JP2011157228A - Metal sulfide and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for safely producing high purity zinc sulfide not containing an oxide as an impurity and free from mixing of unnecessary metal on an industrial scale, to provide a hexagonal zinc sulfide semiconductor produced by the method, and to provide a hexagonal zinc sulfide fluorescent material which is obtained by simultaneously doping a different kind of metal when the hexagonal zinc sulfide semiconductor is produced. <P>SOLUTION: This hexagonal metal sulfide is produced under an anhydrous condition by generating a discharge between a metal electrode or a metal sulfide electrode and a metal sulfide electrode in molten sulfur. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a metal sulfide and a method for producing the same, and more particularly to a zinc sulfide phosphor and a method for producing the same.

  Metal sulfides such as tin sulfide, zinc sulfide, and copper sulfide are known to be used for various applications such as pigments and solid lubricants. As a method for producing this metal sulfide, a dry method or a wet method is known.

  The dry method is a method in which a metal and hydrogen sulfide or elemental sulfur are reacted at a high temperature under normal pressure or under pressure, or a method in which a metal compound and a sulfide such as thioamide are vaporized and reacted. Specific examples thereof include, for example, a method in which a reactive metal powder is reacted with elemental sulfur (see Patent Document 1), and as an improvement thereof, the massive metal and sulfur are reacted while the massive metal is crushed. A method (see Patent Document 2) is known. Furthermore, a method is known in which a metal chloride and thioacetamide are vaporized and reacted (see Patent Document 3).

  In the dry method, when powder metal is used as a metal raw material, processing from an ingot or the like is necessary. Moreover, when using solid sulfur as a sulfur source, a powdery thing is required. Generally, metal sulfides for pigments and solid lubricants are used in powder form, but most of the metal sulfides synthesized by heating in the dry manufacturing process are sintered, so they are commercialized through a pulverization process. Is done.

  On the other hand, the wet method is a method of reacting an aqueous solution of a metal compound with hydrogen sulfide, sodium hydrosulfide (sodium hydrogen sulfide), or the like. For example, a method of reacting a metal alkoxide with hydrogen sulfide (see Patent Document 4), metal A method of reacting a salt with sodium sulfide in water (see Patent Document 5) and a method of reacting a metal salt with a thioamide such as thioacetamide (Patent Document 6) are known.

  Also known is a method of generating a pulse plasma in sulfur to sulfidize a metal (see Patent Document 7, Patent Document 8, and Patent Document 9).

JP-T-2002-511517 JP 2007-284309 A JP 2004-091233 A JP-A-6-293503 WO2003 / 020848 Special table 2004-520260 gazette USSR No. 860428 JP-A 61-199096 International Publication No. 2009/099250

  In the methods described in Patent Document 1 and Patent Document 2 relating to the dry method, it is necessary to bring an explosive substance such as sulfur into contact with a metal at a high temperature, and it is difficult to ensure safety. In addition, the method of Patent Document 3 requires special equipment such as vaporization, and is difficult to implement on an industrial scale.

  On the other hand, in the method using a metal alkoxide as in Patent Document 4 relating to the wet method, the raw material is easily hydrolyzed, and when the oxide is contained as an impurity, the oxide is likely to be taken into the sulfide as an impurity. . Therefore, in order to obtain a high-purity product, strict management is required, and a hydrolyzate is generated during the reaction, so that it is substantially difficult to obtain a high-purity sulfide. The same applies to the methods described in Patent Document 5 and Patent Document 6, and hydrolysis of raw materials and products during the reaction is unavoidable, and it is difficult to obtain a high-purity sulfide.

Furthermore, only a thermally stable cubic metal sulfide can be obtained in both dry and wet processes, and it is extremely difficult to obtain a hexagonal metal sulfide.
Moreover, although patent document 7 and patent document 8 have a description of the manufacturing method using pulsed plasma, they do not describe a method of doping different types of metals into sulfides generated using pulsed plasma method.

