JP5547049B2 - Pigment dispersant, pigment composition, pigment colorant and color filter colorant - Google Patents

Description

  The present invention relates to a pigment dispersant, a pigment composition, and a pigment colorant. Examples of the use of the pigment colorant include image display, image recording, printing ink, writing ink, plastic, pigment textile printing, paint, and the like. The present invention relates to a technique useful for a photographic developer.

  Generally, when a pigment is mixed and dispersed in a vehicle such as paint, gravure ink, offset ink, it is difficult to stably disperse the pigment in the vehicle, and fine pigment particles once dispersed in the vehicle are There is a tendency to aggregate in the vehicle. When the pigment particles are aggregated in the vehicle, 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. Various problems such as lowering will occur.

  On the other hand, color filters used for manufacturing liquid crystal color displays, image sensors, etc. in vehicles are mainly produced by the following method using a pigment dispersion. First, a pigment dispersion for a color filter in which three pigments of red (R), green (G), and blue (B) are dispersed in a photosensitive resin liquid is prepared, and this is used as a color filter substrate. It is applied by spin coating to form a colored film. Next, a method is employed in which the formed colored film is exposed and developed through a photomask to pattern the colored film to form desired pixels on the color filter substrate.

  Green pigments, red pigments, and blue pigments as described below are used as the main pigments used in the production of the color filter. Examples of the green pigment include phthalocyanine green such as C.I. I. Pigment Green (hereinafter referred to as PG) 36, PG7, PG58, etc .: Examples of red pigments include diketopyrrolopyrrole red, such as C.I. I. Pigment Red (hereinafter referred to as PR) 254, anthraquinone red, for example PR177, azo red, for example PR242, etc .: As a blue pigment, phthalocyanine blue, for example C.I. I. Pigment Blue (hereinafter referred to as PB) 15: 6 is common. However, since there is a difference between the hue of these pigments and, for example, the color characteristics required for liquid crystal displays, the following pigments are used for complementary colors. Specifically, yellow pigments such as C.I. I. Pigment Yellow (hereinafter referred to as PY) 138, PY139, PY150 and the like are used in small amounts as complementary colors, and purple pigments such as C.I. I. A small amount of pigment violet (hereinafter referred to as PV) 23 is used as a complementary color.

  When the above-mentioned pigment is dispersed in a dispersion medium such as a photoresist, it is difficult to sufficiently disperse the above-mentioned pigment only by dispersing with a normal disperser, so that the coating solution may be poorly dispersed. When pixels of each color of the color filter are formed with such a coating liquid, the pixels lack light transmittance, and the light transmittance is insufficient as the pixels of the color filter. Therefore, a coating solution composed of a pigment that has only been dispersed by a normal disperser is unsatisfactory as a coating solution for forming a pixel of a color filter.

  On the other hand, as a resin generally used for a photoresist which is a pigment dispersion medium, an acrylic polymer having a high acid value is mainly used so that a colored coating film after exposure can be developed with an alkaline aqueous solution. It has been adopted. However, in the coating liquid composed of the above-described pigment and the above-described photoresist containing the high acid value acrylic resin, the aggregation of the pigment occurs and the viscosity of the coating liquid tends to increase. There is also a problem that pigment aggregation occurs over time, the coating solution thickens, and the storage stability of the coating solution often deteriorates.

  When the pixels of each color of the color filter are produced using the coating solution having the difficulty of dispersion as described above and problems associated therewith, there are the following problems. When manufacturing a color filter, as described above, a coating solution to be used is applied to a substrate by a spin coating method, and then a coating film is patterned by exposure and development. In this case, if the viscosity of the coating solution used is high, or if the pigment aggregates and exhibits a thixotropic viscosity, the central portion of the colored coating film (before exposure) made of the coating solution rises, so the large screen When producing a color filter, there arises a problem that unevenness and density difference occur in the hue between the central pixel and the peripheral pixel of the substrate.

  Therefore, the coating solution for color filters usually has a pigment concentration in a high concentration range of 5 to 20% by mass, but the dispersion state is such that pigment particles do not aggregate and a general normal dry paint. It is required that the viscosity should be low (for example, about 5 to 20 mPa · s) as compared with the baked paint, and further excellent in storage stability.

  In order to satisfy the above requirements, conventionally, a method of adding a pigment derivative of a pigment to be used as a dispersant, a method of using the pigment to be used by treating the pigment with the pigment derivative, and the like have been proposed. Specifically, when the pigment is diketopyrrolopyrrole red, for example, PR254, a substituted derivative of diketopyrrolopyrrole is used, and when the pigment is an anthraquinone red, for example, PR177, anthraquinone. When the pigment is an azo red, for example, PR242, an azo substituted derivative is used (see, for example, Patent Documents 1 to 3).

