JP3941261B2 - Image recording method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a monochromatic and multicolor image recording method that can form a high-resolution image easily using light irradiation.
[0002]
[Prior art]
Many office image recording techniques use liquid image forming materials. For example, silver salt technology, ink jet technology, and electrophotographic technology.
Among them, patents (Japanese Patent Laid-Open No. 7-181750, Japanese Patent Publication No. 7-54407) using an electrodeposition liquid in which a color material is dispersed in an insulating liquid to generate an electric double layer are insulated on a conductive substrate. Patents using an electrodeposition printing technique in which an adhesive pattern is provided as a printing plate [Method for forming a fine pattern (JP-A-4-9902)], [Electrodeposition offset printing method and printing plate (JP-A-6-293125)], etc. Patents utilizing electrodeposition of image forming materials have been filed.
Moreover, there is an electrolytic developing method as one of the similar conventional techniques, and these are shown in, for example, the Electrophotographic Society Research Conference Proceedings P32 (1971) and the Electrophotographic Society Research Conference Proceedings P24 (196.11). ing. The electrolytic development method causes reduction in zinc oxide by applying a voltage of 10 V or more and simultaneous exposure, and the generated electrons move to the dissolved dye precursor to be reduced, and the reduced zinc film surface is reduced. This is a method of forming an image by color development / precipitation, and is an image formation method utilizing reduction of a specific metal oxide, and the color hue is limited.
[0003]
The characteristics required for printing technology used in offices are 600DPI or higher / multi-level gradation color high image quality, plain paper printing, image robustness comparable to printing, high safety of printed matter and printing machines, disposal There is a demand for almost no objects and low running costs. On the other hand, in these conventional techniques, a technique that can completely satisfy them is not completed.
In order to achieve high image quality (1000 DPI level resolution / good color reproduction / multi-value gradation), the image structure has an image thickness of 2 microns or less, more preferably 1 micron due to the relationship between the color reproduction range and the sharpness of the image. The following thickness is preferred. As a result, the average shape diameter of the image forming material, which is an element that gives the image structure, needs to be a size of submicron or less. However, if the average shape diameter of the image forming material is 5 microns or less, there will be a problem with fluidity, so that the powder-based image forming material is practically difficult to use. On the other hand, liquid image forming materials are considered to be quite effective in this respect. In addition, in the image forming process of several micron order images, it is technically difficult to control the pixel shape with high accuracy in the micro area of the image forming material particles, and the molecular order dye aqueous solution that is the smallest minute particle in the electrodeposition material. The use of is considered to be one of the very effective methods from the viewpoint of a highly accurate color material control method.
[0004]
In particular, there is a color filter manufacturing method as an application range of this technology. Currently, color filter manufacturing methods include (1) dyeing method, (2) pigment dispersion method, (3) printing method, and (4) ink jet. The method (5) electrodeposition method is known.
(1) A dyeing method is a pattern in which a water-soluble polymer for dyeing is formed on a glass substrate, patterned into a desired shape through a photolithography process, and then immersed in a dyeing solution. This was repeated three times and R.P. G. B. This is a method for obtaining a color filter layer. The obtained filter has a high transmittance and abundant hue, and has a high degree of perfection in technology, so it has been widely used in color solid-state imaging devices (CCDs) at present, but it is inferior in light resistance due to the use of dyes. Due to the large number, the pigment dispersion method has recently been replaced for liquid crystal display elements (LCD).
(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 is repeated three times. G. B. The color filter layer is obtained. This manufacturing method has a high degree of completeness of the technology, but has a drawback 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. B. And then applying heat to cure the resin, thereby obtaining a color filter layer. This method is described in R.A. G. B. Photolithography is not required for forming the layer, but there is a problem in terms of resolution and film thickness uniformity.
[0005]
(4) In the ink jet method, a water-soluble polymer ink-receiving layer is formed on a substrate, subjected to hydrophilization / hydrophobization treatment, and then ink is sprayed onto the hydrophilized portion by the ink jet method. G. B. This is a method for obtaining a color filter layer by coating the layers separately. This method is also described in R.A. G. B. The layer formation does not require photolithography, but is inferior in terms of resolution. In addition, there is a high probability that ink droplets are scattered and mixed when sprayed on adjacent filter layers, and the positional accuracy is poor.
(5) The electrodeposition method is an electrodeposition coating in which an electrodeposition film is formed by applying a high voltage of about 70 V on a previously patterned transparent electrode in an electrolytic solution in which a pigment is dispersed in a water-soluble polymer. Was repeated three times and R.M. G. B. The color filter layer is obtained. This method has a drawback that it is necessary to pattern a transparent electrode in advance by photolithography and use it as an electrode for electrodeposition, and since the shape of the pattern is limited, it cannot be used for a TFT liquid crystal.
[0006]
In addition, the color filter is rarely used only in the color filter layer, and it is general to use a color filter pixel covered with a black matrix. Usually, photolithography is used to form the black matrix, which is one of the major causes of cost increase. Therefore, R.I. G. B. Considering the layer and the black matrix, there is currently no method for producing a color filter that has high resolution, high controllability, does not require a photolithography process, and has a small number of processes. For example, it is well known that a color filter occupies a large part of cost in a liquid crystal color display device or the like, but this is also due to the high yield and high cost in the manufacture of color filters.
[0007]
In view of these problems, the inventors previously provided a transparent electrode and a photocharge generation layer on a glass transparent substrate, and then formed an electrodeposition film of each color on the transparent electrode to produce an image or a color filter. However, the present invention further proposes an image recording method that can use the photocharge generation layer repeatedly and that is improved in cost.
[0008]
[Problems to be solved by the invention]
An object of the present invention is an image recording method with high resolution and high controllability applying photovoltaic power, realizing a configuration in which an image forming layer can be exposed from the surface, that is, the electrodeposition liquid surface direction, and generating photocharges An object of the present invention is to provide an image forming method having a high degree of freedom in selecting constituent materials such as materials, conductive layer materials, and support substrates.
A further object of the present invention is to prevent the influence of random scattering and irregular reflection of light on the electrodeposition liquid surface with respect to exposure from the electrodeposition liquid surface direction, and to improve the light energy efficiency and resolution of irradiated light. Another object is to provide an image recording method.
Another object of the present invention is to apply these image recording methods to a simple color filter manufacturing method that does not use photolithography and has a small number of steps.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present inventors have reviewed the electrodeposition technique itself from the fundamental point of view. And the physical property etc. were examined in detail about the molecule | numerator in which the solubility to water mentioned above changes a lot. The phase change of the dissolution, precipitation, or precipitation due to the change in the solubility of the molecule can be carried out by directly oxidizing or reducing the molecule electrochemically or changing the pH of the aqueous solution in which the molecule is dissolved. Hereinafter, these electrochemically phase-change materials are appropriately referred to as electrodeposition materials.
In the image recording method of the present invention, a conductive film is formed on a substrate, and a substrate on which an organic semiconductor film or an inorganic semiconductor film having a photovoltaic function is formed is prepared, and a predetermined interval is provided on the substrate. Leave Maintains uniformity of electrodeposition layer thickness and smoothness of electrodeposition layer surface means (Hereafter, abbreviated as “liquid thickness uniformity holding means”.) And an electrodeposition solution containing a liquid material and a color material and an electrodeposition material that is chemically dissolved or deposited / precipitated by a change in pH. Electrodeposition liquid layer To form Electrodeposition liquid layer The organic semiconductor film or the inorganic semiconductor film having a photovoltaic function disposed on the substrate is irradiated with light, and an electrodeposition film containing an electrodeposition material is selectively deposited on the portion where the electromotive force is generated by the irradiation light. And forming an image.
[0010]
Here, the main wavelength range of the irradiation light for image formation is the main absorption wavelength range of the electrodeposition liquid and the above Liquid thickness uniformity holding means It is preferable to have an optical spectral characteristic different from any of the main absorption wavelength regions.
In the image recording method of the present invention, it is also possible to record an image on a desired image holding material by transferring the image formed by depositing the electrodeposition film as described above to the image holding material.
[0011]
According to this method, light is irradiated from the electrodeposition liquid side in which the electrodeposition material is dissolved and dispersed in an aqueous liquid, and an electrodeposition film containing the electrodeposition material is generated on the substrate by the photovoltaic force. On this occasion, Maintaining uniform liquid thickness By disposing the means, it is possible to effectively prevent light scattering and variations in photovoltaic force due to disturbance of the liquid surface of the electrodeposition liquid and uneven thickness of the electrodeposition liquid layer, and high resolution can be achieved.
When the electrodeposition material used in the present invention is a colorless or light-colored polymer material, a coloring material such as a pigment is dispersed in the polymer, and the polymer is precipitated in a state containing the coloring material. A colored electrodeposition film in which the polymer and the polymer are mixed is formed. In the case where the electrodeposition material itself is a colored substance, a colored electrodeposition film is formed as it is. In that case, it is not necessary to add a color material in particular. The term “electrodepositing material that dissolves, precipitates, or settles” also includes an electrodeposition material made of a dye that itself becomes a coloring material. These electrodeposition films can be re-applied in an aqueous solution by applying a reverse voltage or immersing them in an aqueous solution having a high solubility (pH 10 to 13 for anionic electrodeposition materials and pH 1 to 4 for cationic electrodeposition materials). Can be eluted.
