Microencapsulation process using melamine-formaldehyde and microcapsules produced thereby
US5204185A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 11, 1990 |
| Grant date | Apr 20, 1993 |
| Priority date | — |
| Expiry date | Dec 11, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2985
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for producing melamine-formaldehyde microcapsules using a reactive protective colloid is provided. The reactive protective colloid is prepared by reactively coupling a surface active polymer with a first melamine-formaldehyde pre-condensate. An aqueous solution which includes the reactive protective colloid and a second melamine-formaldehyde pre-condensate is then prepared. A substance to be encapsulated, preferably an oily solution containing a dyestuff precursor, is dispersed as droplets into the aqueous solution. The reactive protective colloid surrounds the droplets to form an emulsion. The second melamine-formaldehyde pre-condensate and the reactive protective colloid are made to self-condense to form melamine-formaldehyde microcapsule walls around the droplets of the substance to be encapsulated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.