JPS5838892B2 - Mizubun Sangata Go Seijyu Shivarnish Omochiitadenchiyakuzetsuendensenno Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an insulated wire using an electrodeposition coating method. In order to facilitate this, a surface film is formed by heating the water-dispersed synthetic resin varnish above the minimum film-forming temperature to evaporate part of the water in the resin layer, and further,
The resin layer is heated in a tube having a cross-sectional area 10 to 250 times larger than the cross-sectional area of the conductor to which the resin layer is electrodeposited at a high temperature higher than the lowest film-forming temperature of the water-dispersed Hewei resin varnish to complete the formation of the insulating film. This is a method for manufacturing an electrodeposited insulated wire.

When forming an insulating film by electrodepositing a water-dispersed synthetic resin varnish onto a conductive material using the electrodeposition coating method, the formation of this electrodeposited film is affected by the surrounding environment due to the presence of a large amount of water in the electrodeposited layer. Significantly influenced by conditions.

That is, when the ambient temperature is low, the water-dispersed composite resin particles do not sufficiently coagulate and fuse with each other, resulting in poor film formation.

Therefore, leveling (smoothness of the film surface) is also poor.

On the other hand, if the ambient temperature is too high, mutual aggregation and fusion of water-dispersed synthetic resin particles will be promoted, and film formation will occur quickly, but the water in the resin layer will not completely evaporate. As a film is formed on the surface layer, foaming occurs significantly,
A good film cannot be obtained.

For these reasons, in order to form a continuous film at high temperatures, it is necessary to skillfully control both the ambient temperature and the drying rate of the film at the same time. It has not been industrialized because it is very difficult to set the conditions.

For this reason, when forming an insulating film by electrodepositing a water-dispersed synthetic resin varnish onto a conductive material using the conventional electrodeposition coating method, it has been necessary to use an organic solvent as a film-forming aid.

By recovering this organic solvent, it is possible to improve economic efficiency and eliminate pollution, but complete recovery is difficult.
It is clear that such a conventional method using an organic solvent is not preferable from the viewpoint of reducing the unit price of the product, saving resources, and eliminating pollution.

This invention made it possible to manufacture insulated wires without the use of film-forming aids, which had previously been virtually impossible industrially. This is a new method for manufacturing insulated wires.

That is, after electrodeposition is performed on a conductive material such as a water-dispersed synthetic resin varnish using an electrodeposition coating method, the water-dispersed synthetic resin varnish is heated to a temperature higher than the minimum film-forming temperature of the water-dispersed synthetic resin varnish to remove some of the water in the electrodeposited film. is evaporated in a short period of time to form a translucent, smooth thin film on the epidermis, and then passed through a tube heated above the lowest film-forming temperature of the water-dispersed synthetic resin varnish to form a film.

This heated tube is filled with water vapor that has evaporated from the electrodeposited film, so the water in the electrodeposited film gradually evaporates, promoting film formation while suppressing foaming caused by rapid water evaporation. At the same time, agglomeration and fusion of the water-dispersed synthetic resin varnish particles also occur, completing the formation of a uniform continuous film.

In this way, a good water-dispersed synthetic resin electrodeposited insulated wire can be obtained without using an organic solvent as a film-forming aid.

As described above, the present invention is characterized by a two-step process of first forming a surface film of an electrodeposited film, and then completing the film formation by gradually evaporating the water inside the film.

Further, the material of the tube constituting the present invention is not particularly limited as long as it is a heat-resistant material, but glass, metal, etc. are generally used.

Figure 1 is a schematic configuration diagram of a conventional manufacturing apparatus, in which 1 is a long conductive material drawn in the direction of the arrow, 2 is an annealing furnace, 3 is a pretreatment tank, 4 is an electrodeposition tank, and 5 is a coating film. A forming aid application section, 6 a preheat curing section, and 7 a final heat curing section.

In the apparatus configured as described above, the long conductive material 1 to be coated with an insulating coating is first run through an annealing furnace 2 to improve workability, and then passed through a pretreatment tank 3 to coat the surface. 1. was washed and then placed in the electrodeposition tank 4 filled with water-dispersed synthetic resin varnish. - A resin layer is electrodeposited, and then a gaseous or liquid film forming aid is applied in a film forming aid applying section 5, and heated in the next preheating and curing section 6 to increase the volatile content. The portion is vaporized and further heated in the final heat curing section 7 to complete the insulating film.

In the conventional method based on such a structure, the film forming aid is consumed in the form of vaporization in the film forming aid applying section 5 and the preheating and curing section 6, making it economical and non-polluting. It was causing a loss.

FIG. 2 is a schematic diagram of an embodiment of the present invention, in which 8 is a preliminary heating drying section, and 9 is a heating drying section incorporating a tube.

FIG. 3 is a schematic configuration diagram for explaining the configuration of a heating drying section incorporating a tube, where 9a is a heating furnace, and 9b is a tube made of glass, metal, or the like.

Although the inner diameter of this tube varies depending on the wire diameter of the conductive material 1 running, it is usually about 10 (mviφ) to 50 (mythφ).

First, the electrically conductive material 1 having the electrodeposited resin film loses a part of the surface water in the electrodeposited film by evaporation in the preheating drying section 8 to form a translucent thin film.

