JPS621245Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a continuous electrodeposition apparatus for continuously manufacturing insulated wires by electrodeposition. Immediately after being electrodeposited on a conductor, the electrodeposited layer is in a state where the precipitated resin is deposited in a stone wall shape, and if it is baked in that state, only an insulating film with pinholes will be obtained. In order to solve this problem, the electrodeposited layer is treated with an organic solvent prior to baking to lightly dissolve and swell the resin in the electrodeposited layer, making it easier for them to fuse together. ing. By the way, when a water-dispersed varnish is used as an electrodeposited varnish, water remains in the electrodeposited layer, but according to research by the inventors, water-soluble or partially water-soluble organic solvents The treatment effect varies greatly depending on the amount of water remaining in the electrodeposited layer during treatment. That is, if the residual moisture content is too small, it is difficult for the organic solvent to penetrate into the electrodeposited layer, and the entire electrodeposited layer cannot be treated uniformly, resulting in the formation of a baked insulating film with high dielectric breakdown strength. There is a difficult problem. On the other hand, if the amount of residual moisture is excessive, foaming occurs in the electrodeposited insulating film due to excessive water evaporation from the electrodeposited layer during baking, which also reduces the dielectric breakdown strength. According to subsequent research by the inventors of the present invention, good organic solvent treatment can be performed when the residual water content is about 50 to 80% by weight relative to the amount of precipitated resin. By using the device of the present invention shown in the above range, the moisture content immediately after electrodeposition can be kept within the above range. Can be manufactured continuously. The attached figure is a sectional view of an embodiment of the present invention, and shows 1
is an electrodeposition bath filled with a water-dispersed varnish 11, and a cylindrical electrode 12 is installed on the outlet side (the water surface of the water-dispersed varnish). The electrode may have a cylindrical shape, one plate or two parallel plates, or other shapes. When L is the length from the entrance to the exit of the electrodeposition bath 1, the length l of the electrode 12 is 0.1L to 0.7L. L
varies somewhat depending on the linear speed of the electrodeposited conductor W that runs continuously from bottom to top in the direction of the arrow, but the linear speed is 10 to 50.
m/min, and in that case, L is suitably about 20 to 200 cm. Reference numeral 2 denotes a DC power source, one end of which is connected to the electrodeposited conductor W through a power supply hole 21, and the other end to the electrode 12. The polarity of the electrode and electrodeposited conductor is determined by the type of water-dispersed varnish 11 used. The power source 2 is a DC power source that can apply a DC voltage between the electrodeposited conductor W and the electrode. 3 is an organic solvent treatment device installed directly above the electrodeposition bath, and 4 is a baking furnace installed above it. The electrodeposited conductor W continuously traveling in the direction of the arrow is electrodeposited in the electrodeposition bus 1 . The electrodeposited layer is used in the organic solvent treatment apparatus 3 (for example, in the
45-31555) using an organic solvent or its vapor or mist at high temperature and room temperature, and baked in a baking furnace 4 at a known baking temperature. Using the device of the present invention, the electrodeposited conductor W and the electrode 12
When electrodepositing by applying a direct voltage between good results are obtained. On the other hand, if the electrode length is longer or shorter than the above-mentioned length, or if the electrode is installed at the entrance or center of the electrodeposition bath, the moisture content of the electrodeposition layer may fall outside the above range. Therefore, an insulated wire with good voltage resistance characteristics cannot be obtained. In the present invention, since a short electrode is installed on the exit side of the electrodeposition bath, the electrodeposited conductor W is exposed to a gradually stronger electric field as it progresses from the entrance to the exit. The upward electrodeposition progresses gradually near the entrance and becomes more rapid toward the exit.At the same time as this electrodeposition progresses, the action of the electric field tightens the electrodeposited layer, and as a result of this action, appropriate dehydration occurs. The phenomenon occurs and an electrodeposited layer having the moisture content described above is obtained. The attached table shows the results of manufacturing insulated wires using the devices of various examples and comparative examples. In the same table, the water content of the electrodeposited layer indicates the water content of the electrodeposition layer before organic solvent treatment, and the dielectric breakdown strength and appearance are for the baked electrodeposition layer. Immediately after electrodeposition, the electrodeposited layer was treated with dimethylformamide vapor (temperature of about 100°C) for about 5 seconds, and then baked at a maximum temperature of 400°C. Varnishes A, B, and C shown are of respective compositions. Also, the wire size is 0.5mmφ, the coating thickness is 0.025mm, and the wire speed is 20.
m/min. Varnish A: Epoxy acrylic emulsion resin concentration approximately 20%. Varnish B...Commercially available acrylic varnish Cavalite
(Manufactured by Dupont) Resin concentration approximately 20%. Varnish C…Commercial acrylic varnish Ercusol
(Manufactured by Bayer) Resin concentration approximately 20%.

【table】

【table】 [Brief explanation of the drawing]

The attached figure is a sectional view of an embodiment of the present invention, in which 1 is an electrodeposition bath, 12 is an electrode installed at the outlet of the electrodeposition bath, 2 is a power source, 3 is an organic solvent treatment device, and 4 is a baking furnace.

Claims (1)

[Scope of utility model registration request] an electrodeposited bath filled with a water-dispersed varnish; an electrode with a length of 0.1L to 0.7L (L is the length between the inlet and the outlet of the electrocoat bath) installed close to the outlet of the bath;
A charging device capable of applying a DC voltage between an electrodeposited conductor and the electrode, and a device that treats an electrodeposited layer electrodeposited on a conductor with a water-soluble or partially water-soluble organic solvent. A continuous electrodeposition device comprising: