Patent GB-836988-A (GB)
Title: Improvements in or relating to bleaching and detergent compositions
Inventor: DAVIES THOMAS DANIEL
IPC: D06L4/12
Filed: 1955-07-27
Abstract: A detergent composition comprises (1) soap or a synthetic detergent such as an alkyl sulphate, alkylaryl sulphonate, or isethionate, (2) an inorganic per-salt, and (3) an organic carboxylic ester having, in a test which is described in detail, a titre of not less than 1.5 ml. of 0.1N Na2S2O3.  Per-salts which may be used are the alkali-metal percarbonates, perpyrophosphates, persilicates and particularly perborates.  Suitable esters are those which do not yield easily oxidizable hydrolysis products, such as polyhydric phenols, unsubstituted lower aliphatic aldehydes, and a - and b -diketones; examples are (a) esters of phenols and substituted phenols, (b) esters of monohydric aliphatic alcohols containing electrophilic substituents, (c) esters of polyhydric aliphatic alcohols containing several ester groups on adjacent carbon atoms, (d) esters of mono- and di-saccharides containing preferably 3 or more ester groups on adjacent carbon atoms, (e) esters containing 2 ester groups attached to the same carbon atom, (f) esters of the enolic forms of ketones, and (g) esters of N-substituted derivatives of hydroxylamine.  Many esters are specified; representative members of each class are (a) phenyl benzoate, (b) trichloroethyl acetate, (c) sorbitol hexa-acetate, (d) glucose tetra- or penta-acetate, (e) benzaldehyde diacetate, (f) isopropenyl acetate, and (g) acetyl acetohydroxamic acid.  A particularly favoured ester belonging to class (a) is the benzoyl ester of commercial (sodium or potassium) phenol sulphonate. The ester should be present in an amount such that there is either 0.25-2 molecules of ester per atom of available oxygen, or 2-15 parts of ester to each part of hydrogen peroxide (100%) by weight. A preferred composition is one which contains 2-30% of ester and 1-15% of per-salt.  One or more alkaline substances such as alkali metal carbonates, phosphates (including polyphosphates) and silicates are preferably also added so that the composition before the addition of the ester would have a pH of 9-11.  The compositions for use in the process may also include alkali metal chlorides or sulphates, carboxymethyl cellulose or fluorescent agents.ALSO:A bleaching process comprises the use of an aqueous solution containing hydrogen peroxide, which may either be added to the solution as a liquid, or produced in situ by liberation from a per-salt, and a carboxylic ester having a titre, in a test which is described in detail, of not less than 1.5 ml. of 0.1NNa2S2O3.  Per-salts which may be used are the alkali-metal percarbonates, perpyrophosphates, persilicates, and particularly perborates.  Suitable esters are those which do not yield easily oxidizable hydrolysis products, such as polyhydric phenols, unsubstituted lower aliphatic aldehydes, and a - and b -diketones; examples are (a) esters of phenols and substituted phenols, (b) esters of monohydric aliphatic alcohols containing electrophilic substituents, (c) esters of polyhydric aliphatic alcohols containing several ester groups on adjacent carbon atoms, (d) esters of mono- and di-saccharides containing preferably 3 or more ester groups on adjacent carbon atoms, (e) esters containing 2 ester groups attached to the same carbon atom, (f) esters of the enolic forms of ketones, and (g) esters of N-substituted derivatives of hydroxylamine.  Many esters are specified; representative members of each class are: (a) phenyl benzoate, (b) trichloroethyl acetate, (c) sorbitol hexa-acetate, (d) glucose tetra- or penta-acetate, (e) benzaldehyde diacetate, (f) isopropenyl acetate, and (g) acetyl acetohydroxamic acid.  A particularly favoured ester belonging to class (a) is the benzoyl ester of commercial (sodium or potassium) phenol sulphonate.  The ester should be present in an amount such that there is either 0.25-2 molecules of ester per atom of available oxygen, or 2-15 parts of ester to each part of hydrogen peroxide (100%) by weight. A preferred composition is one which contains 2-30% of ester and 1-15% of per-salt.  One or more alkaline substances such as alkali metal carbonates, phosphates (including polyphosphates) and silicates are preferably also added so that the composition before the addition of the ester would have a pH of 9-11.  The compositions for use in the process may also include soap, a synthetic detergent such as an alkyl sulphate, alkylaryl sulphonate or isethionate, alkali metal chlorides or sulphates, carboxymethyl cellulose or fluorescent agents.