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US 4,536,323 AGranted
Non-flammable aerosol propellant microemulsion system
AssigneeThe Drackett Company
InventorHoward R. Stopper
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AssigneeThe Drackett Company
InventorHoward R. Stopper
Estimating the term…
The amount of gaseous flammable propellants such as dimethylether, difluoroethane, propane, butane, and the like can be increased to as high as from 30 to 50% by weight of a propellant composition by dissolving the normally gaseous propellant in the dispersed oil phase of an oil-in-water microemulsion. The aerosol propellant compositions can be simply prepared by metering the ingredients other than the gaseous propellants into an aerosol dispenser, then adding the gaseous propellant, under suitable pressure, into the aerosol dispenser whereby simply shaking of the dispenser will result in the spontaneous formation of an oil-in-water microemulsion which is clear and stable and which can contain as much as about 50% by weight of the gaseous propellant without causing flaming when the composition is sprayed directly into a candle flame.
A propellant composition for aerosol dispensers capable of forming, at pressures suitable for delivering an aerosol from the aerosol dispenser, an oil-in-water microemulsion, said aerosol being characterized by its suppressed flammability, the composition comprising (a) a mixture comprising by weight of the total weight of the composition from about 23 to about 35% of a water-immiscible liquid which is a solvent for the propellant, from about 15 to about 25% water, and from about 3 to about 20% of a mixed surfactant system of at least one primary and at least one secondary surfactant, and (b) at least about 30% by weight of the total weight of the composition of at least one normally gaseous flammable aerosol propellant provided to pressurize the aerosol dispenser, the propellant being soluble in the water-immiscible liquid, said mixed surfactant system having a hydrophilic-lipophilic balance sufficient to cause the water-immiscible liquid in which the propellant is dissolved to disperse as micro-droplets in the water upon shaking of the aerosol dispenser, the micro-droplets being separated from the continuous water phase by the mixed surfactant system.
A method for preparing a propellant composition suitable for delivering an aerosol from an aerosol dispenser, said aerosol being characterized by its suppressed flammability, the method comprising the steps of filling an aerosol dispenser with a mixture comprising by weight of the total weight of the composition from about 23 to about 35% of a water-immiscible liquid which is a solvent for the propellant, from about 15 to about 25% water, and from about 3 to about 20% of a mixed surfactant system of at least one primary surfactant and at least one secondary surfactant, and pressurizing the aerosol dispenser with at least about 30% by weight of the total weight of the composition of at least one normally gaseous flammable propellant, whereby an oil-in-water microemulsion can be formed by shaking said aerosol dispenser, the at least one propellant being dissolved in the water-immiscible liquid to form micro-droplets constituting the dispersed oil phase, the micro-droplets being separated from the continuous water phase by the mixed surfactant system.
Dependencies are inferred from the claim text.