JPH10175978A - Purification of water-soluble matallophthalocynine compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To purify a water-soluble metallophtalocyanine by use of only heating and filter devices without the need of any complicated control by dissolving a crude water-soluble metallophtalocyanine product followed by treatment under specified conditions and then filtration. SOLUTION: A crude product of a water-soluble metallophthalocyanine compound of the formula (X is H or a water solubility-imparting group; M is a transition metal atom) is mixed with such amount of water as to be enough to dissolve the whole amount of the water-soluble metallophthalocyanine compound included in the crude product, the resultant solution is filtered, the filtrate is then boiled and then further filtered, thus purifying the water-soluble metallopthalocyanine compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for purifying a water-soluble metal phthalocyanine compound.

[0002]

2. Description of the Related Art Metal phthalocyanine compounds have long been known as synthetic organic dyes. When this metal phthalocyanine compound is used as a dye, the presence of impurities is not always an important problem. However, recently, the effect as a photoelectric conversion element and the deodorizing effect have been attracting attention, and the presence of impurities has become an important problem. this is,
This is because the optical and electrical properties of the metal phthalocyanine compound are greatly affected by trace impurities and the deodorizing action is also affected by purity. As a conventional method for synthesizing a metal phthalocyanine compound, a Wyler method carried out in the presence of a catalyst and a solvent method of reacting in a high boiling point solvent in the absence of a catalyst are mainly known (for example, , Meisei University Research Bulletin No. 26, P47-5
9, 1990, Tadanobu Sawada, "Synthesis and Properties of High Purity Phthalocyanines"). Of these, water-soluble metal phthalocyanine compounds are generally synthesized by the Weyler method. The Weyler method is a synthesis method in which phthalic acid or a derivative thereof, a metal salt, and molten urea are reacted in the presence of a catalyst. For example, when iron phthalocyanine tetrasulfonic acid, which is a typical water-soluble metal phthalocyanine compound, is synthesized by the Wyler method, 4-sulfophthalic acid, iron powder, urea, and a catalyst (for example, boric acid) are used as raw materials.
The whole is heated to about 230 ° C. to react.

[0003] One conventional method for purifying a crude product is described, for example, in Naomi Fukada, Vol. According to this method, the obtained crude solid is dissolved in water to remove insolubles, hydrochloric acid is added to the obtained aqueous solution to carry out salting out, and ammonia is added to the solid from which the supernatant is removed. The insolubles are removed, the ammonia is removed from the resulting ammonia solution by evaporation, and hydrochloric acid acidic saturated saline is added to remove the supernatant to obtain a solid with improved purity. Further, this solid is washed with an aqueous ethanol solution of 80% or more to remove salt, phthalimide and the like. However, this purification method is extremely complicated since it involves many steps. In addition, the insoluble substance formed by dissolving the crude solid in water and then adding hydrochloric acid is extremely fine, so that solid-liquid separation is difficult, and the odor due to hydrochloric acid and ammonia used generates odor. Rate is 10-2
There were many drawbacks, such as as low as 5%.

Further, Toyoda and Oda, Powder and Industrial Vol.
20, no. 9 (1988), a crude copper phthalocyanine compound was placed in an inert gas atmosphere such as helium.
Heat under reduced pressure to vaporize the copper phthalocyanine compound,
A purification method for recovering as fine particles is described. However, in this purification method, the vacuum pressure is 1 × 10 ⁻³ to 1 × 1.
It was difficult to treat a large amount of crude solids because the pressure was reduced to 0 ^-5 Torr and a step of removing ultrafine particles attached to the film was required.

Further, JP-A-6-220061 describes a method in which a crude product of a metal phthalocyanine compound is heated under reduced pressure at a temperature lower than the decomposition temperature to remove impurities. This dry purification method, instead of evaporating only the metal phthalocyanine compound from the crude product,
Conversely, the impurities contained in the crude product are evaporated or decomposed and evaporated to leave the metal phthalocyanine compound,
Purification is performed, and a relatively large amount of a crude metal phthalocyanine compound can be purified by a simple operation. However, in this method, the temperature, the pressure, and the processing time are delicately controlled, so that the apparatus becomes complicated, and a gas such as ammonia derived from decomposition of impurities is generated. Was also needed.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to eliminate the need for a complicated washing step which is a drawback of the conventional washing and purifying method, namely, acid washing, alkali washing and ethanol washing. It is an object of the present invention to provide a method capable of purifying a large amount of a crude product without the need for delicate control, which is a drawback of the conventional dry purification method.

