Opaque white pigment plastic pigments

The TiOj pigment gives the best opaque whiteness of aU pigments. This use is so widespread that it consumes more than 90% of all the titanium oxide produced. The pigment is used for paints, plastics and fine paper but also to make porcelain glazes opaquely white. Titanium oxide is also part of rutile electrodes for welding. 

Zinc oxide (ZnO) is widely used as an active filler in rubber and as a weatherability improver in polyolefins and polyesters. Titanium dioxide (TiOj) is widely used as a white pigment and as a weatherability improver in many polymers. Ground barites (BaS04) yield x-ray-opaque plastics with controlled densities. The addition of finely divided calcined alumina or silicon carbide produces abrasive composites. Zirconia, zirconium silicate, and iron oxide, which have specific gravities greater than 4.5, are used to produce plastics with controlled high densities. 

Polyethylene is translucent to opaque white in thick sections, opacity increasing with density. Relatively clear film can be extruded from polyethylene, especially if it is quenched rapidly. The plastic accepts pigmentation readily. Most coloring is performed using dry-blend techniques. Color dispersion devices are required to ensure thorough mixing of resin and pigment. 

Due to the risk of breakage, glass containers are more and more being replaced by plastic containers. It has been shown that white pigmented, opaque, low-density polyethylene, containers can provide complete photo protection to certain photosensitive products, such as dexamethasone- and predni-solone phosphate-eye drops (6). 

The most familiar compound of titanium is no doubt responsible for the white color of this paper. Titanium dioxide, or more correctly, titanium(IV) oxide (Ti02), is a highly opaque substance used as the white pigment in paper, paint, linoleum, plastics, synthetic fibers, whitewall tires, and cosmetics (sunscreens, for example). Over one million tons is used annually in these and other products. Titanium(IV) oxide is widely dispersed in nature, but the main ores are rutile (impure Ti02) and ilmenite (FeTi03). Rutile is processed by treatment with chlorine to form volatile TiCU, which is separated from the impurities and burned to form Ti02 ... 

Titanium dioxide (E171, Cl white 6) is a white, opaque mineral occurring naturally in three main forms rutile, anatase, and brookite. More than 4 million tons of titanium dioxide are produced per year and it is widely used for industrial applications (paints, inks, plastics, textiles) and in small amounts as a food colorant. ° "° Production and properties — Titanium oxide is mainly produced from ilmenite, a titaniferous ore (FeTiOj). Rutile and anatase are relatively pure titanium dioxide (Ti02) forms. Titanium oxide pigment is produced via chloride or sulfate processes via the treatment of the titanium oxide ore with chlorine gas or sulfuric acid, followed by a series of purification steps. High-purity anatase is preferred for utilization in the food industry. It may be coated with small amounts of alumina or silica to improve technological properties. 

Zinc oxide occurs in nature as mineral zincite. It is the most important zinc compound and has numerous industrial applications. Zinc oxide is the pigment in white paints. It is used to make enamels, white printing inks, white glue, opaque glasses, rubber products and floor tiles. It is used in cosmetics, soaps, pharmaceuticals, dental cements, storage batteries, electrical equipment, and piezoelectric devices. Other applications are as a flame retardant, as a UV absorber in plastics, and a reagent in analytical chemistry. A major application of zinc oxide is in the preparation of most zinc salts. In medicine, the compound is used as an antiseptic, an astringent and a topical protectant. 

Use Pigment, white and opaque glass, base for color lakes, rubber, plastics, dyeing (hydrosulfite process), ingredient of lithopone, phosphor in X-ray and television screens, luminous paints, fungicide. 

Uses Pigment in white and opaque glass, plastics, rubber, dyeing, paints, linoleum, leather, dental rubber fluorescent pigment in paints and plastics ingred. of lithopone fungicide anhydrous in x-ray screens, TV screens flotation depressant for sphalerite ores flame retardant in plastics, elastomers, textiles, paper depilatory agent in cosmetics in food-pkg. adhesives filler in food-contact rubber articles for repeated use colorant in food-contact polymers in lubricants for incidental food-contact use... 

When white light shines on a plastic material, it may be absorbed, reflected, and/or transmitted. Absorption removes certain wavelengths those that remain are the color we see. Opaque pigments, insoluble in the polymer, reflect an opaque color to the eye. Transparent organic dyes, soluble in the polymer, transmit a see-through color to the eye. 

Titanium dioxide is used in tremendous tonnage (270 million pounds per year) both as opaque pigment and as white colorant in plastics. This is 90 percent of the inorganic... 

The main reason for incorporating pigments into plastics is to introduce colour (including black and white), either for aesthetic reasons and market appeal or because of functional demands. However, the optical role of a pigment can extend wider than simply providing colour, because it plays a decisive part in determining whether the medimn is opaque or transparent. 

Dyes can only absorb light and not scatter it. Thus the articles will be transparent. The optical effect of pigments is somehow different, so if the refractive index of the pigment appreciably differs from that of the plastic and for a certain specific particle size, reflectance of the light takes place, and thus the plastic becomes white and opaque, while if selective light absorption takes place, a colored and opaque article is obtained. 

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