Patent · US Expired

Process for improving the drawing ability of polyester

US6066713A · kind A · utility

15Cited by

10References

6Claims

0Family size

Assignee

Lurgi Zimmer GmbH · DE

Inventors

Werner Mrose · Maintal, DE
Ulrich Thiele · Bruchköbel, DE

Key dates

Filing date	Feb 18, 1997
Grant date	May 23, 2000
Priority date	—
Expiry date	Feb 18, 2017

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB29B2009/165
WIPO fieldOther special machines
WIPO sectorMechanical engineering

Abstract

A process for the improvement of the drawing ability of polyester, pellets of which are thermally post-treated in the solid phase in an inert atmosphere, containing a precise concentration of water vapor. The water vapor concentration is equal to the amount of water, plus 15%/minus 50%, which could theoretically be formed, at the polyester end viscosity, from the --COOH end groups and the excess --OH end groups of the polyester. An equimolar quantity of the vapor of the alkanediol, which serves as the diol reactant for the polyester, may be substituted for all or part of the water vapor.

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