Extrudable polyvinyl alcohol compositions containing thermoplastic polyurethane
US5028648A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 12, 1990 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Jul 12, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L75/04
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
An extruable polyvinyl alcohol composition useful for packaging and molding applications is prepared by melt blending polyvinyl alcohol and thermoplastic polyurethane to provide a product which has low water absorptivity, improved impact resistance, and improved low temperature/low humidity tensile properties. Useful extruded articles prepared from such compositions include films and bottles. 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 polyurethane may be added to the polyvinyl alcohol before the polyvinyl alcohol is melted and its crystallinity eliminated or blended with the thus treated polyvinyl alcohol and then melt extruding the polyvinyl alcohol/polyurethane blend.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.