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1. WO2000019006 - OXYGEN BLEACHING OF PULP USING AN AGGLOMERATED BLEACH ACTIVATOR

Publication Number WO/2000/019006
Publication Date 06.04.2000
International Application No. PCT/GB1999/003178
International Filing Date 22.09.1999
Chapter 2 Demand Filed 10.04.2000
IPC
D21C 9/10 2006.1
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters
10Bleaching
D21C 9/16 2006.1
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters
10Bleaching
16with per compounds
CPC
D21C 9/1036
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
10Bleaching ; ; Apparatus therefor
1026Other features in bleaching processes
1036Use of compounds accelerating or improving the efficiency of the processes
D21C 9/163
DTEXTILES; PAPER
21PAPER-MAKING; PRODUCTION OF CELLULOSE
CPRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters ; ; Treatment of dilute or dewatered pulp or process improvement taking place after obtaining the raw cellulosic material and not provided for elsewhere
10Bleaching ; ; Apparatus therefor
16with per compounds
163with peroxides
Applicants
  • WARWICK INTERNATIONAL GROUP LIMITED [GB]/[GB] (AllExceptUS)
  • WITHENSHAW, John, David [GB]/[GB] (UsOnly)
  • WILLIAMS, Jane [GB]/[GB] (UsOnly)
  • CHADWICK, Mark, Ardern [GB]/[GB] (UsOnly)
  • TURNER, Neil, Anthony [GB]/[GB] (UsOnly)
Inventors
  • WITHENSHAW, John, David
  • WILLIAMS, Jane
  • CHADWICK, Mark, Ardern
  • TURNER, Neil, Anthony
Agents
  • GODDARD, David, John
Priority Data
9821165.930.09.1998GB
Publication Language English (en)
Filing Language English (EN)
Designated States
Title
(EN) OXYGEN BLEACHING OF PULP USING AN AGGLOMERATED BLEACH ACTIVATOR
(FR) BLANCHIMENT A L'OXYGENE AU MOYEN D'UN ACTIVATEUR AGGLOMERE
Abstract
(EN) Wood and non-wood pulp is bleached by: a) adding an aliquot of agglomerate from a bulk solids dispensing means, advantageously a hopper, to a dilute solution of hydrogen peroxide which is desirably agitated to keep the agglomerate in suspension, the agglomerate comprising: a bleach activator, advantageously tetraacetyl ethylene diamine (TAED); a peroxide soluble binder, preferably polyvinyl alcohol (PVOH); a dispersing system comprising a wetting agent which is a low foaming and does not discolour on exposure to temperatures of up to 120 °C and optionally a salt, preferably sodium acetate, which is highly soluble in hydrogen peroxide; and sequestrant which may additionally or alternatively be added directly to the hydrogen peroxide; b) allowing the TAED to substantially completely react with the hydrogen peroxide; c) adjusting the pH of the bleach solution by adding alkali, preferably caustic soda; and d) bleaching the pulp by contacting it with the bleaching solution under alkaline conditions.
(FR) Le blanchiment de la pâte à papier, à base ou non de bois, consiste à: a) ajouter une partie aliquote d'un agglomérat de pâte à papier sous forme de solides provenant d'un dispositif d'alimentation, de préférence une trémie, à une solution diluée de peroxyde d'hydrogène que l'on agite de préférence afin de maintenir l'agglomérat en suspension, lequel agglomérat comprend: un activateur de blanchiment si possible sous forme de tétraacétyl éthylène diamine (TAED); un liant soluble dans le peroxyde, de préférence un polyalcool de vinyle; un système dispersant renfermant un mouillant peu moussant et ne se décolorant pas jusqu'à 120 °C et éventuellement un sel, de préférence de l'acétate de sodium qui est très soluble dans le peroxyde d'hydrogène; et un agent séquestrant pouvant être ajouté, en plus ou en variante, directement au peroxyde d'hydrogène; b) laisser le TAED réagir complètement avec le peroxyde d'hydrogène; c) régler le pH de la solution de banchiment en ajoutant de l'alcali, de préférence de la soude caustique: et d) faire blanchir la pâte en la mettant en contact avec la solution de blanchiment en conditions alcalines.
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NO20011387This application is not viewable in PATENTSCOPE because the national phase entry has not been published yet or the national entry is issued from a country that does not share data with WIPO or there is a formatting issue or an unavailability of the application.
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