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 a triazine derivative, using the triazine derivative as a crosslinker, which can suppress generation of phase-separated substances.SOLUTION: A method for producing a sulfur polymer includes a crosslinking reaction step for reacting sulfur with a triazine derivative represented by a general formula (1), or the triazine derivative represented by the general formula (1) or an isocyanuric acid 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 triazine derivative represented by the general formula (1) or the isocyanuric acid derivative represented by the general formula (2), the triazine derivative represented by the general formula (1) is 20.0-100.0 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 lithium sulfur batteries, for example, Patent Document 1 discloses a positive electrode active material for lithium sulfur batteries that includes a poly(S-co-triallyloxy-triazine) vulcanized polymer obtained by reacting sulfur with triallyloxy-triazine. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Korean Patent Publication No. 10-2103799 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Patent Document 1 describes a method for producing a sulfur polymer using triallyloxy-triazine as a crosslinking agent. However, the present inventors have found that when sulfur and triallyloxy-triazine are heated and reacted, a sulfur polymer is obtained, but a liquid by-product separates from the sulfur polymer at the end of the reaction.

[0007] The liquid product produced by phase separation is a low-molecular-weight substance containing sulfur atoms and a crosslinking agent, and also contains a large amount of unreacted sulfur atoms and crosslinking agent. When such unreacted crosslinking agent is produced, the reaction with the crosslinking agent is insufficient, and the amount of sulfur introduced into the sulfur polymer decreases. Furthermore, when used as a battery cathode material, these low-molecular-weight crosslinking agents that were not used for crosslinking with sulfur bleed out (dissolve) into the electrolyte, making them unsuitable for use as an active material. For this reason, the method in Patent Document 1 required washing the synthesized sample with carbon disulfide to remove soluble components. However, this washing also partially removes the sulfur polymer, raising concerns about a decrease in yield.

[0008] Therefore, the object of the present invention is to provide a method for producing a sulfur polymer by reacting sulfur with a triazine derivative using a triazine derivative as a crosslinking agent, the method for producing a sulfur polymer that can suppress the formation of phase separation products, and a method for producing a positive electrode material for lithium sulfur secondary batteries. [Means for solving the problem]

[0009] As a result of diligent research, the present inventors discovered that by reacting sulfur with a triazine derivative, or a triazine derivative and an isocyanuric acid derivative, under a specific catalyst and within a specific temperature range, phase separation at the end of the reaction can be suppressed, and a homogeneous sulfur polymer can be obtained, thus completing the present invention.

[0010] In other words, the present invention (1) is a combination of sulfur and The following general formula (1):

[0011] [Chemical formula]

[0012] (wherein, R 1 , R 2 and R 3 among them, one, two or all are allyloxy groups or substituted allyloxy groups 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 R 1 , R 2 and R 3 among them, when one or two are allyloxy groups or substituted allyloxy groups 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), the remainder is a linear or branched alkyl group having 1 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 linear or branched alkynyl group having 2 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 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 that R 1 , R 2 and R 3 may be the same or different.) A triazine derivative represented by, or the triazine derivative represented by the general formula (1) and the following general formula (2):[[ID=三十二]]

[0013] [Chemical formula]

[0014] (wherein, R 4 , R 5 and R 6Of 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 alkynyl 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 4 , R 5 and R 6 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. 4 , R 5 and R 6 They may be the same or different. An isocyanuric acid 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 triazine derivative represented by general formula (1) to the total of the triazine derivative represented by general formula (1) and the isocyanuric acid derivative represented by general formula (2) is 20.0 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 triazine derivative represented by the general formula (1) is the following formula (1A):

[0016] [ka]

[0017] The isocyanuric acid derivative represented by the general formula (2) is 2,4,6-tris(allyloxy)-1,3,5-triazine, and is also represented by the following formula (2A):

[0018] [ka]

[0019] The present invention provides a method for producing the sulfur polymer of (1), characterized by being a 1,3,5-trialyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione 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 50.0% by mass or more.

[0022] Furthermore, the present invention (5) provides a method for producing any of the sulfur polymers (1) to (4), characterized in that the sulfur polymer is a sulfur polymer used as a positive electrode material for a lithium-sulfur secondary battery.

