Polyetheretherketone decomposition method and novel substance using the decomposition product obtained by this decomposition method as a raw material

Abstract

[Problem] The present invention provides: a polyether ether ketone decomposition method which efficiently decomposes a polyether ether ketone; and a novel compound which is synthesized using a starting material that is a decomposition product obtained by this polyether ether ketone decomposition method. [Solution] A polyether ether ketone decomposition method which decomposes a polyether ether ketone according to the present invention comprises a first reaction step in which the polyether ether ketone, a base and at least one of an alkane thiol, an aromatic mercaptan, sodium sulfide and elemental sulfur are reacted in an organic solvent. A polyether ether ketone can be efficiently decomposed by this polyether ether ketone decomposition method.

Description

Technical Field

[0001] The present invention relates to a method for decomposing polyetheretherketone and a novel substance using the decomposition product obtained by this decomposition method as a raw material.

Background Art

[0002] Polyetheretherketone ((OC6H4OC6H4COC6H4) n ) is a thermoplastic resin that not only has excellent heat resistance, high-temperature properties, chemical resistance, and electrical insulation, but also has ideal properties such as high mechanical strength, dimensional stability, incombustibility, and low smoke generation. Due to such characteristics, it has a wide range of applications in semiconductor-related fields such as retainer rings, wafer chucks, and transport containers, advanced space fields that contribute to weight reduction, fuel efficiency, and maintenance improvement, automotive fields such as actuators, gears, and bearings, general industrial fields such as energy production, compressors and pumps for the chemical industry, and food processing equipment parts. Currently, the production volume is as low as about 100,000 tons globally as of 2018, but it is predicted to grow at an average annual growth rate of 4.54% from 2020 to 2026, and it will be an indispensable material in the industrial society in the future.

[0003] However, due to its high stability, waste treatment and recycling are extremely difficult. Since it has a molecular structure containing many benzene rings, it is also difficult to be decomposed by microorganisms.

[0004] Therefore, the environmental impact is high, and it contains major problems in the future. In fact, there are only a few examples targeting PPS and polyethersulfone (PESU) (Patent Document 1; Non-Patent Documents 1, 2, 3, 4, and 5). Continuing like this will not only cause a high environmental burden, but also cannot cope with the future when non-recyclable plastics are prohibited from use. In addition, since it is an expensive product, even currently, discarding it will result in a large economic loss.

[0005] As a related reaction, the substitution reaction of the methoxy group at the para position of benzophenone, which is one of the structural units of polyphenylene sulfide, with an amino group by an organic superbase catalyst t-Bu-P4 and an arylamine is known (see Non-Patent Document 6), but there is no example in which this method is applied to the depolymerization of polyether ether ketone.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Non-Patent Documents

[0007]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Non-Patent Document 5

Non-Patent Document 6

Summary of the Invention

Problems to be Solved by the Invention

[0008] An object of the present invention is to provide a method for decomposing polyetheretherketone efficiently, and a novel compound synthesized from the decomposition products obtained by the method for decomposing polyetheretherketone, and the like.

Means for Solving the Problems

[0009] As a result of intensive studies to decompose polyetheretherketone, the present inventors have found a method for decomposing polyetheretherketone that efficiently decomposes polyetheretherketone, and have also found that novel compounds and the like can be synthesized from the decomposition products obtained by the method for decomposing polyetheretherketone.

[0010] In particular, it has been found that by reacting polyetheretherketone with 2-phenylethylthiol in the presence of sodium tert-butoxide, polyetheretherketone can be efficiently decomposed, and disodium benzophenone-4,4'-dithiolate and hydroquinone can be efficiently produced.

[0011] Furthermore, it has been found that when an alkyl halide or acid halide is added to the decomposition products obtained by this method for decomposing polyetheretherketone, it reacts only with disodium benzophenone-4,4'-dithiolate, and it has been found that the corresponding sulfur-functionalized benzophenone can be converted while leaving hydroquinone.

[0012] A first aspect of the present invention is a method for decomposing polyetheretherketone, which comprises a first reaction step of reacting polyetheretherketone with a base and at least one of an alkanethiol, an aromatic mercaptan, sodium sulfide, and elemental sulfur in an organic solvent. Here, "elemental sulfur" refers to octasulfur (S8).

[0013] According to such a first aspect, polyetheretherketone can be efficiently decomposed into monomers.

[0014] A second aspect of the present invention is the method for decomposing polyetheretherketone according to the first aspect, characterized in that at least one of an alkanethiol, an aromatic mercaptan, sodium sulfide, and elemental sulfur is reacted with polyetheretherketone in an amount of 0.1 to 6 equivalents.

[0015] According to such a second aspect, polyetheretherketone can be decomposed more efficiently.

[0016] A third aspect of the present invention is the method for decomposing polyetheretherketone according to the first aspect, characterized in that the base is reacted with polyetheretherketone in an amount of 2 to 6 equivalents.

[0017] According to such a third aspect, polyetheretherketone can be decomposed more efficiently.

[0018] A fourth aspect of the present invention is the method for decomposing polyetheretherketone according to any one of the first to third aspects, characterized in that the first reaction step is carried out at 100 to 200°C.

[0019] According to such a fourth aspect, polyetheretherketone can be more efficiently decomposed into monomers without destroying the functional groups of the polyetheretherketone main chain.

[0020] The fifth aspect according to the present invention is that the base is sodium hydroxide, potassium hydroxide, potassium carbonate, potassium phosphate, cesium carbonate, sodium tert-butoxide, lithium tert-butoxide, potassium tert-butoxide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, phosphazene base, t-Bu-P4(1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)-phosphoranylideneamino]-2λ 5 ,4λ 5 -catena-di(phosphazene)), t-Oct-P4(1-tert-octyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)-phosphoranylideneamino]-2λ 5 ,4λ 5 -catena-di(phosphazene)), and t-Bu-P2(1-tert-butyl-2,2,4,4,4-pentakis(dimethylamino)-2λ 5 ,4λ 5 -catena-di(phosphazene)), and is at least one selected from the group consisting of, in the polyether ether ketone decomposition method according to the first aspect.

[0021] According to such a fifth aspect, polyether ether ketone can be decomposed more reliably.

[0022] The sixth aspect according to the present invention is that the organic solvent is at least one selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, benzonitrile, 1,4-dioxane, in the polyether ether ketone decomposition method according to the first aspect.

[0023] According to such a sixth aspect, polyether ether ketone can be decomposed more reliably.

[0024] The seventh aspect of the present invention is a method for decomposing polyether ether ketone, characterized by having a second reaction step of reacting at least one of an alkyl halide, an acid halide, and hydrogen chloride with the first reaction product (first decomposition product) obtained by the first reaction step described in the first aspect.

[0025] According to such a seventh aspect, useful compounds can be produced.

[0026] The eighth aspect of the present invention is that the alkyl halide is at least one selected from the group consisting of methyl iodide, 1-bromohexane, benzyl bromide, 2-phenylethyl bromide, 11-bromomethyltricosane, 1-bromo-3,7-dimethyloctane, 1,4-dichlorobenzene, 4-bromo-1-butene, ethyl 3-bromobutanoate, bromomethylcyclopropane, 2-bromoethanol, and 3-bromo-1-propene oxide, and the acid halide is at least one selected from the group consisting of acetyl chloride, benzoyl chloride, and α-ethylhexanoic acid chloride. This is the method for decomposing polyether ether ketone according to the seventh aspect.

[0027] According to such an eighth aspect, benzophenone having a desired structure can be produced from the first decomposition product obtained by the first reaction step.

[0028] The ninth aspect of the present invention is a compound represented by any one of formulas (1) to (11), which is synthesized using the product obtained by the method for decomposing polyether ether ketone according to the first aspect.

[0029]

Chemical formula

[0030] Here, the "product" in this aspect is a concept that includes the first decomposition product but also includes other products.

[0031] According to such a ninth aspect, novel compounds of formulas (1) to (9) and formula (11) and a compound of formula (10) can be produced from polyetheretherketone. These compounds serve as raw materials for functional polymers, functional plastics, etc., and are very useful compounds.

