JP2005234009A - Blue pigment composition for color filter, its manufacturing method, and color filter containing the same in blue pixel portion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a blue pigment composition for a color filter and a method for manufacturing the composition having excellent fluidity and storage stability of a pigment dispersion liquid, to provide a color filter having excellent contrast of a coating film by using the above pigment composition, having excellent heat resistance while keeping the initial sharpness and brightness of the coating film. <P>SOLUTION: The blue pigment composition for a color filter contains a ε-type copper phthalocyanine fine pigment, wherein the ε-type copper phthalocyanine fine pigment contains a sulfonic acid amide derivative of copper phthalocyanine, a phthalimidemethyl derivative of copper phthalocyanine, and a derivative containing a sulfonic acid or its salt of copper phthalocyanine, and has 95 to 150 m<SP>2</SP>/g BET specific surface area measured by a nitrogen adsorption method and 0.01 to 0.06 μm average particle diameter of primary particles. The invention discloses the method for manufacturing the above pigment composition and a color filter containing the above pigment composition in a blue pixel portion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a blue pigment composition for a color filter used for a liquid crystal color display, a video camera, a color electroluminescent display, and the like, a method for producing the same, and a color filter containing the blue pigment composition.

  A color filter used in a liquid crystal display device is formed by forming red, green, and blue colored pixel portions (also referred to as a pattern) on a transparent substrate such as glass. In general, it is difficult to obtain a spectral transmission spectrum as a color filter with only a single pigment, and it is necessary to adjust using two or more pigments.

  That is, as a material constituting the blue pixel portion, C.I. I. Pigment Blue 15: 6 (hereinafter referred to as ε-type copper phthalocyanine pigment) is used, but it is difficult to obtain a sufficient spectral transmission spectrum with a single ε-type copper phthalocyanine pigment. The spectral transmission spectrum is adjusted by mixing with pigments or reddish purple pigments.

  The ε-type copper phthalocyanine pigment has the strongest diffraction peak at a Bragg angle 2θ (allowable range ± 0.2 degrees) = 9.2 degrees according to an X-ray diffraction diagram (CuKα ray), which is higher than that of an α-type copper phthalocyanine pigment. Furthermore, it has an excellent property that it has a reddish hue, high vividness, high coloring power, and more stability against crystal transition.

  The ε-type copper phthalocyanine pigment has a small specific surface area in a known and conventional production method, and when this is used for a color filter blue pixel portion, the primary particle diameter of the pigment is large, so that the sharpness, brightness, and contrast of the coating film are increased. In either case, a low color filter blue pixel portion was obtained.

  Therefore, by increasing the specific surface area (miniaturization) than before, when used in the color filter blue pixel part, the effect of improving the sharpness, brightness, and contrast of the coating film can be seen to some extent, but the pigment dispersion is still When the pigment dispersion is prepared using the pigment, the pigment particles are re-agglomerated, resulting in an unstable state with high viscosity and insufficient fluidity and storage stability. Become. And the color filter blue pixel part using this pigment dispersion has the fault that all of the sharpness, brightness, contrast, and heat resistance of a coating film are low (for example, refer patent document 1).

  In addition, as a blue pigment composition, an ε-type copper phthalocyanine pigment is blended with a 2,9-dimethylquinacridone pigment having a reddish hue than copper phthalocyanine in the state of a colorant. However, the coloration of these mixed pigments is subtractive color development, and when these mixed pigments are used in the color filter blue pixel area, the sharpness, brightness, and contrast of the coating film in the blue region are reduced, and the transmittance is reduced. It had the disadvantage of being unavoidable.

  In addition, as a blue pigment composition, α-type copper phthalocyanine, carbazole dioxazine violet, phthalimidomethyl derivative of copper phthalocyanine, and solvent salt milling treatment in a mixed system of sulfonic acid derivatives of copper phthalocyanine are used to convert α-type copper phthalocyanine to ε-type. The crystals were converted, and then surface-treated with the sulfonic acid derivative of copper phthalocyanine to obtain an ε-type copper phthalocyanine fine pigment. However, this ε-type copper phthalocyanine fine pigment contains carbazole dioxazine violet, which has poor dispersibility, and further uses α-type copper phthalocyanine as the main raw material, so the pigment has low stability against crystal transition, and the fine pigment The fluidity and storage stability of pigment dispersions using pigments are inadequate, and the color filter blue pixels using these pigments have the disadvantages of low sharpness, brightness, contrast, and heat resistance of the coating film. Had.

JP-A-2002-121420 (second page paragraph numbers 0006 to 0010, sixth page paragraph numbers 0059 to 0060, seventh page paragraph numbers 0070 to 0072). JP-A-2001-033616 (claims on the second page, paragraph number 0013 on the third page, paragraph numbers 0015 to 0016 on the same page, paragraph number 0018 on the same page). JP 2001-288385 A (2nd page claim, third page paragraph number 0009, same page paragraph number 0012, fourth page paragraph numbers 0024 to 0025).

  Problems to be solved by the present invention include a blue pigment composition for a color filter excellent in fluidity and storage stability of a pigment dispersion, a method for producing the same, and a coating film when the pigment composition is used in a blue pixel portion. An object of the present invention is to provide a color filter which is excellent in contrast and excellent in heat resistance while maintaining the initial sharpness and brightness of the coating film.

  Therefore, as a result of intensive investigations in view of the above circumstances, the present inventors have performed a solvent salt milling treatment on an ε-type copper phthalocyanine crude pigment containing a sulfonic acid amide derivative of copper phthalocyanine in the presence of a phthalimidomethyl derivative of copper phthalocyanine, By controlling (miniaturizing) the specific surface area of the pigment and the average particle diameter of the primary particles within a certain range, and then subjecting this to a surface treatment with a derivative having a sulfonic acid of copper phthalocyanine or a salt thereof, As a result, the present invention has been completed.

That is, the present invention relates to a blue pigment composition for a color filter containing an ε-type copper phthalocyanine fine pigment, wherein the ε-type copper phthalocyanine fine pigment is a sulfonic acid amide derivative of copper phthalocyanine, a phthalimidomethyl derivative of copper phthalocyanine, and a sulfone of copper phthalocyanine. A blue color filter for a color filter, comprising a derivative having an acid or a salt thereof, having a BET specific surface area of 95 to 150 m ² / g in a nitrogen adsorption method and an average particle diameter of primary particles of 0.01 to 0.06 μm The present invention provides a pigment composition, a method for producing the pigment composition, and a color filter containing the blue pigment composition for a color filter in a blue pixel portion.

According to the blue pigment composition of the present invention, ε-type copper phthalocyanine fine pigment containing a sulfonic acid amide derivative of copper phthalocyanine and a phthalimidomethyl derivative of copper phthalocyanine is surface-treated with a derivative having a sulfonic acid of copper phthalocyanine or a salt thereof. Therefore, the blue pigment is superior to the conventionally known ε-type copper phthalocyanine pigment, the same fine pigment, or the treated pigment, in terms of the fluidity and storage stability of the pigment dispersion forming the blue pixel portion of the color filter. The color filter blue pixel portion prepared using the composition has a particularly remarkable effect of being excellent in the contrast of the coating film and excellent in heat resistance while maintaining the initial sharpness and lightness.
Therefore, the blue pigment composition of the present invention is optimal for forming a color filter blue pixel portion.

