WO2019155097A1

WO2019155097A1 - Method for obtaining clay nanoparticles and product made from said clay nanoparticles

Info

Publication number: WO2019155097A1
Application number: PCT/ES2018/070093
Authority: WO
Inventors: Cayetano MONTESA GIMENO; Marco Antonio Montesa Gimeno
Original assignee: Montesa Productos Cerámicos, S.A.
Priority date: 2018-02-09
Filing date: 2018-02-09
Publication date: 2019-08-15

Abstract

The invention relates to a method for obtaining clay nanoparticles suitable, for example, for use as a raw material for cosmetic products or products used in any other sector and in which clay nanoparticles obtained by means of chemical synthesis or the "bottom-up" method are used. The method of the invention includes the steps of selecting the clays to be treated, pre-grinding the selected clays to reduce the particle size to between 5 and 15 micrometres, and subsequently grinding same to reduce the particle size to nanometric dimensions of less than one micrometre. The invention also relates to a cosmetic product or product used in any other sector, which comprises between 15 and 45% clay nanoparticles obtained using the "top-down" method.

Description

PROCEDURE FOR OBTAINING NANO-PARTICLES OF CLAYS AND PRODUCT PRODUCED WITH SUCH NANO-PARTICLES

OF CLAYS

TECHNICAL FIELD OF THE INVENTION

The present invention relates to the process for obtaining nano-particles of clays, the latter, suitable for use, for example, as raw material for cosmetic products or products of any other sector in which nano-particles have been used of clays obtained by chemical synthesis or "Bottom-up" method.

BACKGROUND OF THE INVENTION

As is known, clays are extracted from natural deposits and are particularly rich in minerals, constituting a natural sediment in high demand today for multiple applications.

Due to the natural wear of the rocks, the clays formed over the years as a sediment rich in minerals and organic components, such as, Calcium, Sodium, Potassium, Magnesium, Iron, Silicon, Manganese, Vitamin A, Vitamin E, B-Carotene, among others.

For this reason, clays have always been used, both for cosmetic and medical uses. In geotherapy, clays are used as natural therapy. Among its many benefits and properties they contain, they are cleansing, detoxifying and antiseptic because, if used internally, they absorb toxic substances. A) Yes They are regenerating and healing due to one of its components, silica. Due to their high content in trace elements they are also very remineralizing. There are many properties of clays depending on the type used. Among the most used are green clay, clay bank and red clay.

In the cosmetic sector, clays are mostly used in skin treatments. In the formulation of multiple products, from face masks, body creams and shower gels to shampoos and toothpastes.

As seen, clays contain minerals with a known positive influence on fluid balance and skin cell structure. In the latter, the particular composition of the clays causes a remineralizing and slimming effect. Additionally, the clays have a calming effect on irritated skin, balance redness due to their mineral composition and leave an exceptionally pleasant and positive skin sensation.

Clays intended for cosmetic applications are selected by evaluating the following requirements:

-pH: 6.5 - 9.0 (10% suspension),

-color: soft.

- mineral composition.

Like the selection of clays, their particle size is an important detail to consider in order to enhance the properties of said clays in cosmetic products. The smaller the particle size of clays, the greater the penetration of same in the layers or areas of the skin that require treatment. In other words, the treatment of the cosmetic product that comprises them will be more effective. Among the factors that determine dermal penetration are: the nature, physical condition and structure of the products; the type of vehicle in which said products are suspended or dissolved; as well as, hydration and skin condition.

Of these factors, only two of them can carry out actions to improve the dermal penetration of the cosmetic product: a) Nature, physical state and structure of the clays.

Clays in their natural state have a size that, by decision, is less than 0.002 mm. This size can be considered as a large particle, which hinders its penetration through the skin's dermal barriers. b) Type of vehicle in which the clays are suspended.

The vehicle or compound used to facilitate the application of the product can modify its penetration capacity. The suspension and concentration of clay in the vehicle will condition its permeability. Currently, the clays are applied to the skin suspended in water, that is, using a hydrophilic vehicle; However, recent studies show that the use of a lipophilic vehicle can penetrate the product into the dermal layers of the skin 200 times faster than with water.

Therefore, the need arises to bring the particle size of the clays to be used in cosmetic products to a minimum expression, that is, to sub-micronic levels, with a view to increasing the penetration capacity of said products in the dermal layers of the skin.

Processes for obtaining sub-micronic clays based on their chemical synthesis are known. However, these known processes are not suitable for the cosmetics sector because they fail to reproduce the intrinsic characteristics of clays, in addition to being very expensive both economically and from the point of view of the process.

