Combined filament yarn, woven fabric, and method for producing shaped article

Abstract

The purpose of the present invention is to provide a combined filament yarn excellent in flexibility, woven fabric, and a method for producing a shaped article. This combined filament yarn of the present invention comprises continuous thermoplastic resin fibers and continuous reinforcing fibers, wherein the continuous thermoplastic resin fibers contain a diamine unit and a dicarboxylic acid unit, 70 mol% or more of the diamine unit is derived from xylylenediamine, and 70 mol% or more of the dicarboxylic acid unit contains a polyamide resin derived from an α,ω-linear aliphatic dicarboxylic acid having 11-20 carbon atoms.

Description

Method for manufacturing blended yarn, woven fabric and molded product

[0001] The present invention relates to a method for producing a mixed yarn, a woven fabric, and a molded article, and more particularly to a mixed yarn using a specific polyamide resin.

[0002] Conventionally, mixed yarns using thermoplastic resin fibers and continuous reinforcing fibers have been studied. Taking advantage of their supple properties, mixed yarns are suitable for use in molded articles with complex shapes or molded articles that require particular strength. As an application example of mixed yarns, mixed yarns whose fiber components are continuous thermoplastic resin fibers and continuous reinforcing fibers are known. Furthermore, stitching (embroidery) using such mixed yarns has also been studied (Patent Documents 1 and 2). This type of stitching is called tailored fiber placement (TFP).

[0003] International Publication No. 2016 / 159340 Japanese Patent Application Laid-Open No. 2020-063342

[0004] Here, Patent Document 1 discusses TFP processing using a mixed yarn containing continuous thermoplastic resin fibers made from a polyamide resin composed of sebacic acid and xylylenediamine and continuous carbon fibers. While the mixed yarn is an excellent material, there has been a demand in recent years for mixed yarns that can be processed more precisely through TFP. That is, for parts that require aesthetic appeal, there is a demand for mixed yarns that are flexible enough to accommodate more complex shapes. The present invention aims to solve this problem by providing a method for producing a mixed yarn, woven fabric, and molded article that are highly flexible.

[0005] In light of the above-mentioned problems, the present inventors have conducted research and found that the above-mentioned problems can be solved by using a specific polyamide resin. <1> A mixed yarn comprising continuous thermoplastic resin fibers and continuous reinforcing fibers, wherein the continuous thermoplastic resin fibers contain diamine units and dicarboxylic acid units, and the continuous thermoplastic resin fibers contain a polyamide resin in which 70 mol % or more of the diamine units are derived from xylylenediamine, and 70 mol % or more of the dicarboxylic acid units are derived from an α,ω-linear aliphatic dicarboxylic acid having 11 to 20 carbon atoms. <2> The mixed yarn according to <1>, in which 70 mol % or more of the dicarboxylic acid units are derived from dodecanedioic acid and / or tetradecanedioic acid. <3> The mixed yarn according to <1>, in which 70 mol % or more of the dicarboxylic acid units are derived from dodecanedioic acid. <4> The mixed yarn according to any one of <1> to <3>, in which 20 to 100 mol% of the diamine units are derived from meta-xylylenediamine and 80 to 0 mol% are derived from para-xylylenediamine (provided that the total does not exceed 100 mol%). <5> The mixed yarn according to <1>, in which 70 mol% or more of the dicarboxylic acid units are derived from dodecanedioic acid and / or tetradecanedioic acid, and 20 to 100 mol% of the diamine units are derived from meta-xylylenediamine and 80 to 0 mol% are derived from para-xylylenediamine (provided that the total does not exceed 100 mol%). <6> The mixed yarn according to any one of <1> to <5>, in which the continuous reinforcing fibers contain at least one fiber selected from the group consisting of carbon fiber, glass fiber, and aramid fiber. <7> The mixed yarn according to any one of <1> to <6>, in which the number average fiber length of the continuous reinforcing fibers is more than 10 mm. <8> The mixed yarn according to any one of <1> to <7>, wherein the continuous thermoplastic resin fiber is an undrawn fiber. <9> The mixed yarn according to any one of <1> to <8>, which is for tailored fiber placement processing. <10> A woven fabric formed from the mixed yarn according to any one of <1> to <9>. <11> A method for producing a molded article, comprising heat processing the mixed yarn according to any one of <1> to <9>. <12> A method for producing a molded article, comprising subjecting the mixed yarn according to any one of <1> to <9> to tailored fiber placement processing.

[0006] The present invention makes it possible to provide a method for producing a blended yarn, a woven fabric, and a molded article having excellent flexibility.

[0007] Fig. 1 is a schematic diagram showing the state in which the mixed yarn of the present invention is stitched with a shape-retaining yarn. Fig. 2 is an image diagram showing the embroidery results when stitching the mixed yarn of the prior art (A) and the mixed yarn of the present invention (B). Fig. 3 is an image diagram showing the method for measuring the shapeability of the present example.

[0008] A detailed description of an embodiment of the present invention (hereinafter simply referred to as "the present embodiment") is provided below. Note that the following present embodiment is an example for explaining the present invention, and the present invention is not limited to this embodiment. In this specification, the use of "to" means that the numerical values ​​before and after the "to" symbol include the upper and lower limits. Furthermore, any combination of the upper and lower limits of a numerical value in this specification is an example of this embodiment. In this specification, various physical property values ​​and characteristic values ​​are assumed to be at 23°C unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification vary from year to year, they shall be based on the standards in effect as of January 1, 2024, unless otherwise specified. If the measurement methods, etc. described in the standards shown in this specification are discontinued as of January 1, 2024, they shall be based on the standards in effect at the time of discontinuation. The scales, etc., of Figures 1 to 3 may not be accurate.

