JP2012036252A - Room temperature-curable organopolysiloxane composition and vehicle oil seal - Google Patents

Abstract

A deoxime room temperature curable organopolysiloxane composition having excellent initial curability and adhesive aging stability exhibited at the beginning of manufacture and excellent chemical resistance, particularly engine oil resistance, and Provided is an automotive oil seal obtained by curing the composition.
A silane coupling agent having an alkoxy group which is usually used as an adhesion assistant is changed to a silane coupling agent having an oxime group and added.
[Selection figure] None

Description

  The present invention is a deoxime room temperature curable organopolysiloxane composition that is excellent in initial curability and adhesive aging stability that are exhibited at the beginning of manufacture, and excellent in chemical resistance (particularly engine oil resistance). The present invention relates to a room temperature curable organopolysiloxane composition excellent in adhesiveness, which is mainly useful as an automotive FIPG (Formed In Place Gaskets) material, and an automobile oil seal obtained by curing the composition.

Conventionally, oil-resistant gaskets and packing materials made of cork, organic rubber, asbestos, etc. have been used for the seals around automobile engines, but this has the disadvantage of complicated inventory management and work processes. Further, there is a drawback that the sealing performance is not reliable. For this reason, the FIPG method using a room temperature curable organopolysiloxane composition has been adopted for this type of use, and has been highly evaluated in terms of workability, sealing property, and heat resistance.
Condensation-curing room-temperature fast-curing organopolysiloxane compositions are conventionally one solution in which the crosslinking agent is reduced to the utmost to improve the crosslinking rate by hydrolysis with respect to the both-end hydroxyorganopolysiloxane as the base polymer. There are known two-component type and two-component type in which both ends hydroxyorganopolysiloxane as a base polymer and a crosslinking agent are separately packaged and mixed at the time of use.

Conventionally known deoxime room temperature curable organopolysiloxane compositions generally use an oxime silane having an oxime group as a curing agent and a dealcohol-free silane coupling agent having an alkoxy group as an adhesion assistant. It is.
However, the composition as described above causes a transesterification reaction between the oxime group of the curing agent and the alkoxy group of the adhesion assistant over time, and changes to a curing agent or an adhesion assistant in which oxime-alkoxy groups are mixed, As a result, there has been a problem that the initial curability and adhesiveness exhibited in the initial stage of manufacture change with time. In particular, it is reported in Japanese Patent No. 3818365, Japanese Patent Application Laid-Open No. 2002-309219, Japanese Patent Application Publication No. 2003-535152, Japanese Patent Application Laid-Open No. 2005-298558, and Japanese Patent Application Laid-Open No. 2007-204575 (Patent Documents 1 to 5). In the FIPG material for difficult-to-adhere materials and the two-component mixed / deoxime room temperature curing organopolysiloxane composition reported in Japanese Patent No. 3916403 and Japanese Patent No. 3970484 (Patent Documents 6 and 7) In addition, since it is necessary to increase the addition amount of the adhesion assistant, there is a problem that the initial curability and adhesiveness that are exhibited at the beginning of the production decrease as a result.

Japanese Patent No. 3818365 JP 2002-309219 A Special table 2003-535152 gazette JP 2005-298558 A JP 2007-204575 A Japanese Patent No. 3916403 Japanese Patent No. 3970484

  The present invention has been made in view of the above circumstances, and is a deoxime type room temperature that is excellent in initial curability and adhesive stability that are exhibited at the beginning of manufacture, and that is excellent in chemical resistance, particularly in engine oil resistance. It is an object of the present invention to provide a curable organopolysiloxane composition and an automobile oil seal obtained by curing the composition.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors changed and added a silane coupling agent having an alkoxy group, which is usually used as an adhesion assistant, to a silane coupling agent having an oxime group. In this way, the transesterification reaction between the curing agent and the adhesion assistant over time is suppressed / suppressed, resulting in excellent initial curability and adhesive stability over time that are exhibited at the beginning of production, and chemical resistance, It has been found that a deoxime-type room temperature curable organopolysiloxane composition having excellent engine oil resistance can be obtained, and the present invention has been made.

（式中、Ｒ⁴、Ｒ⁶、Ｒ⁷、ｄ、ｆは上記と同じである。）
〔請求項３〕
更に、（Ｅ）下記一般式（９）で示されるシランカップリング剤及び／又はその部分加水分解物を、上記（Ｃ）成分と（Ｅ）成分の存在質量比が、０．７０≦（Ｃ）成分／［（Ｃ）成分＋（Ｅ）成分］＜１．０となる範囲内で含む請求項１又は２に記載の室温硬化性オルガノポリシロキサン組成物。
Ｒ⁹ _gＲ¹⁰ _hＳｉ（ＯＲ⁸）_4-g-h （９）
（式中、Ｒ⁸は独立に炭素数１〜６の一価炭化水素基であり、Ｒ⁹は独立に窒素原子、硫黄原子、酸素原子から選ばれる１種又は２種以上を含む炭素数１〜１０の非置換又は置換一価炭化水素基であり、Ｒ¹⁰は炭素数１〜１０の非置換又はハロゲン原子置換一価炭化水素基であり、ｇは１又は２、ｈは０又は１、ｇ＋ｈは１又は２である。）
〔請求項４〕
請求項１〜３のいずれか１項に記載の組成物を硬化させることにより得られる自動車オイルシール。 Accordingly, the present invention provides the room temperature curable organopolysiloxane composition and automobile oil seal shown below.
[Claim 1]
(A) 100 parts by mass of an organopolysiloxane represented by the following general formula (1),
HO (SiR ¹ ₂ O) _a H (1)
(Wherein R ¹ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ¹ may be the same or different from each other. A is 10 or more. (It is an integer.)
(B) A silane compound having at least two ketoxime groups represented by the following general formula (2) and / or a partial hydrolyzate thereof in an amount of 0.1 to 30 parts by mass,
R ³ _b Si (ON = CR ² ₂ ) _4-b (2)
(In the formula, R ² is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is a methyl group and / or vinyl group, and b is 0, 1 or 2. )
(C) A silane compound represented by the following general formula (3), a reaction product of a silane compound represented by the following general formula (3) and a silane compound represented by the following general formula (4), or a partial hydrolyzate thereof. Or 0.1-10 parts by mass of a mixture thereof,
R ⁵ _c R ⁶ _d Si (ON = CR ⁴ ₂ ) _4-cd (3)
(In the formula, R ⁴ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁵ is independently selected from one or more selected from a nitrogen atom, a sulfur atom, and an oxygen atom. An unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ⁶ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, c is 1 or 2, and d is 0 or 1, and c + d is 1 or 2.)
(XR ⁷ ) _e R ⁶ _f Si (ON = CR ⁴ ₂ ) _4-ef (4)
Wherein R ⁴ and R ⁶ are the same as above, R ⁷ is independently an unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, and X is a chlorine atom, a bromine atom or a (meth) acryl group. E is 1 or 2, f is 0 or 1, and e + f is 1 or 2.)
(D) A room temperature-curable organopolysiloxane composition comprising 1 to 300 parts by mass of at least one filler.
[Claim 2]
The room temperature-curable organopolysiloxane composition according to claim 1, wherein the component (C) is selected from the compounds represented by the following general formulas (5) to (8).

