Heat insulating material, fiber product, and product with storage bag

Abstract

The present invention addresses the problem of providing a heat insulating material, a fiber product, and a product with a storage bag, which are bulky and excellent in heat insulating properties, are excellent in handleability such as compressibility and compression recoverability, softness, difficulty in getting stuffy, and degree of freedom of design, and are easily recycled after being made into a fiber product.　A heat insulating material according to the present invention is composed of fibers containing 95 mass% or more of aliphatic polyamide staple fibers, and satisfies the following (1) to (3). (1) An aliphatic polyamide hollow staple fiber A as a 3-10 dtex single component and having a crimp structure with a structural difference crimp is included at least in part. (2) One or more kinds of stable fibers different from the aliphatic polyamide hollow staple fiber A are included, the ratio of the fineness of the aliphatic polyamide hollow stable fiber A to the fineness of a staple fiber B having the lowest fineness among those is 1.5 or greater, and the number of crimps of the stable fiber B is different from the number of crimps of the aliphatic polyamide hollow stable fiber A. (3) The compression ratio is 45% or greater.

Description

Heat insulation materials, textile products and products with storage bags

[0001] The present invention relates to a heat insulating material, a textile product, and a product with a storage bag.

[0002] Common insulation materials are down, feathers, natural fibers, and synthetic fibers, and are used either as they are in the cover or in sheets, granules, or shredded cotton form.

[0003] Patent Document 1 discloses a bulky and durable wadding made by integrating a plurality of loop-shaped fibers with a core thread, and a method for producing the same.

[0004] Patent Document 2 discloses a padding method using void fibers that are blended with two incompatible components and have voids inside the fibers to provide padding that is compression recoverable, resistant to settling, and lightweight.

[0005] Furthermore, Patent Document 3 describes clothing that uses nanoporous polyamide fibers in at least a portion thereof to improve heat retention and lightness, and suggests that it would be effective to use nanoporous polyamide fibers in the padding portion where a lightweight feel is required.

[0006] JP 2009-52183 A JP 2006-345920 A JP 2005-15961 A

[0007] Down and feather insulation are known for their lightweight, lofty, and excellent heat retention properties. However, obtaining them requires the raising of large numbers of waterfowl, which can lead to problems such as water pollution caused by waterfowl excrement and the spread of infectious diseases. Furthermore, using down and feathers as stuffing requires numerous processes, including collection, sorting, disinfection, and degreasing, which consume a lot of energy and water. In terms of work, feathers tend to become airborne, so the process of filling the lining must be carried out in an enclosed space, limiting the work environment. Furthermore, workers may inhale the airborne feathers, necessitating measures such as wearing masks. Down is composed of a collection of down balls, not a single unit, making it difficult to handle. Its shape changes during use, reducing its heat retention. Furthermore, down easily absorbs moisture, and the down tends to tangle and become uneven during washing. Furthermore, the stiff barbs can pierce the inner lining and blow out, resulting in poor appearance and reduced heat retention. If the inner lining is made of a high-density fabric to prevent this, the texture becomes stiff and it tends to wrinkle easily after being compressed and stored. When recycling textile products, the nylon inner lining, zippers, materials, and feathers must all be sorted and separated, and then the nylon inner lining must be chemically recycled and the down must be re-washed for recycling, resulting in a complicated process.

[0008] Furthermore, among synthetic fiber batting, polyethylene terephthalate batting is the mainstream. While some of this batting is lightweight and bulky, its high rigidity makes it difficult to compress, making it difficult to store in a storage bag, resulting in problems such as inconvenient portability and requiring a lot of storage space. Furthermore, since polyethylene terephthalate batting is used for batting, if textile products are recycled primarily using polyethylene terephthalate, using polyethylene terephthalate for the outer fabric will provide excellent recyclability, but on the other hand, the product will have a stiff texture, be prone to becoming stuffy, and have poor water-repellent properties, which reduces the value of the textile product.

[0009] Furthermore, although nylon fiber was thought to have excellent compressibility, it was found to be less rigid than polyethylene terephthalate, with poor bulk and compression recovery, and to be significantly more likely to collapse after washing, making it essentially unsuitable for use as padding.

[0010] The technology specifically disclosed in Patent Document 1 uses nylon as one of the core yarns, which is composed of at least two types of yarn with different melting points, but since it is a filament, it does not have three-dimensional crimp and is insufficient in bulkiness and compressibility.In addition, the wadding is in the form of long fibers, which makes it difficult to fill with wadding during sewing, and the fact that it is a composite fiber makes it difficult to recycle.

[0011] The crimp form of the fibers in the void fibers specifically disclosed in Patent Document 2 is a buckling-type mechanical crimp. This crimp form has a two-dimensional structure, and the fibers tend to align in the same direction. Therefore, when using nylon 6, which has low rigidity, the bulkiness is insufficient, and the heat retention and resistance to settling relative to the weight are also insufficient.

[0012] Furthermore, the technology disclosed in Patent Document 3 has raw cotton physical properties suitable for spun yarn, and does not disclose the large, loose crimp required for padding applications, resulting in insufficient bulkiness, compressibility, and compression recovery.

[0013] To provide a heat insulating material, a textile product, and a product with a storage bag, which are bulky and excellent in heat retention, easy to handle such as compressibility and compression recovery, soft, not prone to getting stuffy, and have excellent freedom of design, and which can be easily recycled after being made into a textile product.

[0014] The present inventors have conducted extensive research to develop a material that is excellent in compressibility, compression recovery, and heat retention, and have discovered a heat-retaining material that uses aliphatic polyamide hollow short fibers that makes this possible, and which has the following composition.

[0015] [1] A thermal insulation material composed of fibers containing 95% by mass or more of aliphatic polyamide staple fibers and satisfying the following (1) to (3): (1) At least a portion of the material contains aliphatic polyamide hollow staple fibers A having a single component of 3 to 10 dtex and a structurally differentially crimped structure; (2) The material contains one or more types of staple fibers different from the aliphatic polyamide hollow staple fibers A, in which the ratio of the fineness of the aliphatic polyamide hollow staple fibers A to the finest staple fiber B among the fibers is 1.5 or more, and the number of crimps is also different from the number of crimps of the aliphatic polyamide hollow staple fibers A; (3) The compressibility is 45% or more.

[0016] [2] The heat insulating material according to [1], wherein the compression recovery rate of the heat insulating material is 50% or more.

[0017] [3] The heat-insulating material according to [1] or [2], wherein the single fiber fineness of the short fiber B is 0.3 to 3 dtex.

[0018] [4] In the fibers constituting the heat insulating material, the aliphatic polyamide hollow short fiber A is 30 to 97% by mass, the short fiber B is 3 to 70% by mass, and the other short fiber C is 0% by mass or more. [1] A heat insulating material according to any one of [1] to [3].

[0019] [5] The thermal insulation material according to any one of [1] to [4], wherein the mixing ratio of short fibers having a structurally different crimped structure among the fibers constituting the thermal insulation material is 55% by mass or more.

[0020] [6] The heat insulating material according to any one of [1] to [5], wherein the hollow ratio of the aliphatic polyamide hollow short fiber A is 5% to 60%.

[0021] [7] The heat insulating material according to any one of [1] to [6], wherein the heat insulating material contains 95% by mass or more of polycaproamide.

[0022] [8] The heat insulating material according to any one of [1] to [7], wherein the diameter of the storage bag per 1 g of the heat insulating material is 0.8 cm or less.

[0023] [9] A textile product at least partially comprising a stuffing material in which the heat-insulating material according to any one of [1] to [8] is filled into a side fabric.

[0024]

[10] The textile product according to [9], containing 95% by mass or more of polycaproamide.

[0025]

[11] The textile product according to [9] or

[10] , wherein the textile product is clothing.

