The effect of the chemical composition and the volume of coated carbonate calcium on epoxy paint properties

Resumo

Titanium dioxide (TiO₂) is widely used in the paint industry as a white pigment. To reduce the high cost of TiO₂, mineral fillers such as different calcites are usually added to the paint. However, this addition affects the quality and properties of paints. In the present article, the precipitated calcium carbonate (PCC) and the ground calcium carbonate (GCC) that coated with the stearic acid, were added into the epoxy paint at two different volume concentrations as fillers. The optical observation and paint properties such as the reflectness, the hardness, the scratch and the bending resistance and wear properties were investigated. Results showed that paint properties depended on the PCC or GCC content in the paint. GCC filler (10 wt %) raised the reflectance of the pure epoxy paint to 85%, relatively. The best filler for increasing the hardness and the scratch test was 20 wt % PCC. The specimen with 10 wt % PCC showed the best wear resistance. The presence of the coated calcium carbonate could change the wear mechanism from cutting to gouging.