SnS dispersion and method for producing the same

Abstract

[Problem] To provide: an SnS particle dispersion liquid which has fine dispersibility and in which precipitates do not appear when being preserved; a method for producing the same; and an SnS particle production method. [Solution] This SnS dispersion liquid has SnS particles dispersed in a water-based or alcohol-based dispersion liquid. In the SnS dispersion liquid, the average major axis of the dispersed SnS particles is 100-2000 nm, the average minor axis of the SnS particles is 50-1000 nm, and the average aspect ratio (major axis / minor axis) is 1.2-1.6. This method for producing an SnS dispersion liquid comprises: a vapor deposition step for heating an SnS raw material housed in an evaporation source container and capturing SnS in a capturing container; an isolation step for separating an obtained vapor deposition product from the capturing container to obtain SnS particles; and a dispersion step for dispersing the vapor deposition product obtained in the isolation step in a water-based dispersion liquid. In the vapor deposition step, the heating temperature of the evaporation source container is 700-900°C, and the maximum capturing container temperature of the capturing container is 80-130°C.

Description

[Technical Field]

[0001] The present invention relates to an SnS dispersion and a method for producing the same, and more particularly to an SnS dispersion and SnS particles that have good dispersibility and do not precipitate during storage, as well as methods for producing SnS particles and an SnS dispersion. [Background technology]

[0002] Metal sulfides have attracted attention in various fields, such as the energy-related field and the lubricant field, and stannous sulfide (SnS) has particularly attracted attention due to its excellent properties. For this reason, various metal sulfides containing stannous sulfide with adjusted particle size and methods for producing the same have been proposed. For example, Patent Document 1 proposes a method for producing a tin sulfide film with crystals oriented in a specific direction by a vacuum plating method. Specifically, a tin sulfide film is formed on the surface of a substrate by vacuum plating at a vacuum degree of 133.3 × 10 -4 ~13.3×10 -7A method for producing a tin sulfide film has been proposed, in which a tin sulfide film is formed at a pressure in the range of Pa, by controlling the substrate temperature to a range of 120 to 400°C and the film formation rate to a range of 0.05 to 0.5 μm / min, thereby orienting the tin sulfide film crystals in a specific direction. Patent Document 2 proposes a method for producing tin sulfide that is industrially simple and safe, preventing contamination of the reaction system by unreacted sulfur without using special equipment such as high-pressure equipment or harmful substances such as mercury. Specifically, a method for producing tin sulfide has been proposed, in which a workpiece containing metallic tin and sulfur, in which the molar ratio of the sulfur content to the metallic tin content (S / Sn) is 1 to 4, is subjected to mechanochemical treatment to react the metallic tin with the sulfur to obtain tin sulfide. Patent Document 3 proposes a method for producing a powder containing stannous sulfide that is energy-efficient, efficient, and capable of continuous production. Specifically, the proposed method includes a charging step of introducing into a mill powder or lumps of tin and sulfur, in which the ratio of the number of sulfur atoms to the number of tin atoms (S / Sn) is 0.95 or more and 1.50 or less, and a processing step of operating the mill to mechanically activate the tin and sulfur, causing a chain synthesis reaction due to the heat of the synthesis reaction of tin and sulfur, wherein the charging step is carried out at a temperature lower than the melting point of sulfur. Patent Document 4 proposes a production method for obtaining a high-purity chalcogenide compound of Group 14 elements and Group 16 elements in a ratio of about 1:1, which has been difficult to obtain in the past. Specifically, the proposed method involves a process for producing a high-purity chalcogenide compound of Group 14 elements and Group 16 elements in a ratio of about 1:1, which has the general formula: M 1 M 2 x [In the formula, M 1 indicates an element in Group 14 of the periodic table. 2 represents an element of Group 16 of the periodic table. x represents 0.9 to 1.1.], and the amount of the chalcogenide compound present is 90 mol % or more in X-ray diffraction measurement, and a method for producing the same has been proposed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-144044 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-120607 [Patent Document 3] Japanese Patent Application Publication No. 2018-5278 [Patent Document 4] WO2020 / 013191 publication Summary of the Invention [Problem to be solved by the invention]

[0004] However, the tin sulfides proposed above and the tin sulfides obtained by the manufacturing methods have not yet been able to achieve the required performance. The present inventors have conducted extensive research into the reasons why the previously proposed tin sulfides are unable to achieve the desired performance, and have found that one of the reasons is that the tin sulfides have poor dispersibility in the dispersion liquid, which is the state before use. In other words, obtaining tin sulfides with good dispersibility is important for achieving the desired performance, and a tin sulfide dispersion with good dispersibility that does not precipitate during storage is needed.

