JP7006339B2 - Layered material dispersion and its manufacturing method, manufacturing method of layered material laminate, and layered material laminate - Google Patents

Description

The present disclosure relates to a layered material dispersion, a method for producing the same, a method for producing a layered material laminate, and a layered material laminate.

Graphene, which is a single-layer structure of graphite, is a two-dimensional planar crystal in which six-membered carbon rings are connected in the plane direction, and is attracting attention because it has excellent properties such as excellent conductivity and thermal conductivity. There is. In order to bring out the excellent conductivity and thermal conductivity of graphene, it is required to use a single layer of graphene or flaky graphite having multiple layers in the range of 100 nm or less.

Nanosheets made by monolayering inorganic layered substances including simple substances and layered compounds having a layered crystal structure similar to graphite, and flakes such as multi-layered nanosheets in the range of 100 nm or less are also extremely thin compared to the thickness. Therefore, the surface size is usually on the order of μm, which is a highly anisotropic material. Nanosheets of such inorganic layered substances or flakes such as those having multiple layers in the range of 100 nm or less have a high specific surface area, special physical properties due to their two-dimensional structure, and new physical properties. Because of this, it is attracting attention as a new category of nanomaterials, along with nanoparticles and nanotubes.

Chemical vapor deposition (CVD method), solution coating method, and the like are known as film forming methods for layered materials such as graphite and flakes of inorganic layered substances. Among them, solution coating is possible at low cost. The law is drawing attention.
When a layered material such as graphite or a thin piece of an inorganic layered substance is formed by the solution coating method, it is necessary to disperse the layered material in the solution.

As a method of exfoliating from graphite to obtain flaky graphite, a method of adding graphite to a polar solvent such as water and dispersing it using ultrasonic waves is known (for example, Non-Patent Document 1). However, these methods have a problem that the distribution of the thickness of the exfoliated graphite is widened and the graphite that is not sufficiently thinned remains in a non-negligible manner.
Further, it is disclosed that a two-dimensional nanosheet can be produced by peeling a layered compound such as hexagonal boron nitride or molybdenum sulfide in a liquid phase using ultrasonic irradiation in the same manner as graphite (similar to graphite). Non-Patent Document 2). However, according to the method of Non-Patent Document 2, both the one in which the miniaturization in the in-plane direction is extremely advanced and the one in which the miniaturization is insufficient are produced, and the particle size tends to be widely distributed. If the miniaturization in the in-plane direction is extremely advanced, the mechanical strength of the laminated film may be lowered when the laminated film in which the thin sections of the layered compound are laminated is formed, or electricity, heat, etc. may be generated in the laminated film. It is not preferable for improving the function because it causes an increase in contact resistance between flakes during transmission. Further, in the case where the miniaturization did not proceed, there was a high tendency to obtain many flakes thicker than 100 nm, and the yield was poor for the monolayered nanosheets or the flakes having multiple layers in the range of 100 nm or less.

Patent Document 1 states that a boron nitride nanosheet-containing dispersion liquid in which boron nitride nanosheets are dispersed in an ionic liquid can be obtained by mixing boron nitride with an ionic liquid and peeling off the boron nitride by ultrasonic irradiation or the like. Further, it is disclosed that the boron nitride nanosheet composite including the boron nitride nanosheet and the ionic liquid adsorbed on the boron nitride nanosheet is excellent in dispersibility in a solvent or a resin. However, the ionic liquid used in Patent Document 1 is strongly adsorbed on the boron nitride flakes and is difficult to remove by washing or firing. It is presumed that the organic cations used in ionic liquids are particularly susceptible to adsorption to boron nitride flakes. Therefore, although the boron nitride flakes adsorbed by the ionic liquid obtained in Patent Document 1 are excellent in dispersibility, it is difficult to form a laminated film or a self-supporting film in which the flakes are laminated. In particular, it has been difficult to produce a laminated film in which boron nitride flakes are directly adjacent to each other so as not to impair the special physical properties caused by the two-dimensional structure. A laminated film in which pieces of boron nitride adsorbed by an ionic liquid are laminated is considered to be inferior in heat dissipation performance, for example.

From the above, nanosheets of layered materials such as graphite and flakes of inorganic layered materials or flakes such as multi-layered in the range of 100 nm or less have higher yields in a state where miniaturization in the in-plane direction does not proceed too much. It was hoped that it would be obtained. In addition, nanosheets of layered materials or flakes that are multi-layered in the range of 100 nm or less are difficult to aggregate and are in a state where it is easy to form a laminated body having excellent special physical properties due to a two-dimensional structure, particularly a self-supporting film. It was hoped that it would be obtained in.

JP 2015-187057

"JACS", 2009, 131, p. 3611-3620 "Science", 2011,331, p. 568-571

The present disclosure has been made in view of the above circumstances, and uses a layered material dispersion that is difficult to aggregate and easily forms a self-supporting film in which pieces of layered substances are laminated, a method for producing the same, and the layered material dispersion. It is an object of the present invention to provide a method for manufacturing a layered material laminate and a layered material laminate having high mechanical strength.

One embodiment of the present disclosure is a piece of a layered material excluding swellable clay minerals, in which the average surface spacing by X-ray diffractometry is within the range of ± 0.01 nm of the average surface spacing of the layered material, and the average thickness. Provided is a layered material dispersion containing 1 part by mass or more and 100 parts by mass or less of an organic compound satisfying the following (i), (ii) and (iii) with respect to 1 part by mass of a layered material having a thickness of 100 nm or less. ..
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.

One embodiment of the present disclosure provides a layered material dispersion having a viscosity of the layered material dispersion at 25 ° C. of 300 mPa · s or more.

One embodiment of the present disclosure provides a layered material dispersion in which the total content of the layered material and the organic compound is 90% by mass or more.

Further, in one embodiment of the present disclosure, 1 part by mass or more and 100 parts by mass or less of an organic compound satisfying the following (i), (ii) and (iii) is added to 1 part by mass of a layered substance excluding swellable clay minerals. In addition, a method for producing a layered material dispersion having a kneading step is provided.
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.

Further, one embodiment of the present disclosure is a layered material laminate comprising a step of forming or molding a layered material dispersion of the above-mentioned one embodiment of the present disclosure, wherein the layered material which is a piece of the layered substance is laminated. Provides a manufacturing method for.

Further, one embodiment of the present disclosure is a piece of a layered material excluding swellable clay minerals, in which layered materials having an average thickness of 100 nm or less are laminated, and the average surface spacing by X-ray diffraction method is the layered material. A layered material laminate having an average surface spacing of ± 0.01 nm.
It contains 0.1% by mass or more and 5% by mass or less of an organic compound satisfying the following (i), (ii) and (iii), and has an elastic modulus of 3 GPa or more in a tensile test based on JIS-K7127 (1999). , A layered material laminate is provided.
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.

According to one embodiment of the present disclosure, a layered material dispersion that is difficult to aggregate and easily forms a self-supporting film in which pieces of layered substances are laminated, a method for producing the same, and a layered material laminate using the layered material dispersion. As well as a layered material laminate having high mechanical strength can be provided.

It is one of the laser micrographs of the layered material 1 which concerns on this disclosure obtained in Example 1. Table 5 of the literature (RF Fedors, POLYMER ENGINEERING AND SCIENCE, 14 (1974) 147-154) is shown. The continuation of Table 5 of the literature (RF Fedors, POLYMER ENGINEERING AND SCIENCE, 14 (1974) 147-154) is shown.

Hereinafter, embodiments and examples of the present disclosure will be described with reference to the drawings and the like. However, the present disclosure can be carried out in many different modes, and is not construed as being limited to the description contents of the embodiments and examples illustrated below. In addition, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is just an example, and the interpretation of the present disclosure is used. It is not limited. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate. Further, for convenience of explanation, the phrase "upper" or "lower" may be used for explanation, but the vertical direction may be reversed.
In the present specification, when a configuration such as a member or a region is "above (or below)" another configuration such as another member or another region, unless otherwise specified. This includes not only the case of being directly above (or directly below) the other configuration, but also the case of being above (or below) the other configuration, that is, another configuration in between above (or below) the other configuration. Including the case where the element is included.

Hereinafter, a layered material dispersion and a method for producing the same, a layered material laminate, and a method for producing the layered material laminate according to the first embodiment of the present disclosure will be described in order.
The boiling point and melting point in the present disclosure are the boiling point and melting point at 1 atm, and other physical properties are also measured at 1 atm unless otherwise specified.

I. Layered Material Dispersion The layered material dispersion of one embodiment of the present disclosure is a piece of a layered material excluding swelling clay minerals, and the average surface spacing by the X-ray diffractometry is ± 0.01 nm. Contains 1 part by mass or more and 100 parts by mass or less of an organic compound satisfying the following (i), (ii) and (iii) with respect to 1 part by mass of a layered material having an average thickness of 100 nm or less. It is a layered material dispersion.
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.

In the present disclosure, the layered substance excluding the swellable clay mineral includes graphite (graphite) and a simple substance or a layered compound having a layered crystal structure similar to graphite, and includes the swellable clay mineral. do not have. The swellable clay mineral refers to a clay mineral that swells only by stirring in water or an organic solvent. Specifically, it means that the swelling power is 5 mL / 2 g or more, and the swelling power is a method according to the standard test method JBAS-104-77 of the Japan Bentonite Industry Association and the method for measuring the swelling power of bentonite (powder). Then, 2.0 g of clay mineral powder is put into a 100 mL measuring cylinder containing 50 mL of water little by little, and the clay mineral is naturally settled and swollen. It can be measured by reading the apparent volume of the clay mineral. The swellable clay minerals include smectites such as montmorillonite and bentonite and swellable clay minerals such as vermiculite (Clay Handbook, 2nd Edition, edited by Japan Clay Society, Gihodo Publishing Co., Ltd., April 30, 1987. Issuance) and so on. On the other hand, examples of the non-swellable clay mineral having a swelling power of less than 5 mL / 2 g include natural or synthetic mica, talc, kaolin, pyrophyllite and the like.

