Hollow nonwoven fabric and production method therefor

Abstract

A nonwoven fabric according to the present disclosure comprises a spunbond nonwoven fabric. The spunbond nonwoven fabric contains hollow fibers having a thermoplastic resin as a principal component. The mode value in a grayscale image of the nonwoven fabric is 150 or higher. The tensile strength in the machine direction (MD) per basis weight of the nonwoven fabric is 1.00 (N / 25 mm) / gsm to 2.00 (N / 25 mm) / gsm.

Description

Hollow nonwoven fabric and method for manufacturing the same

[0001] This disclosure relates to hollow nonwoven fabrics and methods for manufacturing the same. More specifically, this disclosure relates to nonwoven fabrics, textile products, sanitary products, and methods for manufacturing nonwoven fabrics.

[0002] Nonwoven fabrics are widely used in various applications due to their excellent breathability, flexibility, and lightweight properties. One known method for reducing the weight of nonwoven fabrics is to use hollow fibers to make up the fibers that make up the nonwoven fabric.

[0003] Patent Document 1 discloses a spunbond nonwoven fabric made of hollow fibers of a specific propylene polymer. Patent Document 1 specifically discloses that the spunbond nonwoven fabric was manufactured at a single-pore discharge rate of 0.52 g / min.

[0004] Patent Document 1: Patent No. 5717769

[0005] Spunbond nonwoven fabrics containing hollow fibers (hereinafter also referred to as "nonwoven fabrics") are required to be lighter than nonwoven fabrics containing solid fibers, depending on the application (i.e., the amount of thermoplastic resin used for hollow fibers in a nonwoven fabric is reduced compared to solid fibers of the same volume as hollow fibers), and to have superior uniformity and tensile strength per basis weight.

[0006] However, when spunbond nonwoven fabrics containing hollow fibers are manufactured at high speed, thread breakage of the hollow fibers can occur easily during the manufacturing process. It has been found that a high incidence of thread breakage affects the uniformity and tensile strength per unit weight of the nonwoven fabric compared to cases where thread breakage is minimal.

[0007] The object of one embodiment of the present disclosure, made in view of the above, is to provide a nonwoven fabric, textile product, and sanitary product containing hollow fibers that are excellent in uniformity and tensile strength per basis weight. The object of another embodiment of the present disclosure, made in view of the above, is to provide a method for manufacturing a nonwoven fabric that can control the occurrence of thread breakage and produce a spunbond nonwoven fabric containing hollow fibers that is excellent in uniformity and tensile strength per basis weight.

[0008] The following embodiments are included as means for solving the above problems: <1> A nonwoven fabric having a spunbond nonwoven fabric containing hollow fibers mainly composed of a thermoplastic resin, wherein the mode in a grayscale image of the nonwoven fabric is 150 or more, and the tensile strength in the flow direction (MD) per basis weight of the nonwoven fabric is 1.00 (N / 25 mm) / gsm to 2.00 (N / 25 mm) / gsm. <2> The nonwoven fabric according to <1>, wherein the coefficient of variation of the hollowness ratio of the hollow fibers in the spunbond nonwoven fabric is 14.0% or less. <3> The value represented by the following formula (I) in the spunbond nonwoven fabric is 200% ３ ~250% ３ The nonwoven fabric described in <1> or <2> above. Formula (I): (Coefficient of variation of the fiber diameter of the hollow fibers) ２× Coefficient of variation of the hollowness of the hollow fibers <4> The nonwoven fabric according to any one of <1> to <3>, wherein the thermoplastic resin is made of an olefin polymer, the melt flow rate of the olefin polymer is 15 g / 10 min to 80 g / 10 min, and the melt flow rate is a measured value obtained in accordance with ASTM D-1238 under conditions of 230°C and a load of 2.16 kg. <5> The nonwoven fabric according to any one of <1> to <4>, wherein the hollow fibers contain a plasticizer. <6> The nonwoven fabric according to any one of <1> to <5>, wherein the basis weight of the nonwoven fabric is 5.0 gsm to 20.0 gsm. <7> The nonwoven fabric according to any one of <1> to <6>, further comprising at least one member of another nonwoven fabric and film different from the spunbond nonwoven fabric, wherein the member is disposed on at least one main surface of the spunbond nonwoven fabric. <8> A textile product comprising the nonwoven fabric according to any one of <1> to <7>. <9> A sanitary product comprising the nonwoven fabric according to any one of <1> to <7>. <10> A method for manufacturing a nonwoven fabric to produce the nonwoven fabric according to any one of <1> to <7> above, wherein the manufacturing method includes producing the spunbond nonwoven fabric by spin-ray lamination, wherein in the spin-ray lamination, the single-hole discharge rate of the molten thermoplastic resin composition discharged from the nozzle is 0.55 g / min to 1.01 g / min, the take-up rate of the hollow fibers discharged from the nozzle is 2000 m / min to 7500 m / min, the thermoplastic resin composition comprises the thermoplastic resin, and the hollow fibers consist of the thermoplastic resin composition. <11> The method for manufacturing a nonwoven fabric according to <10> above, wherein in the spin-ray lamination, the outlet setting temperature of the extruder for melting the thermoplastic resin composition is 230°C to 250°C.

