PARTICULATE CARBONATES AND THEIR PREPARATION AND USE IN THERMOPLASTIC FILM COMPOSITIONS

摘要

A method of producing a breathable film which comprises the steps of: (a) producing an inorganic filler by treating particles of an inorganic particulate material comprising an alkaline earth metal carbonate compound by reaction with a hydrophobising surface treatment agent comprising one or more aliphatic carboxylic acids having at least 10 chain carbon atoms to produce a hydrophobic coating on the particles under conditions such that the inorganic filler produced has a total surface moisture level comprising moisture adsorbed on the particles and trapped within the hydrophobic coating thereon of not greater than 0.1 % by weight based on the dry weight of the inorganic particulate material; (b) producing a filled thermoplastic composition by mixing the inorganic filler produced in step (a) with a heated thermoplastic polymer; and shaping the composition produced in step (b) by heat processing to form a film product.