JP5359406B2 - Room temperature curable organopolysiloxane composition, method for producing the same, and automobile oil seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a room temperature curable organopolysiloxane composition which shows less change with time and provides a cured product excellent in oil resistance, a method for producing the same, and an automobile oil seal. <P>SOLUTION: The method for producing the room temperature curable organopolysiloxane composition, which includes (A) 100 pts.mass of a diorganopolysiloxane which has a molecular chain whose both ends are blocked with hydroxy groups and/or hydrolyzable groups and a viscosity at 25&deg;C of 25-1,000,000 mPa s, (B) 0.5-30 pts.mass of an organosilane containing three or more hydrolyzable groups in one molecule (except a silane coupling agent) and/or a partial hydrolysate thereof, (C) 0.1-20 pts.mass of a silane coupling agent and/or a partial hydrolysate thereof, and (D) 1-500 pts.mass of a basic filler, includes adding the components (B) and (C), which are previously aged, to the components (A) and (D). <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a novel room temperature curable organopolysiloxane composition excellent in oil resistance, and more particularly to the composition useful as a FIPG (Formed In Place Gaskets) material for automobiles, a method for producing the composition, and an automobile oil seal.

  Conventionally, oil-resistant gaskets or packing materials made of cork, organic rubber, asbestos and the like have been used as materials for sealing engine oil, gear oil, automatic transmission fluid, and the like of automobile engine parts. However, these sealing materials have the disadvantages of complicated inventory management and complicated work processes, and lack of reliability in sealing performance. Therefore, the FIPG method using a room temperature curable organopolysiloxane composition having excellent adhesion and heat resistance has been adopted, and has reached the present.

  A room temperature curable silicone rubber composition used around an automobile engine must have resistance to automobile oil. Decreased rubber properties and adhesiveness of the cured product due to oil resistance deterioration lead to oil bleeding from the seal site and oil leakage. In general, engine oils contain acidic additives such as metal phosphates and metal phosphites as extreme pressure additives, and as a result, the rubber properties of the cured products deteriorate or the adhesion decreases. It has been found to be. Therefore, oxides, hydroxides or carbonates such as calcium, zinc, and magnesium are usually added to the composition for the purpose of neutralizing acidic additives. In addition, there is also known a technique for increasing the crosslinking density of a cured product in advance so that the rubber physical properties of the cured product do not deteriorate even when the polymer chain of the cured product is cleaved by an acidic additive.

  However, in recent years, automobile oil has become more and more sophisticated, the amount of the above-mentioned phosphorus-based acidic additives increased, and sulfur or molybdenum-based compounds that cannot be neutralized with the above oxides, hydroxides or carbonates have been added. It has come to be. The addition of the oxides, hydroxides or carbonates or the improvement of the crosslinking density is reaching a level where the oil resistance is not satisfied.

  Furthermore, recent automobile oils tend to use low-viscosity base oils for the purpose of reducing fuel consumption. This is because the low-viscosity automotive lubricating oil has low resistance and does not hinder the movement of the movable part, resulting in a direction of increasing the fuel consumption of the engine. However, in an automotive oil using a low-viscosity base oil, in addition to the deterioration of the silicone rubber due to the acidic component described above, the influence of the rubber swelling cannot be ignored. The swelling of rubber by automobile oil has an effect of promoting the penetration of the acidic component into the rubber in addition to the decrease in mechanical strength.

  One technique for solving this is the use of anisotropic fillers. The anisotropic filler has an effect of increasing resistance to deformation of the cured silicone rubber and suppressing swelling due to a lubricating oil, a solvent and the like. In JP-A-10-17773 (Patent Document 1), for the purpose of improving oil resistance, flaky inorganic powder having an average particle size of 50 μm or less, preferably talc, mica, kaolin and alumina having an average particle size of 50 μm or less, It has been proposed to use talc and alumina preferably having an average particle size of 50 μm or less.

  However, it has been found that talc, mica, kaolin, and the like have a high surface activity, so that when they are added to the composition, the viscosity is extremely increased and workability is greatly reduced. Further, since it is an intercalation compound, it has been found that ionic substances such as sodium and potassium may diffuse into the rubber and cause problems such as thickening and gelling of the composition.

  Thus, in order to improve oil resistance, it is achieved by a method of adding a large amount of various fillers and additives, but at the same time, the change of the composition with time is increased, which is a big problem.

