WO2024144585A1

WO2024144585A1 - Modified halloysite with fruit extract additives

Info

Publication number: WO2024144585A1
Application number: PCT/TR2023/051298
Authority: WO
Inventors: Tuğba UÇAR DEMİR
Original assignee: Esan Eczacibasi Enduestriyel Hammaddeler Sanayi Ve Ticaret AS
Current assignee: Esan Eczacibasi Enduestriyel Hammaddeler Sanayi Ve Ticaret AS
Priority date: 2022-12-27
Filing date: 2023-11-09
Publication date: 2024-07-04
Anticipated expiration: 2025-06-27

Abstract

The invention relates to a modified halloysite with fruit extract additives, which is obtained by adding various fruit extracts in the nano-scale tubular structure of the halloysite mineral (Al₂SiO₅(OH)₄) comprising the naturally formed nanotubes and which enables a prolonged use and action to be achieved owing to the controlled release of the fruit extracts. According to the invention, the fruit extracts added in the halloysite mineral via different methods are bonded between the halloysite clay layers and the controlled release of the fruit extracts are enabled over time under the influence of the heat. Compared to the extent and time of volatilization of the fruit extracts under the normal conditions, the halloysites with fruit extract additives according to the invention enable the fruit extracts to be released at a rate that is about 200 times slower.

Description

MODIFIED HALLOYSITE WITH FRUIT EXTRACT ADDITIVES

Subject of the Invention

The invention relates to a modified halloysite with fruit extract additives, which is obtained by adding various fruit extracts in the nano-scale tubular structure of the halloysite mineral (A SiOstOH^) comprising the naturally formed nanotubes and which enables a prolonged use and action to be achieved owing to the controlled release of the fruit extracts.

State of the Art

The halloysite is a mineral belonging to the kaolin group and exists in the form of nanotubes during its formation in the nature. In this mineral having a folded structure as in the minerals of the clay group, the layers, unlike those of the other minerals, bend into a nanotube form due to their surface loads and stabilities. However, not every halloysite in the nature has the same shape; they have different properties because of their content of impurity, the presence of the wall rocks, the form of the developed tubes and the water content. In physical terms, the halloysite minerals, which exhibit differences according to the conditions present during the geological formation in different reserves, generally have a unidimensional length of about 2 microns, an outer diameter of about 50-60 nm and an inner diameter of about 15-30 nm. In the interior structure of the halloysite mineral, the interlaminar spacing value (the value of d) is on the sub-nano level, i.e., in the range of 7-10 A.

According to the state of the art, the halloysite is used in the porcelain industry where it is processed in crude form. The studies on the halloysite and the products obtained from the manufacture find use commonly in the ceramic industry. Generally, the halloysite is used in the porcelain production for obtaining transparency, owing to the advantage provided by its nanotubular structure. The halloysite does not yet have an effective use in the fields other than the ceramic industry, e.g. in the cosmetic industry. The halloysite is a naturally developed nanotubular clay mineral with significant potential of use in various industrial fields. The halloysite nanotubes are cheaper than the other nano-fillers such as carbon nanotubes and are also biocompatible. The halloysites with nano-structure have excellent mechanical properties and good biocompatibility. Their features of environment-friendliness, biocompatibility and natural abundance make the halloysites an important nano-material in the biomedical, pharmaceutical and cosmetic fields. The naturally formed tubular halloysite clay, owing to its versatile properties, attracts the interest of many researches from different fields. The studies on the use of the halloysites especially in the fields such as cosmetics have started to become popular in the recent years; however, due to its potential for use, there is a need for improving the use of the halloysite mineral particularly as a carrier and controlled release agent.

The fruit extracts and flavors are among the frequently used ingredients in the fields of cosmetics and pharmaceutics. According to the state of the art, the fruit extracts are available in powder or liquid form. Although various flavors, oils and water-based oils may be used in the formulas intended for personal care applications, some of these aromatic oils are not of natural origin. As for the natural ingredients, since a part of these is not loaded in a carrier structure within the formulation, the fragrance and release effects wear off more quickly and it is only possible to obtain the products with more limited shelf life.

The fruit extracts having aromatic substance having low or high fold require a carrier base material for the uses that are based on individual application. However, the solutions, which rapidly lose their effect in case the extracts are used along with the volatile oil ingredients, are available as the base material in the practices according to the state of the art. Accordingly, there exists a need for carrying out improvements in the use of the halloysite nanotubes as a carrier and controlled release agent, for the purpose of developing the biocompatible options, which feature slow release to enable the prolonged and effective use of the fruit extracts and flavors, and also for the purpose of actualizing the potential of and starting the effective use of the halloysite mineral particularly in the field of cosmetics. Object of the Invention

An object of the invention is to develop the modified halloysites, which enable a prolonged use and action to be achieved as a result of the controlled release of the fruit extracts. According to the invention, the halloysite mineral is used as a carrier and controlled release agent to enable effective use of the fruit extracts and flavors in the cosmetics, in the personal use chemicals and in the polymers where the odor and controlled release are important.

