JP5205703B2 - Method for producing pigment dispersion for color filter, paste for color filter and color filter - Google Patents

Description

  The present invention relates to a method for producing a pigment dispersion excellent in dispersion stability, transparency, and productivity, and a color filter paste and a color filter using the dispersion produced by the production method.

  In general, a liquid crystal display device uses a color filter in which a plurality of different colors (for example, three primary colors of red, green, and blue light) are arranged at pixel portions of a transparent substrate. As a method for regularly arranging pixels of multiple colors on a transparent substrate, a photolithographic technique using a photosensitive colored paste, a photolithographic technique combining a non-photosensitive colored paste and a photosensitive positive resist, printing A method using a method, a method using an electrodeposition method, a method using a film transfer method, a method using an inkjet method, and the like are known. Among these, the photolithography technique is generally used in view of the balance between the performance of the color filter such as pattern accuracy, light transmittance and contrast, and the manufacturing yield and cost.

  As a colored paste used for manufacturing a color filter by a photolithography technique, a colored paste in which a pigment is dispersed in a solution of polyamic acid, which is a polyimide precursor, is known (for example, see Patent Documents 1, 2, and 3). A colored paste in which a pigment is dispersed in a resin solution containing polyvinyl alcohol as a main component is also known (see, for example, Patent Document 4). Furthermore, colored pastes in which pigments are dispersed in a resin solution containing acrylic resin as a main component are also known (see, for example, Patent Documents 5, 6, and 7), and these pigment-dispersed colored pastes are generally used for manufacturing color filters. Has been used.

  Usually, before forming the colored layer, a light shielding layer called a black matrix is formed. The black matrix is a lattice-shaped light shielding region arranged between the pixels, and is provided to improve the display contrast of the liquid crystal display device. As the black matrix, a metal thin film (thickness of about 0.1 to 0.2 μm) such as Cr, Al, or Ni, or a multilayer chromium film in which a layer such as chromium oxide or chromium oxynitride is provided between Cr and a transparent substrate is used. However, a resin black matrix using a black paste made of a light shielding agent and a resin may be used from the viewpoint of cost and environmental pollution (for example, see Patent Document 8).

  In recent years, there has been a demand for colored pastes and black pastes (hereinafter simply referred to as “pastes”) as the properties required for color filters, such as transmittance, contrast, and surface smoothness, have improved. The characteristics are also high. In particular, in a pigment-dispersed colored paste, it is important to finely disperse the pigment (see, for example, Patent Documents 9 and 10), and the required particle size is on the order of several tens of nm.

  As a device for finely dispersing a pigment in a solvent, a disperser using a medium (hereinafter referred to as “bead mill”) is known, and examples thereof include a ball mill, an attritor, and a sand mill. The bead mill uses dispersion media. The processing material and dispersion media supplied into the processing tank are stirred with a stirrer, and the motion of the stirrer and dispersion media causes the shear and shear forces applied to the processing material, and The processing material is refined by supplementation and destruction, and the factors affecting the dispersion of the processing material include the diameter of the media, the filling rate into the processing tank, and the agitation for causing the media to collide with the processing material. The rotation speed of the child is dominant.

  In particular, it is known that the diameter of the dispersion medium has a great influence on the grinding efficiency, and that the larger the diameter, the larger the particles and the smaller the smaller the particles, the more efficiently. From this, it is conceivable that a medium having a large diameter and a medium having a small diameter are mixed and dispersed in a single treatment tank. However, when two or more kinds of dispersion media having different diameters are mixed and used, some The processing material reaches the agglomeration limit particle size first due to the influence of the smaller medium, and a part of the processing material is re-agglomerated to cause a problem that the quality of the entire processing material is lowered. Further, the surface of the dispersion medium having a smaller diameter may be scraped or destroyed by the collision of the dispersion medium having a larger diameter. There has been proposed a media agitation type disperser that divides the inside of a processing tank with a single device and reduces the diameter of the media in order to efficiently disperse the media (for example, see Patent Document 11). Since it passes only once through the main body instead of circulation, the mechanism of the apparatus becomes complicated and the problem of re-aggregation is included, so that it is not suitable for circulation dispersion.

  Also, using a media agitating disperser such as a sand mill, the colorant is dispersed in multiple stages, and the diameter of the media in each stage is sequentially reduced within the range of 0.1-1.0 mmφ, and the dispersion can be circulated. The method of performing is known (for example, refer to Patent Document 12). However, it is not preferable to disperse by a multi-stage process of three or more stages because productivity and yield are greatly reduced due to an increase in the number of processes. However, it is difficult to disperse the pigment to the order of several tens of nm even though it is possible to reach a particle size of the order of sub-μm.

Further, as a method for efficiently dispersing the pigment finely, a method in which the medium and the object to be dispersed are separated by centrifugal force and a medium having a particle diameter of 0.3 mmφ or less (for example, see Patent Documents 13 and 14), A method is known in which a pigment composition containing a pigment, a pigment derivative, and a liquid medium is supplied and dispersed in a wet disperser equipped with a rotor pin using a media having a diameter of 0.3 mmφ or less (see, for example, Patent Document 15). It has been. However, as described above, it is very difficult to disperse the dispersion to the order of several tens of nanometers when the average particle diameter of the media is in the range of 0.3 mmφ-0.1 mmφ. In other words, there is a problem that re-aggregation tends to occur due to instability after dispersion. On the other hand, only by dispersion using a finer medium of 0.1 mmφ or less, some coarse particles contained in the pigment dispersion immediately after preliminarily kneading the pigment and liquid solvent are pulverized and dispersed to the end. However, it is mixed into the final product to cause clogging of the filter, or the ratio of the pigment contained in the product changes due to separation by filtration or the like.
JP 60-184202 A JP 60-184203 A JP-A-61-180203 JP 60-129707 A JP-A-2-144502 JP-A-2-199404 JP-A-3-53201 JP-A-5-72524 JP 60-129739 A JP 60-129707 A JP-A-5-137990 JP 11-352319 A JP 2000-171931 A JP 2002-105356 A JP 2004-81945 A

  The present invention was devised in view of the drawbacks of the prior art, and the object of the present invention is to produce a pigment without leaving a coarse pigment in the production process of a pigment dispersion using a media stirring type disperser. To produce a color filter paste with high productivity, which can be finely dispersed and dispersed efficiently to prevent re-aggregation of the pigment and thus provide a color filter with high transmittance, contrast and surface smoothness. It is to provide a method that makes it possible.

