JP2009143993A - Monoazo metal complex, azo type pigment dispersant and pigment composition containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize, in a pigment composition using a yellow pigment having a structure based on barbituric acid typified by C.I. Pigment Yellow 150, making the pigment finer and highly concentrated without being accompanied by high viscosity just after the dispersion, coagulation, sedimentation and viscosity increase with time, and to provide a stable pigment composition as a colorant for resists of color filters and inks of inkjets. <P>SOLUTION: The metal complex consists of two molecules of an azo compound having barbituric acid as coupling components with cobalt, zinc and the like. The azo type pigment dispersant using this as an effective component is provided. Further, the pigment composition is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a monoazo metal complex, an azo pigment dispersant, and a fine, fluid and transparent pigment composition used for color filter resists and inkjet inks used in the production of liquid crystal displays and imaging devices. .

  In recent years, pigments have been used as colorants for paints and printing inks, and in recent years for color filter resists and inkjet inks. The pigment has various characteristics such as heat resistance, weather resistance, migration resistance, etc., and is excellent in fastness as compared with the dye. On the other hand, the pigment has a high viscosity immediately after dispersion, agglomeration, sedimentation, and aging. Potential problems such as increase in viscosity and color separation when mixed with different pigments.

  Recently, with the demands for higher contrast of liquid crystal displays, finer imaging devices, higher coloration and sharpness of inkjet inks, the demand for finer pigments and higher concentrations in dispersed compositions has increased. However, the finer the particle size and the higher the pigment concentration, the easier it is to cause aggregation, making it difficult to obtain a stable dispersion composition.

  In order to solve these problems, the improvement of the pigment itself (pigment surface treatment), the development of dispersants with good adsorptivity to pigments, the development of surfactants, and proposals for pigment dispersants have been made so far Has been done. Examples of pigments used in color filters and inkjet inks include phthalocyanine pigments, diketopyrrolopyrrole pigments, anthraquinone pigments, quinacridone pigments, dioxazine pigments, isoindoline pigments, isoindolinone pigments, and azo pigments. Examples include pigments and dye lake pigments, and a number of pigment dispersants have been reported, particularly phthalocyanine pigments, anthraquinone pigments, and quinacridone pigments. For example, a method of mixing a sulfonated pigment or a metal salt thereof with a pigment (Patent Documents 1 to 3), a method of mixing a substituted aminomethyl derivative (Patent Document 4), and a method of mixing a phthalimidomethyl derivative (Patent Document 5). Etc. are known.

  These methods are effective for pigments having a specific skeleton, but are not useful for pigments having a skeleton in which it is difficult to introduce a sulfone group, an aminomethyl group, a phthalimidomethyl group, or the like. In particular, C.I. currently widely used in the field of color filters and inkjets. I. For Pigment Yellow No. 150, an appropriate pigment dispersant has not existed so far, so that the pigment was very difficult to disperse. In Patent Documents 6 and 7, C.I. I. Dispersion stability is maintained by inclusion of an inclusion compound, particularly a melamine compound, with respect to CI Pigment Yellow No. 150. This does not satisfy the demand for higher concentration of pigment in the composition.

Japanese Patent Publication No.41-2466 JP 63-172772 A Shoko 50-4019 Japanese Patent Publication No. 39-16787 JP 55-108466 JP 2000-119544 A JP 2005-344055 A

  The problem to be solved by the present invention is C.I. I. Pigment Yellow 150, a pigment based on a structure based on barbituric acid, can be made fine and highly dispersed in a dispersion composition without increasing viscosity immediately after dispersion, aggregation, sedimentation, or increase in viscosity over time. This is to provide a stable pigment composition as a color filter resist or ink jet ink.

  As a result of intensive studies to solve the above problems, the present inventor can solve the above problems by using a metal complex of an azo compound composed of aminophenolsulfonic acid or a derivative thereof and barbituric acid, and a salt thereof. As a result, the present invention has been completed.

