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. 16, 1979
Filed:
May. 26, 1978
Robert C Eckert, Kent, WA (US);
International Paper Company, New York, NY (US);
Abstract
A process for the delignification of a lignocellulosic material, which comprises the steps of: (a) digesting the lignocellulosic material with an aqueous, alkaline pulping liquor containing from about 0.1% to about 10% based on the weight of oven-dried lignocellulosic material, of a cyclic amino compound selected from the group consisting of phenazine, dihydrophenazine, quinoxaline, and their alkyl, alkoxy, hydroxy, carboxy and amino derivatives at a temperature of from about 150.degree. C. to about 200.degree. C. for a period of from about 5 to about 480 minutes; and then (b) removing the aqueous pulping liquor from the lignocellulosic material with water or an aqueous wash liquor inert to the lignocellulosic material to obtain a delignified cellulosic material.