JPS6116421A - Method of producing insulating film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing an insulating film.

[Prior art]

Conventionally, polyester films, polyimide films, and the like have been widely used as electrical insulating materials in rotating machines, electronic devices, and the like. Such polyester, polyimide, and other films are generally formed by dissolving them in an organic solvent and casting from the solution.

However, such conventional manufacturing methods have disadvantages in that they require the use of large amounts of organic solvents and the manufacturing process is complicated.

[Summary of the invention]

The present invention was made for the purpose of solving the two drawbacks,
A dispersion type electrodeposition paint is used on one side of the copper foil to form an electrodeposited layer of the desired film thickness by electrodeposition, then heated to form a smooth and uniform insulation film, and then etched. The present invention proposes a method for manufacturing an insulating film that can be manufactured continuously in a simple process without using a large amount of organic solvent by removing the copper foil.

[Structure of the invention]

The present invention will be described in detail with reference to the drawings. The figure is a system diagram showing one embodiment of the present invention. In the figure, the role (
From 1), a thin copper foil (3) is sent into an electrodeposition bath (2) containing electrodeposition paint, and is moved through a roll (4) whose surface is insulated and covered with an elastic material such as rubber. . Then, in the electrodeposition tank (2), a DC voltage is applied between the counter electrode (5) and the copper foil (3) by the DC power supply (12), and electrodeposition is applied to one side of the copper foil (3) as desired. 9. Next, the copper foil (3) is passed through an organic solvent steam bath (6) and then through a baking oven (7) to heat and harden the deposited layer. , forming a smooth, uniform, continuous insulation film on the copper foil (3). The composite of silver foil and film is a pulley (sheave) (8)
The copper foil (3) is introduced into the etching tank (9) through the copper foil (3).
to form a continuous insulating film (3a). The insulation film (3a) is attached to the washing tank (
10), and then passed through a heating furnace (11) and then wound onto a take-up roll (13).

Treatment with an organic solvent is not necessarily necessary, and in addition to steam treatment, immersion is also possible. Dimethylformamide and the like can be used as the organic solvent. When treated with an organic solvent, the water-dispersed particles in the precipitated layer are partially swollen, and a continuous film without pinholes can be formed by heating. Further, a method of removing a part of the copper foil (3) by etching can be adopted in the case of forming a pattern, etc.

The electrodeposition paint used here is not particularly limited, but it cannot be used again if it is adversely affected by the etching solution when removing part or all of the copper foil in the etching process in the post-process. Particularly preferred electrodeposition paints include:
Examples include acrylic-modified epoxy-based water-dispersed electrodeposition paints and polyimide-based electrodeposition paints dispersed in organic solvents. As the etching solution, ammonium persulfate and ferric chloride are preferably used.

[Embodiments of the invention]

Examples of the present invention will be described below.

Reference Example 1 1,900 g of ion-exchanged water and 2.4 g of sodium lauryl sulfate are placed in a four-bottle flask, and while stirring, N2 gas is passed through the flask for about 30 minutes to replace the oxygen gas dissolved in the ion-exchanged water with N2 gas. Next, the flow of N2 gas was stopped, and the temperature was raised to 70°C. Next, a solution of 2.0 g of ammonium persulfate and 0.7 g of sodium bisulfite dissolved in 100 g of ion-exchanged water was added, and then immediately 240 g of acryloni-1-lyl and 8 g of α-methylstyrene were added.
A mixed solution of 0 g, 40 g of styrene, 20 g of methacrylic acid, and 20 g of glycidyl methacrylate was added dropwise over about 30 minutes, and after the addition was completed, the mixture was reacted at 70'C for 3 hours to form acrylic-modified epoxy water with a non-volatile content of 19.5%. A dispersed electrodeposition paint was produced.

Reference example 2 DuPont polyimide RC-505 in a four-loaf flask
Dissolve 7500 g in 2500 g of N-, (tylpyrrolidone. Then add 30 g of triethylamine and
Stir for 20 minutes at °C.

Subsequently, 10Q of acetone was charged into another fourth flask, and the above solution was added dropwise from a separating funnel over 2 hours while stirring to produce a non-aqueous polyimide dispersed electrodeposition paint.

Examples 1 to 2 Using the equipment shown in the figure, the acrylic modified epoxy water-dispersed electrodeposition paint manufactured in Reference Example 1 was placed in an electrodeposition tank (2), a voltage of 50 V was applied, and a copper foil ( After forming an electrodeposited layer on one side of 3), dimethylformamide vapor bath (6)
followed by hardening in a baking oven (7).

Further, the copper N (3) is removed by passing through an etching tank (9), and then washed with water in a water washing tank (10), followed by a heating furnace (1
After passing through 1), only the insulating film (3a) is wound up. By changing the electrodeposition voltage, an insulating film (3a) having a thickness of 50 μm and 11007z was obtained.

Examples 3 and 4 The thickness was determined in the same manner as in Examples 1 and 2, except that the non-aqueous polyimide dispersed electrodeposition paint manufactured in Reference Example 2 was used as the electrodeposition paint, and 100 μ was applied as the electrodeposition voltage. Insulating films (3a) with a diameter of 30 μm and 60 μm were obtained.

The properties of the insulating films obtained in Examples 1 to 4 above are shown in the following table.

The above results show that an insulating film with excellent properties can be obtained.

〔Effect of the invention〕

According to the present invention, an insulating film is manufactured by forming a film on one side of a copper foil by electrodeposition coating and then removing the copper foil by etching. It is possible to produce an insulating film with excellent properties at a temperature as low as 100%.

[Brief explanation of the drawing]

The figure is a system diagram showing one embodiment of the present invention, (1)
, (4) is a roll, (2) is an electrodeposition bath, (3) is a copper foil, (
5) is a counter electrode, (6) is a steam tank, (7) is a baking furnace, (
9) is an etching tank, and (10) is a washing tank.

Claims (4)

[Claims] (1) Using a dispersed electrodeposition paint, form an electrodeposited layer of desired thickness on one side of the copper foil by electrodeposition, then heat to harden the deposited layer, and then perform etching treatment. A method for producing an insulating film, which comprises removing part or all of the copper foil. (2) The method for producing an insulating film according to claim 1, wherein the dispersed electrodeposition paint is a water-dispersed acrylic-modified epoxy paint or a non-aqueous dispersed polyimide paint. (3) The method for producing an insulating film according to claim 1 or 2, characterized in that the deposited layer is treated with an organic solvent prior to heating. (4) The method for producing an insulating film according to claim 3, wherein the organic solvent is dimethylformamide.