KR20100127000A - A nanohybrid of a phenolic acid uv-screening agent with a layered metal hydroxide, a process for the preparation thereof, and a composition for uv screening comprising the same - Google Patents

Abstract

PURPOSE: A nanohybrid of a phenolic acid UV absorbent and a layered metal hydroxide, a producing method thereof, and an anti-ultraviolet ray composition containing thereof are provided to improve the stability of the phenolic acid UV absorbent. CONSTITUTION: A nanohybrid contains a phenolic acid UV absorbent inserted among layers of a layered metal hydroxide. The layered metal hydroxide is marked with either chemical formula 1: [M(II)1-xM(III)x(OH)2]X+(An-)X/n·yH2O, or chemical formula 2: [M(II)(OH)x'](An-)(2-x')/n·yH2O. In the chemical formulas, M(II) is a divalent metal positive ion, and M(III) is a trivalent positive ion. A producing method of the nanohybrid comprises a step of forming a phenolic acid UV absorbent and divalent metal positive ion solution, and a step of titrating the solution to obtain precipitates.

Description

Nano-hybrid of a phenolic acid UV-screening agent with a layered metal hydroxide, a process for the preparation according, and a composition for UV screening comprises the same}

The present invention relates to a hybrid of a phenolic ultraviolet absorber with a layered metal hydroxide. More specifically, the phenolic ultraviolet absorbent can block direct skin contact with the phenolic ultraviolet absorbent and can increase the stability of the phenolic ultraviolet absorbent. The present invention relates to a hybrid of a phenolic ultraviolet absorbent with a layered metal hydroxide, a method for producing the same, and a sunscreen cosmetic comprising the same.

In general, ultraviolet rays reaching the earth from the sun are electromagnetic waves having a wavelength of 200 nm to 400 nm, and when exposed to humans, it is known that chemical bonds of cells including DNA, enzymes, proteins, etc. may be destroyed (Burren 1998; Kielbassa). 1997; Kvam 1997; Wenczl 1998; Young 1998). Ultraviolet rays are divided into three areas according to the wavelength: long-wave UV-A (320-400nm), medium-wave UV-B (280-320nm) and short-wave UV-C (200-280nm). When investigated, it is reported to cause various skin diseases. UV-C is known to disappear while passing through the ozone layer and reaches the surface of the skin. UV-B penetrates to the epidermis of the skin and causes skin burns such as inflammation, freckles, edema, and erythema. UV-A penetrates the dermis of the skin to promote skin cancer and melanin formation, and is known to promote skin aging due to degeneration of proteins in the dermal layer, capillary expansion, and destruction of nucleic acids (DNA).

Currently, sunscreens are widely used organic UV absorbers and inorganic UV scatterers. The organic ultraviolet absorber is an organic acid compound having a structurally conjugated double bond and a phenol structure, and is widely used because of its high effect even in a small amount. As such organic ultraviolet absorbers, phenolic acid derivatives such as caffeic acid, coumaric acid, and ferulic acid are known. These phenolic ultraviolet absorbents are very unstable in air and are easily destroyed by oxygen and UV irradiation, and their toxicity and product toxicity due to photoreactions prevent their effectiveness and safety when used on the skin. There is this. In addition, the organic UV absorber has different blocking effects depending on the type, and when used together, the blocking range and effect can be increased, but as the type and amount thereof increase, the UV absorber is absorbed into the skin itself. Since it is accompanied by skin irritation due to toxicity, the amount of use is limited. Therefore, most countries strictly limit the content range and compounding limit of the organic UV absorber. In addition, when the organic UV absorber is dissolved in a solvent such as the number of formulations that occupy most of the cosmetic formulation, the UV blocking region may be different from the powder state or the range of the region may be reduced. However, in contrast to the inorganic UV scattering agent is heavy in feeling and appearing cloudy when applied to the skin, the organic UV absorber is preferable in terms of not feeling heavy and no clouding phenomenon.

Inorganic UV scattering agents include metal oxides such as titanium dioxide, zinc oxide, or cerium oxide. Titanium dioxide and zinc oxide have less skin whitening and absorb ultraviolet rays of long and medium wavelengths, and thus are receiving more attention. Much research has been done to develop formulations containing such inorganic ultraviolet scatterers (WO 93/11742, EP 0 559 319, US 5,250,289). However, it is not satisfactory in formulation stability, turbidity, feeling when applied to the skin, and still lacks in effective sun protection.

In order to solve the above problems, studies have been conducted on appropriately formulated sunscreens, each of which is an organic UV absorber and an inorganic UV scattering agent. Problems such as feeling of use when not completely solved.

