JP2023030738A - Method for producing sulfur-containing polymer - Google Patents

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

The present invention relates to a method for producing sulfur-containing polymers. More specifically, it relates to a method for producing a sulfur-containing polymer, in which monomer components are polymerized in a specific solvent.

Polycarbonate having an aromatic ring and polymeric materials having a fluorene skeleton are known as high refractive index materials. Materials with a large Abbe's number, that is, with small light dispersion are required as refractive index adjusting materials for improving the light extraction efficiency of LEDs and lens materials for imaging systems. As materials with such a high refractive index and low light dispersion, materials into which sulfur molecules or halogen molecules are introduced, materials containing metal oxide nanoparticles, and the like have been developed. As a material containing sulfur, polyarylene sulfide, especially polyphenylene sulfide, is generally known as a material that is excellent in heat resistance, corrosion resistance, electrical insulation, etc. However, in recent years, it has been used as an optical material with a high refractive index. Attention is focused on applications. For example, in Patent Document 1, one hydrogen atom of a benzene ring is substituted with a methyl group as a molding material capable of forming an optical member having excellent moldability in a solution state and having a high refractive index exceeding 1.70. Also described are molding compositions having a polyarylene sulfide skeleton.

Various methods for producing polyarylene sulfide 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. A solvent can be used in the oxidative polymerization, and a preferred solvent is exemplified by a chlorine-containing hydrocarbon such as dichloromethane.

JP 2017-52834 A

Even in the method of oxidative polymerization using a quinone-based oxidizing agent described in Patent Document 1 and the method of oxidative polymerization using a vanadium compound as a catalyst, it is said that the polymer yield is low when no solvent is used. I had a problem. In addition, the use of chlorine-containing hydrocarbon solvents such as dichloromethane tends to be restricted from the viewpoint of environmental load and toxicity. Moreover, when other solvents are used, there are problems such as side reactions tending to proceed and polymerization reactions to proceed with difficulty. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a production method capable of producing a sulfur-containing polymer such as polyarylene sulfide with a small environmental burden and at a high yield.

The present inventors conducted various studies on a method for producing a sulfur-containing polymer such as polyarylene sulfide, and found that the use of a solvent containing a cyclic sulfone facilitates the polymerization reaction of a monomer component containing a disulfide compound and/or a thiol compound. It has been found that the activity and selectivity are improved, and as a result, the sulfur-containing polymer, which is the polymerization reaction product, can be obtained in high yield. That is, 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. It is a method for producing a sulfur-containing polymer.

In the method for producing a sulfur-containing polymer according to the present invention, by using a solvent containing a cyclic sulfone, the environmental load is small, and moreover, the sulfur-containing polymer is higher than the monomer component containing the disulfide compound and/or the thiol compound. yield can be obtained. Therefore, it is possible to provide a high-quality sulfur-containing polymer at a low cost. Therefore, the material using the sulfur-containing polymer obtained by the production method of the present invention is useful as an optical material such as a lens.

The present invention will be described in detail below. A combination of two or more of the individual preferred embodiments of the invention described below is also a preferred embodiment of the invention. In the present specification, "(meth)acrylate" means "acrylate" or "methacrylate", "(meth)acryl" means "acryl" or "methacryl", and "(meth)acryloyl ” means “acryloyl” or “methacryloyl”. Moreover, (meth)acrylate may be called (meth)acrylic acid ester.

1. Method for Producing a Sulfur-Containing Polymer 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, the polymerization comprising a cyclic sulfone. A method for producing a sulfur-containing polymer characterized by using a solvent. Therefore, the production method of the present invention is a sulfur-containing polymer production method including a polymerization step of polymerizing a monomer component containing a disulfide compound and/or a thiol compound using a solvent containing a cyclic sulfone. can. By using a solvent containing a cyclic sulfone, the activity and selectivity of the polymerization reaction of the monomer component containing the disulfide compound and/or the thiol compound are improved, so that the yield of the sulfur-containing polymer, which is the polymerization reaction product, is high. can be obtained with
The above polymerization will be explained.

<Polymerization>
In the production method of the present invention, the polymerization of the monomer component is carried out using a solvent containing a cyclic sulfone. Therefore, the above polymerization is usually preferably carried out in a composition in which the monomer component is dispersed or dissolved in a solvent containing a cyclic sulfone. The above composition, that is, a composition containing a monomer component and a solvent is also referred to as a raw material composition, and a composition from the start of the polymerization reaction to the end of the polymerization reaction is also referred to as the reaction composition. A composition obtained by a polymerization reaction is also called a polymer composition. The polymerization is preferably oxidative polymerization. Preferred embodiments of oxidative polymerization are described below.

The monomer components used in the polymerization step will be described. The monomer component includes a disulfide compound and/or a thiol compound. Among these, it is preferable to contain a disulfide compound. The disulfide compound is more preferably a diaryl disulfide compound represented by the following general formula (1), and the thiol compound is more preferably a thioaryl compound represented by the following general formula (2). By using these compounds, a sulfur-containing polymer containing at least one structural unit selected from the group consisting of structural units (A), (B), and (C), which will be described later, can be obtained. .

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

Examples of the reactive functional groups include acidic functional groups, basic functional groups, curable functional groups, and groups containing these functional groups. Examples of the acidic functional groups include carboxyl group (--COOH), phosphoric acid group (--OPO(OH) ₂ ), hydroxyl group (--OH), sulfo group (--SO ₃ H), phosphonic acid group (--PO(OH) ₂ ), a phosphinic acid group (--PO(OH)--), a mercapto group (--SH), and the like. Examples of the basic functional group include basic functional groups such as an amino group, an ammonium group, an imino group, an amide group, an imide group and a maleimide group. Examples of the curable functional groups include groups having reactive unsaturated bonds such as groups having reactive double bonds such as vinyl groups, (meth)acryloyl groups, allyl groups, and methallyl groups; A group having a reactive ionic bond such as a group having a reactive cyclic ether group can be mentioned.

Examples of the groups containing these functional groups include the above-mentioned acidic functional groups, basic functional groups, or curable functional groups, and hydrocarbon chains and bonding groups (collectively referred to as bonding chains). and the like. That is, in the present invention, the reactive functional group includes not only the above-described acidic functional group, basic functional group and curable functional group, but also groups containing these functional groups and bonding chains. Examples of the bond chain include divalent hydrocarbon groups such as alkylene groups and arylene groups, bond groups such as ether, ester, carbonyl and amide groups, and combinations thereof. For example, when 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.

The preferred form of the reactive functional group differs from the viewpoint of various physical properties in 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, an acidic functional group, a basic functional group, or a group containing these functional groups is preferable, and a carboxyl group, a phosphoric acid group, a phosphonic acid group, groups, hydroxyl groups, or groups containing these functional groups are more preferred. From the viewpoint that the resulting sulfur-containing polymer tends to have a low linear expansion coefficient, a carboxyl group, a phosphoric acid group, a phosphonic acid group, a hydroxyl group, or a group containing these functional groups is preferable, and a hydroxyl group or a group containing a hydroxyl group is more preferable. preferable. From the viewpoint of improving the adhesion of the obtained sulfur-containing polymer to the substrate, a carboxyl group, a phosphoric acid group, a phosphonic acid group, or a group containing these functional groups is preferable, and a phosphoric acid group, a phosphonic acid group, Or a group containing these functional groups is more preferable. 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 particle substrates (coatings). , organic substrates such as 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 preferable, and a carboxyl group, a hydroxyl group, an amino group, , maleimide group, vinyl group, (meth)acryloyl group, allyl group, methallyl group, epoxy group, oxetane group, or groups containing these functional groups are more preferred.

Among them, the reactive functional group is a carboxyl group, a phosphoric acid group, a phosphonic acid group, a hydroxyl group, a curable functional group, or a or a group containing these functional groups, more preferably a carboxyl group, a phosphate group, a hydroxyl group, a vinyl group, an epoxy group, or a group containing these functional groups, a phosphate group, More preferably, it is a hydroxyl group, a vinyl group, or a group containing these functional groups. In addition to the high refractive index, the reactive functional group is a carboxyl group, a phosphoric acid group, or a functional A group containing a group is preferred.

