CHAPTER ONE:
1.0     INTRODUCTION
1.1BACKGROUND OF THE STUDY
Polymerization is one of the most industrial processes. Resins and emulsion are two main classes of polymer (Mark , 1964).
The term “alkyd” was originally used by kienle in 1927 to describe the reaction products of polyhydric alcohols and polybasic acids. Extensive commercialization of special classes of polymeric esters which are not recognised as alkyds has forced a more limited definition. For example, among the polymeric esters which are alkyds by kienle’s definition are the unsaturated polyesters polymerised with styrene and the saturated polyesters reacted with isocyanites.
The term “alkyd” now tends to specify polyesters. Products composed of polyhydric alcohols, polybasic acids, and fatty mono basic acids. These materials (alkyds) are used chiefly in the coatings industry where they form non-volatile binder (or vehicle) in the manufacture of paints and varnishes. In this industry, the term alkyd, alkyd resin, and alkyd solution are used interchangeably (Sanler,1998).
The term “modified alkyd” is associated with chemical modifications that are carried out during alkyd resin preparation and that incorporate chemical agents of types other than those included in the definition. For example, if the alkyd polyesters formation takes place in the presence of vegetable oil, the polyester product will possess fatty acids residues on its chain and the resin is called oil modified alkyd resin. On the other hand, when no fatty acids are used, or when they are completely replaced by other types of acids, the product can be considered as “oil-free” alkyds (Patlon,1972).
Alkyd resins are by far the most important class of coating resins. It is estimated that alkyd resins contribute about 70% to the conventional binders used in surface  coating is largely due to their unique properties such as film hardness, durability gloss and gloss retention, resistance to abrasion, impacted on them through modification with drying oil (Patlon, 1962).
Alkyd resins are used in both clear and pigmented, industrial and trade coating to protect and decorate a wide variety of substances. The industrial coatings or finishes generally are applied during the manufacturing process of the item which they cover. Often, they are specifically formulated to meet both conditions desired for their application and the endless use of the article of manufacture. The industrial finishes include primers and top coats for refrigerators, furniture and electrical equipment. In view of the development of these items and sectors, the positive growth is expected for paint industry (Waters, 1955).
Further, the paint industry envisages a future expansion in view of development in corrosion resistance coatings, expansion in housing activity and other industry uses. The demands of alkyd resin being an ingredient in paint, varnish and printing ink industry would be linked with the paint industry.