Microcapsules containing a gas-generating photolabile ketoacid or ketoester and uses thereof
09738859 · 2017-08-22
Assignee
Inventors
- Andreas Herrmann (Geneva, CH)
- Damien Berthier (Geneva, CH)
- Nicolas Paret (Geneva, CH)
- Alain Trachsel (Geneva, CH)
Cpc classification
A61K2800/56
HUMAN NECESSITIES
C11D17/0039
CHEMISTRY; METALLURGY
C11D3/505
CHEMISTRY; METALLURGY
C11D3/507
CHEMISTRY; METALLURGY
International classification
C11D17/00
CHEMISTRY; METALLURGY
A61Q13/00
HUMAN NECESSITIES
Abstract
The present invention relates to water-dispersable microcapsules comprising an oil phase, e.g. a perfume, containing a photolabile α-ketoacid or α-ketoester 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 said microcapsules in perfumery as well as the perfuming compositions or perfumed articles comprising the invention's microcapsules to provide a prolonged release of fragrant molecules.
Claims
1. A non-diffusive microcapsule comprising; A. a core comprising: an oil phase; at least one photolabile α-ketoacid or α-ketoester capable of generating, upon exposure to light a gas of CO or CO.sub.2 and being of formula ##STR00004## wherein R.sup.1 represents: i) a C.sub.1-16 hydrocarbon group optionally comprising one to four oxygen, sulphur or nitrogen atoms, provided that no heteroatom is directly connected to the CO group; or ii) a group of formula R.sup.1′(CO—COOR.sup.2).sub.n wherein R.sup.2 has the same meaning as below and R.sup.1′ is a C.sub.2-10 hydrocarbon group, optionally comprising one or two oxygen or nitrogen atoms, provided that no heteroatom is directly connected to the CO group, wherein R.sup.1′ is linked to the keto functional group of the α-ketoacid or α-ketoester and wherein n is an integer comprised between 1 and 4; and wherein R.sup.2 represents either a hydrogen atom or an alkaline metal ion, or a primary or secondary group which is: a) a C.sub.1-4 hydrocarbon group optionally comprising one or two oxygen or nitrogen atoms; or b) a C.sub.5-22 hydrocarbon group optionally comprising one to ten oxygen atoms or one to two nitrogen atoms; provided that said C.sub.5-22 hydrocarbon group is such as that the corresponding aldehyde or ketone of the O—R.sup.2 moiety is an odorless compound; or c) a group of formula R.sup.2′(OOC—CO—R.sup.1), wherein R.sup.1 has the same meaning as above and R.sup.2′ is a C.sub.2-12 hydrocarbon group optionally comprising one to six oxygen atoms and wherein R.sup.2′ is linked to the ester functional group of the α-ketoester, and wherein n is an integer comprised between 1 and 4; provided that at least one of R.sup.1 or R.sup.2 is a group as defined in i) or a) or b) respectively; and optionally comprising at least one photo-catalyst; and B. a shell surrounding said core formed by interfacial polymerization or by a phase separation process induced by polymerization or by coacervation; wherein the amount of gas generated upon exposure to light is sufficient to expand and break the shell to release the oil from the capsule.
2. A microcapsule according to claim 1, characterized in that it comprises, based on the total microcapsule weight, from about 20% to about 96% of oil phase.
3. A microcapsule according to claim 1, characterized in that R.sup.1 represents: i) a C.sub.1-10 hydrocarbon group optionally comprising one or two oxygen, sulphur or nitrogen atoms, provided that no heteroatom is directly connected to the CO group; or ii) a group of formula R.sup.1′(CO—COOR.sup.2).sub.n wherein R.sup.2 has the meaning set in claim 1; R.sup.1′ is a C.sub.2-6 hydrocarbon group and n is equal to 1 or 2.
4. A microcapsule according to claim 1, characterized in that R.sup.2 represents a hydrogen atom or a primary or secondary group which is: a) a C.sub.2-4 hydrocarbon group optionally comprising one or two oxygen or nitrogen atoms; or b) a C.sub.5-16 hydrocarbon group optionally comprising one to seven oxygen atoms or one or two nitrogen atoms; provided that said C.sub.5-16 hydrocarbon group is such as that the corresponding aldehyde or ketone of the O—R.sup.2 moiety is an odorless compound; or c) a group of formula R.sup.2′(OOC—CO—R.sup.1).sub.n wherein R.sup.1 has the meaning set in claim 1 and R.sup.2′ is a C.sub.2-6 hydrocarbon group optionally comprising one or two oxygen atoms and n is equal to 1 or 2.
5. A microcapsule according to claim 1, characterized in that said α-ketoacid or α-ketoester generates a gas upon exposure to light at a wavelength comprised between 450 and 320 nm.
6. A microcapsule according to claim 1, characterized in that it comprises, based on the total microcapsule weight, from 10% to 50% of photolabile α-ketoacid or α-ketoester.
7. A microcapsule according to claim 1, characterized in that the shell surrounding said core is an aminoplast, polyamide, polyester, polyurea or polyurethane resin or a mixture thereof.
8. A microcapsule according to claim 1, characterized in that said shell has a thickness varying between 20 and 500 nm.
9. A microcapsule according to claim 1, characterized in that the oil phase comprises a perfuming oil.
10. A perfuming consumer product comprising: i) as perfuming ingredient, at least one microcapsule as defined in claim 9; and ii) as an option a free perfume oil.
11. A perfuming consumer product according to claim 10, characterized in that the consumer product is a perfume, a fabric care product, a body-care product, an air care product or a home care product.
