Heat resistant silicone rubber composition
View Patent ↗A heat resistant silicone rubber composition containing greater than or equal to 0.1 mass % each of titanium oxide and iron oxide is disclosed. The heat resistant silicone rubber composition can form a heat resistant silicone rubber suitable for use in a high temperature environment. A method of reducing formaldehyde and/or low molecular weight organopolysiloxane generated from a cured product of a heat resistant silicone rubber composition upon heating the cured product is also disclosed. The method comprises compounding greater than or equal to 0.1 mass % each of titanium oxide and iron oxide in the heat resistant silicone rubber composition. Generally, even when the cured product is heated to a high temperature, such as a temperature greater than or equal to 300° C., generation of formaldehyde and/or low molecular weight organopolysiloxane (e.g. D4, D5, and D6) from the cured product can be reduced.
1. A method of reducing the amount of a gas comprising low molecular weight organopolysiloxane, and optionally formaldehyde, generated from a cured product of a heat resistant silicone rubber composition upon heating the cured product, the method comprising:
compounding 0.1 to 1 mass % each of titanium oxide and red iron oxide (α-Fe 2 O 3 ) in the heat resistant silicone rubber composition;
wherein the cured product of the heat resistant silicone rubber composition comprises the low molecular weight organopolysiloxane; and
wherein the low molecular weight organopolysiloxane comprises D4 (octamethylcyclotetrasiloxane), D5 (decamethylcyclopentasiloxane), D6 (dodecamethylcyclohexasiloxane), or combinations thereof.
2. The method according to claim 1 , wherein the mass ratio of compounded amounts of the titanium oxide to the red iron oxide is from 1:10 to 10:1.
3. The method according to claim 2 , wherein the mass ratio of compounded amounts of the titanium oxide to the red iron oxide is 1:1.
4. The method according to claim 2 , wherein 0.2 to 1 mass % each of titanium oxide and red iron oxide are compounded in the heat resistant silicone rubber composition.
5. The method according to claim 4 , wherein 0.5 to 1 mass % each of titanium oxide and red iron oxide are compounded in the heat resistant silicone rubber composition.
6. The method according to claim 5 , wherein the mass ratio of compounded amounts of the titanium oxide to the red iron oxide is 1:1.
7. The method according to claim 1 , wherein 0.2 to 1 mass % each of titanium oxide and red iron oxide are compounded in the heat resistant silicone rubber composition.
8. The method according to claim 7 , wherein 0.5 to 1 mass % each of titanium oxide and red iron oxide are compounded in the heat resistant silicone rubber composition.
9. The method according to claim 1 , wherein the red iron oxide has a particle diameter of 1 μm or less.
10. The method according to claim 1 , wherein the BET specific surface area of the titanium oxide is greater than or equal to 10 m 2 /g.
11. The method according to claim 10 , wherein the BET specific surface area of the titanium oxide is less than or equal to 500 m 2 /g.
12. The method according to claim 1 , wherein the heat resistant silicone rubber composition cures via peroxide cure.
13. The method according to claim 12 , wherein the heat resistant silicone rubber composition comprises organopolysiloxane raw rubber and organic peroxide.
14. The method according to claim 1 , wherein the gas generated from heating the cured product of the heat resistant silicone rubber composition comprises the low molecular weight organopolysiloxane and formaldehyde.
15. The method according to claim 1 , wherein the heat resistant silicone rubber composition cures via hydrosilylation cure.
16. A heat resistant silicone rubber formed by curing the heat resistant silicone composition formed according to claim 1 .
17. The heat resistant silicone rubber according to claim 16 , wherein the heat resistant silicone rubber is a heat cooking vessel or a packing/sealing.