Method for producing sulfur-containing polymers

Abstract

To provide a production method that can produce a sulfur-containing polymer such as a polyarylene sulfide with small environmental load and high yield.SOLUTION: The present invention provides a method for producing a sulfur-containing polymer by polymerizing a monomer component containing a disulfide compound and / or a thiol compound. The polymerization is conducted using a solvent containing a cyclic sulfone.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a sulfur-containing polymer, and more particularly to a method for producing a sulfur-containing polymer by polymerizing a monomer component in a specific solvent. [Background technology]

[0002] Known high-refractive-index materials include polycarbonates with aromatic rings and polymeric materials with a fluorene skeleton. Refractive-index adjusting materials for improving the light extraction efficiency of LEDs and lens materials for imaging systems require materials with a high Abbe number, i.e., low optical dispersion. Materials with sulfur or halogen molecules incorporated therein and materials containing metal oxide nanoparticles have been developed as such high-refractive-index and low-optical-dispersion materials. Polyarylene sulfides, particularly polyphenylene sulfide, are sulfur-containing materials generally known for their excellent heat resistance, corrosion resistance, and electrical insulation properties. In recent years, their application to optical materials with high refractive indexes has been attracting attention. For example, Patent Document 1 describes a molding material with a polyarylene sulfide skeleton in which one hydrogen atom on the benzene ring is substituted with a methyl group, which has excellent moldability in solution and can be used to form optical components with a high refractive index exceeding 1.70.

[0003] Various methods for producing polyarylene sulfides such as polyphenylene sulfide are known. For example, Patent Document 1 describes a method of oxidative polymerization using a disulfide compound or the like as a raw material and a quinone-based oxidizing agent, and a method of oxidative polymerization using a vanadium compound as a catalyst. In addition, a solvent can be used in the oxidative polymerization, and preferred examples of the solvent include chlorine-containing hydrocarbons such as dichloromethane. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2017-52834 Summary of the Invention [Problem to be solved by the invention]

[0005] Whether it is the oxidative polymerization method using a quinone-based oxidizing agent as described in Patent Document 1 or the oxidative polymerization method using a vanadium compound as a catalyst, there is a problem of low polymer yield when no solvent is used. Furthermore, the use of chlorine-containing hydrocarbon solvents such as dichloromethane tends to be restricted due to environmental impact and toxicity considerations. Furthermore, when other solvents are used, there are problems such as the tendency for side reactions to proceed and the difficulty in progressing the polymerization reaction. Therefore, an object of the present invention is to provide a production method that can produce sulfur-containing polymers such as polyarylene sulfide with a low environmental impact and high yield. [Means for solving the problem]

[0006] The present inventors have conducted extensive research into methods for producing sulfur-containing polymers such as polyarylene sulfides, and have found that the use of a solvent containing a cyclic sulfone improves the activity and selectivity of the polymerization reaction of a monomer component containing a disulfide compound and / or a thiol compound, thereby enabling the production of a sulfur-containing polymer as a polymerization reaction product in high yield. Specifically, the present invention provides a method for producing a sulfur-containing polymer by polymerizing a monomer component containing a disulfide compound and / or a thiol compound, characterized in that the polymerization is carried out using a solvent containing a cyclic sulfone. [Effects of the Invention]

[0007] In the method for producing a sulfur-containing polymer according to the present invention, a solvent containing a cyclic sulfone is used, which reduces the environmental impact and enables the production of a sulfur-containing polymer in high yield from a monomer component containing a disulfide compound and / or a thiol compound. Therefore, high-quality sulfur-containing polymers can be provided at low cost. Therefore, materials using the sulfur-containing polymers obtained by the production method of the present invention are useful as optical materials, such as lenses. DETAILED DESCRIPTION OF THE INVENTION

[0008] The present invention will be described in detail below. A combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention. Furthermore, in this specification, "(meth)acrylate" means "acrylate" or "methacrylate," "(meth)acrylic" means "acrylic" or "methacrylic," and "(meth)acryloyl" means "acryloyl" or "methacryloyl." Furthermore, (meth)acrylate is sometimes referred to as a (meth)acrylic acid ester.

[0009] 1. Method for producing sulfur-containing polymers The production method of the present invention is a method for producing a sulfur-containing polymer by polymerizing a monomer component containing a disulfide compound and / or a thiol compound, characterized in that the polymerization is carried out using a solvent containing a cyclic sulfone. Therefore, the production method of the present invention can also be said to be a method for producing a sulfur-containing polymer, comprising a polymerization step of polymerizing a monomer component containing a disulfide compound and / or a thiol compound using a solvent containing a cyclic sulfone. The use of a solvent containing a cyclic sulfone improves the activity and selectivity of the polymerization reaction of the monomer component containing a disulfide compound and / or a thiol compound, thereby enabling the sulfur-containing polymer, which is the polymerization reaction product, to be obtained in high yield. The above polymerization will now be described.

[0010] <Polymerization> In the production method of the present invention, the polymerization of the monomer components is carried out using a solvent containing cyclic sulfone. Therefore, the polymerization is usually preferably carried out in a composition in which the monomer components are dispersed or dissolved in a solvent containing cyclic sulfone. The composition, i.e., a composition containing the monomer components and the solvent, is also referred to as a raw material composition, and the composition from the start of the polymerization reaction to the end of the polymerization reaction is also referred to as a reaction composition. The composition obtained by the polymerization reaction is also referred to as a polymer composition. The polymerization is preferably oxidative polymerization. A preferred embodiment of oxidative polymerization will be described later.

[0011] The monomer components used in the polymerization step are described below. The monomer components include disulfide compounds and / or thiol compounds. Among these, it is preferable to include a disulfide compound. As the disulfide compound, a diaryl disulfide compound represented by the following general formula (1) is more preferable, and as the thiol compound, a thioaryl compound represented by the following general formula (2) is more preferable. By using these compounds, it is usually possible to obtain a sulfur-containing polymer containing at least one structural unit selected from the group consisting of structural units (A), (B), and (C) described below.

[0012] [ka]

[0013] [ka]

[0014] (In formulas (1) and (2), A 1 and A 2 are the same or different and represent monovalent aromatic hydrocarbon groups which may have a substituent. A 1 and A 2Examples of the monovalent aromatic hydrocarbon group represented by the formula (I) include a phenyl group, a naphthyl group, an anthryl group, a triphenyl group, a biphenyl group, a phenanthryl group, etc. Among these, a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, or a triphenyl group is preferred, and a phenyl group is more preferred. A 1 and A 2 The substituent (also referred to as "substituent A") that the monovalent aromatic hydrocarbon group represented by the formula (I) may have is preferably a reactive functional group, a halogen atom, or an alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent, or a polar substituent, each of which may have a substituent (also referred to as "substituent B").

[0015] Examples of the reactive functional group include an acidic functional group, a basic functional group, a curable functional group, and groups containing these functional groups. Examples of the acidic functional group include a carboxyl group (-COOH), a phosphate group (-OPO(OH)), a hydroxyl group (-OH), a sulfo group (-SOH), a phosphonic acid group (-PO(OH)), a phosphinic acid group (-PO(OH)-), and a mercapto group (-SH). Examples of the basic functional group include an amino group, an ammonium group, an imino group, an amide group, an imide group, and a maleimide group. Examples of the curable functional group include a group having a reactive unsaturated bond, such as a group having a reactive double bond, such as a vinyl group, a (meth)acryloyl group, an allyl group, or a methallyl group; and a group having a reactive ionic bond, such as a group having a reactive cyclic ether group, such as an epoxy group or an oxetane group.

[0016] Examples of the groups containing these functional groups include groups having the above-mentioned acidic functional group, basic functional group, or curable functional group and a hydrocarbon chain or a bonding group (collectively referred to as a bonding chain). That is, in the present invention, the reactive functional group includes not only the above-mentioned acidic functional group, basic functional group, or curable functional group, but also groups containing these functional groups and a bonding chain. Examples of the bonding chain include divalent hydrocarbon groups such as alkylene groups and arylene groups, bonding groups such as ethers, esters, carbonyls, and amides, and combinations thereof. For example, when it is said that a carboxyl group is preferred as the reactive functional group, it means that the reactive functional group is preferably a carboxyl group and / or a group containing a carboxyl group.

[0017] The preferred form of the reactive functional group varies depending on the various physical properties of the sulfur-containing polymer obtained by the production method of the present invention. For example, from the viewpoint of improving the dispersibility of inorganic particles in the obtained sulfur-containing polymer, acidic functional groups, basic functional groups, or groups containing these functional groups are preferred, and carboxyl groups, phosphate groups, phosphonic acid groups, hydroxyl groups, or groups containing these functional groups are more preferred. From the viewpoint that the obtained sulfur-containing polymer is likely to have a low linear expansion coefficient, carboxyl groups, phosphate groups, phosphonic acid groups, hydroxyl groups, or groups containing these functional groups are preferred, and hydroxyl groups or groups containing hydroxyl groups are more preferred. From the viewpoint of improving the adhesion to the substrate in the obtained sulfur-containing polymer, carboxyl groups, phosphate groups, phosphonic acid groups, or groups containing these functional groups are preferred, and phosphate groups, phosphonic acid groups, or groups containing these functional groups are more preferred. In addition, examples of substrates that can improve adhesion include inorganic substrates such as inorganic particle substrates (coatings), metal oxide particle substrates (coatings), glass substrates, silicone substrates, and copper substrates, and organic substrates such as organic particle substrates (coatings), and polymer film substrates. From the viewpoint of improving heat resistance, mechanical strength, and solvent resistance, a carboxyl group, a hydroxyl group, an amino group, a maleimide group, a curable functional group, or a group containing these functional groups is preferred, and a carboxyl group, a hydroxyl group, an amino group, a maleimide group, a vinyl group, a (meth)acryloyl group, an allyl group, a methallyl group, an epoxy group, an oxetane group, or a group containing these functional groups is more preferred.

[0018] Among these, the reactive functional group is preferably a carboxyl group, a phosphate group, a phosphonic acid group, a hydroxyl group, a curable functional group, or a group containing these functional groups, from the viewpoint of being able to impart a higher refractive index along with excellent physical properties to the resulting sulfur-containing polymer, more preferably a carboxyl group, a phosphate group, a hydroxyl group, a vinyl group, an epoxy group, or a group containing these functional groups, and even more preferably a phosphate group, a hydroxyl group, a vinyl group, or a group containing these functional groups. Furthermore, from the viewpoint of being able to improve adhesion to the substrate with a low linear expansion coefficient in addition to a high refractive index, the reactive functional group is preferably a carboxyl group, a phosphate group, or a group containing these functional groups.

