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. 09, 1990
Filed:
Oct. 24, 1988
Peter Dilling, Isle of Palms, SC (US);
Gerald Prazak, Charleston, SC (US);
Catherine C Cashman, Hanahan, SC (US);
Westvaco Corporation, New York, NY (US);
Abstract
A carbon black composition comprising carbon black and a lignin dispersant prepared by the steps of methylolating a lignin compound by reaction of less than about 2 moles formaldehyde per 1,000 grams of the lignin, and sulfonating the methylolated lignin by reaction from about 2.5 to 3.5 moles of the sulfite or bisulfite compound per 1,000 grams of lignin at an initial reaction pH of below about 6.6 and at a temperature of at least about 170.degree. C., while allowing the pH of the reaction mixture to rise to a final pH of greater than 7.5 to sequentially sulfomethylate the aromatic nucleus and sulfonate the side chain of the lignin.