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

Examples of the alkoxy group include methoxy, ethoxy, propoxy, isopropoxy, s-butoxy, t-butoxy, pentyloxy, phenoxy, cyclohexyloxy, and benzyloxy groups. Among them, an alkoxy group having 1 to 18 carbon atoms is preferable, an alkoxy group having 1 to 6 carbon atoms is preferable, and a methoxy group is more preferable.

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

The alkyl group, alkoxy group, aryl group, aralkyl group, and sulfur-containing substituent may further have a substituent (substituent B), and the substituent (substituent B) may be an alkyl group, A halogen atom is mentioned, and among them, an alkyl group is preferable from the viewpoint of the solubility of the resulting sulfur-containing polymer, and a halogen atom is preferable from the viewpoint of the dispersibility of the inorganic particles.

In that the refractive index and Abbe number can be further increased, the substituent (substituent A) that the monovalent aromatic hydrocarbon group may have includes the alkyl group having 1 to 18 carbon atoms. , a sulfur-containing substituent are more preferred, a methyl group and a thioalkyl group are more preferred, and a methyl group is particularly preferred. Further, from the viewpoint of improving the dispersibility of the inorganic particles, the substituent that the monovalent aromatic hydrocarbon group may have is more preferably a hydroxyl group or a sulfur-containing substituent, such as a hydroxyl group, a thioalkyl group, or a thioaryl group. A group is more preferred, and a hydroxyl group is particularly preferred.

As the substituent (substituent A) that the monovalent aromatic hydrocarbon group may have, a functional group having a property of being highly compatible with other resins, polymerizable monomers, solvents, etc. is also preferable. . In the present invention, such groups are also referred to as polar substituents.

Examples of the polar substituents include ester functional groups (eg, methyl ester group: -COOCH ₃ ), carbonyl groups (eg, acetyl group: -COCH ₃ ), thiocarbonyl groups (eg, thioacetyl group: -CSCH ₃ ), nitro groups (- NO ₂ ), sulfonyl group (eg methanesulfonyl group: —SO ₂ CH ₃ ), cyano group (—CN), alkoxy group (eg methoxy group: —OCH ₃ ), sulfonate functional group (eg methanesulfonic acid group: —OSO ₂ CH ₃ ), phosphonate functional groups (eg —PO(OCH ₃ ) ₂ ), alkylthio groups (eg —SCH ₃ ), halogen atoms (eg Br, Cl), halogen-containing hydrocarbon groups (eg CH2Cl, CF3) and the like.

The above polar functional groups include not only polar functional groups but also groups containing polar functional groups. The group containing a polar functional group includes, for example, a group having the above 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 the polar functional group is preferably an acetyl group, it means that the polar functional group is preferably an acetyl group and/or a group containing an acetyl group.

When the substituent A is the polar functional group, the resulting sulfur-containing polymer tends to have the property of facilitating the dispersion of inorganic substances. From the same point of view, the substituent A is also preferably an acidic functional group or a basic functional group. 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, and the like are more preferable.

The number of substituents A that the monovalent aromatic hydrocarbon group may have is not particularly limited, but is preferably as small as possible in terms of further increasing the refractive index of the resulting sulfur-containing polymer. Specifically, it is preferably from 1 to 4, more preferably from 1 to 3, even more preferably from 1 to 2, per one monovalent aromatic hydrocarbon group.

In the monovalent aromatic hydrocarbon group, the position where the substituent A is bonded is not particularly limited. The same applies when the above monovalent aromatic hydrocarbon group is a phenyl group, and when the substituent A is, for example, an alkyl group, the bonding position is not particularly limited. preferably.

The diaryldisulfide compound is preferably a diphenylsulfide compound represented by the following general formula (1-1). Further, the thioaryl compound is preferably a compound represented by the following general formula (2-1).

(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; represents a hydrogen atom or a substituent (A-1).)
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. Substituents (A-1) represented by R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ above preferably have reactive functionalities an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, which may have a group, a halogen atom, or a substituent (also referred to as "substituent (B-1)"), or It is a polar substituent. These substituents (A-1) are the same as the substituents (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 them, the substituent (A-1) is more preferably a methyl group or a thioalkyl group, and particularly preferably a methyl group, in that the refractive index of the resulting sulfur-containing polymer can be further increased.

In general formula (1-1) above, among R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ above, substituent (A-1) The number is an integer of 0 to 10, but is preferably 2 to 6, more preferably 2 to 4, in that the resulting sulfur-containing polymer has a higher refractive index. is more preferable. In the above general formula (1-1), among the above R ¹ , R ² , R ³ , R ⁴ and R ⁵ , the number of substituents (A-1) is an integer of 0 to 5, but the obtained It is preferably 1 to 3, more preferably 1 or 2, even more preferably 1, in that the sulfur-containing polymer has a higher refractive index. The same applies to R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ in general formula (1-1) above. The same applies to R ¹ , R ² , R ³ , R ⁴ and R ⁵ in general formula (2-1).

Among R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ and R ¹⁰ in the above general formula (1-1), R ³ and R ⁸ are substituents ( A-1) is preferable. Among R ¹ , R ² , R ³ , R ⁴ and R ⁵ in the general formula (2-1), R ³ is preferably the substituent (A-1).

Specific examples of the diphenyl sulfide compounds 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, 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 disulfide, 2,2′,3,3′,5,5′,6,6′-octaethyldiphenyl disulfide, 2,2′-di Propyldiphenyl 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′,5,5′-hex cycloisopropyldiphenyldisulfide, 2,2',3,3',6,6'-hexaisopropyldiphenyldisulfide, 2,2',3,3',5,5',6,6'-octaisopropyldiphenyldisulfide, etc. is mentioned.

Specific examples of the thiol compounds include 3-methylbenzenethiol, 2-methylbenzenethiol, thiophenol (benzenethiol), 2,3-dimethylbenzenethiol, 2,5-dimethylbenzenethiol, 2,6- dimethylbenzenethiol, 3,5-dimethylbenzenethiol and the like.

The disulfide compounds can also be prepared by oxidation of thiol compounds. Therefore, in the polymerization step, a thiol compound can 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 oxidative bonding is not particularly limited, and a known method can be used.

Polymerization in the production method of the present invention is performed using a solvent containing a cyclic sulfone.
Although the cyclic sulfone is not particularly limited, it is preferably a compound represented by the following general formula (3), for example.

(Wherein, n is an integer of 2 to 8, and R ^a and R ^b each represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms.)
In the above general formula (3), a divalent hydrocarbon chain having 2 to 8 carbon atoms is bonded to the sulfur atom by the carbon atoms at both ends of the hydrocarbon chain to form a cyclic structure. R ^a and R ^b are attached to the carbon atom.

R ^a and R ^b may be the same or different. That is, R ^a and R ^b bonded to any one of n carbon atoms may be the same or different. Moreover, among n carbon atoms, R ^a and R ^b bonded to a certain carbon atom may be the same as or different from R ^a and R ^b bonded to other carbon atoms.

At least one of R ^a and R ^b is preferably a hydrogen atom, and both are preferably hydrogen atoms. Of the total number of R ^a and R ^b bonded to n carbon atoms (2n), n or more are preferably hydrogen atoms, and 2n are more preferably hydrogen atoms. In addition, of the total number of R ^a and R ^b bonded to n carbon atoms (2n), two or more are preferably hydrogen atoms, more preferably three or more are hydrogen atoms, and four It is more preferable that the above are hydrogen atoms, and it is particularly preferable that 2n (all) of them are hydrogen atoms.

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

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

Although the solvent contains cyclic sulfone, it may further contain a solvent other than cyclic sulfone. Preferred solvents for use with cyclic sulfones 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, cyclopentyl methyl ether and the like.

The amount of the solvent used is not particularly limited, but it is preferably 1 to 10,000 parts by mass with respect to 100 parts by mass of the monomer component. From the viewpoint of reactivity, it is more preferably 10 parts by mass or more, and still more preferably 50 parts by mass or more. On the other hand, the upper limit is more preferably 1000 parts by mass or less, still more preferably 500 parts by mass or less, from the viewpoint of economy.

The content of the cyclic sulfone in the solvent is preferably 1 to 100% by mass with respect to 100% by mass of the solvent (total amount). More preferably, it is 10% by mass or more, still more preferably 50% by mass or more, even more preferably 80% by mass or more, and particularly preferably 100% by mass.