In the present invention, the “electrodeposition liquid” is a generic term for an aqueous solution or an aqueous dispersion in which all or part of an electrodeposition material (dye, pigment, polymer compound, etc.) is dissolved or dispersed in an aqueous medium. .
[0012]
When recording a monochromatic image using an electrodeposition solution, an electrodeposition solution containing an electrodeposition material is selectively deposited on the portion where the electromotive force is generated by the light irradiation, and the electrodeposition solution in an image forming region where an image is formed is formed. The effective thickness is preferably in the range of 50 μm to 7 mm.
In the image recording method of the present invention, a multicolor image can be formed by repeating the step of forming a plurality of single color images by changing the color tone of the color material. When performing image recording, the effective thickness of the electrodeposition liquid in the image forming area where a multicolor image is formed by selectively depositing an electrodeposition film containing an electrodeposition material on the portion where electromotive force is generated by light irradiation. Is preferably in the range of 0.1 mm to 15 mm.
When forming a background color portion in a multicolor image, for example, specifically, when forming a black matrix in a multicolor color filter, the background color is set using the electrodeposition film as the electrodeposition material. After forming a multicolor image by the above-described method and containing a colorable material that can be formed, it is energized while irradiating light on the entire surface of the substrate, and an electrodeposition film of a plurality of colors constituting the multicolor image is not yet formed. A background color portion by an electrodeposition film can be formed in the formation portion.
[0013]
Used in the present invention Maintaining uniform liquid thickness The image forming region by light irradiation in the means is composed of a material having a transmittance of 50% or more with respect to the main wavelength region of the irradiation light, and Maintaining uniform liquid thickness In a preferred embodiment, the means has an opening capable of holding or flowing the electrodeposition liquid.
here, Maintaining uniform liquid thickness The opening of the means is liquid thickness Uniformity retention Comprising a doctor blade for said, Maintaining uniform liquid thickness The electrodeposition liquid can flow between the means and the substrate; Maintaining uniform liquid thickness The surface roughness Ra of the part in contact with the electrodeposition liquid of the means is preferably 10 μm or less.
[0014]
As for the electrodeposition material, a semiconductor thin film formed on a substrate is an n-type semiconductor, a pn junction in which an n-type semiconductor and a p-type semiconductor are sequentially stacked, or a pin in which an n-type semiconductor, an i-type semiconductor, and a p-type semiconductor are sequentially stacked. In the case of a semiconductor having a junction, a compound having a carboxyl group in the molecule is used as the electrodeposition material, and the semiconductor thin film formed on the substrate is a p-type semiconductor, a p-type semiconductor and an n-type semiconductor in this order. In the case of a stacked pn junction or a semiconductor having a pin junction in which a p-type semiconductor, an i-type semiconductor, and an n-type semiconductor are sequentially stacked, a compound having an amino group or an imino group in the molecule is used as the electrodeposition material. It is preferable.
Such an electrodeposition material has both a hydrophobic group and a hydrophilic group in the molecule, and the number of hydrophobic groups of the monomer units constituting the polymer is in the range of 40% to 80% of the ratio of the total number of hydrophilic groups and hydrophobic groups. A copolymer having a property that 50% or more of the hydrophilic group portion can be reversibly changed from a hydrophilic group to a hydrophobic group by a change in pH, and an acid value of 30 to 600; It is characterized by containing.
Moreover, this electrodeposition material may contain a compound having both a unit that precipitates and settles by changing pH in the molecule and a colorant unit.
[0015]
The electrodeposition film formation requires a certain threshold voltage or higher, and the electrodeposition film is not necessarily formed when a current flows. Therefore, if a bias voltage is applied, an image can be formed even if the voltage level inputted from the outside is small. Therefore, an arbitrary electrodeposition film can be formed at a desired position by forming a transparent semiconductor layer on the substrate to be electrodeposited and using light for this input signal. Hereinafter, the electrodeposited film thus formed is referred to as a photo-deposited film.
Here, the electrodeposition material may form an electrodeposition film by the sum of the electromotive force due to light irradiation to the semiconductor layer and the bias voltage applied to the transparent electrode, but the bias voltage application depends on the photoelectromotive force. For example, the bias voltage applied to the transparent electrode can be omitted if the photovoltaic power of the semiconductor is sufficient to form the electrodeposition film.
[0016]
The outline of the image recording method proposed by the present inventors is that an organic or inorganic semiconductor is used as a substrate, and an electrodeposition material containing (or also serving as) a coloring material in an aqueous solution is irradiated on the semiconductor substrate by irradiating light. Since an image is formed by being deposited in the form of a dye electrodeposition film, a general-purpose patterned transparent conductive film is unnecessary in the conventional image recording method using the electrodeposition method, and any image can be obtained without a photolithography process. A pattern can be formed.
[0017]
The multicolor image according to the present invention includes an electrodeposition material while forming a semiconductor thin film on the electrode and applying a bias voltage to the electrode. Electrodeposition liquid layer By changing the pH in the vicinity of the substrate by irradiating light and generating photovoltaic power, the electrodeposition film using the difference in solubility depending on the pH of the polymer or dye molecule is selected as the light irradiation part It can be formed by forming a thin film and repeating this step a plurality of times. For example, full-color color image recording is achieved by repeating the coloring material three times as red (R), green (G), and blue (B).
[0018]
According to the image recording method of the present invention, a high-resolution photodeposition film can be formed by using a Schottky junction between a semiconductor thin film and an electrodeposition solution, or a pn junction or a pin junction of the semiconductor thin film itself. Moreover, since light irradiation is performed from the electrodeposition liquid side, the substrate and the semiconductor do not necessarily have to be transparent, so that there is an advantage that the range of selection of materials is widened.
[0019]
Furthermore, if the color image recording method of the present invention is applied, after forming a multicolor image, a voltage is applied in an electrodeposition liquid containing a background color forming material (at this time, there is no light). However, since the electrical resistance of the already formed multicolor image layer is high, the background color portion including the electrodeposition material is selectively formed only in the unformed portion of the image by adjusting the applied voltage. Thus, a background color portion can be easily formed in a multicolor image. If this is applied, for example, a black matrix can be easily formed on a color filter created by applying this image recording method on the same principle.
The background color portion such as a black matrix is not limited to the method of forming by electrodeposition, but can also be formed using an ultraviolet curable resin.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
First, a molecule (electrodeposition material) that changes its solubility due to a change in pH such as alkaline or acidic, or an electrochemical change, and dissolves, precipitates, or precipitates is required. The electrodeposition material may be a dye itself, or may have a property that a transparent polymer is precipitated in an alkaline or acidic manner, and a coloring material may be dispersed together with the polymer. When the coloring material is dispersed in a polymer, not only a dye but also a pigment can be used. In the case of image recording to be used in a site that requires high light resistance, it is desirable to use an aqueous polymer in which a pigment is dispersed.
[0021]
As a compound having such a property that causes a phase change of dissolution, precipitation, or precipitation due to a change in electrochemical conditions, for example, as a dye material, it is in a reduced state at pH 4 or more and dissolves in water, but is less than pH 4 In this region, rose bengal and eosin, which are fluorescein pigments that are oxidized to neutral state and precipitate, and carboxyl groups whose solubility varies greatly depending on the hydrogen ion concentration (pH) of the solution without structural change. And the like (specifically, water-resistant improved ink jet dyes, which are soluble in water at pH 6 or higher but precipitate at lower temperatures). Examples of the polymer material include a specific water-soluble acrylic resin that is a kind of polymer having a carboxyl group that is soluble in water at a pH of 6 or higher but precipitates at a pH lower than that. In addition, oxazine-based basic dye Cathilon Pure Blue, which is one of quinoneimine dyes.
5GH (CI Basic Blue 3) and thiazine-based basic dye methylene blue (CI Basic Blue 9) take an oxidized state when the pH is 10 or less, and develop a color. And precipitate. When these dyes are dissolved in pure water, an electrode is immersed in the solution and a voltage is applied, an electrodeposited film composed of these dye molecules is formed on the electrode on the cathode side. These dye electrodeposition films are restored to their original state and re-eluted into the aqueous solution by applying a reverse voltage or immersing them in an aqueous solution of pH 8 or lower.
