Uses of zeolite powder in cosmetic formulations

Abstract

The present invention relates to a synthetic lipophilic zeolite powder for the manufacture of cosmetic compositions.

Description

Technology Field

[0001] The present invention relates to the use of zeolite powder in the field of cosmetic formulations, particularly for the manufacture of cosmetic compositions. Background Technology

[0002] In the field of cosmetic formulations, one of the key requirements is the development of active formulations that can simultaneously ensure excellent spreadability and adhesion to the skin.

[0003] To achieve the expected user experience regarding the texture of the formulation, various approaches have been applied depending on the different matrices, formulations, and end applications.

[0004] For example, in the field of non-aqueous compositions, JP87158 / 1998 and 194327 / 1998 reported on the possibility of incorporating a thickening polymer soluble in polyhydric alcohols or silica gel to facilitate the application of polyhydric alcohols to the skin.

[0005] However, considering the disclosures reported above, the use of a single thickening polymer necessitates the use of large amounts of such compounds to achieve the desired texture of the formulation; therefore, one of the main solutions to this is the possibility of using fine particles of inorganic compounds, as reported in European patent application EP0974340.

[0006] In the field of filler compositions added to cosmetic compositions to adjust specific properties such as viscosity, the availability of various classes of compounds, such as inorganic powders—typically titanium dioxide, calcium carbonate, zinc oxide, silica compounds, clay, mica, and zeolites—as reported, for example, in international patent application WO2022146700, or organic powders and beads such as polyethylene, polymethyl methacrylate, polyamide / nylon-12, polyethylene terephthalate, polyurethane, and polysiloxane (commonly defined as microplastics and nanoplastics), has been known in the relevant art.

[0007] Zeolites can be used for various purposes, such as utilizing their carrier properties as disclosed in patent application US20200179243 or EP1971309, utilizing their ability to generate heat when a specific formulation comes into contact with water as reported in European patent application EP1186286, or adjusting the viscosity of cosmetic formulations to improve smooth texture and spreadability (see, for example, Japanese patent application JP1985218305).

[0008] However, as also reported in the cited prior art, in the case of cosmetic formulations containing zeolites, silica, or various texturing fillers, it has been reported that a wide particle size distribution, such as nanometer particles, is typically used for easier dispersibility.

[0009] In recent years, pollution of the ocean environment and marine ecosystems by microplastics and nanoplastics has become a major issue. In 2019, the European Commission (EC) [included] a series of policy initiatives to make the European Union climate neutral by 2050 European Green Deal ( European Green Deal)" was announced, and in this regard, the EC instructed the European Chemicals Agency (ECHA) regarding "in products such as cosmetics, detergents, and agricultural products" Intentionally added microplastics They requested that a proposal be prepared to restrict it.

[0010] Furthermore, the adoption of certain classes of compounds, such as silica and talc, has gradually decreased due to their toxicity to humans and the environment.

[0011] Therefore, there is increasing demand for cosmetic products that contain reduced amounts or no plastic nano-fillers, according to the European Commission’s definition of nanomaterials, which refers to materials in which 50% of the particles in a number-weighted particle size distribution have a minimum dimension of less than 100 nm.

[0012] Accordingly, the object of the present invention is to provide a cosmetic formulation that does not contain any plastic nano-fillers but has spreadability and adhesion to the skin that is the same as or better than that of cosmetic formulations known in the art. After extensive experimentation, the inventors of the present invention have discovered that the texture of a cosmetic composition can be improved without using nano-fillers by using zeolite powder. Specific details for implementing the invention

[0013] terminology

[0014] All percentages, parts, and ratios are based on the total weight of the composition of the present invention, unless otherwise specified. The term " weight percentage " or " Weight basis "It may also be represented as "wt%" in this document.

[0015] At this institution, " including " implies that other ingredients may be added. The above term is the term " accomplished It encompasses ".

[0016] Detailed description of the invention

[0017] In particular, the inventors have surprisingly discovered that by using a synthetic lipophilic zeolite having well-defined technical characteristics in a cosmetic formulation, it is possible to obtain excellent spreadability and adhesion to the skin while avoiding unpleasant color and odor caused by the starting material.

[0018] Accordingly, the present invention relates to a zeolite powder, more preferably a synthetic lipophilic zeolite powder, as better defined below, for a cosmetic formulation or composition that does not contain any plastic nano-filler.

