Flame-retardant spun yarn, flame-retardant knitted fabrics, and clothing

Abstract

To provide a spun yarn that exhibits flame retardancy while offering an excellent hand feel and yielding a knitted fabric with moderate firmness and stiffness, thereby affording clothing that can be worn comfortably in various settings, including daily life.SOLUTION: There is provided a spun yarn comprising flame-retardant synthetic fibers, flame-retardant cellulose-based fibers, and non-flame-retardant cellulose-based fibers. When the mass of the spun yarn is set to 100 mass%, the spun yarn comprises: the flame-retardant synthetic fibers in an amount of 35 mass% or more and 80 mass% or less; the flame-retardant cellulose-based fibers in an amount of 5 mass% or more and 25 mass% or less; and the non-flame-retardant cellulose-based fibers in an amount of 15 mass% or more and 60 mass% or less. The spun yarn comprises untwisted fiber groups in an untwisted state and wrapped fiber groups wound around the untwisted fiber groups. There are also provided knitted fabrics comprising the spun yarn and clothing comprising the knitted fabrics.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a flame-retardant spun yarn, a flame-retardant knitted fabric using the flame-retardant spun yarn, and clothing using the flame-retardant knitted fabric. [Background technology]

[0002] Various types of flame-retardant knitted fabrics have been proposed. For example, Patent Document 1 discloses a flame-retardant knitted fabric containing 80% by mass or more of spun yarn containing flame-retardant synthetic fiber and cellulose fiber, in which only the spun yarn arranged on the back surface is water-repellent, and the entire back surface is not water-repellent, and the LOI value (limiting oxygen index) is 25 or more, and the evaporative free moisture content measured according to JIS L 1096 is 3 g / 202.5 cm 2 A flame-retardant knitted fabric has been proposed in which the water absorbency of the back surface of the knitted fabric, measured according to the Byreck method, is lower than the water absorbency of the front surface.Patent Document 2 proposes a flame-retardant fabric that contains natural cellulosic fibers containing a phosphorus compound and acrylic fibers containing an antimony compound, and that has a tear strength test of 1.5 kgf or more and a char length of 4 inches or more in a flame retardancy test.

[0003] Patent Document 3 describes a fabric made of spun yarn containing flame-retardant fibers, which has a thickness of 0.6 mm or less and an air permeability of 10 cc / cm 2 Patent Document 4 proposes a fabric that contains a flame-retardant acrylic fiber containing a zinc stannate compound and one or more other fibers selected from the group consisting of natural fibers and chemical fibers, each in a predetermined ratio, and that has an afterflame time of 30 seconds or less in the ISO15025 combustion test. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7438519 [Patent Document 2] Patent No. 6484554 [Patent Document 3] Japanese Patent Publication No. 2023-25402 [Patent Document 4] International Publication WO2023 / 171286 Brochure Summary of the Invention [Problem to be solved by the invention]

[0005] To provide a spun yarn which exhibits flame retardancy, has excellent texture, and gives knitted fabrics with appropriate firmness and stiffness, and to provide clothing which can be worn comfortably in various situations including daily life. [Means for solving the problem]

[0006] The flame-retardant spun yarn of the present disclosure comprises: A spun yarn comprising a flame-retardant synthetic fiber, a flame-retardant cellulosic fiber, and a non-flame-retardant cellulosic fiber, When the mass of the spun yarn is taken as 100% by mass, the spun yarn contains the flame-retardant synthetic fiber in a proportion of 35% by mass or more and 80% by mass or less, the flame-retardant cellulosic fiber in a proportion of 5% by mass or more and 25% by mass or less, and the non-flame-retardant cellulosic fiber in a proportion of 15% by mass or more and 60% by mass or less, The spun yarn includes a group of untwisted fibers in an untwisted state and a group of wrapped fibers wrapped around the group of untwisted fibers.

[0007] The flame-retardant knitted fabric of the present disclosure comprises: A knitted fabric comprising the flame-retardant spun yarn of the present disclosure, In the knitted fabric, when the mass of the knitted fabric is 100% by mass, the knitted fabric contains the flame-retardant synthetic fiber in a proportion of 35% by mass or more and 80% by mass or less, the flame-retardant cellulosic fiber in a proportion of 5% by mass or more and 25% by mass or less, and the non-flame-retardant cellulosic fiber in a proportion of 15% by mass or more and 60% by mass or less.

[0008] The clothing of the present disclosure is clothing comprising the flame-retardant knitted fabric of the present disclosure. [Effects of the Invention]

[0009] The flame-retardant spun yarn of the present disclosure is a spun yarn containing flame-retardant synthetic fibers, flame-retardant cellulosic fibers, and non-flame-retardant cellulosic fibers, and when knitted into a fabric, the knitted fabric exhibits flame retardancy, and the inclusion of cellulosic fibers gives the knitted fabric an excellent texture, moderate firmness and stiffness, and resistance to pilling. This knitted fabric provides clothing that exhibits flame retardancy and can be worn comfortably in various situations, including everyday life. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Background to the present embodiment) In places where fires may occur, such as manufacturing plants, construction sites, welding workshops, etc., wearing flame-retardant clothing has become commonplace from a safety perspective, and various flame-retardant fabrics have been proposed with the aim of achieving both comfort as clothing and flame resistance. Furthermore, fabrics having other properties in addition to flame resistance have also been proposed, and for example, Patent Document 3 above explains that the above-mentioned configuration results in a fabric that is excellent in breathability, waterproofness, wind resistance, and comfort to wear.

[0011] On the other hand, burns and fires caused by fire outbreaks are not limited to the above locations but are also frequently seen in everyday life. In particular, with the recent increase in outdoor activities and the popularity of camping, opportunities for people to come into close contact with flames, such as at barbecues and bonfires, have increased. This has led to an increase in accidents in which flames or sparks that come into contact with clothing quickly spread, resulting in burns to the wearer. Therefore, there has been a trend toward wearing flame-retardant clothing when enjoying activities where fires may occur, in order to reduce the risk of burns that may occur during these activities. However, many of the fabrics used in flame-retardant clothing worn in manufacturing factories and other places are designed to withstand the type of fire that may momentarily come into contact with clothing, such as flames erupting from large furnaces such as blast furnaces or large amounts of flying sparks and embers. Therefore, these fabrics are not necessarily suitable for clothing worn during relaxed outdoor leisure activities, and there is still room for improvement in terms of comfort, texture, ease of movement, etc.

[0012] For example, in the case of tops such as T-shirts, wearing comfort is of utmost importance, and knitted fabrics (e.g., jersey knitted fabrics) that have a moderate firmness and stiffness while not restricting body movement are widely used, and there is a tendency for those containing cellulosic fibers such as cotton fibers (also simply referred to as cotton or cotton wool) and hemp fibers to be preferred. Furthermore, for clothing that is normally worn, pilling must also be considered for appearance reasons. Knitted fabrics, particularly those made with spun yarns containing synthetic fibers, are prone to pilling on the surface of the knitted fabric due to friction during wear and rubbing during washing, which causes synthetic fibers to come off the spun yarn and cause the knitted fabric surface to become fuzzy. It is not easy to provide a knitted fabric that satisfies these requirements for normal clothing while also being flame-retardant. For example, the flame-retardant spun yarn disclosed in the examples of Patent Document 1 is a spun yarn made from a blend of 75% flame-retardant vinylon fiber and 25% cotton fiber. The proportion of cellulosic fiber in the spun yarn, more specifically, the proportion of cotton in the spun yarn, is low, and the texture of the cellulosic fiber may not be fully exhibited. Patent Document 4 proposes a flame-retardant fabric containing a high proportion of cellulosic fiber, but in its examples, the cotton fabric does not exhibit flame retardancy. Patent Document 2 discloses in its examples a method for obtaining a flame-retardant fabric by impregnating a knitted fabric with a flame-retardant treatment solution. However, when flame-retardantization is performed by post-processing, the flame-retardant component attached to the fabric may restrict the movement of the fibers, reducing the flexibility of the fabric. Furthermore, the flame-retardant component may fill the voids between the fibers, impairing the inherent texture of the cellulosic fiber.