The conductive material 1 further enters a tube 9b made of heated glass or metal, but here, the remaining water in the electrodeposited film does not evaporate rapidly due to the water vapor pressure inside the tube, but gradually evaporates. It evaporates to form a film, which is then cured in the final heating and curing furnace 7 to complete the film formation.

In this way, it has become possible to produce a water-dispersed synthetic resin electrodeposited insulated wire using a simple device without using the conventional method of applying a film-forming aid, which has been considered indispensable.

Next, the effects of the present invention will be illustrated by giving comparative examples based on the conventional method and examples of the present invention.

Comparative Example 1 45 parts of styrene (parts by weight, the same applies hereinafter), 45 parts of methyl acrylate, 5 parts of glycidyl methacrylate, 5 parts of methacrylic acid, 200 parts of ion-exchanged water, 2 parts of sodium raul sulfate, 0.1 part of potassium persulfate. , hydrogen sulfite)
0.033 part of IJum was placed in a polymerization vessel, and the mixture was stirred for 30 minutes under a nitrogen stream.

Then, a water-dispersed synthetic resin varnish was obtained by reacting for 4 hours while stirring at a temperature of 50 to 60°C.

This water-dispersed synthetic resin varnish was placed in an electrodeposition tank with a length of 50 cm, and a DC voltage of 2 V was applied between the 0.3φ bare copper wire and the counter electrode.
was applied and run at a linear speed of 18 m/min, followed by a length of 30 m/min.
The wire was sent to a film-forming aid dipping bath with a diameter of 1.5 cm, and after being dipped in N,N-dimethylformamide (DMF) for 1.2 seconds, it was cured by heating to obtain a good insulated wire with a finished film thickness of 25 μm.

Example 1 Using the varnish of Comparative Example 1, a DC voltage of 2 cm was applied using an apparatus having the configuration shown in Fig. 2, and the varnish was run at a linear speed of 18 m/min. was passed through for 4 seconds, and then passed through a heating drying section maintained at 150° C. and incorporating a glass tube with an inner diameter of 3 CrfL for 8 seconds, and then heated and cured to obtain a good insulated wire with a finished coating thickness of 25 μm.

Example 2 A water-dispersed synthetic resin varnish containing 53 parts of acrylonitrile, 27 parts of styrene, 9 parts of ethyl acrylate, 5 parts of methacrylic acid, and 5 parts of glycidyl methacrylate was obtained in the same manner as in Comparative Example 1.

A DC voltage of 2.5 V was applied to this varnish device with the configuration shown in Figure 2, and it was run at a linear speed of 20 m/min, then passed through a preheated drying section kept at 130°C for 3 seconds, and then The wire was soaked for 8 seconds in a heat drying section containing a glass tube with an inner diameter of 3 cIrL kept at 150° C., and then heated and cured to obtain a good insulated wire with a finished coating thickness of 26 μm.

The characteristics of the electric wires manufactured in Comparative Example 1 and Examples 1 and 2 are shown in Table 1.

As is clear from Table 1, the characteristics of the insulated wire produced by the method according to the present invention are comparable to those produced by the conventional method.

The electrodeposition varnish to which this invention can be applied is not limited to the above embodiments, and any commonly used water-dispersed synthetic resin varnish may be used.

As explained above, this invention is a new method for obtaining an insulated wire that is comparable to conventional methods without using film-forming aids and with a simple device, and is non-polluting while reducing the unit price of the product. This has a great practical advantage in that it can be used for various purposes.

In the above description, a horizontal type electrodeposited insulated wire manufacturing apparatus has been described, but the present invention can also be applied to a vertical type or similar apparatus.

[Brief explanation of the drawing]

Fig. 1 is a schematic block diagram of an apparatus showing a conventional method for manufacturing insulated wires using water-dispersed synthetic resin varnish, Fig. 2 is a schematic block diagram of an embodiment using the method of the present invention, and Fig. 3 is Second
It is an example of the block diagram of the heating drying apparatus incorporating the pipe|tube in a figure. In the figure, 1 is a conductive material, 2 is an annealing furnace, 3 is a pretreatment tank, and 4
5 is an electrodeposition tank, 5 is a film forming aid application part, 6 is a preheat curing part, 7 is a paper heating curing part, 8 is a preheat drying part, 9 is a heat drying part incorporating a tube, and 9a is a heating part. The furnace 9b is a tube made of glass or metal. The same symbols in the button diagrams indicate the same or equivalent parts, respectively.

Claims (1)

[Claims] 1. When a resin layer is electrodeposited on a conductor by electrophoresis using a water-dispersed synthetic resin varnish and then heated to form an insulating film, the conductor on which the resin layer has been electrodeposited is A step of forming a surface film by heating the water-dispersed synthetic resin varnish for a short time at a temperature higher than the lowest film-forming temperature to partially evaporate the water present in the resin layer, and a conductor on which the resin layer is electrodeposited. heating the water-dispersed synthetic resin electrodeposited insulated wire at a high temperature higher than the lowest film forming temperature of the water-dispersed synthetic resin varnish in a tube having a cross-sectional area of 10 to 250 times the cross-sectional area of the water-dispersed synthetic resin electrodeposited wire. Production method.