[0009] The mixed yarn of this embodiment is characterized in that it contains continuous thermoplastic resin fibers and continuous reinforcing fibers, and the continuous thermoplastic resin fibers contain a polyamide resin containing diamine units and dicarboxylic acid units, in which 70 mol % or more of the diamine units are derived from xylylenediamine and 70 mol % or more of the dicarboxylic acid units are derived from an α,ω-linear aliphatic dicarboxylic acid having 11 to 20 carbon atoms. By using such a configuration, it is possible to provide a mixed yarn with excellent flexibility.

[0010] FIG. 1 is a schematic diagram showing the state in which a mixed yarn 1 of this embodiment has been stitched with a shape-retaining yarn 2. As shown in FIG. 1, by using the mixed yarn 1 of this embodiment, desired embroidery (stitching) can be achieved with TFP. The stitching needles are mechanically controlled, and the shape-retaining yarn 2 stitches the mixed yarn 1, thereby maintaining the mixed yarn 1 in the desired shape. If the mixed yarn is too stiff, it will twist within the shape-retaining yarn. In this embodiment, it has been discovered that by using a specific polyamide resin, the mixed yarn can be stitched in the desired position even when stitching a complex shape. FIG. 2 is an image diagram showing the embroidery results when a mixed yarn containing continuous thermoplastic resin fiber and continuous carbon fiber using a polyamide resin composed of sebacic acid and xylylenediamine (FIG. 2(A)) and the mixed yarn of this embodiment (FIG. 2(B)) are stitched together. The shape-retaining yarn is not shown in FIG. 2. In Figure 2(A), a mixed yarn 1 containing continuous thermoplastic resin fiber using a polyamide resin composed of sebacic acid and xylylenediamine and continuous carbon fiber is used for stitching. In Figure 2(A), the mixed yarn 1 is stitched deviating from the designed desired pattern 3 (the dotted line portion in Figure 2(A)). This is because the mixed yarn 1 shown in Figure 2(A) is an excellent mixed yarn with excellent rigidity, but because of its excellent rigidity, the mixed yarn is stiff and twists within the shape-retaining yarn, resulting in the mixed yarn 1 retaining its shape slightly deviating from the set desired pattern 3. In contrast, as shown in Figure 2(B), when the mixed yarn of this embodiment is used, the mixed yarn is flexible and is arranged to follow the designed desired pattern, and the desired pattern is formed by the mixed yarn 1 through stitching. Note that Figure 2 is an image diagram to clarify the differences between the prior art and this embodiment, and does not necessarily represent the actual stitched state. In practice, the effect of using the mixed yarn of this embodiment becomes clear when stitching an elliptical pattern with an even smaller radius of curvature (for example, an elliptical pattern of 3 cm width and 10 cm length). The details of this embodiment will be described below.

[0011] <Mixed Yarn> The mixed yarn of this embodiment preferably has continuous reinforcing fibers dispersed therein, and the continuous reinforcing fibers and continuous thermoplastic resin fibers are bundled (preferably in the form of a tape). When forming the fibers into bundles, a sizing agent or a surface treatment agent is preferably used. Furthermore, in the mixed yarn of this embodiment, it is preferable that the continuous thermoplastic resin fibers do not impregnate the continuous reinforcing fibers, but maintain their fibrous state. Furthermore, in the mixed yarn of this embodiment, a portion of the continuous thermoplastic resin fiber component may impregnate the continuous reinforcing fibers. Specifically, in the mixed yarn of this embodiment, the impregnation rate of the continuous thermoplastic resin fiber component is preferably less than 1% and 0.5% or less. The lower limit of the impregnation rate is not particularly specified, and may be 0%.

[0012] <<Method for Measuring Impregnation Rate>> For a mixed yarn, cross sections perpendicular to the longitudinal direction of the continuous reinforcing fibers are cut out together, embedded in epoxy resin, and the surfaces corresponding to the cross sections of the mixed yarn are polished. The cross sections are then photographed using an ultra-deep color 3D shape measuring microscope. The cross sections of the mixed yarn embedded in epoxy resin are observed using a digital microscope. From the obtained cross-sectional photograph, areas where the thermoplastic resin fibers have impregnated the continuous reinforcing fibers (areas where the thermoplastic resin fibers have melted and impregnated between the continuous reinforcing fibers) are selected using image analysis software ImageJ, and their areas are measured. The impregnation rate is expressed as the area where the thermoplastic resin fibers have impregnated the continuous reinforcing fibers / cross-sectional area (unit: %). The ultra-deep color 3D shape measuring microscope used was a VK-9500 (controller unit) / VK-9510 (measurement unit) (manufactured by Keyence Corporation).

[0013] The mixed yarn is preferably treated with a treatment agent such as a sizing agent or a surface treatment agent. This configuration increases the dispersion of the continuous reinforcing fibers in the mixed yarn and makes it easier to bundle them. Examples of treatment agents include ester compounds, alkylene glycol compounds, polyolefin compounds, and phenyl ether compounds. Compounds that function as surfactants are particularly preferred.

