Fluoro-rubber composition and cross-linked rubber article using same

• US 9,815,972 B2
• Filed: 03/10/2015
• Issued: 11/14/2017
• Est. Priority Date: 11/29/2012
• Status: Active Grant

• Current Assignee: AGC, Inc.
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Yamada, Takeshi, Iruya, Ken
• Primary Examiner(s): ZIMMER, MARC S
• Application Number:
  US14/642,885
• Publication Number:
  US 20150175779A1
• Time in Patent Office: 980 Days
• Field of Search: 524424, 524492, 524493, 428403, 428405
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 5/14 Peroxides
• CPC Class Codes: C08K 5/34 Heterocyclic compounds having nitrogen in the ring
• CPC Class Codes: C08K 5/3477 Six-membered rings
• CPC Class Codes: C08K 5/34924 containing cyanurate groups; Tautomers thereof
• CPC Class Codes: C08K 9/06 with silicon-containing compounds
• CPC Class Codes: C08L 27/12 containing fluorine atoms
• CPC Class Codes: C08L 83/08 containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
• CPC Class Codes: C09K 3/1009 Fluorinated polymers, e.g. PTFE

Abstract

To provide a fluoro-rubber composition whereby good hardness and good elongation are obtainable in a rubber article after cross-linking, and a cross-linked rubber article using the same.

A fluoro-rubber composition comprising a fluoro-rubber, a hydrophobic silica and a cross-linking agent, wherein the hydrophobic silica is one having hydrophobized with hexamethyldisilazane or silicone oil, and the content of the hydrophobic silica is from 1 to 50 parts by mass and the content of the cross-linking agent is from 0.1 to 5 parts by mass, per 100 parts by mass of the fluoro-rubber; and a cross-linked rubber article obtained by cross-linking such a fluoro-rubber composition.

Claims

1. A fluoro-rubber composition comprising:

a fluoro-rubber;

a hydrophobic silica in an amount of from 1 to 50 parts by mass per 100 parts by mass of the fluoro-rubber;

a cross-linking agent which is an organic peroxide, in an amount of from 0.1 to 5 parts by mass per 100 parts by mass of the fluoro-rubber;

a cross-linking assistant selected from the group consisting of triallyl cyanurate, triallyl isocyanurate, triacryl formal, triallyl trimellitate, dipropargyl terephthalate, diallyl phthalate, tetraallyl terephthalamide, triallyl phosphate, trimethallyl isocyanurate, 1,3,5-triacryloylhexahydro-1,3,5-triazin, m-phenylenediamine bismaleimide, p-quinone dioxime, p,p′

-dibenzoylquinone dioxine, dipropargyl terephthalate, and N,N′

,N″

,N′

″

-tetraallyl terephthalamide in an amount of from 0.1 to 30 parts by mass per 100 parts by mass of the fluoro-rubber; and

carbon black in an amount of from 1 to 50 parts by mass per 100 parts by mass c fluoro-rubber,

wherein the hydrophobic silica is one which is hydrophobized with hexamethyldisilazane and the hydrophobic silica has a specific surface of from 25 to 200 m²/g.

2. The fluoro-rubber composition according to claim 1, wherein the hydrophobic silica has an average primary particle size of from 5 to 50 nm.

3. The fluoro-rubber composition according to claim 1, wherein the fluoro-rubber is at least one member selected from the group consisting of a vinylidene fluoride/hexafluoropropylene copolymer, a tetrafluoroethylene/propylene copolymer, a vinylidene fluoride/tetrafluoroethylene/hexafluoropropylene copolymer and a tetrafluoroethylene/propylene/vinylidene fluoride copolymer.

4. The fluoro-rubber composition according to claim 3, wherein the fluoro-rubber is a tetrafluoroethylene/propylene copolymer.

5. The fluoro-rubber composition according to claim 1, wherein the cross-linking assistant is at least one member selected from the group consisting of triallyl cyanurate, triallyl isocyanurate and trimethallyl isocyanurate.

6. A cross-linked rubber article obtained by cross-linking the fluoro-rubber composition as defined in claim 1.

7. The cross-linked rubber article according to claim 6, wherein the cross-linked rubber article is a rubber member for oil drilling.

8. The fluoro-rubber composition according to claim 1, wherein the amount of the cross-linking agent is from 0.5 to 3 parts by mass per 100 parts by mass of the fluoro-rubber.

9. The fluoro-rubber composition according to claim 1, wherein the amount of the hydrophobic silica is from 10 to 45 parts by mass per 100 parts by mass of the fluoro-rubber.

10. The fluoro-rubber composition according to claim 1, wherein the amount of the hydrophobic silica is from 20 to 40 parts by mass per 100 parts by mass of the fluoro-rubber.

11. The fluoro-rubber composition according to claim 1, wherein the hydrophobic silica is a dry silica.

12. The fluoro-rubber composition according to claim 5, wherein the amount of the cross-linking agent is from 0.5 to 3 parts by mass per 100 parts by mass of the fluoro-rubber.

13. The fluoro-rubber composition according to claim 11, wherein the hydrophobic silica has an average primary particle size of from 5 to 50 nm.

14. The fluoro-rubber composition according to claim 12, wherein the hydrophobic silica is a dry silica.

15. The fluoro-rubber composition according to claim 13, wherein the amount of the hydrophobic silica is from 20 to 40 parts by mass per 100 parts by mass of the fluoro-rubber.

16. The fluoro-rubber composition according to claim 14, wherein the hydrophobic silica has an average primary particle size of from 5 to 50 nm.

17. The fluoro-rubber composition according to claim 14, wherein the amount of the hydrophobic silica is from 20 to 40 parts by mass per 100 parts by mass of the fluoro-rubber.

18. The fluoro-rubber composition according to claim 16, wherein the amount of the hydrophobic silica is from 20 to 40 parts by mass per 100 parts by mass of the fluoro-rubber.

19. The fluoro-rubber composition according to claim 1, wherein the specific surface area of the hydrophobic silica is from 130 to 185 m²/g.