Extrudable polyvinyl alcohol compositions containing thermoplastic polyethylene oxide
US5206278A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1991 |
| Grant date | Apr 27, 1993 |
| Priority date | — |
| Expiry date | Oct 18, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/10
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An extrudable polyvinyl alcohol composition useful for packaging and molding applications is prepared by melt blending polyvinyl alcohol and thermoplastic polyethylene oxide to provide a product which has improved pH stability and salt solution solubility. Useful extruded articles prepared from such compositions include films and containers. A method for extruding the polyvinyl alcohol composition comprises: PA0 adding sufficient energy to the polyvinyl alcohol composition to both melt it and essentially eliminate the polyvinyl alcohol crystallinity in the melt, and PA0 simultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the polyvinyl alcohol. The thermoplastic polyethylene oxide may be added to the polyvinyl alcohol before the polyvinyl alcohol is melted and its crystallinity eliminated or blended with the thus thermally treated polyvinyl alcohol and then melt extruding the polyvinyl alcohol/polyethylene oxide blend.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.