JPH0464875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing multicolored patterns on a substrate. In general, methods for obtaining multicolor patterns include, if the substrate is glass, a coloring method by surface diffusion of metal ions, a coloring method by printing and baking using a low melting point glass frit, or a coloring method using an organic polymer binder. A coloring method is known in which a printed pattern is formed using an ink containing .

However, each of these methods has its advantages and disadvantages; for example, the coloring method by diffusion of metal ions,
Although the glass surface maintains flatness, it has the disadvantage that the process is complicated and that it cannot be colored with any desired hue.

Also, with the printing method, it is difficult to print on glass, and the colored layer itself lacks uniformity.
Lack of transparency etc.

Furthermore, these methods have a common drawback in that they become more difficult as the pattern becomes finer and the number of colors increases, resulting in deviation from the desired pattern position.

Even when the substrate is made of a material other than glass, there are methods such as printing to obtain a multicolor pattern, but this still becomes extremely difficult as the pattern becomes finer and multicolored.

One way to obtain fine patterns is to use photolithography, but this method also has the disadvantage that it is necessary to go through a photolithography process each time a multicolor pattern is created, making the process extremely complicated. have

Therefore, in the present invention, in order to easily obtain a fine and multicolored arbitrary pattern, a conductive thin film is patterned on a substrate whose surface is insulating, and then the conductive thin film is used as an electrode to form a polymer. This paper proposes a method for producing a multicolor pattern using electrodeposition as a colored layer.

According to this method, by applying desired patterning to a conductive thin film by vapor deposition using a mask, sputtering, or etching, polymers are selectively electrodeposited on conductive parts, and the pattern position does not shift. It is possible to form a colored layer. As long as the surface of the substrate used in this method is insulating, the material and shape of the substrate are not limited as long as a conductive thin film layer with good adhesion to the substrate is selected.

By the way, one method for obtaining a multicolor pattern by 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. 19, No. 12, 1968). Recently, research has also been actively conducted in which conductive polymer films 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 not good and the obtained film is already colored and lacks coloring arbitrariness. There are problems.

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. As a method for electrodepositing a polymer on an electrode, there is a method in which the polymer is insolubilized and deposited on the electrode from a polymer solution. An example of this is dispersing pigments in an aqueous polymer solution.
A method called electrodeposition coating, in which a metal is immersed and used as an electrode, and a colored layer is electrodeposited on the metal, is known industrially, and is used for pre-coating automobile bodies. The principle of this method is to introduce a hydrophilic group, such as a carboxyl group, into a polymer, and then neutralize the carboxyl group with an inorganic alkali, organic amine, etc. to make it water-soluble. Then, when the electrode is immersed in an aqueous solution of the water-soluble polymer and a voltage is applied, the carboxyl anions dissociated in the aqueous solution migrate electrophoretically and react with protons generated by water electrolysis on the electrode. Polymers become insolubilized and precipitate. That is, the reaction shown in the following formula occurs on the anode, and polymer precipitation is observed.

On the other hand, if a basic group (for example, a polyamine containing an amino group) is used as the hydrophilic group and is neutralized and water-solubilized with an acid, polymer precipitation will be observed on the cathode.

If the electrodeposited polymer is electrically insulating, the current decreases as the electrode is coated with the polymer, and further coating can be prevented, so an increase in film thickness cannot be expected. Due to the oxygen bubbles generated by decomposition, complete coverage is avoided and a certain film thickness can be obtained. Furthermore, the obtained polymer film becomes a uniform film with low water content due to the effect of electroosmosis.

The following materials, all of which contain carboxyl groups, are used as polymers for electrodeposition. Adducts of natural drying oils such as linseed oil containing oleic acid 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 their Copolymers with esters are used, and other polymers or organic compounds having functional groups may be introduced into the skeleton depending on the characteristics of the electrodeposited film. These polymers are arbitrarily selected depending on the desired properties of the colored layer. For example, when the colored layer is desired to be transparent, acrylic polymers are suitable. Methods for producing polymers for electrodeposition differ depending on the type of polymer, but a method for producing acrylic polymers will be described as an example. Acrylic polymers are produced by radical copolymerization of acrylic acid or methacrylic acid having a carboxyl group and an acrylic ester or methacrylic ester having a neutral group. In this case, the ratio of carboxyl groups to neutral groups is important; if there are too many carboxyl groups, the electrodeposited polymer will not be sufficiently insolubilized, and if there are too few carboxyl groups, water solubility during neutralization will be insufficient. Become. Also, to increase water solubility, OH
In some cases, groups are introduced. Once the monomer composition is determined, polymerization is usually carried out using a hydrophilic solvent such as isopropanol, n-butyl alcohol, t-butyl alcohol, methyl cellosolve, ethyl cellosolve, isopropyl cellosolve, butyl cellosolve, diethylene glycol methyl ether, diethylene glycol ethyl ether, diacetone alcohol, etc. Solution polymerization is carried out using a general radical polymerization initiator.

Since the polymer film obtained by electrodeposition cannot be used as a colored layer as it is, a means for coloring it is required. A common method is to disperse pigments in an aqueous polymer solution for electrodeposition. The pigments used include titanium oxide, precipitated barium sulfate, talc, asbestin, china clay, red iron oxide, yellow iron oxide, strontium chromate, basic lead silichromate, phthalocyanine blue, phthalocyanine green, Hansa yellow, and carbon black. The pigment is electrically charged in an aqueous polymer solution, and the polymer is adsorbed to its surface, electrophoresed together with the polymer, and incorporated into the electrodeposited film.