Such a layered material has a layered crystal structure, and is a layered structure in which unit layers formed by strong bonds such as covalent bonds and ionic bonds are laminated mainly via a weak van der Waals force. Has.
Among the layered substances, examples thereof include graphite (graphite) and phosphorus (particularly black phosphorus) as simple substances, and examples of the layered compound include hexagonal boron nitride (h-BN), which is a compound similar to graphite. Boron Nitride Containing Layered Structures such as Rhombus Crystal Boron Nitride (r-BN), Random Layered Boron Nitride (t-BN); Hexagonal Carbon Boron Nitride (h-BCN); Transition Metal Dichalcogenide (MCh2, where) , M = Ti, Zr, Hf, V, Nb, Ta, Mo, W and other transition metals, at least one selected from Ch = S, Se, Te); Group 13 chalcogenides (GaS, GaSe, GaTe, InSe, etc.) ); Group 14 chalcogenides (GeS, SnS ₂ , SnSe ₂ , PbO, etc.); Bismas calcogenides (Bi ₂ Se ₃ , Bi ₂ Te ₃ ), natural or synthetic mica, talc, kaolin, pyrophyllite, etc. Examples include swellable clay minerals.
The layered material used in the present disclosure is preferably at least one selected from the group consisting of graphite, hexagonal boron nitride, hexagonal carbon boron nitride (h-BCN), and transition metal dichalcogenides. ..

The layered material contained in the layered material dispersion of the present disclosure is a piece of the layered substance, and contains at least one of a nanosheet in which the layered substance is monolayered and a piece in which the nanosheet is multi-layered, and is a thin piece. It is a layered material having an average thickness in the range of 100 nm or less. The layered material used in the present disclosure will be described in detail later.

In the layered material contained in the layered material dispersion of the present disclosure, the average surface spacing by the X-ray diffraction method is within the range of ± 0.01 nm of the average surface spacing of the layered material. For example, in the case of a fluorinated compound or a material in which a layered material is doped with hydrogen fluoride, the average surface spacing is much wider than that of the layered material before fluorination or hydrogen fluoride doping. Although the physical properties of the layered material laminate may be hindered, the layered material contained in the layered material dispersion of the present disclosure has almost no difference in average surface spacing from the layered material as a raw material, and the layered material is a single layer. It contains a fluorinated nanosheet and at least one of the multi-layered pieces of the nanosheet.
The layered material contained in the layered material dispersion of one embodiment of the present disclosure is a single-layered nanosheet or a multi-layered piece having an average surface area within the same range as that of the layered material, and has an average thickness of 100 nm or less. Therefore, it can be expected to be applied to special physical properties due to the two-dimensional structure and high specific surface area.

The layered material dispersion of one embodiment of the present disclosure contains 1 part by mass or more of an organic compound satisfying the following (i), (ii) and (iii) with respect to 1 part by mass of the layered material as described above. It is a layered material dispersion containing the following.
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.
The layered material dispersion of one embodiment of the present disclosure is formed by the organic compounds satisfying the above (i), (ii) and (iii), in which the separation between the flakes of the layered substance is promoted and dispersed. The organic compound satisfying the above (i), (ii) and (iii) prevents the layered material from reaggregating and stably maintains the dispersibility. On the other hand, unlike the ionic liquid, the organic compound satisfying the above (i), (ii) and (iii) does not strongly adsorb to the layered material. Therefore, in the layered material dispersion, it is easy to form a self-supporting film in which pieces of the layered material are laminated, and thin pieces of the layered material are directly adjacent to each other so as not to impair the special physical properties due to the two-dimensional structure of the layered material. A laminate can be formed. Further, the organic compounds satisfying the above (i), (ii) and (iii) can be volatilized by appropriately heating under reduced pressure. Therefore, the layered material dispersion has special physical properties due to the two-dimensional structure of the layered substance, for example, by appropriately heating it under reduced pressure as necessary after coating it on a non-porous substrate to remove the organic compound. It is possible to form a laminated body in which flakes of layered substances that do not impair the above are directly adjacent to each other. According to the layered material dispersion, a laminated body in which flakes of layered substances are directly adjacent to each other can be formed directly on the non-porous base material without using a porous base material, so that the layered material dispersion is non-porous. The adhesion of the laminate to the substrate can be improved, and even a non-porous substrate having irregularities on the surface can form the laminate by following the irregularities on the surface.
The characteristics due to the two-dimensional structure depend on the constituent atoms and atomic arrangement of the layered material used as a raw material, but for example, thermal conductivity, high insulation, conductivity, semiconductority, magnetism, strong dielectric property, and electroelectricity. Properties, photomagnetism, mechanical properties, electromagnetic wave absorption, electromagnetic wave reflectivity, non-linear optics, light absorption, light emission and the like can be mentioned.
According to the present disclosure, the layered materials can be laminated as flakes that are difficult to aggregate and easy to process to arbitrarily form a laminated body such as an integrated film, so that a layered material laminated body having excellent various physical properties can be obtained. be able to.

[Layered material]
The layered material of the present disclosure is a piece of a layered material, and the average surface spacing by the X-ray diffraction method is within the range of ± 0.01 nm of the average surface spacing of the layered material.
The layered material of the present disclosure is layered by combining the measurement of the average plane spacing and the crystal structure by the X-ray diffraction method, the identification of the contained elements by the fluorescent X-ray measurement, the identification of the organic substance inserted between layers by the infrared spectroscopic measurement, and the like. The substance can be identified.
The layered material of the present disclosure is one in which peeling between flakes of the layered material of the raw material is promoted, but has the same average surface spacing as the layered material of the raw material, and the average surface spacing by the X-ray diffractometry. Is within the range of ± 0.01 nm of the average surface spacing of the layered material.
For example, since the average interplanar spacing (d002) of graphite is usually 0.336 nm, when the layered material of the present disclosure is a piece of graphite, the average interplanar spacing (d002) is in the range of 0.326 nm or more and 0.346 nm or less. It is inside. Further, since the average interplanar spacing (d002) of the (002) plane of hexagonal boron nitride is usually 0.335 nm, when the layered material of the present disclosure is a piece of hexagonal boron nitride, the average interplanar spacing (d002) is used. Is in the range of 0.325 nm or more and 0.345 nm or less. Further, since the average interplanar spacing (d002) of the (002) plane of molybdenum disulfide is usually 0.616 nm, the average interplanar spacing (d002) is 0 when the layered material of the present disclosure is a piece of molybdenum disulfide. It is in the range of .606 nm or more and 0.626 nm or less.
For the layered material, using an X-ray diffractometer (powder X-ray diffraction, for example, manufactured by Rigaku Co., Ltd., model name: Miniflex II), from the diffraction pattern by CuKα ray (λ = 0.15418 nm), 2θ at the peak position. , And the average plane spacing: d can be calculated from Bragg's diffraction formula: λ = 2d · sinθ.

Each of the layered materials of the present disclosure has a thickness that is an integral multiple of the constituent unit layer thickness, and has an average thickness of about 0.3 nm or more and 100 nm or less. The average thickness of the layered material of the present disclosure is preferably 80 nm or less, more preferably 60 nm or less, still more preferably 50 nm or less.
The thickness of the layered material disclosed in the present disclosure refers to the maximum dimension of the layered material in the direction orthogonal to the surface of the layered material when viewed from the direction in which the area of the layered material is maximized.
The thickness of the layered material of the present disclosure can be measured using an atomic force microscope (AFM).
The average thickness of the layered material of the present disclosure can be obtained by measuring the thickness with AFM in a state where the layered material is independently dispersed on the substrate and calculating the average value of the measured values of the thickness of 200 layered materials. can.

More specifically, the average thickness can be obtained as follows.
The layered material dispersion is sampled, diluted 20 to 2000 times with a solvent to disperse the flakes without agglomeration, and then applied on a membrane filter having a pore size of 0.02 μm or less to separate the solvent and perform a membrane filter. The layered material is placed on top in an independent state without agglomeration. As the diluting solvent, a surfactant (for example, polyoxyethylene sorbitan monolaurate) is appropriately used in a solvent having a solubility of 5 (g / 100 g solvent) or more in the organic compound satisfying the above (i), (ii) and (iii). ) May be added (with respect to the solvent). The washed silicon wafer is pressed against the layered material arranged independently without being aggregated on the membrane filter, and the layered material is transferred onto the silicon wafer by peeling it off. The layered material adhering to the silicon wafer in an independently dispersed state is measured by AFM, and the thickness of the flakes is measured. For AFM measurement, the scanning range is set to 10 μm × 10 μm in the contact mode, that is, AFM (Atomic Force Microscope) using the function of the scanning probe microscope (SPM) in the nanosearch microscope SFT-3500 manufactured by Shimadzu Corporation. Measurements can be made. The difference in height between the silicon wafer and the layered material in the layered material adhering to the silicon wafer is defined as the thickness of the layered material. When the maximum diameter in the plane direction is larger than 10 μm, the scanning range can be set to 30 μm × 30 μm for measurement. Furthermore, when the maximum diameter in the plane direction is larger than 30 μm, the function of the confocal optical system is set to, for example, 640 × 480 μm by using the function of the laser microscope (SLM) in the nanosearch microscope SFT-3500 manufactured by Shimadzu Corporation. Can be used to measure the thickness of the layered material.
The average thickness of the layered material was measured by repeating the above operation until a total of 200 layered materials could be observed by AFM and / or SLM, and the thickness of 200 layered materials randomly selected was observed by AFM and / or SLM. It can be obtained by calculating the average value of the values.

In the layered material dispersion of the present disclosure, the content ratio of the layered material having a thin section thickness of 50 nm or less with respect to the entire layered material is preferably 10% by number or more, more preferably 50% by number or more, and further. It is preferably 70% by number or more. From the viewpoint of excellent characteristics due to the two-dimensional structure, the larger the content ratio of the layered material having a thickness of 50 nm or less to the entire layered material is, the more preferably 80% by number or more, and more preferably 90% by number or more. Is even more preferable. Above all, the content ratio of the layered material having a thickness of 0.3 nm or more and less than 10 nm with respect to the entire layered material is preferably 10% by number or more, and more preferably 20% by number or more.
The number% represents the ratio of the number of layered materials having a corresponding thickness to the total number of layered materials.

