| 摘要 |
The oxidation of synthetic rubber is reduced with substantially no increase in susceptibility to light discoloration by adding a 2,21-methylene-bis-(4,6-dialkyl phenol) of the formula <FORM:0677584/IV (a)/1> in which R1 is an alkyl radical of 1-3 carbon atoms and R2 is a tertiary alkyl radical of 4-8 carbon atoms, the linkage from the tertiary carbon atom being directly to the phenol ring. Preferably from 0.25 to 2.5 parts of the antioxidant is used to 100 parts of the rubber, and may be added solid or in a solution in benzene or in toluene. The preferred compound is 2,21-methylene-bis-(4-methyl, 6-tertiary butyl phenol). The synthetic rubbers may be polymers of butadiene-1,3, methyl-2-butadiene-1,3, chloro-2-butadiene-1,3, piperylene, or 2,3-dimethyl-butadiene-1,3, or copolymers of butadiene-1,3, with styrene, vinyl naphthalene, acrylic acid, methyl acrylate, methyl methacrylate, acrylonitrile, methacrylonitrile, methacrylamide, isobutylene, methyl vinyl ether, methyl vinyl ketone or vinylidene chloride. Specification 677,585 is referred to.
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