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How To Solve The Color Difference Of Powder Coating?

Sep 17, 2020

Regarding the organic pigment pre-dispersion for powder coatings, that is, the color matching of powder coatings often has the problem of color difference between batches. Many companies around the world are working hard to solve related technical problems and develop multi-oxidation solutions and high-performance products. Among them: Merck adopts Benda-Lutz's new bonding process to bond flake pigments to the surface of dry powder particles without damaging the flake structure of the pigment. This process has a high degree of color consistency; ZEn-gelhard has developed 9 types Bright organic pigments suitable for powder coatings; AkzoNobel has developed a color matching system for powder coatings, which can quickly be formulated into powder coatings of various gloss and various tones; Backer Powder Coatings has developed a series of powder coatings with the effect of simulating wood texture. Shows the surface pattern of painted wood; CibaGeigy and Sun Chemical Company successfully developed organic pigment pre-dispersions, which can better solve the color saturation problem of light and dark powder coatings. The use of organic material pre-dispersion can reduce the color difference between batches and reduce weighing errors. This is due to the increase in the amount of pigment preparation. Therefore, it has become an easy task to mix the color of the powder with white pigments and a small amount of color pigments, especially with carbon black. The high tinting strength of this pre-dispersion also reduces the amount of flutter used. The organic pigment pre-dispersion is prepared by formulating special organic pigments into a wet "filter cake" of 40-50% water, and then mixing it with the resin in a kneader. The water is squeezed out from the surface of the pigment through a series of processing techniques and dispersed in polyester with a Tg of about 58°C. It is suitable for interior decoration and has good thermal stability. It is chemically stable to commonly used powder coating resins and curing agents, pigment particles are uniform, and it has good performance in thin coatings and high-gloss powder coatings. In the production of powder coatings, the storage of intermediate products should be as little as possible. Based on this idea, Akzo Nobol Powder Coatings has developed a unique powder coating that can quickly match colors and provide powder coating formulations of any color, including RAL color and BS color. , NCS color and various non-standard tones, gloss 20-90%, and use TGIC-free polyester system. This process can be automated to produce qualified products in a short time. It can provide various top coats with gloss, satin gloss and flat gloss. By using a unique matting base material, a flat polyester powder coating can be obtained, which is much better than traditional flat polyester powder coatings. The company plans to build more color matching systems in Europe and around the world.