Solvent sweeping of polycarbonates
AssigneeGeneral Electric Company
InventorsHenry P. Barker, Gary S. Motz, Donald L. Phipps, Phillip S. Wilson
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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.
Claims29
A process for preparing an extrusion molded polycarbonate product which comprises
- (a) adding to a polycarbonate molding powder 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;
- (b) subjecting the molding composition, including the volatile matter entraining agent, to an extrusion molding operation;
- (c) removing the volatilized entraining agent and impurities which are evolved during the molding operation;
- and
- (d) obtaining a molded product which is substantially free from volatile impurities.
A process for preparing an extrusion molded polycarbonate product which is substantially free from volatile impurities which comprises adding to a polycarbonate molding powder 1,2-propanediol in an amount from about 0.1 to about 5% by weight prior to the extrusion thereof.
A process for preparing an extrusion molded polycarbonate product which is substantially free from volatile impurities which comprises adding to a polycarbonate molding composition 1,2-propanediol in an amount from about 0.1 to about 5% by weight during the extrusion thereof.
A process for preparing an extrusion molded polycarbonate product which is substantially free from volatile impurities which comprises adding to a polycarbonate molding powder a solution of 1,2-propanediol in water in an amount from about 0.1 to about 5% by weight prior to the extrusion thereof.
A process for preparing an extrusion molded polycarbonate product which is substantially free from volatile impurities which comprises adding to a polycarbonate molding composition a solution of 1,2-propanediol in water in an amount from about 0.1 to about 5% by weight during the extrusion thereof.
Dependencies are inferred from the claim text.