JP2008145868A - Color filter and liquid crystal display device. - Google Patents

Abstract

A color filter having good chromaticity and capable of realizing high color purity, high contrast, and a wide viewing angle even when used in a liquid crystal display device having a large screen.
A color filter having at least three colored pixels of R, G, and B, wherein the chromaticity x of the R pixel in an XYZ color system under a C light source is 0. 58 to 0.68 and chromaticity y of 0.31 to 0.35; G pixel chromaticity x of 0.27 to 0.35 and chromaticity y of 0.54 to 0.62; or B pixel The chromaticity x is 0.13 to 0.16 or less and the chromaticity y is 0.05 to 0.15, and the Rth at the wavelength of each RGB pixel (R: 650 nm, G: 550 nm, B: 450 nm) is Each of the color filters is -50 nm to 50 nm and has a contrast of 3500 or more.
[Selection figure] None

Description

  The present invention relates to a color filter that can be used in a liquid crystal display device such as a notebook computer or a television monitor, in particular, a color filter that can be suitably used in a large-screen liquid crystal display device, and a liquid crystal display device using the color filter. .

  In general, in a liquid crystal display, light that has passed through a color filter is directly colored into the color of each pixel constituting the color filter, and the light of these colors is combined to form a color image. At present, a color image is formed with pixels of three colors of RGB. The development of technology for increasing the screen size and resolution of liquid crystal displays has been advancing, and its applications have been expanded from displays for notebook computers to monitors for desktop computers and further to TV monitors. Under such circumstances, color filters used in liquid crystal displays are required to have high quality such as high color purity, high contrast, and wide viewing angle.

  On the other hand, LCDs having excellent contrast viewing angle characteristics have been proposed by using optical compensation sheets having various optical characteristics. In particular, the three modes of OCB, VA, and IPS have wide contrast viewing angle characteristics in all directions, and are already widely used in homes as televisions, particularly as wide viewing angle modes. Furthermore, large-sized displays exceeding 30 inches have recently appeared.

  By the way, the contrast viewing angle characteristic of the LCD can be improved by using the optical compensation sheet, but on the other hand, the improvement effect on the color viewing angle characteristic is not sufficient. It is an important issue. The color viewing angle characteristic of the LCD is derived from the fact that the wavelength changes in three typical colors of R, G, and B, so that the change due to the phase difference of the polarization is different even with the same phase difference. In order to improve the color viewing angle characteristics, the wavelength dependence of the birefringence of the optically anisotropic material used in the LCD, that is, the birefringence wavelength dispersion is optimized for each of R, G, and B. It is. In the current LCD, the birefringence wavelength dispersion of the liquid crystal molecules in the liquid crystal cell used for ON / OFF display and the birefringence wavelength dispersion of the optical compensation sheet cannot be easily controlled. Not reached.

  As a wide viewing angle polarizing film that prevents light leakage when viewed obliquely and has almost no color in the leaked light, in-plane retardation of wavelengths 450 nm and 550 nm satisfies a predetermined relationship with the polarizing film. A wide viewing angle polarizing film in which a single layer oriented film is laminated has been proposed (Patent Document 1). Patent Document 1 describes that a modified polycarbonate can be used as a material for a single-layer oriented film used in this wide-viewing-angle polarizing film, and in the examples, a single layer is actually used using a polycarbonate resin. An oriented film is produced. By using this single-layer oriented film for a λ / 4 plate in a reflective liquid crystal display device or an optical compensation sheet in a VA mode, color viewing angle characteristics can be improved. However, the modified polycarbonate film is not yet widely used for LCDs because not only the raw material itself is expensive, but also non-uniformity in optical properties such as bowing occurs in stretching used in the production process.

On the other hand, although the principle is the same as that of contrast viewing angle compensation by an optical compensation sheet, a method of independently compensating for the three colors of R, G, and B has also been proposed. For example, Patent Document 2 balances the transmitted light intensity for each wavelength by matching the retardation in the transparent protective film provided on the R, G, and B color filters with the retardation in the liquid crystal layer. This prevents deterioration of display characteristics when the element is viewed from a direction inclined from the front.
By the way, optimizing the retardation necessary for optical compensation for each color of R, G, and B is realized mainly by a method of patterning a retardation plate together with a color filter or the like in a liquid crystal cell. However, in order to pattern the retardation plate in the liquid crystal cell, for example, in the cell, formation of an alignment film layer, rubbing treatment, application of a polymerizable liquid crystal composition, alignment, fixation, formation of a resist layer, etching Complicated operations such as treatment and stripping / removing of the resist layer are required, and therefore it is difficult to form an optically anisotropic layer having optically uniform retardation characteristics. In addition, the phase difference of the retardation plate may change before and after etching due to heat and photoresist solvent generated when forming a resist pattern.

In addition, as a color filter that contributes to improving the viewing angle dependency, any one of a red pixel, a green pixel, and a blue pixel includes at least a resin and a retardation-reducing particle, and an average refractive index is Colored polymer thin films having a value of 1.60 or more and 1.90 or less and an absolute value of birefringence of 0.01 or less are proposed (Patent Documents 3 and 4). These color filters improve the viewing angle characteristics by reducing the retardation of the color filters. However, since the retardation-reducing particles are added, it can contribute to the improvement of the viewing angle, but it is difficult to achieve both high color purity and high contrast of the color filter.
Japanese Patent Laid-Open No. 5-196931 JP 2002-221622 A JP 2000-136253 A JP 2000-187114 A

  The object of the present invention is to have high chromaticity and high color purity, high contrast and wide viewing angle even when used for large-screen liquid crystal display devices such as notebook computer displays and TV monitors. And a liquid crystal display device using the color filter.

