JPH04103773A - Surface treated metallic material and its production - Google Patents

Abstract

PURPOSE:To obtain a surface treated metallic material excellent in adhesive strength to a coated film, etc., by applying chemical conversion treatment to a metallic material and then performing low temp. plasma treatment from the position above the resulting chemical conversion treated surface under the prescribed pressure of atmospheric gas. CONSTITUTION:Chemical conversion treatment, such as zinc phosphate treatment and chromate treatment, is applied to a metallic material, such as steel sheet. Subsequently, low temp. plasma treatment is applied to the chemical conversion treated surface from the position above this surface under <=10Torr pressure of atmospheric gas, such as Ar and O2. Further, it is preferable that the above plasma treatment is performed under the conditions of about 0.001-0.1Torr atmospheric gas pressure and >= about 100W discharge electric power. By this method, superior adhesive strength to an undercoated film, etc., can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a surface-treated metal material whose surface is subjected to a chemical conversion treatment and then subjected to low-temperature plasma treatment from above the chemical conversion treated surface. The present invention relates to a surface-treated metal material that has adhesion, corrosion resistance, and press workability and is suitable for various uses such as automobiles, architecture, furniture, tanks, and home appliances, and a method for manufacturing the same.

BACKGROUND OF THE INVENTION Currently, metal materials are used in various applications such as architecture, furniture, tanks, motorcycles, and home appliances.

In this case, the metal material is usually coated and used depending on the purpose.

For example, a steel plate for automobiles that requires corrosion resistance, formability, and spot weldability has been proposed in which a steel plate is pretreated for painting and then an organic thin film is formed thereon (Japanese Unexamined Patent Publication No. 1-209133 issue).

There are two types of these: those that are used as-is after being joined by molding and spot welding, and those that are used as is after being painted (electrodeposition,
Some are used after applying an intermediate coat or top coat.

In the former case, the adhesion between the organic thin film and the chemical conversion treatment that is the pre-painting treatment must be strong, and a decrease in adhesion (peeling of the thin film) becomes a problem, especially in humid or salt spray environments.

Moreover, in the latter case, in addition to this, there is an additional problem of paint topcoatability.

On the other hand, a method for forming a multilayer coating film with improved interlayer adhesion has been disclosed, in which the surface of the base coating film is subjected to low-temperature plasma treatment, and then a top coat film is coated on the surface of the base coating film (Japanese Patent Application Laid-Open No. 2003-120003-1). No. 44985).

However, in this prior example, as stated in the specification, "the gas pressure in the low-temperature plasma atmosphere is 0.1~
It is preferable that the pressure be within the range of 10 Torr.The reason for this is that if the gas pressure exceeds 10 Torr, a low-temperature plasma atmosphere tends to occur, and even if it does occur, it will be unstable and it will be difficult to obtain high processing efficiency. If the gas pressure is less than 0.1 Tart, the concentration of active species generated by the low-temperature plasma WJ atmosphere is insufficient, and high processing effects tend not to be obtained. ”.

Problems to be Solved by the Invention In general, even if paint films have good adhesion at the initial stage of use, they tend to deteriorate and peel over time due to the influence of the environment such as heat and water. Therefore, in order to evaluate the "secondary adhesion" of a coating film, which is affected by the environment, a conditional water immersion test and the like are conducted.

However, the low-temperature plasma treatment is 0-1 to 10T as disclosed in Japanese Patent Application Laid-Open No. 133-44965.
When a salt water spray test or a boiling water immersion test was performed after the test was performed under reduced pressure of 0.05 m or more, there was a problem in that the undercoat film peeled off from the interface with the chemical conversion treatment layer.

The present invention provides a low-temperature plasma treatment method that does not have such drawbacks, and a surface-treated metal material subjected to the treatment.

