Flame-retardant recycled knitted fabric and fiber product

Abstract

To provide a flame-retardant recycled knitted fabric and a fiber product consisting of a flame-retardant recycled fiber and an unused flame-retardant fiber, having flame-retardant performance and excellent appearance quality suitable for protective clothing applications.SOLUTION: The knitted fabric comprises a flame-retardant recycled fiber and an unused flame-retardant fiber and is dyed with a cationic dye.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a flame-retardant recycled woven or knitted fabric and a textile product which are made using flame-retardant recycled fibers and unused flame-retardant fibers and have flame retardant performance and excellent appearance quality suitable for protective clothing applications. [Background technology]

[0002] Conventionally, flame-retardant fibers have excellent heat resistance and combustibility, and therefore have been used as flame-retardant fabrics for work clothes that may be exposed to flames, such as those used by firefighters, electric power companies, and chemical companies. Even if flame-retardant fabrics made of flame-retardant fibers such as aramid fibers (fully aromatic polyamide fibers) are used, their performance deteriorates with use, and they are eventually discarded due to stains, rubbing, tears, fraying, and the like. In addition, cutting waste is generated at each stage of manufacturing flame-retardant fabrics and when sewing work clothes. As a result, waste and used products generated at each of these processes are generated as waste. Most of these process waste and used products are used for industrial purposes, and are rarely reused, with most of them being incinerated or landfilled.

[0003] Meanwhile, in recent years, there has been a demand for reducing resource consumption, reducing the burden on the environment, and forming a recycling-oriented society (for example, Patent Documents 1 and 2). Specifically, for used products of general-purpose fibers, old fibers such as rags from old clothes and waste fibers have been recycled. It is also possible to apply the same recycling methods as for general-purpose fiber products to waste materials from each process and used products of flame-retardant fabrics.

[0004] However, because flame-retardant fibers have superior heat resistance and flame retardancy compared to general-purpose fibers, there was a problem that, when a known fiber spreader was used under the same conditions as for general-purpose fiber products, malfunctions occurred and efficient and sufficient fiber spreading could not be performed. In the case of woven and knitted fabrics containing flame-retardant fibers, high-performance recycled fibers obtained by spreading and retreading waste generated in products and processes are currently used to manufacture textile products such as felt and work gloves by processing them into cotton or yarn, but no woven and knitted fabrics that can be used for protective clothing applications that require a high level of appearance have yet been proposed. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2006-233409 A [Patent Document 2] JP 2005-105491 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a flame-retardant recycled woven or knitted fabric and a textile product which are made using flame-retardant recycled fibers and unused flame-retardant fibers and have flame retardant performance and excellent appearance quality suitable for protective clothing applications. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to achieve the above object and have completed the present invention. Thus, the following invention is provided.

[0008] 1. A flame-retardant recycled woven or knitted fabric, comprising flame-retardant recycled fibers and unused flame-retardant fibers, and dyed with a cationic dye. 2. A flame-retardant recycled woven or knitted fabric comprising a flame-retardant recycled fiber obtained by opening a woven fabric or a textile product using said woven fabric, which is made using spun yarn and satisfies the following formula (I), and an unused flame-retardant fiber, and characterized in that the flame-retardant recycled woven or knitted fabric is dyed with a cationic dye. Twist factor x fabric packing density≦4.5 (I) 3. The flame-retardant recycled woven or knitted fabric according to item 2 above, wherein the spun yarn is blended with flame-retardant fibers having a limiting oxygen index of 25 or more as measured by JIS L1091 E method in an amount of 40% or more by weight based on the weight of the spun yarn. 4. A flame-retardant recycled woven or knitted fabric according to any one of 1 to 3 above, wherein the woven or knitted fabric is made using spun yarn, and the flame-retardant recycled fiber is blended in the spun yarn in an amount of 10 to 50% by weight of the entire spun yarn. 5. A flame-retardant recycled woven or knitted fabric according to any one of 1 to 4 above, wherein the woven or knitted fabric is made using spun yarn, and the spun yarn is blended with unused flame-retardant fibers having a fiber length of 30 to 200 mm and a limit oxygen index of 25 or more as measured by JIS L1091 E method in an amount of 50 to 90% by weight of the entire spun yarn. 6. The flame-retardant recycled woven or knitted fabric according to any one of 1 to 5 above, wherein the flame-retardant recycled fibers and / or unused flame-retardant fibers are one or more types of fibers selected from the group consisting of meta-aramid fibers, para-aramid fibers, polyparaphenylene benzoxazole fibers, polybenzimidazole fibers, polybenzimidazole fibers, polyimide fibers, polyetherimide fibers, polyamideimide fibers, carbon fibers, polyphenylene sulfide fibers, polyvinyl chloride fibers, flame-retardant rayon, modacrylic fibers, flame-retardant acrylic fibers, flame-retardant polyester fibers, flame-retardant vinylon fibers, melamine fibers, fluorine fibers, flame-retardant wool, and flame-retardant cotton. 7. The flame-retardant recycled woven or knitted fabric according to any one of 1 to 6 above, wherein the flame-retardant recycled woven or knitted fabric is a woven or knitted fabric using spun yarn, and the unused flame-retardant fiber is a meta-aramid fiber, and the meta-aramid fiber accounts for 50 to 90% by weight of the entire spun yarn. 8. The flame-retardant recycled woven or knitted fabric according to any one of 1 to 7 above, wherein the unused flame-retardant fiber is a meta-aramid fiber having a residual solvent content of 0.1% by weight or less and a crystallinity of 5 to 35%. 9. The flame-retardant recycled woven or knitted fabric according to any one of 1 to 8 above, wherein the flame-retardant recycled woven or knitted fabric is a woven or knitted fabric using spun yarn, and the spun yarn contains conductive fiber. 10. The flame-retardant recycled woven or knitted fabric according to any one of 1 to 9 above, wherein the unused flame-retardant fiber is a meta-aramid fiber, and the color difference between the flame-retardant recycled fiber and the meta-aramid fiber is 3 or less. 11. A textile product comprising the flame-retardant recycled woven or knitted fabric described in any one of 1 to 10 above. Effect of the Invention

[0009] According to the present invention, there are provided flame-retardant recycled woven / knitted fabrics and textile products which are made using flame-retardant recycled fibers and unused flame-retardant fibers and have flame retardant performance and excellent appearance quality suitable for protective clothing applications. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. First, the flame-retardant recycled woven or knitted fabric (also called "woven or knitted fabric" or "fabric") of the present invention contains flame-retardant recycled fibers and unused flame-retardant fibers.

[0011] The flame-retardant recycled fiber and / or unused flame-retardant fiber is preferably a flame-retardant fiber having a limiting oxygen index of 25 or more as measured by JIS L1091-1999 E method. Examples of such flame-retardant fibers include meta-aramid fibers (sometimes called "meta-type wholly aromatic polyamide fibers"), para-aramid fibers (sometimes called "para-type wholly aromatic polyamide fibers"), polyparaphenylene benzoxazole fibers, polybenzimidazole fibers, polyimide fibers, polyetherimide fibers, polyamideimide fibers, carbon fibers, polyphenylene sulfide fibers, polyvinyl chloride fibers, flame-retardant rayon, modacrylic fibers, flame-retardant acrylic fibers, flame-retardant polyester fibers, flame-retardant vinylon fibers, melamine fibers, fluorine fibers, flame-retardant wool, and flame-retardant cotton. One or more of these flame-retardant fibers can be used.

