JPH0321669A - Production of beta type titanylphthalocyanine - Google Patents

Abstract

PURPOSE:To obtain the title high-purity compound by a simple device in a short time by reacting phthalodinitrile with titanium tetrachloride in an alcohol- based solvent in the presence of a proton transfer type reaction promoter by heating under reflux. CONSTITUTION:Phthalodinitrile shown by the formula is reacted with titanium tetrachloride in the molar ratio of preferably (1/4)-(1/2) in an alcohol-based solvent (one having preferably 100-150 deg.C boiling point, such as n-amyl alcohol) in the presence of preferably 1.0-1.2mol (based on 1mol phthalodinitrile) proton transfer type reaction promoter (e.g. 1,8-diazabicyclo[5,4,0]unde-7-cene) by heating under reflux to give the aimed compound.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing titanyl phthalonanine having a β-type crystal form.

(Prior Art) Metal phthalocyanines are used in pigments, dyes, leading conductive elements of electrophotographic photoreceptors, and the like. Recently, it has also attracted attention as a functional dye (functional molecule) such as a catalyst, electron, and energy converter.

Conventionally, titanyl phthalocyanine, which is a type of metal phthalocyanine, is produced by subjecting a mixture of titanium dinitrile and titanium tetrachloride to a heating reaction at high temperature in the presence of an aromatic inert high-boiling solvent.

However, titanyl phthalocyanine obtained by this method contains a large amount of by-products due to the reaction at high temperatures, the particles become coarse and lumpy solids, and the crystal form is a mixture of α and β types. There are some. Therefore, as it is, it cannot be used for practical purposes as a pigment, so it is usually subjected to a pigmentation treatment using sulfuric acid, such as an acid paste method, or a pigmentation treatment using mechanical grinding.

However, in the case of pigmentation treatment using sulfuric acid, a large amount of sulfuric acid is required, and the wastewater treatment thereof has many problems in terms of pollution, and in the case of pigmentation treatment by mechanical grinding, there is a problem that a great deal of labor is required.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing highly pure β-type titanyl phthalocanoanine without performing conventional pigmentation treatment.

(Means for Solving the Problems) In order to achieve the above object, it has been discovered that excellent results can be achieved by carrying out the reaction under specific reaction conditions, and the present invention has been completed.

That is, the present invention provides a method for producing β-type titanyl phtacyanine, which comprises heating and refluxing phthalodinitrile and titanium tetrachloride in an alcoholic solvent in the presence of a proton-transfer type reaction accelerator.

The β-type titanyl phthalocyanine of the present invention is easily produced by reacting phthalodinitrile with titanium tetrachloride under the above reaction conditions and then hydrolyzing it. This reaction is represented by the reaction formula below.

Alcohol solvent, reflux (in the above reaction formula, P represents a phthalocyanine residue). /2 mol is preferable. If it is outside this range, the yield will decrease and mackerel production will become difficult, which is not preferable.

The above reaction is carried out in an alcoholic solvent. The alcoholic solvent used has a boiling point of 70°C or higher, preferably +00-150°C.

Specific examples of such alcohols include n-amyl alcohol, n-hexyl alcohol, l-methoxyethanol, l-ethoxyethanol, and the like.

The amount of the alcoholic solvent to be used is not particularly limited as long as the reaction can be carried out uniformly, but specifically, for example, 200 to 500 x
It is Q.

It should be noted that if the above reaction is carried out using a solvent other than an alcoholic solvent, for example, a high-boiling aromatic organic solvent such as 0-promonaphthalene or quinoline, which has been commonly used in the past, a large number of decomposed products will be produced, which will complicate the purification process. Not achieved.

Further, the above reaction is carried out in the presence of a proton transfer type reaction accelerator. It is thought that the proton transfer-accepting reaction accelerator referred to in the present invention acts on the alcohol used as a solvent to extract protons. The resulting alkoxide acts on the cyano group of phthalononitrile, increasing the electron density of the nitrogen atom of the cyano group, and as a result, phthalodinitrile! ．． It is presumed that the condensation reaction is promoted via a 3-diiminoisoindoline-like skeleton to form a tetraazaborphyrin skeleton.

Specific examples of such reaction promoters include 1.
8-diazabicyclo[5,4.0]unde7-cene(
DBU), 1,5-diazabicyclo[4.3.0]
-5-nonene (DBS) and the like. Further, the amount of the reaction accelerator used is a stoichiometric amount or more, preferably 1.0 to 1.2 mol, per 1 mol of phthalodinitrile. l
．． If it is less than 0 mol, the reaction will not be completed, and if it is more than 1.2 mol, the effect of promoting the reaction will not increase and it will be uneconomical.

