Anticorrosion coating composition in aqueous dispersion comprising an organic titanate and/or zirconate

Abstract

The present invention relates to an anticorrosion coating composition for metallic parts based on particulate metal in aqueous dispersion comprising an organic titanate or zirconate compatible in aqueous phase or in organic phase, optionally a silane-based binder, and water. The present invention likewise relates to an anticorrosion coating of metallic parts obtained from the coating composition according to the invention as well as a metallic substrate provided with this anticorrosion coating. The invention additionally relates to an aqueous composition of C 1 -C 8 tetraalkyl titanate, intended for the preparation of a coating composition of a metallic substrate in aqueous dispersion, as well as the process for preparation of such a composition.

1 . An anticorrosion coating composition of metallic parts based on particulate metal in aqueous dispersion comprising, in the following proportions (percentages by weight): 
 at least one of an organic titanate and an organic zirconate in an amount from 0.3 to 24%;    a particulate metal or a mixture of particulate metals in an amount from 10 to 40%;    a silane-based binder in an amount from 1 to 25%; and    water in an amount sufficient to produce 100%;    wherein the sum of the organic titanate and/or zirconate and of the silane-based binder is between 5 and 25%.    
     
     
         2 . The composition according to  claim 1 , characterized in that wherein (i) the organic titanate is selected from the group consisting of titanates compatible in organic phase, compatible in aqueous phase, and combinations thereof, and (ii) the organic zirconate is selected from the group consisting of zirconates compatible in organic phase, zirconates compatible in aqueous phase, and combinations thereof.  
     
     
         3 . The composition according to  claim 2 , wherein the titanates compatible in organic phase are C 1 -C 8  tetraalkyl titanates, and the zirconates compatible in organic phase are C 1 -C 8  tetraalkyl zirconates.  
     
     
         4 . The composition according to  claim 2 , wherein the titanates compatible in aqueous phase are chelated organic titanates, and the zirconates compatible in aqueous phase are chelated organic zirconates.  
     
     
         5 . The composition according to  claim 1  wherein the particulate metal is selected from the group consisting of zinc, aluminium, zinc alloys, aluminium alloys, zinc and aluminium alloys, and combinations thereof.  
     
     
         6 . The composition according to  claim 1  wherein the silane-based binder comprises a silane having at least one hydrolysable function.  
     
     
         7 . The composition according to  claim 1  wherein the silane includes an epoxy function.  
     
     
         8 . The composition according to  claim 7 , wherein the silane is selected from the group consisting of di- or trimethoxysilane with an epoxy function, di- or triethoxysilane with an epoxy function, and mixtures thereof.  
     
     
         9 . The composition according to  claim 1 , further comprising 1 to 30% by weight of organic solvent or a mixture of organic solvents, with respect to the total weight of the composition.  
     
     
         10 . The composition according to  claim 9 , wherein the organic solvent is selected from the group consisting of glycolic solvents, acetates, nitropropane, alcohols, ketones, white spirit, and mixtures thereof.  
     
     
         11 . The composition according to  claim 1  further comprising 0.1 to 7% by weight of molybdenum oxide, with respect to the total weight of the composition.  
     
     
         12 . The composition according  claim 1  further comprising 0.5 to 10% by weight, with respect to the total weight of the composition, of an anticorrosion reinforcing agent selected from the group consisting of yttrium, zirconium, lanthanum, cerium, praseodymium, in the form of oxides or of salts thereof.  
     
     
         13 . The composition according to  claim 1  further comprising at least one of a thickening agent.  
     
     
         14 . A method for forming an anticorrosion coating of metallic parts, the method comprising: 
 obtaining a coating composition comprising, in the following proportions (percentages by weight): at least one of an organic titanate and an organic zirconate in an amount from 0.3 to 24%, a particulate metal or a mixture of particulate metals in an amount from 10 to 40%, a silane-based binder in an amount from 1 to 25%, and water in an amount sufficient to produce 100%, wherein the sum of the organic titanate and/or zirconate and of the silane-based binder is between 5 and 25%;    forming a coating layer by spraying, soaking-draining or soaking-centrifugation; and    subjecting the coating layer to a baking operation by supply of thermal energy to thereby form the anticorrosion coating.    
     
     
         15 . The method according to  claim 14 , further comprising, prior to the baking operation, the coated metallic parts are subjected to a drying operation by supply of thermal energy.  
     
     
         16 . The method according to  claim 14 , wherein the anticorrosion coating has a thickness of the dry film of between 3 μm (11 g/m 2 ) and 30 μm (110 g/m 2 ).  
     
     
         17 . A coated metallic substrate comprising an anticorrosion coating formed from a coating composition including in the following proportions (percentages by weight): at least one of an organic titanate and an organic zirconate in an amount from 0.3 to 24%, a particulate metal or a mixture of particulate metals in an amount from 10 to 40%, a silane-based binder in an amount from 1 to 25%, and water in an amount sufficient to produce 100%, wherein the sum of the organic titanate and/or zirconate and of the silane-based binder is between 5 and 25%.  
     
