JP2013023561A - Pigment composition for color filter, method for producing the same, and color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pigment composition for a color filter whose hue is hardly changed even when subjected to thermal history at a high temperature and which is excellent in heat resistance, and also to provide a color filter which does not cause lowering of contrast even when carrying out image display for a long time at a high temperature.SOLUTION: The pigment composition for the color filter includes C.I. pigment green 58 (A) and an epoxy crosslinked polyurethane resin (B), and 0.1-10 parts of nonvolatile components of the epoxy crosslinked polyurethane resin (B) is contained per 100 parts of the C.I. pigment green 58 (A) in terms of mass. There is provided a method for producing the pigment composition for the color filter. The color filter is formed by containing the pigment composition for the color filter in a green pixel part.

Description

  The present invention provides a polyhalogenated zinc phthalocyanine pigment composition capable of obtaining a color filter excellent in heat resistance of contrast, a method for producing the same, and a liquid crystal display for a long time at a high temperature containing the pigment composition in a green pixel portion. The present invention also relates to a color filter that can obtain an image with little reduction in contrast.

  As a polyhalogenated metal phthalocyanine pigment, C.I. I. Polyhalogenated zinc phthalocyanine pigments such as CI Pigment Green 58 are known, which exhibit unique properties not found in other polyhalogenated heterometallic phthalocyanine pigments.

  Specifically, application of this polyhalogenated zinc phthalocyanine pigment to a green pixel portion of a color filter of a liquid crystal display device is known. The green pixel part containing this polyhalogenated zinc phthalocyanine pigment has high color purity because Tmax is on the higher wavelength side compared to the conventional green pixel part containing polyhalogenated copper phthalocyanine pigment. Can also be used suitably for high color purity color filters (Patent Document 1).

  Even in this excellent polyhalogenated zinc phthalocyanine pigment, since the heat resistance of luminance is not sufficient, conventionally, a pigment composition in which a linear (linear) polyurethane resin is contained in a polyhalogenated zinc phthalocyanine pigment. The color filter green pixel part which enables the liquid crystal display excellent in the heat resistance of the brightness | luminance by using is used (patent document 2).

JP 2003-161827 A WO2010 / 061830

  However, in the above-described color filter obtained by using a pigment composition in which a linear (linear) polyurethane resin is contained in a polyhalogenated zinc phthalocyanine pigment, the liquid crystal display device receives a thermal history at a high temperature. Although the degree of contrast reduction in image display is suppressed as compared with untreated polyhalogenated zinc phthalocyanine pigments, it is still impossible to avoid the contrast reduction itself, which is not yet satisfactory.

The problem to be solved by the present invention is a polyhalogenated metal phthalocyanine pigment composition suitable for the formation of a green pixel portion of a color filter having a more excellent heat resistance, the hue of which does not change even when subjected to a thermal history at a high temperature. Is to provide.
Further, the problem to be solved by the present invention is to provide a suitable method for producing the pigment composition, and to provide a contrast even when image display is performed at a high temperature for a long time, containing the pigment composition in a green pixel portion. The object is to provide a color filter which does not deteriorate.

  The present inventors have made various polyurethane resins C.I. I. Pigment Green 58 was used to evaluate the change in hue when heat history was applied. By including an epoxy-crosslinked polyurethane resin, compared to the case where an uncrosslinked polyurethane resin was included. In addition, a color filter excellent in heat resistance of contrast can be obtained, and a color filter containing such a polyhalogenated metal phthalocyanine pigment composition in a green pixel portion can display an image for a long time at a high temperature. The present inventors have found that there is no contrast reduction as in the prior art and have completed the present invention.

That is, the present invention relates to C.I. I. Pigment Green 58 (A) and an epoxy-crosslinked polyurethane resin (B), and C.I. I. Provided is a pigment composition for a color filter, wherein the epoxy-crosslinked polyurethane resin (B) has a nonvolatile content of 0.1 to 10 parts per 100 parts of Pigment Green 58 (A).
The present invention also relates to C.I. I. CI Pigment Green 58 (A), an aqueous non-crosslinked polyurethane resin dispersion, and a water-soluble polyfunctional epoxy compound are mixed with C.I. I. The mixture is mixed so that the total of the non-crosslinked polyurethane resin and the water-soluble polyfunctional epoxy compound is 0.1 to 10 parts per 100 parts of Pigment Green 58 (A), and then the liquid medium is removed by crosslinking. A method for producing a color filter pigment composition is provided.
Furthermore, this invention provides the color filter formed by containing the pigment composition for color filters mentioned above or the pigment composition for color filters obtained by the said manufacturing method in a green pixel part.

