JP2009292914A - Room temperature-curable silicone rubber composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance curability and adhesiveness of a condensation reaction type room temperature-curable silicone rubber composition that is cured at room temperature to produce a rubbery elastic material. <P>SOLUTION: The room temperature-curable silicone rubber composition contains: 10 to 90 parts by mass of polyorganosiloxane having viscosity of 0.02 to 100 Pa s, in which both molecular chain terminals are sequestered by hydroxy groups; 90 to 10 parts by mass of polyorgaosiloxane having viscosity of 0.02 to 100 Pa s, in which only one molecular chain terminal is sequestered by a hydroxy group; 0.1 to 10 parts by mass of a partial hydrolyzed condensate of a silane compound expressed by formula:R<SP>1</SP><SB>a</SB>Si(OR<SP>2</SP>)<SB>4-a</SB>(wherein R<SP>1</SP>and R<SP>2</SP>may be identical with or different from each other and represent substituted or unsubstituted monovalent hydrocarbon groups, and (a) represents an average number satisfying 0≤a≤0.2); and 0.1 to 10 parts by mass of an amine functional silane compound expressed by formula:(R<SP>3</SP>O)<SB>3</SB>Si-R<SP>4</SP>-NH-R<SP>5</SP>(wherein a plurality of R<SP>3</SP>may be identical or mutually different and represent substituted or unsubstituted monovalent hydrocarbon groups, R<SP>4</SP>represents a substituted or unsubstituted divalent organic group, and R<SP>5</SP>represents a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group, or an aminoalkyl group). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a condensation reaction type room temperature curable silicone rubber composition which is cured at room temperature to produce a rubbery elastic body.

  Condensation reaction type silicone rubber compositions that cure at room temperature to produce rubber-like elastic bodies are widely used in applications such as adhesives / sealants, potting materials, FIPG sealants for automobile parts, electrical / electronic equipment parts, etc. Yes.

  This condensation reaction type room temperature curable silicone rubber composition basically undergoes a curing reaction by contact with moisture in the air. As a catalyst for promoting the curing reaction, an organic metal such as tin is used. Acid salts, dialkyltin dialkoxides, dialkyltin dialkoxides, dialkyltin oxides, titanium tetraalkoxides and partial hydrolysis products thereof, titanium chelate compounds, zirconium chelate compounds, aluminum trialkoxides and partial hydrolysis condensates thereof, and An organic compound having a metal atom in the molecule, such as an aluminum chelate compound, is generally used.

  However, the room temperature curable silicone rubber composition using such a metal atom-containing organic compound as a catalyst has a problem that the curing time is long and the deep part curability is particularly poor.

  On the other hand, what improved the cure rate and improved deep part sclerosis | hardenability by using an amine functional silane compound as a catalyst instead of a metal atom containing organic compound is proposed (for example, refer patent document 1).

However, although the composition using this amine functional silane compound as a catalyst has improved curing speed and deep part curability, there is still room for improvement in adhesiveness.
Japanese National Publication No. 07-020019

  The present invention was made to solve such problems of the prior art, and aims to provide a room temperature curable silicone rubber composition having good curability and excellent adhesion to various substrates. To do.

  As a result of intensive studies to solve the problems of the prior art described above, the present inventor has found that polyorganosiloxane in which both molecular chain ends are blocked with a hydroxyl group and a polyorganosiloxane in which only one end of the molecular chain is blocked with a hydroxyl group. Uses organosiloxane as a base polymer, and uses a partially hydrolyzed condensate of an amine functional silane compound and tetraalkoxysilane as a curing catalyst and a crosslinking agent, respectively. It has been found that a room temperature curable silicone rubber composition having excellent properties can be obtained, and the present invention has been completed.

