JP2007009096A - Pigment composition and pigment dispersion using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment dispersion not only being excellent in nonaggregating property, noncrystallinity, and in gloss and transparency of a coating film, but also being easily dispersed and satisfactory in low viscosity and low thixotropy and aged viscosity stability, in a fine pigment dispersing system. <P>SOLUTION: This pigment composition comprises at least one pigment dispersant selected from the group consisting of an organic pigment derivative containing an amino group, a sulfo group or a carboxy group, an anthraquinone derivative and a triazine derivative, and a pigment in which particles having a 100 nm or more primary particle size preferably do not account for more than 20 wt% in the total pigment particles. In the pigment composition, the size of a ground particle when a volume cumulative particle amount of the pigment dispersant reaches 90% is ≤30 μm. The pigment dispersion is produced by dispersing the pigment composition in a nonaqueous or an aqueous vehicle. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a pigment composition that enables fine dispersion of pigment particles and a pigment dispersion using the same, and more specifically, offset ink, paint, resin colorant, inkjet ink, and ink for color filters. The present invention relates to a pigment composition and a pigment dispersion that are suitably used for the above.

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. Furthermore, many offset inks, gravure inks, paints, particularly inkjet inks, color filter inks, and the like contain highly fine pigment particles in order to obtain high sharpness (see Patent Document 1).
However, when the pigment is made finer, the cohesive force between the pigment particles becomes stronger, and the ink or paint often has a 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 addition, when different types of pigments are mixed and used, phenomena such as color separation and sedimentation due to aggregation of the pigments may cause uneven color and a marked decrease in coloring power in the developed product. 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.

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 have been developed in which an organic pigment is used as a base skeleton and a functional group such as an acidic group, a basic group, or a phthalimidomethyl group is introduced into the side chain.
Among these, pigment derivatives having an acidic group such as a sulfo group or a carboxyl group have been used as dispersants and particle growth inhibitors for a long time, mainly phthalocyanine pigments and quinacridone pigments. Azo pigments and anthraquinone pigments , Diketopyrrolopyrrole pigments, isoindoline pigments, and other various pigments (see Patent Document 2).
Similarly, pigment derivatives having a basic group have been used as a dispersant for a long time and have been reported to show good results in fluidity, stability over time, etc., and have been reported to be phthalocyanine pigments, quinacridone pigments, azo pigments, anthraquinones. It has been developed to various pigments such as pigments based on pigments, diketopyrrolopyrrole pigments, and isoindoline pigments (see Patent Document 3).

In addition to these, it has been reported that derivatives having a triazine ring also show good results in the fluidity and stability over time of the pigment dispersion (see Patent Document 4).
However, these polar derivatives, especially strong polar derivatives, often cause strong dry aggregation in the production process.
On the other hand, the particle size of pigments and pigment dispersants has not been elucidated in systems with relatively low solid content, such as gravure inks and flexographic inks, but with low viscosity pigment dispersions and not so fine dispersions. The coarsely pulverized pigment composition in which particles of 0.175 to 5 mm are substantially controlled to 40% by weight or more is easier to disperse, resulting in a low viscosity and high gloss ink. It is known (see Patent Document 5). However, high-viscosity pigment dispersions with a high solid content such as offset ink and resin colorant are not effective or rather counterproductive.

  Moreover, in highly fine pigment dispersions, derivatives that cause strong dry aggregation are not easy to disperse, so the effects of the dispersant can be reduced by slight changes in the preparation of materials and dispersion conditions. In addition, the dispersion as a dispersing agent is not obtained, and the drying aggregation is much stronger than that of the pigment. This may lead to problems such as impairing the smoothness of the image and causing printing troubles. In particular, in a pigment dispersion using a fine pigment in which pigment particles having a primary particle diameter of 100 nm or more are 20% by weight or less of the total pigment particles, the dispersant does not function and the ink becomes a gel-like. Highly refined pigment dispersions such as inkjet inks and color filter inks cannot stably supply pigment dispersions that have high transparency, low viscosity, and good temporal stability. Have a problem.

As a means to solve this problem, coating the derivative particles with various rosin, rosin ester, maleic acid resin, etc., or heat treatment in xylene emulsion at high temperature for a long time, etc., alleviates dry aggregation and improves dispersibility. There are known methods for increasing the viscosity, and a method in which a water cake of a derivative is directly fed into a dispersion such as ink or paint without passing through a drying step to eliminate the problem of dry aggregation. However, a coating agent such as rosin that has been treated for the purpose of suppressing dry aggregation prevents the pigment dispersant from adsorbing to the target pigment particles, and provides fluidity, dispersion stability, and gloss of the dried film when used as an ink. May be adversely affected. Especially when used in applications that need to be dispersed in the form of ultrafine particles such as inkjet inks and color filter inks, problems such as poor dispersion stability of the dispersion itself, dry film, and poor printed material durability. Therefore, it is desired to eliminate additives corresponding to such foreign substances as much as possible.
Even in the case of using a water cake, it is not preferable that water is mixed in a non-aqueous vehicle, so the range of use is limited. Therefore, the range of use is not limited, and an effective improvement measure that can be widely used for derivatives having any structure is desired.
JP 2004-244563 A JP 60-98525 A JP-A-3-26767 JP 11-199796 A JP-A-1-45475

