JP2003057434A - Color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color filter which has excellent spectroscopic characteristics and can impart high brightness and high chroma to an LCD at the same time. SOLUTION: The color filter has at least one red color filter segment, at least one blue color filter segment and at least one green color filter segment. A ratio (A570/A595) of absorbency (A570) to light with a wavelength of 570 nm and absorbency (A595) with a wavelength of 595 nm of at least one red color filter segment is 20 or more.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color filter used in a color liquid crystal display device and a solid-state image sensor.

[0002]

2. Description of the Related Art In recent years, liquid crystal displays (hereinafter, LCDs)
"), A color filter is used to meet the request for colorization. For example, a color filter used in a thin film transistor (TFT) type LCD has a filter segment corresponding to light of three primary colors of red (R), green (G) and blue (B) formed on a transparent substrate. A color display is performed by dispersing the lights of the three primary colors of R, G, and B with a color filter. Therefore, the most important characteristic required for the color filter is the spectral characteristic.

In general, a desirable spectral characteristic of a color filter is that a light emission line of a three-wavelength tube which is a backlight light source has a high transmittance for a dominant wavelength of color and a low transmittance for other wavelength regions. The wavelengths of the emission line of a general three-wavelength tube are mainly 580 nm and 610 nm.
(R), 490 nm and 540-545 nm (G) and 460 nm (B). Therefore, in the case of the red color filter segment that constitutes the color filter, it is desirable that the transmittance for light having wavelengths of 610 nm and 580 nm is high and the transmittance for light of other wavelengths is suppressed as low as possible. The same applies to the color filter segment. Further, a color filter for a TFT type LCD is required to have high brightness and high saturation also in terms of energy saving.

On the other hand, in the case of producing a red filter segment, it is common to use two or more kinds of pigments for toning in order to obtain the required color characteristics, and conventionally dianthraquinone has been used as the main pigment. Pigments, perylene pigments, diketopyrrolopyrrole pigments and the like are used. In particular, diketopyrrolopyrrole pigments have high lightness and excellent light resistance and heat resistance, so that they are increasingly used as pigments for color filters. Also, CI Pigment Yellow 139 and CI Pigm are used as yellow pigments for toning.
ent Yellow83 etc. are used.

[0005]

However, as the demand for color filters is increasing day by day, such as increasing the lightness and increasing the color purity, the color characteristics are improved by simply blending the above-mentioned pigments even if they are miniaturized or finely dispersed. There was a limit to.
Therefore, an object of the present invention is to provide a color filter having excellent spectral characteristics and capable of simultaneously imparting high brightness and high saturation to an LCD.

[0006]

Generally, a red filter segment has a transmittance spectrum that rises around 570 nm and transmits light of longer wavelength side and does not transmit light of shorter wavelength side. Desired. And
The steeper this rising slope is, the higher brightness can be achieved. From this, the present inventors have found that the spectral characteristics of the red color filter segment forming the RGB type color filter include the absorbance (A570) at 570 nm, which is the wavelength immediately after the transmission spectrum starts rising, and the wavelength immediately before the transmission spectrum ends. The inventors have found that high brightness can be achieved by increasing the ratio (A570 / A595) to the absorbance (A595) at 595 nm, which is specifically, by setting A570 / A595 to 20 or more, and have reached the present invention. .

That is, the present invention comprises at least one red filter segment, at least one blue filter segment, and at least one green filter segment, wherein the at least one red filter segment absorbs light having a wavelength of 570 nm. (A5
70) and the absorbance (A595) at a wavelength of 595 nm (A570 / A595) of 20 or more. The at least one red filter segment is formed from a colorant carrier composed of a transparent resin, a precursor thereof or a mixture thereof, and a reddish coloring composition containing a diketopyrrolopyrrole pigment dispersed in the colorant carrier. It is preferable.

The above-mentioned diketopyrrolopyrrole pigment is a reddish diketopyrrolopyrrole pigment (A) having a wavelength of 575 nm or more of the intermediate transmittance between the minimum transmittance and the maximum transmittance in the spectral transmittance, and the spectral transmittance. Yellow diketopyrrolopyrrole pigment (B), dye derivative (C), water-soluble inorganic salt (D), and water-soluble inorganic having a wavelength of intermediate transmittance between the minimum transmittance and the maximum transmittance of less than 575 nm A pigment obtained by kneading a mixture containing a water-soluble organic solvent (E) that does not substantially dissolve the salt (D), and then removing the water-soluble inorganic salt (D) and the water-soluble organic solvent (E). preferable.

