| 摘要 |
PURPOSE:To obtain an expandable powder coating material which can give a coating film excellent in adhesion to a metallic or resin surface and excellent in heat insulation properties, cushioning properties and heat resistance by using a hydroxylated thermoplastic resin, a normally solid polyisocyanate compound and a chemical blowing agent as essential components. CONSTITUTION:This expandable powder coating material is prepared by mixing a hydroxylated thermoplastic resin (e.g., partial saponificate of an ethylene/vinyl acetate copolymer) or a mixed thermoplastic resin thereof containing at most 50wt.%, desirably, at most 40wt.% other resins with a crosslinking agent comprising a normally solid polyisocyanate (e.g., diphenylmethane diisocyanate blocked with epsilon-caprolactam) or comprising this polyisocyanate and an organic peroxide and a chemical blowing agent (e.g., azodicarbonamide). The amount of the cross-linking agent is such that the equivalent ratio (NCO/OH) is 1 or below, desirably, 0.03-0.8, and the amount of the organic peroxide is 0.5-7.0 pts.wt., desirably, 1.0-4.0 pts.wt. per 100 pts.wt. resin. |
