JP2011032438A - Pigment dispersant, pigment composition and colorant for color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment dispersant making it possible to produce a stable ink or the like excellent in fluidity by preventing aggregation of pigment particles dispersed in the ink or the like. <P>SOLUTION: The pigment dispersant comprises a compound expressed by general formula (I), a metal salt, ammonium salt or amine salt thereof. (In the formula, X represents H, a halogen atom or an alkyl; R<SB>1</SB>represents H, an alkyl, aryl or aralkyl; R<SB>2</SB>represents an aralkyl which may contain a substituent; n represents 0.5-2, an average introduced number of sulfonic acid groups into the compound). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pigment dispersant and a pigment composition using the same.

  Generally, when a pigment is mixed and dispersed in a vehicle such as paint, gravure ink, offset ink or the like, it is difficult to stably disperse the pigment in the vehicle. Fine pigment particles once dispersed in the vehicle are There is a tendency to agglomerate in the vehicle. As a result, the viscosity of the vehicle in which the pigment is dispersed is increased, or the coloring power of the ink or paint using the vehicle in which the pigment is dispersed is decreased, or the gloss of the coating film is decreased. Will occur. That is, development of pigment dispersions and recording inks excellent in dispersion stability and fluidity is required (Patent Documents 1 and 2).

JP 2001-172522 A JP 2001-271004 A

  Accordingly, the object of the present invention is to provide printing ink (offset ink, gravure ink, etc.), various paints, pigment printing agents, electrophotographic dry toner or wet toner, ink jet recording ink, thermal transfer recording ink, writing instrument ink, By providing a pigment dispersant that prevents the aggregation of pigment particles dispersed in these inks and the like, and has excellent fluidity and enables stable production of the above inks, etc., in the production of color filters and the like. is there.

  The above object is achieved by the present invention described below. That is, the present invention relates to a pigment dispersant (hereinafter simply referred to as “dispersant”) characterized by comprising a compound represented by the following general formula (I), a metal salt thereof, or an ammonium salt or an amine salt thereof: A pigment composition using the same is provided.

（ただし、一般式（Ｉ）中のＸは水素原子、ハロゲン原子またはアルキル基であり、Ｒ₁は水素原子、アルキル基、アリール基またはアラルキル基であり、Ｒ₂はアラルキル基であって、これらは置換基を含んでいてもよく、ｎは化合物へのスルホン酸基の平均導入個数であり、０．５〜２の数である。）

(However, X in the general formula (I) is a hydrogen atom, a halogen atom or an alkyl group, R ₁ is a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, R ₂ is an aralkyl group, and May contain a substituent, and n is the average number of sulfonic acid groups introduced into the compound, and is a number between 0.5 and 2.)

  The dispersant of the present invention includes printing ink (offset ink, gravure ink, etc.), various paints, plastic, pigment printing agent, electrophotographic dry toner or wet toner, ink jet recording ink, thermal transfer recording ink, color filter resist. , For all vehicles in various applications such as ink for writing instruments, all pigments, including organic pigments and inorganic pigments, remarkably improve the fluidity of inks and paints, and prevent the aggregation of pigment particles. It is possible to provide colored articles that exhibit high gloss and sharpness.

  Next, the present invention will be described in more detail with reference to preferred embodiments. The dispersant of the present invention is characterized by having a yellow to magenta anthraquinonylaminotriazine structure in its structure, and the dispersant of the present invention has excellent affinity for various pigments. It can be used to disperse a wide range of pigments. Moreover, since the dispersing agent of this invention has the outstanding pigment dispersion effect, it can be used for manufacture of the coloring agent used in various uses.

  The dispersant of the present invention can be produced, for example, by the production method disclosed in JP-B-46-33232, JP-B-46-33233, JP-B-46-34518, or the like, or a method analogous thereto. it can. For example, in the dispersant represented by the general formula (I), 2 mol of 1-aminoanthraquinone which may have a substituent and 1 mol of cyanuric chloride are mixed with an inert solvent such as o-dichlorobenzene. The reaction is carried out at 130 ° C to 170 ° C for 2 to 6 hours, 1 mol of an aromatic amine having no sulfonic acid group is added, and the reaction is carried out at 150 ° C to 170 ° C for 3 to 4 hours. It can be obtained by sulfonation with a sulfonating agent such as

  Examples of the aromatic amine used for the production of the compound of the general formula (I) include benzylamine, dibenzylamine, phenethylamine and the like.