JP 2009-29886 A JP 2001-174616 A JP 2006-321979 A

  On the other hand, in recent years, due to the demand for further improvement of the performance of color filters, it has become necessary to improve the transparency of colored pixels, increase the contrast of transmitted light of colored pixels, and increase the pigment concentration of colored pixels. However, the conventional method using a pigment derivative as a dispersing agent for dispersing the pigment described above improves the transparency of the colored pixels by improving the dispersibility of the pigment until the high required performance in recent years can be satisfied, and the pigment concentration. It is difficult to prevent an increase in viscosity and a decrease in storage stability due to an increase in the viscosity. Moreover, in the above-described prior art, foreign matters may be generated in the coating film when the color filter is produced, and these improvements are desired.

  Therefore, the object of the present invention is to solve the above-mentioned problems in the prior art such as using a pigment derivative of a pigment to be used as a dispersant, or treating a pigment to be used with the pigment derivative, and printing ink (offset ink, Gravure ink, etc.), various paints, pigment printing agents, electrophotographic dry toners or wet toners, ink jet recording inks, thermal transfer recording inks, writing instrument inks, etc. In particular, it is an object of the present invention to provide a pigment dispersant, a pigment composition, and a pigment colorant that are useful in preparing a coating solution for a color filter having a high pigment concentration. More specifically, the object of the present invention is, of course, in various applications as described above, and in particular, can achieve a reduction in viscosity of a coating solution for color filters, and can increase the viscosity or gelation of the coating solution during storage. Another object of the present invention is to provide a color filter colorant that prevents the occurrence of foreign matters in the coating film during the production of the color filter and improves the transparency of the most important colored pixels as the color filter.

The above object is achieved by the present invention described below. That is, the present invention provides a pigment dispersant characterized by being a compound represented by the following general formula (1).

  The present invention also provides a pigment composition comprising a pigment and the pigment dispersant. In the pigment composition, the blending ratio of the pigment dispersant is preferably 0.05 to 40 parts by mass with respect to 100 parts of the pigment.

  The present invention also provides a pigment colorant comprising the pigment composition and a film-forming material. The pigment colorant is useful for image display, image recording, printing ink, writing ink, plastic, pigment printing or paint. Furthermore, the colorant for image display is particularly useful as a color filter colorant.

  According to the present invention, 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, For all pigments, including organic pigments and inorganic pigments, used for all vehicles used in various applications such as ink for writing instruments, the fluidity of inks and paints in each of the above applications is significantly improved. In addition, it is possible to provide a pigment dispersant capable of preventing aggregation of pigment particles and preventing generation of foreign matters. That is, a pigment dispersant that can be applied regardless of the structure of the pigment to be used, compared to the conventional method in which the pigment derivative of the pigment to be used is used as a dispersant or the pigment to be used is treated with the pigment derivative. Can be provided. Moreover, according to the pigment colorant produced using the pigment dispersant provided in the present invention, it is possible to provide a colored article exhibiting excellent gloss and sharpness. In particular, according to the present invention, it is possible to reduce the viscosity of a coating solution for a color filter having a high pigment concentration, to prevent the coating solution from thickening or gelling during storage, and to apply a coating solution at the time of producing a color filter. It is possible to provide a color filter colorant that prevents the generation of foreign matter in the film and improves the transparency of the most important color pixel as a color filter.

Next, the present invention will be described in more detail with reference to preferred embodiments.
As a result of intensive studies to solve the above-described problems of the prior art, the present inventors have reached the present invention. In particular, we developed a pigment dispersant that solves the problems of the prior art that occur when preparing color filter colorants (coating liquids) with high pigment concentrations, and that improves the color quality and lowers the viscosity of color filter coating liquids. As a result of intensive research, the present inventors have found the following. That is, the condensed azo compound having a specific structure defined in the present invention acts as an excellent pigment dispersant in a smaller amount, can achieve a low viscosity of the color filter coating solution, and can be used when stored. The present invention has been completed by preventing thickening and gelation of the coating solution, preventing the generation of foreign matter in the coating film during color filter production, and improving the transparency of the most important colored pixels as a color filter. It came to do.

  More specifically, the condensed azo compound having a specific structure represented by the general formula (1) is an azo compound when used in a pigment dispersant, regardless of the type (structure) of the pigment, Even when the addition amount is increased, the influence on the dispersion or the hue of the coating film is small, and the color filter coating liquid can achieve a lower viscosity than the conventional one. In addition to this, by using the pigment dispersant, it is possible to prevent thickening and gelation of the coating liquid during storage, and to prevent generation of foreign matter in the coating film during color filter production, and as a color filter It has been found that the transparency of colored pixels, which is one of the most important characteristics, can also be improved.

