Rubber composition

• US 4,560,729 A
• Filed: 10/19/1984
• Issued: 12/24/1985
• Est. Priority Date: 10/19/1983
• Status: Expired due to Term

• Current Assignee: Nippon Zeon Co., Ltd.
• Original Assignee: Nippon Zeon Co., Ltd.
• Inventors: Watanabe, Noboru, Kubo, Yoichiro
• Primary Examiner(s): Schofer, Joseph L.
• Assistant Examiner(s): Lipman, Bernard
• Application Number:
  US06/662,684
• Time in Patent Office: 431 Days
• Field of Search: 525/305, 525/313, 525/315, 525/377, 525/233
• US Class Current: 525/233
• CPC Class Codes: C08K 5/0025 Crosslinking or vulcanising agents; including accelerators
• CPC Class Codes: C08K 5/14 Peroxides
• CPC Class Codes: C08L 15/00 Compositions of rubber derivatives C08L11/00, C08L13/00 take precedence
• CPC Class Codes: C08L 9/02 Copolymers with acrylonitrile

Abstract

A rubber composition having improved steam resistance comprising a nitrile group-containing hydrocarbon rubber having an iodine number of not more than 120, an organic peroxide vulcanizer and a crosslinking coagent, the amount of said crosslinking coagent being 8 to 30 parts by weight per 100 parts by weight of said rubber.

Claims

1. A rubber composition having improved steam resistance comprising a nitrile group-containing hydrocarbon rubber having an iodine number of not more than 120 and containing 10 to 60% by weight of units derived from an unsaturated nitrile, an organic peroxide vulcanizer and a crosslinking coagent selected from multiple unsaturated groups-containing monomers, polyfunctional oxime compounds and 1,2-polybutadiene, the amount of said crosslinking coagent being 8 to 30 parts by weight per 100 parts by weight of said rubber.

2. The rubber composition of claim 1 wherein the nitrile group-containing hydrocarbon rubber is selected from hydrogenated unsaturated nitrile/conjugated diene copolymer rubbers, unsaturated nitrile/ethylenically unsaturated monomers/conjugated diene copolymer rubbers, hydrogenated products thereof, and unsaturated nitrile/ethylenically unsaturated monomer copolymer rubbers.

3. The rubber composition of claim 1 wherein the nitrile group-containing hydrocarbon rubber contains from 20 to 45% by weight of units derived from an unsaturated nitrile.

4. The rubber composition of claim 1 wherein the iodine number of the hydrocarbon rubber is not more than 80.

5. The rubber composition of claim 1 wherein the iodine number of the hydrocarbon rubber is not more than 40.

6. The rubber composition of claim 1 wherein the unsaturated nitrile is acrylonitrile or methacrylonitrile.

7. The rubber composition of claim 1 wherein the nitrile group-containing hydrocarbon rubber is a rubber selected from the group consisting of the hydrogenation product of butadiene/acrylonitrile copolymer rubber;

the hydrogenation product of isoprene/butadiene/acrylonitrile copolymer rubber;

the hydrogenation product of isoprene/acrylonitrile copolymer rubber;

butadiene/methylacrylate/acrylonitrile copolymer rubber;

butadiene/acrylic acid/acrylonitrile copolymer rubber;

the hydrogenation product of butadiene/methacrylate/acrylonitrile copolymer rubber;

the hydrogenation product of butadiene/acrylic acid/acrylonitrile copolymer rubber;

butadiene/ethylene/acrylonitrile copolymer rubber;

butylacrylate/ethoxyethylacrylate/vinyl chloroacetate/acrylonitrile copolymer rubber; and

butylacrylate/ethoxyethylacrylate/vinyl norbornene/acrylonitrile copolymer rubber.

8. The rubber composition of claim 1 wherein the crosslinking coagent is a polyfunctional monomer selected from the group consisting of diallyl phthalate, triallyl phthalate, triallyl cyanurate, triallyl isocyanurate, ethylene dimethacrylate, diethylene glycol dimethylacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, tolylene bismaleimide, meta-phenylene bismaleimide, divinylbenzene and trivinylbenzene.

9. The rubbber composition of claim 1 wherein the crosslinking coagent is p,p'"'"'-dibenzoylquinone dioxime.

10. The rubber composition of claim 1 wherein the crosslinking coagent is 1,2-polybutadiene.

11. The rubber composition of claim 1 wherein the amount of the crosslinking coagent is from 10 to 25 parts by weight, per 100 parts by weight of the rubber.