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:
May. 21, 1985
Filed:
Feb. 03, 1984
Alberto Greco, Milan, IT;
Guglielmo Bertolini, Pavia, IT;
Enichimica Secondaria, S.p.A., Palermo, IT;
Abstract
For preparing polyoxyalkylenediol-.alpha.,.omega.-bisallyl policarbonates, diallyl carbonate is reacted in a first reaction stage with a polyoxyalkylenediol having a mol wt between 400 and 4500 in the presence of a transesterification catalyst at a temperature in the neighborhood of 100.degree. C. and under reduced pressures, whereafter, in a second reaction stage, the product as obtained from the first stage is treated at a temperature between 70.degree. C. and 150.degree. C. under reduced pressures, still in the presence of a transesterification catalyst. By so doing, the chain extension of the bisallyl carbonate of the polyoxyalkylenediol is achieved, whereas the unreacted diallyl carbonate coming from the first stage, and that produced in the second stage, are eliminated, and the final reaction product can thus be collected.