Patent · US Expired

Preparation of polyvinyl alcohol

US6576720B2 · kind B2 · utility

0Cited by

6References

11Claims

0Family size

Assignee

WACKER POLYMER SYSTEMS GMBH & CO. KG · DE

Inventors

Werner Bauer · Neuötting, DE
Peter Ball · Emmerting, DE
Peter Tschirner · Emmerting, DE

Key dates

Filing date	Feb 7, 2002
Grant date	Jun 10, 2003
Priority date	—
Expiry date	Feb 7, 2022

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC08F8/12
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

A process for preparing polyvinyl alcohol by means of catalytic transesterification of an alcoholic polyvinyl ester solution and subsequent workup by means of isolation of the polyvinyl alcohol formed includes adding, prior to the transesterification of the polyvinyl ester solution, the acetic ester of the alcohol used as solvent, in an amount of from 5 to 70% by weight, based on the overall amount of alcoholic solvent and its acetic ester, and recycling the liquid phase obtained after isolation of the polyvinyl alcohol product to a further polyvinyl ester transesterification.

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