Patent GB-687655-A (GB)
Title: New products useful as dyestuffs intermediates and their manufacture and use
IPC: D06P5/00
Filed: 1949-01-14
Abstract: Cobalt phthalocyanine intermediates are made by heating phthalic anhydride, phthalimide, or mono-iminophthalimide with cobalt salts, ammonium molybdate and urea or biuret, or alternatively phthalonitrile and cobalt salts only, up to 140-190 DEG  C., and interrupting the heating when a substantial amount of a yellow to brown-red solid has formed but before a substantial amount of cobalt phthalocyanine is observed.  A solvent such as nitrobenzene or di- or tri-chlorbenzene may be present if desired.  Cobalt salts specified are the chloride, nitrate, acetate, and sulphate, and the latter may be used in admixture with ammonium chloride.  The intermediates resemble the complex cobalt salts described by Werner, the anions being hydroxy groups or acid anions according to conditions during formation and working up.  The hydroxy complexes may be converted to, e.g. chlorides, sulphates, or nitrates with the appropriate acids, and may be purified by dissolution in strong acids or alkalies, in presence of alcohols, followed by precipitation with water.  They are converted to phthalocyanines by heating to higher temperatures or by the action of reducing agents, and they may also be converted on the fibre by acid or neutral steam treatment, together with reducing agents, and may hence be used for dyeing or printing textiles. Reducing agents specified are sodium hydrosulphite, ferrous sulphate, titanium tetrachloride, stannous chloride, polyhydric alcohols, glucose, and aldehyde bisulphite compounds, which may be used with tragacanth, wheat starch, British gum, or dextrin as thickeners in printing pastes. Solvents specified for such pastes or otherwise forming phthalocyanines on the fibre are formamide, N-methylformamide, dimethyl - formamide, dimethylol - formamide, glycol, diglycol, thiodiglycol, glycol monoethyl ether, glycerol, methanol, dioxane, pyridine, phthalimide, or mixtures thereof.  In examples: (1) phthalic anhydride is heated with urea and ammonium molybdate, together with cobalt chloride alone or with nitrobenzene or o-dichlorbenzene, or together with cobalt nitrate and nitrobenzene; (2) phthalimide is heated with urea, ammonium molybdate, cobalt chloride, and nitrobenzene; (3) phthalonitrile is heated with cobalt chloride and nitrobenzene.  Further examples describe purifying the product of (1) by (4) dissolving in methanol containing caustic soda and precipitating the hydroxy complex with glacial acetic acid; and (5) dissolving in methanol containing sulphuric acid or in concentrated sulphuric acid only, followed by dilution with water.  There is also described the conversion of the hydroxy complex to the chloride and nitrate by use of hydrochloric and nitric acids respectively, and the formation of halogen-free bodies by reaction of the chloride with hexahydroaniline or pyridine. Further examples describe the conversion of the hydroxy complex to cobalt phthalocyanine by (6) heating on the water-bath with hydrazine hydrate in glacial acetic acid, pyridine, triethanolamine, diethylaminoethanol, glycol monoethylether or glycol; (7) heating to 300-320 DEG  C.; (8) treating with pyridine and caustic soda solution containing sodium hydrosulphite, glucose, or sodium formaldehyde-sulphoxylate; (9) heating on the water-bath with ethylene glycol and caustic soda solution, and also the conversion of the chloride complex by (10) heating in quinoline or trichlorbenzene with piperidine; (11) reacting with pyridine and reducing with titanium tetrachloride in glacial acetic acid.  Also (12) the product of (1) above is pasted with phenylhydrazine to give the phthalocyanine.  Examples further describe printing pastes containing the phthalocyanine intermediates and (1) ethylene glycol, caustic soda, tragacanth, and hydrazine sulphate; (2) ethylene glycol, potash, tragacanth, thiodiglycol, glycerine; (3) p-toluene sulphamide, dimethyl formamide, glycerol, caustic soda, tragacanth, potash, glucose; (4) diglycol, ethylene glycol, triethanolamine, tragacanth, diethyl tartrate, and benzaldehyde bisulphite.