Insoluble pigments

It is quite stable, and is generally used as a pigment. Insoluble in water or alcohol, very slightly soluble in acetone producing a yellow colour. 

Pigment Insoluble material that is finely divided, micronized (for example), and uniformly dispersed in a formulated system for the purpose of coloring it or making it opaque. Examples Ti02 in soap bars and paints iron oxides in eye makeup and paints. 

To produce the broad variety of finished products fiom PVC formulations nearly always requires the incorporation of colorants. Most often, pigments (insoluble particulates) are employed in PVC rather than dyes, although the latter are employed in a few speeial cases. Pigments selected for use in PVC must be acid-degradation resistant, and can be added to the formulation as dry powders, dry dispersions, or concentrates in either liquid or solid carriers. The seleetion of the physical form of the colorant often depends on the formulation (e.g. rigid versus flexible), the compounding process, and the requirements of the appUcation. 

When white light shines on a plastic material, it may be absorbed, reflected, and/or transmitted. Absorption removes certain wavelengths those that remain are the color we see. Opaque pigments, insoluble in the polymer, reflect an opaque color to the eye. Transparent organic dyes, soluble in the polymer, transmit a see-through color to the eye. 

Pigment Insoluble, finely ground materials that give paint its properties of color and hide. Titanium dioxide is the most important pigment used to provide hiding in paint. Other pigments include anatase titanium, barium metaborate, barium sulphate, burnt sienna, burnt umber, carbon black, China clay, chromium oxide, iron oxide, lead carbonate, strontium chromate, Tuscan red, zinc oxide, zinc phosphate and zinc sulfide. 

Iron oxides are stable pigments insoluble in most solvents but usually soluble in hydrochloric acid. Those not soluble in HCl can be fused with potassium hydrogen sulfate, KHSO4, and then dissolved in water. 

Pigment Insoluble type, inert. two-part, acid-xinc... 

Recently, a very useful method for fabrication of TBPs for OFETs has been developed. TBPs are a new semiconductor for OFETs, compared to Pcs. TBPs and Pcs are pigments (insoluble in organic solvents) and it is not easy to get pure samples. Ito et al. have found that heating a porphyrin (CP) fused with bicyclo[2.2.2]octadiene (BCOD) gives TBP in quantitative yield (Scheme 3) [125]. As CPs are soluble in organic solvents, they are purified by column chromatography. 

Lead II) chloride, PbCl2. Insoluble cold water, sparingly soluble hot. Matlockite is PbFCl. PbCL forms many complex chlorides and also basic chlorides. Cassel yellow (approx. PbCl2 7PbO) is prepared by fusion of the constituents and is used as a pigment. 

The examples in the preceding section, of the flotation of lead and copper ores by xanthates, was one in which chemical forces predominated in the adsorption of the collector. Flotation processes have been applied to a number of other minerals that are either ionic in type, such as potassium chloride, or are insoluble oxides such as quartz and iron oxide, or ink pigments [needed to be removed in waste paper processing [92]]. In the case of quartz, surfactants such as alkyl amines are used, and the situation is complicated by micelle formation (see next section), which can also occur in the adsorbed layer [93, 94]. 

The FD C certified colors are all water-soluble dyes, but can be transformed into insoluble pigments known as lakes by precipitating the dyes with alurninum, calcium, or magnesium salts on a substrate of aluminum hydroxide. The lakes are useful in appHcations that require color whereas in dry form, such as cake mixes, or where water may be present and bleeding is a problem, such as food packaging. FD C Red Lake No. 3 was deHsted in Febmary... 

Alkali or alkaline-earth salts of both complexes are soluble in water (except for Ba2[Fe(CN)g]) but are insoluble in alcohol. The salts of hexakiscyanoferrate(4—) are yellow and those of hexakiscyanoferrate(3—) are mby red. A large variety of complexes arise when one or more cations of the alkah or alkaline-earth salts is replaced by a complex cation, a representative metal, or a transition metal. Many salts have commercial appHcations, although the majority of industrial production of iron cyanide complexes is of iron blues such as Pmssian Blue, used as pigments (see Pigments, inorganic). Many transition-metal salts of [Fe(CN)g] have characteristic colors. Addition of [Fe(CN)g] to an unknown metal salt solution has been used as a quaUtative test for those transition metals. 

Tripotassium hexakiscyanoferrate [13746-66-2] K2[Fe(CN)g], forms anhydrous red crystals. The crystalline material is dimorphic both orthorhombic and monoclinic forms are known. The compound is obtained by chemical or electrolytic oxidation of hexacyanoferrate(4—). K2[Fe(CN)g] is soluble in water and acetone, but insoluble in alcohol. It is used in the manufacture of pigments, photographic papers, leather (qv), and textiles and is used as a catalyst in oxidation and polymerisation reactions. 

Iron(III) hydroxide [1309-33-7], FeH02, is a red-brown amorphous material that forms when a strong base is added to a solution of an iron(III) salt. It is also known as hydrated iron(III) oxide. The fully hydrated Fe(OH)3 has not been isolated. The density of the material varies between 3.4-3.9 g/cm, depending on its extent of hydration. It is insoluble in water and alcohol, but redissolves in acid. Iron(III) hydroxide loses water to form Fe203. Iron(III) hydroxide is used as an absorbent in chemical processes, as a pigment, and in abrasives. Salt-free iron(III) hydroxide can be obtained by hydrolysis of iron(III) alkoxides. 

Lead Chloride. Lead dichloride, PbCl2, forms white, orthorhombic needles some physical properties are given in Table 1. Lead chloride is slightly soluble in dilute hydrochloric acid and ammonia and insoluble in alcohol. It is prepared by the reaction of lead monoxide or basic lead carbonate with hydrochloric acid, or by treating a solution of lead acetate with hydrochloric acid and allowing the precipitate to settle. It easily forms basic chlorides, such as PbCl Pb(OH)2 [15887-88 ] which is known as Pattinson s lead white, an artist s pigment. 

---