Aromatic polysulfone

Abstract

This aromatic polysulfone includes a repeating unit S1 derived from a compound represented by formula (S1), and a repeating unit S2 represented by formula (S2), wherein the repeating unit S1 content relative to all repeating units of the aromatic polysulfone is greater than or equal to 0.10 mol% and less than 1.50 mol%. (In formula (S1), R1, R2, and R3 each independently represent a hydrogen atom or a methyl group. In formula (S2), R5 and R6 each independently represent a halogen atom, a phenyl group, a C1-6 alkyl group, or a C2-10 alkenyl group, m and n each independently represent an integer from 0 to 4, and when there are a plurality of R5 or R6, these may be the same or different.)

Description

Aromatic Polysulfone

[0001] This disclosure relates to aromatic polysulfones. This application claims priority to Japanese Patent Application No. 2024-036119, filed on March 8, 2024, the contents of which are incorporated herein by reference.

[0002] Aromatic polysulfones have a high glass transition temperature (Tg) and are used in many fields, such as electronic materials, as materials with excellent heat resistance. For example, Patent Document 1 discloses that by using at least 20 mol % of trimethylhydroquinone, based on the total amount of dihydroxy components, as a monomer constituting aromatic polysulfone, the resulting polymer exhibits high thermal stability and is suitable as a membrane material.

[0003] Special Publication No. 2020-525600

[0004] Aromatic polysulfone generally has a high Tg and a high processing temperature. Therefore, if aromatic polysulfone remains in a molding machine, the high processing temperature may cause partial polymerization of the aromatic polysulfone, resulting in a high molecular weight and thickening. If the aromatic polysulfone thickens, stable molding becomes difficult, and the molding machine must be disassembled and cleaned, which may result in a decrease in productivity.

[0005] An object of the present disclosure is to provide an aromatic polysulfone that is inhibited from thickening at high temperatures (for example, 400°C).

[0006] The present disclosure encompasses the following aspects.

[0007] [1] An aromatic polysulfone comprising a repeating unit S1 derived from a compound represented by the following formula (S1) and a repeating unit S2 represented by the following formula (S2), wherein the content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone is 0.10 mol % or more and less than 1.50 mol %. (In formula (S1), R １ , R ２ and R ３ each independently represents a hydrogen atom or a methyl group) (In formula (S2), R ５ and R６ each independently represents a halogen atom, a phenyl group, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; m and n each independently represent an integer of 0 to 4; R ５ or R ６ If there are multiple, they may be the same or different)

[0008] [2] The aromatic polysulfone according to [1], wherein the content of the repeating unit S1 relative to the total repeating units is 0.10 mol % or more and 0.50 mol % or less.

[0009] [3] The aromatic polysulfone according to [1] or [2], wherein the compound represented by formula (S1) is trimethylhydroquinone or 2,3-dimethylhydroquinone.

[0010] According to the present disclosure, it is possible to provide an aromatic polysulfone in which thickening at high temperatures such as 400°C is suppressed.

[0011] <<Aromatic Polysulfone>> The aromatic polysulfone of the present embodiment is an aromatic polysulfone containing a repeating unit S1 derived from a compound represented by the following formula (S1) and a repeating unit S2 represented by the following formula (S2), wherein the content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone is 0.10 mol % or more and less than 1.50 mol %. (In formula (S1), R １ , R ２ and R ３ each independently represents a hydrogen atom or a methyl group) (In formula (S2), R ５ and R ６ each independently represents a halogen atom, a phenyl group, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; m and n each independently represent an integer of 0 to 4; R ５ or R ６ If there are multiple, they may be the same or different)

[0012] In this specification, the term "derived from" means that the chemical structure of the molecular structure changes at the site where a new bond is formed during polymerization due to the polymerization of the raw material monomer, but no other structural changes occur. The term "derived from" as used herein is a concept that also encompasses cases where the polymerizable derivative of the raw material monomer is used as the origin.

[0013] [Repeating Unit S1] The content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone is preferably 0.10 mol % or more and 0.50 mol % or less.