12. A perfuming consumer product according to claim 10, characterized in that the consumer product is a fine perfume, a cologne, an after-shave lotion, a liquid or solid detergent, a fabric softener, a fabric refresher, an ironing water, a paper, a bleach, a shampoo, a coloring preparation, a hair spray, a vanishing cream, a deodorant or antiperspirant, a perfumed soap, shower or bath mousse, oil or gel, a hygiene product, an air freshener, a “ready to use” powdered air freshener, a wipe, a dish detergent or hard-surface detergent.
13. A method to release a perfume from a microcapsule as defined in claim 9, characterized in that said microcapsule is exposed to conditions allowing the degradation of the photolabile α-ketoacid or α-ketoester of formula (I) with concomitant formation of a gas at a rate above 8.0×10.sup.−5 s.sup.−1 in order to break the shell to release the oil from the capsule.
14. A method to release a perfume from a microcapsule as defined in claim 9, characterized in that said microcapsule is exposed to conditions allowing the degradation of the photolabile α-ketoacid or α-ketoester of formula (I) with concomitant formation of a gas at a rate above 1.0×10.sup.−4 s.sup.−1 in order to break the shell to release the oil from the capsule.
15. A non-diffusive microcapsule comprising: A. a core comprising: an oil phase; at least one photolabile α-ketoacid or α-ketoester capable of generating, upon exposure to light a gas of CO or CO.sub.2 and being of formula ##STR00005## wherein R.sup.1 represents: i) a C.sub.1-16 hydrocarbon group optionally comprising one to four oxygen, sulphur or nitrogen atoms, provided that no heteroatom is directly connected to the CO group; or ii) a group of formula R.sup.1′(CO—COOR.sup.2).sub.n wherein R.sup.2 has the same meaning as below and R.sup.1′ is a C.sub.2-10 hydrocarbon group, optionally comprising one or two oxygen or nitrogen atoms, provided that no heteroatom is directly connected to the CO group, wherein R.sup.1′ is linked to the keto functional group of the α-ketoacid or α-ketoester and wherein n is an integer comprised between 1 and 4; and wherein R.sup.2 represents either a hydrogen atom or an alkaline metal ion, or a primary or secondary group which is: a) a C.sub.1-4 hydrocarbon group optionally comprising one or two oxygen or nitrogen atoms; or b) a C.sub.5-22 hydrocarbon group optionally comprising one to ten oxygen atoms or one to two nitrogen atoms; provided that said C.sub.5-22 hydrocarbon group is such as that the corresponding aldehyde or ketone of the O—R.sup.2 moiety is an odorless compound; or c) a group of formula R.sup.2′(OOC—CO—R.sup.1), wherein R.sup.1 has the same meaning as above and R.sup.2′ is a C.sub.2-12 hydrocarbon group optionally comprising one to six oxygen atoms and wherein R.sup.2′ is linked to the ester functional group of the α-ketoester, and wherein n is an integer comprised between 1 and 4; provided that at least one of R.sup.1 or R.sup.2 is a group as defined in i) or a) or b) respectively; and from 1% to 20% of at least one photo-catalyst based on the total microcapsule weight; and B. a shell surrounding said core formed by interfacial polymerization or by a phase separation process induced by polymerization or by coacervation.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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(8) The invention is now going to be illustrated by examples which should not be understood as limitative of the invention.
EXAMPLES
(9) The invention is hereafter described in more detailed manner by way of the following examples, wherein the abbreviations have the usual meaning in the art, temperatures are indicated in degrees centigrade (° C.). NMR spectral data were recorded in CDCl.sub.3 (if not stated otherwise) on a Bruker AMX 400 or 500 spectrometer in CDCl.sub.3 at 400 or 500 MHz for .sup.1H and at 100.6 or 125.8 MHz for .sup.13C, the chemical displacements 6 are indicated in ppm with respect to Si(CH.sub.3).sub.4 as the standard, the coupling constants J are expressed in Hz (br.=broad peak). High performance liquid chromatography (HPLC) analyses were carried out on a Thermo Separation Products apparatus composed of a SpectraSystem SCM1000 online vacuum degasser, a SpectraSystem P4000 quaternary pump, a SpectraSystem AS3000 autosampler and a SpectraSystem UV6000LP diode array detector. Samples (10 μL) were eluted at 1 mL/min on a Macherey-Nagel Nucleosil® 120-5 C4 column (250×4 mm i.d.) with a gradient of water/acetonitrile (both containing 0.1% of trifluoroacetic acid) varying from 1:1 to 1:4 (during 5 min) and analyzed at 254 nm. Gas chromatography (GC) analyses were carried out on an Agilent Technologies 7890A GC System equipped with an Agilent Technologies 7683B Series Injector and a FID detector. Samples (5 μL, split ratio 50:1) were eluted at 2.4 mL/min with helium on an Agilent HP-5 capillary column (30 m, 0.32 mm i.d., film 0.25 μm) at 60° C. for 1 min, then to 200° C. at 20° C./min; the injector temperature was at 250° C., the detector temperature at 280° C. Commercially available reagents and solvents were used without further purification if not stated otherwise. Reactions were carried out in standard glassware under N.sub.2.
(10) Although specific conformations or configurations are indicated for some of the compounds, this is not meant to limit the use of these compounds to the isomers described. According to the invention, all possible conformation or configuration isomers are expected to have a similar effect.
