The composition and classification of coatings

Paint Composition: Paints generally consist of non-volatile and volatile components. After being applied to a surface, the volatile components gradually evaporate, leaving behind the non-volatile components which dry to form a film. Therefore, the non-volatile components are also known as film-forming substances. Film-forming substances can be classified into three categories: primary, secondary, and auxiliary. Primary substances can form films independently or together with secondary film-forming substances such as adhesives. They are the basis of the paint and are referred to as the base material. The various components of a paint can be composed of a variety of raw materials.

2022-04-28

Introduction to Common Types of Polyurethane Coatings

(1) Polyurethane modified paint This coating is also known as urethane oil. First, the drying oil is transesterified with polyol, and then reacted with diisocyanate. Its drying is carried out in air through double bond oxidation, and this paint dries quickly. Due to the presence of amide groups, its abrasion resistance, alkali resistance and oil resistance are increased. It is suitable for indoor, wood and cement surface coating, but it has poor leveling, easy yellowing, and color paint is easy to powder. (2) Hydroxyl-cured polyurethane coating It is generally a two-component coating. Component A contains isocyanate groups, and component B generally contains hydroxyl groups. When used, components A and B are mixed and coated to allow the isocyanate groups to react with the hydroxyl groups.

2022-04-28