Capsule manufacture
US4444699A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 20, 1982 |
| Grant date | Apr 24, 1984 |
| Priority date | — |
| Expiry date | Apr 20, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2985
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process is disclosed for performing encapsulation, en masse, by an in situ polymerization reaction to yield capsule wall material. The polymerization comprises a reaction between melamine and formaldehyde and/or polycondensation of monomeric methylol melamine or etherified methylol melamine, or a low molecular weight polymer thereof, in an aqueous vehicle and the reaction is conducted in the presence of negatively-charged, carboxyl-substituted polyelectrolyte material and certain salts, both dissolved in the vehicle. The disclosed encapsulation process permits the manufacture of microcapsules with more impermeable walls and/or lower capsule batch viscosities.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.