  Examples of the metal that forms a metal salt with the compound represented by the general formula (I) include, for example, alkali metals such as Li, Na, and K, and many metals such as Ca, Ba, Al, Mn, Sr, Mg, and Ni. Valent metals. Examples of the amine that forms an amine salt with the compound represented by the general formula (I) include ammonia, (mono, di, or tri) alkylamines, substituted or unsubstituted alkylenediamines, alkanolamines, Examples thereof include alkyl ammonium chloride.

  The mixing ratio of the dispersant of the present invention to the pigment is preferably 0.05 to 40 parts by mass, more preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the pigment. If the blending ratio of the dispersant is too small, it is difficult to sufficiently obtain the effect of the intended dispersant. Also, if the blending ratio of the dispersant is too large, the effect of using only a large amount cannot be obtained, and conversely, as a result, the physical properties of the paint or ink vehicle using the obtained pigment composition are reduced, and further, The color of the pigment to be dispersed greatly changes depending on the color of the dispersant itself.

  Examples of pigments that can be dispersed by using the dispersant of the present invention include azo pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, dianthraquinonyl pigments, isoindolinone pigments, perylene / perinone. Pigments, dioxazine pigments, indanthrone pigments, flavanthrone pigments, ansanthrone pigments, pyranthrone pigments, diketopyrrolopyrrole pigments, vat dyes, basic dyes and other organic pigments, And inorganic pigments such as titanium oxide, carbon black, bitumen, ultramarine blue, dial, iron black, zinc white, yellow lead, and complex oxide pigments. Among these, a pigment selected from C.I. Pigment Red 245, C.I. Pigment Red 254, C.I. Pigment Red 177, C.I. Pigment Green 36, C.I. Pigment Green 7 and C.I. Pigment Green 58 is particularly preferable.

Further, the method of using the dispersant of the present invention is not particularly limited, and examples thereof include the following methods.
1. The pigment and the dispersant are mixed in advance by a known method, and the obtained pigment composition is added to a vehicle or the like to disperse the pigment in the vehicle.
2. When the pigment is dispersed in the vehicle or the like, the pigment and the dispersant are separately added to the vehicle or the like at a predetermined ratio and dispersed in the vehicle.
3. After the pigment and the dispersant are separately dispersed in a vehicle or the like, the obtained dispersions are mixed at a predetermined ratio.
4). A dispersant is added at a predetermined ratio to a dispersion obtained by dispersing the pigment in a vehicle or the like to disperse the pigment. Any of these methods can achieve the desired pigment dispersion effect. However, the above method 1 or 2 is more effective.

  The pigment composition containing the dispersant of the present invention can be produced by mixing the pigment and the dispersant by various conventionally known methods, and the production method is not particularly limited. For example, pigment powder and dispersant powder are mixed without using a disperser; pigment and dispersant are mechanically mixed with various dispersers such as a kneader, roll, and attritor; water-based or organic A method in which a liquid in which the dispersant of the present invention is dissolved or finely dispersed is added to and mixed with a pigment suspension such as a solvent system, and the dispersant is uniformly deposited on the surface of the pigment; There is a method of co-precipitating both with a poor solvent such as water after dissolving the pigment and the dispersant. Thus, when preparing the pigment composition, the dispersant may be used in any form of solution, slurry, paste and powder, and any form can exhibit the effects of the present invention.

  In addition, the dispersant of the present invention can be used alone or in combination of two or more, and conventionally known dispersants, for example, rosin, polymer dispersant, surfactant, or pigment into which a polar group is introduced. It can also be used in combination with a derivative. The use of the pigment composition of the present invention is not particularly limited. For example, various printing inks, paints, plastics, pigment printing agents, electrophotographic dry toners or wet toners, ink jet recording inks, thermal transfer recording inks, and writing instruments. It can be used as a colorant for various uses such as inks and color filters. In particular, the pigment composition of the present invention is useful as a colorant for color filters that require high dispersibility of the pigment.

  In general, colorants for color filters use pigments such as photosensitive polyacrylate resins, photosensitive polyamide resins, photosensitive polyimide resins, or photosensitive resin varnishes such as unsaturated polyester resins, or the like. Further, it is produced by highly dispersing in a varnish to which a monomer as a reaction diluent is added. At that time, by using the dispersant of the present invention or the pigment composition of the present invention, a colorant for color filters having high dispersion stability and high transmittance can be obtained. For example, Japanese Patent Laid-Open No. 10-338832 describes that a pigment derivative and a cationic polymer dispersant are blended into a pigment and used as a colorant for a color filter. By using the dispersant of the present invention, a color filter colorant having high pigment dispersion stability and high transmittance can be produced.