Therefore, there is a need for the development of a sunscreen that can have a good feeling, no haze and very low toxicity to the skin, and can be stably maintained as a sunscreen.

Accordingly, the present inventors have studied organic UV absorbers, which are not heavy in use and have no clouding phenomenon, to improve their safety and effectiveness, and thus develop effective sunscreens. As a result, they have hybridized organic UV absorbers to layered metal hydroxides as nano-hybrids. When manufacturing, it was found that the organic UV absorber may not directly contact the skin, thereby significantly reducing the toxicity to the skin and increasing the stability of the organic UV absorber itself. Accordingly, it is an object of the present invention to provide a hybrid comprising an organic ultraviolet absorber which is safe and does not cause toxicity to the skin and is effective in blocking ultraviolet rays A and B.

Another object of the present invention to provide a method for producing a hybrid comprising the organic ultraviolet absorber.

Still another object of the present invention is to provide a composition for sunscreen containing a hybrid comprising the organic ultraviolet absorber.

In order to achieve the above object, the present invention

Phenolic acid ultraviolet absorbers are introduced between the layers of layered metal hydroxides to provide hybridized, nanocomposites of phenolic acid ultraviolet absorbers and layered metal hydroxides.

In another aspect of the present invention,

Preparing a solution of phenolic acid ultraviolet absorber and divalent metal salt; And

It provides a method for producing a nano hybrid according to the present invention, comprising the step of adding a base to the solution to titrate the pH to 4 to 10 to obtain a precipitate.

In addition, the nano-composite according to the present invention is

Preparing a solution of a divalent metal salt;

Adding a base to the solution of the divalent metal salt to titrate the pH to 4 to 10 to form a precipitate; And

The phenolic acid ultraviolet absorber solution may be added to the formed precipitate, and the phenolic acid ultraviolet absorber may be introduced into the layer of the precipitate by ion exchange with anions present between the layers of the precipitate.

In addition to the above method, the nano hybrids according to the present invention

Preparing a solution of a divalent metal salt;

Adding a base to the solution of the divalent metal salt to titrate the pH to 4 to 10 to form a precipitate;

Calcining the formed precipitate by heat treatment at 250 to 450 ° C. for 2 to 8 hours; And

It can be prepared by a method comprising adding to the calcined precipitate in a phenolic acid ultraviolet absorbent solution and stirring to reconstruction.

 In still another aspect, the present invention provides a composition for protecting against ultraviolet rays, comprising nanocomposites of the phenolic acid ultraviolet absorbent and the layered metal hydroxide according to the present invention.

Hereinafter, the present invention will be described in more detail.

The nanocomposite of the phenolic ultraviolet absorber provided by the present invention with the layered metal hydroxide is obtained by introducing and hybridizing the phenolic ultraviolet absorber into the layers of the layered metal hydroxide. Phenolic acid ultraviolet absorbents are hybridized with layered metal hydroxides to form nano-hybrids, thereby improving the stability of the phenolic ultraviolet absorbents in the air and the stability to ultraviolet rays, thereby improving the UV blocking effect and when applied to the skin. The phenolic ultraviolet absorbents do not come in direct contact with the skin, which can significantly reduce the toxicity to the skin. In addition, by modifying the surface of the hybrid material to a predetermined material can improve the dispersibility in the solvent to be applied, it can be easier to formulate as a skin external preparation.

The layered metal hydroxide constituting the nanocomposite is a weakly basic or neutral inorganic compound and has excellent biocompatibility without side effects such as biotoxicity or skin irritation. As the layered metal hydroxide, a compound represented by the following general formula (1) or (2) may be used.

[M (II) _1-x M (III) _x (OH) ₂ ] ^{X +} (A ^n- ) _{X /} nyH ₂ O

In Chemical Formula 1,

M (II) represents a divalent metal cation;

M (III) represents a trivalent metal cation;

A is an anionic material, n is the number of charges of the anion;

x is a number from 0.01 to 0.5;

y is a positive number greater than zero.

[M (II) (OH) _{x '} ] (A ^n- ) _{(2-x') / n} yH ₂ O

In Chemical Formula 2,

M (II) represents a divalent metal cation;

A is an anionic material, n is the number of charges of the anion;

x 'is a number greater than 1 and less than 2;

y is a positive number greater than zero.

