This invention relates to polymerized cosmetic coatings for human nails and particularly to improved removability thereof.
Radiation curable cosmetic coatings for human nails are typically applied in professional nail salons wherein nail technicians apply a gel coating to fingernails or toenails and expose the coating to ultraviolet light radiation to cure the coating, resulting in a far more durable coating than can be achieved with solvent based nail polishes. While solvent-based nail polishes are easily removed with solvent such as acetone, polymerized cosmetic coatings are designed to be very durable and often are not easily removable in comparison to air dryed nail varnishes. Various solutions to the problem of removability of polymerized cosmetic coatings for human nails have been proposed, for example Rosenberg in U.S. Pat. No. 3,928,113 proposed applying a basecoat comprising a water-soluble or water-swellable polymer in a solvent system followed by application and then curing of a photocurable nail lacquer composition. Thong, et al., U.S. Pat. Publ. 2011/0182838, disclosed polymerized cosmetic coatings for natural and artificial nails having improved removability with solvents comprising a reactive (meth)acrylate, a reactive urethane (meth)acrylate, a reactive polypropylene glycol monomethacrylate, a polymethylmethacrylate-polymethacrylic acid copolymer, a pyromellitic dianhydride glyceryl dimethacrylate, a non-reactive solvent-dissolvable polymer, a non-reactive solvent which cures under radiation to an acrylic thermoset having voids which contain a solvent-dissolvable polymer. There are problems with the Rosenberg, Thong, et al., and other prior art approaches to this problem which the present invention solves. Rosenberg, for example, fails due to high water sensitivity since the base coat is not resistant to water and causes lifting of the entire coating system when exposed to water. Neither reference discloses acids or bases in the solvent system used for removal.