| 摘要 |
PURPOSE: To obtain a powder coating suitable for the use of a triboelectric spray gun and capable of forming a thin coating film by incorporating a specific quaternary ammonium salt copolymer into a binder resin and forming a powder having a specific small particle size from the resulting mixture. CONSTITUTION: This powder coating has an average particle size of 5 to 20μm, and comprises at least a binder resin and a quaternary ammonium salt copolymer comprising recurring units of formula I (wherein R1 is H or CH3 ) and formula II (wherein R2 is H or CH3 l R3 is alkylene; and R4 , R5 and R6 are each alkyl). Since it has the above-specified average particle size, a thin coating film can be formed. In the case of using a triboelectric spray gun, addition of the copolymer enables the powder coating to be electrified to a positive polarity with a suitable amt. of electrification through friction thereof with a fluorinated member installed in the coating conveyor portion of the gun even in a high-temp. and high-humidity environment, whereby the amt. of the powder coating adhered to an article to be coated is not decreased even when the gun is continuously used.
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