The oxidative polymerization is not particularly limited, but oxidative polymerization using a quinone compound and oxidative polymerization using a catalyst are preferable. Oxidative polymerization using a catalyst is more preferable from the viewpoint of reducing the amount of waste liquid.

Oxidative polymerization using a catalyst will be described. In the polymerization step, when the monomer component is polymerized using a solvent containing 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 obtained by dissolving or dispersing the monomer component and the catalyst in the solvent. Also in oxidation polymerization using a catalyst, the preferred amount of solvent used (the amount of solvent relative to the monomer component), the content of cyclic sulfone contained in the solvent, and the preferred solvent other than cyclic sulfone contained in the solvent are described above. As I did.

As the above catalyst, a catalyst (oxidation polymerization catalyst) having oxidation polymerization activity for a monomer component containing a disulfide compound and/or a thiol compound is preferable. The catalyst is not particularly limited, but includes metal elements such as vanadium (V), zirconium (Zr), titanium (Ti), cobalt (Co), nickel (Ni), manganese (Mn), and iron (Fe). Substances are preferred. The form of the substance containing the metal element is not particularly limited, and examples thereof include metals containing the metal element, metal compounds, and other forms.

Examples of the metal include a metal (single substance) consisting only of the metal, and an alloy containing the metal as a main component. The metal compound is not particularly limited as long as it contains a metal, and inorganic compounds, organic acid salts, complexes (coordination compounds) and the like can be mentioned. Examples of the inorganic compounds include halides, sulfates, nitrates, phosphates, silicates, carbonates, hydroxides, oxides, sulfides, tellurides, and intermetallic compounds. Among them, halides are preferred. As the halide, fluoride, chloride, bromide and iodide are preferable, and chloride is more preferable. The organic acid salt is not particularly limited as long as it is an organic acid salt containing a metal element, and examples thereof include carboxylates and sulfonates. As the carboxylate, for example, acetate, oxalate and the like are preferable. As the sulfonate, for example, p-toluenesulfonate, trifluoromethanesulfonate, and the like are preferable. The complex is not particularly limited as long as it contains a metal element. Examples include diketone complexes and β-diketoester complexes. Examples of other forms of the substance containing the metal element include a form in which metal ions such as monovalent ions and trivalent ions of metal are contained as cations in cation exchangers such as zeolite and mica.

Only one kind of the substance containing the metal element may be used, or two or more kinds thereof may be used in combination.
The presence of the catalyst in the raw material composition is not particularly limited. For example, it may be dispersed in the form of particles or the like in the raw material composition, or may exist in a state of being dissolved in a monomer component or a solvent. Similarly, the substance containing the metal element is not particularly limited in its existence form in the raw material composition. For example, it may be dispersed in the raw material composition in the form of particles or the like, or may It may exist in a dissolved state in a component or solvent. Solvents are as described above.
The same applies to the existence form of the catalyst and the existence form of the substance containing the metal element in the reaction composition.

Among the above substances containing metal elements, substances containing vanadium and iron as metal elements (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.

The iron-containing substance preferably contains iron as a main component as a metal element. Specifically, the content of iron is preferably 50 mol% or more, more preferably 80 mol% or more, more preferably 95 mol% with respect to 100 mol% of the total content of the metal elements contained in the iron-containing substance. It is more preferably 98 mol % or more, and particularly preferably 100 mol %. The vanadium-containing substance preferably contains vanadium as a main component as a metal element, and the preferred content of vanadium relative to the total amount of metal elements is the same as the content of iron in the iron-containing substance. Specific forms and preferred forms of the vanadium-containing substance and the iron-containing substance are as described above.

As the vanadium-containing substance, a metal containing vanadium and an oxovanadium compound having a V=O bond in the vanadium compound molecule are preferable. Examples of the oxovanadium compound include vanadyl acetylacetonate, oxovanadium salen complex, N,N'-bissalicylideneethylenediamine oxovanadium, phthalocyanine oxovanadium, tetraphenylporphyrin oxovanadium, etc. Iron-containing substances , iron compounds having chlorine in the molecule are preferred. A compound containing iron having an oxidation number of 3 or more is preferable. Examples of such iron-containing substances include ferric chloride (Fe(Cl) ₃ ), 5,10,15,20-tetraphenyl-21H,23H-porphine iron (III) chloride, iron trifluoromethanesulfonate (III), among others, are particularly preferred.

The amount of the catalyst used in the polymerization is not particularly limited, but the total content of the metal elements contained in the catalyst is in the range of 0.001 to 50 mol% with respect to 100 mol% of the monomer component. is preferable, and from the viewpoint that the removal of the catalyst residue can be done 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. , more preferably 0.01 mol% or more, still more preferably 0.1 mol% or more, and particularly preferably 1 mol% or more, from the viewpoint that a sulfur-containing polymer having a high molecular weight can be easily obtained.

The polymerization is preferably carried out in the presence of oxygen. Conducting the reaction in the presence of oxygen promotes the oxidative polymerization reaction. As 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 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, and the like are employed.

It is considered that the hydrogen desorption reaction from the carbon atoms constituting the aromatic rings contained in the monomer component can be promoted by conducting the above polymerization reaction in the presence of oxygen gas.
In addition, in the polymerization step, the oxidation number of the metal contained in the catalyst can usually change, but by performing the polymerization reaction in the presence of oxygen gas, the valence of the metal contained in the catalyst can be increased to a high oxidation number. It is considered that the oxidative polymerization can be promoted because the oxidative polymerization can be maintained.
From this point of view, the method of continuously supplying the oxygen-containing gas to the reaction composition during the polymerization reaction is preferred, and the method of bubbling is particularly preferred.

The oxygen-containing gas is preferably a gas containing oxygen molecules (O ₂ ). The oxygen-containing gas may contain gas components other than oxygen molecules (O ₂ ). Gas components other than oxygen molecules (O ₂ ) contained in the oxygen-containing gas are not particularly limited, but are preferably helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe ), rare gases such as radon (Rn); and inert gases such as nitrogen (N ₂ ). Carbon dioxide (CO ₂ ), water vapor, etc. may be contained in addition to the inert gas.

The _content of oxygen molecules (O ₂ ) in the oxygen-containing gas is not particularly limited. % is preferably 0.1 to 100% by volume. More preferably, it is 1% by volume or more, and still more preferably 10% by volume or more. The upper limit is more preferably 60% by volume or less, more preferably 30% by volume or less.

_The total content of oxygen molecules (O ₂ ) and inert gas in the oxygen-containing gas is not particularly limited. is preferably 80 to 100% by volume with respect to 100% by volume of the oxygen-containing gas. More preferably, it is 95% by volume or more, and still more preferably 98% by volume or more.

Examples of the oxygen-containing gas include, but are not limited to, oxygen gas, a mixed gas of oxygen and nitrogen, and air. It is preferable to use air from the viewpoint of being excellent in economic efficiency. The water vapor concentration in the oxygen-containing gas is not particularly limited, but is preferably 1000 g/m ³ or less, more preferably 10 g/m ³ or less, still more preferably 1 g/m ³ or less, and most preferably 0.1 g/m ³ or less. , dry air is preferred.

The supply amount of the oxygen-containing gas is not particularly limited, but is preferably 0.0001 m ^{3 /} min to 10 m 3 /min as the supply amount (supply rate) per minute per 1 m ³ of the total volume of the reaction composition. preferable. From the viewpoint of increasing the reaction rate, it is more preferably 0.0005 m ³ /min or more, and still more preferably 0.001 m ³ /min or more. From the viewpoint of easy control of the reaction temperature, the upper limit is more preferably 1 m ³ /min or less, and still more preferably 0.1 m ³ /min or less.

The supply amount of the oxygen-containing gas is also 0.00002 m ^{3 /} min to 2 m ³ /min as the supply amount (supply rate) of oxygen (O ₂ ) per minute per 1 m ³ of the total volume of the reaction composition. Preferably. From the viewpoint of increasing the reaction rate, it is more preferably 0.0001 m ³ /min or more, and still more preferably 0.0002 m ³ /min or more. The upper limit is more preferably 0.2 m ³ /min or less, still more preferably 0.02 m ³ /min or less, from the viewpoint of easy control of the reaction temperature.

