| 摘要 |
The invention provides a novel bottom coating agent tightly fitting with the metal film layer, especially the generation of whitening parts and obvious cracks is avoided on the metal surface in a high-temperature environment. The bottom coating agent comprises a copolymer (A) and a polyisocyanate compound (B) comprising at least three isocyanate groups. The copolymer (A) is obtained from the reaction of the hydrophobic monomer (a1) represented in the general formula (1) with the monomer (a2) containing a hydroxyl group represented in the general formula (2) and the concentration of the hydroxyl group is 0.001 to 0.005 mol/g. In CH2 = C(R1)-[-(C = O)-O-] m-X (1), R1 represents a hydrogen or a methyl, m represents 0 or 1, X represents an alkyl group without a hydroxyl group, a phenyl group without a hydroxyl group or a benzyl group without a hydroxyl group. In CH2 = C(R2)-[-(C = O)-Y1-] n-Y2 (2), R2 represents a hydrogen or a methyl, Y 1 represents an oxygen or a secondary amino group (-NH-), n represents 0 or 1, Y2 represents an alkyl group with a hydroxyl group, a phenyl group with a hydroxyl group or a benzyl group with a hydroxyl group. |