(In the formula, R ⁴ , R ⁶ , R ⁷ , d, and f are the same as above.)
[Claim 3]
Further, (E) a silane coupling agent represented by the following general formula (9) and / or a partial hydrolyzate thereof, the mass ratio of the component (C) and the component (E) is 0.70 ≦ (C 3) The room temperature-curable organopolysiloxane composition according to claim 1 or 2, which is contained within a range where component / [component (C) + component (E)] <1.0.
R ⁹ _g R ¹⁰ _h Si (OR ⁸ ) _4-gh (9)
(In the formula, R ⁸ is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ⁹ is independently 1 or 2 or more carbon atoms selected from a nitrogen atom, a sulfur atom, and an oxygen atom. 10 is an unsubstituted or substituted monovalent hydrocarbon group having 10 to ¹⁰ carbon atoms, R ¹⁰ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to ¹⁰ carbon atoms, g is 1 or 2, h is 0 or 1, g + h is 1 or 2.)
[Claim 4]
The automobile oil seal obtained by hardening the composition of any one of Claims 1-3.

  According to the present invention, a deoxime that can suppress / suppress the phenomenon that the curability and adhesiveness at the beginning of production in a conventional composition are lowered over time, and has excellent chemical resistance (particularly engine oil resistance). A room temperature curable organopolysiloxane composition of the type can be obtained. The composition of the present invention can be expected to be applied to industries that require initial curability maintenance, and is particularly effective for automotive applications.

Hereinafter, the present invention will be described in more detail. The component (A) of the room temperature curable organopolysiloxane composition of the present invention is an organopolysiloxane represented by the following general formula (1).
HO (SiR ¹ ₂ O) _a H (1)

In the above formula (1), R ¹ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, or a butyl group. Alkyl groups such as hexyl group and octyl group; cycloalkyl groups such as cyclohexyl group; alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group and hexenyl group; aryl groups such as phenyl group and tolyl group; benzyl group An aralkyl group such as phenylethyl group, or a group in which part or all of hydrogen atoms of these groups are substituted with a halogen atom such as chlorine, fluorine or bromine, such as chloropropyl group or trifluoropropyl group. Among these, a methyl group and a phenyl group are preferable, and a methyl group is particularly preferable. R ¹ may be the same group or a different group.
Further, a in the formula (1) is an integer of 10 or more, and the number of the organopolysiloxane having a viscosity at 23 ° C. in the range of 25 to 500,000 mPa · s, particularly in the range of 500 to 100,000 mPa · s. It is preferable that In the present invention, the viscosity is a value measured with a rotational viscometer at 23 ° C.

Next, the component (B) is a silane compound having two or more ketoxime groups represented by the following general formula (2) and / or a partial hydrolyzate thereof.
R ³ _b Si (ON = CR ² ₂ ) _4-b (2)
(Wherein R ² is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, R ³ is a methyl group and / or vinyl group, b is 0, 1 or 2)

In the above formula (2), R ² can be exemplified by the same groups as those described above for R ¹ , preferably a methyl group, an ethyl group, or an isobutyl group.

Specific examples of the silane compound represented by the formula (2) include methyltris (dimethylketoxime) silane, methyltris (methylethylketoxime) silane, methyltris (methylisobutylketoxime) silane, vinyltris (methylethylketoxime) silane, vinyltris (dimethylketo). Examples thereof include ketoxime silanes such as oxime) silane and vinyltris (methylisobutylketoxime) silane.
(B) component can be used individually by 1 type or in combination of 2 or more types.

  The (B) component silane compound and its partial hydrolyzate are used in an amount of 0.1 to 30 parts by weight, preferably 1 to 15 parts by weight, per 100 parts by weight of the (A) component organopolysiloxane. If the blending amount is too small, sufficient crosslinking cannot be obtained, and the composition does not have the desired rubber elasticity. If the blending amount is too large, the mechanical properties are poor.

  Next, the component (C) includes a silane compound having two or more ketoxime groups represented by the following general formula (3) and / or a partial hydrolyzate thereof, or this silane compound and the following general formula (4). Is a reaction product with a silane compound having two or more ketoxime groups in the molecule and / or a partial hydrolyzate thereof. It is an essential component for developing adhesiveness.

