Method for producing sulfur-containing polymer, sulfur-containing polymer, and sulfur-containing polymer composition

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

[Technical Field]

[0001] The present invention relates to a method for producing a sulfur-containing polymer, a sulfur-containing polymer, and a sulfur-containing polymer composition. 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. [Background technology]

[0002] Polycarbonates with aromatic rings and polymeric materials with a fluorene skeleton are known as high refractive index materials. Materials with a large Abbe number, i.e., low light dispersion, are required for refractive index adjustment materials that improve the light extraction efficiency of LEDs and lens materials for imaging systems. Materials with high refractive index and low light dispersion, such as those incorporating sulfur or halogen molecules and those containing metal oxide nanoparticles, have been developed.

[0003] As sulfur-containing materials, thermosetting materials have been developed as lens materials for eyeglasses. However, thermosetting materials have the disadvantage of requiring an increased number of steps when molding and processing them, and from the standpoint of productivity, thermoplastic materials have been desired.

[0004] Various thermoplastic materials with high refractive index and small light dispersion have been investigated so far. For example, Patent Document 1 describes a molding material having a polyarylene sulfide skeleton in which two hydrogen atoms on the benzene ring are substituted with methyl groups, which has excellent moldability in a solution state and can be used as an optical component. Furthermore, for example, Patent Document 2 describes a molding material having a polyarylene sulfide skeleton in which one hydrogen atom of the benzene ring is substituted with a methyl group, as a molding material that has excellent moldability in a solution state and can form optical components having a high refractive index exceeding 1.70. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-168790 [Patent Document 2] Japanese Patent Application Publication No. 2017-52834 Summary of the Invention [Problem to be solved by the invention]

[0006] As a method for producing the molding material having the above-mentioned polyarylene sulfide skeleton, a method of oxidatively polymerizing a disulfide compound or a thiol compound using an oxidizing agent or a catalyst such as 2,3-dichloro-5,6-dicyano-parabenzoquinone (DDQ) is known. However, when the above-mentioned oxidizing agent is used for production, although a polymer with good optical properties is obtained, there are problems in that the production cost is high and a large amount of waste is generated.

[0007] In view of the above-mentioned current situation, 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. [Means for solving the problem]

[0008] The present inventors have conducted extensive research into methods for producing sulfur-containing polymers such as polyarylene sulfide polymers, and have found that although polymerization using a heavy metal catalyst such as a vanadium compound or an iron compound can easily produce a polymer with a small amount of the catalyst, the heavy metal catalyst remains in the polymer, reducing the light transmittance of the polymer. The inventors have also found that removing the heavy metal catalyst during the production process of the sulfur-containing polymer can efficiently produce a polymer with a high refractive index and excellent light transmittance. Furthermore, the inventors have found that the sulfur-containing polymer thus obtained also has excellent heat discoloration resistance, leading to the completion of the present invention.

[0009] That is, the present invention provides a method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (C) represented by the following general formula (3), the production method comprising the steps of: polymerizing a monomer component using a heavy metal catalyst; and removing the heavy metal catalyst from a polymer composition containing the polymer obtained in the polymerization step and the heavy metal catalyst.

[0010] [ka]

[0011] (In formulas (1) to (3), X 1 , X 2 and X 3 are the same or different and represent divalent aromatic hydrocarbon groups which may have a substituent.

[0012] Preferably, 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), and the structural unit (C) is a structural unit (C-1) represented by the following general formula (3-1).

[0013] [ka]

[0014] (In formulas (1-1), (2-1) and (3-1), R 1 , R 2 and R 3 are the same or different and represent a reactive functional group, a halogen atom, or an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, each of which may have a substituent. 1 represents the number of R 2 represents the number of R 3 represents the number of digits, and is an integer between 0 and 4.)

[0015] In the method for producing a sulfur-containing polymer, the step of removing the heavy metal catalyst from the polymer composition is preferably carried out using activated carbon.

[0016] In the method for producing a sulfur-containing polymer, after the step of removing the heavy metal catalyst in the polymer composition, the amount of heavy metals is preferably 100 ppm or less relative to the sulfur-containing polymer.

[0017] The present invention also relates to a sulfur-containing polymer having at least one structural unit selected from the group consisting of a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (C) represented by the following general formula (3), wherein the amount of heavy metals in the sulfur-containing polymer is 0.0001 ppm or more and 100 ppm or less.

[0018] [ka]

[0019] (In formulas (1) to (3), X 1 , X 2 and X 3 are the same or different and represent divalent aromatic hydrocarbon groups which may have a substituent.

[0020] The sulfur-containing polymer is preferably for optical use.

[0021] The present invention also relates to a sulfur-containing polymer composition comprising the above-mentioned sulfur-containing polymer and an inorganic substance. [Effects of the Invention]

[0022] 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 also has excellent heat coloration resistance and can be suitably used for optical applications such as imaging lens materials. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be described in detail below. In addition, a combination of two or more of the individual preferred embodiments of the present invention described below is also a preferred embodiment of the present invention.

[0024] 1. Method for producing sulfur-containing polymers The present invention provides a method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (C) represented by the following general formula (3). The production method is characterized by comprising the steps of: polymerizing a monomer component using a heavy metal catalyst; and removing the heavy metal catalyst from a polymer composition containing the polymer obtained in the polymerization step and the heavy metal catalyst.

[0025] [ka]

[0026] (In formulas (1) to (3), X 1 , X 2 and X 3 are the same or different and represent divalent aromatic hydrocarbon groups which may have a substituent.

[0027] The method for producing a sulfur-containing polymer of the present invention can easily produce a sulfur-containing polymer having a high refractive index and excellent light transmittance. It is presumed that the reason why the method for producing a sulfur-containing polymer of the present invention can easily produce a sulfur-containing polymer having a high refractive index and excellent light transmittance is that by removing the heavy metal catalyst, the absorption caused by the heavy metal catalyst can be eliminated and side reactions during heating can be suppressed.

[0028] The production method of the present invention is a method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of structural unit (A) represented by the above general formula (1), structural unit (B) represented by the above general formula (2), and structural unit (C) represented by the above general formula (3). Each structural unit of the sulfur-containing polymer obtained by the production method of the present invention will first be described.

[0029] <Constituent unit (A)> In the structural unit (A) represented by the general formula (1), 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, a phenanthrylene group, etc. Among these, the divalent aromatic hydrocarbon group is preferably a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, or a triphenylene group, and more preferably a phenylene group, in terms of reducing the light dispersion of the polymer.

[0030] 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 an alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent that may have a substituent (also referred to as "substituent B").

[0031] Examples of the reactive functional group include acidic functional groups such as a carboxyl group (-COOH), a phosphate group (-OPO(OH)), a hydroxyl group (-OH), a sulfo group (-SOH), a sulfate group (-OSOH), a phosphonic acid group (-PO(OH)), a phosphinic acid group (-PO(OH)-), and a mercapto group (-SH); basic functional groups such as an amino group, an ammonium group, an imino group, an amide group, an imide group, a maleimide group, and a cyano group; curable functional groups such as a group having a reactive unsaturated bond (for example, a group having a reactive double bond; typical examples include a vinyl group, a (meth)acryloyl group, an allyl group, and a methallyl group) and a group having a reactive ionic bond (for example, a group having a reactive cyclic ether group; typical examples include an epoxy group and an oxetane group); and groups containing these functional groups.

[0032] Examples of the groups containing these functional groups include groups having the above-mentioned acidic functional group, basic functional group, or curable functional group together with a hydrocarbon chain or a bonding group, etc. In other words, in the present invention, the reactive functional group includes not only the above-mentioned acidic functional group, basic functional group, or curable functional group, but also groups containing these functional groups and a bonding chain. Examples of the linking chain include divalent hydrocarbon groups such as alkylene groups and arylene groups, linking groups such as ether, ester, carbonyl, and amide, and combinations of these. For example, when it is said that a carboxyl group is preferred as the reactive functional group, it means that the reactive functional group is preferably a carboxyl group and / or a group containing a carboxyl group.

[0033] Among the above reactive functional groups, for example, from the viewpoint of improving the dispersibility of inorganic particles, acidic functional groups, basic functional groups, or groups containing these functional groups are preferred, and carboxyl groups, phosphate groups, phosphonic acid groups, hydroxyl groups, or groups containing these functional groups are more preferred. From the viewpoint of 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 preferred, and a hydroxyl group or a group containing a hydroxyl group is more preferred. From the viewpoint of improving adhesion to the substrate, a carboxyl group, a phosphoric acid group, a phosphonic acid group, or a group containing these functional groups is preferred, and a phosphoric acid group, a phosphonic acid group, or a group containing these functional groups is more preferred. Examples of substrates for which adhesion can be improved include inorganic substrates such as inorganic particle substrates (coatings), metal oxide particle substrates (coatings), glass substrates, silicone substrates, and copper substrates, and organic substrates such as organic particle substrates (coatings), and polymer film substrates. From the viewpoint of improving heat resistance, mechanical strength, and solvent resistance, a carboxyl group, a hydroxyl group, an amino group, a maleimide group, a curable functional group, or a group containing these functional groups is preferred, and a carboxyl group, a hydroxyl group, an amino group, a maleimide group, a vinyl group, a (meth)acryloyl group, an allyl group, a methallyl group, an epoxy group, an oxetane group, or a group containing these functional groups is more preferred.