  The pigment composition of the present invention in which various organic pigments are dispersed using such a pigment dispersant is not only an image display colorant such as the color filter coating liquid described above, but also an image recording colorant, a paint, It can be stably dispersed at a high concentration and a low viscosity in a dispersion medium such as printing ink.

  Further, the pigment composition is particularly useful when used as a dispersant for a plurality of ultrafine pigment mixtures having different chemical structures and physical properties. The dispersion obtained in this case has a low viscosity, for example, a long-term It becomes an excellent colorant for a color filter coating solution that requires storage stability. For example, when the pigment dispersant of the present invention is used for dispersing a mixed pigment of PR254, PR242, and PR177, which are red pigments, there is an effect of giving excellent dispersion stability to each pigment. The following effects can be obtained. In other words, a red pixel that has excellent spectral transmittance characteristics, is crisp, has high transparency, and has excellent fastnesses such as light resistance, heat resistance, solvent resistance, chemical resistance, and water resistance. Can be formed. Hereinafter, each of the pigment dispersant, the pigment composition, the pigment colorant, and the color filter colorant of the present invention will be described.

<Pigment dispersant>
The pigment dispersant of the present invention is characterized by being a condensed azo compound having a structure represented by the following general formula (1). The pigment dispersant of the present invention having such characteristics has excellent affinity for various pigments and can be used for a wide range of pigments regardless of whether they are organic pigments or inorganic pigments. Moreover, since the pigment dispersant of this invention has the outstanding pigment dispersion effect, it can be used for manufacture of the coloring agent used in various uses.

  The pigment dispersant that is a compound represented by the above general formula (1) that characterizes the present invention (hereinafter sometimes simply referred to as “pigment dispersant of general formula (1)” or “pigment dispersant of the present invention”) For example, it can be synthesized as follows. First, an acid chloride of 3-hydroxy-2-naphthoic acid and 1,4-phenylenediamine are reacted at 130 to 135 ° C. in an inert solvent such as nitrobenzene. Next, p-acetylaminosulfonyl chloride and an amine having a basic nitrogen atom are reacted in a solvent such as toluene at 75 to 80 ° C., and then hydrolyzed by adding 35% hydrochloric acid to obtain the obtained reaction. The product can be obtained by diazotization and coupling.

  The pigment dispersant represented by the general formula (1) may have an asymmetric structure. In that case, it is compoundable as follows, for example. First, an aromatic compound or heterocyclic compound having an amino group which may have a substituent is diazotized, and then an acid chloride product of a reaction product coupled with 3-hydroxy-2-naphthoic acid is obtained. N- (4-aminophenyl) -3-hydroxynaphthalene-2-carboxamide is reacted at 130 to 135 ° C. in an inert solvent such as nitrobenzene. Next, p-acetylaminosulfonyl chloride and an amine having a basic nitrogen atom are reacted in a solvent such as toluene at 75 to 80 ° C., hydrolyzed by adding 35% hydrochloric acid, and the resulting reaction product is diazotized. It can be obtained by coupling.

  Examples of the amine having a basic nitrogen atom that can be used in the above method include the following. For example, N, N-dimethylaminomethylamine, N, N-diethylaminomethylamine, N, N-dipropylaminomethylamine, N, N-dibutylaminomethylamine, N, N-dimethylaminoethylamine, N, N- Diethylaminoethylamine, N, N-dipropylaminoethylamine, N, N-dibutylaminoethylamine, N, N-dimethylaminopropylamine, N, N-diethylaminopropylamine, N, N-dipropylaminopropylamine, N, N -Dimethylaminobutylamine, N, N-diethylaminobutylamine, N, N-dipropylaminobutylamine, N, N-dibutylaminobutylamine, N, N-dimethylaminolaurylamine, N, N-diethylaminolaurylamine, N, N- Dibutylaminolauri Amine, N, N-dimethylaminostearylamine, N, N-diethylaminostearylamine, N, N-diethanolaminoethylamine, N, N-diethanolaminopropylamine, N-aminopropylmorpholine, N-aminopropyl-4- Pipecoline, N-aminopropylpiperidine, N, N-diethylaminoethoxypropylamine, N, N, N ″, N ″ -tetramethyldiethylenetriamine, N, N, N ″, N ″ -tetraethyldiethylenetriamine, N, N, N ″ , N ″ -tetra (n-propyl) diethylenetriamine, N, N, N ″, N ″ -tetra (i-propyl) diethylenetriamine, N, N, N ″, N ″ -tetra (n-butyl) diethylenetriamine, N, N, N ", N" -tetra (i-butyl) diethylenetri Min, N, N, N ″, N ″ -tetra (t-butyl) diethylenetriamine, 3,3′-iminobis (N, N-dimethylpropylamine), 3,3′-iminobis (N, N-diethylpropylamine) ), 3,3′-iminobis (N, N-di (n-propyl) propylamine), 3,3′-iminobis (N, N-di (n-butyl) propylamine), 3,3′-iminobis (N, N-di (i-butyl) propylamine), 3,3′-iminobis (N, N-di (t-butyl) propylamine), 3,3′-iminobis (N, N-dimethylpropylamine) ), 2,9-dimethyl-2,5,9-triazadecane, 2,10-dimethyl-2,10-triazadecane, 2,12-dimethyl-2,6,12-triazatridecane, 2,12-dimethyl -2,5 , 12-triazatridecane, 2,16-dimethyl-2,9,16-triazaheptadecane, 3-ethyl-10-methyl-3,6,10-triazaundecane, 5,13-di (n -Butyl) -5,9,13-triazaheptadecane, di- (2-picolyl) amine, di- (3-picolyl) amine and the like can be used. Among these, N, N-dimethylaminopropylamine, N, N-diethylaminopropylamine, N, N-dipropylaminopropylamine, 3,3′-iminobis (N, N-dimethylpropyl) are particularly preferable. Amine), 3,3′-iminobis (N, N-diethylpropylamine) and the like.

