Light-stable and process-stable lignocellulosic materials and their production
US7384504B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 2003 |
| Grant date | Jun 10, 2008 |
| Priority date | — |
| Expiry date | Jun 9, 2024 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/163
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A novel method for the production of light-stable and process-stable lignocellulosic materials, in particular, the production of mechanical wood pulps with much improved light and process stability is described, as well as the resulting pulps of improved light and process stability and papers containing such pulps. The novel method involves the reaction of lignocellulosic materials such as bleached chemithermomechanical pulps (BCTMP) with (a) a water-soluble, fibre-reactive yellowing inhibitor possessing two or more secondary amino or ammonium (—NHR′ or —HN+HR′), tertiary amino or ammonium (—NR′R″ or —HN+R′R″), and/or quaternary ammonium (—N+R′R″R′″) functional groups in an aqueous medium, or (b) a water-soluble, fibre-reactive hindered amine light stabilizer possessing said amino or ammonium functional groups in an alkaline peroxide bleaching medium or in an aqueous medium with a subsequent bleaching of the materials in an alkaline peroxide bleaching medium. Examples of the water-soluble, fibre-reactive yellowing inhibitors are the novel, N-(2,2,6,6-tetramethyl-1-oxyl-piperidin-4-yl)-N′-{2-[2-(2,2,6,6-tetramethyl-1-oxyl-piperidin-4-ylamino)-ethylamino]-ethyl}-ethane-1,2-diamine (a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.