[0013] The LOI (Limited Oxygen Index) is generally used as an index for evaluating flame retardancy, and the LOI value often indicates the flammability of a material. However, there are other flame retardancy standards, such as those established by the Japan Fire Retardant Association (JFRA), a public interest incorporated foundation. According to these flame retardancy standards, clothing is recognized as a flame retardant product if it meets the char length, measured using the vertical methane burner method, of a certain value or less. Some clothing (i.e., the fabric that makes up the clothing) may not meet this standard, even if it has a high LOI value. To meet such high flame retardancy standards, it is necessary to increase the proportion of flame-retardant fibers.

[0014] The present inventors conducted extensive research to obtain a flame-retardant spun yarn that allows for the inclusion of a certain amount of non-flame-retardant cellulosic fibers, such as cotton, and that can produce knitted fabrics with the excellent texture inherent to cellulosic fibers. As a result, they discovered that by using flame-retardant cellulosic fibers in addition to flame-retardant synthetic fibers and non-flame-retardant cellulosic fibers, they can obtain a spun yarn that can produce knitted fabrics with moderate firmness and stiffness and excellent flame retardancy. Furthermore, in fabrics made using this spun yarn, and particularly in knitted fabrics made using this spun yarn, they were able to obtain knitted fabrics with high flame retardancy that meet the flame retardancy standards set by the Japan Fire Retardant Association by adjusting the breathability of the knitted fabric by setting the basis weight and density within a certain range. The present embodiment will be described below.

[0015] (Flame-retardant spun yarn) The flame-retardant spun yarn of the present disclosure is a spun yarn containing a flame-retardant synthetic fiber, a flame-retardant cellulosic fiber, and a non-flame-retardant cellulosic fiber. These fibers contained in the spun yarn of the present disclosure are described below.

[0016] <Flame-retardant synthetic fiber> Flame-retardant synthetic fibers are flame-retardant synthetic fibers with an LOI (limiting oxygen index) value of 25 or more as measured according to JIS K7201 (Plastics - Test method for flammability by oxygen index): 2021. Examples of flame-retardant synthetic fibers include fibers obtained by melt-spinning synthetic resins to which a flame retardant has been added, fibers obtained by melt-spinning synthetic resins and then adding a flame retardant as a post-processing step, and fibers obtained by melting synthetic resins that are themselves flame-retardant.

[0017] Specific examples of flame-retardant synthetic fibers include modacrylic fibers, flame-retardant acrylic fibers, flame-retardant polyester fibers, flame-retardant polyolefin fibers, flame-retardant polyamide fibers, flame-retardant polycarbonate fibers, flame-retardant vinylon fibers, meta-aramid fibers, polyimide fibers, para-aramid fibers, polyparaphenylenebenzoxazole fibers, polybenzimidazole fibers, polyetherimide fibers, and polyamideimide fibers. Among the fibers listed here, those that are not given the "flame retardant" designation are those in which the synthetic resin itself is flame-retardant.

[0018] In this embodiment, the flame-retardant synthetic fiber may be at least one selected from the group consisting of modacrylic fiber, flame-retardant polyester fiber, flame-retardant polyolefin fiber, flame-retardant polyamide fiber, and flame-retardant polycarbonate fiber. These synthetic fibers are widely used in clothing, do not make the texture of knitted fabrics extremely hard, and provide fabrics with a texture that is generally acceptable to consumers.

[0019] Examples of polyolefin fibers include polypropylene-based fibers and polyethylene-based fibers. Polypropylene-based fibers are fibers containing polypropylene, and the polypropylene may be a propylene homopolymer or a copolymer containing propylene and a component copolymerizable therewith, with the propylene content exceeding 50 mol%. The component copolymerizable with propylene is not particularly limited, but examples include olefin-based monomers such as ethylene, butene, and methylpentene. The polypropylene is preferably a propylene homopolymer. One type of polypropylene may be used alone, or two or more types may be used in combination.

[0020] Polyester fibers are fibers containing polyester-based resins. Examples of polyester-based resins include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactic acid, polybutylene succinate, and copolymers thereof. The polyester resin may be virgin polyester obtained by condensation polymerization using petroleum-derived and / or plant-derived raw materials, recovered polyester, or so-called recycled polyester. Given the recent trend toward reducing CO2 emissions and the demand for environmentally friendly materials, biomass polyesters polymerized at least in part using plant-derived raw materials and recycled polyesters are used appropriately. Examples of recovered polyesters include, but are not limited to, containers (such as PET bottles for beverages and other liquids) collected for resource recycling purposes, polyesters from clothing, industrial waste polyesters, and rejected or scrap polyesters generated during various processes for producing fibers, films, and other molded products.

[0021] Examples of polyamide fibers include ordinary nylon fibers such as nylon fibers obtained by melt spinning 6,6 nylon or 6-nylon, and wholly aromatic polyamide fibers known as aramid fibers.

[0022] The polycarbonate fiber preferably contains a polycarbonate resin having a number-average molecular weight of 19,000 or less and a branching degree of 0.1 mol% to 0.8 mol%. The number-average molecular weight and branching degree listed here are those after fiberization, and a method for measuring these parameters after fiberization is described in Japanese Patent No. 5,591,046. Alternatively, the polycarbonate fiber may be a polycarbonate fiber that uses a fiber treatment agent containing a specific component, as disclosed in Japanese Patent No. 7,441,484. Preferably, the polycarbonate fiber contains a polycarbonate resin with a number-average molecular weight of 9,000 to 16,000 and a weight-average molecular weight of 22,000 to 32,000.

[0023] Specific examples of flame retardants that impart flame retardancy to these synthetic resin fibers are as follows. Examples of phosphorus-containing compound flame retardants include red phosphorus, phosphate ester compounds, aromatic phosphate ester compounds, oligomeric condensates of aromatic phosphate ester compounds, (metal) phosphates, (metal) organic phosphates, ammonium polyphosphate, thermosetting resin surface-coated ammonium polyphosphate, melamine-modified ammonium polyphosphate, and melamine polyphosphate. Examples of nitrogen-containing compound flame retardants include (iso)cyanurate derivatives, (iso)cyanuric acid derivatives, guanidine derivatives, and urea derivatives. Examples of inorganic compound flame retardants include metal oxides (antimony trioxide, antimony pentoxide, and molybdenum oxide), metal hydroxides (aluminum hydroxide and magnesium hydroxide), metal composite oxides (zirconium-antimony composite oxide), and metal composite hydroxides (zinc hydroxystannate). Examples of bromine-based compound flame retardants include bistribromophenoxyethane, ethylenebistetrabromophthalimide, and ethylenebispentabromophthalimide. The flame retardant may be contained in the synthetic resin fiber in a proportion of, for example, 0.5% by mass or more and 5.0% by mass or less, particularly 0.8% by mass or more and 3.0% by mass or less.

[0024] In this embodiment, modacrylic fibers are more particularly preferred, and even more particularly, modacrylic fibers containing an antimony compound are preferably used, because when modacrylic fibers and modacrylic fibers containing an antimony compound are used together with non-flame retardant fibers, they can prevent the non-flame retardant fibers from burning.

[0025] Modacrylic fibers are fibers containing an acrylonitrile copolymer in which 35% to 85% by mass of acrylonitrile is copolymerized with 15% to 65% by mass of other components. The other components are, for example, halogen-containing vinyl, particularly vinyl chloride, and halogen-containing vinylidene, particularly vinylidene chloride, monomers. The copolymerization of these components results in the resin itself exhibiting high flame retardancy. The proportion of acrylonitrile in modacrylic fibers may be 35% to 65% by mass.

[0026] When the modacrylic fiber contains an antimony compound, the antimony compound is, for example, antimony trioxide, antimony tetroxide, or antimony pentoxide. The antimony compound may be contained in the modacrylic fiber in a proportion of, for example, 1.6% by mass or more and 33% by mass or less. Modacrylic fibers containing an antimony compound are sold, for example, by Kaneka Corporation under the trade name "Protex (registered trademark)."

[0027] The fineness and fiber length of the flame-retardant synthetic fiber are selected taking into consideration spinning properties, etc. The fineness of the flame-retardant synthetic fiber may be, for example, 0.5 dtex to 5.0 dtex, particularly 1.0 dtex to 4.0 dtex, and more particularly 1.5 dtex to 3.5 dtex. The fiber length of the flame-retardant synthetic fiber may be, for example, 25 mm to 70 mm, particularly 30 mm to 60 mm, and more particularly 35 mm to 55 mm.