  Furthermore, Patent Document 9 describes a method of doping a sulfide produced using a pulse plasma method with a different metal, but any of Patent Document 7, Patent Document 8, and Patent Document 9, A common metal electrode is used for both electrodes, and it is not possible to suppress unnecessary metal contamination in the sulfide generated from the metal electrode.

  An object of the present invention is to provide a method for producing high-purity zinc sulfide which does not contain oxides as impurities and is free of unnecessary metal contamination on an industrial scale, and in addition, the above-described method. It is another object of the present invention to provide a hexagonal zinc sulfide semiconductor manufactured by the above method, and further to provide a hexagonal zinc sulfide phosphor obtained by doping a different metal at the same time when the hexagonal zinc sulfide semiconductor is produced.

  The inventors of the present invention have made extensive studies to achieve the above object, and in molten sulfur, at least one of the metal sulfide electrodes is used, and by generating a discharge between the electrodes, the metal sulfide is removed under anhydrous conditions. The inventors have found that it can be obtained and have reached the present invention.

ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing a metal sulfide by discharge between a metal electrode or a metal sulfide electrode, and a metal sulfide electrode in molten sulfur is provided.
The structure of the metal sulfide produced according to the present invention is not particularly limited, and various structures may be adopted depending on the metal to be sulfided, such as amorphous, cubic, hexagonal, and the use of the sulfide. However, a useful structure includes hexagonal metal sulfide, and hexagonal zinc sulfide is particularly preferable in consideration of use as a phosphor.

  In the present invention, the molten sulfur acts as a metal sulfiding agent. Sulfur usually flows when heated to 130-150 ° C, and becomes liquid when it exceeds 150 ° C. The molten sulfur used in the present invention is sulfur in a molten state obtained by heating a sulfur raw material such as sulfur powder and rubbery sulfur to 130 to 150 ° C. Molten sulfur can be used as long as at least part of the sulfur is in a molten state, but it is preferable that substantially all of the sulfur is in a molten state in consideration of the efficiency of plasma discharge.

  As the metal electrode, a Group 2 metal electrode, for example, an alkaline earth metal such as magnesium, calcium, strontium, or barium, or a metal belonging to Group 12 of the periodic table such as zinc or cadmium can be used. These metals may be used alone or in combination of several metals as an alloy.

The metal sulfide electrode is preferably an electrode in which metal sulfides such as copper sulfide, manganese sulfide, iron sulfide, and zinc sulfide are mixed alone or in advance so as to be uniform.
The metal sulfide used for the metal sulfide electrode needs to have electrical conductivity. In addition, the metal sulfide electrode can be produced by molding a powder raw material using a method such as heating / pressure molding or heat molding.

As a method of molding the metal sulfide electrode, for example, a method of applying a pressure of about 200 to 2000 Kg / cm ^{2 of} copper sulfide and press molding and baking at about 600 to 800 ° C. to obtain a molded product, or While applying a pressure of about 200 to 2000 kg / cm ^2, a method of applying pressure molding by applying heat of about 400 to 800 ° C. can be used.

As a form of a metal electrode and a metal sulfide electrode, any form, such as a rod shape, a wire shape, and a plate shape, may be used. The sizes of both poles may be the same or different.
In the method of the present invention, plasma is generated by discharging between electrodes in molten sulfur, preferably continuous direct current discharge or pulse discharge.

  The voltage for generating plasma is not particularly limited, and is preferably in the range of 60 to 400 V, and in the range of 80 to 300 V in consideration of the range of 50 to 500 V, safety, and the necessity of special equipment. More preferred.

It does not restrict | limit especially as an electric current which generate | occur | produces plasma, It is preferable to implement in the range of 0.2-10A in consideration of the range of 0.1-20A and energy efficiency.
The interval for applying the pulsed plasma is not particularly limited, but is preferably 5 to 100 milliseconds, and more preferably 6 to 50 milliseconds.

  Needless to say, the duration per pulsed plasma is also different depending on the applied voltage and current, but usually in the range of 1 to 50 microseconds, preferably in the range of 2 to 30 microseconds in consideration of the efficiency of discharge. To be implemented.