The above reaction method is carried out by slowly dropping a proton transfer type reaction accelerator into a mixture of phthalodinitrile, titanium tetrachloride, and an alcoholic solvent under heating and refluxing, followed by stirring under reflux. By carrying out the reaction under reflux, the particles that are gradually generated become finer, reducing the effort of further converting the compound into a pigment according to this production method, and reducing o. p. It is possible to obtain the target compound which is subjected to, for example, c. The reaction time is not particularly limited, but is, for example, 6 to 10 hours. The reaction temperature is reflux temperature, that is, 70 to 160°C, preferably 100°C.
~150°C. If it is lower than 70°C, the yield will decrease, and if it is higher than 160°C, the product will decompose and by-products will be produced, which is not preferable.

Next, the dichlorotitanium phthalocyanine obtained in the above reaction is dispersed in an acidic aqueous solution, for example, an aqueous hydrochloric acid solution, and is hydrolyzed by stirring. The reaction temperature and time are not particularly limited, and may be, for example, at room temperature for 1 to 3 hours. Further, the concentration and amount of the acidic water solution used is, for example, 3 to 5% concentration,
30 per part by weight of dichlorotitanium phthalocyanine
It may be ~50ytQ.

After the reaction is completed, the hydrolyzed product is collected by filtration, and the filtrate is
Wash with water until { is 6 or more to obtain crude titanyl phtacyanine.

Next, the proto-titanyl phthalocyanine is added to a heated solvent such as dimethylformamide (DMF) and heat-treated. The heating temperature is preferably 100 to 120°C. By heat treatment, the α-type crystals partially mixed in the β-type crystals are converted into thermodynamically more stable β-type crystals, and titanyl phthalocyanine containing only pure β-type crystals is obtained.

(Effects of the Invention) According to the present invention, since phthalodinitrile and titanium tetrachloride are directly reacted in an alcohol solvent at a relatively low temperature, a fine compound without contamination with impurities can be obtained. Moreover, since conventional pigmentation treatment is not required, the production method and equipment are simple, and the process time is extremely short, making it possible to produce titanyl phtacyanine having only a highly pure β-type crystal form. Furthermore, even when the titanyl phthalocyanine obtained by the method of the present invention is used as a charge generating agent for an electrophotographic photoreceptor, it may be difficult to use due to instability of physical properties of a mixture of different crystal forms, transition of crystal forms due to heat, etc. Avoid causing various troubles.

(Examples) The present invention will be explained in more detail by Examples below, but the present invention is not limited to these Examples.

Example! In a mixture of 76.29 (approximately 0.6 mol) phthalodinitrile, 56.49 (approximately 0.3 mol) titanium tetrachloride, and 200 l12 n-amyl alcohol, 1.
8-diazabisikku [5, 4.0] unday 7 sen 91
．． 89 (approximately 0.6 mol) was added dropwise over approximately 1 hour, and the mixture was further stirred under heating and reflux for 6 hours. After the reaction was completed, it was left to cool to 100°C, about 30xQ of water was added, and after stirring for a while, the reaction product was collected by filtration and dimethylformamide 100+ (,
Next, methanol 100xQ was sprinkled on the plate for washing. The obtained dichlorotitanium phthalocyanine was dissolved in 1 part of 3% hydrochloric acid water.
After dispersing in 000xf2 and stirring for 1 hour, it was filtered and fractionated, and the pH was 6 or higher (electrical conductivity was 20 μS/ax or lower).
I washed it with water until it was This water-moist cake is then poured with dimethylformamide, preheated to 100-120° C.
After stirring at this temperature for about 1 hour, it was filtered while hot. The resulting dimethylformamide wet cake was replaced with 100 x l of methanol and dried at 90°C for 2 days to give a blue solid 29.19 This was subjected to elemental analysis and diffraction X-ray analysis.The results are shown in Table 1 and Figure 1, respectively.These results indicate that this compound is a ditanyl phthalocyanine having a β-type crystal form. It turns out.

Table 1 Examples 2 to 4 Alcohol solvent and proton transfer type reaction accelerator
Synthesis was carried out in the same manner as in Example 1, except for the changes shown in the table. The synthesis results are shown in Table 2.

Table 2

[Brief explanation of the drawing]

FIG. 1 shows an X-ray diffraction spectrum of the titanyl phthalocyanine compound obtained in Example 1. The vertical axis is the diffraction intensity,
The horizontal axis represents the diffraction angle 2θ. Diffraction angle (2θ)9.2”
, 1 0.3°, 20.6°, 26.1', 27.
It has a characteristic strong diffraction peak at 0°.

Claims (1)

[Claims] 1. A method for producing β-type titanyl phthalocyanine, which comprises heating and refluxing phthalodinitrile and titanium tetrachloride in an alcoholic solvent in the presence of a proton-accepting reaction promoter.