Polysulfone-based resin composition and process for producing the same

Abstract

Thereby, the polysulfone-based resin composition having high fluidity can simply be obtained at a low cost in a short time. The obtained polysulfone-based resin composition is particularly suitable for a polymer alloy with other thermoplastic resins or thermosetting resins.SOLUTION: The polysulfone-based resin composition comprises (A) a polysulfone-based resin, (B) a hydrophilic resin, and (C) a metal alkoxide. The method for producing the polysulfone-based polymer composition comprises bringing (A1) the polysulfone-based polymer, (B1) the hydrophilic polymer and (C) the metallic alkoxide into contact with each other in the absence of a non-solvent. Further, the polysulfone-based resin composition comprises (A2) a polysulfone-based resin and (B2) a hydrophilic resin, and has a melt viscosity of 1-500 Pa·s measured by using a capillary rheometer under the condition of a shear rate of 1216 / s at a temperature of (A2) the polysulfone-based resin + 5 minutes at a temperature of (B2) the hydrophilic resin + 50 °C.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polysulfone-based resin composition that contributes to a circular economy, and a method for producing the same. [Background technology]

[0002] Polysulfone-based resins, typified by polysulfone, polyethersulfone, polyarylethersulfone, and the like, are amorphous super engineering plastics that have excellent heat resistance, flame retardancy, hydrolysis resistance, and transparency, and are suitable for applications in the automotive, food industry, medical equipment, and other industries.

[0003] In recent years, there has been an increasing demand for recycling thermoplastic resins in order to realize a circular economy. However, because polysulfone-based resins are amorphous and have a high glass transition temperature, when they are melt-kneaded in an extruder for material recycling, they have a high melt viscosity, resulting in high temperatures and torque, which places a heavy load on melt-kneading machines such as extruders.

[0004] In particular, process waste materials of hollow fiber membranes made of polysulfone resins used in artificial kidneys and the like (see, for example, Patent Document 1) have been attracting attention as a promising recycling resource due to their stable quality and availability. However, these materials are designed to have a high viscosity to improve spinnability, making the above-mentioned problems even more pronounced.

[0005] Given this background, there is a demand for a technology that allows for material recycling of polysulfone-based resins at low cost and in a simple manner while reducing their viscosity.

[0006] To address these issues, a method has been proposed in which the viscosity of polysulfone-based resins is reduced by depolymerization (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-187768 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-1446 Summary of the Invention [Problem to be solved by the invention]

[0008] However, the method described in Patent Document 2 involves depolymerization in an aprotic solvent over several hours, and therefore cannot be applied to low-cost, short-time methods such as melt-kneading using an extruder. [Means for solving the problem]

[0009] Therefore, the present inventors conducted extensive research to solve the above-mentioned problems and discovered that adding a hydrophilic resin and a metal alkoxide to a polysulfone-based resin makes it possible to easily reduce the viscosity of the polysulfone-based resin in a non-solvent environment while recycling the material, thereby arriving at the present invention.

[0010] That is, the present invention has the following configuration. 1. A polysulfone-based resin composition comprising (A1) a polysulfone-based resin, (B1) a hydrophilic resin, and (C) a metal alkoxide; 2. The polysulfone-based resin composition according to item 1, wherein the polysulfone-based resin (A1) is at least one selected from the group consisting of polysulfone, polyethersulfone, and polyarylethersulfone; 3. The polysulfone-based resin composition according to item 1 or 2, wherein the hydrophilic resin (B1) is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol; 4. The polysulfone-based resin composition according to any one of items 1 to 3, wherein the metal species of the (C) metal alkoxide is an alkali metal. 5. A method for producing a polysulfone-based resin composition, comprising contacting a resin composition comprising (A1) a polysulfone-based resin, (B1) a hydrophilic resin, and (C) a metal alkoxide in the presence of a non-solvent; 6. The method for producing a polysulfone-based resin composition according to item 5, wherein the polysulfone-based resin (A1) is at least one selected from the group consisting of polysulfone, polyethersulfone, and polyallyl ether sulfone. 7. The method for producing a polysulfone-based resin composition according to item 5 or 6, wherein the polysulfone-based resin (A1) is derived from a hollow fiber membrane. 8. The method for producing a polysulfone-based resin composition according to any one of items 5 to 7, wherein (B1) the hydrophilic resin is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol. 9. The method for producing a polysulfone-based resin composition according to any one of items 5 to 8, wherein the metal species of the (C) metal alkoxide is an alkali metal. 10. A polysulfone-based resin composition comprising (A2) a polysulfone-based resin and (B2) a hydrophilic resin, the polysulfone-based resin composition having a melt viscosity of 1 to 500 Pa·s, measured using a capillary rheometer at a temperature of 150°C above the glass transition temperature of (A2) the polysulfone-based resin, for 5 minutes, and then at the same temperature and a shear rate of 1216 / s. 11. The polysulfone-based resin composition according to item 10, wherein the weight-average molecular weight of the polysulfone-based resin (A2) determined using gel permeation chromatography (GPC) in terms of polystyrene is 10,000 to 60,000. 12. The polysulfone-based resin composition according to item 10 or 11, wherein the (A2) polysulfone-based resin is at least one selected from the group consisting of polysulfone, polyethersulfone, and polyallyl ether sulfone. 13. The polysulfone-based resin composition according to any one of items 10 to 12, further containing a metal. 14. The polysulfone-based resin composition according to item 13, wherein the metal contained is an alkali metal. 15. The polysulfone resin composition according to any one of items 10 to 14, wherein the hydrophilic resin (B2) is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol. [Effects of the Invention]

