Combined filament yarn, method for producing molded article, and method for producing combined filament yarn

Abstract

The purpose of the present invention is to provide: a combined filament yarn having excellent flexibility and strength in a fiber length direction of a continuous reinforcing fiber; a method for producing a molded article; and a method for producing the combined filament yarn.　The combined filament yarn according to the present invention comprises continuous thermoplastic polyimide resin fibers (2) and continuous reinforcing fibers (1), wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fibers (2) to the fineness of the continuous reinforcing fibers (1) (the fineness of the continuous thermoplastic polyimide resin fibers (2) / the fineness of the continuous reinforcing fibers (1)) is 0.009-0.090, the combined filament yarn is configured with intertwining of at least some of the continuous thermoplastic polyimide resin fibers (2) and at least some of the continuous reinforcing fibers (1) at a proportion of 1-500 locations per 500 m, and in the other portions, the continuous thermoplastic polyimide resin fibers (2) and the continuous reinforcing fibers (1) are arranged in parallel with linearity in the fiber length direction.

Description

Method for manufacturing blended yarn and molded product, and method for manufacturing blended yarn

[0001] This invention relates to a method for manufacturing blended yarns and molded articles, and to a method for manufacturing blended yarns. In particular, it relates to blended yarns using thermoplastic polyimide resin.

[0002] Polyimide resins are useful engineering plastics with high thermal stability, high strength, and high solvent resistance due to the rigidity of their molecular chains, resonance stabilization, and strong chemical bonding, and are applied in a wide range of fields. Furthermore, crystalline polyimide resins can have their heat resistance, strength, and chemical resistance further improved, and are expected to be used as metal substitutes, etc. However, while polyimide resins have high heat resistance, they do not exhibit thermoplasticity and have the problem of poor moldability.

[0003] While high-temperature resistant resins such as Vesper (registered trademark) are known as polyimide molding materials (Patent Document 1), their extremely low fluidity even at high temperatures makes molding difficult, and the need to perform molding for long periods under high temperature and high pressure conditions is disadvantageous in terms of cost. In contrast, resins that have a melting point and fluidity at high temperatures, like crystalline resins, can be easily and inexpensively molded.

[0004] In recent years, thermoplastic polyimide resins have been reported. Thermoplastic polyimide resins possess not only the heat resistance inherent in polyimide resins but also excellent moldability. Therefore, thermoplastic polyimide resins can be used in molded articles that are used in harsh environments where general-purpose thermoplastic resins such as nylon and polyester could not be used.

[0005] Under these circumstances, thermoplastic polyimide resins that offer a good balance between moldability and heat resistance are being investigated (Patent Document 2). Furthermore, the process of fiberizing thermoplastic polyimide resins is also being investigated (Patent Document 3).

[0006] Japanese Patent Publication No. 2005-28524, International Publication No. 2016 / 147996, Japanese Patent Publication No. 2022-132199

[0007] If the thermoplastic polyimide resin fibers described above can be bundled together with continuous reinforcing fibers to form a blended yarn, it is expected that the range of applications for thermoplastic polyimide resin fibers will expand even further.

[0008] Here, when bundling thermoplastic polyimide resin fibers and continuous reinforcing fibers, one might consider using twisted or braided cords. However, using twisted or braided cords results in a loss of linearity in the continuous reinforcing fibers, leading to inferior strength in the resulting molded product.

[0009] Furthermore, while it is conceivable to use heat to bundle thermoplastic resin fibers and continuous reinforcing fibers, thermoplastic polyimide resin fibers tend to decompose easily in oxygen, so a method that can bundle them without heating is desirable.

[0010] Furthermore, even if thermoplastic resin fibers and continuous reinforcing fibers can be bundled together, if the inherent flexibility of the fiber bundle is lost, its usefulness will be halved.

[0011] The present invention aims to solve the above problems and to provide a blended yarn with excellent flexibility and strength in the fiber length direction of the continuous reinforced fibers, a method for manufacturing a molded product, and a method for manufacturing a blended yarn.

[0012] Based on the above problems, the inventors conducted research and found that the above problems can be solved by using continuous thermoplastic polyimide resin fibers with significantly finer fibers than continuous reinforcing fibers, and by intertwining at least a portion of the continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers at a rate of 1 to 500 locations per 500 meters.

[0013] Specifically, the above problem was solved by the following means: [1] A blended yarn containing continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers, wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fibers to the fineness of the continuous reinforcing fibers (fineness of continuous thermoplastic polyimide resin fibers / fineness of continuous reinforcing fibers) is 0.009 to 0.090, and the blended yarn is intertwined with at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers at a rate of 1 to 500 places per 500 m, and in the other portions, the continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers are parallel with linearity in the fiber length direction. [2] The blended yarn according to [1], wherein interlacing is formed with at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers. [3] The continuous thermoplastic polyimide resin fibers are a repeating structural unit represented by the following formula (1) and a repeating structural unit represented by the following formula (2): (R １ R is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. ２ X is a divalent, chain-like aliphatic group having 5 to 16 carbon atoms. １ and X ２ Each of these is independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.) The blended yarn according to [1] or [2] is a polyimide resin that contains the repeating structural units of formula (1) to the total of the repeating structural units of formula (2) and formula (1) is 20 mol% or more and less than 40 mol%, and satisfies the following conditions (a), (b), and (c). Condition (a): Melting point (Tm) is 280°C or more and 345°C or less Condition (b): Glass transition temperature (Tg) is 140°C or more and 200°C or less Condition (c): The amount of heat of the crystallization exothermic peak observed when cooled at a cooling rate of 20°C / min after melting, as measured by differential scanning calorimeter, is 17.0 mJ / mg or more [4] The R １ The blended yarn described in [3], wherein the divalent base is represented by the following formula (R1-1) or (R1-2). (m １１ and m １２ Each of these is an integer between 0 and 2, independently of the others.１３ to m １５ is, independently of each other, an integer of 0 to 2.) [5] The R １ is a divalent group represented by the following formula (R1-3), the conjugate fiber according to [3] or [4]. [6] The R ２ is an alkylene group having 7 to 12 carbon atoms, the conjugate fiber according to any one of [3] to [5]. [7] X １ and X ２ are, independently of each other, a tetravalent group represented by any one of the following formulas (X-1) to (X-4), the conjugate fiber according to any one of [3] to [6]. (R １１ to R １８ are, independently of each other, an alkyl group having 1 to 4 carbon atoms. p １１ to p １３ are, independently of each other, an integer of 0 to 2. p １４ p １５ p １６ and p １８ are, independently of each other, an integer of 0 to 3. p １７ is an integer of 0 to 4. L １１ to L １３Each of these is independently a single bond, an ether group, a carbonyl group, or an alkylene group having 1 to 4 carbon atoms.) [8] The blended yarn according to any one of [1] to [7], wherein the continuous reinforcing fiber comprises at least one selected from the group consisting of carbon fiber, glass fiber, and aramid fiber. [9] The blended yarn according to any one of [1] to [8], wherein the number average fiber length of the continuous reinforcing fiber is greater than 10 mm.

[10] The blended yarn according to any one of [1] to [9], wherein the fineness of the continuous thermoplastic polyimide resin fiber is 100 to 500 denier.

[11] The blended yarn according to any one of [1] to

[10] , for tailored fiber placement processing or braiding processing.

[12] A blended yarn according to any one of [1] to

[11] , wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fiber to the fineness of the continuous reinforcing fiber (fineness of the continuous thermoplastic polyimide resin fiber / fineness of the continuous reinforcing fiber) is 0.010 to 0.060.

[13] A blended yarn according to any one of [1] to

[12] , wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fiber to the fineness of the continuous reinforcing fiber (fineness of the continuous thermoplastic polyimide resin fiber / fineness of the continuous reinforcing fiber) is 0.010 to 0.060, and the fineness of the continuous thermoplastic polyimide resin fiber is 100 to 500 denier.

[14] The blended yarn according to any one of [1] to

[13] , wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fibers to the fineness of the continuous reinforcing fibers (fineness of the continuous thermoplastic polyimide resin fibers / fineness of the continuous reinforcing fibers) is 0.015 to 0.050, the blended yarn is intertwined with at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers at a rate of 1 to 90 places per 500 m, and the fineness of the continuous thermoplastic polyimide resin fibers is 110 to 350 denier.

[15] A method for manufacturing a molded article, comprising tailoring fiber placement processing or braiding processing of the blended yarn according to any one of [1] to

[14] .

[16] A method for producing a blended yarn, comprising interlacing a fiber bundle containing continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers, wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fibers to the fineness of the continuous reinforcing fibers (fineness of the continuous thermoplastic polyimide resin fibers / fineness of the continuous reinforcing fibers) is 0.009 to 0.090 at a rate of 1 to 500 locations per 500 m of the fiber bundle.

[17] The method for producing a blended yarn according to

[16] , wherein the blended yarn is the blended yarn according to any one of [1] to

[14] .

[0014] The present invention makes it possible to provide a blended yarn with excellent flexibility and strength in the fiber length direction of the continuous reinforced fibers, a method for manufacturing a molded product, and a method for manufacturing a blended yarn.

[0015] Figure 1 schematically shows the state of continuous reinforced fibers. Figure 2 schematically shows the state of continuous reinforced fibers after interlacing. Figure 3 schematically shows the state of entanglement between continuous reinforced fibers and continuous thermoplastic polyimide resin fibers in the blended yarn of the present invention.

[0016] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). Note that the following embodiment is illustrative for explaining the present invention, and the present invention is not limited to this embodiment.