[0014] Furthermore, the proportion of continuous reinforcing fibers in the mixed yarn is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, particularly preferably 50% by mass or more, and can be 55% by mass or more. The upper limit of the proportion of continuous reinforcing fibers in the mixed yarn is preferably 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, and can be 65% by mass or less. The mixed yarn of this embodiment may contain only one type of continuous reinforcing fiber, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0015] The proportion of continuous thermoplastic resin fibers in the mixed yarn is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and can be 35% by mass or more. The upper limit of the proportion of continuous thermoplastic resin fibers is preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, still more preferably 70% by mass or less, even more preferably 60% by mass or less, particularly preferably 50% by mass or less, and can be 45% by mass or less. The mixed yarn of this embodiment may contain only one type of continuous thermoplastic resin fiber, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0016] In addition, in the mixed yarn of this embodiment, the total of the continuous thermoplastic resin fiber and the continuous reinforcing fiber preferably accounts for 90% by mass or more of the mixed yarn, more preferably 95% by mass or more, and may even account for 99% by mass or more, or is 100% by mass or less.

[0017] The dispersion of the continuous reinforcing fibers in the mixed yarn is preferably 60 to 100%, more preferably 63 to 100%, even more preferably 68 to 100%, and particularly preferably 70 to 100%. By adjusting the dispersion to within these ranges, the mixed yarn exhibits more uniform physical properties, and the appearance of molded articles is further improved. Furthermore, when molded articles are produced using this yarn, the resulting articles have better mechanical properties.

[0018] <<Method for measuring dispersity>> The mixed fiber yarn is embedded in epoxy resin, and a cross section perpendicular to the longitudinal direction of the mixed fiber yarn is polished. The cross section is then photographed using an ultra-deep color 3D shape measuring microscope. Six auxiliary lines are drawn radially at equal intervals on the photographed image, and the length of the continuous reinforcing fiber region on each auxiliary line is measured as a1, a2, a3... ai (i = n). In addition, the length of the continuous thermoplastic resin fiber region on each auxiliary line is measured as b1, b2, b3... bi (i = m). Based on the results, the dispersity is calculated using the following formula. The ultra-deep color 3D shape measuring microscope can be the VK-9500 (controller unit) / VK-9510 (measuring unit) (manufactured by Keyence).

[0019] The mixed yarn is usually produced using a continuous thermoplastic resin fiber bundle and a continuous reinforcing fiber bundle. The continuous reinforcing fibers and / or continuous thermoplastic resin fibers used in the mixed yarn are preferably surface-treated with a treatment agent. This configuration makes it easier to obtain a mixed yarn in which the continuous reinforcing fibers and continuous thermoplastic resin fibers are more uniformly dispersed, and also improves the impregnation rate of the continuous thermoplastic resin fiber component into the continuous reinforcing fibers after molding. For other details of the mixed yarn, please refer to paragraphs 0018 to 0039 of WO 2016 / 159340, the contents of which are incorporated herein by reference.

[0020] <Continuous thermoplastic resin fiber> The mixed yarn of this embodiment contains continuous thermoplastic resin fiber. Continuous thermoplastic resin fiber refers to a thermoplastic resin fiber having an average fiber length of more than 6 mm, preferably a thermoplastic resin fiber having an average fiber length of more than 10 mm, more preferably a thermoplastic resin fiber having an average fiber length of more than 12 mm, more preferably a thermoplastic resin fiber having an average fiber length of more than 30 mm, and even more preferably a thermoplastic resin fiber having an average fiber length of more than 10 cm. There are no particular restrictions on the average fiber length of the continuous thermoplastic resin fiber 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 preferably 20,000 m or less, more preferably 1,0000 m or less, and even more preferably 7,000 m or less.

[0021] The polyamide resin constituting the continuous thermoplastic resin fibers contains diamine units and dicarboxylic acid units, and includes a polyamide resin (hereinafter sometimes referred to as a "xylylenediamine-based polyamide resin") in which 70 mol % or more of the diamine units are derived from xylylenediamine and 70 mol % or more of the dicarboxylic acid units are derived from an α,ω-linear aliphatic dicarboxylic acid having 11 to 20 carbon atoms.

[0022] The diamine units of the xylylenediamine-based polyamide resin are preferably derived from xylylenediamine (preferably paraxylylenediamine and / or metaxylylenediamine) at 75 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 99 mol% or more.

[0023] The xylylenediamine is preferably paraxylylenediamine and / or metaxylylenediamine. The xylylenediamine preferably contains 0 to 100 mol% metaxylylenediamine and 100 to 0 mol% paraxylylenediamine (provided that the total of metaxylylenediamine and paraxylylenediamine does not exceed 100 mol%), and more preferably contains 20 to 100 mol% metaxylylenediamine and 80 to 0 mol% paraxylylenediamine. In the xylylenediamine-based polyamide resin, the total of paraxylylenediamine units and metaxylylenediamine units preferably accounts for 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, even more preferably 98 mol% or more, and even more preferably 99 mol% or more of the diamine units. The upper limit of the total of the paraxylylenediamine units and metaxylylenediamine units is 100 mol%.

[0024] Diamines other than metaxylylenediamine and paraxylylenediamine that can be used as raw diamine components for xylylenediamine-based polyamide resins include aliphatic diamines such as tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl-hexamethylenediamine, and 2,4,4-trimethylhexamethylenediamine; 1,3-bis( Examples of the diamine include alicyclic diamines such as bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,2-bis(4-aminocyclohexyl)propane, bis(aminomethyl)decalin, and bis(aminomethyl)tricyclodecane; and diamines having an aromatic ring such as bis(4-aminophenyl)ether, paraphenylenediamine, and bis(aminomethyl)naphthalene, and these can be used alone or in combination of two or more.

