| 摘要 |
<p>The invention relates to heat-curable, epoxy-free powder coating systems for preparing mat coatings comprising a dry blend of at least two powder coatings, each comprising a binder resin including a carboxyl-terminated polyester resin having an acid value from 20 to 200 mg KOH/g, a glass transition temperature of at least 40.degree.C; a .beta.-hydroxyalkylamide with at least two .beta.-hydroxyalkylamide groups per molecule; and optionally further additives. The binder resins differ in functionality, or, in other words, in the number of carboxyl and/or .beta.-hydroxyalkylamide groups per molecule. The invention also relates to a process for preparing the powder coating system and to the use thereof. The so-obtained epoxy-free, heat-curable powder coating system can be made by separate melt-extrusion of all its components. This powder coating system is toxicologically unobjectionable and can be used to produce weather-resistant protective coatings with mat surfaces.</p> |