Japanese Patent Laid-Open No. 10-17773

  The present invention has been made in view of the above circumstances, and can provide a cured product having little change over time and excellent in oil resistance, and particularly suitable as an automotive FIPG material, and a method for producing the same. An object is to provide an automobile oil seal.

As a result of intensive studies on the organosilane compound having a hydrolyzable group used in the crosslinking agent and the adhesion assistant in order to achieve the above object, the present inventors have found that the curing agent, the adhesion assistant and the necessity. Accordingly, it has been found that by curing the curing catalyst in advance (aging refers to mixing in advance at a constant temperature and time), a cured product having almost no change with time and excellent in oil resistance can be obtained.
That is, the present inventors investigated the cause of the change over time of the composition, and as a result, when the hydrolyzable groups of the organosilane compound used for the crosslinking agent and adhesion aid in the composition are different, these Confirmed that the reaction took place slowly over time. This is the cause of changes in curability, adhesiveness, etc., and as a result of diligent investigations on countermeasures, organosilanes are obtained over time by aging a crosslinking agent, an adhesion assistant, and a curing catalyst as necessary. It was found that the structural change of the compound was suppressed and hardly changed with time, and the present invention was made.

Accordingly, the present invention provides a room temperature curable organopolysiloxane composition and a method for producing the same as shown below, and an automobile oil seal.
[Claim 1]
(A) Diorganopolysiloxane in which both ends of the molecular chain are blocked with a hydroxyl group and / or a hydrolyzable group and the viscosity at 25 ° C. is 25 to 1,000,000 mPa · s: 100 parts by mass
(B) Organosilane containing 3 or more hydrolyzable groups in one molecule selected from ketoxime silanes, alkoxysilanes, acetoxysilanes, and isopropenoxysilanes (excluding silane coupling agents) ) And / or partial hydrolysates thereof:
0.5-30 parts by mass,
(C) Silane coupling agent and / or partial hydrolyzate thereof: 0.1 to 20 parts by mass,
(D) Basic filler: 1 to 500 parts by mass ,
(E) A method for producing a room temperature curable organopolysiloxane composition containing 0.01 to 10 parts by mass of a curing catalyst , wherein the components (B) , (C), and ( E ) are previously added to 20 A room temperature-curable organopolysiloxane composition characterized by adding aged product to components (A) and (D) by heating and curing under conditions of -100 ° C. for 30 minutes to 2 weeks Production method.
[Claim 2 ]
The manufacturing method according to claim 1 , wherein the basic filler is a basic filler selected from the group consisting of zinc oxide, calcium carbonate, magnesium oxide, and zinc carbonate.
[Claim 3 ]
A room temperature-curable organopolysiloxane composition produced by the method according to claim 1 or 2 .
[Claim 4 ]
An automobile oil seal obtained by curing the composition according to claim 3 .

  According to the production method of the present invention, a cured product having little change with time and excellent oil resistance is obtained, and a room temperature-curable organopolysiloxane composition particularly suitable as a FIPG material for automobiles is obtained. The cured product of the composition is effective as an automobile oil seal because of its good oil resistance.

(A) Component The (A) component of the present invention is a diorganopolysiloxane having both molecular chain ends blocked with hydroxyl groups and / or hydrolyzable groups, and a viscosity at 25 ° C. of 25 to 1,000,000 mPa · s. It is.

  The viscosity at 25 ° C. of the diorganopolysiloxane is 25 to 1,000,000 mPa · s, preferably 1,000 to 100,000 mPa · s. If the viscosity is lower than 25 mPa · s, a rubber elastic body excellent in physical and mechanical strength cannot be obtained, and if it is higher than 1,000,000 mPa · s, the viscosity of the composition becomes too high and the workability is lowered. To do. In the present invention, the viscosity can be measured with a rotational viscometer.

Examples of the diorganopolysiloxane include the following general formula (1)
HO— [R ₂ SiO] _L —H (1)
[Wherein, R is the same or different, substituted or unsubstituted monovalent hydrocarbon group, and L is a number satisfying the above viscosity range, usually an integer of 10 or more. ]
And a compound represented by the following general formula (2)
^{_{(R 1 O) n R 3}} -n Si-R 2 - (R 2 SiO) L -SiR 2 -R 2 -SiR 3-n (OR 1) n
(2)
[Wherein, R and L are as defined above, R ¹ is the same or different substituted or unsubstituted monovalent hydrocarbon group, and R ² is an oxygen atom or substituted or unsubstituted divalent hydrocarbon. And n is 2 or 3. ]
The compound shown by these is mentioned.