The object of the present invention is achieved by the following constitution.
That is, a method for producing a pigment dispersion having a plurality of dispersion steps in which a pigment is dispersed in a solvent using a media agitation disperser having a medium and a dispersion treatment tank, wherein the average of the media used in the first dispersion step When the particle diameter is φ (1) (mm) and the average particle diameter of the media used in the second dispersion step is φ (2) (mm), φ (1) / φ (2) is 4 or more and 40 or less , and the and phi (2) is Ri der less 0.1 mm, when the residence time of the pigment dispersion in the dispersion treatment tank and RT, the residence time in the first dispersion step RT (1) is the second This is a method for producing a pigment dispersion for a color filter, which is shorter than the residence time RT (2) in the dispersion step .

  In the media agitation type disperser used in the first dispersion step and the second dispersion step, the media and the object to be dispersed are separated by different methods, respectively, and the media used in the second dispersion step More preferably, the agitating type disperser separates the medium and the material to be dispersed by centrifugation.

When the bulk density of the medium used in the second dispersion step is 4.0 g / cm ² or more and the standard deviation of the particle size distribution of the medium is σ (mm), σ / φ (2) is 0.15. The following is preferable. Moreover, it is preferable that a pigment is an organic pigment. The viscosity of the pigment dispersion is preferably less than 50 mPa · s at a shear rate of 38 / sec at 25 ° C. of the pigment dispersion used in the second dispersion step.

  In the present invention, when a pigment composition mainly composed of a colorant, a resin, and a solvent is wet-dispersed using a media agitation type disperser, the pigment composition is dispersed through two steps with different media sizes. Highly productive pigment dispersion with excellent dispersion stability by adjusting the ratio of the average particle size of the media, the range of the average particle size of the media, and the residence time of the material to be treated in the disperser to an appropriate range It is possible to manufacture with. Then, by mixing the pigment dispersion subjected to such a dispersion treatment and the matrix resin, a color filter paste capable of producing a color filter with high transmittance, contrast and surface smoothness is produced.

  Hereinafter, the present invention will be described in more detail.

  That is, the present invention is made possible by dispersing a treatment material using a media stirring type disperser generally called a bead mill. The bead mill is a type in which a processing material flow path is provided in the gap between the stator and rotor, and dispersion processing is performed with media filled in this flow path. Dispersion processing with media filled in a cylindrical processing tank called a vessel There are many types, such as a type that performs the same, and various types of mechanisms, but the basic structure of dispersing the particles by stirring the media is common. Representative examples of the latter are as follows, but are not particularly limited to this form.

  Cylindrical vessel and treatment material inlet at one end, treatment material outlet at the other, and a separator for separating the treatment material and media and taking out only the treatment material at the treatment material outlet To do. Separators are roughly classified into screen separators, gap separators, and centrifugal separators. In recent years, separators that combine these various separators have been developed. The screen separator is a mechanism that has a stitch of a size that does not allow media to pass through and discharges only the processing material out of the processing tank, and the gap separator is a rotor that is attached to the rotating shaft and a stator that is provided in the bearing portion. It is a mechanism that creates a gap and separates the media and processing material.

  FIG. 1 shows an example of a schematic diagram of a disperser having a gap separator. The processing material is introduced into the pulverization processing chamber 7 filled with media from the inlet 4 and pulverized. Thereafter, the processing material is passed through a gap separator 2 provided with a gap equal to or smaller than the average particle diameter of the media, whereby the processing material and the media are separated, and only the processing material is taken out from the outlet 1. As a specific example of a dispersing machine having such a structure, “DYNO-MILL” manufactured by Shinmaru Enterprises Co., Ltd. can be mentioned. In addition, the centrifugal separator separates only the medium having a high specific gravity by centrifugal force by passing a mixture of the medium and the processing material through a centrifugal separation unit composed of a rotor blade or the like. FIG. 2 shows an example of a schematic diagram of a disperser having a centrifugal separator. The treatment material is introduced into the grinding chamber 15 filled with media from the inlet 14 and is ground. Thereafter, the processing material is passed through a centrifugal separator 10 called a sentry separator, and the medium and the processing material are centrifuged by a stirring blade called a rotor separator that rotates at high speed in synchronization with the rotating main shaft 11 and taken out from an outlet 8. . Specific examples of the dispersing machine having such a structure include UAM (“Ultra Apex Mill”) manufactured by Kotobuki Industries Co., Ltd. In the present invention, in the bead mill used in the first dispersion step and the second dispersion step, it is desirable to separate the media and the object to be dispersed by different methods. In the first dispersion step, an object is to selectively pulverize and disperse some coarse particles contained in the pigment dispersion immediately after the pigment and the liquid solvent are preliminarily kneaded, and φ (1) In order to make the effect of the present invention remarkable, it is preferable to circulate the object to be dispersed at a large flow rate using a relatively large medium having a thickness of 0.1 mm or more and to perform the treatment in a short time. Therefore, it is preferable to use a screen separator or a gap separator as the bead mill separator used in the first dispersion step. On the other hand, in the second dispersion step, it is necessary to use a medium of 0.1 mmφ or less. However, with a screen separator or a gap separator, it is difficult to completely separate the medium due to processing accuracy problems. There is a problem that liquid cannot be passed at a sufficient flow rate due to clogging at the part. Therefore, it is preferable to separate the media by a centrifugal separation method, and it is further preferable to use a centrifugal separation and a screen in combination. FIG. 3 shows an example of a schematic diagram of a disperser having a centrifugal screen separator. Specific examples of the dispersing machine having such a structure include “Star Mill LMZ” and “Star Mill ZRS” manufactured by Ashizawa Finetech Co., Ltd.

  A bearing is fixed to one of the vessels, and a rotating shaft for stirring the inside of the cylindrical treatment tank in the circumferential direction is provided at the bearing in the center of the tank. The joint between the bearing and the rotating shaft has a seal mechanism for preventing the processing material from flowing out through the bearing. The seal mechanism includes a gland packing, a lip seal, a single mechanical seal, a double mechanical seal, and the like, and a highly durable double mechanical seal is preferably used, but is not particularly limited thereto.

