JP2008185986A - Color filter and liquid crystal display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter which is improved in both oblique visibility and front visibility while retaining the high contrast characteristics of a color filter, and a liquid crystal display device using the same. <P>SOLUTION: The color filter comprises a plurality of colored layers including at least one colored layer formed by curing a colored composition containing a retardation regulator on a transparent substrate, wherein each colored layer of the color filter has a contrast ratio (C/CS) of >0.45 when the colored layer is held between two polarizing plates, backlight is applied to one of the polarizing plates and light passing through the other of the polarizing plates is measured with a luminance meter, wherein the contrast C (C=Lp/Lc) is calculated from the ratio of the luminance (Lp) of light using the parallel polarizing plates to the luminance (Lc) of light using the orthogonal polarizing plates, and the contrast CS is measured when only the transparent substrate with no colored pixels is held between the polarizing plates. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a color filter in which a thickness direction retardation of a green colored pixel is optimized, and a liquid crystal display device including the color filter.

The liquid crystal display device is a display element that utilizes the birefringence of liquid crystal molecules, and includes a liquid crystal cell, a polarizing element, and an optical compensation layer. Liquid crystal display devices are roughly classified into two types according to the type of light source: a transmissive type having a light source inside and a reflective type having a structure using an external light source.
The transmissive liquid crystal display device has a configuration in which two polarizing elements are attached to both sides of a liquid crystal cell, and one or two optical compensation layers are disposed between the liquid crystal cell and the polarizing element.
In the reflective liquid crystal display device, the reflector, the liquid crystal cell, one optical compensation layer, and one polarizing element are arranged in this order. In the liquid crystal cell, rod-like liquid crystal molecules sandwiched between two substrates are aligned and sealed, and a voltage is applied to the electrode layers disposed on both sides or one side of the two substrates, thereby producing a rod-like liquid crystal. This is a mechanism for switching light transmission / light-shielding by changing the orientation state of the active molecule.

  The liquid crystal cell is different in the alignment state of rod-like liquid crystalline molecules, TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (Optically Compensated Bend), STN (Supper Twisted Nematic). Various display modes such as VA (Vertically Aligned) and HAN (Hybrid Aligned Nematic) have been proposed.

  The polarizing element generally has a configuration in which two transparent protective films made of triacetyl cellulose (hereinafter referred to as TAC) are attached to both sides of a polarizing film obtained by diffusing iodine into polyvinyl alcohol (hereinafter referred to as PVA). Have

  Various optical compensation layers have been proposed. For example, in a VA (vertical alignment) mode liquid crystal display device capable of high-contrast display, the optical axis is perpendicular to the substrate, and negative birefringence anisotropy. And a retardation film (positive A plate) having an optical axis horizontal to the substrate and having positive birefringence anisotropy (for example, Patent Document 1) reference).

  In recent years, liquid crystal display devices have been evaluated for their space-saving, light-weight, and power-saving properties due to their thinness. There is a strong demand to further improve display performance.

  Specifically, normally black mode IPS and VA liquid crystal display devices capable of higher contrast and wide viewing angle display are particularly preferred for TV applications, and the above-described optical compensation layer is often used. However, most of them are designed to have an optimum value so as to minimize the color at the time of black display when viewed from the front and the color shift when viewed from an oblique direction.

However, when the thickness direction retardation values (hereinafter referred to as Rth (R), Rth (G), and Rth (B)) of the red, green, and blue colored pixel layers constituting the color filter are different from each other, they are viewed obliquely. This causes a problem that coloring is observed during black display.
In particular, the thickness direction retardation values of the red, green, and blue colored pixel layers are non-uniform, that is, Rth (R) <Rth (G)> Rth (B) or Rth (R)> Rth (G) <Rth (B ), The optical compensation layer exhibiting unidirectional (continuous) wavelength dispersion with respect to the wavelength of light can be used to calculate the thickness direction retardation value of each color unevenness, which is a high level of display quality that is required recently. Can no longer compensate.
Specifically, the visibility from the front (vertical direction) with respect to the display surface is good, but in a visibility observed from an oblique angle such as 45 degrees (hereinafter, abbreviated as oblique visibility), only a specific color is present. As a result, light leaks, and when black is displayed, red, blue, or greenish colors are produced.

Since the retardation of the color filter was relatively small compared to other members used in the liquid crystal display device, this problem has not been emphasized so far, but high contrast and wide viewing angle characteristics are required. It has become a level that cannot be ignored on LCD TVs.
In particular, a high-contrast liquid crystal display device having 1000 or 3000 or more has been required to have a high image quality required for black display.
Usually, since optical design is performed centering on green, if the retardations of the red, blue, and green colored pixel layers differ greatly, a problem arises in oblique visibility as leakage light.
For this, a polymer having a planar structure group is contained in the side chain of the colored polymer thin film, or a birefringence reducing particle having a birefringence opposite to that of the polymer is contained in the colored polymer thin film. Thus, attempts have been made to reduce the amount of retardation of the color filter (for example, Patent Documents 1 and 2).
JP 2000-136253 A JP 2000-187114 A

  However, the thickness direction retardation value of the color filter varies greatly depending on the type of pigment used, and the thickness direction retardation value varies depending on the fineness or dispersion of the pigment or matrix resin (for example, acrylic resin or cardo resin). The present inventors have found that the degree becomes large, and a method including these polymer thin film and birefringence reducing particles cannot obtain a sufficient effect, and cannot solve the above problem.

  In particular, color filters based on transparent resins represented by acrylic resins with good dispersibility of organic pigments for high-contrast liquid crystal display devices require required high contrast values (1000 or more, more preferably 3000 It was difficult to improve oblique visibility while maintaining the above.

In addition, in the prior art, a color filter with a small birefringence is simply an excellent color filter, and even though a means for improving oblique visibility has been studied, as a high-contrast liquid crystal display device, There has been little study on means for reducing the thickness direction retardation value to a level that does not cause a problem in black display and adjusting the thickness direction retardation of each color to an optimum value.
On the other hand, the present inventors newly changed the retardation of the color filter layer of each of the red, green and blue color pixel patterns, red represents positive or negative retardation, blue represents positive retardation, and green represents negative retardation. It was found to show retardation of.

Therefore, the present invention is based on the above-mentioned new knowledge, and in order to improve the oblique visibility in a high-contrast liquid crystal display device, in particular, a color filter that can appropriately control the thickness direction retardation value of the green colored pixel layer. The purpose is to provide.
In addition, the present invention is based not only on the display surface observation direction (normal direction) but also on an oblique direction shifted by about 45 degrees from the observation direction by combining with the optical compensation layer and other components based on the new knowledge. Another object of the present invention is to provide a liquid crystal display device that is not colored and has good front (display surface normal direction) visibility, or a color filter in which the thickness direction retardation value is appropriately controlled.
A further object of the present invention is to provide a liquid crystal display device that is manufactured by combining the color filter, an optical compensation layer, and other components, and that has no coloration even when viewed from an oblique direction and has good visibility. .

  The invention according to claim 1 is the invention according to claim 1, wherein at least one color has a plurality of colored layers formed by curing and forming a colored composition to which a retardation adjusting agent is added on a transparent substrate. A color filter comprising a colored layer, wherein each colored layer of the color filter is sandwiched between two polarizing plates, a backlight is applied from one polarizing plate side, and light transmitted through the other polarizing plate is measured by a luminance meter The contrast C (C = Lp / Lc) calculated from the ratio of the light luminance (Lp) when the polarizing plate is in the parallel state and the light luminance (Lc) when the polarizing plate is in the orthogonal state, and a transparent substrate without colored pixels It is a color filter characterized in that a colored layer having a contrast CS ratio (C / CS) measured by sandwiching only between polarizing plates is greater than 0.45 has two or more colors.

  The invention according to claim 2 is the color filter according to claim 1, wherein the retardation adjusting agent comprises a compound that increases retardation.

  The invention according to claim 3 is characterized in that the retardation adjusting agent is one or more selected from an organic compound having a planar structure group having one or more crosslinkable groups, a melamine compound, a porphyrin compound, and a polymerizable liquid crystal compound. The color filter according to claim 2, wherein the color filter is an organic compound selected from the group consisting of:

  The invention according to claim 4 is the color filter according to any one of claims 1 to 3, wherein the organic pigment is an organic pigment having an average primary particle in the range of 5 to 40 nm. .

  The invention according to claim 5 is the color filter according to claim 1, wherein the colored pixel includes at least green.

  A sixth aspect of the present invention is a liquid crystal display device using the color filter according to any of the first to fifth aspects.

As described above, according to the present invention, the retardation specific to the color filter can be adjusted. Therefore, while the high-quality color filter has a contrast value of 1000 or more, or 3000 or more, the thickness direction retardation of each color can be adjusted. It became possible to reduce the difference.
In addition, by specifying the pigment type to be used, it is possible to further improve the visibility from the front by dispersing these in the transparent resin.

  When a liquid crystal display is manufactured by using the color filter, it is possible to obtain a liquid crystal display device that reduces variation in the polarization state of light passing through the display region of each colored pixel and has good visibility in the oblique direction and the front. did it.

  Hereinafter, embodiments of the present invention will be described.