According to the invention, in order to provide controlled release over a prolonged time, the process involves the use of the fruit extracts bonded within the nanotubular structure of the halloysites, the halloysites are optimized, and the halloysites with fruit extract additives are rendered useful in the fields of application such as cosmetics and polymers.

According to the invention, the fruit extracts added in the halloysite mineral via different methods are bonded between the halloysite clay layers and the controlled release of the fruit extracts are enabled over time under the influence of the heat. In this way, the prolonged and effective use of the fruit extracts and flavors in a biocompatible manner is achieved particularly in the field of cosmetics. Compared to the extent and time of volatilization of the fruit extracts under the normal conditions, the halloysites with fruit extract additives according to the invention enable the fruit extracts to be released at a rate that is about 200 times slower.

Detailed Description of the Invention

Described in the invention is a modified halloysite with fruit extract additives, which is obtained by adding various fruit extracts in the nano-scale tubular structure of the halloysite mineral (A SiOsjOH^) comprising the naturally formed nanotubes and which enables a prolonged use and action to be achieved owing to the controlled release of the fruit extracts.

Owing to the tubular structure of the halloysite mineral, it is possible to bind various agents between the clay layers. Owing to the clay nanotubes in the invention, more effective use of the fruit extracts is enabled as a result of adding the fruit extracts in the carrier structure and achieving the controlled release specific to the field of application. The halloysite mineral, which has a nano-scale layer structure, a wide surface area and a structure enwrapped just like a paper towel and in which it is possible to bind agents between the layers, on the surface and in the internal space, provides an ideal medium for the binding of the fruit extracts and flavors. Owing to this morphological structure, the release of the aromatic oils in the fruit extracts is enabled to take place over a longer period of time under the influence of the factors such as heat and contact time and a structure that does not evaporate in a short time is obtained.

As a result of the analyses on the controlled release, it was found that the halloysites with fruit extract additives according to the invention enable the fruit extracts to be released at a rate that is about 200 times slower when compared to the extent and time of volatilization of the fruit extracts under the normal conditions.

In the modified halloysite according to the invention comprising the fruit extracts within the nanotubular structure thereof, all of the aromatic substances, which are provided to achieve the exact sense of natural taste in the natural extracts used, are obtained from the fruits or plants (FTNF/S*). The extracts processed directly in-situ in the agricultural fields in various geographies were used for the invention.

In a preferred embodiment of the invention, at least one extract selected from the group comprising lemon, apple and pomegranate is used as the fruit extract comprised in the halloysite. Said fruit extracts may be oily or water-soluble and in liquid and/or powder form.

The clay mineral used in the modified halloysite according to the invention comprising the fruit extracts within the nanotube structure thereof is in the form of naturally formed halloysite nanotubes with a 10A and 7A band structure and has the formula Al2SiO₅(OH)4.4.H₂O.

The tubes of the halloysite used according to the invention have a length of 1-1.5 micron, an inner diameter lumen space of 15-30 nm and an outer diameter width of 50-60 nm.

In an embodiment of the invention, the halloysite comprises the fruit extracts at a ratio of in the range of 5-30% by weight. In another embodiment of the invention, the halloysite comprises 5% or 10% or 20% or 30% by weight fruit extracts. In the preferred embodiment of the invention, the halloysite comprises 20-30% by weight fruit extracts.

The method for obtaining the modified halloysite according to the invention comprising the fruit extracts within the nanotube structure thereof comprises in general terms the process steps of i. preparing the fruit extracts, ii. mixing the fruit extracts with the halloysite, and iii. drying the mixed fruit extracts and halloysite.

Preparing the fruit extracts and mixing the prepared fruit extracts with the halloysite in the modified halloysites according to the invention comprising the fruit extracts within the nanotube structure thereof comprises the process steps of

• directly mixing the extracts (i.e. pomegranate/apple/lemon extract with low/high fold) with the halloysite, or

• preparing the extracts by dispersing the same in ethanol according to an ethanokwater ratio in the range of 1:0.5 - 1:1 and subsequently mixing the prepared extracts with the halloysite.

The ratio of dilution in water is in the range of 10-50% for the extracts used according to the invention.

Within the scope of the invention, the process of mixing the extracts and the halloysite is performed in two different ways. Said mixing process comprises the process step of

• mixing the halloysite mineral in powder form (dry form-moisture content of less than 1%) with said extracts, or

• dispersing the halloysite mineral in water according to different solid matter concentrations and then mixing the same with said extracts.

The halloysite and the fruit extracts are mixed for 30 minutes at room temperature and subsequently for 60 minutes at 70°C. The drying is then performed in a fan drying oven at 65°C, and finally, the obtained halloysites with fruit extract additives are subjected to the contact angle analysis, the color analysis, the chemical analysis and the mineralogical analysis.

According to the obtained results, there is no problem of uniformity encountered during the mixing. After the addition of the fruit extracts, the viscosity value was observed to drop, but the filtration time value did not show variability in the extracts dispersed in alcohol. Therefore, the fruit extract dispersed in alcohol feature the ability of being used in the method for obtaining the halloysite with fruit extract additives according to the invention.

