JPH0563513B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to translucent, high strength organopolysiloxane compositions for liquid injection molding. More specifically, the present invention provides a method for specific olefin-containing organopolysiloxane mixtures.
The present invention relates to a composition as described above which can be cured by a SiH addition reaction. Organopolysiloxane compositions for liquid injection molding are known and used in practice. A problem with all such compositions is that hardness, tensile strength, elongation and tear strength are interdependent and also dependent on the viscosity of the uncured liquid;
It is difficult to improve desired properties without degrading other properties. In particular, it is desirable to improve hardness and tear strength without degrading other properties. Jeram, US Pat. Nos. 3,884,866 and 3,957,713, describes high strength addition curable compositions suitable for low pressure liquid injection molding. These compositions include a first part consisting of a high viscosity vinyl-terminated organopolysiloxane, a low viscosity organopolysiloxane containing vinyl groups, a filler, and a platinum catalyst; Curing is accomplished by mixing a second liquid containing a hydrogen silicone composition. Such compositions have a low durometer hardness (Shore A hardness of 20 to 35), and it is difficult to improve the durometer hardness without adversely affecting other properties. Lee et al., U.S. Pat. No. 4,162,243, discloses a composition similar to that of Dieram, which uses fumed silica treated with hexamethyldisilazane and tetramethyldivinyldisilazane. The biggest feature is that it contains. Lee et al.'s composition has a low viscosity in the uncured state and has high strength and strength after curing.
Provides an elastomer with high hardness while maintaining good properties including elongation and tear strength. Sweet, US Pat. No. 4,427,801, is an extension of the invention of Lee et al., which features the incorporation of MM ^Vi Q resin in addition to fumed silica treated with a vinyl-containing silazane.
The result is an elastomer with further improved hardness and tear strength, but has the disadvantage of exhibiting increased compression set and decreased Bashore resilience. One of the objects of the present invention is to provide liquid injection moldable organopolysiloxane compositions that exhibit improved hardness and tear strength without adversely affecting other physical properties. Another object of the present invention is to provide an organopolysiloxane composition for liquid injection molding as described above that also exhibits good storage stability and good mold release properties. These and other objects will become apparent to those skilled in the art upon consideration of the following detailed description. DETAILED DESCRIPTION OF THE INVENTION In accordance with the present invention, a liquid injection molding organopolysiloxane is provided which exhibits low viscosity, high strength and good elongation, as well as excellent hardness and tear strength. Such a composition comprises (A)(1)25 (mol)
% phenyl groups, at 25°C from about 2000 to about
70 to 98 parts by weight linear high viscosity organopolysiloxane having a viscosity of 1,000,000 centipoise and end-terminated with vinyl groups; (2) containing at least one terminal vinyl group per molecule; (mol)
% vinyl group content, a viscosity of about 50 to about 5000 centipoise at 25° C., and 1 to 15 parts by weight of a linear low viscosity organopolysiloxane having a viscosity of from about 50 to about 5000 centipoise at 25° C. and containing not more than 25 (mol) % phenyl groups. , and (3) about 0.1 to about
Contains 25 (mol)% vinyl groups, about 50~ at 25℃
Has a viscosity of approximately 100,000 centipoise and approximately 25
100 parts by weight of a vinyl group-containing organopolysiloxane component consisting of 1 to 15 parts by weight of an on-chain vinyl group-containing organopolysiloxane containing up to (mol)% phenyl groups; (B) about 5 to about 70 parts by weight; parts by weight of a filler or filler mixture, (C) about 0.1 to 50 ppm platinum catalyst, based on the total amount of the organopolysiloxane composition, and (D) a hydrogen-containing silane and a hydrogen-containing organopolysiloxane. from about 0.1 to about 25 parts by weight of the components of the SiH composition, and optionally further (E) from about 5 to about 100 parts by weight at 25°C.
