JP6745777B2 - Pigment dispersant, pigment composition, and pigment colorant - Google Patents

Description

The present invention relates to a pigment dispersant, a pigment composition, and a pigment colorant. More specifically, printing inks (offset inks, gravure inks, etc.), various paints, plastics, pigment printing agents, dry toners for electrophotography, wet toners for electrophotography, inks for inkjet recording, inks for thermal transfer recording, resists for color filters. The present invention relates to a pigment dispersant to be blended with a writing instrument ink or the like.

Generally, it is difficult to mix and disperse a pigment (particles) in a vehicle such as a paint, a gravure ink and an offset ink in a stable state. For example, fine pigment particles once dispersed in the vehicle tend to aggregate in the vehicle. When the pigment particles aggregate, the viscosity of the vehicle increases. In addition, when a vehicle containing pigment particles in an agglomerated state is used, various problems such as a decrease in coloring power of ink or paint and a decrease in gloss of a coating film are likely to occur. Among the pigments, it is particularly difficult to mix and disperse the black pigment in a stable state.

Carbon black-based pigments, iron oxide-based pigments and the like are generally used as black pigments used as colorants for paints, printing inks, plastics and the like. These black pigments exhibit a black color by absorbing all light rays in the visible light region of sunlight.

Sunlight is an electromagnetic wave, and light in the wavelength range of approximately 380 nm to 780 nm is visible light. Therefore, even if all visible light is absorbed, a black color is obtained. Light in the wavelength region on the longer wavelength side than visible light and in the wavelength region of 0.8 μm to 2.5 μm (800 nm to 2,500 nm) between the visible light and the infrared region is called near infrared light. The carbon black pigment also absorbs this near infrared ray. In the wavelength region of sunlight, it is said that light having a large degree of contribution to heat is light in the wavelength region of 800 nm to 1400 nm among near infrared rays.

As described above, black pigments such as carbon black-based pigments also absorb near infrared rays in the wavelength region of 800 nm to 1,400 nm, which greatly contributes to heat. For this reason, there is a problem that an article colored with a black pigment is likely to be heated by sunlight. As an article colored with a black pigment, there are many delicate products such as a black matrix (hereinafter, also simply referred to as “BM”) constituting a color filter (hereinafter, simply referred to as “CF”). Therefore, various studies have been conducted on black pigments that do not heat up even when exposed to sunlight, colorant compositions that color various articles black, and the like.

Patent Document 1 discloses a black azo pigment having an azomethine group, which absorbs visible light to exhibit a black color and reflects infrared rays. In addition, since it reflects infrared rays, it has been proposed to obtain an article that is not excessively heated even by direct sunlight by coloring it with this black azo pigment.

By the way, with the remarkable development of information-oriented devices in recent years, a liquid crystal color display (hereinafter, also simply referred to as “LCD”) has been applied as an information display member to many information display-related devices. Along with this, there is a demand for improvement in the display quality of LCDs and cost reduction. Therefore, the CF mounted on the LCD is also required to have higher quality in terms of color characteristics and optical characteristics such as fineness, color density, light transmittance, and contrast.

In CF, R (red), G (green), and B (blue) pixels are arranged in a stripe shape, a mosaic shape, or a triangle shape, and the periphery of each pixel is shielded to block unnecessary light. A grid-shaped BM is formed on the. Then, light is emitted from the back surface by a backlight, and the transmitted light of each of the R, G, and B pixels is colored by color mixing to form an image. Red pigments, green pigments, blue pigments, yellow pigments, purple pigments, and the like are used for chromatic (RGB) pixels, and they have been improved. Further, as a light-shielding material forming the BM, a conventional metal chromium film is being replaced with a resin film using a black pigment in order to cope with an increase in substrate size and a reduction in environmental load.

In addition, various improvements have been proposed in the CF pixel display system, and the light-shielding black pigment used in the BM is also improved accordingly. For example, in order to widen the viewing angle, an in-plane switching system (IPS system) has been proposed in which an electric field is applied parallel to the substrate to convert the liquid crystal layer and display pixels. Further, a black matrix on array method (BOA method) in which a BM is formed on a thin film transistor (TFT) and a color filter on array method (COA method) have been proposed. In these methods, the aperture ratio is increased, so that the pixel area can be expanded. Furthermore, since the efficiency of the bonding process is improved, the work process can be rationalized.

For example, in order to further widen the viewing angle by the IPS method, it is necessary to maintain the interval (cell gap) between the substrates that sandwich the liquid crystal layer with high accuracy and constant. However, it is difficult to uniformly adjust the cell gap by the conventional method of spraying the beaded spacers. Therefore, as a method of uniformly adjusting the cell gap, a method of thickening the BM itself or a method of laminating a resin that supports the spacing of the coloring layer, the photoresist layer, or the like on the BM to make it thicker is proposed. ing. Further, in these methods, since the conventional bead-shaped spacers are not used, it is said that it is possible to suppress deterioration of display quality due to light scattering and transmission (Patent Documents 2 and 3).

Since the IPS method, the BOA method, the COA method, and the like are methods of forming a BM on an active element such as a TFT, the active element may malfunction if the BM is not electrically insulating. Carbon black pigments that have been conventionally used as light-shielding black pigments have low electric resistance, and therefore cannot be said to be suitable as black pigments applied to the above-mentioned method. Therefore, there is a demand for a light-shielding black pigment that is more excellent in electrical insulation.

To meet such a demand, for example, a black pigment for BM has been proposed in which carbon black having a regulated oxygen content is coated with a highly insulating resin film to improve electrical insulation (Patent Document 4). Further, it has been proposed to apply a BM formed by using an insulating carbon black whose volume resistance value is measured and selected, or a carbon black which is coated with a resin to improve electric insulation to a COA method. (Patent Document 5). However, since the carbon black pigment is essentially a material having conductivity, it is difficult to ensure sufficient insulation even when it is coated with a resin.

