Patent GB-729124-A (GB)
Title: Process for preparing metal phthalocyanines
IPC: C09B47/06
Filed: 1951-10-29
Abstract: In a process for preparing a metal phthalocyanine by heating in an inert organic diluent which is liquid at the reaction temperature, a reaction mixture containing a phthalocyanine-forming metal-yielding reagent and an aromatic o-dinitrile or a mixture of a nitrogen donor compound with an aromatic phthalocyanine intermediate having ortho-substituents which form a tetrazaporphine ring upon heating in said reaction mixture, there is included in the reaction mixture a member of the group consisting of aliphatic monobasic sulphonic acids containing 1 to 5 carbon atoms in the molecule, salts thereof with alkali metals, alkaline earth metals, ammonium, or phthalocyanine-forming metals, lower aliphatic alcohol esters thereof in which the alcohol radical contains 1 to 4 carbon atoms, and the corresponding amides and acid halides, in an amount corresponding to at least 25 per cent of the weight of said aromatic o-dinitrile or said phthalocyanine intermediate, said sulphonic acid compound being non-reactive toward the phthalocyanine resulting in the reaction (except for yielding a phthalocyanine-forming metal thereto) and non-reactive toward the ortho-substituted aromatic intermediate therefor in such manner as to combine therewith or to modify the structure of the resulting phthalocyanine.  The organic phthalocyanine-forming intermediate may be one of the group consisting of aromatic o-dicarboxylic acids, their anhydrides, acid halides, salts (especially ammonium salts), corresponding mono- or di-amides, imides, iminoimidines, esters or ammonium salt of the mono-amide, corresponding o-cyano-carboxylic acid and its esters, ammonium salt or amide, corresponding o , o 1-polychloro- or polybromo-o-dimethyl aromatic compounds or o -chloro- or bromomethyl-o-cyano aromatic compounds and may contain additional nuclear substituents which are non-reactive under the reaction conditions, such as halo (e.g. chlorine or bromine), nitro, alkyl, aryl, condensed nuclear aryl, alkoxy, aryloxy, alkylthio, arylthio, and aryl keto or alkyl keto (acyl) radicals.  The nitrogen donor may be urea, biuret, guanidine, guanidylurea, dicyandiamide or cyanuric acid.  Specified aliphatic monobasic sulphonic acids and their derivatives include the sodium, potassium, ammonium, calcium, strontium, barium, copper, nickel, iron, cobalt, tin, aluminium, magnesium and zinc salts of methane sulphonic acid, ethane sulphonic acid, propane-a -and-b -sulphonic acids, n-butane sulphonic acid, isobutane and isopentane sulphonic acids, allyl sulphonic acid and sulphonic acids containing chain substituents such as chlorine, hydroxy, amino, or nitro, e.g. taurine, isethionic acid, b -chloro-ethane sulphonic acid, b -nitroethane sulphonic acid, mixed saturated aliphatic hydrocarbon sulphonic acids (e.g. of methane, ethane and propane), and the corresponding free acids, acid chlorides, acid bromides, amides, and lower aliphatic alcohol esters in which the alcohol radical contains 1 to 4 carbon atoms, e.g. the methyl or ethyl esters.  The sulphonic acids or derivatives are preferably employed in an amount of about one-half to two-thirds of the weight of the aromatic o-dinitrile or aromatic phthalocyanine-forming intermediate.  The reaction is generally carried out at 150-210 DEG  C. and is preferably carried out in the presence of a catalyst containing an element of Group V or VI of the periodic system having an atomic number from 15 to 92 inclusive, especially a molybdate such as an alkali metal or ammonium molybdate, phosphomolybdate or tungstomolybdate. Specified metal yielding reagents are the usual polyvalent metals and their salts such as those of copper, aluminium, magnesium, nickel, iron, cobalt, zinc, and vanadium.  Suitable salts of the metals, in addition to salts of the aliphatic sulphonic acids specified above, include the chlorides, bromides, sulphates and nitrates.  The oxides of the metals may also be used.  Specified organic diluents are trichlorobenzene, dichlorobenzene, naphthalene and its chlorinated derivatives, quinoline, and benzophenone.  In examples (1) chloroaluminium phthalocyanine is obtained by forming a slurry of phthalic anhydride, urea, ethane sulphonic acid and ammonium molybdate, adding a slurry of anhydrous aluminium chloride in trichlorobenzene and heating the mixture to 200-205 DEG  C. for 6 hours followed by the addition of a slurry of urea in trichlorobenzene and further heating at 200-205 DEG C. for 5 hours.  Ammonium, calcium, magnesium, or aluminium ethanol sulphonate may be used instead of ethane sulphonic acid; (2) hexadecachloro-copper phthalocyanine is obtained by heating a mixture of tetrachlorophthalic anhydride, ethane sulphonic acid, cuprous chloride, urea and ammonium molybdate in trichlorobenzene at 200-205 DEG  C. for 5 hours; (3) chloroaluminium phthalocyanine is obtained by heating a mixture of phthalamide, urea, aluminium trichloride, ammonium molybdate, and a mixture of methane-, ethane-, and propane sulphonic acids in trichlorobenzene for 1 hour at 200-205 DEG  C., adding a slurry of urea in trichlorobenzene and heating at 200-205 DEG  C. for 5 hours. Phthalimide or o-cyanobenzamide may be used instead of phthalamide; (4) nickel phthalocyanine is formed by heating a slurry of phthalic anhydride, urea, anhydrous nickel chloride, ammonium molybdate and sodium ethane sulphonate in trichlorobenzene for one hour, adding urea in trichlorobenzene and then heating for 4 hours at 200 DEG  C.; (5) magnesium phthalocyanine is formed by heating a slurry of phthalic anhydride, urea, magnesium oxide, ammonium molybdate and ethane sulphonic acid (or magnesium ethanol sulphonate) in trichlorobenzene at 200 DEG  C. for 4 hours. As metal donors metallic copper or other cuprous salts can be used instead of cuprous chloride, aluminium sulphate or acetate can replace aluminium chloride, magnesium nitrate or chloride can replace magnesium oxide and nickel nitrate can replace nickel chloride whilst salts of cobalt, metallic zinc or its salts, iron or iron salts can be substituted for the metal compounds of the examples to prepare the corresponding metal phthalocyamines.  U.S.A. Specification 2,214,477 and U.S.A. Application 403,866 published by the Alien Property Custodian of the U.S.A. are referred to.