The pigment composition for a color filter of the present invention includes C.I. I. Since Pigment Green 58 contains an epoxy-crosslinked polyurethane resin, the hue does not change even when subjected to a heat history at a high temperature, and the heat resistance is excellent.
The color filter containing the color filter pigment composition of the present invention has a reduced contrast even when an image is displayed at a high temperature for a long period of time, compared to a color filter containing a conventional polyhalogenated metal phthalocyanine pigment composition. There is a remarkable effect that there is no.

Hereinafter, the present invention will be described in detail. Hereinafter, C.I. I. Pigment Green 58 (A) may be abbreviated as pigment (A) or former pigment (A). Similarly, the epoxy-crosslinked polyurethane resin (B) may be abbreviated as the resin (B) or the latter resin (B).
The pigment composition for a color filter in the present invention includes C.I. I. It contains CI Pigment Green 58 (A) and an epoxy-crosslinked polyurethane resin (B), and is 0.1 to 10 parts of the latter resin (B) per 100 parts of the former pigment (A) on a mass basis. .

  As a result of trial and error, the present inventors included various types of polyurethane resins in the pigment (A) and compared the heat resistance of the photosensitive composition for color filters. As a result, the present inventors contained a small amount of the epoxy-crosslinked polyurethane resin (B). Only the pigment composition thus obtained was found to be excellent in heat resistance when used as a color filter, with a small change in hue even when used for a long time at a specific high temperature, and without a decrease in contrast.

  The pigment (A) in the present invention is C.I. which is a polyhalogenated zinc phthalocyanine pigment. I. Pigment Green 58.

  In the present invention, the color filter pigment (A) has a primary particle average particle size of 0.01 to 0.30 μm, particularly 0.01 to 0.10 μm. I. Pigment Green 58 is preferable.

  In addition, the average particle diameter of the primary particles in the present invention refers to a pigment that forms an aggregate on a two-dimensional image obtained by photographing particles in the field of view with a transmission electron microscope JEM-2010 (manufactured by JEOL Ltd.). For 50 primary particles of A) or the pigment composition of the present invention, the longer diameter (major diameter) is determined and averaged. At this time, the pigment (A) as a sample or the pigment composition of the present invention is ultrasonically dispersed in a solvent and then photographed with a microscope. A scanning electron microscope may be used instead of the transmission electron microscope.

  No epoxy cross-linked polyurethane resin (B), C.I. I. Examples of the pigment green 58 include FASTOGEN (registered trademark) GREEN A-110, A-210, and A-310 manufactured by DIC Corporation.

  C. I. Pigment Green 58 is a C.I. I. Compared to Pigment Green 36, when a color filter is used, the color purity is high, and a higher level of brightness and more ideal RGB color reproducibility can be achieved.

  The epoxy-crosslinked polyurethane resin (B) in the present invention is a polyurethane resin containing a crosslinked site based on the ring opening of an epoxy group and two or more urethane bonds in one molecule as essential components. This epoxy-crosslinked polyurethane resin (B) includes not only urethane bonds but also epoxy-crosslinked polyurethane polyurea resins containing urea bonds.

  Examples of the non-crosslinked polyurethane resin that is a raw material for the epoxy-crosslinked polyurethane resin (B) include polyether polyurethane resins, polyether ester polyurethane resins, polyester polyurethane resins, and the like. After that, it is preferable in that it has excellent heat resistance when used as a color filter to be described later. These non-crosslinked polyurethane resins are crosslinked as will be described later, whereby corresponding epoxy-crosslinked polyurethane resins are obtained.

  The non-crosslinked polyurethane resin is a linear thermoplastic polyurethane resin obtained by reacting only an organic diisocyanate, a diol, and, if necessary, a bifunctional chain extender. However, it is preferable.

  Non-crosslinked polyurethane resin has excellent dispersion stability when the binder resin or monomer used in the preparation of the photosensitive composition described later is a (meth) acrylate resin or a (meth) acrylate ester. It is a polyurethane resin containing a linear aromatic unit containing an aromatic ring in the main chain and an anionic group in that it has excellent film properties such as adhesion and durability after crosslinking. Among them, a polyester-based polyurethane resin obtained by using an aliphatic or alicyclic diisocyanate containing a linear aromatic unit having an aromatic ring in the main chain and an anionic group is more preferable after crosslinking. It is particularly preferable in that it has excellent heat resistance and does not cause a decrease in image contrast when subjected to liquid crystal display for a long time. Here, the anionic group means, for example, an acid group such as a carboxyl group or a sulfonic acid group or a salt obtained by neutralizing these acid groups with a base. The excellent heat resistance of the crosslinked polyurethane resin is discovered for the first time by conducting a heat resistance test described in detail later, and cannot be known from observation under normal conditions without the heat resistance test.