  The thickness direction retardation value of each colored pixel layer in the present invention is determined in a visible region (at least in the visible region (color filter 3 including three colored pixels 3 of red 3 (R), green 3 (G), and blue 3 (B)). For example, continuous light including the wavelength of the transmitted light peak range (wavelength of light from 380 nm to 780 nm) is irradiated from the front and a plurality of inclined angles, and the three-dimensional refractive index is measured using a phase difference measuring device such as a spectroscopic ellipsometer. It is obtained by measuring.

For example, the phase difference measurement is performed with light from at least two directions of the front surface and an incident angle of 45 degrees at a wavelength of 610 nm for a red color pixel, 550 nm for a green color pixel, and 450 nm for a blue color pixel, and Nx, Ny, Nz 3 After obtaining the dimensional refractive index, the thickness direction retardation value (Rth) is calculated from Equation 1 shown below.
Rth = {(Nx + Ny) / 2−Nz} × d (Formula 1)
In the formula, Nx is a refractive index in the x direction in the plane of the colored pixel layer, Ny is a refractive index in the y direction in the plane of the colored pixel layer, and Nz is a refractive index in the thickness direction of the colored pixel layer. It is a rate, and the slow axis is set so that Nx is Nx ≧ Ny. d is the thickness (nm) of the colored pixel layer.

At this time, when the substrate to be measured is a color filter, the phase difference of the single colored pixel layer is measured by measuring through a mask processed so as to transmit only the single colored pixel layer of R, G, and B. The value can be determined.
Further, for example, when light having a wavelength of 610 nm is used as incident light, the phase difference value caused only by the red colored pixel, in the case of 550 nm, the phase difference value caused only by the green colored pixel, in the case of 450 nm, The approximate value of the single colored pixel layer can be estimated as the phase difference value caused only by the blue colored pixels.
In addition, when the substrate to be measured is a single colored pixel layer of R, G, or B (a configuration in which a coating film of a monochrome color filter coloring composition is formed on a transparent substrate), without using a mask The phase difference can be measured.

The color filter coloring composition used in the present invention has an organic pigment dispersed in at least an organic solvent, a photopolymerizable initiator, or a curing agent based on a polymer or monomer such as an acrylic resin or a cardo resin that can easily ensure high contrast. It is a liquid coating solution.
The color filter of this invention can process the coloring composition to be used as a color resist used for well-known photolithography, or as inks, such as an inkjet and printing.
In addition, the detail about the component as a coloring composition used for a color filter is mentioned later.

The retardation adjustment in the present invention is an additive that can adjust the thickness direction retardation of a color filter formed as a colored coating on a transparent substrate, a reflective substrate, or a semiconductor substrate using a color filter coloring composition.
Particularly for the purpose of improving oblique visibility, the retardation adjusting agent is added to one or more color filter coloring compositions.
The compound used is preferably an organic compound with good dispersibility in order to ensure a high contrast of 1000 or 3000 or more.
Specifically, particles in the form of particles, such as inorganic substances, can be used, but it is better to avoid them from the viewpoints of light scattering and depolarization.
In addition, when a multi-color filter is formed on a transparent substrate or the like, it may be added to all colors, but it can be added to only one or two colors.

The retardation adjusting agent in the present invention may be an organic compound that can adjust the retardation in the increasing direction.
Specifically, one or more selected from an organic compound having a planar structure group having one or more crosslinkable groups, a melamine resin, a porphyrin compound, and a polymerizable liquid crystal compound may be selected.

Usually, it is considered that the retardation in the thickness direction of the entire film can be canceled only by adding particles having a planar structure group having birefringence opposite to that of pigment or other resin.
However, simply adding particles having a planar structure group will cause the particles themselves to be randomly oriented, and the influence on the thickness direction retardation of the entire film will be small.
As a result of intensive investigations, the present inventors have found that by providing at least one crosslinkable group of the planar structure group, the thickness direction retardation of the entire film is greatly changed and exhibits a sufficient effect. It was.
That is, for example, by having a functional group that crosslinks in the photo-curing process or photo-curing process in the photolithography process, the planar structural group does not rotate freely, and the planar structural group is more susceptible to shrinkage during thermal curing. By being easily oriented and fixed in the same direction, the function of phase difference control can be effectively expressed.

  As the planar structural group, it has at least one aromatic ring, and in the case of monocyclic hydrocarbon, phenyl group, cumenyl group, mesityl group, tolyl group, xylyl group, benzyl group, phenethyl group, styryl group, For polycyclic hydrocarbons such as cinnamyl and trityl groups, pentarenyl, indenyl, naphthyl, biphenylene, acenaphthylene, fluorene, phenanthryl, anthracene, triphenylene, pyrene, naphthacene, pentaphen, pentacene Known compounds such as a group, a tetraphenylene group, and a trinaphthylene group can be used. For heteromonocyclic compounds, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, pyrazinyl group, triazine group, etc.For heteropolycyclic compounds, indolizinyl group, isoindolyl group, indolyl group, purinyl group, quinolyl group, isoquinolyl group, phthalazinyl Groups, naphthyridinyl groups, quinoxalinyl groups, cinolinyl groups, carbazolyl groups, carbolinyl groups, acridinyl groups, porphyrin groups, and the like, which have substituents such as hydrocarbon groups and halogen groups Also good.

Examples of at least one crosslinkable group attached to the planar structure group include unsaturated polymerizable groups (A, B, C, D, E, F) or functional groups (I, J, K, L, M, N, O) or a thermally polymerizable group (G, H, P, Q, R, S, T, U) is preferable, and an epoxy group (G, H) is more preferably used. ~ U is most preferably used.
Further, the unsaturated polymerizable group is more preferably an ethylenically unsaturated polymerizable group (A, B, C, D), and —CH ₂ NHCOCH═CH ₂ , —CH ₂ NHCO (CH ₂ ). ₇ CH═CH (CH ₂ ) ₇ CH ₃ , —OCO (C ₆ H ₄ ) O (CH ₂ ) ₆ CH═CH _{2 and the} like are also preferably used.
These crosslinkable groups are glycidyl (meth) acrylate, 2- (meth) acryloyloxyisocyanate, tolylene-2, 4-, when the planar structural group has at least one reactive functional group such as a hydroxyl group. It can be easily obtained by reacting a functional group that reacts with the reactive functional group such as diisocyanate and a compound having an ethylenically unsaturated group by a known method.

As the melamine compound, a commercially available compound represented by the following general formula (2) can be preferably used, but any compound having the above-mentioned planar structure group may be used, and a known compound can be used. Examples of melamine compounds are given below.

In the formula, R ¹ , R ² and R ³ are each a hydrogen atom, methylol group, alkoxymethyl group, alkoxy n-butyl group, R ⁴ , R ⁵ and R ⁶ are each a methylol group, alkoxymethyl group and alkoxy n-butyl. It is a group. A copolymer combining two or more kinds of repeating units may be used. Two or more homopolymers or copolymers may be used in combination.

In addition to the above, compounds having a 1,3,5-triazine ring, for example, those described in JP-A No. 2001-166144 can be used. Further, a compound represented by the following general formula (3) is also preferably used.

R ₇ to R ₁₄ are each independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, and particularly preferably a hydrogen atom.

Alternatively, a compound having a porphyrin skeleton represented by the following general formula (4) can be preferably used. n is an integer of 1 to 20, and 2 is preferably used.

In the formula, each of R _{15 to} R ₂₂ is independently a hydrogen atom, a halogen atom, an alkoxy group, an alkylthio group, a substituted or unsubstituted phenoxy group, a substituted or unsubstituted naphthoxy group, a substituted or unsubstituted phenylthio group, or a substituted group Alternatively, it represents an unsubstituted naphthylthio group.

Specific examples of the porphyrin compound represented by the general formula (4) used in the present invention are described below. Examples of the halogen atom in R _{15 to} R ₂₂ include fluorine, chlorine, bromine and iodine.
The alkoxy group and thioalkyl group are not particularly limited, but the alkyl group in the substituent is preferably a linear, branched or cyclic alkyl group having 1 to 12 carbon atoms, and having 1 to 8 carbon atoms. A linear, branched or cyclic alkyl group is particularly preferred. Z represents —CH ₂ — or —N—.

  Specific examples of the alkyl group in the alkoxy group and thioalkyl group include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, t-butyl group. Group, n-pentyl group, iso-pentyl group, 2-methylbutyl group, 1-methylbutyl group, neo-pentyl group, 1,2-dimethylpropyl group, 1,1-dimethylpropyl group, cyclopentyl group, n-hexyl group 4-methylpentyl group, 3-methylpentyl group, 2-methylpentyl group, 1-methylpentyl group, 3,3-dimethylbutyl group, 2,3-dimethylbutyl group, 1,3-dimethylbutyl group, 2 , 2-dimethylbutyl group, 1,2-dimethylbutyl group, 1,1-dimethylbutyl group, 3-ethylbutyl group, 2-ethylbutyl group, 1-ethyl Tyl group, 1,2,2-trimethylbutyl group, 1,1,2-trimethylbutyl group, 1-ethyl-2-methylpropyl group, cyclohexyl group, n-heptyl group, 2-methylhexyl group, 3-methyl Hexyl group, 4-methylhexyl group, 5-methylhexyl group, 2,4-dimethylpentyl group, n-octyl group, 2-ethylhexyl group, 2,5-dimethylhexyl group, 2,5,5-trimethylpentyl group 2,4-dimethylhexyl group, 2,2,4-trimethylpentyl group, n-octyl group, 3,5,5-trimethylhexyl group, n-nonyl group, n-decyl group, 4-ethyloctyl group, 4-ethyl-4,5-dimethylhexyl group, n-undecyl group, n-dodecyl group, 1,3,5,7-tetraethyloctyl group, 4-butyloctyl group, 6,6-di- Tyloctyl group, n-tridecyl group, 6-methyl-4-butyloctyl group, n-tetradecyl group, n-pentadecyl group, 3,5-dimethylheptyl group, 2,6-dimethylheptyl group, 2,4-dimethylheptyl Group, 2,2,5,5-tetramethylhexyl group, 1-cyclopentyl-2,2-dimethylpropyl group, 1-cyclohexyl-2,2-dimethylpropyl group and the like.

