JPS60240761A - Organopolysiloxane composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which causes neither separation nor precipitation of Ce even when brought into contact with rubber under high temp., by blending a hydrogenpolysiloxane with a Ce-contg. organopolysiloxane. CONSTITUTION:The titled compsn. consists of an organopolysiloxane (A) of the formula (wherein R is a monovalent org. group; a is 1-3), a mixture (B) selected from among a reaction product of CeCl3 with an alkali metal silanolate contg. at least three organosiloxane units, a reaction product of a cerium org. carboxylate soluble in arom. hydrocarbon or chlorinated hydrocarbon with an alkali metal silanolate contg. at least three organopolysiloxane units and a reaction product of a cerium org. carboxylate soluble in arom. hydrocarbon or chlorinated hydrocarbon with hexamethydisilazane, and an organohydrogenpolysiloxane (C) contg. at least one hydrogen atom attached to a silicon atom. The compsn. causes neither separation nor precipitation of Ce even when brought into contact with rubber at high temp.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an organopolysiloxane composition in which cerium does not separate or precipitate even when it comes into contact with rubber at high temperatures.

[Description of prior art]

Chloroprene rubber, nitrile rubber, isoprene rubber, butadiene rubber, used in heat fixing devices for electronic copying machines.
Rolls made of rubber such as ethylene propylene rubber, ethylene propylene diene rubber, butadiene acrylonitrile rubber, ethylene acrylic rubber, and silicone rubber do not have sufficient mold releasability when used alone, and in order to further improve mold releasability, dimethyl polyethylene rubber is generally used. 180℃ in siloxane oil
, impregnation treatment is carried out for about 24 hours (Special Publications Act 1973).
8-36337).

However, since dimethylpolysiloxane oil has poor thermal stability at high temperatures, it has the disadvantage that new oil must be used each time it is impregnated.

In addition, in recent years, dimethylpolysiloxane oil added with cerium has been developed, which is called a heat-resistant oil and exhibits good thermal stability even at high temperatures of around 200°C.
-24377, Japanese Patent Publication No. 53-980, Japanese Patent Application Publication No. 51-60344, and Japanese Patent Application Publication No. 54-32563).

However, the cerium-containing dimethylpolysiloxane oil alone exhibits good thermal stability, but when used at high temperatures of around 200°C, chloroprene rubber, nitrile rubber, isoprene rubber, butadiene rubber, ethylene propylene rubber, ethylene propylene diene rubber, butadiene rubber, acrylonitrile rubber, When it comes into contact with rubber such as ethylene acrylic rubber or silicone rubber, cerium separates and precipitates, and the heat resistance is almost the same as that of additive-free dimethylpolysiloxane oil, and the effect of cerium is hardly exhibited. had.

[Purpose of the invention]

In order to solve the above-mentioned drawbacks, the present invention is characterized in that a hydrogen polysiloxane is blended into an organopolysiloxane containing cerium. 117), cerium separates even when it comes into contact with rubbers such as chloroprene rubber, nitrile rubber, isoprene rubber, butadiene rubber, ethylene propylene rubber, ethylene propylene diene rubber, butadiene rubber, acrylonitrile rubber, ethylene acrylic rubber, silicone rubber, etc. - The purpose is to provide an organopolysiloxane composition that does not precipitate.

[Description of the structure and operation of the invention]

The present invention is an organopolysiloxane composition having the following technical configuration to achieve the above object. That is,
The present invention is directed to (a) an organopolysiloxane represented by the average compositional formula Ra5iO (in the formula, R is a monovalent organic group and a is a number from 1 to 3); Reaction product of an alkali metal syralate having 7 siloxane units ■Reaction product of cerium organic carboxylate soluble in aromatic hydrocarbons or chlorinated hydrocarbons and an alkali metal syralate having 3 or more organopolysiloxane units Reaction product ■ One or more reaction products selected from the reaction products of organic carboxylic acid cerium soluble in aromatic hydrocarbons or chlorinated hydrocarbons and hexamethyldisilazane (c) 1 The present invention relates to an organopolysiloxane composition comprising an organohydrodiene polysiloxane having at least one silicon-bonded hydrogen atom in the molecule.

