JP2011033796A - Red pigment dispersion liquid for color filter, red photosensitive resin composition for color filter, color filter and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pigment dispersion liquid which is excellent in pigment dispersibility and is capable of forming a color filter of high contrast, and to provide a photosensitive resin composition. <P>SOLUTION: The red pigment dispersion liquid for the color filter includes: a red pigment; a yellow or orange pigment for which the light transmittance of a specified test film is ≥90% in the wavelength region of 560 nm-640 nm; a pigment dispersant; and a solvent, wherein the average dispersion particle size of dispersed pigment particles is 15-80 nm. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is used for a color filter red pigment dispersion used for forming a colored layer such as a pixel, a color filter red photosensitive resin composition, and a liquid crystal display device using the resin composition. Related to the color filter.

In recent years, with the rapid spread of household televisions, it has become an important issue for liquid crystal display devices to increase contrast and brightness so that a clear black display and bright images can be obtained in any environment.
In general, as shown in FIG. 2A, the color liquid crystal display device (101) is provided with a gap portion 3 of about 1 to 10 μm with the color filter 1 and an electrode substrate 2 such as a TFT substrate facing each other. 3 is filled with a liquid crystal compound L, and the periphery thereof is sealed with a sealing material 4. The color filter 1 includes a light shielding layer (black matrix layer) 6 formed in a predetermined pattern on the transparent substrate 5 to shield the boundary between the colored layers, and a plurality of colors (usually normal) to form each pixel. , Red (R), green (G), and blue (B) are arranged in a predetermined order, a protective layer 8 and a transparent electrode film 9 are arranged in this order from the side close to the transparent substrate. It has a laminated structure. An alignment film 10 is provided on the inner surface side of the color filter 1 and the electrode substrate 2 facing the color filter 1. Furthermore, a spacer is provided in the gap portion 3 in order to maintain a constant and uniform cell gap between the color filter 1 and the electrode substrate 2. As the spacer, pearls 11 having a constant particle diameter are dispersed, or columnar spacers 12 having a height corresponding to the cell gap as shown in FIG. 6 is formed in a region overlapping with the position where 6 is formed. A color image can be obtained by controlling the light transmittance of each colored layer colored in each color or the liquid crystal layer behind the color filter.

  At present, it is a mainstream to produce a colored layer of a color filter by a method called a pigment dispersion method using a pigment having excellent light resistance and heat resistance as a colorant. However, in general, a color filter in which a pigment is dispersed has a problem that the degree of polarization controlled by the liquid crystal is disturbed due to light scattering by the pigment. That is, since light leaks when light must be blocked (OFF state) or transmitted light attenuates when light must be transmitted (ON state), display devices in the ON state and the OFF state There is a problem that the upper luminance ratio (contrast ratio) is low.

  In order to realize high luminance and high contrast of the color filter, it has been studied so far to make the pigment contained in the colored layer fine (for example, Patent Document 1). In Patent Document 1, in a pigment composed of an aggregate of primary particles, the number ratio of primary particles having a particle size of 0.1 μm or less is 95% or more of all particles, and the number ratio of primary particles having a particle size of more than 0.1 μm. A refined pigment characterized by being less than 5% of the total number of particles is disclosed. However, the pigment particle size disclosed herein is the particle size of the produced pigment itself. Pigments whose primary particles have been made finer generally tend to aggregate, and even if finer pigments are used, the pigment particles actually dispersed in the resin composition may exist as coarse particles or fine particles. In general, it is difficult to obtain a stable coloring composition, for example, when the conversion to too much proceeds, a huge lump of pigment solid is formed. Also in Patent Document 1, in the coloring composition obtained by dispersing the above-mentioned fine pigment in a dispersion medium, the average particle diameter of the dispersed pigment particles is preferably 0.2 μm or less. Has been. In the conventional dispersed particle size distribution of the dispersed pigment as disclosed in Patent Document 1, light leaks to the OFF state, which is insufficient to improve the contrast.

  On the other hand, in Patent Document 2, a yellow pigment is mixed with a specific red pigment for the purpose of obtaining a color filter with high sensitivity, high transmittance, contrast, and high resolution and constant excellent chromaticity. Are listed. However, Patent Document 2 only describes that the contrast is high due to the miniaturization of the pigment.

JP 2003-89756 A JP 2000-89025 A

  The present invention has been accomplished in view of the above circumstances, and its object is to provide a red pigment dispersion for a color filter capable of forming a color filter with high contrast, a red photosensitive resin composition for a color filter, and the resin. An object of the present invention is to provide a color filter having a high contrast and a display device using the composition.

  As a result of intensive studies in view of the above problems, the present inventors have performed toning using a pigment capable of increasing parallel luminance without increasing orthogonal luminance in a wavelength region where the red pigment transmits, and dispersing When the colored layer of the color filter is formed using the red photosensitive resin composition in which the dispersed particle size of the pigment is controlled, the light leaks when the light has to be blocked (OFF state) while suppressing the light. It has been found that the transmitted light can be raised when it has to pass through (ON state) and the contrast is dramatically improved, and the present invention has been completed.

That is, the present invention is a color filter comprising a red pigment, a yellow or orange pigment having a light transmittance of 90% or more in the wavelength range of 560 nm to 640 nm, a pigment dispersant, and a solvent. A red pigment dispersion for color filters, characterized in that the dispersed pigment particles have an average dispersed particle diameter of 15 to 80 nm.
The present invention also includes a red pigment, a yellow or orange pigment having a light transmittance of 90% or more in a wavelength range of 560 nm to 640 nm, a pigment dispersant, a photosensitive binder component, A red photosensitive resin composition for a color filter comprising a solvent, wherein the dispersed pigment particles have an average dispersed particle diameter of 15 to 80 nm. provide.
[Test membrane]
30 parts by weight of the yellow or orange pigment and the pigment dispersant 7.5 so that x = 0.450 in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source A resin composition for test membranes comprising 24 to 24 parts by weight, 36 to 52.5 parts by weight of a methyl methacrylate / methacrylic acid copolymer (molar ratio 9/1) having a weight average molecular weight of 7000 to 15000 and 300 to 400 parts by weight of the solvent. An object is applied on an alkali-free glass substrate and dried to form a test film.

  According to the present invention, the pigment dispersion is achieved by adjusting the average dispersion particle size of the pigment particles that are toned and dispersed using the yellow or orange pigment having the specific light transmittance. A red pigment dispersion for color filters and a red photosensitive resin composition for color filters capable of forming a color filter having excellent properties and high contrast can be obtained.

  In the pigment dispersion and the photosensitive resin composition of the present invention, the yellow or orange pigment is 5 to 50% by weight in the total pigment, so that a specific color necessary for the red pixel of the color filter is obtained. It is preferable from the viewpoint of improving contrast while achieving it.

  In the pigment dispersion and the photosensitive resin composition of the present invention, the red pigment is at least one selected from the group consisting of CI Pigment Red 254, CI Pigment Red 177, CI Pigment Red 255, and CI Pigment Red 242. It is preferable from the viewpoint of improving contrast while achieving a specific color necessary for the red pixel of the color filter.

In the pigment dispersion and the photosensitive resin composition of the present invention, the yellow or orange pigment is CI pigment yellow 150 or a derivative pigment thereof, CI pigment yellow 185, CI pigment yellow 17, CI pigment yellow 138, CI pigment. It is necessary for the red pixel of the color filter to be at least one selected from the group consisting of Yellow 139, CI Pigment Yellow 173, CI Pigment Yellow 117, CI Pigment Orange 66, CI Pigment Orange 68, and CI Pigment Orange 69 It is preferable from the viewpoint of improving contrast while achieving a specific color.
In the pigment dispersion and the photosensitive resin composition of the present invention, in particular, the red pigment is CI Pigment Red 254 and / or Pigment Red 242 and CI Pigment Red 177, and the yellow or orange pigment is CI Pigment Yellow 150. Or it is preferable that it is the derivative pigment from the point which can improve contrast, setting a brightness | luminance high, achieving the specific color required for the red pixel of a color filter.

  In the pigment dispersion and the photosensitive resin composition of the present invention, in the dispersed pigment particles, the contrast is further improved when the pigment particles having a dispersed particle diameter of 5 nm or more and less than 100 nm are 99% or more of the total pigment particles. It is preferable from the point.

  In the pigment dispersion and the photosensitive resin composition of the present invention, the pigment dispersant contains a repeating unit derived from a tertiary or quaternary ammonium salt of dimethylaminoethyl (meth) acrylate, and / or A polyallylamine derivative is preferable from the viewpoint of high pigment dispersion performance in the combination of the solvent system and the organic pigment.

  In the pigment dispersion and the photosensitive resin composition of the present invention, the solvent is at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, butyl carbitol acetate (BCA), and cyclohexanone. Is preferable from the viewpoints of solubility of other components and applicability.

  In the photosensitive resin composition according to the present invention, 0.645 <x <0.655 in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source. When the cured film of the resin composition is formed, the ratio of the luminance that is transmitted when the cured film of the resin composition is sandwiched between two polarizing plates that are orthogonal or parallel (luminance / polarized light when the polarizing plates are parallel) The luminance at the time of crossing the plate is preferably 5500 or more from the viewpoint of achieving high contrast.

The color filter according to the present invention is characterized by including a colored layer formed using the photosensitive resin composition according to the present invention.
A display device according to the present invention includes the color filter according to the present invention.

The red pigment dispersion for a color filter and the red photosensitive resin composition for a color filter according to the present invention have an excellent pigment dispersibility and a toning effect that effectively utilizes the light transmittance of the pigment and the bright line of the backlight. There is an effect that it is possible to form a high-colored red colored layer and a color filter including the red colored layer.
The color filter and the display device of the present invention have an effect that high contrast can be realized by using the photosensitive resin composition according to the present invention.

It is a typical longitudinal section showing an example of a color filter concerning the present invention. It is typical sectional drawing about an example of a liquid crystal panel. It is typical sectional drawing about another example of a liquid crystal panel. It is a figure which shows the spectral luminance at the time of the polarizing plate of Example 1 of this invention and the comparative example 2 parallel. It is a figure which shows the spectral luminance at the time of the polarizing plate orthogonal of Example 1 and Comparative Example 2 of this invention. It is a figure which shows the spectral brightness at the time of the polarizing plate of Example 2 of this invention and the comparative example 6 parallel. It is a figure which shows the spectral luminance at the time of the polarizing plate orthogonal of Example 2 and Comparative Example 6 of this invention.

  The present invention relates to a red pigment dispersion for a color filter, a red photosensitive resin composition for a color filter, a color filter, and a display device. Hereinafter, the red pigment dispersion for the color filter and the manufacturing method thereof, the red photosensitive resin composition for the color filter, the color filter, and the display device will be described in order. In the present invention, light includes electromagnetic waves having wavelengths in the visible and invisible regions, and further includes radiation, and the radiation includes, for example, microwaves and electron beams. Specifically, it means an electromagnetic wave having a wavelength of 5 μm or less and an electron beam. In the present invention, (meth) acryl means either acryl or methacryl, (meth) acrylate means either acrylate or methacrylate, and (meth) acryloyl is , Meaning either acryloyl or methacryloyl.

1. Red pigment dispersion for color filter The red pigment dispersion for color filter according to the present invention is a yellow or orange color having a red pigment and a light transmittance of 90% or more in the wavelength range of 560 nm to 640 nm. A red pigment dispersion for a color filter containing a pigment, a pigment dispersant, and a solvent, wherein the dispersed pigment particles have an average dispersed particle diameter of 15 to 80 nm.
[Test membrane]
30 parts by weight of the yellow or orange pigment and the pigment dispersant 7.5 so that x = 0.450 in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source A resin composition for test membranes comprising 24 to 24 parts by weight, 36 to 52.5 parts by weight of a methyl methacrylate / methacrylic acid copolymer (molar ratio 9/1) having a weight average molecular weight of 7000 to 15000 and 300 to 400 parts by weight of the solvent. An object is applied on an alkali-free glass substrate and dried to form a test film.
The pigment dispersant and solvent used for preparing the test film are the pigment dispersant and solvent used in the pigment dispersion according to the present invention. More specifically, the test membrane resin composition is, for example, mixed and dispersed with 30 parts by weight of a yellow or orange pigment, 7.5 to 24 parts by weight of a pigment dispersant, and 46 to 58 parts by weight of a solvent. On the other hand, 36-52.5 parts by weight of methyl methacrylate / methacrylic acid copolymer (molar ratio 9/1) having a weight average molecular weight of 7000-15000 and 242-354 parts by weight of solvent are mixed, and the two mixtures are mixed. Can be formed. Further, the residual solvent amount in the test film after drying is usually 5% or less. Examples of the drying conditions include, after drying under reduced pressure, drying at a hot plate at 60 to 100 ° C. for 1 to 5 minutes.
In the present invention, the weight average molecular weight refers to a polystyrene equivalent value measured using gel permeation chromatography (GPC).

  Here, the dispersed particle diameter in the pigment dispersion of the present invention is a dispersed particle diameter of pigment particles dispersed in a dispersion medium containing at least a solvent, and is measured by a laser light scattering particle size distribution meter. is there. For particle size measurement using a laser light scattering particle size distribution meter, the solvent used in the pigment dispersion is appropriately diluted to a concentration that can be measured with the laser light scattering particle size distribution meter (eg, 500 times). It can be measured at 23 ° C. by a dynamic light scattering method using a laser light scattering particle size distribution meter (for example, Nanotrack particle size distribution measuring device UPA-EX150 manufactured by Nikkiso Co., Ltd.). The average dispersed particle size here is a volume average particle size.

  The pigment dispersion is a pigment composition (pigment content in the composition / total amount of the composition) that is preliminarily prepared in the pre-stage of preparing the resin composition described later. Specifically, the pigment content is 5% by weight or more. By mixing the pigment dispersion and at least the binder component, a resin composition having both the pigment dispersibility and the properties of the binder component can be prepared.

