Coated substrates and methods of preparing the same

Abstract

The present invention relates to a substrate having (a) a first material applied to at least a portion of the substrate, and (b) a coating layer deposited from a powder coating composition including a film-forming resin, and optionally a crosslinker that is reactive with the film-forming resin, in direct contact with at least a portion of the substrate to which the first material has been applied. The first material is (i) a catalyst that catalyzes cure of the powder coating composition, (ii) a component reactive with the film-forming resin and/or the crosslinker of the powder coating composition, and/or (iii) a rheology modifier.

The invention claimed is: 
     
         1 . A substrate comprising
 a. a first material applied to at least a portion of the substrate; and   b. a coating layer deposited from a powder coating composition comprising a film-forming resin, and optionally a crosslinker that is reactive with the film-forming resin, in direct contact with at least a portion of the substrate to which the first material has been applied,
 wherein the first material is (i) a catalyst that catalyzes cure of the powder coating composition, (ii) a component reactive with the film-forming resin and/or the crosslinker of the powder coating composition, and/or (iii) a rheology modifier. 
   
     
     
         2 . The substrate of  claim 1 , wherein the interfacial flow of the liquidized powder coating composition in contact with at least a portion of the substrate to which the first material has been applied is lower than the interfacial flow of the same powder composition liquidized under the same conditions that is in contact with an identical substrate with the exception that no first material has been applied or with a portion of the same substrate to which the first material has not been applied. 
     
     
         3 . The substrate of  claim 1 , wherein the viscosity of the liquidized powder coating composition upon and/or after contact with the first material is higher than the viscosity of the same powder coating composition liquidized under the same conditions without contact to the first material. 
     
     
         4 . The substrate of  claim 1 , wherein the first material is localized at the interface where the powder coating composition comes into contact with the first material. 
     
     
         5 . The substrate of  claim 1 , wherein the first material migrates into at least a portion of the powder coating composition. 
     
     
         6 . The substrate of  claim 1 , wherein the first material is the catalyst that catalyzes cure of the powder coating composition. 
     
     
         7 . The substrate of  claim 1 , wherein the first material is the component reactive with the film-forming resin and/or the crosslinker of the powder coating composition. 
     
     
         8 . The substrate of  claim 7 , wherein the first material comprises a crosslinker, a resin, a reactive diluent, a monomer, or a combination thereof that is reactive with the film-forming resin and/or the crosslinker of the powder coating composition. 
     
     
         9 . The substrate of  claim 1 , wherein the first material is the rheology modifier. 
     
     
         10 . The substrate of  claim 9 , wherein the rheology modifier comprises silica, chemically modified silica, alumina, chemically modified alumina, a hydrophobically modified ethylene-oxide polymer, or any combination thereof. 
     
     
         11 . The substrate of  claim 1 , wherein the first material prior to application is dispersed or dissolved in a liquid medium. 
     
     
         12 . The substrate of  claim 11 , wherein the liquid medium is an aqueous liquid medium. 
     
     
         13 . The substrate of  claim 1 , wherein the first material is applied directly over at least a portion of the substrate. 
     
     
         14 . The substrate of  claim 1 , wherein the first material is included in a pretreatment composition applied to at least a portion of the substrate. 
     
     
         15 . The substrate of  claim 14 , wherein there is a greater concentration of the first material in a surface region of the pretreatment composition applied to at least a portion of the substrate than a bulk region of the pretreatment composition applied to at least a portion of the substrate. 
     
     
         16 . The substrate of  claim 1 , wherein the substrate further comprises a pretreatment layer and the first material is applied over at a least portion of the pretreatment layer. 
     
     
         17 . The substrate of  claim 1 , wherein the substrate further comprises a coating layer and the first material is applied over at a least portion of the coating layer. 
     
     
         18 . The substrate of  claim 1 , wherein after application to the substrate, at least a portion of the powder coating composition has a pill flow rate of greater than 30 mm as measured by the pill flow test. 
     
     
         19 . The substrate of  claim 1 , wherein the powder coating composition is physisorbed onto the substrate. 
     