Advantages of the Invention

[0032] According to the present invention, polyetheretherketone can be efficiently decomposed. Further, according to the present invention, sulfur-functionalized benzophenone and / or hydroquinone containing novel compounds can be produced from polyetheretherketone in high yield and with high selectivity. Furthermore, according to the present invention, useful novel substances can be generated (synthesized).

Brief Description of the Drawings

[0033]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0034] Hereinafter, embodiments of the method for decomposing polyetheretherketone according to the present invention will be described. Note that the present invention is not limited to the following embodiments.

[0035] (Embodiment 1) The method for decomposing polyetheretherketone according to this embodiment is

[0036] (a) a first reaction step of reacting the polyetheretherketone (PEEK), a base, an alkanethiol, an aromatic mercaptan, sodium sulfide, and elemental sulfur in an organic solvent;

[0037] (b) A second reaction step of reacting at least one of an alkyl halide, an acid halide, and hydrogen chloride with the first decomposition product obtained in the first reaction step (a) as described above.

[0038] Polyether ether ketone is a compound having a structure in which benzene rings are linked by ketone and ether bonds at the para positions, and can be represented by the following formula (1).

[0039]

Chemical formula

[0040] The shape of the polyether ether ketone is not particularly limited, and it may be in the form of powder, pellet, film, or lump. The molecular weight is not particularly limited either, but the weight average molecular weight is preferably 5,000 to 50,000, more preferably 10,000 to 30,000, and most preferably 20,800. The number average molecular weight is preferably 1,000 to 50,000, more preferably 5,000 to 30,000, and most preferably 9,000 to 11,000.

[0041] As described above, the polyether ether ketone decomposition method according to this embodiment is composed of two reaction steps: the first reaction step (a) and the second reaction step (b).

[0042] Here, the first reaction step (a) is considered to be a chemical reaction as shown in the following chemical reaction formula. That is, first, polyether ether ketone is decomposed into 4,4'-bis(2-phenylethylthio)benzophenone, and then the 4,4'-bis(2-phenylethylthio)benzophenone is further decomposed into disodium benzophenone-4,4'-dithiolate.

[0043]

Chemical formula

[0044] In the first reaction step (a), as the substance (sulfur reactant) to be reacted with polyether ether ketone, sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, potassium phosphate, cesium carbonate, tert-butoxylithium, sodium tert-butoxide, potassium tert-butoxide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide and other bases can be reacted with an alkane thiol, an aromatic mercaptan, sodium sulfide or elemental sulfur that can convert a thiol into a thiolate. It should be easily understood by an ordinary technician in this field that a thiol can be converted into a thiolate using the following compounds and bases.

[0045] Examples of the alkanethiol include ethanethiol, propanethiol, butanethiol, pentanethiol, hexanethiol, heptanethiol, octanethiol, decanethiol, dodecanethiol, tetradecanethiol, pentadecanethiol, octadecanethiol, icosanethiol, docosanethiol, 2-methylbutanethiol, 2-ethylhexanethiol, benzylthiol, p-methylbenzylthiol, o-methylbenzylthiol, α-methylbenzylthiol, phenoxyphenylmethanethiol, (4-chlorophenyl)methanethiol, (4-fluorophenyl)methanethiol, (4-methoxyphenyl)methanethiol, 4-tert-butylphenylmethanethiol, 2-(pyrazin-2-yl)ethane-1-thiol, (1,3-thiazol-4-yl)methanethiol, 2-phenylethylthiol, 2-(3-nitrophenyl)ethane-1-thiol, 2-(2-chlorophenyl)ethane-1-thiol, 1,2-dimercaptoethane, 1,3-propanedithiol, 1,4-decanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,10-decanedithiol, propane-1,2-dithiol, butane-1,2-dithiol, 2-mercaptoethanol, 3-mercaptopropanol, 4-mercaptobutanol, 6-mercaptohexanol, 1,4-disulfanylbutane-2,3-diol, (1-methylcyclobutyl)methanethiol, (oxa-4-yl)methanethiol, (oxola-3-yl)methanethiol, 2-(methoxycarbonyl)ethylthiol, 2-(2,2-sulfanylethoxy)ethane-1-thiol, ethyl 2-sulfanylacetate, 2-[(sulfanylethyl)sulfanyl]ethane-1-thiol, 2-(2,2-difluoroethoxy)ethane-1-thiol, 2-(2-cyclopropylethoxy)ethane-1-thiol, 2,2-dimethoxyethane-1-thiol, 2-[(aminoethyl)amino]ethane-1-thiol, 3-(triethoxysilyl)propane-1-thiol, 3-(trimethoxysilyl)propane-1-thiol, 2,2-Dimethyl-3-sulfanylpropanol, 3-(tert-butoxy)propane-1-thiol, 3-cyclopropylpropane-1-thiol, 3-fluoropropane-1-thiol, 3-methanesulfanylpropane-1-thiol, 4,4,4-trifluorobutane-1-thiol, 2-aminoethane-1-thiol, 2-aminoethane-1-thiol hydrochloride, 2-(2-aminoethoxy)ethane-1-thiol hydrochloride, 2-aminopropane-1-thiol, 2-aminopropane-1-thiol hydrochloride, 3-dimethylaminopropanethiol, bicyclo[3,1,0]hex-6-yl}methanethiol, t-butylthiol, etc. can be mentioned. Examples of aromatic mercaptans include thiophenol, 4-methylbenzenethiol, 4-methoxybenzenethiol, 4-(t-butyl)benzenethiol, etc., and polyetheretherketone can be decomposed to at least di(carbothio)benzophenone.,

[0046] And among these, ethanol thiol, propanethiol, butanethiol, pentanethiol, hexanethiol, heptanethiol, octanethiol, decanethiol, dodecanethiol, tetradecanethiol, pentadecanethiol, octadecanethiol, icosanethiol, docosanethiol, 2-methylbutanethiol, 2-ethylhexanethiol, benzylthiol, p-methylbenzylthiol, o-methylbenzylthiol, α-methylbenzylthiol, phenoxyphenylmethanethiol, (4-chlorophenyl)methanethiol, (4-fluorophenyl)methanethiol, (4-methoxyphenyl)methanethiol, 4-tert-butylphenylmethanethiol, 2-(pyrazin-2-yl)ethane-1-thiol, (1,3-thiazol-4-yl)methanethiol, 2-phenylethylthiol, 2-(3-nitrophenyl)ethane-1-thiol, 2-(2-chlorophenyl)ethane-1-thiol, 1,2-dimercaptoethane, 1,3-propanedithiol, 1,4-decanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,10-decanedithiol, propane-1,2-dithiol, butane-1,2-dithiol, 2-mercaptoethanol, 3-mercaptopropanol, 4-mercaptobutanol, 6-mercaptohexanol, 1,4-disulfanylbutane-2,3-diol, (1-methylcyclobutyl)methanethiol, (oxa-4-yl)methanethiol, (oxola-3-yl)methanethiol, 2-(methoxycarbonyl)ethylthiol, 2-(2,2-sulfanylethoxy)ethane-1-thiol, ethyl 2-sulfanylacetate, 2-[(sulfanylethyl)sulfanyl]ethane-1-thiol, 2-(2,2-difluoroethoxy)ethane-1-thiol, 2-(2-cyclopropylethoxy)ethane-1-thiol, 2,2-dimethoxyethane-1-thiol, 2-[(aminoethyl)amino]ethane-1-thiol, 3-(triethoxysilyl)propane-1-thiol, 3-(trimethoxysilyl)propane-1-thiol, 2,2-Dimethyl-3-sulfanylpropanol, 3-(tert-butoxy)propane-1-thiol, 3-cyclopropylpropane-1-thiol, 3-fluoropropane-1-thiol, 3-methanesulfanylpropane-1-thiol, 4,4,4-trifluorobutane-1-thiol, 2-aminoethane-1-thiol, 2-aminoethane-1-thiol hydrochloride, 2-(2-aminoethoxy)ethane-1-thiol hydrochloride, 2-aminopropane-1-thiol, 2-aminopropane-1-thiol hydrochloride, 3-dimethylaminopropanethiol, bicyclo[3.1.0]hex-6-yl}methanethiol, etc. of S, N When using an alkanethiol consisting of a primary carbon group or a benzyl group that is susceptible to the 2 reaction, or a thiol in which an electron-withdrawing group is present at the β-position such as 2-phenylethylthiol or sulfur can be eliminated by abstraction of β-hydrogen by a base, polyetheretherketone can be decomposed to the first decomposition product.