The above-mentioned subject is achieved by the following invention. In other words, the present invention
[1] A color filter having at least three colored pixels of R, G, and B, and the chromaticity x in the XYZ color system under the C light source of the R pixel of the color filter is 0.58 to 0.68, chromaticity y is 0.31 to 0.35, Rth (retardation in the thickness direction) at a wavelength of 650 nm is −50 nm to 50 nm, and contrast is 3500 or more. Color filter to be used.
[2] A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the G pixel of the color filter in the XYZ color system under the C light source is 0.27 to A color filter having 0.35, a chromaticity y of 0.54 to 0.62, an Rth of -50 nm to 50 nm at a wavelength of 550 nm, and a contrast of 3500 or more.
[3] A color filter having at least three colored pixels of R, G, and B, and the chromaticity x in the XYZ color system under the C light source of the B pixel of the color filter is 0.13 to A color filter characterized by 0.16, chromaticity y of 0.05 to 0.15, Rth at a wavelength of 450 nm of -50 nm to 50 nm, and contrast of 3500 or more.
[4] A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the R pixel in the XYZ color system under the C light source is 0.58. ˜0.68 and chromaticity y of 0.31 to 0.35, G pixel chromaticity x of 0.27 to 0.35 and chromaticity y of 0.54 to 0.62, and B pixel Chromaticity x is 0.13 to 0.16 and chromaticity y is 0.05 to 0.15. Rth of R pixel at wavelength of 650 nm, Rth of G pixel at wavelength of 550 nm, Rth of B pixel at wavelength of 450 nm Each of the color filters is -50 nm to 50 nm, and the contrast is 3500 or more, The color filter according to any one of [1] to [3].
[5] A colored photosensitive resin in which at least one colored pixel of R, G, and B includes at least (A) a colorant, (B) a retardation control agent, (C) a monomer, and (D) a photopolymerization initiator. The color filter according to any one of [1] to [4], wherein the color filter is a colored pixel formed from a composition.
[6] A liquid crystal display device comprising the color filter according to any one of [1] to [5].

  According to the present invention, it has good chromaticity, and particularly when used in a large-screen liquid crystal display device such as a notebook computer display or a TV monitor, high color purity, high contrast and a wide viewing angle. And a liquid crystal display device using the color filter can be provided.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value.
[Color filter]
The color filter of the present invention is a color filter that has at least RGB colored pixels, and each colored pixel satisfies the conditions described in the following (1) to (3), preferably described in (4): This is a color filter that satisfies the condition, that is, the colored pixels of three colors of RGB satisfy a predetermined condition.
(1) A color filter having at least three colored pixels of R, G, and B, and the chromaticity x in the XYZ color system under the C light source of the R pixel of the color filter is 0.58 to 0.68, chromaticity y is 0.31 to 0.35, Rth (retardation in the thickness direction) at a wavelength of 650 nm is −50 nm to 50 nm, and contrast is 3500 or more. Color filter.
(2) A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the G pixel of the color filter in the XYZ color system under the C light source is 0.27 to A color filter having 0.35, a y pixel of 0.54 to 0.62, an Rth of -50 nm to 50 nm at a wavelength of 550 nm, and a contrast of 3500 or more.
(3) A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the B pixel of the color filter in the XYZ color system under the C light source is 0.13 to A color filter characterized by 0.16, chromaticity y of 0.05 to 0.15, Rth at a wavelength of 450 nm of -50 nm to 50 nm, and contrast of 3500 or more.
(4) A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the R pixel in the XYZ color system under the C light source is 0.58. ˜0.68 and chromaticity y of 0.31 to 0.35, G pixel chromaticity x of 0.27 to 0.35 and chromaticity y of 0.54 to 0.62 and B Pixel chromaticity x is 0.13-0.16 and chromaticity y is 0.05-0.15, R pixel Rth at wavelength 650 nm, G pixel Rth at wavelength 550 nm, B pixel at wavelength 450 nm The Rth of each is -50 nm-50 nm, and contrast is 3500 or more, The color filter characterized by the above-mentioned.

Next, the physical property value chromaticity, contrast, and Rth of the color filter of the present invention will be described.
<Chromaticity>
In the color filter of the present invention, the chromaticity x of the R pixel is 0.58 to 0.68, the chromaticity y is 0.31 to 0.35, and the chromaticity x of the G pixel is 0.27 to 0.35. And the chromaticity y is 0.54 to 0.62, the chromaticity x of the B pixel is 0.13 to 0.16, and the chromaticity y is 0.05 to 0.15. Is preferable in that it can be achieved.
Here, in the present invention, “chromaticity” is measured with a microspectrophotometer (manufactured by Olympus Optical Co., Ltd .; OSP100 or 200), and is expressed as an xy value of the xyz color system calculated as a result of the C light source. To do.

<Contrast>
The contrast of each colored pixel of the color filter of the present invention is preferably 3500 or more, more preferably 4000 or more, still more preferably 4500 or more, and still more preferably 5000 or more. Any contrast is preferably 3500 or more. Further, the difference in contrast between the colored pixels is preferably 600 or less from the viewpoint of color purity, more preferably 410 or less, still more preferably 350 or less, and still more preferably 200 or less. When the contrast of each colored pixel constituting the color filter is 3500 or more, when an image of a liquid crystal display device having the color filter is observed, a vivid color display can be performed without an overall whitish image. Further, if the difference in contrast between the colored pixels is 600 or less, the amount of light leakage from the colored pixels during black display is not greatly different, the color balance is not lost, and the color reproducibility is good. This is preferable.

