CORE-SHELL ENCAPSULATE COMPOSITION COMPRISING A BENEFIT AGENT

Abstract

Described is an encapsulated composition comprising at least one core-shell microcapsule. The at least one core-shell microcapsule comprises a core comprising at least one benefit agent and a shell surrounding the core. The shell comprises a polymeric stabilizer that is formed by combination of a polymeric surfactant with at least one aminosilane. Disclosed are also a method of preparing an encapsulated composition and a use of such an encapsulated composition to enhance the performance of perfume and/or cosmetic ingredients in consumer goods.

Claims

1. An encapsulated composition comprising at least one core-shell microcapsule, wherein the at least one core-shell microcapsule comprises a core comprising at least one benefit agent and a shell surrounding the core, wherein the shell comprises a polymeric stabilizer that is formed by combination of a polymeric surfactant with at least one aminosilane, wherein the polymeric surfactant comprises a polysaccharide comprising carboxylic acid groups.

2. The encapsulated composition according to claim 1, wherein the polysaccharide comprising carboxylic acid groups comprises uronic acid units, in particular hexuronic acid units.

3. The encapsulated composition according to claim 2, wherein the hexuronic acid units are selected from the group consisting of galacturonic acid units, glucuronic acid units, in particular 4-O-methyl-glucuronic acid units, guluronic acid units and mannuronic acid units.

4. The encapsulated composition according to claim 1, wherein the polysaccharide comprising carboxylic acid groups is branched.

5. The encapsulated composition according to claim 1, wherein the carboxylic acid groups are partially present in the form of the corresponding methyl ester.

6. The encapsulated composition according to claim 5, wherein the percentage of carboxylic acid groups that are present in the form of the corresponding methyl ester is from 3% to 95%.

7. The encapsulated composition according to claim 1, wherein the carboxylic acid groups are at least partially present in the form of the corresponding carboxylate salt.

8. The encapsulated composition according to claim 1, wherein the polysaccharide comprising carboxylic acid groups is at least partially acylated.

9. The encapsulated composition according to claim 1, wherein the polymeric surfactant is selected from pectin, gum arabic and an alginate.

10. The encapsulated composition according to claim 1, wherein the polymeric surfactant causes a surface tension of less than 45 mN/m, in a 1 wt.-% aqueous solution containing 0.01 wt.-% of sodium chloride, when measured after 1 h of equilibration at pH 4.5 at a temperature of 25° C.

11. The encapsulated composition according to claim 1, wherein the aminosilane is a bipodal aminosilane.

12. The encapsulated composition according to claim 11, wherein the bipodal aminosilane is a secondary aminosilane.

13. The encapsulated composition according to claim 12, wherein the secondary bipodal aminosilane is bis(3-(triethoxysilyl)propyl)amine.

14. The encapsulated composition according to claim 1, wherein the aminosilane to polymeric surfactant weight ratio is from 0.1 to 1.1.

15. The encapsulated composition according to claim 1, wherein the polymeric stabilizer is formed by combination of a polymeric surfactant with at least one aminosilane and further a polyfunctional isocyanate.

16. The encapsulated composition according to claim 15, wherein the polyfunctional isocyanate is 2-ethylpropane-1,2,3-triyl tris((3-(isocyanatomethyl)phenyl)carbamate).

17. The encapsulated composition according to claim 9, wherein the polymeric stabilizer is formed by combination of pectin with bis(3-(triethoxysilyl)propyl)amine.

18. The encapsulated composition according to claim 1, comprising at least one core-shell microcapsule, wherein the at least one core-shell microcapsule comprises a core comprising at least one benefit agent and a shell surrounding the core, wherein the shell comprises a polymeric stabilizer that is formed by combination of a polymeric surfactant with at least one aminosilane, wherein the shell additionally comprises a polysaccharide.

19. The encapsulated composition according to claim 18, wherein the polysaccharide is deposited on the outer surface of the capsule shell formed by the polymeric stabilizer.

20. The encapsulated composition according to claim 18, wherein the shell is further stabilized with a stabilizing agent.

