JPH0260164B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention will be explained in the following order. A Industrial application field B Summary of the invention C Prior art D Problems to be solved by the invention E Means and actions for solving the problems F Example F ₁ Example 1 Application column 1 Application example 2 F ₂ Example 2 F ₃ Example 3 F ₄ Example 4 F ₅ Example 5 F ₆ Example 6 F 7 Example 7 F ₈ Example _{8 F 9 Example} 9 F ₁₀ Example 10 F ₁₁ Example 11 F ₁₂ Example 12 F ₁₃ Example 13 G Effect of the invention A Industrial field of application The present invention relates to a method for producing a multicolored surface-colored body produced by a polymer layer formed by electrodeposition, and in particular, , relates to a method for manufacturing a multicolored surface-colored body used as a color filter for display devices such as liquid crystal displays. B. Summary of the Invention The present invention provides a method for producing a multicolored surface-colored body, in which a plurality of conductive layers are formed on a substrate and arranged insulated from each other, and then an electrodepositable layer is formed on the conductive layers. A colored layer is selectively formed by electrodeposition from a solution containing a polymer, a dye, and particles having a dielectric constant higher than that of the electrodepositable polymer, and the process is then repeated with different colored dyes. The electrical impedance of the filter layer when used as a color filter of a multicolor display device, which is one application field of multicolor surface colored bodies, is characterized by being manufactured by a simple method. The present invention provides a method for manufacturing a multicolor surface-colored body that reduces the loss of driving voltage and is suitable for a multicolor display device driven by a low voltage. C. Prior Art Multicolor surface colored bodies are often used as filters for image pickup tubes in color TV cameras, etc., but recently, one application of multicolored surface colored bodies is multicolor display in combination with displays such as liquid crystals. The device is attracting attention. FIG. 3 shows an example of a multicolor display device to which a color filter is applied as one of the application examples. Third
In the figure, 1 is a transparent substrate, 2 is a display electrode made of a transparent conductive film patterned with arbitrary figures or characters, 3 is a color filter formed in close contact with the surface of the display electrode 2, 4 is a transparent counter electrode, 5 is a transparent counter substrate. The space sandwiched between the two substrates 1 and 5 is filled with a substance, such as liquid crystal or electrochromic material, that functions as an optical shutter that opens and closes when voltage is applied, and the color filters 3, 3', 3'' are interposed therebetween. If you form it in different colors,
By selectively applying a voltage between the display electrodes 2, 2', 2'' and the counter electrode 4, multicolor display is possible. Multicolor display using a color filter is simple and easy. The practical effect is extremely large because it is easy to obtain a free color tone and can be used in combination with various display materials and methods.However, manufacturing of color filters (multicolor display devices using them) In this case, the display electrode pattern and the color filter pattern formed on the display electrode surface must be manufactured so that there is no misalignment.In particular, color graphs using fine patterns of three primary colors must be manufactured. When trying to realize an on-screen display, matching the pattern between the display pole and the color filter is an important issue that is difficult to manufacture.Additionally, changing colors to create multiple colors also complicates the process. This is a factor, especially when trying to achieve coloring by dyeing, a process called resist dyeing is added to prevent the already colored areas from being dyed twice in the next dyeing process, making it even more complicated. Furthermore, the resist dyeing technology itself is a difficult issue that must be considered individually depending on the dye.Generally, methods for creating color filters include methods such as screen printing and photolithography. Screen printing does not require resist dyeing, but there is a limit to how fine the pattern can be, and the more colors there are, the less accurate the printing position will be, resulting in misalignment with the displayed pattern. Although it is possible to create fine patterns with lithography, it is necessary to go through the photolithography process every time the color is changed, and a resist dyeing method that prevents double dyeing is required, making the process extremely complicated. Therefore, in Japanese Patent Application No. 57-233934, the present inventors developed a simple method that does not cause pattern shift even when the display pattern becomes fine and can change colors. proposed the production of color filters by electrodeposition of polymers as a method for producing color filters that does not require special resist dyeing.D Problems to be Solved by the Invention However, neither method The color filter obtained is an insulating layer, and in an actual display device, an insulator is sandwiched between the display electrode and the display material, causing a drive voltage loss equal to the voltage drop caused by the color filter, resulting in a low voltage This has not only been a hindrance to driving, but has also worsened the steepness of the threshold characteristics of liquid crystal display devices, etc., which is important in multiplex driving. Therefore, the present invention focuses mainly on the fact that the driving power source for liquid crystal display devices is pulse or alternating current, and by reducing the impedance of the color filter at the driving frequency, the present invention is suitable for low voltage driving and multiplex driving. The aim is to realize a colored object with a colored surface. E Means and effects for solving the problem As a concrete means of realization, we aim to reduce impedance by improving the dielectric constant of the color filter obtained by electrodeposition and increasing the capacitance of the color filter. Used in color filters by using a conductive thin film on a substrate as an electrode and forming a colored layer by electrodeposition from a solution containing a polymer, a dye, and particles with a dielectric constant higher than the dielectric constant of the polymer used. This is a product with a multicolored surface. According to this method, by applying a desired pattern to a conductive thin film by vapor deposition using a mask, sputtering, or etching, a voltage is applied to the polymer and the particles having a higher dielectric constant than the polymer used in the dye. It is possible to form a colored layer with low impedance and no deviation in pattern position by selectively electrodepositing on the conductive portions. Moreover, by repeating this operation, it is possible to easily create multiple colors. As long as the surface of the substrate used in this method is insulating, a conductive thin film layer with good adhesion to the substrate is selected, and there are no restrictions on its material or shape. In addition, due to the increased dielectric constant of the obtained colored layer, there is less voltage drop when AC voltage is applied.