That is, the present invention provides the following formula (1)

(Represented in the formula _{(1), R 1, R} 2 each independently represent a hydrogen atom, an alkyl group of C ₁ -C _4, alkoxy group of C ₁ -C _4, a chlorine atom, any of a bromine atom and a nitro group M represents a hydrogen atom, sodium, potassium, magnesium, calcium, barium, or aluminum, M ^{n +} represents an n-valent cation, Metal represents any of Co, Zn, Fe, Ni, Cu, and Al X and y each independently represents an integer of 0, 1, 2 or 3 (except that x and y are simultaneously 0), and n represents an integer of 1, 2 or 3. A monoazo metal complex,
(2) The following formula (2)

(In the formula (2), R ₃ ~R ₅ independently of one another are hydrogen, C ₁ -C ₁₈ alkyl groups, aralkyl groups, C ₅ or a cycloalkyl group having C _6, aryl and C ₅ or C ₆ Represents any one of C _{1 to} C ₁₈ alkyl groups substituted by cycloalkyl group, wherein R ₁ , R ₂ , Metal, x and y have the same meaning as in formula (1) described in (1) above. A monoazo metal complex represented by
(3) An azo pigment dispersant containing the monoazo metal complex according to (1) or (2) as an active ingredient,
(4) a pigment composition containing an organic pigment, the azo pigment dispersant described in (3) above, and a resin pigment dispersant;
(5) The pigment composition according to (4), wherein the resin-type pigment dispersant is cationic.
(6) The pigment composition as described in (5) above, wherein the resin-type pigment dispersant has an acrylic or polyester skeleton.
(7) The pigment composition according to the above (4), wherein the addition amount of the azo pigment dispersant relative to the organic pigment is 0.1 to 50% by mass,
(8) The pigment composition according to (4), wherein the organic pigment is a yellow pigment having a structure based on barbituric acid,
(9) The organic pigment is C.I. I. Pigment Yellow 139, 150 or 185, the pigment composition according to (7) above,
About.

  The monoazo metal complex represented by the formulas (1) and (2) of the present invention can be produced very easily. By using the metal complex as an azo pigment dispersant, C.I. I. Pigment Yellow 150, a pigment based on a structure based on barbituric acid, can be made fine and highly dispersed in a dispersion composition without increasing viscosity immediately after dispersion, aggregation, sedimentation, or increase in viscosity over time. The concentration can be increased, and a stable pigment composition can be obtained as a color filter resist or a colorant for inkjet ink.

  A structural feature of the monoazo metal complex of the present invention is that it is an azo metal-containing complex having a sulfonic acid group. The monoazo metal complex of the present invention represented by the general formula (1) can be produced, for example, as follows. That is, after diazotizing an aromatic amine represented by the following formula (A) by a conventional method, a coupler represented by the following formula (B) and a reaction temperature of 0 to 40 ° C., preferably 10 to 30 ° C., and pH 3 to 3 The intermediate (C) is obtained by a coupling reaction at 10, preferably 4-8. Next, the intermediate (C) is raked using a half equivalent metal halide or the like, whereby a desired compound represented by the following formula (1-a) can be obtained. On the other hand, the compound represented by (1-b) is raked using an equivalent amount of a metal halide or the like to intermediate (C) to form a compound represented by (D), and then intermediate (C) and It can manufacture by adding the intermediate body (E) manufactured by the same manufacturing method, and performing reaction.

In formulas (A), (B), (C), (D), (E), (1-a) and (1-b), R ₁ and R ₂ are each independently a hydrogen atom, C _1- alkyl C _4, alkoxy group of C ₁ -C _4, a chlorine atom, represents either a bromine atom and a nitro group. M represents a hydrogen atom, sodium, potassium, magnesium, calcium, barium or aluminum, and M ^{n +} represents an n-valent cation. Metal represents any of Co, Zn, Fe, Ni, Cu, and Al. x and y each independently represents an integer of 0, 1, 2 or 3 (except that x and y are simultaneously 0), and n represents an integer of 1, 2 or 3.