Examples of the divalent metal cation include Mg ²⁺ , Ca ²⁺ , Co ²⁺ , Cu ²⁺ , Ni ²⁺ , or Zn ²⁺ , and the trivalent metal cations include Al ³⁺ , Cr ³⁺ , Fe ³⁺ , Ga ³⁺ , In ³⁺ , V ³⁺ , or Ti ³⁺ . The anions include NO ₃ ⁻ , Cl ⁻ , OH ⁻ , or CO ₃ ^2- . The divalent metal cation, the trivalent metal cation, and the anion are not limited to the above types, and may include all of those known as layered metal hydroxides in the art. In particular, the layered metal hydroxide of Formula 1 is called a metal double layer hydroxide (Layered Double Hydroxide, LDH), the compound of Formula 2 is called a metal basic salt (Metal Basic Salt). Among the metal basic salts, zinc basic salts (ZBS) represented by the following general formula (3) are particularly preferable.

Zn ₅ (OH) ₈ (A ^n- ) ^{2 / n} nH ₂ O or Zn ₃ (OH) ₄ A ₂ nH ₂ O

In Formula 3, A and n are as defined in Formula 2.

The layered metal hydroxide has a layered crystal structure and exhibits unique interlayer reactivity as well as anion exchange capacity. This is because the layered metal hydroxide has a different cause, but because the hydroxide layer has a positive charge in common, an interlayer anion exists to compensate for this, and the interlayer anion may be replaced with another anionic species. Therefore, the nano hybrid material provided by the present invention is an anionized phenolic acid ultraviolet absorber and hybridized with the layered metal hydroxide.

In Formula 1, M (II) has a divalent metal ion corresponding thereto, and may include at least one or more divalent metal materials, and it is preferable that the divalent metal ion is 50 mol% or more with respect to the total metal ions.

In Formula 1, M (III) may optionally have a trivalent cation corresponding thereto, and may not be present at all as in Formula 2. When M (II) ions and M (III) ions coexist as shown in Formula 1, the excess M (III) ions may interfere with the formation of a layered structure, so that M (III) ions It is preferable to exist below 50 mol%.

A ^n- corresponding to an anion in the chemical formula corresponds to a position at which the phenolic acid ultraviolet absorber is substituted in the hybrid, and the phenolic acid ultraviolet absorber may be stabilized by being introduced into the interlayer of the layered metal hydroxide instead of an anion.

As the phenolic acid ultraviolet absorber constituting the nano-hybrid of the present invention, any ultraviolet absorber that has a phenolic acid structure and can be used as an organic ultraviolet absorber may be used, and typically, caffeic acid, kumaric acid and ferulic acid. , Or a combination thereof may be used. The phenolic acid ultraviolet absorber in the nano hybrid of the present invention may be contained in the range of 10 to 60 w / w% with respect to the entire nano hybrid.

The caffeic acid (Chemical Formula 4), Coumaric acid (Chemical Formula 5), and ferulic acid (Chemical Formula 6) each have a structure of Formulas 4 to 6, and are commercially available (Sigma-Aldrich Corp. et al.), And are known to those skilled in the art. It may also be produced by a method.

The nano hybrid according to the present invention may be obtained as particles having an average diameter of particles in the range of 200 nm to 50 μm, and preferably as particles in the range of 300 nm to 5 μm.

The layered metal hydroxide constituting the nanocomposite provided by the present invention has a strong hydrophilic property because of the presence of a hydroxyl group and a charge on the surface thereof. In this case, the hybrid according to the present invention, in which the phenolic ultraviolet absorber is introduced between the layers, shows a good dispersion degree in the aqueous dispersion medium. However, when an oily solvent is used as the dispersion medium such as cosmetics or ointment, the flocculation is poor. There may be problems such as appearing or phase separation.

Therefore, in order to control the dispersibility of the hybrid with the phenolic acid ultraviolet absorber and the layered metal hydroxide provided by the present invention, the surface of the hybrid can be modified with a predetermined material. Modification herein refers to substituting a phenolic acid ultraviolet absorber which may be present on the surface of the layered metal hydroxide hybrid with a hydrophobic or hydrophilic material or coating the surface of the nanocomposite itself of the layered metal hydroxide.

Modified materials can be appropriately selected depending on the characteristics of the dispersion medium to be dispersed. For example, to modify the surface of the hybrid to hydrophobicly, tocopherol, lauric acd, glyceryl monostearate (GMS), dimethicone, and ceto Stearyl alcohol (cetostearyl alcochol), cetyl alcohol (cetyl alcohol), lecithin (lecithin), or triglyceride (triglyceride) may be modified, such as, if you want to modify the hydrophilic tetraethyl orthosilicate (TEOS), carbomer ( carbomer, gum acacia, poloxamer, sodium lauryl sulfate, alginic acid, or polyoxyethylene castor oil.

