Hollow polymer microcapsules and method of producing the same
US5955143A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1996 |
| Grant date | Sep 21, 1999 |
| Priority date | — |
| Expiry date | Dec 20, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2991
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Hollow polymer microcapsules are made by the method of dissolving a film-forming polymer in a volatile nonaqueous solvent; dispersing into the polymer solution finely divided particles of a volatilizable solid core material; inducing formation of a solid polymer coating on the particulate solid core material in the nonaqueous liquid mixture to produce polymer microcapsules having an encapsulated core of particulate core material; recovering the polymer microcapsules from the nonaqueous liquid mixture; and removing the encapsulated core material from the microcapsules to make hollow polymer microcapsules. Gas-filled polymer microcapsules that are made according to the method of this invention are useful in medical applications such as imaging contrast agents because they may be prepared to precisely controlled size specifications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.