  Agitating blades having various shapes are attached to the rotating shaft at regular intervals, and rotate in the circumferential direction to give kinetic energy and shearing force to the media and the processing material. The shape of the stirring blade includes a disk type, a pin type, and a disk type with a pin. The pin type has a structure in which several pins protrude in the circumferential direction from a ring attached to the rotating shaft. There are various thicknesses, shapes, and numbers of pins, but the present invention is not limited to these.

  The disc includes a perforated type, a cam type, a wavy disc type, a disc type with a projection, a disc type with a pin, and the like, but is not particularly limited thereto. As the material of the stirring blade, ceramic, polyurethane, Teflon (registered trademark), polyethylene, or the like is used. Among them, ceramic is preferably used from the viewpoint of wear resistance, chemical resistance, heat resistance, and the like. From the viewpoint of suppressing impact and mildly dispersing, resin stirring blades are preferably used. There are vertical and horizontal types of vessels depending on the installation direction, and some of the horizontal types have a mechanism for changing the angle of the vessel depending on the dispersion state, but the invention is not limited to these. As the material inside the vessel, glass, cemented carbide, stainless steel, iron, ceramic and the like are used, and among them, ceramic is preferably used from the viewpoint of wear resistance, chemical resistance, heat resistance and the like. Zirconia and zirconia reinforced alumina, which have high wear resistance, good thermal conductivity and high cooling effect, are particularly preferably used because the media collide violently and generate high temperature, but are not particularly limited thereto.

  Regarding the entrance and exit portions, the material of the part where the collision of the media can be considered is selected in the same way as the vessel, but is not particularly limited thereto. The outside of the vessel is preferably provided with a jacket for cooling the inside of the vessel, but is not particularly limited thereto. The processing tank of the apparatus configured as described above is filled with a medium at a constant filling rate, and is stirred and dispersed together with the processing material by a stirring blade.

  In order to make the effects of the present invention remarkable, it is very important to select and use an appropriate medium, and the characteristics thereof will be described below.

  The present invention comprises two steps with different average particle diameters of the media. When the average particle diameter of the media used in the first dispersion process is φ (1) (mm), φ (1) Is preferably in the range of 0.1 to 1.0 mm, particularly preferably in the range of 0.3 to 1.0 mm. Here, the average particle diameter in the present invention refers to the equivalent circle diameter of the media, and is obtained from the average value of the longest diameter and the shortest diameter of 100 media. Specifically, the medium can be magnified and photographed with a stereomicroscope, and the particle size can be obtained from the image. The first dispersion step aims at pulverizing a coarse material to be dispersed. The larger the average particle diameter of the media, the more effectively coarse particles can be crushed. On the other hand, when the average particle diameter of the media used in the second dispersion step is φ (2) (mm), the φ (2) is preferably 0.01 mm or more and 0.10 mm or less, and 0.01 mm or more and 0.0. It is especially preferable that it is 05 mm or less. By using a medium having a smaller diameter, it is possible to disperse mildly in a short time without damaging the object to be dispersed.

  The ratio R between the average particle diameter φ (1) of the media used in the first dispersion process and the average particle diameter φ (2) of the media used in the second dispersion process may be set within an appropriate range. It is most important in the invention, and by setting the ratio appropriately, it is possible to greatly reduce the dispersion treatment time without leaving coarse particles in the pigment dispersion. As a range of the ratio, R = φ (1) / φ (2) is preferably 4 or more and 40 or less, more preferably 6 or more and 20 or less. When the ratio R is less than 4, productivity improvement by two-stage dispersion is not observed, and when the ratio R exceeds 40, the dispersion to be dispersed after the first process is large, so that the second process is pulverized. The problem that it cannot be performed and remains as coarse particles arises.

As the material of the media, beads such as glass, cemented carbide, steel balls, and ceramics are used. Among them, ceramic is preferably used from the viewpoint of wear resistance, chemical resistance, heat resistance, etc., and more preferably wear resistance. Zirconia and zirconia reinforced alumina having high heat conductivity and good cooling effect are used, but not particularly limited thereto. However, the bulk density of the media used in the second dispersion step is preferably 4.0 g / cm ² or more. The higher the media, the greater the impact force and the shorter the dispersion treatment time. The term “bulk density” as used herein refers to the density obtained by considering the pores present in the media material as part of the material, but the term is not uniform depending on the field. Sometimes called density. Here, the density of the media is obtained by Archimedes method with about 20 g of media placed in a container. Also, when separating a minute medium having φ (2) of 0.10 mm or less by a centrifugal separation method, it is preferable that the medium has a higher bulk density because stable separation is possible. Further, as the distribution of the average particle size of the media used in the second dispersion step, the standard deviation of the particle size distribution of the media used in the second dispersion step is set to σ ( mm), σ / φ (2) is preferably 0.15 or less, and more preferably σ / φ (2) is 0.10 or less. By using a medium with a sharp particle size distribution when the average particle diameter φ (2) of the medium is 0.10 mm or less, the particle size distribution of the dispersed material becomes sharper, and the transparency and stability are good. A dispersion can be obtained. Examples of a method for sharpening the particle size distribution of the media include a method of classifying using a screen (such as a sieve or a mesh).

  The filling rate of the media is preferably 50 to 90 (%), more preferably 70 to 87 (%). The filling rate here refers to the ratio of the volume including the space between the media of the closely packed media to the space volume in the pulverization chamber of the disperser. When the media filling rate is 50 (%) or less, the influence of the short path becomes remarkable, the residence time is required for a long time, and the dispersion efficiency is deteriorated. If the residence time is further increased, the part or all of the processing material is excessively dispersed, and part or all of the processing material is re-agglomerated, resulting in a problem that the quality of the whole processing material is deteriorated. When the filling rate of the media is 90 (%) or more, the load on the rotating shaft at the time of startup increases, causing damage to the device. For this reason, it is impossible to increase the packing efficiency more than necessary to increase the dispersion efficiency.

The dispersion performed in the present invention adopts a form in which the processing material is circulated in multiple stages (hereinafter referred to as circulation dispersion), and the calculation of the treatment time in circulation dispersion defines the residence time RT (minutes). Accordingly, the processing efficiency can be compared regardless of the amount of the processing tank and the processing material. The calculation of the residence time is expressed by the following equation when the volume of the processing material = v (cm ³ ), the effective volume of the processing tank = V (cm ³ ), and the operation time = t (min).