[0022]
Hereinafter, these electrochemically phase-change materials are appropriately referred to as electrodeposition materials. When an electrodeposition material is dissolved in pure water, an electrode is immersed in the solution and a voltage is applied, an electrodeposition film made of these electrodeposition materials is produced on the electrode on the anode side. When the electrodeposition material is a colored substance, a colored electrodeposition film is formed as it is. When the electrodeposition material is a colorless or light-colored polymer material, a pigment is dispersed in the polymer and the electrode is immersed in the solution. When a voltage is applied, a pigment and a polymer are deposited on the anode-side electrode, and an electrodeposition film in which the pigment and the polymer are mixed is formed. These electrodeposition films can be re-applied in an aqueous solution by applying a reverse voltage or immersing them in an aqueous solution having a high solubility (pH 10 to 13 for anionic electrodeposition materials and pH 1 to 4 for cationic electrodeposition materials). Can be eluted.
The electrodeposition film formation requires a certain threshold voltage or higher, and the electrodeposition film is not necessarily formed when a current flows. Therefore, if a bias voltage is applied, an image can be formed even if the voltage level inputted from the outside is small. Therefore, if a semiconductor is used for the substrate to be electrodeposited and light is used for this input signal, an arbitrary electrodeposition film can be formed at a desired position. Hereinafter, the electrodeposited film thus formed is referred to as a photo-deposited film.
[0023]
As an example of a compound capable of forming such a photo-deposited film, an explanation will be given by taking, as an example, Pro Jet First Yellow 2 manufactured by Zeneca Co., Ltd., which is an acid dye and the dye itself has an electrodeposition-forming ability. This dye is easily dissolved in pure water (pH 6 to 8), and exists in an aqueous solution as an anion, but has a property of being insolubilized and precipitated when the pH is 6 or less. When the platinum electrode is immersed in the aqueous solution of Pro Jet first Yellow 2 and energized, the OH in the aqueous solution is near the anode. ^- Ion is consumed and O ₂ The hydrogen ions increase and the pH decreases. This is because the hole (p) and OH are near the anode. ^- This is because the following reaction occurs in association with ions.
2OH ^- + 2p ⁺ → 1/2 (O ₂ ) + H ₂ O
In order for this reaction to occur, a certain voltage is required, and as the reaction proceeds, the hydrogen ion concentration in the aqueous solution increases and the pH decreases. Therefore, when a voltage higher than a certain level is applied, the solubility of Pro Jet first Yellow 2 is lowered on the anode side of the electrode, so that it becomes insoluble and a thin film is formed.
[0024]
The present invention utilizes the photovoltaic force generated by irradiating a semiconductor with light to obtain this constant threshold voltage. Various attempts have been made to use such photovoltaic power. For example, A.I. Fujishima, K .; Honda Nature Vol. 238, p37, (1972), n-type semiconductor TiO ₂ The water was electrolyzed with water. In addition, in connection with research on photoelectrochromism, an example in which light is irradiated onto a Si substrate, pyrrole is electrochemically polymerized, and image formation is performed by doping and dedoping is described in H.C. By Yoneyama et al. Electrochem. Soc. , P2414, (1985). The present inventors also filed a patent application for a method of forming an image with light using a dye for doping and dedoping of a conductive polymer.
[0025]
On the other hand, it is possible to form an electrodeposition film only with a dye without using a conductive polymer, but the voltage required for forming the electrodeposition film is larger than when a conductive polymer is used. On the other hand, the photovoltaic power is 0.6 V at most, and the photovoltaic power alone is not sufficient for image formation. Therefore, a method such as raising the bias voltage by applying a bias voltage can be considered. However, if the voltage is still higher than a certain voltage (voltage depending on the band gap of the semiconductor to be used), the semiconductor and the solution required for forming the photovoltaic power There is a problem that the Schottky barrier between them is broken, and there is a limit to the bias voltage that can be applied. For this reason, image formation in an aqueous solution using the redox of a substance using photovoltaic power is limited to one using a photopolymerization reaction of a conductive polymer such as polypyrrole that is oxidized and reduced at 1.0 V or less. It was.
However, since the present inventors use the difference in solubility of molecules according to pH for image formation, it is possible to form a colored polymer layer at a low voltage. Electrodeposition by photovoltaic using various semiconductors. A colored image can be formed by the film.
[0026]
Among such electrodeposition materials, colorless or light-colored polymer compounds specifically include a monomer unit having a hydrophilic group capable of ion dissociation and a minimum having a hydrophobic group that promotes insolubilization in an aqueous electrodeposition solution. The number of hydrophobic groups in the monomer unit of the copolymer polymer is comprised in the range of 40% to 80% of the total number of hydrophilic groups and hydrophobic groups, more preferably 55%. To 70% is particularly preferable because it has a high electrodeposition deposition efficiency, shows electrodeposition characteristics that can form a film at a low electrodeposition potential, and the liquidity of the electrodeposition liquid is also stable. In addition, 30% or more, more preferably 65% or more, of the monomer unit hydrophilic group part of this electrodeposition material contains a monomer unit hydrophilic group part that can be reversibly changed from a hydrophilic group to a hydrophobic group by a change in pH. It is preferable that the electrodeposition material is constituted.
If the number of hydrophobic groups in the monomer unit of the electrodeposition material is less than 40% of the ratio of the total number of hydrophilic groups and hydrophobic groups, the electrodeposition film formed at the time of electrodeposition has insufficient water resistance and film strength. When the ratio of the number of hydrophobic groups in the monomer unit of the material is more than 80% of the total number of hydrophilic groups and hydrophobic groups, the solubility in aqueous liquids becomes insufficient, the electrodeposition liquid becomes cloudy, or the electrodeposition material precipitates Is generated, and the viscosity of the electrodeposition liquid is increased. The number of hydrophilic groups and hydrophobic groups can be calculated based on, for example, the charging ratio of monomers at the time of polymer polymerization reaction in the case of vinyl polymers and the like.
[0027]
The hydrophobic group in the structure of the electrodeposition material has a strong affinity for the organic pigment used in combination as a coloring material, has an adsorption ability for the pigment, and imparts a good pigment dispersion function. Further, a printing function for instantly depositing an image is imparted to the hydrophilic detachment of the hydrophilic group portion of the electrodeposition material due to a change in pH due to application of voltage. In particular, when the number of hydrophobic groups in the monomer unit of the electrodeposition material is in the range of 40% to 80% of the total number of hydrophilic groups and hydrophobic groups, the effect of reducing the electrodeposition potential for forming a strong film is great. Therefore, it is an indispensable condition for completing a low-potential printing process using photovoltaic power generated by light input.
[0028]
As a type of electrodeposition material that deposits on the positive electrode, it is preferable to use a copolymer having an acid value of 30 to 300 from the viewpoints of precipitation and retention of the formed electrodeposition film. Better electrodeposition characteristics can be obtained by using a copolymer having a 90-195. If the acid value of the electrodeposition material is less than 30, the solubility in an aqueous medium is insufficient, and it is difficult to increase the solid content concentration of the electrodeposition solution to an appropriate value. Inferior in water resistance and electrodeposition efficiency may be lowered, both of which are not preferred.
[0029]
In particular, those in which the ion-dissociating hydrophilic group is a carboxyl group or an amino group exhibits good image deposition efficiency and high fastness in electrodeposition in the electrodeposition phenomenon. These two groups have high efficiency in reversibly changing from a hydrophilic group to a hydrophobic group due to a change in pH, and these characteristics can be obtained.
[0030]
Further, the electrodeposition material has a structure containing a thermoplastic resin component, and must exhibit sufficient solubility in the adjusted aqueous liquid. Further, it is required that a liquid property change that generates a supernatant from the dissolved state of the electrodeposition material to cause precipitation in the pH range region 1 with respect to a change in the pH value of the electrodeposition solution in which the electrodeposition material is dissolved. .
In order to obtain more preferable characteristics, the pH range is required to be within 0.5. Due to the characteristics within this range, it is possible to instantly deposit an image even when there is a sharp pH change due to energization, and to add a function to increase the cohesive force of the deposited image and reduce the re-dissolution rate in the electrodeposition solution. It is possible. Thereby, the water resistance of the image is also obtained. When the pH range of the liquid property change that causes precipitation from the dissolved state with respect to the change in pH value of the electrodeposition solution is greater than 1, the print speed is decreased to obtain a sufficient image structure and the image is not water resistant. This leaves problems with the printing characteristics.
[0031]
Monomer units containing hydrophilic groups used in this electrodeposition material include methacrylic acid, acrylic acid, hydroxyethyl methacrylate, acrylamide, maleic anhydride, trimellitic anhydride, phthalic anhydride, hemimerlic acid, succinic acid, adipine Acid, propiolic acid, propionic acid, fumaric acid, itaconic acid, etc. and their derivatives are used. In particular, methacrylic acid and acrylic acid are useful hydrophilic monomer structural units having a large effect / effect on the electrodeposition phenomenon, high electrodeposition efficiency due to pH change, and high hydrophilization efficiency.
[0032]
Monomer units containing hydrophobic groups used in this electrodeposition material include alkyl groups, styrene groups, α-methylstyrene groups, α-ethylstyrene groups, methyl methacrylate groups, ethyl methacrylate groups, butyl methacrylate groups, Examples include acrylonitrile group, vinyl acetate group, methyl acrylate group, ethyl acrylate group, butyl acrylate group, lauryl methacrylate group, and derivatives thereof. In particular, styrene groups and α-methyl-styrene groups are hydrophobic monomer structural units of electrodeposition materials that have high hydrophobizing efficiency, good electrodeposition efficiency, and high controllability during production polymerization.