  Hereinafter, the present invention will be described in detail.

The blue pigment composition for a color filter of the present invention includes C.I. I. Pigment Blue 15: 6 ε-type copper phthalocyanine fine pigment, and the ε-type copper phthalocyanine fine pigment further comprises a sulfonic acid amide derivative of copper phthalocyanine, a phthalimidomethyl derivative of copper phthalocyanine, and a sulfonic acid of copper phthalocyanine or And a derivative having the salt, having a BET specific surface area of 95 to 150 m ² / g in a nitrogen adsorption method and an average primary particle diameter of 0.01 to 0.06 μm.

  The ε-type copper phthalocyanine fine pigment is obtained by subjecting a crude ε-type copper phthalocyanine pigment containing a sulfonic amide derivative of copper phthalocyanine to a solvent salt milling treatment in the presence of a phthalimidomethyl derivative of copper phthalocyanine, and then treating the sulfonic acid of copper phthalocyanine. Alternatively, the surface is treated with a derivative having a salt thereof.

  The crude pigment is an ε-type copper phthalocyanine crude pigment (containing a specific amount of a sulfonic acid amide derivative of copper phthalocyanine described later) that is directly synthesized without passing through α-type copper phthalocyanine. It means ε-type copper phthalocyanine having an average particle diameter of 50 to 0.1 μm.

  Here, as a direct production method of the ε-type copper phthalocyanine crude pigment that does not pass through the α-type copper phthalocyanine, any known conventional method for producing the ε-type copper phthalocyanine crude pigment in the presence of a sulfonic acid amide derivative of copper phthalocyanine is used. Can also be adopted. The ε-type copper phthalocyanine crude pigment synthesized directly in the presence of copper phthalocyanine sulfonic acid amide derivative has a high content of ε-type copper phthalocyanine, so it can suppress the crystal transition to other crystal types by heating (crystal stability Is preferable). The copper phthalocyanine derivative including the sulfonic acid amide derivative of copper phthalocyanine will be described in detail later.

  As such a production method, for example, in a nitrobenzene solvent described in JP-A-53-39325, phthalic anhydride, urea, a copper salt and a reaction catalyst are mixed with a sulfonic acid amide derivative of copper phthalocyanine (copper phthalocyanine). In the presence of a condensation reaction product of sulfochloride and dehydroabiethylamine), or in an alkylbenzene solvent described in JP-A-57-149358, phthalic anhydride, urea, and a copper salt And a method in which the reaction catalyst is synthesized by heating and stirring in the presence of ε-type copper phthalocyanine as a seed crystal with a copper phthalocyanine sulfoamide derivative.

  The crude ε-type copper phthalocyanine pigment thus obtained is then subjected to a pigmentation treatment (also called a finishing treatment). The pigmentation method is not particularly limited, and a known and conventional pigmentation method can be employed. Among these, a pigment having a specific surface area in a suitable range described below and an average particle diameter of primary particles can be suppressed more easily than the solvent method in which the crude pigment is heated and stirred in a large excess of an organic solvent. In order to obtain a finer pigment), it is preferable to employ a solvent salt milling treatment.

  This pigmented ε-type copper phthalocyanine fine pigment improves the dispersibility and dispersion stability of the pigment compared to before pigmentation, but is still insufficient, and when this is used to prepare a pigment dispersion Then, reaggregation of the pigment particles occurs, the viscosity becomes unstable and the fluidity and storage stability are insufficient. And the color filter blue pixel portion using the pigment dispersion is still insufficient, although the effect of improving the contrast, sharpness, brightness and heat resistance of the coating film is seen.

  This solvent salt milling process means kneading and grinding a crude pigment, an inorganic salt, and an organic solvent. Specifically, a crude pigment, an inorganic salt, and an organic solvent that does not dissolve it are charged into a kneader, and kneading and grinding are performed therein. Examples of the kneading means at this time include kneaders such as a kneader and a mix muller.

  As said inorganic salt, water-soluble inorganic salt can be used conveniently, For example, it is preferable to use inorganic salts, such as sodium chloride, potassium chloride, sodium sulfate. Moreover, it is more preferable to use an inorganic salt having an average particle size of 0.3 to 50 μm. Such an inorganic salt can be easily obtained by pulverizing a normal inorganic salt.

  In obtaining a blue pigment composition for a color filter containing an ε-type copper phthalocyanine fine pigment having a specific BET specific surface area defined in the present invention, the amount of inorganic salt used in the crude salt in the solvent salt milling treatment is increased as compared with the conventional method. Is preferred. That is, the amount of the inorganic salt used is preferably 5 to 20 parts per 1 part of the crude pigment in terms of mass, and more preferably 7 to 15 parts.

  As the organic solvent, a water-soluble organic solvent capable of suppressing crystal growth can be suitably used. For example, diethylene glycol, glycerin, ethylene glycol, propylene glycol, liquid polyethylene glycol, liquid polypropylene glycol, 2- (methoxymethoxy) ethanol 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, 1- Methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dip Propylene glycol monomethyl ether, it can be used dipropylene glycol or the like.

  Although the usage-amount of the said water-soluble organic solvent is not specifically limited, 0.01-5 parts per 1 part of crude pigment are preferable in conversion of mass.

  In the method for producing a blue pigment composition for a color filter of the present invention, the directly synthesized ε-type copper phthalocyanine pigment containing a sulfonic acid amide derivative of copper phthalocyanine is subjected to solvent salt milling in the presence of a phthalimidomethyl derivative of copper phthalocyanine. The specific surface area within the range specified by the present invention is the one to treat (here, the crude pigment is subjected to a solvent salt milling treatment in the presence of the pigment derivative). This is preferable in that a fine pigment having an average particle diameter can be obtained in a shorter time.

  When obtaining fine pigments having the same specific surface area and the same primary particle average particle diameter, ε-type copper phthalocyanine crude pigment containing a sulfonic acid amide derivative of copper phthalocyanine is subjected to solvent salt milling in the presence of a phthalimidomethyl derivative of copper phthalocyanine. When the treatment is performed, a fine pigment within the range specified in the present invention can be obtained and the amount of the inorganic salt used is further reduced than when the solvent salt milling treatment is performed in the absence of the phthalimidomethyl derivative of copper phthalocyanine. This is preferable in that it can be performed.

  Examples of the copper phthalocyanine derivative that can be included during the preparation of the crude pigment, during the solvent salt milling process, and during the surface treatment include compounds represented by the following general formula (1) or (2).

  Formula (1)

  Formula (2)

  (In the formula, P represents a residue obtained by removing n hydrogen atoms of an unsubstituted copper phthalocyanine ring. Y represents a sulfonic acid group or a salt thereof with a base or a metal. A represents a divalent linking group. Z represents a residue obtained by removing at least one hydrogen on the nitrogen atom of the primary or secondary amino group, or a residue obtained by removing at least one hydrogen on the nitrogen atom of the heterocyclic ring containing nitrogen. Here, n represents 1-4.)

