Manufactured articles based on isotactic polypropylene having a highly oriented structure
US4931325A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 21, 1987 |
| Grant date | Jun 5, 1990 |
| Priority date | — |
| Expiry date | Dec 21, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31913
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
This invention relates to composite manufactured articles formed by a set of uniaxially oriented isotatic polypropylene films, having a resistance to delamination of at least 0.4 kg/cm are prepared by heating under pressure a plurality of isotatic polypropylene films superimposed to each other and separated from each other by a non oriented polypropylene films. The oriented films show an orientation of the crystalline phase such as to produce X-ray scattering angles .DELTA..times. equal to or lower than 10.degree.. The non oriented film show an orientation of the crystalline phase such as to produce X-ray scattering angles higher than 20.degree., at a temperature between a temperature equal to or higher than the melting temperature, measured in non restrain conditions, of the non oriented film and a temperature lower than the melting temperature, measured in restrained conditions, of the oriented films.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.