[0009]

The color filter of the invention comprises at least one red filter segment, at least one blue filter segment and at least one green filter segment, the wavelength of the at least one red filter segment being Absorbance for light of 570 nm (A570) and absorbance for wavelength of 595 nm (A
595) (A570 / A595) is 20 or more, preferably 23 or more, and more preferably 25 or more.
When A570 / A595 is less than 20, the lightness is low and it is not possible to achieve both high lightness and high saturation. In addition,
The larger A570 / A595 is, the more preferable.

The absorbance in the present invention is a value A calculated by the following equation, where I ₀ is the intensity of incident light on a substance and I is the intensity of transmitted light after passing through the substance. Means
Generally, it can be measured by a spectrophotometer. A = log ₁₀ (I ₀ / I)

The red filter segment comprises a colorant carrier made of a transparent resin, its precursor or a mixture thereof,
It can be formed using a red coloring composition containing a red pigment dispersed in the color carrier. As a red pigment,
Examples thereof include diketopyrrolopyrrole pigments, quinacridone pigments, azo pigments, and anthraquinone pigments, but diketopyrrolopyrrole pigments having high brightness are preferable.

The diketopyrrolopyrrole (hereinafter referred to as DPP) type pigment is a red pigment having a structure represented by the following general formula and has excellent light resistance and heat resistance.

[Chemical 1] In the formula, X ₁ and X ₂ each independently represent —H, an optionally substituted saturated or unsaturated alkyl group, a cyano group, an optionally substituted aryl group, or a halogen group.

The DPP pigment has a wavelength of the intermediate transmittance between the minimum transmittance and the maximum transmittance in the spectral transmittance of 575 nm.
There are reddish pigments and yellowish pigments having a wavelength of the intermediate transmittance between the minimum transmittance and the maximum transmittance of less than 575 nm in the spectral transmittance, and there are reddish DPP-based pigments and yellowish DPP-based pigments. A combination is preferable because a red filter segment having a large A570 / A595 and a high brightness can be formed. Further, the reddish DPP having a wavelength of 575 nm or more in the intermediate transmittance between the minimum transmittance and the maximum transmittance in the spectral transmittance.
-Based pigment (A), a yellowish DP whose wavelength of the intermediate transmittance between the minimum transmittance and the maximum transmittance in the spectral transmittance is less than 575 nm
A mixture containing a P-based pigment (B), a dye derivative (C), a water-soluble inorganic salt (D), and a water-soluble organic solvent (E) that does not substantially dissolve the water-soluble inorganic salt (D) is kneaded (hereinafter, DPP obtained by removing the water-soluble inorganic salt (D) and the water-soluble organic solvent (E) after coking.
The system-based pigment is particularly preferable because it has a higher lightness as compared with a system in which a reddish DPP-based pigment and a yellowish DPP-based pigment are separately subjected to a finer treatment and mixed to adjust the color.

Specific examples of the reddish DPP pigment (A) are shown by color index numbers, CI Pigment Red2
54 and 264, and the wavelengths of the intermediate transmittance of the minimum transmittance and the maximum transmittance in the spectral transmittance (hereinafter, referred to as half-value wavelength) are 580 nm and 600 nm, respectively. In the present invention, it is preferable to use CI Pigment Red 254, which has high brightness. When specific examples of yellowish DPP pigments (B) are shown by color index numbers, CI Pigment Red 255 and CI Pigment Orang
e71, half-value wavelengths are 570 nm and 5 respectively.
55 nm. In particular, the reddish DPP pigment (A) is C.
I. Pigment Red 254, and the yellowish DPP pigment (B) is CI Pigment Orange 71 or CI Pigment
Red 255 is preferable because it has a large effect of improving brightness when co-kneading.

The red coloring composition of the present invention may contain a yellow pigment depending on required color characteristics.
CI Pigment Yellow 1, 2, 3,
4, 5, 6, 10, 12, 13, 14, 15, 16, 1
7, 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, 7
4, 77, 81, 83, 93, 94, 95, 97, 9
8, 100, 101, 104, 106, 108, 10
9, 110, 113, 114, 115, 116, 11
7, 118, 119, 120, 123, 126, 12
7, 128, 129, 138, 139, 147, 15
0, 151, 152, 153, 154, 155, 15
6, 161, 162, 164, 166, 167, 16
8, 169, 170, 171, 172, 173, 17
4, 175, 176, 177, 179, 180, 18
1, 182, 185, 187, 188, 193, 19
4, 199 and the like.

The dye derivative (C) is a compound in which a substituent is introduced into the molecule of an organic dye, and DP during co-kneading
It serves to suppress the crystal growth of the P-based pigment.
The structure of the organic pigment that is the base of the pigment derivative is DP
P type, quinacridone type, anthraquinone type, perylene type, perinone type, isoindoline type, quinophthalone type,
There are metal complex systems and the like. The organic dye may be a pale yellow aromatic polycyclic compound such as a naphthalene-based or anthraquinone-based compound which is not generally called a dye. Of these, a dye derivative having a DPP-based or quinacridone-based dye as a base skeleton is particularly preferable because it has a high effect of suppressing crystal growth of the DPP-based pigment. Further, as the dye derivative, those having a hue of yellow, orange, and red, which have little influence on the hue of the DPP pigment, are preferably used.