  Furthermore, the desired compound shown by following formula (2) can be obtained by salt-forming the compound shown by (1-a) and (1-b) using various amines.

(In the formula (2), R ₃ ~R ₅ independently of one another are hydrogen, C ₁ -C ₁₈ alkyl groups, aralkyl groups, C ₅ or a cycloalkyl group having C _6, aryl and C ₅ or C ₆ And any one of C _{1 to} C ₁₈ alkyl groups substituted by cycloalkyl group of R ₁ , R ₂ , Metal, x and y have the same meaning as in formula (1) above.)

Examples of the C ₁ -C ₄ alkyl group in the above formula (1) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, and a t-butyl group. Etc.

The alkoxy group of C ₁ -C ₄ in the formula (1), a methoxy group, an ethoxy group, n- propoxy group, iso- propoxy group, n- butoxy group and the like.

  Examples of the amine used for salt formation of the compound of the above formula (1) include ammonia, dimethylamine, triethylamine, 2-ethylhexylamine, laurylamine, octadecylamine, oleylamine, benzylamine, and rosinamine (18-aminoabieta). -8,11,13-triene) and the like.

Examples of the C _{1 to} C ₁₈ alkyl group in the above formula (2) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, and t- Examples thereof include a butyl group, a lauryl group, an octadecyl group, an oleyl group, a 2-ethylhexyl group, and a cyclohexylmethyl group.

  Examples of the aralkyl group in the above formula (2) include a benzyl group and a phenylethyl group.

Examples of the C ₅ or C ₆ cycloalkyl group in the above formula (2) include a cyclopentyl group and a cyclohexyl group.

  Examples of the aryl group in the above formula (2) include a phenyl group and a naphthyl group.

  Next, specific examples of the monoazo metal complex represented by the formulas (1) and (2) of the present invention are shown in Tables 1 and 2 based on the following formulas (3) and (4).

  The pigment composition of the present invention can be prepared, for example, by the following method. That is, as a method of blending the organic pigment and the azo type pigment dispersant, various conventionally known methods, for example, a method of simply mixing each dry powder or press cake, various kinds such as a kneader, a bead mill, a dissolver, an attritor, etc. Examples include a method of mechanically mixing with a disperser, a method of suspending an organic pigment in water or an organic solvent, and adding and mixing an azo type pigment dispersant therein to deposit uniformly on the surface of the organic pigment. . Next, a mixture of the obtained organic pigment and azo type pigment dispersant is blended with a resin type pigment dispersant and various organic solvents, a resin varnish, various additives, etc. as necessary, and a sand mill, an annular type bead mill, By dispersing with an attritor or the like, a desired pigment composition can be produced. Alternatively, for convenience, the organic pigment, the azo pigment dispersant of the present invention, the resin pigment dispersant, and other components as necessary may be mixed and dispersed all at once. In addition, the addition amount of an azo type pigment dispersant is 0.1-50 mass% with respect to an organic pigment, Preferably it is 0.5-30 mass%, More preferably, it is 1-20 mass%. If the blending ratio of the azo-type pigment dispersant is too small, the desired dispersion stability and pigment fineness cannot be achieved. Is necessary.

  The organic pigment that can be used in the pigment composition of the present invention is not particularly limited as long as it is a conventionally known one such as those described in Color Index (CI), but monoazo which is the azo pigment dispersant of the present invention is not particularly limited. Since the metal complex itself has a yellow hue, it is preferable to use a yellow organic pigment in the sense that the original hue of the organic pigment is not impaired. In addition, a pigment having a structure based on barbituric acid in the structure is preferable in the sense that the monoazo metal complex of the present invention is excellent in affinity with a structural site based on barbituric acid. The term “pigment having a structure based on barbituric acid” in the present application means the meaning of a pigment having a structural site derived from barbituric acid in the structure. Therefore, more preferable organic pigments include C.I., which is a yellow pigment having a structure based on barbituric acid. I. And CI Pigment Yellow 139, 150 and 185.

