JP2017021078A - Color filter pigment dispersion liquid, color filter coloring composition, color filter, and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter pigment dispersion liquid that allows color filters to have reduced thickness, little parallax color mixing, and superior color reproducibility of pixels, and which is capable of nicely dispersing pigments and is less susceptible to temporal degradation even at an increased pigment concentration, and to provide a color filter coloring composition using the same.SOLUTION: Provided is a color filter pigment dispersion liquid that contains an organic pigment, dispersant, and solvent and is characterized in that a total mass of calcium (Ca) and iron (Fe) contained in the color filter pigment dispersion liquid is no greater than 180 mass ppm with respect to a total mass of the color filter pigment dispersion liquid. Also provided are a color filter coloring composition and color filter produced using the same.SELECTED DRAWING: None

Description

  The present invention relates to a pigment dispersion for a color filter. More specifically, the present invention relates to a pigment dispersion for a color filter in which the total content of specific metal elements is defined, a coloring composition for a color filter containing the same, and It is related with the color filter obtained by using.

  A color filter used for a display or the like generally has a transparent substrate, a colored layer, a light-shielding portion, and the like. As a method for forming the colored layer, a pigment dispersion method, a dyeing method, an electrodeposition method, a printing method, and the like. Among them, the pigment dispersion method is widely used in terms of spectral characteristics, durability, pattern shape, accuracy, etc. (Patent Documents 1 and 2).

  In recent years, with the development of displays, the demand for liquid crystal displays, organic EL displays, etc. has increased, and accordingly, the performance of these displays has been improved with improved color rendering, contrast, brightness, color reproducibility, etc. Is strongly desired.

In recent years, the black matrix has been made thinner for higher definition of tablets, smartphones, etc., and the phenomenon of parallax color mixing, where the colors of adjacent pixels appear to be mixed when viewed from the side, has become a particular problem. .
In order to solve this problem, it is required to reduce the thickness of the color filter. Specifically, for example, it is required to achieve a film thickness of about 50% to 70% of the conventional film thickness.
On the other hand, high color rendering in a chromaticity range defined as “adobe RGB standard” and “DCI standard” (“DCI” is Digital Cinema Initiatives) is also required for the reproduced colors of pixels.

  Therefore, in order to reduce the thickness of the color filter and increase the color rendering of the pixels, it is necessary to increase the pigment concentration of the color filter coloring composition.

However, when trying to increase the pigment concentration of the color filter coloring composition or the pigment dispersion used therein, it may be difficult to disperse the pigment in the first place.
Furthermore, if the pigment dispersion used for the preparation of the color filter coloring composition is a pigment dispersion having a viscosity higher than a certain viscosity, the viscosity as the coloring composition is high and the coating is difficult or the temporal stability is high. Since it may not be obtained, it cannot be used substantially. As a result, there is a problem that the pigment concentration of the pigment dispersion or the color filter coloring composition cannot be increased.

  In other words, even if a color filter that satisfies the color performance as described above can be designed, a pigment dispersion having a viscosity higher than a certain viscosity cannot be used, so even if the pigment concentration is high, the viscosity becomes low after dispersion. There is a need for pigment dispersions that are stable over time.

In addition, the color filter coloring composition has a problem in that the development characteristics deteriorate when the color filter is produced due to the high pigment concentration.
That is, in order to increase the color density and the like of the color filter, there is a problem that it is difficult to achieve compatibility with the development characteristics at the time of manufacturing the color filter even if a color filter coloring composition having excellent dispersion performance can be obtained even at a high density. Also occurred.

  On the other hand, Patent Documents 3 to 6 are known for prescribing the content of a metal element in a color filter or a colored composition for producing a color filter.

Patent Document 3 defines the total amount of sodium ions (Na ⁺ ) and potassium ions (K ⁺ ) contained in R (red), G (green), B (blue), and BK (black) pixels. Thus, a technique for preventing contamination of a liquid crystal element or a semiconductor element adjacent to the color filter is disclosed.
Patent Document 4 discloses a technique for achieving a high light shielding rate and a low surface reflectance by defining the total amount of sodium (Na) and potassium (K) in a resin coated with carbon black for a black matrix. Has been.

Patent Document 5 describes a pigment dispersion that regulates the electrical conductivity and regulates the contents of sodium (Na), potassium (K), and magnesium (Mg). The color filter obtained in this way is said to have good display stability because of its excellent voltage holding ratio.
In Patent Document 6, C.I. I. An organic pigment composition for a color filter in which the content of sodium ion (Na ⁺ ), potassium ion (K ⁺ ), and magnesium ion (Mg ⁺ ) contained in Pigment Green 58 is specified is described. The color filter obtained in this way is said to be excellent in display response.

However, since the pigment dispersion for color filters for displays is required to have a very high degree of dispersion, the above-described technology is not yet sufficient, and further improvement is desired to solve the above-described problems. It was.
In particular, parallax color mixing has become a problem due to high definition, and high color rendering of pixels has been required, and in recent years, it has been required to reduce the film thickness of color filters. A pigment dispersion and a color filter coloring composition having excellent performance in image characteristics, developability at the time of producing a color filter, and the like have been desired.

JP 2007-133131 A JP 2009-244617 A JP-A-7-198928 Japanese Patent Laid-Open No. 9-071733 JP 2009-007432 A JP 2014-119487 A

The present invention has been made in view of the above-described background art, and its problem is that the thickness of the color filter is reduced, there is little parallax color mixing when viewed from the side, and the reproduced color of the pixel is also a constant color. An object of the present invention is to provide a pigment dispersion for a color filter having excellent characteristics such as achieving high color rendering in a temperature range.
In addition, the pigment dispersion for color filters having excellent viscosity stability, such as being able to disperse pigments well even when the pigment concentration of the coloring composition for color filters is increased, and being difficult to deteriorate with time even if the pigment concentration is increased. And providing a coloring composition for a color filter using the same.

  In addition, when a colored composition for a color filter is produced using a pigment dispersion, the pigment concentration of the colored composition for a color filter can be increased, and as a result, a dispersion performance that achieves a high color density can be obtained. An object of the present invention is to provide a coloring composition for a color filter that can achieve both the "dispersion performance for realizing a high color density" and the development characteristics at the time of producing the color filter.

  As a result of intensive research to achieve the above object, the present inventor has said that sodium (Na) or potassium (K) contained in the color filter pigment dispersion or the color filter coloring composition is extremely “Calcium (Ca), Iron (Fe), Magnesium (Mg), Aluminum (Al), Chromium (Cr)” which is a metal element other than a common metal element (hereinafter, this bracket is simply referred to as “specific metal element”) It has been found that, by reducing the content of (abbreviated), a pigment dispersion for color filter, a color composition for color filter, and a color filter, in which the above problems are solved, can be obtained.

In addition, the present inventor, when there is "the specific metal element" mixed in from the solvent, process water, equipment members, etc. used in the process of producing the organic pigment, the pigment dispersion during the production of the pigment dispersion It was found that the initial viscosity of the liquid was increased, the temporal stability was deteriorated, the development time was increased, and an appropriate pattern and good pixels could not be obtained.
Then, by reducing the mixing of the “specific metal element” in the organic pigment, the dispersant, and the solvent that are the raw materials for the color filter pigment dispersion (in particular, the “specific metal element” in the organic pigment The inventors have found that a pigment dispersion for color filter, a colored composition for color filter, and a color filter, in which the above-mentioned problems are solved, can be obtained by reducing mixing), and the present invention has been completed.

  That is, the present invention is a color filter pigment dispersion containing an organic pigment, a dispersant and a solvent, and the total mass of calcium (Ca) and iron (Fe) contained in the color filter pigment dispersion is The present invention provides a pigment dispersion for a color filter, which is 180 ppm by mass or less with respect to the entire pigment dispersion for a color filter.

  In the present invention, the total mass of magnesium (Mg), aluminum (Al) and chromium (Cr) contained in the color filter pigment dispersion is 200 ppm by mass or less based on the total color filter pigment dispersion. A pigment dispersion for a color filter as described above is provided.

  Further, the present invention is a colored composition containing the color filter pigment dispersion, a polymerization initiator and an alkali-soluble resin, the total of calcium (Ca) and iron (Fe) contained in the colored composition The present invention provides a coloring composition for a color filter, wherein the mass is 120 mass ppm or less with respect to the entire coloring composition.

  Moreover, this invention provides the color filter characterized by being obtained using said pigment dispersion liquid for color filters.

  In addition, the present invention provides a display device having the above color filter.

As described above, the contamination of liquid crystal elements and semiconductor elements adjacent to the color filter is prevented by avoiding the mixing of extremely common metal elements such as sodium (Na) and potassium (K), and the metal in the pigment coating resin. To achieve high light-shielding rate and low surface reflectance, or to specify the content of the metal in the color filter to increase the voltage holding ratio to improve display stability and response The technology is known.
That is, a technique for reducing specific metal elements and improving specific optical characteristics and electrical characteristics directly attributable to the mixing of the metal is known.

  However, the specific metal element is specified, and at the stage of the pigment dispersion, its mode (high concentration, etc.) and physical properties (low viscosity, dispersion stability, etc.) are improved, and finally it is excellent using it. A technique for obtaining a color filter is not known.

  That is, by defining the content of metal elements such as calcium (Ca) and iron (Fe), the content of metal elements such as magnesium (Mg), aluminum (Al), and chromium (Cr) It is known that a pigment dispersion having a low viscosity (appropriate viscosity) and excellent dispersion stability can be obtained even by a high pigment concentration, and as a result, a color filter having excellent image characteristics and development characteristics can be obtained. It is not done.

  According to the present invention, there is provided a pigment dispersion for a color filter that solves the above-mentioned problems and problems, can be dispersed well even when the concentration of the pigment contained in the pigment dispersion for a color filter is increased, and hardly deteriorates with time. be able to.

Further, when a color filter coloring composition of the present invention is used to produce a color filter coloring composition, the pigment concentration in the color filter coloring composition can be increased, resulting in a low film thickness. A color filter that achieves a high color density can be obtained.
In addition, when the color filter pigment dispersion of the present invention is used, it is possible to provide a coloring composition for a color filter that can obtain good dispersion performance and dispersion stability performance and also has good development characteristics at the time of producing the color filter. Can do.

  Particularly in recent years, in order to solve the above-mentioned problems, it is required to reduce the film thickness of the color filter. On the other hand, high color rendering in a certain chromaticity range is also demanded for the reproduced color of the pixel. When a color filter pigment dispersion is used, a color filter color composition and a color filter that achieves a reduction in the thickness of the color filter, a low color parallax, high color rendering, and excellent developability in patterning are provided. can do.

  Hereinafter, the present invention will be described, but the present invention is not limited to the following specific embodiments, and can be arbitrarily modified within the scope of the technical idea.

The “color filter pigment dispersion” of the present invention contains at least an organic pigment, a dispersant and a solvent, and the total mass of calcium (Ca) and iron (Fe) contained in the color filter pigment dispersion. Is 180 ppm by mass or less with respect to the entire pigment dispersion for the color filter.
Furthermore, the “coloring composition for color filter” of the present invention is a coloring composition containing the above-mentioned pigment dispersion, polymerization initiator and alkali-soluble resin, and is contained in the coloring composition. The total mass of iron and iron (Fe) is 120 mass ppm or less with respect to the entire coloring composition.
In the present invention, the “color filter pigment dispersion” may be simply abbreviated as “pigment dispersion”, and the “color filter coloring composition” may be simply abbreviated as “coloring composition”.

<Organic pigment>
The organic pigment used in the present invention is not particularly limited as long as it is a colored pigment including an achromatic color such as black, and can produce a desired color as an organic pigment for a color filter. Here, “for color filter” includes all colors for coloring a color filter, such as for a pixel portion and a black matrix portion.
Hereinafter, the “organic pigment” may be simply abbreviated as “pigment”.

  In addition, as the organic pigment used in the present invention, a lake pigment that can be dispersed by bonding various substituents to a dye or insolubilizing in a solvent by using a known lake (chlorination) technique. Also mentioned.

Here, organic pigments include achromatic pigments such as white, black, and gray. Specifically, blue pigments, green pigments, red pigments, yellow pigments, purple pigments, orange pigments, brown pigments, black pigments. Various color pigments such as pigments can be used.
Since the pigment dispersion of the present invention is used as a color filter material, it is mainly a blue pigment, a green pigment, a red pigment, and a black pigment. However, in order to adjust the transmission / absorption wavelength thereof, the pigment of the above color tone Is also used.
Among the above, a blue pigment, a green pigment, a red pigment, a yellow pigment, a purple pigment, and the like are preferable from the viewpoint of exhibiting the effect of the present invention.

  Below, the specific example of an organic pigment is shown with a pigment number. The following “CI” means a color index.

Examples of red pigments include C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 14, 15, 16, 17, 21, 22, 23, 31, 32, 37, 38, 41, 47, 48, 48: 1, 48: 2, 48: 3, 48: 4, 49, 49: 1, 49: 2, 50: 1, 52: 1, 52: 2, 53, 53: 1, 53: 2, 53: 3, 57, 57: 1, 57: 2, 58: 4, 60, 63, 63: 1, 63: 2, 64, 64: 1, 68, 69, 81, 81: 1, 81: 2, 81: 3, 81: 4, 83, 88, 90: 1, 101, 101: 1, 104, 108, 108: 1, 109, 112, 113, 114, 122, 123, 144, 146, 147, 149, 151, 166, 168, 169, 170, 172, 173, 174, 175, 176, 177, 178, 17 , 181, 184, 185, 187, 188, 190, 193, 194, 200, 202, 206, 207, 208, 209, 210, 214, 216, 220, 221, 224, 230, 231, 232, 233, 235 236, 237, 238, 239, 242, 243, 245, 247, 249, 250, 251, 253, 254, 255, 256, 257, 258, 259, 260, 262, 263, 264, 265, 266, 267 268, 269, 270, 271, 272, 273, 274, 275, 276 and the like.
Of these, C.I. I. Pigment Red 48: 1, 122, 168, 177, 202, 206, 207, 209, 224, 242, 254 and the like. I. Pigment red 177, 209, 224, 254 and the like.

