阅读说明：本技术 室温下可固化的有机硅橡胶组合物及其用途 (Room temperature curable silicone rubber composition and use thereof ) 是由 小玉春美 大西正之 于 2014-12-25 设计创作，主要内容包括：本发明提供了一种室温下可固化的有机硅橡胶组合物,所述组合物表现出与固化过程中所接触基底的良好粘附性,并且能够抑制渗油发生。所述问题通过包含以下组分的室温下可固化的有机硅橡胶组合物得到了解决：(A)混合物,所述混合物包含(A1)分子内具有至少两个特定含烷氧基甲硅烷基的基团的有机聚硅氧烷和(A2)分子内具有一个特定含烷氧基甲硅烷基的基团的有机聚硅氧烷；(B)缺少羟基和烷氧基的有机聚硅氧烷；(C)烷氧基硅烷；以及(D)缩合反应的催化剂。(The present invention provides a room-temperature curable silicone rubber composition that exhibits good adhesion to a substrate in contact during curing and is capable of suppressing the occurrence of oil bleeding. The problem is solved by a room temperature curable silicone rubber composition comprising: (A) a mixture comprising (a1) an organopolysiloxane having at least two specific alkoxysilyl-containing groups in the molecule and (a2) an organopolysiloxane having one specific alkoxysilyl-containing group in the molecule; (B) an organopolysiloxane lacking hydroxyl and alkoxy groups; (C) an alkoxysilane; and (D) a catalyst for the condensation reaction.)

1. A room-temperature curable silicone rubber composition comprising: (A) a mixture comprising the following components (a1) and (a 2):

(A1) an organopolysiloxane having at least two alkoxysilyl-containing groups on silicon atoms in the molecular chain of each molecule, the alkoxysilyl-containing groups being represented by the following general formula:

(wherein R is¹Are identical or different monovalent hydrocarbon radicals free of aliphatic unsaturation, R²Is alkyl, R³Are the same or different alkylene groups, a is an integer of 0 to 2, p is an integer of 1 to 50);

(A2) an organopolysiloxane having one of the above-described alkoxysilyl group-containing groups in each molecule;

(B) an organopolysiloxane lacking hydroxyl groups and alkoxy groups on silicon atoms in the molecular chain;

(C) an alkoxysilane represented by the general formula:

R⁴ _bSi(OR⁵)_(4-b)

(wherein R is⁴Is a monovalent hydrocarbon radical, R⁵Is an alkyl group, and b is 0 to 2) or a partially hydrolyzed condensate thereof; and

(D) a condensation reaction catalyst.

2. The room-temperature curable silicone rubber composition according to claim 1, wherein the mass ratio of the component (a1) to the component (a2) in the component (a) is from 1:10 to 10: 1.

3. The room-temperature curable silicone rubber composition according to claim 1 or claim 2, wherein the viscosity of the component (a) as a whole at 25 ℃ is in the range of 100 to 1000000mPa s.

4. The room-temperature curable silicone rubber composition according to any one of claim 1 to claim 3, wherein the component (A1) is a linear organopolysiloxane having alkoxysilyl-containing groups on silicon atoms at both molecular ends, and the component (A2) is a linear organopolysiloxane having alkoxysilyl-containing groups on silicon atoms at one molecular end.

5. The room-temperature curable silicone rubber composition according to any one of claim 1 to claim 4, wherein the alkoxysilyl group-containing group in the component (A) is a group represented by the formula:

6. the room-temperature curable silicone rubber composition according to any one of claim 1 to claim 5, wherein the viscosity of the component (B) at 25 ℃ is in the range of 10mPa s to 1000000mPa s.

7. The room-temperature curable silicone rubber composition according to any one of claim 1 to claim 6, wherein the component (C) is methyltrimethoxysilane.

8. The room-temperature curable silicone rubber composition according to any one of claim 1 to claim 7, which contains 1 to 100 parts by mass of the component (B), 0.5 to 30 parts by mass of the component (C), and 0.1 to 10 parts by mass of the component (D), relative to 100 parts by mass of the component (a).

9. The room-temperature curable silicone rubber composition according to any one of claim 1 to claim 8, further comprising (E) an adhesion promoter.

