Mxene dispersion, mxene film and method for manufacturing same, mxene composite film and method for manufacturing same, and max phase-containing material

Abstract

Provided are: a MXene dispersion having excellent MXene dispersibility in both water and an organic solvent; a MXene film using the MXene dispersion and a method for manufacturing the MXene film; a MXene composite film using the MXene dispersion and a method for manufacturing the MXene composite film; and a MAX phase-containing material. The MXene dispersion contains MXenes and a dispersion medium, wherein the extinction ratio (A2 / A1) of the maximum value A2 of extinction in the wavelength range of 300-900 nm to the minimum value A1 of extinction in the wavelength range of 300-900 nm is at least 1.15 (if there are a plurality of minimum values in the wavelength range of 300-900 nm, a minimum value on the longest wavelength side among the plurality of minimum values is selected as the minimum value A1, and if there are a plurality of maximum values in the wavelength range of 300-900 nm, a maximum value on the longest wavelength side among the plurality of maximum values is selected as the maximum value A2).

Description

MAXIN DISPERSION, MAXIN MEMBRANE AND ITS PRODUCTION METHOD, MAXIN COMPOSITE MEMBRANE AND ITS PRODUCTION METHOD, AND MAX PHASE-CONTAINING MATERIAL

[0001] The present disclosure relates to MAXIN dispersions, MAXIN membranes and methods of making same, MAXIN composite membranes and methods of making same, and MAX phase-containing materials.

[0002] Research into various inorganic compounds is actively being conducted. Among these inorganic compounds, a complex atomic layer compound called MXene has been discovered and developed in recent years as a novel material. MXene is one of the conductive two-dimensional materials, such as graphene, and exhibits high electrical conductivity and electrode activity. While MXene is expected to be applied in a variety of fields, there are various problems associated with its application.

[0003] For example, because the surface of Maxin is highly hydrophilic, it is difficult to disperse Maxin in an organic solvent. To address this issue, Patent Document 1 describes a hydrophobic organic solvent dispersion ink in which the surface of Maxin particles is modified to reduce the hydrophilic properties of the surface or to impart hydrophobic properties to the surface, and the surface-modified Maxin particles are dispersed in a hydrophobic organic solvent. The hydrophobic organic solvent dispersion ink of Patent Document 1 contains two-dimensional Maxin particles surface-modified with a functional group containing a saturated or unsaturated hydrocarbon, and an organic solvent, where the functional group is selected from the group consisting of phosphonates and amines, and the two-dimensional Maxin particles are dispersed in a hydrophobic organic solvent that forms a protective film.

[0004] However, the dispersibility of Maxin particles is insufficient in the hydrophobic organic solvent dispersion ink of Patent Document 1. Furthermore, the Maxin particles used in the hydrophobic organic solvent dispersion ink of Patent Document 1 are difficult to disperse in hydrophilic organic solvents and water. Furthermore, conventional Maxin particles other than those described in Patent Document 1, which have reduced hydrophilic properties on the surface or have been given hydrophobic properties on the surface, are dispersible in water at the research level, but do not have water dispersibility sufficient for practical use.

[0005] Patent No. 7053544

[0006] The object of the present disclosure is to provide a Maxine dispersion that has excellent dispersibility of Maxine in both water and organic solvents, a Maxine membrane using this Maxine dispersion and a method for producing the same, a Maxine composite membrane using this Maxine dispersion and a method for producing the same, and a MAX phase-containing material.

[0007] [1] A Maxine dispersion comprising Maxine and a dispersion medium, wherein the ratio (A2 / A1) of the maximum value A2 of the elimination rate in the wavelength range of 300 nm to the minimum value A1 of the elimination rate in the wavelength range of 300 nm to 900 nm is 1.15 or greater (wherein, if there are multiple minimum values ​​in the wavelength range of 300 nm to 900 nm, the minimum value with the longest wavelength among the multiple minimum values ​​is selected as minimum value A1, and if there are multiple maximum values ​​in the wavelength range of 300 nm to 900 nm, the maximum value with the longest wavelength among the multiple maxima is selected as maximum value A2). [2] The Maxine dispersion according to [1] above, wherein the solids concentration of the Maxine is 0.1% by mass or greater. [3] The Maxine dispersion according to [1] or [2] above, wherein the median diameter d50 of the Maxine is 4.0 μm or greater. [4] The Maxine dispersion according to any one of [1] to [3] above, wherein the relationship between the minimum value A1, the maximum value A2, and the extinction rate value A3 at a wavelength of 330 nm when no peak exists in the wavelength range of 300 nm to 350 nm is 0.70 or greater and 1.70 or less. [5] The Maxine dispersion according to any one of [1] to [4] above, wherein the dispersion medium is water or a hydrophilic organic solvent, and the extinction rate ratio (A2 / A1) is 1.20 or greater. [6] The Maxine dispersion according to any one of [1] to [4] above, wherein the dispersion medium is a hydrophobic organic solvent. [7] The Maxine dispersion according to any one of [1] to [6] above, wherein the dispersion medium is water, N-methyl-2-pyrrolidone, dimethylacetamide, N,N-dimethylformamide, or an alcohol. [8] The Maxine dispersion according to any one of [1] to [7] above, wherein the Maxine before being contained in the Maxine dispersion contains M, O, and F, where M is one or more transition metal elements, and where, where b is the molar ratio of O and c is the molar ratio of F, (b / c) is 0.60 to 2.30, and the half width of the diffraction peak of the (110) plane obtained by X-ray diffraction analysis is 0.60° or less. [9] The Maxine film formed from the Maxine dispersion according to any one of [1] to [8] above.

[10] The maxin membrane according to [9] above, wherein the surface of the maxin membrane is oxidized.

[11] The maxin membrane according to [9] above, wherein the surface of the maxin membrane is reduced.

[12] A method for manufacturing a maxin membrane, comprising a film-forming step of applying a solution containing the maxin dispersion according to any one of [1] to [8] above to a substrate surface to form a maxin membrane.

[13] A maxin composite membrane comprising a maxin membrane formed from the maxin dispersion according to any one of [1] to [8] above, and an organic film provided on the surface of the maxin membrane.

[14] The maxin composite membrane according to

[13] above, wherein the organic film is composed of a carboxylic acid, a sulfonic acid, a thiol, or an amine.

[15] A method for manufacturing a maxin composite membrane, comprising a first film-forming step of applying a solution containing the maxin dispersion according to any one of [1] to [8] above to a substrate surface to form a maxin membrane, and a second film-forming step of applying an organic-containing solution to the maxin membrane to form an organic film.

[16] A MAX phase-containing material comprising M, A, and X, wherein M is one or more transition metal elements, A is one or more elements selected from the group consisting of Al, Si, Ga, P, S, Ge, As, Cd, In, Sn, Tl, and Pb, and X is carbon or nitrogen, wherein a / c is 1.55 or more and 2.00 or less, and b / c is 0.55 or more and 1.00 or less, where a is the molar ratio of M, b is the molar ratio of A, and c is the molar ratio of X.

[17] The MAX phase-containing material according to

[16] above, which contains a MAX phase and a phase that dissolves in hydrofluoric acid, and the content of the phase is 1.0% or more and 50.0% or less.

[18] The MAX phase-containing material according to the above

[16] or

[17] , wherein the ratio (I1 / I2) of the intensity of the strongest diffraction peak of the phase soluble in hydrofluoric acid (I1) to the intensity of the strongest diffraction peak of the MAX phase (I2) in the XRD pattern of the MAX phase-containing material is 0.1 or more and 3.0 or less.

[0008] According to the present disclosure, it is possible to provide a maxin dispersion that has excellent dispersibility of maxin in both water and organic solvents, a maxin membrane using this maxin dispersion and a method for manufacturing the same, a maxin composite membrane using this maxin dispersion and a method for manufacturing the same, and a MAX phase-containing material.

[0009] FIG. 1 shows XRD data for the MAX phase powders of Production Examples 1 and 2. FIG. 2 shows XRD data for the MAX phase powder of Production Example 3. FIG. 3 shows XRD data for the MAX phase powder of Production Example 4. FIG. 4 shows XRD data for the MAX phase powder of Production Example 5. FIG. 5 shows XRD data for the MAX phase powder of Production Example 12. FIG. 6 shows XRD data for Maxin® of Production Example 13. FIG. 7 shows XRD data for Maxin® of Production Example 15. FIG. 8 shows XRD data for Maxin® of Production Example 16. FIG. 9 shows particle size distribution data for Maxin® of Production Example 16. FIG. 10 is an SEM image of Maxin® of Production Example 16. FIG. 11 is a graph showing the results of UV-visible absorption spectra for Maxin® dispersions of Production Examples 18 to 20. FIG. 12 is a graph showing the results of UV-visible absorption spectra for Maxin® dispersions of Production Examples 21 and 22. Figure 13 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersion of Production Example 26. Figure 14 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersion of Production Example 27. Figure 15 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersion of Production Example 33. Figure 16 is a photograph of the appearance of the Maxine dispersion of Production Example 31. Figure 17 is an SEM image of the powder obtained by drying the Maxine dispersion of Production Example 31. Figure 18 is a photograph of the appearance of the Maxine dispersion of Production Example 51. Figure 19 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersions of Production Examples 111 to 114. Figure 20 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersions of Production Examples 56 to 60. Figure 21 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersions of Production Examples 62 to 65. Figure 22 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersion of Production Example 106. Figure 23 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersions of Production Examples 107 to 109. Figure 24 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersions of Production Examples 69, 71, and 72. Figure 25 is a graph showing the results of the ultraviolet-visible absorption spectrum of the Maxine dispersions of Production Examples 115 to 119. Figure 26 is a graph showing the results of the ultraviolet-visible absorption spectrum of the diluted dispersions used in Production Examples 74 to 76. Figure 27 is a graph showing the results of the ultraviolet-visible absorption spectrum of the diluted dispersions used in Production Examples 78 to 80.Figure 28 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 73, 77, and 81. Figure 29 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 83-84 and 86. Figure 30 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 82, 85, and 87. Figure 31 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 88-89. Figure 32 is a graph showing the results of transmission spectra of the Maxine membranes of Production Examples 74-80 and 88. Figure 33 is a graph showing the results of transmission spectra of the Maxine membranes of Production Examples 83 and 86. Figure 34 is a graph showing the results of transmission spectra of the Maxine membranes of Production Examples 121-122.

[0010] Hereinafter, a detailed description will be given based on an embodiment.

[0011] As a result of extensive research, the inventors discovered that there is a correlation between the dispersibility of Maxin in Maxin dispersion and the extinction ratio (A2 / A1) of the maximum value A2 of the extinction ratio in a specified wavelength range to the minimum value A1 of the extinction ratio in a specified wavelength range of Maxin dispersion.They also found that by controlling the extinction ratio (A2 / A1) within a specified range, Maxin can be made to have excellent dispersibility regardless of whether the dispersion medium is water or an organic solvent, and have completed the present disclosure based on this finding.

[0012] The Maxine dispersion of the embodiment contains Maxine and a dispersion medium, and has an extinction ratio (A2 / A1) of the maximum extinction ratio A2 in the wavelength range of 300 nm or more and 900 nm to the minimum extinction ratio A1 in the wavelength range of 300 nm or more and 900 nm or less (however, if there are multiple minimum values ​​in the wavelength range of 300 nm or more and 900 nm or less, the minimum value on the longest wavelength side of the multiple minimum values ​​is selected as minimum value A1, and if there are multiple maximum values ​​in the wavelength range of 300 nm or more and 900 nm or less, the maximum value on the longest wavelength side of the multiple maximum values ​​is selected as maximum value A2) of 1.15 or more.

[0013] The Maxine dispersion comprises Maxine and a dispersion medium.

[0014] In the Maxine dispersion, the ratio (A2 / A1) of the maximum value A2 of the elimination rate in the wavelength range of 300 nm to 900 nm to the minimum value A1 of the elimination rate in the wavelength range of 300 nm to 900 nm is 1.15 or greater. However, if there are multiple minimum values ​​in the wavelength range of 300 nm to 900 nm, the minimum value on the longest wavelength side among the multiple minimum values ​​is selected as minimum value A1. Furthermore, if there are multiple maximum values ​​in the wavelength range of 300 nm to 900 nm, the maximum value on the longest wavelength side among the multiple maximum values ​​is selected as maximum value A2.

[0015] In general, materials become light-transmitting when their size is sufficiently smaller than the wavelength of light. Furthermore, nanometer-sized metal particles absorb light of specific wavelengths due to surface plasmon resonance. These phenomena were also observed in Maxin in a Maxin dispersion. It was found that even Maxin, which is black in its aggregated state, becomes light-transmitting and absorbs light of specific wavelengths when its thickness is sufficiently smaller than the wavelength of light. It is believed that the nanometer-sized Maxin increases its light transmittance and reduces its extinction rate over a wide wavelength range. Furthermore, the extinction rate at specific wavelengths increases due to surface plasmon resonance, resulting in the occurrence of minimum and maximum values ​​of light extinction in the wavelength range of 300 nm to 900 nm. Furthermore, it is believed that the ratio of the minimum and maximum values ​​increases as the proportion of thin-layered Maxin in a Maxin dispersion increases.

[0016] Water, organic solvents, and mixed solvents of water and organic solvents can be used as the dispersion medium for the Maxine dispersion. When dispersing Maxine in an organic solvent, adding water can improve dispersibility. The weight ratio of water is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, and even more preferably 5.0% by mass or more. From the viewpoint of solubility in resins, etc., the amount of water in the dispersion medium is preferably 10.0% by mass or less, more preferably 1.0% by mass or less, and even more preferably 0.2% by mass or less.

[0017] When the disappearance ratio (A2 / A1) of a Maxin dispersion containing Maxin and a dispersion medium is 1.15 or more, the dispersibility of Maxin is excellent, whether the dispersion medium is water or an organic solvent. Furthermore, the conductivity of the Maxin dispersion is improved, and the ability to form a conductive path is also improved. From this perspective, the disappearance ratio (A2 / A1) of the Maxin dispersion is 1.15 or more, preferably 1.20 or more, more preferably 1.30 or more, and even more preferably 1.35 or more. Furthermore, the disappearance ratio (A2 / A1) of the Maxin dispersion is, for example, 3.00 or less.

[0018] In particular, when the dispersion medium is water or a mixed solvent of water and an organic solvent containing 20 wt % or less of the organic solvent, the dispersibility of Maxin in water or the mixed solvent can be further improved by setting the elimination ratio (A2 / A1) to preferably 1.30 or more, more preferably 1.35 or more, and even more preferably 1.40 or more. When the dispersion medium is water or the mixed solvent, the elimination ratio (A2 / A1) is, for example, 2.00 or less.

