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:
Mar. 26, 1985
Filed:
May. 01, 1984
Ivan Orban, Basel, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
A novel process for producing compounds of the formula I ##STR1## by polycondensation of a diol of the formula II ##STR2## with a dicarboxylic acid ester of the formula III ##STR3## R.sub.1 and R.sub.2 are independently alkylene or alkenylene, R.sub.3 is lower alkyl and n is 18 to 25. The process according to the invention is characterized in that the reaction medium is treated, in the presence of at least 0.05 mol %, relative to the diol of the formula II, of an organometallic compound of titanium or tin, at a maximum steam temperature of 75.degree. C., until the formed methanol has been almost completely distilled off; distillation is then continued for at least 3 hours, during which time the volume of the reaction solution is kept approximately constant by successive additions of solvent, at a steam temperature of between 100.degree. and 145.degree. C.; the reaction solution is subsequently concentrated by evaporation, and the melt which remains is finally ground after it has solidified. There are thus surprisingly obtained, in practically quantitative yield, polyesters of the formula I having a mean molecular weight Mn of at least 5000.