On the other hand, in order to ensure the insulating property of BM, it has been proposed to use the black azo pigment having an azomethine group proposed in Patent Document 1 (Patent Document 6). However, it has been difficult to mix and disperse the black azo pigment proposed in Patent Document 1 in a vehicle in a stable state. The fine pigment particles once dispersed in the vehicle tend to aggregate in the vehicle. Then, the viscosity of the vehicle in which the pigment particles are aggregated increases. Further, when a vehicle containing agglomerated pigment particles is used, the coloring power of the ink or paint is reduced, the gloss of the coating film is reduced, or the optical density is insufficient as a light-shielding material forming BM, etc. The problem of.

In order to stably disperse pigment particles such as a black azo pigment having an azomethine group in a dispersion medium, a method using a pigment derivative as a dispersant, a method using a pigment treated with a pigment derivative, etc. have been proposed. .. Specifically, when using a phthalocyanine-based pigment such as PB15:6, it has been proposed to use a substituted derivative of phthalocyanine as a pigment dispersant (Patent Document 7). Further, when an anthraquinone pigment such as PR177 is used, it has been proposed to use a substituted derivative of anthraquinone as a pigment dispersant (Patent Document 8). Furthermore, when using a diketopyrrolopyrrole pigment such as PR254, it has been proposed to use a substituted derivative of diketopyrrolopyrrole as a pigment dispersant (Patent Document 8).

Japanese Patent Publication No. 4-15265 JP, 2000-66018, A JP-A-2002-341332 Japanese Patent No. 3543501 Patent No. 4338479 Japanese Patent No. 2819512 JP, 2002-55224, A JP 2001-240780 A

However, even if the pigment derivatives proposed in Patent Documents 7 and 8 are used, it is difficult to stably disperse the black azo pigment having an azomethine group proposed in Patent Document 1 in a medium. Further, since the color tone of the pigment derivative proposed in Patent Documents 7 and 8 is not black, there is a problem that the optical density of black is lowered.

The present invention has been made in view of such problems of the prior art, and the problem is that a liquid material such as an ink or paint containing pigment particles such as a black azo pigment in a dispersed state. To provide a pigment dispersant capable of significantly improving fluidity, suppressing aggregation of pigment particles, and preventing generation of foreign matter, and capable of producing a colored article excellent in optical density. is there. Another object of the present invention is to provide a pigment composition and a pigment colorant obtained by using the above pigment dispersant.

That is, according to the present invention, the following pigment dispersant is provided.
[1] A pigment dispersant which is a compound represented by the following general formula (1).

（前記一般式（１）中、Ｘは１以上のスルホン酸基を有する芳香族基を示し、Ｒ₁及びＲ₂は、相互に独立に、水素原子、ハロゲン原子、アルキル基、アルコキシ基、又は水酸基を示す）

(In the general formula (1), X represents an aromatic group having one or more sulfonic acid groups, and R ₁ and R ₂ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or Indicates a hydroxyl group)

[2] The pigment dispersant according to the above [1], wherein in the general formula (1), X is a group represented by any one of the following general formulas (2) to (4).

（前記一般式（２）〜（４）中、＊は窒素原子との結合位置を示し、Ｙは、相互に独立に、ハロゲン原子を示し、ｎは０〜２の数を示す）

(In the general formulas (2) to (4), * represents a bonding position with a nitrogen atom, Y independently represents a halogen atom, and n represents a number of 0 to 2.)

Moreover, according to this invention, the pigment composition shown below is provided.
[3] A pigment composition containing a pigment and the pigment dispersant according to the above [1] or [2].
[4] The pigment composition according to the above [3], wherein the content of the pigment dispersant is 0.5 to 40 parts by mass with respect to 100 parts by mass of the pigment.

Further, according to the present invention, the following pigment colorants are provided.
[5] A pigment colorant containing the pigment composition according to the above [3] or [4] and a film forming material.
[6] The pigment colorant according to the above [5], which is for image display, image recording, gravure printing ink, writing ink, plastic, pigment printing, paint, or black matrix of color filter. ..

According to the present invention, it is possible to remarkably improve the fluidity of a liquid material such as an ink or a coating containing pigment particles such as a black azo pigment in a dispersed state, and it is possible to suppress aggregation of the pigment particles, and It is possible to provide a pigment dispersant capable of producing a colored article excellent in optical density while preventing generation of foreign matter. Further, according to the present invention, it is possible to provide a pigment composition and a pigment colorant obtained by using the above pigment dispersant.

<Pigment dispersant>
Hereinafter, the present invention will be described in detail by taking a preferred embodiment as an example. One of the main features of the pigment dispersant of the present invention is that it is a compound represented by the following general formula (1). The pigment dispersant of the present invention having such characteristics has excellent affinity for various pigments, and is suitable as a pigment dispersant for dispersing various pigments regardless of organic or inorganic. Can be used for Further, since the pigment dispersant of the present invention has an excellent pigment dispersing effect, it can be used as a material for preparing pigment colorants for various uses.

（前記一般式（１）中、Ｘは１以上のスルホン酸基を有する芳香族基を示し、Ｒ₁及びＲ₂は、相互に独立に、水素原子、ハロゲン原子、アルキル基、アルコキシ基、又は水酸基を示す）

(In the general formula (1), X represents an aromatic group having one or more sulfonic acid groups, and R ₁ and R ₂ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or Indicates a hydroxyl group)

In general formula (1), the aromatic group represented by X may have a substituent other than a sulfonic acid group. Examples of the substituent other than the sulfonic acid group include a halogen atom, an alkyl group, an alkoxy group, a hydroxyl group and the like. Examples of the halogen atom include a fluorine atom (F), a chlorine atom (Cl), a bromine atom (Br) and the like.

In general formula (1), X is preferably a group represented by any of the following general formulas (2) to (4).

（前記一般式（２）〜（４）中、＊は窒素原子との結合位置を示し、Ｙは、相互に独立に、ハロゲン原子を示し、ｎは０〜２の数を示す）

(In the general formulas (2) to (4), * represents a bonding position with a nitrogen atom, Y independently represents a halogen atom, and n represents a number of 0 to 2.)

In the general formulas (2) to (4), specific examples of the halogen atom represented by Y include a fluorine atom (F), a chlorine atom (Cl), a bromine atom (Br) and the like.

