KR810000314B1 - Process for producing copper phthalocyanines - Google Patents

Abstract

Copper phthalocyanines are produced by reacting a phthalic anhydride or phthalimide with a copper compound and urea in the presence of a catalyst in a polyalkyl-monochlorobenzene having at least two lower alkyl groups and having the formula(I) wherein R1 and R2 respectively represent a lower alkyl group having 1 to 3 carbon atoms; R3 and R4 respectively represent hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms.

Description

Method for producing copper phthalocyanines

The present invention relates to a method for producing copper phthalocyanines which are the most important organic pigments, and more particularly, to reacting phthalic anhydrides or phthalimides with copper compounds and urea in the presence of a catalyst in selected polyalkyl monochlorobenzenes. The present invention relates to a method of industrially advantageously producing copper phthalocyanines having high quality and excellent coloring power without causing by-products of harmful substances.

Conventionally, in the method for industrially producing copper phthalocyanines by reacting phthalic anhydride or phthalimide with a copper compound and urea in the presence of a catalyst, the yield of the target copper phthalocyanines is influenced by the reaction solvent selected. It is known that not only the resin but also a great influence on the coloring power and color tone of the copper phthalocyanines to be produced, and the physical conditions as the optimum reaction solvent, the boiling point at atmospheric pressure of 160 to 250 It is also known that the difference between the initial point and the dry point must be within 10 ° C, and that the thermal stability is good. Trichlorobenzene, nitrobenzene, alkylbenzenes, and the like are used as reaction solvents that substantially satisfy these conditions. However, trichlorobenzene is a compound that is toxic in itself, and a further disadvantage is that a copper compound is present in the reaction system. Its presence causes a ullmann reaction, whereby trichlorobenzene is polycondensed to by-produce the most fearful harmful polychlorinated biphenyl (PCB) as an environmental pollutant.

In addition, since nitrobenzene is highly toxic, the allowable concentration in the air for labor hygiene is regulated to 1PPm, and when it is adhered to the skin or the like, it is rapidly absorbed into the body. Particularly, when nitrobenzene is used industrially, it is not an industrially suitable reaction solvent because a large cost is required for a recovery device for preventing external dissipation in order to keep it always below the above allowable concentration.

In addition, since alkylbenzenes have a significantly wide boiling point range, when the reaction mixture is distilled off under reduced pressure after recovery, there are many high boiling point residues, the recovery rate is low, and the operation is complicated. Moreover, when these residual solvents are mixed in even a little bit into the target copper phthalocyanines, when pigmented, a coloring power will fall and a hue will also fall.

MEANS TO SOLVE THE PROBLEM In the preparation of copper phthalocyanines by reacting phthalic anhydride or phthalimide, a copper compound, and urea in presence of a catalyst, the present inventors solved the fault which the conventionally used reaction solvent has, and made the target copper phthalocyanines high. As a result of various studies on reaction solvents to obtain high yield and high quality and to produce industrially advantageously without by-products of harmful substances, mono-monomer having at least one benzene core having an alkyl group having 1 to 3 carbon atoms Polyalkylmonochloro obtained by reacting chlorobenzene with an alkyl halide having 1 to 3 carbon atoms in the presence of Lewis acid (for example, anhydrous aluminum chloride or anhydrous iron trichloride) or by reacting an unsaturated hydrocarbon such as ethylene or propylene. Obtained by nuclear monochlorolation of benzene or alkylbenzenes having at least two alkyl groups having from 1 to 3 carbon atoms The polyalkyl monochloro benzene has the boiling point most suitable for the synthesis conditions of the above-mentioned copper phthalocyanines, very small difference from the dry point at the initial flow point, little distillation residue, and excellent thermal stability, and also toxic substances such as PCB It has high solubility with respect to the raw material used at the time of synthesis | combination of copper phthalocyanines without using by-products, and when such polyalkyl monochlorobenzene is used as a reaction solvent, the target copper phthalocyanines are high quality and high yield, In addition, the inventors have found that the present invention can be manufactured stably and efficiently in terms of environmental hygiene, and have completed the present invention.

That is, the method of the present invention is a general formula

(Wherein R ₁ and R ₂ represent a lower alkyl group having 1 to ₃ carbon atoms, and R ₃ represents a hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms)

In a polyalkyl monochlorobenzene having at least two lower alkyl groups represented by the above general formula, a phthalic anhydride or a phthalimide is reacted with the same compound and urea in the presence of a catalyst.

