JP2018145353A - Black indigoid pigment and colorant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an infrared reflecting black indigoid pigment with a novel skeleton exhibiting high blackness (coloring power) and excellent endurance such as heat resistance.SOLUTION: The black indigoid pigment is represented by the general formula (1) in the figure, where X each independently represent a chlorine atom, bromine atom, fluorine atom, alkyl group, alkoxy group or nitro group, with 8≥n+m≥0.SELECTED DRAWING: None

Description

  The present invention relates to a near-infrared non-absorbing black indigoid pigment and a colorant using the same.

  Conventionally, as black pigments used in paints, printing inks, plastic colorants, and the like, carbon black pigments and iron oxide pigments are generally used. These black pigments exhibit black color by absorbing all light rays including visible light region of sunlight.

  Black pigments (particularly carbon black pigments) absorb visible light (about 380 to 780 nm) to show black color, but actually have a wavelength of 800 to 1,400 nm, which has a large contribution to heat. Light in the near infrared region including the region is also absorbed. For this reason, the article | item colored with the above black pigments had the subject that it heated up easily by being exposed to sunlight. In addition, as products colored with black pigments, precision products such as a black matrix for color filters have recently appeared.

  The black pigment used for constituting the black matrix for the color filter is required to be electrically insulating in order to prevent malfunction of the thin film transistor. Carbon black is a pigment with low electrical resistance. For this reason, carbon black cannot be said to be suitable as a coloring material used for products such as a black matrix, and it is desirable to use a light-shielding material with better electrical insulation. As related prior art, various types of black organic pigments that are difficult to increase in temperature even when exposed to sunlight and have electrical insulation have been studied (Patent Document 1). Further, an azo black pigment useful for forming a black matrix for a color filter has been proposed (Patent Document 2).

Special table 2007-522297 Japanese Patent Laid-Open No. 2015-110691

  If the azo black pigment proposed in Patent Document 2 is used, it is possible to form a black matrix having excellent characteristics such as electrical insulation. However, there is still room for improvement in the high level of blackness (coloring power) and durability such as heat resistance, which are required in accordance with recent technological advances.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is a novel skeleton having high blackness (coloring power) and excellent durability such as heat resistance. It is an object of the present invention to provide an infrared reflective black indigoid pigment. Another object of the present invention is to provide a pigment colorant using the above black indigoid pigment.

That is, according to the present invention, the following black indigoid pigment is provided.
[1] A black indigoid pigment represented by the following general formula (1).

（前記一般式（１）中、Ｘは、それぞれ独立に塩素原子、臭素原子、フッ素原子、アルキル基、アルコキシ基、又はニトロ基を示し、８≧ｎ＋ｍ≧０である）

(In the general formula (1), each X independently represents a chlorine atom, a bromine atom, a fluorine atom, an alkyl group, an alkoxy group, or a nitro group, and 8 ≧ n + m ≧ 0)

  [2] The black indigoid pigment according to [1] represented by the following formula (1-1), (1-2), or (1-3).

  [3] The black indigoid pigment according to [1] or [2], which has a blackness of 240 or more in an alkyd / melamine baking paint.

Furthermore, according to the present invention, the following pigment colorants are provided.
[4] A colorant containing the black indigoid pigment according to any one of [1] to [3].
[5] The colorant according to [4], which is used to form a black matrix or a light shielding film for a color filter.

  According to the present invention, it is possible to provide an infrared-reflective black indigoid pigment having a novel skeleton, which has high blackness (coloring power) and excellent durability such as heat resistance. Moreover, according to this invention, the coloring agent using this black indigoid pigment can be provided.

It is a visible-infrared absorption spectrum of the coating film formed with the pigment (1-1) of Example 1. It is a visible-infrared absorption spectrum of the coating film formed with the pigment (1-2) of Example 2. It is a visible-infrared absorption spectrum of the coating film formed with the pigment (1-3) of Example 3. It is a visible-infrared absorption spectrum of the coating film formed with the pigment (3) of the comparative example 2. It is a visible-infrared absorption spectrum of the coating film formed with the pigment (4) of the comparative example 3.