[0026]

[12] A product with a storage bag, comprising the textile product according to any one of [8] to

[11] and a storage bag that can store and remove the textile product.

[0027] The heat insulating material of the present invention makes it possible to obtain a heat insulating material, a textile product, and a product with a storage bag that are bulky and have excellent heat retention, are easy to handle such as compressibility and compression recovery, are soft, do not get stuffy, and have excellent design freedom, and are easy to recycle after being made into a textile product.

[0028] The compressibility of the fabric is excellent in that it can be easily compressed even with a small load. Furthermore, the use of polyamide staple fibers can significantly improve the recyclability of products using polyamide for the lining. Furthermore, while conventional nylon padding has low bulk and compression recovery, making it difficult to use it as a solid winter garment, the fabric of the present invention can be used for both thin and thick winter garments, offering excellent design freedom.

[0029] For these reasons, the material can be suitably used as a thermal insulator for clothing such as jackets and pants, for clothing accessories such as gloves, scarves and hats, for bedding such as sleeping bags, futons, beds and pillows, and for vehicles such as automobiles, trains and airplanes.

[0030] Figure 1 is a photograph of staple fibers laid flat on a black backing without any load applied, and Figure 2 is a schematic diagram for explaining the measurement of the crimp height h and the crimp base width w.

[0031] The thermal insulation material of the present invention is composed of fibers containing 95% by mass or more of aliphatic polyamide staple fibers and satisfies the following (1) to (3): (1) At least a portion of the thermal insulation material contains aliphatic polyamide hollow staple fibers A having a single component of 3 to 10 dtex and a structurally differentially crimped structure; (2) The thermal insulation material contains one or more types of staple fibers different from the aliphatic polyamide hollow staple fibers A, in which the ratio of the fineness of the aliphatic polyamide hollow staple fibers A to the finest staple fiber B among the fibers is 1.5 or more, and the number of crimps is also different from the number of crimps of the aliphatic polyamide hollow staple fibers A; and (3) The compressibility is 45% or more.

[0032] The present invention will be described in detail below.

[0033] The thermal insulation material of the present invention is composed of fibers containing 95% by mass or more of aliphatic polyamide short fibers, and may be in the form of a normal nonwoven fabric. From the viewpoints of compressibility, resistance to stuffiness, and chemical recycling, the aliphatic polyamide short fibers preferably account for 98% by mass or more of the fibers constituting the thermal insulation material. The upper limit is preferably 100% by mass.

[0034] Examples of aliphatic polyamides include polycaproamide (nylon-6), poly-ω-aminoheptanoic acid (nylon-7), polyundecanamide (nylon-11), polyethylene diamine adipamide (nylon-2,6), polycyclobutane adipamide (nylon-4,6), polypentamethylene adipamide (nylon-5,6), polyhexamethylene adipamide (nylon-6,6), polyhexamethylene sebacamide (nylon-2,10), polyhexamethylene dodecamide (nylon-6,12), polyoctamethylene adipamide (nylon-8,6), polydecamethylene adipamide (nylon-10,6), and copolymers thereof. Examples of polyamide copolymers include caprolactam / laurinlactam copolymer (nylon-6 / 12) (" / " indicates copolymerization, the same applies below), caprolactam / ω-aminononanoic acid copolymer (nylon-6 / 9), caprolactam / hexamethylene adipamide copolymer (nylon-6 / 6,6), laurinlactam / hexamethylenediamine adipamide copolymer (nylon-12 / 6,6), Examples of usable polymers include hexamethylenediamine adipamide / hexamethylenediamine adipamide copolymer (nylon-6,6 / 6,10), ethylenediamine adipamide / hexamethylenediamine adipamide copolymer (nylon-2,6 / 6,6), and caprolactam / hexamethylenediamine adipamide / hexamethylenediamine sebacic acid copolymer (nylon-6,6 / 6,10). Blends of the above polymers can also be used. Among these, nylon 6 is preferred because of its compressibility, moderate softness, resistance to stuffiness, and ease of recycling, and it is particularly preferred to contain 98% or more nylon 6 by mass.

[0035] The aliphatic polyamide short fibers may contain various additives depending on the purpose, such as matting agents such as titanium oxide, silica, cesium tungsten oxide, and calcium carbonate, antibacterial agents, antiviral agents, water repellents, flame retardants, antistatic agents, antioxidants, ultraviolet absorbers, pigments for base adhesive, and heat-shielding agents.

[0036] The fiber form of the aliphatic polyamide staple fiber is not particularly limited and may include fibers consisting of only a single component, so-called single yarns, spun using one resin component, as well as composite fibers such as core-sheath composite fibers and sea-island structure fibers, but it is necessary that at least a portion of the fiber contains aliphatic polyamide hollow staple fibers A having a single component with a structurally different crimped structure. The single yarn referred to here means a yarn whose entire constituent components are uniform, and the constituent component may be a single polymer, a composition obtained by mixing two or more polymers, such as an alloy, by a method such as melt-kneading, or a composition to which particles, additives, etc. are added by a method such as melt-kneading.

[0037] [Aliphatic Polyamide Hollow Staple Fiber A] The aliphatic polyamide hollow staple fiber A is a single component fiber having a structurally different crimp structure. Here, "single component" means the so-called single yarn.

[0038] Furthermore, the term "structurally different crimp structure" refers to a crimp that occurs due to differences in heat shrinkability caused by structural differences that occur when a single yarn undergoes uneven temperature history, such as asymmetric cooling in which cooling is performed from one side during spinning. This typically refers to a three-dimensional or three-dimensional crimp structure, specifically an arc-shaped crimp, such as an Ω-shaped arc, with a large, loose crimp structure and a three-dimensional crimp structure with floating portions when the staple fiber is placed on a flat surface (hereinafter sometimes referred to as "three-dimensional crimp"). This is distinct from crimp structures resulting from mechanical crimping, such as two-dimensional zigzag (peaks and valleys) crimps produced by a crimper using a stuffer box or the like, or so-called buckling crimps. It is also distinct from the fine crimps that occur when side-by-side or eccentric core-sheath composite fibers are used.

[0039] In the present invention, the radius ratio Rr, defined below as an index showing the degree of crimp curvature, is preferably 2.0 to 10.0, more preferably 3.0 to 7.0.

[0040] That is, when one crimp wave (a curve between adjacent inflection points sandwiching one crimp peak) formed by the crimp of staple fibers is considered, the curve of this wave is regarded as an arc, and the straight line connecting the adjacent inflection points sandwiching the crimp peak is regarded as a chord, and the radius of the arc is calculated from this arc and the chord, and the radius is divided by the height of the crimp peak to obtain the radius ratio. The measurement method is as follows.

[0041] A single short fiber to be measured, collected without damaging the crimp, was placed on a horizontal black mount without any load and photographed from above with a microscope at 20x magnification. Three crimp peaks were identified near the center of the fiber, and the crimp peak height (h) and crimp peak base width (w) were measured. The h and w values ​​obtained for each crimp peak were applied to the following formulas (1) and (2), and the average was calculated. This was measured for 20 fibers, and the average was calculated. Figure 1 shows a photograph of the short fiber laid on a black mount without any load, and Figure 2 is a schematic diagram illustrating the measurement of the crimp peak height (h) and crimp peak base width (w). The length of the line connecting the adjacent inflection points across the crimp peak was defined as the crimp peak base width (w), and the length of the line drawn from the crimp peak at a right angle to the line was defined as the crimp peak height (h). Arc radius R = ((w / 2) ２ +h ２ ) / (2 × h) (1) Radius ratio Rr = R / h (2) h: height of crimped peak w: width of base of crimped peak Based on the above calculation results, the radius ratio Rr, which is the ratio of the arc radius R to h, was calculated.

[0042] In the aliphatic polyamide hollow short fibers A, the radius ratio Rr can be controlled to a preferred value by asymmetrically cooling the aliphatic polyamide hollow fibers during spinning to develop structurally different crimps.