     
         18 . An aqueous composition of C 1 -C 8  tetraalkyl titanate, adapted for use in a coating composition for a metallic substrate in aqueous dispersion, in the following proportions (percentages by weight): 
 water-soluble organic solvent in an amount from 0 to 20%;    silane-based binder in an amount from 20 to 50%, the silane having at least one hydrolysable hydroxyl function;    at least one of C 1 -C 8  tetraalkyl titanate and zirconate in an amount from 5 to 25%, compatible in organic phase; and    water in an amount sufficient to produce 100%.    
     
     
         19 . The composition according to  claim 18 , wherein the water-soluble organic solvent is selected from the group consisting of glycolic solvents, alcohols, ketones, and mixtures thereof.  
     
     
         20 . The composition according to  claim 18 , wherein the hydrolysable hydroxyl function is a C 1 -C 4  alkoxy radical.  
     
     
         21 . The composition according to  claim 18 , wherein the silane includes an epoxy function.  
     
     
         22 . The composition according to  claim 21 , wherein the silane is selected from the group consisting of di- or trimethoxysilane with an epoxy function, di- or triethoxysilane with an epoxy function, and mixtures thereof.  
     
     
         23 . The composition according to  claim 18 , wherein the C 1 -C 8  tetraalkyl titanate is selected from the group consisting of tetraethyl titanate, tetra-n-butyl titanate, octylene glycol titanate and mixtures thereof.  
     
     
         24 . (canceled)  
     
     
         25 . The composition according to  claim 3  wherein the C 1 -C 8  tetraalkyl titanates are selected from the group consisting of tetraethyl titanate, tetra-n-butyl titanate, octylene glycol titanate, and combinations thereof.  
     
     
         26 . The composition according to  claim 3  wherein the C 1 -C 8  tetraalkyl zirconates are selected from the group consisting of tetra-n-propyl zirconate, tetra-n-butyl zirconate, and combinations thereof.  
     
     
         27 . The composition according to  claim 4  wherein the chelated organic titanates are triethanolamine titanates.  
     
     
         28 . The composition according to  claim 4  wherein the chelated organic zirconates are triethanolamine zirconates.  
     
     
         29 . The composition according to  claim 5  wherein the alloys include metals selected from the group consisting of manganese, magnesium, tin, and combinations thereof.  
     
     
         30 . The composition according to  claim 5  wherein the alloys include a eutectic alloy of zinc and aluminium and a trace of rare earth elements.  
     
     
         31 . The composition according to  claim 6  wherein the hydrolysable hydroxyl function is a C 1 -C 4  alkoxyl radical.  
     
     
         32 . The composition according to  claim 8  wherein the trimethoxysilane is selected from the group consisting of gamma-glycidoxypropyltrimethoxysilane, beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and mixtures thereof.  
     
     
         33 . The composition according to  claim 10  wherein the glycolic solvents are glycol ethers.  
     
     
         34 . The composition according to  claim 33  wherein the glycol ethers are selected from the group consisting of diethylene glycol, triethylene glycol, dipropylene glycol, propylene glycol methyl ether, and mixtures thereof.  
     
     
         35 . The composition according to  claim 10  wherein the glycolic solvents are selected from the group consisting of propylene glycol, polypropylene glycol, and mixtures thereof.  
     
     
         36 . The composition according to  claim 9  wherein the organic solvent is 2,2,4-trimethyl-1, 3-pentanediol isobutyrate (texanol).  
     
     
         37 . The composition according to  claim 12  wherein the reinforcing agent is yttrium oxide Y 2 O 3 .  
     
     
         38 . The composition according to  claim 1  further comprising 0.2 to 4% by weight, with respect to the total weight of the composition, of a corrosion inhibitor pigment.  
     
     
         39 . The composition according to  claim 38  wherein the corrosion inhibitor pigment is aluminium triphosphate.  
     
     
         40 . The composition according to  claim 13  wherein the thickening agent is present in an amount of 0.005 to 7% by weight with respect to the total weight of the composition.  
     
     
         41 . The composition according to  claim 13  wherein the wetting agent is present in an amount of 0.1 to 4% by weight with respect to the total weight of the composition.  
     
     
         42 . The method according to  claim 14  wherein the baking operation by supply of thermal energy includes at least one of convection, infrared, and induction.  
     
     
         43 . The method according to  claim 14  wherein the baking operation is performed at a temperature between 180° C. and 350° C.  
     
     
         44 . The method according to  claim 43  wherein the baking operation is performed for approximately 10 to 60 minutes by convection or infrared.  
     
     
         45 . The method according to  claim 43  wherein the baking operation is performed for 30 seconds to 5 minutes by induction.  
     
     
         46 . The anticorrosion coating formed by the method according to  claim 14 .  
     
     
         47 . The method according to  claim 15  wherein the drying operation by supply of thermal energy includes at least one of convection, infrared, and induction.  
     
     
         48 . The method according to  claim 47  wherein the drying operation is performed at a temperature between 30° C. and 250° C. by convection.  
     
