JP5315708B2 - Aqueous shading coating composition for display device, insulating shading film for display device, and display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based light-shielding coating composition for a display device, from which a light-shielding film having high light-shielding property, high surface electric resistance and excellent durability can be obtained, and to provide an insulating light-shielding film for a display device using the above light-shielding coating composition, and a display device achieving compatibility between high photosensitivity and excellent durability. <P>SOLUTION: The water-based light-shielding coating composition for a display device contains carbon black with the surface subjected to processing for hydrophilicity, a water-soluble resin having a polymerization degree from 1,000 to 3,000, and water, wherein a content ratio of the carbon black to the water-soluble resin is in a range from 1:3 to 1:10 by mass. The insulating light-shielding film for a display device is formed by using the above light-shielding coating composition, and the display device includes the insulating light-shielding film. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an aqueous light-shielding coating composition for display devices, an insulating light-shielding film for display devices, and a display device.

  In a display device such as an electric field drive type, as typified by a black matrix, there is a material that can provide both a large light shielding property (blackness) and a high surface electric resistance value to a finally obtained film. Required. Up to now, organic solvent-based printing inks and pastes have been used as light-shielding coating compositions that satisfy the above-mentioned required characteristics. Recently, however, water-based ones are also desired for the light-shielding coating compositions. . When a carbon black pigment having a large absorption in the visible light wavelength region and excellent light resistance is used as the water-based light-shielding coating composition, the resulting light-shielding film has a high light-shielding property.

  On the other hand, from the viewpoint of display devices, rewritable (rewritable) marking technology is highly expected as a hard copy technology that replaces paper, for reasons such as conservation of the global environment such as forest resource protection and office environment improvement such as space saving. It has become to. Hard copy of paper is 1) bright, high contrast, reflective full color display is possible, easy to read, high information display density, 2) light and thin, flexible structure, easy posture, lighting Wide selection of conditions 3) Has display memory characteristics, can display and store information without power supply, has little eye strain, and 4) Low cost and high productivity, so multiple sheets It is easy to obtain a list by simultaneous display, and it is easy to compare information, browse, etc., and has superior operational convenience not found in conventional electronic displays. For this reason, the paperless office has not been promoted as expected, and the information displayed on the electronic display is again printed as a hard copy on the paper and then browsed. Therefore, in addition to the rewritability for realizing resource saving and low waste, a display medium replacing paper is desired to reproduce various conveniences inherent to paper documents as described above.

  In recent years, research on rewritable marking technology using chemical changes caused by heating has been actively conducted, and leuco dye / amphoteric color-reducing agent system, leuco dye / developer / polar organic compound system, leuco dye / long-chain alkyl developer. Methods such as a color reducing agent system have been proposed. The system using these leuco dyes is a chemical change type utilizing a color change and decoloration accompanying opening and closing of the lactone ring.

  In addition, a method using physical changes due to heating has been proposed as a method for easily obtaining image maintainability, such as a polymer / long-chain alkyl low molecular system, a polymer blend system, and a polymer liquid crystal system. . The polymer / long-chain alkyl low molecular system is a system that controls the light scattering by changing the internal voids depending on the heating temperature, and the polymer blend system controls the light scattering by changing the microphase separation state according to the cooling rate. It is a method. The polymer liquid crystal system is a system in which the light scattering property is controlled mainly by changing the crystallinity depending on the cooling rate.

In addition, the element in which the liquid crystal and the photoconductor are laminated is used as a spatial light modulation element and an information recording medium for recording optical information, used as a parallel processing of image information, a projection display, a hologram, a light modulator, etc. Can do.
At least one of the photosensor and the electrode of the information recording medium is a semiconductive photosensor in which a photoconductive layer is laminated on an electrode and an information recording medium in which an information recording layer composed of a liquid crystal phase and a resin phase is laminated. Is a transparent electrode, and an information recording medium is shown in which electrodes are arranged on the optical axis so as to face each other so as to form an opposing gap, and a voltage can be applied between both electrodes (see, for example, Patent Document 1). ). The information recording medium uses a smectic liquid crystal having a memory property, and the turbidity of the smectic liquid crystal is modulated and recorded in accordance with the charge distribution on the photosensor generated by exposure. Sensitivity and high resolution recording can be realized.
Japanese Patent Laid-Open No. 9-120045

  An object of the present invention is to provide an aqueous light-shielding coating composition for a display device capable of obtaining a light-shielding film having a high light-shielding property, a high surface electrical resistance value, and an excellent durability, and a high light-shielding property and a high surface electrical resistance value. It is an object of the present invention to provide an insulating light-shielding film for display devices that can achieve high durability, and a display device that can achieve both good photosensitivity and excellent durability.

The above problems are solved by the present invention described below.
The invention according to claim 1 includes carbon black whose surface is hydrophilized by at least one of the following (1) and (2), a water-soluble resin having a polymerization degree of 1000 or more and 3000 or less, and water. And the content ratio of the said carbon black and the said water-soluble resin is the range of 1: 3.6 thru | or 1:10 by mass ratio, It is an aqueous | water-based light-shielding coating composition for display devices characterized by the above-mentioned.
(1) Surface treatment with humic acid salt
(2) It is encapsulated in a self-water dispersible resin and microencapsulated.

  The invention according to claim 2 is the water-based light-shielding paint composition for display devices according to claim 1, wherein the degree of polymerization of the water-soluble resin is 1000 or more and 2000 or less.

  The invention according to claim 3 is the water-based light-shielding coating composition for display device according to claim 1, wherein the water-soluble resin has a polymerization degree of 1300 or more and 1800 or less.

The invention according to claim 4 is characterized in that the content ratio of the carbon black and the water-soluble resin is 1: 3.6 to 1: 8 by mass ratio. It is the water-based light-shielding coating material composition for display devices of any one.

  The invention according to claim 5 is characterized in that the content ratio of the carbon black and the water-soluble resin is 1: 4 to 1: 6 by mass ratio. 2. A water-based light-shielding coating composition for a display device according to item 1.

  The invention according to claim 6 is characterized in that the carbon black whose surface has been hydrophilized is surface-treated with a humic acid salt having a specific surface area of 0.6 mg or more and 4 mg or less. Item 6. The water-based light-shielding coating composition for display device according to any one of Items 5 above.

The invention according to claim 7 is the display device according to any one of claims 1 to 6 , wherein the water-soluble resin is at least one selected from polyvinyl alcohol and derivatives thereof. It is a water-based light-shielding coating composition.

The invention according to claim 8 contains carbon black whose surface is hydrophilized by at least one of the following (1) and (2), and a water-soluble resin having a polymerization degree of 1000 or more and 3000 or less, An insulating light-shielding film for a display device, wherein a content ratio of carbon black and the water-soluble resin is in a range of 1: 3.6 to 1:10 by mass ratio.
(1) Surface treatment with humic acid salt
(2) It is encapsulated in a self-water dispersible resin and microencapsulated.

The invention according to claim 9 is the insulating light-shielding film for display devices according to claim 8 , wherein the degree of polymerization of the water-soluble resin is 1000 or more and 2000 or less.

The invention according to claim 10 is the insulating light-shielding film for display devices according to claim 8 , wherein the degree of polymerization of the water-soluble resin is 1300 or more and 1800 or less.

The invention described in claim 11, the content ratio of the carbon black and the water-soluble resin is in a mass ratio of 1: 3.6 to 1: of claims 8 to 10, characterized in that it is 8 The insulating light-shielding film for a display device according to any one of the above items.

The invention according to claim 12, content ratio of the carbon black and the water-soluble resin is in a mass ratio of 1: 4 to 1: any of claims 8 to 10, characterized in that it is 6 2. An insulating light-shielding film for a display device according to item 1.

The invention according to claim 13 is a pair of electrodes comprising an anode and a cathode, at least one of which is transparent or translucent, a display layer sandwiched between the electrodes, a photoconductor layer, and the photoconductor layer And a light absorption layer sandwiched between the electrodes, wherein the light absorption layer includes the insulating light-shielding film for a display device according to any one of claims 8 to 12. It is a device.

The invention according to claim 14 is a pair of electrodes comprising an anode and a cathode, at least one of which is transparent or translucent, a display layer sandwiched between the electrodes, a photoconductor layer, the display layer, and light A light absorption layer sandwiched between conductor layers, and comprising the insulating light-shielding film for a display device according to any one of claims 8 to 12 as the light absorption layer. It is a display device.

The invention according to claim 15 is the display device according to claim 13 or 14 , wherein the display layer is a liquid crystal layer.

The invention according to claim 16 is the display device according to claim 15 , wherein the liquid crystal layer is a liquid crystal layer containing a cholesteric liquid crystal and a transparent resin.

Invention of claim 17, wherein the photoconductive layer is displayed as claimed in any one of claims 13 to claim 16, characterized in that a layer configured to include an organic photoconductor It is a device.

The invention according to claim 18 is the display device according to any one of claims 13 to 17 , wherein the display layer and the photoconductor layer are held by a resin substrate. .

  According to the first aspect of the present invention, it is possible to obtain a light-shielding film having a high light-shielding property, a high surface electric resistance value, and an excellent durability as compared with the case where this configuration is not provided.

  According to the invention which concerns on Claim 2, compared with the case where the polymerization degree of water-soluble resin is not considered, a high surface electrical resistance value, favorable viscosity, film formability, and adhesiveness can be obtained.

  According to the invention which concerns on Claim 3, compared with the case where the polymerization degree of water-soluble resin is not considered, a high surface electrical resistance value, favorable viscosity, film-forming property, and adhesiveness can be obtained.

  According to the invention which concerns on Claim 4, compared with the case where the content ratio of carbon black and water-soluble resin is not considered, the light shielding film which has high light-shielding property and high surface electrical resistance value can be obtained.

  According to the invention which concerns on Claim 5, compared with the case where the content ratio of carbon black and water-soluble resin is not considered, the light shielding film which has high light-shielding property and high surface electrical resistance value can be obtained.

  According to the invention which concerns on Claim 6, compared with the case where surface treatment conditions are not considered, the light shielding film which has high light-shielding property, a high surface electrical resistance value, and outstanding durability can be obtained.

According to the invention which concerns on Claim 7 , compared with the case where the kind of water-soluble resin is not considered, the light shielding film excellent in the film formability, adhesiveness, and the lamination | stacking property in a display device can be obtained.

According to the invention which concerns on Claim 8 , compared with the case where it does not have this structure, a high light-shielding property, a high surface electrical resistance value, and the outstanding durability can be obtained.

According to the invention which concerns on Claim 9 , compared with the case where the polymerization degree of water-soluble resin is not considered, a high surface electrical resistance value and favorable film formation property can be obtained.