It is preferable to use an acid and/or a salt thereof in the polymerization step. By using an acid and/or a salt thereof together with the catalyst, the molecular weight of the polymer obtained by the polymerization reaction can be easily controlled to a high range, and a high-molecular-weight sulfur-containing polymer can be easily obtained even in a short time.

Bronsted acid is preferable as the acid. For example, inorganic acids such as phosphoric acid, phosphonic acid, nitric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, persulfuric acid, sulfurous acid; methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, 10-camphorsulfonic acid, trifluoromethanesulfonic acid sulfonic acids such as , 1,1,2,2-tetrafluoroethanesulfonic acid; carboxylic acids such as acetic acid, trifluoroacetic acid, perfluoropropionic acid, perfluorobutyric acid and benzoic acid;

As the acid, an acid having an acid dissociation constant of -19 to 4 is preferable. 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, hydrobromic acid; methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, sulfonic acids such as 10-camphorsulfonic acid, trifluoromethanesulfonic acid and 1,1,2,2-tetrafluoroethanesulfonic acid; chlorocarboxylic acids such as chloroacetic acid, dichloroacetic acid and trichloroacetic acid; Fluorocarboxylic acids such as fluoroacetic acid, perfluoropropionic acid, perfluorobutyric acid, 4-fluorobenzoic acid, and the like are included. Among them, 10-camphorsulfonic acid, trifluoromethanesulfonic acid, and persulfuric acid are preferred.

The salt of the acid is not particularly limited as long as it is a salt of the acid. Examples include group 1 metal elements of the periodic table such as sodium and potassium; etc. with the above acids are preferred. Among them, for example, sodium persulfate, ammonium persulfate, sodium toluenesulfonate, sodium trifluoromethanesulfonate and the like are preferable. The salt with the acid preferably has a pH of 1 to 6.9, more preferably 2 to 6 at 25° C. when dissolved in pure water.

One of the above acids and/or salts thereof may be used, or two or more thereof may be used. The amount of the acid and/or its salt used is preferably 0.01 to 100 mol%, more preferably 0.1 to 10 mol%, relative to 100 mol% of the monomer component. 0.5 to 5 mol % is more preferable. The amount of the acid and/or its salt used is preferably 0.1 to 1000 mol%, preferably 1 to 100 mol%, with respect to 100 mol% of the total amount of the metal elements contained in the substance containing the metal element. %, more preferably 5 to 50 mol %.

The pH of the entire reaction system to which the acid and/or its salt is added (raw material composition containing the acid and/or its salt) is preferably pH 0.1 to 7, and 1 to 6, from the viewpoint of improving the reaction efficiency. More preferably, 2 to 5 are most preferred. The pH is a value when the reaction system (raw material composition containing an acid and/or its salt) is measured as it is, and is measured using pH test paper and a pH measuring machine.

It is also preferable to use an oxidizing agent in the polymerization step. Examples of the oxidizing agent include, but are not limited to, quinone compounds. Only one kind of the oxidizing agent may be used, or two or more kinds thereof may be used. Among them, quinone compounds are preferred.

Examples of the quinone compound include, but are not limited to, 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, 3,4,5,6-tetrafluoro benzoquinone and the like. Among them, DDQ is preferable because of its high oxidizing power and easy availability. Only one kind of the quinone-based compound may be used, or two or more kinds thereof may be used.

The amount of the oxidizing agent used is preferably 0.01 to 50 mol%, more preferably 0.1 to 20 mol%, more preferably 0.5 to 10 mol%, relative to 100 mol% of the monomer component. More preferably, it is mol %.

The polymerization may be carried out under normal 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 of the solvent. good too. In the above polymerization, the polymerization temperature is not particularly limited as long as it is a temperature at which oxidative polymerization proceeds, but in terms of facilitating the oxidative polymerization reaction with inexpensive equipment, it is preferably 0 to 250° C., more preferably 30° C. or higher. 50° C. or higher is more preferred, while the upper limit is more preferably 200° C. or lower, even more preferably 180° C. or lower. The polymerization time is not particularly limited, but is usually 0.1 to 100 hours, preferably 1 to 80 hours, more preferably 5 to 50 hours, and further preferably 10 to 24 hours. preferable.

In the above polymerization, monomer components may be sequentially added during the polymerization reaction. In the above polymerization, the above-described thiol compound may be oxidatively polymerized to obtain a disulfide compound, and then the obtained disulfide compound is oxidatively polymerized.
A composition (raw material composition) containing the monomer component, the solvent, and the catalyst is preferably held at the polymerization temperature for the polymerization time, so that the polymerization reaction of the monomer component occurs, and sulfur A composition (polymer composition) comprising the polymer is produced.

Oxidative polymerization using a quinone compound will be described. In the oxidative polymerization, the monomer component is polymerized in the presence of a quinone compound. 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 quinone compound. For example, it is more preferable to carry out the polymerization reaction by heating, if necessary, a composition obtained by dissolving or dispersing the monomer component and the quinone compound in the solvent. Also in oxidation polymerization using a quinone compound, the preferred amount of solvent used (the amount of solvent relative to the monomer component), the content of cyclic sulfone contained in the solvent, and the preferred solvent other than cyclic sulfone contained in the solvent, etc. , as described above.

Examples of the quinone compound include, but are not limited to, 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, 3,4,5,6-tetrafluoro benzoquinone and the like. Among them, DDQ is preferable because of its high oxidizing power and easy availability. Only one kind of the quinone-based compound may be used, or two or more kinds thereof may be used.

Moreover, when using the said quinone type compound, it is also preferable to use an acid further. When an acid is used in combination with a quinone compound, the oxidizing power of the quinone compound can be maintained. The acid is not particularly limited, and examples include sulfuric acid, acetic acid, methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfonic acid, 1,1,2,2-tetrafluoroethanesulfonic acid, and trifluoroacetic acid. , perfluoropropionic acid, perfluorobutyric acid and the like. Among them, 1,1,2,2-tetrafluoroethanesulfonic acid is preferable from the viewpoint of increasing acidity. Only one kind of the acid may be used, or two or more kinds thereof may be used.

When the quinone compound and acid are used in combination, the amount of acid added is preferably 10 to 1000 mol, and preferably 50 to 500 mol, per 100 mol of the total amount of the quinone compound to be added. More preferably, it is 80 to 120 mol.
The amount of the quinone compound to be added is preferably 0.1 to 3 mol, more preferably 0.8 to 1.5 mol, more preferably 0.8 to 1.5 mol, per 1 mol of the monomer component used. More preferably 9 to 1.1 mol.

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 of the solvent. may In the above polymerization, the polymerization temperature is not particularly limited as long as it is a temperature at which oxidative polymerization proceeds, but in terms of facilitating the oxidative polymerization reaction with inexpensive equipment, it is preferably 0 to 200° C., more preferably 10° C. or higher. It is preferably 15° C. or higher, while the upper limit is more preferably 180° C. or lower, even more preferably 150° C. or lower. The polymerization time is not particularly limited, but is usually 0.1 to 100 hours, preferably 1 to 80 hours, more preferably 5 to 50 hours, and further preferably 10 to 24 hours. preferable.

The oxidation polymerization using a catalyst and the oxidation polymerization using a quinone compound have been described above as preferred embodiments of the production method of the present invention. In any oxidation polymerization, a sulfur-containing polymer having a repeating structure in which the main chain is a repeating structure in which hydrocarbon chains contained in a disulfide compound and/or a thiol compound are bonded by a sulfide group (-S-) or the like by the above polymerization process. can be obtained. When the diaryl disulfide compound represented by the above general formula (1) and/or the thioaryl compound represented by the above general formula (2) is used as the monomer component, the structural unit (A) described below is usually used. , (B), and (C). Under the preferred conditions described above, a sulfur-containing polymer having a relatively high content of the structural unit (A) among these structural units 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 compound. The effects of the present invention are exhibited.

<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 above polymerization step contains at least the solvent used in the above polymerization step, as well as the catalyst residue and substances derived from the quinone compound used, so-called impurities. These impurities may affect the optical properties, heat resistance, etc. of the sulfur-containing polymer. It is preferable from the viewpoint of improving the quality of the contained polymer. Therefore, it is a preferred embodiment of the production method of the present invention that the production method of the present invention further includes a purification step.

