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1. (WO1991005909) HIGH EFFICIENCY CHLORINE DIOXIDE PULP BLEACHING PROCESS
Latest bibliographic data on file with the International Bureau

Pub. No.: WO/1991/005909 International Application No.: PCT/US1990/005825
Publication Date: 02.05.1991 International Filing Date: 17.10.1990
Chapter 2 Demand Filed: 16.05.1991
IPC:
D21C 9/14 (2006.01)
D TEXTILES; PAPER
21
PAPER-MAKING; PRODUCTION OF CELLULOSE
C
PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE- CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
9
After-treatment of cellulose pulp, e.g. of wood pulp, or cotton linters
10
Bleaching
12
with halogens or halogen-containing compounds
14
with ClO2 or chlorites
Applicants:
NORTH CAROLINA STATE UNIVERSITY [US/US]; 1 Holladay Hall Pullen Road Raleigh, NC 27695-7003, US
Inventors:
CHANG, Hou-min; US
SEGER, Geoffrey, Eugene; US
JAMEEL, Hasan; US
Agent:
JENKINS, Richard, Erik; 200 South Square Corporate Centre II 3708 Mayfair Street Durham, NC 27707, US
Priority Data:
424,34719.10.1989US
Title (EN) HIGH EFFICIENCY CHLORINE DIOXIDE PULP BLEACHING PROCESS
(FR) PROCEDE DE BLANCHIMENT DE CELLULOSE HAUTEMENT EFFICACE A L'AIDE DE DIOXYDE DE CHLORE
Abstract:
(EN) A high-efficiency wood pulp bleaching process to produce wood pulps with higher brightness at equal chlorine dioxide usage or of equal brightness at significantly reduced chlorine dioxide usage. The process comprises reacting the chlorine dioxide with wood pulp at a pH of about 5-10 for about 5-40 minutes and then acidifying the mixture to a pH of about 1.9-4.2. The mixture is then allowed to react for about 2 or more hours to complete the two-step high/low pH bleaching process.
(FR) Procédé de blanchiment hautement efficace de cellulose technique, permettant de produire des celluloses techniques d'une blancheur supérieure à l'aide d'une quantité de dioxyde de chlore égale, ou d'une blancheur égale à l'aide d'une quantité de dioxyde de chlore réduite de manière significative. Le procédé consiste à faire réagir le dioxyde de chlore avec de la cellulose technique à un pH compris entre environ 5 et 10 pendant environ 5 à 40 minutes, puis à acidifier le mélange jusqu'à un pH compris entre environ 1,9 et 4,2. Ensuite, on laisse réagir le mélange pendant environ deux heures ou plus, afin d'achever le procédé de blanchiment à pH haut/faible en deux étapes.
Designated States: AU, BB, BG, BR, CA, FI, HU, JP, KP, KR, LK, MC, MG, MW, NO, RO, SD, SU
European Patent Office (AT, BE, CH, DE, DK, ES, FR, GB, GR, IT, LU, NL, SE)
African Intellectual Property Organization (BF, BJ, CF, CG, CM, GA, ML, MR, SN, TD, TG)
Publication Language: English (EN)
Filing Language: English (EN)
Also published as:
AR243945EP0496782ES2085358CA2069322DE000069026105AU1990065376