HYDROGENATED NITRILE RUBBER COMPOSITION

• US 20140191477A1
• Filed: 08/03/2012
• Published: 07/10/2014
• Est. Priority Date: 09/13/2011
• Status: Abandoned Application

• Current Assignee: Eagle Industry Company Limited
• Original Assignee: Eagle Industry Company Limited
• Inventors: Kobayashi, Osamu, Murakami, Hideyuki
• Application Number:
  US14/239,035
• Publication Number:
  US 20140191477A1
• Time in Patent Office: Days
• US Class Current: 277/650
• CPC Class Codes: C08K 2201/019 the composition being defined by the absence of a certain additive
• CPC Class Codes: C08K 3/013 Fillers, pigments or reinforcing additives
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 3/22 of metals
• CPC Class Codes: C08K 3/26 Carbonates; Bicarbonates
• CPC Class Codes: C08K 3/34 Silicon-containing compounds
• CPC Class Codes: C08K 3/346 Clay
• CPC Class Codes: C08K 3/36 Silica
• CPC Class Codes: C08K 5/103 with polyalcohols
• CPC Class Codes: C08K 5/14 Peroxides
• CPC Class Codes: C08L 15/005 Hydrogenated nitrile rubber
• CPC Class Codes: C09K 2200/0612 Butadiene-acrylonitrile rubber
• CPC Class Codes: C09K 3/10 Materials in mouldable or extrudable form for sealing or packing joints or covers filling pastes C09D5/34
• CPC Class Codes: F04B 53/16 Casings; Cylinders; Cylinder liners or heads; Fluid connections
• CPC Class Codes: F04B 53/164 Stoffing boxes
• CPC Class Codes: F04D 29/026 especially adapted for liquid pumps
• CPC Class Codes: F04D 29/126 especially adapted for liquid pumps
• CPC Class Codes: F05C 2225/02 Rubber
• CPC Class Codes: F05D 2300/431 Rubber
• CPC Class Codes: F16J 15/02 between relatively-stationary surfaces F16J15/46, F16J15/48 take precedence

Abstract

Disclosed is a hydrogenated nitrile rubber composition comprising 100 parts by weight of hydrogenated nitrile rubber having a bound acrylonitrile content of 31 to 50% and an iodine value of 30 mg/100 mg or less, 30 to 300 parts by weight of carbon black having a particle size of 61 nm or more and/or other filler, 0.5 to 30 parts by weight of a polyfunctional unsaturated compound cocrosslinking agent, and 1 to 10 parts by weight of an organic peroxide. The hydrogenated nitrile rubber composition has excellent roll processability and can be suitably used as a vulcanization-molding material for a cup gasket or bellows having excellent LLC resistance used in a water pump mechanical seal.

Claims

1. A hydrogenated nitrile rubber composition used as a vulcanization-molding material for a cup gasket or bellows of a water pump mechanical seal, the composition comprising:

100 parts by weight of hydrogenated nitrile rubber having a bound acrylonitrile content of 31 to 50% and an iodine value of 30 mg/100 mg or less;

30 to 300 parts by weight of carbon black having a particle size, as measured according to ASTM D1765, of 61 nm or more and/or other filler;

0.5 to 30 parts by weight of a polyfunctional unsaturated compound co-crosslinking agent; and

1 to 10 parts by weight of an organic peroxide.

2. The hydrogenated nitrile rubber composition according to claim 1, which is free of a plasticizer.

3. The hydrogenated nitrile rubber composition according to claim 1, which provides a static sealing material having a durometer A hardness of less than 70.

4. The hydrogenated nitrile rubber composition according to claim 1, wherein the other filler is at least one member selected from silica, graphite, clay, talc, coke, calcium carbonate, alumina, silicon carbide, and titanium oxide.

5. The hydrogenated nitrile rubber composition according to claim 4, wherein silica is used in combination with 8 parts by weight or less of a coupling agent.

6. The hydrogenated nitrile rubber composition according to claim 1, wherein the polyfunctional unsaturated compound cocrosslinking agent is a difunctional or trifunctional (meth)acrylate.

7. The hydrogenated nitrile rubber composition according to claim 1, wherein the polyfunctional unsaturated compound cocrosslinking agent is used in an amount of 1 to 10 parts by weight.

8. A cup gasket or bellows of a water pump mechanical seal, wherein the cup gasket or bellows is vulcanization-molded from the hydrogenated nitrile rubber composition according to claim 1.

9. The hydrogenated nitrile rubber composition according to claim 2, which provides a static sealing material having a durometer A hardness of less than 70.

10. The hydrogenated nitrile rubber composition according to claim 2, wherein the other filler is at least one member selected from silica, graphite, clay, talc, coke, calcium carbonate, alumina, silicon carbide, and titanium oxide.

11. The hydrogenated nitrile rubber composition according to claim 10, wherein silica is used in combination with 8 parts by weight or less of a coupling agent.

12. The hydrogenated nitrile rubber composition according to claim 6, wherein the polyfunctional unsaturated compound cocrosslinking agent is used in an amount of 1 to 10 parts by weight.

13. A cup gasket or bellows of a water pump mechanical seal, wherein the cup gasket or bellows is vulcanization-molded from the hydrogenated nitrile rubber composition according to claim 2.