MAGNESIUM HYDROXIDE FIRE RETARDANT NANOPARTICLES AND METHOD FOR PRODUCTION THEREOF Russian patent published in 2015 - IPC C01F5/22 B82B3/00 B82Y99/00 C08K3/22 C09K21/02 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical engineering. The first step of producing magnesium hydroxide fire retardant nanoparticles includes reacting aqueous magnesium chloride solution with an alkaline component at temperature not higher than 100°C and molar ratio of OH^-: Mg⁺⁺ ions in the range of (1.9-2.1):1. The second step includes hydrothermal recrystallisation of the particles at temperature of 120-220°C, pressure of 0.18-2.3 MPa for 2-24 hours. The reaction mass is subjected to periodic hydraulic shocks with superheated steam at 160-240°C and pressure of 0.6-3.3 MPa. Magnesium hydroxide fire retardant nanoparticles are obtained, having a hexagonal lamellar structure and specific surface area of not more than 20 m²/g. The average diameter of secondary particles is not greater than 2 mcm. The diameter of 10% of the secondary particles is not greater than 0.8 mcm and the diameter o 90% of the secondary particles is not greater than 5 mcm. The longitudinal dimension of the secondary particles ranges from 150 to 900 nm and the thickness ranges from 15 to 150 nm. The nanoparticles can be surface-treated.

EFFECT: invention enables to achieve more uniform distribution of magnesium hydroxide fire retardant particles in polymer materials without deterioration of mechanical properties thereof and technological effectiveness of processing.

20 cl, 8 dwg, 1 tbl, 5 ex