That is, the present invention
(A) 10 to 90 parts by mass of a polyorganosiloxane having a viscosity at 23 ° C. of 0.02 to 100 Pa · s at which both ends of the molecular chain are blocked with hydroxyl groups,
(B) 90-10 parts by mass of a polyorganosiloxane having a viscosity at 23 ° C. of 0.02 to 100 Pa · s in which only one molecular chain end is blocked with a hydroxyl group,
(C) General formula:
R ¹ _a Si (OR ² ) _4-a (1)
(In the formula, R ¹ and R ² are substituted or unsubstituted monovalent hydrocarbon groups which may be the same or different, and a is an average value of 0 ≦ a ≦ 0.2. .) 0.1 to 10 parts by mass of a partially hydrolyzed condensate of the silane compound represented by the formula:
_{^{(R 3 O) 3 Si-}} R 4 -NH-R 5 ... (2)
(Wherein R ³ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different from each other, R ⁴ is a substituted or unsubstituted divalent organic group, and R ⁵ Is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group or aminoalkyl group.) 0.1 to 10 parts by mass of an amine functional silane compound represented by
Is a room temperature curable silicone rubber composition characterized by comprising:

  The room temperature curable silicone rubber composition of the present invention has good curability and excellent adhesion to various substrates.

  Hereinafter, embodiments of the present invention will be described.

The polyorganosiloxane that is the component (A) of the room temperature curable silicone rubber composition of the present invention is one in which both ends of the molecular chain are blocked with hydroxyl groups, and is typically represented by the following general formula (3). It is a substantially linear polyorganosiloxane.

In formula (3), a plurality of R ⁶ are each a substituted or unsubstituted monovalent hydrocarbon group which may be the same as or different from each other. R ⁶ includes an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group and a dodecyl group; a cycloalkyl group such as a cyclohexyl group; a vinyl group and an allyl group An alkenyl group such as a group; an aryl group such as a phenyl group, a tolyl group and a xylyl group; an aralkyl group such as a benzyl group, a 2-phenylethyl group and a 2-phenylpropyl group; and a hydrogen atom of these hydrocarbon groups A halogenated alkyl group such as a chloromethyl group, a 3-chloropropyl group, or a 3,3,3-trifluoropropyl group, a part of which is substituted with another atom or group such as a halogen atom or a cyano group; Examples include cyanoalkyl groups such as 3-cyanopropyl group, halogenated aryl groups such as p-chlorophenyl group, and the like. Among these, the synthesis is easy, the component (A) has a low viscosity for the molecular weight, gives good extrudability to the composition before curing, and good physical properties to the composition after curing. Therefore, 85% or more of all organic groups are preferably methyl groups, and substantially all organic groups are more preferably methyl groups.

On the other hand, in particular, when imparting heat resistance, radiation resistance, cold resistance or transparency, a necessary amount of an aryl group as a part of R ⁶ , and when imparting oil resistance and solvent resistance, R ⁶ When a 3,3,3-trifluoropropyl group or a 3-cyanopropyl group is added as a part, or a surface having paintability is imparted, a long-chain alkyl group or an aralkyl group is a methyl group as a part of R ^6. It can be arbitrarily selected depending on the purpose, for example, in combination with a group.

  In addition, the polyorganosiloxane as the component (A) has a viscosity at 23 ° C. of 0.02 to 100 Pa · s. Therefore, n in the formula (3) is the viscosity of the component (A) at 23 ° C. A number (integer) in the range. If the viscosity of the component (A) at 23 ° C. is less than 0.02 Pa · s, the rubber-like elastic body after curing is insufficiently stretched. Conversely, if the viscosity exceeds 100 Pa · s, workability such as discharge properties and flow characteristics are obtained. Decreases. The preferred viscosity of the component (A) is in the range of 0.1 to 100 Pa · s, more preferably 0.5 to 50 Pa · s, because the properties required for the composition before and after curing are harmonized. Range.

The polyorganosiloxane that is the component (B) of the room temperature curable silicone rubber composition of the present invention is one in which only one end of the molecular chain is blocked with a hydroxyl group, and is typically represented by the following general formula (4). Substantially linear polyorganosiloxane.

