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:
Jun. 08, 1993
Filed:
Apr. 23, 1992
Ted Y Tsai, Harriman, NY (US);
Long S Wang, New City, NY (US);
International Paper Company, Purchase, NY (US);
Abstract
A method for removing laser printer and xerographic toner, ink or the like from paper to be recycled comprising pulping the paper to be recycled with water to produce a paper pulp slurry with a consistency of between about 1% and 20%, adjusting the pH of the slurry to between about 6 and about 13, adding between about 0.3 and about 5.0 wt. %, based on the dry weight of the paper, of a surfactant to the slurry, the surfactant having the formula R.sup.1 --R.sup.2 --R.sup.3, wherein R.sup.1 and R.sup.3 are each selected from the group consisting of rosins, rosin dimers and mixtures of rosins and rosin dimers and R.sup.2 is a polyethylene glycol (PEG) having a molecular weight of between about 220 and about 660 Da, and adding between about 0.01 and about 5.0 wt. % of polyacrylic acid to the slurry, maintaining the slurry at a temperature of between about 30.degree. C. and about 120.degree. C. for a period of between about 5 minutes and about 90 minutes, and removing the ink from fibers of the paper as agglomerated particles, the particles having diameters of between about 1 mm and about 3 mm.