Ester perhydrolysis by preconcentration of ingredients

A bleaching composition comprising:

• (i) a peroxygen compound capable of generating perhydroxyl anion in an aqueous solution;
• and
• (ii) an organic carbonate bleach precursor having a leaving group whose conjugate asset has a pKa of greater than 13 and a structure which is:
• ##STR5## wherein:
• ##STR6## R.sub.1, R.sub.2 and R.sub.3 are each a radical selected from the group consisting of alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, alkaryl, aryl, phenyl, hydroxyalkyl, polyoxyalkylene, and R.sub.4 (O).sub.m C(O).sub.n R.sub.1 ;
• R.sub.4 is selected from a bridging group consisting of alkylene, cycloalkylene, alkylenephenylene, phenylene, arylene, and polyalkoxylene, and wherein the bridging group can be unsubstituted or substituted with C.sub.1 -C.sub.20 atoms selected from the group consisting of alkyl, alkenyl, benzyl, phenyl and aryl radicals;
• Z.sup.- is a monovalent or multivalent anion leading to charge neutrality when combined with Q.sup.+ in the appropriate ratio and wherein Z.sup.+ is sufficiently oxidatively stable not to interfere significantly with bleaching by a peroxy carbonic acid;
• Q is nitrogen;
• m and n are 1;
• and
• B is A or an alkyl radical;
• and
• the peroxygen compound and precursor being present in a relative molar ratio of greater than about 1:1.