[0017] In this specification, "~" is used to mean that the numerical values ​​before and after it are included as the lower and upper limits. Furthermore, the upper and lower limits of the numerical values ​​in this specification are given as examples of this embodiment, regardless of the combination of upper and lower limits.

[0018] In this specification, a preferred combination of embodiments is a more preferred embodiment.

[0019] In this specification, all physical properties and characteristic values ​​shall be those at 23°C unless otherwise specified.

[0020] In this specification, when groups (atomic groups) are not specified as substituted or unsubstituted, the notation includes both groups (atomic groups) with and without substituents. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups. In this specification, when notation is not specified as substituted or unsubstituted, unsubstituted is preferred.

[0021] Examples of substituents in this specification are preferably halogen atoms, cyano groups, nitro groups, hydroxyl groups, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, heterocyclic groups, heterocyclic oxy groups, alkenyl groups, alkylsulfanyl groups, arylsulfanyl groups, acyl groups, or amino groups; more preferably halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, alkenyl groups, or acyl groups; even more preferably alkyl groups, aryl groups, aryloxy groups, or alkenyl groups; and even more preferably alkyl groups. The formula weight of these substituents is preferably 15 or more, and preferably 200 or less. Formula weight refers to, for example, a methyl group (-CH ３ If so, the result is 15. These substituents may have further substituents, but it is preferable that they do not have substituents.

[0022] In this specification, the term "process" includes not only independent processes but also any process that cannot be clearly distinguished from other processes, as long as its intended function is achieved.

[0023] If the measurement methods, etc., described in the standards shown in this specification differ from year to year, unless otherwise specified, the standards as of January 1, 2024 shall apply. If the measurement methods, etc., described in the standards shown in this specification have been abolished as of January 1, 2024, the standards in effect at the time of abolition shall apply.

[0024] Figures 1-3 are schematic diagrams, and the scale and other aspects may not be consistent with reality.

[0025] The blended yarn of this embodiment is a blended yarn containing continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers, wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fibers to the fineness of the continuous reinforcing fibers (fineness of continuous thermoplastic polyimide resin fibers / fineness of continuous reinforcing fibers) is 0.009 to 0.090, and the blended yarn is characterized in that at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers are intertwined at a rate of 1 to 500 places per 500 m, and in the other portions, the continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers are arranged in parallel with linearity in the fiber length direction.

[0026] By adopting this configuration, a blended yarn with excellent flexibility and strength in the fiber length direction of the continuous reinforced fibers, a method for manufacturing molded products, and a method for manufacturing blended yarn can be obtained.

[0027] Blended yarns in which continuous thermoplastic resin fibers and continuous reinforcing fibers are highly dispersed in the fiber length direction are known as useful materials for tailored fiber placement (TFP) processing. However, if the fiber bundle consisting of continuous thermoplastic resin fibers and continuous reinforcing fibers is twisted, the linearity of the continuous reinforcing fibers is lost, resulting in inferior strength of the resulting molded product. Figure 1(a) schematically shows one continuous reinforcing fiber in a blended yarn with perfect linearity, and Figure 1(b) schematically shows one continuous reinforcing fiber when the fiber bundle is twisted. In Figure 1(a), the continuous reinforcing fiber maintains its linearity and exhibits excellent strength in the fiber length direction. In contrast, in Figure 1(b), the linearity of the continuous reinforcing fiber is lost, resulting in inferior strength in the fiber length direction.

[0028] On the other hand, interlacing is a known method for bundling fibers together (forming them into a single thread). Interlacing is a processing method in which high-pressure air is blown at regular intervals to entangle the fibers. Interlacing causes the fibers to intertwine at the points where air is blown, making it possible to bundle the fibers together. Figure 2 is a schematic diagram showing two continuous reinforcement fibers when a continuous reinforcement fiber bundle is interlaced. As shown in Figure 2, in interlaced fibers, the orientation of the fibers in the intertwined parts becomes random, and the linearity of the continuous reinforcement fibers tends to be further lost.

[0029] Under these circumstances, the inventors conducted an investigation and found that by arranging continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers in parallel in the longitudinal direction of the fibers, and using continuous thermoplastic polyimide resin fibers with a fineness considerably smaller than that of the continuous reinforcing fibers, and by intertwining at least a portion of the continuous thermoplastic polyimide resin fibers with at least a portion of the continuous reinforcing fibers at a predetermined frequency, a flexible blended yarn can be obtained while maintaining the linearity of the continuous reinforcing fibers. Figure 3 is a schematic diagram showing one continuous reinforcing fiber and two continuous thermoplastic polyimide resin fibers in the intertwined portion of the blended yarn of this embodiment. As shown in Figure 3, by using continuous thermoplastic polyimide resin fibers 2 with a finer fineness than that of the continuous reinforcing fibers 1, the linearity of the continuous reinforcing fibers 1 can be maintained to the maximum extent while intertwining with the continuous thermoplastic polyimide resin fibers 2. As a result, it was found that the continuous reinforcing fibers 1, which greatly affect the strength, have excellent linearity, and a bundled blended yarn can be obtained.

[0030] The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is merely one example of an embodiment of the present invention and is not limited to these.

[0031] In this embodiment, the blended yarn has a ratio of the fineness of the continuous thermoplastic polyimide resin fibers to the fineness of the continuous reinforcing fibers (fineness of continuous thermoplastic polyimide resin fibers / fineness of continuous reinforcing fibers) of 0.009 to 0.090. By using continuous thermoplastic polyimide resin fibers with a fineness significantly smaller than that of the continuous reinforcing fibers, even if at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers are intertwined in a part of the blended yarn, the linearity of the continuous reinforcing fibers can be maintained with almost no loss.

[0032] The fineness ratio (fineness of continuous thermoplastic polyimide resin fibers / fineness of continuous reinforcing fibers) is preferably 0.01 or higher (more specifically 0.010 or higher), more preferably 0.012 or higher, even more preferably 0.015 or higher, even more preferably 0.018 or higher, even more preferably 0.020 or higher, and also preferably 0.080 or lower, more preferably 0.070 or lower, even more preferably 0.060 or lower, even more preferably 0.050 or lower, even more preferably 0.040 or lower, even more preferably 0.035 or lower, and may also be 0.03 or lower. Setting it above the lower limit tends to improve the mixing of reinforcing fibers and resin fibers, resulting in even better TFP processability. Setting it below the upper limit tends to improve the impregnation of resin fibers into carbon fibers during molding, suppress the generation of voids, and further improve mechanical properties.

[0033] In this embodiment, the blended yarn is intertwined with at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers at a rate of 1 to 500 locations per 500 meters. This configuration allows the continuous thermoplastic polyimide resin fibers and the continuous reinforcing fibers to be bundled (integrated). In particular, it becomes possible to form a bundle without heating (for example, heating to a temperature of -10°C or higher, which is the glass transition temperature of the continuous thermoplastic polyimide resin fibers).

[0034] The frequency of the aforementioned entanglement is preferably one or more locations per 500m, more preferably two or more locations, even more preferably three or more locations, and also preferably 500 locations or less, preferably 400 locations or less, more preferably 90 locations or less, even more preferably 50 locations or less, even more preferably 30 locations or less, even more preferably 20 locations or less, and even more preferably 10 locations or less. Setting the frequency above the lower limit tends to improve the mixing of reinforcing fibers and resin fibers, resulting in even better TFP processability. Setting the frequency below the upper limit tends to maintain the linearity of the reinforcing fibers, preventing a decrease in the mechanical properties of the molded product.

[0035] In this embodiment, it is preferable that the entanglement of fibers occurs with random orientations in the length direction of the fibers in the entangled portions. In contrast, with twisting, all fibers in the entangled portions are circumferentially aligned in the same direction. Also, depending on the degree of twisting, the linearity of the fibers is usually lost.

[0036] It is preferable that interlacing is performed to form entanglement between at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers. Alternatively, entanglement can be formed by covering, or by methods such as wrapping thermoplastic resin fibers around the fiber bundles of continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers to integrate them.

[0037] In this embodiment, the blended yarn consists of continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers arranged in parallel with linearity in the fiber length direction, except for the entangled portions. This configuration yields a blended yarn that is flexible and has excellent strength.

[0038] Here, linearity means that the fiber length direction of the fibers is parallel to the fiber length direction of the blended yarn or deviates by ±3°. Therefore, forms that have linearity include the uninterlaced portion of the blended yarn in which the fibers in the blended yarn are arranged in parallel without substantially entanglement, and in which roving fibers are opened and bundled together and interlaced at a rate of 1 to 500 locations per 500m.

[0039] In this embodiment, it is preferable that the proportion of the blended yarn in which the continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers are arranged in parallel in a linear manner in the fiber length direction accounts for 80% or more of the fiber length of the blended yarn, more preferably 85% or more, even more preferably 90% or more, and even more preferably 95% or more, and the upper limit is preferably 99.9% or less.

[0040] In this embodiment, it is preferable that the blended yarn has a high degree of dispersion in the portion where the continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers are arranged in parallel with linearity in the fiber length direction. That is, when viewed from a cross section perpendicular to the fiber length direction of the blended yarn, it is preferable that the continuous thermoplastic resin fibers and continuous reinforcing fibers are evenly distributed, and that there are no regions with a relatively high concentration of resin components or regions with a relatively high concentration of reinforcing fibers.

[0041] A higher degree of dispersion results in a more flexible blended yarn. The degree of dispersion is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, even more preferably 80% or more, even more preferably 90% or more, and also 100% or less.

[0042] The degree of dispersion is measured according to the following method.