  Moreover, the following are mentioned as an aromatic compound or heterocyclic compound which has an amino group which may have a substituent used in the said method. For example, aniline, toluidine (o-, m- or p-), 2,4-xylidine, 3,4-xylidine, p-cresidine, anisidine (o-, m- or p-), aminophenol (o-, m- or p-), anthranilic acid, p-aminobenzoic acid, nitroaniline (o-, m- or p-), chloroaniline (o-, m- or p-), 2,5-dichloroaniline, 3 , 4-dichloroaniline, 3,5-dichloroaniline, 2,4,5-trichloroaniline, 2-chloro-4-nitroaniline, 5-chloro-2-nitroaniline, 2,6-dichloro-4-nitroaniline O-fluoroaniline, 2,4-difluoroaniline, m-trifluoromethylaniline, 2-chloro-5-trifluoromethylaniline, 2-aminothiophenol 2-amino-5-nitrobenzonitrile, 2-amino-3-bromo-5-nitrobenzonitrile, diphenylamine, 1-naphthylamine, 2-naphthylamine, 3-amino-9-ethylcarbazole, 2-aminothiazole, 2- Amino-5-nitrothiazole, 2-aminobenzothiazole, 2-amino-6-methoxybenzothiazole, 1-aminoanthraquinone, 2-aminoanthraquinone, o- (phenylsulfonyl) aniline, 2-ethylsulfonyl-5-trifluoro Methylaniline, 4-benzylsulfonyl-o-anisidine, o-anisidine-4-sulfone diethylamide, o-anisidine-4-sulfoneethyl, 6-benzamide-m-4-xylidine, 4,4-dichloro-2-amino Diphenyl ether, 4-be Zuamido 2,5-dimethoxyaniline, 9-amino acridine, can be used such as 6-aminoindazole. Among these, particularly preferred are 2,5-dichloroaniline and 2-chloro-5-trifluoromethylaniline.

<Pigment composition>
The pigment composition of the present invention is characterized by containing the pigment dispersant described above, and can be obtained by dispersing the pigment with the pigment dispersant.
In the pigment composition of the present invention, the pigment dispersant is preferably blended at a ratio of 0.05 to 40 parts by mass with respect to 100 parts by mass of the pigment. A more preferable blending ratio of the pigment dispersant is about 0.1 to 10 parts by mass. If the blending ratio of the pigment dispersant is too small, the effect of the intended dispersant may not be sufficiently obtained, which is not preferable. On the other hand, if the blending ratio of the pigment dispersant is too large, not only the effect of using the pigment dispersant can be obtained, but the economic efficiency is inferior. On the contrary, as a result, the paint or ink vehicle using the obtained pigment composition is not suitable. It is not preferable because various physical properties are deteriorated, and furthermore, the hue of the pigment to be dispersed may be greatly changed depending on the color of the pigment dispersant itself.

  As described above, as a pigment that can obtain a dispersion effect by using the pigment dispersant of the present invention, it can be used for a wide range of pigments. Specifically, for example, a soluble / insoluble azo pigment, Examples include molecular weight azo pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, diketopyrrolopyrrole pigments, quinophthalone pigments, methine / azomethine pigments, perylene pigments, perinone pigments, isoindolinone pigments, isoindoline pigments, and metal complex pigments. Among these, particularly when used for a pigment having a red hue, a remarkable effect is obtained, and a pigment selected from PR177, PR242, and PR254 is particularly preferable.