[0034] Among these, the reactive functional group is preferably a carboxyl group, a phosphate group, a phosphonic acid group, a hydroxyl group, a curable functional group, or a group containing these functional groups, more preferably a carboxyl group, a phosphate group, a hydroxyl group, a vinyl group, an epoxy group, or a group containing these functional groups, and even more preferably a phosphate group, a hydroxyl group, a vinyl group, or a group containing these functional groups, in that it can impart a higher refractive index as well as excellent physical properties. Furthermore, in terms of being able to improve adhesion to the substrate with a low linear expansion coefficient in addition to a high refractive index, the reactive functional group is preferably a carboxyl group, a phosphate group, or a group containing these functional groups.

[0035] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a bromine atom being preferred.

[0036] Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an s-butyl group, a t-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 2,2-dimethylbutyl group, a 2,3-dimethylbutyl group, a heptyl group, etc. Among these, an alkyl group having 1 to 18 carbon atoms is preferred, an alkyl group having 1 to 6 carbon atoms is more preferred, and a methyl group is even more preferred.

[0037] Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an s-butoxy group, a t-butoxy group, a pentyloxy group, a phenoxy group, a cyclohexyloxy group, a benzyloxy group, etc. Among these, an alkoxy group having 1 to 18 carbon atoms is preferred, an alkoxy group having 1 to 6 carbon atoms is more preferred, and a methoxy group is more preferred.

[0038] Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a triphenyl group. Of these, a phenyl group is preferred. The number of carbon atoms in the aryl group is preferably 6 to 30, more preferably 6 to 18, and even more preferably 6 to 12.

[0039] Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a phenylpentyl group, a phenylhexyl group, a phenyloctyl group, etc. The aralkyl group preferably has 7 to 14 carbon atoms, and more preferably 7 to 9 carbon atoms.

[0040] Examples of the sulfur-containing substituent include a thioalkyl group and a thioaryl group. Of these, a thioalkyl group is preferred. The number of carbon atoms in the sulfur-containing substituent is preferably 1 to 8, more preferably 1 to 6, and even more preferably 1 to 4.

[0041] The alkyl group, alkoxy group, aryl group, aralkyl group, and sulfur-containing substituent may further have a substituent (substituent B). Examples of the substituent (substituent B) include alkyl groups and halogen atoms. Of these, alkyl groups are preferred from the viewpoint of the solubility of the polymer, and halogen atoms are preferred from the viewpoint of the dispersibility of inorganic particles.

[0042] Among these, the substituent (substituent A) that the divalent aromatic hydrocarbon group may have is more preferably the alkyl group having 1 to 18 carbon atoms and the sulfur-containing substituent, more preferably a methyl group and a thioalkyl group, and particularly preferably a methyl group, in terms of being able to further increase the refractive index and Abbe number. Furthermore, in terms of improving the dispersibility of inorganic particles, the substituent that the divalent aromatic hydrocarbon group may have is preferably a hydroxyl group or a sulfur-containing substituent, more preferably a hydroxyl group, a thioalkyl group, or a thioaryl group, and particularly preferably a hydroxyl group.

[0043] The number of substituents A that the divalent aromatic hydrocarbon group may have is not particularly limited, but a smaller number is preferable in that the refractive index of the polymer will be even higher. Specifically, the number is preferably 1 to 6, more preferably 1 to 3, and even more preferably 1.

[0044] 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.

[0045] [ka]

[0046] (In the formula, R 1 are the same or different and represent a reactive functional group, a halogen atom, or an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, each of which may have a substituent. 1 represents the number of digits, and is an integer between 0 and 4.) R 1When there are a plurality of, they may be the same or different.

[0047] R 1 The reactive functional group, halogen atom, or optionally substituted alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent represented by the formula (1) is preferably the same as the substituent that the divalent aromatic hydrocarbon group in the formula (1) may have.

[0048] Among these, the above R 1 As the alkyl group, a methyl group and a thioalkyl group are more preferred, and a methyl group is particularly preferred.

[0049] In the general formula (1-1), a represents a substituent R 1 and is an integer of 0 to 4. a is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1, in that the refractive index becomes even higher.

[0050] <Constituent Unit (B)> In the structural unit (B) represented by the general formula (2), 2 represents a divalent aromatic hydrocarbon group which may have a substituent. X 2 The divalent aromatic hydrocarbon group represented by the formula (I) includes the above-mentioned X 1 Preferred examples of the divalent aromatic hydrocarbon group include groups similar to those represented by the following formula: X 2 The substituent that the divalent aromatic hydrocarbon group represented by the formula (I) may have is, for example, the above-mentioned X 1 Preferred examples of the substituent include the same groups as the substituents that may be possessed by the divalent aromatic hydrocarbon group represented by the following formula: X 2 The divalent aromatic hydrocarbon group represented by X and its substituents are 1 and the substituents thereof may be the same as or different from the divalent aromatic hydrocarbon group represented by the following formula:

[0051] The above structural unit (B) is preferably a structural unit (B-1) represented by the following general formula (2-1), in that it has high polarity due to solubility and the like.

[0052] [ka]

[0053] (In the formula, R 2 are the same or different and represent a reactive functional group, a halogen atom, or an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, each of which may have a substituent. 2 represents the number of digits, and is an integer between 0 and 4.) R 2 When there are a plurality of, they may be the same or different.

[0054] R 2 The reactive functional group, halogen atom, or optionally substituted alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent represented by the formula (I) can be any of the above-mentioned R 1 Examples of the groups include the same groups represented by the following formula: Among these, the above R 2 As the alkyl group, a methyl group and a thioalkyl group are more preferred, and a methyl group is particularly preferred.

[0055] In the general formula (2-1), b is a substituent R 2 and is an integer of 0 to 4. b is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1, in that the refractive index becomes even higher.

[0056] <Constituent Unit (C)> In the structural unit (C) represented by the general formula (3), 3 represents a divalent aromatic hydrocarbon group which may have a substituent. X 3 The divalent aromatic hydrocarbon group represented by the formula (I) includes the above-mentioned X 1Preferred examples of the divalent aromatic hydrocarbon group include groups similar to those represented by the following formula: X 3 The substituent that the divalent aromatic hydrocarbon group represented by the formula (I) may have is, for example, the above-mentioned X 1 Preferred examples of the substituent include the same groups as the substituents that may be possessed by the divalent aromatic hydrocarbon group represented by the following formula: X 3 The divalent aromatic hydrocarbon group represented by X and its substituents are 1 or X 2 and the substituents thereof may be the same as or different from the divalent aromatic hydrocarbon group represented by the following formula:

[0057] The structural unit (C) is preferably a structural unit (C-1) represented by the following general formula (3-1), in view of high transparency.

[0058] [ka]

[0059] (In the formula, R 3 are the same or different and represent a reactive functional group, a halogen atom, or an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, each of which may have a substituent. 3 represents the number of digits, and is an integer between 0 and 4.) R 3 When there are a plurality of, they may be the same or different.

[0060] R 3 The reactive functional group, halogen atom, or optionally substituted alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent represented by the formula (I) can be any of the above-mentioned R 1 Examples of the groups include the same groups represented by the following formula: Among these, the above R 3 As the alkyl group, a methyl group and a thioalkyl group are more preferred, and a methyl group is particularly preferred.

[0061] In the general formula (3-1), c represents a substituent R 3 and is an integer of 0 to 4. c is preferably 1 to 3, more preferably 1 or 2, and even more preferably 1, in that the refractive index becomes even higher.

[0062] The sulfur-containing polymer may be an alternating copolymer of the structural units (A), (B) and (C), a block copolymer or a random copolymer. The sulfur-containing polymer may have one or more of the structural units (A), (B), and (C).

[0063] The sulfur-containing polymer may be in a form containing only one of the structural units (A), (B), and (C), or may be in a form containing two or three structural units. The form and the content ratio thereof can be appropriately selected depending on the purpose and application of the sulfur-containing polymer. For example, the sulfur-containing polymer preferably contains the structural unit (A) above, and more preferably contains this as the main component, in that this can result in a higher refractive index. Furthermore, the sulfur-containing polymer preferably contains the structural unit (B), more preferably as a main component, in that it can achieve both solubility and a high refractive index. Furthermore, the sulfur-containing polymer preferably contains the structural unit (C) above, and more preferably contains this as the main component, in order to achieve both transparency and a high refractive index.

[0064] In view of the above, in the sulfur-containing polymer, the content of the structural unit (A) is preferably 1 to 100 mol %, more preferably 10 to 100 mol %, and even more preferably 50 to 100 mol %, relative to 100 mol % of all structural units in the polymer, from the viewpoint of a high refractive index. In this case, the total content of the structural units (B) and (C) is preferably 0 to 99 mol%, more preferably 0 to 90 mol%, and even more preferably 0 to 50 mol%, relative to 100 mol% of all structural units.