[0043] <<Method for Measuring Dispersion>> The blended yarn is embedded in epoxy resin, and a cross-section perpendicular to the longitudinal direction of the blended yarn is polished. The cross-sectional view is then photographed using a super-depth color 3D shape measuring microscope. In the captured image, six auxiliary lines are drawn radially at equal intervals, and the lengths of the continuous reinforcing fiber regions on each auxiliary line are measured as a1, a2, a3...ai (i=n). In addition, the lengths of the continuous thermoplastic polyimide resin fiber regions on each auxiliary line are measured as b1, b2, b3...bi (i=m). Based on these results, the dispersion is calculated using the following formula.

[0044]

[0045] For ultra-deep color 3D shape measuring microscopes, the VK-9500 (controller unit) / VK-9510 (measuring unit) (manufactured by Keyence) can be used.

[0046] <Continuous Thermoplastic Polyimide Resin Fibers> Continuous thermoplastic polyimide resin fibers contain thermoplastic polyimide resin.

[0047] Continuous thermoplastic polyimide resin fibers refer to thermoplastic polyimide resin fibers having an average fiber length of more than 6 mm, preferably having an average fiber length of more than 10 mm, more preferably having an average fiber length of more than 12 mm, even more preferably having an average fiber length of more than 30 mm, and even more preferably having an average fiber length of more than 10 cm. There are no particular restrictions on the average fiber length of the thermoplastic polyimide resin fibers used in this embodiment, but from the viewpoint of improving moldability, it is preferably 1 m or more, more preferably 100 m or more, even more preferably 1,000 m or more, and also preferably 20,000 m or less, more preferably 10,000 m or less, and even more preferably 7,000 m or less.

[0048] The fineness of the continuous thermoplastic polyimide resin fiber is preferably 90 denier or more, more preferably 100 denier or more, even more preferably 110 denier or more, even more preferably 120 denier or more, even more preferably 140 denier or more, and also preferably 500 denier or less, more preferably 450 denier or less, even more preferably 400 denier or less, even more preferably 350 denier or less, even more preferably 300 denier or less, and even more preferably 250 denier or less. Setting it above the lower limit tends to further improve the entanglement effect with the continuous reinforcing fiber. Also, setting it below the upper limit tends to increase the blending ratio of the continuous thermoplastic resin fiber and the continuous reinforcing fiber, further improving the suppression of voids in the molded product and the shortening of the impregnation time.

[0049] Continuous thermoplastic polyimide resin fibers consist of repeating structural units represented by the following formula (1) and the following formula (2):

[0050]

[0051] (R １ R is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. ２ X is a divalent, chain-like aliphatic group having 5 to 16 carbon atoms. １ and X ２ Each of these is independently a tetravalent group with 6 to 22 carbon atoms containing at least one aromatic ring.

[0052] Preferably, the polyimide resin (hereinafter sometimes referred to as "thermoplastic polyimide resin X") contains the following conditions: the content ratio of the repeating structural units of formula (1) to the total of the repeating structural units of formula (2) is 20 mol% or more and less than 40 mol%, and the polyimide resin satisfies the following conditions (a), (b), and (c).

[0053] Condition (a): The melting point (Tm) is between 280°C and 345°C. Condition (b): The glass transition temperature (Tg) is between 150°C and 200°C. Condition (c): Preferably, the amount of heat in the crystallization exothermic peak observed when cooled at a cooling rate of 20°C / min after melting, as measured by differential scanning calorimeter, is 17.0 mJ / mg or more.

[0054] The repeating structural units of equation (1) are described in detail below.

[0055] R １ This is a divalent group having 6 to 22 carbon atoms that contains at least one alicyclic hydrocarbon structure. Here, the alicyclic hydrocarbon structure refers to a ring derived from an alicyclic hydrocarbon compound, and the alicyclic hydrocarbon compound may be saturated or unsaturated, monocyclic or polycyclic.

[0056] Examples of alicyclic hydrocarbon structures include cycloalkane rings such as cyclohexane rings, cycloalkene rings such as cyclohexene, bicycloalkane rings such as norbornane rings, and bicycloalkene rings such as norbornene, but are not limited to these. Among these, cycloalkane rings are preferred, more preferably cycloalkane rings having 4 to 7 carbon atoms, and even more preferably cyclohexane rings.

[0057] R １ The carbon number is 6 to 22, preferably 8 to 17.

[0058] R １ It contains at least one alicyclic hydrocarbon structure, preferably 1 to 3.

[0059] R １ Preferably, it is a divalent group represented by the following formula (R1-1) or (R1-2).

[0060]

[0061] (m １１ and m １２ Each of these is an integer between 0 and 2, preferably 0 or 1. １３ ~m １５ Each of these is an integer between 0 and 2, preferably 0 or 1.

[0062] R １ Particularly preferred is a divalent group represented by the following formula (R1-3).

[0063]

[0064] In the divalent group represented by the above formula (R1-3), the positional relationship of the two methylene groups with respect to the cyclohexane ring may be cis or trans, and the ratio of cis to trans may be any value.

[0065] X １ This is a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring. The aromatic ring may be a monoring or a fused ring, and examples include, but is not limited to, a benzene ring, a naphthalene ring, anthracene ring, and a tetracene ring. Among these, a benzene ring and a naphthalene ring are preferred, and a benzene ring is more preferred.

[0066] X １ The carbon number is 6 to 22, preferably 6 to 18.

[0067] X １ It contains at least one aromatic ring, preferably 1 to 3.

[0068] X １ Preferably, it is a tetravalent group represented by any of the following formulas (X-1) to (X-4).

[0069]

[0070] (R １１ ~R １８ These are each independently alkyl groups having 1 to 4 carbon atoms. １１ ~p １３ Each of these is an integer between 0 and 2, preferably 0. １４ , p １５ , p １６ and p １８ Each of these is an integer between 0 and 3, preferably 0. １７ L is an integer between 0 and 4, preferably 0. １１ ~L １３These are, independently, a single bond, an ether group, a carbonyl group, or an alkylene group having 1 to 4 carbon atoms.

[0071] Note X １ Since is a tetravalent group with 6 to 22 carbon atoms containing at least one aromatic ring, R in formula (X-2) １２ , R １３ , p １２ and p １３ The tetravalent group represented by formula (X-2) is selected such that the number of carbon atoms falls within the range of 6 to 22.

[0072] Similarly, L in equation (X-3) １１ , R １４ , R １５ , p １４ and p １５ The number of carbon atoms in the tetravalent group represented by formula (X-3) is selected to fall within the range of 6 to 22, and L in formula (X-4) １２ , L １３ , R １６ , R １７ , R １８ , p １６ , p １７ and p １８ The tetravalent group represented by formula (X-4) is selected such that the number of carbon atoms falls within the range of 6 to 22.

[0073] X １ Particularly preferred is a tetravalent group represented by the following formula (X-5) or (X-6).

[0074]

[0075] Next, the repeating constituent units of equation (2) will be described in detail below.

[0076] R ２ The group is a divalent linear aliphatic group having 5 to 16 carbon atoms, preferably having 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms. Here, the linear aliphatic group means a group derived from a linear aliphatic compound, and the linear aliphatic compound may be saturated or unsaturated, linear or branched, and may contain heteroatoms such as oxygen atoms.

[0077] R ２The alkylene group is preferably a C5-C16 alkylene group, more preferably a C6-C14 alkylene group, even more preferably a C7-C12 alkylene group, and most preferably a C8-C10 alkylene group. The alkylene group may be a linear alkylene group or a branched alkylene group, but it is preferably a linear alkylene group.

[0078] R ２ The group is preferably at least one selected from an octamethylene group and a decamethylene group, and is particularly preferably an octamethylene group.

[0079] Also, R ２ Another preferred embodiment is a divalent linear aliphatic group having 5 to 16 carbon atoms containing an ether group. The number of carbon atoms is preferably 6 to 14, more preferably 7 to 12, and even more preferably 8 to 10. Among these, a divalent group represented by the following formula (R2-1) or (R2-2) is preferred.

[0080]

[0081] (m ２１ and m ２２ Each of these is an integer between 1 and 15, preferably between 1 and 13, more preferably between 1 and 11, and even more preferably between 1 and 9. ２３ ~m ２５ Each of these is an integer between 1 and 14, preferably between 1 and 12, more preferably between 1 and 10, and even more preferably between 1 and 8.

[0082] Note R ２ Since is a divalent linear aliphatic group having 5 to 16 carbon atoms (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms), m in formula (R2-1) ２１ and m ２２ The carbon atoms of the divalent group represented by formula (R2-1) are selected to be in the range of 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, and even more preferably 8 to 10 carbon atoms). That is, m ２１ +m ２２is 5 to 16 (preferably 6 to 14, more preferably 7 to 12, still more preferably 8 to 10).

[0083] Similarly, m in formula (R2-2) ２３ ~m ２５ is selected so that the number of carbon atoms of the divalent group represented by formula (R2-2) falls within the range of 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, still more preferably 8 to 10 carbon atoms). That is, m ２３ +m ２４ +m ２５ is 5 to 16 (preferably 6 to 14 carbon atoms, more preferably 7 to 12 carbon atoms, still more preferably 8 to 10 carbon atoms).

[0084] X ２ is defined in the same manner as X in formula (1) １ and the preferred embodiments are also the same.

[0085] The content ratio of the repeating structural unit of formula (1) to the total of the repeating structural units of formula (1) and the repeating structural unit of formula (2) is preferably 20 mol% or more and less than 40 mol%. When the content ratio is 20 mol% or more, the molding processability tends to improve. Further, by setting the content ratio to less than 40 mol%, the heat amount of the crystallization exothermic peak (hereinafter also referred to as "crystallization heat amount") increases, so the heat resistance tends to improve.

