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. 14, 1992
Filed:
Oct. 19, 1990
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C09C / ;
U.S. Cl.
CPC ...
552262 ;
Abstract
1-Hydroxyanthraquinones are prepared in an improved process by reacting phthalic anhydride or derivatives thereof with phenol derivatives in the presence of a Lewis acid as catalyst and in the presence or absence of a diluent, wherein the improvement comprises conducting the reaction in a self-cleaning apparatus having a mixing effect, at a temperature of from 120.degree. C. to 300.degree. C. for from 5 to 1,000 seconds, the self-cleaning apparatus having a mixing effect subjecting the reactants to a shear gradient of from 50 to 20,000 sec.sup.-1 with an energy input of from 0.01 to 0.2 kwh/kg of reactants.