Oily, free-flowing, microcapsules
US5071706A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 31, 1989 |
| Grant date | Dec 10, 1991 |
| Priority date | — |
| Expiry date | Aug 31, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2984
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
This disclosure is directed to the preparation of oily microcapsules which can be easily tray dried to a free flowing product without requiring special drying equipment. These microcapsules have a cell wall material having a first cell wall of gelatin/carboxymethylcellulose (CMC) which is prehardened (cross-linked) with a material selected from the group consisting of formaldehyde, glyoxal and glutaraldehyde to which there is grafted formaldehyde and urea. The predominant portion, viz., approximately 95% by wt. of these microcapsules have a particle size less than 1500 microns and more characteristically have a particle size ranging from about 100 to about 400 microns (microcapsular diameter). These microcapsules contain less than approximately 3 wt. % free oil and more characteristically less than about 1 wt. % free oil (non-microencapsulated oil) and have less free (unreacted) formaldehyde, which can be extracted with water, than do prior art microencapsulated oily materials. The microcapsules of this invention are granular and free-flowing when dried.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.