[0019] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and among these, a bromine atom is preferred. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, and a heptyl group. Among these, an alkyl group having 1 to 18 carbon atoms is preferred, an alkyl group having 1 to 6 carbon atoms is more preferred, and a methyl group is even more preferred.

[0020] Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an s-butoxy group, a t-butoxy group, a pentyloxy group, a phenoxy group, a cyclohexyloxy group, a benzyloxy group, etc. Among these, an alkoxy group having 1 to 18 carbon atoms is preferred, an alkoxy group having 1 to 6 carbon atoms is more preferred, and a methoxy group is more preferred.

[0021] Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a triphenyl group. Of these, a phenyl group is preferred. The aryl group preferably has 6 to 30 carbon atoms, more preferably 6 to 18, and even more preferably 6 to 12. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylpentyl group, a phenylhexyl group, and a phenyloctyl group. The aralkyl group preferably has 7 to 14 carbon atoms, and more preferably 7 to 9 carbon atoms. Examples of the sulfur-containing substituent include a thioalkyl group and a thioaryl group. Of these, a thioalkyl group is preferred. The sulfur-containing substituent preferably has 1 to 8 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 4 carbon atoms.

[0022] The alkyl group, alkoxy group, aryl group, aralkyl group, and sulfur-containing substituent may further have a substituent (substituent B). Examples of the substituent (substituent B) include an alkyl group and a halogen atom. Among these, an alkyl group is preferred from the viewpoint of the solubility of the resulting sulfur-containing polymer, and a halogen atom is preferred from the viewpoint of the dispersibility of inorganic particles.

[0023] In terms of further increasing the refractive index and Abbe number, the substituent (substituent A) that the monovalent aromatic hydrocarbon group may have is preferably the alkyl group having 1 to 18 carbon atoms or a sulfur-containing substituent, more preferably a methyl group or a thioalkyl group, and particularly preferably a methyl group. In terms of improving the dispersibility of inorganic particles, the substituent that the monovalent aromatic hydrocarbon group may have is more preferably a hydroxyl group or a sulfur-containing substituent, more preferably a hydroxyl group, a thioalkyl group or a thioaryl group, and particularly preferably a hydroxyl group.

[0024] The substituent (substituent A) that the monovalent aromatic hydrocarbon group may have is also preferably a functional group that has the property of being highly compatible with other resins, polymerizable monomers, solvents, etc. In the present invention, such a group is also referred to as a polar substituent.

[0025] Examples of the polar substituent include ester functional groups (e.g., methyl ester group: -COOCH3), carbonyl groups (e.g., acetyl group: -COCH3), thiocarbonyl groups (e.g., thioacetyl group: -CSCH3), nitro group (-NO2), sulfonyl groups (e.g., methanesulfonyl group: -SO2CH3), cyano group (-CN), alkoxy groups (e.g., methoxy group: -OCH3), sulfonate ester functional groups (e.g., methanesulfonic acid group: -OSO2CH3), phosphonate ester functional groups (e.g., -PO(OCH3)2), alkylthio groups (e.g., -SCH3), halogen atoms (e.g., Br, Cl), and halogen-containing hydrocarbon groups (e.g., CH2Cl, CF3).

[0026] The polar functional group includes not only polar functional groups but also groups containing polar functional groups. Examples of groups containing polar functional groups include groups having the polar functional group and a hydrocarbon chain or a bonding group (collectively referred to as a bonding chain). Examples of the bonding chain include divalent hydrocarbon groups such as alkylene groups and arylene groups, bonding groups such as ethers, esters, carbonyls, and amides, and combinations thereof. For example, when it is said that an acetyl group is preferred as the polar functional group, it means that the polar functional group is preferably an acetyl group and / or a group containing an acetyl group.

[0027] When the substituent A is a polar functional group, the resulting sulfur-containing polymer tends to have the property of easily dispersing inorganic substances. From the same viewpoint, an acidic functional group or a basic functional group is also preferred as the substituent A. From the above viewpoint, an ester group, a carbonyl group, an alkoxy group (particularly a methoxy group), an alkylthio group, a halogen atom, a halogen-containing hydrocarbon group, etc. are more preferred.

[0028] The number of substituents A that the monovalent aromatic hydrocarbon group may have is not particularly limited, but a smaller number is preferable in that the refractive index of the resulting sulfur-containing polymer will be even higher. Specifically, the number of substituents A per monovalent aromatic hydrocarbon group is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 to 2.

[0029] In the monovalent aromatic hydrocarbon group, there are no particular limitations on the position to which the substituent A is bonded. The same applies when the monovalent aromatic hydrocarbon group is a phenyl group, and when the substituent A is, for example, an alkyl group, there are no particular limitations on the bonding position, but it is preferably bonded to the 4-position of the phenyl group.

[0030] The diaryl disulfide compound is preferably a diphenyl sulfide compound represented by the following general formula (1-1): The thioaryl compound is preferably a compound represented by the following general formula (2-1):

[0031] [ka]

[0032] [ka]

[0033] (In formulas (1-1) and (2-1), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 are the same or different and represent a hydrogen atom or a substituent (A-1). Above R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 may be the same or different. 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10The substituent (A-1) represented by the formula (I) is preferably a reactive functional group, a halogen atom, or an alkyl group, alkoxy group, aryl group, aralkyl group, sulfur-containing substituent, or polar substituent, which may have a substituent (also referred to as "substituent (B-1)"). These substituents (A-1) are the same as the substituent (A) that the monovalent aromatic hydrocarbon group may have, including preferred embodiments. The substituent (B-1) is the same as the substituent (B) that the monovalent aromatic hydrocarbon group may have, including preferred embodiments. Among these, a methyl group or a thioalkyl group is more preferred as the substituent (A-1), and a methyl group is particularly preferred, in that the refractive index of the resulting sulfur-containing polymer can be further increased.

[0034] In the general formula (1-1), the R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 The number of the substituents (A-1) is an integer of 0 to 10, but is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2, in order to further increase the refractive index of the resulting sulfur-containing polymer. 1 , R 2 , R 3 , R 4 and R 5 The number of the substituents (A-1) is an integer of 0 to 5, but is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1, in order to further increase the refractive index of the resulting sulfur-containing polymer. 6 , R 7 , R 8 , R 9 and R 10 The same applies to the above general formula (2-1). 1 , R 2 , R 3 , R 4 and R 5The same is true for .

[0035] R in the above general formula (1-1) 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 and R 10 Among them, R 3 , R 8 is preferably a substituent (A-1). 1 , R 2 , R 3 , R 4 and R 5 Among them, R 3 is preferably the substituent (A-1).

[0036] Specific examples of the diphenyl sulfide compound include 3,3'-dimethyldiphenyl disulfide, 2,2'-dimethyldiphenyl disulfide, 2,2',3,3'-tetramethyldiphenyl disulfide, 2,2',5,5'-tetramethyldiphenyl disulfide, 2,2',6,6'-tetramethyldiphenyl disulfide, 3,3',5,5'-tetramethyldiphenyl disulfide, 2,2',3,3',5,5'-hexamethyldiphenyl disulfide, and 2,2',3,3',6,6'-hexamethyldiphenyl disulfide. 2,2',3,3',5,5',6,6'-Octamethyldiphenyl disulfide, 2,2'-Diethyldiphenyl disulfide, 3,3'-Diethyldiphenyl disulfide, 2,2',6,6'-Tetraethyldiphenyl disulfide, 2,2',3,3'-Tetraethyldiphenyl disulfide, 2,2',5,5'-Tetraethyldiphenyl disulfide, 3,3',5,5'-Tetraethyldiphenyl disulfide, 2,2',3,3',5,5'-Hexaethyldiphenyl disulfide, 2,2',3,3',6,6'-Hexaethyldiphenyl diphenyl disulfide, 2,2',3,3',5,5',6,6'-octaethyldiphenyl disulfide, 2,2'-dipropyldiphenyl disulfide, 3,3'-dipropyldiphenyl disulfide, 2,2',6,6'-tetrapropyldiphenyl disulfide, 2,2',3,3'-tetrapropyldiphenyl disulfide, 2,2',5,5'-tetrapropyldiphenyl disulfide, 3,3',5,5'-tetrapropyldiphenyl disulfide, 2,2',3,3',5,5'-hexapropyldiphenyl disulfide, 2,2',3,3 ',6,6'-Hexapropyldiphenyl disulfide, 2,2',3,3',5,5',6,6'-Octapropyldiphenyl disulfide, 2,2'-Diisopropyldiphenyl disulfide, 3,3'-Diisopropyldiphenyl disulfide, 2,2',6,6'-Tetraisopropyldiphenyl disulfide, 2,2',3,3'-Tetraisopropyldiphenyl disulfide, 2,2',5,5'-Tetraisopropyldiphenyl disulfide, 3,3',5,5'-Tetraisopropyldiphenyl disulfide, 2,2',3,3',5,Examples include 5'-hexaisopropyldiphenyl disulfide, 2,2',3,3',6,6'-hexaisopropyldiphenyl disulfide, and 2,2',3,3',5,5',6,6'-octaisopropyldiphenyl disulfide.

[0037] Specific examples of the thiol compound include 3-methylbenzenethiol, 2-methylbenzenethiol, thiophenol (benzenethiol), 2,3-dimethylbenzenethiol, 2,5-dimethylbenzenethiol, 2,6-dimethylbenzenethiol, and 3,5-dimethylbenzenethiol.

[0038] The disulfide compound can also be prepared by oxidation of a thiol compound. Therefore, in the polymerization step, a thiol compound can also be used as a precursor of the disulfide compound. A disulfide compound can be obtained by oxidatively bonding two molecules of a thiol compound. The method for oxidatively bonding is not particularly limited, and known methods can be used.

[0039] The polymerization in the production method of the present invention is carried out using a solvent containing a cyclic sulfone. The cyclic sulfone is not particularly limited, but is preferably, for example, a compound represented by the following general formula (3).

[0040] [ka]

[0041] (wherein n is an integer of 2 to 8, R a , R b represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms. In the general formula (3), a divalent hydrocarbon chain having 2 to 8 carbon atoms is bonded to a sulfur atom via carbon atoms at both ends of the hydrocarbon chain to form a cyclic structure, and each carbon atom is bonded to R a and R b are bonded.

