SURFACE TREATING COMPOSITIONS
1389673 Detergent and textile softening composition PROCTER & GAMBLE Ltd 20 Dec 1972 [10 Jan 1972 26 April 1972] 1054/72 and 19353/72 Heading C5D [Also in Division D1] A detergent composition comprises a substituted ammonio amidate having the formula (a) R 1 CON<SP>1</SP>N<SP>+</SP>R 2 R 3 R 4 or a cationic adduct thereof having the formula (b) wherein X is an anion, R 1 is an aliphatic, araliphatic or aromatic group (1 to 25C), R 2 and R 3 each represents methyl, ethyl, hydroxymethyl, hydroxyethyl or cyanoethyl and R 4 is either an alkyl group (1 to 25C), or a hydroxymethyl or a hydroxethyl group or is a group of formula (c) -CHR 5 -C(OH)R 6 R 7 , wherein R 5 and R 6 each represents H or an alkyl group (1 to 4C), and R 7 is H or a group R 1 as defined above, provided that at least one of R 1 and R 4 contains an alkyl group with at least 8 carbon atoms, together with one or more pH buffers such that a 0À1% by weight aqueous solution of the ammonio amidate containing the buffer(s) either (i) has a pH less than, equal to or not more than 2 units above the pKa value (as defined below) of the ammonio amidate, or (ii), the a pH more than 2 units above this pKa value but not exceeding 11, provided that in case (ii), if the group R 4 is a methyl, ethyl, hydroxymethyl or hydroxyethyl group, there is also present an anionic surface active agent in an amount greater by weight than the ammonio amidate. The pKa value is defined as the pH at which the compounds are present 50 molar per cent in Zwitterionic form and 50 molar per cent in cationic form. Thus the ammonio amidates are cationic (and substantive to surfaces) under neutral or weakly acid conditions, and are Zwitterionic (and non-substantive to surfaces) under weakly alkaline conditions. The compositions may be used for cleaning fibres, fabrics and hair, and also hard surfaces such as ceramics, glass, metals and paint. In their Zwitterionic form, the compounds confer soil repellant and soil release properties on surfaces. In their cationic form, they additionally provide antistatic properties. Preferred ammonio amidates have the formula C 15 H 31 CON<SP>-</SP>N<SP>+</SP>(CH 3 ) 3 ; The ammonio amidate preferably has a pKa in the range from 3 to 7, preferably 5 to 7. The compositions may be intended for use in an aqueous liquor (such as an afterwash rinse) having a pH within two units, preferably one unit above or below the pKa value of the ammonio amidate, such that the ammonio amidate will be present to a considerable extent in its cationic form. The anion of the cationic adduct may be that of the buffering agent. Suitable buffering agents include phosphates, polyphosphates, borates, citrates and mixtures of these. Alternatively the ammonio amidates may be incorporated in washing compositions buffered preferably in the range of pH 9 to 11 and containing a synthetic anionic detergent such as an alkyl benzene sulphonate, alkyl sulphate, or alkylether sulphate, preferably in the ratio of amidate : anionic detergent of from 20 : 1 to 1 : 4, the amidate being predominantly present in its Zwitterionic form and taking part in the washing action of the detergent composition. Suitable buffering agents include detergency builder salts such as water-soluble phosphates, polyphosphates, silicates, carbonates, borates and organic alkaline sequestrants such as nitrilotriacetates or polycarboxylates such as gluconates and polyitaconates or aminopolycarboxylates, usually present as the sodium salts. Such detergent compositions may further contain non-ionic and Zwitterionic surface active agents. Specified non-ionics include polyethylene oxide condensates on long chain fatty acids, fatty alcohols, amines and alkylphenols; polyethylene imine condensates on fatty acids, amines or amides, polyethoxypolypropoxy condensates, and polyethoxy sorbitan esters. Specified Zwitterionics include long chain alkyl or alkylbenzyl betaines or sulpho-betaines. The amidate may be present in treatment solutions at a level such as to provide from 0À01 to 5%, preferably 0À1% of the cationic form based on the dry weight of fabric. With conventional liquor to cloth ratios this may correspond to a concentration of from 0À001 to 0À5% preferably from 0À1 to 0À3% by weight of the solution. The examples relate to the treatment of cotton terry towels and swatches of human hair with buffered ammonio amidate compositions either as afterwash rinses or as components of detergent compositions during washing cycles. The exemplified buffer is a mixture of sodium citrate and citric acid or citric acid alone.