Aromatic thioether sulfone polymer, composition, molded article, and method for producing the same

Abstract

Provided are an aromatic thioether sulfone polymer, an aromatic thioether sulfone polymer composition, and an aromatic thioether sulfone polymer molded article that have a high refractive index, have less coloring, and have high transparency, and methods for producing the same. In detail, this aromatic thioether sulfone polymer is characterized by having a refractive index of 1.65 or more, a brightness of 85 or more, a transmission rate of 70% or more, and an oligomer content of 3.5 parts by mass or less. This method is for producing the aromatic thioether sulfone polymer.

Description

[Technical Field]

[0001] The present invention relates to an aromatic thioether sulfone polymer, a composition, a molded article, and a method for producing the same. [Background technology]

[0002] In recent years, resin materials have been widely used for optical materials such as optical lenses, prism sheets, and components for organic light-emitting diode (OLED) devices due to their excellent processability and productivity. Furthermore, the trend toward smaller and lighter optical components has created a demand for resin materials with high refractive indices. The typical refractive index of conventional resins is 1.30 to 1.70, and there are few general-purpose materials with a refractive index exceeding 1.70.

[0003] A common approach to increasing the refractive index of a resin is to introduce into the molecule a substituent with a high molar refraction, a small molar volume, and a high specific gravity, according to the Lorentz-Lorentz equation. That is, the introduction of halogen atoms or sulfur atoms is considered effective. Because sulfur atoms have high polarizability, stability, and ease of incorporation into polymers, sulfur-containing resins for various optical materials have been reported. For example, compounds with a thiourethane skeleton have been disclosed as sulfur-containing resins. However, these compounds have low heat resistance, posing a problem when used under high-temperature conditions (Patent Document 1, Patent Document 2, Patent Document 3).

[0004] On the other hand, aromatic polythioethers are promising high refractive index materials because they have a high sulfur content in the resin skeleton and very high density. In particular, aromatic thioether sulfone polymers are amorphous resins, which are highly transparent. Furthermore, they have a high glass transition temperature of approximately 220°C, which gives them excellent heat resistance. Therefore, they are expected to be optical materials that can be used even under high-temperature conditions. However, previously reported methods for producing aromatic thioether sulfone polymers have resulted in coloration of the resulting resins and a lack of transparency, which has prevented their use as optical materials (Patent Document 4, Patent Document 5). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 09-324023 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-003624 [Patent Document 3] JP 2009-256692 A [Patent Document 4] Japanese Patent Application Publication No. 4-275335 [Patent Document 5] International Publication No. 90 / 03210 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, an object of the present invention is to provide an aromatic thioether sulfone polymer, composition, and molded article having a high refractive index, little coloration, and high transparency, as well as methods for producing the same. [Means for solving the problem]

[0007] The present inventors conducted extensive research to solve the above problems and found that an aromatic thioether sulfone polymer having a high refractive index, little coloration, and high transparency can be provided by polymerizing a dihaloaromatic compound with (i) an alkali metal sulfide, or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide, in the presence of a carbamide solvent. Furthermore, the present inventors found that an aromatic thioether sulfone polymer having excellent thermal stability can be provided when the oligomer content is within a specific range.

[0008] That is, the present disclosure relates to an aromatic thioether sulfone polymer characterized by a refractive index of 1.65 or more, a brightness of 85 or more, a transmittance of 70% or more, and an oligomer content of 3.5 parts by mass or less.

[0009] The present disclosure also relates to a method for producing an aromatic thioether sulfone polymer, comprising polymerizing a dihaloaromatic compound with (i) an alkali metal sulfide, or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide, in a hydrous organic carbamide solvent.

[0010] In the present disclosure, a polymer having 2 to 40 repeating units (a mixture of dimers to 40-mers) may be referred to as an "oligomer." [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an aromatic thioether sulfone polymer having a high refractive index, little coloration, and high transparency, and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0012] The following describes in detail an embodiment of the present invention (hereinafter referred to as "the present embodiment"); however, the present invention is not limited to the following description and can be implemented in various modifications within the scope of its gist.

[0013] <Aromatic thioether sulfone polymer>

[0014] The aromatic thioether sulfone polymer is a polymer having, as a repeating unit, a structural moiety represented by the following general formula (1): (wherein R1 to R4 each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a nitro group, an amino group, a phenyl group, a methoxy group, or an ethoxy group, and X represents -O-, -SO2-, -SO-, or -CO-).

[0015] [ka]

[0016] Here, in the structural moiety represented by the general formula (1), it is particularly preferable that R1 to R4 in the formula are hydrogen atoms in terms of the mechanical strength of the aromatic thioether sulfone polymer.

[0017] Furthermore, the aromatic thioether sulfone polymer may contain not only the structural moiety represented by the general formula (1) but also structural moieties such as substituted phenyl groups, ketone groups, and aliphatic groups in an amount of 30 mol % or less of the total amount of the structural moiety represented by the general formula (1). The bonding mode of these structural moieties may be either a random copolymer or a block copolymer. The aromatic thioether sulfone polymer may also contain a trifunctional structural moiety represented by the following general formula (2). In this case, the amount of these structural moieties is preferably in the range of 0.001 to 10 mol %, particularly preferably 0.01 to 1 mol %, of the total number of moles of the structural moieties including the other structural moieties.

