POLYMERIC POLYETHYLENE COMPOSITIONS AND TUBES MADE FROM SAID POLYMODAL POLYETHYLENE COMPOSITION Russian patent published in 2011 - IPC C08L23/08 C08F210/16 F16L9/12 B29C47/20 

FIELD: chemistry.

SUBSTANCE: composition contains at least a first polyethylene component and a second polyethylene component, each having molecular weight distribution equal or less than 5. Said polyethylene component has higher molecular weight than the second polyethylene component, and the value of parameter "a" is equal to or greater than approximately 0.35 when approximating with Carreau-Yasuda equation with n=0.

EFFECT: composition enables to obtain tubes with improved mechanical properties, such as resistance to slow cracking and fast crack propagation and strength which is sufficient to ensure the designation PE100.

14 cl, 1 dwg, 6 tbl, 5 ex