[0042] Above R a , R b may be the same or different. That is, R bonded to any one of n carbon atoms a , R b may be the same or different. In addition, among n carbon atoms, R bonded to a certain carbon atom may be a , R b is an R bonded to another carbon atom. a , R b may be the same as or different from.

[0043] Above R a , R b At least one of R bonded to n carbon atoms is preferably a hydrogen atom, and all of R bonded to n carbon atoms are preferably hydrogen atoms. a , R b Of the total number (2n), it is preferable that n or more are hydrogen atoms, and more preferable that 2n are hydrogen atoms. a , R b Of the total number (2n), preferably two or more are hydrogen atoms, more preferably three or more are hydrogen atoms, even more preferably four or more are hydrogen atoms, and particularly preferably 2n (all) are hydrogen atoms.

[0044] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a chlorine atom being preferred. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, an t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 2,2-dimethylbutyl group, and a 2,3-dimethylbutyl group. Among these, an alkyl group having 1 to 3 carbon atoms is preferred, an alkyl group having 1 or 2 carbon atoms is more preferred, and a methyl group is even more preferred. The n is an integer from 2 to 8. An integer from 2 to 6 is preferred, an integer from 3 to 5 is more preferred, and an integer from 4 is particularly preferred.

[0045] Among the above cyclic sulfones, for example, ethylene sulfone, trimethylene sulfone, sulfolane (tetramethylene sulfone), 3-methyl sulfolane, pentamethylene sulfone, hexamethylene sulfone, etc. are preferred, and from the viewpoint of excellent industrial availability, sulfolane (tetramethylene sulfone) and 3-methyl sulfolane are preferred.

[0046] The solvent includes cyclic sulfone, but may further include solvents other than cyclic sulfone. Preferred solvents used together with cyclic sulfone include, for example, dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, tetrachloroethylene, 1,1,2,2-tetrachloroethane, nitromethane, nitrobenzene, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, N-methylpyrrolidone, tetrahydrofuran, ethyl acetate, and cyclopentyl methyl ether.

[0047] The amount of the solvent used is not particularly limited, but is preferably 1 to 10,000 parts by mass per 100 parts by mass of the monomer component. From the viewpoint of reactivity, it is more preferably 10 parts by mass or more, and even more preferably 50 parts by mass or more. On the other hand, from the viewpoint of economy, the upper limit is more preferably 1,000 parts by mass or less, and even more preferably 500 parts by mass or less.

[0048] The content of the cyclic sulfone in the solvent is preferably 1 to 100% by mass relative to 100% by mass of the solvent (total amount), more preferably 10% by mass or more, even more preferably 50% by mass or more, more preferably 80% by mass or more, and particularly preferably 100% by mass.

[0049] The oxidative polymerization is not particularly limited, but is preferably oxidative polymerization using a quinone compound or oxidative polymerization using a catalyst. From the viewpoint of reducing the amount of waste liquid, oxidative polymerization using a catalyst is more preferred.

[0050] Oxidative polymerization using a catalyst will now be described. In the polymerization step, when the monomer component is polymerized using a solvent containing a cyclic sulfone, the polymerization is preferably carried out in the presence of a catalyst. For example, it is more preferable to carry out the polymerization reaction by heating a composition in which the monomer component and the catalyst are dissolved or dispersed in the solvent. In oxidative polymerization using a catalyst, the preferred amount of solvent used (amount of solvent relative to the monomer component), the content of cyclic sulfone contained in the solvent, and preferred solvents other than cyclic sulfone contained in the solvent are also as described above.

[0051] The catalyst is preferably a catalyst (oxidative polymerization catalyst) having oxidative polymerization activity for a monomer component containing a disulfide compound and / or a thiol compound. The catalyst is not particularly limited, but is preferably a substance containing a metal element such as vanadium (V), zirconium (Zr), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), or iron (Fe). The form of the substance containing a metal element is not particularly limited, but examples include metals, metal compounds, and other forms containing the metal element.

[0052] Examples of the metal include metals (elemental metals) consisting solely of the metal and alloys containing the metal as a main component. The metal compounds are not particularly limited as long as they are compounds containing a metal, and examples include inorganic compounds, organic acid salts, complexes (coordination compounds), and the like. Examples of the inorganic compounds include halides, sulfates, nitrates, phosphates, silicates, carbonates, hydroxides, oxides, sulfides, tellurides, and intermetallic compounds. Among these, halides are preferred. Examples of the halides include fluorides, chlorides, bromides, and iodides, with chlorides being more preferred. Examples of the organic acid salts are not particularly limited as long as they are organic acid salts containing a metal element, and examples include carboxylates and sulfonates. Examples of the carboxylates include acetates and oxalates. Examples of the sulfonates include paratoluenesulfonates and trifluoromethanesulfonates. The complex is not particularly limited as long as it is a complex containing a metal element, and examples thereof include ammine complexes, cyano complexes, halogeno complexes, hydroxy complexes, phthalocyanine complexes, porphyrin complexes, carbonyl complexes, salen complexes, ethylenediamine complexes, β-diketone complexes, β-diketoester complexes, etc. Examples of other forms of the substance containing a metal element include forms in which metal ions such as monovalent or trivalent ions of a metal are contained as cations in a cation exchanger such as zeolite or mica.

[0053] The substances containing the metal elements may be used alone or in combination of two or more. The catalyst is not particularly limited in its form in the raw material composition. For example, it may be dispersed in the raw material composition in a particulate form or the like, or may be present in a state dissolved in the monomer component or solvent. Similarly, the substance containing the metal element is not particularly limited in its form in the raw material composition. For example, it may be dispersed in the raw material composition in a particulate form or the like, or may be present in a state dissolved in the monomer component or solvent. The solvent is as described above. The same applies to the form of the catalyst present in the reaction composition and the form of the substance containing the metal element present.

[0054] Among the substances containing the above metal elements, substances containing vanadium or iron as a metal element (these are also referred to as vanadium-containing substances and iron-containing substances, respectively) are preferred because of their high catalytic activity for oxidative polymerization.

[0055] The iron-containing substance preferably contains iron as the metal element as the main component. Specifically, the iron content relative to the total content of metal elements contained in the iron-containing substance (100 mol%) is preferably 50 mol% or more, more preferably 80 mol% or more, even more preferably 95 mol% or more, even more preferably 98 mol% or more, and particularly preferably 100 mol%. The vanadium-containing substance also preferably contains vanadium as the metal element as the main component, and the preferred content of vanadium relative to the total amount of metal elements is the same as the iron content in the iron-containing substance. The specific and preferred forms of the vanadium-containing substance and iron-containing substance are as described above.

[0056] The vanadium-containing substance is preferably a metal containing vanadium or an oxovanadium compound having a V=O bond in the vanadium compound molecule, such as vanadyl acetylacetonate, oxovanadium salen complex, N,N'-bissalicylideneethylenediamine oxovanadium, phthalocyanine oxovanadium, or tetraphenylporphyrin oxovanadium. The iron-containing substance is preferably an iron compound having chlorine in the molecule. Compounds containing iron with an oxidation number of 3 or greater are also preferred. Particularly preferred examples of such iron-containing substances include ferric chloride (Fe(Cl)3), 5,10,15,20-tetraphenyl-21H,23H-porphine iron(III) chloride, and iron(III) trifluoromethanesulfonate.

[0057] The amount of the catalyst used in the polymerization is not particularly limited, but the total content of metal elements contained in the catalyst relative to 100 mol % of the monomer components is preferably in the range of 0.001 to 50 mol %, and from the viewpoint that catalyst residue can be removed by a simple purification process, it is preferably 30 mol % or less, more preferably 20 mol % or less, more preferably 10 mol % or less, and even more preferably 5 mol % or less.From the viewpoint that a sulfur-containing polymer with a high molecular weight is easily obtained, it is more preferably 0.01 mol % or more, even more preferably 0.1 mol % or more, and particularly preferably 1 mol % or more.

[0058] The polymerization is preferably carried out in the presence of oxygen. By carrying out the polymerization in the presence of oxygen, the oxidative polymerization reaction is promoted. In a specific embodiment, a method of supplying an oxygen-containing gas during the polymerization reaction is preferred. That is, the polymerization is preferably carried out under the supply of an oxygen-containing gas. For example, a method of supplying an oxygen-containing gas to the gas phase during the polymerization reaction, a method of bubbling an oxygen-containing gas into the reaction composition during the polymerization reaction, or the like is employed.

[0059] It is believed that by carrying out the above polymerization reaction in the presence of oxygen gas, it is possible to promote the hydrogen elimination reaction from the carbon constituting the aromatic ring contained in the monomer component. Furthermore, in the polymerization step, the oxidation number of the metal contained in the catalyst can usually change. However, by carrying out the polymerization reaction in the presence of oxygen gas, the valence of the metal contained in the catalyst can be maintained at a high oxidation number, which is thought to promote oxidative polymerization. From this viewpoint, a method of continuously supplying an oxygen-containing gas to the reaction composition during the polymerization reaction is preferred, and among these, a bubbling method is preferred.

[0060] The oxygen-containing gas is preferably a gas containing oxygen molecules (O2). The oxygen-containing gas may contain gas components other than oxygen molecules (O2). The gas components other than oxygen molecules (O2) contained in the oxygen-containing gas are not particularly limited, but preferred examples include rare gases such as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn); and inert gases such as nitrogen (N2). In addition to the above inert gases, carbon dioxide gas (CO2), water vapor, etc. may also be contained.

[0061] The content of oxygen molecules (O2) in the oxygen-containing gas is not particularly limited, but at room temperature (25°C) and under 1 atmosphere, the volume ratio of oxygen molecules (O2) in the oxygen-containing gas is preferably 0.1 to 100% by volume relative to 100% by volume of the oxygen-containing gas. More preferably, it is 1% by volume or more, and even more preferably, it is 10% by volume or more. The upper limit is more preferably 60% by volume or less, and even more preferably, it is 30% by volume or less.

[0062] The total content of oxygen molecules (O2) and inert gas in the oxygen-containing gas is not particularly limited, but at room temperature (25°C) and 1 atmosphere, the total volume ratio of oxygen molecules (O2) and inert gas in the oxygen-containing gas is preferably 80 to 100% by volume relative to 100% by volume of the oxygen-containing gas, more preferably 95% by volume or more, and even more preferably 98% by volume or more.

