Chrome iron black pigments

Chrome iron black pigments have been used for years in vinyl siding to minimize heating and distortion under solar exposure. They are also superior IR... 

Chrome Iron Nickel Black, pigment for plastics, 7 369t... 

Chrome iron nickel black Pigment black 30 (Ni,Fe)(Cr,Fe)204... 

When we compare the masstone reflectance curves of iron chrome brown and iron chrome black pigments, we see the result of this effect where the black pigment has an expanded absorption region that covers the optical region. As discussed, the primary cause is the larger particle size. Iron chrome pigments with crystal sizes less than 0.5 are typically brown, and greater than 1.5 appear black. 

Iron chrome spinels of composition CnFeo.sCri 5O4 give black pigments. Spinels are actually magnesium aluminates generally... 

For products for outdoor use, such as bottles and shipping crates made from HDPE, the following pigments are recommended white opac (rutile Ti02 after-treated), yellow (cadmium yellow, nickel titanium yellow, chrome titanium yellow), red (cadmium red, iron oxide red), blue (cobalt blue, ultramarine blue), green (cobalt green, chrome oxide green), brown (iron oxide brown, chrome iron brown), black (carbon black-furnace). 

An increasing number of colored inorganic pigments are FDA-compliant. Historically, yellow iron oxide, red iron oxide, black iron oxide, zinc ferrite, burnt umber, raw and burnt sienna, channel carbon black, chromium oxide green, ultramarine blue, cobalt blue and copper chrome black have enjoyed FDA—compliant status, under 21 CFR 178.3297, Colorants for Polymers . More recently, the FDA has been successfully petitioned with regard to nickel titanium yellow, chrome titanium yellow, and cobalt green under 21 CFR 170.39, Threshold of Regulation for Substances Used in Food-Contact Articles . 

The choice of pigments is limited for fluoroelastomers as most would not withstand high temperatures. The most typical are red iron oxide and chrome oxide, which are often used at 1-2 phr level with 2 phr of Ti02 to get consistent white background, and 1 phr of MT black to give less vivid colors. More pigments are now available, which exhibit adequate heat resistance, such as blue compounds (Stan-Tone D-4005 and D-4006, or Cromophtal Blue 4GNP). 

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