Polyphenylene ether fibers, nonwoven fabric, and method for producing polyphenylene ether fibers

Abstract

The purpose of the present invention is to provide: PPE fibers to which an oil containing high heat-resistant silicone is applied and which have high elongation; a nonwoven fabric containing the PPE fibers; and a method for producing the PPE fibers. The present invention relates to polyphenylene ether fibers containing a polyphenylene ether component, wherein an oil containing high heat-resistant silicone is applied to the polyphenylene ether fibers, the application amount of the oil containing the high heat-resistant silicone is 0.012-0.110 mass% relative to the mass of the polyphenylene ether fibers, and the elongation of the polyphenylene ether fibers is 100% or more.

Description

Polyphenylene ether fibers, nonwoven fabrics, and methods for producing polyphenylene ether fibers

[0001] The present invention relates to polyphenylene ether fibers, nonwoven fabrics, and methods for producing polyphenylene ether fibers.

[0002] Polyphenylene ether (hereinafter sometimes referred to as "PPE") has excellent heat resistance, flame retardancy, strength, and chemical resistance, and molded articles formed from PPE are used in a wide range of fields. Examples of molded articles formed from PPE include PPE melt-spun fibers and fabrics and nonwovens formed from these fibers (for example, Patent Document 1).

[0003] Furthermore, in the textile field, a method of applying a highly heat-resistant silicone oil is known to suppress the fusion of fibers. Examples of highly heat-resistant silicone oils include amino-modified silicones, epoxy-modified silicones, and alkylene oxide-modified silicones (for example, Patent Document 2).

[0004] International Publication No. 2021 / 060210, Japanese Patent Publication No. 2001-172880

[0005] One application of heat-resistant PPE fibers is heat-resistant felt for heat shielding purposes. While PPE fibers have excellent heat resistance and flame retardancy, repeated exposure to heat can cause the fibers to partially fuse together, resulting in a loss of flexibility in the fibers and nonwoven fabric.

[0006] High-temperature resistant silicone oils were effective in suppressing fusion in PPE fibers and structures such as nonwoven fabrics using these fibers. However, it was newly discovered that when PPE fibers have an elongation of a certain degree or more (for example, 100% or more), the fiber properties after impregnation with high-temperature resistant silicone oils may deteriorate drastically. This deterioration in fiber properties leads to problems such as poor process passability and inability to form nonwoven fabrics.

[0007] Therefore, the object of the present invention is to provide PPE fibers impregnated with an oil containing a high heat-resistant silicone and having high elongation, a nonwoven fabric containing said PPE fibers, and a method for producing said PPE fibers.

[0008] As a result of diligent research, the inventors of the present invention have found that by keeping the amount of oil containing high heat-resistant silicone within a certain range, the deterioration of the mechanical properties of the fibers after oil application is suppressed, and furthermore, fusion due to repeated use is reduced, thus completing the present invention.

[0009] The present invention relates to a PPE fiber containing a PPE component, wherein the PPE fiber is impregnated with an oil containing a high heat-resistant silicone, the amount of the oil containing the high heat-resistant silicone impregnated is 0.012% by mass or more and 0.110% by mass or less relative to the mass of the PPE fiber, and the elongation is 100% or more.

[0010] Preferably, the high heat-resistant silicone is one or more silicones selected from the group consisting of amino-modified silicones, epoxy-modified silicones, and carboxylic acid-modified silicones.

[0011] It is preferable that the PPE component has a dislocation structure in which it is connected by ortho bonds within a repeating unit consisting of consecutive para bonds.

[0012] The repeating unit formed by the aforementioned para-position bonding is given by the following general formula (1): (In the formula, R １ , R ２ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may have substituents, and R ３ Each of these is a repeating unit represented by (which independently represents a hydrocarbon group having 1 to 10 carbon atoms, which may have substituents), and the rearrangement structure is represented by the following general formula (2): (In the formula, R １ , R ２ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may have substituents, and R ３ Each is independently a hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and R ３ ' is the aforementioned R ３ It is preferable that the structure be represented by (representing a divalent group from which one hydrogen atom has been removed).

[0013] It is preferred that the content of rearranged structures in the PPE component having the rearranged structure is 0.05 mol% or more relative to all PPE structural units in the PPE component.

[0014] It is preferred that the content of the PPE component is 95 mass% or more based on all components forming the fiber.

[0015] It is preferred that the single-filament fineness of the PPE fiber is 1.0 dtex or more and 100 dtex or less.

[0016] The present invention also relates to a nonwoven fabric comprising the PPE fiber.

[0017] The present invention further relates to a method for producing the PPE fiber, comprising the steps of: melt-extruding PPE as a raw material using an extruder equipped with a cylinder and a screw; and discharging the molten PPE from a spinning nozzle to perform spinning.

[0018] It is preferred that an oil agent is applied in the spinning step.

[0019] In a PPE fiber, by adjusting the application amount of an oil agent containing high heat-resistant silicone to a specific range, it is possible to provide a PPE fiber in which degradation of mechanical properties is suppressed and thermal fusion bonding between fibers is further reduced, a nonwoven fabric comprising the PPE fiber, and a method for producing the same.

[0020] The present invention is characterized by controlling the application amount of an oil agent containing high heat-resistant silicone. If the application amount is too low, not only the expected fusion suppression effect cannot be obtained, but also the convergence of the yarn is significantly reduced, leading to troubles in subsequent processes. Furthermore, when the PPE fiber has an elongation of a certain level or more, if the application amount of the oil agent containing high heat-resistant silicone is too high, the mechanical properties will degrade. In the field of PPE fibers, degradation of mechanical properties caused by application of a high heat-resistant silicone oil agent has not been known previously. After discovering this fact, identifying a PPE fiber that suppresses fusion, has excellent flexibility, and can suppress degradation of mechanical properties, and a method for producing the same, can be said to be an innovative approach.

