Ethylene-propylene elastomers and ethylene-propylene-diene elastomers with improved heat and oil resistance

A high temperature and oil resistant elastomer composition comprising the peroxide-induced reaction product of, by weight,

• 100 parts of an elastomeric polymer selected from the group consisting of ethylene-propylene rubber and ethylene-propylene-diene rubber,
• about 10 to 35 parts of a crosslinking monomer selected from the group consisting of trimethylolpropane trimethacrylate, triallyl isocyanurate, polyethylene glycol dimethacrylate and ethylene glycol dimethacrylate,
• at least 6 parts of a chlorinated or brominated organic material that contains at least 30% of said halogen and is nonfugitive from said product at 350.degree. F.,
• about 0.025 to 0.055 equivalent per 100 parts of said polymer of a hindered phenolic antioxidant selected from the group consisting of tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate] methane;
• 1,6-hexamethylene-bis-(3,5-di-t-butyl-4-hydroxy hydrocinnamate);
• octodecyl 3,5-di-t-butyl-4-hydroxy hydrocinnamate;
• thiodiethylene-bis-(3,5-di-t-butyl-4-hydroxy hydrocinnamate);
• and 1,3,5-trimethyl-2,4,6-tris[3,5-t-butyl-4-hydroxybenzyl] benzene, and
• 10 to 25 parts of zinc oxide,
• said composition having a volume swell no greater than 130% when immersed in ASTM #3 oil at 150.degree. C. for 70 hours (ASTM D-471-68) and having an ultimate elongation of about 90% or more after aging 168 hours at 177.degree. C. (ASTM D-573-67).

A high temperature and oil resistant elastomer composition comprising the peroxide-induced reaction product of, by weight,

• 100 parts of an elastomeric polymer selected from the group consisting of ethylene-propylene rubber and ethylene-propylene-diene rubber,
• about 10 to 35 parts of a crosslinking monomer selected from the group consisting of trimethylolpropane trimethacrylate, triallyl isocyanurate, polyethylene glycol dimethacrylate and ethylene glycol dimethacrylate,
• at least 6 parts of a chlorinated or brominated organic material that contains at least 30% of said halogen and is nonfugitive from said product at 350.degree. F.,
• about 0.025 to 0.055 equivalent per 100 parts of said polymer of a ditertiary butyl group hindered phenolic antioxidant that does not prevent said peroxide-induced reaction,
• 10 to 25 parts of zinc oxide,
• 40 to 120 parts of a reinforcing filler and
• 0 to 100 parts of a nonreinforcing filler,
• said composition having a volume swell no greater than 130% when immersed in ASTM #3 oil at 150.degree. C. for 70 hours (ASTM D-471-68) and having an ultimate elongation of about 90% or more after aging 168 hours at 177.degree. C. (ASTM D-573-67).

A high temperature and oil resistant elastomer composition comprising the peroxide-induced reaction product of, by weight,

• 100 parts of an elastomeric polymer selected from the group consisting of ethylene-propylene rubber and ethylene-propylene-diene rubber,
• about 10 to 35 parts of a crosslinking monomer selected from the group consisting of trimethylolpropane trimethacrylate, triallyl isocyanurate, polyethylene glycol dimethacrylate and ethylene glycol dimethacrylate,
• at least 6 parts of a chlorinated or brominated organic material that contains at least 30% of said halogen and is nonfugitive from said product at 350.degree. F.,
• about 0.025 to 0.055 equivalent per 100 parts of said polymer of a hindered phenolic antioxidant selected from the group consisting of tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate] methane;
• 1,6-hexamethylene-bis-(3,5-di-t-butyl-4-hydroxy hydrocinnamate);
• octodecyl 3,5-di-t-butyl-4-hydroxy hydrocinnamate;
• thiodiethylene-bis-(3,5-di-t-butyl-4-hydroxy hydrocinnamate);
• and 1,3,5-trimethyl-2,4,6-tris [3,5-t-butyl-4-hydroxybenzyl] benzene,
• 10 to 25 parts of zinc oxide,
• 40 to 120 parts of a reinforcing filler and
• 0 to 100 parts of a nonreinforcing filler,
• said composition having a volume swell no greater than 130% when immersed in ASTM #3 oil at 150.degree. C. for 70 hours (ASTM D-471-68) and having an ultimate elongation of about 90% or more after aging 168 hours at 177.degree. C. (ASTM D-573-67).

A high temperature and oil resistant elastomer composition comprising the peroxide-induced reaction product of, by weight,

• 100 parts of an elastomeric polymer selected from the group consisting of ethylene-propylene rubber and ethylene-propylene-diene rubber,
• about 10 to 35 parts of a crosslinking monomer selected from the group consisting of trimethylolpropane trimethacrylate, triallyl isocyanurate, polyethylene glycol dimethacrylate and ethylene glycol dimethacrylate,
• at least 6 parts of a chlorinated or brominated organic material that contains at least 30% of said halogen and is nonfugitive from said product at 350.degree. F.,
• about 0.025 to 0.055 equivalent per 100 parts of said polymer of a hindered phenolic antioxidant selected from the group consisting of tetrakis[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate] methane;
• 1,6-hexamethylene-bis-(3,5-di-t-butyl-4-hydroxy hydrocinnamate);
• octodecyl 3,5-di-t-butyl-4-hydroxy hydrocinnamate;
• thiodiethylene-bis-(3,5-di-t-butyl-4-hydroxy hydrocinnamate);
• and 1,3,5-trimethyl-2,4,6-tris[3,5-t-butyl-4-hydroxybenzyl] benzene,
• 10 to 15 parts of zinc oxide,
• 5 to 8 parts of magnesium oxide,
• 40 to 120 parts of a reinforcing filler and
• 0 to 100 parts of a nonreinforcing filler,
• said composition having a volume swell no greater than 130% when immersed in ASTM #3 oil at 150.degree. C. for 70 hours (ASTM D-471-68) and having an ultimate elongation of about 90% or more after aging 168 hours at 177.degree. C. (ASTM D-573-67).