Further, the plane size of the layered material of the present disclosure refers to the size of the surface of the layered material when viewed from the direction in which the area of the layered material is maximized, and the maximum diameter is within the range of 0.05 μm or more and 100 μm or less. It is preferably in the range of 0.1 μm or more and 50 μm or less, and further preferably in the range of 0.5 μm or more and 50 μm or less. The plane size can be measured by direct observation with an optical microscope, an electron microscope, an atomic force microscope, or the like. The average maximum diameter can be determined by calculating the average value of the maximum diameters of 200 randomly selected layered materials measured by a microscope as well as the average thickness.

Each of the layered materials of the present disclosure preferably has an aspect ratio (maximum diameter / thickness) of 10 or more, and more preferably 50 or more. The average aspect ratio (average maximum diameter / average thickness) of the layered material of the present disclosure is preferably 10 or more, and more preferably 50 or more.

Further, the particle size distribution of the layered material in the layered material dispersion of the present disclosure can also be measured by a laser diffraction type particle size distribution measuring device.
The particle size distribution of the layered material in the layered material dispersion of the present disclosure by the laser diffraction type particle size distribution measuring device is 50% or less for less than 1 μm, 5% or more and 90% or less for 1 μm or more and 10 μm or less, and more than 10 μm. It is preferably 10% or more and 90% or less, and less than 1 μm is 30% or less, 1 μm or more and 10 μm or less is 10% or more and 85% or less, and 10 μm or more is 20% or more and 80% or less. Is more preferable.
Further, the average particle size (D50 median (median)) obtained as the average number distribution by the laser diffraction type particle size distribution measuring device of the layered material in the layered material dispersion of the present disclosure is obtained by laminating pieces of layered substances. From the viewpoint of easily forming a self-supporting film, it is preferably 0.1 μm or more and 500 μm or less, and more preferably 1 μm or more and 100 μm or less.
It is considered that the particle size of the layered material by the laser diffraction type particle size distribution measuring device generally represents the size in the plane direction, which is the maximum diameter of the layered material.
In the measurement of the particle size distribution by the laser diffraction type particle size distribution measuring device, the layered material dispersion is laser diffracted by using a solvent having a solubility of 5 (g / 100 g solvent) or more in the organic compound contained in the layered material dispersion. Dilute appropriately to a concentration that can be measured by the distribution measuring device, and measure at 25 ° C. using a laser diffraction type particle size distribution measuring device (for example, laser diffraction type particle size distribution measuring device SALD-2300 manufactured by Shimadzu Corporation). Can be done. As a guideline, the degree of dilution can be, for example, diluted so that the absorbance in a particle size distribution measuring cell having an optical path length of 6 mm shows 0.09. Further, as the refractive index of the dispersion, which is a parameter required for measuring the particle size distribution, the refractive index of the layered material in the dispersion can be used.

[Organic compound]
The organic compound used in the layered material dispersion of the present disclosure is an organic compound satisfying the following (i), (ii) and (iii).
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.
In the layered material dispersion of the present disclosure, by selecting an organic compound satisfying the above (i), (ii) and (iii) and using the layered material in combination at the time of dispersion, the layered material is layered in a relatively high-viscosity liquid. While the separation between the flakes of the substance is promoted, the layered material which is the flakes of the layered substance is dispersed, and the reaggregation of the layered material can be prevented and the dispersibility can be stably maintained. The organic compound satisfying the above (i), (ii) and (iii) is different from the ionic liquid because the SP value is 8 or more and 20 or less and the boiling point at 1 atm is 100 ° C. or more and 280 ° C. or less. It does not firmly adsorb to the layered material. Therefore, in the layered material dispersion, it is easy to form a self-supporting film in which pieces of the layered material are laminated, and thin pieces of the layered material are directly adjacent to each other so as not to impair the special physical properties due to the two-dimensional structure of the layered material. A laminate can be formed. Further, the organic compounds satisfying the above (i), (ii) and (iii) can be volatilized by appropriately heating under reduced pressure, if necessary. Therefore, the layered material dispersion is not only on the porous substrate, but also on the non-porous substrate by appropriately heating it under reduced pressure after coating it on the non-porous substrate to remove the organic compound. It is also possible to directly form a laminated body in which flakes of the layered material are directly adjacent to each other so as not to impair the special physical properties caused by the two-dimensional structure of the layered material.

The organic compound used in the layered material dispersion of the present disclosure has (i) an SP value of 8 or more and 20 or less, and the SP value is particularly high in terms of promoting exfoliation between flakes and dispersibility. It is preferably 10 or more, and preferably 16 or less.
Although there are several methods for measuring and calculating the SP value (solubility parameter), in the present disclosure, the method of Fedors [Fedors, R.I. F. , Polymer Eng. Sci. , 14, 147 (1974)]. In the Fedors method, the SP value is obtained by the atomic group contribution method. In the atomic group contribution method, the molecule is divided into several atomic groups, and empirical parameters are assigned to each atomic group to determine the physical properties of the entire molecule. It is a method to do.

The SP value δ of the molecule is defined by the following formula.
δ = (ΣΔei / ΣΔvi) ^1/2
δ: SP value ((cal / cm ³ ) ^1/2 )
Δei: Molar heat of vaporization of each atomic group (cal / mol)
Δvi: Molar volume of each atomic group (cm ³ / mol)

The molar heat of vaporization (Δei) and the molar volume (Δvi) of the constituent atomic group i are described in Table 5 (see FIGS. 2 and 3) of the literature (RF Fedors, POLYMER ENGINEERING AND SCIENCE, 14 (1974) 147-154). Use the values shown in.

The organic compound used in the layered material dispersion of the present disclosure has (ii) a melting point of 30 ° C. or lower and a viscosity of 30 ° C. of 10 mPa · s or more. The organic compound has a viscosity of 100,000 mPa · s or less at 30 ° C. because it promotes peeling between flakes of the layered substance in a relatively high-viscosity liquid and is easily dispersed in the organic compound. preferable. The organic compound preferably has a viscosity at 30 ° C. of 20 mPa · s or more and 10,000 mPa · s or less, and more preferably 30 mPa · s or more and 1,000 mPa · s or less.
Above all, it is preferable that the melting point is 28 ° C. or lower and the viscosity at 28 ° C. is 10 mPa · s or more, while it is preferably 100,000 mPa · s or less, and 20 mPa · s or more and 10,000 mPa · s. It is more preferably 30 mPa · s or more, and further preferably 1,000 mPa · s or less.
In the present disclosure, the viscosities at 30 ° C., 28 ° C., or 25 ° C. are measured according to ASTMD4440, respectively.

The organic compound used in the layered material dispersion of the present disclosure has a boiling point (iii) of 100 ° C. or higher and 280 ° C. or lower. If the boiling point at 1 atm is within this range, it can be volatilized by heating at a relatively low temperature by reducing the pressure as necessary. Therefore, as described above, the flakes of the layered material are directly formed not only on the porous base material but also directly on the non-porous base material so as not to impair the special physical properties due to the two-dimensional structure of the layered material. It is possible to form a laminated body adjacent to the above, and the laminated body can be directly formed on a non-porous base material having a relatively low heat resistance.

The organic compound used in the layered material dispersion of the present disclosure has a boiling point of 100 ° C. or higher and 280 ° C. or lower, which is different from that of an ionic liquid. Further, the organic compound used in the layered material dispersion of the present disclosure preferably does not form a salt, and preferably does not contain an organic cation.

Further, the organic compound used in the layered material dispersion of the present disclosure preferably contains at least one of an oxygen atom and a nitrogen atom from the viewpoint of promoting separation between flakes and dispersibility, and further, 1 It preferably contains at least one of a primary, secondary or tertiary amine structure, imine structure, and hydroxyl group.

Examples of the organic compound satisfying the above (i), (ii) and (iii) include 2,2'-iminodiethanol (SP value 14.9, melting point 28 ° C., viscosity at 30 ° C., 380 mPa · s, boiling point 268 ° C. ), 1,8-Diazabicyclo [5.4.0] -7-Undecene (DBU) (SP value 8.83, melting point -70 ° C, viscosity at 30 ° C, 30 mPa · s, boiling point 261 ° C), 1,1, Examples thereof include 3,3-tetramethylguanidine (TMG) (SP value 9.10, melting point -30 ° C, viscosity 20 mPa · s at 30 ° C, boiling point 163 ° C) and the like.

In the present disclosure, the organic compounds satisfying the above (i), (ii) and (iii) can be used alone or in combination of two or more.
In the present disclosure, the content ratio of the organic compound satisfying the above (i), (ii) and (iii) is such that the organic compound is contained in an amount of 1 part by mass or more with respect to 1 part by mass of the layered material. It is preferably contained in an amount of 2 parts by mass or more, and more preferably contained in an amount of 3 parts by mass or more because peeling of the layered material between the flakes easily proceeds during the production of the layered material dispersion. .. On the other hand, from the viewpoint of the efficiency of use of the organic compound, the content ratio of the organic compound is preferably 100 parts by mass or less, and 80 parts by mass or less with respect to 1 part by mass of the layered material. It is more preferable that the compound is 50 parts by mass or less, and it is further preferable that the compound is contained in an amount of 50 parts by mass or less.

Further, in the layered material dispersion of the present disclosure, the total content of the layered material and the organic compound is preferably 90% by mass or more, preferably 95% by mass, from the viewpoint that the effect of the present disclosure can be easily obtained. It is more preferably 98% by mass or more, and even more preferably 98% by mass or more.

[Other ingredients]
In addition to the layered material and the organic compound, the layered material dispersion of the present disclosure may further contain other components as long as the effects of the layered material dispersion of the present disclosure are not impaired. Examples of other components include solvents, resins, various additives and the like.
Examples of the additive used for the layered material dispersion include a plasticizer, an antifoaming agent, a silane coupling agent and the like.