21. A method of preparing an encapsulated composition, in particular an encapsulated composition according to claim 1, the method comprising the steps of: a) Providing a polymeric surfactant; b) Providing an aqueous phase; c) Dissolving or dispersing the polymeric surfactant in the aqueous phase; d) Providing at least one aminosilane; e) Providing an oil phase comprising at least one benefit agent; f) Optionally: Dissolving the at least one aminosilane in the oil phase; g) Emulsifying the oil phase and the aqueous phase in presence of both of the polymeric surfactant and the aminosilane to form an emulsion of oil droplets in the aqueous phase; h) Causing the at least one aminosilane and the polymeric surfactant to form a shell at the oil-water interface of the emulsified oil droplets, thereby forming a slurry of microcapsules; i) Optionally: Adding a polysaccharide, preferably a polysaccharide comprising beta (1.fwdarw.4) linked monosaccharide units, even more preferably a cellulose derivative, in particular selected form the group consisting of hydroxyethyl cellulose, hydroxpropylmethyl cellulose, cellulose acetate and carboxymethyl cellulose, preferably hydroxyethyl cellulose, to the microcapsule slurry formed in step h).

22. An encapsulated composition produced by the method according to claim 21.

23. A method of enhancing the performance of a benefit agent in a consumer product, the method comprising the step of utilizing an encapsulated composition according to claim 1, in the consumer product.

24. A consumer product comprising an encapsulated composition according to claim 1, wherein the consumer product is selected from the group consisting of fabric care detergents and conditioners, hair care conditioners, shampoos, heavy duty liquid detergents, hard surface cleaners, detergent powders, soaps, shower gels and skin care products.

25. A polymeric stabilizer formed by combination of a polymeric surfactant with at least one aminosilane, wherein the polymeric surfactant comprises a polysaccharide comprising carboxylic acid groups.

26. The polymeric stabilizer according to claim 25 used in the encapsulation of a benefit agent.

27. The encapsulated composition according to claim 13, wherein the polymeric stabilizer is formed by combination of pectin with bis(3-(triethoxysilyl)propyl)amine.

Description

[0093] The present disclosure also relates to a method for enhancing the performance of a benefit agent in a consumer product by adding an encapsulated composition according to the present invention.

[0094] Furthermore, the present disclosure refers to a method of encapsulating a benefit agent, wherein the polymeric stabilizer as described herein above stabilizes and encapsulates the oil droplets of the oil in water emulsion, and wherein the oil phase comprises the at least one benefit agent.

[0095] Particular features and further advantages of the present invention become apparent from the following examples.

Example 1—Formation of Microcapsules Having First Shell Comprising Pectin as Polymeric Surfactant

[0096] The microcapsules have been obtained by performing the steps of: [0097] a) Preparing a core composition by admixing 0.7 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine) and 25 g of fragrance composition; [0098] b) Emulsifying the core composition obtained in step a) in a mixture of 1.4 g low methoxylated grade pectin (of type APA 220, ex Roeper) in 68.6 g of water by using a 300 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 850 rpm at a temperature of 25+/−2° C. for 10 min; [0099] c) Adjusting the pH of the continuous phase of the emulsion to 6.5+/−0.5 with a 10% sodium hydroxide solution in water and maintaining the system at a temperature of 25+/−2° C. for 1 h while maintaining stirring as in step b); [0100] d) Increasing progressively the temperature to 85° C. over 2.5 h and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in steps b) and c) to complete the formation of core-shell capsules; e) Letting the slurry of core-shell capsules obtained in step d) cool to room temperature.

[0101] The solid content of each of the slurries 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 ratio of the measured solid content to the theoretical solid content calculated based on the weight of perfume and encapsulating materials involved is taken as a measurement of encapsulation yield, expressed in wt.-%.

[0102] The solid content of the slurry obtained was 5 wt.-%, the volume average size (d50) of the capsules was 17±3 μm and the encapsulation efficiency of 16%.