[0021] Although the details of the mechanism of the aforementioned reduction in mechanical properties are unclear, it is presumed that the high heat-resistant silicone oil agent penetrates into the non-oriented freely deposited portions of PPE fibers, and these portions become defects, which makes the yarn prone to breakage. In the present invention, it is considered that by controlling the add-on amount of the oil agent containing high heat-resistant silicone, defects can be suppressed by reducing the amount of the oil agent that penetrates into the PPE fibers.

[0022] It is a cross-sectional view schematically showing one embodiment of the method for producing a PPE fiber of the present invention.

[0023] 1. PPE Fibers The PPE fiber of the present invention contains a PPE component, an oil agent containing high heat-resistant silicone is attached to the PPE fiber, the add-on amount of the oil agent containing the high heat-resistant silicone is 0.012 mass% or more and 0.110 mass% or less relative to the mass of the PPE fiber, and the elongation is 100% or more.

[0024] The oil agent is not particularly limited as long as it contains high heat-resistant silicone.

[0025] The high heat-resistant silicone is preferably one or more silicones selected from the group consisting of amino-modified silicones, epoxy-modified silicones, and carboxylic acid-modified silicone oils, and amino-modified silicones are more preferred from the viewpoint of adsorptivity to fibers.

[0026] The amino-modified silicone is a silicone having an amino group as a modifying group (including an organic group having an amino group). The bonding position of the modifying group is not particularly limited; it may be bonded to a side chain of the silicone main chain, may be bonded to a terminal, or may be bonded to both. Further, the amino group may be any of a monoamine type, a diamine type, and a polyamine type, and both may coexist in one molecule.

[0027] Examples of the amino-modified silicone include, but are not limited to, the amino-modified silicone represented by the following formula (3). (In formula (3), R ４ , R ５ , R ６ and R ７Each of these is independently a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms which may have substituents, or an amino group-containing group. However, R ４ , R ５ , R ６ and R ７ At least one of these is an amino group-containing group. m is between 1 and 10000. n is between 1 and 10000.

[0028] R in the general formula (3) ４ ~R ７ As for the hydrocarbon group having 1 to 10 carbon atoms, R in general formula (1) described later is １ ~R ３ Hydrocarbon groups having 1 to 10 carbon atoms can be preferably used.

[0029] The aforementioned amino group-containing group can be any group containing an amino group and is not particularly limited, but for example, a group represented by the following general formula (4) is preferred. (In formula (4), R １１ and R １３ Each of these is independently an alkanediyl group having 1 to 10 carbon atoms or a group having -O- between carbon atoms of the alkanediyl group. １２ , R １４ and R １５ Each of these is independently either a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. p is an integer from 0 to 5. * represents a bond with a silicon atom.

[0030] Commercially available amino-modified silicones can also be suitably used. Specifically, examples include TK Silicone AS-1020 manufactured by Takamatsu Oil & Fat Co., Ltd.

[0031] Epoxy-modified silicones are silicones having an epoxy group (including an organic group having an epoxy group) as a modifying group. The bonding position of the modifying group is not particularly limited, but it may be bonded to the side chain of the main chain silicone, to the end, or to both.

[0032] Carboxylate-modified silicones are silicones having a carboxyl group (including organic groups containing a carboxyl group) as a modifying group. The bonding position of the modifying group is not particularly limited, but it may be bonded to the side chains of the main chain silicone, to the ends, or to both.

[0033] As epoxy-modified silicones and carboxylic acid-modified silicones, those commonly used in this field can be used.

[0034] The content of the high heat-resistant silicone is preferably 70% by mass or more, and more preferably 80% by mass or more, in the oil. Alternatively, the oil may consist only of high heat-resistant silicone (i.e., 100% by mass).

[0035] The aforementioned oil may be used after being diluted with a solvent such as water. Dilution with a solvent is preferable because it reduces viscosity and minimizes uneven application. The dilution concentration is not particularly limited, but the active ingredient is approximately 0.1 to 20% by weight.

[0036] The amount of the oil containing the high heat-resistant silicone impregnated is 0.012% by mass or more, preferably 0.015% by mass or more, when the mass of the PPE fiber is 100% by mass. Furthermore, the amount of impregnated material is 0.110% by mass or less, preferably 0.100% by mass or less. If the amount of impregnated material is too small, not only will the expected fusion suppression effect not be obtained, but the convergence of the yarn will be significantly reduced, leading to problems in the next process. If the amount of impregnated material exceeds the above range, the mechanical properties may be significantly reduced, more specifically, the mechanical properties will be reduced in PPE fibers with a tensile elongation of 100% or more. That is, if the elongation of the PPE fiber is 100% or less, the reduction in mechanical properties can be suppressed, and methods such as oriented molecular chains by stretching can be considered. However, if the elongation is reduced by these methods, the residual strain will also increase, making it more susceptible to shrinkage due to heat, which is undesirable. The amount of impregnated material can be quantified using nuclear magnetic resonance spectroscopy.

[0037] The elongation of the PPE fibers after oil impregnation is 100% or more, preferably 110% or more, and more preferably 120% or more. The upper limit of the elongation of the PPE fibers is not particularly limited, but for example, it is about 300% or less. In the present invention, by setting the amount of oil impregnation within a specific range, excellent elongation can be achieved without degrading mechanical properties.

[0038] The glass transition temperature of the PPE fiber of the present invention is preferably 170°C or higher, more preferably 175°C or higher, and even more preferably 180°C or higher. Having the glass transition temperature within this range provides extremely high heat resistance. While there is no particular upper limit, from the viewpoint of moldability, it is preferably 300°C or lower, and more preferably 250°C or lower.

