JPS61204396A - Formation of electrically electrodeposited semiconductive film - Google Patents

Abstract

PURPOSE:To form an electrically semiconductive uniform film on metal by forming an electrodeposited layer by electrophoresis with paint for electrodeposi tion contg. powdery and granular carbon treated with a surfactant and water dispersible varnish and by treating the electrodeposited layer with an org. sol vent. CONSTITUTION:Powdery or granular carbon is dispersed in a aqueous soln. contg. a surfactant and stirred. The treated carbon and water dispersible varnish are dispersed in water, metal to be coated is immersed in the resulting paint for electrodeposition, and DC voltage is applied to form an electrodeposited layer on the metal. The metal is then immersed in an org. solvent such as alcohol, dried and heated to form an electrodeposited film. This film has electric semiconductivity and a uniform thickness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for forming a semiconductive electrodeposited film using electrophoresis.

[Conventional technology]

Generally, when forming a semiconductive film on a metal surface, it has traditionally been formed by hand using a method such as brushing an organic and inorganic composite in which metal powder or conductive filler such as carbon is dispersed in a synthetic resin. has been done.

[Problem that the invention seeks to solve]

However, such conventional methods have the drawbacks that uneven coating occurs due to K-based coating such as brush coating, that a film of uniform thickness cannot be obtained, and that one person is required, resulting in long working hours and low working efficiency.

This invention was made to eliminate the conventional drawbacks in forming a semiconductive film on a metal surface, and is an electrodeposition paint obtained by dispersing powder or particulate carbon and water-dispersible varnish in water. The purpose of this method is to form semiconductive electrodeposited films on metal surfaces using electrophoresis.

[Means for solving problems]

That is, in this invention, in order to improve the dispersibility of the powder or particulate carbon, the powder or particulate carbon is treated with a surfactant in advance, and then the treated powder or particulate carbon is mixed with a water-dispersible varnish. The metal to be coated is immersed in the electrodeposition paint obtained by dispersing it in water,
After forming an electrodeposited layer on the surface of the object to be coated using an electrophoresis method, and then immersing the electrodeposited layer in an organic solvent solution that serves as an electrodeposited film forming aid. The purpose is to form a semiconductive electrodeposited film on the surface of the object by heating and drying.

[For production]

t(34) is a schematic diagram of a method for treating a surfactant to improve the dispersibility of powder or particulate carbon in one embodiment of the present invention, and FIG. A schematic diagram schematically showing a method for forming an electrodeposited layer on a surface. FIG. 3 is a cross-sectional view of an object to be coated and an electrodeposited layer in an embodiment of the present invention. FIG. 2 is a schematic diagram showing a process of immersing a coated object on which an electrodeposited layer is formed in an organic solvent in an embodiment of the invention.

In the figure, (l) is powder or particulate carbon.

C2) is a container, (3) is water added with a surfactant or a mixture of water added with a surfactant and an organic solvent, (l11 is a stirrer, (!r) is the metal to be coated, (6 ) is an electrodeposition tank, (7) is an electrodeposition paint, (f) is a water-dispersible varnish resin particle, (9) is a DC power source, (io) is an electrodeposition layer, and (11) is an electrodeposition film forming aid. The organic solvent (l2) is a treatment tank.

To carry out the present invention, first, as shown in FIG. After dispersing and stirring with a stirrer (4'), the treated carbon is dispersed in water with a water-dispersible varnish as shown in the diagram.
into the electrodeposition bath (6), and immerse the metal (3) to be coated in the electrodeposition paint (RI), and place the metal (!r) to be coated on the anode (+) side and the opposite electrode. The electrodeposition tank (6) is used as the cathode (-)
A DC voltage is applied from the DC power source ff) I'm to form an electrodeposited layer (10) as shown in Figure IEj on the metal (3) to be coated. Then, the organic solvent (l/l) that will be used as an electrodeposited film forming aid is placed in a treatment tank (l2) K as shown in Fig. 1. ! A semiconductive electrodeposited film is obtained by dipping the metal to be coated on which the electrodeposited layer /(7) is formed and then heating and drying it.Furthermore, the above process can be automated using known automation techniques.

