AQUEOUS ANTIFOAMING EMULSIONS

摘要

1402597 Aqueous antifoaming emulsions; clay dispersion BADISCHE ANILIN- & SODAFABRIK AG 16 Nov 1972 [17 Nov 1971] 52966/72 Headings C1A and C1C [Also in Divisions B1 C6 and D2] A coating composition of water content 50% comprises 100 parts coating clay, 0À3 part of a polyacrylate, 0À15 part sodium hydroxide, 4 parts casein, 11 parts of an aqueous dispersion based on acrylic acid and methacrylate and is highly foaming. The amount of foam produced is reduced by addition to 4 litres of the composition of 1 gm of an emulsion comprising 25 parts C 16-18 "Alfol" cut (Alfol is a Registered Trade Mark), 15 parts stearic acid, 5 parts sperm oil fatty alcohol ethoxylated with 25 moles ethylene oxide and 55 parts water, the average particle size of the emulsified waterinsoluble portions of the emulsion being from 4 to 7 microns. Foaming in the aerating basins of a biological sewage plant in which the water to be treated contains up to 1% sewage sludge is reduced by adding to the sewage entering the basin 5 c.c./m.3 of an emulsion comprising 26% C 16 to C 18 fatty alcohol, 4% paraffin oil, 5% ethoxylated oleic acid containing 8 moles of ethylene oxide and 65% water, the average particle size of the emulsified water-insoluble portions of the emulsion being 6 microns.