According to the different coloring requirements of pigments in coatings, many coating systems have certain requirements on the heat resistance of pigments. That is to say, it is required that the color of the pigment itself and the color of the colored object do not change in shade and coloring intensity under different heating conditions. For example, powder coatings, coil coatings, hydrophilic aluminum coatings, plastic paints, etc. must withstand a certain temperature during the manufacturing or construction process. For example, it is generally required to resist discoloration in environments ranging from 140-250 ℃. High requirements Resistant to high temperatures above 300°C. Pigments with poor heat resistance will be seriously discolored, so the determination of heat resistance of pigments can help select pigments that can withstand a certain temperature range.
Factors that mainly affect the heat resistance of pigments include their own chemical structure, molecular polarity, molecular composition, specific substituent groups , intermolecular hydrogen bonds, etc. Certain chemical reactions, etc.) will also affect the thermal stability of the pigment. Pigments with poor heat resistance may undergo the following : thermal decomposition of the pigment, chemical reaction between the pigment and the application medium, a marked increase in the solubility of the pigment in the medium, changes in the particle size and physical properties of the pigment resulting in Color changes.
