Method for applying chemical coatings

Abstract

A method of anti-fouling a metal structure disposed in water, the method comprising providing a clean surface on the metal structure, applying a tie coat to the surface, and applying a thermoplastic top coat to the tie coat.

1 . A method for applying a thermoplastic coating onto a surface, the method comprising: 
 (a) depositing a tie coat onto the surface, and    (b) depositing a coat of thermoplastic material onto said tie coat.    
     
     
         2 . A method for applying an anti-fouling coating onto a marine surface, the method comprising: 
 (a) heating an anti-fouling mixture at a temperature sufficient to maintain said mixture as a liquid,    (b) agitating said liquid sufficiently to maintain a homogeneous mixture, and    (c) applying said agitated liquid to the marine surface that has previously been coated with a tie coat.    
     
     
         3 . A method of anti-fouling a metal structure for disposal in water, the method comprising: 
 providing a clean surface on the metal structure;    applying a tie coat to the metal surface; and    applying a thermoplastic top coat to the tie coat.    
     
     
         4 . The method of  claim 1  wherein the tie coat is an epoxy that includes a curing agent and a resin.  
     
     
         5 . The method of  claim 4  wherein the curing agent comprises a polyamine.  
     
     
         6 . The method of  claim 4  wherein the resin comprises a bisphenol resin.  
     
     
         7 . The method of  claim 1  wherein the tie coat and top coat form a bond at the interface of the tie coat and outer coat.  
     
     
         8 . The method of  claim 7  wherein the bond is primarily hydrogen bonding.  
     
     
         9 . The method of  claim 1  wherein the tie coat forms a layer having a thickness less than 5 mils.  
     
     
         10 . The method of  claim 1  wherein the top coat is applied while the tie coat is curing.  
     
     
         11 . The method of  claim 1  wherein the top coat includes copper and wax.  
     
     
         12 . The method of  claim 1  wherein the top coat is the composition described in U.S. Pat. No. 2,602,752.  
     
     
         13 . The method of  claim 1  wherein the top coat is substantially 100% solids at ambient temperature.  
     
     
         14 . The method of  claim 13  wherein the top coat allows the metal compounds to have an average leach rate less than or equal to about 10 μg/cm 2 /day.  
     
     
         15 . The method of  claim 1  wherein the top coat is a solid at ambient temperatures.  
     
     
         16 . The method of  claim 1  further including heating the top coat so as to be flowable.  
     
     
         17 . The method of  claim 1  further including heating the top coat to achieve the viscosity of a finishing material.  
     
     
         18 . The method of  claim 1  wherein the top coat is applied to the tie coat at a high temperature to enhance the reaction and/or interaction rate of the top coat with the tie coat at their interface.  
     
     
         19 . The method of  claim 1  wherein the top coat is heated to a temperature greater than 250° F. to achieve the viscosity of a finishing material.  
     
     
         20 . The method of  claim 1  wherein the top coat is applied to the tie coat at a higher temperature increasing the curing rate of the tie coat and causing the tie coat to increase the rate of hardening.  
     
     
         21 . The method of  claim 1  wherein the top coat has a total thickness of between 20 and 30 mils.  
     
     
         22 . The method of  claim 1  wherein the tie coat has a thickness of between 3 and 5 mils.  
     
     
         23 . The method of  claim 1  wherein the total thickness of the tie coat and top coat is in the range of 23 to 25 mils.  
     
     
         24 . The method of  claim 1  wherein the top coat is first heated in a thermoplastic stage from a solid to a flowable composition and then further heated in a finishing stage to the viscosity of a finishing material.  
     
     
         25 . The method of  claim 24  wherein the top coat is maintained within a pre-determined temperature range throughout the finishing stage.  
     
     
         26 . The method of  claim 24  wherein the top coat includes metal compounds which are maintained suspended within the top coat during the finishing stage.  
     
     
         27 . The method of  claim 1  wherein the top coat comprises greater than about 75% solids at ambient temperature.  
     
     
         28 . The method of  claim 1  wherein the top coat comprises less than or equal to 2% volatile organic compounds.