METHOD OF PREPARING POLYSTYRENE GRANULATE CAPABLE OF FOAMING Russian patent published in 2010 - IPC C08J9/04 

FIELD: chemistry.

SUBSTANCE: invention describes a method of producing a polystyrene granulate capable of foaming, involving a step for feeding a foaming agent into a mixing zone, mixing the foaming agent with molten polystyrene, homogenisation of the obtained mixture, cooling it to extrusion temperature, extrusion and granulation under conditions which prevent foaming. The method is characterised by that molar ratio of the foaming agent being fed to the specific carrying capacity of the apparatus in the mixing zone (Ks), which is the ratio of the amount of the passing stream of molten material, including polystyrene in kg/h to stirring rate in rpm, is kept in the range between 0.08 and 0.23, while maintaining temperature difference between the input and output at the homogenisation and cooling step in the range between 30 and 70°C.

EFFECT: obtaining polystyrene granulate through a continuous method with a narrow grain-size composition, which enables to obtain foamed articles with range of apparent density values 10-40 kg/m³ which have satisfactory application properties.

3 cl, 1 tbl, 9 ex