JP2023012653A - Manufacturing method of sulfur-containing polymer, sulfur-containing polymer, and sulfur-containing polymer composition - Google Patents

Abstract

To provide a method for efficiently manufacturing a sulfur-containing polymer excellent in light permeability and favorably usable as an optical material with a high refractive index.SOLUTION: A manufacturing method is for a sulfur-containing polymer including at least one kind of constitutional unit selected from a group consisting of: a constitutional unit (A) expressed by a phenyl sulfide structural unit which may have a substituent group on its ring; a constitutional unit (B) expressed by a phenyl sulfoxide structural unit which may have a substituent group on its ring; and a constitutional unit (C) expressed by a phenylsulfone structural unit which may have a substituent group on its ring. The manufacturing method of a sulfur-containing polymer includes: a step of polymerizing monomer components by using a heavy metal catalyst; and a step of removing the heavy metal catalyst in the polymer composition containing the polymer obtained at the polymerization step and the heavy metal catalyst.SELECTED DRAWING: None

Description

The present invention relates to a method for producing sulfur-containing polymers, sulfur-containing polymers, and sulfur-containing polymer compositions. More specifically, the present invention relates to a sulfur-containing polymer produced using a heavy metal catalyst and having excellent light transmittance, a method for producing the same, and a composition containing the sulfur-containing polymer.

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, a thermosetting material has been conventionally developed as a lens material for spectacles. However, thermosetting materials have the disadvantage of increasing the number of steps for molding and processing, and thermoplastic materials have been desired in terms of productivity.

Various studies have been made so far on thermoplastic materials with a high refractive index and a small light dispersion.
For example, Patent Document 1 discloses a molding material having a polyarylene sulfide skeleton in which two hydrogen atoms of a benzene ring are substituted with methyl groups, as a molding material that is excellent in moldability in a solution state and can be used as an optical member. Have been described.
Further, for example, Patent Document 2 describes 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. Molding compositions having a radically substituted polyarylene sulfide skeleton are described.

JP 2015-168790 A JP 2017-52834 A

As a method for producing a molding material having a polyarylene sulfide skeleton described above, a disulfide compound or a thiol compound is oxidized using an oxidizing agent such as 2,3-dichloro-5,6-dicyano-parabenzoquinone (DDQ) or a catalyst. Methods for polymerizing are known. However, when the oxidizing agent is used for production, although a polymer having good optical properties can be obtained, there is a problem that the production cost is high and a large amount of waste is generated.

An object of the present invention is to provide a method for efficiently producing a sulfur-containing polymer that has excellent light transmittance and can be suitably used as an optical material with a high refractive index.

The present inventors have made various studies on methods for producing sulfur-containing polymers such as polyarylene sulfide polymers, and have found that when polymerization is performed using a heavy metal catalyst such as a vanadium compound or an iron compound, the polymer can be easily produced using a small amount. Although obtained, the heavy metal catalyst remains in the polymer and has been found to reduce the light transmittance of the polymer. They have also found that a polymer having a high refractive index and excellent light transmittance can be efficiently obtained by removing the heavy metal catalyst in the production process of the sulfur-containing polymer. In addition, the inventors have found that the sulfur-containing polymer thus obtained is excellent in resistance to heat coloration, and have completed the present invention.

That is, the present invention provides a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (3) represented by the following general formula A method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of structural units (C), the method comprising the steps of polymerizing a monomer component using a heavy metal catalyst; 3. A method for producing a sulfur-containing polymer, comprising the step of removing the heavy metal catalyst in the polymer composition containing the polymer obtained in the polymerization step and the heavy metal catalyst.

(In formulas (1) to (3), X ¹ , X ² and X ³ are the same or different and represent a divalent aromatic hydrocarbon group which may have a substituent.)

The structural unit (A) is a structural unit (A-1) represented by the following general formula (1-1), and the structural unit (B) is represented by the following general formula (2-1). The structural unit (B-1) and the structural unit (C) are preferably structural units (C-1) represented by the following general formula (3-1).

(In formulas (1-1), (2-1) and (3-1), R ¹ , R ² and R ³ are the same or different and have a reactive functional group, a halogen atom or a substituent represents an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent group, a represents the number of R ¹ and is an integer of 0 to 4. b represents the number of R ² represents an integer of 0 to 4.c represents the number of R ³ and is an integer of 0 to 4.)

In the method for producing a sulfur-containing polymer, the step of removing the heavy metal catalyst in the polymer composition is preferably performed using activated carbon.

In the above method for producing a sulfur-containing polymer, after the step of removing the heavy metal catalyst in the polymer composition, the heavy metal content is preferably 100 ppm or less relative to the sulfur-containing polymer.

The present invention also provides a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structure represented by the following general formula (3) A sulfur-containing polymer having at least one structural unit selected from the group consisting of units (C), wherein the amount of heavy metal is 0.0001 ppm or more and 100 ppm or less with respect to the sulfur-containing polymer. It is a sulfur-containing polymer that

(In formulas (1) to (3), X ¹ , X ² and X ³ are the same or different and represent a divalent aromatic hydrocarbon group which may have a substituent.)

The sulfur-containing polymer is preferably for optical use.

The present invention is also a sulfur-containing polymer composition characterized by containing the above-described sulfur-containing polymer and an inorganic substance.

According to the present invention, a sulfur-containing polymer having a high refractive index and excellent light transmittance can be efficiently produced. The sulfur-containing polymer obtained by the production method of the present invention is also excellent in resistance to heat coloration, and can be suitably used for optical applications such as imaging system lens materials.

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.

1. The method for producing a sulfur-containing polymer The present invention provides a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (B) represented by the following general formula (3). ) is a method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of structural units (C) represented by A method for producing a sulfur-containing polymer, comprising a step of polymerizing, and a step of removing the heavy metal catalyst in the polymer composition containing the polymer obtained in the polymerization step and the heavy metal catalyst.

(In formulas (1) to (3), X ¹ , X ² and X ³ are the same or different and represent a divalent aromatic hydrocarbon group which may have a substituent.)

The method for producing a sulfur-containing polymer of the present invention can easily obtain a sulfur-containing polymer having a high refractive index and excellent light transmittance. A sulfur-containing polymer having a high refractive index and excellent light transmittance can be easily obtained by the method for producing a sulfur-containing polymer of the present invention. can be removed and side reactions can be suppressed during heating.

The production method of the present invention includes the structural unit (A) represented by the general formula (1), the structural unit (B) represented by the general formula (2), and the general formula (3). is a method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of structural units (C). Each structural unit of the sulfur-containing polymer obtained by the production method of the present invention will be described first.

