| With the progress of the times, the people's awareness of the self-security, environmental protection and energy saving has improved steadily, the pollution-free environmentally friendly coatings with non-contamination, non-toxicity, low VOC and non-skin irritation received increasing attention. UV-curable waterborne coating has advantages of saving energy, protecting environment, safety and construction convenience, and has become one of the main development direction of green coating.In view of the UV-curable waterborne epoxy acrylic resin having the disadvantages of high brittleness and poor flexibility of curing film in this paper, high flexibility UV-curable waterborne epoxy acrylic resin was synthesized by dimer acid, epoxy resin, acrylic acid and maleic anhydride. The research results showed that the reaction rate of synthetic modified resin was higher, when the experimental synthesis of modified resin divided into three steps, the reaction temperatures remained at 90 ? at the first step and then increased to 110 ? at the second step; the method of temperature subsection was adopted, the temperature was raised to 70 ? after the reaction time reached forty minutes at 60 ? at the third step. The catalyst was N, N-dimethyl benzyl amine and the dosage of catalyst was 1%. When the mole ratio of E-51, dimer acid and acrylic acid was 10:2:8, the film flexibility was from 15 mm to 2 mm, the resistance height was from 10 kg·cm to 50 kg·cm, the comprehensive performance of resin and film was excellent. The structure of the synthesis modified resin was characterized by FT-IR, which the results showed that the epoxy group and carboxyl, hydroxyl and maleic anhydride generated reaction, and indicated that object product was obtained.Itaconic acid modified UV curing waterborne epoxy resin was synthesized with dimer acid, epoxy resin, itaconic acid and acrylic acid and other materials. The results showed that the mole ratio of acrylic and itaconic acid was 1:1, the solid content was 80%, the neutralizer was 2-(dimethyl amine) ethyl acrylate, the neutralization degree was in 80% ~ 90%, the photoinitiator was 1173 and the dosage of photoinitiator was 5%, the obtained water-based resin had yellow transparent appearance, good storage stability and the coating film lasted up to 8 months, the paint film curing time of about 30 s, the pencil hardness was 4 H, the adhesion level was 0, the flexibility was 2 mm and the resistance height was 50 kg·cm, the comprehensive performance of resin and film was excellent.The organic fluorine modified epoxy resin was synthesized from fluorinatedacrylic monomer and epoxy resin, the organic fluorine modified UV-curable waterborne epoxy resin was synthesized through the reaction of fluorinated-acrylic monomer rand epoxy resin and dimer acid, acrylic acid and itaconic acid. The research results showed that the fluorinated-acrylic monomer improved the resistance to water and the hydrophobicity of UV-curable paint film, the water absorption of paint film fell to 3.694% and the water contact angle rose to 92.56° with the dosage increase of HFMA. The structure and properties of the resin were characterized by FT-IR and TG, which found that the perfluorinated alkyl chain segment was grafted to the resin matrix and the thermal stability of the HFMA modified paint film was improved. The introduction of HFMA extended the curing time of the paint film and had some influence on the mechanical properties of the paint film. Comprehensive considering the water resistance and mechanical properties of the paint film, when the dosage of BPO was 4%, the quality ratio of E-51 and HFMA was 4:1, the comprehensive performance of resin and paint film was excellent. |
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