TONING OF POWDER COATING MATERIAL

摘要

PROBLEM TO BE SOLVED: To tone a powder coating material so that a coating film having a nearly uniform color tone without any defect such as segregation of colors in spite of being dry blended powder coating materials of plural colors by uniformizing the quantities of electrification of the powder coating materials within a certain range. SOLUTION: This method is to tone powder coating materials of plural colors by compounding the powder coating materials in a prescribed ratio and dry blending the powder coating materials with a mixer. The quantities of electrification of the powder coating materials of respective colors are previously regulated so that the differenceΔQ (=Qmax -Qmin ) between the maximum value Qmax and the minimum value Qmin of the quantities of the electrification of the powder coating materials of the respective colors before toning satisfiesΔQ<|Qmax|m0.20. A particulate silica-based surface treating agent is preferably added to the powder coating materials of the respective colors before the toning to regulate the quantities of electrification.