Examples of blue pigments include C.I. I. Pigment Blue 1, 1: 2, 9, 14, 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 17, 19, 25, 27, 28, 29, 33, 35, 36, 56, 56: 1, 60, 61, 61: 1, 62, 63, 66, 67, 68, 71, 72, 73, 74, 75, 76, 78, 79 and the like.
Of these, C.I. I. Pigment blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, and the like. I. Pigment blue 15: 6.

Examples of green pigments include C.I. I. Pigment green 1, 2, 4, 7, 8, 10, 13, 14, 15, 17, 18, 19, 26, 36, 45, 48, 50, 51, 54, 55, 58, 59, and the like.
Of these, C.I. I. Pigment green 7, 36, 58, 59, and the like.

Examples of yellow pigments include C.I. I. Pigment Yellow 1, 1: 1, 2, 3, 4, 5, 6, 9, 10, 12, 13, 14, 16, 17, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 41, 42, 43, 48, 53, 55, 61, 62, 62: 1, 63, 65, 73, 74, 75, 81, 83, 87, 93, 94, 95, 97, 100, 101, 104, 105, 108, 109, 110, 111, 116, 117, 119, 120, 126, 127, 127: 1, 128, 129, 133, 134, 136, 138, 139, 142, 147, 148, 150, 151, 153, 154, 155, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 172, 17 174, 175, 176, 180, 181, 182, 183, 184, 185, 188, 189, 190, 191, 191: 1, 192, 193, 194, 195, 196, 197, 198, 199, 200, 202 , 203, 204, 205, 206, 207, 208, 213 and the like.
Of these, C.I. I. Pigment yellow 83, 117, 129, 138, 139, 150, 154, 155, 180, 185, 213, and the like. I. Pigment yellow 83, 138, 139, 150, 180, 185 and the like.

Examples of orange pigments include C.I. I. Pigment Orange 1, 2, 5, 13, 16, 17, 19, 20, 21, 22, 23, 24, 34, 36, 38, 39, 43, 46, 48, 49, 61, 62, 64, 65, 67, 68, 69, 70, 71, 72, 73, 74, 75, 77, 78, 79 and the like.
Of these, C.I. I. Pigment oranges 38 and 71, and the like.

Examples of purple pigments include C.I. I. Pigment Violet 1, 1: 1, 2, 2: 2, 3, 3: 1, 3: 3, 5, 5: 1, 14, 15, 16, 19, 23, 25, 27, 29, 31, 32, 37, 39, 42, 44, 47, 49, 50 and the like.
Of these, C.I. I. Pigment violet 19, 23, and the like. I. And CI Pigment Violet 23.

In the present invention, one kind of the above pigment may be used, or two or more kinds thereof may be used.
Further, when the pigment dispersion of the present invention is a pigment dispersion for a black matrix of a color filter, a black pigment can be used as the organic pigment.
Examples of the black pigment include carbon black. That is, in the present invention, carbon black is also included in the organic pigment.
The achromatic organic pigment such as black may be the achromatic pigment alone or may be a mixture with a colored pigment such as red, green and blue.

  From the viewpoint of chemical structure and light transmission spectrum, preferred organic pigments in the present invention include anthraquinone pigments such as Pigment Red 177; diketopyrrolopyrrole pigments such as Pigment Red 254; and azomethine pigments such as Pigment Yellow 150. Azo pigments such as pigment yellow 138; dioxazine pigments such as pigment violet 23; phthalocyanine pigments such as pigment blue 15: 6; benzimidazolone pigments such as pigment yellow 180; quinoxaline pigments such as pigment yellow 213; Pigment; isoindoline pigment; isoindolinone pigment; indanthrene pigment; perylene pigment;

  In particular, the organic pigment is one or more organic pigments selected from the group consisting of anthraquinone pigments, diketopyrrolopyrrole pigments, azo pigments, quinophthalone pigments, dioxane pigments, and phthalocyanine pigments in order to exhibit the effects of the present invention. It is particularly preferred.

  In the present invention, organic pigments having the same chemical structure skeleton, that is, the same system, may be used singly or in combination of two or more. Two or more types may be used across the system. Moreover, a mixed crystal may be sufficient.

Since the organic pigment having the above chemical structure is often used as an organic pigment for a color filter, a pigment dispersion at a high concentration is often required, and the dispersibility and developability by a specific metal element are often required. The effect of the present invention is particularly easy to achieve because the influence is great and the specific metal element is likely to be mixed in the manufacturing process.
Specifically, for example, Pigment Red 254, Pigment Red 177, Pigment Yellow 150, Pigment Yellow 185, Pigment Yellow 138, Pigment Yellow 139, Pigment Blue 15: 6, Pigment Violet 23, Pigment Green 58, or Pigment Green 59 are described above. Particularly preferred for reasons.

Moreover, as a dye used as the raw material of the dispersible lake pigment, it can be suitably selected from conventionally known dyes. Examples of such dyes include azo dyes, metal complex azo dyes, anthraquinone dyes, triphenylmethane dyes, xanthene dyes, cyanine dyes, naphthoquinone dyes, quinoneimine dyes, methine dyes, and phthalocyanine dyes.
As a guide, if the amount of the lake pigment dissolved in 10 g or less of the solvent (or mixed solvent) is 10 mg or less, the lake pigment (dye) can be dispersed in the solvent (or mixed solvent). Can be determined.

<< Acid dye derivative >>
It is preferable that the organic pigment in the present invention contains an acidic dye derivative because the effects of the present invention are easily achieved. When acidic dye derivatives are used, fine dispersion is possible, and when used for color filters, high dispersion stability, high contrast, high light transmittance, high brightness, pigment dispersion This is preferable because a liquid is obtained.
Moreover, when an acidic pigment derivative is used, the effect of reducing the specific metal element in the present invention is more exhibited, and the above effect can be achieved synergistically.

Here, the “acidic dye derivative” refers to a dye derivative having an acidic group in its chemical structure, and particularly preferably an anthraquinone pigment, a diketopyrrolopyrrole pigment, an azo pigment, a quinophthalone pigment, a dioxazine pigment, and a phthalocyanine pigment. It is a pigment derivative having one or more pigment skeletons selected from the group and having an acidic group.
Among acidic dye derivatives, a quinophthalone pigment derivative which has a pigment skeleton of a quinophthalone pigment and has an acidic group is more preferable in terms of improving dispersibility.

The acidic group of the pigment derivative is preferably at least one selected from the group consisting of a sulfo group, a sulfonamide group, a carboxy group, and a metal salt or ammonium salt of the functional group.
The average amount of acidic groups introduced per molecule of pigment is not particularly limited, but is preferably 0.5 to 5, more preferably 0.6 to 4, and 0.7 to 3.5. Particularly preferred.
By introducing acidic groups, fine dispersion can be achieved, and when used for a color filter, a pigment dispersion having high dispersion stability, high contrast, high light transmittance, and high brightness can be obtained. Therefore, by reducing the specific metal element, it is possible to achieve a synergistic effect and further obtain the effect.

The organic pigment in the present invention preferably contains a pigment and an acidic dye derivative. The acidic dye derivative interacts with the pigment, and is adsorbed on or taken into the pigment surface when producing pigment particles.
Also, by adsorbing on the surface of the pigment, the surface of the pigment is made acidic, and it acts as an intermediary with the pigment dispersant to increase the affinity with the pigment dispersant rather than the organic pigment itself.
Further, the acidic pigment derivative that interacts with the basic dispersant is adsorbed on the pigment surface, whereby the basic dispersant can be efficiently positioned on the pigment surface. As a result, fine dispersion and dispersion stabilization are possible, which is excellent when used for a color filter.

The content of the acidic dye derivative in the whole organic pigment in the present invention is not particularly limited, but is preferably 0.5 to 30 parts by mass, and 1 to 15 parts by mass with respect to 100 parts by mass of the pigment. Is more preferable, and 2 to 10 parts by mass is particularly preferable.
By setting the above lower limit value or more, stable dispersion and fine dispersion are possible, and there is a synergistic effect with the reduction of the specific metal element described above. By setting the upper limit value or less, the change in chromaticity due to excess of the acidic dye derivative Can be suppressed.

  In the present invention, one or more of the above acidic dye derivatives may be used as the organic pigment, and one or more of the above acidic dye derivatives may be used for one kind of pigment. Good.

The acidic dye derivative may be added to the pigment particle dispersion at any stage. However, in consideration of adsorbing or incorporating the acidic dye derivative on the pigment surface, a process for producing a pigment. In the process of synthesizing the pigment, during the process of solvent salt milling with a kneader or the like, during the process after the process, the pigment is dry-pulverized with an attritor or the like. It can be added during the process, during the dispersing process, during the treatment process after dispersion, and the like.
It can also be added to a good solvent or a poor solvent in the reprecipitation method, and can also be added after concentration or redispersion after precipitation of pigment particles.

  According to the present invention, since the dispersant is a (salt type) basic block type dispersant or a (salt type) basic graft type dispersant, which will be described later, the salt forming site is a pigment, and particularly Strongly adsorbable to acidic pigment derivatives adsorbed on the pigment surface, while the main and side chains of the polymer dispersant that has an affinity for the solvent improve the dispersibility of the pigment dispersion for color filters. Thus, the concentration of the organic pigment can be increased, the viscosity can be reduced, and the change in the pigment dispersion over time can be suppressed. As a result, the developability is improved in the evaluation of the color filter coloring composition.

<< Pigment particle size >>
The particle size of the organic pigment is not particularly limited, but is preferably 30 nm to 500 nm, more preferably 40 nm to 300 nm, and particularly preferably 50 nm to 200 nm.
If the particle size is too small, dispersibility and re-dissolvability may be reduced, and workability may be reduced due to contamination by fine powder.
On the other hand, if the particle size is too large, the dispersibility, dispersion stability, light resistance and the like deteriorate, and the effect of reducing the content of specific metals such as calcium (Ca) and iron (Fe) becomes difficult to appear. The effect of the invention is not achieved, and in particular, good contrast cannot be obtained.

  Here, “re-solubility” refers to the property that the solid content of the color filter coloring composition once dried dissolves again in the solvent. For example, if the coloring composition for the color filter adheres to the tip of the die lip when coating with a die coater, a solidified product is generated by drying. If it is not easy to do, part of the solidified material on the die lip peels off and easily adheres to the colored layer of the color filter, which causes a foreign matter defect.

<Dispersant>
The dispersant in the present invention can be appropriately selected from known dispersants and used, for example, cationic, anionic, nonionic, amphoteric, silicone-based, fluorine-based surfactants; polymers Dispersing agent; a low molecular dispersing agent can be used. Among these, a polymer dispersant (including a polymer surfactant) is preferable because it can be uniformly and finely dispersed.

Examples of the polymer dispersant include polymer dispersants such as modified polyurethane, modified polyacrylate, modified polyester, and modified polyamide.
Specifically, (co) polymers of “unsaturated carboxylic acid esters such as (meth) acrylic acid esters”; (parts of “(co) polymers of unsaturated carboxylic acid such as (meth) acrylic acid”) ) Amine salt, (partially) ammonium salt or (partially) alkylamine salt; (co) polymer of “unsaturated carboxylic acid ester such as (meth) acrylic acid ester having primary, secondary or tertiary amino group” , (Partial) salt of amino group of (co) polymer, (partial) acid-modified product of amino group of (co) polymer; “hydroxyl group-containing unsaturated carboxylic acid such as hydroxyl group-containing (meth) acrylate ester” Ester (co) polymers and their modifications; polyurethanes; unsaturated polyamides; polysiloxanes; long-chain polyaminoamide phosphates; containing poly (lower alkylene imines) and free carboxy groups Amides and their salts obtained by the reaction of Riesuteru; and the like.

<< High molecular dispersant and low molecular dispersant >>
The “dispersant” in the present invention is not particularly limited, and known polymer dispersants and low molecular dispersants can be used for pigment dispersion.

Examples of the polymer dispersant include, for example, a random type dispersant made of a random (co) polymer; a block type dispersant made of a block copolymer; ) Graft type dispersants composed of a graft (co) polymer having repeating units bonded thereto, and the like.
In addition, a salt-type dispersant in which at least a part of the structural units of the (co) polymer has a salt structure is also preferable. Such salt type applies to all of the above-mentioned random type dispersant, block type dispersant and graft type dispersant, and they are preferably used.

  Examples of the polymer dispersant include (co) polymers of unsaturated carboxylic esters such as poly (meth) acrylic acid esters; (co) polymers of unsaturated carboxylic acids such as poly (meth) acrylic acid ( (Partial) amine salt, (partial) ammonium salt and (partial) alkylamine salt; (co) polymer of hydroxyl group-containing unsaturated carboxylic acid ester such as hydroxyl group-containing poly (meth) acrylic acid ester or modified products thereof; polyurethanes Unsaturated polyamides; polysiloxanes; long-chain polyaminoamide phosphates; amides obtained by the reaction of poly (lower alkyleneimines) with free carboxy group-containing polyesters, salts thereof, and polyester groups in the side chain ( And a copolymer of (meth) acrylate.

  Among them, poly (meth) acrylate, sodium maleate-olefin copolymer, terminal carboxyl group-containing polyester (for example, Japanese Examined Patent Publication No. 54-34009); tetrakis (2-hydroxyalkyl) ethylenediamine is used as a starting material. Polyester having an acidic group and / or a basic group (JP-A-2-245231, etc.); a macromonomer (an oligomer having a polymerizable unsaturated group at one end), a monomer having a hydroxyl group, and a carboxy group-containing monomer are copolymerized A copolymer obtained by copolymerization of a macromonomer (an oligomer having a polymerizable unsaturated group at one end) and a monomer having a nitrogen atom (Japanese Patent Laid-Open No. Hei 8-259987). 10-339949 etc.) etc. are preferable.

Examples of the low molecular dispersant include an anionic compound having a sulfonic acid group, a carboxylic acid group, etc .; a cationic compound having a salt of an aliphatic amine, a quaternary ammonium salt, etc .; a non-ion having a hydroxyl group, an oxyethylene chain, etc. Compound; polymer compound; and the like.
Specific examples include sorbitan fatty acid esters, polyoxyethylene alkylamines, alkyldiamines, alkanolamine derivatives (US Pat. No. 3,536,510), and the like.

