GRAPHIC CARBON NITRID WITH POROUS STRUCTURES

Abstract

GRAPHITICAL CARBON NITRIDE WITH POROUS STRUCTURES The present invention relates mainly to a graphitic carbon nitride with porous structures, the graphitic carbon nitride having at least one heptazine motif and a pore volume greater than 0.0045 cm³ / g, derived from a first type of pore having a specific pore diameter of 1 nm or more and less than 15 nm, and derived from a second type of pore having a specific pore diameter of 15 nm or more and 50 nm or less. The graphitic carbon nitride can provide improved UV absorption properties and exhibit the desired colors. Figure for abstract: none

Description

Title of the invention: GRAPHIC CARBON NITRID WITH POROUS STRUCTURES Technical field

[0001] The present invention relates mainly to a graphitic carbon nitride with porous structures, preferably a graphitic carbon nitride with porous structures for the use of an ultraviolet (UVA and / or UVB) absorbing material in cosmetic products. STATE OF THE ART

[0002] The UV protection effect is one of the essential factors in cosmetic products. Graphitic carbon nitride, which is an inorganic compound, is known to exhibit UV absorption properties. Some documents relating to graphitic carbon nitride have already been published.

[0003] Documents CN103240121A, CN105126893A and CN106423244A, for example, disclose carbon nitride-based materials. However, these documents make no mention of the use of carbon nitrides as ultraviolet-absorbing materials in cosmetic products.

[0004] Furthermore, cosmetic makeup products are used to give keratinous substances, such as skin, particularly facial skin, a desired color appearance, such as a pale color for easy color matching. New environmentally friendly UV-absorbing materials are in demand, especially for cosmetic products. No graphitic carbon nitride that can be used as an ultraviolet-absorbing material and can give keratinous substances a desired color is known. DISCLOSURE OF THE INVENTION

[0005] The objective of the present invention is to provide a graphitic carbon nitride with porous structures, which can provide keratinous materials, in particular human keratinous material such as skin, and keratin fibers such as hair, with protection against UV A and / or B. Another object of the present invention is to provide a carbon nitride having color variations that allow the composition to be adjusted to the desired shade for any application such as cosmetic or paint products or as fillers, in particular in plastics.

[0006] The above objective of the present invention can be achieved by a graphitic carbon nitride with porous structures, the graphitic carbon nitride comprising at least one heptazine motif and having a pore volume greater than 0.0045 cm3 / g derived from a first type of pore having a specific pore diameter of 1 nm or more and less than 15 nm and derived from a second type of pore having a specific pore diameter of 15 nm or more and 50 nm or less.

[0007] The graphitic carbon nitride may include at least one having a pore diameter ranging from 1.5 to 200 nm, preferably from 2 to 150 nm, more preferably from 3 to 100 nm, and even more preferably from 5 to 80 nm.

[0008] Graphitic carbon nitride can have a specific surface area determined by the BET process ranging from 5 to 300 m2 / g, preferably from 15 to 250 m2 / g, and more preferably from 30 to 200 m2 / g.

[0009] Graphitic carbon nitride can have a blank value ranging from -60 to 100, preferably from -40 to 80.

[0010] Graphitic carbon nitride can have an initial absorption front value ranging from 390 to 480 nm, preferably from 395 to 450 nm.

[0011] Graphitic carbon nitride can have a pore volume greater than 0.0055 cm3 / g derived from pores having a specific pore diameter in the range of 1.5 nm to 5 nm.

[0012] Graphitic carbon nitride can have a pore volume greater than 0.0045 cm3 / g derived from pores having a specific pore diameter in the range of 15 nm to 50 nm.

[0013] The present invention also relates to a process for manufacturing graphitic carbon nitride according to the present invention, comprising: i. the preparation of at least one precursor compound; and ii. heating at least one precursor compound to 450 °C or more for at least 1 minute.

[0014] The ii) heating in the process can be carried out in the presence of oxygen-containing species, such as O2 (in particular with oxygen flux) and / or moisture.

[0015] The present invention also relates to a use of graphitic carbon nitride according to the present invention as a paint active, as a pigment, as a filler, in particular of plastics, or as a cosmetic active, in particular as a UV absorber.

[0016] The present invention also relates to a composition comprising graphitic carbon nitride according to the present invention and water and / or at least one organic medium.

[0017] The present invention also relates to a composition, preferably a cosmetic composition for keratinous substances, such as skin, in particular a sunscreen composition, comprising graphitic carbon nitride according to the present invention.

[0018] The composition may not include TiO2 or ZnO, or may include TiO2 and / or ZnO in an amount of 5% by weight or less, more preferably 1% by weight or less, relative to the total weight of the composition. Brief description of the drawings

[0019] [Fig.1] Fig.1 shows (a) the 13C CP / MAS spectra, (b) the 13C DD / MAS spectra and (c) the 15N CP MAS NMR spectra obtained with graphitic carbon nitride according to Example 3.

[0020] [Fig.2] [Fig.2] shows the XRD patterns obtained with carbon nitride graphitic according to Example 3.

[0021] [Fig.3A] [Fig.3B] Figures 3A and 3B show the BJH curves obtained with graphitic carbon nitride according to Comparative Examples 1 and 2 and Examples 1 to 5.

[0022] [Fig.4] Figure [Fig.4] shows the absorption spectra obtained by measuring the diffuse UV-vis reflectance of graphitic carbon nitride powder as synthesized according to Examples 1 to 3.