  Specific examples of the substituted or unsubstituted phenoxy group include phenoxy group, 2-methylphenoxy group, 3-methylphenoxy group, 4-methylphenoxy group, 2-ethylphenoxy group, 3-ethylphenoxy group, 4-ethyl. Examples include phenoxy group, 2,4-dimethylphenoxy group, 3,4-dimethylphenoxy group, 4-t-butylphenoxy group, 4-aminophenoxy group, 4-dimethylaminophenoxy group, 4-diethylaminophenoxy group and the like.

  Specific examples of the substituted or unsubstituted naphthoxy group include 1-naphthoxy group, 2-naphthoxy group, nitronaphthoxy group, cyanonaphthoxy group, hydroxynaphthoxy group, methylnaphthoxy group, trifluoromethylnaphthoxy group and the like. .

  Specific examples of the substituted or unsubstituted phenylthio group include a phenylthio group, a 2-methylphenylthio group, a 3-methylphenylthio group, a 4-methylphenylthio group, a 2-ethylphenylthio group, and a 3-ethylphenylthio group. Group, 4-ethylphenylthio group, 2,4-dimethylphenylthio group, 3,4-dimethylphenylthio group, 4-t-butylphenylthio group, 4-aminophenylthio group, 4-dimethylaminophenylthio group , 4-diethylaminophenylthio group and the like.

  Specific examples of the substituted or unsubstituted naphthylthio group include 1-naphthylthio group, 2-naphthylthio group, nitronaphthylthio group, cyanonaphthylthio group, hydroxynaphthylthio group, methylnaphthylthio group, trifluoromethylnaphthylthio group. Etc.

  X may be a combination of two or more compounds (for example, a compound having a 1,3,5-triazine ring and a compound having a porphyrin skeleton).

Examples of the plane-containing structural group epoxy compound include bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, bisphenol AD type epoxy compounds, hydrogenated bisphenol A type epoxy compounds and the like; for example, phenol novolac type Epoxy compounds, novolak-type epoxy compounds such as cresol novolak-type epoxy compounds; for example, glycidylamines such as tetraglycidyldiaminodiphenylmethane, triglycidyl-p-aminophenol, triglycidyl-m-aminophenol, tetraglycidyl-m-xylenediamine Epoxy compounds; for example, glycidyl ester epoxy compounds such as diglycidyl phthalate, diglycidyl hexahydrophthalate, diglycidyl tetrahydrophthalate ; For example, triglycidyl isocyanurate, etc. complex Kaeshiki epoxy compounds such as glycidyl glycidoxy Arch setup in can be exemplified. An example is shown in general formula (5).

As the polymerizable liquid crystal compound, a rod-like liquid crystal molecule or a discotic liquid crystal molecule can be applied, and a discotic liquid crystal molecule is particularly preferable. As the rod-like liquid crystalline molecules, liquid crystalline molecules described in JP-A-2006-16599 can be employed. For example, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoates, cyclohexanecarboxylic acid Phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are also used. As the discotic liquid crystalline molecules, for example, those described in JP-A-8-27284 can be used. Examples thereof are shown in Table 2 below.

In Table 2, Y is a divalent linking group selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, —CO—, —NH—, —O—, —S—, and combinations thereof, and Most preferably, the group is a combination of at least two divalent groups.
The alkylene group preferably has 1 to 12 carbon atoms, the alkenylene group preferably has 2 to 12 carbon atoms, and the arylene group preferably has 6 to 10 carbon atoms. .
The alkylene group, alkenylene group and arylene group may have a substituent (eg, alkyl group, halogen atom, cyano, alkoxy group, acyloxy group).
R represents an unsaturated polymerizable group (A, B, C, D, E, F) or a functional group (I, J, K, L, M, N, O) or a thermally polymerizable group ( At least one crosslinkable group selected from G, H, P, Q, R, S, T, U), or an alkyl group, an alkenyl group, an aryl group, or a heterocyclic group substituted with the crosslinkable group is there. The unsaturated polymerizable group is more preferably an ethylenically unsaturated polymerizable group (A, B, C, D), and —CH 2 NHCOCH═CH 2, —CH 2 NHCO (CH 2) 7 CH═CH (CH 2) 7 CH 3, -OCO (C6H4) O (CH2) 6CH = CH2 or the like is also preferably used.

  Next, the color filter of the present invention will be described.

As shown in FIG. 1, the color filter of the present invention comprises a black matrix 2 which is a light shielding layer on a glass substrate 1, and at least 3 of red 3 (R), green 3 (G) and blue 3 (B). Colored pixels 3 are provided.
The color filter is not limited to these three colors, and may be a combination of complementary colors, or may be a multi-color filter of three or more colors including complementary colors and other colors.

Usually, the absolute value of the birefringence of the color filter is 0.01 or less, that is, the thickness direction retardation value (Rth) is unlimited, Rth (R) = Rth (G)) = Rth (B) = 0 It is desirable to be close to.
However, as a result of intensive studies by the present inventors, when combined with a component other than a color filter, for example, wavelength dispersion of phase difference, other than Rth (R) = Rth (G)) = Rth (B) = 0 We have found that there is a value for the thickness direction retardation of the optimal color filter.

The most desirable value of the phase difference value Rth of each colored pixel in the color filter varies depending on the combination with other members, but the important thing is that the Rth of the green pixel is larger than the red pixel. Regardless, the combination where the Rth of the blue pixel is smaller than the green pixel ”or“ the combination where the Rth of the blue pixel is larger than the green pixel despite the Rth of the green pixel being smaller than the red pixel ” Is that good oblique visibility cannot be obtained.
This is because, in a member typified by a retardation plate used in a liquid crystal display device, the birefringence wavelength dispersibility changes in one direction (continuously) with respect to the wavelength of transmitted light. Therefore, it is necessary to select a combination that obtains optimal oblique visibility among optical member combinations of liquid crystal display devices such as a liquid crystal, a polarizing plate, a retardation plate, and an alignment film. (C / CS)

For example, C.I. I. Pigment Red 7, 14, 41, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 81: 4, 146, 168, 177, 178, 179, 184, 185, Red pigments such as 187, 200, 202, 208, 210, 246, 254, 255, 264, 270, 272, and 279 can be used, and a yellow pigment and an orange pigment can also be used in combination.
Examples of yellow pigments include C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1, 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 93, 94, 95, 97, 98, 100, 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 126, 127, 128, 129, 147, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 179, 180, 181, 182, 187 188,193,194,199,198,213,214, and the like. Examples of the orange pigment include C.I. I. Pigment Orange 36, 43, 51, 55, 59, 61, 71, 73 and the like.

When the red pixel contains one or more of diketopyrrolopyrrole red pigments and anthraquinone red pigments among these pigments, it is preferable because any Rth can be easily obtained.
This is because the diketopyrrolopyrrole red pigment can be made positive or negative and the absolute value thereof can be controlled to some extent by devising the finer treatment, and the anthraquinone red pigment is This is because it is easy to obtain Rth close to 0 regardless of the miniaturization process.
The amount used is 10 to 90% by weight of the diketopyrrolopyrrole red pigment and 5 to 70% by weight of the anthraquinone red pigment based on the total weight of the pigment. From the viewpoint of contrast and the like, in particular, when focusing on the contrast, it is more preferable that the diketopyrrolopyrrole red pigment is 25 to 75% by weight and the anthraquinone red pigment is 30 to 60% by weight.

The red pixel can contain a yellow pigment or an orange pigment for the purpose of adjusting the hue, but it is preferable to use an azo metal complex-based yellow pigment from the viewpoint of high contrast.
The amount used is preferably 5 to 25% by weight based on the total weight of the pigment, and if it is less than 5% by weight, hue adjustment such as sufficient brightness improvement cannot be achieved, and the amount exceeds 30% by weight. In this case, since the hue is shifted too yellow, the color reproducibility is deteriorated.

  In the above, examples of the diketopyrrolopyrrole red pigment include C.I. I. Pigment Red 254, an anthraquinone red pigment, "C.I. I. Pigment Red 177, an azo metal complex yellow pigment such as C.I. I. Pigment Yellow 150 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

  For example, C.I. I. Pigment Green 7, 10, 36, 37 or the like can be used, and a yellow pigment can be used in combination. As the yellow pigment, the same pigments as those mentioned for the red pixel can be used.

The amount used is 30 to 90% by weight of the halogenated metal phthalocyanine green pigment, 5 to 60% by weight of the azo yellow pigment, and 5 to 60% by weight of the quinophthalone yellow pigment based on the total weight of the pigment. This is preferable from the viewpoint of the hue, brightness, and film thickness of the pixel. More preferably, the halogenated metal phthalocyanine green pigment is 50 to 85% by weight, the azo yellow pigment is 5 to 45% by weight, and the quinophthalone yellow pigment is 5 to 45% by weight.