  According to the present invention, the average of the dispersed pigment particles toned and dispersed using a yellow or orange pigment whose light transmittance of the test film is 90% or more in the wavelength range of 560 nm to 640 nm. By adjusting the dispersion particle diameter to be 15 to 80 nm, it is possible to obtain a red pigment dispersion for a color filter that can form a color filter having excellent pigment dispersibility and high contrast.

The contrast ratio is a ratio of luminance on the display device (ON state / OFF state) when light must be transmitted (ON state) and when light must be blocked (OFF state). Therefore, in order to achieve high contrast, it is important to reduce the value of luminance (hereinafter sometimes referred to as orthogonal luminance), which is the denominator when light must be blocked (OFF state). . Furthermore, it is preferable to increase the luminance (hereinafter sometimes referred to as parallel luminance) when light must be transmitted (ON state), which becomes a molecule.
As a result of intensive studies in view of the above problems, the present inventors have determined that the average dispersed particle diameter of the dispersed pigment particles is 15 to 80 nm, and the light transmittance of the test film is 90 in the wavelength region of 560 to 640 nm. % Or more of yellow or orange pigments are combined with red pigments to adjust the parallel brightness without increasing the orthogonal brightness, resulting in a dramatic improvement in contrast. I found out.
When the above specific yellow or orange pigment is used in combination with a red pigment, and a red pigment dispersion composed only of a red pigment having an average dispersed particle size of 15 to 80 nm is used. Compared with, the contrast is greatly improved.
Furthermore, the contrast is dramatically improved as compared with the case of using a conventional red pigment dispersion in which the average dispersed particle size of the dispersed pigment particles is not appropriately controlled.

In the present invention, the dramatic improvement in contrast is considered to be due to the following reason.
That is, in the present invention, attention is paid to a wavelength range where the transmittance of the red pigment is not so high among the wavelength range where the red pigment of the bright line of the backlight is transmitted, 560 nm to 640 nm. For bright lines in the wavelength range of 560 nm to 640 nm, since the transmittance in the wavelength region is not so high with the red pigment alone, the parallel luminance is considerably lower than the parallel luminance in the case of air. On the other hand, since the red pigment does not have a high transmittance in this wavelength region, the scattered light of polarized light increases, and there is light that leaks to the OFF state, and the orthogonal luminance tends to increase.
On the other hand, in the present invention, a yellow or orange pigment having a transmittance of 90% or more in a wavelength region of 560 nm to 640 nm under a specific condition is selected. Partially replace with red pigment. The yellow or orange pigment whose transmittance is almost 100% in the wavelength range of 560 nm to 640 nm is the same as air in the OFF state with respect to the emission line in the wavelength range of 560 nm to 640 nm, and light does not leak, The orthogonal luminance is reduced by the amount replaced with the red pigment. Furthermore, in the present invention, since a yellow or orange pigment having a transmittance of 90% or more in a wavelength region of 560 nm to 640 nm under a specific condition is also used, parallel luminance with respect to an emission line in a wavelength range of 560 nm to 640 nm is used. It becomes possible to improve. Further, among yellow or orange pigments having a transmittance of 90% or more in the wavelength range of 560 nm to 640 nm, a pigment having an average dispersed particle diameter of 15 to 80 nm is selected and used. As a result, the light scattering of visible light occupies a large number of areas that are not affected by the Mii scattering, the influence of the particle size is reduced, the light leaking to the OFF state can be effectively reduced, and the orthogonal luminance increases. Can be prevented.

On the other hand, when a yellow or orange pigment having a transmittance of less than 90% in the wavelength range of 560 nm to 640 nm is used, the orthogonal luminance with respect to the bright line in the range of 560 nm to 640 nm is increased. An increase in the orthogonal luminance value of the denominator in the contrast ratio has a greater effect than an increase in the numerator value, so that the contrast cannot be improved even if the parallel luminance increases.
Further, even in the case of a yellow or orange pigment having a transmittance of 90% or more in the wavelength range of 560 nm to 640 nm, the average dispersed particle size of the pigment particles dispersed in the dispersion medium is not appropriately controlled. When many particles with a particle size of 100 nm or more are included, the particles with a dispersion particle size of 100 nm or more have the property of diffracting the scattered light depending on the size, so that the amount of scattered light of polarized light increases and the amount of light leaking to the OFF state increases. The orthogonal luminance increases in each bright line of the light, and the contrast decreases. Even when a finer pigment is used as a pigment, it is often aggregated in the dispersion medium, and the average dispersed particle diameter of the pigment particles actually dispersed in the dispersion medium becomes large as in Patent Document 1. There is a case.

  As described above, in the present invention, as a result of performing appropriate color matching using a specific pigment having a particle diameter of pigment particles dispersed and a transmittance of 90% or more in a wavelength range of 560 nm to 640 nm. It is estimated that the contrast (ON state (parallel luminance) / OFF state (orthogonal luminance)) can be remarkably improved because the parallel luminance can be improved while the increase of the orthogonal luminance can be suppressed.

The red pigment dispersion for a color filter of the present invention contains at least a pigment, a pigment dispersant and a solvent, and may contain other compounds as necessary.
Hereinafter, each configuration of the pigment dispersion of the present invention will be described in detail in order.

<Pigment>
The pigment used in the present invention contains at least a red pigment and a yellow or orange pigment having a light transmittance of 95% or more in the wavelength range of 560 nm to 640 nm. The red pigment and the yellow or orange pigment are appropriately selected depending on the use and specifications of the color filter. In order to achieve the required chromaticity, the red pigment and the specific yellow or orange pigment are used by mixing one or more of inorganic pigments and organic pigments. Moreover, unless the chromaticity required for the use and specification in a color filter can be achieved and the effect of this invention is not impaired, the other pigment may be further contained.
As organic pigments, for example, compounds classified as Pigments in the Color Index (CI; published by The Society of Dyers and Colorists), specifically, the following Color Index (CI) numbers are attached. Can be mentioned.

  Examples of red pigments include CI Pigment Red 1, CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 4, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Red 8, CI Pigment Red 9, CI Pigment Red 10, CI Pigment Red 11, CI Pigment Red 12, CI Pigment Red 14, CI Pigment Red 15, CI Pigment Red 16, CI Pigment Red 17, CI Pigment Red 18, CI Pigment Red 19, CI Pigment Red 21, CI Pigment Red 22, CI Pigment Red 23, CI Pigment Red 30, CI Pigment Red 31, CI Pigment Red 32, CI Pigment Red 37, CI Pigment Red 38, CI Pigment Red 40, C .I. Pigment Red 41, CI Pigment Red 42, CI Pigment Red 48: 1, CI Pigment Red 48: 2, CI Pigment Red 48: 3, CI Pigment Red 48: 4, CI Pigment Red 49: 1, CI Pigment Red 49: 2, CI Pigment Red 50: 1, CI Pigment Red 52: 1, CI Pigment Red 53: 1, CI Pigment Red 57, CI Pigment Red 57: 1, CI Pigment Red 57: 2, CI Pigment Red 58: 2 CI Pigment Red 58: 4, CI Pigment Red 60: 1, CI Pigment Red 63: 1, CI Pigment Red 63: 2, CI Pigment Red 64: 1, CI Pigment Red 81: 1, CI Pigment Red 83, CI Pigment Red 88, CI Pigment Red 90: 1 CI Pigment Red 97, CI Pigment Red 101, CI Pigment Red 102, CI Pigment Red 104, CI Pigment Red 105, CI Pigment Red 106, CI Pigment Red 108, CI Pigment Red 112, CI Pigment Red 113, CI Pigment Red 114, CI Pigment Red 122, CI Pigment Red 123, CI Pigment Red 144, CI Pigment Red 146, CI Pigment Red 149, CI Pigment Red 150, CI Pigment Red 151, CI Pigment Red 166, CI Pigment Red 168, CI Pigment Red 170, CI Pigment Red 171, CI Pigment Red 172, CI Pigment Red 174, CI Pigment Red 175, CI Pigment Red 176, C.I. I. Pigment Red 177, CI Pigment Red 178, CI Pigment Red 179, CI Pigment Red 180, CI Pigment Red 185, CI Pigment Red 187, CI Pigment Red 188, CI Pigment Red 190, CI Pigment Red 193, CI Pigment Red 194 CI Pigment Red 202, CI Pigment Red 206, CI Pigment Red 207, CI Pigment Red 208, CI Pigment Red 209, CI Pigment Red 215, CI Pigment Red 216, CI Pigment Red 220, CI Pigment Red 224, CI Pigment Red 226 CI Pigment Red 242, CI Pigment Red 243, CI Pigment Red 245, CI Pigment Red 254, CI Pigment Red 255, C.I. CI pigment red 264, C.I. pigment red 265, and the like.

  The red pigment having higher transmittance in the wavelength range of 560 nm to 640 nm can improve the parallel luminance with respect to the bright line in the range, so that the contrast (ON state (parallel luminance) / OFF state (orthogonal luminance)) can be improved. It is preferable from the point.

  Among these, at least one selected from the group consisting of CI Pigment Red 254, CI Pigment Red 177, CI Pigment Red 255, and CI Pigment Red 242 achieves a specific color necessary for the red pixel of the color filter. From the viewpoint of improving contrast. Among these, C.I. Pigment Red 254 and C.I. Pigment Red 242 are preferably used because they have high luminance and large parallel luminance and are easy to improve contrast, and C.I. Pigment Red 177 has low orthogonal luminance and high contrast. In particular, the combination of C.I. Pigment Red 254 and / or C.I. Pigment Red 242 and C.I. Pigment Red 177 is more preferably used from the viewpoint of achieving both the above-described effects.

  The yellow or orange pigment used in combination with the red pigment has a higher transmittance in the wavelength range of 560 nm to 640 nm, and can lower the orthogonal luminance in the range, while improving the parallel luminance with respect to the bright line in the range. Therefore, it is preferable from the viewpoint that the contrast (ON state (parallel luminance) / OFF state (orthogonal luminance)) can be improved. In particular, the light transmittance of the test film is preferably 90% or more in the wavelength region of 560 nm to 640 nm. Moreover, it is preferable that the transmittance | permeability is 2% or less in the wavelength range of 400 nm-480 nm.

Examples of yellow or orange pigments capable of achieving 90% or more of the light transmittance of the test film in the wavelength range of 560 nm to 640 nm include CI Pigment Yellow 150 or its derivative pigment, CI Pigment Yellow 185, CI Pigment. Examples include a group consisting of yellow 17, CI pigment yellow 138, CI pigment yellow 139, CI pigment yellow 173, CI pigment yellow 117, CI pigment orange 66, CI pigment orange 68, and CI pigment orange 69.
Among these, CI pigment yellow 150 or a derivative pigment thereof, CI pigment yellow 185, CI pigment yellow 17, CI pigment yellow 138, CI pigment yellow 139, CI pigment yellow 173, and CI pigment yellow 117 are preferably used.

  CI pigment yellow 150 derivative pigments specifically include mono, di, tri and tetra azo compounds according to formula (1) or one of its tautomeric structures acting as a host for at least one guest compound. Anions and metals Li, Cs, Mg, Cd, Co, Al, Cr, Sn, Pb, particularly preferably metals corresponding to Na, K, Ca, Sr, Ba, Zn, Fe, Ni, Cu, Mn and La Complex;

[In formula (1), R and R ′ are independently OH, NH ₂ , NH—CN, acylamino or arylamino, and R ¹ and R ^{1 ′} are independently —OH or — NH ₂ ]

  The following formula (2), which may optionally contain a guest compound:

[In the formula, rings with X and Y are ═O, ═S, ═NR ₇ , —NR ₆ R ₇ , —OR ₆ , —SR ₆ , —COOR ₆ , —CN, —CONR ₆ R, respectively. ₇ , —SO ₂ R ₈ ,

, Alkyl, cycloalkyl, aryl and aralkyl may have one or two substituents, and both ring X and ring Y have an endocyclic double bond and an exocyclic group. The total number of heavy bonds is 3, wherein R ₆ is hydrogen, alkyl, cycloalkyl, aryl or aralkyl, and R ₇ is hydrogen, cyano, alkyl, cycloalkyl, aryl, aralkyl or acyl. Wherein R ₈ is alkyl, cycloalkyl, aryl or aralkyl) R ₁ , R ₂ , R ₃ and R ₄ are hydrogen, alkyl, cycloalkyl, aryl or aralkyl, in addition to the formula As shown by the broken line in (2), a 5-membered ring or a 6-membered ring (this ring may be further condensed) At _{best, R} 5 is -OH, _-NR 6 _{R 7,} alkyl, cycloalkyl, aryl or aralkyl (wherein, _{R 6} and _{R 7} are as defined above), a CH group In the substituents R _{1 to} R ₈ having, the hydrogen atom in the CH group may be substituted, and m, n, o and p may be 1, and as another option, the formula (2 ), A double bond starts from the ring nitrogen atom where the corresponding substituents R _{1 to} R ₄ are located. Metal compound of the mutated structure;
Or the pigment | dye of Formula (3) or those tautomer structure and those hydrates which contain melamine as a guest can be mentioned.

These derivative pigments are disclosed in JP 2001-354869, JP 2005-325350, JP 2007-25687, JP 2007-23287, JP 2007-23288, and JP 2008. It can be obtained by referring to the publication -24927.

Even when the pigment has the pigment number, if the average dispersed particle size of the pigment particles is too large, or if the average dispersed particle size is small but coarse particles are present, the light transmittance of the test film is 560 nm. In some cases, 95% or more cannot be achieved in the wavelength range of ˜640 nm.
From this point, the yellow or orange pigment used in combination is preferably a material having a primary particle size distribution in the range of 5 to 100 nm, and the average dispersed particle size of dispersed pigment particles is 15 to 80 nm. Is preferred.

  The specific yellow or orange pigment is preferably 5 to 50% by weight in the total pigment from the viewpoint of improving the contrast while achieving the red chromaticity required for the specification of the color filter, Furthermore, it is preferable that it is 10 to 40 weight% in all the pigments.