In another aspect, the present invention provides a method for producing a nano hybrid of the phenolic acid ultraviolet absorber and the layered metal hydroxide according to the present invention. The preparation method includes a coprecipitation method of forming a nano hybrid by coprecipitation of a phenolic acid ultraviolet absorber together with the preparation of a layered metal hydroxide; An ion exchange method of forming a nano-composite by forming a layered metal hydroxide and then introducing a phenolic ultraviolet absorber into the layers of the layered metal hydroxide by ion exchange; And a reconstitution method of forming a nanocomposite by preparing a layered metal hydroxide, calcining and then reconstituting by adding a phenolic acid ultraviolet absorber solution.

Method for producing a nano hybrid according to the present invention by the co-precipitation method

Preparing a solution of phenolic acid ultraviolet absorber and divalent metal salt; And

Adding a base to the solution to titrate the pH to 4-10 to obtain a precipitate.

Method for producing a nano hybrid according to the present invention by the ion exchange method

Preparing a solution of a divalent metal salt;

Adding a base to the solution of the divalent metal salt to titrate the pH to 4 to 10 to form a precipitate; And

And adding a phenolic acid ultraviolet absorber solution to the formed precipitate to introduce a phenolic acid ultraviolet absorber between the layers of the precipitate by ion exchange with anions present between the layers of the precipitate.

Method for producing a nano hybrid according to the present invention by the reconstitution method

Preparing a solution of a divalent metal salt;

Adding a base to the solution of the divalent metal salt to titrate the pH to 4 to 10 to form a precipitate;

Calcining the formed precipitate by heat treatment at 250 to 450 ° C. for 2 to 8 hours; And

Adding to the calcined precipitate in a phenolic acid ultraviolet absorber solution and stirring to reconstruction.

The calcining step is for removing the anions present between the layers of the precipitate, preferably for about 4 hours at about 400 ℃.

When the layered metal hydroxide in the nanocomposite contains a trivalent metal salt, a trivalent metal salt is further added to a solution of a divalent metal salt or a solution of a phenolic acid ultraviolet absorber and a divalent metal salt to form a divalent metal salt and a trivalent metal salt. Or a solution of a phenolic acid ultraviolet absorber, a divalent metal salt, and a trivalent metal salt.

In the above production method, the divalent metal salt is Mg ²⁺ , Ca ²⁺ , Co ²⁺ , Cu ²⁺ , Ni ²⁺ , or Zn ²⁺ as a cation, and NO ₃ ⁻ , Cl ⁻ , OH ⁻ , O ^2- , SO ₄ ^2- , CO ₃ ^2- or a salt compound having succinate as an anion may be used, but is not limited thereto. In the case of the Zn metal salt, Zn (NO ₃ ), ZnSO ₄ , ZnO, ZnCl ₂ , Zn-succinate, or a hydrate thereof may be used, but Zn (NO ₃ ) may be preferably used. In the case of Ca metal salt, Ca (NO ₃ ) ₂ , CaSO ₄ , CaCO ₃ , CaCl ₂ , Ca (OH) ₂ , or a hydrate thereof may be used, but Ca (NO ₃ ) ₂ may be preferably used. In the case of the Mg metal salt, Mg (NO ₃ ) ₂ , MgCl ₂ , MgSO ₄ , or a hydrate thereof may be used, but Mg (NO ₃ ) ₂ may be preferably used. In the case of the Cu metal salt, Cu (NO ₃ ) ₂ , CuSO ₄ , CuCl ₂ , or a hydrate thereof may be used, but Cu (NO ₃ ) ₂ may be preferably used.

As the trivalent metal salt, Al ³⁺ , Cr ³⁺ , Fe ³⁺ , Ga ³⁺ , In ³⁺ , V ³⁺ , or Ti ^{3+ may be} used as a cation, and NO ₃ ⁻ , Cl ⁻ , OH ⁻ , O ^2- , SO ₄ ^2- , CO ₃ ^2- or a salt compound having succinate as an anion may be used, but is not limited thereto. In the case of the metal salt of Al, Al (OH) ₃ , Al (NO ₃ ) ₃ , Al ₂ (SO ₄ ) ₃ , or a hydrate thereof may be used, but Al (NO ₃ ) ₃ may be preferably used. . In the case of the Fe metal salt, Fe (NO ₃ ) ₃ , FeCl ₃ , Fe ₂ (SO ₄ ) ₃ , or a hydrate thereof may be used, but Fe (NO ₃ ) ₃ may be preferably used.

