Cosmetic use as deodorant active agent of a siliceous material obtained by hydrolysis and condensation of a tetraalkoxysilane and of a C7-C20-alkyltrialkoxysilane

Abstract

The invention thus relates to the cosmetic use of a siliceous material that may be obtained by hydrolysis and condensation, in the presence of water, of at least one tetraalkoxysilane of formula (I) below: Si(OR2)4 (I) and of an alkyltrialkoxysilane of formula (II) below: R.sub.1Si(OR.sub.2).sub.3 (H) in which: R.sub.1 denotes a C.sub.7 to C.sub.20 alkyl group, optionally interrupted in its chain with an O or S atom or with an NH group or a carbonyl group (CO), R.sub.2 denotes a C.sub.1-C.sub.4 alkyl group. Preferentially, the siliceous material is present in a composition comprising a cosmetically acceptable medium. The invention also relates to a cosmetic process for treating human body odour, in particular underarm odour and optionally human perspiration, which consists in applying to human keratin materials the said siliceous material or a composition containing the same in a cosmetically acceptable medium. The invention also relates to a composition characterized in that it comprises, in a cosmetically acceptable medium, at least the said siliceous material and at least one deodorant agent other than the said siliceous material and/or at least one antiperspirant active agent.

Claims

1. A cosmetic process for treating human body odour and optionally human perspiration, which comprises applying to human keratin materials a siliceous material that may be obtained by hydrolysis and condensation, in the presence of water, of at least one tetraalkoxysilane of formula (I) below:
Si(OR.sub.2).sub.4(I) and of an alkyltrialkoxysilane of formula (II) below:
R.sub.1Si(OR.sub.2).sub.3(II) in which: R.sub.1 denotes a linear or branched C.sub.7 to C.sub.20 alkyl group, optionally interrupted in its chain with an O or S atom or with an NH group or a carbonyl group (CO), R.sub.2 denotes a linear or branched C.sub.1-C.sub.4 alkyl group.

2. The cosmetic process according to claim 1, in which the said siliceous material is present in a composition comprising a cosmetically acceptable medium.

3. The cosmetic process according to claim 1, in which R.sub.1 represents a C.sub.8 to C.sub.18 alkyl group.

4. The cosmetic process according to claim 1, in which R.sub.2 represents a linear alkyl group comprising from 1 to 4 carbon.

5. The cosmetic process according to claim 1, in which compound (I) is chosen from tetraethoxysilane (TEOS) and tetramethoxysilane (TMOS).

6. The cosmetic process according to claim 1, in which compound (II) is chosen from n-octyltrimethoxysilane, n-dodecyltrimethoxysilane, n-octadecyltrimethoxysilane, n-octyltriethoxysilane, n-dodecyltriethoxysilane and n-octadecyltriethoxysilane, and mixtures thereof.

7. The cosmetic process according to claim 6, in which compound (II) is chosen from: n-dodecyltriethoxysilane n-octadecyltriethoxysilane n-octyltriethoxysilane.

8. The cosmetic process according to claim 1, in which the siliceous material may be obtained by hydrolysis and condensation, in the presence of water, of at least one tetraalkoxysilane of formula (I), of an alkyltrialkoxysilane of formula (II) and of at least one aminoalkyltrialkoxysilane of formula (III) below:
R.sub.3Si(OR.sub.4).sub.3(III) in which: R.sub.3 denotes a linear or branched, saturated or unsaturated C.sub.1-C.sub.6 hydrocarbon-based group or a cyclic C.sub.3-C.sub.5 hydrocarbon-based group, or denotes a C.sub.6-C.sub.9 aryl or C.sub.6-C.sub.9 aryloxy group, the said radicals being substituted with an amino group NH.sub.2 or NHR with R denoting a C.sub.1-C.sub.4 alkyl group, R.sub.4 denotes a linear or branched C.sub.1-C.sub.4 alkyl group.

9. The cosmetic process according to claim 8, in which R.sub.3 represents a C.sub.2-C.sub.4 hydrocarbon-based group substituted with an amino group NH.sub.2 or NHR with R denoting a linear or branched C.sub.1-C.sub.4 alkyl group.

