Bleaching solutions and method utilizing selected bleach activators effective at low perhydroxyl concentrations
AssigneeThe Procter & Gamble Company
InventorsKevin L. Kott, Alan D. Willey, Gregory S. Miracle, James C. T. R. Burckett-St. Laurent
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Abstract
Improved aqueous bleaching solutions formed by reacting a bleach activator having a perhydrolysis selectivity coefficient of 5 or greater and a low-pH perhydrolysis-efficiency coefficient of 0.15 or higher are provided. More specifically, the invention relates to bleaching solutions which provide enhanced cleaning/bleaching benefits though the selection of bleach activators at mildly alkaline washing solutions or in the presence of reduced-levels of hydrogen peroxide.
Claims28
A bleaching solution comprising:
- (a) an effective amount of a bleach activator having the formula RC(O)--L which produces a peracid RC(O)--OOH on perhydrolysis;
- wherein R is selected such that the difference in aqueous pK.sub.a between acetic acid and the carboxylic ring analog, RC(O)OH, of said peracid is at least 0.6 and L is a leaving group;
- said bleach activator having a perhydrolysis selectivity coefficient, Kp/K.sub.D of at least about 5 and a low-pH perhydrolysis-efficiency coefficient of at least about 0.15;
- and
- (b) an effective amount of an oxygen bleach source;
- said bleaching solution having low soil resistivity.
A method for forming a bleaching solution comprising the step of reacting under aqueous conditions, effective amounts of
- (a) a bleach activator having the formula RC(O)--L which produces a peracid RC(O)--OOH on perhydrolysis;
- wherein R is selected such that the difference in aqueous PKa between acetic acid and the carboxylic ring analog, RC(O)OH, of said peracid is at least 0.6 and L is a leaving group;
- said bleach activator having a perhydrolysis selectivity coefficient, Kp/K.sub.D of at least about 5 and a low-pH perhydrolysis-efficiency coefficient of at least-about 0.15 ;
- and
- (b) an effective amount of an oxygen bleach source.
Dependencies are inferred from the claim text.