HIGH VISCOSITY OIL IN WATER TYPE MICRO-EMULSION

摘要

An oil-in-water microemulsion of increased viscosity is disclosed, which microemulsion comprises an aqueous continuous phase, an oil phase, a primary surfactant having a lipophilic moiety and a hydrophilic moiety, wherein the hydrophilic moiety carries an electrostatic charge and a cosurfactant. The viscosity is increased by adding a secondary surfactant which is characterized by a long chain lipophilic moiety and a charged hydrophilic moiety which is reactive with the charged hydrophilic moiety of the primary surfactant. In forming the microemulsion of increased viscosity, the microemulsion is formed first in the absence of the secondary surfactant, and the secondary surfactant is added thereto.