  Specific examples of the compound represented by formula (I) are shown below. However, the present invention is not limited to these.

  Next, the present invention will be described more specifically with reference to synthesis examples, examples and comparative examples. In the text, “part” or “%” is based on mass.

[Synthesis Example 1]
73 parts of 1-aminoanthraquinone and 30 parts of cyanuric chloride are added to 1,100 parts of o-dichlorobenzene and stirred at 170 ° C. for 5 hours. After cooling, 30 parts of benzylamine is added and stirred at 180 ° C. for 5 hours. After cooling, it was filtered, washed with alcohol, then washed with water and dried to obtain 92 parts of 2,4-bis (1-anthraquinonylamino) -6-benzylamino-1,3,5-triazine. Next, 92 parts of this compound is added to 800 parts of 5% fuming sulfuric acid at 10 ° C. or lower, and then reacted at 30 ° C. for 5 hours. After cooling, the reaction mixture was precipitated into 2,500 parts of ice water, filtered and washed with water. From the result of elemental analysis of sulfur, 99 parts of the following dispersant (A) having 0.9 sulfonic acid groups introduced on average per molecule was obtained.

[Synthesis Example 2]
73 parts of 1-aminoanthraquinone and 30 parts of cyanuric chloride are added to 1,100 parts of o-dichlorobenzene and stirred at 170 ° C. for 5 hours. After cooling, 25 parts of dibenzylamine are added and stirred at 180 ° C. for 5 hours. After cooling, the mixture was filtered, washed with alcohol, then washed with water and dried to obtain 94 parts of 2,4-bis (1-anthraquinonylamino) -6-dibenzylamino-1,3,5-triazine. Next, 94 parts of this compound is added to 800 parts of 5% fuming sulfuric acid at 10 ° C. or lower, and then reacted at 30 ° C. for 5 hours. After cooling, the reaction mixture was precipitated into 2,500 parts of ice water, filtered and washed with water. From the result of elemental analysis of sulfur, 105 parts of the following dispersant (B) having an average of 1.8 sulfonic acid groups introduced per molecule was obtained.

[Examples 1 and 2]
In order to evaluate the effect of the dispersant of the present invention, a gravure ink having the following formulation (1) was prepared.
Formulation (1)
-9.5 parts of pigment-0.5 part of dispersant (A) or (B)-16.0 parts of nitrified cotton varnish-20.0 parts of polyamide varnish-54.0 parts of naphthol AS monoazo pigment (CIPigment Red 146), and using the dispersant (A) (Example 1) or (B) (Example 2) obtained in Synthesis Examples 1 and 2, respectively, the above ingredients were placed in a container and glass Beads were added and dispersed with a paint conditioner to prepare two types of gravure polyamide inks.

[Comparative Example 1]
Except for using 10.0 parts of CIPigment Red 146 without using a dispersant, the same operation as in Examples 1 and 2 was performed to prepare a polyamide ink for gravure to which no dispersant was added.

  The viscosity of the polyamide ink for gravure of Examples 1 and 2 and the gloss of the color development surface coated with the ink were compared with those of the ink of Comparative Example 1. The viscosity of each ink and the gloss of the color development surface were measured according to the following method, and the relative evaluation with the ink of Comparative Example 1 was performed.

Viscosity: measured using a B-type viscometer at room temperature (25 ° C.) and 30 rpm.
Gloss: A bar coater (winding thickness: 0.15 mm) was used to develop color on a polypropylene film, and the gloss of the developed surface was compared visually and with a gloss meter. In addition, the thing with high gloss was made favorable and displayed with the following parameter | index.
○: Good Δ: Slightly good ×: Poor The results are shown in Table 2.

[Example 3 (Preparation of pigment composition 1)]
Add 19.0 parts of CIPigment Red 146 to 1,000 parts of water and disperse to make a slurry. Thereto is added a slurry of 1.0 part of the dispersant (A) obtained in Synthesis Example 1 and 0.1 part of caustic soda in 50 parts of water. The mixed slurry is heated to 70 ° C. and the pH is corrected to 4-5. After stirring for 20 minutes, it was filtered, dried and pulverized to obtain 19.9 parts of the pigment composition (1) of the present invention. Gravure polyamide ink (1) was prepared in the same manner as in Example 1 except that 10.0 parts by weight of the pigment composition (1) was used in the formulation (1) of Examples 1 and 2. Produced.

