Claims
- 1. A rotational molded article comprising a polymer composition having improved bond strength which in turn comprises:a. from 0.5 percent to less than 15 weight percent (by weight of the polymer blend) of a first polymer which is a homogeneous ethylene/α-olefin interpolymer having i. a melt index of from 0.1 to 100 grams/10 minutes, ii. a density of from 0.855 to 0.890 grams/centimeters3, and b. a second polymer which is an ethylene homopolymer or an ethylene/α-olefin interpolymer having i. a melt index of from 0.5 to 500 grams/10 minutes, and ii. a density which is at least 0.01 grams/centimeters3 greater than the density of the first polymer.
- 2. The rotational molded article of claim 1, wherein the melt index of the first polymer is from 0.5 to 5 grams/10 minutes.
- 3. The rotational molded article of claim 1, wherein the first polymer is an interpolymer of ethylene and at least one C3-C20 α-olefin.
- 4. The rotational molded article of claim 1, wherein the first polymer has a density of from 0.855 to 0.880 gram/centimeters3.
- 5. The rotational molded article of claim 1, wherein the first polymer is a substantially linear ethylene/α-olefin interpolymer having from 0.01 to 0.3 long chain branches/1000 carbons.
- 6. The rotational molded article of claim 1, wherein the first polymer is a substantially linear ethylene/α-olefin interpolymer characterized as having:a. a melt flow ratio (I10/I2)≧5.63, b. a molecular weight distribution, Mw/Mn, defined by the inequality: Mw/Mn≦(I10/I2)−4.63, and c. a critical shear rate at the onset of surface melt fracture which is at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear ethylene/α-olefin interpolymer having the same I2 and Mw/Mn.
- 7. The rotational molded article of claim 1, wherein the second polymer is a homogeneous ethylene polymer characterized as having:a. a molecular weight distribution, Mw/Mn which is from 1.5 to 3.0, and b. when the second polymer is an ethylene/α-olefin interpolymer, a CDBI of at least 50.
- 8. The rotational molded article of claim 1, wherein the second polymer is a substantially linear ethylene polymer characterized as having from 0.01 to 0.3 long chain branches/1000 carbons.
- 9. The rotational molded article of claim 1, wherein the second polymer is a substantially linear ethylene polymer characterized as having:a. a melt flow ratio (I10/I2)≧5.63, b. a molecular weight distribution, Mw/Mn, defined by the inequality: Mw/Mn≦(I10/I2)−4.63, and c. a critical shear rate at the onset of surface melt fracture which is at least 50 percent greater than the critical shear rate at the onset of surface melt fracture of a linear ethylene/α-olefin interpolymer having the same I2 and Mw/Mn.
- 10. The rotational molded article of claim 1, wherein the second polymer has a density that is at last 0.03 gram/centimeters3 greater than the density of the first polymer.
- 11. The rotational molded article of claim 1, wherein the second polymer has a density that is at least 0.05 gram/centimeters3 greater than the density of the first polymer.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of prior application Ser. No: 09/092,575, filed on Jun. 5, 1998 now U.S. Pat. No. 6,015,617.
This application claims priority from U.S. provisional application No. 60/050279 filed Jun. 20, 1997.
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Provisional Applications (1)
|
Number |
Date |
Country |
|
60/050279 |
Jun 1997 |
US |