Example 1
Preparation of α-Ketoesters Capable of Generating a Gas Upon Exposure to Light
Preparation of isopropyl 2-oxo-2-phenylacetate
(11) A solution of 2-oxo-2-phenylacetic acid (16.21 g, 108 mmol), N,N-dimethylpyridin-4-amine (DMAP) (1.32 g, 10.8 mmol) and propan-2-ol (14.75 mL, 193.0 mmol) in dichloromethane (120 mL) was cooled on an ice-bath before a solution of N,N′-methanediylidenedicyclohexanamine (DCC) (26.41 g, 128.0 mmol) in dichloromethane (90 mL) was added during 1.5 h. The reaction mixture was stirred for 30 min at 0° C., then at 20° C. for 29 h. The precipitate formed in the reaction was filtered off and the filtrate taken up in ether, washed with water (3×), HCl 10%, (3×), and a saturated solution of Na.sub.2CO.sub.3 (2×). The organic layer was dried (Na.sub.2SO.sub.4) and concentrated. Column chromatography (SiO.sub.2, heptane/ether 4:1) gave 17.40 g (84%) of a slightly yellow oil.
(12) .sup.1H-NMR (400 MHz): δ 8.02-7.97 (m, 2H); 7.68-7.62 (m, 1H); 7.55-7.48 (m, 2H); 5.33 (hept., J=6.3, 1 H); 1.41 (d, J=6.4, 6 H).
(13) .sup.13C-NMR (100.6 MHz): δ 186.72 (s); 163.66 (s); 134.80 (d); 132.58 (s); 129.96 (d); 128.89 (d); 70.67 (d); 21.74 (q).
Preparation of ethyl 2-oxo-2-(p-tolyl)acetate
(14) Aluminum trichloride (14.47 g, 109 mmol) was suspended in dichloromethane (60 mL) at 0° C. before ethyl 2-chloro-2-oxoacetate (12.1 mL, 109 mmol) was added dropwise during 45 min. After stirring for 10 min, toluene (11.6 mL, 109 mmol) was added during 30 min and the mixture left warming to room temperature. After stirring for 1.5 h, the mixture was poured onto crushed ice (300 g) and concentrated hydrochloric acid (100 mL) and extracted with cyclohexane (100 mL). The organic layer was washed with sodium hydroxide (0.1 N, 100 mL) and a saturated aqueous solution of NaCl (2×80 mL), dried (MgSO.sub.4) and concentrated to give 22.25 g of a yellow oil, still containing toluene.
(15) .sup.1H-NMR (500 MHz): δ 7.90 (d, J=8.3, 2H); 7.29 (d, J=8.0, 2H); 4.43 (q, J=7.2, 2H); 2.42 (s, 3H); 1.40 (t, J=7.1, 3H).
(16) .sup.13C-NMR (125.8 MHz): δ 186.11 (s); 164.07 (s); 146.22 (s); 130.16 (d); 130.08 (s); 129.63 (d); 62.20 (7); 21.89 (q); 14.12 (q).
Preparation of ethane-1,2-diyl bis(2-oxo-2-phenylacetate)
(17) A solution of 2-oxo-2-phenylacetic acid (14.50 g, 96.5 mmol), DMAP (6.30 g, 51.5 mmol) and ethylene glycol (4.00 g, 64.4 mmol) in dichloromethane (75 mL) was cooled on an ice-bath before a solution of DCC (14.60 g, 71.0 mmol) in dichloromethane (50 mL) was added. Then more 2-oxo-2-phenylacetic acid (14.50 g, 96.5 mmol) in dichloromethane (20 mL), DMAP (6.30 g, 51.5 mmol) in dichloromethane (20 mL) and DCC (14.60 g, 71.0 mmol) in dichloromethane (35 mL) was added. The reaction mixture was left warming to room temperature and stirred for 6 h. The precipitate formed in the reaction was filtered off and washed with dichloromethane. The filtrate was washed with HCl 10%, (2×), a saturated solution of Na.sub.2CO.sub.3 (2×) and a saturated solution of NaCl (2×). The organic layer was dried (Na.sub.2SO.sub.4) and concentrated to give 18.80 g of the crude product. Column chromatography of 9.40 g (SiO.sub.2, heptane/ethyl acetate 1:1) gave 7.16 g (89%) of a white solid.
(18) .sup.1H-NMR (400 MHz): δ 8.03-7.97 (m, 4H); 7.67-7.61 (m, 2H); 7.52-7.45 (m, 4H); 4.74 (s, 4H).
(19) .sup.13C-NMR (100.6 MHz): δ 185.55 (s); 163.26 (s); 135.13 (d); 132.19 (s); 130.10 (d); 128.99 (d); 62.99 (t).
Preparation of ethyl 2-oxopentanoate
(20) A solution of 2-oxopentanoic acid (3.00 g, 25.8 mmol), ethanol (1.20 g, 25.8 mmol) and DMAP (0.32 g, 2.6 mmol) in dichloromethane (30 mL) was cooled with an ice bath before a solution of DCC (5.86 g, 28.4 mmol) in dichloromethane (15 mL) was added dropwise during 30 min. The reaction mixture was stirred for 10 min at 0° C., then at room temperature for 3 h. The precipitate formed during the reaction was filtered on a sintered glass frit and rinsed with dichloromethane (15 mL). The filtrate was concentrated under reduced pressure (40° C.) and the residue taken up in diethylether (100 mL). The organic phase was washed with water (3×30 mL), an aqueous solution of HCl (10%, 3×30 mL), water (30 mL), a saturated aqueous solution of NaHCO3 (3×30 mL) and water (30 mL). The aqueous phases were re-extracted with diethylether (100 mL). The combined organic phases were dried (Na.sub.2SO.sub.4) and concentrated under reduced pressure (45° C.). Bulb-to-bulb distillation (120° C., 8 mbar) gave 1.80 (45%) g of a colorless oil.