  As this particularly preferred non-crosslinked polyurethane resin, it contains a linear aromatic unit containing the above-mentioned linear aromatic polyester unit, an aromatic ring in the main chain, and an anionic group, and the organic diisocyanate is an aliphatic diisocyanate. Or the polyurethane resin obtained using alicyclic diisocyanate is mentioned. As will be described later, the pigment used when forming the pixel portion of the color filter is generally smaller when the non-crosslinked polyurethane resin is contained than the contrast when the polyurethane resin is not contained. There are C.I. I. When the above-mentioned particularly preferable epoxy-crosslinked polyurethane resin is contained in Pigment Green 58, there is a specificity that the contrast is higher than when the non-crosslinked polyurethane resin is contained.

  The epoxy crosslinked polyurethane resin (B) refers to a non-crosslinked polyurethane resin crosslinked with a polyfunctional epoxy compound. In this crosslinking, the polyfunctional epoxy compound may be subjected to ring-opening polymerization in the presence of the non-crosslinked polyurethane resin, but the non-crosslinked polyurethane resin molecule and the polyfunctional epoxy compound are chemically synthesized without using a special reaction initiator. It is preferable that the anionic group of the non-crosslinked polyurethane resin having an anionic group as described above is reacted with the epoxy group of the polyfunctional epoxy compound in that it can be crosslinked by bonding.

  The pigment composition for a color filter of the present invention includes, for example, C.I. I. Pigment Green 58 (A), a non-crosslinked polyurethane resin aqueous dispersion, and a water-soluble polyfunctional epoxy compound are mixed and then crosslinked to remove the liquid medium.

  The amount of the water-soluble polyfunctional epoxy compound used for the non-crosslinked polyurethane resin varies depending on the content of the functional group capable of reacting with the epoxy group of the non-crosslinked polyurethane resin to be used and the number of functional groups of the water-soluble polyfunctional epoxy compound. The non-crosslinked polyurethane resin has a non-volatile content of 100 parts, and the water-soluble polyfunctional epoxy compound has a non-volatile content of 1 to 10 parts when the color filter green pixel part is prepared with the obtained pigment composition. It is preferable because of its excellent characteristics such as contrast and brightness.

  The epoxy crosslinked polyurethane resin (B) may be used as the pigment composition of the present invention by mixing its non-volatile content with the pigment (A) as it is, but the pigment (A), the non-crosslinked polyurethane resin, and the water-soluble A pigment composition in which a pigment (A) and a resin (B) are mixed more uniformly by mixing a solution or dispersion in which a functional epoxy compound is dissolved or dispersed in a liquid medium and then crosslinking and removing the liquid medium. Product can be prepared. This mixing is preferably performed with stirring. In particular, heating is performed by mixing and stirring a pigment (A), a solution or dispersion in which a non-crosslinked polyurethane resin and a water-soluble polyfunctional epoxy compound are dissolved or dispersed in a liquid medium, and heating. Compared to the case, the resin (B) is more preferable because the surface of the pigment (A) can be more uniformly and reliably coated and the crosslinking reaction can be sufficiently performed. Further, by applying pressure and heating, not only the coating of the resin (B) on the surface of the pigment (A) particles in the case of simple heating, but also the resin in the voids such as the pores of the pigment (A) particles. The penetration of (B) can be promoted, and the effect of coating is further increased.

  At this time, when a liquid medium containing only a water or a water-soluble organic solvent mainly containing water (referred to as an aqueous medium) is used as the liquid medium, the mixing heating is performed using only the organic solvent as the liquid medium. In comparison, the change in the crystal shape and the like of the pigment (A) itself is small and the hue change is small, which is preferable. A dispersion in which a non-crosslinked polyurethane resin is dispersed in an aqueous medium is called a non-crosslinked polyurethane resin aqueous dispersion.

  Examples of the non-crosslinked polyurethane resin used in the present invention include, for example, Hydran (registered trademark) AP-40F, AP-30F, AP-20 (above, manufactured by DIC Corporation), Superflex 460, 460S, Examples thereof include commercially available non-crosslinked polyurethane resin aqueous dispersions such as 126 (above, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.).

