Allied Chemical Corporation

Phillip S Bollen

William Sacks

Surendra A Amin

A sheet formed from a uniform blend of from about 80 to 97% by weight of polyethylene terephthalate having an intrinsic viscosity of above about 0.9 and a melt viscosity at 525.degree. F. of above about 10,000 poises and correspondingly from about 20 to 3% by weight of a polycarbonate resin having an intrinsic viscosity of about 0.4 to 0.6 and a melt viscosity at 500.degree. F. of less than 50,000 poises; said sheet having a haze value as determined by ASTM D-1003 of less than about 2% and being essentially amorphous and non-oriented. Also disclosed is a process for forming a sheet which comprises uniformly blending the composition, extruding the composition into a sheet at a temperature between about 490.degree. to 530.degree. F. and rapidly cooling the sheet by contact with at least one cooling surface maintained at a surface temperature in the range of about 50.degree. to 160.degree. F. for a period of time not exceeding about 15 seconds. Containers may be formed from such sheets by a thermoforming step at temperatures in the range of about 210.degree. to 280.degree. F.

Transparent sheets and containers formed from polycarbonate-polyester

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 polymer having an intrinsic viscosity of at least about 0.90 and correspondingly about 40 to 15 parts by weight of a polycarbonate polymer, the polyethylene terephthalate portion of the film or sheet having a degree of crystallinity in the range of about 20 to 40%. The film is essentially non-oriented. The present invention also provides shaped articles thermoformed from such film or sheet, such as cook-in-trays. Moreover, this invention provides a process of forming such film or sheet which comprises the steps of blending about 60 to 85 parts by weight of a polyethylene terephthalate polymer having an intrinsic viscosity of at least about 0.90 with correspondingly about 40 to 15 parts by weight of a polycarbonate resin, extruding the resultant blend at a temperature of above about 500.degree.F onto a moving support such as a casting roll while maintaining the surface of the support at a temperature of about 225.degree. to 380.degree.F whereby a film or sheet of the blend is formed, and collecting the thus formed film or sheet.

Growing community of inventors

Auburn, PA, United States of America

Phillip S Bollen