Friction material composition and friction material therefrom
View Patent ↗The present invention is to provide a friction material composition comprising a fibrous material except for asbestos, an inorganic friction regulating agent, an organic friction regulating agent and a binder, wherein active alumina is contained as the inorganic friction regulating agent, and a fluorine series polymer is contained as the organic friction regulating agent, and to provide a friction material using the friction material composition.
1. A friction material composition which comprises a fibrous material except for asbestos, an inorganic friction regulating agent, an organic friction regulating agent and a binder, wherein active alumina is contained as the inorganic friction regulating agent in an amount of 1 to 15% by weight based on the whole composition, and a fluorine series polymer is contained as the organic friction regulating agent in an amount of 0.3 to 6% by weight based on the whole composition.
2. The friction material composition according to claim 1 , wherein the active alumina is active alumina having a specific surface area calculated by the BET method of 150 m 2 /g or more.
3. The friction material composition according to claim 1 , wherein the active alumina is γ-alumina.
4. The friction material composition according to claim 1 , wherein a content of the active alumina is 3 to 13% by weight based on the whole composition.
5. The friction material composition according to claim 1 , wherein a content of the active alumina is 5 to 11% by weight based on the whole composition.
6. The friction material composition according to claim 1 , wherein the fluorine series polymer is powder of a polytetrafluoroethylene.
7. The friction material composition according to claim 1 , wherein a content of the fluorine series polymer is 1 to 5% by weight based on the whole composition.
8. The friction material composition according to claim 1 , wherein a content of the fluorine series polymer is 2 to 4% by weight based on the whole composition.
9. The friction material composition according to claim 1 , wherein the active alumina is γ-alumina and the fluorine series polymer is a polytetrafluoroethylene.
10. A friction material which comprises a molded product of the friction material composition according to claim 1 under heating and pressure.
11. The friction material composition according to claim 3 , wherein the fluorine series polymer is powder of a polytetrafluoroethylene.
12. The friction material composition according to claim 1 , wherein the fluorine series polymer is a powder of said polymer.
13. The friction material composition according to claim 3 , wherein a content of the fluorine series polymer is 2 to 4% by weight based on the whole composition.
14. The friction material composition according to claim 1 , consisting essentially of said fibrous material, said active alumina, said fluorine series polymer and said binder.
15. The friction material composition according to claim 1 , wherein the active alumina is active alumina having a specific surface area calculated by the BET method of 180 m 2 /g or more.
16. The friction material composition according to claim 1 , wherein the active alumina is active alumina having a specific surface area calculated by the BET method of 200 to 300 m 2 /g or more.
17. The friction material composition according to claim 1 , wherein the active alumina has an average fine pore size within the range of 10 to 150 Å.
18. The friction material composition according to claim 1 , wherein the active alumina has an average fine pore size within the range of 50 to 100 Å.
19. The friction material composition according to claim 3 , wherein the γ-alumina is obtained by drying aluminum hydroxide at a low temperature so as to obtain alumina gel, and subjecting the alumina gel to calcination at a temperature of 500° to 800° C. so as to provide the γ-alumina.