JP5678513B2 - Pigment composition for color filter, method for producing the same, and color filter - Google Patents

Description

  The present invention relates to a color filter pigment composition, a method for producing the same, and a color filter.

  The color filter of the liquid crystal display device has a red pixel portion (R), a green pixel portion (G), and a blue pixel portion (B). Each of these pixel portions has a structure in which a thin film of a synthetic resin in which an organic pigment is dispersed is provided on a substrate, and organic pigments of red, green, and blue are used as the organic pigment.

  The organic pigment used to create the color filter has characteristics that are completely different from those of conventional general-purpose applications. Specifically, the display screen of the liquid crystal display device can be seen more clearly (high contrast), or the same display screen. There is a demand for making the image brighter (higher brightness). In order to meet such demands, powdered organic pigments that have been refined to have an average primary particle size of 100 nm or less are frequently used.

  In order to meet such a demand, as a method for producing an organic pigment for a color filter, for example, a mixture containing an organic pigment, a synthetic resin that is solid and water-insoluble at room temperature, and a water-soluble organic solvent is used. A method for producing a color filter pigment composition kneaded in the presence is known (see Patent Document 1).

  Patent Document 1 suggests that an epoxy resin or a (meth) acrylic resin is used as a synthetic resin that is solid and water-insoluble at room temperature and used in the kneading (solvent salt milling). And as this epoxy resin, bisphenol type, novolak type, alkylphenol type, resorcin type, polyglycol type, ester type, glycidyl type such as N-glycidylamine, cyclic aliphatic epoxide, etc., (meth) acrylic resin, There are copolymers of monomers of acrylic acid and methacrylic acid and their esters alone or as a mixture, and copolymers with radically polymerizable monomers such as styrene, vinyl acetate, maleic anhydride and the like of 60 mol% or less are described. Has been.

  On the other hand, as a method for producing an organic pigment for a color filter, for example, a pigment composition for a color filter in which a mixture containing an organic pigment, an organic pigment derivative and a water-soluble organic solvent is kneaded in the presence of a water-soluble inorganic salt. A manufacturing method is known (see Patent Document 2).

  In Patent Document 2, as organic pigment derivatives used in the kneading (solvent salt milling), metal-free or metal phthalocyanine phthalimidomethyl derivatives, sulfonic acid derivatives, N- (dialkylamino) methyl derivatives, N- (dialkylaminoalkyl) sulfonic acid amide derivatives and the like are described.

  In addition, since the color filter is generally baked at a high temperature of 230 ° C. or higher, the organic pigment to be used is also required to have a heat resistance of 230 ° C. or higher, and the contrast and brightness are reduced even after baking. There is a need for organic pigments that do not.

  However, when using only a solid and water-insoluble synthetic resin at room temperature or kneading using only an organic pigment derivative as in Patent Documents 1 and 2, an excellent color filter pigment is expected as expected. The actual situation was not obtained.

  In particular, since the color filter is generally baked at a high temperature of 230 ° C. or higher, the organic pigment used is required to have a heat resistance of 230 ° C. or higher. There is a demand for organic pigments that do not decrease.

Japanese Patent Laid-Open No. 7-13015 Japanese Patent Laid-Open No. 2002-121420

  An object of the present invention is to provide a pigment composition for a color filter in which the decrease in contrast and brightness is small even after firing.

  The inventors of the present invention have intensively studied in view of the above circumstances, and, when performing the kneading (solvent salt milling), use a specific solid epoxy resin as a synthetic resin that is solid and water-insoluble at room temperature, and an organic pigment. It was found that by using an organic pigment derivative in combination with the organic pigment derivative, a synergistic effect was achieved by the combined use of the resin and the derivative, and all the above problems could be solved, and the present invention was completed.

  That is, the present invention provides a pigment composition for a color filter containing an organic pigment and a resin, containing at least one solid epoxy resin selected from the group represented by the following general formulas 1 to 4 as a resin, Provided is a pigment composition for a color filter, which also contains a pigment derivative.

General formula 1

(In General Formula 1, m and l are each independently 0 to 12, and m + 1 is 0 to 12. X is a divalent linking group selected from the group consisting of 2,2-diphenylpropane and bisarylfluorene structures. Represents.)

General formula 2

(In general formula 2, n is 0-12.)

General formula 3

(In General Formula 3, R is H or CH ₃ and p is 0-12.)

Formula 4

(In general formula 4, q is 0-12.)

