JP3182653B2 - Pre-painting method - Google Patents

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 applying an adhesive or paint to metal or glass.

[0002]

2. Description of the Related Art It is difficult to apply a paint or an adhesive on the surface of a metal or glass. Conventionally, in the case of a metal, a primer coating is applied after performing a pretreatment such as degreasing or derusting. Such a ceramic surface is usually treated with a special substance such as a silane coupling agent, or blended in a paint.

However, these treatments are complicated, and some chemicals are expensive, or when the treatment is carried out in an aqueous solution, the waste from the treatment bath causes environmental pollution. However, there is a disadvantage that the above problem is easily caused.

[0004] On the other hand, a surface treatment method in which a raw material is converted into plasma by glow discharge and the surface is modified by this is known as a surface treatment method of plasma chemistry. Since glow discharge became possible, surface treatment methods using plasma have been actively performed.

[0005]

Therefore, the present inventor has applied a surface treatment to a metal or glass by plasma treatment. As a result, the paint or adhesive can be adhered very easily without any pretreatment. SUMMARY OF THE INVENTION An object of the present invention is to provide a pretreatment method for coating metal or glass.

[0006]

The gist of the present invention is to dispose a metal or glass between opposing electrodes and to apply a high-frequency electric current between the electrodes in the presence of an inert gas or an inert gas containing ketones.
This is a pre-coating treatment method characterized by performing atmospheric pressure glow discharge by applying pressure and plasma-treating the surface of metal or glass.

That is, by applying an atmospheric pressure glow discharge between the two electrodes and subjecting the surface of the metal or glass to plasma treatment, the adhesion of the paint or adhesive is made possible.

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

The present invention uses an atmospheric pressure glow generator. Specifically, bonded large dielectric target film from the electrode to the electrode opposed to vertically, in a container the inert gas or ketone
A glow discharge is generated by introducing a kind of inert gas , positioning a metal or glass plate between the electrodes or between the lower electrodes, and applying a high frequency high voltage to both electrodes.

As the inert gas used, helium,
This is an inert gas atmosphere such as a gas such as argon or nitrogen or a mixed gas thereof. In the case of using argon gas alone, when a voltage is applied between the electrodes, glow discharge does not occur, and a filamentous discharge occurs. Therefore, it is necessary to add a small amount of ketones, preferably acetone vapor, to the argon gas. The mixing ratio of argon gas to ketone is 99.99 parts of argon.
It is a product obtained by adding 5 parts of ketone to 95 parts of argon from that of 0.01 part. Although it can be used even when the proportion of the ketone is large, the odor of the ketone becomes severe.
It is obtained by adding 2 parts of ketone to 8 parts. As a means for adding the ketones, usually, an inert gas is passed through a liquid of the ketones or is passed over the ketones to contain the vapor. Alternatively, nitrogen gas may be mixed with a mixed gas of argon and ketone.

Since it is difficult to discharge nitrogen gas alone, it is preferable to mix a small amount of nitrogen gas, for example, about 20% with helium.

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

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

The processing time is about 20 seconds to 20 minutes. As the processing time is increased, the thickness of the thin film formed increases, but the economic efficiency decreases. Time.

In the present invention, since the plasma is generated by glow discharge under atmospheric pressure, continuous processing is possible.
A long object can also be continuously converted 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 polyvinyl chloride-vinyl acetate copolymer.

Next, the present invention will be described specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

【Example】

Example 1 A polyimide film having a thickness of 100 microns is bonded to upper and lower electrodes in a plasma reactor. This is of a larger area than the electrodes. The electrode gap is 8 mm. A stainless steel 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, and the output is set to 50 to 100 W. After a beautiful purple glow is generated and the plasma is excited, the power is turned off in 5 minutes, taken out, and a 20% methyl ethyl ketone (MEK) solution of Selec A (manufactured by Sekisui Chemical) of acid-vinyl chloride-polymer is applied and dried. . After that, a cross cut test was performed.
At 100, the coating did not peel at all.

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

Example 2 The same device as in Example 1 was used to place stainless steel on the lower electrode.
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
The high frequency voltage of 300Hz and 4000V was EPDO and the output was 60W. A purple glow was generated, and it was taken out in 3 minutes after being excited by plasma, and an adhesion test was performed in exactly the same manner as in Example 1.
This also did not peel at 100/100 at all. The untreated product was peeled off without any sound by simply peeling off with a cello tape, and did not adhere 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 cause glow discharge. High frequency voltage is 5000Hz, 1 at 3500V
00W. A blue glow is generated and plasma is excited. It was taken out in 1 minute, and the untreated one having a cross cut of 100/100 in exactly the same manner as in Example 1 did not adhere at all. The ratio between the argon gas and acetone is a flow rate part. (Acetone is the gas flow rate of acetone converted from a gas chromatograph.)

Embodiment 4 The thickness of 2 mm was formed on the lower electrode in the same manner as in Embodiment 1.
Was placed, and a mixed gas containing 99.5 parts of argon gas and 0.5 part of MEK was introduced. Next, a high frequency voltage of 10,000 Hz and 2000 V was applied, and the output was set to 100 W. Example 1 A light sky-blue glow was generated and was taken out 3 minutes after being excited by plasma.
The adhesion test was performed in exactly the same way as
It is. Such paints do not adhere to glass at all, which is surprising. Of course, the unprocessed one is easily peeled off in a film form only by touching by hand, and is not adhered at all.

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

Example 6 A cold-rolled copper plate having a thickness of 1 mm was placed on the lower electrode exactly as in Example 1, and helium gas was introduced. 5000Hz, 2000
When a high-frequency voltage of V and 100 W is applied, purple glow is generated and plasma is excited. The sample was taken out for 1 minute, and the adhesion test was carried out in exactly the same manner as in Example 1. However, 100/100 showed extremely strong adhesion. The untreated one did not adhere at all. In addition, all the metals of the Example used what was degreased using the solvent (Diflon).

[0024]

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

────────────────────────────────────────────────── (5) References JP-A-61-83232 (JP, A) JP-A-57-85821 (JP, A) JP-A 50-157227 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) B05D 1/00-7/26

Claims (1)

(57) [Claims] 1. A metal or glass is placed between opposed electrodes, and a high-frequency voltage is applied between the two electrodes in the presence of an inert gas or a ketone-containing inert gas to perform an atmospheric pressure glow discharge, whereby the metal or glass is discharged. A coating pretreatment method, which comprises subjecting a glass surface to a plasma treatment.