Global Patent Index - EP 0034219 B2

EP 0034219 B2 19860416 - PROCESS FOR BLEACHING CELLULOSE PULPS BY MEANS OF ORGANIC PERACIDS

Title (en)

PROCESS FOR BLEACHING CELLULOSE PULPS BY MEANS OF ORGANIC PERACIDS

Publication

EP 0034219 B2 19860416 (DE)

Application

EP 80108011 A 19801218

Priority

DE 3005947 A 19800216

Abstract (en)

[origin: US4400237A] Cellulose is bleached by means of an organic peracid in the acid region and subsequently by means of peroxide in the alkaline region. As peracid there is employed an acid which is produced from the corresponding carboxylic acid by reaction with hydrogen peroxide in the presence of a mineral acid. The peroxide bleaching step which follows the peracid bleaching step is carried out after there is added the necessary amount of aqueous alkali solution for carrying out the peroxide bleaching step of the pulp without intermediate washing of the cellulose. A further addition of peroxide is not carried out.

IPC 1-7

D21C 9/16

IPC 8 full level

D21C 9/16 (2006.01)

CPC (source: EP US)

D21C 9/16 (2013.01 - EP US)

Designated contracting state (EPC)

AT BE CH DE FR GB IT LU NL SE

DOCDB simple family (publication)

US 4400237 A 19830823; AT E1826 T1 19821215; BR 8100867 A 19810825; CA 1144711 A 19830419; DE 3005947 B1 19810129; DE 3061114 D1 19821223; EP 0034219 A1 19810826; EP 0034219 B1 19821117; EP 0034219 B2 19860416; FI 68685 B 19850628; FI 68685 C 19851010; FI 810366 L 19810817; JP S56128389 A 19811007; NO 155499 B 19861229; NO 810057 L 19810817; ZA 81785 B 19820331

DOCDB simple family (application)

US 23221781 A 19810206; AT 80108011 T 19801218; BR 8100867 A 19810213; CA 370899 A 19810213; DE 3005947 A 19800216; DE 3061114 T 19801218; EP 80108011 A 19801218; FI 810366 A 19810209; JP 2026381 A 19810216; NO 810057 A 19810109; ZA 81785 A 19810205