10. The room-temperature curable silicone rubber composition according to claim 9, wherein the component (E) is at least one type of tackifier selected from the group consisting of: an epoxy group-containing alkoxysilane, an acrylic group-containing alkoxysilane, an amino group-containing alkoxysilane, and a reaction mixture of an epoxy group-containing alkoxysilane and an amino group-containing alkoxysilane.

11. The room-temperature curable silicone rubber composition according to any one of claim 1 to claim 10, further comprising (F) a reinforcing filler.

12. The room-temperature curable silicone rubber composition according to claim 11, wherein the component (F) is at least one type of reinforcing filler selected from the group consisting of: fumed silica fine powder, precipitated silica fine powder, calcined silica fine powder, and fumed titanium dioxide fine powder.

13. A silicone rubber cured product obtained by curing the room-temperature-curable silicone rubber composition described in any one of claim 1 to claim 12.

14. An electronic device in which the silicone rubber cured product described in claim 13 is provided.

Technical Field

The present invention relates to a room-temperature curable silicone rubber composition that cures at room temperature by contact with moisture in the air, a silicone rubber cured product obtained by curing the room-temperature curable silicone rubber composition, and an electronic device having the silicone rubber cured product. The present invention claims priority from japanese patent application No.2013-272670, filed on 27.12.2013, the contents of which are incorporated herein by reference.

Background

A room-temperature curable silicone rubber composition composed of an organopolysiloxane having at least two alkoxysilyl group-containing groups per molecule, an alkoxysilane, and an organotitanium compound is cured at room temperature by contact with moisture in the air (see patent documents 1 to 4). Such room temperature curable silicone rubber compositions are useful, for example, in sealants, adhesives, and as moisture resistant coating agents for electrical circuits or electrodes by curing in contact with such circuits or electrodes.

However, the room-temperature curable silicone rubber compositions as described in patent documents 1 to 4 have a problem that their adhesion to a substrate is insufficient.

Reference list

Patent document

Patent document 1: japanese unexamined patent application publication No.2006-22277A

Patent document 2: japanese unexamined patent application publication No.2006-22278A

Patent document 3: japanese unexamined patent application publication No.2007-231172A

Patent document 4: japanese unexamined patent application publication No.2012-219113A

Disclosure of Invention

Technical problem

An object of the present invention is to provide a room-temperature-curable silicone rubber composition that cures at room temperature by contact with moisture in the air to form a silicone rubber cured product that exhibits good adhesion to a substrate contacted during curing and is capable of suppressing the occurrence of oil bleeding.

Solution to the problem

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a room-temperature curable silicone rubber composition comprising: (A) a mixture comprising (a1) an organopolysiloxane having at least two specific alkoxysilyl-containing groups per molecule on silicon atoms in the molecular chain, and (a2) an organopolysiloxane having one specific alkoxysilyl-containing group per molecule on silicon atoms in the molecular chain; (B) an organopolysiloxane lacking hydroxyl groups and alkoxy groups on silicon atoms in the molecular chain; (C) an alkoxysilane or a partially hydrolyzed condensate thereof; and (D) a catalyst for condensation reaction, and they thereby achieve the present invention.

Specifically, the room-temperature curable silicone rubber composition of the present invention comprises:

(A) a mixture comprising the following components (a1) and (a 2):

(A1) an organopolysiloxane having at least two alkoxysilyl-containing groups on silicon atoms in the molecular chain of each molecule, the alkoxysilyl-containing groups being represented by the following general formula:

(wherein R is¹Are identical or different monovalent hydrocarbon radicals free of aliphatic unsaturation, R²Is alkyl, R³Are the same or different alkylene groups, a is an integer of 0 to 2, p is an integer of 1 to 50);

(A2) an organopolysiloxane having one of the above-described alkoxysilyl group-containing groups in each molecule;

(B) an organopolysiloxane lacking hydroxyl groups and alkoxy groups on silicon atoms in the molecular chain;

(C) an alkoxysilane represented by the general formula:

R⁴ _bSi(OR⁵)_(4-b)

(wherein R is⁴Is a monovalent hydrocarbon radical, R⁵Is alkyl, b is 0 to 2)

Or a partially hydrolyzed condensate thereof; and

(D) a condensation reaction catalyst.

More advantageously, the mass ratio of component (a1) to component (a2) in component (a) is from 1:9 to 9: 1.

