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:
Aug. 23, 1994
Filed:
Apr. 01, 1993
Bhaskar B Idage, Pune, IN;
Nayaku N Chavan, Pune, IN;
Sudhakar S Mahajan, Pune, IN;
Swaminathan Sivaram, Pune, IN;
Council of Scientific & Industrial Research, New Delhi, IN;
Abstract
This invention relates to a process for the preparation of aromatic polyester(s) having an intrinsic viscosity greater than 0.4 dL/g in chloroform at 30.degree. C. which comprises (a) reacting diarylesters of tere and isophthalic acid(s) and dihydric phenol(s) in the melt phase in an inert atmosphere in the presence of a catalyst selected from alkoxides of Group IV B metals and derivatives of Group IV A metals and in the presence of an organic solvent at a temperature in the range of 100.degree.-300.degree. C. to form a prepolymer having intrinsic viscosity in the range of 0.1 to 0.3 dL/g in chloroform at 30.degree. C. (b) purifying the prepolymer using conventional solvent extraction methods and (c) Polycondensing the purified prepolymer at a temperature in the range of 300.degree.-350.degree. C. in presence of a catalyst selected from alkoxides of Group IVB metals and derivatives of Group IVA metals under reduced pressure.