[0023] [Fig.5] Fig.5 shows the absorption spectra of liquids suspended with 0.01 wt% of graphitic carbon nitride according to Example 3 in (a) water / isopropanol (99:1) and (b) water / propylene glycol (50:50).

[0024] [Fig.6] Fig.6 shows the absorption spectra obtained by diffuse UV-vis transmittance in the wavelength region of 250 nm to 450 nm of graphitic carbon nitride according to Example 3 in comparison with TiO2 (average size of primary particles: 15 nm) and ZnO (average size of primary particles: 20 nm).

[0025] [Fig.7] Figure [Fig.7] shows the UV-vis absorption spectrum obtained by measuring the diffuse transmittance of the sample obtained by applying to a 30 mg PMMA plate of the water dispersion comprising 1 wt% of graphitic carbon nitride according to Example 3 and 1 wt% of hydroxyethylcellulose. Best embodiment of the invention

[0026] After extensive research, the inventors surprisingly discovered that a new structure of graphitic carbon nitride can exhibit a desired colour appearance as well as a UV A and / or B absorption property and that it is perfectly suited for cosmetic use, and thus finalized the invention.

[0027] Thus, the present invention relates mainly to a graphitic carbon nitride with porous structures, the graphitic carbon nitride having at least one heptazine motif and having a pore volume greater than 0.0045 cm³ / g derived from a first type of pore having a specific pore diameter of 1 nm or more and less at 15 nm and derived from a second type of pore having a specific pore diameter of 15 nm or more and 50 nm or less.

[0028] Graphitic carbon nitride according to the present invention can provide an improved UV A and / or B absorption property and exhibit a desired color appearance, such as a pale color for easy color adjustment, and is therefore very useful as UV A and / or B absorbers for various products, especially cosmetic products.

[0029] The present invention will be described in detail below. [Graphitic carbon nitride]

[0030] The present invention relates to a graphitic carbon nitride with porous structures, the graphitic carbon nitride having at least one heptazine motif and having a pore volume greater than 0.0045 cm3 / g derived from a first type of pores having a specific pore diameter of 1 nm or more and less than 15 nm and derived from a second type of pores having a specific pore diameter of 15 nm or more and 50 nm or less.

[0031] The term "graphitic" in graphitic carbon nitride here means that the carbon nitride has a structure similar to that of a sheet of graphite. Thus, the graphitic carbon nitride of the present invention has a layered or laminated structure.

[0032] The graphitic carbon nitride of the present invention comprises at least one heptazine motif. In this specification, the heptazine motif refers to a fused heterocycle consisting of three heterocycles composed of C and N atoms, represented by C6N7. Thus, the graphitic carbon nitride of the present invention has a heptazine-based monolayer structure. The graphitic carbon nitride of the present invention may comprise at least one heptazine motif, at least one triazine motif, and one of their combinations. The presence of the heptazine motif can be determined by X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy analysis, and nuclear magnetic resonance (NMR) spectroscopy analysis.

[0033] The inventors of the present application produced graphitic carbon nitrides with several heating processes, and were astonishing to discover that the graphitic carbon nitrides of the present invention exhibit the very unique structure with at least one heptazine motif by X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR) spectroscopy analysis and solid-state nuclear magnetic resonance (NMR) spectroscopy analysis.

[0034] In one embodiment of the present invention, the graphitic carbon nitride of the present invention has a stacked or layered structure of superimposed graphitic carbon nitride sheets. In other words, the graphitic carbon nitride of the present invention can have a multilayered sheet structure of graphitic carbon nitride. The stacked structure of the graphitic carbon nitride sheets can be determined by X-ray diffraction (XRD) analysis and by nuclear magnetic resonance (NMR) spectroscopy analysis.

[0035] The graphitic carbon nitride of the present invention has a porous structure. More specifically, the graphitic carbon nitride of the present invention has a nanoporous structure. The pores may exist between the heptazine motifs and / or between the layers of the graphitic carbon nitride sheets.

[0036] The heptazine motif is preferably represented by formula (I), its salts and its solvates such as hydrates:

[0037] Formula (I) in which R1, R2, and R3, identical or different, represent: i. a hydrogen atom, ii. a halogen atom, iii. an oxygen-containing group such as the carboxy, nitro or nitroso group, iv. a saturated or unsaturated, acyclic linear or branched and / or cyclic, aromatic or non-aromatic hydrocarbon chain containing from 1 to 10 carbons, said hydrocarbon chain being potentially interrupted by one or more heteroatoms such as O, S, N or N(O); v. a hydroxy, vi. an amino R4R5N-, where R4 and R5, identical or different, represent a hydrogen atom, an alkyl group (Ci-C6) or another monovalent heptazine group, preferably a monovalent heptazine group (II) R1 in which R1 and R2 are as defined here .xr 'N r2 previously; vii. R4R5 N(O)-, in which R4 and R5, whether identical or different, are as defined herein previously; and viii. R4 -N(O)- or ; in which R4 is such as defined here previously ;

[0038] it being understood that:

[0039] - at least one of the radicals R1, R2 or R3 represents v) a hydroxy group, more preferably RI represents v) a hydroxy group and R2 and R3, identical or different, preferably identical, represent iii) a nitroso group chosen from vi) to viii), more preferably viii), and

[0040] - one or more nitrogens in the rings can be oxidized (N-oxide, or N-OH).

