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:
Feb. 24, 1981
Filed:
Mar. 09, 1979
Applicant:
Inventors:
Hershel B Prindle, Lake Jackson, TX (US);
George E Ham, Lake Jackson, TX (US);
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C07D / ;
U.S. Cl.
CPC ...
2603434 ;
Abstract
A process for the preparation of phenol-phthalein wherein phenol and phthalic anhydride are reacted in the presence of a crosslinked sulfonic cation exchange resin in the acid form and wherein the water content of the reaction mixture is reduced by the use of aryl phosphites. The sulfonic cation exchange resin can be in the macroporous form or in the gel form. The range of useful crosslinking is 4-40 percent for the macroporous resin and 2-16 percent for the gel resin.