[0039] The PPE fibers of the present invention may also be short fibers. These short fibers can be obtained, for example, by cutting fibers that have been formed into a tow by splicing PPE fibers together.

[0040] The fineness of the single filament of the PPE fiber is not particularly limited and can be appropriately determined depending on the purpose for which the fiber is used, but for example, 1 dtex or more and 100 dtex or less is preferred, 1.2 dtex or more and 60 dtex or less is more preferred, and 1.5 dtex or more and 40 dtex or less is even more preferred.

[0041] The following describes the PPE components contained in the PPE fibers of the present invention.

[0042] <PPE components> The PPE components are not particularly limited and include those commonly used in this field. Specifically, the following general formula (1): (In the formula, R １ , R ２ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and R ３Examples include homopolymers having repeating units represented by (wherein each of them independently represents a hydrocarbon group having 1 to 10 carbon atoms which may have substituents), copolymers containing two or more different repeating units of general formula (1), and copolymers having repeating units of general formula (1) and repeating units other than general formula (1).

[0043] R in the general formula (1) １ ~R ３ Examples of hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, and decyl groups; aryl groups having 6 to 10 carbon atoms such as phenyl, 4-methylphenyl, 1-naphthyl, and 2-naphthyl groups; and aralkyl groups having 7 to 10 carbon atoms such as benzyl, 2-phenylethyl, and 1-phenylethyl groups.

[0044] If the hydrocarbon group has substituents, examples of substituents include halogen atoms such as fluorine atoms, and alkoxy groups such as methoxy groups. Specific examples of hydrocarbon groups with substituents include, for example, trifluoromethyl groups.

[0045] Among these, R １ , R ２ As for the hydrogen atom, a methyl group is preferred, and a hydrogen atom is more preferred, R ３ A methyl group is preferred as the component.

[0046] Specific examples of the repeating unit of the general formula (1) include repeating units derived from 2,6-dimethyl-1,4-phenylene ether, 2,6-diethyl-1,4-phenylene ether, 2-methyl-6-ethyl-1,4-phenylene ether, and 2,6-dipropyl-1,4-phenylene ether. Among these, the repeating unit derived from 2,6-dimethyl-1,4-phenylene ether is preferred.

[0047] Furthermore, the PPE may contain repeating units other than those of general formula (1) as long as it does not impair the effects of the present invention. The content of such repeating units other than those of general formula (1) is not particularly limited as long as it does not impair the effects of the present invention, but for example, it is preferably about 5 mol% or less in the copolymer, and more preferably it is not included.

[0048] The PPE component preferably has a dislocation structure connected by ortho bonds within a repeating unit that is continuous by para bonds. Examples of the repeating unit that is continuous by para bonds include the repeating unit represented by the above general formula (1), and examples of the dislocation structure include the following general formula (2): (In the formula, R １ , R ２ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and R ３ Each of these is independently a hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and R ３ ' is the aforementioned R ３ One possible rearrangement structure is represented by (representing a divalent group from which one hydrogen atom has been removed).

[0049] In the above general formula (2), R １ ~R ３ Examples include those similar to those in general formula (1) above. The "~" in general formula (2) indicates that the structure beyond it is not particularly limited. The "~" portion may be formed from phenylene ether units connected by para bonds, or it may have a portion that is partially bonded at the ortho position.

[0050] The aforementioned R ３ ' is the aforementioned R ３ This represents a divalent group from which one hydrogen atom has been removed, and it is preferably a methylene group.

[0051] The PPE component having the aforementioned rearrangement structure is preferably a homopolymer having repeating units of general formula (1), a copolymer containing two or more different repeating units of general formula (1), or a copolymer containing repeating units of general formula (1) and repeating units other than general formula (1) that has a rearrangement structure represented by general formula (2).

[0052] If the PPE component has a dislocation structure, the amount of the dislocation structure (hereinafter also referred to as "dislocation amount") is preferably 0.05 mol% or more, preferably 0.1 mol% or more, and more preferably 0.5 mol% or more, relative to the total structural units constituting the PPE component. Furthermore, the dislocation amount is preferably 15 mol% or less, more preferably 10 mol% or less, and even more preferably 8 mol% or less. Having the dislocation amount in the PPE component having a dislocation structure within the above range is preferable because it improves fluidity to a degree that allows for melt molding, enabling the formation of melt-spun fibers.

[0053] The aforementioned dislocation structure is observed in the nuclear magnetic resonance spectrum ( １ In 1H-NMR measurements, it is preferable to show peaks in the ranges of 3.8–4.0 ppm and 6.8–7.0 ppm. Typically, PPE shows a peak around 6.4–6.6 ppm, which is a peak originating from the hydrogen atoms at positions 3 and 5 of the benzene ring in the PPE main chain. PPE having the rearrangement structure shows peaks in the ranges of 3.8–4.0 ppm and 6.8–7.0 ppm, in addition to the peak around 6.4–6.6 ppm. The chemical shift at 3.8–4.0 ppm is due to R in the rearrangement structure. ３ This originates from the proton of the divalent group (e.g., methylene group) indicated by ', and the chemical shift of 6.8 to 7.0 ppm is due to the R at the 3 and 5 positions of PPE in the rearrangement structure. １ , R ２ It originates from the protons of the group (for example, the hydrogen atoms at positions 3 and 5 of the benzene ring bonded to the ortho position via a methylene group).

