Compounding coloring

Dyes and Pigments. Several thousand metric tons of metallated or metal coordinated phthalocyanine dyes (10) are sold annually in the United States. The partially oxidized metallated phthalocyanine dyes are good conductors and are called molecular metals (see Semiconductors Phthalocyanine compounds Colorants forplastics). Azo dyes (qv) are also often metallated. The basic unit for a 2,2 -azobisphenol dye is shown as stmcture (11). Sulfonic acid groups are used to provide solubiHty, and a wide variety of other substituents influence color and stabiHty. Such complexes have also found appHcations as analytical indicators, pigments (qv), and paint additives. 

Why are some organic compounds colored while others aren t /3-Carotene, the pigment in carrots, is purple-orange, for instance, while cholesterol is colorless. The answer involves both the chemical structures of colored molecules and the way we perceive light. 

The precipitation diagram shown in Figure 4.3 enables you to determine whether or not a precipitate will form when dilute solutions of two ionic solutes are mixed. If a cation in solution 1 mixes with an anion in solution 2 to form an insoluble compound (colored squares), that compound will precipitate. Cation-anion combinations that lead to the formation of a soluble compound (white squares) will not give a precipitate. For example, if solutions of NiCl2 (Ni2+, Cl- ions) and NaOH (Na+, OH- ions) are mixed (Figure 4.4)—... 

Some rare earth compounds are used in glassmaking. Cerium is the most abundant, and its compounds are used to polish glass. Lanthanum compounds are used in making glass lenses, and praseodymium compounds color glass green. 

Fig. 15.22 Display of predicted Hansch parameters of the sum of inductive and resonance constants (F + R) versus lipophilicity (jr) for 302 commercially available carboxylic acids, acid chlorides, sulphonyl chlorides and isocyanates. Symbol size corresponds to larger molecular size (MR). Circles represent the selected R groups and triangles represent the unselected compounds. Colors convey the segmentation of the diversity reagents into nine sectors for selection.

Figure 2.2 Idealised absorption spectra of single compound colorants.

Zollinger H. Color of Organic Compounds. Color Chemistry Synthesis, Properties, an Applications of Organic Dyes and Pigments, 3" Ed. Wiley-VCH Zurich, 2003 1, 3-146. 

Solid compound Color Ionized Cl Formulation as Complex... 

Compound Color Melting point, °C Symmetry Space group or structure type Density. g/mL... 

Volatile colors, especially chromium compound colors, may migrate from one clay piece to another, staining the glazes. 

Bernard Mark Heron was born in Workington, England in 1965. After graduation (GRSC) from Lancashire Polytechnic (Preston) in 1987 and a brief period in industry he obtained his PhD (CNAA) in Benzothiopyran Chemistry in 1992 under the supervision of Professor John Hepworth at the University of Central Lancashire. A postdoctoral fellowship in heterocyclic chemistry (1992-95) and an industrially funded lectureship at Central Lancashire (1995-98) were followed by appointment to a James Robinson Lectureship at the University of Hull (1998-2000). Dr. Heron was appointed as a senior lecturer (2000-present) in the Department of Colour and Polymer Chemistry at the University of Leeds. His research interests include the chemistry and applications of heterocyclic compounds, color chemistry, and organic photo- and thermochromic materials. 

Compound Color/state m.p, (°C) Sublim. temp. (°C) Solubility 1 Ref. 

Color adds a subjective aspects to the quality of compounded products. Clear targets must be established for the desired color when the initial match is performed. When the match is approved, a specification needs to be established that reflects the target and an allowable variation for the compounded color. 

Among the data collected are the identity of the material(s), amount of material released and to which medium (media) it is released, the name and location of the POTW and/or other disposal facility that treats the substance or its ultimate disposal location, and estimated future releases. There is one important distinction between the Tier I/II and theTRI reports. The inventory reports are concerned with the total amount of material stored.TheTRI report details the amount of substance released, but in the case of metal-containing colorants, it is necessary to track the amount of compound (colorant) used to determine whether you have exceeded the reporting threshold. You must then convert the compound to the actual parent metal(s) for purposes of reporting. 

Both of these dyes, that from m-phenylenediamine and that from toluylenedi-amine, are used in large quantities in the preparation of compound colors. 

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