Hansa yellow

Monoazo Pigments. In combination with other groups, the a2o linkage, —N=N—, imparts color to many dyes and pigments (see Azo Dyes). The simplest of these, ie, the Hansa yellows, toluidine reds, and naphthol reds, do not have the lightfastness and heat stabiUty required for plastics. Permanent YeUow FGL and Permanent Red 2B are stable enough for vinyls, polyethylene, polypropylene, and ceUulosics (11). Permanent Red 2B is available as the calcium, barium, or manganese salt. 

Pigments derived from pyrazolones include Hansa Yellow R, l-phenyl-3-methyl-4-[(2,5-dichlorophenyl)azo]-5-hydroxypyrazole and Pigment Chrome Yellow, 1-phenyl-3-methyl-4-[(o-tolylazo]-5-hydroxypyrazole, as examples of monoazo compounds. 

Hansa Yellows, 1, 334 5, 299 Hantzsch synthesis, 2, 87-88 1,4-dihydropyridine, 2, 482 thiazoles, 6, 294-299 A -thiazolines, 6, 314 Hantzsch-Widman names parent names, 1, 35 stem suffixes, 1, 12 Hantzsch-Widman system nomenclature, 1, 11-12 Hardeners in photography... 

Methylene coupling components with carbonyl groups in a,a-positions are very important, particularly acetoacetanilide derivatives (Scheme 12-40, X=NHAr), for the production of yellow monoazo dyes and pigments (Hansa Yellows see Zollinger, 1991, p. 180). 

Handylab, 26 976 Hanford N reactor, 17 572-573 Hanford production reactors, 17 570 Hanksite, 5 785t Hansa yellows, 14 317 Hansch equation, 10 329 Hansenula polymorpha, 12 479 Hantaviruses, 3 137 Hantzsch pyridine synthesis, 16 550 Hantzsch-Widman nomenclature system, 17 399... 

Molecular dimerization, as in the transition from Hansa Yellow to disazo yellow pigments, increases the color strength considerably. A comparison of a Naph-thol AS/disazo condensation pigment pair gives similar results ... 

Yellow monoazo pigments were discovered by Meister Lucius Bruiting in Germany (later Hoechst AG) in 1909 and entered the market in 1910 under the trade name of Hansa Yellows . 

This compound has entered pigment history as Hansa Yellow G . The commercial varieties are products with comparatively coarse particle sizes and specific surface areas of approximately 8 to 30 m2/g. P.Y.l provides good hiding power, it is used primarily in air drying paints as well as in packaging and textile printing. 

The paint industry shows only limited interest in either P.Y.13 or 12. Although the redder varieties of P.Y.13 are more lightfast than the P.Y.12 types by a few steps on the Blue Scale, they do not reach the lightfastness of Hansa Yellow type monoazo pigments. P.Y.13 is not fast to overpainting. 

Simultaneously with Hansa Yellow G, compound 84 was first described as early as 1909 by Farbenfabriken Bayer. Its preparation starts from l-amino-4-bro-moanthraquinone-2-sulfonic acid (bromamine acid) 85. Dimerization is achieved through the Ullmann reaction, i.e., treatment with fine-grain copper powder in dilute sulfuric acid at 75°C. The separated intermediate, the disodium salt of 4,4 -diamino-l,l -dianthraquinonyl-3,3 -disulfonic acid 86, is heated to 135 to 140°C in the presence of 80% sulfuric acid in order to cleave the sulfonic acid groups [7] ... 

Hansa yellow org chem Group of organic azo pigments with strong tinting power, but poor opacity in paints used where nontoxIcIty Is Important. han-sa yel o ) Hantzsch synthesis org chem The reaction whereby a pyrrole compound is formed when a p-ketoester, chloroacetone, and a primary amine condense. hansh, sin-tha-sas ... 

Hansa Yellows. Hansa yellows are quite opaque when compared to the other organic family yellows. Hansa yellows as a family are known as potentially significant bleeders. This limits their use in most thermoplastics. Hansa yellows do have utility in some thermoset plastics. Care should be exercised when contemplating the use of Hansa yellow s in polymers. Hansa yellow s popularity and great usage is in coating applications. 

Technical Observations. Permanent red 2G (lithol fast orange R) is, like Hansa yellow, a valuable pigment color having outstanding fastness to light and very good oil and spirit fastness. 

H add, see l-Amino-8-naphthol-3,6-disulfom c add Halogenation, general, 65 Halogen atoms active, 85, 103 introduction, 9 Halogen carriers, 66 Hansa yellow, 133, 143, 266 Helian ine, 275 Helio Bordeaux BL, 268 Heliogen blue B, 338 Hemp, 368... 

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