Pre-conversion coating composition

Abstract

The present invention is directed to a coating composition comprising (i) a corrosion inhibitor and the (ii) reaction product of a calcium compound with an acid compound. The coating composition is deposited onto a substrate prior to the application of a pre-treatment coating composition (conversion coating) onto the substrate. The present invention is also directed to a substrate that comprises a coating system that comprises such a coating composition.

1 . A coating composition comprising: (i) a corrosion inhibitor and (ii) calcium phosphate. 
     
     
         2 . The coating composition according to  claim 1 , wherein the corrosion inhibitor comprises organic-modified zinc aluminum molybedenum phosphate hydrate, zinc, aluminum, magnesium, molybdenum phosphate, 5-nitroisophthalate, yttrium, bismuth, lead, or combinations thereof. 
     
     
         3 . A coating composition comprising: (i) a corrosion inhibitor and the (ii) reaction product of a calcium compound with an acid compound. 
     
     
         4 . The coating composition according to  claim 3 , wherein the corrosion inhibitor comprises zinc, aluminum, magnesium, molybdenum phosphate, 5-nitroisophthalate, yttrium, bismuth, lead, or combinations thereof. 
     
     
         5 . The coating composition according to  claim 3 , wherein the calcium compound comprises calcium nitrate, calcium phosphate, or combinations thereof. 
     
     
         6 . The coating composition according to  claim 3 , wherein the acid compound comprises phosphoric acid, fluorotitanic acid, fluorosilicic acid, or combinations thereof, or combinations thereof. 
     
     
         7 . The coating composition according to  claim 3 , wherein the coating composition does not contain fluorotitanic acid. 
     
     
         8 . A method of coating a substrate comprising:
 (a) applying a first coating composition onto at least a portion of the substrate wherein said first coating composition comprises: (i) a corrosion inhibitor and (ii) the reaction product of a calcium compound with an acid compound;   (b) dehydrating at least a portion of the first coating composition to form a first coating layer;   (c) removing at least a portion of the first coating layer to expose a portion of the substrate;   (d) optionally, rinsing at least a portion of the substrate exposed in step (c) and/or the first coating layer; and   (e) applying a second coating composition onto at least a portion of the exposed substrate or at least a portion of the first coating layer.   
     
     
         9 . The method of  claim 8 , wherein the calcium compound comprises calcium nitrate, calcium phosphate, or combinations thereof. 
     
     
         10 . The method of  claim 8 , wherein the acid compound comprises phosphoric acid, fluorotitanic acid, fluorosilicic acid, or combinations thereof. 
     
     
         11 . The method of  claim 8 , wherein the first coating composition does not contain fluorotitanic acid. 
     
     
         12 . The method of  claim 8 , wherein the second coating comprises a pretreatment coating composition. 
     
     
         13 . The method of  claim 8 , wherein the second coating comprises an electrodepositable coating composition or a primer-surfacer coating composition. 
     
     
         14 . The method of  claim 8 , wherein the (i) corrosion inhibitor comprises zinc, aluminum, magnesium, molybdenum phosphate, 5-nitroisophthalate, yttrium, bismuth, lead, or combinations thereof. 
     
     
         15 . A method of coating a substrate comprising:
 (a) applying a first coating composition onto at least a portion of the substrate wherein said first coating composition comprises: (i) a corrosion inhibitor and (ii) the reaction product of a calcium compound with an acid compound;   (b) dehydrating at least a portion of the first coating composition thereby forming a first coating layer;   (c) optionally, rinsing the substrate; and   (d) applying a second coating composition onto at least a portion of the first coating layer.   
     
     
         16 . The method of  claim 15 , wherein the calcium compound comprises calcium nitrate, calcium phosphate, or combinations thereof. 
     
     
         17 . The method of  claim 15 , wherein the acid compound comprises phosphoric acid, fluorotitanic acid, fluorosilicic acid, or combinations thereof. 
     
     
         18 . The method of  claim 15 , wherein the first coating composition does not contain fluorotitanic acid. 
     
     
         19 . The method of  claim 15 , wherein the second coating composition comprises a pre-treatment coating composition, an electrodepositable coating composition, or a primer-surfacer coating composition. 
     
     
         20 . The method of  claim 15 , wherein the (i) corrosion inhibitor comprises zinc, aluminum, magnesium, molybdenum phosphate, 5-nitroisophthalate, yttrium, bismuth, lead, or combinations thereof. 
     
     
         21 . A substrate comprising a coating system deposited on at least a portion of a substrate, said coating system comprising:
 a first layer, the first layer comprising the coating composition of  claim 1 ; and   a second layer deposited on at least a portion of the first layer.   
     
     
         22 . A substrate comprising a coating system deposited on at least a portion of a surface of the substrate, said coating system comprising:
 a first layer, the first layer comprising the coating composition of  claim 3 ; and   a second layer deposited on at least a portion of the first layer.