MELCROSS resins are the heat-convertible type and are used in baking coatings and occasionally in some  air-drying coatings.
They produce very hard, almost colorless films, but are quite brittle and have poor adhesion to metal surfaces.
It is fortunate that amino resins are compatible with a wide range of alkyd or acrylic resins because  the combination produces films having excellent properties.
The MELCROSS resins also have better heat stability  and alkali resistance, and they are preferred for applications requiring exterior exposure, such as automotive primers and topcoats, coil coating, appliance, container, general metal and wood coatings.