摘要:
Polyether polyols can be prepared by reacting polyols with epoxides in the presence of basic catalysts, by treating the polyether polyols containing the basic catalysts with OH-functional solid compounds of metals of groups III to VIII of the periodic system of the elements (Mendeleyev), the compounds being insoluble in the polyether polyols and having BET surface areas of from 10 to 1000 m2/g, isolating the solid inorganic compounds laden with the basic catalysts from the polyether polyol and using them in the reaction of polyols with epoxides, or bringing the isolated inorganic compounds laden with the basic catalysts into contact with the polyols that are to be used in the reaction with epoxides, separating those polyols from the inorganic compounds and delivering them to the reaction with epoxides.
摘要:
A process for purifying aromatic carbonate polymers, including polycarbonates and polyestercarbonates, is disclosed. Accordingly, a carbonate polymer is an organic solvent is rendered virtually free of low molecular weight components by agitation with aluminosilicate or by passing through layers of such aluminosilicate. The aluminosilicate is subsequently separated off and the carbonate polymer is isolated in known methods.
摘要:
4-Aminodiphenylamines are prepared by hydrogenating nitrosobenzene or mixtures of nitrosobenzene and nitrobenzene with hydrogen in the presence of fluorides and heterogeneous catalysts in inert aprotic solvents at temperatures from 0 to 200.degree. C. and pressures from 0.1 to 150 bar.
摘要:
The present invention relates to a process for the continuous production of carbonates having aromatic ester groups by the reaction of aromatic hydroxy compounds with phosgene in the presence of heterogeneous catalysts, phosgene still present being removed from the stream of waste gas by returning the waste gas to an additional reactor.
摘要:
The present invention relates to a process for the continuous production of diaryl carbonates by reaction of aromatic hydroxy compounds with phosgene in the presence of heterogeneous catalysts.
摘要:
The present invention relates to new 5-trihalogenomethyl-isoxazoles of the formula (I) ##STR1## in which x represents 1, 2 or 3, and a process for their preparation by reacting the corresponding trichloromethylisoxazole with a fluorinating agent.
摘要:
Novel .beta.-fluoroacyl-.beta.-halogenovinyl alkyl ethers of the formula ##STR1## in which R.sup.1 is a fluorinated alkyl group having 1 to 9 carbon atoms,Hal is a halogen atom, andR.sup.2 is an alkyl group having 1 to 7 carbon atoms,useful as insecticide intermediates, are produced by reacting a .beta.-fluoroacylvinyl ether of the formulaR.sup.1 --CO--CH.dbd.CH--OR.sup.2 (II)with a halogenating agent at a temperature of -70.degree. C. to +80.degree. C., to produce a halogenation product of the formula ##STR2## and dehydrohalogenating (III) at a temperature of -20.degree. C. to +100.degree. C.
摘要:
Arthropodically active 3-halogenoalkyl-1-arylpyrzoles of the formula ##STR1## in which R.sup.1 represents halogenoalkyl,R.sup.2 represents cyano, or represents hydroxycarbonyl, or represents carbamoyl or thiocarbamoyl, or represents alkoxycarbonyl, N-alkylcarbamoyl or N,N-dialkylcarbamoyl, or represents alkenyloxycarbonyl, N-alkenylcarbamoyl or N,N-dialkenylcarbamoyl, or represents alkinyloxycarbonyl, N-alkinylcarbamoyl, N,N-dialkinylcarbamoyl or N-arylcarbamoyl, or represents alkylcarbonyl, halogenoalkycarbonyl or cycloalkylcarbonyl,R.sup.3 represents hydrogen, alkyl, halogenoalkyl or cycloalkyl andAr represents substituted phenyl, with the exception of the 2,4-dinitrophenyl radical.
摘要:
The present invention relates to a process for the continuous preparation of diaryl carbonates from phosgene and at least one monohydroxy compound (monophenol) in the presence of catalysts, and also the use thereof for preparing polycarbonates. The hydrogen chloride formed in the reaction is converted by thermal oxidation into chlorine, with the chlorine being recirculated to the preparation of phosgene. In particular, the process comprises utilization of the hydrogen chloride formed for the process for preparing diphenyl carbonate (DPC process).
摘要:
The invention relates to a process for preparing diaryl carbonates and/or alkyl aryl carbonates from dialkyl carbonates and aromatic hydroxy compounds using a reactive dividing wall column.