[0028] <Flame-retardant cellulosic fiber> Flame-retardant cellulosic fibers are flame-retardant cellulosic fibers, specifically synthetic fibers with a limiting oxygen index (LOI) of 25 or higher as measured according to JIS K7201 (Plastics - Test method for flammability by oxygen index):2021. Examples of flame-retardant cellulosic fibers include those spun by adding a flame retardant or a material that can be converted into a flame-retardant component during spinning to the spinning solution (viscose in the case of viscose rayon) before the fiber is spun, and those spun with a flame retardant added during post-processing. Natural fibers such as cotton are generally made flame-retardant by coating or impregnation with a flame retardant.

[0029] Flame-retardant cellulosic fibers include regenerated fibers containing flame retardants, semi-synthetic fibers containing flame retardants, and flame-retardant regenerated fibers, semi-synthetic fibers, and natural cellulosic fibers to which flame retardants have been added through post-processing. Regenerated fibers include rayon and polynosic obtained by the viscose process, cupra obtained by the cuprammonium process, and solvent-spun cellulose fibers such as lyocell (e.g., Tencel®). Semisynthetic fibers include acetate fibers. Natural cellulosic fibers include natural fibers derived from plants such as cotton, hemp, flax, ramie, jute, banana, bamboo, kenaf, shell ginger, hemp, and kapok.

[0030] In this embodiment, the flame-retardant cellulosic fiber may be at least one selected from the group consisting of viscose rayon containing a flame retardant, purified cellulose fiber containing a flame retardant, and acetate fiber containing a flame retardant. The flame-retardant cellulosic fibers listed here are flame-retardant fibers that are imparted with a flame retardant before spinning and are preferably used because they tend to maintain their flame retardancy even after washing. Viscose rayon is particularly widely used in clothing and is preferably used because it imparts a soft feel to knitted fabrics and other woven fabrics. Flame retardants include, for example, phosphorus-containing compounds, halogen-containing compounds, inorganic flame retardants, nitrogen-compound flame retardants, and silicone compounds, as described in relation to flame-retardant synthetic fibers. Flame retardants that are particularly applicable to cellulosic fibers may be phosphorus-containing compounds and halogen-containing compounds. Phosphorus-containing compounds are preferably used because they do not generate halogens when exerting their flame-retardant effect. Examples of phosphorus-containing compounds are as described in relation to flame-retardant synthetic fibers. The proportion of the flame retardant contained in the cellulosic fiber may be, for example, 5% by mass to 50% by mass, in particular 5% by mass to 30% by mass. Examples of viscose rayon containing a flame retardant include the flame-retardant rayon fiber sold by Daiwabo Rayon Co., Ltd. under the trade name "DFG" (registered trademark), and the flame-retardant viscose fiber (flame-retardant modal fiber) "LENZING FR" (registered trademark) sold by Lenzing.

[0031] The fineness and fiber length of the flame-retardant cellulosic fiber are selected in consideration of spinnability, etc. The fineness of the flame-retardant cellulosic fiber may be, for example, 0.5 dtex or more and 7.0 dtex or less, particularly 0.8 dtex or more and 5.0 dtex or less, and more particularly 1.0 dtex or more and 4.5 dtex or less. The thickness of cotton fibers is expressed in micronaires, taking into consideration variations in the diameter of a single fiber, deformation of the cross-sectional shape, and twisting of the fiber. When the flame-retardant cellulosic fiber is cotton, its micronaire is preferably 2.8 or more and 5.5 or less, and more preferably 3.5 or more and 4.9 or less. The flame-retardant cellulosic fibers may have a fiber length of, for example, 25 mm or more and 70 mm or less, particularly 30 mm or more and 60 mm or less, and more particularly 35 mm or more and 55 mm or less.

[0032] <Non-flame retardant cellulosic fiber> Non-flame retardant cellulosic fibers are cellulosic fibers that do not contain flame retardants or have not been post-treated with flame retardants, and have an LOI (limiting oxygen index) value of less than 25 as measured according to JIS K7201 (Plastics - Test method for flammability by oxygen index): 2021. The cellulosic fibers themselves are as described above in relation to flame retardant cellulosic fibers, and cellulosic fibers that have not been given flame retardancy are usually non-flame retardant.

[0033] In this embodiment, the non-flame retardant cellulosic fiber may be at least one selected from the group consisting of cotton fiber, hemp fiber, viscose rayon fiber, refined cellulose fiber, and acetate fiber. These fibers are widely used in clothing, and it is known how they affect the texture and feel of fabrics. Therefore, by appropriately selecting these fibers, the properties of the knitted fabric obtained by knitting the spun yarn can be appropriately adjusted depending on the type of clothing, etc.

[0034] The non-flame-retardant cellulosic fiber may be, in particular, cotton. Cotton fibers are used to impart firmness and resilience to knitted fabrics. Cotton fibers themselves have excellent water and moisture absorption properties, which not only improve the moisture and water absorption properties of knitted fabrics but also reduce the generation of static electricity in knitted fabrics. Furthermore, cotton fibers themselves have a pleasant feel against the skin, which can easily improve the wearing comfort of clothing that comes into contact with the skin (e.g., tops such as T-shirts). Cotton fibers are also easily dyeable and have excellent color development, allowing for a variety of colors and patterns in clothing. Furthermore, because cotton fibers have a long history of use as a natural fiber for clothing, their inclusion in spun yarns (and thus knitted fabrics and clothing) provides a sense of security to end consumers.

[0035] The fineness and fiber length of the non-flame retardant cellulosic fiber are selected taking into consideration spinning properties, etc. The fineness of the non-flame retardant cellulosic fiber may be, for example, 0.5 dtex to 10 dtex, particularly 0.8 dtex to 8.0 dtex, and more particularly 1.0 dtex to 6.0 dtex. When the non-flame retardant cellulosic fiber is a cotton fiber, its micronaire is preferably 2.8 to 5.5, and more preferably 3.5 to 4.9. The fiber length of the non-flame retardant cellulosic fiber may be, for example, 25 mm to 80 mm, particularly 30 mm to 70 mm, and more particularly 35 mm to 65 mm.

[0036] <Flame-retardant spun yarn composition, etc.> The flame-retardant spun yarn of this embodiment (hereinafter also simply referred to as "spun yarn") contains the three types of fibers described above in the following proportions. Flame-retardant synthetic fibers: 35% by mass or more and 80% by mass or less, more preferably 40% by mass or more and 75% by mass or less, particularly 45% by mass or more and 70% by mass or less; Flame-retardant cellulose fibers: 5% by mass or more and 25% by mass or less, more preferably 5% by mass or more and 20% by mass or less, particularly 10% by mass or more and 20% by mass or less, Non-flame retardant cellulose fiber: 15% by mass or more and 60% by mass or less, more preferably 15% by mass or more and 50% by mass or less, particularly preferably 20% by mass or more and 45% by mass or less.

[0037] As described above, flame-retardant synthetic fibers impart flame retardancy to spun yarns, and flame-retardant cellulosic fibers impart flame retardancy to spun yarns and also impart a cellulosic fiber-derived texture to fabrics woven or knitted with the spun yarns. Because non-flame-retardant cellulosic fibers are not flame-retardant, they can be selected relatively freely and play a role in determining the feel and texture of knitted fabrics and other fabrics, as well as properties that affect the comfort of clothing made from the fabric, such as moisture absorption and water absorption. For example, when the non-flame-retardant cellulosic fiber is cotton, it imparts stiffness and firmness to knitted fabrics. The spun yarn may contain two or more types of each of flame-retardant synthetic fibers, flame-retardant cellulosic fibers, and non-flame-retardant cellulosic fibers.

[0038] In the spun yarn of this embodiment, the combined proportion of flame-retardant cellulosic fiber and non-flame-retardant cellulosic fiber may be 20% to 60% by mass, particularly 25% to 55% by mass, and more particularly 30% to 55% by mass. Because the spun yarn of this embodiment contains both flame-retardant and non-flame-retardant cellulosic fibers, the proportion of flame-retardant synthetic fiber required to achieve the same LOI value can be reduced compared to when using only non-flame-retardant cellulosic fiber. Therefore, the spun yarn of this embodiment can more effectively express the properties (particularly tactile feel and texture) derived from cellulosic fiber in knitted fabrics and other woven fabrics. Furthermore, reducing the proportion of synthetic fiber and increasing the proportion of cellulosic fiber required to achieve the same LOI value is desirable from the perspective of the SDGs (Sustainable Development Goals).