10. The cosmetic process according to claim 8, in which R.sub.4 represents an ethyl group.

11. The cosmetic process according to claim 8, in which the compound of formula (III) is chosen from 3-aminopropyltriethoxysilane (APTES), 3-aminoethyltriethoxysilane (AETES), 3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-(m-aminophenoxy)propyltrimethoxysilane, p-aminophenyltrimethoxysilane and N-(2-aminoethylaminomethyl)phenethyltrimethoxysilane.

12. The cosmetic process according to claim 11, in which compound (III) is 3-aminopropyltriethoxysilane (APTES).

13. The cosmetic process according to claim 1, in which compounds (I) and (II) are used in a compound (I)/compound (II) weight ratio ranging from 0.9 to 100.

14. The cosmetic process according to claim 8, in which compounds (I) and (III) are used in a compound (I)/compound (III) weight ratio ranging from 0.9 to 100.

15. The cosmetic process according to claim 1, in which R.sub.1 represents an alkyl group chosen from n-octyl, n-decyl, n-dodecyl, n-tetradecyl, n-hexadecyl and n-octadecyl.

16. The cosmetic process according to claim 2, in which R.sub.1 represents a C.sub.8 to C.sub.18 alkyl group.

17. The cosmetic process according to claim 1, in which R.sub.2 represents an ethyl group.

18. The cosmetic process according to claim 3, in which R.sub.2 represents a linear alkyl group comprising from 1 to 4 carbon atoms.

19. The cosmetic process according to claim 1, which comprises applying said siliceous material to underarms.

Description

PREPARATION EXAMPLES

Example 1

(1) 20 g of tetraethoxysilane and 20 g of n-octyltriethoxysilane were added to 200 ml of ethanol. The mixture was stirred for 2 minutes. A mixture of 95 ml of water and 15 ml of 35% hydrochloric acid in water was added dropwise and the reaction mixture was stirred vigorously for 10 minutes. Next, 28% aqueous ammonia solution was added dropwise to bring the pH to 9. The reaction mixture was stirred vigorously for 24 hours and then poured into 2 litres of water, filtered and then washed three times with 500 ml of ethanol, and finally dried under vacuum at 70 C. for 1 hour. 10.1 g of a white powder were obtained.

Example 2

(2) 20.8 g of tetraethoxysilane and 2.08 g of n-octyltriethoxysilane were added to 350 ml of ethanol. The mixture was stirred for 2 minutes. A mixture of 50 ml of water and 10 ml of 35% hydrochloric acid in water was added dropwise and the reaction mixture was stirred vigorously for 10 minutes. Next, 28% aqueous ammonia solution was added dropwise to bring the pH to 9. The reaction mixture was stirred vigorously for 22 hours and then centrifuged at 4000 rpm for 4 minutes. The precipitate was triturated with 1 litre of ethanol and then centrifuged at 4000 rpm for 4 minutes. The precipitate was triturated and then centrifuged at 4000 rpm for 4 minutes with 200 ml of ethanol. The trituration and centrifugation cycle was repeated. The powder obtained was dried under vacuum and then poured into 500 ml of water. 10 ml of acetone were added. The mixture was stirred for 30 minutes and then filtered and the precipitate was washed with water (3 times 300 ml). The white powder was dried under vacuum at 80 C. for 24 hours. 4.1 g of a white powder were obtained.

Example 3

(3) The powder was prepared according to the procedure of Example 2, using 20 g of tetraethoxysilane, 2 g of n-octadecyltriethoxysilane and 350 ml of ethanol. 6 g of a white powder were obtained.

Example 4

(4) The powder was prepared according to the procedure of Example 2, using 18.2 g of tetraethoxysilane, 1.82 g of n-dodecyltriethoxysilane and 350 ml of ethanol. 6 g of a white powder were obtained.

