Method for producing sulfur polymer and method for producing positive electrode material for lithium sulfur secondary battery

Abstract

To provide a method for producing a sulfur polymer by reacting sulfur with an isocyanuric acid derivative, using the isocyanuric acid derivative as a crosslinker, to suppress generation of a sulfide gas, and produce a sulfur polymer with a high C-S bond / C-C bond ratio that is easy to handle.SOLUTION: A method for producing a sulfur polymer includes a crosslinking reaction step for reacting sulfur with an isocyanuric acid derivative represented by a general formula (1), or the isocyanuric acid derivative represented by the general formula (1) and a triazine derivative represented by a general formula (2), in the presence of a dithiocarbamate-based catalyst at 120-220°C. Relative to combined total of the isocyanuric acid derivative represented by the general formula (1) and the triazine derivative represented by the general formula (2), the isocyanuric acid derivative represented by the general formula (1) is 80.0-100.0 mass%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a method for producing a sulfur polymer obtained by reacting sulfur with a crosslinking agent, and a method for producing a positive electrode material for lithium-sulfur secondary batteries. [Background technology]

[0002] Sulfur polymers are obtained by reacting sulfur with a crosslinking agent, thereby polymerizing the sulfur using the crosslinking agent. Currently, they are used in a variety of applications, or are expected to be used in a variety of applications.

[0003] One application of sulfur polymers is, for example, as a cathode material for lithium-sulfur batteries. These lithium-sulfur batteries are expected to be next-generation rechargeable batteries due to their use of sulfur, which is a resource-rich material, and their high theoretical capacity (1672 mAh / g). However, a challenge to the practical application of lithium-sulfur batteries is the inclusion of the sulfur intermediate Li2S in the electrolyte. X This includes the elution and volume expansion of the reaction intermediate Li2S. X Because it can reduce the elution of sulfur and alleviate stress caused by the expansion and contraction of sulfur, sulfur polymers are suitably used as cathode materials for lithium-sulfur batteries.

[0004] As a sulfur polymer for the positive electrode material of a lithium sulfur battery, for example, Patent Document 1 discloses a lithium sulfur battery positive electrode material in which liquid sulfur formed after the sulfur powder has melted and triallyl isocyanurate are copolymerized by a reaction, and the sulfur is immobilized by chemical bonding, resulting in a sulfur content of 50 to 90% by mass in the lithium sulfur battery positive electrode material. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Chinese Patent No. 109950472 [Overview of the project] [Problems that the invention aims to solve]

[0006] Patent Document 1 describes a method for producing a sulfur polymer using triallyl isocyanurate as a crosslinking agent. However, the present inventors found that it is necessary to heat the sulfur and triallyl isocyanurate to 250°C to react, and although a sulfur polymer is obtained as a result, a large amount of sulfide gas is generated as a by-product when the sulfur raw material reacts with the crosslinking agent during the reaction. Furthermore, the crosslinking agent may partially decompose at high temperatures. In addition, the resulting sulfur polymer has a low CS bond / CC bond ratio, making it rigid and inflexible, resulting in poor volume mitigation. Moreover, it was found that there is a concern that washing or other methods performed to improve this ratio will reduce the yield of the sulfur polymer.

[0007] Therefore, the method described in Patent Document 1 has a low CS bond / CC bond ratio, raising concerns that it may not perform well in cases where flexibility is required. Furthermore, if washing or other processes are performed to improve this ratio, there are concerns that the yield of sulfur polymer may decrease.

[0008] Accordingly, the object of the present invention is to provide a method for producing a sulfur polymer by reacting sulfur with an isocyanuric acid derivative as a crosslinking agent, wherein the generation of sulfide gas is suppressed, the obtained sulfur polymer has a high CS bond / CC bond ratio, and the sulfur polymer is easy to handle, and a method for producing a positive electrode material for lithium sulfur secondary batteries. [Means for solving the problem]

[0009] As a result of intensive studies, the present inventors have found that when sulfur is reacted with an isocyanuric acid derivative, or an isocyanuric acid derivative and a triazine derivative, under a specific catalyst within a specific temperature range, generation of sulfide gas can be suppressed, and a sulfur polymer having a high C-S bond / C-C bond ratio can be obtained, leading to the completion of the present invention.

[0010] That is, the present invention (1) relates to sulfur and the following general formula (1):

[0011]

Chemical formula

[0012] (In the formula, among R 1 , R 2 and R 3 , one, two or all are substituents capable of reacting with sulfur, and the substituent capable of reacting with sulfur is a linear or branched alkenyl group having 2 to 15 carbon atoms (which may contain a halogen element), a linear or branched alkenyl group having 2 to 15 carbon atoms (which may contain a halogen element), a sulfide group, a mercapto group, a glycidyl group, a cyano group, a carbonyl group, and a linear or branched hydrocarbon group having 1 to 15 carbon atoms having a halogen, selected from the group consisting of groups; among R 1 , R 2 and R 3 , when one or two are substituents capable of reacting with sulfur, the rest are a linear or branched alkyl group having 1 to 15 carbon atoms (which may contain a halogen element), a linear or branched alkoxy group having 2 to 15 carbon atoms (which may contain a halogen element), an aryl group having 6 to Twenty carbon atoms, amino group, amide group, imino group, carboxyl group, hydroxyl group, ester group, nitro group, nitrile group, sulfonyl group, silyl group and hydrogen atom. Among R 1 , R 2 and R 3 , they may be the same or different.) An isocyanuric acid derivative represented by the above general formula (1) and the following general formula (2):

[0013] [ka]