Example 2—Formation of Microcapsules Having First Shell Comprising Pectin as Polymeric Surfactant and Isocyanate

[0103] The microcapsules have been obtained by performing the steps of: [0104] a) Preparing a core composition by admixing 0.7 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine) and 0.4 g of Takenate D-110N (ex Mitsui) and 25 g of fragrance composition; [0105] b) Emulsifying the core composition obtained in step a) in a mixture of 1.4 g low methoxylated grade pectin (of type APA 220, ex Roeper) in 68.6 g of water by using a 300 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 850 rpm at a temperature of 25+/−2° C. for 10 min; [0106] c) Adjusting the pH of the continuous phase of the emulsion to 4.5+/−0.5 with a 10% sodium hydroxide solution in water and maintaining the system at a temperature of 25+/−2° C. for 1 h while maintaining stirring as in step b); [0107] d) Increasing progressively the temperature to 85° C. over 2.5 h and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in steps b) and c) to complete the formation of core-shell capsules; [0108] e) Letting the slurry of core-shell capsules obtained in step d) cool to room temperature.

[0109] The solid content of the slurry obtained was 27 wt.-%, the volume average size (d50) of the capsules was 15 μm and the encapsulation efficiency of 95+/−5%.

Example 3—Formation of Microcapsules Comprising ZeMac E400 and 2-Hydroxyethyl Cellulose

[0110] The microcapsules have been obtained by performing the steps of (Example 3.1): [0111] a) Preparing a core composition by admixing 1 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine), 0.4 g of Takenate D-110N (ex Mitsui) and 35.5 g of fragrance composition; [0112] b) Emulsifying the core composition obtained in step a) in a mixture of 1.5 g ZeMac E400 (ex Vertellus) in 51.1 g of water by using a 300 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 800 rpm at a temperature of 25+/−2° C. for 10 min; [0113] c) Adjusting the pH of the continuous phase of the emulsion to 4.4+/−0.5 with a 10% sodium hydroxide solution in water and maintaining the system at a temperature of 25+/−2° C. for 1 h while maintaining stirring as in step b); [0114] d) Increasing progressively the temperature to 85° C. over 2.5 h and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in steps b) and c) to complete the formation of core-shell capsules; [0115] e) Adding 37.5 g of a 7.2 wt.-% of a solution of 2-hydroxyethyl cellulose in water and keeping stirring for 1 h at 85° C.; [0116] f) Adding 0.8 g of a solution of citric acid diluted at 30% in water and keeping stirring for 1 h at 85° C.; [0117] g) Letting the slurry of core-shell capsules obtained in step f) cool to room temperature.

[0118] The solid content of the slurry obtained was 32 wt.-%, the volume average size (d50) of the capsules was 15 μm and the encapsulation efficiency of 95+/−5%.

[0119] For application in hair care conditioner (Example 3.2), 14.4 g of a 4% Polyquaternium 10 (Ucare JR400, ex Dow Chemicals) in water was added in the slurry after cooling.

Example 4—Formation of Microcapsules Comprising Low Methoxylated Grade Pectin and 2-Hydroxyethyl Cellulose

[0120] The microcapsules have been obtained by performing the steps of (Example 4.1): [0121] a) Preparing a core composition by admixing 0.57 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine), 0.8 g of Takenate D-11ON (ex Mitsui) and 20 g of fragrance composition; [0122] b) Emulsifying the core composition obtained in step a) in a mixture of 1.1 g low methoxylated grade pectin (of type APA 220, ex Roeper) in 54.9 g of water by using a 300 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 850 rpm at a temperature of 25+/−2° C. for 10 min; [0123] c) Adjusting the pH of the continuous phase of the emulsion to 4.5+/−0.5 with a 10% sodium hydroxide solution in water and maintaining the system at a temperature of 25+/−2° C. for 1 h while maintaining stirring as in step b); [0124] d) Increasing progressively the temperature to 85° C. over 2.5 h and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in steps b) and c) to complete the formation of core-shell capsules; e) Adding 21.4 g of 2-hydroxyethyl cellulose diluted at 7.2% in water and continue stirring for 1 h at 85° C.; [0125] f) Adding 0.8 g of a solution of citric acid diluted at 30% in water and continue stirring for 1 h at 85° C.; [0126] g) Letting the slurry of core-shell capsules obtained in step f) cool to room temperature.

[0127] The solid content of the slurry obtained was 30 wt.-%, the volume average size (d50) of the capsules was 20 μm and the encapsulation efficiency of 90+/−5%.