<Black indigoid pigment>
Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments. The black indigoid pigment of the present invention is a pigment having a structure represented by the following general formula (1). The details will be described below.

（前記一般式（１）中、Ｘは、それぞれ独立に塩素原子、臭素原子、フッ素原子、アルキル基、アルコキシ基、又はニトロ基を示し、８≧ｎ＋ｍ≧０である）

(In the general formula (1), each X independently represents a chlorine atom, a bromine atom, a fluorine atom, an alkyl group, an alkoxy group, or a nitro group, and 8 ≧ n + m ≧ 0)

  In general formula (1), the alkyl group represented by X is preferably an optionally branched lower alkyl group having 1 to 6 carbon atoms, and is a lower alkyl group having 1 to 3 carbon atoms. More preferably. Moreover, the alkoxy group represented by X is preferably a C1-C6 lower alkoxy group which may have a branch, and more preferably a C1-C3 lower alkoxy group.

  One of the important characteristics of the black indigoid pigment of the present invention is that it has a structure represented by the general formula (1). The pigment having the structure represented by the general formula (1) has a pigment characteristic equal to or higher than that of other indigoid pigments. Moreover, since the black indigoid pigment of the present invention has a 1,5-diaminoanthraquinone skeleton in its structure, it exhibits a special color tone.

  The color tone of the pigment represented by the general formula (1) is different from other indigoid pigments. Common indigoid pigments are light-colored pigments having a yellow to orange color. On the other hand, since the pigment represented by the general formula (1) effectively absorbs light in the wavelength region of 400 to 850 nm, it exhibits excellent blackness.

  As a result of intensive studies by the present inventors, it has been found that the compound having a 2,6-diaminoanthraquinone skeleton represented by the following formula (2) does not exhibit black color. The pigment represented by the general formula (1) is presumed to have a planar structure by forming an intramolecular hydrogen bond between the carbonyl oxygen of anthraquinone and the hydrogen of the amino group. For this reason, a strong intermolecular π-π interaction is formed, and it is considered that light is absorbed to a long wavelength region.

(Method for producing black indigoid pigment)
The black indigoid pigment of the present invention is, for example, an inert compound comprising a compound represented by the following general formula (A) and a compound represented by the following general formula (B) and a compound represented by the following formula (C). It can manufacture by making it react in a solvent.

（前記一般式（Ａ）及び（Ｂ）中、Ｘは、それぞれ独立に塩素原子、臭素原子、フッ素原子、アルキル基、アルコキシ基、又はニトロ基を示し、８≧ｎ＋ｍ≧０である）

(In the general formulas (A) and (B), X independently represents a chlorine atom, a bromine atom, a fluorine atom, an alkyl group, an alkoxy group, or a nitro group, and 8 ≧ n + m ≧ 0)

  Specific examples of the compounds represented by the general formulas (A) and (B) (isatins) include compounds represented by the following formulas.

  Since the above compound having an indigoid structure is easily hydrolyzed, it is preferable to use a hydrophobic solvent as an inert solvent. Specific examples of the hydrophobic solvent include aliphatic hydrocarbons such as n-hexane, n-heptane, cyclohexane, methylcyclohexane, ethylcyclohexane, 2-methylpentane; toluene, xylene, chlorobenzene, dichlorobenzene, nitrobenzene, chloronaphthalene, etc. And aromatic hydrocarbons. In addition, it is preferable to use a solvent having a high solubility and a high boiling point such as chlorobenzene, dichlorobenzene, nitrobenzene, or chloronaphthalene because the reaction proceeds smoothly.

