Лако-красочные материалы — производство

Waxes are used primarily in HMA formulations. Waxes are generally highly crystalline hydrocarbons. Waxes are added to HMA formulations to lower cost and decrease visc­osity. Some of the HMA properties that are affected by wax content are the softening point and open time. Typically, waxes are thermally stable. During high-temperature storage and compounding, however, waxes can discolor very rapidly. Degradation of a wax can result in a reduction in the thermooxidative stability of the overall HMA for­mulation. As shown in Fig. 14, the addition of an antioxidant during static oven aging at

177°C (350°F) of a microcrystalline wax can greatly reduce the degree of discoloration. The less volatile AO-2, at lower concentrations, significantly outperforms the more volatile AO-1. This reinforces the importance of volatility when an antioxidant is selected for a high-temperature application.