The layered material dispersion of the present disclosure may further contain a solvent, for example, from the viewpoint of adjusting the viscosity. The solvent is preferably a good solvent for the organic compound, and is preferably a solvent having a solubility of the organic compound of 5 (g / 100 g solvent) or more. For example, when the melting point of the organic compound is 20 ° C. or higher and 30 ° C. or lower, by adding a small amount of solvent to the organic compound, stable production or storage at room temperature becomes possible.
In the layered material dispersion of the present disclosure, when a solvent is further contained, the content may be appropriately selected depending on the intended purpose, and is not particularly limited. Above all, during the production of the layered material dispersion, the peeling between the flakes of the layered material easily proceeds to produce the layered material in high yield, the layered material is difficult to reaggregate, and the dispersion stability is improved. The content ratio of the solvent is preferably less than 10 parts by mass, more preferably 5 parts by mass or less, and 2 parts by mass or less with respect to 10 parts by mass of the organic compound. It is even more preferable that the content is 1 part by mass or less.
Further, the content ratio of the solvent is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 2% by mass or less in the layered material dispersion.

The solvent may be appropriately selected depending on the organic compound, but like the organic compound, it is preferably volatilized by heating under reduced pressure as necessary, and has a boiling point of 300 ° C. or lower. It is preferably 280 ° C. or lower, more preferably lower than the boiling point of the organic compound, and even more preferably 50 ° C. or higher than the boiling point of the organic compound. Examples of the solvent include water, N-methylpyrrolidone (1-methyl-2-pyrrolidone), N, N-dimethylformamide, 1-butanol and the like.
In the present disclosure, the solvent may be used alone or in combination of two or more.

[Physical characteristics of layered material dispersion]
The viscosity of the layered material dispersion of the present disclosure may be appropriately selected depending on the intended purpose, and is not particularly limited. Above all, when the layered material dispersion is manufactured, the peeling between the flakes of the layered material easily proceeds to produce the layered material in good yield, the layered material is difficult to reaggregate, and the dispersion stability is improved. The viscosity of the layered material dispersion of the present disclosure at 25 ° C. is preferably 300 mPa · s or more, more preferably 3000 mPa · s or more, and even more preferably 10,000 mPa · s or more. On the other hand, from the viewpoint of ease of handling, the viscosity of the layered material dispersion of the present disclosure at 25 ° C. is preferably 100,000 mPa · s or less, and more preferably 80,000 mPa · s or less.
The layered material dispersion of the present disclosure is more preferably in the form of a so-called paste.

The layered material dispersion of the present disclosure can be produced, for example, by the following method for producing a layered material dispersion.
[Manufacturing method of layered material dispersion]
In the method for producing a layered material dispersion according to one embodiment of the present disclosure, one mass of an organic compound satisfying the following (i), (ii) and (iii) is added to one mass of a layered substance excluding swellable clay minerals. It has a step of adding parts or more and 100 parts by mass or less and kneading.
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.

In the present disclosure, the type of the layered substance as a raw material may be the same as the above-mentioned layered substance, and thus the description thereof is omitted here.
As the layered substance used as a raw material in the present disclosure, for example, a natural layered material, an artificial layered material, or the like can be appropriately selected.
As the layered substance used as a raw material in the present disclosure, it is preferable that the layered substance has a high purity, and it is preferable to use a layered substance having a purity of 80% or more.
The size of the layered substance used as a raw material is not particularly limited, and is selected according to the size of the layered material to be finally obtained.
The particle size of the layered substance before the dispersion treatment is not particularly limited as long as it can be dispersed, but usually, a maximum diameter of 100 μm or less is preferably used.

Further, the organic compound satisfying the above (i), (ii) and (iii) used in the present disclosure may be the same as the organic compound satisfying the above-mentioned (i), (ii) and (iii). The description here is omitted.
Further, the blending amount of the organic compound used in the present disclosure may be the same as the content ratio of the above-mentioned organic compound to the layered substance, and thus the description thereof is omitted here.

As the kneading method, any method can be appropriately selected as long as it is a method in which the layered substance and the organic compound are mixed and a shearing force is applied so that the layers of the layered substance can be dispersed while being separated from each other. Can be used.
As the device used for kneading, for example, a roll mill such as a two-roll or three-roll mill, a bead mill, a jet mill, an attritor, a Banbury mixer, a paint shaker, a kneader, a homogenizer, a uniaxial kneader, a biaxial kneader, etc. Can be mentioned.
It should be noted that the mixture may be mixed in advance using a mixing device before being subjected to the device used for kneading. Examples of such a mixing device include a mixer for high viscosity (planetary mixer, rotating / revolving mixer, locking mixer, etc.), a rotary stirrer with a stirring blade, a lab plast mill, and the like.

Since it is easy to form a self-supporting film in which pieces of layered substances are laminated using the layered material dispersion of the present disclosure, the number distribution average value of the layered material in the layered material dispersion by the laser diffraction type particle size distribution measuring device is used. It is possible to select an apparatus for kneading and kneading conditions so that the required average particle size (D50 median (median)) is 0.1 μm or more and 500 μm or less, and further 1 μm or more and 100 μm or less. preferable.

As the device used for kneading, it is preferable to select and use a method suitable for dispersing a liquid having a high viscosity, such as a method capable of applying a shearing force. Above all, it is preferable to knead with a roll mill such as a three-roll mill because it is easy to obtain a layered material having a relatively thin thickness and a large size in the plane direction. A layered material having a relatively thin thickness and a large size in the plane direction tends to form a self-supporting film when a laminated body is formed, and has high mechanical strength.
The rotation speed ratio of the roll mill may be appropriately adjusted according to the viscosity at the time of kneading, and is not particularly limited. For example, in the case of a three-roll mill, the rotation speed ratio of the first roll: the second roll: the third roll is , 1: (1.5 to 30): (2 to 100), and further 1: (2 to 20) :( 3 to 30).

In the kneading step, the viscosity of the liquid component containing the organic compound other than the layered substance as a raw material may be appropriately selected depending on the apparatus used for the kneading, and is not particularly limited. Above all, the viscosity of the liquid component containing the organic compound at 25 ° C. is 10 mPa · s or more from the point that peeling between the flakes of the layered substance easily proceeds to form a layered material and easily dispersed in the organic compound. It is preferably 10,000 mPa · s or less, more preferably 20 mPa · s or more and 10,000 mPa · s or less, and even more preferably 30 mPa · s or more and 1,000 mPa · s or less.

In the kneading step, a solvent may be added in order to adjust the viscosity of the liquid component containing the organic compound to be appropriate. The solvent is preferably a good solvent for the organic compound, and is preferably a solvent having a solubility of the organic compound of 5 (g / 100 g solvent) or more. Since such a solvent has been described above, the description thereof will be omitted here.
As described above, during the production of the layered material dispersion, the separation between the flakes of the layered material easily proceeds to produce the layered material in good yield, the layered material is difficult to reaggregate, and the dispersion stability is good. From this point of view, the content ratio of the solvent is preferably less than 10 parts by mass, more preferably 5 parts by mass or less, and 2 parts by mass with respect to 10 parts by mass of the organic compound. It is more preferably contained below, and even more preferably 1 part by mass or less. Further, the content ratio of the solvent is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 2% by mass or less in the layered material dispersion.

The layered material obtained by the method for producing a layered material dispersion is a single layered material, a ratio of the layered material having multiple layers in the range of 100 nm or less, and further, a layered material having multiple layers in the range of 50 nm or less. Due to the high proportion of material, it has properties due to its excellent two-dimensional structure without the need for classification treatment. Further, since the layered material that has not been sufficiently sliced does not remain, the mass of the layered material hardly decreases even after the classification treatment, and the layered material can be obtained with a high recovery rate.
When the method for producing a layered material dispersion is used, the ratio of the single layered material and the layered material having multiple layers in the range of 100 nm or less is 20% by mass or more, more preferably 50% by mass or more. It is possible to obtain a layered material in a yield of 70% by mass or more, more preferably 80% by mass or more, and a layered material in a yield of 90% by mass or more. It is also possible to obtain. Further, when the method for producing a layered material dispersion is used, the ratio of the single layered material and the layered material having multiple layers in the range of 50 nm or less is 20% by mass or more, more preferably 50. It is possible to obtain a layered material in a yield of mass% or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and a yield of 90% by mass or more. It is also possible to obtain a layered material with.

According to the method for producing a layered material dispersion, peeling between flakes of the layered material easily proceeds to form a layered material, and the layered material is difficult to reaggregate, so that the characteristics are caused by the two-dimensional structure. An excellent layered material can be obtained in high yield. Further, according to the method for producing a layered material dispersion of the present disclosure, as compared with the case where the layered material is peeled off by ultrasonic irradiation in a low-viscosity solvent of the prior art to produce a layered material dispersion, flakes are obtained. It is possible to provide a method for producing a layered material dispersion in which the residue of the layered material that is insufficiently formed is reduced. These actions are inferred as follows.
The layered material has a structure in which nanosheets having a two-dimensional structure are laminated in multiple layers. In the layered material, a van der Waals force is generated between each layer, and it is presumed that they are bonded with a relatively weak force.
On the other hand, the organic compound satisfying the above (i), (ii) and (iii) can be a highly viscous dispersion medium for the layered substance, but binds to the layered substance with a relatively weak force. It is a thing.
Therefore, by applying a high shearing force to the layered substance mixed with the liquid organic compound in a highly viscous state by kneading, the peeling between the flakes of the layered substance easily proceeds and the layered material is formed. In addition, since the peeled layered material is immediately bonded to the organic compound with a weak force and easily surrounded and dispersed, the peeled layered materials are suppressed from being immediately aggregated with each other. With respect to the peeled layered material, the peeling between the flakes is easily promoted by continuing kneading, so that a relatively thin layered material can be obtained in high yield.

The method for producing a layered material dispersion has at least the kneading step, and may further have another step as necessary within the range not impairing the effect of the present disclosure.
Such a step may further include, for example, a classification step for removing a layered material that has not been sufficiently sliced.
The classification step can be appropriately selected and used from conventionally known classification methods. On the other hand, the layered material obtained by the above-mentioned production method has almost no residual layered material that has not been sufficiently sliced. Therefore, the layered material of the present disclosure having excellent properties due to the two-dimensional structure without performing the classification step is performed. Can be obtained.
Further, even if there is a step of further adding a solvent in order to adjust the viscosity in order to produce a layered material laminate having characteristics due to an excellent two-dimensional structure after preparing the layered material dispersion. good.
Further, as another step, for example, a step of adding a resin or various additives may be included. The additives used for the layered material dispersion may be the same as described above.