  The reaction temperature is preferably 100 to 140 ° C. When the reaction is carried out at a temperature of less than 100 ° C., a large amount of 1-substitution product is likely to be produced, and the yield of the target compound may be lowered. In addition, it is preferable to coexist an acid as a catalyst because the reaction proceeds more smoothly.

  It is preferable to perform pigmentation treatment by heating and stirring at 150 to 200 ° C. in an inert solvent because the blackness of the resulting pigment increases. Specific examples of the inert solvent include aromatic hydrocarbons such as xylene, dichlorobenzene, nitrobenzene, and chloronaphthalene.

<Colorant>
The colorant of the present invention contains the above black indigoid pigment. For example, the coloring agent which is a coloring composition can be obtained by making the above-mentioned black indigoid pigment contain (disperse) in a liquid dispersion medium or a solid dispersion medium. That is, depending on the coloring object, application, and method of use, a pigment component containing a black indigoid pigment may be dispersed in a liquid dispersion medium to form a liquid composition, or dispersed in a solid dispersion medium to form a solid composition. Also good.

  As the pigment component to be dispersed in a dispersion medium such as a liquid dispersion medium or a solid dispersion medium, other pigments other than the black indigoid pigment can be used. That is, in the dispersion medium, only the black indigoid pigment may be dispersed as a pigment component, or a pigment component containing a black indigoid pigment and other pigments may be dispersed. As other pigments, chromatic color pigments, white pigments, other black pigments, extender pigments, and the like can be used. It can be used singly or in combination of two or more according to the target color. A colorant capable of dark chromatic coloring, achromatic coloring, and black coloring can be obtained by dispersing other pigments in the dispersion medium together with the black indigoid pigment.

  What is necessary is just to set suitably content of the black indigoid pigment in a coloring agent according to a use, and it does not specifically limit. Specifically, the content of the black indigoid pigment in the colorant may be about 1 to 50% by mass based on the total mass of the colorant.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified.

<Manufacture of pigments>
Example 1 Production of Black Indigoid Pigment (1-1) To 130 parts of nitrobenzene, 4.8 parts of 1,5-diaminoanthraquinone, 5.9 parts of isatin, and 3.8 parts of paratoluenesulfonic acid monohydrate And heated at 130 ° C. for 3 hours. The mixture was filtered while hot, washed with methanol and water, and then dried at 80 ° C. to obtain 9.2 parts of pigment (1-1) represented by the following formula (1-1). When mass spectrometry was performed by MALDI, 496 peaks were detected.

Example 2 Production of Black Indigoid Pigment (1-2) In the same manner as in Example 1 except that 9.0 parts of 5-bromoisatin was used instead of isatin, the following formula (1-2) ) 12.2 parts of pigment (1-2) represented by When mass spectrometry was performed by MALDI, 654 peaks were detected.

(Example 3) Production of black indigoid pigment (1-3) In the same manner as in Example 1 except that 3.0 parts of isatin and 4.5 parts of 5-bromoisatin were used instead of isatin, Pigment (1-3) represented by the following formula (1-3), pigment (1-1) represented by formula (1-1), and pigment represented by formula (1-2) (1- 10.0 parts of the mixture of 2) was obtained. When mass spectrometry was performed by MALDI, peaks of 496, 575, and 654 were detected.

(Comparative Example 1) Production of orange indigoid pigment (2) In the same manner as in Example 1 except that 2,6-diaminoanthraquinone was used instead of 1,5-diaminoanthraquinone, the following formula (2 9.2 parts of a pigment (2) represented by When mass spectrometry was performed by MALDI, 496 peaks were detected. The obtained pigment (2) was orange.