The oxidation step is a step of oxidizing the polymer obtained in the polymerization step. By oxidizing the above polymer, the sulfur atom in the sulfide group (-S-) in the main chain of the sulfur-containing polymer is oxidized to form "-SO-" or " _-SO2- ", which will be described later. It is possible to obtain a sulfur-containing polymer having a high content ratio of the structural unit (B) or the structural unit (C). By including the structural units (B) and (C) or by increasing the proportion thereof, the refractive index, solubility, and the like can be controlled, as will be described later. Therefore, it is a preferred embodiment of the production method of the present invention that the production method of the present invention 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 preferably before the purification step.

The purification process will be described. As a 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 for example, the polymer composition is dropped into methanol acidified with hydrochloric acid to precipitate the polymer, which is filtered to obtain a precipitate, and the obtained precipitate is washed with lower alcohol such as water or methanol. By carrying out 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.

As the purification step, a method using a conventionally known adsorbent such as activated carbon can be used to remove components derived from the oxidizing agent used in the oxidation step and impurity components derived from the polymerization step. It is also preferable to use the reprecipitation method and the method using an adsorbent together. The timing of performing the purification step is not particularly limited, and it may be performed before the oxidation step or after the oxidation step. That is, the polymer obtained after the purification step may be subjected to the oxidation step, or the composition containing the polymer obtained in the oxidation step may be subjected to the purification step. Among them, when the production method of the present invention includes the oxidation step, it is preferable to perform the purification step on the composition containing the polymer obtained after performing both the polymerization step and the oxidation step. It is preferable in that a sulfur-containing polymer containing few impurities derived from the raw materials used in the above can be obtained.

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

The oxidizing agent is not particularly limited, and known oxidizing agents can be used. Tetracyanoethylene, cerium (IV) acetylacetonate, manganese (III) acetylacetonate, peroxides, chloric acid, hypochlorous acid, hypochlorite, compounds capable of generating hypochlorous acid, etc. be done. Among them, the sulfur atom (sulfide group, -S-) contained on the main chain can be moderately oxidized to form a sulfoxide (sulfinyl group) (-SO-), and peroxides, chlorine More preferably, at least one compound selected from the group consisting of acids, hypochlorous acid, hypochlorites, and compounds capable of generating hypochlorous acid is used. Examples of the peroxide include meta-chloroperbenzoic acid, hydrogen peroxide, ammonium persulfate, sodium persulfate, peracetic acid, t-butyl hydroperoxide and the like.

Among them, the oxidizing agent is preferably a peroxide, more preferably meta-chloroperbenzoic acid or hydrogen peroxide. The oxidizing agent is more preferably meta-chloroperbenzoic acid in terms of suppressing oxidation to sulfonyl (—SO ₂ —) with an excess oxidizing agent. Further, when hydrogen peroxide is used as the oxidizing agent, it is possible to use a phase transfer catalyst such as trifluoroacetone while suppressing the amount of water from the viewpoint of suppressing precipitation of the sulfur-containing polymer. preferable. Only one kind of the oxidizing agent may be used, or two or more kinds thereof may be used in combination. It is also preferable to use at least one compound selected from the group consisting of hypochlorous acid, hypochlorite salts, and compounds capable of generating hypochlorous acid as the oxidizing agent.

The amount of the oxidizing agent to be added is not particularly limited as long as the oxidation reaction of the sulfur atoms proceeds to obtain the desired polymer. It is preferably 1000 mol, more preferably 10 to 500 mol, even more preferably 100 to 400 mol.

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. The temperature is preferably 15° C. or higher, more preferably 15° C. or higher, and more preferably 180° C. or lower, even more preferably 150° C. or lower, from the viewpoint of suppressing 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 10 to 24 hours. It is even more preferable to have

When oxidizing to -SO ₂ -, the reaction may be carried out for a longer time than the reaction time described above. The amount of the oxidizing agent to be added in this case is not particularly limited as long as the desired oxidation reaction of the sulfur atom proceeds, but it is usually 1.5 to 100 mol per 1 mol of the sulfur atom in the polymer. preferably 2 to 50 mol, even more preferably 2 to 10 mol.

A solvent may be used in the oxidation reaction. As the solvent to be used, the same solvents as those used in the polymerization step are preferably used.
Since the sulfur-containing polymer obtained by the oxidation step may contain acid or the like, it is preferable to perform the purification step.

The method for producing a sulfur-containing polymer may include other steps in addition to the above-described 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 replacement step, and a dissolution step. These steps can be performed by a known method.

A sulfur-containing polymer can be produced at a high yield by the production method of the present invention described above. Therefore, the sulfur-containing polymer obtained by the production method of the present invention is used alone or as a sulfur-containing polymer composition in combination with other components such as inorganic particles for optical materials, particularly optical applications requiring a high refractive index. First, it can be used for various purposes.

2. Preferred Examples of the Sulfur-Containing Polymer 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 are described below.
In the production method of the present invention, a monomer 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 By using the components, preferred sulfur-containing polymers include, for example, a structural unit (A) represented by the following general formula (4), a structural unit (B) represented by the following general formula (5), and the following A sulfur-containing polymer having at least one structural unit selected from the group consisting of structural units (C) represented by general formula (6) can be obtained.

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

<Constituent unit (A)>
In the structural unit (A) represented by general formula (4) above, X ¹ represents 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 them, the divalent aromatic hydrocarbon group is preferably a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, or a triphenylene group, and is a phenylene group, in that the light dispersion of the polymer becomes smaller. is more preferable.

The substituents that the divalent aromatic hydrocarbon group represented by X ¹ may have and the number thereof are the monovalent aromatic hydrocarbon groups represented by A ¹ in the general formula (1) is the same as in the case of the substituent (A) which may have, including preferred embodiments.

In the divalent aromatic hydrocarbon group, the position where 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. preferably. A plurality of the structural units (A) are preferably contained in the sulfur-containing polymer, and more preferably 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.

(Wherein, R ¹¹ is the same or different, and may have a reactive functional group, a halogen atom, or a substituent, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, Or represents a polar substituent.a represents the number of R ¹¹ and is an integer of 0 to 4.)
When there are a plurality of R ¹¹ , each may be the same or different.

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 that may have a substituent, or a polar substituent represented by R ¹¹ is , respectively, are the same as the substituents and preferred embodiments that the divalent aromatic hydrocarbon group in the general formula (4) may have.
Among them, the above R ¹¹ is more preferably a methyl group or a thioalkyl group, and particularly preferably a methyl group, in that the refractive index can be further increased.

In the above general formula (4-1), the bonding position of the other main chain with respect to the carbon atom (1-position) to which the sulfide group is bonded is not particularly limited, and may be the 2-position or the 3-position. It may be 4th place. Among them, the 2nd or 3rd position is preferred, and the 3rd position is more preferred. Further, when the sulfur-containing polymer contains the structural unit (A-1), it may contain a plurality of structural units (A-1) having different bonding positions.

In general formula (4-1) above, a represents the number of substituents R ¹¹ and is an integer of 0-4. a is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1, since the refractive index is further increased. The position of the substituent R ¹¹ in the general formula (4-1) is not particularly limited, and may be the 2-position, 3-position, or 4-position of the phenylene group. . Among them, the 4th or 2nd position is preferred, and the 4th position is more preferred. A plurality of structural units (A-1) are preferably contained in the sulfur-containing polymer, and more preferably contained as repeating units.

<Constituent unit (B)>
In the structural unit (B) represented by the general formula (5), ^X2 represents a divalent aromatic hydrocarbon group which may have a substituent. As the divalent aromatic hydrocarbon group represented by ^X2 , the same groups as the above-mentioned divalent aromatic hydrocarbon group represented by ^X1 are preferably exemplified. Examples of the substituent that the divalent aromatic hydrocarbon group represented by X ² may have include the substituent that the divalent aromatic hydrocarbon group represented by X ¹ described above may have, and Similar groups are preferably mentioned. The divalent aromatic hydrocarbon group represented by ^X2 or a substituent thereof may be the same as or different from the divalent aromatic hydrocarbon group represented by ^X1 or a substituent thereof. good too. A plurality of the structural units (B) are preferably contained in the sulfur-containing polymer, and more preferably contained as repeating units.
The above structural unit (B) is preferably a structural unit (B-1) represented by the following general formula (5-1) in that it is highly polar due to its solubility and the like.