[0033]
These are high-molecular substances obtained by copolymerizing molecules containing a hydrophilic group and a hydrophobic group at the above ratio, and the type of each hydrophilic group and hydrophobic group is not limited to one. From the viewpoint of electrodeposited film properties and adhesion strength of the film, an electrodeposited film having an average molecular weight of 6,000 to 25,000 can be obtained. From the viewpoint of more preferable film properties and adhesive strength of the film, an electrodeposition film having an average molecular weight of 9,000 to 20,000 can be obtained. When the average molecular weight is lower than 6,000, the film is not uniform and the water resistance is low. For this reason, a highly robust electrodeposition film cannot be obtained, and the film property is low, and cracks frequently occur or powdered. On the other hand, if the average molecular weight is higher than 25,000, the solubility in the aqueous liquid becomes insufficient, and the solid content concentration of the electrodeposition liquid cannot be increased to an appropriate value, or the liquid becomes cloudy or precipitates are formed. The liquid viscosity increases, causing problems. The thermal characteristics of these materials are as follows: a transfer process using heat by using a material having a glass transition point lower than 80 ° C., a flow starting point lower than 200 ° C., and a decomposition point higher than 100 ° C. The control margin is widened, and good transfer characteristics of the electrodeposition film can be obtained.
In combination with a pigment, a transparent polymer material with electrodeposition, for example, a water-soluble acrylic resin, combined with a water-soluble acrylic resin and dispersed in an aqueous solution can be used to obtain a pigment as an electrodeposition film.
[0034]
Next, the conductivity and pH of the solution will be described. According to our experiment, the conductivity is related to the amount of electrodeposition, in other words, the higher the conductivity, the thicker the electrodeposition film deposited in a certain time, the more about 100 mS / cm. ² Saturates at. (See FIG. 1) Accordingly, when the conductivity is insufficient with only the dye ions, an acidic or alkaline substance that does not affect the electrodeposition characteristics, such as Na ⁺ Ion and Cl ^- By adding ions, the electrodeposition speed can be controlled. For example, an electrodeposition film can be formed by applying a voltage of 5 V or less.
In addition, the pH of the aqueous solution naturally affects the formation of the electrodeposition film. For example, if the electrodeposition film is formed under the condition that the solubility of the dye molecule is saturated before the electrodeposition film is formed, it is difficult to redissolve after the film formation. However, when the electrodeposition film is formed at the pH of the unsaturated solution, the film begins to redissolve as soon as the current supply is stopped even if the electrodeposition film is formed. Therefore, it is desirable to form the electrodeposition film at a pH of the solution that saturates the solubility.
[0035]
Next, the substrate used in the image recording method of the present invention will be described. In the present invention, since the photoelectromotive force by light irradiated on the electrodeposition material side is used for image recording, the substrate is not necessarily transparent unlike the conventional electrodeposition method. Accordingly, the substrate is a substrate that can be suitably used as a semiconductor substrate provided on the substrate, and any substrate can be used as long as the surface is smooth. Of these, glass substrates, metal substrates such as aluminium, and conductive ceramic substrates are preferable. First, a conductive layer is formed on the substrate. Any known conductive layer can be used, for example, a general-purpose ITO film, Au film, Pt film, Al film, Cr film, etc. What is necessary is just to form.
[0036]
An organic or inorganic semiconductor layer is formed on the conductive layer. As the semiconductor layer, a photovoltaic semiconductor having almost no light history effect is preferable. Basically, any semiconductor thin film that generates an electromotive force by light irradiation and does not have a strong light history effect can be used. Specifically, as photovoltaic semiconductor materials, Si, GaN, a-C, BN, SiC, Zn, Se, TiO ₂ , GaAs compounds, Cu, Zn P ₂ Phthalocyanine pigment-based materials, perylene pigment-based materials, azo pigment-based materials, various organic photoconductive materials, and the like can be used. The semiconductor layer may be a single layer or a plurality of layers, and a mixture of the semiconductor materials may be used. It can be used.
[0037]
As this semiconductor layer, titanium oxide is particularly suitable. This titanium oxide has an absorption in the region of 400 nm or less, is transparent, and can be used as it is as a substrate. In recent years, titanium oxide having good characteristics as an n-type semiconductor has been obtained by various methods such as a sol-gel method, a sputtering method, and an electron beam evaporation method.
TiO which is a suitable transparent semiconductor here ₂ Is described. TiO ₂ Is a transparent oxide semiconductor that generates a photovoltaic force when irradiated with ultraviolet rays. Therefore, if an ultraviolet ray is applied from the back of the substrate, a photo-deposited film can be formed on the transparent substrate. TiO ₂ There are several known methods for forming the film. For example, a thermal oxide film method, a sputtering method, an electron beam method (EB method), a sol-gel method, and the like are well known. We use EB method and sol-gel method for TiO ₂ The film was formed. However, the ordinary film forming method is inefficient and the photocurrent necessary for electrodeposition does not flow. Therefore, reduction treatment was performed to increase the conversion efficiency of photocurrent. The reduction treatment is usually performed in hydrogen gas at about 550 degrees. For example, Y. Hamasaki et al. Electrochem. Soc. Vol. 141, No3. In p660 and 1994, heating is performed in hydrogen gas at about 550 degrees for about 1 hour. However, we have obtained a sufficient effect with a low temperature and short time treatment of about 360 ° C. for 10 minutes. This was achieved by heating with a flow rate of 1 liter per minute using 3% hydrogen mixed nitrogen gas.
[0038]
These semiconductor layers may be provided with a protective layer on the surface. The thickness of the semiconductor layer is in the range of 0.05 μm to 1.9 μm, which is a usable range where good characteristics can be obtained. If the layer thickness is less than 0.05 μm, the obtained optical power is too weak, which may cause a problem in good image formation. If the layer thickness exceeds 1.9 μm, the charge generated by light is trapped in the layer, and the photohistory phenomenon Becomes too large and causes problems in image formation. In addition, in consideration of the power generation efficiency by light, these semiconductor films are composed of a single semiconductor, such as a resin, in order to easily obtain the power necessary for film deposition by the electrodeposition method. Mixing and inclusion of insulating materials must be avoided. Furthermore, the mixing and inclusion of an insulating material such as a resin in the semiconductor layer also causes a large light history phenomenon.
The semiconductor includes an n-type semiconductor and a p-type semiconductor, but any semiconductor can be used in the present invention. Furthermore, if a laminated structure using a pn junction or a pin junction is used, it is more desirable because a photocurrent flows well and an electromotive force can be obtained with certainty and the contrast is improved.
[0039]
Next, a combination of a semiconductor and a material capable of forming an electrodeposition film is determined by the polarity of the semiconductor used. As is well known as a solar cell, the photovoltaic power is formed using a Schottky barrier, a pn or pin junction generated at the interface in contact with the semiconductor. As an example, an n-type semiconductor will be described with reference to the schematic diagram of FIG. The schematic diagram of FIG. 2A shows the case of the Schottky junction, and the schematic diagram of FIG. 2B shows the case of the PIN junction. When there is a Schottky barrier between the n-type semiconductor and the solution, if the semiconductor side is negative, the current flows in the forward direction, but conversely, when the semiconductor side is positive, no current flows. However, even when the semiconductor side is positive and no current flows, electron-hole pairs are generated when light is irradiated, and the holes move to the solution side and current flows. In this case, since the semiconductor electrode is made positive, the electrodeposited material must be negative ions. Therefore, it becomes a combination of an n-type semiconductor and an anionic molecule, and conversely, cations are electrodeposited in a p-type semiconductor.
[0040]
In general, the photovoltaic power of a semiconductor can be obtained at most 0.6V even with relatively large Si. However, materials that can be electrodeposited at 0.6 V are limited. Therefore, it is necessary to compensate for the insufficient voltage by applying a bias voltage. The upper limit of the bias voltage that can be applied is up to the limit at which the Schottky barrier is maintained. When the Schottky barrier is broken, a current also flows in a region where no light is applied, and an electrodeposition film is formed on the entire region of the semiconductor substrate, so that image formation cannot be performed. For example, in the case of a material that is electrodeposited at 2.0 V, when a bias voltage of 1.5 V is applied and light is applied, the threshold value necessary for electrodeposition is obtained by adding 0.6 V of the semiconductor photovoltaic power to 2.1 V. A photo-deposited film is formed only in the region where the voltage is exceeded and the light is irradiated.
The mechanism used here is a photovoltaic mechanism that is different from an external photocurrent effect mechanism in which the conductivity is simply increased by light irradiation and the energization current is increased by the applied voltage of the bias.