[0043] The cross section of the fiber perpendicular to the longitudinal direction (hereinafter referred to as the fiber cross section) has a hollow cross section, and the outer shape of the hollow cross section may be a circular cross section or an irregular cross section. The irregular cross section may be a polygonal cross section such as a triangular cross section or a rectangular cross section, a flat cross section, a cross section, a hash mark cross section, a multi-lobed cross section such as an eight-lobed cross section, or any other shape. These fiber shapes and fiber cross sections can be appropriately selected depending on the purpose.

[0044] The hollow cross section can improve the bulkiness relative to the fiber weight. In particular, from the viewpoints of recovery after compression and appropriate softness, the hollow ratio is preferably 20 to 40%, more preferably 30 to 40%. The hollow ratio is a value measured by the method described below.

[0045] The single fiber fineness of the aliphatic polyamide hollow staple fiber A is 3 to 10 dtex, preferably 5 to 8 dtex. By being below the upper limit, the single yarn does not become too thick, resulting in an excellent texture, and the number of constituent fibers per unit mass is sufficient, resulting in excellent compressibility and heat retention. By being above the lower limit, an air layer can be maintained, reducing settling after washing and providing excellent compression recovery after storage. Furthermore, it is preferable that the fineness of the aliphatic polyamide hollow staple fiber A be 1.5 times or more the fineness of the short fiber B having the finest fineness contained in the thermal insulation material, as this allows the thermal insulation material to be dense and suppresses air convection. Note that when multiple short fibers with different finenesses are used as the aliphatic polyamide hollow staple fiber A, the above fineness ratio refers to the ratio to the aliphatic polyamide hollow staple fiber A with the thickest fineness.

[0046] From the viewpoints of bulkiness and compression recovery, the aliphatic polyamide hollow staple fiber A preferably has a crimp number of 2 to 20 crimps per 25 mm, more preferably 2 to 15 crimps per 25 mm. By setting the crimp number to the above upper limit or less, the entanglement of the fibers is not too high, the generation of neps is suppressed in the carding process of nonwoven fabric production, and nonwoven fabrics with excellent bulkiness can be easily produced. By setting the crimp number to the above lower limit or more, the entanglement of the fibers is not too low, and excellent web uniformity is achieved. Furthermore, in the fiber balls described below, the entanglement in the ball-making process is excellent and the bulkiness is also excellent.

[0047] The aliphatic polyamide hollow short fibers A preferably have a crimp degree of 5 to 40%, more preferably 10 to 35%, from the viewpoints of bulkiness and compression recovery.

[0048] The fiber length of the aliphatic polyamide hollow short fibers A is 20 mm to 70 mm, and preferably 25 mm to 38 mm. By being equal to or greater than the lower limit, sufficient entanglement is achieved during the fiber ball forming process and chemical bond web process described below, facilitating production. Furthermore, when the fibers are inserted into the outer fabric and used as a thermal insulation material, the fibers are sufficiently long and sufficiently entangled, preventing short fibers from blowing out and falling out of the outer fabric, resulting in excellent appearance and maintenance of the quality of the garment. By being equal to or less than the upper limit, the fiber length is appropriate, preventing excessive fiber alignment, and providing excellent bulkiness.

[0049] As the aliphatic polyamide hollow short fibers A, two or more types of short fibers different in one or more of fineness, number of crimps, degree of crimp, and fiber length may be used in combination.

[0050] The mixing ratio of the aliphatic polyamide hollow short fibers A in the fiber components constituting the thermal insulation material is preferably 30% by mass or more, more preferably 45% by mass or more, in terms of excellent compression recovery and bulkiness, and is preferably 97% by mass or less in terms of excellent softness.

[0051] [One or more types of staple fibers different from aliphatic polyamide hollow staple fibers A] The heat-insulating material of the present invention contains one or more types of staple fibers different from the aliphatic polyamide hollow staple fibers A, and the ratio of the fineness of the aliphatic polyamide hollow staple fibers A to the finest staple fibers B (hereinafter referred to as staple fibers B) is 1.5 or more, and the number of crimps is also different from the number of crimps of the aliphatic polyamide hollow staple fibers A.

[0052] As described above, by including the short fibers B having a different fineness and number of crimps from the aliphatic polyamide hollow short fibers A, the phases of the fibers are less likely to be aligned, and portions where the fibers are not densely structured are less likely to occur, resulting in even better bulkiness, heat retention, and compression recovery.

[0053] Furthermore, the fineness ratio of aliphatic polyamide hollow staple fiber A to the fineness of staple fiber B being 1.5 or more means that the ratio (fineness A / fineness B) of the single fiber fineness of aliphatic polyamide hollow staple fiber A to the single fiber fineness (fineness B) of staple fiber B is 1.5 or more. When multiple types of aliphatic polyamide hollow staple fiber A are used, the fineness of the aliphatic polyamide hollow staple fiber A with the thickest fineness is used in the calculation. From the viewpoints of bulkiness, heat retention, and compression recovery, this fineness ratio is more preferably 1.7 or more. From the viewpoint of texture, the upper limit is preferably 30 or less, more preferably 8 or less.

[0054] The fineness of the short fibers B must satisfy the above-mentioned fineness ratio, and is preferably 0.3 dtex or more, more preferably 0.8 dtex or more, from the viewpoints of bulkiness and compression recovery, and is preferably 3 dtex or less, more preferably 2 dtex or less, from the viewpoint of texture.

[0055] The crimp number of the finest fiber B is preferably 2 to 20 crimps / 25 mm, more preferably 4 to 20 crimps / 25 mm, from the viewpoint of bulkiness. By setting the crimp number below the upper limit, the entanglement of the fibers is not too high, and the generation of neps is suppressed in the carding process of nonwoven fabric production. By setting the crimp number above the lower limit, the entanglement of the fibers is not too low, and excellent web uniformity is achieved. Furthermore, in the fiber balls described below, excellent entanglement is achieved in the ball-making process, and also excellent bulkiness is achieved. The crimp number of fiber B must be different from the crimp number of the aliphatic polyamide hollow staple fiber A. From the viewpoint of compression recovery, the ratio of the crimp number of the larger crimp fiber to the crimp number of the smaller crimp fiber between fiber B and aliphatic polyamide hollow staple fiber A is preferably 1.01 to 20.00, with the lower limit being more preferably 1.03 or more, even more preferably 1.20 or more, and particularly preferably 1.30 or more. The upper limit is more preferably 15.00 or less, even more preferably 10.00 or less, and particularly preferably 8.00 or less.

[0056] The crimp form of the staple fibers B preferably has a structurally different crimp. The radius ratio, which indicates the degree of crimp curvature, is 2.0 to 10.0, more preferably 3.0 to 7.0, from the viewpoints of bulkiness and recovery from compression. The radius ratio here is also a value measured by the method described above. As described above, the preferred crimp form is a structurally different crimp, but staple fibers B having the mechanically crimped or finely crimped form described above may also be included as long as the range specified in the present invention is satisfied.

[0057] The finest fiber B preferably has a crimp degree of 5 to 40%, more preferably 10 to 35%, from the viewpoints of bulkiness and compression recovery.

[0058] The fiber length of the short fibers B is preferably 20 mm to 70 mm, and particularly preferably 25 mm to 38 mm. By setting the length at or above the lower limit, sufficient entanglement is achieved during the fiber ball forming process and chemical bond web process described below, facilitating manufacturing. Furthermore, when inserted into the side fabric and used as a thermal insulation material, the fibers are sufficiently long and well entangled, preventing short fibers from blowing out and falling out of the side fabric, resulting in a garment with excellent appearance quality that can be maintained for a long period of time. Setting the length at or below the upper limit ensures an appropriate fiber length, preventing excessive fiber alignment and resulting in excellent bulkiness.