The problem to be solved by the present invention is to maximize the dispersibility effect of a pigment dispersant selected from organic dye derivatives having an acidic or basic polarity substituent, anthraquinone derivatives and triazine derivatives, It is to provide a pigment composition that facilitates fine dispersion of the pigment.
Another problem to be solved by the present invention is low viscosity, stable with time, which is suitably used for systems that require fine dispersion of pigment particles such as offset inks and paints, particularly ink jet inks and color filter inks. It is to stably provide a pigment dispersion which is remarkably excellent in properties.

The pigment composition of the present invention is a pigment composition comprising at least one pigment dispersant selected from the group consisting of organic dye derivatives, anthraquinone derivatives and triazine derivatives having an amino group, a sulfo group or a carboxyl group, and a pigment. The pulverized particle diameter at which the volume cumulative particle amount of the pigment dispersant is 90% is 30 μm or less. In the pigment composition of the present invention, among the pigments in the above pigment composition, it is preferable that the pigment particles having a primary particle diameter of 100 nm or more are 20% by weight or less of the total pigment particles.
The pigment dispersion of the present invention is characterized in that the above pigment composition is dispersed in a non-aqueous or aqueous vehicle.

The pigment composition of the present invention is selected from the group consisting of organic dye derivatives, anthraquinone derivatives and triazine derivatives having an amino group, a sulfo group or a carboxyl group with a pulverized particle size of 30 μm or less with a volume cumulative particle amount of 90%. Therefore, by using the pigment composition of the present invention, fine dispersion is easily performed, and the viscosity and stability over time are not only excellent, but also the gloss and hue of the coating film are improved. An excellent pigment dispersion can be obtained.
In addition, the pigment dispersion of the present invention has a finely dispersed pigment, not only excellent in low viscosity and stability over time, but also excellent in gloss and hue of the coating film. Is suitably used for inkjet inks, color filter inks, and the like.

Hereinafter, the present invention will be described in detail.
The pigment composition of the present invention is a pigment composition comprising at least one pigment dispersant selected from the group consisting of organic dye derivatives, anthraquinone derivatives and triazine derivatives having an amino group, a sulfo group or a carboxyl group, and a pigment. The pulverized particle diameter at which the volume cumulative particle amount of the pigment dispersant is 90% is 30 μm or less.
Derivatives with polarity, especially derivatives with strong polarity, often cause strong dry aggregation and are not easily dispersed compared with pigment particles. Therefore, even if the pigment particles are sufficiently dispersed, aggregation of the pigment dispersant still occurs. There are many cases where it remains without being loosened. However, it is easy even for pigment dispersants that cause strong dry aggregation by controlling the particle size of the pigment dispersant so that the pulverized particle size at which the volume cumulative particle amount is 90% is 30 μm or less, and removing coarse particles. Dispersion becomes possible, and the dispersibility effect of the pigment dispersant can be maximized.

When the pulverized particle diameter at which the volume cumulative particle amount of the pigment dispersant exceeds 90 μm exceeds 30 μm, the proportion of particles exceeding 30 μm increases. Even if it is, it may not be enough, and even with slight changes such as the preparation of materials and dispersion conditions, the effect will vary, especially in highly fine pigment dispersions, especially noticeable and serious It becomes a problem.
In the present invention, the pulverized particle diameter at which the volume cumulative particle amount of the pigment dispersant is 90% is measured by a laser diffraction particle size distribution measuring device (for example, “SALD-2100” manufactured by Shimadzu Corporation), The particle size (90.0% D) is 90%.

The particle diameter of the pigment dispersant can be controlled by pulverizing the pigment dispersant.
As a device for pulverizing the pigment dispersant, a high-speed rotational impact shear type pulverizer represented by a pin mill, a hammer mill, and a turbo mill, which are usually used for dry pulverization of pigments, a ball mill or a vibration mill using the impact force of a medium. Or a jet mill. Among them, it is preferable to use a high-speed rotational impact shearing type pulverizer because a desired pulverized particle diameter can be easily obtained. In addition, it is possible to control the pulverized particle size of the pigment dispersant by controlling the conditions of the pulverizer such as the pulverization time (feed amount) and pulverization temperature. Depending on the rotation speed of the hammer portion and the mesh size of the screen, it is possible to fit within the range of the pulverized particle diameter of the present invention.