     
         20 . The substrate of  claim 1 , wherein the first material is physisorbed on the substrate. 
     
     
         21 . The substrate of  claim 1 , wherein the first material is chemisorbed on the substrate. 
     
     
         22 . The substrate of  claim 1 , further comprising a second coating composition applied over at least a portion of a coating formed from the powder coating composition of (b). 
     
     
         23 . The substrate of  claim 1 , wherein the substrate comprises cold rolled steel, hot rolled steel, steel coated with zinc metal, zinc compounds, zinc alloys, electrogalvanized steel, hot-dipped galvanized steel, galvanealed steel, steel plated with zinc alloy, stainless steel, zinc-aluminum-magnesium alloy coated steel, aluminum, aluminum alloys, aluminum plated steel, aluminum alloy plated steel, magnesium, magnesium alloys, nickel, brass, copper, silver, gold, plastic, or any combination thereof. 
     
     
         24 . The substrate of  claim 1 , wherein the substrate is a fastener, coiled metal, a vehicle, a package, a heat exchanger, a vent, an extrusion, roofing, flooring, a wheel, a grate, a belt, a conveyor, an aircraft, an aircraft component, a vessel, a marine component, a vehicle, a building, an electrical component, a grain or seed silo, wire mesh, a screen or grid, HVAC equipment, a frame, a tank, a cord, a wire, or any combination thereof. 
     
     
         25 . The substrate of  claim 1 , wherein the coating layer formed from the powder coating composition applied over the substrate to which the first material has been applied has an R-value of 75% or greater as compared to an R-value of a coating layer formed from the powder coating composition applied over a substrate that is free of the first material, where R-value is measured by the R-value test. 
     
     
         26 . The substrate of  claim 1 , wherein the dry film thickness of the coating layer formed from the powder coating composition at the edge of the substrate is 2 μm or greater. 
     
     
         27 . The substrate of  claim 1 , wherein a ratio of the dry film thickness of the coating layer formed from the powder coating composition at the edge and at 10 mm away from the edge into the center is from 1:3 to 1:15. 
     
     
         28 . The substrate of  claim 1 , wherein the coated substrate has 10% or less linear edge corrosion after 40 cycles as measured by the linear edge corrosion test. 
     
     
         29 . A method for treating a substrate, sealing at least a portion of a surface of a substrate, decreasing sag resistance of a coating on a substrate, improving adhesion of a coating to a substrate, and/or improving edge coverage of a coating on a substrate comprising:
 a. contacting at least a portion of the substrate with a first material;   b. directly contacting at least a portion of the substrate in contact with the first material with a powder coating composition comprising a film forming resin and optionally a crosslinker that is reactive with the film forming resin; and   c. liquidizing the powder coating composition to form a coating layer of the powder coating composition on the substrate,
 wherein the first material is (i) a catalyst that catalyzes cure of the powder coating composition, (ii) a component reactive with a film-forming resin and/or a crosslinker of the powder coating composition, and/or (iii) a rheology modifier. 
   
     
     
         30 . The method of  claim 29 , wherein the interfacial flow of the liquidized powder coating composition in contact with at least a portion of the substrate to which the first material has been applied is lower than the interfacial flow of the same powder composition liquidized under the same conditions that is in contact with an identical substrate with the exception that no first material has been applied or with a portion of the same substrate to which the first material has not been applied. 
     
     
         31 . The method of  claim 29 , wherein the viscosity of the liquidized powder coating composition upon and/or after contact with the first material is higher than the viscosity of the same powder coating composition liquidized under the same conditions without contact to the first material. 
     
     
         32 . The method of  claim 29 , wherein step (a) comprises dipping the substrate in a bath that comprises the first material. 
     
     
         33 . The method of  claim 32 , wherein the bath comprises a pretreatment bath. 
     
     
         34 . The method of  claim 33 , wherein the pretreatment bath is a cleaner bath, a deoxidizer bath, a cleaner-coater bath, a rinse conditioner bath, a pretreatment coating bath, a rinsing bath, a sealing bath, or a deionized water rinsing bath. 
     