[0012] Among them, meta-aramid fiber, i.e., metaphenylene isophthalamide fiber (commercially available products include "Teijin Conex" and "Teijin Conex Neo" (trademarks) manufactured by Teijin Limited, and "Nomex" (trademarks) manufactured by DuPont) are useful because of their excellent limiting oxygen index and excellent mechanical properties. Furthermore, it is also preferable to mix para-aramid fiber, i.e., paraphenylene terephthalamide fiber (commercially available products include "Twaron" (trademarks) manufactured by Teijin Limited, and "Kevlar" (trademarks) manufactured by Toray DuPont Co., Ltd.) and coparaphenylene-3,4'-oxydiphenylene terephthalamide fiber (commercially available products include "Technora" (trademarks) manufactured by Teijin Limited).

[0013] These flame-retardant fibers may contain additives such as antioxidants, ultraviolet absorbers, heat stabilizers, flame retardants, titanium oxide, colorants, inert fine particles, etc., within the scope of the invention.

[0014] The flame-retardant recycled fiber is preferably a woven fabric made of spun yarn and satisfying the following formula (I), or a fiber obtained by opening a textile product made of the woven fabric. Twist factor x fabric packing density≦4.5 (I) Here, the twist coefficient can be calculated by K=T / √n, where K is the twist coefficient, T is the number of twists per inch (2.54 cm), and n is the English cotton count. The twist coefficient K is preferably in the range of 2.5 to 6.0 in terms of the physical properties and flexibility of the fabric. In particular, it is preferably 2.5 to 4.5 for single yarns and 3.0 to 6.0 for two-ply yarns. The spun yarn may be either single yarn or two-ply yarn, and the twist coefficient is calculated from the number of twists of the final yarn. In the case of a single yarn fabric (a fabric made of a single spun yarn), the twist coefficient is calculated from the number of first twists of the single yarn, and in the case of a two-ply fabric (a fabric made of a two-ply spun yarn), the twist coefficient is calculated from the number of top twists of the two-ply yarn.

[0015] The fabric packing density T is calculated as follows: T = (ta1 + ta2) / (tm1 + tm2) Here, ta1 is the amount of yarn that actually occupies one complete weave in the warp direction, and is the warp density per cm (threads / cm). Similarly, ta2 is the amount of yarn that actually occupies one complete weave in the weft direction, and is the weft density per cm (threads / cm). tm1 is the amount of the theoretically largest yarn that occupies one complete weave in the warp direction, and tm2 is the amount of the theoretically largest yarn that occupies one complete weave in the weft direction. tm can be expressed by the following formula. tm=e / ((ei)×3.14×d / 4+2id) Here, e is the number of threads in the warp direction of one complete structure in the case of tm1 (the weft direction in the case of tm2), and i is the number of crossings in the warp direction of one complete structure in the case of tm1 (the weft direction in the case of tm2). In the present invention, it is preferable that e and i have the same value in the warp direction and the weft direction, but they may be different.

[0016] Furthermore, d is the diameter of the thread and can be expressed by the following formula: d(cm)=0.00357×√((tex / (φ×ρf)) Here, tex is the value obtained by converting the spun yarn count into tex, φ is the yarn packing ratio, and ρf is the specific gravity of the fiber. For simplicity, the yarn packing ratio φ is calculated as 1 in this application.

[0017] If the twist number of the spun yarn is high, it may become difficult to open the fibers during the disintegration and de-piling processes. Also, if the fabric packing density is too high, it may become difficult to open the fibers during the disintegration and de-piling processes. If the product of the twist coefficient and the fabric packing density is 4.5 or less (more preferably 0.1 to 4.0), it is preferable because opening the fibers during the disintegration and de-piling processes becomes easier.

[0018] The woven fabric preferably contains the flame-retardant fiber as a constituent fiber of the spun yarn, and more preferably contains the flame-retardant fiber in an amount of 40% by weight or more based on the weight of the spun yarn.

[0019] The spun yarn contained in the woven fabric is preferably composed only of the above-mentioned flame-retardant fibers, but may contain non-flame-retardant fibers (fibers with a limiting oxygen index of less than 25 as measured by JIS L 1091-1999 E method). In this case, examples of non-flame-retardant fibers include polyester fibers, nylon fibers, rayon fibers, polynosic fibers, lyocell fibers, acrylic fibers, vinylon fibers, cotton, hemp, wool, etc. One or more of these non-flame-retardant fibers can be used.

[0020] These non-flame retardant fibers may contain additives such as antioxidants, ultraviolet absorbers, heat stabilizers, flame retardants, titanium oxide, colorants, inert fine particles, conductive particles, etc., as long as the object of the present invention is not impaired.

[0021] The woven fabric having the above-mentioned structure can be recycled into fibers efficiently and easily and sufficiently. The woven fabric may be an unused flame-retardant spun yarn woven fabric, a used flame-retardant spun yarn woven fabric, process waste generated during the manufacture of a woven fabric, sewing waste generated during sewing, etc.

[0022] The woven fabric or a textile product using the woven fabric (hereinafter, sometimes referred to as a "flame-retardant spun yarn product") is washed in advance as necessary, and then subjected to a crushing treatment after applying an oil agent as necessary, and the crushed material obtained is opened to form a cotton-like material, thereby obtaining a flame-retardant recycled fiber. An example of a method for producing a flame-retardant recycled fiber from a flame-retardant spun yarn product is described below.

[0023] The textile product is not particularly limited as long as it is a product containing the woven fabric. Specific examples include flame-retardant work clothes, firefighting suits, work gloves, industrial materials (woven fabrics, knitted fabrics), etc., containing flame-retardant spun yarn. It is preferable that the above-mentioned flame-retardant spun yarn is used alone in such textile products. However, yarns other than the flame-retardant spun yarn may be included, and such yarns are preferably spun yarns. In this case, it is preferable that the content of the flame-retardant spun yarn is 50% by weight or more (preferably 50 to 100% by weight) of the entire textile product. Used textile products include not only used products, but also fiber waste and residuals generated in the process of manufacturing textile products. Each process will be described in detail below.

[0024] First, it is preferable to wash the above-mentioned textile product in advance. This washing process removes dirt adhering to the used textile product, as well as impurities such as plastic and metal powder, and oil. As a result, the occurrence of equipment troubles can be suppressed and efficient recycling can be performed. In particular, it is preferable to thoroughly wash work gloves, since they contain metal pieces or plastic pieces and have oil attached thereto. In addition, washing is also preferable in terms of improving the quality of the recycled product. In addition, it is possible to check whether the textile product as the raw material can be recycled, and to check whether the product contains machine parts such as bolts or various miscellaneous objects. The washing method is not particularly limited, and known means may be used.

[0025] In addition, in consideration of humidity, weather, etc., an oil may be applied to the textile product to be recycled before or during the crushing process described below, as necessary. The application of this oil is not limited to before or during the crushing process, but may be applied to the crushed material before or during the opening, or to the cotton-like material before or during spinning. By applying the oil in this way, it is possible to suppress the generation of static electricity in the crushing process, the opening process, and the spinning process, and it becomes possible to carry out the process smoothly. The oil is not particularly limited as long as it is an oil that is mainly used in normal spinning. Examples of the oil include an oil that combines a smoothing agent such as an animal or vegetable oil or a mineral oil, an alkyl phosphate ester potassium salt, and a surfactant (anionic surfactant, cationic surfactant, or nonionic surfactant), and an oil that further contains a high-viscosity polymeric substance and colloidal silica. The amount of the oil applied is not particularly limited, but it is preferably 2% by weight or less (more preferably 0.1 to 2% by weight) of the weight of the used textile product.

