Patent GB-963135-A (GB)
Title: Stabilisation of esters in bleaching compositions
Inventor: ALSBURY ALLAN
IPC: D06L3/02
Filed: 1960-12-19
Abstract: A detergent composition comprises a per salt, e.g. an alkali metal perborate, percarbonate, perpyrophosphate or persilicate, and an ester of the general formula CH3CO.O.R.SO3M in which R is an unsubstituted or substituted phenylene radical and M is an alkali metal, ammonium or substituted ammonium radical stabilized by a material having a pH of 2.5-8 measured in a 1% by weight aqueous solution and capable of reacting as an acid with a substance which has a pH measured in a 1% by weight aqueous solution of at least 9.5. The detergent may be sodium dodecylbenzene sulphonate.  Suitable stabilizing compounds are the di- and tri-alkali metal salts of ethylene diaminetetra acetic acid, the monoalkali metal dihydrogen ortho phosphates and the di-alkali metal dihydrogen pyrophosphates. 1-100% by weight of the stabilizing compounds based on the weight of the esters is preferably used.  The ester and the stabilizing compound may be admixed by granulation by the addition of a volatile liquid, e.g. water, to a mixture of the ester and stabilizing compound and mechanical working, the liquid being subsequently driven off by heating, by mechanically working the mixed ester and stabilizing compound with the monoethanol amides of fatty acids or with other neutral or non-reactive substances or by spray drying an aqueous solution or slurry of the ester and stabilizing compound, neutral salts, e.g. sodium sulphate, being included in the granules if desired.  The composition may also contain water-soluble condensed phosphates, carbonates, silicates and sodium carboxymethyl cellulose. The Provisional Specification also refers to the stabilization in detergent compositions of the esters defined in Specification 836,988 with boric acid or phenol.ALSO:A bleaching composition comprises a per salt, e.g. an alkali metal perborate, percarbonate, perpyrophosphate or persilicate, and an ester of the general formula CH3CO.O.R.SO3M in which R is an unsubstituted or substituted phenylene radical and M is an alkali metal, ammonium or substituted ammonium radical stabilised by a material having a pH of 2.5-8 measured in a 1% by weight aqueous solution and capable of reacting as an acid with a substance which has a pH measured in a 1% by weight aqueous solution of at least 9.5.  Suitable stabilizing compounds are the di- and tri-alkali metal salts of ethylene diaminetetra-acetic acid, the monoalkali metal dihydrogen ortho phosphates and the di-alkali metal dihydrogen pyrophosphates.  1-100% by weight of the stabilizing compounds based on the weight of the esters is preferably used.  The ester and the stabilizing compound may be admixed by granulation by the addition of a volatile liquid, e.g. water, to a mixture of the ester and stabilizing compound and mechanical working, the liquid being subsequently driven off by heating, by mechanically working the mixed ester and stabilizing compound with the monoethanol amides of fatty acids or with other neutral or non-reactive substances or by spray drying an aqueous solution or slurry of the ester and stabilizing compound, neutral salts, e.g. sodium sulphate, being included in the granules if desired.  The composition may also contain detergents, e.g. sodium dodecyl benzene sulphonate, water soluble condensed phosphates, carbonates, silicates and sodium carboxymethyl cellulose.  The Provisional Specification also refers to the stabilisation in bleaching compositions of the esters defined in Specification 836,988 with boric acid or phenol.