<Constituent unit (A)>
In the structural unit (A) represented by general formula (1) 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 substituent (also referred to as "substituent A") that the divalent aromatic hydrocarbon group may have is preferably a reactive functional group, a halogen atom, or a substituent ("substituent B , aryl, aralkyl, or sulfur-containing substituents, which may have a

Examples of the reactive functional groups include carboxyl group (--COOH), phosphoric acid group (--OPO(OH) ₃ ), hydroxyl group (--OH), sulfo group (--SO ₃ H), sulfate group (--OSO ₃ H), acidic functional groups such as phosphonic acid group (-PO(OH) ₃ ), phosphinic acid group (-PO(OH)-), mercapto group (-SH); amino group, ammonium group, imino group, amide group , an imide group, a maleimide group, a basic functional group such as a cyano group; a group having a reactive unsaturated bond (e.g., a group having a reactive double bond; Acryloyl group, allyl group, methallyl group, etc.) and groups having reactive ionic bonds (for example, groups having reactive cyclic ether groups, typical examples of which are epoxy groups, oxetane groups, etc.). functional groups; and groups containing these functional groups.

Examples of the groups containing these functional groups include groups having the aforementioned acidic functional groups, basic functional groups, or curable functional groups, and hydrocarbon chains or bonding groups. 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.

Among the above reactive functional groups, for example, from the viewpoint of improving the dispersibility of inorganic particles, 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, Phosphonic acid groups, hydroxyl groups, or groups containing these functional groups are more preferred.
From the viewpoint of a low coefficient of linear expansion, a carboxyl group, a phosphoric acid group, a phosphonic acid group, a hydroxyl group, or a group containing these functional groups is preferred, and a hydroxyl group or a group containing a hydroxyl group is more preferred.
From the viewpoint of improving the adhesion 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 functional group containing these groups are more preferred. 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 these functional groups in that it can provide a higher refractive index along with excellent physical properties. It is preferably a group containing a carboxyl group, a phosphate group, a hydroxyl group, a vinyl group, an epoxy group, or more preferably a group containing these functional groups, a phosphate group, a hydroxyl group, a vinyl group, or these is more preferably a group containing a functional group of
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 polymer, and a halogen atom is preferable from the viewpoint of the dispersibility of the inorganic particles.

Among them, the substituent (substituent A) that the divalent aromatic hydrocarbon group may have in that the refractive index and Abbe number can be further increased, is 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 inorganic particles, the substituent that the divalent 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.

The number of substituents A that the divalent 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 polymer. Specifically, It is preferably 1 to 6, more preferably 1 to 3, even more preferably 1.

The structural unit (A) is preferably a structural unit (A-1) represented by the following general formula (1-1) in that the refractive index becomes higher.

(Wherein, R ¹ is the same or different and is an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent which may have a reactive functional group, a halogen atom, or a substituent. a represents the number of R ¹ and is an integer of 0 to 4.)
When there is more than one R ¹ , each may be the same or different.

A reactive functional group, a halogen atom, or an optionally substituted alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent represented by R ¹ is represented by the general formula It is preferably the same as the substituent that the divalent aromatic hydrocarbon group in (1) may have.

Among them, the above R ¹ 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 general formula (1-1) above, a represents the number of substituents R ¹ 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.

<Constituent unit (B)>
In the structural unit (B) represented by the general formula ( ² ), 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.

The above structural unit (B) is preferably a structural unit (B-1) represented by the following general formula (2-1) in that it is highly polar due to its solubility and the like.

(Wherein, R ² is the same or different and is an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent which may have a reactive functional group, a halogen atom, or a substituent. and b represents the number of R ² and is an integer from 0 to 4.)
When there is more than one R ² , they may be the same or different.

Reactive functional groups, halogen atoms, or alkyl groups, alkoxy groups, aryl groups, aralkyl groups, or sulfur-containing substituents that may have substituents represented by R ² include the above-described R Groups similar to those represented by ¹ can be mentioned.
Among them, the above R ² 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 (2-1), b represents the number of substituents R ² 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.

<Constituent unit (C)>
In the structural unit (C) represented by general formula ( ³ ) above, 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.

The structural unit (C) is preferably a structural unit (C-1) represented by the following general formula (3-1) in terms of high transparency.

(Wherein, R ³ is the same or different and is an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent which may have a reactive functional group, a halogen atom, or a substituent. and c represents the number of R ³ and is an integer of 0 to 4.)
When there is more than one R ³ , they may be the same or different.

The alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent which may have a reactive functional group, halogen atom, or substituent represented by R ³ may be the above-described R Groups similar to those represented by ¹ can be mentioned.
Among them, the above R ³ 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 general formula (3-1) above, c represents the number of substituents R ³ 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 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, the sulfur-containing polymer preferably contains the structural unit (A), and more preferably contains it as a main component, because it can have a higher refractive index.
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 preferably has the above-described reactive functional groups at the ends of the main chain and/or side chains. By having the reactive functional group at least at the end of the main chain or the side chain, excellent physical properties due to the reactive functional group can be exhibited in addition to a high refractive index.
The case of having the reactive functional group in the side chain means not only the case where the side chain of the sulfur-containing polymer has the reactive functional group, but also the structure represented by the general formulas (1) to (3). The case where the substituent in the units (A) to (C) is the above reactive functional group or a group containing the above reactive functional group is also included.

The production method of the present invention comprises a step (1) of polymerizing a monomer component using a heavy metal catalyst, and removing the heavy metal catalyst from the polymer composition containing the polymer obtained in the above polymerization step and the heavy metal catalyst. (2). Each step will be described below.

<Step (1)>
The production method of the present invention has a step (1) of polymerizing a monomer component using a heavy metal catalyst. By polymerizing the monomer components using a heavy metal catalyst, the desired polymer can be easily produced with the addition of a small amount.

The heavy metal catalyst is not particularly limited as long as it is a compound containing a heavy metal that can be usually used as a catalyst, and vanadium compounds, zirconium compounds, titanium compounds, cobalt compounds, nickel compounds, manganese compounds, iron compounds and the like mentioned. Among them, vanadium compounds and iron compounds are preferable, and vanadium compounds are more preferable, in terms of having high reactivity.
The above heavy metal catalysts may be used alone or in combination of two or more.

The vanadium compound is not particularly limited as long as it functions as an oxidation polymerization catalyst. Among them, an oxovanadium compound having a V=O bond in the molecule is preferable. Examples of the oxovanadium compound include vanadyl acetylacetonate, oxovanadium salen complex, N,N'-bissalicylideneethylenediamine oxovanadium, phthalocyanine oxovanadium, tetraphenylporphyrin oxovanadium, and the like.