In the present invention, in particular, the red pigment used in the present invention is CI pigment red 254 and / or pigment red 242 and CI pigment red 177, and the yellow or orange pigment is CI pigment yellow 150 or a derivative pigment thereof. It is preferable.
Further, CI Pigment Red 254 is 0 to 40 parts by weight, Pigment Red 242 is 0 to 40 parts by weight, CI Pigment Red 177 is 20 to 60 parts by weight, CI Pigment Yellow 150 or its derivative pigment is 10 to 50 parts by weight. It is preferable to set the pigment ratio within a range, CI Pigment Red 254 is 0 to 15 parts by weight, Pigment Red 242 is 5 to 49 parts by weight, CI Pigment Red 177 is 40 to 60 parts by weight, and CI Pigment Yellow 150 is 10 parts by weight. More preferably, it is -35 weight. By using such pigment types and their ratios, when achieving a desired color, a large amount of CI Pigment Red 177 having a high contrast improvement effect but the lowest transmittance in the wavelength range of 560 nm to 640 nm is used. Can be reduced to a level at which CI Pigment Red 254 and Pigment Red 242, which are necessary for improving the luminance performance of the desired color, are not the main pigments, although the transmittance in the wavelength range of 560 nm to 640 nm is low. As the effect of the present invention becomes more prominent, not only the contrast improvement effect is increased, but also the luminance performance can be achieved by increasing the amount of yellow or orange pigment.

  The method of refining the pigment used is not particularly limited as long as the dispersion particle size distribution as specified in the present invention is obtained when the pigment is dispersed in the dispersion medium. For example, a method of mechanically pulverizing pigment particles as typified by the solvent salt milling method, a method of returning the pigment particles to a molecular state once by dissolution, etc., and precipitating in a fine particle state using a temperature change or a poor solvent, Examples thereof include a method of directly producing fine particle pigments during pigment synthesis by controlling reaction conditions.

  The pigment is preferably blended in a proportion of 3 to 20% by weight, more preferably 5 to 15% by weight, based on the total amount of the red pigment dispersion for color filters.

<Pigment dispersant>
The pigment dispersant is further blended in the pigment dispersion to disperse the pigment satisfactorily. Examples of the pigment dispersant that can be used include cationic, anionic, nonionic, amphoteric, silicone, and fluorine surfactants. Among the surfactants, polymer surfactants (polymer dispersants) as exemplified below are preferable. A pigment derivative that dissolves in a small amount in a solvent may be used as a pigment dispersant.

  The pigment dispersant is appropriately selected and used in order to favorably disperse the pigment used. Specific examples include amide compounds such as nonanamide, decanamide, dodecanamide, N-dodecylhexadecanamide, N-octadecylpropioamide, N, N-dimethyldodecanamide and N, N-dihexylacetamide, diethylamine, diheptylamine, Amine compounds such as dibutylhexadecylamine, N, N, N ′, N′-tetramethylmethanamine, triethylamine, tributylamine and trioctylamine, monoethanolamine, diethanolamine, triethanolamine, N, N, N ′, N ′-(tetrahydroxyethyl) -1,2-diaminoethane, N, N, N′-tri (hydroxyethyl) -1,2-diaminoethane, N, N, N ′, N′-tetra (hydroxyethyl) Polyoxyethylene) -1,2-diaminoethane, 1 , 4-bis (2-hydroxyethyl) piperazine and amines having a hydroxy group such as 1- (2-hydroxyethyl) piperazine, and the like, and other compounds such as nipecotamide, isonipecotamide, and nicotinamide are listed. be able to.

  Further, (co) polymers of unsaturated carboxylic acid esters such as polyacrylic acid esters; (partial) amine salts, (partial) ammonium salts of (co) polymers of unsaturated carboxylic acid such as polyacrylic acid ( Partially) alkylamine salts; (co) polymers of hydroxyl group-containing unsaturated carboxylic acid esters such as hydroxyl group-containing polyacrylates and their modified products; polyurethanes; unsaturated polyamides; polysiloxanes; long-chain polyaminoamide phosphorus Acid salts; amides obtained by the reaction of poly (lower alkyleneimine) and free carboxyl group-containing polyester, salts thereof, and the like can be mentioned.

  Examples of the pigment dispersant used in the present invention include (co) polymers of unsaturated carboxylic acid esters such as polyacrylic acid esters; (partial) amine salts of (co) polymers of unsaturated carboxylic acid such as polyacrylic acid , (Partial) ammonium salts and (partial) alkylamine salts; hydroxyl group-containing unsaturated carboxylic acid ester (co) polymers such as hydroxyl group-containing polyacrylates and their modified products; polyurethanes; unsaturated polyamides; Siloxanes; Long-chain polyaminoamide phosphates; Amides obtained by the reaction of poly (lower alkylene imines) with free carboxyl group-containing polyesters and their salts are effective for dispersion in non-aqueous systems (solvent systems) It is preferable because it is a dispersant that can utilize steric hindrance and acid-base adsorption.

  Among them, the pigment dispersant used in the present invention is preferably a polymer containing a repeating unit derived from dimethylaminoethyl (meth) acrylate or a tertiary or quaternary ammonium salt of dimethylaminoethyl (meth) acrylate. Examples of the polymer include methyl (meth) acrylate, n-butyl (meth) acrylate, benzyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and γ-butyrolactone modified product of (meth) acrylic acid. Copolymers with other (meth) acrylic acid esters are preferably used, among which tertiary (or tertiary) of methyl (meth) acrylate and dimethylaminoethyl (meth) acrylate or dimethylaminoethyl (meth) acrylate. A copolymer containing a repeating unit derived from a quaternary ammonium salt is preferably used, and in particular, a quaternary ammonium salt such as poly (meth) methyl acrylate and polyblock (meth) acrylate dimethylaminoethyl or poly ( Tertiary amine sites such as methyl (meth) acrylate and polyblock (dimethylaminoethyl acrylate) The block copolymer salts modified with an acid such as phenylphosphonic sulfonic acid is preferably used.

  The pigment dispersant used in the present invention is preferably a polyallylamine derivative. The polyallylamine derivative preferably used as a pigment dispersant in the present invention is, for example, a polyester or polyamide having a side chain amino group and a free carboxyl group, or a co-condensate of polyester and amide (polyesteramide). A polyallylamine derivative represented by the following general formula (I) is obtained by reacting with one or more compounds selected from three kinds of compounds.

(Wherein X and Y are each independently hydrogen, a polymerization initiator residue or a chain transfer catalyst residue, R ¹ is a free amino group, represented by the following general formula (II) or (III) Wherein n represents an integer of 2 to 1,000, provided that at least one of n R ^{1 s} represents a group represented by formula (III).

In the formula, R ² represents a residue obtained by removing a carboxyl group from any of a polyester having a free carboxylic acid, a polyamide having a free carboxylic acid, or a polyester amide having a free carboxylic acid. )

  This polyallylamine derivative is, for example, a polyallylamine having a polymerization degree of 2 to 1,000, a polyester having a free carboxyl group, represented by the following general formula (IV) or (V), and the following general formula (VI) or One kind of polyamide represented by (VII) can be prepared as a raw material alone or in combination of two or more kinds.

(In the formula, R ³ represents a linear or branched alkylene group having 2 to 20 carbon atoms, and a represents an integer of 2 to 100.)

Wherein R ⁴ is a linear or branched alkylene group having 2 to 20 carbon atoms, C ₆ H ₄ or CH═CH, and R ⁵ is a linear or branched alkylene having 2 to 20 carbon atoms. A group, a residue obtained by removing two hydroxyl groups from polyalkylene glycol, and b represents an integer of 2 to 100. In addition, an ether bond may be present in the primary chain.)

(In the formula, R ⁶ represents a linear or branched alkylene group having 2 to 20 carbon atoms, and c represents an integer of 2 to 100.)

(Wherein R ⁴ is a linear or branched alkylene group having 2 to 20 carbon atoms, C ₆ H ₄ or CH═CH, and R ⁷ is a linear or branched alkylene group having 2 to 20 carbon atoms. A group, and d represents an integer of 2 to 100.)

  In addition, the polyallylamine derivative suitably used as a pigment dispersant in the present invention is a polyester in which repeating components of general formula (IV) and general formula (V) are randomly polymerized to polyallylamine, general formula (VI) and general A polyamide in which the repeating component of the formula (VII) is randomly polymerized, and further a polyesteramide in which the repeating components of the general formula (IV) and / or (V) and the general formula (VI) and / or (VII) are randomly polymerized. It can also be produced by reacting.

  Commercially available dispersants include Disperbyk-101, -116, -130, -140, -160, -161, -162, -163, -164, -166, and -167. -168, -170, -171, -174, -182, -182, -2000, -2001, and -2050 (above, manufactured by Big Chemie Japan Co., Ltd.), EFKA-4046, and- 4047 (manufactured by EFAK CHEMICALS), Solsperse 12000, 13240, 13940, 17000, 20000, 24000GR, 24000SC, 27000, 28000, 32000, 33500, 33500, 35200, 37500 (above, manufactured by Nippon Lubrizol Co., Ltd.), Addispar PB711, 82 , The 822,823,824 (or more, Ajinomoto Fine manufactured by Techno Co., Ltd.), and the like. Moreover, it is more preferable to use what refine | purified them in order to improve the reliability of a color filter.

  The pigment dispersant is preferably blended at a ratio of 20 to 80 parts by weight, and further 20 to 60 parts by weight with respect to 100 parts by weight of the pigment.

<Solvent>
The red pigment dispersion for a color filter according to the present invention contains a solvent for dispersing the pigment.
Examples of the solvent used in the pigment dispersion of the present invention include alcohol solvents such as methyl alcohol, ethyl alcohol, N-propyl alcohol, and i-propyl alcohol; cellosolv solvents such as methoxy alcohol and ethoxy alcohol; Carbitol solvents such as ethoxyethoxyethanol; ester solvents such as ethyl acetate, butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate and ethyl lactate; ketone solvents such as acetone, methyl isobutyl ketone and cyclohexanone; methoxyethyl acetate Cellosolve acetate solvents such as methoxypropyl acetate, methoxybutyl acetate, ethoxyethyl acetate, ethyl cellosolve acetate; methoxyethoxyethyl Carbitol acetate solvents such as cetate and ethoxyethoxyethyl acetate; ether solvents such as diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and tetrahydrofuran; N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, etc. Aprotic amide solvents; lactone solvents such as γ-butyrolactone; unsaturated hydrocarbon solvents such as benzene, toluene, xylene and naphthalene; saturated hydrocarbon solvents such as N-heptane, N-hexane and N-octane And organic solvents such as Among these solvents, cellosolve acetate solvents such as methoxyethyl acetate, ethoxyethyl acetate, and ethyl cellosolve acetate; carbitol acetate solvents such as methoxyethoxyethyl acetate, ethoxyethoxyethyl acetate, and butyl carbitol acetate (BCA); Ether solvents such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether and propylene glycol diethyl ether; ester solvents such as methyl methoxypropionate, ethyl ethoxypropionate and ethyl lactate are preferably used. Among them, the solvent used in the present invention is selected from the group consisting of propylene glycol monomethyl ether acetate (CH ₃ OCH ₂ CH (CH ₃ ) OCOCH ₃ ), propylene glycol monomethyl ether, butyl carbitol acetate (BCA), and cyclohexanone. It is preferable that it is 1 or more types from the point of the solubility of another component, and the applicability | paintability.

These solvents may be used alone or in combination of two or more.
The pigment dispersion according to the present invention is prepared by using the above solvent in a proportion of usually 60 to 85% by weight with respect to the total amount of the pigment dispersion containing the solvent. When the amount of the solvent is too small, the viscosity is increased, and the pigment dispersibility and the pigment dispersion stability with time are likely to be lowered. Moreover, when there are too many solvents, a pigment density | concentration will fall and it may be difficult to achieve the chromaticity coordinate which makes a resin composition the target after preparation.

<Other ingredients>
If necessary, the pigment dispersion according to the present invention may further contain a pigment dispersion auxiliary resin and other components.
Examples of the pigment dispersion auxiliary resin include a binder resin described below.

<Physical properties of pigment dispersion>
The pigment dispersion according to the present invention has an average dispersed particle diameter of 15 to 80 nm as measured with a laser light scattering particle size distribution meter. Among these, the average dispersed particle diameter of the pigment measured by a laser light scattering particle size distribution meter is preferably 15 to 70 nm, and more preferably 15 to 60 nm.

  In the pigment dispersion according to the present invention, among the dispersed pigment particles, the pigment particles having a dispersed particle size of 5 nm or more and less than 100 nm have 99% or more of the total pigment particles and have a similar average dispersed particle size. Even in this case, it is preferable in that the light leaking into the OFF state can be greatly reduced and the contrast can be drastically improved. If the dispersed pigment particles contain particles with a dispersed particle size of 100 nm or more, the particles with a dispersed particle size of 100 nm or more have a property of diffracting the scattered light depending on the size, so that the scattered light of polarized light increases, and the OFF state Light that leaks into the screen will be generated. When particles having a dispersed particle diameter of 100 nm or more are not included, even if the average dispersed particle diameter is the same, it is presumed that the influence of the particle size is almost eliminated and light leaking into the OFF state can be effectively reduced. In addition, among the dispersed pigment particles, it is preferable that the pigment particle having a dispersed particle size of 5 nm or more and less than 100 nm is 99.5% or more, more preferably 99.9% or more of the total pigment particles. In addition, 99% or more of the pigment particles having a dispersed particle diameter of 5 nm or more and less than 100 nm means 99% by volume or more.

  Among them, in the pigment dispersion according to the present invention, particles having a dispersed particle diameter of 1/5 or more of the absorption wavelength of the contained pigment are less than 1%, further less than 0.5%, particularly less than 0.1%. Preferably there is.

