FR2877569A1 - Pigment wetting agent for cosmetics comprises mixture of monoesters and diesters of butylene glycol and lauric acid - Google Patents

Abstract

The mixtures contains 40-60 wt % of monoesters and the lauric acid (50-60 wt %). An independent claim is also included for dispersion of the above mixture.

Description

WETTING AGENT BASED ON A MIXTURE OF MONOESTERS AND DIESTERS OF

BUTYLENE GLYCOL

  The invention relates to a novel wetting agent intended to be used in particular but without limitation, in the field of cosmetics, for its ability to wet lipophilic pigments. This property is particularly sought after in compositions requiring dispersion of the pigments in an oily phase. This is particularly the case of solar products and make-up products. It is also useful in cleansing products to promote the fixation and the removal of pigments on the skin.

  Many products are proposed for their ability to wet pigments. In particular, C12-C15 alkyl benzoate and isopropyl palmitate are known. Also used for this same function certain triglycerides, such as, castor oil or tricaprylocaprate glycerol.

  EP-A-792 633 discloses a powdery anhydrous composition comprising a binder or wetting agent. In practice, the binding agent is an ester, liquid at room temperature, comprising at least two hydrocarbon chains, each having at least ten carbon atoms. The ester in question does not have a hydroxyl group. A preferred agent is, for example, glycerol triisostearate.

  All of the wetting agents known to the Applicant, as previously mentioned, have a number of disadvantages. First, the necessary amount of raw material for wetting a given pigment remains relatively high. It influences the formulation in terms of cost, composition and sensory properties. The high viscosity of certain raw materials, such as castor oil, at room temperature or pigment dispersions obtained make them difficult to handle products. Finally, the known wetting agents give the final composition in which they are introduced, a sometimes greasy feel.

  In other words, there is a need, particularly for the cosmetic market, for products having a wetting power which does not have the above disadvantages.

  In the course of his research, the Applicant has discovered that mixtures of monoesters and butylene glycol diesters, for example butylene glycol cocoate, have a wetting power higher than that of known agents.

  Butylene glycol cocoate (CBG) is a known product already used as a cosmetic ingredient in a composition marketed by the Applicant under the name EMULFREE CBG. More specifically, this composition corresponds to the combination of CBG with isostearyl alcohol and ethylcellulose. In practice, EMULFREE CBG is used as a stabilizer for the oil phase in oil-in-water emulsions. The role of butylene glycol cocoate in this composition is confined to the solubilization function of the gelling polymer, namely ethylcellulose. In other words and contrary to the invention, butylene glycol cocoate is not likely to be mixed directly with fillers but is necessarily used in combination with a fatty alcohol (isostearyl alcohol) in the presence of a polymer (ethylcellulose).

  The mixture of the invention is clearly distinguished not only in terms of function, but also in terms of structure, of the butylene glycol esters described in EP-A-860 164. In fact, this document describes the combination of a chemical UV filter with only butylene glycol diesters with fatty acids containing from 6 to 12 carbon atoms. Not only does the composition contain no monoesters, but it is also used as a chemical filter solubilizing agent and not as a wetting agent.

  JP 57072907 discloses a makeup remover based on either monoesters or diesters containing from 17 to 36 carbon atoms. Again, the mixture of monoesters and diesters is not contemplated. Moreover, in the case of diesters, it is diacid esters, that is to say an acid esterified with two alcohols and not a diol esterified with two acids, as is the case in the invention. The monoesters are, for their part, derived from a monoacid with a monoalcohol and not from a monoester of a diol.

  EP-A-651 990 discloses the use of esters in a makeup removing composition. According to this document, the esters used are again either monohydric esters or diesters. In practice, they are obtained from an alcohol containing 1 to 17 carbon atoms and a fatty acid containing from 3 to 18 carbon atoms. In addition, they must have no free hydroxyl group.

  EP-A-1,230,910 discloses an oil-in-water emulsion containing pigments and whose oily phase contains the only butylene glycol caprylocaprate diesters.