[0023] Furthermore, the present invention (6) involves sulfur and The following general formula (1):

[0024] [ka]

[0025] (In the formula, R 1 , R 2 and R 3Of 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 1 , R 2 and R 3 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. 1 , R 2 and R 3 They may be the same or different. A triazine derivative represented by the above general formula (1) and the following general formula (2):

[0026] [ka]

[0027] (In the formula, R 4 , R 5 and R 6 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 alkynyl 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, R4 , R 5 and R 6 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. 4 , R 5 and R 6 They may be the same or different. An isocyanuric acid 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 triazine derivative represented by general formula (1) to the total of the triazine derivative represented by general formula (1) and the isocyanuric acid derivative represented by general formula (2) is 20.0 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]

[0028] According to the present invention, a method for producing a sulfur polymer is provided, which involves reacting sulfur with a triazine derivative using a triazine derivative as a crosslinking agent, and which can suppress the formation of phase separation products at the end of the reaction. The present invention also provides a method for producing a positive electrode material for a lithium-sulfur secondary battery. [Brief explanation of the drawing]

[0029] [Figure 1] Figure 1 shows the 13C-MAS-NMR spectrum of the sulfur polymer obtained in Example 1. [Figure 2] Figure 2 shows the 13C-MAS-NMR spectrum of the sulfur polymer obtained in Example 2. [Figure 3]Figure 3 shows the 13C-MAS-NMR spectrum of the sulfur polymer obtained in Comparative Example 1. [Figure 4] Figure 4 shows the charge-discharge curve of the sulfur polymer in Example 1. [Figure 5] Figure 5 shows the charge-discharge graph (10 cycles) of the electrode fabricated using the sulfur polymer of Example 1. [Figure 6] Figure 6 shows the charge-discharge curve of the sulfur polymer in Example 2. [Figure 7] Figure 7 shows the charge-discharge graph (10 cycles) of the electrode fabricated using the sulfur polymer of Example 2. [Modes for carrying out the invention]

[0030] The present invention provides a method for producing a sulfur polymer using sulfur, The following general formula (1):

[0031] [ka]

[0032] (In the formula, R 1 , R 2 and R 3 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 1 , R 2 and R 3If 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. 1 , R 2 and R 3 They may be the same or different. A triazine derivative represented by the above general formula (1) and the following general formula (2):

[0033] [ka]

[0034] (In the formula, R 4 , R 5 and R 6 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 alkynyl 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 4 , R 5 and R 6If 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. 4 , R 5 and R 6 They may be the same or different. An isocyanuric acid 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 triazine derivative represented by general formula (1) to the total of the triazine derivative represented by general formula (1) and the isocyanuric acid derivative represented by general formula (2) is 20.0 to 100.0% by mass. This is a method for producing a sulfur polymer characterized by the above. Hereinafter, the triazine derivative represented by the general formula (1) will also be referred to as "compound (1)", and the isocyanuric acid derivative represented by the general formula (2) will also be referred to as "compound (2)".

[0035] The crosslinking reaction step in the method for producing a sulfur polymer of the present invention is a step of reacting sulfur with a triazine derivative represented by general formula (1), or a triazine derivative represented by general formula (1) and an isocyanuric acid 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 a triazine derivative represented by general formula (1) are reacted in the presence of a catalyst at 120 to 220°C, or (ii) sulfur and a triazine derivative represented by general formula (1) and an isocyanuric acid derivative represented by general formula (2) are reacted in the presence of a catalyst at 120 to 220°C.

[0036] 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.

[0037] In the crosslinking reaction step, compound (1), or compound (1) and compound (2), are used as the crosslinking agent to react with sulfur.

[0038] In general formula (1), R 1 , R 2 and R 3 (i) to (iii) below is preferred. (i)R 1 , R 2 and R 3 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 1 , R 2 and R 3Of 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 1 , R 2 and R 3 One 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 1 , R 2 and R 3These 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.

[0039] Triazine derivatives represented by general formula (1) include the following formula (1A):

[0040] [ka]

[0041] Examples of triazine derivatives represented by general formula (1) include 2,4,6-tris(allyloxy)-1,3,5-triazine. Other examples of triazine derivatives represented by general formula (1) 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.