[0065] In the sulfur-containing polymer, the content of the structural unit (B) is preferably 1 to 100 mol %, more preferably 10 to 100 mol %, and even more preferably 50 to 100 mol %, relative to 100 mol % of all structural units of the polymer, from the viewpoint of high polarity resulting from solubility. In this case, the total content of the structural units (A) and (C) is preferably 0 to 99 mol%, more preferably 0 to 90 mol%, and even more preferably 0 to 50 mol%, relative to 100 mol% of all structural units.

[0066] In the sulfur-containing polymer, the content of the structural unit (C) is preferably 1 to 100 mol %, more preferably 10 to 100 mol %, and even more preferably 50 to 100 mol %, relative to 100 mol % of all structural units in the polymer, from the viewpoint of high transparency. In this case, the total content of the structural units (A) and (B) is preferably 0 to 99 mol%, more preferably 0 to 90 mol%, and even more preferably 0 to 50 mol%, relative to 100 mol% of all structural units.

[0067] In the sulfur-containing polymer, the total content of the structural units (A), (B), and (C) is preferably 50 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and particularly preferably 100 mol%, based on 100 mol% of all structural units in the polymer.

[0068] The sulfur-containing polymer may also have a structural unit (D) other than the structural unit (A), structural unit (B), and structural unit (C). Examples of the structural unit (D) include structural units having at least the reactive functional group described above.

[0069] Examples of monomers into which the structural unit (D) can be introduced include monomers having a polymerizable double bond and the reactive functional group described above. Examples of the polymerizable double bond include a vinyl group, a (meth)acryloyl group, an allyl group, and a methallyl group, and among these, a (meth)acryloyl group is preferred. Examples of the monomer having the polymerizable double bond and the reactive functional group include carboxyl group-containing (meth)acrylates such as 2-carboxyethyl (meth)acrylate, 2-carboxypropyl (meth)acrylate, 3-carboxypropyl (meth)acrylate, and 4-carboxybutyl (meth)acrylate; phosphate group-containing (meth)acrylates such as 2-(meth)acryloyloxyethyl acid phosphate; epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate and 3,4-epoxycyclohexylmethyl (meth)acrylate; and vinyl ether group-containing (meth)acrylates such as 2-(2-vinyloxyethoxy)ethyl (meth)acrylate.

[0070] The content of the structural unit (D) is preferably 0 to 80 mol%, more preferably 0 to 50 mol%, even more preferably 0 to 20 mol%, even more preferably 0 to 10 mol%, and particularly preferably 0 to 5 mol%, relative to 100 mol% of all structural units of the polymer.

[0071] The sulfur-containing polymer preferably has the reactive functional group at the end of the main chain and / or at a side chain. By having the reactive functional group at least at the end of the main chain or at a side chain, the sulfur-containing polymer can exhibit not only a high refractive index but also excellent physical properties due to the reactive functional group. The case where the reactive functional group is present in a side chain includes not only the case where the reactive functional group is present in a side chain of the sulfur-containing polymer, but also the case where the substituent in the structural units (A) to (C) represented by the general formulas (1) to (3) is the reactive functional group or a group containing the reactive functional group.

[0072] The production method of the present invention comprises the steps of (1) polymerizing a monomer component using a heavy metal catalyst, and (2) removing the heavy metal catalyst from a polymer composition containing the polymer obtained in the polymerization step and the heavy metal catalyst. Each step will be described below.

[0073] <Process (1)> The production method of the present invention includes a step (1) of polymerizing a monomer component using a heavy metal catalyst. By polymerizing a monomer component using a heavy metal catalyst, the target polymer can be easily produced by adding a small amount of the heavy metal catalyst.

[0074] The heavy metal catalyst is not particularly limited as long as it is a compound containing a heavy metal that can normally be used as a catalyst, and examples thereof include vanadium compounds, zirconium compounds, titanium compounds, cobalt compounds, nickel compounds, manganese compounds, iron compounds, etc. Among these, vanadium compounds and iron compounds are preferred because of their high reactivity, and vanadium compounds are more preferred. The above heavy metal catalysts may be used alone or in combination of two or more.

[0075] The vanadium compound is not particularly limited as long as it functions as an oxidation polymerization catalyst, but among them, an oxovanadium compound having a V=O bond in the molecule is preferred. Examples of the oxovanadium compound include vanadyl acetylacetonate, oxovanadium salen complex, N,N'-bissalicylideneethylenediamine oxovanadium, phthalocyanine oxovanadium, and tetraphenylporphyrin oxovanadium.

[0076] 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 preferred. Examples of the iron chloride compound include ferric chloride (FeCl3) and 5,10,15,20-tetraphenyl-21H,23H-porphine iron(III) chloride. Iron(III) trifluoromethanesulfonate is also preferred.

[0077] The amount of the heavy metal catalyst used is not particularly limited, but is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, relative to 100 parts by mass of the total monomer components, in terms of enhancing reactivity. Also, the amount of the heavy metal catalyst used is preferably 10 parts by mass or less, more preferably 1 part by mass or less, relative to 100 parts by mass of the total monomer components, in terms of suppressing side reactions.

[0078] 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-mentioned structural units (A) to (C). Preferred examples include disulfide compounds and thiol compounds, and more preferred examples include diaryl disulfide compounds represented by the following general formula (4) and thioaryl compounds represented by the following general formula (5).

[0079] [ka]

[0080] (In formulas (4) and (5), A 1 and A 2 are the same or different and represent monovalent aromatic hydrocarbon groups which may have a substituent. A 1 and A 2 The monovalent aromatic hydrocarbon group represented by the formula (1) is 1Examples include a phenyl group, a naphthyl group, an anthryl group, a triphenyl group, a biphenyl group, a phenanthryl group, etc. Among these, a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, or a triphenyl group is preferred, and a phenyl group is more preferred.

[0081] A 1 and A 2 The substituents that the monovalent aromatic hydrocarbon group represented by the formula (1) may have and the number of the substituents are as follows: 1 The substituents are the same as those that may be possessed by the divalent aromatic hydrocarbon group represented by the following formula:

[0082] 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).

[0083] [ka]

[0084] (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 and represent a hydrogen atom, a halogen atom, a reactive functional group, or an alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent, each of which may have a substituent. The halogen atom, reactive functional group, or optionally substituted alkyl group, alkoxy group, aryl group, aralkyl group, or sulfur-containing substituent is each represented by R 1 The groups are the same as the groups represented by the following formula: Furthermore, the substituents that these groups may have include the same as the substituent B described above, but among these, halogen atoms and hydroxyl groups are preferred.

[0085] Specific examples of the diphenyl sulfide compound include 3,3'-dimethyldiphenyl disulfide, 2,2'-dimethyldiphenyl disulfide, 2,2',3,3'-tetramethyldiphenyl disulfide, 2,2',5,5'-tetramethyldiphenyl disulfide, 2,2',6,6'-tetramethyldiphenyl disulfide, 3,3',5,5'-tetramethyldiphenyl disulfide, 2,2',3,3',5,5'-hexamethyldiphenyl disulfide, and 2,2',3,3',6,6'-hexamethyldiphenyl disulfide. 2,2',3,3',5,5',6,6'-Octamethyldiphenyl disulfide, 2,2'-Diethyldiphenyl disulfide, 3,3'-Diethyldiphenyl disulfide, 2,2',6,6'-Tetraethyldiphenyl disulfide, 2,2',3,3'-Tetraethyldiphenyl disulfide, 2,2',5,5'-Tetraethyldiphenyl disulfide, 3,3',5,5'-Tetraethyldiphenyl disulfide, 2,2',3,3',5,5'-Hexaethyldiphenyl disulfide, 2,2',3,3',6,6'-Hexaethyldiphenyl diphenyl disulfide, 2,2',3,3',5,5',6,6'-octaethyldiphenyl disulfide, 2,2'-dipropyldiphenyl disulfide, 3,3'-dipropyldiphenyl disulfide, 2,2',6,6'-tetrapropyldiphenyl disulfide, 2,2',3,3'-tetrapropyldiphenyl disulfide, 2,2',5,5'-tetrapropyldiphenyl disulfide, 3,3',5,5'-tetrapropyldiphenyl disulfide, 2,2',3,3',5,5'-hexapropyldiphenyl disulfide, 2,2',3,3 ',6,6'-Hexapropyldiphenyl disulfide, 2,2',3,3',5,5',6,6'-Octapropyldiphenyl disulfide, 2,2'-Diisopropyldiphenyl disulfide, 3,3'-Diisopropyldiphenyl disulfide, 2,2',6,6'-Tetraisopropyldiphenyl disulfide, 2,2',3,3'-Tetraisopropyldiphenyl disulfide, 2,2',5,5'-Tetraisopropyldiphenyl disulfide, 3,3',5,5'-Tetraisopropyldiphenyl disulfide, 2,2',3,3',5,Examples include 5'-hexaisopropyldiphenyl disulfide, 2,2',3,3',6,6'-hexaisopropyldiphenyl disulfide, and 2,2',3,3',5,5',6,6'-octaisopropyldiphenyl disulfide.

