GB711562A - Improvements in and relating to stabilised unvulcanised rubber - Google Patents

Abstract

Compositions which comprise soft, hydro-carbon-soluble, unvulcanized rubber are stabilized against oxidation by the presence in the compositions of polyfunctional aminoacetic acids or salts or esters thereof, or nitrolotriacetic acid or a salt or ester thereof, e.g. aminodiacetic acid, ethylenediamine di-, tri- or tetraacetic acids, butylenediamine diacetic acid, trisodium, tetrasodium, potassium, triethanolamine and mono-n-butylamine salts of triethylenediamine tetraacetic acid, the n-butyl ester of ethylenediamine tetraacetic acid, the diethylamine salt of propylenediamine tetraacetic acid, the mono-n-pentylamine salt of nitrilotri-acetic acid. The amount of such stabilizer may be 0.05-10 per cent. of the composition. The rubber component of the composition is exemplified by natural rubber with polyisobutylene of mol. wt. 100,000, a butadiene (66 per cent.)-acrylonitrile (34 per cent.) copolymer, a butadiene (50 per cent.)-styrene (50 per cent.) copolymer, a mixture of these copolymers in equal parts, employed as latices. The composition may contain also a tackifying or other compatible resin, a plasticizer such as lanolin, mineral oil, petroleum jelly, naphthenic oil, a filler such as finely-divided clay, finely-divided clay with titanium dioxide, zinc oxide, aluminium hydrate, calcium carbonate, and a standard antioxidant such as hydroquinone n-benzyl ether or diamyl hydroquinone.ALSO:Compositions, especially pressure-sensitive adhesives, which comprise soft, hydrocarbon-soluble, unvulcanized rubber are stabilized against oxidation and consequent hardening and loss of tackiness by the presence in the compositions of a polyfunctional aminoacetic acid or a salt or ester thereof, or nitrilotriacetic acid or a salt or ester thereof, e.g. aminodiacetic acid, ethylenediamine diacetic acid, ethylenediamine triacetic acid, ethylenediamine tetraacetic acid, butylenediamine diacetic acid, the trisodium or tetrasodium salt of ethylenediamine tetraacetic acid, the potassium salt of ethylenediamine tetraacetic acid, the triethanolamine salt of ethylenediamine tetraacetic acid, the mono-n-butylamine salt of ethylenediamine tetraacetic acid, the diethylamine salt of propylenediamine tetraacetic acid, the n-butyl ester of ethylenediamine tetraacetic acid, the mono-n-pentylamine salt of nitrilotriacetic acid. The amount of such stabilizer may be 0.05-10 per cent. of the composition, and is preferably 0.2-2 per cent. the rubber component of the composition is exemplified by natural rubber, e.g. smoked sheet, natural rubber with polyisobutylene of mol. wt. 100,000, white factice, devulcanized reclaim rubber, or reprocessed natural unvulcanized rubber, a butadiene (66 per cent.)-acrylonitrile (34 per cent.) copolymer, a butadiene (50 per cent.)-styrene (50 per cent.) copolymer, and a mixture of latices of these copolymers. The composition may contain also a tackifying or other compatible resin such as polybetapinene (m.pt. 115 DEG C.), polybetapinene with rosin (m.pt. 120 DEG C.), dehydrogenated rosin (m.pt. 62 DEG C.), hyrogenated rosin (m.pt. 110 DEG C.), glyceride of hydrogenated rosin (m.pt. 120 DEG C.), coumarone-indene resin (m.pt. 80 DEG C.), coumarone-indene resin with polybetapinene, a plasticizer such as lanolin, mineral oil, petroleum jelly, naphthenic oil, a filler such as finely-divided clay, finely-divided clay with titanium dioxide, zinc oxide, aluminium hydrate, calcium carbonate, and a standard antioxidant such as hydroquinone n-benzyl ether or diamyl hydroquinone.