Ultrafine Natural Ground Brucite

摘要

The invention provides particulate natural magnesium hydroxide (e.g. brucite) having a d₉₀ less than or equal to 6.2 mum, as measured by CILAS, and a particulate filler material for use in a polymeric composition, particularly but not exclusively a flame-retardant polymeric composition, the filler material comprising the particulate natural magnesium hydroxide and optionally one or more other particulate inorganic material (e.g. alumina trihydrate).