Residence time (RT) = V / v × t
By making the residence time RT (1) in the first dispersion step shorter than the residence time RT (2) in the second dispersion step, it is possible to obtain a highly productive and stable pigment dispersion. Further, by setting each residence time to an appropriate value, it is possible to selectively improve the storage stability of the pigment dispersion and the properties such as transmittance and contrast when formed into a coating film. The range satisfies the relationship of RT (1) <RT (2), and the range of RT (1) is preferably 2 minutes or longer and 20 minutes or shorter, more preferably 2 minutes or longer and 10 minutes or shorter, and RT (2 ) Is preferably from 2 minutes to 60 minutes, and more preferably from 2 minutes to 30 minutes. In the first dispersion step, a medium having a large diameter is used for the purpose of pulverizing the coarse pigment as described above. Therefore, in order to minimize the energy given to the dispersion and suppress the surface activity of the particles, the residence time RT (1 ) Is preferably shorter as long as coarse particles can be sufficiently pulverized. On the other hand, also in the second dispersion step, from the viewpoint of productivity and dispersion stability, it is preferable that the residence time RT (2) is as short as possible in a range where the dispersion can be made fine.

  A factor that greatly contributes to the dispersion of the treated material is the rotational speed of a rotor such as a stirring blade. The rotational speed in the present invention is preferably 5 m / s to 15 m / s, and more preferably 7 m / s to 14 m / s. The following is preferred. When the rotational speed of the rotor is 5 m / s or less, it is not possible to sufficiently pulverize and disperse the object to be dispersed, or in a disperser using a centrifugal separator, media bias or media due to a decrease in centrifugal separation ability Problems such as spillage. Further, when the rotor rotational speed is 15 m / s or more, there is a problem that excessive energy is applied to the object to be dispersed and the dispersion tends to be excessively dispersed.

  In the present invention, the pigment dispersion supplied to the wet disperser is mainly composed of a pigment and a solvent, and optionally mixed with additives such as a resin, a pigment derivative, a dispersant, and a surfactant. Use things.

  In the second dispersion step of the present invention, the viscosity of the pigment dispersion is important for stable dispersion. If the viscosity of the pigment dispersion is too high, the minute media cannot be sufficiently centrifuged, causing the media to be biased, resulting in problems such as blockage at the separator and outflow of the media. Accordingly, the viscosity of the pigment dispersion used in the second dispersion step of the present invention is preferably less than 50 mPa · s at a shear rate of 38 / sec at 25 ° C., and more preferably at a shear rate of 38 at 25 ° C. The viscosity at / second is preferably less than 30 mPa · s.

  As the pigment used in the pigment dispersion, either an organic pigment or an inorganic pigment can be preferably used, but it is desirable to use an organic pigment in terms of chromaticity characteristics. Of the pigments, those having high transparency and excellent light resistance, heat resistance, and chemical resistance are particularly preferable. When specific examples of typical pigments are indicated by color index (CI) numbers, the following are preferably used, but they are not limited to these.

  Examples of red pigments include Pigment Red (hereinafter abbreviated as PR) 9, PR48, PR97, PR122, PR123, PR144, PR149, PR166, PR168, PR177, PR179, PR180, PR192, PR209, PR215, PR216, PR217, PR220. , PR223, PR224, PR226, PR227, PR228, PR240, PR254, etc. are used.

  Examples of orange pigments include pigment orange (hereinafter abbreviated as PO) 13, PO36, PO38, PO43, PO51, PO55, PO59, PO61, PO64, PO65, PO71, and the like.

  Examples of yellow pigments include pigment yellow (hereinafter abbreviated as PY) PY12, PY13, PY17, PY20, PY24, PY83, PY86, PY93, PY95, PY109, PY110, PY117, PY125, PY129, PY137, PY138, PY139, PY147. , PY148, PY150, PY153, PY154, PY166, PY168, PY185, etc. are used.

  Examples of purple pigments include pigment violet (hereinafter abbreviated as PV) 19, PV23, PV29, PV30, PV32, PV37, PV40, and PV50.

  Examples of blue pigments include pigment blue (hereinafter abbreviated as PB) 15, PB15: 3, PB15: 4, PB15: 6, PB22, PB60, and PB64.

  Examples of green pigments include pigment green (hereinafter abbreviated as PG) 7, PG10, and PG36. Examples of black pigments include pigment black 7, titanium oxide, titanium oxynitride, and tetraoxide. Metal oxide powder such as iron, metal sulfide powder, metal powder and the like are used.

  These pigments may be subjected to surface treatment such as rosin treatment, acidic group treatment, basic treatment, etc., if necessary, and a pigment derivative may be added as a dispersant.

  The solvent used in the pigment dispersion is not particularly limited, and water and an organic solvent can be used in accordance with the dispersion stability of the pigment to be dispersed and the solubility of the resin to be added. The organic solvent is not particularly limited, and a (poly) alkylene glycol ether solvent, an aliphatic ester, an aliphatic alcohol, a ketone, an amide polar solvent, or a lactone polar solvent is used. These can be used alone or in combination of two or more. Mixing with other solvents is also preferably used.

  The resin used in the pigment dispersion is not particularly limited, and is photosensitive or non-photosensitive such as epoxy resin, acrylic resin, urethane resin, polyester resin, polyimide resin, polyolefin resin, gelatin, and the like. Materials are preferably used.

  The dispersant added to the pigment dispersion is not particularly limited, and a polymer such as polyester, polyalkylamine, polyallylamine, polyimine, polyamide, polyurethane, polyacrylate, polyimide, polyamideimide, or the like. Various things such as a copolymer can be used alone or in combination.

  The color filter paste used in the present invention may be either a colored paste or a black paste, and is obtained by adding a resin, a solvent, or the like to the pigment dispersion and diluting it. Furthermore, various additives such as an ultraviolet absorber, a dispersant, and a surfactant may be added. For the photosensitive paste, a photopolymerization initiator, a polymerizable monomer, and the like are further added.