[0041] The ii) halogen can be chosen from Cl and Br.

[0042] The iii) hydrocarbon chain may be a saturated or unsaturated hydrocarbon chain, preferably saturated, linear acyclic or branched, preferably linear acyclic. The iii) hydrocarbon chain may contain from 1 to 6, preferably from 1 to 4, carbon atoms. Thus, the iii) hydrocarbon chain may be a saturated, linear, acyclic hydrocarbon chain containing from 1 to 6, preferably from 1 to 4, carbon atoms, which may be interrupted by one or more heteroatoms such as O, S, N, or N(O).

[0043] More preferably, R1, R2, and R3, identical or different, represent an atom or a group chosen from i) a hydrogen, v) a hydroxy, vi) an amino R4R5N-, in which R4 and R5, identical or different, represent a hydrogen atom, or another monovalent heptazine group (II) in which R1 and R2 are as defined herein above; and viii) a nitroso R4-N(O)- in which R4 is as defined herein above.

[0044] Preferably, at least one of the radicals R1, R2 or R3 represents v) a hydroxy group.

[0045] The graphitic carbon nitride of the present invention is solid at room temperature and generally in powder form. Graphitic carbon nitride can be suspended in water and in organic media, such as polar oils, including diisopropyl sebacate. Without wishing to theorize, it is thought that the reason why the graphitic carbon nitride of the present The invention is that the graphitic carbon nitride contains functional groups including amino groups at the edges of the graphitic carbon nitride sheets and those produced by discretization and / or cracking occurring in the heptazine motifs, which can contribute to a change in hydrophilicity and hydrophobicity of the surface of the graphitic carbon nitride.

[0046] The graphitic carbon nitride according to the present invention may include at least one pore having a pore diameter greater than 1.13 nm. Preferably, the graphitic carbon nitride includes at least one pore having a diameter of 1.5 nm or more, more preferably 2 nm or more, and more preferably 3 nm or more, and even more preferably 5 nm or more, and in particular 10 nm or more. The upper limit of the pore diameter included in the graphitic carbon nitride is not particularly limited, but is generally 500 nm or less, preferably 400 nm or less, more preferably 300 nm or less, and even more preferably 200 nm or less.

[0047] The pore diameter included in the graphitic carbon nitride according to the present invention can range from 1 to 500 nm, preferably from 2 to 400 nm, more preferably from 3 to 300 nm, and even more preferably from 5 to 200 nm.

[0048] The graphitic carbon nitride according to the present invention can have a specific surface area determined by the BET process of 5 m2 / g or more, preferably of 15 m2 / g or more, and more preferably of 30 m2 / g or more, and can have a specific surface area determined by the BET process of 300 m2 / g or less, preferably of 250 m2 / g or less, and more preferably of 200 m2 / g or less.

[0049] The graphitic carbon nitride according to the present invention can have a specific surface area determined by the BET process ranging from 5 to 300 m2 / g, preferably from 15 to 250 m2 / g, and more preferably from 30 to 200 m2 / g.

[0050] In certain embodiments of the present invention, the graphitic carbon nitride according to the present invention can have a specific surface area determined by the BET process ranging from 40 to 200 m2 / g, preferably from 45 to 190 m2 / g, and more preferably from 50 to 180 m2 / g.

[0051] The graphitic carbon nitride according to the present invention has a characteristic in its porous structure in that it has a large volume of pores having a specific pore diameter included in two regions of different pore sizes. The different pore size regions may include the first type of pores having a specific pore diameter of 1 nm or more and less than 15 nm and the second type of pores having a specific pore diameter of 15 nm or more and 50 nm or less.

[0052] More specifically, the graphitic carbon nitride according to the present invention has a characteristic in its porous structure in that it has a pore volume greater than 0.0045 cm³ / g derived from the first type of pores having a specific pore diameter of 1 nm or more and less than 15 nm, and derived from the second type of pores having a specific pore diameter of 15 nm or more and 50 nm or less. This means that the graphitic carbon nitride has a pore volume greater than 0.0045 cm³ / g derived from the first type of pores having a specific pore diameter of 1 nm or more and less than 15 nm, and that the graphitic carbon nitride has a pore volume greater than 0.0045 cm³ / g derived from the second type of pores having a specific pore diameter of 15 nm or more and 50 nm or less.

[0053] In one embodiment, the graphitic carbon nitride according to the present invention has a pore volume greater than 0.0055 cm³ / g derived from pores having a specific pore diameter in the range of 1.5 nm to 10 nm, preferably 1.5 nm to 5 nm. This may mean that the first type of pore has a specific pore diameter in the range of 1.5 nm to 10 nm, preferably 1.5 nm to 5 nm.

[0054] In another embodiment, the graphitic carbon nitride according to the present invention has a pore volume greater than 0.0055 cm3 / g derived from pores having a specific pore diameter in the range of 1.5 nm to 5 nm which may be the first type of pores.

[0055] In yet another embodiment, the graphitic carbon nitride according to the present invention has a pore volume greater than 0.0045 cm³ / g derived from pores having a specific pore diameter in the range of 20 nm to 45 nm. This may mean that the second type of pore has a specific pore diameter in the range of 20 nm to 45 nm.

[0056] In yet another embodiment, the graphitic carbon nitride has a pore volume greater than 0.0050 cm3 / g, preferably 0.0055 cm3 / g, and more preferably 0.0060 cm3 / g derived from pores having a specific pore diameter.