[0047] In the first reaction step (a), the sulfur chloride reactant is preferably reacted with polyetheretherketone in an amount of 2 to 6 equivalents, and particularly preferably 3.5 to 4.5 equivalents. The amount of the base is not particularly limited. For example, 0.1 to 6 equivalents, more preferably 1 to 4 equivalents, and particularly preferably 2.5 to 3.5 equivalents, based on polyetheretherketone, are preferred.

[0048] The organic solvent that can be used in the first reaction step (a) is not particularly limited as long as it has a boiling point higher than the temperature at which it acts in the first reaction step described below and does not react with the thiolate and can dissolve the thiolate by solvation. Examples of such organic solvents include 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, benzonitrile, 1,4-dioxane, and the like.

[0049] The reaction in the first reaction step (a) can be carried out under an inert gas (e.g., argon gas, nitrogen, etc.) or in an air atmosphere.

[0050] Also, the reaction in the first reaction step (a) can be carried out within the range of room temperature (25) to 200°C, preferably at 100 to 200°C, and more preferably at 140 to 160°C. If the reaction temperature is lower than 25°C, the decomposition reaction does not proceed, and if it exceeds 200°C, benzophenone cannot be obtained as the first decomposition product.

[0051] Furthermore, the reaction in the first reaction step (a) is preferably carried out for 1 to 40 hours, and more preferably for 20 to 24 hours. During the reaction in the first reaction step (a), it is preferable to stir the first reaction product by known means. If the reaction time in the first reaction step (a) is shorter than 1 hour, a sufficient reaction does not occur, and if it exceeds 40 hours, the reaction does not proceed further.

[0052] Also, the first decomposition product obtained after the reaction in the first reaction step (a) is preferably returned to room temperature (20 - 30°C) before being used in the next second reaction step (b).

[0053] In the second reaction step (b), it can react with benzophenone - 4,4'-dithiolate contained in the first decomposition product obtained from the first reaction step (a) without an additive, and react at least one of an alkyl halide, acid halide, and hydrogen chloride capable of forming a carbon - sulfur bond.

[0054] Examples of the alkyl halide that can be used in the second reaction step (b) include methyl iodide, 1 - bromohexane, benzyl bromide, 2 - phenylethyl bromide, 11 - bromomethyltricosane, 1 - bromo - 3,7 - dimethyloctane, 1,4 - dichlorobenzene, 4 - bromo - 1 - butene, ethyl 3 - bromobutanoate, bromomethylcyclopropane, 2 - bromoethanol, 3 - bromo - 1 - propene oxide, etc.

[0055] In addition to the substances described above, the alkyl halides that can be used in the second reaction step (b) of the present invention also include analogs of alkyl halides. Examples of analogs of alkyl halides include oxygen functional groups in which nucleophilic reactions proceed, such as methyl trifluoromethanesulfonate and ethyl trifluoromethanesulfonate (for example, alkanes having a triflate group or a tosylate group). It should be easily understood by an ordinary technician in this field that, in the second reaction step (b) of the present invention, an analog of an alkyl halide reacts in the same manner as the above-described alkyl halide.

[0056] Examples of acid halides that can be used in the second reaction step (b) include acetyl chloride, benzoyl chloride, and α-ethylhexanoic acid chloride. In the second reaction step (b), the alkyl halide is preferably reacted with polyether ether ketone in an amount of 2 to 6 equivalents, more preferably 2 to 4 equivalents, and particularly preferably 2.7 to 3.3 equivalents.

[0057] It should be easily understood by a technician in this field that a similar reaction occurs when hydrogen chloride is used instead of the alkyl halide or the acid halide.

[0058] The reaction of the second reaction step (b) can be carried out in air. The reaction of the second reaction step (b) is preferably carried out at room temperature (25) to 200 °C, more preferably 80 to 100 °C.

[0059] In addition, the reaction of the second reaction step (b) is preferably carried out for 1 to 24 hours, more preferably 1 to 2 hours.

[0060] Furthermore, during the reaction of the second reaction step (b), it is preferable to stir the reaction mixture by known means.

[0061] After the reaction in the second reaction step (b), for the second reaction product obtained, for example, hydrochloric acid and ethyl acetate are added, separated as the organic layer of the second reaction product, and washed with water and a saturated aqueous sodium chloride solution. Thereafter, it is dried over anhydrous sodium sulfate or anhydrous magnesium sulfate, and by distillation under reduced pressure, sulfur-functionalized benzophenone and hydroquinone can be obtained as a crude product.

[0062] Note that the sulfur-functionalized benzophenone obtained by the polyether ether ketone decomposition method according to the present embodiment can be obtained as a desired sulfur-functionalized benzophenone by selecting the alkyl halide or acid halide used in the second reaction step (b).

[0063] Here, examples of the sulfur-functionalized benzophenone obtained by the polyether ether ketone decomposition method according to the present embodiment include compounds represented by the following formula (2).

[0064]

Chemical formula

[0065] (In formula (2), R represents a carbon group having 1 to 20 carbon atoms or a hydrogen atom. Specifically, an alkyl group having 1 to 20 carbon atoms, an alicyclic alkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 5 to 20 carbon atoms, an aralkyl group having 6 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, a carbonylalkyl group having 1 to 20 carbon atoms, a hydroxyalkyl group having 1 to 20 carbon atoms, an aliphatic carbonyl group having 2 to 20 carbon atoms, an aromatic carbonyl group having 2 to 20 carbon atoms, etc. are shown.).

[0066] Examples of the sulfur-functionalized benzophenone obtained by the polyether ether ketone decomposition method according to the present embodiment include, but are not limited to, compounds represented by the following chemical formulas.

[0067]

Chemical formula

[0068] [Chemical formula]

[0069] In addition, these sulfur-functionalized benzophenones can be produced by using, as the alkyl halide, methyl bromide, methyl iodide, 1-chlorohexane, 1-bromohexane, 1-iodohexane, benzyl chloride, benzyl bromide, benzyl iodide, 2-phenylethyl chloride, 2-phenylethyl bromide, 2-phenylethyl iodide, 1-chloro-3,7-dimethyloctane, 1-bromo-3,7-dimethyloctane, 1-iodo-3,7-dimethyloctane, 1,4-dichlorobenzene, ethyl 4-chlorobutyrate, ethyl 4-bromobutyrate, ethyl 4-iodobutyrate, 4-chloro-1-butene, 4-bromo-1-butene, 4-iodo-1-butene, chloromethylcyclopropane, bromomethylcyclopropane, iodomethylcyclopropane, 2-chloroethanol, 2-bromoethanol, 2-iodoethanol, 3-chloro-1-propene oxide, 3-bromo-1-propene oxide; by using, as the acid halide, 2-ethylhexanoyl chloride, methacryloyl chloride; or by using hydrogen chloride or hydrochloric acid in other cases.

[0070] The reactions in the first reaction step (a) and the second reaction step (b) can be carried out even in the coexistence of glass fibers or various polymers. Examples of the polymers include polyethylene, polypropylene, polystyrene, polyamide, etc. In addition, even in a composite form reinforced with fibers such as carbon fiber-reinforced polyether ether ketone and glass fiber-reinforced polyether ether ketone, they can be decomposed by the polyether ether ketone decomposition method according to this embodiment.