  R in the general formulas (1) and (2) is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, such as a methyl group or an ethyl group. Alkyl groups such as propyl group and butyl group; cycloalkyl groups such as cyclohexyl group; alkenyl groups such as vinyl group and allyl group; aryl groups such as phenyl group and tolyl group; aralkyl groups such as benzyl group and phenylethyl group; In addition, a group in which part or all of the hydrogen atoms bonded to the carbon atoms of these groups are substituted with a halogen atom, a cyano group or the like (for example, a chloromethyl group, a trifluoropropyl group, or a cyanoethyl group) can be mentioned. Among these, a methyl group, a vinyl group, a phenyl group, and a trifluoropropyl group are preferable, and a methyl group and a phenyl group are particularly preferable.

R ¹ in the general formula (2) is a monovalent hydrocarbon group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms, such as a methyl group, an ethyl group, a propyl group, or a butyl group. An alkyl group; a cycloalkyl group such as a cyclohexyl group; and an alkenyl group such as a vinyl group and an allyl group. Among these, a methyl group, an ethyl group, and a propyl group are preferable, and a methyl group and an ethyl group are particularly preferable. R ² is an oxygen atom or a substituted or unsubstituted divalent hydrocarbon group. Specifically, as the divalent hydrocarbon group, the number of carbon atoms is usually 1 to 6, preferably 1 to 3, for example, An alkylene group such as a methylene group, an ethylene group, a propylene group, or a butylene group can be mentioned. R ² is preferably an oxygen atom, a methylene group, an ethylene group or a propylene group, particularly preferably an oxygen atom or an ethylene group.

(B) component (B) component of this invention is organosilane and / or its partial hydrolyzate which contain 3 or more hydrolysable groups in 1 molecule, As a crosslinking agent in the composition of this invention It works. In addition, in this invention, (B) component does not contain the silane coupling agent of (C) component mentioned later. Examples of the hydrolyzable group possessed by the organosilane and its partial hydrolyzate include a ketoxime group, an alkoxy group, an acetoxy group, and an isopropenoxy group. The substituent other than the hydrolyzable group bonded to the silicon atom is a monovalent hydrocarbon group having 1 to 10, preferably 1 to 8 carbon atoms, and includes an alkyl group, an alkenyl group, an aryl group, and an aralkyl group. Preferably, it is a methyl group, an ethyl group, a vinyl group, or a phenyl group, and does not contain a functional group such as an amino group, an epoxy group, a styryl group, a methacryloxy group, an acryloxy group, an isocyanate group, or a mercapto group.

  Specific examples of such component (B) include tetrakis (methyl ethyl ketoxime) silane, methyl tris (dimethyl ketoxime) silane, methyl tris (methyl ethyl ketoxime) silane, ethyl tris (methyl ethyl ketoxime) silane, methyl tris (methyl isobutyl ketoxime) silane. , Ketoxime silanes such as vinyltris (methylethylketoxime) silane, alkoxysilanes such as methyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane, vinyltriethoxysilane, methyltriacetoxysilane, vinyltriacetoxysilane, etc. Acetoxysilanes, methyltriisopropenoxysilane, vinyltriisopropenoxysilane, phenyltriisopropenoxysilane, etc. Isopropenoxysilane silanes and partial hydrolyzates of these silanes. These may be used alone or in combination.

  (B) The compounding quantity of a component is the range of 0.5-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is the range of 1-15 mass parts. If the amount is less than 0.5 parts by mass, sufficient cross-linking cannot be obtained, and it is difficult to obtain a composition having the desired rubber elasticity.