[0026] Next, the textile product is subjected to a disintegration process. This disintegration process mechanically breaks down and separates the used textile product into threads, fragments, and cotton-like materials, making the fiber-opening process easier than directly opening up the product, and fainting can be promoted. The disintegration process is not particularly limited as long as it can achieve the above-mentioned purpose, and known means such as biting, tearing, and ripping can be used. The more the length of the short fibers in the cotton-like material obtained in the subsequent fiber-opening process is close to its original length, the more likely it is that the product will be regenerated into a spun yarn with high tensile strength recovery. Therefore, in the disintegration process, a process that increases the content of short fibers as close to their original length as possible is preferable.

[0027] In addition, it is preferable to perform a cutting process in which the flame-retardant spun yarn product is roughly cut as a pre-process of the disintegration process. In this case, it is preferable to lengthen the cutting interval so as to increase the content of short fibers as close to the original length as possible depending on the form of the product. For example, the product is cut at intervals equal to or longer than the length of the short fibers of the spun yarn used in the textile product. It is also preferable to disintegrate such products by biting, tearing, or pulling them out. Furthermore, it is also preferable to scrape or scrape as a fiber-opening process. It is also preferable to perform the cutting process, disintegration process, and fiber-opening process in a single process, as this is more efficient.

[0028] The conditions of the opening process vary depending on the shape of the textile product, the type of flame-retardant fiber used in the product, or the type of opening machine, and appropriate conditions can be determined by conducting appropriate tests depending on the textile product used as the raw material. However, it is preferable to select the opening conditions so that the cotton-like material obtained by the opening process contains 50% by weight or more of short fibers with a length of 20 mm or more. It is also preferable to select the opening conditions so that the cotton-like material obtained by the opening process contains 50% by weight or more of short fibers having a length of 40% or more of the short fiber length of the spun yarn used in the original product. As described above, the more short fibers with a long length, in other words, a length close to the original fiber length, the higher the recovery of the tensile strength of the regenerated spun yarn (the ratio of the tensile strength of the recycled flame-retardant spun yarn to the tensile strength of the commercially available spun yarn) can be. The fiber length distribution can be easily measured using a staple diagram according to "JIS L 1015-2010 8.4.1 A method".

[0029] The fiber opening can be carried out using a known fiber-recovering machine or fiber-opening machine to obtain flame-retardant recycled fibers. The flame-retardant recycled woven or knitted fabric of the present invention can be produced by preferably blending the above-mentioned flame-retardant recycled fiber with unused flame-retardant fiber as described above to obtain a spun yarn (hereinafter sometimes referred to as "recycled flame-retardant spun yarn"), which is then knitted, woven, and dyed with a cationic dye.

[0030] Here, in the recycled flame-retardant spun yarn, it is preferable to blend the flame-retardant recycled fiber in an amount of 10 to 50% by weight relative to the weight of the spun yarn. Also, unused flame-retardant fiber is mixed in an amount of 90% or less by weight (preferably 50 to 90% by weight, more preferably 60 to 80% by weight) of the entire recycled flame-retardant spun yarn.

[0031] By mixing unused staple fibers, there is an advantage that the tensile strength of the spun yarn can be more effectively restored. As the unused staple fibers, staple fibers with crimps are preferable. This is because the presence of crimps makes it easier to open strands or tow-shaped fibers. In addition, staple fibers with a length of 30 mm or more (more preferably 30 to 200 mm) are preferable. If the length of unused staple fibers is long, the amount of cotton-like material obtained in the present invention is greater, the fibers are entangled for a longer period, and the binding effect is enhanced, so that the regenerated flame-retardant spun yarn with a more restored tensile strength can be obtained. The unused staple fibers used in the present invention include (a) commercially available flame-retardant fiber staples, or (b) staple fibers obtained from fiber waste or remaining products generated in the process of manufacturing long flame-retardant fibers or products made of the long fibers. It is preferable that these have a length of 30 to 200 mm and have crimps that make it easier to open. The short fibers of (b) can be obtained by cutting fiber waste or residuals generated during the production of long flame-retardant fibers or products made of said long fibers. It is preferable that the virgin flame-retardant fiber contains meta-aramid fiber in an amount of 50 to 100% by weight based on the total weight of the virgin fibers.

[0032] Such meta-aramid fibers are those in which aromatic rings constituting the main skeleton are meta-bonded by amide bonds, and 85 mol % or more of the total repeating units of the polymer are metaphenylene isophthalamide units. In particular, polymetaphenylene isophthalamide homopolymer is preferred. The third component that can be copolymerized at 15 mol % or less (preferably 5 mol % or less) of the total repeating units includes, as diamine components, aromatic diamines such as paraphenylenediamine, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, paraxylylenediamine, biphenylenediamine, 3,3'-dichlorobenzidine, 3,3'-dimethylbenzidine, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, and 1,5-naphthalenediamine. Also, as acid components, aromatic dicarboxylic acids such as terephthalic acid, naphthalene-2,6-dicarboxylic acid, and naphthalene-2,7-dicarboxylic acid can be mentioned. In addition, in these aromatic diamines and aromatic dicarboxylic acids, some of the hydrogen atoms in the aromatic ring may be substituted with halogen atoms or alkyl groups such as methyl groups. When 20% or more of the total terminals of the polymer are blocked with a monovalent diamine such as aniline or a monovalent carboxylic acid component, this is preferred because it reduces the decrease in strength of the fiber when it is kept at high temperatures for a long time. Commercially available products of such meta-type wholly aromatic polyamide fibers include Conex (trade name) and Nomex (trade name), and an example of an easily dyeable meta-type wholly aromatic polyamide fiber is Conex Neo (trade name).

[0033] Such meta-type wholly aromatic polyamides can be produced by known interfacial polymerization methods, and the degree of polymerization of the polymer is preferably such that the intrinsic viscosity (IV) of the polymer measured in an N-methyl-2-pyrrolidone solution having a concentration of 0.5 g / 100 ml is in the range of 1.3 to 1.9 dl / g.

[0034] The meta-type wholly aromatic polyamide may contain an alkylbenzenesulfonate onium salt. Examples of the alkylbenzenesulfonate onium salt include hexylbenzenesulfonate tetrabutylphosphonium salt, hexylbenzenesulfonate tributylbenzylphosphonium salt, and dodecylbenzenesulfonate tetraphenylphosphonium salt. Examples of suitable compounds include dodecylbenzenesulfonate, tributyltetradecylphosphonium salt, dodecylbenzenesulfonate tetrabutylphosphonium salt, dodecylbenzenesulfonate tributylbenzylammonium salt, etc. Among these, dodecylbenzenesulfonate tetrabutylphosphonium salt and dodecylbenzenesulfonate tributylbenzylammonium salt are preferred because they are easily available, have good thermal stability, and have high solubility in N-methyl-2-pyrrolidone.

[0035] In order to obtain a sufficient effect of improving dyeability, the content of the alkylbenzenesulfonic acid onium salt is preferably 2.5 mol % or more (preferably in the range of 3.0 to 7.0 mol %) relative to the poly-m-phenyleneisophthalamide.

