Capsule manufacture
US4552811A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1984 |
| Grant date | Nov 12, 1985 |
| Priority date | — |
| Expiry date | Jun 12, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2985
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process is disclosed for performing encapsulation, en masse, by an in situ polymerization reaction to yield capsule wall material. The reaction comprises the polymerization of urea and formaldehyde, or monomeric or low molecular weight polymers of dimethylol urea or methylated dimethylol urea, melamine and formaldehyde, monomeric or low molecular weight polymers of methylol melamine or methylated methylol melamine, in an aqueous vehicle and the reaction is conducted in the presence of certain acrylic acid copolymers. The disclosed encapsulation process provides improved resistance of the emulsion of intended capsule core material to destabilization and permits the manufacture of microcapsules with improved drop size distribution, improved resistance to frictional smudge damage and enhanced impermeability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.