Lead replacement in the Molybdate Orange colour space

Abstract

Due to the toxicological concerns over lead and lead compounds, there has been an increased trend to replace lead based materials in paint systems. Change in this instance has been driven primarily by Legislation and regulations, however in many cases global companies wish to show a unified approach and some have taken both a positive environmental marketing approach over their competitors with Lead free paints and a positive move on labour relations. The pigment manufactures have had the challenge to meet these requirements either from existing product ranges or to develop new pigments that are both commercially and technically viable. Due to the diverse application, systems and cost structures within General Industrial Paints no single product offers a universal solution. The higher performing pigments generally meet the higher specifications technically but because of their chemical complexity in processing and structure fail to achieve the lower comparable costs against Molybdate Oranges. With less complex pigment structures limitations are identified within the technical area. Additionally within the range of Molybdate Oranges differing grades are available treated to enhance temperature stability and chemical resistance or untreated to attain lower costs and increased saturation. For this reason paint producers have the choice of a single product within the mid performance area that would act as a compromise or alternatively select three products to fulfil all requirements with the associated logistic problems on supply, stock inventory and quality testing. Within the single product approach Pigment Orange 81 potentially offers the most flexible solution to the paint manufacturer in order to meet the volume market for Mid performance offering opacity, gloss, rheology, bleed resistance, good temperature stability and of great importance the ability to match the colour space occupied by Molybdate Orange. For the multiple pigment approach: High technical performance Pigment Orange 73 offering higher saturation than Molybdate Orange but with associated costs. Mid performance Pigment Orange 81 Cost effective Pigment Orange 34 and Pigment Orange 16 offer high saturation but limitations in durability.