The pigment dispersant of the present invention exhibits an excellent action as a pigment dispersant even in a small amount. Further, the pigment composition and the pigment colorant prepared by using the pigment dispersant of the present invention are unlikely to cause thickening or gelation during storage, and a foreign material is generated in a coating film formed using these. Hateful. Specific examples of the pigment dispersant of the present invention include compounds represented by the following formulas (A) to (F).

Further specific examples of the pigment dispersant of the present invention include compounds represented by the following formulas (1-1) to (1-8).

The compound (pigment dispersant) represented by the general formula (1) can be synthesized, for example, as follows. First, an aromatic amine having one or more sulfonic acid groups is diazotized by a conventional method. Then, by reacting with a specific coupler such as N-(4-methoxyphenyl)-2-hydroxy-11H-benzo[a]carbazole-3-carboxamide, a compound represented by the general formula (1) ( A pigment dispersant) can be obtained. Although the pigment dispersant of the present invention may contain a small amount of unreacted raw materials and by-products, as long as the effects of the present invention can be obtained, these unreacted raw materials and by-products may be slightly contained. May be included.

Specific examples of the aromatic amine having one or more sulfonic acid groups used in the above synthesis method include o-aminobenzenesulfonic acid, m-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid and 2-chloroaniline-3. -Sulfonic acid, 2-chloroaniline-5-sulfonic acid, 4-chloroaniline-2-sulfonic acid, 4-chloroaniline-3-sulfonic acid, 2,5-dichloroaniline-4-sulfonic acid, 4,5- Dichloroaniline-2-sulfonic acid, 2-nitroaniline-4-sulfonic acid, o-anisidine-5-sulfonic acid, p-anisidine-5-sulfonic acid, o-toluidine-4-sulfonic acid, m-toluidine-4 -Sulfonic acid, p-toluidine-2-sulfonic acid, 2-chloro-p-toluidine-3-sulfonic acid, 2-chloro-p-toluidine-5-sulfonic acid, 4-chloro-m-toluidine-2-sulfone Acid, 3-amino-6-chlorotoluene-4-sulfonic acid, 3-amino-6-chloro-4-sulfobenzoic acid, 1-amino-8-naphthalenesulfonic acid, 2-amino-1-naphthalenesulfonic acid, 4-amino-1-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, 6-amino-1-naphthalenesulfonic acid, 5-amino-3-naphthalenesulfonic acid, 3-amino-1,5-naphthalenedisulfone Acid, 3-amino-2,7-naphthalenedisulfonic acid, 4-amino-1,5-naphthalenedisulfonic acid, 6-amino-1,3-naphthalenedisulfonic acid, 7-amino-1,3-naphthalenedisulfonic acid, 4-amino-5-hydroxy-2,7-naphthalenedisulfonic acid, 1-amino-2-hydroxy-4-naphthalenesulfonic acid, 6-amino-4-hydroxy-2-naphthalenesulfonic acid, 7-amino-4- Hydroxy-2-naphthalenesulfonic acid, 1-amino-2-anthraquinonesulfonic acid, 1-amino-5-anthraquinonesulfonic acid, 1-amino-8-anthraquinonesulfonic acid, 1-amino-4-bromoanthraquinone-2-sulfone An acid etc. can be mentioned.

Specific couplers used in the above synthetic method include N-phenyl-2-hydroxy-11H-benzo[a]carbazole-3-carboxamide, N-(4-methoxyphenyl)-2-hydroxy-11H-benzo[a ] Carbazole-3-carboxamide, N-(2-methyl-4-methoxyphenyl)-2-hydroxy-11H-benzo[a]carbazole-3-carboxamide and the like can be mentioned.

The method of using the pigment dispersant of the present invention is not particularly limited, but the following methods of use are exemplified. With either method, the desired pigment dispersion effect can be obtained.
(1) A pigment and a pigment dispersant are mixed in advance by a known method, and the obtained pigment composition is added to a vehicle or the like to disperse the pigment in the vehicle.
(2) A pigment and a pigment dispersant are separately added to a vehicle at a predetermined ratio to disperse the pigment in the vehicle.
(3) The pigment and the pigment dispersant are separately dispersed in a vehicle or the like, and then the obtained dispersions are mixed at a predetermined ratio to disperse the pigment in the vehicle.
(4) A pigment dispersant is added to the dispersion obtained by dispersing the pigment in a vehicle or the like at a predetermined ratio to disperse the pigment in the vehicle.

<Pigment composition>
The pigment composition of the present invention contains a pigment and the above-mentioned pigment dispersant. The blending amount of the pigment dispersant with respect to 100 parts by mass of the pigment is preferably 0.5 to 40 parts by mass, and more preferably 1 to 20 parts by mass. If the blending amount of the pigment dispersant is less than the above range, the desired effect of the dispersant may not be sufficiently obtained. On the other hand, if the blending amount of the pigment dispersant is larger than the above range, the effect of the dispersant reaches the ceiling and the further effect cannot be expected, and the cost of the material becomes high, which is disadvantageous in terms of productivity. May be. Furthermore, in paints and inks using a pigment composition containing such a pigment dispersant in excess, the various physical properties of the vehicle are reduced, and the hue of the pigment greatly changes depending on the color of the pigment dispersant itself. There are also cases.

By using the pigment dispersant of the present invention, specific examples of pigments that can obtain an effective dispersing effect include anthraquinone pigments, quinacridone pigments, diketopyrrolopyrrole pigments, indigo/thioindigo pigments, perinone pigments, Perylene pigments, phthalocyanine pigments, indoline pigments, isoindoline pigments, isoindolinone pigments, dioxazine pigments, quinophthalone pigments, nickel azo pigments, metal complex pigments, insoluble azo pigments, soluble azo pigments, high molecular weight azo Examples thereof include azo pigments, azomethine azo black pigments, and aniline black pigments. Among them, particularly when used for a pigment having a black hue, a more remarkable effect can be obtained, which is preferable. Such a pigment having a black hue is an azomethine azo-based black pigment (black azo pigment), 1-[4-[(4,5,6,7-tetrachloro-3-oxoisoindoline-1- Ylidene)amino]phenylazo]-2-hydroxy-N-(4-methoxy-2-methylphenyl)-11H-benzo[a]carbazole-3-carboxamide is preferred.