[0036] The method of mixing poly-m-phenylene isophthalamide and an onium salt of alkylbenzenesulfonic acid may be, for example, a method of mixing and dissolving poly-m-phenylene isophthalamide in a solvent, and then dissolving the onium salt of alkylbenzenesulfonic acid in the solvent. The dope thus obtained is formed into fibers by a known method.

[0037] For the purpose of improving dyeability and resistance to fading, the polymer used for the meta-type wholly aromatic polyamide fiber may have an aromatic diamine component or an aromatic dicarboxylic acid halide component different from the main structural unit of the repeating structure copolymerized as a third component in an aromatic polyamide skeleton containing a repeating structural unit represented by the following formula (1) in an amount of 1 to 10 mol % based on the total amount of the repeating structural units of the aromatic polyamide. -(NH-Ar1-NH-CO-Ar1-CO)- Formula (1) Ar1 is a divalent aromatic group having a linking group in a meta- or parallel axial direction.

[0038] As the third component, it is possible to copolymerize aromatic diamines or aromatic dicarboxylic acid dichlorides represented by the following formulas (2), (3), (4) and (5). Specific examples of the aromatic diamines shown in formulas (2) and (3) include p-phenylenediamine, chlorophenylenediamine, methylphenylenediamine, acetylphenylenediamine, aminoanisidine, benzidine, bis(aminophenyl)ether, bis(aminophenyl)sulfone, diaminobenzanilide, diaminoazobenzene, etc. Specific examples of the aromatic dicarboxylic acid dichlorides shown in formulas (4) and (5) include terephthalic acid chloride, 1,4-naphthalenedicarboxylic acid chloride, 2,6-naphthalenedicarboxylic acid chloride, 4,4'-biphenyldicarboxylic acid chloride, 5-chloroisophthalic acid chloride, 5-methoxyisophthalic acid chloride, bis(chlorocarbonylphenyl)ether, etc.

[0039] H2N-Ar2-NH2...Formula (2) H2N-Ar2-Y-Ar2-NH2... formula (3) XOC-Ar3-COX...Formula (4) XOC-Ar3-Y-Ar3-COX...Formula (5) Ar2 is a divalent aromatic group different from Ar1, Ar3 is a divalent aromatic group different from Ar1, Y is at least one atom or functional group selected from the group consisting of an oxygen atom, a sulfur atom, and an alkylene group, and X is a halogen atom.

[0040] The crystallinity of the meta-aramid fiber is preferably 5 to 35% in terms of good dye exhaustion and easy adjustment to a target color with less dye or under weak dyeing conditions, and more preferably 15 to 25% in terms of low surface uneven distribution of the dye, high resistance to discoloration, and dimensional stability required for practical use.

[0041] Moreover, the amount of the remaining solvent in the meta-aramid fibers is preferably 0.1% by weight or less (more preferably 0.001 to 0.1% by weight) so as not to impair the excellent flame retardant performance of the meta-aramid fibers.

[0042] The meta-aramid fibers can be produced by the following method, and the degree of crystallinity and the amount of remaining solvent can be set within the above ranges by the method described below. The polymerization method for the meta-type wholly aromatic polyamide polymer is not particularly limited, and may be, for example, the solution polymerization method or interfacial polymerization method described in JP-B-35-14399, U.S. Pat. No. 3,360,595, JP-B-47-10863, etc.

[0043] The spinning solution is not particularly limited, but may be an amide-based solvent solution containing an aromatic copolyamide polymer obtained by the above-mentioned solution polymerization or interfacial polymerization, or may be a solution obtained by isolating the polymer from the above-mentioned polymerization solution and dissolving it in an amide-based solvent. Examples of the amide-based solvent used here include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and dimethylsulfoxide, with N,N-dimethylacetamide being particularly preferred.

[0044] The copolymerized aromatic polyamide polymer solution obtained as described above is stabilized by further containing an alkali metal salt or an alkaline earth metal salt, which allows use at a higher concentration and at a lower temperature, and is therefore preferred. The alkali metal salt and the alkaline earth metal salt are preferably present in an amount of 1% by weight or less, more preferably 0.1% by weight or less, based on the total weight of the polymer solution. In the spinning and coagulation step, the spinning solution obtained above (meta-type wholly aromatic polyamide polymer solution) is spun into a coagulation liquid and coagulated.

[0045] The spinning device is not particularly limited, and a conventionally known wet spinning device can be used. In addition, the number of spinning holes, arrangement, hole shape, etc. of the spinneret do not need to be particularly limited as long as it can perform stable wet spinning, and for example, a multi-hole spinneret for staple fibers having 1000 to 30000 holes and a spinning hole diameter of 0.05 to 0.2 mm may be used. In addition, the temperature of the spinning solution (meta-type wholly aromatic polyamide polymer solution) when spun from the spinneret is suitably in the range of 20 to 90°C.

[0046] The coagulation bath used to obtain the fibers is an aqueous solution of an amide solvent, preferably NMP, containing substantially no inorganic salts and having a concentration of 45 to 60% by weight, with the bath temperature in the range of 10 to 50°C. If the concentration of the amide solvent (preferably NMP) is less than 45% by weight, the skin will be thick, the washing efficiency in the washing step will decrease, and it will be difficult to reduce the amount of solvent remaining in the fibers. On the other hand, if the concentration of the amide solvent (preferably NMP) exceeds 60% by weight, uniform coagulation cannot be achieved even in the interior of the fibers, and therefore it may be difficult to reduce the amount of solvent remaining in the fibers. The appropriate immersion time of the fibers in the coagulation bath is in the range of 0.1 to 30 seconds.

[0047] Next, the fiber is stretched at a stretch ratio of 3 to 4 times in a plastic stretching bath containing an amide solvent, preferably an aqueous solution of NMP having a concentration of 45 to 60% by weight, and the bath temperature is set to a range of 10 to 50°C. After stretching, the fiber is thoroughly washed by passing through an aqueous solution of NMP having a concentration of 20 to 40% by weight at 10 to 30°C, followed by a warm water bath at 50 to 70°C. The washed fiber is subjected to a dry heat treatment at a temperature of 270 to 290°C to obtain meta-aramid fiber that satisfies the above range of crystallinity and residual solvent amount. In the meta-aramid fiber, the fiber form may be long fiber (multifilament) or short fiber. In particular, short fiber having a fiber length of 25 to 200 mm is preferable in terms of blending with other fibers. In addition, the single fiber fineness is preferably in the range of 0.8 to 5 dtex.

[0048] The method for mixing the flame-retardant recycled fiber and the unused flame-retardant fiber is not particularly limited, and may be a known mixing method such as a method for blending cotton and polyethylene terephthalate fiber. Also, the unused staple fiber may be mixed during spinning, preferably during the cotton blending process.

[0049] The spun yarn may also contain conductive fibers, and although there are no particular limitations on such conductive fibers, conductive fibers dyeable with cationic dyes are preferred. For example, acrylic conductive fibers, cationic dyeable polyester conductive fibers, cationic dyeable nylon conductive fibers, etc. are preferred. In particular, such conductive fibers are core-sheath type composite fibers containing a conductive agent in the core, and the core polymer contains a conductive agent, and the sheath polymer is preferably made of cationic dyeable polyester or cationic dyeable nylon.

[0050] Methods for producing spun yarn from a cotton-like material or a mixture of a cotton-like material and unused staple fibers (hereinafter simply referred to as spinning methods) are well established in the art, and may be followed. Specific examples of spinning methods include cotton spinning, worsted, woolen, linen spinning, silk spinning, and tow spinning. These methods may also be combined as appropriate. Of these, in the present invention, it is preferable to use the cotton spinning, worsted, and woolen spinning methods. More specifically, suitable examples of the spinning methods include spinning methods consisting of a mixed-blow cotton process, a rowing process, a pre-spinning process, and a fine spinning process. Each process of the cotton spinning method is described below.

