Study On The Coating Of Acrylate Resin Modified By Nano-SiO₂ For Pressing Paper-base Laser Holography Image

Research and development of the coating for laser holograph is important for commodity anti-counterfeiting. A coating of acrylate resin was prepared for pressing paper-base laser holography in this thesis. The coating was modified by introducing TPGDA and nano- SiO₂ in order to improve the coating performances of wear resistance, heat-resistance, weather-resistance and water-resistance according to the require of pressing laser holography image. The major contributions of this thesis are described as follows:1. The acrylate resin was synthesized by co-polymerization of four monomers: Methyl methacrylate(MMA), butyl methacrylate(BMA), butyl acrylate(BA) and methacrylic acid(MAA). The optimal synthesis parameters of the resin processing are that ratio of MMA:BMA:BA:MAA is 60:30:5:5, the organic solvent is butyl acetate, the reaction temperature is set between 120-126℃, the reaction time is 5h, the dosages of Initiator, inhibitor and TPGDA are 1.5 % , 0.05 % and 2 % of the weight of all monomers respectively. The structure and the glass transition temperature of this resin were studied by the means of IR DSC. The result showed that the four monomers reactivity completely, the glass transition temperature reaches 74.83℃.2. The surface of Nano-SiO₂ was modified by silane coupling agent. The modified nanoparticles was detected by the means of IR, laser nanometer measurement and SEM. The result showed that nano- SiO₂ is dispersed uniformly in the organic solvent and its size is about 100nm, the coating is smooth. The rigidity, viscosity, wear-resistance, heat-resistance, weather-resistance and water-resistance performances of the coating are improved by adding nano-SiO₂.3. The paper with coating was pressed to produce laser holography images, the press temperature is increased by adding nano-SiO₂. The diffraction efficiency of the laser holography images were detected, the optimal dosage of nano-SiO₂ is 2 % (wt %) of the coating. the result showed that the diffraction efficiency reaches 7.2 %, which is good enough for the laser holography anti-counterfeiting imaging.