[0128] In Example 4.2, the microcapsules have been obtained as for Example 4.1, but the 2-hydroxyethyl cellulose has been added as a powder to the system in step e). In this case, the amount of 2-hydroxyethyl cellulose was 1.5 g. The solid content of this slurry obtained was 30%, the volume average size (d50) of the capsules was 17+/−3 μm and the encapsulation efficiency 90+/−5%.

[0129] For application in hair care conditioner (Example 4.3), 14.4 g of a 4% Polyquaternium 10 (Ucare JR400, ex Dow Chemicals) in water was added in the slurry after cooling.

[0130] In a further example, the microcapsules have been obtained by performing the steps of (Example 4.4): [0131] a) Preparing a core composition by admixing 0.66 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine), 0.47 g of Takenate D-11ON (ex Mitsui) and 38.5 g of fragrance composition; [0132] b) Emulsifying the core composition obtained in step a) in a mixture of 1.35 g low methoxylated grade pectin (of type APA 220, ex Roeper) in 66.2 g of water by using a 300 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 800 rpm at a temperature of 25+/−2° C. for 10 min; [0133] c) Adjusting the pH of the continuous phase of the emulsion to 6+/−1 with a 10% sodium hydroxide solution in water and maintaining the system at a temperature of 25+/−2° C. for 1 h while maintaining stirring as in step b); [0134] d) Increasing progressively the temperature to 85° C. over 2.5 h and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in steps b) and c) to complete the formation of core-shell capsules; [0135] e) Adding 1.8 g of 2-hydroxyethyl cellulose and continue stirring for 30 min at 85° C.; [0136] f) Adding 0.8 g of a solution of citric acid diluted at 30% in water and continue stirring for 1 h at 85° C.; [0137] g) Letting the slurry of core-shell capsules obtained in step f) cool to room temperature.

[0138] The solid content of the slurry obtained was 40 wt.-%, the volume average size (d50) of the capsules was 20+/−5 μm and the encapsulation efficiency of 90+/−5%.

[0139] In Example 4.5, the microcapsules have been obtained as for Example 4.4, but the solution of citric acid has been replaced with benzene-1,3,5-tricarboxylic acid in step f). In this case, the amount of benzene-1,3,5-tricarboxylic acid was 0.3 g. The solid content of this slurry obtained was 40 wt.-%, the volume average size (d50) of the capsules was 20+/−5 μm and the encapsulation efficiency of 95+/−5%.

[0140] In Example 4.6, the microcapsules have been obtained as for Example 4.4, but the solution of citric acid has been replaced with 2,5-furandicarboxylic acid in step f). In this case, the amount of 2,5-furandicarboxylic acid was 0.15 g. The solid content of this slurry obtained was 40 wt.-%, the volume average size (d50) of the capsules was 20+/−5 μm and the encapsulation efficiency of 95+/−5%.

Example 5—Formation of Microcapsules Comprising High Methoxylated Pectin and 2-Hydroxyethyl Cellulose

[0141] The microcapsules have been obtained by performing the steps of (Example 5.1): [0142] a) Preparing a core composition by admixing 0.57 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine), 0.8 g of Takenate D-11ON (ex Mitsui) and 20 g of fragrance composition; [0143] b) Emulsifying the core composition obtained in step a) in a mixture of 1.1 g high methoxylated grade pectin (of type APA 104, ex Roeper) in 54.9 g of water by using a 300 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 850 rpm at a temperature of 25+/−2° C. for 10 min; [0144] c) Adjusting the pH of the continuous phase of the emulsion to 6.5+/−0.5 with a 10% sodium hydroxide solution in water and maintaining the system at a temperature of 25+/−2° C. for 1 h while maintaining stirring as in step b); [0145] d) Increasing progressively the temperature to 85° C. over 2.5 h and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in steps b) and c) to complete the formation of core-shell capsules; e) Adding 21.4 g of 2-hydroxyethyl cellulose diluted at 7.2% in water and continue stirring for 1 h at 85° C.; [0146] f) Adding 0.8 g of a solution of citric acid diluted at 30% in water and continue stirring for 1 h at 85° C.; [0147] g) Letting the slurry of core-shell capsules obtained in step f) cool to room temperature.

[0148] The solid content of the slurry obtained was 30 wt.-%, the volume average size (d50) of the capsules was 20 μm and the encapsulation efficiency of 90+/−5%.

