Global Patent Index - EP 0946819 A1

EP 0946819 A1 19991006 - BLEACHING OF CELLULOSIC PULP WITH OZONE AND PERACID

Title (en)

BLEACHING OF CELLULOSIC PULP WITH OZONE AND PERACID

Title (de)

BLEICHEN VON ZELLSTOFF MIT OZON UND PERSÄURE

Title (fr)

BLANCHIMENT DE PATE A PAPIER CELLULOSIQUE A L'AIDE D'OZONE ET DE PERACIDE

Publication

EP 0946819 A1 19991006 (EN)

Application

EP 97913227 A 19971126

Priority

  • FI 9700730 W 19971126
  • FI 964715 A 19961126

Abstract (en)

[origin: WO9823811A1] The invention concerns a method for the production of pulp. According to this method, pulp is treated with ozone in at least one bleaching stage. In accordance with the invention, ozone-treated pulp is brought into contact with a peroxy alkanoic acid under acid conditions in order to reduce the pulp's alkali lability, and the resulting pulp is subjected to an alkaline extraction stage or peroxide bleaching stage. The bleaching sequences are thus of teh type Z/Paa/E or Z/Paa/P, for example. The pulp produced according to the invention has a kappa number of less than 2, a viscosity of more than 600 ml/g, a tear index (T70) of over 13 mN.m<2>/g and a zero-span tensile index (T70) as measured from a wet sheet of over 100 N.m/g.

IPC 1-7

D21C 9/153; D21C 9/16

IPC 8 full level

D21C 9/153 (2006.01); D21C 9/16 (2006.01)

CPC (source: EP)

D21C 9/153 (2013.01); D21C 9/166 (2013.01)

Citation (search report)

See references of WO 9823811A1

Designated contracting state (EPC)

AT CH DE FR LI PT SE

DOCDB simple family (publication)

WO 9823811 A1 19980604; AU 5056198 A 19980622; CA 2270967 A1 19980604; EP 0946819 A1 19991006; FI 964715 A0 19961126; FI 964715 A 19980527

DOCDB simple family (application)

FI 9700730 W 19971126; AU 5056198 A 19971126; CA 2270967 A 19971126; EP 97913227 A 19971126; FI 964715 A 19961126