Allied Chemical Corporation

Philip Stuart Bollen

Surendra A Amin

Alfieri Degrassi

Paul W Berger

Eugene Vincent Walacavage

Physically blending small amounts of polycarbonate resin into polyethylene terephthalate resin which is to be extruded and cooled to form an unoriented amorphous sheet reduces deposits of terephthalic acid on the cooling rolls during sheet extrusion.

Method to reduce deposits of terephthalic acid on cooling rolls during

This invention provides a film or sheet capable of being thermoformed into a shaped article and being formed from a blend of about 60 to 85 parts by weight of a polyethylene terephthalate having an intrinsic viscosity of at least about 0.90, about 15 to 40 parts by weight of a polycarbonate and about 5 to 20 parts by weight of a non-acidic silica filler, such as novaculite, the polyethylene terephthalate portion of the film or sheet having a degree of crystallinity in the range of about 20 to 40%. The present invention also provides compositions for forming such films and sheets and shaped articles thermoformed from such films or sheets, such as cook-in-trays. This invention also provides a process of forming such films or sheets.

Production of films and sheets of polyester-polycarbonate blends

A polyester sheet containing an antiblock agent is produced by uniformly blending a small amount of a degraded polycarbonate containing the antiblock agent. The antiblock agent must have an inherent or adjusted pH of less than six to degrade the polycarbonate to lower its molecular weight upon extrusion compounding. This in turn makes a uniform blend and resulting clear sheet with antiblocking properties. In another embodiment, larger amounts of polycarbonate containing the antiblock agent are used.

Polyester sheet containing antiblock agent added in degradable

In accordance with the present invention, films of a nylon 6-nylon 6,6 blend are produced by a process which comprises blending about 50 to about 80 percent by weight nylon 6 resin and correspondingly about 50 to about 20 percent by weight nylon 6,6 resin, extruding said blend at a temperature above its melting point onto a smooth moving support to form a coherent film; maintaining said support at a surface temperature in the range of about 230.degree. to about 300.degree. F. and collecting the resultant film. The resultant film has a haze value, as hereinafter defined, in the range of about 5 to about 20 percent, preferably about 8 to about 14 percent. Film having the latter range of haze values is particularly suitable for the production of cooking bags.

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Auburn, PA, United States of America

Philip Stuart Bollen