Method for preparing polyurethane enamelled wire paint allowing for direct welding without weld slag

Abstract

The invention relates to a method for preparing polyurethane enamelled wire paint allowing for direct welding without weld slag, which is to synthesize the polyurethane enamelled wire paint by using polyester polyol resin, polyurethane sealed resin, a solvent and a catalyst, wherein the used amount of the polyester polyol resin and the used amount of the polyurethane sealed resin are regulated according to the ratio of sealed isocyanate group to hydroxyl, and the weight ratio of the sealed isocyanate group to hydroxyl is 1.0 to 1.6; the used solvent comprises one or several of methylphenol, dimethyl phenol, phenol, solvent oil and dimethylbenzene; and the used catalyst comprises one of zinc isooctanoate, dibutyltin dilaurate and 576 catalyst which accounts for 1 to 5 percent of the solid component of the enamelled wire paint. After being coated with the polyurethane enamelled wire paint, the enamelled wires are free from weld slag in soldering.

Description

technical field [0001] The invention relates to a preparation method of wire enamel, in particular to a preparation method of polyurethane wire varnish for direct welding without welding slag. Background technique [0002] Enameled wire is an essential material for electrical and electronic products. At present, according to the type of conductor, enameled wire includes copper enameled wire, aluminum enameled wire, copper-clad aluminum enameled wire, etc. No matter what kind of enameled wire, it must use enameled wire enamel as the insulating layer. [0003] Polyurethane wire enamel has direct solderability, which is not found in other enameled wire enamel, that is, when the enameled wire coated with it is to be soldered, it can be directly soldered without removing the paint film. This is a unique property of polyurethane structure. Under high temperature conditions, the polyurethane polymer structure of the paint film will decompose and break into small molecules, and the ...

AI Technical Summary

Problems solved by technology

However, at present, the enameled wire coated with polyurethane enameled wire varnish in our country will produce welding slag during direct welding (as shown in Figure 2), which will cause problems such as "virtual welding". It prevents the enameled wire from passing through the small hole on the circuit board, making it impossible to automate production and affecting production efficiency

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