| 摘要 |
Addition polymers are protected against oxidation by the incorporation of 0.001 to 5% by weight of an acid catalysed condensation product of a ketone or aldehyde with a phenolic fraction having an initial boiling point of 180 DEG to 230 DEG C. and a final boiling point of 250 DEG to 400 DEG C. obtained from coal, wood or petroleum distillates. Specified addition polymers are polyethylene, polypropylene and natural or synthetic rubbers, e.g. polymers of isobutylene, butadiene, 2-methyl- or chlorobutadiene and their copolymers with each other or with styrene, acrylonitrile or methyl methacrylate. When the polymer is polypropylene a dialkylthiodialkanoate is desirably present as additional antioxidant. The composition may also contain conventional adjuvants, e.g. pigments, fillers, plasticizers, blowing agents, antiozonants, vulcanization agents, accelerators or retarders, and waxes. The phenolic fraction will be a mixture of mono-, di- and tri-primary and secondary alkylphenols, indanols, alkyl indanols, naphthols and alkylnaphthols. Specified ketones are acetone, methyl ethyl, isobutyl and isoamyl ketones, ethyl butyl ketone, cyclohexanone, diacetone alcohol and 4-methoxy-4-methyl-pentan-2-one. Specified aldehydes are formaldehyde and its polymers, acetaldehyde, butyraldehyde, nonaldehyde, aromatic aldehydes and aldehyde generators, e.g. acetals and alpha-chloroalkyl ethers.
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