[0018] [ka]

[0019] The aromatic thioether sulfone polymer may also contain a structural moiety of a 9,9-bisarylfluorene skeleton represented by the following general formula (3): (wherein ring Z is an aromatic hydrocarbon ring; R5 and R6 may be any substituent, such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxy group; Y is -O-, -S-, -SO2-, -SO-, or -CO-; k is an integer of 0 to 4; m is an integer of 0 or greater; and p is an integer of 1 or greater). In the following general formula (3), ring Z may be a benzene ring or a naphthalene ring. In this case, the amount of ring Z is preferably in the range of 0.001 to 10 mol %, and particularly preferably in the range of 0.01 to 1 mol %, based on the total number of moles of ring Z and other structural moieties.

[0020] [ka]

[0021] Furthermore, when the 9,9-bisarylfluorene skeletal moiety is copolymerized, a compound represented by the following formula (4) can also be used (wherein ring Z is an aromatic hydrocarbon ring, R5 to R7 may be any substituent, such as an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkoxy group, Y is -O-, -S-, -SO2-, -SO-, or -CO-, k is an integer of 0 to 4, m is an integer of 0 or greater, and p is an integer of 1 or greater). In the following general formula (4), ring Z may be a benzene ring or a naphthalene ring. In this case, the amount is preferably in the range of 0.001 to 10 mol % relative to the total number of moles of the other structural moieties, and particularly preferably in the range of 0.01 to 1 mol %.

[0022] [ka]

[0023] The aromatic thioether sulfone polymer according to this embodiment has an excellent refractive index. Specifically, the refractive index is preferably 1.65 or more, and more preferably 1.70 or more. In the present disclosure, the refractive index is a value measured at room temperature (23°C) and 589 nm using a test piece of an aromatic thioether sulfone polymer molded to a thickness of 40 μm according to a method in accordance with JIS K 7142.

[0024] The aromatic thioether sulfone polymer according to this embodiment has excellent transparency. Specifically, the lightness is preferably 85 or more, more preferably 90 or more, and the transmittance is preferably 70% or more, more preferably 80% or more. In the present disclosure, the lightness is measured by a color difference meter using a 40 μm thick aromatic thioether sulfone polymer as a test piece against a white plate in accordance with JIS Z 8781-4. * The transmittance is the transmittance measured at a wavelength of 450 nm using an ultraviolet-visible spectrophotometer.

[0025] The aromatic thioether sulfone polymer according to this embodiment has an oligomer content of 3.5 parts by mass or less per 100 parts by mass. Within this range, the amount of gas generated when the polymer is heated and melted can be reduced, resulting in a polymer with excellent thermal stability. The oligomer content of the polymer in the present disclosure can be measured by the method described in the Examples.

[0026] The aromatic thioether sulfone polymer according to this embodiment has excellent melt stability and exhibits a small viscosity change rate when retained. Specifically, the viscosity change rate is preferably 10% or less, more preferably 8% or less. The viscosity change rate in the present disclosure can be measured by the method described in the examples.

[0027] The method for producing the aromatic thioether sulfone polymer is not particularly limited, and examples thereof include the method for producing an aromatic thioether sulfone polymer described below.

[0028] <Method of producing aromatic thioether sulfone polymer> A method for producing an aromatic thioether sulfone polymer according to a first embodiment of the present disclosure is characterized in that a dihaloaromatic compound is polymerized with (i) an alkali metal sulfide, or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide, in a hydrous organic carbamide solvent.

[0029] Further, a method for producing an aromatic thioether sulfone polymer according to a second embodiment of the present disclosure includes the steps of: (1) a step of polymerizing a dihaloaromatic compound with (i) an alkali metal sulfide, or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide in a water-containing organic carbamide solvent to obtain a crude reaction mixture; Step (2) washing the crude reaction mixture; Step (3) of subjecting the crude reaction mixture to solid-liquid separation to obtain a solid phase component (A); The method further comprises a step (4) of contacting the solid phase component (A) with an organic solvent and then subjecting the solid phase component (A) to solid-liquid separation to obtain a solid phase component (B).

[0030] Process (1) The aqueous organic carbamide solvent used in this embodiment is a mixture of water and an organic carbamide solvent. The organic carbamide solvent is not particularly limited as long as it is a compound having one or more carbamide groups, and known organic carbamide solvents can be used. Examples include dimethylimidazolidinone (DMI), dimethylpropylene urea (DMPU), hexamethylphosphoric triamide (HMPA), and tetramethylurea (TMU). DMI is particularly preferred from the viewpoints of thermal stability, smoothness of the polymerization reaction, and economic efficiency. The water content of the aqueous organic carbamide solvent is preferably 1 mol / kg or more, more preferably 5 mol / kg or more, and even more preferably 7 mol / kg or more, and preferably 30 mol / kg or less, and more preferably 20 mol / kg or less, relative to the organic carbamide solvent. If the water content is below this range, there is a high possibility of a decomposition reaction occurring. If the water content is above this range, there is a high possibility of a significant delay in the polymerization reaction and a significant decrease in the granulation rate of the resulting copolymer.