Furthermore, it is preferable to use a dry classifier to reliably remove coarse particles and to obtain a dispersant having a pulverized particle size range of the present invention. As the classifier, a commonly used classifier can be used, and examples thereof include a fluid type and an airflow type. Furthermore, in spray drying in which the drying and pulverization steps are performed at once, the desired pulverized particle diameter can also be obtained by controlling the feed amount of the pigment dispersant slurry, the pigment dispersant concentration, and the temperature of the atomizer part.
In addition, the pigment composition of the present invention not only pulverizes the pigment and the pigment dispersant separately and controls the particles, but also pulverizes them in a mixed form. In the finally obtained pigment composition, the pigment dispersion The object can also be achieved by controlling the pulverized particle diameter at which the volume cumulative particle amount of the agent is 90% to be 30 μm or less.

Of the pigment dispersants selected from the group consisting of organic dye derivatives, anthraquinone derivatives and triazine derivatives having an amino group, sulfo group or carboxyl group used in the present invention (hereinafter referred to as the pigment dispersant of the present invention), organic. Examples of the dye derivative include an organic dye derivative represented by the following general formula (1).
_{P- [X 1 - (Y 1} ) k] m (1)
(In the formula, P represents an organic dye residue. X ₁ is a direct bond, —O—, —S—, —CO—, —SO ₂ —, —NR ₁ —, —CONR ₁ —, —SO ₂ NR. _1- , —NR ₁ CO—, —NR ₁ SO ₂ — (wherein R ₁ represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group), a straight chain or branched chain having 1 to 12 carbon atoms An alkylene group, an alkyl group, an amino group, a nitro group, a hydroxyl group, an alkoxy group, a benzene residue or a triazine residue optionally substituted with a halogen atom, or a linking group obtained by combining two or more of these linking groups Y ₁ represents —NR ₂ R ₃ , —SO ₃ · M / n, or —COO · M / n, and R ₂ and R ₃ each independently represent a hydrogen atom or an optionally substituted alkyl group. An optionally substituted alkenyl group, substituted A phenyl group which may or R ₂ and R ₃ and a further nitrogen together, including the oxygen or sulfur atom, represent a heterocyclic ring which may be substituted, M is a hydrogen ion, monovalent to trivalent, A metal ion or an ammonium ion at least one of which is substituted with an alkyl group is represented, n represents a valence of M, k represents an integer of 1 or 2, and m represents an integer of 1 to 4.

  Among these, organic dye residues constituting the organic dye derivative include, for example, diketopyrrolopyrrole dyes, azo dyes such as azo, disazo and polyazo, phthalocyanine dyes, diaminodianthraquinone, anthrapyrimidine, flavantrons, Anthraquinone dyes such as anthanthrone, indanthrone, pyratron, violanthrone, quinacridone dyes, dioxazine dyes, perinone dyes, perylene dyes, thioindigo dyes, isoindoline dyes, isoindolinone dyes, quinophthalone dyes, Examples thereof include dye residues such as selenium dyes and metal complex dyes.

In addition, among the substituents [X _1- (Y ₁ ) k], those having an amino group at the end include, for example, a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a hexylamino group, and an octylamino group. Group, dodecylamino group, 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 (4,6-bis (diethylaminopropylamino) -1,3,5-triazin) -2-yl group, dimethylaminopropyl Aminosulfo Nyl group, diethylaminopropylaminosulfonyl group, dibutylaminopropylaminosulfonyl group, morpholinoethylaminosulfonyl group, 4-aminophenylaminosulfonyl group, dimethylaminopropylaminocarbonyl group, 4- (diethylaminopropylaminocarbonyl) phenylaminocarbonyl group, Examples include dimethylaminomethylcarbonylaminomethyl group, diethylaminopropylaminomethylcarbonylaminomethyl group, dibutylaminopropylaminomethylcarbonylaminomethyl group, and the like.

Examples of those having a terminal sulfo group 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 a 4- (aluminum sulfonate group) phenylcarbamoylmethyl group. , Dodecyl ammonio sulfonate groups, octadecyl ammonio sulfonate groups, trimethyl octadecyl ammonio sulfonate groups, dimethyl didecyl ammonio sulfonate groups, and the like.
Examples of the terminal having a carboxyl group include a carboxyl group, a 2-ammoniumcarboxylato-5-nitrobenzamidomethyl group, and a 4-carboxyphenylaminocarbonyl group.

