General Electric Company

Frank N Liberti

Willem F Borman

Gerald F Macke

Ronald L Dieck

Robert J Axelrod

Allen D Wambach

John Semen

Epoxy compounds are added to polycarbonate resin to reduce or eliminate the necessity of drying the resin prior to a foaming process.

Polycarbonate resin foam

A process is provided for increasing the rate of crystallization of polyester compounds, such as poly (alkylene arylates), more particularly poly(alkylene terephthalates), or blends or mixtures thereof, as for example, poly(ethylene terephthalate), poly(butylene terephthalate) or mixtures of blends thereof, by incorporating therein a small amount of a polyethylene ionomer, or an alkali metal salt of benzoic acid, such as sodium benzoate. The faster crystallization rates improve injection molding performance of the polyesters and blends thereof, such as reduced post-mold shrinkage, faster mold cycle times and lower mold temperature. Also, the resultant products show increases in physical properties such as flex modulus, flex strength, deflection temperature under load (DTUL), tensile strength and solvent resistance. The process is applicable not only to unfilled polyester compounds but also to mineral or glass-filled, or fire-retardant-containing compounds, to impact modified polyesters, as well as blends of polyesters, such as poly(ethylene terephthalate)/poly(butylene terephthalate) (PET/PBT) blends, unfilled and filled with the aforesaid components.

Process for increasing the rate of crystallization of polyesters

Polybutylene terephthalate molding compositions which contain a small amount of ethylene-ethyl acrylate copolymer, or an ethylene-vinyl acetate copolymer, or a mixture of these copolymers, and optionally polyethylene, provide moldings which in preferred embodiments possess improved impact resistance and lower specific gravity, without more than negligible loss of other properties. Other conventional modifiers can be present.

Polybutylene terephthalate molding compositions and articles molded

A process for the production of a foamed thermoplastic composition which comprises blending a minor amount of a foaming agent with a thermoplastic resin in an extruder and comminuting the resultant extrudate.

Process for the production of a foamed thermoplastic composition

The melt viscosity of high molecular weight linear polyesters is stabilized in the presence of aromatic (poly-)carbonates by adding a minor proportion of a non-volatile monofunctional ester-forming compound to a mixture of glycol and terephthalate or isophthalate reactants and heating the resulting mixture. The products of the process are suitable for conversion to compositions with aromatic (poly-)carbonates, especially flame retarded such compositions, where stabilized melt viscosity during fabrication is critical.

Process for the preparation of polyesters having stabilized melt

A thermal oxidatively stable aromatic polycarbonate composition which is stabilized with a minor amount of a phosphonite, which phosphonite has the general following formula: ##EQU1## Preferably, the phosphonite is diphenylbenzene phosphonite. The composition may also have included with it particular epoxy compounds.

Thermally stable polycarbonate

A thermally stable aromatic polycarbonate composition which is stabilized with an epoxy compound and a phosphinite, which phosphinite has the general following formula: ##EQU1## Preferably, the phosphinite is ethyl diphenyl phosphinite.

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Mt. Vernon, IN, United States of America

Frank N Liberti