Pigments definition

Classification Carotenoid pigment Definition Carotenoid pigment found mostly in animai organsims, but aiso occurring in plants Empirical C40H62O4... 

Classification Carotenoid pigment Definition A precursor of Vitamin A occurring naturally in plants Empirical C40H56... 

Classification Monoazo color organic pigment Definition Barium salt of D C Red No. 8 Empirical C17H12CIN2O4S ViBa Properties Powd. odorless insol. in water, most soivs. m.w. 444.46 Toxicology TSCA listed... 

Classification Inorg. mineral pigment Definition Sodium aluminum sulfosilicate complex obtained by chlorinating ultramarine blue at 300 C displacing part of the sulfur and sodium from the blue molecule... 

Hydroxide Fe(OH)3 (Fe + plus OH ) has definite existence and there are many ill-deiined hydrates used as pigments. FeOOH has two forms goethite and lepidocrocite. Colloidal Fe(OH)3 is easily obtained as a deep red sol. Many Fe(III) hydroxy complexes are known. Fe(OH)2 may be formed from Fe and OH" in the absence of O2 but it is very readily oxidized. 

Gonnet, J.R, Colour effects of co-pigmentation of anthocyanins revisited. 1. A colorimetric definition using the CIELAB scale. Food Chem., 63, 409, 1998. 

Infrared spectroscopy is a major tool for polymer and rubber identification [11,12]. Infrared analysis usually suffices for identification of the plastic material provided absence of complications by interferences from heavy loadings of additives, such as pigments or fillers. As additives can impede the unambiguous assignment of a plastic, it is frequently necessary to separate the plastic from the additives. For example, heavily plasticised PVC may contain up to 60% of a plasticiser, which needs to be removed prior to attempted identification of the polymer. Also an ester plasticiser contained in a nitrile rubber may obscure identification of the polymer. Because typical rubber compounds only contain some 50% polymer direct FUR analysis rarely provides a definitive answer. It is usually necessary first... 

While the properties of (soluble) dyes are determined almost exclusively by their chemical constitution, application characteristics of pigments—which are by definition insoluble in the medium in which they are applied (see Sec. 1.1) — are largely controlled by their crystalline constitution, i.e., by their physical characteristics. This is discussed in the next chapter. 

The surface area of a pigment, however, is not a definitive value it is controlled by factors such as the method of determination and the experimental parameters. Depending on the procedure, the experimental results may either reflect the exterior geometry of the pigment particles or also account for additional interior surface area, which is hard to define. Parameters such as the molecular size of the ad-... 

There is no precise definition for the frequently used term application fastness of a pigment. It usually refers to the behavior exhibited by a finished product used in accordance with the specifications. The term may thus refer to a print, a coated object, or a plastic product, and the list of features ranges from properties such as lightfastness and weatherfastness to migration fastness and fastness to solvents. In this context, there is a certain amount of emphasis on features which play a role in connection with packaging materials and packed articles. 

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