[0051] The carding process is a process in which the cotton-like material, the bulk density of which has been reduced by the opening process, is finally separated into individual fibers to produce a sliver, which is an assembly of infinitely long fibers in the form of a cord. The carding process can be carried out using a known carding machine. In particular, in the present invention, the carding process is preferably carried out using a flat card. The sliver preferably contains 50% by weight or more of staple fibers having a length of 20 mm or more and / or 50% by weight or more of staple fibers having a length of 40% or more of the staple fiber length of the spun yarn used in the flame-retardant spun yarn product. The fiber length distribution can be easily measured by a staple diagram according to JIS L 1015:2010 8.4.1 A method.

[0052] The pre-spinning process is an intermediate adjustment process for adjusting the fiber arrangement and thickness of the sliver produced in the sliver-making process to be supplied to the spinning process. Usually, several sets of top and bottom rollers are combined and other devices are attached to stretch the sliver and improve the fiber arrangement (this process is called drafting). The pre-spinning process is further divided into a drawing process and a roving process. The drawing process is a process in which the sliver with poor fiber arrangement immediately after the sliver-making process is drafted mainly to improve the arrangement, and is usually repeated several times. The roving process is a process in which the thickness of the sliver is gradually reduced to an appropriate thickness. The spinning process refers to a process in which the roving obtained in the roving process is supplied to the sliver to be finally adjusted to the desired thickness (count), and twisted and wound up as desired. Usually, twisting and winding are performed simultaneously in this process. The equipment for the spinning process can be a known ring spinning frame, air jet spinning frame, or open-end spinning frame.

[0053] The spun yarn obtained as described above preferably contains 20% by weight or more of staple fibers having a length of 20 mm or more. As described above, the more the long staple fibers are contained, the higher the recovery of tensile strength can be. The fiber length distribution can be easily measured by staple diagram according to JIS L 1015:2010 8.4.1 Method A.

[0054] A recycled flame-retardant spun yarn containing 20% ​​by weight or more (preferably 35% by weight or more, more preferably 50% by weight or more) of short fibers having a length of about 20 mm or more has an effect that the ratio of the tensile strength of the recycled flame-retardant spun yarn to the tensile strength of unused flame-retardant spun yarn is high, and as a result, it can be used in a wider range of applications. Specifically, the tensile strength of the recycled flame-retardant spun yarn is preferably 15 to 100% (more preferably 35 to 100%, even more preferably 60 to 100%) of the tensile strength of unused flame-retardant spun yarn. The tensile strength of the spun yarn is measured according to "JIS L 1095:2010 9.5". Furthermore, the recycled flame-retardant spun yarn has the advantage that it can be made into a thinner yarn and is soft and has a good texture.

[0055] The fabric is then woven and formed into a fabric, and dyed with a cationic dye to obtain the flame-retardant recycled woven or knitted fabric of the present invention. When multiple fiber types are used, a dyeing method suitable for each fiber type may be used as necessary. Examples of dyes include cationic dyes, disperse dyes, and threne dyes.

[0056] Cationic dyes are water-soluble dyes that are soluble in water and have a group that exhibits basicity, and are often used for dyeing acrylic fibers, natural fibers, or cationic dyeable polyester fibers. Cationic dyes can be selected as appropriate, and examples include diacrylmethane and triacrylmethane dyes, quinoneimines (azine, oxazine, thiazine), xanthenes, methines (polymethines, azamethines), heterocyclic azo dyes (thiazole azo, triazole azo, benzothiazole azo), and anthraquinone dyes. Cationic dyes that have been made dispersible by blocking basic groups may also be used. As such dyes, azo dyes are preferable, and examples of azo dyes include CI Basic Blue 54, CI Basic Blue 3, CI Basic Red 29, and CI Basic Yellow 67.

[0057] A carrier agent may also be used, and such a carrier agent is preferably one or more selected from the group consisting of DL-β-ethylphenethyl alcohol, 2-ethoxybenzyl alcohol, 3-chlorobenzyl alcohol, 2,5-dimethylbenzyl alcohol, 2-nitrobenzyl alcohol, p-isopropylbenzyl alcohol, 2-methylphenethyl alcohol, 3-methylphenethyl alcohol, 4-methylphenethyl alcohol, 2-methoxybenzyl alcohol, 3-iodobenzyl alcohol, cinnamic alcohol, p-anisyl alcohol, benzhydrol, benzyl alcohol, propylene glycol phenyl ether, ethylene glycol phenyl ether, and N-methylformanilide.

[0058] When dyeing a woven or knitted fabric containing meta-aramid fibers and para-aramid fibers, it is preferable to perform dyeing by raising the temperature to a temperature sufficient to dye the meta-aramid fibers and the para-aramid fibers with a cationic dye, which is a dyeing solution for aramid fibers. The cationic dye is preferably dyed at 115 to 135°C.

[0059] The concentration of the cationic dye during dyeing is preferably 20% owf or less (more preferably 0.01 to 15% owf, and even more preferably 0.1 to 10% owf). It is also preferable that the color difference (ΔE) between the flame-retardant recycled fiber and the unused flame-retardant fiber (preferably easily dyeable meta-aramid fiber) is 3 or less (more preferably 0.1 to 3).

[0060] The woven or knitted fabric may be additionally treated with various other treatments to impart functions such as water repellency, heat storage, ultraviolet shielding or antistatic, antibacterial, deodorant, insect repellent, luminous agent, and retroreflective agent. For example, the sweat absorbing agent is preferably polyethylene glycol diacrylate, a derivative of polyethylene glycol diacrylate, a polyethylene terephthalate-polyethylene glycol copolymer, or a water-soluble polyurethane. In particular, polyethylene glycol-amino silicone copolymer is preferred because it has good affinity with wholly aromatic polyamide fibers and is likely to provide sweat absorption that is durable to washing. In addition, the particle size of the sweat absorbing agent is preferably smaller because it is more easily fixed to wholly aromatic polyamide fibers, and is preferably in the range of 25 to 200 nm. The sweat absorbing agent may be applied by a same-bath treatment during dyeing, or by a padding treatment.

[0061] The above-mentioned method can provide the flame-retardant recycled woven or knitted fabric of the present invention, which has excellent heat resistance, flame resistance, and appearance quality. Since the woven or knitted fabric contains flame-retardant fibers, it can be used in a variety of applications that take advantage of the properties of the fibers.

[0062] The textile products of the present invention are made using the above-mentioned woven or knitted fabric, and include protective clothing, fire-retardant clothing for firefighters, clothing for firefighting activities, rescue clothing, workwear, police uniforms, clothing for the Self-Defense Forces, military uniforms, etc. Since the above-mentioned woven or knitted fabric is used, the textile products have excellent heat resistance, flame retardancy, flame resistance, and strength, and further have excellent color uniformity, and therefore have the properties of aramid fibers and are woven or knitted fabrics with excellent aesthetics, and are suitable for wearing by people who are engaged in work that may be exposed to flames, such as firefighters, pilots, race drivers, and workers at electric power or chemical companies. EXAMPLES

[0063] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The measurement items in the examples were measured by the following methods. 1 inch is 2.54 cm.