[0007]

An object of the present invention is to provide a crude product of a water-soluble metal phthalocyanine compound according to the present invention and a sufficient amount of the water-soluble metal phthalocyanine compound contained in the crude product. The method for purifying the water-soluble metal phthalocyanine compound, further comprising the steps of: mixing the water-soluble metal phthalocyanine compound with a water-soluble metal phthalocyanine compound; Can be solved by

[0008]

The process of the present invention is particularly suitable for purifying a crude water-soluble metal phthalocyanine compound prepared by the Weyler method. As used herein, the “Wyler method” means a synthesis method in which phthalic acid or a derivative thereof, a metal salt, and a catalyst urea are reacted in the presence of a catalyst.

The crude metal phthalocyanine compound prepared by the above-mentioned Weyler method using molten urea is not only a target metal phthalocyanine compound but also unreacted phthalic acid and urea derivatives (for example, biuret or cyanuric acid) as impurities. It contains a phthalic acid derivative (eg, phthalimide) and a catalyst (eg, boric acid, ammonium molybdate or titanium tetrachloride). In the present specification, a crude product of a metal phthalocyanine compound refers to a crude reaction product obtained by binding a metal or a metal salt to sulfophthalic acid or the like, or a crude reaction product thereof in producing a metal phthalocyanine compound. Means a product with a low degree of purification, such as a product from which metal salts are mainly removed.
According to the method of the present invention, these impurities can be sequentially and efficiently removed.

The water-soluble metal phthalocyanine compound to be purified in the present invention is preferably a compound represented by the general formula (I)

Embedded image (Wherein each X is independently a group that imparts water solubility under neutral or acidic conditions or a hydrogen atom, and at least one of X is a group that imparts water solubility under neutral or acidic conditions. And M is a transition metal atom).

The metal phthalocyanine compound represented by the general formula (I) is a transition metal ion such as divalent iron ion, trivalent cobalt ion, pentavalent vanadium ion, or divalent manganese ion as an intermediate ligand. , Divalent copper, 2
Contains zinc, or two nickels. Further, the metal phthalocyanine compound represented by the general formula (I) contains at least one group X that imparts water solubility under neutral or acidic conditions (hereinafter, may be simply referred to as a water solubility imparting group X). . Examples of the water-solubility-imparting group X include, for example, an amino group, a halogen atom (for example, a chlorine atom or a bromine atom), a sulfochloride group or a sulfonamide group, preferably a sulfonic acid group. As the metal phthalocyanine compound represented by the general formula (I), a compound having four sulfonic acid groups (preferably one sulfonic acid group on each benzene ring) can be easily synthesized at low cost. It is often synthesized because it can be formed, and is a representative compound to be treated by the method of the present invention.

According to the method of the present invention, a crude product of any water-soluble metal phthalocyanine compound, particularly a crude product of a water-soluble metal phthalocyanine compound by the Wyler method can be purified. However, treating crude products that are substantially free of water-soluble unreacted reactants, particularly unreacted starting materials (eg, water-soluble phthalic acid derivatives, eg, sulfophthalic acid), in the crude product is advantageous. preferable. The crude product, which is substantially free of water-soluble unreacted starting materials,
For example, the mixing ratio of phthalic acid or a derivative thereof (for example, sulfophthalic acid) and urea used in the synthesis process by the Weyler method is set to 1 mole of phthalic acid or a derivative thereof.
Urea can be obtained by using preferably 5 mol or more, more preferably 9 mol or more.

When the amount of urea used per mole of phthalic acid or a derivative thereof is 9 moles or more, phthalic acid or a derivative thereof does not remain in the crude product. Further, a trace amount of a water-soluble unreacted starting material contained in a crude product is mixed, for example, by adding about 15 to 20 times by volume of ethanol to a dilute (about 0.5 to 5%) aqueous solution of the crude product. By filtering after boiling, it can be completely separated from the water-soluble metal phthalocyanine compound. When the amount of urea used per mole of phthalic acid or a derivative thereof is 10 moles or more, a urea derivative (eg, cyanuric acid or biuret) in a crude product is obtained.
However, since these urea derivatives are insoluble or poorly soluble in water, they can be easily separated from the water-soluble metal phthalocyanine compound in the purification step described later in the method of the present invention. Therefore, there is no upper limit of the amount of urea used in terms of the degree of purification of the crude product, but if the amount of urea used is at least 15 moles per mole of phthalic acid or a derivative thereof, the amount of urea derivative will increase too much, resulting in cost reduction. This is not desirable in terms of point.

