Microcellular foams, their method of production, and uses and products thereof
US6638984B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 2002 |
| Grant date | Oct 28, 2003 |
| Priority date | — |
| Expiry date | Sep 5, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2203/22
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention is directed to thermo-expandable microspheres and to the expanded microballoons, microcellular foam or foamed composite material that results upon heating the microspheres. The thermo-expandable microsphere of the present invention is characterized by having a polymeric wall surrounding one or more pockets or particles of blowing agent or propellant within the microsphere. The polymeric wall may have reactive functional groups on its surface to give a fusible microsphere. When the microspheres are heated, they expand to form microballoons comprising polymeric shells surrounding one or more internal gaseous voids, and when the microspheres are expanded while in contact with each other, a microcellular foam may be formed. The foam consists of a plurality of microballoons fused together, optionally aided by functional groups present on the surface of the heated microspheres that act to crosslink the material. When microspheres are mixed with a matrix, which can optionally react with functional groups on the microsphere surface, and the resulting combination is heated, the microspheres expand to give a foamed composite material in which the microballoons may be fu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.