JP3350347B2 - Room temperature curable composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a room temperature curable composition which is easily cured by the action of moisture,
In particular, the present invention relates to a curable composition capable of forming a cured product having excellent solvent resistance, chemical resistance, heat resistance, and cold resistance.

[0002]

2. Description of the Related Art Conventionally, a so-called room temperature curable composition which is stored stably while maintaining fluidity under airtight conditions, and which cures at room temperature under the action of moisture in the atmosphere to become a rubber elastic body has been known. I have. This curable composition is widely used as a sealing material, a coating material, an adhesive, and the like in the construction industry, the machine industry, or the electric industry.

[0003]

However, none of the conventionally known room temperature curable compositions can form a cured product excellent in all the properties of solvent resistance, chemical resistance, heat resistance and cold resistance. . For example, an organopolysiloxane composition curable at room temperature can form a cured product having excellent heat resistance and cold resistance, but the cured product can satisfy solvent resistance and chemical resistance. is not. Further, other room temperature curable compositions are inferior in heat resistance. Therefore, an object of the present invention is to
It is an object of the present invention to provide a room temperature curable composition capable of forming a cured product excellent in all of solvent resistance, chemical resistance, heat resistance and cold resistance.

[0004]

According to the present invention, a room temperature curable composition comprising the following (A) and (B):
A composition is provided. (A) The following general formula (1)

[0005]

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[0006] wherein, a is an integer of 1 or more, b is 2 or 3, R ¹ may be the same or different, unsubstituted or substituted monovalent hydrocarbon group, R ² is also the same An unsubstituted or substituted divalent hydrocarbon group, X
The hydrolyzable group, Rf is selected from the group consisting be the same or different have good <br/>, divalent perfluoroalkylene group or a divalent perfluoroalkyl ether group, Q is the following formula (2) or
A siloxane group represented by the following formula (3) (wherein, R ³ and R ⁴ may be the same or different and each is an unsubstituted or substituted monovalent hydrocarbon group )] 100 parts by weight of compound , (B) 500 parts by weight or less of filler .

[0007]

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[0008]

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As described above, the equation (2) or (3)
Wherein the siloxane groups, R ³ and R ^4, but it may also be the same or different each is a substituted or unsubstituted monovalent hydrocarbon group.

Base Component The curable composition of the present invention has, as a base component, the fluorine-containing organosilicon compound represented by the formula (1) of the component (A) . That is, this fluorine-containing organosilicon compound has a plurality of hydrolyzable groups at both ends of a molecular chain, and when this comes into contact with moisture in the air, hydrolysis and condensation occur to cure the rubber elastic body. It forms things.

In the above formula (1), the unsubstituted or substituted monovalent hydrocarbon group R ¹ is an alkyl group such as a methyl group, an ethyl group or a propyl group; a cycloalkyl group such as a cyclohexyl group; An alkenyl group such as an isopropenoxy group; an aryl group such as a phenyl group or a tolyl group; an aralkyl group such as a benzyl group or a phenylethyl group; and a group in which part or all of the hydrogen atoms of these groups have been substituted with halogen or the like. For example, 3,3,3-trifluoropropyl group, 6,6,6,5,5,4,4,3,3
-Nonafluorohexyl group, chloromethyl group, 3-chloropropyl group and the like. In the present invention, particularly preferred R ¹ is a methyl group, a phenyl group,
3,3-trifluoropropyl group.

An unsubstituted or substituted divalent hydrocarbon group R ²
Examples include alkylene groups such as methylene group, ethylene group, propylene group and butylene group, arylene groups such as phenylene group and tolylene group, and groups in which part or all of the hydrogen atoms of these groups are substituted with halogen or the like. can do. In the present invention, particularly preferred R ² is an ethylene group or a propylene group.

Further, examples of the hydrolyzable group X include an alkoxy group, an alkenyloxy group, an oximo group, a carboxyl group, an amino group and an aminoxy group. As an alkoxy group, a methoxy group, an ethoxy group, an alkenyloxy group as an isopropenoxy group, an oximo group as a methylethylketooximo group, a carboxyl group as an acetoxy group, an amino group as a diethylamino group,
Examples of the aminoxy group include a diethylaminoxy group and the like. X particularly preferable in the present invention is a methoxy group, an ethoxy group, or an isopropenoxy group.

The fluorine-containing group Rf is a divalent perfluoroalkylene group or a divalent perfluoroalkyl ether group. As the divalent perfluoroalkylene group, those having 4 to 8 carbon atoms are preferable, and particularly preferable ones are
—C ₄ F ₆ — and —C ₆ F ₁₂ —. The divalent perfluoroalkyl ether group has 6 to 100 carbon atoms.
Are preferred, and particularly preferred are as follows.

[0015]

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Q is a siloxane group represented by the above formula (Z) or (3), and the unsubstituted or substituted monovalent hydrocarbon groups R ³ and R ^{4 in the} formula (2) or (3) Examples of the group include those exemplified for R ¹ above.
Particularly preferred are a methyl group, an ethyl group, a propyl group, a phenyl group and a 3,3,3-trifluoropropyl group.

Further, in the general formula (1), a is a number of 1 or more, and preferably 25% of the fluorine-containing organosilicon compound.
Viscosities between 25 and 500,00 cSt, especially 1,
The number is in the range of 000 to 100,000 cSt. If the viscosity is lower than 25 cSt, the resulting cured product tends to have unsatisfactory properties such as mechanical strength, and if it is higher than 500,000 cSt, the workability of the composition tends to decrease. In addition, b is the number of functional groups at both ends of the molecular chain, and it is necessary that b is 2 or 3 in order for the fluorine-containing organosilicon compound to exhibit appropriate room temperature curability.