In the production method of the present invention, in the polyalkyl monochlorobenzene represented by the general formula (I), phthalic anhydride or phthalimide and the same compound and urea are 130 ° C to 280 ° C in the presence of a catalyst. Preferably, it is performed by heat-reacting at 160-250 degreeC for 2 to 8 hours, normal pressure, or pressurization.

The polyalkyl monochlorobenzene (I) used as the reaction solvent in the present invention can be industrially advantageously produced, for example, in the following manner. That is, in the presence of raw materials such as chlorotoluene, chlorochiylene, trimethylchlorobenzene, ethylchlorobenzene, diethylchlorobenzene, propylchlorobenzene or diprochlorobenzene, and 0.1 mol% or more of anhydrous aluminum chloride or anhydrous iron chloride. , By reacting an alkyl halide such as methyl chloride, ethyl chloride or propyl chloride at -20 ° to 70 ° C. under atmospheric pressure or pressure, a methyl group, ethyl group or propyl group can be easily substituted for the benzene core of the raw material. The position and number to be substituted in the nucleus can be selected according to the reaction conditions.

After completion of the reaction, the polyalkyl monochlorobenzene can be separated by distillation under reduced pressure. The thermal stability of the polyalkyl monochlorobenzene obtained in this way is absolutely stable in the production temperature conditions of the copper phthalocyanines, that is, in the temperature range of 130 ° C to 280 ° C. Nevertheless, among the polyalkyl monochlorobenzenes, polyalkyl monochlorobenzenes substituted with alkyl groups having 4 or more carbon atoms, for example, substituted polyalkyl monochlorobenzenes with isobutyl groups, exhibit significant thermal stability as the temperature increases in the above temperature range. Fall off. Therefore, in the method of the present invention, the alkyl group having at least two substitutions with the polyalkyl monochloro benzene nucleus used as the reaction solvent is particularly preferably an alkylbenzene having 1 to 3 carbon atoms as described above.

In addition, the polyalkyl monochlorobenzene (I) which is the reaction solvent of the present invention obtained in this way has a high solubility in phthalic anhydrides or phthalimides, copper compounds, urea, catalysts, and the like used as the reaction raw materials, and thus the raw materials are easy. It can be mixed smoothly so that the reaction can proceed smoothly.

Specific examples of the polyalkyl monochlorobenzene used in the method of the present invention are as follows.

In addition, the added number is referred to in the following synthesis examples and an Example.

As the copper compound used in the present invention, copper powder or copper chloride such as cuprous chloride or cupric chloride, or an organic acid such as copper acetate is used, and as a catalyst, molybdenum oxide, ammonium molybdate, boron oxide or tungsten are used. Oxides and the like are used.

According to such a method of the present invention, the target copper phthalocyanines can be produced in high quality and extremely industrially at a high yield of 90% or more.

Next, the features and advantages of the present invention will be described. First, polyalkyl monochlorobenzene (1), which is a reaction solvent used in the method of the present invention, has an optimum boiling point with respect to the preparation temperature conditions of the copper phthalocyanines of the present invention and is dissolved in the reaction raw material. It is excellent in capability and can produce the target copper phthalocyanines in high yield, and the manufacturing method of this invention is conventionally widely used, and the trichlorobenzene or nitrobenzene which the copper phthalocyanines of both quality is obtained is obtained. Compared with the manufacturing method used as a solvent, the copper phthalocyanine which is much excellent in the grade as a pigment is obtained. That is, prepared copper phthalocyanines as they are generally produced by the reaction are plate-like granules with a large particle size containing a by-product, so that the color tone is unclear and the coloring power is poor, so that they can be used as pigments. Since the preparation is dissolved or slurried with concentrated sulfuric acid, injected into a large amount of water, and reprecipitated to a fine state (referred to as an acid pasting method or an acid slurry method), α-type copper phthalocyanine is used, or the preparation is inorganic. Pigmentation as a beta-type phthalocyanine is common by mixing a salt etc. and grinding | pulverizing with a mechanical energy (called the salt grinding method).

Since the prepared copper phthalocyanines obtained by using conventional trichlorobenzene as a solvent have a large particle size (20 micrometers-50 micrometers) and plate shape as mentioned above, the dissolution time in concentrated sulfuric acid at the time of pigmentation by an acid pasting method The crystals of the crude copper phthalocyanine obtained by using the solvent of the present invention have a fine needle of 0.5 to 1.0 占 퐉, and are soft, because they usually require 5 to 10 hours. The slurrying time can be shortened significantly. Similarly, even in the salt grinding method, the crude copper phthalocyanines obtained by the present invention can shorten the grinding time. In addition, the quality of the pigment obtained as mentioned above is about 15- about the pigment | dye by the manufacturing method of this invention compared with the pigment from the preparation by the conventionally well-known manufacturing method about any of alpha type and a beta type. Coloring is high about 25% and color tone is clear.

