摘要:
Anionic copolymers of lactams and aliphatic polycarbonates having urethane and carboxylic acid ester groups, preferably having recurring structural units of the formula:--NH--CO--O--Y--O--CO--(CR.sub.2).sub.n --whereinR represents hydrogen or C.sub.1 -C.sub.4 -alkyl;n represents an integer of from 2 to 13;Y represents the residue of an alcohol of the following formula:HO--X--OH,whereinX represents an open-chain, cyclic or mixed open-chain-cyclic alkylene radical having from 2 to 12 carbon atoms which is optionally substituted by C.sub.1 -C.sub.4 -alkyl and optionally interrupted by from 1 to 3 oxygen atoms, or a polyethylene glycol having a molecular weight up to 10,000 or an alkoxylation product of bifunctional phenols.
摘要:
The invention is directed to a process for the preparation of polycarbonates of Mw 20,000 to 180,000 by transesterification of diphenols and carbonic acid dialkyl esters in the presence of organo-tin-IV compounds and a monophenol.
摘要:
The present invention relates to an interfacial process for the production of polycarbonates having terminal, aliphatically bonded hydroxyl groups by reacting predominantly dihydric alcohols with phosgene or chlorocarbonic acid esters of predominantly dihydric alcohols and/or phenols using alkali liquors as HCl-binding agents and in the presence of inert solvents, the process according to the invention being distinguished by the fact that concentrated, aqueous alkali liquors are used as the HCl-binding agents and thiodiglycol, optionally mixed with additional monohydric and polyhydric alcohols, is used as the dihydric alcohol. The present invention further relates to the new polycarbonates produced according to the novel process and to the use of these new polycarbonates for the production of polyurethane plastics.
摘要:
A process for the production of light colored condensation resins, wherein phenols are reacted with .alpha.,.alpha.'-dihydroxy-diisopropyl benzenes in the presence of acids of phosphorus at temperatures of between 70.degree. and 270.degree.C.
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:
The present invention relates to a process for the production of bis-(4-hydroxyaryl)-alkanes by a heterogeneously catalyzed reaction of aromatic hydroxy compounds with ketones in at least two reactors connected in series, which, as the reaction progresses, are operated at higher temperatures, wherein the total quantity of ketone is divided between the individual reactors in such a manner that the higher is the temperature of the particular reactor, the smaller is the proportion per reactor, the highest possible reactor loading is maintained and the temperatures and temperature gradients are kept as low as possible.
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:
Catalyst systems with a content of a platinum-group-metal catalyst, a co-catalyst, a quaternary salt and a base for the oxidative carbonylation of aromatic hydroxy compounds to the corresponding diaryl carbonates are according to the invention obtained as a mother liquor by suspension crystallization and can be returned into the carbonylation reaction or worked up to valuable materials. The crystallizate, which consists predominantly of diaryl carbonate and the parent aromatic hydroxy compound, is worked up to pure diaryl carbonate and pure hydroxy compound.
摘要:
Aromatic amines are produced by catalytic hydrogenation of nitroaromatic compounds in the gas phase. The catalyst includes palladium and lead on graphite or on a graphite-containing coke support. From 30 to 6000 equivalents of hydrogen for each equivalent of nitro groups are contacted with the catalyst during this process.
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.