The dispersion particle size distribution of the pigment in the pigment dispersion is, among other things, in the dispersed pigment particles, the pigment particles having a dispersion particle size of 5 nm or more and less than 30 nm are 10 to 50% by volume of the total pigment particles, the dispersion particle size It is preferable that pigment particles having a particle diameter of 30 nm or more and less than 61 nm are 50 to 90% by volume, and pigment particles having a particle diameter of 61 nm or more and less than 100 nm are preferably 0 to 20% by volume. It is preferable that the pigment particles having a dispersion particle diameter of 30 nm or more and less than 61 nm are 58 to 79 volume% and the pigment particle having a dispersion particle diameter of 61 nm or more and less than 100 nm is 3 to 17 volume%.
Furthermore, it is preferable that the particle size is 45 nm or less when the cumulative particle size distribution is 50% by volume in all pigment particles.

  Further, after storing the pigment dispersion at 40 ° C. for 1 week, it was measured again at 23 ° C. by a dynamic light scattering method using a laser light scattering particle size distribution analyzer, and the average dispersed particle size before and after storage was measured. The dispersion stability can be examined on the basis of whether or not is increased by 10 nm. When the dispersion stability is high, the average dispersed particle diameter does not change and is less than 10 nm within the error range.

  In the present invention, after the dispersion of the pigment molecules proceeds, coarse particles having a specific size such as 100 nm or more in the dispersed pigment molecules or a primary particle size of less than 5 nm, for example, by centrifugation as described later. Fine particles can be stably dispersed by removing particles that cannot be present in a stable dispersion state, or particles that are in an unstable dispersion state that has been agglomerated because the surface treatment is not complete even at 5 nm or more. From the viewpoint of obtaining a dispersion liquid. Thus, when the unstable particles aggregated from the dispersion are removed, the remaining fine pigment particles are difficult to aggregate and can exist stably. Further, even in a resin composition prepared using this pigment dispersion, fine pigment particles hardly aggregate and exist stably as fine particles in the resin composition.

<Method for producing pigment dispersion>
The pigment dispersion of the present invention is prepared by mixing the above-mentioned pigment, the pigment dispersant, and if necessary, other components in the above-mentioned solvent in an arbitrary order and dispersing them using a known disperser. Can do.
Since the pigment dispersion liquid of the present invention contains a red pigment and a specific yellow or orange pigment, two or more kinds of pigments are included, but one pigment dispersion liquid is prepared for each one of the pigments. Thereafter, they may be mixed to obtain the red pigment dispersion of the present invention, or a red pigment dispersion may be obtained by dispersing two or more kinds of pigments at the same time.
Among them, the dispersion time varies up to the dispersion limit for each pigment, and the dispersion often exceeds the dispersion time. Therefore, the average dispersion particle size of the pigment particles specified in the present invention is obtained. It is preferable to prepare one pigment dispersion for each pigment and then mix them to obtain the green pigment dispersion of the present invention. In this case, if different dispersants are used for the respective pigments, they may be aggregated. Therefore, it is preferable that the types of the pigment dispersants used for dispersing the respective pigments are the same.

When producing a photosensitive resin composition later, after confirming that the dispersibility by a dispersing agent is not inhibited, you may add an alkali-soluble resin to a dispersion liquid previously. In this case, the pigment particles are less likely to come into contact with each other due to the steric hindrance of the alkali-soluble resin, and the effect of reducing the dispersant due to the dispersion stabilization and the dispersion stabilization effect can also be expected.
Examples of the dispersing machine for performing the dispersion treatment include roll mills such as two rolls and three rolls, ball mills such as a ball mill and a vibrating ball mill, bead mills such as a paint conditioner, a continuous disk type bead mill, and a continuous annular type bead mill. As a preferable dispersion condition of the bead mill, the bead diameter to be used is preferably 0.03 to 2.00 mm, and more preferably 0.10 to 1.0 mm.

  When dispersing the pigment, it is preferable to add zirconia beads or the like as appropriate and perform dispersion for about 1 to 5 hours using a paint shaker (manufactured by Asada Steel Corporation) or the like. Specifically, it is possible to disperse with 2 mm zirconia beads having a relatively large bead diameter for 1 hour and further with 0.1 mm zirconia beads having a relatively small bead diameter for 2 to 10 hours. Moreover, it is preferable to filter with a membrane filter of 0.5 to 0.1 μm after dispersion.

  In particular, in the case of dispersed pigment particles, when the pigment particle having a dispersed particle size of 5 nm or more and less than 100 nm is 99% or more of the total pigment particles, as described later, it is centrifuged for a short time at a high rotational speed of a specific value or more. It is preferable to further use a method of removing pigment particles having a dispersed particle diameter of 100 nm or more from pigment particles that are separated and classified and dispersed.

A method for producing a red pigment dispersion for a color filter in which pigment particles having a dispersion particle size of 5 nm or more and less than 100 nm are 99% or more of the total pigment particles is obtained by using the pigment dispersion obtained above as a pre-prepared pigment dispersion. It is preferable to have a coarse particle removing step of separating and removing pigment particles having a dispersed particle diameter of 100 nm or more by centrifuging the preliminarily prepared pigment dispersion at a maximum centrifugal force of 137000 × g for 1 to 60 minutes. In the centrifugal force, g = 9.8 m / s ² .
By centrifuging the preliminarily prepared pigment dispersion for 1 to 60 minutes at a maximum centrifugal force of 137,000 × g or more, pigment particles having a dispersed particle diameter of 100 nm or more can be selectively separated and removed from the dispersed pigment particles. It becomes possible. Under conditions such as centrifugation for 1 hour at a maximum centrifugal force of about 35000 × g, the entire pigment tends to settle, and pigment particles having a dispersed particle size of 100 nm or more cannot be selectively separated and removed. There wasn't. The pigment particles having a dispersed particle diameter of 100 nm or more are obtained by performing the centrifugal separation under the conditions of a high rotational speed that generates a maximum centrifugal force of 137,000 × g or more as shown in the present invention and a short time. It is possible to selectively separate and remove.
The method for producing such a pigment dispersion has a coarse particle removal step of separating and removing pigment particles having a dispersion particle size of 100 nm or more, so that the average dispersion particle size of dispersed pigment particles is 15 to 80 nm. In addition, in the dispersed pigment particles, it is possible to achieve a pigment dispersion in which the pigment particles having a dispersed particle diameter of 5 nm or more and less than 100 nm are 99% or more of the total pigment particles, and have excellent pigment dispersibility, contrast A red pigment dispersion for color filters and a red photosensitive resin composition for color filters capable of forming a high color filter can be obtained.

  The centrifuge used in the above step is not particularly limited as long as it can be centrifuged for 5 to 60 minutes with a maximum centrifugal force of 137000 × g or more. For example, the ultracentrifuge XL-100K manufactured by Beckman Coulter can be exemplified by setting Type 90Ti as a rotor and 13.5 ml quick-seal polyallomer tube as a centrifuge tube. Further, as the conditions for centrifugal separation, pigment particles having a dispersed particle diameter of 100 nm or more are selectively separated and removed most efficiently at a maximum centrifugal force of 137,000 × g or more and for 1 to 60 minutes. The conditions may be appropriately selected and used. That is, after selectively classifying pigment particles having a dispersed particle size of 100 nm or more, conditions are selected as appropriate so that particles having a dispersed particle size of less than 100 nm are not included in the fraction of pigment particles having a dispersed particle size of 100 nm or more. It is preferable to do.

  When the pigment particles having a dispersed particle diameter of 100 nm or more are classified by the centrifugal separator, the pigment particles having the dispersed particle diameter of 100 nm or more are selectively removed from the preliminarily prepared pigment dispersion in the dispersed pigment particles. As a method for selective removal, for example, the centrifuged sample that has entered the centrifuge tube is arbitrarily divided into several parts (generally 4 to 10 parts) from the supernatant and gently taken out in order from the top so as not to mix. Each separated sample is measured for particle size by a method using a laser light scattering particle size distribution meter, which will be described later, and by removing the lower sample from the portion of the sample containing pigment particles having a dispersed particle size of 100 nm or more, particles of 100 nm or more exist. Can be obtained.

  In this way, the pigment dispersion according to the present invention is obtained. This pigment dispersion is used as a preliminary preparation for preparing a red photosensitive resin composition for a color filter having excellent pigment dispersibility.

2. Red photosensitive resin composition for color filter The red photosensitive resin composition for a color filter according to the present invention has a light transmittance of 90% or more in a wavelength range of 560 nm to 640 nm with a red pigment and the following test film. A red photosensitive resin composition for a color filter comprising a yellow or orange pigment, a pigment dispersant, a photosensitive binder component, and a solvent, wherein the dispersed pigment particles have an average dispersed particle diameter of 15 to 80 nm. It is characterized by being.
30 parts by weight of the yellow or orange pigment and the pigment dispersant 7.5 so that x = 0.450 in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source A resin composition for test membranes comprising 24 to 24 parts by weight, 36 to 52.5 parts by weight of a methyl methacrylate / methacrylic acid copolymer (molar ratio 9/1) having a weight average molecular weight of 7000 to 15000 and 300 to 400 parts by weight of the solvent. An object is applied on an alkali-free glass substrate and dried to form a test film.
Here, the dispersed particle diameter of the pigment particles in the red photosensitive resin composition for a color filter of the present invention is the dispersed particle diameter of the pigment particles dispersed in the photosensitive resin composition, and is a laser light scattering particle size distribution meter. It is measured by. The particle size can be measured with a laser light scattering particle size distribution meter using the solvent used in the red photosensitive resin composition for color filters, and the red photosensitive resin composition for color filters can be measured with a laser light scattering particle size distribution meter. Diluted to a suitable concentration (for example, 500 times) and measured at 23 ° C. by a dynamic light scattering method using a laser light scattering particle size distribution meter (for example, Nikkiso Nanotrac particle size distribution analyzer UPA-EX150). can do. The average dispersed particle size here is a volume average particle size.

  The red photosensitive resin composition for a color filter according to the present invention performs toning using a pigment capable of reducing orthogonal luminance and increasing parallel luminance in a wavelength region where a red pigment transmits. In addition, by controlling the dispersed particle diameter of the dispersed pigment, it has the same effect as described in the pigment dispersion, and by excellent color dispersibility and toning that effectively uses the bright line of the backlight. It is presumed that a red photosensitive resin composition for a color filter capable of forming a color filter with high contrast can be obtained.

The red photosensitive resin composition for a color filter according to the present invention contains at least a pigment, a pigment dispersant, a photosensitive binder component, and a solvent, and may contain other compounds as necessary. is there.
As the pigment, the pigment dispersant, and the solvent, the same pigments as those described for the red pigment dispersion for the color filter can be used, and the description thereof is omitted here.

<Photosensitive binder component>
In the present invention, from the point of imparting sufficient strength, durability, and adhesion to the coating film, after forming a pattern on the substrate by coating or transfer, the coating film can be cured by a polymerization reaction. A binder component is used. In addition to the photosensitive binder component described below, a thermosetting binder component that can be polymerized and cured by heating such as an epoxy resin may be further used. In preparing the resin composition according to the present invention using the pigment dispersion according to the present invention having excellent pigment dispersibility and pigment dispersion stability over time, the excellent pigment dispersibility and pigment dispersion stability over time are inhibited. In order to avoid this, it is necessary to select a binder component appropriately.

The photosensitive binder component contains a photo-curable resin that can be polymerized and cured by light such as ultraviolet rays and electron beams, and the exposed portion is cured and the unexposed portion is dissolved and removed to dissolve and remove the uncoated portion. Negative-type photosensitive binder components that can be prepared.
In the red photosensitive resin composition for a color filter according to the present invention, a negative photosensitive binder component is preferable because a pattern can be easily formed using an existing process by a photolithography method.

  A negative photosensitive binder component containing a photocurable resin that can be polymerized and cured by light such as ultraviolet rays and electron beams comprises (i) an alkali-soluble resin, (ii) a polyfunctional monomer, and (iii) a photopolymerization initiator. And a sensitizer and the like.

(I) Alkali-soluble resin The alkali-soluble resin in the present invention has a carboxyl group in the side chain, acts as the binder resin, and is preferably soluble in an alkali developer, especially used for pattern formation. As long as it is, it can be appropriately selected and used.
The preferred alkali-soluble resin in the present invention is a resin having a carboxyl group, and specific examples thereof include an acrylic copolymer having a carboxyl group and an epoxy (meth) acrylate resin having a carboxyl group. Among these, particularly preferred are those having a carboxyl group in the side chain and further having a photopolymerizable functional group such as an ethylenically unsaturated group in the side chain. It is because the film | membrane intensity | strength of the cured film formed by containing a photopolymerizable functional group improves. These acrylic copolymers and epoxy acrylate resins may be used in combination of two or more.

The acrylic copolymer having a carboxyl group is obtained by copolymerizing a carboxyl group-containing ethylenically unsaturated monomer and an ethylenically unsaturated monomer.
The acrylic copolymer having a carboxyl group may further contain a structural unit having an aromatic carbocyclic ring. The aromatic carbocycle functions as a component that imparts coating properties to the photosensitive resin composition.
The acrylic copolymer having a carboxyl group may further contain a structural unit having an ester group. The structural unit having an ester group functions as a component that suppresses alkali solubility of the photosensitive resin composition.

  Moreover, as said acrylic copolymer containing a photopolymerizable functional group, glycidyl (meth) acrylate, 3,4-epoxy cyclohexylmethyl (meth) with respect to some carboxyl groups of the said acrylic copolymer. React the epoxy group of a compound having an epoxy group and an ethylenically unsaturated group in one molecule such as acrylate, 4- (2,3-epoxypropyl) butyl (meth) acrylate, allyl glycidyl ether, etc. The side chain obtained by reacting an isocyanate group of a compound having an isocyanate group and an ethylenically unsaturated group in one molecule such as 2-methacryloyloxyethyl isocyanate with respect to a part or all of the hydroxyl groups of the coalescence is not ethylenic. An acrylic copolymer having a saturated group can also be used.

