Method for preparing flame retardant magnesium hydroxide

Abstract

The invention relates to a method for preparing flame retardant magnesium hydroxide. The method is characterized by using undercalcined magnesia powders as raw materials, adding the undercalcined magnesia powders into water containing a composite dispersing agent, stirring and hydrating at a certain temperature for a certain time, and performing a hydrothermal crystallization in a pressure reaction kettle for a certain time. Flame retardant magnesium hydroxide powders with a high dispersibility can be obtained by filtering and drying materials which are subjected to the hydrothermal crystallization, and a filter liquor can be added with a proper amount of water and the dispersing agent to be recycled as water and the dispersing agent in the hydrating. By means of the method, the prepared flame retardant magnesium hydroxide is flaky with the high dispersibility, and the defects of a poor dispersibility, a large specific surface area, easy conglomeration and the like of common magnesium hydroxide in materials such as plastics or rubbers and the like are overcome. According to the method, the sources of required raw materials are rich, the used device and process are simple, and the production cost is low. The prepared flame retardant magnesium hydroxide with the high dispersibility can be widely applied to various industrial production processes.

Description

technical field [0001] The invention belongs to the field of inorganic materials, in particular to a preparation method of flame-retardant magnesium hydroxide. Background technique [0002] Magnesium hydroxide, an inorganic flame retardant, has a special layered structure and is an additive-type flame retardant with high smoke suppression. It has functions such as non-toxicity, smoke elimination, anti-drip, filling, and flame retardancy. Environmentally friendly inorganic flame retardants have become a hot spot for research and development in recent years. [0003] Ordinary magnesium hydroxide is generally produced by synthetic method at room temperature. In industry, it is usually reacted in water with brine, brine flakes or ore containing magnesium chloride and alkaline substances (such as sodium hydroxide, potassium hydroxide, calcium hydroxide and ammonia water, etc.) The resulting magnesium hydroxide is easy to agglomerate, and the product is difficult to filter and wa...

AI Technical Summary

Problems solved by technology

[0003] Ordinary magnesium hydroxide is generally produced by synthetic method at room temperature. In industry, it is usually reacted in water with brine, brine flakes or ore containing magnesium chloride and alkaline substances (such as sodium hydroxide, potassium hydroxide, calcium hydroxide and ammonia water, etc.) The resulting magnesium hydroxide is easy to agglomerate, and the product is difficult to filter and wash

The magnesium hydroxide that makes is mostly hexagonal or amorphous crystal, and its crystal has microscopic internal strain in direction, and crystal surface has positive charge, has hydrophilicity, and the affinity of lipophilic polymer molecule is not good enough, The crystal grains tend to be secondary agglomerated, which has the characteristics of large specific surface area and easy agglomeration between particles. It has poor dispersion and compatibility in materials such as plastic or rubber, so it is not suitable for use as a flame retardant material.

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