  In other words, nothing in the state of the art known to the Applicant discloses the idea of using a mixture of monoesters and diesters of butylene glycol, as wetting agent.

  Accordingly, the invention relates to a lipophilic pigment wetting agent which is characterized by containing a mixture of monoesters and diesters of butylene glycol and fatty acids.

  According to a first characteristic, the fatty acids are chosen from the group comprising C6 to C22 fatty acids. Of course, monoesters and diesters can be obtained from different and / or identical fatty acids, saturated and / or unsaturated.

  In a particular embodiment, the wetting agent of the invention is obtained by esterification of butylene glycol with all or part of fatty acids of natural origin, in particular derived from vegetable oil.

  The Applicant has found that good results are obtained when the lauric acid represented at least 40%, advantageously from 50 to 60% by weight of the fatty acids. Such a distribution is found in coconut oil or palm kernel oil.

  Therefore and according to a preferred embodiment, the wetting agent is obtained by esterification of butylene glycol and a C12 to C18 fatty acid fraction derived from coconut oil.

  According to another characteristic, the monoesters represent between 10 and 90%, advantageously between 40 and 60% by weight of the mixture monoesters / diesters.

  The described wetting agent is of technological interest because it facilitates the formulation process. Indeed, it is used in lower proportion for a given amount of pigments compared to conventional wetting agents. It provides a lower viscosity of the dispersions. They are therefore easier to use than those obtained with conventional wetting agents. Finally, the lesser amount of wetting agent of the invention to be used makes it possible to leave room for incorporating texture or touching agents in the formula. In addition, this wetting agent provides a non-greasy dry touch.

  As already stated, this product can be used in all the cosmetic or dermatological compositions comprising lipophilic pigments thereby, by virtue of its wetting properties, to improve the dispersion thereof in the oily phase, and to optimize the spreading of the composition on the skin. Of course, the proportion of wetting agent in the composition will depend on the nature and quantity of the pigments.

  In particular, the use of the agent of the invention will be more particularly advantageous in products containing pigments such as sun products, makeup products (foundation, mascara, lipstick, etc.), creams for baby incorporating pigments or products for removing pigments such as make-up removal products.

  Compositions in which the wetting agent of the invention can be introduced may be in the form of water-in-oil, oil-in-water, multiple, or anhydrous emulsions.

  It is also possible to propose formulations corresponding to dispersions based solely on lipophilic pigments and the wetting agent of the invention. It is possible to incorporate a polymeric stabilizing agent which makes it possible to avoid the sedimentation of the pigments. The dispersion will remain smooth and homogeneous. This dispersion may also contain other lipophilic phases of oil or ester type. This dispersion can then be incorporated as such into the more complex cosmetic composition.

  The invention and the advantages which result therefrom will emerge from the following examples of embodiment, in support of the appended figures.

  FIGS. 1a, b, c, d are curves representing the viscosity of a dispersion formulated with the wetting agent of the invention or an agent of the prior art (C 1 -C 15 alkyl benzoate or ricin) based on an increasing amount of pigments.

  Figures 2 are photographs taken under optical microscope (x400 magnification) of a pigmented emulsion formulated with CBG (Figure 2A) or with C12-C15 alkyl benzoate (Figure 2B).

  EXAMPLE 1 Wetting Power and Viscosity with Respect to Various Wetting Agents 1. Evaluation of the wetting power The wetting power of an oil or a solvent is the minimum amount of oil or solvent necessary to form with a powder or a paste smooth without cracking during spreading.

  It is expressed in grams of oil necessary to wet 100g of pigment. The lower the amount of oil to use, the better the wetting power.

  2 Wetting power results compared to conventional wetting agents 2. a Wetting power TiO2 TiO2 ZnO pigments Blue Brown Black Red Yellow Wetting agent PW * WZ ultramarine W8802 * W9814 * W3801 * covalac 877 * Rating ** W 6803 * W 1501 * Cocoate Butylene Glycol 114 21 60 62 25 37 27 110 C12 / C15 alkyl benzoate 174 32 99 79 47 63 59 162 Castor oil 27 88 31 46 39 97 Isopropyl palmitate 26 70 42 56 49 132 Caprylic / Capric 29 80 44 57 54 147 Triglycerides Marketed LCW ** Marketed BASF Table 1: Amount of wetting agent, in g, required for the dispersion of 100 g of pigment As shown in the table, butylene glycol cocoate gives better results. In addition, even if castor oil gives a result that may seem satisfactory, in some cases, its high viscosity makes it difficult to use the product.

