摘要:
The present invention relates to polycarbonate, polyester carbonate and polyester having end groups derived from alkylsiloxane-substituted phenols, as well as to the use of phenolic compounds having alkylsiloxane substituents as chain terminators in the preparation of polycarbonate, polyester carbonate and polyester, as well as to mouldings and extrudates produced from these polymers, to processes for the preparation of the polymers, and to novel phenolic compounds of formula (2).
摘要:
A process for purifying polycarbonate is disclosed. The process entails filtering molten polycarbonate having weight average molecular weight of 14,000 to 30,000 g/mol through at least one non-woven metal structure having a thickness of 5 to 1 mm, said structure including at least one dense layer, and at least one less dense layer wherein said dense layer is 0.05 to 0.2 mm thick and has pore size of 1 to 10 μm to obtain pure polycarbonate.
摘要:
A process for the preparation of polycarbonate by the phase interface process is disclosed. The process includes (a) preparing a sodium hydroxide solution by chloralkali electrolysis, the solution containing not more than 30 ppm sodium chlorate relative to the weight of sodium hydroxide, and (b) reacting an aqueous solution of said sodium hydroxide with at least one dihydoxydiarylalkane to obtain a solution of disodium salt and (c) reacting said solution of disodium salt with phosgene in the presence of at least one organic solvent, a chain terminator and optionally a branching agent to obtain an oligocarbonate, and (d) condensing the oligocarbonate in the presence of at least one catalyst to obtain a material system containing polycarbonate and organic solvent and (e) separating off of the organic phase from said material system. The polycarbonate prepared by the inventive process is characterized by its low yellowness index.
摘要:
The present invention relates to a process for working up solutions of polymers in organic solvents contaminated by alkaline constituents, using homogeneously soluble acids, especially by the introduction of an acid gas, and subsequent washing, and to the polymers so obtainable, which are distinguished by the fact that, on treatment with moist heat (sterilisation), only few defects caused by decomposition are formed, to the use thereof in the production of extrudates and molded specimen, and to the extrudates and molded specimen produced from those polymers themselves.
摘要:
A transparent thermoplastic molding composition having good release properties is disclosed. The composition which contains no magnetic elements contains a polycarbonate resin and 0.01 to 0.3 percent by weight of a mold release agent. The agent is the product of a reaction of a compound represented by formula (I) ##STR1## where R.sub.1 denotes a C.sub.1-30 -alkyl group, with at least one member selected from the group consisting of ##STR2## where R.sub.2 and R.sub.3 independently denote C.sub.1-30 - alkyl or an aryl group, and ##STR3## where n is 1-7.
摘要:
A water-soluble carboxypolysaccharide-magnetic iron oxide complex of small particle diameter composed of a water-soluble carboxypolysaccharide and a magnetic iron oxide having a core diameter ranging from about 2 to about 7 nm, wherein the total diameter ranges from about 10 to about 50 nm, the ratio of the total diameter to the core diameter is about 15 or less, and the T.sub.2 -relaxivity ranges from about 10 to about 150 (mM.sec).sup.-1. Said complex has low toxicity and small side effects and is useful in the fields of medical treatment, biology and engineering as an iron-supplementing agent, an X-ray contrast medium, an MRI contrast medium, a reagent for blood flow rate measurement, a carrier for drug administration, etc.
摘要:
The present invention relates to the use of cyclic carbonates as demoulding agents for thermoplastic polycarbonates, and to the incorporation of these cyclic carbonates into the thermoplastic polycarbonates.
摘要:
Porphyrin complex compounds consisting of a meso-tetraphenylporphyrin ligand of general formula I ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 have varying meanings, and an ion of an element of atomic numbers 21-32, 38, 39, 42-51 or 58-83 as well as optionally one or more physiologically harmless cation(s) of inorganic and/or organic bases, amino acids or amino acid amides are valuable diagnostic agents.
摘要:
The present invention relates to thermoplastic aromatic polycarbonates having a content of special aryl phosphines, to their preparation, and to their use in the light engineering sector and in optics.