Definitions for "Alkyds"
Keywords:  enamels, alkds, chch, cooch, diallyl
Resins used mostly in trim paints, inside and out, although some medium duty equipment and marine enamels employ these resins as binders. Most often alkyd resins are found in vehicles employing aliphatic hydrocarbons (mineral spirits or other refined petroleum distillate) as thinner. Alkyds offer good leveling properties and cure to a relatively durable film, but tend to yellow interior and embrittle with age. Color and gloss exterior is only fair, and alkyds are highly prone to failure exterior on surfaces containing even moderate levels of moisture. Chemically, alkyds are synthetic resins formed by the condensation of polyhydric alcohols with polybasic acids. They may be regarded as complex esters. The most common polyhydric alcohol used is glycerol, and the most common polybasic acid is phthalic anhydride. Modified alkyds are those in which the polybasic acid is substituted in part by a monobasic acid, of which the vegetable oil fatty acids are typical.
Oil based coatings used in a wide variety of protective coatings, such as floor and deck paint enamels, wall and trim paints, stains, and varnishes.
This plastic was developed in 1926 and was promptly put to work in liquid form as enamels, paints, lacquers, and similar coatings for automotibles, refrigerators, stoves and similar products--still the largest use for alkyds. In 1948, however, an alkyd compound was introduced as a molding material for compression molding electrical applications like circuit breaker insulation, coal forms, capacitor and resistor encapsulation, cases, housings, and switchgear components. Major properties are in the electrical area where alkyd molding materials offer excellent dielectric strength. Alkyds also have excellent heat resistance and are dimensionally stable under high temperatures. Alkds are thermosetting unsaturated polyester resins produced by reacting an organic alcohol with an organic acid, dissolved in and reacted with unsaturated monomers such as styrene [C6H5CHCH2], diallyl phthalate [C6H4(COOCH2CHCH2)2], diacetone acrylamide [CH3COCH2C(CH3)2CHCHCONH2] or vinyl toluene [CH2CHC6H4CH2]. Typical applications are electrical uses, automotive parts, and as coatings.