Patent · US Expired

Process of producing polytrimethylene terephthalate (PTT)

US6326456A · kind A · utility

14Cited by

7References

6Claims

0Family size

Assignee

SHELL OIL COMPNY · US

Inventors

Donald R. Kelsey · Brookshire, US
Robert Lawrence Blackbourn · Houston, US
Robert Stephen Tomaskovic · Richmond, US
Hans Reitz · Rosbach, DE
Eckhard Seidel · Frankfurt, DE
Fritz Wilhelm · Karben, DE

Key dates

Filing date	May 18, 2001
Grant date	Dec 4, 2001
Priority date	—
Expiry date	May 18, 2021

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08G63/183
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

Process of producing polytrimethylene terephthalate (PTT) by esterification of terephthalic acid (TPA) with trimethylene glycol (TMG) in the presence of a catalytic titanium compound, precondensation and polycondensation. The sterification is effected in at least two stages, where in the first stage a molar ratio of TMG to TPA of 1.15 to 2.5, a content of titanium of 0 to 40 ppm, a temperature of 240 to 275.degree. C., and a pressure of 1 to 3.5 bar are used. In the at least one subsequent stage a content of titanium is adjusted which is higher than in the initial stage by 35 to 110 ppm.

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