The crude product containing substantially no water-soluble unreacted starting material can be more efficiently prepared, for example, by appropriately adjusting the reaction temperature and the reaction time in the synthesis process by the Weyler method. Obtainable. For example, phthalic acid or a derivative thereof (for example, sulfophthalic acid), urea, a metal (for example, iron powder) or a metal salt,
The mixture with the catalyst (eg, boric acid) is heated from room temperature to 90-110 ° C. over 1-3 hours,
The reaction is performed at 30 ° C. for 2 to 6 hours. During this reaction, any water components contained in the starting materials evaporate. Furthermore, 110-130 ° C. lower than the urea decomposition temperature (about 130 ° C.)
For 2 to 12 hours. If the reaction time is short, unreacted starting materials remain. Conversely, if the reaction time is too long, the reactants increase in viscosity, and the reaction process ends in an unreacted state with the starting material attached to the upper wall surface of the reaction vessel.

Then, from a temperature lower than the urea decomposition temperature,
The reaction is performed while heating to 140 to 180 ° C., which is higher than the urea decomposition temperature, for 2 to 10 hours. In this heating operation,
It is preferable to adjust the temperature rise rate so that a large amount of ammonia is not released out of the system. Furthermore, a temperature higher than the phthalocyanine ring formation temperature (about 190 ° C.) (eg, 195
(About 230 ° C.) for 1 to 4 hours. 190
Since an endothermic reaction occurs around ℃, it is preferable to control the temperature so that the calorific value does not become insufficient. Then, 220-2
At 30 ° C., the reactants become solids and a stirrer cannot be used. In this state, in order to sufficiently react the whole solid, it is heated at 220 to 230 ° C. for 4 to 15 hours. Thus, a crude product substantially free of water-soluble unreacted starting materials can be obtained by the Wyler method. The thus obtained crude product can be purified by the method of the present invention.

Generally, in the final step of the synthesis by the Weyler method, a heating operation at a temperature of 200 ° C. or higher is usually performed for a relatively long time, so that the crude product is obtained as a solid in a high temperature state. Therefore, before performing the first dissolution step in the purification method of the present invention, the crude product in the reaction vessel is preferably cooled to, for example, cooling water, preferably to 100 ° C. or lower, more preferably 90 ° C. or lower. . If the dissolving step described below is carried out at 100 ° C. or higher, the urea polymer contained as an impurity in the crude product is hydrolyzed, and the amount of ammonia dissolved in the aqueous solution may be undesirably increased.

In the purification method of the present invention, a dissolving step is first performed. In this dissolving step, the above-mentioned crude product is mixed with water to obtain an aqueous solution (solution) in which all of the water-soluble metal phthalocyanine compounds contained in the crude product are completely dissolved. This step can be carried out by removing the crude product from the reaction vessel and inserting it into water in another container, but is preferably carried out by adding water to the reaction vessel in which the synthesis of the crude product was performed. You can also. This dissolving step is preferably performed at a temperature of 50 to 70 ° C. in order to promote the dissolution of the water-soluble metal phthalocyanine compound in water. Further, if the mixture is left at the above-mentioned temperature, the dissolution gradually proceeds to such an extent that a stirrer can be used. Therefore, if the stirring is performed, the dissolution can be further promoted.

In this dissolving step, the main purpose is to dissolve all the water-soluble metal phthalocyanine compounds contained in the crude product in water, and the amount of water used sufficiently fulfills the purpose. There is no particular upper limit as long as it is at least the amount that can be used. However, if the amount of water is too large, the amount of dissolved hardly water-soluble impurities (for example, boric acid used as a catalyst, or a urea derivative such as cyanuric acid or biuret) increases, and the final purification degree decreases. Therefore, it is preferable to use an amount of water that completely dissolves the water-soluble metal phthalocyanine compound and that does not dissolve the hardly water-soluble impurities as much as possible. The appropriate amount of water is preferably as small as possible in order to reduce the time required for the subsequent filtration step and boiling step and to reduce the heating energy when evaporating ammonia.

When the dissolving step is carried out under heating, the aqueous solution of the water-soluble metal phthalocyanine compound (dissolving solution) obtained in the dissolving step is heated to about room temperature between the dissolving step and the subsequent filtering step. It is preferable to carry out a cooling step of cooling to a temperature of up to. The cooling can be performed, for example, by leaving the aqueous solution indoors. By gradually cooling the solution, the hardly water-soluble impurities dissolved in the solution are precipitated as large crystals, and the filtration step described below can be efficiently performed.

In the purification method according to the present invention, after performing the above-mentioned dissolving step and, if necessary, the cooling step, a filtering step of the dissolved liquid is performed. The filtration step can be carried out by passing the above-mentioned solution through a normal filter paper or filter cloth.However, first, the supernatant of the solution is separated, and the precipitate-containing solution is passed through a filter paper. Is preferred. By this filtration step, cyanuric acid crystals or boric acid crystals precipitated from the solution or impurities not dissolved in the solution (for example, phthalic acid derivatives, iron powder or iron hydroxide) are filtered (or supernatant solution). And filtrate).