[0011] According to the present invention, a polysulfone-based resin composition having a reduced viscosity can be obtained simply and inexpensively in a short time. The obtained polysulfone-based resin composition is particularly suitable for polymer alloys with other thermoplastic resins or thermosetting resins, and for composite materials containing fibrous fillers. DETAILED DESCRIPTION OF THE INVENTION

[0012] The polysulfone-based resin (A1) used in the present invention is a polymer having an aromatic ring, a sulfonyl group, and an ether group in the main chain. Specific examples include polysulfone, polyethersulfone, and polyallyl ether sulfone. Polysulfone and polyethersulfone, which are used for hollow fiber membranes in artificial kidneys, are particularly preferred.

[0013] Specific examples of such polysulfone-based resins include "Udel" (registered trademark) P-1700 and P-3500 manufactured by Solvay, and "Ultrason" (registered trademark) S3010, S6010, and E6020P manufactured by BASF.

[0014] The (A1) polysulfone-based resin may be used alone or in combination of two or more kinds.

[0015] Such polysulfone resins are generally amorphous super engineering plastics with high glass transition temperatures, and therefore have extremely high melt viscosities of over 500 Pa·s and up to 2000 Pa·s. As a result, recycling them using a melt mixer such as an extruder requires high temperatures and torque, placing a heavy load on the equipment.

[0016] The melt viscosity of the polysulfone-based resin (A1) in the present invention, and the polysulfone-based resin (A2) and polysulfone-based resin composition described below is a value measured using a capillary rheometer (for example, "Capilograph" (registered trademark) manufactured by Toyo Seiki Seisaku-sho) at a shear rate of 1216 / s at a test temperature of Tg+150°C of the polysulfone-based resin (A1) or the polysulfone-based resin (A2) after allowing the resin to dwell for 5 minutes at the same temperature.

[0017] Furthermore, in order to ensure the toughness of the resin itself, such polysulfone resins are usually designed to have a weight-average molecular weight of more than 60,000 and not more than 100,000. Therefore, when recycled using a melt kneader such as an extruder, high temperatures and torque are required, which places a heavy load on the equipment, which is a problem.

[0018] The weight average molecular weights of the (A1) polysulfone-based resin in the present invention, and the (A2) polysulfone-based resin and polysulfone-based resin composition described below are values ​​measured in terms of polystyrene using gel permeation chromatography (GPC), which is a type of size exclusion chromatography (SEC).

[0019] From the viewpoint of circular economy, the polysulfone resin (A1) used in the present invention is preferably a molded article that has been recovered after use in the market as process by-products or products.

[0020] The process waste is, for example, process waste generated in a process for producing a thermoplastic resin and a process for molding a molded article from a thermoplastic resin, a process for producing a thermoplastic resin composition and a process for molding a molded article from a thermoplastic resin composition, and includes, for example, crushed process waste generated in an extrusion molding process such as a blow molding process, a membrane forming process, or a spinning process, and crushed sprues, runners, and the like recovered during molding in an injection molding process, etc. Among these, process waste derived from the spinning process is preferred from the viewpoint of supply and quality of recycled materials, and process waste derived from a process for producing hollow fiber membranes for artificial kidneys is preferred because, if the hydrophilic resin (B1) blended in the process remains, the addition of the hydrophilic resin (B1) can be omitted during material recycling.

[0021] From the perspective of a circular economy, molded products that have been collected after use in the market are more preferable, but in this case, performance tends to be reduced due to components that adhere during use in the market. Therefore, it is preferable to wash with a solvent to remove the adhered components. Examples of solvents include water and organic solvents. Water is preferred from the perspective of cost, and organic solvents are preferred from the perspective of efficiently removing contaminant components. Multiple solvents may be used in combination.

[0022] (A1) When the polysulfone-based resin is a process offcut or a molded product recovered after use in the market, it is preferable that traceability that proves its origin is ensured, which may be certification by a certification body or traceability using a blockchain system.

[0023] The hydrophilic resin (B1) used in the present invention is a resin that is soluble in water or ethanol, and preferably has a solubility of 0.1 g / mL or more in these.

