With the development of industries, consumers require the highest demands for heat stability, chemical resistance, weather and light fastness to meet their needs. Generally, inorganic pigments especially metal oxide pigments exhibit much more better heat resistance, weather resistance and lightfastness than organic pigments. When produced by high temperature calcination of two or more metal oxides such as Al, Co, Fe, Zn etc., which are blended together and then strongly heated, during the calcining temperature, these oxides are reactive to form a new and more stable molecular structure, this is complex inorganic color pigments shorted as CICPs, it is also called calcined pigment or mixed metal oxides which is short of MMO. These lead to the outstanding properties, for example, excellent fastness to light and weathering, perfect alkali and acid resistance, high heat resistant stability, ease of dispersion, non-bleeding, non-migrating.
Although showing similar colors with different chemistries, some pigments exhibit unique advantages. CICPs are crystallized colors of rutile or spinel whose molecular structurers are very stable. CICPs are the improved performance in heat and chemical stability, UV opacity, hiding power, and infrared (IR) reflectivity. In some applications, heat resistance is an issue such as automotive interiors and exteriors paints, paints for building facades, architectural and facade coatings, vinyl siding and fascia systems, roof coatings and tiles, muffler and stove coatings, fireplace paint, high-heat powder coatings, porcelain enamel and decorative ceramic coatings, fluorocarbon coatings, CICPs can be used well in these areas. CICPs are compatible with most solvent and waterborne systems, these products offer both superior performance and versatility. Hence, CICPs are also suitable for architectural coatings, exterior wall coatings, water-based paints, decorative coatings, coil coatings, industrial coatings, powder coatings, non-stick coatings of non-stick pot and non-stick pan, pot coating of electric cooker etc.
Calcined at temperatures more than 800°C the color component is fixed within the rutile or spinel crystal structure, which results in outstanding chemical resistance, ease of dispersion, non-bleeding, non-migrating, no warping, no shrinkage, outdoor durability and thermal stability. These properties can improve the performance of the product on good UV stability, high heat stability, fastness to light and weathering, and infrared (IR) reflectivity. They will not fade after exposing to ozone, acid rain, strong acids, oxidizing or reducing agents or other air pollutants common in industrialized areas. They are non-migratory and will not dissolve or bleed in contact with solvents. Because of these benefits, CICPs are widely used in engineering plastics, plastics and masterbatches such as plastic bottle, plastic case, kids’ plastic toys, wood plastic composite (WPC), food contact plastics, engineering polymers etc.
As far as known, complex inorganic color pigments are the most heat stable pigments. Furthermore, most CICPs are environment-friendly and non-toxic, only some CICPs contain elements such as Cr, Sb, and Ni that may cause health problems in individuals. After applied in glaze stains, porcelain glass, ceramics glaze and vitreous enamels production with processing temperature 1300°C, CICPs can still keep their colors, for example glass bottle, colored glass, chandelier glass, glass cube, stained glass, blow-molded glass, glassware, decorative porcelain, ceramic tableware, ceramic tile, ceramic color glaze, ceramic glaze, building ceramics, general ceramics, enamel plate, enamelwares, enamel ornaments, porcelain enamel, tea set, general enamels, porcelain enamels, giftware. Besides CICPs, iron oxide red, titanium dioxide, chrome oxide green and ultramarine blue are also used in ceramic glazes, porcelain and enamel. Due to the high performance, CICPs can be also used in silicone, latex, glass paint and ceramic paint, glass ink and ceramic ink, paper, rubber, laminates and co-extrusions, window profiles, wood grain laminate, decking and so on.
CICPs are environment-friendly and non-toxic, based on this, one or two of them or mixed with other pigments are used as alternative to cadmium and lead chromium. The important using is to replace of medium chrome yellow which is applied to water-based road marking paint and traffic marking coating because of the limited use of medium chrome yellow which consists of toxic lead (Pb).
