| abstract |
Flame-retardant polymer composition consists of 20-60 wt.% thermoplastic, thermoset or thermosetting and/or elastomeric polymer and, as flame retardant, 40-80 wt.% aluminum (Al) hydroxide (A) or (B) with BET specific surface area (A) 3-5, (B) 5-8 m 2>/g, average particle diameter d 5 0 (A) 1.0-1.5, (B) 0.8-1.3 mu m, residual moisture content (A) 0.1-0.4, (B) 0.1-0.6%, oil number (A) 19-23, (B) 21-25% and water absorption (A) 0.4-0.6, (B) 0.6-0.8 ml/g. An independent claim is also included for production of flame retardant (A) or (B) from a filter-moist Al hydroxide with an average particle diameter of 0.8-1.5 mu m, produced by precipitation and filtration, by mill drying in a turbulent hot air stream until the BET surface area has increased by not less than 20% whilst largely maintaining the particle size distribution. |