[0054] The weight-average absolute molecular weight (Mw) of the PPE component is preferably 10,000 g / mol or more, more preferably 20,000 g / mol or more, even more preferably 30,000 g / mol or more, and particularly preferably 35,000 g / mol or more. Furthermore, the weight-average absolute molecular weight (Mw) is preferably 150,000 g / mol or less, more preferably 100,000 g / mol or less, and even more preferably 80,000 g / mol or less. Setting the weight-average absolute molecular weight (Mw) within the above range is preferable from the viewpoint of heat resistance. Here, weight-average absolute molecular weight (Mw) refers to the true weight-average molecular weight of the polymer. The weight-average molecular weight measured by conventional gel permeation chromatography (GPC) is a relative weight-average molecular weight obtained using linear polystyrene or the like with a known molecular weight as a standard polymer, and in cases where branched structures exist in the polymer, it may not be possible to accurately evaluate the molecular weight. The weight-average absolute molecular weight (Mw) is measured using a GPC instrument equipped with a predetermined column and a multi-angle light scattering detector, allowing for accurate molecular weight measurement without being affected by polymer structures such as branched structures. The weight-average absolute molecular weight (Mw) can be measured by the method described in the examples below. This weight-average absolute molecular weight (Mw) is different from the weight-average (relative) molecular weight obtained by the conventional GPC method using polystyrene equivalent values ​​(relative values).

[0055] The number-average absolute molecular weight (Mn) of the PPE component is preferably 8,000 g / mol or more, more preferably 9,000 g / mol or more, and even more preferably 10,000 g / mol or more. Furthermore, the number-average absolute molecular weight (Mn) is preferably 100,000 g / mol or less, more preferably 80,000 g / mol or less, and even more preferably 70,000 g / mol or less. Setting the number-average absolute molecular weight (Mn) within the above range is preferable from the viewpoint of heat resistance. Here, the number-average absolute molecular weight (Mn) is the true number-average molecular weight of the polymer, and, like the weight-average absolute molecular weight (Mw), is measured by a GPC device equipped with a predetermined column and a multi-angle light scattering detector. This number-average absolute molecular weight (Mn) is different from the number-average (relative) molecular weight obtained by the polystyrene equivalent value (relative value) obtained by the conventional GPC method.

[0056] The absolute molecular weight dispersion (weight-average absolute molecular weight (Mw) / number-average absolute molecular weight (Mn)) of the PPE component is preferably 5.0 or less, more preferably 4.5 or less, and even more preferably 4.0 or less. Mw / Mn is 1 or greater. A larger Mw / Mn tends to broaden the glass transition peak. Therefore, from a quality standpoint, it is preferable to keep it within the above range.

[0057] The relative molecular weight of the PPE component is not particularly limited, but the weight-average relative molecular weight (Mw') is preferably 40,000 to 100,000, and more preferably 50,000 to 80,000. The number-average relative molecular weight (Mn') is preferably 7,000 to 30,000, and more preferably 8,000 to 20,000. The relative molecular weight dispersion (Mw' / Mn') is preferably 2.5 to 9.0, and more preferably 2.8 to 8.0.

[0058] The PPE component content is preferably 95% by mass or more of the total components forming the PPE fiber, more preferably 98% by mass or more, and even more preferably substantially composed of only PPE components (100% by mass). Having the PPE component content in the PPE fiber within the above range is preferable because it not only provides excellent mechanical strength to the resulting fiber, but also excellent heat resistance, chemical resistance, flame retardancy, etc.

[0059] <Components other than PPE components> The PPE fiber of the present invention may contain resin components other than the PPE components. Examples of resin components other than PPE components include styrene, polyethylene, polypropylene, polyamides such as polyamide 4, polyamide 6, polyamide 10, polyamide 11, polyamide 66, polyamide 6T, polyamide 6T / 11, polyesters such as polyethylene terephthalate and polybutylene terephthalate, and polycarbonates. However, the content of these components is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably none (0% by mass).

[0060] Furthermore, the PPE fibers of the present invention may also contain additives such as lubricants, plasticizers, antioxidants, ultraviolet absorbers, pigments, dyes, and antistatic agents, to the extent that they do not impair the effects of the present invention.

[0061] The PPE fibers of the present invention are preferably manufactured by the PPE fiber manufacturing method described below.

[0062] 2. Method for producing PPE fibers The method for producing PPE fibers according to the present invention includes the steps of melting and extruding raw material PPE using an extruder equipped with a cylinder and a screw, and spinning the molten PPE by extruding it from a spinning nozzle.

[0063] An example of manufacturing PPE melt-spun fibers will be explained using Figure 1. The raw material, PPE, is fed from the hopper 1 in Figure 1 into an extruder 2 equipped with a cylinder and a screw. The molten PPE is discharged at a rate measured by a gear pump 3, passes through a filter material 4 composed of fine sand or the like, and is discharged from a spinning nozzle 5 to obtain melt-spun fibers. The extruder may be equipped with a degassing vent 10, and extrusion may be performed while degassing. An inert gas may be introduced into the extruder 2 at the end of the degassing vent 10 to prevent oxygen from entering, or a vacuum pump may be attached. Furthermore, it is preferable to install a filter 6 made of a metal nonwoven fabric or the like on the filter material 4. Installing the filter 6 is preferable because it can remove foreign matter in advance and prevent clogging of the filter material 4.

[0064] Furthermore, a heat retention space 7 is provided directly below the spinning nozzle 5, and it is preferable to introduce an inert gas such as nitrogen 8 into this area during spinning, from the viewpoint of suppressing nozzle clogging due to oxidative crosslinking. It is even more preferable to introduce a heated inert gas using a heating torch 9. The temperature of the heated inert gas is preferably 100°C to 500°C, and more preferably 200°C to 400°C.

[0065] The end of the degassing vent 10 may be an open vent with nothing attached, or it may be a vacuum vent that actively degasssed by suction by connecting a vacuum pump. When performing vacuum venting, a trap to collect volatile components may be provided between the vent and the vacuum pump. In the present invention, a vacuum vent is preferred.