  As a specific example of “a pigment having a structure based on barbituric acid”, C.I. I. The structure of Pigment Yellow 139 is represented by C.I. I. The structure of CI Pigment Yellow No. 150 is expressed by C.I. I. The structures of Pigment Yellow 185 are shown.

The resin-type pigment dispersant that can be used in the pigment composition of the present invention is not particularly limited as long as it is a known resin-type pigment dispersant, but it has an affinity for the sulfonic acid derivative portion of the azo-type pigment dispersant of the present invention. In consideration, it is more preferable to use a cationic resin type dispersant. Examples of the cationic resin-type dispersant include BYK112, 116, 140, 142, 161, 162, 164, 166, 182, 2000, 2001, 2050, 2070, 2150 from Big Chemie, EFKA 4010, 4015, 4020 from Efka. , 4050, 4055, 4060, 4300, 4330, 4400, 4406, Lubrizol Solsperse 24000, 32500, Ajinomoto Fine Techno Co., Ltd. Ajisper PB711, 821, 822, etc., among which the basic skeleton of the resin part is acrylic BYK2000 and 2001, and polyester-based Ajisper PB821 and 822 are particularly preferred from the viewpoint of dispersion stability of the pigment composition.
The addition amount of the resin-type pigment dispersant is 5 to 100 parts by mass, and more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the pigment. When the addition amount of the resin-type pigment dispersant is less than 5 parts by mass, good dispersion stability cannot be obtained.

  If necessary, an organic solvent can be added to the pigment composition of the present invention. The organic solvent that can be used is not particularly limited. Butyl acetate, methanol, ethanol, isopropyl alcohol and the like. These may be used singly or in combination of two or more, and an amount occupying 90% by mass or less in the pigment composition is used.

  If necessary, a resin varnish can be added to the pigment composition of the present invention. Resin varnishes include styrene (co) polymers, (meth) acrylic acid ester (co) polymers, styrene-maleic acid ester copolymers, cellulose acetate resins, polyester resins, polyurethane resins, polyamide resins Examples thereof include resins and polyimide resins. These may be used alone or in combination of two or more, and an amount occupying 50% by mass or less in the pigment composition is used.

  Other additives that can be added to the pigment composition of the present invention as necessary include, for example, thixotropic agents, polymerizable resins, polymerization initiators and curing agents, curing accelerators, polymerization inhibitors, organic or inorganic fillers. Coupling agents and the like, but these may be selected according to the specific intended use of the pigment composition and are not limited to the above. Further, the addition amount may be selected according to the specific intended use.

  The use of the pigment composition of the present invention is not particularly limited. For example, various printing inks such as gravure printing inks, paints, various dry toners or wet toners for electrophotography, inks for inkjet recording, resist colorants for color filters, and the like. It can be used for In particular, the pigment composition of the present invention is useful as a resist colorant for color filters and ink for ink jet recording that require finer pigments and high stability.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the text, “parts” and “%” are based on mass unless otherwise specified.

Example 1 (Synthesis of a substance represented by Compound No. 1 in Table 1)
Suspend 94.6 parts of 2-aminophenol-4-sulfonic acid in 500 parts of water, dissolve completely with caustic soda at pH 6-7, add 38.0 parts of sodium nitrite and Dissolved. This solution was added dropwise to 450 parts of a 14% aqueous hydrochloric acid solution at 5 to 10 ° C. over 30 minutes and stirred at the same temperature for 2 hours to carry out a diazotization reaction. Subsequently, the diazotization reaction solution was added dropwise to an aqueous solution in which 64 parts of barbituric acid was dissolved in 2,400 parts of water at 10 to 15 ° C. over 30 minutes, and the pH was adjusted to 5 to 6 using caustic soda. . After reacting for 15 hours at the same temperature and pH, 151 parts of the compound represented by the formula (8) were obtained by removing the solid content by filtration. Next, 151 parts of the compound represented by the formula (8) are suspended in 2,000 parts of water, 102 parts of sodium acetate trihydrate and 45 parts of acetic acid are added, and then 54 parts of cobalt chloride hexahydrate is added. The mixture was heated to 90 ° C., reacted at the same temperature for 2 hours, filtered, and the resulting wet cake was dried with a hot air drier at 80 ° C., whereby compound 142 represented by formula (9) was obtained. Got a part.