The substituent introduced into the organic dye includes a hydroxyl group, a carboxyl group, a sulfonic acid group, a carbamoyl group,
Examples thereof include sulfonamide groups and basic substituents represented by the following general formula.

[Chemical 2] Y: a direct _{bond, -CH 2 NHCOCH 2 -, -} SO 2 NH
-, - CONHOCH ₂ NH-, or - (CH ₂₎ qN
Represents H-. R ₁ and R ₂ : each independently represent a saturated or unsaturated alkyl group which may be substituted, or a heterocyclic ring which may be substituted by R ₁ , R ₂ and which contains a nitrogen, oxygen or sulfur atom.

[0018]

[Chemical 3] Z: a direct _{bond, -SO 2 -, - CO -} , - CH 2 NHCO
_{CH 2 -, - (CH 2} ) q -, - SO 2 NH -, - CON
_{H -, - CH 2 NHCOCH 2} NH-, or - (C
Representing the H ₂₎ qNH-. However, q represents the integer of 1-10. R ₃ , R ₄ , R ₅ , and R ₆ : each independently represent a hydrogen atom, an optionally substituted saturated or unsaturated alkyl group, or an aryl group. R ₇ : represents a saturated or unsaturated alkyl group or aryl group which may be substituted.

Table 1 shows specific examples of the dye derivative.

[Table 1]

DPP derivative (C) used when kneading a mixture of DPP pigment (A), (B) dye derivative (C), water-soluble inorganic salt (D), and water-soluble organic solvent (E)
Is not particularly limited, but the DPP pigment (A),
0.5 to 20% by weight, particularly 2 to 15% by weight, based on the total amount of (B), is preferable. The dye derivative (C)
Since it also has an effect as a dispersant, it is preferable to select one having good dispersibility in a colorant carrier. However, a pigment derivative having a high crystal growth preventing effect and another pigment derivative or a dispersant other than the pigment derivative is preferable. And may be combined. As the dispersant other than the dye derivative, a condensate of ricinoleic acid or 12-hydroxystearic acid, a basic polymer compound, a copolymer containing an acid group, a fatty acid ester, an aliphatic polyamine / polyester graft polymer, polyethylene / A so-called resin type dispersant such as a polypropylene addition polymer can be used. These dispersants are used during the co-kneading treatment or during the dispersion of the co-kneading-treated pigment in the colorant carrier.

Specific examples of the resin type dispersant include polycarboxylic acid esters such as polyacrylates, unsaturated polyamides, polycarboxylic acids, polycarboxylic acid (partial) amine salts, polycarboxylic acid ammonium salts, and polycarboxylic acid alkylamines. Salt, polysiloxane, long-chain polyaminoamide phosphate, hydroxyl group-containing polycarboxylic acid ester,
These modified products, amides formed by the reaction of poly (lower alkyleneimine) with polyester having a free carboxyl group, and salts thereof are used. Also,
Water-soluble resin or water-soluble polymer such as (meth) acrylic acid-styrene copolymer, (meth) acrylic acid- (meth) acrylic acid ester copolymer, styrene-maleic acid copolymer, polyvinyl alcohol, polyvinylpyrrolidone Compounds, polyesters, modified polyacrylates, ethylene oxide / propylene oxide adducts, phosphoric acid esters and the like are used. These may be used alone or in admixture of two or more.

The water-soluble inorganic salt (D) acts as a crushing aid, and the DPP-based pigment is crushed by utilizing the high hardness of the inorganic salt during co-kneading, and the primary particles of the DPP-based pigment are finely divided. Be converted. The inorganic salt (D) is not particularly limited as long as it is soluble in water, and sodium chloride, barium chloride, potassium chloride, sodium sulfate or the like can be used, but sodium chloride (salt) is used from the viewpoint of price. Is preferred. The amount of the inorganic salt (D) used during the co-kneading is DP in terms of both treatment efficiency and production efficiency.
It is preferably 1 to 20 times by weight, particularly 3 to 10 times by weight, the total amount of the P-based pigments (A) and (B). This is because the higher the amount ratio of the inorganic salt to the DPP-based pigment is, the higher the micronization efficiency is, but the processing amount of the pigment per one time is reduced.