[0086] Specific examples of the thiol compound include 3-methylbenzenethiol, 2-methylbenzenethiol, thiophenol (benzenethiol), 2,3-dimethylbenzenethiol, 2,5-dimethylbenzenethiol, 2,6-dimethylbenzenethiol, and 3,5-dimethylbenzenethiol.

[0087] The disulfide compound can also be prepared by oxidation of a thiol compound. Therefore, in the polymerization step, a thiol compound can also be used as a precursor of the disulfide compound. A disulfide compound can be obtained by oxidatively bonding two molecules of a thiol compound. The method for oxidatively bonding is not particularly limited, and known methods can be used.

[0088] In addition to the heavy metal catalyst, the polymerization may be carried out using a conventional oxidizing agent used in oxidative polymerization, such as a quinone compound, hydrogen peroxide, perbenzoic acid, metachloroperbenzoic acid, lead tetraacetate, thallium acetate, tetracyanoquinodimethane, tetracyanoethylene, cerium(IV) acetylacetonate, or manganese(III) acetylacetonate. Of these, a quinone oxidizing agent is preferred. The oxidizing agents may be used alone or in combination of two or more.

[0089] 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 (bromanil), 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 (orthobromanil), 3,4,5,6-tetrafluorobenzoquinone, etc. Among these, DDQ is preferred because of its high oxidizing power and easy availability. The quinone-based oxidizing agents may be used alone or in combination of two or more.

[0090] 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 the acid is used in combination with the quinone-based oxidizing agent, the oxidizing power of the quinone-based oxidizing agent can be maintained. The acid is not particularly limited, and examples thereof include sulfuric acid, acetic acid, methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, trifluoromethanesulfonic acid, 1,1,2,2-tetrafluoroethanesulfonic acid, trifluoroacetic acid, perfluoropropionic acid, and perfluorobutyric acid. Among these, 1,1,2,2-tetrafluoroethanesulfonic acid is preferred in terms of increasing acidity. The above acids may be used alone or in combination of two or more.

[0091] When the quinone-based oxidizing agent and the acid are used in combination, the amount of the acid added is preferably 10 to 1,000 mol, more preferably 50 to 500 mol, and even more preferably 80 to 120 mol, relative to 100 mol of the total amount of the quinone-based oxidizing agent added.

[0092] The amount of the oxidizing agent added is preferably 0.1 to 3 mol, more preferably 0.8 to 1.5 mol, and even more preferably 0.9 to 1.1 mol, per mol of the monomer component used.

[0093] In the polymerization step, the polymerization temperature is not particularly limited as long as it is a temperature at which oxidative polymerization proceeds. However, in terms of facilitating the oxidative polymerization, the polymerization temperature is preferably 0 to 200°C, more preferably 10°C or higher, and even more preferably 15°C or higher. In terms of being able to suppress side reactions, the polymerization temperature is more preferably 180°C or lower, and even more preferably 150°C or lower.

[0094] 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.

[0095] In the polymerization, a solvent may be used. Preferred examples of the solvent include dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, tetrachloroethylene, 1,1,2,2-tetrachloroethane, nitromethane, nitrobenzene, chlorobenzene, 1,2-dichlorobenzene, 1,3-dichlorobenzene, N-methylpyrrolidone, tetrahydrofuran, ethyl acetate, and cyclopentyl methyl ether. As the solvent, it is preferable to reduce halogen-based solvents containing halogens, particularly chlorine and bromine, such as chloroform and chlorobenzene, which are highly environmentally harmful, and the amount of these solvents used after the step of synthesizing the polymer is preferably 100% by mass or less, more preferably 50% by mass or less, even more preferably 10% by mass or less, and even more preferably 1% by mass or less, based on the polymer.

[0096] In the above polymerization, the monomer components may be added successively during the polymerization reaction. In the polymerization step, the polymerization may be carried out in multiple stages, such as by oxidatively polymerizing the above-mentioned thiol compound to obtain a disulfide compound, and then oxidatively polymerizing the obtained disulfide compound. After the polymerization step, a polymer composition containing at least the heavy metal catalyst and a polymer obtained by polymerizing the monomer components is obtained.

[0097] <Process (2)> The production method of the present invention includes a 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.

[0098] The method for removing the heavy metal catalyst is not particularly limited and may be any known method, such as removing the magnetic heavy metal catalyst by magnetic adsorption, utilizing precipitation of the heavy metal catalyst by oxidation-reduction, or contacting the polymer composition with activated carbon to adsorb the heavy metal catalyst onto the activated carbon and thereby removing the heavy metal catalyst from the polymer composition. Among these, the method using activated carbon is preferred in terms of the efficiency of removing the heavy metal catalyst. Examples of the method using activated carbon include a method in which activated carbon is added to the polymer composition and stirred, and then the activated carbon is removed by filtration or the like, and a method in which the polymer composition is passed through a column packed with activated carbon.

[0099] The activated carbon used in the present invention is not particularly limited, and various known activated carbons can be used, such as coconut shell-based activated carbon, wood-based activated carbon, coal-based activated carbon, chemically activated activated carbon, and gas-activated activated carbon. These may be used alone or in combination of two or more. Among them, coconut shell-based activated carbon, chemically activated activated carbon, and gas-activated activated carbon are preferred, with chemically activated activated carbon being more preferred, in that they have a higher efficiency in removing heavy metal catalysts.

[0100] The specific surface area of the activated carbon is 100 to 10,000 m, which allows for a larger adsorption capacity. 2 / g, and 500 to 8000m 2 / g, and more preferably 700 to 5000m 2 The specific surface area can be determined by a gas adsorption method.

[0101] The pore volume of the activated carbon is preferably 0.01 to 1000 mL / g, more preferably 0.1 to 100 mL / g, and even more preferably 0.3 to 10 mL / g, in order to achieve a larger adsorption capacity. The pore volume can be determined by gas adsorption (pore diameter: 0.1 to 500 nm) or mercury intrusion (pore diameter: 5 to 5000 nm).

[0102] From the viewpoint of removing the heavy metal catalyst, the pore diameter distribution 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, even more preferably 50 vol% or more, and particularly preferably 80 vol% or more. The pore diameter distribution can be determined by gas adsorption (pore diameter 0.1 to 500 nm) or mercury intrusion (pore diameter 5 to 5000 nm).

[0103] From the viewpoint of removing the heavy metal catalyst, the average pore diameter of the activated carbon is preferably 0.1 to 100 nm, more preferably 1 to 80 nm, and even more preferably 2 to 50 nm. The average pore diameter can be determined by gas adsorption method (pore diameter 0.1 to 500 nm) or mercury intrusion method (pore diameter 5 to 5000 nm).

[0104] The shape of the activated carbon is not particularly limited and may be any of fibrous, powdery, granular, etc. From the viewpoint of adsorption area, powdery or granular shapes are preferred, and powdery shape is more preferred.

[0105] Commercially available activated carbon 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, and Shirasagi P (all manufactured by Osaka Gas Chemicals Co., Ltd.), Taiko SA1000, and Taiko SG280P (all manufactured by Futamura Chemical Co., Ltd.). Among these, Shirasagi ANOX-2 is preferred because of its superior metal removal efficiency.

[0106] 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, per 100 parts by mass of the polymer.

[0107] For example, in the case of a method in which the activated carbon is added to a polymer composition containing the polymer P, a heavy metal catalyst, and preferably a solvent, and the mixture is stirred to remove the heavy metal catalyst from the polymer composition, the stirring time is preferably 0.01 to 100 hours, more preferably 0.1 to 50 hours, and even more preferably 1 to 60 hours. The stirring temperature is preferably 0 to 200°C, more preferably 10 to 100°C, and even more preferably 20 to 80°C. The stirring method is not particularly limited, and examples thereof include a method using a known stirrer such as a stirrer or a mixer.

[0108] After step (2) of removing the heavy metal catalyst from the polymer composition, the amount of heavy metals 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 metals is within the above range, a sulfur-containing polymer having even better light transmittance can be obtained. The amount of heavy metals is more preferably 10 ppm or less, even 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 the heavy metal is not particularly limited, but from the viewpoint of reducing the amount of material used to remove the heavy metal catalyst, it is sufficient that the amount is 0.0001 ppm or more relative to the polymer (solid content), preferably 0.001 ppm or more, and more preferably 0.01 ppm or more.

[0109] The amount of heavy metals can be measured using an inductively coupled plasma (ICP) optical emission spectroscopy (ICP) analyzer. Specifically, it can be determined by the following method. Specifically, measurements are performed using an ICP-8100 optical emission spectroscopy analyzer (Shimadzu Corporation) under appropriate plasma conditions (e.g., radio 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 metals in the polymer is evaluated based on a calibration curve. The measurement sample is prepared by diluting it appropriately with a solvent so that the polymer concentration is 0.1 to 10% by mass. Examples of solvents that can be used include solvents that dissolve polymers, such as N-methylpyrrolidone, dimethylformamide, chlorobenzene, chloroform, and cyclomethylpentyl ether. The measurement sample may be heated, ultrasonicated, or filtered, as necessary.

