Process for the preparation of concentrated fluid dye compositions
US4500321A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1983 |
| Grant date | Feb 19, 1985 |
| Priority date | — |
| Expiry date | Feb 22, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B67/0096
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of storage-stable concentrated fluid dye compositions of water-soluble dyes, wherein an aqueous solution or suspension of at least one anionic crude dye is passed over a semi-permeable membrane containing ionic groups and having a pore diameter of 1 to 500 .ANG., to remove salts and synthesis by-products of molecular weights less than 500 and to partially remove water, optionally dried, and mixed with a water-miscible organic solvent and, if desired, further additives, before and/or after passage over the semi-permeable membrane. The fluid dye compositions obtained are particularly suitable for use in spray solutions for dyeing leather, as well as for the dying and printing of textile materials, in particular cellulosic fibres.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.