POLYMER MOULDING COMPOSITIONS Russian patent published in 2010 - IPC C08L23/06 C08L23/08 B29L31/56 

FIELD: chemistry.

SUBSTANCE: invention relates to polymer moulding compositions meant for moulding screw fitments. The composition contains a copolymer of ethylene and 1-hexene with density between 0.947 and 0.962 g/cm³ and melt index between 2 and 8 g/10 min and another copolymer of ethylene and 1-hexene with density between 0.912 and 0.932 g/cm³ and melt index between 0.25 and 6 g/10 min. Difference in density of the two polyethylenes is equal to or greater than 0.03 g/cm³. Selection of the components enables to obtain polymer compositions which have sufficient resistance to cracking and impact strength at low production expenses and without loss of other necessary operational properties.

EFFECT: screw fittings made from the said composition have strength which conforms to requirements for maintaining pressure, particularly in bottles with carbonated drinks, as well as plasticity for providing an airtight seal without need for lining and without change in taste or smell of the contents of the bottle.

9 cl, 4 ex, 6 tbl