JP2010254835A - Pigment dispersant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment dispersant that can stably and highly miniaturize pigment particles while suppressing crystal growth of the pigment, and to provide a pigment composition that is suitable for a printing ink or a coating material, particularly, for use requiring fine dispersion of pigment particles such as inkjet ink and ink for a color filter, and has low viscosity and significantly excellent stability with time. <P>SOLUTION: The pigment dispersant is a benzimidazolone dioxane pigment dispersant expressed by formula (1). In the formula, R<SP>1</SP>and R<SP>2</SP>each represents a hydrogen atom or the like; R<SP>3</SP>to R<SP>6</SP>each represents a hydrogen atom or the like; and R<SP>7</SP>to R<SP>10</SP>each represents a hydrogen atom or the like. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pigment dispersant that makes it possible to easily obtain a fine dispersion of pigment particles and keep it in a stable state, and more specifically, a printing ink, paint, and resin using the same. The present invention relates to a pigment composition suitably used for colorants, inkjet inks, color filter inks, and the like.

  In printing inks, paints, etc., pigments are dispersed in a fine state to exert a high coloring power, and have appropriate properties such as clear color tone and gloss of printed or coated products. Further, in offset inks, gravure inks, paints, particularly ink jet inks, color filter inks, etc., it is necessary to highly refine the pigment particles in order to obtain high sharpness. At this time, a solvent salt milling method, a dry pulverization method, and the like are widely used as methods for refining the pigment particles. However, if the pigment is added together with commonly used grinding aids such as inorganic salts and solvents, pigment particles may grow at the same time due to the heat generated during grinding and the solvent added as a dispersion aid. When the mechanical force is applied for a long time, the state of the pigment particles becomes unstable, causing changes such as crystal transition. May not be obtained. In addition, since the pigment particle diameter is likely to vary particularly only by dry pulverization, finer pigment particles are more likely to cause crystal growth when controlled by solvent treatment, and are difficult to control.

  On the other hand, when the pigment is made finer, the cohesive force between the pigment particles becomes stronger, and the ink and the paint often have high viscosity. In addition, when this dispersion is produced, not only is it difficult to take out the product from the disperser and transfer the product from the disperser to a tank or the like, but in a worse case, gelation occurs during storage and the use becomes difficult. Sometimes. In order to solve such problems, it is known to use a pigment dispersant, improve the affinity between the pigment and the vehicle, and stabilize the dispersion. Agents are disclosed. For example, pigment derivatives in which functional groups such as acidic groups, basic groups, and phthalimidomethyl groups are introduced into organic pigments, and resin-type dispersants in which acidic groups and basic groups are introduced into some acrylic polymers and polyester resins have been developed. It is used alone or in combination, and the effect is obtained. Some of these have an effect of preventing pigment crystal growth.

  However, the effect of preventing pigment crystal growth of conventional pigment dispersants is that highly finely divided pigment particles, such as printing inks, paints, especially ink jet inks, and inks for color filters, are sufficient to achieve high sharpness. It is not always sufficient to obtain it stably. Furthermore, those containing highly refined pigments may not be able to obtain sufficient viscosity reduction and storage stability with the pigment dispersants described above. In addition, a large amount of energy is required to disperse finely aggregated fine pigment particles and disperse them until obtaining high gloss and transparency when they are made into a color-extracted product.

  In addition, when different types of pigments are mixed and used, the stability of the ink becomes poor, and phenomena such as color separation and sedimentation due to aggregation of the pigments occur. May cause a reduction in coloring power. In addition, the surface of the coating film of the color-extended product may cause a state failure such as a decrease in gloss and a leveling failure. Therefore, the pigment composition is highly effective in preventing pigment growth and preventing crystal growth, and can stably obtain highly refined pigment particles, and inkjet obtained by dispersing highly refined pigment particles. In addition, a pigment composition having high dispersion performance, excellent viscosity suitability, and storage stability is also desired for ink for color filters and the like.

JP 2002-88269 A JP-A-3-26767 JP-A-6-316676

  The first object of the present invention is to provide a pigment dispersant that suppresses the crystal growth of the pigment and enables the pigment particles to be stably and highly refined. The second object of the present invention is suitable for applications that require fine dispersion of pigment particles such as printing inks and paints, particularly ink jet inks and color filter inks, and has a low viscosity and greatly improved stability over time. Is to provide an excellent pigment composition.

  That is, the present invention relates to a benzimidazolone dioxazine pigment dispersant represented by the following formula (1).

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or a group represented by the following general formula (2).
R ^{3 to} R ⁶ each independently represent a hydrogen atom or an alkyl group.
R ^{7 to} R ¹⁰ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group, a nitro group, an amino group, a sulfonic acid group, a carboxylic acid group, or the following general formula (2). Represents a group.
Provided that at 1-6 of ^{R 1, R 2, R 7} ~R 10 is a group represented by the following general formula (2). )

(In general formula (2),
Y represents —R ²¹ —, —CONR ¹¹ —R ²¹ —, —NR ¹¹ —R ²¹ —, —NR ¹¹ CO—R ²¹ —, —NR ¹¹ SO ₂ —R ²¹ —, —O—R ²¹ —, It represents —S (O) _m —R ²¹ —, —SO ₂ NR ¹¹ —R ²¹ —, a triazine residue, or a linking group in which two or more of these are bonded.
Z represents ^{-COO · M, -NR 12 R 13} , phthalimide group, -SO ₃ · M, a -SO ₂ NR ¹² R ^13.
R ¹¹ represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group.
R ¹² and R ¹³ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyalkyl group, a halogen atom-substituted alkyl group, or an optionally substituted aminoalkyl group. Alternatively, R ¹² and R ¹³ may be combined to form a ring.
R ²¹ represents a direct bond, a linear or branched alkylene group having 1 to 12 carbon atoms, an arylene group, or a divalent triazine residue.
m represents an integer of 0 to 3.
k is 2 when Y contains an alkylene group, an arylene group or a triazine residue, and 1 otherwise.
M represents a hydrogen ion, a 1-3 valent metal ion, or an ammonium ion at least one of which is substituted with an alkyl group. )

  The present invention also relates to a pigment composition containing a pigment and the pigment dispersant.