[0071] Moreover, according to the polyetheretherketone decomposition method according to this embodiment, in addition to sulfur-functionalized benzophenone, hydroquinone can be produced. In other words, the polyetheretherketone decomposition method according to the present invention is also a method for producing (synthesizing) sulfur-functionalized benzophenone and hydroquinone.

[0072] Next, the polyetheretherketone decomposition method according to this embodiment will be specifically and in detail described with reference to examples, but it is not limited to the following examples.

Examples

[0073] <Example 1> In an argon atmosphere, 28.8 mg (0.10 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, purchased from Sigma-Aldrich, Cat. No. 456640) of powdered polyetheretherketone was sequentially added with a base (the equivalent amount shown in Table 1 was used relative to the polyetheretherketone), 1,3-dimethyl-2-imidazolidinone (DMI, 0.2 mL), a thiol (the equivalent amount shown in Table 1 was used relative to the polyetheretherketone), and a base (the equivalent amount shown in Table 1 was used relative to the polyetheretherketone). Then, the reaction mixture was stirred at 150 °C.

[0074] After 17 to 25 hours, the reaction mixture (the first reaction product) was returned to room temperature (25 °C), methyl iodide (the equivalent amount shown in Table 1 was used relative to the polyetheretherketone) was added, and the mixture was stirred at 100 °C for 1 hour.

[0075] Subsequently, hydrochloric acid (2 M, 1.0 mL) and ethyl acetate were added to the resulting reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. The crude product was measured by gas chromatography after adding 3.7 mg (5.0 μL, 0.024 mmol) of undecane, and also by adding 5.2 mg (5.0 μL, 0.059 mmol) of 1,4-dioxane 1 The yields of comonomer A and the target 4,4'-dimethylthiobenzophenone B were measured by 1 H NMR measurement.

[0076]

Chemical formula

[0077]

Table 1

[0078] As examined in the experiments shown in Table 1, depolymerization (Entries 1-11) was carried out using various alkanethiols such as n-hexanethiol, phenylethylthiol, benzylthiol, 2-(methoxycarbonyl)ethylthiol, 1,2-bismercaptoethane, and sodium tert-butoxide. As a result, when phenylethylthiol was used, depolymerization and subsequent decomposition of comonomer A proceeded efficiently, and 4,4'-dimethylthiobenzophenone B was produced in high yield (Entries 1, 2).

[0079] Here, since sodium tert-butoxide was expected to exhibit a catalytic action, when the experiment was carried out by reducing the equivalent amount of the base with respect to the thiol, it was found that when 3 equivalents of the base were used with respect to polyetheretherketone, 4,4'-dimethylthiobenzophenone B could be obtained in high yield (Entry 12). At this time, even when the base was replaced with easily available sodium hydroxide, there was no change in the yield of 4,4'-dimethylthiobenzophenone B (Entry 14).

[0080] Note that even when the conditions of Entry 2 were carried out in air, it did not affect the yield of B (Entry 2). Therefore, it was found that the polyether ether ketone decomposition method according to this embodiment proceeds without problems even in an air atmosphere. Also, hydroquinone was generated in the reaction mixture obtained in any of the tests of Entries 1 to 15.

[0081] <Example 2> In this example, based on the depolymerization conditions of Entry 12 in Example 1, the solvent was replaced with N,N-dimethylacetamide for depolymerization.

[0082] Under an argon atmosphere, 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, Cat. No. 456640, purchased from Sigma-Aldrich) of powdered polyether ether ketone, 86.5 mg (0.900 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.21 mmol) of phenylethylthiol were sequentially added, and then the resulting reaction mixture was stirred at 150 °C.

[0083] Then, after 20 hours, the reaction mixture was returned to room temperature (25 °C), 128 mg (0.900 mmol) of methyl iodide was added, and the mixture was stirred at 100 °C for 1 hour. 1.0 mL of hydrochloric acid (2 M) and 1.5 mL of ethyl acetate were added to the resulting reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution.

[0084] Next, the organic layer was extracted from the reaction mixture, dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. 75.9 mg (yield 93%) of 4,4'-dimethylthiobenzophenone B was obtained from the crude product by silica gel column chromatography (developing solvent: hexane / ethyl acetate 96:4 → 7:3). The comonomer was in trace amounts. 1 1H NMR (600 MHz, CDCl3) δ 2.54 (s, 6H, SCH3), 7.28 (d, J = 8.0 Hz, 4H, aromatic), 7.71 (d, J = 8.0 Hz, 4H, aromatic). 13 13C NMR (151 MHz, CDCl3) δ 14.9, 124.8, 130.5, 133.7, 145.0, 195.0.

[0085]

Chemical formula

[0086] <Example 3> In this example, depolymerization (decomposition reaction) of pellet-shaped polyetheretherketone was carried out.

[0087] Under an argon atmosphere, to 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, Cat. No. GF83219856, mean particle size 80 micron, purchased from Sigma-Aldrich) of pellet-shaped polyetheretherketone, 86.5 mg (0.900 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.21 mmol) of phenylethylthiol were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0088] Then, after 20 hours, the reaction mixture was returned to room temperature (25 °C), 128 mg (0.900 mmol) of methyl iodide was added, and the mixture was stirred at 100 °C for 1 hour.

[0089] Next, 5.2 mg (5.0 μL, 0.059 mmol) of 1,4-dioxane was added to the resulting reaction mixture, and it was further dissolved in a small amount of deuterated acetone. 1 It was measured by 1H NMR. As a result, it was confirmed that the polyetheretherketone was decomposed to produce 4,4'-dimethylthiobenzophenone B in a yield of 94% and hydroquinone in a yield of 85%.

[0090]

Chemical formula

[0091] Under an argon atmosphere, 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, Cat. No. GF55060231-1EA, thickness 0.025 mm, purchased from Sigma-Aldrich) of a light amber transparent film-like polyetheretherketone was added with 86.5 mg (0.900 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.21 mmol) of phenylethylthiol in sequence, and then the reaction mixture was stirred at 150 °C.

[0092] After 20 hours, the reaction mixture was returned to room temperature (25 °C), 128 mg (0.900 mmol) of methyl iodide was added, and it was stirred at 100 °C for 1 hour.

[0093] Next, 5.2 mg (5.0 μL, 0.059 mmol) of 1,4-dioxane was added to the resulting reaction mixture, and it was further dissolved in a small amount of deuterated acetone. 1 It was measured by 1H NMR. As a result, it was confirmed that the polyetheretherketone was decomposed to produce 4,4'-dimethylthiobenzophenone B in a yield of 93% and hydroquinone in a yield of 85%.

[0094]

Chemical formula

[0095] In Examples 3 and 4, based on the depolymerization conditions shown in Example 2, the depolymerization of pellet-shaped or film-shaped polyetheretherketone was carried out. As a result, 4,4'-dimethylthiobenzophenone was obtained at a yield comparable to that of powdered polyetheretherketone. In addition, hydroquinone, another depolymerization product, was obtained in a high yield. Since no product of the reaction between this hydroquinone and methyl iodide was observed, it was found that methyl iodide reacted selectively with highly nucleophilic disodium benzophenone-4,4'-dithiolate.

[0096] <Example 5> In this example, glass fiber was added to powdered polyetheretherketone for depolymerization.

[0097] In an argon atmosphere, 87.2 mg (0.302 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, purchased from Sigma-Aldrich, Cat. No. 456640) of powdered polyetheretherketone was sequentially added with 34.2 mg (40 wt%) of glass fiber, 86.4 mg (0.899 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.21 mmol) of phenylethylthiol, and then the reaction mixture was stirred at 150 °C.

[0098] After 20 hours, the reaction mixture was returned to room temperature (25 °C), 128 mg (0.900 mmol) of methyl iodide was added, and the mixture was stirred at 100 °C for 1 hour.

[0099] Next, 5.2 mg (5.0 μL, 0.059 mmol) of 1,4-dioxane was added to the obtained reaction mixture, and it was further dissolved in a small amount of deuterated acetone. 1It was measured by ¹H NMR. As a result, it was observed that polyetheretherketone was decomposed to produce 4,4'-dimethylthiobenzophenone B in a yield of 94% and hydroquinone in a yield of 92%.