The water-soluble organic solvent (E) functions to wet the DPP pigments (A), (B), the dye derivative (C) and the water-soluble inorganic salt (D), and dissolves in water ( It is not particularly limited as long as it is mixed (mixed) and does not substantially dissolve the inorganic salt (D) used. However, since the temperature rises during co-kneading and the solvent easily evaporates,
From the viewpoint of safety, a high boiling point solvent having a boiling point of 120 ° C. or higher is preferable. Examples of the water-soluble organic solvent (E) include 2-methoxyethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, Triethylene glycol, triethylene glycol monomethyl ether, liquid polyethylene glycol, 1-methoxy-2-propanol, 1-
Ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, liquid polypropylene glycol and the like are used.

[0024] During co-kneading, the finely divided DP
A resin may be used in combination so as to prevent strong aggregation during drying of the P-based pigment and facilitate dispersion in the colorant carrier. A soft powder pigment can be obtained by using a resin together during the co-kneading. As the resin used for the co-kneading, those which are solid at room temperature, water-insoluble, and at least partially soluble in the above-mentioned organic solvent are preferable, and natural resin, modified natural resin, synthetic resin, synthetic modified with natural resin Resin or the like is used. A rosin is typical as the natural resin, and a rosin derivative, a fibrin derivative, a rubber derivative, a protein derivative and an oligomer thereof are used as the modified natural resin. Examples of the synthetic resin include epoxy resin, acrylic resin, maleic acid resin, butyral resin, polyester resin, melamine resin, phenol resin, polyurethane resin, and polyamide resin. Synthetic resins modified with natural resins include rosin-modified maleic acid resin, rosin-modified phenolic resin,
Examples include rosin-modified fumaric acid resin. The amount of the resin used is preferably in the range of 5 to 100% by weight based on the total amount of the DPP pigments (A) and (B).

At the time of co-kneading, in addition to the above resin,
An additive such as a pigment dispersion aid, a plasticizer, or an inorganic pigment such as calcium carbonate, barium sulfate, or silica, which is generally used as an extender pigment, may be used in combination. Further, in order to adjust the hue, the treatment may be carried out by mixing with other pigments.

By dispersing the above pigment in a colorant carrier composed of a transparent resin, a precursor thereof or a mixture thereof, a red coloring composition used for forming a red filter segment can be obtained. To disperse the pigment in the color carrier,
Various dispersing means such as a three-roll mill, a two-roll mill, a sand mill and a kneader can be used. Further, in order to improve the dispersion of these, various surfactants, dispersion aids such as dye derivatives, etc. can be added as appropriate. The dispersion aid is excellent in dispersing the pigment, and has a large effect of preventing re-aggregation of the pigment after dispersion. Therefore, when using a coloring composition obtained by dispersing the pigment in a colorant carrier using the dispersion aid. Gives a color filter with excellent transparency.

The transparent resin is 400 to 700 in the visible light range.
The resin has a transmittance of preferably 80% or more, more preferably 95% or more in the entire wavelength region of nm. The transparent resin includes a thermoplastic resin, a thermosetting resin, and a photosensitive resin, and the precursor thereof includes a monomer or an oligomer that is cured by irradiation to generate a transparent resin, and these are used alone or Two or more kinds can be mixed and used. In addition, a photoinitiator or the like is added to the red colored composition when the composition is cured by irradiation with ultraviolet rays.

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. , Phenol resin, polyester resin, acrylic resin, alkyd resin, styrene resin, polyamide resin, rubber resin, cyclized rubber, celluloses, polybutadiene, polyimide resin and the like. Examples of thermosetting resins include epoxy resins, benzoguanamine resins, melamine resins, and urea resins.

As the photosensitive resin, a linear polymer having a reactive substituent such as a hydroxyl group, a carboxyl group and an amino group has a reactive substituent such as an isocyanate group, an aldehyde group and an epoxy group (meth). A resin obtained by reacting an acrylic compound or cinnamic acid to introduce a photocrosslinking group such as a (meth) acryloyl group or a styryl group into the linear polymer is used. In addition, styrene-maleic anhydride copolymer and α
A linear polymer containing an acid anhydride such as an olefin-maleic anhydride copolymer half-esterified with a (meth) acrylic compound having a hydroxyl group such as hydroxyalkyl (meth) acrylate may also be used.

As the monomers and oligomers, 2-
Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, polyethylene glycol di (meth)
Acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tricyclodecanyl (meth) acrylate,
Various acrylic acid esters and methacrylic acid esters such as melamine (meth) acrylate and epoxy (meth) acrylate, (meth) acrylic acid, styrene, vinyl acetate, (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, acrylonitrile, etc. Can be mentioned.