  The copolymerization ratio of the carboxyl group-containing ethylenically unsaturated monomer in the carboxyl group-containing copolymer is usually 5 to 50% by weight, preferably 10 to 40% by weight. In this case, when the copolymerization ratio of the carboxyl group-containing ethylenically unsaturated monomer is less than 5% by weight, the solubility of the resulting coating film in an alkaline developer is lowered, and pattern formation becomes difficult. On the other hand, when the copolymerization ratio exceeds 50% by weight, there is a tendency that the formed pattern is easily detached from the substrate or the pattern surface is roughened during development with an alkali developer.

  The preferred molecular weight of the carboxyl group-containing copolymer is preferably in the range of 1,000 to 500,000, more preferably 3,000 to 200,000. If it is less than 1,000, the binder function after curing is remarkably lowered, and if it exceeds 500,000, pattern formation may be difficult during development with an alkaline developer.

Although it does not specifically limit as epoxy (meth) acrylate resin which has a carboxyl group, The epoxy (meth) obtained by making the reaction product of an epoxy compound and unsaturated group containing monocarboxylic acid react with an acid anhydride. Acrylate compounds are suitable.
Although it does not specifically limit as an epoxy compound, A bisphenol A type epoxy compound, a bisphenol F type epoxy compound, a bisphenol S type epoxy compound, a phenol novolak type epoxy compound, a cresol novolak type epoxy compound, an aliphatic epoxy compound, or Examples thereof include epoxy compounds such as bisphenolfluorene type epoxy compounds. These may be used alone or in combination of two or more.

  Examples of the unsaturated group-containing monocarboxylic acid include (meth) acrylic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl phthalic acid, (meth) acryloyloxyethyl hexahydrophthalic acid, (Meth) acrylic acid dimer, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, α-cyanocinnamic acid and the like. Also, half-ester compounds that are reaction products of hydroxyl group-containing acrylates with saturated or unsaturated dibasic acid anhydrides, reaction products of unsaturated group-containing monoglycidyl ethers with saturated or unsaturated dibasic acid anhydrides. A half ester compound is also mentioned. These unsaturated group-containing monocarboxylic acids may be used alone or in combination of two or more.

Acid anhydrides include maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, methylendo Dibasic acid anhydrides such as methylenetetrahydrophthalic acid, chlorendic anhydride, methyltetrahydrophthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic dianhydride, biphenyltetracarboxylic dianhydride, biphenyl Aromatic polycarboxylic acid anhydrides such as ether tetracarboxylic acid, 5- (2,5-dioxotetrahydrofuryl) -3-methyl-3-cyclohexene-1,2-dicarboxylic acid anhydride, endobicyclo- [2 , 2,1] -Hept-5-ene-2,3-dica Polycarboxylic anhydride derivatives such as carbon anhydride, and the like. These may be used alone or in combination of two or more.
The molecular weight of the epoxy (meth) acrylate compound having a carboxyl group thus obtained is not particularly limited, but is preferably 1000 to 40000, more preferably 2000 to 5000.

(Ii) Polyfunctional monomer Examples of the polyfunctional monomer in the present invention include di (meth) acrylates of alkylene glycol such as ethylene glycol and propylene glycol; di (meth) acrylate of polyalkylene glycol such as polyethylene glycol and polypropylene glycol. ) Acrylates; poly (meth) acrylates of polyhydric alcohols such as glycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, etc. and their dicarboxylic acid modified products; polyesters, epoxy resins, urethane resins, alkyd resins , Oligo (meth) acrylates such as silicone resins and spirane resins; both ends such as hydroxypoly-1,3-butadiene at both ends, hydroxypolyisoprene at both ends, and hydroxypolycaprolactone at both ends Di hydroxylated polymer (meth) acrylates; tris (2- (meth) acryloyloxyethyl) phosphate and the like.

  Of these polyfunctional monomers, poly (meth) acrylates of polyhydric alcohols having three or more valences and their dicarboxylic acid-modified products are preferable. Specifically, trimethylolpropane tri (meth) acrylate, pentaerythritol tris. Succinic acid modified products of (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like are preferable. The said polyfunctional monomer can be used individually or in mixture of 2 or more types.

  The usage-amount of the polyfunctional monomer in this invention is 5-500 weight part normally with respect to 100 weight part of alkali-soluble resin, Preferably it is 20-300 weight part. In this case, when the amount of the polyfunctional monomer used is less than 5 parts by weight, the pattern strength and the smoothness of the pattern surface tend to be reduced. On the other hand, when it exceeds 500 parts by weight, for example, alkali developability is reduced, There is a tendency that stains and film residues are likely to occur in regions other than the portion where the pattern is formed.

  In the present invention, a part of the polyfunctional monomer can be replaced with a monofunctional monomer. Examples of such monofunctional monomers include carboxyl group-containing unsaturated monomers or other unsaturated monomers constituting alkali-soluble resins, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-phenoxypropyl. A methacrylate etc. can be mentioned. Among these monofunctional monomers, succinic acid mono (2-acryloyloxyethyl), succinic acid mono (2-methacryloyloxyethyl), ω-carboxypolycaprolactone monoacrylate, ω-carboxypolycaprolactone monomethacrylate, methoxy Triethylene glycol acrylate, methoxytriethylene glycol methacrylate, methoxydipropylene glycol acrylate, methoxydipropylene glycol methacrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-phenoxypropyl methacrylate and the like are preferable. The monofunctional monomers can be used alone or in admixture of two or more. The proportion of the monofunctional monomer used is usually 90% by weight or less, preferably 50% by weight or less, based on the total amount of the polyfunctional monomer and the monofunctional monomer.

(Iii) Photopolymerization initiator and sensitizer The negative photosensitive binder component is usually blended with a photopolymerization initiator having activity with respect to the wavelength of the light source used. The photopolymerization initiator is appropriately selected in consideration of the difference in the reaction format of the polymer having photopolymerization and the photopolymerization monomer (for example, radical polymerization and cationic polymerization) and the kind of each material, and is not particularly limited.

  Examples of photopolymerization initiators are compounds that generate free radicals by the energy of ultraviolet rays, and include biimidazole compounds, benzoin compounds, acetophenone compounds, benzophenone compounds, α-diketone compounds, and polynuclear quinone compounds. , Xanthone compounds, thioxanthone compounds, triazine compounds, ketal compounds, azo compounds, peroxides, 2,3-dialkyldione compounds, disulfide compounds, thiuram compounds, fluoroamine compounds, etc. . These can be used alone or in combination.

  Moreover, in this invention, 1 or more types chosen from the group of a sensitizer and a hardening accelerator can also be further used together with the said photoinitiator as needed. Specific examples of the sensitizer include 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4-diethylaminoacetophenone, 4-dimethylaminopropiophenone, ethyl-4- Dimethylaminobenzoate, 2-ethylhexyl-1,4-dimethylaminobenzoate, 2,5-bis (4-diethylaminobenzal) cyclohexanone, 7-diethylamino-3- (4-diethylaminobenzoyl) coumarin, 4- (diethylamino) chalcone Etc. Specific examples of the curing accelerator include 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercapto-4, Examples include chain transfer agents such as 6-dimethylaminopyridine, 1-phenyl-5-mercapto-1H-tetrazole, and 3-mercapto-4-methyl-4H-1,2,4-triazole.

<Other ingredients>
If necessary, the red photosensitive resin composition for color filters according to the present invention may further contain a surfactant, an adhesion promoter, an ultraviolet absorber, a surface conditioner (leveling agent), or other components. May be.

(Surfactant)
Furthermore, when various surfactants are used in combination, the dispersion stability can be improved. Examples of the surfactant include cationic, anionic, nonionic, amphoteric, silicone, and fluorine surfactants. For example, polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether and polyoxyethylene oleyl ether; polyoxyethylene such as polyoxyethylene n-octylphenyl ether and polyoxyethylene n-nonylphenyl ether Examples include alkylphenyl ethers; polyethylene glycol diesters such as polyethylene glycol dilaurate and polyethylene glycol distearate; sorbitan fatty acid esters; fatty acid-modified polyesters; tertiary amine-modified polyurethanes; and polyethyleneimines.
The product names of the surfactants are KP (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow (manufactured by Kyoeisha Chemical Co., Ltd.), F-Top (manufactured by Tochem Products Co., Ltd.), Megafac (Dainippon Ink Chemical Co., Ltd.) )), Florard (manufactured by Sumitomo 3M Co., Ltd.), Asahi Guard, Surflon (manufactured by Asahi Glass Co., Ltd.), and the like.

(Adhesion promoter)
Examples thereof include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane.

(UV absorber)
For example, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, alkoxybenzophenone, and the like can be given.
(Leveling agent)
Examples thereof include commercially available silicon-based, polyoxyalkylene-based, fatty acid ester-based, and special acrylic polymers.

<Combination ratio of each component in the resin composition>
A pigment is mix | blended in the ratio of 10 to 40 weight% with respect to the solid content whole quantity of the photosensitive resin composition, More preferably, it is 15 to 35 weight%. If the amount of the pigment is too small, the transmission density when the photosensitive resin composition is applied to a predetermined film thickness (usually 1.0 to 4.0 μm) may not be sufficient. If the amount of the pigment is too large, the photosensitive property may be insufficient. There is a possibility that the properties as a coating film such as adhesion to the substrate when the resin composition is applied and cured on the substrate, surface roughness of the cured film, and coating film hardness may be insufficient, and its photosensitivity. Since the ratio of the amount of the dispersant used for dispersing the pigment in the resin composition increases, characteristics such as developability and heat resistance may be insufficient.
Here, the solid content for specifying the blending ratio includes all components except the solvent, and liquid polymerizable monomers and the like are also included in the solid content.
The pigment dispersant content is preferably 20 to 80 parts by weight, more preferably 20 to 60 parts by weight, based on 100 parts by weight of the total amount of pigment.
The total amount of the photosensitive binder component is preferably 15 to 95% by weight, preferably 25 to 80% by weight, based on the total solid content of the photosensitive resin composition.

In the red photosensitive resin composition for a color filter in the present invention, the weight ratio (P / V) of the whole pigment (P) and the solid content (V) other than the pigment is 0.1 to 5.0. It is preferable that it is 0.3-3.0.
In the present invention, the solid content concentration of the red photosensitive resin composition for color filters is adjusted to 5 to 70% by weight using a solvent.

<Method for producing red photosensitive resin composition for color filter>
The red photosensitive resin composition for a color filter of the present invention is prepared by adding a pigment and a photosensitive binder component together with other blending components as necessary, into a single solvent or a solvent that is a mixed solvent, and mixing them. It can also be produced by dissolving or dispersing solid components by a method.
However, in the above method, a large amount of the pigment cannot be sufficiently dispersed in the solvent, and as a result, the dispersed particle size distribution of the pigment of the present invention may not be achieved. Therefore, it is preferable to prepare the pigment dispersion liquid according to the present invention in advance, and prepare a binder liquid in which other components such as a binder component are mixed, dispersed or dissolved with a solvent. Then, by mixing the obtained pigment dispersion and the binder liquid according to the present invention and performing a dispersion treatment as necessary, the red photosensitive resin for color filters having excellent pigment dispersibility and pigment dispersion stability over time. A composition is easily obtained.

  If the pigment dispersion is not prepared in advance, first add the pigment and the pigment dispersant to the solvent, mix well, stir to disperse the pigment, and after passing through the coarse particle removal step using centrifugation as appropriate It is preferable to produce the mixture by adding and mixing the remaining components including the binder component. By blending a binder component and the like after pigment dispersion, not only does the pigment dispersibility not be inhibited by the binder component and other blending components in the pigment dispersion step, but also the pigment dispersion stability is excellent.

<Physical properties of red photosensitive resin composition for color filter>
In the photosensitive resin composition according to the present invention, the dispersed pigment particles have an average dispersed particle diameter of 15 to 80 nm. Among these, the average dispersed particle diameter of the pigment measured by a laser light scattering particle size distribution meter is preferably 15 to 60 nm, and more preferably 15 to 50 nm.

  In the photosensitive resin composition according to the present invention, among the dispersed pigment particles, it is preferable that the pigment particles having a dispersed particle size of 5 nm or more and less than 100 nm are 99% or more of the total pigment particles. Even if it has, it is preferable at the point which can reduce the light which leaks into an OFF state significantly, and can improve contrast drastically. If the dispersed pigment particles contain particles with a dispersed particle size of 100 nm or more, the particles with a dispersed particle size of 100 nm or more have a property of diffracting the scattered light depending on the size, so that the scattered light of polarized light increases, and the OFF state Light that leaks into the screen will be generated. When particles having a dispersed particle diameter of 100 nm or more are not included, even if the average dispersed particle diameter is the same, it is presumed that the influence of the particle size is almost eliminated and light leaking into the OFF state can be effectively reduced. In addition, among the dispersed pigment particles, it is preferable that the pigment particle having a dispersed particle size of 5 nm or more and less than 100 nm is 99.5% or more, more preferably 99.9% or more of the total pigment particles. In addition, 99% or more of the pigment particles having a dispersed particle diameter of 5 nm or more and less than 100 nm means 99% by volume or more.

  Among them, in the photosensitive resin composition according to the present invention, particles having a dispersed particle diameter of 1/5 or more of the absorption wavelength of the contained pigment are less than 1%, more preferably less than 0.5%, particularly 0.1%. It is preferable that it is less than.

