Pigments application problems

From World War I to World War II the channel black process made most of the carbon black used worldwide for mbber and pigment applications. The last channel black plant in the United States was closed in 1976. Operations still exist and are even being expanded in Europe. The demise of channel black was caused by environmental problems, cost, smoke pollution, and the rapid development of oil-fumace process grades that were equal or superior to channel black products particularly for use in synthetic mbber tires. 

Quite apart from the problems of chemical synthesis, it is clear that the application of physico-chemical methods to pigment manufacture, first needed in the development of the... 

This section will discuss some important concepts from coloristic practice and the optical properties of pigmented systems. Space considerations permit a treatment of only the most vital concepts. The reader must consult the literature for further details and accounts of special problems [1], A review on the effect of crystal structure on color application properties was published [2],... 

Manufacturers of organic pigments frequently use additives in an attempt to improve parameters such as the wetting time and wetting volume and thus to enhance the dispersibility of their products. The decision about each individual approach is usually made on the basis of empirical data concerning the application properties of the products. This is understandable in view of the fact that the dispersibility of a pigment is known to depend on its medium and on the conditions under which it is applied, a problem that is so complex that it is solved best by carrying out a series of pilot scale experiments in different vehicles. 

These requirements considerably restrict the selection of pigments for oven drying systems. The complex nature of the problem makes it necessary to submit any pigment which is basically applicable to a pilot experiment under the exact processing conditions. 

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