Means for Solving the Problems The present invention provides: 1. A surface-treated metal material obtained by performing low-temperature plasma treatment from above the chemical conversion-treated surface of a metal material that has been subjected to a chemical conversion treatment; A method for producing a surface-treated metal material, characterized in that low-temperature plasma treatment is performed from above the chemical conversion treated surface at an atmospheric gas pressure of 10 Torr or less; 3. From above the chemical conversion treated surface of the chemically treated metal material, the atmosphere is Gas pressure 0.001~0. This is a method for producing a surface-treated metal material, characterized in that low-temperature plasma treatment is performed at I Torr and discharge power of 100 - or more.

action The present invention will be explained in detail below.

There are no particular restrictions on the metal material that can serve as the base material for the surface-treated metal material of the present invention, that is, the pre-coated metal material, but cold- or hot-rolled steel materials, steel sheets plated thereon, such as galvanized steel materials, etc. Steel plates, zinc alloy plated steel plates, lead plated steel plates, lead alloy plated steel plates, aluminum plated steel plates, aluminum alloy plated steel plates, nickel plated steel plates, tin plated steel plates, chrome plated steel plates, etc., as well as stainless steel materials, aluminum or aluminum alloy materials, titanium Alternatively, a titanium alloy material or the like may be used.

However, as will be described later, the effect of plasma treatment is limited to the very surface layer of the film coated with these metal materials, so the effects of the present invention are not affected by any of these metal materials. do not have.

First, chemical conversion treatment is performed on these metal materials. This chemical conversion treatment is performed to improve the corrosion resistance of the metal plate and the adhesion of the coating film. For example, zinc phosphate treatment,
Examples include iron phosphate treatment, chromate treatment, composite oxide film treatment, heavy metal substitution treatment, and silane coupling treatment.

In this way, a low-temperature plasma treatment is applied to the chemical conversion treated surface from above.For example, when using a plasma treatment apparatus as shown in FIG. , for example argon (Ar)
, nitrogen (N2), helium (He), or a mixture of two or more of these gases.

In addition, when creating a gas atmosphere containing oxygen molecules, oxygen (02
), a mixed gas of oxygen and nitrogen, a mixed gas of oxygen and helium, etc.

Furthermore, as the atmosphere, acrylic acids such as acrylic acid (AA), methyl methacrylate (HMA), hydroxyethyl acrylate (HEA), and hydroxyethyl methacrylate (OEMA) can also be used.

However, irrespective of the type of atmospheric gas as described above, ultraviolet rays are generated along with plasma generation, thereby modifying the surface layer of the chemical conversion treatment layer and improving adhesion.

At this time, the pressure of the atmospheric gas is 10 Torr or less, preferably (Pool ~ 0.1 Torr), and by performing plasma treatment under this condition, good salt water resistant adhesion or boiling water resistant adhesion, that is, secondary adhesion is achieved. It also improves the stain resistance of the coating film.

However, the gas pressure is 0. Below I Tart,
Generally, a high treatment effect cannot be obtained because the concentration of active species generated in a low-temperature plasma atmosphere is not sufficient. Therefore, by applying a high power of 100111 or more, even if the concentration of active species is low, it can be efficiently processed. Stable plasma can be generated, and the time required for the treatment effect to appear can be, for example, within 10 seconds.

On the other hand, if Q, I Torr is exceeded when processing is attempted in a short time, the gas concentration is too high and plasma cannot be generated efficiently.

Furthermore, when the treatment is performed under low pressure and high power, the surface is activated, resulting in better adhesion, and particularly excellent performance in secondary adhesion.

Examples of the plasma processing apparatus used in the production of the products of the present invention or the method of the present invention include discharge type apparatuses such as high-vacuum internal electrode type, induction type, and microwave (2450 MHz) direct type. An example of this is shown in Figure 1, which shows a cross-sectional view of an internal electrode type device for plasma treatment on the surface of a metal material that has undergone chemical conversion treatment. Type Pelger, 3 is a metal material after chemical conversion treatment, 4 is an insulator,
5 is a metal stand, 6 is a metal base, 7 is a needle valve, 8
1 is a vacuum system, 9 is a matching network, 10 is a vacuum pump, and 11 is a high frequency power source.

