JPH0971744A - Ink for color filter, color filter, and liquid crystal panel with the filter incorporated therein - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an ink which is suitable for being applied to a substrate by an ink jet method to arrange colored pixels to produce a color filter by incorporating specific water-sol. red and yellow dyes into the ink. SOLUTION: This ink contains a water-sol. red dye (e.g. C.I. Direct Red 218) which has such spectral characteritics that a water soln. prepd. so as to have a transmittance at 545nm of 3% has a transmittance at 610nm of 70% or higher and a transmittance at 435nm of 50% or lower, a water-sol yellow dye (e.g. C.I. Acid Yellow 17) which has such spectral characteristics that a water soln. prepd. so as to have a transmittance at 435nm of 20% has a transmittance at 610nm of 95% or higher in a wt. ratio of the former to the latter dye of (20:1)-(1:1), and 10-60wt.% solvent having a b.p. of 150-250 deg.C (e.g. N- methylformamide). A color filter is produced by coating a substrate with the ink by an ink jet method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a color filter for a color liquid crystal display used in a color television, a personal computer or the like. More specifically, the present invention relates to a color filter ink using an inkjet recording technique, a method for manufacturing a color filter,
In particular, the present invention relates to a method of manufacturing a color filter including blue (B) color pixels having an improved color tone (spectral characteristic), a color filter manufactured by the manufacturing method, and a liquid crystal panel incorporating the same filter.

[0002]

2. Description of the Related Art A color filter is an important component of a color liquid crystal display. This filter has a large number of pixels of red (R), green (R), and blue (B) arranged repeatedly on a transparent substrate. It has a structure.

With the recent development of personal computers, especially portable personal computers, the demand for liquid crystal displays, especially color liquid crystal displays, has been increasing. However, for further popularization, it is necessary to satisfy the conflicting requirements that the manufacturing cost of the display main body must be reduced while providing a display with higher definition and higher image quality. In particular, the above-mentioned demand for a color filter, which has a high specific gravity in terms of cost, is rapidly increasing.

Conventionally, various filter manufacturing methods have been attempted in order to meet the above requirements while satisfying the required characteristics of color filters, but the present situation is that a method that satisfies all required performances has not yet been established. Is.

A typical method of manufacturing a color filter will be described below.

The first method, which is most often used, is the dyeing method. The dyeing method uses a water-soluble polymer material that is easy to dye and is sensitized by adding a photosensitizer.
This is patterned into a desired shape on a transparent support by a photolithography process, and the obtained pattern is immersed in a dyeing bath to obtain a colored pattern. This is repeated three times to form R, G, B color filters.

The second method, which is most often used next, is the pigment dispersion method, which has recently been replaced by the dyeing method. In this method, first, a photosensitive resin layer in which a resin is dispersed is formed on a substrate, and this is patterned to obtain a monochrome pattern. By repeating this process three times,
An R, G, B three color filter is formed.

A third method is an electrodeposition method. In this method, first, a transparent electrode is patterned on a substrate. Next, the first color is electrodeposited by immersing it in an electrodeposition coating liquid containing a pigment, a resin, an electrolytic solution and the like. This process is repeated 3 times and R, G, B
The color filter layer is formed, and finally, the color filter is baked to form the color filter.

In each method, a protective layer is generally formed on the colored layer.

Common to these methods is that R,
The same process is repeated three times to form G and B, which inevitably increases the manufacturing cost. There is also a problem that the yield decreases as the number of processes increases.

Moreover, in the third method by electrodeposition, since the pattern that can be formed is limited, the current technique is
Not applicable to FT color.

As mentioned above, there are already some methods for producing a color filter, but when importance is attached to the chromaticity of a display, a dyeing method using a dye as a coloring material is generally considered to be advantageous. There is.

However, as described above, in the dyeing method, the method of immersing the substrate in the dyeing solution when forming the pixel is adopted, and therefore the dye which is difficult to be dyed on the receiving layer to be used may have a color tone (spectral characteristic). However, there is a drawback that it cannot be used even if it is good. In order to increase the types of dyes that can be used, attempts are generally made to improve the dyeing property of the dye by introducing a cation group such as quaternary ammonium into the receptor layer when the dye is an anionic type. However, there are problems such as a change in color tone of the dye (spectrum shift) and a decrease in heat resistance.

Furthermore, when a dyeing solution composed of a plurality of dyes is used for color matching, it is difficult to control the desired color tone because the dyeing properties of the dyes and the receiving layer are not the same. There are also problems. Therefore, in reality, it is difficult to control the color tone delicately, and the types of dyes and receiving layer materials that can be used are greatly limited.