[0086] From the viewpoint of molding processability, the content ratio of the repeating structural unit of formula (1) to the total of the repeating structural units of formula (1) and the repeating structural unit of formula (2) is preferably 25 mol% or more, more preferably 30 mol% or more, still more preferably 32 mol% or more. From the viewpoint of increasing the crystallization heat amount, that is, improving the heat resistance, it is preferably 38 mol% or less, more preferably 36 mol% or less, still more preferably 35 mol% or less.

[0087] The content ratio of the total of the repeating structural units of formula (1) and the repeating structural unit of formula (2) to all the repeating units constituting the thermoplastic polyimide resin X is preferably 50 to 100 mol%, more preferably 75 to 100 mol%, still more preferably 80 to 100 mol%, and even more preferably 85 to 100 mol%.

[0088] The thermoplastic polyimide resin X may further contain a repeating structural unit of the following formula (3). In that case, the content ratio of the repeating structural unit of formula (3) to the total of the repeating structural unit of formula (1) and the repeating structural unit of formula (2) is preferably 25 mol% or less. On the other hand, the lower limit is not particularly limited and may exceed 0 mol%.

[0089] From the viewpoint of improving heat resistance, the content ratio is preferably 5 mol% or more, more preferably 10 mol% or more. On the other hand, from the viewpoint of maintaining crystallinity, it is preferably 20 mol% or less, more preferably 15 mol% or less.

[0090]

[0091] (R ３ is a divalent group having 6 to 22 carbon atoms containing at least one aromatic ring. X ３ is a tetravalent group having 6 to 22 carbon atoms containing at least one aromatic ring.)

[0092] R ３ is a divalent group having 6 to 22 carbon atoms containing at least one aromatic ring. The aromatic ring may be a monocyclic ring or a condensed ring, and examples include a benzene ring, a naphthalene ring, an anthracene ring, and a tetracene ring, but are not limited thereto. Among these, a benzene ring and a naphthalene ring are preferable, and a benzene ring is more preferable.

[0093] R ３ has 6 to 22 carbon atoms, preferably 6 to 18 carbon atoms.

[0094] R ３ contains at least one aromatic ring, preferably 1 to 3 aromatic rings.

[0095] Further, a monovalent or divalent electron-withdrawing group may be bonded to the aromatic ring. Examples of the monovalent electron-withdrawing group include a nitro group, a cyano group, a p-toluenesulfonyl group, a halogen, a halogenated alkyl group, a phenyl group, an acyl group, etc. Examples of the divalent electron-withdrawing group include an alkylene fluoride group (e.g., -C(CF ３ ), - (CF ２ ), - (CF ２ ), - (CF ｐIn addition to halogenated alkylene groups such as -CO- and -SO- (where p is an integer from 1 to 10), there are also -CO- and -SO- ２ Examples include -, -SO-, -CONH-, and -COO-.

[0096] R ３ Preferably, it is a divalent group represented by the following formula (R3-1) or (R3-2).

[0097]

[0098] (m ３１ and m ３２ Each of these is an integer between 0 and 2, preferably 0 or 1. ３３ and m ３４ Each of these is an integer between 0 and 2, preferably 0 or 1. ２１ , R ２２ , and R ２３ These are, independently, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an alkynyl group having 2 to 4 carbon atoms. ２１ , p ２２ and p ２３ L is an integer between 0 and 4, preferably 0. ２１ (These are single bonds, ether groups, carbonyl groups, or alkylene groups having 1 to 4 carbon atoms.)

[0099] Note R ３ Since is a divalent group with 6 to 22 carbon atoms containing at least one aromatic ring, m in formula (R3-1) ３１ , m ３２ , R ２１ and p ２１ The divalent group represented by formula (R3-1) is selected such that the number of carbon atoms falls within the range of 6 to 22.

[0100] Similarly, L in equation (R3-2) ２１ , m ３３ , m ３４ , R ２２ , R ２３ , p ２２ and p ２３ The divalent group represented by formula (R3-2) is selected such that the number of carbon atoms falls within the range of 12 to 22.

[0101] X ３ This is X in equation (1). １ It is defined similarly, and the preferred mode is also defined similarly.

[0102] The content ratio of the repeating structural unit of formula (3) to the total repeating structural units constituting the thermoplastic polyimide resin X is preferably 25 mol% or less. On the other hand, there is no particular lower limit, and it is sufficient if it is greater than 0 mol%.

[0103] From the viewpoint of improving heat resistance, the aforementioned content ratio is preferably 5 mol% or more, more preferably 7 mol% or more, while from the viewpoint of maintaining crystallinity, it is preferably 20 mol% or less, more preferably 15 mol% or less.

[0104] The thermoplastic polyimide resin X may further contain repeating structural units represented by the following formula (4).

[0105]

[0106] (R ４ Ha-SO ２ - or Si(R ｘ ) (Caution ｙ ) A divalent group containing O-, R ｘ and R ｙ Each of these independently represents a chain-like aliphatic group or a phenyl group having 1 to 3 carbon atoms. ４ (It is a tetravalent group with 6 to 22 carbon atoms that contains at least one aromatic ring.)

[0107] X ４ This is X in equation (1). １ It is defined similarly, and the preferred mode is also defined similarly.

[0108] There are no particular restrictions on the terminal structure of the thermoplastic polyimide resin X, but it is preferable that it has a chain-like aliphatic group having 5 to 14 carbon atoms at the end.

[0109] The aforementioned chain-like aliphatic group may be saturated or unsaturated, and may be linear or branched. When the thermoplastic polyimide resin X has the above-mentioned specific group at its terminals, it exhibits excellent heat aging resistance.

[0110] Examples of saturated chain aliphatic groups having 5 to 14 carbon atoms include n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, lauryl group, n-tridecyl group, n-tetradecyl group, isopentyl group, neopentyl group, 2-methylpentyl group, 2-methylhexyl group, 2-ethylpentyl group, 3-ethylpentyl group, isooctyl group, 2-ethylhexyl group, 3-ethylhexyl group, isononyl group, 2-ethyloctyl group, isodecyl group, isododecyl group, isotridecyl group, isotetradecyl group, and so on.

[0111] Examples of unsaturated linear aliphatic groups having 5 to 14 carbon atoms include 1-pentenyl group, 2-pentenyl group, 1-hexenyl group, 2-hexenyl group, 1-heptenyl group, 2-heptenyl group, 1-octenyl group, 2-octenyl group, decenyl group, dodecenyl group, tridecenyl group, and tetradecenyl group.

[0112] In particular, the above-mentioned linear aliphatic group is preferably a saturated linear aliphatic group, and more preferably a saturated linear aliphatic group. Furthermore, from the viewpoint of obtaining heat aging resistance, the above-mentioned linear aliphatic group preferably has 6 or more carbon atoms, more preferably 7 or more carbon atoms, even more preferably 8 or more carbon atoms, preferably 12 or fewer carbon atoms, more preferably 10 or fewer carbon atoms, and even more preferably 9 or fewer carbon atoms. The above-mentioned linear aliphatic group may be just one type or two or more types.

[0113] The above-mentioned linear aliphatic group is particularly preferably at least one selected from n-octyl group, isooctyl group, 2-ethylhexyl group, n-nonyl group, isononyl group, n-decyl group, and isodecyl group; more preferably at least one selected from n-octylamine, isooctylamine, 2-ethylhexylamine, n-nonylamine, and isononylamine; and most preferably at least one selected from n-octyl group, isooctyl group, and 2-ethylhexyl group.

[0114] Furthermore, from the viewpoint of heat aging resistance, it is preferable that the thermoplastic polyimide resin X has only linear aliphatic groups having 5 to 14 carbon atoms at its ends, in addition to terminal amino groups and terminal carboxyl groups. If other groups are present at the ends, their content is preferably 10 mol% or less, more preferably 5 mol% or less, relative to the linear aliphatic groups having 5 to 14 carbon atoms.

[0115] From the viewpoint of exhibiting excellent heat aging resistance, the content of the chain-like aliphatic groups having 5 to 14 carbon atoms in the thermoplastic polyimide resin X is preferably 0.01 mol% or more, more preferably 0.1 mol% or more, and even more preferably 0.2 mol% or more, based on 100 mol% of the total repeating structural units in the thermoplastic polyimide resin X. Furthermore, in order to ensure a sufficient molecular weight and obtain good mechanical properties, the content of the chain-like aliphatic groups having 5 to 14 carbon atoms in the thermoplastic polyimide resin X is preferably 10 mol% or less, more preferably 6 mol% or less, and even more preferably 3.5 mol% or less, based on 100 mol% of the total repeating structural units in the thermoplastic polyimide resin X.

[0116] The content of the above-mentioned chain-like aliphatic groups having 5 to 14 carbon atoms in the thermoplastic polyimide resin X can be determined by depolymerizing the thermoplastic polyimide resin X.

[0117] The thermoplastic polyimide resin X is further characterized by satisfying the following conditions (a), (b), and (c).

[0118] Condition (a): Melting point (Tm) is 280°C or higher and 345°C or lower. Condition (b): Glass transition temperature (Tg) is 140°C or higher and 200°C or lower. Condition (c): The amount of heat from the crystallization exothermic peak observed when cooled at a rate of 20°C / min after melting, as measured by differential scanning calorimeter, is 17.0 mJ / mg or higher. Thermoplastic polyimide resin X satisfies all of the above conditions (a) to (c) to achieve a good balance between moldability and heat resistance.