[0014] The compound represented by the formula (S1) includes: methylhydroquinone (i.e., R １ ~R ３ is a hydrogen atom), 2,3-dimethylhydroquinone (i.e., a compound in which R １ is a methyl group, and R ２ and R ３ is a hydrogen atom), 2,5-dimethylhydroquinone (i.e., a compound where R ２ is a methyl group, and R １ and R ３ is a hydrogen atom), 2,6-dimethylhydroquinone (i.e., a compound in which R ３ is a methyl group, and R １ and R ２ is a hydrogen atom), trimethylhydroquinone (i.e., compounds where R １ and R ２ is a methyl group, and R ３ is a hydrogen atom), tetramethylhydroquinone (i.e., compounds where R １ ~R ３ is a methyl group). Among these, trimethylhydroquinone or 2,3-dimethylhydroquinone is preferred.

[0015] [Repeating unit S2] In the above formula (S2), R ５ and R ６ The alkyl group in may be linear or branched, and specific examples include a methyl group, an ethyl group, a 1-propyl group, an isopropyl group, a 1-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, and an n-hexyl group.

[0016] In the above formula (S2), R ５ and R ６ Examples of the alkenyl group in the above alkyl group include those in which a single bond (C-C) between any one carbon atoms is replaced with a double bond (C=C), and the position of the double bond is not limited.

[0017] In the above formula (S2), m and n are each preferably 0, and m and n may be 0 at the same time.

[0018] The aromatic polysulfone preferably has a content of repeating unit S2 of 0.11 mol% or more, more preferably 0.12 mol% or more, and preferably 1.00 mol% or less, and more preferably 0.50 mol% or less, based on the total repeating units constituting the aromatic polysulfone. The content of repeating unit S2 may be 0.10 mol% to 1.00 mol%, 0.10 mol% to 0.50 mol%, 0.11 mol% to 1.50 mol%, 0.11 mol% to 1.00 mol%, 0.11 mol% to 0.50 mol%, 0.12 mol% to 1.50 mol%, 0.12 mol% to 1.00 mol%, or 0.12 mol% to 0.50 mol%.

[0019] The aromatic polysulfone may have other repeating units in addition to the repeating unit S1 and the repeating unit S2. The aromatic polysulfone preferably has only the repeating unit S1 and the repeating unit S2.

[0020] The aromatic polysulfone can be produced by a production method including a step of reacting, in an aprotic polar solvent, monomers containing at least one compound represented by the following formula (S2a), at least one compound represented by the following formula (S2b), and the compound represented by the formula (S1), wherein the content of the compound represented by formula (S1) relative to all monomers is 0.10 mol % or more and less than 1.50 mol %:

[0021] (In formula (S2a), R ５ , R ６, m and n are R in the above formula (S2), ５ , R ６ , m and n)

[0022] (In formula (S2b), R ５ , R ６ , m and n are R in the above formula (S2), ５ , R ６ , m and n are synonymous with each other, and X １ and X ２ each independently represents a halogen atom; １ and X ２ may be the same or different)

[0023] The step of reacting the monomer is preferably carried out using an alkali metal carbonate. The alkali metal carbonate may be a carbonate, which is a normal salt, a bicarbonate (also called a hydrogen carbonate), which is an acidic salt, or a mixture of both. As the carbonate, sodium carbonate or potassium carbonate is preferably used, and as the hydrogen carbonate, sodium bicarbonate or potassium bicarbonate is preferably used.

[0024] Examples of aprotic polar solvents include dimethyl sulfoxide, 1-methyl-2-pyrrolidone, sulfolane (also known as 1,1-dioxothiane), 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, dimethyl sulfone, diethyl sulfone, diisopropyl sulfone, and diphenyl sulfone.

[0025] The polymerization temperature varies depending on the type of aprotic polar solvent used, but is, for example, about 180°C to 300°C.

[0026] The molecular weight of the obtained aromatic polysulfone is evaluated by the reduced viscosity, which can be measured by the following method.

[0027] [Measurement of reduced viscosity] 1 g of aromatic polysulfone is dissolved in N,N-dimethylformamide to a volume of 1 dL (solution concentration: 1 g / dL). The viscosity (η) of the resulting aromatic polysulfone solution is measured at 25°C using an Ostwald-type viscometer.