[0042] In general formula (2), R 4 , R 5 and R 6 (i) to (iii) below is preferred. (i)R 4 , R5 and R 6 All 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 having 1 to 15 carbon atoms and containing halogens. (ii)R 4 , R 5 and R 6 Of these, two 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, preferably 1 to 10 carbon atoms; linear or branched alkoxy groups (which may contain halogen elements) having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms; and groups selected from the group consisting of 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 carbon atoms. (iii)R 4 , R 5 and R 6One of these is a substituent that can react with sulfur, i.e., a group 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, preferably 1 to 10 carbon atoms; linear or branched alkoxy groups (which may contain halogen elements) having 2 to 15 carbon atoms, preferably 2 to 10 carbon atoms; and aryl groups (which may contain halogen elements) having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms; amino groups; amide groups; imino groups; carboxyl groups; hydroxyl groups; ester groups; nitro groups; nitrile groups; sulfonyl groups; silyl groups; and hydrogen atoms. Note, R 4 , R 5 and R 6 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 having 2-15 carbon atoms, preferably 2-10 carbon atoms (may contain halogen elements), linear or branched alkynyl groups having 2-15 carbon atoms, preferably 2-10 carbon atoms (may contain halogen elements), sulfide groups, mercapto groups, glycidyl groups, cyano groups, carbonyl groups, and linear or branched hydrocarbon groups having 1-15 carbon atoms, preferably 1-10 carbon atoms and containing 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.

[0043] As an isocyanuric acid derivative represented by general formula (2), see formula (2A):

[0044] [ka]

[0045] Examples of isocyanuric acid derivatives represented by general formula (2) 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 (2) 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.

[0046] In the crosslinking reaction step, the ratio of the triazine derivative represented by the general formula (1) to the total of the triazine derivative represented by the general formula (1) and the isocyanuric acid derivative represented by the general formula (2) ((Compound (1) / (Compound (1) + Compound (2))) × 100) is 20.0 to 100.0% by mass, preferably 50.0 to 100% by mass, more preferably 80.0 to 100% by mass. The ratio of Compound (1) to the total of Compound (1) and Compound (2) is a value calculated based on the addition amounts of Compound (1) and Compound (2) added to the sulfur in the raw material. Further, when Compound (1) or Compound (2) is added to the sulfur in the raw material in multiple portions, the ratio of Compound (1) to the total of Compound (1) and Compound (2) is calculated based on the total addition amounts of each.

[0047] In the crosslinking reaction step, it is preferable to add all of Compound (1) or the total amounts of Compound (1) and Compound (2) to the sulfur in the raw material before heating from the viewpoints of simplicity of the process and improvement of reproducibility. However, as long as the effects of the present invention are not impaired, in the crosslinking reaction step, a part of Compound (1) or the total amounts of Compound (1) and Compound (2) may be added to the sulfur in the raw material before heating, and after the start of heating, the remaining Compound (1) or Compound (1) and Compound (2) may be added in one or multiple portions.

[0048] In the crosslinking reaction step, the reaction between sulfur and Compound (1) or Compound (1) and Compound (2) is carried out in the presence of a dithiocarbamate-based catalyst. By making the dithiocarbamate-based catalyst present during the reaction between sulfur and Compound (1) or Compound (1) and Compound (2) in the crosslinking reaction step, the reaction between sulfur and Compound (1) or Compound (1) and Compound (2) proceeds smoothly.

[0049] 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 R8 R is a linear or branched alkyl group having 1 to 6 carbon atoms, preferably a linear alkyl group having 1 to 3 carbon atoms, specifically including methyl, ethyl, and propyl. 7 and R 8 These may have the same structure or different structures. Examples of metal cations that are countercations of the anion represented by general formula (3) include zinc ions, sodium ions, silver ions, iron ions, ammonium ions, cobalt ions, nickel ions, copper ions, lithium ions, and manganese ions. Examples of dithiocarbamate catalysts include zinc diethyldithiocarbamate, zinc dimethyldithiocarbamate, copper diethyldithiocarbamate, silver diethyldithiocarbamate, and disodium dimethyldithiocarbamate, of which zinc diethyldithiocarbamate and copper diethyldithiocarbamate are preferred.

[0050] 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.

[0051] 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 sulfur content in the sulfur polymer to be manufactured. The ratio of sulfur used as a raw material to compound (1), or compound (1) and compound (2), in the crosslinking reaction step 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 having a high sulfur content.

[0052] 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.

[0053] 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.

