Satd alkyd resins modified by monoepoxides - useful as powder coating resins

摘要

Alkyd resins are made by reacting an unmodified alkyd resin with an acid index of 10-50, and made by the reaction of =1 diol or polyol with =1 di- or poly carboxylic acid, and reacting the alkyd formed with a monoepoxide pref. monosubsd. ethylene oxide, in sufficient quantity to react with =10% or the original amt of carboxylic acid, during which the acid index is lowered to 10. The unmodified and modified alkyds both have an OH index of 20-300. The unmodified alkyd may be made in two stages by reacting =1 diol or polyol with =1 di- or poly-carboxylic acid, and reacting the prod. with an alcohol, or carboxylic acid, or a prod. from these two. The modified product is ground and mixed with a cross-linking agent, and opt. a filler or pigment, and is applied by electrostatic pistol or flame gun, to give hard, adherent flexible coatings.