[0110] In step (2), after removing the heavy metal catalyst using the activated carbon, it is preferable to further carry out a purification step such as reprecipitation. By carrying out the purification step, the heavy metal catalyst can be further removed. The reprecipitation method is not particularly limited, but examples include a method in which the polymer composition after the activated carbon treatment is dropped into hydrochloric acid-acidified methanol to precipitate the polymer, which is then filtered to obtain a precipitate, and the obtained precipitate is washed with water or a lower alcohol such as methanol.

[0111] <Process (3)> The production method of the present invention may further include a step (3) of oxidizing the polymer obtained in step (2). By oxidizing the polymer, sulfur atoms (-S-) in the main chain or the like of the sulfur-containing polymer are oxidized to form "-SO-" or "-SO2-", thereby producing a sulfur-containing polymer containing the above-mentioned structural unit (B) or structural unit (C). By containing the above-mentioned structural unit (B) or (C), the polymer can have a higher refractive index and transmittance and excellent heat discoloration resistance. The step of oxidizing the polymer may be carried out after the step (1) and before the step (2), or may be carried out after the step (2), but is preferably carried out after the step (2).

[0112] The above polymer can be oxidized by an oxidation reaction using an oxidizing agent. The oxidizing agent is not particularly limited, and known oxidizing agents can be used, such as quinone compounds, perbenzoic acid, metachloroperbenzoic acid, lead tetraacetate, thallium acetate, tetracyanoquinodimethane, tetracyanoethylene, cerium (IV) acetylacetonate, manganese (III) acetylacetonate, peroxides, and chloric acid. Among these, it is preferable to use peroxide or chloric acid, since it can appropriately oxidize the sulfur atom (sulfide group, -S-) contained in the main chain to form a sulfoxide (sulfinyl group) (-SO-).

[0113] Examples of the peroxide include metachloroperbenzoic acid, hydrogen peroxide, ammonium persulfate, sodium persulfate, peracetic acid, and t-butyl hydroperoxide. Among these, the oxidizing agent is preferably a peroxide, more preferably metachloroperbenzoic acid or hydrogen peroxide, and even more preferably metachloroperbenzoic acid from the viewpoint of suppressing oxidation to sulfonyl (—SO—) by an excess of the oxidizing agent. When hydrogen peroxide is used as the peroxidizing agent, it is preferable to use a phase transfer catalyst such as trifluoroacetone while reducing the amount of water in order to prevent the precipitation of the sulfur-containing polymer. The above oxidizing agents may be used alone or in combination of two or more.

[0114] The amount of the oxidizing agent to be added is not particularly limited as long as the oxidation reaction of sulfur atoms proceeds to obtain the target polymer, but is usually preferably 1 to 1,000 mol, more preferably 10 to 500 mol, and even more preferably 100 to 400 mol, per mol of sulfur atoms in the sulfur-containing polymer.

[0115] The reaction temperature of the oxidation reaction is not particularly limited as long as it is a temperature at which the desired oxidation reaction proceeds, but is preferably 0 to 200°C, more preferably 10°C or higher, and even more preferably 15°C or higher, in terms of facilitating the oxidation reaction, and is more preferably 180°C or lower, and even more preferably 150°C or lower, in terms of suppressing side reactions.

[0116] The reaction time for the oxidation reaction is not particularly limited, but is usually 0.1 to 100 hours, preferably 1 to 80 hours, more preferably 5 to 50 hours, and even more preferably 10 to 24 hours.

[0117] When oxidation is to be carried out to -SO2-, the reaction may be carried out for a longer time than the reaction temperature described above. The amount of oxidizing agent added in this case is not particularly limited as long as the oxidation reaction of the desired sulfur atoms proceeds, but is usually preferably 1.5 to 100 mol, more preferably 2 to 50 mol, and even more preferably 2 to 10 mol, per mol of sulfur atoms in the polymer.

[0118] A solvent may be used in the oxidation reaction, and preferred examples of the solvent to be used include the same solvents as those used in the polymerization step of step (1) above.

[0119] The sulfur-containing polymer obtained by the oxidation step may contain residual acid, so it is preferable to wash it. The washing method is not particularly limited, and examples thereof include washing with water, acid, base, etc. Furthermore, in order to remove unreacted substances, the polymer may be passed through a filter or washed with a solvent. The solvent is not particularly limited, and the same solvent as the reaction solvent may be used.

[0120] The method for producing the sulfur-containing polymer may include other steps in addition to the above-mentioned steps (1) to (3). Examples of the 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 carried out by known methods.

[0121] 2. Sulfur-containing polymer The sulfur-containing polymer obtained by the production method of the present invention preferably 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) described above, and has a heavy metal content of 0.0001 ppm or more and 100 ppm or less relative to the sulfur-containing polymer. The sulfur-containing polymer has a high refractive index and excellent light transmittance. It also has excellent heat discoloration resistance. Such a sulfur-containing polymer having 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 having a heavy metal content of 0.0001 ppm or more and 100 ppm or less relative to the sulfur-containing polymer, also constitutes one aspect of the present invention.

[0122] As described above, the sulfur-containing polymer of the present invention has an extremely low amount of heavy metals. The amount of heavy metals is preferably 10 ppm or less, more preferably 3 ppm or less, and even more preferably 1 ppm or less, based on the polymer (solid content). Furthermore, from the viewpoint that molded articles using the sulfur-containing polymer tend to have excellent toughness, the amount of heavy metals is more preferably 0.001 ppm or more, and even more preferably 0.01 ppm or more, relative to the sulfur-containing polymer (solid content). The amount of heavy metals can be determined by the above-mentioned ICP emission spectroscopic analysis.

[0123] The sulfur-containing polymer preferably has an elemental ratio (O / S) of oxygen atoms O bonded to sulfur atoms S in the main chain to sulfur atoms S in the main chain of 0.1 to 1.5. When the elemental ratio is within the above range, the transparency and refractive index become higher. Specifically, the sulfur atom S in the main chain refers to, for example, the sulfur atom S of -S- in the main chain in the structural unit (A) represented by the general formula (1) above. Also, in the structural unit (B) represented by the general formula (2) above, it refers to the sulfur atom S of -SO- in the main chain, and in the structural unit (C) represented by the general formula (3) above, it refers to the sulfur atom S of -SO2- in the main chain. The oxygen atom bonded to the sulfur atom S in the main chain specifically means, for example, the oxygen atom O of -SO- in the main chain in the structural unit (B) represented by the general formula (2) above, and means the oxygen atom O of -SO2- in the main chain in the structural unit (C) represented by the general formula (3) above.

[0124] The element content ratio (O / S) is preferably 0.3 or more, and more preferably 0.7 or more, in order to further increase transparency, and is preferably 1.3 or less, and even more preferably 1.1 or less, in order to further increase the refractive index. The element content ratios can be determined by evaluating and measuring the peak intensities of the oxygen 1s orbital (O1s), carbon 1s orbital (C1s), and sulfur 2p orbital (S2p) using an X-ray photoelectron spectrometer (XPS).

[0125] The weight-average molecular weight (Mw) of the sulfur-containing polymer is preferably 500 to 10,000,000. When the weight-average molecular weight is in the above range, the polymer can be suitably used as an optical material. From the viewpoint of improving mechanical properties, the weight-average molecular weight is more preferably 1,000 or more, even more preferably 3,000 or more, and even more preferably 10,000 or more, and from the viewpoint of reducing melt viscosity, it is more preferably 1,000,000 or less, and even more preferably 100,000 or less.

[0126] The polydispersity (weight average molecular weight / number average molecular weight) of the sulfur-containing polymer is preferably 1 or more and 10 or less. When the polydispersity is within the above range, molding becomes easy. In terms of further improving moldability, the polydispersity is more preferably 5 or less, and even more preferably 3 or less.

[0127] The weight-average molecular weight and number-average molecular weight can be determined by gel permeation chromatography (GPC), specifically 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.

[0128] The sulfur-containing polymer preferably has a glass transition temperature (Tg) of 80 to 250°C. When the glass transition temperature is in the above range, molding can be easily carried out. From the viewpoint of increasing heat resistance, the glass transition temperature is more preferably 90°C or higher, and even more preferably 100°C or higher, and from the viewpoint of facilitating molding, it is more preferably 200°C or lower. The glass transition temperature can be determined by a method in which a differential scanning calorimeter (DSC) is used to measure the temperature from room temperature to 250°C (at a temperature increase rate of 10°C / min) in a nitrogen gas atmosphere, and the DSC curve is obtained by evaluating the intersection of the baseline and the tangent at the inflection point.

[0129] The sulfur-containing polymer preferably has a refractive index of 1.69 or more. When the refractive index is within the above range, the polymer can be suitably used in a wide variety of applications, such as optical materials (members), machine part materials, electric and electronic part materials, automobile part materials, civil engineering and construction materials, molding materials, as well as paints and adhesive materials. The refractive index is more preferably 1.7 or more, and even more preferably 1.71 or more. The refractive index can be determined by forming a film having a thickness of 50 nm using the polymer as a measurement sample and measuring the film using a spectroscopic ellipsometer UVISEL (manufactured by HORIBA Scientific) with Na D line (589 nm).