[0039] In the spun yarn of this embodiment, the combined proportion of the flame-retardant synthetic fiber and the flame-retardant cellulosic fiber may be 40% by mass or more and 85% by mass or less, particularly 40% by mass or more and 80% by mass or less, or 45% by mass or more and 75% by mass or less. Because the flame-retardant synthetic fiber and the flame-retardant cellulosic fiber are used to make the spun yarn flame-retardant, if the combined proportion of these fibers is too small, the flame retardancy may be insufficient, whereas if the combined proportion is too high, the proportion of the non-flame-retardant cellulosic fiber may be so small that the feel and texture inherent in the non-flame-retardant cellulosic fiber may not be obtained in the knitted fabric or other fabric.

[0040] The spun yarn of this embodiment may have untwisted fibers and wrapping fibers wrapped around the untwisted fibers. Here, "untwisted" refers to a state in which the fibers are parallel to the yarn axis in spun yarns obtained by air spinning, such as Vortex (registered trademark) yarn. In the spun yarn of this embodiment, untwisted fibers are present inside (at the center) of the yarn. Furthermore, when observing the side of the yarn, fibers that completely cross the side of the yarn and are completely in contact with the side of the yarn are considered wrapping fibers. Fibers that do not partially contact the side of the yarn and cannot exert a wrapping force toward the center of the yarn cross section are not considered wrapping fibers. Among fibers that do not fall into either untwisted or wrapping fibers, those with both ends in contact with the side of the yarn are considered floating fibers, and those with one end separated from the side of the yarn are considered fluffy fibers. All fibers that do not fall into any of the wrapping, floating, or fluffy categories are considered untwisted fibers. By giving the spun yarn this structure, the fiber convergence is enhanced, improving the firmness and stiffness of fabrics made using the spun yarn and improving their moisture absorption and quick-drying properties. Spun yarns with this structure are obtained by spinning using a VORTEX (registered trademark) spinning machine (manufactured by Murata Machinery Co., Ltd.), and are sometimes called MVS (Murata Vortex Spinner) yarns. Alternatively, spun yarns spun using a VORTEX spinning machine are sometimes called vortex air spun yarns. When MVS yarns are used to make fabrics such as knitted fabrics, they are less likely to pill and are more likely to impart firmness and stiffness to the fabric.

[0041] The count of the spun yarn of this embodiment is not particularly limited, but may be in the range of 10 to 70 count in British cotton count (1 pound (approximately 454 g) / 840 yards (approximately 768 m) is 1 count. Unless otherwise specified, hereinafter, counts refer to British cotton counts), and is preferably 12 to 60 count, and more preferably 15 to 50 count. The spun yarn of this embodiment may be a single yarn, or a yarn made by twisting together multiple single yarns. Examples of such yarns made up of multiple single yarns include a two-ply yarn (also called a twin yarn) made by twisting together two yarns, a three-ply yarn made by twisting together three single yarns, and a four-ply yarn made by twisting together four single yarns.

[0042] (Flame-retardant knitted fabric) Next, we will explain the flame-retardant knitted fabric of this embodiment (hereinafter also simply referred to as "knitted fabric") knitted using the spun yarn of this embodiment described above. The knitted fabric of this embodiment is not limited in its structure, etc., as long as it contains the spun yarn of this embodiment. For example, the knitted fabric may be weft knitted or warp knitted. If it is weft knitted, the knitted fabric may have at least one knitting structure selected from the group consisting of plain knitting structure, rib knitting structure, purl knitting structure, pique knitting structure, jacquard knitting structure, and mesh knitting structure. In particular, plain knitting structure is also called plain knitting and is used in various clothing. The knitted fabric of this embodiment can also be provided as a plain knitting structure.

[0043] In the knitted fabric of this embodiment, the spun yarn of this embodiment may account for 50% by mass or more, particularly 75% by mass or more, and more particularly 80% by mass or more of the total spun yarns constituting the knitted fabric, and all of the spun yarns constituting the knitted fabric may be the spun yarn of this embodiment. If the proportion of the spun yarn of this embodiment is small, the flame retardancy of the knitted fabric may be insufficient. Alternatively, the knitted fabric of this embodiment may contain the flame-retardant spun yarn of this embodiment so that the proportion of flame-retardant synthetic fibers in the total mass (100% by mass) of the knitted fabric is 35% to 80% by mass, more preferably 40% to 75% by mass, and particularly preferably 45% to 70% by mass; the proportion of flame-retardant cellulosic fibers is 5% to 25% by mass, more preferably 5% to 20% by mass, and particularly preferably 10% to 20% by mass; and the proportion of non-flame-retardant cellulosic fibers is 15% to 60% by mass, more preferably 15% to 50% by mass, and particularly preferably 20% to 45% by mass. As long as the proportions of each fiber satisfy these ranges, the knitted fabric may contain spun yarns other than the spun yarn of this embodiment, and the other spun yarns may be flame-retardant or non-flame-retardant.

[0044] In the knitted fabric of this embodiment, the spun yarn of this embodiment may be formed in a form in which multiple spun yarns are twisted together, such as a two-ply yarn or a three-ply yarn, or the knitted fabric may be formed in a state in which multiple spun yarns are pulled together. When multiple spun yarns are used as twin yarns or pulled together yarns, each spun yarn may be the spun yarn of this embodiment, or the spun yarn of this embodiment may be combined with another spun yarn.

[0045] When the knitted fabric of this embodiment is provided as a single-layer knitted fabric, the weight of the knitted fabric is 150 g / m 2 More than 320g / m 2 The single-layer knitted fabric having a basis weight within this range is suitable for forming thin clothing that has a large area that comes into contact with the skin, such as T-shirts, cut and sewn items, and shirts. When the knitted fabric of this embodiment is provided as a single-layer knitted fabric, the basis weight of the knitted fabric is 170 g / m or less. 2 More than 280g / m 2 may be less than 200 g / m 2 More than 275g / m 2 It may be the following:

[0046] Furthermore, when the knitted fabric of this embodiment is provided as a knitted fabric of a single layer structure, the course density and wale density are appropriately selected depending on the use of the knitted fabric, and are not particularly limited. In this embodiment, for example, the course density (stitches / 0.5 inch) may be 15.0 or more and 25.0 or less, 18.0 or more and 24.0 or less, or 20.0 or more and 24.0 or less. Furthermore, the wale density (stitches / 0.5 inch) may be 12.0 or more and 20.0 or less, 13.0 or more and 19.0 or less, or 14.0 or more and 18.0 or less. When the course density and wale density are within these ranges, by appropriately selecting the count of the spun yarn, and / or by twisting multiple spun yarns together, and / or by using multiple spun yarns in parallel, it is possible to achieve a knitting density of 50 cc / cm or less. 2 ·Seconds or more 250cc / cm 2It is possible to obtain a knitted fabric having an air permeability of 0.1 s or less, making it easy to obtain a knitted fabric with air permeability suited to the intended use of the clothing, etc. Here, the air permeability is measured in accordance with JIS L1096 8.26 Method A (Fragile method): 2010.

[0047] The breathability of a knitted fabric affects the windproof or breathable properties when worn; the smaller the breathability, the higher the windproof properties, and the larger the breathability, the higher the breathability. Furthermore, in this embodiment, the air permeability of the knitted fabric affects the flame retardancy of the knitted fabric. 2 ·Seconds or more 250cc / cm 2 If the permeability is within the range of 1 / 2 seconds or less, not only is the fabric excellent in flame retardancy, but it also provides appropriate breathability to clothing made using the resulting knitted fabric, making the clothing less stuffy in summer and warm in winter. A more preferable breathability of the knitted fabric is 1 / 2 seconds or less when the knitted fabric has a basis weight of 150 g / m, such as a plain knit, rib knit, pearl knit, pique knit, jacquard knit, or mesh knit structure. 2 More than 320g / m 2 For low to medium weight knitted fabrics, the breathability of the knitted fabric is 50cc / cm 2 ·Seconds or more 220cc / cm 2 sec or less, and 60cc / cm 2 ·Seconds or more 200cc / cm 2 It is more preferable that the air permeability of the knitted fabric is within the range of 50 cc / cm 2 or less. 2 ·Seconds or more 80cc / cm 2 If the flame retardancy is kept within the range of 100 cc / cm or less, it will exhibit excellent flame retardancy, meeting the standards set by the Japan Fire Retardant Association. 2 ·Seconds or more 75cc / cm 2 It may be less than a second.

