JP2018119069A - Pigment dispersant, pigment composition, and pigment colorant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pigment dispersant from which a colored article can be produced, where the colored article can remarkably improve flowability of ink, a coating material or the like containing a pigment, can prevent particle aggregation of the pigment, prevents occurrence of a foreign substance, exhibits excellent glossiness and clarity, and prevents brightness and a contrast ratio from lowered even when subjected to high temperature treatment of 230°C or higher at the time of color filter production.SOLUTION: A pigment dispersant is a compound represented by general formula (1) (A: t-butyl group or the like, B: hydrogen atom or the like, C: hydroxyl group or the like, R: straight-chain alkylene group having 1 to 4 carbon atoms or the like, and X: specific liking group), a quaternary ammonium salt thereof, an amine salt thereof or a metal salt thereof.SELECTED DRAWING: None

Description

  The present invention relates to a pigment dispersant, a pigment composition, and a pigment colorant.

  In general, it is difficult to stably disperse pigments in vehicles such as paints and inks. The fine pigment particles once dispersed in the vehicle tend to aggregate in the vehicle, and the vehicle in which the pigment particles aggregate has a problem that the viscosity increases. In addition, when a vehicle in which aggregated pigment particles are dispersed is used, various problems such as a reduction in the coloring power of inks and paints and a reduction in the gloss of coating films are likely to occur.

  On the other hand, pigments for color filters used for liquid crystal displays, image sensors, and the like are required to have high brightness and contrast ratio of transmitted light of colored pixels, and therefore, measures for miniaturization are taken. If a color filter is produced using a pigment colorant having high viscosity or agglomeration of pigments and exhibiting thixotropic viscosity, the central portion of the colored film before exposure may be raised. For this reason, there arises a problem that unevenness of hue or density difference occurs between the pixel located in the central portion of the substrate and the pixel located in the peripheral portion. Therefore, for pigment colorants for producing color filters, the pigment dispersion state is good while containing a high concentration of pigment, and it is low compared to ordinary ordinary dry paints and baking paints. Viscosity is required. Generally, even when the pigment concentration is 5 to 20% by mass, the pigment is not aggregated, the viscosity is about 5 to 20 mPa · s, and the storage stability is required to be good.

  Moreover, the problem that heat resistance falls by making a pigment fine is easy to arise. In the manufacturing process of a color filter, the heat processing which heats to 200 degreeC or more, Preferably it heats to 230 degreeC and bakes and hardens | cures a coating are required. For this reason, a pigment colorant for producing a color filter is required to have high heat resistance such that the decrease in luminance and contrast ratio is small even when heat treatment is performed.

  In order to satisfy the above requirements, conventionally, a method of adding a pigment derivative as a pigment dispersant, a method of treating a pigment with a pigment derivative, and the like have been proposed. Specifically, when a phthalocyanine blue such as PB15: 6 is used as a pigment, it has been proposed to use a substituted derivative of phthalocyanine as a pigment dispersant. Further, when an anthraquinone red such as PR177 is used as a pigment, it has been proposed to use a substituted derivative of anthraquinone as a pigment dispersant. Moreover, when using diketopyrrolopyrrole-type red, such as PR254, as a pigment, using the substituted derivative of diketopyrrolopyrrole as a pigment dispersant is proposed (for example, refer patent documents 1-4).

JP 2002-055224 A JP 2001-240780 A JP 2009-029886 A JP 2004-091497 A

  However, with the techniques proposed in Patent Documents 1 to 4 and the like, it has been difficult to obtain a pigment colorant for producing a color filter that satisfies the above requirements.

  The present invention has been made in view of such problems of the prior art, and the problem is that the fluidity of pigment-containing inks and paints can be remarkably improved, and Coloring that can prevent particle agglomeration, prevents the generation of foreign matters, exhibits excellent gloss and sharpness, and does not easily lower the luminance and contrast ratio even at high temperatures of 230 ° C. or higher during color filter production It is to provide a pigment dispersant capable of producing an article. Moreover, the place made into the subject of this invention is providing the pigment composition and pigment colorant which are obtained using the said pigment dispersant.

That is, according to the present invention, the following pigment dispersant is provided.
[1] A pigment dispersant which is a compound represented by the following general formula (1), a quaternary ammonium salt thereof, an amine salt thereof, or a metal salt thereof.