The method for producing the pigment composition of the present invention is not particularly limited. For example, the pigment composition of the present invention can be obtained by mixing the pigment and the pigment dispersant by a conventionally known method. Specific examples of the method for producing the pigment composition of the present invention include the following methods (1) to (4).
(1) A method of mixing powder of a pigment and powder of a pigment dispersant without using a disperser.
(2) A method in which the pigment and the pigment dispersant are mechanically mixed by a dispersing machine such as a kneader, roll, attritor, or horizontal bead mill.
(3) A method in which a liquid in which a pigment dispersant is dissolved or finely dispersed is added to and mixed with an aqueous suspension of a pigment or an organic solvent, and the pigment dispersant is uniformly deposited on the surface of the pigment.
(4) A method in which a pigment and a pigment dispersant are dissolved in a solvent having a strong dissolving power such as sulfuric acid and then co-precipitated with a poor solvent such as water.

The property of the pigment dispersant used for preparing the pigment composition may be any of solution, slurry, paste, and powder. The desired effect can be obtained regardless of the nature of the pigment dispersant used.

Here, a black azo pigment having an optical characteristic of transmitting light in the infrared region, particularly light in the near-infrared region satisfactorily, and having almost the property of blocking light in the visible light region, and the above-mentioned pigment dispersant The pigment composition to be used will be described. This pigment composition can be suitably used, for example, in an infrared filter mounted on an electronic device utilizing infrared rays. In addition, since the pigment composition transmits near infrared rays without absorbing the near infrared rays, the pigment composition can be applied to, for example, PTP (press-through pack) packaging ink, in which the margin of the printed marking on the aluminum packaging material does not hinder the detection of foreign matter. It can be preferably used. Further, the above-mentioned black azo pigment has an excellent electric insulating property, unlike a conductive material such as carbon black. Therefore, the pigment composition containing this black azo pigment and the above-mentioned pigment dispersant is also suitable as a material for forming the black matrix (BM) of the color filter (CF), for example.

<Pigment colorant>
The pigment colorant of the present invention contains the above-mentioned pigment composition and a film-forming material. The pigment colorant of the present invention can be used in a wide range of fields as a colorant for image display, image recording, gravure printing ink, writing ink, plastics, pigment printing, and paints. .. In particular, the pigment colorant of the present invention is suitable as a colorant for a black matrix of a color filter. Furthermore, the pigment colorant of the present invention is particularly useful as a material for an image recording agent such as a gravure printing ink. By using the pigment colorant of the present invention, a material for an image recording agent capable of providing a high quality image can be prepared.

The amount of the pigment composition in the pigment colorant of the present invention is preferably 5 to 500 parts by mass, and more preferably 50 to 250 parts by mass with respect to 100 parts by mass of the film-forming material. The pigment colorant of the present invention can be prepared, for example, by mixing a finely divided pigment with a film-forming material such as a resin ((co)polymer), an oligomer, or a monomer.

The pigment colorant of the present invention can also be prepared by mixing the pigment composition and a liquid containing the above film-forming material. As the liquid containing the film forming material, a liquid containing a photosensitive film forming material or a liquid containing a non-photosensitive film forming material can be used. Specific examples of the liquid containing a photosensitive film-forming material include liquids containing a photosensitive film-forming material used for ultraviolet curable ink, electron beam curable ink and the like. Specific examples of the liquid containing a non-photosensitive film forming material include varnishes used for printing inks such as letterpress inks, planographic inks, gravure inks and screen inks; varnishes used for room temperature drying or baking paints; Examples include varnishes used for coating and coating; varnishes used for thermal transfer ribbons.

Specific examples of the photosensitive film forming material include photosensitive cyclized rubber-based resin, photosensitive phenol-based resin, photosensitive polyacrylate-based resin, photosensitive polyamide-based resin, photosensitive polyimide-based resin, unsaturated polyester-based resin. Examples thereof include photosensitive resins such as polyester acrylate resin, polyepoxy acrylate resin, polyurethane acrylate resin, polyether acrylate resin, and polyol acrylate resin. Various monomers may be added as a reactive diluent to the liquid containing these photosensitive resins.

To a pigment colorant containing a photosensitive resin as a film-forming material, a photopolymerization initiator such as benzoin ether or benzophenone is added and kneaded by a conventionally known method to obtain a photocurable photosensitive pigment dispersion liquid. be able to. Further, if a thermal polymerization initiator is used instead of the above photopolymerization initiator, a thermosetting pigment dispersion liquid can be obtained.

Specific examples of the non-photosensitive film forming material include styrene-(meth)acrylic acid ester-based copolymers, soluble polyamide-based resins, soluble polyimide-based resins, soluble polyamide-imide-based resins, soluble polyester-imide-based resins, water-soluble Examples include aminopolyester resins, water-soluble salts thereof, water-soluble salts of styrene-maleic acid ester-based copolymers, water-soluble salts of (meth)acrylic acid ester-(meth)acrylic acid-based copolymers, and the like. it can.

The pigment colorant of the present invention may further contain a polymer dispersant. As the polymer dispersant, an acidic polymer dispersant and a basic polymer dispersant can be used. The blending amount of the polymer dispersant is preferably 2 to 100 parts by mass, and more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the pigment.

Next, further details of the pigment colorant of the present invention will be described by citing a pigment dispersion liquid for a black matrix of a color filter (pigment colorant for BM) as a typical example. To prepare a pigment colorant (photoresist) for BM, first, the above-mentioned pigment composition containing a black pigment such as a black azo pigment is added to a liquid containing a film-forming material and premixed. Then, dispersion treatment is performed to obtain a pigment colorant for BM. More specifically, adding and mixing a pigment composition uniformly ground using a dispersing machine such as a vertical medium disperser, a horizontal medium disperser, or a ball mill into a liquid containing a film-forming material. Thus, a pigment colorant for BM can be obtained. Further, a solution obtained by dissolving a black azo pigment and a pigment dispersant in sulfuric acid or the like is mixed with water, and a pigment composition containing the black azo pigment and the pigment dispersant is precipitated as a solid solution or a co-precipitate and separated. To do. The separated pigment composition is added to and mixed with a liquid containing a film-forming material or a polymer dispersant, and then milled and dispersed using a horizontal wet medium disperser (bead mill) such as Dynomill. A pigment colorant for BM can be obtained.

