PURPOSE: To carry out the coating of a cast-metal article in an improved working environment and to dispense with the deburring work after the cutting work of the cast-metal article by coating a cast-metal article for cutting with a powder coating composition composed of fine hollow particles and a resin component having a specific softening point and containing epoxy resin, etc., and curing the coating film with heat.
CONSTITUTION: The surface of a cast-metal article for cutting is coated by applying a powder coating composition composed mainly of (A) a resin component having a softening point of 60-135°C and consisting of an epoxy resin (e.g. bisphenol A epoxy resin) or a mixture of an epoxy resin and a polyester resin (e.g. carboxyl-containing polyester resin) and (B) fine hollow particles (e.g. silica balloon) to the cast-metal article for cutting by electrostatic coating method and curing the coating layer by baking at 150°C (the temperature of the metal article) for 20min. The content of the fine hollow particle of the component B is 10-40vol.% based on the volume of the cured coating film. The coating process can dispense with the deburring work of the coated article after cutting work and enables the coating work in an improved working environment.
TATSUNO TADAYOSHI
OGOSHI TOSHIO
SAGANE MASAHIKO
