GB688501A - Improvements in or relating to rubber antioxidants - Google Patents

Abstract

Synthetic rubber, e.g. a copolymer of butadiene with styrene or acrylonitrile, is preserved by treating it with a compound of the general formula <FORM:0688501/IV (a)/1> where R and R1 are like or unlike alkyl, cycloalkyl, or aralkyl groups containing at least 3 carbon atoms. Preferably R and R1 are alkyl groups containing not more than four carbon atoms. Specified compounds are those in which R and R1 of the above formula are dimethyl, diethyl, di-n-propyl, di-isopropyl, di-n-butyl, di-tert.-butyl, di-isobutyl, di-isoamyl, di-tert.-amyl, di-n-hexyl, di-n-heptyl, di-n-octyl, di-tert.-octyl, dilauryl, dicyclohexyl, dicyclopentyl, di-gammaphenyl-propyl, di-benzyl, di-beta-phenethyl, and di-(alpha-methyl benzyl) groups.ALSO:Natural or synthetic rubber is preserved by treating it with a compound of the general formula:- <FORM:0688501/V/1> where R and R1 are like or unlike alkyl, cycloalkyl, or aralkyl groups containing at least 3 carbon atoms. Preferably R and R1 are alkyl groups containing not more than four carbon atoms. In examples, a mix is made up from pale cr<\>zepe rubber, zinc oxide, lithopone, sulphur, diphenyl guanidine phthalate, benzothiazyl thio benzoate, paraffin, and 3,31 di-n-propyl-4,41-dihydroxy biphenyl added and the antiageing effect noted. Other specified compounds which may be used are those in which R and R1, of the above formula are dimethyl, diethyl, di n-propyl, di isopropyl, di n. butyl, di tert. butyl, di isobutyl, di iso amyl, di tert. amyl, di n. hexyl, di n. heptyl, di n. octyl, di tert. octyl, di lauryl, dicyclohexyl, di cyclopentyl, di gammaphenyl propyl, dibenzyl, di beta phenethyl, and di (alpha-methyl benzyl) groups.