[0025] On the other hand, the dicarboxylic acid units of the xylylenediamine-based polyamide resin are preferably derived from 75 mol% or more, more preferably 80 mol% or more, even more preferably 85 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more, and particularly preferably 99 mol% or more of straight-chain aliphatic α,ω-dicarboxylic acids preferably having 11 to 20 carbon atoms.

[0026] The α,ω-linear aliphatic dicarboxylic acid having 11 to 20 carbon atoms that is preferably used as the raw dicarboxylic acid component of the xylylenediamine-based polyamide resin is preferably an α,ω-linear aliphatic dicarboxylic acid having 11 to 16 carbon atoms, and more preferably an α,ω-linear aliphatic dicarboxylic acid having 12 to 14 carbon atoms. Specific examples of the α,ω-linear aliphatic dicarboxylic acid having 11 to 20 carbon atoms include dodecanedioic acid, tridecanedioic acid, and tetradecanedioic acid. Among these, dodecanedioic acid and / or tetradecanedioic acid are preferred, with dodecanedioic acid being more preferred, as the melting point of the polyamide resin is in a range suitable for molding.

[0027] Examples of dicarboxylic acid components other than those mentioned above include α,ω-linear aliphatic dicarboxylic acids having 10 or less carbon atoms, such as adipic acid and sebacic acid; phthalic acid compounds, such as isophthalic acid, terephthalic acid and orthophthalic acid; and isomers of naphthalenedicarboxylic acid, such as 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid. These can be used alone or in combination of two or more.

[0028] Although the xylylenediamine-based polyamide resin is primarily composed of diamine units and dicarboxylic acid units, other structural units are not completely excluded. It goes without saying that the resin may contain structural units derived from lactams such as ε-caprolactam and laurolactam, and aliphatic aminocarboxylic acids such as aminocaproic acid and aminoundecanoic acid. Here, "major component" refers to the structural units constituting the xylylenediamine-based polyamide resin in which the total number of diamine units and dicarboxylic acid units is the largest among all structural units. In this embodiment, the total of the diamine units and dicarboxylic acid units in the xylylenediamine-based polyamide resin preferably accounts for 90% by mass or more of all structural units, more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0029] It is also preferable to use a polyamide resin produced using biomass raw materials (biomass polyamide resin) as the xylylenediamine-based polyamide resin. Using biomass polyamide resin can reduce the environmental impact. Mass balance certified (ISCC PLUS) raw material monomers can also be used. Mass balance certification means that the amount of renewable raw materials and bio-based raw materials used at each factory or production facility and the amount of products produced and shipped are quantified, and the quality is guaranteed.

[0030] The melting point of the xylylenediamine-based polyamide resin is preferably 150°C or higher, more preferably 160°C or higher, even more preferably 170°C or higher, and even more preferably 180°C or higher, and is preferably 300°C or lower, more preferably 290°C or lower, even more preferably 280°C or lower, and even more preferably 275°C or lower. The melting point is measured according to the description in the examples below. When the mixed yarn of this embodiment contains two or more types of xylylenediamine-based polyamide resins, the melting point is the weighted average of the respective polyamide resins.

[0031] The lower limit of the number average molecular weight (Mn) of the xylylenediamine-based polyamide resin is preferably 6,000 or more, more preferably 8,000 or more, even more preferably 10,000 or more, and preferably 100,000 or less, more preferably 50,000 or less. Within such ranges, the heat resistance, elastic modulus, dimensional stability, and moldability are improved. The number average molecular weight is a polystyrene-equivalent value measured by GPC (gel permeation chromatography). More specifically, the number average molecular weight can be measured according to the description in paragraph 0047 of JP 2018-165298 A, the contents of which are incorporated herein by reference. The xylylenediamine-based polyamide resin used in this embodiment preferably has a content of compounds having a molecular weight of 310 or more and 1,000 or less of less than 0.1% by mass or more than 1.5% by mass. The xylylenediamine-based polyamide resin used in this embodiment preferably contains more than 0.1% by mass of compounds having a molecular weight of less than 310.

[0032] The continuous thermoplastic resin fibers may contain a polyamide resin other than a xylylenediamine-based polyamide resin. Examples of polyamide resins other than a xylylenediamine-based polyamide resin include aliphatic polyamide resins and semi-aromatic polyamide resins other than a xylylenediamine-based polyamide resin. Examples of aliphatic polyamide resins include polyamide 4, polyamide 46, polyamide 6, polyamide 66, polyamide 666, polyamide 610, polyamide 11, and polyamide 12. Examples of semi-aromatic polyamide resins include terephthalic acid-based polyamide resins (polyamide 6T, polyamide 9T, and polyamide 10T). When the continuous thermoplastic resin fibers contain a polyamide resin other than a xylylenediamine-based polyamide resin, the content of the polyamide resin other than a xylylenediamine-based polyamide resin is preferably less than 10% by mass, more preferably less than 5% by mass, even more preferably less than 3% by mass, and even more preferably less than 1% by mass, of the content of the xylylenediamine-based polyamide resin.

[0033] The continuous thermoplastic resin fiber may be surface-treated with a surface treatment agent. The continuous thermoplastic resin fiber may be drawn or undrawn. In this embodiment, it is preferable that the continuous thermoplastic resin fiber is undrawn. By not drawing the continuous thermoplastic resin fiber, a mixed yarn having better flexibility can be obtained.