[0064] (1) Twist coefficient The twist factor was calculated as K=T / √n, where K is the twist factor, T is the number of twists per inch (2.54 cm), and n is the English cotton count.

[0065] (2) Fabric packing density The fabric packing density was calculated using the following formula: T = (ta1 + ta2) / (tm1 + tm2) Here, T is the filling rate of the fabric, ta1 is the amount of yarns actually occupied in one complete weave in the warp direction, and is the warp density per cm (threads / cm). Similarly, ta2 is the amount of yarns actually occupied in one complete weave in the weft direction, and is the weft density per cm (threads / cm). tm1 is the amount of the theoretically largest yarn in one complete weave in the warp direction, and tm2 is the amount of the theoretically largest yarn in one complete weave in the weft direction. tm was calculated using the following formula. tm=e / ((ei)×3.14×d / 4+2id) Here, e is the number of warp (or weft) yarns in one complete weave, i is the number of warp (or weft) crossings in one complete weave, and d is the diameter of the yarn, calculated by the following formula: d(cm)=0.00357×√((tex / (φ×ρf)) Here, tex is the value obtained by converting the spun yarn count into tex, φ is the yarn packing ratio, and ρf is the specific gravity of the fiber. For simplicity, the yarn packing ratio φ was calculated as 1.

[0066] (3) Fiber length distribution The distribution of fiber length was measured by measuring the staple diagram according to JIS L 1015:2010 8.4.1 Method A. The ratio of fiber lengths of 20 mm or more in the examples was calculated from the obtained staple diagram as described in the examples of Japanese Patent No. 3782061.

[0067] (4) Flame retardancy of fibers The limiting oxygen index (LOI) as defined in JIS 1091:1999 E-2 was measured.

[0068] (5) Opening degree of recycled fibers The degree of opening of the recycled fibers was calculated using the following formula. Opening rate (%) = (Wt-W) / Wt x 100 Here, W is the weight (g) of unopened fibers remaining in the recycled fiber in the form of threads, etc., and Wt is the total weight (g) of the recycled fiber. This allows us to express the percentage (%) of opened fibers in the recycled fiber.

[0069] (6) Crystallinity Using an X-ray diffraction measuring device (Rigaku RINT TTRIII), the fibers were aligned into a fiber bundle with a diameter of about 1 mm and attached to a fiber sample stage to measure the diffraction profile. The measurement conditions were Cu-Kα radiation source (50 kV, 300 mA), scanning angle range 10 to 35°, continuous measurement 0.1° width measurement, and 1° / min scanning. The total scattering profile was obtained by correcting the air scattering and incoherent scattering from the measured diffraction profile using linear approximation. Next, the amorphous scattering profile was subtracted from the total scattering profile to obtain the crystalline scattering profile. The degree of crystallinity was calculated from the area intensity of the crystalline scattering profile (crystalline scattering intensity) and the area intensity of the total scattering profile (total scattering intensity) using the following formula. Crystallinity (%) = [crystal scattering intensity / total scattering intensity] × 100

[0070] (7) Color difference (ΔE) The color of ΔE was measured using a Macbeth spectrophotometer Color-Eye 3100. If ΔE was 3 or less, it was judged as ◯ (pass), and if it was more than 3, it was judged as × (fail).

[0071] (8) Appearance of the fabric Fabric defects (neps, slub) and color irregularities were evaluated on a four-level scale from best to worst: ◎, ◯, △, ×.

[0072] [Example 1] As a flame-retardant spun yarn product to be recycled, a flame-retardant workwear fabric consisting of 95% by weight of meta-aramid fiber and 5% by weight of para-aramid fiber was used. The fabric was made of flame-retardant spun yarn 40 count / two-ply yarn consisting of 95% by weight of polymetaphenylene isophthalamide fiber (Teijin Conex (trademark) manufactured by Teijin Limited) and 5% by weight of coparaphenylene-3,4'-oxydiphenylene terephthalamide fiber (Technora (trademark) manufactured by Teijin Limited), with a final twist of 19.8 turns / inch (S twist). The fabric structure was twill (2 / 2), with a warp density of 86 threads / inch and a weft density of 75 threads / inch. The parameters required for the filling degree were e=4, i=2, and d=0.0165. The twist factor of this fabric was 4.43, the fill factor of the fabric was 0.73, and the twist factor x fill factor of the fabric was 3.23.

[0073] The fabric was cut into approximately 8 cm squares, washed and dried, and treated with an antistatic oil. The cut flame-retardant fabric was then crushed (bitten, torn, and torn off) using a pre-opening machine, and then opened (scraped and scraped off) using a de-piling machine. The degree of opening of the obtained flame-retardant recycled fiber (including thread-like material that was not fully opened) was 90%, and the openability of the flame-retardant recycled fiber was good.

[0074] This flame-retardant recycled fiber was mixed at 20% by weight of the entire spun yarn with 74.4% by weight of unused meta-aramid fiber (Teijin Conex Neo (trade name) manufactured by Teijin Limited) having a single fiber fineness of 1.7 dtex, fiber length of 51 mm, residual solvent content of 0.05% by weight, and crystallinity of 19%, unused para-aramid fiber (Teijin Aramid Co., Ltd.'s "Twaron" (trade name)), 4.0% by weight, and unused conductive fiber (Mitsubishi Chemical Corporation's "Corebrid" (trade name)), 1.6% by weight. The mixture was subjected to carding, drawing, roving, and fine spinning processes, and a base twist of 22.1 turns / inch in the Z direction was given to produce a flame-retardant spun yarn with a count of 40 / single yarn (British cotton count). The fibers were then subjected to a doubling process and a twisting process, with a final twist of 19.9 turns / inch in the S direction to produce a flame-retardant recycled spun yarn of 40 count / two-ply yarn (British cotton count). Tables 1 to 3 show the openability of the resulting recycled fibers, the ratio of fibers with a fiber length of 20 mm or more, and whether or not they can be processed into spun yarn.

[0075] Then, a plain weave fabric with a warp density of 57 threads / inch and a weft density of 53 threads / inch was woven. The fabric was singed, scoured, dried and heat treated to obtain an undyed fabric. Next, the color of the flame-retardant recycled fiber was measured in advance, and unused meta-aramid fiber was beaker-dyed so that the color difference was 3 or less, and the cationic dye and dye concentration to be used were determined. The obtained undyed woven fabric was dyed for 60 minutes at 130°C, which was heated from room temperature, in a dye bath containing the previously determined cationic dye (Kayacryl (trade name) manufactured by Nippon Kayaku Co., Ltd.). The above dyeing was performed by putting the woven fabric into the above dye bath, setting it in a liquid jet dyeing machine (High Temperature Circular manufactured by Hisaka Works, Ltd.), and stirring it under the above temperature conditions.

[0076] Next, 1 g / L of hydrosulfite, 1 g / L of soda ash, and a surfactant (1 g / L of Amylazine D manufactured by Meisei Chemical Co., Ltd.) were dissolved in water to prepare a post-treatment bath for reduction washing. The dyed fabric was put into this post-treatment bath, set in the above-mentioned liquid flow dyeing machine, and the temperature was raised from room temperature to 80°C at a heating rate of 2°C / min while stirring, and further held at 80°C for 20 minutes to perform reduction washing. After cooling, the dyed fabric was removed, washed with water, air-dried, and heat-treated for finishing. The heat treatment was performed at a temperature of 190°C for 2 minutes to obtain a dyed flame-retardant recycled fabric. The results are shown in Table 4.