Secondly, polyalkyl monochlorobenzene (I), which is a reaction solvent used in the method of the present invention, has the above-described characteristics and a relatively small boiling point range, and thus has a wide boiling range similar to that of alkylbenzenes conventionally used. Unlike the reaction solvent having, in the method of the present invention, since the solvent is easily recovered by the vacuum distillation method after the completion of the reaction, the solvent can be completed in a short time, and the thermal stability is excellent, and there is almost no residue, There is no deterioration in quality, such as contaminating the color tone of the pigment by the residue.

Third, polyalkyl monochlorobenzene (I), which is a reaction solvent used in the method of the present invention, is less toxic than nitrobenzene conventionally used as a reaction solvent, and, like trichlorobenzene, the largest environmental pollution source is Since it does not produce by-products such as PCB, by-products, according to the method of the present invention, it is possible to manufacture the desired copper phthalocyanines at all in terms of environmental hygiene.

The following example further illustrates the method of the present invention. Moreover, by the synthesis example, the manufacturing method of polyalkyl monochlorobenzene (I) which is a reaction solvent used by this invention is demonstrated concretely.

(Synthesis example 1)

1.12 g of anhydrous aluminum chloride was added to 152 g of 0-chlorotoluene, 94 g of isopropyl chlorides were added dropwise at 10 DEG C or lower under stirring, and the reaction was carried out at 10 DEG C for 5 hours after completion of dropping. After the completion of the reaction, the obtained reaction solution was washed with water, neutralized and washed with dilute caustic soda aqueous solution, washed with water again, distilled under reduced pressure, and distilled off unreacted 0-chlorotoluene to a boiling point of 110 to 112 DEG C / 20 mmHg. 162 g (yield 80.0%) of monoisopropyl-0-chlorotoluenes were obtained.

The obtained monoisopropyl-0-chlorotoluene was analyzed by gas chromatograph, and it was confirmed that it was an isomer mixture of 4-isopropyl-2-chlorotoluene and 5-isopropyl-2-chlorotoluene.

(Synthesis example 2)

1.12 g of anhydrous aluminum chloride was added to 152 g of P-chlorotoluene, 94 g of isopropyl chlorides were dripped at 10 degrees C or less under stirring, and it was made to react at 10 degreeC for 5 hours after completion | finish of dripping. After completion of the reaction, it was worked up in the same manner as in Synthesis example 1 to obtain 158 g (yield 78%) of monoisopropyl-P-chlorotoluene (5) having a boiling point of 77 to 78 ° C / 9 mmHg. The obtained monoisopropyl-P-chloro toluene was analyzed by gas chromatography, and it was confirmed that it is an isomer mixture of 2-isopropyl-4-chlorotoluene and 3-isopropyl-4-chlorotoluene.

Example 1

200 g of phthalic anhydride, 244 g of urea, 34 g of cuprous chloride and 0.4 g of ammonium molybdate were added to 350 g of mono isopropyl-0-chlorotoluene (3), and the mixture was heated and reacted at 200 DEG C for 3 hours under normal pressure.

After completion of the reaction, the monoisopropyl-0-chlorotoluene (3) as a solvent was distilled off from the reaction product by vacuum distillation, followed by hot water filtration, pickling filtration, washing with water and drying to prepare a purity of 98% or more. 183 g of copper phthalocyanine (yield 92%) was obtained.

This product is pigmented by an acid pasting method (PB report No. NO 85172, described in British Patent No. 502,623), and an α-type pigment is further described in each salt grinding method (US Pat. No. 2,486,304, 2,486,351). ) To obtain a β-type pigment. These α- and β-type pigments are each composed of the α- and β-type pigments obtained by pigmenting a crude copper phthalocyanine prepared by using a conventionally known trichlorobenzene as a reaction solvent in the same manner as described above. As a result of comparative testing by the pigment test method of 1964, the coloring power was 20-25% and the sharpness was also excellent.

In the same manner as in Example 1 described above, the experiment was performed by changing monoisopropyl-0-chlorotoluene (3) as a solvent into monoisopropyl-m-chlorotoluene (4) or monoisopropyl-P-chlorotoluene. In the same manner, a high quality copper phthalocyanine pigment was obtained in a yield of 90% or more.

