Abstract: A method of providing a powder coating to MDF substrate panels wherein, by the differential treatment of the front and back surfaces of these panels, both surfaces can be coated at the same time and the effects of moisture and other volatile outgassing is controlled in such a way as to provide a blemish-free front facing surface with a minimal, but nonetheless acceptable, amount of blemishes on the opposite or back surface. Differential treatment is achieved by preparing each surface using different grades of sand-paper, applying different amounts of curing energy, whether infra-red or thermal, or by applying different thicknesses of coating to each surface.

Abstract: Coating powders with enhanced electrostatic attraction to low conductivity substrates such as engineered wood are disclosed. The addition of conductive fillers to low temperature cure coating powder compositions improves the coating of difficult to coat substrates such as raised panel cabinet doors. Low temperature cure coating powders containing conductive additives can be applied to preheated engineered wood substrates. Also disclosed are methods for forming a powder coating on a low conductivity substrate.

Abstract: Coating powders with enhanced electrostatic attraction to low conductivity substrates such as engineered wood are disclosed. The addition of conductive fillers to low temperature cure coating powder compositions improves the coating of difficult to coat substrates such as raised panel cabinet doors. Low temperature cure coating powders containing conductive additives can be applied to preheated engineered wood substrates. Also disclosed are methods for forming a powder coating on a low conductivity substrate.

Abstract: Heat sensitive substrates, as well as others such as metal or glass, are electrostatically coated with a thermosetting coating powder comprising a melt-mixed, chilled, chipped, and powdered blend of an epoxy resin and a catalyst therefore, and a powdered low temperature curing agent along with conventional additives. The coating powder is deposited on the substrate and heated to fuse, flow and cure. The mixture of resin and catalyst does not cure within the extruder but it is made to cure at low temperatures on the desired substrate by the separate addition of the curing agent to the powdered melt-mixed blend. A small amount of the low temperature curing agent, insufficient to cause substantial curing in the molten stage may be used in place of the catalyst.

Abstract: A method of providing a powder coating to MDF substrate panels wherein, by the differential treatment of the front and back surfaces of these panels, both surfaces can be coated at the same time and the effects of moisture and other volatile outgassing is controlled in such a way as to provide a blemish-free front facing surface with a minimal, but nonetheless acceptable, amount of blemishes on the opposite or back surface. Differential treatment is achieved by preparing each surface using different grades of sand-paper, applying different amounts of curing energy, whether infra-red or thermal, or by applying different thicknesses of coating to each surface.

Abstract: A coating powder, based on glycidyl (meth)acrylate copolymer/carboxylic acid functional polyester chemistry, provides a smooth, weatherable, reduced gloss coating for use on heat sensitive substrates, such as wood. The glycidyl (meth)acrylate copolymer has an epoxy equivalent weight of 250 to 400 and the carboxylic acid functional polyester has a viscosity of 2500 cps or less at 200 C.

Abstract: Wood is electrostatically coated with a thermosetting powder coating system in which a mixture of a self-curing epoxy resin and a catalyst therefore is extruded and a low temperature curing agent are both pulverized and the powders are blended with conventional additives to make a coating powder which is deposited on a wooden substrate and heated to cure. The mixture of resin and catalyst does not cure within the extruder but it is made to cure at low temperatures by the separate addition of the curing agent. A small amount of the low temperature curing agent, insufficient to cause substantial curing during extrusion may be used in place of the catalyst.

Abstract: Low temperature curable unsaturated polyester powder coatings suited for heat sensitive substrates with improved surface cure through incorporation of active hydrogen groups into the unsaturated polyester molecule. The unsaturated polyesters containing active hydrogens are derived from ethylenically unsaturated polyfunctional carboxylic acids and active hydrogen containing polyols. Full cure on the surface is obtained without the need for polyethylene waxes or oxygen-reactive curative resins that are commonly employed in order to prevent atmospheric oxygen from inhibiting the free-radical induced cure at the surface of the coating.

Abstract: Opaquely pigmented or thick filmed powder coatings for heat sensitive substrates, such as wood, wood composites, for example, medium density fiber board, and plastics, that can be fully cured, especially near the substrate, through the incorporation of a dual cure system in the powder comprising a thermal initiator, such as a peroxide, along with a UV initiator. The UV initiator cures the surface, while the thermal initiator cures at the substrate. Surprisingly, virtually no pregelation occurs during the heated melt and flow out step prior to UV curing. Consequently, the hardened film finish formed on the surface exhibits exceptional smoothness which is comparable to that of traditional UV curable powders. The hardened film finish is also fully cured throughout and exhibits exceptional adhesion to the substrate which cannot be achieved with traditional UV curable powders that have been pigmented.

