JPS6237396A - Production of body coated by electrodeposition - Google Patents

Abstract

PURPOSE:To produce a body coated by electrodeposition and having superior dielectric strength and mechanical strength by forming an org. polymer layer on the surface of a body to be coated with varnish for electrodeposition, treating the layer with mist of an org. solvent generated by ultrasonic waves, and baking the layer. CONSTITUTION:A conductor 1 to be covered with an insulating layer is introduced into an electrodeposition tank 2 contg. varnish 21 for electrodeposition such as acrylic varnish to form an org. polymer layer. This layer is treated with mist 31 of an org. solvent such as DMF in a mist treatment chamber 3. The mist 31 is continuously fed to the chamber 3 through a duct 51 by atomizing the org. solvent 56 in a hermetically sealed vessel 54 by vibration with a vibrator 55 for generating ultrasonic waves and by providing the desired state of mist to the resulting fine particles with air or the like introduced from a feed pipe 52. The conductor 1 is then sent to a baking furnace 4, where the org. polymer layer is baked to obtain an insulated electric wire 1'.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric wire suitable for manufacturing articles such as insulated wires that require an organic polymer coating layer with excellent voltage resistance and mechanical strength. The present invention relates to a method for producing a coated body.

BACKGROUND OF THE INVENTION Conventionally, as a method for producing an electrodeposited object, an organic polymer layer is formed on the surface of an object to be coated by passing it through an electrodeposition varnish bath while being electrically charged, and this is baked. A known method is to treat the organic polymer layer prior to the baking treatment with an organic solvent mist formed by mixing air at room temperature with vapor obtained by boiling an organic solvent under heating. In this mist treatment, the organic polymer layer formed during electrodeposition has a bulky structure consisting of a deposited layer of granular resin, so the mist swells or dissolves the granular resin and forms the particles. The purpose is to destroy the structure and thereby form a pinhole-free baked coating.

Problems to be Solved by the Invention However, in the conventional method, the organic solvent mist was generated by mixing room-temperature air with the solvent vapor obtained by boiling the organic solvent under heating.
It had the following problems (i) and (ii).

(i) It is desirable to optimize the particle size and concentration of the organic solvent in the mist, as well as the temperature of the mist itself, depending on conditions such as the type of electrodeposition varnish and the electrodeposition processing speed.
The adjustable range of conventional mist generation methods is extremely narrow. Therefore, in the conventional method, there is a limit to increasing the electrodeposition processing speed, and the production efficiency is not satisfactory.

(11) When using an organic solvent with a high boiling point, a large amount of heating energy is required to generate the vapor,
Furthermore, since the generated steam is at a high temperature, control for optimizing processing conditions becomes more difficult.

Means for Solving the Problems and Effects The present inventors have conducted extensive research to overcome the above problems, and as a result, have discovered that the purpose can be achieved by a method of generating organic solvent mist using ultrasonic waves.

The method of generating mist by ultrasonic waves is the same as that of ultrasonic humidifiers, etc., and the amount of mist generated, particle size, etc. are determined by the frequency,
It can be easily controlled by adjusting the output, the distance from the vibrator to the liquid surface, etc. Therefore, according to the organic solvent mist generation method using ultrasonic waves, it is easy to control the amount of organic solvent particles generated regardless of the boiling point of the organic solvent. A wide range of mist conditions can be easily created.

The method for producing an electrodeposited object of the present invention involves forming an organic polymer layer on the surface of the object to be renovated by an electrodeposition method using an electrodeposition varnish, and then applying an organic It is characterized in that it is treated with a solvent mist and then subjected to a baking treatment.

Hereinafter, the method of the present invention will be explained using an example of manufacturing an insulated wire.

The figure is a flowchart of the manufacturing process. The conductor 1 to be insulated is first placed in an electrodeposition bath 2 containing an electrodeposition varnish 21.
The insulated electric wire 1' is then manufactured by passing through the mist treatment chamber 3 and the baking furnace 4 successively.

In the electrodeposition tank 2, the resin in the electrodeposition varnish is deposited on the conductor based on the voltage difference under the energized state while passing through the tank 2, thereby forming an organic polymer layer.

In the mist treatment chamber 3, the organic polymer layer is treated by the organic solvent mist 3I that fills the chamber while passing through the mist treatment chamber 3.

