JP2007293061A - Red-colored composition, and red coating film and color filter using the composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a red-colored composition capable of controlling retardation, and to provide a coating film and a color filter that uses the composition. <P>SOLUTION: The red-colored composition contains a diketopyrrolopyrrole pigment, having an average primary particle diameter of ≤40 nm and a pigment carrier comprising resin, a precursor thereof or a mixture of those, wherein in the X-ray diffraction spectrum of the coating film formed from the composition, the ratio (I<SB>020</SB>/I<SB>111</SB>) of the peak intensity (I<SB>020</SB>) of the plane index (020) to the peak intensity (I<SB>111</SB>) of the plane index (111) is 7 or larger. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a red coloring composition, and a coating film and a color filter using the composition.

The red coloring composition is used as an optical member application such as an image material for a color filter of a liquid crystal display device, an optical coating material, and a light absorbing material.
In recent years, in order to improve the display characteristics of a liquid crystal display device or the like, it is necessary to reduce the retardation of a coating film using a red coloring composition. In addition, a high contrast ratio (about 5000 or more) is required for the red pixel of the liquid crystal display device.
For example, JP 2000-136253 A (Patent Document 1) and JP 2000-187114 A (Patent Document 2) disclose a relation between retardation and birefringence and a colored polymer thin film using retardation-reducing particles. ing.
However, these colored polymer films and color filters using the polymer films for pixels correspond to a relatively low contrast ratio (1000 or less for a red polymer thin film), and retardation at a high contrast ratio in recent years. It did not solve the problem.
Moreover, Patent Document 1 and Patent Document 2 did not suggest the relationship between the orientation of the fine red pigment and the retardation in the coating film.
JP 2000-136253 A JP 2000-187114 A

  An object of the present invention is to provide a red coloring composition capable of controlling retardation, and a coating film, a laminate and a color filter using the composition.

The inventors of the present invention can control the retardation of the red coating film by using a red coloring composition in which the X-ray diffraction spectrum relating to the orientation of the fine diketopyrrolopyrrole pigment becomes a specific value during film formation. I found it. The present invention is based on such knowledge.
The present invention relates to a red coloring composition comprising a diketopyrrolopyrrole pigment having an average primary particle size of 40 nm or less and a pigment carrier comprising a resin, a precursor thereof, or a mixture thereof, and a coating film when a film is formed In the X-ray diffraction spectrum, the peak of the plane index (020) is detected most strongly.

Next, the present invention is a red coloring composition comprising a diketopyrrolopyrrole pigment having an average primary particle size of 40 nm or less and a pigment carrier comprising a resin, a precursor thereof or a mixture thereof, and when the film is formed In the X-ray diffraction spectrum of the coating film, the ratio (I ₀₂₀ / I ₁₁₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₁₁₁ ) of the plane index ( ₁₁₁ ) is 7 or more The present invention relates to a red coloring composition.

Next, the present invention is a red coating film using a diketopyrrolopyrrole pigment having an average primary particle size of 40 nm or less and a pigment carrier comprising a resin, a precursor thereof or a mixture thereof, and an X-ray diffraction spectrum The ratio (I ₀₂₀ / I ₁₁₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₁₁₁ ) of the plane index ( ₁₁₁ ) at 7 is 7 or more, the film thickness is 4 μm or less, and It is related with the red coating film characterized by the retardation in 590 nm being -120-0.
In particular, the diketopyrrolopyrrole pigment is a solvent salt in which a mixture of a pigment (A) heat-treated with an aqueous emulsion of a crystallization solvent, a grinding aid (B), and a water-soluble organic solvent (C) is kneaded. It is preferable that it is refined | miniaturized by the milling method.
Next, this invention relates to the color filter formed using said red coating film.

  The red coloring composition of the present invention can control the retardation of the coating film when the red coloring composition is formed. The red coating film of the present invention contributes to greatly improving the viewing angle dependency. The color filter of the present invention is excellent in display characteristics at a high contrast ratio.

The red coloring composition of the present invention contains a diketopyrrolopyrrole pigment having an average primary particle size of 40 nm or less, a pigment, a resin, a precursor thereof, or a mixture thereof. Moreover, it is also preferable to contain a solvent and an initiator.
Red colored composition of the present invention provides an X-ray diffraction spectrum of the red pigment in the case of film formation, the peak intensity of the plane index (020) to the peak intensity _{(I -151)} plane index (-151) _{(I 020} ratio) _{(I 020 /} I _-151) is, for that is two or more and the first feature. Further, the ratio (I ₀₂₀ / I ₁₁₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₁₁₁ ) of the plane index ( ₁₁₁ ) is 7 or more. .