The method for dispersing the pigment using the pigment dispersant of the present invention is not particularly limited, and examples thereof include the following methods.
(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 and dispersed in the vehicle.
(2) When dispersing the pigment in the vehicle or the like, the pigment and the pigment dispersant are separately added to the vehicle or the like at a predetermined ratio and 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 and dispersed at a predetermined ratio.
(4) A pigment dispersant is added to a dispersion obtained by dispersing the pigment in a vehicle or the like at a predetermined ratio to disperse the pigment.
Any of these methods can achieve the desired pigment dispersion effect.

  The pigment composition containing the pigment dispersant of the present invention can be produced by mixing the pigment and the pigment dispersant by a conventionally known method, and the production method is not particularly limited. For example, pigment powder and pigment dispersant powder are mixed without using a disperser: The pigment and the pigment dispersant are mechanically mixed with various dispersers such as a kneader, a roll, an attritor, and a horizontal bead mill. Method of adding: Mixing or mixing a solution in which the pigment dispersant of the present invention is dissolved or finely dispersed in a pigment suspension such as water-based or organic solvent-based, and uniformly depositing the pigment dispersant on the pigment surface: sulfuric acid, etc. There is a method in which a pigment and a pigment dispersant are dissolved in a solvent having strong dissolving power and then co-precipitated with a poor solvent such as water. Thus, when preparing the pigment composition, the pigment dispersant may be used in any form of solution, slurry, paste, and powder, and any form can exert the effect of the present invention.

<Pigment colorant>
The pigment colorant of the present invention comprises the pigment composition obtained as described above and a film-forming material such as a resin. Hereafter, the manufacturing method and use of the pigment colorant of this invention are demonstrated. The pigment colorant of the present invention can be obtained, for example, by containing the above-described finely divided pigment composition of the present invention and a film-forming material such as a (co) polymer, oligomer and / or monomer. Such a pigment colorant of the present invention can be widely used as a colorant for image display, image recording, printing ink, writing ink, plastic, pigment printing, paint and the like. In particular, it can also be used as a color filter colorant as an image display material in which the transparency of colored pixels is a problem. Of course, it is also useful as a material for forming an image recording agent, for example, an inkjet ink or an electrodeposition recording liquid, an electrophotographic developer, and these are image recordings such as an ink jet recording method, an electrodeposition recording method, and an electrophotographic method, respectively. Used in the method, it enables the provision of high quality images.

Hereinafter, a color filter dispersion (pigment colorant) will be described as an example of a pigment colorant for image display.
When preparing a color filter dispersion (colorant), first, the pigment composition of the present invention is added to a solution such as an organic solvent containing an appropriate resin that can function as a film forming material, and premixed and dispersed. To process. Specific examples include the following methods. For example, the above pigment composition is uniformly mixed and ground by a dispersing machine such as a vertical medium disperser, a horizontal medium disperser, or a ball mill, and then in a liquid containing a polymer having a film forming performance (film forming property). After the pigment and the pigment dispersant of the present invention are dissolved in sulfuric acid or the like, the sulfuric acid solution is precipitated in water, and the pigment and the pigment dispersant are separated as a solid solution or a eutectoid. In the same manner as described above, the obtained pigment composition is added and mixed in a liquid containing a film-forming polymer, a cationic polymer dispersant, and the like, and then ground and dispersed by a horizontal wet medium disperser (bead mill) such as Dino Mill. And so on.

  As the liquid containing a film-forming material for making a pigment dispersion used in the above-described method, a film-forming polymer used in a conventionally known pigment dispersion for color filters can be used. As the liquid medium, an organic solvent, water, or a mixture of an organic solvent and water can be used. Moreover, conventionally well-known additives, for example, additives, such as a dispersion | distribution adjuvant, a smoothing agent, and an adhesive agent, can be added to a pigment dispersion as needed.

  In the pigment colorant containing the pigment composition and the film-forming material, the pigment composition is preferably used in an amount of 5 to 500 parts by mass with respect to 100 parts by mass of the film-forming material. Further, as the liquid containing the film forming material, a liquid containing a photosensitive film forming material or a liquid containing a non-photosensitive film forming material can be used. Examples of the liquid containing a 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. Liquids containing non-photosensitive film-forming materials include, for example, varnishes used for printing inks such as letterpress inks, lithographic inks, gravure inks, screen inks, varnishes used for room temperature drying and baking paints, and electrodeposition coatings And varnish used for thermal transfer ribbons.