[0034] The continuous thermoplastic resin fiber may or may not contain components other than polyamide resin. Examples of the other components include thermoplastic resins other than polyamide resins, stabilizers such as antioxidants and heat stabilizers, additives such as hydrolysis resistance improvers, weathering stabilizers, delustering agents, UV absorbers, nucleating agents, plasticizers, dispersants, flame retardants, antistatic agents, coloring inhibitors, antigelling agents, colorants, and release agents. For details, see paragraphs

[0130] to

[0155] of Japanese Patent No. 4,894,982 and paragraphs

[0047] to

[0103] of International Publication No. 2021 / 241,471, the contents of which are incorporated herein by reference. The content of components other than polyamide resin contained in these continuous thermoplastic resin fibers is preferably less than 10% by mass of the mixed 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. The continuous thermoplastic resin fibers preferably do not contain cobalt stearate, and further preferably do not contain cobalt salts.

[0035] <Continuous reinforcing fiber> The mixed yarn of this embodiment contains continuous reinforcing fiber. Continuous reinforcing fiber refers to a reinforcing fiber having an average fiber length of more than 6 mm, preferably more than 10 mm, more preferably more than 12 mm, even more preferably more than 30 mm, and even more preferably more than 10 cm. The average fiber length of the continuous reinforcing fiber used in this embodiment is not particularly limited, but from the viewpoint of improving molding processability, it is preferably 1 m or more, more preferably 100 m or more, even more preferably 1,000 m or more, and preferably 20,000 m or less, more preferably 1,0000 m or less, and even more preferably 7,000 m or less.

[0036] Examples of continuous reinforcing fibers include inorganic fibers such as glass fibers, carbon fibers, metal fibers, boron fibers, basalt fibers, and ceramic fibers; and organic fibers such as aramid fibers, polyoxymethylene fibers, aromatic polyamide fibers, polyparaphenylene benzobisoxazole fibers, and ultra-high molecular weight polyethylene fibers. Among these, it is preferable to include at least one fiber selected from the group consisting of carbon fibers, glass fibers, and aramid fibers, with carbon fibers and / or glass fibers being more preferred, and carbon fibers being even more preferred. Examples of carbon fibers include polyacrylonitrile-based carbon fibers and pitch-based carbon fibers. Examples of glass fibers include fibers obtained by melt spinning commonly supplied glasses such as E-glass, C-glass, A-glass, S-glass, and alkali-resistant glass.

[0037] The continuous reinforcing fibers may be surface-treated with a surface treatment agent. The cross section of the continuous reinforcing fibers may be either circular or non-circular. Regarding the continuous carbon fibers, in addition to the above, the description in paragraph 0074 of Japanese Patent No. 7398028 can be referred to, and the contents thereof are incorporated herein. The continuous reinforcing fibers in this embodiment are usually oriented in one direction.

[0038] In the case of carbon fibers, the continuous reinforcing fibers preferably have a 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 have a tensile strength of 8000 MPa or less. In the case of 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 have a tensile strength of 5000 MPa or less.

[0039] <Other Components> The mixed yarn of this embodiment may or may not contain other components in addition to the continuous thermoplastic resin fibers and continuous reinforcing fibers. Examples of such other components include thermoplastic resins other than polyamide resins, fillers other than continuous reinforcing fibers, nucleating agents, antioxidants, stabilizers such as heat stabilizers, hydrolysis resistance improvers, weathering stabilizers, delustering agents, UV absorbers, nucleating agents, plasticizers, dispersants, flame retardants, antistatic agents, coloring inhibitors, antigelling agents, colorants, and release agents. For details, see paragraphs

[0130] to

[0155] of Japanese Patent No. 4,894,982 and paragraphs

[0047] to

[0103] of International Publication No. 2021 / 241,471, the contents of which are incorporated herein by reference. The content of these other components is preferably less than 10% by mass of the mixed 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.

[0040] The mixed yarn of this embodiment is typically produced using continuous thermoplastic resin fiber bundles and continuous reinforcing fiber bundles. The continuous reinforcing fibers and / or continuous thermoplastic resin fibers used in the mixed yarn are preferably surface-treated with a treatment agent. This configuration facilitates the production of a mixed yarn in which the continuous reinforcing fibers and continuous thermoplastic resin fibers are more uniformly dispersed, and also improves the rate of impregnation of the continuous thermoplastic resin fiber component into the continuous reinforcing fibers after molding. For other details of the mixed yarn and its production method, please refer to paragraphs

[0018] to

[0039] of WO 2016 / 159340 and paragraph

[0051] of JP 2020-063342 A, the contents of which are incorporated herein by reference. Each mixed yarn of this embodiment typically contains 2 to 1,000 (preferably 10 to 100) continuous thermoplastic resin fibers and 2 to 1,000 (preferably 10 to 100) continuous reinforcing fibers.

[0041] The blended yarn of this embodiment can be heat-processed to produce molded articles. The molded articles are not particularly limited, and are widely used in transportation vehicle parts such as automobiles and aircraft, general machinery parts, precision machinery parts, electronic and electrical equipment parts, office automation equipment parts, building materials and housing-related parts, medical devices, leisure sports goods, play equipment, medical supplies, daily necessities such as food packaging films, defense and aerospace products, etc. In particular, it is suitable for use as a molding material for medical prostheses (e.g., lower limb orthoses), window frames for automobiles, trains, and ships, goggle frames for helmets, eyeglass frames, safety shoes, etc. The composite material of the present invention is particularly useful as a material for forming medical prostheses and secondary structural components for automobiles. It is also suitable for producing molded articles with concave or convex portions.