[0031] The dihaloaromatic compound used in the present embodiment is, for example, a halogenated aromatic compound having two halogen atoms directly bonded to an aromatic ring, and specifically, p-dichlorodiphenyl sulfone, o-dichlorodiphenyl sulfone, m-dichlorodiphenyl sulfone, p-dibromodiphenyl sulfone, o-dibromodiphenyl sulfone, m-dibromodiphenyl sulfone, p-diiododiphenyl sulfone, o-diiododiphenyl sulfone, m-diiododiphenyl sulfone, p-dichlorobenzene, o-dichlorodiphenyl sulfone, Examples of dihaloaromatic compounds include dichlorobenzene, m-dichlorobenzene, dibromobenzene, diiodobenzene, tribromobenzene, dibromonaphthalene, dichlorodiphenylbenzene, dibromodiphenylbenzene, dichlorobenzophenone, dibromobenzophenone, dichlorodiphenyl ether, dibromodiphenyl ether, dichlorodiphenyl sulfide, dibromodiphenyl sulfide, dichlorobiphenyl, and dibromobiphenyl, and mixtures thereof, and these compounds may be block copolymerized. Among these, dihalogenated benzenes are preferred, and those containing 80 mol % or more of p-dichlorodiphenyl sulfone are particularly preferred.

[0032] Further examples include dihaloaromatic compounds having a functional group with active hydrogen, such as an amino group, a thiol group, or a hydroxyl group. Specific examples include dihaloanilines such as 2,6-dichloroaniline, 2,5-dichloroaniline, 2,4-dichloroaniline, and 2,3-dichloroaniline; dihaloaminodiphenyl ethers such as 2,2'-diamino-4,4'-dichlorodiphenyl ether and 2,4'-diamino-2',4-dichlorodiphenyl ether; and mixtures thereof in which the amino group is replaced with a thiol group or a hydroxyl group.

[0033] In addition, active hydrogen-containing dihaloaromatic compounds in which the hydrogen atoms bonded to the carbon atoms forming the aromatic rings in these active hydrogen-containing dihaloaromatic compounds are substituted with other inert groups, for example, hydrocarbon groups such as alkyl groups, can also be used.

[0034] Among these various active hydrogen-containing dihaloaromatic compounds, active hydrogen-containing dihaloaromatic compounds are preferred, and dichloroaniline is particularly preferred.

[0035] Examples of dihaloaromatic compounds having a nitro group include dihalonitrobenzenes such as 2,4-dinitrochlorobenzene and 2,5-dichloronitrobenzene; dihalonitrodiphenyl ethers such as 2-nitro-4,4'-dichlorodiphenyl ether; dihalonitrodiphenyl sulfones such as 3,3'-dinitro-4,4'-dichlorodiphenyl sulfone; mono- or dihalonitropyridines such as 2,5-dichloro-3-nitropyridine and 2-chloro-3,5-dinitropyridine; or various dihalonitronaphthalenes; 9,9-bis(4-chlorophenyl)fluorene, 9,9-bis(4-bromophenyl)fluorene, 9,9-bis(4-iodophenyl)fluorene, 9,9-bis(4-chloro-3-methylphenyl)fluorene, 9,9-bis(4-bromophenyl)fluorene, 9,9-bis(4-iodophenyl)fluorene, 9,9-bis(4-bromo ... and dihalofluorenes such as 9,9-bis(4-iodo-3-methylphenyl)fluorene, 9,9-bis(4-chloro-3-ethylphenyl)fluorene, 9,9-bis(4-bromo-3-ethylphenyl)fluorene, 9,9-bis(4-iodo-3-ethylphenyl)fluorene, 9,9-bis(4-chloro-3-isopropylphenyl)fluorene, 9,9-bis(4-bromo-3-isopropylphenyl)fluorene, 9,9-bis(4-iodo-3-isopropylphenyl)fluorene, 9,9-bis(4-chloro-3,5-dimethylphenyl)fluorene, 9,9-bis(4-bromo-3,5-dimethylphenyl)fluorene, and 9,9-bis(4-iodo-3,5-dimethylphenyl)fluorene.

[0036] In this embodiment, an alkali metal sulfide, or an alkali hydrosulfide and an alkali metal hydroxide (hereinafter, sometimes referred to as a sulfidizing agent) is used as a raw material.

[0037] In this embodiment, the alkali metal sulfide includes lithium sulfide, sodium sulfide, rubidium sulfide, cesium sulfide, and mixtures thereof. Such alkali metal sulfides can be used as hydrates, aqueous mixtures, or anhydrides. The alkali metal sulfide can also be derived by reacting an alkali metal hydrosulfide with an alkali metal hydroxide. A small amount of alkali metal hydroxide may be added to react with the alkali metal hydrosulfide and alkali metal thiosulfate, which are usually present in trace amounts in the alkali metal sulfide.

[0038] The alkali metal hydrosulfides include lithium hydrogen sulfide, sodium hydrogen sulfide, rubidium hydrogen sulfide, cesium hydrogen sulfide, and mixtures thereof. These alkali metal hydrosulfides can be used as hydrates, aqueous mixtures, or anhydrous forms.

[0039] The alkali metal hydrosulfide is used together with an alkali metal hydroxide. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. These may be used alone or in combination of two or more. Among these, lithium hydroxide, sodium hydroxide, and potassium hydroxide are preferred because of their easy availability, and sodium hydroxide is particularly preferred.