[0119] Furthermore, in general, crystalline resins with a high degree of crystallinity, i.e., those with a high heat generation during crystallization, exhibit good fluidity when heated above their melting point, resulting in improved moldability. Generally, the crystalline portion of a crystalline resin melts when heated above its melting point, causing a rapid decrease in viscosity. Therefore, resins with a higher crystalline portion exhibit improved fluidity at temperatures above their melting point. In other words, a thermoplastic polyimide resin X that satisfies both conditions (a) and (c) will also have good moldability.

[0120] Regarding condition (a), the melting point (Tm) of the thermoplastic polyimide resin X is preferably 280°C or higher, more preferably 290°C or higher, and even more preferably 300°C or higher, from the viewpoint of exhibiting heat resistance, and preferably 345°C or lower, more preferably 340°C or lower, even more preferably 335°C or lower, and even more preferably 330°C or lower, from the viewpoint of exhibiting high moldability. If the melting point (Tm) of the thermoplastic polyimide resin X is less than 280°C, the heat resistance is insufficient, and if it exceeds 345°C, the moldability is insufficient.

[0121] Regarding condition (b), the glass transition temperature (Tg) of the thermoplastic polyimide resin X is preferably 140°C or higher, more preferably 150°C or higher, and even more preferably 153°C or higher, from the viewpoint of heat resistance. In other words, the glass transition temperature (Tg) of the thermoplastic polyimide resin X is preferably 160°C or higher, more preferably 170°C or higher, and even more preferably 180°C or higher, and from the viewpoint of exhibiting high moldability, it is preferably 195°C or lower, more preferably 190°C or lower, and even more preferably 185°C or lower. Setting the glass transition temperature (Tg) of the polyimide resin to 140°C or higher tends to further improve heat resistance.

[0122] The melting point and glass transition temperature of the thermoplastic polyimide resin X can both be measured using a differential scanning calorimeter, and specifically, they can be measured by the method described in the examples.

[0123] Furthermore, regarding condition (c), the amount of heat generated during crystallization observed when the thermoplastic polyimide resin X is melted and then cooled at a cooling rate of 20°C / min is measured using a differential scanning calorimeter. Specifically, the thermoplastic polyimide resin X is sampled, heated at a constant rate using a differential scanning calorimeter, and the thermoplastic polyimide resin X is melted once. Then, the amount of heat generated during crystallization is calculated from the area of ​​the crystallization heat generated peak observed when the resin is cooled at a predetermined cooling rate.

[0124] In the thermoplastic polyimide resin X, it is preferable that the crystallization heat generation amount is 17.0 mJ / mg or more. Setting the crystallization heat generation amount to 17.0 mJ / mg or more tends to further improve heat resistance. The crystallization heat generation amount is preferably 18.0 mJ / mg or more, and more preferably 18.5 mJ / mg or more. The upper limit of the crystallization heat generation amount is not particularly limited, but is usually 45.0 mJ / mg or less.

[0125] The exothermic charge of crystallization can be measured specifically by the method described in the examples.

[0126] The logarithmic viscosity of a 5% by mass concentrated sulfuric acid solution of thermoplastic polyimide resin X at 30°C is preferably in the range of 0.2 to 2.0 dL / g, more preferably in the range of 0.3 to 1.8 dL / g. If the logarithmic viscosity is 0.2 dL / g or higher, sufficient mechanical strength can be obtained when a molded article is formed, and if it is 2.0 dL / g or lower, good moldability and handling properties are obtained. The logarithmic viscosity μ is determined by measuring the flow time of the concentrated sulfuric acid and the above thermoplastic polyimide resin X solution at 30°C using a Cannon-Fenske viscometer, and is calculated from the following formula.

[0127] μ = ln(ts / t) ０ ) / C t ０ : Flow time of concentrated sulfuric acid ts: Flow time of thermoplastic polyimide resin X solution C: 0.5 (g / dL) A known method can be used to produce thermoplastic polyimide resin X. For example, refer to paragraphs 0060-0078 of International Publication No. 2016 / 147996, which are incorporated herein by reference.

[0128] The thermoplastic polyimide resin fiber may or may not contain components other than the thermoplastic polyimide resin (preferably thermoplastic polyimide resin X).

[0129] Other components may include thermoplastic resins other than thermoplastic polyimide resin, stabilizers such as antioxidants and heat stabilizers, hydrolysis resistance improvers, weather resistance stabilizers, matting agents, ultraviolet absorbers, nucleating agents, plasticizers, dispersants, flame retardants, antistatic agents, color inhibitors, gelation inhibitors, colorants, mold release agents, and other additives. Details of these can be found in paragraphs 0130 to 0155 of Japanese Patent No. 4894982 and paragraphs 0047 to 0103 of International Publication No. 2021 / 241471, the contents of which are incorporated herein by reference.

[0130] The content of components other than thermoplastic polyimide resin in these continuous thermoplastic polyimide resin fibers is preferably less than 10% by mass, more preferably less than 5% by mass, even more preferably less than 3% by mass, and most preferably less than 1% by mass.

[0131] Continuous thermoplastic polyimide resin fibers may be surface-treated with a surface treatment agent.

[0132] The continuous thermoplastic polyimide resin fibers may or may not be stretched. In this embodiment, it is preferable that they are not stretched. Not stretching allows for a blended yarn with superior flexibility.

[0133] <Continuous Reinforcement Fibers> The blended yarn of this embodiment includes continuous reinforcement fibers. Continuous reinforcement fibers refer to reinforcement fibers with an average fiber length of more than 6 mm, preferably with an average fiber length of more than 10 mm, more preferably with an average fiber length of more than 12 mm, even more preferably with an average fiber length of more than 30 mm, and even more preferably with an average fiber length of more than 10 cm. There are no particular restrictions on the average fiber length of the continuous reinforcement fibers used in this embodiment, but from the viewpoint of improving moldability, it is preferably 1 m or more, more preferably 100 m or more, even more preferably 1,000 m or more, and also preferably 20,000 m or less, more preferably 10,000 m or less, and even more preferably 7,000 m or less.

[0134] Examples of continuous reinforcing fibers include inorganic fibers such as carbon fibers, glass fibers, metal fibers, boron fibers, basalt fibers, and ceramic fibers; and organic fibers such as aramid fibers, polyoxymethylene fibers, aromatic polyamide fibers, poly(p-phenylenebenzobisoxazole) fibers, and ultra-high molecular weight polyethylene fibers. Among these, it is preferable to include at least one selected from the group consisting of carbon fibers, glass fibers, and aramid fibers, with carbon fibers and / or glass fibers being more preferable, and carbon fibers being even more preferable.

[0135] Examples of carbon fibers include polyacrylonitrile-based carbon fibers and pitch-based carbon fibers.

[0136] As glass fibers, commonly used are those obtained by melt-spinning glass such as E glass, C glass, A glass, S glass, and alkali-resistant glass.

[0137] The continuous reinforcing fibers may be surface-treated with a surface treatment agent.

[0138] The cross-section of the continuous reinforcing fiber may be either circular or non-circular.

[0139] In addition to the above, the description in paragraph 0074 of Japanese Patent No. 7398028 can be given to continuous carbon fibers, and this content is incorporated herein by reference.

[0140] For continuous reinforcement fibers, carbon fibers are preferably tensile strength of 1500 MPa or more, more preferably 2500 MPa or more, and even more preferably 3500 MPa or more. There is no particular upper limit, but it is practical to keep it at 8000 MPa or less. For glass fibers, the tensile strength is preferably 800 MPa or more, more preferably 1800 MPa or more, and even more preferably 2800 MPa or more. There is no particular upper limit, but it is practical to keep it at 5000 MPa or less.

[0141] The blended yarn of this embodiment preferably contains 1,000 to 100,000 (preferably 5,000 to 50,000) continuous reinforcing fibers per strand.

[0142] Furthermore, the proportion of continuous reinforcing fibers in the blended yarn of this embodiment is preferably 20% by volume or more, more preferably 30% by volume or more, preferably 80% by volume or less, and more preferably 70% by volume or less.

[0143] <Other Components> The blended yarn of this embodiment may or may not contain other components other than continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers.

[0144] Other components that can be added include thermoplastic resins other than thermoplastic polyimide resin, fillers other than continuous reinforcing fibers, nucleating agents, stabilizers such as antioxidants and heat stabilizers, hydrolysis resistance improvers, weather resistance stabilizers, matting agents, ultraviolet absorbers, nucleating agents, plasticizers, dispersants, flame retardants, antistatic agents, coloring inhibitors, gelation inhibitors, colorants, mold release agents, and other additives. Details of these can be found in paragraphs 0130 to 0155 of Japanese Patent No. 4894982 and paragraphs 0047 to 0103 of International Publication No. 2021 / 241471, the contents of which are incorporated herein by reference.

[0145] The content of these other components is preferably less than 10% by mass of the blended yarn, more preferably less than 5% by mass, even more preferably less than 3% by mass, and even more preferably less than 1% by mass.

[0146] The blended yarn of this embodiment is typically manufactured using a continuous thermoplastic polyimide resin fiber bundle and a continuous reinforcing fiber bundle. The total ratio of the continuous thermoplastic polyimide resin fiber bundle and the continuous reinforcing fiber bundle in the blended yarn of this embodiment is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 97% by mass or more, and may be 99% by mass or more, or 100% by mass or less. The blended yarn of this embodiment preferably does not contain a sizing agent for bundling the continuous thermoplastic polyimide resin fibers and the continuous reinforcing fibers.