[0057] In the present invention, the quantity of pores having a specific pore diameter and the specific surface area of ​​the graphitic carbon nitride can be determined by analyzing the pore size distribution curves obtained from the nitrogen adsorption-desorption isotherm measured using a surface area and porosity analyzer. The quantity of pores having a specific pore diameter included in the graphitic carbon nitride can be determined using the Barrett-Joyner-Halenda (BJH) method on the obtained pore size distribution curves. The specific surface area of ​​the graphitic carbon nitride can be determined using the Brunauer-Emmett-Teller (BET) method on the obtained pore size distribution curves.

[0058] The graphitic carbon nitride of the present invention may have a pale color for easy color matching, which is suitable and desirable for cosmetic products. In preferred embodiments of the present invention, the graphitic carbon nitride may have a white color, which is desirable for use in cosmetic products as a replacement for ZnO.

[0059] The whiteness of graphitic carbon nitride can be defined by a whiteness value. The whiteness value can be measured using a UV-Vis diffuse reflectance spectrometer. The whiteness value of graphitic carbon nitride can range from -60 to 100, preferably from -40 to 80. In preferred embodiments of the present invention, graphitic carbon nitride has a whiteness value of -30 or higher. The highest whiteness value indicates the whitest appearance of the graphitic carbon nitride.

[0060] The graphitic carbon nitride of the present invention may exhibit the property of absorbing UV A and / or UV B. In general, the graphitic carbon nitride of the present invention may exhibit the property of absorbing UV rays having a wavelength less than 400 nm. Preferably, the graphitic carbon nitride exhibits the absorption effect in both the UV-B and UV-A regions. UV-B rays here refer to UV rays having a wavelength between 280 and 320 nm. UV-A rays here refer to UV rays having a wavelength between 320 and 400 nm.

[0061] The UV absorption property of the graphitic carbon nitride of the present invention can be represented by an initial absorption front value (nm). The initial absorption front value can be defined with a wavelength (nm) at the intersection of a straight line drawn to fit a region where an absorbance curve drops sharply from a shorter wavelength side of an absorbance curve, and a straight line drawn to fit an absorbance curve in a certain range of wavelengths between 500 and 650 nm, where the absorbance curve becomes consistently low.

[0062] Example 3 of [Fig. 4] represents an example of the initial absorption property of 405 nm, which is a wavelength at the intersection of (1) a straight line drawn to fit a region where the absorbance curve drops sharply from a shorter wavelength side of the absorbance curve, and (2) a straight line drawn to fit the absorbance curve in a certain range of wavelengths between 500 and 650 nm, where the absorbance curve becomes consistently low. An absorption curve in a range of ultraviolet and visible light can be measured, for example, by ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy. The value of the initial absorption front higher indicates the longest wavelength of rays that graphitic carbon nitride can filter.

[0063] The graphitic carbon nitride of the present invention may have an initial absorption front value of 390 nm or more, preferably 395 nm or more. The graphitic carbon nitride of the present invention may have an initial absorption front value of 480 nm or less, preferably 450 nm or less.

[0064] The graphitic carbon nitride of the present invention can have an initial absorption front value ranging from 390 to 480 nm, preferably from 395 to 450 nm.

[0065] The graphitic carbon nitride of the present invention may or may not be surface-treated with a surface treatment agent. Preferably, the graphitic carbon nitride is not surface-treated with a surface treatment agent.

[0066] Without wishing to develop a theory, it is estimated that the fact that the graphitic carbon nitride of the present invention possesses the characteristic porous structure contributes to the colored appearance of the graphitic carbon nitride, which is suitable for cosmetic products. It is deduced that there are chemical bond cracks in the heptazine motifs in the porous graphitic carbon nitride according to the invention, such as chemical bond cracks between carbon atoms and nitride atoms. It is believed that these cracks can produce a wider band gap in the graphitic carbon nitride, leading to the characteristic colored appearance of the graphitic carbon nitride according to the present invention. Given that the graphitic carbon nitride of the present invention has a relatively large pore volume, it is estimated that there are a large number of chemical bond cracks in the heptazine motifs. [Manufacturing process]

[0067] The present invention also relates to a manufacturing process for the graphitic carbon nitride of the present invention.

[0068] More specifically, the present invention also relates to a process for manufacturing the graphitic carbon nitrides of the present invention, comprising: i. the preparation of at least one precursor compound; and ii. heating at least one precursor compound to 450 °C or more for at least 1 minute.

[0069] Graphitic carbon nitride can be prepared by heating at least one precursor compound of graphitic carbon nitride. One precursor compound can be used as the starting material for graphitic carbon nitride, or two or more precursor compounds can be used in combination.

[0070] The precursor compound may be chosen from, for example, urea, thiourea, melamine, guanidine, arginine, cyanamide, dicyandiamide, and one of their salts, and their combinations. Preferably, the precursor compound is chosen from urea, melamine, guanidine, arginine and one of their salts, and their combinations, and in particular, chosen from melamine, urea and one of their salts, and their combinations.

[0071] The salt of the precursor compound is not particularly limited, but examples include salts with inorganic acids, such as carbonic acid and hydrochloric acid.

[0072] In a preferred embodiment of the present invention, a single precursor compound is used as a raw material for the preparation of graphitic carbon nitride.

