Water-sensitive film containing thermoplastic polyurethane
US8147965B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 2008 |
| Grant date | Apr 3, 2012 |
| Priority date | — |
| Expiry date | Jan 15, 2031 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31935
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A film that contains a thermoplastic polyurethane and water-soluble polymer is provided. The film is both elastic and water-sensitive (e.g., water-soluble, water -dispersible, etc.) in that it loses its integrity over time in the presence of water. The dual attributes of elasticity and water-sensitivity may be achieved by reducing the tendency of the thermoplastic polyurethane and water-soluble polymer to form separate phases. Namely, phase separation may cause the elastomer to act as a barrier and limit the ability of the water-soluble polymer to contact water and thereby disperse. To minimize such phase separation, a variety of aspects of the film construction may be selectively controlled, such as the nature of the thermoplastic polyurethane and water-soluble polymer, the relative amount of each component, and so forth. For example, thermoplastic polyurethanes are polar in nature and thus may be generally compatible with water-soluble polymers (e.g., polyvinyl alcohol), which are also polar in nature. Further, water-soluble polymers having a relatively low molecular weight and viscosity typically possess better melt compatibility with polar thermoplastic polyurethanes. By carefu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.