[0014] (In the formula, R 4 , R 5 and R 6 Of these, one, two, or all are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (substituents are alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), R 4 , R 5 and R 6 If one or two of these are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (with substituents being alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (may contain halogen elements), aryl groups having 6 to 20 carbon atoms, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, glycidyl groups, nitro groups, nitrile groups, sulfide groups, mercapto groups, sulfonyl groups, silyl groups, and hydrogen atoms. 4 , R 5 and R 6 They may be the same or different. A triazine derivative represented by, The process includes a crosslinking reaction step in which the mixture is reacted at 120-220°C in the presence of a dithiocarbamate-based catalyst. The ratio of the isocyanuric acid derivative represented by general formula (1) to the total of the isocyanuric acid derivative represented by general formula (1) and the triazine derivative represented by general formula (2) is 80.0 to 100.0% by mass. This invention provides a method for producing sulfur polymers characterized by the following:

[0015] Furthermore, in the present invention (2), the isocyanuric acid derivative represented by the general formula (1) is the following formula (1A):

[0016] [ka]

[0017] The triazine derivative represented by the general formula (2) is a 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and the triazine derivative represented by the general formula (2) is the following formula (2A):

[0018] [ka]

[0019] The present invention provides a method for producing the sulfur polymer of (1), characterized by being 2,4,6-tris(allyloxy)-1,3,5-triazine represented by .

[0020] Furthermore, the present invention (3) provides a method for producing the sulfur polymer according to (1) or (2), characterized in that the dithiocarbamate-based catalyst is zinc diethyldithiocarbamate.

[0021] Furthermore, the present invention (4) provides a method for producing any of the sulfur polymers described in (1) to (3), characterized in that the sulfur content in the sulfur polymer is 50% by mass or more.

[0022] Furthermore, the present invention (5) provides a method for producing any of the sulfur polymers (1) to (4) described above, characterized in that when the sulfur polymer is analyzed using X-ray photoelectron spectroscopy (XPS), the ratio (B / A) of the peak area of ​​peak B, which has a peak top at around 286.3 eV derived from CS, CO, and CN bonds, to the peak area of ​​peak A, which has a peak top at around 285 eV derived from CC and CH bonds, is 0.40 to 0.95.

[0023] Furthermore, the present invention (6) provides a method for producing any of the sulfur polymers (1) to (5), characterized in that the sulfur polymer is a sulfur polymer used as a positive electrode material for a lithium-sulfur secondary battery.

[0024] Furthermore, the present invention (7) involves sulfur and The following general formula (1):

[0025] [ka]

[0026] (In the formula, R 1 , R 2 and R 3 Of these, one, two, or all are substituents that can react with sulfur, and the substituents that can react with sulfur are groups selected from the group consisting of linear or branched alkenyl groups having 2 to 15 carbon atoms (which may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (which may contain halogen elements), sulfide groups, mercapto groups, glycidyl groups, cyano groups, carbonyl groups, and linear or branched hydrocarbon groups having 1 to 15 carbon atoms and containing halogens, R 1 , R 2 and R 3If one or two of these are substituents that can react with sulfur, the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (which may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (which may contain halogen elements), and aryl groups, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, nitro groups, nitrile groups, sulfonyl groups, silyl groups, and hydrogen atoms having 6 to 20 carbon atoms. 1 , R 2 and R 3 They may be the same or different. An isocyanuric acid derivative represented by the above general formula (1) and the following general formula (2):

[0027] [ka]

[0028] (In the formula, R 4 , R 5 and R 6 Of these, one, two, or all are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (substituents are alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), R 4 , R 5 and R 6If one or two of these are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (with substituents being alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (may contain halogen elements), aryl groups having 6 to 20 carbon atoms, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, glycidyl groups, nitro groups, nitrile groups, sulfide groups, mercapto groups, sulfonyl groups, silyl groups, and hydrogen atoms. 4 , R 5 and R 6 They may be the same or different. A triazine derivative represented by, The process includes a crosslinking reaction step in which the mixture is reacted at 120-220°C in the presence of a dithiocarbamate-based catalyst. The ratio of the isocyanuric acid derivative represented by general formula (1) to the total of the isocyanuric acid derivative represented by general formula (1) and the triazine derivative represented by general formula (2) is 80.0 to 100.0% by mass. This invention provides a method for manufacturing a positive electrode material for a lithium-sulfur secondary battery, characterized by the above. [Effects of the Invention]

[0029] According to the present invention, a method for producing a sulfur polymer is provided, which involves reacting sulfur with an isocyanuric acid derivative as a crosslinking agent, thereby obtaining a sulfur polymer, wherein the generation of sulfide gas is suppressed, the decomposition of the crosslinking agent is suppressed, and the obtained sulfur polymer has a high CS bond / CC bond ratio. The present invention also provides a method for producing a positive electrode material for lithium-sulfur secondary batteries. [Brief explanation of the drawing]

[0030] [Figure 1] Figure 1 shows the analysis results of the X-ray photoelectron spectroscopy method used in Example 1. [Figure 2] Figure 2 shows the analysis results of the X-ray photoelectron spectroscopy for Comparative Example 1. [Figure 3] Figure 3 shows the charge-discharge curve of the sulfur polymer in Example 1. [Figure 4] Figure 4 shows the charge-discharge graph (10 cycles) of the electrode fabricated using the sulfur polymer of Example 1. [Modes for carrying out the invention]

[0031] The present invention provides a method for producing a sulfur polymer using sulfur, The following general formula (1):

[0032] [ka]

[0033] (In the formula, R 1 , R 2 and R 3 Of these, one, two, or all are substituents that can react with sulfur, and the substituents that can react with sulfur are groups selected from the group consisting of linear or branched alkenyl groups having 2 to 15 carbon atoms (which may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (which may contain halogen elements), sulfide groups, mercapto groups, glycidyl groups, cyano groups, carbonyl groups, and linear or branched hydrocarbon groups having 1 to 15 carbon atoms and containing halogens, R 1 , R 2 and R 3If one or two of these are substituents that can react with sulfur, the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (which may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (which may contain halogen elements), and aryl groups, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, nitro groups, nitrile groups, sulfonyl groups, silyl groups, and hydrogen atoms having 6 to 20 carbon atoms. 1 , R 2 and R 3 They may be the same or different. An isocyanuric acid derivative represented by the above general formula (1) and the following general formula (2):

