JP4696937B2 - Method for producing dichloroquinacridone pigment - Google Patents

Description

  The present invention relates to a method for producing a yellowish red and transparent dichloroquinacridone pigment which is light and environmentally friendly and has a light load on waste solvent treatment or recovery and reuse.

  C. I. Red dichloroquinacridone pigments such as Pigment Red 209 are well known. Such a dichloroquinacridone pigment is obtained by cyclizing 2,5-di- (3-chloroanilino) terephthalic acid or the like in polyphosphoric acid to hydrolyze it into a dichloroquinacridone compound (crude pigment), which is then converted into an organic solvent. It is manufactured by performing a finishing treatment so that it can be used as a colorant, such as heating in the inside (see Patent Document 1).

  Di (chloroanilino) terephthalic acid used as an intermediate for cyclization includes C.I. I. In addition to 2,5-di- (3-chloroanilino) terephthalic acid, which is the main intermediate of Pigment Red 209, some compounds having similar chemical structures may be contained in relatively large amounts. The dichloroquinacridone compound prepared according to a known production method from an intermediate mixture containing similar compounds was bluish red.

  In addition, the dichloroquinacridone compound is subjected to a finishing treatment for adjusting the crystal particle diameter and the shape thereof by heating and stirring in a polar organic solvent such as N, N-dimethylformamide and N-methyl-2-pyrrolidone. And dichloroquinacridone pigments. However, this method mainly results in an opaque bluish red pigment. There is theoretically a method of finishing the target yellowish red and transparent pigment, but excessive trial and error is required for setting the conditions.

  In addition, since this finishing process requires a large amount of the polar organic solvent as described above, and it takes time and effort for waste solvent processing or recovery and reuse, an environmentally friendly finishing process is required.

  In this way, the dichloroquinacridone pigment obtained by the conventional production method is bluish red and opaque, and after all, it is light in burden of waste solvent treatment or recovery and is environmentally friendly, yellowish red and transparent. A method for producing a dichloroquinacridone pigment has not been known.

JP 2000-38521 A

  It is an object of the present invention to provide a method for producing a yellowish red and transparent dichloroquinacridone pigment that is lightly loaded with waste solvent treatment or recovered and reused and is friendly to the environment.

  Although the present inventors are in a very limited range, as a method for producing a dichloroquinacridone pigment, using a high-purity intermediate, cyclizing it in polyphosphoric acid at a specific concentration or more, and an organic solvent It has been found that the above-mentioned problem can be solved by including a step of heating a solid substance substantially in water so that it contains no or only a small amount, and the present invention has been completed.

That is, the present invention has a purity of 96% or more of 2,5-di - (3-chloroanilino) 1 parts of terephthalic acid, phosphoric acid content anhydride is cyclized in 3-10 parts of above 85 wt% polyphosphoric acid, to give The obtained cyclization reaction liquid is hydrolyzed by mixing with 2 to 20 parts of water equivalent to 1 part of the cyclization reaction liquid in terms of mass , and then filtered to heat the solid content in water. Provided is a method for producing a characterized dichloroquinacridone pigment.

  The production method of the present invention includes a step of cyclization in a polyphosphoric acid having a specific concentration or more using a purified intermediate, so that a dichloroquinacridone compound having only a target crystal form can be reliably obtained without waiting for a finishing treatment. As a result, a yellowish red dichloroquinacridone compound can be easily obtained, and a finishing treatment can be carried out with or without the use of a small amount of a conventional polar organic solvent. It has a particularly remarkable effect that it can be manufactured friendly to the environment.

  The present invention precipitates a dichloroquinacridone compound by cyclizing and hydrolyzing 2,5-di- (3-chloroanilino) terephthalic acid having a purity of 96% or more in polyphosphoric acid having a phosphoric anhydride content of 85% by mass or more. And a second step of finishing the dichloroquinacridone compound obtained in the first step in water to obtain a dichloroquinacridone pigment.

