JPH11295516A - Manufacture of color filter and color filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a flexible color filter capable of providing the flexible color filter by a simple method not including photolithography in a process, improving the controllability at the time of forming a colored layer and coping even with fine and complicated picture element arrangement and to provide the flexible color filter of high resolution provided with high smoothness and high transmissivity. SOLUTION: In this manufacturing method of a color filter, a substrate 1 on which a light transmissive plastic film 2, a light transmissive conductive film 3 and an optical semiconductor thin film 4 are successively laminated is used and the substrate 1 is immersed in a water-based liquid 10 containing a color electrodeposition material. A current or an electric field is supplied to the light transmissive conductive film, the substrate 1 is irradiated with light and a colored electrodeposition film 5 composed of the coloring electrodeposition material is formed at a light irradiation part.

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 used for various display elements such as a CCD camera and a liquid crystal display element and a color sensor, and a color filter. The present invention relates to a method for producing a color filter that forms a colored layer or a black matrix by a deposition method, and a high-resolution color filter produced by this method.

[0002]

2. Description of the Related Art At present, as a method for producing a color filter, (1) a dyeing method, (2) a pigment dispersion method, (3) a printing method, (4) an ink jet method, and (5) an electrodeposition method are known. I have. (1) In the dyeing method, a layer of a water-soluble polymer is formed on a glass substrate, patterned into a desired shape through a photolithography process, and then immersed in a dye solution to obtain a colored pattern. . This operation was repeated three times, and R (red). G (green). B (blue). To obtain a color filter layer. A color filter obtained by this method has a high transmittance, a wide range of hues, and a high degree of perfection, and is therefore frequently used in a color solid-state imaging device (CCD). However, since a dye is used, the light resistance is inferior and the number of manufacturing steps is large. Therefore, for a liquid crystal display device (LCD), the pigment dispersion method has been used. (2) The pigment dispersion method is the most mainstream color filter manufacturing method in recent years. First, a resin layer in which a pigment is dispersed is formed on a glass substrate, and this is patterned through a photolithography process. This was repeated three times. G. FIG. B.
To obtain a color filter layer. Although this manufacturing method has a high degree of technology perfection, it has disadvantages in that the number of steps is large and the cost is high. (3) In the printing method, a pigment is dispersed in a thermosetting resin, and printing is repeated three times. G. FIG. B. And then applying heat to cure the resin to obtain a color filter layer. This method is described in R. G. FIG. B. As long as the layer formation step is limited, it is a simple method without using a photolithography method, but the resolution and thickness uniformity of the obtained color filter are inferior to color filters manufactured by other methods. There is a disadvantage that. (4) In the ink-jet method, after forming an ink-receiving layer of a water-soluble polymer and subjecting it to a hydrophilization / hydrophobization treatment,
Ink is sprayed on the hydrophilized portion by an ink jet method. G. FIG. B. To obtain a color filter layer.
This method is also described in R. G. FIG. B. Photolithography is not required if the layer is limited, but has the disadvantage that the resolution of the obtained color filter is inferior to that obtained by other methods.
Further, when ink is sprayed, there is a high probability that small droplets of the ink are scattered and the adjacent filter layers are mixed in color, and the position accuracy is inferior. (5) In the electrodeposition method, a high voltage of about 70 V is applied to a pre-patterned transparent electrode in an electrolytic solution in which a pigment is dispersed in a water-soluble polymer to form an electrodeposition film by electrodeposition coating. And this is repeated three times. G. FIG. B. (See, for example, JP-A-5-119).
209 and JP-A-5-157905). In this method, it is necessary to pattern a transparent electrode in advance by photolithography, and since this is used as an electrode for electrodeposition, the shape of the pattern is limited and T
There is a disadvantage that it cannot be used for FT liquid crystal. In general, a color filter cannot be used only with a color filter layer, and it is necessary to cover each color filter pixel with a black matrix. Usually, photolithography is used to form the black matrix, which is one of the major factors for increasing the cost.

[0003]

As a means for solving the above-mentioned problems, the present inventors have found a method for producing a color filter by an electrodeposition technique using photovoltaic power. (Japanese Patent Application No. 9-29746)
6). This manufacturing method is a simple method that does not use photolithography, and has higher controllability than a conventional method. Further, the color filter obtained by this manufacturing method has higher resolution and higher smoothness than conventional color filters.
An object of the present invention is to improve the manufacturing method, reduce the weight and cost of the color filter, and provide a more versatile color filter.

That is, an object of the present invention is to provide a flexible color filter by a simple manufacturing method that does not include a photolithography step. It is another object of the present invention to provide a method of manufacturing a flexible color filter which has high controllability at the time of forming a colored layer and can cope with fine and complicated pixel arrangement. It is another object of the present invention to provide a high-resolution flexible color filter having high smoothness and high transparency.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies on an electrodeposition technique using photovoltaic power and a method for manufacturing an optical semiconductor thin film exhibiting photovoltaic power. A light-transmissive conductive film is formed on the substrate, and a substrate on which an optical semiconductor thin film is further formed is used, and a colored layer is formed on the substrate by an electrodeposition method using photovoltaic power.
They have found that a flexible color filter can be easily manufactured, and based on this finding, have completed the present invention.

That is, the present invention uses a substrate in which a light-transmitting plastic film, a light-transmitting conductive film, and an optical semiconductor thin film are sequentially laminated, and immerses the substrate in an aqueous liquid containing a colored electrodeposition material. This is a method for producing a color filter, comprising the steps of applying a current or a voltage to a light-transmitting conductive film, irradiating a substrate with light, and forming a colored electrodeposition film made of a colored electrodeposition material on a light-irradiated portion.