[0028] In addition, the viscosity (η ０ ) is measured at 25°C using an Ostwald type viscometer. ０ ) to obtain the specific viscosity η ｓｐ = ((η-η ０ ) / η ０ ) is required.

[0029] Specific viscosity η ｓｐ is divided by the solution concentration of the aromatic polysulfone solution to determine the reduced viscosity (unit: dL / g). The reduced viscosity is preferably 0.2 dL / g or more, more preferably 0.3 dL / g or more, and even more preferably 0.35 dL / g or more, and is preferably 1.2 dL / g or less, more preferably 1.0 dL / g or less, more preferably 0.8 dL / g or less, and even more preferably 0.6 dL / g or less. The reduced viscosity may be 0.2 dL / g or more and 1.2 dL / g or less, 0.3 dL / g or more and 1.0 dL / g or less, 0.35 dL / g or more and 0.8 dL / g or less, or 0.35 dL / g or more and 0.6 dL / g or less.

[0030] The aromatic polysulfone described above contains "repeating units derived from the compound represented by formula (S1)," and thus thickening in a high-temperature environment is suppressed.

[0031] The degree of thickening of the aromatic polysulfone in a high-temperature environment is evaluated by measuring the melt viscosity of the aromatic polysulfone and calculating the "melt viscosity ratio" representing the degree of thickening from the obtained value. The melt viscosity of the aromatic polysulfone can be measured by the following method.

[0032] [Melt Viscosity Measurement] The melt viscosity of the aromatic polysulfone is measured using a dynamic viscoelasticity measuring device (e.g., a rheometer CVO model manufactured by Bohlin Instruments) and a value determined from a viscosity curve obtained using parallel plates under the following conditions. As an example, the measurement temperature is set to 400°C, but the measurement temperature can be changed. Using this measurement method, the melt viscosity (A) after a holding time of 5 minutes and the melt viscosity (B) after a holding time of 30 minutes are determined. (Conditions) Measurement temperature: 400°C Strain: 0.05% Frequency: 1 Hz Plate spacing: 0.8 mm Holding time: 30 minutes

[0033] The melt viscosity ratio (melt viscosity (B) / melt viscosity (A)) can be calculated from the measurement results to evaluate the degree of thickening of the aromatic polysulfone at the measurement temperature. When the melt viscosity ratio is 1 or less, it can be evaluated that the aromatic polysulfone does not thicken at the measurement temperature and stable molding is possible at the measurement temperature. When the melt viscosity ratio exceeds 1, it can be evaluated that the aromatic polysulfone thickens at the measurement temperature and stable molding at the measurement temperature may be difficult.

[0034] <<Molded Article>> The aromatic polysulfone described above can be suitably used as a material for a molded article that requires heat resistance.

[0035] Examples of such molded articles include electrical and electronic parts such as connectors, sockets, IC sockets, burn-in sockets, relay parts, coil bobbins, optical pickups, oscillators, printed wiring boards, circuit boards, semiconductor packages, and computer-related parts; parts related to semiconductor manufacturing processes such as IC trays and wafer carriers; parts for home electrical appliances such as VTRs, televisions, irons, air conditioners, stereos, vacuum cleaners, refrigerators, rice cookers, and lighting fixtures; parts for lighting fixtures such as lamp reflectors and lamp holders; parts for audio products such as compact discs, laser discs (registered trademark), and speakers; parts for communication devices such as ferrules for optical cables, telephone parts, facsimile parts, and modems; separation claws or heater holders. copier or printer related parts; mechanical parts such as impellers, fan gears, gears, bearings, or motor parts or cases; automotive parts such as automotive mechanism parts, engine parts, engine room parts, electrical parts, or interior parts; cooking utensils such as microwave cooking pots or heat-resistant tableware; heat insulating or soundproofing materials such as flooring or wall materials, support materials such as beams or pillars, building materials such as roofing materials, or civil engineering and construction materials; parts for aircraft, spacecraft, or space equipment; radiation facility components such as nuclear reactors; marine facility components, cleaning jigs, optical equipment parts, valves, pipes, nozzles, filters, membranes, medical equipment parts or medical materials, sensor parts, sanitary fixtures, sporting goods, leisure goods, or cable ties.