(C) Component (C) component of this invention is a silane coupling agent and / or its partial hydrolyzate, and acts as an adhesion promoter in the composition of this invention. Examples of the hydrolyzable group possessed by the silane coupling agent and the partial hydrolyzate thereof include the same groups as those in the component (B), but an alkoxy group is particularly preferred. Examples of the organic group that the silane coupling agent and its partial hydrolyzate have include amino groups, epoxy groups, styryl groups, methacryloxy groups, acryloxy groups, isocyanate groups, mercapto groups, ureido groups, and the like. An amino group is particularly preferable. Moreover, the reaction product of different silane coupling agents may be sufficient. Specific examples include 3-methacryloxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (N-aminomethylbenzylamino) propyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-isocyanate Propyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, styryltrimethoxysilane, styryltriethoxysilane, styrylmethyldimethoxysilane, styrylmethyldiethoxysilane, 3-aminopropyltris (me Le ethyl ketoxime) silane, 3-glycidoxypropyltrimethoxysilane isopropenoxysilane silane, 3-glycidoxypropyl methyl di isopropenoxysilane silane, 3-ureidopropyltriethoxysilane and the like. Moreover, the reaction product of different silane coupling agents may be sufficient. In addition, although the thing whose organic group is a vinyl group is a silane coupling agent normally, it is set as the crosslinking agent of (B) component instead of (C) component in this invention.

As the silane coupling agent having an amino group as a functional group or a partial hydrolyzate thereof, a compound represented by the following formula (3) is preferable.
H ₂ N—R ³ —SiR ⁴ _a (OR ⁵ ) _3-a (3)
(Wherein R ³ is a substituted or unsubstituted divalent hydrocarbon group which may contain an oxygen atom, a nitrogen atom or a sulfur atom, and R ⁴ and R ⁵ are substituted or unsubstituted monovalent hydrocarbon groups. A represents 0 or 1.)

In the above formula, R ³ is a substituted or unsubstituted divalent hydrocarbon group which may contain an oxygen atom, a nitrogen atom, or a sulfur atom, and specifically includes, for example, a methylene group, an ethylene group, a propylene group, a butylene group. And an alkylene group having 1 to 8 carbon atoms such as a hexene group; —C ₃ H ₆ —NH—C ₂ H ₄ —, —C ₃ H ₆ —NH—C (═O) —.

R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group Alkyl groups such as octadecyl group; cycloalkyl groups such as cyclopentyl group and cyclohexyl group; alkenyl groups such as vinyl group, allyl group, butenyl group, pentenyl group, hexenyl group; phenyl group, tolyl group, xylyl group, α-, aryl groups such as β-naphthyl group; aralkyl groups such as benzyl group, 2-phenylethyl group, 3-phenylpropyl group; and some or all of hydrogen atoms of these groups are F, Cl, Br, etc. Examples of groups substituted by halogen atoms or cyano groups, such as 3-chloropropyl group, 3,3,3-trifluoropropyl group, 2-cyanoethyl group, etc. It can be. Among these, a methyl group and an ethyl group are preferable.

R ⁵ is a substituted or unsubstituted monovalent hydrocarbon group, and examples thereof are the same as those described above for R ⁴ , but an alkyl group having 1 to 6 carbon atoms is particularly preferable.

  As the aminosilane compound, an amine-based silane coupling agent known in the art is preferably used. Specific examples include γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane, ethylenediaminopropyltrimethoxysilane, ethylenediaminopropyltriethoxysilane. Examples include silane, ethylenediaminopropylmethyldimethoxysilane, ethylenediaminopropylmethyldiethoxysilane, α-aminopropyltrimethoxysilane, and the like.

  The amount of component (C) is 0.1 to 20 parts by weight, preferably 0.2 to 15 parts by weight, per 100 parts by weight of organopolysiloxane of component (A). When the amount is less than 0.1 parts by mass, sufficient adhesion cannot be obtained, and when it exceeds 20 parts by mass, it is economically disadvantageous.

In the present invention, the above components (B) and (C) and, if necessary, further aged (E) component described later in advance are added to the (A) component and the (D) component.
(B) Component, (C) component, and, if necessary, (E) component aging method Since each component is hydrolyzable, it is preferable to measure a predetermined amount in a closed container and heat cure. The heating temperature is room temperature (20 ° C.) to 100 ° C., preferably 40 to 80 ° C., and the heating time is 30 minutes or more, preferably 1 hour or more. The upper limit of the time is not particularly limited, but in consideration of work efficiency, it is preferably within 2 weeks, particularly within 1 week. If the temperature is lower than room temperature, sufficient ripening takes a long time and the efficiency may be deteriorated. If the temperature is higher than 100 ° C., a pressurized state may occur during the ripening, which may be dangerous. Moreover, there exists a possibility that sufficient aging cannot be performed as it is less than 30 minutes. In particular, when it is aged by heating, it may be 30 minutes or longer, but when it is aged at room temperature, it is preferably aged for 1 hour or longer.