Examples of the primary and secondary amino groups include a monomethylamino group, a dimethylamino group, and a diethylamino group. Examples of the base or metal that forms a salt with the sulfonic acid group include ammonia, organic bases such as dimethylamine, diethylamine, and triethylamine, and metals such as potassium, sodium, calcium, strontium, and aluminum. . Furthermore, examples of the divalent linking group of A include a divalent linking group such as an alkylene group having 1 to 3 carbon atoms, —SO ₂ —, —SO ₂ NH (CH ₂ ) _m — (here. M represents 1 to 4). Examples of Z include a phthalimide group, a monoalkylamino group, a dialkylamino group, and an N-phenyl group.

Specifically, copper phthalocyanine phthalimidomethyl derivative, sulfonic acid derivative, sodium salt derivative of the sulfonic acid, strontium salt derivative of the sulfonic acid, N-phenylsulfonic acid amide derivative, N- (dialkylaminoalkyl) And sulfonic acid amide derivatives. Of these, the sulfonic acid amide derivative of copper phthalocyanine is preferably the same N-phenylsulfonic acid amide derivative. To these copper phthalocyanine derivatives, amines such as primary amines, secondary amines, tertiary amines, quaternary amine salts, and ethylenediamine can be added and used. The N-phenylsulfonic acid amide derivative, which is a sulfonic acid amide derivative of copper phthalocyanine, will be described in detail later.

  In the blue pigment composition of the present invention, the phthalimidomethyl derivative of copper phthalocyanine contained in the ε-type copper phthalocyanine fine pigment is used during the pigmentation treatment. The derivative is contained in the fine pigment in terms of mass in an amount of 1 to 30 parts per 100 parts of the fine pigment, with 3 to 10 parts being preferred. Moreover, the said derivative | guide_body is preferable at the point which can enlarge a specific surface area and can make the average particle diameter of a primary particle small.

  In the blue pigment composition of the present invention, the sulfonic acid amide derivative of copper phthalocyanine contained in the ε-type copper phthalocyanine fine pigment directly synthesizes the ε-type copper phthalocyanine crude pigment without going through α-type copper phthalocyanine. By-product. The derivative is contained in an amount of 4 to 15 parts in terms of mass per 100 parts of the crude pigment, that is, the same amount per 100 parts of the fine pigment. Especially, it is preferable that it is 4-7 parts per 100 parts of said fine pigments.

  The above-described sulfonic acid amide derivative of copper phthalocyanine has an excellent effect of finely dispersing the pigment, and by using this, the pigment can be finely dispersed without taking much energy and time, and the dispersion can be achieved. The resulting pigment does not agglomerate or settle even over time, and a blue pigment composition for a color filter having excellent dispersibility and dispersion stability over a long period of time can be obtained.

  Examples of the N-phenylsulfonic acid amide derivative of copper phthalocyanine include compounds represented by the following general formula (3).

  Formula (3)

  (In the formula, P represents an unsubstituted copper phthalocyanine residue. M represents a hydrogen atom, an alkali metal atom, or an ammonium group. R1 and R2 represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, and an alkanol group. Ph represents a phenyl group, the number of substituents x and y is 0 to 4, z is 1 to 4, and the sum of x, y, and z is in the range of 1 to 4. (It is preferable that y is close to 0 and z is in the range of 1 to 2).

  Examples of the N-phenylsulfonic acid amide derivative of copper phthalocyanine include a condensation reaction product of copper phthalocyanine sulfonic acid, copper phthalocyanine sulfonic acid such as sulfochloride, or a compound thereof and an aromatic amine. For example, a condensation reaction product of copper phthalocyanine sulfochloride and an aromatic amine can be obtained by treating a copper phthalocyanine crude pigment with chlorosulfonic acid and thionyl chloride and then reacting the produced copper phthalocyanine sulfochloride with an aromatic amine. I can do it. Here, examples of the aromatic amine include aniline, orthotoluidine, paratoluidine, orthochloraniline, methachloroaniline, parachloraniline, orthobromoaniline, metabromoaniline, parabromaniline, orthoanisidine, paraanisidine, 2,4- Examples include dichloroaniline, 3,5-dichloroaniline, 2,4-dibromoaniline, 3,5-dibromoaniline, 2,4-xylidine and the like. In the present invention, as the sulfonic acid amide derivative of copper phthalocyanine, N-phenylsulfonic acid amide of copper phthalocyanine, which is a condensation reaction product of copper phthalocyanine sulfochloride and aniline, is preferable.

  In addition, when the total content of the sulfonic acid amide derivative of copper phthalocyanine does not exceed the above range, the solvent salt milling treatment can be performed by the following method. That is, (1) ε-type copper phthalocyanine crude pigment and a further sulfonic amide derivative of copper phthalocyanine are mixed in advance and subjected to solvent salt milling in the presence of a phthalimidomethyl derivative of copper phthalocyanine. (2) ε-type copper phthalocyanine crude (3) The ε-type copper phthalocyanine crude pigment is further mixed with a sulfonic amide of copper phthalocyanine, which is premixed with a phthalimidomethyl derivative of copper phthalocyanine and subjected to solvent salt milling in the presence of a sulfonic acid amide derivative of copper phthalocyanine. (4) ε-type copper phthalocyanine crude pigment, further copper phthalocyanine sulfonic acid amide derivative and copper phthalocyanine The premixed mixture and Ruimidomechiru derivative to solvent salt milling process.

  Furthermore, in the blue pigment composition of the present invention, a derivative having copper phthalocyanine sulfonic acid or a salt thereof contained in the ε-type copper phthalocyanine fine pigment is used during the surface treatment. The derivative is contained in the fine pigment in terms of mass in an amount of 3 to 15 parts per 100 parts of the fine pigment, with 5 to 10 parts being preferred.

The blue pigment composition for a color filter of the present invention has a mass conversion of 0.01 to 0.00 per one part of an ε-type copper phthalocyanine crude pigment containing 0.04 to 0.15 part of a sulfonic acid amide derivative of copper phthalocyanine. Solvent salt milling using 3 parts of a phthalimidomethyl derivative of copper phthalocyanine and 5 to 20 parts of an inorganic salt followed by removal of the organic solvent and the inorganic salt, followed by 0.1 parts per 1 part of the fine pigment after the milling. It is obtained by surface treatment using a derivative having 03 to 0.15 parts of sulfonic acid of copper phthalocyanine or a salt thereof, and the pigment composition has a BET specific surface area of 95 to 150 m ² / g in a nitrogen adsorption method, The primary particles have an average particle diameter of 0.01 to 0.06 μm.

  The temperature during the solvent salt milling treatment is preferably 30 to 150 ° C, and more preferably 80 to 100 ° C. The time for the solvent salt milling treatment is preferably 3 hours to 20 hours, and more preferably 5 to 15 hours.

Thus, a sulfonic acid amide derivative of copper phthalocyanine of the present invention, an ε-type copper phthalocyanine fine pigment containing the phthalimidomethyl derivative, an inorganic salt, and a mixture containing an organic solvent as a main component are obtained. From this mixture, an organic solvent and an inorganic salt are obtained. Ε-type copper phthalocyanine fine pigment powder containing a derivative of copper phthalocyanine by washing, filtering, drying, pulverizing, etc., solids mainly composed of ε-type copper phthalocyanine fine pigment as necessary Can be obtained. As the cleaning method, either water washing or hot water washing can be employed. At this time, electric conductivity 50 [mu] S / cm ² or less in difference between the water or hot water, preferably to carry out the washing until the 20 [mu] S / cm ² or less. In the case of the mixture using a water-soluble inorganic salt and a water-soluble organic solvent, the organic solvent and the inorganic salt can be easily removed by washing with water.