In the above production method, a solvent for preparing a solution of a divalent metal salt or a solution of a phenolic acid ultraviolet absorber and a divalent metal salt may be a solvent capable of dissolving both the phenolic acid ultraviolet absorber and the metal salt without being involved in the reaction. There is no particular limitation, and for example, a mixed solvent of water, ethanol, water and ethanol, methylene chloride, methanol, methylene chloride, acetone, ethylene glycol, glycerol, or a combination thereof may be used.

Sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, or ammonia may be used as a base for adjusting the pH of the solution of the divalent metal salt or the phenolic acid ultraviolet absorber and the solution of the divalent metal salt, but is not limited thereto. no. The pH control range may be 4-10, but the pH control range may vary depending on the type of specific metal salt, preferably in the production of metal double layer hydroxide to pH 8-10, preferably in the preparation of basic metal salts. May be adjusted to pH 5-8. If the solution is outside the pH control range, the phenolic acid ultraviolet absorber is not introduced between the layers of the layered metal hydroxide, and thus the hybrid may not be prepared.

In the above production method it is possible to adjust the particle size of the hybrid prepared according to the reaction conditions. In the preparation method, as the reaction temperature of the step of forming a precipitate is increased, the reaction time may be increased, the particle size of the prepared hybrid may be increased, and the reaction temperature may be obtained in order to obtain particles having an appropriate dispersibility. Can be -5 ° C or more and 50 ° C or less, preferably 10 ° C or more and 25 ° C or less, and the reaction time can be 1 hour or more, preferably 6 to 24 hours. The step of forming a precipitate in the production method is preferably carried out by continuously adding and shielding nitrogen or inert gas during the reaction.

In order to control the dispersibility according to the type of dispersion medium of the nanocomposite according to the present invention, the surface of the nanocomposite may be modified with another material, and the nanocomposite having such a surface modified

One dispersion selected from the group consisting of tocopherol, lauric acid, tetraethyl orthosilicate (TEOS), glyceryl monostearate (GMS), and dimethicone is obtained by dispersing the nanocomposite prepared according to the preparation method in an inert solvent. Mixing and stirring with a solution of the above materials;

Washing the stirred liquid mixture with an inert solvent to obtain a slurry; And

The obtained slurry may be prepared by a method further comprising dispersing in an inert solvent and then spray drying.

Ethanol, methanol, methylene chloride, acetone, ethylene glycol, glycerol, or a combination thereof may be used as the inert solvent used for the preparation of the surface-modified hybrid, but is not limited thereto. In addition, the reaction may be carried out at room temperature, and the time for mixing and stirring the dispersion obtained by dispersing the precipitate in an inert solvent with a modifying material may be performed for about 20 minutes to 1 hour.

In another aspect of the present invention, the present invention also provides a composition for blocking UV rays comprising the nano-hybrid according to the present invention.

The composition for blocking ultraviolet rays according to the present invention may vary the blocking range of ultraviolet rays according to the type of phenolic acid ultraviolet absorbent mixed in the nano-hybrid containing, but may block both ultraviolet rays A and ultraviolet rays B. The content of the nano-hybrids included in the composition for sunscreen may vary depending on the desired sunscreen time, but may preferably include about 0.01 to 30% by weight.

The sunscreen composition according to the present invention can be used as a sunscreen cosmetics, can be prepared in any formulation that can be applied to the cosmetic field. Such cosmetic formulations include, but are not limited to, creams, lotions, emulsions, foundations, powders, sprays, and the like. Such formulations may be prepared according to any method well known in the cosmetic art.

As described above, the nanocomposite of the phenolic acid ultraviolet absorber and the layered metal hydroxide provided by the present invention can improve the stability of the phenolic acid ultraviolet absorber unstable to light, air, oxygen, etc. Improved the disadvantage of being easily destroyed or deteriorated by the external environment. Indeed, the nano hybrids according to the present invention have broadened the spectrum of ultraviolet radiation that can be blocked by forming nano hybrids over all regions of UV-A and UV-B. In addition, the phenolic acid ultraviolet absorber, which may cause toxicity to the skin when applied to the skin, is significantly suppressed from being released into the medium by the formation of a hybrid, thereby preventing direct contact with the skin when applied to the skin, thereby irritating the skin. And damage can be minimized. In addition, it is possible to improve the dispersibility in the solvent to be applied by modifying the surface of the hybrid according to the present invention with a predetermined material, it is possible to have a more suitable physical properties for formulation. Therefore, the hybrid of the phenolic acid ultraviolet absorber and the layered metal hydroxide according to the present invention can be said to have improved stability, safety, and ease of preparation compared to conventional organic sunscreens. Less cosmetics can be used.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, these examples are only for the understanding of the present invention, and the scope of the present invention is not limited by them in any sense.