（前記一般式（１）中、Ａは水素原子、メチル基、又はｔ−ブチル基を示し、Ｂは水素原子又はメチル基を示し、Ｃは塩素原子、水酸基、又は５−アミノベンズイミダゾロン基を示し、Ｒは単結合又は炭素数１〜４の直鎖状のアルキレン基を示し、Ｘは下記一般式（２−１）〜（２−４）のいずれかで表される連結基を示す）

(In the general formula (1), A represents a hydrogen atom, a methyl group, or a t-butyl group, B represents a hydrogen atom or a methyl group, and C represents a chlorine atom, a hydroxyl group, or a 5-aminobenzimidazolone group. R represents a single bond or a linear alkylene group having 1 to 4 carbon atoms, and X represents a linking group represented by any one of the following general formulas (2-1) to (2-4). )

（前記一般式（２−１）〜（２−４）中、Ｚは、それぞれ独立に低級アルキル基を示し、ｐは、それぞれ独立に０〜４の整数を示す。前記一般式（２−２）〜（２−４）中、Ｙは、それぞれ独立に−ＣＨ₂−、−Ｃ（ＣＨ₃）₂−、−Ｏ−、又は−ＳＯ₂−を示す）

(In the general formulas (2-1) to (2-4), each Z independently represents a lower alkyl group, and each p independently represents an integer of 0 to 4. The general formula (2-2 ) in ~ (2-4), Y is, -CH ₂ each independently _{-, - C (CH 3)} 2 -, - shows a) - O-, or -SO ₂

Moreover, according to this invention, the pigment composition shown below is provided.
[2] A pigment composition containing the pigment dispersant according to [1] and a pigment.
[3] The pigment composition according to [2], wherein the blending amount of the pigment dispersant is 0.5 to 40 parts by mass with respect to 100 parts by mass of the pigment.

Furthermore, according to the present invention, the following pigment colorants are provided.
[4] A pigment colorant containing the pigment composition according to the above [2] or [3] and a film-forming material.
[5] The pigment colorant according to the above [4], which is for image display, image recording, printing ink, writing ink, plastic, pigment printing, or paint.
[6] The pigment colorant according to [4], which is used for a color filter.

  The pigment dispersant of the present invention can remarkably improve the fluidity of pigment-containing inks and paints, and can prevent pigment particles from agglomerating, while preventing the occurrence of foreign substances, It is possible to produce a colored article that exhibits sharpness and that does not easily decrease in luminance and contrast ratio even by a high-temperature treatment at 230 ° C. or higher during the production of a color filter. Therefore, the pigment dispersant of the present invention includes printing inks such as offset inks and gravure inks, various paints, plastics, pigment printing agents, electrophotographic dry or wet toners, ink jet recording inks, thermal transfer recording inks, and color filters. It can be suitably used for vehicles used for resists for printing, ink for writing instruments, and the like.

  In addition, if the pigment dispersant of the present invention is used, a pigment composition that can remarkably improve the fluidity of various paints, prevent pigment particle aggregation, and form a colored film in which the generation of foreign matters is effectively prevented. And pigment colorants can be provided. Furthermore, the pigment colorant of the present invention is less susceptible to thickening and gelation during storage, and can produce a colored product having excellent gloss and sharpness. In particular, even when the treatment is performed at a high temperature of 230 ° C. or higher, the luminance and contrast ratio are not easily lowered, and a high-luminance colored product can be produced. For this reason, the pigment colorant of the present invention is particularly suitable as a pigment colorant for color filters.

<Pigment dispersant>
Hereinafter, the details of the present invention will be described with reference to preferred embodiments. One of the main characteristics of the pigment dispersant of the present invention is that it is a compound represented by the following general formula (1), a quaternary ammonium salt thereof, an amine salt thereof, or a metal salt thereof. The pigment dispersant of the present invention having such characteristics has excellent affinity for various pigments, and is suitable as a pigment dispersant for dispersing various pigments regardless of organic or inorganic. Can be used for Further, since the pigment dispersant of the present invention has an excellent pigment dispersion effect, it can be used as a material for preparing pigment colorants for various uses.

（前記一般式（１）中、Ａは水素原子、メチル基、又はｔ−ブチル基を示し、Ｂは水素原子又はメチル基を示し、Ｃは塩素原子、水酸基、又は５−アミノベンズイミダゾロン基を示し、Ｒは単結合又は炭素数１〜４の直鎖状のアルキレン基を示し、Ｘは下記一般式（２−１）〜（２−４）のいずれかで表される連結基を示す）

(In the general formula (1), A represents a hydrogen atom, a methyl group, or a t-butyl group, B represents a hydrogen atom or a methyl group, and C represents a chlorine atom, a hydroxyl group, or a 5-aminobenzimidazolone group. R represents a single bond or a linear alkylene group having 1 to 4 carbon atoms, and X represents a linking group represented by any one of the following general formulas (2-1) to (2-4). )

（前記一般式（２−１）〜（２−４）中、Ｚは、それぞれ独立に低級アルキル基を示し、ｐは、それぞれ独立に０〜４の整数を示す。前記一般式（２−２）〜（２−４）中、Ｙは、それぞれ独立に−ＣＨ₂−、−Ｃ（ＣＨ₃）₂−、−Ｏ−、又は−ＳＯ₂−を示す）

(In the general formulas (2-1) to (2-4), each Z independently represents a lower alkyl group, and each p independently represents an integer of 0 to 4. The general formula (2-2 ) in ~ (2-4), Y is, -CH ₂ each independently _{-, - C (CH 3)} 2 -, - shows a) - O-, or -SO ₂

  In the general formula (1), examples of the linear alkylene group having 1 to 4 carbon atoms represented by R include a methylene group, an ethylene group, an n-propylene group, and an n-butylene group. . In the general formulas (2-1) to (2-4), examples of the lower alkyl group represented by Z include C1-C4 such as methyl group, ethyl group, propyl group, and butyl group. An alkyl group can be mentioned. These lower alkyl groups may be linear or branched.