  The temperature of the molten sulfur at the time of performing the pulse plasma discharge is not particularly limited, and is preferably carried out in the range of room temperature to 300 ° C. An excessively high temperature is not preferable because the vapor pressure of sulfur increases and a special reaction vessel is required, and an excessively low temperature is not preferable because the generation efficiency of sulfide at the time of plasma generation decreases. 60 degreeC or more and 200 degrees C or less are preferable, and 80 degreeC or more and 180 degrees C or less are more preferable.

  The atmosphere for carrying out the present invention is not particularly limited, and it can be carried out under reduced pressure, under pressure, or under normal pressure, but usually, in consideration of safety and operability, nitrogen, argon, etc. It can be carried out under an inert gas.

  In the present invention, it is also possible to apply vibration to the electrode. By giving vibration, there is no stagnation of metal sulfides deposited between the electrodes, and discharge is performed efficiently, which is preferable. The method of applying vibration is not particularly limited, and may be a method of applying vibration periodically or intermittently.

  The metal sulfide produced according to the present invention is suitable for doping of different metals. Therefore, in another aspect of the present invention, a metal sulfide doped with at least one element selected from copper, silver, gold, manganese and rare earth elements can also be produced.

  The method for doping at least one element selected from copper, silver, gold, manganese and rare earth elements is not particularly limited, and may be used in combination with sulfur to be reacted or an organic sulfur compound. It is desirable to alloy the electrode to be made.

It goes without saying that the composition amount when the element to be doped is pre-alloyed to the electrode is different depending on the element to be doped. Usually, the element amount is 1 ppmw (1 × 10 ⁻⁴ wt%) to It is desirable to exist in the range of 50% by weight. Like copper, when an appropriate density | concentration can be adjusted by chemical treatment after production | generation, it can add and alloy in the range of 100 ppmw (0.01 weight%)-50 weight%. In the case of doping an element that is difficult to adjust by chemical treatment, it is preferably added and alloyed in the range of ¹ to 1000 ppmw (1 × 10 ⁻⁴ to 1 × 10 ⁻¹ wt%).

  The element can be doped into the metal sulfide by causing the element to be doped to coexist in the molten sulfur and discharging between the electrodes. The mode of coexisting the element to be doped in the molten sulfur is not particularly limited, but sulfides such as copper sulfide, silver sulfide, gold sulfide, manganese sulfide or rare earth sulfide, and corresponding sulfates and hydrochlorides. Preferably, mineral salts such as nitrate, organic acid salts such as formate and acetate, and organic complexes such as acetylacetonate are melted together with sulfur. In view of the purity and operability of the phosphor obtained by doping the element, addition of sulfide is preferable.

  In the present invention, further, elements such as halogens such as chlorine and bromine, aluminum, gallium, indium and iridium may be doped into the metal sulfide as necessary. The introduction method of these elements is not particularly limited, but molten sulfur, halides, aluminum sulfide, gallium sulfide, indium sulfide, iridium sulfide, and the like, corresponding sulfates, hydrochlorides, nitrates, etc. It is preferable to add an organic acid salt such as a mineral acid salt, formate or acetate, and an organic complex such as acetylacetonate and melt them together. From the viewpoint of purity and operability of the phosphor obtained by doping the element, addition of a halide or sulfide is preferable.

The amount of the element to be doped added to sulfur is preferably in the range of 0.1 to 5000 ppmw (1 × 10 ^{−5 to} 5 × 10 ⁻¹ wt%) sulfide based on the weight of molten sulfur, and 1 to 3000 ppmw ( The range of 1 × 10 ^{−4 to} 3 × 10 ⁻¹ wt% is more preferable.

  Since the metal sulfide produced | generated by this method accumulates in molten sulfur, after collect | recovering molten sulfur containing a metal sulfide by a general method, metal sulfide can be obtained by removing sulfur. For example, sulfur can be dissolved in a good solvent such as carbon disulfide, and the residual metal sulfide can be recovered. Alternatively, the metal sulfide can be obtained by heating to 200 ° C. under vacuum to sublimate and remove sulfur.