[0048] When the knitted fabric of this embodiment has a single layer structure, the bite length is not particularly limited and may be, for example, 25 cm or more and 40 cm or less per 100 needles (100 wales (w)), more preferably 32 cm or more and 38 cm or less per 100 needles (100 wales (w)). Furthermore, in the knitted fabric of the single layer structure of this embodiment, the cover factor of the knitted fabric structure determined in accordance with JIS L 1096 8.8:2010 may be 0.05 or more and 0.08 or less, or 0.055 or more and 0.075 or less, but is not limited thereto. Furthermore, the thickness and bulk density of the single-layer knitted fabric of this embodiment are not particularly limited, and for example, the thickness may be 0.6 mm or more and 1.2 mm or less, or 0.7 mm or more and 1.0 mm or less. The bulk density is 0.15 g / cm. 3 More than 0.35g / cm 3 may be less than or equal to 0.2 g / cm 3 More than 0.3g / cm 3 It may be the following:

[0049] The knitted fabric of this embodiment may be one or more types selected from the group consisting of knitted fabrics having a multilayer structure, fleece knitted fabrics, and fleece-back knitted fabrics (hereinafter, these knitted fabrics are collectively referred to as "double-sided knitted fabrics"). In double-sided knitted fabrics, the front yarn that constitutes the front surface and the back yarn that constitutes the back surface are separate. Therefore, the appearances of the front and back surfaces are generally different. However, for example, in cardboard knitted fabrics, the front yarn and back yarn may be the same, and the knitted fabric of the front yarn and the knitted fabric of the back yarn may have the same structure, and these may be connected with a middle yarn. In this case, the front and back surfaces have the same appearance and the same structure.

[0050] When the knitted fabric is a double-faced knitted fabric, the face yarn and back yarn may contain the spun yarn of this embodiment so that the proportion of flame-retardant synthetic fiber in the entire knitted fabric is 35% by mass or more and 80% by mass or less, more preferably 40% by mass or more and 75% by mass or less, and particularly preferably 45% by mass or more and 70% by mass or less; the proportion of flame-retardant cellulosic fiber is 5% by mass or more and 25% by mass or less, more preferably 5% by mass or more and 20% by mass or less, and particularly preferably 10% by mass or more and 20% by mass or less; and the proportion of non-flame-retardant cellulosic fiber is 15% by mass or more and 60% by mass or less, more preferably 15% by mass or more and 50% by mass or less, and particularly preferably 20% by mass or more and 45% by mass or less.

[0051] When the knitted fabric of this embodiment is a double-sided knitted fabric, both the front yarn and the back yarn may contain the spun yarn of this embodiment. Because the front yarn and the back yarn are independent, if only one of the front yarn and the back yarn contains the flame-retardant spun yarn of this embodiment, the flame retardancy of the side knitted with the yarn that does not contain the flame-retardant spun yarn may be insufficient, and ultimately the flame retardancy of the entire knitted fabric may be insufficient. When the double-sided knitted fabric contains a middle yarn, the middle yarn may also contain the spun yarn of this embodiment.

[0052] The spun yarns of this embodiment contained in the front yarn and the back yarn may be different or the same. In either case, it is preferable that the proportion of non-flame-retardant fibers contained in the entire yarn constituting the front yarn is 50% by mass or less, and the proportion of non-flame-retardant fibers contained in the entire yarn constituting the back yarn is 50% by mass or less. If the proportion of non-flame-retardant fibers contained in the front yarn and the back yarn exceeds 50% by mass, the flame retardancy of the knitted fabric may be insufficient. The proportion of non-flame-retardant fibers contained in the entire front yarn and the entire back yarn may particularly be 25% by mass or more and 50% by mass or less, or 30% by mass or more and 45% by mass or less. Here, the non-flame retardant fiber includes not only the non-flame retardant cellulosic fiber constituting the spun yarn of this embodiment, but also non-flame retardant synthetic fibers, wool fibers, etc. When the face yarn is a two-ply yarn or a pulled-along yarn (two or more spun yarns pulled-along without twisting together and used as a single yarn) made of the spun yarn of this embodiment and another spun yarn, it is preferable to select the composition of the other spun yarn so that the proportion of non-flame retardant fiber in the entire face yarn falls within the above range.

[0053] A fleece knitted fabric is a knitted fabric in which loop pile is knitted with a back yarn, and a fleece knitted fabric is a knitted fabric in which loop pile knitted with a back yarn is raised, and the front and back surfaces have different appearances. Fleece knitted fabrics and fleece knitted fabrics are widely used in sweatshirts, sweatpants, etc. Knitted fabrics used in sweatshirts, etc. are often knitted in a plain stitch pattern with a front yarn, and have a slightly larger basis weight, which provides relatively high heat retention, and the loop pile or raised portion provides good water absorption.

[0054] The fleece knitted fabric and the fleece knitted fabric may each be a knitted fabric having a face yarn, a middle yarn, and a back yarn, or may be an inlay knitted fabric without a middle yarn. The knitting structure knitted with the face yarn may be a plain knit (plain knit structure) or may be another structure. The number of jumps of the back yarn in the fleece knitted fabric and the fleece knitted fabric is not particularly limited and may be, for example, 1 to 5. Furthermore, the yarn supply ratio may be, for example, when the middle yarn is 1.00, the face yarn may be 1 to 2 and the back yarn may be 0.3 to 0.8. In the case of an inlay knitted fabric, the yarn supply ratio may be, for example, when the face yarn is 1.00, the back yarn may be 0.3 to 0.8.

[0055] When the knitted fabric of this embodiment is a double-sided knitted fabric, the basis weight is, for example, 250 g / m 2 More than 550g / m 2 The double-sided knitted fabric can easily exhibit its properties (for example, heat retention) by having a relatively large basis weight. When the knitted fabric of this embodiment is a double-sided knitted fabric, the basis weight is 280 g / m 2 More than 520g / m 2 may be less than or equal to 300 g / m 2 More than 500g / m 2 It may be the following:

[0056] Furthermore, when the knitted fabric of this embodiment is a double-face knitted fabric, the course density and wale density are appropriately selected depending on the use of the knitted fabric, and are not particularly limited. In this embodiment, when the knitted fabric is a fleece knitted fabric or a fleece-back knitted fabric, the course density (stitches / 0.5 inches) of the knitted structure formed by the face yarn (the face yarn and the middle yarn, if a middle yarn is used) may be 15.0 or more and 25.0 or less, 16.0 or more and 22.0 or less, or 17.0 or more and 20.0 or less. Furthermore, the wale density (stitches / 0.5 inches) may be 10.0 or more and 18.0 or less, 11.0 or more and 16.0 or less, or 12.0 or more and 15.0 or less. When the double-face knitted fabric is a cardboard knitted fabric in which the face yarn and the back yarn each independently form a knitted structure, each knitted structure may have a course density and wale density within the above ranges.

[0057] When the knitted fabric of this embodiment is a double-face knitted fabric, if the course density and wale density of the knitted fabric are within these ranges, it is possible to obtain a yarn density of 50 cc / cm or more by appropriately selecting the count of the spun yarn, and / or by twisting together a plurality of spun yarns, and / or by using a plurality of spun yarns in parallel. 2 ·Seconds or more 150cc / cm 2 It is possible to obtain a knitted fabric having an air permeability of 55 cc / cm or less, and it becomes easy to obtain a knitted fabric having air permeability suitable for the intended use of clothing, etc. The method for measuring the air permeability is as explained above in relation to the knitted fabric of a single layer structure. When the knitted fabric of this embodiment is a double-face knitted fabric, the air permeability is not particularly limited, and is 55 cc / cm or less. 2 ·Seconds or more 120cc / cm 2 60cc / cm 2 ·Seconds or more 110cc / cm 2 It may be less than a second.

[0058] As explained in relation to the single-layer knitted fabric, the breathability of the knitted fabric also affects the windproof or breathable properties when worn on the double-sided knitted fabric. Furthermore, the breathability of the knitted fabric also affects the flame retardancy of the knitted fabric. In particular, for the double-sided knitted fabric, the breathability of the knitted fabric is set to 50 cc / cm 2 ·Seconds or more 80cc / cm2 - Seconds and below, especially 60cc / cm 2 ·Seconds or more 75cc / cm 2 If the time is kept within the range of 10 seconds or less, it will exhibit excellent flame retardancy that meets the standards set by the Japan Fire Retardant Association (public interest incorporated foundation).