  Specific examples of the photosensitive film forming material include a photosensitive cyclized rubber resin, a photosensitive phenol resin, a photosensitive polyacrylate resin, a photosensitive polyamide resin, and a photosensitive polyimide resin. And unsaturated polyester resins, polyester acrylate resins, polyepoxy acrylate resins, polyurethane acrylate resins, polyether acrylate resins, polyol acrylate resins, and the like. Furthermore, various monomers can be added to these as reactive diluents.

  Further, a photo-curable photosensitive pigment dispersion can be obtained by adding a photopolymerization initiator such as benzoin ether or benzophenone to a pigment dispersion containing a photosensitive resin and kneading by a conventionally known method. . Moreover, it can replace with said photoinitiator and can also use it as a thermosetting pigment dispersion liquid using a thermal polymerization initiator.

  On the other hand, specific examples of the non-photosensitive film-forming material include, for example, styrene- (meth) acrylic acid ester (co) polymers, soluble polyamide resins, soluble polyimide resins, soluble polyamideimide resins, Examples include soluble polyesterimide resins, water-soluble salts of styrene-maleic acid ester copolymers, water-soluble salts of (meth) acrylic acid ester- (meth) acrylic acid copolymers, and water-soluble aminopolyester resins. It is done.

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

[Preparation of pigment dispersant]
<Example 1>
A pigment dispersant (A) was synthesized. First, according to a conventional method, in 400 parts of nitrobenzene, 56.5 parts of 3-hydroxy-2-naphthoic acid was acid chlorided using 40 parts of thionyl chloride, and then 16.2 parts of 1,4-phenylenediamine, 2 parts of pyridine was added and heated at 130-135 ° C. for 5 hours. After cooling, 200 parts of methanol was added, filtered, washed with methanol and then with water, and then dried to obtain 64 parts of a reaction product. To the obtained reaction product, 2,400 parts of methanol and 46 parts of sodium hydroxide were added to prepare a submerged solution. Next, 70.1 parts of p-acetylaminosulfonyl chloride and 39.1 parts of N, N-diethylaminopropylamine were reacted at 75-80 ° C. for 2 hours in 250 parts of toluene by a conventional method. Thereafter, 125 parts of 35% hydrochloric acid was added to hydrolyze the reaction product, which was then diazotized, and then coupled to the above-obtained submerged solution. Thereafter, the mixture was filtered, washed with methanol and then with water and dried to obtain 134 parts of a pigment dispersant (A). Elemental analysis was performed on the obtained pigment dispersant (A), C, H, N, and S were measured, and the composition of each element constituting the pigment dispersant (A) was determined. From the raw materials used and the results of elemental analysis, it was estimated that the pigment dispersant (A) obtained above had the following structure. Table 1 shows the results of elemental analysis and the theoretical values for the following structure. As is clear from the description in Table 1, good agreement was shown.

<Example 2>
In the same manner as in Example 1 except that 26.6 parts of 2,5-dichloro-1,4-phenylenediamine was used instead of 16.2 parts of 1,4-phenylenediamine used in Example 1, 143 parts of pigment dispersant (B) were obtained. Then, the pigment dispersant (B) was identified in the same manner as the pigment dispersant (A). Table 2 shows the results of elemental analysis and the theoretical values for the following structure. The pigment dispersant (B) was estimated to have the following structure.

<Example 3>
In the same manner as in Example 1, except that 56.2 parts of bis [3- (dimethylamino) propyl] amine was used instead of 39.1 parts of N, N-diethylaminopropylamine used in Example 1, 156 parts of pigment dispersant (C) were obtained. Then, the pigment dispersant (C) was identified in the same manner as the pigment dispersant (A). Table 3 shows the results of elemental analysis and the theoretical values for the following structure. The pigment dispersant (C) was estimated to have the following structure.

<Example 4>
In place of 16.2 parts of 1,4-phenylenediamine used in Example 1, 26.6 parts of 2,5-dichloro-1,4-phenylenediamine were used, and N.N-diethylaminopropylamine 39. 158 parts of pigment dispersant (D) was obtained in the same manner as in Example 1 except that 56.2 parts of 3,3′-iminobis (N, N-dimethylpropylamine) was used instead of 1 part. . Then, the pigment dispersant (D) was identified in the same manner as the pigment dispersant (A). Table 3 shows the results of elemental analysis and the theoretical values for the following structure. The pigment dispersant (D) was estimated to have the following structure.