Example 2

200 g of phthalimide, 204 g of urea, 34 g of cuprous chloride and 0.4 g of ammonium molybdate were added to 350 g of monoisopropyl-0-chlorotoluene (3), and the mixture was heated and reacted at 200 DEG C for 3 hours under normal pressure. After completion of the reaction, the monoisopropyl-0-chloro toluene (3) as a solvent was distilled off from the reaction product by distillation under reduced pressure, followed by hot washing filtration and pickling filtration, washing with water and drying to prepare a crude copper phthalocyanine having a purity of 98% or more. 189 g (yield 94%) was obtained.

This product was pigmented by the acid pasting method similarly to Example 1, and the (alpha) type pigment was pigmented by the salt grinding method, and the (beta) type pigment was obtained. All of these α- and β-type pigments were compared with α- and β-type pigments obtained by pigmenting crude copper phthalocyanine prepared using conventionally known trichlorobenzene as a reaction solvent in the same manner as described above. The coloring power was 20-25% large, and the sharpness was also excellent.

Example 3

200 g of phthalimide, 204 g of urea, 34 g of cuprous chloride and 0.4 g of ammonium molybdate were added to 350 g of [2,4,6-trimethyl-monochlorobenzene (7), and the resulting mixture was heated at 200 DEG C for 3 hours at atmospheric pressure. . After completion of the reaction, 2,4,6-trimethyl-monochlorobenzene (7) as a solvent was distilled off from the reaction product by distillation under reduced pressure, followed by hot washing filtration and pickling filtration, washing with water and drying to obtain a purity of not less than 97%. 178 g (90% yield) of prepared copper phthalocyanine was obtained.

In the same manner as in Example 1, the product was pigmented by the acid pasting method, and the α-type pigment was further pigmented by the salt grinding method to obtain a β-type pigment. All of these α- and β-type pigments have a coloring power when compared with α- and β-type pigments obtained by pigmentation of a crude copper phthalocyanine prepared using conventionally known trichlorobenzene as a reaction solvent by the same method as described above. This 15-20% was large and the sharpness was also excellent.

Example 4

200 g of phthalimide, 204 g of urea, 34 g of cuprous chloride and 0.4 g of ammonium molybdate are added to 350 g of 2,3,4,6-tetra methyl-monochlorobenzene (10) and at 230 캜 for 3 hours at atmospheric pressure. It reacted by heating. After completion of the reaction, 2,3,4,6-tetramethyl-monochlorobenzene (10) as a solvent was distilled off from the reaction product by vacuum distillation, followed by hot water filtration and pickling, washing with water and drying to obtain purity. More than 95% of prepared copper phthalocyanine 177g (yield 90%) was obtained.

This product was pigmented by the acid pasting method similarly to Example 1, and the (alpha) type pigment was pigmented by the salt grinding method, and the (beta) type pigment was obtained. These α- and β-type pigments are colored in comparison with the α- and β-type pigments obtained by pigmentation of crude copper phthalocyanine prepared by using a conventionally known trichlorobenzene as a reaction solvent by the same method as described above. This 15-20% was large and the sharpness was also excellent.

Example 5

200 g of phthalimide, 204 g of urea, 34 g of cuprous chloride and 0.4 g of ammonium molybdate were added to 350 g of monoisopropyl-0-chlorotoluene (3), and the mixture was pressurized at 2.5 kg / cm 2 G at 160 ° C. for 3 hours. It reacted by heating. After completion of the reaction, the monoisopropyl-0-chlorotoluene (3), which is a solvent, was distilled from the reaction product by distillation under reduced pressure, followed by hot water filtration and pickling filtration, washing with water and drying to obtain a purity of 98% or more. 194 g (97% yield) of phthalocyanine was obtained.

This product was pigmented by the acid pasting method similarly to Example 1, and the (alpha) type pigment was pigmented by the salt grinding method, and the (beta) type pigment was obtained. These α- and β-type pigments are 20-25% larger in colorability and sharper than the pigmented crude phthalocyanine prepared by using a conventionally known trichlorobenzene as a reaction solvent, respectively, in the same manner as described above. Excellent.

Claims (1)

General formula

(Wherein R ₁ and R ₂ represent a lower alkyl group having 1 to 3 carbon atoms, and R ₃ and R ₄ represent a hydrogen atom or a lower alkyl group having 1 to 3 carbon atoms) A method for producing copper phthalocyanines, comprising reacting phthalic anhydride or phthalimide with the same compound and urea in the presence of a catalyst in polyalkyl monochlorobenzene having at least two lower alkyl groups represented by the above general formula.