| abstract |
The laundry detergent bars of the present invention comprise detergent surfactant, detergency builder, an effective amount of a dye transfer inhibitor, and an effective amount of an optical brightener to improve the whitening and dye transfer inhibition of the clothes washed by the bars. Preferably, the bars comprise from about 10 % to about 60 % by weight anionic surfactant, from about 5 % to about 60 % by weight detergent builder, from about 0.10 % to about 2.0 % of a dye transfer inhibitor, and from about 0.05 % to about 1.0 % of an optical brightener. Non-limiting examples of dye transfer inhibitors include polyvinylpyrridine N-oxide, polyvinylpyrrolidone (PVP), PVP-polyvinylimidazole copolymer, and mixtures thereof. Copolymers of N-vinylpyrrolidone and N-vinylimidazole polymers (PVPI) are also preferred for use herein. Preferred optical brighteners are diamino stilbene, distyrilbiphenyl-type optical brighteners, and mixtures thereof. |