In formula (4), a plurality of R ⁷ are each a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different, and examples thereof are the same as those for R ⁶ described above. Also, the description of ^{R 6} are all applied to ^{R 7.}

  The (B) component polyorganosiloxane has a viscosity at 23 ° C. of 0.02 to 100 Pa · s. Therefore, n in the formula (4) indicates that the viscosity of the (B) component at 23 ° C. is within the above range. It is a number (integer). When the viscosity of the component (B) at 23 ° C. is less than 0.02 Pa · s, the rubber-like elastic body after curing is insufficiently stretched. Conversely, when the viscosity exceeds 100 Pa · s, workability such as discharge properties and flow characteristics are obtained. Decreases. The preferred viscosity of the component (B) is in the range of 0.1 to 100 Pa · s, more preferably 0.5 to 50 Pa · s, because the properties required for the composition before and after curing are harmonized. Range.

  The mixing ratio of the component (A) and the component (B) is 10:90 to 90:10, preferably 20:80 to 80:20, more preferably 30:70 to 70:30 in terms of mass ratio. When the amount of the component (B) is less than the above range, the adhesiveness cannot be improved, and when it is more than the above range, the mechanical strength after curing becomes weak.

The component (C) of the room temperature curable silicone rubber composition of the present invention is a component that acts as a crosslinking agent for the components (A) and (B), and has the general formula:
R ¹ _a Si (OR ² ) _4-a (1)
It is a partial hydrolysis-condensation product of the silane compound shown by these.

In the formula (1), R ¹ and R ² are substituted or unsubstituted monovalent hydrocarbon groups which may be the same or different from each other, and are methyl group, ethyl group, propyl group, butyl group, pentyl Group, hexyl group, octyl group, decyl group, alkyl group such as dodecyl group; cycloalkyl group such as cyclohexyl group; alkenyl group such as vinyl group, allyl group; phenyl group, tolyl group, xylyl group, etc. An aryl group; an aralkyl group such as a benzyl group, a 2-phenylethyl group, and a 2-phenylpropyl group, and a part of hydrogen atoms of these hydrocarbon groups is substituted with another atom or group such as a halogen atom, For example, a halogenated alkyl group such as chloromethyl group, 3-chloropropyl group, 3,3,3-trifluoropropyl group; Substituted hydrocarbon groups such as Noarukiru groups. Further, a is an average value of 0 ≦ a ≦ 0.2, and preferably 0 ≦ a ≦ 0.1.

  In the partially hydrolyzed condensate of component (C), the number of Si in one molecule is preferably 3-20, and more preferably 4-15. When the number of Si is less than 3, sufficient curability cannot be obtained, and when it exceeds 20, curability and mechanical properties after curing are deteriorated.

  (C) The partial hydrolysis-condensation product of the silane compound of a component may be used individually by 1 type, and 2 or more types may be mixed and used for it.

  (C) The compounding quantity of a component is 0.1-10 mass parts with respect to 100 mass parts of total amounts of (A) and (B) component, Preferably it is 0.5-5 mass parts. If the amount is less than 0.1 part by mass, crosslinking is not sufficiently performed and not only a cured product having low hardness is obtained, but also the storage stability of the composition containing the crosslinking agent becomes poor. On the contrary, if it exceeds 10 parts by mass, the shrinkage rate at the time of curing is increased, and physical properties such as elasticity after curing are lowered.

The component (D) of the room temperature curable silicone rubber composition of the present invention is a component that acts as a curing catalyst for promoting the reaction between the components (A) and (B) and the component (C).
_{^{(R 3 O) 3 Si-}} R 4 -NH-R 5 ... (2)
Is an amine functional silane compound.

In formula (2), R ³ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same as or different from each other, and is the same group as R ¹ and R ^{2 in the} component (C) described above. Is exemplified. R ⁴ is a substituted or unsubstituted divalent organic group such as an alkylene group such as a methylene group, an ethylene group, a propylene group, a tetramethylene group, a hexamethylene group, or a methylethylene group, a phenylene group, or a tolylene group. And an arylene group such as an arylene group, a methylenephenylene group, and a methylenephenylene group. Further, R ⁵ represents a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group such as an alkyl group such as a methyl group, an ethyl group, a propyl group, or a butyl group, or an aminoethyl group or an N-aminoethylaminoethyl group. And the like.

Specific examples of the component (D) include those shown below.