[0009] <12> A nonwoven fabric having a spunbond nonwoven fabric containing hollow fibers mainly composed of a thermoplastic resin, wherein the coefficient of variation of the basis weight of the nonwoven fabric is 7.4% or less, and the value represented by the following formula (I) in the spunbond nonwoven fabric is 200% ３ 250% ３The following is a nonwoven fabric. Formula (I): (Coefficient of variation of the fiber diameter of the hollow fibers) ２×Coefficient of variation of the hollowness of the hollow fibers <13> The nonwoven fabric according to <12>, wherein the tensile strength in the flow direction (MD) per basis weight of the nonwoven fabric is 1.00 (N / 25 mm) / gsm or more and 2.00 (N / 25 mm) / gsm or less. <14> The nonwoven fabric according to <12> or <13>, wherein the coefficient of variation of the hollowness of the spunbond nonwoven fabric is 14.0% or less. <15> The nonwoven fabric according to <12> to <14>, wherein the mode in the grayscale image of the nonwoven fabric is 150 or more. <16> The nonwoven fabric according to any one of <12> to <15>, wherein the thermoplastic resin is made of an olefin polymer, the melt flow rate of the olefin polymer is 15 g / 10 min or more and 80 g / 10 min or less, and the melt flow rate is a measured value obtained in accordance with ASTM D-1238 under conditions of 230°C and a load of 2.16 kg. <17> The nonwoven fabric according to any one of <12> to <16>, wherein the hollow fibers contain a plasticizer. <18> The nonwoven fabric according to any one of <12> to <17>, wherein the basis weight of the nonwoven fabric is 5.0 gsm or more and 20.0 gsm or less. <19> The nonwoven fabric according to any one of <12> to <18>, further comprising at least one member of another nonwoven fabric and film different from the spunbond nonwoven fabric, wherein the other nonwoven fabric is disposed on at least one main surface of the spunbond nonwoven fabric. <20> A textile product comprising the nonwoven fabric according to any one of <12> to <19>. <21> A sanitary product comprising the nonwoven fabric according to any one of <12> to <19>. <22> A method for manufacturing a nonwoven fabric to produce the nonwoven fabric described in any one of <12> to <19>, wherein the manufacturing method includes producing the spunbond nonwoven fabric by spin-ray lamination, wherein in the spin-ray lamination, the single-hole discharge rate of the molten thermoplastic resin composition discharged from the nozzle is 0.55 g / min or more and 1.01 g / min or less, and the take-up rate of the hollow fibers discharged from the nozzle is 2000 m / min or more and 7500 m / min or less, the thermoplastic resin composition includes the thermoplastic resin, and the hollow fibers are made of the thermoplastic resin composition.<23> The method for producing a nonwoven fabric according to <22>, wherein in the spin-ray lamination, the outlet setting temperature of the extruder for melting the thermoplastic resin composition is 230°C or higher and 250°C or lower.

[0010] Embodiments of the present disclosure provide nonwoven fabrics, textile products, and sanitary products containing hollow fibers that are excellent in uniformity and tensile strength per basis weight. Other embodiments of the present disclosure have been made in view of the above and provide a method for manufacturing nonwoven fabrics that can control the occurrence of thread breakage and produce nonwoven fabrics containing hollow fibers that are excellent in uniformity and tensile strength per basis weight.

[0011] Figure 1 is a schematic diagram showing a closed-type spunbond nonwoven fabric manufacturing apparatus according to an embodiment of the present disclosure. Figure 2 is a schematic diagram of an example of the hole shape of the spinneret slot according to an embodiment of the present disclosure. Figure 3 is the I program code of the image analysis software "ImageJ 1.32S" used to calculate the mode in a grayscale image of the nonwoven fabric in the embodiment.

[0012] In this disclosure, the "~" indicating a numerical range is used to mean that the numbers before and after it are included as the lower and upper limits. In numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. In numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with the values ​​shown in the examples. In this disclosure, the term "process" is included not only in the sense of an independent process, but also in the sense of achieving the intended purpose of the process, even if it cannot be clearly distinguished from other processes. In this disclosure, when referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, it means the total amount of multiple substances present in the composition unless otherwise specified. "gsm" (grams per square meter) means g / m ２ This indicates.