The iron compound is not particularly limited as long as it functions as an oxidation polymerization catalyst, but iron chloride compounds having chlorine in the molecule are particularly preferable. Examples of the iron chloride compound include ferric chloride (FeCl ₃ ), 5,10,15,20-tetraphenyl-21H,23H-porphine iron (III) chloride, and the like. In addition, iron (III) trifluoromethanesulfonate is also preferred.

The amount of the heavy metal catalyst used is not particularly limited, but is preferably 0.005 parts by mass or more with respect to 100 parts by mass of the total amount of monomer components, and 0.01 part by mass, in terms of being able to increase reactivity. It is more preferably at least 0.1 part by mass, and even more preferably at least 0.1 part by mass. In addition, the amount of the heavy metal catalyst used is preferably 10 parts by mass or less, and 1 part by mass or less with respect to 100 parts by mass of the total amount of the monomer components, in that it can suppress side reactions. is more preferred.

In the polymerization step, the monomer components are polymerized in the presence of the heavy metal catalyst. The polymerization is preferably oxidative polymerization.
The monomer component is not particularly limited as long as it is a monomer that can be polymerized to give the above-described structural units (A) to (C). Preferred examples include disulfide compounds and thiol compounds, Diaryl disulfide compounds represented by the following general formula (4) and thioaryl compounds represented by the following general formula (5) are more preferred.

(In formulas (4) and (5), A ¹ and A ² are the same or different and represent a monovalent aromatic hydrocarbon group which may have a substituent.)
The monovalent aromatic hydrocarbon group represented by A ¹ and A ² is an aromatic hydrocarbon obtained by making the divalent aromatic hydrocarbon group represented by X ¹ in the general formula (1) monovalent. Examples include hydrogen groups, such as phenyl, naphthyl, anthryl, triphenyl, biphenyl, and phenanthryl groups. 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 substituents that the monovalent aromatic hydrocarbon group represented by A ¹ and A ² may have and the number thereof are the divalent aromatic hydrocarbon groups represented by X ¹ in the general formula (1) It is the same as the substituent that the hydrocarbon group may have.

The diaryl disulfide compound is preferably a compound represented by the following general formula (4-1).
The thioaryl compound is preferably a compound represented by the following general formula (5-1).

(In formulas (4-1) and (5-1), R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are the same or different, hydrogen atom, halogen atom , represents an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent which may have a reactive functional group or a substituent.)
The halogen atom, the reactive functional group, or the alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent, which may have a substituent, is represented by the general formula (1-1) described above. is the same as each group represented by R ¹ in .
Further, the substituents that these groups may have include the same as the substituent B described above, but among them, halogen atoms and hydroxyl groups are preferred.

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.

In the polymerization, in addition to the heavy metal catalyst described above, a normal oxidizing agent used for oxidative polymerization may be used. Examples of the oxidizing agent include quinone compounds, hydrogen peroxide, perbenzoic acid, metachloroperbenzoic acid, lead tetraacetate, thallium acetate, tetracyanoquinodimethane, tetracyanoethylene, cerium (IV) acetylacetonate, and manganese. (III) Acetylacetonate and the like can be mentioned, and among them, quinone-based oxidizing agents are preferred.
Only one kind of the oxidizing agent may be used, or two or more kinds thereof may be used.

Specific examples of the quinone-based oxidizing agent include 2,3-dichloro-5,6-dicyano-parabenzoquinone (DDQ), 2,3,5,6-tetrachloroparabenzoquinone (chloranil), 2 ,3,5,6-tetrabromobenzoquinone (bromanyl), 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 (orthochloranil), 3,4,5,6-tetrabromoorthobenzoquinone (orthobromanyl), 3,4,5,6-tetrafluorobenzoquinone and the like. Among them, DDQ is preferable because of its high oxidizing power and easy availability. Only one kind of the quinone-based oxidizing agent may be used, or two or more kinds thereof may be used.

Moreover, it is also preferable to use an acid as the oxidizing agent. The acid may be used in combination with the quinone-based oxidizing agent. When an acid is used in combination with a quinone-based oxidizing agent, the oxidizing power of the quinone-based oxidizing agent 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-based oxidizing agent and the 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-based oxidizing agent to be added. is more preferred, and 80 to 120 mol is even more preferred.

The amount of the oxidizing agent added is preferably 0.1 to 3 mol, more preferably 0.8 to 1.5 mol, more preferably 0.9 mol, per 1 mol of the monomer component used. More preferably ~1.1 mol.

In the polymerization step, the polymerization temperature is not particularly limited as long as it is a temperature at which oxidative polymerization proceeds, but is preferably 0 to 200° C., more preferably 10° C. or higher, in terms of facilitating the progress of oxidative polymerization. 15° C. or higher is more preferable, and 180° C. or lower is more preferable, and 150° C. or lower is even more preferable in that side reactions can be suppressed.

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.

A solvent may be used in the polymerization. Preferred solvents 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.
As the solvent, it is preferable to reduce halogens such as chloroform and chlorobenzene, which are highly harmful to the environment, particularly halogen solvents containing chlorine and bromine. It is preferably 100% by mass or less, more preferably 50% by mass or less, still more preferably 10% by mass or less, and even more preferably 1% by mass or less with respect to the coalescence.

In the above polymerization, monomer components may be sequentially added during the polymerization reaction.
In the polymerization step, the above-described thiol compound may be oxidatively polymerized to obtain a disulfide compound, and then the resulting disulfide compound may be oxidatively polymerized.
After the polymerization step, a polymer composition containing at least a polymer obtained by polymerizing the monomer components and the heavy metal catalyst is obtained.

<Step (2)>
The production method of the present invention includes step (2) of removing the heavy metal catalyst from the polymer composition containing the polymer (polymer P) obtained in the above polymerization step and the heavy metal catalyst.

The method for removing the heavy metal catalyst is not particularly limited, and may be performed by a known method. For example, removal by magnetic adsorption of a heavy metal catalyst having magnetism, or precipitation of a heavy metal catalyst by oxidation-reduction is used. Alternatively, a method of removing the heavy metal catalyst in the polymer composition by contacting the polymer composition with activated carbon to adsorb the heavy metal catalyst to the activated carbon. Among them, the method using activated carbon is preferable from the viewpoint of the removal efficiency of the heavy metal catalyst. Examples of the method using activated carbon include a method of adding activated carbon to the polymer composition, stirring, and then removing the activated carbon by filtration or the like, and a method of adding the polymer composition to a column filled with activated carbon. and a method of flushing.