Among the pigment dispersants of the present invention, anthraquinone derivatives include anthraquinone derivatives represented by the following general formula (2).
_{Q- [X 2 - (Y 2} ) k] m (2)
(In the formula, Q represents an alkyl group, an amino group, a nitro group, a hydroxyl group, an alkoxy group, or an anthraquinone residue optionally substituted with a halogen atom. X ₂ represents a direct bond, —O—, —S—, —CO—, —SO ₂ —, —NR ₁ —, —CONR ₁ —, —SO ₂ NR ₁ —, —NR ₁ CO—, —NR ₁ SO ₂ — (wherein R ₁ is a hydrogen atom, an alkyl group) Represents a hydroxyalkyl group), a linear or branched alkylene group having 1 to 12 carbon atoms, and an alkyl group, an amino group, a nitro group, a hydroxyl group, an alkoxy group, or a halogen atom. A benzene residue or a triazine residue, or a linking group obtained by combining two or more of these linking groups, Y ₂ represents —NR ₂ R ₃ , —SO ₃ · M / n, or —COO · M / n. , R ₂ and R ₃ are each Standing a hydrogen atom, an optionally substituted alkyl group, an optionally substituted alkenyl group, an optionally substituted phenyl group or R ₂ and R ₃ and a further nitrogen together, oxygen or Represents an optionally substituted heterocyclic ring containing a sulfur atom, 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, and n represents the valence of M K represents an integer of 1 or 2, and m represents an integer of 1 to 4.)

The anthraquinone residue constituting the anthraquinone derivative may be substituted with an alkyl group such as a methyl group or an ethyl group, an amino group, a nitro group, a hydroxyl group or a methoxy group, an alkoxy group such as an ethoxy group, or a halogen atom such as chlorine. Residue.
Further, the substituent _{[X 2 - (Y 2)} k] of, as terminal amino groups, for example methylamino group, ethylamino group, propylamino group, butylamino group, hexylamino group, octyl amino group , Dodecylamino group, octadecylamino group, dimethylamino group, diethylamino group, dibutylamino group, dimethylaminopropylamino group, diethylaminopropylamino group, diethylaminoethylamino group, dibutylaminopropylamino group, piperidinomethyl group, dimethylaminomethyl group, Diethylaminomethyl group, dibutylaminomethyl group, (4,6-bis (diethylaminopropylamino) -1,3,5-triazin) -2-ylamino group, (4- (diethylaminopropylamino) -6-hydroxy-1, 3,5-triazine) -2- Ylamino group, dimethylaminopropylaminosulfonyl group, diethylaminopropylaminosulfonyl group, dibutylaminopropylaminosulfonyl group, morpholinoethylaminosulfonyl group, dimethylaminopropylaminocarbonyl group, 4- (diethylaminopropylaminocarbonyl) phenylaminocarbonyl group, dimethyl Examples include aminomethylcarbonylaminomethyl group, diethylaminopropylaminomethylcarbonylaminomethyl group, dibutylaminopropylaminomethylcarbonylaminomethyl group and the like.

Examples of those having a terminal sulfo group include a sulfo group, a sodium sulfonate group, a calcium sulfonate group, a strontium sulfonate group, a barium sulfonate group, an aluminum sulfonate group, a 4- (aluminum sulfonate group) phenylcarbamoylmethyl group, Examples include dodecyl ammonio sulfonate groups, octadecyl ammonio sulfonate groups, trimethyl octadecyl ammonio sulfonate groups, dimethyl didecyl ammonio sulfonate groups, and the like.
Examples of those having a carboxyl group at the end include a carboxyl group and a 4- (aluminum carboxylato) phenylaminocarbonyl group.

（式中、Ｒはトリアジン残基を表す。Ｘ₃からＸ₅はそれぞれ独立に直接結合、−Ｏ−、−Ｓ−、−ＣＯ−、−ＳＯ₂−、−ＮＲ₁−、−ＣＯＮＲ₁−、−ＳＯ₂ＮＲ₁−、−ＮＲ₁ＣＯ−、−ＮＲ₁ＳＯ₂−（ここでＲ₁は、水素原子、アルキル基、ヒドロキシアルキル基を表す）、炭素の数が１〜１２個の直鎖または枝分かれしたアルキレン基、およびアルキル基、ニトロ基、水酸基、アルコキシ基、またはハロゲン原子で置換されていてもよいベンゼン残基、またはこれらの結合基を２個以上組み合わせた結合基を表す。Ｙ₃は−ＮＲ₂Ｒ₃、−ＳＯ₃・Ｍ／ｎ、または−ＣＯＯ・Ｍ／ｎを表し、Ｒ₂とＲ₃はそれぞれ独立に水素原子、置換されていてもよいアルキル基、置換されていてもよいアルケニル基、置換されていてもよいフェニル基、またはＲ₂とＲ₃とで一体となって更なる窒素、酸素または硫黄原子を含む、置換されていてもよい複素環を表し、Ｍは水素イオン、１〜３価の金属イオンまたは少なくとも１つがアルキル基で置換されているアンモニウムイオンを表し、ｎはＭの価数を表す。Ｙ₄とＹ₅は、それぞれ独立にＹ₃と同じであるか、または、アルキル基、ニトロ基、水酸基、アルコキシ基、ハロゲン原子、またはメチル基、メトキシ基、水酸基等で置換されていてもよいフェニル基を表す。ｐ、ｑ、ｒは、それぞれ独立しており１または２の整数を表す。） Among the pigment dispersants of the present invention, triazine derivatives include triazine derivatives represented by the following general formula (3).