  In the above, examples of the halogenated metal phthalocyanine green pigment include C.I. I. Pigment Green 7, 36, and azo yellow pigments include C.I. I. Pigment Yellow 150 and quinophthalone yellow pigments include C.I. I. Pigment Yellow 138 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

  Examples of blue pixels include C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, and the like can be used, and a purple pigment can be used in combination. Examples of purple pigments include C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like.

When the blue pixel contains one or more of a metal phthalocyanine blue pigment and a dioxazine purple pigment among these pigments, it is easy to obtain Rth close to 0.
The amount used is 40 to 100% by weight of the metal phthalocyanine blue pigment and 1 to 50% by weight of the dioxazine violet pigment based on the total weight of the pigment. It is preferable from a point, Furthermore, it is more preferable to make a metal phthalocyanine blue pigment 50 to 98 weight% and a dioxazine purple pigment 2 to 25 weight%.

  In the above, examples of the metal phthalocyanine blue pigment include C.I. I. Pigment Blue 15: 6, and dioxazine-based purple pigments include C.I. I. Pigment Violet 23 is preferable in terms of excellent light resistance, heat resistance, transparency, coloring power, and the like.

Inorganic pigments include yellow lead, zinc yellow, red bean (red iron (III) oxide), cadmium red, ultramarine blue, bitumen, chromium oxide green, cobalt green and other metal oxide powders, metal sulfide powders, metal powders Etc.
Inorganic pigments are used in combination with organic pigments in order to ensure good coatability, sensitivity, developability and the like while maintaining a balance between saturation and lightness. Furthermore, for color matching, a dye can be contained within a range that does not lower the heat resistance.

  The pigment contained in the colored pixel is preferably miniaturized and preferably has a small average primary particle size in order to achieve high brightness and high contrast of the color filter. The average primary particle diameter of the pigment can be calculated by taking the pigment with a transmission electron microscope and analyzing the image of the photograph.

The average primary particle diameter of the pigment is preferably 40 nm or less, more preferably 30 nm or less, and still more preferably 20 nm or less. Moreover, it is preferable that an average primary particle diameter is 5 nm or more. When the average primary particle diameter of the pigment is larger than the upper limit value, the visibility of the liquid crystal display device during black display is poor. Moreover, when smaller than a lower limit, pigment dispersion | distribution becomes difficult, it becomes difficult to maintain stability as a coloring composition and to ensure fluidity | liquidity.
As a result, the luminance and color characteristics of the color filter are deteriorated. In particular, an organic pigment having an average primary particle diameter exceeding 40 μm adversely affects front visibility.

In addition, each color pixel formed on the transparent substrate is sandwiched between two polarizing plates, a backlight is applied from one polarizing plate side, and the light transmitted through the other polarizing plate is measured with a luminance meter. The contrast C calculated from the ratio of the light luminance (Lp) in the parallel state and the light luminance (Lc) in the orthogonal state is calculated from C = Lp / Lc, CS is only the substrate without colored pixels, and CR is When red pixel, CG represents green pixel, and CB represents blue pixel contrast, CR / CS> 0.45, CG / CS> 0.45, and CB / CS> 0.45, As shown in Table 6, the front visibility at the time of black display of the liquid crystal display device is excellent.
That is, it is possible to reproduce a tight black display with little light leakage.
When CR / CS> 0.45, CG / CS> 0.45, and CB / CS> 0.45 are not satisfied, that is, CR / CS ≦ 0.45 or CG / CS ≦ 0. In the case of 45 or CB / CS ≦ 0.45, light leakage during black display increases and a liquid crystal display device with excellent front visibility cannot be obtained.
Furthermore, by reducing the retardation difference for each color, a liquid crystal display device having excellent oblique visibility and front visibility is obtained. Even if CR / CS> 0.45, CG / CS> 0.45, and CB / CS> 0.45 are satisfied, if the retardation difference for each color is large, the oblique visibility is insufficient. Sometimes. This is shown in Table 8, Comparative Example 6, in which the retardation increasing agent of the present invention is not added to the green pixel.

  Means for controlling the average primary particle diameter and thickness direction retardation of the pigment include a method in which the pigment is mechanically pulverized to control the primary particle diameter and particle shape (called a grinding method), and a solution in a good solvent. A method in which a pigment having a desired primary particle size and particle shape is deposited by introducing it into a poor solvent (referred to as a precipitation method), and a method for producing a pigment having a desired primary particle size and particle shape at the time of synthesis (referred to as a synthetic precipitation method) ) Etc. Depending on the synthesis method and chemical properties of the pigment to be used, an appropriate method can be selected for each pigment.

  Each method will be described below, and any of the above methods may be used as a method for controlling the primary particle diameter and particle shape of the pigment contained in the colored pixel layer constituting the color filter of the present invention.

  In the grinding method, the pigment is mechanically kneaded using a ball mill, sand mill or kneader together with a grinding agent such as water-soluble inorganic salt such as salt and a water-soluble organic solvent that does not dissolve it. This is a method of obtaining a pigment having a desired primary particle size and particle shape by washing and removing the inorganic salt and the organic solvent, followed by drying. However, since the pigment may crystallize by the salt milling treatment, a method of preventing crystal growth by adding a solid resin or a pigment dispersant that is at least partially dissolved in the organic solvent during the treatment is effective.

As for the ratio of the pigment to the inorganic salt, if the ratio of the inorganic salt is increased, the efficiency of refining the pigment is improved, but the productivity is lowered because the amount of pigment processed is reduced.
In general, 1 to 30 parts by weight, preferably 2 to 20 parts by weight of the inorganic salt is used per 1 part by weight of the pigment. The water-soluble organic solvent is added so that the pigment and the inorganic salt are uniformly solidified. Although depending on the blending ratio of the pigment and the inorganic salt, the water-soluble organic solvent is usually added in an amount of 0.1% by weight with respect to 1 part by weight of the pigment. Used in an amount of 5 to 30 parts by weight.
More specifically, with respect to the above grinding method, a small amount of a water-soluble organic solvent is added as a wetting agent to a mixture of a pigment and a water-soluble inorganic salt, and after kneading with a kneader or the like, the mixture is poured into water. Stir with a speed mixer to make a slurry. Next, this slurry is filtered, washed with water, and dried to obtain a pigment having a desired primary particle size and particle shape.

The precipitation method is a method in which a pigment is dissolved in an appropriate good solvent and then mixed with a poor solvent to precipitate a pigment having a desired primary particle size and particle shape. The type and amount of the solvent, the precipitation temperature, and the precipitation rate. The primary particle size and particle shape can be controlled by the above.
In general, pigments are difficult to dissolve in solvents, so the solvents that can be used are limited, but examples include strongly acidic solvents such as concentrated sulfuric acid, polyphosphoric acid, chlorosulfonic acid, or basic solvents such as liquid ammonia, dimethylformamide solution of sodium methylate, etc. It has been known.

A typical example of this method is an acid pasting method in which a solution in which a pigment is dissolved in an acidic solvent is poured into another solvent and reprecipitated to obtain fine particles. Industrially, a method of injecting a sulfuric acid solution into water is generally used from the viewpoint of cost.
The sulfuric acid concentration is not particularly limited, but is preferably 95 to 100% by weight. The amount of sulfuric acid used with respect to the pigment is not particularly limited. However, if the amount is too small, the solution viscosity is high and handling becomes bad. Conversely, if the amount is too large, the treatment efficiency of the pigment is lowered. It is preferable.
The pigment need not be completely dissolved. The temperature at the time of dissolution is preferably from 0 to 50 ° C. Below this temperature, sulfuric acid may freeze and the solubility will be low. If the temperature is too high, side reactions tend to occur.
The temperature of the water to be injected is preferably 1 to 60 ° C., and if the injection is started at a temperature higher than this temperature, it boils with the heat of dissolution of sulfuric acid, which is dangerous. It will freeze at temperatures below this. The injection time is preferably 0.1 to 30 minutes with respect to 1 part of the pigment. As the time increases, the primary particle size tends to increase.

The primary particle size and particle shape of the pigment can be controlled while considering the size adjustment of the pigment by selecting a method that combines a precipitation method such as the acid pasting method and a grinding method such as the salt milling method. Further, it is more preferable because the fluidity as a dispersion can be secured at this time.
During salt milling or acid pasting, in order to prevent aggregation of pigments accompanying primary particle size and particle shape control, the following pigment derivatives, resin type pigment dispersants, surfactants and other dispersing aids may be used in combination. it can. Further, by controlling the primary particle size and particle shape in the form of coexistence of two or more pigments, even a pigment that is difficult to disperse alone can be finished as a stable dispersion.

  There is a leuco method as a special precipitation method. When a vat dye, such as a flavantron, perinone, perylene, or indanthrone, is reduced with alkaline hydrosulfite, the quinone group becomes a hydroquinone sodium salt (leuco compound) and becomes water-soluble. A pigment having a small primary particle size insoluble in water can be precipitated by adding an appropriate oxidizing agent to the aqueous solution for oxidation.

  The synthetic precipitation method is a method in which a pigment having a desired primary particle size and particle shape is precipitated simultaneously with the synthesis of the pigment. However, when the produced fine pigment is taken out of the solvent, if the pigment particles are not aggregated into large secondary particles, filtration, which is a general separation method, becomes difficult. It is applied to azo pigments synthesized in water.