  The method for surface-treating the ε-type copper phthalocyanine fine pigment obtained by the above operation with a derivative having a sulfonic acid of copper phthalocyanine or a salt thereof is not particularly limited. For example, (1) Pigmentation treatment After adding an aqueous solution of a copper phthalocyanine derivative having a sulfonic acid group or a salt thereof as a functional group to the aqueous slurry of the ε-type copper phthalocyanine fine pigment and stirring and mixing, acid, metal ion or ammonium salt Or an aqueous solution containing a mixture thereof, whereby the surface of the fine pigment is coated with the derivative (pigment slurry dyeing treatment), and (2) the fine pigment and the derivative are powdered together. (3) Add the fine pigment and the derivative during pigmentation (co-polishing) And the like.

  Compared with the methods (1) and (2), the method (3) above sufficiently adsorbs a derivative having a sulfonic acid of copper phthalocyanine or a salt thereof in the vicinity of the particle surface of the ε-type copper phthalocyanine fine pigment, Even if the addition amount of the derivative is small, the dispersibility and dispersion stability of the pigment are improved, and it is preferable in terms of high sharpness, high brightness, and small change with time (storage stability) of the viscosity of the pigment dispersion. Further, the method (1) is not particularly limited. For example, in the aqueous slurry of the pigment, any one of the aqueous solution of the derivative and the acid, metal ion, or ammonium salt is used. Or an aqueous solution containing a mixture of these may be added sequentially, or an aqueous solution previously made into a water-soluble salt of the derivative is added to the aqueous slurry of the pigment, and then the acid, metal ion or ammonium salt is added. An aqueous solution containing any one of these or a mixture thereof may be added. The aqueous slurry after the pigmentation treatment may be once filtered and washed, and then peptized again in water using a mixer, a high-speed dispersion stirrer, an agitator or the like. Further, an aqueous slurry obtained by dispersing a dried pigment powder in water using a dispersion stirrer, a sand mill, a ball mill, an attritor, a paint conditioner, a high speed mixer, or the like may be used. At this time, it is also possible to add alcohol or the like so that the dried powder of the pigment is easily wetted with water.

  The addition amount of the derivative having a sulfonic acid of copper phthalocyanine or a salt thereof to the ε-type copper phthalocyanine fine pigment after the pigmentation treatment is not particularly limited, but the derivative per part of the fine pigment in terms of mass 0.03 to 0.15 part is preferred. If the added amount of the derivative exceeds 0.15 parts, the light wavelength (λmax) at which the light transmittance is maximized moves to the long wavelength side, and this is not preferable.

  Examples of the drying after filtration and washing described above include batch or continuous drying in which the pigment is dehydrated and / or desolvated by heating at 80 to 120 ° C. with a heating source installed in a dryer. Can be mentioned. Examples of the dryer include a box dryer, a band dryer, and a spray dryer.

  Grinding after drying is not an operation to increase the specific surface area or to reduce the average particle size of the primary particles. Specifically, as in the case of drying using a box dryer or a band dryer. When the pigment has a lamp shape or the like, it is performed to break the pigment into powder, and examples thereof include mortar, hammer mill, disc mill, pin mill, jet mill and the like.

Thus, a powder of the blue pigment composition of the present invention having a BET specific surface area of 95 to 150 m ² / g and an average primary particle diameter of 0.01 to 0.06 μm in a nitrogen adsorption method is obtained. The pigment composition can be used for forming a color filter blue pixel portion.

  The blue pigment composition of the present invention having such a specific surface area and an average particle diameter of primary particles has high dispersion and dispersion stability of the pigment in the liquid medium. Since the viscosity is low (excellent in fluidity) and stable, and the viscosity is stable over time (storage stability), it is homogeneous when a color filter blue pixel portion is produced using the pigment composition. It is possible to obtain a color filter which is excellent in contrast by forming a coating film and excellent in heat resistance in a state where the initial sharpness and brightness are maintained. Here, the contrast is the transmitted light intensity when the object to be measured is sandwiched with the polarization directions of the two polarizing plates parallel to each other and the object to be measured is sandwiched with the polarization direction of the two polarizers perpendicular to each other. This is divided by the transmitted light intensity and is also called depolarization.

  Furthermore, since the blue pigment composition of the present invention forms a color filter blue pixel portion to be described later, it is easy to disperse the pigment in the photocurable composition, and the photocurable composition for forming the blue pixel portion of the color filter. The light-shielding property at 365 nm, which is frequently used for curing an object, does not decrease (that is, high transparency), the photo-curing composition does not decrease the photo-curing sensitivity, and a film edge or pattern flow occurs during development. It is preferable because it becomes difficult. Therefore, a color filter blue pixel portion having both high sharpness and lightness of a coating film that has been required in recent years can be obtained more easily.

When the average particle size of the primary particles is less than 0.01 μm, the cohesiveness of the pigment is increased and is difficult to disperse, and when it exceeds 0.06 μm, the sharpness and brightness tend to decrease. In addition, when the BET specific surface area in the nitrogen adsorption method is larger than 150 m ² / g, the dispersibility and dispersion stability of the pigment are reduced in the same manner as described above, and the stability of the pigment dispersion is decreased due to reaggregation of the pigment. Detrimental effects such as a decrease in contrast occur. That is, when the specific surface area and the average particle size of the primary particles deviate from the preferred range, the flowability and storage stability of the pigment dispersion prepared using the pigment, and the coating film of the color filter blue pixel portion It is not preferable in that all of contrast, sharpness, brightness, and heat resistance are lowered.

  The BET specific surface area in the nitrogen adsorption method in the present invention can be measured in accordance with JIS Z 8830-1990 (method for measuring the specific surface area of powder by gas adsorption).

  The average particle diameter of the primary particles in the present invention refers to that of the primary particles of the pigment constituting the aggregate on the two-dimensional image obtained by photographing particles in the field of view with a transmission electron microscope JEM-2010 (manufactured by JEOL Ltd.). This is a value obtained by obtaining the longer diameter (major diameter) of 50 pieces and averaging them. At this time, the blue pigment composition as a sample is ultrasonically dispersed in a solvent, and then the particles are photographed with the microscope. A scanning electron microscope may be used instead of the transmission electron microscope.

  In the blue pigment composition of the present invention (ε-type copper phthalocyanine fine pigment surface-treated with the copper phthalocyanine derivative), the average particle size obtained by performing the pigmentation treatment is the conventional ε-type copper phthalocyanine pigment. Compared with the fine pigment or the treated pigment, the cohesive force of the primary particles is weak, and it has the property of being more easily solved. Electron micrographs can observe primary pigment particles that cannot be observed with conventional pigments.

