Synthesis Of Hyperbranched Oligomers And Their Application For UV Curable Jet Ink

The UV curable oligomer, which determined the properties of film ( hardness, flexility, adhesion, optical performance and aging resistance), was one of the most important raw materials in UV curing coating materials. The oligomer and monomer were more than 90%wt in the coating formulation.The UV curable hyperbranched oligomers were synthesized in two different ways. Firstly, a hyperbranched oligomer with eight double bonds (P1) was synthesized by Michael addition reaction of ethylene diamine (EDA) and ethyoxyl trimethylolpropane triacrylate (EO-TMPTA) under mild conditions. That was, the mole ratio of EO-TMPTA and EDA was 5.0: 1.0, reaction time was 6-8 h, reaction temperature was 25-30℃, and the dosage of methanol as the catalyst and solvent was about 20%. Secondly, the other UV curable oligomer with six double bonds (P2) was synthesized by acrylic acid, PP50 and hexanedioic acid. The best conditions of synthesis was, the reaction temperature was 80-90℃, reaction time was 10 h, the dosages of catalyst was 1.5% and solvent was 20%. The physical and chemical properties of P1 and P2 using in inks were analyzed by testing the hardness, flexility and adhesion of the coatings capability. And these properties were close to commercial products such as Viajet100, CN3100, CN3105 and CN132. The jet inks A, B and C was prepared by P1, P2 and Viajet 100 separately. The performances of them were analyzed and compared by studying the viscosity, curing time, shrinkage ratio, flexility, hardness and adhesion.Furthermore, the yellow UV curable jet ink was preparation with PL The dispersing stability, physical and chemical performances of yellow UV curable jet ink were studied. Good pigment-dispersing stability is necessary for pigment-based ink-jet inks. In this study, the pigment with grinding medium is grinded into color paste which is then used in UV curable jet inks. The correlation of the grinding time and granularity of the pigments is investigated. The applicable dispersant and the best content used in H4G based UV curable jet inks are also discussed. The improvement of pigment dispersability of H4G-based UV curable ink jet inks with grinded yellow pigment is confirmed by SEM. Moreover, the curing time, hardiness, flexility and several chemical resistant of the coating which was cured by UV curable jet inks are measured.