(Comparative Examples 2 and 3)
The commercially available pigments shown below were designated as pigment (3) of comparative example 2 and pigment (4) of comparative example 3, respectively.
Comparative Example 2 (Pigment (3)): Trade name “Chromofine Black A1103” (manufactured by Dainichi Seika Kogyo Co., Ltd.)
Comparative Example 3 (Pigment (4)): Trade name “Carbon Black # 45B” (Mitsubishi Chemical Corporation)

<Evaluation>
(Paint test)
Each component was blended according to the blending shown below, and dispersed for 90 minutes using a paint conditioner to prepare a paint (dark paint). The paint prepared using an applicator (3 mils) was developed on color paper and then baked at 140 ° C. for 30 minutes to form a coating film.
-Pigment: 1.5 parts-Trade name "Super Becamine J-820" (* 1): 8.5 parts-Trade name "Phthalkid 133-60" (* 2): 17.0 parts-Xylene / 1- Butanol (2/1 (mass ratio)) mixed solvent: 5.0 parts (* 1) Butylated melamine resin (Dainippon Ink & Chemicals, Inc.)
(* 2) Short oil alkyd resin of coconut oil (manufactured by Hitachi Chemical Co., Ltd.)

(Blackness, hue angle, brightness, and saturation)
Using a spectrophotometer (trade name “U-4100”, manufactured by Hitachi High-Technologies Corporation), the visible-infrared absorption spectrum of the coating film formed in the aforementioned “paint test” was measured. The measured visible-infrared absorption spectra are shown in FIGS. In addition, CIE trichromatic stimulation values (X, Y, Z) were measured according to a conventional method, and the blackness, L ^* , a ^* , and b ^* of the coating film were measured and calculated. The results are shown in Table 1.

  As shown in FIG. 4, the reflectance of the coating film formed with the pigment (3) of Comparative Example 2 is rapidly increased from the vicinity of 680 nm to the long wavelength side. However, the blackness is insufficient because it rises quickly to absorb light in the wavelength region of 400 to 700 nm, which is the visible light region. Moreover, as shown in FIG. 5, it turns out that the coating film formed with the pigment (4) of the comparative example 3 has absorbed the light of the wide wavelength range to-2500 nm, and does not show infrared reflectivity at all. On the other hand, as shown in FIGS. 1-3, the coating film formed with the pigments (1-1), (1-2), and (1-3) of Examples 1-3 is visible light region. As well as absorbing light in a well-balanced manner, it absorbs light in the wavelength region near 500 to 800 nm without omission, indicating that high blackness is exhibited. Furthermore, it turns out that the coating film formed with the pigments (1-1), (1-2), and (1-3) of Examples 1 to 3 shows good infrared reflectivity.

(Infrared reflective)
The infrared reflectance of the coating film formed in the aforementioned “paint test” was measured, and the infrared reflectance was evaluated according to the following evaluation criteria. The results are shown in Table 1.
○: Infrared reflectance at 1300 nm is 30% or more ×: Infrared reflectance at 1300 nm is less than 30%

(Heat-resistant)
Each pigment was subjected to thermogravimetry and differential thermal analysis (TG-DTA). And the weight loss rate in 350 degreeC was computed, and heat resistance was evaluated according to the evaluation criteria shown below. The results are shown in Table 1.
○: Weight loss rate at 350 ° C is 10% or less ×: Weight loss rate at 350 ° C is greater than 10%

  The black indigoid pigment of the present invention is useful for applications requiring high blackness such as a black matrix. Further, since the reflectance of light in the near infrared region is high, a pigment such as carbon black is useful as an inappropriate heat ray reflective black pigment.

Claims (5)

A black indigoid pigment represented by the following general formula (1).

(In the general formula (1), each X independently represents a chlorine atom, a bromine atom, a fluorine atom, an alkyl group, an alkoxy group, or a nitro group, and 8 ≧ n + m ≧ 0) The black indigoid pigment according to claim 1, which is represented by the following formula (1-1), (1-2), or (1-3).

  The black indigoid pigment according to claim 1 or 2, having a blackness of 240 or more in an alkyd / melamine baking paint.   The coloring agent containing the black indigoid pigment as described in any one of Claims 1-3.   The colorant according to claim 4, which is used for forming a black matrix or a light shielding film for a color filter.

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