GB798872A - Process for improving the adhesion of bituminous or other hydrocarbon binders to solid materials - Google Patents

Abstract

An aqueous dispersion of a water-insoluble amino compound, in which the dispersing agent is an anionic surface active metal salt or sodium or potassium carbonate or bicarbonate, is used for pretreating a solid material in order to improve the adhesion thereto of a bituminous or other hydrocarbon binder (see Group V). The amino compound may be (a) a higher alkyl or alkenyl amine, e.g. hexadecylamine, heptadecylamine octadecylamine, or octadecenylamine or a polyalkylene polyamine; (b) an amide obtained by condensing ammonia or an amine with a long chain organic acid, e.g. oleic, linoleic, or stearic acid, naphthenic acids, or tall oil acids; (c) an acylamidoamine obtained by condensing a long chain organic acid as in (b) with a polyamine, e.g. ethylene diamine, propylene diamine, diethylene triamine, triethylene triamine, tetraethylene pentamine, hexamethylene diamine, or a polyamine obtained by hydrogenation of the condensation product of acrolein or epichlorhydrin with ammonia; or (d) a tertiary amine containing an alkyl group and two polyoxyethylene groups. The anionic surface-active agent may be a higher fatty acid soap, an organic sulphate or sulphonate, a resinate or naphthenate, e.g. sodium resinate derived from tall oil or secondary alkyl sulphates derived from cracked paraffin wax. The amino compound may be present in the dispersion in an amount of 1-30 per cent by weight and the dispersing agent in an amount of 1-10 per cent by weight.ALSO:In order to improve the adhesion between a solid material and a bituminous or other hydrocarbon binder, the solid material is pretreated with an aqueous dispersion of a water-insoluble amino compound, the dispersing agent being an anionic surface-active metal salt or sodium or potassium carbonate or bicarbonate (see Group III). A suitable proportion of the amino compound is 0,01-1 part per 1000 parts by weight of the solid material. The dispersion is especially suitable for coating a basic aggregate, e.g. limestone, or a porous aggregate, e.g., quartzite mixed with clay. Granite feldspar, metals, glass and cement are other solid materials mentioned. An alkaline filler, e.g., lime, magnesium oxide, or barium hydroxide, may be mixed with the aggregate. The bituminous binder may be used in an amount of 0,5-10 per cent by weight of the aggregate and may be, for example, straight run bitumen, blown bitumen, natural asphalt, pitch, or wood or coal tar, it may be applied as a cutback or an aqueous dispersion. The aqueous dispersion of the amino compound may be applied to the aggregate by spraying or other methods. A wet road surface may be treated with the dispersion before spreading a new layer of binder. Gravel containing a high proportion of fine particles may be pretreated with a part of the total amount of aqueous dispersion, the rest of the aqueous dispersion being added after the binder.