The dispersion particle size distribution of the pigment in the photosensitive resin composition is, among other things, in the dispersed pigment particles, the pigment particles having a dispersion particle size of 5 nm or more and less than 30 nm are dispersed in an amount of 10 to 50% by volume of the total pigment particles. The pigment particles having a particle size of 30 nm or more and less than 61 nm are preferably 50 to 90% by volume, and the pigment particles having a particle size of 61 nm or more and less than 100 nm are preferably 0 to 20% by volume. It is preferable that 14 to 37% by volume of the particles, 58 to 81% by volume of pigment particles having a dispersed particle diameter of 30 nm to less than 61 nm, and 3 to 12% by volume of pigment particles having a dispersed particle diameter of 61 nm to less than 100 nm.
Furthermore, it is preferable that the particle size is 45 nm or less when the cumulative particle size distribution is 50% by volume in all pigment particles.

  In addition, after storing the resin composition at 40 ° C. for 1 week, the dispersion particle size of the pigment particles is measured again in the same manner, and the dispersion stability is determined based on whether the average dispersion particle size before and after storage is 10 nm larger. Sex can be examined. When the dispersion stability is high, the average dispersed particle diameter does not change and is less than 10 nm within the error range.

<Curing film for color filter>
The thus obtained red photosensitive resin composition for a color filter is formed by coating the composition on a support to form a coating film, drying it, and then irradiating the coating film with light in a predetermined pattern. Then, after changing the solubility between the exposed part and the unexposed part, such as selectively curing a part of the coating film, a cured film having a predetermined pattern is obtained by developing with an alkaline solution.

As a light beam used for the curing reaction, a light beam having a wavelength causing a reaction of the photosensitive binder component is appropriately selected and used from radiation such as ultraviolet rays and ionizing radiation or visible light. Irradiation energy required for curing is typically, 10 to 500 mJ / m ² approximately. In the exposure step, a predetermined position of the coating film can be selectively exposed and cured by irradiating the surface of the coating film with laser light or irradiating light through a mask.

The cured film for a color filter formed using the photosensitive resin composition according to the present invention can achieve high contrast while achieving a specific color necessary for the colored layer of the color filter.
A transmission electron microscope is used to confirm whether the dispersion average particle diameter in the cured film or whether particles of 100 nm or more are present in the cured film. For example, a cured film for a color filter is thinned in a cross-sectional direction by a FIB (focused ion beam apparatus) (for example, FB-2000A manufactured by Hitachi), and a cross-sectional TEM sample thereof is transmitted through a transmission electron microscope (for example, JEM-200CX manufactured by JEOL Ltd. Observation is performed at 10,000 to 500,000 times at a voltage of 100 kV), and the major axis of each particle is measured. The average can be obtained from the major axis of all pigment particles in the observation sample, and the particle size distribution can be obtained by measuring the total number of pigment particles in the observation sample and the number of pigment particles of less than 5 nm and 100 nm or more. it can. Therefore, in the dispersed pigment particles, the pigment particles having a dispersed particle diameter of 5 nm or more and less than 100 nm are 99% or more of all pigment particles. The pigment particles having a particle diameter of 5 nm or more and less than 100 nm after dispersion are 99% of all pigment particles. That means that.

Ratio of transmitted luminance when the cured film of the photosensitive resin composition according to the present invention is sandwiched by combining two polarizing plates so as to be orthogonal or parallel ((luminance when polarizing plate is parallel / polarizing plate orthogonal) Brightness), also simply referred to as “contrast” in the present invention, is preferably 5500 or more, and more preferably 5700 or more.
More specifically, the red photosensitive resin composition has a curing of 0.645 <x <0.655 in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source. When the film is formed, the contrast is preferably 5500 or more.

In addition, the said contrast in this invention is a value at the time of measuring as follows more specifically.
Luminance is measured using a contrast measuring device CT-1 manufactured by Aisaka Electric (light source: F10 lamp between cold cathodes, luminance meter: LS-100 manufactured by Konica Minolta, spectral luminance meter: CS-1000T manufactured by Konica Minolta). The contrast can be derived from the following formula using the measured luminance value.
Contrast = parallel luminance (cd / m ² ) / orthogonal luminance (cd / m ² )

3. Color filter The color filter according to the present invention includes a colored layer formed using the red photosensitive resin composition for a color filter according to the present invention.
The color filter according to the present invention includes a colored layer formed using the red photosensitive resin composition for a color filter according to the present invention, thereby achieving a high contrast while realizing a spectral spectrum necessary for the color filter. Is feasible.

FIG. 1 is a longitudinal sectional view showing an example (color filter 103) of a color filter for a display device belonging to the color filter according to the present invention.
The color filter 103 covers the light shielding layer 6 formed in a predetermined pattern on the transparent substrate 5, the colored layer 7 (7R, 7G, 7B) formed in a predetermined pattern on the light shielding layer, and the colored layer. The protective film 8 formed in this way is provided. A transparent electrode 9 for driving liquid crystal may be formed on the protective film as necessary. An alignment film 10 is formed on the innermost surface of the color filter 103, in this case on the transparent electrode.

  The columnar spacer 12 has a shape of a convex spacer, and is formed at a plurality of predetermined positions on the transparent electrode 9 in accordance with the region (non-display region) where the light shielding layer 6 is formed. The columnar spacer 12 is formed on the transparent electrode 9, the colored layer 7, or the protective film 8. In the color filter 103, columnar spacers are formed in a sea island shape on the protective film 8 via the transparent electrode 9, but the protective film 8 and the columnar spacer 12 are integrally formed and transparent so as to cover it. An electrode layer may be formed.

  The transparent substrate 5 of the color filter 101 is a transparent rigid material having no flexibility such as quartz glass, Pyrex (registered trademark) glass, or synthetic quartz plate, or a flexibility such as a transparent resin film or an optical resin plate. The transparent flexible material which has can be used. Among them, Corning 1737 glass is a material having a small coefficient of thermal expansion, excellent in dimensional stability and workability in high-temperature heat treatment, and is an alkali-free glass containing no alkali component in the glass. Suitable for filters.

The light shielding layer 6 is provided so as to surround between the colored layers 7R, 7G, and 7B and the outside of the colored layer forming region in order to improve the contrast of the display image. In the present invention, the light shielding layer 6 is preferably formed using a resin composition containing light shielding particles. For example, when the resin composition for forming a light shielding layer has alkali developability, first, the resin composition for forming a light shielding layer is applied onto the transparent substrate 5 and dried as necessary to form a photosensitive coating film. The light-shielding layer 6 can be formed by forming, exposing and developing the coating film through a photomask for the light-shielding layer, and performing heat treatment as necessary. On the other hand, when the light shielding layer forming resin composition is a thermosensitive resin composition or has no alkali developability, the light shielding layer forming resin composition is printed on a predetermined region on the transparent substrate 5, After selectively attaching by thermal transfer or the like, the light shielding layer 6 can be formed by curing by heating or light irradiation.
The thickness of the light shielding layer varies depending on the color filter to be applied, and is about 0.5 to 2.5 μm.

The colored layer 7 includes a red pattern, a green pattern, and a blue pattern arranged in a desired form such as a mosaic type, a stripe type, a triangle type, and a four colored layer arrangement type, thereby forming a display region.
In addition to the red photosensitive resin composition according to the present invention, green and blue photosensitive resin compositions are prepared. Next, a certain color, for example, a red photosensitive resin composition is applied on the transparent substrate 5 so as to cover the light shielding layer 6 by a known method such as spin coating to form a photosensitive red resin layer. The red colored layer 7R is formed by performing exposure through a photomask for use, and after alkali development and heat curing in a clean oven or the like. Thereafter, green and blue photosensitive resin compositions are sequentially used to pattern each color in the same manner to form a green colored layer 7G and a blue colored layer 7B.
The thickness of the colored layer is usually about 0.5 to 2.5 μm.

The protective film 8 is provided to flatten the surface of the color filter and prevent the components contained in the colored layer 7 from eluting into the liquid crystal layer. The protective film 8 covers the light-shielding layer 6 and the colored layer 7 with a known negative photocurable transparent resin composition or thermosetting transparent resin composition by a method such as spin coater, roll coater, spraying, printing, or the like. And can be formed by curing with light or heat.
When forming the protective film, the thickness of the protective film is set in consideration of the light transmittance of the resin composition, the surface state of the color filter, and the like, and is, for example, about 0.1 to 2.0 μm. When using a spin coater, the number of revolutions is set within a range of 500 to 1500 revolutions / minute.

  The transparent electrode film 9 on the protective film is made of indium tin oxide (ITO), zinc oxide (ZnO), tin oxide (SnO), etc., and alloys thereof, such as sputtering, vacuum deposition, CVD, etc. It is formed by a general method, and is formed into a predetermined pattern by etching using a photoresist or using a jig as necessary. The thickness of the transparent electrode can be about 20 to 500 nm, preferably about 100 to 300 nm.

  A plurality of convex spacers are provided in a non-display area on the substrate in order to maintain a cell gap when the color filter 103 is bonded to a liquid crystal driving side substrate such as a TFT array substrate. The shape and size of the convex spacer are not particularly limited as long as it can be selectively provided in a non-display region on the substrate and can maintain a predetermined cell gap over the entire substrate. When the columnar spacer 12 as shown in the figure is formed as the convex spacer, it has a certain height in the range of about 2 to 10 μm, and the protruding height (pattern thickness) is required for the liquid crystal layer. It can set suitably from thickness etc. Moreover, the thickness of the columnar spacer 12 can be appropriately set within a range of about 5 to 20 μm. Further, the formation density (density) of the columnar spacers 12 can be appropriately set in consideration of the thickness unevenness of the liquid crystal layer, the aperture ratio, the shape and material of the columnar spacers, for example, red, green and blue Necessary and sufficient spacer function is expressed at a ratio of one for each colored layer. The shape of such a columnar spacer may be a columnar shape, and may be, for example, a columnar shape, a prismatic shape, a truncated cone shape, or the like.

  The convex spacer can be formed using a photosensitive resin composition. That is, first, the coating liquid of the photosensitive resin composition is applied directly on the transparent substrate by a method such as spin coater, roll coater, spray, printing, or through another layer such as a transparent electrode, and then dried. Then, a photocurable resin layer is formed. The rotational speed of the spin coater may be set within a range of 500 to 1500 revolutions / minute, as in the case of forming the protective film. Next, this resin layer is exposed through a photomask for convex spacers, and developed with a developer such as an alkaline solution to form a predetermined convex pattern. A convex spacer is formed by heat treatment (post-bake) or the like.

The convex spacer can be provided directly on the color filter or indirectly through another layer. For example, a transparent electrode such as ITO or a protective film may be formed on the color filter, and a convex spacer may be formed thereon, or a protective film and a transparent electrode may be formed on the color filter in this order, and the transparent electrode A convex spacer may be formed on the top.
The alignment film 10 is provided on the inner surface side of the color filter so as to cover the display portion including the colored layer 7 and the non-display portion including the light shielding layer 6 and the columnar spacer 12. The alignment film can be formed by applying a coating solution containing a resin such as a polyimide resin by a known method such as spin coating, drying, curing with heat or light as necessary, and then rubbing.

  When the color filter 103 (display side substrate) thus obtained and the TFT array substrate (liquid crystal drive side substrate) are opposed to each other, and the inner peripheral side peripheral portions of both the substrates are bonded with a sealant, the both substrates are separated by a predetermined distance. Bonding is performed with the cell gap maintained. An active matrix color liquid crystal display device belonging to the liquid crystal panel can be obtained by filling the liquid crystal in the gap between the substrates and sealing the liquid crystal.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same function and effect. Are included in the technical scope.

<Selection of yellow or orange pigment>
(1) Preparation of test membrane Yellow or orange pigment 30 parts by weight, pigment dispersant 15 parts by weight, propylene glycol monomethyl ether acetate 300 parts by weight were mixed and dispersed to prepare a yellow or orange pigment dispersion. . About dispersion | distribution, time was adjusted suitably so that it might fully disperse | distribute with each pigment. On the other hand, the copolymer reaction solution obtained in the following Production Example 1 as a methyl methacrylate / methacrylic acid copolymer (molar ratio 9/1) having a weight average molecular weight of 7000 to 15000 is a copolymer solution having a solid content of 40%. 112.5 parts by weight as it was and mixed with 345 parts by weight of the yellow or orange pigment dispersion described above. The mixture obtained as described above was used as a test film-forming resin composition.
The test film-forming resin composition was applied onto a 0.7 mm thick glass substrate (NH Techno Glass Co., Ltd., NA35) by spin coating. Then, it heat-dried for 3 minutes on an 80 degreeC hotplate. The film thickness after drying was adjusted so that x = 0.450 in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source. In addition, when it is difficult to apply the resin composition on the glass, the coating suitability can be improved by adding a small amount of a surfactant such as MegaFac (Dainippon Ink Chemical Co., Ltd.).

(2) Light transmittance measurement Using Olympus microspectrophotometer OSP-SP200, the light transmittance value of the same glass substrate as the glass substrate on which the test film forming resin composition is applied is obtained as 100%. The transmission spectrum of a C light source in the test film was measured, and the light transmittance was calculated.

<Production Example 1>
150 parts by weight of PGMEA was placed in a four-necked flask equipped with a stirrer and a nitrogen introduction tube, and heated to 100 ° C. with a mantle heater. Then, 90 parts by weight of methyl methacrylate (MMA), 10 parts by weight of methacrylic acid (MAA), 4.0 parts by weight of n-dodecyl mercaptan, and 1.60 parts by weight of AIBN were added from the dropping funnel over 1.5 hours. And dripped. During the dropping, the temperature in the flask was adjusted to 100 ± 1 ° C. After completion of dropping, 0.3 part by weight of AIBN was added and reacted at 100 ° C. for 2 hours to obtain a colorless and transparent MMA / MAA copolymer solution. When the molecular weight was confirmed by GPC measurement using polystyrene as a standard after completion of the reaction, the weight average molecular weight of the obtained polymer was 7,000. Moreover, it was 40.0% when solid content was measured by heating in 150 degreeC oven for 2 hours.