Example 5

(5) 20 g of tetraethoxysilane, 20 g of 3-aminopropyltriethoxysilane and 20 g of n-octyltriethoxysilane were added to 300 ml of ethanol. The mixture was stirred for 2 minutes. A mixture of 120 ml of water and 15 ml of 35% hydrochloric acid was added dropwise and the reaction mixture was stirred vigorously for 30 minutes. Next, 28% aqueous ammonia solution was added dropwise to bring the pH to 9. The reaction mixture was stirred vigorously for 24 hours and then poured into 2 litres of water and centrifuged at 4000 rpm for 4 minutes. The precipitate was washed and then centrifuged three times with ethanol (500 ml) and then three times with water (500 ml). The powder obtained was dried under vacuum at 80 C. for 24 hours. 7 g of a white powder were obtained.

(6) The morphology of the particles of the powder obtained was characterized using an optical microscopy machine (Morphologi G3 from the company Malvern Instruments). 2 mg of the powder were sonicated in 1 ml of water for 5 minutes and then analysed. The particles have a mean diameter of 1.3 microns and a mean circularity of 0.76.

Example 6

(7) The powder was prepared according to the procedure of Example 5, using 20 g of tetraethoxysilane, 1 g of n-octyltriethoxysilane and 350 ml of ethanol. 7.4 g of a white powder were obtained.

(8) Comparative Tests of Deodorant Efficacy

(9) Two deodorant pastes according to the invention containing the siliceous material of Example 1 (formula C) and of Example 5 (formula D) and two deodorant pastes similar to paste C and to paste D, in which the siliceous material was replaced, respectively, with untreated silica (Sunsphere H51 (formula A) and with hydrophobic fumed silica Aerosil R972 (formula B), were prepared.

(10) The formulae are as follows (contents expressed as weight percentages):

(11) TABLE-US-00001 Formula Ingredients (INCI name) A B C D Polydimethylsiloxane (10 cSt) 37 37 37 37 (Xiameter PMX-200) Isopropyl palmitate 25 25 25 25 Isopropyl myristate 23 23 23 23 Dimethiconol 6 6 6 6 (Xiameter PMX1502) Polydimethylsiloxane (1000 cSt) 3 3 3 3 (Dow Corning silicone fluid SH 200) Unmodified silica 6 (Sunsphere H 51) Hydrophilic fumed silica 6 (Aerosil R 972) Siliceous material of Example 1 6 Siliceous material of Example 5 6

(12) The deodorant efficacy of each formula was evaluated according to the following protocol:

(13) 0.5 g of formula was applied to the surface of an armpit. The armpits were washed with toiletry soap and then rinsed and dried (towel) before applying the product. One armpit was not treated and served as a reference for the evaluation.

(14) After 24 hours, evaluations by direct sniff test of the intensity of the odour under the armpits were performed after application of a test composition and compared with the intensity of the odour under the untreated armpit.

(15) The deodorant efficacy was evaluated according to the following two criteria:

(16) The intensity of the odour on a scale from 1 to 10. 1 represents an imperceptible intensity and 10 represents an odour equivalent to that of the untreated armpit. The lower the value, the weaker the odour.

(17) The hedonic value on a scale from 1 to 10. 1 represents an odour that is as unpleasant as that under the untreated armpit and 10 represents an extremely pleasant odour. The higher the value, the more the unpleasantness decreases.

(18) Results

(19) TABLE-US-00002 Formula Odour intensity Hedonic value Formula A 9 3 (comparative) Formula B 6 4 (comparative) Formula C 2 6 (invention) Formula D 4 4 (invention)

(20) The results show that compositions C and D according to the invention make it possible to reduce efficiently the intensity of the odour. Composition C also gives a more pleasant odour.

