Abstract: Disclosed is an aqueous dispersion of a transparent powder coating consisting of a solid powder component and an aqueous component. The solid powder component includes at least one epoxy group-containing binder, at least one crosslinking agent, and optionally catalysts, adjuvants, or additives typical for transparent powder coatings. The binder contains 30-45% glycidyl-containing monomers and optionally vinylaromatic compounds such as styrene. The crosslinking agent is preferably a straight-chain aliphatic dicarboxylic acid and/or a carboxy-functional polyester. The aqueous component includes at least one nonionic thickener and optional materials such as catalysts, adjuvants, and/or other such materials. The nonionic thickener is preferably a nonionic associative thickener. The invention also provides a process for preparing the aqueous dispersion of the invention and a process for coating a vehicle body with the aqueous dispersion of the invention.

Abstract: The present invention relates to a process for the production of a powder coating, in which a suspension of powder particles is sprayed and the spray jet is directed onto the substrate to be coated, characterized in that1.) a suspension of powder particles in a liquefied gas is employed, the gas having been liquefied under a pressure of not more than 20 bar, and2.) the liquid gas is vaporized before, during or after the spraying of the suspension.

Abstract: The present invention relates to an aqueous powder coating dispersion based on epoxy resins and phenolic curing agents or carboxyl-containing polyesters for the coating of packaging containers, which dispersion consists of a solid, pulverulent component I and an aqueous component II, component I being a powder coating which containsA) at least one epoxy resin having an epoxide equivalent weight of from 300 to 5500 andB) at least one curing agent having more than one phenolic hydroxyl group per molecule and a hydroxyl equivalent weight, based on phenolic OH groups, of from 100 to 500, preferably from 200 to 300, orC) at least one polyester having an acid number of from 25 to 120 mg of KOH/g and an OH number >10 mg of KOH/g, andD) at least one epoxy resin having an epoxide equivalent weight of from 400 to 3000, and component II being the aqueous component of the dispersion which contains at least one nonionic or anionic thickener.

Abstract: The invention relates to powder coatings which are characterized in that they contain as film-forming material a mixture of(A) from 19.9 to 90.0 percent by weight of a synthetic resin which contains epoxide groups and may contain ethylenically unsaturated double bonds, or of a mixture of such epoxide group-containing synthetic resins,(B) from 9.9 to 80.0 percent by weight of a compound which contains carboxyl groups and may contain ethylenically unsaturated double bonds, or of a mixture of such carboxyl group-containing compounds,(C) from 0 to 20 percent by weight of a compound which contains ethylenically unsaturated double bonds and is different from (A) and (B), or of a mixture of such compounds, and(D) from 0.1 to 3.0 percent by weight of an initiator for free-radical polymerizations or of a mixture of initiators for free-radical polymerizations,the percentages by weight of (A)+(B)+(C)+(D) being=200% by weight and the mixture of components (A), (B), (C) and (D) containing from 0.1 to 6.

Abstract: The invention relates to a process for the production of two-coat finishes, in which a pigmented basecoat is first applied, the resulting basecoat film is coated with a powder clearcoat, and basecoat and clearcoat are subsequently baked together. In accordance with the invention, the powder clearcoat employed is a powder coating which contains an epoxide group-containing polyacrylate resin as binder and a mixture of (A) a polyanhydride and (B) a carboxyl group-containing polyester resin as crosslinking agent. The polyester resin can be prepared by reacting a diol (b1), a compound (b2) which contains per molecule at least three functional groups selected from hydroxyl, primary amino, secondary amino, carboxyl and acid anhydride groups, and (b3) a dicarboxylic acid in a molar ratio of (b1): (b2): (b3)=0.0 to 3.0: 1.0: 1.5 to 9.0 to give a polyester resin having an acid value of 40 to 300.

Abstract: The invention relates to a process for the preparation of powder coatings, in which a mixture ofA) a binder comprising an epoxide group-containing synthetic resin or a mixture of epoxide group-containing synthetic resins, andB) a crosslinking agent comprising a compound which contains on statistical average at least two carboxyl groups and at least one acid anhydride group per molecule, or a mixture of such compounds, is admixed before or during the melt homogenization process withC) a polyol or a mixture of polyols in such an amount that from 0.1 to 0.9 hydroxyl groups of component C) are present per acid anhydride group of component B).The mixture is homogenized in the molten state and the resulting homogenized melt, after having cooled and solidified, is powdered.