| 摘要 |
[Problems] To provide a coating composition for undercoating which, in forming a gas-barrier layer having a crosslinked structure between a polycarboxylic acid type polymer and polyvalent metal ions by the heating at a low temperature for a short period of time, permits polyvalent metal ions to be easily and quickly fed into the polycarboxylic acid type polymer and, besides, into the whole gas-barrier layer. [Means for Solution] A coating composition containing, as chief components, a nonaqueous polyester polyol, an isocyanate compound, and an alkaline compound of a polyvalent metal that serves as an ion source for forming the crosslinked structure, wherein (a) the nonaqueous polyester polyol contains a nonaqueous polyester polyol which contains a metal element in the resin skeleton thereof as an essential component, and (b) the alkaline compound of the polyvalent metal has an average primary particle size in a range of 0.005 to 0.5 u m. |