The diketopyrrolopyrrole pigment used in the red coloring composition of the present invention having an average primary particle size of 40 nm or less (hereinafter sometimes simply referred to as DPP) is obtained by adjusting the orientation and crystal structure of the pigment, Any diketopyrrolopyrrole pigment may be used as long as the red coloring composition has the characteristics of the X-ray diffraction spectrum.
For example, a solution obtained by dissolving a diketopyrrolopyrrole-based crude pigment in concentrated sulfuric acid is poured into water to cause precipitation (hereinafter referred to as acid pasting), and after heat treatment with an aqueous emulsion of a crystallization solvent, filtration is performed. A mixture containing pigment (A), water-soluble inorganic salt (B), and water-soluble organic solvent (C) that does not substantially dissolve the water-soluble inorganic salt is mechanically removed with a kneader or the like. After kneading (hereinafter referred to as salt milling or solvent salt milling), the mixture is put into water and stirred with a high speed mixer or the like to form a slurry, and then the slurry is filtered and washed with water to wash the water-soluble inorganic salt (B) and water. Produced by removing the organic solvent (C).

The diketopyrrolopyrrole crude pigment used in the present invention is represented by the generic name of the color index. I. PIGMENT RED254, or C.I. I. PIGMENT ORANGE 71 and the like.
Useful diketopyrrolopyrrole pigments have a color tone suitable not only for light resistance, heat resistance and transparency, but also for the required spectral spectrum. I. PIGMENT RED254 (3,6-bis-p-chlorophenyl-1,4-diketopyrrolopyrrole). C. I. As disclosed in Japanese Patent Application Laid-Open No. 08-48908, PIGMENT RED254 has two crystal types, a stable crystal type generally referred to as α-type and a β-type unstable crystal type. The β form is unstable and transitions to the α form by heat. The diketopyrrolopyrrole crude pigment may be either α or β or a mixture. However, in order to prevent hue change under heating conditions, it is preferable to use only the stable α-type.

In the present invention, as long as the average primary particle size of the diketopyrrolopyrrole pigment in the red coloring composition can be 40 nm or less, the method for adjusting the average primary particle size is not limited.
For example, as disclosed in Japanese Patent Application Laid-Open No. 07-90189, a method for directly obtaining a fine pigment during synthesis of a diketopyrrolopyrrole pigment, or disclosed in Japanese Patent Application Laid-Open No. 2000-7777. As described above, there is a method for suppressing the crystal growth of a diketopyrrolopyrrole pigment.
There is also a method of chemically or mechanically refining coarse diketopyrrolopyrrole pigments. As a chemical method, there is a method of dispersing together with a pigment dispersant or a surfactant, and as a mechanical method, there is a method of grinding with a roll or a bead mill. Of course, you may refine | miniaturize combining a chemical method and a mechanical method. This is because both contribute to the reduction of pigment aggregation.
For example, the above-mentioned acid pasting and solvent salt milling can be performed. Further, a dye derivative may be used in combination with a diketopyrrolopyrrole crude pigment during acid pasting or salt milling. A dye derivative is a compound in which a substituent is introduced into a prototype residue of an organic dye as represented by a generic name of a color index, and functions to suppress crystal growth of a DPP pigment during salt milling. . Examples of the structure of the organic dye serving as a base of the dye derivative include DPP, quinacridone, anthraquinone, perylene, perinone, isoindoline, quinophthalone, and metal complex. The organic dye may be a light yellow aromatic polycyclic compound such as naphthalene or anthraquinone which is not generally called a dye.