[0005] Therefore, an object of the present invention is to provide a dispersion of SnS particles that has good dispersibility and does not precipitate during storage, a method for producing SnS particles and an SnS dispersion, and a method for producing SnS particles. [Means for solving the problem]

[0006] As a result of extensive research aimed at solving the above problems, the present inventors discovered that the above object could be achieved by dispersing SnS particles in a dispersion produced by a vapor deposition process under specific temperature conditions, leading to the completion of the present invention. Specifically, the present invention provides the following: 1. An SnS dispersion in which SnS particles are dispersed in an aqueous or alcoholic dispersion, wherein the dispersed SnS particles have an average major axis of 100 to 2000 nm, an average minor axis of 50 to 1000 nm, and an average aspect ratio (major axis / minor axis) of 1.2 to 1.6. 2. The SnS dispersion according to 1, wherein the concentration of the SnS particles in the aqueous dispersion is 0.0001 to 50 mass%. 3. The SnS dispersion according to 1, wherein the SnS particles have an average thickness of 100 to 1,000 nm and a particle size distribution (based on scattering intensity, D50) of 100 to 700 nm. 4. The SnS dispersion according to 1, wherein the SnS purity measured by XRD of dried SnS particles is 90 mass % or more. 5. The SnS particles have a specific surface area of ​​5 m2 measured by BET measurement. 2 6. The SnS dispersion according to 1, wherein the mass absorption coefficient (0.001 mass%) is 15,000 cm at a wavelength of 600 nm. -1 The SnS dispersion according to 1, wherein the SnS particles are extracted from the SnS dispersion according to 1, and the average major axis of the SnS particles is 100 to 2000 nm, the average minor axis of the SnS particles is 50 to 1000 nm, and the average aspect ratio (major axis / minor axis) is 1.2 to 1.6. 8. The SnS particles according to 7, wherein the average thickness of the SnS particles is 100 to 1000 nm, and the particle size distribution (scattering intensity basis, D50) of the SnS particles is in the range of 100 to 700 nm. 9. The SnS particles according to 7, wherein the SnS purity measured by XRD of the dried SnS particles is 90 mass % or more. 10. The SnS particles have a specific surface area of ​​5 m2 measured by BET measurement. 2 8. The SnS particles according to 7, wherein the SnS particle has a molecular weight of 1 / g or more. 11. SnS particles according to 7, which are mixed particles of SnS and acetylene black, further containing acetylene black in addition to SnS. 12. A method for producing SnS particles, comprising: a vapor deposition step of heating a SnS raw material contained in an evaporation source container to capture SnS in a capture container; and an isolation step of separating the resulting vapor from the capture container to obtain SnS particles, wherein the evaporation source container is heated to a temperature of 700 to 900°C in the vapor deposition step and the maximum capture container temperature of the capture container is 80 to 130°C. 13. A method for producing SnS particles according to 12, wherein the average capture rate in the vapor deposition step is 20 mg / min or more. 14. A method for producing an SnS dispersion according to 14.1, comprising a vapor deposition step of heating an SnS raw material contained in an evaporation source container to capture SnS in a capture container, an isolation step of separating the resulting vapor from the capture container to obtain SnS particles, and a dispersion step of dispersing the vapor obtained in the isolation step in an aqueous or alcohol-based dispersion, wherein the evaporation source container is heated to a temperature of 700 to 900°C in the vapor deposition step and the capture container has a maximum temperature of 80 to 130°C. 15. A method for producing an SnS dispersion according to 14, wherein the dispersion step comprises an ultrasonic dispersion step of performing ultrasonic dispersion at an amplitude of 50 to 150 μm. [Effects of the Invention]

[0007] The SnS dispersion of the present invention has good dispersibility and does not precipitate during storage. The SnS particles of the present invention constitute the above-mentioned SnS dispersion of the present invention and can exhibit excellent properties. Furthermore, according to the method for producing the SnS dispersion of the present invention, a dispersion of SnS particles having good dispersibility and not precipitating during storage can be produced. According to the method for producing SnS particles of the present invention, SnS particles constituting the above-mentioned SnS dispersion, which can exhibit excellent properties, can be obtained. The SnS particles obtained from the SnS dispersion of the present invention can exhibit excellent properties and are therefore useful as raw materials in fields such as energy-related and lubricants. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing a vapor deposition apparatus for carrying out the vapor deposition step in the method for producing an SnS dispersion of the present invention. [Figure 2]FIG. 2 is an SEM photograph (a photograph substituting for a drawing) showing the particle state of SnS particles dispersed in the SnS dispersion liquid obtained in Example 1. [Figure 3] FIG. 3 is an SEM photograph (a photograph substituting for a drawing) showing the particle state of SnS particles dispersed in the SnS dispersion liquid obtained in Example 2. [Figure 4] FIG. 4 is an SEM photograph (a photograph substituting for a drawing) showing the particle state of SnS particles dispersed in the SnS dispersion liquid obtained in Example 3. [Figure 5] FIG. 5 is a photograph in lieu of a drawing showing the dispersion state of the SnS dispersion, in which (a) shows the initial state of the SnS dispersion obtained in Example 1, (b) shows the state of the SnS dispersion obtained in Example 1 after 17 hours, (c) shows the initial state of the SnS dispersion obtained in Example 2, (d) shows the state of the SnS dispersion obtained in Example 2 after 17 hours, (e) shows the initial state of the SnS dispersion obtained in Example 3, (f) shows the state of the SnS dispersion obtained in Example 3 after 17 hours, (g) shows the initial state of the SnS dispersion obtained in the comparative example, and (h) shows the state of the SnS dispersion obtained in the comparative example after 17 hours. [Figure 6] FIG. 6 is an SEM photograph (a photograph substituting for a drawing) showing the particle state of SnS particles dispersed in the SnS dispersion liquid obtained in the comparative example. [Figure 7] FIG. 7 is a chart showing the results of XRD measurement of the SnS particles obtained in the examples and comparative examples. [Figure 8]FIG. 8 is a photograph substituting for a drawing showing the dispersion state of the SnS dispersion. (a) shows the initial state of the SnS dispersion obtained in Example 4, (b) shows the initial state of the SnS dispersion obtained in Example 5, (c) shows the initial state of the SnS dispersion obtained in Example 6, (d) shows the initial state of the SnS·acetylene black dispersion obtained in Example 7, (e) shows the tin sulfide·acetylene black mixed particles obtained in Example 7, (f) shows the initial state of the dispersion obtained by redispersing the particles obtained in Example 7 in water, (g) shows the initial state of the SnS·acetylene black dispersion obtained in Example 8, (h) shows the tin sulfide·acetylene black mixed particles obtained in Example 9, and (i) shows the initial state of the dispersion obtained by redispersing the particles obtained in Example 8 in water. [Figure 9] FIG. 9 is a chart showing the particle size distribution of the SnS particles or SnS·acetylene black particles obtained in Examples 4 to 8. [Figure 10] FIGS. 10(a) to (d) are SEM photographs (photographs substituting for drawings) showing the particle states of the SnS·acetylene black particles dispersed in the SnS dispersions obtained in Examples 7 to 8, respectively.