According to the invention which concerns on Claim 10 , compared with the case where the polymerization degree of water-soluble resin is not considered, a high surface electrical resistance value and favorable film formation property can be obtained.

According to the invention which concerns on Claim 11 , compared with the case where the content ratio of carbon black and water-soluble resin is not considered, a high light-shielding property and a high surface electrical resistance value can be obtained.

According to the invention which concerns on Claim 12 , compared with the case where the content ratio of carbon black and water-soluble resin is not considered, a high light-shielding property and a high surface electrical resistance value can be obtained.

According to the invention which concerns on Claim 13 , compared with the case where it does not have this structure, favorable photosensitivity and outstanding durability can be made compatible.

According to the invention which concerns on Claim 14 , compared with the case where it does not have this structure, favorable photosensitivity and outstanding durability can be made compatible.

According to the fifteenth aspect of the present invention, a high-contrast and high-definition display device can be obtained as compared with the case where the aspect of the display layer is not considered.

According to the sixteenth aspect of the present invention, a display device with high contrast and high definition can be obtained as compared with the case where the type of liquid crystal is not taken into consideration.

According to the seventeenth aspect of the present invention, it is possible to obtain a display device having power saving and a high writing speed as compared with the case where the aspect of the photoconductor layer is not taken into consideration.

According to the eighteenth aspect of the present invention, it is possible to obtain a display device that is lighter, thinner, and less fragile than the case without this configuration.

<Water-based shading coating composition for display device>
Hereinafter, preferred embodiments of the water-based light-shielding coating composition for display devices (hereinafter, simply referred to as “light-shielding coating composition”) will be described in detail.

(Light-shielding paint composition according to the first embodiment)
The light-shielding coating composition according to the first embodiment contains 0.6 mg per specific surface area as a carbon black containing a water-soluble resin having a degree of polymerization of 1000 or more and 3000 or less and water and having a hydrophilic surface. The carbon black surface-treated with 4 mg or less of humic acid salt is contained. The content ratio of the carbon black and the water-soluble resin is in the range of 1: 3.6 to 1:10 by mass ratio.

With the above configuration, the following required characteristics can be satisfied.
(a) Insulating light-shielding film for display device having a film thickness of 3 μm (Here, “insulating” in this specification means that the surface resistance value is 1 × 10 ¹³ Ω / □ or more. The light transmittance of an insulating light shielding film for a display device is sometimes simply referred to as “insulating light shielding film”) is 1% or less in a wavelength region of 400 nm to 800 nm (light shielding property)
(b) The surface resistance value of the insulating light-shielding film having a film thickness of 3 μm is 10 ¹³ (Ω / □) or more (surface electrical resistance).
(c) Insulating light-shielding film has excellent light resistance and storage stability and is stable for a long time (durability)

-Carbon black surface-treated with humic acid salt-
First, an aqueous dispersion composition of carbon black whose surface is hydrophilized with a humic acid salt will be described in detail. The above-described carbon black aqueous dispersion composition is a small particle that can reach the pigment (carbon black) by mechanical dispersion force by contacting an aqueous solution of a surface treatment agent containing a humate with carbon black particles at least in water. Disperse until a particle having a particle size is obtained to obtain water-dispersed particles. Then, it can manufacture by adding the organic compound type additive which envelops this dispersion particle or can adsorb | suck to the surface.
Specifically, first, in a liquid medium containing 60% by mass or more of water, humic acid salt dissolved in water is added so that the specific surface area of carbon black is 0.6 mg / m ² or more and 4 mg / m ² or less. Mix. Next, a carbon black dispersion having a mean particle size in the range of 0.06 μm to 0.17 μm and a maximum particle size of 0.6 μm or less is dispersed by a media mill having a media volume filling rate of 100%. obtain. Then, it can manufacture by mixing an organic solvent and an organic compound type additive.

Here, carbon black is generally a carbon powder obtained by thermal decomposition or incomplete combustion of natural gas or liquid hydrocarbon (heavy oil, tar, etc.). These are classified into channel black, furnace black, lamp black and the like according to the production method and are commercially available.
The type of carbon black that can be used is not particularly limited, and conventionally known carbon black such as acidic carbon black, neutral carbon black, and alkaline carbon black can be used. Preferably, the oil absorption amount is 60 ml / 100 g or more and 200 ml / 100 g or less, the specific surface area is 50 m ² / g or more and 300 m ² / g or less, more preferably the oil absorption amount is 80 ml / 100 g or more and 120 ml / 100 g or less, and the specific surface area is 80 m ² / g or more and 200 m or less. Powdered carbon black in the range of ² / g or less can be suitably used.
When the carbon black as a pigment is dispersed in a liquid medium (water or the like), the pigment content is preferably 5% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 20% by mass or less.

As the humic acid salt that is the surface treatment agent for carbon black, a salt of humic acid that is a non-agricultural and non-nitric acid-treated polyphenol type polycarboxylic acid is preferable. Product names: CHA-02 and CHA-07 are preferably used. Amount of humic acid salt, 0.6 mg / ^{m 2} or more 4 mg / ^{m 2} preferably in the following range with respect to the specific surface area of the carbon black. The addition amount is more preferably 1 mg / m ² or more and 3.5 mg / m ² or less, and particularly preferably 1.5 mg / m ² or more and 3 mg / m ² or less. By being above the lower limit value, excellent dispersion stability can be obtained, and when it is not more than the upper limit value, water resistance and a decrease in coloring density are suppressed while giving a favorable effect on dispersion.

  The humic acid salt is preferably dissolved in water in advance while adjusting the pH, and the pigment is added. The dissolution of the humic acid salt is preferably used in a range of 0.1% by mass to 30% by mass with respect to the aqueous medium, and more preferably in the range of 1.0% by mass to 10% by mass. In dissolving the humic acid salt, a general apparatus such as a disper stirring or a homomixer can be used. In addition, after melt | dissolution, from a viewpoint of removing the undissolved substance in a solution, it can filter-process using the net | network made from stainless steel of 100 mesh or more and 200 mesh or less, for example.

  The dispersion of the carbon black water dispersion can be performed using a mill medium and a pulverizer. Specifically, after the preliminary dispersion treatment, the dispersion treatment is performed by wet pulverization in an aqueous medium for 3 hours to 10 hours, and the pigment dispersion is performed to a fine dispersion level. The average particle size of the finely dispersed carbon black is preferably 300 nm or less, more preferably 170 nm or less, and particularly preferably 100 nm or less.

  Dispersers used for the above dispersion include ball mills, attritors, dissolvers, homomixers, fourojet mixers, impeller mills, colloidal mills, sand mills [for example, bead mills, sand gliders, super mills, agitator mills, dyno mills (trade names)], etc. Is mentioned. In addition, as a preliminary disperser, a high-speed dissolver, a homomixer, etc. are preferable, and a continuous homomixer such as a TK homomic line mill (manufactured by Special Machinery Corporation) can be preferably used. By performing the pre-dispersion, it is possible to easily pass the 44 μm stainless steel net, and it becomes easy to introduce the next process into the main dispersion.

  A high speed media mill is preferably used for this dispersion. Examples of the filling medium (medium) used here include glass beads, zirconia beads, magnetic beads, and stainless steel beads. Preferably, zirconia beads having a diameter of 0.2 mm or more and 2.0 mm or less (more preferably 0.3 mm or more and 1.0 mm or less) are used, the media volume filling rate to the mill can be 100%, and the peripheral speed is 5 m / A disperser having equipment that can be set in a range of s to 15 m / s can be preferably used. When the media filling rate is 100%, a desired dispersion can be obtained in a short time and a dispersion having a desired particle size distribution can be obtained. Further, when the peripheral speed is equal to or higher than the above lower limit value, dispersion can be performed in a short time, while when the peripheral speed is equal to or lower than the above upper limit value, a decrease in the viscosity of the dispersion liquid is suppressed, and the centrifugal force causes the media to move outside the vessel wall. This prevents the phenomenon of being pressed against the surface and enables effective dispersion.

A dispersion stock solution is obtained by subjecting the above carbon black water dispersion to a filtration treatment using a filter having a particle trapping ratio of 19.5 μm or more and 99.5% or more. Further, for example, a pH adjuster, a water-soluble resin, a resin emulsion, a preservative, etc. are added to the pigment dispersion stock solution as an organic solvent and an organic compound-based additive (water-soluble additive) to obtain a final dispersion. It is done.
The carbon black aqueous dispersion is available as an aqueous dispersion stably dispersed in water, and examples thereof include “TBK-BC3” manufactured by Taisei Nanotech Co., Ltd.

  The said organic solvent used here is a water-soluble organic solvent, for example, C1-C4 alkyl, such as methyl alcohol, ethyl alcohol, n-butyl alcohol, isopropyl alcohol, n-propyl alcohol, isopropyl alcohol, etc. Alcohols; ethers such as tetrahydrofuran dioxane; amides such as dimethylformamide and diacetamide; polyalkylene glycols such as polyethylene glycol and polypropylene glycol; alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol and diethylene glycol; glycerin; Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol methyl ether, diethylene glycol ether Ethers, lower alkyl ethers of polyhydric alcohols such as triethylene glycol ethyl ether; N- methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidine and the like. Of these many water-soluble organic solvents, lower alkyl ethers of polyhydric alcohols are preferred.

Examples of the pH adjuster include aqueous ammonia, diethanolamine, triethanolamine, triethylamine, alkali metal hydroxides such as sodium hydroxide, and the like.
Further, as the organic compound-based additive, in addition to the above components, a resin, a surfactant, an antifoaming agent, a preservative, and the like may be added. For example, examples of the resin include water-soluble resins and resin emulsions. Examples of the water-soluble resin include casein, polyvinyl ether, polyvinyl pyrrolidone, methyl cellulose, hydroxyethyl cellulose, polyethylene glycol, polyvinyl alcohol, styrene-acrylic acid ester, polyacrylic acid ester, and polymethacrylic acid ester. Resin emulsions include polyacrylates, polymethacrylates, styrene-acrylic acid copolymers, styrene-maleic acid copolymers, urethane-acrylic acid copolymers, vinyl acetate esters, ethylene-vinyl acetate copolymers. Examples thereof include a polymer, a vinyl acetate-acrylic acid copolymer, and an acrylonitrile-butadiene copolymer.

Carbon black surface-treated with humic acid salt by mixing and stirring the additive by the above-mentioned method, and performing filtration using a filter with a particle capture rate of more than 0.6 μm of 99.8% or more. An aqueous dispersion can be obtained.
When this water-based pigment dispersion is used, it has superior light resistance compared to conventional dye-based dispersions, and also has excellent long-term dispersion stability, which is a problem with water-based pigment dispersions, and improves storage stability. Is obtained.