[0007] The method for producing a color filter of the present invention comprises:
By applying a bias voltage to the light-transmitting conductive film in advance and irradiating light to generate photoelectromotive force only in the light-irradiated part, changing the pH of the aqueous liquid near the light-irradiated part of the substrate, and responding to this pH change A colored electrodeposition film is formed on a substrate by utilizing the difference in solubility of the colored electrodeposition material. This process,
For example, if it is repeated three times corresponding to the R layer, the G layer, and the B layer,
A high-resolution color filter composed of three primary colors can be easily manufactured.

Further, since the optical semiconductor thin film is exposed in the region where the colored layer is not formed, after forming the colored layer, a voltage is applied to the conductive film in an aqueous liquid containing a black electrodeposition material. By this (with or without light at this time)
The black matrix can be easily formed only in the unformed region of the coloring layer. In addition, when the light-transmitting conductive film is subjected to ionization treatment, the adhesiveness between the conductive film and the optical semiconductor thin film can be increased, and a stable and flexible color filter can be manufactured. Furthermore, if an n-type optical semiconductor thin film made of titanium oxide having high photoactivity is used as the optical semiconductor thin film, a flexible and high-resolution color filter can be stably manufactured without causing thermal damage to the plastic film. Can be.

Further, the present invention is a color filter in which a light-transmitting plastic film, a light-transmitting conductive film, an optical semiconductor thin film, and a coloring layer are sequentially laminated. With a color filter having such a configuration, it is possible to provide a versatile color filter that is lightweight and has shape flexibility. In addition, a high-resolution color filter having high transmittance and high smoothness can be provided.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be further described with reference to embodiments. In the present invention, a substrate in which a light-transmitting plastic film, a light-transmitting conductive film, and an optical semiconductor thin film are laminated in this order is used. As the light-transmitting plastic film, a light-transmitting plastic film having flexibility or flexibility is used. For example, films made of polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyether imide, polyether ether ketone, polyphenylene sulfide, polyarylate, polyimide, polycarbonate and the like can be mentioned. Particularly, polyethylene terephthalate is preferred. Here, the term "light-transmitting property" refers to a property of transmitting visible light, that is, a property of not absorbing visible light. The same applies hereinafter.

The light-transmitting conductive film functions as an electrode to which a current or a voltage is applied. The materials used are IT
O (indium-tin oxide), tin dioxide and the like. Among them, ITO is preferable because of its high conductivity and transparency. The light-transmitting conductive film can be formed on a plastic film by a conventionally known method such as an evaporation method, a sputtering method, and a CVD method. Further, it is preferable that the light-transmitting conductive film be subjected to ionization treatment, since the adhesiveness to the optical semiconductor thin film can be enhanced. Examples of the ionization treatment include an ozone treatment and a discharge treatment.

As the optical semiconductor thin film, any thin film which generates a photovoltaic force upon irradiation with light and has optical transparency can be used. Optical semiconductors include an n-type optical semiconductor and a p-type optical semiconductor, and any optical semiconductor can be used in the present invention. Furthermore, it is preferable to use an optical semiconductor having a laminated structure using a pn junction or a pin junction, because an electromotive voltage can be increased and a large current can be passed, so that a color filter with higher resolution can be obtained. The optical semiconductor thin film used in the present invention may be made of an inorganic optical semiconductor or an organic optical semiconductor. Examples of the inorganic optical semiconductor include Ga-N, diamond, C-BN, SiC, ZnSe, TiO ₂ , Z
nO and the like. Examples of the organic optical semiconductor include polyvinyl carbazole, polyacetylene, and the like. Among them, oxide optical semiconductors such as TiO ₂ and ZnO are preferable because they are not oxidized. In particular, TiO ₂ is preferable because it has high light sensitivity and high transmittance. The optical semiconductor thin film can be formed using a conventionally known thermal oxide film method, sputtering method, electron beam evaporation method, or the like. However, in order to form a film without causing thermal damage to the plastic film, the film needs to be formed by heat treatment at 100 ° C. or lower.

For example, to form an n-type optical semiconductor thin film using TiO ₂ , usually, about 500
Sintering at 200 ° C.
It is necessary to heat-treat the substrate at a temperature of ° C. This will damage the plastic film. Therefore, in the present invention, it is preferable to perform a reduction treatment on TiO ₂ in advance and use an anatase-type TiO ₂ crystal having high optical activity. If a crystal having high optical activity is used, an optical semiconductor thin film with high photosensitivity can be manufactured by low-temperature heat treatment. For example,
Anatase-type TiO ₂ crystals are dispersed (or dissolved) in a solvent, and this dispersion (solution) is applied on a conductive thin film and dried at 100 ° C. or less to produce a high-sensitivity n-type optical semiconductor thin film. it can. When anatase-type TiO ₂ is subjected to a reduction treatment, an oxygen atom is eliminated to form TiO _2-x , and the optical activity is further increased. As a method of the reduction treatment, a method of performing a heat treatment in an atmosphere of hydrogen gas may be mentioned. The heating condition is heating at about 500 ° C. for 1 hour (J. Electrochem. Soc., Vol. 1).
41, No. 3, p. 660, 1994, Y.C. Hamas
(described in aki et al.) and the like. However, if the heat treatment is performed while flowing the hydrogen mixed nitrogen gas at a predetermined flow rate, the treatment can be performed at a relatively low temperature in a short time. For example, TiO ₂ powder is mixed with 3% hydrogen mixed nitrogen gas at a flow rate of 1 liter / mi.
n at a temperature of about 360 ° C. for 10 minutes while flowing at a low temperature.
Can be reduced to _2-x .