[0040] The amount of sulfidizing agent used in this step is preferably 0.1 mol / kg, more preferably 0.3 mol / kg, and preferably 20 mol / kg or less, more preferably 10 mol / kg or less, relative to the organic carbamide solvent. If it is less than 0.1 mol / kg, the productivity of the polymer will be low, which is disadvantageous from an economic standpoint. On the other hand, if it is more than 20 mol / kg, the viscosity of the system will increase during the reaction, making stirring difficult and potentially resulting in a low yield.

[0041] In this step, the molar ratio of the dihaloaromatic compound to the sulfidizing agent is preferably in the range of 0.95 to 1.2 (mol / mol), more preferably in the range of 1.00 to 1.10 (mol / mol). If it is less than 0.95 (mol / mol), a decomposition reaction may occur or the thermal stability of the resulting aromatic copolymer may be poor. If it is more than 1.2 (mol / mol), the polymerization reaction may not proceed easily, making it difficult to achieve a high molecular weight.

[0042] The polymerization conditions for the sulfidizing agent and dihaloaromatic compound in the presence of the organic carbamide solvent are generally a temperature of 150 to 330°C, and a pressure within a range that maintains the polymerization solvent and the dihaloaromatic compound (polymerizable monomer) substantially in liquid phase. This pressure is generally selected from the range of 0.1 to 20 MPa, preferably 0.1 to 2 MPa. The reaction time varies depending on the temperature and pressure, but is generally within the range of 10 minutes to 72 hours, preferably 1 to 10 hours. To obtain an aromatic thioether sulfone polymer with a higher molecular weight, it is preferable to use a two- or more-stage reaction temperature profile. When performing this two-stage operation, the first stage is preferably performed at 90°C or higher, as this ensures a practical reaction rate that is not too low. The first stage is preferably performed at a temperature of 180°C or lower, as this results in an aromatic thioether sulfone polymer with a sufficiently high molecular weight and does not increase the side reaction rate. Furthermore, a temperature of 120 to 160°C is particularly preferred. At the end of the first stage, the residual dihaloaromatic compound rate in the polymerization reaction system is preferably 1 mol % or more, since it is easy to obtain a high molecular weight aromatic thioether sulfone polymer in the end, and is preferably 40 mol % or less, since side reactions such as depolymerization are unlikely to occur in the second stage reaction. The temperature is then raised, and the final stage reaction is preferably carried out at 180 to 300°C for 1 to 50 hours. Regarding the temperature range, a reaction temperature of 180°C or higher is preferred, since it is easy to obtain a sufficiently high molecular weight aromatic thioether sulfone polymer, and a reaction temperature of 300°C or less is preferred, since it is easy to obtain a high molecular weight product without side reactions such as depolymerization.

[0043] This embodiment also encompasses an embodiment in which the crude reaction product is obtained by reacting a dihaloaromatic compound and an organic carbamide-based solvent in the presence of a sulfidizing agent and an organic carbamide-based solvent while continuously or intermittently adding the dihaloaromatic compound and the organic carbamide-based solvent.

[0044] In this way, by polymerizing a dihaloaromatic compound with a sulfidizing agent in an organic carbamide solvent, an aromatic thioether sulfone polymer is obtained as a product, but oligomers are also produced as by-products. The crude reaction mixture after the reaction may also contain by-products such as alkali metal-containing inorganic salts and terminal SH group-containing compounds, as well as unreacted raw materials.

[0045] Process (2) Step (2) is a step of washing the crude reaction mixture obtained in step (1).

[0046] The solvent used to wash the crude reaction mixture in this step is not particularly limited as long as it is compatible with the organic carbamide solvent and the unreacted monomer at or below the boiling point, but from the viewpoint of compatibility, it is preferable to use a solvent similar to the organic carbamide solvent used in step (1).Preferred solvents other than the organic carbamide solvent include amide, ester, and ether solvents, and specific examples include N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), and dimethylacetamide (DMAc).

[0047] The temperature at which the washing solvent is added is not particularly limited, but is preferably in the range of 10° C. or higher, more preferably 20° C. or higher, and preferably 200° C. or lower, more preferably 150° C. or lower. The amount of the solvent used for one washing is not particularly limited, but is preferably 20 parts by mass or higher, more preferably 50 parts by mass or higher, even more preferably 100 parts by mass or higher, and preferably 5,000 parts by mass or lower, more preferably 1,800 parts by mass or lower, and even more preferably 600 parts by mass or lower, relative to 100 parts by mass of the aromatic thioether sulfone polymer.

[0048] Process (3) Step (3) is a step of subjecting the crude reaction mixture that has been subjected to step (2) to solid-liquid separation to obtain a solid phase component (A) that contains at least an aromatic thioether sulfone polymer.

[0049] The method for solid-liquid separation is not particularly limited, and known devices and methods can be used. For example, an appropriate method can be selected, such as vacuum distillation, centrifugation, screw decanter, vacuum filtration, or pressure filtration. These methods can also be combined or repeated. Furthermore, steps (2) and (3) can also be repeated.

[0050] The degree of separation and removal of the liquid phase component containing the organic carbamide solvent is not particularly limited, but the proportion of solids in the solid phase component (A) (solids concentration) is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, and even more preferably 55 parts by mass or more, per 100 parts by mass of the solid phase component (A). The upper limit is not limited, but is preferably 100 parts by mass or less, more preferably less than 100 parts by mass, and even more preferably 99 parts by mass or less.