[0063] The oxygen-containing gas is not particularly limited, but examples thereof include oxygen gas, a mixed gas of oxygen and nitrogen, and air. From the viewpoint of economical efficiency, air is preferably used. The water vapor concentration in the oxygen-containing gas is not particularly limited, but is preferably 1000 g / m 3 Less than 10 g / m 3 Less than 1g / m is more preferable. 3 More preferably, 0.1 g / m or less 3 The following is most preferred, with dry air being preferred:

[0064] The amount of oxygen-containing gas to be supplied is not particularly limited, but is preferably 1 m3 of the total volume of the reaction composition.3 The supply rate per minute is 0.0001m 3 / min~10m 3 From the viewpoint of increasing the reaction rate, it is more preferable that the reaction rate is 0.0005 m / min. 3 / min or more, and more preferably 0.001 m 3 The upper limit is more preferably 1 m / min from the viewpoint of easy control of the reaction temperature. 3 / min or less, and more preferably 0.1 m 3 / min or less.

[0065] The amount of oxygen-containing gas fed is also determined based on the total volume of the reaction composition per m 3 The oxygen (O2) supply rate per minute is 0.00002 m 3 / min~2m 3 From the viewpoint of increasing the reaction rate, it is more preferable that the reaction rate is 0.0001 m / min. 3 / min or more, and more preferably 0.0002 m 3 The upper limit is more preferably 0.2 m / min from the viewpoint of easy control of the reaction temperature. 3 / min or less, and more preferably 0.02 m 3 / min or less.

[0066] In the polymerization step, it is preferable to further use an acid and / or a salt thereof. By using the acid and / or a salt thereof in combination with the catalyst, it becomes easier to control the molecular weight of the polymer obtained by the polymerization reaction to a high range, and it becomes easier to obtain a high-molecular-weight sulfur-containing polymer even in a short time.

[0067] The acid is preferably a Bronsted acid, for example, inorganic acids such as phosphoric acid, phosphonic acid, nitric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, persulfuric acid, and sulfurous acid; sulfonic acids such as methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, 10-camphorsulfonic acid, trifluoromethanesulfonic acid, and 1,1,2,2-tetrafluoroethanesulfonic acid; and carboxylic acids such as acetic acid, trifluoroacetic acid, perfluoropropionic acid, perfluorobutyric acid, and benzoic acid.

[0068] The acid preferably has an acid dissociation constant of -19 to 4. More preferably, the acid dissociation constant is 3 or less and -8 or more. Examples of acids having an acid dissociation constant of -19 to 4 include inorganic acids such as phosphoric acid, nitric acid, sulfuric acid, persulfuric acid, sulfurous acid, hydrochloric acid, and hydrobromic acid; sulfonic acids such as methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, 10-camphorsulfonic acid, trifluoromethanesulfonic acid, and 1,1,2,2-tetrafluoroethanesulfonic acid; chlorocarboxylic acids such as chloroacetic acid, dichloroacetic acid, and trichloroacetic acid; and fluorocarboxylic acids such as fluoroacetic acid, difluoroacetic acid, trifluoroacetic acid, perfluoropropionic acid, perfluorobutyric acid, and 4-fluorobenzoic acid. Of these, 10-camphorsulfonic acid, trifluoromethanesulfonic acid, and persulfuric acid are preferred.

[0069] The salt of the acid is not particularly limited as long as it is a salt of the acid, but for example, salts of the acid with a metal element of Group 1 of the periodic table such as sodium or potassium, a metal element of Group 2 of the periodic table such as magnesium or calcium, or ammonium are preferred. Among these, for example, sodium persulfate, ammonium persulfate, sodium toluenesulfonate, sodium trifluoromethanesulfonate, etc. are preferred. The salt of the acid preferably has a pH of 1 to 6.9, more preferably 2 to 6, at 25°C when dissolved in pure water.

[0070] The above acids and / or salts thereof may be used singly or in combination of two or more. The amount of the above acids and / or salts thereof used is preferably 0.01 to 100 mol%, more preferably 0.1 to 10 mol%, and even more preferably 0.5 to 5 mol%, relative to 100 mol% of the monomer component. The amount of the acid and / or salt thereof used is preferably 0.1 to 1000 mol%, more preferably 1 to 100 mol%, and even more preferably 5 to 50 mol%, relative to 100 mol% of the total amount of metal elements contained in the metal element-containing substance.

[0071] From the viewpoint of improving the reaction efficiency, the pH of the entire reaction system (raw material composition containing the acid and / or its salt) to which the acid and / or its salt has been added is preferably 0.1 to 7, more preferably 1 to 6, and most preferably 2 to 5. The pH is the value measured when the reaction system (raw material composition containing the acid and / or its salt) is directly measured, and is measured using pH indicator paper and a pH meter.

[0072] It is also preferable to further use an oxidizing agent in the polymerization step. The oxidizing agent is not particularly limited, but examples thereof include quinone-based compounds. The oxidizing agent may be used alone or in combination of two or more. Among these, quinone-based compounds are preferred.

[0073] The quinone compound is not particularly limited, but examples thereof include 2,3-dichloro-5,6-dicyano-parabenzoquinone (DDQ), 2,3,5,6-tetrachloroparabenzoquinone, 2,3,5,6-tetrabromobenzoquinone, 2,3,5,6-tetrafluoroparabenzoquinone, anthraquinone, 1,4-naphthoquinone, 2,3-dichloro-1,4-naphthoquinone, 2,3-dibromo-1,4-naphthoquinone, 2,3-dicyano-1,4-naphthoquinone, 3,4,5,6-tetrachloroorthobenzoquinone, 3,4,5,6-tetrabromoorthobenzoquinone, and 3,4,5,6-tetrafluorobenzoquinone. Of these, DDQ is preferred due to its high oxidizing power and easy availability. The quinone compounds may be used alone or in combination of two or more.

[0074] The amount of the oxidizing agent used is preferably 0.01 to 50 mol %, more preferably 0.1 to 20 mol %, and even more preferably 0.5 to 10 mol %, relative to 100 mol % of the monomer component.

[0075] The polymerization may be carried out at atmospheric pressure at a temperature below the boiling point of the solvent, under reflux conditions, or under pressure while heating to a temperature above the boiling point. The polymerization temperature is not particularly limited as long as it is a temperature at which oxidative polymerization proceeds. However, in terms of ease of carrying out the oxidative polymerization reaction using inexpensive equipment, it is preferably 0 to 250°C, more preferably 30°C or higher, and even more preferably 50°C or higher. The upper limit is preferably 200°C or lower, and even more preferably 180°C or lower. The polymerization time is not particularly limited, but is typically 0.1 to 100 hours, preferably 1 to 80 hours, more preferably 5 to 50 hours, and even more preferably 10 to 24 hours.

[0076] In the polymerization, the monomer components may be added successively during the polymerization reaction. In the polymerization, the polymerization may be performed in multiple stages, such as by oxidatively polymerizing the thiol compound to obtain a disulfide compound and then oxidatively polymerizing the obtained disulfide compound. A composition (raw material composition) containing the monomer components, the solvent, and the catalyst is maintained preferably at the polymerization temperature for the polymerization time, whereby a polymerization reaction of the monomer components occurs, and a composition (polymer composition) containing a sulfur-containing polymer is produced.

[0077] Oxidative polymerization using a quinone compound will now be described. In the oxidative polymerization, the monomer components are polymerized in the presence of a quinone compound. In the polymerization step, when the monomer components are polymerized using a solvent containing a cyclic sulfone, the polymerization is preferably carried out in the presence of a quinone compound. For example, it is more preferable to carry out the polymerization reaction by heating a composition in which the monomer components and the quinone compound are dissolved or dispersed in the solvent, as necessary. In the oxidative polymerization using a quinone compound, the preferred amount of solvent used (amount of solvent relative to the monomer components), the content of cyclic sulfone contained in the solvent, and preferred solvents other than cyclic sulfone contained in the solvent are also as described above.

[0078] The quinone compound is not particularly limited, but examples thereof include 2,3-dichloro-5,6-dicyano-parabenzoquinone (DDQ), 2,3,5,6-tetrachloroparabenzoquinone, 2,3,5,6-tetrabromobenzoquinone, 2,3,5,6-tetrafluoroparabenzoquinone, anthraquinone, 1,4-naphthoquinone, 2,3-dichloro-1,4-naphthoquinone, 2,3-dibromo-1,4-naphthoquinone, 2,3-dicyano-1,4-naphthoquinone, 3,4,5,6-tetrachloroorthobenzoquinone, 3,4,5,6-tetrabromoorthobenzoquinone, and 3,4,5,6-tetrafluorobenzoquinone. Of these, DDQ is preferred due to its high oxidizing power and easy availability. The quinone compounds may be used alone or in combination of two or more.

[0079] Furthermore, when using the quinone compound, it is also preferable to use an acid. The combined use of an acid with the quinone compound allows the oxidizing power of the quinone compound to be maintained. The acid is not particularly limited, and examples thereof include sulfuric acid, acetic acid, methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfonic acid, 1,1,2,2-tetrafluoroethanesulfonic acid, trifluoroacetic acid, perfluoropropionic acid, and perfluorobutyric acid. Of these, 1,1,2,2-tetrafluoroethanesulfonic acid is preferred in terms of increasing acidity. The above acids may be used alone or in combination of two or more.

[0080] When the quinone compound and the acid are used in combination, the amount of acid added is preferably 10 to 1000 moles, more preferably 50 to 500 moles, and even more preferably 80 to 120 moles, per 100 moles of the total amount of the quinone compound added. The amount of the quinone compound added is preferably 0.1 to 3 mol, more preferably 0.8 to 1.5 mol, and even more preferably 0.9 to 1.1 mol, per mol of the monomer component used.

[0081] The polymerization may be carried out at a temperature below the boiling point of the solvent under normal pressure, under reflux conditions, or under pressure while heating to a temperature above the boiling point. The polymerization temperature is not particularly limited as long as it is a temperature at which oxidative polymerization proceeds. However, in terms of ease of carrying out the oxidative polymerization reaction using inexpensive equipment, it is preferably 0 to 200°C, more preferably 10°C or higher, and even more preferably 15°C or higher. The upper limit is preferably 180°C or lower, and even more preferably 150°C or lower. The polymerization time is not particularly limited, but is typically 0.1 to 100 hours, preferably 1 to 80 hours, more preferably 5 to 50 hours, and even more preferably 10 to 24 hours.