  Even when a pigment colorant blended with a commercially available additive such as an antioxidant is used, the brightness of the resulting colored product is likely to decrease when treated at a high temperature of 230 ° C. or higher. This is because a general additive such as an antioxidant is a low molecular weight compound, which makes it difficult to continue to exist in the vicinity of the pigment due to bleeding out, extraction, and diffusion into a dispersion medium. This is probably because the effect of the additive becomes insufficient. On the other hand, the pigment dispersant of the present invention is a relatively high molecular weight compound having a structure in which a hindered phenol group and a sulfonic acid group are introduced into a portion adsorbed on the pigment. For this reason, it is easy to adsorb | suck to the surface of a pigment particle, and the antioxidant ability of a hindered phenol group and the dispersibility of a sulfonic acid group are exhibited effectively. As a result, it is possible to suppress a decrease in luminance even when processed at a high temperature of 230 ° C. or more while preventing aggregation of pigment particles and generation of foreign matters, so that a color filter having excellent gloss and sharpness, etc. Can be produced.

  The quaternary ammonium salt, amine salt, and metal salt of the compound represented by the general formula (1) have a pigment in the medium as compared with the compound represented by the general formula (1) (free sulfonic acid). While the function as a dispersing agent to disperse is slightly inferior, it exhibits more excellent heat resistance. Therefore, the quaternary ammonium salt, amine salt, and metal salt of the compound represented by the general formula (1) are not only used as pigment dispersants but also pigments that can impart excellent heat resistance to the pigment. More useful as a modifier. Accordingly, when a quaternary ammonium salt, an amine salt, and a metal salt of the compound represented by the general formula (1) are used as a pigment modifier, the aggregation of the pigment particles and the generation of foreign matters are prevented and the temperature of 230 ° C. or more is prevented. Even when the treatment is performed at a high temperature, a decrease in luminance can be suppressed, so that a colored product such as a color filter having excellent gloss and sharpness can be produced.

  In general formula (1), X shows the coupling group which has an amino group in the both ends represented by either of general formula (2-1)-(2-4). The linking group represented by X can be formed using a compound having amino groups at both ends. Specific examples of the compound having amino groups at both ends include 4,4′-methylenebis (2-ethyl-6-methylaniline), α, α′-bis (4-aminophenyl) -1,4-diisopropyl. Examples thereof include benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, bis (4-aminophenyl) sulfone, 1,4-phenylenediamine, and the like.

  Examples of the amine that forms an amine salt with the sulfonic acid group in the general formula (1) include (mono, di, or tri) alkylamines, substituted or unsubstituted alkylenediamines, alkanolamines, alkylammonium chlorides, and the like. Can be mentioned. Of these, quaternary ammonium salts are preferred. Examples of the metal that forms a metal salt with the sulfonic acid group in the general formula (1) include alkali metals such as Li, Na, and K; Ca, Ba, Al, Mn, Sr, Mg, Ni, Zn, and the like. And polyvalent metals.

  The pigment dispersant of the present invention exhibits an excellent action as a pigment dispersant even in a small amount. In addition, the pigment composition and the pigment colorant prepared using the pigment dispersant of the present invention are less prone to thickening and gelation during storage, and foreign matter is generated in the coating film formed using these. Hateful. Specific examples of the pigment dispersant of the present invention include compounds represented by the following formulas (A) to (E).

  The method for producing (synthesizing) the compound (pigment dispersant) represented by the general formula (1) will be described by taking the compound represented by the above formula (B) as an example. In order to synthesize the compound represented by the above formula (B), first, 1 equivalent of sulfanilic acid and 1 equivalent of 1,4-phenylenediamine are reacted at 60 to 80 ° C. with respect to cyanuric chloride. obtain. Subsequently, the obtained intermediate and an acid chloride having a hindered phenol group such as 3-equivalent 3- (3,5-di-tert-butyl-4-hydroxybenzene) propionic acid chloride were mixed at 90 to 120 ° C. The compound (pigment dispersing agent) represented by General formula (1) can be obtained by making it react by. In order to produce a pigment dispersant other than the compound represented by the formula (B), for example, instead of 1,4-phenylenediamine, a corresponding compound having an amino group at both ends is used. May be the same as the synthesis example of the compound represented by the above formula (B).

  The acid chloride having a hindered phenol group can be synthesized from, for example, a carboxylic acid compound having a hindered phenol group. The pigment dispersant of the present invention may contain a small amount of unreacted raw material, but may contain some unreacted raw material as long as the effects of the present invention are obtained.

