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. 31, 1978
Filed:
Aug. 19, 1976
Norman W Thomas, Warren, NJ (US);
Frank M Berardinelli, Millington, NJ (US);
Robert Edelman, Staten Island, NY (US);
Celanese Corporation, New York, NY (US);
Abstract
There is disclosed a process for preparing polycarbodiimide modified thermoplastic polyesters having unique rheological properties which include increased intrinsic viscosity and melt strength. These polycarbodiimide modified thermoplastic polyesters are prepared by reacting the carboxyl end groups of thermoplastic saturated polyesters which are in a molten state with the polycarbodiimide groups of at least one polycarbodiimide such as poly (4,4'-diphenyl-methane carbodiimide) which both (a) is derived from at least one aromatic diisocyanate which is either unsubstituted or contains up to one methyl substituent on each aromatic ring, and (b) contains at least three carbodiimide units per polycarbodiimide molecule. The resulting polycarbodiimide modified thermoplastic polyester has improved melt strength and intrinsic viscosity and a decreased number of carboxylic acid end groups. These improved melt strength polyesters also have improved die swell and shear sensitivity characteristics and are generally useful in extrusion applications such as blow molding.