  The water-soluble polyfunctional epoxy compound used in the present invention refers to an epoxy compound containing 2 to 6 epoxy groups in the molecule and dissolved in water. Specifically, for example, sorbitol polyglycidyl ether, other reduction or Non-reducing sugar or polysaccharide polyglycidyl ether or cellulose derivative polyglycidyl ether, polyglycerol glycidyl ether, pentaerythritol polyglycidyl ether, trimethylolpropane polyglycidyl ether, glycerol polyglycidyl ether, poly (ethylene glycol) diglycidyl ether, poly (Vinyl alcohol) glycidyl ether, poly (propylene glycol) diglycidyl ether, and the like.

  The water-soluble polyfunctional epoxy compounds as described above are commercially available, for example, as Denasel EX series products of Nagase ChemteX Corporation, but they have completely water-solubility as they are without using an emulsifier separately. In addition, it is preferable to use Denacol EX-500 series or 600 series manufactured by the same company because it is more reactive without using a reaction initiator.

  If a liquid medium (called an aqueous medium) containing only water or water as a main component and containing a water-soluble organic solvent is used as the liquid medium described above, the water-soluble polyfunctional epoxy compound that has not been involved in crosslinking should remain. However, it can be removed by removing the liquid medium.

  In the present invention, the latter non-crosslinked polyurethane resin and the water-soluble polyfunctional epoxy are added to the pigment (A), non-crosslinked polyurethane resin and water-soluble polyfunctional epoxy compound per 100 parts of the former pigment (A) on a mass basis of the nonvolatile content. Mixed so that the total amount with the compound is 0.1 to 10 parts, especially 0.5 to 8 parts, especially 3 to 7 parts in terms of excellent toughness and color filter characteristics of the crosslinked film. After the crosslinking, the liquid medium is preferably removed to produce a pigment composition. The latter non-crosslinked polyurethane resin and water-soluble polyfunctional epoxy compound charged in this way are cross-linked to become an epoxy-crosslinked polyurethane resin, and are mixed with the pigment (A). Without, the pigment (A) remains at least 70% of its non-volatile content on a mass basis.

  The heating of the pigment (A), the non-crosslinked polyurethane resin and the water-soluble polyfunctional epoxy compound is carried out in a range of 30 minutes to 5 hours with stirring at a temperature of 100 to 150 ° C. in a closed system after mixing the two. Can be done. By heating in a closed system in this way, a pressurized state is formed, and as described above, the epoxy-crosslinked polyurethane resin (B) penetrates into the voids of the pigment particles and simply covers only the particle surface. As compared with the above, a more excellent effect is exhibited.

  The non-crosslinked polyurethane resin and the water-soluble polyfunctional epoxy compound mixed with the pigment (A) cause a crosslinking reaction, for example, in the infrared absorption spectrum (IR) at the time of preparation (before heating) and after heating. It can be easily confirmed by the decrease or disappearance of the peak intensity at a specific wave number based on the epoxy group. As another method, since the epoxy crosslinked polyurethane resin has a relatively low solubility in an organic solvent compared to a non-crosslinked polyurethane resin, for example, a change in the amount of resin dissolved when an organic solvent is used before and after crosslinking. The degree of crosslinking can also be determined from Although it is not possible to specify the presence or absence of cross-linking, as a simple method for confirming the adsorption of the epoxy compound to the pigment and the like, since the water-soluble polyfunctional epoxy compound is dissolved in an aqueous medium, gas chromatography (GPC) etc. The degree of crosslinking is estimated from the amount of recovered unreacted water-soluble polyfunctional epoxy compound not involved in crosslinking, which is contained in the aqueous medium after crosslinking, relative to the charged amount before crosslinking. I can do it.

  The mixture thus heated is cooled, for example, and the liquid medium is removed therefrom. If necessary, the solid is washed, filtered, dried, pulverized, etc., so that the pigment (A) and the epoxy crosslinked polyurethane resin are obtained. The powder of the pigment composition of this invention containing (B) can be obtained.

  As washing, either water washing or hot water washing can be employed. The number of washings can be repeated in the range of 1 to 5 times. By washing, the resin (B) not adsorbed on the pigment (A) can be easily removed. If necessary, acid cleaning, alkali cleaning, and solvent cleaning may be performed so as not to change the crystal state. The amount of non-volatile content (so-called yield) of the epoxy-crosslinked polyurethane resin (B), which is an active ingredient, contained in the pigment composition for color filters is, for example, from the amount of resin extracted by solvent extraction of the pigment composition or charged It can be determined from the outflow amount in the filtrate with respect to the total nonvolatile content of the non-crosslinked polyurethane resin and the water-soluble polyfunctional epoxy compound.