[0013] (1) Embodiments (1.1) Nonwoven Fabric The nonwoven fabric according to the embodiment (i.e., hollow nonwoven fabric) is a nonwoven fabric having a spunbond nonwoven fabric (hereinafter also referred to as "SB nonwoven fabric"). The spunbond nonwoven fabric contains hollow fibers mainly composed of a thermoplastic resin. The mode of the grayscale image of the nonwoven fabric (hereinafter also referred to as "mode") is 150 or more. The tensile strength in the flow direction (MD) per basis weight of the nonwoven fabric (hereinafter also referred to as "tensile strength per basis weight") is 1.00 (N / 25mm) / gsm to 2.00 (N / 25mm) / gsm.

[0014] "Nonwoven fabric" refers to a planar fiber aggregate in which a predetermined level of structural strength is obtained by at least one of physical and chemical methods, excluding weaving, knitting, and papermaking. "Nonwoven fabric" includes single-layer nonwoven fabrics consisting of one nonwoven fabric and laminated nonwoven fabrics in which at least two webs or nonwoven fabrics are laminated. "Web" refers to a sheet composed solely of fibers. "Hollow fiber mainly composed of thermoplastic resin" means that the ratio of the mass of thermoplastic resin to the total mass of the hollow fiber is 80% by mass or more, may be 90% by mass or more, and may be 95% to 100% by mass. "Hollow fiber" refers to a straw-shaped filament. More specifically, one hollow fiber has one or more hollow parts extending along the fiber axis direction inside. "Spunbond nonwoven fabric" refers to a nonwoven fabric made by at least one bonding method (e.g., embossing) to a spunlaid web (hereinafter also referred to as "SB web"). "Spunlaid web" refers to a web laminated by spinlay lamination. "Spin-ray lamination" refers to a method of creating a web by extruding molten or dissolved polymer from a spinneret (i.e., a spinning hole) (hereinafter also referred to as a "nozzle") and laminating filaments (e.g., hollow fibers) onto a moving screen. "Mode in the grayscale image of the nonwoven fabric" refers to the grayscale level with the largest number of pixels when multiple pixels constituting the grayscale image (resolution: 6400 dpi (dots per inch)) of the surface of the nonwoven fabric (size: 1.5 inch x 2 inch) are classified by grayscale level. The grayscale of the pixels is represented by a 251-level gradient (black: 0, white: 250) between 0 and 250. A grayscale of 150 or more indicates that the fibers constituting the nonwoven fabric are relatively uniformly dispersed in the planar and thickness directions. The method for measuring the mode is the same as that described in the examples. "Tensile strength in the flow direction (MD)" refers to the tensile strength of the nonwoven fabric in the flow direction (MD) of the nonwoven fabric. The method for measuring the tensile strength in the flow direction (MD) of the nonwoven fabric (hereinafter also referred to as "MD tensile strength") is the same as the method described in the examples.

[0015] The flow direction (MD) of a nonwoven fabric can be determined from the nonwoven fabric itself by measuring its tensile strength. Generally, in the manufacturing of nonwoven fabrics, the screen movement speed is set to a high speed from the viewpoint of productivity. Therefore, the hollow fibers contained in the web tend to be oriented in a direction parallel to the flow direction (MD) when laminated on the screen. As a result, the tensile strength in the flow direction (MD) of the nonwoven fabric is higher than the tensile strength in the direction perpendicular to the flow direction (CD) (hereinafter also referred to as the "width direction (CD)"). Therefore, the flow direction (MD) can be determined from the nonwoven fabric itself by measuring its tensile strength.

[0016] The nonwoven fabric according to the embodiment has the above-described structure and therefore contains hollow fibers (i.e., the nonwoven fabric is lightweight), and exhibits excellent uniformity and tensile strength per basis weight. The mode of the grayscale image of the nonwoven fabric being 150 or higher, or the coefficient of variation of the basis weight of the nonwoven fabric being 7.4% or lower, indicates that the nonwoven fabric is relatively uniform. The tensile strength in the flow direction (MD) per basis weight of the nonwoven fabric being 1.00 (N / 25mm) / gsm to 2.00 (N / 25mm) / gsm indicates that the hollow fibers are well dispersed in the planar and thickness directions of the nonwoven fabric, resulting in excellent uniformity and small variation in the basis weight of the nonwoven fabric. Thus, the nonwoven fabric according to the embodiment exhibits excellent uniformity and tensile strength per basis weight.

