Alkyd resins modified with cyclic fatty acids a preliminary evaluation

Alkyd resins were modified to 50% oil length with crude, flash-distilled, and 78% pure cyclic fatty acids. These resins were compared with ones modified with naturally occurring fatty acids and with vegetable oils. Those modified with the cyclic acids process more rapidly than those prepared with linseed, safflower, or soybean fatty acids, and they also have good nonyellowing properties. Resins modified with 78% pure cyclic acids show definite improvement in drying time, hardness, and chemical resistance in air-dried films, and an almost equal improvement in baked films, over resins obtained with the other modifiers. Distilled cyclic acids also improve alkyd resins although not to the extent that pure acids do. Both give resins superior to commercial oil-modified resins under the test conditions. Resins with crude cyclic acids are as good in air-dried films as are the others, but are poorer in baked films.