Color compound, chemical stability

In context with the formation of peraminosubstituted 1,4,5,8-tetraazaful-valenes of type 85 it must be mentioned that the bis-vinylogous compounds 94 can be easily prepared by reaction of acetamidine with bisimidoylchlo-rides derived from oxalic acid (96S1302). In the course of a complex reaction a cyclic ketene aminal was produced it immediately underwent an oxidative dimerization to yield deeply colored TAFs. Tlieir high chemical stability can be compared with that of indigoid dyes and manifests itself, for example, by the fact that they are soluble in hot concentrated sulfuric acid without decomposition. Tire same type of fulvalene is also available by cy-... 

The continually increasing importance of iron oxide pigments is based on their nontoxicity chemical stability wide variety of colors ranging from yellow, orange, red, brown, to black and low price. Natural and synthetic iron oxide pigments consist of well-defined compounds with known crystal structures [3.1] ... 

Extremely important for the safe handling of such pyrotechnic mixtures are, in addition to the chemical stability (compatability with the binder and other additional compounds) particular the thermal stability and the lowest possible impact, friction and electrostatic sensitivities. Figure 2.18 shows an example of a DSC ther-mogramm (Differential Scanning Calorimetry), which shows that the new environmentally friendly red mixture (colorant components from Figure 2.17) is thermally... 

Terpene-based resins are obtained from turpentine sulfate, a byproduct of the paper industry, and from limonene, a product of the citrus industry. Products obtained are alpha-pinene, beta-pinene, and dipentene. The alpha-pinenes are apparently the preferred product for hot melt adhesives as they are the most compatible with EVA copolymers. Adhesives compounded with dipentenes have excellent color and thermal stability, odor, oxidation resistance and hot tack properties. Typical of the products available in this class are the Piccolyte series of resins (Hercules). Limonene-based products are exemplified by Zonatac 105 (Arizona Chemicals). 

Chlorinated polyether is formulated particularly for products requiring, good chemical resistance. Other materials exhibiting good chemical resistance include all of the fluorocarbon plastics, ethylpentenes, polyolefins, certain phenolics, and diallyl phtha-late compounds. Additives such as fillers, plasticizers, stabilizers, colorants, and type catalysts can decrease the chemical resistance of unfilled plastics. Certain chemicals in cosmetics will affect plastics, and tests are necessary in most cases with new formulations. Temperature condition is also very important to include in the evaluation. Careful tests must be made under actual use conditions in final selection studies. 

Stannic chloride, SnCLp a fuming liquid, is used in the preparation of organic compounds and chemicals to weight silk and to stabilize perfumes and colors in soap. 

Special consideration should be paid to metal complexes such as azomethine pigments (Sec. 2.10). At high temperatures, the yellow copper complex with the chemical constitution 10, incorporated in PVC, will exchange its chelated copper atoms with the metal atoms present in the application medium. Stabilizers containing barium/cadmium or lead produce yellow shades, while dibutyl tin thiogly-colate or other tin compounds produce a brilliant medium red. Color change is slow at low temperatures, but at 160°C the effect is rapid [108],... 

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