PREPARATION OF GREEN COLORANT FROM MIXED RARE EARTH AND MOLYBDENUM COMPOUNDS AND PROCESS OF SURFACE COATINGS THEREOF

摘要

The present invention proposes the development of inorganic green pigment, having a general formula, RE2MoO6 (where RE is mixed rare earth metal and Mo is molybdenum metal) comprising mixed rare earth elements having atomic number in the range of 57 to 66 and having a composition of at least lanthanum in the range of 43-45% w/w, neodymium in the range of 33-35% w/w, praseodymium in the range of 9-10% w/w, samarium in the range of 4-5% w/w and other rare earths to a maximum of 5% w/w and molybdenum. The colorant can be prepared in a convenient and inexpensive method utilizing the solid state route by calcining the mixed rare earth carbonate and ammonium molybdate at a temperature range of 900-1100° C for 3-6 h at a heating rate of 10°C/min followed by grinding. The well ground calcined powders were used for characterization of the pigments. The phase purity and optical properties of the prepared pigments were investigated. The pigment is useful as a colorant to various substrate materials such' as plastics, paints, ceramics and the like.