JPS59212254A - 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.

In the case of, for example, a silencer for an internal combustion engine, where a painted metal material is intermittently exposed to high temperatures, rusting of the metal material and peeling of the paint cannot be avoided even if a heat-resistant paint is applied. The causes of this are various and complex, but the main cause is that during heating, for example, side chain organic substances in silicone resin are heated and turn into gas, causing swelling between the metal material and the paint layer, causing the paint film to deteriorate. The idea is to destroy it.

Also, along with this phenomenon, iron oxide (Fe) is deposited on the surface of the metal material.
2O3'j or Fe304) is produced. However, the problem with such conventional methods is that the paint itself is destroyed by intermittent heating, and the problem with paint films applied to objects subject to severe thermal conditions has not yet been resolved. .

The present invention was developed in view of the current situation, and the coating itself adheres well to the metal material and does not peel off even when subjected to heat, etc., and the metal material itself does not rust. This is how it was designed. The structure of the first invention is characterized in that a dendritic plating layer is provided directly or indirectly on the surface of the metal material, and a paint layer is further formed entwined with the dendritic portions of this dendritic plating layer. That is.

As a result of this structure, the paint layer forms a coating film in a state where it is firmly entangled with the dendritic parts of the dendritic plating layer, so even if it is subjected to heating etc., this entanglement prevents it from peeling off easily. This prevents the metal from falling off and ensures a protective layer on the metal surface at all times. Since the surface of the metal material itself is protected by the dendritic plating layer, oxidation of the metal surface material is thereby prevented and rust can be completely eliminated.

Furthermore, the second invention has a structure in which a dendritic plating layer is directly or indirectly provided on the surface of the metal material, and a silicon-based paint layer is formed in a state entwined with the dendritic portions of the dendritic plating layer, Further, colloidal silica is attached to the dendritic portions of the dendritic plating layer.

With this structure, as in the first invention, the dendritic parts of the dendritic plating layer and the paint are tightly intertwined, so that the paint layer does not peel off at all, and the plating layer does not disturb the surface of the metal material. This prevents the oxidation of In addition, 8 in the colloidal silica applied to the dendritic part of the dendritic plating layer
The l-OH group and the 5i-OH group in the paint undergo a dehydration reaction, thereby strengthening the bonding force and preventing corrosion.

<Embodiment of the First Invention> As shown in FIG. 1, this device has a dendritic plating layer 2 formed on the surface of a metal material 1, and further a paint layer 3 formed on the upper surface thereof.

First, the metal material 1 is, for example, mild steel (Fθ), and is a material constituting an outer shell member of a silencer for a motorcycle or the like. The dendritic plating layer formed on this surface is, for example, nickel plating. Of course, when forming this nickel plating, it is better to form the nickel plating layer 2 directly on the surface of the metal material 1, but there is no problem even if an appropriate base plating layer is present. That is, as shown in Figure 3, a nickel plating layer (indicated by reference numeral 21) 'fc without any sulfur component (s) was directly formed on the metal material 1, and then a layer containing a large amount of sulfur component was formed on the upper surface of the nickel plating layer (indicated by reference numeral 21). A nickel plating layer (indicated by reference numeral 22) is formed, and then a dendritic plating layer 2 is formed, and by this method, the corrosion potential of the metal can be changed and the corrosion resistance can be improved. . It goes without saying that this method of forming multilayer plating layers can be applied not only to the embodiments of the first invention but also to the embodiments of their second invention.

The point is that the dendritic plating layer 2 only needs to be applied directly or indirectly to the surface of the metal cable 1. Incidentally, this dendritic plating layer and the nickel plating layer are plated by being immersed in a nickel plating bath according to the conventional method, and the standard thickness thereof is approximately 20 microns or less and several microns thick. (However, there is no limit to the thickness). If we look at the dendritic part 2a of the dendritic plating layer 2 in detail, we can see that it consists of a large number of amorphous protrusions (see Fig. 1).
stomach)). Such a dendritic plating layer 2 may be coated with, for example, a conventionally known heat-resistant paint (unless, of course, the usage conditions are such that it is intermittently exposed to high temperatures, and a heat-resistant paint is not necessarily required as a protective structure for metal materials). The preferred thickness of the coating film is approximately 20 to 35 microns as a standard, but there is no limit to the thickness.
Figure (b)). In this case, the dendritic plating layer 2
The paint layer 3 and the paint layer 3 maintain a strong adhesion state in the dendritic portion 2a. That is, the paint is stuck to the dendritic portions 2a so as to bite into or become entangled with them.

Embodiment of the Second Invention In this device, a dendritic plating layer 2 is formed on the surface of a metal material 1, and furthermore, colloidal silica 4 is applied to the dendritic portion 2a.
is applied, and then a paint layer 3 is formed thereon. As in the previous embodiment, the metal material Fe is made of mild steel, and the dendritic plating layer 2 formed on the surface thereof is used as the metallic material Fe.
is a nickel plated layer. The forming method and the forming thickness are almost the same as those in the previous embodiment, and the thickness of the sinicle plating layer is about 2.5 microns or less.
The thickness should be approximately 10 microns (although there is no thickness limit). After applying nickel plating over the dendritic plating layer according to such a conventional method, it is immersed in a 5-10 percent colloidal silica aqueous solution for about 10-30 seconds.
After being immersed in a stationary state, it is taken out, washed with water, and dried (Fig. 2 (a)). This colloidal silica has a colloidal diameter of about 10-20 millimicrons. After such treatment, a paint layer 3 is formed on the surface.
The coating is applied to a thickness of about 0-A micron (Second
Figure (b)).

Of course, this coating can be done by any appropriate method, such as so-called spray coating, electrostatic coating, or dipping.

In the present invention having such an embodiment, first, 40
In a situation where intermittent heating cycles were repeated in which the metal material was heated at a temperature of 0°08°C for about an hour and then immediately cooled with water, the layer density of the paint layer 3 to the metal rope material l was almost lost. First, no occurrence of rust or cracks was observed.

[Brief explanation of the drawing]

Fig. 1 is a vertical side view showing the first invention of the surface protection structure for metal materials, which is the present invention, Fig. 2 is a longitudinal side view showing the second invention, and Fig. 3 is the first and second inventions. FIG. 7 is a vertical side view showing another example of a method for forming a dendritic plating layer that can be applied to the method of forming a dendritic plating layer. 1; Metal material 2; Dendritic plating layer 2a;
Dendritic m 3; Paint layer 4; Colloidal silica 1st (a) 8th 2nd (1') 3rd 9th,)! Hamari Chinzi (b) Figure (b) Zuzo - Takeshi

Claims (2)

[Claims] (1) A surface of a metal material characterized by having a dendritic plating layer directly or indirectly on the surface of the metal material, and further having a paint layer entwined with the dendritic portions of the dendritic plating layer. Protective structure. (2) providing a dendritic plating layer directly or indirectly on the gold a-cable lunar surface, further forming a silicon-based paint layer entwined with the dendritic portions of the dendritic plating layer, and said dendritic plating layer; A surface protection structure of a metal material made by adhering colloidal silica to the dendritic parts.