| 摘要 |
PURPOSE: To improve weak pressure color development or to prevent developed color stains by emulsifying and dispersing polyvalent isocyanate and a tertiary aniline compd. in a hydrophilic liquid and adding polyvalent amine to this emulsified dispersion and coating hydrophobic liquid droplets with a polyurethane urea film. CONSTITUTION: Polyvalent isocyanate, a tertiary aniline compd. represented by formula and a hydrophobic liquid containing an electron donating org. color former are emulsified and dispersed in a hydrophilic liquid and polyvalent amine is added to the obtained emulsified dispersion and hydrophobic liquid droplets are coated with a polyurethane urea film to obtain microcapsules. At this time, in order to obtain microcapsules excellent in color forming properties, solvent resistance and heat resistance, it is pref. to together use at least aromatic polyvalent isocyanate and aliphatic polyvalent isocyanate. By this constitution, microcapsules for a pressure-sensitive copy sheet having a polyurethane urea wall film and having both of color forming properties and pressure resistance are produced. |
