Coating system, a method of applying the coating system and an article comprising the coating system

A method of applying a multi-layer coating system comprising:

• (I) selecting an epoxy formulation which comprises
• (a1) epoxy resin;
• (a2) curing agent with no more than 4.5 wt % free amine based on a weight solids of the curing agent;
• and
• (II) applying the epoxy formulation onto a substrate;
• (III) fully or partially curing the epoxy formulation to produce an epoxy coating layer;
• (IV) selecting a non-isocyanate polyurethane formulation;
• (V) applying the non-isocyanate polyurethane formulation onto the epoxy coating layer;
• and
• (VI) allowing the topcoat formulation and epoxy formulation to fully cure thereby forming a multi-layer coating system;
• wherein the epoxy formulation and/or non-isocyanate polyurethane formulation optionally further comprise one or more additives selected from the group consisting of solvent, reactive diluent, plasticizer, pigment, filler;
• rheology modifiers, dispersants, surfactants, UV stabilizers, and corrosion inhibitors.

An article comprising:

• a substrate which comprises a surface:
• an epoxy coating layer prepared from an epoxy formulation which comprises an epoxy resin;
• a curing agent with no more than 4.5 wt % free amine based on weight solids of the curing agent;
• and
• a non-isocyanate polyurethane coated onto the epoxy coating layer;
• wherein the epoxy formulation and/or non-isocyanate polyurethane formulation optionally further comprise one or more additives selected from the group consisting of solvent, reactive diluent, plasticizer, pigment, filler;
• rheology modifiers, dispersants, surfactants, UV stabilizers, and corrosion inhibitors.