Abstract:
PROBLEM TO BE SOLVED: To solve the problem of film surface appearance failures in 1-baking type formation of a chipping-resistant multi-coating film, such as yellowing of the film, lack of smoothness of the film surface and uneven alignment of a luster material, while securing advantages by the 1-baking type formation of the chipping-resistant multi-coating film, such as energy saving and reduction in manufacturing time of a vehicle.SOLUTION: The 1-baking type method for forming a chipping-resistant multi-coating film for automobile body comprises: forming a multi-coating film having a chipping-resistant coating on an automobile body plate by baking and hardening a wet-on-wet coating layer formed on an electrodeposition coating formed on an automobile body by one heating, the wet-on-wet coating layer being formed by successively applying a plurality of coating materials such as a two-liquid hardening chipping-resistant coating material and coating materials for middle coating/top coating by a wet-on-wet method without baking. The two-liquid hardening chipping-resistant coating material is composed of a solution A containing a polyol compound having hydroxyl group and a solution B containing a non-block type isocyanate compound, the viscosity of the two-liquid hardening chipping-resistant coating material in application of the coating material just above the applied chipping-resistant coating material is 9 Pa s or more, and the solvent content at the start of hardening in heating and baking of the two-liquid hardening chipping-resistant coating material is 0.002 g/cmor less.
Abstract:
PROBLEM TO BE SOLVED: To provide a two-pack type acrylic plastisol coating that completes curing by short-time heating at low temperature and does not start curing at ordinary temperature.SOLUTION: The two-pack type plastisol coating is a plastisol coating obtained by dispersion of fine particles of a thermoplastic polymer and comprises fine particles of an acrylic polymer and a dispersion medium in which the fine particles do not dissolve at ordinary temperature, and an organic solvent in which the fine particles have high solubility at 60°C or more. The coating film having the required strength is obtained by 20-minute heating at 80°C. A base resin and a curing agent of adhesion components, a foaming agent and a foaming aid, and additives, etc. are added as needed.