  The resin used when making the paste is the same as that used for the pigment dispersion, and is not particularly limited. Epoxy resin, acrylic resin, urethane resin, polyester resin, polyimide resin, polyolefin resin, Photosensitive or non-photosensitive materials such as gelatin are preferably used. Photosensitive resins include photodegradable resins, photocrosslinkable resins, and photopolymerizable resins. In particular, monomers, oligomers, or polymers having an ethylenically unsaturated bond and initiators that generate radicals by ultraviolet rays are used. A photosensitive composition containing, a photosensitive polyamic acid composition, and the like are preferably used. As the non-photosensitive resin, those that can be developed with the above-mentioned various polymers are preferably used, but they are heat resistant to withstand the heat applied in the transparent conductive film forming process and the liquid crystal display manufacturing process. In addition, since a resin having resistance to an organic solvent used in a manufacturing process of a liquid crystal display device is preferable, a polyimide resin and an acrylic resin are particularly preferably used.

  As the polyimide resin used for the paste, a resin obtained by imidizing polyamic acid, which is a polyimide precursor, with heating or an appropriate catalyst is preferably used. A polyamic acid is obtained by reacting a tetracarboxylic dianhydride with a secondary amine. The polyimide resin may contain bonds other than imide bonds such as amide bonds, sulfone bonds, ether bonds, and carbonyl bonds in addition to imide bonds.

    As the tetracarboxylic dianhydride, for example, an aliphatic or alicyclic one can be used. Moreover, when an aromatic material is used, a polyimide precursor composition that can be converted into polyimide having good heat resistance can be obtained. Moreover, when a fluorine-type thing is used, the polyimide precursor composition which can be converted into a polyimide with favorable transparency in a short wavelength region can be obtained. In addition, this invention is not limited to these, The tetracarboxylic dianhydride is used 1 type (s) or 2 or more types.

  As the diamine, for example, an aliphatic or alicyclic one can be used. Moreover, when an aromatic material is used, a polyimide precursor composition that can be converted into polyimide having good heat resistance can be obtained. Moreover, when a fluorine-type thing is used, the polyimide precursor composition which can be converted into a polyimide with favorable transparency in a short wavelength region can be obtained.

  Moreover, when siloxane diamine is used, adhesiveness with an inorganic substrate can be made favorable. Siloxane diamine is usually used in an amount of 1 to 20 mol% in the total diamine. If the amount of siloxane diamine is too small, the effect of improving the adhesiveness is not exhibited, and if it is too large, the heat resistance is lowered. The present invention is not limited to these, and one or more diamines are used.

  The synthesis of polyamic acid is generally performed by reacting diamine and tetracarboxylic dianhydride in a polar organic solvent. At this time, the polymerization degree of the polyamic acid obtained can be controlled by the mixing ratio of diamine and tetracarboxylic dianhydride. In addition, there are various methods for obtaining polyamic acid, such as reacting tetracarboxylic acid dichloride and diamine in a polar organic solvent and then removing hydrochloric acid and the solvent to obtain polyamic acid. However, the present invention can be applied to a polyamic acid regardless of the synthesis method.

  Next, the number of repeating structural units of the polyamic acid will be described. Since the mechanical properties of the polyimide film are better as the molecular weight is larger, it is desirable that the molecular weight of the polyamic acid that is the polyimide precursor is also larger. On the other hand, when patterning a polyamic acid film by wet etching, if the molecular weight of the polyamic acid is too large, there is a problem that the time required for development becomes too long. Therefore, the preferred range of the number of repeating structural units is 15 to 10,000, more preferably 18 to 400, and still more preferably 20 to 100. In addition, since the molecular weight of polyamic acid generally varies, the preferable range of the number of repeating structural units here is 50 mol% or more, preferably 70 mol% or more of the total polyamic acid, Preferably, it means that 90 mol% or more is contained.

  Although it does not specifically limit as acrylic resin used for a paste, The copolymer of unsaturated carboxylic acid and the copolymer of unsaturated carboxylic acid and an ethylenically unsaturated compound can be used preferably.

  Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, and vinyl acetic acid. Examples of the copolymerizable ethylenically unsaturated compound include unsaturated carboxylic acid alkyls. Examples thereof include, but are not limited to, esters, aromatic vinyl compounds, carboxylic acid vinyl esters, vinyl cyanide compounds, aliphatic conjugated dienes, macromonomers each having an acryloyl group or a methacryloyl group at the terminal.

  The photopolymerization initiator used for the paste is not particularly limited, and is a benzophenone compound, acetophenone compound, oxanthone compound, imidazole compound, benzothiazole compound, benzoxazole compound, triazine compound, phosphorus compound or Known materials such as an inorganic photopolymerization initiator such as titanate can be used. Further, it is preferable to add a sensitizing aid such as an aromatic or aliphatic tertiary amine because the sensitivity can be further improved. Moreover, these photoinitiators can also be used in combination of 2 or more types.

  The addition amount of the photopolymerization initiator is not particularly limited, but is preferably 2 to 30% by weight, more preferably 5 to 25% by weight with respect to the total solid content of the colorant composition.

  As the polymerizable monomer used in the paste, a polyfunctional or monofunctional acrylic monomer or oligomer can be used. Resist sensitivity and processability characteristics can be controlled by selecting and combining polyfunctional and monofunctional monomers and oligomers. In particular, in order to increase sensitivity, a compound having 3 or more, more preferably 5 or more functional groups is desirable.

  The solvent used for the paste is not particularly limited, as is the case with the pigment dispersion, and water and organic solvents can be used. The organic solvent is not particularly limited, and (poly) alkylene glycol ether solvents, or aliphatic esters, aliphatic alcohols, ketones, amide polar solvents, and lactone polar solvents may be used. These can be used alone or in combination of two or more. Mixing with other solvents is also preferably used.

  However, when the colorant composition of the present invention is applied to a substrate by a die coating method, the boiling point is relatively high from the viewpoint of uniformity of film thickness and prevention of the formation of pigment aggregates in the discharge slit portion. It is preferable to use a solvent. On the other hand, when the boiling point is too high, the drying property is deteriorated. Specifically, although not particularly limited, it is preferable to use a solvent having a boiling point in the range of 158 ° C. or more and 214 ° C. or less.

  In the paste of the present invention, the resin component (total of polymer, monomer or oligomer and polymer dispersant) and the colorant containing at least the pigment are usually 20% by weight of the resin component with respect to the solid content of the entire paste. It is used by mixing in the range of 95% by weight, preferably 40% by weight to 90% by weight. If the amount of the resin component is too small, the adhesion of the colored coating to the substrate becomes poor. Conversely, if the amount of the resin component is too large, the colorant component is reduced and the degree of coloration becomes a problem.

