Compounds Based on dDped Bi2O3 as New Ecologically Friendly Yellow-Orange Shade Pigments

Background

Natural inorganic pigments, derived mainly from mineral source, have been known since prehistoric times and human history is rich with examples of their use. The first clear yellow pigments, orpiment (arsenic sulfide) has been found on wall paintings in Giza dated as early as 4000 BC. In ancient Egypt and later in Assyria and China, this yellow colorant was prepared by grinding of the naturally occurring mineral of the same name, i.e. Orpiment. Resent archeological findings documented its use by our ancestors for aesthetic, religious and other purposes. By the way, the preservation of primitive pictures drawn thousands years ago, demonstrate one of the strongest aspects of inorganic pigments – their long lasting stability.

One of the first synthetic yellow pigments we know of is called Naples yellow (lead antimonite). Moreover, it is one of the oldest synthetic pigments, dating from around 1620.  Naples yellow was used extensively by the old masters and well into the 20th century. The genuine pigment is toxic, and its use today is becoming increasingly rare. Typical modern yellow pigments include chromate compounds of lead, cadmium sulphides and bismuth vanadates (Buxbaum, 2005). The important characteristics of these pigments, including composition, refractive index, density and covered color range are summarized in Table 1.