Patent GB-563479-A (GB)
Title: New antioxidant composition
IPC: C11B5/00
Filed: 1942-09-24
Abstract: An anti-oxidant composition comprises an alkylated diarylamine and a condensation product of a diarylamine with a conjugated diolefin of less than eight carbon atoms made in the presence of an acidic catalyst.  It may be incorporated in any suitable way with organic materials to be preserved against deterioration in the presence of oxygen such as fish oil, linseed oil, tung oil, gasoline, natural rubber, including balata and guttapercha, and synthetic rubbers such as polychloropene and copolymers of butadiene, isoprene, 2,3-dimethylbutadiene or piperylene with acrylonitrile, styrene, methyl acrylate, methyl methacrylate or isobutene.  The condensation products are usually prepared at 50-300 DEG  C. and ordinary or increased pressures with the reactants present in molecular ratio of not more than 6 : 1, preferably with a ratio of diarylamine to diolefin of 2 : 1 and of catalyst to diarylamine of 0.1 : 1.  Thus, diphenylamine and butadiene-1.3 are p  reacted with zinc chloride in these proportions for 4-5 hours in an autoclave at 200 DEG  C.  After washing with water and caustic soda, and distilling off unused reactants, a dark liquid results which crystallizes on standing. These crystals can be separated into three compounds: p-(2-butenyl) diphenylamine, and what are believed to be an anilino-methyl indane, and p,p1-di-(2-buteryl) diphenylamine.  Other conjugated diolefines which can be used include piperylene, 2-methyl or 2,3-dimethyl butadiene or pentadiene-1,3, hexadiene-1,3 or 2,4, and heptadiene-1,3 or 2,4, and diarylamines include phenyl-a  or b -naphthylamine, ditolylamines, phenyltolylamines, dinaphthylamines, anilino-tetraphenylmethane, phenyl-p-xenylamine, dixenylamine, dianilino-diphenylmethane, p-hydroxydiphenylamine, p-aminodiphenylamine, N,N1-diphenylp-phenylenediamine, anilino-biphenylene oxide, anilino-acridine, 6-anilino-quinoline, p-chlordiphenylamine, and p-isopropoxydiphenylamine, or mixtures of these.  Catalysts include HCI, H3PO4, H2SO4, NaHSO4, AlCl3, BF3, SnCl4, NH4Br, and I2. Alkylated diarylamines may be prepared by reaction of alkylated arylamines with hydroxy aryl compounds or of diarylamines with aliphatic alcohols or mono-olefins in presence of acid catalysts. Mono-olefins include ethylene, propene, butene, pentene, cracked gasolines, pinene, cyclohexene, and aralkenyl compounds of mono-olefinic type such as styrene and indene.  The anti-oxidant mixtures exhibit a synergistic effect which is only appreciable when the amount of one component is at least 1/6 th that of the other.  Examples show the effect on tensile strength and elongation before and after aging of a vulcanized rubber composition containing:-(a) the reaction product of diphenylamine and butadiene above described; (b) of diphenylamine and a cracked gasoline fraction boiling at 70-105 DEG  C., mainly heptenes, condensed in equimolecular proportions using zinc chloride at 200 DEG  C.; (c) a mixture of equal proportions of (a) and (b); (d) the reaction product of molar proportions of diphenylamine and pentene-2 prepared with zinc chloride at 200 DEG  C.; (e) a mixture of 1 part of (a) to 2 of (d) by weight, and demonstrate the superior anti-oxidant properties of the mixtures over the separate components.  A mixture of equal amounts of (a) and the reaction product of diphenylamine and di-isopropyl carbinol is about as effective as (c).  A similar example shows the anti-oxidant effect on a butadiene-acrylonitrile synthetic rubber composition containing zinc oxide, titanium dioxide and coumarone-indene resin of a mixture in equal amounts of the reaction products of diphenylamine with butadiene, with butene-2, and with di-isopropyl carbinol.  The rubber compositions are fast to light and may include the usual compounding ingredients. Specification 410,274, [Group III], is referred to.ALSO:An anti-oxidant composition comprises an alkylated diarylamine and a condensation product of a diarylamine with a conjugated diolefin of less than eight carbon atoms made in the presence of an acidic catalyst.  It may be incorporated in any suitable way with organic materials to be preserved against deterioration in the presence of oxygen such as fish oil, linseed oil, tung oil, gasoline, natural rubber including balata and guttapercha, and synthetic rubbers such as polychloroprene and copolymers of butadiene, isoprene, 2, 3-dimethylbutadiene or piperylene with acrylonitrile, styrene, methyl acrylate, methyl methacrylate or isobutene.  The condensation products are usually prepared at 50-300 DEG  C. and ordinary or increased pressures with the reactants present in molecular ratio of not more than 6 : 1 preferably with a ratio of diarylamine to diolefin of 2 : 1 and of catalyst to diarylamine of 0.1 : 1.  Thus, diphenylamine and butadiene-1.3 are reacted with zinc chloride in these proportions for 4-5 hrs. in an autoclave at 200 DEG  C.  After washing with water and caustic soda, and distilling off unused reactants, a dark liquid results which crystallizes on standing. These crystals can be separated into three compounds: p-(2-butenyl)diphenylamine, and what are believed to be an anilino-methyl indane, and p,p1-di-(2-butenyl)diphenylamine.  Other conjugated diolefins which can be used include piperylene, 2-methyl or 2,3-dimethyl butadiene or pentadiene-1, 3, hexadiene-1, 3 or 2, 4, and heptadiene-1, 3 or 2, 4, and diarylamines include phenyl-a  or b -naphthylamine, ditobylamines, phenyltolylamines, dinaphthylamines, anilino-tetraphenylmethane, phenyl-p-xenylamine, dixenylamine, dianilino-diphenylmethane, p - hydroxy - diphenylamine, p - aminodiphenylamine, N1 N1 - diphenyl - p - phenylenediamine, anilino-biphenylene oxide, anilino-acridine, 6-anilino-quinoline, condensed in aquimolecular proportions using zinc chloride at 200 DEG C.; (c) a mixture of equal proportions of (A) and (B); (D) the reaction product of molar proportions of diphenylamine and pentene-2 prepared with zinc chloride at 200 DEG  C.; (E) a mixture of 1 part of (A) to 2 of (D) by weight, and demonstrate the superior antioxidant properties of the mixtures over the separate components. A mixture of equal amounts of (A) and the reaction product of diphenylamine and di-isopropyl carbinol is about as effective as (C). A similar Example shows the anti-oxidant effect on a butadiene-acrylonitrile synthetic rubber composition containing zinc oxide, titanium dioxide and coumarone-indene resin of a mixture in equal amounts of the reaction products of diphenylamine with butadiene, with butene-2, and with di-isopropyl carbinol.  The rubber compositions are fast to light and may include the usual compounding ingredients.  Specification 410,274 is referred to.