[0041]
As a guideline for selecting a substance (electrodeposition material) capable of forming this electrodeposition film, the dissolution characteristics accompanying the change in pH of the electrodeposition material are shown in the graph of FIG. FIG. 3 is a graph showing the relationship between the solubility characteristics of various materials and the pH of the solution. Some materials, such as graph A (shown by a solid line), suddenly precipitate at a certain pH value, and the solubility is good regardless of the pH value, as in the material of graph B (shown by a broken line). Some materials, such as the material of graph C (indicated by a dashed line), are insoluble regardless of the pH value, and these characteristics also change depending on the relationship between the material and the solvent (dispersion medium) used. In the present invention, as shown in graph A, it is preferable that precipitation occurs abruptly at a certain pH value. Also, as this graph A shows a so-called hysteresis curve, re-dissolution with respect to the change in pH value. It is ideal from the viewpoint of the stability of the formed image that the image is not abruptly performed and is kept in a deposited state for a certain period of time. Therefore, it is preferable to select a combination of an electrodeposition material having such characteristics and a solvent.
[0042]
As the electrodeposition material, two kinds of ions can be mixed and used. Consider the case where two types of ions are used in combination. In general, when a basic solution and an acidic solution are mixed, they are neutralized to form another precipitate such as a complex and precipitate. For this reason, when two types of dyes are mixed to produce a mixed color, a nonpolar pigment is generally used or a material having the same polarity is dispersed. However, with certain types of dyes, a complex is not formed but ions coexist. In this case, even if a basic solution and an acidic solution are mixed, precipitates can be suppressed, and a combination of ions having different polarities can also be used. We considered the case where two kinds of dye ions were mixed using this property.
[0043]
First of all, two kinds of ions having the same polarity, for example, an anionic and rose bengal (red) that has the ability to form an electrodeposited film are mixed with the same anionic but brilliant blue (blue) that has no ability to form an electrodeposited film. When electrochemically oxidized in the mixed solution, a purple electrodeposition film having the same color as the mixed solution is formed on the electrode. This is because brilliant blue ions are taken into Rose Bengal, which has the ability to form an electrodeposition film, to form a film. Thus, when two types of ions having the same polarity are mixed, it is sufficient that any one type of ions has an electrodeposition film forming ability.
[0044]
Next, a mixture of two types of ions with different polarities, such as Pro Jet First Yellow 2 (yellow), which is anionic and capable of forming an electrodeposited film, and Catiron Pure Blue 5GH (blue), which is cationic and capable of forming an electrodeposited film When electrochemically oxidized in the solution, a green electrodeposition film having the same color as the mixed solution is formed on the electrode. Conversely, when electrochemically reduced, a blue electrodeposited film of Cathilon Pure Blue 5GH alone is formed on the electrode. To explain the characteristics of such an ionic compound, for example, as shown in the graph of FIG. 4, one compound is dissolved in the solvent in the neutral region as shown in the graph A (shown by a solid line). Precipitation occurs abruptly at a certain low pH value, and the other compound has a characteristic that it dissolves in a solvent in a neutral region like the material of graph B (shown by a broken line), and abrupt precipitation occurs at a high pH value. In this case, high solubility is maintained in the neutral region, and phase change of dissolution and precipitation occurs at a specific pH value. In such a case, when an electrochemical reaction is performed in a mixed solution of an anionic dye solution and a cationic dye solution, only the polarity of the applied voltage is changed, so that different dyes can be formed on the same electrode. An electrodeposition film can be formed.
[0045]
Next, when using a pigment as a coloring material, it may be used in combination with an electrodepositable transparent or light-colored polymer material such as a water-soluble acrylic resin or a water-soluble styrene resin and dispersed in an aqueous solution. Thus, when the electrodeposition material forms an electrodeposition film, a colored electrodeposition film containing a pigment is obtained.
[0046]
The image recording method of the present invention will be described with reference to FIG. First, the conductive film 14 is formed on the substrate 12 as described above (FIG. 5A), and the substrate 18 (FIG. 5B) on which the semiconductor thin film 16 is formed is prepared.
Next, using an apparatus as shown in FIG. 6, an electrodeposition solution containing a coloring material and an electrodeposition material that is chemically dissolved, precipitated, or settled by a change in pH on the substrate 18 having the above-described configuration. An electrodeposition liquid layer 22 is provided, and a substrate 18 in which means 24 capable of supplying an electric current or an electric field according to an image pattern is connected to the conductive film 14 is disposed so that the semiconductor thin film (electrode) 16 is in contact with the electrodeposition liquid layer 22. At this time, they are arranged on the substrate 18 at a predetermined interval. Maintaining uniform liquid thickness The thickness of the electrodeposition liquid layer 22 is made uniform by the means 26, and the liquid level is kept smooth. In this aspect, Maintaining uniform liquid thickness The transparent electrode layer formed on the surface of the means 26 functions as the counter electrode 40, and the TiO ₂ Electrode 16 is used as a working electrode.
[0047]
When a predetermined mask pattern 28 is disposed on the electrodeposition liquid layer 22 of the substrate 18 and light irradiation is performed through the predetermined optical system 29 by the exposure light source 27, the portion where electromotive force is generated by the light irradiation is selectively selected. Then, a colored electrodeposition film 30 containing an electrodeposition material and a color material is deposited, and this becomes a colored electrodeposition film layer for recording a monochrome image. The colored layer 30 is fixed by removing the electrodeposition liquid 22 from the substrate 18 on which the colored electrodeposition film is formed. Here, the portion where the mask pattern 28 is arranged and the electromotive force is generated is determined. However, the electromotive force generated by light irradiation is generated in a predetermined portion by writing directly with the laser beam without using the mask pattern 28. It can also be made.
[0048]
At this time, by changing the color tone of the color material to, for example, red (R), green (G), and blue (B) and repeating this step (step of recording a monochromatic image), the electrodeposition liquid layer 22 and the mask A multicolor image can be easily formed only by performing the same process by changing the pattern 28 (FIG. 5C). Further, as described later, a background color portion layer 32 such as a black matrix is formed to obtain a multicolor image having a background color on the substrate 18 (FIG. 5D). The multicolor image thus obtained can be transferred in close contact with a suitable support 40 under heating and pressure conditions (FIG. 5E) to form a recorded image transferred onto the desired support 40. (FIG. 5F).
[0049]
The saturated calomel electrode potentials are 0.2444 V, 0.2412 V, and 0.23878 V at 20 ° C., 25 ° C., and 30 ° C., respectively, and are substantially equal to the ground potential = 0V. In forming an image, the saturated calomel electrode is not used, and the container (electrolytic solution) can be connected to the ground. However, in order to clarify the potential of the work electrode (deposition side electrode), as described above. Alternatively, the electrolytic solution may be connected to a saturated calomel electrode, and the potential on the surface of the electrolytic solution may be set to the standard potential of the saturated calomel electrode.
[0050]
Used in the image recording method of the present invention Maintaining uniform liquid thickness The means 26 is provided for the purpose of maintaining the uniformity of the thickness of the electrodeposition liquid layer 22 formed on the substrate and the smoothness of the liquid layer surface. FIG. 7 (A) Maintaining uniform liquid thickness It is a top view which shows the one aspect | mode of the means 26, (B) is the doctor blade 36 formed Maintaining uniform liquid thickness FIG. 8 is a schematic side cross-sectional view showing an embodiment of the means 26, and FIG. 8A shows a gap forming portion 34 formed therein. Maintaining uniform liquid thickness FIG. 5 is a schematic front cross-sectional view showing one embodiment of the means 26, and FIG. In the opening for introducing the electrodeposition liquid, a doctor blade 36 for smoothing the liquid level or a gap forming part 34 for smoothing the transparent sheet-like transparent exposure part 38 for regulating the liquid level. The electrodeposition liquid layer 22 is entirely covered with a transparent sheet-like transparent exposure part 38 at a distance from the liquid surface by a predetermined gap forming part 34. At both ends of the gap forming portion 34, holding portions 34a for stably holding the gap forming portion 34 against the surface of the electrodeposition liquid layer 22 are formed.
The doctor blade 36 is preferably disposed from the viewpoint of maintaining the gap at the end portion with higher accuracy. Further, from the viewpoint of the smoothness of the liquid surface, the doctor blade 36 has a surface roughness at a portion in contact with the electrodeposition liquid. Ra is preferably 10 μm or less. Further, it is preferable that the transparent exposure portion 38, that is, the image forming region by light irradiation is made of a material having a transparency of 50% or more with respect to the main wavelength region of the irradiation light. The electrodeposition liquid for forming the electrodeposition liquid layer 22 may be a held liquid layer in a stationary state, or may form a liquid layer with a constant thickness while flowing.
[0051]
Next, an exposure apparatus for producing a photo-deposited film will be described. In the present invention, since it is necessary to perform exposure from the electrodeposition liquid layer side of the substrate surface through a mask pattern, the exposure light source must have a wavelength with little absorption of the electrodeposition liquid. Then, it is necessary to perform exposure with a light source of an ultraviolet light region or an infrared light region of 400 nm or less or 700 nm or more. Usually, a mercury lamp, a mercury xenon lamp, a He—Cd laser, N ₂ Lasers, excimer lasers, semiconductor lasers and the like are preferably used.