[0019] When the dispersion medium is an organic solvent or a mixed solvent of water and an organic solvent containing 20 wt % or less of water, the dispersibility of Maxin in the organic solvent or the mixed solvent can be further improved by setting the elimination ratio (A2 / A1) to preferably 1.20 or more, more preferably 1.25 or more, and even more preferably 1.30 or more. When the dispersion medium is an organic solvent or the mixed solvent, the elimination ratio (A2 / A1) is, for example, 2.00 or less.

[0020] When the dispersion medium is a hydrophobic organic solvent, the dispersibility of Maxin in the hydrophobic organic solvent can be further improved by setting the elimination ratio (A2 / A1) to preferably 1.15 or more, more preferably 1.20 or more, and even more preferably 1.25 or more. When the dispersion medium is an organic solvent or the above-mentioned mixed solvent, the elimination ratio (A2 / A1) is, for example, 2.00 or less.

[0021] The extinction degree value A3 is the extinction degree value of the peak wavelength in the wavelength range of 300 nm to 350 nm, or the extinction degree value of a wavelength of 330 nm when no peak exists in the wavelength range of 300 nm to 350 nm. The peak in the wavelength range of 300 nm to 350 nm, the so-called absorption peak, also includes a shoulder peak. Furthermore, when multiple peaks exist in the wavelength range of 300 nm to 350 nm, the highest extinction degree value among the multiple peaks is used as the extinction degree value A3.

[0022] When the relationship (A1+A2) / A3 is 0.70 or more, a highly conductive Maxine film can be formed from a solution containing a Maxine dispersion. When the relationship (A1+A2) / A3 is 1.70 or less, the dispersibility of Maxine in water, organic solvents, and mixed solvents of water and organic solvents can be further improved, and a Maxine film free from aggregation can be formed during film formation.

[0023] In particular, when the dispersion medium is water or a mixed solvent of water and an organic solvent containing 20 wt% or less of the organic solvent, a highly conductive Maxine film can be formed when the relationship (A1+A2) / A3 is preferably 0.80 or more, more preferably 0.85 or more, and even more preferably 0.90 or more. Furthermore, when the relationship (A1+A2) / A3 is preferably 1.50 or less, more preferably 1.20 or less, and even more preferably 1.00 or less, the dispersibility of Maxine in the dispersion medium can be further improved, and a Maxine film that does not aggregate during film formation can be formed.

[0024] Furthermore, when the dispersion medium is an organic solvent or a mixed solvent of water and an organic solvent containing 20 wt % or less of water, a highly conductive Maxine film can be formed when the relationship (A1+A2) / A3 is preferably 0.90 or more, more preferably 1.00 or more, and even more preferably 1.20 or more. Furthermore, when the relationship (A1+A2) / A3 is preferably 1.60 or less, more preferably 1.50 or less, and even more preferably 1.30 or less, the dispersibility of Maxine in the dispersion medium can be further improved, and a Maxine film that does not aggregate during film formation can be formed.

[0025] In the MAXIN dispersion, the greater the wavelength at which the maximum value A2 of the extinction rate in the wavelength range of 300 nm to 900 nm is, the more conductive the MAXIN film that can be formed. ３ C ２ In this case, the wavelength is preferably 800 nm or more, more preferably 815 nm or more, and even more preferably 840 nm or more.

[0026] The disappearance rate of Maxine dispersion is measured by absorptiometry. The Maxine dispersion is diluted with a dispersing medium to prepare a sample with a concentration that falls within the measurement range of the measuring instrument (generally, a disappearance rate of 2 or less is recommended). This sample is measured with a spectrophotometer, and the disappearance rate can be calculated from the disappearance spectrum. Here, the disappearance rate A is calculated as follows: A = -log(I0, I) １０ It is defined as (I / I0). The extinction ratio includes the light absorbing component and the light scattering component of the dispersion.

[0027] Furthermore, the Maxine dispersion may contain various additives in addition to Maxine and the dispersion medium, provided that the dispersibility of Maxine is not reduced.

[0028] The maxine contained in the maxine dispersion is either multilayer maxine (multilayer MXene), in which many sheet-like crystals are stacked to form particles with a thickness exceeding 1 μm, or delaminated maxine (delaminated MXene), in which the multilayer maxine is exfoliated to form single to several tens of layers of crystals. Exfoliated maxine is particularly preferred due to its high dispersibility. The maxine in the maxine dispersion having such a structure differs from the maxine used as a raw material for the maxine in the maxine dispersion in terms of crystal structure and elemental composition. The maxine used as a raw material for the maxine in the maxine dispersion, i.e., the maxine before being contained in the maxine dispersion, contains M, O (oxygen), and F (fluorine), where M is one or more transition metal elements, and where the molar ratio of O is b and the molar ratio of F is c, the ratio (b / c) is 0.60 or more and 2.30 or less, and the half-width of the diffraction peak of the (110) plane obtained by X-ray diffraction analysis is preferably 0.60° or less.

[0029] MAXIN with this configuration has excellent heat resistance, and therefore, products such as MAXIN films formed from MAXIN dispersions prepared from MAXIN with this configuration have excellent heat resistance and are therefore suitable for use in, for example, electronic components and storage battery components, solar cells, LEDs, touch panel components, and other components that are manufactured and used in high-temperature environments.

[0030] M constituting maxine is one or more transition metal elements, preferably early transition metal elements. For example, M may be one transition metal element or two or more transition metal elements.

[0031] Furthermore, Maxine may further contain X in addition to M, O, and F. X is one or more elements selected from C (carbon) and N (nitrogen). That is, X is either C only, N only, or C and N.

[0032] When Maxine contains M, O, F, and X, from the viewpoint of improving the heat resistance of Maxine, M is preferably at least one of Group 4 and Group 5 elements of the periodic table, more preferably at least one of Ti (titanium) and Nb (niobium). From the same viewpoint, X is preferably C.

[0033] In addition to M, O, and F, Maxine may further include X and Y. Y is one or more elements selected from the group consisting of H (hydrogen), alkali metal elements, alkaline earth metal elements, chalcogen elements excluding oxygen, and halogen elements excluding fluorine. For example, Y may be one alkali metal element, or one alkali metal element and one alkaline earth metal element. Y is preferably one or more elements selected from the group consisting of H, Li, Na, K, Be, Mg, Ca, Sr, Ba, Ra, S, Se, Te, Cl, Br, and I, more preferably one or more elements selected from the group consisting of H, Li, Na, K, Mg, Ca, S, Se, Cl, and Br, and even more preferably one or more elements selected from the group consisting of H, Li, Na, and Cl.

[0034] When Maxine contains M, O, F, X, and Y, from the viewpoint of improving the heat resistance of Maxine, M is preferably at least one of Group 4 and Group 5 elements of the periodic table, more preferably at least one of Ti and Nb. From the same viewpoint, X is preferably C.

[0035] Furthermore, Maxine may contain one or more elements selected from the group consisting of Al, Si, Ga, P, S, Ge, As, Cd, In, Sn, Tl, and Pb as inevitable impurities. Inevitable impurities are impurities that are inevitably mixed in during the manufacturing process. Since the content of inevitable impurities can affect the properties of Maxine, it is preferable that the content of inevitable impurities is low.

[0036] From the viewpoint of maintaining the improved heat resistance of Maxine, the ratio of the total molar amount Wi of unavoidable impurities to the total molar amount Wm of M contained in Maxine (Wi / Wm) is 5.0 × 10 －１ The lower limit of the ratio (Wi / Wm) is, for example, 1.0×10 －６ That's all.

[0037] Furthermore, Maxine may contain elements other than the above elements to the extent that the effect of improving the heat resistance of Maxine is not reduced.

[0038] When maxine contains M, O, F, and X, maxine is expressed by the following formula (1), where a is the molar ratio of M contained in maxine, b is the molar ratio of O, c is the molar ratio of F, and d is the molar ratio of X. When X consists of C and N, the molar ratio of C is expressed as d1 and the molar ratio of N is expressed as d2. The sum of d1 and d2 (d1 + d2) is d.

[0039] M ａ X ｄ O ｂ F ｃ Formula (1)

[0040] As the maxin expressed by the formula (1), Ti ａ C ｄ O ｂ F ｃ , Ti ａ N ｄ Oｂ F ｃ 、Tru ａ C ｄ１ N ｄ２ O ｂ F ｃ ,V ａ C ｄ O ｂ F ｃ ,V ａ N ｄ O ｂ F ｃ ,V ａ C ｄ１ N ｄ２ O ｂ F ｃ 、Nb ａ C ｄ O ｂ F ｃ 、Nb ａ N ｄ O ｂ F ｃ 、Nb ａ C ｄ１ N ｄ２ O ｂ F ｃ ,Mo ａ C ｄ O ｂ F ｃ ,Mo ａ N ｄ O ｂ F ｃ ,Mo ａ C ｄ１ N ｄ２ O ｂ F ｃ ,Sc ａ C ｄ O ｂ F ｃ ,Sc ａ N ｄ O ｂ F ｃ ,Sc ａ C ｄ１ N ｄ２ O ｂ F ｃ ,Cr ａ C ｄ O ｂ F ｃ ,Cr ａ N ｄ O ｂ F ｃ ,Cr ａ C ｄ１ Nｄ２ O ｂ F ｃ , Zr ａ C ｄ O ｂ F ｃ , Zr ａ N ｄ O ｂ F ｃ , Zr ａ C ｄ１ N ｄ２ O ｂ F ｃ , Hf ａ C ｄ O ｂ F ｃ , Hf ａ N ｄ O ｂ F ｃ , Hf ａ C ｄ１ N ｄ２ O ｂ F ｃ , Ta ａ C ｄ O ｂ F ｃ , Ta ａ N ｄ O ｂ F ｃ , Ta ａ C ｄ１ N ｄ２ O ｂ F ｃ is preferable in terms of improving heat resistance and ease of synthesis, and among them, Ti ａ C ｄ O ｂ F ｃ , Ti ａ N ｄ O ｂ F ｃ , Ti ａ C ｄ１ N ｄ２ O ｂ F ｃ , V ａ C ｄ O ｂ F ｃ , V ａ N ｄ O ｂ F ｃ , V ａ C ｄ１ N ｄ２ O ｂ F ｃ, Nb ａ C ｄ O ｂ F ｃ , Nb ａ N ｄ O ｂ F ｃ , Nb ａ C ｄ１ N ｄ２ O ｂ F ｃ , Mo ａ C ｄ O ｂ F ｃ , Mo ａ N ｄ O ｂ F ｃ , Mo ａ C ｄ１ N ｄ２ O ｂ F ｃ , Cr ａ C ｄ O ｂ F ｃ , Cr ａ N ｄ O ｂ F ｃ , Cr ａ C ｄ１ N ｄ２ O ｂ F ｃ , Ta ａ C ｄ O ｂ F ｃ , Ta ａ N ｄ O ｂ F ｃ , Ta ａ C ｄ１ N ｄ２ O ｂ F ｃ is more preferable in that it has high electrical conductivity, catalytic function, etc., and among them, Ti ａ C ｄ１ N ｄ２ O ｂ F ｃ , V ａ C ｄ O ｂ F ｃ , V ａ N ｄ O ｂ F ｃ , V ａ C ｄ１N ｄ２ O ｂ F ｃ , Nb ａ C ｄ O ｂ F ｃ , Nb ａ N ｄ O ｂ F ｃ , Nb ａ C ｄ１ N ｄ２ O ｂ F ｃ is more preferable in that the above-mentioned functions are further improved.

[0041] Furthermore, when maxine contains M, O, F, X, and Y, maxine is expressed by the following formula (2), where a is the molar ratio of M contained in maxine, b is the molar ratio of O, c is the molar ratio of F, d is the molar ratio of X, and e is the molar ratio of Y. When Y consists of n elements Y1 to Yn (n is an integer of 1 or more), the molar ratios of each element in Y are expressed as e1 to en, respectively. The sum of e1 to en (e1 + ... + en) is e.

[0042] M ａ X ｄ O ｂ F ｃ Y ｅ Formula (2)

[0043] From the viewpoint of improving the heat resistance of Maxine, in Maxine represented by formula (2), Y preferably contains one or more elements selected from the group consisting of H, Li, Na, K, Be, Mg, Ca, Sr, Ba, Ra, S, Se, Te, Cl, Br and I, more preferably contains one or more elements selected from the group consisting of H, Li, Na, K, Mg, Ca, S, Se, Cl and Br, and even more preferably contains one or more elements selected from the group consisting of H, Li, Na and Cl. Specific examples of Maxine represented by formula (2) include Ti, ａ C ｄ O ｂ F ｃ H ｅ , Ti ａ N ｄ O ｂ F ｃ H ｅ , Ti ａ Cｄ１ N ｄ２ O ｂ F ｃ H ｅ , Ti ａ C ｄ O ｂ F ｃ H ｅ１ Li ｅ２ , Ti ａ N ｄ O ｂ F ｃ H ｅ１ Li ｅ２ , Ti ａ C ｄ１ N ｄ２ O ｂ F ｃ H ｅ１ Li ｅ２ , Ti ａ C ｄ O ｂ F ｃ H ｅ１ Cl ｅ２ , Ti ａ N ｄ O ｂ F ｃ H ｅ１ Cl ｅ２ , Ti ａ C ｄ１ N ｄ２ O ｂ F ｃ H ｅ１ Cl ｅ２ , Nb ａ C ｄ O ｂ F ｃ H ｅ is preferred.

[0044] When the molar ratio of O contained in MAXYN is b and the molar ratio of F is c, it is preferable that (b / c) is 0.60 or more and 2.30 or less. When (b / c) is within the above range, the heat resistance of MAXYN can be improved.

[0045] Furthermore, when the molar ratio of M contained in Maxine is a, it is preferable that ((b+c) / a) is 1.60 or less. When ((b+c) / a) is within the above range, the heat resistance of Maxine can be further improved.

[0046] In particular, from the viewpoint of improving the heat resistance of Maxine at temperatures from room temperature to 350°C, (b / c) is preferably 0.60 or more, more preferably 1.10 or more, even more preferably 1.30 or more, and particularly preferably 1.70 or more. From the same viewpoint, the upper limit of ((b+c) / a) is preferably 1.60 or less, more preferably 1.20 or less, and even more preferably 1.00 or less, and the lower limit of ((b+c) / a) is preferably 0.30 or more, more preferably 0.70 or more. Furthermore, from the viewpoint of improving the heat resistance of Maxine at temperatures of 350°C or higher, (b / c) is preferably 2.30 or less, more preferably 2.10 or less, even more preferably 1.80 or less, and particularly preferably 1.40 or less. From the same viewpoint, the upper limit value of ((b+c) / a) is preferably 1.60 or less, and the lower limit value of ((b+c) / a) is preferably 0.30 or more, more preferably 0.70 or more, even more preferably 1.00 or more, and particularly preferably 1.20 or more.

