JP2011153278A - Fine pigment particle dispersion, photocurable composition, and new compound used therefor - Google Patents

Abstract

（Ｒ^１及びＲ^２は、各々独立に、水素原子またはスルホン酸基で置換された有機基を表す。）
【選択図】なしDisclosed is a pigment fine particle dispersion and a photocurable composition, which are particularly suitable as a color material for a color filter, having a small particle size of a pigment fine particle, a sharp particle size distribution peak, and high dispersion stability. The novel compound used for is provided.
A pigment fine particle dispersion containing pigment fine particles and a compound represented by the following general formula (1).

(R ¹ and R ² each independently represents an organic group substituted with a hydrogen atom or a sulfonic acid group.)
[Selection figure] None

Description

  The present invention relates to a pigment fine particle dispersion and a photocurable composition particularly suitable for use as a color material such as a color filter, and a novel compound used therefor.

  The color filter is required to have high performance and high quality, and attempts have been made to improve the organic pigment used in its production. Specifically, there are demands for a pigment dispersion having excellent storage stability and a color filter coloring pixel portion using the coating film having excellent contrast. In order to respond to such needs, for example, researches to reduce the size of pigment particles to a range of 10 to 100 nm and to stabilize the dispersion are underway. As a result, there is a possibility that a new characteristic that could not be predicted in the past can be effectively drawn out by taking advantage of the effect that is manifested for the first time by the nanometer size. In addition to the above-described color filter applications, for example, paints, printing inks, electrophotographic toners, inkjet inks, and the like are being researched and developed. In particular, the above-described color filter and ink-jet ink are being worked on for higher performance using fine chemical technology, and the results are expected.

Here, regarding the method of dispersing the organic pigment, there are various milling methods (breakdown method) such as bead mill method and salt milling method, and liquid phase method. Patent Documents 1 and 2 disclose that pigment fine particles prepared by a breakdown method are used for ink or the like. Patent Document 1 specifically discloses a pigment derivative in which a group having a triazine residue is introduced into a pigment molecule, and this is applied to a dispersion of breakdown pigment particles to improve viscosity reduction and ink gloss. Propose to do. Patent Document 2 proposes to improve the lightness of red ink by using a pigment derivative having a sulfonic acid group introduced into the pigment molecule.
On the other hand, the liquid phase method is suitable for obtaining fine pigment particles. Specifically, a pigment solution obtained by dissolving a pigment in a good solvent (first solvent) and a poor solvent (second solvent) are mixed to form nano particles. There is a reprecipitation method in which particles are deposited. Recently, in order to improve desired performance, it has been proposed to use a predetermined dispersant or dispersion aid in the reprecipitation method (see Patent Documents 3 to 6).

JP 2007-186681 A JP 2000-160084 A International Publication No. WO2006 / 121016 Pamphlet JP 2004-43776 A JP 2009-84417 A US Patent Application Publication No. 2008/0308005

  The present invention is a pigment fine particle dispersion and a photocurable composition, which are particularly suitable as a color material for a color filter, having a small particle size of the pigment fine particles, a sharp particle size distribution peak, and high dispersion stability. It aims at provision of the novel compound used for this. Also provided is a pigment fine particle dispersion and a photocurable composition that can increase the contrast when a pixel of a color filter is formed using the same, and exhibit high luminance, and a novel compound used in the pigment fine particle dispersion. With the goal.

The above problems have been solved by the following means.
(1) A pigment fine particle dispersion comprising pigment fine particles and a compound represented by the following general formula (1).

(In General Formula (1), X ¹ and X ² each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic group. R ¹ and R ² Each independently represents a hydrogen atom or a group represented by the following general formula (2), and at least one of R ¹ and R ² is a group represented by the following general formula (2).

(In the formula, Y represents a divalent organic linking group containing a hetero atom. A represents an alkylene group, an arylene group, or a heteroarylene group that may have a substituent. M represents an integer of 1 to 8. To express.)
(2) The pigment fine particles are produced by mixing a solution obtained by dissolving a pigment in a good solvent and a medium that is compatible with the good solvent and becomes a poor solvent for the pigment. (1) The pigment fine particle dispersion according to (1).
(3) X ¹ and X ² are each independently a hydrogen atom, a chlorine atom, a phenyl group, a cyano group, or an alkyl group having 1 to 4 carbon atoms (1) or (2) The pigment fine particle dispersion described in 1.
(4) The pigment constituting the pigment fine particles is at least one selected from the group consisting of a diketopyrrolopyrrole pigment, a quinacridone pigment, an anthraquinone pigment, and an azo pigment (1) to (3) The pigment fine particle dispersion according to any one of the above.
(5) The pigment fine particle dispersion according to any one of (1) to (4), further comprising a dispersant having a polycaprolactone structure.
(6) It further contains a polymer compound containing at least one repeating unit selected from repeating units represented by any one of the following general formulas (I) and (II): (5) The pigment fine particle dispersion according to any one of (5).

(In the general formulas (I) and (II), R ^{21 to} R ²⁶ each independently represents a hydrogen atom or a monovalent organic group, and X ²¹ and X ²² each independently represent —CO—, —C ( ═O) O—, —CONH—, —OC (═O) —, or a phenylene group, L ²¹ and L ²² each independently represent a single bond or a divalent organic linking group, and A ²¹ And A ²² each independently represents a monovalent organic group, ma and na each independently represents an integer of 2 to 8, and p and q each independently represents an integer of 1 to 100.)
(7) The pigment fine particle dispersion according to any one of (1) to (6), which is a color material for a color filter.
(8) A photocurable composition comprising the dispersion according to any one of (1) to (7) and a polymerizable compound.
(9) A color filter having pixels formed by curing the photocurable composition according to (8).
(10) A compound represented by the following general formula (1).

(In General Formula (1), X ¹ and X ² each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic group. R ¹ and R ² Each independently represents a hydrogen atom or a group represented by the following general formula (2), and at least one of R ¹ and R ² is a group represented by the following general formula (2).

(In the formula, Y represents a divalent organic linking group containing a hetero atom. A represents an alkylene group, an arylene group, or a heteroarylene group that may have a substituent. M represents an integer of 1 to 8. To express.)

The pigment fine particle dispersion of the present invention and the photocurable composition using the same have a small particle size, a sharp particle size distribution peak, and good dispersion stability (time passes). However, it is particularly suitable as a color material for color filters. In addition, the color filter pixels formed using this have an excellent effect of high contrast and high brightness.
In addition, the compound represented by the general formula (1) of the present invention is useful as a crystal growth inhibitor for pigment compounds or as a dispersion aid in pigment dispersions regardless of the type of pigment used.

The pigment fine particle dispersion of the present invention contains pigment fine particles and a compound represented by the general formula (1). According to such a preferred embodiment of the present invention, since the compound represented by the general formula (1) has a specific pigment mother nucleus structure, the mother nucleus strongly adsorbs to the pigment molecule by a strong interaction. The compound of the present invention has a hetero atom in the linking group between one sulfonic acid group and the pigment mother nucleus in the molecule. Therefore, it is considered that the ability to adsorb to the pigment surface more strongly and to suppress aggregation and association of pigment particles is high. This makes it possible to achieve both extremely high contrast and high brightness when, for example, the dispersion is used as a color filter. Further, although there are unclear points about the mechanism of action, the compound represented by the above general formula (1) is a specific surface state of the build-up fine particles obtained by the reprecipitation method that cannot be obtained by crushing. It acts suitably, and the above effect is exhibited at a higher level by combining these.
[Compound represented by general formula (1)]

○ X ¹ , X ²
In the general formula (1), X ¹ and X ² each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic group.
In · X ¹ and X ^2, the halogen atom fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a chlorine atom is preferable.
In · X ¹ and X ^2, alkyl groups, 1 to 6, preferably the number of carbon atoms, more preferably 1 to 4 alkyl groups, linear, branched, it may be any of circular. Specific examples of the group include a methyl group, a butyl group, and a t-butyl group, and a methyl group is preferable. When the alkyl group has a substituent, examples of the substituent include a hydroxyl group, alkoxy, alkylcarbonyl, alkylcarbonyloxy, and an aromatic group.
In · X ¹ and X ^2, of the aromatic group include phenyl group, naphthyl group, biphenyl group and the like, it is preferably a phenyl group. When the aromatic group has a substituent, examples of the substituent include a hydroxyl group, alkoxy, alkylcarbonyl, alkylcarbonyloxy, and an aromatic group.
· X ¹ and X ² are preferably a hydrogen atom, a chlorine atom, a methyl group, t- butyl group, a phenyl group, more preferably a hydrogen atom, a chlorine atom. X ¹ and X ² may be the same or different, but are preferably the same group.

○ R ¹ , R ²
In General Formula (1), R ¹ and R ² are each independently a hydrogen atom or a substituent represented by General Formula (2) below. However, at least one of R ¹ and R ² is a substituent represented by the general formula (2).

-Y in the formula:
Y represents a divalent organic linking group containing a hetero atom. Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom, and among them, an oxygen atom and a nitrogen atom are preferable. The divalent organic linking group may be a divalent organic linking group composed of a hetero atom and a substituted or unsubstituted alkylene group or arylene group. As an alkylene group, a C1-C10 alkylene group is preferable. As the arylene group, a phenyl group and a naphthyl group are preferable. When the alkylene group or arylene group has a substituent, examples of the substituent include a hydroxy group and a halogen atom. Specifically, -O-, -S-, -C (= O)-, -OC (= O)-, -C (= O) O-, -NHC (= O)-, -C (= O) NH-, -NHC (= O) NH-, -NHC (= O) O-, -OC (= O) NH-, and further, -O-, -S-, -C (= O)-, -OC (= O)-, -C (= O) O-, -NHC (= O)-, -C (= O) NH-, -NHC (= Examples thereof include a heteroatom selected from O) NH-, -NHC (= O) O-, and -OC (= O) NH- or a partial structure containing a heteroatom.
The linking group Y is considered to function as a part of the pigment adsorption group as a pigment synergist (dispersant or dispersion aid).

A in the formula:
A represents an alkylene group, an arylene group, or a heteroarylene group which may have a substituent.
Alkylene: C 1-10 is preferable, and methylene, ethylene, propylene, isopropylene, butylene, isobutylene and the like can be mentioned.
A arylene: A phenyl group, a naphthyl group, and an anthracenyl group are mentioned.
A heteroarylene of A: pyridyl group, pyrimidyl group, triazyl group, phenylimidazole group, phenylthiazole group, pyrazolyl group, imidazole group, thiazole group, and the like.
A substituent that A may have: As an optional substituent, an alkyl group, an alkoxy group, a methoxy group, an alkoxycarbonyl group, an amide group, a halogen atom (a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), or A cyano group etc. are mentioned. Among these, a methyl group, a methoxy group, or unsubstituted (hydrogen) is preferable.
As A, a phenyl group, a naphthyl group, and a phenylimidazole group are preferable, and a phenyl group is particularly preferable.

・ M in the formula:
m represents an integer of 1 to 8, preferably 1 to 4, and particularly preferably m = 1 or 2.

  Specific examples of the compound represented by the general formula (1) are shown below, but the present invention is not construed as being limited thereto.

  In the pigment fine particle dispersion of the present invention, the content of the compound represented by the general formula (1) is not particularly limited, but is preferably 1 to 100 parts by mass with respect to 100 parts by mass of the pigment, and 10 to 50 More preferably, it is part by mass. By setting it to the above lower limit value or more, it is possible to stably disperse fine pigment particles having a large surface area, and by setting the upper limit value or less, it is possible to prevent a decrease in color value due to excessive addition of a pigment derivative. In the present invention, two or more compounds represented by the above general formula (1) may be used. For the method for synthesizing the compound represented by the general formula (1), the methods described in the Examples below can be referred to, and the compounds can be synthesized by appropriately applying the standard method based on the methods. In the present invention, the compound may be a salt of the compound itself, as well as a salt thereof when it has an acidic group or a basic group.