To explain this, the organopolysiloxane represented by the average composition formula % formula % (in the formula, R and a are as described above) of component (a) is the main component of this composition, and In the composition formula, R is a monovalent organic group. Examples of this include alkyl groups such as methyl, ethyl, propyl, and butyl; substituted alkyl groups such as 2-phenylethyl, 2-phenylpropyl, and 3.3-trifluoropropyl; Examples include aryl groups and substituted aryl groups such as vinyl, propenyl, and tolyl groups. a is a number from 1 to 3.

The molecular structure of the organopolysiloxane is not particularly limited, and any viscosity and degree of polymerization can be selected depending on the purpose and use.

The terminal group of these organopolysiloxanes is preferably a trialkylsilyl group, an alkoxy group, a hydroxyl group, an alkoxy group, or a vinyl group.

The organopolysiloxanes include trimethylsilyl end-blocked dimethylpolysiloxane, dimethylvinylsilyl end-blocked dimethylpolysiloxane, dimethylallylsilyl end-blocked dimethylpolysiloxane, phenylmethylvinylsilyl curtain-terminated u-chain phenylsiloxane-san dimethylsiloxane. copolymer, trimethylsilyl group-endblocked methylphenyldiaxane, silanol group endblocked dimethylpolysiloxane, dimethylmethoxysilyl group-blocked dimethylpolysiloxane, vinylpolysilsesquioxane, copolymer consisting of trinotylsiloxane units and SiO4/2 units Examples include polymers.

(B) Component (1) a reaction product of cerium chloride and an alkali metal silanolate having three or more organosiloxane units, (2) a cerium organic carboxylate soluble in aromatic hydrocarbons or chlorinated hydrocarbons, and three Reaction products with alkali metal silanolates having the above organopolysiloxane units; (3) reaction products between cerium organic carboxylates soluble in aromatic hydrocarbons or chlorinated hydrocarbons and hexamethyldisilazane; The selected one or a mixture of two or more is a necessary component for imparting thermal stability at high temperatures to the organopolysiloxane.

Examples of the alkali metal silanolates mentioned above include potassium silanolate and sodium silanolate, and such alkali metal silanolates include, for example, W, T, and G.
rubb, R, C, Oatoff, J, A, C, S, 7
7, 1405 (1955), or the alkali metal silanolate having silanol groups at both ends of the organopolysiloxane molecular chain thus obtained is further reacted with a linear organopolysiloxane. It is obtained by such a method as to form an alkali metal silanolate having a silanol group at only one end of the molecule. Examples of the organic group bonded to the silicon atom in the alkali metal silanolate include the groups exemplified for R in component (a).

Cerium organic carboxylate must be soluble in aromatic hydrocarbons or chlorinated hydrocarbons, and 2
Examples include cerium ethylhexanoate and cerium naphthenate.

(b) Component (1), a reaction product of cerium chloride and an alkali metal silanolate having three or more organosiloxane units, is a reaction product of cerium chloride and the alkali metal silanolate having an alcohol such as ethanol, Impropatol, butasol, or A mixture of aromatic compounds such as benzene and toluene is used as a solvent, and the mixture is heated to room temperature or, if necessary, reflux temperature to react.Then, the solvent is distilled off (if necessary, the formed precipitate is filtered). do)
(See Japanese Patent Publication No. 53-980).

In this case, it is preferable that cerium chloride be reacted in an anhydrous state by appropriate dehydration treatment.

(b) The reaction product of component (2), cerium organic carboxylate soluble in aromatic hydrocarbons or chlorinated hydrocarbons, and an alkali metal silanolate having three or more organopolysiloxane units is usually an aromatic hydrocarbon or chlorinated hydrocarbon. It can be obtained by using a chlorinated hydrocarbon as a solvent and heating it to room temperature or, if necessary, reflux temperature to react, and then distilling off the solvent (if necessary, filtering the formed precipitate). (See Publication No. 51-66344).

