Patent GB-951290-A (GB)
Title: Compositions for and processes of removing stains
IPC: C11D3/00
Filed: 1962-05-21
Abstract: A stain removing composition comprises (a) a hydrosulphite, usually the sodium salt although the zinc salt may also be used, (b) an organic buffer, and (c) an activating agent, the mixture with water having a pH of 5-10. (b) is suitably acetic acid, a hydroxycarboxylic acid such as citric acid, dihydroxyethylaminoacetic acid or an aminopolycarboxylic acid having more than one carboxyl group in the alpha position to a N atom, and/or water-soluble salts of such acids. (c) may be a dihydroxyquinone, a 2-hydroxynaphthoquinone, a substituted dihydroxyquinone or a 3-substituted - 2 - hydroxynaphthoquinone, the substituents being OH, Cl, Br or NO2; the corresponding hydroquinones; hydroxybenzoic or substituted hydroxybenzoic acid, the substituents being OH or NH2; or salts thereof, e.g. the sodium, cupric, ferric or aluminium salts.  As buffer (b), sodium citrate and tetrasodium ethylene diamine tetra-acetate are preferred; as activator (c) chloranilic acid is favoured.  The composition generally also contains (d) an abrasive such as silica, ground quartz, feldspar, pumice, chalk, tripoli, kieselguhr or diatomaceous earth and (e) soap or other organic anionic, cationic or nonionic detergents, especially one produced by spray-drying a mixture of an alkali metal C8-18-alkyl benzene sulphonate, sodium silicate and sodium sulphate.  The composition normally comprises by weight 0.5-10% of (a), 1-20% of (b) of which 1-10% comprises the non-chelating type of buffer and 0-10% comprises the chelating type, 0.1-5% of (c), 65-98% of (d), and 0-10% of (e); 0-0.5% perfume may also be present.  In the preferred composition, for each part by weight of sodium hydrosulphite there is present 0.01-10 parts chloranilic acid and 0.1-20 parts sodium citrate. The composition is usually formulated as a powder, but if required may be prepared as an aqueous solution or slurry by mixing when required for use. If desired, (c) may be dispersed before addition in an extender such as powdered calcium carbonate.ALSO:A stain removing composition comprises (a) a hydrosulphite, usually the sodium salt although the zinc salt may also be used, (b) an organic buffer, and (c) an activating agent, the mixture with water having a pH of 5-10 (b) is suitably acetic acid, a hydroxycarboxylic acid such as citric acid, dihydroxyethylaminoacetic acid or an aminopolycarboxylic acid having more than one carboxyl group in the alpha position to a N atom, and/or water soluble salts of such acids (c) may be a dihydroxyquinone, a 2-hydroxynaphthoquinone, a substituted dihydroxyquinone or a 3-substituted-2-hydroxynaphthoquinone, the substituents being OH, Cl, Br or NO2; the corresponding hydroquinones; hydroxybenzoic or substituted hydroxybenzoic acid, the substituents being OH or NH2; or salts thereof, e.g. the sodium, cupric, ferric or aluminium salts.  As buffer (b), sodium citrate and tetrasodium ethylene diamine tetra-acetate are preferred; as activator (c) chloranilic acid is favoured.  The composition generally also contains (d) an abrasive such as silica, ground quartz, feldspar, pumice, chalk, tripoli, kieselguhr or diatomaceous earth and (e) soap or other organic anionic, cationic or nonionic detergents, especially one produced by spray-drying a mixture of an alkali metal C8-18-alkyl benzene sulphonate, sodium silicate and sodium sulphate.  The composition normally comprises by weight 0.5-10% of (a), 1-20% of (b) of which 1-10% comprises the non-chelating type of buffer and 0-10% comprises the chelating type, 0.1-5% of (c), 65-98% of (d), and 0-10% of (e); 0-0.5% perfume may also be present.  In the preferred composition, for each part by weight of sodium hydrosulphite there is present 0.01-10 parts chloranilic acid and 0.1-20 parts sodium citrate.  The composition is usually formulated as a powder, but if required may be prepared as an aqueous solution or slurry by mixing when required for use.  If desired, (c) may be dispersed before addition in an extender such as powdered calcium carbonate.