[0051] Process (4) Step (4) is a step in which the solid phase component (A) obtained in step (3) is contacted with an organic solvent and then subjected to solid-liquid separation to obtain a solid phase component (B).

[0052] The organic solvent that can be used in this step is not particularly limited, and known organic solvents can be used. For example, amides, ureas, and lactams such as formamide, acetamide, N-methylformamide, N,N-dimethylacetamide, tetramethylurea, N-methyl-2-pyrrolidone, 2-pyrrolidone, N-methyl-ε-caprolactam, ε-caprolactam, hexamethylphosphoramide, N-dimethylpropyleneurea, and 1,3-dimethyl-2-imidazolidinonic acid; sulfolanes such as sulfolane and dimethylsulfolane; nitriles such as benzonitrile; methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, t-butyl alcohol, ethylene glycol, propylene glycol, trimethylolpropane, and the like can be used. Examples of suitable organic solvents include alcohols having 10 or fewer carbon atoms, such as diolpropane and benzyl alcohol; alcohols having 10 or fewer carbon atoms and containing an ether bond, such as 2-methoxyethyl alcohol, 2-ethoxyethyl alcohol, 1-methoxy-2-propyl alcohol, 1-ethoxy-2-propyl alcohol, 3-methoxy-1-butyl alcohol, and 2-isopropoxyethyl alcohol; alcohols having 10 or fewer carbon atoms and containing a ketone group, such as 3-hydroxy-2-butanone; alcohols having 10 or fewer carbon atoms and containing an ester group, such as methyl hydroxyisobutyrate; ketones, such as methyl phenyl ketone, and mixtures thereof. Among these, alcohols and ketones are preferred. Mixtures of two or more of the above organic solvents may also be used. Furthermore, the organic solvent may contain water.

[0053] In this embodiment, the polar organic solvent is preferably an alcohol or ketone organic solvent, since it can efficiently remove impurities such as residual oligomers, and more preferably an aqueous alcohol, since it can efficiently remove salts produced during polymerization. When an aqueous alcohol is used, the concentration of the alcohol solvent in the aqueous solution is not particularly limited, but the amount of the alcohol solvent is preferably in the range of 1,000 parts by mass or less, more preferably 500 parts by mass or less, to 25 parts by mass or more, more preferably 45 parts by mass or more, per 100 parts by mass of water.

[0054] The conditions for contacting the solid phase component (A) with the organic solvent in this step are preferably in the range of 10°C or higher, more preferably 20°C or higher, to preferably 100°C or lower, more preferably 70°C or lower, and the pressure (gauge pressure) is less than 0.1 MPa, preferably 0.05 MPa or lower, and more preferably atmospheric pressure.

[0055] The amount of organic solvent used in this step is not particularly limited, but in order to achieve favorable washing efficiency, it is preferably 50 parts by mass or more, more preferably 100 parts by mass or more, even more preferably 200 parts by mass or more, and preferably 10,000 parts by mass or less, more preferably 5,000 parts by mass or less, even more preferably 2,000 parts by mass or less, relative to 100 parts by mass of the aromatic thioether sulfone polymer.

[0056] After washing, the solid-liquid separation to obtain the solid phase component (B) can be carried out by the same method as in step (3). The aromatic thioether sulfone polymer separated by filtration can be dried as it is and used as an aromatic thioether sulfone polymer powder, or it can be further washed with warm water, hot water, or the like, followed by solid-liquid separation and drying to prepare a powdery or granular aromatic thioether sulfone polymer. Furthermore, the obtained powdery or granular aromatic thioether sulfone polymer can be heat-treated to form a crosslinked aromatic thioether sulfone polymer.

[0057] The aromatic thioether sulfone polymer obtained by the above production method has an excellent refractive index. Specifically, the refractive index is preferably 1.65 or more, more preferably in the range of 1.7 or more to 1.8 or less. In the present disclosure, the refractive index is a value measured at room temperature (23°C) and 589 nm using a test piece of an aromatic thioether sulfone polymer melt-molded to a thickness of 40 μm according to a method in accordance with JIS K 7142.

[0058] The aromatic thioether sulfone polymer obtained by the above-mentioned production method is also excellent in transparency. Specifically, the brightness is preferably 85 or more, more preferably in the range of 90 or more and preferably 99.9 or less. The transmittance is preferably 70% or more, more preferably in the range of 80% or more and preferably 99.9 or less. In the present disclosure, the brightness is measured by a color difference meter using a 40 μm thick melt-molded aromatic thioether sulfone polymer as a test piece against a white plate in accordance with JIS Z 8781-4, and is determined by a reflection measurement of the aromatic thioether sulfone polymer against a white plate in accordance with JIS Z 8781-4. * The transmittance is the transmittance measured at a wavelength of 450 nm using an ultraviolet-visible spectrophotometer.

[0059] Furthermore, the aromatic thioether sulfone polymer obtained by the above production method has a low oligomer content. Specifically, the oligomer content per 100 parts by mass is preferably 3.5 parts by mass or less, more preferably 2 parts by mass or less, and even more preferably 1.8 parts by mass or less. Within this range, the amount of gas generated when the polymer is heated and melted can be reduced. The oligomer content of the polymer in the present disclosure can be measured by the method described in the Examples.