  The present invention also relates to the above pigment composition, wherein the pigment contains a dioxazine pigment and / or a phthalocyanine pigment.

  In the present invention, the dioxazine pigment is C.I. I. Pigment Yellow 23 and phthalocyanine pigments are C.I. I. It is related with the said pigment composition which is pigment blue 15: 6.

  The pigment dispersant of the present invention has a high pigment particle prevention effect due to the prevention of crystal growth and particle stability of a high pigment of a novel benzimidazolone dioxazine derivative at the time of pulverization and sizing for finer pigment particles. It can be miniaturized. Among them, the pigment dispersant containing a novel benzimidazolone dioxazine derivative having a basic group or an acidic group not only exhibits excellent dispersibility in a wide range of resins, but also non-aggregation, non-crystallinity, viscosity suitability, It is easy to obtain inks and paints with excellent coating gloss, sharpness, and storage stability, printing inks, various general paints for automobiles, woods, metals, etc., backcoat paints for magnetic tape, and radiation. It can be used in pigment compositions for uses such as cure ink, ink for inkjet printers, and ink for color filters. In particular, it is a system that includes a group of blue pigments typified by dioxazine-based purple pigments and phthalocyanine-based blue pigments. It has a high effect of preventing crystal growth and particle stability, and has high dispersion performance and excellent viscosity suitability and storage. Stability is obtained.

  First, the pigment dispersant of the present invention will be described. The pigment dispersant of the present invention is a compound represented by the above general formula (1).

  In the general formula (1), symbols and subscripts have the following meanings.

R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or a group represented by the general formula (2), and R ^{3 to} R ⁶ each independently represent a hydrogen atom or an alkyl group. Indicates. R ^{7 to} R ¹⁰ are each independently represented by a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group, a nitro group, an amino group, a sulfonic acid group, a carboxylic acid group, or the general formula (2). Indicates a group. However, one to six, preferably one to four, particularly preferably one or two of R ¹ , R ² and R ^{7 to} R ¹⁰ are groups represented by the general formula (2). is there.

  In the general formula (2), symbols and subscripts have the following meanings.

Y represents —R ²¹ —, —CONR ¹¹ —R ²¹ —, —NR ¹¹ —R ²¹ —, —NR ¹¹ CO—R ²¹ —, —NR ¹¹ SO ₂ —R ²¹ —, —O—R ²¹ —, It represents —S (O) _m —R ²¹ —, —SO ₂ NR ¹¹ —R ²¹ —, a triazine residue, or a linking group in which two or more of these are bonded.
Z represents ^{-COO · M, -NR 12 R 13} , phthalimide group, -SO ₃ · M, a -SO ₂ NR ¹² R ^13.
R ¹¹ represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group.
R ²¹ represents a direct bond, a linear or branched alkylene group having 1 to 12 carbon atoms, an arylene group, or a divalent triazine residue.

  In the present invention, examples of the substituent include an alkyl group, an amino group, a nitro group, a hydroxyl group, an alkoxy group, or a halogen atom.

Here, as the alkyl group, an alkyl group having 1 to 30 carbon atoms which may have a substituent is preferable. For example, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, Dodecyl, okdadecyl, isopropyl, isobutyl, sec-butyl, tert-butyl, 1-ethylpentyl, cyclopentyl, cyclohexyl, trifluoromethyl, 2-ethylhexyl, phenacyl, 1-naphtho Ilmethyl group, 2-naphthoylmethyl group, 4-methylsulfanylphenacyl group, 4-phenylsulfanylphenacyl group, 4-dimethylaminophenacyl group, 4-cyanophenacyl group 4-methylphenacyl group, 2-methylphena Sil group, 3-fluorophenacyl group, 3-trifluoromethylphenacyl group, 3-nitro Enashiru group, and the like.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  As the alkoxy group, an alkoxy group having 1 to 30 carbon atoms which may have a substituent is preferable, for example, a methoxy group, an ethoxy group, a propyloxy group, an isopropyloxy group, a butoxy group, an isobutoxy group, a sec-butoxy group. Tert-butoxy group, pentyloxy group, isopentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, 2-ethylhexyloxy group, decyloxy group, dodecyloxy group, octadecyloxy group, ethoxycarbonylmethyl group, 2 -Ethylhexyloxycarbonylmethyloxy group, aminocarbonylmethyloxy group, N, N-dibutylaminocarbonylmethyloxy group, N-methylaminocarbonylmethyloxy group, N-ethylaminocarbonylmethyloxy group, N-octylaminocarbonylmethyl Alkoxy group, N- methyl -N- benzylaminocarbonyl methyloxy group, a benzyloxy group, and a cyanomethyloxy group.