As the photoinitiator, 4-phenoxydichloroacetophenone, 4-t-butyl-dichloroacetophenone, diethoxyacetophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1 -Hydroxycyclohexyl phenyl ketone, 2-benzyl-2-dimethylamino-1- (4-
Acetophenone photoinitiators such as morpholinophenyl) -butan-1-one, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin photoinitiators such as benzyl dimethyl ketal, benzophenone, benzoylbenzoic acid, benzoyl Benzophenone photoinitiators such as methyl benzoate, 4-phenylbenzophenone, hydroxybenzophenone, acrylated benzophenone, 4-benzoyl-4′-methyldiphenylsulfide, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, isopropyl Thioxanthone based photoinitiators such as thioxanthone and 2,4-diisopropylthioxanthone, 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-pipenyl-4,6-bis (trichloromethyl) -s-triazine, 2,4-bis (trichloromethyl) -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
A triazine-based photoinitiator such as -triazine and 2,4-trichloromethyl (4'-methoxystyryl) -6-triazine, a carbazole-based photoinitiator, and an imidazole-based photoinitiator are used.

The above photoinitiators may be used alone or in admixture of two or more, and as the sensitizer, α-acyloxime ester, acylphosphine oxide, methylphenylglyoxylate, benzyl, 9,10-phenanthene is used. Lenquinone, camphorquinone, ethylanthraquinone,
4,4'-diethylisophthalophenone, 3,3 ',
4,4'-Tetra (t-butylperoxycarbonyl)
Compounds such as benzophenone and 4,4′-diethylaminobenzophenone can also be used in combination.

In the red coloring composition, a DPP pigment is sufficiently dispersed and coated on a transparent substrate such as a glass substrate so that the dry film thickness is 0.2 to 5 μm to form a red filter segment. A solvent may be included to facilitate the process. 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 acetate, toluene, methyl ethyl ketone, ethyl acetate, methanol, ethanol, isopropyl alcohol, butanol, isobutyl ketone, petroleum solvent and the like can be used alone or in combination. .

The red coloring composition can be prepared in the form of a gravure offset printing ink, a waterless offset printing ink, a silk screen printing ink, a solvent developing type or an alkali developing type colored resist material. The red colored resist material is a composition in which a pigment is dispersed in a composition containing a thermosetting resin, a thermoplastic resin or a photosensitive resin, a monomer, and a photoinitiator.

When the red filter segment is formed by the photolithographic method, the pigment is preferably contained in the red coloring composition in a proportion of 1.5 to 7% by weight, and when formed by the printing method. Is preferably contained in the red coloring composition in a proportion of 1.5 to 40% by weight. The red-colored composition has a coarse particle size of 5 μm or more, which is obtained by means of centrifugation, a sintering filter, a membrane filter, or the like.
Coarse particles of preferably 1 μm or more, more preferably,
It is preferable to remove coarse particles of 0.5 μm or more and mixed dust.

As mentioned above, the color filter of the present invention comprises at least one red filter segment, at least one blue filter segment and at least one green filter segment, wherein the red filter segment is It is formed using the above red coloring composition. The green filter segment and the blue filter segment can be formed using a conventional green coloring composition and a conventional blue coloring composition, respectively. The green coloring composition may be, for example, CI Pig instead of the red pigment.
ment Green 7, 10, 36, 37 and other green pigments. The yellow pigment illustrated above can be used together with the green coloring composition. Further, the blue coloring composition, instead of the red pigment, for example CI Pigment
Blue 15, 15: 1, 15: 2, 15: 3, 15:
It is a composition obtained by using blue pigments such as 4, 15: 6, 16, and 60. CI Pigment V for blue coloring composition
Purple pigments such as iolet 1, 19, 23, 27, 32, 42 can be used in combination.

The color filter of the present invention can be manufactured by forming a filter segment of each color on a transparent substrate by a printing method or a photolithography method using a coloring composition of each color. As a transparent substrate,
A glass plate or a resin plate such as polycarbonate, polymethylmethacrylate, or polyethylene terephthalate is used.

Since the formation of each color filter segment by the printing method can be patterned by simply printing and drying the coloring composition prepared as the above-mentioned various printing inks, the color filter can be mass-produced at a low cost. It has excellent properties. Further, the development of printing technology enables printing of fine patterns having high dimensional accuracy and smoothness. When producing a color filter by printing, it is important to control the fluidity of the ink on the printing machine, and the ink viscosity can be adjusted by a dispersant or an extender pigment.

When each color filter segment is formed by the photolithographic method, the coloring composition prepared as the above-mentioned solvent-developing or alkali-developing colored resist material is spin-coated, slit-coated or roll-coated on a transparent substrate. Apply according to the application method. Then, if necessary, the dried film is exposed to ultraviolet light through a photomask, the unexposed portion is removed with a solvent or an alkaline developer to form a pattern, and the same operation is repeated for other colors to obtain a color filter. Can be manufactured.
According to the photolithography method, it is possible to manufacture a color filter with higher accuracy than the printing method.