Example 1 Preparation of Nano Hybrids of Caffeic Acid with Metal Double Layer Hydroxide (CA-LDH)

Mg (NO ₃ ) ₂ ㆍ 6H ₂ O (0.1M) and Al (NO ₃ ) ₃ ㆍ 9H ₂ O (0.05M) are dissolved in tertiary distilled water from which carbonate ions (CO ₃ ^2- ) have been removed, and 0.1M NaOH The aqueous solution was titrated to pH 9-10 value to obtain a metal double layer hydroxide formed by precipitation. This was separated by a centrifuge, the unreacted salt was removed by washing, and then the caffeic acid (0.1M) solution dissolved in a mixture of tertiary distilled water and ethanol, in which the carbonate ion (CO ₃ ^2- ) was removed from the obtained metal double layer hydroxide. The precipitate was added by ion exchange for stirring at room temperature for 24 hours, followed by centrifugation and washing to obtain a nano hybrid hybridized with caffeic acid to the metal double layer hydroxide. The whole process was performed under a nitrogen atmosphere to prevent the production of carbonate ions (CO ₃ ^2- ) by carbon dioxide in the air.

Example 2 Preparation of Nano Hybrids of Cumaric Acid with Metal Double Layer Hydroxide (pCA-LDH)

A nanocomposite was prepared in the same manner as in Example 1, except that Coumaric Acid (0.1M) was used instead of Caffeic Acid in Example 1.

Example 3: Preparation of Nano Hybrids of Ferulic Acid with Metal Double Layer Hydroxide (FA-LDH)

Nanocomposite was prepared in the same manner as in Example 1 except that ferulic acid (0.1M) was used instead of caffeic acid in Example 1.

Example 4 Preparation of Nano Hybrids of Zinc Basic Salts of Caffeic Acid (CA-ZBS)

Zn (NO ₃ ) ₂ ㆍ H ₂ O (0.1M) is dissolved in tertiary distilled water from which carbonate ions (CO ₃ ^2- ) are removed, titrated to pH 6-7 with 0.2M aqueous NaOH solution, and precipitated by zinc. Basic salts were formed. After centrifugation, the unreacted salt was removed by washing, and then the solution of caffeic acid (0.1M) dissolved in a mixture of distilled water and ethanol, in which zinc carbonate (CO ₃ ^2- ) was removed, was removed. Precipitation was obtained by adding and stirring at room temperature for 24 hours, followed by centrifugation and washing to obtain a nanocomposite hybridized with caffeic acid. The whole process was carried out in a nitrogen atmosphere to prevent the production of carbonate ions (CO ₃ ^2- ) by carbon dioxide in the air.

Example 5 Preparation of Nanocomposites with Zinc Basic Salts of Coumaric Acid (pCA-ZBS)

Nanocomposites were prepared in the same manner as in Example 4, except that Coumaric Acid (0.1M) was used instead of Caffeic Acid in Example 4.

Example 6 Preparation of Nano Hybrids of Zinc Base Salts of Ferulic Acid (FA-ZBS)

Nanocomposite was prepared in the same manner as in Example 4, except that ferulic acid (0.1M) was used instead of caffeic acid in Example 4.

Test Example 1 X-ray Diffraction Analysis of Nano Hybrids

X-ray diffraction analysis was performed to confirm the crystal structure of the nano hybrids in which the phenolic acid prepared in Examples 1 to 6 hybridized to the layered metal hydroxide. The resulting X-ray diffractogram is shown in FIG. 1.

According to FIG. 1, the interlayer spacing of the layered metal hydroxides on the ( 00l ) plane of each nano hybrid was found to match the molecular size of each hybridized phenolic acid. From these results, it was confirmed that nano hybrids were produced.

Test Example 2: UV-blocking efficacy confirmation test in the UV-A ~ UV-B region

Ultraviolet absorption aspect of the pure phenolic acid solution and the nano-hybrid powders prepared in Examples 1 to 6 using an ultraviolet-visible spectrometer to confirm the UV-blocking efficacy of the nano-hybrids prepared in Examples 1 to 6 Measured.