  The dichloroquinacridone pigment to be obtained by the production method of the present invention exhibits a desired yellowish red color. Such a dichloroquinacridone pigment has specific peaks mainly at Bragg angles 2θ (± 0.2 °) = 5.8 °, 11.8 °, 12.9 °, 24.2 ° and 26.3 ° in X-ray diffraction measurement by CuKα ray. On the other hand, dichloroquinacridone pigments which are not desired to be produced by the production method of the present invention have specific peaks mainly at Bragg angles 2θ (± 0.2 °) = 5.3 °, 15.0 ° and 27.7 °. Therefore, as described below, in the present invention, for example, conditions are selected so that phosphoric anhydride at the time of cyclization exceeds a specific concentration so that dichloroquinacridone that is not desired to be produced as a crude pigment or as a pigment is not produced. That is why.

  The purity of 2,5-di- (3-chloroanilino) terephthalic acid that can be used in the present invention is required to be 96% or more. The purity of this 2,5-di- (3-chloroanilino) terephthalic acid can be easily calculated from the peak area ratio of the chromatogram obtained by high performance liquid chromatography measurement. For example, 2,5-di- (3-chloroanilino) in which the total amount of impurities such as 2,5-dianilinoterephthalic acid and 2-anilino-5- (3-chloroanilino) terephthalic acid exceeds 4%. Since the hue of dichloroquinacridone pigments is bluish by quinacridone compounds (for example, unsubstituted quinacridone) produced by cyclization of these impurities, terephthalic acid is not suitable for application to the method for producing a yellowish red pigment in the present invention. Inappropriate.

  The polyphosphoric acid used in the first step of the present invention may be prepared by a known and commonly used method. For example, it can be prepared from hydrous phosphoric acid and anhydrous phosphoric acid. Specifically, it can be prepared by adding phosphoric anhydride to phosphoric acid having a concentration of 80% by mass or more and stirring. The phosphoric anhydride content of the polyphosphoric acid used in the present invention is 85% by mass or more, particularly preferably 85 to 90% by mass, which corresponds to a phosphoric acid content of 117 to 124% by mass. The amount used is 3 to 10 parts by weight in terms of 1 part of 2,5-di- (3-chloroanilino) terephthalic acid. This polyphosphoric acid concentration is an important factor for obtaining the target yellowish red pigment, and is obtained by hydrolyzing cyclized polyphosphoric acid having a phosphoric anhydride content of 85% by mass or less. In the quinacridone compound, crystals having a form different from the intended yellowish red pigment are also produced. The generation of this different crystal form can be easily confirmed from the Bragg angle at which a specific peak appears by X-ray diffraction measurement. When these different crystal forms are mixed, the hue of the dichloroquinacridone pigment is bluish red, and the yellowish red pigment that is the final target cannot be obtained.

  In cyclization reaction of 2,5-di- (3-chloroanilino) terephthalic acid, 2,5-di- (3-chloroanilino) terephthalic acid is added to polyphosphoric acid, and 80 to 150 ° C., particularly preferably 100 A cyclization reaction solution containing a dichloroquinacridone compound can be obtained by stirring the reaction solution at ˜130 ° C. for 1 to 10 hours.

  In the hydrolysis in the first step of the present invention, the cyclization reaction solution obtained by the above method is mixed with a large excess of water equivalent to 2 to 20 parts relative to 1 part of the cyclization reaction solution in terms of mass. Can be done. For this mixing, it is preferable to add the cyclization reaction liquid with stirring of water. This hydrolysis can be performed by stirring at 0 to 100 ° C. for 0.1 to 5 hours. Most preferably, it is 0.1 to 2 hours at 10 to 50 ° C. In the production method of the present invention, after the hydrolysis is completed, the reaction solution is filtered and this solid content is applied to the second step. A wet cake of a dichloroquinacridone compound can be obtained by separating the crystal particles precipitated by hydrolysis. The compound thus obtained does not have a function as a colorant as it is, is a fine and highly aggregated material with a low crystallinity, and is also referred to as a crude pigment or crude.