  Examples of the carboxylic acid compound having a hindered phenol group include 3,5-di-tert-butyl-4-hydroxybenzoic acid, 2- (3,5-di-tert-butyl-4-hydroxyphenyl) acetic acid, 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid, 4- (3,5-di-tert-butyl-4-hydroxyphenyl) butanoic acid, 5- (3,5-di-tert) -Butyl-4-hydroxyphenyl) pentanoic acid and the like. Of these, 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid is preferable.

Although the usage method in particular of the pigment dispersant of this invention is not restrict | limited, The usage method as shown below is illustrated. Whichever method is used, the desired pigment dispersion effect can be obtained.
(1) A pigment and a pigment 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) A pigment and a pigment dispersant are separately added at a predetermined ratio to a vehicle or the like, and the pigment is dispersed in the vehicle.
(3) The pigment and the pigment dispersant are separately dispersed in a vehicle or the like, and then the obtained dispersions are mixed at a predetermined ratio to disperse the pigment in the vehicle.
(4) A pigment dispersant is added at a predetermined ratio to a dispersion obtained by dispersing the pigment in a vehicle or the like, and the pigment is dispersed in the vehicle.

  In the method of (1) to (4) above, a polymer dispersion having an ionic group (counterionic group) of an ionic group counter in the compound (pigment dispersant) represented by the general formula (1) It is preferable to add and disperse the agent. In particular, in the method (1) or (2), it is desirable to disperse in combination with a polymer dispersant having a counterionic group.

<Pigment composition>
The pigment composition of the present invention contains a pigment and the pigment dispersant described above. The blending amount of the pigment dispersant with respect to 100 parts by mass of the pigment is preferably 0.5 to 40 parts by mass, and more preferably 1 to 20 parts by mass. If the amount of the pigment dispersant is less than the above range, the effect of the intended dispersant may not be sufficiently obtained. On the other hand, if the amount of the pigment dispersant is larger than the above range, the effect of the dispersant will reach its peak, and no further effect can be expected. It may become. Furthermore, in paints and inks using a pigment composition containing an excessive amount of such a pigment dispersant, the physical properties of the vehicle are reduced, or the hue of the pigment varies greatly depending on the color of the pigment dispersant itself. Sometimes.

  The pigment dispersant of the present invention may further contain a known sulfonic acid pigment derivative (acid dispersant). If the hue of the pigment colorant to be prepared is blue, it is preferable to use a phthalocyanine sulfonated product as a pigment derivative. Moreover, if the hue of the pigment colorant is red, it is preferable to use a diketopyrrolopyrrole sulfonated product, a quinacridone sulfonated product, or an anthraquinone sulfonated product as a pigment derivative. Furthermore, if the hue of the pigment colorant is yellow, it is preferable to use a sulfonated product of PY138 as the pigment derivative. Further, a basic dispersant may be used in place of the acidic dispersant.

  Specific examples of pigments that can obtain an effective dispersion effect by using the pigment dispersant of the present invention include soluble / insoluble azo pigments, high molecular weight azo pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, diketopyrrolopyrrole pigments. Quinophthalone pigment, methine / azomethine pigment, perylene pigment, perinone pigment, isoindolinone pigment, isoindoline pigment, metal complex pigment, and the like.

The method for producing the pigment composition of the present invention is not particularly limited. For example, the pigment composition of the present invention can be obtained by mixing a pigment and a pigment dispersant by a conventionally known method. Specific examples of the method for producing the pigment composition of the present invention include the following methods (1) to (4).
(1) A method of mixing a powder of a pigment and a powder of a pigment dispersant without using a disperser.
(2) A method of mechanically mixing the pigment and the pigment dispersant with various dispersing machines such as a kneader, a roll, an attritor, and a horizontal bead mill.
(3) A method of adding and mixing a liquid in which a pigment dispersant is dissolved or finely dispersed into an aqueous suspension or an organic solvent suspension of the pigment, and uniformly depositing the pigment dispersant on the surface of the pigment.
(4) A method in which a pigment and a pigment dispersant are dissolved in a solvent having strong dissolving power such as sulfuric acid and then co-precipitated with a poor solvent such as water.

  The properties of the pigment dispersant used for preparing the pigment composition may be any of solution, slurry, paste, and powder. The desired effect can be obtained even when any kind of pigment dispersant is used.

<Pigment colorant>
The pigment colorant of the present invention contains the pigment composition described above and a film forming material. The pigment colorant of the present invention mixes, for example, the above-described finely-divided pigment composition and a film-forming material such as a resin ((co) polymer), oligomer, or monomer selected according to the application. Can be obtained. The pigment colorant of the present invention can be used in a wide range of fields as a colorant for image display, image recording, printing ink, writing ink, plastic, pigment printing, paint and the like. In particular, it is suitable as an image display material in which the transparency of colored pixels is a problem, particularly as a pigment colorant for a color filter. Of course, the pigment colorant of the present invention is also useful as a material for image recording agents such as electrophotographic dry or wet toner, ink jet recording ink, electrodeposition recording liquid, thermal transfer recording ink, and writing instrument ink. These materials for image recording agents are used in various image recording methods such as an ink jet recording method, an electrodeposition recording method, and an electrophotographic method. By using the pigment colorant of the present invention, a material for an image recording agent capable of providing a high-quality image can be prepared by any image recording method.