R ⁵ _c R ⁶ _d Si (ON = CR ⁴ ₂ ) _4-cd (3)
Wherein R ⁴ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and R ⁵ is independently selected from a nitrogen atom, a sulfur atom and an oxygen atom. An unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms including two or more species, R ⁶ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and c is 1 or 2, d is 0 or 1, and c + d is 1 or 2.)
(XR ⁷ ) _e R ⁶ _f Si (ON = CR ⁴ ₂ ) _4-ef (4)
Wherein R ⁴ and R ⁶ are the same as above, R ⁷ is independently an unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, and X is a chlorine atom, a bromine atom or a (meth) acryl group. E is 1 or 2, f is 0 or 1, and e + f is 1 or 2.)

In the above formulas (3) and (4), R ⁴ may be the same as R ² described above, and preferably a methyl group, an ethyl group, or an isobutyl group.
Moreover, in said formula (3), R < ⁵ > is C1-C10 containing 1 type, or 2 or more types chosen from a nitrogen atom, a sulfur atom, and an oxygen atom, Preferably it is unsubstituted or substituted monovalent of 1-7. Examples of the hydrocarbon group include amino group-containing groups, amide group-containing groups, mercapto group-containing groups, isocyanate group-containing groups, epoxy group-containing groups, and (meth) acryl group-containing groups. As R ⁵ , —R ⁷ NH ₂ , —R ⁷ NHR ⁷ NH _2, —R ⁷ NHCONH _2, —R ⁷ SH, —R ⁷ NCO, —R ⁷ O—R ⁷ CH (O) CH _2, etc. Can be mentioned. Among these, an amino group-containing monovalent hydrocarbon group such as —R ⁷ NH ₂ , —R ⁷ NHR ⁷ NH ₂ (R ⁷ is an unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms) is preferable. Specific examples include aminoethyl group, aminopropyl group, 3- (2-aminoethylamino) propyl group and the like.

In the above formulas (3) and (4), R ⁶ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and R ⁶ is the above R ¹ . The thing similar to what was mentioned can be illustrated, Preferably it is a methyl group.

In said formula (4), X is a chlorine atom, a bromine atom, an acryl group, or a methacryl group, and a chlorine atom, an acryl group, and a methacryl group are preferable.
R ⁷ is an unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, such as methylene group, ethylene group, trimethylene group, propylene group, tetramethylene group, 1,1- Examples thereof include alkylene groups such as a dimethyltetramethylene group, a butylene group, and an octylene group, and a methylene group, an ethylene group, and a propylene group are preferable.

  As specific examples of the silane compound represented by the formula (3), many silane compounds can be exemplified, and among them, a silane containing a monovalent hydrocarbon group containing a nitrogen atom in the molecule as a functional group. A compound is preferred.

（式中、Ｒ⁴、Ｒ⁶、Ｒ⁷、ｄ、ｆは上記と同じである。）
これらの中でも式（５）で示されるシラン化合物が特に好ましい。 When the compounds represented by the following general formulas (5) to (8) are particularly used as the component (C), it is possible to obtain suppression and suppression of aging change of the curability and good adhesiveness in the composition.

(In the formula, R ⁴ , R ⁶ , R ⁷ , d, and f are the same as above.)
Among these, the silane compound represented by the formula (5) is particularly preferable.

Specific examples of the compounds represented by the above formulas (5) to (8) include the compounds shown below.

(C) A component is not limited to 1 type, You may use 2 or more types simultaneously.
The component (C) is used in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the organopolysiloxane of the component (A). If the amount is too small, the expected adhesiveness cannot be obtained. On the other hand, if the amount is too large, the mechanical properties of the resulting rubber are inferior and the cost is disadvantageous.

  At least one filler as component (D) is a reinforcing and non-reinforcing filler for imparting good chemical resistance to the composition and imparting rubber physical properties. This filler includes surface-treated / untreated fumed silica, precipitated silica, wet silica, carbon powder, talc, bentonite, heavy calcium carbonate, colloidal calcium carbonate, zinc carbonate, magnesium carbonate, surface treatment, no Examples of the treatment include calcium oxide, zinc oxide, magnesium oxide, aluminum oxide, and aluminum hydroxide.

