Material Of Waterborne UV-curing Resin's Synthesis And The Capability And Application

Waterborne UV-curing systems have advantages of non-contamination, non-toxicity, non-skin irritation and safety of production, and become an attractiveresearch and application areas of UV-curing systems.In this paper two series of waterborne UV-curing resins were prepared fromdifferent materials. Epoxy acrylic resin (EA) was synthesized from biphenol A epoxyresin and acrylic acid, waterborne UV-curing Epoxy acrylic resin (EB) wassynthesized through the reaction of EA and malefic anhydride. A new kind ofwaterborne UV-curing polyurethane acrylate (PUA) ionomer prepared from toluene-2,4-diisocyanate (TDI), poly(propylene glycol)(PPG), 2-hydroxyethyl methacrylate(HEMA) and a compound (DMPA) which had a carboxy and two hydroxyl groups.Fourier transform infrared (FTIR) spectra demonstrated the formation of the abovetwo kinds of resins. Both the optimum conditions of the synthetic reactions and theeffects such as hydrophilic group content, neutralization degree and resinconcentration on emulsion were studied on the above mentioned resins. The effects ofthe type and concentration of photoinitiator, neutralization degree, neutralizationagent type, drying and structure of the prepolymers on curing rate were discussed indetail.The properties of UV-cured films of PUA were also determined. The resultssuggested that with the increasing of content of hydrophilic groups, neutralizationdegree and hydrophilicity of molecular chains, particle sizes decreased whereas boththe dispersability and stability of emulsion improved. With the increasing of resincontent of the emulsion, both the dispersability and stability of emulsion improvedand at the same time the viscosity increased rapidly. As for the above two kindsprepolymers, the photoinitiator was preferred which had high initiation efficiency.The films curing rate is the fastest when the content of photoinitiator between 3:0%and 4.0%. The films curing rate increased with the increasing of the neutralizationdegree or drying in advance. When triethylamine was served as the neutralization agent not only the curing rate was faster than that of triethanolamine but:also thecured film was not easy to become yellow. As for the PUA films the results showedthat the films' hygroscopicity improved with the increasing of the carboxyl group inthe molecular chains. The tensile strength: of cured films decreased whereas thetensibility at break increased with the increasing of the reaction mole ratio of PPG/DMPA (the mole ratio of TDI/HEMA was invariable) or PPG/HEMA (the mole ratioof TDI/DMPA was invariable).The results of the applied research for the EB and PUA resins showed that both anew kind of water based varnish with excellent properties which was made up resinthat PUA/EB=30%-70%(wt%).