  Among the dispersants, a polymer dispersant is preferable, and among the polymer dispersants, a basic block type dispersant and / or a basic graft type dispersant is functionally separated from the pigment adsorption site and the solvent affinity site. In addition to “total content of calcium (Ca) and iron (Fe)” described later, and “total content of calcium (Ca) and iron (Fe)”, magnesium (Mg) and aluminum (Al) Combined with the above-mentioned acidic dye derivative, having a synergistic effect with the effects of the present invention such as dispersion stability, colored image properties, developability, etc., by making "the total content of chromium (Cr)" below a certain value It is preferable from the point of having a synergistic effect.

  Here, “the dispersant is a basic block type dispersant and / or a basic graft type dispersant” means that the dispersant is a basic block type dispersant, a basic graft type dispersant. Either a basic block type dispersant and a basic graft type dispersant in combination, or a basic block type dispersant and a dispersant that is also a basic graft type dispersant. Also means. Further, the combined use of a dispersant that is neither a basic block type dispersant nor a basic graft type dispersant is excluded.

<< Basic Block Dispersant >>
The “basic block type dispersant” means a monomer having a basic group such as amino group, monoalkylamino group, dialkylamino group, amide group; salts thereof; trialkylammonium group; And a dispersant composed of a block copolymer of another monomer different from the monomer (hereinafter abbreviated as “b monomer”), which may be a binary copolymer or a ternary or more A copolymer may be used. The “a monomer” includes those obtained by replacing the above “alkyl” with “aryl”, “aralkyl”, “alkenyl” and the like.

  The a monomer includes a quaternary ammonium base and / or a (meth) acrylate compound containing a secondary or tertiary amino group in which hydrogen bonded to nitrogen may be substituted with a substituent or a salt thereof. A tertiary amino group and / or a quaternary ammonium base is particularly preferable.

［一般式（１）中、Ｒ^１は水素原子又はメチル基、Ａは２価の連結基、Ｒ^２及びＲ^３は、それぞれ独立して、水素原子又はヘテロ原子を含んでもよい炭化水素基を表し、Ｒ^２及びＲ^３が互いに結合して環構造を形成してもよい。］ As said a monomer, what gives the structural unit represented by the following general formula (1), or the salt form (after-mentioned) of the structural unit represented by the following general formula (1) is more preferable. That is, in the present invention, the above-mentioned pigment dispersion for color filters, in which the dispersant is a basic block copolymer containing a structural unit represented by the following general formula (1) or a salt form thereof, is preferable.

[In General Formula (1), R ¹ is a hydrogen atom or a methyl group, A is a divalent linking group, R ² and R ³ are each independently a hydrocarbon group that may contain a hydrogen atom or a heteroatom. R ² and R ³ may be bonded to each other to form a ring structure. ]

Specifically, the salt is composed of, for example, a tertiary amino group such as a unit forming a basic block copolymer, and a salt formed with an acid such as a sulfonic acid compound or a phosphoric acid compound. The thing which was done is mentioned.
Further, a tertiary amino group such as dimethylaminoethyl (meth) acrylate, which is a unit forming a basic block copolymer, may be converted to a quaternary ammonium salt with an aryl halide, an aralkyl halide or the like.

  When the monomer a gives the repeating unit represented by the general formula (1), a compound that reacts with an amino group after appropriately copolymerizing with another polymerizable monomer, for example, a sulfonic acid compound, phosphorus It may be reacted with an acid compound such as an acid compound or a carboxylic acid compound; a halogen compound such as an aryl halide, an alkyl halide or an aralkyl halide;

  Examples of the sulfonic acid compound include compounds represented by the following general formula (2). That is, as the salt-formed compound, the block copolymer is a compound represented by the following general formula (2) in which at least a part of nitrogen of the structural unit represented by the general formula (1) becomes a cation. One or more compounds selected from the group consisting of an anion and a salt-type block copolymer formed by forming a salt thereof are preferably the above-mentioned pigment dispersions for color filters.

［一般式（２）において、Ｒ^ａは、炭素数１〜２０の直鎖、分岐鎖若しくは環状のアルキル基；置換基を有してもよいビニル基、フェニル基若しくはベンジル基又は−Ｏ−Ｒ^ｅを表し、Ｒ^ｅは、炭素数１〜２０の直鎖、分岐鎖若しくは環状のアルキル基；置換基を有してもよいビニル基、フェニル基若しくはベンジル基；又は炭素数１〜４のアルキレン基を介した（メタ）アクリロイル基を表す。］

[In General Formula (2), R ^a is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; a vinyl group, a phenyl group or a benzyl group which may have a substituent, or —O—R represents ^e, R ^e is, having 1 to 20 carbon atoms straight chain, branched chain or cyclic alkyl group; substituent optionally a vinyl group which may have a phenyl group or a benzyl group; or an alkylene of 1 to 4 carbon atoms It represents a (meth) acryloyl group via a group. ]

  Examples of the above “halogen compounds such as halogenated aryl, alkyl halide, and halogenated aralkyl” include compounds represented by the following general formula (3). That is, as the salt-formed compound, the block copolymer is a compound represented by the following general formula (3) in which at least a part of nitrogen of the structural unit represented by the general formula (1) becomes a cation. One or more compounds selected from the group consisting of an anion and a salt-type block copolymer formed by forming a salt thereof are preferably the above-mentioned pigment dispersions for color filters.

［一般式（３）において、Ｒ^ｂ、Ｒ^ｂ’及びＲ^ｂ”は、それぞれ独立に、水素原子；酸性基若しくはそのエステル基；置換基を有してもよい炭素数１〜２０の、直鎖、分岐鎖若しくは環状のアルキル基；置換基を有してもよいビニル基、フェニル基若しくはベンジル基；又は−Ｏ−Ｒ^ｆを表し、Ｒ^ｆは、置換基を有してもよい、炭素数１〜２０の直鎖、分岐鎖若しくは環状のアルキル基；置換基を有してもよい、ビニル基、フェニル基若しくはベンジル基；又は炭素数１〜４のアルキレン基を介した（メタ）アクリロイル基を表し、Ｘは、塩素原子、臭素原子又はヨウ素原子を表す。］
一般式（３）中のＸが、カウンターアニオン（Ｘ⁻）となり塩を形成する。

[In General Formula (3), R ^b , R ^{b ′,} and R ^{b ″} each independently represent a hydrogen atom; an acidic group or an ester group thereof; A chain, a branched chain or a cyclic alkyl group; a vinyl group which may have a substituent, a phenyl group or a benzyl group; or —O—R ^f , wherein R ^f is a carbon which may have a substituent, A linear, branched or cyclic alkyl group of 1 to 20; an optionally substituted vinyl group, phenyl group or benzyl group; or (meth) acryloyl via an alkylene group of 1 to 4 carbon atoms Represents a group, and X represents a chlorine atom, a bromine atom or an iodine atom.]
X in the general formula (3) becomes a counter anion (X ⁻ ) to form a salt.

  As said phosphoric acid compound, the compound represented by following General formula (4) is mentioned. That is, as the salt-formed compound, the block copolymer is a compound represented by the following general formula (4) in which at least a part of the nitrogen of the structural unit represented by the general formula (1) becomes a cation. One or more compounds selected from the group consisting of an anion and a salt-type block copolymer formed by forming a salt thereof are preferably the above-mentioned pigment dispersions for color filters.

［一般式（４）において、Ｒ^ｃ及びＲ^ｄは、それぞれ独立に、水素原子；水酸基；炭素数１〜２０の、直鎖、分岐鎖若しくは環状のアルキル基；置換基を有してもよい、ビニル基、フェニル基若しくはベンジル基；又は−Ｏ−Ｒ^ｅを表し、Ｒ^ｅは、炭素数１〜２０の、直鎖、分岐鎖若しくは環状のアルキル基；置換基を有してもよい、ビニル基、フェニル基若しくはベンジル基；又は炭素数１〜４のアルキレン基を介した（メタ）アクリロイル基を表す。ただし、Ｒ^ｃ及びＲ^ｄの少なくとも１つは炭素原子を含む。］

[In General Formula (4), R ^c and R ^d each independently have a hydrogen atom; a hydroxyl group; a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; and a substituent. , A vinyl group, a phenyl group or a benzyl group; or -O-R ^e , where R ^e is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; may have a substituent, A vinyl group, a phenyl group or a benzyl group; or a (meth) acryloyl group via an alkylene group having 1 to 4 carbon atoms. However, at least one of R ^c and R ^d contains a carbon atom. ]

  Specific examples of the a monomer include (meth) acrylic acid dialkylaminoalkyl ester, (meth) acrylic acid diarylaminoalkyl ester, (meth) acrylic acid diaralkylaminoalkyl ester, and (meth) acrylic acid. And dialkenylaminoalkyl esters thereof, salts thereof and the like. Examples of the compound used when forming “the salts thereof” include compounds represented by the above general formulas (2) to (4).

  More specifically, for example, tertiary amino group-containing compounds such as dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth) acrylate, diethylaminopropyl (meth) acrylate; Salts of group-containing compounds; Amides such as N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide (Meth) acryloylaminopropyltrimethylammonium chloride, (meth) acryloyloxyethyltrimethylammonium chloride, (meth) acryloyloxyethyltriethylammonium chloride, (meth) acrylic Yl salts oxyethyl benzyl dimethyl ammonium chloride quaternary ammonium group-containing compounds such as chloride; and the like.

  Particularly preferred are dimethylaminoethyl (meth) acrylate, sulfonate of dimethylaminoethyl (meth) acrylate, phenylphosphonate of dimethylaminoethyl (meth) acrylate, (meth) acryloyloxyethylbenzyldimethylammonium chloride, and the like. It is done.

  The basic block copolymer in which the a monomer is (co) polymerized or a salt-type dispersant thereof can be finely dispersed or stabilized when used for a color filter, increasing the pigment concentration. Can maintain good dispersion stability. That is, it is possible to increase the concentration of pigment dispersion and coloring composition, and to increase the color rendering, thinning, high contrast, good developability, good re-dissolvability, etc. of the color filter obtained by using it. The above-described effects of the present invention are easily exhibited due to a synergistic effect with limiting the content of.

The organic pigment is firmly adsorbed to the nitrogen site contained in the a monomer (preferably the structural unit represented by the general formula (1)) and has excellent pigment dispersibility, and is firmly adsorbed to the nitrogen site. The organic pigment surrounded by the dispersant is easily flown while being adsorbed by the dispersant during development, and the organic pigment is not left on the substrate, and the generation of the residue is easily suppressed.
Similarly, the organic pigment that is firmly adsorbed on the nitrogen site and surrounded by the dispersant is likely to flow while adsorbed on the dispersant by the re-dissolvable solvent.

Examples of the b monomer include, as aromatic group-containing monomers, acrylates such as benzyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, and phenoxyethyl (meth) acrylate; styrenes such as styrene Vinyl ethers such as phenyl vinyl ether; and the like.
Further, methyl (meth) acrylate, ethyl (meth) acrylate (n-propyl) (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic (Meth) acrylic acid ester monomers such as 2-ethylhexyl acid, glycidyl (meth) acrylate, and hydroxyethyl (meth) acrylate; vinyl acetate; acrylonitrile; allyl group-containing compounds such as allyl alkyl ether;

As the b monomer, a carboxy group-containing monomer is also preferable. The carboxy group-containing monomer refers to a monomer containing a copolymerizable unsaturated double bond and a carboxy group.
Examples of the carboxy group-containing monomer include (meth) acrylic acid, vinyl benzoic acid, maleic acid, maleic acid monoalkyl ester, fumaric acid, itaconic acid, crotonic acid, cinnamic acid, and (meth) acrylic acid dimer. .
Further, an addition reaction product of a monomer having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and a cyclic anhydride such as maleic anhydride, phthalic anhydride, cyclohexanedicarboxylic anhydride, etc .; ω-carboxy- Examples include polycaprolactone mono (meth) acrylate.
Examples of the carboxy group precursor include a carboxy group-containing monomer using an acid anhydride such as maleic anhydride, itaconic anhydride, and citraconic anhydride.
Among these, (meth) acrylic acid is particularly preferable from the viewpoints of copolymerizability, cost, solubility, and the like.

  A comprehensive reason for the selection of the b monomer is that it has an affinity for a solvent and enables fine dispersion and dispersion stabilization, particularly when used for a color filter.

  When the polymerization block containing a monomer or a salt thereof is “A”, and the polymerization block containing b monomer is “B”, the basic block dispersant in the present invention is an AB block copolymer, A- The block may be any of a B-A block copolymer, a B-A-B block copolymer, an A-B-A-B block copolymer, and more block copolymers, preferably an A-B block. It is a copolymer.

  In the block copolymer containing a monomer or a salt thereof, the block part containing a monomer or a salt thereof is adsorbed to the organic pigment, and the block part containing no a monomer or a salt thereof has an affinity for the solvent. The dispersibility of the organic pigment can be improved.

The weight average molecular weight (Mw) of the basic block copolymer in the present invention is not particularly limited, but is preferably in the range of 500 to 100,000, more preferably in the range of 1000 to 30,000. It is particularly preferably within the range of ˜20,000, and most preferably 4,000 to 15,000.
By being within the above range, it is possible to achieve both “wetting ability to disperse the pigment uniformly” and dispersion stability. In addition, when the pigment dispersant of the present application is used as a component of the coloring composition, if the upper limit is not more than the above value, the viscosity of the dispersion does not become too high, and developability and resolution do not deteriorate. When the lower limit is not less than the above value, sufficient dispersibility can be obtained.

Here, the weight average molecular weight is determined as a standard polystyrene conversion value by (Mw) and gel permeation chromatography (GPC).
The weight average molecular weight (Mw) of the basic block copolymer was measured using HLC-8120GPC manufactured by Tosoh Corporation and N-methylpyrrolidone added with 0.01 mol / L lithium bromide as an elution solvent. The calibration curve polystyrene standards are Mw377400, 210500, 96000, 50400, 20650, 10850, 5460, 2930, 1300, 580 (Easi PS-2 series manufactured by Polymer Laboratories) and Mw1090000 (manufactured by Tosoh Corporation). The measurement column is TSK-GEL ALPHA-M × 2 (manufactured by Tosoh Corporation).

The amine value is not particularly limited, but is preferably 15 to 200 mgKOH / g, more preferably 30 to 150 mgKOH / g, and particularly preferably 40 to 130 mgKOH / g.
If the amine value is too small, sufficient dispersion stability cannot be obtained, and if it is too large, the solubility in a solvent decreases.
The amine value can be determined according to JIS-K7237.