  Component (D) is used in an amount of 1 to 300 parts by weight, preferably 5 to 200 parts by weight, per 100 parts by weight of component (A). If it is less than 1 part by mass, sufficient chemical resistance and rubber strength cannot be obtained. If it exceeds 300 parts by mass, the mixing properties of the composition are deteriorated and the mechanical properties of the resulting rubber properties are also deteriorated.

Moreover, in order to further improve adhesiveness, the composition of this invention can mix | blend (E) the silane coupling agent shown by following General formula (9), and / or its partial hydrolyzate.
R ⁹ _g R ¹⁰ _h Si (OR ⁸ ) _4-gh (9)
(Wherein R ⁸ is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, particularly preferably 1 to 2 carbon atoms, and R ⁹ is independently a nitrogen atom, a sulfur atom, or an oxygen atom. It is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 7 carbon atoms, including one or more selected, and R ¹⁰ has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. (It is an unsubstituted or halogen atom substituted monovalent hydrocarbon group, g is 1 or 2, h is 0 or 1, and g + h is 1 or 2.)

In the above formula (9), examples of R ⁸ include a methyl group, an ethyl group, a propyl group, and a butyl group, and a methyl group and an ethyl group are preferable.
R ⁹ can be exemplified by the same as R ⁵ described above. R ¹⁰ can be exemplified by the same as R ⁶ described above.

As specific examples of the silane coupling agent of component (E), a large number of silane coupling agents can be exemplified. As such silane coupling agents, known ones are preferably used, ) Acrylic silane coupling agent, epoxy silane coupling agent, amino silane coupling agent, mercapto silane coupling agent and the like are exemplified. Specifically, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltri Epoxy group-containing silane coupling agents such as ethoxysilane, (meth) acrylic group-containing silane coupling agents such as 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane N- (2-aminoethyl) -3-amino Amino group-containing silane coupling agents such as propyltrimethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, Examples include ureido group-containing silane coupling agents such as ureidopropyltriethoxysilane, mercapto group-containing silane coupling agents such as 3-mercaptopropyltrimethoxysilane, and isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane. Can be mentioned.
(E) When mix | blending a component, (E) component is not limited to 1 type, You may use 2 or more types simultaneously.

  The blending amount in the case of blending the silane coupling agent of component (E) and its partial hydrolyzate, the mass ratio of component (C) and component (E) is 0.70 ≦ (C) component / [( C) component + (E) component] <1.0, particularly 0.8 ≦ (C) component / [(C) component + (E) component] <1.0. Within this range, the adhesiveness of the composition is further improved, the change with time is suppressed / suppressed, and the curability is not lowered.

In the composition of the present invention, in addition to the above components, known additives in the room temperature curable organopolysiloxane composition may be used within a range not impairing the object of the present invention. As the additive, an organic tin compound, a curing catalyst such as an organic titanium compound, a polyether as a thixotropic agent, a silicone oil, isoparaffins, trimethylsiloxy units and SiO ₂ units as the crosslinking density improver as a plasticizer Examples include reticulated polysiloxanes, pigments, dyes, colorants such as fluorescent brighteners, bioactive additives such as fungicides, antibacterial agents, marine organism repellents, and phenyl silicone oils as bleed oil Surface modifiers such as fluorosilicone oil, organic liquid incompatible with silicone, solvents such as toluene, xylene, solvent volatile oil, cyclohexane, methylcyclohexane, and low boiling point isoparaffin can also be added.

