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Mixing Properties Of Powder And Polyester Resin
Oct 17, 2017

It is widely believed that polyester resin powder coating is the most ideal powder coating in epoxy, epoxy/polyester, polyester and acrylic powder coatings, and the powder coating has developed rapidly in recent years. Polyester resin is a key component of thermosetting powder coating, its performance directly affects the performance of powder coating.Powder 

Although China's polyester resin products have been able to meet user requirements, but in the use of performance stability and other aspects of the developed countries still have a certain gap. How to effectively control the intermediate products and the physical parameters of the final products in the synthesis of polyester resin becomes the problem of our research. I think the melt viscosity of polyester resin is an important factor.Powder The main raw materials for synthesis of polyester resin were the selection of new amyl alcohol and terephthalic acid. In the synthesis of the polyester resin cured with cyanuric acid triglyceride (TGIC), the esterification reaction stage requires excessive alcohol, and the degree of alcohol excess directly affects the melt viscosity of polyester resin, and then affects the properties of the powder coating. The acid/alcohol ratio of synthetic polyester resin is too small under the same conditions as the control endpoint acid value and acid solution additive. The obtained polyester resin becomes the end hydroxyl polyester, or even if the end carboxyl polyester is synthesized, but the polyester resin melts through the big, resulting in the powder coating coating the orange peel serious, the polyester resin crushing difficult; acid/alcohol ratio is too large, the resin molecular weight is low, The viscosity is small, the mechanical property of powder coating coating is poor, the thick side of coating is produced, and the pinhole and shrinkage are generated.Powder

In polyester resin synthesis, if there is oxygen in the case of existence, polyester resin will have a thermal oxidation degradation reaction, that is, first in the chain and chain segments lively center to produce peroxide, resulting in polyester resin structure of the chain and chain segments of the cracking, resulting in resin end carboxyl increase, color yellow, melt viscosity decline. According to the mechanism of thermal oxidative degradation, besides the protection of N 2, antioxidant is needed to inhibit the degradation reaction.Powder