  The compound represented by the general formula (1) may be added to the dispersion of pigment fine particles at any stage, and may be added to a good solvent or a poor solvent in the reprecipitation method described below, Alternatively, it may be added after the precipitation of pigment fine particles or after concentration or redispersion. In the present invention, considering a non-aqueous dispersion for a color filter, a dispersant suitable as a photocurable composition for a color filter when the dispersion is concentrated or powdered and then redispersed. In addition, it is preferable to add as a dispersion aid.

  In the notation of a group in the present specification, the notation that does not indicate substitution and non-substitution is meant to include not only a substituent but also a substituent. For example, the expression “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

[Organic pigments]
The pigment fine particle dispersion of the present invention contains pigment fine particles together with the compound represented by the general formula (1).
The pigment is an organic pigment, and is not limited in hue. For example, a perylene pigment, a perinone pigment, a quinacridone pigment, a quinacridonequinone pigment, an anthraquinone pigment, an anthrone pigment, a benzimidazolone pigment, a disazo condensation pigment, Disazo pigment, azo pigment, indanthrone pigment, phthalocyanine pigment, triarylcarbonium pigment, dioxazine pigment, aminoanthraquinone pigment, diketopyrrolopyrrole pigment, thioindigo pigment, isoindoline pigment, isoindolinone pigment, pyranthrone pigment, or isoviola Nthrone pigment, or a mixture thereof. Among these, quinacridone pigments, anthraquinone pigments, benzimidazolone pigments, phthalocyanine pigments, azo pigments and dioxazine pigments are preferable, and diketopyrrolopyrrole pigments are more preferable.
In the present invention, the above organic pigments or solid solutions of organic pigments may be used in combination. Alternatively, a composite material combined with other compounds may be used.

  In the pigment fine particle dispersion of the present invention, the content of the pigment fine particles is not particularly limited. However, when considering the use as a color material for a color filter, the concentration contained in the pigment fine particle dispersion is 1 to 40% by mass. It is preferable that it is 5-20 mass%.

[Crushing method]
The pigment fine particles used in the present invention may be pigment fine particles prepared by a breakdown method such as a pulverization method. In that case, it can obtain by mixing various solvents, resin, varnish etc. if necessary, and disperse | distributing with a horizontal sand mill, a vertical sand mill, an annular bead mill, an attritor, etc. The specific polymer compound (specific polymer) and other pigment dispersants to be described later may be dispersed after mixing all components. First, the pigment and the specific polymer compound (specific polymer), etc. Alternatively, only the pigment or only the pigment and the pigment dispersant may be dispersed, and then another component may be added and dispersed again.
Also, before dispersing with a horizontal sand mill, vertical sand mill, annular bead mill, attritor, etc., pre-dispersion using a kneader mixer such as a kneader, 3-roll mill, solid dispersion with 2-roll mill, etc., or pigment A synergist having a basic group and / or a dispersant may be treated. Moreover, a disperser and a mixer such as a high speed mixer, a homomixer, a ball mill, a roll mill, a stone mill, and an ultrasonic disperser can be used.

[Reprecipitation method]
In the pigment fine particle dispersion of the present invention, the organic pigment particles to be contained therein include an organic pigment solution in which an organic pigment is dissolved in a good solvent (hereinafter sometimes referred to as a first solvent), and the good solvent. It is preferably produced by mixing with a solvent that is compatible with the organic pigment and that is a poor solvent (hereinafter sometimes referred to as a second solvent). Hereinafter, this method is sometimes referred to as “reprecipitation method”, and the resulting dispersion containing organic pigment particles is sometimes referred to as “pigment reprecipitation solution”. Further, the reprecipitation method in which the compound represented by the general formula (1) or the dispersant is co-dissolved in the organic pigment solution is distinguished from the reprecipitation method, particularly “coprecipitation method”. There are times.

○ Poor solvent First, the poor solvent for organic pigments will be explained. The poor solvent is not particularly limited as long as it is compatible with or uniformly mixed with a good solvent for dissolving the organic pigment. As a poor solvent, it is preferable that the solubility of an organic pigment is 0.02 mass% or less, and it is more preferable that it is 0.01 mass% or less. Although there is no particular lower limit to the solubility of the organic pigment in the poor solvent, 0.000001% by mass or more is practical in consideration of a commonly used organic pigment. This solubility may be a solubility in the presence of an acid or an alkali. In particular, in the case of a pigment species whose solubility changes remarkably depending on the hydrogen ion concentration (pH), an acid or an alkali may be appropriately mixed with a poor solvent and used. preferable.
The amount of the good solvent dissolved in the poor solvent is preferably 30% by mass or more, and more preferably 50% by mass or more. There is no particular upper limit to the amount of good solvent dissolved in the poor solvent, but it is practical to mix them in an arbitrary ratio.
Examples of the poor solvent include aqueous solvents (for example, water, hydrochloric acid, sodium hydroxide aqueous solution), alcohol compound solvents, ketone compound solvents, ether compound solvents, aromatic compound solvents, carbon disulfide solvents, aliphatic compound solvents, nitrile compounds. Solvents, halogen compound solvents, ester compound solvents, ionic liquids, mixed solvents thereof and the like are included, and aqueous solvents, alcohol compound solvents, ketone compound solvents, ether compound solvents, ester compound solvents, or a mixture thereof are preferable, and aqueous solvents A solvent, an alcohol compound solvent or an ester compound solvent is more preferred.
Examples of the alcohol compound solvent include methanol, ethanol, isopropyl alcohol, n-propyl alcohol, 1-methoxy-2-propanol and the like. Examples of the ketone compound solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. Examples of the ether compound solvent include dimethyl ether, diethyl ether, tetrahydrofuran, and the like. Examples of the aromatic compound solvent include benzene and toluene. Examples of the aliphatic compound solvent include hexane. Examples of the nitrile compound solvent include acetonitrile. Examples of the halogen compound solvent include dichloromethane and trichloroethylene. Examples of the ester compound solvent include ethyl acetate, ethyl lactate, propylene glycol monomethyl ether acetate (MMPGAc), and the like. The ionic liquids, for example, 1-butyl-3-methylimidazolium and PF ₆ ^-, etc. and salts thereof.
The poor solvent may be used by mixing a plurality of solvents, and depending on the system, it may be used by mixing a good solvent. However, in this case, it is necessary to mix within a range that does not hinder the precipitation, refinement, and crystallization of the pigment particles.

○ Good solvent Next, a good solvent for dissolving the organic pigment will be described. The good solvent is not particularly limited as long as it can dissolve the pigment to be used and is compatible with or uniformly mixed with the poor solvent. The solubility of the organic pigment in the good solvent is preferably 0.2% by mass or more, and more preferably 0.5% by mass or more. Although there is no particular upper limit to the solubility, it is practical that the solubility is 50% by mass or less in consideration of a commonly used organic pigment. This solubility may be the solubility when dissolved in the presence of an acid or alkali. A preferred range of solubility or compatibility between the poor solvent and the good solvent is as described above.
Examples of the good solvent include an aqueous solvent (for example, water or hydrochloric acid, an aqueous sodium hydroxide solution), an alcohol compound solvent, an amide compound solvent, a ketone compound solvent, an ether compound solvent, an aromatic compound solvent, a carbon disulfide solvent, and a fat. Group compound solvents, nitrile compound solvents, sulfoxide compound solvents, halogen compound solvents, ester compound solvents, ionic liquids, mixed solvents thereof, and the like, aqueous solvents, alcohol compound solvents, ketone compound solvents, ether compound solvents, sulfoxide compounds Solvents, ester compound solvents, amide compound solvents, or mixtures thereof are preferred, aqueous solvents, alcohol compound solvents, ester compound solvents, sulfoxide compound solvents or amide compound solvents are preferred, aqueous solvents, sulfoxide compound solvents or amide compounds. More preferably medium, sulfoxide compound solvent or the amide compound solvent is particularly preferred.
Examples of the sulfoxide compound solvent include dimethyl sulfoxide, diethyl sulfoxide, hexamethylene sulfoxide, sulfolane and the like. Examples of the amide compound solvent include N, N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 2-pyrrolidinone, ε-caprolactam, formamide, N -Methylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropanamide, hexamethylphosphoric triamide and the like.
Further, the concentration of the organic pigment solution in which the organic pigment is dissolved in the good solvent is preferably a saturated concentration of the organic pigment with respect to the good solvent or a range of about 1/100 of this in the dissolving conditions. There are no particular limitations on the conditions for preparing the organic pigment solution, and a range from normal pressure to subcritical and supercritical conditions can be selected. The temperature at normal pressure is preferably −10 to 150 ° C., more preferably −5 to 130 ° C., and particularly preferably 0 to 100 ° C.

  In the present invention, the organic pigment can be dissolved in a good solvent acidic or alkaline. In general, in the case of a pigment having an alkaline and dissociable group in the molecule, alkali is used, and when there is no alkaline and dissociable group and there are many nitrogen atoms in the molecule that are prone to add protons, acidity is used. For example, quinacridone, diketopyrrolopyrrole, disazo condensation compound pigments are alkaline, and phthalocyanine compound pigments are acidic.

  Bases used for alkaline dissolution are inorganic bases such as lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, or barium hydroxide, or trialkylamine, diazabicycloundecene (DBU), An organic base such as a metal alkoxide is preferable, but an organic base is preferable. The amount of the base used is an amount capable of uniformly dissolving the pigment, and is not particularly limited. However, in the case of an inorganic base, it is preferably 1.0 to 30 molar equivalents, more preferably 1 with respect to the organic pigment. 0.0 to 25 molar equivalents, more preferably 1.0 to 20 molar equivalents. In the case of an organic base, it is preferably 1.0 to 100 molar equivalents, more preferably 1.0 to 50 molar equivalents, and still more preferably 1.0 to 20 molar equivalents relative to the organic pigment.

  The acid used for the acid dissolution is an inorganic acid such as sulfuric acid, hydrochloric acid, or phosphoric acid, or an organic acid such as acetic acid, trifluoroacetic acid, oxalic acid, methanesulfonic acid, or trifluoromethanesulfonic acid, but preferably It is an inorganic acid. Particularly preferred is sulfuric acid. The amount of the acid used is an amount capable of uniformly dissolving the organic pigment, and is not particularly limited, but is often used in an excessive amount as compared with the base. Regardless of the inorganic acid or organic acid, it is preferably 3 to 500 molar equivalents, more preferably 10 to 500 molar equivalents, and further preferably 30 to 200 molar equivalents with respect to the organic pigment.

  When mixing alkali or acid with an organic solvent and using it as a good solvent for organic pigments, a solvent having high solubility in some alkali or acid such as water or lower alcohol in order to completely dissolve the alkali or acid Can be added to the organic solvent. The amount of water or lower alcohol is preferably 50% by mass or less, more preferably 30% by mass or less, based on the total amount of the organic pigment solution. Specifically, water, methanol, ethanol, n-propanol, isopropanol, butyl alcohol, or the like can be used.