Subsequently, the filtered solution obtained in the above-mentioned filtration step (ie, a filtrate or a mixture of a supernatant and a filtrate)
Boil. This boiling step is carried out under stirring for 100 to 10 minutes.
It is preferably carried out at 5 ° C. In addition, since water evaporates due to the boiling operation, it is preferable to appropriately supply water to maintain the amount of water in the container constant. By this boiling step, residual urea polymer not removed in the filtration step can be hydrolyzed and volatilized as ammonia. When the residual urea polymer (particularly, cyanuric acid) is hydrolyzed and volatilized as ammonia, the pH of the reaction solution is acidified, so that the end point of the boiling operation can be confirmed. Generally, the boiling operation can be terminated when the pH reaches 4 to 6.

Next, the boiled solution is again allowed to stand at room temperature,
By cooling as slowly as possible to room temperature, precipitated impurities (for example, phthalimide, iron hydroxide, or boric acid) can be removed by a second filtration operation.

[0023]

EXAMPLES The present invention will be described below in more detail with reference to examples, but these examples do not limit the scope of the present invention.

Example 1 (1) Preparation of crude product of iron phthalocyanine tetrasulfonic acid 23 kg of 50% aqueous solution of 4-sulfophthalic acid, 25 k of urea
g, 0.5 kg of electrolytic iron powder and 0.5 kg of boric acid
It was inserted into a 0 liter reactor. As the reaction tank, a reaction tank made of stainless steel (SUS304) and provided with a stirrer, a circulating oil bath and a temperature automatic controller was used. When gradually heated from room temperature to about 120 ° C. under stirring for about 6 hours, water was completely evaporated by the time the temperature reached about 120 ° C. Further, the mixture is stirred at about 120 ° C. for about 4 hours, and then gradually stirred at about 225 ° C. for about 7 hours.
When it reached about 225 ° C., the reaction mixture became a solid when it reached about 225 ° C. and the stirrer could no longer be used. When the reaction was continued for about 7 hours in this state, 11.0 kg of solid iron phthalocyanine tetrasulfonic acid crude product remained in the reaction tank.

(2) Purification of Crude Iron Phthalocyanine Tetrasulfonic Acid Product 11.0 kg of the solid crude iron phthalocyanine tetrasulfonic acid obtained in the above (1) is cooled to 100 ° C. or less in a cooling water in the reactor. And half the amount (about 50
Liters of water. When left at 60 ° C for 2 hours,
Dissolved to the extent that a stirrer could be used. Thereafter, the mixture was stirred at this temperature for 2 hours. Then, when allowed to stand still at room temperature and cooled to room temperature, cyanuric acid and boric acid were precipitated. After removing the supernatant, the mixture was filtered, the supernatant was combined with the filtrate, and the mixture was boiled at 105 ° C.
Boiling continued for hours. At the time of boiling, the amount of liquid was monitored, and water corresponding to the amount of evaporating water was supplied to keep the amount of liquid in the reaction tank constant at about 50 liters. Subsequently, the obtained liquid was allowed to stand at room temperature and cooled to room temperature, and then the precipitated impurities were removed by filtration. Thus, 60 kg of a 15% aqueous solution of iron phthalocyanine tetrasulfonic acid was obtained. The yield (purified solid / crude solid) was 82%. The concentration of the obtained aqueous solution of purified iron phthalocyanine tetrasulfonic acid was measured with a spectrophotometer.

[0025]

According to the method of the present invention, a crude product obtained by the Weyler method having a relatively high impurity content can be purified to an extremely high purity. In addition, the purification yield is 20 to 30% in the conventional wet method (method of performing acid precipitation, alkali washing, and ethanol washing), but reaches 80 to 90% in the method of the present invention. Further, a large amount of crude product can be treated at one time as compared with the conventional dry purification method. Furthermore, purification can be performed only by the heating device and the filtration device, and the cost of the device can be significantly reduced. In addition, the control of each operation is extremely simple and does not require complicated control, so that workability is improved and purification cost is significantly reduced.

Claims (1)

[Claims] 1. A solution obtained by mixing a crude product of a water-soluble metal phthalocyanine compound and water in an amount sufficient to dissolve the whole amount of the water-soluble metal phthalocyanine compound contained in the crude product. The method for purifying the water-soluble metal phthalocyanine compound, comprising filtering the solution, boiling the obtained filtered solution, and further filtering the boiling solution.