[0024] Specific examples of the (B1) hydrophilic resin include polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, and copolymers thereof. Examples of copolymers include, but are not limited to, copolymers of vinylpyrrolidone with a component selected from vinyl acetate, vinyl propionate, and vinyl butanoate. Among these, from the viewpoint of compatibility with the (A1) polysulfone-based resin, it is preferable that the molecular weight of the (B1) hydrophilic resin is similar to that of the (A1) polysulfone-based resin. From the viewpoint of compatibility with the (C) metal alkoxide, polyvinylpyrrolidone or a copolymer thereof is more preferable.

[0025] The (C) metal alkoxide used in the present invention is a salt of a metal ion and an aliphatic or aromatic alkoxide. The metal species is preferably an alkali metal or alkaline earth metal, and more preferably a metal with low electronegativity to achieve excellent reactivity. From the standpoints of availability and economy, sodium or potassium is more preferred, with potassium being more preferred. The valence of the (C) metal alkoxide is preferably monovalent or divalent. Using a monovalent metal alkoxide can inactivate the terminals of the polysulfone-based resin in the polysulfone-based resin composition, improving retention stability. Using a divalent metal alkoxide results in excellent terminal reactivity, resulting in a polysulfone-based resin composition suitable for polymer alloys; therefore, it is desirable to select the valence according to the purpose. The (C) metal alkoxide is preferably an aliphatic or aromatic metal alkoxide having 1 to 30 carbon atoms. Specific examples of the (C) metal alkoxide include sodium phenoxide, sodium methoxide, sodium ethoxide, potassium phenoxide, potassium methoxide, potassium ethoxide, and potassium t-butoxide. Furthermore, from the viewpoint of heat resistance, it is preferable that the compound has a bisphenol skeleton, and specific examples include alkali metal salts or alkaline earth metal salts of bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, and bisphenol PH. Metal salts of bisphenol A or bisphenol S, which are the basic skeletons of polysulfone-based resins, are preferred because they allow a polysulfone-based resin composition to be obtained without impairing the properties of the (A1) polysulfone.

[0026] The present invention relates to a polysulfone-based resin composition comprising the above-described (A1) polysulfone-based resin, (B1) hydrophilic resin, and (C) metal alkoxide, and a method for producing the polysulfone-based resin composition by contacting the resin compositions in the presence of a non-solvent to reduce the viscosity of the (A1) polysulfone-based resin.

[0027] As described in Patent Document 2, it is common to increase the contact frequency of the polysulfone resin (A1) and the metal alkoxide (C) in an aprotic solvent and carry out depolymerization over several hours. However, the present inventors have found that by utilizing the property of the hydrophilic resin (B1) that the polysulfone resin (A1) and the metal alkoxide (C) are highly compatible with each other, the contact frequency of the polysulfone resin (A1) and the alkali metal alkoxide (C) can be increased even in a non-solvent environment, and depolymerization can proceed efficiently in a short time.

[0028] The amount of the hydrophilic resin (B1) blended is preferably 0.1 to 100 parts by mass per 100 parts by mass of the polysulfone resin (A1), with the upper limit being more preferably 50 parts by mass or less, and particularly preferably 30 parts by mass or less, from the viewpoint of expressing the properties of the polysulfone resin, and even more preferably 10 parts by mass or less, and most preferably 5 parts by mass or less, from the viewpoint of suppressing gas generation during processing. Also, the lower limit is more preferably 0.5 parts by mass or more, and particularly preferably 1 part by mass or more, from the viewpoint of efficiently lowering the viscosity of the polysulfone resin composition.

[0029] The (B1) hydrophilic resin may be intentionally blended with the (A1) polysulfone-based resin, or, when the (A1) polysulfone-based resin is a molded article recovered after use as a process remnant or a product on the market, the (B1) hydrophilic resin may be blended by being mixed into or remaining in the polysulfone-based resin during the manufacturing process or use.

[0030] The amount of (C) metal alkoxide is preferably 0.1 to 20 mol% per mole of (A1) polysulfone resin, more preferably 15 mol% or less from the viewpoint of expressing the properties of the polysulfone resin, particularly preferably 10 mol% or less, even more preferably 5 mol% or less from the viewpoint of ensuring the toughness of the polysulfone resin, and most preferably 3 mol% or less. Also, from the viewpoint of efficiently lowering the viscosity of the polysulfone resin composition, it is more preferably 0.5 mol% or more, particularly preferably 1 mol% or more, and even more preferably 3 mol% or more.

[0031] The metal alkoxide (C) may be produced in situ by blending an alcohol and a metal compound and bringing them into contact with the polysulfone resin (A1) in the absence of a solvent.

[0032] In the present invention, 1 mole of the (A1) polysulfone-based resin is a value calculated by dividing the molecular weight (g / mol) of the unit structure of the (A1) polysulfone-based resin by the mass (g) of the (A1) polysulfone-based resin.