[0054] In the crosslinking reaction step, crosslinking agents other than compound (1) and compound (2) can be used. Examples of such crosslinking agents include 1,3-diisopropenylbenzene. When crosslinking agents other than compound (1) and compound (2) are used, 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 preferably 2.0% by mass or less. In particular, it is especially preferable not to use crosslinking agents other than compound (1) and compound (2) in the crosslinking reaction step.

[0055] 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.

[0056] In the present invention's method for producing sulfur polymers, a dithiocarbamate-based catalyst is present during the crosslinking reaction step between sulfur and compound (1), or compound (1) and compound (2), and the reaction temperature is set to 120-220°C. This allows for the production of sulfur polymers without the formation of phase separation products. Therefore, the present invention's method for producing sulfur polymers can achieve a high yield of sulfur polymers.

[0057] 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 below 120°C, the reaction between sulfur and compound (1), or compound (1) and compound (2), will not occur or will occur with difficulty. Also, if the reaction temperature is raised above 220°C without a catalyst, the reactivity increases, and although the reaction between sulfur and compound (1), or compound (1) and compound (2), proceeds, sulfides such as hydrogen sulfide are produced as by-products during the reaction.

[0058] In the present invention's method for producing sulfur polymers, when sulfur and compound (1), or compound (1) and compound (2), are heated at 120-220°C, preferably 140-200°C, and particularly preferably 150-190°C, in the presence of a dithiocarbamate-based catalyst, it is presumed that compound (1) is converted to compound (2) and reacts with sulfur. The inventors have found that compound (2) reacts with sulfur without producing phase separation products, while compound (1) readily produces phase separation products when reacting with sulfur. Therefore, when no catalyst is used, if the amount of compound (1) in the crosslinking agent is too high, specifically if (compound (1) / (compound (1) + compound (2))) × 100 is 20.0-100.0% by mass, phase separation products will be produced. Therefore, in the method for producing sulfur polymers of the present invention, by heating compound (1) at 120 to 220°C, preferably 140 to 190°C, and particularly preferably 140 to 180°C, in the presence of a dithiocarbamate-based catalyst, compound (1) changes into compound (2), which is less likely to produce phase separation products, during the reaction and reacts with sulfur. Thus, it is presumed that even if the proportion of compound (1) added to the sulfur is large, phase separation products are less likely to be produced.

[0059] 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.

[0060] The method for producing the sulfur polymer of the present invention allows for the reaction of sulfur with compound (1), or compound (1) and compound (2), without generating phase separation products, thus enabling 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, a sulfur content of 75.0 to 95.0% by mass in the sulfur polymer is preferable in terms of battery performance.

[0061] 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.

[0062] The sulfur polymer obtained by the sulfur polymer production method of the present invention is not particularly limited in its use and can be used as appropriate in any application where sulfur polymers can be used.

[0063] The sulfur polymer obtained by the sulfur polymer manufacturing method of the present invention can be used, for example, as a positive electrode material for a lithium-sulfur secondary battery. In other words, the method for manufacturing a positive electrode material for a lithium-sulfur secondary battery of the present invention involves sulfur and The above general formula (1):

[0064] [ka]

[0065] (In the formula, R 1 , R 2 and R 3 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), R1 , R 2 and R 3 Among them, when one or two of them are 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), the remainder is a linear or branched alkyl group having 1 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 linear or branched alkynyl group having 2 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 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 that R 1 , R 2 and R 3 may be the same or different.) A triazine derivative represented by, or the triazine derivative represented by the general formula (1) and the general formula (2):

[0066] [Chemical formula]

[0067] (In the formula, R 4 , R 5 and R 6 Among them, one, two or all of them are substituents capable of reacting with sulfur, and 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 alkynyl 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 4 , R 5 and R 6If 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. 4 , R 5 and R 6 They may be the same or different. An isocyanuric acid 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 triazine derivative represented by general formula (1) to the total of the triazine derivative represented by general formula (1) and the isocyanuric acid derivative represented by general formula (2) is 20.0 to 100.0% by mass. This is a method for manufacturing a positive electrode material for lithium-sulfur secondary batteries, characterized by the following features.

[0068] The crosslinking reaction step in the method for producing a positive electrode material for lithium-sulfur secondary batteries of the present invention is the same as the crosslinking reaction step in the method for producing a sulfur polymer of the present invention. [Examples]

[0069] The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples shown below.