  The room temperature curable organopolysiloxane composition of the present invention can be obtained by mixing the components (A) to (D) and, if necessary, the component (E) and various additives in a state where moisture is blocked. The obtained composition is stored as it is in a closed container, and is cured into a rubbery elastic body by being exposed to moisture in the air at the time of use, so-called one-packaging room temperature curable organopolysiloxane composition or other components at the time of use. It can be used as a so-called two-packaging room temperature curable organopolysiloxane composition that cures to a rubbery elastic body by mixing with.

  In addition, the room temperature curable organopolysiloxane composition obtained in the present invention can be expected to be applied to industries that require initial curability maintenance. Among them, it is particularly effective for automotive oil seal applications.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Example 1]
(A) 10 parts by mass of fumed silica whose surface is treated with dimethyldichlorosilane (D) on 100 parts by mass of polydimethylsiloxane whose end at 23 ° C. has a viscosity of 20,000 mPa · s blocked with a silanol group, heavy After adding 100 parts by mass of calcium carbonate and mixing with a mixer, (B) 10 parts by mass of vinyltris (methylethylketoxime) silane was added and mixed thoroughly under reduced pressure. Further, (C) 3-aminopropyltris (methylethylketo) Oxime) 2 parts by mass of silane, 0.8 parts by mass of (E) 3-aminopropyltrimethoxysilane and 0.1 parts by mass of dioctyltin versatate were added and mixed thoroughly under reduced pressure to obtain Sample 1 (here (C) component / [(C) component + (E) component] = 0.71 (mass ratio).).

[Example 2]
(A) 10 parts by mass of fumed silica whose surface is treated with dimethyldichlorosilane (D) on 100 parts by mass of polydimethylsiloxane whose end at 23 ° C. has a viscosity of 20,000 mPa · s blocked with a silanol group, heavy After adding 100 parts by mass of calcium carbonate and mixing with a mixer, (B) 10 parts by mass of vinyltris (methylethylketoxime) silane was added and mixed thoroughly under reduced pressure. Further, (C) 3-aminopropyltris (methylethylketo) Oxime) 2 parts by mass of silane and 0.1 parts by mass of dioctyltin versatate were added and mixed thoroughly under reduced pressure to obtain Sample 2 (where (C) component / [(C) component + (E) component) ] = 1.0 (mass ratio).

[Example 3]
(A) 10 parts by mass of fumed silica whose surface is treated with dimethyldichlorosilane (D) on 100 parts by mass of polydimethylsiloxane whose end at 23 ° C. has a viscosity of 20,000 mPa · s blocked with a silanol group, heavy After adding 100 parts by mass of calcium carbonate and mixing with a mixer, (B) 10 parts by mass of vinyltris (methylethylketoxime) silane is added and thoroughly mixed under reduced pressure. Further, (C) 3- (2-aminoethyl) Add 2 parts by weight of amino) propyltris (methylethylketoxime) silane, 0.5 parts by weight of (E) 3- (2-aminoethylamino) propyltrimethoxysilane, 0.1 parts by weight of dioctyltin versatate, and complete under reduced pressure To obtain a sample 3 (where (C) component / [(C) component + (E) component]) = 0.80 (mass ratio). .).

[Example 4]
(A) 10 parts by mass of fumed silica whose surface is treated with dimethyldichlorosilane (D) on 100 parts by mass of polydimethylsiloxane whose end at 23 ° C. has a viscosity of 20,000 mPa · s blocked with a silanol group, heavy After adding 100 parts by weight of calcium carbonate and mixing with a mixer, (B) 10 parts by weight of vinyltris (methylethylketoxime) silane is added and thoroughly mixed under reduced pressure, and (C) N- (2-aminoethyl) is further added. ) -3-Aminopropyltris (methylethylketoxime) silane and chloropropyltris (methylethylketoxime) silane 2 mass parts, (E) 3-aminopropyltrimethoxysilane 0.5 mass parts, dioctyltin versatate 0.1 Part by mass was added and thoroughly mixed under reduced pressure to obtain Sample 4 (where (C) component / Component (C) + (E) component] = 0.80 (mass ratio).).