[0036] The molded article can be obtained by mixing aromatic polysulfone with known additives such as fillers and stabilizers, or other resin materials as needed, and melt-molding the mixture. Examples of melt-molding methods include injection molding, blow molding, vacuum molding, and press molding, with injection molding being preferred.

[0037] According to the aromatic polysulfone having the above-mentioned constitution, it is possible to provide an aromatic polysulfone in which the increase in viscosity at high temperatures such as 400°C is suppressed.

[0038] Although the preferred embodiments of the present disclosure have been described above, the present disclosure is not limited to these examples. The combinations and the like shown in the above examples are merely examples, and various modifications can be made based on design requirements and the like within the scope of the present disclosure.

[0039] The present disclosure will be described below with reference to examples, but the present disclosure is not limited to these examples.

[0040] In the present examples, physical properties were measured according to the following descriptions.

[0041] [Measurement of Reduced Viscosity] The reduced viscosity of the aromatic polysulfone was measured according to the description in [Measurement of Reduced Viscosity] above.

[0042] [Melt Viscosity Measurement] The melt viscosity of the aromatic polysulfone was measured according to the above-mentioned [Melt Viscosity Measurement]. The measurement temperature was 400° C. Using this measurement method, the melt viscosity (A) after a holding time of 5 minutes and the melt viscosity (B) after a holding time of 30 minutes were determined.

[0043] In the examples and comparative examples, the following monomers were used: Monomer L: 4,4'-dichlorodiphenyl sulfone Monomer M: 4,4'-dihydroxydiphenyl sulfone Monomer N: trimethylhydroquinone Monomer O: 2,3-dimethylhydroquinone Monomer P: hydroquinone

[0044] Example 1 In a polymerization vessel equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a condenser with a receiver attached to its tip, 65.39 g of Monomer L, 54.92 g of Monomer M, 0.08 g of Monomer N, and 106.70 g of diphenyl sulfone as a polymerization solvent were charged, and the temperature was raised to 180° C. while circulating nitrogen gas through the system. To the obtained solution, 31.62 g of potassium carbonate was added, and the temperature was gradually raised to 290° C., and the reaction was carried out at 290° C. for an additional 3 hours.

[0045] The resulting reaction solution was cooled to room temperature to solidify, and then finely pulverized. The resulting powder was washed with warm water and then with a mixed solvent of acetone and methanol, and further dried by heating at 150°C to obtain a white powder of aromatic polysulfone of Example 1.

[0046] Monomer N corresponds to the "compound represented by formula (S1)" in the present disclosure. The content of repeating units S1 relative to all repeating units of the aromatic polysulfone of Example 1 was 0.13 mol%.

[0047] The reduced viscosity and melt viscosity of the resulting aromatic polysulfone were measured by the above-mentioned measurement methods, and the melt viscosity ratio (melt viscosity (B) / melt viscosity (A)) was calculated from the measurement results.

[0048] [Example 2] Except for changing the charged amounts to 54.79 g of Monomer M, 0.17 g of Monomer N, and 106.63 g of diphenyl sulfone, an aromatic polysulfone of Example 2 was obtained in the same manner as in Example 1. The content of repeating unit S1 relative to all repeating units of the aromatic polysulfone of Example 2 was 0.25 mol%.

[0049] [Example 3] Except for changing the amounts charged to 54.51 g of Monomer M, 0.33 g of Monomer N, and 106.48 g of diphenyl sulfone, the aromatic polysulfone of Example 3 was obtained in the same manner as in Example 1. The content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone of Example 3 was 0.50 mol%.

[0050] Example 4 An aromatic polysulfone of Example 4 was obtained in the same manner as in Example 1, except that the charged amounts were changed to 54.51 g of Monomer M and 106.44 g of diphenyl sulfone, and 0.08 g of Monomer N was changed to 0.30 g of Monomer O.

[0051] Monomer O corresponds to the "compound represented by formula (S1)" in the present disclosure. The content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone of Example 4 was 0.50 mol%.