  Hereinafter, further details of the pigment colorant of the present invention will be described using a color filter pigment dispersion (color filter (CF) pigment colorant) which is a pigment colorant for image display as a representative example. To prepare a color filter pigment dispersion (photoresist), first, the above-described pigment composition is added to a liquid containing a film-forming material and premixed. Next, if a dispersion treatment is performed, a pigment dispersion for a color filter can be obtained. More specifically, a pigment composition that has been uniformly ground using a dispersing machine such as a vertical medium disperser, a horizontal medium disperser, or a ball mill is added to and mixed with a liquid containing a film-forming material. Thus, a pigment dispersion for a color filter can be obtained. Further, a solution obtained by dissolving a pigment and a pigment dispersant in sulfuric acid or the like is mixed with water, and a pigment composition containing the pigment and the pigment dispersant is precipitated as a solid solution or a eutectoid and separated. After the separated pigment composition is added to and mixed with a liquid containing a film-forming material, a polymer dispersant, etc., it may be ground and dispersed using a horizontal wet medium disperser (bead mill) such as dyno mill. A pigment dispersion for a color filter can be obtained.

  The pigment colorant of the present invention may further contain a polymer dispersant. As the polymer dispersant, a basic polymer dispersant is preferable. The surface of the pigment in the pigment colorant of the present invention is treated with an acidic pigment dispersant represented by the general formula (1). For this reason, a pigment dispersion for color filters having a lower viscosity and a higher contrast can be obtained by containing a basic polymer dispersant. When an acidic polymer dispersant is contained, the pigment may aggregate and the pigment colorant may become thickened easily. In particular, when an acidic dispersant such as an acidic pigment derivative is contained, it is preferable to use a basic polymer dispersant. However, when a basic dispersant such as a basic pigment derivative is contained, an acidic polymer dispersant can also be used.

  A known dispersant can be used as the polymer dispersant. Specific examples of the basic polymer dispersant are the following trade names: DISPERBYK-160, 161, 162, 163, 164, 166, 171, 182, 184, 2000. 2001, 2070, 2150 (above, manufactured by Big Chemie); EFKA-44, 46, 47, 48, 4010, 4015, 4020, 4050, 4055, 4060, 4060, 4300 4330, 4400, 4406, 4510, 4800 (above, manufactured by BASF); SOLPERS-24000, 32550, NBZ-4204 / 10 (above, manufactured by Lubrizol); Hinoact T-6000, 7000 8000 (above, manufactured by Kawaken Fine Chemical Co., Ltd.); Ajisper PB-821, 822, 82 (Above, manufactured by Ajinomoto Fine-Techno Co., Inc.), and the like.

  The blending amount of the polymer dispersant is preferably 2 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 blending amount of the polymer dispersant is less than 2 parts by mass, it may be difficult to obtain good pigment dispersion stability. On the other hand, if the blending amount of the polymer dispersant exceeds 100 parts by mass, the developability of the formed film may be lowered.

  As a liquid containing a film forming material used for preparing a pigment dispersion for a color filter, a solution of a film forming polymer contained in a conventionally known pigment dispersion for a color filter can be used. Examples of the liquid medium used for the liquid containing the film forming material include an organic solvent, water, and a mixed liquid of an organic solvent and water. In addition, conventionally well-known additives, such as a dispersion | distribution adjuvant, a smoothing agent, an adhesive agent, can be added to the pigment dispersion liquid for color filters as needed.

  The amount of the pigment composition contained in the pigment colorant of the present invention is preferably 5 to 500 parts by mass, more preferably 50 to 250 parts by mass with respect to 100 parts by mass of the film forming material. Moreover, as a liquid containing a film-forming material, a liquid containing a photosensitive film-forming material or a liquid containing a non-photosensitive film-forming material can be appropriately selected and used depending on the application. Specific examples of the liquid containing the photosensitive film-forming material include a liquid containing a photosensitive film-forming material used for ultraviolet curable ink, electron beam curable ink, and the like. Specific examples of liquids containing non-photosensitive film-forming materials include varnishes used for printing inks such as letterpress inks, lithographic inks, gravure inks and screen inks; varnishes used for room temperature drying or baking paints; Examples thereof include varnishes used for coating and varnishes used for thermal transfer ribbons.

