Introduction

Pigments are essential ingredients of many chemical coatings because, as insoluble particulates, they incorporate both color and body, but the requirements for these and other functional properties vary widely depending on the intended end use. For example, the long-term permanency demanded of exterior coatings may be of secondary importance for publication printing inks, whereas very poor permanency to oxidizing or reducing agents is a primary requisite of safety check inks. Hiding power is an important property for many paints and printing inks, but transparency is preferred for lacquers and inks used in four-color process printing. Clearly, there can be no ideal pigment for all purposes. The many and diverse end uses of modern chemical coatings, coupled with ever increasing demands that they be available in an array of bright colors, have resulted in an extremely broad palette of pigments from which the formulator can choose. Not counting metallized variations or obsolescent products, over 800 generic pigments are listed in the internationally recognized registry of colorants, the Colour Index TM, published jointly by the British based Society of Dyers and Colourists and the American Association of Textile Chemists and Colorists. Hues include 29 Black, 65 Blue, 32 Brown, 33 Green, 3 Metal, 68 Orange, 263 Red, 58 Violet, 17 white, 197 Yellow

This profusion of available products, while of natural interest to technical staff, creates a burden on those concerned with responding to requests for product safety information, inventory reporting, and other tasks of a regulatory nature. It is for these reasons that pigments were selected as the fourth topic in the Raw Materials Data Handbook series.

This volume covers the properties of over 250 generic pigments utilized in the formulation of printing inks, paints and related chemical coatings. The extensive data compiled should prove useful both for formulation and regulatory purposes, especially since they are frequently interrelated. The data presentations are preceded by an explanation of the Handbook's organization and of the properties compiled.

Data compiled

The Raw Materials Data Handbook series is intended as a convenient reference guide to selected regulatory matters at the federal level and, to the extent warranted, to technical performance properties.

As a class, pigments are non-volatile, non flammable, and nonreactive, and most of them are regulated by OSHA under the general category of "nuisance dusts." For these reasons, the OSHA/MSDS format adopted for the previous Handbook volumes was not retained. On the other hand, the manufacture of some pigments involves the use of heavy metals or other inorganic compounds of the type that, during the past decade, have been subjected to a growing number of regulations. It is these components that formed the basis for the selection of regulatory data to be covered. Included are the OSHA workplace standard; several environmentally oriented regulations of EPA (under RCRA, CWA, and TSCA); consumer oriented standards of CPSC, ANSI, and FDA; and, for the first time, an international regulation that on labeling imposed by EU. Also compiled is information from safety and toxicological studies reported for specific pigments.

Of the many raw materials utilized in the formulation of chemical coatings, the proper selection of pigments requires the most information on a variety of technical performance properties. Accordingly, the technical data part of the compilation is particularly extensive. Included are color properties by means of typical spectral curves; 10 types of physical properties; fastness to a total of 20 chemicals, solvents and other substances; and color permanency to light, weather, and heat. The compilation also includes principal uses, major weaknesses, available physical forms, and sources of supply in the USA. The compilation is based on a generic approach. The principal name and the method for classification are patterned after the system adopted by the Colour IndexTM Online. Also given, where available or applicable, are names and numbers in the systems developed by Chemical Abstracts, by FDA, and in the case of mixed metal oxides, by DCMA.

Through the Colour IndexTM Online and other published sources, the chemical synthesis and constitution of the majority of generic pigments are reasonably well known. Not so well known is how to prepare these chemical compounds in the optimum state for use as pigments. This aspect lies in the private realm of the pigment manufacturer, who may employ proprietary procedures or minor additives to make the pigment "work" or to maintain color control. It is therefore understood that all identity data refer to the base pigment and not necessarily to the commercial pigment in toto.

Data not compiled

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