As the aryl group, an aryl group having 6 to 30 carbon atoms which may have a substituent is preferable. For example, a phenyl group, a biphenyl group, a 1-naphthyl group, a 2-naphthyl group, a 9-anthryl group, or 9-phenanthryl. Group, 1-pyrenyl group, 5-naphthacenyl group, 1-indenyl group, 2-azurenyl group, 9-fluorenyl group, terphenyl group, quarterphenyl group, o-, m-, and p-tolyl group, xylyl group, o-, m-, and p-cumenyl, mesityl, pentarenyl, binaphthalenyl, tarnaphthalenyl, quarternaphthalenyl, heptaenyl, biphenylenyl, indacenyl, fluoranthenyl, acenaphthylenyl, aceanthrylenyl Group, phenalenyl group, fluorenyl group, anthryl group, bianthracenyl group, ter Nthracenyl group, quarteranthracenyl group, anthraquinolyl group, phenanthryl group, triphenylenyl group, pyrenyl group, chrysenyl group, naphthacenyl group, preadenyl group, picenyl group, perylenyl group, pentaphenyl group, pentacenyl group, tetraphenylenyl group, Examples include a hexaphenyl group, a hexacenyl group, a rubicenyl group, a coronenyl group, a trinaphthylenyl group, a heptaphenyl group, a heptacenyl group, a pyranthrenyl group, and an ovalenyl group.
As the amino group, an amino group having 1 to 30 carbon atoms which may have a substituent is preferable. For example, a methylamino group, a dimethylamino group, a diethylamino group, a dipropylamino group, a diisopropylamino group, a dibutylamino group, Di (sec-butyl) amino group, di (tert-butyl) amino group, dipentylamino group, diisopentylamino group, dineopentylamino group, di (tert-pentyl) amino group, dihexylamino group, diisohexyl Amino group, diheptylamino group, dioctylamino group, dinonylamino group, didecylamino group, diundecylamino group, didodecylamino group, ditridecyl group, ditetradecylamino group, dipentadecylamino group, dihexadecylamino group, di Heptadecylamino group, dioctadecylamino group, dinonadecylamino group, dipheni Amino group, dibiphenylylamino group, bis (terphenylyl) amino group, bis (quarterphenylyl) amino group, di (o-tolyl) amino group, di (m-tolyl) amino group, di (p-tolyl) amino Group, dixylylamino group, di (o-cumenyl) amino group, di (m-tolyl) amino group, di (p-cumenyl) amino group, dimesitylamino group, dipentalenylamino group, diindenylamino group, Dinaphthylamino group, bis (binaphthalenyl) amino group, bis (tarnaphthalenyl) amino group, bis (quarternaphthalenyl) amino group, diazurenylamino group, diheptarenylamino group, bis (biphenylenyl) amino group, diyne Dacenylamino group, difluoranthenylamino group, diacenaphthylenylamino group, bis (aceanthrylenyl) amino group, diphenalenylamino group, difluorenyl Ruamino group, dianthrylamino group, bis (bianthracenyl) amino group, bis (teranthracenyl) amino group, bis (quarteranthracenyl) amino group, bis (anthraquinolyl) amino group, diphenanthrylamino group, ditril Phenylenylamino group, dipyrenylamino group, dicricenylamino group, dinaphthacenylamino group, dipleyadenylamino group, dipicenylamino group, diperylenylamino group, bis (pentaphenyl) amino group, dipentacenyl Amino group, bis (tetraphenylenyl) amino group, bis (hexaphenyl) amino group, dihexacenylamino group, dirubicenylamino group, dicoronenylamino group, bis (trinaphthylenyl) amino group, bis (hepta) Phenyl) amino group, diheptacenylamino group, dipyranthrenylamino group, diovalenyl group Group, methylethylamino group, methylpropylamino group, methylbutyl group, methylpentylamino group, methylhexylamino group, ethylpropylamino group, ethylbutylamino group, ethylpentylamino group, ethylhexylamino group, propylbutylamino group, Propylpentylamino group, propylhexylamino group, butylpentylamino group, butylhexylamino group, pentylhexylamino group, phenylbiphenylylamino group, phenylterphenylylamino group, phenylnaphthylamino group, phenylanthrylamino group, phenyl Phenanthrylamino group, biphenylylnaphthylamino group, biphenylylanthrylamino group, biphenylylphenanthrylamino group, biphenylylterphenylylamino group, naphthylanthrylamido Group, naphthylphenanthrylamino group, naphthylterphenylylamino group, anthrylphenanthrylamino group, anthrylterphenylylamino group, methylphenylamino group, methylbiphenylylamino group, methylnaphthylamino group, methylan Tolylamino group, methylphenanthrylamino group, methylterphenylylamino group, ethylphenylamino group, ethylbiphenylylamino group, ethylnaphthylamino group, ethylanthrylamino group, ethylphenanthrylamino group, ethylterphenyl Rylamino group, propylphenylamino group, propylbiphenylylamino group, propylnaphthylamino group, propylanthrylamino group, propylphenanthrylamino group, propylterphenylylamino group, butylphenylamino group, butylbiphenyl Phenylylamino, butylnaphthylamino, butylanthrylamino, butylphenanthrylamino, butylterphenylylamino, pentylphenylamino, pentylbiphenylylamino, pentylnaphthylamino, pentylanthrylamino Group, pentylphenanthrylamino group, pentylterphenylylamino group, hexylphenylamino group, hexylbiphenylylamino group, hexylnaphthylamino group, hexylanthrylamino group, hexylphenanthrylamino group, hexylterphenylylamino group Group, heptylphenylamino group, heptylbiphenylylamino group, heptylnaphthylamino group, heptylanthrylamino group, heptylphenanthrylamino group, heptylterphenylylamino group, octylpheny Amino group, octylbiphenylylamino group, octylnaphthylamino group, octylanthrylamino group, octylphenanthrylamino group, octylterphenylylamino group, bis [4- (α, α'-dimethylbenzyl) phenyl] amino Groups and the like.
Furthermore, the hydrogen atom of the alkyl group, alkoxy group, aryl group and amino group may be further substituted with another substituent.

  Examples of such substituents include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, alkoxy groups such as methoxy group, ethoxy group and tert-butoxy group, aryl such as phenoxy group and p-tolyloxy group Oxy group, methoxycarbonyl group, butoxycarbonyl group, alkoxycarbonyl group such as phenoxycarbonyl group, acetoxy group, propionyloxy group, acyloxy group such as benzoyloxy group, acetyl group, benzoyl group, isobutyryl group, acryloyl group, methacryloyl group, Acyl groups such as methoxalyl group, alkylsulfanyl groups such as methylsulfanyl group, tert-butylsulfanyl group, arylsulfanyl groups such as phenylsulfanyl group, p-tolylsulfanyl group, alkylamino groups such as methylamino group, cyclohexylamino group, etc. Amino group, dimethylamino group, diethylamino group, morpholino group, piperidino group and other dialkylamino groups, phenylamino group, p-tolylamino group and other arylamino groups, methyl group, ethyl group, tert-butyl group, dodecyl group, etc. In addition to aryl groups such as alkyl groups, phenyl groups, p-tolyl groups, xylyl groups, cumenyl groups, naphthyl groups, anthryl groups, phenanthryl groups, and heterocyclic groups such as furyl groups and thienyl groups, hydroxy groups, carboxy groups, Formyl group, mercapto group, sulfo group, mesyl group, p-toluenesulfonyl group, amino group, nitro group, cyano group, trifluoromethyl group, trichloromethyl group, trimethylsilyl group, phosphinico group, phosphono group, trimethylammonium group, Dimethylsulfonyl group, triphenylphenacylphosphonium group And the like.

