Patent ID: 6255421
Filing Date: 2001-07-03
Classification: A61K,A61Q,C08F

Abstract:
A non-aqueous, heterogeneous polymerization process which provides a cosmetically or pharmaceutically-acceptable polymer swollen with an oil composition which comprises: polymerizing, by weight, about 5-70% of a vinyl lactam monomer wherein the vinyl monomer is a N-vinyllactam selected from N-vinyl-pyrrolidone and N-vinylcaprolactam, optionally with a comonomer selected from vinyl acetate, acrylic acid, methacrylic acid, acrylamide, methacrylamide, an alkyl (meth)acrylate, an alkyl (meth)acrylamide, a hydroxyalkyl (meth)acrylate and a hydroxyalkyl (meth)acrylamide; and a N,N-dialkylamino-alkyl (meth)acrylate and a N,N-dialkylaminoalkyl methacrylamide wherein alkyl is independently a C.sub.1 to C.sub.4 alkyl group, and N-quaternary derivatives thereof; and mixtures thereof, in about 30-95% of an oil as solvent, wherein said oil is selected from the group consisting of a silicone oil, a mineral oil and a water-insoluble organic ester and a free radical initiator, optionally in the presence of a crosslinking agent and/or an oil-soluble surfactant, with agitation, under an inert gas, at about 40-150.degree. C., wherein said amount of the oil is sufficient to keep the resultant vinyl lactam polymer in a stirrable state until the end of the polymerization and wherein the vinyl monomer and optional crosslinking agent are fed into the reactor charged with said oil and free radical initiator continuously over a period of about 3-6 hours at a rate such that substantially no free monomer is present during the polymerization.