Research On The Modification Of UV-curable Epoxy Acrylate Resin

With the improvement of people’s life quality requirements, as well as the increasingly stringent environmental regulations, UV-curable coatings, water-based UV-curable coatings, are the direction of the current environmental protection coating.This study focuses on the toughening of UV-curable epoxy acrylate resin. At first, synthesis a di-ester extender that containing Polyethylene glycol. Then introduced the extender into the EA. From the condition of reaction, different kind of Polyethylene glycol, and optimum curing process was explored. The temperature of Chain-Extension reaction is 65~70°C, catalyst amount of 0.1~0.2wt% of BDMA. Increased the temperature to 90°C at the second step, the amount of MEHQ as an inhibitor 0.1% in the mass of acrylic acid. With the increase of the molecular weight of Polyethylene glycol, the mechanical property, viscosity and glass transition temperature of oligomer will drop. But the flexibility and surface properties will improved. For the UV-curing system containing 10wt% TMPTA and 10wt%HDDA as a reactive diluent, and mixed initiator contain 184 and TPO.The low viscosity epoxy acrylate oligomer was modified by Polyethylene glycol direct. When the molar ratio of Polyethylene glycol and epoxy resin is 1:2, the oligomer with good comprehensive properties. Viscosity of oligomer and inversely proportional to the molecular weight of Polyethylene glycol and the dosage. gloss and elongation of the cured film modified were increased, but will reduce the mechanical property slightly. PEG1000 modified samples with tensile modulus and elongation at break of the relatively high. PCL205 modified sample has higher tensile strength and gloss.In addition, the waterborne polyurethane(WPU) and anhydride modified epoxy acrylates were synthesized. Study on the effects of the introduction of hydrophilic group conditions on system performance, and explored on the optimized curing process. Study results are as follows: In synthesizing WPU segment, the heating temperature was set to 65 ° C, wherein the molar ratio of the hydrophilic chain extender with an MIthan DMPA is 1: 5, when feeding MI excess of 35%. When modified with a WPU of EA, the mole ratio of WPU to EA was 1:3, the reaction temperature was 75 °C. When using maleic anhydride modified EA, by optimizing the feeding way to reduce the degree of discoloration of the system, the reaction temperature was 85 °C, and add anhydride content of 0.5% triethylamine as a catalyst. After the modification, the system was neutralized with triethylamine and 100% neutralized, the temperature is at 55 °C, and adjust the solid content of 40%. Before curing, were added to 5wt% of TMPTA and 4wt% of the mixing initiator. After mixing, drying 30 min at 70 °C, after light curing obtained the film with low water absorption, good flexibility, high gloss.