More advantageously, the viscosity of component (A) as a whole at 25 ℃ is in the range of from 100 mPas to 1,000,000 mPas.

Component (a1) is preferably a linear organopolysiloxane having alkoxysilyl-containing groups on silicon atoms at both molecular terminals, and component (a2) is preferably a linear organopolysiloxane having alkoxysilyl-containing groups on silicon atoms at one molecular terminal.

The alkoxysilyl group-containing group in component (a) is preferably a group represented by the following formula:

preferably, the viscosity of component (B) at 25 ℃ is in the range of 10 mPas to 1,000,000 mPas.

Preferably, component (C) is methyltrimethoxysilane.

The room-temperature curable silicone rubber composition of the present invention preferably contains 1 to 100 parts by mass of component (B), 0.5 to 30 parts by mass of component (C), and 0.1 to 10 parts by mass of component (D) with respect to 100 parts by mass of component (a).

The room-temperature curable silicone rubber composition of the present invention also preferably contains (E) an adhesion promoter.

Preferably, component (E) is selected from the group consisting of epoxy group-containing alkoxysilanes, acrylic group-containing alkoxysilanes, amino group-containing alkoxysilanes, and reaction mixtures of epoxy group-containing alkoxysilanes and amino group-containing alkoxysilanes.

The room-temperature curable silicone rubber composition of the present invention also preferably contains (F) a reinforcing filler.

Preferably, component (F) is selected from the group consisting of fumed silica fine powder, precipitated silica fine powder, fumed silica fine powder, and fumed titanium dioxide fine powder.

The present invention also relates to a silicone rubber cured product obtained by curing the room-temperature curable silicone rubber composition of the present invention described above.

The invention also relates to electronic equipment provided with the organic silicon rubber cured product.

Advantageous effects of the invention

The room-temperature curable silicone rubber composition according to the invention cures at room temperature by contact with moisture in the air, and can form a silicone rubber cured product that exhibits good adhesion to a substrate contacted during curing and is capable of suppressing the occurrence of oil bleeding (oil component leakage).

The silicone rubber cured product according to the present invention also exhibits good adhesion to a substrate, and is capable of suppressing the occurrence of oil bleeding. Further, the electronic device according to the present invention has excellent reliability because the above-mentioned silicone rubber cured product exhibits good adhesion to a substrate and is capable of suppressing the occurrence of oil bleeding.

Detailed Description

<Room temperature curable silicone rubber composition>

The room-temperature curable silicone rubber composition according to the present invention contains the above-described component (a) to component (D). The room-temperature-curable silicone rubber composition, which cures at room temperature by exposure to moisture in the air, can form a silicone rubber cured product that exhibits good adhesion to a substrate in contact during curing and is capable of inhibiting the occurrence of oil bleeding. Each component is described in more detail below. Note that, in the present specification, the viscosity is a value measured at 25 ℃ using a type B viscometer according to JIS K7117-1.

Component (a) is a base compound of the composition of the present invention, and is a mixture of (a1) an organopolysiloxane having at least two alkoxysilyl-containing groups represented by the following formula on a silicon atom in the molecular chain of each molecule and (a2) an organopolysiloxane having one alkoxysilyl-containing group represented by the following formula on a silicon atom in the molecular chain of each molecule.

In the formula, R¹Are the same or different monovalent hydrocarbon groups free of aliphatic unsaturation, examples of which include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and octadecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenethyl and phenylpropyl; and halogenated alkyl groups such as 3-chloropropyl and 3,3, 3-trifluoropropyl. Preferably an alkyl, cycloalkyl or aryl group, more preferably a methyl or phenyl group. In the formula, R²Is an alkyl group, examples of which include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and octadecyl. Preferably methyl or ethyl. In the formula, R³Are the same or different alkylene groups, and examples thereof include methylmethylene, ethylene, methylethylene, propylene, butylene, pentylene, hexylene, heptylene and octylene. Preferably a methyl methylene, ethylene, methyl ethylene or propylene group. In this formula, a is an integer of 0 to 2, preferably 0 or 1. In this formula, p is an integer of 1 to 50, preferably an integer of 1 to 20, more preferably an integer of 1 to 10, particularly preferably an integer of 1 to 5.

