there is a variety of isocyanate reactions, both one-pack and twopack polyurethane paints are available. These paints have many good properties; toughness, hardness, gloss, abrasion resistance, as well as chemical and weather resistance. Polyurethanes are not used under water on steel ships, only on superstructures, etc., but they are very popular on yachts where their good gloss is appreciated.
(v) Vinyl resins Vinyl resins are obtained by the polymerization of organic compounds containing the vinyl group.
The solids content of these paints is low; therefore the dry film is thin, and more coats are required than for most paints. As vinyl resin paints have poor adhesion to bare steel surfaces they are generally applied
over a pretreatment primer. Vinyl paint systems are among the most effective for the underwater protection of steel