Mode for Carrying Out the Invention

[0009] Hereinafter, the present invention will be described in more detail. <SnS Dispersion and SnS Particles> The SnS dispersion of the present invention is an SnS dispersion in which SnS particles are dispersed in water or an alcohol-based dispersion, and the average particle diameter (average of the major diameters) and the average aspect ratio (major diameter / minor diameter) of the dispersed SnS particles are within specific ranges. Further, the SnS particles of the present invention are obtained from the SnS dispersion of the present invention, and the average particle diameter (average of the major diameters) and the average aspect ratio (major diameter / minor diameter) are within specific ranges. The SnS particles of the present invention are extracted (taken out) from the SnS particles constituting the above-described SnS dispersion and dried, but

[0010] [SnS Particles (SnS Particles of the Present Invention)] In the present invention, the SnS particles (SnS particles of the present invention) dispersed in the SnS dispersion have an average major axis of 100 to 2,000 nm, preferably 100 to 500 nm, and most preferably 100 to 200 nm. The average minor axis is 50 to 1,000 nm, preferably 50 to 200 nm, and most preferably 50 to 150 nm. The average aspect ratio (major axis / minor axis) is 1.2 to 1.6. While the measurement methods for these are described in detail in the Examples, all measurements can be performed using an SnS dispersion. In other words, the SnS particles of the present invention are particles whose average major axis, average minor axis, and average aspect ratio measured in the SnS dispersion fall within the above-mentioned ranges. By having the average major axis, the average minor axis, and the average aspect ratio within the above ranges, it is believed that dispersibility in a dispersion is improved, and in turn, various performance characteristics of the SnS particles themselves are improved to the required level. The average major axis refers to the average diameter of the longest part of the particle, and the average minor axis refers to the average diameter of the shortest part of the particle. The average thickness of the SnS particles is preferably 100 to 1,000 nm, more preferably 100 to 300 nm. The particle size distribution (based on scattering intensity, D10) of the SnS particles is preferably in the range of 100 to 200 nm. The particle size distribution (based on scattering intensity, D50) of the SnS particles is preferably in the range of 100 to 700 nm, more preferably 200 to 500 nm. The particle size distribution (based on scattering intensity, D90) of the SnS particles is preferably in the range of 500 to 1,500 nm. By having the average thickness and the particle size distribution (particularly D50) within the above ranges, the dispersibility is further improved, and the required performance is further improved. The specific surface area of ​​the SnS particles is measured by the BET method. 2 / g or more is preferable from the viewpoint of improving dispersibility, and 5 to 20m 2 / g, more preferably 8 to 15m 2 / g is most preferable. The SnS particles of the present invention can be obtained by drying SnS particles dispersed in an SnS dispersion. The purity of the dried SnS particles obtained varies depending on the purity of the raw materials used, but the SnS purity measured by XRD is preferably 90% by mass or more, and more preferably 95 to 100% by mass. This purity can be achieved by the production method described below, which allows for the production of a dispersion containing particles with better dispersibility and desired properties. The method for determining the SnS purity by XRD measurement will be described in detail in the Examples. Here, "dried" refers to a state in which the moisture content of the SnS particles extracted from the dispersion has been removed, usually to a state in which the moisture content is 0.1% by mass or less. The moisture content can be measured using conventional methods without particular limitations. The drying method can be performed using conventional methods without particular limitations, but drying can also be performed using a vacuum dryer under reduced pressure at 50 to 100°C for 1 to 10 hours. In particular, SnS particles having an average major axis of preferably 100 to 500 nm, more preferably 100 to 200 nm, an average minor axis of preferably 50 to 200 nm, most preferably 50 to 150 nm, and an average aspect ratio (major axis / minor axis) of 1.2 to 1.6 are considered to have excellent dispersibility and to be useful as materials in various fields. Furthermore, SnS particles having an average thickness of 100 to 300 nm and a particle size distribution (based on scattering intensity, D50) of 200 to 500 nm are particularly preferred. Such SnS particles can be obtained by extracting SnS particles from an SnS dispersion obtained through an ultrasonic dispersion step in the production method described below and drying them in a manner similar to the drying method described above. In this sense, when a method for producing an SnS dispersion includes an ultrasonic dispersion step, the method for producing the SnS dispersion can be considered to be a method for producing SnS particles. The SnS particles of the present invention may also contain other particles. Examples of such other particles include acetylene black, carbon nanotubes, graphene, graphene oxide, graphite, silicon, silicon oxide, and silicon carbide. The term "contained" here refers not only to a state in which the SnS particles and other particles are simply dispersed and mixed, but also to a state in which the particles are aggregated together and the aggregates are further aggregated, or to a state in which the particles are aggregated together. In this case, the blending ratio of the other particles is preferably 99-70% SnS:1-30% other particles (weight ratio, total amount 100).