(21) .sup.1H-NMR (500 MHz): δ 4.32 (q, J=7.2, 2H), 2.82 (t, J=7.2, 2H), 1.67 (hex., J=7.4, 2H), 1.37 (t, J=7.2, 3H), 0.97 (t, J=7.5, 3H).
(22) .sup.13C-NMR (125.8 MHz): δ 194.67 (s), 161.32 (s), 62.35 (t), 41.14 (t), 16.54 (t), 14.03 (q), 13.52 (q).
Example 2
Degradation of α-Ketoacids and α-Ketoesters Capable of Generating a Gas Upon Exposure to Light
(23) α-Ketoacids or α-ketoesters according to the invention (0.08 mmol) were dissolved in acetonitrile (10 mL). The solutions (5 mL) were placed in a Pyrex® glass cell thermostatted at 25° C. (±1° C.) and exposed to UVA-light with a Sanalux SAN-40 lamp (origin: Sanalux GmbH) with 3.1 mW/cm.sup.2 (at distance of ca. 15 cm from the lamp) for 120 min. The degradation of the compound was followed by HPLC and/or GC analysis (see above) at constant time intervals. Before irradiation (t.sub.0) a first aliquot of the solution (50 μL) was pipetted off, diluted with acetonitrile (950 μL for HPLC analysis, 50 μL for GC analysis) and analyzed. Then the lamp was switched on, and further aliquots of the solutions were pipetted off (every 10 min during 2 h), diluted and analyzed as described above.
(24) Observed first-order rate constants (k.sub.obs) were obtained according to Equation 1 by plotting the negative natural logarithm of the (decreasing) peak areas measured at time t (A.sub.t) over the one measured at time t.sub.0 (A.sub.0) against time.
A.sub.t=A.sub.0e(−k.sub.obst) (Eq. 1)
Linear regression gave straight lines with good correlation coefficients (r.sup.2). The measured rate constants are listed in Table 1.
(25) TABLE-US-00001 TABLE 1 Observed first-order rate constants (k.sub.obs) for the degradation of α-ketoacids and α-ketoesters according to the invention upon exposure to UVA-light (3.1 mW/cm.sup.2) in acetonitrile at 25° C. (average data of at least two measurements). α-Ketoacid or α-ketoester k.sub.obs [s.sup.−1] Method 2-Oxo-2-phenylacetic acid (origin: Alfa Aesar) 2.87 × 10.sup.−4 HPLC Ethyl 2-oxo-2-phenylacetate (origin: Aldrich) 7.87 × 10.sup.−4 HPLC Isopropyl 2-oxo-2-phenylacetate 7.20 × 10.sup.−4 HPLC Ethyl 2-oxo-2-(p-tolyl)acetate 4.11 × 10.sup.−4 HPLC Ethane-1,2-diyl bis(2-oxo-2-phenylacetate) 5.57 × 10.sup.−4 HPLC Ethyl 2-oxopropanoate (origin: Acros) 1.91 × 10.sup.−4 GC Ethyl 2-oxopentanoate 2.03 × 10.sup.−4 GC Ethyl (±)-3-methyl-2-oxopentanoate 3.10 × 10.sup.−4 GC (origin: Firmenich SA)
Example 3
Preparation of Microcapsules According to the Present Invention Containing a Photolabile α-Ketoacid or α-Ketoester Capable of Generating a Gas Upon Exposure to Light and a Fragrance Molecule as the Oil Phase
(26) General Protocol for the Preparation of Polyurea Microcapsules of the Present Invention Containing a Photolabile α-Ketoacid or α-Ketoester:
(27) In a beaker, a polyisocyanate (Desmodur® N100, Biuret of hexamethylene diisocyanate, origin: Bayer AG or Takenate® D-110N, Trimethylol propane-adduct of xylylene diisocyanate, origin Mitsui Chemicals) and the invention's photolabile α-ketoester were dissolved in the perfume oil (origin: Firmenich SA). The oil phase composed of the photolabile α-ketoester and the perfume oil was added to a solution of poly(vinyl alcohol) (PVOH) 18-88 (circa 0.42 g, origin: Aldrich) at 1 wt % in water (circa 42 mL). An emulsion was prepared by Ultra-Turrax stirring (model S25N 10G) between 15'000 and 24'000 rpm for 2 min. The droplet size was controlled by light microscopy. The emulsion was then introduced at room temperature into a 250 mL reactor and stirred with an anchor at 350 rpm. A solution of guanidine carbonate (origin: Aldrich) or guanazole (1H-1,2,4-Triazole-3,5-diamine, origin: Alfa Aesar) in water (circa 5 mL) was added dropwise to the emulsion for 1 h. The reaction mixture was heated from room temperature to 70° C. during 1 h at the pH indicated below, then kept at 70° C. for 2 h, and finally cooled to room temperature to afford a white dispersion. Respective quantities are reported below.
a) Preparation of Microcapsules a According to the General Protocol
(28) Microcapsules A were prepared with Desmodur® N100, ethyl 2-oxo-2-phenylacetate, 4-tert-butylcyclohexyl acetate (origin: Firmenich SA) and guanidine carbonate at pH 10.5.