Further, R ¹² and R ¹³ may be combined together to form a ring. Examples of the ring formed including a nitrogen atom to which R ¹² and R ¹³ are bonded include a piperazine ring, a piperidine ring, a pyrrolidine ring, and a morpholine ring.

  Examples of the phthalimide group which may have a substituent include phthalimide group, 4-nitrophthalimide group, 4-chlorophthalimide group, tetrachlorophthalimide group, (4,6-bis (phthalimidomethylamino) -1,3,5 -A triazine) -2-ylamino group etc. are mentioned.

  Examples of the 1-3 valent metal ions include sodium ions, potassium ions, calcium ions, strontium ions, barium ions, and aluminum ions.

In the present invention, when M can form a pair with a counter ion of two or more —SO ₃ groups or —COO groups, the counter ion may be the same or different. Further, a part of the counter ion may be other than —SO ₃ group or —COO group.

  Ammonium ions at least one of which is substituted with an alkyl group include octyl ammonium ion, dodecyl ammonium ion, hexadecyl ammonium ion, octadecyl ammonium ion, dimethyl didecyl ammonium ion, dimethyl didodecyl ammonium ion, dimethyl dioctadecyl ammonium ion, Examples include trimethyldodecyl ammonium ion and trimethyl octadecyl ammonium ion.

  Among these, while having a high anti-crystallization effect, it not only exhibits excellent dispersibility to a wide range of resins, but also has excellent non-aggregation, non-crystallinity, viscosity suitability, coating gloss, sharpness, and storage stability. The benzimidazolone dioxazine pigment dispersant according to the present invention, which can easily achieve an ink and a paint, has a substituent represented by the general formula (3) or the general formula (4).

  In general formula (3), Y and k are synonymous with those of general formula (2).

  Examples of the substituent represented by the general formula (3) include a sulfamoyl group, a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a hexylamino group, an octylamino group, a dodecylamino group, and an octadecylamino group. , Dimethylamino group, diethylamino group, dibutylamino group, dimethylaminopropylamino group, diethylaminopropylamino group, diethylaminoethylamino group, dibutylaminopropylamino group, piperidinomethyl group, dimethylaminomethyl group, diethylaminomethyl group, dibutylaminomethyl group Dimethylaminoethyloxy group, dimethylaminoethylthio group, diethylaminoethylthio group, diethylaminoethylsulfinyl group, (4,6-bis (diethylaminopropylamino) -1,3,5-tria ) -2-yl group, dimethylaminopropylaminosulfonyl group, diethylaminopropylaminosulfonyl group, dibutylaminopropylaminosulfonyl group, morpholinoethylaminosulfonyl group, 4-aminophenylaminosulfonyl group, piperidinopropylaminosulfonyl group, 4-methylpiperazinopropylaminosulfonyl group, dimethylaminopropylaminocarbonyl group, 4- (diethylaminopropylaminocarbonyl) phenylaminocarbonyl group, dimethylaminomethylcarbonylaminomethyl group, diethylaminopropylaminomethylcarbonylaminomethyl group, dibutylamino Examples thereof include a propylaminomethylcarbonylaminomethyl group.

  In general formula (4), Y and k are synonymous with those of general formula (2).

  Examples of the substituent represented by the general formula (4) include a sulfo group, a sodium sulfonate group, a calcium sulfonate group, a strontium sulfonate group, a barium sulfonate group, an aluminum sulfonate group, and 4- (aluminum sulfonate group). ) Phenylcarbamoylmethyl group, dodecylammoniosulfonato group, octadecylammoniosulfonato group, trimethyloctadecylammoniosulfonato group, dimethyldidecylammoniosulfonato group, carboxyl group, 2-ammoniumcarboxylato-5-nitrobenzamide A methyl group, 4-carboxyphenylaminocarbonyl group, etc. are mentioned.

  Specific examples of the benzimidazolone dioxazine pigment dispersant represented by the general formula (1) are shown below.

  Next, the pigment composition of the present invention will be described. The pigment composition of the present invention contains a pigment and the benzimidazolone dioxazine pigment dispersant of the present invention.

  As the pigment contained in the pigment composition of the present invention, various commercially available organic or inorganic pigments can be used. Examples of organic pigments include azo, anthanthrone, anthrapyrimidine, anthraquinone, isoindolinone, isoindoline, indanthrone, quinacridone, quinophthalone, dioxazine, diketopyrrolopyrrole, Organic pigments such as thiazine indigo, thioindigo, pyranthrone, phthalocyanine, flavanthrone, perinone, perylene, benzimidazolone and the like can be mentioned. Examples of the inorganic pigment include carbon black, titanium oxide, yellow lead, cadmium yellow, cadmium red, dial, iron black, zinc white, bitumen, and ultramarine blue. These pigments may be used in combination.

  Among the pigments, the non-aggregation property, the non-crystallinity, the fluidity and the like are great for the pigment having the same or similar chemical structure as the benzimidazolone dioxazine pigment dispersant of the present invention. In terms of hue, it is preferably used for purple to blue pigments. In particular, since the pigment dispersant of the present invention exhibits an excellent dispersion effect while maintaining the color of the pigment itself and maintaining high sharpness, it can be used for dioxazine-based purple pigments and phthalocyanine-based blue pigments. preferable.

  When the pigment composition of the present invention is mechanically kneaded with a mixture of a pigment and a benzimidazolone dioxazine pigment dispersant in the presence of a water-soluble inorganic salt or a water-soluble inorganic salt and a solvent, pigment crystal growth prevention and particle stabilization Due to the property effect, fine and sized particles can be easily obtained. As a kneading machine used at this time, a kneader, a two-roll mill, a three-roll mill, a ball mill, an attritor, a sand mill, or the like can be used, but is not limited thereto. Further, coarse pigments may be used as the pigment. The ratio of pigment to benzimidazolone dioxazine pigment dispersant is preferably 0.1 to 30 parts by weight of benzimidazolone dioxazine pigment dispersant with respect to 100 parts by weight of pigment, and 0.5 to 25 parts by weight. More preferred.