  Furthermore, as a means for controlling the primary particle size and particle shape of the pigment, the primary particle size of the pigment is reduced by dispersing the pigment for a long time with a high-speed sand mill or the like (so-called dry milling method in which the pigment is dry pulverized). It is also possible to disperse at the same time.

  Below, the coloring composition used in order to form each color pixel of the color filter of this invention is demonstrated.

  The pigment carrier contained in the coloring composition used for forming each color pixel is for dispersing the pigment, and is composed of a transparent resin, a precursor thereof, or a mixture thereof.

The transparent resin is a resin having a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of 400 to 700 nm in the visible light region.
The transparent resin includes a thermoplastic resin, a thermosetting resin, and a photosensitive resin, and its precursor includes a monomer or an oligomer that is cured by irradiation with radiation to form a transparent resin. Alternatively, two or more kinds can be mixed and used.

The pigment carrier can be used in an amount of 30 to 700 parts by weight, preferably 60 to 450 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.
When a mixture of a transparent resin and its precursor is used as a pigment carrier, the transparent resin is 20 to 400 parts by weight, preferably 50 to 250 parts by weight, based on 100 parts by weight of the pigment in the coloring composition. Can be used.
The precursor of the transparent resin can be used in an amount of 10 to 300 parts by weight, preferably 10 to 200 parts by weight, with respect to 100 parts by weight of the pigment in the coloring composition.

  Examples of the thermoplastic resin include butyral resin, styrene-maleic acid copolymer, chlorinated polyethylene, chlorinated polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyurethane resin, and polyester resin. And acrylic resins, alkyd resins, polystyrene resins, polyamide resins, rubber resins, cyclized rubber resins, celluloses, polybutadiene, polyethylene, polypropylene, polyimide resins, and the like.

  Examples of the thermosetting resin include epoxy resins, benzoguanamine resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, melamine resins, urea resins, and phenol resins.

Examples of the photosensitive resin include (meth) acrylic compounds having a reactive substituent such as an isocyanate group, an aldehyde group, and an epoxy group on a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group, or an amino group, A resin obtained by reacting an acid and introducing a photocrosslinkable group such as a (meth) acryloyl group or a styryl group into the linear polymer is used.
Further, a linear polymer containing an acid anhydride such as a styrene-maleic anhydride copolymer or an α-olefin-maleic anhydride copolymer is converted into a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate. Half-esterified products are also used.

  Monomers and oligomers that are precursors of transparent resins include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth) acrylate, pentaerythritol tri (meth) ) Acrylate, trimethylolpropane tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate, melamine (meth) acrylate, various acrylic esters such as epoxy (meth) acrylate and methacrylic acid Examples thereof include esters, (meth) acrylic acid, styrene, vinyl acetate, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, and acrylonitrile. These can be used alone or in admixture of two or more.

When the composition is cured by ultraviolet irradiation, a photopolymerization initiator or the like is added to the coloring composition.
Examples of the photopolymerization initiator include 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- Hydroxycyclohexyl phenyl ketone, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane- Acetophenone photopolymerization initiators such as 1-one, benzoin photopolymerization initiators such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzyldimethyl ketal, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4 -F Benzophenone photopolymerization initiators such as nylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4′-methyldiphenyl sulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone Thioxanthone photopolymerization initiators such as 2,4,6-trichloro-s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2- (p-methoxyphenyl) -4, 6-bis (trichloromethyl) -s-triazine, 2- (p-tolyl) -4,6-bis (trichloromethyl) -s-triazine, 2-piperonyl-4,6-bis (trichloromethyl) -s- Triazine, 2,4-bis (trichloro Til) -6-styryl-s-triazine, 2- (naphth-1-yl) -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxy-naphth-1-yl) -4 , 6-Bis (trichloromethyl) -s-triazine, 2,4-trichloromethyl- (piperonyl) -6-triazine, 2,4-trichloromethyl (4′-methoxystyryl) -6-triazine, etc. A polymerization initiator, a borate photopolymerization initiator, a carbazole photopolymerization initiator, an imidazole photopolymerization initiator, or the like is used.
A photoinitiator can be used in the amount of 5-200 weight part with respect to 100 weight part of pigments in a coloring composition, Preferably it is 10-150 weight part.

The above photopolymerization initiators are used alone or in combination of two or more. As sensitizers, α-acyloxy ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthrenequinone. , Camphorquinone, ethylanthraquinone, 4,4′-diethylisophthalophenone, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, 4,4′-diethylaminobenzophenone, etc. It can also be used together.
The sensitizer can be contained in an amount of 0.1 to 60 parts by weight with respect to 100 parts by weight of the photopolymerization initiator.

Furthermore, the coloring composition can contain a polyfunctional thiol that functions as a chain transfer agent. The polyfunctional thiol may be a compound having two or more thiol groups. For example, hexanedithiol, decanedithiol, 1,4-butanediol bisthiopropionate, 1,4-butanediol bisthioglycolate, ethylene Glycol bisthioglycolate, ethylene glycol bisthiopropionate, trimethylolpropane tristhioglycolate, trimethylolpropane tristhiopropionate, trimethylolpropane tris (3-mercaptobutyrate), pentaerythritol tetrakisthioglycolate, Pentaerythritol tetrakisthiopropionate, trimercaptopropionic acid tris (2-hydroxyethyl) isocyanurate, 1,4-dimethylmercaptobenzene, 2,4,6-trimerca DOO -s- triazine, 2- (N, N- dibutylamino) -4,6-dimercapto -s- triazine. These polyfunctional thiols can be used alone or in combination.
The polyfunctional thiol can be used in an amount of 0.2 to 150 parts by weight, preferably 0.2 to 100 parts by weight, with respect to 100 parts by weight of the pigment in the coloring composition.

In addition, a solvent is used to facilitate the formation of a filter segment by sufficiently dispersing the pigment in a pigment carrier and applying it on a transparent substrate such as a glass substrate so that the dry film thickness is 0.2 to 5 μm. Can be contained. Examples of the solvent include cyclohexanone, ethyl cellosolve acetate, butyl cellosolve acetate, 1-methoxy-2-propyl acetate, diethylene glycol dimethyl ether, ethylbenzene, ethylene glycol diethyl ether, xylene, ethyl cellosolve, methyl-n amyl ketone, propylene glycol monomethyl ether, toluene, Examples include methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent, and the like. These may be used alone or in combination.
The solvent can be used in an amount of 800 to 4000 parts by weight, preferably 1000 to 2500 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

  The coloring composition comprises one or more pigments, if necessary, together with the above photopolymerization initiator, in a pigment carrier and an organic solvent, such as a three roll mill, a two roll mill, a sand mill, a kneader, and an attritor. It can be manufactured using dispersion means. Moreover, the coloring composition containing 2 or more types of pigments can also be manufactured by mixing each pigment separately finely dispersed in a pigment carrier and an organic solvent.

When the pigment is dispersed in the pigment carrier and the organic solvent, a dispersion aid such as a resin-type pigment dispersant, a surfactant, or a pigment derivative can be appropriately contained.
Since the dispersion aid is excellent in pigment dispersion and has a great effect of preventing re-aggregation of the pigment after dispersion, a coloring composition comprising a pigment dispersed in a pigment carrier and an organic solvent using a dispersion aid is used. If so, a color filter excellent in transparency can be obtained. The dispersion aid can be used in an amount of 0.1 to 40 parts by weight, preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

The resin-type pigment dispersant has a pigment-affinity part that has the property of adsorbing to the pigment and a part that is compatible with the pigment carrier, and adsorbs to the pigment to stabilize the dispersion of the pigment on the pigment carrier. It works.
Specific examples of resin-type pigment dispersants include polycarboxylic acid esters such as polyurethane and polyacrylate, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, and polycarboxylic acid alkylamines. Salts, polysiloxanes, long-chain polyaminoamide phosphates, hydroxyl group-containing polycarboxylic acid esters, their modified products, amides formed by the reaction of poly (lower alkyleneimines) with polyesters having free carboxyl groups, and the like Water-based dispersants such as oily dispersants such as salts, (meth) acrylic acid-styrene copolymers, (meth) acrylic acid- (meth) acrylic acid ester copolymers, styrene-maleic acid copolymers, polyvinyl alcohol, polyvinylpyrrolidone Resin, water-soluble polymer, polyester Modified polyacrylate, ethylene oxide / propylene oxide addition compound, phosphate ester-based and the like are used, they can be used alone or in admixture of two or more.

  Surfactants include polyoxyethylene alkyl ether sulfate, sodium dodecylbenzenesulfonate, alkali salt of styrene-acrylic acid copolymer, sodium alkylnaphthalenesulfonate, sodium alkyldiphenyletherdisulfonate, lauryl sulfate monoethanolamine, lauryl Anionic surfactants such as triethanolamine sulfate, ammonium lauryl sulfate, monoethanolamine stearate, sodium stearate, sodium lauryl sulfate, monoethanolamine of styrene-acrylic acid copolymer, polyoxyethylene alkyl ether phosphate; Polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Nonionic surfactants such as alkyl ether phosphates, polyoxyethylene sorbitan monostearate, and polyethylene glycol monolaurate; chaotic surfactants such as alkyl quaternary ammonium salts and their ethylene oxide adducts; alkyldimethylamino Examples include amphoteric surfactants such as alkylbetaines such as betaine acetate and alkylimidazolines, and these can be used alone or in admixture of two or more.