[Example 5]
(A) 10 parts by mass of fumed silica whose surface is treated with dimethyldichlorosilane (D) on 100 parts by mass of polydimethylsiloxane whose end at 23 ° C. has a viscosity of 20,000 mPa · s blocked with a silanol group, heavy After adding 100 parts by weight of calcium carbonate and mixing with a mixer, (B) 10 parts by weight of vinyltris (methylethylketoxime) silane is added and thoroughly mixed under reduced pressure. Further, (C) 3-methacryloxypropyltris ( 2 parts by mass of a reaction product of methylethylketoxime) silane and N- (2-aminoethyl) -3-aminopropyltris (methylethylketoxime) silane, (E) 0.5 part by mass of 3-aminopropyltrimethoxysilane, dioctyltin Add 0.1 parts by weight of versatate and mix thoroughly under reduced pressure to obtain Sample 5 (here Component (C) / [the component (C) + (E) component] = 0.80 (mass ratio).).

[Example 6]
In Example 1, instead of (B) vinyltris (methylethylketoxime) silane, (B) methyltris (methylethylketoxime) silane was prepared under the same conditions except that 6 parts by mass was obtained, and sample 6 was obtained (here (C) component / [(C) component + (E) component] = 0.71 (mass ratio).)

[Comparative Example 1]
The same conditions as in Example 1 except that (C) 3-aminopropyltris (methylethylketoxime) silane was not added and the amount of (E) 3-aminopropyltrimethoxysilane was changed to 2.8 parts by mass. Sample 8 was obtained (where (C) component / [(C) component + (E) component] = 0 (mass ratio)).

  Using the samples (room temperature curable organopolysiloxane composition) obtained in the above examples and comparative examples, tack-free time, slump property, curing speed, initial seal property, rubber physical property (hardness) by the following test methods , Elongation at break, tensile strength), shear adhesion, storage deterioration test, and chemical resistance test. These results are shown in Table 1.

[Test method]
The tack free time (touch touch drying time) was measured according to the method specified in JIS A 5758. The slump property test was measured according to JIS A 5758.
In the curing speed test, a glass petri dish having an inner diameter of 10 mm was filled with the sample, and the thickness cured from the portion exposed to air after 23 ° C. and 50% RH × 1 day was measured.

  In the initial sealability test, the pressure resistance test was performed using a pressure vessel similar to the flange pressure vessel for pressure resistance specified in JIS K 6820 as a test apparatus. The pressure vessel comprises an upper vessel having an upper flange having an inner diameter of 58 mm, an outer diameter of 80 mm, and a height of 10 mm, and a lower vessel having a lower flange of the same size as the upper flange, and the inner side of the seal surface of the lower flange An annular cutout having a width of 3 mm and a depth of 3 mm is provided along the circumference of the edge. The sealing surface of the lower flange was washed with toluene. Thereafter, the sample was applied in the form of a bead to the center portion of the lower seal surface. Immediately after application, the upper container was placed on the lower container so that the sealing surfaces of the upper flange and the lower flange were in contact with each other, and a 20.50 mm iron spacer was installed and four fastening bolts were assembled. The spacer causes a gap of 0.5 mm between the seal surfaces, which is a so-called accelerated test that makes the pressure test more severe. After curing at 23 ° C. and 50% RH for 30 minutes, a gas was inserted from the upper pressure port, and the gas pressure that the sealant could withstand was defined as the seal strength.

The sample was poured into a 2 mm mold and cured at 23 ° C. and 50% RH for 4 days to obtain a rubber sheet having a thickness of 2 mm. Rubber physical properties were measured from a 2 mm thick rubber sheet according to JIS K 6249.
Also, using this sample and an adherend (aluminum, iron) having a width of 25 mm and a length of 100 mm, it was cured for 4 days at 23 ° C. and 50% RH, and was shear bonded with an adhesion area of 2.5 mm ² and an adhesion thickness of 1 mm. A test body was prepared and the shear adhesive strength was measured according to JIS K 6249.

