Preparation Of Aqueous Intaglio Printing Ink For Plastic

Water-based polyurethane grinding resin and polyurethane emulsion with solid content of 46-48% and 35% respectively was synthesized by use of acetone method. The effect of different kinds of soft and hard segments on properties of polyurethane emulsion and its dried film were discussed, meanwhile the effect of solid content and mole ratio of -NCO to -OH on water-based polyurethane grinding resin and the dispersion of pigment in this kind of grinding resin was also investigated. The results showed that either the stability and viscosity of polyurethane emulsion or the mechanical properties and water absorption rate of dried film exhibited reasonable changes with mole ratio of soft segments or hard segments of polyurethane. The viscosity of grinding resin which played negative role in the grinding process increased with solid content or mole ratio of -NCO to -OH in our study range. When the grinding time extended, the size of pigment particles decreased and then leveled off. The smaller the particle size was and the more alkalized the aqueous polyurethane-based ink was, the better the dispersion of pigment was. The printing ink showed excellent adhesion to PET substrate.Another kind of aqueous intaglio printing ink was prepared by mixing polyurethane-acrylate (PUA) hybrid emulsions which were synthesized by emulsion copolymerization and confirmed by IR with polyacrylate-phthalocyanine blue pigment dispersion. The effect of acid content (wt%), NCO/OH(mol/mol), neutralization degree, different kind of diisocyanate, the amount of β-hydroxyethyl acrylate (HEA) and methylacrylate(MMA) on the properties of PUA and its ink was studied. The effect of different vinyl monomers MMA and butylacrylate (BA) on properties of emulsion and ink was also investigated. The results showed that with increasing acid content and neutralization degree, the stability of the hybrid emulsion increased but water and acetone resistant properties of film deteriorated; under the condition of high acid content, the effect of NCO/OH on the mechanical stability of emulsion was not severe, however, the freeze-thaw stability of emulsion and the...