[Example 4 (Preparation of pigment composition 2)]
A pigment composition (2) was obtained in the same manner as in Example 3 except that the dispersant (B) obtained in Synthesis Example 2 was used instead of the dispersant (A). A gravure polyamide ink (2) was prepared in the same manner as in Example 1 and 2, except that the total amount of the pigment and dispersant in the formulation (1) was changed to 10.0 parts of the pigment composition (2). .

  For these inks (1) and (2), the viscosity of the ink and the gloss of the color development surface were compared with those of the ink of Comparative Example 1 in the same manner as in Example 1. The results are shown in Table 2.

  As shown in Table 2, excellent pigment dispersion effects were observed in the inks (1) and (2) to which the dispersants (A) and (B) of the present invention were added. Even when the viscosity of these inks (1) and (2) was measured after standing for 1 week, almost no increase in viscosity was observed compared to the ink of Comparative Example 1. Further, not only as a pigment composition but also when a mixture of a vehicle and a pigment and a dispersant added separately was mixed and dispersed, the effect of a sufficient dispersant was obtained as described above.

[Examples 5 and 6 (Preparation of pigment compositions 3 and 4)]
The same procedure as in Example 3 was repeated, except that a diketopyrrolopyrrole pigment (CIPigment Red254) was used instead of CIPigment Red 146, and the dispersants (A) and (B) were used, respectively, and a pigment composition (3) And (4) were obtained.

[Examples 7 and 8 (Preparation of pigment compositions 5 and 6)]
The same procedure as in Example 3 was repeated, except that copper phthalocyanine green pigment (CIPigmentGreen 36) was used instead of CIPigment Red 146, and dispersants (A) and (B) were used, respectively, and pigment composition (5) and (6) was obtained.

In order to evaluate the effect of the dispersant using the above pigment compositions (3) to (6), a gravure urethane ink having the following composition (2) was prepared.
Formula (2)
・ Pigment compositions (3) to (6) 10.0 parts ・ Nitrified cotton varnish 5.0 parts ・ Polyurethane varnish 35.0 parts ・ Thinner 50.0 parts Add the above ingredients into a container and add steel balls. It was dispersed with a paint conditioner to prepare gravure urethane inks (3) to (6).

[Comparative Examples 2 and 3]
In place of the pigment compositions (3) and (5), the dispersant was not used in the same manner as in Examples 5 and 7, except that CIPigment Red 254 (Comparative Example 2) and CIPigment Green 36 (Comparative Example 3) were used. Two kinds of urethane inks for gravure were prepared.

  The inks of Examples 5 to 8 were compared with the inks of Comparative Examples 2 and 3 in terms of ink viscosity and color development gloss. The gloss of the color development surface and the viscosity of the ink were measured in the same manner as in the case of the polyamide ink for gravure, and the relative evaluation was performed as in the case of the inks of Comparative Examples 2 and 3. The results are shown in Table 3.

  As shown in Table 3, as in the case of the gravure polyamide ink, when any of the dispersants (A) and (B) of the present invention was added, a dispersion effect was recognized although there was a slight difference. . Even when the viscosity of the ink of the example was measured after standing for 1 week, an increase in the viscosity was hardly observed as compared with the case of the ink of the comparative example.

[Examples 9 and 10 (Preparation of pigment compositions 7 to 8)]
The same operations as in Example 3 were repeated except that CIPigment Red 177 was used instead of CIPigment Red 146 and dispersants (A) and (B) were used as dispersants, respectively, and pigment compositions (7) and (8) )

In order to evaluate the effect of the dispersant using these pigment compositions (7) and (8), a paint having the following composition (3) was prepared.
Formula (3)
-Pigment compositions (7) and (8) 6.0 parts-Acrylic varnish 46.6 parts-Melamine varnish 20.0 parts-Thinner 30.0 parts Add the above ingredients into a container and add glass beads. A paint was prepared by dispersing with a paint conditioner.

[Comparative Example 4]
A paint not added with a dispersant was prepared in the same manner as in Example 9 except that 10.0 parts of CIPigment Red 177 was used instead of 10.0 parts of the pigment composition (7).

  The viscosities of these paints, and color development and gloss of the coated surface after baking were compared with those of the comparative paints. The viscosity of the paint and the gloss of the color development surface were measured according to the following method, and the relative evaluation with the paint of the comparative example was performed.