  Moreover, the primary particle of the blue pigment composition of the present invention further improves the viscosity characteristics in the photocurable composition to be described later when the aspect ratio is 1 to 3, and the flowability of the photocurable composition is improved. As a result of lowering, it is preferable in terms of improving applicability to a transparent substrate for a color filter. In order to obtain the aspect ratio, first, as in the case of obtaining the average particle diameter of the primary particles, the particles in the field of view are photographed with a transmission electron microscope or a scanning electron microscope. Then, for 50 primary particles constituting the aggregate on the two-dimensional image, an average value of the longer diameter (major axis) and the shorter diameter (minor axis) is obtained and calculated using these values. To do. The aspect ratio indicates a numerical value of 1 or more, but the smaller the aspect ratio (closer to 1), the closer to a square as a two-dimensional shape and the closer to a cube as a three-dimensional shape.

  The blue pigment composition of the present invention has an average primary particle size in the above-mentioned range and a narrower particle size distribution of the pigment than the conventional ε-type copper phthalocyanine pigment, the same fine pigment, or its treated pigment. It is sharp (low light scattering due to coarse particles), has little unevenness on the surface of the pigment, and has excellent smoothness. Therefore, the dispersibility and dispersion stability of the pigment are improved, and heat resistance during the production of the color filter blue pixel part. In addition to improving the initial sharpness and brightness of the coating film, it is possible to obtain a color filter blue pixel portion having high transmittance and high contrast.

  The blue pixel portion of the color filter obtained from the blue pigment composition of the present invention is more visually than the blue pixel portion obtained from the conventional ε-type copper phthalocyanine pigment, the same fine pigment, or its treated pigment, as a result of visual evaluation. Furthermore, it is preferable because the hue is reddish and a blue color that is superior in sharpness and brightness is exhibited. Further, it is preferable in that the transmission curve is shifted to the short wavelength side, the transmittance is high, and the color purity of the blue image is improved.

  The blue pigment composition of the present invention is used for the formation of a color filter blue pixel portion, in order to adjust the color to a desired chromaticity (reddish), if necessary, a condensed polycyclic violet pigment, a blue pigment, a red purple A pigment or the like can be used in combination. These pigments are preferably added within a range that does not impair the color characteristics, and those pigments that have undergone surface treatment may be used if necessary. Specifically, dioxazine pigments are used as violet pigments, quinacridone pigments are used as red-purple pigments, selenium pigments (also called anthraquinone pigments) as blue pigments, throcyanine pigments, indigo pigments, phthalocyanines. A pigment or the like can be used. Among these, it is preferable to use a dioxazine pigment in consideration of the total aspect of hue, light resistance, heat resistance, and price. Examples of the dioxazine pigment include C.I. I. Pigment Violet 23, 37 and the like.

  According to the blue pigment composition of the present invention, even when the dioxazine-based pigment described above is used in combination, a small amount is required. Therefore, compared with the conventional case where two or more different color pigments are mixed for color matching, It is possible to obtain a color filter having a blue pixel portion that is less likely to aggregate, has less turbidity, is excellent in color purity, has high brightness, and has high brightness. Furthermore, it is extremely difficult to cause a disadvantage that a portion having the intended chromaticity and hue in the blue pixel portion and a portion that does not occur are formed.

  The color filter blue pixel portion prepared by using the blue pigment composition of the present invention together with a dioxazine pigment is a conventional ε-type copper phthalocyanine pigment having a small specific surface area, the same fine pigment having a large specific surface area, and a processed pigment thereof, or The decrease in brightness when using a liquid crystal display is smaller than that of the same fine pigment with a large specific surface area synthesized from crystals other than the ε-type and its processed pigments combined with dioxazine pigments. Moreover, it is preferable in that the amount of light transmission in the blue region is also increased.

  The blue pigment composition of the present invention can be used for preparing a blue pixel portion of a color filter and a blue pigment for forming the blue pixel portion by a conventionally known method. In producing a color filter blue pixel portion using the blue pigment composition of the present invention, a pigment dispersion method can be suitably employed.

  A typical method in this method is a photolithography method, in which a photocurable composition to be described later is applied to a surface of a transparent substrate for a color filter on which a black matrix is provided, followed by heat drying (prebaking). After that, pattern exposure is performed by irradiating ultraviolet rays through a photomask to cure the photo-curable compound at a location corresponding to the pixel portion, and then developing the unexposed portion with a developer to remove non-pixels. This is a method of removing the portion and fixing the pixel portion to the transparent substrate. In this method, a pixel portion made of a cured colored film of a photocurable composition is formed on a transparent substrate.

A photocurable composition to be described later is prepared for each color of red, green, and blue, and a color filter having colored pixel portions of red, green, and blue at predetermined positions is manufactured by repeating the above-described operation. I can do it. As described above, a blue pixel portion and a blue pigment for forming the blue pixel portion are prepared from the blue pigment composition of the present invention. In addition, in order to prepare the photocurable composition for forming a red pixel part and a green pixel part, a well-known and usual red pigment and green pigment can be used.

  Examples of the pigment for forming the red pixel portion include C.I. I. Pigment Red 177, 209, 254, and the like are pigments for forming a green pixel portion, for example, C.I. I. Pigment Green 7, 10, 10, 36, and the like. A yellow pigment can be used in combination for forming the red pixel portion and the green pixel portion. Thereafter, if necessary, the entire color filter can be heat-treated (post-baked) in order to thermally cure the unreacted photocurable compound.

  Examples of a method for applying a photocurable composition described later on a transparent substrate such as glass include a spin coat method, a roll coat method, and an ink jet method.

  Although the drying conditions of the coating film of the photocurable composition apply | coated to the transparent substrate differ also with the kind of each component, a compounding ratio, etc., they are 50-150 degreeC and are about 1 to 15 minutes normally. This heat treatment is generally referred to as “pre-baking”. Moreover, as light used for photocuring of a photocurable composition, it is preferable to use the ultraviolet-ray or visible light of the wavelength range of 200-500 nm. Various light sources that emit light in this wavelength range can be used.

  Examples of the developing method include a liquid piling method, a dipping method, and a spray method. After exposure and development of the photocurable composition, the transparent substrate on which the necessary color pixel portion is formed is washed with water and dried. The color filter thus obtained is subjected to heat treatment (post-baking) at 100 to 280 ° C. for a predetermined time by a heating device such as a hot plate or an oven to remove volatile components in the coating film and at the same time photocuring. The unreacted photocurable compound remaining in the cured colored film of the curable composition is thermally cured to complete the color filter.

  The above-mentioned photocurable composition (also referred to as a pigment-dispersed photoresist) for forming the blue pixel portion of the color filter includes the blue pigment composition of the present invention, a dispersant, a photocurable compound, and an organic solvent. Can be prepared by mixing these using a thermoplastic resin as necessary. When the colored resin film that forms the blue pixel portion requires toughness that can withstand baking, etc. performed in the actual production of a color filter, a photocurable compound is used in preparing the photocurable composition. In addition, it is essential to use this thermoplastic resin in combination. When a thermoplastic resin is used in combination, it is preferable to use an organic solvent that dissolves it.

  As a method for producing the photocurable composition, the blue pigment composition of the present invention, an organic solvent and a dispersant are used as essential components, and these are mixed and stirred and dispersed so as to be uniform. After preparing a pigment dispersion (also called a colored paste) for forming the blue pixel portion of the color filter, a photocurable compound and, if necessary, a thermoplastic resin and a photopolymerization initiator are added thereto. In addition, the method of using the photocurable composition is common.

