JP2006206737A - Pigment composition and pigment dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment composition and a pigment dispersion excellent in flowability, dispersion stability, and gloss of a dried coating film thereof when used for printing inks or coatings. <P>SOLUTION: The pigment composition comprises a pigment and a compound represented by general formula (1). The pigment dispersion comprises the pigment composition, a resin, and a solvent. In general formula (1), X denotes O or NH; and R<SB>1</SB>-R<SB>4</SB>denote each independently a hydrogen atom, a halogen atom, a nitro group, a sulfonic acid group, a carboxy group, a formyl group, or an alkyl group, an aryl group, an alicyclic group, an aralkyl group, a heterocyclic group, an alkoxy group, an aryloxy group, an alkylthio group, an arylthio group, an alkylamino group, a dialkylamino group, an arylamino group, a diarylamino group, a phthalimidemethyl group, or a sulfonamide group, which may have a substituent. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to pigment compositions and pigment dispersions used in printing inks such as gravure inks and flexographic inks, various general paints for automobiles and metals, and more specifically for printing inks and paints. The pigment composition and the pigment dispersion are excellent in fluidity, dispersion stability, and gloss when dried.

Generally, in various coatings or ink compositions, a practically useful pigment that exhibits a clear color tone and high coloring power is composed of fine particles. However, when fine particles of pigment are dispersed in a vehicle such as offset ink, gravure ink, paint, etc., it is difficult to obtain a stable dispersion, which has a significant effect on manufacturing operations and the value of the product obtained. Known to cause problems.
For example, a dispersion containing a pigment composed of fine particles often shows high viscosity, and it is difficult not only to take out the product from the disperser and transfer it from the disperser to a tank, etc. It may become difficult to use due to gelation during storage. In addition, when different types of pigments are mixed and used, phenomena such as color separation and sedimentation due to aggregation of pigments may cause uneven color and a marked decrease in coloring power in the developed product. In addition, the surface of the color-extracted coating film may cause poor conditions such as a decrease in gloss and poor leveling.

Although not directly related to the dispersion of the pigment, some organic pigments have a phenomenon accompanied by a change in the crystal state of the pigment. In other words, in the case of offset ink, gravure ink, paint, etc., the pigment crystal particles that were in an unstable state in the vehicle change their size and form, etc., and shift to a stable state. In a color-exhibited product, the product value may be impaired by a significant change in hue, a decrease in coloring power, generation of coarse particles, and the like.
In order to solve the above problems, in various fields in which pigments are dispersed, pigment derivatives in which a functional group such as an acidic group, a basic group, or a phthalimidomethyl group is introduced into the pigment skeleton, or acrylic resins or polyesters Resin-type pigment dispersants in which an acidic group or basic group is introduced into a part of the resin have been developed and used alone or in combination, and are extremely effective. In addition, so-called resin-type pigment derivatives in which a pigment skeleton is bonded to a part of the resin have been developed.

Among these, pigment derivatives having an acidic group (hereinafter referred to as acidic pigment derivatives) are used in pigment skeletons such as phthalocyanine pigments, quinacridone pigments, azo pigments, anthraquinone pigments, diketopyrrolopyrrole pigments, and isoindoline pigments. On the other hand, acidic groups such as sulfonic acid groups and carboxyl groups are introduced and have been used for a long time as dispersants and particle growth inhibitors. However, the present situation is that the viscosity, flow characteristics, and viscosity stability with time are not sufficiently satisfactory (see Patent Documents 1 and 2).
JP 2002-179799 A JP-A-9-176511

  The problem to be solved by the present invention is to provide a pigment composition and a pigment dispersion that are excellent in fluidity, dispersion stability, gloss when used as a dry coating film, etc. when used in printing inks and paints. .