[0073] The heating temperature of at least one precursor compound is at least 450 °C. Preferably, the heating is carried out at 500 °C or more, and more preferably at 525 °C or more.

[0074] The heating time of at least one precursor compound is at least 1 minute. Preferably, the heating time is at least 10 minutes, more preferably at least 20 minutes, and / or up to 30 hours, and more preferably up to 25 hours.

[0075] The heating of the precursor compound can be carried out in air, in a noble gas, such as argon or helium, or in an inert gas, such as nitrogen. In preferred embodiments of the present invention, the heating of the precursor compound is carried out in air or in argon.

[0076] In a preferred embodiment, the heating process can be carried out in the presence of oxygen-containing species, such as O2, moisture, O3, atomic O, and / or ionic oxygen, as an oxidizing agent. Without wishing to elaborate on this, it is estimated that a more porous graphitic carbon nitride can be obtained when heating is carried out in the presence of an oxygenated species. In the preferred embodiment, the heating is carried out in air, or in a noble gas or an inert gas, including oxygen-containing species.

[0077] In a preferred embodiment, in addition to oxygen in the air, the heating process is carried out in the presence of oxygen-containing species, such as O2, moisture, ozone O3, atomic O and / or ionic oxygen, as an oxidizing agent.

[0078] In a preferred embodiment, the heating process is carried out in the presence of O2-containing species, in particular an oxygen flow, and / or moisture. The term "oxygen flow" may mean an oxygen stream in this specification.

[0079] Preferably, the oxidizing agent used during the heating step is in gaseous form.

[0080] According to one embodiment, the oxygen source is neither from the permanganate salt nor from hydrogen peroxide.

[0081] In one embodiment of the present invention, the heating process includes at least two heating steps at the same or different temperatures. In other words, the heating process may include a post-heating step. Thus, in one embodiment, the heating process may comprise a first heating step of at least one precursor compound at 450 °C or higher for at least 1 minute, followed by a second heating step of at least one precursor compound at 450 °C or higher for at least 1 minute. The temperature for the first heating step and the temperature for the second heating step may be the same or different, but generally, the temperature for the second heating step is equal to or higher than the temperature for the first heating step. The temperature and duration of the first and second heating steps are the same as those explained above.

[0082] In one embodiment of the present invention, a cooling step is present between the heating steps. Thus, in one embodiment, the cooling step is included between the first heating step and the second heating step. The temperature of the cooling step is not particularly limited, but, for example, the temperature is cooled to ambient temperature (approximately 25 °C). The duration of the cooling step is not particularly limited, but is, for example, from approximately 1 minute to 24 hours. [Use]

[0083] The present invention may relate to the use of the graphitic carbon nitride of the present invention as UV A and / or B absorbers in order to protect products from damage caused by UV A and / or B radiation. For example, the UV A and / or B absorber of the present invention may be used in paints, coatings and cosmetics.

[0084] Since the graphitic carbon nitride of the present invention can exhibit improved UV A and / or B absorption properties, the use of the present invention can provide an enhanced protective effect with the products to be used. Furthermore, since the graphitic carbon nitride of the present invention can exhibit colors suitable for cosmetics, the use of the present invention can provide the products with the desired colorful and attractive appearance. [Composition]

[0085] The present invention also relates to a composition including the graphitic carbon nitride of the present invention.

[0086] Since the graphitic carbon nitride according to the present invention can be suspended in water and in organic media, the present invention relates to a composition comprising the graphitic carbon nitride according to the present invention and water and / or at least one organic medium. In this embodiment, the composition according to the present invention may be a suspension of graphitic carbon nitride in water and / or in an organic medium.

[0087] Examples of organic media include monoalcohols, such as Ci-C6 monoalcohols, for example ethanol and propanol; polyols, such as Ci-C6 polyols, for example glycerin; and Cl-C6 alkylene glycols, for example ethylene glycol and propylene glycol; and mixtures thereof.

[0088] Similarly, the composition according to the present invention is a cosmetic composition, in particular a cosmetic composition for keratinous substances, such as skin. In a preferred embodiment, the composition according to the present invention is a sunscreen composition.

[0089] The composition according to the present invention preferably does not comprise TiO2 or ZnO. In another embodiment, the composition according to the present invention comprises TiO2 and / or ZnO in an amount of 5% by weight or less, more preferably 1% by weight or less, relative to the total weight of the composition. The graphitic carbon nitride of the present invention can be used in the composition in place of TiO2 and ZnO, which are known as traditional inorganic UV filters.

[0090] Since the graphitic carbon nitride of the present invention can exhibit improved UV absorption properties, the composition of the present invention can provide enhanced UV protection. Furthermore, because the graphitic carbon nitride of the present invention can exhibit colors suitable for cosmetics, the cosmetic composition according to the present invention can give keratinous substances a desired colored and attractive appearance. EXAMPLES

[0091] The present invention will be described in more detail by means of examples. However, these examples should not be interpreted as limiting the scope of the present invention. [Preparation]

[0092] Graphitic carbon nitride according to the present invention in powder form was prepared in Examples 1 to 5 and the following comparative examples 1 and 2. Comparative example 1

[0093] Different weights in the range of 3 g to 5 g of melamine powder as precursor compound were heated to 550 °C in air for 2 hours, then were thoroughly mixed to obtain the graphitic carbon nitride according to Comparative Example 1. Comparative example 2