○ Mixing conditions There are no particular restrictions on the use conditions of the poor solvent when preparing the organic particles, that is, when the organic particles are deposited and formed, and a range from normal pressure to subcritical and supercritical conditions can be selected. The temperature at normal pressure is preferably −30 to 100 ° C., more preferably −10 to 60 ° C., and particularly preferably 0 to 30 ° C.
The mixing ratio of the pigment solution and the poor solvent (ratio of good solvent / poor solvent in the reprecipitation liquid) is preferably 1/50 to 1/1, more preferably 1/40 to 1/1, and more preferably 1/10 to 10 in volume ratio. 1/1 is particularly preferred. This may be the same as or different from the volume flow ratio of the pigment solution and the poor solvent in the flow reactor. For example, when the mixing ratio is 1/2, the following method can be taken as a specific example.
(I) The volume flow ratio between the good solvent and the poor solvent is halved. (Ii) The solvent obtained by mixing the good solvent in advance with the ratio of (good solvent / poor solvent volume ratio) = (¼). Using A, the volume flow ratio of the pigment solution and the solvent A is set to 1/5. In this case, the amount obtained by adding the good solvent in the pigment solution and the good solvent in the solvent A is 1 + 1 = 2, while the amount of the poor solvent in the solvent A is 4. The mixing ratio is 1/2. The pigment concentration in the pigment reprecipitation liquid is not particularly limited as long as the pigment particles can be generated, but the pigment particles should be in the range of 10 to 40,000 mg per 1000 ml of the reprecipitation liquid. Is preferable, more preferably in the range of 20 to 30000 mg, and particularly preferably in the range of 40 to 25000 mg.

  In the present invention, it is preferable to rapidly mix the pigment solution and the poor solvent, and a means for promoting mixing is particularly preferable in this part. As one of the methods, mixing is promoted by turbulent mixing field, for example, a method of causing a high-speed fluid to flow in a counterflow state and colliding in a narrow space can be considered. However, the mixing mode is not limited to turbulent flow control. For example, as shown in Japanese Patent Laid-Open No. 2006-104448, fluids are brought into contact with each other in a laminar flow state at the intersection of Y-shaped flow paths. A method of mixing by molecular diffusion is also conceivable.

In the present invention, whether the fluid flow state is turbulent or laminar is determined by the tube Reynolds number. That is, the pipe representative length (referred to as a representative diameter in the present invention) is D [m], the linear flow velocity of the flowing liquid is u [m / s] (definition will be described later), and the density and viscosity of the liquid are ρ [kg], respectively. / M ³ ], η [Pa · s], the tube Reynolds number Re [−] is Re = Duρ / η
Defined by In the present invention, it is assumed that a state where Re is 1000 or more is turbulent, a state where 100 or more and less than 1000 is a transition region, and a state where Re is less than 100 is laminar flow.
The representative length D of the above equation is a physical property of the tube that has the most influence on the flow in the tube. In the case of a cylindrical tube, its diameter is defined. Otherwise, it is defined by the following equation.
D = 4A / p
Here, A [m ² ] is the cross-sectional area of the flow path, and p [m] is the length (immersion side length) of the portion where the fluid contacts the wall in the flow path.
Using this D, the aforementioned linear flow velocity u is defined as follows.
u = Q / {(D / 2) ² × π}
Here, Q is the volume flow rate [m ³ ] of the fluid flowing through the flow path that defines the linear flow velocity. The representative diameter when the diameter or cross-sectional shape is changed in the middle of the flow path depends on the cross-sectional shape after the change. The linear flow velocity and the Reynolds number may be obtained according to the representative diameter.
In the present invention, the flow state of the mixing field is important, but it is difficult to appropriately measure the state of the mixing field. Therefore, when both of the following two conditions are satisfied, the state of the mixing field is controlled by turbulent flow. Estimated.
(I) From the tube Reynolds number Re immediately before mixing of each fluid to be mixed, at least the flow state in one flow path connected to the mixing field is regarded as turbulent flow.
(Ii) From the tube Reynolds number Re immediately after mixing of the fluid after mixing, the flow state immediately after mixing is regarded as turbulent flow.

  In the above particle formation step, it is preferable to adjust the representative diameter, flow rate, etc. of the reactor so that the average particle diameter of the precipitated pigment particles falls within a desired range. In the reactor used in this embodiment, the flow rate of each flow path can be made relatively large, and the mixing state of the mixing field created at this time is considered suitable for pigment particle formation. The linear flow rates of the pigment solution and the poor solvent in each raw material supply channel of the reactor are preferably 1 to 30 m / s.

[Dispersant used for reprecipitation]
In the present invention, when the pigment is dissolved in a good solvent, both the pigment dispersant and the pigment derivative may be dissolved together. In the organic solvent, a polymer dispersant is preferably used as the dispersant from the viewpoint of ensuring dispersibility by a repulsive action utilizing the entropy repulsive force of the molecular chain. The particle surface can also be modified by using pigment derivatives, and in particular, the interaction force with other dispersants can be improved, or the solubility and crystal form of the particles can be controlled. Pigment derivatives are also preferably used.

  As a dispersant that can be used, for example, a low molecular or high molecular dispersant of anionic, cationic, amphoteric, nonionic or pigment derivative can be used. The molecular weight of the polymer dispersant can be used without limitation as long as it can be uniformly dissolved in a solution, but preferably has a molecular weight of 1,000 to 2,000,000, and 5,000 to 1,000,000. 000 is more preferable, 10,000 to 500,000 is more preferable, and 10,000 to 100,000 is particularly preferable. Examples of the polymer dispersant include those exemplified in the dispersants A and B described later.

  Examples of anionic dispersants (anionic surfactants) include N-acyl-N-alkyl taurine salts, fatty acid salts, alkyl sulfate esters, alkyl benzene sulfonates, alkyl naphthalene sulfonates, dialkyl sulfosuccinates, alkyl phosphorus Examples include acid ester salts, naphthalene sulfonic acid formalin condensate, polyoxyethylene alkyl sulfate ester salts, and the like. These anionic dispersants can be used alone or in combination of two or more.

  Cationic dispersants (cationic surfactants) include quaternary ammonium salts, alkoxylated polyamines, aliphatic amine polyglycol ethers, aliphatic amines, diamines and polyamines derived from aliphatic amines and fatty alcohols, fatty acids And imidazolines derived from these and salts of these cationic substances. These cationic dispersants can be used alone or in combination of two or more.

  The amphoteric dispersant is a dispersant having both an anion group part in the molecule of the anionic dispersant and a cationic group part in the molecule of the cationic dispersant. Nonionic dispersants (nonionic surfactants) include polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, Examples thereof include glycerin fatty acid esters. These nonionic dispersants can be used alone or in combination of two or more.

  A pigment derivative type dispersant is derived from an organic pigment as a parent substance, and is obtained by a pigmentation reaction of a pigment derivative type dispersant produced by chemically modifying the parent structure or a chemically modified pigment precursor. Defined as a pigment derivative type dispersant. For example, a sugar-containing pigment derivative-type dispersant, a piperidyl-containing pigment derivative-type dispersant, a naphthalene or perylene-derived pigment derivative-type dispersant, a pigment derivative-type dispersant having a functional group linked to a pigment parent structure via a methylene group, Pigment parent structure chemically modified with polymer, pigment derivative type dispersant having sulfonic acid group, pigment derivative type dispersant having sulfonamide group, pigment derivative type dispersant having ether group, carboxylic acid group, carboxylic acid ester And pigment derivative type dispersants having a group or a carboxamide group.

[Pigment fine particles]
Regarding the particle size of fine particles, there is a method of expressing the average size of the population by quantifying by a measurement method, but it is often used that the mode diameter indicating the maximum value of the distribution, the median value of the integral distribution curve There are corresponding median diameters, various average diameters (number average, length average, area average, mass average, volume average, etc.), etc. In the present invention, unless otherwise specified, the average particle diameter is the number average diameter. Say. The average particle size of the fine particles (primary particles) in the dispersion of the present invention is preferably 100 nm or less, more preferably 75 nm or less, and particularly preferably 50 nm or less. The fine particles in the dispersion of the present invention may be a single crystal, a polycrystal or an aggregate of that size, or may contain these.

  In the present invention, the ratio (Mv / Mn) of the volume average particle diameter (Mv) to the number average particle diameter (Mn) is used as an index representing the uniformity (monodispersity) of the particles, unless otherwise specified. The monodispersity of the organic nanoparticles (primary particles) of the present invention (in the present invention, monodispersity refers to the degree of uniform particle size), that is, Mv / Mn is 1.0 to 2.0. It is preferably 1.0 to 1.8, more preferably 1.0 to 1.5.

  Examples of the method for measuring the particle size of the organic particles include microscopy, mass method, light scattering method, light blocking method, electrical resistance method, acoustic method, and dynamic light scattering method. Particularly preferred. Examples of the microscope used for the microscopy include a scanning electron microscope and a transmission electron microscope. Examples of the particle measuring apparatus based on the dynamic light scattering method include Nikkiso's Nanotrac UPA-EX150, Otsuka Electronics' dynamic light scattering photometer DLS-7000 series (both are trade names), and the like. In the present invention, the value relating to the particle diameter means a value measured by the method employed in the examples unless otherwise specified.

  The fine particles in the dispersion of the present invention preferably have a crystallinity of 65% or more in the dispersion medium, but this crystallinity is preferably 80 to 100%, and 90 to 100%. More preferably. The crystallite size of the fine particles in the dispersion of the present invention is not particularly limited, but is preferably 20 to 500 angstroms, and more preferably 20 to 200 angstroms. In the present invention, the crystallinity and crystallite diameter are values measured as follows unless otherwise specified.

(Evaluation of crystallinity)
As a typical index of crystallinity, the method of obtaining α crystallinity is that the peak intensity I _α and β-type crystal at 28 ± 0.5 °, which is a characteristic Bragg angle (2θ) of _α- type crystal. calculated by the following formula from the peak intensity I _beta characteristic 27 ° the Bragg angle (2 [Theta]) of.
(Α crystallinity) = (I _α ) / (I _α + I _β )
The peak intensity I _α of 28 ± 0.5 ° which is the characteristic Bragg angle (2θ) of the _α- type crystal and the peak intensity I _β of 27 ° which is the characteristic Bragg angle (2θ) of the β-type crystal are as follows: So ask. The background is removed from the diffraction pattern obtained by the X-ray diffraction measurement as follows. A straight line in contact with the vicinity of 23 ° on the low angle side and the vicinity of 30 ° on the high angle side of the Bragg angle of the α-type crystal was drawn, and this straight line was removed as a background. The peak intensities I _α and I _β are obtained from the diffraction pattern from which the background is removed, and the α crystallinity is calculated by the above formula.

(Measurement of crystallite diameter)
X-ray diffraction analysis using Cu-Kα1 line is performed. Thereafter, in the range of 2θ = 4 deg to 70 deg, the half width of the peak showing the maximum intensity or the peak showing a sufficiently large intensity that can be separated from the adjacent peak is measured, and the crystallite diameter is calculated according to the following Serrer's formula. Calculate:
D = K × λ / (β × cos θ): Scherrer equation [D: crystallite diameter (Å, crystallite size), λ: measured X-ray wavelength (Å), β: diffraction line due to crystal size Spread (radian), θ: Bragg angle of diffraction line (radian), K: constant (differing between β and D constants)]
In general, it is known that K = 0.9 when a half width β1 / 2 is used for β. Also, since the wavelength of the Cu-Kα1 line is 1.54050 mm, the crystallite diameter D in the present invention is calculated based on the following formula:
D = 0.9 × 1.54050 / (β1 / 2 × cos θ)
Here, when the peak of the spectrum obtained by the measurement is broad and the half width of the peak cannot be determined, it is estimated that the crystallite diameter is less than 20 mm or is in an amorphous state (amorphous).

[Concentration and redispersion]
○ Concentration of dispersion The process of removing the solvent from the mixed liquid after the organic pigment fine particles are deposited is not particularly limited. For example, a method of filtering with a filter or the like, a method of precipitating and concentrating the organic pigment fine particles by centrifugation. Etc. As the filter filtration device, for example, a device such as reduced pressure or pressure filtration can be used. Examples of preferable filters include filter paper, nanofilters, and ultrafilters. Any device may be used as the centrifuge as long as the water-insoluble compound fine particles can be precipitated. For example, in addition to a general-purpose device, a device having a skimming function (a function of sucking a supernatant layer during rotation and discharging it out of the system), a continuous centrifuge that continuously discharges solid matter, and the like can be given. Centrifugation conditions are preferably 50 to 10000, more preferably 100 to 8000, and particularly preferably 150 to 6000 in terms of centrifugal force (a value representing how many times the gravitational acceleration is applied). Although the temperature at the time of centrifugation is based on the solvent seed | species of a dispersion liquid, -10-80 degreeC is preferable, -5-70 degreeC is more preferable, 0-60 degreeC is especially preferable. In addition, as a solvent removal step, a method of concentrating the solvent by sublimation by vacuum freeze-drying, a method of drying and concentrating the solvent by heating or decompression, a method combining them, or the like can also be used.