[0052] [Comparative Example 1] Except for changing the charged amounts to 55.06 g of Monomer M, 0 g of Monomer N, and 106.78 g of diphenyl sulfone, an aromatic polysulfone of Comparative Example 1 was obtained in the same manner as in Example 1. The content of repeating unit S1 relative to all repeating units of the aromatic polysulfone of Comparative Example 1 was 0.00 mol%.

[0053] [Comparative Example 2] Except for changing the charged amounts to 65.26 g of Monomer L, 55.06 g of Monomer M, 0 g of Monomer N, and 106.61 g of diphenyl sulfone, an aromatic polysulfone of Comparative Example 2 was obtained in the same manner as in Example 1. The content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone of Comparative Example 2 was 0.00 mol%.

[0054] [Comparative Example 3] Except for changing the charged amounts to 55.01 g of Monomer M, 0.03 g of Monomer N, and 106.75 g of diphenyl sulfone, an aromatic polysulfone of Comparative Example 3 was obtained in the same manner as in Example 1. The content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone of Comparative Example 3 was 0.05 mol%.

[0055] [Comparative Example 4] Except for changing the charged amounts to 53.41 g of Monomer M, 1.00 g of Monomer N, and 105.90 g of diphenyl sulfone, an aromatic polysulfone of Comparative Example 4 was obtained in the same manner as in Example 1. The content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone of Comparative Example 4 was 1.50 mol%.

[0056] [Comparative Example 5] Except for changing the charged amounts to 49.56 g of Monomer M, 3.35 g of Monomer N, and 103.87 g of diphenyl sulfone, an aromatic polysulfone of Comparative Example 5 was obtained in the same manner as in Example 1. The content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone of Comparative Example 5 was 5.00 mol%.

[0057] When the melt viscosity of the obtained aromatic polysulfone was measured, the melt viscosity increased significantly, so the measurement was stopped midway and it was deemed impossible to measure.

[0058] [Comparative Example 6] Except for changing the charged amounts to 54.51 g of Monomer M and 106.36 g of diphenyl sulfone and changing 0.08 g of Monomer N to 0.24 g of Monomer P, an aromatic polysulfone of Comparative Example 6 was obtained in the same manner as in Example 1. The content of repeating unit S1 relative to all repeating units of the aromatic polysulfone of Comparative Example 6 was 0.00 mol%.

[0059] The results are shown in Table 1 below.

[0060]

[0061] As a result of the evaluation, the aromatic polysulfones of Examples 1 to 4 all had a melt viscosity ratio of 1 or less, and no increase in viscosity was confirmed under the measurement conditions. It can be evaluated that all of the aromatic polysulfones of Examples 1 to 4 can be stably molded at the measurement temperature.

[0062] In contrast, the aromatic polysulfones of Comparative Examples 1 to 3 and 6, in which the content of the compound represented by formula (S1) relative to all repeating units was less than 0.10 mol %, and Comparative Example 4, in which the content was 1.50 mol % or more, had melt viscosity ratios exceeding 1, and an increase in viscosity was confirmed under the measurement conditions. The aromatic polysulfone of Comparative Example 5 was confirmed to have increased in viscosity to the extent that the melt viscosity could not be measured.

[0063] The above results confirm that the present disclosure is useful.

Claims

1. An aromatic polysulfone comprising a repeating unit S1 derived from a compound represented by the following formula (S1) and a repeating unit S2 represented by the following formula (S2), wherein the content of the repeating unit S1 relative to all repeating units of the aromatic polysulfone is 0.10 mol % or more but less than 1.50 mol %. (In formula (S1), R １ , R ２ and R ３ each independently represents a hydrogen atom or a methyl group) (In formula (S2), R ５ and R ６ each independently represents a halogen atom, a phenyl group, an alkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; m and n each independently represent an integer of 0 to 4; R ５ or R ６ If there are multiple, they may be the same or different) 2. The aromatic polysulfone according to claim 1, wherein the content of the repeating unit S1 relative to the total repeating units is 0.10 mol % or more and 0.50 mol % or less.

3. The aromatic polysulfone according to claim 1 or 2, wherein the compound represented by formula (S1) is trimethylhydroquinone or 2,3-dimethylhydroquinone.

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