  The pigment dispersion for a color filter is required to have a good pigment dispersion state and a low viscosity as compared with general ordinary dry paints and baking paints while containing a pigment at a high concentration. In general, even when the pigment concentration is 5 to 20% by mass, the pigment is not aggregated, the viscosity is about 5 to 20 mPa · s, and the storage stability is required to be good. Therefore, when used for a color filter, the pigment dispersion of the present invention preferably satisfies the above viscosity condition. Preferably, the viscosity is 5 to 15 mPa · s, and the rate of increase in viscosity after standing for 1 month at 25 ° C. (after standing) is within 10%. When the viscosity increases, it becomes difficult to form a film with a certain thickness.

  Specific examples of photosensitive film forming materials include photosensitive cyclized rubber resins, photosensitive phenol resins, photosensitive polyacrylate resins, photosensitive polyamide resins, photosensitive polyimide resins, and unsaturated polyester resins. And photosensitive resins such as polyester acrylate resins, polyepoxy acrylate resins, polyurethane acrylate resins, polyether acrylate resins, and polyol acrylate resins. In addition, you may add various monomers as a reactive diluent to the liquid containing these photosensitive resins.

  If a photopolymerization initiator such as benzoin ether or benzophenone is added to a pigment colorant containing a photosensitive resin as a film-forming material and kneaded by a conventionally known method, a photocurable photosensitive pigment dispersion is obtained. be able to. Further, if a thermal polymerization initiator is used instead of the photopolymerization initiator, a thermosetting pigment dispersion can be obtained.

  On the other hand, specific examples of non-photosensitive film-forming materials include styrene- (meth) acrylic acid ester (co) polymers, soluble polyamide resins, soluble polyimide resins, soluble polyamideimide resins, and soluble polyesterimide resins. Resin, water-soluble salt of styrene-maleic acid ester copolymer, water-soluble salt of (meth) acrylic acid ester- (meth) acrylic acid copolymer, water-soluble aminopolyester resin, and water-soluble resin Mention may be made of salts.

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

<Preparation of pigment dispersant>
Example 1
To 1200 parts of water, 36.9 parts of cyanuric chloride and 34.6 parts of sulfanilic acid were added and stirred at room temperature for 1 hour. 56.5 parts of 4,4′-methylenebis (2-ethyl-6-methylaniline) was added and stirred at 75 ° C. for 1 hour. After standing to cool, it was filtered, washed with water, and dried to obtain 111.6 parts of an intermediate. To 70 parts of dimethylacetamide, 13.9 parts of 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionic acid and 6.5 parts of thionyl chloride are added, and the mixture is heated at 40 to 50 ° C. for 0.5 hour. Stir. 28.3 parts of the intermediate obtained above was added and stirred at 120 to 130 ° C. for 3 hours. After standing to cool, it was put into 700 parts of water, filtered, washed with water and dried to obtain 40.3 parts of a pigment dispersant (A) represented by the following formula (A).

(Example 2)
In the same manner as in Example 1 except that 21.6 parts of p-phenylenediamine was used instead of 56.5 parts of 4,4′-methylenebis (2-ethyl-6-methylaniline), the following: 45.7 parts of pigment dispersant (B) represented by the formula (B) was obtained.

(Example 3)
The same as Example 1 except that 49.7 parts of bis (4-aminophenyl) sulfone was used instead of 56.5 parts of 4,4′-methylenebis (2-ethyl-6-methylaniline). Thus, 40.6 parts of a pigment dispersant (C) represented by the following formula (C) was obtained.

Example 4
Instead of 56.5 parts of 4,4′-methylenebis (2-ethyl-6-methylaniline), 68.92 parts of α, α′-bis (4-aminophenyl) -1,4-diisopropylbenzene was used. Except for this, 39.2 parts of pigment dispersant (D) represented by the following formula (D) was obtained in the same manner as in Example 1 described above.

(Example 5)
Other than using 82.12 parts of 2,2-bis [4- (4-aminophenoxy) phenyl] propane instead of 56.5 parts of 4,4′-methylenebis (2-ethyl-6-methylaniline) Obtained 38.2 parts of pigment dispersant (E) represented by the following formula (E) in the same manner as in Example 1 described above.

When each compound (pigment dispersant) obtained in Examples 1 to 5 was subjected to mass spectrometry by MALDI (abbreviation for matrix-assisted laser desorption / ionization method), peaks corresponding to the following molecular weights were detected. From the raw materials used and the results of mass spectrometry, it was confirmed that the compound (pigment dispersant) having the target composition was obtained.
Compound (A): molecular weight 809.05, S analysis value: calculated value 3.96%, actual value% 3.95%
Compound (B): molecular weight 634.76, S analysis value: calculated value 4.97%, actual value% 5.00%
Compound (C): molecular weight 774.94, S analysis value: calculated value 4.13%, actual value% 4.12%
Compound (D): molecular weight 871.12, S analysis value: calculated value 3.67%, actual value% 3.67%
Compound (E): molecular weight 937.14, S analysis value: calculated value 3.41%, actual value% 3.44%

<Preparation of pigment compositions (1) to (5)>
(Example 6)
2,000 parts of water was added to a press cake of PY138 (solid content concentration: 37%) weighed so that the pigment content would be 100 parts, and sufficiently reslurried to obtain a slurry. To 100 parts of water, 5 parts of the pigment dispersant (A) obtained in Example 1, 5 parts of PY138 monosulfonate, and 1 part of sodium hydroxide were dispersed to form a slurry. This mixed slurry was heated to 70 ° C., and 1% dilute sulfuric acid was added dropwise to adjust the pH to 4-5. After stirring for 0.5 hour, the pigment composition (1) was obtained by filtration, washing with water, drying and pulverization.

