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. 23, 1976
Filed:
Dec. 26, 1974
Nissan Chemical Industries, Ltd., Tokyo, JA;
Abstract
An improvement is disclosed in a process for preparing a polyphosphonate which comprises polycondensing an aromatic diol having the formula (I) - (IV) ##SPC1## wherein Z represents chlorine or bromine atom or a lower alkyl group and m represents 0 or an integer of from 1 to 4 and n represents 0 or an integer of from 1 to 3; Y represents an alkylene group, cycloalkylene group, sulfonyl group, carbonyl group or oxygen atom; with a dihalide or arylphosphonic or thiophosphonic acid having the formula (V) ##SPC2## wherein A represents oxygen or sulfur atom; X represents chlorine or bromine atom; Z represents chlorine or bromine atom or a lower alkyl group; and 1 represents 0 or an integer of from 1 to 5, wherein the improvement comprises maintaining a solution of the polyphosphonate at a temperature such that solid polyphosphonate is produced after flashing; and then evaporating all or a part of the solvent from the solution by flashing whereby a porous solid polyphosphonate is formed.