Organic compounds

Abstract

Disclosed is a composition comprising at least one core-shell microcapsule in a suspending medium. The microcapsule comprises a core and a shell around said core. The shell comprises a hyperbranched polysaccharide selected from the group consisting of amylopectins, dextrins, hyperbranched starches, glycogen and phytoglycogen and mixtures thereof.

Claims

1. A composition comprising at least one core-shell microcapsule in a suspending medium for deposition on a keratinous substrate, wherein said microcapsule comprises a core and a shell around said core, wherein said shell comprises a hyperbranched polysaccharide selected from the group consisting of amylopectins, dextrins, hyperbranched starches, glycogen, phytoglycogen and mixtures thereof, wherein the amount of hyperbranched polysaccharide is from 0.01 to 1 wt %, referred to the total weight of the microcapsule suspension and wherein said hyperbranched polysaccharide is embedded into the microcapsule shell.

2. The composition according to claim 1, wherein the ratio of 1,6′-glycosidic bonds to 1,4′-glycosidic bonds in said hyperbranched polysaccharide is greater than 1/50.

3. The composition according to claim 1, wherein said core comprises an ingredient selected from the group consisting of a fragrance ingredient, a cosmetic ingredient and a mixture thereof.

4. The composition according to claim 1, wherein said shell of said at least one core-shell microcapsule comprises a thermosetting resin.

5. A method of embedding hyperbranched polysaccharide into microcapsule shells, said method comprising the steps of: dispersing droplets of a core material in a suspending medium in the presence of a shell-precursor selected from the group consisting of shell-forming monomers, pre-polymers and pre-condensates, to obtain an emulsion; causing said shell-forming monomers, pre-polymers or pre-condensates to react at the interface of the droplets and the suspending medium to obtain a slurry of core-shell microcapsules; adding a hyperbranched polysaccharide to the slurry of core-shell microcapsule, thereby obtaining a composition comprising core-shell microcapsules in a suspending medium for deposition on a keratinous substrate, wherein said hyperbranched polysaccharide is embedded into the shells of said core-shell microcapsules; wherein the hyperbranched polysaccharide is selected from the group consisting of amylopectins, dextrins, hyperbranched starches, glycogen, phytoglycogen and mixtures thereof, and wherein the amount of hyperbranched polysaccharide is from 0.01 to 1 wt %, referred to the total weight of the microcapsule suspension.

6. A method for increasing rinse-resistance of at least one core-shell microcapsule deposited on a keratinous surface, the method comprising the step of embedding a hyperbranched polysaccharide into the shell of the core-shell microcapsule, wherein said microcapsule comprises a core and a shell around said core, wherein the core-shell microcapsule is in a suspending medium for deposition on the keratinous surface, wherein the hyperbranched polysaccharide is selected from the group consisting of amylopectins, dextrins, hyperbranched starches, glycogen, phytoglycogen and mixtures thereof, and wherein the amount of hyperbranched polysaccharide is from 0.01 to 1 wt %, referred to the total weight of the microcapsule suspension.

7. A consumer product comprising a composition according to claim 1.

8. The consumer product according to claim 7, wherein said consumer product is selected from the group consisting of a shampoo, a hair care conditioner, a shower gel and a liquid soap.

9. The composition according to claim 2, wherein the ratio of 1,6′-glycosidic bonds to 1,4′-glycosidic bonds in said hyperbranched polysaccharide is greater than 1/40.

10. The composition according to claim 9, wherein the ratio of 1,6′glycosidic bonds to 1,4′-glycosidic bonds in said hyperbranched polysaccharide is greater than 1/35.

11. The composition according to claim 1, wherein the amount of hyperbranched polysaccharide is from 0.02 to 0.5 wt %, referred to the total weight of the microcapsule suspension.

12. The composition according to claim 11, wherein the amount of hyperbranched polysaccharide is from 0.05 to 0.25 wt %, referred to the total weight of the microcapsule suspension.

13. The composition according to claim 4, wherein the shell of said at least one core-shell microcapsule comprises a thermosetting resin selected from the group consisting of aminoplast resins, polyurea resins, polyacrylic resins and mixtures thereof.

14. The method according to claim 5, additionally comprising the step of adding to said slurry one or more of a suspending agent or a preservative.