[0034] [ka]

[0035] (In the formula, R 4 , R 5 and R 6 Of these, one, two, or all are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (substituents are alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), R 4 , R 5 and R 6If one or two of these are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (with substituents being alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (may contain halogen elements), aryl groups having 6 to 20 carbon atoms, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, glycidyl groups, nitro groups, nitrile groups, sulfide groups, mercapto groups, sulfonyl groups, silyl groups, and hydrogen atoms. 4 , R 5 and R 6 They may be the same or different. A triazine derivative represented by, The process includes a crosslinking reaction step in which the mixture is reacted at 120-220°C in the presence of a dithiocarbamate-based catalyst. The ratio of the isocyanuric acid derivative represented by general formula (1) to the total of the isocyanuric acid derivative represented by general formula (1) and the triazine derivative represented by general formula (2) is 80.0 to 100.0% by mass. This is a method for producing a sulfur polymer characterized by the above. Hereinafter, the isocyanuric acid derivative represented by the general formula (1) will also be referred to as "compound (1)", and the triazine derivative represented by the general formula (2) will also be referred to as "compound (2)".

[0036] The crosslinking reaction step in the method for producing a sulfur polymer of the present invention is a step of reacting sulfur with an isocyanuric acid derivative represented by general formula (1), or an isocyanuric acid derivative represented by general formula (1) and a triazine derivative represented by general formula (2), in the presence of a catalyst at 120 to 220°C. In other words, in the crosslinking reaction step, (i) sulfur and an isocyanuric acid derivative represented by general formula (1) are reacted in the presence of a catalyst at 120 to 220°C, or (ii) sulfur and an isocyanuric acid derivative represented by general formula (1) and a triazine derivative represented by general formula (2) are reacted in the presence of a catalyst at 120 to 220°C.

[0037] In the crosslinking reaction process, the sulfur (sulfur molecule) used as a raw material usually exists as an S8 cyclic molecule. When the sulfur (sulfur molecule) used as a raw material is heated, or when heated and catalyzed, a portion of the molecular chain cleaves, causing ring opening, or further cleavage of the molecular chain after ring opening, resulting in a chain-like sulfur chain of 8 atoms or less. The sulfur (sulfur molecule) used as a raw material is not particularly limited and may be produced from any raw material and by any manufacturing method. The crystalline form of the sulfur is not particularly limited and may be α-sulfur (orthorhombic sulfur), β-sulfur (monoclinic sulfur), γ-sulfur (monoclinic sulfur), or a mixture thereof.

[0038] In the crosslinking reaction step, compound (1), or compound (1) and compound (2), are used as the crosslinking agent to react with sulfur.

[0039] In general formula (1), R 1 , R 2 and R 3 (i) to (iii) below is preferred. (i)R 1 , R 2 and R 3All of these are substituents that can react with sulfur, i.e., groups selected from the group consisting of linear or branched alkenyl groups (which may contain halogen elements) having 2 to 15 carbon atoms, preferably 2 to 10, and particularly preferably 3 carbon atoms; linear or branched alkynyl groups (which may contain halogen elements) having 2 to 15 carbon atoms; sulfide groups; mercapto groups; glycidyl groups; cyano groups; carbonyl groups; and linear or branched hydrocarbon groups (which may contain halogen elements) having 1 to 15 carbon atoms. (ii)R 1 , R 2 and R 3 Of these, two are substituents that can react with sulfur, i.e., linear or branched alkenyl groups having 2 to 15 carbon atoms, preferably 2 to 10, and particularly preferably 3 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2 to 15 carbon atoms (may contain halogen elements), sulfide groups, mercapto groups, glycidyl groups, cyano groups, carbonyl groups, and linear or branched hydrocarbon groups having 1 to 15 carbon atoms and containing halogens, and one is a group selected from the group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms (may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms (may contain halogen elements), and aryl groups, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, nitro groups, nitrile groups, sulfonyl groups, silyl groups, and hydrogen atoms having 6 to 20 carbon atoms, preferably 6 to 10. (iii)R 1 , R 2 and R 3One of these is a substituent that can react with sulfur, i.e., a group selected from the group consisting of a linear or branched alkenyl group having 2 to 15 carbon atoms, preferably 2 to 10, and particularly preferably 3 carbon atoms (may contain halogen elements), a linear or branched alkynyl group having 2 to 15 carbon atoms (may contain halogen elements), a sulfide group, a mercapto group, a glycidyl group, a cyano group, a carbonyl group, and a linear or branched hydrocarbon group having 1 to 15 carbon atoms and containing a halogen; and two of these are groups selected from the group consisting of a linear or branched alkyl group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms (may contain halogen elements), a linear or branched alkoxy group having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms (may contain halogen elements), and an aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, an amino group, an amide group, an imino group, a carboxyl group, a hydroxyl group, an ester group, a nitro group, a nitrile group, a sulfonyl group, a silyl group, and a hydrogen atom. Note, R 1 , R 2 and R 3 These may be the same or different. Furthermore, a substituent that can react with sulfur refers to a group that can react with sulfur by heating at 120-220°C in the presence of a dithiocarbamate catalyst in the crosslinking reaction step, and examples include linear or branched alkenyl groups (which may contain halogen elements) having 2 to 15 carbon atoms, preferably 120-220°C, linear or branched alkynyl groups (which may contain halogen elements) having 2 to 15 carbon atoms, preferably 2 to 10, sulfide groups, mercapto groups, glycidyl groups, cyano groups, carbonyl groups, and linear or branched hydrocarbon groups having 1 to 15 carbon atoms, preferably 1 to 10, that contain halogens. Furthermore, "may contain halogen elements" refers to both groups in which the hydrogen atoms of the group are not substituted with halogen atoms and groups in which some of the hydrogen atoms of the group are substituted with halogen atoms. For example, alkyl groups include methyl or chloromethyl groups; alkenyl groups include 2-propen-1-yl (allyl), 2-methyl-2-propen-1-yl, or 2-buten-1-yl groups; alkynyl groups include ethynyl groups; alkoxy groups include 2-hydroxyethyl groups; and mercapto groups include 2-mercaptoethyl groups.

