JPS6214967A - Fluidized immersion coating method - Google Patents

Abstract

PURPOSE:To enhance close adhesiveness and cracking resistance while dispensing with plating, by performing fluidized immersion coating by utilizing the remaining heat of baking and drying in electrodeposition painting. CONSTITUTION:In the corrosion-proof/electric insulating treatment of a member comprising each of various metal material such as steel, copper, aluminum or an alloy thereof, said member undergoes the processes of degreasing washing phosphate treatment washing electrodeposition painting washing fluidized immersion painting curing. Herein, a cationic epoxy paint is used in electrodeposition painting and baking and drying after washing are performed at 180-200 deg.C and, immediately after baking and drying, the member is immersed in a fine powder comprising an epoxy resin or a polyure thane resin brought to a suspended state by blowing air in said powder and perform painting.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to fluid immersion, which is applied for corrosion protection and electrical insulation of members formed from steel, copper, copper alloys, aluminum, aluminum alloys, and various other metal materials. This relates to a painting method.

[Technical background of the invention and its problems] Conventionally, the fluidized dip coating method uses fine powder of epoxy resin, polyester resin, polyamide resin, etc. for the purpose of corrosion protection and electrical insulation of members formed from metal materials. Air is blown into these fine powders to make them suspended, and
The resin was applied by dipping the member heated to 80 to 200°C.

By the way, the quality of adhesion of a painted film is related to the cracking property of the film. Therefore, in order to improve this adhesion, silver plating or nickel plating has been applied as a pretreatment. In particular, this pretreatment has become essential for copper and copper alloys.

However, if fluid dip coating is applied after plating, the plating may blister when preheated to 180 to 200°C, and if fluid dip coating is applied to the blistered material, the coating will deteriorate. It has the disadvantage that adhesion strength and crack resistance are extremely low.

On the other hand, if fluidized dip coating is applied without plating, the parts will be oxidized after rust removal and during preheating at 180 to 200°C, and the generated metal oxides will have poor adhesion to the base of the parts, resulting in poor adhesion strength and It was not possible to obtain a film with excellent crack resistance.

The generally employed fluidized dip coating process is as follows.

Degreasing → rust prevention → washing → plating (may be omitted) → washing → drying → drying → preheating → fluidized dipping (ilVc → hardening [Object of the invention] The present invention was made in view of the above-mentioned circumstances. The object of the present invention is to provide a fluidized dip coating method which improves adhesion and crack resistance, and improves corrosion prevention and electrical insulation functions.

"Summary of the Invention" The present invention involves forming a film on a material to be coated by electrodeposition coating, heating and drying it, thereby eliminating the need for plating and improving adhesion and crack resistance. It is designed to improve sex.

[Example of the Invention] Hereinafter, an example of the fluidized dip coating method of the present invention will be described. Note that this example is an example applied to copper material, and the steps are as follows.

Degreasing → Water washing → Phosphate treatment (sometimes omitted) → Water washing → Electrodeposition painting → Water washing → Baking drying → Fluid immersion painting → Hardening. A cationic epoxy paint is used for painting.
After washing with water, baking ζJ drying is performed at 180 to 200°C, and immediately after baking and drying, it is coated by immersing fine powder of epoxy resin, polyurethane resin, etc. in a suspended state by blowing air into it.

Therefore, the residual heat from baking drying in electrodeposition coating can be effectively used for preheating the conventional fluidized infiltration coating method.

The following table compares the results of the above examples with a conventional fluidized infiltration coating method in which nickel plating was pretreated.

(Hereafter, blank space) As is clear from this table, the adhesion strength and crack resistance of the film were significantly improved. This is because the Erikvin value of the film coated by electrodeposition as a pretreatment is 6 to +2 mm, which is highly flexible, and the film functions as a stress relaxation layer between the metal base of the component and the fluidized dip coating. be.

In addition, electrodeposition coating is electrochemically deposited as a resin onto the substrate of part H, and because the coating is done in proportion to the electric current due to the electrical resistance of the deposited resin, it can be applied even in complex shapes or at seams. Extremely good throwing power and adhesion can be obtained even at the edges.

Furthermore, there is also the advantage that residual heat from baking drying after electrodeposition coating can be used directly for preheating the fluidized immersion mK.

[Effects of the Invention] Since the present invention is configured as described above, it eliminates the need for pre-treatment plating, improves adhesion and crack resistance, does not reduce adhesion even with complex shapes, and provides corrosion protection. It can also improve electrical insulation properties.

Claims (1)

[Claims] A fluid-dip coating method characterized by forming a film on a material to be coated by electrodeposition, heating and drying, and then applying fluid-dip coating.