Viscosity: measured using a B-type viscometer under conditions of room temperature (25 ° C.) and 30 rpm.
Gloss: Using an applicator (6 mils), the gloss of the coated surface after color development and baking on an art paper was compared visually and with a gloss meter. In addition, the thing with high gloss was made favorable and displayed with the following parameter | index.
○: Good Δ: Slightly good ×: Poor Table 4 shows the above results.

  As shown in Table 4, the effect of the dispersant of the present invention was recognized as in the above results. Although the paint of the above example was a light-colored paint diluted with a white paint made of titanium oxide to a concentration of 1/10 and observed the aggregation state of the pigment, no color separation or sedimentation of the pigment was observed. It was.

[Examples 11 and 12]
In order to evaluate the effect of the dispersant using the pigment compositions (7) and (8), a color filter colorant having the following formulation (4) was prepared.
Formula (4)
-Pigment composition (7) or (8) 20.0 parts-Polyacrylic acid resin 30.0 parts-Thinner 50.0 parts Add the above ingredients into a container, add zirconia beads, and disperse with paint conditioner. A color filter colorant was prepared.

[Comparative Example 5]
Pigment composition (7) Instead of 10.0 parts, except for using 10.0 parts of CIPigment Red 177, the same operation as in Example 11 was performed to obtain a color filter colorant to which no dispersant was added. Produced.

  The fluidity of the colorant for color filter and the gloss of the color development surface of the examples and comparative examples were compared with those of the comparative example. The fluidity of the colorant and the gloss of the color development surface were measured according to the following method, and the relative evaluation was performed as in the case of the comparative example.

Flowability: Measured using a B-type viscometer under conditions of room temperature (25 ° C.) and 30 rpm.
Gloss: Using a bar coater (winding thickness: 0.45 mm), the film was developed on a polypropylene film, and the gloss of the developed surface was compared visually and with a gloss meter. In addition, the thing with high gloss was made favorable and displayed with the following parameter | index.
○: Good Δ: Slightly good ×: Poor Table 5 shows the above results.

  As shown in Table 5, the colorant using the dispersant of the present invention showed higher fluidity than the comparative example, and the effect of the dispersant of the present invention was recognized.

  Furthermore, the pigment added with the dispersant of the present invention was used for printing inks such as offset inks, various paints such as nitrocellulose lacquer and melamine alkyd paints, and coloring synthetic resins such as vinyl chloride resins. However, the pigment did not aggregate and showed good dispersibility. Recently, the dispersant of the present invention has been used in the production of dry or wet toners for electrophotography, ink for ink jet recording, ink for thermal transfer recording, ink for writing instruments, etc., for which high dispersibility is particularly required. Also in this case, an excellent dispersibility effect by the dispersant of the present invention was recognized.

  The dispersant of the present invention includes printing ink (offset ink, gravure ink, etc.), various paints, plastic, pigment printing agent, electrophotographic dry toner or wet toner, ink jet recording ink, thermal transfer recording ink, color filter resist. , For all vehicles in various applications such as ink for writing instruments, all pigments, including organic pigments and inorganic pigments, remarkably improve the fluidity of inks and paints, and prevent the aggregation of pigment particles. It is possible to provide colored articles that exhibit high gloss and sharpness.

Claims (8)

A pigment dispersant comprising a compound represented by the following general formula (I), a metal salt thereof, an ammonium salt or an amine salt thereof.

(However, X in the general formula (I) is a hydrogen atom, a halogen atom or an alkyl group, R ₁ is a hydrogen atom, an alkyl group, an aryl group or an aralkyl group, R ₂ is an aralkyl group, and May contain a substituent, and n is the average number of sulfonic acid groups introduced into the compound, and is a number between 0.5 and 2.)   A pigment composition comprising a pigment and a dispersant, wherein the dispersant is the pigment dispersant according to claim 1.   The pigment composition according to claim 2, wherein the mixing ratio of the dispersant is 0.05 to 40 parts by mass with respect to 100 parts by mass of the pigment.   The pigment composition according to claim 2, wherein the pigment is a pigment selected from C.I. Pigment Red 245, C.I. Pigment Red 254, C.I. Pigment Red 177, C.I. Pigment Green 36, C.I. Pigment Green 7 and C.I. Pigment Green 58.   The pigment composition according to claim 2, which is a colorant for gravure printing ink.   The pigment composition according to claim 2, which is a paint colorant.   The pigment composition according to claim 2, which is a colorant for a color filter.   The colorant for color filter according to claim 7, wherein the pigment composition according to claim 2 is contained in the photosensitive resin varnish.