Patent GB-497514-A (GB)
Title: Process for the production of new chromium compounds of mordant dyestuffs soluble in organic solvents containing hydroxyl groups
IPC: C09B45/01
Filed: 1938-02-02
Abstract: Chromium compounds of mordant dyestuffs (which may contain carboxylic acids groups), soluble in organic solvents containing hydroxyl groups, and hydrolysable by water, are manufactured by treating complex chromium compounds of mordant dyestuffs substantially insoluble in water and organic solvents, which may be obtained by known chroming methods, in organic solution or suspension with strong acid reacting compounds, the reaction being effected in the absence of substantial amounts of water except the water content of the reactants used, the water present being not more than 20 per cent of the solvents or diluents employed.  As strong acid compounds may be employed mineral acids, e.g. hydrochloric, hydrobromic, perchloric, sulphuric, nitric, hydrofluoboric or hydrofluosilicic acid, acid salts, e.g. sodium bisulphate or bifluoride, compounds having a strong acid reaction by hydrolysis or decomposition, e.g. aluminium, stannic or ferric chloride or disodium pyrosulphate, or strong organic acids, e.g. chloracetic or trichloracetic acid.  The acid treatment may be combined with the chroming process, e.g. by adding the acid reacting substance to a mixture of dyestuff, chroming agent and an organic solvent containing hydroxyl, or by dissolving or suspending the dyestuffs or the dyestuff-carboxylic acids in non-polar organic solvents, which do not dissolve the products of the reaction, e.g. in nitrobenzene, and treating with a strong acid reacting chromium salt, e.g. chromyl chloride, or with the combination of a chroming agent with a strong acid at an elevated temperature.  Solutions of the products in organic solvents or mixtures containing hydroxyl groups are useful for paper staining or wood steeping.  In examples: (1) the chromium compound obtained by the action of sodium bichromate in alcohol on Eriochrome Azurol B is heated in alcohol with aqueous hydrochloric or nitric acid, or with hydrobromic, sulphuric, perchloric or hydrofluoboric acid; (2) the chromium compound of Eriochrome Azurol B is heated in alcohol with aluminium, stannic or ferric chloride, and (3) with sodium bisulphate solution; (4) Erio<\>chrome Azurol B is heated in nitrobenzene with chromyl chloride; (5) the insoluble chromium compound obtained by the action of chromium acetate in acetic acid on the phthalein dyestuff from 41-dimethylamino-21-hydroxy-2-benzoylbenzoic acid and b -resorcylic acid in sulphuric acid is heated in alcohol with aqueous hydrochloric or nitric acid; (6) the starting material of (5) is heated in alcohol with aqueous chloracetic acid; the products of (5) and (6) are suitable for colouring cellulose ester varnishes; (7) the insoluble chromium compound of the triphenylmethane dye from one molecular proportion of p-dimethylaminobenzaldehyde and two of o-cresotinic acid is heated in alcohol with aqueous nitric acid, or with hydrochloric or other acids; (8) the chromium compound of Naphthochrome Green G is heated in alcohol with aqueous hydrochloric acid; the product colours cellulose ester varnishes green shades; (9) Naphthochrome Green G is heated in alcohol with sodium bichromate and aqueous hydrochloric acid; other mordant dyestuffs, e.g. Eriochrome Azurol B or the dyestuff of (5), may be similarly treated; (10) the chromium compound obtained, e.g. by the action of chromium fluoride in water, from the dyestuff from methylene di-o-cresotinic acid and 3-methyl - 1 - phenyl - 5 - pyrazolone is heated in alcohol with aqueous hydrochloric or nitric acid; (11) the chromium compound obtained by the action of sodium bichromate in alcohol on the azo dyestuff anthranilic acid --> salicylic acid, or by the action of chromium acetate in water on an alkali metal salt of the dyestuff, is heated in alcohol with aqueous hydrochloric acid; (12) the insoluble chromium compounds obtained, e.g. by the action of bichromate in alcohol, from alizarin or substituted alizarins, e.g. 3-nitroalizarin, are heated in alcohol with aqueous hydrochloric acid; (13) the chromium compound obtained, e.g. by the action of chromium acetate in water, from Coelestine Blue B, is heated in alcohol with aqueous hydrochloric acid; the chromium compounds of Gallocyanine and Modern Violet may be similarly treated.