(29) TABLE-US-00002 TABLE 2 Composition of Microcapsules A Product Quantity (g) Desmodur ® N100 (a polyisocyanate) 1.17 Ethyl 2-oxo-2-phenylacetate (a photolabile α-ketoester) 14.00 4-tert-Butylcyclohexyl acetate (a perfume oil) 3.52 PVOH 18-88 0.50 Guanidine carbonate (a polyamine) 0.4 Water 51.50 Perfume oil/Photolabile compound ratio 0.25 Shell/Oil phase ratio 0.09
b) Preparation of Microcapsules B to J According to the General Protocol
(30) Microcapsules B-J were prepared with Takenate® D-110N, ethyl 2-oxo-2-phenylacetate, Romascone® (methyl 2,2-dimethyl-6-methylene-1-cyclohexanecarboxylate, origin: Firmenich SA) or/and Hedione® HC (methyl 2-((1S,2R)-3-oxo-2-pentylcyclopentyl)acetate, origin: Firmenich SA), guanazole at pH 5.
(31) TABLE-US-00003 TABLE 3 Composition of Microcapsules B to J Ethyl 2-oxo- Takenate ® 2-phenylacetate D-110N (a Guanazole (a photolabile Romascone ® PVOH Perfume oil/ Micro- polyisoyanate) (a polyamine) α-ketoester) (a perfume oil) Hedione ® HC 18-88 Water Photolabile Shell/Oil capsule [g] [g] [g] [g] (a perfume oil) [g] [g] compound ratio phase ratio B 4.70 0.86 15.77 1.76 — 0.42 46.59 0.11 0.32 C 2.34 0.43 13.64 3.39 — 0.46 50.64 0.25 0.16 D 3.52 0.65 14.03 3.51 — 0.42 46.70 0.25 0.24 E 2.34 0.44 8.81 8.76 — 0.42 46.60 1 0.16 F 3.52 0.66 8.76 8.76 — 0.44 48.97 1 0.24 G 4.70 0.87 8.76 8.77 — 0.42 46.58 1 0.32 H 2.35 0.43 4.39 13.42 — 0.42 46.59 3 0.16 I 2.36 0.44 4.38 6.57 6.59 0.42 46.58 3 0.16 J 2.34 0.43 1.76 7.88 7.88 0.42 46.60 9 0.16
c) Preparation of Microcapsules K According to the General Protocol
(32) Microcapsules K were prepared with Takenate® D-110N, ethyl 3-methyl-2-oxopentanoate, Romascone®, Hedione® HC, and guanazole at pH 5.
(33) TABLE-US-00004 TABLE 4 Composition of Microcapsules K Product Quantity (g) Takenate ® D-110N (a polyisocyanate) 2.36 Ethyl-3-methyl-2-oxopentanoate (a photolabile α-ketoester; 4.38 origin: Firmenich SA) Hedione ® HC (a perfume oil) 6.59 Romascone ® (a perfume oil) 6.57 PVOH 18-88 0.42 Guanazole (a polyamine) 0.44 Water 46.58 Perfume oil/Photolabile compound ratio 3 Shell/Oil phase ratio 0.16
d) Preparation of Microcapsules L According to the General Protocol
(34) Microcapsules L were prepared with Takenate® D-110N, ethyl 2-oxopropanoate, Romascone® and guanazole at pH 5.
(35) TABLE-US-00005 TABLE 5 Composition of Microcapsules L Product Quantity (g) Takenate ® D-110N (a polyisocyanate) 3.51 Ethyl 2-oxopropanoate (a photolabile α-ketoester) 8.76 Romascone ® (a perfume oil) 8.76 PVOH 18-88 0.42 Guanazole (a polyamine) 0.66 Water 46.60 Perfume oil/Photolabile compound ratio 1 Shell/Oil phase ratio 0.24
e) Preparation of Microcapsules M According to the General Protocol
(36) Microcapsules M were prepared with Takenate® D-110N,2-oxo-2-phenylacetic acid, Romascone® and guanazole at pH 5.
(37) TABLE-US-00006 TABLE 6 Composition of Microcapsules M Product Quantity (g) Takenate ® D-110N (a polyisocyanate) 3.51 2-Oxo-2-phenylacetic acid (a photolabile α-ketoacid) 4.37 Romascone ® (a perfume oil) 13.13 PVOH 18-88 0.42 Guanazole (a polyamine) 0.65 Water 47.12 Perfume oil/Photolabile compound ratio 3 Shell/Oil phase ratio 0.24
f) Preparation of Microcapsules N According to the General Protocol
(38) Microcapsules N were prepared with Takenate® D-110N, isopropyl 2-oxo-2-phenylacetate, Romascone® and guanazole at pH 5.
(39) TABLE-US-00007 TABLE 7 Composition of Microcapsules N Product Quantity (g) Takenate ® D-110N (a polyisocyanate) 3.51 Isopropyl 2-oxo-2-phenylacetate (a photolabile α-ketoester) 8.75 Romascone ® (a perfume oil) 8.75 PVOH 18-88 0.42 Guanazole (a polyamine) 0.66 Water 46.63 Perfume oil/Photolabile compound ratio 1 Shell/Oil phase ratio 0.24
g) Preparation of Microcapsules O Prepared with a Melamine-Formaldehyde Aminoplast Shell
(40) In a 250 mL Schmizo reactor, Urecoll SMV (Origin: BASF, 4.70 g), Alcapsol 144 (Origin: CIBA, 4.72 g) were dissolved in water (56.47 g) to give a colorless solution at pH 5.03 in the presence of acetic acid. Reaction mixture was stirred at room temperature for 1 h. A solution of Takenate® D-110N (0.62 g), ethyl 2-oxo-2-phenylacetate (11.02 g) and Romascone® (11.03 g) was added onto the aqueous solution. An emulsion was prepared by Ultra-Turrax stirring (model S25N 10G) at 13'500 rpm for 2 min. The droplet size was controlled by light microscopy. The emulsion was then introduced at room temperature into a 250 mL reactor and stirred with an anchor at 350 rpm. The reaction mixture was warmed up from room temperature to 90° C. during 1 h, and then kept at 90° C. for 3 h to afford a white dispersion.
