摘要:
Siloxane/polyester (carbonate) block copolymers comprising wholly aromatic polyester or polyestercarbonate units and from 0.5 to 7.5% by weight of polysiloxane blocks, exhibit an improved melt flowability without impairment of the heat stability.
摘要:
The new polyester carbonate-polysiloxane block copolymers having recurrent structural units of the following formulae ##STR1## have improved resistance to petrol compared with known polyester carbonate-polysiloxane block copolymers. They are used for the manufacture of moulded products, in particular those used under the engine bonnet of a motor vehicle or as external parts of motor vehicles.
摘要:
Mixtures of aromatic polycarbonates and aromatic polyester-carbonates having a specific polycarbonate/polyester-carbonate ratio and a defined ester content in the polyester-carbonates, at least one of the polycondensates containing C.sub.8 -C.sub.9 -alkylated phenyl end groups, possess a reduced tendency to stress cracking.
摘要:
Thermoplastic polyphosphonatocarbonate prepared by polycondensing at least one aromatic dihydroxy compound with a diaryl carbonate and a phosphonic acid diaryl ester in the presence of a basic polycondensation catalyst at a temperature of from 80.degree. to 340.degree. C. and under a pressure of 600 to 0.1 mm Hg in an inert gaseous atmosphere, the molar ratio of diaryl carbonate to phosphonic diaryl ester being from 5:95 to 95:5 and the molar ratio of aromatic dihydroxy compound to the sum of diaryl carbonate and phosphonic acid diaryl ester being from 0.91:1 to 0.99:1, and following polycondensation, neutralizing said basic catalyst.
摘要:
Thermoplastic, branched aromatic polyphosphonates with average molecular weights (number average M.sub.n) of from 11,000 to more than 200,000, obtainable by transesterifying (a) from 97 to 100 moles of at least one diaryl phosphonate, and (b) from 0 to 3 moles of at least one triaryl phosphate--the sum of the moles of (a) and (b) being 100--with (c) from 90 to 99 moles of at least one aromatic dihydroxy compound, and (d) from 0 to 3 moles of at least one aromatic trihydroxy or tetradhydroxy compound--with the proviso that at least one of the components (b) and (d) is present in a quantity of at least 0.001 mole and that, where (b) and (d) are used, the maximum limit on the moles is 3.0.
摘要:
A single-stage process for the production of pure aromatic carboxylic acid chlorides by reacting an aromatic carboxylic acid or an aromatic carboxylic acid mixture with thionylchloride in the presence of tert. phosphine as the catalyst.
摘要:
Polyester phosphonates based on aromatic dicarboxylic acids and aromatic dihydroxy compounds exhibit a low flammability and surprisingly improved mechanical characteristics, particularly an excellent dimensional heat stability.
摘要:
A one-stage process for the preparation of pure aromatic dicarboxylic acid dichlorides by reacting an aromatic dicarboxylic acid or an aromatic dicarboxylic acid mixture with phosgene, optionally, in a solvent or diluent, with phosphine imines, phosphorimidates or mixtures thereof as catalysts.
摘要:
Thermoplastic aromatic polycarbonate molding compositions with improved flame retardancy which contain an alkali metal salt of an organic or inorganic acid and optionally a perfluoroethylene, characterized in that they contain a tetrahalogenophthalimide of the general formulae (I) or (II) or mixtures thereof ##STR1## wherein R denotes a hydrogen atom or a C.sub.1 to C.sub.4 l alkyl, C.sub.6 H.sub.5, C.sub.10 H.sub.7, C.sub.6 H.sub.4 X, C.sub.6 H.sub.3 X.sub.2 or C.sub.6 H.sub.2 X.sub.3 group, in which X denotes a fluorine, chlorine or bromine atom, R' denotes a single bond or a C.sub.2 to C.sub.4 alkylene, C.sub.6 H.sub.4 or p-diphenylene radical, and Z denotes a chlorine or bromine atom,are provided.