(D) Component As a basic filler of (D) component, zinc carbonate, zinc oxide, magnesium oxide, calcium carbonate, etc. are mentioned. The oil resistance can be further improved by using the above basic filler in combination.
The compounding quantity of a basic filler is 1-500 mass parts per 100 mass parts of (A) component, Preferably it is 10-300 mass parts, Most preferably, it is 50-200 mass parts. If the blending amount is too small, the neutralizing effect of the acidic component is diminished and the oil resistance is lowered, and if it exceeds 500 parts by mass, the viscosity of the composition becomes too high. descend.

(E) component In this invention, it is preferable to mix | blend (E) curing catalyst further. The (E) component curing catalyst acts as a catalyst for the reaction of the component (A) with the components (B) and (C) and the curing reaction by hydrolysis of the composition in the composition of the present invention. Specific examples of the curing catalyst include tin ester compounds such as dioctate tin, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dioctoate, dioctyltin dioctoate, dioctyltin dilaurate, and dioctyltin diversate. Compounds, tetraisopropoxy titanium, tetra n-butoxy titanium, tetrakis (2-ethylhexoxy) titanium, dipropoxy bis (acetylacetona) titanium, isopropoxy titanium bis (ethyl acetoacetate), titanium isopropoxy octylene glycol, etc. Ester or titanium chelate compounds, strong basic compounds such as tetramethylguanidine, diazabicyclononane, tetramethylguanidylpropyltrimethoxysilane, tetramethyl Illustrative examples include silanes or siloxanes containing guanidyl groups such as anidylpropylmethyldimethoxysilane, tetramethylguanidylpropyltris (trimethylsiloxy) silane, etc., but alkyl tin ester compounds, titanium chelate compounds, guanidyl groups are particularly preferred. The contained silane is preferably used. These are not limited to one kind, and may be used as a mixture of two or more kinds.

0.01-10 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for the compounding quantity of a curing catalyst, 0.05-5 mass parts is especially preferable. When the amount of the curing catalyst is too small, a sufficient catalytic effect may not be obtained, and when it is too large, the storage stability of the composition may be lowered.
In addition, as mentioned above, when using (E) component, it is preferable to age | cure together with said (B) and (C) component, and to add this to (A) and (D) component.

Other components In addition to the above components (A) to (E), various additives may be added to the composition of the present invention as long as the object of the present invention is not impaired. For example, reinforcing agents such as fumed silica, precipitated silica, quartz powder and carbon powder; fiber fillers such as glass fiber and carbon fiber; heat resistance improver such as cerium oxide; rust preventive agent; trimethoxysilyl group Examples thereof include plasticizers such as blocked dimethylpolysiloxane, liquid reinforcing agents such as reticulated polysiloxane composed of triorganosiloxy units and SiO ₂ units, pigments, dyes and the like. These use amounts are arbitrary as long as the object of the present invention is not impaired.

The composition of the present invention is a one-component room temperature curable composition, the above-described (B) component and (C) component, and an aging component (E) if necessary, and the above (A) component. , (D) component and other components as required can be obtained by drying using a mixer such as a Shinagawa mixer, a planetary mixer, a kneader, or by uniformly mixing in a reduced-pressure atmosphere. When the resulting composition is exposed to air, it is cross-linked and cured by moisture and becomes a rubbery elastic body.
The obtained composition has little change over time and can be a cured product having excellent oil resistance, and is therefore suitable for automobile oil seals. The automotive oil seal obtained by curing the composition has excellent oil resistance. Is.

  Next, an Example and a comparative example are given and this invention is demonstrated concretely. In addition, the viscosity in the following example is a measured value at 25 ° C. by a rotational viscometer.

[Example 1]
Both ends of the molecular chain are blocked with hydroxyl groups, and 100 parts by mass of dimethylpolysiloxane having a viscosity of 20,000 mPa · s, 100 parts by mass of colloidal calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., Hakujyo Hana CCR), fumed silica (produced by DEGUSSA, Erosyl R972) ) 5 parts by mass were mixed until uniform. Next, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 parts by mass of dioctyltin dilaurate and 2 parts by mass of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 1) was prepared.