  By the production method of the present invention, it is possible to produce a hexagonal metal sulfide with high productivity and high purity without causing hydrolysis. Furthermore, it is possible to obtain a metal sulfide in which unnecessary metal used for the electrode is suppressed. The present invention also provides a method for producing a composite sulfide in which a different metal such as copper is doped with high dispersibility. In particular, hexagonal zinc sulfide produced by the method of the present invention, and copper doped with high dispersibility are very useful as phosphors.

  The high productivity, the suppression of unnecessary metal contamination, and the high dispersibility of the doped metal, all of which are the effects of the present invention, are mainly brought about by using a metal sulfide electrode as at least one of the electrodes. When metal sulfide electrodes are used, metal anion species are more easily generated than when only metal electrodes are used. Therefore, the generation balance of metal active species between both electrodes is smoothed, and the reaction occurs easily. Therefore, the production amount of metal sulfide can be increased.

  Furthermore, by using a metal sulfide electrode for at least one, it is easier to generate metal anion species than when both electrodes are used as metal electrodes, thereby suppressing the generation of metal species due to the generation of metal melt splashes and coupling of metal radicals. As a result, there is an advantage that mixing of zero-valent metal from the electrode can be suppressed.

  Furthermore, even when producing a metal sulfide doped with a metal different from the metal used for the metal sulfide electrode, the doped metal is uniformly dispersed in the electrode material, and the reaction field is always present. Since the metal to be doped exists, there is an advantage that high dispersibility can be maintained in the metal sulfide produced by the doped metal.

FIG. 1 is an XRD spectrum of an example of a metal sulfide obtained by the production method of the present invention. FIG. 2 is a TEM photograph of an example of a metal sulfide obtained by the production method of the present invention. FIG. 3 is a photograph showing a copper mapping analysis result by TEM-EDX analysis of an example of a metal sulfide obtained by the production method of the present invention. FIG. 4 is an XRD spectrum of an example of a metal sulfide obtained by another production method of the present invention. FIG. 5 is an XRD spectrum of an example of a metal sulfide obtained by a production method using only a metal electrode for comparison with the present invention.

The method for producing a metal sulfide of the present invention is characterized in that discharge is performed between two metal electrodes using metal sulfide as at least one electrode material in molten sulfur.
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these. In addition, the measurement in an Example was implemented on the following conditions.

[TEM observation]
Using JEOL JEM-3000F (resolution 0.17 nm), observation was performed at an acceleration voltage of 300 kV and a magnification of 50,000 times. For the detector of EDX, System SIX manufactured by NORAN was used.

  When observing at a magnification of 500,000 times, the copper dispersibility is calculated by EDX analysis of the copper concentration at 10 points on any 2 nm square in the field where the particles are present, and from the average value of 10 copper concentration measurements. Evaluation was based on the divergence.

[XRD measurement]
Measurement was performed using MiniFlexII manufactured by Rigaku Corporation with a voltage of 30 kV, a current of 15 mA, a divergence slit of 1.25 °, a scattering slit of 1.25 °, and a light receiving slit of 0.3 mm.

[Quantification of luminescence center by ICP]
Measurement was carried out using Irel AP, Jarrel Ash. The pretreatment was performed by the KHSO ₄ melting method.

[Fluorescence spectrum measurement]
Using a spectrofluorophotometer FP-6500 manufactured by JASCO Corporation, the measurement was performed under conditions of 1 mm slit mounting, excitation wavelength of 320 nm, excitation bandwidth of 3 nm, and fluorescence bandwidth of 3 nm.
[Production Example 1]
<Preparation of sintered copper sulfide>
Copper (I) sulfide powder was put into a stainless steel container having a diameter of 15 mm, pressure of 400 kg / cm ² was applied, pressure molding was performed, and the mixture was put into a crucible. After putting the crucible into the firing furnace and replacing with argon, the firing furnace was heated to a furnace temperature of 800 ° C. at 10 ° C. per minute, and after reaching the set temperature, the temperature in the firing furnace was kept at the set temperature for 3 hours, Until cooled. The bulk (bulk) density of the obtained copper sulfide sintered body was 3.55 g / cm ³ .