It is characterized by additionally containing about 0.1 to about 6.0 parts by weight of a hydroxyl group-containing organopolysiloxane oil having a viscosity of centipoise. Such compositions can be cured to form an elastomer at room temperature for 16 hours or at elevated temperatures, for example 200° C., for 10 seconds. According to a preferred embodiment, the above composition is of a two-part type. In that case, the first liquid contains at least the entire amount of component (C),
Further, the first liquid contains at least the entire amount of component (D). The linear high viscosity organopolysiloxane which is component (A)(1) of the present invention contains not more than 25 (mol)% phenyl groups and has a concentration of about 2,000 to about 1,000,000 centipoise at 25°C, preferably about 10,000 to about 500,000 centipoise. It has a centipoise viscosity and is terminated with a vinyl group. Such high viscosity organopolysiloxanes have the general formula (wherein Vi represents a vinyl group, R is a monovalent hydrocarbon group having up to about 20 carbon atoms and
and x has a value of from about 100 to about 10,000, preferably from 500 to 2,000. Suitable high viscosity organopolysiloxanes are disclosed in US Pat. No. 3,884,866. The linear low viscosity organopolysiloxane which is component (A)(2) of the present invention contains at least one terminal vinyl group per molecule, preferably from about 0.01 to about 60 (mol)%, preferably from 0.05 to 10 (mol)%. mol)%, and has a viscosity of about 50 to about 5000 centipoise at 25°C, preferably about 50 to about 1000 centipoise, and about
It contains 25 (mol)% or less of phenyl group. Such low viscosity organopolysiloxanes have the general formula (wherein R is as defined above and R ¹
is a group similar to R, but at least one R ¹ must be a vinyl group, and y is from about 1 to about
750).
Suitable low viscosity organopolysiloxanes are disclosed in US Pat. No. 3,884,866. Component (A)(3) of the present invention, an organopolysiloxane containing vinyl groups on the chain, is essential to obtain the desired properties. Suitable on-chain vinyl group-containing organopolysiloxanes contain from about 0.1 to about 25 (mol)%, preferably from about 0.2 to about 5 (mol)% vinyl groups;
About 50 to about 100,000 centipoise at 25°C, preferably about
Has a viscosity of 100 to about 10,000 centipoise, and about
It contains 25 (mol)% or less of phenyl group. Such organopolysiloxanes are (1)
Formula R _a R ² _b SiO _(4-ab)/2 [3] (wherein R is as defined above, R ²
is an olefinic hydrocarbon group bonded to the silicon atom by a C-Si bond and generally contains 1 to 20 aliphatic carbon atoms in a straight or branched chain, and preferably contains multiple aliphatic carbon atoms. siloxane units containing 1 to 12 carbon atoms connected by bonds, a having a value of 0 to 2, and the sum of a and b equaling 0.8 to 3.0; (2) from a siloxane unit of the formula R _c SiO _(4-c)/2 [4] in which R is as defined above and c has a value from 0.8 to 2.5; It can be defined as a copolymer consisting of: R ² in the above formula is, for example, an allyl group,
It may be a methallyl group, a butenyl group, a pentenyl group, an ethenyl group, etc., but preferably a vinyl group. Such a copolymer generally contains 0.5 to 99.5 (mol)% of units represented by formula [3] and 0.5 to 99.5 (mol)% of units represented by formula [4]. Methods for preparing such copolymers are known in the art. They are disclosed in U.S. Pat. No. 3,344,111 to Chalk and U.S. Pat. No. 3,436, to Modic. Suitable on-chain vinyl organopolysiloxanes have the general formula (wherein R and R ² are as defined above and d and e are up to about 20 (mol)%
R ² is a positive integer such that it imparts a content of R 2 to the copolymer. Preferably, ^R2 is a vinyl group, and the ^R2 content is about 0.05 to
10 (mol)%, and the viscosity is about 300 to about 25℃.
It is within 1000 centipoise. As mentioned above, R is a group selected from the group consisting of monovalent hydrocarbon groups having up to about 20 carbon atoms and monovalent halogenated hydrocarbon groups, in other words, This is a group that usually exists as a substituent. That is, R
includes mononuclear and dinuclear aryl groups (e.g. phenyl, tolyl, xylyl, naphthyl, etc.), halogenated mononuclear and dinuclear aryl groups (e.g. chlorophenyl, chloronaphthyl, etc.), mononuclear aryl lower alkyl groups having 1 to 8 carbon atoms (for example, benzyl group), lower alkyl groups having 1 to 8 carbon atoms (for example, methyl group, ethyl group, propyl group,
(butyl group, pentyl group, hexyl group, octyl group, etc.), lower alkenyl group having 2 to 8 carbon atoms (for example, vinyl group, allyl group, 1-propenyl group, etc.), halogenated carbon atom number 1 to 8
lower alkyl groups (eg, chloropropyl group, trifluoropropyl group, etc.), and cycloalkyl groups (eg, cyclobutyl group, cyclopentyl group, cyclohexyl group, etc.). Although R can be any group selected from the above group, it is important to note that all R must not be high molecular weight groups, and that R must not be chosen such that it will adversely affect the reaction of the vinyl group. It will be obvious to those skilled in the art that this is not the case. Note that R is preferably a lower alkyl group having 1 to 8 carbon atoms (eg, methyl group, ethyl group, etc.) or a trifluoropropyl group.