  Examples of the drying after filtration and washing described above include batch-type 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. Examples of the dryer generally include a box dryer, a band dryer, and a spray dryer. In particular, spray dry drying is preferable because it is easily dispersed during paste preparation. In addition, the pulverization after drying is not an operation for increasing the specific surface area or reducing the average particle diameter of the primary particles, but for example, the pigment is a lamp as in the case of drying using a box dryer or a band dryer. When it becomes a shape, etc., it is performed in order to break the pigment into powder, and examples thereof include mortar, hammer mill, disc mill, pin mill, jet mill and the like. In this way, a dry powder containing a color filter pigment composition containing the pigment (A) and the resin (B) as a main component is obtained.

  The pigment composition for a color filter of the present invention can be used for any known and commonly used applications. However, when the average particle diameter of primary particles is 0.01 to 0.10 μm, pigment aggregation is relatively weak and coloring is performed. Dispersibility into power synthetic resin and the like becomes better.

  When the color filter pigment composition of the present invention is used for a color filter green pixel portion, the pigment dispersion in the color filter photosensitive composition is easy, and the color filter photosensitive composition is cured. The light-shielding property at 365 nm, which is frequently used in the film, is reduced, the photocuring sensitivity of the resist is not lowered, and film edge and pattern flow during development are less likely to occur. A color filter green pixel portion having both high sharpness and high brightness demanded in recent years can be obtained more easily.

  When the primary particle of the pigment composition for a color filter of the present invention has an aspect ratio of 1 to 3 in the longitudinal and lateral directions, the viscosity characteristics are improved in each application field, and the fluidity is further increased. 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, an average value of the longer diameter (major axis) and the shorter diameter (minor axis) is obtained for 50 primary particles constituting the aggregate on the two-dimensional image, and the average value is calculated using these values. .

  The color filter of the present invention can be obtained by containing the pigment composition for a color filter of the present invention at least in the green pixel portion of the color filter. In the field of color filters, unlike conventional printing inks and paints such as general-purpose applications, the saturation value handling is very strict, and it is difficult to improve the saturation value very slightly. By using this pigment composition for the preparation of a color filter, the color purity is improved and a liquid crystal display device having a wider RGB color reproduction range can be obtained.

  C. I. The pigment composition for a color filter suitable for use in the present invention, which contains CI Pigment Green 58, is used in combination with or without a yellow pigment in particular for color matching when obtaining a green pixel portion of a color filter. Therefore, a decrease in light transmittance in the entire region of 380 to 780 nm can be prevented to a minimum. In particular, since it has a more yellowish color and higher coloring power, if the color density is the same, the yellow pigment may be used in a smaller amount, which is advantageous because the transmittance can be further increased.

  In addition, C.I. I. As described above, the preferred color filter pigment composition of the present invention containing CI Pigment Green 58 has a wavelength (Tmax) at which the transmittance of the spectral transmission spectrum at 380 to 780 nm is maximum, and is 510 to 520 nm. The half-value width of the transmission curve is as sharp as 110 nm or less. (This wavelength is not affected by the photosensitive resin as described later.)

  The spectral transmission spectrum in the present invention is obtained according to the first-class spectrophotometer of Japanese Industrial Standard JIS Z 8722 (color measurement method-reflective and transmissive object color). The resin film containing the pigment composition formed into a dry film thickness is obtained by plotting each transmittance value at each wavelength by scanning and irradiating light in a predetermined wavelength region. The transmittance as a color filter can be determined with higher accuracy by correcting (baseline correction or the like), for example, with a spectral transmission spectrum similarly determined for a film having the same dry film thickness only with a resin.

  The pigment composition for a color filter of the present invention can be used as it is for the production of a green pixel portion of a color filter, but if necessary, in consideration of economy, a known conventional green or yellow pigment or A pigment derivative may be used in combination.

  For the above purpose, C.I. I. In addition to using green pigments such as CI Pigment Green 7 and 36, yellow pigments may be used for toning to bring out characteristics. Examples of yellow pigments that can be used here include C.I. I. And yellow organic pigments such as CI Pigment Yellow 83, 110, 138, 139, 150, 180, and 185.

