PREPARAÇÃO DE ÓXIDOS DE FERRO COLORIDOS APLICADOS COMO PIGMENTOS INORGÂNICOS EM TINTAS IMOBILIÁRIAS

Abstract

The colors are part of our daily life since the beginning of humanity, possessing a symbolic and magical character. Thus, the search for new colors that innovate and are easy to prepare, makes the pigment industry grow increasingly. In order to facilitate the preparation of pigments, make them cheaper and discover new colors, it is up to the researchers to seek out new methods of synthesis. In this work the method used was the precipitation in alkaline medium using iron salts (FeCl3, Fe(NO3)3, FeSO4 and Fe2(SO4)3) and alkaline solutions (NaOH, KOH and NH4OH) to form colored iron oxides, which are widely known as natural inorganic pigments. The twelvw samples produced were left in aqueous suspension and dispersed in white, colorless commercial paint, in order that their pigment behavior was evaluated. Structural characterization (XRD), thermal (TG), spectroscopic (Vis-NIR and Raman) and colorimetry analyzes were performed for powdered pigments. The phases of iron oxides formed depend on the precursors (iron salt and hydroxide) used in the synthesis, producing samples with different particle size and shape and different colors. The phases indexed were: goethite, hematite, magnetite and lepidocricite. Inorganic pigments produced by precipitation in alkaline medium have good dispersion and good coating power when applied being compatible with natural and synthetic commercial pigments.