  Furthermore, the present invention provides a mixture containing an organic pigment, an organic pigment derivative, at least one solid epoxy resin selected from the group represented by the above general formulas 1 to 4 and a water-soluble organic solvent, as a water-soluble inorganic salt. The manufacturing method of the pigment composition for color filters of said 1 including the process of knead | mixing in presence.

  Furthermore, this invention provides the color filter which uses said pigment composition for color filters for a pixel part.

  In the present invention, since a specific solid epoxy resin and an organic pigment derivative are used in combination as a pigment composition for a color filter, a color filter with a smaller decrease in contrast and brightness is produced even after firing in the color filter production process. It has an exceptionally significant technical effect.

Hereinafter, the present invention will be described in detail.
The color filter pigment composition of the present invention is a color filter pigment composition containing an organic pigment and a resin, and contains a specific solid epoxy resin as a resin and further contains an organic pigment derivative.

  As the organic pigment in the present invention, any known and conventional ones can be used. For example, phthalocyanine pigments, dioxazine pigments, azo pigments, quinacridone pigments, selenium pigments, perylene pigments, perinone pigments, phthalone pigments, isoindolinone pigments. Organic pigments such as methine / azomethine pigments, metal complex pigments or diketopyrrolopyrrole pigments, and particularly blue pigments such as phthalocyanine pigments and indanthrone blue pigments. As the phthalocyanine, copper phthalocyanine, metal-free phthalocyanine, zinc phthalocyanine, cobalt phthalocyanine, nickel phthalocyanine, iron phthalocyanine and the like can be used, and copper phthalocyanine is preferable from the viewpoint of hue.

  Examples of quinacridone pigments include: I. Pigment Violet 19, 42, C.I. I. Pigment Red 122, 202, 206, 207, 209, C.I. I. Pigment Orange 48, 49 and the like.

  Examples of the phthalocyanine pigment include C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, C.I. I. Pigment Green 7, 36, 58 and the like.

Examples of selenium pigments include C.I. I. Pigment Blue 60, C.I. I. Pigment Yellow 24, 108, C.I. I. Pigment Red 168, 177, C.I. I. Pigment Orange 40 and the like.
Examples of perylene / perinone pigments include C.I. I. Pigment Violet 29, C.I. I. Pigment Red 123, 149, 178, 179, C.I. I. Pigment Black 31, 32, C.I. I. Pigment Orange 43 and the like.

  Examples of the phthalone pigment include C.I. I. And pigments such as Pigment Yellow 138.

  Examples of the dioxazine pigment include C.I. I. Pigment Violet 23, 37, C.I. I. Pigment Blue 80 or the like.

  Examples of isoindolinone pigments include C.I. I. Pigment Yellow 109, 110, 173, C.I. I. Pigment Orange 61 and the like.

  Examples of methine / azomethine pigments include C.I. I. Pigment Yellow 139, 185, C.I. I. Pigment Orange 66, C.I. I. Pigment Brown 38 and the like.

  Examples of the metal complex pigment include C.I. I. Pigment Yellow 150, 129, C.I. I. Pigment Orange 68, C.I. I. And pigments such as Pigment Red 257.

  Examples of the diketopyrrolopyrrole pigment include C.I. I. Pigment Red 254, 255, C.I. I. Pigment Orange 71, 72 and the like.

  Examples of the azo lake pigment include C.I. I. Pigment Red 48: 1, 48: 2, 48: 3, 48: 4, 48: 5, 49: 1, 49: 2, 49: 3, 50: 1, 51: 1 52: 1, 52: 2, 53: 1, 57: 1, 58: 2, 58: 4, 60: 1, 63: 1, 63: 2, 64: 1 200, 211, 238, 239, 240, 243, 245, 247, C.I. I. Pigment Yellow 61, 62: 1, 104, 133, 168, 169, 183, 190, 191, C.I. I. Pigment Orange 17, 17: 1, 19 and 46, and the like.

  Examples of insoluble azo pigments include C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 55, 73, 74, 81, 83, 97, 130, 151, 152, 154, 156, 165, 166, 167, 170, 171, 172, 174, 175, 176, 180, 181, 188, C.I. I. Pigment Orange 16, 36, 60, C.I. I. Pigment Red 5, 22, 22, 31, 112, 146, 150, 171, 175, 176, 183, 185, 208, 213, C.I. I. Pigment Violet 43, 44, C.I. I. Pigment Blue 25, 26 and the like.

