Patent GB-1395543-A (GB)
Title: Drying of detergents
IPC: C11D1/22
Filed: 1972-07-21
Abstract: 1395543 Preparation of detergent compositions COLGATE-PALMOLIVE CO 21 July 1972 [27 July 1972] 34302/72 Heading C5D [Also in Division F4] An aqueous solution (or suspension) of a detergent salt is dried by mixing with a sorbent (adsorbent or absorbent) particulate solid material, and moisture is removed from the mixture by applying a vacuum or heated air. In Fig. 1, the (pre-heated) sorbent particles are admitted continuously or in batches via 29 and the detergent solution via 31 and 33, to a (heated) stationary drum 13 containing ploughs 15, 17 and scrapers 21, 23 driven by a motor 19, and choppers 25, 27 driven by their own motors. The mixture is passed to a flash evaporator 37 held under vacuum (or tray dryer, or fluidized bed), and then to a classifying cyclone 45 or settler. In Fig. 2 (not shown), heated drying air is supplied to the drum, and vapour can escape through a cloth sock filter at the top of the drum. The cyclone or settler may be omitted. In Fig. 3 (not shown), mixing is effected by a horizontal helical screw rotating in an open trough. The detergent may be anionic, cationic, non- ionic, amphoteric or ampholytic, or comprise mixtures thereof. Preferred anionic detergent salts include branched or straight chain higher alkyl benzene sulphonates, e.g. linear dodecyl benzene sulphonate, of e.g. sodium. Others include higher alkyl sulphates, alkyl sulphonates, acryl sarcosides, acryl N-methyl tauirdes, alkyl alkoxy sulphites, alkyl pnenoxy ethoxy ethanol sulphates, or mixtures thereof. Preferred non-ionic detergents include copolymers of ethylene oxide and propylene oxide, higher alkyl ethers of aloxy alkanols, alkyl phenoxy polyethoxy ethanols, and fatty acid esters of alkoxy alkanols. Preferred cationic detergents include cetyl trimethyl ammonium bromide, dioctyl dimethyl ammonium chloride, pyridinium halides, benzethionium chloride. The sorbent may be a builder or a filler salt, e.g. trisodium phosphate, pentasodium tripolyphosphate, tetrasodium pyrophosphate, sodium carbonate, sodium bicarbonate, borax, boric acid, sodium sulphate, sodium bisulphate, disodium phosphate, monosodium phosphate, or other water-soluble potassium or ammonium salts. The sorbent may be a scouring material, e.g. powdered silica, talc, calcium silicate, pumice or tricalcium phosphate. The sorbent may be a slip-promoting agent, e.g. talc or magnesium silicate, e.g. talc, a bulk-increasing material, e.g. alpha cellulose and asbestos, or an anti-redeposition agent, e.g. polyvinyl alcohol and sodium carboxymethyl cellulose. The mixture may include adjuvants, e.g. nitrilotriacetic acid and ethylene diamine tetracetic acid, trichloroisocyanuric acid, enzymes, sodium perborate, sodium bromide, bulking materials, pH regulators, brighteners, foaming agents, fungicides, bactericides, perperfumes, colorants, viscosity enhancing compounds, and soil-suspending and anti-redeposition agents. The adjuvant content is < 20%, preferably < 10%, of the weight of the dried product. The detergent content is 2-30% preferably from 5 to 20% by weight of the dried product. The weight of sorbent is between 1 and 40 times, preferably 6-14 times, the weight of detergent. The final moisture content is 0À1 to 10%, preferably 0À1 to 2%. The detergent content of the solution is 10-75%, preferably 30-65%. The sorbent may be removed mechanically after drying. Detergent materials of the monoglyceride sulphate, tallow alcohol sulphate, lauryl polyoxyethylene sulphate, olefin sulphonate and idoctyl sulphosuccinate types as sodium or potassium salts, may be substituted for 50% of the solids content of the mixture.