Here, the bulk density is defined as a value obtained by measuring the volume and mass of a molded product and dividing the mass by the volume.
[Production Example 2]
<Preparation of zinc sulfide / copper sulfide composite sulfide electrode>
Zinc acetate dihydrate 65.9 g, copper nitrate 7.5 g (equivalent to 105,000 ppm copper (10.2 wt%)), thioacetamide 45.0 g, and acetic acid 5 g were dissolved in 500 g of ion-exchanged water. A 2 L three-necked flask was equipped with a Gene Stark, a reflux tube, a thermometer, and a stirrer. After injecting 800 ml of o-xylene, the system was purged with nitrogen. Adjusting the internal temperature of the oil bath to 150 ° C, raising the temperature of o-xylene in the flask to 130 ° C, adding a solution containing zinc acetate at 100 ml / hour, and removing the flowing water with Gene Stark. Advanced. A solution containing all the zinc acetate was fed in about 6 hours, and water remaining in the flask was removed in another 30 minutes. After cooling to room temperature, the precipitated sulfide was precipitated, the organic solvent was removed, the target product was collected, and dried in a vacuum dryer at 100 ° C. for 12 hours. The recovered amount of sulfide was 31.6 g, and the copper content measured by ICP emission analysis was 103000 ppm (10.3% by weight). This reaction was repeated 4 times to obtain 126 g of sulfide powder. 112 g of the obtained sulfide powder was put into a mold having a diameter of 3 inches (7.6 cm) and filled in a plasma sintering machine. The mold was depressurized to 130 Pa and held for 10 minutes, and then argon was injected to release it to normal pressure. This operation was performed three times to remove oxygen and moisture in the sulfide complex. Thereafter, the pressure inside the mold is reduced to 140 Pa, a pressure of 123 kg / cm ² is applied, the temperature is raised to 700 ° C. at 50 ° C./min, and after the mold temperature reaches 700 ° C., argon is introduced into the mold to reduce the pressure. Was released. Thereafter, the temperature was raised to 850 ° C. at 15 ° C./min in an argon atmosphere, held for 10 minutes, the pressure was released, and the mixture was cooled to room temperature. The molded body was removed from the mold, and the thickness of the molded body having a diameter of 3 inches (7.6 cm) was measured and found to be 6.31 mm. The obtained molded product had a bulk density of 3.89 g / cm ³ and a relative density (ratio of measured density to theoretical density) of 0.970.

  100 g of powdered sulfur was added to a 100 ml beaker and melted at 140 ° C. Next, a cylindrical zinc electrode (purity 99% or more) having a diameter of 5 mm and a length of 100 mm and the copper sulfide sintered body electrode produced in Production Example 1 are inserted into molten sulfur, and the distance between the electrodes is fixed to 1 mm. did. Vibration was applied to prevent reaction products from accumulating on the electrode surface and increase reaction efficiency. Each electrode was connected to an AC power source, and a pulse plasma was generated by applying a pulse of 200 V, 60 A, a pulse interval of 20 milliseconds, and a duration of 100 microseconds per pulse discharge. As a result of continuing the reaction for 30 minutes, the mass reduction of the zinc electrode was 257 mg, and the mass reduction of the copper sulfide sintered body electrode was 44 mg. The mass of the solid powder obtained after the sulfur was distilled off under reduced pressure was 448 mg. In order to remove the isolated CuS particles, this powder was washed with stirring at 25 ° C. for 60 minutes using 50 g of 5% aqueous NaCN solution, washed 5 times with ion-exchanged water, filtered, and then heated and dried under vacuum. The mass of the obtained powder was 214 mg. From the XRD measurement, only the peak derived from hexagonal zinc sulfide was detected, and the peak of copper sulfide was not detected. This means that copper sulfide is dispersed in zinc sulfide as a very small dispersion, and the amount thereof is very small. Further, when the diffraction peak of a standard sample of hexagonal zinc sulfide and copper sulfide is compared with the peak of this powder, the diffraction peak derived from hexagonal zinc sulfide (Wurtzite-2H-ZnS) (26.8 °, 28.4). °, 30.4 °, 39.5 °, 47.4 °, 51.6 °, 56.2 °) were detected, but the peak derived from copper sulfide (Covellite-CuS) (31.5 °, 32 .7 °, 52.4 °) were not detected. The results are shown in FIG. The copper content contained in the obtained powder was estimated to be 9130 ppm from ICP analysis.