<Example 5>
The pigment dispersant (E) was synthesized as follows. First, 48.6 parts of 2,5-dichloroaniline was diazotized by a conventional method, coupled with 56.5 parts of 3-hydroxy-2-naphthoic acid, washed and dried. Then, after the obtained reaction product was acid chlorided in 2,000 parts of nitrobenzene using 40 parts of thionyl chloride, 83.5 parts of N- (4-aminophenyl) -3-hydroxynaphthalene-2-carboxamide, 4 parts of pyridine was added and heated at 130 to 135 ° C. for 5 hours. After cooling, 200 parts of methanol was added, filtered, washed with methanol and then with water, and dried to obtain 177 parts of a reaction product. To the obtained reaction product, 2,400 parts of methanol and 46 parts of sodium hydroxide were added to prepare a submerged solution. Next, 70.1 parts of p-acetylaminosulfonyl chloride and 39.1 parts of N, N-diethylaminopropylamine were reacted in 250 parts of toluene at 75-80 ° C. for 2 hours by a conventional method, and 35% hydrochloric acid 125 The reaction product hydrolyzed by adding a portion was diazotized and coupled to the above-mentioned submerged liquid. Thereafter, the mixture was filtered, washed with methanol and then with water, and dried to obtain 235 parts of a pigment dispersant (E). Elemental analysis was performed on the obtained pigment dispersant (E), C, H, N, S and Cl were measured, and the composition of each element constituting the pigment dispersant (E) was determined. From the raw materials used and the results of elemental analysis, it was estimated that the pigment dispersant (E) obtained above had the following structure. The results of elemental analysis and the theoretical values for the following structure are shown in Table 5. As is clear from the description in Table 5, good agreement was shown.

<Example 6>
Example 5 and Example 5 were used except that 56.2 parts of 3,3′-iminobis (N, N-dimethylpropylamine) was used instead of 39.1 parts of N, N-diethylaminopropylamine used in Example 5. Similarly, 250 parts of a pigment dispersant (F) was obtained. Then, the pigment dispersant (F) was identified in the same manner as the pigment dispersant (E). Table 6 shows the results of elemental analysis and the theoretical values for the following structure. The pigment dispersant (F) was estimated to have the following structure.

<Example 7>
Pigment dispersion was carried out in the same manner as in Example 5 except that 58.7 parts of 2-chloro-5-trifluoromethylaniline was used instead of 48.6 parts of 2,5-dichloroaniline used in Example 5. 244 parts of agent (G) were obtained. Then, the pigment dispersant (G) was identified in the same manner as the pigment dispersant (E). Table 7 shows the results of elemental analysis and the theoretical values for the following structure. The pigment dispersant (G) was estimated to have the following structure.

<Example 8>
Instead of 48.6 parts of 2,5-dichloroaniline used in Example 5, 58.7 parts of 2-chloro-5-trifluoromethylaniline were used, and 39.1 parts of N, N-diethylaminopropylamine were used. In the same manner as in Example 5, except that 56.2 parts of 3,3′-iminobis (N, N-dimethylpropylamine) was used, 259 parts of a pigment dispersant (H) was obtained. Then, the pigment dispersant (H) was identified in the same manner as the pigment dispersant (E). Table 8 shows the results of elemental analysis and the theoretical values for the following structure. The pigment dispersant (H) was estimated to have the following structure.

[Preparation of pigment composition]
<Example 9> (Preparation of pigment composition (1))
First, a press cake of PR254 (solid content 26%) was weighed so that the pigment content would be 100 parts, and 2,000 parts of water was added to sufficiently reslurry. To the obtained slurry, 100 parts of a 5% diluted acetic acid solution of the pigment dispersant (A) prepared in Example 1 was added and stirred for 1 hour. Further, a 5% aqueous sodium carbonate solution was gradually added dropwise to the stirred product until the pH reached 9 to 10, and then filtered, sufficiently washed with water, and dried at 80 ° C. This gave 105 parts of PR254 pigment composition (1).

<Examples 10 to 16> (Preparation of pigment compositions (2) to (8))
The same operation as in Example 9 except that the pigment dispersants (B) to (H) obtained in Examples 2 to 8 were used in place of the pigment dispersant (A) used in Example 9. To obtain pigment compositions (2) to (8).

<Examples 17 to 24> (Preparation of pigment compositions (9) to (16))
A PR242 pigment composition (9) was obtained in the same manner as in Example 9 except that PR242 press cake (solid content 24%) was used instead of the PR254 press cake used as the pigment. Further, PR242 pigment compositions (10) to (16) were obtained in the same manner as above except that the pigment dispersants (B) to (H) obtained earlier were used respectively.

<Examples 25 to 32> (Preparation of pigment compositions (17) to (24))
A PR177 pigment composition (17) was obtained in the same manner as in Example 9 except that a PR177 press cake (solid content 23%) was used instead of the PR254 press cake used as the pigment. Further, PR177 pigment compositions (17) to (24) were obtained in the same manner as described above except that the previously obtained pigment dispersants (B) to (H) were used respectively.