Next, the colored electrodeposition material contained in the aqueous liquid in which the substrate is immersed will be described. The colored electrodeposition material includes at least a ionic molecule whose solubility changes due to a change in the pH of the solution and a coloring material such as a dye, a pigment, or a pigment, which is a coloring molecule for forming a colored electrodeposition film. . The coloring material itself may be an ionic molecule, and in this case, the colored electrodeposition material may be composed only of the coloring material. The ionic molecule may be an anionic molecule or a cationic molecule, and is selected according to the polarity of the optical semiconductor thin film used.

Which of the ionic molecules is selected as the electrodeposition material can be determined based on the change characteristic of the solubility corresponding to the change of the pH of the ionic molecule. The electrodeposition material used in the present invention depends on the pH change of the solution,
Those having the property of rapidly changing solubility are preferred.
For example, it is preferable that the solution changes its state (dissolved state → precipitated or precipitated → dissolved state) in response to a pH change of ± 1.0 of the solution, more preferably, in response to a pH change of ± 0.5. If an ionic molecule having such a solubility property is used as an electrodeposition material, an electrodeposition film can be produced more quickly,
Further, an electrodeposition film having excellent water resistance can be produced. Further, the ionic molecules used as the electrodeposition material undergo a state change (dissolved state → precipitation change and precipitation →
Change in dissolved state), ie, p
It is preferable that the change to the precipitation state corresponding to the decrease or increase of H is steep, and the change to the dissolved state corresponding to the increase or decrease of the pH is slow because the stability of the electrodeposited film is improved.

The ionic coloring materials include triphenylmethanephthalide, phenosadine, phenothiazine, and the like.
Fluorescein type, indolylphthalide type, spiropyran type, azaphthalide type, diphenylmethane type, chromenopyrazole type, leuco auramine type, azomethine type, rhodamine lactal type, naphtholactam type, triazene type, triazole azo type, thiazole azo type, azo system,
Oxazine, thiazine, benzothiazole azo,
Examples include quinone imine dyes and hydrophilic dyes having a carboxyl group, an amino group, or an imino group.

For example, rose bengal and eosin, which are fluorescein dyes, are reduced and dissolved in an aqueous solution having a pH of 4 or more, but are oxidized and precipitate in an aqueous solution having a pH of less than 4. Further, an oxazine-based basic dye Cathilon Pure Blue 5GH
(CI Basic Blue 3) and thiazine-based basic dye methylene blue (CI Basic BL 1).
ue 9) is in an oxidized state and dissolved in water having a pH of 10 or less, but is in a reduced state in water having a pH of 10 or more and is insolubilized and precipitated. Although there is no such structural change,
Generally, the solubility of a hydrophilic dye having a carboxyl group, an amino group, or an imino group greatly changes due to a change in pH of an aqueous solution. For example, a water-resistance-improved inkjet dye having a carboxyl group is soluble in water having a pH of 6 or more, but is insoluble in water having a pH of less than 6 and precipitates.

When the colored electrodeposition material comprises a pigment and an ionic molecule, the ionic molecule is preferably a polymer capable of forming a transparent film. For example, a polymer having an anionic carboxyl group, a polymer having a cationic amino group or an imino group, and the like can be given. A water-soluble acrylic resin, which is a kind of polymer having a carboxyl group, is soluble in water having a pH of 6 or more, but is insoluble in water having a pH of less than 6, and precipitates. By dispersing the pigment in this polymer,
When the polymer is electrodeposited on the substrate, the pigment is taken in to form a film, so that a colored electrodeposition film is formed on the substrate. The polymer used for the electrodeposition material of the present invention has an appropriate hydrophilicity for dissolving or dispersing in an aqueous liquid, and an appropriate amount for once dissolving or dissolving in an aqueous liquid after forming an electrodeposition film. Must have hydrophobicity. Therefore, the polymer has both a hydrophobic group and a hydrophilic group in the structure. As a guide for a polymer satisfying such a function, the number of the hydrophobic groups of the monomer constituting the polymer is in the range of 40 to 80% of the total of the hydrophilic group and the hydrophobic group of the monomer. In addition, 50% or more of the hydrophilic group portion changes from a hydrophilic group to a hydrophobic group due to a change in pH, and one having an acid value of 30 to 600 has a precipitation property.
It is preferable in terms of the stability of the electrodeposited film. The polymer may be composed of one kind of monomer or a copolymer composed of two or more kinds of monomers.

As the colored electrodeposition material, a mixture of two or more ionic molecules having the above characteristics (including a mixture of homopolar molecules and a mixture of heteropolar molecules) can also be used. A mixture of an on dye and a pigment having the above properties,
Mixtures composed of various combinations, such as a mixture of an ionic polymer having the above characteristics and a colorant, can be used. Even if the material itself does not have the ability to form an electrodeposition film, by combining it with an ionic molecule having the above properties,
It can be taken in during the formation of the electrodeposited film and become a component for forming the colored electrodeposited film. When the colored electrodeposition material is composed of an ionic polymer and a coloring material, if the solid content by weight of the coloring material is from 30% by weight to 95% by weight, the stability of the colored electrodeposition film and the color tone of the coloring layer are improved. It is preferable in that it becomes sufficient.

