Method for producing silicone rubber compound and silicone rubber composition

摘要

A method for producing a silicone rubber compound in a reduced blending time, and which imparts excellent resistance to plasticity reversion and the cured silicone rubber prepared without heat treatment has excellent resistance to compression set. (A) an organopolysiloxane with polymerization degree of at least 100 represented by the following average compositional formula (I):
R1aSiO(4-a)/2  (I)
(R1: a substituted or unsubstituted monovalent hydrocarbon group, a: 1.95 to 2.05), (B) a reinforcing silica having a specific surface area (BET) of at least 50 m2/g, and (C) a preliminary hydrolysis product of (C-1) an alkoxysilane represented by the following formula (II):
R2mSi(OR3)4-m  (II)
(R2: hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R3: a substituted or unsubstituted alkyl group, m: 0, 1, 2, or 3), and (C-2) water at a molar amount 0.3 to 5 times the alkoxy group in the alkoxysilane of component (C-1) are mixed and heated.

主权项

1. A method for producing a silicone rubber compound comprising the steps of mixing the components (A) to (C):
(A) 100 parts by weight of an organopolysiloxane having a degree of polymerization of at least 100 represented by the following average compositional formula (I):
R1aSiO(4-a)/2  (I)wherein R1 is independently a substituted or unsubstituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05,
(B) 5 to 100 parts by weight of a reinforcing silica having a specific surface area as measured by BET absorption method of at least 50 m2/g, and (C) a preliminary hydrolysis product of
(C-1) 0.1 to 20 parts by weight of an alkoxysilane represented by the following formula (II):
R2mSi(OR3)4-m  (II)wherein R2 is independently hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, R3 is independently a substituted or unsubstituted alkyl group, and m is 0, 1, 2, or 3, and
(C-2) water at a molar amount 0.3 to 5 times the amount of the alkoxy group in the alkoxysilane of the component (C-1), and subjecting the mixture to a heat treatment.