[0040] As an isocyanuric acid derivative represented by general formula (1), see formula (1A):

[0041] [ka]

[0042] Examples of isocyanuric acid derivatives represented by general formula (1) include 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione. Also, examples of isocyanuric acid derivatives represented by general formula (1) include 1-(2-methyl-2-propen-1-yl)-3,5-di-2-propen-1-yl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1-methyl-3,5-di-2-propen-1-yl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3-di-2-buten-1-yl-5-methyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 1-(chloromethyl)-3,5-di-2-propen-1-yl-1,3,5-triazine-2, Examples include 4,6(1H,3H,5H)-trione, 1,3-di-2-buten-1-yl-5-methyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-triethinyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1-(2-hydroxyethyl)-3,5-di-2-propen-1-yl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and 1-(2-mercaptoethyl)-3,5-di-2-propyne-1-yl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione.

[0043] In general formula (2), R 4 , R5 and R 6 (i) to (iii) below is preferred. (i)R 4 , R 5 and R 6 All of these are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (with substituents being alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms). (ii)R 4 , R 5 and R 6 Of these, two are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (with substituents being alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), and one is a group selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms (may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms (may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms (may contain halogen elements), aryl groups having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, glycidyl groups, nitro groups, nitrile groups, sulfide groups, mercapto groups, sulfonyl groups, silyl groups, and hydrogen atoms. (iii)R 4 , R 5 and R 6One of these is an allyloxy group or a substituted allyloxy group having 4 to 15 carbon atoms (the substituent is an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms), and the other two are groups selected from the group consisting of a linear or branched alkyl group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms (may contain halogen elements), a linear or branched alkenyl group having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms (may contain halogen elements), a linear or branched alkynyl group having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms (may contain halogen elements), an aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, an amino group, an amide group, an imino group, a carboxyl group, a hydroxyl group, an ester group, a glycidyl group, a nitro group, a nitrile group, a sulfide group, a mercapto group, a sulfonyl group, a silyl group, and a hydrogen atom. Note, R 4 , R 5 and R 6 These may be the same or different. Furthermore, a substituted allyloxy group with 4 to 15 carbon atoms refers to a group in which the hydrogen atoms of the allyloxy group are substituted with an alkyl group with 1 to 4 carbon atoms or an aryl group with 6 to 10 carbon atoms. Furthermore, "may contain halogen elements" refers to both groups in which the hydrogen atoms of the group are not substituted with halogen atoms and groups in which some of the hydrogen atoms of the group are substituted with halogen atoms. For example, the allyloxy group is the 2-propene-1-yloxy group (allyloxy group), the alkyl group is the methyl group, the alkoxy group is the oxyethanol group, the aryl group is the phenyl group, and the glycidyl group is the 2-oxyranylmethoxy group.

[0044] Triazine derivatives represented by general formula (2) include the following formula (2A):

[0045] [ka]

[0046] Examples of triazine derivatives represented by general formula (2) include 2,4,6-tris(allyloxy)-1,3,5-triazine. Other examples of triazine derivatives represented by general formula (2) include 2-methyl-4,6-bis(2-propene-1-yloxy)-1,3,5-triazine, 2,4-bis(2-propene-1-yloxy)-6-(2-propyne-1-yloxy)-1,3,5-triazine, 2-[[4,6-bis(2-propene-1-yloxy)-1,3,5-triazine-2-yl]oxyethanol, 2-phenyl-4,6-bis(2-propene-1-yloxy)-1,3,5-triazine, and 2-(2-oxyranylmethoxy)-4,6-bis(2-propene-1-yloxy)-1,3,5-triazine.

[0047] In the crosslinking reaction step, the ratio of the isocyanuric acid derivative represented by general formula (1) to the total of the isocyanuric acid derivative represented by general formula (1) and the triazine derivative represented by general formula (2) ((compound (1) / (compound (1) + compound (2))) × 100) is 80.0 to 100.0% by mass, preferably 90.0 to 100.0% by mass, and more preferably 95.0 to 100.0% by mass. The ratio of compound (1) to the total of compound (1) and compound (2) is calculated based on the amount of compound (1) and compound (2) added to the raw material sulfur. Furthermore, if compound (1) or compound (2) is added to the raw material sulfur in multiple stages, the ratio of compound (1) to the total of compound (1) and compound (2) is calculated based on the total amount added in each stage.

[0048] In the crosslinking reaction step, it is preferable from the viewpoint of ease of operation and improved reproducibility to add the entire amount of compound (1), or compound (1) and compound (2), to the raw material sulfur before heating. However, if the effects of the present invention are not impaired, in the crosslinking reaction step, a portion of the amount of compound (1), or compound (1) and compound (2), may be added to the raw material sulfur before heating, and the remaining compound (1), or compound (1) and compound (2), may be added in one or more installments after heating has started.

[0049] In the crosslinking reaction step, the reaction of sulfur with compound (1), or compound (1) and compound (2), is carried out in the presence of a dithiocarbamate-based catalyst. In the crosslinking reaction step, by making the dithiocarbamate-based catalyst present during the reaction of sulfur with compound (1), or compound (1) and compound (2), the reaction of sulfur with compound (1), or compound (1) and compound (2), proceeds smoothly.

