| 摘要 |
The present disclosure provides a resin suitable for use in rotational molding having an environmental stress crack resistance of greater than 1000 hours. The resin has a density from 0.937 to 0.942 g/cm3, a melt index I2 determined according to ASTM D 1238 (2.16 kg/190° C.—I2) from 4.0 to 7.0 g/10 min, an I21 determined according to ASTM D 1238 (21.6 kg/190° C.—I21) from 160 to 200 g/10 min, an I21/I2 from 30 to 40 and a terminal vinyl unsaturation greater than 0.06, per 1000 carbon atoms; and a primary structure parameter (PSP2) of from 4 to 7, and an overall Mw/Mn from 2.7 to 3.5 comprising from 2 to 5 weight % of one or more C4-8 alpha olefin comonomers. |
| 主权项 |
1. A bimodal polyethylene composition having a density from about 0.935 to about 0.942 g/cm3, a melt index I2 determined according to ASTM D 1238 (2.16 kg 190° C.—I2) from about 4.0 to about 7.0 g/10 min, and I21 determined according to ASTM D 1238 (21.6 kg 190 C—I21) from about 150 to about 210 g/10 min, an I21/I2 from about 28 to about 40, a bent strip ESCR as determined by ASTM D 1693 in 100% octoxynol-9 for conditions A and B of greater than 1000 hours, a terminal vinyl unsaturation from about 0.07 to about 0.14 per 1000 carbon atoms, an overall Mw/Mn from about 2.8 to about 4.0, comprising from about 0.1 to about 8 weight % of one or more C4-8 alpha olefin comonomers, which when de-convoluted into two components consists of:
(i) from about 20 to about 45 weight % of a first component comprising one or more of C4-8 alpha olefin comonomers and the balance ethylene, said component having a density as determined according to ASTM D 792 from about 0.920 to about 0.930 g/cm3; a weight average molecular weight (Mw) from about 100,000 to about 180,000 g/mol and a polydispersity of less than 3; and (ii) from about 80 to about 55 weight % of a second component comprising one or more of C4-8 alpha olefin comonomers and the balance ethylene said component having a density as determined according to ASTM D 792 from about 0.945 to about 0.955 g/cm3, a weight average molecular weight (Mw) from about 15,000 to about 70,000, and a polydispersity of less than 3, wherein the difference in densities between components (i) and (ii) is less than 0.030 g/cm3. |