[0059] The short fibers B may be of one type, or of two or more types differing in material, number of crimps, degree of crimp, fiber length, etc.

[0060] The mixing ratio of the short fibers B in the fiber components constituting the thermal insulation material is preferably 3 to 70% by mass, more preferably 3 to 55% by mass, from the viewpoints of heat retention, bulkiness and compression recovery.

[0061] In the heat insulating material of the present invention, short fibers other than those mentioned above (hereinafter referred to as short fibers C) can also be used.

[0062] The number of crimps of the staple fibers C is preferably 2 to 20 crimps / 25 mm, more preferably 2 to 15 crimps / 25 mm, from the viewpoints of bulkiness and compression recovery. A crimp number below the upper limit prevents excessive fiber entanglement, suppressing the generation of neps during the carding process of nonwoven fabric production. A crimp number above the lower limit prevents excessive fiber entanglement, resulting in excellent web uniformity. Furthermore, in the fiber balls described below, sufficient entanglement during the ball-making process results in excellent bulkiness. Furthermore, the number of crimps of the staple fibers C is preferably different from the number of crimps of the aliphatic polyamide hollow staple fibers A used, and is also preferably different from the number of crimps of the staple fibers B, in order to prevent the fibers from becoming misaligned and to reduce the occurrence of areas where the fibers are not densely packed, thereby achieving even better bulkiness, heat retention, and compression recovery. In particular, from the viewpoint of compression recovery, the ratio of the number of crimps of the fiber with the larger number of crimps to the number of crimps of the fiber with the smaller number of crimps between fiber C and aliphatic polyamide hollow staple fiber A is preferably 1.01 to 20.00, with a lower limit of 1.03 or more being more preferred, 1.20 or more being even more preferred, and 1.30 or more being particularly preferred. The upper limit is more preferably 15.00 or less, more preferably 10.00 or less, and particularly preferably 8.00 or less. Furthermore, for any two combinations of fiber C, aliphatic polyamide hollow staple fiber A, and fiber B, the ratio of the number of crimps of the fiber with the larger number of crimps to the number of crimps of the fiber with the smaller number of crimps is preferably 1.01 to 20.00, with a lower limit of 1.03 or more being more preferred, 1.20 or more being even more preferred, and 1.30 or more being particularly preferred. The upper limit is more preferably 15.00 or less, even more preferably 10.00 or less, and particularly preferably 8.00 or less.

[0063] The degree of crimp of the short fibers C is preferably 5 to 40% by mass, more preferably 10 to 35% by mass, from the viewpoints of bulkiness and compression recovery.

[0064] The single fiber fineness of the staple fibers C is greater than that of the staple fibers B, but is preferably 0.3 to 8 dtex, and particularly preferably 1 to 6.6 dtex, within the upper limit. By keeping the single fiber fineness at or below the upper limit, the single yarn does not become too thick, resulting in an excellent texture and a sufficient number of constituent fibers per mass, thereby providing excellent compressibility and heat retention. Furthermore, the fineness of the staple fibers C is preferably different from that of the aliphatic polyamide hollow staple fibers A used, and more preferably smaller than that of the aliphatic polyamide hollow staple fibers A, since the fibers are less likely to have a dense structure.

[0065] The fiber length of the short fibers C is preferably 20 mm to 70 mm, and particularly preferably 25 mm to 51 mm. By setting the length at or above the lower limit, sufficient entanglement is achieved during the fiber ball forming process and chemical bond web process described below, facilitating manufacturing. Furthermore, when inserted into the side fabric and used as a thermal insulation material, the fibers are sufficiently long and highly entangled, preventing short fibers from blowing out and falling out of the side fabric, resulting in an excellent appearance and maintenance of the garment's quality. By setting the length at or below the upper limit, the fiber length is appropriate, preventing excessive fiber alignment and resulting in excellent bulkiness.

[0066] Similarly to the aliphatic polyamide hollow staple fibers A, the staple fibers C preferably have a structurally different crimped structure. The radius ratio of the arc of the raw cotton, which indicates the degree of crimp curvature, is 2.0 to 10.0, more preferably 3.0 to 7.0, from the viewpoints of bulkiness and recovery from compression. The radius ratio here is also a value measured by the method described above.

[0067] The short fibers C may be of one type, or of two or more types differing in material, fineness, number of crimps, degree of crimp, fiber length, etc.

[0068] The other short fibers C are optional components and may be 0% by mass, but when used in combination, the mixing ratio is the balance of the mixing ratios of the aliphatic polyamide hollow short fibers A and the short fibers B.

[0069] The mixing ratio of short fibers having a structurally different crimped structure (when aliphatic polyamide hollow short fiber A, short fiber B, and optional short fiber C are used, this is the total mixing ratio of short fibers having a structurally different crimped structure) is preferably 55% by mass or more and 100% by mass or less, and more preferably 70% by mass or more and 100% by mass or less, of the fiber components constituting the thermal insulation material.

[0070] As the staple fibers B and C, it is possible to use short fibers having mechanical crimps as described above, or short fibers having fine crimps such as side-by-side or eccentric core-sheath composite fibers, but if they are used in excess, bulkiness and compression recovery tend to decrease, so the amount is limited to a range that satisfies the compressibility specified in the present invention. Specifically, when the total amount of short fibers B and C having crimp structures other than such structurally different crimp structures is used, it is preferable from the viewpoint of bulkiness and compression recovery that it be 45% by mass or less of the fiber components constituting the thermal insulation material, and more preferably 30% by mass or less. The lower limit is 0% by mass or more.

[0071] Furthermore, the cross sections of staple fibers other than the aliphatic polyamide hollow staple fibers A may be round, hollow, or irregular cross sections. The irregular cross sections may be polygonal, such as triangular or rectangular, flat, cross, well (#) or multilobal, such as eight-lobed, hollow, or any other shape. These fiber shapes and cross sections can be appropriately selected depending on the purpose.

[0072] The content of short fibers other than aliphatic polyamide hollow staple fibers A is adjusted as follows. That is, as described above, the mixing ratio of aliphatic polyamide short fibers including aliphatic polyamide hollow staple fibers A is set to 95% by mass or more of the fiber components constituting the thermal insulation material, and preferably 98% by mass or more. The upper limit is preferably 100% by mass. Furthermore, short fibers other than aliphatic polyamide short fibers may be mixed in the fiber components constituting the thermal insulation material, as long as the amount is 5% by mass or less, provided that the range does not impair the gist of the invention. The amount is preferably 2% by mass or less. The lower limit is preferably 0% by mass.

[0073] Staple fiber materials other than aliphatic polyamide staple fibers include, but are not limited to, synthetic staple fibers such as polyethylene terephthalate staple fibers, aromatic polyamide staple fibers, polypropylene staple fibers, polyethylene staple fibers, and acrylic staple fibers, regenerated staple fibers such as rayon staple fibers, modal staple fibers, and acetate staple fibers, semi-synthetic staple fibers such as acetate, and natural fibers such as cotton and wool. From the viewpoint of bulkiness and compressibility, synthetic staple fibers such as polyethylene terephthalate staple fibers and polypropylene staple fibers are desirable, and from the viewpoint of heat retention, synthetic staple fibers such as acrylic and polyphenylene sulfide are desirable.

[0074] [Method for producing aliphatic polyamide staple fibers having structurally different crimped structures] Aliphatic polyamide staple fibers having structurally different crimped structures can usually be produced by melt-spinning, followed by spinning while forcibly cooling by blowing cold air from one direction. That is, by using asymmetric cooling, which imposes different cooling conditions on the side where the cold air is blown and the opposite side, a structural difference occurs in the fiber, resulting in a difference in heat shrinkability. The different heat shrinkability can be utilized to develop a crimped structure. More specifically, aliphatic polyamide staple fibers such as nylon 6 can usually be preferably produced by the following method.