[0033] Contact in a non-solvent state can be achieved by any method as long as the components come into contact and the reaction proceeds, but it is preferable to increase the contact frequency by heating to a molten state. Representative examples of heating include batchwise supply of raw materials to a known autoclave and melt-kneading, or continuous supply of raw materials to a known melt-kneader such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, or a mixing roll, and melt-kneading so that the resin temperature is 100°C to 200°C above the glass transition temperature of the (A) polysulfone-based resin. A continuous method is preferred from the perspective of low-cost and simple viscosity reduction. Melt-kneading using a twin-screw extruder is preferred from the perspective of efficient viscosity reduction. The resin temperature here is a value obtained by directly measuring the temperature of the resin discharged from the device.

[0034] In a preferred embodiment, the polysulfone-based resin composition of the present invention, which is composed of the polysulfone-based resin (A1), the hydrophilic resin (B1), and the metal alkoxide (C), is blended with another thermoplastic resin described below and brought into contact with the other thermoplastic resins in the presence of a non-solvent, thereby producing a polysulfone-based resin composition in which a polymer alloy is formed while the viscosity of the polysulfone-based resin (A1) is reduced.

[0035] In addition, in a preferred embodiment, the polysulfone-based resin composition of the present invention, which is composed of the polysulfone-based resin (A1), the hydrophilic resin (B1), and the metal alkoxide (C), is blended with various additives described below and brought into contact with each other in the presence of a non-solvent, thereby producing a polysulfone-based resin composition in which the viscosity of the polysulfone-based resin (A1) is reduced and various functions are imparted to the polysulfone-based resin.

[0036] Another embodiment of the polysulfone-based resin composition of the present invention comprises (A2) a polysulfone-based resin and (B2) a hydrophilic resin, and is characterized by a melt viscosity of 1 to 500 Pa·s. From the viewpoint of application to injection molding, where fluidity is required, the upper limit is preferably 450 Pa·s or less, more preferably 400 Pa·s or less. From the viewpoint of suppressing breakage of a fibrous filler and improving mechanical properties when blending with a fibrous filler to obtain a composite material, the upper limit is particularly preferably 350 Pa·s or less, and even more preferably 300 Pa·s or less. Furthermore, from the viewpoint of reducing the viscosity ratio with other polymers and improving dispersibility when alloyed with other polymers, the upper limit is more preferably 250 Pa·s or less, and most preferably 200 Pa·s or less. Furthermore, from the viewpoint of expressing the properties of the polysulfone-based resin, the lower limit is preferably 10 Pa·s or more, more preferably 50 Pa·s or more.

[0037] In order to obtain a polysulfone-based resin composition having such a melt viscosity, it is preferable to adjust the depolymerization reaction by changing the melt viscosity of the (A1) polysulfone-based resin or by changing the amount or type of the (C) metal alkoxide.

[0038] The polysulfone resin (A2) in the polysulfone resin composition of another embodiment of the present invention preferably has the same main chain structure as the polysulfone resin (A1).

[0039] The weight-average molecular weight of the (A2) polysulfone resin in the polysulfone resin composition is preferably 10,000 to 60,000. From the viewpoint of application to injection molding, which requires fluidity, the upper limit is preferably 55,000 or less, more preferably 50,000 or less. From the viewpoint of suppressing breakage of a fibrous filler and improving mechanical properties when blending a fibrous filler to obtain a composite material, the upper limit is particularly preferably 45,000 or less, and even more preferably 40,000 or less. From the viewpoint of reducing the viscosity ratio with other polymers and improving dispersibility when alloyed with other polymers, the upper limit is even more preferably 35,000 or less. From the viewpoint of expressing the properties of the polysulfone resin, the lower limit is preferably 15,000 or more, more preferably 20,000 or more, and especially preferably 25,000 or more.

[0040] In order to obtain a polysulfone-based resin composition having such a weight-average molecular weight, it is preferable to adjust the depolymerization reaction by changing the amount or type of (C) metal alkoxide.

[0041] In another embodiment of the present invention, the polysulfone-based resin composition preferably contains a metal, and more preferably an alkali metal, from the viewpoint of improving dispersibility when alloyed with other polymers. The metal content is preferably 0.001 to 1.0% based on the total mass of the polysulfone-based resin composition. The upper limit is more preferably 0.7% or less, particularly preferably 0.5% or less. Furthermore, when the polysulfone-based resin composition of the present invention is used in an application where ion elution is a problem, it is also preferable to neutralize the metal salt with an acid and then remove the metal component.

[0042] The hydrophilic resin (B2) in the polysulfone-based resin composition according to another embodiment of the present invention preferably has the same main chain structure as the hydrophilic resin (B1). However, there is no problem even if some of the components are modified by contact in a non-solvent.

