Method of forming thermoplastic foams using nano-particles to control cell morphology
US8568632B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 26, 2003 |
| Grant date | Oct 29, 2013 |
| Priority date | — |
| Expiry date | Nov 26, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249986
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for making closed-cell, alkenyl aromatic polymer foams using nano-particle nucleation agents to control the cell morphology of the resulting foam includes forming a polymer melt at a temperature above the polymer glass transition temperature (for crystal polymers) or the polymer melt point (for amorphous polymers); incorporating selected nano-particles into the polymer melt; incorporating blowing agents into the polymer melt at an elevated pressure; optionally incorporating other additives, such as flame retardants, into the polymer melt; and extruding the polymer melt under conditions sufficient to produce a foam product having a desired cell morphology, characterized by parameters such as reduced average cell size range and/or increased asymmetry of the cells.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.