[0094] 3 g of melamine powder as a precursor compound were heated to 600 ° C in an argon gas flow (200 ml / min) for 8 hours to obtain the graphitic carbon nitride according to the comparative example. Example 1

[0095] 5 g of melamine powder as a precursor compound were heated to 550 ° C in air for 2 hours then at 600 °C in air for 16 hours to obtain the graphitic carbon nitride according to Example 1. Example 2

[0096] 5 g of melamine powder as a precursor compound were heated to 550 ° C in air for 2 hours then at 600 °C in air for 19 hours to obtain the graphitic carbon nitride according to Example 2. Example 3

[0097] Different weights in the range of 1 g to 10 g of urea powder as precursor compound were heated to 600 to 605 °C in air for 2 hours, then were mixed thoroughly to obtain the graphitic carbon nitride according to Example 3. Example 4

[0098] 10 g of urea powder as a precursor compound were heated to 550 °C in air for 1 hour and then at 600 °C in air for 30 minutes in air to obtain the graphitic carbon nitride according to Example 4. Example 5

[0099] 10 g of urea powder as a precursor compound were heated to 600 °C in air for 2 hours, cooled to room temperature, then heated to 600 °C in air for 1 hour to obtain graphitic carbon nitride according to Example 5. [Evaluation]

[0100] (Morphology and crystal structure, and chemical structure)

[0101] The morphology of each of the graphitic carbon nitrides was observed using a field emission scanning electron microscope (FE-SEM). The crystal structure of each of the graphitic carbon nitrides was characterized using X-ray diffraction (XRD) analysis. In the XRD model, the 13° peak was attributed to (100) graphitic carbon nitride having heptazine motifs; the 27° peak was attributed to the (002) plane of the c-axis in stacked sheets of graphitic carbon nitride, according to Luhong Zhang et al. (ACS Omega, 2018, 3(11), 15009-15017). The appearance of these peaks indicates the presence of stacked sheets of graphitic carbon nitride having heptazine motifs.

[0102] The chemical structure of each of the graphitic carbon nitrides was characterized by solid-state nuclear magnetic resonance (NMR) spectroscopy using an Avance 400 (Bruker Corporation) and Fourier transform infrared (FTIR) spectroscopy. The solid-state NMR spectra were acquired by cross-polarization / magic-angle rotation (CP / MAS) and dipolar decoupling / magic-angle rotation (DD / MAS) methods.

[0103] [Fig.1] shows (a) the 13C CP / MAS spectra, (b) the 13C DD / MAS spectra and (c) the 15N CP MAS NMR spectra representative of graphitic carbon nitride according to Example 3.

[0104] The peaks appearing at (Cl) and (C2) in both the 13C CP / MAS and DD / MAS NMR spectra shown in [Fig. 1] have been respectively attributed to (Cl) carbon atoms close to two pyridinic nitrogen atoms in heptazine motifs comprising graphitic carbon nitride and a nitrogen atom in the amino group and (C2) carbon atoms close to two pyridinic nitrogen atoms and a central nitrogen atom in heptazine motifs, according to Barbara Jürgens et al (J. Am. Chem. Soc., 2003, 125(34), 10288-10300) and Bettina V. Lotsch et al. (Chem. Eur. J., 2007, 13(17), 4969-4980). For the 13C CP / MAS process, sensitivity is improved by using proton magnetization transfer, while sensitivity is higher for carbon and nitrogen atoms located closer to the protons. Semi-quantitative analysis was performed by setting the pulse delay to 4000 seconds for the 13C DD / MAS process.The peaks appearing at (NI), (N2), (N3), and (N4) in the CP / MAS 15N spectra shown in [Fig. 2] were respectively attributed to (NI) pyridinic nitrogen atoms, (N2) central nitrogen atoms in the heptazine motifs, (N3) secondary amino groups crosslinking the heptazine motifs, and (N4) nitrogen atoms in the primary amino groups at the boundary within the heptazine motif comprising graphitic carbon nitride. The IR spectra were obtained using the attenuated total reflection (ATR) method. The peak attributed to the heptazine motifs appears at 804 cm⁴, which is a higher wavenumber than that of the triazine motifs (814 cm⁻¹ for melamine, 808 cm⁻¹ for melame), according to Nan Liu et al. (ACS Omega, 2020, 5, 12557–12567). .

[0105] According to these analyses on the graphitic carbon nitride according to Example 4, all the peaks that appeared were attributed to the C and N atoms in the heptazine motifs. It was thus confirmed that the graphitic carbon nitride of the prior invention exhibits multilayer sheets of graphitic carbon nitride with heptazine motifs. The same results are obtained in the graphitic carbon nitride according to the other examples.

[0106] Figure 2 shows the representative XRD motifs of graphitic carbon nitride according to Example 3. The peak attributed to (100) of graphitic carbon nitride having heptazine motifs and the peak attributed to the (002) plane appeared, indicating the presence of stacked sheets of graphitic carbon nitride having heptazine motifs. The same results are obtained in graphitic carbon nitride according to the other examples.

[0107] (UV absorption property and white value)

[0108] The light absorption performance of each of the graphitic carbon nitrides in the ultraviolet and visible light wavelength range was evaluated using ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy (UV2500PC, Shimadzu Corporation) equipped with an integrating sphere.

