Process for preparing bisphenol a (BPA) in the presence of at least two impurities
AssigneeCovestro Deutschland AG
InventorsJerico Jayson Uy, Erik Sluyts
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Abstract
The present invention relates to a process for preparing bisphenol A in the presence of at least two impurities being selected from the group consisting of 2-methylbenzofurane, hydroxyacetone, alpha-methylstyrene, acetophenone, benzene and/or cumene without poisoning the catalyst system comprising an ion exchange resin catalyst and a sulfur containing cocatalyst, wherein at least part of the sulfur containing cocatalyst is not chemically bound to the ion exchange resin catalyst. Moreover, the present invention provides a process for preparing polycarbonate.
Claims17
A process for preparing ortho,para-, ortho, ortho- and/or para,para-bisphenol A comprising the step of
- (a) condensing raw phenol and raw acetone in the presence of a catalyst system, wherein the catalyst system comprises an ion exchange resin catalyst and a sulfur containing cocatalyst, wherein at least part of the sulfur containing cocatalyst is neither covalently nor ionically bound to the ion exchange resin catalyst at the beginning of process step (a),
- wherein at least two of the following (A) to (F) are true:
- (A) the amount of 2-methyl benzofuran present in step (a) is higher than 1 ppm with respect to the total weight of the raw phenol;
- (B) the amount of hydroxyacetone present in step (a) is higher than 1 ppm with respect to the total weight of the sum of the weights of the raw phenol and the raw acetone;
- (C) the amount of alpha-methylstyrene present in step (a) is higher than 1 ppm with respect to the total weight of the raw phenol;
- (D) the amount of acetophenone present in step (a) is higher than 1 ppm with respect to the total weight of the raw phenol;
- (E) the amount of benzene present in step (a) is higher than 1 ppm with respect to the total weight of the raw acetone;
- (F) the amount of cumene present in step (a) is higher than 1 ppm with respect to the total weight of the raw acetone.
Dependencies are inferred from the claim text.