[0130] The sulfur-containing polymer preferably has an Abbe number of 10 or more. When the Abbe number is within the above range, light dispersion is small, making it possible to provide an optical material suitable for lenses. The Abbe number is more preferably 15 or more, even more preferably 18 or more, and even more preferably 20 or more. From the viewpoint of adjusting light dispersion, the Abbe number is preferably 60 or less, and more preferably 55 or less. The Abbe number can be calculated by forming a film using the polymer in the same manner as in measuring the refractive index, measuring the refractive index at D line (589.3 nm), F line (486.1 nm), and C line (656.3 nm) using the spectroscopic ellipsometer, and then using the following calculation formula. Abbe number (v D )=(n D -1) / (n F -n C ) In the formula, n D , n F , n C represent the refractive indices at the Fraunhofer D line (589.3 nm), F line (486.1 nm), and C line (658.3 nm), respectively.

[0131] The sulfur-containing polymer preferably has a visible light transmittance of 70% or more. When the visible light transmittance is within the above range, the polymer can be suitably used as an optical material. The visible light transmittance is more preferably 80% or more, even more preferably 85% or more, and even more preferably 88% or more. The visible light transmittance is a parallel ray transmittance, and can be determined by evaluating the transmittance at a wavelength of 400 nm in air using a 1 μm-thick thin film made of the sulfur-containing polymer with a spectrophotometer (for example, a V-700 series ultraviolet-visible-infrared spectrophotometer manufactured by JASCO Corporation) without using an integrating sphere.

[0132] 3. Sulfur-containing polymer composition The sulfur-containing polymer of the present invention has a high refractive index and excellent light transmittance. It also has excellent thermal discoloration 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. In particular, combining the sulfur-containing polymer with an inorganic substance can significantly improve transparency. The sulfur-containing polymer and a sulfur-containing polymer composition containing an inorganic substance also constitute the present invention. The sulfur-containing polymer is preferably obtained by the method for producing a sulfur-containing polymer of the present invention, as described above. The 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.

[0133] The content of the sulfur-containing polymer in the sulfur-containing polymer composition is preferably 1 to 100% by mass, more preferably 10 to 50% by mass, and even more preferably 30 to 70% by mass, relative to 100% by mass of the total solid content of the sulfur-containing polymer composition.

[0134] (inorganic) Examples of the inorganic substance include metals, inorganic oxides, inorganic nitrides, inorganic carbides, inorganic sulfides, inorganic hydroxides, etc. The inorganic substances may be used alone or in combination of two or more. The inorganic substance preferably contains a metal.

[0135] 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), and indium (In).

[0136] The inorganic oxide is preferably a metal oxide containing a metal element. Examples of the metal oxide include a single metal oxide consisting of one metal element, a composite oxide consisting of two or more metal elements, and a solid solution oxide in which a different element is dissolved in the single metal oxide or the composite oxide. The different element may be a metal element or a non-metal element other than oxygen, such as nitrogen or fluorine. Examples of the metal element include the metal elements described above.

[0137] 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 oxides 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-type composite oxides such as spinel and lithium titanate; and composite oxides such as aluminum titanate. The solid solution oxides include those in which different metal elements and / or non-metal elements other than oxygen, such as nitrogen and fluorine, are solid-solved in the single metal oxides or composite oxides.

[0138] The inorganic nitride is preferably a metal nitride, and examples thereof include boron nitride, carbon nitride, and aluminum nitride. The inorganic carbide is preferably a metal carbide, such as silicon carbide, calcium carbide, titanium carbide, or boron carbide. The inorganic sulfide is preferably a metal sulfide, such as copper sulfide, zinc sulfide, or cadmium sulfide. The inorganic hydroxide is preferably a metal hydroxide, such as aluminum hydroxide, magnesium hydroxide, or barium hydroxide.

[0139] Among these, the inorganic material is preferably an inorganic oxide, more preferably a metal oxide, in that it has a wide band gap (is transparent to visible light). Furthermore, among the above inorganic substances, oxides containing Ti, Zr, Ce, Zn, In, Al, Si, and Sn as the main metal element are more preferred because they have no or little absorption in the visible light region and therefore make it easier to obtain a colorless, transparent composition in which coloring due to the inorganic substance is suppressed, and titanium oxide (TiO2), zirconium oxide (ZrO2), cerium oxide (CeO2), zinc oxide (ZnO), indium oxide (In2O3), aluminum oxide (Al2O3), silicon oxide (SiO2), and tin oxide (SnO2) are particularly preferred.

[0140] Among the above inorganic substances, zirconium oxide, titanium oxide, and silicon dioxide are more preferred in terms of further improving the transparency of the sulfur-containing polymer composition and reducing the linear expansion of the composition, and zirconium oxide and titanium oxide are more preferred in terms of improving the refractive index of the sulfur-containing polymer composition. Perovskite-type complex oxides are preferred in terms of having a high dielectric constant and allowing the sulfur-containing polymer composition to be suitably used as a ferroelectric material or a piezoelectric material. Boron nitride, aluminum hydroxide, and aluminum titanate are preferred in terms of having a high thermal conductivity and allowing the sulfur-containing polymer composition to be suitably used as a heat-dissipating material.

[0141] From the viewpoint of imparting antistatic properties or electrical conductivity to the sulfur-containing polymer composition while suppressing coloration due to the addition of inorganic substances, a solid solution oxide in which a different metal element or an additive element such as fluorine is solid-solved in zinc oxide (ZnO), indium oxide (In2O3), or tin oxide (SnO2) is preferred. For example, zinc oxide in which In, Al, or Ga is solid-solved, indium oxide in which Sn or Ti is solid-solved, or tin oxide in which Sb or F is solid-solved are more preferred.

[0142] The shape of the inorganic material is not particularly limited, and may be any of amorphous, granular, plate-like, fibrous, block-like, etc., with granular being preferred.

[0143] 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 examples thereof include known methods such as a method using a silane coupling agent, a method of reacting a compound having a phosphate group, and a method of reacting a compound having a carboxylic acid group.

[0144] 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, 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, and even more preferably 10 nm or more, and more preferably 100 nm or less, and even more preferably 50 nm or less. The average particle size is determined by observing the inorganic material with an SEM (magnification 1,000 to 100,000 times, preferably 10,000 times), analyzing the resulting image to determine the particle diameters (circular area equivalent diameters) of approximately 10 to 1,000 individual particles (primary particles), and evaluating the 50% particle size based on the number-based particle size distribution. For image analysis, known image analysis software (e.g., Mac-View manufactured by Mountech Co., Ltd.) can be used.

[0145] The content of the inorganic substance is not particularly limited and can be appropriately set depending on the purpose and use of the sulfur-containing polymer composition. For example, the content of the inorganic substance is preferably 10 parts by mass or more, more 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, relative to 100 parts by mass of the sulfur-containing polymer, from the viewpoint of further improving transparency and reducing linear expansion. Furthermore, from the viewpoint of reducing melt viscosity during production of a resin molded product, the content of the inorganic substance is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and even more preferably 50 parts by mass or less, relative to 100 parts by mass of the sulfur-containing polymer.

[0146] In addition to the sulfur-containing polymer and inorganic substance described above, the sulfur-containing polymer composition may contain, 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 retardants, matting agents, defoaming agents, leveling agents, wetting and dispersing agents, anti-settling agents, thickeners and anti-sagging agents, color-flux inhibitors, emulsifiers, slip and scratch inhibitors, anti-skinning agents, drying agents, antifouling agents, antistatic agents, conductive agents (electrostatic assistants), and solvents. These components may be used alone or in combination of two or more. These components may be appropriately selected from known components and used. The amounts of these components may be appropriately determined.

[0147] When the sulfur-containing polymer composition is used for 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 an ultraviolet absorber, an IR cutter, a reactive diluent, a pigment, a detergent, an antioxidant, a light stabilizer, a plasticizer, a non-reactive compound, and an antifoaming agent.

[0148] The sulfur-containing polymer composition preferably has a glass transition temperature (Tg) of 80 to 250°C. When the glass transition temperature is in the above range, molding can be easily performed. From the viewpoint of increasing heat resistance, the glass transition temperature is more preferably 90°C or higher, and even more preferably 100°C or higher, and from the viewpoint of easy molding, it is more preferably 200°C or lower. The glass transition temperature can be determined by the same method as the above-mentioned method for measuring the glass transition temperature of a polymer.

[0149] The sulfur-containing polymer composition preferably has a refractive index of 1.69 or more. When the refractive index is in the above range, the composition can be suitably used as an optical material, etc. The refractive index is more preferably 1.70 or more, and even more preferably 1.71 or more. The refractive index can be determined by the same method as the method for measuring the refractive index of the polymer described above.

