Method of forming a slurry of encapsulated pigment for an aqueous topcoat coating composition

A method of forming an aqueous topcoat coating composition, the method comprising:

• combining a resin and a pigment to form a pigment-resin slurry, wherein the pigment includes a plurality of flakes each having a surface;
• after combining, firstly reacting an orthosilicate and the pigment in the presence of the resin to form a coated pigment-resin slurry, wherein the coated pigment-resin slurry includes:
• the resin;
• and
• a coated pigment including the plurality of flakes each encapsulated by a first layer formed from the orthosilicate and disposed on the surface;
• concurrent to or after firstly reacting, secondly reacting the coated pigment-resin slurry and an organosilane compound having a hydrolysable group and an organic group to coat the first layer and thereby form the passivated pigment slurry, wherein the passivated pigment slurry includes:
• the resin;
• and
• a passivated pigment including the plurality of flakes each coated with a second layer disposed on the first layer;
• and
• blending the passivated pigment slurry, water, and at least one water-miscible film-forming binder to form the aqueous topcoat coating composition.

A method of forming an aqueous topcoat coating system, the method comprising:

• combining a resin and a pigment to form a pigment-resin slurry, wherein the pigment includes a plurality of flakes each having a surface;
• after combining, firstly reacting an orthosilicate with the pigment in the presence of the resin to form a coated pigment-resin slurry, wherein the coated pigment-resin slurry includes:
• the resin;
• and
• the plurality of flakes each encapsulated by a first layer formed from the orthosilicate and disposed on the surface;
• concurrent to or after firstly reacting, secondly reacting the coated pigment-resin slurry and an organosilane compound having a hydrolysable group and an organic group to coat the first layer and thereby form the passivated pigment slurry, wherein the passivated pigment slurry includes:
• the resin;
• and
• the plurality of flakes each coated with a second layer disposed on the first layer;
• blending the passivated pigment slurry, water, and at least one water-miscible film-forming binder to form an aqueous topcoat coating composition;
• applying a film formed from the aqueous topcoat coating composition to a substrate;
• and
• curing the film to form the aqueous topcoat coating system.