[0082] As preferred embodiments of the production method of the present invention, oxidative polymerization using a catalyst and oxidative polymerization using a quinone-based compound have been described above. Regardless of the oxidative polymerization method, the polymerization step can produce a sulfur-containing polymer whose main chain has a repeating structure in which hydrocarbon chains contained in a disulfide compound and / or a thiol compound are linked via sulfide groups (-S-) or the like. When a diaryl disulfide compound represented by the general formula (1) and / or a thioaryl compound represented by the general formula (2) is used as the monomer component, a sulfur-containing polymer containing at least one structural unit selected from the group consisting of structural units (A), (B), and (C) described below can usually be obtained. Under the preferred conditions described above, a sulfur-containing polymer containing a relatively high content of structural unit (A) can be obtained. In the production method of the present invention, the polymerization step is not limited to oxidative polymerization using a catalyst or oxidative polymerization using a quinone-based compound. The effects of the present invention can be achieved as long as a solvent containing cyclic sulfone is used in the polymerization using the above-mentioned monomer component.

[0083] <Processes other than the polymerization process> The production method of the present invention may further include a purification step and / or an oxidation step in addition to the polymerization step. The polymer composition containing the sulfur-containing polymer obtained in the polymerization step contains at least the solvent used in the polymerization step, as well as catalyst residues and substances derived from quinone compounds, i.e., so-called impurities. These impurities may affect the optical properties and heat resistance of the sulfur-containing polymer. Therefore, it is preferable to isolate the sulfur-containing polymer from the obtained polymer composition and reduce these impurities from the perspective of improving the quality of the sulfur-containing polymer. Therefore, a preferred embodiment of the production method of the present invention further includes a purification step.

[0084] The oxidation step is a step of oxidizing the polymer obtained in the polymerization step. By oxidizing the polymer, sulfur atoms in sulfide groups (-S-) in the main chain of the sulfur-containing polymer are oxidized to form "-SO-" or "-SO2-", resulting in a sulfur-containing polymer with a high content of the structural units (B) and (C) described below. As described below, by having the structural units (B) and (C) or by increasing their content, the refractive index, solubility, and the like can be controlled. Therefore, in one preferred embodiment of the production method of the present invention, the production method further includes an oxidation step. The oxidation step may be performed after the polymerization step and before the purification step, or may be performed after the purification step, but is preferably performed before the purification step.

[0085] The purification step will be described. As the purification method, a conventionally known purification method can be used. For example, it is preferable to use a reprecipitation method. The reprecipitation method is not particularly limited, but examples include a method in which the polymer composition is dropped into hydrochloric acid-acidified methanol to precipitate the polymer, which is then filtered to obtain a precipitate, and the obtained precipitate is washed with water or a lower alcohol such as methanol. By performing the purification method after the oxidation step, components derived from the oxidizing agent used in the oxidation step can also be removed, which is preferable.

[0086] The purification step can also be performed using a conventionally known adsorbent such as activated carbon to remove components derived from the oxidizing agent used in the oxidation step and impurities derived from the polymerization step. It is also preferable to use the reprecipitation method in combination with a method using an adsorbent. The timing of the purification step is not particularly limited, and the step can be performed before or after the oxidation step. That is, the polymer obtained after the purification step can be subjected to the oxidation step, or the purification step can be performed on a composition containing the polymer obtained in the oxidation step. In particular, when the production method of the present invention includes the oxidation step, it is preferable to perform the purification step on a composition containing the polymer obtained after both the polymerization step and the oxidation step, since this allows for the production of a sulfur-containing polymer with fewer impurities derived from the raw materials used in each step.

[0087] The oxidation step is described below. The oxidation step is a step of oxidizing the polymer obtained in the polymerization step. The oxidation of the polymer produced in the polymerization step can be carried out by an oxidation reaction using an oxidizing agent.

[0088] The oxidizing agent is not particularly limited and can be any known oxidizing agent, such as quinone compounds, perbenzoic acid, metachloroperbenzoic acid, lead tetraacetate, thallium acetate, tetracyanoquinodimethane, tetracyanoethylene, cerium(IV) acetylacetonate, manganese(III) acetylacetonate, peroxides, chloric acid, hypochlorous acid, hypochlorites, and compounds capable of generating hypochlorous acid. Among these, it is preferable to use at least one compound selected from the group consisting of peroxides, chloric acid, hypochlorous acid, hypochlorites, and compounds capable of generating hypochlorous acid, since they can appropriately oxidize sulfur atoms (sulfide groups, -S-) contained in the main chain to form sulfoxides (sulfinyl groups) (-SO-). Examples of peroxides include metachloroperbenzoic acid, hydrogen peroxide, ammonium persulfate, sodium persulfate, peracetic acid, and t-butyl hydroperoxide.

[0089] Among these, the oxidizing agent is preferably a peroxide, and more preferably metachloroperbenzoic acid or hydrogen peroxide. From the viewpoint of preventing oxidation to sulfonyl (—SO2—) by an excess of oxidizing agent, the oxidizing agent is even more preferably metachloroperbenzoic acid. Furthermore, when hydrogen peroxide is used as the oxidizing agent, it is preferable to use a phase transfer catalyst such as trifluoroacetone while reducing the amount of water, in order to prevent precipitation of the sulfur-containing polymer. The oxidizing agent may be used alone or in combination with two or more. It is also preferable to use at least one compound selected from the group consisting of hypochlorous acid, hypochlorites, and compounds capable of generating hypochlorous acid as the oxidizing agent.

[0090] The amount of the oxidizing agent to be added is not particularly limited as long as the oxidation reaction of sulfur atoms proceeds to obtain the target polymer, but is usually preferably 1 to 1,000 mol, more preferably 10 to 500 mol, and even more preferably 100 to 400 mol, per mol of sulfur atoms in the sulfur-containing polymer.

[0091] The reaction temperature of the oxidation reaction is not particularly limited as long as it is a temperature at which the desired oxidation reaction proceeds, but is preferably 0 to 200°C, more preferably 10°C or higher, and even more preferably 15°C or higher, in order to facilitate the oxidation reaction, and is more preferably 180°C or lower, and even more preferably 150°C or lower, in order to suppress side reactions. The reaction time of the oxidation reaction is not particularly limited, but is usually 0.1 to 100 hours, preferably 1 to 80 hours, more preferably 5 to 50 hours, and even more preferably 10 to 24 hours.

[0092] When oxidation is to be carried out to -SO2-, the reaction may be carried out for a longer time than the above-mentioned reaction time. In this case, the amount of the oxidizing agent added is not particularly limited as long as the oxidation reaction of the desired sulfur atoms proceeds, but is usually preferably 1.5 to 100 mol, more preferably 2 to 50 mol, and even more preferably 2 to 10 mol, per mol of sulfur atoms in the polymer.

[0093] In the oxidation reaction, a solvent may be used, and preferred examples of the solvent used include the same solvents as those used in the polymerization step. The sulfur-containing polymer obtained by the oxidation step may contain residual acids, etc., and therefore it is preferable to carry out the purification step.

[0094] The method for producing the sulfur-containing polymer may include other steps in addition to the polymerization step, purification step, and oxidation step. Examples of the other steps include an aging step, a neutralization step, a dilution step, a drying step, a concentration step, a solvent substitution step, and a dissolution step. These steps can be carried out by known methods.

[0095] The above-described production method of the present invention enables the production of a sulfur-containing polymer in high yield. Therefore, the sulfur-containing polymer obtained by the production method of the present invention can be used alone or as a sulfur-containing polymer composition in combination with other components such as inorganic particles for various applications, including optical materials, particularly optical applications requiring a high refractive index.

[0096] 2. Preferred Examples of Sulfur-Containing Polymers Obtained by the Production Method of the Present Invention Preferred examples of the sulfur-containing polymer obtained by the production method of the present invention will be described below. In the production method of the present invention, by using a monomer component containing a diaryl disulfide compound represented by the above general formula (1) and / or a thioaryl compound represented by the above general formula (2), which are shown as preferred monomer components, it is possible to obtain a preferred sulfur-containing polymer, for example, a sulfur-containing polymer having at least one structural unit selected from the group consisting of a structural unit (A) represented by the following general formula (4), a structural unit (B) represented by the following general formula (5), and a structural unit (C) represented by the following general formula (6).

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] (In formulas (4) to (6), X 1 , X 2 and X 3 are the same or different and represent divalent aromatic hydrocarbon groups which may have a substituent. That is, in the production method of the present invention, a method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of structural unit (A) represented by general formula (4), structural unit (B) represented by general formula (5), and structural unit (C) represented by general formula (6) by using a monomer component containing a diaryl disulfide compound represented by general formula (1) and / or a thioaryl compound represented by general formula (2) as a monomer component is one preferred embodiment of the production method of the present invention. Furthermore, a sulfur-containing polymer having at least one structural unit selected from the group consisting of structural unit (A) represented by general formula (4), structural unit (B) represented by general formula (5), and structural unit (C) represented by general formula (6) is a preferred embodiment of the sulfur-containing polymer obtained by the production method of the present invention. A preferred sulfur-containing polymer obtained by the above-described preferred embodiment of the production method of the present invention will now be described. First, each structural unit contained in the sulfur-containing polymer will be described.

[0101] <Constituent unit (A)> In the structural unit (A) represented by the general formula (4), 1represents a divalent aromatic hydrocarbon group which may have a substituent. Examples of the divalent aromatic hydrocarbon group include a phenylene group, a naphthylene group, an anthrylene group, a triphenylene group, a biphenylene group, and a phenanthrylene group. Among these, the divalent aromatic hydrocarbon group is preferably a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, or a triphenylene group, and more preferably a phenylene group, in terms of reducing the light dispersion of the polymer.

[0102] X 1 The substituents that the divalent aromatic hydrocarbon group represented by the formula (1) may have and the number of the substituents are as follows: 1 The same applies to the substituent (A) that the monovalent aromatic hydrocarbon group represented by the following formula may have, including preferred embodiments.

[0103] In the divalent aromatic hydrocarbon group, the position to which the substituent is bonded is not particularly limited. The same applies when the divalent aromatic hydrocarbon group is a phenylene group, and when the substituent is, for example, an alkyl group, the bonding position is not particularly limited, but it is preferably bonded to the 4-position of the phenylene group. It is preferable that a plurality of the structural units (A) are contained in the sulfur-containing polymer, and it is more preferable that they are contained as repeating units. The structural unit (A) is preferably a structural unit (A-1) represented by the following general formula (4-1), in that the refractive index becomes higher.

