Among the many flame retardants, aluminum hydroxide is widely used due to its abundant structural water, acid resistance, flame retardancy, smoke suppression, good filling effect, no secondary pollution after combustion, and low cost. However, ordinary aluminum hydroxide starts to be dehydrated at 200°C, and is completely dehydrated at 330°C to 350°C. The curing of thermoplastic resins is mostly within the dehydration temperature range of aluminum hydroxide, which results in foaming in the synthetic resin product and uneven surface. The rate is low.
1% dehydration temperature is above 350℃, 500℃ dehydration reaches the peak value, EC<50μS/cm, strong dielectric property, solves the problem of product defects and reduced dielectric properties caused by low dehydration temperature of aluminum hydroxide, acid and alkali resistance Strong sex.
The flame retardancy is slightly lower than that of aluminum hydroxide, and more needs to be added to achieve the same flame retardancy. But its biggest feature is high heat resistance, thermal conductivity, acid and alkali resistance, and the production of high heat resistance functional materials can increase the added value of the product. The high heat-resistant boehmite flame retardant solves the problem of product defects and reduced dielectric properties caused by low dehydration temperature of aluminum hydroxide. (jwl)
Aluminum hydroxide flame retardant has the advantages of non-toxic, good stability, no toxic gas generated at high temperature, and can reduce the amount of smoke when plastic is burned, and has a low dehydration heat absorption temperature. Flame retardant polyolefin with 60% aluminum hydroxide can be used as building materials and interior decoration materials for automobiles and ships.
Aluminum hydroxide used as a flame retardant in the domestic and foreign markets is mainly a trihydrate and alumina (ATH), usually expressed as a-A120.3 H20. It is a crystalline or amorphous white powder. The crystal structure is composed of closely packed base ions in the form of AB double layers, and aluminum ions are among the above-mentioned stacked 9s base ions. All octahedral voids formed are empty. Therefore, the closely packed meridian ions constitute a layered structure, and two adjacent layers are connected by hydrogen bonds formed by the meridian ions.
The heat dehydration and phase change of aluminum hydroxide are very complicated. When aluminum hydroxide is used as a flame retardant, the quality index of aluminum hydroxide should be selected according to the thermal decomposition temperature of the polymer matrix material and the requirements of the molding processing temperature.
modified aluminum hydroxide flame retardant is one of the halogen-free flame retardants for synthetic materials. It has the three major functions of flame retardant, smoke suppression, and filling. It has no secondary pollution during combustion. It not only has good dispersion in polymers, but also is widely used in plastics and rubber products such as electricians, wires, cables, daily necessities, building materials, and transportation. in. (jwl)