  As described above, the blue pigment composition of the present invention used here is an ε-type copper phthalocyanine fine pigment containing a copper phthalocyanine derivative (sulfonic acid amide, phthalimidomethyl, and sulfonic acid or a salt thereof) as described above, and if necessary. Purple pigments can be used in combination.

  Examples of the dispersant include Dispervic 130, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 170 manufactured by Big Chemie, Fuka 46 and Fuka 47 manufactured by Efka, and the like. Further, a leveling agent, a coupling agent, a cationic surfactant, and the like can be used together.

  Examples of the organic solvent include aromatic solvents such as toluene, xylene and methoxybenzene, acetate solvents such as ethyl acetate and butyl acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, and ethoxyethyl propionate. Propionate solvents such as methanol, ethanol solvents such as ethanol, butyl cellosolve, ether solvents such as propylene glycol monomethyl ether, diethylene glycol ethyl ether, diethylene glycol dimethyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, hexane, etc. Aliphatic hydrocarbon solvents, N, N-dimethylformamide, γ-butyrolactam, N-methyl-2-pyrrolidone, a Phosphorus, nitrogen compound-based solvent such as pyridine, .gamma.-lactone solvents butyrolactone, carbamic acid esters such as a mixture of 48:52 of methyl carbamate and ethyl carbamate acid. As the organic solvent, polar solvents such as propionate-based, alcohol-based, ether-based, ketone-based, nitrogen compound-based, and lactone-based solvents that are water-soluble are particularly preferable. When a water-soluble organic solvent is used, water can be used in combination.

  Examples of the thermoplastic resin used for preparing the photocurable composition include urethane resins, acrylic resins, polyamic acid resins, polyimide resins, styrene maleic acid resins, styrene maleic anhydride resins, and the like. It is done.

  Examples of the photocurable compound include 1,6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, bis (acryloxyethoxy) bisphenol A, 3-methylpentanediol di Multifunctional with relatively low molecular weight such as bifunctional monomer such as acrylate, trimethylol propaton triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate Monofunctional, polyester acrylate, polyurethane acrylate, polyether acrylate, etc. It is.

  Examples of the photopolymerization initiator include acetophenone, benzophenone, benzyldimethylketanol, benzoyl peroxide, 2-chlorothioxanthone, 1,3-bis (4′-azidobenzal) -2-propane, 1,3-bis (4 '-Azidobenzal) -2-propane-2'-sulfonic acid, 4,4'-diazidostilbene-2,2'-disulfonic acid and the like.

  Using the respective materials as described above, the blue pigment composition of the present invention is, in terms of mass, 300 to 1000 parts of an organic solvent and 0 to 100 parts of a dispersant per 100 parts of the blue pigment composition. The pigment dispersion can be obtained by stirring and dispersing in a uniform manner. The pigment dispersion is then subjected to 3 to 20 parts of total thermoplastic resin and photocurable compound and 0.05 to 3 parts of light per part of the photocurable compound per part of the blue pigment composition of the present invention. A photo-curable composition for forming a color filter blue pixel portion can be obtained by adding a polymerization initiator and, if necessary, further an organic solvent and stirring and dispersing so as to be uniform.

  As the developer, a publicly known and commonly used organic solvent or alkaline aqueous solution can be used. In particular, when the photocurable composition contains a thermoplastic resin or a photocurable compound, and at least one of them has an acid value and exhibits alkali solubility, the color filter can be washed with an alkaline aqueous solution. This is effective for forming the blue pixel portion.

  Among the pigment dispersion methods, the method for producing the color filter blue pixel portion by the photolithography method has been described in detail, but the color filter blue pixel portion prepared using the blue pigment composition of the present invention is a different electrodeposition method. The color filter may be manufactured by forming a blue pixel portion by a method such as a transfer method, a micelle electrolysis method, or a PVED (Photovoltaic Electrodeposition) method.

  The color filter uses a red pigment composition, a green pigment composition, and a photocurable composition of each color obtained by using the blue pigment composition of the present invention, and a liquid crystal material is placed between a pair of parallel transparent electrodes. The transparent electrode is encapsulated and divided into discontinuous fine sections, and red (R), green (G), and blue (B) are divided into the fine sections divided into a lattice by the black matrix on the transparent electrode. It can be obtained by providing a color filter coloring pixel portion selected from any one of these colors alternately in a pattern, or by forming a color filter coloring pixel portion on a substrate and then providing a transparent electrode. .

  The blue pigment composition of the present invention is most suitable for forming the color filter blue pixel portion as described above.

  The blue pigment composition of the present invention is a blue pigment exhibiting a reddish hue that is superior in vividness and lightness, as well as storage stability and heat resistance. In addition to color filter applications, paints and plastics (resin molded products) It can also be applied to coloring printing ink, rubber, leather, textile printing, electrostatic charge image developing toner, ink jet recording ink, thermal transfer ink and the like.

  Hereinafter, the present invention will be described in detail with reference to production examples, examples, and comparative examples. The present invention is not limited to these examples. Unless otherwise specified, both “part” and “%” are based on mass.

(Production Example 1)
“First Gen Blue EPC” (Epsilon-type copper phthalocyanine crude pigment. Average particle diameter of primary particles 0.1 to 10 μm, BET specific surface area 5 m ² / g by nitrogen adsorption method, manufactured by Dainippon Ink & Chemicals, Inc. Copper phthalocyanine 1 part of a condensation reaction product of sulfochloride and aniline (copper phthalocyanine N-phenylsulfonic acid amide) 0.06 part), 10 parts of crushed sodium chloride, 1 part of diethylene glycol, phthalimidomethyl derivative of copper phthalocyanine 05 parts were charged into a double-arm kneader and kneaded at 80 to 90 ° C. for 10 hours. After kneading, the mixture was taken out into 100 parts of a 1% hydrochloric acid aqueous solution at 80 ° C., stirred for 1 hour, filtered and washed with hot water, and then peptized into 20 parts of warm water to obtain a pigment slurry. 0.05 part of a sodium hydroxide aqueous solution of a copper phthalocyanine sulfonic acid derivative was added to the pigment slurry, and after stirring for 1 hour, hydrochloric acid was added to precipitate the pigment surface. After being kept for 1 hour, it was filtered, washed with warm water, dried and pulverized to obtain a blue pigment composition (a).

About the BET specific surface area by the nitrogen adsorption method of the said blue pigment composition (a), as a result of measuring using the micro soap 4232II by Microdata, Inc., the specific surface area was 110 m < ² > / g. The result of calibration using NIST MO-206-11 (specific surface area 110 ± 7 m ² / g) manufactured by the same company was 113 m ² / g.
Moreover, as a result of measuring the average particle diameter of the primary particles with a transmission electron microscope JEM-2010 (manufactured by JEOL Ltd.), the average particle size was 0.02 μm and the aspect ratio of length and width was 2.