[0019] The adjective lipophilicity refers to a substance that can be uniformly dispersed on an oily or fatty phase without the formation of deposits or precipitates.

[0020] Accordingly, the object of the present invention is the use of a zeolite powder for the manufacture of cosmetic formulations, preferably comprising at least a synthetic lipophilic zeolite, more preferably a Linde type A (LTA) zeolite, a ZSM-5 type zeolite, or a mixture thereof, as defined in the appended claim 1, wherein the zeolite has a Si / Al ratio of 1.0 to 50, preferably 1.0 to 25, a pore size of 3.0 to 14 Å, and 1700 m 2 / cm 3 Accessible area per unit volume (i.e., accessible specific area) of less than (±1%) and 100 to 700 kg / m² 3 It features loose bulk density (LBD) values ​​included in it.

[0021] Loose bulk density (LBD) is defined as the mass of an uncompressed material sample divided by the volume occupied by the sample, in kg / m³ 3It is measured in units of. Depending on the particle shape and size, the obtained LBD can vary significantly and, surprisingly, it has been revealed by the inventors that this can affect the texture and viscosity of the final cosmetic product.

[0022] It is important to emphasize that the use of synthetic zeolite characterized by an amount of Fe (II) / (III) of less than 0.5 weight% according to the present invention brings about various advantages in cosmetic applications.

[0023] In particular, unlike "natural zeolites," which are typically characterized by the presence of common contaminants and impurities such as Fe2O3 or other metal oxides originating from natural sources, synthetic zeolites are in a purer form, and as a result, no additional purification step is required during formulation. Furthermore, the material does not possess the characteristic odor and color of the related natural form or other synthetic zeolites, and consequently offers advantages in the formulation of cosmetic or skincare products where a specific color or odor may be required, or where neither may be present.

[0024] The above zeolite preferably contains sodium, potassium, calcium, or hydrogen as a counter-ion at the ion exchange sites of the framework structure.

[0025] In the field of filler particles, the use of surface modification can be an important factor in controlling surface properties and their related behavior when added to formulations, powder mixtures, rubbers, and other composite systems.

[0026] Accordingly, in a preferred embodiment, the zeolite is characterized by surface functionalization achieved through a hydrolysis-condensation reaction with a silane suitable for use in cosmetic compositions, such as octyl trimethoxysilane or caprylyl triethoxysilane.

[0027] According to the above embodiment, the amount of silane is 0.4 to 15 weight percent of the total weight of the zeolite.

[0028] An additional feature to be considered to improve the texture of a cosmetic formulation is the oil absorption rate of the added filler. Accordingly, the zeolite disclosed herein may further be characterized by an oil absorption value contained in 10 to 160 ml / 100g of powder, preferably 20 to 100 ml / 100g, as measured by ASTM D281 analysis, which is an accredited oil absorption method by spatula blasting.

[0029] In a preferred embodiment, the zeolite comprises X contained in the range of 0.1 μm to 30 μm, preferably in the range of 0.2 to 10 μm. 90 Value and 200 to 900 m 2 / g, preferably 300 to 600 m 2 It is characterized by the surface area contained in / g.

[0030] X indicating the spherical diameter at which 90% of the sample particles fall within a given range based on volume 90 The value is determined using an analysis protocol defined according to the ISO 13320:2020 method.

[0031] The surface area is determined by the physisorption of a suitable gas (CO2 or Ar).

[0032] The inventors have discovered that, in order to obtain optimal results in terms of the desired characteristics of a cosmetic formulation, zeolite powder should be added to a cosmetic composition in an amount of 1 to 75 weight percent based on the total weight of the cosmetic composition; preferably, in an amount of 1 to 20 weight percent for skin care products and in an amount of 20 to 75 weight percent for makeup products.

[0033] In fact, it is finally disclosed that the synthetic lipophilic zeolite powder according to the present invention is suitable for improving the texture performance of skin care or makeup compositions.

[0034] Skin care or makeup compositions are generally known to those skilled in the art, and these are preferably formulations suitable for topical application in the form of gels, creams, ointments, powders, emulsions, etc.

[0035] Examples

[0036] The present invention will now be described in more detail with reference to the following non-limiting embodiments. Variations or modifications of the embodiments illustrated herein that are obvious to those skilled in the art are encompassed by the appended claims.

