Patent · US Expired

Preparation of linear high molecular weight saturated polyesters

US4248996A · kind A · utility

3Cited by

1References

6Claims

0Family size

Assignee

BASF SE

Inventors

Hans-Josef Sterzel · Schifferstadt, DE
Franz Schmidt · Mannheim, DE
Hans Pirzer · Bischofswerda, DE

Key dates

Filing date	Feb 28, 1979
Grant date	Feb 3, 1981
Priority date	—
Expiry date	Feb 28, 1999

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08G63/78
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

A process for the preparation of high molecular weight linear saturated polyesters derived from dicarboxylic acids or their ester-forming derivatives and aliphatic and/or cycloaliphatic diols, comprising the condensation of polyester precondensates having a relative viscosity of from 1.05 to 1.15 at from 220.degree. to 280.degree. C. under reduced pressure, wherein PA1 (a) the condensation is first started with from 70 to 95 percent by weight of the polyester precondensate and PA1 (b) after from 10 to 50% of the total condensation time the remaining 5 to 30 percent by weight of the polyester precondensate are added to the polyester melt undergoing condensation in accordance with (a), and the condensation is taken to completion.

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