[0147] More specifically, the blended yarn is a fiber bundle containing continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers, wherein the ratio of the fineness of the continuous thermoplastic polyimide fibers to the fineness of the continuous reinforcing fibers (fineness of continuous thermoplastic polyimide fibers / fineness of continuous reinforcing fibers) is 0.009 to 0.090, and the fiber bundle is manufactured by a manufacturing method that includes interlacing the fiber bundle at a rate of 1 to 500 locations per 500 meters.

[0148] In the manufacturing method of the blended yarn of this embodiment, it becomes possible to form bundles without heating (for example, heating to a temperature of -10°C or higher than the glass transition temperature of the continuous thermoplastic polyimide resin fiber, or even heating to a temperature higher than the glass transition temperature of the continuous thermoplastic polyimide resin fiber).

[0149] In the method for producing the blended yarn of this embodiment, it is preferable to perform interlacing while the continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers are highly dispersed. A higher degree of dispersion results in a more flexible blended yarn. The degree of dispersion is preferably 50% or more, more preferably 60% or more, even more preferably 70% or more, even more preferably 80% or more, even more preferably 90% or more, and also 100% or less.

[0150] It is preferable to use continuous reinforcing fibers and / or continuous thermoplastic polyimide resin fibers that have been surface-treated with a treatment agent for use in blended yarns. This configuration makes it easier to obtain blended yarns in which the continuous reinforcing fibers and continuous thermoplastic polyimide resin fibers are more uniformly dispersed, and also improves the impregnation rate of the continuous thermoplastic polyimide resin fiber component into the continuous reinforcing fibers after molding. Further details of other blended yarns and methods for producing them can be found in paragraphs 0018 to 0039 of International Publication No. 2016 / 159340 and paragraph 0051 of Japanese Patent Application Publication No. 2020-063342, the contents of which are incorporated herein by reference.

[0151] The blended yarn of this embodiment is preferably used for tailored fiber placement (TFP) processing or braiding. Furthermore, the blended yarn of this embodiment is preferably used in applications involving yarn winding, such as braiding machines, knitting machines, and weaving machines.

[0152] Specifically, examples include tailored fiber-placement processed products using the blended yarn of this embodiment, woven fabrics formed from the blended yarn of this embodiment, and knitted fabrics formed from the blended yarn of this embodiment. Furthermore, examples of applications including yarn winding in this embodiment include braided cords and twisted cords.

[0153] The molded product of this embodiment is preferably manufactured by tailoring fiber placement or braiding the blended yarn of this embodiment.

[0154] Furthermore, it is preferable that the molded product of this embodiment is formed by heat processing of the blended yarn.

[0155] Furthermore, the molded product of this embodiment can also be formed by heat processing a tailored fiber placement product of blended yarn.

[0156] The molded products obtained from the blended yarn of this embodiment are not particularly limited and can be widely used in automobiles, aircraft and other transport equipment parts, general machine parts, precision machine parts, electronic and electrical equipment parts, office automation equipment parts, building materials and housing equipment related parts, medical devices, leisure and sports goods, toys, medical supplies, daily necessities such as food packaging films, defense and aerospace products, etc. In particular, it is suitably used as a molding material for medical orthotics (such as long leg orthoses), window frames for automobiles, trains and ships, goggle frames for helmets, eyeglass frames, safety shoes, etc. Furthermore, the blended yarn of this embodiment is suitable for manufacturing molded products having recesses and protrusions.

[0157] The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, processing content, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[0158] If the measuring instruments used in the examples are difficult to obtain due to discontinuation or other reasons, measurements can be taken using other instruments with equivalent performance.

[0159] <Melting point (Tm), glass transition temperature (Tg), crystallization temperature (Tc), and heat of crystallization> The melting point (Tm), glass transition temperature (Tg), crystallization temperature (Tc), and heat of crystallization of the polyimide resin were measured using a differential scanning calorimeter.

[0160] Specifically, the polyimide resin was subjected to the following thermal history under a nitrogen atmosphere. The thermal history consisted of a first heating cycle (heating rate 10°C / min), followed by cooling (cooling rate 20°C / min), and then a second heating cycle (heating rate 10°C / min).

[0161] The melting point was determined by reading the peak value of the endothermic peak observed during the second heating cycle. The glass transition temperature was determined by reading the value observed during the second heating cycle. The crystallization temperature was determined by reading the peak value of the exothermic peak observed during cooling.

[0162] The exothermic reaction (mJ / mg) was calculated from the area of ​​the exothermic reaction peak observed during the cooling process described above.

[0163] The differential scanning calorimeter used was the "DSC-6220" manufactured by SII Nanotechnology Co., Ltd.

[0164] <Semi-crystallization time> The semi-crystallization time of polyimide resin was measured using a differential scanning calorimeter (DSC-6220, manufactured by SII Nanotechnology Co., Ltd.).

[0165] For polyimide resins with a semi-crystallization time of 20 seconds or less, the measurement conditions were determined by holding the polyimide resin at its melting point + 20°C for 10 minutes under a nitrogen atmosphere to completely melt it, followed by a rapid cooling operation at a cooling rate of 70°C / min. The time taken from the appearance of the observed crystallization exothermic peak to reaching the peak top was then calculated.

[0166] In Table 1, polyimide resins with a semi-crystallization time of less than 20 seconds are indicated as "20>".

[0167] <Infrared Spectroscopic Analysis (IR Measurement)> IR measurements of polyimide resin were performed using the "JIR-WINSPEC50" manufactured by JEOL Ltd.

[0168] <Method for calculating resin fiber fineness / carbon fiber fineness> The ratio of the fineness of the continuous thermoplastic polyimide resin fiber to the fineness of the continuous reinforcing fiber (fineness of continuous thermoplastic polyimide resin fiber / fineness of continuous reinforcing fiber) was calculated from the fineness of the resin fiber bundle / fineness of the carbon fiber bundle.

[0169] In Example 1, described later, the fineness of the resin fiber is 210d = 23.3 tex, and the fineness of the carbon fiber is 800 tex, so the ratio of resin fineness to carbon fineness is 23.3 / 800 ≈ 0.029.

[0170] [Synthesis Example 1] Production of Polyimide Resin 1 A Dean-Stark apparatus, Liebig condenser, thermocouple, and four-paddle blade were installed in a 2 L separable flask. 600 g of 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Emulsifier Co., Ltd.) and 218.58 g (1.00 mol) of pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were introduced, and after nitrogen flow, the mixture was stirred at 150 rpm until a homogeneous suspension solution was obtained. Meanwhile, in a 500 mL beaker, 49.42 g (0.347 mol) of 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 93.16 g (0.645 mol) of 1,8-octamethylenediamine (manufactured by Kanto Chemical Co., Ltd.) were dissolved in 250 g of 2-(2-methoxyethoxy)ethanol to prepare a mixed diamine solution. This mixed diamine solution was gradually added using a plunger pump. During the dropwise addition of the mixed diamine solution, a nitrogen flow was maintained throughout, and the impeller speed was set to 250 rpm. After the dropwise addition was complete, 130 g of 2-(2-methoxyethoxy)ethanol and 1.934 g (0.0149 mol) of n-octylamine (manufactured by Kanto Chemical Co., Ltd.), a terminal encapsulant, were added and the mixture was further stirred. At this stage, a pale yellow polyamic acid solution was obtained. Next, the stirring speed was increased to 200 rpm, and the polyamic acid solution in the 2 L separable flask was heated to 190°C. During the heating process, precipitation of polyimide resin powder and dehydration due to imidization were observed between 120 and 140°C. After holding at 190°C for 30 minutes, the mixture was allowed to cool to room temperature and filtered. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180°C for 10 hours to obtain 316 g of polyimide resin 1 powder.

[0171] The above measurements and evaluations were performed using the obtained polyimide resin 1. The results are shown in Table 1. When the IR spectrum of polyimide resin 1 was measured, the following values ​​were obtained: ν(C=O) 1768, 1697 (cm²). －１ Characteristic absorption of the imide ring was observed in the following region.

[0172] [Synthesis Example 2] Production of Polyimide Resin 2 500 g of 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Emulsifier Co., Ltd.) and 109.06 g (0.500 mol) of pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were introduced into a 2 L separable flask equipped with a Dean-Stark apparatus, Liebig condenser, thermocouple, and four paddle blades. After nitrogen flow, the mixture was stirred at 150 rpm to obtain a homogeneous suspension solution. Meanwhile, in a 500 mL beaker, 21.18 g (0.149 mol) of 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 50.12 g (0.347 mol) of 1,8-octamethylenediamine (manufactured by Kanto Chemical Co., Ltd.) were dissolved in 200 g of 2-(2-methoxyethoxy)ethanol to prepare a mixed diamine solution. This mixed diamine solution was gradually added using a plunger pump. During the dropwise addition of the mixed diamine solution, a nitrogen flow was maintained throughout, and the impeller speed was set to 250 rpm. After the dropwise addition was complete, 100 g of 2-(2-methoxyethoxy)ethanol and 0.966 g (0.00744 mol) of n-octylamine (manufactured by Kanto Chemical Co., Ltd.), which is a terminal encapsulant, were added and the mixture was further stirred. At this stage, a pale yellow polyamic acid solution was obtained. Next, the stirring speed was set to 200 rpm, and the polyamic acid solution in the 2 L separable flask was heated to 190°C. During the heating process, precipitation of polyimide resin powder and dehydration due to imidization were observed between 120 and 140°C. After holding at 190°C for 30 minutes, the mixture was allowed to cool to room temperature and filtered. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180°C for 10 hours to obtain 158 g of polyimide resin 2 powder.