Physical property data of compound represented by formula (8)
¹ H-NMR (D ₂ O); 6.95 (attribute c: s, 1H) 7.43 (attribute b: s, 1H) 7.94 (attribute a: s, 1H)

Example 2 (Synthesis of a substance represented by Compound No. 2 in Table 1)
Compound 155 represented by compound number 2 in Table 1 was prepared by synthesizing in the same manner as in Example 1 except that 36 parts of zinc sulfate was used instead of 54 parts of cobalt chloride hexahydrate of Example 1. Got a part.

Example 3 (Synthesis of a substance represented by Compound No. 23 in Table 2)
After 142 parts of the compound obtained in Example 1 were suspended in 2500 parts of water, the pH was adjusted to 8 using caustic soda at 20-25 ° C. To this suspension, an aqueous solution prepared by dissolving 86 parts of 18-aminoabieta-8,11,13-triene in 530 parts of 3.3% acetic acid aqueous solution was added dropwise at 20 to 25 ° C. over 30 minutes. After stirring for a period of time, filtration was performed, and the obtained wet cake was dried with a hot air dryer at 80 ° C. to obtain 200 parts of a compound represented by Compound No. 23 in Table 2.

Example 4 (Synthesis of a substance represented by Compound No. 24 in Table 2)
The compound represented by compound number 24 in Table 2 was synthesized in the same manner as in Example 3 except that the compound was changed to 155 parts of the compound obtained in Example 2 instead of 142 parts of the compound obtained in Example 1. 215 parts were obtained.

Example 5 (Preparation of pigment composition)
As an organic pigment, C.I. I. Pigment Yellow No. 150 (manufactured by LANXESS, Yellow E4GN-GT) 13.8 parts, 0.7 part of the compound obtained in Example 1 as an azo pigment dispersant, Ajisper PB821 (manufactured by Ajinomoto Fine Techno Co., Ltd.) as a resin dispersant , A cationic resin dispersant having a polyester structure) 5.5 parts, and 80.0 parts of propylene glycol monomethyl ether acetate as a solvent were dispersed in a paint shaker for 1 hour using 0.3 mm zirconia beads. The obtained dispersion was filtered with a 5 μm filter to prepare a pigment composition.

Example 6 (Preparation of pigment composition)
A pigment composition was prepared in the same manner as in Example 5 except that the compound obtained in Example 1 was changed to the compound obtained in Example 3.

Example 7 (Preparation of pigment composition)
C. I. Pigment Yellow 150 (Yellow E4GN-GT, manufactured by LANXESS) I. A pigment composition was prepared in the same manner as in Example 6 except that it was changed to CI Pigment Yellow No. 139 (manufactured by Ciba Specialty Chemicals, Yellow 2R-CF).

Comparative Example 1 (Preparation of pigment composition)
A pigment composition was prepared in the same manner as in Example 5 except that the compound obtained in Example 1 was not used.

Comparative Example 2 (Preparation of pigment composition)
A pigment composition was prepared in the same manner as in Example 7 except that the compound obtained in Example 1 was not used.