As a liquid containing a film-forming material used for preparing a pigment colorant for BM, a solution of a film-forming polymer contained in a conventionally known pigment dispersion for color filters can be used. Further, examples of the liquid medium used for the liquid containing the film-forming material include organic solvents, water, and mixed liquids of organic solvents and water. If necessary, conventionally known additives such as a dispersion aid, a leveling agent, and an adhesion promoter can be added to the pigment colorant for BM.

By using the above-described BM pigment colorant containing a black azo pigment dispersed with a pigment dispersant, a substantially electrically insulating black matrix (BM) for a CF substrate can be formed. The BM can be formed on the CF substrate by a method such as a photolithography method, a laser ablation method, an inkjet printing method, a printing method, a transfer method, or a sticking method using a pigment colorant for BM. ..

The film thickness of the BM is, for example, 0.5 to 3 μm, and normally may be 1 to 2 μm. Further, by using the above-mentioned pigment colorant for BM, it is possible to form a BM having a sufficient optical density. The optical density of the BM formed is, for example, 1.6 or more, and preferably 2.0 or more. Specific methods for giving the BM a function as a spacer include a method of forming the BM itself thickly, a method of stacking pixels on the BM, and a method of stacking a colorless resin film on the BM. ;and so on. Whichever method is used, the film thickness is preferably about 5 to 10 μm. After that, if a known colorant for forming chromatic color pixels is used, chromatic color pixels can be further formed on the CF substrate on which the BM is formed.

Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. Hereinafter, “part” and “%” are based on mass unless otherwise specified.

<Preparation of pigment dispersant>
(Example 1)
A solution was prepared by dissolving 30.5 parts of N-(4-methoxyphenyl)-2-hydroxy-11H-benzo[a]carbazole-3-carboxamide and 6.4 parts of sodium hydroxide in 800 parts of methanol. On the other hand, 13.9 parts of o-aminobenzenesulfonic acid was diazotized by a conventional method to obtain a solution of a diazonium salt. A solution of diazonium salt was added to the prepared solution, and a coupling reaction was carried out at 20 to 30°C for 5 hours. After filtering, washing with water, and drying, 43 parts of a blue-violet pigment dispersant (A) represented by the following formula (A) was obtained.

A peak with a molecular weight of 566.60 was detected by mass spectrometry using MALDI (Matrix Assisted Laser Desorption Ionization Method). The purity measured by high performance liquid chromatography (MODEL860-CO (manufactured by JASCO Corporation), column: YMCPack Pro C18 (manufactured by YMC)) was 96%. From the raw materials used, the result of mass spectrometry, and the result of high performance liquid chromatography, it was confirmed that the compound having the target structure was obtained.

(Example 2)
It is represented by the following formula (B) in the same manner as in Example 1 above, except that 13.9 parts of m-aminobenzenesulfonic acid was used instead of 13.9 parts of o-aminobenzenesulfonic acid. 42 parts of a blue-violet pigment dispersant (B) was obtained.

By mass spectrometry using MALDI, a peak with a molecular weight of 566.60 was detected. The purity measured by high performance liquid chromatography was 95%. From the raw materials used, the result of mass spectrometry, and the result of high performance liquid chromatography, it was confirmed that the compound having the target structure was obtained.

(Example 3)
In the same manner as in Example 1 above, except that 17.9 parts of 4-amino-1-naphthalenesulfonic acid was used instead of 13.9 parts of o-aminobenzenesulfonic acid, the following formula (C) was used. 46 parts of the blue-violet pigment dispersant (C) represented was obtained.

By mass spectrometry using MALDI, a peak with a molecular weight of 616.66 was detected. The purity measured by high performance liquid chromatography was 94%. From the raw materials used, the result of mass spectrometry, and the result of high performance liquid chromatography, it was confirmed that the compound having the target structure was obtained.

(Example 4)
N-(4-Methoxyphenyl)-2-hydroxy-11H-benzo[a]carbazole-3-carbamide Instead of 30.5 parts, N-(2-methyl-4-methoxyphenyl)-2-hydroxy-11H A violet-colored pigment dispersant (D) 44 represented by the following formula (D) in the same manner as in Example 1 described above except that 31.7 parts of benzo[a]carbazole-3-carbamide was used. I got a part.

By mass spectrometry using MALDI, a peak with a molecular weight of 580.62 was detected. The purity measured by high performance liquid chromatography was 94%. From the raw materials used, the result of mass spectrometry, and the result of high performance liquid chromatography, it was confirmed that the compound having the target structure was obtained.

(Example 5)
N-(4-Methoxyphenyl)-2-hydroxy-11H-benzo[a]carbazole-3-carbamide Instead of 30.5 parts, N-(2-methyl-4-methoxyphenyl)-2-hydroxy-11H Except that 31.7 parts of -benzo[a]carbazole-3-carbamide was used and 13.9 parts of m-aminobenzenesulfonic acid was used instead of 13.9 parts of o-aminobenzenesulfonic acid. In the same manner as in Example 1 above, 45 parts of a blue-violet pigment dispersant (E) represented by the following formula (E) was obtained.

By mass spectrometry using MALDI, a peak with a molecular weight of 580.62 was detected. The purity measured by high performance liquid chromatography was 94%. From the raw materials used, the result of mass spectrometry, and the result of high performance liquid chromatography, it was confirmed that the compound having the target structure was obtained.

(Example 6)
N-(4-Methoxyphenyl)-2-hydroxy-11H-benzo[a]carbazole-3-carbamide Instead of 30.5 parts, N-(2-methyl-4-methoxyphenyl)-2-hydroxy-11H -Using 31.7 parts of benzo[a]carbazole-3-carbamide, and using 17.9 parts of 4-amino-1-naphthalenesulfonic acid instead of 13.9 parts of o-aminobenzenesulfonic acid. Other than the above, in the same manner as in Example 1 above, 48 parts of a blue-violet pigment dispersant (F) represented by the following formula (F) was obtained.

