Epoxy coatings with modified montmorillonites

Two types of modified layered aluminosilicates (montmorillonites) with different grain size and gallery spaces were tested as nanofillers in epoxy coating compositions for a steel substrate. Organophilic montmorillonites, in the amount of 2.5 and 5 wt% were introduced to waterborne and to solvent-type epoxy coating materials (based on bisphenol-A epoxy resins and various curing agents). The results of this work indicate that processing properties of coating compositions (leveling and drying time) as well as mechanical properties of coatings (hardness, scratch and abrasion resistance, adhesion to steel) were positively affected by a layered aluminosilicate nanofiller. Enhanced water resistance (lower water absorbance) of coats, especially those formed from waterborne compositions, has been found.