As the powder or particulate carbon used in one embodiment of the present invention, any commercially available conductive powder or particulate carbon can be used without any particular limitation, such as Touchen Black WC (manufactured by Lion Corporation). ,XC-7coR(
(manufactured by CABO'l'') are suitable examples.

The surfactant used in one embodiment of the present invention is not particularly limited as long as it can serve as a dispersant, and preferred examples include sodium lauryl sulfate and sodium lauryl benzene sulfonate. The amount of surfactant added is preferably 100 parts by weight of 1O-y per 100 parts by weight of powder or particulate carboxylic acid. If the amount added is less than 10 parts by weight, the dispersibility of the powder or particulate carbon will be low, and if it is more than 100 parts by weight, a large amount of foam will occur when the powder or particulate carbon is processed by stirring in a volatile medium. This makes it difficult to process powdered or particulate carbon.

In the water added with a surfactant or the mixture of water added with a surfactant and an organic solvent used in an embodiment of the present invention, organic solvents to be mixed with water include alcohols, ketones such as methyl ethyl ketone, and acetone. etc. are mentioned as suitable ones.

The water-dispersible varnish used in one embodiment of this invention is 1
For example, suitable examples include acrylic epoxy-based, epoxy ester-based, acrylic rubber-based, and acrylonitrile ptadiene rubber-based water-dispersible varnishes, either alone or as a mixture.

The blending amounts of powdered or particulate carbon and water-dispersible varnish used in one embodiment of the present invention are as follows.

Based on 10011i parts of solid content of water-dispersible varnish.

A proportion of 5 to 100 parts by weight of powdered or particulate carbide is preferred. The blending amount of powder or particulate carbon is 5
1 below the heavy f section. ``The conductivity of the R coating is low, and if it exceeds 100 parts by weight, 1111 convexities will occur on the surface of the electrodeposition coating, making the film thickness uneven, and the viscosity of the electrodeposition coating will increase, causing powder or particulate carbon to form. In addition, the electrophoretic properties of the water-dispersible varnish may deteriorate, and the electrodeposited layer may sag when lifted from the electrodeposition paint.

One implementation of this invention F! There are no particular restrictions on the organic solvent used as the electrodeposited film forming aid used in AJK as long as it dissolves or swells the water-dispersible varnish resin particles.
For example, ethylene glycol and dimethylformamide are preferred.

Suitable metals to be coated for forming a semiconductive electrodeposition film according to the present invention include steel, copper alloy, aluminum,
◎ [Example] Next, this invention will be explained in more detail with reference to Examples, but the invention is not limited thereto.11'O Example As shown in FIG. ) with water 3009 and lauryl sulfate ester soda i as a surfactant.

9 was added, and then 20 (l) of conductive powder carbon Touch Nine Black EC (manufactured by Lion Corporation) was added as powder or particulate carbon T/1, and about 3
Conductive carbon powder with good dispersibility was prepared by stirring for a period of time. Next, acrylic epoxy water-dispersible varnish 10011 (solid content 20%) was added to this container + JIK water-dispersible varnish, and ion-exchanged water was added so that the total non-volatile content was 17% to prepare an electrodeposition paint.

As shown in FIG. 2, the obtained electrodeposition paint was placed in an electrodeposition layer (6). Also, in the same figure, the metal to be coated (
jl/1x100x10σ steel plate with electrodeposition paint (
7) Dip the copper plate (3) on the anode (+) side and the electrodeposition bath (6), which will be the counter electrode, on the cathode (-1 (III). During this period, apply a DC voltage &Ov using a DC power supply (?). The voltage was applied for 10 seconds to form an electrodeposited layer (10) having a thickness of ψ0 μm on the surface of the steel plate as shown in FIG.

