Abstract: A process for the preparation of polycarbonate resins having a low yellowness index is described. The process involves converting phosgene with a sodium bisphenolate solution by means of a phase interface process performed with the exclusion of oxygen. The sodium bisphenolate solution used in the process has a dissolved oxygen content of <150 ppb. Also described are optical data storage media prepared from the polycarbonate of the present invention.

Abstract: A process for producing bis(4-hydroxyaryl)alkane is disclosed. The process comprise in sequence the steps of (a) passing inert gas through a melt at 150 to 230° C. that contains bis(4-hydroxyaryl)alkane and other aromatic hydroxy compounds, under conditions designed to remove said other aromatic hydroxy compounds from said melt and to obtain a stream of inert gas that contains said other aromatic hydroxy compounds (b) condensing the stream obtained in (a) to remove said other aromatic hydroxy compound, and to obtain a stream of inert gas, and (c) purifying and compressing the stream of inert gas obtained in (b), and recycling to step (a).

Abstract: A process for producing bis(4-hydroxyaryl)alkane is disclosed. The process comprise in sequence the steps of (a) passing inert gas through a melt at 150 to 230° C. that contains bis(4-hydroxyaryl)alkane and other aromatic hydroxy compounds, under conditions designed to remove said other aromatic hydroxy compounds from said melt and to obtain a stream of inert gas that contains said other aromatic hydroxy compounds (b) condensing the stream obtained in (a) to remove said other aromatic hydroxy compound, and to obtain a stream of inert gas, and (c) purifying and compressing the stream of inert gas obtained in (b), and recycling to step (a).

Abstract: The present invention relates to a method for avoiding undesirable discoloration in polycarbonate production by catalytic removal of dissolved oxygen from phenol by

Abstract: The present invention relates to a process for producing bis(4-hydroxy-aryl)alkanes of high purity from addition products of bis(4-hydroxy-aryl)alkanes and aromatic hydroxy compounds which are obtained by the acid-catalysed reaction of the aromatic hydroxy compounds with ketones.

Abstract: The present invention relates to a process for the production of bis-(4-hydroxyaryl)-alkanes by a heterogeneously catalyzed reaction of aromatic hydroxy compounds with ketones in at least two reactors connected in series, which, as the reaction progresses, are operated at higher temperatures, wherein the total quantity of ketone is divided between the individual reactors in such a manner that the higher is the temperature of the particular reactor, the smaller is the proportion per reactor, the highest possible reactor loading is maintained and the temperatures and temperature gradients are kept as low as possible.

Abstract: A catalyst for the preparation of bisphenols from phenols and compounds containing carbonyl groups consisting of a styrene/divinyl benzene copolymer into which are introduced sulphochloride groups which, in turn, have been partly reacted with mercaptoalkylamine and partly hydrolyzed to form sulphonic acid groups.

Abstract: Polymer blends consisting of from 60-99 % by weight of polyamide and of from 1-40 % by weight of a graft product of polyethylene or copolymers of ethylene with grafted units of (meth)acrylic acid and/or (meth)acrylic acid derivatives and/or maleic acid which graft products have been prepared by a special grafting process.

Abstract: High impact resistant polymer blends comprising 70-99% by weight of a polyamide and 1-30% by weight of a polyethylene having been oxidized by a special process.