A multicolor display device suitable for low voltage driving can be obtained. F Example Hereinafter, a method for forming a colored layer by electrodeposition of a polymer, which is an important point of the present invention, will be described. One method for electrodepositing a polymer on an electrode is to electrochemically polymerize a monomer on the electrode. As an example of this method, there is a report that a polymer film was obtained by electrochemically polymerizing various vinyl compounds on an iron plate (Metal Surface Technology Vol. 1.19, No. 12,
1968). Recently, research has also been actively conducted in which dielectric polymers such as polypyrrole and polythienylene are produced on electrodes by electrochemically polymerizing pyrrole, thiophene, and the like. However, such a method of directly electrochemically polymerizing monomers is not suitable for use in the present invention because the efficiency is still low, the obtained film is already colored, and the coloring is not arbitrary. has problems. Another method for electrodepositing polymers on electrodes is to insolubilize the polymer onto the electrode from a polymer solution.
There is a method of precipitation. One example of this is an industrially known method called electrocoating, in which a pigment is dispersed in an aqueous polymer solution, a metal is immersed, and used as an electrode, and a colored layer is electrodeposited on the metal. Used for pre-coating, etc. The principle of this method is
A hydrophilic group, such as a carboxyl group, is introduced into a polymer, and the carboxyl group is neutralized with an inorganic alkali, an organic amine, etc. to make it water-soluble. Then, when the electrode is immersed in an aqueous solution of the polymer and a voltage is applied, the carboxyl anions dissociated in the aqueous solution electrophores toward the anode and react with protons generated by water electrolysis on the electrode. As a result, the polymer becomes insolubilized and precipitates. That is, the following reaction occurs on the anode, and polymer precipitation is observed. K0001 Furthermore, if a basic group (for example, polyamine) is used as a hydrophilic group and is neutralized and made water-soluble with an acid, polymer precipitation will be observed on the cathode. Normally, in electrodeposition coating, applying a voltage of 100 to 200V will cause
Although a film thickness of ~20 μm was obtained, it is desirable that the colored layer be thinner in the color filter according to the present invention. Therefore, as will be described later in Examples, it is necessary to optimally set the resin concentration, voltage, and solvent composition. Polymers for anionic electrodeposition include adducts of natural drying oil and maleic acid, alkyd resins with carboxyl groups introduced, adducts of epoxy resins with maleic acid, polybutadiene resins with carboxyl groups, acrylic acid or methacrylic acid, and adducts of epoxy resins with maleic acid. Copolymers with esters thereof are used, and other polymers or organic compounds having functional groups may be introduced into the polymer skeleton depending on the characteristics of the electrodeposited film. When viewing light through a color filter as in the present invention,
Transparency is required for the colored layer, and acrylic or polyester polymers are suitable for this purpose.