[Use of layered material dispersion]
Since the layered material contained in the layered material dispersion of one embodiment of the present disclosure has excellent properties due to the two-dimensional structure, the layered material dispersion according to the present disclosure has the characteristics due to the excellent two-dimensional structure. It is excellent as a preparatory preparation for producing a material laminate.
Further, a resin or the like may be added to the layered material dispersion and used as a resin composition.

II. Method for Producing a Layered Material Laminate The method for producing a layered material laminate according to an embodiment of the present disclosure includes a step of forming or molding a layered material dispersion according to the present disclosure.
This is a method for manufacturing a layered material laminate, which is formed by laminating layered materials that are pieces of a layered substance.

The method for producing the layered material laminate using the layered material dispersion of one embodiment of the present disclosure can be appropriately selected from conventionally known film forming methods or molding methods.
Since the dispersion medium of the layered material dispersion of one embodiment of the present disclosure is the organic compound having a boiling point of 100 ° C. or higher and 280 ° C. or lower, as a method for forming a layered material laminate, glass, a resin film or the like can be used. A method can be used in which the layered material dispersion is applied onto the non-porous substrate and appropriately heated or depressurized to remove the liquid component containing the organic compound to form a film. According to this production method, a layered material laminate can be directly formed on a non-porous base material such as glass or a resin film. When the layered material laminate is directly formed on the non-porous substrate, the layered material laminate formed on the porous substrate is peeled off from the porous substrate and then on the non-porous substrate. The adhesion of the layered material laminate to the non-porous base material is higher than when it is attached to the non-porous base material, and the layered material laminate is formed with excellent adhesion regardless of the surface shape of the non-porous base material. There is a merit that it can be done. Further, according to the manufacturing method, the non-porous base material is not limited to a film or a sheet, and even if it is a molded body or a structure having a three-dimensional shape, a layered material laminate is formed along the surface thereof. There is a merit that it can be done.
Alternatively, as a method for forming a layered material laminate, a method of dropping the layered material dispersion onto a porous substrate such as a filter paper or a membrane filter and filtering it to remove liquid components to form a film can be mentioned. Be done. Further, as a method for forming the layered material laminate, for example, a method such as cast molding in which the layered material dispersion is placed in a porous mold and the liquid component is removed to form the layered material laminate can be mentioned. When removing the liquid component, the liquid component may be removed by appropriately heating or reducing the pressure.

The liquid component removed from the layered material dispersion of one embodiment of the present disclosure refers to a component that is liquid at the temperature of the removing step.
Examples of the liquid component include the organic compound contained in the layered material dispersion of one embodiment of the present disclosure, a solvent contained as necessary, and the like.

When the viscosity of the layered material dispersion of one embodiment of the present disclosure is high, a solvent is added and mixed before film formation or molding to reduce the viscosity of the layered material dispersion, and then film formation or molding is performed. May be. As the solvent to be added in this case, it is preferable that the solvent is a good solvent for the organic compound, and it is preferable that the solvent has a solubility of 5 (g / 100 g solvent) or more. Since such a solvent has been described above, the description thereof will be omitted here.

The viscosity of the layered material dispersion at the time of film formation or molding is set to 5000 mPa · s or less at 25 ° C. from the viewpoint that it is easy to form a film or mold uniformly and it is easy to appropriately remove the organic compound. It is preferably 1000 mPa · s or less, and more preferably 1000 mPa · s or less. A solvent may be appropriately added in order to keep the viscosity of the layered material dispersion at the time of film formation or molding within the above range. On the other hand, from the viewpoint of suppressing aggregation of the layered material due to over-dilution, the viscosity of the layered material dispersion at the time of film formation or molding is preferably 100 mPa · s or more at 25 ° C., and 200 mPa · s or more. It is more preferably 300 mPa · s or more, and even more preferably 300 mPa · s or more.
According to the method of the present disclosure, the organic compound can be appropriately removed by heating while reducing the pressure as necessary, so that the layered material laminate having excellent properties due to the two-dimensional structure is obtained. Suitable for.
If a solvent is added and mixed before the liquid component is removed to sufficiently lower the viscosity and then left to stand, the dispersion stability of the layered material may deteriorate. Therefore, when a solvent is added and mixed before film formation or molding, the time from the addition of the solvent and mixing before film formation or molding to the film formation or molding is within 24 hours. It is preferably within 6 hours.

The layered material laminate formed on the non-porous base material may be used as it is for the intended purpose, or may be peeled off from the non-porous base material and used as a single body, or transferred to another base material or the like. May be used.
Alternatively, the layered material laminate obtained by using the porous base material or the liquid permeable mold may be peeled off from the porous base material or the liquid permeable mold and used as a single body, or may be a glass base material or a glass base material. It may be transferred to another substrate such as a resin substrate and used.

Further, it is preferable to compress the layered material laminate by applying pressure using a press machine, a roll press machine, or the like. By such a compression treatment, bubbles can be removed, the porosity can be reduced, the mechanical strength can be increased, and the characteristics due to the two-dimensional structure of the layered substance can be enhanced. Even if the organic compound is present between the layered materials of the layered material laminate, the compression treatment partially moves the organic compound between the layered materials and increases the contact interface between some of the layered materials. Therefore, the characteristics due to the two-dimensional structure of the layered material are enhanced.
The pressure in the pressurizing step may be appropriately adjusted and is not particularly limited. For example, in the case of a roll press, the linear pressure is preferably 50 N / mm or more, and further 100 N / mm or more. It is preferable to have. Further, in the case of a surface press, the pressure is preferably 10 MPa or more, and more preferably 40 MPa or more.

Further, after the step of forming or forming a film, the layered material laminate may be washed with a solvent that dissolves the organic compound. When the organic compound can be easily removed by washing with a solvent that dissolves the organic compound and a layered material laminate having higher purity can be obtained, the layered material laminate having excellent properties due to the two-dimensional structure can be obtained. Can be a body. As the solvent for dissolving the dispersant, it is preferable to select and use a solvent having a solubility of the organic compound of 5 (g / 100 g solvent) or more and further 10 (g / 100 g solvent) or more.
Above all, it is preferable to perform the cleaning step after the compression treatment step rather than before the compression treatment step from the viewpoint of obtaining a self-supporting film having high mechanical strength.

III. Layered material laminate The layered material laminate of one embodiment of the present disclosure is a piece of a layered material excluding swellable clay minerals, and is formed by laminating layered materials having an average thickness of 100 nm or less, and is subjected to X-ray diffraction. A layered material laminate having an average surface spacing within the range of ± 0.01 nm of the average surface spacing of the layered material.
It contains 0.1% by mass or more and 5% by mass or less of an organic compound satisfying the following (i), (ii) and (iii), and has an elastic modulus of 3 GPa or more in a tensile test based on JIS-K7127 (1999). , Layered material laminate.
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.

As described above, the layered material according to the present disclosure has an average thickness of 100 nm or less and is excellent in characteristics due to the two-dimensional structure. Further, by containing the organic compound which is not strongly adsorbed on the layered material in a specific amount, aggregation of the layered material is suppressed as compared with the case where the layered material is completely removed, and an aggregate of granules in which the layered material is partially aggregated is suppressed. This is suppressed, the independence of the laminated body of the layered material is improved, a flexible integrated film is produced, the mechanical strength is improved, and the physical properties of the layered material are not adversely affected. Further, the average surface spacing of the layered material laminate by the X-ray diffraction method is within the range of ± 0.01 nm of the average surface spacing of the layered material. From these facts, the layered material laminate of one embodiment of the present disclosure has excellent mechanical strength and has excellent properties due to the two-dimensional structure of the layered material.
The layered material contained in the layered material laminate of one embodiment of the present disclosure may be the same as the layered material contained in the above-mentioned layered material dispersion, and thus the description thereof is omitted here.

The shape of the layered material laminate according to the present disclosure is not limited as long as it is a laminate formed by laminating the layered materials according to the present disclosure. In the layered material laminate according to the present disclosure, at least a part of each of the layered materials of the present disclosure may be laminated so as to overlap each other.
Further, the layered material laminate according to the present disclosure may be one in which at least a part of each of the layered materials of the present disclosure is in contact with each other. In the layered material laminate according to the present disclosure, each of the layered materials of the present disclosure may be in contact with each other on the side surfaces in the thickness direction.

The layered material laminate according to the present disclosure may be in the form of a film or a sheet, or may be a molded body having a three-dimensional structure.
When the layered material laminate according to the present disclosure is in the form of a film or a sheet, the thickness is not particularly limited. From the viewpoint of providing flexibility, when the layered material laminate according to the present disclosure is in the form of a film or a sheet, the thickness is preferably 1 mm or less, and more preferably 200 μm or less.
Further, since the layered material laminate according to the present disclosure is formed by laminating the layered materials according to the present disclosure, it is possible to follow an adherend having a curved surface or a lot of irregularities.

In the layered material laminate according to the present disclosure, the direction in which at least a part of each of the layered materials of the present disclosure is overlapped with each other and laminated is usually the thickness direction of the flakes.
Also in the layered material laminate according to the present disclosure, the average surface spacing by the X-ray diffraction method is within the range of ± 0.01 nm of the average surface spacing of the layered material, as in the layered material of the present disclosure.

The layered material laminate according to the present disclosure is a laminate in which the layered materials contained in the layered material dispersion according to the present disclosure are laminated, but a part of the layered material constituting the laminate has a thin piece thickness. A layered material exceeding 100 nm may be contained.