  The wet cake of the dichloroquinacridone compound may be used in the second step as it is, but it is more preferable to use it after washing because the polyphosphoric acid used in the first step can be completely removed. This washing is preferably performed 1 to 5 times using 2 to 20 parts of a large excess of water, hot water or the like with respect to 1 part of the solid content of the wet cake of the dichloroquinacridone compound in terms of mass. Similarly, the wet cake of the dichloroquinacridone compound is added to 2 to 20 parts of water, hot water, etc. in terms of mass, and the mixture can be washed by stirring and filtering.

  In addition, it is preferable to perform the second step without completely removing the polyphosphoric acid because, for example, neutralization with a base or the like is necessary later, or a separate preparation of a base is necessary, which is uneconomical and increases the number of steps. Absent.

  In addition, the dichloroquinacridone compound obtained by drying the wet cake may be used in the second step. However, in the second step, the dichloroquinacridone compound obtained in the first step is heated in water. The quinacridone compound is usually supplied to the second step as it is in a wet cake containing water from the viewpoint of quality improvement, process shortening, and productivity improvement.

  The second step of the present invention is characterized in that the dichloroquinacridone compound obtained in the first step is heated in water and subjected to a finishing treatment to obtain a dichloroquinacridone pigment. This finishing treatment can be usually performed by stirring while heating water containing a dichloroquinacridone compound.

  The amount of water used in the second step is 3 to 20 parts, including water in the wet cake, with respect to 1 part in solid equivalent of the dichloroquinacridone compound in the wet cake in terms of mass.

  The heating temperature in the second step is 50 to 200 ° C., particularly preferably 80 to 150 ° C., and the stirring time is 0.5 to 15 hours, particularly preferably 2 to 10 hours. If necessary, heat treatment may be performed under pressure.

  In this finishing treatment, stirring with a stirring blade is preferable. In addition, there is no need for separate preparation of grinding media, it is economical, and there is no deterioration in pigment quality due to contamination of crushed media, and generation of fine particles that affect application properties such as viscosity and light resistance. In terms of reduction, it is preferable that the dichloroquinacridone compound is not pulverized.

  In the present invention, the pigment can be obtained by heat treatment with water alone, but an organic solvent may be used in combination as necessary in order to further increase the crystallinity. As the organic solvent, those which are slower in crystal growth and easier to prevent the generation of different crystals and to control the particle diameter and shape are preferable. In the present invention, it is preferable to use water containing aliphatic alcohols. Examples of aliphatic alcohols that can be used at this time include 1 carbon atom such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, pentanol, hexanol, cyclohexanol, and ethylene glycol. -8 monoalcohols or dialcohols. Nitrogen-containing organic solvents such as dimethylformamide and N-methyl-2-pyrrolidone have a sharp crystal change compared to the above-mentioned aliphatic alcohols, and the waste solvent treatment is troublesome and expensive per se. Therefore, it is not preferable.

  The water used in the second step is particularly preferably water containing 20% by mass or less of aliphatic alcohol. By controlling the content of aliphatic alcohols relative to water to 20% or less, it becomes possible to appropriately control crystals, and compared to water alone or aliphatic alcohols alone, the occurrence of different crystals is prevented and the particle size and shape are reduced. Can be controlled more easily. If it exceeds 20%, mixing of different crystals increases, and it is easy to shift from the intended hue.

  In addition, for the purpose of further improving the properties of the dispersion when dispersed in the coloring medium, at least one compound selected from the quinacridone derivatives represented by the following formula, if necessary, in any step in the production method of the present invention: It can also be added. The addition time may be before or after the heat treatment in the second step or at the same time. The amount used is 0.005 to 0.1 part in terms of mass with respect to 1 part of the dichloroquinacridone compound.

