Tank or pipe having a coating system
AssigneePPG Coatings Europe B.V.
InventorsArnold Nederlof, Kees Van Der Kolk, Arjen Vellinga, Nathan J. Silvernail, Brian C. Okerberg
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Abstract
A tank or a pipe having an internal steel surface, at least a portion of the internal steel surface comprising a coating system. The coating system being formed of an overcoat layer and an overcoat-enhancing layer, the overcoat-enhancing layer being interposed between the steel surface and the overcoat layer. In use, the overcoat-enhancing layer enhances the chemical resistance of the overcoat layer to aggressive cargo types.
Claims7
A tank or a pipe having an internal steel surface, wherein at least a portion of the internal steel surface comprises a coating system, the coating system comprising:
- a. an overcoat layer comprising epoxy, silicate, polyurethane, polyurea, and/or vinyl esters;
- and
- b. an overcoat-enhancing layer having a thickness between 10 nm to 2 μm, the overcoat-enhancing layer comprising a composition based on a group IIIB or IVB metal compound from the periodic table of elements, silane compound, metal alkoxide, zinc phosphate or mixtures thereof;
- wherein at least a portion of the internal steel surface has a surface roughness prior to the application of the coating system of 20 μm to 150 μm;
- the overcoat-enhancing layer being interposed between the internal steel surface and the overcoat layer, wherein the internal steel surface comprising the coating system is flat compared to an internal steel surface having the overcoat layer but not the overcoat-enhancing layer following exposure of the internal steel surface comprising the coating system and the internal steel surface having the overcoat layer but not the overcoat-enhancing layer to methyl ethyl ketone (40° C., 2 weeks).
A tank or pipe coating system for application to at least a portion of an internal steel surface of a tank or pipe, the coating system comprising:
- a. an overcoat layer comprising epoxy, silicate, polyurethane, polyurea, and/or vinyl esters;
- and
- b. an overcoat-enhancing layer having a thickness between 10 nm to 2 μm, the overcoat-enhancing layer comprising a composition based on a group IIIB or IVB metal compound from the periodic table of elements, silane compound, metal alkoxide, zinc phosphate or mixtures thereof;
- wherein at least a portion of the internal steel surface has a surface roughness prior to the application of the coating system of 20 μm to 150 μm;
- the overcoat-enhancing layer being interposed between the internal steel surface and the overcoat layer, wherein the internal steel surface comprising the coating system is flat compared to an internal steel surface having the overcoat layer but not the overcoat-enhancing layer following exposure of the internal steel surface comprising the coating system and the internal steel surface having the overcoat layer but not the overcoat-enhancing layer to methyl ethyl ketone (40° C., 2 weeks).
A method of increasing the chemical resistance of an overcoated steel surface, the method comprising interposing an overcoat-enhancing layer comprising a composition based on a group IIIB or IVB metal compound from the periodic table of elements, silane compound, metal alkoxide, zinc phosphate or mixtures thereof and having a thickness between 10 nm to 2 μm between a steel surface and an overcoat coating layer comprising epoxy, silicate, polyurethane, polyurea, and/or vinyl esters, wherein at least a portion of the steel surface has a surface roughness prior to the interposing of the overcoat-enhancing layer of 20 μm to 150 μm.
Dependencies are inferred from the claim text.