-Water-soluble resin-
A water-soluble resin having a polymerization degree of 1000 or more and 3000 or less is added to the light-shielding coating composition according to the first embodiment.
The water-soluble resin is soluble in water, does not adversely affect the dispersibility of the carbon black, and can impart high insulation and chemical resistance to an insulating light-shielding film obtained by applying to a substrate and drying Is preferred. Examples of the water-soluble resin include completely saponified or partially saponified polyvinyl alcohol, water-soluble polyvinyl acetal, water-soluble polyvinyl formal, polyacrylamide, polyvinyl pyrrolidone, poly (meth) acrylic acid, and water-soluble poly (meth) acrylic acid copolymer. Examples of the polymer include polyalkylene oxide, water-soluble polyester, polyethylene glycol, and water-soluble maleic acid resin. Among these, polyvinyl alcohol derivatives such as polyvinyl alcohol, water-soluble polyvinyl acetal, and water-soluble polyvinyl formal are particularly preferable from the viewpoint of excellent film forming ability and chemical resistance.

Further, there is a correlation between the degree of polymerization of the resin and the electric resistance value of the resin, and the electric resistance value tends to increase as the degree of polymerization increases. In particular, in order to obtain an insulating light-shielding film having a high surface electric resistance value, a water-soluble resin having a polymerization degree of 1000 or more and 3000 or less is used. When the degree of polymerization is less than 1000, the surface resistance value decreases, and when it exceeds 3000, the viscosity of the light-shielding coating composition increases, making it difficult to apply to the support.
Furthermore, the thing of the range of 1000 or more and 2000 or less is more preferable, and the thing of the range of 1300 or more and 1800 or less is especially preferable.

  Examples of the water-soluble resin include “Kuraray Poval PVA-HCW”, “Kuraray Poval PVA-217C”, “Kuraray Poval PVA-217EE”, “Exeval RS-2617”, “Exeval RS-2713” and the like manufactured by Kuraray Co., Ltd. As the polyvinyl acetal, “S REC KW-1” manufactured by Sekisui Chemical Co., Ltd. can be exemplified. These water-soluble resins can be used alone or in admixture of two or more.

  When the insulating light shielding film formed using the light shielding coating composition according to the first embodiment is used as a black matrix of a liquid crystal display device, the insulating light shielding film is in direct contact with the liquid crystal material.

  In addition, in the insulating light-shielding film formed using the light-shielding coating composition according to the first embodiment, it is preferable to increase the surface electrical resistance value so as not to affect the electrical characteristics of the display device. From this viewpoint, it is preferable to adjust the conductivity of the carbon black.

In the light-shielding coating composition according to the first embodiment, the content ratio of the carbon black (hydrophilized carbon black) surface-treated with the humic acid salt and the water-soluble resin is expressed as a mass ratio. By setting it to 1: 3 thru | or 1:10, it became possible to give simultaneously the high light-shielding property and high surface electrical-resistance value which are contradictory to the obtained insulating light-shielding film. When the content ratio of the carbon black and the water-soluble resin exceeds 1: 3, that is, when the content of the hydrophilic carbon black is increased, the light shielding property of the obtained insulating light shielding film is improved, but the surface electrical resistance value is decreased. On the contrary, when the content is less than 1:10, that is, when the content of the hydrophilic carbon black is lowered, the surface electric resistance value of the obtained insulating light-shielding film is improved, but the light-shielding property is lowered. The mass ratio is more preferably 1: 3 to 1: 8, and particularly preferably 1: 4 to 1: 6.
At this time, it is desirable from the viewpoint of controlling the conductivity of the insulating light-shielding film that the concentration of carbon black, water-soluble resin, or other solid content in the light-shielding coating composition is 5% by mass or more and 15% by mass or less.

  Moreover, an organic solvent having compatibility with water may be added within a range in which the water-soluble resin is not precipitated. Examples of the organic solvent include lower alcohols such as methanol, ethanol, isopropyl alcohol, and butyl alcohol, acetone, and dioxane. The non-volatile content concentration of the light-shielding coating composition is preferably 5% by mass or more and 20% by mass or less.

The light-shielding coating composition according to the first embodiment includes an additive such as an antifoaming agent in addition to the carbon black water dispersion and the water-soluble resin aqueous solution, an ultrasonic dispersion method, a homogenizer method, a ball mill method, It can mix and prepare using well-known and usual dispersion mixing methods, such as a mixer method, a sand mill method, a kneader method.
In the case where an insulating light-shielding film is formed on an electric field driven display device such as a liquid crystal display device using the light-shielding paint composition according to the first embodiment, display is performed when impurities are contained in the light-shielding paint composition. The display characteristics of the device may be impaired. For this reason, when carbon black is used after removing excessive salt using an ion exchange resin or the like, deterioration of the display layer due to impurity diffusion can be reduced. However, since the dispersibility of carbon black in water decreases when no salt is present, the electrical conductivity of the water-soluble light-shielding coating composition containing carbon black, a water-soluble resin and water is 20 μS / cm or more and 100 μS / It is desirable to remove ions that become impurities so as to be equal to or less than cm.

(Light-shielding paint composition according to the second embodiment)
The light-shielding coating composition according to the second embodiment includes a water-soluble resin having a degree of polymerization of 1000 or more and 3000 or less, and water, and a self-dispersible resin as carbon black whose surface is hydrophilized. Contains encapsulated microencapsulated carbon black. The content ratio of the carbon black and the water-soluble resin is in the range of 1: 3.6 to 1:10 by mass ratio.

With the above configuration, the following required characteristics can be satisfied.
(a) The light transmittance of the insulating light-shielding film for display devices having a film thickness of 3 μm is 1% or less in the wavelength region of 400 to 800 nm (light-shielding property)
(b) The surface resistance value of the insulating light-shielding film having a film thickness of 3 μm is 10 ¹³ (Ω / □) or more (surface electrical resistance).
(c) Insulating light-shielding film has excellent light resistance and storage stability and is stable for a long time (durability)

  In the light-shielding paint composition according to the second embodiment, the other composition is the above except that the microencapsulated carbon black encapsulated by a self-water dispersible resin is used as the carbon black whose surface has been hydrophilized. The composition used in the light-shielding coating composition according to the first embodiment can be employed as it is.

-Microencapsulated carbon black-
In the light-shielding coating composition according to the second embodiment, the self-water dispersible resin (A) forming a microcapsule (so-called microcapsule shell resin) exhibits self-water dispersibility by neutralization. In the synthetic resin (1) having an acid group, a self-water dispersible resin in which at least a part of the acid group is neutralized with the base (2) is used. This self-water dispersible resin (A) is preferable because it has good wettability with an achromatic pigment and good compatibility with a dye.

Examples of the acid group that the synthetic resin (1) has include a carboxylic acid group, a sulfonic acid group, and a sulfinic acid group, and are not particularly limited, but among these, a carboxylic acid group is more preferable.
The acid value of the synthetic resin (1) is preferably from 50 to 280. The microencapsulated carbon black obtained when the acid value of the synthetic resin (1) is 50 or more is excellent in water dispersion stability, and the acid value of 280 or less is a water-dispersible resin dissolved in an organic solvent. Aggregation that occurs during neutralization with a base is suppressed, and dissolution of the resin is also suppressed when added to water. From the above viewpoint, the acid value of the synthetic resin (1) to be used is in the range of 50 to 280, more preferably in the range of 70 to 250.

As this synthetic resin (1), a vinyl copolymer having a carboxylic acid group is preferable, for example, substituted styrene such as styrene or α-methylstyrene, acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid butyl ester, acrylic acid. At least one monomer unit selected from acrylic acid esters such as 2-ethylhexyl ester, methacrylic acid methyl ester, methacrylic acid ethyl ester, methacrylic acid butyl ester, and methacrylic acid ester such as 2-ethylhexyl methacrylate; and acrylic acid, A vinyl copolymer containing at least one monomer unit selected from methacrylic acid is preferred. More preferably, it is a vinyl copolymer using a styrene monomer, an acrylic acid monomer, or a methacrylic acid monomer as an essential monomer component. Vinyl copolymers using these monomers can be said to be extremely stable resins because their molecular structure does not have groups that are easily fragmented by light, heat, solvents, etc., such as ester bonds.
In particular, the constituent ratio of these essential monomer components is 60 mol% or more and 90 mol% or less of styrene monomer, 5 mol% or more and 15 mol% or less of acrylic acid monomer, and 5 mol% or more and 25 mol% or less of methacrylic acid monomer. It is preferable that

  Although there is no restriction | limiting in particular also about the molecular weight range of the said synthetic resin (1), The thing of the molecular weight of 1000-100000 is more preferable. Of course, the synthetic resin (1) is not particularly limited as long as it forms a stable microcapsule in combination with the aqueous medium (C) described later. May be.

  Neutralization with the base (2), that is, neutralization with an alkaline neutralizing agent, is preferably neutralized to such an extent that the synthetic resin (1) does not dissolve in water. You may add to. In addition, it is preferable to neutralize 60 mol% or more of the acid groups of the synthetic resin (1). When the neutralization rate is 60 mol% or more, the resulting microencapsulated carbon black is fine and excellent in dispersion stability.

  The content of the self-water dispersible resin (A) in the aqueous medium (C) is not particularly limited, but is 0.5% by mass or more and 20% by mass in the finally obtained light-shielding coating composition. It is preferable to set it as mass% or less.

  Examples of the base (2) include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide and lithium hydroxide, basic substances such as ammonia, triethylamine and morpholine, in particular triethanolamine, diethanolamine, N -Alcohol amines such as methyldiethanolamine can be used. Among these, the use of alcohol amine is particularly preferable. When the alcohol amine is used, the dispersion stability of the microencapsulated carbon black is more excellent, and particle aggregation due to evaporation of moisture or organic solvent is less likely to occur, so that a better aqueous dispersion can be obtained.

  In the light-shielding coating composition according to the second embodiment, as a method for neutralizing the synthetic resin (1) having an acid group by adding the base (2), an organic solvent solution of the synthetic resin (1) is used in advance. And a method of adding the organic resin solution of the synthetic resin (1) and the aqueous medium (C) to the aqueous medium when the best conditions are selected. Good.