  Examples of the condensed azo pigment include C.I. I. Pigment Yellow 93, 94, 95, 128, 166, C.I. I. Pigment Orange 31, C.I. I. Pigment Red 144, 166, 214, 220, 221, 242, 248, 262, C.I. I. Pigment Brown 41, 42 and the like.

  In the present invention, two or more of these organic pigments can be used in combination.

  As the organic pigment to be contained in the color filter pigment composition of the present invention, the epsilon-type phthalocyanine pigment can produce a color filter in which the decrease in contrast and brightness is particularly small after firing in the color filter preparation step. .

  As the ε-type phthalocyanine pigment, a generally known ε-type phthalocyanine pigment can be used. Phthalocyanine pigments are known to have crystal polymorphs such as α-type, β-type, γ-type, ε-type, δ-type, π-type, ρ-type, X-type, and R-type. As the pigment, a copper phthalocyanine pigment which is excellent in heat resistance and has a preferable color tone is preferable. A higher ratio of the ε type can provide a pigment composition for a color filter having excellent heat resistance and a preferable color tone, and the higher the ratio of the ε type in the crystal polymorph, the better.

  Next, in the present invention, a specific solid epoxy resin is used as a synthetic resin that is solid and water-insoluble at room temperature. This specific solid epoxy resin refers to the following.

General formula 1

(In General Formula 1, m and l are each independently 0 to 12, and m + 1 is 0 to 12. X is a divalent linking group selected from the group consisting of 2,2-diphenylpropane and bisarylfluorene structures. Represents.

General formula 2

（一般式２中、nは０〜１２である。）

(In general formula 2, n is 0-12.)

General formula 3

（一般式３中、Ｒは、Ｈ又はＣＨ_３であり、pは０〜１２である。）

(In General Formula 3, R is H or CH ₃ and p is 0-12.)

Formula 4

（一般式４中、qは０〜１２である。）

(In general formula 4, q is 0-12.)

  As the above-mentioned specific solid epoxy resin to be contained in the pigment composition for a color filter of the present invention, a solid in which X is a divalent linking group of either 2,2-diphenylpropane or bisarylfluorene structure in the general formula 1 Compared to other solid epoxy resins used in the present invention, the epoxy resin has a lower contrast reduction even after firing in the color filter preparation step.

  Examples of the organic pigment derivative contained in the color filter pigment composition of the present invention include, for example, phthalimidomethyl derivatives, sulfonic acid derivatives, N- (dialkylamino) methyl derivatives, and N- (dialkylaminoalkyl) sulfonic acid amide derivatives. Etc. can be mentioned. Of course, two or more of these derivatives can be used in combination.

  When the pigment composition of the present invention is prepared by kneading (solvent salting) described later, it is preferable to use a phthalimidomethyl derivative from the viewpoint that stable crystal control can be performed.

  To explain based on the phthalocyanine pigment, the phthalimidomethyl derivative of the phthalocyanine pigment means a metal phthalocyanine in which a hydrogen atom on the phthalocyanine ring is substituted with at least one phthalimidomethyl group. This phthalocyanine derivative is obtained by reacting metal phthalocyanine with a formaldehyde source and phthalimide under dehydrating conditions, for example using sulfuric acid and / or fuming sulfuric acid medium, as described in US Pat. No. 6,955,523. The average substituent of the substituted phthalimidomethyl group can be used without particular limitation as long as it is at least 1.0, preferably 1.0 to 2.0. There is no particular limitation on the position to be substituted. Moreover, as a metal atom, copper, zinc, cobalt, nickel, iron etc. are mentioned, for example, Among these, copper is preferable. Here, the average number of substituents means the average value of the number of phthalimidomethyl groups substituted on the phthalocyanine ring of the phthalocyanine derivative, and the measurement is performed by infrared absorption spectroscopy.

  Briefly explaining the method for measuring the average number of substituents, the phthalimidomethyl derivative of the above phthalocyanine pigment is mixed with KBr and pressurized to prepare a sample for infrared absorption spectrum, and the infrared absorption spectrum of this sample is measured. This is carried out by calculating the average number of substituents from the ratio of the absorption peak height of 940 cm −1, which is the characteristic absorption, to the absorption peak height of 895 cm −1, which is the characteristic absorption of phthalocyanine. Alternatively, the phthalimidomethyl derivative of the phthalocyanine pigment can be directly subjected to mass spectrometry or high performance liquid chromatography to quantitatively analyze 1 to 4 substituents, and averaged to calculate the average number of substituents.