As the alkaline developer, an aqueous solution of sodium carbonate, sodium hydroxide or the like is used, and an organic alkali such as dimethylbenzylamine or triethanolamine can also be used. Further, an antifoaming agent or a surfactant can be added to the developing solution. In order to increase the UV exposure sensitivity, after coating and drying the above colored resist material, a water-soluble or alkaline water-soluble resin such as polyvinyl alcohol or water-soluble acrylic resin is applied and dried to form a film that prevents polymerization inhibition by oxygen. After that, ultraviolet exposure can be performed.

As a method of producing a color filter using a pigment, there are an electrodeposition method, a transfer method and the like in addition to the above, and the coloring composition of the present invention can be used in any method. The electrodeposition method is a method of manufacturing a color filter by utilizing a transparent conductive film formed on a transparent substrate to form a colorant on the transparent conductive film by electrophoretic deposition of colloidal particles. The transfer method is a method in which a color filter layer is previously formed on the surface of a peelable transfer base sheet and the color filter layer is transferred to a desired transparent substrate.

Hereinafter, the present invention will be described based on examples, but the present invention is not limited thereto. In the examples and comparative examples, “part” means “part by weight”. The dye derivatives used in the examples are shown in Table 1.

(Preparation of Acrylic Resin Solution) 450 parts of cyclohexanone were placed in a reaction vessel, heated to 80 ° C. while injecting nitrogen gas into the vessel, and at the same temperature, a mixture of the following monomers and a thermal polymerization initiator was added for 1 hour. Was added dropwise to carry out a polymerization reaction. Methacrylic acid 20.0 parts Methyl methacrylate 10.0 parts Butyl methacrylate 55.0 parts Hydroxyethyl methacrylate 15.0 parts Azobisisobutyronitrile 4.0 parts After dropping, and further reacting at 80 ° C. for 3 hours, azobis A solution prepared by dissolving 1.0 part of isobutyronitrile in 50 parts of cyclohexanone was added, and the reaction was continued at 80 ° C. for 1 hour to obtain a solution of an acrylic resin having a weight average molecular weight of about 40,000. 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 resin solution synthesized above so that the nonvolatile content became 20% by weight. To prepare an acrylic resin solution.

[Example 1] DPP pigment ("Irgazin DPP RED B manufactured by Ciba Specialty Chemicals")
O ", CI Pigment Red 254) 106.4 parts, DPP
Pigments (Ciba Specialty Chemicals "Chromophtal DPP Orange TR", CI Pigment Orang
e71) 45.6 parts, DPP dye derivative (e) 8 parts,
1600 parts of sodium chloride and 190 parts of diethylene glycol were charged into a stainless steel 1-gallon kneader (manufactured by Inoue Seisakusho) and kneaded at 60 ° C. for 10 hours. Next, this mixture was poured into 3 liters of warm water and stirred at a high speed mixer for about 1 hour while heating to about 80 ° C. to form a slurry, which was repeatedly filtered and washed with water to remove sodium chloride and the solvent. Dry at ℃ for 1 day, 15
6.8 parts of pigment for color filters was obtained.

A mixture having the following composition containing the obtained pigment was uniformly mixed by stirring, dispersed with a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered with a filter of 5 μm to prepare a DPP pigment dispersion. did. Pigment 9.5 parts DPP-based dye derivative (e) 0.5 part Acrylic resin solution 50.0 parts Propylene glycol monomethyl ether acetate 40.0 parts Then, after stirring and mixing the mixture having the following composition so as to be uniform, 1 μm The alkali developing red resist material was manufactured by filtering with a filter of No. 3. DPP-based pigment dispersion 60.0 parts Acrylic resin solution 11.0 parts Trimethylolpropane triacrylate 4.2 parts (Shin-Nakamura Chemical's "NK ester ATMPT") Photoinitiator (Ciba Geigy's "Irgacure 907") 1.2 parts Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.4 parts Propylene glycol monomethyl ether acetate 23.2 parts

The obtained resist material was treated with 100 mm × 10
On a glass substrate of 0 mm and 1.1 mm thickness, using a spin coater, 500 rpm, 1000 rpm, 1500 r
The coating was performed at a rotation speed of 2,000 rpm and pm to obtain four types of coated substrates having different film thicknesses. Next, after drying at 70 ° C. for 20 minutes,
Ultraviolet light exposure was performed using an ultrahigh pressure mercury lamp with an integrated light amount of 150 mJ. After the exposure, it was heated at 230 ° C. for 1 hour and allowed to cool to form a red coating film on the glass substrate.

Example 2 A pigment for a color filter was prepared in the same manner as in Example 1 except that the DPP pigment "Chromophtal DPP Orange TR" was replaced with a DPP pigment ("Irgazin DPP Scarlet EK" manufactured by Ciba Specialty Chemicals). Using the obtained pigment, an alkali development type red resist material was prepared in the same manner as in Example 1 to form a red coating film on a glass substrate.