[0109] The UV-Vis absorption spectra of liquids suspended with 0.01 wt% of each of the graphitic carbon nitrides in a fine quartz cell (two transparent sides, 2 mm (optical path length) x 10 mm x H45 mm, Tokyo Garasu Kikai Co., Ltd.) were collected using a UV-Visible spectrophotometer (V750, Jasco Inc.) equipped with an integrating sphere. Water / isopropanol (99:1 wt), water / PG (a volume ratio of 50:50), or water alone were used as the suspension medium. The initial adsorption front was estimated from the diffuse UV / Vis reflectance spectrum of each sample.

[0110] The white point value was also evaluated from the diffuse UV-vis reflectance spectrum of each sample. The calculation of the white point value was performed using the Shimadzu software installed on the instrument, where illuminant D65 was used as the standard illuminant and a viewing angle was set to 100°. The BaSO4 standard white plate was used as a reference.

[0111] Diffuse transmittance in the wavelength range of 250 nm to 450 nm on polymethyl methacrylate (PMMA) plates (50 mm x 50 mm, Helioplate HD6; Helioscreen) was measured using the UV-2000S in vitro sunscreen analyzer (Labsphere, Inc.) equipped with an integrating sphere. The graphitic carbon nitride powder sample was dispersed in (a) diisopropyl sebacate and (b) water with hydroxyethylcellulose. Then, 30 mg of the dispersions were applied to the PMMA plates and the solvents were dried.

[0112] (Porosity and specific surface area)

[0113] The porosity and specific surface area of ​​each graphitic carbon nitride were evaluated using a nitrogen adsorption-desorption isotherm. The sample was introduced into a quartz tube. The tube was evacuated to 423 K for 5 hours using a vacuum degasser as a pretreatment step. The tube was then cooled to room temperature and purged with helium gas. The tube then The tube was connected to a surface area and porosity analyzer. It was evacuated and cooled to 77 K, and then nitrogen was gradually introduced to collect the adsorption-desorption isotherm. Porosity was assessed using Barrett-Joyner-Halenda (BJH) pore size distribution plots derived from the adsorption-desorption isotherm curves. Specific surface area was determined from the adsorption isotherm using Brunauer-Emmett-Teller (BET) theory.

[0114] The BJH graphs obtained according to Examples 1 to 5 and Comparative Examples 1 and 2 are shown in Figures 3(A) and 3(B). As these BJH curves show, the characteristic structures have been confirmed.

[0115] Graphitic carbon nitride according to Comparative Example 1 comprised pores of a diameter size in the range of 2 nm to 50 nm with a pore volume in the range of 0.00035 cm3g 'nm1 to 0.0018 cm3g 'nm*.

[0116] Graphitic carbon nitride according to Comparative Example 2 comprised pores of a diameter size in the range of 4 nm to 59 nm with a pore volume in the range up to 0.0019 cm3g 'nm*.

[0117] The graphitic carbon nitride according to Example 1 comprised pores with a diameter size in the range of 2 nm to 50 nm with a pore volume in the range of 0.0028 cm3g'nm1 to 0.0068 cm'g'nm1. In particular, the pore volumes having a diameter size of about 2 nm, about 3 nm and about 20 nm were respectively as large as 0.0064 cm g nm, 0.0068 cm g nm and 0.0061 cm g nm1.

[0118] The graphitic carbon nitride according to Comparative Example 2 comprised pores with a diameter size in the range of 2 nm to 50 nm with a pore volume in the range of 0.0021 cm3g 'nm1 to 0.0074 cm3g 'nm'. In particular, the volumes of pores having a size of about 3 nm, about 4 nm and 44 nm were respectively as large as 0.0074 cm3g 'nm', 0.0057 cm3g 'nm1 and 0.0049 cm3g 'nm*.

[0119] The graphitic carbon nitride according to Example 3 comprised pores of a diameter size in the range of 2 nm to 38 nm with a pore volume in the range of 0.0025 cm3g 'nm1 to 0.0225 cm'g'nm1.

[0120] The graphitic carbon nitride according to Example 4 comprised pores with a diameter size in the range of 1 nm to 44 nm with a pore volume in the range of 0.0021 cm3g'nm1 to 0.0066 cm3g'nm1. In particular, the pore volume having a diameter size of about 3 nm and about 28 nm was respectively as large as 0.058 cm3g'nm1 and 0.0066 cm3g'nm*.

[0121] The graphitic carbon nitride according to Example 5 comprised pores of a diameter size in the range of 2 nm to 44 nm with a pore volume in the range of 0.005 cm3g 'nm 1 to 0.0176 cm3g 'nm '.

[0122] Thus, the graphitic carbon nitride according to each of Examples 1 to 5 had a characteristic porous structure which has a pore volume greater than 0.0045 cm3 / g derived from the first type of pores having a specific pore diameter of 1 nm or more and less than 15 nm, and derived from the second type of pores having a specific pore diameter of 15 nm or more and 50 nm or less.

[0123] Similarly, the results are summarized in Table 1 below.

[0124] [Tables 1] Precursor Heating conditions Initial absorption frontage value (nm) Blane value Specific surface area (m2 / g) Comp. ex. 1 Melamine 550 °C, 2 h, in air 443 -59 12 Comp. ex. 2 Melamine 600 °C, 8 h, in argon 460 -142 3 Ex. 1 Melamine 550 °C, 2 h 600 °C, 16 h, in air 408 -13 59 Ex. 2 Melamine 550 °C, 2 h 600 °C, 19 h, in air 400 66 56 Ex. 3 Urea 600-605 °C, 2 h, in air 405 62 168 Ex. 4 Urea 550 °C, 1 h 600 °C, 30 min, in air 437 -24 54 Ex. 5 Urea 600 °C, 2 h rt -> 600 °C, 1 h, in air 406 42 150

[0125] Table 1 shows that graphitic carbon nitride having a favorable white value has an initial absorption front value of less than 443 nm and a specific surface area greater than 12.