In the present invention, “contrast of colored pixels” means the contrast that is individually evaluated for each color for each of the R (red), G (green), and B (blue) pixels constituting the color filter. To do. The contrast measurement method is as follows.
In the state where the polarizing plates are overlapped on both sides of the object to be measured and the polarizing directions of the polarizing plates are parallel to each other, the backlight Y is applied from the side of one polarizing plate, and the luminance Y1 of the light passing through the other polarizing plate is obtained. taking measurement. Next, in a state where the polarizing plates are orthogonal to each other, a backlight is applied from the side of one polarizing plate, and the luminance Y2 of the light passing through the other polarizing plate is measured. The contrast is calculated by Y1 / Y2 using the obtained measurement value. Here, Nitto Denko G1220DUN was used as the polarizing plate, and a color luminance meter BM-5 (manufactured by Topcon Corporation) was used as the measuring instrument. Note that a polarizing plate used for contrast measurement is the same as a polarizing plate used for a liquid crystal display device using the color filter.

  The contrast of the color filter can be obtained by measuring in the same manner as the contrast of the colored pixels using a color filter substrate on which colored pixels such as RGB and a black matrix are formed. The contrast of the color filter is preferably 3500 or more.

<Rth (Retardation in the thickness direction)>
In the color filter of the present invention, at least one of the retardation Rth in the thickness direction at the wavelength of 550 nm of the R pixel, the wavelength of 550 nm of the G pixel, and the wavelength of 450 nm of the B pixel is −50 to 50 nm, preferably any Rth is also -50 to 50 nm.
In this specification, Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at a wavelength λ, respectively. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).

When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (if there is no slow axis, any in-plane film The light of wavelength λ nm is incident from each of the inclined directions in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction (with the direction of the rotation axis as the rotation axis). KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.

In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (1) and (2).

式（２）
Ｒｔｈ＝（（ｎｘ＋ｎｙ）／２−ｎｚ）×ｄ
注記：
上記のＲｅ（θ）は法線方向から角度θ傾斜した方向におけるレターデーション値を表す。
式中、ｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘ及びｎｙに直交する方向の屈折率を表し、ｄは膜厚を表す。

Formula (2)
Rth = ((nx + ny) / 2−nz) × d
Note:
The above Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.
In the formula, nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, nz represents the refractive index in the direction perpendicular to nx and ny, and d Represents the film thickness.

In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is the above-mentioned Re (λ), and the in-plane slow axis (determined by KOBRA 21ADH or WR) is the tilt axis (rotation axis) from −50 degrees to +50 degrees with respect to the film normal direction. The light of wavelength λ nm is incident from each inclined direction in 10 degree steps and measured at 11 points, and KOBRA 21ADH or WR is calculated.

In the above measurement, as the assumed value of the average refractive index, values in the polymer handbook (John Wiley & Sons, Inc.) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. Examples of the average refractive index values of main optical films are given below:
Cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).
The KOBRA 21ADH or WR calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny and nz.

  According to one aspect of the color filter of the present invention, a pixel group composed of colored pixels of at least R, G, and B colors on a light-transmitting substrate, and a black matrix that separates the pixels constituting the pixel group from each other It is a color filter comprised by these. The pixel group is a pixel group composed of at least R, G, and B3 colored pixels. Furthermore, the coloring pixel of another hue may be included. The arrangement of the pixel group is not particularly limited. When the pixel group is composed of colored pixels of three colors, R, G, and B, the arrangement is preferably a mosaic type, a triangle type, or the like, and when the pixel group is composed of colored pixels of four or more colors The arrangement may be any arrangement.

  As the light-transmitting substrate, a soda glass plate having a silicon oxide film on its surface, a low-expansion glass plate, a non-alkali glass plate, a known glass plate such as a quartz glass plate, or a plastic film is used.

  The black matrix may be formed after the pixel group system is formed on the light transmissive substrate, or the black matrix may be formed on the light transmissive substrate and then the pixel group may be formed.

[Production method of color filter]
The method for producing the color filter of the present invention is not particularly limited, but it is preferable to form each colored pixel from a colored photosensitive resin composition because it is easy to produce, and (A) a colorant and (B) It is more preferable to form from a colored photosensitive resin composition containing a retardation control agent, (C) a polymerizable monomer, and (D) a photopolymerization initiator. Hereinafter, as an example of a method for producing a color filter of the present invention, a production example including forming a colored pixel using the colored photosensitive resin composition containing the above (A) to (D) will be described.
<Colored photosensitive resin composition>
The colored photosensitive resin composition that can be used for the production of the color filter of the present invention contains at least (A) a colorant, (B) a retardation control agent, (C) a monomer, and (D) a photopolymerization initiator. It is a photosensitive resin composition.
(A) Colorant As the colorant used in the present invention, known pigments such as organic pigments, inorganic pigments and dyes can be used. However, they have sufficient transmission density, light resistance, adhesion to the substrate, and other various resistances. Various organic pigments are preferred because they are required. Further, a pigment is particularly preferable from the viewpoint of storage stability of the pixel. Specific examples of the colorant include pigments and dyes described in JP-A-2005-17716 [0038] to [0054], pigments described in JP-A-2004-361447 [0068] to [0072] The colorants described in JP-A-2005-17521 [0080] to [0088] can be preferably used.
The content of the colorant is not particularly limited, but from the viewpoint of obtaining a desired hue and concentration, the proportion of the colorant in the total solid content in the colored photosensitive resin composition is 20% by mass or more. Preferably, 20 to 70 mass% is more preferable, 25 to 60 mass% is more preferable, and 30 to 50 mass% is still more preferable.

