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. 28, 1995
Filed:
Oct. 13, 1993
Joseph A Schomaker, Midland, MI (US);
Jerry E White, Midland, MI (US);
Anthony P Haag, Midland, MI (US);
Ha Q Pham, Lake Jackson, TX (US);
The Dow Chemical Company, Midland, MI (US);
Abstract
Poly(hydroxy ethers) are prepared by reacting a dihydric phenol with a diepoxide in the presence of a catalyst selected from the group consisting of bis(trihydrocarbylphosphoranylidene)ammonium salt, bis[tris(dihydrocarbylamino)phosphoranylidene]ammonium salt, and tetrakis[tris(dihydrocarbylamino)phosphoranylideneamino]phosphonium salt. The reaction between the dihydric phenol and the diepoxide is conducted in an ether or hydroxy ether solvent at a temperature sufficiently high to produce a poly(hydroxy ether). Polymers prepared by the new process are more highly branched than those produced by known methods.