Low temp. solidifeed resin emulion used for cathode electrolytic coating

Abstract

The present invention relates to a low-temp. soldified resin emulsion for cathodic electrophoretic coating. It is made of 20-70% of modified epoxy resin, 5-50% of polyamine and 10-30% of closed polyisocyanate which can completely declosed at 120-140 deg.C, through the processes of chemical reaction, mixing, neutralizing with organic acid and dispersing in water, in which the modified epoxy resin is made up by using epoxy compound and polyhydroxylated compound and adopting epoxy resin synthesis method under the action of catalyst, its molecular weight is 300-3000, and the pure solid weight ratio of epoxy compound and polyhydroxylated compound is 5-8 / 2-5. The described epoxy compound is bisphenol A diglycidyl ether and glicidyl ether containing flexible chain or glycidyl ester, and the polyhydroxylated compound is bisphenol A and polyhydroxylated compound containing flexible chain.

Description

technical field [0001] The invention relates to a resin emulsion for cathodic electrophoretic paint cured at low temperature. Background technique [0002] In cathodic electrophoretic coatings, resin emulsion is the main film-forming substance, which determines the film performance of cathodic electrophoretic coatings, and has always been the focus of people's research and development. Epoxy cathodic electrophoretic coatings are widely used because of their excellent corrosion resistance. The resin emulsion used for this type of coating is made by aminating epoxy resin to open the ring, then adding blocked polyisocyanate for mixing, neutralizing with organic acid, and dispersing in water. In order to ensure good paint film performance, the curing temperature is generally 160-200°C. This has caused many practical problems, such as high energy consumption resulting in waste of resources and increased costs; it cannot be applied to heat-sensitive materials; the paint film has...

AI Technical Summary

Problems solved by technology

As a result, many practical problems have been caused, such as high energy consumption resulting in waste of resources and increased costs; it cannot be applied to heat-sensitive materials; the color of the paint film is single, and it cannot take into account the decorative properties of the paint film, etc.