[0060] Furthermore, the aromatic thioether sulfone polymer obtained by the above-described production method has excellent melt stability and exhibits a small viscosity change rate when retained. Specifically, the viscosity change rate is preferably 10% or less, more preferably 8% or less. The viscosity change rate in the present disclosure can be measured by the method described in the Examples.

[0061] <Composition and method for producing the composition> The aromatic thioether sulfone polymer composition according to the present embodiment is obtained by blending the aromatic thioether sulfone polymer according to the present embodiment described above with other substances. The method for producing the composition according to the present embodiment includes the steps of blending the aromatic thioether sulfone polymer produced by the above method with other substances and melt-kneading the blended mixture.

[0062] The aromatic thioether sulfone polymer according to this embodiment can be used as a composition by incorporating other additives such as a mold release agent, a colorant, a heat stabilizer, an ultraviolet stabilizer, a foaming agent, a rust inhibitor, a flame retardant, a lubricant, a coupling agent, and a filler, as long as the effects of the present invention are not impaired. As the filler, any known or commonly used material can be used as long as it does not impair the effects of the present invention, and examples thereof include inorganic fillers of various shapes, such as fibrous ones and non-fibrous ones such as granular or plate-like ones. Specifically, fibrous fillers such as glass fiber, carbon fiber, silane glass fiber, ceramic fiber, aramid fiber, metal fiber, potassium titanate, silicon carbide, calcium silicate, wollastonite, and other fibers, and natural fibers can be used. Non-fibrous fillers such as glass beads, glass flakes, barium sulfate, clay, pyrophyllite, bentonite, sericite, mica, talc, attapulgite, ferrite, calcium silicate, calcium carbonate, glass beads, zeolite, milled fiber, and calcium sulfate can also be used.

[0063] The aromatic thioether sulfone polymer according to this embodiment can also be used as a composition by mixing it with other substances, such as synthetic resins and elastomers, as described below, within the scope of not impairing the effects of the present invention. Examples of these synthetic resins include polyester, polyamide, polyimide, polyetherimide, polycarbonate, polyphenylene ether, polysulfone, polyethersulfone, polyetheretherketone, polyetherketone, polyarylene, polyarylene sulfide, polyethylene, polypropylene, polytetrafluoroethylene, polydifluoroethylene, polystyrene, ABS resin, epoxy resin, silicone resin, phenolic resin, urethane resin, and liquid crystal polymer. Examples of elastomers include polyolefin rubber, fluororubber, and silicone rubber.

[0064] The method for blending and kneading the above components with the aromatic thioether sulfone polymer according to the present embodiment is not particularly limited, but examples include a method in which the aromatic thioether sulfone polymer and optional components, as necessary, are blended and melt-kneaded; more specifically, a method in which the mixture is dry-mixed uniformly using a tumbler, a Henschel mixer, or the like, as necessary, and then charged into a twin-screw extruder and melt-kneaded.

[0065] From the viewpoints of dispersibility and productivity, the melt-kneading machine is preferably a twin-screw kneading extruder. For example, it is preferable to melt-knead while appropriately adjusting the resin component discharge rate in the range of 5 to 500 (kg / hr) and the screw rotation speed in the range of 50 to 500 (rpm). It is even more preferable to melt-knead under conditions where the ratio (discharge rate / screw rotation speed) is in the range of 0.02 to 5 (kg / hr / rpm). Furthermore, the components may be added and mixed simultaneously or in portions into the melt-kneading extruder. For example, when additives are added, it is preferable from the viewpoint of dispersibility to feed them into the twin-screw kneading extruder through a side feeder. Regarding the position of the side feeder, the ratio of the distance from the extruder's resin input section (top feeder) to the side feeder to the total screw length of the twin-screw kneading extruder is preferably 0.1 or more, more preferably 0.3 or more. Furthermore, this ratio is preferably 0.9 or less, more preferably 0.7 or less.

[0066] The aromatic thioether sulfone polymer composition according to the present embodiment obtained by melt-kneading in this manner has a morphology in which the aromatic thioether sulfone polymer forms a continuous phase and other essential components and optional components are dispersed. After the melt-kneading, the aromatic thioether sulfone polymer composition according to the present embodiment is preferably prepared by a known method, for example, by extruding the molten polymer composition into a strand shape, processing it into pellets, chips, granules, powder, or the like, and then pre-drying it at a temperature in the range of 100 to 150°C as needed.

[0067] <Molded products and manufacturing methods for molded products> The molded article according to the present embodiment is obtained by melt-molding the aromatic thioether sulfone polymer composition according to the present embodiment described above. The method for producing the molded article according to the present embodiment is characterized by comprising a step of melt-molding the aromatic thioether sulfone polymer composition obtained by the method for producing the aromatic thioether sulfone polymer composition according to the present embodiment described above.

[0068] The aromatic thioether sulfone polymer composition can be molded by various molding methods such as injection molding, compression molding, extrusion molding of composites, sheets, pipes, etc., pultrusion molding, blow molding, transfer molding, etc. When molding by injection molding, various molding conditions are not particularly limited, and molding can be performed by a commonly used method.