[0104] [ka]

[0105] (In the formula, R 11 are the same or different and represent a reactive functional group, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, a sulfur-containing substituent, or a polar substituent, each of which may have a substituent. 11 represents the number of digits, and is an integer between 0 and 4.) R 11When there are a plurality of, they may be the same or different.

[0106] R 11 The reactive functional group, halogen atom, or optionally substituted alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent, or polar substituent, represented by the formula (1), is the same as the substituent that the divalent aromatic hydrocarbon group in the general formula (4) may have, including preferred embodiments. Among these, the above R 11 As the alkyl group, a methyl group and a thioalkyl group are more preferred, and a methyl group is particularly preferred.

[0107] In the general formula (4-1), the bonding position of the other main chain relative to the carbon atom (position 1) to which the sulfide group is bonded is not particularly limited, and may be position 2, 3, or 4. Of these, position 2 or 3 is preferred, and position 3 is more preferred. Furthermore, when the sulfur-containing polymer contains the structural unit (A-1), it may contain multiple structural units (A-1) bonded at different bonding positions.

[0108] In the general formula (4-1), a represents a substituent R 11 and is an integer of 0 to 4. In order to further increase the refractive index, a is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. In the above general formula (4-1), the above substituent R 11 The position of the structural unit (A-1) is not particularly limited, and may be the 2-position, 3-position, or 4-position of the phenylene group. Of these, the 4-position or 2-position is preferred, and the 4-position is more preferred. The sulfur-containing polymer preferably contains a plurality of structural units (A-1), and more preferably contains the structural unit (A-1) as a repeating unit.

[0109] <Constituent Unit (B)> In the structural unit (B) represented by the general formula (5), 2 represents a divalent aromatic hydrocarbon group which may have a substituent. 2The divalent aromatic hydrocarbon group represented by the formula (I) includes the above-mentioned X 1 Preferred examples of the divalent aromatic hydrocarbon group include the same groups as those represented by X 2 The substituent that the divalent aromatic hydrocarbon group represented by the formula (I) may have is, for example, the above-mentioned X 1 Preferred examples of the substituents include the same groups as those that may be contained in the divalent aromatic hydrocarbon group represented by the formula: X 2 The divalent aromatic hydrocarbon group represented by X and its substituents are 1 It may be the same as or different from the divalent aromatic hydrocarbon group represented by the following formula (1) or its substituent. It is preferable that a plurality of the structural units (B) are contained in the sulfur-containing polymer, and it is more preferable that they are contained as repeating units. The structural unit (B) is preferably a structural unit (B-1) represented by the following general formula (5-1), in that it has high polarity due to solubility and the like.

[0110] [ka]

[0111] (In the formula, R 12 are the same or different and represent a reactive functional group, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, a sulfur-containing substituent, or a polar substituent, each of which may have a substituent. 12 represents the number of digits, and is an integer between 0 and 4.) R 12 When there are a plurality of, they may be the same or different.

[0112] R 12 The reactive functional group, halogen atom, or optionally substituted alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent, or polar substituent, represented by the formula (I), may be any of the above-mentioned R 11 Examples of such groups include the same groups as those represented by R 12 A preferred embodiment in R 11 In particular, the refractive index can be further increased by using the above-mentioned R12 As the alkyl group, a methyl group and a thioalkyl group are more preferred, and a methyl group is particularly preferred.

[0113] In the general formula (5-1), the bonding position of the other main chain relative to the carbon atom (position 1) to which the sulfinyl group is bonded is not particularly limited, and may be position 2, 3, or 4. Of these, position 2 or 3 is preferred, and position 3 is more preferred. Furthermore, when the sulfur-containing polymer contains the structural unit (B-1), it may contain multiple structural units (B-1) bonded at different bonding positions.

[0114] In the general formula (5-1), b is a substituent R 12 and is an integer of 0 to 4. In order to further increase the refractive index, b is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1. In the above general formula (5-1), the substituent R 12 The bonding position of R 11 This is the same as in the case of The sulfur-containing polymer preferably contains a plurality of the structural units (B-1), and more preferably contains the structural units (B-1) as repeating units.

[0115] <Constituent Unit (C)> In the structural unit (C) represented by the general formula (6), 3 represents a divalent aromatic hydrocarbon group which may have a substituent. 3 The divalent aromatic hydrocarbon group represented by the formula (I) includes the above-mentioned X 1 Preferred examples of the divalent aromatic hydrocarbon group include the same groups as those represented by X 3 The substituent that the divalent aromatic hydrocarbon group represented by the formula (I) may have is, for example, the above-mentioned X 1 Preferred examples of the substituents include the same groups as those that may be contained in the divalent aromatic hydrocarbon group represented by the formula: X 3 The divalent aromatic hydrocarbon group represented by X and its substituents are 1 or X 2 and the substituents thereof may be the same as or different from the divalent aromatic hydrocarbon group represented by the following formula: The sulfur-containing polymer preferably contains a plurality of the structural units (C), and more preferably contains the structural units (C) as repeating units. The structural unit (C) is preferably a structural unit (C-1) represented by the following general formula (6-1), in view of high transparency.

[0116] [ka]

[0117] (In the formula, R 13 are the same or different and represent a reactive functional group, a halogen atom, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, a sulfur-containing substituent, or a polar substituent, each of which may have a substituent. 13 represents the number of digits, and is an integer between 0 and 4.) R 13 When there are a plurality of, they may be the same or different.

[0118] R 13 The reactive functional group, halogen atom, or optionally substituted alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent, or polar substituent, represented by the formula (I), may be any of the above-mentioned R 11 Examples of such groups include the same groups as those represented by R 13 A preferred embodiment in R 11 In particular, the refractive index can be further increased by using the above-mentioned R 13 As the alkyl group, a methyl group and a thioalkyl group are more preferred, and a methyl group is particularly preferred.

[0119] In the general formula (6-1), the bonding position of the other main chain relative to the carbon atom (position 1) to which the sulfonyl group is bonded is not particularly limited, and may be position 2, 3, or 4. Of these, position 2 or 3 is preferred, and position 3 is more preferred. Furthermore, when the sulfur-containing polymer contains the structural unit (C-1), it may contain multiple structural units (C-1) bonded at different positions.

[0120] In the general formula (6-1), c represents a substituent R 13 and is an integer of 0 to 4. c is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1, in order to further increase the refractive index. 13 The bonding position of R 11 This is the same as in the case of The sulfur-containing polymer preferably contains a plurality of the structural units (C-1), and more preferably contains the structural unit (C-1) as a repeating unit.

[0121] The polymerization using a monomer component containing a diaryl disulfide compound represented by general formula (1) and / or a thioaryl compound represented by general formula (2) produces a sulfur-containing polymer having at least one structural unit selected from the group consisting of structural units (A), (B), and (C). The polymer typically tends to contain a higher proportion of structural unit (A) than the other structural units. For example, the proportion of structural unit (A) in the sulfur-containing polymer obtained by the polymerization step is preferably 50 to 100 mol%, more preferably 80 to 100 mol%, and even more preferably 95 to 100 mol%, based on 100 mol% of all structural units in the polymer. Furthermore, the combined proportion of structural units (B) and (C) in the polymer is preferably 0 to 50 mol%, more preferably 0 to 20 mol%, and even more preferably 0 to 5 mol%, based on 100 mol% of all structural units in the polymer.

[0122] The content ratio of the structural units (A), (B), and (C) in the sulfur-containing polymer can be adjusted by selecting the conditions for the polymerization reaction, and can also be adjusted by further carrying out the oxidation step.

[0123] The sulfur-containing polymer may be an alternating copolymer, a block copolymer, or a random copolymer of the structural units (A), (B), and (C). The sulfur-containing polymer may have one or more of the structural units (A), (B), or (C).

[0124] The sulfur-containing polymer may include only one of the structural units (A), (B), and (C), or may include two or three structural units. These structural units and their content ratios can be appropriately selected depending on the purpose and application of the sulfur-containing polymer. For example, the sulfur-containing polymer preferably includes the structural unit (A), more preferably as the main component, in order to achieve a higher refractive index. The sulfur-containing polymer preferably includes the structural unit (B), more preferably as the main component, in order to achieve both solubility and a high refractive index. The sulfur-containing polymer preferably includes the structural unit (C), more preferably as the main component, in order to achieve both transparency and a high refractive index.

[0125] From the above viewpoints, in the sulfur-containing polymer, the content of the structural unit (A) is preferably 1 to 100 mol%, more preferably 10 to 100 mol%, and even more preferably 50 to 100 mol%, relative to 100 mol% of all structural units in the polymer, from the viewpoint of a high refractive index. In this case, the total content of the structural units (B) and (C) is preferably 0 to 99 mol%, more preferably 0 to 90 mol%, and even more preferably 0 to 50 mol%, relative to 100 mol% of all structural units.

[0126] In the sulfur-containing polymer, the content of the structural unit (B) is preferably 1 to 100 mol%, more preferably 10 to 100 mol%, and even more preferably 50 to 100 mol%, relative to 100 mol% of all structural units in the polymer, from the viewpoint of high polarity resulting from solubility. In this case, the total content of the structural units (A) and (C) is preferably 0 to 99 mol%, more preferably 0 to 90 mol%, and even more preferably 0 to 50 mol%, relative to 100 mol% of all structural units.

[0127] From the viewpoint of high transparency, the content of the structural unit (C) in the sulfur-containing polymer is preferably 1 to 100 mol%, more preferably 10 to 100 mol%, and even more preferably 50 to 100 mol%, relative to 100 mol% of all structural units in the polymer. In this case, the total content of the structural units (A) and (B) is preferably 0 to 99 mol%, more preferably 0 to 90 mol%, and even more preferably 0 to 50 mol%, relative to 100 mol% of all structural units.

[0128] In the sulfur-containing polymer, the total content of the structural units (A), (B), and (C) is preferably 50 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and particularly preferably 100 mol%, based on 100 mol% of all structural units in the polymer.

[0129] The sulfur-containing polymer may have a structural unit (D) other than the structural unit (A), the structural unit (B), and the structural unit (C). Examples of the structural unit (D) include structural units having at least the reactive functional group described above.