In particular, it is more preferred if at least about 70 (mol)% of R is a methyl group. The key point of the present invention, and in particular what distinguishes the compositions of the present invention from conventional SiH-olefined silicone rubber compositions, is the presence of three types of vinyl group-containing organopolysiloxanes in the compositions of the present invention. . As mentioned above, these vinyl group-containing organopolysiloxanes include a high viscosity organopolysiloxane as component (A)(1), a low viscosity organopolysiloxane as component (A)(2), and a component (A)( 3) is an organopolysiloxane containing vinyl groups on the chain. Approximately 70 to 98 parts by weight of component (A) per 100 parts by weight of the vinyl group-containing organopolysiloxane
(1), about 1 to 15 parts by weight of component (A)(2) and about 1 to 15 parts by weight of component (A)(3) should be present. In addition, if about 80 to 95 parts by weight of component (A)(1), about 3 to 10 parts by weight of component (A)(2), and about 3 to 10 parts by weight of component (A)(3) are present. More preferred. The use of such organopolysiloxane mixtures containing vinyl groups gives cured compositions which have particularly good hardness and tear strength as well as high strength and good elongation. That is, such cured compositions have a tensile strength of greater than about 1000 psi, an elongation of greater than 600%, a tear strength of greater than 200 Ibs/in, and a Shore A hardness of 35-40 or greater. The SiH composition, component (D) of the present invention, serves as a crosslinking agent and can be selected from the group consisting of hydrogen-containing silanes and hydrogen-containing organopolysiloxanes. Note that it is preferable to use a hydrogen-containing organopolysiloxane. The hydrogen-containing organopolysiloxanes of the present invention have the formula R _f H _g SiO _(4-fg)/2 [6] where R is a monovalent saturated hydrocarbon group having up to about 20 carbon atoms and is a group selected from the group consisting of valent halogenated saturated hydrocarbon groups, f has a value of 0 to 2, and the sum of f and g is 0.8 to
be defined as a copolymer consisting of at least one siloxane unit per molecule represented by the formula [4] (equal to 3.0) and a siloxane unit represented by the formula [4] (wherein R is a saturated group) I can do it. The viscosity of such hydrogen-containing organopolysiloxanes may range from about 5 to about 1000 centipoise, preferably from about 5 to about 100 centipoise at 25°C. The hydrogen-containing organopolysiloxanes mentioned above include, for example, MQ resins having H(R) ₂ SiO _1/2 units and SiO ₂ units. It also includes hydrogen-substituted resins such as MDQ, MTQ, and MDT. Such a copolymer generally contains 0.5 to 99.5 (mol)% of units represented by formula [6] and 0.5 to 99.5 (mol)% of units represented by formula [4]. Suitable hydrogen-containing organopolysiloxanes have the formula (wherein R is as defined above except for excluding unsaturated groups, and R ³ is as defined above except for excluding unsaturated groups and adding a hydrogen atom.
, h has a value of 1 to 1000, and i has a value of 5 to 200). In addition, h is 10
It is even more preferred if it has a value of 500 and i has a value of 5 to 200. The hydrogen-containing organopolysiloxane as component (D) is used in an amount of about 0.1 to 25 parts by weight, preferably about 0.5 to 10 parts by weight per 100 parts by weight of component (A). In addition,
At least one hydrogen atom per vinyl group in component (A) is present in the SiH composition, and preferably from about 1.5 to about 2.5 hydrogen atoms per vinyl group. is desirable. Many types of platinum catalysts are known for such SiH-olefin addition reactions, and such platinum catalysts can also be used for the reaction of the present invention. Suitable platinum catalysts, particularly where optical clarity is required, are those that are soluble in the reaction mixture of the present invention. Such platinum catalysts are described in Ashby's U.S. patent no.