h) Preparation of Microcapsules P Prepared with a Formaldehyde-Free Aminoplast Shell
(41) In a round bottom flask of 100 mL, oxalaldehyde (2.12 g), 2,2-dimethoxyacetaldehyde (1.71 g), 2-oxoacetic acid (0.74 g4), benzene-1,3,5-triamine (1.11 g) were dissolved in water (1.90 mL) at pH 9.44. Reaction mixture was stirred at 45° C. for 25 min and water (8.35 mL) was added at pH 9.3. Reaction mixture was added onto a solution of 1H-1,2,4-triazole-3,5-diamine (0.98 g) and Ambergum 1221 in solution at 2 wt % in water (33.2 g). A solution of ethyl 2-oxo-2-phenylacetate (10.51 g), Romascone® (10.51 g) with and Takenate® D-110N (2.65 g) was added onto the reaction mixture and an emulsion was prepared with an Ultra-Turrax stirrer (model S25N 10G) at 21'000 rpm at room temperature for 2 min. Emulsion was stirred at 60° C. for 4 h. Medium was slowly cooled to room temperature under stirring.
Comparative Example 3
Preparation of Comparative Microcapsules without a Photolabile α-Ketoacid or α-Ketoester (Capsules According to the Prior Art)
a) Preparation of Comparative Microcapsules A Corresponding to Microcapsules A without a Photolabile α-Ketoacid or α-Ketoester
(42) In a beaker, a polyisocyanate (Desmodur® N100, 1.17 g, 6.1 mmol) was dissolved in 4-tert-butylcyclohexyl acetate (18.00 g, 91.0 mmol). The oil phase with the fragrance was added to an aqueous solution of PVOH 18-88 (50 g, 1 wt % in water). An emulsion was prepared by Ultra-Turrax stirring (model S25N 10G) at 24'000 rpm for 2 min. The droplet size was controlled by light microscopy. The emulsion was then introduced at room temperature into a 250 mL reactor and stirred with an anchor at 350 rpm. A solution of guanidine carbonate (0.4 g, 4.4 mmol) in water (2 g) was added dropwise to the emulsion during 1 h. The reaction mixture was heated to 70° C. during 1 h, then kept at 70° C. for 2 h, and cooled to room temperature to afford a white dispersion.
b) Preparation of Comparative Microcapsules B Corresponding to Microcapsules F with a Photolabile Profragrance According to WO 2013/079435 Instead of a Photolabile α-Ketoacid or α-Ketoester
(43) Comparative Microcapsules B were prepared with Takenate® D-110N, phenethyl 2-oxo-2-phenylacetate, Romascone® and guanazole at pH 5, according to general protocol of Example 3.
(44) TABLE-US-00008 TABLE 8 Composition of Comparative Microcapsules B Quantity Product (g) Takenate ® D-110N (a polyisocyanate) 3.52 Phenethyl 2-oxo-2-phenylacetate (a photolabile α-ketoester) 8.75 Romascone ® (a perfume oil) 8.77 PVOH 18-88 0.44 Guanazole (a polyamine) 0.66 Water 48.56 Perfume oil/Photolabile compound ratio 1 Shell/Oil phase ratio 0.24
c) Preparation of Comparative Microcapsules C Corresponding to Microcapsules E without a Photolabile α-Ketoacid or α-Ketoester
(45) Comparative Microcapsules C were prepared with Takenate® D-110N, Hedione® HC, Romascone® and guanazole, according to the general protocol of Example 3.
(46) TABLE-US-00009 TABLE 9 Composition of Comparative Microcapsules C Product Quantity (g) Takenate ® D-110N (a polyisocyanate) 3.52 Hedione ® HC (a perfume oil) 8.75 Romascone ® (a perfume oil) 8.77 PVOH 18-88 0.44 Guanazole (a polyamine) 0.65 Water 48.57 Perfume oil/Photolabile compound ratio 1 Shell/Oil phase ratio 0.24
Example 4
Release of the Oil Phase from the Microcapsules after Exposure to Light
(47) Release of the Oil Phase from Microcapsules Containing a Photolabile α-Ketoester According to the Invention Upon Exposure to Light Followed by Confocal Microscopy
(48) To demonstrate the release of the oil phase from the microcapsules according to the invention upon exposure to light, a dispersion of Microcapsules D, obtained as described in Example 3b, were diluted with water (2×) and left decanting. The supernatant water phase was pipetted off, and the remaining microcapsule dispersion further diluted with water. This dispersion was then placed onto a glass slide and left drying for 2 h. The glass slide was examined on a confocal microscope (Leica DM RXE, equipped with a DFC300FX camera) using an image magnification of 1.6× and 40×. To localize the microcapsules on the glass slide white light was used. Then the UVA-light (340-380 nm) was switched on and photographs were taken at regular time intervals.
(49)
(50) Similar observations were made with a series of other microcapsules according to the present invention and prepared as described in Example 3.