（式中、Ｒ^３およびＲ^４は前記と同様の基であり、Ｒ^８は水素原子またはアルキル基であり、複数のＲ^９は同一であっても異なっていてもよい水素原子またはメチル基であり、Ｒ^１０は前記のＲ^１およびＲ^２と同様の１価の炭化水素基またはこれらの基の水素原子の一部が‐Ｓｉ（ＯＲ^３）_３で置換された基であり、ｍは０、１または２である。） The amine functional silane compound of component (D) may also be an adduct with an acrylic ester or methacrylic ester represented by the following general formula (5).

(Wherein R ³ and R ⁴ are the same groups as described above, R ⁸ is a hydrogen atom or an alkyl group, and a plurality of R ⁹ is a hydrogen atom or a methyl group which may be the same or different. R ¹⁰ is a monovalent hydrocarbon group similar to R ¹ and R ² described above, or a group in which a part of hydrogen atoms of these groups is substituted with —Si (OR ³ ) ₃ , and m is 0 1 or 2.)

Examples of such compounds include those shown below.

Such amine functional silane compounds as component (D) may be used alone or in combination of two or more. As the component (D), (CH ₃ O) ₃ SiC ₃ H ₆ NHC ₂ H ₄ NH ₂ and (C ₂ H ₅ O) ₃ SiC ₃ H ₆ NH ₂ are particularly preferable.

  The compounding amount of the component (D) is 0.1 to 10 parts by mass, preferably 1 to 5 parts by mass with respect to 100 parts by mass of the total amount of the components (A) and (B). If the amount is less than 0.1 parts by mass, a sufficient curing rate cannot be obtained. Conversely, if the amount exceeds 10 parts by mass, the physical properties after curing may decrease.

  The room temperature curable silicone rubber composition of the present invention has a molar ratio of hydroxyl groups in the components (A) and (B) to alkoxy groups in the components (C) and (D) from the viewpoints of adhesiveness, curability and the like. Is preferably 2 to 50. The molar ratio is more preferably 3 to 30, and even more preferably 5 to 30.

  In the room temperature curable silicone rubber composition of the present invention, various fillers as the component (E) are blended as necessary as long as the effects of the present invention are not impaired in order to impart necessary physical characteristics. Can do. Fillers used include fumed silica, silica aerogel, precipitated silica, diatomaceous earth, fused silica, quartz powder, oxides such as iron oxide, zinc oxide and titanium oxide; these surfaces are coated with trimethylchlorosilane, dimethyldichlorosilane, hexa Treated with hydrophobizing agents such as methyldisilazane and octamethylcyclotetrasiloxane; carbonates such as calcium carbonate, magnesium carbonate and zinc carbonate; complex oxides such as glass wool and mica fine powder; carbon black, copper powder and nickel Examples include conductive fillers such as powder; synthetic resin powders such as polymethylsilsesquioxane, polystyrene, polyvinyl chloride, and polypropylene.

  It is preferable that the compounding quantity of the filler of these (E) components is 1-200 mass parts with respect to 100 mass parts of total amounts of (A) and (B) component, and is 5-100 mass parts. Is more preferable. If it is less than 1 part by mass, the effect cannot be sufficiently obtained by addition, and if it exceeds 100 parts by mass, workability such as dischargeability and flow characteristics are deteriorated.

  In addition, the room temperature curable silicone rubber composition of the present invention exhibits excellent adhesion to various substrates by using the components (A) and (B) in combination as a base polymer, but further increases the adhesion. Therefore, conventionally known various adhesion improvers can be blended. Examples of the adhesion improver used include isocyanuric ring-containing silicon compounds such as 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyl. An epoxy group-containing silane such as methyldimethoxysilane is exemplified.

  The compounding amount of these adhesion improvers is preferably 0.1 to 10 parts by mass, and 0.5 to 5 parts by mass with respect to 100 parts by mass of the total amount of components (A) and (B). It is more preferable.

  In the room temperature curable silicone rubber composition of the present invention, various additives generally blended in this type of composition can be blended as necessary within a range not inhibiting the effects of the present invention. Examples of such additives include pigments, dyes, thixotropic agents, viscosity modifiers for improving extrusion workability, ultraviolet absorbers, fungicides, and heat resistance improvers.

