Improving the scratch resistance of sol–gel metal oxide coatings cured at 250 °C through use of thermogenerated amines

Abstract

Scratch resistant sol–gel metal oxide coatings typically require a thermal post-treatment step (curing process) at temperatures between 400 and 700 °C. In this report, we demonstrate that the in situ generation of amines within sol–gel films facilitates the preparation of scratch resistant metal oxide coatings at a curing temperature of 250 °C. A selected series of carbamates was added to sol–gel formulations and included in the resulting xerogel films. During the curing process, the carbamates decomposed to liberate primary amines. These catalysed the curing process, finally leading to scratch resistant metal oxide coatings at low cure temperature.