In the light-shielding coating composition according to the second embodiment, as described above, carbon black is used as the black pigment.
The dye is not particularly limited but is preferably a dye that can be dissolved in an organic solvent. Typical examples include azo dyes such as monoazo and disazo, metal complex dyes, naphthol dyes, anthraquinone dyes, indigo dyes, carbonium dyes, quinoimine dyes, cyanine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes. Examples thereof include, but are not limited to, dyes, naphthalimide dyes, perinone dyes, phthalocyanine dyes, triallylmethane dyes, and the like. These dyes may be present in a partially dispersed form, but it is preferable to select those that dissolve in the shell resin forming the microcapsules.

  The microencapsulated carbon black in the light-shielding coating composition according to the second embodiment exists as colored resin particles in which carbon black is encapsulated by a self-water dispersible resin dyed.

  The total amount of dye and carbon black used in the light-shielding coating composition according to the second embodiment is not particularly limited, but is 0.5% by mass or more in the finally obtained light-shielding coating composition. It is preferable to set it as 20 mass% or less. Moreover, as a mass ratio of the dye with respect to an achromatic pigment, it is desirable to use in the range of 1 mass% or more and 50 mass% or less.

  The colored resin particles (colored microcapsule particles) in the light-shielding coating composition according to the second embodiment are a method of performing microencapsulation of carbon black together with dyeing of a resin with a dye, and carbon after dyeing a resin with a dye. It can be formed by a method of microencapsulating black, a method of dyeing resin particles (microcapsule particles) containing carbon black with a dye, or the like.

  An aqueous dispersion containing the formed colored microcapsule component (that is, an aqueous dispersion in which microencapsulated carbon black encapsulated by a self-water dispersible resin dyed is dispersed in an aqueous medium) is, for example, a synthetic resin. Add the dye and carbon black to the organic solvent solution of (1), mix by dissolving and dispersing using a stirrer or dispersing device, and then mix it with the aqueous medium (C) in the presence of the base (2) Can be prepared.

  More specifically, an aqueous dispersion containing microencapsulated carbon black can be easily produced by preparing it by a microencapsulation method called a phase inversion emulsification method. Production by the phase inversion emulsification method is basically the first step, in which a synthetic resin (1) that is soluble in an organic solvent and exhibits self-water dispersibility by neutralization is dissolved in an organic solvent, and carbon black and a dye are further added. Dispersing / dissolving in the resin solution (mill base process), and as a second step, the solution is mixed with an excess amount of an aqueous medium in the presence of the base (2) to disperse the dyed water. And a step of obtaining resin particles encapsulating an achromatic pigment with a resin (encapsulation step). Furthermore, as a third stage, a process (solvent removal process) for removing the organic solvent used in the mill base process in the first stage may be performed.

  In the production of the aqueous dispersion containing the microencapsulated carbon black, it is preferable that the dye and the carbon black are previously dispersed or dissolved in a self-water dispersible resin before being dispersed in an aqueous medium. .

  Moreover, when encapsulating using the phase inversion emulsification method, examples of the organic solvent used in the first step include ketone solvents such as acetone, dimethyl ketone, and methyl ethyl ketone; alcohol solvents such as methanol, ethanol, and isopropyl alcohol; Ether solvents such as tetrahydrofuran and dioxane; Chlorine solvents such as chloroform and methylene chloride; Aromatic solvents such as benzene and toluene; Ester solvents such as ethyl acetate; Glycol ethers such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether Any solvent that dissolves the resin, such as amides, can be used. In the case of the phase inversion emulsification method using the synthetic resin (1), at least one combination selected from ketone solvents and alcohol solvents is preferable.

  In the light-shielding coating composition according to the second embodiment, additives such as a dispersant, a plasticizer, an antioxidant, and an ultraviolet absorber may be used together with an organic solvent, a resin, a dye, and carbon black. In the second encapsulation step, resin, dye and carbon black are mixed in the solvent, dissolved and dispersed using a stirrer and a dispersing device, and the resulting organic solvent solution and water are essential components. By mixing with an aqueous medium.

  In the second stage encapsulation step, the mill base obtained in the first stage is encapsulated by mixing water or an aqueous solution in the presence of the base (2). Depending on the carbon black and dye used, loose aggregation of the capsules may occur. Therefore, it is preferable to add and add water or an aqueous solution after the encapsulation. In this step, a colored solution containing a self-water dispersible resin may be added to an aqueous medium containing water as an essential component. Conversely, it is more uniform to add an aqueous medium to a colored solution containing the resin. It is preferable at the point from which the aqueous dispersion of a particle diameter is obtained. It can also be obtained by forcibly emulsifying with a surfactant. However, surfactants and protective colloids are more preferably not used because they tend to lower the physical properties of the finally obtained particles.

  Base (2) is added to the millbase or aqueous solution. The water used in the aqueous medium is preferably a grade higher than ion-exchanged water.

  As the third stage, after the encapsulation is completed, a solvent removal process for removing the organic solvent that dissolves the synthetic resin (1) used in the first stage mill base process may be performed. As a result, a stable aqueous dispersion can be obtained while suppressing the swelling and aggregation of the colored microcapsules. In this solvent removal step, water may be further removed. Of course, this third step may be omitted.

  In addition to these, additives such as a pH adjusting agent, a dispersion / antifoaming agent, a preservative, and a chelating agent can be added. These additives can be added in an appropriate process from the first stage to the final stage, but it is preferable to avoid adding the additive after the final filtration. After the final composition adjustment is completed, it is preferable to remove the large particle size by filter filtration, centrifugation, or the like to obtain an aqueous dispersion containing microencapsulated carbon black.

In addition, it is as follows when the suitable example manufactured by a phase inversion emulsification method is demonstrated.
As a synthetic resin, at least one monomer selected from the group consisting of styrene, substituted styrene and (meth) acrylic acid ester and (meth) acrylic acid are copolymerized to have an acid value of 50 to 280 and a molecular weight of 1000. A vinyl copolymer of 100,000 or less is obtained. The vinyl copolymer is dissolved in an organic solvent to prepare a synthetic resin solution, and the synthetic resin solution, carbon black, and a dye that can be dissolved in the synthetic resin as a dye are mixed, kneaded and colored. Get the mill base. The mass ratio of the dye to carbon black is in the range of 1% by mass to 50% by mass. A base capable of neutralizing the acid group of the synthetic resin is added to the colored mill base, and the mixture is stirred and mixed, and an aqueous medium containing water is added dropwise with stirring to perform phase inversion emulsification. As a result, an aqueous dispersion containing microencapsulated carbon black in which colored resin particles in which carbon black is encapsulated by a self-water dispersible resin dyed is dispersed in an aqueous medium is obtained.
In addition, the addition amount of the base as the alkali neutralizing agent at this time is within the range of neutralizing 60 mol% or more of the acid groups. When the capsules are loosely aggregated due to the carbon black or dye used, water or an aqueous solution is additionally mixed and dispersed again after the encapsulation. Further, the organic solvent used for dissolving the synthetic resin is removed by distillation under reduced pressure to obtain a carbon black aqueous dispersion composition.

  The light-shielding coating composition according to the first and second embodiments, which is a preferable aspect described above, can be used for an insulating light-shielding film. Specifically, it is used as a water-based light-shielding coating composition used in the field of black matrix members for color filters used in liquid crystal displays, insulating members for reflective display devices utilizing selective reflection and spatial light modulators, etc. be able to. Further, the insulating light-shielding film obtained by using the light-shielding coating composition is composed of a liquid crystal display layer, an organic photoconductor layer, and a light absorption layer, and a liquid crystal display device that performs display recording with high resolution and a large amount of information Can be used.

<Insulating light shielding film for display devices>
(Insulating light shielding film according to the third embodiment)
Next, the insulating light shielding film according to the third embodiment will be described in detail as a preferable aspect of the insulating light shielding film for display devices.
The insulating light-shielding film according to the third embodiment contains carbon black whose surface is hydrophilized and a water-soluble resin having a polymerization degree of 1000 to 3000, and the carbon black and the water-soluble resin Is in a range of 1: 3.6 to 1:10 by mass ratio. The insulating light-shielding film can be formed by applying the light-shielding coating composition according to the first or second embodiment described above onto a substrate and drying it.

  As the coating method, spin coating method, pull-up coating method, air doctor coating method, blade coating method, rod coating method, knife coating method, squeeze coating method, impregnation coating method, reverse roll coating method, transfer coating method, gravure coating method , A kiss roll coating method, a cast coating method, a spray coating method, a curtain coating method, a calendar coating method, an extrusion coating method, an electrostatic coating method, a bar coating method and the like can be selected. The substrate is generally a plastic film or a glass plate, but is not limited thereto.

<Display device>
Next, preferred embodiments of the display device will be described in detail with reference to the drawings.
(Display Device According to Fourth Embodiment)
FIG. 1 is a schematic cross-sectional view showing a display device according to a fourth embodiment. Here, as an example of the embodiment, a configuration of an optical writing type liquid crystal display device using cholesteric liquid crystal microcapsules will be described.

The display device according to the fourth embodiment includes a photoconductor layer 13 containing an electrode 2, a light absorbing layer 3, a first charge generation 4, a charge transport layer 5, and a second charge generation layer 6 on a substrate 1. The separator 7, the adhesive layer 8, the liquid crystal display layer 9 including the liquid crystal microcapsules 12 and the transparent resin 14, the transparent electrode 10, and the transparent substrate 11 are sequentially stacked. Further, a voltage application unit is connected to the electrode 2 and the transparent electrode 10.
A driving voltage is applied to the photoconductor layer 13 in a region sandwiched between the transparent electrode 10 and the electrode 2 in synchronization with the irradiation of the image-like exposure pattern from the transparent substrate 11 to the substrate 1. Then, an image is formed on the liquid crystal display layer 9 when the applied voltage is removed.

The operation principle of the display device according to the fourth embodiment is as follows.
The photoconductor layer 13 is irradiated with light in the direction from the transparent substrate 11 to the substrate 1, and a driving voltage is applied thereto. The liquid crystal display layer 9 is applied with a drive voltage divided by the liquid crystal display layer 9, the adhesive layer 8, the isolation layer 7, the photoconductor layer 13, and the light absorption layer 3.
At this time, the electrical resistance of the photoconductor layer 13 varies depending on the intensity of exposure. Therefore, when the exposure intensity is high, the electrical resistance is low, and the voltage applied to the liquid crystal display layer 9 is high. On the other hand, when the exposure intensity is low, the electrical resistance increases and the voltage applied to the liquid crystal display layer 9 decreases. The phase of the liquid crystal changes depending on the magnitude of this voltage, and the magnitude of the reflectance is generated. Since the cholesteric liquid crystal exhibits a memory property of display, the magnitude of the reflectance caused by the phase change remains in the form of an exposure image even after exposure and voltage removal.

