The Dow Chemical Company

Frederick Bernhard Kassell

Thoi H Ho

James R Gross

James L Potter

Che I Kao

Jose L Aguilar

High molecular weight polyhalobisphenol polycarbonates are produced by adding phosgene to a polyhalobisphenol in the alkali metal phenate form whereby the chloroformates of the bisphenol are formed and then adding an activated pyridine such as 4-aminopyridines or 2-substituted pyridines to generate a high molecular weight polycarbonate having an inherent viscosity in the range from about 0.4 to about 0.9.

Two stage catalytic production of high molecular weight

A method for the preparation of aqueous solutions of anionic polyelectrolytes by combining a stream of a high solid content alkenoic acid-alkyl acrylate latex with a stream of aqueous alkali metal hydroxide, mixing the combined streams under low shear conditions and heating the mixture to produce a polyelectrolyte solution. The use of these steps avoids the formation of high viscosity mixtures or rubber masses which are difficult, if not impossible, to further process into the desired polyelectrolyte solution.

Growing community of inventors

Lake Jackson, TX, United States of America

Frederick Bernhard Kassell