초록 ▼

Described is a method for manufacturing a coal tar enamel-coated steel pipe, in which a primer coat of epoxy resin is applied to a preheated steel pipe, and coal tar enamel is applied to the primer coat prior to full curing of the latter. The resulting coated steel pipes, which also are described, e

Described is a method for manufacturing a coal tar enamel-coated steel pipe, in which a primer coat of epoxy resin is applied to a preheated steel pipe, and coal tar enamel is applied to the primer coat prior to full curing of the latter. The resulting coated steel pipes, which also are described, exhibit excellent resistance to cathodic disbondment, heat and water. In some embodiments the primer includes a silane coupling agent.

대표청구항 ▼

A method of forming a waterproofed steel surface on a steel pipe, comprising: preheating the steel surface to a temperature of at least about 55°C.; applying a primer consisting essentially of a thermally-curable epoxy resin composition to the preheated steel surface, wherein the epoxy resin composi

A method of forming a waterproofed steel surface on a steel pipe, comprising: preheating the steel surface to a temperature of at least about 55°C.; applying a primer consisting essentially of a thermally-curable epoxy resin composition to the preheated steel surface, wherein the epoxy resin composition begins to cure upon application to the steel surface; prior to completion of curing of said epoxy resin composition, applying a preheated top coating consisting essentially of coal tar enamel at a temperature of at least about 200°C. overtop said primer, said coal tar enamel having a softening point in the range of about 90°C. to about 130°C.; and cooling said steel surface, primer and top coating to form said waterproofed steel surface.