JPH05131170A - Painting pretreatment method - Google Patents

Abstract

PURPOSE:To apply an adhesive or paint to the surface of metal or glass by placing metal or glass between opposed electrodes and performing glow discharge between both electrodes in the presence of inert gas or inner gas and ketone to apply plasma treatment to the surface of the metal or glass. CONSTITUTION:Metal or glass is positioned between opposed electrodes and glow discharge is performed between both electrodes in the presence of inert gas or inert gas and ketone to apply plasma treatment to the surface of the metal or glass. As a result, an adhesive or paint can be applied to the surface of metal or glass.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretreatment method for coating when an adhesive or paint is applied to metal or glass.

[0002]

2. Description of the Related Art It is difficult to apply paint or adhesive to the surface of metal or glass. Conventionally, in the case of metal, pretreatment such as degreasing or rusting is applied and then primer coating is applied, and glass In the case of such a ceramic surface, it is usually treated with a special substance such as a silane coupling agent or incorporated into a paint.

However, these treatments are complicated, and some chemicals are expensive, or when the treatments are carried out in an aqueous solution, the wastes from the treatment baths cause environmental pollution. However, there is a drawback that the above problem is likely to occur.

On the other hand, conventionally, a surface treatment method in which a raw material is made into plasma by glow discharge and the surface is modified by this is known as a surface treatment method of plasma chemistry, but recently, it is stable at atmospheric pressure. Since the glow discharge has become possible, the surface treatment method using plasma has become popular.

[0005]

Therefore, when the present inventor performed surface treatment by plasma treatment on metal or glass, the paint or adhesive could be extremely easily adhered and coated without any pretreatment. The present invention has been completed, and an object of the present invention is to provide a pretreatment method for coating metal or glass.

[0006]

SUMMARY OF THE INVENTION The gist of the present invention is to place a metal or glass between opposing electrodes and perform a glow discharge between both electrodes in the presence of an inert gas or an inert gas and a ketone. A pretreatment method for coating, which comprises treating the surface of metal or glass.

That is, a glow discharge is performed between both electrodes to plasma-treat the surface of the metal or glass, thereby enabling the paint or the adhesive to adhere to each other.

The present invention will be described in more detail. The metal to be treated in the present invention may be, for example, any metal such as brass, aluminum, stainless steel, iron, steel, etc., which may be subjected to processing such as cold rolling or hot rolling. The form may be plate-like, powder-like, net-like, wire-like or molded. The same applies to glass products. The present invention is particularly advantageous for the treatment of stainless steel, aluminum or brass that does not require corrosion resistance.

The present invention uses an atmospheric pressure glow generator. Specifically, the upper and lower electrodes are laminated with a dielectric film larger than the electrodes, and an inert gas is introduced into the container,
Position the metal or glass plate between the electrodes or on the lower electrode,
High-frequency high voltage is applied to both electrodes to generate glow discharge.

The inert gas used is helium,
The atmosphere is an inert gas such as a gas such as argon or nitrogen or a mixed gas thereof. In the case of argon gas alone, when voltage is applied between the electrodes, glow discharge does not occur and filament discharge occurs, so it is necessary to add a small amount of ketones, preferably acetone vapor, to the argon gas. The mixing ratio of argon gas and ketone is 99.99 parts of argon to ketone.
5 parts of ketone are added to 95 parts of argon rather than 0.01 part. It can be used even if the proportion of ketone is large, but since the odor of ketone will be very strong, it is preferable to use argon 9 9 parts than 99.9 parts of ketone added argon 0.1 part.
8 parts with 2 parts of ketone added. As a means for adding the ketones, usually, an inert gas is passed through the liquid of the ketones or passed over the ketones to contain the vapor. Further, nitrogen gas may be mixed with a mixed gas of argon and ketone.

With respect to nitrogen gas, since it is difficult to discharge nitrogen gas alone, it is advisable to mix it in a small amount, for example, about 20% in helium.

The means for causing a glow discharge between both electrodes to generate plasma is not much different from the case of the usual plasma surface treatment. That is, the voltage is 2000V-6000V, the frequency is 200Hz
~ 100,000Hz is required. Since it becomes a radio wave at 100,000 Hz or more, it can be used, but is not preferable. Usually 500Hz ~ 50,
Although it is 000 Hz, the preferred range is 1000 Hz to 10,000 Hz.

The distance between the electrodes varies depending on the type of inert gas or metal or glass to be treated, but is usually 50 mm to 1 mm, preferably 20 mm to 5 mm.
It is about mm.

The processing time is about 20 seconds to 20 minutes, and although the thickness of the thin film formed by increasing the processing time increases, the economical efficiency decreases, so the processing time is usually within the above range. Time.

