EP 0652321 A1 19950510 - Chemical pulp bleaching.
Title (en)
Chemical pulp bleaching.
Title (de)
Bleichen von chemischen Zellstoff.
Title (fr)
Blanchiment de pâte à papier chimique.
Publication
Application
Priority
US 14811893 A 19931104
Abstract (en)
Wood pulp, such as kraft, chemical or hybrid pulp, is subjected to a bleaching process wherein it is treated first with one or more oxidising agents such as oxygen, ozone or hydrogen peroxide, and then with a reducing agent such as sodium borohydride or sodium hydrosulfite. A further treatment with an oxidising agent can be carried out after the reducing treatment. Brightness may be further enhanced by treatment with an enzyme such as xylanase or with a chelant such as diethylenetriamine pentaacetic acid (DTPA).
IPC 1-7
IPC 8 full level
CPC (source: EP)
D21C 5/005 (2013.01); D21C 9/1057 (2013.01); D21C 9/1084 (2013.01)
Citation (search report)
- [X] WO 9207139 A1 19920430 - INTEROX INT SA [BE]
- [PX] FR 2692917 A1 19931231 - AIR LIQUIDE [FR], et al
- [A] WO 9114823 A1 19911003 - CALL HANS PETER [DE]
Designated contracting state (EPC)
SE
DOCDB simple family (publication)
EP 0652321 A1 19950510; EP 0652321 B1 19980121; FI 945202 A0 19941104; FI 945202 A 19950505
DOCDB simple family (application)
EP 94307702 A 19941020; FI 945202 A 19941104