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:
Dec. 22, 1981
Filed:
Jun. 25, 1980
Thomas H Schwab, North Brunswick, NJ (US);
Wong F Ark, Bridgewater, NJ (US);
Robert A Clendinning, New Providence, NJ (US);
Union Carbide Corporation, New York, NY (US);
Abstract
Described herein is an improved process for preparing polyarylene polyethers by (a) converting a dihydric phenol to the alkali metal phenolate by adding an alkali metal or alkali metal compound to the phenol in a mixture of a sulfone or sulfoxide solvent and a solvent which forms an azeotrope with water, (b) removing water by codistillation with the azeotrope forming cosolvent, and (c) reacting the phenolate mixture with a dihalobenzeneoid compound, wherein a lighter colored product is obtained by adding the sulfone or sulfoxide solvent in increments. This may be accompanied by (1) adding an increment of the sulfone or sulfoxide solvent to a mixture of the dihydric phenol in the codistillation solvent and adding the remaining portion during the azeotroping step, or (2) adding an increment of the sulfone or sulfoxide solvent to the mixture of dihydric phenol and codistillation solvent and the remaining portion to the system simultaneously with the alkali metal hydroxide or other phenolate forming alkali metal source, or (3) adding a first increment of the sulfone or sulfoxide to the dihydric phenol-azeotrope forming solvent prior to step (a), a second increment simultaneously with the addition of alkali metal source in step (a), and the remainder during or at the end of azeotroping step (b).