In addition, the amount of hydrophilic functional groups such as carboxyl groups and hydroxyl groups in the polymer is important; if there are too many hydrophilic groups, the insolubilization of the electrodeposited layer will not be sufficient, resulting in an uneven film, and if there are too few, the amount of hydrophilic functional groups such as carboxyl groups and hydroxyl groups will be Water solubility becomes insufficient. Water is the main component of the polymer solvent, but isopropanol, n-butyl alcohol, t-butyl alcohol, methyl cellosolve, ethyl cellosolve, isoprobil cellosolve, butyl cellosolve, diethylene glycol methyl ether, diethylene glycol ethyl ether, diacetone alcohol Hydrophilic solvents such as, for example, are included as solvents for polymerization of polymers. The type and amount of hydrophilic solvent contained greatly affect the film thickness and uniformity of the electrodeposited layer. In electrodeposition coating, pigments are used, and the charged pigments are electrophoresed together with polymers and incorporated into the film, but in the case of a transparent color filter like the one of the present invention, most of the pigments are Transparent pigments or dyes are used because their hiding power is not required. In order to electrodeposit a dye with a polymer, it is necessary for the dye molecules to be charged and electrophoresed, but in the case of water-soluble dyes, the elusive dye ions bring about the effect of adding a supporting salt, increasing the current, This appears as an increase in film thickness and non-uniformity of the film. Pigments that are sparingly soluble or insoluble in water usually aggregate in water, but electrodeposited polymers can be regarded as a type of liquid with hydrophobic groups and hydrophilic groups, and to a certain extent, It was discovered that it exhibits a dispersion effect, and that it can be made into fine particles by combining with a suitable dispersion medium, and that it can be electrodeposited together with polymers. In this case, it is necessary to make the electrodeposition rates of the dye and the polymer comparable, but this can be controlled by the solution composition. The high dielectric constant particles used to increase the dielectric constant of the electrodeposited colored layer are similar to pigments used in electrodeposition coatings.
In the solution, they are dispersed as charged particles with adsorbed polymers, which undergo electrophoresis and are incorporated into the colored layer when a voltage is applied. The particle size and amount of high dielectric constant particles are
It greatly affects the dielectric constant and transparency of the colored layer. The table below shows an example of the dielectric constants of electrodepositable polymers and high dielectric constant particles. Substance Relative dielectric constant Electrodeposition polymer Polyester resin 3.5 Acrylic resin 2.7~3.2 Melamine resin 7.2~8.2 High dielectric constant particles TiO ₂ 60~120 MgTiO ₃ 10~30 CaTiSiO ₅ 40~80 BaTiO ₃ 500~20000 SrTiO ₃ 170 ~430 BaZrO ₃ −PbZrO ₃ 6000 BaZrO ₃ −PbSnO ₃ 6000 BaTiO ₃ −Bi ₂ (SnO ₃ ) ₃ 2000 BaTiO ₃ −NiSnO ₃ 2000 BaTiO ₃ −SrSb ₂ O ₆ 2000 BaTiO ₃ −BaSb ₂ O ₆ 2000 _BaTiO3 − PbSb ₂ O ₆ 2000 (LaNa)FeO ₃ −Bi ₂ O ₃ 12000 to 70000 Below, the method for producing a multicolor surface-colored body according to the present invention and its application to a multicolor display device will be explained based on examples. This will be explained in detail. _F1 Example 1 FIGS. 1 and 2 are examples of a multicolor display device to which the method of manufacturing a multicolor surface colored body according to the present invention is applied. Hereinafter, the method for manufacturing a multicolored surface colored body according to the present invention will be specifically described. Patterning step 6 is a display substrate made of a transparent material, and a tin oxide transparent conductive film is formed on the display substrate by a spray coating method. The transparent conductive film is patterned into stripes by etching to obtain display electrodes 7. Electrodeposition process Next, using a paint with the following composition (ESVIA ED-3000 manufactured by Shinto Paint Co., Ltd.) SVIER ED-3000 aqueous polyester resin water-soluble melamine resin 70wt% butyl cellosolve ethyl cellosol n-butanol 30wt%, the following composition was electrodeposited. make a bath

[Table] It is desirable that the organic pigment used has very good light resistance. For example, phthalocyanine blue, phthalocyanine green, azo metal complex salts, etc. can be used. The procedure for making the bath is to add titanium oxide powder and red organic pigment to Esbia ED-3000 and disperse with a pigment dispersion machine to obtain a paste. Add water to the paste and stir to form a well-mixed solution. At this time, if the pigment weight ratio x is too large, uniform mixing cannot be obtained, so it is arbitrarily selected within a range that does not exceed the upper limit. In this case, a suitable dispersant may be added to improve the dispersibility of the pigment. The display electrode 7 was placed in the electrodeposition bath prepared as described above.