Examples of the substituent introduced into the organic dye include a hydroxyl group, a carboxyl group, a sulfonic acid group, a carbamoyl group, a sulfonamide group, or a basic substituent represented by the following general formula (1).
Formula (1): —X— (CH ₂ ) _n —NR ₁ R ₂
X: a direct _{bond, -CH 2 NHCOCH 2 -, -} SO 2 NH -, - CONHOCH 2 NH-, or - represents a (CH _{2) q} NH-.
R ₁ and R ₂ each independently represents a saturated or unsaturated alkyl group that may be substituted, or substituted or unsubstituted containing a nitrogen, oxygen, or sulfur atom formed integrally by R ₁ and R ₂ Represents a heterocycle of

The amount of the dye derivative used during acid pasting or solvent salt milling is not particularly limited, but is preferably 0.5 to 20% by weight, particularly 2 to 15% by weight, based on the DPP pigment. In addition, since the pigment derivative also has an effect as a dispersant, it is preferable to select one having good dispersibility in the transparent resin varnish. Moreover, you may combine the pigment derivative with a high crystal growth prevention effect, and dispersing agents other than other pigment derivatives or pigment derivatives.
Dispersants other than pigment derivatives include condensates of ricinoleic acid and 12-hydroxystearic acid, basic polymer compounds, copolymers containing acid groups, fatty acid esters, aliphatic polyamine / polyester graft polymers, polyethylene / So-called resin-type dispersants such as polypropylene addition polymers can be used. These dispersants are used at the time of salt milling treatment or at the time of dispersing the salt milling treatment pigment in the transparent resin varnish.

  The concentration of concentrated sulfuric acid used for acid pasting is not particularly limited, but it is preferable to use 95-98% sulfuric acid. The amount of concentrated sulfuric acid used with respect to the pigment is not particularly limited, but if it is small, the solution viscosity is high and handling becomes difficult. On the other hand, it is preferable to use 3 to 10 times by weight of concentrated sulfuric acid. The pigment need not be completely dissolved.

  The amount of water for injecting the sulfuric acid solution of the pigment is preferably 10 to 100 times the weight of the pigment. Further, at the time of injection, it is preferable to use ice water in order to suppress heat generation, and the sulfuric acid solution temperature of the pigment is 50 ° C. or lower, preferably 30 ° C. or lower, with strong stirring so as not to become non-uniform.

  As an aqueous emulsion of a crystallization solvent used in solvent salt milling, aromatic solvents such as chlorobenzene, nitrobenzene, toluene, orthochlorotoluene and xylene, alcohols such as butanol, isobutanol and pentanol can be used as the crystallization solvent. The activator may be any of a nonionic activator, a cationic activator, and an anionic activator, but is preferably a nonionic activator. An emulsion is obtained by vigorously stirring water, a crystallization solvent and an activator with a high speed mixer or the like. The composition of the emulsion is 5 to 30% by weight of crystallization solvent, 0.5 to 5% by weight of activator, 10 to 50% by weight of water, preferably 10 to 20% by weight of crystallization solvent, based on the pigment to be treated. 1 to 3% by weight of the agent and 10 to 50% by weight of water.

  The water-based emulsion may be added before the sulfuric acid solution of the pigment is added to the water or after the sulfuric acid solution is added to the water, but before the sulfuric acid solution is added to the water, that is, the sulfuric acid solution of the pigment is added. A formulation that is added to water in the presence of an aqueous emulsion is preferred. The pigment slurry containing the water-based emulsion is heat-treated at 60 to 100 ° C., preferably at 80 ° C. for 0.5 to 3 hours, separated by filtration, washed with water, dried and pulverized, and the water-based emulsion of the crystallization solvent. Let it be the heat-treated pigment (A).

The water-soluble inorganic salt (B) used for salt milling is not particularly limited as long as it functions as a grinding aid and dissolves in water. Sodium chloride (salt), barium chloride, potassium chloride, sodium sulfate However, it is preferable to use sodium chloride (salt) from the viewpoint of price.
The amount of the inorganic salt (B) used in the salt milling is preferably 1 to 20 times by weight, particularly 3 to 15 times by weight, that of the DPP pigment, from the viewpoint of both processing efficiency and production efficiency. This is because the finer efficiency is higher as the amount ratio of the inorganic salt to the DPP pigment is larger, but the processing amount of one pigment is reduced.

The water-soluble organic solvent (C) used for salt milling functions to wet the DPP crude pigment (A) and the water-soluble inorganic salt (B), and is dissolved (mixed) in water and used. If (B) is not melt | dissolved substantially, it will not specifically limit. However, a high boiling point solvent having a boiling point of 120 ° C. or higher is preferable from the viewpoint of safety because the temperature rises during salt milling and the solvent is easily evaporated.
Examples of the water-soluble organic solvent (C) include 2-methoxyethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, Triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, liquid Polypropylene glycol or the like is used.

