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:
Oct. 25, 2011
Filed:
Mar. 21, 2008
Chie Yuzawa, Tokyo, JP;
Hisashi Iwabuchi, Tokyo, JP;
Yasuyuki Kamijo, Tokyo, JP;
Shisei Goto, Tokyo, JP;
Takeshi Iimori, Tokyo, JP;
Chie Yuzawa, Tokyo, JP;
Hisashi Iwabuchi, Tokyo, JP;
Yasuyuki Kamijo, Tokyo, JP;
Shisei Goto, Tokyo, JP;
Takeshi Iimori, Tokyo, JP;
Nippon Paper Industries Co., Ltd., Tokyo, JP;
Abstract
The object of the present invention is to provide a process for producing deinked pulp from recovered paper containing stickies while preventing excessive reduction in the size of stickies, lowering the COD of effluents, and producing deinked pulp with a smaller residual ink content. In the ink detachment stage of the process for producing deinked pulp from recovered paper containing stickies, an anhydride of crystalline layered silicate is added, preferably in an amount of 0.1-1.5 weight % of absolute-dry pulp, and a deinking treatment is performed at a pH of 7.0-9.9. In the present invention, the deinking treatment is performed in a weakly alkaline to neutral region which is generally said to be effective in reducing the amount of stickies but less effective in ink detachment and, yet, deinked pulp having a smaller amount of residual ink can be produced.