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:
Feb. 19, 1991
Filed:
Mar. 28, 1989
Michael J Mullins, Midland, MI (US);
Steven P Crain, Midland, MI (US);
Edmund P Woo, Midland, MI (US);
Daniel J Murray, Midland, MI (US);
Stephen E Bales, Midland, MI (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
A method for preparing novel poly(aryl ether)-(poly aryl carbonate) block copolymers by the decarboxylation of copolycarbonates prepared by the condensation of two different aromatic dihydroxy compounds and a carbonate precursor such as phosgene. At least one of the aromatic diols must have at least one electron-withdrawing group located in a position ortho or para to at least one of its hydroxy groups and at least one of the diols must not have any electron-withdrawing groups in a position ortho or para to either of its hydroxy groups. The method is particularly effective in making crystalline block copolymers.