Component (B) in the curable composition of the present invention
The filler may be blended in an amount of not more than 500 parts by weight, preferably 10 to 100 parts by weight, per 100 parts by weight of the fluorine-containing organosilicon compound of the component (A) for reinforcement, weight increase, and the like. The fillers include fumed silica, precipitated silica, carbon powder, titanium dioxide, aluminum oxide, quartz powder, reinforcing agents such as talc, sericite and bentonite, and fibrous fillers such as asbestos, glass fiber and organic fiber. Materials can be exemplified.

A condensation curing catalyst such as an organotin compound or an organotitanium compound; an oil resistance improver such as potassium methacrylate; a colorant; a heat resistance improver such as red iron oxide and cerium oxide; a cold resistance improver; A dehydrating agent; an adhesion improver such as γ-aminopropyltriethoxysilane; and the like, which are excellent in all of solvent resistance, chemical resistance, heat resistance and cold resistance. It is used according to the purpose in such an amount that the purpose of the present invention of forming a cured product is not impaired.

Curable Composition The curable composition of the present invention is prepared as a one-part room temperature curable composition by uniformly mixing predetermined amounts of the above-mentioned components in a dry atmosphere. When this curable composition is exposed to air, a crosslinking reaction by hydrolysis-condensation proceeds due to moisture in the air, and a cured rubber elastic body is formed. The resulting cured product has an extremely high fluorine content in the fluorine-containing organosilicon compound as a base component in the composition, and has a property of any of solvent resistance, chemical resistance, heat resistance and cold resistance. Is also excellent.

The curable composition is suitable as a sealing material and a coating material in the construction and civil engineering industries, and is also very useful as a bonding material for electric and electronic parts, a sealing material and a FIPG material in the automobile industry. .

[0022]

EXAMPLES Examples of the present invention will be described below, in which all parts are parts by weight and the viscosities are values measured at 25 ° C.

Example 1 The following formula (4):

[0024]

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(Where Rf and Q are the following formulas (5) and (6)
Indicated by )

[0026]

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[0027]

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Mixture of

Polymer 100 having a viscosity of 21,000 cp and a methoxy group content of 0.014 mol / 100 g
g of MT carbon and 20 g of MT carbon, and passed through a three-roll mill once to obtain a composition I. This composition I is 2 m thick
m, and left in an atmosphere of a temperature of 20 ° C. and a relative humidity of 55% for 14 days, the sheet was cured to become a rubber elastic body. The composition I was stable for at least 6 months at room temperature in a sealed state. After the lapse of 6 months, the composition I was molded into a sheet having a thickness of 2 mm and cured under the same conditions as above. Became a body. The rubber properties at the initial stage and after 6 months were measured according to the method of JIS-C-2123, and the results shown in Table 1 below were obtained.

[0030]

[Table 1]

Example 2 100 g of the same polymer as used in Example 1, MT
20 g of carbon, 2 g of fumed silica, 0.3 g of dibutyltin laurate, 2 g of vinyltrimethoxysilane, γ-
1 g of aminopropyltriethoxysilane was mixed, and the mixture was passed through a triple roll once to obtain a composition II. When this composition II was cured in the same manner as in Example 1, a rubber elastic body was obtained. When the physical properties of this rubber elastic body were measured in the same manner as in Example 1, the results shown in Table 2 were obtained.

[0032]

[Table 2]

The results of measuring the solvent resistance, chemical resistance, heat resistance, and cold resistance of the cured products obtained from the compositions I and II of the above Examples are shown in Tables 3, 4 and 5, and It is shown in Table 6. In addition, heat resistance and cold resistance were measured only for the composition II.

[0034]

[Table 3]

Test conditions: The cured product was immersed in each solvent at 25 ° C. for 7 days to evaluate the volume change rate. The fluoro rubber used for comparison was Viton E-60C manufactured by DuPont.

[0036]

[Table 4]

Test conditions: Evaluation was made based on the rate of change in volume when the cured product was immersed in each chemical solution at 25 ° C. for 7 days. The silicone rubber used for comparison was KE- manufactured by Shin-Etsu Chemical Co., Ltd.
951

[0038]

[Table 5]

[0039]

[Table 6]

The cold resistance test was performed by the following method.
The test piece was cooled to −70 ° C. in dry ice / ethanol using a Geman torsion tester manufactured by Ueshima Seisakusho,
The temperature was raised at a rate of min. At this time, the stiffness at each temperature was measured, and the temperatures at which the stiffness at room temperature became 2, 5, 10, and 100 times the T ₂ ,
The values are shown as T ₅ , T ₁₀ , and T ₁₀₀ .

[0041]

According to the room temperature curable composition of the present invention, a cured product having excellent solvent resistance, chemical resistance, heat resistance and cold resistance can be formed.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 77/00-77/62

Claims (2)

(57) [Claims] 1. A room temperature curable composition comprising the following (A) and (B):
Composition. (A) General formula (1) [In the formula, a is an integer of 1 or more, b is 2 or 3, R ¹
May be the same or different, and an unsubstituted or substituted monovalent hydrocarbon group and R ² may be the same or different;
Unsubstituted or substituted divalent hydrocarbon group, X is a hydrolyzable group, Rf is selected from the group consisting be the same or different have good, divalent perfluoroalkylene group or a divalent perfluoroalkyl ether group, Q is formula (2) or expressed by the following formula (3)
A siloxane group (wherein, R ³ and R ⁴ may be the same or different and each is an unsubstituted or substituted monovalent hydrocarbon group ), 100 parts by weight of a fluorine-containing organosilicon compound represented by the formula: Formula 2 Embedded image (B) Filler 500 parts by weight or less . 2. A cured product obtained by curing the composition of claim 1.