  Moreover, 0-50 mgKOH / g is preferable, as for an acid value, 1-30 mgKOH / g is more preferable, and 2-18 mgKOH / g is especially preferable. Within this range, the development characteristics are excellent. Further, if the acid value is larger than the above upper limit, “resist pattern peeling” may easily occur.

When the molecular weight, amine value or acid value is in the above range, it is easy to be dispersed, good dispersion stability can be maintained even when the pigment concentration is increased, the developability is good, and the metal content is limited. The above-described effects of the present invention are easily exhibited due to the synergistic effect.
As a result, a color display obtained using the pigment dispersion has a high contrast, a high light transmittance, and a high luminance display.

<< Basic Graft Type Dispersant >>
The “basic graft type dispersant” refers to a basic dispersant composed of a (co) polymer in which repeating units are bonded as side chains to the main chain.
Specifically, a side chain is synthesized first and then (co) polymerized, that is, a macromonomer having a polymerizable unsaturated group at one end (repeating a polymerizable unsaturated group at one end) Examples thereof include a dispersant made of a (co) polymer having a polymerization component such as an oligomer having a unit.
In addition, a dispersing agent made of a (co) polymer in which a main chain is first synthesized and then a repeating unit is bonded to a pendant (like a branch) as a side chain in some places. Can be mentioned.

The basicity of the “basic graft type dispersant” may be imparted in any way, but the basicity is preferably imparted by copolymerizing a basic nitrogen atom-containing monomer.
The basic monomer to be copolymerized is not particularly limited, and specific examples include the “a monomer” described in the section “Basic Block Dispersant”.

The “macromonomer having a polymerizable group unsaturated group at one end” is not particularly limited, and known ones can be used.
The polymerization component constituting the repeating unit in such a macromonomer is not particularly limited. Specifically, for example, styrene monomers such as styrene and α-methylstyrene; methyl (meth) acrylate, (meth) acrylic Ethyl acetate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, benzyl ( (Meth) acrylate monomers such as (meth) acrylate and hydroxyethyl (meth) acrylate; (meth) acrylamide, N-methylolacrylamide, N, N-dimethylacrylamide, N, N-dimethylaminoethylacrylamide, etc. ) Acrylamide mono Chromatography; vinyl acetate; acrylonitrile; allyl group-containing compounds such as allyl alkyl ether; and the like. The macromonomer in the present invention preferably has a unit in which the above polymerization component is polymerized.

In the “basic graft type dispersant”, in addition to the “macromonomer having a polymerizable group unsaturated group at one end” and the “basic monomer to be copolymerized”, other polymerizable monomers are copolymerized. Also good.
The “other polymerizable monomer” is not particularly limited, and specifically, for example, the “b monomer” described in the section of the “basic block dispersant” can be mentioned.

  The introduction rate of the macromonomer is not particularly limited, but it is preferably introduced at an average ratio of 0.1 to 20 in 100 repeating units of the main chain, and 0.3 to 10 It is particularly preferable to introduce them in proportions.

Although the molecular weight of the basic graft type dispersant in the present invention is not particularly limited, it is usually 1000 to 100,000, preferably 2000 to 40000, more preferably 3000 to 30000, particularly preferably as a weight average molecular weight (Mw) in terms of polystyrene. Is 4000-25000, more preferably 5000-20000.
Within the above range, it is easy to disperse, and fine dispersion can be achieved in the “final dispersion step when preparing a pigment dispersion”, or the dispersion time can be shortened. As a result, a color display obtained using the pigment dispersion has a high contrast, a high light transmittance, and a high luminance display.

<< Commercial item >>
In the present invention, the commercial product used as a dispersant is not limited, but specifically, for example, EFKA-4046, EFKA-4047, EFKA polymer 10, EFKA polymer 400, EFKA polymer 401, EFKA polymer 4300, EFKA polymer 4310, EFKA polymer 4320, EFKA polymer 4330 (above, manufactured by BASF Japan Ltd.), Disperbyk 111, Disperbyk 161, Disperbyk 165, Disperbyk 167, Disperbyk 182, Disp. Co., Ltd.), SOLPERSE24000, SOLPERSE2 000, SOLSPERSE28000 (manufactured by Lubrizol Corporation), Ajisper (registered trademark) PB821, PB822 (manufactured by Ajinomoto Fine-Techno Co.), and the like.

<Solvent>
The pigment dispersion of the present invention contains at least an organic pigment, a dispersant and a solvent, but the solvent is not particularly limited, and a known one is used.

Specifically, for example, alcohols such as methanol, ethanol and propanol; ethers such as tetrahydrofuran; propylene glycol monomethyl ether, propylene glycol dimethyl ether, propylene glycol methyl ethyl ether, propylene glycol monoethyl ether, propylene glycol diethyl ether and the like Alkylene glycol ethers; Dialkylene glycol ethers such as dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol methyl ethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether; tripropylene glycol monomethyl ether, tripropylene glycol Propylene glycol dimethyl ether Trialkylene glycol ethers such as tripropylene glycol methyl ethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol diethyl ether; alkylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; Dialkylene glycol monoalkyl ether acetates such as dipropylene glycol monomethyl ether acetate and dipropylene glycol monoethyl ether acetate; Trialkylene glycol monoalkyl ether acetates such as tripropylene glycol monomethyl ether acetate and tripropylene glycol monoethyl ether acetate; Torue Aromatic hydrocarbons such as xylene; ketones such as methyl ethyl ketone, methyl propyl ketone, methyl amyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone; ethyl 2-hydroxypropionate, 2-hydroxy-2 -Methyl methylpropionate, ethyl 2-hydroxy-2-methylpropionate, butyl 3-methoxyacetate, butyl 3-methyl-3-methoxyacetate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-2-methylbutanoate, And esters such as methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl acetate, butyl acetate, methyl lactate and ethyl lactate;
These solvents may be used alone or in combination of two or more.

  Among these, propylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, ethoxyethyl propionate, 3-methoxybutyl acetate, 3-methoxy-3-methyl-1-butyl acetate, and methyl 2-hydroxypropanoate are particularly preferable.

<Content ratio>
In the pigment dispersion for a color filter of the present invention, the content ratio of the organic pigment, the dispersant and the solvent is not particularly limited, but the following is preferable.
The dispersant is preferably 5 to 200 parts by weight, more preferably 10 to 150 parts by weight, particularly preferably 15 to 100 parts by weight, and most preferably 20 to 60 parts by weight with respect to 100 parts by weight of the organic pigment.
Moreover, 3-40 mass parts is preferable with respect to 100 mass parts of pigment dispersion liquid, 5-35 mass parts is more preferable, and 7-30 mass parts is especially preferable.

When the above-mentioned “content ratio of organic pigment and dispersant”, the pigment is easily dispersed, excellent dispersion stability is obtained, a pigment dispersion with a high pigment concentration is obtained, and the dispersion time can be shortened. .
As a result, the color filter obtained using the pigment dispersion exhibits the above-described effects, and can produce a high color rendering, high contrast, thin film, high light transmittance, and high brightness.

  Further, the above-mentioned “content ratio of organic pigment and solvent” is excellent in dispersibility, dispersion stability and the like, adjusted to a suitable viscosity, and at least a polymerization initiator and an alkali-soluble resin in the pigment dispersion of the present invention. (And preferably a polymerizable polyfunctional compound), when obtaining a colored composition, it is preferable because the content ratio is easily adjusted to an optimum value.

<Distribution method>
The above-mentioned organic pigment is dispersed and contained in a solvent in the presence of a dispersant. The effect of the present invention is particularly exerted when wet dispersed.

  In the present invention, the dispersion time is not particularly limited, but is preferably 0.01 to 50 hours, more preferably 0.02 to 30 hours, and 0.05 to 10 hours so that the dispersed particle diameter of the pigment is suitable. Is particularly preferred.

<Metal content in pigment dispersion>
The pigment dispersion for a color filter of the present invention is characterized in that the total mass of calcium (Ca) and iron (Fe) contained in the pigment dispersion is 180 ppm by mass or less with respect to the entire pigment dispersion. To do.
The total mass of calcium (Ca) and iron (Fe) is preferably as small as possible unless the cost is taken into consideration. Specifically, the total mass of the pigment dispersion is preferably 140 mass ppm or less, More preferably, it is 70 mass ppm or less, Especially preferably, it is 30 mass ppm or less, More preferably, it is 15 mass ppm or less, Most preferably, it is 5 mass ppm or less.

  If the “total mass of calcium (Ca) and iron (Fe) contained in the pigment dispersion liquid” is not more than the above upper limit, it can be dispersed well even if the pigment concentration contained in the pigment dispersion liquid is increased, and it can be dispersed over time. It is possible to obtain a pigment dispersion for a color filter that maintains good stability and hardly deteriorates with time despite a high pigment concentration.

In addition, when a colored composition for a color filter is produced using a pigment dispersion having a “total mass of calcium (Ca) and iron (Fe) contained in the pigment dispersion” of not more than the above upper limit, The pigment density can be increased, and as a result, a color filter that achieves a high color density even with a low film thickness can be obtained.
When such a pigment dispersion is used, it is possible to obtain a colored composition or a color filter that achieves a reduction in the thickness of the color filter, reduces color mixing of parallax, achieves high color rendering, and has excellent developability in patterning.

  In the coloring composition obtained by using the above-mentioned pigment dispersion with a limited amount of metal, the pigment concentration can be increased, good dispersion performance and dispersion stability performance can be obtained, and good development characteristics at the time of color filter production can be achieved. Is done. That is, for example, in the alkaline developer, the unexposed portion and the composition in the colored composition are easily dissolved together with the organic pigment.

  The lower limit of “the total mass of calcium (Ca) and iron (Fe) contained in the pigment dispersion liquid” is not particularly limited, but is preferably 1 mass ppm or more, and particularly preferably 3 mass ppm or more. If it is at least the above lower limit, the improvement in dispersibility and the improvement in developability are sufficient, so the cost required for excessive removal of the metal element is not incurred.

The pigment dispersion for a color filter of the present invention further has a total mass of magnesium (Mg), aluminum (Al) and chromium (Cr) contained in the pigment dispersion of 200 mass ppm with respect to the entire pigment dispersion. The following is preferable.
The total mass of magnesium (Mg), aluminum (Al), and chromium (Cr) contained in the pigment dispersion is more preferably 140 ppm by mass or less, particularly preferably 60 ppm by mass or less, based on the entire pigment dispersion. More preferably, it is 20 mass ppm or less.

  “The total mass of calcium (Ca) and iron (Fe) contained in the pigment dispersion” is not more than the above upper limit, and “magnesium (Mg), aluminum (Al) and chromium (Cr) contained in the pigment dispersion” If the total mass of ”is less than or equal to the above upper limit, it can be dispersed more favorably even if the concentration of the pigment contained in the pigment dispersion is increased, and the dispersion stability is further favorably maintained over time, and the pigment concentration is high. Nevertheless, it is possible to obtain a pigment dispersion for a color filter that hardly deteriorates with time.

“The total mass of calcium (Ca) and iron (Fe) contained in the pigment dispersion” is not more than the above upper limit, and calcium (Ca) is preferably not more than 160 mass ppm with respect to the entire pigment dispersion. 100 mass ppm or less is more preferred, 60 mass ppm or less is particularly preferred, and 30 mass ppm or less is even more preferred.
Further, the “total mass of calcium (Ca) and iron (Fe) contained in the pigment dispersion” is not more than the above upper limit, and iron (Fe) is not more than 30 mass ppm with respect to the entire pigment dispersion. Is preferable, 20 mass ppm or less is more preferable, 10 mass ppm or less is particularly preferable, and 5 mass ppm or less is further preferable.
The effect of this invention mentioned above is especially show | played as it is below the said upper limit.

"The total mass of calcium (Ca) and iron (Fe) contained in the pigment dispersion" is less than or equal to the above upper limit, and "calcium (Ca), iron (Fe) and magnesium (Mg) contained in the pigment dispersion" , “Total mass of aluminum (Al) and chromium (Cr)” is preferably 290 mass ppm or less, more preferably 260 mass ppm or less, particularly preferably 190 mass ppm or less, and 100 mass with respect to the entire pigment dispersion. More preferred is ppm or less, and most preferred is 50 mass ppm or less.
The effect of this invention mentioned above is especially show | played as it is below the said upper limit.

<Operation principle>
The principle of action that exhibits the effects of the present invention, such as improvement of dispersion stability, does not limit the scope of the invention, but is considered as follows.
That is, when calcium (Ca), iron (Fe), or the specific metal element is present in the vicinity of the organic pigment, it is presumed that the adsorption of the dispersant to the organic pigment is inhibited. In addition, it is estimated that the salt-type dispersant or acidic pigment derivative that contributes to improving the dispersibility forms a salt with the specific metal element, so that the dispersant or acidic pigment derivative cannot contribute to the improvement of the dispersibility. .

In addition, the above-described effect on the lowering of dispersibility is due to the presence of a divalent or higher cation such as a cation of a specific metal element rather than a monovalent cation such as sodium ion (Na ⁺ ) or potassium ion (K ⁺ ). There is a possibility that it is greater. Since the larger the valence of the metal cation, the higher the influence on the cohesion, “the upper limit of the total mass of Ca and Fe, both of which are metal elements having a valence of 2 or more, and furthermore, As a result of suppressing the “upper limit of the total mass of Mg, Al, and Cr, which are metal elements having a valence of 2 or more,” it is considered that “dispersion stability” is improved.
Further, it is more preferable to suppress the content of Fe, which is a metal element that gives a trivalent cation, and more preferably, Al, which is a metal element that also gives a trivalent cation, while suppressing the content of Fe. It is also considered that the suppression of the content of Cr and Cr greatly influenced the improvement of dispersion stability.

  Therefore, when the content of the specific metal element is small as defined in the present invention, the above-described obstacles are unlikely to occur, and therefore, it is presumed that dispersibility and developability described later are improved.

<Method for reducing metal content in pigment dispersion>
The pigment dispersion of the present invention contains at least an organic pigment, a dispersant, and a solvent. The metal is brought in from an organic pigment, a dispersant, a solvent, or the like that is a raw material for the pigment dispersion. Moreover, it can mix from the apparatus used for stirring, mixing, dispersion | distribution, etc. Therefore, it is preferable to prevent contamination of the metal from the raw materials and equipment.
In particular, since the amount of the metal brought from the organic pigment is large, it is more preferable to remove the metal from the organic pigment.
Furthermore, it is particularly preferable to reduce the amount of the metal from the organic pigment to be blended and from the colorant including the acidic pigment derivative.