[Comparative Example 1]
Both ends of the molecular chain are blocked with hydroxyl groups, and 100 parts by mass of dimethylpolysiloxane having a viscosity of 20,000 mPa · s, 100 parts by mass of colloidal calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., Hakujyo Hana CCR), fumed silica (produced by DEGUSSA, Erosyl R972) ) 5 parts by mass were mixed until uniform. Next, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 part by mass of dioctyltin dilaurate, and 2 parts by mass of 3-aminopropyltriethoxysilane were mixed under reduced pressure to obtain a room temperature curable organopolysiloxane composition (Sample 2). ) Was produced.

[Comparative Example 2]
Both ends of the molecular chain are blocked with hydroxyl groups, and 100 parts by mass of dimethylpolysiloxane having a viscosity of 20,000 mPa · s, 100 parts by mass of colloidal calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., Hakujyo Hana CCR), fumed silica (produced by DEGUSSA, Erosyl R972) ) 5 parts by mass were mixed until uniform. Next, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 parts by mass of dioctyltin dilaurate and 2 parts by mass of 3-aminopropyltriethoxysilane were added at 20 ° C. for 15 minutes, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 3) was prepared.

Next, each composition immediately after the preparation prepared in Examples and Comparative Examples was extruded into a sheet having a thickness of 2 mm, exposed to air at 23 ° C. and 50% RH, and then the sheet was subjected to the same atmosphere for 7 days. The physical properties (initial physical properties) of the cured product obtained by allowing to stand were measured according to JIS K6249. The hardness was measured using a durometer A hardness meter of JIS K6249.
A shear adhesion test specimen having an adhesion area of 2.5 mm ² and an adhesion thickness of 1 mm was prepared using an adherend (aluminum plate) having a width of 25 mm and a length of 100 mm. It was cured at 23 ° C. and 50% RH for 7 days, and measured according to JIS K6850 to confirm the shear adhesive strength and the cohesive failure rate.
In addition, as a storage test, each composition immediately after preparation prepared in Examples and Comparative Examples was put in a sealed container and left for 7 days at a temperature of 70 ° C., and left for 6 months at 23 ° C. The same measurement was performed on the sheet having a thickness of 2 mm.
These results are shown in Table 1.

[Example 2]
100 parts by mass of dimethylpolysiloxane having a molecular chain both ends blocked with hydroxyl groups and a viscosity of 20,000 mPa · s, colloidal calcium carbonate (manufactured by Maruo Calcium, Carlex 300), fumed silica (manufactured by DEGUSSA, Erosil) R972) 5 parts by mass were mixed until uniform. Next, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 parts by mass of dioctyltin dilaurate and 2 parts by mass of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 4) was prepared.

[Example 3]
100 parts by mass of dimethylpolysiloxane having both ends of the molecular chain blocked with hydroxyl groups and a viscosity of 20,000 mPa · s, 100 parts by mass of zinc oxide (manufactured by HAXITEC, 2 types of zinc oxide), fumed silica (manufactured by DEGUSSA, Erosil R972) ) 5 parts by mass were mixed until uniform. Next, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 parts by mass of dioctyltin dilaurate and 2 parts by mass of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 5) was prepared.

[Comparative Example 3]
Both ends of the molecular chain were blocked with hydroxyl groups, and 100 parts by mass of dimethylpolysiloxane having a viscosity of 20,000 mPa · s and 10 parts by mass of fumed silica (DEGUSSA, Erosyl R972) were mixed until uniform. Next, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 parts by mass of dioctyltin dilaurate and 2 parts by mass of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 6) was prepared.

[Comparative Example 4]
100 parts by mass of dimethylpolysiloxane having both ends blocked with hydroxyl groups and a viscosity of 20,000 mPa · s, 600 parts by mass of colloidal calcium carbonate (manufactured by Maruo Calcium, Carlex 300), fumed silica (manufactured by DEGUSSA, Erosil) R972) 5 parts by mass were mixed until uniform. Next, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 parts by mass of dioctyltin dilaurate and 2 parts by mass of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 7) was prepared.

  The physical properties (initial physical properties) of the cured products were measured under the same conditions as described above using the respective compositions prepared in Examples and Comparative Examples immediately after the preparation. For evaluation of oil resistance, a dumbbell was punched out from a cured product cured under the same conditions as described above, and was further immersed in engine oil [trade name: Toyota Castle Motor Oil SL 5W20] at a temperature of 120 ° C. for 240 hours. Thereafter, the physical properties after deterioration were confirmed according to JIS K6249. The results are shown in Table 2.

