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:
Jul. 24, 1979
Filed:
Feb. 23, 1978
Donald C Wood, Des Plaines, IL (US);
Robert L McLaughlin, Wilmette, IL (US);
DeSoto, Inc., Des Plaines, IL (US);
Abstract
A de-inking process for removing ink and other substances from printed paper which process is capable of providing de-inked paper stock having improved brightness. The process utilizes an aqueous de-inking solution containing a mixture of certain surfactants, at least one surfactant being a water-soluble nonionic surfactant and the other surfactant being an oil-soluble nonionic surfactant. De-inking is carried out at a temperature in the range of about room temperature to about the boiling temperature of the solution by forming a slurry of the printed paper in the solution having a predetermined fibrous material solids content. The total nonionic surfactant concentration in the de-inking solution can be about 0.1 to about 5 weight percent, preferably about 0.5 to about 2.5 weight percent, based on the amount of fibrous material solids present. The weight ratio of the water-soluble surfactant to the oil-soluble surfactant in the mixture is in a range of about 6:1 to about 3:1, preferably about 4:1.