The dye derivative is a compound in which a substituent is introduced into an organic dye, and is preferably close to the hue of the pigment to be used. However, if the addition amount is small, those having different hues may be used.
Organic dyes also include light yellow aromatic polycyclic compounds such as naphthalene and anthraquinone that are not generally called dyes. Examples of the dye derivatives are described in JP-A-63-305173, JP-B-57-15620, JP-B-59-40172, JP-B-63-17102, JP-B-5-9469, and the like. You can use what you have. In particular, a pigment derivative having a basic group is preferably used because it has a large pigment dispersion effect. These can be used alone or in admixture of two or more.

  The coloring composition can contain a storage stabilizer in order to stabilize the viscosity with time of the composition. Examples of storage stabilizers include quaternary ammonium chlorides such as benzyltrimethyl chloride and diethylhydroxyamine, organic acids such as lactic acid and oxalic acid, and organic acids such as methyl ether, t-butylpyrocatechol, tetraethylphosphine, and tetraphenylphosphine. Examples thereof include phosphine and phosphite. The storage stabilizer can be contained in an amount of 0.1 to 10 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

In addition, the coloring composition may contain an adhesion improving agent such as a silane coupling agent in order to improve the adhesion to the substrate.
Examples of the silane coupling agent include vinyl silanes such as vinyltris (β-methoxyethoxy) silane, vinylethoxysilane, and vinyltrimethoxysilane, (meth) acrylsilanes such as γ-methacryloxypropyltrimethoxysilane, β- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) methyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) ) Epoxysilanes such as methyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, N-β ( Aminoethyl) γ-aminopro Lutriethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldiethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N Examples include aminosilanes such as -phenyl-γ-aminopropyltriethoxysilane, thiosilanes such as γ-mercaptopropyltrimethoxysilane, and γ-mercaptopropyltriethoxysilane. The silane coupling agent can be contained in an amount of 0.01 to 100 parts by weight with respect to 100 parts by weight of the pigment in the coloring composition.

The coloring composition can be prepared in the form of gravure offset printing ink, waterless offset printing ink, inkjet ink, silk screen printing ink, solvent development type or alkali development type color resist. The colored resist is obtained by dispersing a dye in a composition containing a thermoplastic resin, a thermosetting resin or a photosensitive resin, a monomer, a photopolymerization initiator, and an organic solvent.
The pigment is preferably contained in a proportion of 5 to 70% by weight based on the total solid content of the colored composition (100% by weight). More preferably, it is contained in a proportion of 20 to 50% by weight, and the remainder consists essentially of a resinous binder provided by a pigment carrier.
The colored composition is removed by means of centrifugal separation, sintering filter, membrane filter, etc. to remove coarse particles of 5 μm or more, preferably coarse particles of 1 μm or more, more preferably 0.5 μm or more and coarse particles It is preferable to carry out.

  The red pixel, the green pixel, and the blue pixel in the color filter of the present invention are formed on the transparent substrate by using the above-described colored compositions by a printing method or a photolithography method.

  As the transparent substrate, glass plates such as soda lime glass, low alkali borosilicate glass and non-alkali alumino borosilicate glass, and resin plates such as polycarbonate, polymethyl methacrylate, and polyethylene terephthalate are used. In addition, a transparent electrode made of a combination of metal oxides such as indium oxide, tin oxide, zinc oxide and antimony oxide is formed on the surface of the glass plate or resin plate for driving the liquid crystal after the liquid crystal panel is formed. Also good.

  The formation of each color filter segment by the printing method can be patterned simply by repeating the printing and drying of the colored composition prepared as the above-mentioned various printing inks. Therefore, the color filter manufacturing method is low cost and excellent in mass productivity. ing. Furthermore, it is possible to print a fine pattern having high dimensional accuracy and smoothness by the development of printing technology. In order to perform printing, it is preferable that the ink does not dry and solidify on the printing plate or on the blanket. Control of the fluidity of the ink on the printing machine is also important, and the ink viscosity can be adjusted with a dispersant or extender pigment.

  The ink jet method is a method of directly forming a print on a transparent substrate or a substrate on which an active element such as a TFT is formed by an ink jet apparatus in which a plurality of fine discharge ports (ink jet heads) are arranged for each color.

When each color pixel is formed by a photolithography method, the coloring composition prepared as the solvent developing type or alkali developing type coloring resist is applied to a transparent substrate by spray coating, spin coating, slit coating, roll coating, or the like. To apply a dry film thickness of 0.2 to 10 μm.
When drying the coating film, a vacuum dryer, a convection oven, an IR oven, a hot plate, or the like may be used. If necessary, the dried film is exposed to ultraviolet light through a mask having a predetermined pattern provided in contact with or non-contact with the film.
Then, after immersing in a solvent or alkali developer or spraying the developer by spraying or the like to remove the uncured portion to form a desired pattern, the same operation is repeated for other colors to produce a color filter. be able to.
Furthermore, in order to accelerate the polymerization of the colored resist, heating can be performed as necessary. According to the photolithography method, a color filter with higher accuracy than the above printing method can be manufactured.

In development, an aqueous solution such as sodium carbonate or sodium hydroxide is used as an alkali developer, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Moreover, an antifoamer and surfactant can also be added to a developing solution. As a development processing method, a shower development method, a spray development method, a dip (immersion) development method, a paddle (liquid accumulation) development method, or the like can be applied.
In order to increase the UV exposure sensitivity, after coating and drying the colored resist, a water-soluble or alkaline water-soluble resin such as polyvinyl alcohol or a water-soluble acrylic resin is applied and dried to form a film that prevents polymerization inhibition by oxygen. Thereafter, ultraviolet exposure can also be performed.

The color filter of the present invention can be produced by an electrodeposition method, a transfer method, an ink jet method or the like in addition to the above method. The electrodeposition method is a method for producing a color filter by using a transparent conductive film formed on a transparent substrate and forming each color filter segment on the transparent conductive film by electrophoresis of colloidal particles. is there.
The transfer method is a method in which a color filter layer is formed in advance on the surface of a peelable transfer base sheet, and this color filter layer is transferred to a desired transparent substrate.

  Next, a liquid crystal display device provided with the color filter of the present invention will be described.

FIG. 2 is a schematic cross-sectional view of a liquid crystal display device provided with the color filter of the present invention.
A device 4 shown in FIG. 2 is a typical example of a TFT drive type liquid crystal display device for a notebook personal computer, and includes a pair of transparent substrates 5 and 6 disposed so as to be opposed to each other. (LC) is enclosed.
The liquid crystal (LC) is aligned according to liquid crystal alignment modes such as TN (Twisted Nematic), STN (Super Twisted Nematic), IPS (In-Plane Switching), VA (Vertical Alignment), OCB (Optically Compensated Birefringence), etc. .
A TFT (thin film transistor) array 7 is formed on the inner surface of the first transparent substrate 5, and a transparent electrode layer 8 made of, for example, ITO is formed thereon. An alignment layer 9 is provided on the transparent electrode layer 8. Further, on the outer surface of the transparent substrate 5, a polarizing plate 10 including a retardation film is formed.

  On the other hand, the color filter 11 of the present invention is formed on the inner surface of the second transparent substrate 6. The red, green and blue filter segments constituting the color filter 11 are separated by a black matrix (not shown). A transparent protective film (not shown) is formed so as to cover the color filter 11, and further, a transparent electrode layer 12 made of, for example, ITO is formed on the color filter 11, and the alignment layer 13 covers the transparent electrode layer 12. Is provided. A polarizing plate 14 is formed on the outer surface of the transparent substrate 6. A backlight unit 16 including a three-wavelength lamp 15 is provided below the polarizing plate 10.

  As described above, according to the present embodiment, in order to obtain a color filter with higher contrast, by specifying the pigment type to be used or by making the pigment finer, red, green, and Even if the thickness direction retardation value of the blue colored pixel layer may be discontinuous, photopolymerization is performed on at least one planar structure group and at least two different portions of the planar structure group. It is possible to provide a color composition for a color filter that can be adjusted to an optimum value so that the thickness direction retardation value is continuous by using a retardation adjusting agent having a functional group or a thermally polymerizable group. .

Furthermore, by producing a color filter using the coloring composition for a color filter of the present invention, Rth (R) ≧ Rth (G) ≧ Rth (B) or Rth (R) ≦ Rth (G) ≦ Rth ( A continuous color filter in the relationship B) can be obtained.
According to still another aspect of the present invention, when a liquid crystal display is produced using the color filter of the present invention so as to be suitable for the optical characteristics of the optical compensation layer and other components, particularly the wavelength dispersion characteristics of the retardation, Since there is no variation in the polarization state of light passing through the display area of each colored pixel, a liquid crystal display device excellent in viewing angle display from an oblique direction can be obtained. Furthermore, since the display is black with the viewing angle compensated from the oblique direction, when viewed from the oblique direction, the color shift can be reduced, and neutral black can be reproduced, exhibiting excellent display characteristics. Can do.

Hereinafter, embodiments of the present invention will be described with specific examples, but the present invention is not limited to the examples described below. In addition, since the material used in the present invention is extremely sensitive to light, it is necessary to prevent exposure to unnecessary light such as natural light, and it goes without saying that all operations are performed under a yellow or red light.
In the examples and comparative examples, “parts” means “parts by weight”. The symbol of the pigment indicates a color index number. For example, “PR254” represents “CI Pigment Red 254” and “PY150” represents “CI Pigment Yellow 150”.