Re-dispersion Organic pigment fine particles can be used, for example, in a dispersed state in a vehicle. The vehicle refers to a portion of a medium in which an organic pigment is dispersed when in a liquid state, and is a portion that is liquid and binds to the water-insoluble compound to harden a coating film (binder). And a component (organic solvent) for dissolving and diluting it. In the present invention, the polymer compound used for fine particle formation and / or the organic pigment dispersant used for redispersion are collectively referred to as a binder.

  The fine particle concentration of the dispersion of fine particles after redispersion is appropriately determined according to the purpose, but preferably the fine particles are 2 to 30% by mass, and 4 to 20% by mass with respect to the total amount of the dispersion. It is more preferable that the content is 5 to 15% by mass. In the case of dispersing in the vehicle as described above, the amount of the binder and the dissolved dilution component is appropriately determined depending on the type of the water-insoluble compound, but the binder may be 1 to 30% by mass with respect to the total amount of the dispersion. Preferably, it is 3-20 mass%, More preferably, it is 5-15 mass%. It is preferable that a dissolution dilution component is 5-80 mass%, and it is more preferable that it is 10-70 mass%.

  The organic pigment fine particles can be re-dispersed in the same organic solvent used in the poor solvent liquid, and the organic pigment fine particles can be dispersed in the same organic solvent as the poor solvent without adding another dispersant. It is preferable that the aggregated state is spontaneously solved and dispersed in the medium, and this property is referred to as “can self-disperse” or “have self-dispersibility”. However, in order to further improve the redispersibility in the present invention, a pigment dispersant or the like may be added during redispersion of the fine particles. From this point of view, aggregates that are difficult to redisperse may be distinguished from soft agglomerates that can be redispersed or loosely reaggregated (flocculate). As for the aggregation form and the like of these fine particles, reference can be made to Journal of the Imaging Society of Japan, “Organic Pigment Refinement and Dispersion Technology”, Takashi Deno, Vol. 45, No. 5, 2006, pages 12-21.

  As a method for redispersing fine particles in such a soft aggregated state (agglomerate), for example, a dispersion method using ultrasonic waves or a method of applying physical energy can be used. The ultrasonic irradiation device used preferably has a function capable of applying an ultrasonic wave of 10 kHz or higher, and examples thereof include an ultrasonic homogenizer and an ultrasonic cleaner. When the liquid temperature rises during ultrasonic irradiation, thermal aggregation of the nanoparticles occurs, so the liquid temperature is preferably 1 to 100 ° C, more preferably 5 to 60 ° C. The temperature control method can be performed by controlling the dispersion temperature, controlling the temperature of the temperature adjusting layer that controls the temperature of the dispersion, or the like. There are no particular limitations on the disperser used when dispersing the pigment nanoparticles by applying physical energy, for example, dispersers such as kneaders, roll mills, atriders, super mills, dissolvers, homomixers, and sand mills. Can be mentioned. Further, a high-pressure dispersion method and a dispersion method using fine particle beads are also preferable.

[Polymer dispersant]
In the present invention, it is preferable to remove the aqueous solvent content of the dispersion prepared by the reprecipitation method as described above. It is preferable not to have a drying step after the step of removing the aqueous phase. At this time, for the purpose of further improving the dispersibility of the pigment, a dispersant such as a specific pigment dispersant or surfactant may be added as long as the effects of the present invention are not impaired. The dispersant used here may be used in the reprecipitation method described above, and may coexist at the time of precipitation of pigment fine particles, for example. In the present invention, polymer compounds are mainly exemplified as the following dispersants. However, in the present invention, when it is referred to as molecular weight, it means mass average molecular weight unless otherwise specified, and molecular weight and dispersity are values measured by the following measuring methods.

[Method for measuring molecular weight and dispersity of polymer compound]
The molecular weight and degree of dispersion are measured using GPC (gel filtration chromatography) unless otherwise specified. The gel packed in the column used in the GPC method is preferably a gel having an aromatic compound as a repeating unit, and examples thereof include a gel made of a styrene-divinylbenzene copolymer. It is preferable to use 2 to 6 columns connected together. Examples of the solvent used include ether solvents such as tetrahydrofuran and amide solvents such as N-methylpyrrolidinone, but ether solvents such as tetrahydrofuran are preferred. The measurement is preferably performed at a solvent flow rate in the range of 0.1 to 2 mL / min, and most preferably in the range of 0.5 to 1.5 mL / min. By performing the measurement within this range, the apparatus is not loaded and the measurement can be performed more efficiently. The measurement temperature is preferably 10 to 50 ° C, most preferably 20 to 40 ° C.

Specific conditions for molecular weight measurement are shown below.
Apparatus: HLC-8220GPC (manufactured by Tosoh Corporation)
Detector: Differential refractometer (RI detector)
Pre-column: TSKGUARDCOLUMN MP (XL)
6mm x 40mm (manufactured by Tosoh Corporation)
Sample side column: The following two columns are directly connected (all manufactured by Tosoh Corporation)
・ TSK-GEL Multipore-HXL-M 7.8 mm x 300 mm
Reference side column: Same as sample side column Temperature chamber temperature: 40 ° C
Moving bed: tetrahydrofuran Sample-side moving bed flow rate: 1.0 mL / min Reference-side moving bed flow rate: 0.3 mL / min Sample concentration: 0.1% by weight
Sample injection volume: 100 μL
Data collection time: 16 minutes to 46 minutes after sample injection Sampling pitch: 300 msec

○ Dispersant A
In the present invention, a dispersant such as a pigment dispersant or a surfactant may be added for the purpose of further improving the dispersibility of the processed pigment. Dispersants (pigment dispersants) include polymer dispersants [for example, polyamidoamines and salts thereof, polycarboxylic acids and salts thereof, high molecular weight unsaturated acid esters, modified polyurethanes, modified polyesters, modified poly (meth) acrylates, (Meth) acrylic copolymer, naphthalenesulfonic acid formalin condensate], polyoxyethylene alkyl phosphate ester, polyoxyethylene alkyl amine, alkanol amine, pigment derivative and the like. The polymer dispersant can be further classified into a linear polymer, a terminal-modified polymer, a graft polymer, and a block polymer according to the structure.

  The polymer dispersant is adsorbed on the surface of the pigment and acts to prevent reaggregation. Therefore, a terminal-modified polymer, a graft polymer and a block polymer having an anchor site to the pigment surface can be mentioned as preferred structures. On the other hand, the pigment derivative has an effect of promoting the adsorption of the polymer dispersant by modifying the pigment surface. The polymer dispersant acts to adsorb on the surface of the pigment and prevent reaggregation in the dispersion step. For this reason, a block polymer, a graft polymer, and a terminal-modified polymer having an anchor site to the pigment surface can be cited as preferred structures. On the other hand, the pigment derivative has an effect of promoting the adsorption of the polymer dispersant by modifying the pigment surface.

-Graft type polymer The graft type polymer is not particularly limited, but is a compound obtained by reacting a polyalkyleneimine and a polyester compound described in JP-A-54-37082, JP-A-61-174939, etc. Preferable examples include a compound in which the amino group of the side chain of polyallylamine described in JP-A-9-169821 is modified with polyester, a polyester polyol-added polyurethane described in JP-A-60-166318, and the like. As described in Kaihei 9-171253, Macromonomer Chemistry and Industry (IPC Publishing Department, 1989), etc., a graft-type polymer having a polymerizable oligomer (hereinafter referred to as a macromonomer) as a copolymerization component. Can also be mentioned. Moreover, the graft | grafting type | mold polymer which has an organic pigment | dye part of Unexamined-Japanese-Patent No. 2003-238837 is preferable at the point of adsorb | sucking to a pigment and giving favorable dispersibility. Suitable examples of the branch of the graft polymer include polystyrene, polyethylene oxide, polypropylene oxide, poly (meth) acrylic acid ester, polycaprolactone, and the like, but a graft polymer having a polycaprolactone chain is more preferable. Commercially available products of the graft-type polymer include Solsperse 24000, 28000, 32000, 38500, 39000, 35000 (above Lubrizol), Disperbyk-161, -171, -174 (above BYK). Chemie), etc. [all trade names].

Terminal-modified polymer Examples of the terminal-modified polymer are described in JP-A-9-77994, JP-A-2002-273191, JP-A-2007-277514, JP-A-2007-140487, and the like. And a polymer having a functional group at the terminal of the polymer.

-Block-type polymer Although it does not specifically limit as a block-type polymer, The block-type polymer which consists of a pigment adsorption block and a block which is not adsorbed to a pigment is mentioned. Although it does not restrict | limit especially as a monomer which comprises a pigment adsorption block, For example, the monomer which has a functional group which can adsorb | suck to a pigment is mentioned. Specific examples include a monomer having an organic dye structure or a heterocyclic structure, a monomer having an acidic group, and a monomer having a basic nitrogen atom. Examples of the monomer having an organic dye structure or a heterocyclic structure include organic dye skeletons and maleimide derivatives described in JP-A No. 2003-238837. Commercially available products can be used as the block polymer. As specific examples, Disperbyk-2000, -2001 (above BYK Chemie), EFKA4330, 4340 (above EFKA), etc. [all trade names] can be mentioned.

  The amount of the dispersant A used in the dispersion is not particularly limited, but is preferably 10 to 400 parts by weight with respect to 100 parts by weight of the pigment, for example, considering use as a color material with the color filter. More preferably, it is -200 mass parts.

○ Dispersant B
In the present invention, a polymer compound containing at least one repeating unit selected from repeating units represented by any one of the following general formulas (I) and (II) (hereinafter referred to as “dispersing agent B”). It is preferable to contain a certain).

In the general formulas (I) and (II), R ^{21 to} R ²⁶ each independently represent a hydrogen atom or a monovalent organic group, and X ²¹ and X ²² each independently represent —CO—, -C (= O) O-, -CONH-, -OC (= O)-, or a phenylene group, L ²¹ and L ²² each independently represent a single bond or a divalent organic linking group. , A ²¹ and A ²² each independently represents a monovalent organic group, ma and na each independently represent an integer of 2 to 8, and p and q each independently represents 1 to 100. Represents an integer.

R ^{21 to} R ²⁶ each independently represents a hydrogen atom or a monovalent organic group. As the monovalent organic group, a substituted or unsubstituted alkyl group is preferable. As an alkyl group, a C1-C12 alkyl group is preferable, a C1-C8 alkyl group is more preferable, and a C1-C4 alkyl group is especially preferable. When the alkyl group has a substituent, examples of the substituent include a hydroxy group, an alkoxy group (preferably having 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms), a methoxy group, an ethoxy group, Examples include a cyclohexyloxy group. Specific examples of preferred alkyl groups include methyl, ethyl, propyl, n-butyl, i-butyl, t-butyl, n-hexyl, cyclohexyl, 2-hydroxyethyl, A 3-hydroxypropyl group, a 2-hydroxypropyl group, and a 2-methoxyethyl group are exemplified. R ²¹ , R ²² , R ²⁴ , and R ²⁵ are preferably hydrogen atoms, and R ²³ and R ²⁶ are most preferably a hydrogen atom or a methyl group from the viewpoint of adsorption efficiency on the pigment surface.

