Microcapsules containing a gas-releasing photolabile compound and uses thereof
AssigneeFirmenich SA
InventorsAndreas Herrmann, Damien Berthier, Nicolas Paret, Alain Trachsel
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Abstract
The present invention relates to water-dispersible microcapsules that include an oil phase, e.g. a perfume, containing a photolabile compound capable of generating a gas upon exposure to light. The gas is able to cause an extension or the breaking of the microcapsule allowing the release of the oil phase and thus increasing the long-lastingness of the odor perception. The present invention concerns also the use of such microcapsules in perfumery as well as the perfuming compositions or perfumed articles that include such microcapsules therein to provide a prolonged release of fragrant molecules.
Claims21
A non-diffusive core-shell microcapsule comprising:
- a) a core comprising:
- an oil phase;
- at least one photolabile compound capable of generating, upon exposure to light at a wavelength comprised between 900 and 300 nm, a gas selected among the group consisting of C2-C4 alkenes;
- wherein the at least one photolabile compound comprises an alkyl aromatic ketone of formula:
- wherein each R1 represents, independently of each other, a hydrogen atom, a fluorine or chlorine atom, a hydroxyl or amino group or a C1-2 alkyl, C1-2 alkoxy, C1-2 dialkylamino or COR2′ group wherein R2′ represents a hydrogen atom or a C1-4 alkyl group, provided that at least two R1 represent a hydrogen atom;
- or two adjacent R1, when taken together, represent a OCH2O group, a OCH2CH2O group or a C3-4 alkanediyl group, optionally substituted with one to four methyl groups;
- and wherein R2 represents a propyl, n-butyl, or sec-butyl group;
- and
- optionally comprising at least one photo-catalyst;
- and
- b) a shell surrounding said core having a wall thickness of between 10 and 350 nm and being formed by interfacial polymerization or by a phase separation process induced by polymerization or by coacervation,
- wherein exposure of the microcapsule to light having a wavelength of between 900 and 300 nm generates a gas in the core that causes breakage of the shell to allow a greater release of the oil phase than microcapsules that do not contain the at least one photolabile compound.
A method of releasing a perfuming oil from a non-diffusive core-shell microcapsule, which comprises:
- providing the perfume oil in a microcapsule that has a core and shell surrounding the core, wherein the core comprises:
- at least one photolabile compound capable of generating, upon exposure to light at a wavelength comprised between 900 and 300 nm, a gas selected among the group consisting of C2-C4 alkenes, wherein the at least one photolabile compound comprises an alkyl aromatic ketone of formula:
- wherein each R1 represents, independently of each other, a hydrogen atom, a fluorine or chlorine atom, a hydroxyl or amino group or a C1-2 alkyl, C1-2 alkoxy, C1-2 dialkylamino or COR2′ group wherein R2 represents a hydrogen atom or a C1-4 alkyl group, provided that at least two R1 represent a hydrogen atom;
- or two adjacent R′, when taken together, represent a OCH2O group, a OCH2CH2O group or a C3-4 alkanediyl group, optionally substituted with one to four methyl groups;
- and wherein R2 represents a propyl, n-butyl, or sec-butyl group;
- and
- optionally, at least one photo-catalyst;
- forming the shell about the core with a wall thickness of between 10 and 350 nm by interfacial polymerization or by a phase separation process induced by polymerization or by coacervation, and
- exposing the microcapsule to light having a wavelength of between 900 and 300 nm to generate a gas in the core in an amount sufficient to cause breakage of the shell to allow a greater release of the perfume oil than microcapsules that do not contain the at least one photolabile compound.
Dependencies are inferred from the claim text.