[0069] The applications of the aromatic thioether sulfone polymer and polymer composition according to this embodiment are not particularly limited, and they can be used in a variety of products. For example, they can be widely used as electrical and electronic components such as connectors, printed circuit boards, and encapsulated molded products; automotive components such as lamp reflectors and various electrical components; interior materials for various buildings, aircraft, and automobiles; and precision components such as office equipment components, camera components, and watch components. In particular, due to their excellent refractive index and transparency, they are suitable for various optical materials such as eyeglass lenses, camera lenses, plastic lenses such as prism lenses, hard coating agents, anti-reflection films, prism lenses, and LED encapsulation materials. [Example]

[0070] The present invention will be described in more detail below with reference to examples, which are illustrative and not limiting.

[0071] <Evaluation>

[0072] (1) Measurement of oligomer content The polymer obtained in each example and comparative example was weighed into a 10,0000 g flask using a precision balance. After extraction with acetone for 1 hour using a Soxhlet extractor, the acetone solution was dried in an oven at 50°C, and the oligomer content of each sample was calculated from the residue using the following formula. The measurement results are shown in Table 1. (Weight of residue after drying) ÷ (Weight of polymer used for extraction) × 100

[0073] (2) Refractive index measurement The polymers obtained in each Example and Comparative Example were melt-molded into a 40 μm thick film and used as test pieces. The refractive index at a wavelength of 589 nm was measured using a Metricon Prism Coupler in accordance with JIS K 7142. The measurement results are shown in Table 1.

[0074] (3) Lightness (L * Measurement of (value) The polymers obtained in each example and comparative example were melt-molded into a film having a thickness of 40 μm and used as test pieces. The lightness was measured using a colorimeter "ZE 6000" manufactured by Nippon Denshoku Industries Co., Ltd. The measurement was carried out in accordance with JIS Z 8781-4, and the lightness (L * The larger the value, the less coloration of the polymer. The measurement results are shown in Table 1.

[0075] (4) Transmittance measurement The polymers obtained in each example and comparative example were melt-molded into a 40 μm thick film and used as test pieces. The transmittance at 450 nm was measured using a Shimadzu UV-3150 ultraviolet-visible spectrophotometer. The measurement results are shown in Table 1.

[0076] (5) Measurement of the amount of gas generated The polymer obtained in each example and comparative example was weighed into a 4.0000 g aluminum dish using a precision balance. The sample was left to stand in a dryer set at 150°C for 1 hour, then the dish was removed and allowed to cool to room temperature before being weighed. The same dish was then left to stand in a dryer set at 370°C for 1 hour, then the dish was removed and allowed to cool to room temperature before being weighed. The weight loss of each sample was calculated using the following formula. The measurement results are shown in Table 1. {(Weight after heating to 150°C) - (Weight after heating to 370°C)} ÷ (Weight after heating to 150°C) × 100

[0077] (6) Evaluation of melt viscosity and melt stability The viscosity change rate of the polymers obtained in each example and comparative example was calculated from the values ​​measured using a Shimadzu flow tester "CFT-500D" at a temperature of 300°C, a load of 1.96 MPa, and an orifice with an orifice length to orifice diameter ratio of 10 / 1, using the following formula. The viscosity change rate is an absolute value. The measurement results are shown in Table 1. Viscosity change rate (%) = |(melt viscosity measured after 30 minutes (Pa·s) / melt viscosity measured after 6 minutes (Pa·s))| × 100

[0078] (7)DSC measurement The glass transition temperature (Tg) of the polymers obtained in each of the Examples and Comparative Examples was measured using a differential scanning calorimeter (Perkin Elmer's "DSC8500").

[0079] <Example 1, Comparative Examples 1 to 3>

[0080] Example 1 - Step (1) A 1 L titanium autoclave was charged with 4,4-dichlorodiphenyl sulfone (0.52 mol, 147.88 g), sodium acetate (0.50 mol, 41.02 g), dimethylimidazolidinone (DMI) (3.82 mol, 436.54 g), deionized water (2.22 mol, 39.96 g), sodium sulfide (47.6%, 0.50 mol, 59.34 g), and sodium hydroxide (48.8%, 0.50 mol, 41.08 g), and the mixture was heated to 200°C and then heated at 200°C for 3 hours under a sealed condition.

[0081] Example 1 - Step (2) After the polymerization was completed, the crude reaction mixture was collected in a container and DMI (300 mL) was added. The slurry was filtered through a 200-mesh wire mesh to obtain a solid phase component. DMI (300 mL) was further added to the obtained solid phase component, and the mixture was heated and stirred at 120°C for 30 minutes. The slurry was then cooled to 60°C.

[0082] Example 1 - Step (3) The cooled slurry was filtered through a 200 mesh wire screen to remove the liquid phase component.

[0083] Example 1 - Step (4) The obtained solid phase component was cooled to room temperature, and then an aqueous methanol solution was added, followed by decantation and filtration to remove the liquid phase component. The solid phase component was further washed with warm water (70°C), decanted, and filtration to remove the liquid phase component. This process was repeated three times. The obtained solid phase component was dried at 120°C for 2 hours under normal pressure, and then further dried under reduced pressure at 150°C for 5 hours to obtain polymer (1). The properties of the obtained polymer (1) are shown in Table 1.

