Synthesis And Applications Of UV-curing Polyurethane Acrylates Emulsion

In response to the 21st century high efficiency,energy saving,green and environmental protection,water-borne UV curable system stands out in numerous curing system,with non- toxic,non-polluting,without excitant and production safety advantages,which is relatively active research and development fields.This paper introduce that an excellent hydrophilic and ionic UV-curing water-borne polyurethane acrylates (WPUA) was synthesized through the three-step synthesis method, with toluene disocyanate(TDI),polyether glycol(PO3114),dimethylol propionic acid(DMPA), hydroxyethyl acrylate(HEA) and triethylamine(TEA),which was made the water-borne poly- urethane acrylate emulsion.The water-borne polyurethane acrylates emulsion(WPUA),water-based polish oil and ink formulations were studied. Photoinitiators'type and dosage,neutralizer's type,neutralization degree,solid content and the ratio of reactants were discussed on the speed of light curing, meanwhile the performance of light curing film was studied,and the content of hydrophilic groups,neutralization degree,solid content and the isocyanate index (R value) were discussed on the properties of emulsion.The results showed that:the molecular chain hydrophilic enhanced,emulsion particle size declined,the dispersion and stability improved with hydrophilic groups content and neu- tralization degree rising;In light-cured properties,Darocur4265 is the best photoinitiator,and optimum dosage is 2%,the light-cured speed is the fastest when neutralization degree is 80%;The light-cured speed with NaOH as neutralizer is faster than triethylamine (TEA), But not emulsified completely.For the best ratio of reactants is that:n(TDI):n(PO3114):n(HEA): n(DMPA)=6:2:4:3.The cured film of synthetic resin has good water, solvent and acid resis- tance,but alkali resistant is bad. In the determination of the polish oil formulation,when the solid content increased,the viscosity increased,the gloss of the cured film first increased,then decreased slightly,the light curing time increases firstly and then decreased,and solid content in the most appropriate is between 70 to 80 percent;The pH value is too high,viscosity reduced,gloss reduced,while pH value too low,alkaline weaken,viscosity higher,gloss reduced,The most appropriate pH value is 8-9.In the determination of ink formulations, the higher the solid content,the faster the cure; The pigment exist shield effect on light initiator;The base material that have smaller heat capacity will speed up the light-curing rate.