30 августа, 2015 
Pokraskin Two processes are commonly used for the production of copper phthalocyanine: the phthalic anhydride-urea process patented by ICI [33,34] and the I. G. Farben dinitrile process [48]. Both can be carried out continuously or batchwise in a solvent or by melting the starting materials together (bake process). The type and amount of catalyst used are crucial for the yield. Especially effective as catalysts are molybdenum(iv) oxide and ammonium molybdate. Copper salts or copper powder is used as the copper source [35-37]; use of copper(I) chloride results in a very smooth synthesis. Use of copper(I) chloride as starting material leads to the formation of small amounts of chloro CuPc. In the absence of base, especially in the bake process, up to 0.5 mol of chlorine can be introduced per mole of CuPc with CuCl, and up to 1 mol with CuCl2.
The patent literature gives details of modifications and refinements of the original processes. A review of older processes is given in [35,36], and examples of more modern production methods are described in [37,49].
As apparatus for the batch process, an enamel or steel reactor with an agitator and pressure steam or oil heating suffices. Apparatuses used in the continuous synthesis in the presence of solvents and in the bake process are described in [50] and [51,52], respectively. The choice of process depends on the availability and cost of the starting materials phthalodinitrile or phthalic anhydride. Although the phthalodinitrile process has certain advantages over the phthalic anhydride process, the latter is preferred worldwide because of the ready accessibility of phthalic anhydride. In this process the molar ratio of phthalic anhydride, urea, and cop — per(I) chloride is 4:16:1, with ammonium molybdate as catalyst. The mixture is heated in a high-boiling solvent such as trichlorobenzene, nitrobenzene, or kerosene. The solvent is removed after the formation of copper phthalocyanine. Frequently a purification step follows. Carrying out the reaction under pressure gives a high-purity CuPc pigment [53].
Several dry processes have also been described [37, II, p. 32]. The solvent can be replaced by ammonium chloride [54], a fourfold excess of phthalic anhydride, sodium chloride [55], or a 1:1 NaCl-MgCl2 mixture [37,56]. In the dry reaction, the ammonium molybdate catalyst can be replaced by a molybdenum or molybdenum alloy agitator [36,37].
Another dry process is run continuously [57]. The dry, powdered reaction mixture is fed into a rotary furnace kept at 180°C, and the dry product is discharged into a drum at a yield of 96% [36,37]. A vacuum method for the preparation of relatively pure CuPc is described in [58].
One improvement of the process consists of grinding phthalodinitrile, anhydrous CuCl, and urea; mixing the powder thoroughly (or grinding in a ball mill); and heating it to 150°C. The temperature increases to 310°C due to the heat of reaction, thus completing the reaction within a few minutes. After purification the yield is 97%, and the product contains 0.3% Cl [37, II, p. 30; 59]. Carrying out the reaction in the presence of a salt that decomposes at 30-200 °C to form ammonia improves the yield [60].
The reaction has also been carried out in solvents such as trichlorobenzene in the presence of pyridine [61]. Pyridine converts the insoluble copper(I) chloride into a soluble complex, which reacts more quickly.
The reaction can be accelerated by the use of sodium hydroxide or sulfonic or carboxylic acids [62] instead of pyridine. Other high-boiling solvents such as nitrobenzene, benzophenone, or naphthalene can be used instead of trichlorobenzene [36,37,63-66].
Diiminoisoindolenine Process. An alternative route is the formation of the isoin — dolenines, which are then treated with copper(II) salts [67-69]. 1,3-Diiminoisoin — dolenine is prepared by reaction of phthalonitrile with ammonia. The isoindole — nine is then treated with copper acetate in ethylene glycol and 2-chlorobenzoni — trile at 60-70 °C for 1 h.
Copper phthalocyanine can also be made by milling diiminoisoindolenine, copper(I) chloride, anhydrous sodium sulfate, and ethylene glycol at 100-110°C.
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