[0052]
Next, a method for forming a background color portion such as a black matrix will be described. For the formation of the black matrix, a conventionally known general method is a method in which the black filter is formed in the same manner as the color filter layer using photolithography, or a black matrix is formed only in a portion without the color filter layer using an ultraviolet curable resin. Although there are methods, various measures are necessary to completely shield the screen, which is a major factor in increasing the cost of the color filter. However, when the color filter layer is formed using our photo-deposition method, the semiconductor is exposed in the unformed region of the photo-deposition film, and an electrodeposition film for the black matrix is easily formed in this area. it can. Furthermore, since the generally formed electrodeposition film is an organic thin film and has high insulation, it is rather difficult to form a further photodeposition film on the formed color filter layer. Therefore, after forming the color filter layer using the photo-deposition method, if voltage is applied in the electrolytic solution for the black matrix (there is no need for exposure because there is no need for light at this time) A black matrix electrodeposition film is formed so as to completely fill the unformed region of the color filter layer. As described above, by using the photo-deposited film, a black matrix can be formed easily and at low cost. In addition, even when an ultraviolet curable resin is used due to the same action, the electrodeposition film is formed cleanly in the unformed region of the color filter layer. Therefore, an ultraviolet curable resin may be used instead of forming the electrodeposition film. However, when a color filter layer is formed using a highly conductive electrodeposition material, it is possible to further stack an electrodeposition film, which is useful when forming color filter layers with different functions. However, when the black matrix is formed by the method described above, it is necessary to pay attention to conditions such as applied voltage.
[0053]
Thus, a protective layer can be provided on the color filter layer and the black matrix thus formed to improve smoothness and durability. The protective layer can be formed by a conventional method using a resin material such as an acrylic resin, a polyimide resin, or a polyester resin.
[0054]
Since the image recording method as described above irradiates the photovoltaic generation layer with the optical image signal through the electrodeposition liquid, the light irradiation efficiency at this time (surface irradiation energy / light source emission in the photovoltaic generation layer) It is necessary to devise a method to minimize the decrease in energy. The light irradiation efficiency is required to be 30% or more, preferably 50%.
[0055]
In particular, the electrodeposition liquid for forming a color image is performed by using an optical image signal input in an invisible region that is less influenced by the formed image because the characteristics relating to light reflection and light absorption of the image are determined by the requirements of the visible light region. Alternatively, it is necessary to use an optical image signal input in a wavelength region other than the large light absorption characteristic region.
In order to keep the light irradiation efficiency constantly high, the effective thickness of the electrodeposition liquid is preferably set in a thickness range of 50 μm to 7 mm, and more preferably in a range of 100 μm to 3 mm. In the case of forming a multicolor image, the effective thickness of the electrodeposition liquid is preferably in the range of 0.1 mm to 15 mm.
[0056]
If the electrodeposition liquid surface is directly exposed to the air surface, a minute wave may be generated on the surface or the liquid may be swelled, causing optical scattering and unnecessary refraction, which may cause distortion of the optical image. Because to improve it, Maintaining uniform liquid thickness Set the mechanism and cover the surface of the electrodeposition liquid for image exposure with a translucent material, thereby controlling the smoothness and thickness of the liquid surface with high precision, and setting the liquid level stability by this mechanism Then, optical loss and distortion on the liquid surface are suppressed. Cover the exposed area, that is, the image recording area Maintaining uniform liquid thickness The mechanism is preferably formed of a material having a transmittance in the exposure light principal wavelength region of 30% or more, preferably 50% or more. The member covering the image recording region preferably has a thickness in the range of 0.1 mm to 15 mm, and more preferably in the range of 0.2 mm to 3 mm. this Maintaining uniform liquid thickness By adopting the means, it becomes possible not only to keep the light irradiation efficiency at a high level, but also to realize image formation with high image sharpness and high resolving power by suppressing light scattering.
Further, since exposure from the electrodeposition liquid side is possible, there is an advantage that the degree of freedom of the material constituting the substrate is widened.
【Example】
[0057]
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
Example 1
A transparent conductive film 14 made of ITO is formed on a glass substrate 12 having a thickness of 5 mm by sputtering to a thickness of 0.9 μm, and further 0.5 μm of TiO 2 is formed. ₂ 16 is formed. Next, TiO ₂ In order to improve the 16 photocurrent characteristics, reduction treatment is performed. The reduction treatment was performed by annealing at 410 degrees for 10 minutes in pure nitrogen gas mixed with 3% hydrogen gas. In a tripolar arrangement which is common in electrochemical using the apparatus shown in FIG. 6, this is a styrene-acrylic acid random copolymer (molecular weight 14,000, hydrophobic group / (hydrophilic group) as an electrodeposition material. + Hydrophobic group) molar ratio of 73%, acid value of 90, glass transition temperature of 33 ° C., flow start point of 82 ° C., decomposition point of 251 ° C.) and azo-based magenta ultrafine pigment as a coloring material in a solid content ratio of 5 to 5 TiO 2 with respect to the saturated calomel electrode in the aqueous solution 22 containing the pigment dispersed in ₂ Using the electrode 16 as a work electrode, setting the work electrode to a bias potential of 1.6 V, a quartz glass plate having a thickness of 1.0 mm with an electrodeposition liquid layer 22 (thickness 0.2 mm) is disposed as a liquid thickness control member, The member is brought into close contact with the liquid surface, a liquid thickness control gap is set at the end, and a mercury xenon lamp (manufactured by Yamashita Denso, light intensity of wavelength 365 nm, 50 mW / cm from the surface of the member) ² ) Is irradiated with light through the photomask 28 for 4 seconds. ₂ An image pattern having a magenta thickness of 2 μm was formed only in the area irradiated with light on 16 surfaces. This image pattern was dried to reliably form a film.
[0058]
Next, an electrodeposition solution (thickness: 0.2 mm) containing a pigment in which a styrene-acrylic acid copolymer and an azo yellow ultrafine particle pigment, which are the same polymer materials as described above, are dispersed in a solid content ratio of 5 to 5 is used. Used for saturated calomel electrode with TiO ₂ The electrode is used as a working electrode, the working electrode is set to 1.6 V, a liquid thickness control member similar to magenta electrodeposition is disposed, and a mercury xenon lamp (manufactured by Yamashita Denso, wavelength 365 nm) is disposed from the surface side of the electrodeposition liquid. Light intensity of 50mW / cm ² ) When irradiated with light through a photomask for 4 seconds, TiO ₂ A yellow image pattern having a thickness of 1.7 μm was formed only in the region irradiated with light on the surface.
Similarly, TiO 2 is applied to a saturated calomel electrode using an electrodeposition solution (thickness 0.2 mm) containing a pigment in which a styrene-acrylic acid copolymer and a phthalocyanine-based cyan ultrafine pigment pigment are dispersed in a solid content ratio of 5 to 5. ₂ The electrode was used as a working electrode, the working electrode was set to 1.7 V, and a mercury xenon lamp (manufactured by Yamashita Denso, light intensity at wavelength 365 nm, 50 mW / cm from the surface of the electrodeposition liquid surface) ² ) When irradiated with light through a photomask for 4 seconds, TiO ₂ A cyan image pattern having a thickness of 1.7 μm was formed only in the region irradiated with light on the surface, and a color image layer was formed.
[0059]
After each color image layer was fixed, it was washed with pure water, and a styrene-acrylic acid copolymer (molecular weight 12,000, hydrophobic group / (hydrophilic group + hydrophobic group) molar ratio 73%, acid value 120). And carbon black powder (average particle diameter of 80 nm) in a water solution containing a pigment having a solid content ratio of 1: 4 with respect to a saturated calomel electrode with TiO ₂ The electrode is used as the working electrode, the working electrode is set to 2.0 V, and the electrodeposition liquid thickness is 0.2 mm. ₂ When only the area exposed and projected using the black mask on the surface was exposed for 2 seconds, a thin film containing carbon black was formed on the color image layer, and a black image portion could be formed.
After the black image portion is fixed, it is washed with pure water, and a plain paper is placed on the image forming surface. ² When placed in an oven at 190 ° C. for 10 minutes in a pressurized state and transferred, the plain paper is peeled off from the substrate, and the multicolor image created on the plain paper is transferred to the 256th floor at 1250 dpi on the plain paper. High-precision color image recording was achieved.
[0060]
(Example 2)
It is a production example of a color filter to which the image recording method of the present invention is applied.