（式中、Ｘは、ＯまたはＮＨを表す。Ｒ₁〜Ｒ₄はそれぞれ独立に、水素原子、置換基を有してもよいアルキル基、置換基を有してもよいアリール基、置換基を有してもよい脂環基、置換基を有してもよいアラルキル基、置換基を有してもよい複素環基、置換基を有してもよいアルコキシ基、置換基を有してもよいアリールオキシ基、置換基を有してもよいアルキルチオ基、置換基を有してもよいアリールチオ基、置換基を有してもよいアルキルアミノ基、置換基を有してもよいジアルキルアミノ基、置換基を有してもよいアリールアミノ基、置換基を有してもよいジアリールアミノ基、ハロゲン原子、ニトロ基、スルホン酸基、カルボキシル基、ホルミル基、置換基を有してもよいフタルイミドメチル基、または置換基を有してもよいスルホンアミド基を表す。）
また、本発明の顔料分散体は、本発明の顔料組成物と、樹脂と、溶剤とを含むことを特徴とする。 The pigment composition of the present invention is characterized by containing a pigment and a compound represented by the following general formula (1).

(In the formula, X represents O or NH. R _{1 to} R ₄ each independently represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a substituent. An alicyclic group that may have a substituent, an aralkyl group that may have a substituent, a heterocyclic group that may have a substituent, an alkoxy group that may have a substituent, and a substituent. An aryloxy group which may have a substituent, an alkylthio group which may have a substituent, an arylthio group which may have a substituent, an alkylamino group which may have a substituent, a dialkylamino which may have a substituent Group, arylamino group which may have a substituent, diarylamino group which may have a substituent, halogen atom, nitro group, sulfonic acid group, carboxyl group, formyl group, may have a substituent Phthalimidomethyl group, or It represents a N'amido group.)
The pigment dispersion of the present invention is characterized by including the pigment composition of the present invention, a resin, and a solvent.

  Since the pigment composition of the present invention contains the compound represented by the above general formula (1) having an action of stably dispersing fine particles of the pigment in the vehicle, it is excellent by using the pigment composition of the present invention. Printing inks and paints that have excellent fluidity and dispersion stability, and are excellent in gloss and hue when dried.

First, the pigment composition of the present invention will be described.
The pigment composition of the present invention contains a pigment and a compound represented by the above general formula (1).
As the pigment, various organic pigments and inorganic pigments that are generally commercially available can be used. Examples of organic pigments include azo, anthanthrone, anthrapyrimidine, anthraquinone, isoindolinone, isoindoline, indanthrone, quinacridone, quinophthalone, dioxazine, and diketopyrrolopyrrole. Organic pigments such as thioindigo, pyranthrone, phthalocyanine, flavanthrone, perinone, perylene, benzimidazolone, and the like. Among them, isoindoline pigments, particularly CI (Color Index) Pigment Yellow 185 pigment, are difficult pigments to stably disperse in a vehicle when a conventional pigment dispersant is used. ), A stable dispersion in the vehicle becomes possible.
Examples of inorganic pigments include carbon black, titanium oxide, yellow lead, cadmium yellow, cadmium red, dial, iron black, zinc white, bitumen, ultramarine blue, and the like.
Two or more of these pigments may be used in combination.

The compound represented by the general formula (1) is a compound that functions to stably disperse fine pigment particles in a vehicle.
Among the compounds represented by the above general formula (1), the compound in which X is NH is amide methyl cyanoacetate and 1,3-diiminoisoindoline at pH 8 to 11 at a temperature of 10 to 100 ° C. It can be synthesized by reacting.
Moreover, among the compounds represented by the general formula (1), a compound in which X is O can be obtained by heating a compound in which X is NH, for example, in an acetic acid aqueous solution.
Furthermore, as a method for introducing a substituent into R _{1 to} R ₄ , a known method can be used.

The compound represented by the general formula (1) can be added to the pigment by a method such as powder mixing or wet mixing.
It can also be added to the pigment in the process of producing the pigment, for example, during the process of synthesizing the pigment, during the process of solvent salt milling with a kneader, and during the subsequent treatment process, the pigment is dried by an attritor It can be added during the pulverizing step or the subsequent processing step. The pigment composition of the present invention may contain two or more compounds represented by the general formula (1).
The content of the compound represented by the general formula (1) contained in the pigment composition of the present invention is preferably 5 to 20 parts by weight with respect to 100 parts by weight of the pigment. More preferably, it is 15 parts by weight.