[0047] The weight loss of Maxin from room temperature to 350°C is thought to be mainly due to the decomposition and volatilization of weakly bonded surface functional group atoms present on the Maxin surface. The smaller the ((b + c) / a), which represents the total amount of functional groups, the higher the heat resistance of Maxin. The larger the (b / c), which represents the ratio of functional group species, the lower the amount of M-F bonds, which are relatively weak bonds, and the better the heat resistance of Maxin. Furthermore, the weight loss of Maxin at temperatures above 350°C is thought to be due to the decomposition of strongly bonded surface functional groups and the decomposition of the bulk portion of Maxin. The fewer defects and strains in Maxin, the higher the heat resistance of Maxin. If (b / c) and ((b + c) / a) are within the above ranges, Maxin with fewer defects and strains can be obtained, thereby improving the heat resistance of Maxin.

[0048] The molar ratio a of M, the molar ratio b of O, and the molar ratio c of F contained in Maxine can be measured by SEM-EDX.

[0049] Furthermore, the half-width (hereinafter simply referred to as the half-width) of the diffraction peak of the (110) plane obtained by X-ray diffraction analysis of Maxin is preferably 0.60° or less, more preferably 0.54° or less, and even more preferably 0.40° or less; the smaller the half-width, the better. When the half-width is 0.60° or less, the heat resistance of Maxin can be improved, and the smaller the half-width, the better the heat resistance of Maxin. Decomposition of Maxin is thought to occur from defects and strained portions of the crystal, and it is thought that when the half-width is small, i.e., when the single crystal size is large and there are few defects, Maxin is less likely to decompose and has higher heat resistance. The lower limit of the half-width is, for example, 0.001° or more.

[0050] X-ray diffraction analysis of Maxine is performed as follows. Using an X-ray diffractometer, powdered Maxine is filled into a sample holder, and the X-ray diffraction intensity is measured between 3° and 80° using the θ-2θ method. The background noise value is subtracted from the peak intensity to obtain the diffraction peak of the (110) plane. The half-width is calculated based on the obtained diffraction peak of the (110) plane. In this case, characteristic X-rays of CuKα (wavelength 0.154 nm) are used as the X-rays.

[0051] Furthermore, the lower limit of the thickness of the Maxin layer having the above configuration is preferably 0.15 μm or more, more preferably 0.18 μm or more, and even more preferably 0.20 μm or more, and the upper limit is preferably 10.00 μm or less, more preferably 5.00 μm or less, and even more preferably 2.00 μm or less. When the Maxin layer thickness is 0.15 μm or more, the heat resistance of the Maxin is improved. When the Maxin layer thickness is 10.00 μm or less, the Maxin layer can be in a sheet form, and effects such as an increased specific surface area can be obtained.

[0052] The thickness of the Maxin layer is not the thickness of a Maxin single crystal sheet (single crystal in sheet form), but the thickness of a sheet-like aggregate formed by stacking multiple Maxin single crystal sheets with gaps of approximately 0.05 μm or less. The shape of Maxin and the thickness of the Maxin layer were measured by observing powdered Maxin with a scanning electron microscope (SEM).

[0053] Furthermore, when Maxine contains hydrogen fluoride (HF), the weight ratio of HF in Maxine to the total amount of Maxine (hereinafter simply referred to as the HF weight ratio) is preferably 50 ppm or less, more preferably 20 ppm or less, and even more preferably 10 ppm or less, with the smaller the ratio the better. An HF weight ratio of 50 ppm or less can further improve the heat resistance of Maxine, and the smaller the HF weight ratio, the more the heat resistance of Maxine can be improved. The lower limit of the HF weight ratio is, for example, 1 ppt or more.

[0054] The weight ratio of HF can be determined by mixing Maxine with an organic solvent that dissolves HF, stirring for 24 hours, measuring the F ion concentration in the organic solvent using ion chromatography to quantify the weight of HF extracted into the organic solvent, and dividing the weight of HF by the weight of Maxine.

[0055] Furthermore, when Maxine contains moisture, the weight ratio of moisture in Maxine to the total amount of Maxine (hereinafter simply referred to as the moisture weight ratio) is preferably 1.0% or less, more preferably 0.5% or less, and even more preferably 0.1% or less, with the smaller the ratio the better. A moisture weight ratio of 1.0% or less can further improve the heat resistance of Maxine, and the smaller the moisture weight ratio, the more the heat resistance of Maxine can be improved. The lower limit of the moisture weight ratio is, for example, 1 ppm or more.

[0056] The weight ratio of water can be determined by mixing Maxine with a water-miscible organic solvent, stirring for 24 hours, quantifying the amount of water in the organic solvent using a Karl Fischer moisture meter, etc., and dividing the weight of water by the weight of Maxine.

[0057] The maxine having the above-described structure, which is the raw material for the maxine contained in the maxine dispersion, can be produced as follows.

[0058] For example, a MAX phase is added to a solution (hereinafter also referred to as a removal solution) that selectively removes the A phase from the MAX phase, thereby producing nano-sized single crystal sheets composed mainly of M and X, and aggregates consisting of stacks of multiple single crystal sheets. The aggregates produced in the solution are then washed and dried to obtain powdered aggregates. This process itself is a common method for producing conventional MAXIN. Here, A is an element in Group 13 or 14 of the periodic table. The removal solution is preferably hydrofluoric acid (hydrofluoric acid), which is an aqueous solution of hydrogen fluoride (HF). Alternatively, the removal solution may be a mixed solution of hydrofluoric acid and other acids (e.g., hydrochloric acid, sulfuric acid, nitric acid, organic acid, etc.).

[0059] In this process, the A phase is selectively removed, and the surface of the single crystal sheet is modified to introduce functional groups such as -OH, -O, and -F as terminal groups on the surface. However, in such conventional processes, no reaction control of the functional groups, such as the amount of the functional groups introduced onto the surface of the single crystal sheet, is performed, and in some cases, the idea of ​​controlling the reaction of the functional groups has not even been considered.

[0060] On the other hand, in the above process, the composition and crystallite size of Maxine can be controlled to improve its heat resistance by changing the amount of MAX phase added to the removal solution, the conditions for removing phase A in the removal solution, the washing conditions, the drying conditions, etc. Furthermore, by changing the amount of MAX phase added to the removal solution and the above conditions, the type and amount of inevitable impurities in Maxine, the shape of Maxine, the amount of HF and water in Maxine, etc. can be controlled, thereby improving the heat resistance of Maxine.

[0061] For example, in controlling the composition of Maxine, increasing the concentration or equivalent of hydrofluoric acid contained in the removal solution can reduce (b / c). Also, extending the reaction time (removal time) can increase (b / c) and reduce ((b+c) / a).

[0062] Furthermore, maxine containing M, O, F, X, and Y can be produced by using a solution containing Y as the removal solution. For example, if an acidic aqueous solution is used as the removal solution, H or the like can be introduced as Y, and if an aqueous solution containing hydrochloric acid is used, H and Cl can be introduced as Y.

[0063] In addition, the crystallite size can be controlled by lowering the reaction temperature and lengthening the reaction time, thereby reducing the half-width of the diffraction peak of the (110) plane obtained by X-ray diffraction analysis of Maxine.

[0064] The type of unavoidable impurities can be changed depending on the composition of the MAX phase used as the raw material. For example, Ti ３ C ２ Al and Nb ２ If CAl is used, Al becomes an inevitable impurity, and Ti ３ C ２ If Si is used, Si becomes an inevitable impurity. The amount of inevitable impurities can be controlled by, for example, the concentration of hydrofluoric acid or the number of cleaning cycles. For example, the amount of inevitable impurities can be increased by using a removal solution with a high concentration of hydrofluoric acid, and can be decreased by increasing the number of cleaning cycles.

[0065] In addition, to control the shape of maxine, increasing the concentration of hydrofluoric acid in the removal solution from a few percent to about 50% can reduce the thickness of the maxine aggregates, i.e., the thickness of the maxine layer. Also, increasing the temperature of the removal solution can reduce the thickness of the maxine layer.

[0066] The amount of HF in Maxine can be controlled by the number of times of washing and the washing method. For example, the amount of HF can be reduced by increasing the number of times of washing.

[0067] The moisture content of Maxine can be controlled by the drying temperature and pressure. For example, increasing the drying temperature can reduce the moisture content.

[0068] The dispersion medium contained in the Maxine dispersion is preferably water, N-methyl-2-pyrrolidone (NMP), dimethylacetamide (DMAC), N,N-dimethylformamide (DMF), or alcohol.

[0069] Furthermore, the solids concentration of Maxin in the Maxin dispersion is preferably 0.1% by mass or more, more preferably 0.7% by mass or more, and even more preferably 3.0% by mass or more, to obtain a Maxin dispersion with excellent Maxin dispersibility and a high Maxin concentration. Such a high-concentration and highly dispersible Maxin dispersion can be used in a variety of applications, and is suitable for coating applications. Furthermore, a Maxin solids concentration of 0.7% by mass or more is suitable as a conductive additive for lithium-ion batteries, and a Maxin solids concentration of 3.0% by mass or more can produce a slurry with high solids concentration and viscosity when mixed with a resin or the like. Furthermore, to maintain high Maxin dispersibility, the solids concentration of Maxin is, for example, 30.0% by mass or less, preferably 20.0% by mass or less, and more preferably 10.0% by mass or less.

[0070] Furthermore, the Maxine dispersion preferably contains water as the dispersion medium and at least one of alkylammonium salts, alkali metal salts, and alkaline earth metal salts at a concentration of 0.001% by mass or more but less than 2.000% by mass. It is particularly preferable to contain at least one of alkylammonium salts or alkali metal salts, and more preferably alkylammonium salts. When the concentration of at least one of alkylammonium salts, alkali metal salts, and alkaline earth metal salts is 0.001% by mass or more, the dispersibility of Maxine is further improved and aggregation of Maxine during exposure to the atmosphere can be suppressed. The concentration of at least one of alkylammonium salts, alkali metal salts, and alkaline earth metal salts is more preferably 0.010% by mass or more, and even more preferably 0.040% by mass or more. When the concentration of at least one of alkylammonium salts, alkali metal salts, and alkaline earth metal salts is less than 2.000% by mass, the reduction in smoothness of the Maxine film obtained by applying the Maxine dispersion, which is caused by the precipitation of the salts in the Maxine film, can be suppressed. The concentration of any one or more of alkylammonium salts, alkali metal salts, and alkaline earth metal salts is more preferably 1.000% by mass or less, and even more preferably 0.700% by mass or less.

[0071] Furthermore, it is preferable that the dispersion medium of the Maxin dispersion is water, and that it contains at least one of alkylammonium salts, alkali metal salts, and alkaline earth metal salts in an amount of 0.003% by mass or more but less than 500.0% by mass relative to Maxin. It is particularly preferable that it contains at least one of alkylammonium salts or alkali metal salts, and it is more preferable that it contains alkylammonium salts. When at least one of alkylammonium salts, alkali metal salts, and alkaline earth metal salts is at least 0.003% by mass relative to Maxin, the dispersibility of Maxin is further improved and aggregation upon exposure to the atmosphere can be suppressed. The mass ratio of at least one of alkylammonium salts, alkali metal salts, and alkaline earth metal salts to Maxin is more preferably 1.0% by mass or more, and even more preferably 5.0% by mass or more. When at least one of alkylammonium salts, alkali metal salts, and alkaline earth metal salts is less than 500.0% by mass relative to Maxin, it is possible to suppress a decrease in the smoothness of the Maxin film obtained by applying the Maxin dispersion, which is caused by the precipitation of salts in the Maxin film. The mass ratio of any one or more of alkylammonium salts, alkali metal salts and alkaline earth metal salts to Maxine is more preferably 50.0 mass % or less, and even more preferably 20.0 mass % or less.

[0072] As the alkylammonium salt, it is preferable to use a molecule represented by the following formula (3).

[0073]

[0074] In the above formula (3), R １ , R ２ , R ３ , R ４are each independently hydrogen, halogen, an alkyl group (preferably a methyl group, an isopropyl group, or a tertiary butyl group), an aryl group (preferably a phenyl group, a naphthyl group, or a thienyl group), a haloaryl group (preferably a pentafluorophenyl group, a 3-fluorophenyl group, or a 3,4,5-trifluorophenyl group), an alkenyl group, an alkynyl group, an amido group, an acyl group, an alkoxy group (preferably a methoxy group), an aryloxy group (preferably a phenoxy group or a naphthyl group), a haloalkyl group (preferably a perfluoroalkyl group), a thiocyano group, a hydroxyl group, an amino group, a thiol group, a phosphonic acid group, a phosphonate ester group, a functional group having a succinimide skeleton, a functional group having a pyrrolidone skeleton, a selenol group, a polysulfide group, a polyselenide group, a carboxylic acid group, a functional group having an acid anhydride skeleton, a sulfonic acid group, a nitro group, a cyano group, or a structure combining these. ｎ－ Examples of the alkyl ammonium salt include halide ions, hydroxide ions, nitrate ions, acetate ions, oxide ions, sulfide ions, sulfate ions, carbonate ions, and phosphate ions. Of these, preferred alkyl ammonium salts are tetramethylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide.

[0075] Furthermore, a Maxine dispersion in which the dispersion medium is water and which contains a water-soluble basic solvent in an amount equal to or less than the Maxine content can improve coatability in the atmosphere and also improve oxidation stability.

[0076] The median diameter d50 of the maxin contained in the maxin dispersion is preferably 4.0 μm or more, more preferably 5.0 μm or more, and even more preferably 10.0 μm or more. The median diameter d50 of the maxin is measured by measuring the maxin dispersion using a laser diffraction particle size distribution analyzer. Because the maxin is in a sheet shape, the ratio of the sheet's planar size to its thickness (aspect ratio) is large. Therefore, the median diameter d50 obtained using the particle size distribution analyzer essentially corresponds to the size of the maxin sheet, and the thickness of the maxin sheet is much smaller than the median diameter d50. In other words, the larger the median diameter d50, the larger the aspect ratio of the maxin. Therefore, when the median diameter d50 of the maxin contained in the maxin dispersion is 4.0 μm or more, an increase in the viscosity of the maxin dispersion can be suppressed, and the conductivity and oxidation resistance of the maxin can be improved. In addition, in order to suppress sedimentation of the maxine, the median diameter d50 of the maxine is preferably 100.0 μm or less, more preferably 50.0 μm or less, and even more preferably 30.0 μm or less.

[0077] The maxine contained in the maxine dispersion may also be modified with an organic substance.