[0130] Examples of monomers that can introduce the structural unit (D) include monomers having a polymerizable double bond and the reactive functional group. Examples of the polymerizable double bond include vinyl, (meth)acryloyl, allyl, and methallyl groups, with (meth)acryloyl being preferred. Examples of monomers having a polymerizable double bond and the reactive functional group include carboxyl group-containing (meth)acrylates such as 2-carboxyethyl (meth)acrylate, 2-carboxypropyl (meth)acrylate, 3-carboxypropyl (meth)acrylate, and 4-carboxybutyl (meth)acrylate; phosphate group-containing (meth)acrylates such as 2-(meth)acryloyloxyethyl acid phosphate; epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate; and vinyl ether group-containing (meth)acrylates such as 2-(2-vinyloxyethoxy)ethyl (meth)acrylate.

[0131] The content of the structural unit (D) is preferably 0 to 80 mol%, more preferably 0 to 50 mol%, even more preferably 0 to 20 mol%, even more preferably 0 to 10 mol%, and particularly preferably 0 to 5 mol%, relative to 100 mol% of all structural units of the polymer.

[0132] The sulfur-containing polymer may have a chain structure, a cyclic structure, or a mixture thereof. Among these, the sulfur-containing polymer preferably has a chain structure as a main component, from the viewpoint of excellent solubility and mechanical strength. Specifically, the sulfur-containing polymer preferably has a chain structure content of 50% by mass or more, more preferably 80% by mass or more, even more preferably 95% by mass or more, and particularly preferably 98% by mass or more, based on 100% by mass of the sulfur-containing polymer.

[0133] The sulfur-containing polymer preferably has excellent visible light transmittance. For example, the parallel ray transmittance (Tb) at a wavelength of 400 nm measured for a sample prepared by the following method is preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more. The transmittance can be measured using a commercially available spectrophotometer, for example, a spectrophotometer (V-700 series ultraviolet-visible-infrared spectrophotometer manufactured by JASCO Corporation). (Sample preparation) A laminate consisting of a colorless, transparent glass substrate and a 1-μm-thick thin film of a sulfoxide-containing polymer formed on one side thereof is used as the measurement sample. The measurement sample can be prepared, for example, by applying a solution of a sulfur-containing polymer dissolved in a solvent to a colorless, transparent glass substrate and one side thereof, followed by drying. A preferred example involves preparing a solution of a sulfur-containing polymer dissolved in hexafluoro-2-propanol to a concentration of 5% by mass, spin-coating the resulting solution onto one side of a glass substrate (S1111, manufactured by Matsunami Glass Industry Co., Ltd.) with excellent visible light transmittance at approximately 500 rpm for 60 seconds, and then drying at 100°C for 10 minutes to form a thin film (1 μm thick).

[0134] The sulfur-containing polymer preferably also has excellent transmittance after heating. For example, the transmittance Ta (%) of a sample prepared by the above method after heating in air at 260°C for 10 minutes is preferably 70% or more, more preferably 80% or more, and even more preferably 85% or more. The transmittance (Ta) can be measured in the same manner as the transmittance (Tb). The sulfur-containing polymer preferably has an absolute difference between the transmittance (Ta) and the transmittance (Tb) of 10% or less, more preferably 5% or less, even more preferably 3% or less, and particularly preferably 1% or less.

[0135] The sulfur-containing polymer preferably has a metal content of 10,000 ppm or less relative to the sulfur-containing polymer (solid content). The metal content is more preferably 1,000 ppm or less relative to the polymer, even more preferably 500 ppm or less, and even more preferably 100 ppm or less. Furthermore, from the viewpoint that molded articles using the sulfur-containing polymer tend to have excellent toughness, the metal content is more preferably 0.01 ppm or more relative to the sulfur-containing polymer (solid content), even more preferably 0.1 ppm or more. The metal content can be determined by the above-mentioned ICP atomic emission spectroscopy.

[0136] The sulfur-containing polymer preferably has an elemental ratio (O / S) of the oxygen atom O bonded to the sulfur atom S in the main chain to the sulfur atom S in the main chain of 0.1 to 1.5. When the elemental ratio is within the above range, the transparency and refractive index become higher. The sulfur atom S in the main chain specifically means, for example, the sulfur atom S of -SO- in the main chain in the structural unit (B). In the structural unit (A), it means the sulfur atom S of -S- in the main chain, and in the structural unit (C), it means the sulfur atom S of -SO2- in the main chain. The oxygen atom bonded to the sulfur atom S in the main chain specifically means, for example, the oxygen atom O of -SO- in the main chain in the structural unit (B), and in the structural unit (C), it means the oxygen atom O of -SO2- in the main chain.

[0137] The element content ratio (O / S) is preferably 0.3 or more, and more preferably 0.5 or more, in order to further increase transparency, and is preferably 1.3 or less, and even more preferably 1.1 or less, in order to further increase the refractive index. The element content ratio can be determined by evaluating and measuring the peak intensities of the oxygen 1s orbital (O1s), carbon 1s orbital (C1s), and sulfur 2p orbital (S2p) using an X-ray photoelectron spectrometer (XPS).

[0138] The weight-average molecular weight (Mw) of the sulfur-containing polymer is preferably 500 to 10,000,000. When the weight-average molecular weight is within the above range, the polymer can be suitably used as an optical material. From the viewpoint of improving mechanical properties, the weight-average molecular weight is more preferably 1,000 or more, more preferably 1,100 or more, and even more preferably 1,500 or more. It is more preferably 3,000 or more, and even more preferably 10,000 or more, and from the viewpoint of reducing melt viscosity, it is more preferably 1,000,000 or less, and even more preferably 100,000 or less.

[0139] The polydispersity (weight average molecular weight / number average molecular weight) of the sulfur-containing polymer is preferably 1 or more and 10 or less. When the polydispersity is within the above range, molding becomes easy. In terms of further improving moldability, the polydispersity is more preferably 5 or less, and even more preferably 3 or less. The weight average molecular weight and number average molecular weight can be determined by measurement using gel permeation chromatography (GPC), specifically, by the method described in the examples below. The polydispersity can be determined by dividing the weight average molecular weight by the number average molecular weight.

[0140] The sulfur-containing polymer preferably has a glass transition temperature (Tg) of 80 to 250°C. When the glass transition temperature is in the above range, molding can be easily carried out. From the viewpoint of increasing heat resistance, the glass transition temperature is more preferably 90°C or higher, and even more preferably 100°C or higher, and from the viewpoint of facilitating molding, it is more preferably 200°C or lower. The glass transition temperature can be determined by a method in which a differential scanning calorimeter (DSC) is used to measure the temperature from room temperature to 250°C (at a temperature increase rate of 10°C / min) in a nitrogen gas atmosphere, and the DSC curve is obtained by evaluating the intersection of the baseline and the tangent at the inflection point.

[0141] The sulfur-containing polymer preferably has a refractive index of 1.69 or more. When the refractive index is within the above range, the polymer can be suitably used in a wide variety of applications, such as optical materials (members), machine part materials, electric and electronic part materials, automobile part materials, civil engineering and construction materials, molding materials, as well as paints and adhesive materials. The refractive index is more preferably 1.7 or more, and even more preferably 1.71 or more. The refractive index can be determined by forming a film having a thickness of 50 nm using the polymer as a measurement sample and measuring the film using a spectroscopic ellipsometer UVISEL (manufactured by HORIBA Scientific) with NaD rays (589 nm).

[0142] The sulfur-containing polymer preferably has an Abbe number of 10 or more. When the Abbe number is within the above range, light dispersion is small, making it possible to provide an optical material suitable for lenses. The Abbe number is more preferably 15 or more, even more preferably 18 or more, and even more preferably 20 or more. From the viewpoint of adjusting light dispersion, the Abbe number is preferably 60 or less, and more preferably 55 or less.

[0143] The Abbe number can be calculated by forming a film using the polymer in the same manner as in measuring the refractive index, measuring the refractive index at D line (589.3 nm), F line (486.1 nm), and C line (656.3 nm) using the spectroscopic ellipsometer, and then using the following calculation formula. Abbe number (vD) = (nD-1) / (nF-nC). In the formula, nD, nF, and nC represent the refractive indices at the Fraunhofer D line (589.3 nm), F line (486.1 nm), and C line (658.3 nm), respectively.

[0144] 3.Applications The sulfur-containing polymer obtained by the production method of the present invention and the sulfur-containing polymer composition containing the polymer are suitably used for optical materials, optical device members, display device members, etc. Specific examples of such applications include optical applications such as eyeglass lenses, imaging lenses for cameras such as (digital) cameras, mobile phone cameras, and in-vehicle cameras, light beam focusing lenses, light diffusing lenses, and other lenses; LED encapsulants, optical adhesives, optical pressure-sensitive adhesives, optical transmission bonding materials, filters, diffraction gratings, diffractive optical elements, prisms, light guides, watch glasses, and transparent glass and cover glass for display devices; optical device applications such as photosensors (optical sensors (CMOS sensors, TOF sensors, etc.)), photoswitches, LEDs, micro LEDs, light-emitting elements, optical waveguides, multiplexers, demultiplexers, disconnectors, optical splitters, and optical fiber adhesives; and display device applications such as substrates for display elements such as LCDs, organic electroluminescent (EL) displays, and PDPs, color filter substrates, touch panel substrates, index matching materials used in touch panels, etc., display protective films, display backlights, light guide plates, anti-reflection films, anti-fogging films, and light extraction enhancers for LEDs, organic electroluminescent (EL) displays, etc. Among these, imaging lenses, filters, diffraction gratings, diffractive optical elements, prisms, light guides, LEDs, micro LEDs, light-emitting elements, color filters, and touch panels are more preferred. Furthermore, the sulfur-containing polymer obtained by the production method of the present invention is likely to generally have a wide range of no absorption in the visible and infrared regions. Such polymers are also suitable for use as optical materials in the visible and infrared regions.

[0145] The sulfur-containing polymer obtained by the production method of the present invention, as well as a sulfur-containing polymer composition containing the polymer, are used in a variety of applications, including not only optical applications but also mechanical component materials, electrical and electronic component materials, automotive component materials, civil engineering and construction materials, molding materials, as well as paints and adhesives. For example, the sulfur-containing polymer obtained by the production method of the present invention generally tends to have excellent heat resistance, and such polymers with excellent heat resistance can also be used as heat-resistant materials, ferroelectric materials, heat-dissipating materials, separators for battery materials, filters such as gas separation membranes and liquid separation membranes, electrode materials for fuel cells and Li batteries, and other battery components, such as electrolyte materials. They can also be suitably used as insulating materials, antenna materials, and the like, taking advantage of their low dielectric properties.

