Modification method of magnesium hydroxide with high coating ratio

Abstract

The invention relates to a method for modifying magnesium hydroxide with high coating ratio. Mainly comprise the following process steps: the magnesium hydroxide coarse powder is preliminarily crushed to the magnesium hydroxide raw material whose average particle size D50 is 3.5 ~ 4um; : 12 for rapid mixing, the surface modifier charge accounts for 2 to 3% of the magnesium hydroxide raw material mass percentage composition, and the temperature of reaction is controlled at 120° C., and the surface modifier is stearic acid; modified hydrogen The magnesium oxide semi-finished product is secondary crushed to superfine magnesium hydroxide with an average particle size D50 of 2.0um or less. The invention improves the coating rate of the modified superfine magnesium hydroxide powder and improves product activity; the invention improves the crushing production efficiency and reduces the production cost.

Description

technical field [0001] The invention belongs to the technical field of magnesium hydroxide modification methods, and in particular relates to a modification method of magnesium hydroxide with high coating ratio. Background technique [0002] Magnesium hydroxide is a new type of inorganic filled flame retardant. It releases bound water and absorbs a large amount of latent heat when it is thermally decomposed to reduce the surface temperature of the synthetic material it fills in the flame. It has the ability to inhibit polymer decomposition and The generated combustible gas is used for cooling, and has become an excellent flame retardant with triple functions of flame retardancy, smoke suppression and filling in the rubber and plastic industry. [0003] Due to the different surface properties of magnesium hydroxide powder and organic polymers (rubber, plastic, paint, etc.), the compatibility is poor. With the ultrafineness of magnesium hydroxide powder, the larger the specif...

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Problems solved by technology

[0004] However, when the superfine magnesium hydroxide is directly surface modified, due to the large specific surface area and high surface energy, it has a tendency to agglomerate to reduce its surface energy. Under the action of van der Waals force, the agglomeration between particles is caused.

However, this kind of agglomeration phenomenon is difficult to depolymerize in general modification equipment. If it cannot be depolymerized before modification, the surface modifier will be coated on the agglomerates, which cannot be evenly and effectively coated on the ultrafine powder. The surface of the body reduces the coating rate and affects the application performance of the ultrafine powder after surface modification

[0005] In addition, during the ultra-fine process of magnesium hydroxide, there will be a crushing equilibrium. Even if the crushing continues after reaching the balance, the particle size of the powder will not change or the change will be very small. In order to achieve the purpose of ultra-fine, blindly increase the crushing time. It causes a great waste of energy, and at the same time, the ultrafine powder is seriously agglomerated, which affects the coating rate after modification