  Examples of water-soluble inorganic salts used for mechanical kneading include, but are not limited to, sodium chloride, potassium chloride, mirabilite, and the like. The water-soluble inorganic salt is preferably used in an amount of 100 to 2000 parts by weight, more preferably 300 to 1000 parts by weight, based on 100 parts by weight of the pigment. Further, the solvent used for mechanical kneading is not particularly limited, but a solvent having a high boiling point is preferable from the viewpoint of safety because the temperature rises during the kneading and the solvent is easily evaporated. Examples include 2- (methoxymethoxy) ethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tri Ethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, low molecular weight polypropylene A glycol etc. can be mentioned. The solvent is preferably used in an amount of 10 to 1000 parts by weight, and most preferably 50 to 500 parts by weight, based on 100 parts by weight of the pigment.

  Further, among the benzimidazolone dioxazine pigment dispersants represented by the general formula (1), those having a basic group or an acidic group can have a viscosity reducing effect even when added at the time of refining pigment particles. When these benzimidazolone dioxazine pigment dispersants are added to a finer pigment and mixed with powder later, higher effects can be obtained. Furthermore, in order to effectively reduce the viscosity, a benzimidazolone dioxazine pigment dispersant having a basic group or an acidic group can be dissolved in a dissolver, a high speed mixer, a homomixer, a kneader, a roll mill, an attritor, a sand mill, various grinding machines. Or the like, or a solution containing the pigment dispersant of the present invention is added to the suspension system of the pigment with water or an organic solvent, and the pigment dispersant is deposited on the pigment surface, or strong dissolution of sulfuric acid or the like An example is a method in which an organic pigment and a pigment dispersant are co-dissolved in a powerful solvent and coprecipitated with a poor solvent such as water. The structure of the benzimidazolone dioxazine pigment dispersant added at the time of refining the pigment and that added after the refining may be different.

  In addition, the benzimidazolone dioxazine pigment dispersant contained in the pigment composition of the present invention has a wide structure, crystal growth, particle stability effect, and viscosity reduction effect, particularly dioxazine purple pigments and phthalocyanine blue pigments Thus, a high effect can be obtained.

Next, the coloring composition using the pigment composition of this invention is demonstrated.
The coloring composition contains the pigment composition of the present invention and a pigment carrier.
The pigment carrier is constituted by a resin, its precursor or a mixture thereof. When a color filter is produced using a colored composition, it is preferable to use a transparent resin having a transmittance of 80% or more, particularly 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region.
Examples of the resin include thermoplastic resins, thermosetting resins, and photosensitive resins. Examples of the resin precursor include monomers or oligomers that are cured by irradiation with radiation to form a resin, and these can be used alone or in combination of two or more.

  The pigment carrier can be used in an amount of 30 to 700 parts by weight, preferably 60 to 450 parts by weight, with respect to 100 parts by weight of the pigment composition in the coloring composition. When a mixture of a resin and its precursor is used as a pigment carrier, the resin is 20 to 400 parts by weight, preferably 50 to 250 parts by weight with respect to 100 parts by weight of the pigment composition in the colored composition. Can be used. The resin precursor can be used in an amount of 10 to 300 parts by weight, preferably 10 to 200 parts by weight, with respect to 100 parts by weight of the pigment composition in the colored composition.

Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. , Acrylic resins, alkyd resins, polystyrene, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polyethylene, polybutadiene, polyimide resins, and the like.
Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenol resins.

  Photosensitive resins include (meth) acrylic compounds and silicate polymers having reactive substituents such as isocyanate groups, aldehyde groups, and epoxy groups on polymers having reactive substituents such as hydroxyl groups, carboxyl groups, and amino groups. A resin obtained by reacting an acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the polymer is used. Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is converted into a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

  As monomers and oligomers that are precursors of resins, methyl (meth) acrylate, ethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, β- Carboxyethyl (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, triethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, trimethylolpropane tri ( (Meth) acrylate, pentaerythritol tri (meth) acrylate, 1,6-hexanediol diglycidyl ether di (meth) acrylate, bisphenol A diglycidyl ether di (meth) Acrylate, neopentyl glycol diglycidyl ether di (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, ester acrylate, (meth) acrylic acid ester of methylolated melamine, epoxy (meth) Various acrylates and methacrylates such as acrylate and urethane acrylate, (meth) acrylic acid, styrene, vinyl acetate, hydroxyethyl vinyl ether, ethylene glycol divinyl ether, pentaerythritol trivinyl ether, (meth) acrylamide, N-hydroxymethyl ( Examples include meth) acrylamide, N-vinylformamide, acrylonitrile and the like.

  In order to improve the dispersibility of the pigment in the pigment carrier, the coloring composition may appropriately contain a dispersion aid such as a surfactant and a resin-type pigment dispersant. The dispersion aid can be used in an amount of 0.1 to 40 parts by weight, preferably 0.1 to 30 parts by weight, with respect to 100 parts by weight of the pigment composition in the coloring composition.

  Surfactants include polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, sodium alkylnaphthalenesulfonate, sodium alkyldiphenyletherdisulfonate, lauryl sulfate monoethanolamine, lauryl Anionic surfactants such as triethanolamine sulfate, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate; Polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Nonionic surfactants such as alkyl ether phosphates, polyoxyethylene sorbitan monostearate, and polyethylene glycol monolaurate; chaotic surfactants such as alkyl quaternary ammonium salts and their ethylene oxide adducts; alkyldimethylamino Examples include amphoteric surfactants such as alkylbetaines such as betaine acetate and alkylimidazolines, and fluorine-based and silicone-based surfactants.

  Resin-type pigment dispersant is a resin that has a pigment-affinity part that has the property of adsorbing to the pigment and a part that is compatible with the pigment carrier, and adsorbs to the pigment to stabilize the dispersion of the pigment on the pigment carrier. It works to do. Examples of the resin-type pigment dispersant include those made of a polyester-based, acrylic-based, or urethane-based linear or comb-like resin. The main chain or terminal of the linear resin, the main chain or side of the comb-shaped resin, and the like. Those having a basic group, acidic group, aromatic group or the like in the chain in a block or randomly are preferable.

  Examples of commercially available resin-type pigment dispersants include, for example, Polyflow No. 75, No. 90, No. 95 (manufactured by Kyoeisha Yushi Chemical Co., Ltd.), Megafac F171, F172, F173 (manufactured by Dainippon Ink and Chemicals), Florard Fc430 , Fc431 (manufactured by Sumitomo 3M), Solsperse 13240, 20000, 24000, 26000, 28000, etc. Dispersic Dispersants (made by Big Chemie) Etc.).