The dye derivatives used in the following examples are shown in Table 3.

a) Production of refined pigments The refined pigments used in Examples and Comparative Examples were produced by the following method. Then, the obtained pigment was observed with a transmission electron microscope (“JEM-1200EX” manufactured by JEOL Ltd.), and the primary particle diameter of the pigment was calculated by image analysis. The primary particle diameter mentioned here represents a particle diameter (equivalent circle diameter) corresponding to 50% of the total amount in the cumulative curve of the number particle size distribution.

[Production Example 1]
100 parts of diketopyrrolopyrrole red pigment PR254 ("Irgafoa Red B-CF" manufactured by Ciba Specialty Chemicals; R-1), 18 parts of dye derivative (D-1), 1000 parts of ground salt, and 120 parts of diethylene glycol Was charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 60 ° C. for 10 hours.
The mixture was added to 2000 parts of warm water, heated to about 80 ° C. and stirred with a high speed mixer for about 1 hour to form a slurry, filtered and washed repeatedly to remove salt and solvent, and then at 80 ° C. for 24 hours. Dried to obtain 115 parts of salt milled pigment (R-2). Table 4 shows the primary particle diameter of the obtained pigment.

[Production Example 2]
100 parts of anthraquinone red pigment PR177 (“Chromophthal Red A2B” manufactured by Ciba Specialty Chemicals), 8 parts of a dye derivative (D-2), 700 parts of crushed salt, and 180 parts of diethylene glycol are made of 1 gallon kneader made of stainless steel (Inoue Seisakusho) And kneaded at 70 ° C. for 4 hours. The mixture was put into 4000 parts of warm water, heated to about 80 ° C., stirred with a high speed mixer for about 1 hour to form a slurry, filtered and washed with water to remove salt and solvent, and then at 80 ° C. for 24 hours. Dried to obtain 102 parts of a salt milled pigment (R-3). Table 4 shows the primary particle diameter of the obtained pigment.

[Production Example 3]
A sulfonation flask is charged with 170 parts of tert-amyl alcohol under a nitrogen atmosphere. 11.04 parts of sodium are added and the mixture is heated to 92-102 ° C. The molten sodium is kept at 100-107 ° C. overnight with vigorous stirring.
A solution prepared by dissolving 44.2 parts of 4-chlorobenzonitrile and 37.2 parts of diisopropyl succinate in 50 parts of tert-amyl alcohol at 80 to 98 ° C. was dissolved in the obtained solution. Introduce over 2 hours. After the introduction, the reaction mixture is stirred for a further 3 hours at 80 ° C. and at the same time 4.88 parts of diisopropyl succinate are added dropwise. The reaction mixture is cooled to room temperature and added to a 20 ° C. mixture of 270 parts of methanol, 200 parts of water, and 48.1 parts of concentrated sulfuric acid and stirring is continued at 20 ° C. for 6 hours. This red mixture was filtered, and the residue was washed with methanol and water and then dried at 80 ° C. to obtain 46.7 parts of a red pigment (R-4). Table 4 shows the primary particle diameter of the obtained pigment.

[Production Example 4]
120 parts of halogenated copper phthalocyanine green pigment PG36 (“Lionol Green 6YK” manufactured by Toyo Ink Co., Ltd.), 1600 parts of crushed salt, and 270 parts of diethylene glycol were charged into a 1 gallon kneader (manufactured by Inoue Seisakusho) at 70 ° C. And kneaded for 12 hours. The mixture was poured into 5000 parts of warm water, stirred at a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered and washed repeatedly to remove salt and solvent, and then at 80 ° C. for 24 hours. It dried and obtained 117 parts of salt milling pigment (G-1). Table 4 shows the primary particle diameter of the obtained pigment.

[Production Example 5]
In a molten salt of 200 ° C. of 356 parts of aluminum chloride and 6 parts of sodium chloride, 46 parts of zinc phthalocyanine was dissolved, cooled to 130 ° C., and stirred for 1 hour. The reaction temperature was raised to 180 ° C., and bromine was added dropwise at 10 parts per hour for 10 hours. Thereafter, chlorine was introduced at 0.8 parts per hour for 5 hours. The reaction solution was gradually poured into 3200 parts of water, then filtered and washed with water to obtain 107.8 parts of a crude zinc halide phthalocyanine pigment.
The average number of bromine contained in one molecule of the crude zinc halide phthalocyanine pigment was 14.1 and the average number of chlorine was 1.9. 120 parts of the obtained crude zinc halide phthalocyanine pigment, 1600 parts of crushed salt and 270 parts of diethylene glycol were charged into a stainless steel 1 gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 70 ° C. for 12 hours. The mixture was poured into 5000 parts of warm water, stirred at a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered and washed repeatedly to remove salt and solvent, and then at 80 ° C. for 24 hours. It dried and obtained 117 parts of salt milling process pigments (G-2). Table 4 shows the primary particle diameter of the obtained pigment.

[Production Example 6]
A separable flask was charged with 150 parts of water, and further stirred with 63 parts of 35% hydrochloric acid to prepare a hydrochloric acid solution. While paying attention to foaming, 38.7 parts of benzenesulfonyl hydrazide was charged, and ice was added until the liquid temperature became 0 ° C. or lower. After cooling, 19 parts of sodium nitrite was charged over 30 minutes, stirred for 30 minutes at 0 to 15 ° C., and then sulfamic acid was charged until no coloration was observed on the potassium iodide starch paper.
Furthermore, after adding 25.6 parts of barbituric acid, it heated up to 55 degreeC and stirred as it was for 2 hours. Further, 25.6 parts of barbituric acid was added, the temperature was raised to 80 ° C., and then sodium hydroxide was added until pH became 5. After further stirring for 3 hours at 80 ° C., the temperature was lowered to 70 ° C., followed by filtration and washing with warm water. The obtained press cake was reslurried in 1200 parts of warm water, and then stirred at 80 ° C. for 2 hours. Thereafter, filtration was performed at the same temperature, and washing with 2000 parts of water at 80 ° C. was performed with warm water, and it was confirmed that benzenephonamide was transferred to the filtrate side.
The obtained press cake was dried at 80 ° C. to obtain 61.0 parts of disodium azobarbituric acid. Next, 200 parts of water was charged into a separable flask, and 8.1 parts of the obtained disodium azobarbituric acid powder was added and dispersed while stirring. After uniformly dispersing, the solution was heated to 95 ° C., and 5.7 parts of melamine and 1.0 part of diallylaminomelamine were added.
Further, a green solution obtained by dissolving 6.3 parts of cobalt (II) chloride hexahydrate in 30 parts of water was added dropwise over 30 minutes. After completion of the dropwise addition, complexation was performed at 90 ° C. for 1.5 hours. Thereafter, the pH was adjusted to 5.5, and 2 parts of xylene, 0.4 parts of sodium oleate, and 16 parts of water were previously stirred to add 20.4 parts of the emulsion. did. After cooling to 70 ° C., it was quickly filtered, and washing with warm water at 70 ° C. was repeated until the inorganic salt could be washed. Thereafter, 14 parts of an azo yellow pigment (Y-2) was obtained through drying and pulverization steps. Table 4 shows the primary particle diameter of the obtained pigment.

[Production Example 7]
100 parts of copper phthalocyanine-based blue pigment PB15: 6 (“Rionol Blue ES” manufactured by Toyo Ink Manufacturing Co., Ltd.), 800 parts of crushed salt and 100 parts of diethylene glycol were charged into a 1 gallon kneader (manufactured by Inoue Seisakusho) at 70 ° C. And kneaded for 12 hours. The mixture was poured into 3000 parts of warm water, stirred at a high speed mixer for about 1 hour while being heated to about 70 ° C. to form a slurry, filtered and washed repeatedly to remove salt and solvent, and then at 80 ° C. for 24 hours. It dried and obtained 98 parts of salt milling pigment (B-1). Table 4 shows the primary particle diameter of the obtained pigment.

b) Preparation of acrylic resin solution Put 800 parts of cyclohexanone in a reaction vessel, heat to 100 ° C. while injecting nitrogen gas into the vessel, and drop the mixture of the following monomer and thermal polymerization initiator at the same temperature over 1 hour. Then, a polymerization reaction was performed.
Styrene 60.0 parts Methacrylic acid 60.0 parts Methyl methacrylate 65.0 parts Butyl methacrylate 65.0 parts Azobisisobutyronitrile 10.0 parts After dropwise addition, the mixture is further reacted at 100 ° C for 3 hours, and then azo A solution obtained by dissolving 2.0 parts of bisisobutyronitrile in 50 parts of cyclohexanone was added, and the reaction was further continued at 100 ° C. for 1 hour to synthesize a resin solution. After cooling to room temperature, about 2 g of the resin solution was sampled, heated and dried at 180 ° C. for 20 minutes to measure the nonvolatile content, and cyclohexanone was added to the previously synthesized resin solution so that the nonvolatile content was 20%. An acrylic resin solution was prepared.

c) Preparation of Pigment Dispersion After uniformly mixing the mixture (weight ratio) shown in Table 5 with zirconia beads having a diameter of 1 mm, the mixture was dispersed in a sand mill for 5 hours, and then filtered through a 5 μm filter. Each color pigment dispersion was obtained.

d) Retardation adjuster The following commercially available compounds were used as retardation adjusters.
Melamine compound ・ ・ ・ Nippon Carbide Industries (trade name Nikarak MX-750)
Porphyrin compound: manufactured by Tokyo Chemical Industry (trade name: tetraphenylporphyrin)
Epoxy compound-Japan epoxy resin (trade name Epicoat 828)

e) Preparation of colored composition (hereinafter referred to as resist) Next, a mixture having a composition (weight ratio) shown in Table 6 was uniformly stirred and mixed, and then filtered through a 1 μm filter to obtain each color resist.

f) Preparation of each color coating film Each color resist shown in Table 4 was applied to a glass substrate by spin coating, and then pre-baked at 70 ° C. for 20 minutes in a clean oven. Next, the substrate was cooled to room temperature and then exposed to ultraviolet rays using an ultrahigh pressure mercury lamp. Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Thereafter, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to obtain each color coating film. The film thickness of the dried coating film was 2.0 μm in all cases.

g) Measurement of chromaticity, spectral transmittance, thickness direction retardation value and contrast of each color coating film
[Chromaticity, spectral transmittance]
The chromaticity in the XYZ color system chromaticity diagram was measured using a spectrophotometer ("OSP-200" manufactured by Olympus). Table 5 shows the chromaticity of each color coating film prepared from each color resist shown in Table 4.

