INFLUENCE OF CROSS-LINK DENSITY, GLASS-TRANSITION TEMPERATURE AND ADDITION OF PIGMENT AND WAX ON THE SCRATCH RESISTANCE OF AN EPOXY COATING

The scratch resistance of a series of cationically cured epoxy coating s with varying crosslink densities has been investigated using five di fferent scratch tests. The tests simulate a variety oi: scratch modes, ranging From single scratches to repeated surface wear. The relative influences of crosslink density and glass transition temperature on sc ratch resistance, as well as the effects of adding pigment and wax to the coatings, were examined. The results show the scratch resistance t o increase both with increasing crosslink density and increasing glass transition temperature in all tests. It is also shown that adding pig ment or wax either increased or decreased the scratch resistance of th e coating, depending on which type of scratching was performed.