(In the formula, X is F, Br, I, —OH, —NO ₂ , C ₁ -C ₄ alkyl group, C ₁ -C ₄ alkoxy group, phenyl group, —COOH, —COO—C substituted with hydrogen. ₁ -C _{4 alkyl, -SO 3 H, -SO 3 M} , -SO 2 NH 2, -SO 2 -NH- (CH 2) 3 -N (CH 3) 2, - (SO 2 -NH) 2 - _{(CH 2) 3 -N (CH} 3) 2, -N (CH 3) 2, -NH 2, -NH-CH 3, -N (CH 3) 2, -N (C 2 H 5) 2, - _{NH-C 2 H 5, -N-} (CH 3, C 2 H 5), - CONH 2, -CON (CH 3) 2, -CONH- (CH 3), - N 2 C 3 H 3 (CH 3 ₎ - represents a _{CH 2 n (CO) 2 C} 6 H 4, M is one to three-valent metal, n represents 1 or 2).

  A dichloroquinacridone pigment is obtained by heating in water in the second step. Whether the product contained in the pigment mixture in the finishing treatment is a yellowish red dichloroquinacridone pigment can be confirmed visually or by X-ray diffraction measurement.

  Thus, from the pigment mixture obtained in the second step, water and, if necessary, aliphatic alcohols are also removed or recovered, and solids mainly composed of dichloroquinacridone pigment are washed, filtered, dried, pulverized, etc. By carrying out, yellowish red and transparent dichloroquinacridone pigment powder can be obtained. As the cleaning method, either water washing or hot water washing can be employed.

  Examples of the drying method after washing and filtration described above include a batch-type or continuous-type method in which the pigment is dehydrated by heating at 80 to 120 ° C. with a heating source installed in a dryer. Examples of the dryer used at that time include a box-type dryer, a band dryer, and a spray dryer.

  As a pulverization method after drying, when drying using a box-type dryer or a band dryer, it is performed in order to break up the powder that has become a lamp shape or the like into powder, for example, Examples thereof include a mortar, hammer mill, disc mill, pin mill, jet mill and the like.

  Thus, in the present invention, a yellowish red dichloroquinacridone pigment can be produced mainly by heat treatment in water. Since water alone or the minimum necessary amount of organic solvent is used, it can be said that this is an environmentally friendly manufacturing method with a light load on waste solvent treatment or recovery / reuse.

  The yellowish red dichloroquinacridone pigment obtained in this way is used for known and conventional applications such as printing inks, paints, plastic moldings, inkjet dyes, electrostatic charge developments from the viewpoint of its characteristic hue and high transparency. It can be used for coloring toners, liquid crystal color filters, and the like.

  Hereinafter, the present invention will be described in detail with reference to Examples, Comparative Examples, and Test Examples. The present invention is not limited to these examples. Unless otherwise specified, both “part” and “%” are based on mass.

In a reaction vessel equipped with a stirrer, 218 parts of 85% phosphoric acid and 382 parts of anhydrous phosphoric acid were added and stirred for 20 minutes to obtain 600 parts of polyphosphoric acid having an anhydrous phosphoric acid content of 86%. To this, 100 parts of 98% pure 2,5-di (3-chloroanilino) terephthalic acid was added and stirred at 125 ° C. for 3 hours to obtain a cyclization reaction product. In another vessel equipped with a stirrer, 3000 parts of water at 15 ° C. is put, and the cyclized reaction product is charged under strong stirring, stirred as it is for 30 minutes, filtered, washed with water, and washed with dichloroquinacridone compound (crude pigment). ) Of 350 parts (solid content 25%). A pressurizable reaction vessel equipped with a stirrer is charged with 350 parts of a wet cake of the dichloroquinacridone compound (crude pigment) and 800 parts of water, and the contents are stirred at 125 ° C. for 7 hours without stirring media. Stir. Thereafter, the mixture was cooled to room temperature, filtered, washed with hot water, dried and ground to obtain 85 parts of dichloroquinacridone pigment (CI Pigment Red 209).
This is mainly based on dichloroquinacridone pigments having specific peaks at Bragg angles 2θ (± 0.2 °) = 5.8 °, 11.8 °, 12.9 °, 24.2 ° and 26.3 ° in X-ray diffraction measurement using CuKα rays. Contained.

