04001140 is referenced by 162 patents and cites 4 patents.

A process is disclosed for performing encapsulation, en masse, by an in situ polymerization reaction to yield capsule wall material. The polymerization includes a reaction between urea and formaldehyde in an aqueous vehicle and the reaction is conducted in the presence of negatively-charged, carboxyl-substituted, linear aliphatic hydrocarbon polyelectrolyte material dissolved in the vehicle. Liquid-liquid phase separation is accomplished and maintained by increase in the molecular weight of the urea/formaldehyde reaction product without further dilution of the manufacturing vehicle. The negatively-charged polyelectrolyte material is required and has an apparent effect of controllng or modifying the polymerization reaction. The disclosed encapsulation process permits manufacture of microcapsules in concentrations of capsule to capsule manufacturing vehicle higher than previously possible.

Title
Capsule manufacture
Application Number
5/487322
Publication Number
4001140
Application Date
July 10, 1974
Publication Date
January 4, 1977
Inventor
Paul S Phillips Jr
Appleton
WI, US
Robert W Brown
Appleton
WI, US
Peter L Foris
Appleton
WI, US
Agent
E Frank McKinney
Assignee
NCR Corporation
OH, US
IPC
B01J 13/02
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