[0059] When the knitted fabric of this embodiment is a double-sided knitted fabric, the bite length in the structure formed by the face yarn (when a middle yarn is present, the face yarn and the middle yarn) is not particularly limited, and may be, for example, 40 cm or more and 60 cm or less per 100 needles (100 wales (w)). Furthermore, when the knitted fabric of this embodiment is a double-sided knitted fabric, the cover factor of the structure formed by the face yarn (when a middle yarn is present, the face yarn and the middle yarn) calculated in accordance with JIS L 1096 8.8:2010 may be, but is not limited to, 0.030 or more and 0.06 or less. Furthermore, when the knitted fabric of this embodiment is a double-sided knitted fabric, its thickness and bulk density are not particularly limited, and for example, the thickness may be 1.0 It may be 1.2 mm or more and 2.0 mm or less, and 1.4 mm or more and 2.5 mm or less, and 1.2 mm or more and 2.0 mm or less, and 1.4 The thickness may be 1.8 mm or more and the bulk density may be 0.15 g / cm 3 More than 0.30g / cm 3 may be less than or equal to 0.18 g / cm 3 More than 0.26g / cm 3 It may be 0.20 g / cm or less. 3 More than 0.25g / cm 3 It may be the following:

[0060] (Clothing) The knitted fabric of the present embodiment described above may be used to form clothing such as outerwear (jackets, coats, etc.), bottoms (trousers, skirts, etc.), tops (shirts, blouses, T-shirts, tunics, cut-and-sew tops), socks, underwear (camisoles, trunks, undershirts), hosiery, gloves, scarves, etc. These clothing items may be everyday wear or uniforms.

[0061] The knitted fabric of this embodiment contains spun yarns containing flame-retardant synthetic fibers, flame-retardant cellulosic fibers, and non-flame-retardant cellulosic fibers in predetermined proportions, resulting in flame retardancy, a strong display of the cellulosic fiber characteristics, and the non-flame-retardant cellulosic fiber characteristics. For example, if the flame-retardant cellulosic fiber contains flame-retardant viscose rayon and the non-flame-retardant cellulosic fiber contains cotton, the cotton fiber provides firmness and stiffness to the fabric, while the viscose rayon provides a soft feel, resulting in a flame-retardant knitted fabric with a pleasant texture. Such knitted fabrics are particularly suitable for making T-shirts, polo shirts, sweatshirts, sweatpants, cut-and-sew items, and the like.

[0062] Furthermore, the knitted fabric of this embodiment can change its feel and texture by changing the types and proportions of the flame-retardant cellulosic fibers and non-flame-retardant cellulosic fibers, and therefore can be provided with the same feel, thickness, appearance, etc. as conventional knitted fabrics. Therefore, the knitted fabric of this embodiment makes it possible to provide clothing that can be worn safely during activities such as barbecues and bonfires without any restrictions on clothing design, and that has the same high design quality as clothing made with ordinary knitted fabrics. [Example]

[0063] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples.

[0064] (Production of spun yarns (Examples 1 to 5, Comparative Example 1)) Example 1 Antimony compound-containing modacrylic fiber (manufactured by Kaneka Corporation, trade name "Protex (registered trademark) C Type", fineness 1.7 dtex, fiber length 38 mm), flame-retardant viscose rayon (manufactured by Daiwabo Rayon Co., Ltd., fineness 1.7 dtex, fiber length 38 mm), and cotton fiber (American cotton fiber, Micronaire 3.5 to 4.9, average fiber length 27 mm) were used, weighed out in the proportions shown in Table 1, and then fed sequentially through a cotton-blending process, a carding process, a combing process, and a drawing process to obtain a sliver. The obtained sliver was supplied to the draft zone of a VORTEX spinning machine (manufactured by Murata Machinery Co., Ltd., model number "VORTEX861") and drafted, and then spun and wound up under conditions of a spinning speed of 300 m / min, a spindle diameter of 1.1 mm, and a nozzle pressure of 0.5 MPa to obtain the spun yarn of Example 1, which was a single yarn with a British cotton count of 20 and contained 45% by mass of modacrylic fiber, 15% by mass of flame-retardant cellulose fiber, and 40% by mass of cotton fiber as a non-flame-retardant cellulose-based fiber.

[0065] Example 2 The sliver produced when producing the spun yarn of Example 1 was used to produce an MVS yarn in the same spinning frame as that used to produce the spun yarn of Example 1. At this time, the total draft of the spinning frame was adjusted to produce a finer yarn, and the spun yarn of Example 2 was obtained, which was a single yarn with a British cotton count of 30, containing 45% by mass of modacrylic fiber, 15% by mass of flame-retardant cellulose fiber, and 40% by mass of cotton fiber as a non-flame-retardant cellulosic fiber.

[0066] Example 3 A spun yarn was produced in the same manner as the spun yarn of Example 1, except that the same modacrylic fiber, flame-retardant viscose rayon, and cotton fiber as those used in producing the spun yarn of Example 1 were used, and were weighed so that the modacrylic fiber was 65% by mass, the flame-retardant viscose rayon was 10% by mass, and the cotton fiber was 25% by mass.This gave the spun yarn of Example 3, which is a single yarn with a British cotton count of 20, containing 65% by mass of modacrylic fiber, 10% by mass of flame-retardant cellulose fiber, and 25% by mass of cotton fiber as a non-flame-retardant cellulosic fiber.

[0067] Example 4 The sliver produced when producing the spun yarn of Example 3 was used to produce an MVS yarn in the same spinning frame as that used to produce the spun yarn of Example 3. At this time, the total draft of the spinning frame was adjusted to produce a finer yarn, and the spun yarn of Example 4 was obtained, which was a single yarn with a British cotton count of 25, containing 65% by mass of modacrylic fiber, 10% by mass of flame-retardant cellulose fiber, and 25% by mass of cotton fiber as a non-flame-retardant cellulosic fiber. Example 5 The sliver produced when producing the spun yarn of Example 3 was used to produce an MVS yarn in the same spinning frame as that used to produce the spun yarn of Example 3. At this time, the total draft of the spinning frame was adjusted to produce a finer yarn, and the spun yarn of Example 5 was obtained, which was a single yarn with a British cotton count of 30, containing 65% by mass of modacrylic fiber, 10% by mass of flame-retardant cellulose fiber, and 25% by mass of cotton fiber as a non-flame-retardant cellulosic fiber.

[0068] (Comparative Example 1) The sliver produced when producing the spun yarn of Example 1 was used, and in a ring spinning frame equipped with a compact spinning system, air was used to suck in the direction of travel of the roving to converge the fibers, and then twisted to obtain the spun yarn of Comparative Example 1 (silo compact yarn), which was a single yarn with a British cotton count of 40 and contained 45% by mass of modacrylic fiber, 15% by mass of flame-retardant cellulose fiber, and 40% by mass of cotton fiber as a non-flame-retardant cellulosic fiber. Table 1 shows the production conditions and physical properties of the spun yarns of Examples 1 to 5 and Comparative Example 1.

[0069] [Table 1]

[0070] The count of the spun yarn is measured by the following method. <Constant weight cotton count (British cotton count)> Measurements were made in accordance with the cotton count measurement method for measuring the correct tex and count of general spun yarns in JIS L 1095 9.4.1:2010.

[0071] (Examples 6 to 11, Comparative Example 2) Knitted fabrics with a plain knit structure (plain knit structure) were produced using the spun yarns (Examples 1 to 4 and Comparative Example 1) shown in Table 1. The method for producing each knitted fabric is as follows.

[0072] Example 6 Using the spun yarn of Example 1, a plain knitted fabric having a yarn length of 32.0 cm / 100 needles and the course density and wale density shown in Table 1 was produced on a circular knitting machine (30 inch 22 gauge).

[0073] Example 7 Two spun yarns of Example 2 were plied together and used as plied yarns. A plain knit fabric (plied tight jersey) with a yarn length of 32.0 cm / 100 needles and the course and wale counts shown in Table 1 was produced on a circular knitting machine (30 inches, 22 gauge).