[0126] (Comparison of UV absorption properties)

[0127] The absorption spectra obtained by measuring the diffuse UV-vis reflectance of the graphitic carbon nitride powder as synthesized according to Examples 1 to 3 are shown in [Fig. 4] as representative examples. All samples of powders exhibited absorption in the UV wavelength range, which is less than 400 nm.

[0128] The absorption spectra of liquids suspended with 0.01 wt% of graphitic carbon nitride according to Example 3 in water / isopropanol (99:1) and water / propylene glycol (50:50) are shown in [Fig. 5] as a representative example. All these suspensions exhibited absorption in the UV wavelength range, which is less than 400 nm.

[0129] The diffuse transmittance in the wavelength region from 250 nm to 450 nm of graphitic carbon nitride according to Example 3, which was suspended in an oil-based medium and then applied to a polymethyl methacrylate (PMMA) plate for sunscreen evaluation, was compared to that of TiO2 (average primary particle size: 15 nm) and ZnO (average primary particle size: 20 nm), which are commonly used as inorganic UV filters. Each of the samples was dispersed in diisopropyl sebacate to obtain suspensions comprising 3 wt% of graphitic carbon nitride. Next, 30 mg of the suspension were applied to a polymethyl methacrylate (PMMA) plate (50 mm x 50 mm, Helioplate HD6; Helioscreen), and the diffuse transmittance in the wavelength region from 250 nm to 450 nm was measured using the UV-2000S in vitro sunscreen analyzer (Labsphere, Inc.).The result is illustrated in [Fig. 6]. As can be seen in [Fig. 6], it is clear that the graphitic carbon nitride of the present invention could exhibit an absorption property superior to that of TiO2 and ZnO in the UV wavelength region below 400 nm.

[0130] The diffuse transmittance in the wavelength range of 250 nm to 450 nm of graphitic carbon nitride according to Example 3, which was suspended in a water-based medium and then applied to a PMMA plate for sunscreen evaluation, also showed a UV absorption property. The sample was dispersed in water containing 1 wt% hydroxyethylcellulose to obtain a suspension comprising 1 wt% of graphitic carbon nitride. Then, 30 mg of the suspension were applied to a PMMA plate (50 mm x 50 mm, Helioplate HD6; Helioscreen), dried for a certain time, and the diffuse transmittance in the wavelength range of 250 nm to 450 nm was measured using the UV-2000S in vitro sunscreen analyzer (Labsphere, Inc.). The result is illustrated in [Fig.7].As can be seen from Figure 8, it is clear that the graphitic carbon nitride of the present invention can exhibit an absorption property in the UV wavelength region below 400 nm.

[0131] Consequently, it can be concluded that the graphitic carbon nitride of the present invention is very useful as a UV absorber for various products, in particularly for cosmetic products, as it can provide enhanced UV absorption properties and exhibit a desired color, especially for cosmetic use.

Claims

Demands

1. Graphitic carbon nitride with porous structures, wherein the graphitic carbon nitride has at least one heptazine motif and a pore volume greater than 0.0045 cm3 / g derived from a first type of pores having a specific pore diameter of 1 nm or more and less than 15 nm and derived from a second type of pores having a specific pore diameter of 15 nm or more and 50 nm or less.

2. Graphitic carbon nitride according to claim 1, comprising at least one having a pore diameter from 1 to 500 nm, preferably from 2 to 400 nm, more preferably from 3 to 300 nm, and even more preferably from 5 to 200 nm.

3. Graphitic carbon nitride according to claim 1 or 2, having a specific surface area determined by BET process ranging from 5 to 300 m2 / g, preferably from 15 to 250 m2 / g, and more preferably from 30 to 200 m2 / g.

4. Graphitic carbon nitride according to any one of the preceding claims, having a whiteness value from -60 to 100, preferably from -40 to 80.

5. Graphitic carbon nitride according to any one of the preceding claims, having an initial absorption front value from 390 to 480 nm, preferably from 395 to 450 nm.

6. Graphitic carbon nitride according to any one of the preceding claims, having a pore volume greater than 0.0055 cm3 / g derived from pores having a specific pore diameter from 1.5 nm to 5 nm.

7. Graphitic carbon nitride according to any one of the preceding claims, having a pore volume greater than 0.0045 cm3 / g derived from pores having a specific pore diameter in the range of 20 nm to 45 nm.

8. A process for manufacturing graphitic carbon nitride according to any one of the preceding claims, comprising: i) the preparation of at least one precursor compound; and ii) heating the at least one precursor compound to 450 °C or more for at least 1 minute.

9. A method according to claim 8, wherein (ii) heating is carried out in the presence of oxygen-containing species such as O2, moisture, O3, atomic O2 and / or ionic oxygen;

10. preferably, the oxidizing agent used during the heating step being in gaseous form; more preferably, oxygen-containing species not derived from either permanganate salt or hydrogen peroxide. Use of graphitic carbon nitride according to any one of claims 1 to 7, as a paint active, as a pigment, as a filler in particular of plastics or as a cosmetic active.

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