In the present invention, the combination of the above-described pigments preferably used in combination is C.I. I. In pigment red 254, C.I. I. Pigment red 177, C.I. I. Pigment red 224, C.I. I. Pigment yellow 139 or C.I. I. A combination with Pigment Violet 23; I. In Pigment Green 36, C.I. I. Pigment yellow 150, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 138 or C.I. I. A combination with CI Pigment Yellow 180, and C.I. I. In Pigment Blue 15: 6, C.I. I. Pigment violet 23 or C.I. I. A combination with Pigment Blue 60 is mentioned.
C. in the pigment when used together in this way. I. Pigment red 254, C.I. I. Pigment green 36, C.I. I. The content of Pigment Blue 15: 6 is C.I. I. Pigment Red 254 is preferably 60% by mass or more, particularly preferably 70% by mass or more. C. I. The pigment green 36 is preferably 50% by mass or more, particularly preferably 60% by mass or more. C. I. Pigment Blue 15: 6 is preferably 80% by mass or more, and particularly preferably 90% by mass or more.

  The pigment used in the present invention preferably has a number average particle size of 0.001 to 0.1 μm from the viewpoint of achieving both dispersion stability and high contrast, and more preferably 0.01 to 0.08 μm. The “particle diameter” as used herein refers to the diameter when the electron micrograph image of the particle is a circle of the same area, and the “number average particle diameter” is the above-mentioned particle diameter for a number of particles, This 100 average value is said.

  The pigment is desirably used as a dispersion. This dispersion can be prepared by dispersing a composition obtained by previously mixing the pigment, a pigment dispersant described later, and an organic solvent using a known disperser. At this time, a small amount of resin may be added in order to impart dispersion stability of the pigment. Moreover, it is also possible to prepare the composition obtained by mixing the pigment and the pigment dispersant in advance by adding to a monomer described later and dispersing it. The disperser used for dispersing the pigment is not particularly limited. For example, a kneader described in Kazuzo Asakura, “Encyclopedia of Pigments”, first edition, Asakura Shoten, 2000, page 438, Known dispersing machines such as a roll mill, an atrider, a super mill, a dissolver, a homomixer, and a sand mill can be used. Further, fine grinding may be performed using frictional force by mechanical grinding described on page 310 of the document.

(B) Retardation Control Agent In this specification, the term “retardation control agent” is any of a retardation increasing agent that increases retardation by addition and a retardation reducing agent that decreases retardation by addition. Is included. As described above, the retardation referred to here may be either Re or Rth, or both. The “retardation control agent” refers to an agent that changes (increases or decreases) the retardation by 2 nm or more by including the agent. Even when the same retardation is used, the amount of change may increase or decrease depending on the addition ratio of the retardation in the composition and the film thickness of the layer to be formed. The amount of change in the usage pattern (the usage pattern in which the addition rate and the film thickness of the layer are the same) shall be used.
In particular, in the present invention, it is preferable to use a retardation increasing agent as the retardation controlling agent.

Re control agent:
In the present invention, as a retardation control agent capable of controlling the absolute value of Re (referred to as “Re control agent”), a compound having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution is used. preferable. By using such a compound, the absolute value can be controlled without substantially changing the wavelength dependence of Re in the visible region.

As the Re control agent, a rod-shaped compound is preferably used, a rod-shaped compound having at least one aromatic ring is more preferably used, and a rod-shaped compound having at least two aromatic rings is more preferably used.
The rod-shaped compound used as the Re control agent preferably has a linear molecular structure. The linear molecular structure means that the molecular structure of the rod-shaped compound is linear in the thermodynamically most stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation is performed using molecular orbital calculation software (eg, WinMOPAC2000, manufactured by Fujitsu Limited), and a molecular structure that minimizes the heat of formation of a compound can be obtained. The molecular structure being linear means that the angle of the molecular structure is 140 degrees or more in the thermodynamically most stable structure obtained by calculation as described above.

The rod-shaped compound used as the Re control agent preferably exhibits liquid crystallinity. More preferably, the rod-like compound exhibits liquid crystallinity upon heating (has thermotropic liquid crystallinity). The liquid crystal phase to which the compound is transferred is preferably a nematic phase or a smectic phase.
Specific examples of preferable compounds are described in JP-A No. 2004-4550, but are not limited thereto. Two or more rod-shaped compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination.

  The rod-like compound can be synthesized with reference to methods described in literature. As literature, Mol. Cryst. Liq. Cryst. 53, 229 (1979), 89, 93 (1982), 145, 111 (1987), 170, 43 (1989), J. Am. Am. Chem. Soc. 113, p. 1349 (1991), p. 118, p. 5346 (1996), p. 92, p. 1582 (1970). Org. Chem. 40, 420 (1975), Tetrahedron, 48, 16, 1637 (1992).

  An aromatic compound having at least two aromatic rings may be used as a retardation increasing agent. Two or more aromatic compounds may be used in combination. The aromatic ring of the aromatic compound includes an aromatic hetero ring in addition to the aromatic hydrocarbon ring. Examples thereof include compounds described in European Patent Application Publication No. 91656, JP-A 2000-1111914, 2000-275434, and the like.

  The amount of the Re control agent added is preferably 0.1 to 30% by mass and preferably 0.5 to 20% by mass in the composition used to form the colored layer (colored pixel) of each color. More preferably.

Rth control agent:
In the present invention, as a retardation control agent capable of controlling the absolute value of Rth (referred to as “Rth control agent”), it is preferable to use a compound having maximum absorption in a wavelength region of 250 to 400 nm, and substantially in the visible region. It is preferable to use a compound that does not have absorption. The Rth control agent is preferably an agent that does not affect Re.

As the Rth control agent, a discotic compound is preferably used.
Examples of the discotic compound include compounds containing an aromatic hydrocarbon ring and an aromatic heterocycle. In particular, the compound containing an aromatic hydrocarbon ring is preferably a compound containing a 6-membered ring (that is, a benzene ring).
The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.
As the aromatic ring, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring are preferable, In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, compounds disclosed in JP-A No. 2001-166144 are preferably used.

  The addition amount of the Rth control agent is preferably 0.01 to 20% by mass, more preferably 0.05 to 15% by mass in the composition used for forming the colored layer of each color. More preferably, it is 0.1-10 mass%. Two or more kinds of compounds may be used in combination.

