Patent · US Expired

Process for production of polyester polymer for food packing

US4263425A · kind A · utility

19Cited by

9References

3Claims

0Family size

Assignee

Zimmer, Inc. · US

Inventors

Hans-Jochen Rothe · Maintal, DE
Peter C. Freund · Ketsch, DE
Werner Gey · Offenbach am Main, DE
Helmut Heinze · Frankfurt am Main, DE

Key dates

Filing date	Nov 8, 1978
Grant date	Apr 21, 1981
Priority date	—
Expiry date	Nov 8, 1998

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08G63/90
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

Polyethylene terephthalate having an acetaldehyde content of less than 2.5 ppm and suitable for packing of food and beverages intended for human consumption is produced by heating polyethylene terephthalate having an intrinsic viscosity of about 0.5--0.85 at a temperature of 180.degree.-230.degree. C., preferably 200.degree.-220.degree. C., for about 4 to 12 hours. The polyethylene terephthalate must not include more than 25 ppm of ester interchange catalyst or 20 ppm of phosphorous during this heating.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.