Examples of colored electrodeposition materials containing two or more coloring materials are shown below. A mixture of molecules of the same polarity, for example, an anionic molecule capable of forming an electrodeposition film, an aqueous solution of a mixture of rose bengal (red) and an anionic molecule brilliant blue (blue) having no ability to form an electrodeposition film, is mixed with an n-type light in an aqueous solution. When the substrate on which the semiconductor thin film is laminated is immersed, and a current or the like is applied so that the substrate has a positive potential and light irradiation is performed, a purple electrodeposited film same as the solution is formed on the light irradiation portion. This is because Brilliant Blue is incorporated into Rose Bengal, which has the ability to form an electrodeposited film, and the film is formed. As described above, when two or more kinds of molecules having the same polarity are used as a mixture, it is sufficient that at least one kind of ions has an electrodeposition film forming ability.

A mixture of molecules having different polarities, for example, ProFast Jet, which is anionic and capable of forming an electrodeposited film.
Catilon Pure Blue 5GH, which is cationic and has the ability to form an electrodeposition film with Yellow2 (yellow)
The substrate on which the n-type optical semiconductor thin film is laminated is immersed in an aqueous solution mixed with (blue), and a current or the like is applied so that the substrate has a positive potential and light irradiation is performed. A deposited film is formed. On the other hand, when light irradiation is performed while supplying a current or the like so that the substrate has a negative potential, a blue electrodeposition film (Cathilon Pure Blue) is formed on the light irradiation portion.
An electrodeposition film of 5 GH is formed. As described above, when a mixture of molecules of different polarities is used, if the polarity of the optical semiconductor thin film and the polarity of the applied voltage are changed, an electrodeposited film of a different color may be formed using the same colored electrodeposition material. it can.

When a water-insoluble pigment is used as the coloring material of the colored electrodeposition material, the pigment is used in an aqueous solution of an ionic polymer material capable of forming an electrodeposition film, for example, a water-soluble acrylic resin or a water-soluble styrene resin. What is necessary is just to disperse and use. The pigment is taken in when the water-soluble polymer forms the electrodeposited film, and a colored electrodeposited film is produced. As the pigment, any conventionally known pigment can be used.

These colored electrodeposition materials are used after being dissolved or dispersed in an aqueous liquid. Here, the aqueous liquid refers to a liquid containing water as a main component and to which various additives are added within a range that does not impair the effects of the present invention.

For the purpose of increasing the electrodeposition speed, an electrolyte may be added to the aqueous liquid in addition to the colored electrodeposition material. The addition of electrolyte increases the conductivity of the solution. As a result of the study by the present inventors, the conductivity in the aqueous liquid is correlated with the electrodeposition speed (in other words, the amount of electrodeposition) (FIG. 1). The film becomes saturated when the film thickness becomes large and the electric conductivity becomes about 100 mS / cm ² . Therefore, by adding ions that do not affect the formation of the electrodeposited film, for example, Na ⁺ ions or Cl ⁻ ions, the electrodeposition speed can be increased.

The pH of the aqueous liquid before light irradiation is preferably set within a range of ± 2 from the pH at which the state of the electrodeposition material used changes. If the pH of the aqueous liquid is set in such a range, the dissolution of the colored electrodeposition material in the aqueous liquid becomes saturated before the electrodeposition film is formed. As a result, once the electrodeposited film is formed, it is difficult to redissolve in the liquid after the film is formed, so that the electrodeposited film can be manufactured stably. On the other hand, at the time of forming the electrodeposited film, if the colored electrodeposition material is in an unsaturated state, even if the electrodeposited film is once formed, the film may start to redissolve as soon as supply of current or the like is stopped. . The pH of the aqueous liquid is adjusted to the above range by adding an acidic or alkaline substance which does not affect the electrodeposition characteristics.

When the substrate is immersed in the aqueous liquid, it is sufficient that at least the optical semiconductor thin film is in contact with the aqueous liquid. Even if the entire substrate is completely immersed in the liquid, only the optical semiconductor thin film is immersed in the liquid. It may be in contact.

Next, a description will be given of the pH change of the aqueous liquid in the vicinity of the substrate, and the mechanism of the formation of the colored electrodeposition film. Generally, when donating soaked current or voltage platinum electrode in an aqueous solution, OH in the aqueous solution of the vicinity of the anode ^-
The ions are consumed to become O ₂ , and the hydrogen ions increase to p
H decreases. This is because the following reaction in which the hole (p) and the OH ^- ion are linked occurs near the anode. 2OH ⁻ + 2p ⁺ → 1/2 (O ₂ ) + H ₂ O However, for this reaction to occur, a certain voltage (threshold voltage) is required.
Is required, the reaction proceeds and the pH in the aqueous solution changes only after exceeding the threshold voltage.
Decreases and the pH increases near the cathode). In the present invention, while applying a bias voltage by applying a current or voltage to the substrate in advance, photoirradiation is caused in the optical semiconductor by light irradiation, and only the light irradiation portion is set to a potential exceeding the threshold voltage,
The above reaction proceeds only in the aqueous solution near the light irradiation part of the substrate. As a result of the progress of the reaction, the pH of the aqueous solution near the light-irradiated portion changes, and the solubility of the colored electrodeposition material changes accordingly, and a colored electrodeposition film is formed only in the light-irradiated portion.

