Introduction of High Temperature Anti - yellowing Agent
High temperature anti-yellowing agent is powder coating in the baking curing, in order to prevent the film yellowing and the addition of auxiliaries, this auxiliaries generally added in white or light color powder coating varieties. One of the shortcomings of powder coating is high baking temperature, most varieties of baking temperature in 180℃ or so, in order to improve production efficiency, often increase the baking curing temperature to shorten the baking curing time. In this case, the oxidation of high temperature organic polymer compounds is more obvious, so the powder coating film is more likely to become yellow or discolored. Additional, breed of coating of some powder is in the direct illuminate of sunlight or indirect illuminate fall, also can produce besmear film yellow change problem.
Resistance to yellowing agent is added in powder coating formula or antioxidant goal is to reduce and overcome powder coating, the effect of air and sunlight under high temperature yellowing problems, the resistance to yellowing agent or antioxidants in aerobic when heated by capturing film thermal degradation reaction of free radicals and prevent film, thus improve the coating yellow degeneration resistance and aging resistance. High temperature anti-yellowing agents used in powder coatings include QR7014 of Shanghai qungrong new material technology co., LTD., which can withstand 250 ° c for 10 minutes and 230 ° c for 20 minutes to protect organic and polymer compounds from oxidative degradation and play the role of anti-yellowing.