Patent GB-378034-A (GB)
Title: Improvements in and relating to the production and use of finely dispersed intermediates and dyestuffs
IPC: D06P1/16
Filed: 1931-04-27
Abstract: Finely dispersed dyestuff or dyestuff intermediate preparations are made by treating an aqueous paste of the dyestuff or intermediate containing a dissolved dispersing or wetting agent with an organic liquid which is miscible with water and in which the dyestuff or intermediate is substantially insoluble, and then substantially or completely removing the liquid phase by mechanical means, e.g. by filtration.  The soluble dispersing or wetting agents include sulphonic and carboxylic acids of aliphatic or aromatic compounds as well as sulphuric esters of oxy derivatives and soluble salts of these.  The pastes employed as starting materials are preferably in a moderately finely divided condition.  The products may be washed with a low boiling common organic solvent and the last traces of the liquid phase may, if desired, be removed by evaporation, either under reduced or ordinary pressure, and at temperature below 50 DEG  C.  In examples (1) Caledon Brilliant Blue R paste is mixed with a solution of "Dispersol" and methylated spirit added to the mixture; the filtered precipitate is washed with methylated spirit and then with ether; the dry product easily breaks down to a powder and readily disperses in cold water; (2) instead of using methylated spirit in (1) acetone is employed and the filtered product washed with acetone and dried at 30 DEG  C.; (3) 1 : 5-diamino-4 : 8-dihydroxyanthraquinone is first dissolved in sulphuric acid, the solution poured into water and the residue washed acid-free before treatment as in (2); (4) Caledon Blue RC paste is mixed with sulphite cellulose lye and cold methylated spirit added; the filtered product is treated as in (1).ALSO:Finely dispersed dyestuff or dyestuff intermediate preparations are made by treating an aqueous paste of the dyestuff or intermediate containing a dissolved dispersing or wetting agent with an organic liquid which is miscible with water and in which the dyestuff or intermediate is substantially insoluble, and then substantially or completely removing the liquid phase by mechanical means, e.g. by filtration.  The soluble dispersing or wetting agents include sulphonic and carboxylic acids of aliphatic or aromatic compounds as well as sulphuric esters of oxy derivatives and soluble salts of these.  The pastes employed as starting materials are preferably in a moderately finely divided condition.  The products may be washed with a low-boiling common organic solvent and the last traces of the liquid phase may, if desired, be removed by evaporation, either under reduced or ordinary pressure, and at temperatures below 50 DEG  C.  In examples (1) Caledon Brilliant Blue R. paste is mixed with a solution of "Dispersol" and methylated spirit added to the mixture; the filtered precipitate is washed with methylated spirit and then with ether; the dry product easily breaks down to a powder, readily disperses in cold water, and gives a good colour value when used for calico printing; (2) instead of using methylated spirit in (1) acetone is employed and the filtered product washed with acetone and dried at 30 DEG  C.; (3) 1 : 5-diamino-4 : 8-dihydroxyanthraquinone is first dissolved in sulphuric acid, the solution poured into water and the residue washed acid-free before treatment as in (2); (4) Caledon Blue R.C. paste is mixed with sulphite cellulose lye and cold methylated spirit added; the filtered product is treated as in (1).