[Example 4]
100 parts by mass of dimethylpolysiloxane whose molecular chain both ends are blocked with hydroxyl groups and whose viscosity is 5,000 mPa · s, paraffin-treated heavy calcium carbonate (manufactured by Maruo Calcium, MC Coat P-20) 100 parts by mass, 5 parts by mass of fumed silica (Erogil R972, manufactured by DEGUSSA) was mixed until uniform. Next, 6 parts by mass of vinyltri (isopropenoxy) silane, 0.5 parts by mass of γ-tetramethylguanidylpropyltrimethoxysilane, and 2 parts by mass of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours. And mixing under reduced pressure to prepare a room temperature curable organopolysiloxane composition (Sample 8).

[Example 5]
Heavy calcium carbonate with both ends of molecular chain blocked with trimethoxysilyl group via ethylene group, viscosity of 30,000 mPa · s dimethylpolysiloxane, and paraffin-treated surface (manufactured by Maruo Calcium, MC Coat P-20) 100 parts by mass and 5 parts by mass of fumed silica (DEGUSSA, Elosil R974) were mixed until uniform. Subsequently, 5 parts by mass of methyltrimethoxysilane, 2 parts by mass of isopropoxytitanium bis (ethylacetoacetate), 0.5 part by mass of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and the mixture was subjected to reduced pressure. To prepare a room temperature curable organopolysiloxane composition (Sample 9).

[Comparative Example 5]
100 parts by mass of dimethylpolysiloxane having both ends of the molecular chain blocked with hydroxyl groups and a viscosity of 20,000 mPa · s, paraffin-treated surface of heavy calcium carbonate (manufactured by Maruo Calcium, MC Coat P-20), 100 parts by mass, 5 parts by mass of fumed silica (Erogil R972, manufactured by DEGUSSA) was mixed until uniform. Next, 6 parts by mass of vinyltri (isopropenoxy) silane, 0.5 parts by mass of γ-tetramethylguanidylpropyltrimethoxysilane, and 2 parts by mass of 3-aminopropyltriethoxysilane were mixed under reduced pressure, and room temperature curable organo A polysiloxane composition (Sample 10) was prepared.

[Example 6]
Both ends of the molecular chain are blocked with hydroxyl groups, and 100 parts by mass of dimethylpolysiloxane having a viscosity of 5,000 mPa · s, 100 parts by mass of colloidal calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., Shiruka Hana CCR), fumed silica (manufactured by DEGUSSA, Erosil R972) ) 5 parts by mass were mixed until uniform. Next, 15 parts by weight of vinyltri (methylethylketoxime) silane, 0.3 parts by weight of dioctyltin dilaurate and 2 parts by weight of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 11) was produced.

[Example 7]
Both ends of the molecular chain are blocked with a hydroxyl group, 100 parts by mass of dimethylpolysiloxane having a viscosity of 5,000 mPa · s, 100 parts by mass of basic zinc carbonate (NANOFINE-MH), fumed silica (manufactured by DEGUSSA) Erosyl R972) 5 parts by mass were mixed until uniform. Next, 15 parts by weight of vinyltri (methylethylketoxime) silane, 0.3 parts by weight of dioctyltin dilaurate and 2 parts by weight of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 12) was prepared.

[Example 8]
100 parts by mass of dimethylpolysiloxane having both ends blocked with hydroxyl groups and a viscosity of 5,000 mPa · s, 100 parts by mass of surface-treated magnesium oxide (manufactured by Kyowa Chemical Co., Ltd., Magsarat 30), fumed silica (manufactured by DEGUSSA, Erosil) R972) 5 parts by mass were mixed until uniform. Next, 15 parts by weight of vinyltri (methylethylketoxime) silane, 0.3 parts by weight of dioctyltin dilaurate and 2 parts by weight of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and mixed under reduced pressure. Thus, a room temperature curable organopolysiloxane composition (Sample 13) was prepared.

  Using each composition immediately after preparation prepared in Examples and Comparative Examples, the physical properties (initial physical properties), shear adhesive strength and cohesive failure rate of the cured product are measured under the same conditions as described above, and further measured by a storage test. went. For evaluation of oil resistance, dumbbells were punched from a cured product cured under the same conditions as described above, and further immersed in an automatic transmission oil [trade name: Toyota Castle ATF D-II] at a temperature of 120 ° C. for 240 hours. Thereafter, the physical properties after deterioration were confirmed according to JIS K6249. The same evaluation was performed for Example 1 and Comparative Example 3. The results are shown in Table 3.