When the coloring composition is cured by irradiation with light such as ultraviolet rays, a photopolymerization initiator is added.
Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Acetophenone photopolymerization initiators such as hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl Benzoin photopolymerization initiators such as ether and benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzene Benzophenone photopolymerization initiators such as zoyl-4′-methyldiphenyl sulfide, thioxanthone light such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone Polymerization initiator, 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4,6-bis (trichloro) Methyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s-triazine, 2,4 -Bis (trichloromethyl) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis ( Lichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, Triazine photopolymerization initiators such as 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, borate photopolymerization initiators, carbazole photopolymerization initiators, imidazole photopolymerization initiators, and the like are used. . A photoinitiator can be used in the amount of 5-200 weight part with respect to 100 weight part of pigment compositions in a coloring composition, Preferably it is 10-150 weight part.

  The above photopolymerization initiators can be used alone or in combination of two or more. As the sensitizer, α-acyloxime ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10- Phenanthrenequinone, camphorquinone, ethylanthraquinone, 4,4'-diethylisophthalophenone, 3,3 ', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, 4,4'-diethylaminobenzophenone These compounds can also be used in combination. The sensitizer can be used in an amount of 0.1 to 60 parts by weight with respect to 100 parts by weight of the photopolymerization initiator in the colored composition.

The coloring composition may contain a solvent in order to sufficiently disperse the pigment in the pigment carrier and to easily form a uniform coating film. Examples of the solvent include cyclohexanone, propylene glycol diacetate, propylene glycol monomethyl ether, diethylene glycol diethyl ether, methyl isobutyl ketone, n-butyl alcohol, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol monopropyl ether, dipropylene. Glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol monobutyl ether, tripropylene glycol monomethyl ether, propylene glycol phenyl ether, dipropylene glycol monomethyl ether acetate, 1,3-butylene glycol diacetate, ethylene glycol monobutyl ether, Lenglycol monobutyl ether acetate, diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, 3-methoxybutanol, 1,3-butylene glycol, triacetin, 3,3,5-trimethyl-2-cyclohexen-1-one, ethylene glycol monoethyl ether , Γ-butyrolactone, isoamyl acetate, ethyl 3-ethoxypropionate, propylene glycol monomethyl ether acetate, toluene, o-xylene, m-xylene, p-xylene, methyl 3-methoxypropionate, butyl acetate, isobutyl acetate, propyl acetate Etc. These solvents can be used alone or in combination.
The solvent can be used in a total amount of 800 to 4000 parts by weight, preferably 1000 to 2500 parts by weight, based on 100 parts by weight of the pigment composition in the coloring composition.

The coloring composition can contain a storage stabilizer in order to stabilize the viscosity with time of the composition. Moreover, in order to improve adhesiveness with a base material, adhesion improving agents, such as a silane coupling agent, can also be contained.
In addition, for the coloring composition, if necessary, a thermal polymerization inhibitor, a plasticizer, a surface protective agent, a smoothing agent, a coating aid, an adhesion improver, and a coatability improver, as long as the effects of the present invention are not impaired. Alternatively, additives such as a development improver can be added.

The coloring composition comprises a three-roll mill, a two-roll mill, a horizontal sand mill, a vertical sand mill in the pigment carrier and an organic solvent together with the dispersion aid and the photopolymerization initiator as necessary. Further, it can be produced by finely dispersing using various dispersing means such as an annular bead mill, a kneader, and an attritor. In addition, the coloring composition containing two or more kinds of pigments may be produced by mixing finely dispersed pigments and organic solvents separately using a benzimidazolone dioxazine pigment dispersant for each pigment. it can.
The coloring composition may be dispersed after mixing all the components constituting the coloring composition. First, the pigment and benzimidazolone dioxazine pigment dispersant are dispersed in a part of the resin and / or organic solvent. Then, it is preferable to add and disperse the remaining components.

  In addition, a pigment dispersant other than benzimidazolone dioxazine can be used as necessary. Before dispersing with a horizontal sand mill, vertical sand mill, annular bead mill, attritor, etc., pre-dispersion using a kneader, three-roll mill, etc., solid dispersion with a two-roll mill, etc. The treatment of the benzimidazolone dioxazine pigment dispersant and the pigment dispersant other than benzimidazolone dioxazine may be performed simultaneously or separately. In addition, after being dispersed by a bead mill or the like, a post-treatment called aging which is stored at a temperature of 30 to 80 ° C. for several hours to one week, or a post-treatment using an ultrasonic disperser or a collision type beadless disperser is performed. When done, it is effective for the stability of the colored composition. In addition, any disperser or mixer such as a microfluidizer, high-speed mixer, homomixer, ball mill, roll mill, stone mill, or ultrasonic disperser can be used to produce the colored composition.

  When the colored composition is used for the production of a color filter, it is coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably 0. It is preferable to remove coarse particles of 5 μm or more and mixed dust.

  The coloring composition can be prepared as gravure offset printing ink, waterless offset printing ink, silk screen printing ink, solvent development type or alkali development type colored resist material.

  The solvent development type or alkali development type colored resist material contains a thermoplastic resin, thermosetting resin or photosensitive resin as a pigment carrier, a monomer, a photopolymerization initiator, and a solvent. The pigment composition of the invention is dispersed.

  Furthermore, the coloring composition is excellent in dispersion effect and stability over time even in the coloring of a wide range of printing inks, paints, inkjet inks, and plastics, and a colored product having coloring power can be obtained.

  In that case, without using a monomer or photopolymerization initiator, in addition to the resin and solvent described above, resins such as petroleum resin, casein, shellac, drying oil, synthetic drying oil, and ethyl cellosolve acetate, butyl cello buacetate, ethylbenzene , Ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol, glycerin, dimethylformamide, Solvesso 100 (Exxon Chemical Co., Ltd.), Swazol 1000, petroleum-based solvents, etc. A colored composition can be produced by the above-described method using a resin-type pigment dispersant.