(Wherein, R ¹² is the same or different and may have a reactive functional group, a halogen atom, or a substituent, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, Or represents a polar substituent.b represents the number of R ¹² and is an integer of 0 to 4.)
When there are a plurality of R ¹² , each may be the same or different.

As 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 that may have a substituent, represented by R ¹² includes the same groups as those represented by R ¹¹ described above. Preferred embodiments of R ¹² are also the same as those represented by R ¹¹ . Among them, the above R ¹² is more preferably a methyl group or a thioalkyl group, and particularly preferably a methyl group, in that the refractive index can be further increased.

In the above general formula (5-1), the bonding position of the other main chain with respect to the carbon atom (1-position) to which the sulfinyl group is bonded is not particularly limited, and may be the 2-position or the 3-position. It may be 4th place. Among them, the 2nd or 3rd position is preferred, and the 3rd position is more preferred. Further, when the sulfur-containing polymer contains the structural unit (B-1), it may contain a plurality of structural units (B-1) having different bonding positions.

In the above general formula (5-1), b represents the number of substituents R ¹² and is an integer of 0-4. b is preferably 1 to 3, more preferably 1 or 2, even more preferably 1, in that the refractive index is further increased. The bonding position of the substituent R ¹² in the general formula (5-1) is the same as in the case of R ¹¹ .
A plurality of the structural units (B-1) are preferably contained in the sulfur-containing polymer, and more preferably contained as repeating units.

<Constituent unit (C)>
In the structural unit (C) represented by the general formula (6), ^X3 represents a divalent aromatic hydrocarbon group which may have a substituent. As the divalent aromatic hydrocarbon group represented by ^X3 , the same groups as the above-mentioned divalent aromatic hydrocarbon group represented by ^X1 are preferably exemplified. The substituent that the divalent aromatic hydrocarbon group represented by X ³ may have includes the substituent that the divalent aromatic hydrocarbon group represented by X ¹ described above may have, and Similar groups are preferably mentioned. The divalent aromatic hydrocarbon group represented by ^X3 or a substituent thereof may be the same as the divalent aromatic hydrocarbon group represented by ^X1 or ^X2 or a substituent thereof, can be different.
A plurality of the structural units (C) are preferably contained in the sulfur-containing polymer, and more preferably contained as repeating units.
The structural unit (C) is preferably a structural unit (C-1) represented by the following general formula (6-1) in terms of high transparency.

(Wherein, R ¹³ is the same or different, and may have a reactive functional group, a halogen atom, or a substituent, an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, Alternatively, represents a polar substituent c represents the number of R ¹³ and is an integer of 0 to 4.)
When there are a plurality of R ¹³ , each may be the same or different.

As 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 that may have a substituent, represented by R ¹³ includes the same groups as those represented by R ¹¹ described above. Preferred embodiments of R ¹³ are also the same as those represented by R ¹¹ . Among them, the above R ¹³ is more preferably a methyl group or a thioalkyl group, and particularly preferably a methyl group, in that the refractive index can be further increased.

In the above general formula (6-1), the bonding position of the other main chain relative to the carbon atom (1-position) to which the sulfonyl group is bonded is not particularly limited, and may be the 2-position or the 3-position. It may be 4th place. Among them, the 2nd or 3rd position is preferred, and the 3rd position is more preferred. When the sulfur-containing polymer contains the structural unit (C-1), it may contain a plurality of structural units (C-1) having different bonding positions.

In general formula (6-1) above, c represents the number of substituents R ¹³ and is an integer of 0-4. c is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1, in terms of further increasing the refractive index. The bonding position of the substituent R ¹³ in the general formula (6-1) is the same as in the case of R ¹¹ .
A plurality of the structural units (C-1) are preferably contained in the sulfur-containing polymer, and more preferably contained as repeating units.

By the polymerization using the monomer component containing the diaryl disulfide compound represented by the general formula (1) and/or the thioaryl compound represented by the general formula (2), the structural units (A), (B ) and (C), a sulfur-containing polymer having at least one structural unit selected from the group consisting of It tends to be higher than the ratio. For example, the content of the structural unit (A) in the sulfur-containing polymer obtained in the polymerization step is preferably 50 to 100 mol% with respect to 100 mol% of the total structural units of the polymer, and 80 to It is more preferably 100 mol %, and even more preferably 95 to 100 mol %. The total content of the structural unit (B) and the structural unit (C) in the polymer is preferably 0 to 50 mol%, preferably 0 to 20 mol%, based on 100 mol% of all structural units. more preferably 0 to 5 mol %.

The content ratio of the structural units (A), (B) and (C) in the sulfur-containing polymer can be adjusted by selecting the conditions during the polymerization reaction, and further the oxidation step is performed. can be prepared by performing

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

The sulfur-containing polymer may be in a form containing only one of the structural units (A), (B) and (C), or in a form containing two structural units. It may be in a form containing three constitutional units. These forms and their content ratios can be appropriately selected according to the purpose and application of the sulfur-containing polymer. For example, since the sulfur-containing polymer can have a higher refractive index, it preferably contains the structural unit (A), and more preferably contains it as a main component. In addition, the sulfur-containing polymer preferably contains the structural unit (B), and more preferably contains it as a main component, in order to achieve both solubility and a high refractive index. Moreover, the sulfur-containing polymer preferably contains the structural unit (C), and more preferably contains it as a main component, in order to achieve both transparency and a high refractive index.

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

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

In the sulfur-containing polymer, the content of the structural unit (C) is preferably 1 to 100 mol% with respect to 100 mol% of the total structural units of the polymer, from the viewpoint of high transparency. It is more preferably up to 100 mol %, still more preferably 50 to 100 mol %. In this case, the total content of the structural unit (A) and the structural unit (B) is preferably 0 to 99 mol%, more preferably 0 to 90 mol%, relative to 100 mol% of all structural units. is more preferred, and 0 to 50 mol % is even more preferred.

In the sulfur-containing polymer, the total content of the structural units (A), (B) and (C) is preferably 50 mol% or more with respect to 100 mol% of the total structural units of the polymer, It is more preferably 80 mol % or more, still more preferably 90 mol % or more, even more preferably 95 mol % or more, and particularly preferably 100 mol %.

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.

Examples of monomers into which the structural unit (D) can be introduced include monomers having a polymerizable double bond and the reactive functional group. Examples of the polymerizable double bond include a vinyl group, a (meth)acryloyl group, an allyl group, a methallyl group, etc. Among them, a (meth)acryloyl group is preferable. Examples of the monomer having the polymerizable double bond and the reactive functional group include 2-carboxyethyl (meth)acrylate, 2-carboxypropyl (meth)acrylate, and 3-carboxy(meth)acrylate. carboxyl group-containing (meth)acrylates such as propyl and 4-carboxybutyl (meth)acrylate; phosphoric acid group-containing (meth)acrylates such as 2-(meth)acryloyloxyethyl acid phosphate; glycidyl (meth)acrylate, 3, epoxy group-containing (meth)acrylates such as 4-epoxycyclohexylmethyl (meth)acrylate; vinyl ether group-containing (meth)acrylates such as 2-(2-vinyloxyethoxy)ethyl (meth)acrylate; and the like.

The content of the structural unit (D) is preferably 0 to 80 mol%, more preferably 0 to 50 mol%, more preferably 0 to 20%, based on 100 mol% of the total structural units of the polymer. It is more preferably mol %, even more preferably 0 to 10 mol %, and particularly preferably 0 to 5 mol %.

The sulfur-containing polymer may have a chain structure, a cyclic structure, or a mixture thereof. Among them, the sulfur-containing polymer preferably has a chain structure as a main component from the viewpoint of excellent solubility and mechanical strength. Specifically, in the sulfur-containing polymer, the content of the polymer having a chain structure is preferably 50% by mass or more, more preferably 80% by mass or more, relative to 100% by mass of the sulfur-containing polymer. , more preferably 95% by mass or more, and particularly preferably 98% by mass or more.