  In the storage deterioration test, the sample was allowed to stand in an uncured state at 70 ° C. for 7 days under sealed conditions, and then the same test as in the initial stage of production was performed to confirm performance deterioration. In the initial sealability test, the seal strength after the initial stage of production and after the storage deterioration was compared, and the ratio of the seal strength after the storage deterioration relative to the initial stage of manufacture was shown in Table 1 as the retention rate. A composition having a value of 60% or more has good initial sealing properties.

  In addition, in order to confirm the chemical resistance performance of the sample cured product, the obtained 2 mm thick rubber sheet and shear adhesion test specimen were immersed in engine oil at 120 ° C. for 10 days, and then the same test as in the initial stage of production was performed. The chemical resistance was confirmed.

Claims (4)

(A) 100 parts by mass of an organopolysiloxane represented by the following general formula (1),
HO (SiR ¹ ₂ O) _a H (1)
(Wherein R ¹ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ¹ may be the same or different from each other. A is 10 or more. (It is an integer.)
(B) A silane compound having at least two ketoxime groups represented by the following general formula (2) and / or a partial hydrolyzate thereof in an amount of 0.1 to 30 parts by mass,
R ³ _b Si (ON = CR ² ₂ ) _4-b (2)
(In the formula, R ² is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ³ is a methyl group and / or vinyl group, and b is 0, 1 or 2. )
(C) A silane compound represented by the following general formula (3), a reaction product of a silane compound represented by the following general formula (3) and a silane compound represented by the following general formula (4), or a partial hydrolyzate thereof. Or 0.1-10 parts by mass of a mixture thereof,
R ⁵ _c R ⁶ _d Si (ON = CR ⁴ ₂ ) _4-cd (3)
(In the formula, R ⁴ is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and R ⁵ is independently selected from one or more selected from a nitrogen atom, a sulfur atom, and an oxygen atom. An unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, R ⁶ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, c is 1 or 2, and d is 0 or 1, and c + d is 1 or 2.)
(XR ⁷ ) _e R ⁶ _f Si (ON = CR ⁴ ₂ ) _4-ef (4)
Wherein R ⁴ and R ⁶ are the same as above, R ⁷ is independently an unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, and X is a chlorine atom, a bromine atom or a (meth) acryl group. E is 1 or 2, f is 0 or 1, and e + f is 1 or 2.)
(D) A room temperature-curable organopolysiloxane composition comprising 1 to 300 parts by mass of at least one filler. The room temperature-curable organopolysiloxane composition according to claim 1, wherein the component (C) is selected from the compounds represented by the following general formulas (5) to (8).

(In the formula, R ⁴ , R ⁶ , R ⁷ , d, and f are the same as above.) Further, (E) a silane coupling agent represented by the following general formula (9) and / or a partial hydrolyzate thereof, the mass ratio of the component (C) and the component (E) is 0.70 ≦ (C 3) The room temperature-curable organopolysiloxane composition according to claim 1 or 2, which is contained within a range where component / [component (C) + component (E)] <1.0.
R ⁹ _g R ¹⁰ _h Si (OR ⁸ ) _4-gh (9)
(In the formula, R ⁸ is independently a monovalent hydrocarbon group having 1 to 6 carbon atoms, and R ⁹ is independently 1 or 2 or more carbon atoms selected from a nitrogen atom, a sulfur atom, and an oxygen atom. 10 is an unsubstituted or substituted monovalent hydrocarbon group having 10 to ¹⁰ carbon atoms, R ¹⁰ is an unsubstituted or halogen atom-substituted monovalent hydrocarbon group having 1 to ¹⁰ carbon atoms, g is 1 or 2, h is 0 or 1, g + h is 1 or 2.)   The automobile oil seal obtained by hardening the composition of any one of Claims 1-3.