Abstract: The present invention relates to a process for isolating polycarbonates in which a solution of polycarbonate in an organic solvent is dispersed with steam and which is characterized in that the resulting suspension of polycarbonate particles, condensed water and water/solvent vapor is subsequently dried in a tube with cross-sectional constrictions.

Abstract: The invention relates to a process for the production of bisphenols from acetone and phenols in the presence of sulfonic acid ion exchanger resins modified with alkyl-SH groups, in which 0.6 to 5% by weight H.sub.2 O is added to the mixture of phenol and acetone before the reaction.

Abstract: The invention relates to a special process for the production of high-purity bisphenol A from acetone and phenol in the presence of acidic catalysts.

Abstract: This invention relates to a catalyst modified with mercapto amines, its preparation and its use for the preparation of bisphenols.

Abstract: The invention relates to ultrafine suspensions of bisphenol, sodium hydroxide and water for the production of polycarbonates by the two-phase interfacial process. According to the invention, these suspensions are prepared by cooling bisphenolate concentrations near the solubility limit in aqueous sodium hydroxide with intensive mixing at relatively high temperatures and precipitating bisphenolate or more bisphenolate in the form of fine droplets during the cooling process. The ultrafine suspensions provide for a high volume/time yield in the interfacial reaction.

Abstract: A continuous process for the removal of electrolytes and catalysts from organic polycarbonate solutions is disclosed. Accordingly, a solution obtained in the course of the two-phase interfacial reaction for the preparation of polycarbonate, containing thermoplastic aromatic polycarbonate and an organic solvent and up to 10 parts by weight water as well as residues of chain terminators, branching agents and diphenols is washed with water and/or hydrochloric acid through a cascading train of centrifuges. The resulting polycarbonate resin is characteristically of extremely low iron content.

Abstract: An improvement to the continuous process for the production of polycarbonates by interphase polycondensation is described. Accordingly, the organic phase and the aqueous phase are combined in a tube, forming chlorocarbonic acid ester and further alkali hydroxide is added at, or shortly after, the maximum concentration of said ester is reached. The resulting emulsion is then changed to an oil-in-water emulsion which is then separated and worked up in known manner.

Abstract: This invention relates to a catalyst modified with mercapto amines, its preparation and its use for the preparation of bisphenols.

Abstract: The invention relates to a process for the preparation of polyamide moulding compositions containing 0.1 to 40 wt. % of a polyarylene sulphide by reaction of polyamide-forming components in the presence of polyarylene sulphides.

Abstract: This invention relates to a process for the preparation of bisphenols and bisphenol mixtures by the isomerization of bisphenols on acid or alkaline catalysts in the presence of the corresponding phenols.

Abstract: By treating aromatic polycarbonates, aromatic polyester carbonates and aromatic and/or araliphatic polyesters in the molten state with super-critical gases or gas mixtures under pressure, the melt viscosity of these polymers is considerably lowered so that basic chemical operations which proceed only incompletely under the usual conditions can be carried out on these thermoplasts.

Abstract: Recovery of thermoplastic polymer solids from dispersions thereof by coagulation and subsequent washing of the solids is improved by contacting the polymer in the coagulation stage or the washing stage or in both stages with at least one tricarboxylic acid of the formula ##STR1## wherein X is a single covalent bond, --CH.sub.2 -- or --C.sub.2 H.sub.

Abstract: This invention relates to an ionic exchanger modified with thiazolines, to its preparation and to its use for the preparation of condensation products, particularly bisphenols.

Abstract: Thermoplastic moulding materials, with improved toughness at low temperatures, of polyamide and cross-linked graft rubbers from the diene rubber and acrylate rubber series, obtained by heating blends of the two components below the melting point of the polyamide.

Abstract: Process for the preparation of pure aromatic dicarboxylic acid dichlorides which comprises reacting an aromatic dicarboxylic acid or an aromatic dicarboxylic acid mixture with phosgen in one stage and in the presence of an N--C.sub.1 --C.sub.6 -alkyl-pyrrolidine, -piperidine or -morpholine as a catalyst and optionally in a solvent or diluent.

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: A process for the preparation of a neutal phosphorous acid aryl ester of the general formula ##STR1## wherein a phosphorus trihalide, phosphorus acid monoester dihalide or phosphorous acid diester halide is reacted with a hydroxyaryl compound wherein an excess of hydroxyaryl compound and an excess of aqueous alkali metal hydroxide solution or suspension or alkaline earth metal hydroxide solution or suspension are employed, relative to the phosphorus halide compound, an inert water immiscible organic solvent and/or diluent is employed in an amount such that 5 to 50% strength solution of the neutral phosphorous acid aryl ester is formed and after the reaction, the organic phase is separated off and the phosphorous acid aryl ester formed is isolated by removing the solvent and/or diluent.

Abstract: The present invention relates to a process for the preparation of aromatic polycarbonates from diphenols by the phase boundary process, which is characterized in that cyclic, preferably monocyclic or bicyclic, aza compounds are used as catalysts. The present invention also relates to the polycarbonates obtainable according to the process, which are distinguished by high light transmission and a low tendency to yellowing, even after relatively severe exposure to heat.

Abstract: Phosphoric acid esters are produced by the method of phase-interface condensation by reacting phosphorus oxyhalides, phosphorus pentahalides, phosphoric acid monoester dihalides or phosphoric acid diester halides with hydroxyaryl compounds in the presence of aqueous alkaline earth metal and/or alkali metal hydroxide solutions and organic water-immiscible solvents.

Abstract: This invention relates to a process for the preparation of bisphenols and bisphenol mixtures by the isomerization of bisphenols on acid or alkaline catalysts in the presence of the corresponding phenols.