  2.b.Viscosity of dispersions FIGS. 1a, b, c, d, are curves representing the viscosity of a dispersion formulated with the wetting agent of the invention or an agent of the prior art (alkyl benzoate C12 to C15 or castor oil) as a function of an increasing amount of pigments.

  The dispersions obtained with CBG are more fluid than with C12-C15 alkyl benzoate or castor oil. Thus for the same composition, a dispersion in the CBG will be easier to use.

  3. Wetting Performance Compared to a Butylene Glycol Diester igments TiO2 ZnO Blue Yellow Brown Black Red Wetting Agents WZ Overseas Covalac W8802 W9814 W3801 877 Od W 6803 W 1501 Butylene Glycol Cocoate 21 60 62 110 25 37 27 Dicaprylate / Dicaprate Table 2: Amount of wetting agent, in g, required for the dispersion of 100 g of pigment As shown in the table, the wetting agent of the invention is more effective than the product described in the prior art (EP-A-1,230,910), used as a filter solubilizer.

  Conclusion: the product of the invention mono + diester is more effective than a diester 4. Wetting power result with respect to glycol esters (monoesters and diesters) elements TiO2 Blue Wetting agents W 877 ultramarine W 6803 Coconut of Butylene Glycol 21 62 Propylene Glycol Caprylate 26 72 Propylene Glycol Laurate 23 70 Dicaprylate / Propylene Glycol Dicaprate 28 76 Propylene Glycol Isostearate 23 73 Conclusion: Regardless of the nature of the fat chain length (giving a liquid product), the CBG gives a better result than the propylene glycol esters (diesters or mono / diester mixture) or the butylene glycol diesters.

  Example 2: Evaluation in formulation. Measurement of Sun Protection Factor 10 (SPF) The excellent wetting power demonstrated for CBG finds an interesting application in solar products containing mineral filters such as titanium dioxide and zinc oxide. Indeed a better wetting of these pigments in formulation allows better dispersion and better spreading of these on the skin, so better sun protection.

  Two oil-in-water emulsions were formulated with respectively CBG (A) and C12-C15 alkyl benzoate (B).

A B

  Phase I Emulium 22 4 4 Mineral Oil 2 2 Dimethicone 2 2 Butylene Glycol Cocoate 23 - C12-C15 alkyl benzoate - 23 Titanium Dioxide 10 10 Zinc Oxide 5 5 Preservative qs qs Phase II Demineralized water Qs 100 Qs 100 Xanthan gum 0.4 0.4 Microcrystalline Cellulose and Cellulose Gum 1 1 Glycerin 3 FIGS. 2 are photographs taken under an optical microscope (magnification × 400) of a pigmented emulsion formulated with CBG (FIG. 2A) or with C12 alkyl benzoate. C15 (Figure 2B).

  There is a big difference in the dispersion of the pigments. Indeed, in formula A containing CBG (FIG. 2A), the pigments are well dispersed, whereas in formula B containing the C12-C15 alkyl benzoate (FIG. 2B) the pigments appear in the form of aggregates.

  The sun protection factors were measured in vivo according to the COLIPA recommendations on 5 volunteers: Formula A Formula B 11.5 + 1-2.9 8.7 +/- 2.8 These results show significantly (p <0.05) that the use CBG in place of the C12-C15 alkyl benzoate provides a higher sun protection factor (SPF).

  On the other hand at the sensory level, formula A is significantly easier to spread on the skin than Formula B.

Example 3: Formulas

  Below are some examples of formulas that can be made with CBG-containing pigment dispersions in several applications.

