AQUEOUS DISPERSION OF POLYURETHANE FOR HEAT-RESISTANT HEAT-SENSITIVE SHEET OVERCOAT, ITS MANUFACTURING PROCESS, COMPOSITION CONTAINING THE AQUEOUS DISPERSION AND HEAT-RESISTANT HEAT-SENSITIVE SHEET COATED WITH THE COMPOSITION

摘要

PROBLEM TO BE SOLVED: To provide an aqueous dispersion of a polyurethane for heat-resistant heat-sensitive sheet overcoats having good heat resistance and printability. SOLUTION: An intermediate prepolymer (C) is obtained which is composed of a polyol (A), a hydrophilic group-containing active hydrogen compound (H) having at least one kind of anionic hydrophilic group and at least one kind of active hydrogen-containing group and an organic polyisocyanate (B). A urethane prepolymer (E) is obtained by reacting all or part of the isocyanate groups at the molecular terminal or hydroxy groups at the molecular terminal of the intermediate prepolymer (C) with an alkoxysilane derivative (D). A hydrophilic group-containing water-based polyurethane resin (F) which is emulsified or dispersed in water is obtained by neutralizing the anionic hydrophilic groups of the urethane prepolymer (E) with ammonia. COPYRIGHT: (C)2007,JPO&INPIT