  However, in the room temperature curable silicone rubber composition of the present invention, a metal atom that functions as a curing catalyst containing a metal atom, that is, a curing catalyst that promotes curing based on the crosslinking reaction of the components (A) and (B). It is preferable that substantially no organic compound is contained. Specific examples of such curing catalysts include carboxylic acid metal salts such as iron octoate, manganese octoate, zinc octoate, tin naphthate, tin caprylate, tin oleate; dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin diiolate Organic tin compounds such as dirate, diphenyltin diacetate, dibutyltin oxide, dibutyltin dimethoxide, dibutylbis (triethoxysiloxy) tin, dioctyltin dilaurate; tetraethoxytitanium, tetrapropoxytitanium, tetrabutoxytitanium, 1,3-propoxytitaniumbis Alkoxy titaniums such as (ethyl acetyl acetate); aluminum tris acetyl acetonate, aluminum tris ethyl acetoacetate Organoaluminum compounds such as diisopropoxyaluminum ethyl acetoacetate, triethoxyaluminum; organozirconium compounds such as zirconium tetraacetylacetonate, tetraisopropoxyzirconium, tetrabutoxyzirconium, tributoxyzirconium acetylacetonate, tributoxyzirconium stearate Etc.

  The room temperature curable silicone rubber composition of the present invention is obtained by mixing the above components (A) to (D) and various components blended as necessary in a state where moisture is blocked. The obtained composition can be used as a so-called one-packaging room temperature curable composition that is stored as it is in a closed container and cured only by exposure to moisture in the air during use. In addition, the composition of the present invention is prepared as a composition in which, for example, a crosslinking agent and a curing catalyst are separated, and is stored in two or three separate containers as appropriate, and these are mixed at the time of use. It can also be used as a room temperature curable composition. The room temperature curable polyorganosiloxane composition of the present invention is a composition (main component) containing the above components (A), (B), (E) and various components blended as necessary, and the above (C). , (D) and a component (curing agent component) containing various components to be blended as necessary are prepared, stored separately in a state where moisture is blocked, and a two-component type in which these are mixed at the time of use. preferable.

  The room temperature curable silicone rubber composition obtained according to the present invention is stable under sealed conditions where moisture is not present, and is cured at room temperature upon contact with moisture in the air to produce a rubber-like elastic body. In particular, according to the present invention, compared with a room temperature curable silicone rubber composition using a conventional metal atom-containing organic compound as a catalyst, the curing speed is fast and the deep part curability is excellent, and it is excellent for various substrates. A room temperature curable silicone rubber composition exhibiting excellent adhesion can be obtained. Accordingly, the composition of the present invention is useful as an elastic adhesive for automobile parts, electrical / electronic devices, coating materials, potting materials, FIPG sealing materials, etc., and also as a field forming gasket, a building sealing material, etc. Useful.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, these examples do not limit the scope of the present invention. In Examples, “part” means “part by mass”, and all physical properties such as viscosity are values at 23 ° C. and relative humidity 50%.

Example 1
40 parts of polydimethylsiloxane blocked with hydroxyl groups at both ends of the molecular chain (viscosity: 0.5 Pa · s, hydroxyl content 0.1 mmol / g), polydimethylsiloxane blocked at both ends of the molecular chain with hydroxyl groups and trimethylsilyl groups, respectively (Viscosity: 0.5 Pa · s, hydroxyl group content 0.05 mmol / g) Partial hydrolysis-condensation of a main component composed of 60 parts and 20 parts of pulverized quartz and a silane compound represented by the formula: Si (OC ₂ H ₅ ) ₄ A polyorganosiloxane is uniformly mixed with a hardener component consisting of 3 parts of a product (5 Si number) and 1 part of an amine functional silane compound represented by the formula: H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ A composition was obtained.

Example 2
30 parts of polydimethylsiloxane blocked with hydroxyl groups at both ends of the molecular chain (viscosity: 0.5 Pa · s, hydroxyl content 0.1 mmol / g), polydimethylsiloxane blocked at both ends of the molecular chain with hydroxyl groups and trimethylsilyl groups, respectively (Viscosity: 0.5 Pa · s, hydroxyl group amount 0.05 mmol / g) Partial hydrolysis condensation of a main component composed of 70 parts and 20 parts of pulverized quartz and a silane compound represented by the formula: Si (OC ₂ H ₅ ) ₄ A polyorganosiloxane was uniformly mixed with a hardener component consisting of 3 parts of a product (Si number 7) and 1 part of an amine functional silane compound represented by the formula: H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ A composition was obtained.