  At the time of salt milling, a resin can be used in combination, and a powder pigment that can be easily dispersed can be obtained. The resin used for salt milling is preferably a resin that is solid at room temperature, insoluble in water, and at least partially soluble in the organic solvent, and is modified with a natural resin, a modified natural resin, a synthetic resin, or a natural resin. A synthetic resin or the like is used. As the natural resin, rosin is typical, and as the modified natural resin, rosin derivatives, fiber derivatives, rubber derivatives, protein derivatives and oligomers thereof are used. Examples of the synthetic resin include epoxy resin, acrylic resin, maleic acid resin, butyral resin, polyester resin, melamine resin, phenol resin, polyurethane resin, and polyamide resin. Examples of synthetic resins modified with natural resins include rosin-modified maleic acid resins and rosin-modified phenolic resins. The amount of the resin used is preferably in the range of 5 to 100% by weight with respect to the DPP pigment.

The average primary particle diameter of the diketopyrrolopyrrole pigment refers to the diameter of the pigment particles in the smallest unit. For example, the average primary particle size is prepared with a red colored composition, diluted with the solvent most contained in the red colored composition, sampled on a mesh with a collodion support film, and sampled with a transmission electron microscope. It can be obtained by calculating an average value obtained by analyzing the observed image.
When the average primary particle size is large, light scattering becomes strong and it is difficult to obtain a high contrast. Therefore, the average primary particle size is preferably 40 nm or less.

  The pigment carrier contained in the red resin composition of the present invention comprises a known resin, a precursor thereof (monomer, dimer, trimer, oligomer, etc.), or a mixture thereof, and is effective for pigment dispersibility and dispersion stability. Just select a certain one. For example, vinyl resin or phosphoric acid resin. The ratio of the pigment and the resin is preferably a weight ratio of pigment weight: resin weight = 8: 2 to 9: 1.

  In the red resin composition of the present invention, if necessary, pigments other than red, solvent dyes, antioxidants, polymerization inhibitors, leveling agents, moisturizers, viscosity modifiers, antiseptics, antibacterial agents, surfactants, Various additives such as an anti-blocking agent, an ultraviolet absorber, an infrared absorber, a filler, and a conductive material can be added.

A method of applying the red coloring composition of the present invention to a substrate by spin coating, bar coater, blade coater, roll coater, die coater, screen printing method, etc., a method of immersing the substrate in the coloring paste, a coloring paste on the substrate Regardless of the coating method such as spraying, after coating, the film can be formed by air drying, reflux drying, vacuum drying or the like. In addition, it is preferable to perform post-baking at the time of film forming. This is because the post-baking can maintain the correlation between the later-described X-ray diffraction spectrum and retardation.
In the coating film thus formed, in the X-ray diffraction spectrum, the ratio (I ₀₂₀ / I) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₋₁₅₁ ) of the plane index ( ₋₁₅₁ ). ₋₁₅₁ ) is 2 or more, and the ratio (I ₀₂₀ / I ₁₁₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₁₁₁ ) of the plane index ( ₁₁₁ ) is 7 or more. Become.
Of course, a red coating film using a red coloring composition is also one embodiment of the present invention. Red coating of the present invention, the peak intensity _{(I 020)} of plane indices (020) to the peak intensity _{(I 111)} of plane indices of the X-ray diffraction spectrum (111) of the ratio _(I 020 _{/ I 111)} is 7 or more The film thickness is 4 μm or less, and the retardation at 590 nm is −120 to 0. The film thickness can be adjusted by the above coating method.

X-ray diffraction spectrum is a material structure research method using X-ray diffraction images of powder samples and polycrystalline samples, and samples are identified and analyzed using the intensity of each diffraction line and the surface spacing determined from the scattering angle. Used for purposes. The X-ray diffraction spectrum can measure not only powder but also a coating film.
The measurement conditions in the present invention are as follows.
X-ray diffraction measurement device: “X'PertPRO” manufactured by Philips
X-ray generator: Cu (encapsulated tube)
Filter: None Sampling width: 0.0167 °
Scan speed: 0.108 ° / s
Tube voltage: 45kV
Divergent slit: 0.5 °
Tube current: 40 mA
Scan axis: 2θ / θ
Scattering slit: 0.5 °
Measurement angle range: 3-50 °

