Heat-resistant millable silicone rubber composition

Patent metadata

Field	Value
Publication number	US-10954385-B2
Application number	US-201716338303-A
Country	US
Kind code	B2
Filing date	Oct 18, 2017
Priority date	Oct 28, 2016
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

Provided is a millable silicone rubber composition capable of yielding a silicone rubber (cured product) superior in heat resistance. The composition contains:
(A) 100 parts by mass of an organopolysiloxane having at least two silicon atom-bonded alkenyl groups in one molecule, and having an average polymerization degree of not lower than 100; (B) 5 to 100 parts by mass of a reinforcing silica having a specific surface area of not smaller than 50 m 2 /g; (C) 0.01 to 10 parts by mass of a titanium oxide doped with a transition metal oxide of 0.01 to 5% by mass; (D) 0.01 to 10 parts by mass of a cerium oxide and/or a cerium hydroxide; and (E) 0.01 to 10 parts by mass of a curing agent.

First claim

The invention claimed is:

1. A heat-resistant millable silicone rubber composition comprising:
(A) 100 parts by mass of an organopolysiloxane having at least two silicon atom-bonded alkenyl groups in one molecule, and having an average polymerization degree of not lower than 100;
(B) 5 to 100 parts by mass of a reinforcing silica having a specific surface area of not smaller than 50 m 2 /g;
(C) 0.01 to 10 parts by mass of a titanium oxide doped with a transition metal oxide of 0.01 to 5% by mass;
(D) 0.01 to 10 parts by mass of a cerium oxide and/or a cerium hydroxide; and
(E) 0.01 to 10 parts by mass of a curing agent.

2. The heat-resistant millable silicone rubber composition according to claim 1 , wherein a content of the transition metal oxide in the silicone rubber composition is 0.001 to 0.1% by mass.

3. The heat-resistant millable silicone rubber composition according to claim 1 or 2 , wherein the transition metal oxide is an iron oxide.

4. The heat-resistant millable silicone rubber composition according to claim 1 , further comprising a dispersant for filler, as a component (F).

5. The heat-resistant millable silicone rubber composition according to claim 1 , wherein the component (E) is an organic peroxide.

6. The heat-resistant millable silicone rubber composition according to claim 1 , wherein the component (E) is composed of an organohydrogenpolysiloxane and a platinum group metal catalyst.

7. A cured product of the heat-resistant millable silicone rubber composition according to claim 1 .

Assignees

• Shinetsu Chemical Co

Inventors

• Todoroki Daichi
• Koike Yoshiaki

Classifications

• C08L83/04 Primary

  Polysiloxanes · CPC title

• C08G77/20

  containing silicon bound to unsaturated aliphatic groups · CPC title

• C08G77/16

  to hydroxy groups · CPC title

• C01P2006/12

  Surface area · CPC title

• C08K2201/006

  Additives being defined by their surface area · CPC title