(b) Component (3), the reaction product of cerium organic carboxylic acid soluble in aromatic hydrocarbons or chlorinated hydrocarbons, and hexamethyldisilazane is usually prepared using aromatic hydrocarbons or chlorinated hydrocarbons as a solvent. can be obtained by adding cerium organic carboxylate, hexamethyldisilazane and a small amount of water, and reacting the mixture at the reflux temperature of the solvent (see Japanese Patent Publication No. 32563/1983).

Component (c) organohydrodiene polysiloxane is an essential component for suppressing separation and precipitation of cerium when it comes into contact with rubber at high temperatures, and contains at least one silicon atom in one molecule. It has a bonded hydrogen atom. The organohydrogenpolysiloxane may be composed only of organohydrogensiloxane units or hydrogensiloxane units, or may contain other organosiloxane units. Other organic groups bonded to silicon atoms include alkyl groups such as methyl, ethyl, and propyl groups; substituted alkyl groups such as 2-phenylethyl, 2-phenylpropyl, and 3,3,3-triolopropyl; Examples include aryl groups or substituted aryl groups such as phenyl group, tolyl group, and the like. The structure of the organohydrodiene polysiloxane is not particularly limited, and may be linear, cyclic, or branched. Although the viscosity is not particularly limited, it is preferable that the viscosity at 25°C be 5 to 50°C for ease of blending with other ingredients
The range is 10,000CS.

Organohydrodiene polysiloxanes include dimethylhydrogensilyl end-blocked dimethylsiloxane/methylhydrodienesiloxane copolymer, trinotylsilyl endblocked dimethylsiloxane/methylhydrogensiloxane copolymer, dimethylphenylsilyl endblocked dimethyl Examples include siloxane/methylhydrogensiloxane copolymer, trimethylsilyl end-blocked methylhydrogensiloxane, and cyclic methylhydrodiene polysiloxane.

To obtain the composition of the present invention, component (B) should be added in an amount of 0.001 to 0, i parts by weight to 100 parts by weight of component (A).
Component (c) may be simply mixed at room temperature in such an amount that the content of hydrogen atoms bonded to silicon atoms in the present composition is flo-10,000 ppm.

In order to further improve the thermal stability of the composition of the present invention, metal salts of organic carboxylic acids such as norconium naphthenate and iron naphthenate, or metal alkoxy compounds such as isopropylalkoxy compounds of zirconium and n-butyl alkoxy compounds of titanium, etc. are added. May be combined.

The compositions of the present invention may also contain inorganic fillers, such as dry silica.
Wet silica, diatomaceous earth, powdered quartz, etc. may be blended, or metal soap, pigments, etc. may be blended. In addition, an organic peroxide vulcanizing agent such as benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl peroxide, etc. may be blended with the inorganic filler, or a silicate ester, triacetyl ester, etc. may be blended with the inorganic filler. A thermosetting or room temperature curable silicone rubber composition with excellent thermal stability can also be formed by blending a crosslinking agent such as silane or trioxime silane with a curing catalyst such as an aliphatic tin salt or a platinum compound.

〔Example〕

Next, the present invention will be explained in detail according to examples.

Preparation of Sample I〉 W, T, Grubb, R, C, 0stoff, Jo
internal of the American Chem
ical 5ociety 77°1405 (1955
2 to 60 g of potassium syralate synthesized from potassium hydroxide, hexamethylcyclot-lysiloxane, and octamethylcyclotetrasiloxane by the method described in
Dimethylpolysiloxane 12 with trimethylsilyl groups end-blocked at both ends and a viscosity of 20 cm at 5°C.
0g of hexamethylphosphoramide and 0.5g of hexamethylphosphoramide were added, and the mixture was reacted at 115°C for 2 hours under a nitrogen stream.

100 g of this reaction mixture was dissolved in 150 g of isopropanol, and a mixed alcohol solution (mixture of 50 g of ethanol and 50 g of methanol) of 2.5 g of anhydrous cerium chloride was added dropwise thereto with stirring. After filtering the reaction mixture, the solvent was distilled off at 40 to 50° C. under reduced pressure, and the filtrate was filtered again to remove a small amount of the generated precipitate to obtain a pale yellow liquid reaction product. The cerium concentration in the reaction product was 0.8% by weight.