[0011] [Aqueous Dispersion] The aqueous dispersion used in the SnS dispersion of the present invention can be water or a mixture of water and a water-soluble organic solvent. The organic solvent can be alcohols such as ethanol, isopropanol (IPA), and methanol, and the blending ratio is not particularly limited. [Alcohol-Based Dispersion] The alcohol-based dispersion used in the SnS dispersion of the present invention can be ethanol, isopropanol (IPA), methanol, or the like.

[0012] [SnS Dispersion] The concentration of the SnS particles (including those containing other particles) in the aqueous dispersion is preferably 0.0001 to 50% by mass, more preferably 0.0001 to 25% by mass, even more preferably 0.001 to 20% by mass, and most preferably 0.01 to 10% by mass. A concentration below this range may make it difficult to obtain the properties of the SnS particles, while a concentration above this range is undesirable because it may result in reduced dispersibility, resulting in particle aggregation and reduced particle performance. The absorbance of the dispersion is preferably 0.15 or more at a wavelength of 600 nm and preferably 0.1 or more at a wavelength of 1250 nm. The transmittance is preferably 70% or less at a wavelength of 600 nm. The mass extinction coefficient of the dispersion (0.001% by mass) is 15,000 cm at a wavelength of 600 nm. -1 It is preferable that the temperature is 50,000 to 80,000 cm or more. -1It is more preferable. The above absorbance, the above transmittance, and the above mass absorption coefficient are all at an SnS particle concentration of 0.001% by mass, and it is preferable from the viewpoint of improving dispersibility that they are within the above ranges. The measurement method is as described in the examples. Incidentally, at an SnS particle concentration of 5% by mass, the absorbance is preferably 1 or more at a wavelength of 600 nm, and preferably 0.8 or more at a wavelength of 1250 nm. The transmittance is preferably 5 or less at a wavelength of 600 nm. The mass absorption coefficient is preferably 25 cm -1 or more, and more preferably 50 to 80 cm -1 It is more preferable.

[0013] <Method for Producing SnS Dispersion Liquid and Method for Producing SnS Particles> Next, the method for producing the SnS dispersion liquid and SnS particles of the present invention described above will be explained. The method for producing SnS particles of the present invention can be carried out by performing a vapor deposition step of heating an SnS raw material contained in an evaporation source container and capturing SnS in a capture container, and an isolation step of separating the obtained vapor deposition product from the capture container to obtain SnS particles. By this production method, SnS particles constituting the SnS dispersion liquid of the present invention described above can be obtained. Among the SnS particles of the present invention described above, particularly preferable SnS particles can be obtained by drying the obtained SnS dispersion liquid after performing the following method for producing an SnS dispersion liquid and extracting (taking out) SnS particles from the SnS dispersion liquid. Further, the method for producing an SnS dispersion liquid of the present invention is a method for producing the SnS dispersion liquid of the present invention described above, and includes a vapor deposition step of heating an SnS raw material contained in an evaporation source container and capturing SnS in a capture container, an isolation step of separating the obtained vapor deposition product from the capture container to obtain SnS particles, and a dispersion step of dispersing the vapor deposition product obtained in the isolation step in an aqueous dispersion liquid. In the method for producing SnS particles and the method for producing an SnS dispersion liquid, the vapor deposition step and the isolation step are common. In other words, it can be said that the method for producing an SnS dispersion liquid can be carried out by further performing the above dispersion step on the method for producing SnS particles. Therefore, the following description of the method for producing SnS particles is also applicable to the method for producing an SnS dispersion liquid.

[0014] [Raw Material] The SnS raw material used in the present invention is not particularly limited in purity as long as it is a bulk SnS raw material, but a raw material with a purity of 90% or more is preferably used.