[0066] The spinning speed is not particularly limited and can be set appropriately according to the required fineness, etc., but in order to stably obtain fine fibers, a speed of about 100 m / min or more is preferred, and about 200 m / min or more is more preferred. Furthermore, a speed of about 5000 m / min or less is preferred, and about 4000 m / min or less is more preferred.

[0067] The single-hole discharge rate of the spinning nozzle is preferably 3.0 g / min or less, more preferably 2.8 g / min or less, and even more preferably 2.6 g / min or less. The lower limit of the single-hole discharge rate is not particularly limited, but is preferably 0.05 g / min or more, more preferably 0.1 g / min or more, and even more preferably 0.12 g / min or more.

[0068] The ratio of the diameter D to the length L of the spinning nozzle (L / D) is preferably 3 to 20, and more preferably 4 to 10. Having the ratio of the diameter D to the length L of the spinning nozzle within this range is preferable from the viewpoint of uniform distribution because it appropriately applies pressure loss in the orifice section.

[0069] Examples of PPE used as a raw material include homopolymers having the repeating unit of general formula (1), copolymers containing two or more different repeating units of general formula (1), and copolymers having the repeating unit of general formula (1) and repeating units other than general formula (1). The content of repeating units other than general formula (1) in the copolymer can be as described above. Among these, homopolymers having the repeating unit of general formula (1) are preferred.

[0070] Examples of homopolymers having the repeating unit of the general formula (1) include poly(2,6-dimethyl-1,4-phenylene ether), poly(2,6-diethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), and poly(2,6-dipropyl-1,4-phenylene ether), but among these, poly(2,6-dimethyl-1,4-phenylene ether) is preferred.

[0071] As the poly(2,6-dimethyl-1,4-phenylene ether) mentioned above, commercially available products can also be suitably used. Specifically, examples include PPO640, PPO646, and PPOSA120 manufactured by SABIC Innovative Plastic, and Xylon S201A and Xylon S202A manufactured by Asahi Kasei Chemicals Corporation.

[0072] Furthermore, when melting PPE, the melt viscosity can be reduced by mixing PPE with high Tg and low Tg.

[0073] The glass transition temperature of the PPE component having a high glass transition temperature is preferably 170°C or higher, more preferably 200°C or higher, and even more preferably 210°C or higher. While there is no particular upper limit to the glass transition temperature, it is preferably 230°C or lower. Having the glass transition temperature of the raw material PPE within this range is preferable because it allows for the acquisition of PPE fibers with high heat resistance.

[0074] The glass transition temperature of the PPE component having a low glass transition temperature is preferably less than 170°C. Adding PPE with a glass transition temperature of less than 170°C reduces the melt viscosity and improves fluidity.

[0075] The content of PPE having a glass transition temperature of 170°C or higher is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more, in the PPE component of the raw material. Furthermore, there is no particular upper limit to the content of PPE having a glass transition temperature of 170°C or higher, but it is preferably 100% by mass or less. In the present invention, including PPE with a high glass transition temperature (i.e., high molecular weight) within the above range is preferable because it results in excellent mechanical strength, heat resistance, chemical resistance, flame retardancy, etc. of the resulting PPE molten fibers.

[0076] Furthermore, along with the raw material PPE, the material may also contain resin components and additives other than PPE. The resin components and additives other than PPE are as described above. The content of resin components other than PPE is preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably none (0% by mass).

[0077] As the extruder equipped with the cylinder, screw, and degassing vent, a single-screw extruder or a twin-screw extruder, which are commonly used in this field, can be used. In the present invention, it is preferable to use a twin-screw extruder.

[0078] The peripheral speed of the screw is not particularly limited and can be within the range commonly used in this field. However, when forming fibers using a PPE component having a dislocation structure, the peripheral speed of the screw must be such that the dislocation reaction of the raw material PPE occurs, and is preferably 3.6 m / min or more, more preferably 3.7 m / min or more, and even more preferably 3.8 m / min or more. Furthermore, the upper limit of the peripheral speed of the screw is not particularly limited, but is preferably 94.2 m / min or less. In the present invention, by increasing the screw rotation speed to 3.6 m / min or more, a high shear force can be applied to the raw material PPE in the cylinder, and as a result, the molecular chains of PPE can be cleaved and PPE having a dislocation structure can be formed.

[0079] If the temperature inside the cylinder is too low, the fluidity of the resin will be poor, and if it is too high, although the fluidity will improve, foaming will occur due to thermal decomposition of the resin. Therefore, it is necessary to select a processing temperature that strikes a balance between these two factors. For example, the temperature inside the cylinder is preferably between 250°C and 350°C, and more preferably between 280°C and 330°C.

[0080] The surface temperature of the spinning nozzle is not particularly limited, but is preferably 300°C or higher, more preferably 320°C or higher, and even more preferably 330°C or higher. A nozzle surface temperature within this range is preferable because it results in fluidity suitable for spinning.

[0081] The method of impregnating the oil is not limited and can be performed at any time during or after spinning, but it is preferable to perform it during spinning. The method of impregnation during spinning is not limited and can include, for example, physically converging the yarn with a guide and quantitatively supplying it with a gear pump or the like. When impregnating, the active ingredient may be diluted in a solvent such as water to a concentration of about 0.1 to 20% by weight. The discharge amount is not particularly limited and should be an amount that can achieve the desired amount of oil impregnated. For example, the diluent is preferably about 0.015 g / min to 1.0 g / min per single yarn, and more preferably about 0.02 g / min to 0.5 g / min. By setting the discharge amount within the above range, the amount of oil impregnated can be set to an appropriate range.

[0082] As an oil-based agent, it is as described above.