For example, the powder X-ray diffraction result of a general diketopyrrolopyrrole pigment (“Irgafoa Red B-CF” manufactured by Ciba Specialty Chemicals) is as shown in FIG.
Further, in the non-patent document “Acta Cryst. (1993). B49, 1056-1060”, the rotation angle of the aromatic group of the diketopyrrolopyrrole pigment gives the strength in the hydrogen bond direction and the lamination direction of X-ray diffraction. The impact is described.
Considering the influence of FIG. 1 and the rotation angle of the aromatic group, FIG. 2 shows the X-ray diffraction result when the red coloring composition of the present invention is used as a coating film. When the dimensions of FIG. 2 are matched based on FIG. 1, the peak intensity of the plane index (111) in FIG. 2 is around 24.7 °, the intensity of the plane index (020) is around 7.5 °, and the plane index The peak intensity of (−151) is located around 25.4 °. In FIG. 2, the ratio (I ₀₂₀ / I ₋₁₅₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₋₁₅₁ ) of the plane index ( ₋₁₅₁ ) is 2 or more.

Furthermore, the relationship between the ratio (I ₀₂₀ / I ₁₁₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₁₁₁ ) of the plane index ( ₁₁₁ ) and the retardation is shown in FIG.
In addition, the optical characteristic value in this invention is defined as follows.
nxy: Refractive index when light vibration direction is parallel to the film surface of the thin film nz: Refractive index when light vibration direction is perpendicular to the film surface of the thin film d: Average film thickness refractive index n (avg) = (2nxy + nz) / 3
Birefringence Δn = nxy-nz
Retardation: product of birefringence and film thickness (Δn × d)

From FIG. 3, the ratio (I ₀₂₀ / I ₁₁₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₁₁₁ ) of the plane index ( ₁₁₁ ) is correlated with the retardation of the red coating film.
If this correlation is utilized, the red coloring composition and red coating film using the fine diketopyrrolopyrrole pigment used as a desired retardation can be provided. In particular, considering the optical characteristics of red and green pixels in recent color filters, the 590 nm retardation (Red) at a film thickness of 4 μm or less is −120 to 0 in the red coating film of the present invention. This is because the green pixel has the highest luminous transmittance and the greatest influence on the viewing angle dependency of the liquid crystal display device.
Further, the red paint film of the present invention, the ratio of the peak intensity of the plane index (020) to the peak intensity _{(I 111)} of the plane index (111) in X-ray diffraction spectrum _{(I 020) (I} 020 _{/ I 111)} is 7 or more, preferably 7.7 or more, and particularly preferably 7.7 to 15.2.

Next, the color filter of the present invention will be described.
The color filter of the present invention comprises a red filter segment formed from the red coloring composition of the present invention on a transparent substrate. A typical color filter comprises at least one red filter segment, at least one green filter segment, and at least one blue filter segment, or at least one magenta filter segment, at least one cyan filter segment, And at least one yellow filter segment. Further, each filter segment is divided by a black matrix.

As the transparent substrate, glass plates such as soda lime glass, low alkali borosilicate glass and non-alkali alumino borosilicate glass, and resin plates such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate are used. In addition, a transparent electrode made of indium oxide, tin oxide, or the like may be formed on the surface of the glass plate or the resin plate in order to drive the liquid crystal after forming the panel.
The dry film thickness of the filter segment and the black matrix is preferably 0.2 to 10 μm, more preferably 0.2 to 4 μm. When drying the coating film, a vacuum dryer, a convection oven, an IR oven, a hot plate, or the like may be used.

  Examples of the method for forming each color filter segment include a photolithography method, a printing method, and an ink jet method. In particular, a photolithography method and an ink jet method are preferable.

The photolithography method is performed by the following method. That is, the photosensitive coloring composition prepared as a solvent developing type or alkali developing type colored resist material has a dry film thickness of 0. 0 on a transparent substrate by a coating method such as spray coating, spin coating, slit coating or roll coating. It apply | coats so that it may become 2-10 micrometers. If necessary, the dried film is exposed to ultraviolet light through a mask having a predetermined pattern provided in contact with or non-contact with the film. Thereafter, the filter segment and the black matrix can be formed by immersing in a solvent or an alkali developer or spraying the developer by spraying or the like to remove uncured portions and forming a desired pattern. Furthermore, in order to accelerate the polymerization of the colored resist material, heating can be performed as necessary.
In development, an aqueous solution such as sodium carbonate or sodium hydroxide is used as an alkali developer, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution.
As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a paddle (liquid accumulation) development method, or the like can be applied.
In order to increase the UV exposure sensitivity, the colored resist material is applied and dried, and then a water-soluble or alkali-soluble resin such as polyvinyl alcohol or water-soluble acrylic resin is applied and dried to form a film that prevents polymerization inhibition by oxygen. Then, ultraviolet exposure can be performed.