The sulfur-containing polymer preferably has excellent visible light transmittance. For example, the parallel line 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 85% or more. More preferred. The transmittance can be measured with a commercially available spectrophotometer, for example, a spectrophotometer (UV-visible/infrared spectrophotometer V-700 series manufactured by JASCO Corporation).
(Preparation of sample)
A laminate of a colorless and transparent glass substrate and a thin film of a sulfoxide-containing polymer having a thickness of 1 μm formed on one side thereof is used as a measurement sample. The measurement sample can be prepared, for example, by applying a solution of a sulfur-containing polymer in a solvent to a colorless and transparent glass substrate and one side thereof, followed by drying. As a preferred specific example, a solution is prepared by dissolving a sulfur-containing polymer in hexafluoro-2-propanol to a concentration of 5% by mass, and the resulting solution is applied to a glass substrate ( S1111 manufactured by Matsunami Glass Industry Co., Ltd.) is spin-coated at about 500 rpm for 60 seconds and dried at 100° C. for 10 minutes to form a thin film (thickness: 1 μm).

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

The sulfur-containing polymer preferably has a metal content of 10000 ppm or less relative to the sulfur-containing polymer (solid content). The metal content is more preferably 1000 ppm or less, still more preferably 500 ppm or less, and even more preferably 100 ppm or less relative to the polymer. In addition, the metal content is more preferably 0.01 ppm or more relative to the sulfur-containing polymer (solid content) from the viewpoint that the molded product using the sulfur-containing polymer tends to have excellent toughness. It is more preferably 0.1 ppm or more. The metal content can be determined by the ICP emission spectroscopic analysis described above.

In the sulfur-containing polymer, the element content ratio (O/S) between the oxygen atom O bonded to the sulfur atom S in the main chain and the sulfur atom S in the main chain is 0.1 to 1.5. preferable. Transparency and a refractive index become it higher that the said element content ratio is the above-mentioned range. 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 -SO ₂ - in the main chain. The oxygen atom bonded to the sulfur atom S of the main chain specifically means, for example, the oxygen atom O of —SO— in the main chain in the structural unit (B), and the structural unit (C ) means the oxygen atom O of —SO ₂ — in the main chain.

The element content ratio (O / S) is more preferably 0.3 or more, still more preferably 0.5 or more, in that the transparency can be further increased. It is more preferably 1.3 or less, even more preferably 1.1 or less, in that it can be made even higher. The above element content ratio is evaluated using an X-ray photoelectron spectrometer (XPS), and the peak intensities of the oxygen atom 1s orbital (O1s), the carbon atom 1s orbital (C1s), and the sulfur atom 2p orbital (S2p) are evaluated and measured. can be obtained by

The weight average molecular weight (Mw) of the sulfur-containing polymer is preferably 500-10000000. When the weight average molecular weight is within the above range, it can be suitably used as an optical material. From the viewpoint of improving mechanical properties, the weight average molecular weight is more preferably 1000 or more, more preferably 1100 or more, even more preferably 1500 or more. It is more preferably 3,000 or more, even more preferably 10,000 or more, more preferably 1,000,000 or less, and even more preferably 100,000 or less from the viewpoint of reducing the melt viscosity.

The dispersity (weight average molecular weight/number average molecular weight) of the sulfur-containing polymer is preferably 1 or more and 10 or less. Molding|molding becomes it easy that the said dispersion degree is the above-mentioned range. The degree of dispersion is more preferably 5 or less, and even more preferably 3 or less, in that the moldability can be further improved. The weight-average molecular weight and number-average molecular weight can be obtained by measuring by a gel permeation chromatography (GPC) method, and specifically can be obtained by the method described in the examples below. The dispersity can be determined by dividing the weight average molecular weight by the number average molecular weight.

The sulfur-containing polymer preferably has a glass transition temperature (Tg) of 80 to 250°C. When the glass transition temperature is within the above range, molding can be easily performed. The glass transition temperature is more preferably 90° C. or higher, still more preferably 100° C. or higher, from the viewpoint of increasing heat resistance, and is 200° C. or lower from the viewpoint of facilitating molding. is more preferable.
The glass transition temperature was measured using a differential scanning calorimeter (DSC) from a DSC curve obtained by heating from room temperature to 250°C (heating rate of 10°C/min) in a nitrogen gas atmosphere. It can be obtained by a method of evaluation based on the intersection of tangent lines at the point of inflection.

The sulfur-containing polymer preferably has a refractive index of 1.69 or more. When the refractive index is within the above range, various applications such as optical materials (members), machine parts materials, electrical/electronic parts materials, automobile parts materials, civil engineering and construction materials, molding materials, etc., as well as materials for paints and adhesives. It can be widely and suitably used for. The refractive index is more preferably 1.7 or higher, and even more preferably 1.71 or higher.
The refractive index is measured by forming a film with a thickness of 50 nm using the polymer as a measurement sample, using a spectroscopic ellipsometer UVISEL (manufactured by HORIBA Scientific), and using NaD line (589 nm). can ask.

The sulfur-containing polymer preferably has an Abbe number of 10 or more. When the Abbe number is within the above range, the optical material has small light dispersion and is suitable for lenses. The Abbe number is more preferably 15 or more, still more preferably 18 or more, and even more preferably 20 or more. The Abbe number is preferably 60 or less, more preferably 55 or less, from the viewpoint of adjusting the light dispersion.

The Abbe number is measured using the polymer in the same manner as in the measurement of the refractive index, and the D line (589.3 nm) and F line (486.1 nm) are measured using the spectroscopic ellipsometer. , C-line (656.3 nm) is measured, and the following calculation formula can be used.
Abbe number (vD) = (nD-1)/(nF-nC).
In the formula, nD, nF, and nC represent the refractive indices at Fraunhofer's D line (589.3 nm), F line (486.1 nm), and C line (658.3 nm), respectively.

3. Uses 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 and the like. Specific examples of such applications include spectacle lenses, imaging lenses for cameras such as (digital) cameras, mobile phone cameras, and vehicle-mounted cameras, lenses such as light beam condensing lenses, light diffusion lenses, and LEDs. Sealing materials, optical adhesives, optical adhesives, optical transmission bonding materials, filters, diffraction gratings, diffractive optical elements, prisms, light guides, watch glass, transparent glass such as cover glass for display devices and cover glass; photosensors (optical sensors (CMOS sensors, TOF sensors, etc.)), photoswitches, LEDs, micro LEDs, light-emitting elements, optical waveguides, multiplexers, demultiplexers, disconnectors, light Optodevice applications such as dividers and optical fiber adhesives; substrates for display elements such as LCD, organic EL, and PDP, substrates for color filters, substrates for touch panels, index matching materials used for touch panels, display protective films, display backlights, etc. , light guide plates, antireflection films, antifogging films, and display device applications such as light extraction improvers such as LEDs and organic ELs. 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 preferable. Moreover, the sulfur-containing polymer obtained by the production method of the present invention usually tends to have a wide range of absorption in the visible region and the infrared region. Such polymers are also suitable for use as optical materials in the visible and infrared regions.

The sulfur-containing polymer obtained by the production method of the present invention and the sulfur-containing polymer composition containing the polymer can be used not only for optical applications but also for mechanical parts materials, electric/electronic parts materials, automobile parts materials, civil engineering and construction materials, In addition to molding materials, it is used for various purposes such as materials for paints and adhesives. For example, the sulfur-containing polymer obtained by the production method of the present invention usually tends to have excellent heat resistance. separators, filters such as gas separation membranes and liquid separation membranes, electrode materials for fuel cells and Li batteries, and battery members such as electrolyte materials. In addition, it can be suitably used as an insulating material, an antenna material, etc., utilizing low dielectric properties.

A sulfur-containing polymer obtained by the production method of the present invention and a sulfur-containing polymer composition containing the polymer can be suitably used as a molding material. Examples of the molding method include molds such as conventionally known injection molding, T-die method, inflation method, imprint molding, and nanoimprint molding, and molding using resin molds. It may be molded into a desired shape by a method such as casting or coating. The shape is not particularly limited, and includes various known shapes such as lenses, sheets, and films.

In addition, the sulfur-containing polymer obtained by the production method of the present invention and the sulfur-containing polymer composition containing the polymer can be obtained by a conventionally known etching process such as plasma etching and a conventionally known resist process utilizing a solubility difference. It can be suitably used for processing. It can also be suitably used for coating by spin coating, bar coating, squeegee coating, inkjet coating, and the like. 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 good workability, and has a low viscosity, so that it can be molded into fine particles. A curable resin composition is preferable in terms of good conformability to molds and resin molds.
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.