Then, as shown in Fig. 1, the electrodeposited layer (lO) is shaped
After being immersed in a dimethylformamide (11) solution placed in a solution of 0.5 m (/u), it was heated and dried at 10° C. for io minutes, and then heated and dried at θ0° C. for 30 minutes to form an electrodeposited film.

The obtained electrodeposited film had semiconductivity and a uniform thickness. The volume resistivity of the electrodeposited film was measured to determine the conductivity. The results obtained are shown in the table.

Example Ko! The method of treating the surfactant shown in Example 1, the type of carbon, the type of water-dispersible varnish, the amount of carbon and water-dispersible varnish, the electrodeposition conditions, and the type of organic solvent used as a film-forming aid were Shown in the table. Otherwise, a semiconductive electrodeposited film was formed in the same manner as in Example I, and the volume resistivity was measured in the same manner as in Example 1. From the results, it was found that the electrodeposited film of this invention is a semiconductive electrodeposited film. This indicates that it has a sexual nature.

〔Effect of the invention〕

As explained above, the present invention involves treating powder or particulate carbon with a volatile medium containing a surfactant, and then dispersing it in water with a water-dispersible varnish. The metal to be used is immersed, and the powdered or particulate carbon and water-dispersible varnish resin particles are precipitated by electrophoresis to form an electrodeposition layer, and then an organic solvent is used as a film forming aid for the electrodeposition layer. Since the metal to be coated with the empty electrodeposited layer is immersed and then heated and dried to form an electrodeposited film, the process does not require manual labor and can be automated, and the working time can be shortened. Labor saving can be realized from the above, and furthermore, the formed electrodeposited film has semiconductivity and a semiconductive electrodeposited film having a uniform thickness can be obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a method for treating a surfactant to improve the dispersibility of powder or particulate carbon in an embodiment of the present invention. A schematic diagram schematically showing a method for forming an electrodeposited layer thereon, FIG. 3 is a cross-sectional view of an object to be coated and an electrodeposited layer in an embodiment of the present invention, and FIG. FIG. 2 is a schematic diagram of immersing a coated object on which an electrodeposited layer is formed in an organic solvent in one embodiment of the present invention. In the diagram, (1) is powder or particulate carbon;
(2) is a container, (3) is water with a surfactant added or a mixture of water with a surfactant added and an organic solvent, (4') is a stirrer, (S> is the metal to be coated, (6) is an electrodeposition tank;
(71 is an electrodeposition paint, (ff) is a water-dispersible varnish resin particle, (9) is a DC power source, (10) is an electrodeposition layer, (ll) is an organic solvent that becomes an electrodeposition film forming aid, (12) ) is a processing tank. In Figure 1, the same symbols indicate the same or equivalent parts. (3) Field @:g7H'3t6oehhyi< Reference hr
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Claims (4)

[Claims] (1) The metal to be coated is immersed in an electrodeposition coating obtained by dispersing powder or particulate carbon treated with a surfactant and a water-dispersible varnish in water, and the metal to be coated is immersed in the electrophoresis method. After forming an electrodeposition layer on the object to be coated, the object on which the electrodeposition layer has been formed is immersed in an organic solvent that serves as an electrodeposition film formation aid, and then heated and dried to form an electrodeposition film. A method for forming a semiconductive electrodeposited film, characterized by: (2) The content of the powder or particulate carbon and the water-dispersible varnish is 5 to 100 parts by weight of the powder or particulate carbon per 100 parts by weight of the solid content of the water-dispersible varnish. 2. The method for forming a semiconductive electrodeposited film according to item 1. (3) The semiconductor semiconductor according to claim 1, wherein the water-dispersible varnish is one of epoxy ester-based, acrylic epoxy-based, acrylic rubber-based, and acrylonitrile-butadiene rubber-based water-dispersible varnishes, either alone or as a mixture. Method for forming electrocoated films. (4) The method for forming a semiconductive electrodeposited film according to claim 1, wherein the metal to be coated is copper, copper alloy, aluminum, or iron.