The method for removing the metal in the organic pigment is not particularly limited, and may be removed in the pigment production process, or the metal may be removed from the produced pigment by a specific removal method.
The method for removing the metal from the produced pigment is preferably washing with a liquid such as alcohol or water, but in terms of cost, a washing method with water (hereinafter sometimes simply referred to as “washing”) is particularly preferred. It is mentioned as a thing.

In addition to “washing with liquid” such as “washing with water”, a metal for iron, such as iron or stainless steel, a member containing iron such as stainless steel; It is preferable not to use anything.
“Production device members” include balls in ball mills, beads and other media in bead mills; inner walls of pigment production containers, dispersion containers, surface treatment containers, drying containers, filtration containers, etc .; And the like.

  The removal method is particularly preferably washing with water. The washing with water may be carried out by suspending the pigment in a suspended state in water by a batch method or by a continuous method using running water.

The amount of the specific metal element contained in the organic pigment used in the pigment dispersion of the present invention can be achieved by adjusting or optimizing the following.
That is, as a means for reducing the amount of the specific metal element contained in the organic pigment, the content of the specific metal element contained in the washing water to be used is reduced (demineralized water with a sufficiently reduced amount of the metal is used. ), The washing is carried out by a continuous method using running water. If the washing is a batch method, the number of washings is increased. In either the continuous method or the batch method, the amount of washing water is increased with respect to the amount of pigment. Examples include increasing the pH of the washing water, adjusting the pH of the washing water, optimizing the stirring device during washing, and increasing the washing time.

Among these, a batch method in which the number of times of washing is increased, a continuous method using running water, or a method of raising the temperature of the washing water is particularly preferable.
The temperature of the washing water is more preferably in the range of 20 ° C. to 80 ° C. from the viewpoint that the predetermined metal can be efficiently removed, particularly preferably in the range of 30 ° C. to 70 ° C., and further preferably in the range of 40 ° C. to 60 ° C. .
Among them, a continuous method using running water is suitable. In this case, the amount of running water is preferably 30 parts by mass to 40,000 parts by mass, and 40 parts by mass to 20000 parts by mass with respect to 1 part by mass of the organic pigment. More preferably, 50 parts by mass to 10000 parts by mass are particularly preferable, and 60 parts by mass to 5000 parts by mass are even more preferable.

  Deionized water used for washing is prepared by treating raw water with a treatment agent such as strong acid or weak acid cation exchange resin, strong base or weak base anion exchange resin, ion exchange membrane, chelate resin, activated carbon, and antibacterial activated carbon. At least one selected from the above, preferably a combination of two or more of the above-mentioned treatment agents, or (distillation under reduced pressure) is preferable.

  Although washing with water is not particularly limited, the organic pigment produced by a known method is suspended in the deionized water, and a vacuum filter, a belt press, a centrifuge, a Nutsche funnel or the like is used. Using continuous methods of supplying deionized water continuously and washing continuously, filter presses, homogenizers (high pressure or low pressure homogenizers, ultrasonic homogenizers, etc.), sand mills, ball mills, roll mills, magnetic stirrers, etc. Thus, a batch method in which the organic pigment is washed while being dispersed is preferable.

  Above all, in order to reduce the mixing of metals such as calcium (Ca), iron (Fe), magnesium (Mg), aluminum (Al), chromium (Cr), etc. A homogenizer such as a sonic homogenizer is more preferable, and an ultrasonic homogenizer is particularly preferable from the viewpoints of reducing the amount of mixed metal and cost.

  Moreover, when washing | cleaning, disperse | distributing an organic pigment using the said stirrer, it is also preferable to supply water continuously and to process by a continuous method using flowing water. That is, it is also preferable to use a combination of the stirrer and the continuous method in order to reduce the specific metal element.

During the washing step, impurities such as metal salts, free metals, and other inorganic salts in the organic pigment are extracted from the deionized water. After washing, the suspension is filtered to remove impurities extracted into deionized water as a filtrate.
Next, the pigment wet cake obtained above is suspended in deionized water again, and if necessary, washing treatment is performed several times in the same process as above, and the impurities are removed as a filtrate each time. It is preferable to dry the wet cake of the pigment obtained and obtain an organic pigment for blending in the pigment dispersion. From the balance between the cleaning effect and the cost, the “several times” is preferably 2 to 50 times, more preferably 3 to 40 times, particularly preferably 4 to 30 times, and still more preferably 5 to 20 times. The (especially) preferable mass of the total deionized water used with respect to 1 mass part of organic pigments is the same as that of the case of the above-mentioned "continuous method using flowing water".

  That is, in a preferred embodiment of water washing, the organic pigment is washed by a batch method or a continuous method while using a stirrer such as “high pressure or low pressure homogenizer, sand mill, ball mill, roll mill, magnetic stirrer” while dispersing the organic pigment in water. After filtration, it is suspended in fresh water and washed with water. In the case of a batch method, the above steps are repeated a plurality of times, filtered and dried.

Further, the electric conductivity of the final filtrate in the washing step is preferably 20 μS / cm or less (particularly preferably 0.05 μS / cm to 5 μS / cm). If the water conductivity is such that the electrical conductivity exceeds the above range, the pigment may be insufficiently washed, and a pigment dispersion in which the amount of the metal is reduced to the range of the present invention may not be obtained.
That is, a pigment dispersion obtained by using the pigment by repeating the washing treatment to a level comparable to the electric conductivity of deionized water used for washing the pigment, and bringing the impurities in the pigment close to zero Exhibits the above-described effects of the present invention.

  The final washing step for the organic pigment used in the preparation of the pigment dispersion of the present invention can be confirmed by ICP (Inductively Coupled Plasma) emission spectroscopic analysis of the filtrate. The ICP measurement of the filtrate is carried out in the same manner as in the measurement example <quantitative determination of metal in the pigment dispersion> in the examples, except that the "pigment dispersion" in the measurement example is replaced with "filtrate".

The content in the final filtrate of the washing step is preferably such that both calcium (Ca) and iron (Fe) are below the detection limit, calcium (Ca), iron (Fe), magnesium (Mg), It is more preferable that both aluminum (Al) and chromium (Cr) are below the detection limit, and calcium (Ca), iron (Fe), magnesium (Mg), aluminum (Al), chromium (Cr), sodium ( It is particularly preferred that both Na) and potassium (K) are below the detection limit.
Here, the detection limit in the measuring method of the present invention (ICP (Inductively Coupled Plasma) emission spectroscopic analysis) is less than 0.01 ppm.

When the “content by ICP measurement” or “electric conductivity of the filtrate” of each metal atom that is an impurity in the filtrate exceeds the above upper limit, the content of the predetermined metal in the pigment dispersion is Since it may not fall within the scope of the present invention described above, a pigment dispersion having a high pigment concentration may not be prepared with a low viscosity (optimum viscosity) or dispersion stability may not be achieved.
For this reason, in the preparation of the pigment, it is preferable to repeat the washing treatment until the content of the metal atoms in the filtrate and the electrical conductivity of the filtrate are within the above numerical ranges.

<Aspect of pigment dispersion>
The average dispersion particle size of the pigment in the pigment dispersion of the present invention is not particularly limited, but is preferably 8 nm to 150 nm, more preferably 10 nm to 100 nm, and particularly preferably 12 nm to 70 nm.
Here, the average dispersed particle diameter of the pigment in the pigment dispersion (hereinafter sometimes simply referred to as “average dispersed particle diameter”) is the dispersion of pigment particles dispersed in a dispersion medium containing at least a solvent. The particle size is measured by a laser light scattering particle size distribution meter. For the measurement of particle size with a laser light scattering particle size distribution meter, the pigment dispersion is appropriately diluted to a concentration that can be measured with a laser light scattering particle size distribution meter (for example, 1000 times, etc.) ), A laser light scattering particle size distribution meter (for example, Nanotrack particle size distribution measuring device UPA-EX150 manufactured by Nikkiso Co., Ltd.) is measured at 23 ° C. by a dynamic light scattering method. The average dispersed particle size here is a volume average particle size.

  If the average dispersed particle size is too small, light resistance may decrease. On the other hand, if the average dispersed particle size is too large, the display using the color filter obtained using the pigment dispersion has low contrast. Or the light transmittance may be low, or the display may not be a high brightness.

  After the dispersion, it is usually filtered through a filter of 0.05 μm to 10 μm, preferably 0.1 μm to 5 μm, etc. to obtain the pigment dispersion of the present invention.

<Coloring composition for color filter>
The pigment dispersion of the present invention can be suitably used for a color filter material, a color filter coloring composition, a color filter photosensitive coloring resin composition, a liquid crystal display material, an organic EL display material, and the like. In particular, it is useful as a coloring composition for a color filter.
Another aspect of the present invention is a colored composition containing the color filter pigment dispersion of the present invention, a polymerization initiator, and an alkali-soluble resin, wherein calcium (Ca) and iron contained in the colored composition The total composition of (Fe) is 120 ppm by mass or less with respect to the entire coloring composition.
The alkali-soluble resin has a polymerizable functional group, and only the polymerizable functional group of the alkali-soluble resin may be polymerized, but the color filter coloring composition further contains a polymerizable polyfunctional compound. It is also preferable.

  The coloring composition for a color filter using the pigment dispersion of the present invention has the above-described effects of the present invention.

<< Alkali-soluble resin >>
The alkali-soluble resin is not particularly limited, and any resin that can be suitably developed with an alkaline developer can be used.
The alkali-soluble resin is preferably a copolymer having an acid group-containing monomer as a copolymerization component. Moreover, what introduce | transduced the acid group into the polymer later may be used.

  Here, as a monomer having an acid group, a monomer having a carboxy group such as (meth) acrylic acid or itaconic acid (methylene succinic acid); a monomer having a phenolic hydroxyl group such as 4-hydroxyphenylmaleimide; maleic anhydride, Monomers having a carboxylic anhydride group such as itaconic anhydride; and the like.

In addition, the alkali-soluble resin in the present invention has a radically polymerizable double bond introduced, the sensitivity is improved, the colored composition is image-exposed and photocured, and the unexposed part is developed, resulting in a strong From the point etc. which can form a simple coating film.
In order to introduce a radical polymerizable double bond, for example, a monomer capable of introducing a radical polymerizable double bond after polymerization is (co) polymerized, and then a radical polymerizable double bond as described later is introduced into the side chain. To do.
Examples of the “monomer capable of introducing a radically polymerizable double bond after polymerization” include, for example, monomers having a carboxy group such as (meth) acrylic acid and itaconic acid; carboxylic acid anhydrides such as maleic anhydride and itaconic anhydride Monomer having a group; and the like.

Examples of the compound used for introducing the radical polymerizable double bond include “epoxy group” such as glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, o- or m- or p-vinylbenzylglycidyl ether. And a radically polymerizable double bond ”.
A radical polymerizable double bond is introduced by reacting an epoxy group of a compound having “epoxy group and radical polymerizable double bond” with an acid group of “monomer capable of introducing a radical polymerizable double bond after polymerization”. The obtained alkali-soluble resin is obtained.

  In addition to the above, monomers that can be copolymerized with these can be used for the alkali-soluble resin. As the monomer (hereinafter abbreviated as “other monomer”), an ethylenically unsaturated double bond is used. Specific examples include styrene monomers such as styrene and α-methylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate (n-propyl acrylate), (meth) (Meth) such as isopropyl acrylate, butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, glycidyl (meth) acrylate, benzyl (meth) acrylate, hydroxyethyl (meth) acrylate, etc. Acrylic ester monomers; (meth) acrylamide, N-methylolacrylamide, (Meth) acrylamide monomers such as N, N-dimethylacrylamide and N, N-dimethylaminoethylacrylamide; vinyl acetate; acrylonitrile; allyl group-containing compounds such as allyl alkyl ether; maleimide monomers such as benzylmaleimide and N-phenylmaleimide And the like are copolymerized.

  The “monomer having an acid group”, “monomer capable of introducing a radical polymerizable double bond after polymerization”, “compound used for introducing a radical polymerizable double bond” and “other monomer” are used. In some cases, one type or two or more types are used, respectively, and are subjected to (co) polymerization or reaction.

The acid value of the alkali-soluble resin in the present invention is not particularly limited, but is preferably 30 to 200 mgKOH / g, more preferably 40 to 150 mgKOH / g, and particularly preferably 50 to 120 mgKOH / g.
When the upper limit of the acid value is not more than the above value, sufficient adhesion to the substrate can be obtained, and when the lower limit is not less than the above value, sufficient alkali developability can be obtained.

Although the molecular weight of alkali-soluble resin in this invention does not have limitation in particular, As a weight average molecular weight (Mw) of polystyrene conversion, it is 3000-25000 normally, Preferably, it is 4000-20000, Most preferably, it is 5000-15000.
When the upper limit of the weight average molecular weight (Mw) is not more than the above value, compatibility with other components is improved, developability is improved, and viscosity is not excessively increased. On the other hand, when the lower limit is not less than the above value, the adhesion with the substrate is improved.

<< Polymerizable polyfunctional compound >>
There is no limitation in particular as a polymerizable polyfunctional compound, A well-known polymerizable polyfunctional compound is used.
The “polymerizable polyfunctional compound” is not particularly limited as long as it has two or more polymerizable functional groups in one molecule. For example, polyester (meth) acrylate, polyether (meth) acrylate, urethane And polyfunctional (meth) acrylates such as (meth) acrylate and epoxy (meth) acrylate; polyfunctional allyl compounds such as diallyl phthalate and triallyl isocyanurate;

Among these, specific examples of the polyether (meth) acrylate include the following.
Examples of the bifunctional (meth) acrylate include linear alkanediol di (meth) acrylates such as 1,4-butanediol di (meth) acrylate and 1,6-hexanediol di (meth) acrylate; diethylene glycol di (meth) ) Acrylate, polyethylene glycol # 200 di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, polypropylene glycol # 400 di (meth) acrylate; pentaerythritol di (meth) acrylate, etc. Trivalent or higher alcohol partial (meth) acrylic acid ester; bisphenol-based di (meth) acrylates such as bisphenol A di (meth) acrylate and bisphenol F di (meth) acrylate; neopentyl Rikoruji (meth) acrylate; and the like.

