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2020

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What issues should be taken into account when using matting agents? What’s the difference between matting agents and matting powders?

　　Depending on the intended application, matting agents may require powder coatings that are either semi-gloss or matte. To reduce the gloss of the coating film, commonly used matting agents include ultrafine silica, talc, aluminum stearate, calcium stearate, and low-molecular-weight thermoplastic resins. To achieve a matting effect, the following methods can be employed:
　　a. When powder coatings with different curing speeds are mixed using a dry-blending method, the resulting coating film exhibits significantly reduced gloss and achieves an anti-gloss effect. This is because the highly reactive powder coating cures rapidly, thereby impeding the leveling and reaction of the resin in the continuous phase, which has a slower curing rate. As a result, the final cured coating film loses its gloss. Although this method is effective, it increases manufacturing processes and costs.
　　b. Add thermoplastic resins. Adding cellulose acetate to epoxy powder coatings and fine, low-molecular-weight polyethylene or polypropylene resins to polyester powder coatings can produce matte powder coatings. The gloss of the coating film is influenced by manufacturing conditions. The addition of thermoplastic resins will affect the powder. c. Use special curing agents with matting effects.
　　d. Add fillers with matting effects. Adding ultrafine silica, talc, and other fillers can significantly reduce gloss. In particular, the particle size of the filler has a substantial impact on the gloss of the coating film; the larger the particle size, the lower the gloss. It’s important to note that increasing the amount of filler will degrade the smoothness and mechanical strength of the coating film. In epoxy powder coatings, the effect of calcium carbonate particle size on coating gloss is shown in the table. In acrylic and polyester powder coatings, adding ultrafine silica and kaolin can produce matte coatings. In addition, incorporating wax-like substances such as polyethylene paraffin and hydrogenated castor oil can also yield matte coatings.
　　The difference between matting agents and matting powders:
　　The matting agent is a pale yellow transparent liquid or a black liquid, suitable for various inks, resins, coatings, liquid silicone rubber, and low-viscosity two-component silicone potting compounds.
　　The mechanism behind matte finishes: When light strikes a rough surface, the reflected light undergoes scattering, resulting in reduced gloss. The L-1030/1031 matting agent works precisely on this principle of light scattering. As the adhesive dries, the matting agent within the adhesive forms a microscopically rough surface on the adhesive’s surface. When incident light hits this roughened surface, it undergoes slow scattering, producing a strong matte effect.
　　Matting agents are simple, easily dispersed chemical substances that have undergone organic treatment. They are a type of coating additive whose primary function is to reduce the gloss of the coated film. Commonly used matting agents include ultrafine silica, talc, aluminum stearate, calcium stearate, and low-molecular-weight thermoplastic resins.

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