Therefore, in the present invention, the magnitude of the current or voltage previously supplied to the substrate (light-transmitting conductive film in the substrate) compensates for the potential generated in the substrate by the photovoltaic power generated by the optical semiconductor thin film, Need to be set so that the potential of the reference voltage reaches the threshold voltage. On the other hand, the current or voltage previously supplied to the substrate (the light-transmitting conductive film in the substrate) is
It is necessary to set the size not to exceed the Schottky barrier. If the current or voltage supplied to the substrate in advance is too large, the Schottky barrier is broken, current flows also in the area not irradiated with light, and an electrodeposition film is formed on the entire area of the optical semiconductor substrate, and the color electrodeposition film is formed. This is because the arrangement cannot be controlled. For example, the photovoltaic power of TiO ₂ is about 0.6 V
Therefore, if the coloring material is electrodeposited at 2.0 V,
When light irradiation is performed while applying a bias voltage of 1.4 V, the potential of the light irradiation portion of the substrate (optical semiconductor film) becomes 0.6 V + 1.4.
V = 2.0V, exceeding the threshold voltage required for electrodeposition,
A colored electrodeposition film is formed only on the light irradiation part.

In a conventional method for manufacturing a color filter using an electrodeposition technique, for example, the methods described in JP-A-5-119209 and JP-A-5-157905, the electrodeposition voltage is from 20 V to 80 V. Highly, a polymer is used as an electrodeposition material, and an electrodeposition film is formed using a redox reaction of the polymer. In the present invention, since the electrodeposition film is formed by the above mechanism, the substrate (optical semiconductor thin film) at the time of electrodeposition is formed.
Voltage can be below the Schottky barrier,
As a result, it is possible to provide a manufacturing method which has high controllability and can cope with fine pixel arrangement. The voltage of the substrate (optical semiconductor thin film) at the time of electrodeposition is preferably 5 V or less.

Next, the combination of an optical semiconductor and a colored electrodeposition material will be described. In the present invention, in the formation of photovoltaic,
A Schottky barrier generated at an interface in contact with an optical semiconductor and a barrier of a pn junction or a pin junction are used. FIG. 2A schematically shows a Schottky barrier generated at the interface between the n-type optical semiconductor and the aqueous liquid, and FIG. 2B schematically shows a pin junction barrier. For example, when an n-type optical semiconductor is used (FIG. 2A), when the n-type optical semiconductor side is made negative,
Since the current flows in the forward direction, the current flows, but conversely,
When the n-type optical semiconductor side is positive, that is, a Schottky junction between the n-type optical semiconductor and the aqueous liquid forms a barrier, and no current flows. However, even in a state where the current does not flow with the n-type optical semiconductor side being positive, when light is irradiated, electron-hole pairs are generated from the n-type optical semiconductor thin film, the holes move to the solution side, and the current flows. In this case, the material to be electrodeposited must be an anionic molecule because the n-type optical semiconductor is set at a positive potential. Accordingly, a combination of an n-type optical semiconductor and an anionic molecule is formed, and conversely, a cation is electrodeposited in a p-type optical semiconductor. In particular, it is preferable to use a colored electrodeposition material containing a compound having a carboxyl group when an n-type optical semiconductor is used and a compound having an amino group or an imino group when a p-type semiconductor is used. pn
When a junction or pin junction semiconductor thin film is used, current or voltage is applied so that the semiconductor film portion is in the forward direction and the interface with the liquid is in the opposite direction.

Next, a means for supplying a current or a voltage to the light transmitting conductive film will be described. In order to supply a current or a voltage to the light-transmitting conductive film, it is necessary to provide an energizing path for supplying the current or the voltage to a side edge or the like of the conductive film as shown in FIG. A potentiostat or the like is used for supplying current or voltage.

Next, means for irradiating the substrate with light will be described. Light irradiation is performed from the back of the substrate. Since it is necessary to form a colored electrodeposition film corresponding to the pixel arrangement of the color filter, light is partially irradiated through a photomask or the like.
Any light source can be used as long as it provides light having a wavelength sensitive to the optical semiconductor used. For example, a mercury lamp, a mercury xenon lamp, a He—Cd laser, a N ₂ laser, an excimer laser, or the like capable of irradiating light with a wavelength of 400 nm or less may be used as the light source.

In the color filter of the present invention, if desired, a black matrix may be formed in a region where no colored layer is formed. In the present invention, since the optical semiconductor is exposed in the region where the colored layer is not formed, it is preferable to use this to form a black matrix by a similar electrodeposition method since the black matrix can be formed easily and at low cost. . Specifically, if the substrate on which the coloring layer is already formed is immersed in an aqueous liquid containing a black electrodeposition material for forming a black matrix, and a potential exceeding a threshold voltage is applied to the conductive film of the substrate, the coloring is performed. A black matrix can be formed in an unformed region of the layer. When a voltage lower than the threshold voltage (the same voltage as when forming the colored electrodeposition film) is provided,
When the substrate is irradiated with light from the back, a black matrix can be similarly formed in a region where the colored layer is not formed. Examples of the black electrodeposition material include a mixture of carbon black and the ionic polymer. When a black matrix is formed by this method, a colored electrodeposition material is selected so that the colored layer becomes insulating.

In addition, the black matrix can be formed by a conventionally known photolithography method, a method using an ultraviolet curable resin, or the like. When a black matrix is formed from an ultraviolet curable resin, a color filter is immersed in a monomer solution of an ultraviolet curable resin in which a black pigment or the like is dispersed, and ultraviolet light is irradiated from the back surface of the substrate, and ultraviolet light is applied only to a region where the colored layer is not formed. A black matrix made of a cured resin can be formed.

