GB870192A - Process for the preparation of alkyl phenols - Google Patents

Abstract

Natural and synthetic rubber compositions comprise as antioxidants alkyl phenols having the structure: <FORM:0870192/IV (a)/1> wherein R is a tertiary octyl, tertiary nonyl, tertiary butyl or tertiary amyl radical, R1 is a tertiary octyl or tertiary nonyl radical and R11 is a tertiary butyl or tertiary amyl radical (see Group IV(b)). Synthetic rubbers specified include polychloroprene, isobutylene and butadiene or isoprene copolymers and butadiene-styrene and butadiene-acrylonitrile copolymers. Compositions are described comprising extracted pale crepe, zinc oxide, sulphur, hexamethylene tetramine, stearic acid and one of the following antioxidants: Products obtained by alkylating phenol with varying proportions of diisobutene and isobutene, 2- 4- di-tertiaryoctyl-6-tertiary butyl phenol, 2 : 6-ditertiary butyl-4-tertiary octyl phenol and the product obtained by alkylating phenol with tripropene and isobutene. Additional compositions are mentioned comprising antioxidants of the invention together with natural rubber, sulphur, zinc oxide, calcium carbonate and stearic acid.ALSO:A process for preparing a mixture of alkyl phenols having the structural formula: <FORM:0870192/IV (b)/1> where R is a tertiary octyl, tertiary nonyl, tertiary butyl or tertiary amyl radical, R1 is a tertiary octyl or tertiary nonyl radical and R11 is a tertiary butyl or tertiary amyl radical, comprises alkylating a tertiary alkyl phenol containing one or two tertiary octyl or tertiary nonyl radicals in the positions ortho and para to the hydroxyl radical with at least one mol of at least one olefin selected from isobutylene and tertiary amylene in the presence of from 0,5 to 10,0% by weight, based on the weight of the reactants, of a catalyst comprising an acid-activated clay and sulphuric acid at a temperature of 50 DEG C. to 90 DEG C. In one form of the process the tertiary alkyl phenol employed as starting material is prepared by alkylating one mol of phenol with at least one mol of one or more tertiary octenes or tertiary nonenes in the presence of from 0,5 to 10% by weight based on the reactants of a catalyst comprising an acid-activated clay or a mixture of an acid activated clay and sulphuric acid at a temperature of 50 to 150 DEG C. and the total amount of olefine used is at least 3 mols per mol of phenol. Examples are furnished. The products are antioxidants for rubber (see Group IV(a)).