[0015]

In order to improve these drawbacks, a method of manufacturing a color filter using an ink jet method has been proposed (Japanese Patent Laid-Open No. 59-7520).
5, JP-A-63-235901, JP-A-1-21730
2, JP-A-4-123005, etc.).

These are different from the above-mentioned method in that R, G, B
A colored liquid (hereinafter referred to as ink) containing each of the dyes is sprayed from a nozzle onto a filter substrate, and the ink is dried on the filter substrate to form pixels.

According to this method, since the formation of the colored portion does not go through the dyeing process between the dye and the receiving layer as in the above-mentioned dyeing method, a method for improving the dyeing property by introducing a cation group on the receiving layer side is used. You don't have to. Therefore, it is possible to avoid problems such as a change in color tone of the dye itself (spectrum shift) before and after dyeing and a decrease in heat resistance. Furthermore, in the case of using an ink containing a plurality of dyes for toning. However, the color tone does not differ greatly from what was expected.

Further, since the R, G, and B colored layers can be formed at one time, and the amount of ink used is not wasted, the productivity can be greatly improved and the cost can be reduced. Can be expected.

However, in the conventional ink jet method for producing a color filter, the dyes used are not always suitable for the ink jet method, and the matching of the receiving layer material with the dye and the drawing conditions by the ink jet method (receptive layer type). , And the amount of dye injected there), etc., are technically unclear. For this reason, the following new technical problems 1 to 4 have occurred, but none satisfy all of the following required characteristics, and therefore, an urgent solution to the problem has been desired to be established. 1) Adhesiveness between the colored portion and the color filter substrate is good. 2) Color purity of the colored portion is high (for example, in the case of B pixel, light in the G and R wavelength bands is sufficiently shielded. ) 3) No bleeding in the colored part 4) Good heat resistance in the colored part The present invention has been made to solve the above problems, and an object thereof is to satisfy all the required properties described above. An object of the present invention is to provide a color filter ink, a color filter manufactured by using the ink, a manufacturing method thereof, and a liquid crystal panel including the color filter.

[0020]

In order to achieve the above object, the present invention provides a color used in a color filter in which a plurality of colored pixels are arranged by applying ink onto a substrate by an inkjet method. In the filter ink, a water-soluble red dye (a), and a water-soluble yellow dye (b), (a) red color, which contains 10 to 60% by weight of a solvent having a boiling point of 150 to 250 ° C. and has the following characteristics: Dye: A water solution prepared to have a transmittance of 3.0% at 545 nm has a transmittance of 70.0 at 610 nm.
% Or more, and the transmittance at 435 nm is 50.0%
Water-soluble red dye having the following spectral characteristics, (b) Yellow dye: 95% transmittance at 610 nm in an aqueous solution prepared so that the transmittance at 435 nm is 20.0%.
A color filter ink comprising a water-soluble yellow dye having the above-mentioned spectral characteristics in a weight ratio of 20: 1 to 1: 1. And the dye (b) in a weight ratio of 10: 1 to
Including both in the range of 1: 1 and the total dye concentration in the ink is 1 to 15% by weight.

The present invention also provides a color filter in which a plurality of colored pixels are arranged on an optically transparent ink receiving layer provided on a substrate by applying ink onto the substrate by an ink jet method. In D, the applied amount D of the dye contained in the ink to the ink receiving layer
Is in the following range: D <3.0 × 10 ⁻³ (ng / μm ³ ) The following characteristics are given as the dyes (a) and (b) contained in the ink: (a) Red dye Transmission at 545 nm Transmittance at 610 nm in an aqueous solution prepared to have a transmittance of 3.0% is 70.0
% Or more, and the transmittance at 435 nm is 50.0%
Water-soluble red dye having the following spectral characteristics, (b) Yellow dye: 95% transmittance at 610 nm in an aqueous solution prepared so that the transmittance at 435 nm is 20.0%.
A color filter characterized by containing a water-soluble yellow dye exhibiting the above-mentioned spectral characteristics in a weight ratio range of 20: 1 to 1: 1.
The ink receiving layer contains at least an acrylic monomer unit, and the acrylic monomer unit has the following general formula (1).

