Patent GB-1182143-A (GB)
Title: Bleaching Compositions and Methods.
Inventor: WOODS WILLIAM GEORGE
IPC: C11D3/39
Filed: 1967-02-21
Abstract: 1,182,143. Detergent bleach. UNITED STATES BORAX & CHEMICAL CORP. 21 Feb., 1967 [1 March, 1966], No. 8253/67. Heading C5D. [Also in Division D1] A detergent composition comprises an inorganic per salt bleaching agent, a watersoluble salt or oxide of chromium, manganese, iron, cobalt, nickel or copper, a chelating agent stable under oxidizing conditions and having at 20‹ C. a pK. of 2-10 with the metal, the pK, being the logarithm to base 10 of the first complex formation constant, and a per salt activator which is a carboxylic acid anhydride, a substituted phenyl ester of an aliphatic acid having at least one electronegative substituent on the phenyl ring, an N,N-diacyl compound or an acyl cyanurate, in the molar proportions: per salt 1, metal salt or oxide 0À0005-0À01, chelating agent 0À001-0À1 and per salt activator 0À05-1À5. The per salt may be an alkali metal perborate, persulphate, percarbonate, perpyrophosphate or persilicate and the metal salt may be a chloride, sulphate, nitrate, perchlorate or acetate. The chelating agent may be pyrrolidine - 2 - carboxylic acid, pyridine - 2,6 - dicarboxylic acid, picolinic acid, 6-methylpicolinic acid, isonicotinic acid, quinolinic acid, isocinchomeronic acid, 1,10-phenanthroline or an alkyl substituted derivative thereof or 2,2<SP>1</SP>-bipyridine. Suitable per salt activators are succinic, phthalic, adipic, benzoic, glutaric or acetic anhydride, sodium p-acetoxy- or pbutyroxy-benzene sulphonate, acetyl- or chloroacetyl-salicylic acid, p-acetoxybenzoic acid, N,N-diacetylaniline, tri- or tetra-acetyl methylenediamine, tetra-acetyl-hydrazine, di- or trisacetylcyanurate or trispropionyl cyanurate. The composition may comprise a soap or synthetic detergent, water softeners, anti-redeposition agents and corrosion inhibitors, suitable detergent compositions comprising sodium dodecylbenzene sulphonate, sodium lauric acid isethionate, lauryl alcohol, the monoethanolamide of coconut oil fatty acid, sodium tripolyphosphate, sodium silicate, carboxymethyl cellulose, sodium sulphate and an optical brightener or nonylphenol condensed with 9 molecules of ethyleneoxide, sodium tripolyphosphate, sodium silicate, carboxymethyl cellulose, sodium sulphate and an optical brightener. The composition is preferably packaged so that the unchelated metal compound is kept separate from the per salt, and the per salt activator may be protected from environmental moisture by encapsulating particles or droplets thereof in gelatine, ethyl cellulose or an emulsifiable wax. The metal compound may be mixed with the activator and encapsulated or reacted with the chelating agent prior to mixing it with the detergent and per salt. Alternatively composite tablets containing the detergent, per salt, activator, metal compound and chelating agent may be used or the composition packaged in two separate packets made of polyethylene, polyethylene terephthalate, polyvinyl chloride or ethyl cellulose, the activator and metal compound being placed in one packet and the detergent, per salt and chelating agent in the other.