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:
May. 17, 1983
Filed:
Sep. 08, 1981
James A Hyde, Downers Grove, IL (US);
Michael D Breslin, Downers Grove, IL (US);
David R Cosper, Downers Grove, IL (US);
Roy I Kaplan, Naperville, IL (US);
Nalco Chemical Company, Oak Brook, IL (US);
Abstract
The present invention provdes an additive for reducing brightness loss upon pulp refining comprising in combination at least one anionic polymeric compound and at least one inorganic polymer, preferably such combinations wherein any of such anionic polymeric compounds are of low molecular weight. The preferred inorganic polyphosphates of such combination are those having average polymerization numbers of from about 10 to about 45. The weight proportion of inorganic polyphos-hate to anionic polymeric compound in such combination can be within the range of about 1:10::10:1. The present invention also provides pulp refining processes wherein such additive is added at a sufficient amount to the pulp material being refined to reduce brightness loss, such as at dosages of from about 0.0025 to about 0.5 weight percent additive actives to dry pulp, and end product pulps produced by such processes.