Coating compositions with anticorrosion properties

Abstract

Anticorrosive coating compositions comprise a binding polymer and an amorphous aluminum phosphate corrosion inhibiting pigment dispersed therein. The coating composition comprises 1 to 25 percent by weight aluminum phosphate. The binding polymer can include solvent-borne polymers, water-borne polymers, solventless polymers, and combinations thereof. The aluminum phosphate is made by combining an aluminum source with a phosphorous source to form an amorphous aluminum phosphate solid condensate. The coating composition is specially engineered to provide a controlled delivery of phosphate anions of 50 to 500 ppm, and has a total solubles content of less than 1500 ppm. The amorphous aluminum phosphate is preferably free of alkali metals and alkaline earth metals. The amorphous aluminum phosphate has an oil absorption of less than 50, and a surface area of less than about 20 m 2 /g, The coating composition has a water adsorption potential of up to 25% by weight water.

1 .- 63 . (canceled) 
     
     
         64 . A method of making aluminum phosphate comprising the steps of:
 combining starting materials comprising aluminum hydroxide with phosphoric acid in an aqueous system to form a mixture; and   reacting the mixture to form a reaction product of aluminum phosphate particles in aqueous media, wherein the aluminum phosphate particles comprise amorphous aluminum phosphate.   
     
     
         65 . The method as recited in  claim 64  wherein the starting materials consist of aluminum hydroxide and phosphoric acid. 
     
     
         66 . The method as recited in  claim 64  wherein the reaction product consists of aluminum phosphate. 
     
     
         67 . The method as recited in  claim 64  wherein prior to the step of combining, the aluminum hydroxide is combined with water. 
     
     
         68 . The method as recited in  claim 64  wherein the mixture formed during the step of combining is at room temperature. 
     
     
         69 . The method as recited in  claim 64  wherein during the step of combining, the phosphoric acid is added to the aluminum hydroxide. 
     
     
         70 . The method as recited in  claim 64  wherein during the step of combining, the aluminum hydroxide is added to the phosphoric acid. 
     
     
         71 . The method as recited in  claim 64  wherein the step of reacting is conducted at room temperature in the absence of added heat. 
     
     
         72 . The method as recited in  claim 64  wherein the reaction product is filtered and washed. 
     
     
         73 . The method as recited in  claim 64  further comprising drying the aluminum phosphate particles at a temperature less than about 200° C. 
     
     
         74 . The method as recited in  claim 64  wherein the solution is free of any alkali metal cations. 
     
     
         75 . The method as recited in  claim 64  wherein the reaction product has a total solubles content of less than about 1500 ppm. 
     
     
         76 . The method as recited in  claim 64  wherein the reaction product has a total solubles content of between about 50 to 800 ppm. 
     
     
         77 . The method as recited in  claim 64  wherein the amorphous aluminum phosphate has an oil absorption less than about 50. 
     
     
         78 . The method as recited in  claim 64  wherein the amorphous aluminum phosphate has a surface area less than about 20 m 2 /g. 
     
     
         79 . The method as recited in  claim 64  wherein the amorphous aluminum phosphate is amorphous aluminum hydroxyl orthophosphate. 
     
     
         80 . The method as recited in  claim 64  wherein the aluminum phosphate, when in dried particle form and placed into contact with moisture, has a controlled release of phosphate anion of between about 50 to 500 ppm. 
     
     
         81 . The method as recited in  claim 64  further comprising combining the aluminum phosphate particles with a binding polymer to form a composition, where the aluminum phosphate comprises 1 to 25 percent by weight of the total weight of the composition. 
     
     
         82 . The method as recited in  claim 81  wherein the binding polymer is selected from the group consisting of polyurethanes, polyesters, solvent-based epoxies, solventless epoxies, water-borne epoxies, epoxy copolymers, acrylics, acrylic copolymers, silicones, silicone copolymers, polysiloxanes, polysiloxane copolymers, alkyds and combinations thereof 
     
     
         83 . A method of making aluminum phosphate comprising the steps of:
 combining starting material consisting of aluminum hydroxide and phosphoric acid in the presence of water to form a mixture; and   reacting the mixture to form a reaction product of aluminum phosphate particles in aqueous media, the aluminum phosphate particles comprising amorphous aluminum phosphate, wherein the reaction product has a total solubles content of less than about 1,500 ppm.   
     