As a result of the evaluations, the surface area values of the halloysite with fruit extract additives dropped from the initial value of 70 m²/g to the values in the range of 30-35 m²/g. This decrease shows that the fruit extracts successfully entered between the nanotubes.

For the pomegranate and apple extracts used in the trials conducted within the scope of the invention, the samples with an initial lightness-darkness value (L) in the range of 89- 90 became darker in color, the L value dropped, and the values of redness increased. After performing the washing, some of the extracts in the samples was observed to be released. This indicates the presence of the excess residual extracts unable to be bonded into the halloysite after the washing. This situation results from the addition of an excessive quantity of fruit extracts, the failure to achieve the suitable temperature and other conditions or the inability of the fruit extracts to enter between the clay layers due to the molecular weight. This in turn leads to a darkening as indicated by the color values and an excess residual extract quantity on the surface. Therefore, it is very important to ensure that the fruit extracts are present at a ratio of 5-30% by weight in the halloysite according to the invention and that the halloysite is obtained via the method according to the invention under the specified ambient conditions.

According to the invention, although it was deemed appropriate to mix two powders, i.e., the halloysite and the fruit extracts, by dispersing in alcohol or water the extracts that are preferably in powder form, the extracts, which were of low and high fold and which were dispersed at a ratio of 10-50% in water, were used taking the risks into consideration. Since the halloysite according to the invention enables a prolonged use and action to be achieved owing to the controlled release of the fruit extracts, it is preferably used in the cosmetic products and is applied topically.

Claims

1. A modified halloysite characterized in that the modified halloysite comprises the fruit extracts inside the nanotubular structure thereof.

2. A modified halloysite according to Claim 1 characterized in that the modified halloysite comprises 5-30% by weight fruit extracts.

3. A modified halloysite according to Claim 1 or 2 characterized in that the modified halloysite comprises 20-30% by weight fruit extracts.

4. A modified halloysite according to any one of the preceding claims characterized in that the modified halloysite comprises 5% or 10% or 20% or 30% by weight fruit extracts.

5. A modified halloysite according to any one of the preceding claims characterized in that as said fruit extract, at least one fruit extract is selected from the group comprising lemon, apple and pomegranate.

6. A modified halloysite according to any one of the preceding claims characterized in that said fruit extract has an oily or water-soluble structure.

7. A modified halloysite according to any one of the preceding claims characterized in that said fruit extract is in liquid and/or powder form.

8. A modified halloysite according to any one of the preceding claims characterized in that said fruit extract is a fruit extract, which is prepared in such a way that the ethanokwater ratio will be in the range of 1:0.5 - 1:1.

9. A modified halloysite according to any one of the preceding claims characterized in that said halloysite is in powder form or in a form dispersed in water.

10. A modified halloysite according to any one of the preceding claims characterized in that the halloysite have a tube length of 1-1.5 micron.

11. A modified halloysite according to any one of the preceding claims characterized in that the halloysite has an inner diameter lumen space of 15-30 nm.

12. A modified halloysite according to any one of the preceding claims characterized in that the halloysite has an outer diameter width of 50-60 nm.

13. A modified halloysite according to any one of the preceding claims characterized in that the halloysite has a 10A and 7 A band structure.

14. A modified halloysite according to any one of the preceding claims characterized in that the halloysite has the formula Al2SiOs(OH)4.4.H2O.

15. A modified halloysite according to any one of the preceding claims characterized in that the halloysite has a surface area of at least 30-35 m²/g.

16. A modified halloysite according to any one of Claims 1-15 characterized in that the modified halloysite is suitable for use in the cosmetic products.

17. A modified halloysite according to any one of Claims 1-15 characterized in that the modified halloysite is suitable for topical application.

18. A cosmetic product comprising a modified halloysite according to any one of Claims 1-15.

19. A method for obtaining a modified halloysite comprising the fruit extracts within the nanotube structure thereof characterized in that the method comprises the process steps of i. preparing the fruit extracts, ii. mixing the fruit extracts with the halloysite, and iii. drying the mixed fruit extracts and halloysite.

20. A method according to Claim 19 characterized in that the extracts are prepared in the process step of preparing the fruit extracts in such a way that the ethanokwater ratio will be in the range of 1:0.5 - 1:1.

21. A method according to Claim 19 characterized in that in the process step of mixing the fruit extracts with the halloysite, the extracts are directly mixed with the halloysite or are mixed with the halloysite by way of being dispersed in ethanol and water.

22. A method according to Claim 19 or 21 characterized in that in the process step of mixing the fruit extracts with the halloysite, the halloysite mineral is in powder form or in a form dispersed in water.

23. A method according to any one of Claim 19, 21 or 22 characterized in that in the process step of mixing the fruit extracts with the halloysite, the halloysite and the fruit extracts are mixed for 30 minutes at room temperature and subsequently for 60 minutes at 70°C.

24. A method according to Claim 19 characterized in that in the process step of drying the mixed fruit extracts and halloysite, the drying is performed at 65°C.

25. A modified halloysite comprising the fruit extracts within the nanotube structure thereof, said modified halloysite being obtained by a method according to any one of Claims 19-24.