Development of Water-Based Nail Enamel

The development of the water-based nail enamel has been a dream of cosmetic scientists for a long time, because of many improvable points. The most difficult point is to obtain good wearability of the applied film. When polymer emulsions are used as a film forming material, the wearability depends mostly on the polymer's chemical compositions and its film's physicochemical properties. According to our studies on various factors, we found out that the incomplete coalescence between the polymer particles was one of the main cause of poor wearability. To get a completely coalesced film, and at the same time satisfy the basic properties generally required for nail enamels such as fast dryability at room temperature and sufficient film strength etc., we investigated numerous types of polymers. And finally, we could successfully develop a novel polymer emulsion including a coalescence accelerating compound inside the polymer particles. The film formed from this polymer emulsion showed complete coalescence between the polymer particles and good wearability on the nail. We named this a coalescence accelerating polymer emulsion. In this paper, we'd like to report about its properties, the unique coalescing mechanism and some interesting characteristics of the water-based nail enamel prepared from this polymer emulsion.