Patent GB-588231-A (GB)
Title: Process for the preparation of phthalo-cyanine dyes
IPC: C09B47/08
Filed: 1945-02-07
Abstract: Dyes of the phthalocyanine series are manufactured by heating halogen phthalocyanines (containing the halogen in the phenyl nuclei) at temperatures between 150 DEG  and 225 DEG  C. with aliphatic, araliphatic or aromatic mercapto compounds in the presence of an alcohol having a boiling point above 150 DEG  C., and if desired with the addition of a catalyst consisting of copper or a copper compound. An acid-binding agent may also be present, advantageously being first dissolved in the alcohol, or the mercapto compounds may be used in the form of their metal derivatives.  The products may be separated by filtration (preferably after addition of methyl or ethyl alcohol and with subsequent washing with alcohol and water) or by expelling the alcohol by distillation, vacuum distillation or steam distillation.  Suitable starting materials are those obtained by halogenation of metal-containing or metal-free phthalocyanines, or the symmetrical halogen phthalocyanines obtainable by condensing halogen phthalic anhydrides (e.g. 3- or 4-mono-halogen, di-, tri- or tetra-halogen phthalic anhydrides) with urea and metals or metal-yielding substances or from the corresponding halogen phthalonitriles.  When the starting material is metal-free, a concurrent metallization may be effected by carrying out the condensation in the presence of metals or metal compounds.  In examples: (1) a copper phthalocyanine containing 18 per cent of chlorine (prepared by direct chlorination of copper phthalocyanine) is heated to 180-205 DEG  C. with thiophenol, caustic potash, benzyl alcohol and, if desired, copper powder; (2) symmetrical tetrachloro-copper-phthalocyanine (obtained by condensing 4-chlorophthalic anhydride with urea and cuprous chloride) is heated to 190-205 DEG  C. with p-thiocresol, caustic potash and benzyl alcohol; the p-thiocresol may be replaced by a - or b  - thionaphthol, and the phthalocyanine wholly or partly by that obtained similarly from 3-chlorophthalic anhydride (or nitrile); (3) tetrabromo-copper-phthalocyanine (prepared by direct bromination of copper phthalocyanine) is heated to 150-205 DEG  C. with p-thiocresol (or other mercapto compounds, e.g. ethyl mercaptan, thiophenol, o-thiocresol, halogenthiophenols, a - or b -thionaphthols or their 5 : 6 : 7 : 8-tetrahydro derivatives or dodecyl mercaptan, or mixtures of mercapto compounds, or polyvalent mercaptans), caustic potash and benzyl alcohol (or other alcohol boiling above 150 DEG  C.), with or without copper powder; (4) symmetrical tetrachloro-copper phthalocyanine (from 4-chlorophthalic anhydride) is heated to 180-205 DEG  C. with benzyl mercaptan, caustic potash and benzyl alcohol; (5) the benzyl mercaptan in (4) is replaced by octyl mercaptan (or other aliphatic mercaptan, e.g. dodecyl, cetyl or butyl mercaptan, or mixtures of mercaptans), and the condensation is effected in the presence of copper powder; (6) thiophenol is similarly condensed, in the presence or absence of copper powder; the caustic potash may be replaced by other acid-binding agents, e.g. caustic soda or potassium or sodium carbonate, and the phthalocyanine by the corresponding tetra-bromo-copper-phthalocyanine or the tetra-halogen compounds of other metal phthalocyanines or of metal-free phthalocyanines, in the last instance with the addition, if desired, of a metal or metal compound, e.g. copper, cobalt, nickel, iron, copper halides or copper sulphide; (7) symmetrical tetrachloro-nickel-phthalocyanine (prepared by condensing 4-chlorophthalic anhydride with urea and nickel chloride) is heated to 160-205 DEG  C. with p-thiocresol, caustic potash and benzyl alcohol; the phthalocyanine may be replaced by other tetrachloro - metal - phthalocyanines, e.g. the cobalt or iron compounds; (8) the starting material of (4) is heated to 195 DEG  C. with p-thiocresol, caustic potash and benzyl alcohol; (9) octochloro-copper-phthalocyanine (obtainable by condensing the technical mixture of the three dichlorophthalic anhydrides with urea and cuprous chloride) is heated to 190-205 DEG  C. with p-thiocresol, caustic potash, benzyl alcohol and, if desired, copper powder; the phthalocyanine may be replaced by more highly halogenated metal or metal-free phthalocyanines, and the p-thiocresol by other mercaptans, the proportions of which may be varied.  Other alcohols specified are octyl alcohol, glycol, diethanolamine, and phenylethyl alcohol. Specification 492,177 is referred to.  Octyl mercaptan is obtainable by condensation of octyl chloride with sodium sulphydrate.  Samples have been furnished under Sect. 2 (5) of products obtained by the condensation of symmetrical tetrachloro-copper-phthalocyanine (from 4-chlorophthalic anhydride) with: (I) p-thiocresol in the presence of potassium hydroxide and diethylene glycol monobutyl ether, and (II) lauryl alcohol; (III) 5 : 6 : 7 : 8-tetra-hydro-1-thionaphthol in the presence of potassium hydroxide and benzyl alcohol.  The Specification as open to inspection under Sect. 91 comprises also the use of alicyclic mercapto compounds and of alcohols boiling below 150 DEG  C., e.g. methyl, ethyl and amyl alcohols.  This subject-matter does not appear in the Specification as accepted.