(51) Release of the Oil Phase from Microcapsules Containing a Photolabile α-Ketoester According to the Invention Upon Exposure to Light Followed by Dynamic Headspace Analysis
(52) Dispersions of microcapsules, obtained as described in Examples 3 and Comparative Examples 3, were diluted in water to have the same concentration of fragrance in the oil phase in all samples. An aliquot (0.1 to 0.2 g) of these dispersions was put onto a glass slide (aliquots where chosen to have the same amount of perfume on each experiment) and kept at room temperature in the dark for 24 h. The composition of these dispersions are listed in Table 10. The glass slide was then placed inside a headspace sampling cell (ca. 500 mL of inner volume), and exposed to a constant air flow of ca. 200 mL/min. The air was filtered through activated charcoal and aspirated through a saturated solution of NaCl to give a constant humidity of ca. 75%. Glass slides were kept in the dark and after 5 min the evaporated volatiles were adsorbed for 10 min onto a clean Tenax® cartridge (0.10 g). Then the glass slides were irradiated with xenon light (Heraeus Suntest CPS at about 45000 lux). The evaporated volatiles were adsorbed for 10 min onto a clean Tenax® cartridge (0.10 g) every 15 min. The cartridges were thermally desorbed on a Perkin Elmer TurboMatrix ATD thermodesorber, injected onto a Agilent Technologies 7890A gas chromatograph equipped with a HP-1 capillary column and eluted using a temperature gradient starting at 60° C. then heating to 200° C. at 15° C./min. The amount of fragrances released was quantified by external standard calibration.
(53) The results obtained from the headspace analysis after irradiation of the different samples are summarized in
(54) TABLE-US-00010 TABLE 10 Composition of the dispersions put onto the glass slides for headspace analysis Mass of Mass of Concentration of Dispersion dispersion [g] water [g] volatile (wt %) Comparative 0.104 5.036 0.51 Microcapsules A (Comparative Example 3a) (Prior art) Comparative 0.100 5.200 0.50 Microcapsules B (Comparative Example 3b) (Prior art) Comparative 0.100 5.000 0.51 Microcapsules C (Comparative Example 3c) (Prior art) Microcapsules A 0.518 4.724 0.49 (Example 3a) Microcapsules D 0.106 2.622 0.21 (Example 3b) Microcapsules E 0.100 5.000 0.51 (Example 3b) Microcapsules F 0.102 5.294 0.52 (Example 3b) Microcapsules G 0.100 5.000 0.50 (Example 3b) Microcapsules I 0.100 4.000 0.67 (Example 3b) Microcapsules K 0.109 5.003 0.56 (Example 3c) Microcapsules P 0.100 4.200 0.51 (Example 3h)
(55) The data in
Example 5
Release of the Oil Phase from the Microcapsules after Exposure to Light in an all Purpose Cleaner Application
(56) The use as perfuming ingredient of the present invention's microcapsules has been tested in an all purpose surface cleaner (APC). An APC formulation with the following final composition has been prepared:
(57) TABLE-US-00011 Neodol ® 91-8 (origin: Shell Chemicals) 5.0% by weight Marlon ® A 375 (origin: Huls AG) 4.0% by weight Sodium cumolsulphonate 2.0% by weight Kathon ® CG (origin: Rohm and Haas) 0.2% by weight Water 88.8% by weight
(58) An aqueous dispersion of Microcapsules E according to the present invention (17.8 mg), prepared as described in Example 3b, containing Romascone® as the oil phase and ethyl 2-oxo-2-phenylacetate as the photolabile α-ketoester capable of generating a gas upon exposure to light, was weighed into the APC formulation (1 mL). Then the sample was diluted with demineralized tap water (9 mL). As the reference, another APC sample was prepared in the same way using an aqueous dispersion of Comparative Microcapsules C (17.8 mg), prepared as described in Comparative Example 3c, containing the same amount of Romascone® as Microcapsules E and Hedione® HC as the oil phase, but no photolabile α-ketoacid or α-ketoester capable of generating a gas. The two samples were vigorously shaken and then each deposited as a film onto a glass plate (ca. 4×10 cm) by carefully pipetting 0.75 mL of the diluted samples onto the surface of the substrate. The samples were then covered with a ca. 2.5 L crystallizing dish and left standing at room temperature in the dark. After one day, the substrates were each placed inside a headspace sampling cell (ca. 625 mL) and exposed to a constant air flow of ca. 200 mL/min. The air was filtered through active charcoal and aspirated through a saturated solution of NaCl (to ensure a constant humidity of the air of ca. 75%). The headspace sampling cells were placed inside the xenon lamp (described above). Without switching on the lamp, the volatiles were adsorbed onto a waste Tenax® cartridge during 5 min, then onto a clean Tenax® cartridge during 10 min. Then the lamp was switched on and the samples were exposed to xenon light at about 45000 lux. The volatiles were adsorbed onto a clean Tenax® cartridge during 10 min and onto a waste Tenax® cartridge during 5 min. This sequence was repeated 3 times. Then the volatiles were adsorbed onto a clean Tenax® cartridge during 10 min and onto a waste Tenax® cartridge during 20 min. This sequence was repeated twice. A total of eight data points was collected (the first one without exposure to light; the seven other ones upon continuous exposure to xenon light). The waste cartridges were discarded; the others were desorbed on a Perkin Elmer TurboMatrix ATD 350 thermodesorber coupled to an Agilent Technologies 7890A GC System equipped with a HP-5 MS capillary column (30 m, i.d. 0.25 mm, film 0.25 μm) and an Agilent Technologies 5975C Series GC/MSD quadrupole mass spectrometer. The amount of Romascone® in the headspace was quantified by GC/MS by eluting the volatiles with a two step temperature gradient starting at 60° C. for 1 min, then going to 200° C. at 15° C./min and to 260° C. at 25° C./min and by using selected ion monitoring. Headspace concentrations (in ng/L air) were obtained by external standard calibrations of Romascone® using ethanol solutions of five different concentrations and injecting 0.2 μL of the calibration solutions onto clean Tenax® cartridges, which were immediately desorbed under the same conditions as those resulting from the headspace sampling. All measurements were performed at least twice.