  Hereinafter, the present invention will be described with reference to synthesis examples of pigment dispersants and examples using the same, but the present invention is not limited thereto. In addition, unless otherwise indicated in a sentence, a part represents a weight part and% represents weight%.

Synthesis Example 1 Synthesis Method of Intermediate (Compound (1)) In 300 parts of 30% fuming sulfuric acid, C.I. I. 30 parts of Pigment Blue 80 (“Hostaperm Blue R5R VP 2548” manufactured by Clariant) was charged at room temperature, stirred at 120 ° C. for 4 hours, and then added dropwise to 2700 parts of methyl ethyl ketone (MEK) over 15 minutes. The precipitated product was filtered, washed with 3000 parts MEK and dried at 80 ° C. This gave 45 parts of compound (1).

Synthesis Example 2 Synthesis Method of Pigment Dispersant A (Compound (2)) In 300 parts of chlorosulfonic acid, 30 parts of Compound (1) was charged at room temperature. After stirring at room temperature for 7 hours, the mixture was added dropwise to 1500 parts of ice water over 15 minutes. The precipitated sulfonyl chloride was filtered and washed with 3000 parts of ice water to obtain a press cake. In a 3 L beaker, 500 parts of ice, 500 parts of water and 50 parts of diethylaminoethylamine were added, and a sulfonyl chloride presscake was added at 2 to 5 ° C. The mixture was then warmed to 60 ° C. and stirred for 90 minutes. The product was filtered, washed with water and dried at 80 ° C. This obtained 43 parts of pigment dispersant A (compound (2)).

Synthesis Example 3 Synthesis Method of Pigment Dispersant B (Compound (3)) 30 parts of Compound (1) was charged at room temperature into a mixed solution of 150 parts of methanol and 600 parts of distilled water. After stirring at room temperature for 1 hour, 45 parts of an aqueous aluminum sulfate solution (8% as alumina) was added dropwise over 20 minutes, followed by stirring at 80 degrees for 2 hours. After the reaction solution was cooled to room temperature, the product was filtered, washed with water, and dried at 80 degrees. This obtained 33 parts of pigment dispersant B (compound (3)).

Synthesis Example 4 Synthesis Method of Intermediate (Compound (4)) In 300 parts of 30% fuming sulfuric acid cooled to 0 ° C., C.I. I. 30 parts of Pigment Blue 80 (“Hostaperm Blue R5R VP 2548” manufactured by Clariant) was slowly added dropwise over 30 minutes while maintaining the temperature at 20 ° C. or lower. Furthermore, after adding 25 parts of α-chloroacetamide over 20 minutes, 9 parts of paraformaldehyde was added over 20 minutes, stirred at 15 to 20 ° C. for 4 hours, and left overnight. The reaction solution was poured into 750 parts of ice and 1500 parts of water, and the precipitate was filtered, washed with 1000 parts of ice water, and dried at 80 ° C. This gave 41 parts of compound (4).

(Synthesis Example 5) Synthesis Method of Pigment Dispersant C (Compound (5)) Into a 3 L beaker, 500 parts of ice, 500 parts of water, and 50 parts of 1- (2-aminoethyl) piperazine were added. At 5 ° C., 30 parts of compound (4) was added. The mixture was then warmed to 60 ° C. and stirred for 2 hours. The product was filtered, washed with water and dried at 80 ° C. This gave 47 parts of pigment dispersant C (compound (5)).

Synthesis Example 6 Synthesis Method of Pigment Dispersant D (Compound (6)) I. 30 parts of Pigment Blue 80 (“Hostaperm Blue R5R VP 2548” manufactured by Clariant) was dissolved in 100 parts of 30% fuming sulfuric acid and 210 parts of chlorosulfonic acid, added with 45 parts of paraformaldehyde, and stirred at 45 ° C. for 1 hour. Thereto, 30 parts of diethylamine was added dropwise over 15 minutes, and the mixture was further stirred for 2 hours. The reaction solution was poured into 750 parts of ice and 1500 parts of water, and the precipitate was filtered, washed with 1000 parts of ice water, and dried at 80 ° C. This obtained 38 parts of pigment dispersant D (compound (6)).

Synthesis Example 7 Synthesis Method of Pigment Dispersant E (Compound (7)) I. 30 parts of Pigment Blue 80 (“Hostaperm Blue R5R VP 2548” manufactured by Clariant) was added to 100 parts of 30% fuming sulfuric acid, and 19 parts of n-hydroxyphthalimide was gradually added while keeping the temperature at 10 ° C. or lower. After stirring for a period of time, the temperature was raised to 60 ° C. and reacted for 2 hours. The reaction mixture was poured into 750 parts of water, filtered, washed with water, and dried at 80 ° C. This obtained 38 parts of pigment dispersant E (compound (7)).

Example 1 Dioxazine-based purple pigment C.I. I. Pigment Violet 23 (Clariant “Fast Violet RL”) 95 parts, Pigment Dispersant A 5 parts, Sodium Chloride 450 parts, Diethylene Glycol 100 parts are charged into a 1000-volume part double-armed kneader and dense lump at 80 ° C. While being held in (dough), it was refined by a solvent salt milling method for 6 hours. The pigment was taken out in water at 70 ° C., stirred for 1 hour, filtered and washed with water, after removing sodium chloride and diethylene glycol, dried and pulverized at 80 ° C. to obtain a pigment composition.

Example 2 A pigment composition was obtained in the same manner as in Example 1 except that the pigment dispersant B was used instead of the pigment dispersant A.

(Example 3) 90 parts of a dioxazine-based purple pigment similar to Example 1, 10 parts of Pigment Dispersant C, 450 parts of sodium chloride, and 100 parts of diethylene glycol were charged into a 1000-volume part double-arm kneader. Similarly, the pigment composition was obtained by refining by the solvent salt milling method.

(Example 4) A pigment composition was obtained in the same manner as in Example 3 except that instead of pigment dispersant C, pigment dispersant D was used.

(Example 5) A pigment composition was obtained in the same manner as in Example 3 except that instead of pigment dispersant C, pigment dispersant E was used.

(Example 6) A phthalocyanine blue pigment C.I. I. A pigment composition was obtained in the same manner as in Example 1 except that CI Pigment Blue 15: 6 (“LIONOL BLUE ES” manufactured by Toyo Ink Manufacturing Co., Ltd.) was used.