  The pigment composition for a color filter of the present invention can be used for forming a pattern of a green pixel portion of a color filter by a known method. Typically, a photosensitive composition for a color filter green pixel portion containing the pigment composition for a color filter of the present invention and a photosensitive resin as essential components can be obtained.

  As a method for producing a color filter, for example, this pigment composition for a color filter is dispersed in a dispersion medium made of a photosensitive resin, and then applied onto a transparent substrate such as glass by a spin coating method, a roll coating method, an ink jet method, or the like. There is a method called photolithography in which a coating pattern is applied to the coating film, followed by pattern exposure with ultraviolet rays through a photomask, and then an unexposed portion is washed with a solvent or the like to obtain a green pattern.

In addition, the color filter may be manufactured by forming a pattern of the green pixel portion by an electrodeposition method, a transfer method, a micellar electrolysis method, or a PVED (Photovoltaic Electrodeposition) method. In addition, the pattern of a red pixel part and the pattern of a blue pixel part can also be formed by the same method using a well-known pigment. The color filter pigment composition of the present invention is extremely useful in, for example, a method for producing a color filter in which baking is included in the process because the hue change is small even when subjected to a thermal history.

  In order to prepare the photosensitive composition for the color filter green pixel portion, for example, the pigment composition for the color filter of the present invention, a photosensitive resin, a photopolymerization initiator, and an organic solvent that dissolves the resin are essential. Mix as an ingredient. As the production method, a method of preparing a dispersion liquid using the pigment composition for a color filter of the present invention, an organic solvent, and a dispersant as required, and adding a photosensitive resin or the like to the dispersion liquid is generally used. Is.

  Dispersants used as necessary include, for example, Big Chemie Dispersic (DisperbyK registered trademark) 130, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 170, Efka 46, Efka 47, and the like. It is done. In addition, a revenig rigging 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, propylene glycol monoethyl ether acetate, and ethoxyethyl propionate. Propionate solvents, alcohol solvents such as methanol and ethanol, ether solvents such as butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl ether and diethylene glycol dimethyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, fats such as hexane Group hydrocarbon solvents, N, N-dimethylformamide, γ-butyrolactam, N-methyl-2-pyrrolidone, ani Emissions, nitrogen compound-based solvent such as pyridine, a lactone-based solvents such as γ- butyrolactone, carbamic acid esters such as a mixture of 48:52 of methyl carbamate and ethyl carbamate, there is water. As the organic solvent, polar solvents such as propionate-based, alcohol-based, ether-based, ketone-based, nitrogen compound-based, lactone-based, water and the like that are water-soluble are particularly suitable.

  300 to 1000 parts by mass of an organic solvent and 100 to 100 parts by mass of a dispersant and / or 0 to 20 parts by mass of a phthalocyanine derivative as required per 100 parts by mass of the pigment composition for a color filter of the present invention, A dispersion can be obtained by stirring and dispersing so as to be uniform. Subsequently, 3 to 20 parts by mass of the photosensitive resin per 1 part by mass of the pigment composition for a color filter of the present invention and 0.05 to 3 parts by mass of a photopolymerization initiator per 1 part by mass of the photosensitive resin are added to the dispersion. Further, if necessary, an organic solvent can be further added and stirred and dispersed so as to be uniform, whereby a photosensitive composition for a color filter green pixel portion can be obtained.

  Examples of photosensitive resins that can be used in this case include urethane resins, acrylic resins, polyamic acid resins, polyimide resins, styrene maleic acid resins, styrene maleic anhydride resins, and the like, Bifunctional monomers such as 1,6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, bis (acryloxyethoxy) bisphenol A, 3-methylpentanediol diacrylate, Trimethylol propaton triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate It includes photopolymerizable monomers such as polyfunctional monomers such as.

  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.

  The thus-prepared photosensitive composition for green color pixel portion of the color filter becomes a color filter by performing pattern exposure with ultraviolet rays through a photomask and then washing the unexposed portion with an organic solvent or alkaline water. Can do.

  The pigment composition for a color filter of the present invention develops a bright green color with a yellowish green color and high coloring power, high color purity and high contrast. Therefore, it is suitable for coloring paints, plastics, printing inks, rubbers, leathers, textile printing, electronic toners, jet inks, thermal transfer inks and the like in addition to the color filters described in detail.

  Next, examples of the present invention will be shown and described in detail. Hereinafter, unless otherwise indicated,% means mass%, and part means mass part.