(59) The headspace concentrations of Romascone® measured above the glass plates are listed in Table 11.
(60) TABLE-US-00012 TABLE 11 Headspace concentrations of Romascone ® released from microcapsules in the dark and after the exposure to xenon light (at 45000 lux) in an APC application on glass. Headspace concentration of Headspace concentration of Romascone ® released from Romascone ® released from Comparative Microcapsules Microcapsules E containing C containing Romascone ® Romascone ® and ethyl 2- and Hedione ® HC and no oxo-2-phenylacetate as the Datapoint After exposure photolabile α-ketoester photolabile α-ketoester N.sup.o to [ng/L] of air [ng/L] of air 1 Dark (15 min) 77.3 11.7 2 Light (10 min) 40.3 5.7 3 Light (25 min) 12.1 348.2 4 Light (40 min) 14.9 1285.8 5 Light (55 min) 25.9 1672.5 6 Light (70 min) 24.3 1052.2 7 Light (100 min) 23.9 486.2 8 Light (130 min) 18.9 153.7
(61) After 40 min of irradiation with xenon light, about 85 times more Romascone® was released into the headspace above the microcapsules according to the invention as compared to the reference sample. These data clearly demonstrate that considerably higher headspace concentrations of Romascone® can be released by using a photolabile α-ketoester capable of generating a gas and exposing the sample to light as compared to a reference microcapsule without photolabile α-ketoester. Furthermore, the release of the oil phase from the microcapsules according to the present invention does not require a mechanical breakage of the microcapsules, typically obtained by rubbing or scratching the capsules. The microcapsules according to the present invention are thus suitable to increase the amount of fragrance released from an all purpose cleaner formulation on hard surfaces.
Example 6
Release of the Oil Phase from the Microcapsules after Exposure to Light in a Fabric Softener Application
(62) The use as perfuming ingredient of the present invention's microcapsules has been tested in a fabric softener. A fabric softener formulation with the following final composition was used:
(63) TABLE-US-00013 Stepantex ® VL90 A (origin: Stepan) 16.5% by weight Calcium chloride (10% aq. solution) 0.6% by weight Water 82.9% by weight
(64) An aqueous dispersion of Microcapsules E according to the present invention (150.9 mg), prepared as described in Example 3b, containing Romascone® as the oil phase and ethyl 2-oxo-2-phenylacetate as the photolabile α-ketoester capable of generating a gas upon exposure to light, and water (1 mL) were added to the above mentioned fabric softener formulation (1.8 g). As the reference, another fabric softener sample was prepared in the same way using an aqueous dispersion of Comparative Microcapsules C (150.3 mg), prepared as described in Comparative Example 3c, containing the same amount of Romascone® as Microcapsules E and Hedione® HC as the oil phase, but no photolabile α-ketoacid or α-ketoester capable of generating a gas.
(65) After homogenization, the samples were dispersed in a beaker with 600 mL of demineralized cold tap water. An aliquot of the dispersions (4 g) were each pipetted onto the surface of a standard cotton sheet (EMPA cotton test cloth Nr. 221, origin: Eidgenossische Materialprüfanstalt (EMPA), pre-washed with an unperfumed detergent powder and cut to ca. 12×12 cm sheets). The cotton sheets were line-dried for one day in the dark and then each put inside a headspace sampling cell (ca. 160 mL). The headspace sampling cells were placed inside the xenon lamp (described above), thermostatted at 25° C. and exposed to a constant air flow of ca. 200 mL/min. The air was filtered through active charcoal and aspirated through a saturated solution of NaCl (to ensure a constant humidity of the air of ca. 75%). The volatiles were sampled and analyzed as described above (Example 5). The measurements were performed in duplicate.
(66) The headspace concentrations of Romascone® measured above the cotton sheets are listed in Table 12.
(67) TABLE-US-00014 TABLE 12 Headspace concentrations of Romascone ® released from microcapsules in the dark and after the exposure to xenon light (at 45000 lux) in a fabric softener formulation on cotton. Headspace concentration of Headspace concentration of Romascone ® released from Romascone ® released from Comparative Microcapsules Microcapsules E containing C containing Romascone ® Romascone ® and ethyl 2- and Hedione ® HC and no oxo-2-phenylacetate as the Datapoint After exposure photolabile α-ketoester photolabile α-ketoester N.sup.o to [ng/L] of air [ng/L] of air 1 Dark (15 min) 442.1 183.8 2 Light (10 min) 184.6 81.8 3 Light (25 min) 120.1 69.1 4 Light (40 min) 62.7 87.3 5 Light (55 min) 24.1 82.4 6 Light (70 min) 14.7 66.7 7 Light (100 min) 8.3 51.7 8 Light (130 min) 5.2 42.2
(68) The data show that less Romascone® was released from Microcapsules E containing the photolabile α-ketoester as compared to the Comparative Microcapsules C without photolabile α-ketoester when the sampling was performed in the dark (Datapoint 1). After switching on the light, a long-lasting effect of Romascone® release was observed for the sample containing Microcapsules E according to the invention with respect to the reference. Higher headspace concentrations of Romascone® were measured after exposure of the microcapsules to light for 40 min (Datapoint 4). After exposure to light for 130 min (Datapoint 8) about 8 times more Romascone® was released from Microcapsules E according to the invention then from the reference. The microcapsules according to the present invention are thus suitable to increase the amount of fragrance released from a fabric softener formulation on textiles.