However, coloring with such pigments generally lacks transparency and may be inappropriate when a multicolor pattern is formed on a transparent substrate such as glass and the color is displayed through transmission. Therefore, as another example of the coloring method used in the present invention, a method for producing a light-transmitting multicolor pattern using a glass substrate will be described. A transparent conductive film made of tin oxide, indium oxide, or the like is formed on a glass substrate by a method such as spray coating or sputtering, and then patterned by a chemical or dry etching method. A polymer is electrodeposited in a neutralized aqueous solution of a copolymer of acrylic acid or methacrylic acid and its ester using a portion of the transparent conductive film pattern having the same desired color as an anode. After washing and baking, cationic dyes for acrylic resins, such as Aizen Cathilon, Diacryl,
Sumiacryl, Astrazon, Basacryl, Drorlene,
Dye with Maxilon, Sevron, etc. (Dye Handbook).

By repeating this operation, a multicolored pattern with good transparency can be obtained on the glass. Even when other transparent polymers are used, similar effects can be obtained by selecting a dye that is compatible with the polymer. For example, disperse dyes are effective for polyester.

Hereinafter, specific examples of the present invention will be described.

<Example 1> Polyester-melamine resin paint (ESBIA ED-3000) was prepared by patterning aluminum on a ceramic substrate by vapor deposition, introducing carboxyl groups, and copolymerizing polyester neutralized with an organic alkali amine and melamine. Manufactured by Shinto Paints.
This is a paint whose main component is polyester into which carboxyl groups have been introduced. ) was made into an aqueous solution with a resin solid content of 10% by weight, a pigment was dispersed therein, and electrodeposition was performed at a voltage of 100 to 150 V using the aluminum vapor-deposited film as an anode. After the water washing process to wash off the solution adhering to the ceramic substrate and the baking process to heat the substrate and solidify the colored layer, a uniform colored pattern with no protrusion from the pattern can be obtained even if it is a minute pattern, making it possible to achieve precision that cannot be achieved with printing. Decoration is now possible.

<Example 2> Tin oxide is formed on a glass substrate by spray coating, and the desired pattern is left and the rest is removed by etching. The weight content of acrylic acid is 10-40
% of acrylic acid-methyl acrylate copolymer having a carboxyl group was neutralized with triethylamine, an organic alkali, to a pH of 7.5~
8.5. Create an aqueous solution with a polymer content of 10% by weight.
Electrodeposition is performed in this aqueous solution at a voltage of 10 to 50 V using the tin oxide transparent conductive film on the glass substrate as an anode. After washing and baking, the pattern had good transparency and the formation of a polymer film was observed. By dyeing this polymer film with a cationic dye, a uniform colored pattern with good transparency and no pattern shift was obtained. It has become clear that when a tin oxide transparent conductive film is used as a cathode in an aqueous solution, tin reduction occurs, so it is not preferable to use it for polymers such as polyamines that are deposited on the cathode. Such highly transparent fine multicolored patterns can be expected to be applied to color filters for display devices, image pickup tubes, and the like.

<Example 3> A transparent conductive film of indium oxide was patterned on a glass substrate by sputtering using a mask method, and a colored pattern was formed in the same manner as in Example 2. In the case of indium oxide, a phenomenon in which the current suddenly decreased during electrodeposition was observed, but a uniform colored pattern was obtained as in Example 1. It has become clear that indium oxide, like tin oxide, undergoes a reduction reaction on the cathode side and is not suitable for use in polymers that precipitate on the cathode.

As specifically described in the examples above, the method for manufacturing multicolor patterns according to the present invention is extremely versatile, as long as the desired patterning of the conductive thin film layer can be achieved, the electrodeposition conditions and coloring method can be appropriately selected. , it is possible to create a simple and precise multicolor pattern.

Claims (1)

[Claims] 1. A conductive thin film layer having an arbitrary pattern is formed on a substrate whose surface is insulating, and a functional group in the form of a carboxyl group neutralized with an alkali or an amino group neutralized with an acid is formed. The substrate is immersed in a solution containing a pigment and an electrodepositable polymer, and a voltage is applied to the conductive thin film layer on which a colored layer is to be formed. and a step of heating the substrate and solidifying the colored layer by baking, and then repeating the steps of and with a solution containing a different pigment. A method for producing multicolored patterns. 2. The method for manufacturing a multicolor pattern according to claim 1, wherein the substrate is transparent. 3. The method for producing a multicolor pattern according to claim 1, wherein the electrodepositable polymer has a skeleton of polyester or acrylic resin. 4 Electrodepositable polymer having a functional group in the form of a carboxyl group neutralized with an alkali or an amino group neutralized with an acid, formed by forming a conductive thin film layer with an arbitrary pattern on a substrate with an insulating surface. a step of immersing the substrate in a solution in which the colored layer is to be formed, applying a voltage to the conductive thin film layer on which the colored layer is to be formed, and forming the electrodepositable polymer on the conductive thin film layer; A step of dyeing the electrodepositable polymer on the conductive thin film layer with a dye to form a colored layer, and a step of heating the substrate and solidifying the colored layer by baking, and then dyeing the colored layer with a different dye. A method for producing a multicolor pattern, characterized by repeating the steps of. 5. The method for manufacturing a multicolor pattern according to claim 4, wherein the substrate is transparent. 6. The method for producing a multicolor pattern according to claim 4, wherein the electrodepositable polymer has a skeleton of polyester or acrylic resin.