Activating rinse and method for treating a substrate

Abstract

Disclosed is an activating rinse for treating at least a portion of a substrate, comprising a dispersion of metal phosphate particles having a D 90 particle size of no greater than 10 μm, wherein the metal phosphate comprises divalent or trivalent metals or combinations thereof; a dispersant; and a metal sulfate salt. Methods of treating a substrate with the activating rinse also are disclosed. Optionally, substrates treated with the activating rinse also are disclosed.

We claim: 
     
         1 . An activating rinse for treating a substrate comprising:
 a dispersion of metal phosphate particles having a D 90  particle size of no greater than 10 μm, wherein the metal phosphate comprises divalent or trivalent metals or combinations thereof;   a dispersant; and   a metal sulfate salt.   
     
     
         2 . The activating rinse of  claim 1 , wherein the D 90  particle size is measured from a sample of the activating rinse that has been sonicated. 
     
     
         3 . The activating rinse of  claim 1 , wherein the dispersant comprises a non-ionic dispersant. 
     
     
         4 . The activating rinse of  claim 1 , wherein the activating rinse is substantially free of ionic dispersants. 
     
     
         5 . The activating rinse of  claim 1 , wherein a sulfate ion of the metal sulfate salt is present in an amount of 5 ppm to 5,000 ppm based on a total weight of the activating rinse. 
     
     
         6 . The activating rinse of  claim 1 , wherein the metal of the metal sulfate salt comprises a divalent metal. 
     
     
         7 . The activating rinse of  claim 6 , wherein the divalent metal comprises nickel, cobalt, zinc, iron, copper, or combinations thereof. 
     
     
         8 . The activating rinse of  claim 1 , wherein the metal phosphate particles have a D 90  particle size of no more than 1 μm. 
     
     
         9 . The activating rinse of  claim 1 , wherein the metal phosphate particles are substantially pulverized. 
     
     
         10 . The activating rinse of  claim 1 , wherein the activating rinse comprises a multi-component system, and wherein the dispersion of metal phosphate particles and the dispersant form a part of a first component and the metal sulfate salt form a part of a second component. 
     
     
         11 . A method for treating a substrate comprising contacting at least a portion of a surface of the substrate with the activating rinse of  claim 1 . 
     
     
         12 . The method of  claim 11 , further comprising contacting at least a portion of the surface of the substrate that has been contacted with the activating rinse with a metal phosphate pretreatment composition. 
     
     
         13 . The method of  claim 12 , wherein contacting the surface of the substrate with the metal phosphate pretreatment composition comprises immersing the substrate in a bath comprising the metal phosphate pretreatment composition, wherein the bath temperature is from 20° C. to 60° C. 
     
     
         14 . The method of  claim 12 , wherein contacting the surface of the substrate with the metal phosphate pretreatment composition comprises immersing the substrate in a bath comprising the metal phosphate pretreatment composition, wherein the bath temperature is 20° C. to 25° C. 
     
     
         15 . A substrate treated with the activating rinse of  claim 1 . 
     
     
         16 . The substrate of  claim 15  further comprising a phosphate coating. 
     
     
         17 . The substrate of  claim 16 , wherein the phosphate coating comprises phosphate crystals having a crystal size of 0.4 μm to 4 μm. 
     
     
         18 . The substrate of  claim 16 , wherein the phosphate coating comprises phosphate crystals having a crystal size of 0.9 μm to 2.7 μm. 
     
     
         19 . The substrate of  claim 15 , wherein the substrate is hot dipped galvanized steel. 
     
     
         20 . An activating rinse for treating a substrate comprising:
 a dispersion of substantially pulverized metal phosphate particles having a D 90  particle size of no greater than 1 μm, wherein the metal phosphate comprises divalent or trivalent metals or combinations thereof; and   a dispersant.   
     
     
         21 . The activating rinse of  claims 20 , wherein the D 90  particle size is measured from a sample of the activating rinse that has been sonicated. 
     
     
         22 . The activating rinse of  claim 20 , wherein the metal phosphate particles having a D 90  particle size of no greater than 0.75 μm. 
     
     
         23 . A method for treating a substrate comprising contacting at least a portion of a surface of the substrate with the activating rinse of  claim 20 . 
     
     
         24 . The method of  claim 23 , further comprising contacting at least a portion of the surface of the substrate that has been contacted with the activating rinse with a metal phosphate pretreatment composition. 
     
     
         25 . The method of  claim 23 , wherein contacting the surface of the substrate with the metal phosphate pretreatment composition comprises immersing the substrate in a bath comprising the metal phosphate pretreatment composition, wherein the bath temperature is 20° C. to 25° C. 
     
     
         26 . A substrate treated with the activating rinse of  claim 20 .