The display device and the manufacturing method thereof described above will be described in detail.
As the substrate 1, in addition to the materials shown in the transparent substrate 11 described later, materials such as resin, glass, and ceramics that do not transmit light can be used.

  As a material for the electrode 2, a material such as a metal that does not transmit light, carbon black, or the like can be used in addition to the material shown in the transparent electrode 10 described later. In the situation where the thickness of the electrode 2 is sufficiently large, the external force applied to the display layer is dispersed, and no obstacle due to the destruction of the capsule is observed, the substrate 1 can be regarded as common with the electrode 2 or can be omitted.

The light absorption layer 3 is provided for the purpose of absorbing the transmitted light from the liquid crystal display layer 9. It is preferable that the wavelength range that needs to be absorbed exhibits the light shielding performance in the entire visible wavelength range, particularly in the region of the wavelength of 400 nm to 700 nm. As the light shielding performance, the optical density of transmitted light is preferably 0.5 or more, and more preferably 1 or more.
For the light absorption layer 3, the insulating light-shielding film according to the third embodiment described above is used. As a method for forming the light absorbing layer 3, printing methods such as screen printing, letterpress printing, intaglio printing, flat plate printing, flexographic printing, spin coating method, bar coating method, dip coating method, roll coating method, knife coating method, A coating method such as a die coating method can be used.

For the light absorption layer 3, the insulating light shielding film according to the third embodiment may be used alone, or may be used in combination with other black materials. The black material when used in a mixed manner is not particularly limited, and organic pigments such as carbon black and aniline black, CuO, MnO, Cr ₂ O ₃ , Fe—Cr pigments, Cu—Fe—Mn And black paint in which a black pigment such as an inorganic pigment such as a pigment is dispersed in a resin binder. The black paint can be used by mixing and applying the light-shielding paint composition according to the first or second embodiment. Examples of the resin binder include polyvinyl alcohol resin, nylon resin, gelatin, acrylic resin, epoxy resin, polyester resin, and polyurethane resin.

Examples of the charge generation material used for the first charge generation layer 4 and the second charge generation layer 6 include inorganic materials such as a-Si, ZnS, ZnO, CdS, CdSe, Se, SeTe, TiO, and metal or metal-free phthalocyanine. Organic materials such as azo compounds such as bis and tris, polycyclic quinone compounds, indigo pigments, quinacridone pigments, perylene compounds, squalium compounds, azulenium compounds, cyanine dyes, pyrylium compounds, pyropyrrole dyes, condensed aromatic pigments, xanthene pigments Can be mentioned.
As a method for forming the charge generation layer, in addition to a dry film formation method such as a vacuum deposition method, a sputtering method, an ion plating method, and a CVD method, a coating solution containing the charge generation material can be applied by a bar coating method, a spin coating method, a roll The film can also be formed by a wet film forming method such as a coating method, a dip method, or a casting method. When the coating solution is used, the concentration of the charge generating material in the coating solution is preferably 1% by mass or more and 20% by mass or less, and more preferably 1.5% by mass or more and 5% by mass or less. More preferred.

The coating solution preferably contains a binder resin. As this binder resin, a known resin usually used for forming a photosensitive layer of an electrophotographic photosensitive member can be used. Specific examples include polycarbonate, polyarylate, polyethylene, polypropylene, polyester, polyvinyl acetate, polyvinyl butyral, polymers such as acrylic, methacryl, vinyl chloride, and vinyl acetate, and insulating resins such as copolymers thereof. It is done. These binder resins may be used alone or in combination of two or more.
The solvent for preparing the coating solution is a solvent that dissolves the binder resin. For example, alcohols such as methanol, ethanol, n-propanol, i-propanol, n-butanol, and benzyl alcohol, acetone, methyl ethyl ketone, Ketones such as cyclohexanone, amides such as dimethylformamide and dimethylacetamide, sulfoxides such as dimethyl sulfoxide, cyclic or chain ethers such as tetrahydrofuran, dioxane, diethyl ether, methyl cellosolve, ethyl cellosolve, methyl acetate, ethyl acetate , Esters such as n-butyl acetate, aliphatic halogenated hydrocarbons such as methylene chloride, chloroform, carbon tetrachloride, chloroethylene and trichloroethylene, mineral oil such as ligroin, benzene, toluene, Aromatic hydrocarbons such as cyclohexylene, chlorobenzene, aromatic halogenated hydrocarbons such as dichlorobenzene and the like.
The thickness of the first charge generation layer 4 and the second charge generation layer 6 is preferably 10 nm or more and 1 μm or less, and more preferably 20 nm or more and 500 nm or less. When the thickness is 10 nm or more, a high photosensitivity can be obtained and a film with little difference in film thickness can be produced. Moreover, by being 1 micrometer or less, photosensitivity is not saturated and peeling by the stress in a film | membrane is suppressed.

As a charge transport material used for the charge transport layer 5, as a hole transport material, carbazole, triazole, oxadiazole, imidazole, pyrazoline, benzylamino hydrazone, quinoline hydrazone, stilbene, triphenyl are used. Examples include amine, triphenylmethane, nitrofluorenone, trinitrofluorene, and benzidine. Examples of the electron transport material include quinone series, tetracyanoquinodimethane series, fluorene series, xanthone series, and benzophenone series. This known charge transporting material can be contained in a binder resin and formed into a film by a spin coating method, a dip method or the like.
As the binder resin used for the charge transport layer 5, the binder resin used for the first charge generation layer 4 and the second charge generation layer 6 can be used. The concentration of the charge transport material in the coating solution is preferably used in the range of 5% by mass to 50% by mass, and more preferably 10% by mass to 20% by mass.

  In addition, the photoconductor layer 13 should just be what changes an impedance according to irradiation light quantity. For example, a structure in which a charge generation layer is further formed in the charge transport layer (for example, a structure of a first charge generation layer / a first charge transport layer / a third charge generation layer / a second charge transport layer / a second charge generation layer) ) Or the above-described function-separated photoconductor layer, it may be a single-layer photoconductor layer using an integrated organic photosensitive material in which a charge generation material and a charge transport material are mixed. Absent.

For the isolation layer 7, a water-soluble resin, a water / organic solvent-soluble resin, an aqueous emulsion, dispersion, latex, or the like can be used. Examples of water-soluble resins include polyvinyl alcohol, alkyl cellulose such as methylcellulose / ethylcellulose, carboxymethylcellulose, hydroxymethylcellulose, hydroxypropylcellulose, polyethyleneimine, polyacrylic acid, polyacrylate, polyacrylamide such as polyacrylamide, and polyethylene oxide. , Polyvinylpyrrolidone, starch, casein, glue, gelatin, gum arabic, guar gum, alginate, locust bean gum, carrageenan, tamarind, pectin, and other hydrophilic groups such as hydroxyl group, carboxyl group, sulfonic acid group, amino group Urethane resin, epoxy resin, acrylic resin, etc. can be used.
As the water / organic solvent-soluble resin, ethylene-vinyl alcohol copolymer, polyacrylamide, polyethyleneimine, polyvinylpyrrolidone, polyglycerin, and various resins soluble in water / organic solvent can be used.
As the water-based emulsion, dispersion, and latex, ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer, polyurethane, polyacrylate, styrene-butadiene rubber, nitrile-butadiene rubber, and the like can be used.
The isolation layer 7 has the purpose of preventing diffusion of low-molecular non-aqueous components and organic solvents contained in the adhesive, and is most preferably a water-soluble resin that does not easily swell in the organic solvent.

  As the material of the adhesive layer 8, a known adhesive such as an acrylate-based, urethane-based, cyanoacrylate-based, silicone-based, rubber-based rubber such as isoprene, or ethylene-vinyl acetate copolymer can be used. The type of adhesive is not particularly limited, such as a two-component curable type, a thermosetting type, a moisture curable type, an ultraviolet curable type, a hot melt type, and a pressure sensitive type (adhesive).

As the liquid crystal microcapsules 12 included in the liquid crystal display layer 9, microcapsules containing cholesteric liquid crystals are preferably used. As the cholesteric liquid crystal, a nematic liquid crystal mixed with a chiral agent, or a cholesteric liquid crystal having an asymmetric carbon alone and exhibiting optical activity is preferable. The cholesteric liquid crystal may be a single compound or a mixture containing a plurality of compounds that do not exhibit liquid crystallinity alone.
As a method for producing the liquid crystal microcapsule 12, various interface deposition methods such as a phase separation method, a submerged drying method, a melt dispersion cooling method, a spray drying method, a pan coating method, an air suspension coating method, a powder bed method, An interfacial reaction method such as an interfacial polymerization method, an in situ polymerization method, or a liquid curing coating method can be used. As the wall material for the microcapsules, materials such as gelatin, gelatin-gum arabic, polyvinyl alcohol, polyamide, polyurethane / polyurea, urea formaldehyde and the like can be used.

  For the transparent resin 14, a material having translucency and appropriate strength is used. As this material, an epoxy resin, an acrylic resin, a urethane resin, a polyester resin, a polyamide resin, an olefin resin, a vinyl resin, a phenol resin, a urea resin, a glass, a ceramic, or the like can be used.

  The liquid crystal display layer 9 is a composite material in which liquid crystal microcapsules 12 are dispersed in a transparent resin 14. The liquid crystal display layer 9 having this configuration has irregularities on the surface according to the particle size of the liquid crystal microcapsules 12. As a method of forming the liquid crystal display layer 9, printing methods such as screen printing, letterpress printing, intaglio printing, flat plate printing, flexographic printing, spin coating method, bar coating method, dip coating method, roll coating method, knife coating method, A coating method such as a die coating method can be used. If the liquid crystal display layer 9 is formed on the transparent electrode 10, it is not necessary to be in direct contact with the transparent electrode 10, and the display layer 9 and the transparent electrode 10 are prevented from being short-circuited to the anchor coat layer in order to improve the adhesion. For example, a display function layer may be provided within a range in which the influence on the driving voltage can be ignored, such as an insulating layer.

  A transparent material may be used for the transparent electrode 10. Here, “transparent” means a property of transmitting light for optical writing and / or visible light. Specifically, conductive transparent metal oxides such as indium tin oxide (ITO), tin oxide, and zinc oxide, metal thin films such as gold, aluminum, and copper, and transparent conductive polymers such as polypyrrole can be used. Moreover, you may serve as a board | substrate and an electrode like ITO and various metal plates. Although the thickness of the transparent electrode 10 is not specifically limited, The range of 10 nm or more and 10 micrometers or less is preferable.

  The transparent substrate 11 can be a transparent insulator sheet or film. As a material used for the transparent substrate 11, transparent resins such as polyethylene terephthalate, polycarbonate, polyethersulfone, and triacetyl cellulose, glass, ceramics, and the like can be used. When a transparent resin is used, it is desirable to additionally form a water vapor barrier layer.

