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:
Jan. 13, 1976
Filed:
Feb. 15, 1974
Gunter Zoche, Bonn-Beuel, DT;
Hermann Richtzenhain, Post Marialinden, DT;
Roshdy Ismail, Neunkirchen, DT;
Dynamit Nobel Aktiengesellschaft, Troisdorf, DT;
Abstract
Process for the preparation of especially pure 2,2-bis-(4-hydroxy-3-chlorophenyl)-propane (dichlordiane, DCD) by the chlorination of 2,2-bis-(4-hydroxyphenyl)-propane in the presence of solvents that are substantially indifferent to chlorine by prior-art methods; then, for purification, the chlorinated bis-phenol is dissolved in halogenated hydrocarbons and/or halogenated hydrocarbon in which are liquid at 20.degree.C which they are readily soluble in the absence of an aqueous phase but in which they are at most only slightly soluble after the addition of water thereto; and the 2,2-bis-(4-hydroxy-3-chlorophenyl)-propane, is thereby precipitated from this aqueous solution.