Flavanthrone yellows

A number of vat dyes developed originally for textile applications are suitable, after conversion into an appropriate pigmentary physical form, for use in many paint and plastics applications. Examples of these so-called vat pigments include the anthraquinones, Indanthrone Blue (215, C. I. Pigment Blue 60) and Flavanthrone Yellow (216, C. I. Pigment... 

Flat plate, flow parallel to, 15 7191 Flat-screen printing, 26 398 Flat wall paint, 7 137-139 Flavanthrone dye, 9 336 Flavanthrone Yellow, pigment for plastics, 7 366t... 

Flavanthrone Yellow, the only commercially used flavanthrone, is a moderately brilliant reddish yellow. Excellent lightfastness and weatherfastness, combined with good solvent and migration resistance, make this pigment an attractive supplement to Anthrapyrimidine Yellow, mainly in the automotive finish industry. 

Flavanthrone Yellow, together with its chemical structure, is listed in the Colour Index under Constitution No. 70600. It was temporarily known as Pigment Yellow 112, but now it is exclusively referred to as Pigment Yellow 24. Since some time sales products of P.Y.24 are not listed anymore in the catalogues of the manufacturers, but the grades are still available on the market. 

High transparency makes P.Y.24 a valuable pigment for metallic finishes. It is used in relatively light shades, typically at a ratio of one part of color pigment to three parts of aluminum pigment. Thus prepared systems demonstrate excellent weatherfastness. Flavanthrone Yellow, like P.Y.108, tends to seed (Sec. 3.7.3.1). The pigment is heat stable up to 200°C and thus satisfies all possible heat stability requirements in this area. Flavanthrone Yellow is used in various industrial paints, especially in automobile O.E.M. finishes and in automotive refinishes. 

Flavanthrone Yellows. This high-performance red-shade yellow is mainly used in coatings. It is thought of as a very lightfast yellow. It provides the same performance in plastics, where durability is required. However, with all the other high-performance yellows available, flavanthrone yellow has enjoyed only partial success in plastics applications. 

Synonyms Cl 70600 Flavanthrone yellow Indanthrene yellow G Pigment yellow 24 Vat yellow 1... 

Flavanthrone yellow. See Flavanthrone Flavaxin. See Riboflavin Flavianic acid, disodium salt Flavianic acid, sodium salt. See Acid yellow 1 Flavin mononucleotide. See Riboflavin 5 -phosphate... 

CdS (acid-sensitive), Fe203 jcH20, PbCr04 (chrome yellow), benzidine yellow, flavanthrone yellow Pigments from the anthraquinone group... 

Flavanthrone was first synthesised by R. Bohn in 1901 along with indanthrone and has been used for a long time as a vat dye as weU as a pigment. Listed by the Colour Index (1971) as Cl 70600/Pigment Yellow 24 (Herbst and Hunger, 1997 however, some sources such as Wich, 1973 refer to it as Cl Pigment YeUow 112). Sometimes known as flavanthrone yellow. 

For health safety reasons, the lead based chrome yellows and oranges have been replaced by the much more expensive flavanthrone yellows, perinone and indo oranges. 

P.Y.179, an isoindolinone/cobalt complex pigment, was introduced to the market only few years ago but the production has recently been discontinued. It was recommended for use in paints, especially in automotive finishes. The pigment produces a reddish yellow shade. High lightfastness and excellent weatherfastness are an asset in pastel colors. Besides, good transparency made P.Y.179 a suitable product for metallic finishes. Yet, it is not quite as weatherfast as the equally reddish yellow P.Y.24, a flavanthrone pigment. 

The crude pigment may also be treated with an aromatic sulfonic acid (such as toluene sulfonic acid, xylene sulfonic acids, m-nitrobenzene sulfonic acid) in sulfuric acid or with nitric acid at 80°C to yield a somewhat redder yellow transparent modification of flavanthrone [22],... 

Other five-membered heterocycles such as thiophenes, thiazoles and oxazoles have been successfully annellated in the anthraquinone series. For example, the yellow dye (12) may be prepared from 2,6-diaminoanthraquinone by condensation with benzotrichloride and sulfur. Similarly, the six-membered heterocycles acridines, quinoneazines, pyrazines, acridones and pyrimidines are frequently incorporated (B-52MI11201). In fact, the best known of the anthraquinone vat dyes are indanthrone (13) and flavanthrone (14). The former anthraquinoneazine, a beautiful blue, which was the first such structure to be manufactured on a large scale, may be prepared by alkali fusion of 2-aminoanthraquinone at 220 °C (27MI11200). Treatment of 2-aminoanthraquinone in nitrobenzene with antimony pentachloride yields the yellow flavanthrone (14), the structure being confirmed by Scholl (07CB1691). Both indanthrone and flavanthrone and their derivatives have attracted considerable commercial attention. 

The early anthraquinone vat dyes were all blue or greenish-blue shades, but the fusion of 2 amino-anthraquinone at higher temperatures produced a yellow vat dye known as Flavanthrone or Indanthren Yellow G (C.I. VAT YELLOW 1), (19) ... 

Structures XVII and XVIII show two outstanding yellow vat pigments, flavanthrone, Pigment Yellow 24 (XVII), and anthrapyrimidine, Pigment Yellow 108 (XVIIll. Unfortunately, high cost has drastically reduced their usage today. 

Indanthrene brown R. See Vat brown 3 Indanthrene brown BR. See Vat brown 1 Indanthrene golden yellow. See Vat yellow 4 Indanthrene yellow G. See Flavanthrone Indanthrone CAS 81-77-6... 

Pigment yellow 24. See Flavanthrone Pigment yellow 31. See Barium chromate Pigment yellow 32. See Strontium chromate Pigment yellow 33. See Calcium chromate Pigment yellow 34. See Lead chromate. 

Cerium sulfide Cobalt aluminum oxide D C Red No. 7 Flavanthrone Indanthrone Iron oxide black Iron oxide brown Iron oxide red Iron oxide yellow Iron oxide yellow monohydrate... 

Chloroanthraquinone is especially useful as a base material for the production of 2-aminoanthraquinone, from which the vat dye indanthrene (Vat Blue 4) is produced by a method discovered by Rene Bohn in 1901, involving a reaction in alkaline solution with atmospheric oxygen in the presence of potassium nitrate at 150 to 200 °C. At higher temperatures and using antimony-(V)-chloride or aluminum chloride, flavanthrone (Vat Yellow 1) is obtained this is nowadays produced from l-chloro-2-aminoanthraquinone and PA. 

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