  The benzene nucleus of the phthalimidomethyl group may be unsubstituted or substituted such as a halogen group, a nitro group, an amino group, a carboxyl group, or a sulfonic acid group. Among these, an unsubstituted form is preferable.

  The pigment composition for a color filter of the present invention comprises 5 to 20 parts of at least one solid epoxy resin selected from the group represented by the general formulas 1 to 4 per 100 parts of the organic pigment in terms of mass, and the organic pigment The derivative can be prepared by containing 1 to 15 parts.

  When the organic pigment is an ε-type phthalocyanine pigment, the content of the phthalocyanine pigment derivative is 4 to 15%, preferably 5 to 12%, in the total 100% in terms of mass. This range is preferable because sufficient heat resistance and influence on the blue hue are small.

  Although the pigment composition for a color filter of the present invention can be prepared by uniformly mixing while heating each of the above components, the specific solid epoxy resin and the organic pigment derivative are added at a finer level. It is preferable to carry out the kneading (solvent salt milling) described later in that the organic pigment particles can be sufficiently surface-treated and can achieve better heat resistance.

  That is, the color filter pigment composition of the present invention is a mixture containing an organic pigment, an organic pigment derivative, at least one solid epoxy resin selected from the group represented by the general formulas 1 to 4 and a water-soluble organic solvent. Is preferably produced by including a step of kneading in the presence of a water-soluble inorganic salt.

  The solvent salt milling means kneading an organic pigment, a water-soluble inorganic salt, and a hydrophilic organic solvent. Specifically, an organic pigment, a water-soluble inorganic salt, and a hydrophilic organic solvent that does not dissolve the organic pigment are charged into a kneader, and kneading and grinding are performed therein. When the conversion of the crystal form is intended in the kneading, a crude pigment having a crystal form different from that after the kneading can be used as the raw material for the kneading. Specifically, the ε-type copper phthalocyanine pigment can be obtained by kneading as described above using a crude α-type copper phthalocyanine pigment as a raw material. When the organic pigment is not intended to be converted into a crystalline form, a commercially available ε-type copper phthalocyanine pigment can be used as a raw material for kneading.

  As the water-soluble inorganic salt, for example, inorganic salts such as sodium chloride, potassium chloride, sodium sulfate and the like are preferably used. Moreover, it is more preferable to use an inorganic salt having an average particle size of 0.5 to 50 μm. Such an inorganic salt can be easily obtained by pulverizing a normal inorganic salt.

  Moreover, it is preferable to set it as 8-20 weight part with respect to 1 weight part of organic pigments, and, as for the usage-amount of the said inorganic salt, it is more preferable to set it as 10-15 weight part.

  As the water-soluble organic solvent, those 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, dipropylene Recall monomethyl ether, dipropylene glycol, triethylene glycol, polyethylene glycol, 1,2-propanediol, 1-methoxy-2-but-propanol or the like can be used, ethylene glycol or diethylene glycol are preferred.

  Although the usage-amount of the said water-soluble organic solvent is not specifically limited, 0.01-5 weight part is preferable with respect to 1 weight part of organic pigments.

  It is preferable to perform kneading | mixing temperature between 60-150 degreeC. When the organic pigment is a copper phthalocyanine pigment, if the temperature is between 80 and 120 ° C., the epsilon conversion rate of ε-type copper phthalocyanine (ε-type crystallization rate contained in copper phthalocyanine) can be increased. Since the reduction in heat resistance, contrast and the like can be reduced, it is preferable as a color filter pigment.

  As an apparatus used for this kneading, there is a kneader, a mix muller, Trimix (trade name) manufactured by Inoue Seisakusho, which is a planetary mixer described in JP-A-2007-100008, and JP-A-4-122778. The continuous twin-screw extruder described above, Miracle KCK manufactured by Asada Tekko Co., Ltd., which is a continuous single-screw kneader described in JP-A-2006-306996, and the like can be used.

  The pigment composition for a color filter of the present invention may contain a free metal and a free metal ion source, but it is preferable that the amount is as small as possible. For example, when the organic pigment is a copper phthalocyanine pigment, it is preferable for the color filter pigment composition of the present invention that the content of copper or a copper ion source is as small as possible because liquid crystal display characteristics are hardly adversely affected. The contained free copper may be free copper remaining when copper phthalocyanine is synthesized or may be produced by decomposition of copper phthalocyanine after synthesis.

