Pigment metal chelate

Metal chelation is also a means of insoliihilizing organic molecules. For example. Cl Pigment Green 10 [51931 -46-5] (138) (Cl 12775) is a 2 1 nickel complex of a bidentate o-hydroxyazo ligand. 

The class of hydroxyanthraquinone pigments comprises two different groups of compounds metal complexes of hydroxyanthraquinones on the one hand and metal salts of hydroxyanthraquinone sulfonic acids on the other hand. Some of the products are metal chelates. 

There are many organic dyestuffs but only one class, that of the metal chelates, has been found to be active in electrocatalysis. The first compounds described were the phthalocyanines 1-4), which are similar in structure to the heme in the blood pigment, hemoglobin in both, the metal atom is surrounded by four nitrogen ligands. 

Other metal chelate pigments were patented around this period but did not lead to commercial products until recently. A specific example is Pigment Yellow 129 (XLI), which was not exploited for 30 years until Ciba-Geigy developed new processes and made improved products (55, 56). In addition, much work in this area has been carried out by BASF (XLIl) (57) and others. XLIII (58) and XLIV (59) are further examples from the patent literature. 

For example, meso-tetraaryltetrabenzoporphyrin zinc complex results from heat treatment of the corresponding 3-benzylidenisoindolinone with zinc benzoate l Appropriately substituted methine and azomethine isoindolinones featuring substructure 24 were also converted into stable metal chelate pigments of general structure 26 via a metal template reaction with aromatic and heterocyclic a-hydroxy aldehyde or ketone hydrazone derivatives incorporating the structural element 25 . ... 

Pigments (ZnO, Ti02, Fe203), stabilizers (metal chelates) and vulcanization promoters. 

More in-depth stabilization studies on a wide cross-sectional analysis of pigments have shown that in polypropylene film the following order in stability dominates anatase < pure polymer < rutile < cadmium yellow < copper phthalocyanine < azo yellow pigment (Monolite Yellow G). With metal chelate light stabilizers based on nickel and cadmium, variable stability effects were observed. In general most of the interactions with these pigments were antagonistic, particularly... 

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