| 摘要 |
<p>A crosslinked polyethylene composition having excellent physical properties (e.g., a high stiffness, a high ESCR, and a high impact strength) and improved molding properties (e.g., an improved melt tension and an improved dye swell) is disclosed. This composition is obtained by lightly crosslinking and intimately melt blending a composition comprising high- and medium-density polyethylene (A) having a high molecular weight and high- and medium-density polyethylene 8 having a low molecular weight, wherein
<UnorderedLists id="ula01" listStyle="none"><ListItem>(i) the viscosity-average molecular weight of polyethylene (A) is 100,000 through 1,000,000. the viscosity-average molecular weight of polyethylene B is 1,000 through 100,000, and the ratio of the molecular weight of polyethylene (A) to that of polyethylene (B) is 2 through 100,</ListItem><ListItem>(ii) the blending ratio of polyethylene (A) to polyethylene (B) is 5:95 through 80:20, and</ListItem><ListItem>(iii) (MI), is 0.01 through 3.5, the ratio of the expansion factor α<Sub>2</Sub> to α<Sub>1</Sub> (α<Sub>2</Sub>/α<Sub>1</Sub>) is 1.1 through 10, and the ratio of (MI)<Sub>2</Sub> to (MI)<Sub>1</Sub> [(MI)<Sub>2</Sub>/(MI)<Sub>1</Sub>] is 0.03 through 0.9. wherein</ListItem><ListItem>(MI)<Sub>1</Sub> and (MI)<Sub>2</Sub> are melt indexes of the polyethylene compositions before and after crosslinking, respectively, and</ListItem><ListItem>α<Sub>1</Sub> and a<Sub>2</Sub> are expansion factors of the polyethylene compositions before and after crosslinking, respectively.</ListItem></UnorderedLists></p> |
