5 piece of suggestions to choose HAA as the curing agent for outdoor Polymer resin powder coating product.

 DOWNLOAD

HAA curing agent has high reactivity, and the reaction with carboxyl polyester belongs to polycondensation reaction, and no catalyst is needed. The influence of pigment composition on the reaction rate is also very slight. The reactive activity of polyester in the HAA system is lower than that of the TGIC system, to prolong the reaction time, that is, to increase the time of coating flow and water vapor overflow. HAA dosage for polyester resin with acid value of about 34mgKOH/g, the recommended dosage is 6% of polyester; For polyester resin with acid value of about 22mgKOH/g, the recommended dosage is 5% of polyester.
 
 
HAA is very soluble in water, it is a hydrophilic substance, and a small amount of condensed water vapor is easily formed on the surface. When HAA powder is extruded, crushed, or stored, if the temperature difference is large, it will be found that the powder is wet, especially in hot summer. After moisture absorption, the powder is poorly coated and the adhesion of the coating film is poor. It is more effective to reduce humidity or use the air conditioner to reduce temperature differences in the production environment. Degussa R972 hydrophobic silica can be added to the powder. Domestic fumed silica 207 can be added to the sand grain powder to reduce the phenomenon of moisture absorption and powder dropping.
 
During the curing process of HAA, water molecules escape, and many pinholes easily appear on the surface of the coating film, which not only affects the appearance but also leads to the decline of water resistance and chemical resistance. If the defoamer 962 or degasser A4100 0.4% in the formula and the spraying thickness is less than 90μm, the above situation can be well improved.
 
The powder system made by HAA is prone to yellowing, which is mainly caused by two factors: first, it is caused by too much free amine residue during HAA purification or the common resin is not suitable for the HAA system; Secondly, it is caused by the introduction of excessive low purity benzoin. For the above situation, we can use a highly purified HAA curing agent, benzoin A400, and degassed 415 together; To make light-colored powder, an additional 0.5-1.0% antioxidant B900 can be added to improve the yellowing resistance of the coating.
 
In addition, HAA is a polar compound, which is difficult to disperse with pigments and fillers. Uneven dispersion easily leads to poor surface tension, which leads to pinholes or fog in the HAA powder system. Therefore, good dispersion and proper extrusion effect will have a great influence on the final surface properties and chemical resistance. The extrusion temperature is generally 115 ~ 125℃. At present, there are many HAA manufacturers on the market, and products with stable performance such as gloss, leveling, and yellowing are preferred.
 
 
 
Abstract：βHydroxyalkylamide,HAACuringAgentmanufacturer, supplier of KSCNT A3120 HAAA100 PCH-201, , PrimidCuringagentsupplier, supplier of ES-552 XL552 QM1260 SF4510
 
AAB industry technology chemical Co., Ltd is a professional TGIC HAA curing agent harder Crosslinking hardening agent manufacturer in China, 1, 3-TRIGLYCIDYL ISOCYANURATE supplier & manufacturer of rutile Tio2 titanium supplier China. To get more details about our HAA curing agent and related product please check our website:http://www.aabchemical.com/