[0042] The mixed yarn of this embodiment is preferably used for tailored fiber placement (TFP). The mixed yarn of this embodiment is also preferably used as a yarn for applications involving reeling, such as braiding machines, knitting machines, and looms. That is, examples of applications include tailored fiber placement products using the mixed yarn of this embodiment, woven fabrics formed from the mixed yarn of this embodiment, and knitted fabrics formed from the mixed yarn of this embodiment. Examples of applications involving reeling, in this embodiment, include braided cords and twisted cords.

[0043] Returning to Fig. 1 , the case where the mixed yarn of this embodiment is subjected to tailored fiber placement processing will be described. Fig. 1 shows an example of the case where the mixed yarn of this embodiment is subjected to tailored fiber placement processing, with 1 indicating the mixed yarn of this embodiment and 2 indicating the shape-retaining yarn. In the TFP processing, preferably, the mixed yarn 1 is arranged so as to follow the shape of the molded article, and stitched with the shape-retaining yarn 2. The shape-retaining yarn 2 is usually a continuous thermoplastic resin fiber, and the preferred range etc. is the same as that of the continuous thermoplastic resin fiber described above. The mixed yarn of this embodiment can be preferably used for molded articles having, for example, two or more, preferably three or more turn-up portions as shown in Fig. 1 . In particular, it is preferably used for producing molded articles having turn-up portions with a turn-up angle of 90° or more as shown in Fig. 1 .

[0044] The molded article of this embodiment is molded by heat processing the mixed fiber yarn. The molded article of this embodiment can also be molded by heat processing a tailored fiber placement processed product of the mixed fiber yarn.

[0045] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0046] <Raw Materials> Continuous carbon fiber: TR3523, PYROFIL (registered trademark) manufactured by Mitsubishi Chemical Corporation MP12 (30): Polyamide resin synthesized according to Synthesis Example 1 below MP12 (40): Polyamide resin synthesized according to Synthesis Example 2 below MP14 (30): Polyamide resin synthesized according to Synthesis Example 3 below MXD12: Polyamide resin synthesized according to Synthesis Example 4 below PXD12: Polyamide resin synthesized according to Synthesis Example 5 below MP10 (30): Polyamide resin synthesized according to Synthesis Example 6 below PXD10: Polyamide resin synthesized according to Synthesis Example 7 below

[0047] Synthesis Example 1: Synthesis of MP12 (30) Dodecanedioic acid was placed in a jacketed reactor equipped with a stirrer, partial condenser, condenser, thermometer, dropping tank, and nitrogen gas inlet tube. The contents were thoroughly purged with nitrogen and heated to 180°C to melt. While stirring the contents, a mixed amine (70:30) of metaxylylenediamine and paraxylylenediamine (MPXDA, manufactured by Mitsubishi Gas Chemical Company, Inc.) was gradually added dropwise to a molar ratio of 1:1 to dodecanedioic acid, while the temperature was raised to 290°C. After the addition was completed, the liquid temperature was maintained at 290°C and the reaction was continued for 10 minutes. The internal pressure of the reaction system was then continuously reduced to 600 Torr over 10 minutes, and the reaction was continued for 20 minutes. During this time, the reaction temperature was continuously raised to 300°C. After the reaction was completed, the inside of the reactor was pressurized with nitrogen gas to 0.3 MPa, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization vessel, cooled with water, and then pelletized with a pelletizer.

[0048] Synthesis Example 2: Synthesis of MP12 (40) Dodecanedioic acid was placed in a jacketed reactor equipped with a stirrer, partial condenser, condenser, thermometer, dropping tank, and nitrogen gas inlet tube. The contents were thoroughly purged with nitrogen and heated to 180°C to melt. While stirring the contents, a mixed amine (60:40) of metaxylylenediamine and paraxylylenediamine (MXDA, manufactured by Mitsubishi Gas Chemical Company, Inc.; PXDA, manufactured by Showa Denko K.K.) was gradually added dropwise to a molar ratio of 1:1 to dodecanedioic acid, while the temperature was raised to 290°C. After the addition was completed, the liquid temperature was maintained at 290°C and the reaction was continued for 10 minutes. Thereafter, the internal pressure of the reaction system was continuously reduced to 600 Torr over 10 minutes, and the reaction was continued for 20 minutes. During this time, the reaction temperature was continuously raised to 300°C. After the reaction was completed, the reactor was pressurized with nitrogen gas at 0.3 MPa, and the polymer was taken out as strands from a nozzle at the bottom of the polymerization vessel, cooled with water, and then pelletized with a pelletizer.

[0049] Synthesis Example 3: Synthesis of MP14 (30) Tetradecanedioic acid was placed in a jacketed reactor equipped with a stirrer, partial condenser, condenser, thermometer, dropping tank, and nitrogen gas inlet tube. The atmosphere was thoroughly purged with nitrogen and the temperature was raised to 180°C under a small nitrogen stream to dissolve the tetradecanedioic acid and create a uniform fluid state. A mixed amine (70:30) of meta-xylylenediamine and para-xylylenediamine (MXDA, manufactured by Mitsubishi Gas Chemical Company, Inc.; PXDA, manufactured by Showa Denko K.K.) was gradually added dropwise to the reactor over 160 minutes, so that the molar ratio to tetradodecanedioic acid was 1:1. During this time, the internal pressure of the reaction system was maintained at atmospheric pressure, and the internal temperature was continuously raised to 240°C. Water distilled with the addition of para- / meta-xylylenediamine was removed from the system via the partial condenser and condenser. After the dropwise addition of para- / meta-xylylenediamine was completed, the liquid temperature was maintained at 240°C, and the reaction was continued for 10 minutes. The pressure inside the reaction system was then continuously reduced to 600 Torr over 10 minutes, and the reaction was continued for 20 minutes. During this time, the reaction temperature was continuously raised to 250° C. After the reaction was completed, the inside of the reactor was pressurized with nitrogen gas to 0.3 MPa, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization vessel. After cooling with water, the strand was cut into pellets to obtain pellets of a melt polymer.