Next, the filter segment in the ink jet method is an ink jet ink made of the red coloring composition of the present invention or an ink jet ink of another color in an area separated by the black matrix of the substrate on which the black matrix is formed. It is formed by discharging.
The black matrix is formed by, for example, a photolithography method in which a radical polymerization type black resist is applied, exposed, developed, and patterned, a printing method in which black ink is printed, or a vapor deposition method in which metal is evaporated and then etched. It can be formed on a substrate.

  The red coloring composition and the red coating film of the present invention are not only a color filter but also a front plate or polarizing plate of various display devices such as a flat display panel (liquid crystal display, plasma display, electrochromic display, light emitting diode display, etc.) Or it can utilize for these input devices. Besides, it can be widely used for optical glass, vehicle glass, optical lens, optical recording disc (compact disc, DVD disc, Blu-ray disc, etc.), light case and the like.

  Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto. In Examples and Comparative Examples, “parts” and “%” represent “parts by weight” and “% by weight”, respectively. Further, the number average molecular weight and the weight average molecular weight are values in terms of polystyrene measured by GPC (gel permeation chromatography).

<Production of diketopyrrolopyrrole pigment>
[Production Example 1]
(Acid pasting step) 100 parts of diketopyrrolopyrrole pigment (CI Pigment Red 254, "Irgafore Red B-CF" manufactured by Ciba Specialty Chemicals) is dissolved in 800 parts of 98% sulfuric acid, and the sulfuric acid of the pigment It was set as the solution. Next, 20 parts of chlorobenzene, 2 parts of a nonionic surfactant (“Newcol B13” manufactured by Nippon Emulsifier Co., Ltd.) and 20 parts of water were mixed with a high speed mixer to prepare an aqueous emulsion. Further, an aqueous emulsion was added to 10,000 parts of stirring water, and subsequently a sulfuric acid solution of the pigment was slowly added to obtain an aqueous slurry of the pigment. The obtained pigment slurry was heated at 80 ° C. for 1 hour, filtered, washed with water and dried to obtain 95 parts of treated pigment (A) heat-treated with an aqueous emulsion.
(Salt Milling Step) 90 parts of the treated pigment (A), 900 parts of sodium chloride (B), and 110 parts of diethylene glycol (C) were charged into a kneader (“1 gallon kneader” manufactured by Inoue Seisakusho Co., Ltd.), and 50 The mixture was kneaded at a temperature of 15 hours. Next, the kneaded mixture is poured into warm water and stirred at a high speed mixer for 1 hour while being heated to about 80 ° C. to make a slurry, filtered, washed with water to remove salt and diethylene glycol, and then dried at 80 ° C. overnight. Thereafter, it was pulverized to obtain 86 parts of a fine diketopyrrolopyrrole pigment.

[Production Example 2]
85 parts of fine diketopyrrolopyrrole pigment was obtained in the same manner as in Production Example 1 except that the addition of the aqueous emulsion and the heat treatment step were omitted.

<Production of red coloring composition>
According to the composition of Table 1, the red coloring composition of Examples 1-3 and Comparative Examples 1-2 was manufactured.
Example 1
Using the refined diketopyrrolopyrrole pigment of Production Example 1, the formulation in Table 1 was weighed and applied to a continuous bead mill type disperser for 4 hours, and then filtered through a 1 μm filter to obtain a red colored composition. This red coloring composition was coated on a 100 × 100 mm, 11 mm thick glass substrate with a spin coater, dried at 70 ° C. for 15 minutes, and then heated at 230 ° C. for 20 minutes to obtain a red coating film. The evaluation results of the coating film are shown in Table 2.

(Comparative Example 1)
A red coloring composition and a red coating film were obtained in the same manner as in Example 1 except that a commercially available diketopyrrolopyrrole ("Irga Fore Red B-CF" manufactured by Ciba Specialty Chemicals) was used.

(Comparative Example 2)
A red colored composition and a red coating film were obtained in the same manner as in Example 1 except that the diketopyrrolopyrrole of Production Example 2 was used.

Formula (2)

<Evaluation method>
(Average primary particle size)
From the image observed with a transmission electron microscope (“JEM-1010” manufactured by JEOL Ltd.), the red coloring composition was diluted 200 times with propylene glycol monomethyl ether acetate, placed on a mesh with a collodion support film, and sampled. Asked.