It can be carried from platinum compounds of the formulas (PtCl ₂ olefin) ₂ and H (PtCl ₃ olefin) as described in the specification of No. 3159601. The olefin included in these two formulas can be almost any type of olefin, but is preferably C2-C8 alkylene, C5-7 cycloalkylene, or styrene. Examples of olefins that can be used in the above formula include ethylene, propylene, butylene, octylene, cyclopentene, cyclohexene, cycloheptene, and the like, and various isomers thereof. Another example of a platinum-containing material that can be used in the compositions of the invention is Ashby.
Examples include platinum chloride/cyclopropane complexes of the formula (PtCl ₂ .C ₃ H ₆ ) ₂ as described in US Pat. No. 3,159,662. Still other examples of platinum-containing materials include complexes of chloroplatinic acid and organic compounds, such as those described in Lamoreaux, US Pat. No. 3,220,972. The organic compounds mentioned above are selected from the group consisting of alcohols, ethers, aldehydes and mixtures thereof, and are used in amounts up to 2 moles per gram of platinum. Furthermore, the contents of the patents and patent applications mentioned in this specification are all incorporated into this specification by reference. Suitable platinum compounds which can be used not only as platinum catalysts but also as flame retardants are platinum complexes such as those described in Karstedt, FR 1548775. Generally speaking, such platinum complexes are produced by reacting chloroplatinic acid containing 4 moles of water of hydration with tetravinylcyclotetrasiloxane in the presence of an ethanolic solution of sodium bicarbonate. Ru. Determining an effective amount of such platinum catalyst will be easy for one skilled in the art. Generally, from about 0.1 to
50 ppm platinum catalyst is used. In order to obtain high tensile strength in the compositions of the invention, it is desirable to incorporate fillers as component (B) into the compositions, especially when such compositions are to be formed into thin coatings or films. Examples of various fillers that can be used include titanium dioxide, lithopone, zinc oxide, zirconium silicate,
Silica airgel, iron oxide, diatomaceous earth, calcium carbonate, fumed silica, silazane-treated silica, precipitated silica, glass fiber, magnesium oxide, chromic oxide, zirconium oxide, aluminum oxide, alpha quartz, calcined clay, asbestos, carbon, graphite , cork, cotton, synthetic fibers, etc. Suitable fillers to be used in the compositions of the invention are surface-treated fumed or precipitated silicas. Following one surface treatment method,
Fumed silica or precipitated silica is exposed to a cyclic organopolysiloxane under heat and pressure. Such a surface treatment method is disclosed in Lucas US Pat. No. 2,938,009. Another surface treatment method is to expose the silica to siloxane or silane in the presence of an amine compound. This method is disclosed in US Pat. No. 3,024,126. A preferred method of surface treating the filler is using a methylsilane or silazane surface treating agent. Fumed and precipitated silicas that have been surface treated with methylsilane or silazane flow easily and therefore do not undesirably increase the low viscosity of the uncured composition. At the same time, silazane-treated silica fillers improve the physical properties (particularly tear strength) of the cured elastomer. In addition,
The best properties are obtained if the filler is subjected to an in-situ silazane treatment, ie if the filler is combined with component (A). Silazane-treated fumed and precipitated silicas are described in Smith, US Pat. No. 3,635,743 and Beers, US Pat. No. 3,847,848. Fillers as component (B) are generally used in amounts of 5 to 70 parts by weight, preferably 15 to 50 parts by weight per 100 parts by weight of component (A). Suitable fillers are silazane-treated fumed silica or a mixture of silazane-treated fumed silica and silazane-treated precipitated silica. Note that the latter mixture is particularly preferred. Such mixtures may contain fumed silica and precipitated silica in a weight ratio of about 25/1 to about 1/1, preferably about 10/1 to about 5/1. The hydroxyl group-containing organopolysiloxane oil as component (E) can be added to extend the shelf life of the liquid injection molding organopolysiloxane composition. When silazane-treated precipitated silica is present in such compositions, extended shelf life and mold release properties can be obtained by adding a hydroxyl-containing organopolysiloxane oil along with the precipitated silica. Suitable hydroxyl-containing organopolysiloxane oils are those having a viscosity at 25°C of from about 5 to about 100 centipoise, preferably from about 20 to about 50 centipoise. Such a hydroxyl group-containing organopolysiloxane oil has the formula R _j (OH) _k SiO _(4-ik)/2 [8] (wherein R is as defined above and j is 0 to 3 preferably has a value of 0.5 to 2.0, k is 0.005
