Abstract: A method is provided for controlling the build-up in concentration of triorganoamine exchange catalyst in an organic extraction solvent used in the extraction of aromatic bis(ether phthalimide) and N-organo substituted phthalimide from an imide-anhydride exchange reaction mixture. The concentration of the triorganoamine exchange catalyst is controlled in the extracting organic solvent by extracting the organic solvent with an aqueous mixture of phthalic acid and triorganoamine and thereafter recycling the organic solvent to the extractor.

Abstract: Novel thermoplastic molding compositions are disclosed which comprise a polycarbonate molding powder in admixture with a minor amount of a volatile matter entraining agent selected from the group consisting essentially of monochlorobenzene, a polyhydric material and solutions of a polyhydric material in water. A method of preparing a polycarbonate molding composition containing reduced amounts of volatile impurities is also disclosed.

Abstract: Reinforced thermoplastic compositions are provided comprising a poly(1,4-butylene terephthalate) resin, a poly(ethylene terephthalate) resin, and a reinforcing, warp resisting combination of talc and silica. The compositions optionally include a segmented copolyester resin, a silicon polymer and/or a fibrous glass reinforcement. The compositions are moldable to articles having improved resistance to warpage during heat treatment in comparison with molding compositions of talc, (poly(1,4-butylene terephthalate) and poly(ethylene terephthalate).

Abstract: Reinforced thermoplastic compositions are provided which comprise a high molecular weight polyester and a mineral reinforcing filler comprising mica, talc or mixtures thereof in combination with a glass fiber reinforcement. The use of glass fibers together with the mineral reinforcement provides shatter resistance and further enhances other physical properties, such as tensile strength, modulus, impact strength and heat distortion temperature. Self-extinguishing embodiments are also disclosed.