At this time, an organic solvent mist 31 is produced in the mist generator 5 and continuously supplied to the mist processing chamber 3 through the conduit 51. The mist generator 5 has a structure in which a vibrator 55 for ultrasonic oscillation is installed on the bottom surface of a closed container 54 having an air supply pipe 52 and an organic solvent supply pipe 53.
Due to the vibrations, the organic solvent 56 that is constantly supplied into the closed container 54 via the limb tube 53 and always filled with a certain amount exhibits a well-known pseudo-boiling state, causing fine particles of organic solvent to flow into the gas phase within the container 54. released into the The discharged fine particles are mixed with air or other gas supplied through the supply pipe 52 to form a mist, and reach the mist processing chamber 3 through the conduit 51.

The size and concentration of organic solvent particles in the mist are determined by the imaging intensity of the sensor, the imaging frequency, and the organic solvent 5 in the container 54.
The mist atmosphere can be controlled by changing the depth between the liquid surface 6 and the upper surface of the camera element 55, the amount of gas (air) supplied, etc., and a desired mist atmosphere can be created.

In the baking furnace 4, the mist-treated organic polymer layer is baked onto the conductor 1 while passing through the baking furnace 4, and thus the insulated wire 1' is continuously produced.

In the present invention, the electrodeposition varnish is an organic solvent-based varnish,
Any water-based varnish can be applied, but the coating properties of water-based varnishes, such as water-dispersed varnishes and water-borne projection varnishes, are particularly improved by treatment with organic solvent mist. Dispersion varnishes, such as acrylic varnishes such as acrylic varnishes and acrylic-epoxy varnishes.

The organic solvent for forming the mist may be any chemical type as long as it swells or dissolves the resin in the organic polymer layer formed by electrodeposition and collapses the particle deposition structure of the polymer layer. It can be used without When the electrodeposited varnish is aqueous, a hydrophilic solvent such as dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. is preferred, especially dimethylformamide is preferred when the electrodeposition varnish is an acrylic-epoxy resin. used.

In the present invention, there are no particular limitations on the electrodeposition treatment conditions and baking treatment conditions (it is possible to apply conventional treatment conditions. To give specific values, the temperature of the electrodeposition bath is 5 to 60°C.
, solid content concentration 2-40% by weight, processing voltage 1-300V,
Generally, the current application time is 1 second to 5 minutes.

Effects of the Invention According to the present invention, since the mist generation method uses ultrasonic waves, less energy is required for mist generation even when using a high boiling point solvent. It is possible to manufacture and supply mist with good controllability. As a result, an electrodeposition coating film having excellent electrical insulation properties, mechanical properties, etc. can be formed with high efficiency.

Therefore, the present invention is particularly suitable for producing electrocoated objects such as insulated wires and loose-leaf coated iron wires for binders, which require high-quality electrocoated ml. Furthermore, it can also be used as a post-treatment when painting articles by electrodeposition, such as top coating treatment of metal-plated articles.

Example A mild steel wire with a diameter of lim was used as an anode, and was coated with acrylic-epoxy varnish (solid content 15% by weight, manufactured by Ryoden Kasei Co., Ltd., V-
551-20) into an electrodeposition bath (25°C),
The acrylic-epoxy resin layer was formed on the mild steel wire by passing through the wire (current application time: 5 seconds, processing voltage: 7 V).

Next, this is introduced into a mist processing chamber (room temperature) where a mist flow obtained by generating fine particles of dimethylformamide using an ultrasonic oscillator and mixing them with air is continuously supplied, and then passed through (passing time: 10 seconds). After mist treatment, the wire was passed through a baking furnace (430° C.) for baking treatment to obtain an insulated wire with an insulating layer thickness of 0.035 mm+.

This electric wire had excellent appearance and uniformity of the insulating layer.

[Brief explanation of the drawing]

The figure is a flowchart for manufacturing an insulated wire, which is an embodiment of the method of the present invention.

Claims (1)

[Claims] 1. An organic polymer layer is formed on the surface of the object to be coated by electrodeposition using an electrodeposition varnish, and then the organic polymer layer is coated with a mist of an organic solvent generated by ultrasonic waves. A method for manufacturing an electrodeposited body, which comprises performing a baking treatment after the treatment. 2. The electrodeposited varnish is a water dispersion type or an aqueous solution type,
2. The method according to claim 1, wherein the organic solvent is a hydrophilic solvent. 3. The method according to claim 2, wherein the water-dispersed varnish is an acrylic varnish and the organic solvent is dimethylformamide.