  20 g of FASTOGEN (registered trademark) GREEN A-110 (CI Pigment Green 58 manufactured by DIC Corporation), and Hydran (registered trademark) AP-40F (polyurethane resin aqueous dispersion manufactured by DIC Corporation. Nonvolatile content (mass conversion) 22.5%, a polyester-based polyurethane resin obtained by using an aliphatic or cycloaliphatic diisocyanate containing a linear aromatic unit having an aromatic ring in the main chain and an anionic group), and Denacol EX -614B (Sorbitol polyglycidyl ether manufactured by Nagase ChemteX Corporation. Mixture containing trifunctional and tetrafunctional glycidyl ether) 0.22 g of ion-exchanged water 500 g was charged into a 1 liter autoclave and stirred. The temperature is raised to 130 ° C over time, and the mixture is heated and stirred at the same temperature for 5 hours. There, in water, it was epoxy crosslinking of the polyurethane resin adsorbed to the pigment.

  Thereafter, the mixture was allowed to cool to room temperature and suction filtered to obtain a solid, and the solid on the filter paper was washed with 4 liters of warm ion-exchanged water. From this washing solution, the unreacted Denacol EX-614B was not detected. The wet cake of the pigment composition thus obtained was dried in a dryer at 90 ° C. for 12 hours and pulverized with a lab mill.

From the amount of resin extracted by solvent extraction of the dried pigment composition thus obtained, at least 80% (in terms of mass) of the charged hydran AP-40F adhered to FASTOGEN (registered trademark) GREEN A-110. It was confirmed that Moreover, the specific absorption based on the epoxy group of Denacol EX-614B which is a water-soluble polyfunctional epoxy compound before bridge | crosslinking was not observed from IR spectrum of this pigment composition measured with high sensitivity. From the above, the obtained pigment composition is composed of epoxy crosslinked polyurethane resin and C.I. I. It was inferred that it contained CI Pigment Green 58.
The average particle diameter of the primary particles of the pigment composition for a color filter was 0.01 to 0.10 μm, and the aspect ratio was in the range of 1 to 3.

<Preparation of composition for color filter green pixel part>
2.48 parts by mass of the dried pigment composition for a color filter obtained in Example 1 above, 1.24 parts by mass of a dispersant BYK-LPN6919 (solid content 60%) manufactured by Big Chemie Japan Co., Ltd., DIC Corporation ) Acrylic Resin Solution Unidic (registered trademark) ZL-295 (solid content 40%) 1.86 parts by mass and propylene glycol monomethyl ether acetate 10.92 parts by mass 0.3 to 0.4 mmφ zircon beads In addition, a colored composition (I) was obtained by dispersing for 3 hours with a paint conditioner manufactured by Toyo Seiki Co., Ltd.
4.0 parts by weight of the obtained colored composition (I), 2.00 parts by weight of propylene glycol monomethyl ether acetate and 2.10 parts by weight of the above Unidic (registered trademark) ZL-295 were stirred with the paint conditioner, A composition for forming a color filter green pixel portion was obtained.

<Production of glass substrate for CF test>
Then, said composition was apply | coated on the glass substrate made from soda glass with a spin coater. The number of rotations of the spin coater was 600, 800, 1000, and 1200 rpm, and four types of glass plates having different coating film thicknesses of the composition were prepared. Each glass plate coated with the composition thus obtained was heated at 90 ° C. for 3 minutes to obtain a color filter green pixel portion.

<Evaluation of color filter green pixel part>
Various color filter characteristics were evaluated using the obtained glass substrate.
Hue (x, y) and luminance (Y value) were determined using a microspectrophotometer MCPD-3000 manufactured by Otsuka Electronics Co., Ltd. First, the chromaticity coordinate x value and y value in C light source colorimetry and the Y value in CIE color development chromaticity were measured for each of four types of glass plates having different film thicknesses. Based on this, an x-Y graph consisting of four points was created, and the Y value at y = 0.420 on the approximate line was taken as the luminance. Higher brightness means higher visual brightness.

  For initial contrast, the color filter green pixel part is installed between two polarizing plates, a light source is installed on the outside of the polarizing plate, and a color luminance meter BM-5A made by Topcon Technohouse is installed on the other side. Thus, the luminance was measured when the polarization axes of the two polarizing plates were parallel and perpendicular. A graph of chromaticity coordinates y and contrast is created by measuring the ratio of the luminance at the time of parallel and vertical and the contrast of each glass plate, and measuring four glass plates, and y = 0.420 on the approximate line. The value at is taken as the contrast of the green pixel portion.