[0074] Example 8 Using the spun yarn of Example 3, a plain knit fabric having a yarn length of 32.0 cm / 100 needles and the course density and wale density shown in Table 1 was produced on a circular knitting machine (34 inches, 20 gauge).

[0075] Example 9 Using the spun yarn of Example 3, a plain knit fabric having a yarn length of 32.0 cm / 100 needles and the course density and wale density shown in Table 1 was produced on a circular knitting machine (34 inches, 20 gauge).

[0076] Example 10 Using the spun yarn of Example 4, a plain knitted fabric having a yarn length of 32.0 cm / 100 needles and the course density and wale density shown in Table 1 was produced on a circular knitting machine (30 inch 24 gauge).

[0077] Example 11 Using the spun yarn of Example 4, a plain knitted fabric having a yarn length of 32.0 cm / 100 needles and the course density and wale density shown in Table 1 was produced on a circular knitting machine (30 inch 24 gauge).

[0078] (Comparative Example 2) Using the spun yarn of Comparative Example 1, a plain knit fabric having a yarn length of 32.0 cm / 100 needles and the course density and wale density shown in Table 1 was produced on a circular knitting machine (30 inch 22 gauge).

[0079] (Comparative Example 3) Using commercially available polyester spun yarn (100% polyester MVS yarn, count: 40), a plain knit fabric with a yarn length of 32.0 cm / 100 needles and the course and wale counts shown in Table 1 was produced on a circular knitting machine (30 inch, 24 gauge). The measurement results of the physical properties and flame retardancy of each of the knitted fabrics of Examples 6 to 11 and Comparative Examples 2 and 3 are shown in Table 2. The methods for measuring the physical properties and flame retardancy of the knitted fabrics are as described below.

[0080] [Table 2]

[0081] (Examples 12 and 13) Spun yarns were selected from the spun yarns shown in Table 1, and fleece knitted fabrics were produced using the selected spun yarns. The manufacturing method for each knitted fabric is as follows.

[0082] Example 12 Using the spun yarn of Example 2 as the face yarn and middle yarn, and the spun yarn of Example 1 as the back yarn, a fleece knit fabric was produced on a 30-inch, 11-gauge single knitting machine for fleece, according to the conditions shown in Table 3 below. The face yarn and middle yarn were used to form plain stitches on the face, and on the back, loop pile was knitted while the back yarn was inserted into the face yarn every two stitches to produce a fleece knit fabric. The knitted fabric obtained was scoured and then dyed with a cationic dye and a reactive dye to obtain a fleece knit fabric. The knitted fabric obtained was a fleece knit fabric with a plain stitch surface layer and a loop pile back layer.

[0083] Example 13 Using the spun yarn of Example 5 as the face yarn and middle yarn, and a plied yarn formed by pliedly plying two spun yarns of Example 3 as the back yarn, a fleece knitted fabric was produced on a 30-inch, 11-gauge single knitting machine for fleece under the conditions shown in Table 3 below. The knitted fabric obtained was scoured and then dyed with a cationic dye and a reactive dye to obtain a fleece knitted fabric. The knitted fabric obtained was a fleece knitted fabric in which the face yarn and middle yarn had a plain knit structure (jersey knit structure) and the back yarn formed loop pile. The measurement results of the physical properties and flame retardancy of the knitted fabrics having the fleece knit structure of Examples 12 and 13 are shown in Table 3. The methods for measuring the physical properties and flame retardancy of the knitted fabrics are as described below.

[0084] [Table 3]

[0085] The methods for measuring the physical properties and flame retardancy of the knitted fabric will be described below. <Course number, Wale number, number parameters> The course density and wale density of the obtained knitted fabric were measured in accordance with JIS L 1096:2010 8.6.2 Knit fabric density. That is, the obtained knitted fabric was placed on a flat table, and after removing any unnatural wrinkles or tension, the number of wales and number of courses per 0.5 inches (25.4 mm) were measured visually at five different locations using a magnifying glass (magnification: 10x). The degree parameter was calculated from the obtained course degree and Wale degree according to the formula [(course degree) x 2] x [(Wale degree) x 2].

[0086] <Bite length> From the obtained knitted fabric, 100 wales were visually picked out, and the yarn length was measured to determine the bite length.

[0087] <stitch length> The bite length (cm) was divided by 100 and multiplied by 10 to obtain the stitch length (mm) in the wale direction.

[0088] <Cover Factor> The cover factor of the obtained knitted fabric was measured in accordance with JIS L 1096:2010 8.8b) Cover factor.

[0089] <Balance weight, thickness, bulk density, and specific volume> The basis weight and thickness were measured in accordance with JIS L 1096: 2010. The bulk density and specific volume were calculated based on the basis weight and thickness.

[0090] <Breathability> The breathability of the obtained knitted fabric was measured in accordance with JIS L 1096:2010 8.26.1 Method A (Fragile method).

[0091] <Anti-pilling> The obtained knitted fabrics were evaluated for anti-pilling properties to assess their resistance to pilling. The anti-pilling properties were evaluated by conducting a pilling test using an ICI type testing machine based on JIS L1076 Method A:2012 and checking the degree of pilling. The higher the grade in the pilling test, the higher the anti-pilling properties.

[0092] <Flame retardant performance> A.LOI value To evaluate the flame retardancy of the resulting knitted fabric, the Limited Oxygen Index (LOI) value of the knitted fabric was measured according to JIS L 1091E method (E-2) for the initial (unwashed) and washed samples. For the washed sample, the knitted fabric was washed 10 times according to JIS L 1930:2019, Home Laundry Test Method for Textile Products, C4M method, and the Limited Oxygen Index was measured. (W10) B. Vertical methane burner method In accordance with the vertical methane burner method established by the Japan Fire Retardant Association (a public interest incorporated foundation), the sample was washed five times in accordance with the JIS L 1930:2019 C4M method for home washing tests for textile products. Five specimens (two or three in the vertical direction, and three or two in the horizontal direction) were then taken from the sample, tests were conducted on these specimens, and the char length was measured and the average value was calculated.

[0093] The plain knit fabrics (plain knit fabrics) of Examples 6 to 11, which are knit fabrics containing the spun yarns of Examples 1 to 5, and the fleece knit fabrics of Examples 12 and 13 all showed LOI values ​​of 26 or more. These results show that by using the flame-retardant spun yarn of this embodiment, knit fabrics with high flame retardancy can be obtained, regardless of the type of knitting structure.

[0094] The knitted fabrics of Examples 7, 8, and 12 had char lengths measured using a vertical methane burner method below a certain value, and met the flame retardancy standards set by the Japan Fire Retardant Association (a public interest incorporated foundation), demonstrating even higher flame retardancy. The knitted fabric of Example 7 was made using a double-ply yarn in which two yarns were plied together, and the coarse stitch and wale stitch counts were slightly increased, resulting in a high density and moderately reduced breathability, which is presumably responsible for its excellent flame retardancy. The knitted fabrics of Examples 8 and 12 were made using a spun yarn with a relatively low content of non-flame-retardant fibers, and the coarse stitch and wale stitch counts were slightly increased, resulting in a high density and moderately reduced breathability, which is presumably responsible for its excellent flame retardancy.

[0095] Furthermore, all of the Examples (Examples 6 to 13) contained viscose rayon and cotton fibers, and thus had firmness and stiffness, while also having a soft feel due to the viscose rayon. On the other hand, the knitted fabric of Comparative Example 2, which used the spun yarn of Comparative Example 1, which was produced using a ring spinning machine equipped with a (silo) compact spinning system and which did not contain untwisted fibers or wound fibers wound around the untwisted fibers, showed an LOI value of 26 or more, but suffered from a lot of pilling. Furthermore, the knitted fabric of Comparative Example 1 had less firmness and stiffness than the knitted fabrics of the Examples.