[0149] In Example 5.2, the microcapsules have been obtained as for Example 5.1, but the 2-hydroxyethyl cellulose has been added as a powder to the system in step e). In this case, the amount of 2-hydroxyethyl cellulose was 1.5 g. The solid content of this slurry obtained was 30 wt.-%, the volume average size (d50) of the capsules was 17+/−3 μm and the encapsulation efficiency of 90+/−5%.

[0150] For application in hair care conditioner (Example 5.3), 14.4 g of a 4% solution of Polyquaternium 10 (Ucare JR400, ex Dow Chemicals) in water was added in the slurry after cooling.

[0151] In a further example, the microcapsules have been obtained by performing the steps of (Example 5.4): [0152] a) Preparing a core composition by admixing 0.66 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine), 0.48 g of Takenate D-11ON (ex Mitsui) and 38.5 g of fragrance composition; [0153] b) Emulsifying the core composition obtained in step a) in a mixture of 1.35 g high methoxylated grade pectin (of type APA 104, ex Roeper) in 66.2 g of water by using a 300 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 800 rpm at a temperature of 25+/−2° C. for 10 min; [0154] c) Adjusting the pH of the continuous phase of the emulsion to 6.5+/−0.5 with a 10% sodium hydroxide solution in water and maintaining the system at a temperature of 25+/−2° C. for 1 h while maintaining stirring as in step b); [0155] d) Increasing progressively the temperature to 85° C. over 2.5 h and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in steps b) and c) to complete the formation of core-shell capsules; [0156] e) Adding 1.8 g of 2-hydroxyethyl cellulose and continue stirring for 30 min at 85° C.; [0157] f) Adding 0.8 g of a solution of citric acid diluted at 30% in water and continue stirring for 1 h at 85° C.; [0158] g) Letting the slurry of core-shell capsules obtained in step f) cool to room temperature.

[0159] The solid content of the slurry obtained was 40 wt.-%, the volume average size (d50) of the capsules was 20+/−5 μm and the encapsulation efficiency of 90+/−5%.

[0160] In Example 5.5, the microcapsules have been obtained as for Example 5.4, but the solution of citric acid has been replaced with benzene-1,3,5-tricarboxylic acid in step f). In this case, the amount of benzene-1,3,5-tricarboxylic acid was 0.3 g. The solid content of this slurry obtained was 40 wt.-%, the volume average size (d50) of the capsules was 20+/−5 μm and the encapsulation efficiency of 95+/−5%.

[0161] In Example 5.6, the microcapsules have been obtained as for Example 5.4, but the solution of citric acid has been replaced with 2,5-furandicarboxylic acid in step f). In this case, the amount of 2,5-furandicarboxylic acid was 0.15 g. The solid content of this slurry obtained was 40 wt.-%, the volume average size (d50) of the capsules was 20+/−5 μm and the encapsulation efficiency of 95+/−5%.

Example 6—Formation of Microcapsules Comprising Gum Arabic and 2-Hydroxyethyl Cellulose

[0162] The microcapsules have been obtained by performing the steps of (Example 6.1): [0163] a) Preparing a core composition by admixing 1 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine), 1 g of Takenate D-110 (ex Mitsui), 2.25 g of Bayhydur XP 2547 (ex Covestro) and 35.5 g of fragrance composition; [0164] b) Emulsifying the core composition obtained in step a) in a mixture of 5 g of gum arabic Senegal and 48 g of water by using a 300 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 300 rpm at a temperature of 25+/−2° C. for 10 min; [0165] c) Adjusting the pH of the continuous phase of the emulsion to 4.4+/−0.5 with a 10% formic acid solution in water and maintaining the system at a temperature of 25+/−2° C. for 1 h while increasing the stirring to 700 rpm; [0166] d) Increasing progressively the temperature to 85° C. over 2.5 h and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in step c) to complete the formation of core-shell capsules; [0167] e) Adding 37.1 g of a 1 wt.-% solution of 2-hydroxyethyl cellulose in water and continue stirring for 1 h at 85° C.; [0168] f) Letting the slurry of core-shell capsules obtained in step f) cool to room temperature.