The activated carbon used in the present invention is not particularly limited, and various known activated carbons such as coconut shell-based activated carbon, wood-based activated carbon, coal-based activated carbon, chemical-activated activated carbon, and gas-activated activated carbon can be used. These may be used alone or in combination of two or more. Among them, the activated carbon is preferably coconut shell-based activated carbon, chemically activated carbon, or gas activated carbon, and more preferably chemically activated carbon, because of its higher removal efficiency of the heavy metal catalyst.

The specific surface area of the activated carbon is preferably from 100 to 10,000 m ² /g, more preferably from 500 to 8,000 m ² /g, and even more preferably from 700 to 5,000 m ² /g, in terms of a larger adsorption treatment capacity. is more preferred. The specific surface area can be determined by a gas adsorption method.

The pore volume of the activated carbon is preferably 0.01 to 1000 mL/g, more preferably 0.1 to 100 mL/g, more preferably 0.3 to 10 mL/g, in terms of a larger adsorption treatment amount. g is more preferred. The pore volume can be determined by gas adsorption method (pore diameter 0.1 to 500 nm) or mercury porosimetry (pore diameter 5 to 5000 nm).

From the viewpoint of removing the heavy metal catalyst, the diameter distribution of the pores of the activated carbon is preferably such that mesopores (2 to 50 nm) account for 10 vol% or more of the pore volume, more preferably 30 vol% or more. More preferably 50 vol% or more, particularly preferably 80 vol% or more. The pore diameter distribution can be determined by a gas adsorption method (pore diameter 0.1 to 500 nm) or a mercury intrusion method (pore diameter 5 to 5000 nm).

From the viewpoint of removal of the heavy metal catalyst, the average diameter of the pores of the activated carbon is preferably 0.1 to 100 nm, more preferably 1 to 80 nm, even more preferably 2 to 50 nm. The average diameter of the pores can be determined by a gas adsorption method (pore diameter 0.1 to 500 nm) or a mercury intrusion method (pore diameter 5 to 5000 nm).

The shape of the activated carbon is not particularly limited, and may be any shape such as fibrous, powdery, or granular. is more preferable.

A commercially available product may be used as the activated carbon. Examples of commercially available activated carbon that can be used in the present invention include Shirasagi ANOX-1, Shirasagi ANOX-2, Shirasagi P (all manufactured by Osaka Gas Chemicals Co., Ltd.), Taiko SA1000, and Taiko SG280P (all available from Futamura Chemical Co., Ltd.). corporate nature), etc. Among them, Shirasagi ANOX-2 is preferable in terms of more excellent metal removal efficiency.

The amount of the activated carbon used is preferably 1 to 1000 parts by mass, more preferably 5 to 100 parts by mass, and even more preferably 10 to 50 parts by mass with respect to 100 parts by mass of the polymer. .

For example, in the method of removing the heavy metal catalyst in the polymer composition by adding the activated carbon to the polymer composition containing the polymer P, the heavy metal catalyst, and preferably a solvent and stirring, The stirring time is preferably 0.01 to 100 hours, more preferably 0.1 to 50 hours, even more preferably 1 to 60 hours.
The stirring temperature is preferably 0 to 200.degree. C., more preferably 10 to 100.degree. C., even more preferably 20 to 80.degree.
The stirring method is not particularly limited, and includes a method using a known stirrer such as a stirrer and a mixer.

After step (2) of removing the heavy metal catalyst in the polymer composition, the amount of heavy metal in the resulting polymer is preferably 100 ppm or less relative to the polymer. The amount of heavy metals is the amount of heavy metals derived from the heavy metal catalyst used in step (1). When the amount of heavy metal is within the above range, a sulfur-containing polymer having even better light transmittance can be obtained. The heavy metal content is more preferably 10 ppm or less, still more preferably 5 ppm or less, and even more preferably 1 ppm or less relative to the polymer (solid content).
The lower limit of the amount of heavy metals is not particularly limited. 0.001 ppm or more is preferable, and 0.01 ppm or more is more preferable.

The above heavy metal content can be measured using a high frequency inductively coupled plasma emission spectrometry (ICP emission spectrometry) device, and specifically can be determined by the following method. That is, using an ICP emission spectrometer ICP-8100 (manufactured by Shimadzu Corporation), appropriate plasma conditions (for example, high frequency output 1.4 kW, coolant gas 20.0 L / min, plasma gas 1.40 L / min, carrier gas 0 .60 L/min, plasma light source), and the amount of metal in the polymer is evaluated based on the calibration curve. A measurement sample is prepared by appropriately diluting it with a solvent so that the concentration of the polymer is 0.1 to 10% by mass. Examples of the solvent to be used include solvents in which polymers are dissolved, such as N-methylpyrrolidone, dimethylformamide, chlorobenzene, chloroform, and cyclomethylpentyl ether. The measurement sample may be heated, sonicated, and filtered as required.

Moreover, in step (2), it is preferable to further perform a purification step such as reprecipitation after removing the heavy metal catalyst using the activated carbon. The heavy metal catalyst can be further removed by performing the purification step. The method of reprecipitation is not particularly limited, but for example, the polymer composition after the treatment with activated carbon is dropped into methanol acidified with hydrochloric acid to precipitate the polymer, which is then filtered to obtain a precipitate. and washing the precipitate with water or a lower alcohol such as methanol.

<Step (3)>
The production method of the present invention may further comprise step (3) of oxidizing the polymer obtained in step (2). By oxidizing the polymer, the sulfur atoms (-S-) in the main chain of the sulfur-containing polymer are oxidized to form "-SO-" and "-SO ₂ -", and the above-mentioned structural units are formed. It can be a sulfur-containing polymer containing (B) or the structural unit (C). By having the structural units (B) and (C), the polymer can have a higher refractive index and a higher transmittance, as well as excellent resistance to heat-resistant coloring.
The step of oxidizing the polymer may be performed after the step (1) and before the step (2), or may be performed after the step (2). It is preferable to carry out after 2).

Oxidation of the polymer 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, and the like.
Among them, peroxides, or , chloric acid is preferably 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.
In addition, when hydrogen peroxide is used as the peroxide, it is preferable 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. is preferred.
Only one kind of the oxidizing agent may be used, or two or more kinds thereof may be used in combination.

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 at a longer time than the reaction temperature 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 (1) are preferably used.

It is preferable to wash the sulfur-containing polymer obtained by the above-described oxidation step because acid and the like may remain therein. The washing method is not particularly limited, and includes washing with water, an acid, a base, or the like. In addition, in order to remove unreacted substances, the polymer may be passed through a filter or washed with a solvent. Although the solvent is not particularly limited, the same solvent as the reaction solvent can be used.