[Thickness direction retardation value Rth]
Thickness direction retardation value is in the range of 400 nm to 700 nm from a direction inclined 45 ° from the normal direction of the substrate on which the coating film is formed using a transmission spectroscopic ellipsometer (“M-220” manufactured by JASCO Corporation). Measurements were made at a wavelength of every 5 nm to obtain an ellipso parameter δ. A retardation value Δ (λ) was calculated from Δ = δ / 360 × λ, a three-dimensional refractive index was calculated using this value, and a thickness direction retardation value (Rth) was calculated from the following equation 2. However, measurement was performed at a wavelength of 610 nm for a red colored pixel, 550 nm for a green colored pixel, and 450 nm for a blue colored pixel.
Rth = {(Nx + Ny) / 2−Nz} × d (Formula 1)
In the formula, Nx is a refractive index in the x direction in the plane of the colored pixel layer, Ny is a refractive index in the y direction in the plane of the colored pixel layer, and Nz is a refractive index in the thickness direction of the colored pixel layer. , Nx is a slow axis where Nx ≧ Ny.
d is the thickness (nm) of the colored pixel layer. Table 5 shows the thickness direction retardation value Rth of each color coating film prepared from each color resist shown in Table 4.

[contrast]
A polarizing plate was placed on both sides of the substrate on which the coating film was formed, and the ratio of luminance (Lp) when the polarizing plate was parallel and luminance (Lc) when it was orthogonal, Lp / Lc was calculated as contrast (C).
And the contrast (CS) of only the board | substrate without a colored coating film was measured, and it normalized by C / CS. The luminance was measured using a color luminance meter (“BM-5A” manufactured by Topcon Corporation) under the condition of a 2 ° visual field, and “NPF-SEG1224DU” manufactured by Nitto Denko Corporation was used as the polarizing plate. Table 7 shows the contrast of each color coating film prepared from each color resist shown in Table 4.

h) Production of color filter A color filter was produced by the method shown below by combining the color resists shown in Table 4.
[Example 1]
First, a red resist (RR-1) was applied by spin coating to a glass substrate on which a black matrix had been previously formed, and then prebaked at 70 ° C. for 20 minutes in a clean oven. Next, after cooling the substrate to room temperature, ultraviolet rays were exposed through a photomask using an ultrahigh pressure mercury lamp.
Thereafter, the substrate was spray-developed using a sodium carbonate aqueous solution at 23 ° C., washed with ion-exchanged water, and air-dried. Further, post-baking was performed at 230 ° C. for 30 minutes in a clean oven to form striped red pixels on the substrate.
Next, a green pixel was similarly formed using a green resist (GR-3), and further a blue pixel was formed using a blue resist (BR-1) to obtain a color filter. The formed film thickness of each color pixel was 2.0 μm.

[Example 2]
A color filter was obtained in the same manner as in Example 1 except that the green resist was changed from (GR-3) to (GR-6).

[Example 3]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-2) and the green resist was changed from (GR-3) to (GR-2).

[Example 4]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-3) and the green resist was changed from (GR-3) to (GR-2).

[Example 5]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-3) and the green resist was changed from (GR-3) to (GR-5).

[Example 6]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-4).

[Example 7]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-5) and the green resist was changed from (GR-3) to (GR-2).

[Example 8]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-4) and the green resist was changed from (GR-3) to (GR-6).

[Example 9]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-5) and the green resist was changed from (GR-3) to (GR-7).

[Example 10]
The red resist was changed from (RR-1) to (RR-4), the green resist was changed from (GR-3) to (GR-7), and the blue resist was changed from (BR-1) to (BR-2). In the same manner as in Example 1, a color filter was obtained.

[Comparative Example 1]
A color filter was obtained in the same manner as in Example 1 except that the green resist was changed from (GR-3) to (GR-1).

[Comparative Example 2]
A color filter was obtained in the same manner as in Comparative Example 1 except that the green resist was changed from (GR-3) to (GR-4).

[Comparative Example 3]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-2) and the green resist was changed from (GR-3) to (GR-1).

[Comparative Example 4]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-2) and the green resist was changed from (GR-3) to (GR-4).

[Comparative Example 5]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-3) and the green resist was changed from (GR-3) to (GR-1).

[Comparative Example 6]
A color filter was obtained in the same manner as in Example 1 except that the red resist was changed from (RR-1) to (RR-3) and the green resist was changed from (GR-3) to (GR-4).

i) Production of liquid crystal display device A transparent ITO electrode layer was formed on the obtained color filter, and a polyimide alignment layer was formed thereon. A polarizing plate was formed on the other surface of this glass substrate.
On the other hand, a TFT array and a pixel electrode were formed on one surface of another (second) glass substrate, and a polarizing plate was formed on the other surface. The two glass substrates thus prepared face each other so that the electrode layers face each other, and are aligned using spacer beads while keeping the distance between both substrates constant, and the periphery is left so as to leave an opening for injecting the liquid crystal composition. Sealed with a sealant.
A liquid crystal composition was injected from the opening to seal the opening. The polarizing plate was provided with an optical compensation layer optimized to display a wide viewing angle. The liquid crystal display device thus produced was combined with a backlight unit to obtain a liquid crystal panel.

j) Visibility evaluation during black display of liquid crystal display device
The produced liquid crystal display device is displayed in black, and the amount of light (orthogonal transmitted light; leaked light) leaking from the normal direction (front) of the liquid crystal panel and an orientation (oblique) 45 ° from the normal direction is visually observed. did. The evaluation rank is as follows, and the results are shown in Table 8.

  As shown in Examples 1 to 9, since the green color is formed using a colorant composition containing a retardation adjusting agent, the obtained color filter is used in a liquid crystal display device, so that the visibility in the oblique direction is improved. A good liquid crystal display device can be obtained.

  Furthermore, since the color filters obtained from Examples 5, 8, and 9 achieve high contrast in the front, a liquid crystal display device having good visibility in the front direction can be obtained. In the color filters obtained from Comparative Examples 1 to 7, since the green colorant composition containing the retardation adjusting agent is used and not formed, there is a balance in retardation in the thickness direction of the red pixel, the green pixel, and the blue pixel. Since it is not good, a color shift occurs in an oblique direction, resulting in poor visibility.

It is a schematic sectional drawing which shows the color filter which concerns on one embodiment of this invention. It is a schematic sectional drawing which shows an example of the liquid crystal display device provided with the color filter of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Glass substrate 2 ... Black matrix 3 ... Colored pixel 4 ... Liquid crystal display device 5, 6 ... Transparent substrate 7 ... TFT array 8, 12 ... Transparent electrode 9, 13 ... Alignment layer 10, 14 ... Polarizing plate 11 ... Color filter 15 ... Triwave lamp 16 ... Backlight unit

Claims (6)

  On the transparent substrate, at least one color is a color filter comprising a plurality of colored layers having a colored layer formed by curing and forming a colored composition to which a retardation adjusting agent is added, each colored layer of the color filter being Between the two polarizing plates, a backlight is applied from one polarizing plate side, the light transmitted through the other polarizing plate is measured with a luminance meter, and the luminance (Lp) of the light in the parallel state of the polarizing plate The contrast C (C = Lp / Lc) calculated from the ratio of the light luminance (Lc) in the orthogonal state and the contrast CS (C / CS) measured by sandwiching only a transparent substrate without colored pixels between polarizing plates However, the colored layer having a color layer larger than 0.45 has two or more colors.   The color filter according to claim 1, wherein the retardation adjusting agent comprises a compound that increases retardation.   The retardation adjusting agent is an organic compound selected from one or more selected from an organic compound having a planar structure group having one or more crosslinkable groups, a melamine compound, a porphyrin compound, and a polymerizable liquid crystal compound. The color filter according to claim 2, wherein the color filter is a color filter.   The color filter according to any one of claims 1 to 3, wherein the organic pigment is an organic pigment having an average primary particle in the range of 5 to 40 nm.   The color filter according to claim 1, wherein the colored pixel includes at least green.   A liquid crystal display device using the color filter according to claim 1.