By mass spectrometry using MALDI, a peak having a molecular weight of 630.68 was detected. The purity measured by high performance liquid chromatography was 94%. From the raw materials used, the result of mass spectrometry, and the result of high performance liquid chromatography, it was confirmed that the compound having the target structure was obtained.

<Preparation of black pigment dispersion>
(Example 7)
[Preparation of fine powder of black pigment]
A kneader equipped with a pressure lid was charged with 100 parts of a black pigment (black azo pigment, trade name “Chromofine Black A1103”, manufactured by Dainichiseika Kogyo Co., Ltd.), 500 parts of sodium chloride powder, and 50 parts of diethylene glycol. After premixing until a uniformly moist mass is formed, close the pressure lid, hold the pressure at 6 kg/cm ² and knead and grind the contents for 2 hours while controlling the temperature to 92-98°C. did. The obtained ground product was placed in 3,000 parts of water heated to 80° C., stirred for 1 hour, filtered and washed with water to remove sodium chloride and diethylene glycol, to obtain a press cake. A nonionic surfactant (200% based on the pigment) was added to the obtained presscake, diluted with water, and then ultrasonically dispersed to prepare a pigment dispersion. The average particle size of the fine particles in the pigment dispersion was about 90 nm, which was measured using a particle size analyzer (trade name "Model N-4", manufactured by Coulter, Inc.). The press cake was dried and crushed to obtain a finely divided black pigment powder.

[Preparation of black pigment dispersion]
25 parts of finely divided black pigment powder, 1.5 parts of the pigment dispersant (A) obtained in Example 1, benzyl methacrylate/methacrylic acid/2-hydroxyethyl methacrylate copolymer (molar ratio: 60/20/20, Weight average molecular weight 30,000) 10 parts, basic polymer dispersant (trade name "DISPERBYK-2001", manufactured by Big Chemie, solid content 46%) 5.5 parts and propylene glycol-1-monomethyl ether-2- 65 parts of acetate were mixed. After premixing, a horizontal bead mill was used for dispersion treatment to obtain a black pigment dispersion (Example 7).

(Examples 8 to 12)
Black pigment dispersions (Examples 8 to 12) were obtained in the same manner as in Example 7 except that the pigment dispersants (B) to (F) were used instead of the pigment dispersant (A).

(Comparative Example 1)
A black pigment dispersion (Comparative Example 1) was obtained in the same manner as in Example 7 except that the pigment dispersant (A) was not used.

(Comparative example 2)
In the same manner as in Example 7 above, except that the pigment dispersant (G) (phthalocyanine sulfonate (trade name “SOLSPERS-12000”, manufactured by Lubrizol)) was used instead of the pigment dispersant (A). A black pigment dispersion (Comparative Example 2) was obtained.

<Evaluation>
With respect to each of the obtained black pigment dispersions, (1) fluidity (storage stability), (2) gloss of the developed surface, and (3) foreign matter in the coating film were evaluated. The evaluation method is shown below. The evaluation results are shown in Table 1.

(1) Fluidity (storage stability)
Using an E-type viscometer, the viscosity (mPa·s) of the black pigment dispersion liquid was measured immediately after preparation (initial stage) and after standing at 25° C. for 1 month (after standing). The measurement conditions were temperature: room temperature (25° C.) and rotor rotation speed: 6 rpm. Then, "viscosity after standing/initial viscosity (%)" was calculated, and "storage stability" was evaluated according to the following criteria.
◯: “viscosity after leaving/initial viscosity” is 110% or less x: “viscosity after leaving/initial viscosity” exceeds 110%

(2) Using a gloss bar coater (winding thickness 0.45 mm) on the color-developing surface, the black pigment dispersion liquid was color-developed on the polypropylene film to form the color-developing surface. The gloss of the formed color-developing surface was visually observed, and was also observed using a gloss meter, and the "gloss of the color-developing surface" was evaluated according to the following criteria. It should be noted that it can be determined that the higher the gloss on the color development surface, the better.
◎: Very good ○: Good ×: Poor

(3) Foreign matter in coating film A black pigment dispersion was applied to a glass substrate using a spinner. After drying at 90°C for 2 minutes, it was heated at 230°C for 30 minutes to form a coating film. The surface (coated surface) of the coating film formed using a microscope (200 times) was observed to confirm the presence or absence of foreign matter, and "foreign matter in coating film" was evaluated according to the following criteria.
◎: No foreign matter ○: Slight foreign matter ×: Foreign matter

<Formation and evaluation of CF BM pattern>
(Example 13)
(1) Preparation of photosensitive black resist ink 40 parts of the black pigment dispersion obtained in Example 7, 5 parts of acrylated acrylic polyol photosensitive resin 60% propylene glycol-1-monomethyl ether-2-acetate solution, trimethylolpropane Triacrylate 2 parts, dipentaerythritol hexaacrylate 3 parts, photopolymerization initiator (ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O- (Acetyl oxime), trade name "Irgacure OXE02", manufactured by BASF) 1 part, and propylene glycol-1-monomethyl ether-2-acetate 51 parts were blended. The mixture was sufficiently stirred using a high-speed stirrer so as to be uniform, and then filtered with a filter having a pore size of 3 μm to prepare a photosensitive black resist ink.

(2) Evaluation of black coating film (resist film) A photosensitive black resist ink was applied onto a glass substrate using a spin coater. After predrying at 60° C., prebaking was performed. After exposure with a light amount of 400 mJ/cm using an ultrahigh pressure mercury lamp, post-baking was performed at 230° C. for 30 minutes to form a black coating film having a thickness of 2 μm. The transmittance of light from the long wavelength side of the visible light region of the formed black coating film to around 670 nm is 20% or less, and the transmittance of light of 780 nm reaches 82%, and then gradually increases to an equilibrium state. Became. In particular, the transmittance of light around 580 to 625 nm was extremely low and was 5% or less. Further, the formed black coating film had a volume resistivity of 10 ¹⁴ Ω·cm or more, and was found to be a highly insulating coating film.