Next, the pigment dispersion of the present invention will be described.
The pigment dispersion of the present invention comprises the pigment composition of the present invention, a resin, and a solvent. The pigment composition of the present invention and a varnish (resin solvent solution) for printing ink or paint. If necessary, it can be produced by mixing with a solvent and dispersing with a dispersing machine such as a ball mill or a sand mill.
In the pigment dispersion of the present invention, the resin content is approximately 80 to 2000 parts by weight with respect to 100 parts by weight of the pigment contained in the pigment composition. Moreover, content of a solvent is about 200-38000 weight part with respect to 100 weight part of pigments contained in a pigment composition.

  The organic solvent used in the pigment dispersion of the present invention is not particularly limited, but benzene, toluene, xylene, ethylbenzene, chlorobenzene, nitrobenzene, aniline, pyridine, quinoline, tetrahydrofuran, dioxane, methanol, ethanol, isopropanol, n- Propanol, isobutanol, n-butanol, ethylene glycol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol, propylene glycolic monomethyl ether acetate, ethyl acetate, isopropyl acetate, butyl acetate, Isobutyl acetate, isopentyl acetate, hexane, heptane, octane, nonane, decane, undeca , Dodecane, cyclohexane, methylcyclopentane f Sasan, halogenated hydrocarbons, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, dimethylformamide, dimethyl sulfoxide, N- methylpyrrolidone and the like. Two or more kinds of solvents may be mixed and used as necessary.

  The resin used in the pigment dispersion of the present invention is not particularly limited, but rosin, rosin derivative, rosin modified maleic resin, rosin modified phenolic resin, rubber derivative, protein derivative, chlorinated polyethylene, chlorinated polypropylene, poly Vinyl chloride, polyvinyl acetate, epoxy resin, acrylic resin, maleic acid resin, styrene resin, styrene-maleic acid copolymer resin, butyral resin, polyester resin, melamine resin, phenol resin, polyurethane resin, polyamide resin, polyimide resin, alkyd Examples thereof include resins, rubber resins, celluloses, benzoguanamine resins, urea resins, and oligomers and monomers of the above resins. Two or more kinds of resins may be mixed and used as necessary.

To the pigment composition and pigment dispersion of the present invention, additives such as a surfactant, a silane coupling agent, and a leveling agent may be added for the purpose of improving coatability and adhesion.
Moreover, you may add dispersing agents, such as a pigment derivative, to the pigment composition and pigment dispersion of this invention as needed. Examples of the pigment derivative are described in JP-A-63-305173, JP-B-57-15620, JP-B-59-40172, JP-B-63-17102, JP-B-5-9469, and the like. These can be used alone or in combination of two or more.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited by this. In Examples and Comparative Examples, “parts” means “parts by weight” and “%” means “% by weight”.

(Production Example 1)
To 14.7 parts of ethyl cyanoacetate was added 10 parts of a 40% methylamine methanol solution, and the mixture was heated and stirred at the boiling point for 2 hours. After cooling to 50 ° C, 300 parts of methanol and 19 parts of 1,3-diiminoisoindoline were added, and the mixture was further stirred at 50 ° C for 2 hours and then cooled to room temperature. Washing was performed 3 times with 100 parts of methanol to obtain a compound (2) having the following structure.
Compound (2)

(Production Example 2)
To 30 parts of the compound (2) obtained in Production Example 1, 1000 parts of a 60% aqueous acetic acid solution was added, stirred at the boiling point for 5 hours, and cooled to room temperature. After washing with water, a compound (3) having the following structure was obtained.
Compound (3)

Example 1
10 parts of isoindoline pigment (CI Pigment Yellow 185: “PALIOTOL YELLOW D1155” manufactured by BSF Corporation), 2.0 parts of compound (2), pigment derivative (4) shown below: 5 parts, 90 parts of gravure ink varnish (nitrocellulose resin 12%, ethyl acetate 33%, toluene 30%, isopropyl alcohol 15%, methanol 10%) and 3 parts of 3 mm glass beads are mixed and dispersed in a paint conditioner for 60 minutes. Thus, a gravure ink was prepared.
Pigment derivative (4)

(Example 2)
A gravure ink was prepared in the same manner as in Example 1 except that the amount of compound (2) added was changed from 1.5 parts to 1.0 part.
(Example 3)
A gravure ink was prepared in the same manner as in Example 2 except that the pigment derivative (4) was changed to the pigment derivative (5) shown below.
Pigment derivative (5)