(Example 7) 92 parts of the same phthalocyanine blue pigment and pigment dispersant C as in Example 6, 8 parts of sodium chloride, 450 parts of sodium chloride and 100 parts of diethylene glycol were charged into a 1000-volume part double-arm kneader. In the same manner, it was refined by a solvent salt milling method to obtain a pigment composition.

(Comparative Example 1) 100 parts of dioxazine-based violet pigment, 450 parts of sodium chloride and 100 parts of diethylene glycol as in Example 1 were charged into a 1000-volume part double-arm kneader and subjected to the solvent salt milling method in the same manner as in Example 1. The pigment composition was obtained by refining.

(Comparative Example 2) A pigment composition was obtained in the same manner as in Comparative Example 1 except that the solvent salt milling time was extended from 6 hours to 9 hours.

(Comparative Example 3) A pigment composition was obtained in the same manner as in Comparative Example 1 except that the same phthalocyanine blue pigment as in Example 6 was used instead of the dioxazine-based purple pigment.

  The pigment compositions obtained in Examples 1 to 7 and Comparative Examples 1 to 3 were observed with an electron microscope, and the average particle size and the variation range of the particle size were determined. The results are summarized in Table 2.

  When using a benzimidazolone dioxazine pigment dispersant to make the pigment finer, the fineness of the particle size distribution is easily reduced due to its crystallinity prevention effect and particle stability effect. It became a pigment composition that can be suitably used in the required field

Preparation of Acrylic Resin Solution 800 parts of cyclohexanone was added to a four-necked flask equipped with a thermometer, a cooling tube, a nitrogen gas introduction tube, and a stirring device, and heated to 100 ° C. under nitrogen gas injection. At this temperature, a mixture of 60 parts of methacrylic acid, 65 parts of methyl methacrylate, 65 parts of butyl methacrylate, 60 parts of 2-hydroxyethyl methacrylate and 10 parts of 2,2′-azobisisobutyronitrile is dropped over about 1 hour. Then, a polymerization reaction was performed. After completion of the dropwise addition, the mixture was further stirred for 3 hours, a solution in which 2 parts of 2,2′-azobisisobutyronitrile was dissolved in 50 parts of cyclohexanone was added, and the reaction was further continued at 80 ° C. for 1 hour to obtain a weight average molecular weight. Obtained an acrylic resin solution of about 40,000.
After cooling to room temperature, about 2 parts of the resin solution was sampled, dried by heating at 180 ° C. for 20 minutes to measure the nonvolatile content, and cyclohexane was added to the previously synthesized resin solution so that the nonvolatile content was 20%. To prepare an acrylic resin solution.

Examples 8 to 16 and Comparative Examples 4 to 7
Various pigment compositions or pigments and benzimidazolone dioxazine pigment dispersant, the acrylic resin solution shown above, cyclohexanone as a solvent, and, if necessary, an additive (40% anone solution of “Ajisper PB821” manufactured by Ajinomoto Fine Chemical Co., Ltd.) Each of them was weighed in a 140 ml screw cap bottle with the blending amount shown in Table 4. 150 g of zirconia beads having a diameter of 1.25 mm were added and dispersed for 8 hours with a paint conditioner to obtain a colored composition.

The viscosity and thixotropic index (TI value) of the pigment dispersion thus obtained were measured with a B-type viscometer. Further, after the pigment dispersion was stored at 40 ° C. for one week, the viscosity was measured again, and the result of the viscosity increase rate was evaluated according to the following three-stage criteria.
A: Almost no increase in viscosity is observed. O: A slight increase in viscosity is observed, but is in a usable range.

  The evaluation results are collectively shown in Table 3.

  As shown in Table 3, it is understood that those using the pigment dispersant of the present invention have a low viscosity, a small TI value, and excellent fluidity. Furthermore, the viscosity stability over time showed good results.

Claims (4)

A benzimidazolone dioxazine pigment dispersant represented by the following formula (1).

(In the formula, R ¹ and R ² each independently represent a hydrogen atom, a halogen atom, or a group represented by the following general formula (2).
R ^{3 to} R ⁶ each independently represent a hydrogen atom or an alkyl group.
R ^{7 to} R ¹⁰ each independently represent a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkoxy group, a nitro group, an amino group, a sulfonic acid group, a carboxylic acid group, or the following general formula (2). Represents a group.
Provided that at 1-6 of ^{R 1, R 2, R 7} ~R 10 is a group represented by the following general formula (2). )

(In general formula (2),
Y represents —R ²¹ —, —CONR ¹¹ —R ²¹ —, —NR ¹¹ —R ²¹ —, —NR ¹¹ CO—R ²¹ —, —NR ¹¹ SO ₂ —R ²¹ —, —O—R ²¹ —, It represents —S (O) _m —R ²¹ —, —SO ₂ NR ¹¹ —R ²¹ —, a triazine residue, or a linking group in which two or more of these are bonded.
Z represents ^{-COO · M, -NR 12 R 13} , phthalimide group, -SO ₃ · M, the -SO ₂ NR ¹² R ^13.
R ¹¹ represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group.
R ¹² and R ¹³ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, a hydroxyalkyl group, a halogen atom-substituted alkyl group, or an optionally substituted aminoalkyl group. Alternatively, R ¹² and R ¹³ may be combined to form a ring.
R ²¹ represents a direct bond, a linear or branched alkylene group having 1 to 12 carbon atoms, an arylene group, or a divalent triazine residue.
m represents an integer of 0 to 3.
k is 2 when Y contains an alkylene group, an arylene group or a triazine residue, and 1 otherwise.
M represents a hydrogen ion, a 1-3 valent metal ion, or an ammonium ion at least one of which is substituted with an alkyl group. )   A pigment composition comprising a pigment and the pigment dispersant according to claim 1.   The pigment composition according to claim 2, wherein the pigment contains a dioxazine pigment and / or a phthalocyanine pigment.   Dioxazine pigments are C.I. I. Pigment Yellow 23 and phthalocyanine pigments are C.I. I. The pigment composition according to claim 3, which is CI Pigment Blue 15: 6.