US 5,516,832 A · Curable silicone rubber composition

Abstract

The present invention relates to a peroxide-curable silicone rubber composition which, when cured, exhibits a reduced modulus and improved tear strength relative to prior art systems without sacrificing other desirable properties, such as high tensile strength of the cured rubber or storage stability of the uncured rubber base, said composition comprising: (A) 100 parts by weight of a diorganopolysiloxane gum; (B) 10 to 75 parts by weight a reinforcing filler; (C) a polybutylene oligomer having a number average molecular weight of 200 to less than 900 and having functionality selected from the group consisting of epoxy, alkoxyphenylene, hydroxyl, carboxyl, anhydride and fully saturated; and, optionally, (D) a hydroxy-terminated diorganopolysiloxane having a degree of polymerization of 2 to 50.

Claims19

Dependent claims

A composition comprising:

(A) 100 parts by weight of a diorganopolysiloxane gum;
(B) 10 to 75 parts by weight of a reinforcing filler;
(C) a polybutylene having a number average molecular weight of 200 to less than 900, said polybutylene being selected from the group consisting of
(i) polybutylene having functionality selected from the group consisting of epoxy, alkoxyphenylene, hydroxyl, carboxyl, and anhydride and
(ii) fully saturated polybutylene;
and
(D) a hydroxy-terminated diorganopolysiloxane having a degree of polymerization of 2 to 50, wherein the ratio of said hydroxy-terminated diorganopolysiloxane (D) to said polybutylene (C) is 1:5 to 5:1 and a total of 0.02 to 0.5 part by weight of said components (C) plus (D) is present for each part of said filler (B).

4 more elements

Dependencies are inferred from the claim text.

Curable silicone rubber composition

Life of this patent

Curable silicone rubber composition

Life of this patent

Abstract

Claims19