The main film-forming substances, secondary film-forming substances and auxiliary film-forming substances in coatings are distinguished as follows:
Main film-forming substances: The main film-forming substances are the main components that play a film-forming role in the coating, usually accounting for more than 50% of the total weight of the coating. These substances are directly involved in the formation of the coating film and play a decisive role in the performance and quality of the coating film. The main film-forming substances include resins, polymers, adhesives, etc.
Secondary film-forming substance: The secondary film-forming substance is an auxiliary component in the paint, accounting for 10%-50% of the total weight of the paint. Although these substances cannot directly form a film, they can play a synergistic role in the film-forming process and improve the performance and characteristics of the coating film. Common secondary film-forming substances include fillers, thickeners, pigments, solvents, etc.
Auxiliary film-forming substances: Auxiliary film-forming substances are other impurities and components in the coating, usually accounting for less than 1% of the total weight of the coating. These substances do not directly participate in the formation process of the coating film, but may have a certain impact on the performance and quality of the coating film. Auxiliary film-forming substances include solvent residues, bubbles, precipitates, impurities, etc.
To sum up, the main film-forming substances, secondary film-forming substances and auxiliary film-forming substances in coatings are mainly divided according to their roles and importance in coatings. The main film-forming substance is the key component that directly participates in the formation of the coating film, the secondary film-forming substance is the component that plays an auxiliary role in the coating process, and the auxiliary film-forming substance is the inevitable impurities and residues in the coating .
郑顺兴 - 《涂料与涂装科学技术基础》