Anthraquinone pigments in the paint industry
Blue anthraquinone pigment is the most widely used among the materials of this group. It is used not only in the production of paint products, but also in printing and some other industries. The strength of blue anthraquinone pigment is similar to copper phthalocyanine (an organic dye also known as monastral blue). The blue anthraquinone pigment is made by alkaline melting of ?-anthraquinone with anhydrous sodium acetate and sodium nitrate.
Phthalocyanine dyes in the paint industry
The most prominent representative of this group is phthalocyanine copper or phthalocyanine blue pigment. The powder is insoluble in various kinds of alcohols, oils, most solvents of organic origin, as well as water. Copper phthalocyanine pigment properties and coloring may vary depending on how it is produced. The main advantage of this pigment for paintwork materials is its high lightfastness and resistance to acids and alkalis. In addition, copper phthalocyanine is able to withstand high temperatures (up to 500°C) without losing its original properties. When interacting with chlorine under certain conditions, the color changes, the substance becomes green, sometimes with a yellowish hue.
Azo pigments in the paint industry
Among all organic pigments used in the paint industry, azo pigments are the most widespread. This is due to their wide color range, richness and great brightness. Color of azo pigments varies from greenish-yellow to dark violet. The most common and demanded in the paint industry: yellow, red and orange. Yellow lightfast pigment has very high lightfastness values. It is used not only for production of paints and coatings but also in many other industries. Color of azo pigments depends on its method of production and structural peculiarities.
Azo pigment is scarlet bright red. It is often introduced into paintwork materials used for exterior and interior finishes. It is also used in the production of colored pencils, in printing, etc. Often, scarlet azo pigment can be found together with the filler, which is a mixture of aluminum hydroxide and barium sulfate. Among the main properties are high resistance to atmospheric corrosion, resistance to alkalis and acids.
Pigment varnishes in the paint industry
Pigment varnishes are produced from three kinds of dyes: mordant, acid and basic. Mordant dyes are water soluble. Their composition includes substituents, due to which complexes with metals are formed. The production of pigment varnishes from mordant dyes is due to their ability to complex.
In practice, compounds based on alizarin (oxyanthraquinone dye) are most commonly used - kraplaks. Varnishes of pink, red and brown colors are obtained by complexation of alizarin with Ni, Al, Sn, Mn, Ca, Fe, Co. Varnishes are used for the production of nitro enamels, oil paints, as well as in printing industry and for the manufacture of artistic compositions. They are highly resistant to chemical compounds and light. Example of a kraplak: Alizarin aluminum-calcium varnish, deep red with a blue tint.