  Examples of the trifunctional (meth) acrylate include glycerin tri (meth) acrylate, glycerin PO-modified tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane EO-modified tri (meth) acrylate, and trimethylolpropane. PO-modified tri (meth) acrylate, isocyanuric acid EO-modified tri (meth) acrylate, isocyanuric acid EO-modified ε-caprolactone-modified tri (meth) acrylate, 1,3,5-triacryloylhexahydro-s-triazine, pentaerythritol tri (Meth) acrylate, dipentaerythritol tri (meth) acrylate tripropionate, etc. are mentioned.

  Examples of tetrafunctional or higher functional (meth) acrylates include pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, succinic acid-modified dipentaerythritol penta (meth) acrylate, and pentaerythritol tri (meth) acrylate. Examples include succinic acid-modified products, dipentaerythritol penta (meth) acrylate monopropionate, dipentaerythritol hexa (meth) acrylate, tetramethylolethane tetra (meth) acrylate, oligoester tetra (meth) acrylate and the like.

  These polyfunctional monomers may be used individually by 1 type, and may be used in combination of 2 or more type. For example, a polyfunctional monomer having a carboxy group and a polyfunctional monomer having no carboxy group may be used in combination. From the point of improving heat resistance and adhesion, succinic acid modification of pentaerythritol tri (meth) acrylate having carboxy group, succinic acid modification of dipentaerythritol penta (meth) acrylate having carboxy group A thing etc. are preferable.

<< Polymerization initiator >>
Examples of the polymerization initiator include a thermal polymerization initiator and a photopolymerization initiator.
There is no limitation in particular as a photoinitiator, The well-known thing conventionally used with respect to radical polymerization can be used. In particular, it is preferable to use what is generally used for manufacturing color filters.

  As such a photopolymerization initiator, specifically, a compound that generates free radicals by the energy of ultraviolet rays, which is a benzoin derivative; a benzophenone derivative; a xanthone derivative such as xanthone, diethylthioxanthone, isopropylthioxanthone, or a thioxanthone derivative; Irgacure OX-01, Irgacure OXE-02 (manufactured by BASF Japan); oxime ester compounds such as ADEKA OPT-N-1919 (manufactured by Asahi Denka); chlorosulfonyl, chloromethyl polynuclear aromatic compounds, chloromethyl heterocyclic Compounds, halogen-containing compounds such as chloromethylbenzophenones; triazines; fluorenones; haloalkanes; redox couples of photoreducing dyes and reducing agents; organic sulfur compounds; peroxides; It is.

  Specific examples of the photopolymerization initiator include aromatic ketone compounds such as Michler's ketone, 4,4′-bisdiethylaminobenzophenone, 4-methoxy-4′-dimethylaminobenzophenone, 2-ethylanthraquinone, and phenanthrene; Benzoin ether compounds such as methyl ether, benzoin ethyl ether, and benzoin phenyl ether; Benzoin compounds such as methyl benzoin and ethyl benzoin; 2- (o-chlorophenyl) -4,5-phenylimidazole dimer, 2- (o-chlorophenyl) ) -4,5-di (m-methoxyphenyl) imidazole dimer, 2- (o-fluorophenyl) -4,5-diphenylimidazole dimer, 2- (o-methoxyphenyl) -4,5- Diphenylimidazole dimer, 2, , 5-triarylimidazole dimers, biimidazole compounds such as 2- (o-chlorophenyl) -4,5-di (m-methylphenyl) imidazole dimer; 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone, 2-trichloromethyl-5-styryl-1,3,4-oxadiazole, 2-trichloromethyl-5- (p-cyanostyryl) -1,3,4-oxa Halomethylthiazole compounds such as diazole and 2-trichloromethyl-5- (p-methoxystyryl) -1,3,4-oxadiazole; 2,4-bis (trichloromethyl) -6-p-methoxystyryl- s-triazine, 2,4-bis (trichloromethyl) -6- (1-p-dimethylaminophenyl-1,3-butadienyl) -s-triazine 2-trichloromethyl-4-amino-6-p-methoxystyryl-s-triazine, 2- (naphth-1-yl) -4,6-bis-trichloromethyl-s-triazine, 2- (4-ethoxy- Halomethyl such as naphth-1-yl) -4,6-bis-trichloromethyl-s-triazine, 2- (4-butoxy-naphth-1-yl) -4,6-bis-trichloromethyl-s-triazine, etc. s-triazine compounds; 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone, 1,2-benzyl- 2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,1-hydroxy-cyclohexyl-phenyl ketone, methyl benzoylbenzoate, 4-benzo Yl-4′-methyldiphenyl sulfide, benzylmethyl ketal, dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, ethanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1- (o-acetyloxime), 4-benzoyl- Methyldiphenyl sulfide, 1-hydroxy-cyclohexyl-phenyl ketone, 2-benzyl-2- (dimethylamino) -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2- (dimethylamino)- 2-[(4-methylpheny ) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, α-dimethoxy-α-phenylacetophenone, phenylbis (2,4,6-trimethylbenzoyl) phosphine oxide, 2-methyl- 1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone, 1,2-octadione and the like can be mentioned.

Moreover, the photoinitiator which has a tertiary amine structure can be used suitably. Since the photopolymerization initiator having a tertiary amine structure has a tertiary amine structure that is an oxygen quencher in the molecule, radicals generated from the photopolymerization initiator are not easily deactivated by oxygen, and sensitivity can be improved. It has the advantage that it can.
As a commercial item of the photoinitiator which has the said tertiary amine structure, Irgacure 907, Irgacure 369 (above, BASF Japan make), high cure ABP (made by Kawaguchi Pharmaceutical) etc. are mentioned, for example.

  The photoinitiator used for this invention is not limited to 1 type, You may use combining 2 or more types.

<< content ratio >>
The content ratio of the alkali-soluble resin and the polymerizable polyfunctional compound in the colored composition of the present invention is not particularly limited, but polymerization is performed with respect to 100 parts by mass of the alkali-soluble resin from the viewpoint of sensitivity, resolution, and developability. The functional polyfunctional compound is preferably 0 to 500 parts by mass, more preferably 10 to 300 parts by mass, and particularly preferably 20 to 200 parts by mass.
5-80 mass% is preferable with respect to solid content total amount of a coloring composition, and 10-40 mass% is more preferable. Moreover, 5-60 mass% is preferable with respect to this solid content whole quantity, and a polymeric polyfunctional compound has more preferable 10-40 mass%.

The content of the polymerization initiator is usually 0.2 to 30 parts by weight, preferably 0.5 to 20 parts by weight, particularly 100 parts by weight of the polymerizable polyfunctional compound, from the viewpoints of sensitivity, resolution and developability. Preferably it is 1-10 weight part.
3-40 mass% is preferable with respect to solid content total amount of a coloring composition, 7-35 mass% is more preferable, 10-30 mass% is especially preferable.

The organic pigment is preferably 3 to 65% by mass, more preferably 6 to 55% by mass, and particularly preferably 10 to 45% by mass with respect to the total solid content of the coloring composition.
Within this range, the effects of the present invention described above can be easily achieved, and in particular, coloring power, sensitivity, resolution, and developability are good. In particular, when the pigment dispersion of the present invention is used, the concentration of the organic pigment can be increased to the above upper limit, and therefore, an excellent color filter as described above can be produced.

<< Other ingredients >>
The coloring composition may further include, for example, a surfactant for improving wettability, a leveling agent, a silane coupling agent for improving adhesion, an antifoaming agent, a repellency inhibitor, an antioxidant, An anti-aggregation agent, an ultraviolet absorber and the like can be contained.

<< Metal content in coloring composition >>
The colored composition for a color filter of the present invention is a colored composition containing the pigment dispersion of the present invention, a polymerization initiator and an alkali-soluble resin, and contains calcium (Ca) and iron contained in the colored composition. The total mass of (Fe) is 120 mass ppm or less with respect to the whole coloring composition.

The total mass of calcium (Ca) and iron (Fe) contained in the coloring composition is preferably as small as possible unless the cost is taken into consideration, but is preferably 90 ppm by mass or less based on the whole coloring composition, 50 mass ppm or less is more preferable, 20 mass ppm or less is particularly preferable, 10 mass ppm or less is further preferable, and 3 mass ppm or less is most preferable.
Less than the above upper limit, because developability is good while maintaining dispersion stability, it is possible to increase the pigment concentration in the colored composition, and the pigment concentration in the solid content of the colored composition, the result A color filter that achieves a high color density even with a low film thickness can be obtained.

  Moreover, by preparing a coloring composition for a color filter using the pigment dispersion of the present invention, an excellent coloring composition that falls within the above-described metal-containing range can be prepared, and good dispersion performance and dispersion stability performance can be obtained. In addition, it is possible to provide a coloring composition for a color filter that is compatible with good development characteristics when producing the color filter.

  The lower limit of “the total mass of calcium (Ca) and iron (Fe) contained in the colored composition” is not particularly limited, but is preferably 0.5 mass ppm or more, particularly preferably 1 mass ppm or more. When it is at least the above lower limit, the developability is sufficiently good, and the cost required for removing the metal element is not excessive.

Furthermore, it is preferable that the total mass of magnesium (Mg), aluminum (Al), and chromium (Cr) contained in the colored composition is 135 mass ppm or less with respect to the entire colored composition. That is, the total mass of calcium (Ca) and iron (Fe) contained in the colored composition is 120 mass ppm or less with respect to the entire colored composition, and magnesium (Mg) and aluminum (Al) It is preferable that the total mass of chromium (Cr) be 135 mass ppm or less with respect to the entire coloring composition.
By preparing a coloring composition for a color filter using the pigment dispersion of the present invention, an excellent coloring composition that falls within the metal-containing range described above can be prepared.

The total mass of magnesium (Mg), aluminum (Al) and chromium (Cr) contained in the colored composition is more preferably 60 ppm by mass or less, particularly preferably 30 ppm by mass or less, and still more preferably. 20 ppm by mass or less.
The effect of this invention mentioned above is especially show | played as it is below the said upper limit.

Furthermore, “the total mass of calcium (Ca) and iron (Fe) contained in the colored composition” is not more than the upper limit, and “calcium (Ca), iron (Fe) and magnesium contained in the colored composition ( The total mass of (Mg), aluminum (Al), and chromium (Cr) ”is preferably 200 ppm by mass or less, more preferably 150 ppm by mass or less, and particularly preferably 100 ppm by mass or less, based on the entire coloring composition. 50 mass ppm or less is still more preferable, and 15 mass ppm or less is the most preferable.
The effect of this invention mentioned above is especially show | played as it is below the said upper limit.

<< principle of operation >>
Although the present invention is not limited to the extent that the following principle of action is applicable, the total content of calcium (Ca) and iron (Fe) contained in the colored composition (or the total content of specific metal elements) is large. If too much, the operation principle that the dispersion stability is deteriorated and the developability is deteriorated is estimated as follows.

That is, for example, the nitrogen moiety contained in the above-mentioned monomer a (preferably the structural unit represented by the general formula (1)) in the dispersant is adsorbed on the organic pigment to improve the dispersibility of the organic pigment, and the dispersion It is considered that the organic pigment firmly surrounded by the agent becomes easy to flow while adsorbed to the dispersant during development, and the generation of the residue derived from the organic pigment on the substrate is suppressed.
However, if the total mass of calcium (Ca) and iron (Fe) or the total content of the specific metal element is too large in the vicinity of the organic pigment (if there is too much calcium (Ca), iron (Fe) or the specific metal element) ), Salt-type dispersants and acidic dye derivatives that inhibit the adsorption of dispersants to organic pigments and contribute to improved dispersibility cannot interact with specific metal elements, and thus cannot contribute to improved dispersibility It is thought that.

  Further, when the content is too large, as described above, the organic pigment is not suitably surrounded by the dispersant, and therefore, during development, the developer is in the form of “organic pigment suitably surrounded by the dispersant”. It is considered that the residue derived from the organic pigment is easily generated on the substrate (development failure is likely to occur).

The coloring composition exhibits developability by containing an alkali-soluble resin, but the above-mentioned “salt-type dispersant not suitably surrounding the organic pigment” reduces the developability. Is also possible. Moreover, the influence of the cation of the specific metal element more than bivalence with respect to this alkali-soluble resin is also considered.
The influence on the deterioration of the developability is more than a divalent cation such as a cation of a specific metal element (divalent) rather than a monovalent cation such as sodium ion (Na ⁺ ) or potassium ion (K ⁺ ). There is a possibility that the total amount of only the above cations and the content including trivalent cations) is larger.

  Therefore, it is considered that the coloring composition obtained using the pigment dispersion having good dispersibility stability has improved developability.

<< Preparation of Coloring Composition for Color Filter >>
The coloring composition of the present invention is prepared by blending at least an alkali-soluble resin and a polymerization initiator in a pigment dispersion, and if necessary, a polymerizable polyfunctional compound and “other components”. Further, if necessary, a solvent can be further blended and mixed.
Since the coloring composition of the present invention is prepared and used in advance, a pigment dispersion can be effectively prevented and dispersed uniformly.

  In addition, since the pigment dispersion of the present invention can be set to a high pigment concentration while maintaining a suitable viscosity range and suitable dispersion stability, the coloring of the present invention obtained using the pigment dispersion of the present invention can be used. The composition can also achieve a high pigment concentration while maintaining a suitable viscosity range and suitable dispersion stability.

<Color filter>
The color filter usually has a transparent substrate, a light shielding part, and a colored layer. The color filter obtained by using the pigment dispersion of the present invention or obtained by using the coloring composition can achieve a high organic pigment concentration, high color rendering properties, high contrast, etc. Excellent developability when manufacturing color filters.

<< Colored layer >>
The colored layer is not particularly limited as long as it is formed by curing the above-described colored composition of the present invention. Usually, the colored layer is formed in an opening of a light-shielding portion on a transparent substrate described later, and the colored composition is formed. Depending on the type of pigment contained in the object, it is composed of three or more colored patterns.
In addition, the arrangement of the colored layers is not particularly limited, and for example, a general arrangement such as a stripe type, a mosaic type, a triangle type, or a four-pixel arrangement type can be used. Moreover, the width | variety, area, etc. of a colored layer can be set arbitrarily.