[0015] [Vapor Deposition Process] The vapor deposition process is a process in which the SnS raw material contained in an evaporation source container is heated to capture SnS in a capture container, and can be performed using a vapor deposition apparatus shown in FIG. 1. The vapor deposition apparatus 1 shown in FIG. 1 includes a chamber 10 that can be sealed and evacuated, a heater 20 installed in the chamber 10, an evaporation source container 30, and a capture container 40. The evaporation source container 30 is configured to house an evaporation source therein, and a thermometer (not shown) is installed in the evaporation source container 30 so that the temperature can be measured. The evaporation source container 30 can also be heated by the heater 20. The capture container 40 is installed a predetermined distance away from the evaporation source container 30, and a thermometer (not shown) is installed so that the temperature can be measured. The heater, evaporation source container, and capture container can be any of those typically used in this type of vapor deposition apparatus, without any particular limitations. For example, the capture container may be made of glass such as borosilicate glass or metal such as alumina, as long as it is heat-resistant and does not denature the SnS particles being deposited. Although not shown, the chamber 10 is connected to a vacuum pump to reduce pressure and create a vacuum, and is also equipped with a valve for returning the reduced pressure to normal pressure. A typical thermocouple or the like can be used as the thermometer (not shown). The temperature measurement point is not particularly limited, but it is preferable to measure the temperature near the side of the evaporation source container to reduce the influence of the heater, and for the capture container, it is preferable to measure the temperature on the back side of the capture surface for the same reason. During the deposition process, the heating temperature of the evaporation source container 30 (measured by the thermometer) is 700 to 900°C, and the maximum capture container temperature of the capture container 40 (maximum temperature measured by the temperature detector) is 80 to 130°C. If these temperatures are outside these ranges, the SnS dispersion of the present invention cannot be prepared. The capture vessel 40 is installed at a predetermined distance from the evaporation source vessel 30. This distance is important for adjusting the maximum capture vessel temperature of the capture vessel 40, and needs to be changed depending on the size of the chamber 10, the amount of SnS raw material, etc., but the maximum capture vessel temperature can be adjusted by adjusting this distance. In the deposition process, an average capture rate of 20 mg / min or more is preferred in order to obtain a better quality dispersion.The deposition process is completed when the SnS raw material, which is the evaporation source, is exhausted from the evaporation source container 30. The pressure during the process is 5 Pa to 1×10. -5 It is preferable to maintain Pa.

[0016] [Isolation Step] The isolation step is a step of separating the resulting deposition product from the capture container to obtain SnS particles. Specifically, this can be performed by mechanically peeling and collecting the SnS particles in the capture container 40. This peeling and collection can be performed using any conventional method that can be used to produce particles by vapor deposition and then isolate and collect them. This step can also be used to isolate and collect the SnS particles attached to the capture container by repairing them in a volatile solvent such as ethanol. Obtaining an ethanol dispersion in this manner reduces the loss of SnS particles due to scattering during collection. When mechanically peeling and collecting the SnS particles, the resulting particles can be used as is. When repairing them using a volatile solvent, the volatile solvent can be removed and the SnS particles can be dried to obtain SnS particles. Alternatively, an SnS dispersion can be obtained by performing the dispersion step described below.

[0017] [Dispersion Step] The dispersion step is a necessary step for carrying out the method for producing the SnS dispersion of the present invention. The SnS particles obtained as a vapor in the isolation step are added to the aqueous or alcohol-based dispersion, and the SnS particles are dispersed by a conventional method to obtain the SnS dispersion of the present invention. Furthermore, in the dispersion step of the present invention, an ultrasonic dispersion step can be further carried out, in which ultrasonic dispersion is performed preferably at an amplitude of 50 to 150 μm, more preferably 100 to 130 μm. The ultrasonic dispersion step can be carried out using an ultrasonic device commonly used for dispersion, such as an ultrasonic homogenizer, and the frequency can be any, but can be 20 Hz to 60 Hz. By performing the ultrasonic dispersion step with an amplitude within the above range, an SnS dispersion with better dispersibility can be obtained. Furthermore, to obtain an SnS dispersion containing the above-mentioned other particles, the obtained SnS dispersion can be further mixed with other particles, such as acetylene black particles, and the above-mentioned dispersion (and optionally, an ultrasonic dispersion step) can be further carried out to obtain an SnS dispersion containing the other particles. In this case, the SnS particles obtained when the particles are extracted will contain other particles.

[0018] [Other Steps] In the present invention, in addition to the above-described vapor deposition step, isolation step, and dispersion step, other steps may be performed within the scope of the present invention. For example, since the SnS particles of the present invention are obtained by extracting (taking out) SnS particles constituting an SnS dispersion, a drying step must be performed to dry the SnS dispersion to obtain SnS particles. This drying step can be performed, for example, using a vacuum dryer at 50 to 100°C under reduced pressure for 1 to 10 hours, although the temperature and time may vary depending on the amount of SnS particles to be dried. [Example]

[0019] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. [Example 1] The above-mentioned deposition process was carried out using the deposition apparatus shown in Figure 1. 13 g of bulk tin sulfide (purity: about 98%) was placed as a raw material in the deposition source container 30. The distance between the deposition source container 30 and the capture container 40 was set to 12.3 cm. Next, a vacuum pump was used to reduce the pressure in the chamber to 5 x 10 -4 The evaporation source vessel was evacuated to a temperature of the order of 100 Pa, and the temperature of the evaporation source vessel was raised to 900°C by a heater, and heated at 900°C for 4 hours. The maximum temperature of the capture vessel 40 was 101°C. The pressure during the treatment was 5×10 -3 Pa~1×10 -4 The average capture rate measured using the above-described measurement method was 46.7 mg / min. Next, the isolation and dispersion processes were performed. First, the capture container 40 was removed from the vacuum chamber 1, and ethanol was poured into the capture container 40. SnS (hereinafter also referred to as "tin sulfide") was peeled off from the glass container to obtain a tin sulfide ethanol solution. The ethanol was removed from the resulting tin sulfide ethanol solution. The isolation process was carried out by drying the tin sulfide ethanol solution under reduced pressure in a vacuum dryer (drying temperature: 70°C for 4 hours). Pure water was added to 0.4 g of the dried tin sulfide, and the mixture was stirred using a conventional stirring method (stirring), to obtain 8 g of a 5% by mass tin sulfide aqueous solution (SnS dispersion of the present invention). The SnS particles in the resulting dispersion were dried to obtain SnS particles. The resulting tin sulfide was used to perform the following tests. A photograph of the particle shape is shown in FIG. 2, the XRD results are shown in FIG. 7, and other results are shown in Table 1.