(3) Formation of BM pattern A photosensitive black resist ink was applied onto a glass substrate using a spin coater, and then prebaked at 80° C. for 10 minutes to form a black coating film having a thickness of 2 μm. Using an ultrahigh pressure mercury lamp, exposure was performed with a light amount of 100 mJ/cm through a negative photomask pattern of BM pattern. After developing with an alkaline developer, washing and drying were performed to form a BM pattern (BM film). Since the formed BM film is a highly insulating coating film, it can be used as, for example, a BM film that retains the thickness of the liquid crystal layer instead of a spacer, and liquid crystals of the IPS system or the COA system can be constructed. .. Moreover, since it can sufficiently absorb visible light up to a long wavelength region, it can be suitably used as a BM of an LCD panel that employs an LED backlight.

(4) Preparation of Red, Green, Blue, Yellow, and Purple Pigment Dispersions Instead of Chromofine Black A1103, PR254 (diketopyrrolopyrrole red pigment), PR177 (anthraquinone red pigment), PG36 (copper phthalocyanine) Green pigment), PB15:6 (ε-type copper phthalocyanine blue pigment), PY185 (yellow pigment), and PV23 (dioxazine violet pigment), respectively, except that a known pigment derivative having a sulfone group is used. Pigment dispersions of respective colors were prepared in the same manner as in Example 7 described above.

(5) Preparation of Photosensitive Resist Ink of Each Color A pigment dispersion liquid using PR254 and a pigment dispersion liquid using PR177 were blended at a ratio of 8:2 to obtain a blend. A photosensitive red resist ink was prepared in the same manner as in the case of the photosensitive black resist ink described above, except that the obtained mixture was used instead of the black pigment dispersion liquid.

In addition, a pigment dispersion liquid using PG36 and a pigment dispersion liquid using PY185 were blended at a ratio of 6:4 to obtain a blend. A photosensitive green resist ink was prepared in the same manner as in the case of the photosensitive black resist ink described above, except that the obtained mixture was used instead of the black pigment dispersion liquid.

Furthermore, a pigment dispersion liquid using PB15:6 and a pigment dispersion liquid using PV23 were mixed in a ratio of 8:2 to obtain a mixture. A photosensitive blue resist ink was prepared in the same manner as in the case of the photosensitive black resist ink described above, except that the obtained mixture was used instead of the black pigment dispersion liquid.

(6) Formation of RGB pixels of CF The glass substrate on which the BM was formed was set on a spin coater. The prepared photosensitive red resist ink was spin-coated on a glass substrate and then prebaked at 80° C. for 10 minutes. Using a proximity exposure machine equipped with an ultra-high pressure mercury lamp, exposure was performed with a light amount of 100 mJ/cm ² through a photomask having a mosaic pattern. After developing and washing with a dedicated developing solution and a dedicated rinse, it was dried to form a mosaic red pattern on the glass substrate. Mosaic green patterns and blue patterns were formed in the same manner as above except that photosensitive green resist ink and photosensitive blue resist ink were used instead of the photosensitive red resist ink. As a result, a CF having BM and RGB pixels was obtained. The CF obtained had excellent CF characteristics.

<Preparation and evaluation of gravure printing ink>
(Example 14)
10.5 parts of the finely divided powder of the black pigment obtained in Example 7, 0.5 part of the pigment dispersant (A) obtained in Example 1, and 40% of the polyurethane resin in which the isocyanate terminated polyester was chain-extended with diamine 30 parts of a mixed solvent solution of methyl ethyl ketone:toluene (1:3) was mixed. 2 parts of a cationic polymer dispersant, 2.5 parts of a 40% toluene solution of a polycarbodiimide compound obtained by using tolylene diisocyanate, and 54.5 parts of a mixed solvent of methyl ethyl ketone:toluene:isopropyl alcohol (50:30:20). After addition, mixed well using a high speed stirrer. The pigment was dispersed using a horizontal continuous medium disperser using glass beads as a dispersion medium to prepare a black gravure printing ink. Using a gravure printing machine, the prepared gravure printing ink was applied to the polyamide film, the polyester film, and the polypropylene film for printing to obtain a black film. Each of the obtained black films was capable of shielding visible light and sufficiently transmitting near infrared rays.

<Production and evaluation of polycarbonate resin molded plate>
(Example 15)
20 parts of the finely divided black pigment powder obtained in Example 7, 1 part of the pigment dispersant (A) obtained in Example 1, and 80 parts of polycarbonate resin powder were thoroughly mixed using a Henschel mixer. Then, they were mixed and kneaded using a twin-screw extruder to obtain a masterbatch containing 20% of a black pigment. 2 parts of the obtained masterbatch and 100 parts of polycarbonate resin pellets were mixed using a Henschel mixer and then kneaded using a twin-screw extruder to obtain black resin pellets. The obtained resin pellets were molded using an in-line screw injection molding machine to obtain a black polycarbonate resin molded plate (black plate) having excellent pigment dispersibility. The obtained black plate shields visible light and sufficiently transmits near-infrared rays, and can be used for applications such as infrared ray transmission filters.

<Manufacturing and evaluation of acrylic resin molded plate>
(Example 16)
Using a Henschel mixer, 20 parts of finely divided black pigment powder obtained in Example 7, 1 part of the pigment dispersant (A) obtained in Example 1, and 80 parts of acrylic resin (polymethylmethacrylate) powder were used sufficiently. Mixed. Then, they were mixed and kneaded using a twin-screw extrusion kneader to obtain a masterbatch containing 20% of a black pigment. 2 parts of the obtained masterbatch and 100 parts of acrylic resin pellets were mixed using a Henschel mixer and then kneaded using an extruder to obtain black resin pellets. The obtained resin pellets were molded using an in-line screw injection molding machine to obtain a black acrylic resin molding plate (black plate) excellent in pigment dispersibility. The obtained black plate shields visible light and sufficiently transmits near-infrared rays, and can be used for applications such as infrared ray transmission filters.