The display substrate 6 on which is formed is immersed. Among the display electrodes 7 patterned in stripes, electrodes to be colored in the same color are selected, and a voltage of 20 V is applied for 3 minutes using the selected electrodes as anodes. After energizing,
The display substrate 6 is pulled up and thoroughly washed with water to wash away the solution adhering to the areas to which no voltage is applied. After washing with water and drying, a highly transparent colored layer is formed on the electrode to which voltage has been applied. Curing Step Next, the polyester resin and melamine resin in the colored layer formed by electrodeposition are baked to undergo a condensation reaction and cured. Baking in air at 175℃
After 30 minutes, the colored layer will be completely cured. Since the hardened colored layer will not be dyed twice even if it is immersed in the electrodeposition bath again, for the formation of the colored layer for the second time onwards, select another display electrode of the same color and use a different one. This is achieved by repeating the process of electrodeposition and curing in an electrodeposition bath in which colored dyes are dispersed. In this example, a striped color filter 8 with a width of 200 μm in the order of red, blue, and green is formed in a patterning process → red electrode electrodeposition process → curing process → blue electrode electrodeposition process → curing process → green electrode electrodeposition process. It was manufactured with a film layer of 1 μm using a deposition process followed by a curing process, which was extremely simple. The obtained color filter showed no color shift, was uniform, and had properties that were not easily attacked by acids, alkalis, various organic solvents, hot water, and the like. Furthermore, the metal complex dye used was extremely stable in the colored layer, and even after 360 hours of carbon arc testing, it exhibited a value of 95% or more of the initial light absorption rate, and had excellent light resistance. Application examples of the multicolor display device using the multicolor surface colored body according to the present invention will be shown below. (Application example 1) The color filter 8 is formed on the display electrode 7 by the method described above, and the display substrate 6 is connected to a transparent counter substrate 10 on which transparent counter electrodes 9 are formed in a stripe shape, with spacers 11 interposed therebetween. The display electrode 7 and the counter electrode 9 are integrated so that their stripes intersect at right angles to form a cell. The cell was filled with TN-FEM liquid crystal as the display material 12 to produce a multicolor liquid crystal display device. In this case, a voltage is applied between the display electrode 7 and the counter electrode 9, the cell is sandwiched between a polarizer and an analyzer whose transmission axes are parallel, and when viewed from the direction of the display substrate 6 or the counter substrate 10, the cell is transparent. The color of the color filter 8 is displayed, and becomes black when the voltage application is stopped. When light is irradiated from the direction of the counter substrate 10, the color of the color filter 8 is displayed more effectively because the cell has good transparency. Moreover, since the color filter layer contains high dielectric constant particles, the voltage-transmittance characteristic (curve 1) in the electro-optical characteristics of the multicolor display device of this example is different from that of the conventional electrodeposition, as shown in FIG. The voltage was shifted to a lower voltage side than that using a color filter (curve 2), and was close to the voltage-transmittance characteristic (curve 3) of the liquid crystal material itself used. In this way, the multicolor display device using the multicolor surface-colored body of this example can obtain a color filter with a fine pattern without deteriorating the display quality, and is reliable, despite the simple manufacturing method. It has become clear that the present invention is suitable for providing a color graphic display device driven by a low voltage matrix with high performance. (Application Example 2) The display material 12 in Application Example 1 is a negative type guest host liquid crystal using a black dichroic dye, and the display substrate 6 is a white material (white ceramic). Created a display device.
In this case, a voltage is applied between the display electrode 7 and the counter electrode 9, and when viewed from the direction of the transparent counter substrate 10 through the polarizing plate, the color of the color filter 8 is displayed brightly, and when the voltage application is stopped, the color of the color filter 8 is bright. The color is black, which is the color of the dichroic pigment. In this example as well, the same effects as in Application Series 1 were obtained. _F2 Example 2 The electrodeposition bath in Example 1 was used as a paint with the following composition (Powermite 3000-10, manufactured by Nippon Paint), Powermite 3000-10 water-soluble acrylic resin water-soluble melamine resin 60wt% butyl cellosolve isopropyl alcohol 40wt% , prepare an electrodeposition bath with the following composition.

