Abstract: A process for the storage or transportation of pretreated, conditioned ion exchangers as catalysts for chemical reactions is disclosed. The preconditioned ion-exchange resin is kept as preconditioned ion-exchange resin suspension in a storage or transporting container. The container with the preconditioned ion-exchange resin suspension is transported to either a storage site for storage or to a reactor for transfer of the resin to the reactor.

Abstract: In a device and a process for continuous solid/liquid separation (filtration) of solid-liquid suspensions on moving filters, for example on rotating drum filters or belt filters, the active filtering layer contains a woven fabric material composed of synthetic fibres, which has an enhanced filtrate permeability and also an enhanced thermal stability with improved dimensional stability, and also improved mechanical strength compared with polypropylene fibres.

Abstract: The present invention relates to a process for the avoidance of solids deposits in droplet separators (demisters) by metering in suitable liquids, in particular in the production of bis(4-hydroxyaryl)alkanes.

Abstract: A process for the storage or transportation of pretreated, conditioned ion exchangers as catalysts for chemical reactions is disclosed. The preconditioned ion-exchange resin is kept as preconditioned ion-exchange resin suspension in a storage or transporting container. The container with the preconditioned ion-exchange resin suspension is transported to either a storage site for storage or to a reactor for transfer of the resin to the reactor.

Abstract: A process for the preparation of high purity bisphenol A is disclosed. The multi-step process entails a process whereby bisphenol A of a purity of preferably at least 99.8% can be obtained.

Abstract: A process for the preparation of high purity bisphenol A is disclosed. The multi-step process entails a process whereby bisphenol A of a purity of preferably at least 99.8% can be obtained.

Abstract: A process for the preparation of high purity bisphenol A is disclosed. The multi-step process entails a process whereby bisphenol A of a purity of preferably at least 99.8% can be obtained.

Abstract: A process for the production of bisphenol-A having low concentration of sulphur is disclosed. The process comprise a) reacting phenol with acetone in the presence of a sulfonic acid ion exchanger to form a product mixture containing water, bisphenol-A/phenol adduct, phenol and sulfurous particles, and b) filtering the product mixture to separate the sulfurous particles to obtain a purified product mixture that contains water, phenol and bisphenol-A/phenol adduct. In one embodiment of the process further comprise distilling the purified product mixture to remove the water to obtain a first material system that contains said adduct and phenol, crystallizing the adduct, and removing the phenol by filtration using a filtering apparatus to obtain crystalline adduct.

Abstract: A process for producing bisphenol A is disclosed. The process entails a) reacting phenol with acetone in the presence of an acidic catalyst to form a reaction mixture that includes bisphenol A and water, and b) removing water from the reaction mixture by distillation in a column to obtain a bottom product, and c) separating bisphenol-A/phenol adduct from the reaction mixture by crystallization and filtration. The bottom temperature of the column is 100 to 150° C., the overhead temperature of the column is 20 to 80° C., the absolute pressure is 50 to 300 mbar at the head of the column and 100 to 300 mbar at the bottom of the column, and wherein said (c) is carried out before or after said (b).

Abstract: A process for the preparation of polycarbonate by the phase interface process is disclosed. The process includes (a) preparing a sodium hydroxide solution by chloralkali electrolysis, the solution containing not more than 30 ppm sodium chlorate relative to the weight of sodium hydroxide, and (b) reacting an aqueous solution of said sodium hydroxide with at least one dihydoxydiarylalkane to obtain a solution of disodium salt and (c) reacting said solution of disodium salt with phosgene in the presence of at least one organic solvent, a chain terminator and optionally a branching agent to obtain an oligocarbonate, and (d) condensing the oligocarbonate in the presence of at least one catalyst to obtain a material system containing polycarbonate and organic solvent and (e) separating off of the organic phase from said material system. The polycarbonate prepared by the inventive process is characterized by its low yellowness index.

Abstract: A process for extracting phenol from a phenol-containing aqueous solution is disclosed. The process entails contacting the aqueous solution with an extracting agent that comprise a mixture of 60 to 99% of methyl isobutyl ketone, 1 to 40% of anisole and 0 to 20% of mesitylene.

Abstract: A process for extracting phenol from a phenol-containing aqueous solution is disclosed. The process entails contacting the aqueous solution with an extracting agent that comprise a mixture of 60 to 99% of methyl isobutyl ketone, 1 to 40% of anisole and 0 to 20% of mesitylene.

Abstract: A process for the production of bisphenol-A having low concentration of sulphur is disclosed. The process comprise a) reacting phenol with acetone in the presence of a sulfonic acid ion exchanger to form a product mixture containing water, bisphenol-A/phenol adduct, phenol and sulfurous particles, and b) filtering the product mixture to separate the sulfurous particles to obtain a purified product mixture that contains water, phenol and bisphenol-A/phenol adduct. In one embodiment of the process further comprise distilling the purified product mixture to remove the water to obtain a first material system that contains said adduct and phenol, crystallizing the adduct, and removing the phenol by filtration using a filtering apparatus to obtain crystalline adduct.

Abstract: A process for producing bisphenol A is disclosed. The process entails a) reacting phenol with acetone in the presence of an acidic catalyst to form a reaction mixture that includes bisphenol A and water, and b) removing water from the reaction mixture by distillation in a column to obtain a bottom product, and c) separating bisphenol-A/phenol adduct from the reaction mixture by crystallization and filtration. The bottom temperature of the column is 100 to 150° C., the overhead temperature of the column is 20 to 80° C., the absolute pressure is 50 to 300 mbar at the head of the column and 100 to 300 mbar at the bottom of the column, and wherein said (c) is carried out before or after said (b).

Abstract: The present invention relates to a process for preparing bisphenol A in which the phenol and acetone are reacted to give bisphenol A in the presence of a sulfonic acid ion-exchanger in at least one reactor, and in which the reactor, at the time when it is started up, is filled with sulfonic acid ion-exchanger with a bulk volume of 30 to 70 vol. % of the total reactor volume.

Abstract: A process for the production of bisphenol A is disclosed. The process entails a) mixing phenol and acetone to form a mixture, and b) bringing the mixture to a temperature of 48 to 54° C. to form a warm mixture, and c) commencing a reaction between phenol and acetone upon contacting the warm mixture with an acid ion exchange catalyst to form a product mixture that contains bisphenol A. The bisphenol A may be extracted from the product mixture by crystallization and filtration.

Abstract: An improvement to the process of producing polycarbonate resin by the phase interface method is disclosed. The improvement comprising adding at least one chlorinated aromatic hydrocarbon to the organic phase.

Abstract: A process for producing polycarbonate is disclosed. The process entails using equipment having leakage rate less than 10−3 liter He×mbar/sec. The polycarbonate thus produced is characterized by its enhanced thermal stability.

Abstract: The present invention relates to a process for working up solutions of polymers in organic solvents contaminated by alkaline constituents, using homogeneously soluble acids, especially by the introduction of an acid gas, and subsequent washing, and to the polymers so obtainable, which are distinguished by the fact that, on treatment with moist heat (sterilisation), only few defects caused by decomposition are formed, to the use thereof in the production of extrudates and molded specimen, and to the extrudates and molded specimen produced from those polymers themselves.

Abstract: The present invention relates to a process for working up solutions of polymers in organic solvents contaminated by alkaline constituents, using homogeneously soluble acids, especially by the introduction of an acid gas, and subsequent washing, and to the polymers so obtainable, which are distinguished by the fact that, on treatment with moist heat (sterilisation), only few defects caused by decomposition are formed, to the use thereof in the production of extrudates and molded specimen, and to the extrudates and molded specimen produced from those polymers themselves