CELLULOSE NANOCRYSTAL EFFECT PIGMENTS FOR COSMETIC APPLICATIONS

Abstract

The present invention relates to a cosmetic composition including an organic effect pigment. The organic effect pigment includes cellulose nanocrystal flakes which have an average size in the range of from 10 to 6500 micrometers.

Claims

1. A cosmetic composition comprising an organic effect pigment, wherein the organic effect pigment comprises cellulose nanocrystal flakes, wherein the cellulose nanocrystal flakes have an average size in the range of from 10 to 6500 micrometers.

2. The cosmetic composition of claim 1 comprising the organic effect pigment in an amount in the range of from 0.025 to 99 weight-%, based on the total weight of the cosmetic composition.

3. The cosmetic composition of claim 1, further comprising a liquid phase, wherein the cellulose nanocrystal flakes form a mixture with said liquid phase, wherein the liquid phase preferably contains a cosmetically acceptable liquid medium.

4. The cosmetic composition of claim 3, wherein at a temperature of the composition in the range of from 5 to 70° C., from 99 to 100 weight-% of the cellulose nanocrystal flakes are dispersed in the cosmetically acceptable liquid medium.

5. The cosmetic composition of claim 3, wherein in the cosmetic composition, the color of the cellulose nanocrystal flakes in the visible spectrum depends on the dielectric constant of the liquid phase.

6. The cosmetic composition of claim 3, wherein the liquid phase is an aqueous phase or an anhydrous phase.

7. The cosmetic composition of claim 1, further comprising at least one additional cosmetically acceptable component other than the organic effect pigment.

8. A process for preparing a cosmetic composition, comprising (i) providing an aqueous dispersion comprising water and cellulose nanocrystals; (ii) subjecting the aqueous suspension provided according to (i) to drying conditions, obtaining a film; and fragmenting said film into flakes, obtaining an organic effect pigment; (iii) preparing a mixture comprising the organic effect pigment obtained from (ii) and a liquid phase, and optionally at least one additional cosmetically acceptable component other than the organic effect pigment obtained from (ii), thereby obtaining the cosmetic composition.

9. The process of claim 8, wherein the aqueous dispersion provided according to (i) is an acidic aqueous dispersion, wherein the aqueous phase of the dispersion has a pH in the range of from 0 to 5.

10. The process of claim 8, further comprising preparing the cellulose nanocrystals according to (i), by (a) isolating cellulose from a natural source of cellulose; and (b) hydrolyzing with an acid, the isolated cellulose obtained in (a), thereby obtaining the cellulose nanocrystals.

11. The process of claim 8, wherein the aqueous dispersion provided according to (i) additionally comprises a cosmetically acceptable dye.

12. The process of claim 8, wherein the liquid phase in the mixture prepared according to (iii) has a dielectric constant in the range of from 1 to 100.

13. The process of claim 8, wherein the liquid phase in the mixture prepared in (iii) is an aqueous phase or an anhydrous phase.

14. The process of claim 8, wherein preparing a mixture comprising the organic effect pigment obtained from (ii), and the liquid phase, according to (iii) comprises mixing the organic effect pigment and the liquid phase at a temperature in the range of from 15 to 30° C.

15. A method for preparing two or more cosmetic compositions, said cosmetic compositions comprising the same organic effect pigment, which comprises cellulose nanocrystal flakes, as coloring agent and having different flake colors in the visible range, the method comprising a) providing a first cosmetic composition comprising an organic effect pigment, which comprises cellulose nanocrystal flakes, as coloring agent and having different flake colors in the visible range; b) providing a second cosmetic composition comprising the same organic effect pigment as the first cosmetic composition; and c) adjusting the dielectric constant of the liquid phase of said cosmetic compositions such that the dielectric constant of the liquid phase of the first cosmetic composition is not equal to the dielectric constant of the liquid phase of the second cosmetic composition, obtaining cosmetic compositions having different flake colors in the visible range.

16. (canceled)

17. (canceled)

18. A kit for preparing two cosmetic compositions having different flake colors in the visible range, comprising: (1) one organic effect pigment, wherein the organic effect pigment comprises cellulose nanocrystal flakes, wherein the cellulose nanocrystal flakes have an average size in the range of from 10 to 6500 micrometers; (2) a first cosmetic composition; and (3) a second cosmetic composition other than the first cosmetic composition.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0222] FIG. 1 is a scheme illustrating the step for producing iridescent films.

[0223] FIG. 2a is a picture of the CNC flakes in the cosmetic composition 2.1.

[0224] FIG. 2b is a microscope image of the CNC flakes in the cosmetic composition 2.1 (magnification: 5×, 200 um scale bar).

[0225] FIG. 3a is a picture of the CNC flakes in the cosmetic composition 2.2.

[0226] FIG. 3b is a microscope image of the CNC flakes in the cosmetic composition 2.2 (magnification: 5×, 200 um scale bar).

[0227] FIG. 4a is a picture of the CNC flakes in the cosmetic composition 2.3.

[0228] FIG. 4b is a microscope image of the CNC flakes in the cosmetic composition 2.3 (magnification: 5×, 200 um scale bar).

[0229] FIG. 5 is a picture of the CNC flakes in the cosmetic compositions 2.4, 2.5 and 2.6.

[0230] FIG. 6 is a picture of the pigment 1 in the cosmetic composition C.1, C.4 and C.7.

[0231] FIG. 7 is a picture of the pigment 2 in the cosmetic composition C.2, C.5 and C.8.

[0232] FIG. 8 is a picture of the pigment 3 in the cosmetic composition C.3, C.6 and C.9.

[0233] Cited Literature [0234] WO 2018/100065 A1 [0235] JP 2017-048181 A [0236] US2019/0002700 A1 [0237] WO 2012/112541 A2