[0146] The sulfur-containing polymer obtained by the production method of the present invention, as well as the sulfur-containing polymer composition containing the polymer, can be suitably used as a molding material. Examples of molding methods include conventionally known injection molding, T-die molding, inflation molding, imprint molding, nanoimprint molding, and other molding using a mold or resin mold. The desired shape may be formed by a casting method, coating method, or other method. The shape is not particularly limited, and examples thereof include various known shapes such as lenses, sheets, and films.

[0147] Furthermore, the sulfur-containing polymer obtained by the production method of the present invention and the sulfur-containing polymer composition containing the polymer can be suitably used in etching processes such as conventional plasma etching and resist processes utilizing conventional solubility differences. They can also be suitably used for coating by spin coating, bar coating, squeegee coating, inkjet coating, etc. The composition containing the sulfur-containing polymer obtained by the production method of the present invention is preferably a thermoplastic resin composition in terms of improved processability, and is preferably a curable resin composition in terms of reduced viscosity and improved conformability to fine molds and resin dies during molding. As described above, the sulfur-containing polymer obtained by the production method of the present invention and the sulfur-containing polymer composition containing the polymer can be suitably used in a wide range of applications including optical applications. [Example]

[0148] Examples are given below to explain the present invention in more detail, but the present invention is not limited to only these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass". The evaluation of each polymer obtained in the examples and comparative examples, and the sulfide-containing polymer used in the examples, etc. was carried out according to the following methods.

[0149] <Weight average molecular weight (Mw)> The weight average molecular weight of the polymer was determined by measuring under the following conditions by gel permeation chromatography (GPC) method. Apparatus 1: SHIMAZU, CBM-20A. Apparatus 2: Agilent Technologies 1260 Infinity. Detector: Differential refractive index detector (RI) (SHIMAZU, SPD-20MA), and ultraviolet-visible-infrared spectrophotometer (SHIMAZU, SPD-20MA). Column: TOSOH, TSKgel SuperHM-N. Column temperature: 40 °C Flow rate: 0.3 ml / min. Calibration curve: Polystyrene Standards. Eluent: Chloroform, tetrahydrofuran.

[0150] <MALDI (Matrix-Assisted Laser Desorption / Ionization Time-of-Flight Mass Spectrometry)> For the obtained polymer, MALDI measurement was carried out under the following conditions. [[ID=3,5]] Apparatus: Matrix-Assisted Laser Desorption / Ionization Time-of-Flight Mass Spectrometer (Bruker AutoflexIII) Sample preparation: Dissolve about 2 mg of the measurement sample in 1.0 g of tetrahydrofuran, 20 mg of 2,5-dihydroxybenzoic acid as a matrix agent, and 2.0 mg of sodium iodide as an ionizing agent. After applying the adjusted solution to the measurement target plate, dry it at room temperature for about 100 minutes.

[0151] < 1 ​ The obtained polymer was subjected to the following conditions: 1 H-NMR measurements were carried out. Apparatus: Nuclear magnetic resonance spectrometer (400 MHz) manufactured by JEOL Ltd. Measurement solvent: deuterated dichloromethane, deuterated chloroform. Sample preparation: Several mg to several tens of mg of the obtained polymer was dissolved in a measurement solvent.

[0152] <ir> The obtained polymer was subjected to IR measurement under the following conditions. Apparatus: JASCO Fourier transform infrared spectrophotometer (FT / IR-6100). Sample preparation: Approximately 2 mg of sample was diluted with approximately 300 mg of dry potassium bromide (KBr). The mixture was ground with a mortar and pestle and molded.

[0153] <Binding energy> A sample was prepared by spin-coating 0.25 ml of the polymer solution onto a silicon wafer to form a film. Using this sample, the binding energy was measured from the peak position of the 2p3 / 2 orbital of the sulfur atom using a JEOL photoelectron spectrometer (JPS-9010TR, XPS device).

[0154] <Organic elemental analysis> The obtained polymer was subjected to elemental analysis using the following apparatus to determine the contents of C, H, S, and O. Equipment: J Science Lab JM10.

[0155] (Monomer synthesis) [Synthesis Example 1] Methanol (1.1 L) was added to a 2.0 L three-neck flask, followed by the slow addition of 98% sulfuric acid (4.7 mL) and stirring. After stirring, 2,2'-dithiodibenzoic acid (101.10 g, 0.33 mol) was added and the mixture was heated to reflux for 48 hours. After the reaction was completed, the reaction solution was cooled to room temperature, and the precipitated reaction solid was filtered, washed with methanol and then purified water, and vacuum dried at room temperature for 4 hours to recover dimethyl 2,2'-dithiodibenzoate. The yield was 99%. 1 H-NMR, 13 The structure of the product was confirmed by C-NMR, XPS, and FAB-MS analyses.

[0156] (Synthesis of sulfur-containing polymers) [Example 1] A 50 mL test tube was charged with diphenyl disulfide (10.92 g, 50.00 mmol), dimethyl 2,2'-dithiodibenzoate (3.34 g, 10.00 mmol) obtained in Synthesis Example 1, iron(III) chloride (486.57 mg, 3.00 mmol), (+)-CSA ((+)-10-camphorsulfonic acid) (140.77 mg, 0.600 mmol), sodium peroxodisulfate (NaSO) (128.57 mg, 0.600 mmol), and 12 mL of sulfolane as a solvent. The test tube was then heated to 160 °C under nitrogen flow (20 mL / min) for 10 minutes, after which air bubbling was switched to (20 mL / min) and the mixture was stirred for 40 hours to allow oxidative polymerization. After stirring, the mixture was cooled to room temperature, and THF (100 mL) was added as a solvent and stirred for 10 minutes. The resulting reaction solution was then added dropwise to 1.0 L of a 3% hydrochloric acid acidic methanol solution to reprecipitate the polymer. After reprecipitation, the precipitate was filtered using a Kiriyama filter and washed with methanol and pure water. The resulting powder was then vacuum dried at room temperature to obtain a brown polymer (Po1) powder. The yield was 85%. The structure of the resulting polymer (Po1) was as follows: 1 The identification was carried out by various analyses such as H-NMR, GPC, IR, and elemental analysis. 1 H-NMR (CD2Cl2, 400 MHz, ppm): δ = 8.13 (m, 1H), δ = 7.23 (m, 27H), δ = 3.95 (m, 3H). IR revealed a peak at around 1730 cm-1 derived from ester groups. Elemental analysis confirmed the composition (polyarylene sulfide) as follows: H = 4.2%, C = 66.0%, S = 24.6%, O = 5.2%.

[0157] [Example 2] A 1.0 L three-neck flask was charged with diphenyl disulfide (218.33 g, 1.00 mol), dimethyl 2,2'-dithiodibenzoate (66.88 g, 0.20 mol) obtained in Synthesis Example 1, iron(III) chloride (9.73 g, 60.00 mmol), (+)-CSA ((+)-10-camphorsulfonic acid) (2.79 g, 12.00 mmol), sodium peroxodisulfate (NaSO) (2.86 g, 12.00 mmol), and 240 mL of sulfolane as a solvent. The three-neck flask was then heated to 160 °C with nitrogen flow (20 mL / min) for 10 minutes, then switched to air bubbling (150 mL / min) and stirred for 48 hours to carry out oxidative polymerization. After polymerization, the mixture was cooled to room temperature, and THF (100 mL) was added as a solvent and stirred for 10 minutes. Next, the obtained reaction solution was added dropwise to 1.0 L of a 3% hydrochloric acid acidic methanol solution to reprecipitate the polymer. After reprecipitation, the precipitate was filtered using a Kiriyama filter and washed with methanol and pure water. The obtained powder was then vacuum dried at room temperature to obtain a brown polymer (Po2) powder. The yield was 86% (calculated assuming that 100% of the additive remained). The structure of the obtained polymer (Po2) was as follows: 1 The identification was carried out by various analyses such as H-NMR, GPC, IR, and elemental analysis. 1 H-NMR (CD2Cl2, 400 MHz, ppm): δ = 8.13 (m, 1H), δ = 7.23 (m, 25H), δ = 3.95 (m, 3H). IR revealed a peak at around 1730 cm-1 derived from ester groups. Elemental analysis confirmed the composition (polyarylene sulfide) as follows: H = 4.3%, C = 63.8%, S = 26.0%, O = 5.9%.

[0158] [Comparative Example 1] Diphenyl disulfide (10.92 g, 50.00 mmol), dimethyl 2,2'-dithiodibenzoate (3.34 g, 10.00 mmol) obtained in Synthesis Example 1, iron(III) chloride (486.57 mg, 3.00 mmol), (+)-CSA ((+)-10-camphorsulfonic acid) (140.77 mg, 0.600 mmol), and sodium peroxodisulfate (NaSO) (128.57 mg, 0.600 mmol) were added to a 50 mL test tube. The test tube was then heated to 160 °C under nitrogen flow (20 mL / min) for 10 minutes, after which air bubbling was switched to (150 mL / min) and the mixture was stirred for 180 hours to carry out oxidative polymerization. After stirring, the mixture was cooled to room temperature, and THF (100 mL) was added as a solvent and stirred for 10 minutes. Next, the obtained reaction solution was added dropwise to 1.0 L of a 3% hydrochloric acid acidic methanol solution to reprecipitate the polymer. After reprecipitation, the precipitate was filtered using a Kiriyama filter and washed with methanol and pure water. The obtained powder was then vacuum dried at room temperature to obtain a brown polymer (Po3) powder. The yield was 62%. The structure of the obtained polymer (PoC1) was as follows: 1 The identification was carried out by various analyses such as H-NMR, GPC, IR, and elemental analysis. 1 H-NMR (CD2Cl2, 400 MHz, ppm): δ = 8.13 (m, 1H), δ = 7.23 (m, 29H), δ = 3.95 (m, 3H). IR revealed a peak at around 1730 cm-1 attributable to ester groups. Elemental analysis confirmed the composition (polyarylene sulfide) as follows: H = 4.3%, C = 64.9%, S = 25.2%, O = 5.0%.

[0159] In Examples 1 and 2, compared to Comparative Example 1, the sulfur-containing polymer had a higher molecular weight, the time required for the reaction was shorter, and it was obtained in a higher yield.

[0160] [Table 1] < / ir>

Claims

[Claim 1] A method for producing a sulfur-containing polymer by polymerizing a monomer component containing a disulfide compound and / or a thiol compound, comprising: The method for producing a sulfur-containing polymer, wherein the polymerization is oxidative polymerization using a catalyst, and the polymerization is carried out in a solvent containing a cyclic sulfone.

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