[0017] Nonwoven fabric is a sheet-like material. The number of layers of nonwoven fabric is at least one, and is appropriately selected depending on the application of the nonwoven fabric. The number of layers of nonwoven fabric may be one layer (i.e., S structure), two layers (i.e., MS structure and SS structure, etc.), three layers (e.g., SMS structure and SMM structure, etc.), four layers (e.g., SSMS structure, SMSS structure and SMMS structure, etc.), or five or more layers.

[0018] "S structure" refers to SB nonwoven fabric. "MS structure" refers to a structure in which SB nonwoven fabric and meltblown nonwoven fabric (hereinafter also referred to as "MB nonwoven fabric") are laminated. "SS structure" refers to a structure in which two non-identical SB nonwoven fabrics are laminated. "SMS structure" refers to a structure in which SB nonwoven fabric, MB nonwoven fabric, and SB nonwoven fabric are laminated in this order. The two SB nonwoven fabrics in the SMS structure may be identical or different. "SMM structure" refers to a structure in which SB nonwoven fabric, MB nonwoven fabric, and MB nonwoven fabric are laminated in this order. The two MB nonwoven fabrics in the SMS structure may be identical or different. "SSMS structure" refers to a structure in which SB nonwoven fabric, SB nonwoven fabric, MB nonwoven fabric, and SB nonwoven fabric are laminated in this order. The three SB nonwoven fabrics in the SSMS structure may be identical or different. The term "SMMS structure" refers to a structure in which SB nonwoven fabric, MB nonwoven fabric, MB nonwoven fabric, and SB nonwoven fabric are laminated in this order. In the SMMS structure, the two SB nonwoven fabrics may be the same or different, and the two MB nonwoven fabrics may be the same or different. The following examples of SB nonwoven fabrics can basically be applied to SB nonwoven fabrics in a single layer or in a structure in which multiple SB nonwoven fabrics are laminated.

[0019] "Meltblown nonwoven fabric" refers to a nonwoven fabric made by bonding a long-fiber meltblown web with at least one bonding method (e.g., embossing). "Meltblown web" refers to a web made by meltblown lamination. "Meltblown lamination" refers to a method of creating a web by extruding molten polymer into a high-speed, high-temperature gas stream to form filaments, and then laminating these filaments on a moving screen. The average fiber diameter of SB nonwoven fabric is usually 5.0 μm or more. The average fiber diameter of MB nonwoven fabric is usually less than 5.0 μm.

[0020] The mode value in the grayscale image of the nonwoven fabric is 150 or more. When the mode value of the nonwoven fabric containing hollow fibers is 150 or more, the uniformity of the nonwoven fabric is improved. As a result, the tensile strength per basis weight of the nonwoven fabric reaches a desired value or higher. From the viewpoint of uniformity of the nonwoven fabric, the mode value is preferably 150 or more and 240 or less, more preferably 160 or more and 240 or less, still more preferably 164 or more and 240 or less, and from the viewpoint of spinning stability, it is even more preferably 170 or more and 200 or less. From the same viewpoint, the mode value may be 150 or more and 220 or less, 160 or more and 220 or less, 164 or more and 220 or less, 170 or more and 220 or less, 150 or more and 200 or less, 160 or more and 200 or less, 164 or more and 200 or less, 170 or more and 200 or less, 150 or more and 190 or less, 160 or more and 190 or less, 164 or more and 190 or less, or 170 or more and 190 or less. In a nonwoven fabric containing hollow fibers, when the mode value falls within the above range, the uniformity in the plane direction and the thickness direction of the nonwoven fabric can be enhanced. As a result, the tensile strength per basis weight of the nonwoven fabric can be improved.

[0021] Examples of methods for adjusting the mode value to 150 or more include the type, viscosity, melt flow rate and melting point of the thermoplastic resin, the hollow ratio, the coefficient of variation of the hollow ratio, the value represented by formula (I) mentioned later, the fiber diameter, and the nonwoven fabric production method according to the embodiment described below (such as the discharge amount per hole and the take-up speed), and the like.

[0022] The basis weight of the nonwoven fabric is not particularly limited and can be appropriately selected depending on the application of the nonwoven fabric. The basis weight of the nonwoven fabric may be between 5.0 gsm and 200.0 gsm. From the viewpoint of cost competition and the softness of the nonwoven fabric, the basis weight of the nonwoven fabric is preferably between 5.0 gsm and 20.0 gsm. Even if the nonwoven fabric has a low basis weight (for example, between 5.0 gsm and 20.0 gsm), the nonwoven fabric according to the embodiment has excellent tensile strength per basis weight. From the viewpoint of improving tensile strength (absolute value), the basis weight of the nonwoven fabric may be between 10.0 gsm and 200.0 gsm, 10.0 gsm and 150.0 gsm, 10.0 gsm and 100.0 gsm, 10.0 gsm and 50.0 gsm, or 15.0 gsm and 30.0 gsm. From the viewpoint of taking advantage of the characteristics of lower basis weight nonwoven fabrics, the basis weight of the nonwoven fabric may be 15.0 gsm or less, or 10.0 gsm or less, or 5.0 gsm to 15.0 gsm, or 5.0 gsm to 12.0 gsm, or 5.0 gsm or more and less than 10.0 gsm. The method for measuring the basis weight of the nonwoven fabric is the same as the method described in the examples.