[0050] The dithiocarbamate-based catalyst is a salt of an anion represented by the general formula (3): R 7 R 8 NCS2 - (3) and a metal cation. In the general formula (3), R 7 and R 8 are linear or branched alkyl groups having 1 to 6 carbon atoms, preferably linear alkyl groups having 1 to 3 carbon atoms, and specifically include methyl, ethyl, propyl, etc. R 7 and R 8 may have the same structure or different structures. Examples of the metal cation that is the counter cation of the anion represented by the general formula (3) include zinc ion, sodium ion, silver ion, iron ion, ammonium ion, cobalt ion, nickel ion, copper ion, lithium ion, manganese ion, etc. Examples of the dithiocarbamate-based catalyst include zinc diethyldithiocarbamate, zinc dimethyldithiocarbamate, copper diethyldithiocarbamate, silver diethyldithiocarbamate, disodium dimethyldithiocarbamate, etc. Among these, zinc diethyldithiocarbamate and copper diethyldithiocarbamate are preferred.

[0051] In the crosslinking reaction step, sulfur is reacted with compound (1), or compound (1) and compound (2), at a temperature of 120 to 220°C, preferably 140 to 190°C, and particularly preferably 140 to 180°C. In the crosslinking reaction step, the reaction between sulfur and compound (1), or compound (1) and compound (2), proceeds well when the reaction temperature is within the above range. On the other hand, if the reaction temperature is below the above range, the crosslinking reaction will not occur or will hardly occur. If it exceeds the above range, a hydrogen atom abstraction reaction by sulfur radical species will occur, and there is a risk of a decomposition reaction accompanied by the generation of sulfides such as hydrogen sulfide.

[0052] In the crosslinking reaction step, the ratio of sulfur used as a raw material to compound (1), or compound (1) and compound (2), is not particularly limited and is appropriately selected depending on the amount of sulfur introduced into the sulfur polymer to be manufactured. In the crosslinking reaction step, the ratio of sulfur used as a raw material to compound (1), or compound (1) and compound (2), is preferably such that the mass ratio of sulfur to the total of sulfur, compound (1), and compound (2) is 50.0 to 95.0% by mass, more preferably 70.0 to 95.0% by mass, in terms of maximizing the amount of sulfur introduced.

[0053] In the crosslinking reaction step, the amount of dithiocarbamate catalyst used is not particularly limited, but in terms of ensuring a good reaction between sulfur and compound (1), or compound (1) and compound (2), the mass ratio of the dithiocarbamate catalyst to the total of compound (1) and compound (2) is preferably 0.1 to 5.0% by mass, more preferably 0.5 to 3.0% by mass.

[0054] In the crosslinking reaction step, the reaction time when sulfur is reacted with compound (1), or compound (1) and compound (2), is not particularly limited, but is preferably 0.5 to 24 hours, and particularly preferably 2 to 8 hours. In the crosslinking reaction step, the atmosphere when sulfur is reacted with compound (1), or compound (1) and compound (2), is an inert gas atmosphere such as nitrogen gas, helium gas, or argon gas.

[0055] In the crosslinking reaction step, crosslinking agents other than compound (1) and compound (2) can be used. An example of such a crosslinking agent is 1,3-diisopropenylbenzene. When using crosslinking agents other than compound (1) and compound (2), it is preferable that the mass ratio of the crosslinking agents other than compound (1) and compound (2) to the total of compound (1), compound (2), and the other crosslinking agents is 2.0% by mass or less. It is particularly preferable not to use crosslinking agents other than compound (1) and compound (2) in the crosslinking reaction step.

[0056] In the method for producing sulfur polymers of the present invention, after obtaining a sulfur polymer in the crosslinking reaction step, the obtained sulfur polymer can be washed with an organic solvent such as water, methanol, ethanol, diethyl ether, tetrahydrofuran, dimethylformamide, dichloromethane, ethyl acetate, hexane, carbon disulfide, or toluene, if necessary. The sulfur polymer may be washed under heating, for example, under reflux of an organic solvent.

[0057] In the method for producing sulfur polymers of the present invention, a dithiocarbamate-based catalyst is present during the crosslinking reaction step when sulfur reacts with compound (1), or compound (1) and compound (2), and the reaction temperature is set to 120 to 220°C, preferably 140 to 190°C, and particularly preferably 140 to 180°C, thereby enabling the production of sulfur polymers without the formation of phase separation products. Therefore, the method for producing sulfur polymers of the present invention can achieve a high yield of sulfur polymers.

[0058] On the other hand, if a catalyst is not used in the reaction between sulfur and compound (1) or compound (2), even if the reaction between sulfur and compound (1), or compound (1) and compound (2), is carried out at a temperature of 140°C or below, the reaction between sulfur and compound (1), or compound (1) and compound (2), will not occur or will occur with difficulty. Furthermore, if the reaction temperature is raised above 250°C without a catalyst, the reactivity increases, and the reaction between sulfur and compound (1), or compound (1) and compound (2), will proceed, but sulfides such as hydrogen sulfide will be formed as by-products, and some decomposition products will be produced.

[0059] In the sulfur polymer production method of the present invention, sulfur and compound (1) are heated at 120-220°C in the presence of a dithiocarbamate-based catalyst, thereby suppressing the decomposition reaction at high temperatures around 250°C. Therefore, it is presumed that in the sulfur polymer production method of the present invention, the generation of sulfide gas during the reaction is suppressed, and the resulting sulfur polymer is not excessively sticky, making it easy to recover. Furthermore, in the sulfur polymer production method of the present invention, when compound (2) is present in proportion to less than 20.0% by mass of the total of compound (1) and compound (2), and is heated with sulfur at 120-220°C in the presence of a dithiocarbamate-based catalyst, it is presumed that the triazine derivative (2) is converted to an isocyanuric acid derivative and reacts with sulfur.

[0060] The sulfur polymer obtained by the sulfur polymer production method of the present invention is obtained by crosslinking sulfur (sulfur molecules) using compound (1) or compound (2) as a crosslinking agent. Therefore, it has a molecular structure in which many sulfur chains, in which sulfur atoms are linked together in a chain, are connected by reaction residues of compound (1) or compound (2), which is the crosslinking agent. In other words, the sulfur polymer obtained by the sulfur polymer production method of the present invention has many sulfur chains and reaction residues of compound (1) or compound (2) that are bonded to multiple sulfur chains.

