GB842271A - Age-resisters for plastics containing urethane groups - Google Patents

Abstract

The invention comprises a polyurethane foam containing from 0,5% to 10% by weight of an antioxidant which is a polyhydric phenol which may be acylated or etherified and which may contain one or more aromatic ring systems or condensed aromatic ring systems and the hydroxyl groups of which may be partially etherified, 2-mercapto-benzimidazole, zinc dimethyl dithiocarbamate, nickel dibutyl dithiocarbamate or polymerized trimethyl dihydroquinoline (which may be used individually or in admixture) or a mixture consisting of zinc dimethyl dithiocarbamate, nickel dibutyl dithiocarbamate or polymerized trimethyl dihydroquinoline with any of the compounds of the formula: <FORM:0842271/IV(a)/1> Suitable polyhydric phenols are tertiary butyl pyrocatechol, 4, 41-dihydroxy-diphenyl, cyclohexyl pyrocatechol, 2, 4-dihydroxydiphenyl, 2, 4-dihydroxy-benzophenone, 4-hydroxy-5-methoxybenzal acetoacetic ester, pyrocatechol, resorcin, hydroquinone, pyrogallol, 4, 41-dihydroxy-diphenyl-dimethyl methane, 4, 41-dihydroxy-diphenyl methyl ethyl methane. 2, 5-ditertiary butyl hydroquinone, bis (1-oxy-2-tert. butyl-4-ethyl phenyl)-methane, and bis-(1-oxy-2-cyclobexyl-4-methyl-phenyl)-methane. The antioxidant can be added to the reaction mixture as such or in solution in, for example, trichloroethyl phosphate. Examples illustrate the invention as applied to foams prepared from diisocyanates, activator mixtures and respectively a polythioether (from thiodiglycol and butane-dihydroxyethyl glycol), polyesters (linear or branched, and in one case with the addition of butylene-1, 4-glycol), polypropylene glycol, and a branched polythioether (from thiodiglycol, triethylene glycol and trimethylolpropane. Specifications 769,680, 769,682 and 797,576 are referred to.ALSO:The invention comprises a polyurethane foam containing from 0,5% to 10% by weight of an antioxidant which is a polyhydric phenol which may be acylated or etherified and which may contain one or more aromatic ring systems or condensed aromatic ring systems and the hydroxyl groups of which may be partially etherified, 2-mercaptobenzimidazole, zinc di-methyl dithiocarbamate, nickel dibutyl dithiocarbamate or polymerised trimethyl dihydro quinoline (which may be used individually or in admixture) or a mixture consisting of zinc dimethyl dithiocarbamate, nickel dibutyl dithiocarbamate or polymerised trimethyl dihydroquinoline with any of the compounds of the formula: <FORM:0842271/V/1> Suitable polyhydrio phenols are tertiary butyl pyrocatechol, 4,41-dihydroxy-diphenyl cyclohexyl pyrocatechol, 2, 4-dihydroxydiphenyl, 2, 4-dihydroxy-benzophenone, 4-hydroxy-5-methoxybenzol acetoacetic ester, pyrocatechol, resorcin, hydroquinone, pyrogallol, 4, 41-dihydroxy-diphenyl-dimethyl methane, 4, 41-dihydroxy-diphenyl methyl ethyl methane, 2, 5-ditertiary butyl hydroquinone, bis (1-oxy-2-tert butyl-4-ethyl phenyl)-methane, and bis-(1-oxy-2-cyclohexyl-4-methyl-phenyl)-methane. The antioxidant can be added to the reaction mixture as such or in solution in, for example, trichloroethyl phosphate. Examples illustrate the invention as applied to foams prepared from diisocyanates, activator mixtures and respectively a polythioether (from thiodiglycol and butane-dihydroxyethyl glycol), polyesters (linear or branched, and in one case with the addition of butylene-1, 4-glycol), polypropylene glycol and a branched polythioether (from thiodiglycol, triethylene glycol and trimethylol-propane. Specifications 769,680, 769,682 and 797,576 are referred to.