[0023] The coefficient of variation Cv (hereinafter also referred to as "basis weight Cv") of the basis weight of a nonwoven fabric quantitatively represents the degree of variation in the basis weight of the nonwoven fabric. A basis weight Cv closer to 0 indicates that the nonwoven fabric is relatively uniform. The basis weight Cv is not particularly limited and is appropriately selected according to the application of the nonwoven fabric. The basis weight Cv of the nonwoven fabric may be 2.0% or more, or 3.0% or more, and may be 7.4% or less, 6.0% or less, 5.3% or less, 5.0% or less, 4.7% or less, or 4.4% or less. From the viewpoint of uniformity and high productivity of the nonwoven fabric, the basis weight Cv of the nonwoven fabric is preferably 2.0% to 7.4%, more preferably 2.0% to 6.0%, even more preferably 2.0% to 5.3%, even more preferably 2.0% to 5.0%, and even more preferably 2.0% to 4.4%. Furthermore, the basis weight Cv of the nonwoven fabric may be 3.0% to 7.4%, 3.0% to 6.0%, 3.0% to 5.3%, 3.0% to 5.0%, or 3.0% to 4.4%. The method for measuring the basis weight Cv of the nonwoven fabric is the same as that described in the examples.

[0024] Examples of methods for adjusting the basis weight Cv include, for example, the type, viscosity, melt flow rate, and melting point of the thermoplastic resin, the hollow percentage, the coefficient of variation of the hollow percentage, the value represented by formula (I) below, the fiber diameter, the degree of fiber fusion, and the nonwoven fabric production method according to the embodiments described later (such as single-hole discharge amount and take-up speed), etc.

[0025] The MD tensile strength per basis weight of the nonwoven fabric is 1.00 (N / 25mm) / gsm to 2.00 (N / 25mm) / gsm. When the MD tensile strength per basis weight of the nonwoven fabric is 1.00 (N / 25mm) / gsm or above, the nonwoven fabric can have the desired durability depending on the application, and the handleability during nonwoven fabric processing can be improved. A higher basis weight leads to a greater number of fibers contained in the nonwoven fabric. Therefore, the MD tensile strength per basis weight tends to increase. In the present disclosure, since the hollow fibers are moderately dispersed in the plane direction and thickness direction of the nonwoven fabric, even if the nonwoven fabric has a low basis weight, the mode value in the grayscale image falls within the desired numerical range, and the MD tensile strength per basis weight falls within the desired numerical range. If the MD tensile strength per basis weight of the nonwoven fabric is 2.00 (N / 25mm) / gsm or below, a decrease in the tensile strength in the width direction (CD) of the nonwoven fabric (hereinafter also referred to as "CD tensile strength") can be suppressed. From the viewpoint of the MD tensile strength per basis weight of the nonwoven fabric and the uniformity of the nonwoven fabric (for example, the mode value, the basis weight Cv, etc. (hereinafter the same applies)), the MD tensile strength per basis weight of the nonwoven fabric is preferably 1.05 (N / 25mm) / gsm or above. Depending on the application, the tensile strength per basis weight of the nonwoven fabric may be 1.08 (N / 25mm) / gsm or above, may be 1.10 (N / 25mm) / gsm or above, may be 1.15 (N / 25mm) / gsm or above, may be 1.80 (N / 25mm) / gsm or below, may be 1.60 (N / 25mm) / gsm or below, and may be 1.40 (N / 25mm) / gsm or below.

[0026] The MD tensile strength of the nonwoven fabric is not particularly limited as long as the MD tensile strength per basis weight of the nonwoven fabric falls within the above range. Depending on the application, the MD tensile strength of the nonwoven fabric may be 6.0 N / 25 mm to 30.0 N / 25 mm. The measurement method for MD tensile strength is the same as the method described in the examples.

[0027] The CD tensile strength of the nonwoven fabric is not particularly limited as long as the MD tensile strength per basis weight of the nonwoven fabric falls within the above range. The CD tensile strength of the nonwoven fabric may be 4.0 N / 25 mm to 20.0 N / 25 mm depending on the application. The method for measuring CD tensile strength is the same as the method described in the Examples.

