| abstract |
Polyolefins are stabilized against oxidative deterioration by incorporating a compound of formula <FORM:1080185/C3/1> where X is C1- 12 alkylene, R and R1 are cyclohexyl or C3- 20 secondary alkyl, and R11 and R111\h are hydrogen, cyclohexyl or C3- 20 secondary alkyl. Specified polyolefins are polyethylene, polypropylene and polybutylene. The compositions may also comprise fillers, e.g. silicates, pigments, e.g. carbon black, zinc oxide and titanium oxide, and other stabilizers, e.g. nickelbis-dithiocarbonates, nickel-bis-dihydroxypolyalkylphenol sulphides, dilaury-b -mercaptodipropionate, dihydroxy tetra-alkyl sulphides, dihydroxytetralkyl methanes, phenyl naphthylamines, phenothiazine, alkylated phenols, diphenyl-p-phenylene diamine, salicylic acid esters, hydroxybenzophenones and nickel and cobalt salts of o-hydroxydiazobenzene. The aromatic nuclei of the compounds may contain inert substituents, and many suitable compounds are listed. They may be incorporated by mixing or added in solution in an alcohol or hydrocarbon. In examples polyethylene is stabilized by incorporating (I) 4,41-di sec. butylamino and dicyclohexylamino diphenylmethane, (II) 4,41 - dicyclohexylamino diphenylmethane, (III) 4,41-diisopropylamino and di sec. butylamino diphenylmethane, (IV) 4,41-dicyclohexylamino, diisopropylamino and di sec. butylamino diphenylpropane, and (V) 4,41-di(isopropylamino) - 3,31 - dimethoxy and 4,41-di(sec. butylamino) - 2,5,21,51 - tetramethoxy diphenylmethane; (VI) polypropylene is stabilized with 4,41-dicyclohexylamino diphenylpropane and 4,41-di sec. butylamino diphenylmethane; and (VII) polybutylene is stabilized with 4,41-dicyclohexylamino diphenylpropane. |