[Example 3] Two DPP pigments were used as one DPP pigment "Irgazin DPP RED BO" 15
Micronization was performed in the same manner as in Example 1 except that 2 parts were used.
CI Pigment Red 254 pigment (hereinafter referred to as miniaturized PR254
It is called a pigment. ) Got. In addition, two types of DPP pigment
DPP pigment "Chromophtal DPP Orange T"
R ”152 parts, except that the CI Pigment Orange 71 pigment was miniaturized in the same manner as in Example 1 (hereinafter referred to as the miniaturized P
It is called O71 pigment. ) Got. A mixture having the following composition containing the obtained pigment was uniformly stirred and mixed, and dispersed with a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then 5 μ
m through a filter to prepare a DPP pigment dispersion.
Then, using this, an alkaline development type red resist material was prepared in the same manner as in Example 1, and a red coating film was formed on the glass substrate. Micronized PR254 pigment 6.65 parts Micronized PO71 pigment 2.85 parts DPP dye derivative (e) 0.5 parts Acrylic resin solution 50.0 parts Propylene glycol monomethyl ether acetate 40.0 parts

[Example 4] Two kinds of DPP pigments were combined with one kind of anthraquinone pigment ("Chromophtal red A2B" manufactured by Ciba Specialty Chemicals, CI Pigment R).
ed 177) A CI Pigment Red 177 pigment (hereinafter referred to as a finely-divided PR177 pigment) which has been micronized in the same manner as in Example 1 is obtained except that 152 parts of ed 177) is used. A mixture having the following composition containing the obtained pigment was uniformly stirred and mixed, and dispersed with a sand mill for 5 hours using glass beads having a diameter of 1 mm.
A pigment dispersion was prepared by filtering with a 5 μm filter. Then, using this, an alkaline development type red resist material was prepared in the same manner as in Example 1, and a red coating film was formed on the glass substrate. Micronized PR254 pigment 9.03 parts Micronized PR177 pigment 0.47 part DPP-based pigment derivative (e) 0.25 part Quinacridone-based pigment derivative (f) 0.25 part Acrylic resin solution 50.0 parts Propylene glycol monomethyl ether acetate 40.0 copies

[Comparative Example 1] Two DPP-based pigments were replaced by one isoindoline-based yellow pigment (BASF Corporation "Pariotor Yellow D1819", CI Pigment Yellow 139).
CI Pigment Yellow 139 pigment finely pulverized in the same manner as in Example 1 except that 152 parts was used (hereinafter, finely pulverized P
It is called Y139 pigment. ) Got. A mixture having the following composition was uniformly stirred and mixed, dispersed with a sand mill for 5 hours using glass beads having a diameter of 1 mm, and then filtered with a 5 μm filter to prepare a pigment dispersion. Then, using this, an alkaline development type red resist material was prepared in the same manner as in Example 1, and a red coating film was formed on the glass substrate. Micronized PR254 pigment 7.60 parts Micronized PY139 pigment 1.90 parts DPP dye derivative (e) 0.35 part Quinacridone dye derivative (f) 0.15 part Acrylic resin solution 50.0 parts Propylene glycol monomethyl ether acetate 40.0 copies

Microspectrophotometer (Olympus Optical Co.
SP-SP100 ") of the obtained red coating film
The chromaticity (Y, x, y) at the light source was measured. 4 sets of chromaticity
The chromaticity at x = 0.600 was calculated from the spectroscopic measurement results. In addition, from the result of the spectroscopic measurement, the absorbance ratio (A570 / A
595) was calculated. The results are shown in Table 2.

[0052]

[Table 2] The red coating films formed in the examples and having a large absorbance ratio of 570 nm and 595 nm of 20 or more were both lighter (Y value) than the red coating films formed in the comparative example and having an absorbance ratio of less than 20. Is high.

Next, in order to produce a color filter having a red filter segment, a blue filter segment and a green filter segment, blue and green resist materials were produced by the following method.

(Blue resist material) After agitating and mixing a mixture having the following composition, glass beads having a diameter of 1 mm were used to disperse the mixture in a sand mill for 5 hours and then filtered with a 5 μm filter to prepare a copper phthalocyanine dispersion. did. ε-type copper phthalocyanine pigment 10.0 parts (BASF "Heliogen Blue L-6700F", CI Pigment Blue15: 6) Dispersant (Zeneca "Solspers 20000") 2.0 parts Acrylic resin solution 40.0 parts Cyclohexanone Then, 48.0 parts of the mixture having the following composition was stirred and mixed so as to be uniform, and then filtered through a 1 μm filter to obtain an alkali developing blue resist material. Copper phthalocyanine dispersion 60.0 parts Acrylic resin solution 11.0 parts Trimethylolpropane triacrylate 4.2 parts (Shin Nakamura Chemical Co., Ltd. “NK ester ATMPT”) Photoinitiator (Ciba Geigy “Irgacure 907”) 1 .2 parts Sensitizer ("EAB-F" manufactured by Hodogaya Chemical Co., Ltd.) 0.4 parts Cyclohexanone 23.2 parts