Example 4
A gravure ink was prepared in the same manner as in Example 2 except that the compound (2) was changed to the compound (3).
(Example 5)
20 parts of isoindoline pigment (CI Pigment Yellow 185: “PALIOTOL YELLOW D1155” manufactured by BASF Corporation), 2.0 parts of compound (3), 1.0 part of pigment derivative (4), 80 parts of varnish for gravure ink (urethane resin 15%, ethyl acetate 65%, isopropyl alcohol 20%) and 100 parts of 3 mm glass beads were mixed and dispersed for 60 minutes with a paint conditioner to prepare gravure ink. In addition, as said urethane resin, the weight average about which the prepolymer obtained by polycondensing the polyester polyol and isophorone diisocyanate which polycondensated 3-methyl- 1, 5-pentanediol and adipic acid was chain-extended with isophorone diamine. 30000 urea bond-containing urethane resin was used.

(Example 6)
A gravure ink was produced in the same manner as in Example 4 except that the pigment derivative (4) was changed to the pigment derivative (5).
(Example 7)
A gravure ink was prepared in the same manner as in Example 4 except that the pigment derivative (4) was not used.
(Example 8)
A gravure ink was produced in the same manner as in Example 6 except that the amount of compound (3) added was changed from 1.0 part to 0.6 part.
(Comparative Example 1)
A gravure ink was produced in the same manner as in Example 1 except that the compound (2) was not used.

The viscosity of the inks prepared in Examples 1 to 8 and Comparative Example 1 was measured with a B-type viscometer. Further, after the prepared ink was stored at 40 ° C. for 7 days, the viscosity was measured with a B-type viscometer, and the storage stability with time was evaluated by the rate of change in viscosity immediately after the ink preparation and after storage with time. Further, the gloss value (60 °) of the dried film when the produced ink was developed on a film with a bar coater was measured. The results are shown in Table 1.
As shown in Table 1, the gravure inks of Examples 1 to 8 using the pigment composition of the present invention had excellent fluidity with low viscosity, and also had excellent coating film gloss. On the other hand, the comparative example 1 gravure ink using the pigment composition not containing the compound of the general formula (1) is compared with the gravure inks of Examples 1 to 8 in fluidity, storage stability with time, and coating gloss. It was remarkably inferior.

Example 9
12 parts of isoindoline pigment (CI Pigment Yellow 185: "PSIOL YELLOW D1155" manufactured by BASF Corporation), 2.0 parts of compound (2), 0.5 part of pigment derivative (4), 40 parts of an alkyd resin varnish for coating (“Phtalkid 133-60” manufactured by Hitachi Chemical Co., Ltd.), 20 parts of xylene and 300 parts of 3 mm steel beads were mixed and dispersed for 60 minutes with a paint conditioner. To this mixture, 72 parts of an alkyd resin varnish for paint and 56 parts of a melamine resin varnish for paint (“Melan 20” manufactured by Hitachi Chemical Co., Ltd.) were added and dispersed for another 10 minutes using a paint conditioner to prepare a paint.
(Example 10)
A paint was prepared in the same manner as in Example 9 except that the compound (2) was changed to the compound (3).
(Comparative Example 2)
A paint was prepared in the same manner as in Example 9 except that the compound (2) was not used.

The viscosities of the paints prepared in Examples 9 and 10 and Comparative Example 2 were measured with a B-type viscometer, and the storage stability over time was evaluated in the same manner as the ink.
Further, the dispersion stability was evaluated based on the color separation stability, which is particularly problematic for applications. That is, the paints prepared in Examples 9 and 10 and Comparative Example 2 were cut with a titanium oxide base paint prepared in advance with an alkydmelamine resin varnish so that the ratio of pigment to titanium oxide would be 1/10, and the light color A paint was obtained. This light-colored paint was further diluted with xylene, and Ford Cup No. 4 was adjusted to 20 seconds (25 ° C.), poured into a test tube, and the change in the glass wall surface was observed. The results are shown in Table 1.
As shown in Table 1, the paints of Examples 9 and 10 using the pigment composition of the present invention have a low viscosity and excellent fluidity, and the storage stability with time is excellent with little degree of thickening. It was. On the other hand, the paint of Comparative Example 2 using the pigment composition not containing the compound of the general formula (1) was remarkably inferior to the paints of Examples 9 and 10 in fluidity and storage stability with time. .