[0022]

Embedded image (However, R ¹ is H or CH ₃ , R ² is H or has 1 carbon atom.
The alkyl groups of 5 are shown. ), The ink-receiving layer containing the acrylic monomer unit contains a photopolymerization initiator, and the non-colored portion of the ink-receiving layer is preliminarily irradiated with light or irradiated with light and heat-treated to absorb ink. Including a step of reducing

Further, according to the present invention, an optically transparent ink receiving layer is formed on a transparent substrate, and then ink is applied to the receiving layer by an ink jet method to form pixels, thereby forming a pixel on the substrate. In a method of manufacturing a color filter comprising a plurality of colored pixels arranged on an optically transparent ink receiving layer, the ink has a boiling point of 150 to 150.
A water-soluble red dye (a) and a water-soluble yellow dye (b), which contains 10 to 60% by weight of a solvent at 250 ° C. and exhibits the following characteristics, and (a) a red dye having a transmittance of 3.0% at 545 nm. The transmittance of the prepared aqueous solution at 610 nm is 70.0.
% Or more, and the transmittance at 435 nm is 50.0%
Water-soluble red dye having the following spectral characteristics, (b) Yellow dye: 95% transmittance at 610 nm in an aqueous solution prepared so that the transmittance at 435 nm is 20.0%.
A method for producing a color filter, which comprises a water-soluble yellow dye having the above-mentioned spectral characteristics in a weight ratio of 20: 1 to 1: 1, wherein the dye (a) and the dye ( b) in the range of 10: 1 to 1: 1 by weight, and the total dye concentration in the ink is 1 to 15
% By weight, the amount D of the dye contained in the ink applied to the ink receiving layer is in the following range, and D <3.0 × 10 ⁻³ (ng / μm ³ ) contained in the ink The following characteristics of the dyes (a) and (b) are as follows: (a) Red dye: 70.0% in an aqueous solution prepared to have a transmittance of 3.0% at 545 nm.
% Or more, and the transmittance at 435 nm is 50.0%
Water-soluble red dye having the following spectral characteristics, (b) Yellow dye: 95% transmittance at 610 nm in an aqueous solution prepared so that the transmittance at 435 nm is 20.0%.
Containing a water-soluble yellow dye exhibiting the above-mentioned spectral characteristics in a weight ratio of 20: 1 to 1: 1; and the ink receiving layer containing at least an acrylic monomer unit, The acrylic monomer unit is represented by the following general formula (1)

[0024]

Embedded image (However, R ¹ is H or CH ₃ , R ² is H or has 1 carbon atom.
The alkyl groups of 5 are shown. ), The ink-receiving layer containing the acrylic monomer unit contains a photopolymerization initiator, and the non-colored portion of the ink-receiving layer is preliminarily irradiated with light or irradiated with light and heat-treated to absorb ink. Including a step of reducing

Further, the present invention is characterized by at least including the color filter, a panel substrate arranged to face the color filter, and a liquid crystal composition enclosed between the color filter and the panel substrate. It is a liquid crystal panel.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a method for manufacturing a color filter for liquid crystal according to the present invention, and shows an example of the constitution of the color filter for liquid crystal according to the present invention.

In the present invention, a glass substrate is generally used as the substrate, but it is not limited to the glass substrate as long as it has necessary properties such as transparency and mechanical strength as a color filter for liquid crystal. Absent.

FIG. 1A shows a glass substrate 1 on which a black matrix 2 is formed. As a method of forming the black matrix, when directly provided on the substrate, a method of forming a metal thin film by sputtering or vapor deposition and patterning by a photolithography process, and when provided on a resin composition, a general photolithography process However, the patterning method is not limited to these. First, a layer (not shown) containing a curable resin composition is formed on the substrate 1 on which the black matrix 2 is formed, and the layer is cured to form the substrate 1
The ink receiving layer 3 is formed thereon (FIG. 1 (b)).

As a material for forming the ink receiving layer 3, a compound containing at least a monomer consisting of the following structural unit (1) alone and / or a copolymer with another vinyl monomer is cured. Those are preferable.

[0031]

Embedded image (However, R ¹ is H or CH ₃ , R ² is H or has 1 carbon atom.
The alkyl groups of 5 are shown. ) Specific examples of the monomer composed of the structural unit represented by the above formula (1) include N-methylol acrylamide and N-
Examples thereof include, but are not limited to, methoxymethyl acrylamide, N-ethoxymethyl acrylamide, N-isopropoxymethyl acrylamide, N-methylol methacrylamide, N-methoxymethyl methacrylamide, and N-ethoxymethyl methacrylamide.

Other vinyl units include acrylic acid,
Methacrylic acid, methyl acrylate, acrylic acid esters such as ethyl acrylate, methyl methacrylate, methacrylic acid esters such as ethyl methacrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate,
Hydroxymethyl acrylate, hydroxy group-containing vinyl monomers such as hydroxyethyl acrylate, and other styrene, α-methylstyrene, acrylamide, methacrylamide, acrylonitrile, allylamine, vinylamine, vinyl acetate, vinyl propionate, etc. However, it is not limited to these.
The copolymerization ratio of the vinyl monomer in the copolymer of the structural unit (1) and the other vinyl monomer is preferably in the range of 95 to 5 mol%.