The layered material laminate according to the present disclosure contains 0.1% by mass or more and 5% by mass or less of an organic compound satisfying the above (i), (ii) and (iii), and among them, the specific organic substance. The compound is preferably contained in an amount of 4% by mass or less, more preferably 3% by mass or less, and even more preferably 2% by mass or less. Further, the layered material laminate according to the present disclosure may contain 0.2% by mass or more of the specific organic compound.
The content ratio of the organic compound is determined, for example, by raising the temperature of the layered material laminate from room temperature to 90 ° C. in a nitrogen atmosphere using a thermogravimetric analyzer, holding the layered material laminate at 90 ° C. for 30 minutes, and then raising the temperature. It can be calculated by heating from 90 ° C. to 280 ° C. at 10 ° C./min and performing thermogravimetric analysis to confirm the mass reduction of the compound not derived from the layered material. Further, the structure of the organic compound satisfying the above (i), (ii) and (iii) to be contained is confirmed, and the content ratio of the organic compound in the layered material laminate containing the organic compound and the organic solvent is further determined by the layered material. It can be determined by performing TOF-SIMS analysis of the laminate or by performing analysis of NMR, IR, LC-MS, GC-MS, etc. after extracting the organic component from the layered material laminate as appropriate. ..

Further, the layered material laminate according to the present disclosure has a tensile elastic modulus of 3 GPa or more in accordance with JIS-K7127 (1999) from the viewpoint of mechanical strength. That is, in the tensile test of the sheet shape according to JIS-K7127 (1999) of the layered material laminate according to the present disclosure, the elastic modulus is preferably 3 GPa or more. From the viewpoint of mechanical strength, the tensile elastic modulus is more preferably 4 GPa or more.
The tensile modulus of elastic modulus of the layered material laminate according to JIS-K7127 (1999) according to the present disclosure is 5 mm in width using a tensile tester (for example, manufactured by Shimadzu Corporation: Autograph AG-X 1N, load cell: SBL-1KN). × A test piece having a length of 30 mm can be cut out and measured at 25 ° C. with a tensile speed of 0.05 mm / min and a distance between chucks of 20 mm. The layered material laminate for determining the tensile elastic modulus is in the form of a film or a sheet, and the thickness is preferably 10 μm or more and 2 mm or less, more preferably 1 mm or less, and further preferably 200 μm or less. It is preferable that the surface direction is 5 mm × 30 mm or more.

Further, the layered material laminate according to the present disclosure preferably has a low porosity because it has excellent characteristics due to the two-dimensional structure of the layered material. It is preferable to compress the layered material laminate as necessary so as to satisfy the following preferable porosity.
The porosity of the layered material laminate is preferably 30% or less, more preferably 20% or less, further preferably 15% or less, still more preferably 10% or less.
Here, the porosity can be calculated from the true density (ρT) peculiar to each layered material and the density (ρ1) of the layered material laminate from the following formula.
Porosity = (ρT-ρ1) / ρT x 100 [%]

Further, the layered material laminate according to the present disclosure preferably has a thermal diffusivity of 1 × 10 ^-6 m ² / s or more, preferably 2 × 10 ^-6 m ² / s or more, from the viewpoint of heat dissipation performance. It is more preferably 1 × 10 ^-5 m ² / s or more.
When the thermal diffusivity of the layered material laminate according to the present disclosure is anisotropic, the thermal diffusivity shall mean the maximum value of the layered material laminate according to the present disclosure.
When the thermal conductivity of the layered material is anisotropic, the thermal diffusivity of the layered material laminate according to the present disclosure is also anisotropic. In such a case, since the thermal conductivity in the plane direction, which is the unit layer direction of the layered material, is usually large, the layered material laminate also often refers to the thermal diffusivity in the plane direction.
The heat diffusion rate of the layered material laminate according to the present disclosure can be measured by a periodic heating radiation temperature measurement method using a thermophysical property measuring device (for example, Thermo Wave Analyzer TA3 manufactured by Bethel Co., Ltd.).

Further, the layered material laminate according to the present disclosure preferably has a conductivity of 500 S / cm or more, more preferably 800 S / cm or more, and more preferably 1000 S / cm or more, from the viewpoint of conductivity. Is even more preferable.
When the conductivity of the layered material laminate according to the present disclosure is anisotropic, the conductivity means the maximum value of the layered material laminate according to the present disclosure.
When the conductivity of the layered material is anisotropic, the conductivity of the layered material laminate according to the present disclosure is also anisotropic. In such a case, since the conductivity in the plane direction, which is the unit layer direction of the layered substance, is usually increased, the layered material laminate also often refers to the conductivity in the plane direction.
The conductivity (σ) of the layered material laminate according to the present disclosure can be calculated from σ = 1 / (ρs × t) from the surface resistance value (ρs) and the thickness (t) of the layered material laminate. The surface resistance value (ρs) can be measured by a resistance meter using a 4-probe method (manufactured by Mitsubishi Chemical Analytec Co., Ltd., model name: Loresta GP MCP-T610), and the thickness of the layered material laminate ( t) can be measured by a high-precision digital length measuring machine (manufactured by Mitutoyo Corporation, model name: Lightmatic VL-50SB). A method for measuring resistivity, which is the reciprocal of conductivity (σ), is also described in JIS-K7194.

Further, from the viewpoint of mechanical strength, the layered material laminate according to the present disclosure has a mandrel diameter of 5 mm at which cracks occur in a bending resistance test by a cylindrical mandrel method based on JIS-K5600-5-1 (1999). It is preferably less than or equal to, and more preferably 4 mm or less. The layered material laminate used for the bending resistance test is preferably in the form of a film or a sheet, which is the same as when the tensile elastic modulus is obtained.

Further, the layered material laminate according to the present disclosure preferably does not contain other components such as a binder because it has excellent properties due to the two-dimensional structure of the layered material, and is layered in the layered material laminate. The content ratio of the material is preferably 95% by weight or more, more preferably 96% by weight or more, further preferably 97% by weight or more, and preferably 99.9% by weight or less. It is more preferably 99.8% by weight or less, and even more preferably 99.7% by weight or less.
The content ratio is, for example, the layered material laminate is dried in an oven at 90 ° C. to remove volatile components such as residual solvent, and then the temperature is raised from room temperature to 280 ° C. under a thermogravimetric analyzer using a thermogravimetric analyzer. After holding at 280 ° C. for 30 minutes, the layered material was heated from 280 ° C. to 800 ° C. at a heating rate of 10 ° C./min and subjected to thermogravimetric analysis to confirm the mass reduction of the layered material, although it was not derived from the layered material. The content ratio can be determined.
Whether or not the layered material laminate according to the present disclosure further contains an inorganic component such as an inorganic binder in addition to the layered material can be confirmed by TOF-SIMS analysis. When other inorganic components are further contained, the content ratio of the other inorganic components in the layered material laminate is determined by TOF-SIMS analysis to determine the count number of the plurality of components corresponding to the layered materials. It can be obtained from the ratio of the total value of to the total count number.

The average thickness of the layered materials contained in the layered material laminate of the present disclosure can be obtained from a micrograph of a cross section of the layered material laminate, and the 200 layered materials found in the cross section of the layered material laminate can be obtained. It can be obtained by calculating the average value of the measured values of the thickness.

More specifically, the average thickness can be obtained as follows.
After immersing the layered material laminate in liquid nitrogen, divide it in two. Observe the cracked cross section with a scanning electron microscope. As the scanning electron microscope, for example, SU8020 manufactured by Hitachi High-Technologies Corporation is used, and when the display size is 345 mm × 259 mm, the electron microscope photograph is taken at a magnification of 10,000 to 200,000 times. By repeating the cross-section photography until a total of 200 thicknesses of the layered materials constituting the layered material laminate can be observed, the length of each thickness of the 200 pieces shown in the micrograph is measured, and the average value is calculated. The average thickness of the layered materials constituting the layered material laminate can be obtained.

The layered material laminate of the present disclosure can be produced, for example, by the above-mentioned method for producing a layered material laminate.

Since the layered material dispersion and the layered material laminate according to the present disclosure are excellent in various properties due to the two-dimensional structure of each layered substance, the layered material, the layered material dispersion liquid, and the layered material according to the present disclosure are excellent. Laminates are used in various fields such as nanoelectronics, nanocomposites, transparent conductive films, electrodes, batteries, capacitors, hydrogen storage, energy storage, biological applications, heat dissipation sheets, aerospace industry, sensors, and transistors. Can be suitably applied to the above applications.

Hereinafter, the present disclosure will be specifically described with reference to examples. These statements do not limit this disclosure. Further, unless otherwise specified, the test was carried out at 25 ° C.
[Evaluation methods]

<Viscosity>
The viscosity was measured at a shear rate of 1 (1 / sec) using a viscosity / viscoelasticity measuring device: MARS3 manufactured by Thermohaque, which was attached to a temperature controller, according to ASTMD4440.

<Measurement of average surface spacing by X-ray diffraction method>
2θ at the peak position from the diffraction pattern by CuKα ray (λ = 0.15418 nm) using XRD (powder X-ray diffraction manufactured by Rigaku Co., Ltd., model name: Miniflex II) for the layered material or the layered material laminate. Was specified, and the average surface spacing: d was calculated from Bragg's diffraction formula: λ = 2d · sinθ.
Among the following examples, the average plane spacing (d002) was measured for hexagonal boron nitride and graphite. Normally, the average interplanar spacing (d002) of hexagonal boron nitride is 0.335 nm.
In addition, the average interplanar spacing (d002) of graphite is usually 0.336 nm.

<Measurement of average thickness of layered material>
A layered material dispersion and a mixed solution containing the layered material dispersion were sampled, and a surfactant (Tween 20 manufactured by Wako Pure Chemical Industries, Ltd.) was added to a solvent having a solubility of 5 (g / 100 g solvent) or more in the organic compound used. After diluting 20 to 2000 times with an aqueous solution containing 2% (relative to water) of ethylene sorbitan monolaurate, the solvent is separated by filtration on a membrane filter with a pore size of 0.02 μm. The flakes were placed in an independent state without agglomeration. Further, the surfactant was removed by washing with a solvent having a solubility of 5 (g / 100 g solvent) or more, and the layered material was placed on the surface. In this state, the washed silicon wafer was pressed onto the membrane filter and peeled off to transfer the layered material onto the silicon wafer. The layered material adhering to the silicon wafer in an independently dispersed state was measured by AFM. For AFM measurement, the scanning range is 10 μm × in the contact mode, that is, AFM (Atomic Force Microscope), using the function of the scanning probe microscope (SPM) in the nanosearch microscope SFT-3500 manufactured by Shimadzu Corporation. When the maximum diameter in the plane direction is 10 μm or larger than 10 μm, the scanning range is set to 30 μm × 30 μm, and the difference in height between the silicon wafer and the layered material in the layered material adhering on the silicon wafer is the difference between the heights of the layered materials. The thickness of each slice was measured as the thickness. Furthermore, when the maximum diameter in the plane direction was larger than 30 μm, the scanning range was 640 × 480 μm using the function of the laser microscope (SLM) in the nanosearch microscope SFT-3500 manufactured by Shimadzu Corporation. Then, the thickness of the layered material was measured using the function of the cofocal optical system.
The average thickness of the layered material was determined by repeating the above operation until a total of 200 layered materials could be observed by AFM and SLM, and the measured values of the thickness of 200 layered materials randomly selected were observed by AFM and SLM. It can be obtained by calculating the average value.