  The transparent electrode 10 and the transparent substrate 11 are not particularly limited as long as they are optically transparent. However, since the photoconductor layer 13 is exposed through these, the wavelength at which the photoconductor layer 13 is sensitive is used. More preferably, it is transparent.

The display device according to the fourth embodiment can be manufactured by the following procedure.
First, the liquid crystal display layer 9 is formed on the transparent electrode 10 formed on the surface of the transparent substrate 11. The precursor of the liquid crystal display layer 9 is an aqueous mixture containing liquid crystal microcapsules 12 and a transparent resin 14, and the liquid crystal display layer 9 is formed by applying and drying the aqueous mixture on the transparent electrode 10. On the other hand, the light-absorbing layer 3 is formed by applying and drying the light-shielding coating composition according to the first or second embodiment described above to the electrode 2 formed on the surface of the substrate 1. Further, the photoconductor layer 13 is formed by sequentially laminating the first charge generation layer 4, the charge transport layer 5, and the second charge generation layer 6. Next, an aqueous resin aqueous solution is applied and dried on the photoconductor layer 13 to form the isolation layer 7, and further a two-component adhesive solution is applied and dried to sequentially form the adhesive layer 8. Finally, the display device according to the fourth embodiment is obtained by bonding the adhesive layer 8 and the display layer 9 together.

(Display Device According to Fifth Embodiment)
A display device according to the fifth embodiment, which is still another preferred mode, will be described. FIG. 2 is a schematic cross-sectional view showing a display device according to the fifth embodiment.
The display device according to the fifth embodiment is sandwiched between transparent electrodes 22 and 28 provided on the surfaces of a pair of transparent substrates 21 and 29, and includes a self-holding device including a chiral nematic liquid crystal 30 and a transparent resin 31. A type liquid crystal display layer 27, a light absorption layer 26, and a photoconductor layer 32 are laminated. The self-holding liquid crystal display layer 27, the light absorption layer 26, and the photoconductor 32 can all be laminated by applying a stock solution or laminating.
The liquid crystal display layer 27 is preferably held by a plurality of substrates with the substrate being transparent so that it can be visually confirmed from the outside. Moreover, it is preferable to form the liquid crystal display layer 27, the light absorption layer 26, and the photoconductor layer 32 on one side of one transparent substrate.

  As the transparent substrates 21 and 29 and the transparent electrodes 22 and 28, the transparent substrate 11 and the transparent electrode 10 in the display device according to the above-described fourth embodiment can be used.

For the light absorption layer 26, the insulating light-shielding film according to the third embodiment described above can be used, and the details are as described above.
Further, the light absorbing layer 26 may be the insulating light-shielding film according to the third embodiment, or may be used in combination with another black material. As the black material when used in combination, the materials listed in the display device according to the above-described fourth embodiment can be used.

  Regarding the materials used for the first charge generation layer 23, the second charge generation layer 25, and the charge transport layer 24 in the photoconductor layer 32, the first charge generation layer in the display device according to the above-described fourth embodiment is also used. 4. The materials mentioned as the second charge generation layer 6 and the charge transport layer 5 can be used.

The chiral nematic liquid crystal 30 contained in the self-holding liquid crystal display layer 27 includes Schiff base, azo, azoxy, biphenyl, terphenyl, benzoate, tolan, pyrimidine, and cyclohexanecarboxylate. Use a material obtained by adding an optically active chiral agent such as an ester derivative, a cyanobiphenyl derivative or a bisanneal derivative to a nematic liquid crystal having a positive dielectric anisotropy such as phenylcyclohexane or dioxane, or a mixture thereof. Can do.
The helical pitch of the chiral nematic liquid crystal 30 can be adjusted by the amount of the chiral agent added to the nematic liquid crystal. For example, when the display colors are to be blue, green, and red, the center wavelengths are adjusted to be in the range of 400 nm to less than 500 nm, 500 nm to less than 600 nm, and 600 nm to less than 700 nm, respectively. Further, in order to compensate for the temperature dependence of the helical pitch of the chiral nematic liquid crystal, a known technique such as adding a plurality of chiral agents having different twisting directions or opposite temperature dependences may be used.

  As a form for forming the self-holding type liquid crystal display layer 27 containing the chiral nematic liquid crystal 30 and the transparent resin 31, a PNLC (Polymer Network Liquid Crystal Crystal) including a network-like transparent resin 31 in the continuous layer of the chiral nematic liquid crystal 30 is used. ) Structure or a PDLC (Polymer Dispersed Liquid Crystal) structure in which chiral nematic liquid crystal is dispersed in the form of droplets in a polymer skeleton. For the PNLC structure and the PDLC structure, a known method for phase-separating a polymer and a liquid crystal can be used. For example, PIPS (Polymerization Induced Phase Separation) in which a polymer precursor such as acrylic, thiol, or epoxy polymer that is polymerized by heat, light, electron beam, etc. is mixed with liquid crystal and polymerized from this state to cause phase separation. Method: Emulsion method in which a liquid crystal such as polyvinyl alcohol having a low solubility of liquid crystal is mixed with liquid crystal, stirred and suspended, and the liquid crystal is dispersed in droplets in the polymer; thermoplastic polymer and liquid crystal are mixed, A TIPS (Thermal Induced Phase Separation) method in which the polymer is cooled from a heated state and phase-separated; a polymer and a liquid crystal are dissolved in a solvent such as chloroform, and the solvent is evaporated to phase-separate the polymer and the liquid crystal. (Separation) method; However, these methods are not particularly limited. When using the PIPS method, the TIPS method, or the like, it is convenient to disperse the spacer between the substrates holding the liquid crystal during phase separation in order to keep the liquid crystal layer thickness constant. The spacer may be a ball type or a cylinder type such as glass or plastic. The thickness of each display layer is preferably controlled to several μm or more and several tens of μm or less. Further, instead of the spacer, a protrusion or the like that can control the thickness of the liquid crystal layer may be formed on the surface of the material sandwiching the liquid crystal.

  Further, as the transparent resin 31, the transparent resin 14 in the display device according to the above-described fourth embodiment can be used.

  Hereinafter, the present invention will be described more specifically with reference to examples. In the examples, “parts” and “%” represent “parts by mass” and “mass%”, respectively, unless otherwise specified.

<< Production of light-shielding paint composition and insulating light-shielding film >>
Example 1
9 parts of polyvinyl alcohol having a degree of polymerization of 1700 (“Poval PVA-217EE” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 26 parts of the above-mentioned 9% aqueous solution of polyvinyl alcohol, 2.8 parts of a carbon 15% aqueous dispersion (“TBK-BC3” manufactured by Taisei Nanotech Co., Ltd.) surface-treated with 2.6 mg of humic acid salt per specific surface area, and ethanol 1. Two parts were mixed using a paint shaker to prepare a light-shielding coating composition. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 5.6 in mass ratio.
The light shielding coating composition was applied to a PET film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light shielding film.

(Example 2)
9 parts of polyvinyl alcohol having a degree of polymerization of 1700 (“Poval PVA-217EE” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 26 parts of the above-mentioned polyvinyl alcohol 9% aqueous solution, 2.8 parts of a microencapsulated carbon black 15% aqueous dispersion (Dainippon Ink Chemical Co., Ltd. “MC Black 082-E”) encapsulated in a self-water dispersible resin, and 1.2 parts of ethanol was mixed using a defoaming planetary mill to prepare a light-shielding coating composition. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 5.6 in mass ratio.
The light shielding coating composition was applied to a PET film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light shielding film.

(Example 3)
9 parts of polyvinyl alcohol having a degree of polymerization of 1700 (“Poval PVA-217EE” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 26.8 parts of the above-mentioned 9% aqueous solution of polyvinyl alcohol, 2.0 parts of a carbon 15% aqueous dispersion (“TBK-BC3” manufactured by Taisei Nanotech Co., Ltd.) surface-treated with 2.6 mg of humic acid salt per specific surface area, and ethanol 1.2 parts were mixed using a defoaming planetary mill to prepare a light-shielding coating composition. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 8.0 by mass ratio.
The light shielding coating composition was applied to a PET film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light shielding film.

Example 4
9 parts of polyvinyl alcohol having a polymerization degree of 1700 (“Exeval RS-1717” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 26 parts of the above-mentioned 9% aqueous solution of polyvinyl alcohol, 2.8 parts of a carbon 15% aqueous dispersion (“TBK-BC3” manufactured by Taisei Nanotech Co., Ltd.) surface-treated with 2.6 mg of humic acid salt per specific surface area, and ethanol 1. Two parts were mixed using a paint shaker to prepare a light-shielding coating composition. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 5.6 in mass ratio.
The light shielding coating composition was applied to a PET film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light shielding film.

(Example 5)
9 parts of polyvinyl alcohol having a polymerization degree of 1300 (“Exeval RS-1713” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 26 parts of the above-mentioned 9% aqueous solution of polyvinyl alcohol, 2.8 parts of a carbon 15% aqueous dispersion (“TBK-BC3” manufactured by Taisei Nanotech Co., Ltd.) surface-treated with 2.6 mg of humic acid salt per specific surface area, and ethanol 1. Two parts were mixed using a paint shaker to prepare a light-shielding coating composition. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 5.6 in mass ratio.
The light shielding coating composition was applied to a PET film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light shielding film.

(Example 6)
9 parts of polyvinyl alcohol having a polymerization degree of 1300 (“Exeval RS-1713” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 26.8 parts of the above-mentioned 9% aqueous solution of polyvinyl alcohol, 2.0 parts of a carbon 15% aqueous dispersion (“TBK-BC3” manufactured by Taisei Nanotech Co., Ltd.) surface-treated with 2.6 mg of humic acid salt per specific surface area, and ethanol 1.2 parts were mixed using a paint shaker to prepare a shading coating composition. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 8.0 by mass ratio.
The light-shielding coating composition was applied to a transparent polyester film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light-shielding film.

(Example 7)
A light-shielding coating composition was prepared by the method described in Example 1 except that the polyvinyl alcohol used in Example 1 was changed to polyvinyl alcohol having a polymerization degree of 1000 (“Poval 210” manufactured by Kuraray Co., Ltd.). A light shielding film was obtained.

(Example 8)
A light-shielding coating composition was prepared by the method described in Example 1 except that the polyvinyl alcohol used in Example 1 was changed to polyvinyl alcohol having a polymerization degree of 2400 (“Poval 224E” manufactured by Kuraray Co., Ltd.). A light shielding film was obtained.