[0020] A precipitation test was conducted using the obtained SnS dispersion. The storage container was thoroughly stirred by hand before the precipitation test began. The precipitation test was conducted by checking the precipitation state at the start and after 17 hours. The results are shown in Figures 3(a) and 3(b). The following measurements were also conducted using the obtained SnS dispersion. The results are shown in Table 1. Particle size distribution and zeta potential measurements: The solvent used was the same as that of the SnS dispersion, pure water, and the SnS dispersion was diluted to 0.001% by mass. Measurements were also conducted using the obtained SnS dispersion (concentration: 5% by mass) as is. Particle size distribution measurements were conducted using an Anton Paar particle size distribution analyzer, Litesizer® 500. Dynamic light scattering was used to measure particle size distribution based on scattering intensity, and D10, D50, and D90 were calculated. After particle size distribution measurement, zeta potential measurements were also conducted using the same analyzer. The pH during measurement was 7. Absorbance and transmittance: Measurements were carried out using the obtained SnS dispersion (5 mass%) and the diluted solution obtained by diluting this dispersion (5 mass%) with pure water to 0.001 mass% using an ultraviolet-visible-near-infrared spectrophotometer (product name "V770") manufactured by JASCO Corporation. A quartz cell with an optical path length of 10 mm was used. The mass absorption coefficient and transmittance were calculated using the Beer-Lambert law. The formula is shown below: Mass absorption coefficient (cm -1 ) = absorbance / (tin sulfide mass fraction × cell path length (cm)) transmittance (%) = 10 -(吸光度)×100 The results are shown in Table 1. A small amount of the obtained SnS dispersion was dropped onto a measurement substrate. This was heated at 70°C for 4 hours under reduced pressure to remove moisture, yielding tin sulfide particles. Figure 2 shows an image of the tin sulfide particles taken with a field-emission scanning electron microscope / transmission electron microscope (FE-SEM) (JEOL JSM-6500F), and Table 1 shows the major axis A and minor axis B dimensions of the tin sulfide particles obtained from the image. The thickness L dimension was measured using a laser microscope (Keyence Corporation, trade name "KEYENCE VK-9700"). Note that A and B were determined by visually detecting approximately 50 particles from the image and averaging them. The SnS dispersion was dried under reduced pressure in a vacuum dryer. The drying temperature was set to 70°C, and the drying time was approximately 4 hours. After drying, the tin sulfide (SnS) powder of the present invention was obtained. The resulting tin sulfide powder was identified using an X-ray diffractometer "XRD" (Malvern Panalystical, trade name "Empyrean"). The measurement results are shown in Figure 7. As a result, no peaks other than tin sulfide were detected, and the tin sulfide purity was determined to be 99% by mass or more. Next, the specific surface area was measured using the BET measurement method (specific surface area / pore distribution measurement device, Microtrac-Bell, trade name "BELSORP-max"). The results are shown in Table 1.

[0021] Comparative Example: The amount of bulk tin sulfide (purity approximately 98%) was 1.7 g, the heating temperature was 900°C for 3 hours, and the distance between the capture container 40 and the evaporation source container 30 was 3.8 cm. The deposition was carried out in the same manner as in Example 1, except that the maximum temperature of the capture container 40 was 199°C. A dispersion step was then carried out in the same manner as in Example 1, to obtain an SnS dispersion. The obtained SnS particles and SnS dispersion were subjected to the same tests and measurements as in Example 1. The results are shown in Figures 5, 6, and 7 and Table 1.

[0022] Example 2 An SnS dispersion was prepared in the same manner as in Example 1, except that in the dispersion step, in addition to normal stirring, the following ultrasonic dispersion step was performed, and various tests and measurements were carried out. Ultrasonic dispersion step: Using an ultrasonic homogenizer (QSONICA ultrasonic homogenizer, product name "Q125"), the obtained 5 mass % SnS dispersion was dispersed for 50 minutes at a frequency of 20 kHz and an amplitude of 60 μm. The results are shown in Figures 3, 5, and 7 and Table 1. Example 3 An SnS dispersion was prepared in the same manner as in Example 2, except that the frequency was 20 kHz and the amplitude was 120 μm. The obtained SnS dispersion was subjected to various tests and measurements in the same manner as in Example 1. The results are shown in Figures 4, 5, and 7 and Table 1.

[0023] [Table 1] In Table 1, "%" indicates "% by mass."

[0024] As is clear from the results shown in Figure 5, the SnS dispersion of the present invention exhibited excellent dispersibility, with no precipitation occurring even after 17 hours. On the other hand, the dispersion of the comparative example exhibited poor dispersibility, with precipitation occurring over time. Therefore, the SnS particles of the present invention exhibit such excellent dispersibility that they are believed to be able to exhibit excellent properties in a variety of applications.