<Measurement of particle size distribution of layered material dispersion by laser diffraction type particle size distribution measuring device>
The obtained layered material dispersion is diluted with a solvent having a solubility of 5 (g / 100 g solvent) or more of the organic compound so as to show an absorbance of 0.09 in a particle size distribution measuring cell having an optical path length of 6 mm, and laser diffraction is performed. The particle size distribution of the layered material dispersion was measured at 25 ° C. using a formula particle size distribution measuring device (manufactured by Shimadzu Corporation, laser diffraction type particle size distribution measuring device SALD-2300). The refractive index of the dispersion, which is a parameter required for measuring the particle size distribution, is 2.3 + 0.02i (0.02i is an imaginary part) in the case of boron nitride, and 1.95-0.2i in the case of graphite. Was measured using.

<Observation of layered material laminate with scanning electron microscope>
After immersing the layered material laminate in liquid nitrogen, it was divided into two, and the cracked cross section was observed with a scanning electron microscope. As a scanning electron microscope, SU8020 manufactured by Hitachi High-Technologies Corporation was used, and when the display size was 345 mm × 259 mm, the electron microscope photograph was taken at a magnification of 10,000 to 200,000 times. By repeating the cross-section photography until a total of 200 thicknesses of the layered materials constituting the layered material laminate can be observed, the length of each thickness of the 200 pieces shown in the micrograph is measured, and the average value is calculated. The average thickness of the layered materials constituting the layered material laminate was determined.

<Porosity>
The density (ρ1) of the obtained layered material laminate is obtained by cutting the layered laminate into a rectangular parallelepiped, measuring the length and width with a ruler, and measuring the thickness with a high-precision digital length measuring machine ((((). The volume was calculated by measuring with Mitutoyo Co., Ltd. Lightmatic VL-50S-B), the weight was measured with a precision balance, and the volume was calculated by weight ÷ volume.
The true density (ρT) peculiar to layered materials is the theoretical density of layered materials identified by measuring the average surface spacing by X-ray diffraction method, and is an inorganic material database provided by the National Institute for Materials Science. It can be obtained by referring to "Atom Work" or "SciFinder" which is a database provided by the Japan Association for International Chemical Information.
The porosity can be calculated from the true density (ρT) peculiar to each layered material and the density (ρ1) of the layered material laminate from the following formula.
Porosity = (ρT-ρ1) / ρT x 100 [%]

<Tension modulus>
The tensile modulus of elastic modulus of the layered material laminate according to JIS-K7127 (1999) is 5 mm wide x 30 mm long using a tensile tester (for example, Shimadzu: Autograph AG-X 1N, load cell: SBL-1KN). The test piece was cut out and measured at 25 ° C. with a tensile speed of 0.05 mm / min and a distance between chucks of 20 mm.

<Thermal diffusivity>
The thermal diffusivity was measured using the Thermo Wave Analyzer TA3 (periodic heating radiation temperature measurement method) of Bethel Co., Ltd.
Specifically, the layered material laminate to be measured was placed on the sample table of the device, the thickness measured in advance was input, and the device was operated to measure the thermal diffusivity.

<Conductivity>
The conductivity (σ) of the layered material laminate was calculated from σ = 1 / (ρs × t) from the surface resistance value (ρs) and the thickness (t) of the layered material laminate. The surface resistance value (ρs) is measured by a resistance meter using a 4-probe method (manufactured by Mitsubishi Chemical Analytec Co., Ltd., model name: Loresta GP MCP-T610), and the thickness (t) of the layered material laminate is high. It was measured by an accuracy digital length measuring machine (manufactured by Mitutoyo Corporation, model name: Lightmatic VL-50SB).

<Organic compound content>
After removing volatile components such as residual solvent by drying the layered material laminate in an oven at 90 ° C, the temperature is raised from room temperature to 90 ° C under a thermogravimetric analyzer and held at 90 ° C for 30 minutes. After that, it is contained in the obtained layered material laminate by heating from 100 ° C. to 280 ° C. at a heating rate of 10 ° C./min and performing thermogravimetric analysis to confirm the mass reduction of a substance not derived from the layered material. The content ratio of the layered material and the organic compound was determined.

(Example 1)
(1) Production of layered material and layered material dispersion 0.5 g of graphite (manufactured by Nippon Graphite Co., Ltd., trade name: ACB-50) and 2,2'-iminodiethanol (manufactured by Wako Pure Chemical Industries, Ltd .; SP value 14. 9. Mix 2.0 g of a water-containing material (water content 4.6% by mass, viscosity 360 mPa · s at 25 ° C.) having a melting point of 27 ° C. and a viscosity of 30 ° C. of 380 mPa · s and a boiling point of 269 ° C., and roll mill ( Made by IMEX Co., Ltd., model number: BR-100V, roll material: zirconia, three roll rotation ratio "1: 2.4: 6"), and the fastest rotating roll speed is 60 at 300 rpm. By the fractionation treatment, a layered material dispersion 1 in which the layered material 1 was dispersed was obtained. The viscosity of the layered material dispersion 1 at 25 ° C. was 21000 mPa · s. Even if the layered material dispersion 1 was allowed to stand for 24 hours, the layered material 1 did not precipitate.

A small amount of sample was taken from the layered material dispersion 1, and a surfactant (Tween 20 (polyoxyethylene sorbitan) manufactured by Wako Pure Chemical Industries, Ltd.) was added to water, which is a solvent having a solubility of 2,2'-iminodiethanol of 5 (g / 100 g solvent) or more. After diluting with an aqueous solution containing 2% (to water) of monolaurate), a membrane filter with a pore size of 0.02 micron (GE Healthcare Japan, Annodisk, material: alumina, unless otherwise stated) When the liquid component was filtered out in the same manner and the average surface spacing (d002) of the (002) plane of the layered material 1 was measured by the X-ray diffraction method, it showed 0.336 nm, which was the same as ACB-50 of the raw material graphite. ..

Further, when the average thickness (d) of the constituent layered materials was calculated by observing the layered materials with a laser microscope (SLM) and an atomic force microscope, the average thickness was determined to be 45 nm.
FIG. 1 shows one of the laser micrographs of the layered material 1 constituting the layered material dispersion 1.

Further, when the particle size distribution of the layered material dispersion 1 was measured using a dispersion liquid diluted with water so that the absorbance was 0.09 in a particle size distribution measuring cell having an optical path length of 6 mm, the number distribution was less than 1 μm. Was 5%%, 1 μm or more and 10 μm or less was 80%, 10 μm excess was 15%, and the average median diameter (D50) was 8 μm.

(2) Production of Layered Material Laminate A 1-methyl-2-pyrrolidone was added to the layered material dispersion 1 obtained in (1) so that the viscosity became 500 mPa · s. The layered material dispersion immediately after the viscosity adjustment was applied onto a polyimide film substrate using an applicator, and then in a glass tube oven (GTO-3000, manufactured by Shibata Kagaku Co., Ltd.) under reduced pressure using an oil rotary vacuum pump. It was dried at 280 ° C. for 2 hours, and further compressed using a roll press machine (SA-602, manufactured by Tester Sangyo Co., Ltd.) under the conditions of a load of 20 kN (linear pressure 120 N / mm) and a roll rotation speed of 1 m / min. A layered material laminate 1 having a thickness of 33 μm was obtained.

The porosity of the obtained layered material laminate 1 was 9%.
Further, the layered material laminate 1 had an elastic modulus of 3.9 GPa in a tensile test of a sheet shape conforming to JIS-K7127 (1999).
The conductivity of the layered material laminate 1 was 1300 S / cm.
The average plane spacing (d002) of the (002) plane was measured for the layered material laminate 1 by the X-ray diffraction method. The average interplanar spacing (d002) of the layered material laminate 1 was calculated to be 0.336 nm, which was the same as ACB-50 of the raw material graphite.
By scanning microscope observation of the cross section of the layered material laminate 1 after the compression treatment, the average thickness of the constituent layered materials was observed to be 45 nm.
Further, the layered material laminate 1 contained 0.3% by mass of the organic compound.

(Example 2)
(1) Manufacture of layered material and layered material dispersion Hexagonal boron nitride (manufactured by Denka Co., Ltd., trade name: Denkaboron nitride powder XGP) 0.5 g and 2,2'-iminodiethanol (manufactured by Wako Pure Chemical Industries, Ltd .; Mix 2.0 g of water-containing material (water content 4.6% by mass, viscosity 360 mPa · s at 25 ° C) with SP value 14.9, viscosity 27 ° C, viscosity 380 mPa · s at 30 ° C, boiling point 269 ° C). However, with a roll mill (manufactured by IMEX Co., Ltd., model number: BR-100V, roll material: zirconia, three roll rotation ratio "1: 2.4: 6"), the speed of the fastest rotating roll is 300 rpm. The layered material dispersion 2 in which the layered material 2 was dispersed was obtained by the treatment in the above state for 60 minutes. The viscosity of the layered material dispersion 2 at 25 ° C. was 27,000 mPa · s. Even if the layered material dispersion 2 was allowed to stand for 24 hours, the layered material 2 did not precipitate.