33 g of potassium syralate and 0.3 g of hexamethylphosphoramide of <Sample I> were added to 67 g of dimethylpolysiloxane used in <Sample I>, and the mixture was heated at 115°C under a nitrogen stream.
Let it react for 1 hour, and then add decoys * Pot Shiren 1202 and 2-
Add 16 g of cerium ethylhexanoate and heat at reflux temperature for 2.
The reaction was allowed to proceed for 5 hours. After the reaction mixture was cooled to room temperature, 38% of trimethylchlorosilane was added to neutralize it. Xylene was distilled off under reduced pressure, and the resulting precipitate was filtered off to obtain a pale yellow liquid reaction product. The cerium concentration in this reaction product was 1.2% by weight.

To 150 g of xylene were added cerium octylate (cerium concentration 6%), 25 g of hexamethylsilazane, and 5 g of water, and after mixing at room temperature for 2 hours, the mixture was allowed to react for 2 hours under reflux of xylene, and the unreacted of water was distilled off as an azeotrope with xylene. Next, the same viscosity as <Sample 1> is 20
After adding 300 g of centistokes dimethylpolysiloxane, xylene was distilled off under reduced pressure to obtain a yellow liquid reaction product. The cerium concentration of this reaction product is 0.2
% by weight.

Example 1 A total of seven samples, Sample A to Sample G, were prepared as follows.

<Sample A> In a 100 mN beaker, 20 g of dimethylpolysiloxane with trimethylsilyl groups at both ends and having a viscosity of 100 centistokes at 25°C was weighed, and to this was added <Sample 1>0.2
0.01 g of methylhydrodiene polysiloxane having a viscosity of 20 centistokes and a viscosity at 25° C. (the amount of methyl groups is 50 mol % based on the total amount of substituents) was added and mixed at room temperature.

<Sample B> 20 g of dimethylpolysiloxane with a viscosity of 100 centistokes at 25°C was weighed into a 100 mN beaker, and 20 g of dimethylpolysiloxane with a viscosity of 100 centistokes at 25°C was weighed. 0.02 g of empolysiloxane (the amount of methyl groups is 80 mol % based on the total amount of substituents) was added and mixed at room temperature.

Sample C> In a beaker of 1001111, the viscosity at 25°C is 35.
Weigh out 20 g of dimethylpolysiloxane of 0 centistokes, and add to it <Sample 1> 1.0 g of methylhydrodiene polysiloxane with a viscosity of 20 centistokes at 25°C (the amount of methyl groups based on the total amount of substituents is 50 g).
0.02g of mol%) was added and mixed at room temperature.

<Sample D> 20 g of dimethylphenylpolysiloxane (the amount of phenyl group relative to the total amount of substituents is 5 mol %) with a viscosity of 100 centistokes at 25° C. was weighed into a 100 ml beaker, and 0.2 g and 25 g of sample I were weighed out. Methylhydrodiene polysiloxane with a viscosity of 20 cm or tokes at °C (the amount of methyl groups based on the total amount of substituents is 50 mol%)
) was added and mixed at room temperature.

Sample E> The viscosity of one 100 J beaker at 25°C is
oo centistokes dimethylpolysiloxane 20g
Weigh the sample 1>l), 2g and te)butyl titanium) 0,005g and viscosity 20 at 25°C.
Centistoke's methylhydrodiene polysiloxane (the amount of methyl groups based on the total amount of substituents is 50 mol%)
．． 01g was added and mixed at room temperature.

Sample F> 20 g of dimethylpolysiloxane having a viscosity of 500 centistokes at 25°C was weighed into a beaker made by 100 companies. (The amount of methyl groups is 50 mol % based on the total amount of substituents) was added in an amount of 0.01 g and mixed at room temperature.

<Sample G> In a beaker of 100+++N, the viscosity at 25°C is 10
Weigh out 20 g of dimethylpolysiloxane with a concentration of 0 centistokes, and add to it methylhytronene polysiloxane with a viscosity of 100 centistokes at 88 and 25°C (the amount of methyl groups based on the total amount of substituents is 50 g).
Add 0.01 g of mol%) and mix at room temperature.

