Patent · US Expired

Method for extruder devolatilization of spiro(bis)indane polycarbonates

US4980105A · kind A · utility

9Cited by

8References

12Claims

0Family size

Assignee

General Electric Company · US

Inventors

Lawrence R. Schmidt · Schenectady, US
Joel Caraher · Delanson, US
John Lester Maxam · Saratoga Springs, US

Key dates

Filing date	Aug 28, 1989
Grant date	Dec 25, 1990
Priority date	—
Expiry date	Aug 28, 2009

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB29C48/03
WIPO fieldOther special machines
WIPO sectorMechanical engineering

Abstract

Spiro(bis)indane polycarbonates, including homo- and copolycarbonates, are devolatilized by extrusion under conditions of low viscous dissipation and low residence time. By this method, volatile impurities including spiro(bis)indane cyclic dimer may be removed.

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