[0078] The organic substance modifying the surface of Maxin in the Maxin dispersion has one or more bonding groups, and the bonding groups are preferably one or more groups selected from the group consisting of amino groups, alkylamino groups, dialkylamino groups, carboxy groups, functional groups having an acid anhydride skeleton, sulfo groups, phosphonic acid groups, phosphate groups, phosphate ester groups, thiol groups, selenol groups, polysulfide groups, polyselenide groups, phenol groups, functional groups having a succinimide skeleton, functional groups having a pyrrolidone skeleton, nitro groups, and cyano groups. The bonding groups are preferably acidic functional groups, more preferably one or more groups selected from the group consisting of carboxy groups, functional groups having an acid anhydride skeleton, sulfo groups, phosphonic acid groups, phosphate groups, thiol groups, selenol groups, polysulfide groups, polyselenide groups, and phenol groups, and even more preferably one or more groups selected from the group consisting of carboxy groups and sulfo groups. From the viewpoint of dispersibility, the bonding groups are preferably phosphate ester groups.

[0079] The organic substance that modifies the surface of maxin in the maxin dispersion may be either a low molecular weight or a high molecular weight.

[0080] Examples of polymer structures include polyethylene glycol (PEG), polypropylene glycol (PPG), polyimide, polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polyester, polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacetal, polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyetherketone (PEK), polyphthalamide (PPA), polyethernitrile (PEN), polybenzimidazole (PBI), polycarbodiimide, polysiloxane, polymethacrylamide, nitrile rubber, and acrylic rubber. , polyethylene tetrafluoride, epoxy resin, phenolic resin, melamine resin, urea resin, polymethyl methacrylate resin (PMMA), acrylic resin, polybutene, polypentene, ethylene-propylene copolymer, ethylene-butene-diene copolymer, polybutadiene, polyisoprene, ethylene-propylene-diene copolymer, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymer, polyethylene (PE), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polyether ether ketone (PEEK), phenol novolak, benzocyclobutene, polyvinylphenol, polychloroprene, polyoxymethylene, polysulfone (PSF), polysulfide, polysiloxane, polysaccharide, and carboxymethyl cellulose are preferred. In particular, dispersants having a skeleton selected from a polyethylene glycol skeleton, a polypropylene glycol skeleton, a polyacetal skeleton, a polybutene skeleton, and a polysulfide skeleton are even more preferred because they are easily decomposed and can be easily removed by heating.

[0081] Preferred examples of low molecules include alkanes, alkenes, alkynes, aromatic and perfluoroalkanes having a bonding group, molecules having an amide bond, molecules having an ester bond, molecules having an oxyethylene skeleton, molecules having a heterocyclic skeleton, organometallic complexes, and molecules having an alicyclic skeleton. From the viewpoint of electrical conductivity, molecules having 10 or less carbon atoms are preferred, and from the viewpoint of dispersibility in organic solvents, molecules having an aromatic skeleton are preferred. Specific examples of low-molecular-weight compounds include formic acid, acetic acid, propionic acid, butyric acid, decanoic acid, dodecanoic acid, lauric acid, benzoic acid, phenylacetic acid, 3-phenylpropionic acid, methoxyacetic acid, ethoxyacetic acid, methoxypropionic acid, ethoxypropionic acid, perfluorooctanoic acid, perfluorobutyric acid, ethylamine, propylamine, decylamine, diethylamine, pyridine, aniline, benzylamine, phenylethylamine, methoxyethylamine, methoxypropylamine, anisidine, pyrrole, pyrrolidone, imidazole, piperazine, heptafluorobutylamine, aminoethanethiol, mercaptobenzimidazole, 1,3-propanediamine, and aminoethoxyethanol. Maxine modified with benzoic acid, phenylacetic acid, 3-phenylpropionic acid, aniline, benzylamine, or phenylethylamine is particularly preferred due to its excellent dispersibility in organic solvents.

[0082] Furthermore, from the viewpoints of improving the dispersibility of Maxin when the dispersion medium is a hydrophobic organic solvent and facilitating solvent replacement during the production of Maxin dispersions (described later), it is preferable that the organic substance modifying the surface of Maxin in Maxin dispersions has a linear structure, a bonding group at one end, and an aromatic structure at the other end. The bonding group is preferably an amino group or a carboxy group. Carboxy groups have high oxidation resistance, and thus Maxin surface-modified with carboxy groups can be used for long periods in an oxidizing atmosphere, making them more preferable.

[0083] Furthermore, when the dispersion medium is water, from the viewpoint of improving the dispersibility of Maxin, the organic substance that modifies the surface of Maxin is preferably a molecule that is miscible with water, and among these, a molecule having 10 or less carbon atoms is more preferable in terms of excellent conductivity. Specifically, methoxypropylamine, aminoethoxyethanol, methoxyacetic acid, glycolic acid, and lactic acid can be preferably used.

[0084] Furthermore, when the dispersion medium is NMP, from the viewpoint of improving the dispersibility of Maxin, it is preferable that the Maxin dispersion further contains an additive having an acid value of 50 mgKOH / g or more or an additive having an amine value of 50 mgKOH / g or more. The acid value of the additive is more preferably 80 mgKOH / g or more, and even more preferably 100 mgKOH / g or more. The acid value of the additive is, for example, 400 mgKOH / g or less.

[0085] In order to improve the dispersibility of maxin in the maxin dispersion, the maxin dispersion preferably further contains a polysaccharide, preferably gum arabic.

[0086] In order to improve the redispersibility of Maxine in the Maxine dispersion, the Li concentration of the Maxine dispersion is preferably 0.01% or more. The Li concentration can be controlled by adding lithium chloride or lithium hydroxide to Maxine.

[0087] Furthermore, if the carbonate ion concentration of the maxin dispersion is 1.0% or less, the aggregation of maxin can be further suppressed and the dispersibility of maxin can be further improved.

[0088] The MAXIN dispersion of this embodiment may contain a surface energy adjuster to improve coatability, which improves the smoothness of the resulting coating film and results in a more uniform conductive MAXIN film.

[0089] Specific examples of the surface energy adjuster include, by trade name, Triton (registered trademark) X-45, Triton (registered trademark) X-100, Triton (registered trademark) X, Triton (registered trademark) A-20, Triton (registered trademark) X-15, Triton (registered trademark) X-114, Triton (registered trademark) X-405, Tween (registered trademark) #20, Tween (registered trademark) #40, Tween (registered trademark) #60, Tween (registered trademark) #80, Tween (registered trademark) #85, Pluronic (registered trademark) F-68, Pluronic (registered trademark) F-127, Span (registered trademark) 20, Span (registered trademark) 40, Span (registered trademark) 60, Span (registered trademark) 80, and Span (registered trademark) 83, Span (registered trademark) 85, etc.; "Surflon (registered trademark) S-211," "Surflon (registered trademark) S-221," "Surflon (registered trademark) S-231," "Surflon (registered trademark) S-232," "Surflon (registered trademark) S-233," "Surflon (registered trademark) S-242," "Surflon (registered trademark) S-243," "Surflon (registered trademark) S-611," etc., manufactured by AGC Seimi Chemical; "Novec (registered trademark) FC-4430," "Novec (registered trademark) FC-4432," etc., manufactured by 3M; "Megafac F-444," "Megafac F-558," etc., manufactured by DIC are preferred. These may be used alone or in combination.

[0090] The amount of surface energy adjuster added to the Maxine dispersion of this embodiment is preferably 0.010% by mass or more, more preferably 0.100% by mass or more, based on the total amount of the Maxine dispersion. Furthermore, the amount of surface energy adjuster added is preferably 2.000% by mass or less, more preferably 1.500% by mass or less, based on the total amount of the Maxine dispersion. When the surface energy adjuster is contained in an amount of 0.010% by mass or more, the thickness of the resulting coating film tends to be uniform when the Maxine dispersion is applied, and coating unevenness tends to be less likely to occur. On the other hand, in order to ensure good conductivity in the Maxine film obtained by application, it is preferable that the amount of surface energy adjuster added be 2.000% by mass or less.

[0091] The Maxine dispersion of this embodiment may contain a binder resin to adjust viscosity, improve coating properties, improve adhesion to the substrate, etc. Examples of the binder resin include polyethylene glycol (PEG), polypropylene glycol (PPG), polyimide, polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polyester, polycarbonate (PC), polyvinyl alcohol (PVA), polyvinyl butyral (PVB), polyacetal, polyarylate (PAR), polyamide (PA), polyamideimide (PAI), polyetherimide (PEI), polyphenylene ether (PPE), polyphenylene sulfide (PPS), polyetherketone (PEK), polyphthalamide (PPA), polyethernitrile (PEN), polybenzimidazole (PBI), polycarbodiimide, polysiloxane, polymethacrylamide, nitrile rubber, acrylic rubber, Preferred examples include polyethylene tetrafluoride, epoxy resins, phenolic resins, melamine resins, urea resins, polymethyl methacrylate resins (PMMA), acrylic resins, polybutene, polypentene, ethylene-propylene copolymers, ethylene-butene-diene copolymers, polybutadiene, polyisoprene, ethylene-propylene-diene copolymers, butyl rubber, polymethylpentene (PMP), polystyrene (PS), styrene-butadiene copolymers, polyethylene (PE), polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF), polyether ether ketone (PEEK), phenol novolak, benzocyclobutene, polyvinylphenol, polychloroprene, polyoxymethylene, polysulfone (PSF), polysulfides, polysiloxanes, polysaccharides, and carboxymethyl cellulose.

[0092] The MAXIN dispersion of this embodiment may contain a conductive material other than MAXIN to improve conductivity. The conductive material is preferably metal fine particles, metal nanoplates, metal nanowires, metal oxide particles, carbon-based materials (preferably graphite, carbon black, single-walled carbon nanotubes, multi-walled carbon nanotubes, carbon fiber, graphene, or graphene oxide), or an organic conductive material (preferably PEDOT / PSS, polyaniline, polypyrrole, or polythiophene).

[0093] In one example of a method for producing a maxin dispersion of an embodiment, the maxin obtained by etching the MAX phase with hydrofluoric acid at a concentration of 1% to 50% (the maxin used as the raw material for the maxin in the maxin dispersion described above) is immersed in an aqueous solution containing one or more of an alkylammonium salt, an alkali metal salt, or an alkaline earth metal salt as a release agent to thin the maxin and obtain a maxin dispersion. Another example is dispersing multilayer maxin or exfoliated maxin in a mixed solvent of water and an organic solvent, followed by adding an organic substance to the dispersion, thereby obtaining a maxin dispersion in which the dispersion medium is an organic solvent. The organic substance is insoluble in water but soluble in organic solvents or mixed solvents of water and an organic solvent.

[0094] Furthermore, the maxin dispersion can be highly purified by weakly flocculating the maxin contained in the maxin dispersion and then performing solid-liquid separation. Preferably, the maxin dispersion is centrifuged at a centrifugal force of 2000 G or less to weakly flocculate or settle the maxin contained in the maxin dispersion, followed by solid-liquid separation into the solid (maxin) and the supernatant liquid. The centrifugal force during solid-liquid separation by centrifugation is more preferably 1000 G or less, and even more preferably 500 G or less. Another suitable example of solid-liquid separation is to add a poor solvent for maxin to the maxin dispersion to weakly flocculate the maxin, followed by solid-liquid separation into the solid and supernatant liquid. Another suitable example of solid-liquid separation is to filter the maxin dispersion using a filter with a pore size of 1 μm or less to perform solid-liquid separation. In the above-described solid-liquid separation, the solid after solid-liquid separation may contain a dispersion medium. From the viewpoint of purification efficiency, the amount of dispersion medium is preferably 1,000 parts by weight or less, more preferably 500 parts by weight or less, and even more preferably 300 parts by weight or less, per 10 parts by weight of the solid content. From the viewpoint of ease of redispersion, the amount is preferably 3 parts by weight or more, more preferably 10 parts by weight or more, and even more preferably 40 parts by weight or more.

[0095] Alternatively, after the solid-liquid separation, maxine may be redispersed in a mixed solvent of the dispersion medium before solvent replacement and the dispersion medium to be replaced with, the organic substance may be added to the dispersion and stirred, and after solid-liquid separation, the dispersion medium to be replaced with the solvent may be added to maxine to produce a maxine dispersion.

[0096] When Maxine is subjected to solid-liquid separation by centrifugal separation using strong centrifugal force, pressure filtration, or the like, it strongly aggregates and becomes impossible to redisperse. Furthermore, in the solvent replacement method described in Patent Document 1, which utilizes phase separation between water and an organic solvent, a saturated concentration of water is mixed into the organic solvent phase, reducing purity. Furthermore, it is not possible to prepare a Maxine dispersion using a water-miscible solvent as the dispersion medium. In contrast, by using the above-described method for producing a Maxine dispersion, solvent replacement can be performed while maintaining high dispersibility, and a Maxine dispersion with good dispersibility and high purity and concentration can be obtained.

[0097] Alternatively, the dispersing medium of the maxin dispersion may be solvent-substituted without causing the maxin to weakly aggregate. This maintains the state of maxin in the maxin dispersion, maintaining excellent maxin dispersibility. Preferred methods for solvent-substituting the dispersing medium of the maxin dispersion without causing the maxin to weakly aggregate include evaporating and distilling off the pre-substitution dispersing medium and then diluting with the desired dispersing medium, adding the desired dispersing medium to the maxin dispersion and removing the pre-substitution dispersing medium by distillation, and diafiltration. When preparing a maxin dispersion by solvent substitution, allowing the pre-substitution dispersing medium to remain can improve the dispersibility of maxin. The residual proportion of the pre-substitution dispersing medium is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, and even more preferably 5.0% by mass or more. From the viewpoint of solubility, the residual proportion of the pre-substitution dispersing medium is preferably 10.0% by mass or less, more preferably 1.0% by mass or less, and even more preferably 0.2% by mass or less.

[0098] The MAX phase-containing material, which is a precursor containing a MAX phase used in the method for producing a MAXXIN dispersion, includes a MAX phase that generates MAXXIN when etched with hydrofluoric acid and a phase that dissolves in hydrofluoric acid, and the MAX phase dissolves in hydrofluoric acid preferably accounts for 1.0% to 50.0% of the precursor. The MAX phase that dissolves in hydrofluoric acid is preferably one or more selected from the group consisting of transition metals, light metals, alloys of transition metals and light metals, transition metal carbides, transition metal carbonitrides, light metal carbides, light metal carbonitrides, and the MAX phase. The MAX phase that dissolves in hydrofluoric acid is different from the MAX phase that generates MAXXIN when etched with hydrofluoric acid.

[0099] A maxine dispersion obtained using such a MAX phase-containing material can reduce manufacturing variations such as variations in maxine particle size, and can also reduce the amount of impurities. Because the MAX phase crystals that produce maxine can be made larger and variations in maxine particle size can be reduced, the phase that dissolves in hydrofluoric acid is preferably 2.0% or more, and even more preferably 5.0% or more, relative to the precursor, and from the viewpoint of yield, the phase that dissolves in hydrofluoric acid is preferably 30.0% or less, and even more preferably 20.0% or less, relative to the precursor.