Other polymer compounds may be mixed with the above homopolymer or copolymer. Examples of such polymer compounds include polyvinylpyrrolidone, polyvinyl alcohol, polyvinyl acetal, polyurethane, carboxymethyl cellulose, polyester, polyacrylic acid (ester), hydroxyethyl cellulose, hydroxypropyl cellulose, and synthetic resins such as modified products thereof.
Further, natural resins such as albumin, gelatin, casein, starch, cationized starch, gum arabic and sodium alginate can be exemplified.

The compounding amount of the other polymer compound is as follows.
It is preferably 70% by weight or less based on the total amount of the resin constituting the receiving layer.

Further, the receiving layer 3 may contain various additives, if necessary. Specific examples of the additives include various surfactants, dye fixing agents (waterproofing agents), antifoaming agents, antioxidants, fluorescent whitening agents, ultraviolet absorbers, dispersants, viscosity adjusting agents, pH adjusting agents. , Antifungal agents, plasticizers and the like. These additives may be arbitrarily selected from conventionally known compounds according to the purpose.

As a method for forming the layer containing the above resin composition, spin coating, roll coating, bar coating, spray coating, dip coating or the like can be used. Further, after prebaking if necessary, coloring is performed by the ink jet method using each color ink of R, G, B containing the water-soluble dye (FIG. 1C). As the ink used for coloring, any of dyes other than the water-soluble dyes and pigments can be used in combination, and both liquid ink and solid ink can be used, but in the case of the present invention, in the case of water-based ink Is also very suitable.

In FIG. 1, 5 is an ink jet head, and 6, 7, and 8 are receiving layers colored with R, G, and B color inks.

Then, the receptive layers 6, 7 and 8 colored with ultraviolet rays or heat and ultraviolet rays are irradiated to cure them (see FIG. 1).
(D)), and a protective layer 9 is further laminated if necessary (FIG. 1).
(E)). As the protective layer 9, a resin material curable by light irradiation or heat treatment, an inorganic film formed by vapor deposition or sputtering, or the like can be used, and it has transparency as a color filter, and the subsequent ITO forming process. Any material can be used as long as it can withstand the alignment film forming process.

As a result, the color filter 10 of the present invention is
0 is completed.

As the ink jet system, a type using an electrothermal converter as an energy generating element, a type using a piezoelectric element, or the like can be used, and the coloring area and the coloring pattern can be set arbitrarily.

The ink receiving layer material preferably used in the present invention further contains a photopolymerization initiator, and the non-coloring portion corresponding to the black matrix is previously irradiated with light or exposed to light and heat treated to absorb the ink. It is preferable to impart a property of reducing As a result, it is possible to prevent troubles due to color mixture, color unevenness, etc. between pixels, which are likely to occur when forming R, G, and B images by the inkjet method, and to provide a low-cost, high-quality color filter. It becomes possible to manufacture. FIG. 2 shows a method of manufacturing a color filter substrate including a step of reducing the ink absorbency of the non-coloring portion. FIG. 2C shows the process. After the ink receiving layer 83 containing the photopolymerization initiator is formed on the substrate 1, the non-coloring portion 81 corresponding to the black matrix 2 is patterned through the photomask 4. The exposure reduces the ink absorbency of the non-coloring portion.

A non-coloring portion 81 corresponding to the black matrix 2 is used as a photomask for pattern exposure.
An article having an opening 90 for reducing the ink absorbability is used. At this time, considering that it is necessary to eject a large amount of ink in order to prevent color loss in the portion in contact with the black matrix 2, a mask having an opening width Y narrower than the width X of the black matrix 2 is used. It is preferable to use. The non-coloring portion 8 formed by this
The width of 1 is narrower than the width of the black matrix 2.

Hereinafter, the steps of FIGS. 2D to 2F are performed in the same manner as in FIG. 1 to form a color filter substrate.
Reference numerals 85, 86, and 87 are receiving layers colored with R, G, and B color inks.

The light irradiating means for forming the layer 81 in which the ink absorptivity of the light irradiating portion is lowered is not particularly limited, but in the present invention, deep UV light is particularly preferable, and light irradiating conditions 1 to It is about 3000 mJ / cm ² . Means such as an oven or a hot plate can be used for the heat treatment, and the temperature condition may be 50 ° C. to 180 ° C. for 10 seconds to 20 minutes. The photopolymerization initiator that imparts the ability to reduce the ink absorbability will be described below.

