JPS583964A - Formation of insulation layer which permits melt- spraying of metal - Google Patents

Abstract

PURPOSE:To form an insulation layer that permits melt-spraying of metals by coating adhesives, etc. on the surface of the insulation layer coated and formed on the surface of a base material after curing of said layer and coating anchor materials before the adhesives, etc. set. CONSTITUTION:An insulation layer 2 of 50- several hundreds mum film thicknesses consisting of adhesives of epoxy type or the like is coated on a base material 1 of copper (alloy), etc. Upon curing of the layer 2, adhesives or paint 2-1 is coated on the layer 2 to about 250mum film thickness and before the adhesives or the paint 2-1 sets, particles 3 as anchor materials are sprayed, then the adhesives or the paint 2-1 is allowed to set. The sprayed particles 3 settle slightly during the course of the setting of the adhesives, etc. 2-1, but the settling beyond a constant level is prevented by the already cured layer 2. This yields the layer 2 which prevents the decrease in the adhesive force of melt spraying owing to sinking of the particles 3 into the layer 2 and permits melt spraying of metals. Alumina, sand, metallic oxides or the same metals as melt spraying materials are used for the anchor materials.

Description

[Detailed description of the invention] The present invention relates to a method for forming an insulating layer that can be metal sprayed.

A method of forming an insulating layer on the surface of the base material and making it possible to spray metal on that surface is to apply an adhesive or paint to the surface of the base material, and then apply oxidized metals such as alumina or sand or a thermal spray material on top of it. A method is known in which identical metal particles (hereinafter simply referred to as particles) are dispersed as an anchor material and the metal is thermally sprayed onto the surface of the particles.

If the base material is a very large structure such as a ship or offshore structure, a series of these operations may involve upward or vertical operations. In this case, an air can is generally used to disperse the particles. However, this method has the following major drawbacks.

Figure 1 shows the conventional method, in which a base material 1 is coated with an insulating layer 2'.
f: It is a cross-sectional view of a product coated and further sprinkled with particles.

Figure 1 (a) shows the entire building immediately after the particles have been sprayed. That is, the particle filter covers almost the entire surface of the insulating layer 20. (b) is a diagram after 'fc' after the insulating layer 2 is cured. What differs from the ajO diagram in this diagram is that particle 3 has sunk into the insulating layer.It is unclear why such a phenomenon occurs on the vertical plane, but it is a type of This is thought to be due to capillary phenomenon, that is, the opening of particles of the insulating material before curing increases.

On the other hand, experimental results have shown that the adhesive strength after thermal spraying is stronger as the surface of the particles 3 protrudes more from the surface of the insulating layer.

Therefore, in the conventional method in which most of the particle surfaces sink into the insulating layer as shown in FIG. 1 (1)), the adhesion force of thermal spraying is significantly reduced.

As described above, with conventional methods, the adhesion force of thermal spraying decreases, making it difficult to obtain a stable and constant strength, resulting in a lack of product reliability.

The present invention relates to a method for forming an insulating layer that can be thermally sprayed with metal, which prevents a decrease in adhesion of thermal spraying due to the embedding of the particles in the insulating layer, and is characterized by the following points.

1) In the conventional method, an insulating layer is applied and particles are scattered before it hardens, but this method is discontinued and the insulating layer is hardened.

2) Apply a thin layer of adhesive St for adhering particles onto the cured insulating layer, and scatter particles onto the surface before this layer is cured.

3) Because the adhesive film is thin, particles do not sink beyond a certain level. That is, the sinking stops at a certain point blocked by the surface of the hardened insulating layer, and the adhesive etc. hardens in that state.

4) Therefore, it becomes possible to expose a large number of particles to the surface, and metal spraying with stable adhesion becomes possible.

That is, in the present invention, an insulating layer is applied and formed on the surface of a base material, and after the insulating layer is cured, an adhesive for bonding the anchor is applied to the surface, and the adhesive is applied before the adhesive is cured. The present invention relates to a method for forming an insulating layer capable of being sprayed by metal, characterized by completely dispersing an anchor material on the surface.