In the present invention, since a glow discharge is performed under atmospheric pressure to generate plasma, continuous processing is possible, and therefore,
A long object to be processed can also be continuously turned into plasma. The surface treated according to the present invention has adhesiveness to any paints and adhesives as well as general-purpose paints made of vinyl chloride-vinyl acetate copolymer.

Next, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 A polyimide film having a thickness of 100 μm is attached to the upper and lower electrodes in a plasma reactor. This has a larger area than the electrodes. The electrode gap is 8 mm, a stainless SUS304 plate is placed on the lower electrode, and the container is filled with helium gas and completely replaced with air.

Next, a high frequency voltage of 5000 Hz and 3000 V is applied to set the output to 50 to 100 W. A beautiful purple glow is generated and plasma is excited, so the power is turned off within 5 minutes, then taken out, and a 20% methyl ethyl ketone (MEK) solution of S-REC A (made by Sekisui Chemical Co.) of acid vinyl chloride vinyl chloride polymer (MEK) is applied and dried. .. After that, a cross-cut test was performed. 100 /
At 100, the coating did not peel at all.

Incidentally, in the case where the same coating material was applied and dried without performing the plasma treatment, the coating film was easily peeled off and not adhered at all even without cross-cutting. The stainless SUS304 plate used in the test had a thickness of 1 mm and was degreased and washed before use.

Example 2 The same apparatus as in Example 1 was used to form stainless steel on the lower electrode.
A SUS304 having a thickness of 1 mm was placed, and a mixture of 60 parts of helium gas and 40 parts of argon gas was introduced into the container. next
High frequency voltage of 300Hz and 4000V was EPDO and output was 60W. A purple glow was generated and the plasma was excited, and then it was taken out within 3 minutes, and an adhesion test was conducted in exactly the same manner as in Example 1.
This was also 100/100 and did not peel at all. The untreated one was simply peeled off with a tape and was peeled off without any sound and was not adhered at all.

Example 3 A brass plate having a thickness of 2 mm was placed in the same apparatus as in Example 1, and a mixed gas of 99.9 parts of argon and 0.1 part of acetone was introduced to carry out glow discharge. High frequency voltage is 5000Hz, 3500V 1
It is 00W. A blue glow is generated and the plasma is excited. It was taken out in 1 minute, and in the same manner as in Example 1, the cross-cut 100/100 untreated one did not adhere at all. The ratio of argon gas to acetone is in the flow rate part. (Acetone is the gas flow rate of acetone converted from the gas chromatograph.)

Example 4 In the same manner as in Example 1, a thickness of 2 mm was formed on the lower electrode.
The glass plate of No. 1 was placed, and a mixed gas of 99.5 parts of argon gas and 0.5 part of MEK was introduced. Next, a high frequency voltage of 10000 Hz and 2000 V was applied and the output was 100 W. A light sky blue glow was generated and taken out 3 minutes after being excited by plasma, and
The adhesion test was performed in exactly the same way as 100/100
Is. No such paint adheres to glass at all, which is surprising. Of course, the untreated product is easily peeled off into a film without touching it by touching it by hand.

Example 5 In exactly the same manner as in Example 1, a thickness of 1.5 mm was formed on the lower electrode.
Then, a mixture of 95 parts of helium gas and 5 parts of nitrogen gas was introduced. Next, between the upper and lower electrodes, 8000Hz, 2800
When a high frequency voltage of V or 60 W is applied, blue-violet color is generated and plasma is excited. After 3 minutes, the aluminum plate was taken out, and an adhesion test was conducted in the same manner as in Example 1, but 100/100 showed extremely strong adhesion. The untreated aluminum plate peeled off without sound and did not adhere at all.

Example 6 Just as in Example 1, a cold rolled copper plate having a thickness of 1 mm was placed on the lower electrode, and then helium gas was introduced. 5000Hz, 2000
When a high frequency voltage of V or 100 W is applied, a purple glow is generated and plasma is excited. The sample was taken out for 1 minute and an adhesion test was conducted in exactly the same manner as in Example 1, but 100/100 showed extremely strong adhesion. The untreated one did not adhere at all. All metals used in the examples were degreased with a solvent (Daiflon).

[0024]

As described above, the present invention has an effect of exhibiting adhesion to a paint or an adhesive by a very simple treatment of plasma treatment of a metal surface or a glass surface.

Claims (1)

[Claims] 1. A metal or glass is placed between opposing electrodes, and a glow discharge is performed between both electrodes in the presence of an inert gas or an inert gas and a ketone to plasma-treat the surface of the metal or glass. A pretreatment method for painting, which comprises: