High-solids coating composition for improved rheology control containing chemically modified inorganic microparticles

An essentially solvent-based, organic, high-solids coating composition which is conventionally sprayable at high-solids comprising:

• (A) a film-forming binder system containing a crosslinkable resin having a weight average molecular weight of from about 500 to about 10,000, and optionally a crosslinking agent for the crosslinkable resin;
• (B) substantially colorless, substantially inorganic, microparticles stably dispersed in the coating composition, the microparticles prior to incorporation in the coating composition ranging in size from about 1 to about 150 nanometers and in the form of a sol of the microparticles in which carbon-containing molecules are chemically bonded to the surface of the inorganic microparticles;
• (C) a solvent system for the crosslinkable resin and the optional crosslinking agent;
• and
• (D) a metallic-flake pigment;
• wherein the crosslinkable resin is in an amount of from about 15 to about 95 percent by weight and the substantially inorganic mircoparticles are in an amount of from about 1 to about 20 percent by weight, based on the sum of the weights of the crosslinkable resin, the optional crosslinking agent, and the inorganic microparticles.