[0173] The above measurements and evaluations were performed using the obtained polyimide resin 2. The results are shown in Table 1. When the IR spectrum of polyimide resin 2 was measured, the following values ​​were obtained: ν(C=O) 1768, 1697 (cm²). －１ Characteristic absorption of the imide ring was observed in the following region.

[0174] [Synthesis Example 3] Production of Polyimide Resin 3 In a 2 L separable flask equipped with a Dean-Stark apparatus, Liebig condenser, thermocouple, and four-paddle blades, 500 g of 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Emulsifier Co., Ltd.) and 109.06 g (0.500 mol) of pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were introduced. After nitrogen flow, the mixture was stirred at 150 rpm until a homogeneous suspension solution was obtained. Meanwhile, in a 500 mL beaker, 17.65 g (0.124 mol) of 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 53.70 g (0.372 mol) of 1,8-octamethylenediamine (manufactured by Kanto Chemical Co., Ltd.) were dissolved in 200 g of 2-(2-methoxyethoxy)ethanol to prepare a mixed diamine solution. This mixed diamine solution was gradually added using a plunger pump. During the dropwise addition of the mixed diamine solution, a nitrogen flow was maintained throughout, and the impeller speed was set to 250 rpm. After the dropwise addition was complete, 100 g of 2-(2-methoxyethoxy)ethanol and 0.966 g (0.00744 mol) of n-octylamine (manufactured by Kanto Chemical Co., Ltd.), which is a terminal encapsulant, were added and the mixture was further stirred. At this stage, a pale yellow polyamic acid solution was obtained. Next, the stirring speed was set to 200 rpm, and the polyamic acid solution in the 2 L separable flask was heated to 190°C. During the heating process, precipitation of polyimide resin powder and dehydration due to imidization were observed between 120 and 140°C. After holding at 190°C for 30 minutes, the mixture was allowed to cool to room temperature and filtered. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180°C for 10 hours to obtain 160 g of polyimide resin 3 powder.

[0175] The above measurements and evaluations were performed using the obtained polyimide resin 3. The results are shown in Table 1. When the IR spectrum of polyimide resin 3 was measured, the following values ​​were obtained: ν(C=O) 1768, 1697 (cm²). －１ Characteristic absorption of the imide ring was observed in the following region.

[0176] [Synthesis Example 4] Production of Polyimide Resin 4 In a 2 L separable flask equipped with a Dean-Stark apparatus, Liebig condenser, thermocouple, and four-paddle blades, 500 g of 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Emulsifier Co., Ltd.) and 109.06 g (0.500 mol) of pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were introduced, and after nitrogen flow, the mixture was stirred at 150 rpm until a homogeneous suspension solution was obtained. Meanwhile, in a 500 mL beaker, 14.12 g (0.0993 mol) of 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 57.27 g (0.397 mol) of 1,8-octamethylenediamine (manufactured by Kanto Chemical Co., Ltd.) were dissolved in 200 g of 2-(2-methoxyethoxy)ethanol to prepare a mixed diamine solution. This mixed diamine solution was gradually added using a plunger pump. During the dropwise addition of the mixed diamine solution, a nitrogen flow was maintained throughout, and the impeller speed was set to 250 rpm. After the dropwise addition was complete, 100 g of 2-(2-methoxyethoxy)ethanol and 0.966 g (0.00744 mol) of n-octylamine (manufactured by Kanto Chemical Co., Ltd.), which is a terminal encapsulant, were added and the mixture was further stirred. At this stage, a pale yellow polyamic acid solution was obtained. Next, the stirring speed was set to 200 rpm, and the polyamic acid solution in the 2 L separable flask was heated to 190°C. During the heating process, precipitation of polyimide resin powder and dehydration due to imidization were observed between 120 and 140°C. After holding at 190°C for 30 minutes, the mixture was allowed to cool to room temperature and filtered. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180°C for 10 hours to obtain 158 g of polyimide resin 4 powder.

[0177] When the IR spectrum of polyimide resin 4 was measured, the following values ​​were obtained: ν(C=O) 1768, 1697 (cm²). －１ Characteristic absorption of the imide ring was observed in the following region.

[0178] [Synthesis Example 5] Production of Polyimide Resin 5 500 g of 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Emulsifier Co., Ltd.) and 109.06 g (0.500 mol) of pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were introduced into a 2 L separable flask equipped with a Dean-Stark apparatus, Liebig condenser, thermocouple, and four paddle blades. After nitrogen flow, the mixture was stirred at 150 rpm to obtain a homogeneous suspension solution. Meanwhile, in a 500 mL beaker, 26.12 g (0.184 mol) of 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 45.10 g (0.313 mol) of 1,8-octamethylenediamine (manufactured by Kanto Chemical Co., Ltd.) were dissolved in 200 g of 2-(2-methoxyethoxy)ethanol to prepare a mixed diamine solution. This mixed diamine solution was gradually added using a plunger pump. During the dropwise addition of the mixed diamine solution, a nitrogen flow was maintained throughout, and the impeller speed was set to 250 rpm. After the dropwise addition was complete, 100 g of 2-(2-methoxyethoxy)ethanol and 0.966 g (0.00744 mol) of n-octylamine (manufactured by Kanto Chemical Co., Ltd.), which is a terminal encapsulant, were added and the mixture was further stirred. At this stage, a pale yellow polyamic acid solution was obtained. Next, the stirring speed was set to 200 rpm, and the polyamic acid solution in the 2 L separable flask was heated to 190°C. During the heating process, precipitation of polyimide resin powder and dehydration due to imidization were observed between 120 and 140°C. After holding at 190°C for 30 minutes, the mixture was allowed to cool to room temperature and filtered. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180°C for 10 hours to obtain 158 g of polyimide resin 5 powder.

[0179] The above measurements and evaluations were performed using the obtained polyimide resin 5. The results are shown in Table 1. When the IR spectrum of the polyimide resin 5 was measured, the following values ​​were obtained: ν(C=O) 1768, 1697 (cm²). －１ Characteristic absorption of the imide ring was observed in the following region.

[0180] [Synthesis Example 6] Production of Polyimide Resin 6 500 g of 2-(2-methoxyethoxy)ethanol (manufactured by Nippon Emulsifier Co., Ltd.) and 109.06 g (0.500 mol) of pyromellitic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.) were introduced into a 2 L separable flask equipped with a Dean-Stark apparatus, Liebig condenser, thermocouple, and four paddle blades. After nitrogen flow, the mixture was stirred at 150 rpm to obtain a homogeneous suspension solution. Meanwhile, in a 500 mL beaker, 24.71 g (0.174 mol) of 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and 55.59 g (0.323 mol) of 1,10-decamethylenediamine (manufactured by Kanto Chemical Co., Ltd.) were dissolved in 200 g of 2-(2-methoxyethoxy)ethanol to prepare a mixed diamine solution. This mixed diamine solution was gradually added using a plunger pump. During the dropwise addition of the mixed diamine solution, a nitrogen flow was maintained throughout, and the impeller speed was set to 250 rpm. After the dropwise addition was complete, 100 g of 2-(2-methoxyethoxy)ethanol and 0.966 g (0.00744 mol) of n-octylamine (manufactured by Kanto Chemical Co., Ltd.), which is a terminal encapsulant, were added and the mixture was further stirred. At this stage, a pale yellow polyamic acid solution was obtained. Next, the stirring speed was set to 200 rpm, and the polyamic acid solution in the 2 L separable flask was heated to 190°C. During the heating process, precipitation of polyimide resin powder and dehydration due to imidization were observed between 120 and 140°C. After holding at 190°C for 30 minutes, the mixture was allowed to cool to room temperature and filtered. The obtained polyimide resin powder was washed with 300 g of 2-(2-methoxyethoxy)ethanol and 300 g of methanol, filtered, and then dried in a dryer at 180°C for 10 hours to obtain 166 g of polyimide resin 6 powder.

[0181] The above measurements and evaluations were performed using the obtained polyimide resin 6. The results are shown in Table 1. When the IR spectrum of the polyimide resin 6 was measured, the following values ​​were obtained: ν(C=O) 1768, 1697 (cm²). －１ Characteristic absorption of the imide ring was observed in the following region.

[0182]

[0183] <Method for manufacturing continuous thermoplastic polyimide resin fibers> The thermoplastic resin shown in Table 2 was melt-extruded using a single-screw extruder with a diameter screw of 30 mm, extruded in strand form from a 48-hole die, stretched while being wound on a roll, and a 500 m bundle of continuous thermoplastic resin fibers was wound onto a winding body. The melting temperature was set to the melting point of the continuous thermoplastic resin + 20°C.

[0184] <Types of reinforcing fibers used> Carbon fiber 1: Toray Industries, T700SC-12k-60E Carbon fiber 2: Toray Industries, T700SC-24k-60E Carbon fiber 3: Toray Industries, T700SC-6k-60E Carbon fiber 4: SGL Carbon Industries, T50-4 / 240-E100

[0185] Examples 1-14, Comparative Examples 1-5 <Production of Blended Yarn> Blended yarn was produced by combining the continuous thermoplastic polyimide resin fibers and continuous carbon fibers obtained above as shown in Tables 2-5.

[0186] Specifically, continuous thermoplastic polyimide resin fibers, also aligned to a length of 100,000 m or more, were layered on top of and below continuous carbon fibers, each aligned to a length of 10,000 m or more, to form a bundle. The degree of dispersion of the continuous carbon fibers in the bundle was 90% or more.

[0187] Next, the bundles were interlaced at the frequencies shown in Tables 2 to 5 to entangle the continuous carbon fibers.

[0188] The resulting blended yarn was wound onto a paper tube to form a winding.

