Patent · US Expired

Process for bleaching cellulose with organic peracid

US4400237A · kind A · utility

19Cited by

4References

8Claims

0Family size

Assignee

Degussa AG · DE

Inventors

Horst Kruger
Wilhelm Berndt · Frankfurt, DE
Hans Ulrich Süss · Hasselroth, DE

Key dates

Filing date	Feb 6, 1981
Grant date	Aug 23, 1983
Priority date	—
Expiry date	Feb 6, 2001

Classification

Technology area (CPC D)Textiles; Paper
CPC primaryD21C9/16
WIPO fieldTextile and paper machines
WIPO sectorMechanical engineering

Abstract

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.