A small amount of sample was sampled from the layered material dispersion 2, and a surfactant (Tween 20 (polyoxyethylene sorbitan) manufactured by Wako Pure Chemical Industries, Ltd.) was added to water, which is a solvent having a solubility of 2,2'-iminodiethanol of 5 (g / 100 g solvent) or more. After diluting with an aqueous solution containing 2% (to water) of monolaurate), a membrane filter with a pore size of 0.02 micron (GE Healthcare Japan, Annodisk, material: alumina, unless otherwise stated) The liquid component was filtered out in the same manner (same as above), and the average surface spacing (d002) of the (002) plane of the layered material 2 was measured by the X-ray diffraction method. It showed 335 nm.

Further, when the average thickness (d) of the constituent layered materials was calculated by observing the layered materials with an atomic force microscope, the average thickness was determined to be 61 nm.

Furthermore, when the particle size distribution of the layered material dispersion 2 was measured using a dispersion liquid diluted with water so that the absorbance was 0.09 in a particle size distribution measuring cell having an optical path length of 6 mm, the number distribution was less than 1 μm. Was 2%%, 1 μm or more and 10 μm or less was 35 pieces%, and 10 μm excess was 63 pieces%, and the average median diameter (D50) was 23 μm.

(2) Production of Layered Material Laminate A 1-methyl-2-pyrrolidone was added to the layered material dispersion 2 obtained in (1) so that the viscosity became 500 mPa · s. The layered material dispersion immediately after the viscosity adjustment was applied onto a polyimide film substrate using an applicator, and then in a glass tube oven (GTO-3000, manufactured by Shibata Kagaku Co., Ltd.) under reduced pressure using an oil rotary vacuum pump. It was dried at 280 ° C. for 2 hours, and further compressed using a roll press machine (SA-602, manufactured by Tester Sangyo Co., Ltd.) under the conditions of a load of 20 kN (linear pressure 120 N / mm) and a roll rotation speed of 1 m / min. A layered material laminate 2 having a thickness of 24 μm was obtained.

The porosity of the obtained layered material laminate 2 was 12%.
Further, the obtained layered material laminate 2 had an elastic modulus of 3.2 GPa in a tensile test of a sheet shape according to JIS-K7127 (1999).
The thermal diffusivity of the obtained layered material laminate 2 was 3.1 × 10 ^-5 m ² / s (stainless steel: SUS304 had a thermal diffusivity of 4.1 × 10 ^-6 m ² / s). ..

The average plane spacing (d002) of the (002) plane was measured for the layered material laminate 2 by the X-ray diffraction method. The peak of the layered material laminate 2 was located at 2θ = 26.64 °, and the average interplanar spacing (d002) was calculated to be 0.335 nm, which was similar to that of the raw material boron nitride dencabolon nitride powder XGP.
By scanning microscope observation of the cross section of the obtained layered material laminate 2, the average thickness of the constituent layered materials was observed to be 60 nm.
Further, the layered material laminate 2 contained 0.4% by mass of the organic compound.

(Example 3)
(1) Production of layered material and layered material dispersion Graphite (manufactured by Nippon Graphite Co., Ltd., trade name: ACB-50) 0.5 g and DBU (1,8-diazabicyclo [5.4.0] -7-undecene) ( Made by Tokyo Chemical Industry Co., Ltd .; SP value 8.83, melting point -70 ° C, viscosity at 30 ° C 30 mPa · s, boiling point 261 ° C) 2.0 g was mixed and rolled mill (manufactured by Imex Co., Ltd., model number: BR- Layered material 3 is dispersed by processing for 60 minutes at 100 V, roll material: zirconia, three roll rotation ratio "1: 2.4: 6") at a speed of the fastest rotating roll of 300 rpm. The layered material dispersion 3 was obtained. The viscosity of the layered material dispersion 3 at 25 ° C. was 22000 mPa · s. Even if the layered material dispersion 3 was allowed to stand for 24 hours, the layered material 3 did not precipitate.

A small amount was sampled from the layered material dispersion 3, and a surfactant (Tween 20 (polyoxyethylene sorbitan monolaurate) manufactured by Wako Pure Chemical Industries, Ltd.) was added to acetone, which is a solvent having a DBU solubility of 5 (g / 100 g solvent) or more. % (With respect to solvent) After diluting with the added solution, use a membrane filter with a pore size of 0.02 micron (GE Healthcare Japan Co., Ltd., Annodisk, material: alumina, the same applies hereinafter unless otherwise specified). When the layered material 3 was separated by filtration and the average surface spacing (d002) of the (002) plane was measured by the X-ray diffraction method, it showed 0.336 nm, which was the same as ACB-50 of the raw material graphite.
Further, when the average thickness (d) of the constituent layered materials was calculated by observing the layered materials with an atomic force microscope, the average thickness was determined to be 60 nm.

Furthermore, when the particle size distribution of the layered material dispersion 3 was measured using a dispersion liquid diluted with water so that the absorbance was 0.09 in a particle size distribution measuring cell having an optical path length of 6 mm, the number distribution was less than 1 μm. Was 10% by number, 1 μm or more and 10 μm or less was 85 number%, and 10 μm excess was 15 number%, and the average median diameter (D50) was 7 μm.

(2) Production of Layered Material Laminate A 1-methyl-2-pyrrolidone was added to the layered material dispersion 3 obtained in (1) so that the viscosity became 500 mPa · s. The layered material dispersion immediately after the viscosity adjustment was applied onto a polyimide film substrate using an applicator, and then in a glass tube oven (GTO-3000, manufactured by Shibata Kagaku Co., Ltd.) under reduced pressure using an oil rotary vacuum pump. It was dried at 280 ° C. for 2 hours, and further compressed using a roll press machine (SA-602, manufactured by Tester Sangyo Co., Ltd.) under the conditions of a load of 20 kN (linear pressure 120 N / mm) and a roll rotation speed of 1 m / min. A layered material laminate 3 having a thickness of 35 μm was obtained.

The porosity of the obtained layered material laminate 3 was 11%.
Further, the layered material laminate 3 had an elastic modulus of 3.7 GPa in a tensile test of a sheet shape conforming to JIS-K7127 (1999).
The conductivity of the layered material laminate 3 was 1200 S / cm.
The average plane spacing (d002) of the (002) plane was measured for the layered material laminate 3 by the X-ray diffraction method. The average interplanar spacing (d002) of the layered material laminate 3 was calculated to be 0.336 nm, which was the same as ACB-50 of the raw material graphite.
By scanning microscope observation of the cross section of the layered material laminate 3 after the compression treatment, the average thickness of the constituent layered materials was observed to be 60 nm.
Further, the layered material laminate 3 contained 0.4% by mass of the organic compound.

(Comparative Example 1)
(1) Manufacture of layered material and layered material dispersion 0.5 g of graphite (manufactured by Nippon Graphite Co., Ltd., trade name: ACB-50) and 1-methyl-2-pyrrolidone (manufactured by Wako Pure Chemical Industries, Ltd .; SP value 10.6) , Melting point -24 ° C, viscosity at 25 ° C 1.7 mPa · s, boiling point 202 ° C) 2.0 g, roll mill (manufactured by IMEX Co., Ltd., model number: BR-100V, roll material: zirconia, three pieces At the roll rotation ratio "1: 2.4: 6"), the treatment was performed for 60 minutes at a state where the speed of the fastest rotating roll was 300 rpm, but the comparative layered material dispersion 1 in which the comparative layered material 1 was dispersed was treated for 24 hours. When allowed to stand, all the comparative layered material 1 was precipitated, and the supernatant was transparent. This condition indicates that a layered material that has not been sufficiently thinned remains. The viscosity of the supernatant of the comparative layered material dispersion 1 at 25 ° C. was 2 mPa · s. Further, the comparative layered material dispersion 1 obtained immediately after the treatment with the roll mill was applied onto the polyimide film substrate using an applicator, and then oil-rotated in a glass tube oven (GTO-3000, manufactured by Shibata Kagaku Co., Ltd.). Dry under reduced pressure using a vacuum pump at 280 ° C. for 2 hours, and then use a roll press machine (SA-602, manufactured by Tester Sangyo Co., Ltd.) to load 20 kN (wire pressure 120 N / mm) and roll rotation speed 1 m / min. When the compression treatment was carried out under the above conditions, a powdery comparative layered material 1 was obtained without forming a film. Since the layered material that has not been sufficiently sliced remains, it is presumed that the laminated body of the layered material has become powdery rather than filmy.

Claims (5)

It is a piece of layered material excluding swellable clay minerals having a swelling force of 5 mL / 2 g or more, and the average surface spacing by X-ray diffraction is within the range of ± 0.01 nm of the average surface spacing of the layered material, and is average. 1 part by mass or less of an organic compound satisfying the following (i), (ii) and (iii) is contained in 1 part by mass of a layered material having a thickness of 100 nm or less.
A layered material dispersion having a total content of the layered material and the organic compound of 90% by mass or more .
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower. The layered material dispersion according to claim 1, which has a viscosity at 25 ° C. of 300 mPa · s or more. Add 1 part by mass or more and 100 parts by mass or less of the organic compound satisfying the following (i), (ii) and (iii) to 1 part by mass of the layered substance excluding the swellable clay mineral having a swelling power of 5 mL / 2 g or more. Has a kneading process
A method for producing a layered material dispersion, wherein the total content of the layered material and the organic compound is 90% by mass or more .
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower. The step of forming or molding the layered material dispersion according to claim 1 or 2 .
A method for manufacturing a layered material laminate, which is formed by laminating layered materials that are pieces of a layered substance. A piece of layered material excluding swellable clay minerals with a swelling power of 5 mL / 2 g or more, layered materials having an average thickness of 100 nm or less are laminated, and the average surface spacing by X-ray diffraction method is that of the layered material. A layered material laminate with an average surface spacing within ± 0.01 nm.
It contains 0.1% by mass or more and 5% by mass or less of an organic compound satisfying the following (i), (ii) and (iii), and has an elastic modulus of 3 GPa or more in a tensile test based on JIS-K7127 (1999). , Layered material laminate.
(I) The SP value is 8 or more and 20 or less.
(Ii) The melting point is 30 ° C. or lower, and the viscosity at 30 ° C. is 10 mPa · s or more.
(Iii) The boiling point is 100 ° C. or higher and 280 ° C. or lower.

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