Abstract: Disclosed herein are a polyamide resin of a relative viscosity of from 2.5 to 6, having hydrocarbon group(s) of 6 to 22 carbon atoms as the end group(s) thereof, the number of the hydrocarbon group(s) being 40 to 100% of the total number of the end groups of the polyamide, and a process for producing the polyamide resin.

Abstract: An aqueous dispersion of silicic anhydride, comprising an aqueous solvent and silicic anhydride dispersed therein, wherein the silicic anhydride has a surfacial silanol group density of from 0.3 to 3 per 100 .ANG..sup.2 and is obtained by the surface treatment of silicic anhydride produced by a dry method.

Abstract: A particulate polycarbonate resin composition which is separated from a solution of an inorganic filler-containing polycarbonate in an organic solvent at a temperature lower than the melting point of the polycarbonate, and contains an inorganic filler, said composition having a particle size distribution n of from 3 to 8 as represented by the following Rosin-Rammler distribution equationR=100 exp (-b Dp.sup.n)where R is an on-sieve amount (% by weight), Dp is a particle diameter (mm), and b is a constant, the particle diameter of the 50% on-sieve weight integration being from 0.5 to 6 mm, and the bulk density being from 0.1 to 0.7 g/ml.

Abstract: A process for producing polycarbonate resin particles from a methylene chloride solution of a polycarbonate resin obtained by the polycondensation of a dihydroxydiaryl compound and phosgene, which comprises continuously supplying the methylene chloride solution of the polycarbonate resin to a particle-forming vessel, heating it while maintaining it in a suspended state in water to evaporate methylene chloride and to form an aqueous slurry containing polycarbonate resin particles, subjecting at least a part of the resulting aqueous slurry withdrawn from the particle-forming vessel and containing the polycarbonate resin particles to wet pulverization treatment and recycling at least a part of the treated polycarbonate resin particles to the particle-forming vessel.

Abstract: A process for producing aromatic polyester polycarbonate particles from a methylene chloride solution of an aromatic polyester polycarbonate comprises continuously supplying the methylene chloride solution of an aromatic polyester polycarbonate to a particle-forming tank, heating it while maintaining it in a suspended state in water to evaporate methylene chloride and to form aromatic polyester polycarbonate particles, subjecting at least a part of the resulting aqueous slurry withdrawn from the particle-forming tank and containing the aromatic polyester polycarbonate particles to wet pulverization treatment and recycling the treated slurry to the particle-forming tank.

Abstract: An aromatic polyesterpolycarbonate containing a dihydroxy-diaryl compound residue, a terephthalic acid residue and/or isophthalic acid residue, and a carbonate bond in a molar ratio of 1:0.25-0.75:0.75-0.25 is prepared by first mixing and reacting an aqueous alkaline solution of a dihydroxy-diaryl compound, an organic solvent solution of terephthaloyl chloride and/or isophthaloyl chloride, and phosgene to obtain a polyesterpolycarbonate oligomer having --OCOCl groups, --COCl groups and --OH groups as end groups and then subjecting the oligomer to polycondensation with a caustic alkali in the substantial absence of the dihydroxy-diaryl compound.

Abstract: A process for producing an aromatic polyesterpolycarbonate, which comprises polycondensing (a) a dihydroxydiaryl compound, (b) a terephthaloyl chloride and/or isophthaloyl chloride reactant, and (c) phosgene by an interfacial polymerization process in the presence of water, methylene chloride and an acid binding agent thereby preparing an aromatic polyesterpolycarbonate product containing structural units of the formula: ##STR1## wherein X is a divalent group, and the aromatic rings may be substituted, and structural units of the formula: ##STR2## wherein X is a divalent group, and the aromatic rings may be substituted, said condensation reaction being characterized in that after at least 95% of the total --COCl groups in the terephthaloyl chloride and/or isophthaloyl chloride and phosgene starting materials has reacted, a chloroformate compound or additional phosgene is added to the reaction mixture in an amount to bring the concentration of --COCl groups to a level of 10 to 1000 .mu.

Abstract: A crude organic solvent solution of a polycarbonate containing an impurity is washed with an aqueous washing liquid by forming a water in oil dispersed phase by mixing the crude solution of the polycarbonate with a small amount of aqueous washing liquid in order to form the water in oil dispersed phase and then causing a phase inversion from the water in oil dispersed phase into an oil in water dispersed phase, and then, separating the organic solvent solution of the polycarbonate from the aqueous washing liquid.

Abstract: A process for producing a halogen-containing polycarbonate resin characterized by washing, with an aqueous washing liquid, an organic solvent solution of a mixture of a halogen-containing polycarbonate resin having a halogen content of not less than 4 wt % (hereinafter referred to simply as polycarbonate H) and a polycarbonate resin having a halogen content of not larger than 4 wt % (hereinafter referred to simply as polycarbonate P) the weight ratio of polycarbonate P to polycarbonate H being 0.05-4, and collecting a mixed polycarbonate resin having a halogen content of not less than 4 wt % from said solution.

Abstract: A halogen-containing polycarbonate resin is formed by co-polymerizing:(a) 15 to 55 parts by weight of a polycarbonate oligomer with terminal chloroformate groups, having a number average molecular weight of 500 to 10,000 and containing no aromatic halogen or less than 4% by weight of aromatic halogen,(b) 20 to 80 parts by weight of a halogen-containing polycarbonate oligomer with terminal chloroformate groups, having a number average molecular weight of 1,000 to 10,000 and containing 6 to 30% by weight aromatic halogen, and(c) 5 to 25 parts by weight of bisphenol A.

Abstract: An aromatic polyester-polycarbonate resin which comprises a polymer material composed of repeating units of structures I-III: ##STR1## wherein X is a divalent organic radical and the divalent aromatic entities in structures I, II and III may be substituted by hydrocarbon residues.

Abstract: An aromatic polyester-polycarbonate is prepared by(a) forming a low molecular weight polyester oligomer possessing terminal -OH groups by reacting a solution of a terephthaloyl chloride compound in an organic solvent with a dihydroxy-diaryl compound in an aqueous alkaline solution;(b) reacting said oligomer with phosgene thereby converting said terminal -OH groups to terminal -OCOCl groups; and(c) preparing the desired aromatic polyester-polycarbonate product by polycondensing the product of step (b) with a dihydroxy-diaryl compound in an aqueous alkaline solution.

Abstract: A polyester is produced in an improved process by esterification or interesterification of an aromatic dicarboxylic acid or an alkyl ester thereof with 1,4-butanediol followed by polycondensation of the resulting ester characterized in reusing the 1,4-dibutanediol mixture distilled in the polycondensation step without purification as a starting material for production of more polyester.