Patent GB-483605-A (GB)
Title: Improvements in or relating to the preservation of rubber
IPC: C08K5/18
Filed: 1937-03-30
Abstract: The deterioration of rubber due to age is retarded by the addition to the mix of a substituted diaryl arylene diamine containing as a substituent at least one alkyl group of more than 3 carbon atoms or an aralkyl group.  The substituting alkyl or aralkyl group may be attached to an aromatic radical or to a nitrogen atom.  The compound may contain several such substituents.  The compounds are represented by the general formula X1-R-NH-R-NH-R-X where R represents an aromatic radical, X represents an alkyl group of more than 3 carbon atoms, and X1 represents hydrogen, an alkyl group of more than 3 carbon atoms or an aralkyl group.  The compounds may be prepared by reacting a diaryl arylene diamine, with an alkyl halide in which the alkyl group contains more than 3 carbon atoms or with an aralkyl halide.  The reaction may, and preferably does, take place in the presence of a condensing agent, the nature of which influences the nature of the product obtained.  Suitable condensing agents include anhydrous zinc chloride which favours the entry of the alkyl or aralkyl group into the aromatic nucleus in the para position to the nitrogen, and aqueous sodium hydroxide, which produces a substitution of the alkyl or aralkyl group for the hydrogen of the amino groups. The products are also influenced by the proportions in which the reactants are mixed. Suitable diaryl arylene diamines mentioned include, diphenyl-p-phenylene diamine, di-beta-naphthyl-p-phenylene diamine and di-beta-naphthyl benzidine.  Suitable aralkyl and alkyl halides are benzyl-, n-butyl-, and amyl chlorides.  In examples; (1) Equi-molecular amounts of diphenyl-p-phenylene diamine, and benzyl chloride are reacted in the presence of anhydrous zinc chloride fo 2-3 hours at 150-160 DEG  C., and the product treated with water to give a compound of the formula <FORM:0483605/IV/1> (2) Similar to example (1) but using double the amount of benzyl chloride; (3) Similar to example (1) using amyl chloride in place of benzyl chloride; (4) Similar to example (1) using butyl chloride in place of benzyl chloride; (5) Similar to example (1) using di-beta-naphthyl-p-phenylene diamine in place of diphenyl-p-phenylene diamine; (6) Similar to example (1) using ditolyl-p-phenylene diamine in place of diphenyl-p-phenylene diamine; (7) Two separate antioxidants are prepared by reacting one mol. of diphenyl-p-phenylene diamine with respectively one and two mols. of benzyl chloride in the presence of aqueous sodium hydroxide. Specifications 296,398 and 312,630, [both in Class 70], are referred to.ALSO:The deterioration of rubber due to age is retarded by the addition to the mix of a substituted diaryl arylene diamine containing as a substituent at least one alkyl group of more than three carbon atoms or an aralkyl group.  The substituting alkyl or aralkyl group may be attached to an aromatic radical or to a nitrogen atom.  The compound may contain several such substituents.  The compounds are represented by the general formula X1-R-NH-R-NH-R-X where R represents an aromatic radical, X represents an alkyl group of more than three carbon atoms, and X1 represents hydrogen, an alkyl group of more than three carbon atoms or an aralkyl group.  The compounds may be prepared by reacting a diaryl arylene diamine with an alkyl halide in which the alkyl group contains more than three carbon atoms or with an aralkyl halide.  The reaction may, and preferably does, take place in the presence of a condensing agent, the nature of which influences the nature of the product obtained. Suitable condensing agents include anhydrous zinc chloride, which favours the entry of the alkyl or aralkyl group into the aromatic nucleus in the para position to the nitrogen, and aqueous sodium hydroxide which produces a substitution of the alkyl or aralkyl group for the hydrogen of the amino groups.  The products are also influenced by the proportions in which the reactants are mixed. Suitable diaryl arylene diamines mentioned include diphenyl-p-phenylene diamine, di - beta - naphthyl - p - phenylene diamine, and di - beta - naphthyl benzidine.  Suitable aralkyl and alkyl halides are benzyl, n-butyl-, and amyl chlorides.  In examples: (1) equimolecular amounts of diphenyl-p-phenylene diamine and benzyl chloride are (2) similar to example (1) but using double the amount of benzoyl chloride; (3) similar to example (1) but using amyl chloride in place of benzyl chloride; (4) similar to example (1) using butyl chloride in place of benzyl chloride; (5) similar to example (1) using di-beta-naphthyl-p-phenylene diamine in place of diphenyl-p-phenylene diamine; (6) similar to reacted in the presence of anhydrous zinc chloride for 2-3 hours at 150-160 DEG  C., and the product treated with water to give a compound of the formula <FORM:0483605/V/1> example (1) using ditolyl-p-phenylene diamine in place of diphenyl-p-diamine; (7) two separate anti-oxidants are prepared by reacting one mol. of diphenyl-p-phenylene diamine with respectively one and two mols. of benzyl chloride in the presence of aqueous sodium hydroxide.  Specifications 296,398 and 312,630, [both in Class 70], are referred to.