(In the formula, R represents a triazine residue. X ₃ to X ₅ are each independently a direct bond, —O—, —S—, —CO—, —SO ₂ —, —NR ₁ —, —CONR ₁ —. , —SO ₂ NR ₁ —, —NR ₁ CO—, —NR ₁ SO ₂ — (wherein R ₁ represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group), a straight chain having 1 to 12 carbon atoms. Y represents a chain or branched alkylene group, an alkyl group, a nitro group, a hydroxyl group, an alkoxy group, a benzene residue optionally substituted with a halogen atom, or a linking group obtained by combining two or more of these linking groups. ₃ represents —NR ₂ R ₃ , —SO ₃ · M / n, or —COO · M / n, and R ₂ and R ₃ each independently represent a hydrogen atom, an optionally substituted alkyl group, or a substituted group. Alkenyl group which may be substituted, phenyl which may be substituted Group or further nitrogen together with R ₂ and R _3, including an oxygen or sulfur atom, represent a heterocyclic ring which may be substituted, M is a hydrogen ion, monovalent to trivalent metal ions, or at least, One represents an ammonium ion substituted with an alkyl group, and n represents the valence of M. Y ₄ and Y ₅ are each independently the same as Y ₃ , or an alkyl group, a nitro group, and a hydroxyl group And an alkoxy group, a halogen atom, or a phenyl group which may be substituted with a methyl group, a methoxy group, a hydroxyl group, etc. p, q and r are each independently an integer of 1 or 2.

The triazine constituting the triazine derivative is 1,3,5-triazine.
Examples of the substituent having an amino group at the end include an amino group, methylamino group, ethylamino group, propylamino group, butylamino group, hexylamino group, octylamino group, dodecylamino group, octadecylamino group, dimethylamino group, Examples thereof include a diethylamino group, a dibutylamino group, a dimethylaminopropylamino group, a diethylaminopropylamino group, a diethylaminoethylamino group, a dibutylaminopropylamino group, a phenylamino group substituted with an amino group, or a phenoxy group. Examples of the substituent having an acidic terminal sulfo group or carboxyl group include an aluminum sulfonatoethylamino group, a 4-sulfophenylamino group, and a 4-carboxyphenylamino group.

The remaining substituents are substituted with a hydroxyl group or an alkoxy group such as a methoxy group, an ethoxy group, or a butoxy group, a halogen atom such as chlorine, or a methyl group, an ethyl group, a methoxy group, an ethoxy group, a nitro group, or a hydroxyl group. And a phenylamino group which may be substituted, a phenoxy group which may be substituted with a methyl group, an ethyl group, a methoxy group, an ethoxy group, a nitro group, a hydroxyl group and the like.
These organic dye derivatives represented by the general formula (1), anthraquinone derivatives represented by the general formula (2), and triazine derivatives represented by the general formula (3) are disclosed in, for example, Japanese Patent Publication No. 39-28884, Japanese Patent Publication No. 58-028303, JP-B 63-17101, JP-A 56-81371, JP-B 01-34268, JP-B 01-34269, JP-B 05-9396, JP 02 -62893 gazette, Japanese Patent Publication No. 07-33485 gazette, patent 2584515 gazette, patent 2906833 gazette, and patent 3518300 gazette, it can manufacture.
Specific examples of the organic dye derivative represented by the general formula (1), the anthraquinone derivative represented by the general formula (2), and the triazine derivative represented by the general formula (3) are shown below with compound numbers.

  0.1-30 weight part is preferable with respect to 100 weight part of pigments, and, as for the quantity of the pigment dispersant of this invention contained in a pigment composition, 1-20 weight part is more preferable. When the content of the pigment dispersant of the present invention is less than 0.1 parts by weight, it is difficult to obtain the effect of the added pigment dispersant, and when it is more than 30 parts by weight, the effect of the added amount is obtained. In addition, the difference between the physical properties of the obtained pigment composition and the physical properties of the pigment alone increases, and there may be problems in practical quality when used in inks and paints.

  As a 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 thioindigo, pyranthrone, phthalocyanine, flavanthrone, perinone, perylene, and benzimidazolone are listed. 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 them, 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 pigment dispersant of the present invention.