[0083] 3. PPE Nonwoven Fabric The present invention relates to a PPE nonwoven fabric formed from the PPE fibers.

[0084] The method for manufacturing PPE nonwoven fabric is not particularly limited, and methods commonly used in this field can be appropriately adopted. Examples of nonwoven fabric manufacturing methods include the spunbond method, meltblown method, spunlace method, needle punch method, thermal bond method, and chemical bond method.

[0085] Because the PPE nonwoven fabric of the present invention uses the PPE fibers of the present invention, fusion between fibers can be suppressed even when repeatedly used in high-temperature environments, and as a result, the nonwoven fabric has excellent flexibility.

[0086] The PPE nonwoven fabric of the present invention can be used in applications requiring heat resistance and flexibility, and can be suitably used, for example, as padding in insulating materials for heat retention, heat-resistant felt for heat shielding, sputter sheets, and the like.

[0087] 4. Activated carbon fibers, activated carbon fiber nonwovens. The present invention also relates to activated carbon fibers made of PPE fibers, and activated carbon fiber nonwovens made of PPE nonwovens.

[0088] The activated carbon fibers and activated carbon fiber nonwoven fabrics of the present invention are formed from the PPE fibers and PPE nonwoven fabrics. Specifically, the PPE fibers or PPE nonwoven fabrics are treated in at least one step selected from a process consisting of an infusibility treatment (for example, heat treatment at 120 to 400°C for 0.1 to 100 hours in an air atmosphere with a water vapor concentration of 0.5 to 20 vol.%) and a carbonization treatment, and the resulting fibers are then activated.

[0089] The activated carbon fibers and activated carbon fiber nonwoven fabrics of the present invention can be suitably used in applications such as water purification, air purification, gas adsorption, water treatment, and various filters such as canisters.

[0090] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The evaluation methods for physical properties, etc., in the following examples are as follows, and unless otherwise specified, the measurement of physical properties, etc., means measurement at room temperature of 20°C / relative humidity of 65%.

[0091] (1) Fineness and single filament fineness were measured according to the method described in JIS L-1095 9.4.1. Single filament fineness was calculated by dividing the fineness by the number of filaments.

[0092] (2) Maximum point stress and maximum point elongation were measured in accordance with JIS L-1013 8.5.1. The stress at the maximum load was defined as the maximum point stress, and the elongation rate at the maximum load was defined as the maximum point elongation.

[0093] (3) Glass transition temperature (Tg) Using a differential scanning calorimetry analyzer (model: DSC-Q100) manufactured by TA Instruments Inc., 2 mg of PPE fiber was measured from 30°C to 250°C in a nitrogen atmosphere at a heating rate of 10°C / min. The temperature at the intersection of the extension of the baseline below the glass transition temperature and the tangent line showing the maximum slope in the transition region was defined as the glass transition temperature (Tg).

[0094] (4) The amount of dislocation structure in PPE fibers at a resonance frequency of 600 MHz １ The measurement was performed using 1H-NMR. A BRUKER NMR spectrometer (model name: AVANCE-NEO600) was used, and the measurement was performed as follows: 10 mg of PPE fiber obtained in the examples and comparative examples was dissolved in deuterated chloroform, and the solution was packed into an NMR tube within 2 hours for measurement. Deuterated chloroform was used as the locking solvent, with a waiting time of 1 second, a data acquisition time of 4 seconds, and 64 integration cycles. Deuterated benzene may also be used as the solvent. The rearrangement structure amount was analyzed as follows: R at the 3 and 5 positions of PPE. １ , R ２ Peaks originating from the proton of the base and R in the dislocation structure ３ The peak integrals of the peaks originating from the protons of the divalent group (methylene group, etc.) indicated by ' were denoted as A and B, and the rearrangement structure weight was calculated using the following formula: Rearrangement structure weight (mol%) = (B / (A + B)) × 100

[0095] (5) Oil impregnation amount Resonance frequency 600 MHz １ The measurement was performed using 1H-NMR. The measurement device used was a BRUKER NMR spectrometer (device name: AVANCE-NEO600), and the measurement was performed as follows. 20 mg of PPE fiber obtained in the examples and comparative examples was dissolved in deuterated chloroform, and the solution was filled into an NMR tube for measurement. Deuterated chloroform was used as the locking solvent, with a waiting time of 1 second, a data acquisition time of 4 seconds, and a total of 128 integrations. The analysis of the amount of oil impregnated was performed as follows: R at the 3 and 5 positions of PPE. １ , R ２Let's take the case where the group is a hydrogen atom as an example. Let A be the peak integral value originating from the hydrogen atoms at positions 3 and 5 of PPE, and B be the peak integral value originating from the dimethylsiloxane unit observed around 0 ppm. The amount of oil impregnated was calculated using the following formula: Amount of oil impregnated (mass%) = ((B / 6) × 74) × 100 / ((A / 2) × 120)

[0096] (6) Molecular weight measurement (6-1) Absolute molecular weight The number-average molecular weight (Mn), weight-average molecular weight (Mw), and molecular weight dispersion (Mw / Mn) of the absolute molecular weight were all determined using gel permeation chromatography (GPC). The measurement conditions were as follows. Apparatus: OMNISEC RESOLVE (manufactured by Spectris Co., Ltd.) Detector: OMNISEC REVEAL (differential refractive index detector, light scattering detector, viscosity detector, manufactured by Spectris Co., Ltd.) Column: TSKgel SuperHM-H manufactured by Tosoh Corporation (two columns connected in series) Solvent: Chloroform Temperature: 40°C Flow rate: 0.6 mL / min Sample concentration: 1.0 mg / mL Injection volume: 20 μL (6-2) Relative molecular weight The number average molecular weight (Mn'), weight average molecular weight (Mw'), and molecular weight dispersion (Mw' / Mn') of the relative molecular weight in polystyrene equivalent were measured under the same conditions as in "(6-1) Absolute molecular weight" above, and a differential refractive index detector was used. The standard polystyrene used to create the calibration curve is as follows. Standard samples: Monodisperse polystyrene "waters Polystyrene Standard (peak MW = 2698)" "Shodex STANDARD SM-105 (S-3.37, S-13.9, S-30.3, S-52.4, S-205, S-696, S-1110, S-2210, S-3740)" Samples were prepared by dissolving 5 mg of PPE fiber obtained in the examples and comparative examples in 5 mL of chloroform.