[0043] The amount of the hydrophilic resin (B2) in the polysulfone-based resin composition according to another embodiment of the present invention is preferably 0.1 to 100 parts by mass per 100 parts by mass of the polysulfone-based resin (A2), with the upper limit being more preferably 50 parts by mass or less, and particularly preferably 30 parts by mass or less, from the viewpoint of enabling the properties of the polysulfone-based resin to be expressed, and with the upper limit being particularly preferably 10 parts by mass or less, and most preferably 5 parts by mass or less, from the viewpoint of suppressing gas generation during processing. Furthermore, the lower limit is more preferably 0.5 parts by mass or more, and particularly preferably 1 part by mass or more, from the viewpoint of efficiently lowering the viscosity of the polysulfone-based resin composition.

[0044] The polysulfone-based resin composition of the present invention and the polysulfone-based resin composition of another embodiment of the present invention may both be blended with additives to the extent that the effects of the invention are not impaired. Examples of additives include fibrous fillers such as glass fiber, carbon fiber, carbon nanotube, carbon nanohorn, potassium titanate whisker, zinc oxide whisker, calcium carbonate whisker, wollastonite whisker, and aluminum borate whisker, as well as aramid fiber, alumina fiber, silicon carbide fiber, ceramic fiber, asbestos fiber, gypsum fiber, and metal fiber, which can be blended to improve mechanical strength. From the viewpoints of performance and cost, glass fiber and carbon fiber are particularly preferred. Other examples of additives include non-fibrous fillers such as fullerene, talc, wollastonite, zeolite, sericite, mica, kaolin, clay, pyrophyllite, silica, bentonite, asbestos, silicates such as alumina silicate, metal compounds such as silicon oxide, magnesium oxide, alumina, zirconium oxide, titanium oxide, and iron oxide, carbonates such as calcium carbonate, magnesium carbonate, and dolomite, sulfates such as calcium sulfate and barium sulfate, hydroxides such as calcium hydroxide, magnesium hydroxide, and aluminum hydroxide, glass beads, glass flakes, glass powder, ceramic beads, boron nitride, silicon carbide, carbon black, silica, and graphite, which can be blended to impart properties. From the viewpoints of electrical properties, corrosion prevention, lubricating properties, and imparting conductivity, magnesium hydroxide, calcium carbonate, silica, and carbon black are preferred. Other examples of additives include phenolic antioxidants, phosphorus-based antioxidants, sulfur-based antioxidants, plasticizers such as organophosphorus compounds, organophosphorus compounds, Montan acid waxes, metal soaps such as lithium stearate and aluminum stearate, mold release agents such as ethylenediamine-stearic acid-sebacic acid polycondensates and silicone compounds, and other common additives such as water, lubricants, UV inhibitors, colorants, and foaming agents. These additives are preferably blended in amounts of 0.01 to 40 parts by weight per 100 parts by weight of the polysulfone resin, provided that the blend does not detract from the scope of the invention. Among these, the addition of a fibrous filler is particularly preferred because the polysulfone resin composition of another embodiment of the present invention has a low melt viscosity and can suppress breakage of the fibrous filler.

[0045] The polysulfone-based resin composition of another embodiment of the present invention has a low melt viscosity and is suitable for polymer alloys with other thermoplastic resins or thermosetting resins. Furthermore, the hydrophilic resin (B2) contained in the polysulfone-based resin composition tends to reduce the interfacial tension with other polymers, making it particularly suitable for polymer alloys with other thermoplastic resins or thermosetting resins. Specific examples of other thermoplastic resins include vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, polyvinyl alcohol, polyvinyl acetal, polystyrene, AS resin, ABS resin, methacrylic resin, polyethylene, polypropylene, olefin copolymers, polyamide, polyacetal, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, liquid crystal polyester resin, polyphenylene ether, polyphenylene sulfide, polyarylate, polysulfone, polyether sulfone, polyether imide, polyether ether ketone, fluororesin, thermoplastic elastomer, and copolymers thereof, as well as polymer alloys composed of multiple resins selected from these. Among these, polymer alloys with super engineering plastics having a similar processing temperature to polysulfone-based resins are preferred, crystalline super engineering plastics are more preferred from the viewpoint of complementary properties, and polyphenylene sulfide, which has relatively good compatibility, is particularly preferred.

[0046] Like known polysulfone-based resins, both the polysulfone-based resin composition of the present invention and the polysulfone-based resin composition of another embodiment of the present invention can be applied to various molding methods, such as extrusion molding, injection molding, blow molding, calendar molding, compression molding, vacuum molding, foam molding, blow molding, and rotational molding. In particular, the polysulfone-based resin composition is suitable for injection molding due to its low viscosity.

