PAINT ,VARNISH & LACQUER
Once a formulator has decided on the shade required for a particular application, the next most important criteria of anypigment are its fastness properties according to the final color products.
Titanium dioxide, in the two naturally occurring crystal forms, anatase and rutile, is the most important white pigment, whichprovides maximum opacifying power. Normally, TiO2 pigments are not used in their pure form because of their poor dispersibility in a variety of resins and solvents. Generally, they are surface coated with small amounts of alumina, silica, or both (up to 3% total, on TiO2) to increase the functionality of the surface (active adsorption sites for the resin molecules) and to improve dispersibility and impart stability to the dispersion, especially in alkyd resin paint systems.
The most common and economical inorganic blue is iron blue, Pigment Blue 27, a complex ferriferrocyanide having the formula FeNH4 Fe(CN)6.xH2O. Originally called Prussian Blue Chinese Blue is a fine grade that exhibits a green undertone as compared to the original Prussian Blue. Bronze blue is a variety that exhibits a surface bronze that depends on the angle at which the surface is viewed
Chrome orange, Pigment Orange 21, is a basic lead chromate formed under alkaline conditions to give a product of empirical formula PbCrO4 . x PbO. Shades from a yellow-shade to a red-shade orange can be produced, depending on the alkalinity of the reaction ma
Iron oxide red
iron oxide browns, we again see pigments that are available as both natural and synthetic products. Iron oxide red, Pigment Red 101
Violet 15, a sodium sulfosilicate prepared by oxidation of Pigment Blue 29,Ultramarine blue. The redness of hue of the violet is determined by controlling the degree of oxidation.Chemically the pigment is Na4H2Al6Si6O24S2.
Yellow 32 and is chemically strontium chromate, SrCrO4, prepared by precipitating a soluble chromate with a solution of an appropriate strontium salt. The pigment is used primarily in corrosion-inhibiting coatings. Its poor tint strength, low
Pigments are usually dispersed in vehicles or substrates for application, as for instance in inks, paints,plastics, or other polymeric materials. Pigments retain a crystal or particulate structure throughout the coloration process.
Copper Phthalocyanine Blue
Copper phthalocyanine blue (PB 15), with its usage far outweighing other blues such as Indathrone blue (PB 60).
Types of Quinacridone
Color Index Name Hue Comments
PO 48 Gold Quinacridone quinone
PO 49 Deep Gold Quinacridone quinone
PR 122 Magenta-yellow 2,9-Dimethyl quinacridone
PR 192 Red-yellow Unsymmetrical monomethyl quinacridone
PR 202 Magenta-blue 2,9-Dichloroquinacridone
PR 206 Maroon Mixed solid solution
PR 207 Scarlet 4,11-Dichloroquinacridone
PR 209 Yellow-shade red 3,10-Dichloroquinacridone
PV 19 Violet-blue- Quinacridone
Yellow pigments can be subdivided into four broad classifications based on their chemical constitution. These classifications are comprised of monoarylide yellows, diarylide yellows, benzimidazolone yellows,and heterocyclic yellows.