The method for producing a sulfur-containing polymer may have other steps in addition to the steps (1) to (3) described above. Examples of the above-mentioned other steps include an aging step, a neutralization step, a dilution step, a drying step, a concentration step and a purification step. These steps can be performed by a known method.

2. Sulfur-Containing Polymer The sulfur-containing polymer obtained by the production method of the present invention contains at least one structural unit selected from the group consisting of the above-described structural unit (A), structural unit (B) and structural unit (C). It is preferable that the heavy metal content is 0.0001 ppm or more and 100 ppm or less with respect to the sulfur-containing polymer. The sulfur-containing polymer has a high refractive index and excellent light transmittance. Moreover, it is excellent also in heat-resistant coloring resistance. It has at least one structural unit selected from the group consisting of the structural unit (A), the structural unit (B) and the structural unit (C), and has a heavy metal content of 0.00 relative to the sulfur-containing polymer. A sulfur-containing polymer having a concentration of 0001 ppm or more and 100 ppm or less is also one aspect of the present invention.

As described above, the sulfur-containing polymer of the present invention has an extremely small amount of heavy metals. The amount of heavy metals is more preferably 10 ppm or less, still more preferably 3 ppm or less, and even more preferably 1 ppm or less relative to the polymer (solid content).
In addition, the amount of heavy metals is more preferably 0.001 ppm or more relative to the sulfur-containing polymer (solid content) from the viewpoint that molded products using the sulfur-containing polymer tend to have excellent toughness. It is more preferably 0.01 ppm or more.
The amount of heavy metals 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 -S- in the main chain in the structural unit (A) represented by the general formula (1). Further, in the structural unit (B) represented by the above general formula (2), it means the sulfur atom S of -SO- in the main chain, and in the structural unit (C) represented by the above general formula (3) , means the sulfur atom S of —SO ₂ — in the main chain.
Specifically, the oxygen atom bonded to the sulfur atom S of the main chain is, for example, the oxygen atom O of —SO— in the main chain in the structural unit (B) represented by the general formula (2). In structural unit (C) represented by general formula (3) above, it means 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 0.7 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. The weight average molecular weight is more preferably 1,000 or more, still more preferably 3,000 or more, even more preferably 10,000 or more, from the viewpoint of improving mechanical properties, and 1,000,000 or less from the viewpoint of reducing melt viscosity. is more preferably 100,000 or less.

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 Na D line (589 nm). can be obtained by

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 (v _D ) = (n _D −1)/(n _F −n _C )
In the formula, n _D , n _F , and n _C represent the refractive indices at Fraunhofer's D line (589.3 nm), F line (486.1 nm), and C line (658.3 nm), respectively.

The sulfur-containing polymer preferably has a visible light transmittance of 70% or more. When the visible light transmittance is within the above range, it can be suitably used as an optical material. The visible light transmittance is more preferably 80% or more, still more preferably 85% or more, and even more preferably 88% or more.
The visible light transmittance is the parallel line transmittance, and a spectrophotometer (for example, a UV-visible infrared spectrophotometer V-700 series manufactured by JASCO Corporation) is used using a 1 μm thick thin film made of the sulfur-containing polymer. can be obtained by evaluating the transmittance at a wavelength of 400 nm for air without using an integrating sphere.

3. Sulfur-Containing Polymer Composition The sulfur-containing polymer of the present invention has a high refractive index and excellent light transmittance. Moreover, it is excellent also in heat-resistant coloring resistance. Such a sulfur-containing polymer of the present invention can be combined with other components to form a sulfur-containing polymer composition. The other components are not particularly limited, and can be appropriately selected from known components depending on the purpose and application of the sulfur-containing polymer composition. Among others, the combination of the sulfur-containing polymer with an inorganic substance can significantly improve the transparency. A sulfur-containing polymer composition containing such a sulfur-containing polymer and an inorganic substance is also one aspect of the present invention.
Moreover, the sulfur-containing polymer is preferably obtained by the method for producing a sulfur-containing polymer of the present invention, as described above. Such a sulfur-containing polymer obtained by the method for producing a sulfur-containing polymer and a sulfur-containing polymer composition containing an inorganic substance are also preferred embodiments of the present invention.

The content of the sulfur-containing polymer in the sulfur-containing polymer composition is preferably 1 to 100% by mass relative to 100% by mass of the total solid content of the sulfur-containing polymer composition, and 10 to 50% by mass. and more preferably 30 to 70% by mass.

(inorganic matter)
Examples of the inorganic substances include metals, inorganic oxides, inorganic nitrides, inorganic carbides, inorganic sulfides, inorganic hydroxides, and the like. The above inorganic substances may be used alone or in combination of two or more.
The inorganic substance preferably contains a metal.

Examples of the metals include lithium (Li), sodium (Na), potassium (K), boron (B), magnesium (Mg), calcium (Ca), manganese (Mn), strontium (Sr), barium (Ba ), titanium (Ti), zirconium (Zr), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), aluminum (Al), tin (Sn), silicon (Si ), cesium (Ce), indium (In), and the like.

As the inorganic oxide, a metal oxide containing a metal element is preferable. Examples of the metal oxide include a single metal oxide composed of one metal element, a composite oxide composed of two or more metal elements, and an element different from the single metal oxide or the composite oxide. is a solid solution oxide. The dissimilar element may be a metallic element, or may be a non-metallic element other than oxygen, such as nitrogen or fluorine. Examples of the metal element include the metal elements described above.

Examples of the single metal oxide include magnesium oxide, calcium oxide, strontium oxide, barium oxide, titanium oxide, zinc oxide, cerium oxide, silicon oxide, tin oxide, zirconium oxide, aluminum oxide, and indium oxide. .
Examples of the composite oxide include perovskite-type composite oxides such as barium titanate, barium strontium titanate, strontium titanate, barium zirconium strontium titanate, barium zirconium titanate, and lead zirconate titanate; spinel, lithium titanate, and the like. spinel-type composite oxides; and composite oxides such as aluminum titanate.
Examples of the solid solution oxides include solid solution oxides obtained by dissolving dissimilar metal elements and/or nonmetallic elements other than oxygen, such as nitrogen and fluorine, in the above single metal oxides or composite oxides.

As the inorganic nitride, a metal nitride is preferable, and examples thereof include boron nitride, carbon nitride, and aluminum nitride.
As the inorganic carbide, metal carbide is preferable, and examples thereof include silicon carbide, calcium carbide, titanium carbide, boron carbide, and the like.
As the inorganic sulfides, metal sulfides are preferable, and examples thereof include copper sulfide, zinc sulfide, and cadmium sulfide.
As the inorganic hydroxide, metal hydroxides are preferable, and examples thereof include aluminum hydroxide, magnesium hydroxide, barium hydroxide, and the like.

