Foam core imaging element with gradient density core
US7585557B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 2004 |
| Grant date | Sep 8, 2009 |
| Priority date | — |
| Expiry date | Aug 31, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249993
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The invention relates to a base comprising a closed cell foam core sheet having a closed cell foam layer with a density gradient between the center of the core and the surfaces of the core. The invention also relates to a method of making such a base by adding a first concentration of a first blowing agent to a first polymer to form a first mixture, adding a second concentration of a second blowing agent to a second polymer to form a second mixture, and extruding the mixtures to form the closed cell foam core sheet. The invention also relates to a method of making such a closed cell foam core sheet base comprising the steps of adding a blowing agent to a polymer to form a mixture, melting the mixture, extruding the mixture from a die, and rapidly quenching the mixture against a high heat transfer surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.