Claims
- 1. A process for producing a resin suitable for use as utility conduit comprising polymerizing ethylene or copolymerizing ethylene and an alpha-olefin comonomer comprising 3 to 10 carbon atoms, in the presence of a chromium and titanium-based catalyst activated by:
(a) contacting said catalyst in a reactor at a temperature of between about 370-540° C. (700-1000° F.) with an atmosphere consisting essentially of an inert gas; and then (b) introducing an oxidant into said reactor so that the temperature of said reactor does not exceed about 510° C. (950° F.); and then (c) completing the activation of said catalyst in a reactor at a temperature of about 605-695° C. (1120-1280° F.) under an oxidizing atmosphere.
- 2. The process according to claim 1, wherein the temperature of said reactor in (a) does not exceed about 450° C. (850° F.).
- 3. The process according to claim 1, wherein the temperature of said reactor in (b) does not exceed about 450° C. (850° F.).
- 4. The process according to claim 1, wherein the temperature of said reactor in (a) does not exceed about 400° C. (750° F.) and the temperature of said reactor in (b) does not exceed about 425° C. (800° F.).
- 5. The process according to claim 1, wherein (c) further comprises completing the activation at said temperature and under said oxidizing atmosphere for a period of from 1 minute to 10 hours.
- 6. The process according to claim 5, wherein said period in (c) is from 4 to 7 hours.
- 7. The process according to claim 1, wherein said oxidizing atmosphere in (c) is an atmosphere consisting essentially of air.
- 8. The process according to claim 5, wherein said oxidizing atmosphere in (c) is an atmosphere consisting essentially of air.
- 9. The process according to claim 6, wherein said oxidizing atmosphere in (c) is an atmosphere consisting essentially of air.
- 10. The process according to claim 1, wherein said resin has a density of about 0.942-0.952 g/cm3 (ASTM D-4883), a range of MI2 of 0.15-0.45 g/10 min (ASTM D-1238), and ESCR>96 hours (ASTM D-1693, Condition B, F20, 10% Igepal).
- 11. A resin suitable for use as utility conduit, further characterized as comprising the residue of a chromium and titanium-based catalyst activated by:
(a) contacting said catalyst in a reactor at a temperature of between about 370-540° C. (700-1000° F.) with an atmosphere consisting essentially of an inert gas; and then (b) introducing an oxidant into said reactor so that the temperature of said reactor does not exceed about 510° C. (950° F.); and then (c) completing the activation of said catalyst in a reactor at a temperature of about 605-695° C. (1120-1280° F.) under an oxidizing atmosphere.
- 12. The resin according to claim 11, said resin having a density of about 0.942-0.952 g/cm3 (ASTM D-4883), a range of MI2 of 0.15-0.45 g/10 min (ASTM D-1238), and ESCR>96 hours (ASTM D-1693, Condition B, F20, 10% Igepal).
- 13. An article made by extruding the composition according to claim 11, said article having a hollow core.
- 14. The article according to claim 13, wherein said article comprises a resin having a density of about 0.942-0.952 g/cm3 (ASTM D-4883), a range of MI2 of 0.15-0.45 g/10 min (ASTM D-1238), and ESCR>96 hours (ASTM D-1693, Condition B, F20, 10% Igepal).
- 15. The article according to claim 13 further comprising a utility carrying electromagnetic energy within said hollow core.
Priority Claims (1)
Number |
Date |
Country |
Kind |
PCT/US03/98969 |
Mar 2003 |
WO |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of International Application No. PCT/US03/09869, filed Mar. 31, 2003, said application incorporated herein by reference.