| 摘要 |
<p>A resin composition for cationic electrodepositing paints which has a high throwing power and does not foul a top coated film and is particularly suitable for two-coat finishing, said resin composition comprising the reaction product of [A] a basic polyamino resin containing amino groups and/or hydroxyl groups capable of reacting with isocyanate groups, with [B] a polyisocyanate mixture composed of (i) 40 to 95 mole % of a low-volatile partially blocked aromatic polyisocyanate containing at least two benzene rings having an isocyanate group directly bonded to a nuclear carbon atom, in which substantially all isocyanate groups except one are blocked with an alcohol, (ii) 2.5 to 60 mole % of a low-volatile fully blocked aromatic polyisocyanate containing at least two benzene rings having an isocyanate group directly bonded to a nuclear carbon atom, and (iii) 2.5 to 40 mole % of a difunctional polyisocyanate, the mole percentages being based on the total amount of the polyisocyanates (i), (ii) and (iii); and an aqueous bath for cationic electrodeposition comprising aforesaid resin composition, a water-soluble aqueous inorganic or organic acid as a neutralization agent for said resin composition, and an aqueous medium.</p> |