[0077] [Reference example] For reference, unused meta-aramid fiber (Teijin Conex Neo (trade name) manufactured by Teijin Limited) with a single fiber fineness of 1.7 dtex and a fiber length of 51 mm was used at 93% by weight, para-aramid fiber (Teijin Aramid Co., Ltd., Twaron (trade name)), 5.0% by weight, and conductive fiber (Mitsubishi Chemical Corporation, Corebrid (product name)), at 2.0% by weight, and spinning, weaving, and dyeing were carried out in the same manner.

[0078] [Example 2] The flame-retardant recycled fiber described in Example 1 was mixed at 40% by weight, with 55.8% by weight of unused meta-aramid fiber (Teijin Conex Neo (trade name) manufactured by Teijin Limited) having a single fiber fineness of 1.7 dtex, fiber length of 51 mm, residual solvent content of 0.05% by weight, and crystallinity of 19%, unused para-aramid fiber (Teijin Aramid Co., Ltd., trade name, Twaron) at 3.0% by weight, and unused conductive fiber (Mitsubishi Chemical Corporation, trade name, Corebrid) at 1.2% by weight. The mixture was subjected to carding, drawing, roving, and fine spinning processes, and a first twist of 22.1 turns / inch in the Z direction was given to produce a flame-retardant spun yarn with a count of 40 / single yarn (British cotton count). The yarn was then subjected to a doubling process and a twisting process, giving the yarn a second twist of 19.9 turns / inch in the S direction, to produce a flame-retardant recycled spun yarn of 40 count / two-ply yarn (British cotton count). The obtained flame-retardant recycled spun yarn was used to obtain a dyed flame-retardant recycled woven fabric by weaving and dyeing in the same manner as in Example 1. The results are shown in Tables 1 to 4.

[0079] [Example 3] The flame-retardant fabric used for recycling was a flame-retardant workwear fabric made of 95% by weight of meta-aramid fiber and 5% by weight of para-aramid fiber. The fabric was made of flame-retardant spun yarn 36 count / two-ply yarn made of 95% by weight of polymetaphenylene isophthalamide fiber (Teijin Conex (trademark) manufactured by Teijin Limited) and 5% by weight of coparaphenylene-3,4'-oxydiphenylene terephthalamide fiber (Technora (trademark) manufactured by Teijin Limited), with a final twist of 19.8 turns / inch (S twist). The fabric structure was plain weave, with a warp density of 60 threads / inch and a weft density of 49 threads / inch. The parameters required for the filling were e=2, i=2, and d=0.0174. The twist coefficient of the two-ply yarn of this fabric was 4.66, the filling degree of the fabric was 0.75, and the twist coefficient x filling degree of the fabric was 3.48. The fabric was treated in the same manner as in Example 1. The opening degree of the obtained flame-retardant recycled fiber (including insufficiently opened filaments) was 85%, and compared to the flame-retardant recycled fiber of Example 1, although some unopened fibers of the yarn remained, the opening degree was generally good.

[0080] A flame-retardant recycled spun yarn of the present invention, 40 count / two-ply yarn (British cotton count), was produced using flame-retardant recycled fibers and virgin fibers in the same manner as in Example 1. The obtained flame-retardant recycled spun yarn was used to carry out weaving and dyeing in the same manner as in Example 1 to obtain a dyed flame-retardant recycled woven fabric. The results are shown in Tables 1 to 4.

[0081] [Example 4] The flame-retardant fabric used for recycling was a flame-retardant workwear fabric made of 95% by weight of meta-aramid fiber and 5% by weight of para-aramid fiber. The fabric was made of flame-retardant spun yarn 40 count / single yarn made of 95% by weight of polymetaphenylene isophthalamide fiber (Teijin Conex (trademark) manufactured by Teijin Limited) and 5% by weight of coparaphenylene-3,4'-oxydiphenylene terephthalamide fiber (Technora (trademark) manufactured by Teijin Limited), and the number of twists was 24.0 turns / inch (Z twist). The fabric structure was plain weave, with a warp density of 53 threads / inch and a weft density of 53 threads / inch. The parameters required for the filling were e=2, i=2, and d=0.0117. The twist coefficient of the single yarn of this woven fabric was 3.79, the filling rate of the woven fabric was 0.49, and the twist coefficient x filling rate of the woven fabric was 1.85. The woven fabric was treated in the same manner as in Example 1. The opening rate of the obtained flame-retardant recycled fiber (including insufficiently opened filaments) was 75%, and compared to the flame-retardant recycled fiber of Example 1, some unopened fibers remained in the threads, resulting in inferior opening rate.

[0082] A flame-retardant spun yarn 40 count / two-ply yarn according to the present invention was produced using flame-retardant recycled fibers and virgin fibers in the same manner as in Example 1. The obtained flame-retardant recycled spun yarn was used to carry out weaving and dyeing in the same manner as in Example 1 to obtain a dyed flame-retardant recycled woven fabric. The results are shown in Tables 1 to 4.

[0083] [Comparative Example 1] The flame-retardant fabric used for recycling was a flame-retardant workwear fabric made of 95% by weight of meta-aramid fiber and 5% by weight of para-aramid fiber. The fabric was made of flame-retardant spun yarn 35 / ply yarn made of 95% by weight of polymetaphenylene isophthalamide fiber (Teijin Conex (trademark) manufactured by Teijin Limited) and 5% by weight of coparaphenylene-3,4'-oxydiphenylene terephthalamide fiber (Technora (trademark) manufactured by Teijin Limited), with a final twist of 23.6 turns / inch (S twist). The fabric structure was plain weave, with a warp density of 65 threads / inch and a weft density of 55 threads / inch. The parameters required for the filling were e=2, i=2, and d=0.0177. The twist coefficient of the two-ply yarn of this fabric was 5.63, the filling rate of the fabric was 0.84, and the product of twist coefficient and filling rate of the fabric was 4.70. The fabric was treated in the same manner as in Example 1, but there was almost no opening, and it was not possible to feed the fabric as recycled fiber into the spinning process.

[0084] [Comparative Example 2] The flame-retardant fabric used for recycling was a flame-retardant workwear fabric made of 95% by weight of meta-aramid fiber and 5% by weight of para-aramid fiber. The fabric was made of flame-retardant spun yarn 35 / ply yarn made of 95% by weight of polymetaphenylene isophthalamide fiber (Teijin Conex (trademark) manufactured by Teijin Limited) and 5% by weight of coparaphenylene-3,4'-oxydiphenylene terephthalamide fiber (Technora (trademark) manufactured by Teijin Limited), with a final twist of 25.8 turns / inch (S twist). The fabric structure was a twill weave (2 / 1), with a warp density of 95 threads / inch and a weft density of 54 threads / inch. The parameters required for the filling were e=3, i=2, and d=0.0177. The twist coefficient of the two-ply yarn of this fabric was 6.17, the filling rate of the fabric was 0.83, and the product of twist coefficient and filling rate of the fabric was 5.09. The fabric was treated in the same manner as in Example 1, but there was almost no opening, and it was not possible to feed the fabric as recycled fiber into the spinning process.

