Aluminum hydroxide, also known as hydrated alumina (A12O3 • 3H2O), is a recognized as the ideal inorganic flame retardant. It is reported that more than 80% of the inorganic flame retardants used in the world are aluminum hydroxide. Aluminum hydroxide is divided into two crystalline and amorphous, as the most used flame-retardant filler α-aluminum hydroxide, commonly used α-AI (OH) 3 said, also known as α-alumina trihydrate, Are produced by Bayer process or sintering: There are a lot of studies have reported that aluminum hydroxide is better used in polymer flame retardant materials. Aluminum hydroxide is a dry, lightweight powder that does not volatilize and exudes when it is used in polyolefins. It exhibits excellent resistance to arcing and diamagnetisation when subjected to electric arc and has good dispersibility in polyolefins , When the added amount is more, less prone to bending phenomenon; in the calender roller has a self-cleaning effect, to prevent adhesion, molding processing performance is good; Decomposition generated A12O3 can stop dripping, and promote carbonization, flame retardant effect. ATH is also a good smoke suppressant.
  Aluminum hydroxide as a flame retardant when used alone, the general flame retardant metal oxide efficiency is low, usually the amount of filling to be more than 40% to meet the actual requirements of flame-retardant, high dosage to be moderate flame retardancy. Aluminum hydroxide itself has a strong polarity, hydrophilic lipophilicity, especially with the particles of ultrafine, the powder easily reunion, and poor adhesion between the substrate, resulting in the processing of materials and mechanical properties decline. Therefore, when the added amount of aluminum hydroxide is high, the mechanical properties of the polymer material are degraded, and the processability is deteriorated. Improved method is to choose excellent surface modification agent, surface modification of aluminum hydroxide to improve its water temperature, which can withstand the processing temperature of plastics in general, to further broaden the range of application of aluminum hydroxide. Another approach is to increase the surface activity of the particles, improve dispersion, improve the compatibility of the particles with the polymeric materials, and improve the flame retardant and impact and thermal properties.
  Now commonly used modification methods are: (1) the use of stearic acid physical - chemical adsorption modification; (2) the use of titanate, aluminate and other coupling agents to modify its surface; (3) The use of alkyl phenolic resin, nitrile rubber surface modification of the surface in situ combinations.
  Nano-aluminum hydroxide can not only increase the flame retardant properties, and can improve the surface finish of polymer products and mechanical, electrical properties, enhance its resistance to leakage, arc and wear resistance, but also smoke and reduce the corrosive gas combustion materials The amount of production. In addition, combined with other flame retardant effect is more ideal, has broad application prospects.