[0050] Synthesis Example 4: Synthesis of MXD12 Dodecanedioic acid was placed in a jacketed reactor equipped with a stirrer, partial condenser, cooler, thermometer, dropping tank, and nitrogen gas inlet tube, and the reactor was thoroughly purged with nitrogen. After heating and melting at 180°C, metaxylylenediamine (MXDA, manufactured by Mitsubishi Gas Chemical Company, Inc.) was gradually added dropwise while stirring the contents so that the molar ratio to dodecanedioic acid was 1:1, and the temperature was raised to 290°C. The reaction was continued for 10 minutes while maintaining a liquid temperature of 290°C. Thereafter, the internal pressure of the reaction system was continuously reduced to 600 Torr over 10 minutes, and then the reaction was continued for 20 minutes. During this time, the reaction temperature was continuously raised to 300°C. After completion of the reaction, a pressure of 0.3 MPa was applied to the reactor with nitrogen gas, and the polymer was removed as a strand from a nozzle at the bottom of the polymerization vessel. After water cooling, the polymer was pelletized using a pelletizer.

[0051] Synthesis Example 5: Synthesis of PXD12 Dodecanedioic acid was placed in a jacketed reactor equipped with a stirrer, partial condenser, condenser, thermometer, dropping tank, and nitrogen gas inlet tube, and the inside was thoroughly purged with nitrogen. After heating to 180°C and melting, paraxylylenediamine (PXDA, manufactured by Showa Denko) was gradually added dropwise while stirring the contents so that the molar ratio to dodecanedioic acid was 1:1, and the temperature was raised to 290°C. The temperature was raised to 290°C. The reaction was continued for 10 minutes while maintaining the liquid temperature at 290°C. Thereafter, the internal pressure of the reaction system was continuously reduced to 600 Torr over 10 minutes, and the reaction was continued for 20 minutes. During this time, the reaction temperature was continuously raised to 300°C. After completion of the reaction, a pressure of 0.2 MPa was applied to the reactor with nitrogen gas, and the polymer was removed as a strand from a nozzle at the bottom of the polymerization vessel. After water cooling, the polymer was pelletized using a pelletizer.

[0052] Synthesis Example 6: Synthesis of MP10 (30) Sebacic acid was placed in a jacketed reactor equipped with a stirrer, partial condenser, cooler, thermometer, dropping tank, and nitrogen gas inlet tube, and the inside was thoroughly purged with nitrogen. After heating and melting at 170°C, a mixed amine (70:30) of metaxylylenediamine and paraxylylenediamine (MPXDA, manufactured by Mitsubishi Gas Chemical Company, Inc.) was gradually added dropwise while stirring the contents so that the molar ratio to sebacic acid was 1:1, and the temperature was raised to 240°C. After completion of the dropwise addition, the temperature was raised to 260°C and continued for 20 minutes. Thereafter, the pressure inside the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After completion of the reaction, a pressure of 0.2 MPa was applied to the reactor with nitrogen gas, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization vessel. After water cooling, the polymer was pelletized using a pelletizer.

[0053] Synthesis Example 7: Synthesis of PXD10 Sebacic acid was placed in a jacketed reactor equipped with a stirrer, a partial condenser, a thermometer, a dropping tank, and a nitrogen gas inlet tube, and the reactor was thoroughly purged with nitrogen. After heating and melting at 170°C, paraxylylenediamine (PXDA, manufactured by Showa Denko KK) was gradually added dropwise to a molar ratio of 1:1 to sebacic acid while stirring the contents, and the temperature was raised to 240°C. After completion of the dropwise addition, the temperature was raised to 260°C and continued for 20 minutes. Thereafter, the internal pressure of the reaction system was continuously reduced to 0.08 MPa, and the reaction was continued. After completion of the reaction, a pressure of 0.2 MPa was applied to the reactor with nitrogen gas, and the polymer was taken out as a strand from a nozzle at the bottom of the polymerization vessel. The polymer was then cooled with water and pelletized using a pelletizer.

[0054] <Melting Point of Polyamide Resin> Unless otherwise specified, the melting point (Tm) of the polyamide resin was measured by differential scanning calorimetry (DSC) in accordance with ISO 11357. Specifically, a differential scanning calorimeter was used. The resin was placed in the measurement pan of the differential scanning calorimeter, heated to a temperature above the melting point at a heating rate of 10°C / min under a nitrogen atmosphere, and then rapidly cooled before measurement. The measurement conditions were a heating rate of 10°C / min, held at 280°C for 5 minutes, and then cooled to 100°C at a cooling rate of -5°C / min to determine the melting point (Tm). The differential scanning calorimeter used was a "DSC-60" manufactured by Shimadzu Corporation. Table 1 shows the melting points of the polyamide resins used in each example and comparative example.

[0055] <Production of Continuous Thermoplastic Resin Fibers> The thermoplastic resins shown in Table 1 were melt-extruded using a single-screw extruder having a screw diameter of 30 mm, extruded into strands through a die with 60 holes, and stretched while being wound around a roll, to obtain 800 m of continuous thermoplastic resin fiber bundles wound onto a winder. The melting temperature was set to the melting point of the continuous thermoplastic resin + 15°C.