[0096] The present embodiment includes the following aspects. (Aspect 1) A spun yarn comprising a flame-retardant synthetic fiber, a flame-retardant cellulosic fiber, and a non-flame-retardant cellulosic fiber, When the mass of the spun yarn is taken as 100% by mass, the spun yarn contains the flame-retardant synthetic fiber in a proportion of 35% by mass or more and 80% by mass or less, the flame-retardant cellulosic fiber in a proportion of 5% by mass or more and 25% by mass or less, and the non-flame-retardant cellulosic fiber in a proportion of 15% by mass or more and 60% by mass or less, The spun yarn includes a group of untwisted fibers in an untwisted state, and a group of wrapped fibers wrapped around the group of untwisted fibers. (Aspect 2) When the mass of the spun yarn is 100% by mass, the spun yarn contains the flame-retardant synthetic fiber and the flame-retardant cellulosic fiber in a total ratio of 40% by mass to 80% by mass, The spun yarn of Aspect 1, wherein the spun yarn contains the flame-retardant cellulosic fiber and the non-flame-retardant cellulosic fiber in a total ratio of 20% by mass to 60% by mass, when the mass of the spun yarn is 100% by mass. (Aspect 3) The spun yarn of Aspect 1 or 2, wherein the flame-retardant synthetic fiber is at least one fiber selected from the group consisting of modacrylic fiber, flame-retardant polyester fiber, flame-retardant polyolefin fiber, flame-retardant polyamide fiber, and flame-retardant polycarbonate fiber. (Aspect 4) The spun yarn of any of Aspects 1 to 3, wherein the flame-retardant cellulosic fiber is at least one selected from the group consisting of viscose rayon containing a flame retardant, purified cellulose fiber containing a flame retardant, and acetate fiber containing a flame retardant. (Aspect 5) The spun yarn of any of Aspects 1 to 4, wherein the non-flame retardant cellulosic fiber is at least one fiber selected from the group consisting of cotton fiber, hemp fiber, viscose rayon fiber, refined cellulose fiber, and acetate fiber. (Aspect 6) A knitted fabric including the spun yarn of any one of aspects 1 to 5, In the knitted fabric, when the mass of the knitted fabric is 100% by mass, the knitted fabric contains the flame-retardant synthetic fiber in a proportion of 35% by mass or more and 80% by mass or less, the flame-retardant cellulosic fiber in a proportion of 5% by mass or more and 25% by mass or less, and the non-flame-retardant cellulosic fiber in a proportion of 15% by mass or more and 60% by mass or less. (Aspect 7) the knitted structure is one or more selected from the group consisting of a plain knitted structure, a milled knitted structure, a pearl knitted structure, a pique knitted structure, a jacquard knitted structure, and a mesh knitted structure; Weight is 150g / m 2 More than 320g / m 2 is as follows: The course size (size / 0.5 inches) is 15.0 or more and 25.0 or less, The knitted fabric of embodiment 6, wherein the wale size (stitches / 0.5 inches) is 12.0 or more and 20.0 or less. (Aspect 8) Air permeability is 50cc / cm 2 ·Seconds or more 250cc / cm 2 The knitted fabric of aspect 6 or 7, which is less than sec. (Aspect 9) The knitted fabric of any one of Aspects 6 to 8, wherein the knitted fabric is one or more selected from the group consisting of knitted fabrics having a multilayer structure, fleece knitted fabrics, and fleece-back knitted fabrics. (Aspect 10) a face yarn that substantially constitutes the surface of the knitted fabric and a back yarn that substantially constitutes the back of the knitted fabric each include the spun yarn of any one of aspects 1 to 5; The knitted fabric of aspect 9, wherein the proportion of non-flame retardant fibers contained in all the yarns constituting the face yarn is 50% by mass or less, and the proportion of non-flame retardant fibers contained in all the yarns constituting the back yarn is 50% by mass or less. (Aspect 11) Weight is 250g / m 2 More than 550g / m 2 is as follows: The course size (size / 0.5 inches) is 15.0 or more and 25.0 or less, The knitted fabric of aspect 9 or 10, wherein the wale size (stitches / 0.5 inches) is 10.0 or more and 18.0 or less. (Aspect 12) Air permeability is 50cc / cm 2 ·Seconds or more 150cc / cm 2 The knitted fabric of aspect 9, which is less than or equal to 10 seconds. (Aspect 13) A garment comprising the knitted fabric of any one of aspects 6 to 12. [Industrial Applicability]

[0097] The spun yarn of the present disclosure is flame retardant, has excellent texture, and produces knitted fabrics with moderate firmness and stiffness. Therefore, knitted fabrics containing the spun yarn of the present disclosure are suitable for use in various clothing, and clothing containing the knitted fabric of the present disclosure is suitable for wearing during outdoor leisure activities that involve fire, such as barbecues and bonfires.

Claims

1. A spun yarn comprising a flame-retardant synthetic fiber, a flame-retardant cellulosic fiber, and a non-flame-retardant cellulosic fiber, When the mass of the spun yarn is taken as 100% by mass, the spun yarn contains the flame-retardant synthetic fiber in a proportion of 35% by mass or more and 80% by mass or less, the flame-retardant cellulosic fiber in a proportion of 5% by mass or more and 25% by mass or less, and the non-flame-retardant cellulosic fiber in a proportion of 15% by mass or more and 60% by mass or less, The spun yarn includes a group of untwisted fibers in an untwisted state, and a group of wrapped fibers wrapped around the group of untwisted fibers.

2. When the mass of the spun yarn is taken as 100% by mass, the spun yarn contains the flame-retardant synthetic fiber and the flame-retardant cellulosic fiber in a total ratio of 40% by mass to 80% by mass, 2. The spun yarn according to claim 1, wherein the spun yarn contains the flame-retardant cellulosic fiber and the non-flame-retardant cellulosic fiber in a total ratio of 20% by mass to 60% by mass, when the mass of the spun yarn is 100% by mass.

3. 2. The spun yarn according to claim 1, wherein the flame-retardant synthetic fiber is at least one fiber selected from the group consisting of modacrylic fiber, flame-retardant polyester fiber, flame-retardant polyolefin fiber, flame-retardant polyamide fiber, and flame-retardant polycarbonate fiber.

4. 2. The spun yarn according to claim 1, wherein the flame-retardant cellulosic fiber is at least one selected from the group consisting of viscose rayon containing a flame retardant, purified cellulose fiber containing a flame retardant, and acetate fiber containing a flame retardant.

5. 2. The spun yarn according to claim 1, wherein the non-flame retardant cellulosic fiber is at least one fiber selected from the group consisting of cotton fiber, hemp fiber, viscose rayon fiber, refined cellulose fiber, and acetate fiber.

6. A knitted fabric comprising the spun yarn according to claim 1, In the knitted fabric, when the mass of the knitted fabric is 100% by mass, the knitted fabric contains the flame-retardant synthetic fiber in a proportion of 35% by mass or more and 80% by mass or less, the flame-retardant cellulosic fiber in a proportion of 5% by mass or more and 25% by mass or less, and the non-flame-retardant cellulosic fiber in a proportion of 15% by mass or more and 60% by mass or less.

7. the knitted structure is one or more selected from the group consisting of a plain knitted structure, a milled knitted structure, a pearl knitted structure, a pique knitted structure, a jacquard knitted structure, and a mesh knitted structure; Weight is 150g / m ２ 320g / m or more ２ is as follows: The course size (size / 0.5 inches) is 15.0 or more and 25.0 or less, 7. The knitted fabric according to claim 6, wherein the wale density (stitches / 0.5 inch) is 12.0 or more and 20.0 or less.

8. Air permeability is 50cc / cm 2 ・Seconds or more 250cc / cm 2 The knitted fabric according to claim 6, wherein the knitted fabric has a length of 1 / 2 seconds or less.

9. The knitted fabric according to claim 6, wherein the knitted fabric is one or more selected from the group consisting of knitted fabrics having a multilayer structure, fleece knitted fabrics, and fleece-back knitted fabrics.

10. a face yarn that substantially constitutes a surface of the knitted fabric and a back yarn that substantially constitutes a back surface of the knitted fabric each include the spun yarn according to claim 1; The knitted fabric according to claim 9, wherein the proportion of non-flame retardant fibers contained in all the yarns constituting the face yarn is 50% by mass or less, and the proportion of non-flame retardant fibers contained in all the yarns constituting the back yarn is 50% by mass or less.

11. Weight is 250g / m ２ More than 550g / m ２ is as follows: The course size (size / 0.5 inches) is 15.0 or more and 25.0 or less, The knitted fabric according to claim 9, wherein the wale density (stitches / 0.5 inches) is 10.0 or more and 18.0 or less.

12. Air permeability is 50cc / cm 2 ・Seconds or more 150cc / cm 2 The knitted fabric according to claim 9, wherein the knitted fabric has a length of 1 / 2 seconds or less.

13. A garment comprising the knitted fabric according to any one of claims 6 to 12.

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