The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 29, 1986
Filed:
Nov. 20, 1984
Jhy-Dou R Lo, Cupertino, CA (US);
William R Schlich, Pittsfield, MA (US);
General Electric Company, Pittsfield, MA (US);
Abstract
The present invention concerns a two-step extrusion melt polymerization process for making polyetherimides. The first step of the process involves producing a low molecular weight polymer by melt polymerizing a mixture containing a molar excess of one of the monomers. The second step involves melt polymerizing a mixture containing the low molecular weight polymer produced by the first step and a stoichiometrically sufficient amount of the second monomer to produce the desired polyetherimide polymer. Polymerization in two stages, rather than by the conventional one stage process surprisingly results in reduced extruder torque levels and improved throughput rates.