[0100] The content of the phase soluble in hydrofluoric acid in the MAX phase-containing material can be determined by subtracting the weight of the obtained MAXINE from the weight of the MAX phase-containing material used in the synthesis of MAXINE.

[0101] The MAX phase-containing material contains M, A, and X, where M is one or more transition metal elements, A is one or more elements selected from the group consisting of Al, Si, Ga, P, S, Ge, As, Cd, In, Sn, Tl, and Pb, and X is carbon or nitrogen, and where the molar ratio of M in the MAX phase-containing material is a, the molar ratio of A is b, and the molar ratio of X is c, it is preferable that a / c is 1.55 or more and 2.00 or less, and b / c is 0.55 or more and 1.00 or less. A maxine dispersion obtained using such a MAX phase-containing material can reduce the amount of transition metal carbide impurities.

[0102] The MAX phase-containing material preferably has a ratio of transition metal carbide to MAX phase, which forms MAXINE by etching with hydrofluoric acid, of 0.06 or less. The MAXINE dispersion obtained using such a MAX phase-containing material can reduce the amount of impurities of transition metal carbide.

[0103] In the XRD pattern of the MAX phase-containing material, the ratio (I1 / I2) of the intensity of the strongest diffraction peak of the phase soluble in hydrofluoric acid (I1) to the intensity of the strongest diffraction peak of the MAX phase that forms maxine upon etching with hydrofluoric acid (I2) is preferably 0.1 or more and 3.0 or less. A maxine dispersion obtained using such a MAX phase-containing material can reduce manufacturing variations, such as the particle size variation of maxine, and can also reduce the amount of impurities. Because this allows for the crystal size of the MAX phase that forms maxine to be larger and the particle size variation of maxine to be reduced, the intensity ratio (I1 / I2) of the above diffraction peaks is more preferably 0.3 or more, and even more preferably 0.5 or more. From the viewpoint of yield, the intensity ratio (I1 / I2) of the above diffraction peaks is more preferably 2.0 or less, and even more preferably 1.5 or less. When multiple phases soluble in hydrofluoric acid are contained, I1 is the sum of the strongest diffraction peak intensities of the respective phases.

[0104] Furthermore, the median diameter of the MAX phase-containing material used in the manufacturing method for the MAXIN dispersion is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more in order to increase the crystal size of MAXIN, and is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 50 μm or less in order to improve the yield and reaction rate during etching with hydrofluoric acid or the like.

[0105] Furthermore, since the above-mentioned Maxine dispersion has excellent dispersibility of Maxine in both water and organic solvents, Maxine membranes formed from the Maxine dispersion can reduce manufacturing variations.

[0106] The surface of the maxin film may also be oxidized. Specifically, only the surface of the maxin film is oxidized, and the rest of the maxin film is not oxidized. In other words, an unoxidized maxin film and an oxidized maxin film are stacked. This configuration allows the work function of the maxin film to be controlled. Therefore, by applying the maxin film to thin-film devices, the performance of the thin-film devices can be improved.

[0107] The surface of the maxin film may also be reduced. Specifically, only the surface of the maxin film is reduced, and the rest of the maxin film is not reduced; in other words, a non-reduced maxin film and a reduced maxin film are stacked. This configuration allows the work function of the maxin film to be controlled. Therefore, by applying the maxin film to thin-film devices, the performance of the thin-film devices can be improved.

[0108] The method for manufacturing a maxin film also includes a film-forming process. In the film-forming process, a solution containing a maxin dispersion is applied to a substrate surface to form a coating film, and the dispersion medium in the coating film is removed by evaporation or the like. In this way, a maxin film can be obtained. Furthermore, by applying an organic solution to the coating film or maxin film and then removing it, the work function of the maxin film can be controlled and the conductivity and durability can be improved. The solution containing a maxin dispersion may be only a maxin dispersion, or it may be a solution containing a maxin dispersion and various substances. The solution is, for example, a slurry obtained by mixing a maxin dispersion, a battery active material, a binder, and a solvent.

[0109] The MAXIN film is manufactured by spin-coating a solution containing the MAXIN dispersion onto the substrate surface, resulting in significantly smaller film thickness, surface roughness, and haze value than conventional MAXIN films.

[0110] As a method for producing the maxine film, in addition to spin coating, dip coating, spray coating, die coating, inkjet printing, screen printing, gravure printing, and offset printing can also be used.

[0111] Alternatively, a self-assembled monolayer (SAM) may be formed on the surface of the maxin membrane. A SAM can be formed on the surface of the maxin membrane by immersing the maxin membrane in a solution containing molecules that constitute the SAM. When producing a maxin membrane from a maxin dispersion containing maxin that has been surface-modified with an organic substance, it is preferable to heat the maxin membrane to remove the organic surface modifier before immersing the maxin membrane.

[0112] The materials that form the SAM have binding groups and functional groups.

[0113] The binding group of the SAM is a functional group that can be adsorbed onto the surface of Maxin. Specifically, the same functional group as the binding group of the organic substance that modifies the surface of Maxin in the Maxin dispersion described above can be used.

[0114] The functional group of the SAM may be, for example, an electron-donating functional group or an electron-withdrawing functional group. Specific examples of the functional group include hydrogen, halogen, nitro, alkyl (preferably methyl, isopropyl, or tertiary butyl), cyano, aryl (preferably phenyl, naphthyl, or thienyl), haloaryl (preferably pentafluorophenyl, 3-fluorophenyl, or 3,4,5-trifluorophenyl), alkenyl, alkynyl, amido, acyl, alkylcarbonyl, carboxy, alkoxy (preferably methoxy), aryloxy (preferably phenoxy or naphthyl), haloalkyl (preferably perfluoroalkyl), thiocyano, alkylsulfonyl, sulfonamido, amino, alkylamino (preferably methylamino), dialkylamino (preferably dimethylamino or diethylamino), and hydroxyl. The electron-donating substituent is more preferably an alkyl, amino, alkylamino, dialkylamino, aryl, or hydroxyl group. As electron-withdrawing substituents, halogen, cyano, haloaryl, and haloalkyl groups are preferred. By appropriately selecting these functional groups, the work function of the Maxine film can be controlled. For example, when an electron-withdrawing functional group is used, the work function tends to be high, while when an electron-donating functional group is used, the work function tends to be low.

[0115] The material forming the SAM may have a linker portion between the binding group and the functional group. The linker portion preferably has an alkyl chain, a perfluoroalkyl chain, a polyethylene oxide chain, a polypropylene oxide chain, or a structure containing two or more of these four types. In particular, a SAM-forming material having a linker portion with a linear alkyl chain structure having 2 to 40 carbon atoms is preferred because it can form a denser SAM. A branched structure may be introduced into the linker portion.

[0116] Furthermore, a MAXIN composite film, which includes a MAXIN film formed from a MAXIN dispersion and an organic film formed on the surface of the MAXIN film, can control the work function and improve conductivity and durability. The organic film is preferably composed of a carboxylic acid, a sulfonic acid, a thiol, or an amine.

[0117] The method for manufacturing the MAXIN composite membrane includes a first membrane forming step and a second membrane forming step.

[0118] In the first film-forming process, a solution containing a Maxin dispersion is applied to the surface of a substrate to form a coating film, and the dispersion medium in the coating film is removed by evaporation or other methods. This results in the formation of a Maxin film. The solution containing a Maxin dispersion may be a Maxin dispersion alone, or a solution containing a Maxin dispersion and various other substances. Examples of the solution include a slurry containing a Maxin dispersion, a battery active material, a binder, and a solvent, or a slurry containing a resin and a Maxin dispersion.

[0119] In the second film formation process, which is carried out after the first film formation process, an organic substance-containing solution is applied to the surface of the maxin membrane obtained in the first film formation process to form a coating film, and the dispersion medium in the coating film is removed to form an organic substance film. In this way, a maxin composite membrane can be obtained.

[0120] Because the MAXYN film is a conductive thin film with adjustable work function, it can be applied to a variety of electronic devices. For example, the MAXYN film can be bonded to the semiconductor interface through either a Schottky or ohmic junction, allowing the fabrication of Schottky barrier diodes and Schottky-gate field-effect transistors that utilize the Schottky junction between the MAXYN film and the semiconductor. The MAXYN film can also be bonded to power semiconductors such as SiC, GaN, GaAs, AlN, and diamond to fabricate power semiconductor elements.

[0121] Furthermore, since the Maxin film is transparent when it is a thin film several tens of nanometers thick, it can be used as a transparent conductive film. The Maxin transparent conductive film can be used as a transparent electrode for the backplane of a flat panel display, a transparent electrode and transparent counter electrode material for an electrochromic element, an electrode for a capacitive touch sensor, a transparent electrode, a hole transport layer and an electron transport layer for an organic EL element, and a transparent electrode, a hole transport layer and an electron transport layer for a solar cell (organic thin-film solar cell, perovskite solar cell, etc.). When used as a hole transport layer for an organic EL element or a solar cell, the higher the work function, preferably 5.0 eV or more. When used as an electron transport layer, the lower the work function, preferably 4.5 eV or less.

[0122] Because the Maxin membrane possesses surface plasmons, it can be used as a sensor that utilizes surface plasmon resonance. Because numerous functional groups are formed on the Maxin membrane surface, it can be functionalized by adsorbing various substances or by surface modification. For example, it can be used in gas sensors that detect gases adsorbed on the Maxin membrane surface, and biosensors that detect antigens by binding antibodies to the Maxin membrane surface.

[0123] A conductive composite can be formed by mixing the MAXYZIN dispersion with a resin. Examples of resins that can be mixed with the MAXYZIN dispersion include those listed above as binder resins. The conductive composite can be used, for example, as a conductive resin molded product, a conductive film, a conductive coating agent, an antistatic resin molded product, an antistatic film, or an antistatic coating agent.

[0124] Maxine can also be used in power storage devices such as batteries and capacitors. For example, a slurry containing a battery active material, a binder resin, and a Maxine dispersion can be formed into a film on a current collector to form the positive or negative electrode of a battery. Maxine can also be used as the negative electrode active material for lithium-ion batteries.

[0125] In addition, Maxine dispersions and Maxine films can also be used in electrodes for electrochemical systems, solid lubricants, electromagnetic wave shielding films, optical modulators, thermoelectric conversion materials, thermal conductive materials, gas barrier materials, filtration materials, water treatment films, antibacterial materials, conductive pastes, heaters, etc.

[0126] According to the embodiment described above, it has been discovered that there is a correlation between the dispersibility of maxin in maxin dispersion and the extinction ratio (A2 / A1) of the maximum value A2 of the extinction ratio in a specified wavelength range to the minimum value A1 of the extinction ratio in a specified wavelength range of maxin dispersion, and by controlling the extinction ratio (A2 / A1) within a specified range, maxin dispersion can have excellent maxin dispersibility regardless of whether the dispersion medium is water or an organic solvent.

[0127] Although the embodiments have been described above, the present invention is not limited to the above embodiments, but includes all aspects encompassed by the concept and scope of the claims of the present disclosure, and can be modified in various ways within the scope of the present disclosure.

[0128] Next, examples and comparative examples will be described, but the present disclosure is not limited to these examples.

[0129] (XRD Measurement) The XRD measurement conditions are as follows: Apparatus: Fully automatic horizontal multipurpose X-ray diffractometer SmartLab (Rigaku Corporation) X-ray tube: Cu X-ray output: 40 kV, 50 mA Filter: Cu_Kβ Sample preparation method: Filled into a silicon anti-reflection plate

[0130] (SEM-EDX Measurement) For the SEM-EDX measurement, JED-2300 (JEOL Ltd.) was used.

[0131] (UV-Visible Absorption Spectrum Measurement) UV-Visible Spectrophotometer UV-2600i (Shimadzu Corporation) was used for UV-Visible absorption spectrum measurement. When measuring the Maxin dispersion, an acrylic cuvette was used as the sample container for the water dispersion, and a quartz cuvette was used for the solvent dispersion. The optical path length was 10 mm. A cuvette filled with the dispersion medium was used as the blank. When measuring the Maxin film, the substrate on which the Maxin film was formed was used as the sample, and air was used as the blank.

[0132] (Measurement of Maxine Concentration) The concentration of Maxine in the dispersion was measured as follows. First, the Maxine dispersion was suction filtered using a PTFE membrane filter with a pore size of 0.2 μm, washed several times with water and ethanol, and vacuum dried at 60° C. for 16 hours to recover the solids in the Maxine dispersion. The weight of the resulting dry powder was divided by the weight of the filtered Maxine dispersion to determine the Maxine concentration.

[0133] (Measurement of particle size distribution) The particle size distribution of the solid content in the Maxine dispersion was measured using a laser diffraction / scattering particle size distribution measuring device LA-950V2 (manufactured by Horiba, Ltd.).

[0134] (Work Function Measurement) The work function of the Maxine film was measured using an air photoelectron yield spectrometer AC-2 (Riken Keiki Co., Ltd.).

[0135] (Production Example 1) Titanium carbide powder (manufactured by Kojundo Chemical Co., Ltd., product number TII02PB), titanium powder (manufactured by Kojundo Chemical Co., Ltd., product number TIE06PB), and aluminum powder (manufactured by Kojundo Chemical Co., Ltd., product number ALE15PB) were placed in a glass container in a molar ratio of 1:1:1, and after filling with nitrogen gas, the container was shook well to mix. The mixed raw material powder was filled into a carbon sintering mold and sintered in an Ar atmosphere at 1300°C for 2 hours. The heating rate was 19°C / min. The removed sintered body was polished with a file to obtain the MAX phase powder (MAX phase-containing material) of Production Example 1. XRD analysis of the obtained MAX phase powder revealed that Ti ２ AlC and Ti ３ AlC ２ It was a mixture of

[0136] (Production Example 2) Titanium carbide powder (manufactured by Kojundo Chemical Co., Ltd., product number TII02PB), titanium powder (manufactured by Kojundo Chemical Co., Ltd., product number TIE06PB), and aluminum powder (manufactured by Kojundo Chemical Co., Ltd., product number ALE15PB) were placed in a glass container in a molar ratio of 1:1:1, and after filling with nitrogen gas, the container was shook well to mix. The mixed raw material powder was filled into a carbon sintering mold and sintered in an Ar atmosphere at 1300°C for 2 hours. The heating rate was 120°C / min. The removed sintered body was polished with a file to obtain the MAX phase powder of Production Example 2. XRD analysis of the obtained MAX phase powder revealed that Ti ２ AlC and Ti ３ AlC ２ It was a mixture of

[0137] (Production Example 3) Titanium carbide powder (manufactured by Kojundo Chemical Co., Ltd., product number TII02PB), titanium powder (manufactured by Kojundo Chemical Co., Ltd., product number TIE06PB), and aluminum powder (manufactured by Kojundo Chemical Co., Ltd., product number ALE15PB) were placed in a glass container in a molar ratio of 1:1.2:1.2, filled with nitrogen gas, and then shook well to mix. The mixed raw material powder was filled into a carbon sintering mold and sintered at 1300°C for 2 hours in an Ar atmosphere. The heating rate was 47°C / min. The removed sintered body was polished with a file to obtain the MAX phase powder of Production Example 3. XRD analysis of the obtained MAX phase powder revealed that Ti ２ AlC and Ti ３ AlC ２ The ratio was calculated by the reference intensity ratio method, and it was found that Ti ２ AlC:Ti ３ AlC ２ The ratio was 68:31.

