Patent · US Active

Process for making polyethylene terephthalate

US8859713B2 · kind B2 · utility

1Cited by

11References

18Claims

0Family size

Assignee

SAUDI BASIC INDUSTRIES CORPORATION · SA

Inventors

Mummaneni Venkateswara Rao · Riyadh, SA
Munif Al-Munif · Riyadh, SA
Zahir Bashir · Riyadh, SA

Key dates

Filing date	Mar 10, 2010
Grant date	Oct 14, 2014
Priority date	—
Expiry date	Mar 10, 2030

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08G63/866
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

The invention relates to a process for making polyethylene terephthalate (PET) from ethylene glycol (EG), purified terephthalic acid (PTA) and optionally up to 30 mol % comonomer, using a catalyst system essentially consisting of antimony—(Sb), zinc—(Zn) and phosphorous—(P) compounds, comprising the steps of a) esterifying EG and PTA to form diethyleneglycol terephthalate and oligomers (DGT), and b) melt-phase polycondensing DGT to form polyester and EG1 wherein the Sb- and P-compounds are added in step a) and the Zn-compound is added after step a). With this process PET can be obtained that shows favorable color and optical clarity, also if recycling of EG is applied in the process, and a relatively low rate of acetaldehyde regeneration during melt-processing.

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