~ has a value of about 2, and the sum of j and k is 0.8 ~
(equal to 3). The hydroxyl group-containing organopolysiloxane is preferably a linear type having a hydroxyl group at the end. In order to obtain mold releasability by combining silazane-treated precipitated silica and component (E), or to obtain extension of shelf life by adding component (E) alone,
There is present in (B) at least about 2 parts by weight of silazane-treated precipitated silica per 100 parts by weight of component (A), and component (E) is present in an amount of from about 1 to about 5 parts by weight per 100 parts by weight of component (A). It must be present in proportion. Until curing, component (C) and component (D) are packaged separately as a first part and a second part, respectively. Components (A), (B), (E) and additives may be added separately to both the first liquid and the second liquid, or may be added to only one of them. In this way, premature reactions during storage and transport are prevented. If it is desired to produce a cured silicone rubber composition, the first and second parts can be mixed and the mixture cured for 16 hours at room temperature. Note that the higher the temperature, the shorter the curing time. The mixture of the first liquid and the second liquid can be injection molded as it is, or can be used for forming a film or coating after being dissolved in a solvent. During injection molding, the mixing barrel and injection chamber must be kept at low temperatures to prevent premature curing. Mold temperature is generally around 150
It should be within the range of ~500〓. As solvents for film or coating formation, organic solvents customary for conventional SiH addition reactants can be used. Examples of such solvents include hexane, heptane, pentane, octane, cyclohexane, toluene, xylene, acetone, and the like.
Of course, other components can be added depending on various purposes. That is, pigments, thixotropic agents, heat stabilizers, etc. may be added according to those skilled in the art. In particular, it is desirable to add an inhibitor such as a maleate ester to obtain sufficient working time for the material after addition of the catalyst. A suitable inhibitor is disclosed in U.S. Pat. No. 4,256,870.
It is stated in the specification of the issue. EXAMPLE MATERIALS (A) High Viscosity Organopolysiloxane Terminated with Vinyl Groups A dimethylpolysiloxane terminated with dimethylvinylsilyl groups having a viscosity of 80,000 centipoise at HVO1-25°C. HVO2 - Dimethylpolysiloxane terminated with dimethylvinylsilyl groups, having a viscosity of 4000 centipoise at 25°C. (B) Low Viscosity Organopolysiloxane Containing Vinyl Groups A dimethylpolysiloxane end-terminated with one trimethylsilyl group and one dimethylvinylsilyl group, having a viscosity of 500 centipoise at LVO-25°C. (C) an organopolysiloxane containing on-chain vinyl groups, VCO1 having a viscosity of 500 centipoise at -25°C and a vinyl group content of about 1.65% (by weight);
Dimethyl/methylvinyl polysiloxane terminated with dimethylvinylsilyl groups. VCO2 has a viscosity of 2,000,000 centipoise at −25°C and a MeVi siloxy group content of about 13.5 (mol)%. Dimethyl/methylvinyl polysiloxane terminated with trimethylsilyl groups. (D) Silica filler Surface treated with cyclic methyl tetramer of fused silica. Precipitated silica - surface treated with hexamethyldisilazane. (E) Catalyst A platinum catalyst from Karlshutts was used by dissolving it in methylvinyl tetramer. Lamoreau's platinum catalyst - 10 (by weight) in LVO1 support
It was used after being dispersed at a concentration of %. (F) SiH crosslinker RHC - 20 centipoise viscosity at −25°C and approx.
Formula M ^H ₂ Q, with a hydrogen content of 0.9% (by weight)
An aliphatic hydrogen-containing crosslinking agent represented by: Viscosity of 55 centipoise at LHC −25°C and approx.
Formula M ^H D _h with a hydrogen content of 0.8% (by weight)
Linear hydrogen-containing crosslinker represented by D ^H _i M ^H. (G) Hydroxyl group-containing oil A silanol group-terminated dimethylpolysiloxane oil having a viscosity of 30 centistokes at HF-25°C and having the formula HO-D _6-9 -OH. Examples are shown below to explain the present invention in more detail. Note that these Examples should not be construed as limiting the scope of the present invention. Examples 1-7 Various liquid injection molding compositions were prepared according to the following procedures. First, the vinyl group-containing organopolysiloxane and fumed silica were mixed. As mentioned above, the fumed silica was treated only with cyclic methyl tetramer. 6.0
The fumed silica was surface treated in situ by adding parts by weight of hexamethyldisilazane and 2.0 parts by weight of water. The mixture was heated to 135°C under reduced pressure. During such treatment water and ammonia by-products were removed. Thereafter, the remaining ingredients were added and the resulting composition was injection molded. The results thus obtained are shown in Table 1.