These known processes are based on "Bottom-up" or bottom-up techniques, being a chemical ascending method that refers to the construction of structures atom by atom or molecule by molecule. Said "Bottom-up" method comprises the following parts: a) Chemical synthesis: technique in which raw materials such as molecules or particles are produced, which can be used directly as a product or to manufacture more advanced or complex materials. b) Self-assembly: a technique in which atoms or molecules sort themselves into nanostructures through physical and / or chemical interactions between the basic units. Self-assembly has always occurred in nature, as it is the basis of the formation of every living organism, salt crystals, and snowflakes. c) Positional assembly: atoms, molecules or their aggregates are deliberately manipulated and positioned one by one.

As can be seen, these known methods make it impossible to obtain clay nano-particles in a simple and economical way. Likewise, since they are chemical methods, with their application, the properties of the clays included in their natural state are impaired.

For this reason, it is necessary to design a procedure for obtaining technically viable and economical clay nano-particles, whose clays are suitable for use as raw material in cosmetic products that provide an effective treatment. On the part of the applicant, it is unknown the existence of a procedure for obtaining nanoparticles of clays that show similar characteristics to those presented by the invention that is recommended herein.

DESCRIPTION OF THE INVENTION

The present invention is established and characterized in the independent claims, while the dependent claims describe other features thereof.

The object of the invention is a method of obtaining nano-particles from clays, the latter, suitable for use, for example, as raw material in cosmetic products, or in other products of any other sector in which clay nanoparticles obtained by chemical synthesis or "Bottom-up" method have been used. The technical problem to be solved is the reduction of the particle size of said clays to submicron or nano-metric levels, without affecting the intrinsic characteristics thereof.

The procedure for obtaining the clay nanoparticle to be patented is based on the "Top-down" or top-down technique, and comprises the following steps: a) select the clays to be treated,

b) pre-grind the selected clays, in step a) until their particle size is reduced between 5 mm and 15 microns,

c) grind the pre-milled clays in step b) until their particle size is reduced to nano-metric dimensions below a mere.

Thus, by applying the proposed procedure, it is possible to obtain nano-particles of clays, where, the reduction of the particle size of said clays has been carried out using a physical descending method, which, does not harm the properties, for example, regenerating and healing of clays, typical of their natural state.

Additionally, the present invention relates to a product based on clay nano-particles, for example, a cosmetic product, such as a body cream or a face mask, comprising between 15% and 45% nano-particles. of clays with particle size below one mill, obtained according to the "Top-down" procedure, or top-down, subject to The present invention.

STATEMENT OF THE INVENTION OF THE INVENTION In view of the foregoing, the present invention relates to a method of obtaining nano-particles of clays, useful for use as raw material, for example, cosmetic products or products of any other sector in which nano-particles of clays obtained by chemical synthesis or "Bottom-up" method have been used.

The procedure begins with the selection of the most suitable clays to be treated. Preferably, the clays will be selected based on a mineralogical and chemical analysis.

Likewise, it is preferred that the selected clays constitute 100% of the composition to be treated, so that the cleanest veins are chosen and then complete and exhaustive analyzes are carried out comparing the minerals that compose them and choosing the most suitable ones. The selected clays may or may not be washed at the site itself.

In the event that the clays have not been washed in the reservoir, they will be mixed with water until the mixture takes the form of a slip, that is, a mixture of muddy or almost liquid consistency in order to remove impurities. The impurity-free mixture will remain stable over time by means of a stirrer to prevent sedimentation, and even preservatives could be added to the mixture in order to avoid problems by contamination at the microbiological level.

Subsequently, the selected clays, included in the impurity-free mixture described above, are pre-milled until their particle size is reduced between 5 mm and 15 microns.

Preferably this wet pre-milling of the clays is carried out in a ball mill, using the water itself added prior to the selected clay not washed in the reservoir.

Once the particle size of the clays has been reduced between 5 mm and 15 microns, they are dried.

Preferably, the drying is carried out in a drying chamber using a hot inert gas at low pressure thus creating a disintegration and circulation effect that allows rapid drying with a minimum heating of the solid material, that is, the clay. Thus, the water evaporates, ensuring the particle size obtained in the mill, that is, between 5 mm and 15 microns.

On the other hand, in the case that the selected clay has been washed in the deposit itself, it is directly pre-ground until its particle size is reduced between 5 mm and 15 microns.

Preferably, this dry or wet pre-milling of the clays is carried out in a ball mill, using alumina balls. The grinding time will depend on the initial particle size and the hardness of the material. Next, the pre-ground clays previously ground again, this time, until their particle size is reduced to nano-metric dimensions below one mill.

This new grinding of the clays will be carried out in an aqueous medium, so that they can be introduced in the subsequent formulations of products based on nano-particles of clays in which, for example, cosmetic formulations or other product formulations of any another sector in which nano-particles of clays obtained by chemical synthesis or "Bottom-up" system have also been used.