A transparent conductive film made of ITO is formed on a glass substrate having a thickness of 2 mm by sputtering to a thickness of 0.8 μm, and further 0.5 μm of TiO 2 is formed. ₂ Is formed. Next, TiO ₂ Reduction treatment is performed to improve the photocurrent characteristics. The reduction treatment was performed by annealing at 370 ° C. for 20 minutes in pure nitrogen gas mixed with 4% hydrogen gas. In the same tripolar arrangement as in Example 1, the styrene-acrylic acid copolymer (molecular weight 16,000, hydrophobic group / (hydrophilic group + hydrophobic group) molar ratio 79% Acid value 110, glass transition temperature 41 ° C., flow start point 75 ° C., decomposition point 274 ° C.) and an aqueous solution containing a pigment in which an azo red ultrafine particle pigment is dispersed in a solid content ratio of 7 to 3 in saturated aqueous solution TiO to electrode ₂ The electrode is used as a working electrode, the working electrode is set to 1.9 V, the electrodeposition liquid layer 22 (thickness 0.1 mm) is made of a quartz glass plate having a thickness of 0.4 mm, and a doctor blade ( A U-shaped transparent liquid thickness control member provided with a liquid breakage blade is disposed, and a mercury xenon lamp (manufactured by Yamashita Denso, light intensity of wavelength 365 nm, 50 mW / cm from the surface of the member) ² ) When irradiated with light through a photomask for red for 5 seconds, TiO ₂ A red image pattern was formed only in the region irradiated with light on the surface.
[0061]
Next, the same styrene-acrylic acid copolymer as described above and a phthalocyanine green ultrafine pigment pigment were dispersed in a solid content ratio of 8 to 2 with an electrodeposition solution containing TiO 2 with respect to a saturated calomel electrode. ₂ The electrode is used as a working electrode, the working electrode is set to 1.9 V, the electrodeposition liquid thickness is 0.1 μm, and a mercury xenon lamp (manufactured by Yamashita Denso, light intensity at a wavelength of 365 nm) is used from the front side of the liquid surface as in the case of red image recording. 50 mW / cm ² ) When irradiated with light through a green photomask for 5 seconds, TiO ₂ A green image pattern was formed only in the region irradiated with light on the surface.
Similarly, a TiO 2 is saturated with respect to a saturated calomel electrode in an aqueous solution containing a pigment in which a styrene-acrylic acid copolymer similar to that described above and a phthalocyanine blue ultrafine pigment pigment are dispersed at a solid content ratio of 8 to 2. ₂ The electrode is used as a working electrode, the working electrode is set to 1.9 V, the electrodeposition liquid thickness is 0.1 μm, and a mercury xenon lamp (manufactured by Yamashita Denso, light intensity at a wavelength of 365 nm) is used from the front side of the liquid surface as in the case of red image recording. 50 mW / cm ² ) Is irradiated with light through a blue photomask for 5 seconds. ₂ A blue image pattern was formed only in the region irradiated with light on the surface, and a color image layer was formed.
[0062]
Next, after the formed color image layer was washed with pure water, the same styrene-acrylic acid copolymer and carbon black powder (average particle size 95 nm) as described above were dispersed at a solid content ratio of 5 to 5. TiO for saturated calomel electrode in aqueous solution containing pigment ₂ When the electrode was used as the working electrode and the voltage was applied for 4 seconds with the working electrode at 2.6 V, a thin film containing carbon black was formed only in the unformed region of the color image layer, and a black matrix was formed. After washing with water, the filter pattern part on the alkali-free glass plate was washed, and a protective layer was coated on the filter pattern part to obtain a UXGS specification color filter.
In this example, a voltage was applied without using light irradiation, but a good background color portion (black matrix) similar to Example 1 where light irradiation was performed was formed.
[0063]
(Example 3)
It is a production example of a color filter to which the image recording method of the present invention is applied.
A gold conductive film is formed on a 3 mm thick alumina substrate by sputtering, and TiO / TiO2 is formed on the thin film by a sol-gel method to a thickness of 0.6 μm. ₂ Was formed. The film is formed on the substrate by spin coating TiO ₂ A alkoxide solution (manufactured by Nippon Soda Co., Ltd., Atron NTi-092) was formed at a rotational speed of 1700 rpm for 30 seconds, and then heat-treated at about 500 ° C. for 1 hour. ₂ A film was formed. The reduction treatment was performed by annealing at 350 degrees for 10 minutes in pure nitrogen gas mixed with 3% hydrogen gas. As shown in FIG. 6, in a general tripolar arrangement similar to that of Example 1, the styrene-acrylic acid copolymer (molecular weight 16,000, hydrophobic group / (hydrophilic group + hydrophobic group) was used. A pigment having a solid content ratio of 8: 2 and a azo-based red ultrafine particle pigment having a molar ratio of 65%, an acid value of 105, a glass transition temperature of 15 ° C., a flow starting point of 65 ° C., and a decomposition point of 210 ° C. TiO 2 with respect to a saturated calomel electrode using an electrodeposition solution containing ₂ The electrode is used as a working electrode, the working electrode is 1.7 V, the electrodeposition liquid thickness is 0.08 mm, and it is made of a quartz glass plate with a thickness of 0.4 mm. A U-shaped transparent liquid thickness control member provided with a blade) is arranged, and a mercury xenon lamp (manufactured by Yamashita Denso, light intensity at wavelength 365 nm, 50 mW / cm) from the transparent member surface side. ² ) When irradiated with light through a photomask for 2 seconds, TiO ₂ A red filter pattern was formed only in the region irradiated with light on the surface.
[0064]
Next, in the aqueous solution containing the pigment obtained by dispersing the same styrene-acrylic acid copolymer and the phthalocyanine green ultrafine pigment as described above at a solid content ratio of 8 to 2, the saturated calomel electrode is subjected to TiO 2. ₂ The electrode is used as a working electrode, the working electrode is 1.7 V, the electrodeposition liquid thickness is 0.07 mm, and the quartz glass plate is 0.2 mm thick. A U-shaped transparent liquid thickness control member provided with a mercury xenon lamp (manufactured by Yamashita Denso, light intensity of wavelength 365 nm, 50 mW / cm) from the surface side of the transparent member. ² ) When irradiated with light through a photomask for 2 seconds, TiO ₂ A green filter pattern was formed only in the region irradiated with light on the surface. Similarly, TiO 2 is saturated with respect to a saturated calomel electrode in an aqueous solution containing a pigment in which the same styrene-acrylic acid copolymer and a phthalocyanine blue ultrafine pigment pigment are dispersed at a solid content ratio of 8 to 2. ₂ The electrode is used as a working electrode, the working electrode is 1.7 V, the electrodeposition liquid thickness is 0.07 mm, and the quartz glass plate is 0.3 mm thick. A U-shaped transparent liquid thickness control member provided with a mercury xenon lamp (manufactured by Yamashita Denso, light intensity of wavelength 365 nm, 50 mW / cm) from the surface side of the transparent member. ² ) When irradiated with light through a photomask for 2 seconds, TiO ₂ A blue filter pattern was formed only in the region irradiated with light on the surface, and a color filter layer was formed.
[0065]
Next, after the formed color filter layer is washed with pure water, a pigment in which the same styrene-acrylic acid copolymer and carbon black powder (average particle diameter of 80 nm) are dispersed in a solid content ratio of 7 to 3 is prepared. TiO for saturated calomel electrode in aqueous solution containing ₂ When the electrode was used as a working electrode, the working electrode was 2.6 V, and an electrodeposition potential was applied for 3 seconds, a copolymer thin film containing carbon black was formed only in the unformed region of the color filter layer. became. Thereafter, the filter layer and the black matrix were transferred onto a transparent glass substrate to prepare a color filter original plate. After washing it, a protective layer was coated on top of it to obtain a color filter.
In this example, a non-transparent substrate and a conductive film were used, but a good color filter was obtained by the exposure from the electrodeposition liquid side as in the case of using a transparent substrate and a transparent conductive film. TiO ₂ When the film was formed, the sol-gel method could be suitably used similarly to the case where the film was formed by the sputtering method.
[0066]
Example 4
A transparent conductive film made of ITO is formed on a 5 mm glass substrate by sputtering, and a silane gas glow discharge deposition method is formed on the ITO thin film by sputtering.
In the process of forming the a-Si film, an n-type a-Si film was deposited by introducing a diborane gas into the latter half of the film to form a photovoltaic layer having a thickness of 0.8 μm. Thereafter, heat treatment was performed at about 500 ° C. for 1 hour to increase the crystallinity of the Si film, and then a PN junction type poly-Si film was formed by two further doping treatments. As shown in FIG. 6, in a general tripolar arrangement as shown in FIG. 6, a styrene-acrylic acid copolymer similar to that in Example 1 and an azo-based magenta color ultrafine pigment in a solid content ratio of 7 are used. An electrodeposition liquid was obtained by dispersing the electrode in a pair 3 and using a Si electrode as a working electrode with respect to a saturated calomel electrode, the working electrode was set to 1.8 V, and an electrodeposition liquid layer having a thickness of 0.09 mm and a thickness of 0.5 mm. A U-shaped transparent liquid thickness control member is provided with a doctor blade (liquid cutting blade) at the end opening, and a He-Ne laser light source is provided from the transparent member surface side. The laser beam of the signal corresponding to the magenta image formation was used to form a magenta image pattern only in the light irradiated region on the Si surface. This image pattern was dried to reliably form a film.