<Preparation and evaluation of polyurethane coating>
(Example 17)
(1) Preparation of Polyurethane Coating Agent (Liquid) 40 parts of finely divided black pigment powder obtained in Example 7, 2 parts of pigment dispersant (A) obtained in Example 1, and 60 parts of adipic acid ester plasticizer Was sufficiently kneaded using a three-roll kneader to obtain a black pigment plasticizer-dispersed paste (black pigment toner). Further, 60 parts of titanium oxide white pigment and 40 parts of adipic acid ester plasticizer were sufficiently kneaded using a three-roll kneader to obtain a plasticizer dispersion paste of white pigment (white pigment toner). On the other hand, 100 parts of a methyl ethyl ketone dispersion of a polyether polyol/diphenylmethane diisocyanate polyurethane having a carboxy group (solid content: 30%), 5 parts of a methyl ethyl ketone solution of a polyether polyol/diphenylmethane diisocyanate polyurethane (solid content: 50%), and 2.5 parts of polycarbodiimide-based cross-linking agent (solid content: 20%) was thoroughly mixed to obtain a mixture. 1 part of a black pigment toner and 6 parts of a white pigment toner were added to the obtained mixture, and then they were sufficiently mixed to prepare a gray polyurethane coating liquid.

Further, a white polyurethane coating liquid was prepared in the same manner as above except that the white pigment toner was used instead of the black pigment toner. Further, a black polyurethane coating liquid was prepared in the same manner as described above except that the white pigment toner was not used and only the black pigment toner was used.

(2) Evaluation The gray polyurethane coating liquid prepared on the surface of the nylon woven fabric tent was applied at a rate of about 200 g/m ^2, and then dried to prepare a gray processed woven fabric. The produced woven fabric that reflects the heat rays of direct sunlight could be used for applications such as tents that prevent temperature rise. Further, after coating the prepared white polyurethane coating liquid as the undercoat, the prepared black polyurethane coating liquid was top-coated to obtain a polyurethane synthetic leather having a two-layer structure. The obtained synthetic leather reflects heat rays and could be used for applications such as automobile interiors.

<Production and evaluation of undiluted colored fiber>
(Example 18)
Using a Henschel mixer, 50 parts of a finely divided black pigment powder obtained in Example 7, 2.5 parts of the pigment dispersant (A) obtained in Example 1, and 50 parts of a lubricant (ethylene bis-stearamide powder). And mixed to obtain a powder colorant (dry color) having a pigment content of 50%. 1 part of the obtained dry color and 99 parts of polypropylene resin pellets were mixed using a Henschel mixer and then kneaded using a vent type 40 m/m extruder to give 0.5% black pigment 0.5%. A resin pellet containing the obtained resin pellet was obtained. The resin pellets obtained by using a melt spinning machine were spun to obtain a clear black polypropylene fiber (stock solution colored fiber) having a fineness of 10 denier and excellent pigment dispersibility. The woven fabric produced by using the obtained undiluted colored fiber was able to reflect the heat rays of direct sunlight, and could be used for applications such as parasols and curtains to avoid temperature rise.

<Manufacturing and evaluation of resin molded products>
(Example 19)
5 parts of a finely divided black pigment powder obtained in Example 7, 0.1 part of the pigment dispersant (A) obtained in Example 1, 20 parts of a titanium oxide white pigment, and 75 parts of a polyethylene resin powder were mixed with a Henschel mixer. Used and mixed to obtain a dry color. 1 part of the obtained dry color and 100 parts of polybutylene terephthalate (PBT) resin pellets were mixed using a Henschel mixer and then kneaded using an extruder to obtain black resin pellets. The obtained resin pellets were molded using an inline screw injection molding machine to obtain a black resin molded plate having excellent pigment dispersibility. The obtained resin-molded plate was capable of reflecting the heat rays of direct sunlight and could be used as a resin-molded product that avoids temperature rise.

<Production and evaluation of textile printing paste>
(Example 20)
71 parts of a press cake containing 25 parts of the finely divided powder of the black pigment obtained in Example 7, 1.5 parts of the pigment dispersant (A) obtained in Example 1, 10 parts of a nonionic pigment dispersant, and an antifoaming agent 1 Parts and 18 parts water were thoroughly premixed. Next, the pigment was dispersed using a horizontal continuous medium disperser using glass beads as a dispersion medium to prepare a high-concentration dispersion liquid (black color base) of a black pigment. 20 parts of prepared black color base, 25 parts of reactive alkyl acrylate latex (solid content 40%), 0.5 part of defoaming agent, 1 part of dispersant, 3 parts of oil-in-water type dispersion stabilizer for emulsification, mineral terpene 38 parts and 12.5 parts of water were emulsified and dispersed using a homogenizer (strong emulsification disperser) to obtain an oil-in-water type black emulsion paste. 2 parts of a carbodiimide-based cross-linking agent (solid content 40%) was added to the obtained black emulsion paste and mixed sufficiently to obtain a black printing paste. After printing the obtained black printing paste on the polyester-cotton blended fabric on the entire surface, it was cured at 120° C. for 15 minutes to obtain a black plain printing fabric. The obtained plain printing cloth was capable of reflecting heat rays.

Claims (6)

A pigment dispersant which is a compound represented by the following general formula (1).

(In the general formula (1), X represents an aromatic group having one or more sulfonic acid groups, and R ₁ and R ₂ are each independently a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or Indicates a hydroxyl group) The pigment dispersant according to claim 1, wherein X in the general formula (1) is a group represented by any one of the following general formulas (2) to (4).

(In the general formulas (2) to (4), * represents a bonding position with a nitrogen atom, Y independently represents a halogen atom, and n represents a number of 0 to 2.) A pigment composition comprising a pigment and the pigment dispersant according to claim 1 or 2. The pigment composition according to claim 3, wherein the content of the pigment dispersant is 0.5 to 40 parts by mass relative to 100 parts by mass of the pigment. A pigment colorant containing the pigment composition according to claim 3 or 4, and a film forming material. The pigment colorant according to claim 5, which is used for image display, image recording, gravure printing ink, writing ink, plastic, pigment printing, paint, or black matrix of a color filter.