[Table] Commercially available disperse dyes often contain anionic dispersants, which become ions in the bath and cause an increase in current value. Preferably one that does not contain agents. To prepare the bath, first add Powermite 3000-10 barium titanate powder and disperse it with a pigment dispersion machine to make a paste. Add water to the paste and stir to mix to form a solution. Next, add disperse dye x<1.5
Uniformly dispersed in ethylene glycol within the range of
Add to solution and mix. Hereinafter, in the same manner as in Example 1, a multicolor surface colored body was created and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. but,
It has become clear that only a limited number of dyes have excellent light fastness properties for color filters. _F3 Example 3 The electrodeposition bath in Example 1 had the following composition.

[Table] The method for preparing the bath in this case is to add magnesium titanate powder from Sspier ED-3000, then add an oil-soluble dye in the range of x<1.0, and mix with a pigment dispersion machine to make a paste. Next, water was added to the paste and stirred and mixed to form an electrodeposition bath. Below, Example 1
A multicolor surface-colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. It goes without saying that the oil-soluble dye used in this example is preferably a dye that is soluble in a hydrophilic solvent and has excellent light resistance. _F4 Example 4 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. _F5 Example 5 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor display device was created in the same manner as in Example 1, and when a multicolor display device was created using this, the same effects as in Example 1 were obtained. _F6 Example 6 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. _F7 Example 7 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. _F8 Example 8 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. _F9 Example 9 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. _F10 Example 10 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. _F11 Example 11 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. _F12 Example 12 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. F ₁₃ Example 13 The electrodeposition bath in Example 1 had the following composition.

[Table] Hereinafter, a multicolor surface colored body was created in the same manner as in Example 1, and a multicolor display device was created using this, and the same effects as in Example 1 were obtained. G. Effects of the Invention As specifically described in the examples above, the method for producing a multicolored surface colored body according to the present invention is simple,
Color filters can be manufactured without using special means such as resist dyeing to separate colors for multicolorization. Furthermore, the color filter is robust and has no pattern deviation, and can achieve high display quality and reliability even when combined with display materials such as liquid crystal. Furthermore, since the alternating current impedance is reduced due to the high dielectric constant of the color filter, the effect is particularly great when applied to a multicolor display device driven by a low voltage with little loss of alternating driving voltage.

[Brief explanation of drawings]

1 and 2 are a cross-sectional view and a plan view of a multicolor display device using a multicolor surface-colored body according to the present invention, and FIG. 3 is a cross-sectional view showing a multicolor display device using a multicolor surface-colored body according to the present invention. 4 are graphs showing the electro-optical characteristics of a multicolor display device to which the multicolor surface colored body according to the present invention is applied. 1, 6... display substrate, 2, 7... display electrode,
3, 8... Color filter, 4, 9... Counter electrode, 5, 10... Counter substrate, 12... Display material.

Claims (1)

[Claims] 1. In a method for manufacturing a multicolored surface-colored body, a plurality of conductive layers arranged insulated from each other are formed on a substrate, and then electrodeposition is performed on the conductive layers. A colored layer is selectively formed by electrodeposition from a solution containing a colored polymer, a dye, and particles having a dielectric constant higher than that of the electrodepositable polymer, and the subsequent operation is performed using a dye of a different color. A method for producing a multicolored surface-colored body, characterized in that it is produced by repeating the process. 2 The particles having a higher dielectric constant than the electrodepositable polymer include titanium oxide, magnesium titanate, calcium titanosilicate, barium titanate,
Barium antimony titanate, strontium titanate, barium zirconate, barium stannate,
Characterized by being particles whose main component is one or more of lead zirconate, lead stannate, bismuth stannate, nickel stannate, strontium antimonate, lead antimonate, barium antimonate, and lanthanum sodium iron oxide. A method for producing a multicolored surface-colored body according to claim 1. 3. Formation of a colored layer based on a polymer layer selectively electrodeposited on the conductive layer described above is basically performed using a polymer electrolytically deposited by anodic electrolysis from a solution containing an anionic electrodepositable polymer. 2. A method for producing a multicolored surface-colored body according to claim 1, characterized in that the colored layer is formed based on a molecular layer. 4. The anionic electrodepositable polymer is an acrylic resin having a carboxyl group, a polyester resin having a carboxyl group, neutralized with an alkali to make it water-soluble, or a mixture thereof with a water-soluble melamine resin. A method for producing a multicolored surface-colored body according to claim 3, characterized in that: 5. The method for producing a multicolored surface-colored body according to claim 1, wherein the pigment is a pigment that is poorly soluble or insoluble in water.