[0075] When hollow short fibers are produced, a spinneret designed for producing hollow fibers may be used. (1) After spun from the spinneret, molten polyamide having a sulfuric acid relative viscosity of 2.5 to 2.8 is blown from one direction and forcedly cooled by cold air, which is taken up at 500 to 4,000 m / min to obtain an undrawn yarn, which is then drawn. The cooling conditions are preferably two-stage continuous cooling, with the initial cooling start distance being 10 to 40 mm, the cooling length being 30 to 60 mm, and the side air speed being 40 to 100 m / min. The air speed on the blowing side of the second cooling section is preferably 20 to 40 m / min. (2) In the drawing process, undrawn yarns are bundled to 50 to 500 ktex and drawn 2 to 5 times in steam or hot water, followed by heat treatment while relaxing, application of a finishing oil, and cutting to a predetermined fiber length to obtain polyamide staple fibers with three-dimensional crimp. Heat treatment with steam is preferred to improve settability. Mechanical crimping using a crimper used in the production of raw cotton for spinning, etc., tends to align the fiber phase in the fiber direction, making it difficult to achieve bulkiness. However, bulkiness can be achieved by producing staple fibers with a structurally differential crimp structure. Furthermore, when the staple fibers with a structurally differential crimp structure are hollow staple fibers with a hollow cross section, bulkiness is even more readily achieved.

[0076] There are no particular restrictions on the finishing oil, but it is preferable to apply a silicone-based oil and a crosslinking agent uniformly and crosslink them in the drying process.

[0077] Examples of silicones that serve as the main component of the silicone oil agent referred to here include dimethylpolysiloxane, hydrogenmethylpolysiloxane, aminopolysiloxane, and epoxypolysiloxane, and these can be used alone or in combination. A single silicone is preferred because a smaller number-average molecular weight of the silicone facilitates adjustment with the crosslinking agent and control of the reaction time. The silicone may be substituted with various functional groups at its terminals and side chains to adjust the solution stability as an oil agent and the crosslinking reactivity of film formation, within a range that does not impair the objectives of the present invention. A bifunctional silane coupling agent is preferably used as the crosslinking agent. This promotes two-dimensional crosslinking of the silicone and prevents the formation of excessively large crosslinked products due to three-dimensional crosslinking, allowing the film desired by the present invention to be efficiently formed. The crosslinking reactivity can also be appropriately adjusted by appropriately changing the functional group of the crosslinking agent. After applying the silicone-based oil agent, it is desirable to dry it at a desired temperature and time to allow the crosslinking reaction to occur.

[0078] [Mixing Method] The mixing method of the aliphatic polyamide hollow staple fiber A and other staple fibers is not limited as long as it satisfies the range specified in the present invention, but includes a method of mixing using a multi-mixer, a stock bin, a mixing opener, and a method of mixing by air flow in a cylindrical dispersing device. A multi-mixer is a method in which raw materials are supplied little by little to 1 to 8 parallel reserve boxes with a phase shift, and mixed uniformly.

[0079] [Thermal Insulation Material] The thermal insulation material of the present invention may be in any form of nonwoven fabric, and may be in the form of granular cotton or an aggregate thereof, sheet cotton, or irregularly shaped cotton.

[0080] Examples of the form of granular cotton include fiber balls (fiber spheres) and shredded cotton.

[0081] Preferred examples of sheet cotton include air-laid nonwoven fabrics, thermal bonded nonwoven fabrics, and chemical bonded nonwoven fabrics.

[0082] Examples of the irregular shaped cotton include open fiber cotton.

[0083] As the granular cotton, fiber balls and shredded cotton are particularly preferred from the viewpoint of bulkiness and recovery after compression. Since open-fiber cotton has poor recovery and may significantly reduce the appearance quality after compression, it is advisable to select a nonwoven fabric form that meets the required characteristics when using it.

[0084] One method for forming granular cotton is to thoroughly open the fibers using a card equipped with multiple rollers with garnet wire on the surface, then blow the fully opened fibers into a chamber equipped with a rotating body equipped with multiple fins in a cylindrical space where air turbulence is likely to occur, and form granular cotton by turbulent stirring for a predetermined period of time. Alternatively, the fully opened fibers can be further fed into a mixer (with multiple small chambers) and uniformly mixed, and then mechanical force from fins or needle rollers can be applied in the ball-forming process, causing the fibers with three-dimensional crimp to intertwine and form granular cotton.

[0085] For sheet cotton, chemical bonding and thermal bonding are particularly preferred from the viewpoint of bulkiness and compressibility. This is because, if needle punching or water punching is performed in a loosely spread state, the fibers tend to become dense in the manufacturing process, making it difficult to utilize the structural crimp, and the bulkiness per unit mass tends to decrease, so care must be taken.

[0086] A preferred method for producing the air-through type thermal bonded nonwoven fabric is described below.

[0087] Each staple fiber to be blended is opened using needle rollers, and the weight of the thoroughly pre-opened fibers is measured on a scale. An amount appropriate for the blend ratio is dropped onto a belt conveyor. Since a large input weight can easily lead to inconsistent blend ratios, it is preferable to add the fibers in increments of 0.1 kg to 10 kg per load. The fibers are transported on a belt conveyor, undergo a pre-opening process, and then fed into the mixer using a fan. The mixer is divided into 3 to 10 small chambers, each with a roller at the bottom. The fibers are opened and then conveyed in small amounts from each chamber, blending the fibers and sending them to the fine opener. The fibers are then opened again using needle rollers and sheeted using a carding machine. Depending on the basis weight, several layers of the sheeted fibrous web may be stacked, and the fibrous web is passed through a heat-setting machine that emits hot air to fuse the fusible raw cotton and improve the strength of the sheet-like fiber web. A hot air temperature of 100 to 180°C is preferred, relative to the temperature range of the fusible fibers. Thereafter, the edge of the sheet-like fiber web is slit to obtain a thermal bonded nonwoven fabric.

[0088] The heat insulating material thus obtained has excellent compressibility and compression recovery rate, and therefore when it is compactly stored in a storage container such as a storage bag and taken out after storage, it has excellent shape recovery.

[0089] In the present invention, a compressibility of 45% or more, and preferably 48% or more, allows a textile product containing the heat-insulating material to be compactly stored in a storage bag or the like. The upper limit is preferably 90% or less, from the viewpoint of ease of shape recovery when removed from the storage bag. The compressibility here is a value measured by the method described below.

[0090] Furthermore, the compression recovery rate is preferably 50% or more, and more preferably 55% or more, from the viewpoint of ease of shape recovery when removed from the storage bag. The compression recovery rate referred to here is a value measured by the method described below. When the compression rate and compression recovery rate both satisfy the above ranges, the material can be compactly stored in a storage bag and has excellent shape recovery when removed, resulting in excellent portability. Furthermore, when used in bedding such as sleeping bags, the material also has excellent portability. Furthermore, the material is also excellent in that it can be stored compactly during storage.

[0091] The heat insulating material of the present invention has excellent compressibility, and therefore in a preferred embodiment, it is possible to achieve a storage bag diameter of 0.8 cm or less per 1 g of heat insulating material, and in a more preferred embodiment, it is possible to achieve a storage bag diameter of 0.6 cm or less. The storage bag diameter is a value measured by the method described below, and is used to evaluate how compactly the heat insulating material of the present invention can be stored when the packed object is stored in the storage bag.

[0092] Furthermore, because the heat-insulating material of the present invention has excellent recyclability, the aliphatic polyamide content is preferably 95% by mass or more, and more preferably 99% by mass or more. In particular, the content of polycaproamide (nylon-6) is preferably 95% by mass or more, and more preferably 99% by mass or more. The above range can be achieved by using only the above materials, by controlling the mixing ratio of short fibers other than the above materials, or by controlling the mixing ratio of non-fibrous components such as adhesives used in chemically bonded nonwoven fabrics.