Table 9 summarizes the combinations of pigments and pigment dispersants used in producing the above-described pigment compositions.

[Preparation of pigment dispersion (base color)]
<Example 33> (Example of pigment dispersion)
Using an acrylic resin varnish having a 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, A pigment dispersion was prepared by the method described above. 50 parts of the acrylic resin varnish obtained above, 20 parts of the pigment composition (1) of Example 9, 20 parts of propylene glycol-1-monomethyl ether-2-acetate (hereinafter abbreviated as PGMAc) as a solvent, After premixing, the mixture was dispersed with a horizontal bead mill to obtain a red pigment dispersion.

<Examples 34 to 56>
Instead of the pigment composition (1) used in Example 33, the pigment compositions (2) to (24) obtained above were used in the same manner as in Example 33, except that the pigment compositions (2) to (24) were used. 56 red pigment dispersions were obtained.

<Comparative Example 1>
The same procedure as in Example 33 was performed, except that 20 parts of PR254 not treated with a pigment dispersant was used instead of 20 parts of the pigment composition (1) used in Example 33. A color filter colorant containing PR254 that was not used was prepared.

<Comparative example 2>
The same procedure as in Example 33 was performed, except that 20 parts of PR242 not treated with a pigment dispersant was used instead of 20 parts of the pigment composition (1) used in Example 33. A color filter colorant containing PR242 that was not used was prepared.

<Comparative Example 3>
The same procedure as in Example 33 was performed, except that 20 parts of PR177 not treated with a pigment dispersant was used instead of 20 parts of the pigment composition (1) used in Example 33. A color filter colorant containing PR177 that was not used was prepared.

[Evaluation]
About the color filter colorants of Examples 33 to 56 and Comparative Examples 1 to 3 obtained above, the fluidity, the gloss of the color development surface, and the presence or absence of foreign matter in the coating film were compared. The fluidity of the colorant, the gloss of the color development surface, and the presence or absence of foreign matter in the coating film were measured according to the following method, and relative evaluation with the comparative example was performed. The results are summarized in Table 10.

(1) Flowability (viscosity change)
Each of the colorants in the examples and comparative examples were each immediately after production and after being left for one month at 25 ° C. under the measurement conditions of room temperature (25 ° C.) / Rotor rotation speed of 6 rpm using an E-type viscometer. The viscosity (mPa · s) of was measured. And the fluidity | liquidity of each coloring agent was evaluated using the obtained measured value.

(2) Gloss Each colorant of Examples and Comparative Examples was developed on a polypropylene film by using a bar coater (winding thickness: 0.45 mm), and the gloss of the obtained color development surface was obtained. Evaluation was made by comparison with visual observation and a gloss meter. In addition, the thing with high gloss was made favorable, and the result was each described by the parameter | index of (circle): favorable and x: defect.

(3) Observation of foreign matter Each of the colorants of Examples and Comparative Examples was applied to a glass substrate with a spinner, dried at 90 ° C. for 2 minutes, and further heated at 270 ° C. for 30 minutes. About the obtained coating surface, the presence or absence of the foreign material was observed and evaluated at 200 times using a microscope. In addition, it displayed with the parameter | index of (circle): No foreign material and x: Foreign material.

  As shown in Table 10, each color filter colorant using the pigment dispersant of the examples of the present invention has no foreign matter compared to the comparative example, and exhibits high flow characteristics. The gloss was also good, and the effect of the pigment dispersant of the present invention was recognized.

  Furthermore, the pigment composition obtained by adding the dispersant of the examples of the present invention, printing ink such as offset ink, various paints such as nitrocellulose lacquer and melamine alkyd paint, coloring of synthetic resin such as vinyl chloride resin, etc. In any case, the pigment did not aggregate and exhibited good dispersibility. In addition, the dispersant of the examples of the present invention was used in the production of dry toner or wet toner for electrophotography, ink for ink jet recording, ink for thermal transfer recording, ink for writing instruments, etc., for which high dispersibility is particularly required recently. However, even in these cases, 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 types of vehicles such as ink for writing instruments, a wide range of pigments including organic pigments and inorganic pigments, remarkably improve fluidity of inks and paints, prevent aggregation of pigment particles, Can be provided, and a colored article exhibiting excellent gloss and clearness can be provided, and its wide use is expected.

Claims (6)

A pigment dispersant, which is a compound represented by the following general formula (1).

  A pigment composition comprising a pigment and the pigment dispersant according to claim 1.   The pigment composition according to claim 2, wherein a blending ratio of the pigment dispersant is 0.05 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, wherein the use is for image display, image recording, printing ink, writing ink, plastic, pigment printing or paint.   The pigment colorant according to claim 5, wherein the use of the image display is for a color filter.