0 ~ CC = CH ₂ (2)

II

o

At least one monofunctional (meth) acrylate, represented by

A photocurable sealant composition comprising: (C) a styrene-isobutylene block copolymer, (D) a photopolymerization initiator, and (E) siri flour.

2. 0.1-20% by weight of component (A), 40-80% by weight of component (B), 10-50% by weight of component (C), 0.1-10% by weight of component (D) The photocurable sealing agent composition according to claim 1, comprising 0.1 to 30% by weight of the component (E).

3. The photocurable sealant composition according to claim 1 or 2, wherein the component (C) is a styrene isobutylene-styrene copolymer having a triblock structure.

4. A member having a seal layer formed by applying the photocurable sealant composition according to any one of claims 1 to 3 and curing it by irradiation with light.

5. The member according to claim 4, wherein the member is an electronic component casing.

6. The member according to claim 5, wherein the electronic component housing is a case of a hard disk drive.