GB437674A - Emulsions of asphaltic and like materials - Google Patents

Abstract

A mixed solution of magnesium alkyl sulphates is prepared by treating a 15 per cent solution, containing 50 per cent sodium cetyl, sulphate, 30 per cent sodium stearyl sulphate, and 20 per cent sodium oleyl sulphate, with concentrated magnesium sulphate solution.ALSO:Aqueous bituminous emulsions are prepared with the aid as emulsifying agents of alkali (including ammonium) or alkaline earth metal salts of alkyl sulphuric acids wherein the alkyl radicle is a straight saturated or unsaturated chain of at least eight carbon atoms. The agents are employed in proportions from 0,001 per 10 cent, preferably 0,005 to 2 per cent of the emulsion and the aqueous phase is preferably 30 to 45 per cent of the emulsion. Suitable agents are the salts of n-octyl sulphate, n-nonyl sulphate, n-decyl sulphate, or of lauryl, myristyl, cetyl, or stearyl sulphates. The salts may be employed as such or may be formed in situ from the free acid and the alkali ammonium or alkaline earth oxide or hydroxide. The emulsions may contain, as thickening agents, extenders, pigments, additional emulsifying agents and the like, casein albumen, glue, gelatin, resin, starches, tannin, gums, dextrin, tapioca flour, baryta, iron oxide, carbon black, natural, synthetic or recovered rubber, rosin soap, ordinary soaps such as sodium stearate and oleate, aromatic and aliphatic sulphonic acids and their salts, fatty acids, fats, or oils. Examples: (1) 78 parts of molten asphalt at 120 DEG C. is poured into 20,7 parts of water at 93 DEG C. containing 0,7 parts of a mixture of 50 per cent sodium cetyl sulphate, 40 per cent sodium oleyl sulphate, and 10 per cent sodium stearyl sulphate, and the mixture homogenized in a high-speed mixer (10,000 r.p.m.); the resulting emulsion when cool is stable, too viscous to pour, can be readily diluted with water, and breaks down in about an hour on application to a sand and gravel road bed: (2) 29,0 parts of boiling water containing 0,5 parts of 25 per cent aqueous caustic soda is poured into an intimate mixture of 70 parts of asphalt and 0,5 parts of lauryl sulphate at 120 DEG C., and the mixture homogenized; (3) an emulsion prepared as in (1) contains 50 parts of bitumen, 48 parts of water, and 2 parts of a magnesium alkyl sulphate prepared by treating a 15 per cent solution, containing 50 per cent sodium cetyl sulphate, 30 per cent sodium stearyl sulphate, and 20 per cent sodium oleyl sulphate with concentrated magnesium sulphate; (4) 1 part of the sodium salt mixture referred to in (3), 2 parts of glue or of casein dissolved in boron, 47 parts of water, and 50 parts of bitumen are treated as in (1) and diluted to a bitumen content of 33 per cent; (5) an emulsion similar to that of (1) is diluted with a 4 per cent warm solution of carrageen moss to a stable emulsion of 20 per cent bitumen content; (6) an emulsion prepared as in (1) and containing 50 parts of bitumen, 49 parts of water, and 1 part of mixed alkyl sodium sulphates, is mixed with 50 parts of a pigment suspension containing 8 parts of Monolite Red C and 0,1 part of the same alkyl sodium sulphates; Prussian blue, iron oxide, cadmium yellow, or other white or coloured pigment may alternatively be employed and carrageen moss, glue or other stabilizer may be incorporated. (7) 550 parts of molten bitumen are mixed with a solution containing 5 parts of mixed sodium alkyl sulphates and 5 parts of caustic soda in 440 parts of hot water using a slowspeed agitator and the product homogenized in a colloid mill to produce a highly dispersed emulsion readily breaking in thin films.