[0093] [Stuffing material] The heat-insulating material of the present invention thus obtained can be filled into a cover and suitably used as a stuffing material. A textile product can then be made that contains at least a portion of such a stuffing material. Furthermore, since the heat-insulating material of the present invention has excellent compressibility and compression recovery, by forming it into a textile product with a storage bag that can store and remove it, the portability and storage storability can be further improved.

[0094] From the viewpoint of the storage and recycling of the garment, the preferred fabric for both the outer and inner linings is a 5 to 40 dtex aliphatic polyamide, preferably made of nylon 6 yarn. The preferred fabric form is a thin woven fabric that is easy to compress and does not easily cause stuffing to blow out. The basis weight is 5 to 100 g / m. ２ In view of ease of compression, it is particularly preferable to use a material having a density of 5 to 50 g / m ２ More preferably, the weight per unit area is:

[0095] From the viewpoint of recycling, sewing threads are preferably made of aliphatic polyamides, particularly polycaproamide (nylon 6), and accessory materials such as piping, buttons, and zippers are also preferably made of aliphatic polyamides, particularly nylon 6. Buttons and zippers generally contain glass fillers, but because these become impurities during recycling, the amount added is preferably 50% by mass or less of the mass of the buttons, zippers, and other materials containing the impurities.

[0096] In terms of recyclability, the textile product of the present invention preferably contains 95% by mass or more of aliphatic polyamide as a material constituting the textile product, and more preferably 95% by mass or more of polycaproamide. To achieve the above range, the content of materials other than the above-mentioned preferable materials in terms of recycling, including the heat-insulating material, the outer fabric, and the above-mentioned accessory parts, may be set to 5% by mass or less in the textile product.

[0097] The textile product of the present invention has excellent compressibility and compression recovery, and therefore can be preferably used for clothing such as jackets and pants containing a padded material with a heat-insulating material filled in the side fabric, clothing accessories such as gloves, scarves, and hats, and bedding such as sleeping bags, futons, beds, and pillows, and can be particularly preferably used for clothing.

[0098] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0099] <Measurement Method> [Hollow Ratio] The hollow ratio referred to here is the volume fraction of the portion of the fiber in which no material is present, and can be measured by the following method. Specifically, aliphatic polyamide hollow short fibers are embedded in epoxy resin or the like so that their cross sections can be observed, and then cut perpendicular to the fiber axis to obtain ultrathin sections. The fiber cross sections are then photographed with a scanning electron microscope (SEM) at a magnification that allows the cross sections of 10 or more hollow fibers to be observed. Ten hollow fibers are randomly selected from the photographed image, and the equivalent circle diameters of the fibers and hollow portions are measured using image processing software. The area ratio of the hollow portions is then calculated from the measured diameter.

[0100] Here, when the number of hollow cross section fibers that can be observed in one image is less than 10, the total number of hollow cross section fibers that can be observed is extracted, and the area ratio of the hollow portion is calculated. The above operation is performed for 10 images taken, and the average value of the 10 images is used as the hollow ratio of the hollow cross section fiber of the present invention.

[0101] When the hollow cross section fiber has a round cross section, the hollowness can be easily evaluated by the following method. The side surface of the hollow cross section fiber is observed using a magnifying means such as a microscope, and the fiber diameter converted to a round cross section is measured from the image. From this fiber diameter and the density of the fiber material, it is also possible to calculate the hollowness as the ratio of the measured fineness to the fineness of a solid fiber.

[0102] When evaluating the hollow ratio of the aliphatic polyamide hollow short fibers A contained in the thermal insulation material after blending, the thermal insulation material is cut and sampled, and ultrathin sections are prepared in the same manner as above. The aliphatic polyamide hollow short fibers A are identified using a scanning electron microscope (SEM), the cross-sectional portions of the fibers are confirmed, and the circle-equivalent diameters of the fibers and hollow portions are measured using image processing software, from which the area ratio of the hollow portions is calculated.

[0103] [Single fiber fineness]: The single fiber fineness was measured by the method specified in JIS L1015 (2010 edition 8.5.1) Method B.

[0104] [Fiber length]: The fiber length was determined by the method specified in JIS L1015 (2010 edition 8.4.1) Method C.

[0105] [Arc radius ratio]: Calculated by the method described above. In this example, samples were taken from each staple fiber before blending without damaging the crimp. When samples were taken from the blended cotton, they were also taken from the blended cotton without damaging the crimp, and each staple fiber was identified and classified by fiber type before being used for measurement.

[0106] [Measurement of Compression Ratio and Compression Recovery Ratio] Measurements were performed in accordance with the synthetic fiber quilt batting test method of JIS L1097-1982 under the following conditions: Sample size (amount): 10 cm x 15 cm box used (cotton sample 8 g) Initial load: 10 cm x 15 cm (0.1 g / cm ２Load: 300 g Initial height and height after 3 minutes of contraction: Initial load: 0.1 g / cm ２ The height after 30 seconds of compression was measured at four points. ２ The material was placed on the sheet and compressed for 30 seconds, after which measurements were taken at four points. The calculation formulas are as follows: Compression rate (%) = ((h0 - h1) / h0) x 100 Compression recovery rate (%) = ((h2 - h1) / (h0 - h1)) x 100 h0: Initial height Average height of the four corners (mm) h1: Height after 30 seconds of compression Average height of the four corners (mm) h2: Height after 3 minutes of release Average height of the four corners (mm) [Heat retention]: Heat retention was determined by measuring the heat retention of the filling according to the method specified in ASTM D 1518-85 (2003).

[0107] In the case of sheet cotton, the weight of the sample is 100 g / m ２ The padding is adjusted to a weight of 100 g / m2 by placing an appropriate frame on the CLO value measuring machine. ２ The mixture was filled uniformly and then measured.

[0108] [Storage test <Conditions for creating a cushion-shaped stuffed object>] Fabric used: Nylon taffeta (warp 70 dtex-12F, weft 70 dtex-24F, warp density 108 threads / 2.54 cm, weft density 82 threads / 2.54 cm, basis weight 70 g / m ２ ) (In this example, nylon 6 taffeta manufactured by Irozome Co., Ltd. was used.) Filling size: Cushion-shaped, 65 cm long x 50 cm wide (finished dimensions) Quilt pitch: Horizontal quilt width 5.5 cm Sewing thread: (1) Upper thread: Nylon 6 100%, 117 dtex, 1 x 3 (3 cords) (2) Lower thread: Nylon 6 100%, 117 dtex, 1 x 3 (3 cords) Sewing conditions: 3 cm, 14-15 needles Sewing method: Use a single piece of fabric for the filling of the cushion-shaped stuffing, fold it in half and sew both sides, fill it with insulation, and then sew the last side (seam allowance 1 cm on each side). Then quilt using the above quilt pitch.

[0109] Filling amount: 32 g of granular cotton such as fiber balls and torn cotton was filled into one cushion-shaped stuffing. One sheet of cotton sheet equivalent to 32 g was inserted. If the amount was less than 32 g, it was stacked to make it equivalent to 32 g and then measured.

[0110] <Conditions for manufacturing storage bags> Storage bag: Fabric used: Use the same fabric as the lining of the cushion-shaped stuffing item described above.

[0111] Storage bag size: 21cm length x 30cm width, 6cm gusset (finished dimensions) Sewing thread: (1) Upper thread: Nylon 6 100% 117dtex 1x3 (3 cords) (2) Lower thread: Nylon 6 100% 117dtex 1x3 (3 cords) Sewing conditions: 3cm 14-15 stitches Sewing method: The storage bag was made by folding a single piece of fabric and sewing two vertical sides together to form a bag with an opening (seam allowance of 1cm on each side). The opening was sewn leaving an opening for the contents to be stuffed (seam allowance of 1cm). The opening was located on the edge of the excess material, described below. The storage bag was 30cm wide, and the gusset at the bottom of the bag was 6cm when pinched. A similar gusset was also created at the top of the part for storing contents, described below.