[0097] (7) Peripheral speed of the screw The peripheral speed of the screw was determined by the following formula: Peripheral speed of the screw (m / min) = Screw diameter (mm) × 0.00314 × Screw rotation speed (rpm)

[0098] (8) Fusion rate of fibers after heat treatment PPE fiber multifilaments were suspended in a dryer at 200°C and left for 30 minutes before being removed and cooled to room temperature. The threads were then floated in water to separate them, and the number of threads was counted. The fusion rate was then calculated using the following formula: Fusion rate (%) = (Original filament count - Number of threads after heat treatment) / (Original filament count - 1) × 100

[0099] (9) Flexibility of nonwoven fabric after heat treatment The obtained PPE fiber nonwoven fabric was heat-treated three times in air at 200°C for 30 minutes each time, and then wrapped around a cylinder with a diameter of 50 mmφ and evaluated according to the following evaluation criteria. ○: It was possible to wrap it without cracks or splits occurring. ×: Cracks or splits occurred.

[0100] (10) Crimping performance The wound yarn was crimped using a crimper while being unraveled lengthwise. The following evaluation criteria were used for evaluation. ○: Unraveled lengthwise and threaded through the crimper. ×: Single thread breakage occurred during unraveling lengthwise, and the yarn could not be threaded through the crimper.

[0101] (11) Basis weight Measured in accordance with JIS L1906 (2000) 5.2 Mass per unit area.

[0102] Example 1 Poly(2,6-dimethyl-1,4-phenylene ether) (PPO (trademark registered) 640, glass transition temperature (Tg): 221°C, manufactured by SABIC Innovative Plastic) was extruded using a twin-screw extruder manufactured by Technovel Co., Ltd. (product name: KZW15TW-30MG). The twin-screw extruder has four cylinder zones, and the cylinders from the hopper side were designated as cylinders 1, 2, 3, and 4. Cylinder 1 was set to 280°C, and cylinders 2-4 and the cylinder head were set to 300°C. The screw rotation speed was set to 700 rpm, and the peripheral speed of the screw was 33.0 m / min. A vent was attached to cylinder 3 and vacuum was applied.

[0103] A gear pump was installed downstream of the extruder, and the polymer was extruded through a metal nonwoven fabric filter (product name: NF-10, manufactured by Nippon Seisen Co., Ltd.) into a nozzle (nozzle hole diameter: 0.80 mm, nozzle hole land length: 4.0 mm, number of nozzle holes: 48) (total discharge volume: 50.0 g / min). The nozzle surface temperature was set to 340°C. The polymer extruded from the nozzle was wound up at a spinning speed of 316 m / min. Just before winding, an amino-modified silicone (product name: TK Silicone AS-1020, manufactured by Takamatsu Oil & Fat Co., Ltd.) was applied to the PPE fiber at a concentration of 0.015% by mass using a guide and a gear pump.

[0104] The obtained PPE fibers were crimped, cut to a length of 76 mm, and then punched using a needle punching machine to achieve a needle density of 100 needles / cm². ２ The needle was treated on both sides with a needle depth of 2 mm (front) and 7 mm (back), resulting in a weight of 460 g / m². ２ We obtained a PPE nonwoven fabric.

[0105] Example 2 PPE fibers were obtained in the same manner as in Example 1, except that the nozzle surface temperature was changed to 343°C during the formation of the PPE fibers. Using these PPE fibers, a PPE nonwoven fabric was obtained in the same manner as in Example 1.

[0106] Example 3 PPE fibers were obtained in the same manner as in Example 1, except that the nozzle surface temperature was changed to 345°C and the spinning speed to 690 m / min. Using these PPE fibers, a PPE nonwoven fabric was obtained in the same manner as in Example 1.

[0107] Example 4 PPE fibers were obtained in the same manner as in Example 1, except that the amount of oil impregnation was changed to 0.050% by mass when forming the PPE fibers. Using these PPE fibers, a PPE nonwoven fabric was obtained in the same manner as in Example 1.

[0108] Example 5 PPE fibers were obtained in the same manner as in Example 1, except that the amount of oil impregnation was changed to 0.100% by mass when forming the PPE fibers. Using these PPE fibers, a PPE nonwoven fabric was obtained in the same manner as in Example 1.

[0109] Example 6 PPE fibers were obtained in the same manner as in Example 1, except that the raw material for forming the PPE fibers was changed to poly(2,6-dimethyl-1,4-phenylene ether) (IUPIACE PX100F, glass transition temperature (Tg): 214°C, manufactured by Global Polyacetal Co., Ltd.). Using these PPE fibers, a PPE nonwoven fabric was obtained in the same manner as in Example 1.

[0110] Comparative Example 1: PPE fibers were obtained using the same method as in Example 1, except that the nozzle surface temperature was 335°C, the spinning speed was 690 m / min, and water was used to converge and wind the fibers instead of an oil. The obtained fibers lacked convergence properties and could not be crimped, so they could not be made into a nonwoven fabric.

[0111] Comparative Example 2 PPE fibers were obtained in the same manner as in Comparative Example 1, except that the amount of oil impregnation was changed to 0.010% by mass. Using these PPE fibers, a PPE nonwoven fabric was obtained in the same manner as in Example 1.

