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:
Sep. 06, 1977
Filed:
Sep. 12, 1975
Applicant:
Inventor:
John H Kozlowski, Vancouver, WA (US);
Assignee:
Crown Zellerbach Corporation, San Francisco, CA (US);
Attorneys:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07C / ;
U.S. Cl.
CPC ...
2605 / ; 106 / ; 210 59 ; 260D / ;
Abstract
When 4,4'-dihydroxydiphenyl sulfone is sulfonated to form 3,3'-sulfonylbis(6-hydroxybenzene sulfonic acid), the product can be recovered from the reaction mixture by adding methanol or ethanol and a base to the reaction mixture to selectively precipitate only the disalt of the product. Particularly good results are obtained using sulfolane as a solvent in the sulfonation reaction. The product is useful as a flame retardant additive in polymers and other materials, and is also useful as an additive in boiler water to remove or prevent formation of scale.