The fading of coloured fabrics by sunlight during wear and during drying is a major problem for consumers in many parts of the world, thus susceptible fabrics in temperate and high latitude regions in addition to those in the tropics can be severely faded. Sun fading of fabrics is of specific concern to consumers because the contrast between exposed and unexposed areas makes it particularly noticeable. e.g on collars, inside versus outside of garments, and on wrap around garments such as saris. The textile industry has made extensive efforts to develop light stable dyes and after treatments to protect the dyes, however the fading of fabric still remains a problem.
The use of certain sunscreens has already been discussed in the literature. U.S. Pat. No. 4,788,054 (Bernhardt) teaches the use of N-phenylphthalisomides as ultraviolet radiation absorbers for cotton, wool, polyester and rayon. The compositions require an aqueous sulphuric acid vehicle for deposition. Fabric care compositions comprising a water dispersible/water soluble copolymers which prevent photofading are disclosed in EP 0 523 956 (Unilever).
GB 1 387 520 (L'Oreal) discloses formulations that contain derivative of benzylidene-camphor in cosmetic formulations.
However the major problem that needs to be overcome is how to deposit photofading inhibitors onto fabric during the wash using a detergent containing washing system, which is designed to suspend particulate materials and solubilise oils. This problem is particularly exacerbated by the presence of anionic surfactant.
The present invention relates to compositions in which selected photofading inhibitors deposit easily onto fabric during the wash process.
USPTO Backgrounds
USPTO Backgrounds