Effect of coating composition on UV curable powder coatings

Powder coating properties aredetermined to a great extend by the formulation and the cure conditions. This influence is even larger in the case of UV curable powder coatings, since the UV absorbance of additives and pigments directly affects the process of network formation. The effect of coating composition and layer thickness of the coating was studied by ATR-FTIR, UV light transmission, coating glass transition temperature, coating properties and differential photo calorimetry. Clear relations were found between an increasing pigment level or coating layer thickness and decreasing through cure. A maximum value for the coating thickness at which there is still complete through cure was found.