A pressurizable reaction vessel equipped with a stirrer was charged with 350 parts of a wet cake of the same dichloroquinacridone compound (crude pigment) obtained in Example 1, 100 parts of isobutanol, and 700 parts of water. Stir for hours. Thereafter, the mixture was cooled to room temperature, filtered, washed with hot water, dried and ground to obtain 85 parts of dichloroquinacridone pigment (CI Pigment Red 209).
This is mainly based on dichloroquinacridone pigments having specific peaks at Bragg angles 2θ (± 0.2 °) = 5.8 °, 11.8 °, 12.9 °, 24.2 ° and 26.3 ° in X-ray diffraction measurement using CuKα rays. Contained.

  In each of these examples, it was possible to appropriately control the crystal, and compared to water alone or aliphatic alcohols alone, it was possible to more easily prevent the generation of different crystals and control the particle size and shape. . Further, since only stirring with a stirring blade was performed, the dichloroquinacridone pigment was not pulverized during the finishing treatment. As a result, there is no need for separate preparation of grinding media, no deterioration in pigment quality due to contamination of grinding media, and minimal generation of pigment particles that affect application properties such as viscosity and light resistance. I was able to do it. Furthermore, since the organic solvent used in combination is a small amount with respect to water, the labor of waste solvent treatment or recovery / reuse is reduced.

(Comparative Example 1)
To a reaction vessel equipped with a stirrer, 250 parts of 85% phosphoric acid and 350 parts of anhydrous phosphoric acid were added and stirred for 20 minutes to obtain 600 parts of polyphosphoric acid having an anhydrous phosphoric acid content of 84%. To this, 100 parts of 98% pure 2,5-di (3-chloroanilino) terephthalic acid was added and stirred at 125 ° C. for 3 hours to obtain a cyclization reaction product. Subsequent operations were carried out in the same manner as in Example 1 except that the same amount of the cyclization reaction product was used to obtain 85 parts of dichloroquinacridone pigment (CI Pigment Red 209).

(Comparative Example 2)
In the same manner as in Example 1, 350 parts of a dichloroquinacridone compound (crude pigment) wet cake (solid content 25%) was obtained and dried in the same manner to obtain a powder of a dichloroquinacridone compound (crude pigment). . In a pressurizable reaction vessel equipped with a stirrer, 87 parts of the dichloroquinacridone compound (crude pigment) and 1000 parts of N-methyl-2-pyrrolidone were charged and stirred at 125 ° C. for 7 hours. Thereafter, the mixture was cooled to room temperature, filtered, washed with hot water, dried and ground to obtain 85 parts of dichloroquinacridone pigment (CI Pigment Red 209).
In this comparative example, a large amount of N-methyl-2-pyrrolidone was required, and it took time and effort to process or recover and reuse the waste solvent.

(Comparative Example 3)
In a reaction vessel equipped with a stirrer, 218 parts of 85% phosphoric acid and 382 parts of anhydrous phosphoric acid were added and stirred for 20 minutes to obtain 600 parts of polyphosphoric acid having an anhydrous phosphoric acid content of 86%. To this, 100 parts of 93% pure 2,5-di (3-chloroanilino) terephthalic acid was added and stirred at 125 ° C. for 3 hours to obtain a cyclization reaction product. Place 3000 parts of water at 15 ° C. in another vessel with a stirrer, add the cyclized reaction product under strong stirring, stir for 30 minutes, filter, wash with water, wet dichloroquinacridone crude pigment 350 parts of cake (solid content 25%) were obtained. 350 parts of a wet cake of the dichloroquinacridone crude pigment and 800 parts of water were charged into a pressurizable reaction vessel equipped with a stirrer, and stirred at 140 ° C. for 7 hours. Thereafter, the mixture was cooled to room temperature, filtered, washed with hot water, dried and ground to obtain 85 parts of dichloroquinacridone pigment (CI Pigment Red 209).

(Test example)
(1) Baking paint test with melamine alkyd resin 4.0 g of each of the dichloroquinacridone pigments obtained in Examples 1 and 2 and Comparative Examples 1 to 3; 1026 clear (manufactured by Kansai Paint Co., Ltd.) 16.0 g and baking thinner No. 3 (manufactured by Kansai Paint Co., Ltd.) and 80 g of 3 mmφ glass beads were placed in a polyethylene bottle having a capacity of 100 ml and dispersed for 1 hour with a paint conditioner (manufactured by Toyo Seiki Co., Ltd.). An additional 50.0 g of 1026 clear was added and dispersed for another 10 minutes with a paint conditioner to obtain primary color paints, respectively.

