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:
Dec. 15, 1998
Filed:
Sep. 03, 1997
Nipun Marwah, Mt. Pleasant, SC (US);
G Frederick Hutter, Charleston, SC (US);
Westvaco Corporation, New York, NY (US);
Abstract
An improved process is disclosed for deinking waste paper which contains nonimpact printed papers printed with xerographic and laser inks by repulping the waste paper to form a slurry in the presence of an agglomeration agent and magnetite and subjecting the slurry to a magnetic field to remove the agglomerated ink particles, whereby the improvement comprises replacement of a portion of the agglomeration agent with a copolymer of styrene and acrylic monomers which copolymer is further characterized by having a Ring and Ball softening point of 70.degree.-105.degree. C. and an number average molecular weight of 2,000 to 10,000. The magnetic treatment preferably is conducted at ambient or greater temperature, at neutral to alkaline pH, and at a low pulp consistency. Also, the process may be employed as an additional step in a conventional process for removing inks from reprographic printed papers, such as ink removal by screening, flotation, centrifugal cleaning, washing, and sedimentation with or without decantation.