Method for encapsulating fine solid particles in the form of microcapsules
OwnerMichel Perrutinventor
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Abstract
The invention concerns a method for encapsulating fine solid particles in the form of microcapsules. Said method is characterised in that it comprises steps which consist in forming a suspension of said particles in a liquid consisting of at least a coating agent in intimate contact with a fluid having a pressure lower than its critical pressure, so as to saturate said suspension, spraying said fluid-saturated suspension through expansion means, and collecting the microcapsules in the gas stream resulting from decompression.
Claims11
Method for encapsulating fine solid particles in the form of microcapsules, characterized in that it comprises the steps consisting in:
- forming, in an enclosure (1), a suspension of these particles in a liquid constituted by at least one coating agent in intimate contact with a fluid at a pressure lower than its critical pressure so as to provoke saturation of said suspension with this fluid,
- spraying the fluid-saturated suspension through expansion means, and
- collecting the microcapsules in the gas stream resulting from decompression.
Method according to one of the preceding claims, characterized in that the fluid at subcritical pressure is constituted by carbon dioxide.
Method according to one of the preceding claims, characterized in that a continuous supply is ensured of the fluid at subcritical pressure and of the suspension of the active agent in the coating agent inside an enclosure (1) as well as a continuous drawing off of the products contained in this enclosure which are admitted into a spray nozzle (9) disposed in a collector recipient (11) maintained at a pressure close to atmospheric pressure.
Method according to any one of the preceding claims, characterized in that a lipid or a mixture of lipids is used as coating agent.
Method according to one of the preceding claims, characterized in that the placing in suspension of the particles is effected at a temperature of the order of 50° C. to 60° C. and at a pressure of the order of 5 Mpa to 6 Mpa and the pressure during the collection is close to atmospheric pressure.
Dependencies are inferred from the claim text.