The photopolymerization initiator is not particularly limited, but onium salts and halogenated triazine compounds are preferably used. Specifically, onium salts include triphenylsulfonium hexafluoroantimonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium trifluoromethyl sulfonate, and their derivatives, and further diphenyliodonium hexafluoro. Examples thereof include, but are not limited to, fluoroantimonate, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethyl sulfonate, and derivatives thereof. Halogenated triazine compounds are common. Examples thereof include derivatives thereof, but of course the present invention is not limited to these.

The content of the above photopolymerization initiator is 0.01 to 20%, preferably 0.1 to 10% by weight based on the ink receiving layer material. A compound such as perylene or anthracene may be added as a sensitizer.

Next, a preferred method for ejecting ink and forming pixels by the ink jet method will be described with reference to FIGS. 3 and 4.

FIG. 3 is a block diagram showing the arrangement of an apparatus for drawing a colored portion of a color filter by the ink jet method. In FIG. 3, the CPU 21 is a head drive circuit 22.
The inkjet head 23 is connected via.
Further, the control program information in the program memory 24 is input to the CPU 21. The CPU 21 moves the inkjet head 23 to a predetermined position (not shown), brings a desired pixel position on the glass substrate 25 below the inkjet head, and ejects an ink droplet 26 of a desired color to the position to color the ink droplet 26. To do. By doing this for all pixel positions on the substrate 25, a color filter is manufactured.

FIG. 4 shows a process of forming a colored portion (pixel) by the ink jet method. The major difference from the conventional method (dyeing method) is that ink consisting of water, water-soluble solvent, and dye is selectively adhered only to the pixel forming part on the surface of the color filter substrate, and then water and organic solvent in the ink Is evaporated to form pixels. (FIG. 4).

The characteristic particularly required here is the adhesion between the colored portion and the color filter substrate. As described above, the ink (dyeing liquid) used in the inkjet method has a dye for the purpose of continuously and stably ejecting the ink from a minute nozzle and for the purpose of preventing clogging due to deposition of dye at the nozzle tip. Besides, an organic solvent is contained. Therefore, on the color filter substrate, the dye and the organic solvent will coexist temporarily, but the type of ink receiving layer used, the type of dye and the amount applied to the ink receiving layer, and further in the ink Depending on conditions such as the type of organic solvent contained (especially boiling point) and the like, the adhesion of the colored portion becomes insufficient, and peeling may occur during cleaning after coloring.

Therefore, as a result of intensive studies, the present inventors have found that in the method for producing a color filter by the ink jet method, the above-mentioned aspect is the theory, and as a more preferable aspect, the ink receiving layer contains at least a water-soluble acrylic monomer unit. When the amount D of the dye contained in the ink applied to the ink receiving layer satisfies the following range, the water-washing process after coloring can be performed without lowering the adhesion between the colored portion and the color filter substrate. It has been found that it is possible to obtain a good color filter that does not peel off at all during ultrasonic cleaning.

D <3.0 × 10 ^-3 (ng / μm ³ ) When the amount D of the dye applied to the ink receiving layer exceeds the above range, the adhesion of the colored portion is lowered and the dye is peeled off during washing. There is a possibility that it will end up.

The lower limit of the dye application amount D differs depending on the purpose, and is not particularly specified here, but if it is less than 6 × 10 ⁻⁵ , the solvent contained in the ink is If the kind and amount are within a specific range, there is no problem of peeling of the colored portion as described above, but the color reproduction range is narrowed and the image quality becomes dull, which is not preferable.

In the present invention, a water-soluble red dye (a) having the above-mentioned spectral characteristics and a water-soluble yellow dye (b) are used as the dyes used in the ink in a weight ratio of 3%.
By having both in the range of 0: 1 to 1: 1, the adhesiveness to the ink receiving layer containing the water-soluble acrylic monomer unit is good, and more preferable effects as described later can be exhibited.

The dyes of the ink used in the present invention have specific transmission spectra as described above, and specific examples of these dyes are shown in Tables 1-1 and 1-2.

[0056]

[Table 1]

[0057]

[Table 2] The amount of these dye compounds contained in the ink is 0.5 to 20% by weight, preferably 1 to 15% by weight.
Range. Further, the dye may include other dyes if necessary.