  Such a free metal and free metal ion source can be washed with acids as described in JP-A-2008-308605. Examples of the acids used include hydrochloric acid and sulfuric acid, and the concentration of hydrochloric acid and sulfuric acid is preferably 0.5% to 4%. Moreover, the temperature at the time of washing | cleaning has preferable 50-90 degreeC. Moreover, you may wash | clean using water.

  In the case of the pigment composition for a color filter of the present invention containing an ε-type copper phthalocyanine pigment as an organic pigment, the content of free copper is 900 mass ppm or less in the pigment composition in that the heat resistance of the color filter is small. It is preferable that

  The pigment composition for a color filter in the present invention has high dispersibility and dispersion stability in a liquid medium, the viscosity of the pigment dispersion described later is low, and it is dispersed in fine particles, so Newton fluidity is also obtained. When the color filter pixel portion is manufactured with high stability, a uniform coating film can be formed to obtain a color filter with high brightness, contrast and light transmittance.

  Here, in the case of the pigment composition for a color filter of the present invention containing an ε-type copper phthalocyanine pigment as an organic pigment, dioxazine pigments (CI Pigment Violet 23, CI Pigment Violet 37 are used as necessary. CI Pigment Blue 80, etc.) pigments for toning, metal-free or metal phthalocyanine sulfonic acid derivatives, metal-free or metal phthalocyanine N- (dialkylamino) methyl derivatives, metal-free or metal phthalocyanine N- (Dialkylaminoalkyl) sulfonic acid amide derivatives, dioxazine violet sulfonic acid derivatives, indanthrene blue sulfonic acid derivatives, organic pigment derivatives such as phthalocyanine sulfonic acid, etc., Big Chemie's Dispersic 130, Dispersic 161, Dispersive 162, Dispersic 163, Dispersic 170, Dispersic 171, Dispersic 174, Dispersic 180, Dispersic 182, Dispersic 183, Dispersic 184, Dispersic 185, Dispersic 2000, Dispersic 2001, Dispersic 2020, Dispersic 2050, Dispersic 2070, Dispersic 2096, Dispersic 2150, Dispersic LPN21116, Dispersic LPN6919 Efka 46, Efka 47, Efka 452, Efka LP4008, Efka 4009, Efka LP4010, Efka LP4050, LP4055 400, Efka 401, Evka 402, Evka 403, D Fuka 450, Fuka 451, Fuka 453, Fuka 4540, Fuka 4550, Fuka LP4560, Fuka 120, Fuka 150, Fuka 1501, Fuka 1502, Fuka 1503, Lubrizol Sol Sparse 3000, Sol Sparse 9000, Sol Sparse 13240, Sol Sparse 13650, Sol Sparse 13940, Sol sparse 17000, 18000, Sol sparse 20000, Sol sparse 21000, Sol sparse 20000, Sol sparse 26000, Sol sparse 27000, Sol sparse 28000, Sol sparse 32000, Sol sparse 36000, Sol sparse 37000, Sol sparse 38000, Sol sparse 41000, Sol sparse 42000 00, Solsperse 46000, Solsperse 54000, Solsperse 71000, Ajinomoto Co., Inc. Ajisper PB711, Ajisper PB821, Ajisper PB822, Ajisper PB814, Ajisper PN411, Ajisper PA111, etc., acrylic resins, urethane resins, alkyd resins, Natural rosin such as wood rosin, gum rosin, tall oil rosin, polymerized rosin, disproportionated rosin, hydrogenated rosin, oxidized rosin, modified rosin such as maleated rosin, rosinamine, lime rosin, rosin alkylene oxide adduct, rosin alkyd adduct, A synthetic resin that is liquid and water-insoluble at room temperature, such as a rosin derivative such as rosin-modified phenol, can be contained. Addition of these dispersants and resins also contributes to reduction of flocculation, improvement of pigment dispersion stability, and improvement of viscosity characteristics of the dispersion.