[0169] The solid content of the slurry obtained in step g) was 33.9 wt.-%, the volume average size (d50) of the capsules was 11.7 μm and the encapsulation efficiency of 98 wt.-%.

[0170] In Example 6.2, the process of Example 6.1 was repeated, but with gum tragacanth instead of gum arabic Senegal. Additionally, the quantity of gum tragacanth was half of the quantity of gum arabic Senegal, due to the high viscosity of gum tragacanth.

Example 7—Formation of Microcapsules Comprising Alginate and 2-Hydroxyethyl Cellulose

[0171] The microcapsules have been obtained by performing the steps of (Example 7.1): [0172] a) Preparing a core composition by admixing 0.5 g of bipodal aminosilane (bis(3-triethoxysilylpropyl)amine), 0.04 g of Takenate D-11ON (ex Mitsui) and 17.75 g of fragrance composition; [0173] b) Emulsifying the core composition obtained in step a) in a 26.3 g of an aqueous solution containing 2 wt.-% of alginate (Scogin XL, ex FMC corporation) and 0.1 wt.-% of Tween 85 by using a 100 ml reactor and a cross-beam stirrer with pitched beam operating at a stirring speed of 850 rpm at a temperature of 25+/−2° C. for 10 min; [0174] c) Adjusting the pH of the continuous phase of the emulsion to 5.0+/−0.5 with a 10% formic acid solution in water and maintaining the system at a temperature of 35+/−2° C. for 1 h while increasing the stirring to 700 rpm; [0175] d) Increasing progressively the temperature to 85° C. over 2.5 h; e) Adding 37.5 g of a 7.2 wt.-% solution of 2-hydroxyethyl cellulose in water and maintaining the temperature at 85° C. for 1 h, while maintaining stirring as in step c); [0176] f) Adding 0.8 g of Bayhydur XP2547 and continue to stir for 1 h at 85° C. in order to complete the formation of core-shell capsules; [0177] g) Letting the slurry of core-shell capsules obtained in step f) cool to room temperature.

[0178] The solid content of the slurry obtained in step g) was 22 wt.-%, the volume average size (d50) of the capsules was 40 μm and the encapsulation efficiency of 92%.

[0179] In Example 7.2, microcapsules were obtained under the same conditions as Example 7.1, but Takenate D-110N was replaced by isophtaldehyde. The solid content of the slurry obtained was 26 wt.-%, the volume average size (d50) of the capsules was 40 μm and the encapsulation efficiency of 100%.

Example 8—Aminoplast Capsules (Comparative Example)

[0180] Aminoplast microcapsules were obtained by performing the method disclosed in WO 2016/207187 A1, Example 2b.

[0181] The solid content of the slurry obtained was 45%, the volume average size (d50) of the capsules was 20 μm and the encapsulation efficiency of 100%.

Example 9—Assessment of Leakage of Microcapsules in a Laundry Care Conditioner Base

[0182] The base was an unperfumed commercial proprietary laundry care conditioner base. For each assessment 1 wt.-% of slurry was dispersed in the base under stirring with a paddle mixer. The encapsulated core composition comprised additionally 0.02 wt.-% of Hostasol® Yellow 3G (Clariant) as fluorescent dye. The samples were then stored for 8 weeks at 37° C. The leakage from the capsules was assessed visually by fluorescent light microscopy, operating at 488 nm excitation light wavelength and 515 nm emission light wavelength, according to the following scale: [0183] Poor stability: Collapsed microcapsules and fluorescent droplets are visible; [0184] Average stability: Partially collapsed microcapsules coexist with fluorescent droplets; [0185] Good stability: All capsules are still full of fluorescent core composition and no fluorescent droplets are visible.

[0186] Representative leakage values are given in Table 1, herein below.

Example 10—Assessment of Fragrance Release Performance

[0187] The release performance of the microcapsule slurries was measured by using a texture analyzer (TA XT PLUS, ex TA instruments). 300 microliters of undiluted slurry were deposited on the surface of filter paper in three successive applications of 100 microliters and left to dry overnight. Then, the lower surface of a mechanical sensor probe, consisting of a flat metal cylinder having a diameter of 12.5 micrometer, was applied on the deposited microcapsules with a penetration velocity of 0.01 mm/s.