  For the pigment compositions of Examples 5 to 7 and Comparative Examples 1 and 2, the average particle diameter of the pigment composition was measured using a laser scattering type particle size distribution measuring device, and the room temperature (25 ° C. using a B-type viscometer) ) Viscosity was measured under the condition of 10 rpm. In addition, in order to confirm the storage stability, the viscosity was measured not only at the initial stage (immediately after preparation) but also after standing at 40 ° C. for 3 days and 7 days. The results are shown in Table 3.

As can be seen from Table 3, the pigment compositions of Examples 5 to 7 have a smaller average particle size and are more finely dispersed than the pigment compositions of Comparative Examples 1 and 2. Also, the initial viscosity is kept low compared to the comparative example, and the workability during actual use is not impaired. Furthermore, the storage stability was very good.
Specifically, C.I. I. When CI Pigment Yellow No. 150 was used, the Example had an initial particle size of 75 nm or more smaller than that of the Comparative Example, and the initial viscosity was 90% or more lower. In addition, regarding the rate of increase in viscosity after 7 days, Comparative Example 1 gelled in 3 days, whereas Examples 5 and 6 had a viscosity increase of 22% or less.
Similarly, C.I. I. When Pigment Yellow No. 139 was used, the Example had an initial particle size of 10 nm smaller than that of the Comparative Example, and the initial viscosity was 15% or more lower. Also, the viscosity increase rate after 7 days was 10% or more in the comparative example, whereas no increase in viscosity was observed in Example 7.

From the above results, it was difficult to disperse C.I. by using the monoazo metal complex of the present invention as an azo pigment dispersant. I. A yellow pigment having a structure based on barbituric acid typified by CI Pigment Yellow No. 150 is made into a good pigment composition without increasing viscosity immediately after dispersion, aggregation, sedimentation, or increase in viscosity over time. Obviously it can be done.
In addition, since the effect can be achieved only by using about 5% of the azo type dispersant of the present invention with respect to the pigment, the requirement for increasing the concentration of the pigment in the dispersion composition is satisfied. From the above points, it is clear that the pigment composition using the azo type dispersant of the present invention is very useful as a color filter resist or a colorant for inkjet ink.

Claims (9)

Following formula (1)

(Represented in the formula _{(1), R 1, R} 2 each independently represent a hydrogen atom, an alkyl group of C ₁ -C _4, alkoxy group of C ₁ -C _4, a chlorine atom, any of a bromine atom and a nitro group M represents a hydrogen atom, sodium, potassium, magnesium, calcium, barium, or aluminum, M ^{n +} represents an n-valent cation, Metal represents any of Co, Zn, Fe, Ni, Cu, and Al X and y each independently represents an integer of 0, 1, 2 or 3 (except that x and y are simultaneously 0), and n represents an integer of 1, 2 or 3. A monoazo metal complex represented. Following formula (2)

(In the formula (2), R ₃ ~R ₅ independently of one another are hydrogen, C ₁ -C ₁₈ alkyl groups, aralkyl groups, C ₅ or a cycloalkyl group having C _6, aryl and C ₅ or C ₆ Or any one of C _{1 to} C ₁₈ alkyl groups substituted by R ₁ , R ₂ , Metal, x and y have the same meaning as in formula (1) according to claim 1. The monoazo metal complex represented by this. An azo pigment dispersant containing the monoazo metal complex according to claim 1 as an active ingredient. A pigment composition comprising an organic pigment, the azo pigment dispersant according to claim 3 and a resin pigment dispersant. The pigment composition according to claim 4, wherein the resin-type pigment dispersant is cationic. The pigment composition according to claim 5, wherein the resin-type pigment dispersant has an acrylic or polyester skeleton. The pigment composition according to claim 4, wherein the amount of the azo pigment dispersant added to the organic pigment is 0.1 to 50% by mass. The pigment composition according to claim 4, wherein the organic pigment is a yellow pigment having a structure based on barbituric acid. The organic pigment is C.I. I. The pigment composition according to claim 7, which is CI Pigment Yellow No. 139, No. 150 or No. 185.