Caffeic acid (0.001M), Coumaric acid (0.001M), and Ferulic acid (0.001M) were dissolved in purified water, respectively, and purified in aqueous solution of pure phenolic acid using an ultraviolet-visible light spectrometer (Perkin Elmer Lambda 35) from 200 nm to 500 nm. Ultraviolet absorption modulus was measured, and the nano hybrid powders prepared in Examples 1 to 6 were measured by using an ultraviolet-visible spectrometer (Hewlett-Packard 8452, using comparative barium sulfate).

The resulting ultraviolet-visible light absorption spectrum is shown in FIG. 2. Figure 2 is a graph showing the ultraviolet absorption of the pure phenolic acid solution and the nano hybrid powder prepared in Examples 1-6.

According to Figure 2, the nano hybrids prepared in Examples 1-6 show pure phenolic acid dissolved in purified water shows a UV protection effect mainly limited to UV-B, across all areas of UV-A to UV-B It was evaluated to absorb ultraviolet rays. As a result, the nano hybrids in which the phenolic acid hybridized to the layered metal hydroxide according to the present invention have high stability, and thus maintain a UV blocking region, and have a UV blocking effect than pure phenolic acid, which is dissolved in purified water and reduces the UV absorbing region. It can be seen that it is dominant in a wide range of areas. Therefore, it was confirmed that the nano hybrids according to the present invention can be used as a stable and effective sunscreen agent when formulated into cosmetics and the like.

Test Example 3 Phenolic Acid Release Experiment of Phenolic Acid Nano Hybrids

When phenolic acid hybridized to the layered metal hydroxide is released from the nano-hybrids, not only the UV blocking effect is reduced but also the phenolic acid UV absorber is in direct contact with the skin of the human body, which may cause skin irritation. Therefore, experiments were conducted to confirm the degree of phenolic acid release of the nano hybrids prepared in Examples 1 to 6.

After dispersing the nanocomposites prepared in Examples 1 to 6 in tertiary distilled water from which carbonate ions (CO ₃ ^2- ) were removed, the amount of phenolic acid released for a total of 4 hours was measured at regular time intervals. The temperature condition of the release experiment was 38 ℃, the measurement interval of the released phenolic acid was set to 10 minutes interval for the first 30 minutes, then 30 minutes interval thereafter. The measurement results of the phenolic acid released over time are shown in FIG. 3.

Figure 3 is a graph showing the concentration of phenolic acid released over time in the water of the nano-hybrids in Examples 1-6. According to FIG. 3, the nano hybrids prepared in Examples 1 to 6 release the phenolic acid for the first 100 minutes and then almost all reached equilibrium. This confirms that only about 15 to 50% by weight of the phenolic acid of the phenolic acid inserted into the layered metal hydroxide was released. From these results, it can be seen that after the initial radical phenolic acid release, the phenolic acid remains intercalated due to strong electrostatic attraction with the layered metal hydroxide. This allows phenolic acid ultraviolet absorbers to inhibit the release of phenolic acid into the medium due to hybridization with layered metal hydroxides, thereby improving and maintaining UV blocking ability and minimizing direct contact with the skin. It can be seen that it can significantly reduce the skin irritation and toxicity.

FIG. 1 is an X-ray diffraction diagram obtained by X-ray diffraction analysis of a nano hybrid having phenolic acid prepared according to an embodiment of the present invention hybridized to a layered metal hydroxide.

FIG. 2 is an ultraviolet-visible light absorption spectrum obtained by measuring ultraviolet absorption patterns using an ultraviolet-visible light spectrometer for pure phenolic acid and a nano hybrid prepared according to an embodiment of the present invention.

Figure 3 is a graph showing the measurement of the concentration of phenolic acid released over time in the water of the nano- hybrids prepared according to an embodiment of the present invention.

Claims (19)