[0100]

Chemical formula

[0101] In Example 5, based on the depolymerization conditions shown in Example 2, glass fiber was added and depolymerization was carried out. As a result, 4,4'-dimethylthiobenzophenone and hydroquinone were obtained in high yields at a yield comparable to that of pellet-shaped and film-shaped polyetheretherketone. Similarly, for the depolymerization of pellet-shaped polyetheretherketone, instead of glass fiber, polypropylene (pellet-shaped, isotactic, M w ~250,000, Cat. No. 182389, purchased from Sigma-Aldrich), polystyrene (pellet-shaped, degree of polymerization about 2,000, Cat. No. 198-12805, purchased from Fujifilm Wako Pure Chemical Corporation), nylon-6 (pellet-shaped, Cat. No. 181110, purchased from Sigma-Aldrich) were added, and it was confirmed that 4,4'-dimethylthiobenzophenone B and hydroquinone were produced in high yields without problems.

[0102]

Chemical formula

[0103] <Example 6> In this example, depolymerization was carried out using powdery carbon fiber-containing polyetheretherketone.

[0104] In an argon atmosphere, 41.8 mg of powdered 30 wt% carbon fiber-containing polyetheretherketone (0.10 mmol of PEEK, calculated based on the molar weight of the monomer, purchased from Monotaro's TECAPEEK CF30) was sequentially added with 29.0 mg (0.30 mmol) of sodium tert-butoxide, 0.2 mL of N,N-dimethylacetamide (DMAc), and 55.2 mg (0.40 mmol) of phenylethylthiol. Then, the reaction mixture was stirred at 150 °C.

[0105] After 20 hours, the reaction mixture was returned to room temperature (25 °C), and 43.3 mg (0.30 mmol) of methyl iodide was added and stirred at 100 °C for 1 hour.

[0106] Next, 0.5 mL of hydrochloric acid (2 M) and 1.0 mL of ethyl acetate were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. From the crude product, by silica gel column chromatography (developing solvent: hexane / ethyl acetate 95:5 → 55:45), it was confirmed that polyetheretherketone was decomposed and 18.0 mg (yield 65%) of 4,4'-dimethylthiobenzophenone was produced.

[0107]

Chemical formula

[0108] <Example 7> In this example, depolymerization was carried out using powdered glass fiber-containing polyetheretherketone.

[0109] In an argon atmosphere, 41.0 mg of powdered polyetheretherketone containing 30 wt% glass fiber (0.10 mmol of PEEK, calculated based on the molar weight of the monomer, purchased from Monotaro, TECAPEEK CF30) was sequentially added with 28.8 mg (0.30 mmol) of sodium tert-butoxide, 0.2 mL of N,N-dimethylacetamide (DMAc), and 55.2 mg (0.40 mmol) of phenylethylthiol. Then, the reaction mixture was stirred at 150 °C.

[0110] After 20 hours, the reaction mixture was returned to room temperature (25 °C), and 43.3 mg (0.30 mmol) of methyl iodide was added and stirred at 100 °C for 1 hour.

[0111] Next, 0.5 mL of hydrochloric acid (2 M) and 1.0 mL of ethyl acetate were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. It was confirmed by silica gel column chromatography (developing solvent: hexane / ethyl acetate 95:5 → 55:45) that the polyetheretherketone was decomposed and 14.6 mg (yield 53%) of 4,4'-dimethylthiobenzophenone was produced.

[0112] [Chemical formula]

[0113] (Embodiment 2) In Embodiment 1, after the first reaction step, the second reaction step was subsequently carried out, but the present invention is not limited thereto. For example, even if only the first reaction step is carried out, the polyetheretherketone can be decomposed. That is, the first reaction step itself is a method for decomposing polyetheretherketone. Next, examples of the method for decomposing polyetheretherketone according to the present embodiment will be specifically and detailedly described, but the present invention is not limited to the following examples.

[0114] <Example 8> In this example, depolymerization was carried out using tert-butylbenzenethiol as a sulfur reactant.

[0115] Under an argon atmosphere, 28.9 mg (0.10 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, Cat. No. 456640, purchased from Sigma-Aldrich) of powdered polyether ether ketone, 1.9 mg (0.020 mmol) of sodium tert-butoxide, 0.2 mL of N,N-dimethylacetamide (DMAc), and 33.7 mg (0.20 mmol) of tert-butylbenzenethiol were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0116] After 64 hours, the reaction mixture was returned to room temperature (25 °C), 1.0 mL of hydrochloric acid (2 M) and 1.5 mL of ethyl acetate were added, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. From the crude product, 30.8 mg (yield 60%) of 4,4-bis(tert-butylphenylthio)benzophenone and 10.8 mg (yield 24%) of its comonomer (4-((4-(tert-butyl)phenyl)thio)phenyl)(4-(4-hydroxyphenoxy)phenyl)methanone were obtained by silica gel column chromatography (developing solvent hexane / ethyl acetate 96:4 → 7:3). NMR measurement results of 4,4-bis(tert-butylphenylthio)benzophenone: 1 H NMR (600 MHz, CDCl3) δ 1.34 (s, 18H, tBu), 7.19 (AA’BB’, 4H, aromatic), 7.42 - 7.46 (m, 8H, aromatic), 7.64 (AA’BB’, 4H, aromatic). 1313C NMR (151 MHz, CDCl3) δ 31.3, 34.8, 126.7, 126.8, 128.1, 130.6, 134.0, 134.5, 144.9, 152.4, 194.9.

[0117]

Chem.

[0118] In this example, when using a thiol in which a carbon functional group on sulfur is difficult to desorb in the reaction system, such as tert-butylbenzenethiol, for example, an alkanethiol such as tert-butylthiol, or an aromatic mercaptan having an electron-donating group such as a thiophenol and a tert-butyl group, a methyl group, a methoxy group, or a weak electron-withdrawing group such as chlorine or bromine, benzophenone, which is a first decomposition product having a carbon group derived from the thiol, can be obtained.

[0119] At this time, it was discovered that the base completely acts as a catalyst. Actually, based on the depolymerization conditions shown in Example 8, when depolymerizing powdery polyetheretherketone with an aromatic mercaptan and a catalytic amount of sodium tert-butoxide, a novel compound 4,4'-diarylthiobenzophenone and its precursor comonomer were obtained.

[0120] Therefore, in the method for decomposing polyetheretherketone according to the present invention, polyetheretherketone can be decomposed only in the first reaction step.

[0121] <Example 9> In an argon atmosphere, 29.3 mg (0.10 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n~10,300 (purchased from Sigma-Aldrich, Cat. No. 456640), 29.7 mg (0.30 mmol) of sodium tert-butoxide, 0.2 mL of N,N-dimethylacetamide (DMAc), 55.6 mg (0.40 mmol) of 2-phenylethylthiol, and 8.7 mg (0.72 mmol) of mesitylene as an internal standard were sequentially added, and then the reaction mixture was stirred at 100 °C.

[0122] After 4 hours, the reaction mixture was returned to room temperature (25 °C), 10 μL of the reaction mixture was taken out, dissolved in 0.5 mL of deuterated acetone, 1 and analyzed by 1H NMR. As a result, it was confirmed that the polyetheretherketone was decomposed and 4,4'-bis(2-phenylethylthio)benzophenone, the first decomposition product, was produced in a yield of 99% or more. 1 The analysis results by 1H NMR are shown in Figure 1.

[0123]

Chemical formula

[0124] As in this example, even a thiol having a carbon group that is easily eliminated such as phenylethylthiol can give benzophenone, which is the first decomposition product having a carbon group derived from the thiol, by devising the reaction conditions.

[0125] <Example 10> In this example, it was confirmed that disodium benzophenone-4,4'-dithiolate, which is the first decomposition product, was produced by the polyetheretherketone decomposition method according to this embodiment.

