摘要:
The preparation of aromatic polyesters based on diphenols and iso- and terephthalic acid is carried out by solventfree transesterification of esters of the diphenols with the aromatic dicarboxylic acids, the esters of the diphenols being initially reacted with teriphthalic acid alone and subsequently reacted with isophthalic acid after at least 80% of the terephthalic acid has undergone reaction.
摘要:
Aromatic polyesters based on diphenols and iso- and/or terephthalic acid are produced by transesterification of esters of the diphenols with the aromatic dicarboxylic acids in the melt by first reacting the aromatic dicarboxylic acids with a stoichiometric excess of the diphenol esters to form oligomers and then condensing the resulting oligomers to the aromatic polyesters with elimination and removal by distillation of diphenol ester.
摘要:
Fire-retardant polycarbonates, polyester carbonates and polyesters based on dihydroxydiphenyl cycloalkanes ##STR1## in which R.sup.1 and R.sup.2 independently of one another represent hydrogen, halogen, preferably chlorine or bromine, C.sub.1 -C.sub.8 alkyl, C.sub.5 -C.sub.6 cycloalkyl, C.sub.6 -C.sub.10 aryl, preferably phenyl and C.sub.7 -C.sub.12 aralkyl, preferably phenyl-C.sub.1 -C.sub.4 -alkyl, more especially benzyl,m is an integer of 4 to 7, preferably 4 or 5, R.sup.3 and R.sup.4 may be individually selected for each X and, independently of one another, represent hydrogen or C.sub.1 -C.sub.6 alkyl andX is carbon,with the proviso that, at at least one atom X, R.sup.3 and R.sup.4 are both alkyl,the fire-retardant finish being provided by additives and/or comonomers.
摘要:
Aromatic polyesters are prepared by the transesterification of aromatic dicarboxylic acid dialkyl esters with diester derivatives of divalent phenols at temperatures of about 260.degree. to 350.degree. C. with removal of the resulting monocarboxylic acid alkyl ester from the reaction mixture.
摘要:
Self-extinguishing optionally reinforced polyamide moulding compositions containing as flameproofing combination or phenol/aldehyde resin and phosphoryl nitride oxide or a precursor thereof.
摘要:
A three-step process for the production of solventless polycarbonate is disclosed. Accordingly, a mixture of two different oligocarbonates each prepared by the interfacial method, is prepared in the first process step. In a second step, the mixture is crystallized. The third step entails polycondensation. In an additional embodiment of the invention the first step uses a mixture of one oligocarbonate with a suitable monomer.
摘要:
This invention relates to the use of polyphenylene oxides corresponding to the following general formula: ##STR1## for the production of aromatic block polyether-poly(ester) carbonates by the interfacial process and also to the block polyether-poly(ester) carbonates obtainable by the process.
摘要:
A mixture comprising 1. from 70 to 99% by weight of a predominantly aromatic polycarbonate; and 2. from 30 to 1% by weight of a polyolefin graft polymer of (a) 70 to 95% by weight of a graft base consisting of a homopolymer of aliphatic and/or aromatic monoolefins or of a copolymer of these olefins, and up to 50% by weight of other monoolefinically unsaturated, radially polymerizable compounds and/or up to 5% by weight of diolefins, and (b) 5 to 30% by weight of at least one graft-polymerizable vinyl compound, the olefin graft polymers having been obtained by contacting a melt of the graft base (a) with oxygen or an oxygen-containing gas for at most 10 min. with intensive mixing under a pressure of from 1 to 150 bars and at a temperature of from 80.degree. C. to 300.degree. C., adding the vinyl compounds (b) to be grafted on immediately afterwards with intensive mixing in the absence of oxygen or oxygen-containing gas and removing the residual monomers after the graft polymerization reaction.
摘要:
Polymer blends with high notched impact strength comprising polyamide-6 with a relative viscosity of at least 3,5 and copolymers of ethylene, (meth)acrylic acid and esters of (meth)acrylic acid.
摘要:
The invention relates to a process for the preparation of aromatic polyester-carbonates wherein, in a first stage, aromatic oligo-esters or oligo-ester-carbonates having hydroxyl end groups are prepared from diaryl esters of aromatic dicarboxylic acids (or their starting materials) and diphenols and, optionally, a diaryl carbonate, by trans-esterification in the melt, and in a second stage these oligo-esters or oligo-ester-carbonates are condensed with phosgene by the phase boundary process to give the polyester-carbonate.