[0070] (Example 1) 12.6 g of sulfur (manufactured by Kanto Chemical Co., Ltd.), 1.4 g of TAOT (2,4,6-tris(allyloxy)-1,3,5-triazine, manufactured by Sigma-Aldrich), and 0.14 g of zinc diethyldithiocarbamate were weighed into a polyfluoroalkoxy resin (PFA) container. The raw materials were then lightly mixed with a spatula, a stirring bar was placed in the container, and the mixture was heated at 170°C while stirring with a magnetic stirrer. After heating for about 10 to 30 minutes, the stirring bar stopped due to an increase in the viscosity of the sample. The stirring bar was then removed from the system, and the mixture was further mixed with a spatula for 6 to 10 minutes until the entire mixture turned into a gel. The gel was then removed from the oil bath and heated for an additional 6 hours in a constant temperature bath with a nitrogen atmosphere set to 140°C, after which it was cooled and dried at room temperature and atmospheric pressure to obtain a sulfur polymer.

[0071] (Example 2) 11.9 g of sulfur (manufactured by Kanto Chemical Co., Ltd.), 2.1 g of TAOT (2,4,6-tris(allyloxy)-1,3,5-triazine, manufactured by Sigma-Aldrich), and 0.14 g of zinc diethyldithiocarbamate were weighed into a polyfluoroalkoxy resin (PFA) container. The raw materials were then lightly mixed with a spatula, a stirring bar was placed in the container, and the mixture was heated at 170°C while stirring with a magnetic stirrer. After heating for about 10 to 30 minutes, the stirring bar stopped due to an increase in the viscosity of the sample. The stirring bar was then removed from the system, and the mixture was further mixed with a spatula for 6 to 10 minutes until the entire mixture turned into a gel. The gel was then removed from the oil bath and heated for an additional 6 hours in a constant temperature bath with a nitrogen atmosphere set to 140°C, after which it was cooled and dried at room temperature and atmospheric pressure to obtain a sulfur polymer.

[0072] (Comparative Example 1) 12.6 g of sulfur (manufactured by Kanto Chemical Co., Inc.) was weighed into a container made of polyfluoroalkoxy resin (PFA). A stir bar was placed in the container, and while stirring with a magnetic stirrer, the internal temperature was adjusted to 160 °C and heated. When the solid sulfur (yellow) changed to molten sulfur (orange), 1.4 g of TAOT (2,4,6-tris(allyloxy)-1,3,5-triazine, manufactured by Sigma-Aldrich) was slowly added. After stirring for about 10 minutes, the mixture changed to a homogeneous phase. Thereafter, heating was continued for 3 hours. During the heating, a phase that polymerized and changed to a solid and a phase that remained liquid were confirmed. After a predetermined time had elapsed, the container was taken out of the reaction system and quenched with liquid nitrogen. For all the obtained polymers, unreacted sulfur was washed with carbon disulfide, then filtered off using a Kiriyama funnel, and dried under reduced pressure.

[0073] < 13 C-MAS-NMR measurement method> For the sulfur polymers obtained in Example 1, Example 2 and Comparative Example 1, using a nuclear magnetic resonance (NMR) apparatus (ECA400, manufactured by JEOL Ltd.), rotor type: zirconia (Φ4 mm), MAS speed: 15 kHz, pulse sequence: CP, repetition time: 5 s, number of integrations: 46000 times, and adamantane was used as the chemical shift standard 13 C-MAS-NMR measurement was performed.

[0074] <Phase separation evaluation method> After heating at a predetermined temperature and time, visually, in addition to the sulfur polymer, it was confirmed whether or not a liquid substance was present.

[0075] <Analysis method for sulfur content> For sulfur analysis, the obtained sample was pulverized and measured using an SC832DR manufactured by LECO.

[0076] <X-ray photoelectron spectroscopy (XPS) measurement method> Using a PHI-QuanteraII scanning X-ray photoelectron spectrometer manufactured by ULVAC-PHI, measurement conditions: X-ray source Al Kα, monochromator 1486.6 eV, 25 W, analysis area 1.0 × 0.4 mm 2It was carried out under the conditions of using a charge neutralization mechanism (electronic neutralization + ion gun). The sample was fixed to a measurement holder with an Al dish and introduced into the XPS apparatus. After confirming the elements by qualitative analysis (wide spectrum) of the outermost surface of the sample, multiple state analyses were performed on the target elements (C, N, O, S).

