Login| Sign Up| Help| Contact|

Patent Searching and Data

Document Type and Number:
Japanese Patent JPH07503042
Kind Code:
A method of bleaching sulphate pulp without using chlorine-containing bleaching agents. The sulphate pulp is oxygen delignified and can possibly also be ozone delignified to a kappa number below 9.5. Thereafter a pretreatment with complexing agent is carried out for 1-60 minutes, at which the pulp consistency is 1-15 %, the temperature 70-110 DEG C and pH 5-7. The pulp thus pretreated is washed and dewatered to a consistency of 18-40 %. Thereafter peroxide bleaching in alkaline environment takes place in the presence of silicate or an organic complexing agent of the type phosphonic or carboxylic acid.

Linstroem, Lars-Orches
Schyodane, Lars
Norden, Solvaig
Dahl, Norten
Application Number:
Publication Date:
March 30, 1995
Filing Date:
January 12, 1993
Export Citation:
Click for automatic bibliography generation   Help
Syundos Defibrator Industries Actie Evorague
International Classes:
D21C9/10; D21C9/147; D21C9/153; D21C9/16; (IPC1-7): D21C9/16
Attorney, Agent or Firm:
Yoshio Kawaguchi (2 outside)

Previous Patent: JPH07503041

Next Patent: JPH07503043