(Example 7)
A pigment composition (2) was obtained in the same manner as in Example 6 except that the pigment dispersant (B) was used in place of the pigment dispersant (A).

(Example 8)
A pigment composition (3) was obtained in the same manner as in Example 6 except that the pigment dispersant (C) was used in place of the pigment dispersant (A).

Example 9
A pigment composition (4) was obtained in the same manner as in Example 6 except that the pigment dispersant (D) was used instead of the pigment dispersant (A).

(Example 10)
A pigment composition (5) was obtained in the same manner as in Example 6 except that the pigment dispersant (E) was used instead of the pigment dispersant (A).

  Table 1 shows combinations of pigments and pigment dispersants used in preparing the pigment compositions (1) to (5).

<Preparation of pigment dispersion (pigment colorant for color filter (CF))>
(Example 11)
An acrylic resin varnish having a mean molecular weight of 12,000 and a solid content of 40% obtained by copolymerizing methacrylic acid / benzyl acrylate / styrene / hydroxyl acrylate at a molar ratio of 25/50/15/10 is used. Then, a pigment dispersion was prepared according to the method shown below. 50 parts of the acrylic resin varnish, 20 parts of the pigment composition (1), 17.4 parts of a basic polymer dispersant (trade name “DISPERBYK-2001”, manufactured by Big Chemie, solid content 46%), and a solvent 20 parts of propylene glycol-1-monomethyl ether-2-acetate was mixed, premixed, and then dispersed using a horizontal bead mill to obtain a CF pigment colorant (Example 11).

(Examples 12 to 15)
CF pigment colorants (Examples 12 to 15) were obtained in the same manner as in Example 11 except that the pigment compositions (2) to (5) were used in place of the pigment composition (1). It was.

(Comparative Example 1)
A composition containing PY138 that was not treated with the pigment dispersant was obtained in the same manner as in Example 6 except that the pigment dispersant (A) was not used. And it replaced with the pigment composition (1) and obtained the pigment colorant for CF (comparative example 1) like the above-mentioned Example 11 except having used the composition obtained above.

(Comparative Example 2)
Instead of the pigment dispersant (A), the same procedure as in Example 6 was used except that the pigment dispersant described in Patent Document 4 (sulfonated product of PY138 (pigment dispersant (L))) was used. A pigment composition (7) was obtained. A CF pigment colorant (Comparative Example 2) was obtained in the same manner as in Example 11 except that the pigment composition (7) obtained above was used instead of the pigment composition (1). It was.

(Comparative Example 3)
In place of the pigment dispersant (A), the triazine pigment dispersant (F) represented by the following formula (F) (described in Japanese Patent No. 5035718) was used, except that Example 6 described above was used. Similarly, a pigment composition (8) was obtained. A CF pigment colorant (Comparative Example 3) was obtained in the same manner as in Example 11 except that the pigment composition (8) obtained above was used instead of the pigment composition (1). It was.

<Evaluation>
For each of the pigment colorants for CF of Examples 11 to 15 and Comparative Examples 1 to 3, (1) fluidity (storage stability), (2) gloss of the color development surface, (3) foreign matter in the coating film, 4) Contrast and (5) Luminance (Y value) were evaluated. Each evaluation method is shown below. The evaluation results are shown in Tables 2 and 3.

(1) Fluidity (storage stability)
Using an E-type viscometer, the viscosity (mPa · s) of the CF pigment colorant immediately after preparation (initial stage) and after standing for 1 month at 25 ° C. (after standing) is measured to evaluate fluidity. Standard. The measurement conditions were temperature: room temperature (25 ° C.) and rotor rotation speed: 6 rpm. Further, “viscosity after standing / initial viscosity (%)” was calculated, and “storage stability” was evaluated according to the following criteria using the obtained calculated value.
○: “Viscosity after standing / initial viscosity” is 110% or less ×: “Viscosity after standing / initial viscosity” exceeds 110%

(2) Using a gloss bar coater (winding thickness: 0.45 mm) on the color development surface, the color pigment for CF was developed on a polypropylene film to form a color development surface. The gloss of the developed color surface was observed using a visual observation and a gloss meter, and “gloss of the color developed surface” was evaluated according to the following criteria. It can be determined that the higher the gloss of the color development surface, the better.
◎: Very good ○: Good ×: Bad