[0061] The method for producing the sulfur polymer of the present invention produces less sulfide gas as a by-product during the reaction of sulfur with compound (1), or compound (1) and compound (2), thus allowing for a high sulfur content in the resulting sulfur polymer. The sulfur content in the sulfur polymer obtained by the method for producing the sulfur polymer of the present invention is preferably 50.0% by mass or more, and particularly preferably 75.0 to 95.0% by mass. In particular, when the sulfur polymer of the present invention is used as a positive electrode material for lithium-sulfur batteries, the sulfur content in the sulfur polymer is preferably 75.0 to 95.0% by mass, and particularly preferably 85.0 to 95.0% by mass, in terms of battery performance.

[0062] In this invention, the sulfur content in the sulfur polymer is determined by elemental analysis. Therefore, when measuring the sulfur content in the sulfur polymer, the sulfur polymer after production is left to stand in an inert gas atmosphere until it reaches room temperature, and then the sample is finely ground using a pulverizer such as a mortar and pestle. This finely ground sample is used as the sample for elemental analysis. The number of measurements is set to N=5, and it is confirmed that the variation is sufficiently small, and the average value is taken as the sulfur content.

[0063] In the sulfur polymer production method of the present invention, the reaction sites of compound (1) or compound (2) increase due to the action of a dithiocarbamate-based catalyst, resulting in the formation of more CS bonds compared to the aforementioned Patent Document 1, which does not use a catalyst. When the sulfur polymer obtained by the sulfur polymer production method of the present invention is analyzed using X-ray photoelectron spectroscopy (XPS), the ratio of the peak area of ​​peak B, which has a peak top at around 286.3 eV and originates from CS, CO, and CN bonds, to the peak area of ​​peak A, which has a peak top at around 285 eV and originates from CC and CH bonds (B / A) is preferably 0.45 to 0.95, and particularly preferably 0.50 to 0.80.

[0064] In the present invention, the peak area ratio (B / A) by the above XPS analysis of the sulfur polymer is determined by XPS measurement. After confirming the elements by qualitative analysis (wide spectrum) of the outermost surface of the sample, multiple state analyses are performed for the target elements (C, N, O, S). Peak separation is carried out for the C1s spectrum. The C1s spectrum is assumed to have 3 to 4 components (near 285, 286, 288, 289.5 eV), and the value is obtained by calculating assuming that the full width at half maximum is the same for all.

[0065] The use of the sulfur polymer obtained by carrying out the production method of the sulfur polymer of the present invention is not particularly limited, and it is appropriately used for applications where the sulfur polymer can be used.

[0066] The sulfur polymer obtained by carrying out the production method of the sulfur polymer of the present invention is used, for example, as a positive electrode material for a lithium-sulfur secondary battery. That is, the method for producing a positive electrode material for a lithium-sulfur secondary battery of the present invention comprises sulfur and the general formula (1):

[0067] [Chemical formula]

[0068] (wherein, among R 1 , R 2 and R 3 , one, two or all are substituents capable of reacting with sulfur. The substituents capable of reacting with sulfur are a linear or branched alkenyl group having 2 to 15 carbon atoms (which may contain a halogen element), a linear or branched alkenyl group having 2 to 15 carbon atoms (which may contain a halogen element), a sulfide group, a mercapto group, a glycidyl group, a cyano group, a carbonyl group, and a linear or branched hydrocarbon group having 1 to 15 carbon atoms having a halogen, and are groups selected from the group consisting of; R 1 , R 2 and R 3If one or two of these are substituents that can react with sulfur, the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (which may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (which may contain halogen elements), and aryl groups, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, nitro groups, nitrile groups, sulfonyl groups, silyl groups, and hydrogen atoms having 6 to 20 carbon atoms. 1 , R 2 and R 3 They may be the same or different. An isocyanuric acid derivative represented by, or an isocyanuric acid derivative represented by the general formula (1) and the general formula (2):

[0069] [ka]

[0070] (In the formula, R 4 , R 5 and R 6 Of these, one, two, or all are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (substituents are alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), R 4 , R 5 and R 6If one or two of these are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (with substituents being alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (may contain halogen elements), aryl groups having 6 to 20 carbon atoms, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, glycidyl groups, nitro groups, nitrile groups, sulfide groups, mercapto groups, sulfonyl groups, silyl groups, and hydrogen atoms. 4 , R 5 and R 6 They may be the same or different. A triazine derivative represented by, The process includes a crosslinking reaction step in which the mixture is reacted at 120-220°C in the presence of a dithiocarbamate-based catalyst. The ratio of the isocyanuric acid derivative represented by general formula (1) to the total of the isocyanuric acid derivative represented by general formula (1) and the triazine derivative represented by general formula (2) is 80.0 to 100.0% by mass. This is a method for manufacturing the positive electrode material of a lithium-sulfur secondary battery, characterized by the following features.

[0071] The crosslinking reaction step in the method for producing the cathode material of the lithium-sulfur secondary battery of the present invention is the same as the crosslinking reaction step in the method for producing the sulfur polymer of the present invention. [Examples]

[0072] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples shown below.

[0073] (Example 1) Into a container made of polyfluoroalkoxy resin (PFA), 12.6 g of sulfur (manufactured by Kanto Chemical Co., Inc.), 1.4 g of TAIC (common name: triallyl isocyanurate, IUPAC name: 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, manufactured by Sigma-Aldrich Co., LLC), and 0.14 g of zinc diethyldithiocarbamate were weighed. Next, the raw materials were lightly mixed with a spatula, a stir bar was placed into the container, and heating was performed at 170 °C while stirring with a magnetic stirrer. When heating was performed for about 10 to 40 minutes, as the viscosity of the sample increased, the stir bar stopped. Thereafter, the stir bar was taken out from the system, and further mixing was performed with the back of a spatula for 6 to 10 minutes, and the whole changed to a gel state. Next, the gel was taken out from the oil bath and additionally heated in a constant temperature bath with a nitrogen atmosphere set at 140 °C for 6 hours to obtain a sulfur polymer.