(Example 11)
10 parts of phthalocyanine pigment (CI Pigment Green 7: “LIONOL GREEN YS” manufactured by Toyo Ink Manufacturing Co., Ltd.), 0.6 part of Compound (3), 1.0 part of pigment derivative (5), varnish for gravure ink ( 90 parts of 12% nitrocellulose resin, 33% ethyl acetate, 30% toluene, 15% isopropyl alcohol, 10% methanol) and 100 parts of 3 mm glass beads were mixed and dispersed for 60 minutes with a paint conditioner to prepare a gravure ink.
(Comparative Example 3)
A gravure ink was produced in the same manner as in Example 11 except that the compound (3) was not used.

(Example 12)
10 parts of isoindoline pigment (CI Pigment Yellow 139: “PALIOTOL YELLOW D1819” manufactured by BASF Corporation), 0.6 part of compound (3), 1.0 part of pigment derivative (5), Gravure ink varnish (nitrocellulose resin 12%, ethyl acetate 33%, toluene 30%, isopropyl alcohol 15%, methanol 10%) 90 parts and 3 mm glass beads 100 parts are mixed and dispersed for 60 minutes with a paint conditioner for gravure. An ink was prepared.
(Comparative Example 4)
A gravure ink was produced in the same manner as in Example 11 except that the compound (3) was not used.

  The viscosity of the inks prepared in Examples 11 and 12 and Comparative Examples 3 and 4 was measured with a B-type viscometer. Further, after the prepared ink was stored at 40 ° C. for 7 days, the viscosity was measured with a B-type viscometer, and the storage stability with time was evaluated by the rate of change in viscosity immediately after the ink preparation and after storage with time. Further, the gloss value (60 °) of the dried film when the produced ink was developed on a film with a bar coater was measured. The results are shown in Table 1.

（＊１）：表中、粘度（6rpm、60rpm）の単位は、ｍPa・sである。
（＊２）：表中、経時保存安定性の評価基準は、以下の通りである。
◎：粘度変化率 10%未満 ○：粘度変化率 10%以上30%未満
△：粘度変化率 30%以上50%未満 ×：粘度変化率 50%以上
（＊３）：表中、色分かれ安定性の評価基準は、以下の通りである。
◎：全く均一、 ○：僅かに白いすじが認められる
△：白い縞模様状態、 ×：白が完全に分離

(* 1): In the table, the unit of viscosity (6 rpm, 60 rpm) is mPa · s.
(* 2): In the table, the evaluation criteria for storage stability over time are as follows.
◎: Viscosity change rate less than 10% ○: Viscosity change rate 10% or more and less than 30%
Δ: Viscosity change rate 30% or more and less than 50% ×: Viscosity change rate 50% or more (* 3): In the table, the evaluation criteria for color separation stability are as follows.
◎: Completely uniform ○: Slight white streaks are observed
Δ: White striped pattern, ×: White is completely separated

Claims (5)

A pigment composition comprising a pigment and a compound represented by the following general formula (1).

(In the formula, X represents O or NH. R _{1 to} R ₄ each independently represents a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, or a substituent. An alicyclic group that may have a substituent, an aralkyl group that may have a substituent, a heterocyclic group that may have a substituent, an alkoxy group that may have a substituent, and a substituent. An aryloxy group which may have a substituent, an alkylthio group which may have a substituent, an arylthio group which may have a substituent, an alkylamino group which may have a substituent, a dialkylamino which may have a substituent Group, arylamino group which may have a substituent, diarylamino group which may have a substituent, halogen atom, nitro group, sulfonic acid group, carboxyl group, formyl group, may have a substituent Phthalimidomethyl group, or It represents a N'amido group.)   The pigment composition according to claim 1, wherein the pigment is an isoindoline pigment.   The pigment composition according to claim 2, wherein the isoindoline pigment is C.I. Pigment Yellow 185 pigment.   The pigment composition according to any one of claims 1 to 3, wherein the content of the compound represented by the general formula (1) is 5 to 20 parts by weight with respect to 100 parts by weight of the pigment. . A pigment dispersion comprising the pigment composition according to any one of claims 1 to 4, a resin, and a solvent.