[0112] Comparative Example 3: PPE fibers were obtained in the same manner as in Example 1, except that water was used to converge and wind the PPE fibers instead of an oil. The obtained fibers lacked convergence immediately after spinning and could not be crimped, so they could not be made into a nonwoven fabric.

[0113] Comparative Example 4: PPE fibers were obtained in the same manner as in Example 1, except that the amount of oil impregnation was changed to 0.010% by mass. A PPE nonwoven fabric was obtained using these PPE fibers in the same manner as in Example 1.

[0114] Comparative Example 5: PPE fibers were obtained in the same manner as in Example 1, except that the amount of oil impregnation was changed to 0.120% by mass. The obtained fibers had sufficient convergence and could be crimped, but the yarn became brittle due to shrinkage during heat treatment and broke when separated with water, making it impossible to evaluate the fusion rate. The obtained nonwoven fabric of fibers was brittle and could not be made into a nonwoven fabric.

[0115] Comparative Example 6: PPE fibers were obtained in the same manner as in Example 1, except that a silicon-free nonionic surfactant was used as the oil agent for forming the PPE fibers. A PPE nonwoven fabric was obtained using these PPE fibers in the same manner as in Example 1.

[0116]

[0117]

[0118] In Table 2, a "-" for the fiber fusion rate after heat treatment or the flexibility of the nonwoven fabric after heat treatment indicates that the measurement could not be performed.

[0119] The PPE fibers obtained in Examples 1 to 6 all had a fusion rate of 0%, possessed the convergence properties necessary for crimping, and could be crimped. Furthermore, the PPE nonwoven fabrics obtained in Examples 1 to 6 did not fuse even when repeatedly exposed to heat, and when their flexibility was checked, they could be wound without cracking. On the other hand, in Comparative Examples 1 and 3, because no oil was impregnated, fusion occurred, the convergence properties were lost, and crimping was not possible. Therefore, nonwoven fabric could not be obtained. Comparative Example 2 had convergence properties and could be crimped, but fusion occurred because the amount of oil impregnated was insufficient. Furthermore, when the flexibility of the obtained nonwoven fabric was checked after heat treatment, cracks appeared. In Comparative Example 4, fusion occurred due to the insufficient amount of oil impregnated. Furthermore, when the flexibility of the obtained nonwoven fabric was checked after heat treatment, cracks appeared. In Comparative Example 5, the mechanical properties of the PPE fibers deteriorated due to the excessive amount of oil impregnated. Although crimping was possible, the yarn became brittle due to shrinkage during heat treatment and broke when separated with water, making it impossible to evaluate the fusion rate. Furthermore, the resulting nonwoven fabric was brittle, making it impossible to evaluate its flexibility. In Comparative Example 6, a non-silicone oil with low heat resistance and no silicon was applied, resulting in partial fusion due to the decomposition heat of the oil during heat treatment. In addition, when the flexibility of the resulting nonwoven fabric was checked after heat treatment, cracks were found.

[0120] 1. Hopper 2. Extruder 3. Gear pump 4. Filter media 5. Spinning nozzle 6. Filter 7. Insulated space 8. Inert gas introduction 9. Heating torch 10. Degassing vent

Claims

1. A polyphenylene ether fiber containing a polyphenylene ether component, wherein the polyphenylene ether fiber is impregnated with an oil containing a high heat-resistant silicone, the amount of the oil containing the high heat-resistant silicone impregnated is 0.012% by mass or more and 0.110% by mass or less relative to the mass of the polyphenylene ether fiber, and the elongation is 100% or more.

2. The polyphenylene ether fiber according to claim 1, wherein the high heat-resistant silicone is one or more silicones selected from the group consisting of amino-modified silicones, epoxy-modified silicones, and carboxylic acid-modified silicones.

3. The polyphenylene ether fiber according to claim 1, wherein the polyphenylene ether component has a rearrangement structure in which it is connected by ortho bonds in a repeating unit that is continuous by para bonds.

4. The repeating unit formed by the para-position bond is given by the following general formula (1): (In the formula, R １ , R ２ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may have substituents, and R ３ Each of these is a repeating unit represented by (which independently represents a hydrocarbon group having 1 to 10 carbon atoms, which may have substituents), and the rearrangement structure is represented by the following general formula (2): (In the formula, R １ , R ２ Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms which may have substituents, and R ３ Each is independently a hydrocarbon group having 1 to 10 carbon atoms, which may have substituents, and R ３ ' is the aforementioned R ３ The polyphenylene ether fiber according to claim 3, having a structure represented by (representing a divalent group from which one hydrogen atom has been removed).

5. The polyphenylene ether fiber according to claim 3, wherein the amount of dislocation in the polyphenylene ether component having the dislocation structure is 0.05 mol% or more relative to the total polyphenylene ether structural units in the polyphenylene ether component.

6. The polyphenylene ether fiber according to claim 1, wherein the content of the polyphenylene ether component is 95% by mass or more of the total components forming the fiber.

7. The polyphenylene ether fiber according to claim 1, wherein the single filament fineness of the polyphenylene ether fiber is 1.0 dtex or more and 100 dtex or less.

8. A nonwoven fabric containing polyphenylene ether fibers according to any one of claims 1 to 7.

9. A method for producing polyphenylene ether fibers according to any one of claims 1 to 7, comprising the steps of: melting and extruding polyphenylene ether, which is a raw material, using an extruder equipped with a cylinder and a screw; and discharging the molten polyphenylene ether from a spinning nozzle and spinning it.

10. A method for producing polyphenylene ether fibers according to claim 9, wherein an oil agent is impregnated during the spinning process.

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