Example 6

Anhydrous Deodorant Stick

(21) TABLE-US-00003 Amounts Ingredients (INCI name) (weight %) Cyclopentasiloxane 38 (DC 245 - Dow Corning) PPG-14 Butyl ether 10 (Ucon fluid AP Amerchol) Hydrogenated castor oil 4 (Cutina HR - Cognis) Stearyl alcohol 14 (Lorol C18 - Cognis) PEG-8 distearate 2 (Stearineries Dubois) C12-15 alkyl benzoate 15 (Finsolv TN - Witco) Siliceous material 17 according to one of Examples 1 to 6 Total 100
Procedure:

(22) The cyclopentasiloxane was heated to 65 C. The other ingredients were added (one by one), while keeping the temperature at 65-70 C. The whole was homogenized (transparent solution) for 15 minutes. The particles of siliceous material were added. The product was cooled to about 55 C. (a few degrees above the thickening point of the mixture) and poured into sticks. The sticks were placed at 4 C. for 30 minutes.

(23) The composition applied to the armpits reduces the odour caused by perspiration.

Example 7

Deodorant Emulsion (Roll-on)

(24) TABLE-US-00004 Ingredients (INCI Amounts Phase name) (weight %) A Siliceous material 10 according to one of Examples 1 to 6 B Steareth-21 2 (Brij 721 - ICI) Steareth-2 2 (Brij 72 - ICI) PPG-15 stearyl ether 1.5 (Arlamol E - ICI) Cyclopentasiloxane 3.5 (DC 245 - Dow Corning) C Water qs for 100
Procedure:

(25) Phases (B) and (C) were separately heated to 70 C. Phases (B) and (C) were mixed together with a Turrax blender for 5 minutes, and the mixture was then cooled to 55 C. with paddle stirring. Phase A was then added slowly with stirring. The mixture was homogenized for 1 to 3 minutes. The mixture was cooled to 35 C. with stirring. The composition applied to the armpits reduces the odour caused by perspiration.

Example 8

Deodorant and Antiperspirant Emulsion (Roll-on)

(26) TABLE-US-00005 Amounts Phase Ingredients (INCI name) (weight %) A Aluminium chlorhydrate 35 (50% solution) (Chlorhydrol 50% - USP) Siliceous material according 6 to one of Examples 1 to 6 B Steareth-21 2 (Brij 721 - ICI) Steareth-2 2 (Brij 72 - ICI) PPG-15 stearyl ether 1.5 (Arlamol E - ICI) Cyclopentasiloxane 3.5 (DC 245 - Dow Corning) C Water qs for 100
Procedure:

(27) Phases (B) and (C) were separately heated to 70 C. Phases (B) and (C) were mixed together with a Turrax blender for 5 minutes, and the mixture was then cooled to 55 C. with paddle stirring. Phase A was then added slowly with stirring. The mixture was homogenized for 1 to 3 minutes. The mixture was cooled to 35 C. with stirring.

(28) The composition applied to the armpits reduces the odour caused by perspiration.

Example 9

Deodorant Paste

(29) TABLE-US-00006 Amounts Ingredients (INCI name) (weight %) Triethyl citrate 7 (Citroflex 2 - Reilly Chemicals) Isopropyl palmitate (Cognis) 6 Siliceous material according to 17.5 one of Examples 1 to 6 Cyclomethicone 60.5 (Dow Corning 245 Fluid) Cyclopentasiloxane (and) 9 Dimethiconol (Dow Corning 1501 Fluid)
Procedure:

(30) The particles of siliceous material were dispersed in the mixture of the other starting materials using a paddle. A homogeneous paste was obtained.

(31) The composition applied to the armpits reduces the odour caused by perspiration.

Example 10

Aerosol

(32) TABLE-US-00007 Amounts Phase Ingredients (INCI name) (weight %) A Triethyl citrate 1.05 (Citroflex 2 - Reilly Chemicals) Stearalkonium bentonite 0.23 Isopropyl palmitate (Cognis) 0.9 Hydrophobic modified silica 2.625 according to one of Examples 1 to 6 Cyclomethicone 9.075 (Dow Corning 245 Fluid) Cyclopentasiloxane (and) 1.35 Dimethiconol (Dow Corning 1501 Fluid) B Isobutane 85
Procedure:

(33) The particles of siliceous material were dispersed in the mixture of the other starting materials constituting phase A, using a paddle. The mixture was pressurized with isobutane in an aerosol can.

(34) The composition applied to the armpits reduces the odour caused by perspiration.