[0047] Molded articles obtained by molding the polysulfone-based resin composition of the present invention and other embodiments of the polysulfone-based resin composition of the present invention are applicable to many known applications recognized by patents, similar to known polysulfone-based resins. Examples of known applications include medical components such as hollow fiber membranes for dialyzers and surgical instrument housings, insulating components for electronic devices, automotive fuel system components, and water treatment membrane materials. The low-viscosity polysulfone-based resin obtained by the present invention exhibits excellent dimensional stability even in high-temperature water and humid and hot environments, and also exhibits excellent moldability in water-related components with complex flow path structures. Therefore, it is suitable for use in, for example, valve housings for water purifiers and dispenser nozzle components. Furthermore, while reduced flowability is a problem particularly in polysulfone-based resin compositions highly loaded with thermally conductive fillers, the low-viscosity polysulfone-based resin obtained by the present invention achieves excellent mold filling properties and uniform filler dispersion, making it suitable for use in thin-walled thermal management components such as piping components for automotive battery cooling systems. [Example]

[0048] The effects of the present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0049] (1) Film preparation Polysulfone resin and a spacer (approximately 0.3 mm aluminum plate) were sandwiched between polyimide film ("Kapton" (registered trademark) manufactured by DuPont-Toray Co., Ltd.). The polyimide film was then sandwiched between a press mold heated to the glass transition temperature of the polysulfone resin + 150°C, and pressure was applied for 1 minute. After allowing the sample to dwell under pressure for 1 minute, the polyimide film was removed and immersed in the prepared water to rapidly cool, yielding a polysulfone resin film.

[0050] (2) Measurement of glass transition temperature (Tg) The polysulfone resin film (thickness: 0.3 mm) prepared by the above method was heated from 50°C to 340°C at a rate of 20°C / min using a differential scanning calorimeter (DSC7 manufactured by PerkinElmer). The inflection point of the baseline shift detected during this heating was taken as the glass transition temperature.

[0051] (3) Melt viscosity The raw materials, polysulfone-based resins, and polysulfone-based resin compositions obtained in each of the Examples and Comparative Examples were subjected to measurement of melt viscosity using a capillary rheometer, "Capillograph" (registered trademark) manufactured by Toyo Seiki Seisaku-sho, Ltd., under conditions of a shear rate of 1216 / s, a capillary length of 10 mm, and a capillary diameter of 1 mm, after retention for 5 minutes at a temperature of the glass transition temperature of the polysulfone-based resin + 150°C.

[0052] (4) Quantitative determination of metal content For the polysulfone-based resin compositions obtained in each Example and Comparative Example, samples were weighed into quartz crucibles, incinerated in an electric furnace, dissolved in concentrated nitric acid, and then made up to a constant volume with dilute nitric acid. The resulting constant-volume solutions were analyzed using ICP mass spectrometry (apparatus: Agilent 4500) and ICP atomic emission spectrometry (apparatus: PerkinElmer Optima 4300DV).

[0053] (5) Molecular weight measurement The molecular weights of the polysulfone resins (A2) obtained in each of the Examples and Comparative Examples were measured by gel permeation chromatography (GPC), a type of size exclusion chromatography (SEC), to determine the weight average molecular weight (Mw), number average molecular weight (Mn), and polydispersity (Mw / Mn) in terms of polystyrene. The GPC measurement conditions are as follows: Apparatus: "Shodex" (registered trademark) GPC-101 manufactured by Resonac Co., Ltd. Column name: "Shodex" (registered trademark) KF806L manufactured by Resonac Co., Ltd. Eluent: THF Sample concentration: 1mg / ml Detector: Differential refractive index detector Column temperature: 40℃ Detector temperature: 35℃ Flow rate: 1.0mL / min.

[0054] (6) Raw materials (A1-1) The polysulfone resin used was "Udel" (registered trademark) P3500 manufactured by Solvay. The Tg was 190°C, the melt viscosity at 340°C was 690 Pa·s, and the hydrophilic resin content was 0%.

[0055] (A1-2) Process waste materials of hollow fiber membranes produced using (A1-1) polysulfone resin were collected according to the method described in Patent Document 1 (JP 2006-187768 A). The Tg of the obtained polysulfone resin was 190°C, the melt viscosity at 340°C was 580 Pa s, and the content of the hydrophilic resin polyvinylpyrrolidone was approximately 2% as a result of elemental analysis.

[0056] (A1-3) Hollow fiber membranes were produced using polysulfone resin (A1-1) in the same manner as in (A1-2), except that the amount of polyvinylpyrrolidone added during hollow fiber membrane production was increased compared to (A1-2). Process waste from hollow fiber membranes was collected in accordance with the method described in Patent Document 1 (JP 2006-187768 A). The resulting polysulfone resin had a Tg of 190°C, a melt viscosity of 490 Pa s at 340°C, and a polyvinylpyrrolidone content of approximately 4% as a hydrophilic resin, as determined by elemental analysis.

[0057] (A1-4) Process waste from hollow fiber membranes manufactured using polyethersulfone resin was collected. The Tg of the resulting polyethersulfone resin was 210°C, its melt viscosity at 360°C was 800 Pa·s, and the content of the hydrophilic resin polyvinylpyrrolidone was approximately 2% based on elemental analysis.