For this, it is preferred that said milling be performed in an attrition mill. In this process of mechanical attrition, the pre-milled clays, with particle size between 5 mm and 15 microns, are introduced into the mill's milling chamber together with the aqueous milling medium and balls, the latter, preferably, of zirconium oxide with a size between 0.3 and 0.4 mm; where, they are agitated strongly product of the high speed of rotation, between 25 and 50 Hz (1500 and 3000 rpm), of the attrition mill, causing the impact of the zirconium oxide balls with the clays, until reducing their particle size below a miera. Once the clay suspension with the required granulometry is obtained, that is, with nano-particles with a size below a mill, this can be used in the formulation of products based on clay nano-particles, for example, cosmetic products or products from other sectors in which it has been used Clay nano-particle obtained by chemical synthesis or "Bottom-up" system.

Thus, a product based on clay nano-particles, according to the present invention, for example, a cosmetic product, comprises between 15% and 45% of clay nano-particles with particle size below a mere, obtained according to the procedure described above.

For example, a first embodiment of the cosmetic product could be a body cream that comprises:

- 5% -15% protect NMF (sodium lauryl glyceryl stearate, sodium glutamate, stearoillactilate),

0.5% -9.5% cetearyl alcohol,

0.5% -9.5% coffee butter,

- 1% -10% of T oil OE (ethercapylyl),

1% -10% of T oil GTCC (caprylic / capricotriglycerides),

- 2% -12% sweet almond

- 2% -12% olive oil,

- 5% -30% of clay nanoparticles,

- up to 100% water,

- 3% -12% glycerin,

0.5% -9.5% Protelan PCA (Sodium PCA),

- 0.1% -2% tocopherol acetate,

- 0.1% -2% preservative, and

0.1% -3% perfume

A second embodiment of the cosmetic product, according to the present invention, could be a facial mask comprising: - 2% -9% protect NMF (sodium lauryl glyceryl stearate, sodium glutamate, stearoillactilate),

- 1.5% -5% titanium dioxide,

0.2% -5% allantoin,

- 2% -9% arnica,

- 2% -9% calendula extract,

- 5% -30% of clay nanoparticles,

- up to 100% water,

- 2.5% -9% glycerin,

- 0.1% -5% preservative, and

0.1% -3% perfume

Claims

RE IVINDICATIONS

1.-Procedure for obtaining nano-particles of clays, which includes the following stages:

a) select the clays to be treated,

2. -Procedure according to claim 1, wherein the selection of the clays in step a) is based on a mineral and chemical analysis of the clays that make up the veins of the reservoir from which they are extracted.

3. - Procedure according to claim 1 or 2, wherein the clays selected in step a) constitute 100% of the composition to be treated.

4. -Procedure according to claim 1, wherein step b) is carried out in a ball mill, the pre-milling being carried out dry.

5. -Procedure according to claim 1, wherein step b) is carried out in a ball mill, the pre-milling being carried out by wet way, using water as the grinding medium.

6. -Procedure according to claim 5, wherein between the pre-milling of stage b) and the milling of stage c) the drying of the pre-ground clays in stage b) is carried out.

7. -Procedure according to claim 6, wherein the drying is carried out in a drying chamber, using a low pressure hot inert gas as a drying medium.

8. -Procedure according to claim 1, wherein step c) is performed in an attrition mill, using an aqueous grinding medium.

9. -Procedure according to claim 8, wherein the zirconium oxide balls with a size between 0.3 and 0.4 mm are used in the attrition mill.

10. - Product based on nano-particles of clays, characterized in that it comprises between 15% and 45% of nano-particles of clays, obtained according to the method of any of the preceding claims, with particle size below a miera.

11. Product according to claim 10, characterized in that it is a cosmetic product.

12. Product according to claim 11, characterized in that it is a body cream.

13. Product according to claim 12, characterized in that it comprises:

- 0.5% -9.5% cetearyl alcohol,

- 0.5% -9.5% coffee muffin,

- 1% -10% of T oil OE (ethercapylyl), - 1% -10% of T oil GTCC (caprylic / capricotriglycerides),

- 2% -12% sweet almond

- 2% -12% olive oil,

- 5% -30% of clay nanoparticles,

- up to 100% water,

- 3% -12% glycerin,

- 0.5% -9.5% Protelan PCA (Sodium PCA),

- 0.1% -2% tocopherol acetate,

- 0.1% -2% preservative, and

- 0.1% -3% perfume.

14. Product according to claim 11, characterized in that it is a facial mask.

15. Product according to claim 14, characterized in that it comprises:

- 2% -9% protect NMF (sodium lauryl glyceryl stearate, sodium glutamate, stearoillactilate),

- 1.5% -5% titanium dioxide,

- 0.2% -5% allantoin,

- 2% -9% arnica,

- 2% -9% calendula extract,

- 5% -30% of clay nanoparticles,

- up to 100% water,

- 2.5% -9% glycerin,

- 0.1% -5% preservative, and

- 0.1% -3% perfume.