Example 9
A light-shielding coating composition was prepared by the method described in Example 1 except that the polyvinyl alcohol used in Example 1 was changed to polyvinyl alcohol having a polymerization degree of 2000 (“Kovale PVA-220”). An insulating light shielding film was obtained.

(Example 10)
In Example 1, except that the content of polyvinyl alcohol (Poval PVA-217EE) 9% aqueous solution was changed to 20 parts and the content of carbon 15% aqueous dispersion (TBK-BC3) was changed to 3.3 parts. A light-shielding coating composition was prepared by the method described in Example 1, and an insulating light-shielding film was obtained. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 3.6 in terms of mass ratio.

(Example 11)
In Example 1, except that the content of polyvinyl alcohol (Poval PVA-217EE) 9% aqueous solution was changed to 35 parts and the content of carbon 15% aqueous dispersion (TBK-BC3) was changed to 2.2 parts. A light-shielding coating composition was prepared by the method described in Example 1, and an insulating light-shielding film was obtained. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 9.5 in mass ratio.

(Comparative Example 1)
9 parts of polyvinyl alcohol having a degree of polymerization of 1700 (“Poval PVA-217EE” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. Using a defoaming planetary mill, 28.3 parts of the above-mentioned 9% aqueous polyvinyl alcohol solution, 0.5 part of carbon 20% aqueous dispersion (“Aqua-Black 162” manufactured by Tokai Carbon Co., Ltd.) and 1.2 parts of ethanol are used. The mixture was mixed to prepare a light-shielding coating composition. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 25.5 in mass ratio.
The light-shielding coating composition was applied to a transparent polyester film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light-shielding film.

(Comparative Example 2)
9 parts of polyvinyl alcohol having a degree of polymerization of 1700 (“Poval PVA-217EE” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 24 parts of the above-mentioned polyvinyl alcohol 9% aqueous solution, 5 parts of carbon 20% aqueous dispersion (“Aqua-Black 162” manufactured by Tokai Carbon Co., Ltd.), and 1 part of ethanol are mixed using a defoaming planetary mill to produce a light-shielding coating composition. A product was prepared. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 2.2 by mass ratio.
The light-shielding coating composition was applied to a transparent polyester film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light-shielding film.

(Comparative Example 3)
9 parts of polyvinyl alcohol having a polymerization degree of 1300 (“Exeval RS-1713” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 24 parts of the above-mentioned polyvinyl alcohol 9% aqueous solution, carbon dioxide 20% aqueous dispersion (Orient Chemical Industries “BONJET BLACK CW-1”) 5 parts, and ethanol 1 part were mixed using a paint shaker, and a light-shielding paint A composition was prepared. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 2.2 by mass ratio.
The light-shielding coating composition was applied to a transparent polyester film using a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light-shielding film.

(Comparative Example 4)
A light-shielding coating composition was prepared by changing the carbon 15% aqueous dispersion (TBK-BC3) used in Example 1 to carbon black ("Mitsubishi Carbon Black # 25" manufactured by Mitsubishi Chemical Corporation). Specifically, 9 parts of polyvinyl alcohol having a polymerization degree of 1700 (“Poval PVA-217EE” manufactured by Kuraray Co., Ltd.) was dissolved by heating in 91 parts of pure water to obtain a 9% aqueous solution of polyvinyl alcohol. 26 parts of the above-mentioned polyvinyl alcohol 9% aqueous solution, 0.4 part of Mitsubishi carbon black, 1.2 parts of ethanol, and 2.4 parts of pure water were mixed and dispersed using a paint shaker to prepare a light-shielding coating composition. The mixing ratio of the carbon black and the water-soluble resin (PVA) was 1: 5.8 by mass ratio.
The light-shielding paint was applied onto a PET film with a wire bar so that the film thickness after drying was 3 μm, and dried at 100 ° C. for 1 hour to obtain an insulating light-shielding film.

(Comparative Example 5)
A light-shielding coating composition was prepared by the method described in Example 1 except that the polyvinyl alcohol used in Example 1 was changed to a polyvinyl alcohol having a polymerization degree of 300 ("Poval PVA-203" manufactured by Kuraray Co., Ltd.) An insulating light shielding film was obtained.

(Comparative Example 6)
In Example 1, except that the content of the polyvinyl alcohol (Poval PVA-217EE) 9% aqueous solution was changed to 24 parts and the content of the carbon 15% aqueous dispersion (TBK-BC3) was changed to 6 parts, Example 1 A light-shielding coating composition was prepared by the method described in 1. and an insulating light-shielding film was obtained. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 2.4 by mass ratio.

(Comparative Example 7)
In Example 1, except that the content of polyvinyl alcohol (Poval PVA-217EE) 9% aqueous solution was changed to 28 parts and the content of carbon 15% aqueous dispersion (TBK-BC3) was changed to 1.0 part. A light-shielding coating composition was prepared by the method described in Example 1, and an insulating light-shielding film was obtained. In addition, the content ratio of the carbon black and the water-soluble resin (PVA) was 1: 16.8 in mass ratio.

[Evaluation]
(1) Measurement of light transmittance With respect to the insulating light-shielding films obtained by the examples and comparative examples described above, light transmittance in a wavelength region of 400 nm or more and 800 nm or less is measured using Hitachi U-4000, Spectrophotometer. (%) Was measured. The results are shown in Table 1.

(2) Measurement of surface electric resistance value With respect to the insulating light-shielding films obtained by the above examples and comparative examples, the surface electric resistance value (Ω / □) was measured using R8340A, URTRA HIGH RESISTANCE METER manufactured by ADVANTEST. It was measured. The results are shown in Table 1.

  From the results of Table 1, the insulating light-shielding film for display devices formed using the water-based light-shielding coating composition for display devices in Examples has high light-shielding properties and high surface electrical resistance (that is, high insulating properties). You can see that

≪Production of display device≫
(Example 12)
A first charge generation layer was formed on the ITO film of a polyethylene terephthalate (PET) substrate (thickness: 125 μm) on which an ITO film (thickness: 800 mm) was formed as an electrode layer. Specifically, first, hydroxygallium phthalocyanine (X-ray diffraction spectrum Bragg angle (2θ ± 0.2 ° C) is 7.0 °, 7.5 °, 10.5 °, 11.7 °, 12.7). Having a strong diffraction peak at 17.3 °, 18.1 °, 24.5 °, 26.2 °, and 27.1 °), and using polyvinyl butyral as the binder resin, and its mass The ratio was 1: 1 and dispersed with butanol to prepare a 4% dispersion (coating solution A). This was applied onto the ITO film by spin coating, and then dried to form a first charge generation layer having a thickness of 0.2 μm.
Furthermore, a charge transport layer was formed on the first charge generation layer. Specifically, first, a charge transport material having a structure represented by the following exemplary compound (VI), and polycarbonate {bisphenol-Z, (poly (4,4′-cyclohexylidene diphenylene carbonate))} as a binder resin, The former was mixed at 40% and the latter at 60%. Thereafter, it was dissolved in monochlorobenzene to prepare a 10% solution (coating solution B). This was pulled up at a rate of 120 mm / min by a dip coating method to form a charge transport layer having a thickness of 3.0 μm on the first charge generation layer.
Further, the coating solution A was applied onto the charge transport layer by a spin coating method and dried to form a second charge generation layer having a thickness of 0.2 μm.
A photoconductor layer was formed as described above. On the photoconductor layer, a 3% aqueous solution of polyvinyl alcohol was applied by spin coating to form an isolation layer having a thickness of 0.2 μm. Next, the light-shielding coating composition prepared in Example 1 was applied by spin coating on the surface of the PET film on which the isolation layer was formed on the photoconductor layer, and then dried to obtain a light having a thickness of 3 μm. An absorbent layer was formed. Thereafter, Dick Dry (Dainippon Ink & Chemicals, WS-321A / LD-55), which is a completely aqueous dry laminate adhesive, was applied and dried to form an adhesive layer having a thickness of 4.0 μm.

On the other hand, a liquid crystal display layer, a transparent electrode layer, and a transparent substrate containing liquid crystal microcapsules were formed as follows. 74.8 parts of nematic liquid crystal E8 (manufactured by Merck) having positive dielectric anisotropy, 21 parts of chiral agent CB15 (manufactured by BDH), and 4.2 parts of chiral agent R1011 (manufactured by Merck) are dissolved by heating. Then, it was cooled to room temperature (25 ° C.) to obtain a chiral nematic liquid crystal that selectively reflects blue-green color light. To 10 parts of this blue-green chiral nematic liquid crystal, 3 parts of an adduct of 3 mol of xylene diisocyanate and 1 mol of trimethylolpropane (D-110N, manufactured by Takeda Pharmaceutical Co., Ltd.) and 100 parts of ethyl acetate are added to form a solution, which becomes an oil phase. A liquid was prepared.
On the other hand, 10 parts of polyvinyl alcohol (manufactured by Kuraray Co., Ltd., Poval 217EE) was added to 1000 parts of heated ion-exchanged water, stirred, and then allowed to cool to prepare a liquid that became an aqueous phase.
Next, an oil-in-water emulsion in which 10 parts of the oil phase was emulsified and dispersed in 100 parts of the aqueous phase for 1 minute by a household mixer to which 30 V AC was applied by a slidac was prepared. The oil-in-water emulsion was stirred for 2 hours while being heated in a water bath at 60 ° C. to complete the interfacial polymerization to form liquid crystal microcapsules. It was 12 micrometers when the average particle diameter of the obtained liquid crystal microcapsule was measured with the laser particle size distribution meter. The obtained liquid crystal microcapsule dispersion was filtered through a stainless steel mesh having a mesh size of 38 μm, and then left overnight, and the milky white supernatant was removed to obtain a slurry of 40% solid component containing liquid crystal microcapsules. A coating solution C was prepared by adding a 10% solution containing polyvinyl alcohol in an amount of 2/3 to the mass of the solid content to the obtained slurry.
By applying the coating solution C with a # 44 wire bar on the ITO film surface of a PET film (Torayheim, transparent substrate, plate thickness 125 μm) with an ITO film (transparent electrode layer, thickness 800 mm). A liquid crystal display layer containing microcapsules was formed.

  The adhesive layer formed on the photoconductor layer and the light absorption layer and the liquid crystal display layer were brought into close contact with each other and laminated at 70 ° C. to produce a monochrome display photo-writing type liquid crystal display device. .

(Example 13)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Example 2 was used for producing the light absorption layer.

(Example 14)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Example 3 was used for producing the light absorption layer.

(Example 15)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Example 4 was used for producing the light absorption layer.

(Example 16)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Example 7 was used for the production of the light absorption layer.

(Example 17)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Example 8 was used for the production of the light absorption layer.

