ABSTRACT
This chapter discusses controlled release (CR) technologies and summarizes the CR methods and applications uncovered in a search of the US patent literature for 1977 and part of 1978. The process comprises the dispersion of an organic phase containing isocyanate monomers into an aqueous phase. Spray drying involves the dispersion of the core material in a coating solution and atomizing the dispersion into hot air. The electrostatic encapsulation process is rather complex, and certain criteria must be met for the process to be feasible. The encapsulation process can also take place by condensation polymerization. Coating pans, sometimes called mushroom mixers, are one means of preparing glomules, tiny rolled-up balls of fine powders. Hydrogels are produced by the polymerization of hydrophilic monomers or by chemical modification of existing polymers. Gels are jellylike materials formed from the precipitation of sols, which are fluid colloidal solutions. The tables include patent number, company, title, application description, active agent, and CR method.
