摘要:
Carbonates with aromatic ester groups can be produced by reaction of aromatic monohydroxy compounds with phosgene or with chloroformic acid esters of aromatic monohydroxy compounds, working at a temperature in the range of 50.degree. to 350.degree. C. in presence of oxides of the metals of Group IV B of the Mendeleeff periodic table as heterogeneous catalysts.
摘要:
Carbonates with aromatic ester groups may be prepared by reacting aromatic monohydroxy compounds with phosgene or with chloroformates of aromatic monohydroxy compounds, wherein the process is performed at a temperature in the range 50.degree.-350.degree. C. in the presence of aluminosilicates as heterogeneous catalysts.
摘要:
The invention relates to novel N-aryl-substituted nitrogen-containing heterocycles, several processes and novel intermediates for their preparation, and their use as herbicides and plant growth regulators.
摘要:
The present invention relates to a continuous process for preparing lower dialkyl carbonates as main product and alkylene glycol as by-product by transesterification of a cyclic alkylene carbonate (e.g. ethylene carbonate or propylene carbonate) with lower alkyl alcohols in the presence of a catalyst and also the required purification of the dialkyl carbonate in a subsequent process step. To optimize the economics and energy efficiency of the process, additional devices are used for intermediate heating of the liquid streams in the apparatus.
摘要:
The invention relates to bimetallic complexes in which the ligand contains a salophen unit which complexes copper, manganese or cobalt and a phenanthroline unit which complexes palladium and the two systems are linked by a continuous conjugated system. The invention further relates to the use of these bimetallic complexes as catalysts for the oxidative carbonylation of aromatic hydroxy compounds to form diaryl carbonates, a process for preparing diaryl carbonates using the bimetallic complex as catalyst and also diaryl carbonates prepared by oxidative carbonylation of aromatic hydroxy compounds using the bimetallic complexes of the invention as catalysts.
摘要:
A combined process for the preparation of polycarbonate from bisphenols and diaryl carbonates, the monophenol liberated being reacted again for the preparation of the diaryl carbonate and the alkali metal halide forming in the preparation of the diaryl carbonate being converted by electrochemical oxidation, optionally over a gas diffusion electrode, into chlorine and alkali hydroxide solution, the chlorine being recycled into the preparation of the phosgene and the alkali hydroxide solution being recycled into the preparation of the diaryl carbonate.
摘要:
A process is described for producing polycarbonate and utilizing at least some of the process waste water by concentrating the sodium chloride-containing waste water phases for the electrolysis using osmotic membrane distillation, if appropriate with simultaneous dilution of the sodium hydroxide solution obtained from the electrolysis for the polycarbonate production process.
摘要:
A process is described for producing polycarbonate and utilizing at least some of the process waste water by concentrating the sodium chloride-containing waste water phases for the electrolysis using osmotic membrane distillation, if appropriate with simultaneous dilution of the sodium hydroxide solution obtained from the electrolysis for the polycarbonate production process.
摘要:
The invention relates to a process for production of diaryl carbonate combined with the electrolysis of the resultant alkali metal chloride-containing process wastewater. The process according to the invention makes possible, inter alia, improved utilization in electrolysis of the alkali metal chloride-containing solution obtained in the production of diaryl carbonate.
摘要:
A method for reducing the content of fluorescent particles in polycarbonate is disclosed. The method entails bringing into contact polycarbonate, in the melt or in solution, with aluminosilicate at a temperature and for a time calculated to obtain polycarbonate having fluorescent particles content of 0 to 5 counts/g of polycarbonate. In a preferred embodiment the polycarbonate is passed through a column packed with zeolite.