High density polyethylene melt blends for improved stress crack resistance in pipe
US6822051B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 29, 2002 |
| Grant date | Nov 23, 2004 |
| Priority date | — |
| Expiry date | Dec 26, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1397
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The invention provides a polyethylene composition comprising a melt blend of (i) a bimodal high molecular weight high density polyethylene resin having a NCTL stress crack resistance of about 200 hours or greater, and (ii) a high density polyethylene resin selected from the group consisting of a homopolymer high density polyethylene resin, a copolymer high density polyethylene resin, and mixtures thereof, wherein the composition has a minimum NCTL stress crack resistance of 24 hours. In another embodiment, a polyethylene composition comprises a melt blend of the bimodal high molecular weight high density polyethylene resin and a linear low density polyethylene resin. The bimodal high molecular weight high density polyethylene resin can be a commodity film grade resin, the homopolymer and copolymer resins can be milk bottle grade and detergent bottle grade, respectively, and the linear low density polyethylene resin can be a film grade. The compositions are especially useful for manufacture of profile and corrugated pipe and/or pipe fitting applications, and chemical waste applications including sanitary sewer or irrigation piping systems.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.