(Example 18)
In Example 12, a monochromatic display optical writable liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Example 10 was used for producing the light absorption layer.

(Example 19)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Example 11 was used for the production of the light absorption layer.

(Comparative Example 8)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Comparative Example 1 was used for producing the light absorption layer.

(Comparative Example 9)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Comparative Example 2 was used for producing the light absorption layer.

(Comparative Example 10)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Comparative Example 4 was used for producing the light absorption layer.

(Comparative Example 11)
In Example 12, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Comparative Example 5 was used for producing the light absorption layer.

(Comparative Example 12)
In Example 12, a monochromatic display optical writing type liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Comparative Example 6 was used for producing the light absorption layer.

(Comparative Example 13)
In Example 12, a monochromatic display optical writable liquid crystal display device was produced by the method described in Example 12 except that the light-shielding coating composition prepared in Comparative Example 7 was used for producing the light absorption layer.

(Example 20)
After applying the light-shielding coating composition prepared in Example 1 on the ITO film of a polyethylene terephthalate (PET) substrate (thickness: 125 μm) on which an ITO film (thickness: 800 mm) is formed as an electrode layer by spin coating. Then, a light absorption layer having a film thickness of 3 μm was formed.
Next, a first charge generation layer was formed on the light absorption layer. Specifically, first, hydroxygallium phthalocyanine (X-ray diffraction spectrum Bragg angle (2θ ± 0.2 ° C) is 7.0 °, 7.5 °, 10.5 °, 11.7 °, 12.7). Having a strong diffraction peak at 17.3 °, 18.1 °, 24.5 °, 26.2 °, and 27.1 °), and using polyvinyl butyral as the binder resin, and its mass The ratio was 1: 1 and dispersed with butanol to prepare a 4% dispersion (coating solution A). This was applied onto the light absorption layer by spin coating, and then dried to form a first charge generation layer having a thickness of 0.2 μm.
Furthermore, a charge transport layer was formed on the first charge generation layer. Specifically, first, a charge transport material having a structure represented by the exemplary compound (VI), and polycarbonate {bisphenol-Z, (poly (4,4′-cyclohexylidene diphenylene carbonate))} as a binder resin, The former was mixed at 40% and the latter at 60%. Thereafter, it was dissolved in monochlorobenzene to prepare a 10% solution (coating solution B). This was pulled up at a rate of 120 mm / min by a dip coating method to form a charge transport layer having a thickness of 3.0 μm on the first charge generation layer.
Further, the coating solution A was applied onto the charge transport layer by a spin coating method and dried to form a second charge generation layer having a thickness of 0.2 μm.
As described above, a photoconductor layer was formed on the light absorption layer. Further, an aqueous solution of 3% polyvinyl alcohol was applied on the photoconductor layer by a spin coating method to form an isolation layer having a thickness of 0.2 μm. Next, Dic Dry (Dai Nippon Ink Chemical Co., Ltd., WS-321A / LD-55), which is a completely water-based dry laminate adhesive, is formed on the surface of the PET film in which the isolation layer is formed on the photoconductor layer. ) Was applied and dried to form an adhesive layer having a thickness of 4.0 μm.

On the other hand, a liquid crystal display layer containing liquid crystal microcapsules was produced by the method described in Example 12.
The adhesive layer formed on the light absorption layer and the photoconductor layer and the liquid crystal display layer were brought into close contact with each other and laminated at 70 ° C. to produce a monochrome display photo-writing type liquid crystal display device. .

(Example 21)
In Example 20, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 20 except that the light-shielding coating composition prepared in Example 2 was used for producing the light absorption layer.

(Comparative Example 14)
In Example 20, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 20 except that the light-shielding coating composition prepared in Comparative Example 1 was used for producing the light absorption layer.

(Comparative Example 15)
In Example 20, a monochrome display photo-writing type liquid crystal display device was produced by the method described in Example 20 except that the light-shielding coating composition prepared in Comparative Example 3 was used for producing the light absorption layer.

[Evaluation test]
(3) Sensitivity For the liquid crystal display devices of Examples 12 to 21 and Comparative Examples 8 to 15 obtained as described above, an optical writing device including a connector, a voltage applying unit, an optical writing unit, and a control unit is provided. Used to write an image. Specifically, first, two transparent electrode layers in the optical writing type liquid crystal display device of each example and comparative example were connected to a connector. Further, in order to input an image to an optical writing type liquid crystal display device, an optical writing means composed of a monochrome liquid crystal panel is brought into close contact, and image-like light is irradiated. An AC voltage of 300 Vpp (in the comparative example) was applied. At this time, as the image-like light by the light writing means, the light intensity of the light irradiation part is increased from 50 μW / cm ² by 50 μW / cm ^2, and the light intensity at which a blue monochrome image is obtained in the light irradiation part is confirmed. did.

As a result, in Examples 12 to 19, in the dark area (1μW / cm ²⁾ and the light irradiation unit (200μW / cm ^2), the light irradiation unit is blue, dark portions black monochrome image is obtained, it is highly sensitive It was verified that In Examples 20 and 21, in the dark area (1μW / cm ²⁾ and the light irradiation unit (400μW / cm ^2), the light irradiation unit is blue, dark portions black monochrome image is obtained, it is excellent in sensitivity It was verified.
On the other hand, in Comparative Examples 8, 13, and 14, in order to obtain a monochrome image in which the light irradiation part is blue and the dark part is black, the light irradiation of the dark part (1 μW / cm ² ) and the light irradiation part (1 mW / cm ² ) is performed. It was necessary, and it was verified that the sensitivity was inferior to those in the above examples. In Comparative Examples 9, 10, 11, 12, and 15, no image was obtained.

(4) Durability The above image writing operation was repeated 250 times at the maximum with the light intensity of the dark part and the light irradiation part where the image was obtained, respectively, and the durability of the image recording was confirmed.
As a result, in Examples 12 to 19, it was possible to suppress color unevenness due to unerased residue up to 200 times, and in Examples 20 and 21, it was possible to suppress color unevenness due to unerased residue up to 250 times. On the other hand, in Comparative Examples 8, 13, and 14, color unevenness due to unerasing occurred after 100 times.

It is a schematic sectional drawing which shows the display device which concerns on 4th Embodiment. It is a schematic sectional drawing which shows the display device which concerns on 5th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Electrode 3 Light absorption layer 4 1st charge generation layer 5 Charge transport layer 6 2nd charge generation layer 7 Separation layer 8 Adhesion layer 9 Liquid crystal display layer 10 Transparent electrode 11 Transparent substrate 12 Liquid crystal microcapsule 13 Photoconductor layer 14 Transparent resin 21, 29 Transparent substrate 22, 28 Transparent electrode 23 First charge generation layer 24 Charge transport layer 25 Second charge generation layer 26 Light absorption layer 27 Self-holding type liquid crystal display layer 30 Chiral nematic liquid crystal 31 Transparent resin 32 Photoconductor layer

Claims (18)

A carbon black whose surface is hydrophilized by at least one of the following (1) and (2), a water-soluble resin having a polymerization degree of 1000 or more and 3000 or less, and water, the carbon black and the water-soluble A water-based light-shielding coating composition for a display device, wherein a content ratio with a resin is in a range of 1: 3.6 to 1:10 by mass ratio.
(1) Surface treatment with humic acid salt
(2) It is encapsulated in a self-water dispersible resin and microencapsulated.   2. The water-based light-shielding coating composition for display devices according to claim 1, wherein the degree of polymerization of the water-soluble resin is 1000 or more and 2000 or less.   2. The water-based light-shielding coating composition for a display device according to claim 1, wherein the water-soluble resin has a polymerization degree of 1300 or more and 1800 or less.   4. The display device according to claim 1, wherein a content ratio of the carbon black and the water-soluble resin is 1: 3.6 to 1: 8 in mass ratio. Water-based shading coating composition.   The water content for a display device according to any one of claims 1 to 3, wherein a content ratio of the carbon black and the water-soluble resin is 1: 4 to 1: 6 by mass ratio. Shading paint composition.   6. The surface of the carbon black having a hydrophilic surface treated with a humic acid salt having a specific surface area of 0.6 mg to 4 mg, according to any one of claims 1 to 5. Water-based shading coating composition for display devices. The water-soluble light-shielding coating composition for display devices according to any one of claims 1 to 6 , wherein the water-soluble resin is at least one selected from polyvinyl alcohol and derivatives thereof. Carbon black whose surface has been hydrophilized by at least one of the following (1) and (2), and a water-soluble resin having a polymerization degree of 1000 or more and 3000 or less, and the carbon black and the water-soluble resin An insulating light-shielding film for a display device, wherein the content ratio is in the range of 1: 3.6 to 1:10 by mass ratio.
(1) Surface treatment with humic acid salt
(2) It is encapsulated in a self-water dispersible resin and microencapsulated. The insulating light-shielding film for a display device according to claim 8 , wherein the degree of polymerization of the water-soluble resin is 1000 or more and 2000 or less. The insulating light-shielding film for a display device according to claim 8 , wherein the degree of polymerization of the water-soluble resin is 1300 or more and 1800 or less. Content ratio of the carbon black and the water-soluble resin is 1 in weight ratio: 3.6 to 1: 8 display device according to any one of claims 8 to 10, characterized in that it is Insulating light shielding film. Content ratio of the carbon black and the water-soluble resin is in a mass ratio of 1: 4 to 1: insulating display device according to any one of claims 8 to 10, characterized in that it is 6 Light shielding film. A pair of electrodes consisting of an anode and a cathode, at least one of which is transparent or translucent, a display layer sandwiched between the electrodes, a photoconductor layer, and a light absorbing layer sandwiched between the photoconductor layer and the electrode And having
A display device comprising the insulating light-shielding film for a display device according to any one of claims 8 to 12 as the light absorption layer. A pair of electrodes consisting of an anode and a cathode, at least one of which is transparent or translucent, a display layer sandwiched between the electrodes, a photoconductor layer, and light absorption sandwiched between the display layer and the photoconductor layer And having a layer
A display device comprising the insulating light-shielding film for a display device according to any one of claims 8 to 12 as the light absorption layer. Display device according to claim 13 or claim 14 wherein the display layer is characterized in that it is a liquid crystal layer. The display device according to claim 15 , wherein the liquid crystal layer is a liquid crystal layer containing a cholesteric liquid crystal and a transparent resin. Display device according to any one of claims 13 to claim 16 wherein the photoconductive layer, characterized in that it is a layer configured to include an organic photoconductor. Display device according to any one of claims 13 to claim 17, characterized in that the said optical conductor layer and the display layer was retained by the resin substrate.