Method for treating and/or coating a substrate with non-chrome materials

Abstract

The present invention is directed to a method for coating a substrate comprising: (a) applying a caustic cleaner onto at least a portion of the substrate; (b) rinsing at least a portion of the substrate that was subjected to step (a) with water; (c) applying an acid cleaner onto at least a portion of the caustically cleaned substrate; (d) rinsing at least a portion of the substrate that was subjected to step (c) with water; and (e) applying a conversion coating comprising zirconium onto at least a portion of the acid cleaned substrate; and wherein at least one of the materials used in steps (c) and (e) is substantially chrome free. The present invention is also directed to a substrate, such as an aluminum substrate, that has been coated using the aforementioned method.

1 . A method for coating a substrate comprising: (a) applying a caustic cleaner onto at least a portion of the substrate; (b) rinsing at least a portion of the substrate that was subjected to step (a) with water; (c) applying an acid cleaner onto at least a portion of the caustically cleaned substrate; (d) rinsing at least a portion of the substrate that was subjected to step (c) with water; and (e) depositing a conversion coating composition comprising zirconium onto at least a portion of the acid cleaned substrate; and wherein at least one of the materials used in steps (c) and (e) is substantially chrome free. 
     
     
         2 . The method according to  claim 1 , wherein the method further comprises (f) rinsing at least a portion of the substrate that was subjected to step (e) with water; and (g) depositing an electrodepositable coating composition onto at least a portion of the conversion coating, wherein the electrodepositable coating composition comprises a corrosion inhibitor. 
     
     
         3 . The method according to  claim 2 , wherein the electrodepositable coating composition is substantially free of chrome. 
     
     
         4 . The method according to  claim 2 , wherein the corrosion inhibitor comprises an azole compound. 
     
     
         5 . The method according to  claim 4 , wherein the azole compound comprises benzotriazole, 3-mercapto-1,2,4-triazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4thiadiazole, 1-methylbenzotriazole, or combinations thereof. 
     
     
         6 . The method according to  claim 2 , wherein the electrodepositable coating composition comprises an ungelled phosphated epoxy resin in which the phosphated epoxy resin comprises a mixture of the reaction product of a polymeric epoxy compound with phosphoric acid, an organophosphonic acid, an organophosphinic acid, or combinations thereof. 
     
     
         7 . The method according to  claim 1 , wherein the acid cleaner comprises phosphoric acid, sulfonic acid, hydrofluoric acid, nitric acid, or combinations thereof. 
     
     
         8 . The method according to  claim 1 , wherein the conversion coating composition is substantially free of chrome. 
     
     
         9 . A method for coating a substrate comprising: (a) applying a caustic cleaner onto at least a portion of the substrate; (b) rinsing at least a portion of the substrate that was subjected to step (a) with water; (c) applying an acid cleaner onto at least a portion of the caustically cleaned substrate; (d) rinsing at least a portion of the substrate that was subjected to step (c) with water; and (e) depositing a conversion coating composition comprising zirconium onto at least a portion of the acid cleaned substrate; and wherein the materials used in steps (c) and (e) are substantially chrome free. 
     
     
         10 . The method according to  claim 9 , wherein the method further comprises (f) rinsing at least a portion of the substrate that was subjected to step (e) with water; and (g) depositing an electrodepositable coating composition onto at least a portion of the conversion coating composition, wherein the electrodepositable coating composition comprises a corrosion inhibitor. 
     
     
         11 . The method according to  claim 10 , wherein the corrosion inhibitor comprises an azole compound. 
     
     
         12 . The method according to  claim 11 , wherein the azole compound comprises benzotriazole, 3-mercapto-1,2,4-triazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4thiadiazole, 1-methylbenzotriazole, or combinations thereof. 
     
     
         13 . The method according to  claim 10 , wherein the electrodepositable coating composition comprises an ungelled phosphated epoxy resin in which the phosphated epoxy resin comprises a mixture of the reaction product of a polymeric epoxy compound with phosphoric acid, an organophosphonic acid, an organophosphinic acid, or combinations thereof. 
     
     
         14 . The method according to  claim 9 , wherein the materials used in steps (c) and (e) are substantially chrome free. 
     
     
         15 . A method for coating a substrate consisting essentially of: (a) applying a caustic cleaner onto at least a portion of the substrate; (b) rinsing at least a portion of the substrate that was subjected to step (a) with water; (c) applying an acid cleaner onto at least a portion of the caustically cleaned substrate; (d) rinsing at least a portion of the substrate that was subjected to step (c) with water; (e) depositing a conversion coating composition comprising zirconium onto at least a portion of the acid cleaned substrate; (f) rinsing at least a portion of the substrate that was subjected to step (e) with water; and (g) depositing an electrodepositable coating composition onto at least a portion of the conversion coating composition, wherein the electrodepositable coating composition comprises a corrosion inhibitor; and wherein the materials used in steps (c), (e), and (g) are substantially free of chrome. 
     
     
         16 . The method according to  claim 15 , wherein the corrosion inhibitor comprises an azole compound. 
     
     
         17 . The method according to  claim 16 , wherein the azole compound comprises benzotriazole, 3-mercapto-1,2,4-triazole, 2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4thiadiazole, 1-methylbenzotriazole, or combinations thereof. 
     
     
         18 . The method according to  claim 15 , wherein the electrodepositable coating composition comprises an ungelled phosphated epoxy resin in which the phosphated epoxy resin comprises a mixture of the reaction product of a polymeric epoxy compound with phosphoric acid, an organophosphonic acid, an organophosphinic acid, or combinations thereof. 
     
     
         19 . A substrate coated according to  claim 1 . 
     
     
         20 . The substrate according to  claim 19 , wherein the substrate is aluminum.