(3) Foreign matter in coating film A CF pigment colorant was applied to a glass substrate using a spinner, dried at 90 ° C for 2 minutes, and then heated at 270 ° C for 30 minutes to form a coating film. Using a microscope, the surface (application surface) of the formed coating film was observed at 200 times to confirm the presence or absence of foreign matter, and “foreign matter in the coating film” was evaluated according to the following criteria.
◎: No foreign matter ○: Slight foreign matter ×: Foreign matter

(4) Contrast A CF pigment colorant was applied to a glass substrate using a spinner, dried at 90 ° C. for 2 minutes, and then heated at 230 ° C. for 30 minutes to form a coating film. Further, three coating films were formed by changing the spinner speed. The brightness (brightness / dark brightness) of the coating film formed using a contrast meter (manufactured by Eye System) was measured, and the contrast (bright brightness / dark brightness) was calculated. Furthermore, the coating film was measured using a spectrophotometer (trade name “U-2000A”, manufactured by Hitachi, Ltd.), and chromaticity x or y was measured. An approximate straight line was drawn on a graph created by plotting contrast against chromaticity x or y, and the contrast at chromaticity x = 0.426 was read. Then, the contrast ratio (%) of each Example and Comparative Example was calculated with the contrast of Comparative Example 2 set to “100%”, and “Contrast” was evaluated according to the following criteria.
◎: 110% or more ○: 90% or more and less than 110% ×: less than 90%

(5) Luminance (Y value)
A CF pigment colorant was applied to a glass substrate using a spinner and dried at 90 ° C. for 2 minutes to form a coating film. Further, three coating films were formed by changing the spinner speed. The coating film was measured using a spectrophotometer, and chromaticity x or y was measured. An approximate straight line was drawn on a graph created by plotting luminance (Y value) against chromaticity x or y, and the Y value of chromaticity x = 0.426 was read. Moreover, about the thing which heated each said coating film at 230 degreeC for 30 minute (s), the color was measured similarly and the Y value was read. The difference (ΔY) between the Y value of the coating film treated at 230 ° C. and the Y value of the coating film treated at 90 ° C. was calculated, and “luminance” was evaluated according to the following criteria.
○: ΔY ≧ −0.1
×: ΔY <−0.1

  As shown in Tables 2 and 3, the CF pigment colorant of the example has a lower viscosity, better storage stability, and gloss on the color development surface than the CF pigment colorant of the comparative example. It can be seen that the film is good, no foreign matter is generated in the coating film, the contrast is high, and the luminance at 230 ° C. is hardly lowered as compared with the luminance at 90 ° C. From the above, it is clear that the pigment dispersants of the examples have excellent effects.

  Furthermore, the pigment compositions of the examples were used in printing inks such as offset inks; various paints such as nitrocellulose lacquer and melamine alkyd paint; and colorants of synthetic resins such as vinyl chloride resins. As a result, in any case, the pigment did not aggregate and showed good dispersibility. In addition, the pigment dispersants of the examples were used for the preparation of electrophotographic dry or wet toners, ink jet recording inks, thermal transfer recording inks, writing instrument inks, and the like that have recently been particularly required to have high dispersibility. . As a result, excellent dispersibility was exhibited in all cases.

  The pigment dispersant of the present invention includes printing ink (offset ink, gravure ink, etc.), various paints, plastics, pigment printing agents, electrophotographic dry or wet toner, ink jet recording ink, thermal transfer recording ink, color filter resist. It is useful as a dispersant to be blended in ink for writing instruments and the like, and its use is expected.

Claims (6)

A pigment dispersant which is a compound represented by the following general formula (1), a quaternary ammonium salt thereof, an amine salt thereof, or a metal salt thereof.

(In the general formula (1), A represents a hydrogen atom, a methyl group, or a t-butyl group, B represents a hydrogen atom or a methyl group, and C represents a chlorine atom, a hydroxyl group, or a 5-aminobenzimidazolone group. R represents a single bond or a linear alkylene group having 1 to 4 carbon atoms, and X represents a linking group represented by any one of the following general formulas (2-1) to (2-4). )

(In the general formulas (2-1) to (2-4), each Z independently represents a lower alkyl group, and each p independently represents an integer of 0 to 4. The general formula (2-2 ) in ~ (2-4), Y is, -CH ₂ each independently _{-, - C (CH 3)} 2 -, - shows a) - O-, or -SO ₂   A pigment composition comprising the pigment dispersant according to claim 1 and a pigment.   The pigment composition according to claim 2, wherein a blending amount of the pigment dispersant is 0.5 to 40 parts by mass with respect to 100 parts by mass of the pigment.   A pigment colorant comprising the pigment composition according to claim 2 and a film-forming material.   The pigment colorant according to claim 4, which is used for image display, image recording, printing ink, writing ink, plastic, pigment printing, or paint.   The pigment colorant according to claim 4, which is used for a color filter.