Materials and methods for reshaping of essentially rigid keratinaceous

Abstract

In the disclosed method for the reshaping (adornment, repair, covering, prosthetic extension, etc.) of essentially rigid, keratinaceous surfaces such as nail plates with a free radical-polymerizable acrylic ester, the free radical initiator comprises a compound of the formula III ##STR1## wherein R.sup.1 through R.sup.4 are hydrogen, an aliphatic group, an aromatic group, a cycloaliphatic group, or, less preferably, a sulfhydryl group, an alkali or alkaline earth metal salt of a sulfhydryl group, a halogen, or amino group; or R.sup.3 or R.sup.4 can be an alkali metal or alkaline earth metal cation when the 5-carbon is negatively charged. The compound of formula III, in chemically-curable systems is utilized in combination with a metal salt cocatalyst and, optionally, an organic buffering compound and a crosslinker. In light-curable systems, the compound of formula III has some photosensitizing properties but is preferably used in combination with a second photosensitizer which is effective when irradiated with light having a wavelength of at least about 400 nm. These curable compositions are preferably free of organic peroxides, aromatic amines, and inorganic fillers and pigments.