Here, the film thickness of the ink receiving layer, the amount of the dye applied on the receiving layer, and the method for measuring the spectrum of the dye aqueous solution will be described. 1. Measurement of film thickness (H) of ink receiving layer The film thickness of the ink receiving layer can be easily measured using a commercially available device. As an example, a stylus type film thickness meter (P-10
Profiler, manufactured by Tencor Co., Ltd.). 2. Dye Application Amount D on Receptor Layer In order to calculate the dye application amount, the amount per ink droplet ejected from the inkjet head is obtained in advance. The amount per one ink droplet can be measured by ejecting a fixed amount of ink from the inkjet head, measuring the weight, and dividing by the number of ejected ejections. The amount per ink droplet (Vd) thus obtained, the dye concentration (C) in the ink, the area of the portion colored by the ink dot (Da), the ink reception obtained by the above method The dye application amount D per unit volume of the ink receiving layer can be measured by the following formula based on the layer thickness (H) and the number of ink dots (Dn) forming one pixel.

Dye application amount D = (Vd × C × Dn) / Da × H 3. Measurement of Transmission Spectrum of Aqueous Dye Solution The transmission spectrum of a water-soluble dye that can be preferably used in the present invention can be measured by using a commercially available spectrophotometer.
Since some dyes change depending on the pH, it is preferable to set the pH to around 7.0.

In order to achieve the object of the present invention more efficiently, it is preferable to use water as the ink solvent and a solvent having the following characteristics. That is, the boiling point is preferably 1
The solvent at 50 ° C to 250 ° C is 10 to 60% by weight, and more preferably the solvent having a boiling point of 180 ° C to 250 ° C is 16 to 6%.
0.0% by weight.

As described above, the high boiling point solvent is added to the ink used for ink jet for the purpose of avoiding the clogging phenomenon due to the deposition of the dye at the tip of the head. However, if the ink containing a large amount of the high boiling point solvent is applied as it is to the color filter, the adhesion of the colored portion is deteriorated, which is not preferable. Therefore, as the solvent species contained in the ink, those satisfying the above physical properties are preferable.

On the other hand, when the amount of the solvent in the ink is too small, the dye may be deposited at the tip of the ink jet head, or the continuous ejection of the ink may be deteriorated due to the phenomenon such as the inclusion of bubbles in the ink jet head. It is also not preferable because it occurs.

Table 2 shows specific examples of preferred solvents.

[0064]

[Table 3] Further, the ink may be mixed with a nonionic, anionic, cationic or other surfactant, and in addition, an additive such as a pH adjustor or a fungicide may be added if necessary. good.

Further, the ink may contain a water-soluble resin. The resin to be contained has an average molecular weight of 100.
The range of 0 to 100,000 is preferable, and the range of average molecular weight of 1000 to 50,000 is more preferable. Those having an average molecular weight of 1,000 or less are not preferred because of poor adhesion, and those having an average molecular weight of 100,000 or more are also
It is not preferable because the viscosity of the ink is remarkably increased and the ink jetting property of the ink is deteriorated.

FIG. 5 shows a sectional view of a TFT color liquid crystal panel incorporating the color filter of the present invention.

The color liquid crystal panel includes a color filter 10
It is formed by putting together the substrate 14 facing 0 and enclosing the liquid crystal composition 12 between them. TFTs (not shown) and transparent pixel electrodes 13 are formed in a matrix inside one substrate of the liquid crystal panel. A color filter 100 is provided inside the other substrate 16 at a position facing the pixel electrode, and a transparent counter (common) electrode 10 is formed on one surface of the color filter 100. Further, an alignment film 11 is formed in the plane of both substrates, and by rubbing the alignment film 11, liquid crystal molecules can be aligned in a certain direction. The liquid crystal composition is filled in the gaps (about 2 to 5 μm) between the glass substrates. As the backlight 17, a combination of a fluorescent lamp and a scattering plate (neither of which is shown) is used, and a liquid crystal compound functions as an optical shutter that changes the transmittance of the backlight, thereby performing display.

[0068]

【Example】

Example A1 On a glass substrate provided with a black matrix having a large number of openings of 60 × 150 μm arranged, a mixture of N-methylolacrylamide and hydroxyethyl methacrylate (1: 1 (weight ratio)) was used as an ink receiving layer. A curable resin composition made of a polymer was spin-coated to a dry film thickness of 0.8 μm, and prebaked at 70 ° C. for 20 minutes. Then, using an inkjet printer, the R, G, B matrix patterns were colored under the following conditions with the following R, G, B inks.

Dye application amount D on the receiving layer: 7.
5 × 10 ⁻⁴ ng / μm ³ (using an inkjet head with a discharge amount of 27 ng per shot, 8 shots of ink per pixel (dye concentration: 6.
0%), the colored area (pixel) area at that time is 2
4650 μm ² and the volume of the ink receiving layer in the colored portion is 1
It was 7225 μm ³ . Then, the curing reaction was allowed to proceed by baking at 200 ° C. for 50 minutes to prepare a liquid crystal color filter.

