Pigments major producers

There are only four major producers of high-grade ultramarine pigments -Dainichi Seika (Japan), Nubiola (Spain), Prayon (Belgium) and Reckitt s Colours (France, United Kingdom) - with two smaller producers in Austria and Colombia. In 1990 total worldwide production was ca. 20000 t/a. 

Factories in the People s Republic of China, and India produce on the whole laundry grade materials. There are only three major producers of high-grade ultramarine pigments - Holliday Pigments (United Kingdom, France), DKK (Japan), and Nubi-ola (Spain, Romania, India, Colombia). In 2000 total worldwide production of all ultramarine was ca. 25,0001 a f... 

The scope of operations is outlined in the CER, and in view of the small product range the depth of information given is considered adequate. The group is a major producer of titanium dioxide, which is the premier white pigment used in paints, plastics, paper, printing inks, ceramics, food, cos metics and textiles. Co-products manufactured and marketed include iron chemicals and gypsum. 

Gum arabic is a tree exudate of various Acacia species, primarily Acacia Senegal, and is obtained as a result of tree bark injury. It is collected as air-dried droplets with diameters from 2-7 cm The annual yield per tree averages 0.9-2.0 kg. The major producer is Sudan, with 50-60,000 t/annum, followed by several other African countries. Gum arabic has been known since ancient Eg)q)t as kami , an adhesive for pigmented paints. 

Iron Blocks. Chemically, iron blacks are based on the binary iron oxide, FeOFe2 O3. Although the majority is produced in the cubical form, these can also be produced in acicular form. Most of the black iron oxide pigments contain iron(III) oxide impurities, giving a higher ratio of iron(III) than would be expected from the theoretical formula. 

Besides its biological significance, the silkworm has economic value. Silk has been a major natural fiber used in textile production for millennia. By utilizing CBP, coloration of a natural fiber by transport of a natural pigment based on molecular genetic engineering has been achieved (Sakudoh et al. 2007). Determination of other genes for cocoon color may lead to the ability to produce custom-colored silks, which may have an impact on the textile industry. 

Aromatic aminosulfonic acids, which play a major role in connection with pigment lakes, are produced by sulfonating the corresponding nitro compound and then reducing it to an aminosulfonic acid. An alternative technique, known as baking process, involves exposing an amine/dihydrosulfate to a temperature of 200 to 300°C in order to effect rearrangement to p-aminosulfonic acid. Ortho-sulfonation prevails if the para position is occupied. In contrast to sulfonation techniques with sulfuric acid, this method avoids wastewater contamination with sulfuric acid. 

Today, 80 years after their discovery, Naphthol AS pigments continue to play a major role among organic pigments. Although comparatively many derivatives are known, only few are produced in large volume. 

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