  For heat resistance, the glass substrate provided with the color filter green pixel portion for which the initial contrast was measured was placed in a dryer at 230 ° C. for 1 hour, taken out and allowed to cool, and then the contrast was measured in the same manner, and the heat for the initial contrast was measured. The contrast after receiving the history was determined.

[Comparative Example 1]
A pigment composition was prepared in the same manner as in Example 1 except that Denasel EX-614B manufactured by Nagase ChemteX Corporation was not used, and thereafter, in the same manner as in Example 1, <Preparation of Color Filter Green Pixel Part Composition><Production of glass substrate for CF test> and <Evaluation of color filter green pixel portion> were performed.
Based on the amount of resin extracted by solvent extraction of the obtained dried pigment composition, at least 80% (in terms of mass) of the hydran (registered trademark) AP-40F charged was converted into FASTOGEN (registered trademark) GREEN A-110. It was confirmed that they were attached. The primary particles of the pigment composition had an average particle diameter of 0.01 to 0.10 μm and an aspect ratio of 1 to 3.

  The evaluation results of Example 1 and Comparative Example 1 are summarized in Table 1.

Table 1

As is apparent from Table 1, the color filter of Example 1 having a green pixel portion made from the pigment composition for a color filter of the present invention based on contrast contrast after loading of the thermal history of Example 1 and Comparative Example 1 It can be seen that heat resistance is remarkably superior to that having a green pixel portion made from the conventional pigment composition for color filter of Comparative Example 1.
In addition, from the luminance contrast of Example 1 and Comparative Example 1, the color filter of Example 1 having a green pixel portion made from the pigment composition for a color filter of the present invention was compared, both at the initial stage and after loading of the thermal history. It can be seen that the green pixel portion made from the conventional color filter pigment composition of Example 1 has a high luminance as an absolute value and is excellent in heat resistance.

  On the other hand, from a comparison between Example 1 and Comparative Example 1, at first glance, the green pixel portion made from the conventional color filter pigment composition of Comparative Example 1 was made from the color filter pigment composition of the present invention. Compared with the color filter of Example 1 having a green pixel portion, it was made from the conventional pigment composition for color filter of Comparative Example 1 although its absolute value was high and excellent in initial contrast. The contrast of the green pixel portion having a green pixel portion made from the pigment composition for color filter of the present invention is compared with the contrast of the green pixel portion after the thermal history is greatly reduced compared to the initial value. Contrary to the result of Example 1, it can be seen that it has a very unique effect that overturns the conventional wisdom of those skilled in the art that the contrast after loading of thermal history is greatly improved rather than initial. .

  As described above, the color filter pigment composition of the present invention containing an epoxy-crosslinked polyurethane resin is superior in heat resistance, high saturation, and color purity to a conventional color filter pigment composition containing a non-crosslinked polyurethane resin. It has a high chromaticity and a very high coloring power. Therefore, the pigment composition for a color filter of the present invention is optimal for pattern formation of a green pixel portion of a color filter for a large screen such as a more ideal RGB color reproduction range display.

  The present invention provides a color filter that provides a color filter excellent in heat resistance of contrast. I. Pigment Green 58 pigment composition, a simple production method thereof, and a color filter containing the pigment composition in a green pixel portion and capable of obtaining an image with little or no contrast reduction even when liquid crystal display is performed for a long time at a high temperature. Can be provided.

Claims (5)

C. I. Pigment Green 58 (A) and an epoxy-crosslinked polyurethane resin (B), and C.I. I. A pigment composition for a color filter, characterized in that the epoxy crosslinked polyurethane resin (B) has a non-volatile content of 0.1 to 10 parts per 100 parts of Pigment Green 58 (A). The pigment composition for a color filter according to claim 1, wherein the epoxy-crosslinked polyurethane resin (B) is an epoxy-crosslinked polyester polyurethane resin. C. I. CI Pigment Green 58 (A), an aqueous non-crosslinked polyurethane resin dispersion, and a water-soluble polyfunctional epoxy compound are mixed with C.I. I. The mixture is mixed so that the total of the non-crosslinked polyurethane resin and the water-soluble polyfunctional epoxy compound is 0.1 to 10 parts per 100 parts of Pigment Green 58 (A), and then the liquid medium is removed by crosslinking. The manufacturing method of the pigment composition for color filters of Claim 1. The method for producing a pigment composition for a color filter according to claim 3, wherein the non-crosslinked polyurethane resin (B) is a non-crosslinked polyester-based polyurethane resin. A color filter comprising the color pixel pigment composition according to claim 1 or 2 in a green pixel portion.