Polymer composite for controlled release or membrane formation
US4898734A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 29, 1988 |
| Grant date | Feb 6, 1990 |
| Priority date | — |
| Expiry date | Feb 29, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01J13/025
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The present invention is a method to produce novel composites based on microcapsules or microspheres embedded in contiuous polymeric matrices. Both non-bioerodible and erodible polymers can be used. Material can be incorporated into the microcapsules or microspheres for subsequent release. In one embodiment of the present invention, spheres are homogeneously dispersed in a polymer matrix and then forced to release their contents by exposure to temperature, light or ultrasound. Alternatively, polymers which degrade as a function of time or hydrolysis can be used for controlled releases. The polymer composites have completely different properties from either a continuous polymer matrix or microcapsules or microspheres and are therefore useful for a wide variety of applications. When carbon tetrachloride is the incorporated material, the film is useful as a flame retarding device. When foaming agents are used, especially UV or heat sensitive materials, gas can be evolved inside each capsul The Government has rights in this invention pursuant to Grant Number 5-R01-GM26698 awarded by the Department of Health and Human Services.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.