[0138] (Production Example 4) Titanium carbide powder (manufactured by Kojundo Chemical Co., Ltd., product number TII02PB), titanium powder (manufactured by Kojundo Chemical Co., Ltd., product number TIE06PB), and aluminum powder (manufactured by Kojundo Chemical Co., Ltd., product number ALE15PB) were placed in a glass container in a molar ratio of 1:5:5, and after filling with nitrogen gas, the container was shook well to mix. The mixed raw material powder was filled into a carbon sintering mold and sintered in an Ar atmosphere at 1300°C for 2 hours. The heating rate was 57°C / min. The removed sintered body was polished with a file to obtain the MAX phase powder of Production Example 4. XRD analysis of the obtained MAX phase powder revealed that Ti ２ AlC and Al １．１ Ti ０．９ The ratio was calculated by the reference intensity ratio method, and it was found that Ti ２ AlC:Al １．１ Ti ０．９ The ratio was 43:57.

[0139] (Production Example 5) Titanium carbide powder (manufactured by Kojundo Chemical Co., Ltd., product number TII02PB), titanium powder (manufactured by Kojundo Chemical Co., Ltd., product number TIE06PB), and aluminum powder (manufactured by Kojundo Chemical Co., Ltd., product number ALE15PB) were placed in a glass container in a molar ratio of 2:1:1, and after filling with nitrogen gas, the container was shook well to mix. The mixed raw material powder was filled into a carbon sintering mold and sintered in an Ar atmosphere at 1300°C for 2 hours. The heating rate was 57°C / min. The removed sintered body was polished with a file to obtain the MAX phase powder of Production Example 5. XRD analysis of the obtained MAX phase powder revealed that Ti ３ AlC ２ The ratio was calculated by the reference intensity ratio method, and it was found that Ti ３ AlC ２ :TiC=95:5.

[0140] (Production Example 6) Titanium carbide powder (manufactured by Kojundo Chemical Co., Ltd., product number TII02PB), titanium powder (manufactured by Kojundo Chemical Co., Ltd., product number TIE06PB), and aluminum powder (manufactured by Kojundo Chemical Co., Ltd., product number ALE15PB) were placed in a nylon pot in a molar ratio of 2:1:1. Zirconia balls were then placed inside the pot, and the pot was sealed after being filled with nitrogen gas. The pot was rotated on a pot mill turntable for 16 hours to uniformly mix the raw material powders. The mixed raw material powders were filled into a carbon sintering mold and sintered in an Ar atmosphere at 1350°C and 100 kPa for 2 hours. The heating rate was 19°C / min and the cooling rate was 10°C / min. The surface of the removed sintered body was polished and then pulverized using a stamp mill to obtain the MAX phase powder of Production Example 6. XRD analysis of the obtained MAX phase powder revealed that Ti ３ AlC ２ The peak intensity of the 111 plane of TiC and the Ti ３ AlC ２ The peak intensity ratio of the 104 plane was 0.18.

[0141] (Production Examples 7 to 12) MAX phase powders of Production Examples 7 to 12 were obtained in the same manner as in Production Example 6, except that the production conditions were changed as shown in Table 1.

[0142] (Production Example 125) Titanium powder, aluminum powder, and graphite powder were placed in a nylon pot in a molar ratio of 3.4:1.5:2.0, followed by the addition of zirconia balls. The pot was then filled with nitrogen gas and sealed. The pot was rotated on a pot mill turntable for 16 hours to uniformly mix the raw material powders. The mixed raw material powders were filled into a carbon sintering mold and sintered in an Ar atmosphere at 1400°C and 100 kPa for 2 hours. The heating rate was 20°C / min and the cooling rate was 10°C / min. The surface of the removed sintered body was polished and then pulverized using a stamp mill to obtain the MAX phase powder of Production Example 125. XRD analysis of the obtained MAX phase powder revealed that Ti ３ AlC ２ and Ti ２ It was a mixture of AlC and TiC. The peak intensity of the 111 plane of TiC and the ３ AlC ２ The peak intensity ratio of the 104 plane was 0.021.

[0143] The obtained MAX phase powder was subjected to XRD analysis, and the peak intensity of the 111 plane of the contained phase and TiC and Ti ３ AlC ２ The ratio of the peak intensity of the 104 plane of each of the above was investigated, and the results are shown in Table 1. Of the phases contained, all other than TiC are MAX phases. FIG. 1 shows XRD data of the MAX phase powders of Production Examples 1 and 2. FIG. 2 shows XRD data of the MAX phase powder of Production Example 3. FIG. 3 shows XRD data of the MAX phase powder of Production Example 4. FIG. 4 shows XRD data of the MAX phase powder of Production Example 5. FIG. 5 shows XRD data of the MAX phase powder of Production Example 12.

[0144]

[0145] (Production Example 13) 1.0 g of the MAX phase powder of Production Example 5 was added to 10 g of a 50.0% aqueous HF solution while stirring. After the addition of the MAX phase powder, the mixture was stirred at room temperature (24°C) for 3 hours. The reaction solution was then filtered, and the filtrate was repeatedly filtered and washed with ion-exchanged water until the filtrate became neutral. The washed filtrate was dried under reduced pressure at 80°C for 24 hours using a vacuum dryer, yielding 0.70 g of maxine, the inorganic compound of Production Example 13. When the obtained maxine was analyzed by XRD, a peak attributed to TiC was confirmed.

[0146] (Production Example 14) 1.0 g of the MAX phase powder of Production Example 11 was added to 10 g of a 50.0% aqueous HF solution while stirring. After the MAX phase powder was added, the mixture was stirred at room temperature for 3 hours. The reaction solution was then filtered, and the residue was repeatedly filtered and washed with ion-exchanged water until the filtrate became neutral. The washed residue was dried under reduced pressure at 80°C for 24 hours using a vacuum dryer, yielding 0.75 g of Maxine of Production Example 14. When the obtained Maxine was subjected to XRD analysis, a peak attributed to TiC was confirmed.

[0147] (Production Example 15) 1.0 g of the MAX phase powder of Production Example 12 was added to 10 g of a 50.0% aqueous HF solution while stirring. After the MAX phase powder was added, the mixture was stirred at room temperature for 3 hours. The reaction solution was then filtered, and the residue was repeatedly filtered and washed with ion-exchanged water until the filtrate became neutral. The washed residue was dried under reduced pressure at 80°C for 24 hours using a vacuum dryer, yielding 0.71 g of Maxine of Production Example 15. When the obtained Maxine was subjected to XRD analysis, no peaks attributed to TiC were confirmed.

[0148] (Production Example 16) 1.0 g of the MAX phase powder of Production Example 12 was added to 20 g of a 7.5% aqueous HF solution while stirring. After the addition of the MAX phase powder, the mixture was stirred at room temperature for 24 hours. The reaction solution was then filtered, and the residue was repeatedly filtered and washed with ion-exchanged water until the filtrate became neutral. The washed residue was dried under reduced pressure at 80°C for 24 hours using a vacuum dryer, yielding 0.69 g of Maxine of Production Example 16. When the obtained Maxine was subjected to XRD analysis, no peaks attributed to TiC were confirmed.

[0149] (Production Example 17) 1.0 g of the MAX phase powder of Production Example 12 was added to a stirred mixed acid obtained by mixing 3 g of a 50.0% aqueous HF solution, 12 g of 37% hydrochloric acid, and 5 g of ion-exchanged water. After the MAX phase powder was added, the mixture was stirred at 35 ° C. for 24 hours. The reaction solution was then filtered, and the filtrate was repeatedly filtered and washed with ion-exchanged water until the filtrate became neutral. The washed filtrate was dried under reduced pressure at 80 ° C. for 24 hours using a vacuum dryer, yielding 0.69 g of Maxine of Production Example 17. When XRD analysis of the obtained Maxine was performed, no peaks attributed to TiC were confirmed.

[0150] (Production Example 126) 1.0 g of the MAX phase powder of Production Example 125 was added to 20 g of a 10% HF aqueous solution while stirring. After the MAX phase powder was added, the mixture was stirred at 20°C for 24 hours. The reaction solution was then filtered, and the residue was repeatedly filtered and washed with ion-exchanged water until the filtrate became neutral. The washed residue was dried under reduced pressure at 80°C for 8 hours using a vacuum dryer, yielding 0.78 g of Maxine of Production Example 126. When the obtained Maxine was subjected to XRD analysis, no peaks attributed to TiC were confirmed.

[0151] (Production Example 110) 1.0 g of the MAX phase powder of Production Example 12 was added to a stirred mixed acid obtained by mixing 1.6 g of lithium fluoride, 15.7 g of 37% hydrochloric acid, and 4.3 g of ion-exchanged water. After the MAX phase powder was added, the mixture was stirred at 40°C for one week. The reaction solution was then filtered, and the filtrate was repeatedly filtered and washed with ion-exchanged water until the filtrate became neutral. The washed filtrate was dried under reduced pressure at 80°C for 24 hours using a vacuum dryer, yielding 0.82 g of Maxine of Production Example 110. When the obtained Maxine was subjected to XRD analysis, no peaks attributed to TiC were confirmed.

[0152] Figure 6 shows XRD data for Maxine of Production Example 13. Figure 7 shows XRD data for Maxine of Production Example 15. Figure 8 shows XRD data for Maxine of Production Example 16. Figure 9 shows particle size distribution data for Maxine of Production Example 16. Figure 10 is an SEM image of Maxine of Production Example 16. The results for Production Examples 13 to 17, 110, and 126 are shown in Table 2.

[0153] The peak intensity of the 111 plane of TiC in XRD measurement and Ti ３ AlC ２ Production Examples 12 and 125, in which the ratio of the peak intensity of the 104 plane to that of the 104 plane was 0.6 or less, did not contain TiC impurities in the maxine.

[0154]

[0155] (Production Example 18) 0.1 g of Maxine from Production Example 15, 0.5 g of tetramethylammonium hydroxide (TMAH) as a release agent, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 168 hours using a stirrer. 60 g of ion-exchanged water was added to 0.1 g of the stirred solution to obtain the Maxine dispersion of Production Example 18.

[0156] (Production Example 19) A Maxine dispersion of Production Example 19 was obtained in the same manner as in Production Example 18, except that the Maxine of Production Example 15 was replaced by the Maxine of Production Example 16.

[0157] (Production Example 20) A Maxine dispersion of Production Example 20 was obtained in the same manner as in Production Example 18, except that the Maxine of Production Example 15 was replaced by the Maxine of Production Example 17.

[0158] (Production Example 21) 0.1 g of Maxine from Production Example 16, 0.2 g of lithium chloride, and 1.6 g of ion-exchanged water were mixed and subjected to ultrasonic treatment at room temperature for 72 minutes using an ultrasonic cleaner. 65 g of ion-exchanged water was added as a dispersion medium to 0.05 g of the treated solution to obtain the Maxine dispersion of Production Example 21.

[0159] (Production Example 22) A Maxine dispersion of Production Example 22 was obtained in the same manner as in Production Example 21, except that the Maxine of Production Example 16 was replaced by the Maxine of Production Example 17.

[0160] (Production Example 23) 0.1 g of Maxine from Production Example 16, 0.9 g of benzyltrimethylammonium hydroxide, and 1.4 g of ion-exchanged water were mixed and stirred at room temperature for 144 hours. 60 g of ion-exchanged water was added to 0.06 g of the stirred solution to obtain a Maxine dispersion of Production Example 23.

[0161] (Production Example 24) 0.1 g of Maxine from Production Example 16, 0.9 g of benzyltrimethylammonium hydroxide, and 1.4 g of methanol were mixed and stirred at room temperature for 144 hours. 60 g of ion-exchanged water was added to 0.06 g of the stirred solution to obtain a Maxine dispersion of Production Example 24.

[0162] (Production Example 25) 0.1 g of Maxine from Production Example 16, 0.9 g of benzyltrimethylammonium hydroxide, and 1.4 g of methanol were mixed and stirred at room temperature for 144 hours. 60 g of NMP was added to 0.06 g of the stirred solution to obtain a Maxine dispersion of Production Example 25.

[0163] 0.1 g of Maxine from Production Example 16, 0.5 g of lithium hydroxide, and 4.0 g of water were mixed and stirred at room temperature for 72 hours. 60 g of ion-exchanged water was added to 0.12 g of the stirred solution to obtain a Maxine dispersion from Production Example 26.

[0164] (Production Example 27) A Maxine dispersion of Production Example 27 was obtained in the same manner as in Production Example 26, except that no release agent was used.

[0165] The Maxine dispersions of Production Examples 18 to 27 were subjected to ultraviolet-visible absorption spectroscopy and visual inspection. The results are shown in Tables 3 and 4. FIG. 11 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersions of Production Examples 18 to 20. FIG. 12 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersions of Production Examples 21 and 22. FIG. 13 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersion of Production Example 26. FIG. 14 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersion of Production Example 27.

[0166] The results of Production Examples 15 and 16 show that if the molar ratio of oxygen to fluorine (O / F) contained in Maxine is 1.5 or less, a dispersion liquid having an (A2 / A1) value of 1.15 or more can be prepared.

[0167]

[0168]

[0169] Production Example 28: 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred for 96 hours at room temperature using a stirrer. 30 g of ion-exchanged water was added to the stirred solution, which was then centrifuged at 450 G for 5 minutes to collect the cake-like sediment, yielding Maxine cake (Maxine dispersion) for Production Example 28.

[0170] (Production Example 29) 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 96 hours. 30 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 1000 G for 5 minutes. 1.8 g of ion-exchanged water was added as a dispersant to the precipitate, which was then redispersed. This dispersion was centrifuged at 30 G for 1 minute, and the supernatant was collected to obtain the Maxine dispersion of Production Example 29.

[0171] (Production Examples 30 to 39) Maxine dispersions of Production Examples 30 to 39 were obtained in the same manner as in Production Example 29, except that the conditions were changed as shown in Table 5.

[0172] (Production Example 40) 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 192 hours. 30 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 450 G for 5 minutes. The precipitate was redispersed by adding 2 g of ion-exchanged water and 0.1 g of methoxypropylamine as a dispersant. This dispersion was centrifuged at 30 G for 1 minute, and the supernatant was collected to obtain the Maxine dispersion of Production Example 40.