X ²¹ and X ²² each independently represent —CO—, —C (═O) O—, —CONH—, —OC (═O) —, or a phenylene group. Among them, —C (═O) O—, —CONH—, and a phenylene group are preferable from the viewpoint of adsorptivity to the pigment, and —C (═O) O— is most preferable.

L ²¹ and L ²² each independently represent a single bond or a divalent organic linking group. The divalent organic linking group is preferably a substituted or unsubstituted alkylene group or a divalent organic linking group comprising the alkylene group and a hetero atom or a partial structure containing a hetero atom. Here, the alkylene group is preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 8 carbon atoms, and particularly preferably an alkylene group having 1 to 4 carbon atoms. In addition, examples of the hetero atom in the partial structure containing a hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom, and among them, an oxygen atom and a nitrogen atom are preferable. Specific examples of preferable alkylene groups include a methylene group, an ethylene group, a propylene group, a trimethylene group, and a tetramethylene group. When the alkylene group has a substituent, examples of the substituent include a hydroxy group. The divalent organic linking group includes a heteroatom or a heteroatom selected from —C (═O) —, —OC (═O) —, and —NHC (═O) — at the end of the above alkylene group. A compound having a partial structure and linked to an adjacent oxygen atom via the heteroatom or a partial structure containing a heteroatom is preferable from the viewpoint of adsorptivity to the pigment. Here, the adjacent oxygen atom means an oxygen atom that is bonded to L ²¹ in the general formula (I) and L ²² in the general formula (II) on the side chain end side.

As A ²¹ and A ²² , from the viewpoint of dispersion stability and developability, a straight chain having 1 to 20 carbon atoms, a branched chain having 3 to 20 carbon atoms, and a carbon atom having 5 to 20 carbon atoms. A group selected from cyclic alkyl groups is preferable, and is selected from linear groups having 4 to 15 carbon atoms, branched chains having 4 to 15 carbon atoms, and cyclic alkyl groups having 6 to 10 carbon atoms. A group is more preferable, and a group selected from a linear alkyl group having 6 to 10 carbon atoms and a branched alkyl group having 6 to 12 carbon atoms is more preferable.

  ma and na each independently represents an integer of 2 to 8. In view of dispersion stability and developability, 4 to 6 is preferable, and 5 is particularly preferable.

  p and q each independently represent an integer of 1 to 100. Two or more different p and different q may be mixed. p and q are preferably 5 to 60, more preferably 5 to 40, and still more preferably 5 to 20 from the viewpoints of dispersion stability and developability.

  The dispersant B in this embodiment is preferably one containing a repeating unit represented by the general formula (I) from the viewpoint of dispersion stability.

  Moreover, as a repeating unit represented by general formula (I), it is more preferable that it is a repeating unit represented by the following general formula (I) -2.

In the general formula (I) -2, R ^{21 to} R ²³ each independently represents a hydrogen atom or a monovalent organic group, La represents an alkylene group having 2 to 10 carbon atoms, and Lb represents —C (═O) — or —NHC (═O) —, A ²¹ represents a monovalent organic group, ma represents an integer of 2 to 8, and p represents an integer of 1 to 100. Represents.

  The repeating unit represented by the general formula (I), (II), or (I) -2 is a simple unit represented by the following general formula (i), (ii), or (i) -2, respectively. The polymer is introduced as a repeating unit of the polymer compound by polymerization or copolymerization.

In the general formulas (i), (ii), and (i) -2, R ^{21 to} R ²⁶ each independently represent a hydrogen atom or a monovalent organic group, and X ²¹ and X ²² each represent Independently represents —CO—, —C (═O) O—, —CONH—, —OC (═O) —, or a phenylene group, and L ²¹ and L ²² each independently represents a single bond or 2 A valent organic linking group, La represents an alkylene group having 2 to 10 carbon atoms, Lb represents —C (═O) —, or —NHC (═O) —, and A ²¹ and A ²² represent Each independently represents a monovalent organic group, each of ma and na independently represents an integer of 2 to 8, and each of p and q independently represents an integer of 1 to 100.

  Below, the preferable specific example [monomer (A-1)-(A-23)] of the monomer represented by general formula (i), (ii), or (i) -2 is given to the following. However, the present invention is not limited to these.

  The dispersant B in this embodiment is sufficient if it contains at least one type of repeating unit selected from the repeating units represented by any one of the general formulas (I) and (II). There may be two or more kinds.

  In the dispersant B, the content of the repeating unit represented by any one of the general formulas (I) and (II) is not particularly limited, but the total repeating unit contained in the polymer is 100% by mass. In this case, the repeating unit represented by any one of the general formulas (I) and (II) is preferably contained in an amount of 5% by mass or more, more preferably 50% by mass, and 50% by mass to 80% by mass. It is more preferable to contain.

  Dispersant B in this embodiment is a monomer having a functional group that can be adsorbed to the pigment for the purpose of enhancing the adsorption to the pigment, and the general formulas (i), (ii), and (i) -2 described above. It is preferable that it is a high molecular compound which copolymerized the monomer represented. Specific examples of the monomer having a functional group that can be adsorbed to the pigment include a monomer having an organic dye structure or a heterocyclic structure, a monomer having an acidic group, a monomer having a basic nitrogen atom, and an ionic group. A monomer etc. can be mentioned. Among these, monomers having an organic dye structure or a heterocyclic structure are preferable from the viewpoint of the adsorptive power to the pigment.

  The monomer having an organic dye structure or a heterocyclic structure is preferably one selected from the group consisting of a monomer represented by the following general formula (11), a maleimide, and a maleimide derivative. Among these, a monomer represented by the following general formula (11) is particularly preferable.

In the general formula (11), R ¹¹ represents a hydrogen atom or an alkyl group. R ¹² represents a single bond or a divalent linking group. Y represents -CO-, -C (= O) O-, -CONH-, -OC (= O)-, or a phenylene group. Z represents a group having a nitrogen-containing heterocyclic group.

As the alkyl group represented by R ¹¹ in the general formula (11), an alkyl group having 1 to 12 carbon atoms is preferable, an alkyl group having 1 to 8 carbon atoms is more preferable, and an alkyl group having 1 to 4 carbon atoms is particularly preferable. preferable. When the alkyl group represented by R ¹¹ has a substituent, the substituent is preferably, for example, an alkoxy group such as a hydroxy group, a methoxy group, an ethoxy group, or a cyclohexyloxy group. As this alkoxy group, a C1-C5 thing is preferable and a C1-C3 thing is preferable.

Specific examples of preferable alkyl group represented by R ¹¹ in the general formula (11) include, for example, methyl group, ethyl group, propyl group, n-butyl group, i-butyl group, t-butyl group, n- Examples include a hexyl group, a cyclohexyl group, a 2-hydroxyethyl group, a 3-hydroxypropyl group, a 2-hydroxypropyl group, and a 2-methoxyethyl group. Among them, R ¹ is most preferably a hydrogen atom or a methyl group.

As a bivalent coupling group represented by R < ¹² > in General formula (11), the bivalent group containing an alkylene group or an alkylene group is preferable. The alkylene group is preferably an alkylene group having 1 to 12 carbon atoms, more preferably an alkylene group having 1 to 12 carbon atoms, still more preferably an alkylene group having 1 to 8 carbon atoms, and an alkylene group having 1 to 4 carbon atoms. Particularly preferred. When this alkylene group has a substituent, examples of the substituent include a hydroxy group. Specific examples of the preferable alkylene group represented by R ¹² include a methylene group, an ethylene group, a propylene group, a trimethylene group, and a tetramethylene group.

As the divalent group containing an alkylene group represented by R ¹² in the general formula (11), two or more of the above alkylene groups are linked via a hetero atom (for example, an oxygen atom, a nitrogen atom, or a sulfur atom). It may be. ^The divalent group containing an alkylene group represented by ^{R 12,} the end towards which binds to Z in the alkylene group, -O -, - S -, - C (= O) O -, - CONH-, -C (= O) S-, -NHCONH-, -NHC (= O) O-, -NHC (= O) S-, -OC (= O)-, -OCONH-, and -NHCO- A hetero atom selected from or a partial structure containing a hetero atom may be bonded.

  Specific examples of the nitrogen-containing heterocyclic structure constituting the nitrogen-containing heterocyclic group represented by Z in the general formula (11) include, for example, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyrrole ring, an imidazole ring, and a triazole ring. , Tetrazole ring, indole ring, quinoline ring, acridine ring, phenothiazine ring, phenoxazine ring, acridone ring, anthraquinone ring, benzimidazole structure, benztriazole structure, benzthiazole structure, cyclic amide structure, cyclic urea structure, and cyclic imide structure The thing which has is mentioned. These nitrogen-containing heterocyclic structures may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, an aliphatic ester group, an aromatic ester group, and an alkoxycarbonyl group. Is mentioned.

  The nitrogen-containing heterocyclic group represented by Z is more preferably a group having a nitrogen-containing heterocyclic structure having 6 or more carbon atoms, and a nitrogen-containing heterocyclic structure having 6 to 12 carbon atoms. Particularly preferred is a group having Specific examples of the nitrogen-containing heterocyclic structure having 6 or more carbon atoms include phenothiazine ring, phenoxazine ring, acridone ring, anthraquinone ring, benzimidazole structure, benztriazole structure, benzthiazole structure, cyclic amide structure, cyclic urea A structure and a cyclic imide structure are preferable, and a structure represented by the following general formula (12), (13) or (14) is particularly preferable.

In the general formula (12), X represents a single bond, an alkylene group (for example, a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, etc.), -O-, -S-, -NR ^A- , and It is one selected from the group consisting of —C (═O) —. Here, R ^A represents a hydrogen atom or an alkyl group. When R ^A represents an alkyl group, the alkyl group is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, or an n-propyl group. I-propyl group, n-butyl group, t-butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, n-octadecyl group and the like. Among the above, as X in the general formula (12), a single bond, a methylene group, —O—, or —C (═O) — is preferable, and —C (═O) — is particularly preferable.

In General Formula (14), Y and Z each independently represent —N═, —NH—, —N (R ^B ) —, —S—, or —O—. R ^B represents an alkyl group, and the alkyl group is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, or an n-propyl group. I-propyl group, n-butyl group, t-butyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, n-octadecyl group and the like. Among the above, as Y and Z in the general formula (14), —N═, —NH—, and —N (R ^B ) — are particularly preferable. As a combination of Y and Z, a combination (imidazolyl group) in which one of Y and Z is —N═ and the other is —NH— is preferable.

  In general formula (12), (13), or (14), ring A, ring B, ring C, and ring D each independently represent an aromatic ring. Examples of the aromatic ring include a benzene ring, naphthalene ring, indene ring, azulene ring, fluorene ring, anthracene ring, pyridine ring, pyrazine ring, pyrimidine ring, pyrrole ring, imidazole ring, indole ring, quinoline ring, acridine ring, Examples include phenothiazine ring, phenoxazine ring, acridone ring, anthraquinone ring, among others, benzene ring, naphthalene ring, anthracene ring, pyridine ring, phenoxazine ring, acridine ring, phenothiazine ring, phenoxazine ring, acridone ring, anthraquinone ring Are preferable, and a benzene ring, a naphthalene ring, and a pyridine ring are particularly preferable.

  Specifically, examples of the ring A and ring B in the general formula (12) include a benzene ring, a naphthalene ring, a pyridine ring, a pyrazine ring, and the like. Examples of the ring C in the general formula (13) include a benzene ring, a naphthalene ring, a pyridine ring, and a pyrazine ring. Examples of the ring C in the general formula (14) include a benzene ring, a naphthalene ring, a pyridine ring, and a pyrazine ring. Among the structures represented by the general formula (12), (13) or (14), a benzene ring or a naphthalene ring is more preferable from the viewpoint of dispersibility and stability over time of the dispersion, and the general formula (12) or In (14), a benzene ring is more preferred, and in general formula (13), a naphthalene ring is more preferred.