  The form of the retardation control agent is not particularly limited, and may be either solid or liquid. In the said photosensitive resin composition, although it may disperse | distribute or melt | dissolve, it is preferable from the point of the color purity and contrast of the colored pixel to form. In the photosensitive resin composition, when the retardation control agent is dispersed as particles, the average particle size is preferably 0.1 μm or less, and preferably 0.08 μm or less. More preferred. If the average particle size of the dispersed particles exceeds the above range, it may be difficult to make the contrast of each colored pixel 3500 or more.

(C) Monomer The monomer is preferably a monomer that has two or more ethylenically unsaturated double bonds and undergoes addition polymerization upon irradiation with light. The monomer or oligomer species and addition amount described in paragraph No. [0011] of JP-A-2006-23696 can be suitably used in the present invention.

(D) Photopolymerization initiator As a photopolymerization initiator, polymerization of a monomer having the above-mentioned dispersion function is initiated by irradiation with radiation such as visible light, ultraviolet light, far ultraviolet light, electron beam, or X-ray (also referred to as exposure). A compound capable of generating active species, and known light described in paragraphs [0012] of JP-A-2006-23696, paragraphs [0032] to [0047] of JP-A-2006-154804, etc. It can be suitably selected from the polymerization initiator or photopolymerization initiator type and content.

(E) Other components In addition to the essential components (A) to (D), binders, monomers, plasticizers, fillers, stabilizers, and polymerization prohibitions that are generally used as resist materials as necessary. It may contain known components such as an agent, a surfactant, a solvent, and an adhesion promoter. Examples of the other components include those described in paragraph numbers [0010] to [0058] of JP-A-2006-23696, paragraph numbers [0037] to [0021] of JP-A-2006-208480, and the like. It can be suitably used in the present invention.

Each colored pixel transmits light using a photosensitive layer formed by applying the colored photosensitive resin composition onto the surface of a light-transmitting substrate or a transfer material prepared using the colored photosensitive resin composition. It is produced by patterning a photosensitive layer formed by transferring onto a conductive substrate by a known method. From the viewpoint of cost reduction, it is preferable to use a transfer material. The transfer material is obtained by forming a photosensitive layer made of at least the colored photosensitive resin composition on a temporary support, and is pressure-bonded to the surface of a light-transmitting substrate to attach the photosensitive layer to the substrate surface. Can be transferred to. As described in JP-A-5-72724 and the like, the transfer material may have a thermoplastic resin layer and a separation layer that facilitate transfer in addition to the temporary support and the photosensitive layer. . A preferable configuration example of the transfer material includes a configuration in which a temporary support / thermoplastic resin layer / intermediate layer / photosensitive layer / protective film are laminated in this order.
The temporary support, the thermoplastic resin layer, the intermediate layer, the protective film, and the method for producing the transfer material constituting the transfer material are described in paragraphs [0023] to [0066] of JP-A-2005-3861. Can be mentioned as suitable.

  The thickness of the photosensitive layer formed on the light-transmitting substrate is preferably 0.2 to 5.0 μm, and more preferably 0.2 to 3.0 μm.

The method for patterning the photosensitive layer formed on the light transmissive substrate to form the colored pixels is not particularly limited. For example, after forming a photosensitive layer on a light-transmitting substrate as described above, the photosensitive layer is exposed on the entire surface or in a pattern. When exposed in a pattern, it can be developed to form colored pixels. Other steps such as post-exposure and post-bake may be further performed as necessary. After forming a colored pixel group of one color through formation of a photosensitive layer by transfer, exposure, and development, the same series of steps is repeated again to form a colored pixel group of all colors, and a color filter Can be produced.
Regarding the patterning process such as exposure and development, the method described in paragraph Nos. [0096] to [0108] of JP-A-2006-251095 and the paragraph numbers [0085] to [0098] of JP-A-2006-208480 are disclosed. ] Can be suitably used in the present invention.

  Further, the color filter of the present invention preferably has a black matrix (BM) from the viewpoint that the contrast can be further improved. The BM may be formed before the pixel group is formed, or may be formed after the pixel group is formed. For example, paragraph numbers [0021] to [0074] of JP 2005-3861 A, black matrices described in paragraph numbers [0012] to [0021] of JP 2004-240039 A, and JP 2006-17980 A. Reference can be made to known BM production methods such as paragraph numbers [0015] to [0020] of Japanese Patent Publication No. Gazette and the black matrix described in paragraph numbers [0009] to [0044] of JP-A No. 2006-10875.

[Liquid Crystal Display]
The liquid crystal display device of the present invention has the color filter of the present invention. The liquid crystal display device of the present invention includes an electrode substrate, a polarizing film, a retardation film, a backlight, a spacer, in addition to the color filter. Generally composed of various members such as a viewing angle compensation film, an antireflection film, a light diffusion film, and an antiglare film. The light-shielded image in the present invention can be applied to a liquid crystal display device composed of these known members. For example, “'94 Liquid Crystal Display Peripheral Materials / Chemicals Market (Kentaro Shima, Ltd. issued by CMC 1994)”, “2003 Liquid Crystal Related Markets Current Status and Future Prospects (Volume 2) (Omoyoshikichi Co., Ltd.) The type of LCD includes STN, TN, VA, IPS, OCS, R-OCB, and the like.

As one of the liquid crystal display devices, at least one is provided with at least a color filter, a liquid crystal layer, and liquid crystal driving means (including a simple matrix driving method and an active matrix driving method) between a pair of light-transmitting substrates. Is mentioned.
As the color filter, a color filter having a plurality of pixel groups as described above and each pixel constituting the pixel group being separated from each other by the black matrix according to the present invention can be suitably used. Since the color filter has high flatness, the liquid crystal display device including the color filter does not generate cell gap unevenness between the color filter and the substrate, and the occurrence of display defects such as color unevenness is improved.