The pigments contained in the pigment composition of the present invention include those obtained by refining pigment particles at the synthesis stage, such as azo pigments, acid pasting methods or solvent salt milling using coarse pigments. Or a fine pigment in which pigment particles having a primary particle size of 100 nm or more are adjusted to 20% by weight or less of the total pigment particles. Preferably there is. At this time, an additive containing an organic solvent, a resin, a surfactant, or the like may be used as necessary at the stage of the synthesis of the pigment, the subsequent post-treatment process, or the refinement process such as pulverization. In addition to the pigment dispersant of the present invention, a pigment dispersant belonging to an organic dye derivative, anthraquinone derivative, or triazine derivative having a substituent such as an acidic or basic polarity or a phthalimidomethyl group is used. Also good. In this case, since a small amount of the pigment dispersant can uniformly treat the pigment particles, aggregation of the pigment dispersants is unlikely to occur, and those that have not been refined in advance can also be used.
In addition, the measurement of the primary particle of a pigment was performed by particle | grain observation by an electron micrograph.

The pigment composition of the present invention is dispersed in an aqueous or non-aqueous vehicle containing a resin, a solvent, and, if necessary, an additive such as a resin-type dispersant or a surfactant, a dispersant, and the like. Dispersions can be produced. Here, the water-based vehicle refers to a vehicle mainly composed of a water-soluble resin, a solvent, and water, and the non-water-based vehicle refers to a vehicle containing almost no other water. Examples of the disperser used at this time include a horizontal sand mill, a vertical sand mill, an annular bead mill, and an attritor. The pigment and all the components constituting the aqueous or non-aqueous vehicle may be mixed and then dispersed, but the pigment composition is first dispersed with a part of the resin and / or organic solvent, and then the remaining components It is desirable to add and disperse.
Further, 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, three roll mill, etc., solid dispersion with a two roll mill, etc., or pigment The pigment derivative may be treated. In addition, all dispersers and mixers such as a high speed mixer, a homomixer, a ball mill, a roll mill, a stone mill, and an ultrasonic disperser can be used for producing the dispersion of the present invention.

Examples of the resin in the aqueous or non-aqueous vehicle used in the pigment dispersion of the present invention include petroleum resin, casein, shellac, rosin modified maleic resin, rosin modified phenolic resin, nitrocellulose, cellulose acetate butyrate, cyclized rubber, Chloride rubber, oxide rubber, hydrochloric acid rubber, phenol resin, alkyd resin, polyester resin, unsaturated polyester resin, amino resin, epoxy resin, vinyl resin, vinyl chloride, vinyl chloride-vinyl acetate copolymer, acrylic resin, methacrylic resin, Polyurethane resin, silicone resin, fluorine resin, drying oil, synthetic drying oil, styrene / maleic acid resin, styrene / acrylic resin, polyamide resin, polyimide resin, benzoguanamine resin, melamine resin, urea resin chlorinated polypropylene, butyral resin, vinyl chloride Den resins.
A photosensitive resin can also be used as the non-aqueous vehicle. Examples of the photosensitive resin include (meth) acrylic compounds having a reactive substituent such as an isocyanate group, an aldehyde group, and an epoxy group on a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group, A resin obtained by reacting an acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the linear 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.

  Examples of the solvent in the aqueous or non-aqueous vehicle used in the pigment dispersion of the present invention include ethyl cellosolve acetate, butyl cellosolve acetate, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, toluene, xylene, and ethyl cellosolve. , Methyl-n amyl ketone, propylene glycol monomethyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, n-hexane, methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol, glycerin, dioxane, dimethylformamide, Solvesso 100 (Exxon Chemical Co., Ltd.), Swazol 1000, Oil-based solvents and the like, used alone or in combination.

  The aqueous or non-aqueous vehicle used in the pigment dispersion of the present invention may contain a resin type pigment dispersant. Examples of the resin-type pigment dispersant include those made of a polyester-based, acrylic-based, urethane-based linear or comb-like polymer copolymer, and the end of the linear polymer, the basic portion of the comb-shaped polymer, or It is preferable that both polymers contain a basic group, an acidic group, an aromatic group or the like in a block or randomly. Examples of such resin-type pigment dispersants include Solsperse 24000 (manufactured by Avicia), Disperbyk-160, Disperbyk-161, Disperbyk-162, Disperbyk-163, Disperbyk-170 (manufactured by BYK Chemie), etc., Azisper PB711, Ajisper PB821 (manufactured by Ajinomoto Fine Techno Co., Ltd.)

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to the range of these Examples. In the examples, “parts” represents parts by weight, and “%” represents% by weight.
In Examples, the particle diameter (90.0% D) at which the volume cumulative particle amount of the pigment dispersant is 90% was measured by a laser diffraction particle size distribution measuring device (“SALD-2100” manufactured by Shimadzu Corporation). .

