| Recently, with the rapid development of industrialisation and the increasing pressure of environment, traditional coating industry had caused bad impact on the human body and the environment because of the large use of volatile organic solvents,which seriously restricted its application and development prospect. As a new green energy saving environmental coating, UV-coating has the advantages of low emission of VOC, high curing efficiency and excellent product performance, and it was noticed widely. Meanwhile, entering into a new period of coating industry,waterborne UV-coatings appeared under the background of high level demand on UV-coating. It used the water as diluent instead of active diluent and this solved the problem of bad smell caused by the use of active diluent.Epoxy acrylate resin is one of the most widely used UV-cured oligomers,which has a low production cost and good performance of paint film, but it also has lots of disadvantages. for example, epoxy acrylate has a large viscosity and the paint film has a bad flexibility. Therefore, it makes a great sense to explore the modification of epoxy acrylate and develop a UV-curable waterborne epoxy acrylate with good performance.A new type of low viscosity water-borne UV-curable epoxy acrylate resin was synthesized by ring opening esterification reaction of epoxy compounded by active epoxy diluent and acrylic acid, and the hydrophilic groups was introduced by the esterification reaction of maleic anhydride and resin, and the water-borne UV-curable epoxy acrylate was synthesized after neutralization of organic alkali. The results showed that the optimal conditions for the synthesis of epoxy acrylate, and the reaction rate and conversion of synthetic resin was higher when the reaction temperature was 95?, the catalyst was N,N-dimethyl benzyl amine and the dosage of catalyst was 1%. Epoxy acrylate resin achieved water-borne by the introduction of maleic anhydride, the optimal reaction temperature was between 70?and 75?, andthe resin can't get water-borne until the dosage of maleic anhydride reached more than 0.6; The introduction of PEGGE significantly reduced the viscosity of synthetic resin and improved the performance of film; when the ratio of PEGGE and epoxy was1:3, UV-curable water-borne resin viscosity was as low as 633 mpa·s, the rate of visocity reduction rate reached as high as 95.35%; when the neutralizer was2-(dimethyl amine)ethyl acrylate, the neutralization degree was 90%, the solid content was 80%, and the dosage of photoinitiator was 5%, resin had a good viscosity and appearance, and the film had an overall performance when the curing time reached20 s, the hardness was 4H, the film adhesion level reduced from phase 5 to 0, the flexibility improved from 15 mm to 2 mm, the resistance height significantly improved.The structure of the synthetic resin was characterized by FT-IR, and the peak value corresponding to the target group appeared, which indicated that object product was obtained.The organic silicon modified UV-curable was synthesized by the further esterification reaction of KH560 and epoxy acrylate. The rusults showed that the film's water resistance and hydrophobicity was improved by the introduction of silicon. The water absorption of paint film fell down to 10.19%, the water contact angle rosed to 78.43° with the increasing dosage of KH560. It proved that the KH560 was contacted to the structure of resin by using FT-IR and TG, and the film's heat resistance was dramatically improved with the introduction of silicon. The effect of dosage of KH560 on the curing time and mechanical properties of the film were discussed. It showed that the curing time was prolonged. The film achieve great performance when the dosage of KH560 was 20%, the film's hardness was 6H, the film adhesion was 0, flexibility was 2mm, the resistance height was 50kg·cm and the gel content improved a lot. |
PDF Full Text Request