| 摘要 |
PURPOSE:The titled composition for printing ink, preventing chemical destruction (extraction of inner phase substance) through an alcoholic dispersing medium by using micro-capsules made of a film consisting of melamine resin, polyurethane resin, etc. CONSTITUTION:Micro-capsules made of a film material consisting of both melamine-formaline resin and a resin derived from a polyfunctional isocyanate compound (e.g., polyurethane, polyurea, etc.), having pigment, adhesive, etc. in its inner phase are dispersed into an alcoholic dispersing medium, to give the desired composition for ink of gravure printing, flexographic printing, etc. To obtain the capsules, for example, the polyfunctional isocyanate compound is dissolved in a hydrophobic liquid to give a solution, which is emulsified in an aqueous solution into droplets. A melamine-formaline precondensate is added to the emulsion so that a film of melamine resin is formed on the droplets, and an active hydrogen-containing compound, e.g., a polyfunctional amine, etc. is added and reacted with an NCO group, to form a polyurethane resin film, etc. |
