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. 31, 1982
Filed:
May. 21, 1981
Albert Brucato, Seattle, WA (US);
The Chemithon Corporation, Seattle, WA (US);
Abstract
An additive comprising an anionic organic surface active agent is incorporated into mechanical or thermomechanical pulp at an elevated temperature and pressure. The additive causes dispersion of lignin and retards redeposition of lignin so that the bursting strength of the paper formed from the pulp is improved. The preferred additives are higher molecular weight anionic organic polyelectrolytes or polymers, particularly polymeric sulfonates. Further improvement in bursting strength is achieved by the wet end addition of a cationic organic polyelectrolyte or polymer, with or without starch. Lower molecular weight anionic organic detergents can also be used but should be rinsed from the pulp before forming paper.