  1. Solar Sunscreen water in oil: Ingredients% m / m Phase I Plurol Diisostearic 5 Butylene Glycol Cocoate 10 Isohexadecane 10 Dimethicone and Dimethiconol 2 Titanium Dioxide 10 Preservative qs Phase II Demineralized water Qs 100 MgSO4, 7H2O 0.5 NaCl 0.5 Glycerin 3 The FPS of the formula is measured at 21 in vivo 2. Makeup Foundation Ingredients% m / m Phase I Hydrolactol 70 5 Cetostearyl alcohol 2 Cetyl alcohol 1 Dimethicone 4 Cyclomethicone 2 Isostearyl isostearate 5 Preservative qs Phase II Demineralized water Qs 100 Microcrystalline Cellulose and 1.5 Cellulose Gum Xanthan Gum 0.4 EDTA, Na2 0.1 Phase III Butylene Glycol Cocoate 3 Titanium Dioxide 6.6 Yellow Iron Oxide 1.2 Brown Pigment 0.25 Red Iron Oxide 0.53 Black Iron Oxide 0.11 Mascara Ingredients% m / m Phase I Apifil 8 Compritol 888 2 Dimethicone 2 Phase II Demineralized water Qs 100 Carbomer 0.2 Phase III 10% Sodium 0.4 Phase IV Butylene Glycol Cocoate 8 Black Iron Oxide 12 Talc 4 Phase V PVP / Dimethylaminoethyl 10 methacrylate copolymer Preservative Qs 3. Lipstick Ingredients% m / m Lipstick Base CB8047 (Gattefossé) 73.35 Candelilla Wax 4 Ozokerite 2 Ethoxydiglycol Behenate 8 Butylene Glycol Cocoate 8 Covalac Yellow W1501 2 Ruby Covanor W4605 1 Titanium Dioxide W877 1.65 4. Cleansing Cleansing Milk Ingredients% m / m Phase I Deionized Water Qsp 100 Acrylic Polymer 0.3 Xanthan Gum 0.2 Preservative qs Phase II Butylene Glycol Cocoate 10 Cyclomethicone 2 Phase III Soda at 10% 0.6 5. Baby Products Baby Cream with Zinc Oxide Ingredients% m / m Phase I Plurol Diisostearic 5 Mineral Oil 15 Butylene Glycol Cocoate 7 Zinc Oxide 15 Compritol 888 5 Preservative Qs Phase II Deionized Water Qs 100 NaCl 0.5 MgSO4,7H20 0.5 Phase III Calendula officinalis extract 2 Perfume qs

Claims (10)

  1 / wetting agent for lipophilic pigments, characterized in that it contains a mixture of monoesters and diesters of butylene glycol and fatty acids.   2 / wetting agent according to claim 1, characterized in that the fatty acids are chosen from the group comprising C6C22 fatty acids.   3 / wetting agent according to one of the preceding claims, characterized in that the monoesters and diesters are obtained from saturated and / or unsaturated fatty acids, different and / or identical.   4 / wetting agent according to one of the preceding claims, characterized in that it is obtained by esterification of butylene glycol with all or part of naturally occurring fatty acids and in particular derived from vegetable oil.   5 / wetting agent according to one of the preceding claims, characterized in that the lauric acid is at least 40%, preferably 50 to 60% by weight of fatty acids.   6 / wetting agent according to one of the preceding claims, characterized in that it is obtained by esterification of butylene glycol with a C12 to C18 fatty acid fraction from coconut oil.   7 / wetting agent according to one of the preceding claims, characterized in that the monoesters represent between 10 and 90%, preferably between 40 and 60% by weight of the mixture monoesters / diesters.   8 / dispersion consisting of the mixture of monoesters and diesters of butylene glycol and fatty acids according to one of claims 1 to 7, and pigments.   9 / Dispersion consisting of the mixture of monoesters and diesters of butylene glycol and fatty acids according to one of claims 1 to 7, pigments and a stabilizing agent.   10 / Dispersion consisting of the mixture of monoesters and diesters of butylene glycol and fatty acids according to one of claims 1 to 7, pigments, at least one lipophilic phase and optionally a stabilizing agent.