Abstract: Opaquely pigmented or thick filmed powder coatings for heat sensitive substrates, such as wood, wood composites, for example, medium density fiber board, and plastics, that can be fully cured, especially near the substrate, through the incorporation of a dual cure system in the powder comprising a thermal initiator, such as a peroxide, along with a UV initiator. The UV initiator cures the surface, while the thermal initiator cures at the substrate. Surprisingly, virtually no pregelation occurs during the heated melt and flow out step prior to UV curing. Consequently, the hardened film finish formed on the surface exhibits exceptional smoothness which is comparable to that of traditional UV curable powders. The hardened film finish is also fully cured throughout and exhibits exceptional adhesion to the substrate which cannot be achieved with traditional UV curable powders that have been pigmented.

Abstract: Opaquely pigmented or thick filmed powder coatings for heat sensitive substrates, such as wood, wood composites, for example, medium density fiber board, and plastics, that can be fully cured, especially near the substrate, through the incorporation of a dual cure system in the powder comprising a thermal initiator, such as a peroxide, along with a UV initiator. The UV initiator cures the surface, while the thermal initiator cures at the substrate. Surprisingly, virtually no pregelation occurs during the heated melt and flow out step prior to UV curing. Consequently, the hardened film finish formed on the surface exhibits exceptional smoothness which is comparable to that of traditional UV curable powders. The hardened film finish is also fully cured throughout and exhibits exceptional adhesion to the substrate which cannot be achieved with traditional UV curable powders that have been pigmented.

Abstract: Wood is electrostatically coated with a thermosetting powder coating system in which a mixture of a self-curing epoxy resin and a catalyst therefore is extruded and a low temperature curing agent are both pulverized and the powders are blended with conventional additives to make a coating powder which is deposited on a wooden substrate and heated to cure. The mixture of resin and catalyst does not cure within the extruder but it is made to cure at low temperatures by the separate addition of the curing agent. A small amount of the low temperature curing agent, insufficient to cause substantial curing during extrusion may be used in place of the catalyst.

Abstract: Thermosetting powder coating compositions adapted to form a grainy textured finish on heat sensitive substrates, especially wood products, such as particle board, conductive particle board, and medium density fiber board, without damaging the substrates comprise an epoxy resin, particularly bisphenol A type epoxy resins having low viscosities, either a catalytic curing agent comprising an imidazole, a substituted imidazole, or adduct of an imidazole or substituted imidazole and an epoxy resin, or a curing agent comprising an adduct of a polyamine and an epoxy resin, or a combination of the catalytic curing agent and curing agent, a texturing agent, a flow control agent, optional extender, and optional pigment. The thermosetting powder coatings have a cure time/temperature ranging from about 30 seconds at about 350.degree. F. peak substrate temperature down to about 20 minutes at about 225.degree. F.

Abstract: Wood is electrostatically coated with a thermosetting powder coating system in which a mixture of a self-curing epoxy resin and a catalyst therefore is extruded and a low temperature curing agent are both pulverized and the powders are blended with conventional additives to make a coating powder which is deposited on a wooden substrate and heated to cure. The mixture of resin and catalyst does not cure within the extruder but it is made to cure at low temperatures by the separate addition of the curing agent. A small amount of the low temperature curing agent, insufficient to cause substantial curing during extrusion may be used in place of the catalyst.

Abstract: .[.Wood.]. .Iadd.A heat sensitive substrate .Iaddend.is .[.electrostatically.]. coated with a thermosetting powder coating system in which a mixture of a self-curing epoxy resin and a catalyst therefore is extruded and .Iadd.pulverized and .Iaddend.a low temperature curing agent .[.are both.]. .Iadd.a .Iaddend.pulverized and the powders are blended with conventional additives to make a coating powder which is deposited on .[.a wooden.]. .Iadd.the .Iaddend.substrate and heated to cure. The mixture of resin and catalyst does not cure within the extruder but it is made to cure at low temperatures by the separate addition of the curing agent. A small amount of the low temperature curing agent, insufficient to cause substantial curing during extrusion may be used in place of the catalyst.