▎ 摘　　要

NOVELTY - Phosphorus-based mixed flame retardant comprises (in weight parts) 2-hydroxyethylphenyl hypophosphorous acid (100), graphene-polyphosphazene nano-composite material (30-50), montmorillonite (10-15), sodium methyl silanolate (10-20) and cyclohexanol hexaphosphate (50-80). USE - Used as a phosphorus-based mixed flame retardant. ADVANTAGE - The flame retardant: comprises mutually matched and cooperative components, which overcome the defects of easy formation of molten droplets by the single phosphorus compound and its poor water resistance; and has simple preparation process, high heat stability and water resistance, and good flame retardance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the phosphorus-based mixed flame retardant, comprising: (a) grinding montmorillonite by ball milling method until the particle size is 20-50 nm to obtain nano-montmorillonite; (b) ultrasonically processing 2-hydroxyethylphenyl hypophosphorous acid, graphene-polyphosphazene nano-composite material and the nano-montmorillonite in cyclohexanol hexaphosphate at 30-40 degrees C for 2-4 hours; and (c) uniformly mixing with the other raw materials.