A peroxide-vulcanized silicone rubber sheet (2 cm square, 2 mm thick) was immersed in a total of 7 samples, Sample A to Sample G, and left in a hot air circulation oven at 200°C. The changes in appearance were observed and the results are shown in Table 1.

Example 2 Five samples, Sample A>, Sample B>, Sample E, Sample F, and Sample G, prepared in Example 1, were prepared separately, and a platinum compound catalyst was used for each. An addition reaction-curable silicone rubber sheet (2c+++ square, 2 mm thick) was immersed and left in a hot air circulation oven at 200°C for 2 days. After taking out the silicone rubber sheet, each sample was placed in a hot air circulation oven at 300°C and the number of days until gelation was determined was determined. The results are shown in Table 2.

Comparative Example 1 A total of five samples, <Sample J> to <Sample N>, were prepared as follows.

<Sample J> The composition of Sample A of Example 1, which does not contain methylhytronene polysiloxane.

Sample K> The sample composition of Example 1, which does not contain methylhydrogen polysiloxane.

<Sample L> The composition of Sample E of Example 1, which does not contain methyl hydrogen polysiloxane.

<Sample M> The composition of Sample F of Example 1, which does not contain methylhydrodiene polysiloxane.

Sample N> The composition of Sample G of Example 1, which does not contain methylhydrodiene polysiloxane.

A peroxide vulcanized silicone rubber sheet (2cIIl square, 2III11cm thick) was immersed in a total of 5 samples from Sample J to Sample N, and left in a hot air circulation oven at 200°C. Changes in appearance were observed and the results are shown in Table 1.

Comparative Example 2 Sample J><Sample M><Sample N> prepared in Comparative Example 1
Three samples were prepared separately, and a platinum-catalyzed addition-curing silicone rubber sheet (2 cm square, 2 mm thick) was immersed in each sample, and the samples were left in an oven at 200°C for 2 days. After taking out the silicone rubber sheet, each sample was left in a hot air circulation oven at 300° C., and the number of days until gelation was determined was determined. The results are shown in Table 2.

Example 3 A peroxide vulcanized ethylene/propylene rubber sheet (2em square, 2mm thick) was added to <Sample A> prepared in Example 1.
1 mm) in a hot air circulation oven at 180°C.
As a result of leaving it for 22 days, there was no change in appearance at all.

Comparative Example 3 A peroxide-vulcanized ethylene/propylene rubber sheet (2 cm square, 2 cm thick) was added to <Sample J> prepared in Comparative Example 1.
III) was immersed and left in a hot air circulation oven at 180°C. As a result, it became cloudy within 2 days and cerium had separated and precipitated.

[Explanation of effects]

As explained above, the present invention solves the drawbacks of conventional cerium-containing organopolysiloxanes, and has developed an organopolysiloxane that has excellent heat resistance and does not separate or precipitate cerium even when it comes into contact with rubber at high temperatures. The obtained polysiloxane composition can be suitably used as a heating medium, a high-temperature transformer, an impregnating oil for rubber such as rubber rolls and rolling machines, a damper oil, and an oil for fan clutches. Furthermore, silicone grease and silicone compounds can also be produced by using the organopolysiloxane composition obtained according to the present invention as a base oil and adding a thickener such as a metal soap or a filler such as silica.

Claims (1)

[Claims] (a) Organopolysiloxane (b) represented by the average compositional formula Ra5iO□=''- (wherein R is a monovalent organic group and a is a number from 1 to 3) ■Cerium chloride Reaction product of cerium organic carboxylate soluble in aromatic hydrocarbons or chlorinated hydrocarbons and alkali metal silalate having 3 or more organopolysiloxane units - Reaction product with 1 or a mixture of 2 or more selected from the reaction products of cerium organic carboxylates soluble in aromatic hydrocarbons or chlorinated hydrocarbons and hexamethylsilazane (c) An organopolysiloxane composition consisting of an organohydrothene polysiloxane having at least one silicon-bonded hydrogen atom in one molecule.