[0025] Example 4 Pure water was added to 0.8 g of dried tin sulfide obtained in the same manner as in Example 1, and the mixture was stirred by a normal stirring method (stirring with a stirrer) to prepare 8 g of a 10 mass % tin sulfide aqueous solution (SnS dispersion). The obtained SnS dispersion was dispersed using an ultrasonic homogenizer (product name "Q125" manufactured by QSONICA) at a frequency of 20 kHz and an amplitude of 120 μm for 90 minutes to obtain the SnS dispersion of the present invention (the obtained dispersion is shown in FIG. 8(a)). The resulting SnS dispersion was used to measure particle size distribution. The solvent used was pure water, the same solvent as the SnS dispersion, and the SnS dispersion was diluted to 0.001% by mass before measurement. The particle size distribution was measured using an Anton Paar particle size distribution analyzer, Litesizer (registered trademark) 500. Dynamic light scattering was used as the measurement method, and particle size distribution was measured based on scattering intensity, and D10, D50, and D90 were calculated. The results are shown in Table 2 and FIG. 9.

[0026] Example 5 Pure water was added to 1.6 g of dried tin sulfide obtained in the same manner as in Example 1, and the mixture was stirred by a normal stirring method (stirring with a stirrer) to prepare 8 g of a 20 mass % tin sulfide aqueous solution (SnS dispersion). The obtained SnS dispersion was dispersed using an ultrasonic homogenizer (product name "Q125" manufactured by QSONICA) at a frequency of 20 kHz and an amplitude of 120 μm for 90 minutes to obtain the SnS dispersion of the present invention (the obtained dispersion is shown in FIG. 8(b)). The resulting SnS dispersion was used to measure particle size distribution. The solvent used was pure water, the same solvent as the SnS dispersion, and the SnS dispersion was diluted to 0.001% by mass before measurement. The particle size distribution was measured using an Anton Paar particle size distribution analyzer, Litesizer (registered trademark) 500. Dynamic light scattering was used as the measurement method, and particle size distribution was measured based on scattering intensity, and D10, D50, and D90 were calculated. The results are shown in Table 2 and FIG. 9.

[0027] Example 6 Isopropyl alcohol (special grade 2-propanol, manufactured by Kanto Chemical Co., Inc.) was added to 1.6 g of dried tin sulfide obtained in the same manner as in Example 1, and the mixture was stirred using a conventional stirring method (stirring with a stirrer) to prepare 8 g of a 20 mass % tin sulfide isopropyl alcohol solution (SnS·IPA dispersion in which SnS is dispersed in IPA). The SnS-IPA dispersion was dispersed using an ultrasonic homogenizer (QSONICA ultrasonic homogenizer, product name "Q125") at a frequency of 20 kHz and an amplitude of 120 μm for 90 minutes to obtain the SnS dispersion of the present invention. The resulting dispersion is shown in Figure 8(c). The resulting SnS·IPA dispersion was used to measure particle size distribution. The solvent used was isopropyl alcohol, the same solvent as the SnS·IPA dispersion, and the SnS·IPA dispersion was diluted to 0.001% by mass before measurement. Particle size distribution was measured using an Anton Paar particle size distribution analyzer, the Litesizer® 500. Dynamic light scattering was used to measure particle size distribution based on scattering intensity, and D10, D50, and D90 were calculated. The results are shown in Table 2 and Figure 9.

[0028] Example 7 The same procedure as in Example 6 was carried out to obtain a 20 mass % SnS·IPA dispersion. Acetylene black (DENKA BLACK Li Li-100 powder manufactured by Denka Co., Ltd., average particle size: 35 nm, specific surface area: 68 m 2 A tin sulfide-acetylene black dispersion (SnS dispersion of the present invention, SnS and acetylene black concentration: 20.8% by mass) was prepared. This acetylene black was added to a 20% by mass SnS-IPA dispersion so that the tin sulfide:acetylene black ratio was 95:5, and the dispersion was subjected to ultrasonic dispersion and mixing for 1 hour using an ultrasonic cleaner (AS ONE ASU-2, oscillator circuit: separate excitation type, high frequency output: 40 W, oscillator frequency: 42 kHz). This produced a tin sulfide-acetylene black dispersion (SnS dispersion of the present invention, SnS and acetylene black concentration: 20.8% by mass). The results are shown in FIG. 8(d). The resulting tin sulfide / acetylene black mixed dispersion was heated at 70°C for 4 hours under reduced pressure to remove water, yielding tin sulfide / acetylene black mixed particles, as shown in Figure 8(e). Figure 10(a) shows an image of tin sulfide particles taken with a field emission scanning electron microscope / transmission electron microscope (FE-SEM) (JEOL JSM-6500F, hereafter referred to as SEM). Furthermore, the tin sulfide / acetylene black mixed dispersion was diluted to 0.01% by mass, dried in the same manner, and photographed using SEM to confirm the dispersion state of the acetylene. The results are shown in Figure 10(b). Furthermore, particle size distribution measurements were performed using the resulting tin sulfide / acetylene black mixed particles. 0.1 g of tin sulfide / acetylene black mixed particles was used, and pure water was added to create a 0.01% by mass aqueous dispersion, which was then measured. Particle size distribution measurements were performed using an Anton Paar particle size distribution analyzer, the Litesizer® 500. Dynamic light scattering was used to measure particle size distribution based on scattering intensity, and D10, D50, and D90 were calculated. The results are shown in Table 2 and Figure 9. 0.5 g of tin sulfide / acetylene black mixed particles was added to pure water and stirred using a standard stirring method (using a stirrer) to produce a 1 mass% tin sulfide / acetylene black mixed aqueous dispersion, and the dispersion state in pure water was confirmed. The results are shown in Figure 8(f).