[Example 9]
Both ends of the molecular chain are blocked with hydroxyl groups, and 100 parts by mass of dimethylpolysiloxane having a viscosity of 20,000 mPa · s, 100 parts by mass of colloidal calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., Hakujyo Hana CCR), fumed silica (produced by DEGUSSA, Erosyl R972) ) 5 parts by mass were mixed until uniform. Subsequently, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 part by mass of dioctyltin dilaurate, and 2 parts by mass of 3-aminopropyltriethoxysilane were added at 70 ° C. for 24 hours, and octylamine 5 was further added. Mass parts were mixed under reduced pressure to prepare a room temperature curable organopolysiloxane composition (Sample 14).
100 parts by mass of dimethylpolysiloxane whose molecular chain both ends are blocked with hydroxyl groups and whose viscosity is 5,000 mPa · s, paraffin-treated heavy calcium carbonate (manufactured by Maruo Calcium, MC Coat P-20) 100 parts by mass, 5 parts by mass of fumed silica (Erogil R972, manufactured by DEGUSSA) was mixed until uniform. Next, 3 parts by mass of cyclohexanone was added and mixed under reduced pressure to prepare a room temperature curable organopolysiloxane composition (Sample 15).
Sample 10 and sample 11 are packed into a 12-stage static mixer-equipped double cartridge, mixed and discharged with a dedicated gun, and the physical properties (initial physical properties), shear adhesive strength, and cohesive failure rate of the cured product are measured under the same conditions as above. Furthermore, the storage test and the oil resistance were evaluated.

[Comparative Example 6]
Both ends of the molecular chain are blocked with hydroxyl groups, and 100 parts by mass of dimethylpolysiloxane having a viscosity of 20,000 mPa · s, 100 parts by mass of colloidal calcium carbonate (manufactured by Shiraishi Kogyo Co., Ltd., Hakujyo Hana CCR), fumed silica (produced by DEGUSSA, Erosyl R972) ) 5 parts by mass were mixed until uniform. Next, 8 parts by mass of vinyltri (methylethylketoxime) silane, 0.05 parts by mass of dioctyltin dilaurate, 2 parts by mass of 3-aminopropyltriethoxysilane were added, and 5 parts by mass of octylamine were mixed under reduced pressure. A room temperature curable organopolysiloxane composition (Sample 16) was prepared.
A double cartridge with a 12-stage static mixer is filled with Sample 12 and Sample 11 prepared in the same manner as in Example 6 above, mixed and discharged with a dedicated gun, and the physical properties (initial physical properties) and shear of the cured product under the same conditions as above. Adhesive strength and cohesive failure rate were measured, and further storage tests and evaluation of oil resistance were performed.

  The oil resistance was immersed in engine oil [trade name: Toyota Castle Motor Oil SL 5W20] at a temperature of 120 ° C. for 240 hours. These results are shown in Table 4.

Claims (4)

(A) Diorganopolysiloxane in which both ends of the molecular chain are blocked with a hydroxyl group and / or a hydrolyzable group and the viscosity at 25 ° C. is 25 to 1,000,000 mPa · s: 100 parts by mass
(B) Organosilane containing 3 or more hydrolyzable groups in one molecule selected from ketoxime silanes, alkoxysilanes, acetoxysilanes, and isopropenoxysilanes (excluding silane coupling agents) ) And / or partial hydrolysates thereof:
0.5-30 parts by mass,
(C) Silane coupling agent and / or partial hydrolyzate thereof: 0.1 to 20 parts by mass,
(D) Basic filler: 1 to 500 parts by mass ,
(E) A method for producing a room temperature curable organopolysiloxane composition containing 0.01 to 10 parts by mass of a curing catalyst , wherein the components (B) , (C), and ( E ) are previously added to 20 A room temperature-curable organopolysiloxane composition characterized by adding aged product to components (A) and (D) by heating and curing under conditions of -100 ° C. for 30 minutes to 2 weeks Production method. The manufacturing method according to claim 1 , wherein the basic filler is a basic filler selected from the group consisting of zinc oxide, calcium carbonate, magnesium oxide, and zinc carbonate. A room temperature-curable organopolysiloxane composition produced by the method according to claim 1 or 2 . An automobile oil seal obtained by curing the composition according to claim 3 .