FIG. 4 is a schematic view of a process for manufacturing the color filter of the present invention. FIG. 5 is a schematic view showing one embodiment of a colored electrodeposition film forming step. The present invention will be described with reference to FIGS. A substrate 1 in which a light-transmitting plastic film 2, a light-transmitting conductive film 3, and an optical semiconductor thin film 4 are laminated in this order is prepared (A). Next, this substrate 1 is immersed in an aqueous liquid 10 containing a colored electrodeposition material so as to face the counter electrode 11 as shown in FIG. In this state, an electric current is supplied from the potentiostat 12 to the light-transmitting plastic film, and light is partially irradiated from the back surface of the light-transmitting plastic film via the photomask 13.
A photoelectromotive force is generated in the light-irradiated portion of the optical semiconductor thin film, and the colored electrodeposition film 5 (colored layer) is formed only in this portion, and a monochromatic color filter is formed (B). Further, when this step is repeated a plurality of times, a color filter including the plurality of coloring layers 6 and the coloring layers 7 is formed (C).

Next, using the same apparatus as that shown in FIG. 2, the color filter is immersed in an aqueous liquid 10 containing a black electrodeposition material, an electric current is supplied from a potentiostat 12, and a light-transmitting plastic is formed. Irradiate light from the back. A black matrix 8 made of a black electrodeposition film is formed in the region where the colored layer is not formed (D). Thereafter, if desired, a protective layer 9 may be formed (E). Thus, a color filter having a black matrix can be easily manufactured without using photolithography. In this manner, a light-transmitting plastic film, a light-transmitting conductive film, an optical semiconductor thin film, and a colored layer are laminated in this order to produce a high-resolution, high-smoothness, high-resolution color filter. it can.

The application field of the color filter of the present invention is not particularly limited, and the liquid crystal display device (LCD), solid-state image display (CCD), electroluminescence display device, gradation display device, plasma display panel, spectral device, light control It can be used as various color filters in vessels and the like. For example, it can be used for personal computers, word processors, liquid crystal color televisions and the like. Since the color filter of the present invention is lightweight and has flexibility in shape, it is particularly suitable for use as a color filter for portable equipment, notebook computers and the like.

[0038]

EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited thereto. Example 1 After washing a 125 μm-thick PET film with ITO (manufactured by Tokyo Oike Kogyo) with water, it is irradiated with ozone for about 15 minutes using an ozone cleaning device (manufactured by Nippon Laser Electronics). Using a dispersion liquid (manufactured by Nippon Soda) in which anatase-type titanium oxide crystal having high optical activity is dispersed in a solution, it is applied on a film with ITO by a dip coating method. next,
When this film was heated at 60 degrees for 30 minutes, IT
A thin film of titanium oxide was formed on O. Meanwhile, ITO
The coating film of titanium oxide was peeled off from the back surface where no was adhered. An energization path as shown in FIG. 3 was provided on the ITO and used as a substrate.

A substrate prepared in this manner was treated with a styrene-acrylic acid copolymer (molecular weight 13,000, hydrophobic group /
(Hydrophilic group + hydrophobic group) molar ratio 65%, oxidation 150) and azo red ultrafine pigment were added in a weight ratio of 1 to 10 of solid content.
And immersed in an aqueous solution dispersed at a ratio of 3 and placed in a three-pole arrangement generally used in the field of electrochemistry as shown in FIG. A TiO ₂ electrode is used as a working electrode with respect to the saturated calomel electrode. A mercury-xenon lamp (Yamashita Denso, light intensity of 365 nm) is supplied from the back of the substrate while applying a voltage from a potentiostat so that the working electrode becomes 1.7 V. 5
(0 mW / cm ² ) through a photomask for 10 seconds. A red electrodeposited film was formed on the light irradiated portion of the TiO ₂ surface.

Next, the substrate on which the red electrodeposition film is formed is
Styrene-acrylic acid copolymer (molecular weight 13,000,
Hydrophobic group / (hydrophilic group + hydrophobic group) molar ratio 65%, oxidation 15
0) and a phthalocyanine green-based ultrafine pigment were immersed in an aqueous solution in which the solid content weight ratio was 1:10. Similarly, a TiO ₂ electrode is used as a working electrode for the saturated calomel electrode, and the working electrode is set to 1.7 V, and a mercury xenon lamp (Yamashita Denso, wavelength 3
When a light intensity of 65 nm (50 mW / cm ² ) was irradiated with light through a photomask for 10 seconds, a green electrodeposited film was formed on the light irradiated portion of the TiO ₂ surface.

Next, the substrate on which the red and green electrodeposition films were formed was treated with a styrene-acrylic acid copolymer (having a molecular weight of 1).
3,000, hydrophobic group / (hydrophilic group + hydrophobic group) molar ratio of 65
%, Oxidized 150) and a phthalocyanine blue-based ultrafine pigment were immersed in an aqueous solution in which the solid content weight ratio was 1:10. Similarly, for a saturated calomel electrode, T
The iO ₂ electrode is used as a working electrode, and the working electrode is 1.7
The substrate was irradiated with a mercury xenon lamp (manufactured by Yamashita Denso, light intensity at a wavelength of 365 nm, 50 mW / cm ² ) for 10 seconds through a photomask. A blue electrodeposited film was formed on the light irradiated portion of the TiO ₂ surface. Thus, a color filter layer of three primary colors having an R layer, a G layer, and a B layer was formed.

Next, after washing the color filter with pure water, a styrene-acrylic acid copolymer (having a molecular weight of 13,
000, molar ratio of hydrophobic group / (hydrophilic group + hydrophobic group) 65%,
Oxidation 150) and carbon black powder (average particle size 80
nm) was immersed in an aqueous solution dispersed at a solid content ratio of 1:10. Similarly, when a TiO ₂ electrode was used as a working electrode with respect to the saturated calomel electrode, and a voltage was applied to the working electrode at 2.0 V, a black electrodeposition film was formed in a region where no colored layer was formed. After washing the color filter, a protective layer was coated on the color filter. Thus, three primary color filters covered with the black matrix were produced. The transmittance of the obtained color filter was 80% or more, and the surface had high smoothness.