[0074] (Comparative Example 1) Into a container made of polyfluoroalkoxy resin (PFA), 12.6 g of sulfur (manufactured by Kanto Chemical Co., Inc.) was weighed. While stirring with a magnetic stirrer, the temperature was raised to 175 to 185 °C to obtain liquid sulfur, and after adding 1.4 g of TAIC (common name: triallyl isocyanurate, IUPAC name: 1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, manufactured by Sigma-Aldrich Co., LLC) to the liquid sulfur, the reaction was allowed to proceed by holding at that temperature for 6 hours. After the obtained material was pulverized, it was heat-treated at 250 °C in an inert gas atmosphere. The heating rate during the heat treatment was 2 to 5 °C / min, and subsequently, it was held at 250 °C for 4 hours to cause a copolymerization reaction between sulfur and a crosslinking agent to obtain a sulfur polymer.

[0075] <Analysis method of sulfur content> For sulfur analysis, the obtained sample was pulverized and measured using SC832DR manufactured by LECO Corporation. For the comparative example, it was washed with carbon disulfide, then filtered using a Kinoshita funnel, dried under reduced pressure, and then analyzed.

[0076] <Analysis method of ratio (B / A) of peak areas by X-ray photoelectron spectroscopy (XPS)> Measurements were taken using an ULVAC-PHI PHI-QuanteraII scanning X-ray photoelectron spectrometer under the following conditions: X-ray source Al Kα, monochromatic, 1486.6 eV, 25 W, analysis area 1.0 × 0.4 mm. 2 The analysis was performed using a charge neutralization mechanism (electron neutralization + ion gun). The sample was placed in an aluminum dish, fixed to a measurement holder, and introduced into the XPS instrument. For the XPS measurement, after confirming the elements by qualitative analysis (wide spectrum) of the outermost surface of the sample, multiple state analyses were performed for the elements of interest (C, N, O, S). For the horizontal axis correction of the spectrum, O1s was adopted as the horizontal axis correction because it showed good agreement with the O1s spectrum and it was thought that the state change of S relative to the main carbon skeleton could be detected. Peak separation was performed on the C1s spectrum. The C1s spectrum consisted of 3-4 components (around 285, 286, 288, and 289.5 eV), and the full width at half maximum was calculated assuming that all components had the same width at half maximum. For the above C1s spectrum, the peak area of ​​peak A, which has its peak top at around 285 eV and originates from CC and CH bonds, and the peak area of ​​peak B, which has its peak top at around 286.3 eV and originates from CS, CO, and CN bonds, were measured. Then, the ratio of the peak areas (B / A) was calculated.

[0077] (result) <Example 1> The sulfur polymer from Example 1 could be easily recovered from the reaction vessel without phase separation. The yield of the sulfur polymer was approximately 95%. The sulfur content was 90.0% by mass. As shown in Figure 1, the peak area ratio (B / A) by X-ray photoelectron spectroscopy (XPS) was 0.604.

[0078] <Comparative Example 1> In Comparative Example 1, the sulfur polymer exhibited extremely high adhesion to the container, and although attempts were made to recover it from the reaction vessel, it was not possible to completely recover the adhered material. As a result, the yield of the sulfur polymer was approximately 40%. The sulfur content was 93.0% by mass. As shown in Figure 2, the peak area ratio (B / A) by X-ray photoelectron spectroscopy (XPS) was 0.0759.

[0079] Next, the sulfur battery performance test of Example 1 was conducted as follows. <Fabrication of electrodes and coin cells using sulfur polymers, and charge / discharge testing> Sulfur polymer, acetylene black (Denka Black HS-100), a conductive additive, and a binder (carboxymethylcellulose sodium (CMC) (Daicel Corporation, product code 2200)) were measured out in a mass ratio of 6:3:1. The sulfur polymer and conductive additive were placed in an agate mortar and mixed, and then the binder was added and mixed further. Next, pure water was added in two batches and mixed in the mortar. The prepared sample was mixed in a rotation / revolution mixer (2000 rpm, 3 min) to obtain a slurry. The electrode was coated onto aluminum foil to a thickness of 200 μm and dried overnight at 40°C. The obtained electrode was punched out with a φ16 die. The punched electrode was pressed using a uniaxial press to reduce the porosity to approximately 30-40%. The fabricated electrode was placed in a glass tube oven and vacuum dried at 50°C for 14 hours. Coin cells (CR2032) were fabricated by assembling electrodes made from lithium foil, polyolefin separators, and sulfur polymer in a glove box filled with high-purity argon. The electrolyte used was 1M LiTFSI (Kishida Chemical Co., Ltd.) / 0.1M LiNO3 (Kanto Chemical Co., Ltd.) dissolved in 1,3-dioxane (Sigma-Aldrich Co., Ltd.) / 1,2-dimethoxyethane (Kishida Chemical Co., Ltd.). Electrochemical measurements were performed using Hokuto Denko Co., Ltd.'s HJ1001SD8. Constant current discharge / charge voltages were measured at 0.05C (1C-1670mAh / g) between 1.0 and 3.0V at 25°C. All discharge / charge capacities were calculated based on the weight of sulfur.

[0080] <Battery performance evaluation> From the charge-discharge curve shown in Figure 3 and the charge-discharge graph shown in Figure 4, it was confirmed that the sulfur polymer of Example 1 has sufficient performance to function as a positive electrode material for a lithium-sulfur secondary battery.

