Isp Investments Inc.

Hemant Parikh

Terry E Smith

Yuanzhen Zhong

Kou-Chang Liu

Paul D Taylor

Lowell R Anderson

A process is described for increasing the viscosity and high humidity curl retention of aqueous solutions of homogeneous copolymers of 20-99% vinyl pyrrolidone (VP) and 1-80% N-3,3-dimethylamino-propyl methacrylamide (DMAPMA). The high viscosity solutions are particularly useful as the active component of hair care products.

Process for increasing the viscosity of aqueous solutions of homogeneous

A process for making homogeneous copolymers of vinylpyrrolidone (VP) and vinyl acetate (VA) which form clear aqueous solutions and have high cloud points. The process involves precharging VP and VA monomers in a predetermined ratio, and then feeding VP and VA at a predetermined rate, the ratio of the components in the initial charge and the feeding rates for the monomer being selected in accordance with the reactivity rates of the monomers towards copolymerization as opposed to homopolymerization.

Process for providing homogeneous copolymers of vinylpyrrolidone and

This invention relates to an improved process for producing a clear solution of vinylpyrrolidone (VP) and vinyl acetate (VA) monomers which comprises, in an anhydrous system, (a) reacting a C.sub.2 to C.sub.3 alcoholic solution containing said VA monomer and between about 60 and about 80 wt. % portion of total VP monomer in the presence of between about 0.05 and about 0.3 wt. % of a free radical initiator selected from the group consisting of tertamylperoxy pivalate and 2,2-azobis(2-methylbutyronitrile) or a mixture thereof for a period of from about 5 to about 10 hours, at a temperature between about 60.degree. and about 110.degree. C.; (b) gradually adding the remaining VP monomer in C.sub.2 to C.sub.3 alcohol solution at reaction temperature after the addition of the VA monomer is complete; (c) raising the temperature of the resulting reaction mixture to between about 110.degree. and about 150.degree. C.; (d) continuing the polymerization reaction at said higher temperature in the presence of from about 0.11 to about 0.6 wt. %, based on total monomers, of 2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane and (e) cooling the resulting reaction mixture and recovering a homogeneous VP/VA copolymer C.sub.2 to C.sub.3 alcohol solution containing less than 100 ppm of residual vinylpyrrolidone monomer or vinyl acetate residual monomer.

Growing community of inventors

Harriman, NY, United States of America

Hemant Parikh