[0150] The sulfur-containing polymer composition preferably has an Abbe number of 10 or more. When the Abbe number is within the above range, light dispersion is small and the composition can be an optical material suitable for lenses. The Abbe number is more preferably 15 or more, even more preferably 18 or more, and even more preferably 20 or more. From the viewpoint of adjusting light dispersion, the Abbe number is more preferably 60 or less, and even more preferably 55 or less. The Abbe number can be determined by the same method as the above-mentioned method for measuring the Abbe number of a polymer.

[0151] 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, the composition can be suitably used as an optical material. The visible light transmittance is more preferably 80% or more, even more preferably 85% or more, and even more preferably 88% or more. The visible light transmittance is a parallel line transmittance, and can be determined by the same method as the above-mentioned method for measuring the visible light transmittance of a polymer.

[0152] The method for producing the sulfur-containing polymer composition is not particularly limited, and the sulfur-containing polymer composition can be prepared by mixing the sulfur-containing polymer, the inorganic substance, and, if necessary, other components. The mixing can be performed using known means such as a bead mill, a roll mill, a ball mill, a jet mill, a kneader, or a blender.

[0153] 3.Applications The sulfur-containing polymer and the sulfur-containing polymer composition of the present invention are materials having a high refractive index and excellent light transmittance, and therefore are suitable for applications requiring a high refractive index and high light transmittance. In addition, the sulfur-containing polymer and the sulfur-containing polymer composition of the present invention are also excellent in heat discoloration resistance, and therefore are suitable for applications requiring heat discoloration resistance.

[0154] Specifically, the sulfur-containing polymer and the sulfur-containing polymer composition of the present invention are used for various applications such as imaging lenses, optical materials (members), machine part materials, electric and electronic part materials, automobile part materials, civil engineering and construction materials, molding materials, as well as paints and adhesive materials, etc. Among these, they are particularly preferably used for optical purposes, and are suitably used for optical materials, optical device members, display device members, etc. Specific examples of such applications include optical applications such as eyeglass lenses, imaging lenses for cameras such as (digital) cameras, mobile phone cameras, and in-vehicle cameras, light beam focusing lenses, light diffusing lenses, and other lenses; LED encapsulants, optical adhesives, optical transmission bonding materials, filters, diffraction gratings, prisms, light guides, watch glasses, and transparent glass and cover glass for display devices; optical device applications such as photosensors, photoswitches, LEDs, light-emitting elements, optical waveguides, multiplexers, demultiplexers, disconnectors, optical splitters, and optical fiber adhesives; and display device applications such as substrates for display elements such as LCDs, organic ELs, and PDPs, color filter substrates, touch panel substrates, display protective films, display backlights, light guide plates, anti-reflection films, and anti-fogging films.

[0155] The sulfur-containing polymer and the sulfur-containing polymer composition of the present invention are preferably thermoplastic, which facilitates molding and provides excellent productivity.

[0156] The sulfur-containing polymer and sulfur-containing polymer composition of the present invention can also be suitably used as molding materials. The molding method is not particularly limited, and examples thereof include injection molding, extrusion molding, the T-die method, and inflation molding, which are generally known methods for processing thermoplastic resins. Alternatively, the polymer and sulfur-containing polymer composition may be molded into a desired shape by a casting method, coating method, or other method. The shape is not particularly limited, and examples thereof include various known shapes such as lenses, sheets, and films.

[0157] As described above, the method for producing a sulfur-containing polymer of the present invention makes it possible to easily obtain a sulfur-containing polymer having a high refractive index and excellent light transmittance. The obtained sulfur-containing polymer also has excellent heat discoloration resistance. The sulfur-containing polymer and the sulfur-containing polymer composition of the present invention can be suitably used in various applications such as optical applications. [Example]

[0158] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Unless otherwise specified, "parts" means "parts by mass" and "%" means "% by mass."

[0159] In the examples, each evaluation was carried out by the following methods.

[0160] <Measurement of heavy metal content> Using an ICP optical emission spectrometer ICP-8100 (Shimadzu Corporation), measurements were carried out under 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), and the amount of heavy metal (vanadium amount) in the polymer was evaluated based on the calibration curve, and the amount of heavy metal (ppm) relative to the polymer was calculated. The measurement samples were diluted with a solvent to a polymer concentration of 0.1 to 10% by mass, and N-methylpyrrolidone was used as the solvent for polymers with non-oxidized main chains, while dimethylformamide was used for polymers with oxidized main chains.

[0161] <Weight average molecular weight (Mw)> The weight average molecular weight of the polymer was determined by gel permeation chromatography (GPC) under the following conditions. Equipment: SHIMAZU, CBM-20A Detector: Refractive index detector (RI) (SHIMAZU, SPD-20MA), and ultraviolet-visible-infrared spectrophotometer (SHIMAZU, SPD-20MA) Column: TOSOH, TSKgel SuperHM-N Column temperature: 40℃ Flow rate: 0.3ml / min Calibration curve: Polystyrene Standards Eluent: chloroform

[0162] < 1 H-NMR, 13 C-NMR The obtained polymer was subjected to the following conditions: 1 H-NMR, 13 C-NMR measurements were performed. Apparatus: Agilent Technologies nuclear magnetic resonance spectrometer (600MHz) Measurement solvent: deuterated chloroform Sample preparation: Several mg to several tens of mg of the obtained polymer was dissolved in a measurement solvent.

[0163] <ir> The obtained polymer was subjected to IR measurement under the following conditions. Equipment: 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.

[0164] <Element content ratio O / S ratio> A sample was spin-coated from 0.25 ml of the polymer solution onto a silicon wafer to form a film. A JEOL photoelectron spectrometer (JPS-9010TR, XPS device, light source: Mg, X-ray output: 400 W) was used to measure the peak intensity from the sulfur atom 2p orbital and the peak intensity from the oxygen atom 1s orbital, and the O / S ratio was calculated by calculating their integral ratio. If necessary, the peak intensity from the carbon atom 1s orbital was also measured, and the O / S ratio was calculated taking these results into consideration. The measurement method, the position of the binding energy, etc. were based on Handbook of X-ray Photoelectron Spectroscopy (published by JEOL in March 1991).

[0165] <Binding energy> A sample was prepared by spin-coating 0.25 ml of the polymer solution onto a silicon wafer to form a film. Using this sample, the binding energy was measured from the peak position of the 2p3 / 2 orbital of the sulfur atom using a JEOL photoelectron spectrometer (JPS-9010TR, XPS device).

[0166] <Transmittance> For the polymer without main chain oxidation, a solution was prepared by dissolving the polymer in chloroform to a concentration of 5% by mass. For the polymer with main chain oxidation, a solution was prepared by dissolving the polymer in hexafluoro-2-propanol to a concentration of 5% by mass. The resulting solution was spin-coated at approximately 500 rpm for 60 seconds onto a glass substrate (S1111, manufactured by Matsunami Glass Industry Co., Ltd.) that has little absorption in visible light, and then dried at 100°C for 10 minutes to form a thin film (1 μm thick). The transmittance of the resulting thin film was measured using a spectrophotometer (V-700 series UV-Vis-IR spectrophotometer manufactured by JASCO Corporation). To evaluate visible light transmittance, the transmittance at 400 nm was compared. Air was used as a control sample.

[0167] <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> above. If the difference in transmittance before and after heating is small and the visible light transmittance is high, the heat coloration resistance is evaluated as good.

[0168] <Refractive index> 30 mg of the polymer was dissolved in 1 ml of 1,1,2,2-tetrachloroethane and passed through a membrane filter with a pore size of 0.2 μm. 0.4 ml of the filtered solution was drop-cast onto a glass substrate (2 cm x 2 cm) to obtain a film with a thickness of approximately 50 nm. The phase difference and reflection deviation ratio of polarized light before and after incidence were measured for the resulting film using a HORIBA Scientific UVISEL spectroscopic ellipsometer. The complex refractive index was calculated using preset values for the wavelength (450 nm) and angle of incidence (75°) of the incident light. The refractive index at 190-2000 nm was calculated, and the refractive index at a wavelength of 589 nm was also calculated.

[0169] Example 1 [Monomer synthesis] A 500 mL three-neck flask was charged with water (98 mL), o-toluenethiol (2-methylbenzenethiol) (18.2 g, 0.147 mol), and tetrabutylammonium iodide (54.3 mg, 0.147 mmol). 30% aqueous hydrogen peroxide (15.2 mL, 0.147 mol) was added dropwise at 1 mL / min, and the mixture was stirred at 60°C for 2 hours. The mixture was cooled to room temperature, and the supernatant (aqueous layer) was removed. An aqueous sodium thiosulfate solution was then added, and the mixture was stirred at room temperature for 2 hours. The supernatant (aqueous layer) was then removed. The reaction solid was filtered, washed with purified water and then methanol, and vacuum dried to recover bis(2-methylphenyl)disulfide. The yield was 98%. 1 H-NMR, 13 C-NMR and FAB-MS confirmed that the compound was bis(2-methylphenyl) disulfide (2,2'-dimethyldiphenyl disulfide).