[0028] Examples of the method for adjusting the MD tensile strength per basis weight of the nonwoven fabric to 1.00 (N / 25 mm) / gsm to 2.00 (N / 25 mm) / gsm include the type, viscosity, melt flow rate and melting point of the thermoplastic resin, the hollow ratio, the coefficient of variation of the hollow ratio, the value represented by formula (I) described later, the fiber diameter, the degree of fiber fusion, and the nonwoven fabric production method according to an embodiment described later (such as the single-hole discharge amount and the take-up speed), etc.

[0029] The nonwoven fabric may have a plurality of embossed fused portions, or may not have any embossed fused portion. The plurality of embossed fused portions may be formed regularly or irregularly. Examples of the shape of the embossed fused portions include circles, ellipses, oblongs, squares, rhombuses, rectangles, other quadrilaterals, and continuous shapes based on these shapes. The embossed fused portions are formed by transferring the embossed markings of an embossing roll. The emboss area ratio of the nonwoven fabric may be the same as the emboss area ratio of the embossing roll. The emboss area ratio may be 5% to 30%, and may be 5% to 20%.

[0030] The term "embossed fused portion" refers to a site where parts of a plurality of fibers are heat-fused (in other words, parts of a plurality of fibers are thermally bonded) and which is not fibrous. Specifically, in the embossed fused portion, the area of the fused site (i.e., the bonded site) is 0.1 mm ２ or more. Whether an embossed fused portion exists or not is determined by observing the surface or cross-section of the fiber aggregate to check whether an embossed fused portion (that is, a site where the area of the fused portion is 0.1 mm ２ or more) exists. The term "emboss area ratio of the nonwoven fabric" refers to the percentage ratio of the total area of the plurality of embossed fused portions to the surface area of the nonwoven fabric.

[0031] The nonwoven fabric according to the embodiment does not have to have embossed fused portions. Examples of processing methods that do not have embossed fused portions (also called "bonding processing") include calendering methods using commercially available flat calender rolls, water entanglement methods, needle punching methods, hot air bonding methods, ultrasonic bonding methods, and bonding methods using adhesives.

[0032] (1.1.1) Spunbond Nonwoven Fabric The nonwoven fabric according to the embodiment comprises a spunbond nonwoven fabric. The spunbond nonwoven fabric contains hollow fibers mainly composed of a thermoplastic resin.

[0033] The basis weight of SB nonwoven fabric is not particularly limited and can be appropriately selected depending on the application of the nonwoven fabric. The basis weight of a single layer of SB nonwoven fabric may be 1.0 gsm to 50.0 gsm, 1.0 gsm to 30.0 gsm, 1.0 gsm to 20.0 gsm, 2.0 gsm to 10.0 gsm, or 10.0 gsm to 15.0 gsm. When SB nonwoven fabric is used as a sanitary material, from the viewpoint of imparting flexibility and breathability to the SB nonwoven fabric, the basis weight of a single layer of SB nonwoven fabric may be 2.0 gsm to 20.0 gsm, 2.0 gsm to 10.0 gsm, or 2.0 gsm to 8.0 gsm. When a nonwoven fabric comprises multiple SB nonwoven fabrics, the basis weight of the SB nonwoven fabric in the nonwoven fabric is the basis weight obtained by adding up the basis weights of all the multiple SB nonwoven fabrics in the nonwoven fabric. When SB nonwoven fabric is used in industrial materials, from the viewpoint of tensile strength per basis weight, the basis weight of a single layer of SB nonwoven fabric may be 10.0 gsm to 50.0 gsm, 15.0 gsm to 30.0 gsm, 10.0 gsm to 150.0 gsm, or 10.0 gsm to 100.0 gsm. The method for measuring the basis weight of the SB nonwoven fabric is the same as the method described in the examples.

[0034] The thickness of the SB nonwoven fabric is not particularly limited and can be appropriately selected depending on the application of the nonwoven fabric. The thickness of the SB nonwoven fabric may be 0.1 mm to 2.0 mm, or 0.2 mm to 1.0 mm.

[0035] SB nonwoven fabric contains multiple hollow fibers. In addition to hollow fibers, SB nonwoven fabric may contain other fibers (for example, solid fibers, fibers that do not have a hollow portion in the fiber cross-section, and short fibers, etc.). Short fibers may be carded fibers, pulp fibers, cotton fibers, or bamboo fibers. The content of hollow fibers in SB nonwoven fabric can be adjusted as appropriate depending on the application. The content of hollow fibers may be 10% to 80% by mass, 80% to 100% by mass, or 90% to 100% by mass, based on the total mass of the SB nonwoven fabric. A hollow fiber content of 100% by mass is one of the preferred embodiments from the viewpoint of tensile strength per basis weight.