Example 2 A color filter of three primary colors (before forming a black matrix) prepared in the same manner as in Example 1 was washed with pure water, and then a styrene-acrylic acid copolymer (molecular weight: 13,000) was used.
0, hydrophobic group / (hydrophilic group + hydrophobic group) molar ratio 65%, oxidation 150) and carbon black powder (average particle diameter 80n)
m) was immersed in an aqueous solution dispersed at a solid content ratio of 1:10. Similarly to Example 1, a TiO ₂ electrode was used as a working electrode with respect to a saturated calomel electrode, and a mercury xenon lamp (manufactured by Yamashita Denso, light intensity 50 mW at a wavelength of 365 nm, from the back of the substrate was used while the working electrode was set at 1.6 V.
/ Cm ² ), the entire surface was irradiated with light for 10 seconds. As a result, a black electrodeposition film was formed in the region where the colored layer was not formed.
After washing the color filter, a protective layer was coated on the color filter. Thus, three primary color filters covered with the black matrix were produced. The transmittance of the obtained color filter was 80% or more, and the surface had high smoothness.

Example 3 A three-primary color filter (before forming a black matrix) prepared in the same manner as in Example 1 was washed with pure water, and then cured by ultraviolet light in which carbon black powder (average particle diameter: 80 nm) was dispersed. When the substrate was brought into contact with the resin solution and irradiated with UV light from the back surface of the substrate, a black cured resin layer was formed in a region where the colored layer was not formed. After washing the color filter, a protective layer was coated on the color filter. Thus, three primary color filters covered with the black matrix were produced. The transmittance of the obtained color filter was 80% or more, and the surface had high smoothness.

Example 5 A substrate prepared in the same manner as in Example 1 was immersed in an aqueous solution containing an azo dye having a carboxyl group, and a substrate commonly used in the field of electrochemistry shown in FIG. It was installed in a polar arrangement. A TiO ₂ electrode is used as a working electrode with respect to the saturated calomel electrode. A mercury xenon lamp (Yamashita Denso, light intensity of 365 nm) is supplied from the back of the substrate while applying a voltage from a potentiostat so that the working electrode becomes 2.0 V. (50 mW / cm ² ) was irradiated with light through a photomask for 10 seconds. A red electrodeposited film was formed on the light irradiated portion of the TiO ₂ surface.

Next, the substrate on which the red electrodeposition film is formed is
Styrene-acrylic acid copolymer (molecular weight 13,000,
Hydrophobic group / (hydrophilic group + hydrophobic group) molar ratio 65%, oxidation 15
0) and Cathilon Pure Blue 5GH
Was immersed in an aqueous solution dispersed at a solid content weight ratio of 1: 1. Similarly, TiO for saturated calomel electrode
_{The two} electrodes are used as working electrodes, the working electrode is set to 2.0 V, and a mercury xenon lamp (Yamashita Denso,
When the light intensity 50 mW / cm ²⁾ with a wavelength of 365nm was rolled to irradiation for 10 seconds light photomask, TiO ₂
A blue electrodeposited film was formed on the light-irradiated portion on the surface.

Next, the substrate on which the red and blue electrodeposited films were formed was applied to a 0.01M ProJet Fast Y
yellow2 and 0.01M Cathilon Pur
It was immersed in an aqueous solution mixed with eBlue 5GH. Similarly, a TiO ₂ electrode was used as a working electrode for the saturated calomel electrode, and a mercury xenon lamp (Yamashita Denso, light intensity 50 mW / cm ^{2 at} a wavelength of 365 nm) was photographed from the back surface of the substrate by setting the working electrode to 2.0 V. 10 with mask
Irradiated for 2 seconds. A green electrodeposited film was formed on the light-irradiated portion of the TiO ₂ surface. Thus, a color filter layer of three primary colors having an R layer, a G layer, and a B layer was formed.

Next, after washing the color filter with pure water, a styrene-acrylic acid copolymer (molecular weight: 13,
000, molar ratio of hydrophobic group / (hydrophilic group + hydrophobic group) 65%,
Oxidation 150) and carbon black powder (average particle size 80
nm) was immersed in an aqueous solution dispersed at a solid content ratio of 1: 1. Similarly, a TiO ₂ electrode is used as a working electrode for the saturated calomel electrode, and
When the entire surface was irradiated with light from a back surface of the substrate with a mercury xenon lamp (Yamashita Denso Co., light intensity of 365 nm, light intensity 50 mW / cm ² ) for 10 seconds at 6 V, a black electrodeposited film was formed in a region where no colored layer was formed. Was. After washing the color filter, a protective layer was coated on the color filter. Thus, three primary color filters covered with the black matrix were produced. The transmittance of the obtained color filter was 80% or more, and the surface had high smoothness.

Comparative Example A 125 μm-thick PET film with ITO (manufactured by Tokyo Oike Kogyo Co., Ltd.) was washed with water, and a low-temperature curing type titanium oxide dispersion (manufactured by Nippon Soda) in which titanium oxide having high optical activity was dispersed.
Is applied on a film with ITO by a dip coating method. Next, when this film was heated at 60 degrees for 30 minutes, the coating film of titanium oxide was peeled off on both surfaces. From this, it was found that when the conductive film was subjected to the ion treatment, the adhesiveness with the titanium oxide thin film was improved.

