Experimental Study of Atmospherically and Infrared-Dried Industrial Topcoats

Abstract

In this paper, five different solvent-borne industrial topcoats were dried with infrared (IR) radiation and under atmospheric conditions. A comparison of physical, mechanical, chemical, and electrochemical properties of differently dried topcoats was made. The results of differential scanning calorimetry (DSC), Fourier-Transform Infrared Spectroscopy (FTIR), and adhesion of a topcoat to the metal substrate (determined by the pull-off test) indicate a higher degree of crosslinking of examined topcoats, which improves the coating’s protective properties. Scratch hardness was determined by the pencil hardness test. Impact resistance was examined with a falling-weight test. Changes in the shade of the coating were examined by visual inspection and using a gloss meter. The electrochemical measurements of open circuit potential (OCP) and electrochemical impedance spectroscopy (EIS) were conducted. The thermal stability of topcoats was tested by thermogravimetric analysis (TGA). The results show overall better properties of IR-dried topcoats. In addition, topcoats dry significantly faster when IR radiation is applied, which makes this drying method very interesting for industrial application.