Patent GB-857119-A (GB)
Title: Urea-phosphoric acid cleaning composition
Inventor: LITTLE LAWRENCE L
IPC: C11D3/00
Filed: 1958-09-10
Abstract: A solid addition product between urea and phosphoric acid is obtained by mixing urea or an aqueous solution thereof with concentrated phosphoric acid in the ratio of 1 part by weight of urea to 2 parts by weight of phosphoric acid.ALSO:Metal apparatus, especially that used in food industries, is cleaned by immersion in a hot aqueous solution of the solid addition product of urea and concentrated phosphoric acid, having a pH below 4.7 and obtained by dissolving urea in said phosphoric acid in the ratio of 1:2 by weight.  The cleaning is preferably assisted by means of a scrubbing action and after removal of the spent solution the apparatus is preferably rinsed with hot water. Other substances may be added to the cleaning solution, viz. cationic wetting agents, e.g. alkyl dimethyl benzyl ammonium chlorides, alkyl trimethyl ammonium chlorides, alkyl benzene p  trimethyl ammonium chlorides, and di-isobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride; non-ionic wetting agents, e.g. polyglycol ethers, quaternary ammonium germicidal wetting agents, and solid, crystalline or powdered acids, acid salts or salts of polyvalent metals, e.g. boric or citric acid, monosodium phosphate, ammonium nitrate, calcium lactate or acetate, magnesium lactate and aluminium lactate or nitrate.ALSO:Metal apparatus, especially that used in food industries, is cleaned by immersion in a hot aqueous solution of the solid addition product of urea and concentrated phosphoric acid, having a pH below 4.7 and obtained by dissolving urea in said phosphoric acid in the ratio of 1 : 2 by weight.  The cleaning is preferably assisted by means of a scrubbing action and after removal of the spent solution the apparatus is preferably rinsed with hot water. Other substances may be added to the cleaning solution, viz. cationic wetting agents, e.g. alkyl dimethyl benzyl ammonium chlorides, alkyl trimethyl ammonium chlorides, alkyl benzene trimethyl ammonium chlorides, and di-isobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride; non-ionic wetting agents, e.g. polyglycol ethers, quaternary ammonium germicidal wetting agents, and solid, crystalline or powdered acids, acid salts or salts of polyvalent metals, e.g. boric or citric acid, monosodium phosphate, ammonium nitrate, calcium lactate or acetate, magnesium lactate and aluminium lactate or nitrate.ALSO:Metal apparatus, especially that used in food industries, is cleaned by immersion in a hot aqueous solution of the solid addition product of urea and concentrated phosphoric acid, having a pH below 4,7 and obtained by dissolving urea in said phosphoric acid in the ratio of 1:2 by weight.  The cleaning is preferably assisted by means of a scrubbing action and after removal of the spent solution the apparatus is preferably rinsed with hot water.  Other substances may be added to the cleaning solution, viz. cationic wetting agents, e.g. alkyl dimethyl benzyl ammonium chlorides, alkyl trimethyl ammonium chlorides, alkyl benzene trimethyl ammonium chlorides, and di-isobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride; non-ionic wetting agents, e.g. polyglycol ethers, quaternary ammonium germicidal wetting agents, and solid, crystalline or powdered acids, acid salts or salts of polyvalent metals, e.g. boric or citric acid, monosodium phosphate, ammonium nitrate, calcium lactate or acetate, magnesium lactate and aluminium lactate or nitrate.