(Production Example 2)
The same procedure as in Production Example 1 was performed except that the pigment slurry after kneader kneading in Production Example 1 was surface-treated with a derivative having a sodium salt of copper phthalocyanine sulfonic acid of 0.07 parts, and the BET ratio by the nitrogen adsorption method was used. A blue pigment composition (b) having a surface area of 110 m ² / g, an average primary particle diameter of 0.02 μm, and a vertical and horizontal aspect ratio of 2 was obtained.

(Production Example 3)
The same procedure as in Production Example 1 was conducted except that the pigment slurry after kneader kneading in Production Example 1 was surface-treated with a derivative having a sodium salt of 0.09 part of copper phthalocyanine sulfonic acid, and the BET ratio by the nitrogen adsorption method was used. A blue pigment composition (c) having a surface area of 110 m ² / g, an average primary particle diameter of 0.02 μm, and a vertical and horizontal aspect ratio of 2 was obtained.

(Production Example 4)
In Production Example 1, the same operation as in Production Example 1 was performed except that the surface treatment was not performed with a derivative having a sodium salt of copper phthalocyanine sulfonic acid after kneader kneading, and a BET specific surface area of 110 m ² / g by a nitrogen adsorption method was obtained. A blue pigment composition (d) having an average primary particle size of 0.02 μm and a vertical / horizontal aspect ratio of 2 was obtained.

(Production Example 5)
An ε-type copper phthalocyanine pigment containing no sulfonic acid amide derivative of copper phthalocyanine obtained according to the method described in Example 1 of JP-A-48-101419 (average particle diameter of primary particles 0.1 μm, nitrogen adsorption method) 1 part of BET specific surface area of 50 m ² / g), 10 parts of crushed sodium chloride, 1 part of diethylene glycol and 0.05 part of phthalimidomethyl derivative of copper phthalocyanine are each charged in a double arm type kneader and heated at 80 ° C. to 90 ° C. for 8 hours. Kneaded. After kneading, the mixture was taken out into 100 parts of a 1% hydrochloric acid aqueous solution at 80 ° C., stirred for 1 hour, filtered and washed with hot water, and then peptized into 20 parts of warm water to obtain a pigment slurry. 0.05 part of an aqueous sodium hydroxide solution of a copper phthalocyanine sulfonic acid derivative was added to the pigment slurry, and after stirring for 1 hour, hydrochloric acid was added to cause precipitation on the pigment surface. After being kept for 1 hour, filtered, washed with warm water, dried and pulverized, a blue pigment composition having a BET specific surface area of 105 m ² / g by nitrogen adsorption method, an average primary particle diameter of 0.02 μm, and a vertical and horizontal aspect ratio of 2 ( e) was obtained.

(Production Example 6)
“First Gen Blue EPC” (Epsilon-type copper phthalocyanine crude pigment. Average particle diameter of primary particles 0.1 to 10 μm, BET specific surface area 5 m ² / g by nitrogen adsorption method, manufactured by Dainippon Ink & Chemicals, Inc. Copper phthalocyanine Condensation reaction product of sulfochloride and aniline (containing 0.06 part of N-phenylsulfonic acid amide of copper phthalocyanine) at an output density of 0.4 kW per liter of grinding space using an attritor mill Dry grinding was performed to obtain a copper phthalocyanine crude pigment (f) which is a mixture of α type and ε type, a BET specific surface area of 3 m ² / g by nitrogen adsorption method, an average primary particle size of 0.02 μm, and α type and ε type.

1 part of the crude copper phthalocyanine pigment (f) obtained in Production Example 6 is put into a mixed solvent consisting of 3 parts of toluene, 1.5 parts of n-butanol and 6.7 parts of water, and heated at an azeotropic temperature for 4 hours. After stirring, the solvent is distilled and recovered, filtered, washed with warm water, and pulverized. A blue pigment composition having a BET specific surface area of 70 m ² / g by nitrogen adsorption method, an average primary particle diameter of 0.10 μm, and a vertical and horizontal aspect ratio of 4 A product (g) was obtained.

  Using the blue pigment composition (a) obtained in Production Example 1 as a blue pigment, a color filter blue pixel portion was produced by photolithography.

  As a method for producing the color filter blue pixel part, 10 parts of a blue pigment composition (a), 2.5 parts of N, N′-dimethylformamide (organic solvent), Dispersic 161 (dispersant manufactured by BYK Chemie) 6.78 Part, 80.80 parts of Euker Ester EEP (Union Carbide organic solvent) is added with 0.5 mmφ Sepul beads, and dispersed with a paint conditioner (manufactured by Toyo Seiki Co., Ltd.) for 1 hour to obtain a pigment dispersion (colored paste). Obtained. 75.00 parts of this pigment dispersion and Aronix M7100 (polyester acrylate resin, manufactured by Toa Gosei Chemical Co., Ltd., corresponding to a photocurable compound) 5.50 parts, KAYARAD DPHA (dipentaerylate hexaacrylate, 5.00 parts by Nippon Kayaku Co., Ltd., corresponding to a photocurable compound.) 5.00 parts, KAYACURE BP-100 (benzophenone, Nippon Kayaku Co., Ltd., corresponding to a photopolymerization initiator) 1.00 parts. 13.5 parts of Euker ester EFP was stirred with a dispersion stirrer to obtain a photocurable composition for forming a blue pixel part of a color filter. The composition was applied to 1 mm thick glass so as to have a dry film thickness of 1 μm.

  Next, pattern exposure with ultraviolet rays was performed through a photomask, and then the unexposed portion was washed with an organic solvent to produce a color filter blue pixel portion.

  A color filter blue pixel portion was produced in the same manner as in Example 1 except that the blue pigment composition (b) obtained in Production Example 2 was used as a blue pigment.

  A color filter blue pixel portion was produced in the same manner as in Example 1 except that the blue pigment composition (c) obtained in Production Example 3 was used as a blue pigment.

  The clarity and lightness (meaning the state before the heat treatment) of the manufactured color filter blue pixel portions of Examples 1 to 3 were visually evaluated. The visual clarity and brightness (meaning the state after the heat treatment) after the blue pixel portion was heat-treated at 230 ° C. for 1 hour were also evaluated visually. The results are shown in Table 1.

(Comparative Example 1)
A color filter blue pixel portion was produced in the same manner as in Example 1 except that the blue pigment composition (d) obtained in Production Example 4 was used as a blue pigment.

(Comparative Example 2)
A color filter blue pixel portion was produced in the same manner as in Example 1 except that the blue pigment composition (e) obtained in Production Example 5 was used as a blue pigment.

(Comparative Example 3)
A color filter blue pixel portion was produced in the same manner as in Example 1 except that the blue pigment composition (g) obtained in Production Example 6 was used as a blue pigment.

  In the same manner as in Examples 1 to 3, the clarity and brightness (meaning the state before the heat treatment) of the color filter blue pixel portions of Comparative Examples 1 to 3 were visually evaluated. The visual clarity and brightness (meaning the state after the heat treatment) after the blue pixel portion was heat-treated at 230 ° C. for 1 hour were also evaluated visually. The results are shown in Table 1.

                            Table 1

In Table 1, the abbreviations suggest the following contents.
Lightness: ◎ is very bright, ○ is bright, Δ is slightly dark, and X is dark.
Sharpness: ◎ is very clear, ○ is clear, △ is slightly dull, × is dull.

