CS202609B1 - Process for preparing raw copper phthalocyanine - Google Patents

Description

The invention relates to a process for the preparation of crude copper phthalocyanine.

Copper phthalocyanine is used in many applications as a blue pigment of very good properties after being processed from the raw state to the final pigment form.

Crude copper phthalocyanine is prepared in two main ways: by condensation of phthalic nitrile with copper salts net by condensation of a mixture of phthalic anhydride or phthalimide, and / or chlorinated or accumulated phthalic acid derivatives with urea and copper salts. Both condensation methods are carried out in the presence of a suitable catalyst, for example ammonium molybdate. In both condensation methods, the composition of the reaction mixture may be supplemented with a content of inorganic acid salts which are not directly involved in the reactions but may affect the form of phthalocyanine formed.

The condensation of copper phthalocyanine from phthalic acid nitrile or phthalic anhydride or phthalimide and / or chlorinated or accumulated phthalic acid derivatives is conveniently carried out at elevated temperature - a temperature in the range of about 180 to 230 ° C is used, mostly under an inert atmosphere such as nitrogen.

The condensation may be carried out in a dry manner, i.e. without the presence of a liquid medium, or vice versa in a liquid medium. Trichlorobenzene or nitrobenzene is most commonly used as the liquid medium in the preparation of copper phthalocyanine. A variety of liquids, such as alkylbenzenes, aromatic hydrocarbons, and the like, are also useful.

Most of these liquid environments have a number of unsatisfactory properties: toxicity, suspected carcinogenic effects, fire and explosion hazards; during condensation of phthalocyanine, toxic or carcinogenic by-products of the solvent are formed as a by-product of the solvent used at high temperatures.

It has now been found that these disadvantages can be overcome by the process of the invention.

The process for preparing crude copper phthalocyanine by condensation of phthalic acid nitrile with copper salts or by condensation of phthalic anhydride and / or phthalimide and / or chlorinated or accumulated phthalic acid derivatives with urea and copper salts in the presence of catalysts in liquid media or inorganic acid salts The liquid medium consists of an alkyl ester of an aromatic acid having a boiling point of 170 to 360 (> C. Very preferred is the use of methyl ptoluate (t 214 ° C, mp 33.2 ° C) alone or in admixture with the methyl ester (t 195 ° C) mp -12.3 ° C or ethyl ester (mp 213 ° C, mp -34.6 ° C) benzoic acid to lower the freezing point in any ratio.

The examples below illustrate embodiments of the invention. Parts are by weight.

Example 1

A mixture of 100 parts phthalic anhydride, 150 parts urea, 17 parts copper (I) chloride and 0.16 parts ammonium molybdate in methyl p-toluate (100 ml) is gradually heated to 200 ° C with stirring and maintained at this temperature for 1 hour. Reaction time 6.5 h. Methyl p-toluate is distilled off on a evaporator. Crude copper phthalocyanine is purified by washing with 5% sulfuric acid at 95 ° C and isolated. 90.2 parts of copper phthalocyanine were obtained, content 95.1%, yield 88.3%.

Example 2

A mixture of 100 parts of phthalic anhydride, 150 parts of urea, 17 parts of cuprous chloride and 0.16 parts of ammonium molybdate is heated in a 100 ml mixture of methyl p-toluate and methyl benzoate (1: 1) gradually to 200 ° C and this temperature was maintained for 1 hour. The reaction time is 6.5 h. The reaction product is treated in the same manner as in Example 1, the recovered solvent can be reused without any treatment.

Obtained; 89.5 parts copper phthalocyanine, content

95.5%, yield 87.9%.

Example 3

A mixture of 70 parts phthalic anhydride, 30 parts 4-chlorophthalic acid sodium salt, 132 parts urea, 14.7 parts copper (I) chloride and 0.15 parts ammonium molybdate was heated.

Claims (1)

SUBJECT Process for preparing crude copper phthalocyanine by condensation of phthalic anhydride or phthalimide or a mixture of phthalic anhydride and chlorinated phthalic acid derivatives with urea in the presence of monovalent or divalent copper salts or by condensation of phthalic nitrile with copper salt in the presence of catalyst and solvent -toluate and methyl benzoate (1: 1) gradually to 200 ° C and held at this temperature for 3 hours. Reaction time 8 hours. The reaction product isolated was treated in the same manner as in Example 1. 82.7 parts of 93% copper phthalocyanine with a chlorine content of 4-5% were obtained, yield 85%. Example 4 A mixture of 100 parts phthalimide, 105 parts urea, 17 parts copper (I) chloride and 0.16 parts ammonium molybdate in 100 ml of a mixture of methyl p-toluate and ethyl benzoate (1: 3) is heated gradually to 200 ° C with stirring and maintained at this temperature for 1 h. Reaction time 6 h. The reaction product was isolated in the same manner as in Example 1. 91.9 wt. parts of copper phthalocyanine 96.4%, yield 90.5%. Example 5 A mixture of 100 parts phthalodinitrile, 19.3 parts copper (I) chloride and 0.18 parts ammonium molybdate is heated under stirring for 8 hours to 200 ° C in an environment of 100 ml of methyl p-toluate and methyl benzoate (1: 1). The reaction product is isolated in the same manner as in Example 1. 107 parts of 96.8% copper phthalocyanine are obtained, yield 92.5%. Example 6 The composition of the reaction mixture and the condensation process according to Examples 1 to 5, after the reaction is completed, the crude copper phthalocyanine is first filtered off from the excess liquid medium and further processing of the obtained paste is the same as in Examples 1 to 5. SUMMARY OF THE INVENTION in the presence of inorganic acid salts, characterized in that the solvent used is methyl p-toluyl ester, optionally in admixture with a methyl or ethyl ester of benzoic acid having a benzoic ester content in the range of 0 to 99% based on the esters used.