[0112] <Test Method> Two of the cushion-shaped items were folded lengthwise into thirds, then tightly rolled horizontally around the vertical axis, with the rolled axial direction aligned with one of the vertical sides of the storage bag. A clip with a vertical length was used to separate the filled portion (the portion containing the items) from the empty portion (the excess portion). The clip was used to secure the filled portion so that the items were tightly packed. The tightness of the filled portion was determined by confirming that the crush rate, as determined by the following method, was 0%. To ensure that the filled portion remained tightly packed even after the clip was removed, the same thread used in manufacturing the storage bag was used to sew the filled portion together. The excess portion was wrapped around the filled portion to prevent unnatural wrinkles, creating a roughly cylindrical filled object storage container.

[0113] [Crushing rate] According to the method for measuring the compressibility described above, a load was applied to the packed object storage portion under the following conditions to measure the crushing rate. Initial load: 6 cm x 21 cm (0.1 g / cm ２) Load: 50 g Initial height: Initial load: 0.1 g / cm ２ The weight was placed on the bag and measurements were taken at four locations. The height after 30 seconds of compression was measured at four locations after 30 seconds of compression with the above load applied. The formula for each calculation is as follows: Crush rate (%) = ((H0 - H1) / H0) x 100 H0: Initial height Average height of the four corners (mm) H1: Height after 30 seconds of compression Average height of the four corners (mm) The circumference of the body of the resulting stuffed object storage item was measured at the top (5 cm below the top end), center, and bottom (5 cm below the bottom end), and the diameter was measured assuming that the cross section of the body of the stuffed object storage item was a perfect circle. The average value was calculated and used as the actual storage bag diameter. The storage bag diameter (cm / g) per 1 g of insulation was calculated using the following formula. Storage bag diameter per 1 g of thermal insulation (cm / g) = actual storage bag diameter (cm) / amount of thermal insulation filled (g) In the above, the fact that the storage bag diameter becomes smaller when two cushion-shaped stuffing objects are stacked and stored in a storage bag means that the storability of clothing such as jackets and pants that contain thermal insulation can be evaluated as a model when the front and back body parts are stacked and folded and stored in a storage bag, or when storing textile products such as sleeping bags.For stuffing objects of the same size, the smaller the actual storage bag diameter, the more compactly they can be stored, and the better their storability and portability.By evaluating the storage bag diameter per unit mass, it is possible to evaluate how compactly they can be stored, regardless of size.

[0114] [Evaluation of Loft] The loft was analyzed by the following method.

[0115] Five experts performed a sensory evaluation of the feel of the cushion-shaped stuffed objects created in the storage test. The evaluation was conducted on a three-level scale based on the following criteria. The most common evaluation was used, and in the case of a tie, the lower evaluation result was used. Evaluation criteria for loft of filling: 3: Soft and fluffy, equivalent to down 2: Slightly soft and fluffy 1: Weak fluffiness [Sensory evaluation] Softness was analyzed using the following method.

[0116] The feel of the cushion-shaped stuffing objects created in the storage test was evaluated by a sensory evaluation by five experts. The evaluation was made on a three-level scale based on the following criteria. The most common evaluation was used, and in the case of a tie, the lower evaluation result was used.

[0117] Evaluation criteria for the feel of the filling: 3: Soft feel, the form of the filling is not visible. 2: Slightly soft feel, the form of the filling is slightly visible. 1: Rough and hard feel, the form of the filling is visible.

[0118] [Evaluation of Resistance to Stuffiness] Resistance to stuffiness was analyzed by the following method.

[0119] Jackets filled with the padding (70 g / wear) of the Examples and Comparative Examples were worn, and the jackets were walked for 10 minutes in an environment of 15°C x 90% humidity, and the stuffiness after sitting for 3 minutes was evaluated by a sensory evaluation by five skilled experts. The evaluation was made on a three-level scale based on the following criteria. The most common evaluation was adopted, and in the case of a tie, the lower evaluation result was adopted. Evaluation criteria for resistance to stuffiness: 3: No stuffiness and comfortable 2: Slight stuffiness but comfortable 1: Stuffiness and uncomfortable [Recyclability evaluation] Recyclability was evaluated by the following method.

[0120] The ease of chemical recycling of the product was evaluated on the assumption that both the outer fabric and sewing thread were made of nylon 6. For chemical recycling, 100% nylon 6 is most preferable, but recycling is possible even if it contains less than 5% of something other than nylon 6. If it exceeds 5%, a large amount of residue is generated during polymerization, which significantly reduces the yield and makes recycling difficult. Using the cushion-shaped stuffing object used in the storage test, an evaluation was conducted on the following three levels.

[0121] Recyclability evaluation criteria: ○: Nylon 6 constitutes 99% or more by mass of the insulation (including outer fabric, batting, and sewing thread) △: Nylon 6 constitutes 95% or more by mass and less than 99% by mass of the insulation (including outer fabric, batting, and sewing thread) ×: Nylon 6 constitutes less than 95% by mass of the insulation (including outer fabric, batting, and sewing thread) [Example 1] Aliphatic polyamide hollow staple fibers A were prepared using hollow raw cotton a made of nylon 6 with a single filament fineness of 7.7 dtex and a fiber length of 25 mm and three-dimensional crimping, and staple fibers B were prepared using hollow raw cotton b made of nylon 6 with a single filament fineness of 2.2 dtex and a fiber length of 25 mm and three-dimensional crimping, and the mixture was pre-opened using a needle roller, mixed in a mixer at a mass ratio of 50:50, opened again using a fine opener, and shredded using a carding machine. The blend of thick and thin hollow cotton fibers with three-dimensional crimping provides excellent loft, and the appropriate balance of fiber count and fiber size results in excellent compressibility and compression recovery. The use of 2.2 dtex staple fiber B raw cotton of nylon 6 also provides a good texture, and the insulation material contains 100% nylon 6, making it highly recyclable.

[0122] Example 2: Aliphatic polyamide hollow staple fibers A were prepared from nylon 6 hollow raw cotton a with a single filament fineness of 6.6 dtex, a fiber length of 38 mm, and three-dimensional crimps. Staple fibers B were prepared from nylon 6 raw cotton b with a single filament fineness of 1.7 dtex, a fiber length of 38 mm, and buckling crimps. These were pre-opened using a needle roller, mixed in a mixer at a mass ratio of 90:10, opened again using a fine opener, and torn into a cotton-like shape using a carding machine. Blending the thick and thin hollow raw cotton with three-dimensional crimps resulted in excellent loft. Although compressibility and compression recovery were slightly inferior to those of Example 1 due to the blending of buckling crimped raw cotton, the texture was excellent due to the use of 1.7 dtex staple fibers B. Furthermore, since the nylon 6 content in the thermal insulation material was 100% by mass, recyclability was also good.

[0123] [Example 3] Aliphatic polyamide hollow staple fiber A was made of nylon 6 hollow raw cotton a having a single filament fineness of 6.6 dtex, a fiber length of 38 mm, and three-dimensional crimp; staple fiber B was made of nylon 6 raw cotton b having a single filament fineness of 1.7 dtex, a fiber length of 38 mm, and buckling crimp; and staple fiber C was made of nylon 6 hollow raw cotton c having a single filament fineness of 2.2 dtex, a fiber length of 38 mm, and three-dimensional crimp. These were pre-opened using a needle roller, mixed in a mixer at a mass ratio of 50:10:40, and opened again using a fine opener. A fibrous web was prepared using a carding machine, and three layers were laminated using the cross-web method. An acrylic adhesive resin was sprayed on the mixture and heat-set at 160°C to obtain a sheet cotton. By blending thick and thin hollow raw cotton fibers with three-dimensional crimping, a chemically bonded nonwoven fabric was obtained that has excellent bulk, compressibility, and compression recovery. The fabric has excellent texture due to the use of 1.7 dtex short fiber B, and the insulation material contains more than 99% by mass of nylon 6, making it easily recyclable.