[0056] Example 1 <Method for manufacturing a mixed yarn> Fibers were drawn from a wound body of continuous thermoplastic resin fiber having a length of 1 m or more and a wound body of continuous carbon fiber having a length of 1 m or more, and then spread by air blowing while passing through multiple guides. While spreading, the continuous thermoplastic resin fiber and continuous carbon fiber were bundled, and further uniformed by air blowing while passing through multiple guides. The resulting mixed yarn had a fineness of approximately 13,000 dtex, a fiber count of approximately 13,500 f, a volume ratio of continuous thermoplastic resin fiber to continuous carbon fiber of 1:1, and a proportion of continuous carbon fiber of 61% by mass.

[0057] <TFP Performance> Using a composite fiber sewing machine, TCWM-101, manufactured by Tajima Industries Co., Ltd., the mixed yarn obtained above was used to draw an ellipse measuring 3 cm wide and 10 cm long on a film (50 μm thick) formed from MP10(30) obtained in Synthesis Example 6. The area of ​​the portion deviating from the desired pattern was measured, and the percentage (unit: %) of this area relative to the area of ​​the ellipse measuring 3 cm wide and 10 cm long was calculated. The evaluation was as follows: A: The deviation from the desired pattern was 0.5% or less (for example, the deviation was 0.5% or less inward from the desired pattern) B: The deviation from the desired pattern was more than 0.5% and 1% or less C: The deviation from the desired pattern was more than 1% but 3% or less D: The deviation from the desired pattern was more than 3%

[0058] <Shaping property> Using the blended yarn obtained above, a twill fabric having a basis weight of 300 GSM (Gram per Square Meter) and a size of 70 cm x 70 cm square was produced. A 300 gsm twill fabric 5 was shaped at room temperature in a mold 4 with a 100° inclination as shown in Figure 3(A), and the distance X of the twill fabric 5 that returned from the corner was measured after 1 minute as shown in Figure 3(B). The measurement was carried out at 23°C. A: 2 mm or less B: More than 2 mm and 4 mm or less C: More than 4 mm

[0059] Examples 2 to 5, Comparative Examples 1 and 2 In Example 1, the changes were made as shown in Table 1, but the rest were carried out in the same manner.

[0060]

[0061] In Table 1, the type of resin fiber indicates the type of thermoplastic resin constituting the continuous thermoplastic resin fiber. In Table 1, the melting point of the resin indicates the melting point of the thermoplastic resin constituting the continuous thermoplastic resin fiber. All of the obtained mixed yarns had an impregnation rate of 35% or less and a dispersity of 60% or more.

[0062] As is clear from the above results, the mixed yarns of the present invention were so excellent in softness that they could be subjected to more precise TFP processing (Examples 1 to 5). Furthermore, they also had excellent shaping properties. In contrast, the mixed yarns of the comparative examples were excellent in TFP performance and shaping properties, but were inferior to the mixed yarns of the present invention (Comparative Examples 1 and 2).

[0063] 1. Blended yarn 2. Shape-retaining yarn 3. Desired pattern 4. Mold 5. Twill fabric

Claims

1. A mixed fiber yarn comprising continuous thermoplastic resin fibers and continuous reinforcing fibers, wherein the continuous thermoplastic resin fibers contain diamine units and dicarboxylic acid units, at least 70 mol% of the diamine units are derived from xylylenediamine, and at least 70 mol% of the dicarboxylic acid units are derived from an α,ω-linear aliphatic dicarboxylic acid having 11 to 20 carbon atoms, and the mixed fiber yarn contains a polyamide resin.

2. The mixed fiber yarn according to claim 1, wherein at least 70 mol% of the dicarboxylic acid units are derived from dodecanedioic acid and / or tetradecanedioic acid.

3. The mixed fiber yarn according to claim 1, wherein at least 70 mol% of the dicarboxylic acid units are derived from dodecanedioic acid.

4. The mixed fiber yarn according to any one of claims 1 to 3, wherein 20 to 100 mol% of the diamine units are derived from metaxylylenediamine and 80 to 0 mol% are derived from p-xylylenediamine (however, the total does not exceed 100 mol%).

5. The mixed fiber yarn according to claim 1, wherein at least 70 mol% of the dicarboxylic acid units are derived from dodecanedioic acid and / or tetradecanedioic acid, 20 to 100 mol% of the diamine units are derived from metaxylylenediamine, and 80 to 0 mol% are derived from p-xylylenediamine (however, the total does not exceed 100 mol%).

6. The mixed fiber yarn according to any one of claims 1 to 5, wherein the continuous reinforcing fibers include at least one selected from the group consisting of carbon fibers, glass fibers, and aramid fibers.

7. The mixed fiber yarn according to any one of claims 1 to 6, wherein the number average fiber length of the continuous reinforcing fibers is more than 10 mm.

8. The mixed fiber yarn according to any one of claims 1 to 7, wherein the continuous thermoplastic resin fibers are undrawn fibers.

9. The mixed fiber yarn according to any one of claims 1 to 8, which is for tailored fiber placement processing.

10. A fabric formed from the mixed fiber yarn according to any one of claims 1 to 9.

11. A method for manufacturing a molded article, comprising heat-processing the mixed fiber yarn according to any one of claims 1 to 9.

12. A method for manufacturing a molded article, comprising performing tailored fiber placement processing on the mixed fiber yarn according to any one of claims 1 to 9.

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