Among them, the inorganic substance is preferably an inorganic oxide, and more preferably a metal oxide, because it has a wide bandgap (transparent to visible light).
Among the above inorganic substances, Ti, Zr, Ce, Zn, Ti, Zr, Ce, Zn, Oxides containing In, Al, Si, and Sn as main components of metal elements are more preferable, and include titanium oxide (TiO ₂ ), zirconium oxide (ZrO ₂ ), cerium oxide (CeO ₂ ), zinc oxide (ZnO), and indium oxide. (In ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), silicon oxide (SiO ₂ ) and tin oxide (SnO ₂ ) are particularly preferred.

Among the above inorganic substances, zirconium oxide, titanium oxide, and silicon dioxide are more preferred in that they can further improve the transparency of the sulfur-containing polymer composition and that the composition can be made to have a low linear expansion. Zirconium oxide and titanium oxide are more preferred from the viewpoint of improving the refractive index of the sulfur-containing polymer composition. Further, perovskite-type composite oxides are preferable in that they have a high dielectric constant and the sulfur-containing polymer composition can be suitably used as a ferroelectric material and a piezoelectric material. Boron nitride, aluminum hydroxide, and aluminum titanate are preferred from the viewpoint that the sulfur-containing polymer composition can be suitably used as a heat dissipating material because of their high thermal conductivity.

Zinc oxide (ZnO), indium oxide (In ₂ O ₃ ) or tin oxide (SnO ₂ ) is used from the viewpoint of imparting antistatic properties or conductivity while suppressing coloring due to the addition of inorganic substances to the sulfur-containing polymer composition. In addition, a solid solution oxide in which a dissimilar metal element or an additive element such as fluorine is dissolved is preferable. For example, zinc oxide in which In, Al or Ga is dissolved, indium oxide in which Sn or Ti is dissolved, Sb or F. Solid solution tin oxide or the like is more preferable.

The shape of the inorganic substance is not particularly limited, and may be amorphous, granular, plate-like, fibrous, block-like, etc., but granular is preferred.

The inorganic substance may be surface-treated. The surface treatment is not particularly limited as long as it does not affect the effects of the present invention, and includes a method using a silane coupling agent, a method of reacting a compound having a phosphoric acid group, and a compound having a carboxylic acid group. A known method such as a method of reacting can be mentioned.

The average particle size of the inorganic substance is preferably 1 nm or more and 1000 nm or less. When the average particle size of the inorganic substance is within the above range, the light transmittance in the visible light region and the infrared region can be improved. The average particle size of the inorganic substance is more preferably 5 nm or more, still more preferably 10 nm or more, and more preferably 100 nm or less, even more preferably 50 nm or less.
The average particle diameter can be determined by observing the inorganic material with a SEM (magnification of 1000 to 100,000 times, preferably 10,000 times) and analyzing the obtained image, and the number of individual particles (primary particles ), and evaluate the 50% particle size based on the number-based particle size distribution. For image analysis, known image analysis software (eg, Mac-View manufactured by Mountec) can be used.

The content of the inorganic substance is not particularly limited, and can be appropriately set according to the purpose and application of the sulfur-containing polymer composition. For example, the content of the inorganic substance is 10 parts by mass or more with respect to 100 parts by mass of the sulfur-containing polymer in terms of further improving transparency and achieving low linear expansion. It is preferably 30 parts by mass or more, even more preferably 50 parts by mass or more, particularly preferably 70 parts by mass or more, and most preferably 80 parts by mass or more. In addition, from the viewpoint of reducing the melt viscosity when producing a resin molded product, the content of the inorganic substance is preferably 90 parts by mass or less, and 80 parts by mass or less with respect to 100 parts by mass of the sulfur-containing polymer. more preferably 70 parts by mass or less, and even more preferably 50 parts by mass or less.

In addition to the sulfur-containing polymer and inorganic substance described above, the sulfur-containing polymer composition includes, for example, pigments, dyes, antioxidants, ultraviolet absorbers, resins, reactive diluents, light stabilizers, plasticizers, non- Reactive compounds, chain transfer agents, thermal polymerization initiators, anaerobic polymerization initiators, polymerization inhibitors, inorganic fillers, organic fillers, adhesion improvers such as coupling agents, heat stabilizers, antibacterial and antifungal agents, Flame retardant, matting agent, antifoaming agent, leveling agent, wetting/dispersing agent, anti-settling agent, thickener/anti-sagging agent, anti-color splitting agent, emulsifier, anti-slip/scratch agent, anti-skinning agent, drying It may contain components such as agents, antifouling agents, antistatic agents, conductive agents (static aids), and solvents. These components may be used alone or in combination of two or more. These components can be appropriately selected from known ones and used. Moreover, the blending amounts of these components can be appropriately set.

When the sulfur-containing polymer composition is used as an optical material, it may contain other components as appropriate depending on the application of the optical material. Specific examples of the other components include ultraviolet absorbers, IR cut agents, reactive diluents, pigments, detergents, antioxidants, light stabilizers, plasticizers, non-reactive compounds, antifoaming agents, and the like. are preferably mentioned.

The sulfur-containing polymer composition 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 can be obtained by the same method as the method for measuring the glass transition temperature of the polymer described above.

The sulfur-containing polymer composition preferably has a refractive index of 1.69 or more. When the refractive index is within the above range, it can be suitably applied as an optical material or the like. The refractive index is more preferably 1.70 or higher, and even more preferably 1.71 or higher.
The refractive index can be obtained by the same method as the method for measuring the refractive index of the polymer described above.

The sulfur-containing polymer composition 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 more preferably 60 or less, and even more preferably 55 or less, from the viewpoint of adjusting the light dispersion.
The Abbe number can be obtained by the same method as the method for measuring the Abbe number of the polymer described above.

The sulfur-containing polymer composition preferably has a visible light transmittance of 70% or more. When the visible light transmittance is within the above range, it can be suitably used as an optical material. The visible light transmittance is more preferably 80% or more, still more preferably 85% or more, and even more preferably 88% or more.
The visible light transmittance is the parallel line transmittance, and can be obtained by the same method as the above-described method for measuring the visible light transmittance of the polymer.

The method for producing the sulfur-containing polymer composition is not particularly limited, and it can be prepared by mixing the sulfur-containing polymer, the inorganic substance, and, if necessary, other components. Examples of the mixing include known means such as bead mills, roll mills, ball mills, jet mills, kneaders and blenders.

