Method for determining gloss in polyester/beta-hydroxyalkylamide powder coatings

摘要

A method for determining gloss in a curative powder coatings containing at least two polyester resins and beta-Hydroxyalkylamide formulations. The method includes the steps of: providing a powder coating comprising a first polyester resin and beta-hydroxyalkylamide formulation having a first acid value and a second polyester resin and beta-hydroxyalkylamide formulation having a second acid value; blending the first and second formulations together to make coating; determining the percent difference in the acid values between the first and second polyester resins; determining a surface gloss of the coating after application; determining a gloss versus percent difference in acid values correlation; and determining the amount of at least one of the resins to be present in the blend to achieve the desired gloss using the correlation. A multi-component powder coating having a substantially predetermined gloss when applied to a substrate. The coating includes at least two polyester resin and beta-hydroxyalkylamide formulations blended together wherein each polyester resin has a different acid value. The amount of each formulation in the coating is determined in accordance with the above method to achieve the desired gloss.