[0126] In an argon atmosphere, to 29.2 mg (0.10 mmol, calculated based on the molar weight of the monomer, average Mw ~20,800, average Mn ~10,300, Cat. No. 456640, purchased from Sigma - Aldrich) of powdered polyetheretherketone, 29.7 mg (0.30 mmol) of sodium tert - butoxide, 0.2 mL of N,N - dimethylacetamide (DMAc), and 55.6 mg (0.40 mmol) of 2 - phenylethylthiol were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0127] And after 18 hours, the reaction mixture was returned to room temperature (25 °C), 0.5 mL each of ethyl acetate and heavy water were added, and the reaction mixture was separated into an organic layer and an aqueous layer.

[0128] After that, only the aqueous layer was taken out, 5.0 μL (0.059 mmol) of the internal standard substance 1,4 - dioxane was added, 1 By analyzing with 1H NMR, it was confirmed that disodium benzophenone - 4,4’ - dithiolate, which is the first decomposition product, was obtained. Incidentally, 1 The analysis results by 1H NMR are shown in Figure 2.

[0129] [Chemical formula]

[0130] (Embodiment 3) In the above - described embodiment, an alkane thiol or an aromatic mercaptan was used as the sulfur reactant, but the present invention is not limited thereto. Polyetheretherketone can also be decomposed by using sodium sulfide as the sulfur reactant. Next, examples of the polyetheretherketone decomposition method according to this embodiment will be given and described specifically and in detail, but it is not limited to the following examples.

[0131] <Example 11> In an argon atmosphere, 28.9 mg (0.10 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, purchased from Sigma-Aldrich, Cat. No. 456640) of powdered polyetheretherketone, 15.7 mg (0.20 mmol) of sodium sulfide, and 0.2 mL of 1,3-dimethyl-2-imidazolidinone (DMI) were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0132] After 17 hours, the reaction mixture was returned to room temperature (25 °C) to obtain the first decomposition product. Then, 59.3 mg (0.42 mmol) of methyl iodide was added to this first decomposition product and stirred at 100 °C for 1 hour. 0.5 mL of hydrochloric acid (2 M) and 1 mL of ethyl acetate were added to the resulting reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution.

[0133] Subsequently, after extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure.

[0134] 5.0 μL (0.059 mmol) of the internal standard substance 1,4-dioxane was added to the crude product, 1 and analyzed by 1H NMR. As a result, it was confirmed that the polyetheretherketone was decomposed and 4,4'-dimethylthiobenzophenone was obtained in a yield of 10%.

[0135]

Chemical formula

[0136] (Embodiment 4) The present invention can decompose polyetheretherketone even when using elemental sulfur (S8) as a sulfur reactant. When using elemental sulfur as the sulfur reactant, it is necessary to use an inorganic strong base such as NaOH or sodium tert-butoxide. Next, examples of the polyetheretherketone decomposition method according to this embodiment will be specifically and detailedly described, but it is not limited to the following examples.

[0137] (Example 12) In an argon atmosphere, 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, Cat. No. 456640, purchased from Sigma-Aldrich) of powdered polyetheretherketone, 19.4 mg (0.20 mmol, calculated based on the molar weight per sulfur atom) of elemental sulfur, 115 mg (1.2 mmol) of sodium tert-butoxide, and 0.6 mL of 1,3-dimethyl-2-imidazolidinone (DMI) were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0138] After 17 hours, the reaction mixture was returned to room temperature (25 °C) to obtain the first decomposition product. Thereafter, 171 mg (1.2 mmol) of methyl iodide was added to this first decomposition product and stirred at 100 °C for 1 hour. 2 M hydrochloric acid (1 mL), 2 mL of ethyl acetate, and 5.0 μL (0.024 mmol) of internal standard undecane were added to the obtained reaction mixture, and the reaction mixture was separated into an organic layer and an aqueous layer.

[0139] Next, after extracting the organic layer and analyzing it by gas chromatography, it was confirmed that the polyetheretherketone was decomposed and 4,4'-dimethylthiobenzophenone was obtained in a yield of 1%.

[0140]

Chemical formula

[0141] (Embodiment 5) In the method for decomposing polyetheretherketone according to Embodiment 1, in the method for producing (synthesizing) sulfur-functionalized benzophenone from polyetheretherketone, various organic halides other than methyl iodide can be used.

[0142] As the alkyl halide (R-X), for example, 1-bromohexane, benzyl bromide, 2-phenylethyl bromide, 2-n-decyl-n-tetradecyl bromide, 1-bromo-3,7-dimethyloctane, 1,4-dichlorobenzene, 4-bromo-1-butene, ethyl 3-bromobutanoate, bromomethylcyclopropane, 2-bromoethanol, 3-bromo-1-propene oxide, α-ethylhexanoyl chloride, hydrogen chloride, etc. can be used. Actually, novel compounds shown below can be synthesized from 2-phenylethyl bromide, 2-n-decyl-n-tetradecyl bromide, 1-bromo-3,7-dimethyloctane, 1,4-dichlorobenzene, 4-bromo-1-butene, ethyl 3-bromobutanoate, bromomethylcyclopropane, 3-bromo-1-propene oxide, α-ethylhexanoyl chloride from the first decomposition product obtained by the polyetheretherketone decomposition method.

[0143] <Example 13: Synthesis of 4,4'-bis(2-phenylethylthio)benzophenone> In an argon atmosphere, 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, purchased from Sigma-Aldrich, Cat. No. 456640) of powdered polyetheretherketone was sequentially added with 86.7 mg (0.90 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.2 mmol) of phenylethylthiol, and then the reaction mixture was stirred at 150 °C.

[0144] Then, after 20 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), and 167 mg (0.90 mmol) of phenylethyl bromide was added, followed by stirring at room temperature (25 °C) for 4 hours.

[0145] Subsequently, 1.5 mL of water and 1.5 mL of ethyl acetate were added to the resulting reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. From the crude product, the target 4,4'-bis(2-phenylethylthio)benzophenone was obtained in 106 mg (yield 78%) by silica gel column chromatography (developing solvent: hexane / ethyl acetate 96:4 → 7:3). 1 H NMR (600 MHz, CDCl3) δ 3.00 (t, J = 7.5 Hz, 4H, CH2), 3.27 (t, J = 8.1 Hz, 4H, CH2), 7.23 - 7.27 (m, 6H, aromatic), 7.33 (AA’BB’C, 4H, aromatic), 7.36 (AA’BB’, 4H, aromatic), 7.72 (AA’BB’, 4H, aromatic). 13 C NMR (151 MHz, CDCl3) δ 33.6, 35.2, 126.5, 126.7, 128.6, 128.7, 130.6, 134.3, 139.8, 143.4, 195.0.

[0146]

Chemical Structure

[0147] <Example 14: Synthesis of 4,4'-bis(2-norm-decyl-norm-tetradecylthio)benzophenone> Under an argon atmosphere, 86.9 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M nTo ~10,300 (purchased from Sigma - Aldrich, Cat. No. 456640), 86.7 mg (0.90 mmol) of sodium tert - butoxide, 0.6 mL of N,N - dimethylacetamide (DMAc), and 167 mg (1.2 mmol) of phenylethylthiol were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0148] And after 20 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), 376 mg (0.90 mmol) of 2 - n - decyl - n - tetradecyl bromide was added, and the mixture was stirred at 80 °C for 2 hours.