[0050]

According to the color filter manufacturing method of the present invention, a high-resolution flexible color filter having high transmittance and high smoothness can be manufactured without using photolithography technology. Especially,
A flexible color filter having a complicated pattern of pixel arrangement that cannot be handled by the conventional electrodeposition method can be manufactured. Also, a black matrix can be easily produced without using photolithography technology. Furthermore, the color filter of the present invention has high resolution,
Since it is lightweight and has flexibility in shape, it is highly versatile.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the conductivity of an aqueous liquid and the amount of electrodeposition.

FIG. 2 (A) is a case of Schottky junction, (B) is p
It is the schematic which shows the energy band of the semiconductor in the case of an in junction.

FIG. 3 is a schematic view of a substrate in which a current-carrying path is provided in a light-transmitting conductive film.

FIG. 4 is a schematic view showing one embodiment of a method for producing a color filter of the present invention.

FIG. 5 is a schematic view showing a means for supplying a current or the like used in forming a colored electrodeposition film of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 color filter substrate 2 light-transmitting plastic film 3 light-transmitting conductive film 4 optical semiconductor thin film 5 colored electrodeposition layer 6 colored electrodeposition layer 7 colored electrodeposition layer 8 black matrix 9 protective layer 10 aqueous liquid 11 counter electrode 12 potentio Stat 13 Shiohashi 14 Calomel electrode

Claims (19)

[Claims] 1. A substrate in which a light-transmitting plastic film, a light-transmitting conductive film, and an optical semiconductor thin film are sequentially laminated, and the substrate is immersed in an aqueous liquid containing a coloring electrodeposition material. A method for producing a color filter, comprising the steps of applying a current or a voltage to a film, irradiating a substrate with light, and forming a colored electrodeposition film made of a colored electrodeposition material on a light irradiated portion. 2. The method according to claim 1, wherein the color electrodeposition material is a material whose solubility changes in response to a change in pH, and which applies a current or an electric field to the light-transmitting conductive film and irradiates the substrate with light in accordance with an image pattern. P of the aqueous liquid near the light irradiation part
2. The method according to claim 1, wherein H is changed, and a color electrodeposition film made of the color electrodeposition material is formed on the light irradiation portion by changing the solubility of the color electrodeposition material corresponding to the change in pH. Manufacturing method of color filter. 3. The method according to claim 1, wherein a current or a voltage is applied so that a pn junction or a pin junction of the optical semiconductor thin film or a Schottky junction between the optical semiconductor thin film and the aqueous liquid interface has a reverse bias. A method for manufacturing a color filter according to claim 2. 4. The optical semiconductor thin film is an n-type optical semiconductor thin film, the coloring material contains a compound having a carboxyl group, and a current or a voltage is applied so that the light transmitting conductive film has a positive potential. The method for producing a color filter according to any one of claims 1 to 3, wherein 5. The optical semiconductor thin film is a p-type optical semiconductor thin film, the coloring material contains a compound having an amino group or an imino group, and a current or a voltage is applied so that the light transmitting conductive film has a negative potential. The method for producing a color filter according to any one of claims 1 to 3, wherein: 6. The method according to claim 1, wherein a current or a voltage is applied so that the potential difference of the optical semiconductor thin film at the time of forming the colored electrodeposition film is 5 V or less in absolute value. 2. The method for producing a color filter according to claim 1. 7. One of claims 1 to 6
After forming a colored electrodeposition film of a plurality of colors by the method described in the paragraph, the substrate is immersed in an aqueous liquid containing a black electrodeposition material, and a current or a voltage is applied to the light-transmitting conductive film, and the color electrodeposition is performed. A method for producing a color filter, comprising forming a black matrix made of a black electrodeposition material in a region where a film is not formed. 8. Any one of claims 1 to 6
After forming a colored electrodeposition film of a plurality of colors by the method described in the section, the substrate is immersed in an aqueous liquid containing a black electrodeposition material, and a current or voltage is applied to the light-transmitting conductive film and the entire surface of the substrate is exposed. A method for producing a color filter, comprising irradiating light to form a black matrix made of a black electrodeposition material in a region where a colored electrodeposition layer is not formed. 9. An optical semiconductor thin film obtained by subjecting a laminate of a light-transmitting plastic film and a light-transmitting conductive film to ion treatment, and then applying a dispersion of titanium oxide particles on the transparent conductive film and drying. The method according to claim 1, wherein the substrate is used as a substrate after forming the color filter. 10. The method for producing a color filter according to claim 9, wherein titanium oxide fine particles heated and reduced in a hydrogen atmosphere are used. 11. A color filter in which a light-transmitting plastic film, a light-transmitting conductive film, an optical semiconductor thin film, and a coloring layer are sequentially laminated. 12. The color filter according to claim 11, wherein a black matrix is formed in a region where the coloring layer is not formed. 13. The optical semiconductor thin film is formed from an n-type optical semiconductor.
3. The color filter according to any one of 2. 14. The color filter according to claim 13, wherein the n-type optical semiconductor thin film is formed from an oxide semiconductor. 15. The color filter according to claim 14, wherein the oxide semiconductor is titanium oxide. 16. The colored layer contains a compound having a carboxyl group.
5. The color filter according to any one of the items up to 5. 17. The optical semiconductor thin film is formed of a p-type optical semiconductor.
3. The color filter according to any one of 2. 18. The color filter according to claim 17, wherein the coloring layer contains a compound having an amino group or an imino group. 19. The optical semiconductor thin film is a pn junction or pi junction.
19. The color filter according to claim 11, wherein the color filter is an optical semiconductor thin film having an n-junction.