Study On The Development And Synthesis Process Of UV Curable Coatings Based On Alicylic Epoxy Resin

Ultraviolet(UV) curable coatings are a kind of new green coatings cured under UV irradiation, mainly including light active oligomers, active diluents, light initiator and all kinds of additives, etc. Compared with the traditional coatings, UV curable coatings have many advantages:high efficiency, wide adaptability, economy, energy saving and environment friendly, and have gradually replaced the traditional curable coatings. Alicyclic epoxy polyurethane acrylate is a combination of alicyclic epoxy resin and polyurethane acrylate, and can be used as a high-performance UV curable coatings substrate.Under the appropriate process conditions, by selecting the isophorone diisocyanate (IPDI), hydroxypropyl acrylate (HPA), polyethylene glycol200 (PEG200), maleic anhydride (MA), alicyclic epoxy resin (TTA21) and so on as reactive monomers, alicyclic epoxy polyurethane acrylates, modified by maleic anhydride polyethylene glycol monoester, were synthesized using noumenon method. Alicyclic epoxy polyurethane acrylates, modified by oleic acid, were synthesized the same way by selecting IPDI, HPA, alicyclic epoxy resin (TTA21,TTA22), OA and so on as reactive monomers.The structure of the products were characterized and analyzed by FTIR and 1HNMR spectras, which further proved that the synthesized products were indeed the target products. Various synthetic resins were prepared for film-forming and cured according to basic formulation. Viewing from a series of the film properties of synthetic resins, the curing film of TTA21-OA-60%UA (60% indicates that the amount of urethane acrylate takes up 60% of the open hydroxyl content) oligomer was the best, and the performances of tested film are as follows:film thickness 14.50μm, UV curing time 35min, hardness 2H, impact resisitance 100cm, adhesion level 0, excellent resistance to boiling.The process conditions in the synthesis of the oligomers were studied by mainly discussing the influence of the reaction temperature, the amount of catalyst and other factors on the synthesis of TTA21-OA-60% UA oligomers. The optimum conditions of the synthesis process are determined as follows:the reaction temperature is 120℃; the amount of the catalyst triethylamine is 0.4% of the total amount of the reactive monomers in the synthesis of TTA21-OA; the reaction temperature is 50℃, the amount of the catalyst DBTDL is 0.3% of the total amount of the reactive monomers in the synthesis of TTA21-OA-60%UA.And the influence of adding amount and type of reactive diluent, photo initiator on the film properties were also studied, then components of coatings and their dosage range were determined. The resin is TTA21-OA-60%UA, and the content is 45wt%-55wt%; main reactive diluent is TPGDA, and the content is 40wt%-50wt%; the photoinitiator is Irgacure 184, the content is 4wt% to 6wt%.