The thickness of the colored layer is controlled by adjusting the coating method, coating conditions, solid content concentration, viscosity, etc. of the colored composition, but is usually in the range of 1 to 5 μm.
When the pigment dispersion and the colored composition of the present invention are used, depending on the composition, the thickness can be reduced (for example, up to 80 to 50%) due to the high pigment concentration in the solid content. . As a result, the effects of high color rendering, no color mixing, high re-dissolvability, less foreign matter generation, and high productivity are exhibited.

The colored layer can be formed by the following method, for example.
First, the above-described coloring composition of the present invention is applied onto a transparent substrate described later using an application means such as a spray coating method, a dip coating method, a bar coating method, a roll coating method, a spin coating method, or a die coating method. A wet coating film is formed.
Next, the wet coating film is dried using a hot plate, an oven, or the like, and then exposed to light through a mask having a predetermined pattern to cause a photopolymerization reaction between the alkali-soluble resin and the polymerizable polyfunctional compound.
Examples of the light source used for exposure include ultraviolet rays such as a low-pressure mercury lamp, a high-pressure mercury lamp, and a metal halide lamp, and an electron beam.
Moreover, in order to promote a polymerization reaction after exposure, you may heat-process.

Next, it develops using a developing solution, a coating film is formed with a desired pattern by melt | dissolving and removing an unexposed part. As the developer, a solution in which an alkali is dissolved in water or a water-soluble solvent is usually used. The pigment dispersion and colored composition of the present invention are extremely excellent in developability.
After the development treatment, the developer is usually washed and the cured coating film of the resin composition is dried to form a colored layer. In addition, you may heat-process in order to fully harden a coating film after image development processing.

<< Light shielding part >>
The light shielding part in the color filter is formed in a pattern on a transparent substrate described later.
The pattern shape of the light shielding part is not particularly limited, and examples thereof include a stripe shape and a matrix shape.
Examples of the light-shielding portion include those obtained by dispersing or dissolving a black pigment in a binder resin; metal thin films such as chromium and chromium oxide. This metal thin film may be formed by laminating two layers of a CrOx film (x is an arbitrary number) and a Cr film.

  In the case where the light shielding part is obtained by dispersing or dissolving a black colorant in a binder resin, examples of a method for forming the light shielding part include a photolithography method, a printing method, and an inkjet using a resin composition for the light shielding part. The law etc. can be mentioned.

In the above case, when a photolithography method is used as a method for forming the light shielding portion, the binder resin may be, for example, an acrylate-based, methacrylate-based, polyvinyl cinnamate-based, or cyclized rubber-based reactive material. A photosensitive resin having a vinyl group is used.
In this case, a photopolymerization initiator, a sensitizer, a coatability improver, a development improver, a crosslinker is included in the light shielding part resin composition containing a black pigment such as carbon black or titanium black as a pigment and a photosensitive resin. Further, a polymerization inhibitor, a plasticizer, a flame retardant, etc. may be added.

  On the other hand, when the light-shielding part is a metal thin film, the light-shielding part can be formed by, for example, masking a resist pattern formed on the metal thin film by a photolithography method using a metal thin film formed by vacuum deposition or sputtering. Examples of the method include metal etching.

  The film thickness of the light-shielding part is set to about 0.05 to 0.4 μm in the case of a metal thin film, and 0.5 to 0.5 in the case where a black colorant is dispersed or dissolved in a binder resin. It is set at about 3 μm.

<< Transparent substrate >>
The transparent substrate in the color filter is not particularly limited as long as it is a base material transparent to visible light, and a transparent substrate used for a general color filter can be used. Specific examples include inflexible transparent rigid materials such as quartz glass, alkali-free glass, and synthetic quartz plates, or transparent flexible materials having flexibility such as transparent resin films and optical resin plates. It is done.
Although the thickness of the said transparent substrate is not specifically limited, Depending on a use, the thing of about 100 micrometers-1 mm can be used, for example.
The color filter of the present invention may be one in which, for example, an overcoat layer, a transparent electrode layer, an alignment film, a columnar spacer, or the like is formed in addition to the transparent substrate, the light shielding portion, and the colored layer. .

<Display device>
Another aspect of the present invention is a display device having the color filter described above. The display device is not particularly limited, and examples thereof include a liquid crystal display and an organic EL display.
The color filter obtained by using the coloring composition containing the pigment dispersion of the present invention is suitably used for a display device such as a liquid crystal display or an organic EL display.
Application of the color filter to a liquid crystal display or an organic EL display is usually performed by a known method.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples unless it exceeds the gist.

Preparation Example 1
<Preparation of Dispersant A (Dispersant Solution A)>
<< Synthesis of Block Copolymer A >>
A 500 mL four-neck separable flask was dried under reduced pressure, and then the interior was replaced with argon (Ar).
While flowing argon, 100 g of dehydrated tetrahydrofuran (THF), 2.0 g of methyltrimethylsilyldimethylketene acetal, 0.15 mL of 1 M acetonitrile solution of tetrabutylammonium-3-chlorobenzoate (TBACB), and 0.2 g of mesitylene were added and stirred. And mixed.
There, 36.7 g of methyl methacrylate was dripped over 45 minutes using the dropping funnel. As the reaction progressed, heat was generated, so the temperature was kept below 40 ° C. by cooling with ice. After 1 hour, 13.3 g of dimethylaminoethyl methacrylate (DMAEMA) was added dropwise as the “a monomer” over 15 minutes. After reacting for 1 hour, 5 g of methanol was added to stop the reaction.

The solvent was removed under reduced pressure to obtain block copolymer A.
The mass average molecular weight determined by GPC measurement (NMP, LiBr 10 mM) was 6000. The amine value was 95 mgKOH / g.
The obtained dispersant A was dissolved in propylene glycol monoethyl ether acetate (PGMEA) to prepare a 60% by mass block copolymer solution.

<< Step of Converting Block Copolymer to Salt (Preparation Step of Basic Block Dispersant) >>
Next, in a 100 mL round-bottomed flask, 5.0 parts by mass of the block copolymer solution obtained above was mixed with 23.76 parts by mass of PGMEA, and phenylphosphonic acid (Tokyo Kasei ( 0.94 parts by mass (0.5 molar equivalent based on the DMAEMA unit of the block copolymer) was added and stirred at a reaction temperature of 40 ° C. for 2 hours to obtain “dispersant A”. Then, it was appropriately diluted with PGMEA to prepare “dispersant solution A” having a solid content of 20% by mass.

Preparation Example 2
<Preparation of Dispersant B (Dispersant Solution B)>
<< Synthesis of Block Copolymer B >>
To a 500 mL round bottom 4-neck separable flask equipped with a condenser, addition funnel, nitrogen inlet, mechanical stirrer, digital thermometer, 250 parts by mass of dehydrated tetrahydrofuran (THF) and 0.6 parts by mass of lithium chloride were added. Sufficient nitrogen substitution was performed.
After cooling the reaction flask to −60 ° C., 4.9 parts by mass of butyllithium (15% by mass hexane solution), 1.1 parts by mass of diisopropylamine, and 1.0 parts by mass of methyl isobutyrate were injected using a syringe. .

As the “b monomer”, 2.2 parts by mass of 1-ethoxyethyl methacrylate (EEMA), 18.7 parts by mass of 2-hydroxyethyl methacrylate (HEMA), 12.8 parts by mass of 2-ethylhexyl methacrylate (EHMA) , 13.7 parts by mass of n-butyl methacrylate (BMA), 9.5 parts by mass of benzyl methacrylate (BzMA), and 17.5 parts by mass of methyl methacrylate (MMA) over 60 minutes using an addition funnel It was dripped.
30 minutes later, 26.7 parts by mass of dimethylaminoethyl methacrylate (DMAEMA) as the “a monomer” was dropped over 20 minutes.

After reacting for 30 minutes, 1.5 parts by mass of methanol was added to stop the reaction. The obtained precursor block copolymer THF solution was reprecipitated in hexane, purified by filtration and vacuum drying, diluted with PGMEA to obtain a solid content solution of 30% by mass.
32.5 parts by mass of water was added, the temperature was raised to 100 ° C., and the mixture was reacted for 7 hours to deprotect the structural unit derived from EEMA to obtain a structural unit derived from methacrylic acid (MAA).
The obtained block copolymer PGMEA solution was re-precipitated in hexane, purified by filtration and vacuum drying, and “A block containing the structural unit represented by the general formula (1)” and “carboxy group-containing monomer” A block copolymer B containing a derived structural unit and having a solvophilic B block ”was obtained.

The acid value of the block copolymer B was 8 mgKOH / g, and Tg was 38 ° C.
When the obtained block copolymer B was confirmed by GPC (gel permeation chromatography), the weight average molecular weight Mw was 7730. The amine value was 95 mgKOH / g.

<< Step of Converting Block Copolymer to Salt (Preparation Step of Basic Block Dispersant) >>
Next, salt formation was performed in the same manner as in Preparation Example 1 to prepare “Dispersant B”, which was further diluted with PGMEA to prepare “Dispersant Solution B” having a solid content of 20% by mass.
Similarly to Preparation Example 1, 0.5 mol equivalent of phenylphosphonic acid (manufactured by Tokyo Chemical Industry Co., Ltd.), which is a salt-forming component, was added to “DMAEMA unit that is a monomer” of block copolymer B.

Preparation Example 3
<Purification of organic pigments>
2.0 parts by mass of the organic pigment (R-1) shown in Table 1, 100 parts by mass of ion-exchanged water, placed in a beaker, and stirred for 10 minutes with an ultrasonic homogenizer by a batch method while maintaining at 30 ° C. Filtration was performed using filter paper.
Manufacturing and sales company: ADVANTEC
Product name: FIKTER PAPER QUANTITIVE ASHLESS
Standard: 5C, 150mm (100CIRCLES)

  In each case, the method of performing the above washing (washing) process twice is “Purification Method 1” (Example 3), the method of performing 20 times is “Purification Method 2” (Example 2), and the method of performing 30 times is “ Purification method 3 ”(Example 3, Example 9).

In addition, 2.0 parts by mass of the organic pigment (R-1) shown in Table 1 was used, a Nutsche funnel was used, and 30000 parts by mass of total ion-exchanged water was allowed to flow for 15 minutes, and suction was performed by a continuous method. Washed by filtration (washed with water). Subsequently, it filtered using the said filter paper.
The temperature of the ion exchange water that flowed was 30 ° C. This method was designated as “Purification Method 4” (Example 4).

Purified organic pigments were prepared using purification methods 1-4.
In Examples 5 to 8 and Comparative Examples 1 to 3, the organic pigment was not purified.
Using the obtained (purified) organic pigments, pigment dispersions were prepared as in Examples 1 to 9 and Comparative Examples 1 to 3 below.

Preparation Example 4
<Synthesis of Resin 1>
In a polymerization tank containing 40 parts by mass of BzMA, 15 parts by mass of MMA, 25 parts by mass of MAA, and 3 parts by mass of AIBN and 150 parts by mass of PGMEA, the mixture was added at 100 ° C. under a nitrogen stream at 3O 0 C. It was added dropwise over time. After completion of dropping, the mixture was further heated at 100 ° C. for 3 hours to obtain a polymer solution.
The weight average molecular weight of the polymer in this polymer solution was 7000.

Next, 20 parts by weight of GMA, 0.2 parts by weight of triethylamine, and 0.05 parts by weight of p-methoxyphenol are added to the obtained polymer solution and heated at 110 ° C. for 10 hours to Resin 1 was synthesized by reacting the carboxy group of methacrylic acid with the epoxy group of GMA.
During the reaction, air was bubbled through the reaction solution to prevent polymerization of GMA. The reaction was followed by measuring the acid value of the solution.

  The obtained resin 1 is a resin in which a side chain having an ethylenic double bond is introduced into the main chain of a polymer formed by copolymerization of BzMA, MMA and MAA using GMA, and has a solid content of 40 mass. %, Acid value 74 mgKOH / g, and weight average molecular weight 12000.

<< Name of Abbreviation >>
BzMA benzyl methacrylate MMA methyl methacrylate MAA methacrylic acid GMA glycidyl methacrylate AIBN azobisisobutyronitrile PGMEA propylene glycol monomethyl ether acetate

Preparation Example 5
<Synthesis of acidic dye derivatives>
374.76 parts by mass of fuming sulfuric acid having a sulfur trioxide content of 11% by mass was stirred while being cooled to 10 ° C., and 74.96 parts by mass of Pigment Yellow 138 was added. Subsequently, it stirred at 90 degreeC for 6 hours. The obtained reaction solution was added to 1600 parts by mass of ice water, stirred for 15 minutes, and then the precipitate was filtered.
The obtained wet cake was washed three times with 800 parts by mass of demineralized water. The wet cake after washing was vacuum dried at 80 ° C. to obtain a yellow pigment sulfonated derivative which is an acidic dye derivative. The molecular weight was measured by TOF-MS, and it was confirmed that it was a synthesis target.

Example 1
<Preparation of pigment dispersion>
16.7 parts by mass of “resin 1 (BzMA / MMA / MAA / GMA = 40/15/25/20 (mass ratio), weight average molecular weight 12000) solid content 40 mass% PGMEA solution” obtained in Preparation Example 4 Then, 8.1 parts by mass of the dispersant solution A and 62.2 parts by mass of PGMEA were stirred and mixed with a dissolver to be uniformly dissolved.

To this solution, 12.7 parts by mass of the (purified) organic pigment obtained in Preparation Example 3 and 0.3 part by mass of the acidic dye derivative obtained in Preparation Example 5 were added, and the particle size was 2.0 mm. The mass part was put into a mayonnaise bin, and shaken for 1 hour with a paint shaker (manufactured by Asada Tekko Co., Ltd.) as preliminary crushing.
Next, the zirconia beads having a particle size of 2.0 mm are taken out, 200 parts by mass of zirconia beads having a particle size of 0.1 mm are added, and similarly, the dispersion is performed for 4 hours with a paint shaker as the main crushing, and the red pigment dispersion is obtained. Prepared.

Examples 2-7, 9
<Preparation of pigment dispersion>
The pigment dispersions of Examples 2 to 7 and 9 were changed in the same manner as in Example 1 except that the organic pigment and the dispersant were changed as shown in Table 1 and the (purified) organic pigment obtained in Preparation Example 3 was used. A liquid was prepared. In Examples 5 to 8, the organic pigment used was not washed with water because the content of the specific metal element was small.

