Claims
- 1. An extrusion coating process comprising; extrusion coating onto a substrate against a glossy chill roll, a low density polyethylene of narrow molecular weight distribution having a melt index of 2 to 4-dg/min at 190.degree. C., a swell ratio of 1.2 to 1.3, an annealed density of 0.92 to 0.93-g/cc, and a polydispersity index of 6 to 9.
- 2. The extrusion coating process according to claim 1 wherein the low density polyethylene has a melt index of 2.2 to 3-dg/min, a swell ratio of 1.25 to 1.27, an annealed density of 0.922 to 0.927-g/cc, and a polydispersity index of 6.0 to 7.8.
- 3. The process according to claim 2 wherein the low density polyethylene has a melt index of 2.5-dg/min, a swell ratio of 1.26, an annealed density of 0.926-g/cc, and a polydispersity index of about 7.
- 4. The process according to claim 1 wherein the glossy chill roll has a root mean square surface finish less than 10.
- 5. The process according to claim 4 wherein the glossy chill roll has a root mean square surface finish of at least 1, but no more than 6.
- 6. The process according to claim 5 wherein the glossy chill roll has a root mean square surface finish of no more than 2.
- 7. The process according to claim 1 wherein the glossy chill roll surface temperature is less than 20.degree. C., but higher than the environmental dew point of water.
- 8. The process according to claim 1 wherein the low density polyethylene is extruded at a temperature greater than 300.degree. C.
- 9. The process according to claim 1 further comprising oxidizing the resultant coated substrate under conditions sufficient to impart surface oxidation.
- 10. The process according to claim 9 wherein the oxidation is conducted by direct flame impingement, corona discharge, or ozone exposure.
- 11. The process according to claim 1 wherein the low density polyethylene is a low density polyethylene homopolymer.
Parent Case Info
This is a divisional application of copending application Ser. No. 07/843,043 filed Feb. 28, 1992, U.S. Pat. No. 5,268,230.
US Referenced Citations (9)
Divisions (1)
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Number |
Date |
Country |
Parent |
843043 |
Feb 1992 |
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