| A cationic epoxy resin as matrix and acrylic monomers as graft copolymer was synthesized by the graft copolymeri/ation. Then the cathodic electrodeposition coating was obtained by sell-emulsion process. The formula, synthesis, electrophoretic coating process and the properties of paint films were studied in detail.In this paper, a kind of self-crosslinking cathodic electrodeposition coating was prepared, which based on epoxy resin as matrix with acrylic monomers grafting and copolymerization. The reaction mechanisms were discussed, and the influences of the stability of the water dispersion were concluded. The factors affecting the water dispersion stability and film properties were molecular weight of epoxy resin, monomer A dosage, diethanolamine content, neutralizing degree, solvents, emulsification process and initiator ratio. The self-crosslinking system also was researched. The measuring methods and tools, such as FT-IR, Laser particle Analyzer and TEM were used. The experimental results show that E-20epoxy resin is modified by acrylic monomers, such as monomer A, monomer B, monomer C, BA, MMA. The addition of monomer A can improve the stability, whose quality is10%of the total monomers quality. The quality of monomer B and monomer C as curable monomers respectively are5%and5～10%of the total monomers quality, which not only improve film properties, but also enhance emulsion stability useful for dispersion. Otherwise, the quality of initiator is3%of the gross weight.The electrophoretic coating process is a very complicated process. This experiment has studied electrophoretic technology. The effects of the changes of electrophoretic parameters on film appearance and properties are very important. In this paper, the preparation of the metal substrate and the effects of parameters of electrophoretic technology were mostly investigated, which contains voltage, temperature, time, solid content, pH value on the properties of paint films... |