[0037] Table 1 reports some embodiments according to the present invention, corresponding embodiments, and related features required for use in cosmetic compositions. In particular, since the color of the active ingredient is a major aspect in the formulation of cosmetic compositions, the results of a colorimetric test that enables the evaluation of the intrinsic color of the zeolite are very important.

[0038] The color of zeolite powder is visualized and quantified using the CIELAB color space. A three-dimensional color space is constructed from three mutually perpendicular axes.

[0039] The L-axis values ​​provide brightness: white objects have an L value of 100, and black objects have an L value of 0. The a-axis is the green-to-red axis, and the b-axis changes from blue (-b) to yellow (+b).

[0040] Accordingly, each color is represented by a color point (L, a, b) in color space; L, a, and b are the color coordinates of the color point.

[0041] For the compressed powder contained in a quartz sample container, a test is performed to record the full visible spectrum using a state-of-the-art UV-visible spectrometer equipped with an integrating sphere of reflection mode. Subsequently, the L, a, and b parameters are calculated from the obtained spectrum according to the CIELAB model.

[0042]

[0043] Table 1

[0044] For specific applications in the cosmetics field, the color of the starting material, particularly a yellowish tint, must be avoided, and thus a combination of L, a, and b parameters corresponding to a white and crystalline powder is required. In particular, to ensure this, the yellow tint of the zeolite must be avoided with a b value of less than 1.0.

[0045] Accordingly, it is evident that while the zeolites disclosed in the present invention (samples S1-S2) guarantee the above characteristics, natural zeolites, such as heulandite-type zeolites (HEU) (see C1), synthetic zeolites (C4) having a Si / Al ratio greater than 50, or synthetic zeolites (C2, C3, C5) having different counter-ions do not satisfy the required colorimetric characteristics.

[0046] An additional aspect to be evaluated in the field of cosmetic ingredients is their associated odor, which must be neutralized for the proper formulation of the final composition.

[0047] Accordingly, an appropriate amount of sample is placed in a headspace vial and processed at 80°C, and then an odor test is performed by injecting the headspace gas into a gas chromatograph equipped with a mass spectrum detector. Subsequently, the major VOC peaks are quantified as ethyl acetate using appropriate corrections, and the total amount of VOC from each sample is calculated.

[0048] The results related to this are reported in Table 2, and specifically, while natural zeolites (C1) or synthetic FAU-type zeolites (C6-C7) with different Si / Al ratios exhibit VOC emissions that make them unsuitable for required applications, the zeolites (S1-S2) of the present invention are found to exhibit no VOC emissions at all, and thus are texturing starting materials that simultaneously satisfy the required characteristics of being colorless and odorless.

[0049]

[0050] Table 2

Claims

Claim 1 A method of using zeolite powder to texture a cosmetic composition, comprising incorporating zeolite powder into a cosmetic composition, wherein the zeolite powder comprises ZSM-5 type zeolite, Linde type A (LTA) zeolite, or a mixture thereof, and is characterized by the following: a) a Si / Al ratio contained in the range of 1.0 to 25, b) a pore size contained in the range of 3.0 to 14 Å and 1700 m 2 / cm 3 Accessible non-area less than, c) 100 to 700 kg / m² 3 The loose bulk density (LBD) value contained therein, d) an amount of Fe(II) / (III) of less than 0.5 wt%, and e) sodium, potassium, calcium, or hydrogen as a counter-ion at the ion exchange sites of the framework structure. Claim 2 A method according to claim 1, wherein the zeolite has surface functionalization achieved through a hydrolysis-condensation reaction with a silane suitable for use in a cosmetic composition. Claim 3 A method according to paragraph 2, wherein the amount of silane is 0.4 to 15 weight percent of the total weight of the zeolite. Claim 4 A method according to claim 1, characterized in that the zeolite has an oil absorption value of 10 to 160 ml / 100g contained in the powder, as measured by ASTM D281 analysis. Claim 5 In claim 1, the zeolite contains X contained in the range of 0.1 to 30 μm, measured according to the ISO 13320:2020 method. 90 A method characterized by a value. Claim 6 In claim 1, the zeolite is 200 to 900 m 2 A method characterized by a surface area included in / g. Claim 7 A method according to claim 1, wherein the zeolite is combined in an amount of 1 to 75 weight percent based on the total weight of the cosmetic composition. Claim 8 A method according to claim 1, wherein the cosmetic composition is a skin care composition. Claim 9 A method according to claim 1, wherein the cosmetic composition is a makeup composition. Claim 10 delete

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