초록 ▼

Coating compositions are disclosed comprising a polyester comprising at least two reactive hydroxyl groups, a material comprising at least two functional groups reactive with the hydroxyl groups of the polyester, and a free acid. Methods of using the coatings, methods for refinishing an article with

Coating compositions are disclosed comprising a polyester comprising at least two reactive hydroxyl groups, a material comprising at least two functional groups reactive with the hydroxyl groups of the polyester, and a free acid. Methods of using the coatings, methods for refinishing an article with the coatings, and the substrates coated therewith, are also disclosed.

대표청구항 ▼

Therefore, we claim: 1. A method of coating a bare metal substrate comprising: (a) applying a composition comprising a coating composition directly to at least a portion of the bare metal, substrate; (b) coalescing the composition over the substrate in the form of a substantially continuous film; a

Therefore, we claim: 1. A method of coating a bare metal substrate comprising: (a) applying a composition comprising a coating composition directly to at least a portion of the bare metal, substrate; (b) coalescing the composition over the substrate in the form of a substantially continuous film; and (c) curing the composition; wherein the coating composition comprises: (a) a polyester comprising at least two reactive hydroxyl groups, wherein the polyester comprises the reaction product of reactants comprising: (i) a polycarboxylic acid comprising more than two acid groups per molecule, and (ii) polytetramethylene glycol having a hydroxyl number between 50 and 500 mg. KOH per gram; the molar ratio of (ii) to (i) being at least 2.5 to 1; (b) a material comprising at least two functional groups reactive with the hydroxyl groups of the polyester; and (c) 0.1 to 5 percent by weight based on total resin solids weight of a free acid. 2. The method of claim 1, wherein the coating composition further comprises a polymer different from the polyester the weight ratio of the polyester to the polymer being 60:40. 3. The method of claim 2, wherein the polymer comprises functional groups reactive with the functional groups of component (b). 4. The coating composition of claim 1, wherein the polycarboxylic acid comprises trimellitic acid, trimellitic anhydride, or a mixture thereof. 5. The method of claim 4, wherein the polycarboxylic acid comprises trimellitic anhydride. 6. The coating composition of claim 1, wherein the free acid (c) is selected from tannic acid, gallic acid, phosphoric acid, phosphorous acid, citric acid, malonic acid, a derivative thereof, or a mixture thereof. 7. A substrate at least partially coated in accordance with claim 1. 8. A method of refinishing a surface of an article comprising a bare metal substrate comprising: (a) removing a defect from the surface; (b) applying a first coating layer deposited from a coating composition directly to at least a portion of the surface of the bare metal substrate; and (c) applying a topcoat layer over at least a portion of the first coating layer (b); wherein the coating composition comprises: (a) a polyester comprising at least two reactive hydroxyl groups, wherein the polyester comprises the reaction product of reactants comprising: (i) a polycarboxylic acid comprising more than two acid groups per molecule, and (ii) polytetramethylene glycol having a hydroxyl number between 50 and 500 mg. KOH per gram; the molar ratio of (ii) to (i) being at least 2.5 to 1; (b) a material comprising at least two functional groups reactive with the hydroxyl groups of the polyester; and (c) 0.1 to 5 percent by weight based on total resin solids weight of a free acid. 9. The method of claim 8, wherein the article comprises an automobile part. 10. A method for improving chip resistance of a coated substrate comprising: (a) applying a composition comprising a coating composition directly to at least a portion of a bare metal substrate; (b) coalescing the composition over the substrate in the form of a substantially continuous film; and (c) curing the composition; wherein the coating composition comprises: (a) a polyester comprising at least two reactive hydroxyl groups, wherein the polyester comprises the reaction product of reactants comprising: (i) a polycarboxylic acid comprising more than two acid groups per molecule, and (ii) polytetramethylene glycol having a hydroxyl number between 50 and 500 mg. KOH per gram; the molar ratio of (ii) to (i) being at least 2.5 to 1; (b) a material comprising at least two functional groups reactive with the hydroxyl groups of the polyester; and (c) 0.1 to 5 percent by weight based on total resin solids weight of a free acid.