| 摘要 |
PROBLEM TO BE SOLVED: To provide an aqueous covering composition for an inner veil of food packages contacting to food for a long time and releasing no blocking agent during crosslinking. SOLUTION: The aqueous covering composition comprises a mixture of (A) a polyisocyanate having, on the average, two or more NCO groups per one molecule, wherein≥85% NCO group is blocked with a blocking agent containingε-caprolactam, p-hydroxycarboxylic acid or an aliphatic alcohol, and (B) a hydrophilic polyester polyol or a hydrophilic and nonhydrophilic polyester polyol, having, on the average, two or more reactive hydroxy per a molecule [the component (B) has acid value of≥15 mgKOH/g, hydroxy value of 20-300 mgKOH/g and weight average molecular weight Mw of >1,500 g/mol], wherein equivalent ratio of blocked isocyanate group of the component (A) to isocyanate reactive group of the component (B) is 0.5-5.0:1. COPYRIGHT: (C)2006,JPO&NCIPI |