[0058] (B1-1) Polyvinylpyrrolidone (Polyvinylpyrrolidone K90, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the hydrophilic resin. The weight-average molecular weight of K90 was measured by gel permeation chromatography and found to be 360,000.

[0059] (B1-2) Polyethylene glycol (PEG20000, manufactured by Sanyo Chemical Industries, Ltd.) was used as the hydrophilic resin.

[0060] (B1-3) Polyvinyl alcohol (Mobiflex C17, manufactured by Kuraray Co., Ltd.) was used as the hydrophilic resin.

[0061] (B1-4) Polyvinylpyrrolidone (Polyvinylpyrrolidone K30, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the hydrophilic resin. The weight-average molecular weight of K30 was measured by gel permeation chromatography and found to be 40,000.

[0062] (C-1) Metal alkoxide bisphenol A disodium salt A 100 ml recovery flask was charged with 40 g of water, 0.96 g (0.02 mol) of sodium hydroxide, and 2.51 g (0.01 mol) of bisphenol A (Tokyo Chemical Industry Co., Ltd.), and the mixture was mixed and stirred at room temperature and pressure using a stirrer. After the bisphenol A was completely dissolved, the water in the sample was evaporated using an evaporator. The resulting sample was then vacuum dried overnight at 60°C to obtain bisphenol A disodium salt.

[0063] (C-2) Metal alkoxide bisphenol A dipotassium salt A 100 ml recovery flask was charged with 40 g of water, 1.45 g (0.02 mol) of potassium hydroxide, and 2.51 g (0.01 mol) of bisphenol A (Tokyo Chemical Industry Co., Ltd.), and the mixture was mixed and stirred at 50°C using a stirrer. After the bisphenol A was completely dissolved, the water in the sample was evaporated using an evaporator. The resulting sample was then vacuum dried overnight at 60°C to obtain bisphenol A dipotassium salt.

[0064] (C-3) Metal alkoxide bisphenol A dilithium salt A 100 ml recovery flask was charged with 40 g of water, 0.53 g (0.02 mol) of lithium hydroxide, and 2.51 g (0.01 mol) of bisphenol A (Tokyo Chemical Industry Co., Ltd.), and the mixture was mixed and stirred at 50°C using a stirrer. After the bisphenol A was completely dissolved, the water in the sample was evaporated using an evaporator. The resulting sample was then vacuum dried overnight at 60°C to obtain bisphenol A dilithium salt.

[0065] (C-4) Metal alkoxide bisphenol S disodium salt A 100 ml recovery flask was charged with 40 g of water, 0.80 g (0.02 mol) of sodium hydroxide, and 2.50 g (0.01 mol) of bisphenol S (Tokyo Chemical Industry Co., Ltd.), and the mixture was mixed and stirred at 50°C using a stirrer. After the bisphenol S was completely dissolved, the water in the sample was evaporated using an evaporator. The resulting sample was then vacuum dried overnight at 60°C to obtain bisphenol S disodium salt.

[0066] (C-5) 4-α-cumylphenol potassium salt, a metal alkoxide A 100 ml recovery flask was charged with 40 g of water, 0.66 g (0.01 mol) of potassium hydroxide, and 2.12 g (0.01 mol) of 4-α-cumylphenol (Tokyo Chemical Industry Co., Ltd.), and the contents were mixed and stirred at 50°C using a stirrer. After 4-α-cumylphenol was completely dissolved, the water in the sample was evaporated using an evaporator. The resulting sample was then vacuum dried overnight at 60°C to obtain 4-α-cumylphenol potassium salt.

[0067] (D-1) Compounds other than metal alkoxides As a compound other than the metal alkoxide, bisphenol A (manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0068] [Reference Example 1, Examples 1 to 5, Comparative Examples 1 and 2] The raw materials were dry-blended in the proportions shown in Table 1. The raw material blend was then fed into a ThermoFisher "HAAKE" MiniLab twin-screw extruder and melt-kneaded at a cylinder temperature of 340°C and a screw rotation speed of 200 rpm. The torque was measured after 2 minutes of kneading, and the extruded product was discharged to obtain a polysulfone-based resin composition. The resulting polysulfone-based resin composition was then subjected to the analyses described in (3) to (5) above.

[0069] [Table 1]

[0070] These comparisons revealed that the torque during melt-kneading, melt viscosity, and molecular weight of the polysulfone resin were significantly reduced only when the three components (A1) polysulfone resin, (B1) hydrophilic resin, and (C) metal alkoxide were simultaneously contained. Furthermore, as shown in Examples 2 and 3, it was also found that the torque during melt-kneading, melt viscosity, and molecular weight of the polysulfone resin were significantly reduced even when polyethylene glycol or polyvinyl alcohol was added as the hydrophilic resin (B1). Furthermore, a comparison between Examples 1 and 4 revealed that the melt viscosity and molecular weight of the polysulfone resin were more significantly reduced by using polyvinylpyrrolidone K30, which has a molecular weight similar to that of the polysulfone resin (A1).

