JPS60131241A - Surface protective structure of metallic blank - 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] The present invention relates to a surface protection structure for metal materials.

- For example, in the case of mufflers for internal combustion engines, where painted metal materials must be exposed to intermittent high-temperature conditions, rusting of the metal materials and peeling of the paint cannot be avoided even if heat-resistant paint is applied. . This cause is complex, but the main cause is □
For example, when heated, side chain organic substances in silicone resin gasify when heated, causing swelling between the metal material and the paint layer and destroying the paint film. Further, at the same time as this phenomenon, iron oxide (Fe2O2 or Fe2O2) is generated on the other side of the metal material, which is the cause of this phenomenon.

The problem with conventional methods, such as red spots, is that the coating itself is flammable and can be destroyed by heating. □Paint applied to the trouble”
Solving the problem with coatings cannot be solved simply by improving the paint. By the way, this anchorman is
Under these circumstances, the paint itself adheres well to the metal ice material, and even if it is heated, it will not peel off, and the metal material itself will not rust. In order to prevent this from occurring, we have devised a novel surface protection structure for metal materials, and have already applied for a patent under the special patent application No. 56 ony'. The purpose of this invention is to further improve the properties of the metal 1 ice according to the present invention.
In the 11i structure, a dendritic plating layer is formed directly or indirectly on the metal material surface, and colloidal silica is attached to the dendritic parts of the dendritic plating layer, and colloidal silica is attached to the dendritic parts. It is made by forming a paint layer mainly composed of silicone resin and aluminum powder that intertwines in good condition.

With this structure, the dendritic parts of the dendritic plating layer and the paint layer are tightly entangled, and the paint layer does not peel off at all, and the plating layer prevents oxidation of the surface of the metal wood. It is.

In particular, even when a metal material subjected to such treatment is applied to a high-heat area, sufficient strength is provided.

Although the theoretical method of farming that produces such an effect is not necessarily clear, when silicone resin-based aluminum powder paint is exposed to a cylinder at temperatures of 300 to 400°C or higher, the organic matter in the silicone resin decomposes. This is presumed to be due to the formation of a ceramic-like inorganic film of skeleton-like silicon oxide (StO2)-aluminum powder. This skeleton-like ceramic (3)-like film is presumed to have a flexible structure because of its skeleton structure.

<Example> In this example, as shown in the drawings, a dendritic plating layer 2 is formed on the surface of a metal material 1, and furthermore, colloidal silica 3 is adhered to this dendritic part 2a, and a paint layer 4 is further applied on top of the dendritic plating layer 2. It is formed by forming. As the metal material 1, mild steel (Fe) is used as an example, and the dendritic plating layer 2 formed on the surface thereof is a nickel plating layer (N1). Of course, in forming this dendritic plating layer 2, it may be formed directly on the surface of the gold jIi4 material 1 as in this embodiment, but it may also be formed, for example, with a lower plating layer interposed therebetween. No problem. In this case, for example, a sulfur-free nickel plating j- is directly formed on the metal material l, then a sulfur-rich nickel plating layer is formed on its upper surface, and then dendritic plating is applied. Form layer 2. By the way, the corrosion potential of the metal can be changed by this method and the corrosion resistance can be improved (4).The thickness of the dendritic plating layer 2 should be less than TTM microns and about several microns thick. However, it can be set as appropriate depending on the performance outside this range. After plating according to the conventional method, the metal material is immersed in a 5 to 10% colloidal silica aqueous solution for about 30 seconds, then pulled out, washed with water, and dried. It's something◆. This colloidal silica 3 has a colloidal diameter ranging from 10 to 100 mm. After such treatment, a paint layer 4 is formed on the surface, and this paint is mainly made of silicone resin and aluminum powder, and typically has a thickness of about 100 to 100 microns. It is painted on the surface. Of course, the thickness of this paint layer can be set appropriately depending on the purpose and the like. Regarding painting methods, spray painting,
Needless to say, an appropriate method such as electrostatic coating or immersion coating may be used. The applied paint may be air-dried to evaporate the solvent or may be baked. In this case, it is preferable that the higher the baking temperature is, the harder the painted surface becomes and the better the adhesion is.

The present invention comprising such embodiments has the following effects. First, in terms of heat resistance and adhesion to the metal composite surface, appropriate I from 3OO to aso C is used.
Rw! As a result of testing by heating for 1 hour at each test, a sufficiently stable adhesion state was observed at 5SOC, which was the highest test temperature. As mentioned above, this adhesion was tested at a baking temperature of 150 DEG to 450 DEG C., and it was found that the adhesion improved as the baking temperature increased. Furthermore, regarding the hardness of the m film, an increase in hardness l was observed as the baking temperature increased. As for resistance, as a result of conducting a cast test according to the RXE standard, no occurrence of so-called red rust was observed. In the Ikuru test, the color of the cormorant's paint color changed.
The blood stain situation was also completely unchanged. Yet another Cass 2? In the cycle test, slight fading of the paint color was observed, but the condition of the paint film remained unchanged, and the metal material was sufficiently preserved.

As described above, the present invention obtains a strong ceramic-like surface coating by applying a paint mainly composed of silicone resin and inorganic aluminum powder to a nondendritic plating layer with colloidal silica attached. This, together with the presence of the plating layer, provides a strong protective structure of the metal material.

[Brief explanation of drawings]

The drawing is an enlarged sectional view showing the surface protection structure of a metal material according to the present invention. l; Metal rope material 2; Dendritic plating layer 2a; 44 branched portions 3; Colloidal silica 4; Paint layer (7) addition 4-) 17-

Claims (1)

[Claims] Forming a dendritic plating layer directly or indirectly on the surface of the metal material, further adhering copoidal silica to the dendritic portions of the dendritic plating layer, and attaching silicone resin to the dendritic portions in a state entwined with the dendritic portions, A surface protection structure for metal materials characterized by the formation of a paint layer consisting mainly of aluminum powder.