METHOD FOR COATING SUBSTRATE OF POOR COHESIVENESS AND POOR ADHESIVENESS WITH WATER-BASED COATING MATERIAL COMPRISING POLYURETHANE RESIN, AND SUBSTRATE OF POOR COHESIVENESS AND POOR ADHESIVENESS COATED BY THIS METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for coating a substrate of poor cohesiveness and poor adhesiveness with a water-based coating material comprising a polyurethane resin, and a substrate of poor cohesiveness and poor adhesiveness coated by this method.;SOLUTION: The coating method comprises the step of introducing a gasified modifier comprising a silicon atom or the like having a boiling temperature of 10C to 105C as it remains gaseous and combustion air into fuel gas in such a manner that the air/hydrocarbon mole ratio in the combustion gas is kept not lower than 23, burning thus prepared combustion gas to form a flame of the fuel gas, treating the surface of the substrate of poor cohesiveness and poor adhesiveness by applying the flame onto it to activate the surface so that its wetting index becomes 73 dyn/cm or higher, and subsequently coating the treated substrate with a water-based coating material comprising a urethane resin, whereby the substrate of poor cohesiveness and poor adhesiveness can be directly coated with the water-based coating material comprising a urethane resin with high cohesion and adhesion strength without requiring a commonly practiced pretreatment with a primer as cohesive and adhesive aids.;COPYRIGHT: (C)2008,JPO&INPIT