Abstract: The present invention relates to a process for the continuous production of carbonates having aromatic ester groups by reacting aromatic hydroxy compounds with phosgene in the gas phase in the presence of heterogeneous catalysts.

Abstract: 1. Thermoplastic molding compounds containingA. 5 to 95 parts by weight of an aromatic polycarbonate,B. 1 to 50 parts by weight of a vinyl copolymer andC. 5 to 95 parts by weight of one or more graft polymers obtained by graft polymerization,characterized in that 10 to 100% of component A is replaced by a mixture of two polycarbonates A.1 and A.2 of identical structure,1) the relative solution viscosity of A.1 being 1.18 to 1.24,2) the relative solution viscosity of A.2 being 1.24 to 1.34 and3) the difference between the relative solution viscosities of A.1 and A.2 being greater than or equal to 0.

Abstract: A circuit arrangement for operating a gas-discharge lamp is proposed, in which the high voltage for starting the gas-discharge lamp is generated by means of the energy stored in a transformer or capacitor. In order to obtain a steep rise in voltage of the starting voltage, the starting voltage is provided to the gas-discharge lamp via a voltage-controlled switch. A break-over diode, which has very short switching times, is proposed as the voltage-controlled switch. The starting circuit is switched off after starting. This circuit arrangement is also particularly suitable for starting gas-discharge lamps which are warm from operation. In consequence, it is particularly suitable for motor vehicle headlights.

Abstract: A process for the purification of bisphenols by distillation.

Abstract: The invention relates to a process for stabilizing the molecular weight of high molecular weight, optionally branched polyarylene sulfides prepared by reaction of aromatic dihalogen compounds and, optionally, aromatic trihalogen or tetrahalogen compounds and, optionally, polymer-chain-terminating monomers with alkali metal sulfides and/or alkali metal hydrogen sulfides at elevated temperature in aprotic polar solvents, characterized in that, after the desired molecular weight has been reached, alkali metal sulfides and/or alkali metal hydrogen sulfides present in excess are at least partly reacted with acids to form the alkali metal salts of the acids and hydrogen sulfide.

Abstract: A process for the purification of waste of thermoplastic resins containing at least one member selected from among aromatic polycarbonates, aromatic polyester carbonates and aromatic polyesters and at least one of aluminum, lacquers and dyes which waste accumulates in the production of optical moldings is disclosed. The process which entails size reduction of the waste, chemical wash and filtering steps yields purified resins suitable for thermoplastic processing.

Abstract: A process is disclosed for the purification of lacquer-and optionally dye and metal- containing waste of thermoplastic aromatic polycarbonates and/or thermoplastic aromatic polyester carbonates. The waste which result upon the production of moldings, such as audio compact discs, lenses for spectacles or head-lamp reflectors is processed in accordance with the invention to yield useful resin suitable for reprocessing as a molding resin. In accordance with the process, the waste is first size-reduced and then heated with acid to the reflux temperature while stirring. After a water wash there is followed a drying step. In accordance with the process, in instances where the waste does not originally contain metal, the metal in powder form is added before the acid treatment.

Abstract: The invention relates to mixtures of polyarylene sulphides, maleimides, glass fibres and if appropriate other additives. The mixtures are distinguished by good mechanical properties.

Abstract: The invention relates to mixtures of poly(arylene sulphides), glass fibres and maleamidic acids, which are remarkable for good mechanical properties and an increased melt viscosity of the matrix resin.

Abstract: The invention relates to new sulphur-containing copolymers, a process for their preparation from a sulphur source and a mixture of dihalogenoaromatics and dihalogenoaliphatics and their use for the production of shaped articles.

Abstract: This invention relates to a process for the preparation of crystalline polyarylenesulphides. Polyarylenesulphides with a high degree of purity, low electrolyte content and low non-uniformity are obtained. The polyarylenesulphides obtained have improved mechanical and electrical properties.

Abstract: This invention relates to a process for the preparation of N-alkylated caprolactams by the cyclization of N-alkylated caproic acids.

Abstract: The invention relates to polyarylene sulphides with melt viscosities settable to defined values. The products are distinguished by high stability of the melt. They are obtained by adding, in the preparation of these polyarylene sulphides, certain phenols as chain terminators to the reaction mixture.

Abstract: This invention relates to a process for the production of compounds containing at least one (thio)-hydantoin ring in the molecule by reacting a carbodiimide with hydroxy- or mercapto-succinic acid diesters corresponding to the following general formula: ##STR1## wherein R.sup.4 and X are as defined in the description.

Abstract: The invention relates to a process for the production of compounds containing at least one hydantoin ring by reacting a carbodiimide with derivatives of succinic acid anhydride corresponding to the following general formula: ##STR1## wherein R.sup.4 represents a halogen atom, an alkyl-carboxy or aryl-carboxy group; or with maleic acid anhydride in the presence of aromatic OH-functional compounds at temperatures of from about 20.degree. to about 250.degree. C., optionally in a solvent and optionally in the presence of a catalyst, and also to the use of the polyhydantoins obtained, where they have high molecular weights, as high temperature-resistant coating compositions, films, powders, adhesives, lacquers or mouldings.

Abstract: The invention relates to a new process for the production of compounds containing at least one hydantoin ring by reacting a carbodiimide with a derivative of an .alpha.,.beta.-unsaturated carboxylic acid corresponding to the following general formula: ##STR1## wherein R.sup.3, R.sup.4 and R.sup.5 are as defined in the description.

Abstract: A process for the preparation of bisphenols, which comprises condensing an aliphatic or cycloaliphatic ketone with a phenol having a free p-position in the presence, as a condensing agent, of from 0.3 to 3 mols, per mol of ketone, of an aromatic sulphonic acid of the formula (III) or (IV): ##STR1## wherein R.sup.3 is an inert organic radical,o represents an integer from 1 to 4, andp represents 0 or an integer from 1 to 4, and in the presence of an organic solvent, in which the aromatic sulphonic acid is effectively soluble and the bisphenol or the phenol adduct which is produced is as slightly soluble as possible, the reaction being carried out at a temperature at which the produced diphenol crystallises as extensively as possible as such or as a phenol adduct during or at the end of the reaction; isolating the crystalline separated bisphenol or its adduct; and removing the adhering phenol or solvent.

Abstract: The system includes equipments necessary for demand registration and control organized hierarchically. The uppermost hierarchy level includes an operations control center and station equipment connected to the operations control center. The operations control center indicates the operation necessary at the next hierarchy level in accordance with the demand registered in the station equipment. The next hierarchy level includes one or more command and control centers. Each command and control center checks the commands of the operations control center and/or of the associated station equipment, giving special consideration to safety criteria, and passes on the commands to the last hierarchy level for execution. The last hierarchy level includes operation facilities, such as vehicles, which perform the requested transport tasks, continuously exchanging information with their associated command and control center.