  The pigment composition for a color filter of the present invention can be used for forming a color filter pixel portion by a conventionally known method. A typical method for dispersing the composition according to the present invention is a photolithography method, which is a surface on the side provided with a black matrix of a transparent substrate for a color filter. After coating and heat-drying (pre-baking), pattern exposure is performed by irradiating ultraviolet rays through a photomask to cure the photocurable compound at the location corresponding to the pixel portion, and then developing the unexposed portion This is a method of developing with a liquid, removing a non-pixel portion, and fixing the pixel portion to a transparent substrate. In this method, a pixel portion made of a cured colored film of a photocurable composition is formed on a transparent substrate.

  For each color of red, green, and blue, a photocurable composition to be described later is prepared, and the above-described operation is repeated to manufacture a color filter having red, green, and blue colored pixel portions at predetermined positions. be able to. A blue pixel portion can be formed from the pigment composition for a color filter of the present invention containing an ε-type copper phthalocyanine pigment as an organic pigment. 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, 242 and 254 are pigments for forming the green pixel portion, for example, C.I. I. Pigment Green 7, 10, 36, 47, 58 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. Moreover, as light used for photocuring of a photocurable composition, it is preferable to use ultraviolet rays or visible light in the wavelength range of 200 to 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 90 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 colored coating film, and at the same time, light The unreacted photocurable compound remaining in the cured colored film of the curable composition is thermally cured to complete the color filter.

  The specific solid epoxy resin contained in the pigment composition for a color filter of the present invention can suppress the fading of the organic pigment in a smaller amount even after a high-temperature thermal history such as the above-described post-bake. Thus, a liquid crystal display device provided with a color filter including a colored pixel portion can display an image with excellent contrast and brightness.

  A photocurable composition for forming a blue pixel portion of a color filter includes a pigment composition for a color filter of the present invention containing an ε-type copper phthalocyanine pigment as an organic pigment, a dispersant, a photocurable compound, and an organic It can be prepared by using a solvent as an essential component and mixing them 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 color filter 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. First, after preparing a pigment dispersion for forming the pixel portion of the color filter, a photocurable compound and, if necessary, a thermoplastic resin or a photopolymerization initiator are added to the photocurable composition. A method of forming a composition is common.

  Here, as the dispersant and the organic solvent, those described above can be used.

  Examples of the thermoplastic resin used for the preparation of the photocurable composition include urethane resins, acrylic resins, polyamide resins, polyimide resins, styrene maleic acid resins, styrene maleic anhydride resins, and the like. .

  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 Bifunctional monomers such as acrylate, trimethylol propaton triacrylate, pentaerythritol triacrylate, tris [2- (meth) acryloyloxyethyl) isocyanurate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate, etc. Relatively high molecular weight such as low molecular weight polyfunctional monomer, polyester acrylate, polyurethane acrylate, polyether acrylate, etc. Functional monomer.

  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. Examples of commercially available photopolymerization initiators include “Irgacure (trade name) -184”, “Irgacure (trade name) -369”, “Darocur (trade name) -1173” manufactured by Ciba Specialty Chemicals, and BASF Corporation. “Lucirin-TPO”, Nippon Kayaku Co., Ltd. “Kayacure (trade name) DETX”, “Kayacure (trade name) OA”, Stofer “Bicure 10”, “Bicure 55”, Akzo Corporation “Trigonal PI” “Sandray 1000” manufactured by Sand, “Deep” manufactured by Upjohn, and “Biimidazole” manufactured by Kurokin Kasei.

  In addition, a known and usual photosensitizer can be used in combination with the photopolymerization initiator. Examples of the photosensitizer include amines, ureas, compounds having a sulfur atom, compounds having a phosphorus atom, compounds having a chlorine atom, nitriles or other compounds having a nitrogen atom. These can be used alone or in combination of two or more.

  The blending ratio of the photopolymerization initiator is not particularly limited, but is preferably in the range of 0.1 to 30% with respect to the compound having a photopolymerizable or photocurable functional group on a mass basis. If it is less than 0.1%, the photosensitivity at the time of photocuring tends to decrease, and if it exceeds 30%, crystals of the photopolymerization initiator are precipitated when the pigment-dispersed resist coating film is dried. May cause deterioration of film properties.

  Using each of the materials as described above, 300 to 1000 parts of the organic solvent and 1 to 100 parts of the dispersant are uniform per 100 parts of the color filter pigment composition of the present invention on a mass basis. The pigment dispersion can be obtained by stirring and dispersing in the same manner. Next, in this pigment dispersion, the total amount of the thermoplastic resin and the photocurable compound is 3 to 20 parts per part of the pigment composition for a color filter of the present invention, and 0.05 to 3 parts per part of the photocurable compound. A photopolymerization initiator and, if necessary, an organic solvent may be further added, and a photocurable composition for forming a color filter pixel portion can be obtained by stirring and dispersing so as to be uniform.