     
         35 . The method of  claim 29 , wherein the first material is contained on and/or in a wipe and step (a) comprises wiping the substrate. 
     
     
         36 . The method of  claim 29 , wherein the first material is contained in a liquid formulation and the liquid formulation is sprayed onto the substrate in step (a). 
     
     
         37 . The method of  claim 36 , wherein the liquid formulation further comprises a surfactant. 
     
     
         38 . The method of  claim 29 , wherein the first material is deposited onto the substrate by electrodeposition or vapor deposition in step (a). 
     
     
         39 . The method of  claim 29 , wherein the first material is bushed or rolled onto the substrate in step (a). 
     
     
         40 . The method of  claim 29 , wherein the first material is a solid and is blasted onto the substrate in step (a). 
     
     
         41 . The method of  claim 29 , wherein the substrate is cleaned and coated with the first material in a single step. 
     
     
         42 . The method of  claim 29 , wherein the substrate is plated with a metal prior to step (a). 
     
     
         43 . The method of  claim 29 , wherein the substrate comprises an anodized, cast, or forged metal. 
     
     
         44 . The method of  claim 29 , wherein the substrate is treated prior to step (a). 
     
     
         45 . The method of  claim 44 , wherein, prior to step (a), the substrate is alkaline cleaned, deoxidized, mechanically cleaned, ultrasonically cleaned, plasma cleaned or etched, exposed to chemical vapor deposition, treated with an adhesion promoter, or any combination thereof. 
     
     
         46 . The method of  claim 29 , wherein the substrate is pretreated prior to step (a) with a pretreatment composition. 
     
     
         47 . The method of  claim 46 , wherein the pretreatment composition comprises a sol-gel, iron phosphate, manganese phosphate, zinc phosphate, a rare earth metal, permanganate, zirconium, titanium, a silane, trivalent chrome (TCP), chromate, a silicate, silica, molybdenum, a lanthanide, metal chelates, metal oxide, hydrotalcite, phosphonic acid, layered double hydroxide, or any combination thereof. 
     
     
         48 . The method of  claim 46 , wherein, after pretreatment, the substrate is rinsed with, sprayed with, or wiped with a solution that comprises the first material in step (a). 
     
     
         49 . The method of  claim 46 , wherein the pretreatment composition is dried after application. 
     
     
         50 . The method of  claim 29 , further comprising step (d), contacting at least a portion of the substrate with a second coating composition. 
     
     
         51 . The method of  claim 29 , wherein the first material is dried by air and/or heat after step (a). 
     
     
         52 . The method of  claim 29 , wherein there is no intervening step between step (a) and step (b). 
     
     
         53 . The method of  claim 29 , wherein first material is applied directly to the substrate. 
     
     
         54 . The method of  claim 29 , wherein the powder coating composition, upon cure, has an R-value of 75% or greater as compared to an R-value of a coating formed from the powder coating composition applied over a substrate that is free of the first material, where R-value is measured by the R-value test. 
     
     
         55 . The method of  claim 29 , wherein the dry film thickness of the coating formed from the powder coating composition at the edge of the substrate is 2 μm or greater. 
     
     
         56 . The method of  claim 29 , wherein a ratio of the dry film thickness of the coating formed from the powder coating composition at the edge and at 10 mm away from the edge into the center is from 1:3 to 1:15. 
     
     
         57 . The method of  claim 29 , wherein the coated substrate has 10% or less linear edge corrosion after 40 cycles as measured by the linear edge corrosion test. 
     
     
         58 . A method for treating a coil comprising
 a. contacting at least a portion of the coil with a first material;   b. rolling the coil;   c. unrolling the coil;   d. directly contacting at least a portion of the coil in contact with the first material with a powder coating composition comprising a film forming resin and optionally a crosslinker that is reactive with the film forming resin; and   e. liquidizing the powder coating composition to form a coating layer of the powder coating composition on the coil,
 wherein the first material is (i) a catalyst that catalyzes cure of the powder coating composition, (ii) a component reactive with the film-forming resin and/or the crosslinker of the powder coating composition, and/or (iii) a rheology modifier.