Coatings and coating systems having optimized chip performance and methods of obtaining the same

A multilayer coating system consisting essentially of

• a substrate,
• an electrodeposition coating,
• a primer composition, comprising
• a film-forming binder, and
• a pigment mixture, said pigment mixture present in a pigment to binder
• ratio of at least 0.8 and consisting of
• (i) at least 80% of titanium dioxide by weight, based on the total weight of the pigment mixture, and
• (ii) no more than 20% by weight of non-titanium dioxide pigments based on the total weight of the pigment mixture, said non-titanium dioxide pigments being selected from the group consisting of carbon black, talc, barium sulfate, magnesium silicate, and combinations comprising two or more of the foregoing, and
• a topcoat,
• wherein the primer composition has an adjusted VOC of no more than 100 g/L, is free of all pigments other than those in the pigment mixture, and has a viscosity of no more than 200 cps (at 384 sec−1).

A method of making a multilayer coating system, consisting of

• applying a primer composition to a substrate to provide a primed substrate,
• applying a topcoat to the primed substrate, and
• curing the topcoat to provide a cured multilayer coating system,
• wherein the cured multilayer coating system has a chip performance of no more than 2% loss and the primer composition comprises
• a film-forming binder, and
• a pigment mixture, said pigment mixture present in a pigment to binder
• ratio of at least 0.8 and consisting of
• (i) at least 80% of titanium dioxide by weight, based on the total weight of the pigment mixture, and
• (ii) no more than 20% by weight of non-titanium dioxide pigments based on the total weight of the pigment mixture, said non-titanium dioxide pigments being selected from the group consisting of carbon black, talc, barium sulfate, magnesium silicate, and combinations comprising two or more of the foregoing,
• wherein the primer composition has an adjusted VOC of no more than 100 g/L, is free of all pigments other than those in the pigment mixture, has a viscosity of no more than 150 cps at 384 sec−1, and has an elasticity of at least 20% at a dry film build of from 0.8 to 2.0 mil on cold rolled steel.

A method of making a multilayer coating system having a chip performance of no more than 2% loss, comprising

• applying a primer composition to a substrate to provide a primed substrate, said primer composition having an elasticity of at least 20% at a dry film build of from 0.8 to 2.0 mil on cold rolled steel and comprising
• a film-forming binder, and
• a pigment mixture, said pigment mixture present in a pigment to binder
• ratio of at least 0.8 and consisting of
• (i) at least 80% of titanium dioxide by weight, based on the total weight of the pigment mixture, and
• (ii) no more than 20% by weight of non-titanium dioxide pigments based on the total weight of the pigment mixture, said non-titanium dioxide pigments being selected from the group consisting of carbon black, talc, barium sulfate, magnesium silicate, and combinations comprising two or more of the foregoing,
• applying a topcoat to the primed substrate, and
• curing the topcoat to provide a cured multilayer coating system,
• wherein the cured multilayer coating system has a chip performance of no more than 2% loss.