Fold azo pigment
Water-insoluble organic compounds containing azo group (-n =N-) in molecular structure are the most diverse and productive organic pigments. Azo pigments are diazo components produced by aromatic amine or heteraramine by diazotization and then coupled with acetyaramine, 2-naphthol, pyrazolone, 2-hydroxy-3-naphthol formic acid or 2-hydroxy-3-naphthol formamide and other coupling components, to produce water insoluble precipitation, namely the general azo pigments. The synthesis method is basically the same as azo dyes, but the latter is water-soluble. General azo pigments are orange, yellow and red pigments such as permanent Orange RN(C.I. pigment orange 5), golden red (C.I. pigment red 21), benzidine yellow G(C.I. pigment yellow 12). In order to improve the properties of pigments such as sun-resistant, heat-resistant and organic solvent resistant, two molecules can be condensed into macromolecules by aromatic diamine. Pigments produced in this way are called macromolecules or condensed azo pigments such as macromolecules orange 4R(C.I. pigment orange 31) and macromolecules red R(C.I. pigment red 166).
Fold the lake
A water-insoluble pigment produced by interaction with a precipitant. Its color is more brilliant, chromatogram is more complete, production cost is low, than the original water-soluble dye fastness to the sun. The precipitants are mainly inorganic salts, acids and carriers. Insoluble salts such as permanent red F5R(C.I. pigment red 48:2) and golden red C(C.I. pigment red 53:1) are produced by the reaction of barium chloride, calcium chloride, manganese sulfate and other salts with water-soluble dyes. Acid precipitation is the reaction of phosphate-molybdic acid, phospho-tungstic acid and tannic acid with water-soluble basic dyes to produce insoluble lakes, such as: sunfast rose lake (C.I. pigment violet 1), luminous cyan (C.I. pigment violet 3). Carrier precipitation is the deposition of water-soluble dyes on the surface of carriers such as aluminum hydroxide and barium sulfate to form water-insoluble lakes such as acidic golden lake (C.I. pigment orange 17) and fast lake Blue lake (C.I. pigment blue 17).