  In order to improve the adhesion of the paste to the substrate, it is also preferable to add a silane coupling agent to the paste of the present invention.

  Furthermore, a surfactant can be added to the paste of the present invention for the purpose of improving the paste applicability and the uniformity of the surface of the colored film, or for improving the dispersibility of the pigment. The amount of the surfactant added is preferably 0.001 to 10% by weight, more preferably 0.01 to 1% by weight, based on the pigment. If the amount added is too small, there will be no effect of improving the coating property, the uniformity of the colored film surface, or the dispersibility of the pigment. If the amount is too large, the coating property will be poor or the pigment will aggregate.

  Specific examples of such surfactants include anionic surfactants such as ammonium lauryl sulfate and polyoxyethylene alkyl ether sulfate triethanolamine, cationic surfactants such as stearylamine acetate and lauryltrimethylammonium chloride, lauryldimethylamine oxide. Amphoteric surfactants such as lauryl carboxymethyl hydroxyethyl imidazolium betaine, and nonionic surfactants such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, and sorbitan monostearate are preferably used. Such surfactants can be used alone or in combination. Such a surfactant can be added at any point during or before or after the pigment dispersion step. However, care should be taken because the dispersibility of the pigment may change depending on the point of addition.

  The color filter produced with the paste obtained by the production method of the present invention will be described. A color filter consists of a plurality of colored layers composed of three primary colors arranged on a transparent substrate, and the color filter is composed of a large number of picture elements, each pixel being covered by each colored layer consisting of the three primary colors. ing. The transparent substrate used for the color filter is not particularly limited, and includes inorganic glass such as quartz glass, borosilicate glass, aluminosilicate glass, soda lime glass coated with silica on the surface, organic plastic film or sheet. Etc. are preferably used.

  The three primary colors referred to here are red (R), green (G), and blue (B) when the color display is performed by the additive color mixing method, and the color display is performed by the subtractive color mixing method. Three primary colors of cyan (C), magenta (M), and yellow (Y) are selected. In general, an element including these three primary colors can be used as a unit as a color display picture element.

  As a method of forming the colored layer, patterning is performed after applying or drying the colored paste directly or on a substrate on which a black matrix has been formed in advance.

  As a method for applying the paste, a spin coating method, a roll coating method, a bar coating method, a die coating method, or the like can be used, but it is not particularly limited to these methods. After a paste is applied to the substrate to form a wet film, heat drying (semi-cure) is performed using an oven or a hot plate. Semi-cure conditions vary depending on the resin, solvent, and paste coating amount used, but it is usually preferable to heat at 60 to 200 ° C. for 1 to 60 minutes.

  When the resin paste is a non-photosensitive resin, the paste coating obtained in this way is used after a positive photoresist coating is formed thereon, and when the resin is a photosensitive resin. Is exposed or developed as it is or after an oxygen blocking film is formed. If necessary, the positive type photoresist or the oxygen blocking film is removed, and then heat-dried (cured) again. The curing conditions vary depending on the resin, but when a polyimide resin is obtained from a polyimide precursor, it is generally heated at 200 to 300 ° C. for 1 to 60 minutes.

  The post-cure film thickness of the colored layer to be applied is determined by the required color characteristics and the colorant / matrix resin ratio of the colored paste. Usually, the colorant / matrix resin ratio is in the range of 5/95 to 70/30 by weight, but preferably in the range of 10/90 to 60/40. When the colorant ratio is less than 5, the film thickness that needs to be applied in order to obtain sufficient color purity becomes too thick, so that the level difference between the pixels becomes large, causing problems such as poor alignment of the liquid crystal. If the colorant ratio exceeds 70, the matrix resin is insufficient, and there are problems such as poor pixel adhesion. When the colorant / matrix resin ratio is set within this preferred range, the post-cure film thickness that needs to be applied to obtain the desired color characteristics is 0.2 to 4.0 μm. If it is thinner than 0.2 μm, sufficient color purity cannot be obtained, and if it is thicker than 4.0 μm, the light transmittance is insufficient.

  The black matrix is usually provided with openings of (20 to 200) μm × (20 to 300) μm, and a plurality of colored layers of three primary colors are arranged so as to cover at least the openings. The pattern arrangement of the three primary colors can be suitably used according to the purpose such as mosaic type, triangle type, stripe type, and four pixel arrangement type.

  The light shielding property of the black matrix is expressed by an OD value (common logarithm of the reciprocal of the transmittance), and is preferably 2.5 or more, more preferably 3 in order to improve the display quality of the liquid crystal display device. 0.0 or more. The upper limit of the OD value is determined by the film thickness of the black matrix.

  The film thickness of the black matrix is preferably 0.5 to 1.5 μm, more preferably 0.8 to 1.2 μm. When the film thickness is thinner than 0.5 μm, the light shielding property is insufficient, which is not preferable. On the other hand, when the film thickness is thicker than 1.5 μm, the light-shielding property can be secured, but the flatness of the color filter tends to be sacrificed and a step is likely to occur. If a surface level difference occurs, even if a transparent conductive film or liquid crystal alignment film is formed on the color filter, the level difference is hardly reduced, and the alignment process by rubbing the liquid crystal alignment film becomes non-uniform, resulting in a display quality of the liquid crystal display device. Decreases. In order to reduce the surface level difference, it is effective to provide a transparent protective film on the colored layer.

  Further, the reflectance of the black matrix is a reflection-corrected reflection in the visible region of 400 to 700 nm in order to reduce the influence of the reflected light at the boundary surface between the pixel and the light shielding region and improve the display quality of the liquid crystal display device. The rate (Y value) is preferably 2% or less, more preferably 1% or less. When the reflectance is 2% or more, the display contrast is lowered due to the surface reflected light.

Next, a liquid crystal display device produced using the present invention will be described. The color filter is formed by facing the color filter and the transparent electrode substrate. If necessary, the color filter may be provided with a transparent protective film on the colored layer. A transparent electrode such as an ITO film is formed on the color filter.

  Hereinafter, although the manufacturing method of this invention is demonstrated in detail using an Example and a comparative example, this invention is not limited to a following example.