  As the developer, a 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. It is effective for forming the pixel portion.

  Among the pigment dispersion methods, the method for producing the color filter pixel portion by the photolithography method has been described in detail, but the color filter pixel portion prepared by using the pigment composition for a color filter of the present invention is not limited to other electrodeposition methods, A color filter may be manufactured by forming a blue pixel portion by a transfer method, a micelle electrolysis method, a PVED (Photovoltaic Electrodeposition) method, an ink jet method, a reverse printing method, a thermosetting method, or the like.

  The color filter uses a photocurable composition of each color obtained by using the pigment composition for a color filter of the present invention containing a red pigment, a green pigment, and a blue pigment as an organic pigment, and a pair of parallel transparent electrodes A liquid crystal material is sealed in between, and the transparent electrode is divided into discontinuous fine sections, and any one of red, green, and blue is arranged in each of 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 colors alternately in a pattern, or by forming a color filter coloring pixel portion on a substrate and then providing a transparent electrode.

  The pigment composition for a color filter of the present invention can provide a color pigment dispersion excellent in sharpness and lightness, and in addition to color filter applications, paints, plastics (resin molded products), printing inks, rubber, leather, textile printing, statics It can also be applied to coloring of charge image developing toner, ink jet recording ink, thermal transfer ink and the like.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the range of these Examples from the first. Unless otherwise specified, “part”, “%”, and “ppm” are based on mass.

  85 parts of ε-type copper phthalocyanine pigment (average particle size 80 nm), 5 parts of copper phthalocyanine phthalimidomethyl derivative having an average substituent number of 1.2, 5 parts of copper phthalocyanine phthalimide methyl derivative having an average substituent number of 1.2, Ogsol PG- 100 (Bisarylfluorene epoxy resin manufactured by Osaka Gas Chemical Co., Ltd. In general formula 1, X = bisvalent fluorene obtained by removing two hydrogen atoms of the aryl group outside the fluorene skeleton, m + 1 is 0.) 10 parts, 1000 parts of crushed sodium chloride, and 175 parts of diethylene glycol were kept in a kneader, and the temperature of the contents was kept at 85 to 90 ° C. to complete wet grinding (solvent salt milling) for 7 hours.

  After kneading, it is taken out into 100 parts by weight of 2% hydrochloric acid at 80 ° C., stirred for 1 hour, filtered, and washed with water until the specific conductivity of the filtrate becomes the specific conductivity of raw water + 20 μS / cm or less, thereby obtaining ε-type copper phthalocyanine. A wet cake of the pigment composition was obtained. The obtained wet cake was transferred to a beaker, 3000 parts of water at room temperature was added, and the mixture was stirred and dispersed to obtain a slurry. Subsequently, 5 parts 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 bring the pH of the slurry back to 7 and deposited on 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.

  The resulting blue pigment composition had an average primary particle size of 24.2 nm and a normalized dispersion of 30% according to the small angle X-ray scattering method. In the powder X-ray diffraction, the half width at 7.7 ° was 0.501 °, the half width at 9.3 ° was 0.635 °, and the ε conversion was 68.4%.

  10 parts of the blue pigment composition thus obtained is put into a polybin, and 55 parts of propylene glycol monomethyl ether acetate, 7.0 parts of Dispersic LPN21116 (manufactured by Big Chemie Co., Ltd.), and 0.3-0.4 mmφ sepul beads are added. The mixture was dispersed for 4 hours with a paint conditioner (manufactured by Toyo Seiki Co., Ltd.) to obtain a pigment dispersion.

  75.00 parts of this pigment dispersion, 5.50 parts of polyester acrylate resin (Aronix (trade name) M7100, manufactured by Toa Gosei Chemical Co., Ltd.), dipentaerythritol hexaacrylate (KAYARAD (trade name) DPHA, Nippon Kayaku) 5.00 parts, benzophenone (KAYACURE (trade name) BP-100, manufactured by Nippon Kayaku Co., Ltd.) 1.00 parts, Euker Ester EEP 13.5 parts with a dispersion stirrer, and pore size 1.0 μm And a color resist (photocurable composition) was obtained.