R dye: CIDirect Red 80 + CIAcid
Yellow 104 (6: 4 (weight ratio)) G dye: CIAcid Green 9 B dye: CIAcid Blue 90 The ink formulation was as in Formulation Example 1 shown in Table 4. Evaluation Method Evaluation 1: Peeling of colored portion A liquid crystal panel was prepared using the above color filter, and washed in a water bath for 5 minutes using an ultrasonic cleaner with an output of 100 W (35 kHz). Next, the adhesion of the cleaning part was evaluated by grouping into the following three stages.

A: Adhesion is good (no peeling occurs in the central 100 pixels) B: Adhesion is a little poor (peeling 5 pixels or less in the central 100 pixels) C: Adhesion is poor (central Delamination occurs in 100 pixels or more than 6 pixels) Evaluation 2: Bleeding of colored portion The above color filter was left at 60 ° C. for 48 hours, and the degree of bleeding of the B pattern colored portion (increased area of the colored portion) was evaluated. The increase in the area of the colored portion is: A: less than 5% B: 5% or more, less than 10% C: 10% or more The evaluation results are shown in Table 6. Example A2 0.2 part by weight of triphenylsulfonium trifluoromethylsulfonate (TSP-105 manufactured by Midori Kagaku) was added to the ink receiving layer material used in Example A1 (Table 5,
Receptive layer formulation example 2), width of black matrix (40μ
m) through a photomask having an opening (30 μm) narrower than m), a part of the ink receiving layer on the black matrix is patterned and exposed with Deep UV light at an energy amount of 100 mJ / cm ² , and the ink is absorbed by the part. The sex was reduced. Otherwise, the color filter of Example A2 was prepared under the same conditions as in Example A1, and the same evaluation as in Example A1 was performed. Examples A3 to A17 Color filters of Examples A2 to A17 were prepared under the same conditions as those of Example A2 except that the dye, ink formulation, receiving layer forming conditions, and dye application amount were changed.
The same evaluation as in Example A1 was performed. Table 6 shows the evaluation results (the conditions for producing the color filter are shown in Table 3). Comparative Examples A1 to A5 The color filters of Comparative Examples A1 to A5 were prepared under the same conditions as those of Example A1 except that the dye, the ink formulation, the receiving layer forming conditions, and the dye application amount were changed. The same evaluation was performed. Table 6 shows the evaluation results (the conditions for producing the color filter are shown in Table 3).

[0072]

[Table 4]

[0073]

[Table 5]

[0074]

[Table 6]

[0075]

[Table 7]

[0076]

Since the present invention is configured as described above, a color filter having a high color contrast and a high color purity in a colored portion and having no bleeding in the colored portion can be manufactured by an inkjet method.

[Brief description of drawings]

FIG. 1 is a whole process diagram showing a manufacturing example of a color filter of the present invention, wherein (a) to (e) are partial process diagrams.

FIG. 2 is a whole process diagram showing another manufacturing example of the color filter of the present invention, in which (a) to (f) are partial process diagrams.

FIG. 3 is a block diagram showing a configuration example of an inkjet device for manufacturing a color filter used in the present invention.

FIG. 4 is an explanatory diagram showing a process of forming a pixel by an inkjet method, in which (a) shows a case where adhesion of a colored portion is good,
(B) shows a case where peeling of the colored portion occurs due to insufficient adhesion of the colored portion.

FIG. 5 is a schematic sectional view showing an example of a liquid crystal panel incorporating the color filter of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Black matrix 3 Ink receiving layer 4 Photomask 5 Inkjet head 6 Colored receiving layer 7 Colored receiving layer 8 Colored receiving layer 9 Protective layer 100 Color filter

Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G03F 7/033 G03F 7/033 (72) Inventor Koichiro Nakazawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Within the corporation

Claims (17)