[0149] Next, 1.5 mL of water, 1.5 mL of hexane, and 1.5 mL of ethylene chloride were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and the crude product was obtained by distillation under reduced pressure. From the crude product, the target 4,4‘ - bis(2 - n - decyl - n - tetradecylthio)benzophenone was obtained in 240 mg (yield 87%) by silica gel column chromatography (developing solvent: hexane / ethyl acetate 100:0 → 7:3) and preparative liquid chromatography (developing solvent: chloroform). 1 H NMR (600 MHz, CDCl3) δ 0.87 (t, J = 6.9 Hz, 12H, methyl), 1.22 - 1.33 (m, 72H, methylene), 1.36 - 1.45 (m, 8H, methylene), 1.66 - 1.71 (m, 2H, methylene), 2.97 (d, J = 6.4 Hz, 4H, SCH2), 7.32 (AA’BB’, 4H, aromatic), 7.69 (AA’BB’, 4H, aromatic). 1313C NMR (151 MHz, CDCl3) δ 14.1, 22.7, 26.6, 29.36, 29.38, 29.62, 29.65, 29.68, 29.69, 29.7, 29.9, 31.93, 31.94, 33.3, 37.0, 37.4, 126.3, 130.4, 134.1, 144.7, 194.9 (Several signals derived from alkyl carbons are overlapping with other signals.).

[0150]

Chem.

[0151] <Example 15: Synthesis of 4,4'-Di(4-chlorobutylthio)benzophenone> Under an argon atmosphere, 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, Cat. No. 456640, purchased from Sigma-Aldrich) of powdered polyether ether ketone was sequentially added with 86.9 mg (0.90 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.2 mmol) of phenylethylthiol, and then the reaction mixture was stirred at 150 °C.

[0152] After 20 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), 383 mg (3.0 mmol) of 1,4-dichlorobutane was added, and the mixture was stirred at 80 °C for 23 hours.

[0153] Subsequently, water and ethylene chloride were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. The target 4,4'-bis(4-chlorobutylthio)benzophenone was obtained in an amount of 85.6 mg (yield 67%) by preparative liquid chromatography (developing solvent: chloroform) from the crude product. 1 H NMR (600 MHz, CDCl3) δ 1.86-1.91 (m, 4H, methylene), 1.93-1.98 (m, 4H, methylene), 3.04 (t, J = 7.1 Hz, 4H, SCH2), 3.57 (d, J = 6.4 Hz, 4H, ClCH2), 7.33 (AA’BB’, 4H, aromatic), 7.71 (AA’BB’, 4H, aromatic). 13 C NMR (151 MHz, CDCl3) δ 26.1, 31.4, 31.5, 44.3, 126.6, 130.5, 134.4, 143.3, 194.8.

[0154]

Chemical formula

[0155] <Example 14: Synthesis of 4,4'-bis(4-butenylthio)benzophenone> Under an argon atmosphere, 86.5 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, purchased from Sigma-Aldrich, Cat. No. 456640) of powdered polyetheretherketone, 86.5 mg (0.90 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.2 mmol) of phenylethylthiol were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0156] And after 20 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), 122 mg (0.9 mmol) of 4-bromo-1-butene was added, and the mixture was stirred at 100 °C for 2 hours.

[0157] Then, water and ethyl acetate were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and the crude product was obtained by distillation under reduced pressure. The target 4,4'-di(4-butenylthio)benzophenone was obtained in 102 mg (yield 97%) by silica gel column chromatography (developing solvent: hexane / ethyl acetate 100:0 → 7:3). 1 H NMR (600 MHz, CDCl3) δ 2.44 - 2.48 (m, 4H, CH2), 3.07 (t, J = 7.6 Hz, 4H, SCH2), 5.09 (dq, J = 1.4, 10.1 Hz, 2H, ethenyl), 5.13 (dq, J = 1.6, 17.1 Hz, 2H, ethenyl), 5.13 (ddt, J = 6.7, 10.4, 17.1 Hz, 2H, ethenyl), 7.33 (AA’BB’C, 4H, aromatic), 7.71 (AA’BB’, 4H, aromatic). 13 C NMR (151 MHz, CDCl3) δ 31.4, 33.0, 116.8, 126.4, 130.6, 134.3, 135.9, 143.5, 195.0.

[0158]

Chemical formula

[0159] <Example 17: Synthesis of 4,4'-di(3-ethoxycarbonylpropylthio)benzophenone> Under an argon atmosphere, 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w~20,800, average M n ~10,300, Cat. No. 456640 (purchased from Sigma-Aldrich), 86.5 mg (0.90 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.2 mmol) of phenylethylthiol were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0160] And after 20 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), 177 mg (0.9 mmol) of ethyl 4-bromobutyrate was added, and the mixture was stirred at 100 °C for 2 hours.

[0161] Subsequently, water and ethyl acetate were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and the crude product was obtained by distillation under reduced pressure. From the crude product, the target 4,4'-bis(3-ethoxycarbonylpropylthio)benzophenone (127 mg, yield 89%) was obtained by silica gel column chromatography (developing solvent: hexane / ethyl acetate 96:4 → 7:3). 1 H NMR (600 MHz, CDCl3) δ 1.26 (t, J = 7.2 Hz, 6H, CH3), 2.03 (quint, J = 7.2 Hz, 4H, CH2), 2.49 (t, J = 7.4 Hz, 4H, CH2), 3.06 (t, J = 7.0 Hz, 4H, SCH2), 4.14 (q, J = 7.2 Hz, 4H, OCH2), 7.35 (AA’BB’, 4H, aromatic), 7.70 (AA’BB’, 4H, aromatic). 13 C NMR (151 MHz, CDCl3) δ 14.3, 24.1, 31.4, 32.9, 60.6, 126.6, 130.6, 134.4, 143.1, 172.8, 194.9.

[0162]

Chemical Structure

[0163] <Example 18: Synthesis of 4,4'-Di(cyclopropylmethylthio)benzophenone> Under an argon atmosphere, 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, Cat. No. 456640, purchased from Sigma-Aldrich) of powdered polyether ether ketone was sequentially added with 86.5 mg (0.90 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.2 mmol) of phenylethylthiol, and then the reaction mixture was stirred at 150 °C.

[0164] After 20 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), 122 mg (0.9 mmol) of bromomethylcyclopropane was added, and the mixture was stirred at room temperature (25 °C) for 3.5 hours.

[0165] Subsequently, water and ethyl acetate were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. The target 4,4'-di(cyclopropylmethylthio)benzophenone was obtained in 98 mg (yield 92%) by silica gel column chromatography (developing solvent: hexane / ethyl acetate 96:4 → 7:3). 1 H NMR (600 MHz, CDCl3) δ 0.30 - 0.33 (m, 4H, cCH2), 0.62 - 0.65 (m, 4H, cCH2), 1.08 - 1.14 (m, 2H, cCH), 2.96 (d, J = 7.0 Hz, 4H, SCH2), 7.34 (AA’BB’, 4H, aromatic), 7.69 (AA’BB’, 4H, aromatic). 1313C NMR (151 MHz, CDCl3) δ 5.83, 10.1, 38.0, 126.4, 130.5, 134.2, 144.2, 195.0.

[0166]

Chem.

[0167] <Example 19: Synthesis of 4,4'-Di(4-oxiranylmethylthio)benzophenone> Under an argon atmosphere, 86.4 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, Cat. No. 456640, purchased from Sigma-Aldrich) of powdered polyether ether ketone, 87.4 mg (0.91 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.2 mmol) of phenylethyl mercaptan were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0168] After 20 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), and while cooling to 0 °C in an ice bath, 411 mg (3.0 mmol) of 3-bromo-1-propene oxide was added, and the mixture was stirred at room temperature (25 °C) for 20 hours.

[0169] Subsequently, water and methylene chloride were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and the crude product was obtained by distillation under reduced pressure. The target 4,4'-di(4-oxiranylmethylthio)benzophenone was obtained in an amount of 58 mg (yield 53%) by silica gel column chromatography (developing solvent: hexane / ethyl acetate 100:0 → 7:3) and preparative liquid chromatography (developing solvent: chloroform). 11H NMR (600 MHz, CDCl3) 2.65 (dd, J = 2.6, 4.8 Hz, 2H, methylene), 2.83 - 2.85 (m, 2H, methylene), 3.14 (dd, J = 6.8, 15.8 Hz, 2H, methylene), 3.22 - 3.25 (m, 4H), 7.43 (AA’BB’, 4H, aromatic), 7.71 (AA’BB’, 4H, aromatic). 13 13C NMR (151 MHz, CDCl3) 35.0, 47.3, 50.7, 127.4, 130.6, 134.9, 142.3, 194.8.

