Abstract: The invention relates to a process for the production of polycarbonates by the two-phase interfacial method in which deviations between measured and estimated variables are continuously minimized by means of a suitably selected observer or filter system on the basis of a process model with an empirical Mark-Houwink relation adapted to the process. The variables estimated by the observer/filter are converted into control variables which are used to set input streams of the production process. Product quality is kept constant, changes in load or set values are quickly intercepted and even disturbances not readily accessible to measurement are taken into account by the process control.

Abstract: The present invention relates to a process for the preparation of polycarbonates in which an oil-in-water emulsion is maintained throughout by carrying out the reaction under special conditions.

Abstract: A process for the continuous production of a thermoplastic aromatic polycarbonate is disclosed. Accordingly, in a reactor system which includes a tube reactor and a tank equipped with a stirrer, there are reacted a preheated dialkali diphenolate aqueous solution with gaseous phosgene in CH.sub.2 Cl.sub.2 and/or in chlorobenzene solution containing excess phosgene, in a mixer to form a mixed emulsion. The emulsion is then transported at least partly against the force of gravity into the tube reactor to facilitate a polycondensation reaction and in which after a residence time of at least 10 seconds and without dissipation of the heat of reaction there is added a chain terminator. The heat of reaction is dissipated in said tank and aqueous sodium hydroxide and catalyst are added to complete the reaction. The process according to the invention leads to high yields of phosgene.

Abstract: Films from aromatic polyesters and from aromatic polyestercarbonates are excellently suitable for preparing printing ribbons, in particular for thermal and electrothermal recording processes.

Abstract: Films from aromatic polyesters and from aromatic polyestercarbonates are excellently suitable as electrically insulating films, for example as dielectric for capacitors and as conductor track films.

Abstract: Polyesters having at least 90%, by weight, of recurrent structural units corresponding to the following formula: ##STR1## and characterised by a relative viscosity.eta..sub.rel of from 1.6 to 4.5 (determined at 25.degree. C. in CH.sub.2 Cl.sub.2, c=5 g/l) are suitable for the production of films having highly advantageous performance characteristics, in particular high heat resistance.

Abstract: The present invention relates to the isolation of thermoplastic polycarbonates from their solutions by treating the organic solutions, obtained in the phase boundary processes, of the thermoplastic polycarbonates with vapors of benzene or alkylbenzenes.

Abstract: The invention relates to a process for the production of colorless, heat-stable and hydrolysis-stable aromatic polyesters and polyester carbonates by conventional interfacial polycondensation of aromatic dicarboxylic acid dichlorides and diphenolates in which dicarboxylic acid dichlorides are used which have been obtained by chlorination from the dimethyl esters of the corresponding acids, and tertiary cycloaliphatic amines are used as catalysts.

Abstract: High molecular weight aromatic polyesters having a low content of end groups and a very slight inherent color can be obtained according to the phase interfacial process wherein particular amines and a slight alkali excess are used.

Abstract: Diphasic mixtures obtained from the synthesis of aromatic polyesters by the diphasic interface process may be separated into an aqueous phase and an organic phase by the addition of selected compounds.

Abstract: The present invention relates to an improvement in the phase boundary polycondensation process for the preparation of aromatic, in particular thermoplastic, polycarbonates comprising carrying out the process in the presence of a saturated solution of alkali metal salts.

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: A process for the production of polyamide-6 or corresponding copolyamides by hydrolytic polymerization wherein the low molecular weight secondary reaction products and the unreacted .epsilon.-caprolactam are separated off from the polyamide melt and directly condensed on the .epsilon.-caprolactam melt to be polymerized.

Abstract: A method for the separate discharge of the individual phase streams of a multiple component flow comprising a high viscosity slow flowing liquid or suspension and a gas flowing at at least 100 times faster with the volumetric ratio of the gas to the liquid being greater than 1:1. The multicomponent flow is transversely fed through an inlet and directly into a rotating helical channel for conveying liquid in one direction. The channel has a liquid outlet spaced from the inlet in the one direction and a gas outlet spaced from the inlet in the opposite direction. A gas shut-off is formed between the inlet and the liquid outlet so as to effect the discharge of gas through the gas outlet in the opposite direction during the conveying of the liquid by the helical channel to the liquid outlet in the one direction.

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: The invention relates to a process for rendering flame-resistant the thermoplastic aromatic polycarbonates prepared by a solution process, characterized by dispersing an aqueous solution of salt-like flameproofing agent in a washed and neutral polycarbonate/organic solvent system.

Abstract: Phosphoric acid triesters of the formula ##STR1## are produced in two or more stages by reacting phosphorus oxyhalides, phosphorus pentahalides, phosphoric acid monoester dihalides or phosphoric acid diester halides corresponding to the following general formula:ZO PO Hal.sub.2 (ZO).sub.2 PO Halwherein Z is defined as above and Hal represents Cl and/or Br with at least one hydroxyaryl compound of the formula ##STR2## in a two-phase mixture of an organic solvent an aqueous alkaline earth metal and/or alkali metal hydroxide solution.

Abstract: This invention provides spheres of high molecular weight thermoplastics filled with short glass fibers which may be easily metered, incorporated into thermoplastic resins or fused into glass mats or shaped articles. It also provides a method of producing such spheres by treating glass fibers with a dilute (1 to 30 wt% strength) solution of the plastic having a viscosity of less than 1,000 cP. The fibers are rotated with the polymer solution and the solvent is subsequently evaporated off. Preferably, the coating plastic is a high molecular weight thermoplastic.

Abstract: The present invention provides a process for the preparation of a polycarbonate by the phase boundary condensation method, by phosgenation of an aqueous alkali metal salt solution of one or more aromatic dihydroxy compounds, in which process an aromatic chlorinated hydrocarbon is used as the solvent and the synthesis of the polycarbonate is carried out in two stages, in the first stage of which the reaction of the alkali metal salt solution of the aromatic dihydroxy compound(s) with phosgene is carried out at an OH concentration of between 0.01 and 0.1% by weight of OH, relative to the aqueous phase, in the presence of 0.1 to 2.5 mol% of trialkylamine, relative to aromatic dihydroxy compound(s), and at a temperature higher than 70.degree. C, with a dwell time of less than 5 minutes, while in the second stage the polycondensation is effected by adjusting the OH concentration to 0.20 to 0.

Abstract: A process for the preparation of a symmetric diarylcarbonate by reacting phosgene with a phenol wherein said reactions is carried out by the phase interface process in a diphastic mixture of an aqueous alkali metal hydroxide solution and a liquid diaryl carbonate in the presence of from 0.001 to 0.1 mol of a tertiary amine or a quaternary ammonium compound per mol of phenol.