A TEM photograph (magnification: 50,000 times) of the obtained powder is shown in FIG. As a result of TEM observation, it was found that the product was obtained as a crystalline granular material of about 5 to 50 nm.
As shown in FIG. 3, copper mapping analysis was performed by TEM-EDX analysis, and the results are shown in Table 1. It can be seen that copper is detected from all the particles, and there is no localized uneven distribution, which is highly dispersed.

  100 g of powdered sulfur was added to a 100 ml beaker and melted at 140 ° C. Next, a cylindrical zinc electrode (purity 99% or more) having a diameter of 5 mm and a length of 100 mm and the copper sulfide sintered body electrode produced in Production Example 1 are inserted into molten sulfur, and the distance between the electrodes is fixed to 1 mm. did. Vibration was applied to prevent reaction products from accumulating on the electrode surface and increase reaction efficiency. Each electrode was connected to an AC power source, and a pulse plasma was generated by applying a pulse of 200 V, 60 A, a pulse interval of 20 milliseconds, and a duration of 20 microseconds per pulse discharge. As a result of continuing the reaction for 30 minutes, the mass reduction of the zinc electrode was 245 mg, and the mass reduction of the copper sulfide sintered body electrode was 41 mg. The mass of the solid powder obtained after the sulfur was distilled off under reduced pressure was 437 mg. In order to remove the isolated CuS particles, this powder was washed with stirring at 25 ° C. for 60 minutes using 50 g of 5% aqueous NaCN solution, washed 5 times with ion-exchanged water, filtered, and then heated and dried under vacuum. The mass of the obtained powder was 217 mg. From the XRD measurement, only the peak derived from hexagonal zinc sulfide was detected, and the peak of copper sulfide was not detected. This means that copper sulfide is dispersed in zinc sulfide as a very small dispersion, and the amount thereof is very small. Further, when the diffraction peak of a standard sample of hexagonal zinc sulfide and copper sulfide is compared with the peak of this powder, the diffraction peak derived from hexagonal zinc sulfide (Wurtzite-2H-ZnS) (26.8 °, 28.4). 30.4 °, 39.5 °, 47.4 °, 51.6 °, 56.2 °) were detected, but diffraction peaks derived from copper sulfide (Covellite-CuS) (31.5 °, (32.7 °, 52.4 °) were not detected. The results are shown in FIG. The copper content contained in the obtained powder was estimated to be 7040 ppm from ICP analysis.

