Coatings generic types

In practice, the selection of coatings is often the opposite to what might be expected. There is a multitude of proprietary materials but the choice of generic types is limited. Section 12.3 of this chapter is designed to illustrate the basic properties of these generic types as a preliminary guide to selection by the engineer. The specifiers tend to examine the available materials to see if they will fit the requirements, rather than vice versa. 

Design of the tank (accessibility, crevices, shielded areas, baffles, and compartments). Present and future conditions of the coating and the generic type of coating employed. Whether the water is subject to freezing. 

Good adhesion of primers to metal substrates can best be achieved by ensuring cleanliness of the metal surface and by selection of generic coating primer types based on binders with chemical groups that can bond strongly to surfaces. 

The API RP 652 standard [7] recommends the use of coating systems based on two generic types, epoxy and polyester. This standard does not deal with the following items ... 

Thousands of coatings and paint products are sold for industrial applications, making it impossible to memorize their names, attributes, properties, and limitations. Therefore, a classification method is needed based on some similarities. The most common method of classification is to refer to the chemical attribute— most often the resin type— that is unique to a group of coatings. This is the most useful classification system because coatings of the same generic type have similar handling and performance properties. This is based on the binder (resin) used in the formulation. 

Alternatively, some coating systems are characterized by the application method used. For example, for coil-coated metal sheet (commonly steel or galvanized steel), very specialized high-speed roller application equipment is used to coat the sheet steel as it is unwound from a coil. The paint used in the coil-coating process can be of virtually any generic type, although alkyds, polyesters, epoxies, and zinc-rich epoxy coatings are the most prevalent. 

The generic name hydrocarbon resins designates several families of low molar mass polymers (M from 600 to 104) obtained by polymerization of petroleum, coal tar, and turpentine distillates [80-82], In most cases, these products are obtained by cationic polymerization of mixtures either of aliphatic and/or aromatic mono and diolefins present in the more or less enriched Cs and C9 feedstreams, or of pure aromatic monomers generally of the styrene type. They are complex mixtures of polymers ranging from viscous liquids and tacky fluids to hard, brittle thermoplastics, and are used as additives in adhesives, printing inks, rubbers, coatings, etc. [80-82], They are obviously amorphous and are characterized by their softening point (0 to —150° C), determined by standardized methods (i.e.,... 

An essential element of the CVD process is the chemical reaction that occurs to produce the coating/film. The precursors that constitute the chemical reactants must, of course, contain the chemical elements that will ultimately constitute the coating. In addition, these precursors must be stable at room temperature, react cleanly in the reactor without side reactions, not condense in the transfer lines, and be easily produced. The number of CVD reactions that are currently used is quite extensive and a complete listing of every reaction is beyond the scope of this review. However, a classification according to the method to activate the reactions for generic reaction type with specific examples is given in what follows. This will provide the reader with an overview of the diversity of applications of CVD. 

After the first patents of the coated cellulose- and amylose-type CSPs expired in 2006 a series of generic CSPs have been introduced into the market. The main arguments for choosing one of these phases for a preparative separation process should be the loadability and stability of the stationary phase beside the price per... 

The chart on the following page may assist in paint evaluation it lists coil-coating finishes and comparative properties of some of the most popular generic coating types. It is available to assist prospective users of prepainted metal in a number of ways. 

Since resin type determines the performance properties of a coating, it is used most often. Table 10.6 shows the physical, environmental, and film-forming characteristics of coatings by polymer (resin) type. It is important to realize that in selecting coatings, tables of performance properties of generic resins must be used only as guides because coat-... 

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