The bead mill used in Examples and Comparative Examples is as follows.
・ Media stirring type disperser (1) Dino mill KDL
Made by Shinmaru Enterprises, Separator: Gap method (2) Ultra Apex Mill (UAM)
Manufactured by Kotobuki Industry Co., Ltd., separator: Centrifugal separation method (3) Starmill ZRS
Ashizawa Finetech Co., Ltd. separator: Centrifugation + screen system Further, the bulk density of the media used in the examples and the ratio of the median particle size and the standard deviation of the media particle size distribution σ / φ (2) Table 1 shows.

  For zirconia beads having media diameters of 0.10, 0.30, 1.00, 2.00, and 3.00 mm, beads “Traceram ball beads” manufactured by Toray Industries, Inc. are used, and the media diameter is 0.03 mm. For zirconia beads, beads “YTZ ball” manufactured by Nikkato Co., Ltd. were used, and for zirconia beads having a media diameter of 0.05 mm, those obtained by the following production method were used.

A. Method for producing 0.05 mm zirconia beads A mixture of partially stabilized zirconia powder containing 2.7 mol% of yttria and water (granulating agent) was mixed for 2 hours in an attritor mill using zirconia beads, and 20 kg, A slurry having a partially stabilized zirconia powder content of 30% by weight was prepared. Subsequently, this slurry was sprayed and dried using a disk-type spray dryer to obtain molded spheres. At this time, the rotational speed of the disk was 8,000 rpm, the hot air temperature was 240 ° C., and the exhaust air temperature was 100 ° C. Next, the obtained molded spheres were classified using a sieve having an opening degree of 0.045 mm and 0.125 mm to obtain molded spheres having an average particle size of 0.08 mm. Then, the molded sphere obtained by classification was sintered in air at 1400 degrees for 2 hours to obtain a zirconia sphere. The zirconia spheres were classified using a standard sieve having an opening of 63 μm and an opening of 32 μm. The average particle diameter was 0.046 mm, the longest diameter was 0.063 mm, the shortest diameter was 0.033 mm, and the standard deviation was 0.0077. Zirconia beads A-2-1 were obtained.
The zirconia beads A-2-1 are classified using a standard sieve having an aperture of 63 μm and an aperture of 38 μm. The average particle size: 0.052 mm, the longest diameter: 0.063 mm, the shortest diameter: 0.038 mm, standard Deviation: 0.0066 zirconia beads A-2-2 were obtained.
The zirconia beads A-2-1 are classified using a standard sieve having an aperture of 53 μm and an aperture of 38 μm, and the average particle size: 0.051 mm, longest diameter: 0.053 mm, shortest diameter: 0.038 mm, standard Deviation: 0.0043 zirconia beads A-2-3 were obtained.
In addition, the polyamic acid B-1 and the pigment dispersion G-1 used in the examples are manufactured by the following method.

B. Production method of polyamic acid B-1, 4,4′-diaminophenyl ether; 330.6 g (0.75 mol), 3,3′-diaminodiphenyl sulfone; 49.6 g (0.20 mol), bis (3-aminopropyl) Tetramethyldisiloxane; 12.4 g (0.005 mol) was charged with 2730 g of γ-butyrolactone, and 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride; 161.0 g (0.49 mol) and pyromerit 106.8 g (0.49 mol) of acid dianhydride was added and reacted at 60 ° C. for 5 hours. 1.96 g (0.02 mol) of maleic anhydride was added and further reacted at 60 ° C. for 1 hour to obtain a polyamic acid (referred to as B-1) solution.

C. Production Method of Pigment Dispersion G-1 Green Pigment (Pigment Green 36); 3.3 wt%, Yellow Pigment (Pigment Yellow 138); 3.0 wt%, Polyamic Acid B-1; 4.7 wt%, γ- Butyrolactone: 89.0% by weight was charged in a tank and stirred for 1 hour with a homomixer (manufactured by Tokushu Kika) to obtain pigment dispersion G-1. The viscosity of this pigment dispersion G-1 was measured using an RC500 viscometer (manufactured by Toki Sangyo) equipped with a cone plate having a tip angle of 1 degree 34 seconds. The viscosity at / second was 2.90 mPa · s.
<Example 1>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 0.30 mm, and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. Then, the dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads (A-2-3) having a particle diameter φ (2); 0.05 mm, and a rotational speed of 11 m. Dispersion was carried out so that the residence time RT (2) was 17 minutes at / s. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter having a pore size of 2 μm (PF020 manufactured by ADVANTEC), spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Example 2>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 0.30 mm, and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. Then, the dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads (A-2-2) having a particle diameter φ (2); 0.05 mm, and a rotational speed of 11 m. Dispersion was carried out so that the residence time RT (2) was 17 minutes at / s. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Example 3>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 0.30 mm, and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. Then, the pigment dispersion after dispersion is used in a bead mill (UAM) equipped with a centrifugal separator using particle diameter φ (2); broad 0.05 mm zirconia beads (A-2-1) having a particle size distribution. The dispersion was performed so that the residence time RT (2) was 17 minutes at a rotation speed of 11 m / s. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Example 4>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 1.00 mm, and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. Then, the dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads (A-2-3) having a particle diameter φ (2); 0.05 mm, and a rotational speed of 11 m. Dispersion was carried out so that the residence time RT (2) was 17 minutes at / s. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Example 5>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 2.00 mm and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. Then, the dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads (A-2-3) having a particle diameter φ (2); 0.05 mm, and a rotational speed of 11 m. Dispersion was carried out so that the residence time RT (2) was 17 minutes at / s. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Example 6>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 0.30 mm, and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. The pigment dispersion after dispersion is supplied to a bead mill (ZRS) equipped with a centrifugal separator using zirconia beads (A-2-3) having a particle diameter φ (2); 0.05 mm, and a rotational speed of 11 m. Dispersion was performed such that the residence time RT (2) was 22 minutes at / s. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Example 7>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 0.30 mm, and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. The dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads having a particle diameter φ (2); 0.03 mm, and a residence time RT ( Dispersion was performed so that 2) was 12 minutes. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Example 8>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 1.00 mm, and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. The dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads having a particle diameter φ (2); 0.03 mm, and a residence time RT ( Dispersion was performed so that 2) was 12 minutes. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Comparative Example 1>
Pigment dispersion G-1 is supplied to a bead mill (Dynomill) equipped with a gap separator using zirconia beads having a particle size of 0.30 mm, and dispersed so that the residence time RT is 70 minutes at a rotational speed of 11 m / s. It was. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Comparative example 2>
The pigment dispersion G-1 is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads having a particle size of 0.10 mm, and dispersed at a rotational speed of 11 m / s so that the residence time RT is 25 minutes. went. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Comparative Example 3>
The pigment dispersion G-1 is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads (A-2-3) having a particle diameter of 0.05 mm, and the residence time RT is 11 m / s. Dispersion was performed to be 20 minutes. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Comparative example 4>
The pigment dispersion G-1 is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads having a particle diameter of φ (1); 0.10 mm, and a residence time RT (1) at a rotational speed of 11 m / s. The dispersion was carried out so as to be 3 minutes. Then, the dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads (A-2-3) having a particle diameter φ (2); 0.05 mm, and a rotational speed of 11 m. Dispersion was carried out so that the residence time RT (2) was 17 minutes at / s. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Comparative Example 5>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter of φ (1); 3.00 mm and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. Then, the dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads (A-2-3) having a particle diameter φ (2); 0.05 mm, and a rotational speed of 11 m. Dispersion was carried out so that the residence time RT (2) was 17 minutes at / s. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Comparative Example 6>
The pigment dispersion G-1 is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads having a particle diameter of φ (1); 0.10 mm, and a residence time RT (1) at a rotational speed of 11 m / s. The dispersion was carried out so as to be 3 minutes. The dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads having a particle diameter φ (2); 0.03 mm, and a residence time RT ( Dispersion was performed so that 2) was 12 minutes. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.
<Comparative Example 7>
The pigment dispersion G-1 is supplied to a bead mill (Dynomill) using a zirconia bead having a particle diameter φ (1); 2.00 mm and having a gap separator, and the residence time RT (1) is 11 m / s. Dispersion was performed to be 3 minutes. The dispersed pigment dispersion is supplied to a bead mill (UAM) equipped with a centrifugal separator using zirconia beads having a particle diameter φ (2); 0.03 mm, and a residence time RT ( Dispersion was carried out so that 2) was 17 minutes. This dispersion was diluted with a polyimide precursor B-1 diluent to prepare a green colored paste. The green colored paste was filtered through a polyfluorone filter (PF020 manufactured by ADVANTEC) having a pore size of 2 μm, spin-coated on an alkali-free glass substrate, and then heat-treated to obtain a polyimide colored film.