3. Uses The sulfur-containing polymer and sulfur-containing polymer composition of the present invention are materials having a high refractive index and excellent optical transparency, and are therefore suitable for applications requiring a high refractive index and high optical transparency. used. In addition, the sulfur-containing polymer and sulfur-containing polymer composition of the present invention are excellent in heat-resistant coloring resistance, and thus are suitably used for applications requiring heat-resistant coloring resistance.

Specific examples of the sulfur-containing polymer and sulfur-containing polymer composition of the present invention include imaging lenses, optical materials (members), mechanical component materials, electrical and electronic component materials, automobile component materials, civil engineering and construction In addition to materials, molding materials, etc., it is used for various purposes such as materials for paints and adhesives. Above all, it is particularly preferably used for optics, and is 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 transmission bonding materials, filters, diffraction gratings, prisms, light guides, watch glass, optical applications such as transparent glass and cover glass for display devices; photosensors, Optodevice applications such as photoswitches, LEDs, light-emitting devices, optical waveguides, multiplexers, demultiplexers, disconnectors, optical splitters, optical fiber adhesives; substrates for display devices such as LCDs, organic ELs, and PDPs; Display device applications such as substrates for filters, substrates for touch panels, display protective films, display backlights, light guide plates, antireflection films, and antifogging films.

Moreover, the sulfur-containing polymer and the sulfur-containing polymer composition of the present invention are preferably thermoplastic. Molding processing is easy as it is thermoplastic, and it is excellent also in productivity.

The sulfur-containing polymer and sulfur-containing polymer composition of the present invention can also be suitably used as a molding material. The molding method is not particularly limited, and generally known methods for processing thermoplastic resins, such as injection molding, extrusion molding, T-die method, and inflation method, can be mentioned. Alternatively, 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.

As described above, a sulfur-containing polymer having a high refractive index and excellent light transmittance can be easily obtained by the method for producing a sulfur-containing polymer of the present invention. Moreover, the obtained sulfur-containing polymer is also excellent in heat-resistant color resistance.
The sulfur-containing polymer and sulfur-containing polymer composition of the present invention can be suitably used for various applications such as 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 %".

In the examples, each evaluation was performed by the following methods.

<Measurement of heavy metal content>
Using an ICP emission spectrometer ICP-8100 (manufactured by Shimadzu Corporation), appropriate plasma conditions (high frequency output 1.4 kW, coolant gas 20.0 L / min, plasma gas 1.40 L / min, carrier gas 0.60 L / min , plasma light source), the heavy metal content (vanadium content) in the polymer was evaluated based on the calibration curve, and the heavy metal content (ppm) relative to the polymer was obtained.
As a measurement sample, a sample diluted appropriately with a solvent was used so that the concentration of the polymer was 0.1 to 10% by mass. As a solvent, N-methylpyrrolidone was used for the polymer whose main chain was not oxidized, and dimethylformamide was used for the polymer whose main chain was oxidized.

<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.
Equipment: Shimazu, CBM-20A
Detector: 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: 0.3ml/min
Calibration curve: Polystyrene Standards
Eluent: chloroform

< ¹ H-NMR, ¹³ C-NMR>
The obtained polymer was subjected to ¹ H-NMR and ¹³ C-NMR measurements under the following conditions.
Apparatus: Nuclear magnetic resonance apparatus (600 MHz) manufactured by Agilent Technologies
Measurement solvent: deuterated 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.

<Element content ratio O/S ratio>
A photoelectron spectrometer manufactured by JEOL (JPS-9010TR, XPS device, light source: Mg, X-ray output: 400 W) was measured using a sample formed by spin-coating 0.25 ml of the polymer solution onto a silicon wafer. The O/S ratio was calculated by measuring the peak intensity derived from the 2p orbital of the sulfur atom and the peak intensity derived from the 1s orbital of the oxygen atom, and calculating the integral ratio thereof. If necessary, the peak intensity derived from the 1s orbital of carbon atoms was also measured, and the O/S ratio was calculated in consideration of the result.
The method of measurement, the position of binding energy, etc. were referred to Handbook of X-ray Photoelectron Spectroscopy (JEOL, March 1991).

<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.

<Transmittance>
The polymer whose main chain was not oxidized was adjusted to a concentration of 5% by mass with chloroform, and the polymer whose main chain was oxidized was adjusted to a concentration of 5% by mass with hexafluoro-2-propanol. A solution was prepared by dissolving a polymer. The resulting solution was spin-coated on a glass substrate (manufactured by Matsunami Glass Industry Co., Ltd., S1111) that hardly absorbs visible light at about 500 rpm for 60 s, dried at 100 ° C. for 10 minutes to form a thin film (thickness 1 μm). The transmittance of the obtained thin film was measured with a spectrophotometer (V-700 series UV-visible-infrared spectrophotometer manufactured by JASCO Corp.). In order to evaluate the visible light transmittance, the transmittance at 400 nm was used for comparison. Air was used as a control sample.

<Transmittance after heating>
The thin film used in the evaluation of the transmittance of the thin film was heated at 260° C. for 10 minutes, and the transmittance of the thin film after heating was measured in the same manner as in <Transmittance of thin film>. When the difference in transmittance before and after heating is small and the visible light transmittance is high, the heat-resistant color resistance is evaluated to be good.

<Refractive index>
30 mg of the polymer was dissolved in 1,1,2,2-tetrachloroethane (1 ml) and passed through a membrane filter with a pore size of 0.2 μm. 0.4 ml of the solution passed through the filter was sampled and drop-cast onto a glass substrate (2 cm x 2 cm) to obtain a film having a thickness of about 50 nm. For the obtained film, the phase difference of polarized light before and after incidence and the reflection deviation angle ratio were measured using a spectroscopic ellipsometer UVISEL manufactured by HORIBA Scientific. The wavelength (450 nm) and the incident angle (75°) of the incident light were set in advance, and the complex refractive index was obtained.

(Example 1)
[Synthesis of Monomer]
Water (98 mL), o-toluenethiol (2-methylbenzenethiol) (18.2 g, 0.147 mol), tetrabutylammonium iodide (54.3 mg, 0.147 mmol) were added to a 500 mL three-necked flask, and , 30% hydrogen peroxide solution (15.2 mL, 0.147 mol) was added dropwise at 1 mL/min, and stirred at 60° C. for 2 hours. After cooling to room temperature, the supernatant (aqueous layer) was removed, an aqueous sodium thiosulfate solution was added, the mixture was stirred at room temperature for 2 hours, and the supernatant (aqueous layer) was removed. The reaction solid was filtered, washed with pure water and methanol in that order, and vacuum-dried to recover bis(2-methylphenyl)disulfide. Yield was 98%. It was confirmed to be bis(2-methylphenyl)disulfide (2,2′-dimethyldiphenyldisulfide) by ¹ H-NMR, ¹³ C-NMR and FAB-MS.

