Encapsulation method

A method for preparing solid capsules, comprising the following steps:

• a) adding with stirring a composition C1 comprising at least one compound A, in a liquid composition C2 comprising a thermo-expansible material,
• C1 and C2 not being miscible with each other,
• C2 being at temperature T2,
• whereby an emulsion is obtained comprising drops of composition C1 dispersed in the composition C2,
• b) addition with stirring of the emulsion obtained in step a) into a liquid composition C3 able to be polymerized,
• C3 and C2 not being miscible with each other,
• C3 being at temperature T3, preferably equal to T2,
• whereby an emulsion is obtained comprising drops dispersed in the composition C3,
• c) addition with stirring of the emulsion obtained in step b) in a liquid composition C4,
• C4 and C3 not being miscible with each other,
• C4 being at temperature T4 less than or equal to T2 and less than or equal to T3,
• whereby an emulsion is obtained comprising drops dispersed in the composition C4, and
• d) polymerization of the drops obtained in step c),
• whereby solid capsules are obtained, dispersed in the composition C4.