Two-component solvent-based coating composition, method for coating a substrate, coated substrate, and use of such coating composition for improving erosion resistance

A method for coating a substrate selected from rotor blades of wind turbines, rotor blades of helicopters, ship screws and aircraft, the method comprising:

• applying a two-component solvent-based coating composition to the substrate;
• and
• allowing the applied coating composition to cure,
• wherein the two-component, solvent-based coating composition comprises
• i) a base component comprising
• (A) one or more polyester diols having a hydroxyl value in the range of from 150 to 500 mg KOH/g polyester diol;
• (B) optionally one or more hydroxyl-functional acrylate resins having a hydroxyl value in the range of from 75 to 500 mg KOH/g resin;
• and
• (C) one or more organosilane-modified inorganic fillers;
• and
• ii) a curing component comprising
• (D) one or more polyisocyanates,
• in such amounts that the coating composition comprises:
• 5 to 50 wt % of the one or more polyester diols (A);
• 0 to 25 wt % of the one or more hydroxyl-functional acrylate resins (B);
• 10 to 70 wt % of the one or more organosilane-modified inorganic fillers (C);
• 5 to 40 wt % of the one or more polyisocyanates (D);
• wherein the base component comprises no resins other than the one or more polyester diols (A) and any hydroxyl-functional acrylate resins (B);
• the one or more polyisocyanates (D) are selected from trimers of di-isocyanates;
• the coating composition comprises one or more organic solvents in an amount in the range of from 5 to 35 wt %;
• and
• the coating composition has a viscosity in the range of from 50 to 2,000 mPa·s as measured by means of a rotary viscometer at a shear rate of 1000 s−1 and a temperature of 23° C., 30 seconds after combining and mixing the base component and the curing component.