(Green resist material) 10.0 parts of ε-type copper phthalocyanine pigment was replaced with copper phthalocyanine green pigment (“Rionol Green 6YK” manufactured by Toyo Ink Mfg. Co., CI Pigmen
t Green 36) 7.6 parts and an isoindoline yellow pigment ("Pariotor Yellow D1819" manufactured by BASF Corporation, C.I.
I. Pigment Yellow 139) An alkaline developing green resist material was obtained in the same manner as the blue resist material, except that the amount was changed to 1.4 parts.

The red resist material obtained in Example 1 was applied onto a glass substrate by spin coating so that the film thickness of the chromaticity shown in Table 2 was obtained. After drying, stripe-shaped pattern exposure was performed using an exposure machine, and development was performed for 90 seconds with an alkaline developer to form stripe-shaped red filter segments. As the alkaline developing solution, sodium carbonate 1.5% by weight, sodium hydrogencarbonate 0.5% by weight, an anionic surfactant (“Perirex NBL” manufactured by Kao Corporation).
A mixture consisting of 0% by weight and 90% by weight of water was used.

Next, similarly to the red resist material, a green resist material was applied so as to have a chromaticity thickness shown in Table 3. After drying, pattern exposure in a stripe shape adjacent to the red filter segment was performed using an exposure machine to form a stripe-shaped green filter segment. Further, similarly to the red resist material, a blue resist material was applied so as to have the following chromaticity thickness shown in Table 3 to form a stripe-shaped blue filter segment adjacent to the red and green filter segments. . The shape of the filter segment of each color was good, and the resolution was also good. Finally, the obtained color filter is heated in an oven at 230 ° C. for 30 minutes.
After heating for a minute, the remaining polymerizable functional groups were completely reacted to obtain a color filter having a stripe-shaped filter segment of three colors of red, green and blue on a transparent substrate. The red resist material obtained in Example 1 was replaced with the red resist material obtained in Examples 2 to 4 in the same manner as above, and three color stripe-shaped filter segments of red, green and blue were formed on the transparent substrate. To prepare a color filter.

[0058]

[Table 3]

[0059]

As described above, according to the present invention, it is possible to obtain a color filter having a red filter segment which is excellent in both high transmittance and high color purity.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2H025 AA00 AB13 AD01 BC13 BC42                       CA00 CB13 CB14 CC11                 2H048 BA02 BA45 BA48 BA57 BA58                       BA62 BB03 BB14 BB15 BB42                       BB46 CA04 CA14 CA19 CA23                       CA29                 2H091 FA02Y FB02 FB03 FB04                       FB12 FC10 FC12 FC22 FC23                       FD04 GA01 LA15 LA16

Claims (5)

[Claims] 1. At least one red filter segment, at least one blue filter segment, and at least one green filter segment, the at least one red filter segment having a wavelength of 5;
Absorbance for light of 70 nm (A570) and wavelength of 59
Ratio (A570 / A59) with absorbance at 5 nm (A595)
5) The color filter is characterized by being 20 or more. 2. A red coloring composition in which at least one red filter segment comprises a color carrier comprising a transparent resin, a precursor thereof or a mixture thereof, and a diketopyrrolopyrrole pigment dispersed in the color carrier. The color filter according to claim 1, wherein the color filter is formed of: 3. A diketopyrrolopyrrole pigment (A), which is a reddish diketopyrrolopyrrole pigment (A) having a wavelength of 575 nm or more between the minimum transmittance and the maximum transmittance in the spectral transmittance, and the spectral transmittance. A yellowish diketopyrrolopyrrole pigment (B), a dye derivative (C), a water-soluble inorganic salt (D), and a water-soluble inorganic salt having a wavelength of the intermediate transmittance between the lowest transmittance and the highest transmittance of less than 575 nm. A pigment obtained by kneading a mixture containing a water-soluble organic solvent (E) that does not substantially dissolve (D), and then removing the water-soluble inorganic salt (D) and the water-soluble organic solvent (E). The color filter according to claim 2. 4. A reddish diketopyrrolopyrrole pigment (A)
Is CI Pigment Red 254, and the yellowish diketopyrrolopyrrole pigment (B) is CI Pigment Orange 71 or
The color filter according to claim 3, which is CI Pigment Red 255. 5. The color filter according to claim 3, wherein the dye derivative (C) is a quinacridone derivative and / or a diketopyrrolopyrrole derivative.