  The color filter blue pixel portion after heat treatment in Examples 1 to 3 and Comparative Examples 1 to 3 is installed between two polarizing plates, a light source is installed on one side, and a CCD camera is installed on the opposite side. The brightness was measured. The ratio of luminance (transmitted light intensity) between when the polarization axis was parallel and when it was perpendicular was calculated, and this was evaluated as contrast. The results are shown in Table 2.

            Table 2

(Measurement of viscosity of pigment dispersion for forming color filter blue pixel part)
The viscosity (mPa · s) of each of the pigment dispersions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 was measured by the following method. The pigment dispersion immediately after the preparation was poured into a designated sample cup (1.2 cc), which was set in a VISCOMETER MODEL RL viscometer manufactured by Toki Sangyo Co., Ltd. Measurement was performed under the conditions of 34 ′ × R24 (viscosity range 0.2 to 6000 mPa · s) and a constant temperature bath 20 ° C. The results are shown in Table 3.

              Table 3

  As is apparent from the results of Tables 1 and 2, in the color filter blue pixel portions of Examples 1 to 3, the photocurable composition having extremely weak pigment aggregation and excellent dispersibility and dispersion stability was shortened. It can be prepared in time (due to the low fluidity and storage stability of the pigment dispersion), and the blue pixel part obtained from it has a very high contrast value of the paint film, and the initial sharpness and brightness of the paint film. It was excellent in heat resistance while maintaining

  On the other hand, in the color filter blue pixel portion of Comparative Example 1, a photocurable composition having strong pigment aggregation and poor dispersibility and dispersion stability was prepared (due to the high fluidity and low storage stability of the pigment dispersion). The blue pixel portion obtained therefrom has a low coating contrast value and also has low heat resistance, so the initial sharpness and brightness of the coating film could not be maintained in a good state. In the color filter blue pixel portion of Comparative Example 2, a photocurable composition having excellent dispersibility and dispersion stability was prepared, and the blue pixel portion obtained therefrom had good initial sharpness and lightness of the coating film. However, it was not possible to maintain it because of its low heat resistance. Furthermore, the numerical value of the contrast of the coating film was also low. In the blue pixel portion of the color filter of Comparative Example 3, a photocurable composition having a strong pigment aggregation and inferior dispersibility and dispersion stability was prepared as in Comparative Example 1, and the blue pixel portion obtained therefrom was coated. Since the numerical value of the contrast of the film was low and the heat resistance was also low, the initial sharpness and brightness of the coating film could not be maintained in a good state.

  In addition, each blue pigment of Examples 1 to 3 is a dioxazine pigment C.I. I. The color filter blue pixel portion obtained by the same operation as described above using the pigment composition used in combination with Pigment Violet 23 is more pigment than that using each blue pigment in Comparative Examples 1 to 3 in combination with the dioxazine pigment. Blue pixel part that can be prepared in a shorter time (due to the low fluidity and storage stability of the pigment dispersion), and the photocurable composition with extremely low agglomeration and excellent dispersibility and dispersion stability The coating film had a high contrast value, and was excellent in heat resistance in a state in which the initial sharpness and lightness of the coating film were well maintained.

  As is apparent from the results in Table 3, the pigment dispersions for forming the color filter blue pixel portion of Examples 1 to 3 have a low viscosity immediately after preparation (low fluidity), and the viscosity is low after aging, depending on conditions. Although it changed somewhat, it was a level that can be used sufficiently (no increase in viscosity with time, high storage stability). On the other hand, the pigment dispersions of Comparative Examples 1 and 3 had a high viscosity immediately after preparation and were not dispersible. Even after lapse of time, it could not be dispersed into fine particles with high viscosity, and also caused a gelation phenomenon during storage, so that it was not at a usable level. The pigment dispersion of Comparative Example 2 had a viscosity immediately after production that was higher than that of Examples 1 to 3, and remained in that state even after aging and was not at a usable level.

From the above, the pigment dispersion prepared using the blue pigment composition of the present invention is more dispersible than that of the conventional blue pigment, the same fine pigment, or the treated pigment. Excellent in fluidity and storage stability due to dispersion stability, and when used in the color filter blue pixel area, it is superior in contrast of the coating film, and it is heat resistant while maintaining the initial sharpness and lightness of the coating film. It turned out that it is also excellent in the property. In particular, the contrast of the coating film was improved by about 30 to 40% compared to the conventional case, and the effect was remarkable.
Therefore, the blue pigment composition of the present invention is optimal for forming a color filter blue pixel portion.

Claims (7)

In a blue pigment composition for a color filter containing a ε-type copper phthalocyanine fine pigment, the ε-type copper phthalocyanine fine pigment comprises a sulfonic acid amide derivative of copper phthalocyanine, a phthalimidomethyl derivative of copper phthalocyanine, and a sulfonic acid of copper phthalocyanine or a salt thereof. A blue pigment composition for a color filter, comprising a derivative having a BET specific surface area of 95 to 150 m ² / g in a nitrogen adsorption method and an average primary particle diameter of 0.01 to 0.06 μm.   The ε-type copper phthalocyanine fine pigment is subjected to a solvent salt milling treatment of an ε-type copper phthalocyanine crude pigment containing a sulfonic acid amide derivative of copper phthalocyanine in the presence of a phthalimidomethyl derivative of copper phthalocyanine, and then treated with a sulfonic acid of copper phthalocyanine or The blue pigment composition for a color filter according to claim 1, which is surface-treated with a derivative having a salt thereof.   The ratio of the sulfonic acid amide derivative of copper phthalocyanine, the phthalimidomethyl derivative of copper phthalocyanine, and the derivative having a sulfonic acid of copper phthalocyanine or a salt thereof contained in the ε-type copper phthalocyanine fine pigment in terms of mass is the fine pigment 100 The sulfonic acid amide derivative of copper phthalocyanine is 4 to 15 parts per part, the phthalimidomethyl derivative of copper phthalocyanine is 1 to 30 parts, and the derivative of copper phthalocyanine having a sulfonic acid or a salt thereof is 3 to 15 parts. The blue pigment composition for color filters described in 1.   4. The blue pigment composition for a color filter according to claim 1, wherein the sulfonic acid amide derivative of copper phthalocyanine is a condensation reaction product of sulfonic acid of copper phthalocyanine or a compound thereof and an aromatic amine. 0.01 to 0.3 parts of a phthalimidomethyl derivative of copper phthalocyanine per part of ε-type copper phthalocyanine crude pigment containing 0.04 to 0.15 part of a sulfonic acid amide derivative of copper phthalocyanine in terms of mass, After solvent salt milling using 20 parts of inorganic salt, the organic solvent and inorganic salt are removed, and then 0.03 to 0.15 parts of sulfonic acid of copper phthalocyanine or 1 part of fine pigment after milling or A blue pigment composition for a color filter having a BET specific surface area of 95 to 150 m ² / g in a nitrogen adsorption method and an average primary particle diameter of 0.01 to 0.06 μm, which is surface-treated with a derivative having the salt. Production method.   A color filter comprising the blue pixel portion of the blue pigment composition for a color filter according to any one of claims 1, 2, 3 and 4.   A color filter comprising a blue pixel portion containing the blue pigment composition for a color filter obtained by the production method according to claim 5.