Further, as another aspect of the liquid crystal display device, at least one of them is provided with a color filter, a liquid crystal layer, and liquid crystal driving means between a pair of light-transmitting substrates, and the liquid crystal driving means is an active element (for example, TFT) and a black matrix formed using the light-shielding resist composition or transfer material of the present invention is formed between the active elements.
The liquid crystal display device is described in, for example, “Next-generation liquid crystal display technology (edited by Tatsuo Uchida, published by Side Industry Research Committee, 1994)”. The display device (liquid crystal display device) of the present invention is not particularly limited, and can be applied to various types of liquid crystal display devices described in, for example, the “next generation liquid crystal display technology”. Among these, the present invention is particularly effective for a color TFT liquid crystal display device.

  The color TFT liquid crystal display device is described in, for example, “Color TFT liquid crystal display (issued in 1996 by Kyoritsu Publishing Co., Ltd.)”. Further, the present invention can be applied to a liquid crystal display device with a wide viewing angle such as a lateral electric field driving method such as IPS and a pixel division method such as MVA. These methods are described, for example, on page 43 of "EL, PDP, LCD display-latest technology and market trends-(issued in 2001 by Toray Research Center Research Division)".

  Examples of the liquid crystal that can be used in the liquid crystal display device include nematic liquid crystal, cholesteric liquid crystal, smectic liquid crystal, and ferroelectric liquid crystal.

  The color filter of the present invention includes ECB (Electrically Controlled Birefringence), TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (Optical Liquid Crystal). (Vertical Aligned), HAN (Hybrid Aligned Nematic), GH (Guest Host), etc., can be used for liquid crystal display devices in various modes. Among them, it is preferable to use for TN, IPS, OCB (, STN (Super Twisted Nematic), and VA mode liquid crystal display devices.

  Hereinafter, the present invention will be described more specifically with reference to examples. The materials, reagents, ratios, instruments, operations, and the like shown in the following examples can be appropriately changed without departing from the scope of the present invention, and therefore the present invention is not limited to the examples shown below. In the following examples, unless otherwise specified, both “%” and “part” are based on mass, and the molecular weight represents a weight average molecular weight.

[Example 1]
A black matrix (BM) and RGB pixels were formed on the substrate by the same method as in Example 1 of JP-A-2006-208480.
Specifically, first, the colored photosensitive resin composition K1 described in Example 1 of the publication is used by using the glass substrate coater having the slit-like nozzle used in Example 1 of JP-A-2006-208480. With a BM equipped with a striped black matrix having an optical density of 3.4, a film thickness of 1.5 μm, and a width of 100 μm, which is then developed by the same development method. A substrate was obtained.
Next, each of the colored photosensitive resin compositions R1, G1, and B1 shown in Table 1 below was applied to the opening on the substrate with BM using the same coater as described above, and the thickness of 2 μm 3 Each of the colored layers was formed, developed by the developing method described in the Example, and patterned to produce a color filter having three RGB colors.
Next, using the color filter, a liquid crystal display device was produced by the method described in paragraph numbers [0132] to [0136] of JP-A-2006-208480.

Here, preparation of colored photosensitive resin composition R1, G1, B1 of Table 1 is demonstrated.
The colored photosensitive resin composition R1 was first weighed in the amounts of R pigment dispersion 1, R pigment dispersion 2, and propylene glycol monomethyl ether acetate in the amounts shown in Table 1, and mixed at a temperature of 24 ° C. (± 2 ° C.). Stir at 150 rpm for 10 minutes, then the amount of methyl ethyl ketone, binder 2, DPHA solution, 2-trichloromethyl-5- (p-styrylstyryl) -1,3,4-oxadiazole, 2 , 4-Bis (trichloromethyl) -6- [4- (N, N-diethoxycarbonylmethylamino) -3-bromophenyl] -s-triazine and phenothiazine were weighed out at a temperature of 24 ° C. (± 2 ° C.). In this order, the mixture was stirred at 150 rpm for 30 minutes, and the retardation control agent A and surfactant 1 in the amounts shown in Table 1 were weighed out and the temperature was 24 ° C. ( ± 2 ° C.), stirred at 30 rpm for 5 minutes, and filtered through nylon mesh # 200.

Of the compositions listed in Table 1, the composition of the R pigment dispersion 1 is
・ C. I. P. R. 254 (trade name: Irgaphor Red B-CF,
Ciba Specialty Chemicals Co., Ltd.) 8 parts N, N'-bis- (3-diethylaminopropyl) -5- {4-
[2-oxo-1- (2-oxo-2,3-dihydro-1H-
Benzimidazol-5-ylcarbamoyl) -propylazo]-
Benzoylamino} -isophthalamide 0.8 parts Polymer (benzyl methacrylate / methacrylic acid = 72/28
Random copolymer of molar ratio, weight average molecular weight 37,000) 6.4 parts, propylene glycol monomethyl ether acetate 83.2 parts.

The composition of the R pigment dispersion 2 is
・ C. I. P. R. 177 (Product name: Chromophthal Red A2B,
Ciba Specialty Chemicals Co., Ltd.) 18 parts Polymer (benzyl methacrylate / methacrylic acid = 72/28
Random copolymer of molar ratio, weight average molecular weight 37,000) 12 parts / propylene glycol monomethyl ether acetate 70 parts.
The above-mentioned R pigment dispersion 1 and R pigment dispersion 2 were dispersed for 27 hours at a peripheral speed of 9 m / s using a motor mill M-50 (manufactured by Eiger Japan Co., Ltd.) and zirconia beads having a diameter of 0.65 mm. did.

