Leucoindigo salt solution with very low content of aniline and method of making same
US11299633B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2018 |
| Grant date | Apr 12, 2022 |
| Priority date | — |
| Expiry date | Aug 10, 2038 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D3/14
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Stable aqueous leucoindigo solution comprising an aromatic amine in the form of aniline or aniline and N-methylaniline, wherein said leucoindigo is in the form of an alkali metal salt;wherein the concentration of the aromatic amine is below 40 ppm determined according to ISO 14362-1:2017(E); andwherein the concentration of the leucoindigo salt is in a concentration range of from 10 to 45% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 23° C.; orwherein the concentration of the leucoindigo salt is in a concentration range of from 45 to 65% by weight based on the total weight of the solution, and wherein the stability of the solution is measured at a temperature of 60° C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.