Room temperature-curable electrically conductive fluorosilicone rubber composition

1. A room temperature-curable electrically conductive fluorosilicone rubber composition comprising:

(A) a fluoropolysiloxane capped at the molecular terminals with hydroxyl groups having a viscosity at 25° C. of from 1,000 to 1,000,000 mPa·s;

(B) a fine silica powder having a BET specific surface area of not less than 50 m 2 /g;

(C) a carbon black;

(D) a fibrous carbon allotrope having a graphene structure; and

(E) a crosslinking agent;

wherein component (D) is comprised in an amount of not less than 1.5 parts by mass per 100 parts by mass of component (A); and

wherein component (D) is a carbon nanofiber or a carbon nanotube.

2. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , wherein component (A) is a fluoropolysiloxane represented by:

HO(R 1 R 2 SiO) n H

wherein R 1 is a monovalent hydrocarbon group having from 1 to 20 carbon atoms, from 50 to 100 mol % of R 2 are fluorine-substituted alkyl groups having from 1 to 12 carbon atoms, the remainder of R 2 are monovalent hydrocarbon groups having from 1 to 20 carbon atoms, and “n” is a value such that the viscosity at 25° C. is from 1,000 to 1,000,000 mPa·s.

3. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 2 , wherein “n” is a value from 100 to 500.

4. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 2 , wherein component (B) is comprised in an amount of from 6 to 50 parts by mass per 100 parts by mass of component (A).

5. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 4 , wherein component (C) is comprised in an amount of from 1 to 20 parts by mass per 100 parts by mass of component (A).

6. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 5 , wherein:

i) component (D) is a carbon nanotube;

ii) component (D) is comprised in an amount of not more than 5.0 parts by mass per 100 parts by mass of component (A); or

iii) both i) and ii).

7. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 6 , wherein:

i) component (E) is a triketoximosilane or a triacetoxysilane;

ii) component (E) is comprised in an amount of from 1 to 30 parts by mass per 100 parts by mass of component (A); or

iii) both i) and ii).

8. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 7 , further comprising: (F) a fluoropolysiloxane capped at the molecular terminals with hydroxyl groups having a viscosity at 25° C. of from 1 to 900 mPa·s.

9. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 8 , wherein component (F) is comprised in an amount of from 0.1 to 50 parts by mass per 100 parts by mass of component (A).

10. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , wherein component (B) is comprised in an amount of from 6 to 50 parts by mass per 100 parts by mass of component (A).

11. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , wherein component (C) is comprised in an amount of from 1 to 20 parts by mass per 100 parts by mass of component (A).

12. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , wherein component (D) is a carbon nanotube.

13. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 12 , wherein component (D) is comprised in an amount of not more than 5.0 parts by mass per 100 parts by mass of component (A).

14. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , wherein component (D) is comprised in an amount of not more than 5.0 parts by mass per 100 parts by mass of component (A).

15. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , wherein component (E) is a triketoximosilane or a triacetoxysilane.

16. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 15 , wherein component (E) is comprised in an amount of from 1 to 30 parts by mass per 100 parts by mass of component (A).

17. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , wherein component (E) is comprised in an amount of from 1 to 30 parts by mass per 100 parts by mass of component (A).

18. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , further comprising: (F) a fluoropolysiloxane capped at the molecular terminals with hydroxyl groups having a viscosity at 25° C. of from 1 to 900 mPa·s.

19. The room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 18 , wherein component (F) is comprised in an amount of from 0.1 to 50 parts by mass per 100 parts by mass of component (A).

20. A cured product of the room temperature-curable electrically conductive fluorosilicone rubber composition according to claim 1 , said cured product having:

i) a tensile strength of not less than 2.0 MPa in accordance with JIS K 6251;

ii) an elongation at break of not less than 200% in accordance with JIS K 6251;

iii) a volume resistivity of from 1×10 2 to 1×10 12 Ω·cm when 5 V are applied; or

iv) combinations thereof.