(contrast)
In the red coating film obtained in Example 1 and Comparative Examples 1 and 2, when the chromaticity at the C light source is x = 0.65 using a microspectrophotometer ("OSP-SP100" manufactured by Olympus Optical Co., Ltd.) The value of was obtained. The contrast was measured using a “color luminance meter BM-5A” manufactured by Topcon Corporation. Further, “deflection film LLC2-92-18” manufactured by Sanritsu Co., Ltd. was used as the deflection plate. In the measurement, in order to block unnecessary light, the measurement was performed by applying a black mask with a 1 cm square hole in the measurement portion. The luminance when the polarizing plate was parallel and the luminance when it was perpendicular were measured, and the contrast ratio was calculated from the following formula (3).
Contrast ratio = parallel brightness / direct brightness formula (3)

(X-ray diffraction spectrum measurement)
Measurement was performed using “X'PertPRO” manufactured by Philips. In the red coating films of Example 1 and Comparative Examples 1 and 2, since the influence of the glass plate appears, peak separation was performed to remove the influence, and peak intensities of 7.5 ° and 24.7 ° were obtained. .

(Retardation)
A three-dimensional refractive index measurement is performed using an ellipsometer (“M-220S” manufactured by JASCO Corporation), and the value obtained by a stylus type film thickness meter is inserted into the value of the film thickness, and the refractive indices nx, ny and nz was obtained and obtained by multiplying the above-mentioned film thickness values.

  As shown in Table 2, the red coating film of Example 1 has a high ratio (020) / (111) between the (020) plane and the (111) plane of the X-ray diffraction spectrum, a high CR, and a negative retardation. With the sign of In Comparative Example 1, the ratio (020) / (111) between the (020) plane and the (111) plane is high and the retardation is negative, but since the primary particle diameter of the pigment is large, the CR is low. In Comparative Example 2, the CR is high, but the ratio (020) / (111) between the (020) plane and the (111) plane is low, and the retardation is a positive value.

It is a figure which shows the powder X-ray-diffraction result of a diketopyrrolopyrrole pigment. It is a figure which shows the X-ray-diffraction result at the time of making the red coloring composition of this invention into a coating film. It is a diagram showing the relationship between the retardation and the _I 020 _{/ I 111} in the red coating of the present invention.

Claims (6)

X-ray diffraction of a coating film when it is formed into a red colored composition comprising a diketopyrrolopyrrole pigment having an average primary particle size of 40 nm or less and a pigment carrier comprising a resin, its precursor or a mixture thereof In the spectrum, the ratio (I ₀₂₀ / I ₋₁₅₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₋₁₅₁ ) of the plane index ( ₋₁₅₁ ) is 2 or more. Red coloring composition. X-ray diffraction of a coating film when it is formed into a red colored composition comprising a diketopyrrolopyrrole pigment having an average primary particle size of 40 nm or less and a pigment carrier comprising a resin, its precursor or a mixture thereof In the spectrum, the ratio (I ₀₂₀ / I ₁₁₁ ) of the peak intensity (I ₀₂₀ ) of the plane index (020) to the peak intensity (I ₁₁₁ ) of the plane index ( ₁₁₁ ) is 7 or more. Composition.   A solvent salt milling method in which a diketopyrrolopyrrole pigment is kneaded with a mixture of a pigment (A) heat-treated with an aqueous emulsion of a crystallization solvent, a grinding aid (B), and a water-soluble organic solvent (C). The red coloring composition according to claim 1, wherein the red coloring composition is refined. A red coating film using a diketopyrrolopyrrole pigment having an average primary particle size of 40 nm or less and a pigment carrier comprising a resin, a precursor thereof or a mixture thereof, and having an area index (111) in an X-ray diffraction spectrum and the ratio of the peak intensity peak intensity of plane index (020) for _{(I 111) (I 020)} (I 020 / I 111) of 7 or more, the film thickness is not more 4μm or less and a retardation in the 590nm -120 A red coating film characterized by being -0.   A solvent salt milling method in which a diketopyrrolopyrrole pigment is kneaded with a mixture of a pigment (A) heat-treated with an aqueous emulsion of a crystallization solvent, a grinding aid (B), and a water-soluble organic solvent (C). The red coating film according to claim 4, wherein the red coating film is refined. A color filter using the red coating film according to claim 4.

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