  In addition, the maleimide derivative in the present invention means a maleimide in which the N position is substituted with a substituent such as an alkyl group or an aryl group.

  Hereinafter, preferred specific examples (monomers M-1 to M-33) of the monomer represented by the general formula (11), maleimide, and maleimide derivatives are listed below, but the present invention is limited thereto. It is not a thing.

  In the present embodiment, the dispersant B includes only one type of repeating unit derived from one monomer selected from the group consisting of the monomer represented by the general formula (11), maleimide, and a maleimide derivative. It may contain, and may contain 2 or more types.

  In the dispersant B in this embodiment, the content of the repeating unit derived from one monomer selected from the group consisting of the monomer represented by the general formula (11), maleimide, and maleimide derivative is: When all the repeating units contained in the polymer are 100% by mass, the content is preferably 5% by mass or more, and more preferably 10% by mass to 50% by mass. That is, in order to effectively suppress the formation of secondary aggregates, which are aggregates of primary particles of the pigment, or to effectively weaken the cohesive force of the secondary aggregates, it is represented by the general formula (11). The content of polymerized units derived from one monomer selected from the group consisting of monomers, maleimides, and maleimide derivatives is preferably 5% by mass or more. From the viewpoint of developability when producing a color filter from a colored photosensitive composition containing a pigment dispersion, the monomer represented by the general formula (1), maleimide, and maleimide derivatives The content of polymerized units derived from one selected monomer is preferably 50% by mass or less.

  Examples of the monomer having an acidic group include a vinyl monomer having a carboxyl group and a vinyl monomer having a sulfonic acid group. Examples of the vinyl monomer having a carboxyl group include (meth) acrylic acid, vinyl benzoic acid, maleic acid, maleic acid monoalkyl ester, fumaric acid, itaconic acid, crotonic acid, cinnamic acid, and acrylic acid dimer. Further, 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, or cyclohexanedicarboxylic anhydride, ω-carboxy-polycaprolactone Mono (meth) acrylates can also be used. Moreover, you may use anhydride containing monomers, such as maleic anhydride, itaconic anhydride, and citraconic anhydride, as a precursor of a carboxyl group. Of these, (meth) acrylic acid is particularly preferred from the viewpoints of copolymerizability, cost, solubility, and the like.

  Examples of the vinyl monomer having a sulfonic acid group include 2-acrylamido-2-methylpropanesulfonic acid, and examples of the vinyl monomer having a phosphoric acid group include phosphoric acid mono (2-acryloyloxyethyl ester) and phosphoric acid mono (1-methyl-2-acryloyloxyethyl ester) and the like.

  The dispersant B in this embodiment preferably includes a repeating unit derived from a monomer having an acidic group as described above. By including such a repeating unit, when the pigment dispersion of the present invention is applied to a colored photosensitive composition, the development removability of an unexposed portion is excellent.

  Dispersant B in this embodiment may contain only one type of repeating unit derived from a monomer having an acidic group, or may contain two or more types. In the dispersant B, the content of the repeating unit derived from the monomer having an acidic group is preferably 50 mgKOH / g or more, particularly preferably 50 mgKOH / g to 200 mgKOH / g. That is, in terms of suppressing the formation of precipitates in the developer, the content of the repeating unit derived from the monomer having an acidic group is preferably 50 mgKOH / g or more. In order to effectively suppress the formation of secondary aggregates, which are aggregates of primary particles of the pigment, or to effectively weaken the cohesive force of the secondary aggregates, a repeating unit derived from a monomer having an acidic group The content of is preferably 50 mgKOH / g to 200 mgKOH / g.

  As a monomer having a basic nitrogen atom, (meth) acrylic acid ester, (meth) acrylic acid N, N-dimethylaminoethyl, (meth) acrylic acid N, N-dimethylaminopropyl, (meth) acrylic acid 1 -(N, N-dimethylamino) -1,1-dimethylmethyl, (meth) acrylic acid N, N-dimethylaminohexyl, (meth) acrylic acid N, N-diethylaminoethyl, (meth) acrylic acid N, N -Diisopropylaminoethyl, N, N-di-n-butylaminoethyl (meth) acrylate, N, N-di-i-butylaminoethyl (meth) acrylate, morpholinoethyl (meth) acrylate, (meth) Piperidinoethyl acrylate, 1-pyrrolidinoethyl (meth) acrylate, N, N-methyl-2-pyrrolidyl (meth) acrylate And (meth) acrylamides include N- (N ′, N′-dimethylaminoethyl) acrylamide, N- (N ′, N ′), and the like. -Dimethylaminoethyl) methacrylamide, N- (N ', N'-diethylaminoethyl) acrylamide, N- (N', N'-diethylaminoethyl) methacrylamide, N- (N ', N'-dimethylaminopropyl) Acrylamide, N- (N ′, N′-dimethylaminopropyl) methacrylamide, N- (N ′, N′-diethylaminopropyl) acrylamide, N- (N ′, N′-diethylaminopropyl) methacrylamide, 2- ( N, N-dimethylamino) ethyl (meth) acrylamide, 2- (N, N-diethylamino) ) Ethyl (meth) acrylamide, 3- (N, N-diethylamino) propyl (meth) acrylamide, 3- (N, N-dimethylamino) propyl (meth) acrylamide, 1- (N, N-dimethylamino) -1 , 1-dimethylmethyl (meth) acrylamide and 6- (N, N-diethylamino) hexyl (meth) acrylamide, morpholino (meth) acrylamide, piperidino (meth) acrylamide, N-methyl-2-pyrrolidyl (meth) acrylamide and the like Examples of styrenes include N, N-dimethylaminostyrene, N, N-dimethylaminomethylstyrene, and the like.

  Moreover, it is also possible to use a monomer having a urea group, a urethane group, a coordinating oxygen atom, a hydrocarbon group having 4 or more carbon atoms, an alkoxysilyl group, an epoxy group, an isocyanate group, or a hydroxyl group. Specific examples include monomers having the following structure.

  Examples of the monomer having an ionic group include vinyl monomers having an ionic group (anionic vinyl monomers and cationic vinyl monomers). Examples of the anionic vinyl monomer include alkali metal salts of vinyl monomers having an acidic group, salts with organic amines (eg, tertiary amines such as triethylamine and dimethylaminoethanol), and the like. As the vinyl monomer, the nitrogen-containing vinyl monomer is an alkyl halide (alkyl group: C1-18, halogen atom: chlorine atom, bromine atom or iodine atom); benzyl halide such as benzyl chloride or benzyl bromide; Alkylsulfonic acid esters such as acids (alkyl groups: C1-18); arylsulfonic acid alkyl esters such as benzenesulfonic acid and toluenesulfonic acid (alkyl groups: C1-18); dialkyl sulfates (alkyl groups: C1-4), etc. Quaternized with dialkyldiallylane Such as salt, and the like.

  The monomer having a functional group capable of adsorbing to the pigment can be appropriately selected according to the type of pigment to be dispersed, and these may be used alone or in combination of two or more.

  The dispersant B in the present embodiment may further contain a repeating unit derived from a copolymerizable vinyl monomer as long as the effect is not impaired.

  Although it does not restrict | limit especially as a vinyl monomer which can be used here, For example, (meth) acrylic acid esters, crotonic acid esters, vinyl esters, maleic acid diesters, fumaric acid diesters, itaconic acid diesters, ( Preference is given to meth) acrylamides, vinyl ethers, esters of vinyl alcohol, styrenes, (meth) acrylonitrile and the like. Specific examples of such vinyl monomers include the following compounds. In addition, in this specification, when showing either or both of "acryl and methacryl", it may describe as "(meth) acryl".

  A preferred embodiment of the dispersant B in this embodiment is at least a monomer represented by the general formula (i), (ii), or (i) -2, a monomer having an organic dye structure or a heterocyclic structure, More preferably, it has at least a monomer represented by the above general formula (i) -2, a monomer represented by the above general formula (11), and an acid group. And a monomer. Thereby, it is possible to provide a pigment dispersion which is excellent in pigment adsorption and excellent in developability.

  In this embodiment, the preferred molecular weight of the dispersant B is preferably in the range of 1,000 to 100,000 in terms of mass average molecular weight (Mw) and in the range of 400 to 50,000 in terms of number average molecular weight (Mn). More preferably, the mass average molecular weight (Mw) is in the range of 5,000 to 50,000, and the number average molecular weight (Mn) is in the range of 2,000 to 30,000. In particular, the mass average molecular weight (Mw) is most preferably in the range of 8,000 to 30,000, and the number average molecular weight (Mn) is in the range of 4,000 to 12,000. From the viewpoint of effectively loosening the secondary aggregate, which is an aggregate of primary particles of the pigment, or effectively weakening the reaggregation, the mass average molecular weight (Mw) of the dispersant B is 1000 or more. It is preferable. Further, from the viewpoint of developability when a color filter is produced from a colored photosensitive composition containing a pigment dispersion, the mass average molecular weight (Mw) of the dispersant B is preferably 30000 or less.

  The dispersant B in this embodiment includes, for example, a monomer represented by the following general formula (i), (ii), or (i) -2, and another radical polymerizable compound (described above) as a copolymerization component. Can be produced by a normal radical polymerization method. In general, a suspension polymerization method or a solution polymerization method is used. Examples of the solvent used when synthesizing such a dispersant B include, for example, ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxy. Examples include ethyl acetate, 1-methoxy-2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, toluene, ethyl acetate, methyl lactate, and ethyl lactate. It is done. These solvents may be used alone or in combination of two or more. In the radical polymerization, a radical polymerization initiator can be used, and a chain transfer agent (eg, 2-mercaptoethanol and dodecyl mercaptan) can be further used.

  In the pigment dispersion of this embodiment, the content of the dispersant B is preferably a mass ratio of pigment: dispersant B = 1: 0.1 to 1: 2, more preferably 1: 0.2 to 1. : 1, more preferably 1: 0.4 to 1: 0.7.

  Moreover, in the range which does not impair the effect of this embodiment, you may use another high molecular compound simultaneously with the above-mentioned specific copolymer as needed. As other polymer compounds, natural resins, modified natural resins, synthetic resins, synthetic resins modified with natural resins, and the like are used. The natural resin is typically rosin, and the modified natural resin includes rosin derivatives, fiber derivatives, rubber derivatives, protein derivatives and oligomers thereof. Examples of the synthetic resin include an epoxy resin, an acrylic resin, a maleic acid resin, a butyral resin, a polyester resin, a melamine resin, a phenol resin, and a polyurethane resin. Examples of synthetic resins modified with natural resins include rosin-modified maleic acid resins and rosin-modified phenolic resins. Synthetic resins include polyamidoamine and its salt, polycarboxylic acid and its salt, high molecular weight unsaturated acid ester, polyurethane, polyester, poly (meth) acrylate, (meth) acrylic copolymer, naphthalenesulfonic acid formalin condensate Is mentioned.

[Photocurable composition]
The photocurable composition contains a dispersion of the pigment fine particles, a photopolymerizable compound, and a photopolymerization initiator, and preferably further contains an alkali-soluble resin. The organic pigment fine particles and the method for producing the dispersion have already been described in detail. The content of fine particles in the photocurable composition is preferably 3 to 90% by mass with respect to the total solid content (in the present invention, the total solid content refers to the total composition excluding the organic solvent), and 20 -80 mass% is more preferable, and 25-60 mass% is further more preferable. If this amount is too large, the viscosity of the dispersion increases, which may cause problems in production suitability. If the amount is too small, the coloring power is not sufficient. Moreover, you may use it in combination with a normal pigment for toning. As the pigment, those described above can be used.

