The drying and curing of alkyd resin coatings is an oxidative polymerization type, which is completely different from the physical volatilization of chlorinated rubber or the curing of epoxy resin curing agents. In addition to alkyd resin coatings, this type of drying and curing mechanism coatings also includes natural resin coatings that use natural oils as film-formers or contain oil components, and phenolic resin coatings and epoxy coatings that are synthesized from oils. The molecular weight of the unsaturated fatty acids in these coatings is increased by oxidation, and the oxidative polymerization rate is related to the number, position and oxygen transfer rate of the methylene groups contained in it.
To speed up the oxidative drying process, driers can be used. In most cases, the oxygen head is specialized to attack the C=C bond, or the methylene group at the a-position. The use of metal salt driers, such as octoate, naphthenate, linoleate, etc. of cobalt, manganese, calcium, zinc, aluminum and lead, will facilitate the attack of oxygen. Because multivalent metal salts can be oxygen carriers, or combine with double bonds to form new compounds that are more easily attacked by oxygen.