Examples of such alkoxysilyl group-containing groups include groups represented by the following formula:

a group represented by the formula:

a group represented by the formula:

a group represented by the formula:

a group represented by the formula:

a group represented by the formula:

a group represented by the formula:

examples of the group bonded to silicon atoms in the molecular chain of component (a1) and component (a2) include, in addition to the alkoxysilyl group-containing group, alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptylene, octyl, nonyl, decyl, and octadecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, pentenyl, hexenyl, and heptenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenethyl and phenylpropyl; and halogenated alkyl groups such as 3-chloropropyl and 3,3, 3-trifluoropropyl. Preferably an alkyl, cycloalkyl, alkenyl or aryl group, more preferably a methyl, vinyl or phenyl group.

The molecular structures of component (a1) and component (a2) are not limited, and may have, for example, a linear, partially branched linear, branched, or cyclic molecular structure, with a linear, partially branched linear, or branched molecular structure being preferred. The alkoxysilyl group-containing group may be bonded to a silicon atom at the molecular chain end, or to a silicon atom along the molecular chain. Taking component (a1) as an example, it is preferably an organopolysiloxane having a linear molecular structure and having the above-described alkoxysilyl group-containing groups on silicon atoms at both molecular chain ends. Taking component (a2) as an example, it is preferably an organopolysiloxane having a linear molecular structure and having the above-described alkoxysilyl group-containing group on a silicon atom at one molecular chain end.

The viscosity of component (A) as a whole at 25 ℃ is not limited, but is preferably in the range of 100 mPas to 1,000,000 mPas, more preferably in the range of 100 mPas to 100,000 mPas. When the viscosity of component (A) is not less than the minimum value of the range given above, the mechanical strength of the resulting silicone rubber cured product is improved, and when the viscosity is not more than the maximum value of the range given above, the handling and processability of the resulting composition is improved.

In component (a), the mass ratio of component (a1) to component (a2) is preferably 1:10 to 10:1, more preferably 1:9 to 9:1, even more preferably 1:7 to 7:1, particularly 1:5 to 5: 1. When the mass ratio of component (a1) to component (a2) is within this range, the silicone rubber cured product obtained from the composition of the present invention can have appropriate flexibility, and therefore, the adhesion of the silicone rubber cured product can be improved, and the occurrence of oil bleeding can be suppressed.

Examples of the method for producing component (A1) or component (A2) include methods described in Japanese unexamined patent application publication Nos. S62-207383A and S62-212488A.

Component (B) is a component for appropriately softening and improving the adhesion of the silicone rubber cured product obtained from the composition of the present invention. This component is an organopolysiloxane lacking hydroxyl groups and alkoxy groups on silicon atoms in the molecular chain. Examples of the group bonded to the silicon atom of component (B) other than the hydroxyl group and the alkoxy group include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and octadecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, pentenyl, hexenyl, and heptenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenethyl and phenylpropyl; and halogenated alkyl groups such as 3-chloropropyl and 3,3, 3-trifluoropropyl. Preferably an alkyl, cycloalkyl, alkenyl or aryl group, more preferably a methyl, vinyl or phenyl group. Examples of the component (B) include dimethylpolysiloxane capped at both molecular terminals with dimethylvinylsiloxy groups, dimethylpolysiloxane capped at both molecular terminals with trimethylsiloxy groups, and the like. The molecular structure of component (B) is not limited, and for example, may have a linear, partially branched linear, branched or cyclic molecular structure, with a linear, partially branched linear or branched molecular structure being preferred. The viscosity of component (B) at 25 ℃ is not limited, but is preferably in the range of 10 mPas to 1000000 mPas, more preferably in the range of 50 mPas to 100000 mPas. When the viscosity of component (B) is not less than the minimum value of the above range, the exudation of component (B) from the cured product of the obtained silicone rubber is controlled, and when the viscosity thereof is not more than the maximum value of the above range, the handling and processability of the obtained composition are improved.

The content of the component (B) is not limited, but for example, it is in the range of 1 to 100 parts by mass, preferably in the range of 1 to 80 parts by mass, more preferably in the range of 1 to 70 parts by mass, particularly preferably in the range of 1 to 60 parts by mass, relative to 100 parts by mass of the component (a). When the content of component (B) is greater than or equal to the minimum value of the range given above, the resulting composition has good adhesion, and when the content is less than or equal to the maximum value of the range given above, the bleeding of component (B) from the resulting silicone rubber cured product can be controlled. Specifically, the content of the component (B) is preferably in the range of 15 to 60 parts by mass with respect to 100 parts by mass of the component (a) because the adhesion with the organic resin is good at this time.

