| abstract |
The purpose of the present invention is to provide a primer coating composition whereby it is possible to form a primer coating film having excellent adhesion to both a steel sheet and a resin member, as well as excellent humidity resistance. The purpose of the present invention is furthermore to provide a method for forming a coating film using a primer coating composition having such characteristics as described above. The present invention is a primer coating composition including a water-based polyolefin resin (A), a water-based epoxy resin (B), a hydrophilicity-modified carbodiimide compound (C), and a water-based polyurethane compound (D), wherein the water-based polyolefin resin (A) includes a water-based polypropylene resin having a weight-average molecular weight of 50,000-200,000, and the hydrophilicity-modified carbodiimide compound (C) is a hydrophilicity-modified carbodiimide compound (C) having a predetermined structure. |