General Electric Company

Darlene Hope Nance

Gaylord M Kissinger

Sheldon J Shafer

Edward Brittain Stokes

Emil Markov Georgiev

Eduard Hendricus Schlarmann

Alexey Kruglov

Karl Aaron Baro

James C Blubaugh

Chuks O Mbeledogu

Rudy Francois Alain Joseph Peemans

Fang Christine Chen

Jose M Quintana

A method for regenerating deactivated sulfonated cation exchange catalysts comprises washing the deactivated catalyst with phenol-water mixtures comprising about 5-20 wt. % of water in phenol at a temperature of about 70-95&deg; C.

Regeneration of catalysts used in the manufacture of bisphenols

Low-particulate dihydric aromatic compounds such as bisphenol-A that can be used in the synthesis of low-particulate polycarbonates are prepared by introducing into a desorber column containing a non-aggregate packing material an adduct of bisphenol and phenol and optionally a stripping gas. The column is maintained at an operating temperature that is sufficiently high and an operating pressure that is sufficiently low such that the adduct is distilled. The stream of phenol and the stripping gas is recovered from the top of the column. A second stream containing bisphenol that is substantially free of added particulate matter is recovered from the bottom of the column. This purified stream of bisphenol-A can further be used in a method of producing optical-grade polycarbonate.

Production of low-particulate bisphenol and use thereof in the manufacturing of polycarbonate

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Mount Vernon, IN, United States of America

Darlene Hope Nance