  This color resist was applied to 50 mm × 50 mm, 1 mm thick glass using a spin coater so that the dry film thickness was 2 μm, and then pre-dried at 90 ° C. for 20 minutes to form a coating film. Next, after pattern exposure with ultraviolet rays through a photomask, the unexposed portion was washed in a 0.5% aqueous sodium carbonate solution and baked at 230 ° C. for 90 minutes to obtain a color filter.

The average primary particle size and particle size distribution of the organic pigment are obtained from the small-angle X-ray scattering profile (measured scattering profile) of the organic pigment dispersion based on the small-angle X-ray scattering method disclosed in JP-A-2006-113042. .
In addition, the half width is 7.7 ° and 9.3 ° obtained from powder X-ray diffraction, and the ε conversion ratio is from the same measurement (1-6.8 ° / 7.6 ° relative intensity). Calculated with x100.

  A color filter was prepared in the same manner except that Ogsol PG-100 of Example 1 was changed to Epicron 3050 (bisphenol A type epoxy resin manufactured by DIC Corporation. In general formula 2, n is in the range of 0 to 12). It was created.

Except that Ogsol PG-100 of Example 1 was changed to Epicron N695 (Novolak type epoxy resin manufactured by DIC Corporation. In General Formula 3, R is CH ₃ and p is in the range of 0 to 12). Created a color filter.

  Except that Ogsol PG-100 of Example 1 was changed to Epicron HP-7200H (dicyclopentadiene type epoxy resin manufactured by DIC Corporation. In general formula 4, q is within the range of 0 to 12), A color filter was created.

Comparative Example 1
A color filter was prepared in the same manner except that 5 parts of the copper phthalocyanine phthalimidomethyl derivative having an average number of substituents of 1.2 in Example 1 was not used.

Comparative Example 2
A color filter was prepared in the same manner except that Ogsol PG-100 of Example 1 was not used.

Comparative Example 3
A color filter was prepared in the same manner except that Ogsol PG-100 of Example 1 was replaced with an acrylic resin (acid value = 33 mg KOH / g, Mn = 18000).

  For each color filter obtained above, the contrast and brightness before and after baking at 230 ° C. were measured as follows.

-Contrast value The color filter blue pixel part was installed between two polarizing plates, a light source was installed on one side, and a color luminance meter was installed on the opposite side to measure the luminance. It was calculated from the ratio of luminance (transmitted light intensity) between when the polarization axis was parallel and when it was vertical. A higher contrast value was evaluated as better.

-Luminance The Y value in the C light source in the color filter blue pixel portion was measured for the Olympus microscope MX-50 and the Otsuka Electronics spectrophotometer MCPD-3000 microspectrophotometer CIE color system chromaticity. Higher brightness was evaluated as better.

As can be seen from the comparison between Example 1 and Comparative Examples 1 and 2, it can be seen that the combined use of the specific solid epoxy resin and the organic pigment derivative significantly suppresses the degree of decrease in the contrast after firing.
Moreover, when the solid epoxy resin having the bisarylfluorene structure or the dicyclopentane structure of Example 1 and Example 4 is used, the contrast absolute after firing is more than that when the other solid epoxy resin used in the present invention is used. It can be seen that the value is high.
It is clear that the color filter prepared with the pigment composition using the derivative of the present invention can improve the contrast and luminance values as compared with the conventional case.

Claims (3)

In a pigment composition for a color filter containing an organic pigment and a resin, 5 to 20 at least one solid epoxy resin selected from the group represented by the following general formulas 1 to 4 per 100 parts of the organic pigment in terms of mass is used. A pigment composition for a color filter , wherein the organic pigment derivative contains 1 to 15 parts by weight.
General formula 1

(In General Formula 1, m and l are each independently 0 to 12, and m + 1 is 0 to 12. X is a divalent linking group selected from the group consisting of 2,2-diphenylpropane and bisarylfluorene structures. Represents.)
General formula 2

(In general formula 2, n is 0-12.)
General formula 3

(In General Formula 3, R is H or CH ₃ and p is 0-12.)
Formula 4

(In general formula 4, q is 0-12.) A mixture containing an organic pigment, an organic pigment derivative, at least one solid epoxy resin selected from the group represented by the above general formulas 1 to 4 and a water-soluble organic solvent is kneaded in the presence of a water-soluble inorganic salt. The manufacturing method of the pigment composition for color filters of Claim 1 including a process. A color filter comprising the pixel composition of the pigment composition for a color filter according to claim 1 .