Example 3
50 parts of polydimethylsiloxane blocked with hydroxyl groups at both ends of molecular chain (viscosity: 0.5 Pa · s, hydroxyl content 0.1 mmol / g), polydimethylsiloxane with both ends of molecular chain blocked with hydroxyl and trimethylsilyl groups, respectively (Viscosity: 0.5 Pa · s, hydroxyl group amount 0.05 mmol / g) Partial hydrolysis-condensation of a main component composed of 50 parts and 20 parts of pulverized quartz and a silane compound represented by the formula: Si (OC ₂ H ₅ ) ₄ 3 parts of product (Si number 5), 1 part of amine functional silane compound represented by the formula: H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ and 1,3,5-tris (3-trimethoxysilyl) A curing agent component comprising 0.5 part of propyl) isocyanurate was uniformly mixed to obtain a polyorganosiloxane composition.

Example 4
40 parts of polydimethylsiloxane blocked with hydroxyl groups at both ends of the molecular chain (viscosity: 0.5 Pa · s, hydroxyl content 0.1 mmol / g), polydimethylsiloxane blocked at both ends of the molecular chain with hydroxyl groups and trimethylsilyl groups, respectively (Viscosity: 0.5 Pa · s, hydroxyl group content 0.05 mmol / g) Partial hydrolysis-condensation of a main component composed of 60 parts and 20 parts of pulverized quartz and a silane compound represented by the formula: Si (OC ₂ H ₅ ) ₄ A polyorganosiloxane composition is obtained by uniformly mixing 3 parts of a product (5 Si) and 1 part of an amine functional silane compound represented by the formula: H ₂ NC ₃ H ₆ Si (OCH ₃ ) _3. It was.

Example 5
30 parts of polydimethylsiloxane blocked with hydroxyl groups at both ends of the molecular chain (viscosity: 0.5 Pa · s, hydroxyl content 0.1 mmol / g), polydimethylsiloxane blocked at both ends of the molecular chain with hydroxyl groups and trimethylsilyl groups, respectively (Viscosity: 0.5 Pa · s, hydroxyl group content 0.1 mmol / g) Partial hydrolysis condensation of a main component composed of 70 parts and 20 parts of pulverized quartz and a silane compound represented by the formula: Si (OC ₂ H ₅ ) ₄ A curing agent component consisting of 3 parts of a product (Si number 7) and 1 part of an amine functional silane compound represented by the formula: H ₂ NC ₃ H ₆ Si (OCH ₃ ) ₃ is uniformly mixed to obtain a polyorganosiloxane composition. It was.

Comparative Example 1
A main component composed of 100 parts of polydimethylsiloxane (viscosity: 0.5 Pa · s, hydroxyl group content 0.1 mmol / g) and 20 parts of pulverized quartz, both ends of which are blocked with hydroxyl groups, and a formula: Si (OC ₂ H ₅ ) From ₃ parts of a partially hydrolyzed condensate (Si number 5) of a silane compound represented by 4 and 1 part of an amine functional silane compound represented by the formula: H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ The resulting curing agent component was uniformly mixed to obtain a polyorganosiloxane composition.

Comparative Example 2
A main component composed of 100 parts of polydimethylsiloxane (viscosity: 0.5 Pa · s, hydroxyl group content 0.1 mmol / g) and 20 parts of pulverized quartz, both ends of which are blocked with hydroxyl groups, and a formula: Si (OC ₂ H _{5) 4} in indicated by a silane compound 3 parts of _{formula: H 2 NC 2 H 4 NHC} 3 H 6 Si (OCH 3) a curing agent component were uniformly mixed consisting of amine-functional silane compound, 1 part represented by _3, poly An organosiloxane composition was obtained.