Example 8
<Preparation of pigment dispersion>
The organic pigment is changed to (G-1) as shown in Table 1, and the dispersant A (dispersant solution A) is changed to BYK21116 (basic block type dispersant manufactured by Big Chemie Japan) (dispersant in terms of solid content) A green pigment dispersion was prepared in the same manner as in Examples 1 to 7 except that the same mass as A and dispersant B was used. In Example 8, the organic pigment (G-1) used itself was not washed with water because the content of the specific metal element was small.

Comparative Examples 1-3
Except for changing the organic pigment as shown in Table 1 and using “an organic pigment that is not a purified organic pigment purified as in Preparation Example 3” (except that the organic pigment was not purified), Example 1 and Similarly, pigment dispersions of Comparative Examples 1 to 3 were prepared.

Examples 11-19
Comparative Examples 11-13
<Preparation of coloring composition for color filter>
Examples 11 to 19 use the pigment dispersions of Examples 1 to 9, respectively, and Comparative Examples 11 to 13 use the pigment dispersions of Comparative Examples 1 to 3, respectively, and adjust the solid content concentration with PGMEA as necessary. And each component was mixed with the composition shown below, and the coloring composition for color filters was prepared, respectively.

-Pigment dispersions prepared in Examples 1 to 9 and Comparative Examples 1 to 3 (solid content: 21.3% by mass): 52.7 parts by mass, respectively. The same resin as the resin 1 used in Example 1 Used as “alkali-soluble resin”, the alkali-soluble resin: 3.04 parts by mass. Polymerizable polyfunctional compound (manufactured by Toagosei Co., Ltd., Aronix M-403, photocurable polyfunctional monomer): 2.84 parts by mass Polymerization initiator (BASF, Irgacure 907, photopolymerization initiator): 0.89 parts by mass Surfactant (manufactured by DIC Corporation, MegaFuck F-559): 0.03 parts by mass PGMEA: 40.5 parts by mass

Measurement example <quantitative determination of metal in pigment dispersion>
Using an ICP (Inductively Coupled Plasma) emission spectrometer (Varian, Vista-PRO), calcium (Ca), iron (Fe), magnesium (Mg), aluminum (Al) and chromium (in the pigment dispersion) The content of Cr) was quantified.
The measurement sample was prepared as follows. That is, about 1 g (0.5 to 1.5 g) of the pigment dispersion is precisely weighed, heated on a burner and in an electric furnace (700 ° C.), incinerated, and then diluted with aqua regia, hot Heated on plate to dissolve.
The obtained solution was diluted with ultrapure water to make a total of 50.000 g as a measurement sample.

The detection limit of ICP emission spectroscopic analysis in the present invention is less than 0.01 ppm.
“0 mass ppm” in Tables 1 and 2 indicates that “0” is rounded off to “1”, that is, less than 0.5 mass ppm. Since the measurement sample is diluted about 50 times as described above, “0” in the table indicates that it is below the detection limit of the measurement apparatus.

Evaluation Example <Evaluation Method of “Dispersion Stability” of Pigment Dispersion>
The pigment dispersions prepared in each Example and each Comparative Example were stored at room temperature (25 ° C.), and the viscosity was measured after 1 day and 1 month after preparation. The viscosity was measured at 25.0 ± 1.0 ° C. using a vibration viscometer (manufactured by Seconic, VM-200T2), and a value 30 seconds after the start of measurement was adopted.

<< Criteria >>
The viscosity after 1 day of preparation was compared with the viscosity after storage for 1 month and determined as follows.
A: Viscosity change within 3% A: Viscosity change exceeds 3% and within 5% B: Viscosity change exceeds 5% and within 7% C: Viscosity change exceeds 7% and within 10% D: Viscosity Change exceeds 10%

  The results are shown in Table 1. If the change in viscosity is within 7%, that is, if the “dispersion stability” is “B” or more, it is evaluated as being excellent in stability and at a practical level.

<Evaluation method of “optical characteristics” of coloring composition for color filter>
The colored composition obtained in each example and each comparative example was formed on a glass substrate (NH Techno Glass Co., Ltd., “NA35”) using a spin coater and a desired color (red colored layer) after post-baking. : X = 0.650 with a C light source, green colored layer: y = 0.450, yellow colored layer: y = 0.500. After heating and drying on an 80 ° C. hot plate for 3 minutes, ultraviolet rays of 60 mJ / cm ² were irradiated using an ultrahigh pressure mercury lamp, and then post-baked for 25 minutes in a 230 ° C. clean oven.

The contrast, chromaticity (x, y), and luminance (Y) of the obtained colored film were measured. Contrast was measured using “Contrast measuring device CT-1B” manufactured by Aisaka Electric Co., Ltd., and chromaticity and luminance were measured using “Microspectral light measuring device OSP-SP200” manufactured by Olympus Corporation.
The results are shown in Table 2.

<< Criteria >>
The contrast is evaluated to be excellent if the red colored layer is 12000 or more, the green colored layer is 18000 or more, and the yellow colored layer is 10000 or more.

<Method for Evaluating “Developability” of Coloring Composition for Color Filter>
The coloring composition for a color filter obtained in each example and each comparative example was applied on a glass substrate (NH Techno Glass Co., Ltd., “NA35”) using a spin coater, and then a hot plate was used. And dried at 80 ° C. for 3 minutes.
This colored layer is exposed to ultraviolet light of 60 mJ / cm ² using an ultrahigh pressure mercury lamp through an independent fine line pattern photomask having a line width of 1 μm to 100 μm, whereby a thickness of 2.0 μm is formed on the glass substrate. A colored layer was formed.

  Next, 0.05 mass% potassium hydroxide (KOH) aqueous solution is used as a developer, spin-developed, contacted with the developer, washed with pure water, developed to form a pattern, and developability Evaluated.

  In the development process, the time until the unexposed area was dissolved and removed was measured. The end of development was observed visually and the development time was determined according to the following criteria.

<< Criteria >>
AA: Less than 40 seconds A: 40 seconds or more and less than 60 seconds B: 60 seconds or more and less than 80 seconds C: 80 seconds or more and less than 120 seconds D: 120 seconds or more

The results are shown in Table 2.
If the development time is less than 40 seconds (AA), the “development” is particularly excellent, and if the development time is 40 seconds or more and less than 60 seconds (A), the “development” is more excellent, and the development time is If it is 60 seconds or more and less than 80 seconds (B), “developability” is excellent, and all of AA, A, and B are good and determined to be at a practical level.
On the other hand, if the development time is 80 seconds or longer (C, D), “developability” is inferior, and it is determined that the development level is not practical.

In Table 1, the organic pigment is as follows.
“R-1”: Color index R177, manufactured by BASF Corporation, chromophthaled red A3B.
“R-2”: Color index R177, manufactured by BASF, chromophthaled red A2B.
“R-3”: Color index R177, manufactured by BASF, Irgadine Red A2BN.
“R-4”: Color index R177, manufactured by Yuri Kagaku Co., Ltd., FAST REDA3B.
“Y-1”: Color index Y138, manufactured by BASF, Paliotor Yellow K0961HD.
“G-1” is a color index G58, which is FASTOGEN Green A110 manufactured by DIC Corporation.

The contents of sodium (Na) and potassium (K) are not shown in Table 1, but were almost the same in all examples.
Although not shown in Table 1, in Examples 1 to 9, although the pigment concentration was high, the initial viscosity of the pigment dispersion was as low as 20 mPa · s or less and was in the practical range.
The viscosity was measured at 25.0 ± 1.0 ° C. using a vibration viscometer (manufactured by Seconic, VM-200T2). If the viscosity of the pigment dispersion is 20 mPa · s or less, it is within the practical range.

<Results concerning pigment dispersion>
As can be seen from Table 1, in Examples where the total mass of calcium (Ca) and iron (Fe) contained in the color filter pigment dispersion is 180 mass ppm or less with respect to the entire color filter pigment dispersion, Also, the dispersion stability was “AA”, “A” or “B” determination, which was a practical level.
On the other hand, in all comparative examples in which the total mass of calcium (Ca) and iron (Fe) is greater than 180 ppm by mass with respect to the entire pigment dispersion for the color filter, the dispersion stability is determined as “C” or “D”. And did not reach the practical level.
Moreover, it turned out that the said result can be said irrespective of the kind of pigment. Further, even when the total concentration of calcium (Ca) and iron (Fe) is lowered by washing (Examples 1 to 4 and 9), even when the total concentration is low from the beginning (Examples 5 to 8), the dispersion stability It turns out that the nature is high. Moreover, it turned out that the said tendency can be said irrespective of the kind of pigment.

  Further, before washing with water, the total concentration of calcium (Ca) and iron (Fe) is more than 180 ppm by mass with respect to the entire pigment dispersion for color filter, and the dispersion stability is “C”. 1 to 4 and 9 in which the total concentration of calcium (Ca) and iron (Fe) in the pigment dispersion is reduced to 180 mass ppm or less by washing the organic pigment (R-1) with water are all dispersible. “A” or “AA” was determined.

When the number of washing (washing) was increased, the dispersion stability was improved (Examples 1 to 3), and when the washing (washing) was performed by a continuous method, the dispersion stability was excellent (Example 4).
Moreover, when Example 3 and Example 9 which unified the organic pigment and the refinement | purification method and changed only the dispersing agent are compared, although all are "AA" determination, the direction of Example 9 using the dispersing agent B is more. Dispersion stability was superior to that of Example 3 using Dispersant A.

<Results on Colored Composition for Color Filter>
Further, as can be seen from Table 2, an example in which the total mass of calcium (Ca) and iron (Fe) contained in the color filter coloring composition is 120 ppm by mass or less with respect to the color filter coloring composition as a whole. In either case, the developability was judged as “AA”, “A” or “B”, which was excellent or at a practical level.
On the other hand, in all the comparative examples in which the total mass of calcium (Ca) and iron (Fe) is more than 120 mass ppm with respect to the entire color filter coloring composition, the developability is determined as “C” or “D”. Yes, it did not reach the practical level. Moreover, it turned out that the said tendency can be said irrespective of the kind of pigment.

  Moreover, when Example 13 and Example 19 which unified the organic pigment and the refinement | purification method and changed only the dispersing agent are compared, Example 13 using the dispersing agent B is Example 13 using the dispersing agent A. The developability was better and the judgment was “AA”.

  The pigment dispersion having a specific metal content of the present invention and the coloring composition using the same have high pigment concentration, low viscosity, and high dispersion stability, so that the thickness of the color filter can be reduced. Therefore, it is widely used for manufacturing various displays and the like.

Claims (10)

  A color filter pigment dispersion containing an organic pigment, a dispersant, and a solvent, wherein the total mass of calcium (Ca) and iron (Fe) contained in the color filter pigment dispersion is the color filter pigment dispersion. A pigment dispersion for a color filter, wherein the pigment dispersion is 180 ppm by mass or less with respect to the total liquid.   The total mass of magnesium (Mg), aluminum (Al) and chromium (Cr) contained in the color filter pigment dispersion is 200 ppm by mass or less based on the total color filter pigment dispersion. The pigment dispersion for color filters according to 1. The pigment dispersion for a color filter according to claim 1 or 2, wherein the dispersant is a basic block copolymer containing a structural unit represented by the following general formula (1).

[In General Formula (1), R ¹ is a hydrogen atom or a methyl group, A is a divalent linking group, R ² and R ³ are each independently a hydrocarbon group that may contain a hydrogen atom or a heteroatom. R ² and R ³ may be bonded to each other to form a ring structure. ] In the basic block copolymer, the following general formulas (2) to (4) are used so that nitrogen of at least some of the structural units represented by the general formula (1) is an ammonium ion. The pigment dispersion for a color filter according to claim 3, which is a salt-type block copolymer formed by binding one or more compounds selected from the group consisting of compounds represented by formula (I) to form a salt.

[In General Formula (2), R ^a is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; a vinyl group, a phenyl group or a benzyl group which may have a substituent; O—R ^e , where R ^e is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; a vinyl group, a phenyl group or a benzyl group which may have a substituent; or carbon number It represents a (meth) acryloyl group via 1 to 4 alkylene groups. ]

[In General Formula (3), R ^b , R ^{b ′,} and R ^{b ″} each independently represent a hydrogen atom; an acidic group or an ester group thereof; A chain, a branched chain or a cyclic alkyl group; a vinyl group which may have a substituent, a phenyl group or a benzyl group; or —O—R ^f , wherein R ^f is a carbon which may have a substituent, A linear, branched or cyclic alkyl group of 1 to 20; an optionally substituted vinyl group, phenyl group or benzyl group; or (meth) acryloyl via an alkylene group of 1 to 4 carbon atoms Represents a group, and X represents a chlorine atom, a bromine atom or an iodine atom.]

[In General Formula (4), R ^c and R ^d each independently have a hydrogen atom; a hydroxyl group; a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; and a substituent. , A vinyl group, a phenyl group or a benzyl group; or -O-R ^e , where R ^e is a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms; may have a substituent, A vinyl group, a phenyl group or a benzyl group; or a (meth) acryloyl group via an alkylene group having 1 to 4 carbon atoms. However, at least one of R ^c and R ^d contains a carbon atom. ]   5. The organic pigment according to claim 1, wherein the organic pigment is at least one organic pigment selected from the group consisting of an anthraquinone pigment, a diketopyrrolopyrrole pigment, an azo pigment, a quinophthalone pigment, a dioxazine pigment, and a phthalocyanine pigment. A pigment dispersion for a color filter according to claim 1.   A colored composition comprising the color filter pigment dispersion according to any one of claims 1 to 5, a polymerization initiator, and an alkali-soluble resin, wherein the colored composition contains calcium (Ca ) And iron (Fe) in a total mass of 120 ppm by mass or less with respect to the entire colored composition.   The color filter according to claim 6, wherein the total mass of magnesium (Mg), aluminum (Al), and chromium (Cr) contained in the colored composition is 135 ppm by mass or less with respect to the entire colored composition. Coloring composition.   A color filter obtained using the pigment dispersion for a color filter according to any one of claims 1 to 5.   A color filter obtained by using the coloring composition for a color filter according to claim 6 or 7.   A display device comprising the color filter according to claim 8.