  3.0 g of each of the obtained primary color paints and Amirac No. 1531 White (manufactured by Kansai Paint Co., Ltd.) in an amount of 10.0 g was put in a polyethylene cup and uniformly mixed with a planetary stirrer KK-102 (manufactured by Kurashiki Boseki Co., Ltd.) to obtain a light-colored paint.

  The primary color paints are placed side by side on art paper with a black belt, applied and developed with a 10 mil (254 μm) film applicator, allowed to stand for about 1 hour, placed in a dryer adjusted to 140 ° C., and baked and dried for about 20 minutes. The primary color coating film was obtained. Each of the light-colored paints is placed side by side on art paper, applied and developed with a 6 mil (152 μm) film applicator, allowed to stand for about 1 hour, and then placed in a drier adjusted to 140 ° C. and baked and dried for about 20 minutes. A light-colored coating film was obtained.

(2) Evaluation criteria Transparency: Transparency of the pigments of Example 2 and Comparative Examples 1 to 3 was visually determined by 10-step evaluation with the blackness of the black belt portion of the primary color coating film as the standard. did. Here, the standard determination is 5, and the larger the value, the higher the blackness.
Hue: The pale color coating film was measured using a datacolor international SPECTRA FLASH 500 spectrophotometer (manufactured by datacolor international, USA) in a D65 light source 10-degree field of view, and a hue angle h (CIE LAB color system) was calculated. The numerical value of the hue angle h fluctuates in the range of 0 to 360, and returns to the original value at 360 = 0. That is, in the range of hue angles 350 to 360 = 0 to 10, it means that the closer to 10, the yellowish red, and the closer to 350, the bluer red (Table 1).

Table 1

As can be seen from the evaluation results of Example 1 and Comparative Example 1, the pigment of Example 1 obtained by cyclization reaction with polyphosphoric acid having an anhydrous phosphoric acid content of 85% by mass or more had an anhydrous phosphoric acid content of 85. Compared to the pigment of Comparative Example 1 obtained by cyclization with less than mass% of polyphosphoric acid, the hue is significantly yellowish and excellent in transparency.
As can be seen from the evaluation results of Example 1 and Comparative Example 2, the pigment of Example 1 obtained by heat treatment of the dichloroquinacridone compound in water was subjected to heat treatment of the dichloroquinacridone compound in N-methyl-2-pyrrolidone. Compared to the pigment of Comparative Example 2 obtained, the hue is significantly yellowish and excellent in transparency.
As can be seen from the evaluation results of Example 1 and Comparative Example 3, the pigment of Example 1 obtained using 2,5-di (3-chloroanilino) terephthalic acid having a purity of 96% or more has a purity of 96%. The hue is significantly yellowish compared to the pigment of Comparative Example 1 obtained using the following 2,5-di (3-chloroanilino) terephthalic acid.

As is apparent from the measurement results in Table 1, the dichloroquinacridone pigments of the present invention obtained in Examples 1 and 2 are significantly more yellowish red and highly colored than the pigments of Comparative Examples 1 to 3. It turns out that it has transparency.

Claims (2)

Cyclization reaction obtained by cyclizing 1 part of 2,5-di- (3-chloroanilino) terephthalic acid having a purity of 96% or more in 3 to 10 parts of polyphosphoric acid having a phosphoric anhydride content of 85% by mass or more Dichloroquinacridone , wherein the liquid is hydrolyzed by mixing with water in an amount of 2 to 20 parts equivalent to 1 part of the cyclization reaction liquid in terms of mass , and then filtered to heat the solid content in water. A method for producing a pigment. The manufacturing method according to claim 1, wherein the water in heating the solid content is water containing 20% by mass or less of aliphatic alcohols.