15. The method according to claim 5, additionally comprising the step of dehydrating said slurry to form a composition of core-shell microcapsules in powder form.

16. The composition of claim 1 which is a keratinous substrate treatment composition.

Description

(1) Further advantages and particular features of the present invention become apparent from FIG. 1 and from the following discussion of several examples.

(2) FIG. 1 illustrates the deposition and rinse resistance for shampoo and hair care conditioner compositions obtained in Example 3.

EXAMPLE 1

(3) Preparation of aminoplast core-shell microcapsules comprising a hyperbranched polymer embedded in the shell of the core-shell microcapsules and a fragrance as core material.

(4) The microcapsules were prepared by performing the steps of: a) Preparing an aqueous solution containing 72 g of emulsifier LUPASOL™ PA 140 (ex. BASF, 20% active, effective amount of active: 14 g), 19 g of resin precursor LURACOLL™ SD (ex. BASF, 70% active, effective amount or active: 13.3 g) and 6.7 g resorcinol and 324 g water; b) emulsifying 355 g fragrance to the aqueous solution obtained in step a) by mixing at a stirring speed of 1000 rpm, using a a cross-beam stirrer with pitched bean; c) adjusting the pH of the emulsion obtained in a) to a value of 3.5±0.3 by adding 11.1 g of 10% formic acid and heating the emulsion to 90° C.; d) maintaining the temperature at 90° C. over a period of one hour under agitation, to form thermosetting aminoplast resin wall around the droplets, thereby forming a slurry of microcapsules having a diameter of 10 micrometres (μm); e) adding a defined amount of selected hyperbranched polysaccharide solution at 2 wt % in water (as specified hereunder); f) adding 11.1 g of 10% formic acid and 11.1 g of resin precursor LURACOLL™ SD (ex. BASF, 70% active, effective amount or active: 7.8 g), while maintaining the temperature at 90° C. for an additional 2 hours; g) cooling down the slurry to room temperature and adding 3.2 g of 10% solution of ammoniac in water to obtain a pH between 5.5 and 7.

(5) The defined amounts of hyperbranched polysaccharide solution at 2 wt % in water were 50 g of solution (corresponding to 0.1 wt % of hyperbranched polysaccharide in slurry) and 150 g of solution (corresponding to 0.3 wt % of hyperbranched polysaccharide in slurry). The hyperbranched polsacharide was amylopectin.

(6) The solid content of the slurry was measured by using a thermo-balance operating at 120° C. The solid content, expressed as weight percentage of the initial slurry deposited on the balance was taken at the point where the drying-induced rate of weight change had dropped below 0.1%/min. The solid content of the slurry was 42±1 wt %. A comparative example without hyperbranched polymer is obtained by substantially the same process as described above, but with the omission of the hyperbranched polymer addition step f).

EXAMPLE 2

(7) Determination of free polysaccharide in slurries prepared according to Example 1.

(8) The level of free polysaccharide is determined by performing the steps of: a) diluting the slurry to obtain a solid content of about 10 wt % (dilution factor 4); b) centrifuging the diluted slurry for 30 minutes at 3000 rpm; c) sampling the supernatant with a syringe and ultracentrifuging this supernatant for 30 minutes at 13000 rpm; d) sampling again the supernatant and filtering this supernatant through a microporous filter; e) admixing 3 ml of filtered supernatant diluted 10 times in deionized water with 7 ml of concentrated sulfuric acid at 98 vol % (as supplied by Sigma Aldrich); f) cooling down the mixture and completing to 10 ml with deionized water; g) measuring the absorbance at a wavelength of 350 nm and comparing the absorbance value to those of a calibration curve obtained from standard hyperbranched polymer solutions.

(9) The levels of free hyperbranched polymer in the different samples are reported in Table 1 below.

(10) The level of hyperbranched polymer embedded in the shell of the core-shell microcapsules is obtained by subtracting the level of free hyperbranched polymer from the total level of hyperbranched polymer added to the slurry.

EXAMPLE 3

(11) Preparation of shampoo and hair care conditioner compositions and deposition data.

(12) The microcapsule slurries of Example 1 were added to a shampoo composition under gentle stirring with a paddle mixer, so that the level of slurry in the shampoo base was 0.5 wt % referred to the total weight of the shampoo base. The mixture was let to macerate overnight before performing the deposition measurements. 4.8 g of base was applied on 48 g hair swatches by rubbing over 20 seconds. The swatches were then let to rest for 1 minute and then rinsed 30 seconds under running tap water at 37° C. at a flow rate of 3.2 l/min, without touching the swatch by hand.