  The colored photosensitive resin composition G1 is first weighed in the amounts of G pigment dispersion 1, Y pigment dispersion 1, and propylene glycol monomethyl ether acetate in the amounts shown in Table 1, and mixed at a temperature of 24 ° C. (± 2 ° C.). Stir at 150 rpm for 10 minutes, then methyl ethyl ketone, cyclohexanone, binder 1, DPHA solution, 2-trichloromethyl-5- (p-styrylstyryl) -1,3,4-oxadiazole in the amounts listed in Table 1, 2,4-bis (trichloromethyl) -6- [4- (N, N-diethoxycarbonylmethylamino) -3-bromophenyl] -s-triazine and phenothiazine are weighed out and the temperature is 24 ° C. (± 2 ° C.). In this order, the mixture was stirred at 150 rpm for 30 minutes, and the retardation control agent A and surfactant 1 in the amounts shown in Table 1 were weighed. And added at a temperature of 24 ° C. (± 2 ° C.), stirred at 30 rpm for 5 minutes, and filtered through nylon mesh # 200.

As the G pigment dispersion 1, “trade name: GT-2” manufactured by FUJIFILM Electronics Materials Co., Ltd. was used.
As the Y pigment dispersion 1, “trade name: CF EX3393” manufactured by Mikuni Color Co., Ltd. was used.

  The colored photosensitive resin composition B1 is first weighed in the amount of B pigment dispersion 1 and propylene glycol monomethyl ether acetate listed in Table 1, mixed at a temperature of 24 ° C. (± 2 ° C.), and stirred at 150 rpm for 10 minutes. Next, methyl ethyl ketone, binder 3, DPHA solution, 2-trichloromethyl-5- (p-styrylstyryl) -1,3,4-oxadiazole, and phenothiazine were weighed out, and this was performed at a temperature of 25 ° C. (± 2 ° C.). They were added in order, and stirred at a temperature of 40 ° C. (± 2 ° C.) at 150 rpm for 30 minutes. Further, the amounts of retardation control agent A and surfactant 1 in the amounts shown in Table 1 were weighed, and the temperature was 24 ° C. (± 2 ° C.), stirred at 30 rpm for 5 minutes, and filtered through nylon mesh # 200.

B Pigment Dispersion 1 (made by Mikuni Color Co., Ltd., trade name: CF Blue EX3357) was used.
B Pigment Dispersion 2 (made by Mikuni Color Co., Ltd., trade name: CF Blue EX3383) was used.

The composition of binder 1 is
・ Polymer (benzyl methacrylate / methacrylic acid = 78/22
Random copolymer of molar ratio, weight average molecular weight 37,000) 27 parts, propylene glycol monomethyl ether acetate 73 parts

The composition of binder 2 is
・ Polymer (benzyl methacrylate / methacrylic acid / methyl methacrylate)
= Random copolymer of 38/25/37 molar ratio,
Weight average molecular weight 38,000) 27 parts ・ Propylene glycol monomethyl ether acetate 73 parts

The composition of binder 3 is
・ Polymer (benzyl methacrylate / methacrylic acid / methyl methacrylate)
= Random copolymer with a molar ratio of 36/22/42,
(Weight average molecular weight 38,000) 27 parts propylene glycol monomethyl ether acetate 73 parts.

The composition of the DPHA solution is
・ Dipentaerythritol hexaacrylate (containing polymerization inhibitor MEHQ 500ppm, Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA) 76 parts ・ Propylene glycol monomethyl ether acetate 24 parts

The composition of Surfactant 1 (Dainippon Ink Chemical Co., Ltd., trade name: Megafac F780F)
And _{· C 6 F 13 CH 2 CH} 2 OCOCH = CH 2 40 parts,
H (OCH (CH ₃ ) CH ₂ ) ₇ OCOCH═CH ₂ 55 parts;
A copolymer with 5 parts of H (OCH ₂ CH ₂ ) ₇ OCOCH═CH ₂ ;
The weight average molecular weight is 30,000 30 parts and methyl ethyl ketone 70 parts.

Retardation control agent A: absorption wavelength 320 nm

[Example 2]
A color filter and a liquid crystal display device were prepared in the same manner as in Example 1, except that the R1, G1, and B1 formulations in Example 1 were changed to the R2, G2, and B2 formulations described in Table 1 above. did.
However, the following components were used in Table 1 above.
As the R pigment dispersion 3, (Mikuni Dye Co., Ltd., trade name: CF Red EX3500) was used.
As the G pigment dispersion 2, “trade name: CDP-G22” manufactured by FUJIFILM Electronics Materials Co., Ltd. was used.
As the Y pigment dispersion 2, “trade name: CDP-Y27” manufactured by FUJIFILM Electronics Materials Co., Ltd. was used.
As the B pigment dispersion 3, “trade name: CDP-B31” manufactured by FUJIFILM Electronics Materials Co., Ltd. was used.

Retardation control agent B: absorption wavelength 274 nm

[Example 3]
Example 1 is the same as Example 1 except that the color filter manufacturing method is changed to a transfer method of forming a pattern on a substrate using the transfer material described in Example 11 of JP-A-2006-276818. A color filter and a liquid crystal display device were respectively produced by the method. In Example 11 of the publication, the colored photosensitive resin compositions R101, G101, and B101 are changed to the colored photosensitive resin compositions R1, G1, and B1 shown in Table 1 above, and the other methods are the same. Photosensitive resin transfer materials R101, G101 and B101 were produced.

[Example 4]
Example 2 is the same as Example 2 except that the color filter manufacturing method is changed to a transfer method in which a pattern is formed on a substrate using the transfer material described in Example 11 of JP-A-2006-276818. A color filter and a liquid crystal display device were respectively produced by the method. In Example 11 of the publication, the colored photosensitive resin compositions R101, G101, and B101 are changed to the colored photosensitive resin compositions R2, G2, and B2 shown in Table 1 above, and the other methods are the same. Photosensitive resin transfer materials R101, G101 and B101 were produced.