[0170]

Chemical formula

[0171] <Example 20: Synthesis of 4,4'-bis(3,7-dimethyloctylthio)benzophenone> Under an argon atmosphere, 1.15 g (3.99 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, Cat. No. 456640, purchased from Sigma-Aldrich) of powdered polyether ether ketone, 1.15 g (12.0 mmol) of sodium tert-butoxide, 8.0 mL of N,N-dimethylacetamide (DMAc), and 2.21 g (16.0 mmol) of phenylethylthiol were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0172] And after 22 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), 2.65 mg (12.0 mmol) of 1-bromo-3,7-dimethyloctane was added, and the mixture was stirred at 100 °C for 17 hours.

[0173] Next, 20 mL of ethyl acetate and hydrochloric acid (2 M, 10 mL) were added to this reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and the crude product was obtained by distillation under reduced pressure. From the crude product, silica gel column chromatography (developing solvent: hexane / ethyl acetate 96:4 → 7:3) and drying under reduced pressure (ca. 0.5 Torr) at 170 °C gave 1.70 g (yield 81%) of 4,4'-bis(3,7-dimethyloctylthio)benzophenone. 1 H NMR (600 MHz, CDCl3) δ 0.86 (d, J = 6.6 Hz, 12H, methyl), 0.94 (d, J = 6.6 Hz, 6H, methyl), 1.12 - 1.16 (m, 6H, methylene), 1.22 - 1.34 (m, 6H, methylene), 1.50 - 1.56 (m, 4H, methylene), 1.58 - 1.63 (m, 2H, methylene), 1.69 - 1.75 (m, 2H, methylene), 2.97 (ddd, J = 6.3, 9.6, 12.5 Hz, 2H, SCH2), 3.05 (ddd, J = 6.3, 9.6, 12.5 Hz, 2H, SCH2), 7.32 (AA’BB’, 4H, aromatic), 7.70 (AA’BB’, 4H, aromatic). 13 C NMR (151 MHz, CDCl3) δ 19.4, 22.6, 22.7, 24.7, 28.0, 30.0, 32.4, 35.9, 36.9, 39.2, 126.2, 130.5, 134.2, 144.1, 194.9.

[0174]

Chem.

[0175] <Example 21: Synthesis of 4,4'-di(1-ethyl-n-pentylcarbonylthio)benzophenone> In an argon atmosphere, 86.1 mg (0.30 mmol, calculated based on the molar weight of the monomer, average M w ~20,800, average M n ~10,300, Cat. No. 456640, purchased from Sigma-Aldrich), 87.0 mg (0.91 mmol) of sodium tert-butoxide, 0.6 mL of N,N-dimethylacetamide (DMAc), and 167 mg (1.2 mmol) of phenylethylthiol were sequentially added, and then the reaction mixture was stirred at 150 °C.

[0176] Then, after 22 hours, the reaction mixture (the first decomposition product) was returned to room temperature (25 °C), 147 mg (0.91 mmol) of 2-ethylhexanoyl chloride and 0.6 mL of tetrahydrofuran were added, and the mixture was stirred at room temperature (25 °C) for 5 hours.

[0177] Next, 5 mL of hydrochloric acid (0.5 M) and 5 mL of ethyl acetate were added to the obtained reaction mixture, and the organic layer of the reaction mixture was washed with water and a saturated aqueous sodium chloride solution. After extracting the organic layer, it was dried over anhydrous magnesium sulfate, and a crude product was obtained by distillation under reduced pressure. The target 4,4'-bis(1-ethyl-n-pentylcarbonylthio)benzophenone was obtained in an amount of 121 mg (yield 81%) by silica gel column chromatography (developing solvent: hexane / ethyl acetate 100:0 → 7:3) and preparative liquid chromatography (developing solvent: chloroform).

[0178]

Chemical formula

[0179] (Other embodiments) Although the organic solvent in the above-described embodiment does not contain moisture, the present invention is not limited thereto. The organic solvent may contain moisture.

[0180] In the above-described embodiment, in the first reaction step, a base is reacted with one substance selected from among an alkanethiol, an aromatic mercaptan, sodium sulfide, and elemental sulfur. However, the present invention is not limited to this. In the first reaction step, a base may be reacted with a plurality of substances selected from among an alkanethiol, an aromatic mercaptan, sodium sulfide, and elemental sulfur to polyether ether ketone.

[0181] Furthermore, in the above-described embodiment, in the second reaction step, one substance selected from among an alkyl halide, an acid halide, and hydrogen chloride is reacted. However, the present invention is not limited to this. In the second reaction step, a plurality of substances selected from among an alkyl halide, an acid halide, and hydrogen chloride may be reacted with the first reaction product.

Industrial Applicability

[0182] When the decomposition method of the present invention is used, sulfur-functionalized benzophenone and hydroquinone can be obtained from polyether ether ketone in good yield. Depending on the type of organic halide used after depolymerization, various benzophenone compounds can be obtained. Therefore, this depolymerization reaction can be used as a technique for obtaining various useful organic substances from polyether ether ketone.

Claims

1. A method for decomposing polyetheretherketone, which decomposes polyetheretherketone, comprising: a first reaction step of reacting the polyetheretherketone with a base and at least one of an alkanethiol, an aromatic mercaptan, sodium sulfide, and elemental sulfur in an organic solvent. A method for decomposing polyetheretherketone, characterized by the above.

2. The method for decomposing polyetheretherketone according to claim 1, wherein at least one of the alkanethiol, the aromatic mercaptan, sodium sulfide, and elemental sulfur is reacted with the polyetheretherketone in an amount of 0.1 to 6 equivalents.

3. The method for decomposing polyetheretherketone according to claim 1, wherein the base is reacted with the polyetheretherketone in an amount of 2 to 6 equivalents.

4. The method for decomposing polyetheretherketone according to any one of claims 1 to 3, wherein the first reaction step is carried out at 100 to 200 °C.

5. The base is at least one selected from the group consisting of sodium hydroxide, potassium hydroxide, potassium carbonate, potassium phosphate, cesium carbonate, sodium tert-butoxide, lithium tert-butoxide, potassium tert-butoxide, lithium bis(trimethylsilyl)amide, sodium bis(trimethylsilyl)amide, potassium bis(trimethylsilyl)amide, phosphazene base, t-Bu-P 4 (1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)-phosphoranylideneamino]-2λ 5 ,4λ 5 -catena-di(phosphazene)), t-Oct-P 4 (1-tert-octyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)-phosphoranylideneamino]-2λ 5 ,4λ 5 -catena-di(phosphazene)), and t-Bu-P 2 (1-tert-butyl-2,2,4,4,4-pentakis(dimethylamino)-2λ 5 ,4λ 5 -catena-di(phosphazene)) The method for decomposing polyetheretherketone according to claim 1, characterized by the above.

6. The organic solvent is at least one selected from the group consisting of 1,3-dimethyl-2-imidazolidinone, N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidone, benzonitrile, and 1,4-dioxane. The method for decomposing polyetheretherketone according to claim 1, characterized by the above.

7. A method for decomposing polyetheretherketone, comprising a second reaction step of reacting the first reaction product obtained by the first reaction step according to claim 1 with at least one of an alkyl halide, an acid halide, and hydrogen chloride. A method for decomposing polyetheretherketone, characterized by the above.

8. The alkyl halide is at least one selected from the group consisting of methyl iodide, 1-bromohexane, benzyl bromide, 2-phenylethyl bromide, 11-bromomethyltricosane, 1-bromo-3,7-dimethyloctane, 1,4-dichlorobenzene, 4-bromo-1-butene, ethyl 3-bromobutanoate, bromomethylcyclopropane, 2-bromoethanol, and 3-bromo-1-propene oxide. The acid halide is at least one selected from the group consisting of acetyl chloride, benzoyl chloride, and α-ethylhexanoic acid chloride. The method for decomposing polyetheretherketone according to claim 7, characterized by the above.

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