<Production Example 2>
(1) Preparation of red pigment dispersion for color filter From 10 parts by weight of finer pigment (CI Pigment Red 254 (PR254) primary particles 15-60 nm), from quaternary ammonium salt of dimethylaminoethyl (meth) acrylate 10 parts by weight of a pigment dispersant (BYK2000, manufactured by BYK Chemie, solid content 40% by weight), which is a polymer containing a derived repeating unit, and an alkali-soluble resin (styrene / benzyl methacrylate / acrylic acid / 2-hydroxymethyl acrylate copolymer) (Molar ratio 30/40/10/20, acid value: 70 mg KOH / g, molecular weight 6000) 4 parts by weight and solvent propylene glycol monomethyl ether acetate 76 parts by weight are mixed, and 1 mm with 2 mm zirconia beads in a paint shaker And 0.1mm zirconia beads The mixture was dispersed for 6 hours to obtain a preliminarily prepared pigment dispersion A. The bead filling rate in the vessel at the time of dispersion was 50%, and the dispersed particle diameter of the pigment particles was 1000 with propylene glycol monomethyl ether acetate. Double-diluted, and measured by a dynamic light scattering method using a nanotrack particle size distribution analyzer UPA-EX150 manufactured by Nikkiso Co., Ltd. The dispersed particle size of the above-prepared pigment dispersion A is a volume average particle size. Was 43 nm.

  A pigment which is a polymer containing a repeating unit derived from a quaternary ammonium salt of dimethylaminoethyl (meth) acrylate with respect to 10 parts by weight of a finer pigment (CI Pigment Red 177 (PR177) primary particles 10 to 50 nm) 10 parts by weight of a dispersant (BYK2000, manufactured by Big Chemie, solid content 40% by weight) and an alkali-soluble resin (styrene / benzyl methacrylate / acrylic acid / 2-hydroxymethyl acrylate copolymer (molar ratio 30/40/10/20, acid) (Value: 70 mg KOH / g, molecular weight 6000) 4 parts by weight and 76 parts by weight of solvent propylene glycol monomethyl ether acetate are mixed and dispersed in a paint shaker for 1 hour with 2 mm zirconia beads and further for 5 hours with 0.1 mm zirconia beads. A pre-prepared pigment dispersion B was obtained. In addition, the bead filling rate in the vessel at the time of dispersion was set to 50%, and the dispersion particle diameter of the pigment particles was measured in the same manner as in the above-prepared pigment dispersion liquid A. The volume average particle size was 41 nm.

  In the selection of the yellow or orange pigment, the light transmittance of the test film was 90% or more in the wavelength region of 560 nm to 640 nm. I. Pigment Yellow 150 refined pigment (CI Pigment Yellow 150 (PY150) primary particles 10 to 50 nm) 10 parts by weight includes a repeating unit derived from a quaternary ammonium salt of dimethylaminoethyl (meth) acrylate. 10 parts by weight of pigment dispersant (BYK2000, manufactured by BYK Chemie, solid content 40% by weight) and alkali-soluble resin (styrene / benzyl methacrylate / acrylic acid / 2-hydroxymethyl acrylate copolymer (molar ratio 30/40/10) / 20, acid value: 70 mg KOH / g, molecular weight 6000) 4 parts by weight and solvent propylene glycol monomethyl ether acetate 76 parts by weight are mixed with a paint shaker for 2 hours with 2 mm zirconia beads, and further with 0.1 mm zirconia beads. Dispersed for 3 hours, A pre-prepared pigment dispersion C was obtained, and the bead filling rate in the vessel at the time of dispersion was 50%, and the dispersion particle size of the pigment particles was measured in the same manner as in the pre-prepared pigment dispersion A. The dispersed particle diameter of the pigment dispersion C was 48 nm in volume average particle diameter.

  In the selection of the yellow or orange pigment, the light transmittance of the test film was less than 90% in the wavelength region of 560 nm to 640 nm. I. Polymer containing repeating unit derived from quaternary ammonium salt of dimethylaminoethyl (meth) acrylate with respect to 10 parts by weight of Pigment Yellow 138 fine pigment (CI Pigment Yellow 138 (PY138) primary particles 10-70 nm) 10 parts by weight of a pigment dispersant (BYK2000, manufactured by Big Chemie, solid content 40% by weight) and an alkali-soluble resin (styrene / benzyl methacrylate / acrylic acid / 2-hydroxymethyl acrylate copolymer (molar ratio 30/40/10 / 20, acid value: 70 mg KOH / g, molecular weight 6000) 4 parts by weight and solvent propylene glycol monomethyl ether acetate 76 parts by weight are mixed with a paint shaker for 1 hour with 2 mm zirconia beads, and further with 4 with 0.1 mm zirconia beads. Time dispersion A prepared pigment dispersion D was obtained, and the bead filling rate in the vessel at the time of dispersion was set to 50%, and the dispersion particle diameter of the pigment particles was measured in the same manner as in the preliminarily prepared pigment dispersion A. The dispersed particle diameter of the pigment dispersion D was 59 nm in volume average particle diameter.

  A pigment dispersion which is a polymer containing a repeating unit derived from a quaternary ammonium salt of dimethylaminoethyl (meth) acrylate with respect to 10 parts by weight of a finer pigment (CI Pigment Red (PR242) primary particles 10 to 50 nm) 10 parts by weight of agent (BYK2000, manufactured by Big Chemie, solid content 40% by weight) and alkali-soluble resin (styrene / benzyl methacrylate / acrylic acid / 2-hydroxymethyl acrylate copolymer (molar ratio 30/40/10/20, acid value) : 70 mg KOH / g, molecular weight 6000) 4 parts by weight and solvent propylene glycol monomethyl ether acetate 76 parts by weight are mixed with a paint shaker for 1 hour with 2 mm zirconia beads, and further dispersed with 0.1 mm zirconia beads for 1.5 hours. As a result, a preliminarily prepared pigment dispersion E was obtained. The bead filling rate in the vessel at the time of dispersion was 25%, and the dispersion particle diameter of the pigment particles was measured in the same manner as in the above-prepared pigment dispersion liquid A. The volume average particle size was 47 nm.

<Example 1>
The pre-prepared pigment dispersion A, the pre-prepared pigment dispersion B and the pre-prepared pigment dispersion C are mixed at a ratio of 20 parts by weight, 40 parts by weight and 40 parts by weight, respectively, and the red pigment dispersion according to the present invention is prepared. (Pigment dispersion F) was prepared. When the dispersed particle diameter of the pigment particles was measured in the same manner as the above-prepared pigment dispersion liquid A, the volume average particle diameter of the red pigment dispersion liquid (pigment dispersion liquid F) according to the present invention was 44 nm. .
Further, the pigment particles having a dispersed particle diameter of 5 nm or more and less than 100 nm were 99% by volume or more of the total pigment particles. Furthermore, pigment particles of 5 nm or more and less than 30 nm were 11% by volume of all pigment particles, pigment particles of 30 nm or more and less than 61 nm were 72% by volume, and pigment particles of 61 nm or more and less than 100 nm were 17% by volume. Further, the particle size was 45 nm when the cumulative particle size distribution was 50% by volume in all particles.

(2) Preparation of red photosensitive resin composition for color filter 30 parts by weight of the following binder composition was added to 40 parts by weight of the red pigment dispersion liquid (pigment dispersion liquid F) obtained in Example 1 and pressurized. Filtration was performed to obtain red photosensitive resin compositions for color filters of Example 1, respectively.
<Binder composition>
Alkali-soluble resin (styrene / benzyl methacrylate / acrylic acid / 2-hydroxymethyl acrylate copolymer (molar ratio 30/40/10/20, acid value: 70 mg KOH / g, molecular weight 6000)): 20 parts by weight Acrylate monomer (KAYARAD DPHA, manufactured by Nippon Kayaku): 10 parts by weight, tetrafunctional acrylate monomer (Aronix M450, manufactured by Toagosei): 5 parts by weight, photopolymerization initiator (2-methyl-1 [4- (methylthio) phenyl ] -2-Morifolinopropan-1-one (trade name Irgacure 907, manufactured by Ciba Specialty Chemicals): 3 parts by weight / photopolymerization initiator (2-benzyl-2-dimethylamino-1- (4-morpholino) Phenyl) -1-butanone (trade name Irgacure 369, Ciba Specialty Chemi Ltd. LUZ)): 3 parts by weight photosensitizer (4,4'-dimethylamino benzophenone): 1.5 parts by weight Solvent (propylene glycol monomethyl ether acetate): 40 parts by weight

(3) Evaluation of red photosensitive resin composition for color filter (i) Particle size distribution The dispersed particle size of pigment particles was obtained by diluting the red photosensitive resin composition for color filter 1000 times with propylene glycol monomethyl ether acetate. The measurement was performed at 23 ° C. by a dynamic light scattering method using a Nanotrac particle size distribution analyzer UPA-EX150 manufactured by the company.
As for the dispersed particle diameter of the photosensitive resin composition of Example 1, the volume average particle diameter was 44 nm.
Moreover, the pigment particles of 5 nm or more and less than 100 nm were 99% by volume of the total pigment particles. Further, pigment particles of 5 nm or more and less than 30 nm were 10% by volume of all pigment particles, pigment particles of 30 nm or more and less than 61 nm were 74% by volume, and pigment particles of 61 nm or more and less than 100 nm were 15% by volume. Further, the particle size was 45 nm when the cumulative particle size distribution was 50% by volume in all particles.

(Ii) Contrast The photosensitive resin composition for color filters was applied by spin coating on a glass substrate (NH Techno Glass Co., Ltd., NA35) having a thickness of 0.7 mm.
Then, it heat-dried for 3 minutes on an 80 degreeC hotplate. A cured film (colored layer) was obtained by exposure (60 mJ) using a small aligner. The film thickness after drying and curing was adjusted so that the target chromaticity x = 0.650.
The prepared cured film was subjected to cross-sectional TEM observation with a transmission electron microscope (JEM-200CX, JEOL Ltd., acceleration voltage 100 kV) obtained by thinning the sample in the cross-sectional direction using FIB (focused ion beam apparatus) (FB-2000A manufactured by Hitachi). The particle size was measured.

Luminance was measured using a contrast measuring device CT-1 manufactured by Aisaka Electric Co., Ltd., light source: F10 lamp between cold cathodes, luminance meter: LS-100 manufactured by Konica Minolta, and spectral luminance meter: CS-1000T manufactured by Konica Minolta. . The contrast can be derived from the following formula using the measured luminance value.
Contrast = parallel luminance (cd / m ² ) / orthogonal luminance (cd / m ² )

  As a result, the contrast value of the red photosensitive resin composition for a color filter of Example 1 was 5955. In addition, particles having a size of 100 nm or more were not observed in a field of view of 100000 times by cross-sectional TEM observation.

<Comparative Example 1>
Only the preliminarily prepared pigment dispersion A (CI Pigment Red 254) was used as the red pigment dispersion.
A red photosensitive resin composition for a color filter was prepared using the red pigment dispersion in the same manner as in Example 1.
About the obtained red photosensitive resin composition for color filters, the particle size distribution and the contrast were evaluated in the same manner as in Example 1.

(I) Particle size distribution The dispersed particle size of the photosensitive resin composition of Comparative Example 1 was 43 nm in volume average particle size.
Further, the pigment particles having a diameter of 5 nm or more and less than 100 nm were 100% by volume of the total pigment particles. In addition, pigment particles of 5 nm or more and less than 30 nm were 15% by volume of all pigment particles, pigment particles of 30 nm or more and less than 61 nm were 76% by volume, and pigment particles of 61 nm or more and less than 100 nm were 9% by volume. Further, the particle size was 43 nm when the cumulative particle size distribution was 50% by volume in all particles.

(Ii) Contrast The contrast value of the cured film adjusted to a film thickness of x = 0.650 using the red photosensitive resin composition for a color filter of Comparative Example 1 was 3122. In addition, particles having a size of 100 nm or more were not observed in a field of view of 100000 times by cross-sectional TEM observation.

<Comparative Example 2>
Only the pre-prepared pigment dispersion A (CI pigment red 254) and the pre-prepared pigment dispersion B (CI pigment red 177) were used as red pigment dispersions. The pre-prepared pigment dispersion A and the pre-prepared pigment dispersion B were mixed at a ratio of 50 parts by weight to prepare a red pigment dispersion (pigment dispersion G). When the dispersed particle diameter of the pigment particles was measured in the same manner as the above-prepared pigment dispersion liquid A, the volume average particle diameter of the red pigment dispersion liquid (pigment dispersion liquid G) was 43 nm.
A red photosensitive resin composition for a color filter was prepared using the red pigment dispersion in the same manner as in Example 1.
About the obtained red photosensitive resin composition for color filters, the particle size distribution and the contrast were evaluated in the same manner as in Example 1.

(I) Particle size distribution As for the dispersed particle size of the photosensitive resin composition of Comparative Example 2, the volume average particle size was 44 nm.
Further, the pigment particles having a diameter of 5 nm or more and less than 100 nm were 100% by volume of the total pigment particles. Further, the pigment particles of 5 nm or more and less than 30 nm were 15% by volume of the total pigment particles, the pigment particles of 30 nm or more and less than 61 nm were 55% by volume, and the pigment particles of 61 nm or more and less than 100 nm were 30% by volume. Furthermore, the particle size was 46 nm when the cumulative particle size distribution was 50% by volume in all particles.

(Ii) Contrast The contrast value of the cured film adjusted to a film thickness of x = 0.650 using the red photosensitive resin composition for a color filter of Comparative Example 2 was 5397. In addition, particles having a size of 100 nm or more were not observed in a field of view of 100000 times by cross-sectional TEM observation.

<Comparative Example 3>
Pre-prepared pigment dispersion A (CI Pigment Red 254), Pre-prepared Pigment Dispersion B (CI Pigment Red 177) and Pre-prepared Pigment Dispersion D (CI Pigment Yellow 138) were 20 parts by weight, 40 parts by weight and 40 parts by weight, respectively. Parts were mixed to give a red pigment dispersion.
A red photosensitive resin composition for a color filter was prepared using the red pigment dispersion in the same manner as in Example 1.
About the obtained red photosensitive resin composition for color filters, the particle size distribution and the contrast were evaluated in the same manner as in Example 1.