[0077] (Results) <Phase separation evaluation> In Example 1 and Example 2, no liquid substance that phase-separates from the obtained sulfur polymer was confirmed at the end of the reaction. Therefore, in Example 1 and Example 2, phase separation was not observed. On the other hand, in Comparative Example 1, a liquid substance that was phase-separated from the obtained sulfur polymer was confirmed at the end of the reaction. Therefore, in Comparative Example 1, a phase-separated product was formed.

[0078] < 13 <C-MAS-NMR measurement results> Figures 1 to 3 are the 13 C-MAS-NMR spectra of the sulfur polymers obtained in Example 1, Example 2, and Comparative Example 1, respectively. The chemical shift value near 174 ppm is a peak specific to TAOT (2,4,6-tris(allyloxy)-1,3,5-triazine), and the peak near 149 ppm is a peak specific to TAIC (1,3,5-triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione). In Example 1 and Example 2, unlike Comparative Example 1, the peak of TAIC is clearly more. In Example 1 and Example 2, it is considered that TAOT has changed to TAIC. Therefore, it is considered that the obtained sulfur polymers in Example 1 and Example 2 are different from those in Comparative Example 1.

[0079] <X-ray photoelectron spectroscopy (XPS) measurement results> In Comparative Example 1, a peak with a peak top around 288.6 eV is present, which is thought to originate from the CO bond of the allyl ether. However, no such peak is present in Examples 1 and 2, suggesting that TAOT has been converted to TAIC. Therefore, the XPS measurement results also indicate that the sulfur polymers obtained in Examples 1 and 2 are different from those obtained in Comparative Example 1.

[0080] <Sulfur content> The sulfur content of the sulfur polymer in Example 1 was 87.5% by mass, the sulfur content of the sulfur polymer in Example 2 was 83.1% by mass, and the sulfur content of the sulfur polymer in Comparative Example 1 was 85.0% by mass.

[0081] <Yield> The yield of the sulfur polymer in Examples 1 and 2 was approximately 95%. The yield of the sulfur polymer in Comparative Example 1 was approximately 30%.

[0082] Next, the sulfur battery performance tests for Example 1 and Example 2 were 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.

[0083] <Battery performance evaluation> From the charge-discharge curves shown in Figures 4 and 5, and the charge-discharge graphs shown in Figures 6 and 7, it was confirmed that the sulfur polymers of Example 1 and Example 2 have sufficient performance to function as positive electrode materials for lithium-sulfur secondary batteries.

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 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 １ , R ２ and R ３ among them, one or two 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), the rest are linear or branched alkyl groups having 1 to 15 carbon atoms (which may contain a halogen element), linear or branched alkenyl groups having 2 to 15 carbon atoms (which may contain a halogen element), linear or branched alkynyl groups having 2 to 15 carbon atoms (which may contain a halogen element), linear or branched alkoxy groups having 2 to 15 carbon atoms (which may contain a halogen element), 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. In addition, R １ , R ２ and R ３ may be the same or different.) A triazine 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 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 alkynyl 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 ４ , R ５ and R ６ 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. ４ , R ５ and R ６ They may be the same or different. An isocyanuric acid 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 triazine derivative represented by general formula (1) to the total of the triazine derivative represented by general formula (1) and the isocyanuric acid derivative represented by general formula (2) is 20.0 to 100.0% by mass. A method for producing sulfur polymers characterized by the following.

2. The triazine derivative represented by the general formula (1) is given by the following formula (1A): 【Transformation 3】 The isocyanuric acid derivative represented by the general formula (2) is 2,4,6-tris(allyloxy)-1,3,5-triazine, and the isocyanuric acid 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 a 1,3,5-trialyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione represented by .

3. The method for producing a sulfur polymer according to claim 1, characterized in that the dithiocarbamyl acid salt 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 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.

6. 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 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 １ , R ２ and R ３ 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. １ , R ２ and R ３ They may be the same or different. A triazine 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 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 alkynyl 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 ４ , R ５ and R ６ 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. ４ , R ５ and R ６ They may be the same or different. An isocyanuric acid 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 triazine derivative represented by general formula (1) to the total of the triazine derivative represented by general formula (1) and the isocyanuric acid derivative represented by general formula (2) is 20.0 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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