EP 1062388 A1 20001227 - METHOD FOR BLEACHING PAPER PULP
Title (en)
METHOD FOR BLEACHING PAPER PULP
Title (de)
VERFAHREN ZUM ZELLSTOFFBLEICHEN
Title (fr)
PROCEDE DE BLANCHIMENT DE PATE A PAPIER
Publication
Application
Priority
- BE 9800189 A 19980310
- EP 9901611 W 19990306
Abstract (en)
[origin: WO9946440A1] The invention concerns a method for delignification and bleaching of chemical paper pulp comprising an acid treatment step for reducing by at least 10 % the amount of hexuronic acids present in the pulp, a step for adjusting the pulp pH for depositing or re-depositing alkaline earth metal ions on the pulp fibres, adding a chelating agent to the pulp before and/or during the acid treatment and/or before, during or after the pH adjusting step, a step for washing the pulp and a step for treating the pulp with an oxidising agent, the chelating agent being selected among aspartic acid and its derivatives substituted on the nitrogen atom.
IPC 1-7
IPC 8 full level
D21C 9/10 (2006.01)
CPC (source: EP)
D21C 9/1005 (2013.01); D21C 9/1042 (2013.01)
Citation (search report)
See references of WO 9946440A1
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
DOCDB simple family (publication)
WO 9946440 A1 19990916; AU 3411199 A 19990927; BE 1011784 A3 20000111; EP 1062388 A1 20001227; ZA 991898 B 20001011
DOCDB simple family (application)
EP 9901611 W 19990306; AU 3411199 A 19990306; BE 9800189 A 19980310; EP 99915578 A 19990306; ZA 991898 A 19990309