(I) Particle size distribution The volume average particle size of the dispersed particle size of the photosensitive resin composition of Comparative Example 3 was 54 nm.
In addition, pigment particles of 5 nm or more and less than 100 nm were 97% by volume of the total pigment particles. Further, pigment particles of 5 nm or more and less than 30 nm were 6% by volume of all pigment particles, pigment particles of 30 nm or more and less than 61 nm were 76% by volume, and pigment particles of 61 nm or more and less than 100 nm were 15% by volume. Further, the particle size was 55 nm when the cumulative particle size distribution was 50% by volume in all particles.

(Ii) Contrast The contrast value of the cured film adjusted to a film thickness of x = 0.650 using the red photosensitive resin composition for a color filter of Comparative Example 3 was 5045. In addition, particles having a size of 100 nm or more were not observed in a field of view of 100000 times by cross-sectional TEM observation.

<Example 2>
Pre-prepared pigment dispersion E (CI Pigment Red 242), Pre-prepared Pigment Dispersion B (CI Pigment Red 177) and Pre-prepared Pigment Dispersion C (CI Pigment Yellow 150) were 30 parts by weight, 30 parts by weight and 30 parts by weight, respectively. A red pigment dispersion was prepared by mixing parts by part.
A red photosensitive resin composition for a color filter was prepared using the red pigment dispersion in the same manner as in Example 1.
About the obtained red photosensitive resin composition for color filters, the particle size distribution and the contrast were evaluated in the same manner as in Example 1.

(I) Particle size distribution The dispersed particle size of the photosensitive resin composition of Comparative Example 1 was 42 nm in volume average particle size.
Further, the pigment particles having a diameter of 5 nm or more and less than 100 nm were 100% by volume of the total pigment particles. Further, pigment particles of 5 nm or more and less than 30 nm were 18% by volume of all pigment particles, pigment particles of 30 nm or more and less than 61 nm were 68% by volume, and pigment particles of 61 nm or more and less than 100 nm were 14% by volume. Further, the particle size was 43 nm when the cumulative particle size distribution was 50% by volume in all particles.

(Ii) Contrast The contrast value of the cured film adjusted to a film thickness of x = 0.650 using the red photosensitive resin composition for a color filter of Comparative Example 1 was 6367. In addition, particles having a size of 100 nm or more were not observed in a field of view of 100000 times by cross-sectional TEM observation.

<Comparative Example 5>
Only the pre-prepared pigment dispersion E (CI Pigment Red 242) was used as the red pigment dispersion.
A red photosensitive resin composition for a color filter was prepared using the red pigment dispersion in the same manner as in Example 1.
About the obtained red photosensitive resin composition for color filters, the particle size distribution and the contrast were evaluated in the same manner as in Example 1.

(I) Particle size distribution The dispersed particle size of the photosensitive resin composition of Comparative Example 1 was 43 nm in volume average particle size.
Further, the pigment particles having a diameter of 5 nm or more and less than 100 nm were 100% by volume of the total pigment particles. Further, the pigment particles of 5 nm or more and less than 30 nm were 17% by volume of the total pigment particles, the pigment particles of 30 nm or more and less than 61 nm were 69% by volume, and the pigment particles of 61 nm or more and less than 100 nm were 14% by volume. Further, the particle size was 43 nm when the cumulative particle size distribution was 50% by volume in all particles.

(Ii) Contrast The contrast value of the cured film adjusted to a film thickness of x = 0.650 using the red photosensitive resin composition for a color filter of Comparative Example 1 was 5280. In addition, particles having a size of 100 nm or more were not observed in a field of view of 100000 times by cross-sectional TEM observation.

<Comparative Example 6>
Only 40 parts by weight and 40 parts by weight of Preliminary Pigment Dispersion E (CI Pigment Red 242) and Preparative Pigment Dispersion B (CI Pigment Red 177) were mixed to give a red pigment dispersion.
A red photosensitive resin composition for a color filter was prepared using the red pigment dispersion in the same manner as in Example 1.
About the obtained red photosensitive resin composition for color filters, the particle size distribution and the contrast were evaluated in the same manner as in Example 1.

(I) Particle size distribution The dispersed particle size of the photosensitive resin composition of Comparative Example 1 was 43 nm in volume average particle size.
Further, the pigment particles having a diameter of 5 nm or more and less than 100 nm were 100% by volume of the total pigment particles. In addition, pigment particles of 5 nm or more and less than 30 nm were 13% by volume of all pigment particles, pigment particles of 30 nm or more and less than 61 nm were 68% by volume, and pigment particles of 61 nm or more and less than 100 nm were 11% by volume. Further, the particle size was 43 nm when the cumulative particle size distribution was 50% by volume in all particles.

(Ii) Contrast The contrast value of the cured film adjusted to a film thickness of x = 0.650 using the red photosensitive resin composition for a color filter of Comparative Example 1 was 5863. In addition, particles having a size of 100 nm or more were not observed in a field of view of 100000 times by cross-sectional TEM observation.

<Example 3>
Pre-prepared pigment dispersion E (CI pigment red 242), pre-prepared pigment dispersion B (CI pigment red 177) and pre-prepared pigment dispersion C (CI pigment yellow 150) were 40 parts by weight, 40 parts by weight and 20 parts by weight, respectively. A red pigment dispersion was prepared by mixing parts by part.
A red photosensitive resin composition for a color filter was prepared using the red pigment dispersion in the same manner as in Example 1.
About the obtained red photosensitive resin composition for color filters, the particle size distribution and the contrast were evaluated in the same manner as in Example 1.

(I) Particle size distribution The dispersed particle size of the photosensitive resin composition of Comparative Example 1 was 43 nm in volume average particle size.
Further, the pigment particles having a diameter of 5 nm or more and less than 100 nm were 100% by volume of the total pigment particles. Further, pigment particles of 5 nm or more and less than 30 nm were 12% by volume of all pigment particles, pigment particles of 30 nm or more and less than 61 nm were 68% by volume, and pigment particles of 61 nm or more and less than 100 nm were 20% by volume. Further, the particle size was 45 nm when the cumulative particle size distribution was 50% by volume in all particles.

(Ii) Contrast The contrast value of the cured film adjusted to a film thickness of x = 0.650 using the red photosensitive resin composition for a color filter of Comparative Example 1 was 6294. In addition, particles having a size of 100 nm or more were not observed in a field of view of 100000 times by cross-sectional TEM observation.

<Result>
In FIG. 3, the spectral luminance at the time of the polarizing plate parallel of Example 1 of this invention and Comparative Example 2 is shown. In FIG. 4, the spectral luminance at the time of the polarizing plate orthogonal of Example 1 of this invention and Comparative Example 2 is shown. FIG. 5 shows the spectral luminance when the polarizing plates of Example 2 and Comparative Example 6 of the present invention are parallel. In FIG. 6, the spectral luminance at the time of the polarizing plate orthogonal of Example 2 of this invention and Comparative Example 6 is shown.
From FIG. 3 to FIG. 6, in Examples 1 and 2 to which a specific yellow pigment was added so that the average dispersed particle diameter was in the specific range of the present invention, the orthogonality of the bright line in the wavelength range of 560 to 640 nm was obtained. It was clarified that the contrast was drastically improved because the brightness decreased and the parallel brightness increased.

DESCRIPTION OF SYMBOLS 1 Color filter 2 Electrode substrate 3 Gap part 4 Sealing material 5 Transparent substrate 6 Black matrix layer 7 (7R, 7G, 7B) Colored layer 8 Protective film 9 Transparent electrode film 10 Orientation film 11 Pearl 12 Columnar spacer 101, 102 Color liquid crystal display Device 103 Color filter

Claims (20)

A red pigment dispersion for a color filter comprising a red pigment, a yellow or orange pigment having a light transmittance of 90% or more in the wavelength range of 560 nm to 640 nm, a pigment dispersant, and a solvent. A red pigment dispersion for a color filter, wherein the dispersed pigment particles have an average dispersed particle size of 15 to 80 nm.
[Test membrane]
30 parts by weight of the yellow or orange pigment and the pigment dispersant 7.5 so that x = 0.450 in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source A resin composition for test membranes comprising 24 to 24 parts by weight, 36 to 52.5 parts by weight of a methyl methacrylate / methacrylic acid copolymer (molar ratio 9/1) having a weight average molecular weight of 7000 to 15000 and 300 to 400 parts by weight of the solvent. An object is applied on an alkali-free glass substrate and dried to form a test film.   The red pigment dispersion for a color filter according to claim 1, wherein the yellow or orange pigment is 5 to 50 wt% in the total pigment.   The red pigment is two or more selected from the group consisting of CI Pigment Red 254, CI Pigment Red 177, CI Pigment Red 254, CI Pigment Red 255, and Pigment Red 242. 2. A red pigment dispersion for a color filter as described in 2.   The yellow or orange pigment is CI pigment yellow 150 or a derivative pigment thereof, CI pigment yellow 185, CI pigment yellow 17, CI pigment yellow 138, CI pigment yellow 139, CI pigment yellow 173, CI pigment yellow 117, CI pigment orange The red pigment dispersion for a color filter according to claim 1, wherein the dispersion is one or more selected from the group consisting of 66, CI Pigment Orange 68, and CI Pigment Orange 69.   The red pigment is CI Pigment Red 254 and / or Pigment Red 242 and CI Pigment Red 177, and the yellow or orange pigment is CI Pigment Yellow 150 or a derivative pigment thereof. 4. A red pigment dispersion for color filters according to 4.   The red pigment for a color filter according to any one of claims 1 to 5, wherein in the dispersed pigment particles, the pigment particles having a dispersed particle diameter of 5 nm or more and less than 100 nm are 99% or more of the total pigment particles. Dispersion.   A polymer further comprising a pigment dispersant, wherein the pigment dispersant comprises repeating units derived from dimethylaminoethyl (meth) acrylate and a tertiary or quaternary ammonium salt of dimethylaminoethyl (meth) acrylate, and / or The red pigment dispersion for a color filter according to claim 1, wherein the red pigment dispersion is a polyallylamine derivative.   The solvent according to any one of claims 1 to 7, wherein the solvent is at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, butyl carbitol acetate, and cyclohexanone. Red pigment dispersion for color filters. For color filters including a red pigment, a yellow or orange pigment having a light transmittance of 90% or more in the wavelength range of 560 nm to 640 nm, a pigment dispersant, a photosensitive binder component, and a solvent. A red photosensitive resin composition for a color filter, which is a red photosensitive resin composition, wherein an average dispersed particle diameter of dispersed pigment particles is 15 to 80 nm.
[Test membrane]
30 parts by weight of the yellow or orange pigment and the pigment dispersant 7.5 so that x = 0.450 in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source A resin composition for test membranes comprising 24 to 24 parts by weight, 36 to 52.5 parts by weight of a methyl methacrylate / methacrylic acid copolymer (molar ratio 9/1) having a weight average molecular weight of 7000 to 15000 and 300 to 400 parts by weight of the solvent. An object is applied on an alkali-free glass substrate and dried to form a test film.   The red photosensitive resin composition for a color filter according to claim 9, wherein the yellow or orange pigment is 5 to 50% by weight in the total pigment.   The said red pigment is 1 or more types selected from the group which consists of CI pigment red 254, CI pigment red 177, CI pigment red 255, and CI pigment red 242, The Claim 9 or 10 characterized by the above-mentioned. Red photosensitive resin composition for color filters.   The yellow or orange pigment is CI pigment yellow 150 or a derivative pigment thereof, CI pigment yellow 185, CI pigment yellow 17, CI pigment yellow 138, CI pigment yellow 139, CI pigment yellow 173, CI pigment yellow 117, CI pigment orange 66 The red photosensitive resin composition for a color filter according to claim 9, wherein the composition is one or more selected from the group consisting of CI Pigment Orange 68 and CI Pigment Orange 69.   The red pigment is CI pigment red 254 and / or pigment red 242 and CI pigment red 177, and the yellow or orange pigment is CI pigment yellow 150 or a derivative pigment thereof. The red photosensitive resin composition for color filters according to 12.   14. The red light-sensitive color filter for a color filter according to claim 9, wherein in the dispersed pigment particles, the pigment particles having a dispersed particle diameter of 5 nm or more and less than 100 nm are 99% or more of all pigment particles. Resin composition.   Further, a polymer containing a pigment dispersant, wherein the pigment dispersant contains a repeating unit derived from dimethylaminoethyl (meth) acrylate and / or a tertiary or quaternary ammonium salt of dimethylaminoethyl (meth) acrylate. The red photosensitive resin composition for a color filter according to any one of claims 9 to 14, wherein the composition is a polyallylamine derivative.   16. The solvent according to claim 9, wherein the solvent is at least one selected from the group consisting of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, butyl carbitol acetate, and cyclohexanone. Red photosensitive resin composition for color filters.   When a cured film of a resin composition satisfying 0.645 <x <0.655 is formed in the chromaticity coordinates (x, y) in the XYZ color chromaticity diagram measured using a C light source, the resin composition The ratio of the luminance that is transmitted when the cured film of the product is sandwiched between two polarizing plates that are orthogonal or parallel (brightness when the polarizing plates are parallel / luminance when the polarizing plates are orthogonal) is 5500 or more. The red photosensitive resin composition for a color filter according to any one of claims 9 to 16, wherein:   The color filter provided with the colored layer formed using the red photosensitive resin composition for color filters in any one of the said Claims 9 thru | or 17.   The ratio of luminance that is transmitted when the color filter is sandwiched between two polarizing plates that are orthogonal or parallel (luminance when the polarizing plates are parallel / luminance when the polarizing plates are orthogonal) is 5500 or more. The color filter according to claim 18, wherein:   A display device comprising the color filter according to claim 18 or 19.