     
         49 . The method according to  claim 47  wherein the drying operation is performed for approximately 10 to 30 minutes on a line.  
     
     
         50 . The method according to  claim 47  wherein the drying operation is performed for 30 seconds to 5 minutes by induction.  
     
     
         51 . The anticorrosion coating formed by the method according to  claim 15 .  
     
     
         52 . The method according to  claim 16  wherein the thickness is between 4 μm (15 g/m 2 ) and 12 μm (45 g/m 2 ).  
     
     
         53 . The method according to  claim 52  wherein the thickness is between 5 μm (18 g/m 2 ) and 10 μm (40 g/m 2 ).  
     
     
         54 . The anticorrosion coating formed by the method of  claim 16 .  
     
     
         55 . The method according to  claim 15  wherein the anticorrosion coating has a thickness of the dry film of between 3 μm (11 g/m 2 ) and 30 μm (110 g/m 2 ).  
     
     
         56 . The method according to  claim 55  wherein the thickness is between 4 μm (15 g/m 2 ) and 12 μm (45 g/m 2 ).  
     
     
         57 . The method according to  claim 56  wherein the thickness is between 5 μm (18 g/m 2 ) and 10 μm (40 g/m 2 ).  
     
     
         58 . The anticorrosion coating formed by the method of  claim 55 .  
     
     
         59 . The metallic substrate of  claim 17  wherein the metallic substrate is selected from the group consisting of steel, cast-iron, and aluminium.  
     
     
         60 . The metallic substrate of  claim 59  wherein the steel is zinc coated.  
     
     
         61 . The composition of  claim 19  wherein the glycolic solvents include glycol ethers.  
     
     
         62 . The composition of  claim 61  wherein the glycol ethers are selected from the group consisting of diethylene glycol, triethylene glycol, dipropylene glycol, and mixtures thereof.  
     
     
         63 . The composition of  claim 19  wherein the glycolic solvents include propylene glycol, propylene glycol methyl ether, and mixtures thereof.  
     
     
         64 . The composition according to  claim 19  wherein the hydrolysable hydroxyl function is a C 1 -C 4  alkoxyl radical.  
     
     
         65 . The composition according to  claim 22  wherein the trimethoxysilane is selected from the group consisting of gamma-glycidoxypropyltrimethoxysilane, beta-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and mixtures thereof.  
     
     
         66 . The composition according to  claim 18  wherein the C 1 -C 8  tetraalkyl zirconate is selected from the group consisting of tetra-n-propyl zirconate, tetra-n-butyl zirconate, and mixtures thereof.  
     
     
         67 . A method for pretreating a substrate prior to receiving an adhesive or coating, the method comprising: 
 providing a composition comprising in the following proportions (percentages by weight): water-soluble organic solvent in an amount from 0 to 20%, silane-based binder in an amount from 20 to 50% the silane having at least one hydrolysable hydroxyl function, at least one of C 1 -C 8  tetraalkyl titanate and zirconate in an amount from 5 to 25% compatible in organic phase, and water in an amount sufficient to produce 100%;    applying a coating of the composition to the substrate, to thereby pretreat the substrate.    
     
     
         68 . A method for sealing a substrate or coated substrate, the method comprising: 
 providing a substrate or coated substrate;    providing a composition comprising in the following proportions (percentages by weight): water-soluble organic solvent in an amount from 0 to 20%, silane-based binder in an amount from 20 to 50% the silane having at least one hydrolysable hydroxyl function, at least one of C 1 -C 8  tetraalkyl titanate and zirconate in an amount from 5 to 25% compatible in organic phase, and water in an amount sufficient to produce 100%;    applying a coating of the composition on the substrate, to thereby seal the substrate or coated substrate.    
     
     
         69 . A method for passivating a substrate of steel, zinc, aluminium, or steel having a zinc-based coating, the method comprising: 
 providing a substrate selected from the group consisting of steel, zinc, aluminium, and steel having a zinc-based coating;    providing a composition comprising in the following proportions (percentages by weight): water-soluble organic solvent in an amount from 0 to 20%, silane-based binder in an amount from 20 to 50% the silane having at least one hydrolysable hydroxyl function, at least one of C 1 -C 8  tetraalkyl titanate and zirconate in an amount from 5 to 25% compatible in organic phase, and water in an amount sufficient to produce 100%;    applying a coating of the composition on the substrate, thereby -passivating the substrate.    
     
     
         70 . A method for improving the adhesion of coatings or adhesives in aqueous phase, the method comprising: 
 forming a composition comprising in the following proportions (percentages by weight): water-soluble organic solvent in an amount from 0 to 20%, silane-based binder in an amount from 20 to 50% the silane having at least one hydrolysable hydroxyl function, at least one of C 1 -C 8  tetraalkyl titanate and zirconate in an amount from 5 to 25% compatible in organic phase, and water in an amount sufficient to produce 100%;    adding the composition to a coating or adhesive to thereby improve the resulting adhesion of the coating or adhesive.