Comparative Example 3
A main component composed of 100 parts of polydimethylsiloxane (viscosity: 0.5 Pa · s, hydroxyl group content 0.1 mmol / g) and 20 parts of pulverized quartz, both ends of which are blocked with hydroxyl groups, and a formula: Si (OC ₂ H ₅ ) ₃ parts of a partially hydrolyzed condensate (Si number 5) of the silane compound represented by 4, 1 part of an amine functional silane compound represented by the formula: H ₂ NC ₂ H ₄ NHC ₃ H ₆ Si (OCH ₃ ) ₃ and A curing agent component consisting of 0.5 part of 1,3,5-tris (3-trimethoxysilylpropyl) isocyanurate was uniformly mixed to obtain a polyorganosiloxane composition.

Various characteristics of the polyorganosiloxane compositions prepared in the above Examples and Comparative Examples were evaluated by the methods described below. The results are shown in Table 1.
[Curing property]
Under an atmosphere of 23 ° C. and 50% RH, the composition was poured into a mold to a thickness of 6 mm, and properties (cured state) after 2 hours, 4 hours and 8 hours were examined.
[Adhesiveness]
A room temperature curable silicone rubber composition is applied to various base materials (PBT (polybutylene terephthalate), PPE (polyphenylene ether), PPS (polyphenylene sulfide)) so as to have a length of 50 mm, a width of 10 mm, and a thickness of 1 mm. Then, the specimens were allowed to stand for 3 days in an atmosphere of 23 ° C. and 50% RH to be cured, and the cohesive failure rate of these specimens was measured.

  As is clear from Table 1, the polyorganosiloxane compositions prepared in Examples 1 to 5 are superior in curability and adhesiveness compared to the polyorganosiloxane compositions obtained in Comparative Examples 1 to 3. In particular, the adhesion is greatly improved.

Claims (7)

(A) 10 to 90 parts by mass of a polyorganosiloxane having a viscosity at 23 ° C. of 0.02 to 100 Pa · s at which both ends of the molecular chain are blocked with hydroxyl groups,
(B) 90-10 parts by mass of a polyorganosiloxane having a viscosity at 23 ° C. of 0.02 to 100 Pa · s in which only one molecular chain end is blocked with a hydroxyl group,
(C) General formula:
R ¹ _a Si (OR ² ) _4-a (1)
(In the formula, R ¹ and R ² are substituted or unsubstituted monovalent hydrocarbon groups which may be the same or different, and a is an average value of 0 ≦ a ≦ 0.2. .) 0.1 to 10 parts by mass of a partially hydrolyzed condensate of a silane compound represented by ()) and (D) a general formula):
_{^{(R 3 O) 3 Si-}} R 4 -NH-R 5 ... (2)
(Wherein R ³ is a substituted or unsubstituted monovalent hydrocarbon group which may be the same or different from each other, R ⁴ is a substituted or unsubstituted divalent organic group, and R ⁵ Is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group or aminoalkyl group.) 0.1 to 10 parts by mass of an amine functional silane compound represented by
A room temperature curable silicone rubber composition comprising:   2. The room temperature curing property according to claim 1, wherein the molar ratio of the hydroxyl groups in the components (A) and (B) to the alkoxy groups in the components (C) and (D) is 2-50. Silicone rubber composition.   The room temperature curable silicone rubber composition according to claim 1 or 2, wherein the viscosity at 23 ° C of the component (A) is 0.1 to 100 Pa · s.   The room temperature curable silicone rubber composition according to any one of claims 1 to 3, wherein the viscosity of the component (B) at 23 ° C is 0.1 to 100 Pa · s.   The room temperature curable silicone rubber composition according to any one of claims 1 to 4, which is substantially free of a curing catalyst containing a metal atom.   6. The filler according to claim 1, further comprising (E) 1 to 200 parts by mass of a filler with respect to 100 parts by mass of the total amount of the components (A) and (B). Room temperature curable silicone rubber composition.   A composition containing at least the components (A) and (B) and not containing the components (C) and (D), and containing at least the components (C) and (D), and (A) and (B) The room temperature curable silicone rubber composition according to any one of claims 1 to 6, which is a two-component room temperature curable silicone rubber composition comprising a composition containing no components.