[0084] Comparison Example 1 Polymer (2) was obtained in the same manner as in Example 1, except that NMP was used instead of DMI in steps (1) and (2). The properties of the obtained polymer are shown in Table 1.

[0085] Comparative Example 2 A 1 L autoclave was charged with 4,4-dichlorodiphenyl sulfone (0.54 mol, 154.70 g), sodium carbonate (0.53 mol, 56.60 g), sodium acetate (0.53 mol, 43.70 g), sodium hydroxide (0.53 mol, 62.82 g), sodium sulfide (47.6%, 0.53 mol, 62.82 g), NMP (2.13 mol, 221.70 g), and deionized water (0.13 mol, 2.27 g). The autoclave was heated to 200 °C and maintained at 200 °C for 3 h under a sealed condition. A mixture of 160 mL of NMP and 26.7 mL of deionized water was then added and stirred until the temperature reached 150 °C. The reaction mixture was removed from the reactor as a solid granular material, and the liquid was suction filtered. The resulting solid phase was washed with 600 mL of deionized water (90 °C) and filtered. This process was repeated twice with a final wash in room temperature deionized water. 40 g of the purified and recovered polymer, 400 g of deionized water, and 4.0 g of zinc acetate were added to a 1 L autoclave and heated to 185°C with stirring for 1 hour. The mixture was then cooled to room temperature (23°C). The resulting slurry was washed with hot water (90°C, 400 mL) while stirring. The slurry was then dried under reduced pressure at 160°C to obtain polymer (3). The properties of the resulting polymer are shown in Table 1.

[0086] Comparative Example 3 Sodium hydrosulfide (47.6%, 0.50 mol, 58.87 g), sodium hydroxide (48.8%, 0.45 mol, 36.89 g), anhydrous sodium acetate (0.25 mol, 20.51 g), sodium carbonate (0.06 mol, 6.36 g), and NMP (4.00 mol, 396.72 g) were added to a 1-L autoclave and heated at 130 °C for 3 hours under a sealed condition. The system was cooled to 70 °C, and 4,4-dichlorodiphenyl sulfone (0.51 mol, 146.45 g) was added along with NMP (0.50 mol, 49.59 g). The system was heated at 260 °C for 2 hours and then cooled to 120 °C at a rate of 1 °C / min. The system was extracted into NMP (1.5 mol, 148.77 g) and filtered through a 200-mesh wire mesh at 70 °C to remove the liquid phase. The obtained solid phase component was washed five times with 250 mL of warm water at 70° C., and finally 5 mL of acetic acid was added to obtain polymer (4). The properties of the obtained polymer are shown in Table 1.

[0087] [Table 1]

[0088] From Table 1, it can be seen that the aromatic thioether sulfone polymers of the examples have a low oligomer content and are excellent in brightness and transmittance. Furthermore, the small amount of gas generated and the small rate of change in viscosity indicate that they have excellent thermal stability.

Claims

1. A method for producing an aromatic thioether sulfone polymer, comprising polymerizing a dihaloaromatic compound with (i) an alkali metal sulfide, or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide, in a hydrous organic carbamide solvent, wherein the oligomer content is 3.5 parts by mass or less.

2. a step (1) of polymerizing a dihaloaromatic compound with (i) an alkali metal sulfide, or (ii) an alkali metal hydrosulfide and an alkali metal hydroxide in an aqueous organic carbamide solvent to obtain a crude reaction mixture; Step (2) of washing the crude reaction mixture; Step (3) of subjecting the crude reaction mixture to solid-liquid separation to obtain a solid phase component (A); (4) contacting the solid phase component (A) with an organic solvent and then subjecting it to solid-liquid separation to obtain a solid phase component (B); and 2. The method for producing an aromatic thioether sulfone polymer according to claim 1, wherein the molar ratio of the dihaloaromatic compound to (i) the alkali metal sulfide, or (ii) the alkali metal hydrosulfide and alkali metal hydroxide in step (1) is 0.95 to 1.

2.

3. The method for producing an aromatic thioether sulfone polymer according to claim 1 or 2, wherein the resulting polymer has a refractive index of 1.65 or more, a brightness of 85 or more, and a transmittance of 70% or more (wherein the brightness and transmittance are values ​​measured on a film-like test piece having a thickness of 40 μm, the brightness is a value measured by reflection using a white plate as a background in accordance with JIS Z 8781-4, and the transmittance is a value measured at a wavelength of 450 nm).

4. The method for producing an aromatic thioether sulfone polymer according to claim 1 or 2, wherein the viscosity change rate of the obtained polymer is 0 to 10% (provided that the viscosity change rate is calculated from values ​​measured with a flow tester at a temperature of 300°C, a load of 1.96 MPa, and using an orifice with an orifice length to orifice diameter ratio of 10 / 1, using the following formula): Viscosity change rate [%] = |(melt viscosity measured after 30 minutes [Pa·s] / melt viscosity measured after 6 minutes [Pa·s])| × 100

5. A method for producing an aromatic thioether sulfone polymer composition, comprising a step of blending the aromatic thioether sulfone polymer produced by the method according to claim 1 or 2 with other substances, followed by melt-kneading.

6. A method for producing a molded article, comprising the step of melt-molding the aromatic thioether sulfone polymer composition produced by the method of claim 5.

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