[Claims] 1. A color filter ink for use in a color filter having a plurality of colored pixels arranged by applying the ink onto a substrate by an inkjet method, wherein the ink is a solvent having a boiling point of 150 to 250 ° C. 10 to 60
Water-soluble red dye (a) and water-soluble yellow dye (b), which contains the following properties by weight, and (a) red dye, in an aqueous solution prepared to have a transmittance of 3.0% at 545 nm. 70.0 at 610 nm
% Or more, and the transmittance at 435 nm is 50.0%
Water-soluble red dye having the following spectral characteristics, (b) Yellow dye: 95% transmittance at 610 nm in an aqueous solution prepared so that the transmittance at 435 nm is 20.0%.
An ink for a color filter, comprising a water-soluble yellow dye having the above-described spectral characteristics in a weight ratio of 20: 1 to 1: 1. 2. The ink for a color filter according to claim 1, wherein the dye (a) and the dye (b) are used together in a weight ratio of 10: 1 to 1: 1. 3. The color filter ink according to claim 1, wherein the total dye concentration in the ink is 1 to 15% by weight. 4. A color filter in which a plurality of colored pixels are arranged on an optically transparent ink receiving layer provided on a substrate by applying ink onto the substrate by an inkjet method, The amount D of the dye contained in the ink applied to the ink receiving layer is in the following range: D <3.0 × 10 ⁻³ (ng / μm ³ ) The dye (a) contained in the ink, ( b) The following characteristics: (a) Red dye The transmittance at 610 nm in an aqueous solution prepared to have a transmittance at 545 nm of 3.0% is 70.0.
% Or more, and the transmittance at 435 nm is 50.0%
Water-soluble red dye having the following spectral characteristics, (b) Yellow dye: 95% transmittance at 610 nm in an aqueous solution prepared so that the transmittance at 435 nm is 20.0%.
A color filter containing a water-soluble yellow dye satisfying the above-mentioned spectral characteristics in a weight ratio of 20: 1 to 1: 1. 5. The color filter according to claim 4, wherein the ink receiving layer contains at least an acrylic monomer unit. 6. The acrylic monomer unit has the following general formula (1): (However, R ¹ is H or CH ₃ , R ² is H or has 1 carbon atom.
The alkyl groups of 5 are shown. ) The color filter according to claim 5, wherein 7. The color filter according to claim 5, wherein the ink receiving layer containing the acrylic monomer unit contains a photopolymerization initiator. 8. The color filter according to claim 7, wherein the non-colored portion of the ink receiving layer undergoes a step of preliminarily irradiating with light or irradiating with heat and reducing the ink absorbability. 9. An optically transparent ink receiving layer formed on a substrate by forming an optically transparent ink receiving layer on a transparent substrate and then applying ink to the receiving layer by an ink jet method to form pixels. In a method for producing a color filter in which a plurality of colored pixels are arranged on a transparent ink receiving layer, the ink contains 10 to 60% of a solvent having a boiling point of 150 to 250 ° C.
Water-soluble red dye (a) and water-soluble yellow dye (b), which contains the following features by weight, and (a) red dye, in an aqueous solution prepared to have a transmittance of 3.0% at 545 nm. 70.0 at 610 nm
% Or more, and the transmittance at 435 nm is 50.0%
Water-soluble red dye having the following spectral characteristics, (b) Yellow dye: 95% transmittance at 610 nm in an aqueous solution prepared to have a transmittance at 435 nm of 20.0%.
A method for producing a color filter, comprising: a water-soluble yellow dye having the above-described spectral characteristics, in a weight ratio of 20: 1 to 1: 1. 10. The method for producing a color filter according to claim 9, wherein the dye (a) and the dye (b) are used together in a weight ratio of 10: 1 to 1: 1. 11. The total dye concentration in the ink is 1 to 15.
The method for producing a color filter according to claim 9, wherein the content is wt%. 12. The amount D of the dye contained in the ink applied to the ink receiving layer is in the following range: D <3.0 × 10 ⁻³ (ng / μm ³ ) contained in the ink The dyes (a) and (b) have the following characteristics: (a) Red dye: An aqueous solution prepared to have a transmittance of 3.0% at 545 nm has a transmittance of 70.0 at 610 nm.
% Or more, and the transmittance at 435 nm is 50.0%
Water-soluble red dye having the following spectral characteristics, (b) Yellow dye: 95% transmittance at 610 nm in an aqueous solution prepared to have a transmittance at 435 nm of 20.0%.
The method for producing a color filter according to claim 9, wherein a water-soluble yellow dye satisfying the above-mentioned spectral characteristics is contained in a weight ratio of 20: 1 to 1: 1. 13. The method for producing a color filter according to claim 12, wherein the ink receiving layer contains at least an acrylic monomer unit. 14. The acrylic monomer unit has the following general formula (1): (However, R ¹ is H or CH ₃ , R ² is H or has 1 carbon atom.
The alkyl groups of 5 are shown. ) The method for producing a color filter according to claim 12, wherein 15. The method for producing a color filter according to claim 14, wherein the ink receiving layer containing the acrylic monomer unit contains a photopolymerization initiator. 16. The method for producing a color filter according to claim 15, wherein the non-colored portion of the ink receiving layer is subjected to a step of preliminarily irradiating the material with light or irradiating the material with light to reduce the ink absorbability. 17. A color filter according to claim 4, a panel substrate provided opposite to the color filter, and a liquid crystal composition enclosed between the color filter and the panel substrate. A liquid crystal panel having at least one.