Novel environment friendly inorganic red pigments based on Bi4V2O11
Novel environment friendly inorganic red pigments, (Bi1−x−yZrxAly)4V2O11+δ (0 ≤ x ≤ 0.15; 0 ≤ y ≤ 0.10), were successfully synthesized by a conventional solid state reaction method, and their colour properties were characterized. The colour of the obtained pigments was dependent on the calcination condition and the sample composition, and the highest red hue was obtained for the (Bi0.92Zr0.07Al0.01)4V2O11.34 pigment calcined at 800 °C for 10 h in a flow of pure O2. The a* value corresponding to the red chromaticity of this pigment was +41.9, which was significantly greater than that of the commercial iron oxide pigment (a* = +28.9). Bi4V2O11 is considered to be a nontoxic compound, and the other components (Zr and Al) are also safe elements. Therefore, the present pigment could be an attractive candidate as a novel environment friendly inorganic red pigment.