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. 08, 1980
Filed:
Oct. 26, 1973
Applicant:
Inventors:
Louis A Pradt, Wausau, WI (US);
William M Copa, Wausau, WI (US);
Assignee:
Sterling Drug Inc., New York, NY (US);
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
D21C / ;
U.S. Cl.
CPC ...
162 38 ; 162 58 ; 162 65 ; 162 90 ;
Abstract
An improvement in the delignification (pulping) of raw cellulose by treatment with oxygen and an alkaline buffer solution at elevated temperature and pressure, which comprises carrying out the process in an unflooded condition, that is, where contact between the raw cellulose and buffer solution is intermittent, both gaseous and liquid phases being present at all times. Optionally, cupric ion may be present as a catalyst.