[0170] [Polymer synthesis] Vanadyl acetylacetonate (0.95 g, 0.0036 mol) and 1,1,2,2-tetrafluoroethanesulfonic acid (3.28 g, 0.018 mol) were added to diphenyl disulfide (131.00 g, 0.6 mol) and the bis(2-methylphenyl) disulfide (29.53 g, 0.12 mol) obtained in the above <Monomer Synthesis> in a 1000 mL three-neck flask. After dehydration with a nitrogen flow for 10 minutes, the reaction system was stirred at 160°C for 200 hours while bubbling air (20 mL / min) to carry out oxidative polymerization. Polymer P was obtained as a black solid.

[0171] [Purification with activated carbon (1)] 8.9 g of polymer P was weighed into a 500 mL three-neck flask and dissolved in 79.3 mL of tetrahydrofuran (THF). The resulting solution was added with activated carbon (Shirasagi ANOX-2, manufactured by Osaka Gas Chemicals Co., Ltd., specific surface area 1400 m). 2 1.78 g (20 parts by mass relative to 100 parts by mass of the polymer) of a sulfur-containing polymer (1.78 g / g, pore volume 1.4 mL / g, pore diameter distribution mesopore 45 vol%, average pore diameter 4.1 nm) was added, and the mixture was stirred at 25°C for 12 hours, followed by pressure filtration through a 0.45 µm PTFE filter and drying under reduced pressure to obtain a sulfur-containing polymer (Example 1).

[0172] Examples 2 to 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.

[0173] 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 carried out instead of [Purification with activated carbon (1)]. [Purification with activated carbon (2)] The stirring time after adding the activated carbon in Example 1 was changed from 12 hours to 60 hours, and the mixture was pressure filtered through a 0.45 μm PTFE filter. The filtrate was then added dropwise to 3% hydrochloric acid-acidified methanol to precipitate the produced polymer, which was then filtered and washed with water and methanol to obtain a sulfur-containing polymer.

[0174] (Comparative Example 1) The polymer P obtained in [Synthesis of polymer] of Example 1 was used as the sulfur-containing polymer of Comparative Example 1.

[0175] (Comparative Example 2) A polymer was synthesized in the same manner as in Example 5, except that activated carbon was not added, and then the produced polymer was precipitated, filtered, and washed with water and methanol to obtain a sulfur-containing polymer.

[0176] Example 6 [Oxidation reaction of polymer main chain] In a 300 ml recovery 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 of 68.2 mg of 1,1,1-trifluoroacetone in 6.90 mL of 30% aqueous hydrogen peroxide was added to the resulting 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 stirred polymer solution, and the solid matter was filtered, washed with water and methanol, and vacuum dried to obtain a sulfur-containing polymer (Example 6). The yield was 60%. The structure of the resulting polymer is: 1 The compound was identified by H-NMR, IR, and XPS. The elemental ratio of oxygen atoms (O) to sulfur atoms (S) (O / S) was 0.95 (0.95 / 1). The SO bond energy peaks were observed at 165 eV and 163 eV, and peak separation yielded peaks at 164-168 eV (sulfoxide) and 162-168 eV (sulfide). The peak areas of the sulfoxide and sulfide were 43.8 to 2.2.

[0177] (Comparative Example 3) Using the polymer of Comparative Example 2, an oxidation reaction of the polymer main chain was carried out in the same manner as in Example 6 to obtain a sulfur-containing polymer.

[0178] The sulfur-containing polymers obtained in the above examples and comparative examples were evaluated for the amount of heavy metal (vanadium amount: V amount) relative to the polymer by the above method. Furthermore, the weight-average molecular weight, transmittance, transmittance after heating, and refractive index were evaluated by the above method. The results are shown in Table 1.

[0179] [Table 1]

[0180] From Table 1, it was confirmed that removal of the heavy metal catalyst results in a sulfur-containing polymer with high transmittance and excellent transparency, which can be used as a high refractive index material. It was also confirmed that treatment with activated carbon can effectively remove the heavy metal catalyst. Furthermore, it was confirmed that the sulfur-containing polymer thus obtained maintained a high transmittance even after heating at 260°C for 10 minutes, and also had excellent heat-resistant coloration.< / ir>

Claims

1. A method for producing a sulfur-containing polymer having at least one structural unit selected from the group consisting of a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (C) represented by the following general formula (3), The production method includes a step of polymerizing a monomer component using a heavy metal catalyst; a step of removing the heavy metal catalyst from a polymer composition containing the polymer obtained in the polymerization step and the heavy metal catalyst, the step of removing the heavy metal catalyst from the polymer composition includes a step of adsorbing the heavy metal catalyst or a step of precipitating the heavy metal catalyst by oxidation-reduction, The total content of the structural units (A), (B), and (C) is 80 mol% or more relative to 100 mol% of all structural units of the sulfur-containing polymer. A method for producing a sulfur-containing polymer, comprising: 【Chemical 1】 (In formulas (1) to (3), X １ , X ２ and X ３ are the same or different and represent divalent aromatic hydrocarbon groups which may have a substituent. The substituent is a reactive functional group, a halogen atom, an alkyl group which may have a substituent B, or an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent which may have a substituent B'. The reactive functional group is an acidic functional group, a basic functional group, a curable functional group, or a group containing these functional groups. The acidic functional group is a carboxyl group, a phosphate group, a hydroxyl group, a sulfo group, a sulfur group, a phosphonic acid group, a phosphinic acid group, or a mercapto group. The basic functional group is an amino group, an ammonium group, an imino group, an amide group, an imide group, a maleimide group, or a cyano group. The curable functional group is a vinyl group, a (meth)acryloyl group, an allyl group, a methallyl group, an epoxy group, or an oxetane group. The substituent B is a halogen atom, and the substituent B' is an alkyl group or a halogen atom.

2. 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): 【Chemistry 2】 (In formulas (1-1), (2-1) and (3-1), R １ , R ２ and R ３ are the same or different and represent a reactive functional group, a halogen atom, or an alkyl group, an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent, each of which may have a substituent. １ and is an integer of 0 to 4. b represents the number of R ２ and is an integer of 0 to 4. c represents the number of R ３ and is an integer of 0 to 4. The reactive functional group is an acidic functional group, a basic functional group, a curable functional group, or a group containing any of these functional groups, and the acidic functional group is a carboxyl group, a phosphate group, a hydroxyl group, a sulfo group, a sulfur group, a phosphonic acid group, a phosphinic acid group, or a mercapto group, the basic functional group is an amino group, an ammonium group, an imino group, an amide group, an imide group, a maleimide group, or a cyano group, and the curable functional group is a vinyl group, a (meth)acryloyl group, an allyl group, a methallyl group, an epoxy group, or an oxetane group. The substituent that the alkyl group may have is a halogen atom, and the substituent that the alkoxy group, the aryl group, the aralkyl group, or the sulfur-containing substituent may have is an alkyl group or a halogen atom.

3. 3. The method for producing a sulfur-containing polymer according to claim 1, wherein the step of removing the heavy metal catalyst from the polymer composition is carried out using activated carbon.

4. 4. The method for producing a sulfur-containing polymer according to claim 1, wherein the amount of heavy metals in the polymer composition after the step of removing the heavy metal catalyst is 100 ppm or less based on the polymer.

5. A sulfur-containing polymer having at least one structural unit selected from the group consisting of a structural unit (A) represented by the following general formula (1), a structural unit (B) represented by the following general formula (2), and a structural unit (C) represented by the following general formula (3): the total content of the structural units (A), (B), and (C) is 80 mol% or more, based on 100 mol% of all structural units of the sulfur-containing polymer; the amount of heavy metals is 0.0001 ppm or more and 100 ppm or less relative to the sulfur-containing polymer, The sulfur-containing polymer is characterized in that the heavy metal is vanadium or iron. 【Chemistry 3】 (In formulas (1) to (3), X １ , X ２ and X ３ are the same or different and represent divalent aromatic hydrocarbon groups which may have a substituent. The substituent is a reactive functional group, a halogen atom, an alkyl group which may have a substituent B, or an alkoxy group, an aryl group, an aralkyl group, or a sulfur-containing substituent which may have a substituent B'. The reactive functional group is an acidic functional group, a basic functional group, a curable functional group, or a group containing these functional groups. The acidic functional group is a carboxyl group, a phosphate group, a hydroxyl group, a sulfo group, a sulfur group, a phosphonic acid group, a phosphinic acid group, or a mercapto group. The basic functional group is an amino group, an ammonium group, an imino group, an amide group, an imide group, a maleimide group, or a cyano group. The curable functional group is a vinyl group, a (meth)acryloyl group, an allyl group, a methallyl group, an epoxy group, or an oxetane group. The substituent B is a halogen atom, and the substituent B' is an alkyl group or a halogen atom.

6. 6. The sulfur-containing polymer according to claim 5, which is for optical use.

7. A composition comprising the sulfur-containing polymer according to claim 5 or 6 and an inorganic substance, The sulfur-containing polymer composition, wherein the inorganic substance comprises a metal, a metal oxide, a metal nitride, a metal carbide, a metal sulfide, or a metal hydroxide.

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