Paper making and fiber liberation – Processes of chemical liberation – recovery or purification... – Gas – vapor or mist contact
Reexamination Certificate
2011-07-12
2011-07-12
Daniels, Matthew J (Department: 1741)
Paper making and fiber liberation
Processes of chemical liberation, recovery or purification...
Gas, vapor or mist contact
C162S009000, C162S074000
Reexamination Certificate
active
07976676
ABSTRACT:
This invention relates to an improved bleaching process for bleaching pulp comprising at least one bleaching stage which comprises treating a softwood pulp with a bleaching agent comprising ClO2in the presence of a weak base such as, for example, Mg(OH)2preferably at pH from about 3.5 to about 6.5. The invention is also relates a bleaching process for bleaching pulp having two or more bleaching stages, at least one of which and preferably two of which comprises treating a softwood pulp with a bleaching agent comprising ClO2in the presence of a weak base such as, for example, Mg(OH)2preferably at pH from about 3.5 to about 6.5.
REFERENCES:
patent: 2639987 (1953-05-01), Sloman
patent: 3657065 (1972-04-01), Smith et al.
patent: RE28777 (1976-04-01), Wilder
patent: 4859283 (1989-08-01), Jayawant
patent: 5091054 (1992-02-01), Meier et al.
patent: 5179021 (1993-01-01), du Manoir et al.
patent: 5441603 (1995-08-01), Griggs et al.
patent: 5641385 (1997-06-01), Croft et al.
patent: 5681427 (1997-10-01), Lora et al.
patent: 5902454 (1999-05-01), Nelson
patent: 6056853 (2000-05-01), Vincent et al.
patent: 6235154 (2001-05-01), Jiang et al.
patent: 6245196 (2001-06-01), Martin et al.
patent: 6258208 (2001-07-01), Lindeberg et al.
patent: 6398908 (2002-06-01), Hermansson et al.
patent: 6464832 (2002-10-01), Engelhardt et al.
patent: 6569284 (2003-05-01), Yin et al.
patent: 2001/0050153 (2001-12-01), Wajer et al.
patent: 2002/0189021 (2002-12-01), Haynes et al.
patent: 2003/0145961 (2003-08-01), Rousu et al.
patent: 2004/0112555 (2004-06-01), Tolan et al.
patent: 2004/0112557 (2004-06-01), Parrish et al.
patent: 2004/0149404 (2004-08-01), Snekkenes et al.
patent: 2007/0079944 (2007-04-01), Amidon et al.
patent: 756967 (1967-04-01), None
patent: 0716182 (1995-11-01), None
patent: 815247 (1959-06-01), None
patent: 1505076 (1978-03-01), None
patent: 2004124265 (2004-04-01), None
patent: WO 88/01661 (1988-03-01), None
patent: WO 02/075046 (2002-09-01), None
patent: WO 03/074780 (2003-09-01), None
patent: WO 2004/079087 (2004-09-01), None
patent: WO 2006/121634 (2006-11-01), None
Environmental Defense Fund et al., Economics of Kraft Pulping and Bleaching, 1995, Paper Task Force, p. 49-51.
Martin Marietta Materials, Martin Marietta Magnesia Specialties [downloaded online from: www.magnesiaspecialties.com], 2008 [downloaded online Sep. 3, 2009], whole document.
English Machine Translation of JP 2004124265A, Apr. 2004.
Gullichsen et al., Chemical Pulping 6A, 1999, Fapet Oy, p. A616-A665.
Kolar, Chemical Reactions in Chlorine Dioixde Stages of Pulp Bleaching, 1983, Wood Science and technology, 17, p. 117-228.
Witherspoon Kent
Yin Caifang
Barnes, III Thomas W.
Calandra Anthony
Daniels Matthew J
Eskami Matthew M.
Guttag Eric W.
LandOfFree
Process of bleaching softwood pulps in a D1 or D2 stage in a... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process of bleaching softwood pulps in a D1 or D2 stage in a..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process of bleaching softwood pulps in a D1 or D2 stage in a... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2697673