WATER-BASED NAIL POLISH 109 aqueous systems without significantly increasing the tendency to foam. As previously mentioned, drying difficulties at low temperatures and/or high relative humidities is an inherent problem. It is therefore far less easy to control the drying rate for a water-based system than for a solvent-borne one where there is a large choice of volatile solvents. Nevertheless, cosolvents such as propylene glycol and volatile silicones can be used to provide some control over evaporation rate and film-formation temperature. It is clear from the foregoing discussion that the formulation of aqueous nail polish is generally more complex than is the case for solvent systems. This very complexity, i.e., the need for more formulation additives, can itself be regarded as a disadvantage. Additives introduced to achieve one effect can be damaging in other respects (e.g., wetting versus foaming). Developments that allow formulation simplification, such as low-foaming dispersions and latexes with good wetting ability and film-forming char- acteristics, would be beneficial. REFERENCES (1) J. M. Friel, E•opean patent 0,466,409 (1992). (2) C. A. Finch, Chemistry and Technology q[ Water Solule Polymers, (Plenum Press, New York, 1983). (3) J. C. Padget, in Additives for Water Soluble Coatings, D. R. Karsa, Ed. (Royal Society of Chemistry, 1988), Special publ. 76, p. 1. (4) K. Kendall and J. C. Padget, J. Adhesion and Adhesives, 7, 142, (1982). (5) J. E. Glass, Ed., The Inj7•ence of A•sociative Thickeners and Rheology on Coatings Performance, (North Dakota State University, Fargo, 1983). (6) P. W. Dillon, J. Coatings Technol., 49(634), 38, (1977). (7) A. L. Rocklin, J. Coatings Technol., 58(732), 61, (1986). (8) G. D. Parfitt, Dispersions of Powders in Liquids, (Applied Science Publishers, 1981).

j. Cosmet. Sci., 50, 111-131 (March/April 1999) Preprints of the 1999 Annual Scientific Seminar (Thursday Program) May 6-7, 1999 Chicago Hilton & Towers Chicago, IL 111