Component (C) is a component which is a crosslinking agent of the composition of the present invention, and is an alkoxysilane represented by the following general formula:

R⁴ _bSi(OR⁵)_(4-b)

(wherein R is⁴Is a monovalent hydrocarbon radical, R⁵Is alkyl, b is 0 to 2)

Or a partially hydrolyzed condensate thereof.

In the formula, R⁴Are identical or different monovalent hydrocarbon groups, examples of which include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl and octadecyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; alkenyl groups such as vinyl, allyl, butenyl, pentenyl, hexenyl, and heptenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenethyl and phenylpropyl; and halogenated alkyl groups such as 3-chloropropyl and 3,3, 3-trifluoropropyl. Preferably an alkyl, cycloalkyl, alkenyl or aryl group, more preferably a methyl group. Further, in this formula, R⁵Are the same or different alkyl groups, and examples thereof include methyl, ethyl, propyl, butyl, pentyl and hexyl groups. Preferably methyl.

Examples of the component (C) containing a bifunctional alkoxysilane such as dimethyldimethoxysilane, methylphenyldimethoxysilane and diphenyldimethoxysilane; trifunctional alkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane and phenyltrimethoxysilane; tetrafunctional alkoxysilanes such as tetramethoxysilane and tetraethoxysilane; and partially hydrolyzed condensates thereof. Component (C) may be one of these alkoxysilanes or their partial hydrolysis condensates, used alone or in combination of two or more thereof as a mixture.

The content of the component (C) is not limited, but for example, it is in the range of 0.5 to 30 parts by mass, preferably in the range of 0.5 to 20 parts by mass, more preferably in the range of 0.5 to 15 parts by mass, particularly preferably in the range of 0.5 to 10 parts by mass, relative to 100 parts by mass of the component (a). When the content of component (C) is not less than the minimum value of the range given above, curability of the resulting composition is sufficient, and under conditions of blocking moisture, the shelf life of the resulting composition is improved; when the content is not more than the maximum value of the range given above, the resulting composition is rapidly cured when exposed to moisture in the air.

Component (D) is a condensation reaction catalyst which promotes crosslinking of the composition of the present invention. Examples of the component (D) include tin compounds such as dimethyltin dineodecanoate and stannous octoate; and titanium compounds such as titanium tetra (isopropoxide), titanium tetra (n-butoxide), titanium tetra (t-butoxide), titanium di (isopropoxide) bis (ethylacetoacetate), titanium di (isopropoxide) bis (methylacetoacetate), titanium di (isopropoxide) bis (acetylacetonate), and the like.

The content of the component (D) is not limited, but is in the range of 0.1 to 10 parts by mass, preferably in the range of 0.1 to 6 parts by mass, relative to 100 parts by mass of the component (a). When the content of component (D) is not less than the minimum value of the range given above, the resulting composition is rapidly cured upon contact with moisture in the air, and when the content is not more than the maximum value of the range given above, the shelf life of the resulting composition is improved.

The room-temperature curable silicone rubber composition according to the present invention may further include components other than components (a) to (D); for example, it may further contain the following components (E) to (F).

Component (E) is a tackifier for improving the adhesion with the organic resin with which the composition of the present invention is contacted during curing. Examples of the adhesion promoter of component (E) include epoxy group-containing alkoxysilanes such as 3-glycidyloxytrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane and 4-oxysilylbutyltrimethoxysilane; acrylic group-containing alkoxysilanes such as 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane; amino group-containing alkoxysilanes such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltrimethoxysilane; and a reaction mixture of the above-mentioned epoxy group-containing alkoxysilane and the above-mentioned amino group-containing alkoxysilane, for example, silatrane carbonamide (carbasilatrane). Preferably a reaction mixture of the above-mentioned epoxy group-containing alkoxysilane and the above-mentioned amino group-containing alkoxysilane. Examples of the method for preparing such a reaction mixture of the above-mentioned epoxy group-containing alkoxysilane and amino group-containing alkoxysilane include the methods described in japanese examined patent application publication nos. s55-41702A and h07-113083 a.

