Introduction: Magnesium hydroxide is a new type of filled flame retardant. It releases bound water when it is thermally decomposed and absorbs a large amount of latent heat to reduce the surface temperature of the synthetic material it fills in the flame. It has the ability to inhibit polymer decomposition and The role of cooling the generated combustible gas.

Magnesium hydroxide is a new type of filled flame retardant. It releases bound water when it is thermally decomposed and absorbs a large amount of latent heat to reduce the surface temperature of the synthetic material it fills in the flame. The generated combustible gas is used for cooling.

For a long time, Zhejiang magnesium hydroxide flame retardant has been a high-end product in my country, which is basically a blank. my country imports about 30,000 tons per year, mostly used by foreign-funded enterprises in China, mainly for high-end materials, such as communication equipment, insulation materials for high-speed rail, and wires and cables for nuclear power plants.

But now, this situation is being broken. With the efforts of Li Lijuan's team from Qinghai Salt Lake Institute, Chinese Academy of Sciences, Chinese researchers have successfully developed a domestic magnesium hydroxide flame retardant. Despite the twists and turns, the road to the industrialization of magnesium hydroxide flame retardants with independent intellectual property rights is gradually being rolled out.

Indispensable material

Magnesium oxide produced by thermal decomposition of magnesium hydroxide is a good refractory material and can also help improve the fire resistance of synthetic materials. At the same time, the water vapor released when it is decomposed also has a smoke suppression effect. Therefore, magnesium hydroxide is recognized as an excellent flame retardant with three functions of flame retardant, smoke suppression and filling in the rubber and plastic industry. At present, in the field of communication cables, foreign countries such as the United States, Japan, and the European Union consume more than 64% of inorganic flame retardants, while China only accounts for 8%.

"As an inorganic flame retardant, magnesium hydroxide is not only flame retardant but also capable of suppressing smoke. In a fire, more than 80% of the victims were not burned to death, but suffocated due to dense smoke. Once magnesium hydroxide was added to the flame retardant The fuel will greatly reduce the smoke density during combustion and reduce the risk of people being choked to death." Li Lijuan, a researcher at the Qinghai Salt Lake Institute of the Chinese Academy of Sciences, told the reporter of China Science News that the polymer material with magnesium hydroxide has the function of heat insulation. Burning it will form a film of magnesium oxide, which is resistant to high temperatures, can prevent further combustion, isolate the air from other combustibles, and improve people's chances of survival in the event of a fire.

"For high-end villas abroad, magnesium hydroxide must be added to the wall materials, which has a very good thermal insulation effect. Many airports and large supermarkets also use magnesium hydroxide flame-retardant materials on the roofs to keep them warm in winter and in summer. The amount used abroad is very high. However, this material is not used much in China at present." Li Lijuan said.

According to reports, the current raw materials used to extract magnesium hydroxide are mainly brucite ore. A large number of brucite mines in my country are mainly located in the Dandong area in the northeast, and the purity of magnesium hydroxide in the raw ore is only 95%, which can only be used as low-end flame retardants, such as materials for subway seats and carriages. "In high-end insulating materials, the purity of magnesium hydroxide must be more than 99% to meet the requirements. Take optical fiber as an example. The diameter of the fiber core and cladding are both micron poles, which are equivalent to human hair. There are high requirements for tensile strength and processing performance. Therefore, it is necessary to achieve strict control of the morphology, particle size and other parameters of the magnesium hydroxide flame retardant." Li Lijuan said.

What kind of product meets the requirements of high-end magnesium hydroxide flame retardant products? Simply put, only by achieving precise control of the five parameters of morphology, particle size, particle size, purity, and whiteness, can it be done High-end products that are comparable to imported products.

At present, the high-end magnesium hydroxide flame retardant market is still dominated by five manufacturers from the United States, Japan, and Israel. The value of each ton of products ranges from 24,000 yuan to 37,000 yuan. However, after years of hard work, researchers from the Qinghai Salt Lake Institute of the Chinese Academy of Sciences have successfully mastered the core process of preparing magnesium hydroxide flame retardants, and are gradually breaking the monopoly of high-end magnesium hydroxide flame retardants by foreign manufacturers.