[0067]
Next, a saturated calomel electrode is formed using an electrodeposition liquid containing a pigment in which a styrene-acrylic acid copolymer and an azo yellow ultrafine particle pigment, which are the same polymer materials as described above, are dispersed at a solid content ratio of 7: 3. On the other hand, a Si electrode is used as a working electrode, the working electrode is 1.7 V, an electrodeposition liquid layer having a thickness of 0.08 mm, a quartz glass plate having a thickness of 0.5 mm, and a doctor blade ( A U-shaped transparent liquid thickness control member provided with a (liquid breakage blade) is arranged, and a laser beam of a signal corresponding to yellow image formation is irradiated from the transparent member surface side using a He-Ne laser light source, A yellow image pattern was formed only in the region irradiated with light on the surface of Si.
Similarly, Si electrode is used as working electrode for saturated calomel electrode using electrodeposition liquid containing pigment in which styrene-acrylic acid copolymer and phthalocyanine cyan ultrafine pigment pigment are dispersed at a solid content ratio of 7 to 3. The working electrode is 1.7 V, an electrodeposition liquid layer having a thickness of 0.09 mm, a quartz glass plate having a thickness of 0.5 mm, and a doctor blade (liquid cutting blade) provided at the end opening. A transparent liquid thickness control member having a letter shape was placed, and a laser beam of a signal corresponding to cyan image formation was irradiated from the transparent member surface side using a He-Ne laser light source, and the surface of Si was irradiated with light. A cyan image pattern was formed only in the area, and a color image layer was formed.
[0068]
The formed color image layer was washed with pure water, and then contacted with the polymer resin solution in which carbon black powder (average particle diameter of 80 nm) was dispersed, and an electrodeposition potential of 2.5 V was applied to the substrate for 3 seconds. A copolymer thin film containing carbon black was formed only in the unformed region of the color image layer, and a black image portion as a background color was formed.
After the black image portion was fixed, it was washed with pure water, a 0.3 mm thick transparent film was placed on the image forming surface, the two substrates were heated to a roller surface temperature of 170 ° C., and 450 g / cm In the state of linear pressure, the two rolls are passed at a linear velocity of 12 mm / sec to perform heat and pressure treatment, and then the transparent film is peeled off from the substrate. As a result, the multicolor image created on the transparent film is transferred. It was. Then, it washed and coated the protective layer on the upper part, and obtained the color filter for liquid crystals.
[0069]
【The invention's effect】
According to the present invention, an image recording method with high resolution and high controllability applying photovoltaic power, which realizes a configuration in which the image forming layer can be exposed from the surface, that is, the electrodeposition liquid surface direction, and photocharge generation It is possible to provide an image forming method with a high degree of freedom in selecting constituent materials such as materials, conductive layer materials, and support substrates. Furthermore, it is possible to prevent the influence of random scattering and irregular reflection of light on the electrodeposition liquid surface with respect to the exposure from the electrodeposition liquid surface direction, and to improve the light energy efficiency and resolution of irradiation light.
Further, the present invention can be applied to a simple method for producing a color filter that does not use photolithography and has a small number of steps.
[Brief description of the drawings]
FIG. 1 is a graph showing changes in the amount of electrodeposition of an electrodeposition material when the conductivity is changed.
2A is a schematic diagram showing an energy band of a semiconductor in the case of a Schottky junction, and FIG. 2B is a PIN junction.
FIG. 3 is a graph showing dissolution characteristics associated with a change in pH of an electrodeposition material.
FIG. 4 is a graph showing the dissolution characteristics of two electrodeposition materials that exhibit different polarities and that can be used in combination with changes in pH.
5A to 5F are schematic cross-sectional views showing a color image recording process.
FIG. 6 is a schematic configuration diagram of an apparatus used in the image recording method of the present invention.
FIG. 7A includes a doctor blade used in the image recording method of the present invention. Maintaining uniform liquid thickness It is a top view which shows the aspect of a means, (B) is the schematic sectional side view.
FIG. 8A includes a gap forming unit used in the image recording method of the present invention. Maintaining uniform liquid thickness It is the schematic front sectional drawing which shows the aspect of a means, (B) is the schematic side sectional drawing.
[Explanation of symbols]
12 Substrate
14 Conductive film
16 Semiconductor thin film
18 Substrate
22 Electrodeposition liquid layer
26 Maintaining uniform liquid thickness means
34 Gap forming part ( Maintaining uniform liquid thickness means)
36 Doctor blade ( Maintaining uniform liquid thickness means)
38 Transparent exposure area ( Maintaining uniform liquid thickness means)

Claims (13)

A conductive film is formed on a substrate, and a substrate on which an organic semiconductor film or an inorganic semiconductor film having a photovoltaic function is formed is prepared.
On the substrate, a means for maintaining the uniformity of the thickness of the electrodeposition liquid layer and the smoothness of the surface of the electrodeposition liquid layer is disposed at a predetermined interval, and chemically dissolved or dissolved by changes in the colorant and pH. by introducing the electrodeposition solution containing the electrodeposition material and a liquid medium for precipitation and sedimentation, allowed forming the electrostatic Chakuekiso on a substrate,
Performs light irradiation to the organic semiconductor film or an inorganic semiconductor film having a photovoltaic function disposed on the substrate through the conductive Chakuekiso, electrostatic optionally include electrodeposition material in a portion electromotive force due to the irradiation light is generated An image recording method comprising a step of depositing a film to form an image. The main wavelength region of the irradiation light is any of the main absorption wavelength region of the electrodeposition liquid and the main absorption wavelength region of the means for maintaining the uniformity of the thickness of the electrodeposition liquid layer and the smoothness of the surface of the electrodeposition liquid layer. The image recording method according to claim 1, wherein the image recording method has different optical spectral characteristics.   3. The image recording method according to claim 1, further comprising a step of transferring an image formed by depositing the electrodeposition film onto an image holding material.   The effective thickness of the electrodeposition liquid in the image forming region for forming an image by selectively depositing an electrodeposition film containing an electrodeposition material on the portion where the electromotive force is generated by the light irradiation is in the range of 50 μm to 7 mm. The image recording method according to claim 1, wherein the image recording method is a recording medium.   2. The image recording method according to claim 1, wherein a multicolor image is formed by repeating the step of forming a plurality of single color images by changing the color tone of the color material.   The effective thickness of the electrodeposition liquid in an image forming region for forming a multicolor image by selectively depositing an electrodeposition film containing an electrodeposition material on a portion where an electromotive force is generated by the light irradiation is 0.1 mm to 15 mm. The image recording method according to claim 5, wherein the image recording method is in a range.   Using the electrodeposition film as the electrodeposition material, a colorant capable of forming a background color is contained, and after the multicolor image is formed by the method according to claim 5 or 6, the entire surface of the substrate is irradiated with light. An image recording method comprising: forming a background color portion by an electrodeposition film on an unformed portion of a plurality of color electrodeposition films constituting a multicolor image. 2. The image according to claim 1 , wherein the electrodeposition liquid is flowing between the substrate and the means for maintaining the uniformity of the thickness of the electrodeposition liquid layer and the smoothness of the surface of the electrodeposition liquid layer. Recording method. 9. The surface roughness Ra of the portion in contact with the electrodeposition liquid of the means for maintaining the uniformity of the thickness of the electrodeposition liquid layer and the smoothness of the surface of the electrodeposition liquid layer is 10 μm or less. Image recording method. The semiconductor thin film formed on the substrate is an n-type semiconductor, a pn junction in which an n-type semiconductor and a p-type semiconductor are sequentially stacked, or a semiconductor having a pin junction in which an n-type semiconductor, an i-type semiconductor, and a p-type semiconductor are sequentially stacked. The image recording method according to any one of claims 1 to 9 , wherein a compound having a carboxyl group in the molecule is used as the electrodeposition material. The semiconductor thin film formed on the substrate is a p-type semiconductor, a pn junction in which a p-type semiconductor and an n-type semiconductor are sequentially stacked, or a semiconductor having a pin junction in which a p-type semiconductor, an i-type semiconductor, and an n-type semiconductor are sequentially stacked. becomes, the image recording method according to any one of claims 1 to 9, characterized by using a compound having an amino group or imino group in the molecule as the electrodeposition material. The electrodeposition material has both a hydrophobic group and a hydrophilic group in the molecule, and the number of hydrophobic groups of monomer units constituting the polymer is in the range of 40% to 80% of the ratio of the total number of hydrophilic groups and hydrophobic groups, 50% or more of the hydrophilic group portion has a property that it can reversibly change from a hydrophilic group to a hydrophobic group by a change in pH, and contains a copolymer having an acid value of 30 to 600 and a fine particle colorant the image recording method according to any one of claims 1 to 9, characterized in that. The electrodeposition material, and units of precipitation and precipitation by changing the pH in the molecule, according to any one of claims 1 to 9, characterized by containing a compound having both a color material units Image recording method.

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