[0071] It is presumed that the high compatibility between the (A1) polysulfone resin and the (B1) hydrophilic resin, and the high compatibility between the (B1) hydrophilic resin and the (C) metal alkoxide, increased the frequency of contact between the (A1) polysulfone resin and the (C) metal alkoxide, resulting in efficient depolymerization in a short time even in a non-solvent environment.

[0072] [Reference Examples 2 to 3, Examples 6 to 13, Comparative Example 3] The same procedure as in Example 1 was carried out, except that the raw materials were dry-blended in the proportions shown in Table 2. The parts by mass of the (B1) hydrophilic resin in Table 2 are values ​​calculated from the content of polyvinylpyrrolidone already contained in the (A1) polysulfone-based resin, and no separate (B1) hydrophilic resin was added.

[0073] [Table 2]

[0074] These comparisons revealed that even when the (A1) polysulfone-based resin was derived from process waste materials for hollow fiber membranes and contained the (B1) hydrophilic resin derived from the process, adding the (C) metal alkoxide reduced the torque and melt viscosity during melt-kneading. Furthermore, comparisons of Examples 6, 9, and 10 revealed that changing the metal species of the (C) metal alkoxide to one with a lower electronegativity more significantly reduced the melt viscosity and molecular weight of the polysulfone-based resin. Thus, process waste materials for hollow fiber membranes contain the hydrophilic resin derived from the process, making them suitable for achieving the effects of the present invention.

[0075] [Reference Example 4, Example 14] The same procedure as in Example 1 was carried out, except that the raw materials were dry-blended in the proportions shown in Table 3. The parts by mass of the hydrophilic resin (B1) in Table 3 is the value calculated from the content of polyvinylpyrrolidone that had been previously contained in the polyethersulfone.

[0076] [Table 3]

[0077] From these comparisons, it was found that the same effect was achieved even when the polysulfone resin (A1) was polyethersulfone.

Claims

1. A polysulfone-based resin composition comprising (A1) a polysulfone-based resin, (B1) a hydrophilic resin, and (C) a metal alkoxide.

2. 2. The polysulfone-based resin composition according to claim 1, wherein the polysulfone-based resin (A1) is at least one selected from the group consisting of polysulfone, polyethersulfone, and polyallyl ether sulfone.

3. 3. The polysulfone-based resin composition according to claim 1, wherein the hydrophilic resin (B1) is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

4. 3. The polysulfone-based resin composition according to claim 1, wherein the metal species of the metal alkoxide (C) is an alkali metal.

5. A method for producing a polysulfone-based resin composition, comprising contacting a resin composition comprising (A1) a polysulfone-based resin, (B1) a hydrophilic resin, and (C) a metal alkoxide in the absence of a solvent.

6. 6. The method for producing a polysulfone-based resin composition according to claim 5, wherein the polysulfone-based resin (A1) is at least one selected from the group consisting of polysulfone, polyethersulfone, and polyallyl ether sulfone.

7. The method for producing a polysulfone-based resin composition according to claim 5 or 6, wherein the polysulfone-based resin (A1) is derived from a hollow fiber membrane.

8. 7. The method for producing a polysulfone-based resin composition according to claim 5, wherein the hydrophilic resin (B1) is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

9. 7. The method for producing a polysulfone-based resin composition according to claim 5, wherein the metal species of the metal alkoxide (C) is an alkali metal.

10. A polysulfone-based resin composition comprising (A2) a polysulfone-based resin and (B2) a hydrophilic resin, the polysulfone-based resin composition having a melt viscosity of 1 to 500 Pa s, as determined using a capillary rheometer at a temperature that is 150°C higher than the glass transition temperature of the polysulfone-based resin (A2) and then at the same temperature and a shear rate of 1216 / s after 5 minutes of residence.

11. 11. The polysulfone-based resin composition according to claim 10, wherein the weight-average molecular weight of the polysulfone-based resin (A2) determined by gel permeation chromatography (GPC) in terms of polystyrene is 10,000 to 60,000.

12. 12. The polysulfone-based resin composition according to claim 10, wherein the polysulfone-based resin (A2) is at least one selected from the group consisting of polysulfone, polyethersulfone, and polyallyl ether sulfone.

13. The polysulfone resin composition according to claim 10 or 11, further comprising a metal.

14. 14. The polysulfone resin composition according to claim 13, wherein the metal contained is an alkali metal.

15. 12. The polysulfone-based resin composition according to claim 10, wherein the hydrophilic resin (B2) is at least one selected from the group consisting of polyvinylpyrrolidone, polyethylene glycol, and polyvinyl alcohol.

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