FLUOROSILICONE RUBBER COMPOSITION AND CURED PRODUCT THEREOF

• US 20100098892A1
• Filed: 10/16/2009
• Published: 04/22/2010
• Est. Priority Date: 10/17/2008
• Status: Abandoned Application

• Current Assignee: Shin-Etsu Chemical Company Limited
• Original Assignee: Shin-Etsu Chemical Company Limited
• Inventors: HAYASHIDA, Osamu, KOIKE, Yoshiaki, OISHI, Kazuhiro
• Application Number:
  US12/580,699
• Publication Number:
  US 20100098892A1
• Time in Patent Office: Days
• US Class Current: 428/36.8
• CPC Class Codes: C08K 5/0025 Crosslinking or vulcanising agents; including accelerators
• CPC Class Codes: C08L 83/08 containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
• CPC Class Codes: Y10T 428/1386 Natural or synthetic rubber or rubber-like compound containing

Abstract

A fluorosilicone rubber composition including: (A) an organopolysiloxane containing trifluoropropyl groups and monovalent aliphatic unsaturated hydrocarbon groups, with a viscosity at 25° C. of not less than 10,000 mPa·s, represented by a specific average composition formula, in an amount of 100 parts by mass, (B) a silica-based filler, in an amount of 2 to 100 parts by mass, (C) a hydrotalcite-based inorganic anion exchanger, in an amount of 0.1 to 20 parts by mass, and (D) a curing agent, in an effective amount. Also disclosed is a cured product obtained by curing the composition. The composition forms a molded item that exhibits minimal deterioration in physical properties even when exposed to heat at temperatures of 200° C. or higher.

Claims

1. A fluoro silicone rubber composition comprising:

(A) an organopolysiloxane with a viscosity at 25°

C. of not less than 10,000 mPa·

s, represented by an average composition formula (1) shown below;

R¹_aR²_bR³_cSiO_(4-a-b-c)/2 

 

(1)

wherein

R¹ represents a trifluoropropyl group,

each R² independently represents an unsubstituted or substituted monovalent aliphatic unsaturated hydrocarbon group of 2 to 8 carbon atoms,

each R³ independently represents a hydroxyl group, an unsubstituted monovalent aliphatic saturated hydrocarbon group of 1 to 8 carbon atoms, or an unsubstituted or substituted monovalent aromatic hydrocarbon group of 6 to 8 carbon atoms,

a is a positive number within a range from 0.96 to 1.01, b is a positive number within a range from 0.0001 to 0.01, and c is a positive number within a range from 0.96 to 1.06, provided that a+b+c satisfies 1.98≦

a+b+c≦

2.02,

in an amount of 100 parts by mass,

(B) a silica-based filler, in an amount of 2 to 100 parts by mass,

(C) a hydrotalcite-based inorganic anion exchanger, in an amount of 0.1 to 20 parts by mass, and

(D) a curing agent, in an effective amount.

2. The composition according to claim 1, wherein component (A) comprises a hydroxyl group as R³, and a proportion of R³ groups that are hydroxyl groups is within a range from 0.001 to 10 mol % of all R³ groups.

3. The composition according to claim 1, wherein a polymerization degree of component (A) is not less than 500.

4. The composition according to claim 1, wherein a specific surface area of component (B) is not less than 50 m²/g.

5. The composition according to claim 1, wherein component (B) is a fumed silica, a calcined silica, a precipitated silica, or a combination thereof.

6. The composition according to claim 1, wherein an amount added of component (C) is within a range from 0.5 to 10 parts by mass per 100 parts by mass of said organopolysiloxane of component (A).

7. The composition according to claim 1, wherein component (D) is at least one of (D1) an organic peroxide and (D2) a combination of a platinum group metal-based catalyst and an organohydrogenpolysiloxane.

8. A cured product, obtained by curing the composition defined in claim 1.

9. A fluorosilicone rubber molded item, formed from a cured product defined in claim 8.

10. The molded item according to claim 9, which is a rubber molded item selected from the group consisting of a turbo air hose, an O-ring, a diaphragm, a packing and a gasket.