The content of the component (E) is not limited provided that the content is sufficient to impart adhesiveness with the organic resin contacted during curing of the composition of the present invention, but the content is preferably in the range of 0.01 to 10 parts by mass, more preferably in the range of 0.01 to 5 parts by mass, relative to 100 parts by mass of the component (a). When the content of the component (E) is not less than the minimum value of the range given above, the adhesion with the organic resin is sufficient, and when the content is not more than the maximum value of the range given above, the resultant composition is rapidly cured upon contact with moisture in the air.

Component (F) is a reinforcing filler for imparting mechanical strength to the silicone rubber cured product obtained by curing the composition of the present invention and improving releasability from the substrate. Examples of the component (F) include fumed silica fine powder, precipitated silica fine powder, fused silica fine powder, calcined silica fine powder and fumed titania fine powder, glass fiber, and hydrophobized fine powder obtained by surface-treating these fine powders with an organosiloxane, silazane, or siloxane oligomer. Although there is no particular limitation on the particle diameter of the fine powder of component (F), the median particle diameter as measured using a laser diffraction/scattering type particle diameter distribution may be, for example, in the range of 0.01 to 1000 micrometers.

The content of the component (F) is not limited, but is preferably in the range of 0.1 to 50 parts by mass relative to 100 parts by mass of the component (a).

In addition, the composition of the present invention may further contain other optional components, provided that the object of the present invention is not hindered, examples of which include non-reinforcing fillers such as quartz fine powder, calcium carbonate fine powder, diatomaceous earth fine powder, aluminum hydroxide fine powder, alumina fine powder, magnesium hydroxide fine powder, magnesium oxide fine powder, zinc carbonate fine powder, and hydrophobized fine powder obtained by surface-treating these fine powders with an organosiloxane, silazane, and siloxane oligomer; an organic solvent; an antifungal agent; a flame retardant; a heat-resistant agent; a plasticizer; a thixotropy imparting agent; a curing accelerator; resists/migration inhibitors for wires or electrodes and/or pigments such as carbon black.

The present invention can be produced by uniformly mixing components (a) to (D) under moisture-barrier conditions and mixing components (E) and (F) and other optional components as necessary. The method of mixing the components of the silicone composition may be a conventionally known method, and is not particularly limited, but generally the uniform mixing is performed by simple agitation. Further, when a solid component such as an inorganic filler or the like is contained in the composition as an optional component, it is more preferable to perform mixing using a mixing device. Such a mixing device is not particularly limited, but examples thereof include a single-screw or twin-screw continuous mixer, a two-roll mill, a ross mixer, a hobart mixer, a dental mixer, a planetary mixer, a kneading mixer, a henschel mixer, and the like. The mixture of the present invention prepared in this way is sealed in an airtight container and kept under conditions of moisture-proof for a long period of time.

<Silicone rubber cured product>

The silicone rubber cured product of the present invention is obtained by curing the above-described room-temperature-curable silicone rubber composition. The method of curing the room-temperature-curable silicone rubber composition is not particularly limited, but generally the composition can be rapidly cured by contact with moisture in the air to form a silicone rubber cured product. This silicone rubber cured product exhibits good adhesion to a substrate contacted during curing and suppresses the occurrence of oil bleeding.

The silicone rubber cured product can exhibit good adhesion to various substrates. Examples of such substrates include various substrates such as glass, ceramics, mortar, concrete, wood, plastics, and metals. Examples of the plastic substrate include thermosetting resins such as epoxy resin, phenol resin, urea resin, melamine resin, and silicone resin, and thermoplastic resins such as polycarbonate resin, polyester resin, ABS resin, nylon resin, polyvinyl chloride resin, acrylonitrile resin, polybutylene terephthalate resin, polyphenylene sulfide resin, polyphenylene resin, and polyethylene terephthalate resin. Examples of metal substrates include metals such as copper, stainless steel, iron, zinc plate, tin plate, brass, zinc, and nickel.