Examples of the base material in the present invention include metal materials having a different potential from the thermal spraying material, but when the thermal spraying material is copper or copper alloy to prevent contamination by marine acids, the outer panel of a ship,
That is, steel materials can be cited as an example.

Examples of the insulating layer in the present invention include epoxy-based, polyester-based, alkyd-based, and chlorinated rubber-based paints, and adhesives such as epoxy-based, urethane-based, and rubber-based adhesives, and the film thickness is 50 to several hundred μm. It is.

As the anchor adhesive in the present invention, it is preferable to use the same paint or adhesive as the insulating layer, adjust the viscosity to 50 to 70 poise, and uniformly apply the film to a thickness of about 250 μm.

The anchor material in the present invention is alumina, as in the conventional method.
The same metal as the metal oxide or thermal spray material, such as sand, silicon carbide, emery, carnet, silica stone, etc., is dispersed as particles 2 with a diameter of 50 to several hundred μm.

The present invention can be applied to all products in which a metal material is thermally sprayed through an insulating layer, such as application to the outer panels of ships and the like for antifouling purposes.

The method of the present invention will be specifically explained using FIG. 2.

An insulating layer 2 is applied to the base material 1, and after the insulating layer is cured, a thin layer of adhesive or paint 2-1 is applied. The particles 5 are sprinkled before the adhesive or Fi paint (hereinafter abbreviated as adhesive, etc.) has yet to harden. FIG. 2(a) shows a cross section immediately after dispersing the particles. Further, FIG. 2(b) shows a state in which the adhesive and the like have hardened.

In the process of curing, the three-particle adhesive 2-1 dispersed in FIG. 2 (1)) settles slightly, but the insulating layer 2, which has already been cured by 1°, prevents settling beyond a certain level. Therefore, the surface area of the particles protruding from the surface of the adhesive, etc. is maintained at the same level or slightly smaller than the state shown in FIG. 2(a).

In the conventional method, as shown in (1) in Fig. 1, the particles 3 serving as the anchor material sink into the insulating layer 2 such as adhesive, which completely reduces the adhesion force of thermal spraying. According to this method, it is possible to reliably maintain insulation with the base material and prevent sinking of the particles serving as the anchor material, thereby improving the thermal spray adhesion strength to the surface layer.

In addition, based on the results of the experiments conducted on the site, it can be said that the following construction method is appropriate.

The film thickness of adhesive etc. is related to the particle size, and when the film thickness before curing is around 250 μm, the particle diameter is 200 μm to 500 μm.
Approximately μm is appropriate. In order to uniformly apply an adhesive or the like to a large area with a constant thickness, spray painting is reliable and quick, but it is necessary to adjust the viscosity of the adhesive or the like. This is because by lowering the viscosity to a certain level, the state discharged from the spray nozzle tends to be atomized, and by controlling the moving speed of the spray nozzle, the thickness of the coating film in one bath can be adjusted. When using a polyester-based adhesive, the viscosity can be adjusted to 50 to 70 poise, making it easier to control the film thickness, and the phenomenon of blurring is not observed even when particles are dispersed. The viscosity may be adjusted by controlling the temperature, but since this has disadvantages such as changing the curing time and not being able to maintain a constant temperature, it is better to control the viscosity using an appropriate solvent.

[Brief explanation of the drawing]

The attached drawings are cross-sectional views illustrating a method for providing an insulating layer on a base material that can be sprayed by metal spraying. Before layer hardening, (
b) shows the state after curing, FIG. 2(a) shows the state before hardening of the Fi adhesive, and FIG. 2(b) shows the state after hardening. Sub-agent 1) Meifuku agent Ryo Hagiwara - (7) Fang 1 figure Fang 2 figure

Claims (1)

[Claims] An insulating layer is applied and formed on the surface of the base material, and after the insulating layer is cured, an adhesive for adhering the anchor material is applied to the surface.
. A method for forming an insulating layer capable of metal spraying, characterized in that the anchor material is completely spread on the surface of the adhesive before it hardens.