[Table] According to these examples, increasing the content of on-chain vinyl organopolysiloxane while keeping the SiH/SiVi ratio constant increases the durometer hardness without any substantial decrease in tensile strength and elongation. It can be seen that an increase in tear strength and tear strength can be obtained. In addition,
These compositions had poor storage stability and mold release properties. Furthermore, since LVO was not included, the tear strength did not reach a sufficient level. Example 8 Examples 1 to 7 using the compositions shown in Table 2
The procedure was repeated. The storage stability and mold release properties of the composition thus obtained were excellent. Example 9 Examples 1 to 7 using the compositions shown in Table 3
The procedure was repeated. The storage stability and mold release properties of the composition thus obtained were poor.

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Claims (1)

[Scope of Claims] 1 (A) (1) The organo group is selected from a lower alkyl group having 1 to 8 carbon atoms, a phenyl group, and a trifluoropropyl group, and
Contains 25 (mol)% or less phenyl group, 25℃
has a viscosity of 2000 to 1000000 centipoise,
and 70 to 98 parts by weight of a linear high viscosity organopolysiloxane terminated with a vinyl group; and contains at least one terminal vinyl group per molecule, from 0.01 to
It has a vinyl group content of 60 (mol)% and 50 at 25°C.
1 to 15 parts by weight of a linear low viscosity organopolysiloxane having a viscosity of ~1000 centipoise and containing up to 25 (mol)% phenyl groups, and (3) 0.1 to 25 (mol)% vinyl groups. Contains 25
1 having a viscosity of 50 to 100,000 centipoise at °C and containing not more than 25 (mol)% of phenyl groups
100 parts by weight of a vinyl-containing organopolysiloxane component consisting of ~15 parts by weight of an organopolysiloxane containing on-chain vinyl groups; (B) (1) a methylsilane- or silazane-treated fumed silica; and (2) at least 1 part by weight of 5 to 70 parts by weight of a filler or filler mixture consisting of methylsilane or silazane treated precipitated silica, the weight ratio of said fumed silica to said precipitated silica being in the range from 5/1 to 10/1; (C) 0.1 to 50 ppm of a platinum catalyst based on the total amount of the organopolysiloxane composition; (D) 0.1 to 25 parts by weight of a SiH composition selected from the group consisting of hydrogen-containing silanes and hydrogen-containing organopolysiloxanes; (E) 1 to 5 parts by weight of a hydroxyl group-containing organopolysiloxane oil having a viscosity of 5 to 100 centipoise at 25°C. 2 The linear high viscosity organopolysiloxane has the general formula (In the formula, Vi represents a vinyl group, and R is 1 to 8
The organo group is selected from lower alkyl groups of 1,000 carbon atoms, phenyl groups, and trifluoropropyl groups, and x has a value of 100 to 10,000. Compositions as described in Section. 3 The linear low viscosity organopolysiloxane has the general formula (wherein R is the organo group selected from lower alkyl groups of 1 to 8 carbon atoms, phenyl groups, and trifluoropropyl groups,
R ¹ is the same group as R, but at least one R ¹
must be a vinyl group, and y is from 1 to
750). 4. The composition according to claim 3, wherein only one R ¹ is a vinyl group. 5 The organopolysiloxane containing on-chain vinyl groups has the formula R _a R ² _b SiO _(4-ab)/2 , where R is a monovalent hydrocarbon group having up to 20 carbon atoms and a monovalent a group selected from the group consisting of halogenated hydrocarbon groups, R ² is an olefinic hydrocarbon group, and a has a value of 0 to 2;
and the sum of a and b is equal to 0.8 to 3.0) and 0.5 to 99.5 (mol)% units of the formula R _c SiO _(4-c)/2 (wherein R is defined above) 99.5, and c has a value from 0.8 to 2.5)
0.5 (mol) % of the composition according to claim 1. 6 The SiH composition has the formula R _f H _g SiO _(4-fg)/2 (wherein R is a monovalent saturated hydrocarbon group having up to 20 carbon atoms and a monovalent halogenated saturated hydrocarbon group). is a group selected from the group consisting of groups, and f is 0
has a value of ~2, and the sum of f and g is 0.8 to 3.0