<Electronic device>

The electronic device according to the present invention is provided with the silicone rubber cured product described above. The electronic device is not particularly limited, but examples thereof include an electronic device including a circuit or an electrode in which a metal oxide film electrode such as Indium Tin Oxide (ITO) is formed, and a metal electrode made of silver, copper, aluminum, gold, or the like on a substrate such as glass, epoxy resin, polyimide resin, phenol resin, ceramic, or the like. Examples of such electrodes include electrodes of Liquid Crystal Displays (LCDs), Flat Panel Displays (FPDs), and flat panel display devices. The compositions of the present invention are useful as coatings for such electrodes. The electronic device according to the present invention can be used for a fixed part because the silicone rubber cured product exhibits high adhesion to a substrate and has good reliability because it can suppress the occurrence of oil bleeding.

Examples of the invention

The room-temperature curable silicone rubber composition of the present invention will now be described using practical examples. Note that, in the present practical example, the viscosity is a value measured at 25 ℃ using a B type viscometer according to JIS K7117-1. Further, the adhesion between the silicone rubber cured product obtained by curing the room-temperature curable silicone rubber composition and the substrate and the occurrence of oil bleeding thereof were evaluated as follows.

<Method for evaluating adhesion of silicone rubber cured product to substrate>

An adhesive layer composed of a room temperature curable silicone rubber composition was formed to a thickness of 1mm on various substrates, and it was left standing at 25 ℃ and 50% RH for 7 days to cure the composition, thereby preparing samples. The sample was cut into strips (length 4.0 cm. times. width 1.0 cm. times. thickness 0.5mm), and then peel test was performed in the 180 degree direction at a speed of 50 mm/min. The condition of the damaged surface of the adhesive was macroscopically observed, and the rate at which the silicone rubber cured product underwent cohesive failure was determined as the rate of Cohesive Failure (CF). A high cohesive failure rate indicates that the silicone rubber cured product has good adhesion to the substrate. As the substrate, a substrate made of Glass (GL) and nylon 66(NY66) was used.

<Oil bleeding evaluation of Silicone rubber cured product>

0.2g of the room-temperature curable silicone rubber composition was dropped on a ground glass plate and allowed to stand at 25 ℃ and 50% RH for 7 days, and when the room-temperature curable silicone rubber composition was cured, the presence or absence of exuded (seeped) oil components was macroscopically observed.

The following raw materials were used to prepare room-temperature curable silicone rubber compositions in the practical examples and comparative examples:

component (a 1): a linear dimethylpolysiloxane having a viscosity of 500mPas, having trimethoxysilylethyl-containing groups on the silicon atoms at both molecular ends represented by the following formula:

component (a 2): a linear dimethylpolysiloxane having a viscosity of 500mPa s, and having a trimethoxysilylethyl group-containing group represented by the following formula on a silicon atom at one molecular end:

component (B-1): linear dimethylpolysiloxane having dimethylvinylsiloxy groups on silicon atoms at both molecular terminals and a viscosity of 400 mPas

Component (B-2): linear dimethylpolysiloxane having trimethylsiloxy groups on silicon atoms at both molecular terminals and a viscosity of 500mPas

A component (C): methyltrimethoxysilane

A component (D): bis (isopropoxy) titanium bis (acetoacetate)

A component (E): carboazasilatricycles (reaction mixtures of epoxy silanes and aminosilanes)

A component (F): fine fumed silica powder surface-treated with hexamethyldisilazane, having a particle size of 130m according to the BET method²Specific surface area per gram

Note that the above-mentioned component (a1) and component (a2) were prepared according to the method described in japanese unexamined patent application publication No. s62-207383 a.

<Practical examples 1 to 8 and comparative examples 1 to 4>

A room-temperature curable silicone rubber composition was prepared by uniformly mixing component (A1), component (A2), component (B-1), component (B-2), component (C), component (D), component (E), and component (F) in the blending amounts shown in Table 1 under moisture-barrier conditions. The silicone rubber cured products obtained by curing these room-temperature curable silicone rubber compositions were evaluated for adhesion and oil bleeding occurrence. Those results are shown in table 1.

TABLE 1

INDUSTRIAL APPLICABILITY

The room-temperature curable silicone rubber composition of the present invention cures at room temperature by contact with moisture in the air, and forms a silicone rubber cured product that exhibits good adhesion to a substrate in contact during curing and is capable of suppressing the occurrence of oil bleeding. Therefore, the product is advantageous for fixing electric and electronic parts and is useful as a sealant, an adhesive, or a moisture-proof coating agent, which makes it highly reliable.