EP 0250422 B1 19900613 - PROCESS FOR PREPARING BLEACHED PULP FROM LIGNOCELLULOSIC RAW MATERIAL
Title (en)
PROCESS FOR PREPARING BLEACHED PULP FROM LIGNOCELLULOSIC RAW MATERIAL
Publication
Application
Priority
- FI 851156 A 19850322
- FI 860609 A 19860211
Abstract (en)
[origin: WO8605529A1] Lignocellulosic raw material is pulped with a cooking liquor containing organic peroxyacids, such as peroxyformic acid or peroxyacetic acid, and the defibred pulp is bleached with an alkaline solution containing hydrogen peroxide, the pH of which is at least 10 in the beginning of the treatment, and which is provided by adding to a sodium hydroxide solution hydrogen peroxide in an amount which calculated as per cents of the dry weight of the matter coming to the treatment corresponds to from 0.20 to 0.80, preferably from 0.25 to 0.70 and most preferably from 0.45 to 0.65 times the kappa number of the pulp obtained from the previous stage of the process.
IPC 1-7
IPC 8 full level
D21C 3/00 (2006.01); D21C 3/04 (2006.01); D21C 9/16 (2006.01)
IPC 8 main group level
D21C (2006.01)
CPC (source: EP)
D21C 3/003 (2013.01); D21C 9/163 (2013.01)
Citation (examination)
Derwent's abstract no 07598 E/04, SU 821614
Designated contracting state (EPC)
AT DE FR SE
DOCDB simple family (publication)
WO 8605529 A1 19860925; AU 5589286 A 19861013; DE 3671924 D1 19900719; EP 0250422 A1 19880107; EP 0250422 B1 19900613; FI 74750 B 19871130; FI 74750 C 19880310; FI 860609 A0 19860211; FI 860609 A 19860923; JP H0737720 B2 19950426; JP S62502553 A 19871001
DOCDB simple family (application)
FI 8600028 W 19860324; AU 5589286 A 19860324; DE 3671924 T 19860324; EP 86901881 A 19860324; FI 860609 A 19860211; JP 50185686 A 19860324