[0036] (1.1.1.1) Hollow Fibers The fiber diameter (i.e., outer diameter) of the hollow fibers is not particularly limited and is appropriately selected according to the application of the nonwoven fabric. The fiber diameter of the hollow fibers may be between 5.0 μm and 40.0 μm. From the viewpoint of spinning stability of the spunbond nonwoven fabric, it is preferable that the fiber diameter of the hollow fibers is 5.0 μm or more and less than 30.0 μm. From the viewpoint of having a good balance of spinning stability, uniformity of the nonwoven fabric, and tensile strength per basis weight, one preferred embodiment is one in which the fiber diameter of the hollow fibers is less than 30.0 μm and the coefficient of variation of the hollowness of the hollow fibers (hereinafter also referred to as "Cv of hollowness") is 14.0% or less. From the viewpoint of imparting flexibility to the nonwoven fabric, the fiber diameter of the hollow fibers may be 25.0 μm or less, or 5.0 μm or more. From the viewpoint of improving thread breakage and obtaining a desired mode, the fiber diameter of the hollow fibers is preferably 13.0 μm to 25.0 μm, more preferably 13.0 μm to 20.0 μm, even more preferably 13.0 μm to 18.5 μm, and may also be 14.6 μm to 18.5 μm. Note that the smaller the fiber diameter of the hollow fibers, the lower the bending rigidity of the SB nonwoven fabric. This improves the smoothness of the nonwoven fabric when it touches the skin. For this reason, SB nonwoven fabric is useful in sanitary materials and artificial leather. From the viewpoint of improving the breathability of the nonwoven fabric, the fiber diameter of the hollow fibers may be 20.0 μm to 50.0 μm. The thicker the fiber diameter of the hollow fibers, the better the abrasion resistance of the SB nonwoven fabric. For this reason, SB nonwoven fabric is useful in applications that suppress fluffing. The method for measuring the fiber diameter of the hollow fibers is the same as in the example.

[0037] The hollowness ratio of hollow fibers is not particularly limited and is appropriately selected depending on the application of the nonwoven fabric. The hollowness ratio of hollow fibers may be 1% to 50%. Preferably it is 1% to 40%, more preferably 1% to 30%, and even more preferably 1% to less than 30% from the viewpoint of having a good balance of spinning stability, uniformity of the nonwoven fabric, and tensile strength per basis weight, and may be 1% to 25%. The hollowness ratio of hollow fibers may be 5% to 50%, 5% to 40%, 5% to 30%, or 5% to less than 30%. The hollowness ratio of hollow fibers can be adjusted by the number of spinnerets. The higher the hollowness ratio of hollow fibers, the greater the effect of reducing environmental impact. From the viewpoint of suitability for applications where heat retention performance is required (e.g., hand warmers), the hollowness ratio of hollow fibers is preferably 5% or more, and more preferably 10% or more. The hollowness ratio of the hollow fiber is preferably 40% or less, more preferably 30% or less, from the viewpoint of the single-fiber strength of the hollow fiber. Depending on the application, the hollowness ratio of the hollow fiber may be 20% or less. The method for measuring the hollowness ratio of the hollow fiber is the same as that described in the examples.

[0038] The hollowness ratio Cv of the spunbond nonwoven fabric is not particularly limited and is appropriately selected depending on the application of the nonwoven fabric. Preferably, the coefficient of variation of the hollowness ratio of the hollow fibers in the spunbond nonwoven fabric is 14.0% or less.

[0039] The coefficient of variation (Cv) of the hollow fiber void ratio quantitatively represents the degree of variation in the void ratio in the fiber axis direction of the hollow fibers constituting the SB nonwoven fabric. A coefficient of variation of the hollow fiber void ratio that is closer to zero indicates that the shape of the hollow fibers contained in the SB nonwoven fabric is relatively uniform, that the void ratios of multiple hollow fibers are all approximately the same, and that there is less variation in the void ratio in the fiber cross-sectional direction of the hollow fiber. "Hollow ratio" refers to the ratio of the cross-sectional area of ​​the hollow part of a hollow fiber to the cross-sectional area defined by the outer diameter of the hollow fiber in a cross-section perpendicular to the fiber axis direction of a hollow fiber taken from the SB nonwoven fabric. The void ratio is expressed by the following formula (II). Formula (II): Hollow ratio [%] = (Cross-sectional area of ​​the hollow part of the hollow fiber / Cross-sectional area defined by the outer diameter of the hollow fiber) × 100 The method for measuring the Cv of the void ratio is the same as the method described in the examples.