(13) The deposition values were obtained by image analysis micrographs obtained with a fluorescence light microscope at a magnification of 40×, using Stream Motion software and Hostasol Yellow 3G as fluorescent agent at 0.02 wt % in perfume, 450 nm excitation wavelength and 500 nm emission wavelength.

(14) In the case of hair conditioner, the microcapsule slurries of Example 1 were added to a hair care conditioner composition under gentle stirring with a paddle mixer, so that the level of slurry in the hair care conditioner base was 1 wt % referred to the total weight of the hair care conditioner base. 1.5 g of hair care conditioner was applied on 15 g swatches humidified with 12 g water. The swatches were submitted to a massage, left to stand for 1 minute and then rinse rinsed 30 seconds under running tap water at 37° C. at a flow rate of 3.2 l/min, without touching the swatch by hand.

(15) The deposition values were determined as described herein above for the case of shampoo.

(16) The compositions of the model shampoo and hair care conditioner bases are given in Table 2 and 3.

(17) TABLE-US-00001 TABLE 1 Results for shampoo Polymer Total polymer Level of free embedded in level in slurry polymer the shell Deposition Sample Polymer [%] [%] [%] [# capsules/mm.sup.2] 1 None 0.3 ± 0.1 2 Linear hemicellulose 0.3 0.17 0.13 0.9 ± 0.1 3 Amylopectin 0.1 0.035 0.065 1.8 ± 0.4 4 Amylopectin 0.3 0.12 0.18 1.7 ± 0.2

(18) TABLE-US-00002 TABLE 2 Results for for hair care conditioner Polymer Total polymer Level of free embedded in level in slurry polymer the shell Deposition Sample Polymer [%] [%] [%] [# capsules/mm.sup.2] 1 None 0.3 ± 0.2 2 Linear hemicellulose 0.3 0.17 0.13 .sup. 2 ± 0.9 3 Amylopectin 0.1 0.035 0.065 4.5 ± 1.6 4 Amylopectin 0.3 0.12 0.18 4.7 ± 1.6

(19) The results of Tables 1 and 2 are illustrated in FIG. 1. They confirm that core-shell microcapsules with a shell comprising a hyperbranched polymer show an enhanced deposition and rinse resitance on hair from both shampoo and conditioner compositions, compared to situations where no polymer or a linear polymer is used.

(20) TABLE-US-00003 TABLE 3 Model shampoo base composition Percentage by weight Ingredient trade name INCI name in shampoo PROPYLENE GLYCOL Propylene Glycol 1.00 JAGUAR ™ C-13S (ex. RHODIA) Guar Hydroxypropyltrimonium 0.25 Chloride MARLINAT ™ 242/28 (ex. SASOL) Sodium Laureth Sulfate 25.00 DEHYTON ™ AB 30 (ex. COGNIS) Coco Betaine 5.00 EUPERLAN ™ PK 3000 (ex. COGNIS) Glycol distearate, Laureth-4 and 0.50 Cocoamidopropyl Betaine GLYDANT ™ PLUS LIQ (ex. LONZA) DMDM Hydantoin 0.50 SODIUM CHLORIDE Sodium Chloride 1.20 BC 2102 (ex. BALLU CHIMIE) Dimethiconol Emulsion 2.00 DEIONIZED WATER QSP 100

(21) TABLE-US-00004 TABLE 4 Model hair conditioner base composition Percentage by weight Ingredient trade name INCI name in conditioner PHENONIP ™ (ex. CLARIAN) Phenoxyethanol and Butyl and 0.70 Ethyl and Propyl parabens BRIJ ™ 721 (ex. UNIQEMA/MASSO) Steareth-21 2.00 LANETTE ™ 16 (ex. COGNIS) Cetyl alcohol 1.00 PROPYLENE GLYCOL (ex. PRODH'YG) Propylene glycol 4.00 NATROSOL ™ 250H (ex. AQUALON) Hydroxyethylcellulose 0.90 INCROQUAT ™ CTC 30 (ex. CRODA) Cetrimonium chloride 2.00 DEIONIZED WATER QSP 1100