Example 1
As an organic pigment, C.I. I. 50 parts of Pigment Blue 15 (“T-95 Crude Blue” manufactured by Zhuhai Toyo) and 2000 parts of 8 mmφ steel beads were placed in a dry attritor and pulverized at 300 rpm and 60 ° C. for 5 hours. When the obtained pigment (A) was observed with an electron microscope, it was confirmed that 80% or more of the primary particles had a particle diameter of 100 nm or less. As a pigment dispersant, the dried product of the compound (1) was charged into a continuous small hammer mill (“MF-10.2” manufactured by IKA Japan) equipped with a 0.5 mmφ screen and pulverized at 6000 rpm. After the pulverization, a pigment dispersant (1-1) was obtained through a sieve corresponding to 400 mesh. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 27.8 μm.
The pigment (A) and the pigment dispersant (1-1) were mixed at a ratio of 94% to 6% to obtain a pigment composition.

(Comparative Example 1)
As a pigment dispersant, the dried product of the compound (1) was charged into a continuous small hammer mill equipped with a 1.0 mmφ screen to obtain a pigment dispersant (1-2) pulverized at 3500 rpm. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 40.5 μm.
The pigment (A) obtained in the same manner as in Example 1 and the pigment dispersant (1-2) were mixed at a ratio of 94% to 6% to obtain a pigment composition.

(Comparative Example 2)
As a pigment dispersant, a pigment dispersant (1-3) obtained by pulverizing a dried product of the compound (1) with a cutter type sample mill (manufactured by SKM-1 Kyoritsu Riko Co., Ltd.) at 4000 rpm was obtained. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 58.7 μm.
The pigment (A) obtained in the same manner as in Example 1 and the pigment dispersant (1-3) were mixed at a ratio of 94% to 6% to obtain a pigment composition.

(Example 2)
As an organic pigment, C.I. I. Pigment Violet 23 (“Sumiton Fast Violet RL Base” manufactured by Sumitomo Chemical Co., Ltd.), 650 parts of sodium chloride, and 100 parts of diethylene glycol are charged into a 1000-volume part double-arm kneader and made into a dense lump at 80 ° C. While being held, it was refined by a solvent salt milling method for 15 hours. This pigment was taken out in water at 70 ° C., stirred for 1 hour, filtered and washed with water to remove sodium chloride and diethylene glycol, and then dried and pulverized at 80 ° C. When the obtained pigment (B) was observed with an electron microscope, it was confirmed that 80% or more of primary particles had a particle diameter of 100 nm or less. As a pigment dispersant, the dried product of the compound (4) was charged into a continuous small hammer mill equipped with a 0.5 mmφ screen and pulverized at 6000 rpm to obtain a pigment dispersant (4-1). The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 26.5 μm.
The pigment (B) and the pigment dispersant (4-1) were mixed at a ratio of 90% to 10% to obtain a pigment composition.

(Comparative Example 3)
As a pigment dispersant, a pigment dispersant (4-2) obtained by pulverizing a dried product of the compound (4) with a cutter type sample mill at 4000 rpm was obtained. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 56.0 μm.
The pigment (B) obtained in the same manner as in Example 2 and the pigment dispersant (4-2) were mixed at a ratio of 90% to 10% to obtain a pigment composition.

(Example 3)
As an organic pigment, C.I. I. Pigment RED254 (“Irgafore Red B-CF” manufactured by Ciba), 600 parts of sodium chloride, and 100 parts of diethylene glycol were charged into a 1000-capacity part double-arm kneader and held at 80 ° C. in a dense lump (dough). However, it refined | miniaturized by the solvent salt milling method for 12 hours. This pigment was taken out in water at 70 ° C., stirred for 1 hour, filtered and washed with water to remove sodium chloride and diethylene glycol, and then dried and pulverized at 80 ° C. When the obtained pigment (C) was observed with an electron microscope, it was confirmed that 80% or more of the primary particles had a particle diameter of 100 nm or less.
As a pigment dispersant, the dried compound (5) was charged into a continuous small hammer mill equipped with a 0.5 mmφ screen and pulverized at 6000 rpm. After the pulverization, a pigment dispersant (5-1) was obtained through a sieve corresponding to 400 mesh. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 24.8 μm.
The pigment (C) and the pigment dispersant (5-1) were mixed at a ratio of 92% to 8% to obtain a pigment composition.

(Comparative Example 4)
As a pigment dispersant, the dried product of the compound (5) was charged into a continuous small hammer mill equipped with a 3.0 mmφ screen to obtain a pigment dispersant (5-2) pulverized at 6000 rpm. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 43.8 μm.
The pigment (C) obtained in the same manner as in Example 3 and the pigment dispersant (5-2) were mixed at a ratio of 92% to 8% to obtain a pigment composition.