In order to manufacture the surface-treated metal material of the present invention, the metal material having the chemical conversion coating on the surface layer is placed in a processing apparatus, for example at position 3 in FIG. 1, and the internal pressure is at least 0.
．． The atmosphere is evacuated until the pressure is less than 1 Torr, preferably 0.001 Torr or less, and then gas is introduced to adjust the atmosphere to a predetermined pressure of 0.001 to 0.1 Torr.

Then, by applying appropriate discharge power (about 100 to 40") to the electrodes using a high frequency (about 103 to 10" Hz) power source and performing low-temperature plasma treatment, a coating process is performed after that. A precoated metal material having a coating film with significantly improved adhesion as well as secondary adhesion can be obtained.

What is modified by this plasma treatment is the surface layer of the chemical conversion treatment layer and does not affect the base material, so the same effect can be obtained regardless of the base material described above.

Note that the metal material subjected to the low-temperature plasma treatment of the present invention is usually used after being applied with an undercoat, a topcoat, etc.

Methods for applying the undercoat resin onto the metal material include roll coach ink, curtain flow coating, spraying, dipping, electrostatic coating, etc., but are not particularly limited.

As the undercoat, commonly used paints such as polyester, acrylic, epoxy, vinyl, alkyd, urethane, fluorine, silicone, polyethersulfone, and melamine paints can be used. It is not limited to.

Furthermore, as the top coat, the same resin as the base coat can be applied using the same method, and there is also a method of laminating a resin film. The film used in this case is
Possible materials include, but are not limited to, polyester, vinyl chloride, polyethylene, polypropylene, fluorine, etc.Also, a film adhesive may be used between the primer paint and the resin film, This adhesive is also included in the top coat.

Example: Electrolytic galvanized steel sheet with a thickness of 0.8 mm was treated with zinc phosphate (Palpond 3113, manufactured by Nippon Parriki Rising Co., Ltd.)
(Coating weight: 3 g/2 squares) was subjected to low-temperature plasma treatment using the plasma treatment apparatus shown in FIG.

The processing conditions are shown in Tables 1 to 6, and the common conditions were that the frequency was 13.58 MHz, the power output was 300 W, and the processing time was 5 seconds.

After applying the primer paint, it was allowed to cure and an adhesion test was conducted. Adhesion is checked initially (-next) by a base plate test.
After immersion in boiling water for 2 hours (secondary).

The test was carried out by Erichsen test of 71 fat extrusion.

The evaluation was performed by peeling off the tape, and if all of the remaining squares out of 100 squares remained and the score was 0.50 or less, it was expressed as x.

As a result, the gas pressure is 0. Those exceeding I Tart have poor adhesion to boiling water, and similarly, those with low electric sound output also have poor adhesion to boiling water.

Effects of the Invention The present invention is a metal material subjected to chemical conversion treatment, and a method thereof in which the surface of the treated layer is treated with low temperature plasma, and the obtained surface-treated metal material has significantly improved adhesion. There is. Especially 0.001~0.1 Torrc
7) By performing high output (electric power) processing within a range, it is possible to obtain processing effects in a short time with low gas consumption.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional explanatory diagram of an internal electrode type device for plasma-treating the surface of a chemically treated metal material. 1.--Electrode plate, 211-.Glass type Pelger 3.Φ
- Workpiece, 4... Insulator, 5... Metal stand, 6...
φ Metal base, 7-@・Needle valve, 8-Yu・Vacuum system, 911・Matching network, 10・Vacuum pump, 1111・High frequency power supply.

Claims (3)

[Claims] 1. A surface-treated metal material obtained by subjecting a chemically treated metal material to low-temperature plasma treatment from above the chemically treated surface. 2. A method for producing a surface-treated metal material, which comprises performing low-temperature plasma treatment from above the chemical conversion-treated surface of the chemically-treated metal material at an atmospheric gas pressure of 10 Torr or less. 3. A method for producing a surface-treated metal material, characterized in that low-temperature plasma treatment is performed from above the chemical conversion-treated surface of the chemically-treated metal material at an atmospheric gas pressure of 0.001 to 0.1 Torr and a discharge power of 100 W or more. .