Claims

1. Sulfur and, The following general formula (1): 【Chemistry 1】 (wherein, R １ , R ２ and R ３ among them, one, two or all are substituents capable of reacting with sulfur, and the substituent capable of reacting with sulfur is a linear or branched alkenyl group having 2 to 15 carbon atoms (which may contain a halogen element), a linear or branched alkenyl group having 2 to 15 carbon atoms (which may contain a halogen element), a sulfide group, a mercapto group, a glycidyl group, a cyano group, a carbonyl group, and a linear or branched hydrocarbon group having 1 to 15 carbon atoms having a halogen, which is a group selected from the group consisting of; R １ , R ２ and R ３ among them, when one or two are substituents capable of reacting with sulfur, the rest are a linear or branched alkyl group having 1 to 15 carbon atoms (which may contain a halogen element), a linear or branched alkoxy group having 2 to 15 carbon atoms (which may contain a halogen element), an aryl group having 6 to 20 carbon atoms, an amino group, an amide group, an imino group, a carboxyl group, a hydroxyl group, an ester group, a nitro group, a nitrile group, a sulfonyl group, a silyl group, and a hydrogen atom, which is a group selected from the group consisting of. Incidentally, R １ , R ２ and R ３ may be the same or different.) An isocyanuric acid derivative represented by the above general formula (1) and the following general formula (2): 【Chemistry 2】 (In the formula, R ４ , R ５ and R ６ Of these, one, two, or all are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (substituents are alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), R ４ , R ５ and R ６ If one or two of these are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (with substituents being alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (may contain halogen elements), aryl groups having 6 to 20 carbon atoms, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, glycidyl groups, nitro groups, nitrile groups, sulfide groups, mercapto groups, sulfonyl groups, silyl groups, and hydrogen atoms. ４ , R ５ and R ６ They may be the same or different. A triazine derivative represented by, The process includes a crosslinking reaction step in which the mixture is reacted at 120-220°C in the presence of a dithiocarbamate-based catalyst. The ratio of the isocyanuric acid derivative represented by general formula (1) to the total of the isocyanuric acid derivative represented by general formula (1) and the triazine derivative represented by general formula (2) is 80.0 to 100.0% by mass. A method for producing sulfur polymers characterized by the following.

2. The isocyanuric acid derivative represented by the general formula (1) is given by the following formula (1A): 【Transformation 3】 The triazine derivative represented by the general formula (2) is a 1,3,5-trialyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and the triazine derivative represented by the general formula (2) is the following formula (2A): 【Chemistry 4】 A method for producing a sulfur polymer according to claim 1, characterized in that it is 2,4,6-tris(allyloxy)-1,3,5-triazine represented by .

3. The method for producing a sulfur polymer according to claim 1, characterized in that the dithiocarbamate-based catalyst is zinc diethyldithiocarbamate.

4. The method for producing a sulfur polymer according to claim 1, characterized in that the sulfur content in the sulfur polymer is 50.0% by mass or more.

5. The method for producing the sulfur polymer according to claim 1, characterized in that, when the sulfur polymer is analyzed using X-ray photoelectron spectroscopy (XPS), the ratio (B / A) of the peak area of ​​peak B, which has a peak top at approximately 286.3 eV and originates from C-S, C-O, and C-N bonds, to the peak area of ​​peak A, which has a peak top at approximately 285 eV and originates from C-C and C-H bonds, is 0.40 to 0.

95.

6. The method for producing a sulfur polymer according to claim 1, characterized in that the sulfur polymer is a sulfur polymer used as a positive electrode material for a lithium-sulfur secondary battery.

7. Sulfur and, The following general formula (1): 【Transformation 5】 (In the formula, R １ , R ２ and R ３ Of these, one, two, or all are substituents that can react with sulfur, and the substituents that can react with sulfur are groups selected from the group consisting of linear or branched alkenyl groups having 2 to 15 carbon atoms (which may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (which may contain halogen elements), sulfide groups, mercapto groups, glycidyl groups, cyano groups, carbonyl groups, and linear or branched hydrocarbon groups having 1 to 15 carbon atoms and containing halogens, R １ , R ２ and R ３ If one or two of these are substituents that can react with sulfur, the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (which may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (which may contain halogen elements), and aryl groups, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, nitro groups, nitrile groups, sulfonyl groups, silyl groups, and hydrogen atoms having 6 to 20 carbon atoms. １ , R ２ and R ３ They may be the same or different. An isocyanuric acid derivative represented by the above general formula (1) and the following general formula (2): 【Transformation 6】 (In the formula, R ４ , R ５ and R ６ Of these, one, two, or all are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (substituents are alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), R ４ , R ５ and R ６ If one or two of these are allyloxy groups or substituted allyloxy groups having 4 to 15 carbon atoms (with substituents being alkyl groups having 1 to 4 carbon atoms or aryl groups having 6 to 10 carbon atoms), the remaining group is selected from the group consisting of linear or branched alkyl groups having 1 to 15 carbon atoms (may contain halogen elements), linear or branched alkenyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2 to 15 carbon atoms (may contain halogen elements), linear or branched alkoxy groups having 2 to 15 carbon atoms (may contain halogen elements), aryl groups having 6 to 20 carbon atoms, amino groups, amide groups, imino groups, carboxyl groups, hydroxyl groups, ester groups, glycidyl groups, nitro groups, nitrile groups, sulfide groups, mercapto groups, sulfonyl groups, silyl groups, and hydrogen atoms. ４ , R ５ and R ６ They may be the same or different. A triazine derivative represented by, The process includes a crosslinking reaction step in which the mixture is reacted at 120-220°C in the presence of a dithiocarbamate-based catalyst. The ratio of the isocyanuric acid derivative represented by general formula (1) to the total of the isocyanuric acid derivative represented by general formula (1) and the triazine derivative represented by general formula (2) is 80.0 to 100.0% by mass. A method for manufacturing a positive electrode material for lithium-sulfur secondary batteries, characterized by the above.

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