[0124] [Example 4] Aliphatic polyamide hollow staple fiber A was prepared by pre-opening a nylon 6 hollow raw cotton a having a single filament fineness of 7.7 dtex, a fiber length of 25 mm, and a three-dimensional crimp. Fiber B was prepared by pre-opening acrylic raw cotton b having a single filament fineness of 0.9 dtex, a fiber length of 38 mm, and a buckling crimp. The fibers were then mixed in a mixer at a mass ratio of 95:5, opened again with a fine opener, and shredded using a carding machine. By blending the thick hollow raw cotton having a three-dimensional crimp with the soft acrylic fine raw cotton having a low Young's modulus, shredded cotton with excellent bulk and texture was obtained. Furthermore, since the insulation material contains 95% by mass of nylon 6, it is recyclable.

[0125] [Comparative Example 1] Raw cotton a having a nylon 6 single filament fineness of 8.8 dtex, a fiber length of 38 mm, and buckling crimp, raw cotton b having a nylon 6 single filament fineness of 6.6 dtex, a fiber length of 38 mm, and buckling crimp, and raw cotton c having a nylon 6 single filament fineness of 1.7 dtex, a fiber length of 38 mm, and three-dimensional crimp were pre-opened using needle rollers and mixed in a mixer in a mass ratio of 50:30:20, and sheet cotton was obtained in the same manner as in Example 3.

[0126] Since it does not contain the aliphatic polyamide hollow short fibers A having three-dimensional crimps, it has low loft and low compressibility, and since the fiber direction is planar, it has poor compression recovery rate.

[0127] [Comparative Example 2] Torn cotton was prepared in the same manner as in Example 1, except that only hollow raw cotton a made of polyethylene terephthalate with a single filament fineness of 3.3 dtex and a fiber length of 38 mm and three-dimensional crimping was used. Because polyethylene terephthalate was used, the resulting torn cotton had a sense of loft, but was poor in compressibility due to its small compression under low loads. Furthermore, if the filling is polyethylene terephthalate staple fiber, the outer fabric and the filling must be separated when chemically recycling the product, which also makes it less recyclable.

[0128] [Comparative Example 3] Hollow raw cotton a having a nylon 6 single filament fineness of 7.7 dtex, a fiber length of 25 mm, and three-dimensional crimp, and raw cotton b having a nylon 6 single filament fineness of 1.7 dtex, a fiber length of 38 mm, and buckling crimp were pre-opened using needle rollers and mixed in a mixer in a mass ratio of 50:50, and shredded cotton was obtained in the same manner as in Example 1.

[0129] Although it contains hollow raw cotton with three-dimensional crimping, the proportion of buckling crimped raw cotton is high and the initial loft is low, so it has low compressibility and poor compression recovery rate.

[0130] [Comparative Example 4] Raw cotton a having a nylon 6 single filament fineness of 8.8 dtex, a fiber length of 38 mm, and a buckling crimp, and raw cotton b having a nylon 6 single filament fineness of 1.7 dtex, a fiber length of 38 mm, and a buckling crimp were pre-opened using needle rollers and mixed in a mixer at a ratio of 80:20, and shredded cotton was obtained in the same manner as in Example 1.

[0131] The fibers were only composed of buckling crimps, which resulted in weak intertwining of the fibers, low loft, and uneven torn cotton.In addition, the fibers were oriented in a planar direction, resulting in a low compression recovery rate.

[0132] [Comparative Example 5] Raw cotton a having a polyethylene terephthalate single filament fineness of 1.3 dtex and a fiber length of 38 mm and buckling crimp, raw cotton b having a polyethylene terephthalate single filament fineness of 1.8 dtex and a fiber length of 38 mm and buckling crimp, and hollow raw cotton c having a polyethylene terephthalate single filament fineness of 7.6 dtex and a fiber length of 64 mm and three-dimensional crimp and buckling crimp were torn into pieces in the same manner as in Comparative Example 2. Because it was torn polyethylene terephthalate, it had a loft, but was poorly compressible under low loads and had poor compressibility. In addition, the raw cotton with a single filament fineness of 7.6T was given a structurally different crimp and then given a buckling crimp using a crimper, and the loose and large three-dimensional crimp was broken up into small pieces by the buckling crimp, resulting in a low compression recovery rate. Furthermore, if the padding is polyethylene terephthalate, the outer fabric and padding must be separated when chemically recycling the product, making it less recyclable.

[0133] [Comparative Example 6] Cotton sheets were prepared in the same manner as in Comparative Example 1 using raw cotton a, a two-component bimetallic material made of polybutylene terephthalate and polyethylene terephthalate (PBT / PET) with a single filament fineness of 3.3 dtex and a fiber length of 64 mm, and fine crimp due to the two-component bimetallic material, raw cotton b, a polyethylene terephthalate single filament fineness of 1.8 dtex and a fiber length of 64 mm, and buckling crimp, and raw cotton c, a polyethylene terephthalate single filament fineness of 1.3 dtex and a fiber length of 64 mm, and buckling crimp. Raw cotton a was two-component, and thus fine crimp was expressed, and because it was torn polyethylene terephthalate cotton, it had a loft, but the compression at low loads was small, and torn cotton with poor compressibility was obtained.

[0134]

[0135]

[0136] h: Height of crimped peak w: Width of base of crimped peak

Claims

1. A heat-insulating material composed of fibers containing 95% by mass or more of aliphatic polyamide staple fibers, satisfying the following (1) to (3): (1) At least a part contains aliphatic polyamide hollow staple fibers A having a differential shrinkage crimp structure with a single-component fineness of 3 to 10 dtex. (2) It contains one or more types of staple fibers different from the aliphatic polyamide hollow staple fibers A, and the ratio of the fineness of the aliphatic polyamide hollow staple fibers A to the fineness of the finest staple fiber B among them is 1.5 or more, and the crimp number is also different from the crimp number of the aliphatic polyamide hollow staple fibers A. (3) The compression ratio is 45% or more.

2. The heat-insulating material according to claim 1, wherein the compression recovery rate of the heat-insulating material is 50% or more.

3. The heat-insulating material according to claim 1 or 2, wherein the single fiber fineness of the staple fiber B is 0.3 to 3 dtex.

4. The heat-insulating material according to claim 1 or 2, wherein in the fibers constituting the heat-insulating material, the aliphatic polyamide hollow staple fibers A are 30 to 97% by mass, the finest staple fiber B is 3 to 70% by mass, and the remaining other staple fibers C are 0% by mass or more.

5. The heat-insulating material according to claim 1 or 2, wherein the mixing ratio of the staple fibers having a differential shrinkage crimp structure in the fibers constituting the heat-insulating material is 55% by mass or more.

6. The heat-insulating material according to claim 1 or 2, wherein the hollowness ratio of the aliphatic polyamide hollow staple fibers A is 5% to 60%.

7. The heat-insulating material according to claim 1 or 2, wherein the heat-insulating material contains 95% by mass or more of polycaproamide.

8. The heat-insulating material according to claim 1 or 2, wherein the diameter of the storage bag per 1 g of the heat-insulating material is 0.8 cm or less.

9. A fiber product containing at least a part of a stuffed object filled with the heat-insulating material according to claim 1 or 2 in the lining.

10. The fiber product according to claim 9, containing 95% by mass or more of polycaproamide.

11. The fiber product according to claim 9, wherein the fiber product is a clothing item.

12. A product with a storage bag, comprising the fiber product according to claim 9 and a storage bag capable of storing and taking out the fiber product.

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