Plastics cerium pigments

Cerium sulfide pigments are produced from hydrated cerium oxide or oxalate and calcined in an oxygen-free, sulfide environment. They are silica-encapsulated to minimize water-reactivity and to improve heat stability and chemical resistance properties. Because of their low relative value-in-use, they are used primarily in engineering plastics and in particular the polyamides where high-performance organic colorant alternatives and other inorganic pigment alternatives are few. 

Until a few years ago, the red pigment for coloring containers, toys, household wares, plastic crates, etc. was Cadmium Red. This is Cadmium sulfoselenide red, C9Hi3CdN204SSe (CAS 58339-34-7), also known as Pigment Red 108 (see Chemnet 2015). The cadmium compound is now considered environmentally undesirable, so it is being replaced by the non-toxic Cerium(III) sulphide (Cc2S3 CAS 12014-93-6). This compound gives a rich red color and is stable up to 350 °C (Emsley 2001). 

Uses High-temp, thermoelectric material pigment for plastics, food-contact materials Trade Name Synonyms Cerium Orange PO 75 [Rhodia HPCII France... 

Table 4-3 Ti nting strength of cerium sulfide pigments in plastics.

Cerium sulfide pigments can be readily dispersed in a variety of polymeric resin systems using conventional plastics processing equipment. They are both non-dusting as well as dispersible (Figure 4—10). 

Besides the fact that they are compatible with most thermoplastics, cerium sulfide pigments can also be used in a wide range of other polymers including engineering plastics, thanks to their very good heat stability. 

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