EP 0786029 B1 20000614 - METHOD FOR REMOVAL OF HEXENURONIC ACID GROUPS IN CELLULOSE PULP BY HEAT TREATMENT

Title (en)

METHOD FOR REMOVAL OF HEXENURONIC ACID GROUPS IN CELLULOSE PULP BY HEAT TREATMENT

Title (de)

VERFAHREN ZUM ENTFERNEN VON HEXENURONSÄUREGRUPPEN IN ZELLSTOFFBREI DURCH WÄRMEBEHANDLUNG

Title (fr)

PROCEDE D'ELIMINATION DE GROUPES D'ACIDE HEXENURONIQUE DANS DE LA PATE DE CELLULOSE PAR TRAITEMENT THERMIQUE

Publication

EP 0786029 B1 20000614 (EN)

Application

EP 95934164 A 19951012

Priority

FI 9500566 W 19951012
FI 944808 A 19941013

Abstract (en)

[origin: WO9612063A1] Pulp, in particular hardwood pulps, is delignified in cooking and, when needed, further delignified with oxygen to a kappa number below (24), preferably below (14). The delignified pulp is heated and treated at a temperature of about 85 to 150 DEG C, preferably 90 to 110 DEG C, at a pH of about 2 to 5 in order to decrease the kappa number by 2 to 9 units by removing at least 50 % of the hexenuronic acid groups in the pulp. The treated pulp is bleached in at least one bleaching stage.

IPC 1-7

D21C 9/00; D21C 9/10

IPC 8 full level

D21C 9/00 (2006.01); D21C 9/10 (2006.01); D21C 9/14 (2006.01); D21C 9/147 (2006.01)

IPC 8 main group level

D21C (2006.01)

CPC (source: EP)

D21C 9/001 (2013.01); D21C 9/1005 (2013.01)

Designated contracting state (EPC)

DE ES PT SE

DOCDB simple family (publication)

WO 9612063 A1 19960425; AU 3655995 A 19960506; CA 2160430 A1 19960414; CA 2160430 C 20041207; CN 1075143 C 20011121; CN 1168706 A 19971224; DE 69517532 D1 20000720; EP 0786029 A1 19970730; EP 0786029 B1 20000614; ES 2147303 T3 20000901; FI 102301 B1 19981113; FI 102301 B 19981113; FI 944808 A0 19941013; FI 944808 A 19960414; FI 971508 A0 19970410; FI 971508 A 19970410; JP 3534412 B2 20040607; JP H10508346 A 19980818; NO 971682 D0 19970411; NO 971682 L 19970611; NZ 293983 A 19990429; PT 786029 E 20000929; RU 2126862 C1 19990227; SE 518080 C2 20020820; SE 9503595 D0 19951013; SE 9503595 L 19960414; ZA 958655 B 19960513

DOCDB simple family (application)

FI 9500566 W 19951012; AU 3655995 A 19951012; CA 2160430 A 19951012; CN 95196599 A 19951012; DE 69517532 T 19951012; EP 95934164 A 19951012; ES 95934164 T 19951012; FI 944808 A 19941013; FI 971508 A 19970410; JP 51296596 A 19951012; NO 971682 A 19970411; NZ 29398395 A 19951012; PT 95934164 T 19951012; RU 97107353 A 19951012; SE 9503595 A 19951013; ZA 958655 A 19951013