BIODEGRADABLE GRANULAR POLYOLEFIN BLEND AND METHOD OF PRODUCTION Russian patent published in 2009 - IPC C08L23/02 C08L101/16 C08J3/22 C08L23/10 C08J3/20 

FIELD: chemistry.

SUBSTANCE: biodegradable granular polyolefin blend represents antimisting granules sized 2-8 mm of apparent bulk density 530-630 kg/m³, granule density less than 920-1300 kg/m³. Herewith melt flow index (MFI) of the parent polyolefin is MFI=2.5-25.0 g/10 minutes. Processing and relevant aid concentrate contains at least one biodegradable additive, thermostabilisers, antioxidants, lubricants, antistatic aids, pigments, fillers etc. The granular polymer blend is produced within a number of stages to ensure uniform distribution of all the aids in polyolefin. Four powder material flows are used. Three aid compositions are mixed with three parts of parent powder polyolefin in ratio 1:4, 1:3 and 1:2 respectively. Prepared concentrate mother stocks are supplied to the fourth combined mixer with residual part of polyolefin. If required, necessary liquid biodegradable additive. The blend is stirred and homogenised at 150-250°C.

EFFECT: underwater granulation and drying result in prepared antimisting and uncompressible sustained granular product characterised by good processing behaviour and performance attributes, easy-processed with the common equipment to make various products of controlled biodegradability.

3 cl, 5 tbl, 8 ex