Synthetic pigments

Colorants For identification purposes and visual marketing values Natural pigments Synthetic dyes... 

Methyl hydroxyethylcellulose pigment, synthetic rosin systems Mciotatanc5 pigment, tank coatings... 

S -tetrakis (4-carboxyphenyl) porphyrin (TPPC) is used as the model pigment. Synthetic sequential polypeptides (PP) / / composed from Lys, Leu, Ala,Gly are used as model part of complexes ... 

Inorganic and organic natural pigments, synthetic pigments... 

Aflatoxins, alkaloids, anabolic compounds, barbiturates, benzodiazepines, bile acids, carbohydrates, etheric oil components, fatty acids, flavanoids, glycosides, lipids, mycotoxins, natural pigments, synthetic dyes, nitroanilines, nucleotides, peptides, pesticides, steroids, sulfonamides, surfactants, sweetenCTS, tetracyclines, vitamins... 

Pigment. Synthetic organic pigments are inert, stable, coloured substances insoluble in water and organic solvents, such as the oils commonly used as vehicles in paint manufacture. They are used also in the mass coloration of plastics. Physical form is of paramount importance in ensuring maximum colouring power and reflectance. 

This is the largest class of synthetic iron oxide pigments. Synthetic red iron oxide pigment corresponds to the natural mineral hematite. It is prepared by mainly four processes ... 

The main contribution to opacity has to come from the pigments. Synthetic products are usually less opaque than natural products and this can be a problem, especially when coating ULWC (ultra Hght weight) grades of paper. Products with a very pronounced thickening effect are only added in small quantities, so they hardly have any effect on opacity. 

Although rosiaite is unlikely to be encountered as a pigment, synthetic lead antimony oxide q.v.) analogues, notably forms containing tin, are known as yeUow pigments. 

Bieganska et al. (1988) as metal flake pigment Synthetic analogue... 

Frondel (1950) Frondel, C. On paratacamite and some related copper chlorides M/nero/ogica/ Magazine 29 (1950) 34A5 Frondel (1962) Frondel, C. Amer. Min. 47 (1962) 781 Fujita et al. (1977) Fujita, T. Kawada, L. Kato, K. Raspite from Broken Hill cia Crystallographica B33 (1977) 162-163 Fuller (1973) Fuller, C.W Colored Iron Oxide Pigments, Synthetic Pigment Handbook 1 Patton, T.C. (ed.) John Wiley, NewYork (1973) 333-349... 

Qumones are colored p benzoqumone for example is yellow Many occur natu rally and have been used as dyes Alizarin is a red pigment extracted from the roots of the madder plant Its preparation from anthracene a coal tar derivative m 1868 was a significant step m the development of the synthetic dyestuff industry... 

Animals that do not readily accept pelleted feeds may be enticed to do so if the feed carries an odor that induces ingestion. Color development is an important consideration in aquarium species and some animals produced for human food. External coloration is desired in aquarium species. Pink flesh in cultured salmon is desired by much of the consuming pubHc. Coloration, whether external or of the flesh, can be achieved by incorporating ingredients that contain pigments or by adding extracts or synthetic compounds. One class of additives that imparts color is the carotenoids. 

H. A. hubs, ed.. The Chemistry of Synthetic Dyes and Pigments, American Chemical Society Monograph Series, Reinhold Publishing Corp., New York, 1955. 

In a number of cases, identifications have been extremely difficult, because the materials were synthetic and knowledge of their existence had actually been lost. For example, several rather commonly encountered synthetic pigments, such as the lead-tin yellow often found in Renaissance and Baroque paintings, were originally misidentified or left unidentifiable until extensive research, including analyses of elemental composition and chemical and physical properties, and repHcation experiments, led to proper identification of the material and its manufacturing process. 

The medium is the binder which provides for the adhesion of pigments. The most important types are the temper media (glue, egg, and gum), the oils, and wax. In addition, for wall painting there is the tme fresco technique, where the pigments are laid down in a fresh, wet plaster preparation layer. Several other media have been used, but much less frequendy, eg, casein temper. In modem paints, a number of synthetic resins are used for this purpose. Contemporary artist paints are often based on acryhc polymers (see Acrylic ester polymers Paints). 

A process has been developed by J. M. Huber Co. to treat kaolin clay pigments using a hydrothermal process (see Clays) (25). The products, called synthetic alkah metal aluminosihcates (SAMS), have superior pigmentary quahties for paper (qv) coating. 

In recent years, synthetic polymeric pigments have been promoted as fillers for paper. Pigments that ate based on polystyrene [9003-53-6] latexes and on highly cross-linked urea—formaldehyde resins have been evaluated for this appHcation. These synthetic pigments are less dense than mineral fillers and could be used to produce lightweight grades of paper, but their use has been limited in the United States. 

Phthalocyanine Dyes. In addition to their use as pigments, the phthalocyanines have found widespread appHcation as dyestuffs, eg, direct and reactive dyes, water-soluble dyes with physical or chemical binding, solvent-soluble dyes with physical or chemical binding, a2o reactive dyes, a2o nonreactive dyes, sulfur dyes, and wet dyes. The first phthalocyanine dyes were used in the early 1930s to dye textiles like cotton (qv). The water-soluble forms Hke sodium salts of copper phthalocyanine disulfonic acid. Direct Blue 86 [1330-38-7] (Cl 74180), Direct Blue 87 [1330-39-8] (Cl 74200), Acid Blue 249 [36485-85-5] (Cl 74220), and their derivatives are used to dye natural and synthetic textiles (qv), paper, and leather (qv). The sodium salt of cobalt phthalocyanine, ie. Vat Blue 29 [1328-50-3] (Cl 74140) is mostly appHed to ceUulose fibers (qv). 

Use. Titanium dioxide is mainly used in the production of paints and lacquers (55—60%), plastics (15—20%), and paper ( 15%). Other apphcations include the pigmentation of printing inks, mbber, textiles (qv), leather, synthetic fibers, ceramics, white cement, and cosmetics. 

About 60% of the natural iron oxide pigments is used to color cement and other building materials (qv). About 30% is consumed in the production of paints. For coloring plastics and mbber, synthetic iron oxide pigments are preferred. The main advantage of the natural iron oxide pigments, as compared to the synthetic ones, is cost. However, the quaHty is inferior, and in most cases, they are consumed in close proximity to the mines. As colorants, the natural iron oxides are about 50% weaker than synthetically produced iron oxides. 

Synthetic Iron Oxides. Iron oxide pigments have been prepared synthetically since the end of the seventeenth century. The first synthetic red iron oxide was obtained as a by-product of the production of sulfuric acid from iron sulfate containing slate. Later, iron oxide pigments were produced direcdy by the thermal decomposition of iron sulfates. In the 1990s, about 70% of all iron oxide pigments consumed are prepared synthetically. 

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