[0029] Example 8 The same procedure as in Example 6 was carried out to obtain a 20 mass % SnS·IPA dispersion. Acetylene black was added to a 20% by mass SnS-IPA dispersion so that the mass ratio of tin sulfide to acetylene black was 90:10, and ultrasonic dispersion and mixing was carried out for 1 hour to produce a tin sulfide-acetylene black mixed dispersion (SnS dispersion of the present invention, SnS and acetylene black concentration: 21.7% by mass). The resulting dispersion is shown in Figure 8(g). Tin sulfide and acetylene black mixed particles were obtained in the same manner as in Example 7. The obtained particles are shown in Figure 8(h). An image of the tin sulfide and acetylene black mixed particles taken with an FE-SEM is shown in Figure 10(c). The tin sulfide and acetylene black mixed dispersion was also diluted to 0.01% by mass, dried in the same manner, and photographed with an SEM to confirm the dispersion state of acetylene. The results are shown in Figure 10(d). Furthermore, particle size distribution was measured in the same manner as in Example 7. The results are shown in Table 2 and FIG. 0.5 g of tin sulfide / acetylene black mixed particles was added to pure water and stirred using a standard stirring method (stirring with a stirrer) to produce a 1 mass% tin sulfide / acetylene black mixed aqueous dispersion, and the dispersion state in pure water was confirmed. The results are shown in Figure 8(i).

[0030] [Table 2] In Table 2, "%" indicates "% by mass."

Claims

1. A SnS dispersion in which SnS particles are dispersed in a water-based or alcohol-based dispersion, The dispersed SnS particles have an average major axis of 100 to 2000 nm, an average minor axis of 50 to 1000 nm, and an average aspect ratio (major axis / minor axis) of 1.2 to 1.

6. SnS dispersion liquid.

2. The SnS dispersion according to claim 1, wherein the SnS dispersion is a dispersion dispersed in an aqueous dispersion, and the concentration of the SnS particles in the dispersion is 0.0001 to 50 mass %.

3. The average thickness of the SnS particles is 100 to 1000 nm, 2. The SnS dispersion according to claim 1, wherein the particle size distribution (based on scattering intensity, D50) of the SnS particles is in the range of 100 to 700 nm.

4. 2. The SnS dispersion according to claim 1, wherein the SnS purity measured by XRD of dried SnS particles is 90% by mass or more.

5. The specific surface area of ​​SnS particles is 5m by BET measurement method. 2 2. The SnS dispersion according to claim 1, wherein the SnS content is 1 / g or more.

6. The mass absorption coefficient (0.001 mass%) is 15,000 cm at a wavelength of 600 nm. －１ The SnS dispersion according to claim 1, wherein the SnS dispersion is as described above.

7. SnS particles extracted from the SnS dispersion of claim 1, The SnS particles have an average major axis of 100 to 2000 nm, an average minor axis of 50 to 1000 nm, and an average aspect ratio (major axis / minor axis) of 1.2 to 1.

6. SnS particles.

8. The average thickness of the SnS particles is 100 to 1000 nm, The SnS particles according to claim 7, wherein the particle size distribution (based on scattering intensity, D50) of the SnS particles is in the range of 100 to 700 nm.

9. 8. The SnS particles according to claim 7, wherein the SnS purity of the dried SnS particles as measured by XRD is 90% by mass or more.

10. The specific surface area of ​​SnS particles is 5m by BET measurement. 2 The SnS particles according to claim 7, wherein the SnS particle has a molecular weight of 1 / g or more.

11. 8. The SnS particles according to claim 7, which are mixed particles of SnS and acetylene black, further containing acetylene black in addition to SnS.

12. a deposition step of heating a SnS raw material contained in an evaporation source container to capture SnS in a capture container; and an isolation step of separating the resulting deposit from the capture vessel to obtain SnS particles. In the deposition process, the heating temperature of the evaporation source vessel is 700 to 900°C, and the maximum temperature of the capture vessel is 80 to 130°C. Method for producing SnS particles.

13. The average capture rate in the vapor deposition step is 20 mg / min or more. The method for producing SnS particles according to claim 12.

14. A method for producing the SnS dispersion according to claim 1, a deposition step of heating a SnS raw material contained in an evaporation source container to capture SnS in a capture container; an isolation step of separating the resulting deposit from the capture vessel to obtain SnS particles; a dispersion step of dispersing the deposit obtained in the isolation step in an aqueous or alcoholic dispersion, In the vapor deposition step, the heating temperature of the evaporation source container is 700 to 900°C, and the maximum temperature of the trapping container is 80 to 130°C.

15. The method for producing a SnS dispersion liquid according to claim 14, wherein the dispersion step comprises an ultrasonic dispersion step of performing ultrasonic dispersion at an amplitude of 50 to 150 μm.

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