[0188] As the probe penetrates the bed of microcapsules deposited on the filter paper, it experiences a back elastic force which is proportional to the elastic bending modulus of the microcapsules, which is inversely proportional to the release performance of the microcapsules. The value of the measured force at the 50% deformation of the microcapsule bed is taken as a measurement of the release performance of the microcapsules. The displacement corresponding to 50% deformation point is determined as the half way point between the displacement point where the first contact with the microcapsules occurs, which is marked by the onset of a back force and the point where the probe motion is stopped by the filter paper.

TABLE-US-00001 TABLE 1 Perfume leakage in water/ethanol/cyclohexane and force at 50% deformation for selected examples Leakage in laundry care conditioner Force at 50% Example [visual scale, see Example 9] deformation [N] Example 1 Average   n.a. * Example 2 Average to good 2.6 Example 3.1 Good 3.0 Example 4.1 Good 5.2 Example 4.5 Good 2.6 Example 4.6 Good 2.7 Example 5.1 Good 4.0 Example 5.5 Good n.a. Example 5.6 Good n.a. Example 6.1 Good 4.0 Example 6.2 Poor <1 Example 7.1 Average <1 Example 8 Good 6.5 * Sample too viscous.

[0189] It may be concluded from these results that the capsules according to the present invention have a stability in laundry care conditioner base that is similar to the one of conventional capsules based on aminoplast and polyurea resins.

Example 11—Comparison of Olfactive Performance of New and Conventional Microcapsules

[0190] The olfactive performance of the microcapsule was assessed by a panel of 4 experts who rated the odor intensity on a scale of 1-5 (1=barely noticeable, 2=weak, 3=medium, 4=strong and 5=very strong). When relevant, qualitative comments on the perceived odor direction were recorded.

[0191] For application in laundry care, the samples were evaluated in an unperfumed commercial proprietary fabric care softener. The aforementioned microcapsule slurries were added to a fabric care conditioner composition under gentle stirring with a paddle mixer, so that the level of slurry in the fabric care conditioner base was 1.5 wt.-% referred to the total weight of the hair care conditioner base. 35 g of fabric care conditioner was put in a front-loaded wash machine containing 720 g of terry toweling and operating with a total volume of 15 l water. The “out-of-the-wash machine” odor intensity was assessed on wet toweling within 5 min after having removed the toweling from the machine. The pre-rub olfactive evaluation was performed after drying the toweling for 24 h at room temperature. The post-rub evaluation was performed by gently rubbing one part of the toweling.

[0192] For application in hair care conditioner, the samples were evaluated in a unperfumed hair care conditioner. The aforementioned microcapsule slurries 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 min 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. The pre-rub olfactive evaluation was performed on the swatches after 4 h. For this evaluation, the swatches were handled carefully in order to minimize the risk of breaking the microcapsules mechanically. The post-rub olfactive evaluation was performed after drying the swatches for 24 h at room temperature. This evaluation was performed by gently rubbing one part of each swatch.

TABLE-US-00002 TABLE 2 Olfactive performance on terry toweling and hair swatch of freshly prepared and aged microcapsules Pre-rub Post-rub Intensity intensity intensity on wet on dry on dry Laundry care conditioner Example 3 3.1 +/− 1     3 +/− 0.4 4.4 +/− 0.2 Example 4.3 2.5 +/− 0.8 2.9 +/− 0.3 3.8 +/− 0.5 Example 4.5 2.5 +/− 0.5 1.8 +/− 0.3 3.9 +/− 0.3 Example 5.5 2.5 +/− 0.5 1.8 +/− 0.3 3.9 +/− 0.3 Example 5.6 2.5 +/− 0.5 1.6 +/− 0.2 4.1 +/− 0.3 Example 8 2.9 +/− 0.9 3.4 +/− 0.2 5 Hair conditioner Example 3 2.8 +/− 0.7 4.5 +/− 0.5 5 Example 4.3 3.9 +/− 0.5 2.8 +/− 0.5 4.4 +/− 0.5 Example 8 3.5 +/− 0.3 4 +/− 0 5

[0193] The results show that microcapsules according to the present invention provide perfume performance that is comparable to conventional aminoplast-based microcapsules.