  The photopolymerizable compound (hereinafter sometimes referred to as a polymerizable monomer or a polymerizable oligomer) is a polyfunctional monomer that has two or more ethylenically unsaturated double bonds and undergoes addition polymerization upon irradiation with light. Is preferred. Examples of such a photopolymerizable compound include compounds having at least one addition-polymerizable ethylenically unsaturated group in the molecule and having a boiling point of 100 ° C. or higher at normal pressure. Examples include monofunctional acrylates and monofunctional methacrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and phenoxyethyl (meth) acrylate; polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) ) Acrylate, trimethylolethane triacrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane diacrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, hexane All di (meth) acrylate, trimethylolpropane tri (acryloyloxypropyl) ether, tri (acryloyloxyethyl) isocyanurate, tri (acryloyloxyethyl) cyanurate, glycerin tri (meth) acrylate; multifunctional such as trimethylolpropane and glycerin Polyfunctional acrylates and polyfunctional methacrylates such as those obtained by adding ethylene oxide or propylene oxide to alcohol and then (meth) acrylated can be mentioned. Further, as described in JP-A-10-62986, general formulas (1) and (2), a compound obtained by adding ethylene oxide or propylene oxide to a polyfunctional alcohol and then (meth) acrylated is also suitable. As mentioned.

Further, urethane acrylates described in JP-B-48-41708, JP-B-50-6034 and JP-A-51-37193; JP-A-48-64183, JP-B-49-43191 And polyester acrylates described in Japanese Patent Publication No. 52-30490; polyfunctional acrylates and methacrylates such as epoxy acrylates which are reaction products of epoxy resin and (meth) acrylic acid.
Among these, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol penta (meth) acrylate are preferable.
In addition, “polymerizable compound B” described in JP-A-11-133600 can also be mentioned as a preferable example.

  The photopolymerizable compound may be used alone or in combination of two or more. The content of the photocurable composition with respect to the total solid content is generally 5 to 50% by mass, and 10 to 40% by mass. Is preferred. If this amount is too large, it becomes difficult to control the developability, which causes a problem in production suitability. If the amount is too small, the curing power during exposure is insufficient.

  As a photopolymerization initiator or a photopolymerization initiator system (in the present invention, a photopolymerization initiator system refers to a mixture that exhibits a photopolymerization initiation function by a combination of a plurality of compounds), U.S. Pat. No. 2,367,660 Vicinal polyketaldonyl compounds disclosed in US Pat. No. 2,448,828, acyloin ether compounds described in US Pat. No. 2,448,828, α-hydrocarbon-substituted fragrances described in US Pat. No. 2,722,512 Group acyloin compounds, polynuclear quinone compounds described in US Pat. Nos. 3,046,127 and 2,951,758, triarylimidazole dimers described in US Pat. No. 3,549,367 and p-amino ketones, Benzothiazole compounds and trihalomethyl-s-triazines described in Japanese Patent No. 51-48516 Compound, trihalomethyl are described in U.S. Patent No. 4239850 - triazine compounds include U.S. Patent trihalomethyl oxadiazole compounds described in No. 4,212,976 specification or the like. In particular, trihalomethyl-s-triazine, trihalomethyloxadiazole, and triarylimidazole dimer are preferable.

  In addition, “polymerization initiator C” described in JP-A-11-133600, oxime-based compounds such as 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) oxime, O— Benzoyl-4 '-(benzmercapto) benzoyl-hexyl-ketoxime, 2,4,6-trimethylphenylcarbonyl-diphenyl phosphonyl oxide, hexafluorophospho-trialkylphenyl phosphonium salt and the like may be mentioned as suitable ones. it can.

  The photopolymerization initiator or the photopolymerization initiator system may be used alone or in combination of two or more, but it is particularly preferable to use two or more. When at least two kinds of photopolymerization initiators are used, display characteristics, particularly display unevenness, can be reduced. The content of the photopolymerization initiator or the photopolymerization initiator system with respect to the total solid content of the photocurable composition is generally 0.5 to 20% by mass, and preferably 1 to 15% by mass. If this amount is too large, the sensitivity becomes too high and control becomes difficult. If the amount is too small, the exposure sensitivity becomes too low.

  The alkali-soluble resin can be added at the time of preparing a photocurable composition or an ink-jet ink for a color filter, but it is also preferably added at the time of producing the fine particle dispersion or at the time of forming fine particles. It is also possible to add the alkali-soluble resin to both or one of the poor solvents for adding the water-insoluble compound solution and the water-insoluble compound solution to form fine particles of the water-insoluble compound. Alternatively, it is also preferable to add an alkali-soluble resin solution when forming fine particles of a water-insoluble compound in a separate system.

  As the alkali-soluble resin, a binder having an acidic group is preferable, and an alkali-soluble polymer having a polar group such as a carboxylic acid group or a carboxylic acid group in the side chain is preferable. Examples thereof include JP-A-59-44615, JP-B-54-34327, JP-B-58-12577, JP-B-54-25957, JP-A-59-53836, and JP-A-57-36. A methacrylic acid copolymer, an acrylic acid copolymer, an itaconic acid copolymer, a crotonic acid copolymer, a maleic acid copolymer, a partially esterified maleic acid copolymer as described in JP-A-59-71048 Etc. Moreover, the cellulose derivative which has a carboxylic acid group, carboxylate, etc. in a side chain can also be mentioned, In addition to this, what added the cyclic acid anhydride to the polymer which has a hydroxyl group can also be used preferably. As particularly preferred examples, copolymers of benzyl (meth) acrylate and (meth) acrylic acid described in US Pat. No. 4,139,391, benzyl (meth) acrylate and (meth) acrylic acid are used. And multi-component copolymers with other monomers.

  The alkali-soluble resin may be used alone or in the form of a composition used in combination with a normal film-forming polymer. The amount of water-insoluble compound added to 100 parts by mass of the fine particles is 10 to 200 masses. Part is general, and 25-100 mass parts is preferable.

  In addition, in order to improve the crosslinking efficiency, the side chain of the alkali-soluble resin may have a polymerizable group, and a UV curable resin, a thermosetting resin, or the like is also useful. Furthermore, as the alkali-soluble resin, a resin having a water-soluble atomic group in a part of the side chain can be used. As for content of an organic solvent, 10-95 mass% is preferable with respect to photocurable composition whole quantity. In addition, an appropriate surfactant, a thermal polymerization inhibitor, an ultraviolet absorber, an adhesion aid, other additives, and the like can be contained in the photocurable composition.

The photocurable composition can be made into an inkjet ink by adjusting the composition appropriately. In addition to the color filter, the inkjet ink may be a normal inkjet ink such as for printing. Among them, the inkjet ink for the color filter is preferable.
The ink-jet ink is not particularly limited as long as it contains the water-insoluble compound fine particles, and preferably contains the water-insoluble compound fine particles in a medium containing a polymerizable monomer and / or a polymerizable oligomer. Here, as the polymerizable monomer and / or polymerizable oligomer, those described above for the photocurable composition can be used.
At this time, the ink characteristics used at the time of ejection, the ink spraying method, the ink jet head form, the pattern shape of the color filter, and the formation method thereof are disclosed in JP 2008-138194 A and the preferred range. It is the same.

  The components contained in the coating film using the photocurable composition are the same as those already described. Further, the properties of the coating film using the photocurable composition and the coating method on the substrate are the same as those disclosed in Japanese Patent Application Laid-Open No. 2008-138194 and preferable ranges.

[Color filter]
The pixel of the color filter of the present invention is preferably formed using the above-described pigment fine particle dispersion or a redispersion in which the solvent is switched, and is preferably excellent in contrast. In the present invention, the contrast represents the ratio of the amount of transmitted light between two polarizing plates when the polarization axis is parallel and vertical (“1990 Seventh Color Optical Conference, 512-color display 10.4”). "Refer to" Color TFT for size TFT-LCD, Ueki, Koseki, Fukunaga, Yamanaka "etc.). The high contrast of the color filter means that the bright and dark discrimination when combined with the liquid crystal can be increased, which is a very important performance in order to replace the liquid crystal display with a CRT.

  When the color filter is used for a television, the chromaticity of each single color of red (R), green (G), and blue (B) by the C light source is the value shown in the table below (hereinafter referred to as the present value). In the invention, the difference (ΔE) from the “target chromaticity”) is preferably in the range of 5 or less, more preferably 3 or less, and particularly preferably 2 or less.

x y Y
------------------------
R 0.647 0.334 23.0
G 0.284 0.599 57.6
B 0.137 0.095 10.7
------------------------

In the present invention, the chromaticity is measured with a microspectrophotometer (manufactured by Olympus Optical Co., Ltd .; OSP100 or 200), calculated as a result of the F10 light source field of view of 2 degrees, and expressed as an xyY value in the xyz color system. Further, the difference from the target chromaticity is represented by a color difference of the La ^* b ^* color system. In the present invention, the Y value is particularly preferably 20 or more, and more preferably 23 or more. If the Y value is equal to or greater than the lower limit, the brightness of the image is inferior and a dark image is produced.

  A liquid crystal display device provided with a color filter has a high contrast and is excellent in descriptive power such as black spots, and the VA method is particularly preferable. It can also be suitably used as a large-screen liquid crystal display device such as a notebook personal computer display or a television monitor. The color filter can be used for a CCD device and exhibits excellent performance.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail based on an Example, this invention is limited to this and is not interpreted. In the examples, “part” and “%” are based on mass unless otherwise specified.

(Synthesis example) Example according to the invention of the compound (Synthesis example 1)
In a 1000 mL three-necked flask, 20 parts by mass of PR254, 400 parts by mass of dimethyl sulfoxide and 18.48 parts by mass of tert-butoxy potassium were added and dissolved by stirring. To this solution, 14.25 parts by mass of chloroacetanilide was added and stirred at 60 ° C. for 3 hours. The reaction solution was discharged into 1000 parts by mass of ice water containing 20 parts by mass of hydrochloric acid to precipitate a solid. The precipitate was washed with 2000 parts by mass of water, and then washed with 600 parts by mass of methanol to obtain compound a-1. Subsequently, 40 parts by mass of sulfuric acid was added to 10 parts by mass of Compound a-1, 21.32 parts by mass of fuming sulfuric acid was added, and the mixture was stirred at room temperature for 1 hour. After completion of the reaction, the reaction solution was poured into 200 parts by mass of ice water with stirring, and the resulting precipitate was filtered and washed to obtain 6.1 parts by mass of compound a-1 (melting point: 126 ° C.). .

(Synthesis Examples 2-9)
Exemplified compounds were obtained in the same manner except that the chloroacetanilide of Synthesis Example 1 was changed as shown in Table A below.

(Example I, Comparative Example I)
Example 1
[Preparation of organic pigment nanoparticle dispersion]
Dimethyl sulfoxide (manufactured by Wako Pure Chemical Industries, Ltd.) is used as a good solvent, and pigment C.I. I. 50 g of Pigment Red 254 (IRGAZIN DPP RED BO, trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.) was dispersed, and 52.3 g of a 25% tetramethylammonium hydroxide 25% methanol solution was added dropwise to prepare a pigment solution. . As a result of measuring the viscosity of this pigment solution using Viscomate VM-10A-L (trade name, manufactured by CBC Materials), the viscosity when the liquid temperature of the pigment solution was 24.5 ° C. was 14.3 mPa · s. Separately, 1000 ml of ion-exchanged water containing 19 g of a 1 mol / l hydrochloric acid aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was prepared as a poor solvent.
Here, the temperature of the solution was controlled at 10 ° C., and the pigment solution was added to 1000 ml of a poor solvent stirred at 500 rpm with a GK-0222-10 type Lamond Stirrer (trade name, manufactured by Fujisawa Pharmaceutical Co., Ltd.). By using a non-pulsating pump (trade name, manufactured by Nippon Seimitsu Chemical Co., Ltd.), 100 ml of liquid pigment having a flow path diameter of 1.1 mm is injected at a flow rate of 400 ml / min. To prepare a dispersion (dispersion 1) of crystalline organic pigment nanoparticles. The organic pigment nanoparticle dispersion (dispersion 101a) was temperature-controlled at 5 ° C. and stirred for 2 hours.