A nanocomposite of phenolic acid ultraviolet absorber and layered metal hydroxide, wherein a phenolic acid ultraviolet absorber is introduced and hybridized between layers of the layered metal hydroxide. According to claim 1, wherein the layered metal hydroxide is a nano-hybrid, characterized in that the compound represented by the formula (1) or formula (2): [Formula 1] [M (II) _1-x M (III) _x (OH) ₂ ] ^{X +} (A ^n- ) _{X /} nyH ₂ O In Chemical Formula 1, M (II) represents a divalent metal cation; M (III) represents a trivalent metal cation; A is an anionic material, n is the number of charges of the anion; x is a number from 0.01 to 0.5; y is a positive number greater than zero. [Formula 2] [M (II) (OH) _{x '} ] (A ^n- ) _{(2-x') / n} yH ₂ O In Chemical Formula 2, M (II) represents a divalent metal cation; A is an anionic material, n is the number of charges of the anion; x 'is a number greater than 1 and less than 2; y is a positive number greater than zero. The method of claim 2, The divalent metal cation is Mg ²⁺ , Ca ²⁺ , Co ²⁺ , Cu ²⁺ , Ni ²⁺ , or Zn ²⁺ ; The trivalent metal cation is Al ³⁺ , Cr ³⁺ , Fe ³⁺ , Ga ³⁺ , In ³⁺ , V ³⁺ , or Ti ³⁺ ; The anion is ^{_{NO 3 -, Cl -, OH}} -, O 2-, SO 4 2-, or nano hybrid material, characterized in that the CO ₃ ^2-. The nano hybrid according to claim 3, wherein the content of the divalent metal cation is 50 mol% or more based on the total metal ion content. The nanocomposite of claim 1, wherein the phenolic acid ultraviolet absorber is at least one selected from the group consisting of caffeic acid, coumaric acid, and ferulic acid. According to claim 1, wherein the phenolic acid ultraviolet absorber is nano-composites, characterized in that contained in the range of 10 ~ 60 w / w%. The surface of the hybrid of claim 1, wherein the nano hybrid is one or more materials selected from the group consisting of tocopherol, lauric acid, tetraethyl orthosilicate (TEOS), glyceryl monostearate (GMS), and dimethicone. Nanocomposite characterized in that this modified. The nanocomposite of claim 1, wherein the average diameter of the particles of the nanocomposite is in the range of 200 nm to 50 μm. Preparing a solution of phenolic acid ultraviolet absorber and divalent metal salt; And Adding a base to the solution to titrate the pH to 4 to 10 to obtain a precipitate, A method for producing a nano hybrid of a phenolic acid ultraviolet absorber and a layered metal hydroxide, wherein the phenolic acid ultraviolet absorber is introduced between the layers of the layered metal hydroxide and hybridized. Preparing a solution of a divalent metal salt; Adding a base to the solution of the divalent metal salt to titrate the pH to 4 to 10 to form a precipitate; And Adding a phenolic acid ultraviolet absorber solution to the formed precipitate to introduce phenolic acid ultraviolet absorber between the layers of the precipitate by ion exchange with anions present between the layers of the precipitate, A method for producing a nano hybrid of a phenolic acid ultraviolet absorber and a layered metal hydroxide, wherein the phenolic acid ultraviolet absorber is introduced between the layers of the layered metal hydroxide and hybridized. Preparing a solution of a divalent metal salt; Adding a base to the solution of the divalent metal salt to titrate the pH to 4 to 10 to form a precipitate; Calcining the formed precipitate by heat treatment at 250 to 450 ° C. for 2 to 8 hours; And Adding to the calcined precipitate in a phenolic acid ultraviolet absorbent solution and stirring to reconstruction A method for producing a nano hybrid of a phenolic acid ultraviolet absorber and a layered metal hydroxide, wherein the phenolic acid ultraviolet absorber is introduced between the layers of the layered metal hydroxide and hybridized. The method according to any one of claims 9 to 11, further comprising adding a trivalent metal salt in the step of preparing a solution of the divalent metal to prepare a mixed solution of a divalent metal salt and a trivalent metal salt. Way. The divalent metal salt of claim 9, wherein the divalent metal salt is Zn (NO ₃ ), ZnSO ₄ , ZnO, ZnCl ₂ , Zn-succinate, Ca (NO ₃ ) ₂ , CaSO ₄ , CaCO ₃ , CaCl ₂ , Ca (OH) ₂ , Mg (NO ₃ ) ₂ , MgCl ₂ , MgSO ₄ , Cu (NO ₃ ) ₂ , CuSO ₄ , or CuCl ₂ . The method of claim 12, wherein the trivalent metal salt is Al (OH) ₃ , Al (NO ₃ ) ₃ , Al ₂ (SO ₄ ) ₃ , Fe (NO ₃ ) ₃ , FeCl ₃ , or Fe ₂ (SO ₄ ) _3. Method characterized in that. The method of claim 9, wherein the base is sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, or ammonia. A composition for preventing ultraviolet rays, comprising the nanocomposite according to any one of claims 1 to 8. 17. The composition of claim 16, wherein the composition can block both UV-A and UV-B ultraviolet radiation. 17. The composition of claim 16, wherein the nano hybrid is contained in an amount of 0.01 to 30 wt%. The composition of claim 16, wherein the composition is a cosmetic selected from the group consisting of creams, lotions, emulsions, essences, foundations, powders, and sprays.

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