[Synthesis of polymer]
In a 1000 mL three-necked flask, diphenyl disulfide (131.00 g, 0.6 mol), bis(2-methylphenyl) disulfide (29.53 g, 0.12 mol) obtained in the above <Synthesis of Monomers>, vanadyl Acetylacetonate (0.95 g, 0.0036 mol) and 1,1,2,2,-tetrafluoroethanesulfonic acid (3.28 g, 0.018 mol) were added, dehydrated with nitrogen flow for 10 minutes, and then reacted. Oxidative polymerization was performed by stirring the system at 160° C. for 200 hours with air bubbles (20 mL/min). Polymer P was obtained as a black solid.

[Purification with activated carbon (1)]
8.9 g of polymer P is weighed into a 500 ml three-necked flask and dissolved in 79.3 mL of tetrahydrofuran (THF). Activated carbon (“Shirasagi ANOX-2”, manufactured by Osaka Gas Chemicals Co., Ltd., specific surface area 1400 m ² /g, pore volume 1.4 mL/g, pore diameter distribution mesopores 45 vol%, average pore diameter 4 .1 nm) was added to 1.78 g (20 parts by mass with respect to 100 parts by mass of the polymer), stirred at 25 ° C. for 12 hours, filtered under pressure with a 0.45 μm PTFE filter, and dried under reduced pressure. A sulfur-containing polymer (Example 1) was obtained.

(Examples 2-4)
A sulfur-containing polymer was obtained in the same manner as in Example 1, except that the amount of activated carbon used was as shown in Table 1.

(Example 5)
A sulfur-containing polymer was obtained in the same manner as in Example 1, except that the following [purification with activated carbon (2)] was performed instead of [purification with activated carbon (1)].
[Purification with activated carbon (2)]
The stirring time after the addition of activated carbon in Example 1 was changed from 12 hours to 60 hours, and pressure filtration was performed with a 0.45 μm PTFE filter. The filtrate was added dropwise to methanol acidified with 3% hydrochloric acid to precipitate the produced polymer, followed by filtration. and washed with water and methanol to obtain a sulfur-containing polymer.

(Comparative example 1)
The polymer P obtained in [Synthesis of Polymer] in Example 1 was used as the sulfur-containing polymer in Comparative Example 1.

(Comparative example 2)
After synthesizing a polymer in the same manner as in Example 5 except that no activated carbon was added, the produced polymer was precipitated, filtered, and washed with water and methanol to obtain a sulfur-containing polymer.

(Example 6)
[Oxidation reaction of polymer main chain]
In a 300 ml eggplant flask, 6.73 g of the sulfur-containing polymer obtained in Example 5 was added to 60.9 mL of cyclopentyl methyl ether (CPME) and dissolved at 70°C. A solution prepared by adding 68.2 mg of 1,1,1-trifluoroacetone to 6.90 mL of 30% hydrogen peroxide solution was added to the obtained polymer solution, and the mixture was stirred at 60° C. for 18 hours. A mixed solvent of 122 mL of methanol and 122 mL of water was added to the polymer solution after stirring, and the solid matter was filtered, washed with water and methanol, and dried in a vacuum to obtain a sulfur-containing polymer (Example 6). rice field. Yield was 60%.
The structure of the obtained polymer was identified by ¹ H-NMR, IR and XPS. The element content ratio (O/S) of oxygen atoms O to sulfur atoms S was 0.95 (0.95/1). The S—O bond energy has peaks at 165 eV and 163 eV, and the peaks can be separated into 164-168 eV (sulfoxide) and 162-168 eV (sulfide) by peak separation. was 2.

(Comparative Example 3)
Using the polymer of Comparative Example 2, the oxidation reaction of the polymer main chain was carried out in the same manner as in Example 6 to obtain a sulfur-containing polymer.

Regarding the sulfur-containing polymers obtained in the above Examples and Comparative Examples, the amount of heavy metals (vanadium amount: V amount) relative to the polymer was evaluated by the above method. Also, the weight average molecular weight, transmittance, transmittance after heating, and refractive index were evaluated by the above methods. Table 1 shows the results.

From Table 1, it was confirmed that removal of the heavy metal catalyst yielded a sulfur-containing polymer with high transmittance, excellent transparency, and potential for a high refractive index material. It was also confirmed that the heavy metal catalyst can be suitably removed by the activated carbon treatment. Furthermore, it was confirmed that the sulfur-containing polymer thus obtained maintained a high transmittance after heating at 260° C. for 10 minutes, and was also excellent in heat resistance to coloration.

Claims (7)

From a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (C) represented by the following general formula (3) A method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of
The production method includes a step of polymerizing a monomer component using a heavy metal catalyst;
A method for producing a sulfur-containing polymer, comprising a step of removing a heavy metal catalyst in a polymer composition containing the polymer obtained in the polymerization step and a heavy metal catalyst.

(In formulas (1) to (3), X ¹ , X ² and X ³ are the same or different and represent a divalent aromatic hydrocarbon group which may have a substituent.) The structural unit (A) is a structural unit (A-1) represented by the following general formula (1-1),
The structural unit (B) is a structural unit (B-1) represented by the following general formula (2-1),
The method for producing a sulfur-containing polymer according to claim 1, wherein the structural unit (C) is a structural unit (C-1) represented by the following general formula (3-1).

(In formulas (1-1), (2-1) and (3-1), R ¹ , R ² and R ³ are the same or different and have a reactive functional group, a halogen atom or a substituent represents an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent group, a represents the number of R ¹ and is an integer of 0 to 4. b represents the number of R ² represents an integer of 0 to 4.c represents the number of R ³ and is an integer of 0 to 4.) 3. The method for producing a sulfur-containing polymer according to claim 1, wherein the step of removing the heavy metal catalyst in the polymer composition is performed using activated carbon. Production of a sulfur-containing polymer according to any one of claims 1 to 3, characterized in that after the step of removing the heavy metal catalyst in the polymer composition, the amount of heavy metal is 100 ppm or less relative to the polymer. Method. From a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (C) represented by the following general formula (3) A sulfur-containing polymer having at least one structural unit selected from the group consisting of a sulfur-containing polymer having a heavy metal content of 0.0001 ppm or more and 100 ppm or less relative to the sulfur-containing polymer .

(In formulas (1) to (3), X ¹ , X ² and X ³ are the same or different and represent a divalent aromatic hydrocarbon group which may have a substituent.) 6. The sulfur-containing polymer according to claim 5, which is used for optics. A sulfur-containing polymer composition comprising the sulfur-containing polymer according to claim 5 or 6 and an inorganic substance.