Magnesium hydroxide is widely recognized as an excellent flame retardant in the rubber and plastic industry with triple functions of flame retardancy, smoke suppression, and filling. Widely used in rubber, chemical, building materials, plastics and electronics, unsaturated polyester, paint, coatings and other polymer materials. Especially for the coating cloth of mining air ducts, PVC core conveyor belts, flame-retardant aluminum-plastic panels, flame-retardant tarpaulins, PVC wire and cable materials, mining cable sheaths, and cable accessories, which can replace aluminum hydroxide and have excellent flame-retardant effects. Compared with similar inorganic flame retardants, magnesium hydroxide has better smoke suppression effect. Magnesium hydroxide has no harmful substance emissions during production, use, and disposal processes, and can also neutralize acidic and corrosive gases generated during combustion. When used alone, the dosage is generally between 40% and 60%.
Magnesium hydroxide decomposes and absorbs surface heat from combustion products to achieve flame retardancy when heated (340-490 degrees); At the same time, a large amount of water is released to dilute the oxygen on the surface of the fuel, and the active magnesium oxide generated by decomposition adheres to the surface of the fuel, further preventing combustion from occurring. Magnesium hydroxide not only does not produce any harmful substances during the entire flame retardant process, but its decomposition products can also absorb a large amount of harmful gases and smoke generated by the combustion of polymers such as rubber and plastic while flame retardant. Activated magnesium oxide continuously absorbs incomplete combustion residues, eliminating smoke and preventing droplets while quickly stopping combustion. It is an emerging environmentally friendly inorganic flame retardant. Classification
Flame retardants can be divided into two categories based on their chemical composition: organic flame retardants and inorganic flame retardants. Organic flame retardants are divided into two series: phosphorus based and halogen based. Due to the drawbacks of high toxicity and smoke from decomposition products, organic flame retardants are gradually being replaced by inorganic flame retardants.
The main varieties of inorganic flame retardants include aluminum hydroxide, magnesium hydroxide, red phosphorus, antimony oxide, tin oxide, molybdenum oxide, ammonium molybdate, zinc borate, etc. Among them, aluminum hydroxide and magnesium hydroxide have high heat absorption during decomposition and produce H2O, which can isolate the air. After decomposition, the oxide is a high-temperature resistant substance. Therefore, the two flame retardants can not only play a role in flame retardancy, but also play a filling role. They have the characteristics of not producing corrosive halogen gases and harmful gases, non-volatile, long-lasting effect, non-toxic, smoke-free, and non dripping.
At present, there is a large amount of aluminum hydroxide used in China, but with the increase of processing temperature of high polymers, aluminum hydroxide is prone to decomposition, reducing its flame retardant effect. Magnesium hydroxide has the following advantages over aluminum hydroxide:
1. The thermal decomposition temperature of magnesium hydroxide reaches 340 ℃, which is 100 ℃ higher than that of aluminum hydroxide. This is beneficial for increasing the processing temperature of plastics, accelerating the extrusion speed, improving the plasticizing effect, shortening the molding time, and achieving high surface glossiness of the product without surface defects. At the same time, it ensures super strong peel strength.
2. Uniform particle size distribution, good compatibility with the substrate, and minimal impact on the mechanical properties of the product.
3. The magnesium oxide generated after the combustion and dehydration of magnesium hydroxide is a high-strength and heat-resistant material that can be used as a protective wall to isolate fire sources and toxic and harmful gases. Magnesium hydroxide has strong neutralization ability with acid and can quickly neutralize acidic gases such as SO2, NOx, CO2 produced during the combustion process of plastics.
4. Magnesium hydroxide has high decomposition ability, high flame retardant efficiency, strong smoke suppression ability, low hardness, low friction on equipment, and helps to extend equipment life.
5. Low price, magnesium hydroxide is half the price of aluminum hydroxide, with a large filling amount, which can greatly reduce the cost of the product.
