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:
Jan. 02, 1979
Filed:
Jul. 28, 1977
Robert W Stackman, Morristown, NJ (US);
Arnold J Rosenthal, Whippany, NJ (US);
Marvin L Sakowitz, East Brunswick, NJ (US);
Celanese Corporation, New York, NY (US);
Abstract
A process for preparing certain halogenated aromatic polyesters having a predetermined molecular weight is provided. Such polyesters are prepared by solution polymerization of an appropriate bisphenol and diacid halide wherein the diacid halide is added to a solution containing the bisphenol until the viscosity of the resulting polymer containing solution reaches a predetermined solution viscosity limit at which time the further addition of diacid halide is terminated. The solution viscosity limit is indicative of the attainment of said predetermined molecular weight. The identification of said solution viscosity limit is achieved by a feedback mechanism wherein the viscosity of the polymer containing solution is monitored or sensed during or after the addition of the diacid halide to the bisphenol containing solution.