PROCESS FOR PRODUCTION OF POLYURETHANE EMULSION FOR AQUEOUS ONE-PACKAGE COATING MATERIALS

摘要

[PROBLEMS] To provide a process for the production of a polyurethane emulsion for aqueous one-package coating materials which are excellent in storage stability, safe with concern for the environment, and excellent in applicability and in the appearance, water resistance, and solvent resistance of film. [MEANS FOR SOLVING PROBLEMS] A process for the production of a polyurethane emulsion for aqueous one-package coating materials, characterized by reacting an organic diisocyanate (a1) with a high-molecular polyol (a2) having a number-average molecular weight of 250 to less than 1,000 and a carboxyl-containing low-molecular glycol (a3) to prepare a carboxyl-containing isocyanato-terminated urethane prepolymer (A), mixing the prepolymer (A) with a hydrophobic polyisocyanate (B), neutralizing the carboxyl groups contained in the system with a neutralizing agent (C), and then emulsifying the resulting mixture in water.