Low electrolyte sodium lignosulfonates
US4590262A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 5, 1984 |
| Grant date | May 20, 1986 |
| Priority date | — |
| Expiry date | Oct 5, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09D17/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A method of producing sodium salts of low electrolyte-containing sulfonates suited for use as dye and print paste additives comprising of the steps of ionizing the phenol component of a lignin material in an alkaline liquid medium, methylolating the ionized phenol component of the lignin material, lowering the pH of the liquid medium to an acid pH to precipitate the methylolated lignin material, washing the precipitated lignin material with water to remove inorganic salts and residual reactants therefrom, and sulfonating the washed, purified methylolated lignin material with a sodium salt of a sulphur-oxygen containing compound in a liquid medium. The washed, purified methylolated lignin material is preferably sulfonated at an acid pH level to minimize the production of salts and electrolytes produced when acidifying the lignin for dye and print paste composition additives. Lignin products produced by the method, and dye and print paste compositions containing such products are also disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.