[0173] (Production Example 41) 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 360 hours. The mixture was then centrifuged at 450 G for 5 minutes, and the precipitate was redispersed in 4 g of ion-exchanged water. The mixture was then centrifuged at 450 G for 10 minutes, and the precipitate was redispersed in 4 g of ion-exchanged water and 0.018 g of methoxypropylamine. The mixture was then centrifuged at 1800 G for 10 minutes, and the precipitate was redispersed in 1 g of ion-exchanged water as a dispersant. This dispersion was then centrifuged at 30 G for 1 minute, and the supernatant was collected to obtain the Maxine dispersion of Production Example 41.

[0174] (Production Example 42) A Maxine dispersion of Production Example 42 was obtained in the same manner as in Production Example 41, except that aminoethoxyethanol was used instead of methoxypropylamine.

[0175] (Production Example 43) 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 360 hours. The mixture was then centrifuged at 450 G for 5 minutes, and the precipitate was redispersed in 4 g of ion-exchanged water. The mixture was then centrifuged at 450 G for 10 minutes, and the precipitate was redispersed in 4 g of ion-exchanged water. The mixture was then centrifuged at 1800 G for 10 minutes, and the precipitate was redispersed in 0.6 g of ion-exchanged water and 0.06 g of methoxypropylamine as dispersants. This dispersion was then centrifuged at 30 G for 1 minute, and the supernatant was collected to obtain the Maxine dispersion of Production Example 43.

[0176] (Production Example 44) 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 168 hours. Next, 30 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 450 G for 5 minutes. The precipitate was redispersed in 31 g of ion-exchanged water and 0.1 g of methoxypropylamine as a dispersant. This dispersion was centrifuged at 30 G for 1 minute, and the supernatant was collected to obtain the Maxine dispersion of Production Example 44.

[0177] (Production Examples 45 to 47) Maxine dispersions of Production Examples 45 to 47 were obtained in the same manner as in Production Example 44, except that the conditions were changed as shown in Table 5.

[0178] (Production Example 48) 10.0 g of Maxine from Production Example 16, 90.0 g of tetramethylammonium hydroxide, and 500.0 g of ion-exchanged water were mixed and stirred at room temperature for 96 hours. Next, 1.5 L of ion-exchanged water and 3.0 L of isopropanol were added to the stirred solution, causing the aggregates to precipitate and separate into a clear supernatant and a precipitate. The supernatant was removed by decantation, and 5 L of ion-exchanged water was added to the precipitate for redispersion. The redispersed dispersion was centrifuged at 1000 G for 30 minutes, and 500 g of ion-exchanged water was added as a dispersant to the precipitate for redispersion. This dispersion was centrifuged at 30 G for 1 minute, and the supernatant was collected to obtain the Maxine dispersion of Production Example 48.

[0179] (Production Example 49) 0.13 g of Maxine from Production Example 16, 0.46 g of tetramethylammonium hydroxide, and 1.0 g of ion-exchanged water were mixed and stirred at room temperature for 228 hours. Next, 33 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 1,000 G for 10 minutes. The precipitate was redispersed in 30 g of ion-exchanged water as a dispersant. This dispersion was centrifuged at 30 G for 1 minute, and the supernatant was collected to obtain the Maxine dispersion of Production Example 49.

[0180] (Production Example 50) A Maxine dispersion of Production Example 50 was obtained by adding 0.5 g of tetramethylammonium hydroxide to the Maxine dispersion of Production Example 31.

[0181] (Production Examples 51 and 52) Maxine dispersions of Production Examples 51 and 52 were obtained in the same manner as in Production Example 50, except that the conditions were changed as shown in Table 5.

[0182] (Production Examples 53 to 54) Maxine dispersions of Production Examples 53 and 54 were obtained in the same manner as in Production Example 29, except that the conditions were changed as shown in Table 5.

[0183] (Production Example 55) 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 96 hours. After stirring, 30 g of ion-exchanged water was added to the solution, followed by centrifugation at 450 G for 5 minutes. 30 g of ion-exchanged water was added to the precipitate, which was then redispersed. This was then centrifuged at 3000 G for 5 minutes, and 30 g of ion-exchanged water was added to the precipitate, which was then redispersed. This was then centrifuged at 3000 G for 5 minutes, and 1.8 g of ion-exchanged water was added as a dispersant to the precipitate, which was then redispersed. This dispersion was then centrifuged at 30 G for 1 minute, and the supernatant was collected to obtain the Maxine dispersion of Production Example 55.

[0184] The Maxine dispersions of Production Examples 28 to 55 were subjected to UV-visible absorption spectroscopy, visual inspection, particle size distribution measurement, concentration measurement, and atmospheric stability evaluation. The visual inspection examined the presence and size of aggregates and the color of the supernatant after the aggregates had settled. The atmospheric stability evaluation involved exposing the Maxine dispersions to the atmosphere to determine whether aggregates formed. The evaluation was rated as follows: A: No aggregates formed even after exposure to the atmosphere; B: Aggregates formed immediately after exposure to the atmosphere. The results are shown in Tables 5 and 6. Figure 15 is a graph showing the UV-visible absorption spectroscopy results for the Maxine dispersion of Production Example 33. Figures 16 and 17 are photographs of the appearance of the Maxine dispersion of Production Example 31 and SEM images of the powder obtained by drying the dispersion. Figure 18 is a photograph of the appearance of the Maxine dispersion of Production Example 51.

[0185] The results in Tables 5 and 6 show that no extinction peaks were observed in the ultraviolet-visible absorption spectrum of Maxin dispersions in which aggregation had occurred and the supernatant had become colorless and transparent. Maxin dispersions with an extinction ratio (A2 / A1) of 1.15 or higher had black supernatants, indicating that Maxin was dispersed. Furthermore, when the tetramethylammonium hydroxide concentration was 0.04 wt % or higher, Maxin dispersions had excellent dispersion stability in the atmosphere and did not produce aggregates even when exposed to the atmosphere.

[0186]

[0187]

[0188] (Production Example 111) 0.1 g of Maxine of Production Example 110 and 20 g of ion-exchanged water were mixed and subjected to ultrasonic treatment at room temperature for 8 minutes using an ultrasonic cleaner to obtain a Maxine dispersion of Production Example 111.

[0189] (Production Example 112) 0.1 g of Maxine from Production Example 17, 0.4 g of lithium chloride, and 1.6 g of ion-exchanged water were mixed and stirred at room temperature for 27 days using a stirrer. Next, 3 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 450 G for 5 minutes to remove the supernatant. The resulting precipitate was redispersed in ion-exchanged water, centrifuged at 1000 G for 10 minutes, and the supernatant was removed. This process was repeated three times. 1.5 g of ion-exchanged water was then added to the resulting precipitate, ultrasonicated for 16 minutes at room temperature using an ultrasonic cleaner, and centrifuged at 100 G for 3 minutes to remove the precipitate. The liquid excluding the precipitate was then recovered to obtain the Maxine dispersion of Production Example 112.

[0190] (Production Example 113) 0.4 g of Maxine from Production Example 17, 0.8 g of lithium chloride, and 6.8 g of ion-exchanged water were mixed and stirred for 27 days at room temperature using a stirrer. Next, 12 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 3000 G for 10 minutes to remove the supernatant. The resulting precipitate was redispersed in ion-exchanged water, centrifuged at 3000 G for 10 minutes, and the supernatant was removed. This process was repeated five times. Then, 10 g of ion-exchanged water was added to the resulting precipitate, ultrasonicated for 5 minutes at room temperature using an ultrasonic cleaner, centrifuged at 100 G for 5 minutes, and the liquid excluding the precipitate was recovered. This was centrifuged at 3000 G for 50 minutes to recover the precipitate, yielding a Maxine dispersion of Production Example 113.

[0191] (Production Example 114) 0.2 g of Maxine from Production Example 16, 0.4 g of lithium chloride, and 3.2 g of ion-exchanged water were mixed and stirred at room temperature for 1 week using a stirrer. Next, 6.2 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 450 G for 5 minutes, and the supernatant was removed. The resulting precipitate was redispersed in ion-exchanged water, centrifuged at 1000 G for 5 minutes, the supernatant was removed, and 0.5 g of ion-exchanged water was added to the resulting precipitate and redispersed. The mixture was centrifuged at 30 G for 1 minute, and the liquid excluding the precipitate was recovered, yielding a Maxine dispersion of Production Example 114.

[0192] The Maxine dispersions of Production Examples 111 to 114 were subjected to ultraviolet-visible absorption spectroscopy, visual inspection, particle size distribution measurement, concentration measurement, and atmospheric stability evaluation. The results are shown in Table 7. Figure 19 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersions of Production Examples 111 to 114.

[0193]

[0194] (Production Example 56) 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 96 hours using a stirrer. Next, 30 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 1000 G for 5 minutes. The precipitate was redispersed in 10 g of ion-exchanged water and 5 g of ethanol. 3 g of an ethanol solution of benzoic acid (33 wt%) was added to this dispersion, stirred for 48 hours, and further centrifuged at 450 G for 10 minutes to obtain a precipitate. The resulting precipitate was redispersed in 7 g of NMP, and then centrifuged at 450 G for 20 minutes. This purification process was repeated multiple times. The purified precipitate was recovered and added to 2 g of NMP to obtain the Maxine dispersion of Production Example 56.

[0195] (Production Examples 57 to 68, 106 to 109) Maxine dispersions of Production Examples 57 to 68 and 106 to 109 were obtained in the same manner as in Production Example 56, except that an ethanol solution (33 wt%) of a dispersant shown in Table 8 was used instead of the ethanol solution (33 wt%) of benzoic acid, and that the dispersant added to the purified precipitate was one shown in Table 8.

[0196] The materials used as dispersants are summarized below: DISPERBYK-145: Phosphate ester salt of a high molecular weight copolymer having pigment-affinity groups. Acid value: 76 mg KOH / g, amine value: 71 mg KOH / g. BYK-ET 3003: Phosphate ester. Acid value: 129 mg KOH / g. BYK-ET 3004: Alkyl ammonium salt of a copolymer having acidic groups. Acid value: 94 mg KOH / g, amine value: 94 mg KOH / g. BYK-LP C 22125: Acid value: 70 mg KOH / g. BYK-LP C 22124: Acid ester of a medium-polarity long-chain alcohol. Acid value: 85 mg KOH / g.

[0197] The Maxine dispersions of Production Examples 57 to 68 and 106 to 109 were subjected to ultraviolet-visible absorption spectroscopy, visual inspection, particle size distribution measurement, and concentration measurement. The results are shown in Tables 8 and 9. Figure 20 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersions of Production Examples 56 to 60. Figure 21 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersions of Production Examples 62 to 65. Figure 22 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersion of Production Example 106. Figure 23 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersions of Production Examples 107 to 109.

[0198] Maxine dispersions with a disappearance ratio (A2 / A1) of 1.15 or higher had few aggregates, the supernatant was black, and it was clear that Maxine was dispersed. Comparing Production Examples 107 to 109, the Maxine dispersions with higher water concentrations had larger (A2 / A1) values, indicating that Maxine was well dispersed.

[0199]

[0200]

[0201] (Production Example 69) 0.1 g of Maxine from Production Example 16, 0.5 g of tetramethylammonium hydroxide, and 3.5 g of ion-exchanged water were mixed and stirred at room temperature for 96 hours using a stirrer. Next, 30 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 1000 G for 5 minutes. 10 g of ion-exchanged water was added to the precipitate to redisperse it. 0.1 g of this dispersion was added with 0.1 g of phenethylamine as a dispersant and 1 g of NMP as a dispersion medium, and the mixture was stirred thoroughly to obtain the Maxine dispersion of Production Example 69.

[0202] (Production Examples 70 to 71) Maxine dispersions of Production Examples 70 to 71 were obtained in the same manner as in Production Example 69, except that the dispersants shown in Table 10 were used instead of phenethylamine.

[0203] (Production Example 72) As shown in Table 10, a Maxine dispersion of Production Example 72 was obtained in the same manner as in Production Example 69, except that no dispersant was used.

[0204] The Maxine dispersions of Production Examples 69 to 72 were subjected to ultraviolet-visible absorption spectroscopy and visual inspection. The results are shown in Tables 10 and 11. Figure 24 is a graph showing the ultraviolet-visible absorption spectroscopy results for the Maxine dispersions of Production Examples 69, and 71 to 72.

[0205]

[0206]

[0207] (Production Example 115) 0.4 g of Maxine from Production Example 17, 0.8 g of lithium chloride, and 6.8 g of ion-exchanged water were mixed and stirred at room temperature for 27 days using a stirrer. Next, 12 g of ion-exchanged water was added to the stirred solution, and the mixture was centrifuged at 1000 G for 10 minutes, and the supernatant was removed. The resulting precipitate was redispersed in ion-exchanged water, centrifuged at 1000 G for 10 minutes, and the supernatant was removed. This process was repeated three times. Then, 3 g of ion-exchanged water was added to the resulting precipitate, and the mixture was ultrasonicated at room temperature for 16 minutes using an ultrasonic cleaner. Then, the mixture was centrifuged at 100 G for 3 minutes, and the precipitate-free liquid was recovered. 14 g of NMP and 0.8 g of benzoic acid were added to the recovered liquid, and the mixture was stirred at room temperature for 2 days. The mixture was then centrifuged at 1000 G for 15 minutes, and the supernatant was removed. NMP was added to the obtained precipitate, and the mixture was centrifuged at 1000 G for 15 minutes and the supernatant was removed. This process was repeated three times, after which 1 g of NMP was added to the obtained precipitate, and the mixture was ultrasonicated at room temperature for 16 minutes using an ultrasonic cleaner. The mixture was then centrifuged at 100 G for 1 minute, and the liquid from which the precipitate had been removed was recovered, yielding a Maxine dispersion for Production Example 115.

[0208] (Production Example 116) 0.02 g of Maxine from Production Example 110 was mixed with 4 g of ion-exchanged water and ultrasonicated at room temperature for 8 minutes using an ultrasonic cleaner to obtain a Maxine dispersion. 0.005 g of dodecylamine and 4 g of toluene were added to this dispersion and stirred for 1 week. After stirring, the reaction solution separated into a black toluene phase and a colorless, transparent water phase. The toluene phase was recovered and ultrasonicated for 3 minutes using an ultrasonic cleaner to obtain the Maxine dispersion of Production Example 116.

[0209] (Production Example 117) A Maxine dispersion of Production Example 117 was obtained in the same manner as in Production Example 116, except that the amount of dodecylamine added was changed to 0.02 g.

[0210] (Production Example 118) A Maxine dispersion of Production Example 118 was obtained in the same manner as in Production Example 116, except that the amount of dodecylamine added was changed to 0.05 g.

