Patent · US Expired

Process for the preparation of delignified and bleached chemical paper pulps

US6019870A · kind A · utility

9Cited by
2References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 17, 1997
Grant dateFeb 1, 2000
Priority date
Expiry dateJan 17, 2017

Classification

  • Technology area (CPC D)Textiles; Paper
  • CPC primaryD21C9/163
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

A process of dignifying lignocellulosic pulp with oxygen followed by treatment of the delignified pulp with a chelating agent, followed by washing, followed by treatment with hydrogen peroxide at an alkaline pH in the presence of an alkali metal silicate at a temperature greater than 100.degree. C. and a pressure greater than 1.5 times the saturated vapor pressure.

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