[Preparation of organic pigment powder]
The organic pigment nanoparticle dispersion liquid (dispersion 101a) prepared by the above procedure was subjected to H-112 type (trade name, manufactured by Kokusan Co., Ltd.) centrifugal filter and P89C type (trade name, manufactured by Shikishima Canvas Co., Ltd.). ) Using a filter cloth, the mixture was concentrated at 5000 rpm for 90 minutes, and then 1100 g of ion-exchanged water was added and mixed, followed by centrifugal filtration in the same manner. Again, 1100 g of ion-exchanged water was added and mixed, followed by centrifugal filtration. The obtained organic pigment nanoparticle concentrated paste 101b was recovered.
The organic pigment nanoparticle concentrated paste was dried in an oven at 100 ° C. for 2 hours to obtain an organic pigment powder 101c having an average particle size of 25 nm.

[Preparation of organic pigment dispersion composition]
The organic pigment powder was pulverized to 180 μm or less with a mortar, and then it was made into an organic pigment dispersion composition 101d having the following composition, which was uniformly stirred and mixed.
9.7 g of the organic pigment powder 101c
Pigment derivative 1 2.0 g
Pigment derivative 2 2.3 g
Dispersant resin 1 12.1 g
Propylene glycol monomethyl ether acetate
112.7g
Example Compound a-1 3.5 g

Main chain Mn: 600, graft amount 9.3 mol% (vs. total amine),
Acid value 10mgKOH / g, Mw: 10000
Ra: —CO—nC ₇ H ₁₅ or hydrogen atom v: 40, w: 5, x: 10, y + z: 45

  Using an organic pigment dispersion composition 101d having the above composition in a sand grinder mill BSG-01 (trade name, manufactured by AIMEX), using zirconia beads having a diameter of 0.5 mm, 1500 rpm for 1 hour, and then zirconia beads having a diameter of 0.05 mm. And dispersed at 2500 rpm for 2 hours to obtain an organic pigment dispersion composition 101.

(Examples 2-6, Comparative Example 1, Reference Example 1)
Pigment dispersions (dispersions 102d to 106d, c01d, and s01d were obtained in the same manner as in Example 1 except that the compound added to the pigment solution was changed to the example compound a-1 and changed as shown in Table 1 below. Furthermore, a pace, a powder, and an organic pigment dispersion composition (dispersions 102 to 106, c01, s01) were prepared using the respective dispersion samples, and the dispersions c01 and s01 were replaced with the compound a-1. It means that the following compounds c-1 and DPC-14 were used.

(Example 7)
C. I. Pigment Red 254 (IRGAPHOR RED BT-CF, trade name, manufactured by Ciba Specialty Chemicals) 40 g (average particle size 60 nm), pigment derivative 1 1.6 g, pigment derivative 2 1.8 g, propylene glycol monomethyl The mixture was mixed with 125 ml of ether acetate, and the mixed solution was mixed and dispersed for 3 hours by a bead mill (zirconia beads 0.3 mm) to prepare a pigment dispersion (dispersion 107a). 3.5 g of Exemplified Compound a-1 was added to 40 g of the dispersion and stirred with a stirrer to obtain Dispersion 107b. Thereafter, in the same manner as in Example 1, paste, powder and organic pigment dispersion composition 107 were prepared. As a result of evaluating the same items as in Example 1 above, it was confirmed that there were effects in other items although the contrast was slightly inferior.

(Evaluation of pigment dispersion composition)
Each sample of the obtained pigment dispersion composition was evaluated as follows. The results are summarized in Table 1.

[Measurement of Particle Size Distribution and Number Average Primary Particle Size (Dp) of Pigment Fine Particles]
The particle size distribution of the pigment particles contained in the dispersion was measured under the following conditions, and the ratio P of the number of particles having a particle size of 20 nm to 30 nm and a number average primary particle size Dp were calculated.
・ TEM imaging equipment: Hitachi, H-7650 electron microscope (trade name)
Accelerating voltage: 110 kV
(A tomographic observation was performed, and a surface with little overlap between particles was extracted from the 3D reconstruction data to obtain a projected area of the particles.)
Image measuring device: KS-400 (trade name) manufactured by Carl Zeiss
(The TEM image of 5000 pigment particles selected at random was measured, the equivalent circle diameter was calculated from the projected area, and the above ratios P and Dp were calculated.)

[Measurement evaluation of viscosity]
About the obtained pigment dispersion composition, the viscosity η1 of the pigment dispersion composition immediately after dispersion using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., RE-85L [trade name], measurement temperature 25 ° C.). The viscosity η2 of the pigment dispersion composition after 1 week at room temperature after dispersion was measured to evaluate the degree of thickening. Here, the low viscosity indicates that the increase in viscosity due to the dispersant is suppressed, and the dispersibility and dispersion stability of the pigment are good. The increase in viscosity (viscosity η2−viscosity η1) is shown in the table.

[Measurement evaluation of contrast]
The obtained pigment dispersion composition was applied on a glass substrate, and a sample was prepared so that the thickness of the coating film after drying was 1 μm. This sample was placed between two polarizing plates, the amount of transmitted light was measured when the polarization axis was parallel and when the polarization axis was parallel, and the ratio was taken as contrast. 512 color display 10.4 “size TFT-LCD color filter, garden plant, Koseki, Fukunaga, Yamanaka”). Here, a high contrast indicates that the pigment is uniformly dispersed in a highly refined state, and thus the transmittance, that is, the coloring power is high.

  According to the results shown in the above table, the dispersion using the compound represented by the general formula (1) of the present invention in the reprecipitation method has an extremely small average particle diameter and a uniform particle diameter, so that a color filter was obtained. High contrast and brightness. Further, it can be seen that the increase in viscosity with time is suppressed, and it is suitable as an industrial color material for color filters as compared with the comparative example.

(Example II, Comparative Example II)
[Preparation of colored photosensitive composition]
Using the above pigment dispersion compositions (101 to 107, c01, s01), the following colored photosensitive compositions were prepared.

Pigment dispersion composition 2000 parts Dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd .: photopolymerizable compound) 100 parts 4- [o-bromo-pN, N-di (ethoxycarbonyl)
Aminophenyl] -2,6-di (trichloromethyl) -S-
30 parts of triazine (photopolymerization initiator), benzyl methacrylate / methacrylic acid (= 75/25 [mass ratio])
Propylene glycol monomethyl ether acetate solution of copolymer (weight average molecular weight: 12,000) (solid content 30%)
(Alkali-soluble resin) 400 parts, 1-methoxy-2-propyl acetate (solvent) 390 parts

[Preparation of color filter using colored photosensitive composition]
The prepared colored photosensitive composition (color resist solution) was applied on a 100 mm × 100 mm glass substrate (1737, manufactured by Corning) so that the x value serving as an index of color density was 0.650. It was dried in an oven at 90 ° C. for 60 seconds (pre-baking). Thereafter, the entire surface of the coating film is exposed at 200 mJ / cm ² (illuminance 20 mW / cm ² ), and the exposed coating film is a 1% aqueous solution of an alkali developer CDK-1 (manufactured by Fuji Film Electronics Materials Co., Ltd.). And rested for 60 seconds. After standing still, pure water was sprayed in a shower to wash away the developer. Then, the coating film that has been exposed and developed as described above is heat-treated in an oven at 220 ° C. for 1 hour (post-baking) to form a colored pattern (colored region) for the color filter on the glass substrate. A filter substrate (color filter) was produced.

[Evaluation of colored photosensitive composition and color filter]
The produced colored photosensitive composition and colored filter substrate (color filter) were evaluated as follows. The results are summarized in the above table.

○ Contrast of color filter (CF) A polarizing plate is placed on the coloring pattern of the color filter, and the coloring pattern is sandwiched between them. The luminance when the polarizing plate is parallel and the luminance when the polarizing plate is orthogonal are BM-5 (trade name) manufactured by Topcon Corporation. The value obtained by dividing the parallel brightness by the orthogonal brightness (= the parallel brightness / the orthogonal brightness) was used as an index for evaluating the contrast. Larger values indicate higher contrast.
○ Brightness of color filter (CF) The absorption spectrum of the sample-coated substrate used for the above-described contrast measurement was measured using an Agilent 8453 spectrophotometer. From the obtained absorption spectrum, the Y value of the coated substrate when the C light source was used was calculated. The higher the Y value, the brighter the image is, and the amount of light from the backlight can be reduced practically. Therefore, there is an advantage that a liquid crystal display with low power consumption can be provided.

  As can be seen from the above results, the compound of the general formula (I) of the present invention is less prone to thickening and excellent in production suitability as compared with conventional pigment derivatives, and exhibits high luminance when used as a color filter. This is because the pigment derivative compound of the present invention has one pigment nuclei and one sulfonic acid group linked by a linking group having a hetero atom in the molecule. This is considered to be because the polarities of specific substituents acted moderately, and the interactions among the pigment, pigment derivative, and dispersant resin were controlled in a well-balanced manner. Therefore, when a color filter is used, it is possible to achieve both extremely high contrast and high luminance.

Claims (10)

A pigment fine particle dispersion comprising pigment fine particles and a compound represented by the following general formula (1).

(In General Formula (1), X ¹ and X ² each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic group. R ¹ and R ² Each independently represents a hydrogen atom or a group represented by the following general formula (2), and at least one of R ¹ and R ² is a group represented by the following general formula (2).

(In the formula, Y represents a divalent organic linking group containing a hetero atom. A represents an alkylene group, an arylene group, or a heteroarylene group that may have a substituent. M represents an integer of 1 to 8. To express.)   The pigment fine particles are produced by mixing a solution obtained by dissolving a pigment in a good solvent and a medium that is compatible with the good solvent and becomes a poor solvent for the pigment. The pigment fine particle dispersion according to claim 1. 3. The pigment fine particles according to claim 1, wherein X ¹ and X ² are each independently a hydrogen atom, a chlorine atom, a phenyl group, a cyano group, or an alkyl group having 1 to 4 carbon atoms. Dispersion.   The pigment constituting the pigment fine particles is at least one selected from the group consisting of a diketopyrrolopyrrole pigment, a quinacridone pigment, an anthraquinone pigment, and an azo pigment. The pigment fine particle dispersion described in 1.   The pigment fine particle dispersion according to any one of claims 1 to 4, further comprising a dispersant having a polycaprolactone structure. Furthermore, the high molecular compound containing the at least 1 sort (s) of repeating unit selected from the repeating unit represented by either of the following general formula (I) and (II) is contained, The any one of Claims 1-5 characterized by the above-mentioned. 2. The pigment fine particle dispersion according to item 1.

(In the general formulas (I) and (II), R ^{21 to} R ²⁶ each independently represents a hydrogen atom or a monovalent organic group, and X ²¹ and X ²² each independently represent —CO—, —C ( ═O) O—, —CONH—, —OC (═O) —, or a phenylene group, L ²¹ and L ²² each independently represent a single bond or a divalent organic linking group, and A ²¹ And A ²² each independently represents a monovalent organic group, ma and na each independently represents an integer of 2 to 8, and p and q each independently represents an integer of 1 to 100.)   It is a color material for color filters, The pigment fine particle dispersion of any one of Claims 1-6.   A photocurable composition containing the dispersion according to any one of claims 1 to 7 and a polymerizable compound.   A color filter comprising pixels formed by curing the photocurable composition according to claim 8. A compound represented by the following general formula (1).

(In General Formula (1), X ¹ and X ² each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aromatic group. R ¹ and R ² Each independently represents a hydrogen atom or a group represented by the following general formula (2), and at least one of R ¹ and R ² is a group represented by the following general formula (2).

(In the formula, Y represents a divalent organic linking group containing a hetero atom. A represents an alkylene group, an arylene group, or a heteroarylene group that may have a substituent. M represents an integer of 1 to 8. To express.)