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited only to these examples. Unless otherwise specified, "part" means "mass part" and "%" means "mass %".
Polymers obtained in Examples and Comparative Examples, sulfide-containing polymers used in Examples, etc. were evaluated according to the following methods.

<Weight average molecular weight (Mw)>
A gel permeation chromatography (GPC) method was used to determine the weight average molecular weight of the polymer under the following conditions.
Apparatus 1: SHIMAZU, CBM-20A.
Apparatus 2: Agilent Technologies 1260 Infinity.
Detectors: Refractive Index Detector (RI) (SHIMAZU, SPD-20MA) and UV-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.

<MALDI (time-of-flight mass spectrometry)>
The obtained polymer was subjected to MALDI measurement under the following conditions.
Apparatus: time-of-flight mass spectrometer (Bruker AutoflexIII)
Sample preparation: Dissolve about 2 mg of a sample to be measured 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, and prepare a solution for measurement. After coating on the target plate, it was dried at room temperature for about 100 minutes.

< ¹ H-NMR>
The obtained polymer was subjected to ¹ H-NMR measurement under the following conditions.
Apparatus: Nuclear magnetic resonance apparatus (400 MHz) manufactured by JEOL Ltd.
Measurement solvent: heavy dichloromethane, heavy chloroform.
Sample preparation: Several mg to several tens of mg of the obtained polymer were dissolved in a measurement solvent.

<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.

<Binding energy>
Using a sample formed by spin-coating 0.25 ml of the polymer solution on a silicon wafer, a photoelectron spectrometer manufactured by JEOL (JPS-9010TR, XPS device) was used to determine the 2p3/2 orbit of sulfur atoms. Binding energy was measured from the peak position.

<Organic Elemental Analysis>
The obtained polymer was subjected to elemental analysis using the following equipment, and the contents of C, H, S and O were determined.
Apparatus: Jay Science Lab JM10.

(Synthesis of monomer)
[Synthesis Example 1]
Methanol (1.1 L) was added to a 2.0 L three-necked flask, then 98% sulfuric acid (4.7 mL) was gradually added and stirred. After stirring, 2,2'-dithiodibenzoic acid (101.10 g, 0.33 mol) was added and heated under 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 pure water in that order, and vacuum-dried at room temperature for 4 hours to obtain 2,2'-dithiodibenzoic acid. Dimethyl was recovered. Yield was 99%. Analysis by ¹ H-NMR, ¹³ C-NMR, XPS and FAB-MS confirmed the structure of the product.

(Synthesis of sulfur-containing polymer)
[Example 1]
In a 50 mL test tube, diphenyl disulfide (10.92 g, 50.00 mmol), dimethyl 2,2′-dithiodibenzoate (3.34 g, 10.00 mmol) obtained in Synthesis Example 1, iron chloride (III ) (486.57 mg, 3.00 mmol), (+)-CSA ((+)-10-camphorsulfonic acid) (140.77 mg, 0.600 mmol), Na ₂ S ₂ O ₈ (sodium peroxodisulfate) ( 128.57 mg, 0.600 mmol) and 12 mL of sulfolane as solvent were added. Next, while heating the test tube to 160° C., nitrogen flow (20 mL/min) was performed for 10 minutes, and then air bubbling (20 mL/min) was switched to conduct oxidative polymerization by stirring for 40 hours. After stirring, the mixture was cooled to room temperature, added with THF (100 mL) as a solvent, and stirred for 10 minutes. Then, the resulting reaction solution was added dropwise to 1.0 L of a 3% methanol solution acidified with hydrochloric acid to reprecipitate the polymer. After reprecipitation, the precipitate was filtered through Kiriyama and washed with methanol and pure water. Then, the obtained powder was vacuum-dried at room temperature to obtain a brown polymer (Po1) powder. Yield was 85%. The structure of the obtained polymer (Po1) was identified by various analyses, such as ¹ H-NMR, GPC, IR and elemental analysis. As a result, ¹ H-NMR (CD ₂ Cl ₂ , 400 MHz, ppm): δ = 8.13 (m, 1H), δ = 7.23 (m, 27H), δ = 3.95 (m, 3H) , from IR, a peak derived from an ester group was observed near 1730 cm, and by elemental analysis, H = 4.2%, C = 66.0%, S = 24.6%, O = 5.2%. The composition (polyarylene sulfide) was confirmed.

[Example 2]
Diphenyl disulfide (218.33 g, 1.00 mol), dimethyl 2,2'-dithiodibenzoate (66.88 g, 0.20 mol) obtained in Synthesis Example 1, and iron chloride were placed in a 1.0 L three-necked flask. (III) (9.73 g, 60.00 mmol), (+)-CSA ((+)-10-camphorsulfonic acid) (2.79 g, 12.00 mmol), Na ₂ S ₂ O ₈ (sodium peroxodisulfate ) (2.86 g, 12.00 mmol) and 240 mL of sulfolane as solvent were added. Next, while heating the three-necked flask to 160° C., nitrogen flow (20 mL/min) was performed for 10 minutes, and then air bubbling (150 mL/min) was switched to conduct oxidative polymerization by stirring for 48 hours. After polymerization, the mixture was cooled to room temperature, added with THF (100 mL) as a solvent, and stirred for 10 minutes. Then, the resulting reaction solution was added dropwise to 1.0 L of a 3% methanol solution acidified with hydrochloric acid to reprecipitate the polymer. After reprecipitation, the precipitate was filtered through Kiriyama and washed with methanol and pure water. Then, the obtained powder was 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 identified by various analyses, such as ¹ H-NMR, GPC, IR and elemental analysis. As a result, ¹ H-NMR (CD ₂ Cl ₂ , 400 MHz, ppm): δ = 8.13 (m, 1H), δ = 7.23 (m, 25H), δ = 3.95 (m, 3H) , from IR, a peak derived from an ester group was observed near 1730 cm, and elemental analysis revealed that H = 4.3%, C = 63.8%, S = 26.0%, and O = 5.9%. The composition (polyarylene sulfide) was confirmed.

[Comparative Example 1]
In a 50 mL test tube, diphenyl disulfide (10.92 g, 50.00 mmol), dimethyl 2,2′-dithiodibenzoate (3.34 g, 10.00 mmol) obtained in Synthesis Example 1, iron chloride (III ) (486.57 mg, 3.00 mmol), (+)-CSA ((+)-10-camphorsulfonic acid) (140.77 mg, 0.600 mmol), Na ₂ S ₂ O ₈ (sodium peroxodisulfate) ( 128.57 mg, 0.600 mmol) was added. Next, while heating the test tube to 160° C., nitrogen flow (20 mL/min) was performed for 10 minutes, then air bubbling (150 mL/min) was switched to and stirring was performed for 180 hours to perform oxidative polymerization. After stirring, the mixture was cooled to room temperature, added with THF (100 mL) as a solvent, and stirred for 10 minutes. Then, the resulting reaction solution was added dropwise to 1.0 L of a 3% methanol solution acidified with hydrochloric acid to reprecipitate the polymer. After reprecipitation, the precipitate was filtered through Kiriyama and washed with methanol and pure water. Then, the obtained powder was vacuum-dried at room temperature to obtain a brown polymer (Po3) powder. Yield was 62%. The structure of the obtained polymer (PoC1) was identified by various analyses, such as ¹ H-NMR, GPC, IR and elemental analysis. As a result, ¹ H-NMR (CD ₂ Cl ₂ , 400 MHz, ppm): δ = 8.13 (m, 1H), δ = 7.23 (m, 29H), δ = 3.95 (m, 3H) , from IR, a peak derived from an ester group was observed near 1730 cm, and by elemental analysis, H = 4.3%, C = 64.9%, S = 25.2%, O = 5.0%. The composition (polyarylene sulfide) was confirmed.

In Examples 1 and 2, compared with Comparative Example 1, the sulfur-containing polymer was obtained with a higher molecular weight, a shorter reaction time, and a higher yield.

Claims (2)

A method for producing a sulfur-containing polymer by polymerizing a monomer component containing a disulfide compound and/or a thiol compound,
A method for producing a sulfur-containing polymer, wherein the polymerization is carried out using a solvent containing a cyclic sulfone. 2. The method for producing a sulfur-containing polymer according to claim 1, wherein said polymerization is carried out in the presence of a catalyst.