Rubber vulcanizates having improved ageing properties
AssigneeFlexSys, Inc.
InventorsRabindrah Nath Datta, Auke Gerardus Talma
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Abstract
The invention relates to a vulcanizable rubber composition comprising a rubber, sulfur or a sulfur donor, a vulcanization accelerator, a protective agent and 0.1 phr or more of an N,N′-disubstituted p-phenylenediamine protective agent is present in the form of a salt with an acid, and the composition does not comprise an elastomeric copolymer having glycidyl groups. The invention also relates to a vulcanization process comprising mixing and heating said rubber composition and to an article of manufacture comprising the rubber vulcanizate obtained by said process. Preferably, the acid is a C1-C24 monocarboxylic acid or a C2-C24 dicarboxylic acid, more preferably a C12-C20 fatty acid such as stearic acid. Most preferably, the protective agent is 6PPD.
Claims6
A vulcanizable rubber composition comprising a rubber, sulfur or a sulfur donor, a vulcanization accelerator, a protective agent and 0.1 phr or more of an N,N′-disubstituted p-phenylenediamine protective agent selected from the group consisting of N-isopropyl-N′-phenyl-p-phenylenediamine, N-(1,3-dimethyl-butyl)-N′-phenyl-p-phenylenediamine (6PPD), N,N′-bis-(1,4-dimethyl-pentyl)-p-phenylenediamine, N,N′-bis-(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,N′-diphenyl-p-phenylenediamine, N,N′-ditolyl-p-phenylenediamine, and N,N′-di-β-napthyl-p-phenylenediamine, present in the form of a salt with a C1-C24 monocarboxylic acid or a C2-C24 dicarboxylic acid, said composition not comprising an elastomeric copolymer having glycidyl groups.
Dependencies are inferred from the claim text.