EP 0595386 A1 19940504 - Process for bleaching of lignocellulose-containing pulp.
Title (en)
Process for bleaching of lignocellulose-containing pulp.
Title (de)
Verfahren zum Bleichen von Lignocellulose-enthaltenden Zellstoffen.
Title (fr)
Procédé pour le blanchiment de pâte à papier contenant de la lignocellulose.
Publication
Application
Priority
SE 9203200 A 19921029
Abstract (en)
The present invention relates to a process for bleaching of lignocellulose-containing pulp, in which the pulp is treated at a pH between about 1 and about 7 in the presence of a magnesium compound, whereupon the pulp is washed and subsequently bleached with a peroxide-containing compound. The initial treatment removes from the pulp those trace metal ions that have a negative effect on the subsequent bleaching with a peroxide-containing compound. Owing to the presence of magnesium ions in dissolved form during the initial treatment, the magnesium ions are retained in those positions in the pulp where they have a particularly positive effect on the effectiveness of the bleaching stage.
IPC 1-7
IPC 8 full level
D21C 9/10 (2006.01); D21C 9/147 (2006.01); D21C 9/16 (2006.01)
CPC (source: EP)
D21C 9/1005 (2013.01); D21C 9/1036 (2013.01); D21C 9/163 (2013.01)
Citation (search report)
- [PYPA] EP 0511695 A1 19921104 - EKA NOBEL AB [SE]
- [Y] US 3507744 A 19700421 - GRANGAARD DONALD H
- [A] US 2687943 A 19540831 - PETE ROBERT H
- [A] DATABASE WPI Section Ch Week 7727, Derwent World Patents Index; Class E33, AN 77-47879Y
Designated contracting state (EPC)
AT BE CH DE ES FR IT LI PT SE
DOCDB simple family (publication)
EP 0595386 A1 19940504; EP 0595386 B1 19990526; EP 0595386 B2 20020717; AT E180523 T1 19990615; AU 4919993 A 19940512; AU 659039 B2 19950504; BR 9304438 A 19940503; CA 2109179 A1 19940430; CZ 224193 A3 19940518; CZ 284366 B6 19981111; DE 69325070 D1 19990701; FI 934705 A0 19931025; FI 934705 A 19940430; JP H06207392 A 19940726; MX 9306618 A 19940429; NO 302766 B1 19980420; NO 933873 D0 19931027; NO 933873 L 19940502; NZ 250050 A 19941222; RU 2072014 C1 19970120; SE 512137 C2 20000131; SE 9203200 D0 19921029; SE 9203200 L 19940430; SK 117593 A3 19940511; ZA 937908 B 19940524
DOCDB simple family (application)
EP 93202821 A 19931004; AT 93202821 T 19931004; AU 4919993 A 19931025; BR 9304438 A 19931029; CA 2109179 A 19931025; CZ 224193 A 19931022; DE 69325070 T 19931004; FI 934705 A 19931025; JP 29145993 A 19931028; MX 9306618 A 19931025; NO 933873 A 19931027; NZ 25005093 A 19931026; RU 93049739 A 19931029; SE 9203200 A 19921029; SK 117593 A 19931025; ZA 937908 A 19931025