Example 4
As an organic pigment, C.I. I. 50 parts of Pigment RED177 (“Chromophthalred A2B” manufactured by Ciba) and 2000 parts of 8 mmφ steel beads were charged in a dry attritor and pulverized at a rotation speed of 300 rpm and 60 ° C. for 5 hours. When the obtained pigment (D) was observed with an electron microscope, it was confirmed that 80% or more of primary particles had a particle diameter of 100 nm or less. As a pigment dispersant, the dried compound (7) was charged into a continuous small hammer mill equipped with a 0.5 mmφ screen and pulverized at 6000 rpm. After the pulverization, a pigment dispersant (7-1) was obtained through a sieve corresponding to 400 mesh. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 23.9 μm.
The pigment (D) and the pigment dispersant (7-1) were mixed at a ratio of 92% to 8% to obtain a pigment composition.

(Comparative Example 5)
As a pigment dispersant, the dried product of the compound (7) was charged into a continuous small hammer mill equipped with a 1.0 mmφ screen to obtain a pigment dispersant (7-2) pulverized at 3500 rpm. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 41.6 μm.
The pigment (D) obtained in the same manner as in Example 4 and the pigment dispersant (7-2) were mixed at a ratio of 92% to 8% to obtain a pigment composition.

(Example 5)
As an organic pigment, C.I. I. Pigment YELLOW 138 (BASF "Pariol Yellow K0961HD") 100 parts, sodium chloride 700 parts, diethylene glycol 120 parts were charged into a 1000-volume part double-arm kneader and kept in a dense lump (dough) at 80 ° C. It refined | miniaturized by the solvent salt milling method for 15 hours. This pigment was taken out in water at 70 ° C., stirred for 1 hour, filtered and washed with water to remove sodium chloride and diethylene glycol, and then dried and pulverized at 80 ° C. When the obtained pigment (E) was observed with an electron microscope, it was confirmed that 80% or more of primary particles had a particle diameter of 100 nm or less. As a pigment dispersant, the dried compound (11) was charged into a continuous small hammer mill equipped with a 0.5 mmφ screen and pulverized at 6000 rpm. After pulverization, a pigment dispersant (11-1) was obtained by passing through a sieve corresponding to 400 mesh. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 25.3 μm.
The pigment (E) and the pigment dispersant (11-1) were mixed at a ratio of 90% to 10% to obtain a pigment composition.

(Comparative Example 6)
As a pigment dispersant, the dried product of the compound (11) was charged into a continuous small hammer mill equipped with a 3.0 mmφ screen to obtain a pigment dispersant (11-2) pulverized at 6000 rpm. The particle diameter (90.0% D) at which the volume cumulative particle amount of this pigment dispersant was 90% was 39.2 μm.
The pigment (E) obtained in the same manner as in Example 5 and the pigment dispersant (11-2) were mixed at a ratio of 90% to 10% to obtain a pigment composition.

(Evaluation method and evaluation results)
In a 225 ml mayonnaise bottle, 10 parts of the pigment composition, 40 parts of an acrylic resin cyclohexanone solution (non-volatile content 20%), 48 parts of cyclohexanone and 200 parts of 1.25 mmφ zirconia beads are mixed and mixed in a paint conditioner. A pigment dispersion was prepared by time dispersion. With respect to this pigment dispersion, the fluidity immediately after preparation and the fluidity after standing for 24 hours at 40 ° C. (stability with time) were measured with a BM viscometer. Moreover, the glossiness of the coating film which was developed on a PET film with a wet film thickness of 12 μm and dried at 150 ° C. for 2 minutes was measured.
Using the pigment compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 6, the measured values of fluidity and gloss of the inks prepared by the above evaluation methods are shown in Table 1. Regarding the stability over time, the rate of increase in viscosity after storage at 40 ° C. for 2 weeks was evaluated in the following four stages, and is also shown in Table 1.
◎: There is almost no thickening ○: Slightly thickening is seen, but usable range △: Thickening is seen and cannot be used ×: There is significant thickening and cannot be used

In any case, the pigment composition of the present invention had a low viscosity, excellent fluidity and stability over time, and excellent coating film gloss.
In addition, the pigment compositions of Examples 1 to 5 have a pigment composition concentration of 20%, and include ion-exchanged water, glycerin, diethylene glycol monobutyl ether, styrene / maleic acid resin, and the like in finely dispersed aqueous ink. Even when used, it showed good dispersibility and fluidity, and stability over time.

Claims (3)

  A pigment composition comprising at least one pigment dispersant selected from the group consisting of organic dye derivatives, anthraquinone derivatives, and triazine derivatives having an amino group, a sulfo group, or a carboxyl group, and a pigment, A pigment composition having a pulverized particle size of 30 μm or less with a volume cumulative particle amount of 90%.  2. The pigment composition according to claim 1, wherein among the pigments, pigment particles having a primary particle diameter of 100 nm or more are 20% by weight or less of the total pigment particles. A pigment dispersion obtained by dispersing the pigment composition according to claim 1 or 2 in a non-aqueous or aqueous vehicle.