Other Polymers and Emulsions

While most trade sales paint is water based, satisfactory water-based polymers with the required properties have not yet been developed for industrial coatings. Nevertheless, much progress has been made, and satisfactory water-reducible coatings have been made for many industrial applications. 

Some types of polymers, sueh as acrylates, methaerylates, and aery-lonitriles, can be blended or eopolymerized to obtain speeial properties. 

The basic difference between lacquer and solvent-based paint is that lacquer dries by evaporating the solvent, while paint relies on a combination of oxidation and polymerization. Dryers are used to hasten the drying process. Without these additives, paint would dry in days instead of hours, and in many cases, the film would be softer and have poorer resistance properties. 

The cobalt drier containing 6 to 12% metal cobalt is the most powerful drier used by the coatings industry. It acts as an oxidation catalyst, and it is known as a top drier, diying the top of the film. Excessive amounts of cobalt drier will create stresses and strains in the paint film that can result in wrinkling. Though purple in color, cobalt has low tinting strength and will not discolor a paint. 

This drier is normally available in strengths containing 24 or 36% metal lead. It is very light in color and thus does not discolor a paint. Lead is a polymerization catalyst and therefore makes an ideal combination with cobalt, since it tends to harden or dry the bottom of the film. Because of lead laws, this 

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