[0189] <Release Ease> We evaluated whether the blended yarn could be removed from the winding body obtained above without snagging or stopping midway. The release ease was evaluated as follows.

[0190] A: The core can be removed without snagging until the very end. B: The fiber bundle snagged midway when being removed, but it could still be removed. For example, when removing a blended yarn, there was snagging, but it could be removed by untangling it by hand. C: The fiber bundle snagged midway when being removed and could not be removed.

[0191] <Tailored Fiber Placement (TFP) Processing Performance> A TFP processing device manufactured by TISM Corporation was used, and stitching was performed with the blended yarn obtained above.

[0192] The stitching performance was evaluated as follows. Comparative Example 2 was assigned a rating of "B," and the evaluation was determined by a majority vote of five experts.

[0193] A: Even with complex shapes, stitching was achieved with the blended yarn positioned as desired. B: Even with complex shapes, stitching was achieved with the blended yarn positioned slightly off-center from the desired position. C: Other than A and B, the stitching resulted in the blended yarn being positioned clearly off-center from the desired position.

[0194] <Moldability> The obtained blended yarn was stitched by TFP processing to form a 20 cm square plate. Specifically, the blended yarn was stitched in one direction for 20 cm from the left end to the right end, folded back at the end, and then stitched in one direction for 20 cm from the right end to the left end. This was repeated until a 20 cm width was obtained using a single blended yarn, resulting in a 20 cm square plate. Four of these plates were prepared and stacked, then press-molded using thermoplastic polyimide resin at a melting point of +20°C, a pressure of 3 MPa, and a holding time of 15 minutes. Visual observation revealed that plate-shaped molded products were obtained in Examples 1-14 and Comparative Examples 1-4. The cross-section of the obtained molded product was 2 mm. ２ The area was observed using a digital microscope (Keyence Corporation "VHX-6000") at a magnification of 500x, and the presence or absence of voids was evaluated according to the following criteria. The cross-section of the molded product was taken from approximately the center of the product. The cross-section (selection of measurement area) and observation of the molded product were performed by five experts, and the following judgment was made based on the average of their respective evaluation results.

[0195] A: In the cross-section of the test specimen, there are 0 or more voids and less than 2 B: In the cross-section of the test specimen, there are 2 or more voids and less than 5 C: In the cross-section of the test specimen, there are 5 or more voids <Tensile Strength> From the molded product press-formed in the above moldability section, a piece with a width of 15 mm, a thickness of 2 mm, and a length of 250 mm was cut to obtain a test specimen.

[0196] The obtained test specimens were measured for tensile strength in accordance with ASTM D3039.

[0197] The detailed conditions are as follows:

[0198] Testing machine: Electro-hydraulic servo-type material testing machine with load capacity of 100 kN (8501: Instron Co., Ltd.) Testing speed: 1 mm / min Chuck distance: 150 mm Testing environment: 23°C, 50% RH The following evaluation was performed.

[0199] A: 2200 MPa or higher B: 1800 MPa or higher but less than 2200 MPa C: Less than 1800 MPa

[0200] <Overall Evaluation> Based on the above results, the overall evaluation was made as follows: A: All evaluation items are A B: Removability is A, and at least one of the other evaluation items is B C: Removability is B, and the other evaluation items are A or B D: At least one of the evaluation items is C

[0201]

[0202]

[0203]

[0204]

[0205] As is clear from the results above, the blended yarn of this embodiment achieved high tensile strength while possessing flexibility at a level that makes TFP possible (Examples 1 to 14). In all cases, in the portions that were not interlaced, the continuous thermoplastic polyimide resin fibers and continuous carbon fibers were not entangled, and the linearity of the continuous carbon fibers was maintained. Furthermore, the dispersion degree in the portions that were not interlaced was 90% or more.

[0206] In contrast, when the fineness of the continuous thermoplastic polyimide resin fibers was relatively fine compared to the continuous reinforced fibers (Comparative Example 1), the release properties were inferior, as was the TFP performance. Conversely, when the fineness of the continuous thermoplastic polyimide resin fibers was relatively thicker compared to the continuous reinforced fibers (Comparative Examples 2 and 3), the moldability and tensile strength were inferior.

[0207] When the number of interlacing steps was increased (Comparative Example 4), the tensile strength was inferior.

[0208] When interlacing was not performed (Comparative Example 5), release properties could not be achieved.

[0209] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible without departing from the intent and scope of the invention.

[0210] 1. Continuous reinforcing fibers 2. Continuous thermoplastic polyimide resin fibers

Claims

1. A blended yarn comprising continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers, wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fibers to the fineness of the continuous reinforcing fibers (fineness of continuous thermoplastic polyimide resin fibers / fineness of continuous reinforcing fibers) is 0.009 to 0.090, and the blended yarn is intertwined with at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers at a rate of 1 to 500 locations per 500 m, and the remaining portion consists of continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers arranged in parallel with linearity in the fiber length direction.

2. The blended yarn according to claim 1, wherein at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers are interlaced to form an entanglement.

3. The continuous thermoplastic polyimide resin fiber comprises repeating structural units represented by the following formula (1) and repeating structural units represented by the following formula (2): (R １ R is a divalent group having 6 to 22 carbon atoms and containing at least one alicyclic hydrocarbon structure. ２ X is a divalent, chain-like aliphatic group having 5 to 16 carbon atoms. １ and X ２ Each of these is independently a tetravalent group having 6 to 22 carbon atoms and containing at least one aromatic ring.) The blended yarn according to claim 1 or 2 is a polyimide resin that contains the repeating structural units of formula (1) to the total of the repeating structural units of formula (2) and the repeating structural units of formula (1) is 20 mol% or more and less than 40 mol%, and satisfies the following conditions (a), (b), and (c). Condition (a): Melting point (Tm) is 280°C or higher and 345°C or lower Condition (b): Glass transition temperature (Tg) is 140°C or higher and 200°C or lower Condition (c): The amount of heat of the crystallization exothermic peak observed when cooled at a cooling rate of 20°C / min after melting, as measured by differential scanning calorimeter, is 17.0 mJ / mg or more 4. The above R １ is a divalent group represented by the following formula (R1-1) or (R1-2), and the conjugated fiber according to claim 3. (m １１ and m １２ are each independently an integer of 0 to 2. m １３ to m １５ are each independently an integer of 0 to 2. ) 5. The aforementioned R １ The blended yarn according to claim 3 or 4, wherein is a divalent group represented by the following formula (R1-3).

6. The aforementioned R ２ The blended yarn according to any one of claims 3 to 5, wherein is an alkylene group having 7 to 12 carbon atoms.

7. X １ and X ２ However, each is independently a tetravalent base represented by any one of the following formulas (X-1) to (X-4), as described in any one of claims 3 to 6, the blended yarn according to any one of claims 3 to 6. (R １１ ~R １８ These are each independently alkyl groups having 1 to 4 carbon atoms. １１ ~p １３ Each of these is an integer between 0 and 2, independently of the others. １４ , p １５ , p １６ and p １８ Each of these is an integer between 0 and 3, independently of the others. １７ L is an integer between 0 and 4. １１ ~L １３ These are, independently, a single bond, an ether group, a carbonyl group, or an alkylene group having 1 to 4 carbon atoms.

8. The blended yarn according to any one of claims 1 to 7, wherein the continuous reinforcing fiber comprises at least one selected from the group consisting of carbon fiber, glass fiber, and aramid fiber.

9. The blended yarn according to any one of claims 1 to 8, wherein the number average fiber length of the continuous reinforcing fibers is greater than 10 mm.

10. The blended yarn according to any one of claims 1 to 9, wherein the fineness of the continuous thermoplastic polyimide resin fiber is 100 to 500 denier.

11. A blended yarn according to any one of claims 1 to 10, for use in tailored fiber placement or braiding.

12. The blended yarn according to any one of claims 1 to 11, wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fiber to the fineness of the continuous reinforcing fiber (fineness of the continuous thermoplastic polyimide resin fiber / fineness of the continuous reinforcing fiber) is 0.010 to 0.

060.

13. The blended yarn according to any one of claims 1 to 12, wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fiber to the fineness of the continuous reinforcing fiber (fineness of the continuous thermoplastic polyimide resin fiber / fineness of the continuous reinforcing fiber) is 0.010 to 0.060, and the fineness of the continuous thermoplastic polyimide resin fiber is 100 to 500 denier.

14. The blended yarn according to any one of claims 1 to 13, wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fibers to the fineness of the continuous reinforcing fibers (fineness of continuous thermoplastic polyimide resin fibers / fineness of continuous reinforcing fibers) is 0.015 to 0.050, the blended yarn is intertwined with at least a portion of the continuous thermoplastic polyimide resin fibers and at least a portion of the continuous reinforcing fibers at a rate of 1 to 90 places per 500 m, and the fineness of the continuous thermoplastic polyimide resin fibers is 110 to 350 denier.

15. A method for manufacturing a molded article, comprising tailoring fiber placement or braiding a blended yarn according to any one of claims 1 to 14.

16. A method for producing a blended yarn, comprising interlacing a fiber bundle containing continuous thermoplastic polyimide resin fibers and continuous reinforcing fibers, wherein the ratio of the fineness of the continuous thermoplastic polyimide resin fibers to the fineness of the continuous reinforcing fibers (fineness of continuous thermoplastic polyimide resin fibers / fineness of continuous reinforcing fibers) is 0.009 to 0.090, at a rate of 1 to 500 locations per 500 m of the fiber bundle.

17. The method for producing a blended yarn according to claim 16, wherein the blended yarn is the blended yarn described in any one of claims 1 to 14.

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