Prime pigments

Hiding (or prime) pigments scatter light and arc used to obtain opacity ... 

Prime pigments are used for their ability to hide or cover the surface. The term hiding power is used to describe the relative abihty of fixed amounts of different pigments to cover a surface and depends on the difference in refractive indices between the pigment and the binder thus primary pigments usually have high values in refractive index. 

Extender pigments give relatively httle hiding, but their cost is lower than that of prime pigments they provide control of such properties as flow consistency, durability, and adhesion. 

CAS 14807-96-6 EINECS/ELINCS 238-877-9 Uses Extender of prime pigments in high-performance coatings Features Ultra fine, low consistency no ozone-depleting substances Properties 100% < 20 p, 100% < 10 p, 32% < 1 p particle size 1.7 p median particle size sp.gr. 2.85 dens. 23.7 Ib/gal oil absorp. 39 GE brightness 92 pH 9.4... 

Pigment Any fine solid particles that do not dissolve in the varnish. If they do not provide colour they are called extender particles. Extenders are much cheaper than prime pigments and can carry out many useful functions, e.g. improvement of adhesion, ease of sanding and film strength. 

Paint typically contains four major components. They are pigment, binder, liquid, and additives. The pigment is simply a powder in its unmixed form. It is used to determine the paint s color and appearance. Prime pigments are responsible for the paint s color or whiteness. Titanium dioxide is the main ingredient (prime pigment) in most white paints. Extender pigments are used to add bulk to the paint. Silica is an example of an extender pigment that is used to increase the paint s durability. 

Prime pigments n. Pigments which possess colorant value and hiding power. The refractive index of these pigments is 2.0 or higher in contrast to extended pigments. 

Titanium dioxide, rutile n. Ti02- Pigment white 6 (77891). A high-opacity, bright white pigment, non-chalking type, used as a prime pigment in paints, rubber, plastics. Prepared from the mineral, ihnenite, or rutile ore. Density, 3.9-4.2g/cm (33-35 lb/ gal) O.A., 16 8 particle size, 0.2-0.3 pm, refractive index, 2.76. Syn titania. 

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