[0085] [Example 5] The flame-retardant recycled fiber described in Example 1 was mixed at 5% by weight of the entire spun yarn, with 88.4% by weight of unused meta-aramid fiber (Teijin Conex Neo (trade name) manufactured by Teijin Limited) having a single fiber fineness of 1.7 dtex, fiber length of 51 mm, residual solvent content of 0.05% by weight, and crystallinity of 19%, and with 4.8% by weight of unused para-aramid fiber (Teijin Aramid Co., Ltd.'s "Twaron" (trade name)), and 1.9% by weight of unused conductive fiber (Mitsubishi Chemical Corporation's "Corebrid" (trade name)). The mixture was subjected to carding, drawing, roving, and fine spinning processes, and a first twist of 22.1 turns / inch in the Z direction was given to produce a flame-retardant spun yarn with a count of 40 / single yarn (British cotton count). The yarn was then subjected to a doubling process and a twisting process, giving the yarn a second twist of 19.9 turns / inch in the S direction, to produce a flame-retardant recycled spun yarn of 40 count / two-ply yarn (British cotton count). The obtained flame-retardant recycled spun yarn was used to obtain a dyed flame-retardant recycled woven fabric by weaving and dyeing in the same manner as in Example 1. The results are shown in Tables 1 to 4.

[0086] [Example 6] The flame-retardant recycled fiber described in Example 1 was mixed at 60% by weight of the entire spun yarn, with 37.2% by weight of unused meta-aramid fiber (Teijin Conex Neo (trade name) manufactured by Teijin Limited) having a single fiber fineness of 1.7 dtex, fiber length of 51 mm, residual solvent content of 0.05% by weight, and crystallinity of 19%, unused para-aramid fiber (Teijin Aramid Co., Ltd.'s "Twaron" (trade name)), 2.0% by weight, and unused conductive fiber (Mitsubishi Chemical Corporation's "Corebrid" (trade name)), 0.8% by weight. The mixture was subjected to carding, drawing, roving, and fine spinning processes, and a first twist of 22.1 turns / inch in the Z direction was given to produce a flame-retardant spun yarn with a count of 40 / single yarn (British cotton count). The yarn was then subjected to a doubling process and a twisting process, giving the yarn a second twist of 19.9 turns / inch in the S direction, to produce a flame-retardant recycled spun yarn of 40 count / two-ply yarn (British cotton count). The obtained flame-retardant recycled spun yarn was used to obtain a dyed flame-retardant recycled woven fabric by weaving and dyeing in the same manner as in Example 1. The results are shown in Tables 1 to 4.

[0087] [Example 7] The flame-retardant recycled fiber described in Example 1 was mixed at 20% by weight of the entire spun yarn, with 74.4% by weight of unused meta-aramid fiber (Teijin Conex (trade name) manufactured by Teijin Limited) having a single fiber fineness of 1.7 dtex, fiber length of 51 mm, residual solvent content of 0.05% by weight, and crystallinity of 65%, and with 4.0% by weight of unused para-aramid fiber (Teijin Aramid Co., Ltd.'s "Twaron" (trade name)), and with 1.6% by weight of unused conductive fiber (Mitsubishi Chemical Corporation's "Corebrid" (trade name)). The mixture was subjected to carding, drawing, roving, and fine spinning processes, and a first twist of 22.1 turns / inch in the Z direction was given to produce a flame-retardant spun yarn with a count of 40 / single yarn (British cotton count). The yarn was then subjected to a doubling process and a twisting process, and a second twist of 19.9 turns / inch was imparted in the S direction to produce a flame-retardant recycled spun yarn of 40 count / two-ply yarn (British cotton count). The obtained flame-retardant recycled spun yarn was used for weaving in the same manner as in Example 1.

[0088] The color of the flame-retardant recycled fiber was measured in advance, and unused meta-aramid fiber was beaker-dyed so that the color difference would be 3 or less. However, the meta-aramid fiber had a high crystallinity and was not dyed, so it was not possible to find dyeing conditions under which the color difference would be 3 or less. Dyeing was carried out, and a dyed flame-retardant recycled fabric was obtained. The results are shown in Tables 1 to 4.

[0089] [Table 1]

[0090] [Table 2]

[0091] [Table 3]

[0092] [Table 4] [Industrial Applicability]

[0093] According to the present invention, there are provided flame-retardant recycled woven and knitted fabrics and textile products which are made using flame-retardant recycled fibers and unused flame-retardant fibers and have flame-retardant performance and excellent appearance quality suitable for protective clothing applications, and which have extremely great industrial value.

Claims

1. A flame-retardant recycled woven or knitted fabric, comprising flame-retardant recycled fibers and unused flame-retardant fibers, and dyed with a cationic dye.

2. The flame-retardant recycled woven / knitted fabric comprises a flame-retardant recycled fiber obtained by opening a woven fabric or a textile product using said woven fabric, which is made using spun yarn and satisfies the following formula (I), and an unused flame-retardant fiber, and is characterized in that the flame-retardant recycled woven / knitted fabric is dyed with a cationic dye. Twist coefficient x fabric packing density ≦ 4.5 (I)

3. 3. The flame-retardant recycled woven or knitted fabric according to claim 2, wherein the spun yarn contains flame-retardant fibers having a limit oxygen index of 25 or more as measured by JIS L1091 E method in an amount of 40% by weight or more based on the weight of the spun yarn.

4. 2. The flame-retardant recycled woven or knitted fabric according to claim 1, which is a woven or knitted fabric using spun yarn, in which the flame-retardant recycled fiber is blended in an amount of 10 to 50% by weight relative to the weight of the spun yarn.

5. 2. The flame-retardant recycled woven or knitted fabric according to claim 1, wherein the flame-retardant recycled woven or knitted fabric is a woven or knitted fabric using spun yarn, and the spun yarn contains 50 to 90% by weight of virgin flame-retardant fiber having a fiber length of 30 to 200 mm and a limit oxygen index of 25 or more as measured by JIS L1091 E method, based on the weight of the spun yarn.

6. 2. The flame-retardant recycled woven or knitted fabric according to claim 1, wherein the flame-retardant recycled fibers and / or unused flame-retardant fibers are one or more fibers selected from the group consisting of meta-aramid fibers, para-aramid fibers, polyparaphenylene benzoxazole fibers, polybenzimidazole fibers, polybenzimidazole fibers, polyimide fibers, polyetherimide fibers, polyamideimide fibers, carbon fibers, polyphenylene sulfide fibers, polyvinyl chloride fibers, flame-retardant rayon, modacrylic fibers, flame-retardant acrylic fibers, flame-retardant polyester fibers, flame-retardant vinylon fibers, melamine fibers, fluorine fibers, flame-retardant wool, and flame-retardant cotton.

7. 2. The flame-retardant recycled woven or knitted fabric according to claim 1, wherein the flame-retardant recycled woven or knitted fabric is a woven or knitted fabric using spun yarn, and the unused flame-retardant fiber is a meta-aramid fiber, and the meta-aramid fiber is contained in an amount of 50 to 90% by weight of the entire spun yarn.

8. 2. The flame-retardant recycled woven or knitted fabric according to claim 1, wherein the unused flame-retardant fiber is a meta-aramid fiber having a residual solvent content of 0.1% by weight or less and a crystallinity of 5 to 35%.

9. The flame-retardant recycled woven or knitted fabric according to claim 1, which is a woven or knitted fabric using spun yarn, the spun yarn containing conductive fibers.

10. 2. The flame-retardant recycled woven or knitted fabric according to claim 1, wherein the virgin flame-retardant fiber is a meta-aramid fiber, and a color difference between the flame-retardant recycled fiber and the meta-aramid fiber is 3 or less.

11. A textile product comprising the flame-retardant recycled woven or knitted fabric according to any one of claims 1 to 10.

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