[0211] (Production Example 119) 0.02 g of Maxine from Production Example 110 was mixed with 4 g of ion-exchanged water, and the mixture was subjected to ultrasonic treatment at room temperature for 8 minutes using an ultrasonic cleaner to obtain a Maxine dispersion. 0.2 g of dodecylamine and 4 g of toluene were added to this dispersion, and the mixture was stirred for one week to obtain the Maxine dispersion of Production Example 119. This dispersion formed a grayish-white emulsion of a toluene phase and an aqueous phase.

[0212] (Production Example 124) 0.05 g of Maxine of Production Example 110, 0.25 g of dodecylamine, and 5 g of toluene were mixed and stirred for one week, to obtain a Maxine dispersion of Production Example 124.

[0213] (Production Example 127) 1 g of the Maxine dispersion of Production Example 118 was centrifuged at 1,000 G for 10 minutes, and the supernatant was removed. Ethanol was added to the resulting precipitate so that the total amount was 1 g, and then the mixture was subjected to ultrasonic treatment at room temperature for 5 minutes using an ultrasonic cleaner, yielding the Maxine dispersion of Production Example 127.

[0214] (Production Example 128) 1 g of the Maxine dispersion of Production Example 118 was centrifuged at a centrifugal force of 1,000 G for 10 minutes, and the supernatant was removed. n-Hexane was added to the resulting precipitate so that the total amount was 1 g, and then the mixture was subjected to ultrasonic treatment at room temperature for 5 minutes using an ultrasonic cleaner, yielding the Maxine dispersion of Production Example 128.

[0215] (Production Example 129) 1 g of the Maxine dispersion of Production Example 118 was centrifuged at 1,000 G for 10 minutes, and the supernatant was removed. Toluene was added to the resulting precipitate so that the total amount was 1 g, and then ultrasonic treatment was performed at room temperature for 5 minutes using an ultrasonic cleaner to obtain the Maxine dispersion of Production Example 129.

[0216] UV-visible absorption spectrum measurements, visual inspections, and concentration measurements were performed on the Maxine dispersions of Production Examples 115 to 119, 124, and 127 to 129. The results are shown in Table 12. Figure 25 is a graph showing the UV-visible absorption spectrum results for the Maxine dispersions of Production Examples 115 to 119.

[0217]

[0218] (Production Example 73) A glass slide whose surface had been UV-cleaned with ozone for 5 minutes was used as the substrate. A 0.1 ml diluted dispersion of the Maxine dispersion of Production Example 49 adjusted to approximately 0.3% was dropped onto the substrate and spin-coated at 1000 rpm for 60 seconds. The coated substrate was dried in nitrogen at 80°C for 5 minutes to obtain the Maxine film of Production Example 73.

[0219] (Production Examples 74, 77, 78, 88) Maxine membranes of Production Examples 74, 77, 78, 88 were obtained in the same manner as in Production Example 73, except that the Maxine dispersion shown in Table 13 was used instead of the Maxine dispersion of Production Example 49.

[0220] (Production Example 75) A glass slide whose surface had been UV-ozone cleaned for 5 minutes was used as the substrate. A diluted dispersion of the Maxine dispersion of Production Example 39 adjusted to approximately 0.3% was prepared and ultrasonically cleaned for 24 minutes. 0.1 ml of this diluted dispersion was dropped onto the substrate and spin-coated at 1000 rpm for 60 seconds. The coated substrate was dried in nitrogen at 80°C for 5 minutes to obtain the Maxine film of Production Example 75.

[0221] (Production Example 76) A glass slide whose surface had been UV-ozone cleaned for 5 minutes was used as the substrate. A diluted dispersion of the Maxine dispersion of Production Example 39 adjusted to approximately 0.3% was prepared and ultrasonically cleaned for 72 minutes. 0.1 ml of this diluted dispersion was dropped onto the substrate and spin-coated at 1000 rpm for 60 seconds. The coated substrate was dried in nitrogen at 80°C for 5 minutes to obtain the Maxine film of Production Example 76.

[0222] (Production Example 79) A glass slide whose surface had been UV-ozone cleaned for 5 minutes was used as the substrate. A diluted dispersion of the Maxine dispersion of Production Example 33 adjusted to approximately 0.3% was prepared and ultrasonically cleaned for 72 minutes. 0.1 ml of this diluted dispersion was dropped onto the substrate and spin-coated at 1000 rpm for 60 seconds. The coated substrate was dried in nitrogen at 80°C for 5 minutes to obtain the Maxine film of Production Example 79.

[0223] (Production Example 80) A glass slide whose surface had been UV-ozone cleaned for 5 minutes was used as the substrate. A diluted dispersion of the Maxine dispersion of Production Example 33 adjusted to approximately 0.3% was prepared and ultrasonically cleaned for 24 minutes. 0.1 ml of this dispersion was dropped onto the substrate and spin-coated at 1000 rpm for 60 seconds. The coated substrate was dried in nitrogen at 80°C for 5 minutes to obtain the Maxine film of Production Example 80.

[0224] (Production Example 81) A glass slide whose surface had been UV-cleaned with ozone for 5 minutes was used as the substrate. A diluted dispersion of the Maxine dispersion of Production Example 39 was prepared at approximately 0.3%. This was centrifuged at 3000 G for 5 minutes, and the supernatant dispersion was recovered. 0.1 ml of this dispersion was dropped onto the substrate, and spin-coated at 1000 rpm for 60 seconds. The coated substrate was dried in nitrogen at 80°C for 5 minutes, yielding the Maxine film of Production Example 81.

[0225] (Production Examples 82 to 87) The Maxine membranes of Production Examples 82 to 87 were obtained in the same manner as Production Example 73, except that the Maxine dispersion shown in Table 13 was used instead of the Maxine dispersion of Production Example 49, and the additives shown in Table 13 were added to the Maxine dispersion.

[0226] (Production Example 89) The Maxine dispersion prepared for producing the Maxine membrane of Production Example 88 was exposed to the atmosphere for 30 days, and the Maxine membrane of Production Example 89 was obtained in the same manner as in Production Example 73 using the Maxine dispersion.

[0227] (Production Examples 120 to 123) The substrate used was a slide glass whose surface had been cleaned with UV ozone for 5 minutes. A 0.1 ml diluted dispersion of the Maxine dispersion of Production Examples 111 to 114, adjusted to approximately 0.5%, was dropped onto the substrate and spin-coated at 1000 rpm for 60 seconds. The coated substrate was dried in nitrogen at 80°C for 5 minutes to obtain the Maxine films of Production Examples 120 to 123.

[0228] The appearance, conductivity, and optical properties of the Maxin films of Production Examples 73 to 89 were evaluated. The appearance evaluation was ranked as follows: a uniform coating film without aggregation or repellency was ranked 1; a coating film with some aggregation or repellency was ranked 2; and a coating film that could not be formed due to aggregation or repellency was ranked 3. The conductivity of the Maxin films was measured by measuring the surface resistance using a four-terminal method. The transmittance of the Maxin films at a wavelength of 555 nm was also measured using an ultraviolet-visible absorption spectrometer. The results are shown in Tables 13 and 14.

[0229] The appearance, conductivity, and optical properties of the Maxin films of Production Examples 120 to 123 were evaluated. The appearance evaluation was ranked as follows: a uniform coating film without aggregation or repellency was ranked 1; a coating film with some aggregation or repellency was ranked 2; and a coating film that could not be formed due to aggregation or repellency was ranked 3. The conductivity of the Maxin films was measured by measuring the surface resistance using a four-terminal method. The transmittance of the Maxin films at a wavelength of 555 nm was also measured using an ultraviolet-visible absorption spectrometer. The results are shown in Table 15.

[0230] FIG. 26 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 74 to 76. FIG. 27 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 78 to 80. FIG. 28 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 73, 77, and 81. FIG. 29 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 83 to 84 and 86. FIG. 30 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 82, 85, and 87. FIG. 31 is a graph showing the results of ultraviolet-visible absorption spectra of the diluted dispersions used in Production Examples 88 and 89.

[0231] Fig. 32 is a graph showing the results of the transmission spectra of the Maxine films of Production Examples 74 to 80 and 88. Fig. 33 is a graph showing the results of the transmission spectra of the Maxine films of Production Examples 83 and 86. Fig. 34 is a graph showing the results of the transmission spectra of the Maxine films of Production Examples 121 and 122.

[0232] As shown in Tables 13 and 14, the larger the disappearance ratio (A2 / A1) of a Maxine dispersion, the more efficiently a Maxine film was formed without aggregation or repellency. Furthermore, the larger the disappearance ratio ((A1+A2) / A3) of a Maxine dispersion, the more efficiently a Maxine film was formed. Furthermore, as shown in Table 15, it was found that a similar trend was observed for Maxine dispersions using different release agents.

[0233]

[0234]

[0235]

[0236] (Production Example 90) A slide glass whose surface had been UV ozone cleaned for 5 minutes was used as the substrate. 0.1 ml of the Maxine dispersion liquid from Production Example 38 was dropped onto the substrate and spin-coated at 1000 rpm for 60 seconds. The coated substrate was dried in nitrogen at 80°C for 5 minutes to obtain the Maxine film of Production Example 90.

[0237] (Production Example 91) A solution was prepared by dissolving 20 ml of methoxypropylamine in 10 g of ethanol. The Maxine membrane of Production Example 90 was immersed in this solution for 3 hours, washed with ethanol, and dried by air blowing to obtain the Maxine membrane of Production Example 91.

[0238] (Production Examples 92 to 103) Maxine membranes of Production Examples 92 to 103 were obtained in the same manner as in Production Example 91, except that the treating agent shown in Table 16 was used instead of methoxypropylamine.

[0239] (Production Example 104) The Maxine membrane of Production Example 90 was subjected to UV ozone treatment for 5 minutes to obtain the Maxine membrane of Production Example 104.

[0240] (Production Example 105) The Maxine membrane of Production Example 90 was immersed in ethanol for 3 hours and then dried with an air blower to obtain the Maxine membrane of Production Example 105.

[0241] The conductivity and work function of the Maxine films of Production Examples 90 to 105 were evaluated. The conductivity was measured by measuring the surface resistance using a four-terminal method. The work function was also measured using an atmospheric photoelectron yield spectrometer. The results are shown in Tables 16 and 17.

[0242]

[0243]

[0244] As shown in the above results, Maxine dispersions containing Maxine and a dispersion medium and having a disappearance ratio (A2 / A1) of 1.15 or greater exhibited excellent Maxine dispersibility in both water and organic solvents. Furthermore, Maxine films prepared using such Maxine dispersions could be applied to spin coating, and had significantly smaller film thicknesses, surface roughness, and haze values ​​than conventional Maxine films. On the other hand, Maxine dispersions with a disappearance ratio (A2 / A1) of less than 1.15 exhibited poor Maxine dispersibility.

Claims

1. A Maxine dispersion comprising Maxine and a dispersion medium, the extinction ratio (A2 / A1) of the maximum value A2 of the extinction ratio in a wavelength range of 300 nm or more and 900 nm or less to the minimum value A1 of the extinction ratio in a wavelength range of 300 nm or more and 900 nm or less (however, if there are multiple minimum values ​​in the wavelength range of 300 nm or more and 900 nm or less, the minimum value on the longest wavelength side among the multiple minimum values ​​is selected as the minimum value A1, and if there are multiple maximum values ​​in the wavelength range of 300 nm or more and 900 nm or less, the maximum value on the longest wavelength side among the multiple maximum values ​​is selected as the maximum value A2) being 1.15 or more.

2. The maxine dispersion according to claim 1, wherein the solids concentration of the maxine is 0.1% by mass or more.

3. The maxine dispersion according to claim 1, wherein the median diameter d50 of the maxine is 4.0 μm or more.

4. The maxine dispersion liquid according to claim 1, wherein the relationship (A1+A2) / A3 between the minimum value A1, the maximum value A2, and the peak wavelength in the wavelength range of 300 nm to 350 nm, or the extinction degree value A3 at a wavelength of 330 nm when no peak exists in the wavelength range of 300 nm to 350 nm, is 0.70 or more and 1.70 or less.

5. The maxine dispersion according to claim 1, wherein the dispersion medium is water or a hydrophilic organic solvent, and the disappearance ratio (A2 / A1) is 1.20 or more.

6. The maxine dispersion of claim 1, wherein the dispersion medium is a hydrophobic organic solvent.

7. The maxine dispersion of claim 1, wherein the dispersion medium is water, N-methyl-2-pyrrolidone, dimethylacetamide, N,N-dimethylformamide or an alcohol.

8. The maxine dispersion according to claim 1, wherein maxine before being contained in the maxine dispersion contains M, O and F, M is one or more transition metal elements, the molar ratio of O being b and the molar ratio of F being c, (b / c) is 0.60 or more and 2.30 or less, and the half-width of the diffraction peak of the (110) plane obtained by X-ray diffraction analysis is 0.60° or less.

9. A maxine membrane formed from the maxine dispersion of any one of claims 1 to 8.

10. The maxine membrane of claim 9, wherein the surface of the maxine membrane is oxidized.

11. The maxine membrane of claim 9, wherein the surface of the maxine membrane is reduced.

12. A method for producing a maxine film, comprising a film-forming step of applying a solution containing the maxine dispersion liquid according to any one of claims 1 to 8 to a substrate surface to form a maxine film.

13. A maxine composite membrane comprising a maxine membrane formed from the maxine dispersion according to any one of claims 1 to 8, and an organic membrane provided on the surface of the maxine membrane.

14. The maxine composite membrane of claim 13, wherein the organic membrane is composed of a carboxylic acid, a sulfonic acid, a thiol, or an amine.

15. A method for producing a maxine composite membrane, comprising: a first film-forming step of applying a solution containing the maxine dispersion liquid according to any one of claims 1 to 8 to a substrate surface to form a maxine membrane; and a second film-forming step of applying an organic-containing solution to the maxine membrane to form an organic membrane.

16. A MAX phase-containing material comprising M, A, and X, wherein M is one or more transition metal elements, A is one or more elements selected from the group consisting of Al, Si, Ga, P, S, Ge, As, Cd, In, Sn, Tl, and Pb, and X is carbon or nitrogen, wherein a is a molar ratio of M, b is a molar ratio of A, and c is a molar ratio of X, in which a / c is 1.55 or more and 2.00 or less, and b / c is 0.55 or more and 1.00 or less.

17. The MAX phase-containing material according to claim 16, comprising a MAX phase and a phase that dissolves in hydrofluoric acid, the content of said phase being 1.0% or more and 50.0% or less.

18. The MAX phase-containing material according to claim 16 or 17, wherein the ratio (I1 / I2) of the intensity (I1) of the strongest diffraction peak of the phase soluble in hydrofluoric acid to the intensity (I2) of the strongest diffraction peak of the MAX phase in the XRD pattern of the MAX phase-containing material is 0.1 or more and 3.0 or less.

Images