     
         84 . The method as recited in  claim 83  further comprising the step of drying the aluminum phosphate particles at a temperature of less than about 200° C. 
     
     
         85 . The method as recited in  claim 83  wherein the step of reacting takes place in the absence of added heat. 
     
     
         86 . The method as recited in  claim 83  wherein the aluminum phosphate, when in dried particle form and placed into contact with moisture, has a controlled delivery of phosphate anion of between about 50 to 500 ppm. 
     
     
         87 . The method as recited in  claim 83  wherein before the step of combining, adding water to the aluminum hydroxide. 
     
     
         88 . The method as recited in  claim 83  wherein during the step of combining, the phosphoric acid is added to the aluminum hydroxide. 
     
     
         89 . The method as recited in  claim 83  wherein the solution is free of any alkali metal cations. 
     
     
         90 . The method as recited in  claim 83  wherein during the step of combining, the starting materials are at room temperature. 
     
     
         91 . The method as recited in  claim 83  wherein the reaction product has a total solubles content of between about 50 to 800 ppm. 
     
     
         92 . The method as recited in  claim 83  wherein the aluminum phosphate particles have an oil absorption less than about 50. 
     
     
         93 . The method as recited in  claim 83  wherein the reaction product consists of aluminum phosphate. 
     
     
         94 . The method as recited in  claim 83  wherein during the step of combining, the phosphoric acid is added to the aluminum hydroxide. 
     
     
         95 . The method as recited in  claim 83  wherein during the step of combining, the aluminum hydroxide is added to the phosphoric acid. 
     
     
         96 . The method as recited in  claim 83  further comprising combining the aluminum phosphate particles with a binding polymer to form a composition, where the aluminum phosphate comprises 1 to 25 percent by weight of the total weight of the composition. 
     
     
         97 . The method as recited in  claim 96  wherein the composition additionally comprises a material comprising an element selected from the group consisting of zinc, calcium, strontium, chromate, borate, barium, molybdenum and combinations thereof. 
     
     
         98 . The method as recited in  claim 97  wherein the material comprises zinc. 
     
     
         99 . The method as recited in  claim 96  wherein at no point before combining the aluminum phosphate particles the binder polymer is the aluminum phosphate particles subject to a thermal treatment of above about 200° C. 
     
     
         100 . A method of making aluminum phosphate comprising the steps of:
 combining starting materials of aluminum hydroxide with phosphoric acid in an aqueous system to form a mixture;   reacting the mixture to form a reaction product consisting of aluminum phosphate particles in aqueous media, the aluminum phosphate particles comprising amorphous aluminum phosphate; and   drying the aluminum phosphate particles at a temperature less than about 200° C.   
     
     
         101 . The method as recited in  claim 100  wherein before the step of combining, adding water to the aluminum hydroxide. 
     
     
         102 . The method as recited in  claim 100  wherein the aluminum phosphate particles have an oil absorption less than about 50. 
     
     
         103 . The method as recited in  claim 100  wherein the aluminum phosphate, when in dried particle form and placed into contact with moisture, has a controlled delivery of phosphate anion of between about 50 to 500 ppm. 
     
     
         104 . The method as recited in  claim 103  wherein the aluminum phosphate particles are dispersed in a binding polymer to form a composition. 
     
     
         105 . A method of making a composition comprising an aluminum phosphate corrosion inhibiting pigment comprising the steps of:
 making aluminum phosphate by combining starting materials comprising aluminum hydroxide with phosphoric acid in an aqueous system to form a mixture, and reacting the mixture to form a reaction product of aluminum phosphate particles in aqueous media, wherein the aluminum phosphate particles comprise amorphous aluminum phosphate; and   combining the aluminum phosphate particles with a binding polymer, and wherein the aluminum phosphate particles are not subjected to a temperature above 200 C.° before the aluminum phosphate particles are combined with the binding polymer.   
     
     
         106 . The method as recited in  claim 105  wherein the amorphous aluminum phosphate has an oil absorption of less than about 50, and wherein the composition comprises in the range of from about 1 to 25 percent by weight of the amorphous aluminum phosphate. 
     
     
         107 . The method as recited in  claim 105  wherein the composition provides a controlled delivery of phosphate when in the form of a cured film, and wherein the composition has a total solubles content of from about 50 to 800 ppm, wherein the total solubles content includes the phosphate anion.