  Table 2 shows the dispersion conditions in Examples 1 to 8 and Comparative Examples 1 to 7.

  The obtained colored coating film was evaluated for chromaticity, contrast, and surface roughness. Table 3 shows the evaluation result of the colored film together with the filtration result of the obtained colored paste. The values shown in Table 3 are obtained by the following method, and the value is y = 0.594 in the C light source of the colored film.

(1) Chromaticity Using a microspectrophotometer MCPD-2000 (manufactured by Otsuka Electronics Co., Ltd.), the transmittance Y, x value, and y value with a C light source were measured.

(2) Contrast A substrate sample was sandwiched between polarizing plates, and a contrast was measured from the ratio of the parallel Nicol luminance and the crossed Nicol luminance using a color luminance meter BM-5A (manufactured by Topcon).

(3) Surface roughness The surface roughness was measured using a surface shape measuring device Surfcom 1500A (Tokyo Seimitsu).

  The colored pastes obtained in the examples have no filtration clogging, and the coating films using the colored pastes have no chromaticity deviation, good transmittance and surface compared with the coating films obtained in the comparative examples. Roughness and contrast were shown.

It is the schematic which shows an example of the disperser which has a gap separator used for the manufacturing method of the pigment dispersion liquid of this invention. It is the schematic which shows an example of the disperser which has the centrifugal separator used for the manufacturing method of the pigment dispersion liquid of this invention. It is the schematic which shows an example of the disperser which has the centrifugal separation used for the manufacturing method of the pigment dispersion liquid of this invention, and a screen separator.

Explanation of symbols

1, 8, 19 Treatment material outlet 2 Gap separators 3, 12, 20 Stirring blades 4, 14 Treatment material inlets 5, 9, 16 Mechanical seals 6, 11, 17 Rotating spindles 7, 15, 21 Crushing treatment chamber 10 Sentry Separator 13 Backflow valve 18 Centrifugal screen separator

Claims (8)

A method for producing a pigment dispersion having a plurality of dispersion steps in which a pigment is dispersed in a solvent using a media stirring type disperser having a media and a dispersion treatment tank, wherein the average particle size of the media used in the first dispersion step Is φ (1) (mm) and the average particle diameter of the media used in the second dispersion step is φ (2) (mm), φ (1) / φ (2) is 4 or more and 40 or less. and phi (2) is Ri der 0.1 (mm) or less, when the residence time of the pigment dispersion in the dispersion treatment tank and RT, the residence time in the first dispersion step RT (1) comprises first A method for producing a pigment dispersion for a color filter, which is shorter than a residence time RT (2) in the dispersion step (2) . The method for producing a pigment dispersion for a color filter according to claim 1, wherein the media stirring type disperser used in the second dispersion step separates the medium and the pigment dispersion by centrifugation. The method for producing a pigment dispersion for a color filter according to claim 1 or 2, wherein the bulk density of the medium used in the second dispersion step is 4.0 g / cm ² or more. When the standard deviation of the particle size distribution of media used and the sigma (mm) in the second dispersion step, any claim 1-3, characterized in that sigma / phi (2) is 0.15 or less A method for producing a pigment dispersion for a color filter according to claim 1. The method for producing a pigment dispersion for a color filter according to any one of claims 1 to 4 , wherein the pigment is an organic pigment. The pigment dispersion for a color filter according to any one of claims 1 to 5 , wherein the pigment dispersion used in the second dispersion step has a viscosity at a shear rate of 38 / sec at 25 ° C of less than 50 mPa · s. Liquid manufacturing method. Claim 1-6 or characterized by containing a color filter pigment dispersion and the resin obtained by the method according to the color filter paste. The color filter paste according to claim 7 is used for the colored layer or the light shielding layer in a color filter having a pixel composed of a colored layer and a light shielding layer provided in a desired pattern for each color with an arbitrary number of colors. A color filter characterized by

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