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:
Aug. 16, 1988
Filed:
Jun. 15, 1987
Peter Dilling, Isle of Palms, SC (US);
Westvaco Corporation, New York, NY (US);
Abstract
An improved method of producing methylolated lignins from the black liquor residue of a kraft wood-pulping process, which methylolated lignins may be further employed in other chemical reactions, such as in the production of sulfomethylated lignin salts suited for use as dyestuff dispersants, comprising the steps of oxidizing the black liquor residue of a kraft wood-pulping process containing lignin, organic, and inorganic salts, treating the black liquor residue with an aldehyde to methylolate the lignin therein, lowering the pH of the black liquor residue to precipitate the lignin therefrom, and isolating and recovering the methylolated lignin for subsequent chemical reactions. The black liquor residue of the kraft pulping process is oxidized, before methylolation of the lignin therein, to reduce the presence of sodium sufide in the black liquor residue to about 1 percent or less.