0.5 to 99.5 (mol)% of units of the formula R _c SiO _(4-c)/2 , where R is as defined above and c is from 0.8 to 2.5. 99.5
The composition according to claim 1, which is an organopolysiloxane comprising 0.5 (mol) % units. 7 In an organopolysiloxane composition consisting of separately packaged first and second parts, (A) (1) the organo group is a lower alkyl group of 1 to 8 carbon atoms, a phenyl group, and a trifluoro group; selected from among propyl groups and 25
(mole)% or less phenyl groups at 25℃
70 to 98 parts by weight of a linear high viscosity organopolysiloxane having a viscosity of 2,000 to 1,000,000 centipoise and end-terminated with a vinyl group; (2) a lower alkyl group in which the organo group has 1 to 8 carbon atoms;
selected from phenyl group and trifluoropropyl group, contains at least one terminal vinyl group per molecule, and has a polyvinyl group of 0.01 to 60
(mol)% vinyl group content, 50~50 at 25℃
Has a viscosity of 1000 centipoise and 25 (moles)
1 to 15 parts by weight of a linear low viscosity organopolysiloxane containing up to % phenyl groups, and (3)
Contains 0.1-25 (mol)% vinyl groups, at 25℃
Has a viscosity of 50-100000 centipoise, and 25
1 to 15 containing phenyl groups up to (mol)%
100 parts by weight of a vinyl group-containing organopolysiloxane component consisting of 100 parts by weight of organopolysiloxane containing vinyl groups on the chain is present in either or both of the first liquid and the second liquid. (B) comprising (1) methylsilane or silazane treated fumed silica and (2) at least 1 part by weight of methylsilane or silazane treated precipitated silica, the weight ratio of said fumed silica to said precipitated silica being from 5/1 to 10. 5 to 70 parts by weight of a filler or filler mixture, such as up to (C) a total amount of platinum catalyst from 0.1 to 50 ppm based on the total amount of the organopolysiloxane composition is present in the first liquid; and (D) a platinum catalyst selected from the group consisting of hydrogen-containing silanes and hydrogen-containing organopolysiloxanes. A total amount of 0.1 to 25 parts by weight of the SiH composition is present in the first liquid, and (E) 1 to 5 parts by weight of a hydroxyl group-containing organopolysiloxane oil having a viscosity of 5 to 100 centipoise at 25°C. An organopolysiloxane composition characterized in that all or part of the body is present in either or both of the first liquid and the second liquid. 8 The linear high viscosity organopolysiloxane has the general formula (In the formula, Vi represents a vinyl group, and R is 1 to 8
Claim 7, wherein said organo group is selected from lower alkyl groups, phenyl groups, and trifluoropropyl groups of 5 carbon atoms, and x has a value from 100 to 10,000. Compositions as described in Section. 9 The linear low viscosity organopolysiloxane has the general formula (wherein R is the organo group selected from lower alkyl groups of 1 to 8 carbon atoms, phenyl groups, and trifluoropropyl groups,
R ¹ is the same group as R, but at least one R ¹
must be a vinyl group, and y is from 1 to
750). 10. The composition according to claim 9, wherein only one R ¹ is a vinyl group. 11 The organopolysiloxane containing on-chain vinyl groups has the formula R _a R ² _b SiO _(4-ab)/2 , where R is a monovalent hydrocarbon group having up to 20 carbon atoms and a monovalent a group selected from the group consisting of halogenated hydrocarbon groups, R ² is an olefinic hydrocarbon group, and a has a value of 0 to 2;
and the sum of a and b is equal to 0.8 to 3.0) and 0.5 to 99.5 (mol)% units of the formula R _c SiO _(4-c)/2 (wherein R is defined above) 99.5, and c has a value from 0.8 to 2.5)
8. The composition according to claim 7, comprising .about.0.5 (mol)% units. 12 The SiH composition has the formula R _f H _g SiO _(4-fg)/2 (where R is a monovalent saturated hydrocarbon group having up to 20 carbon atoms and a monovalent halogenated saturated hydrocarbon group). is a group selected from the group consisting of groups, and f is 0
has a value of ~2, and the sum of f and g is 0.8 to 3.0
0.5 to 99.5 (mol)% of units of the formula R _c SiO _(4-c)/2 , where R is as defined above and c is from 0.8 to 2.5. 99.5
8. The composition of claim 7, which is an organopolysiloxane comprising .about.0.5 (mol)% units.