  100 g of powdered sulfur was added to a 100 ml beaker and melted at 140 ° C. Next, a cylindrical zinc electrode (purity 99% or more) having a diameter of 5 mm and a length of 100 mm and the zinc sulfide / copper sulfide composite sulfide sintered body electrode produced in Production Example 2 were inserted into molten sulfur, and the gap between the electrodes Was fixed at 1 mm. Vibration was applied to prevent reaction products from accumulating on the electrode surface and increase reaction efficiency. Each electrode was connected to an AC power source, and a pulse plasma was generated by applying a pulse of 200 V, 60 A, a pulse interval of 20 milliseconds, and a duration of 100 microseconds per pulse discharge. As a result of continuing the reaction for 30 minutes, the mass reduction of the zinc electrode was 193 mg, and the mass reduction of the zinc sulfide / copper sulfide composite sulfide sintered body electrode was 29 mg. The mass of the solid powder obtained after the sulfur was distilled off under reduced pressure was 228 mg. In order to remove the isolated CuS particles, this powder was washed with stirring at 25 ° C. for 60 minutes using 50 g of 5% aqueous NaCN solution, washed 5 times with ion-exchanged water, filtered, and then heated and dried under vacuum. The mass of the obtained powder was 199 mg. From the XRD measurement, only the peak derived from hexagonal zinc sulfide was detected, and the peak of copper sulfide was not detected. This means that copper sulfide is dispersed in zinc sulfide as a very small dispersion, and the amount thereof is very small. Further, when the diffraction peak of a standard sample of hexagonal zinc sulfide and copper sulfide is compared with the peak of this powder, the diffraction peak derived from hexagonal zinc sulfide (Wurtzite-2H-ZnS) (26.8 °, 28.4). 30.4 °, 39.5 °, 47.4 °, 51.6 °, 56.2 °) were detected, but diffraction peaks derived from copper sulfide (Covellite-CuS) (31.5 °, (32.7 °, 52.4 °) were not detected. The results are shown in FIG. The copper content contained in the obtained powder was estimated to be 1080 ppm from ICP analysis.

<Comparative Example 1>
In Example 1, it carried out like Example 1 except having used the bipolar zinc electrode. The XRD measurement result of the obtained zinc sulfide is shown in FIG. Copper sulfide was dispersed in zinc sulfide, and the dispersion was very small and was not detected because it was very small. The obtained zinc sulfide has diffraction peaks (26.8 °, 28.4 °, 30.4 °, 39.5 °, 47.4 °, 51 °) derived from hexagonal zinc sulfide (Wurtzite-2H-ZnS). .6 °, 56.2 °) were detected, while a strong diffraction peak of 43.2 ° derived from metallic zinc (Zinc-Zn) was also observed. In Example 1, the relative ratio of the peak intensity of 43.2 ° derived from metallic zinc to the peak intensity of 47.6 ° derived from hexagonal zinc sulfide was 9.7%, and Examples 2 and 3 Thus, no peak derived from metallic zinc is detected. On the other hand, in the comparative example 1, this relative ratio is 30.9%, and it turns out that a lot of metallic zinc is contained.

Claims (11)

  A method for producing a metal sulfide by discharge between a metal electrode and a metal sulfide electrode in molten sulfur.   The manufacturing method according to claim 1, wherein the metal sulfide electrode is a metal sulfide electrode containing copper sulfide.   The manufacturing method according to claim 1, wherein the metal sulfide electrode is a metal sulfide composite electrode including copper sulfide and zinc sulfide.   The manufacturing method according to claim 1, wherein the metal sulfide electrode is a metal sulfide electrode in which at least one metal element selected from copper, silver, gold, manganese, and a rare earth element is alloyed.   The manufacturing method according to any one of claims 1 to 4, wherein the discharge is direct current continuous discharge or pulse discharge.   The manufacturing method according to any one of claims 1 to 5, wherein the molten sulfur contains at least one metal element selected from copper, silver, gold, manganese, and a rare earth element.   The manufacturing method according to any one of claims 1 to 6, wherein the metal electrode is a metal electrode selected from zinc, cadmium, magnesium, calcium, strontium, and barium.   A method for producing zinc sulfide by performing pulse discharge between a zinc electrode and a metal sulfide electrode containing copper sulfide in molten sulfur.   In molten sulfur, a pulse discharge is performed between a zinc electrode and a metal sulfide electrode in which at least one metal element selected from copper, silver, gold, manganese, and a rare earth element is alloyed. A method for producing zinc sulfide doped with one kind of metal element.   By performing pulse discharge between a zinc electrode and a metal sulfide electrode in molten sulfur containing at least one metal element selected from copper, silver, gold, manganese and rare earth elements, the at least one kind A method for producing zinc sulfide doped with a metal element.   The hexagonal zinc sulfide-copper phosphor produced by the method according to claim 3 or 8, wherein the copper content is 1000 ppm or more and the dispersibility of the copper concentration is within ± 5%.