[Comparative Example 1]
Example 3 except that the formulation of the colored photosensitive resin compositions R1, G1, and B1 in Example 3 was changed to the formulation of the colored photosensitive resin compositions R3, G3, and B3 shown in Table 1 above. A color filter and a liquid crystal display device were produced in the same manner as described above.

[Comparative Example 2]
Treated pigment PY-138 (B) was prepared in the same manner as described in Production Examples 1 to 4 of JP-A No. 2000-187114.
Using this treated pigment Y-138 (B), a red colored paste RC-4 prepared in Example 4 of the publication was prepared, and the colored photosensitive resin composition R1 used in Example 3 was converted into this RC- A color filter and a liquid crystal display device were produced in the same manner as in Example 3 except that the number was changed to 4.

<Evaluation items>
<Chromaticity>
The chromaticity of the color filter obtained above was measured at a pinhole diameter of 5 μm using a microspectrophotometer (manufactured by Olympus Optical Co., Ltd .; OSP100), and calculated as the result of the C light source.

<Rth>
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (if there is no slow axis, any in-plane film The light of wavelength λ nm is incident from each of the inclined directions in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction (with the direction of the rotation axis as the rotation axis). KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.
Table 2 below shows the Rth of each colored pixel measured at each measurement wavelength.

<Measurement of contrast of colored pixels>
The contrast of each colored pixel constituting the color filter obtained above was measured by the following measuring method, and the difference in contrast between the colored pixels was calculated. The results are shown in Table 2.
(Measurement method of colored pixel contrast)
Using a three-wavelength cold cathode tube light source (FWL18EX-N, manufactured by Toshiba Lighting & Technology Corp.) as a backlight unit, a color filter between two polarizing plates (G1220DUN manufactured by Nitto Denko Corporation) Or, by installing a monochrome substrate and dividing the Y value of the chromaticity of the light that passes when the polarizing plate is installed in parallel Nicol, by dividing the Y value of the chromaticity of the light that passes when installed in crossed Nicol The contrast was determined. A color luminance meter (BM-5 manufactured by Topcon Corporation) was used for the measurement of chromaticity.
Two polarizing plates, a color filter, and a color luminance meter were installed at a position 13 mm from the backlight, a polarizing plate at a position 40 mm to 60 mm, and a cylinder 11 mm in diameter and 20 mm in length. Light was irradiated to a measurement sample installed at a position of 65 mm, and the transmitted light was measured with a color luminance meter installed at a position of 400 mm through a polarizing plate installed at a position of 100 mm. The measurement angle of the color luminance meter was set to 2 °. The light amount of the backlight was set so that the luminance when the two polarizing plates were installed in parallel Nicol was 1280 cd / m ² without the sample being installed.
The measured contrast of each colored pixel is shown in Table 2 below.

<Evaluation of panel contrast>
The difference between the luminance when the VA mode liquid crystal display devices manufactured in the above Examples and Comparative Examples were displayed in black and the luminance when displayed in white was measured, and the results are shown in Table 3.
For the measurement of black and white contrast, “BM-5” manufactured by TOPCON CORPORATION JAPAN was used as a luminance meter, and this was installed at a distance of 50 cm in the vertical direction from the panel surface. The measurement was performed in a dark room.

<Evaluation of viewing angle dependency>
The liquid crystal display devices manufactured in the above-mentioned examples and comparative examples were developed to produce R, G, B single-color images at an angle of 60 degrees to the left and right (total of 120 degrees) centered on the vertical direction from the panel surface, and density unevenness was increased to 10 people. Color shift (color unevenness) was determined.
○: Number of people recognized as having a color shift 0: Δ: Number of people recognized as having a color shift 1 to 2 people ×: Number of people recognized as having a color shift 3 or more

Claims (6)

A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the R pixel of the color filter in the XYZ color system under the C light source is 0.58 to 0.68. And a chromaticity y of 0.31 to 0.35, an Rth (retardation in the thickness direction) at a wavelength of 650 nm of −50 nm to 50 nm, and a contrast of 3500 or more. . A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the G pixel of the color filter in the XYZ color system under the C light source is 0.27 to 0.35. And a chromaticity y of 0.54 to 0.62, a Rth (retardation in the thickness direction) at a wavelength of 550 nm of -50 nm to 50 nm, and a contrast of 3500 or more. . A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the B pixel of the color filter in the XYZ color system under the C light source is 0.13 to 0.16 And a chromaticity y of 0.05 to 0.15, an Rth (retardation in the thickness direction) at a wavelength of 450 nm of -50 nm to 50 nm, and a contrast of 3500 or more. . A color filter having at least three colored pixels of R, G, and B, and the chromaticity x of the R pixel in the XYZ color system under the C light source of the color filter is 0.58-0. 68, the chromaticity y is 0.31 to 0.35, the G pixel chromaticity x is 0.27 to 0.35, the chromaticity y is 0.54 to 0.62, and the B pixel chromaticity x. Is 0.13 to 0.16 and the chromaticity y is 0.05 to 0.15. The Rth of the R pixel at the wavelength of 650 nm, the Rth of the G pixel at the wavelength of 550 nm, and the Rth of the B pixel at the wavelength of 450 nm are − The color filter according to claim 1, wherein the color filter is 50 nm to 50 nm and has a contrast of 3500 or more. A colored pixel of at least one color of R, G, and B is a colored photosensitive resin composition containing at least (A) a colorant, (B) a retardation control agent, (C) a monomer, and (D) a photopolymerization initiator. The color filter according to claim 1, wherein the color filter is a formed colored pixel. A liquid crystal display device comprising the color filter according to claim 1.