Patent GB-561999-A (GB)
Title: Improvements in the preservation of rubber and other oxidizable organic compounds and articles made therefrom
IPC: C08K5/18
Filed: 1942-09-24
Abstract: Antioxidants for rubber, synthetic rubber and like substances, or for fish oils, linseed oil, tung oil, gasolines, &c., comprise a mixture of an alkylated diarylamine and the product obtained by condensing an open chain conjugated diolefine of less than 8 carbon atoms with a diarylamine in the presence of an acid condensation catalyst. Examples of conjugated diolefines are butadiene-1,3; piperylene; isoprene; 2-methyl pentadiene-1,3; 2,3-dimethyl butadiene-1,3; 2,3-dimethyl pentadiene-1,3; hexadienes and heptadienes, etc.; and examples of diarylamines are diphenyl-, ditolyl-, dinaphthyl-, and dixenylamines, phenyl-a - and phenyl-b -naphthylamines, phenyltolyl-, and phenyl-p-xenylamines, anilino-tetraphenylmethane, dianilino-diphenylmethane, p-hydroxy-, and p-amino - diphenylamines N,N1 - diphenyl - p - phenylenediamine, anilino-biphenylene oxide, anilino-acridine, 6-anilino-quinoline, p-chlorodiphenylamine, p - isopropoxydiphenylamine-, and reaction products of diarylamines with alcohols, aldehydes and ketones. Examples of catalysts include HCl, H3PO4, H2SO4, NaHSO4, ZnCl2, AlCl3, BF3, SnCl4, NH4Br, and I2. The reaction which is carried out at 50 to 300 DEG C. and at atmospheric or elevated pressure, yields a mixture of substances, some of uncertain constitution. In an example, butadiene (1 mol.) is reacted at 200 DEG C. for 4 to 5 hours with diphenylamine (2 mols.) using zinc chloride, the mixture washed and unreacted components distilled off, 2 parts of the product per 100 of rubber being used in a mix including carbon black, zinc oxide and other usual ingredients. The antioxidants may be used in solution and may be added in a mixer, dispersed in rubber latex or applied to the surface of a rubber composition.  Specification 555,233 is referred to.ALSO:Antioxidants for rubber, synthetic rubber and like substances, or for fish oils, linseed oil, tung oil, gasolines, &c., comprise a mixture of an alkylated diarylamine and the product obtained by condensing an open chain conjugated diolefine of less than 8 carbon atoms with a diarylamine in the presence of an acid condensation catalyst. Examples of conjugated diolefines are butadiene-1,3; piperylene; isoprene; 2-methyl pentadiene-1,3; 2,3-dimethyl butadiene-1,3; 2,3-dimethyl pentadiene-1,3; hexadienes and heptadienes etc.; and examples of diarylamines are diphenyl-, ditolyl-, dinaphthyl-, and dixenyl-amines, phenyl-a -, and phenyl-b -naphthylamines, phenyltolyl-, and phenyl - p - xenylamines, anilino - tetraphenylmethane, dianilino - diphenylmethane, p - hydroxy-, and p-amino-diphenylamines, N,N1-diphenyl-p-phenylenediamine, anilino-biphenylene oxide, anilino-acridine, 6-anilino-quinoline, p-chloro-diphenylamine, p-isopropoxydiphenylamine, and reaction products of diarylamines with alcohols, aldehydes and ketones. Examples of catalysts include HCl, H3PO4, H2SO4, NaHSO4, ZnCl2, AlCl3, BF3, SnCl4, NH4Br, and I2. The reaction which is carried out at 50 to 300 DEG  C. and at atmospheric or elevated pressure, yields a mixture of substances, some of uncertain constitution.  In an example, butadiene (1 mol.) is reacted at 200 DEG  C. for 4 to 5 hrs. with diphenylamine (2 mols.) using zinc chloride, the mixture washed and unreacted components distilled off, 2 parts of the product per 100 of rubber being used in a mix including carbon black, zinc oxide and other usual ingredients.  The antioxidants may be used in solution and may be added in a mixer, dispersed in rubber latex or applied to the surface of a rubber composition.  Specification 555,233, [Group IV], is referred to.