Low temperature cure coating formed via a double layer curing mechanism of a pigmented waterborne baselayer and a solventborne top layer

A low temperature cure composite coating, comprising:

• a substrate;
• a first layer comprising a waterborne low temperature cure coating composition comprising
• a first hydroxy-functional resin, which is a hydroxy-functional polyether-comprising polyurethane,
• a first low temperature crosslinking agent, which is an aminoplast resin, and
• a first catalyst, which is a metal catalyst, and
• water;
• and
• a second layer comprising a solventborne low temperature cure coating composition comprising
• a second hydroxy-functional resin, which is a hydroxy-functional acrylic resin or a hydroxy-functional polyester resin;
• a second low temperature crosslinking agent, which is an isocyanate resin that is optionally blocked,
• a second catalyst, which is an acid catalyst, and
• an organic solvent,
• wherein the first layer and the second layer are adjacent to each other,
• wherein the first catalyst catalyzes a crosslinking reaction between the second hydroxy-functional resin and the second low temperature crosslinking agent, and does not catalyze a crosslinking reaction between the first hydroxy-functional resin and the first low temperature crosslinking agent,
• wherein the second catalyst catalyzes a crosslinking reaction between the first hydroxy-functional resin and the first low temperature crosslinking agent, and does not catalyze a crosslinking reaction between the second hydroxy-functional resin and the second low temperature crosslinking agent, and
• wherein the solventborne and the waterborne low temperature cure coating compositions cure within 20 minutes at a temperature from 80-120° C.