Raw materials formulations and properties of thermosetting powder coatings

Raw materials of Powder Coating
Powder coating is a multi-component mixture, generally composed of base material (resin+curing agent), filler, pigment and additives. Although there are only four major categories of raw materials, there are many types of each category. If each type has different application ratios, the resulting coatings can be thousands of types.
1. Binder: also known as film-forming substance, is an adhesive that forms a continuous film attached to the substrate and combines all components to form a film. The base material largely affects the film performance. The base material is mainly composed of resin Resins and curing agent
Acrylic resin, etc.:
Curing agents Crosslinker and Hardener: pure resin is a kind of brittle material, which cannot be used as coating film. The function of the curing agent is to react with the resin (the reaction must take place under specific conditions, such as heating). The combination of the two can improve the binding degree between the resin molecules, thus forming a whole network. From the resin that was brittle and hard and softened by heat, it became a tough coating film that could not be melted again. So this kind of material that can react with the resin to make it cross-link and solidify is called curing agent.

Although the reaction between each resin and the corresponding curing agent is different, it is a polymerization process as shown in the figure above. Temperature is very important in this transformation process. If the temperature does not meet the requirements and the time is not long enough (like the cooking time is not enough), the combination degree of the final curing agent and the resin cannot meet the requirements of toughness, which is unqualified
2. Pigment: Dispersed in the film base material to give the film color and opacity.
The coating film formed solely by the base material and non-pigmented coating is transparent, and in most cases we hope that the coating can provide various colors to achieve a decorative purpose. So color is an essential component in colored paint.
Each kind of pigment has specific visual and physical characteristics. The same is red pigment, but the first is the visual feeling. Secondly, in certain occasions, such as high temperature, many pigments will decompose and change color in case of high temperature, and some pigments with high oil absorption will cause the film to become flat and poor, so it is not a simple matter to add more pigments.

According to the gloss ,our product can be divided into High Gloss Powder Coating,Flat Gloss Powder Coating ,Semi-Gloss Powder Coating,Matte Powder Coating.