[0040] A hollowness ratio (Cv) of 14.0% or less indicates that, in the multiple hollow fibers constituting the SB nonwoven fabric, the thickness of the walls constituting the hollow portion of the hollow fiber (hereinafter also referred to as "hollow portion walls") in the cross-section obtained by cutting the hollow fiber along a direction perpendicular to the fiber axis direction (hereinafter also simply referred to as "cross-section of the hollow fiber") is relatively uniform. Therefore, when the hollow fiber is pulled in the fiber axis direction, stress is less likely to concentrate in specific parts of the hollow fiber (especially parts where the hollow portion walls are thin) than in a configuration where the thickness of the hollow portion walls is uneven. Consequently, SB nonwoven fabrics containing hollow fibers with relatively uniform hollow portion wall thickness have superior spinning stability compared to SB nonwoven fabrics containing hollow fibers with uneven hollow portion wall thickness.

[0041] The hollowness ratio Cv of the hollow fibers is preferably 2.0% to 12.0%, more preferably 2.0% to less than 10.0%, even more preferably 2.0% to 9.3%, and even more preferably 2.0% to 8.7%, from the viewpoint of uniformity (visual inspection) of the nonwoven fabric and the basis weight Cv of the nonwoven fabric. The hollowness ratio Cv of the hollow fibers may be 5.0% or more, 6.0% or more, 7.0% or more, or 7.3% or more, and may be 9.0% or less. When SB nonwoven fabric containing hollow fibers is manufactured under conditions of a single-hole discharge rate of 0.55 g / min or more (high-speed manufacturing conditions), fiber cracking may occur depending on the manufacturing conditions, and the resulting hollowness ratio Cv of the hollow fibers may exceed 14.0%. Generally, when fiber cracking occurs, the strength of the fiber decreases. In other words, the single-fiber strength of conventional hollow fibers under high-speed manufacturing conditions was less than 19.0 mN / denier. This disclosure reveals that the hollow fiber ratio Cv can be reduced to 14.0% or less by the manufacturing method described later, and that the single-fiber strength can be improved compared to conventional methods. In other words, when the hollow fiber ratio Cv is within the above numerical range and the single-fiber strength is within a predetermined numerical range, the uniformity of the nonwoven fabric tends to increase.

[0042] Methods for adjusting the hollow fiber void ratio Cv to 14.0% or less include, for example, the type of thermoplastic resin, viscosity, melt flow rate, melting point, hollow ratio, fiber diameter, and the manufacturing method of the nonwoven fabric according to the embodiment described later (single-hole discharge amount, take-up speed, etc.).

[0043] The value represented by the following formula (I) (hereinafter also referred to as "Cv of the cross-sectional area of ​​the hollow fiber") is not particularly limited and is appropriately selected depending on the application of the nonwoven fabric. From the viewpoint of nonwoven fabric uniformity (mode), the Cv of the cross-sectional area of ​​the hollow fiber is 200% ３ ~250% ３ Preferably, 200% ３ ~235% ３ It is more preferable that the spinning stability and nonwoven fabric uniformity (mode) be 200% ３ ~227% ３ It is even more preferable that this is the case. Formula (I): (Coefficient of variation of the fiber diameter of the hollow fiber) ２ × Coefficient of variation of the hollowness ratio of the hollow fiber

[0044] The cross-sectional area Cv of a hollow fiber can be considered to quantitatively represent the degree of variation in the area of ​​the hollow part wall in the cross-section of the hollow fiber (hereinafter also referred to as "cross-sectional area of ​​the hollow fiber") in the fiber axis direction of the hollow fiber constituting the SB nonwoven fabric. A Cv of the cross-sectional area of ​​a hollow fiber that is closer to 0 indicates that there is less variation in the cross-sectional area of ​​the hollow fiber in the fiber axis direction.

[0045] The cross-sectional area (Cv) of the hollow fiber is 250% ３ If the following conditions are met, the single-fiber strength of the hollow fiber is equal to the cross-sectional area Cv of the hollow fiber at 250% ３ It tends to be superior to the super-structure. The cross-sectional area Cv of the hollow fiber is 250%. ３ The following conditions result in fewer extremely fine weak points that serve as the starting point for fiber splitting in hollow fibers, thereby improving spinning stability. Even under high-speed manufacturing conditions, SB nonwoven fabrics containing such hollow fibers can maintain the uniformity of the nonwoven fabric. As a result, the tensile strength per basis weight of the nonwoven fabric falls within the desired numerical range.

[0046] The cross-sectional area (Cv) of hollow fibers produced by spin-ray lamination is 200%. ３ When the above is achieved, the process capability index becomes appropriate, and there is a tendency for highly efficient commercial production of SB nonwoven fabric to be possible. From the viewpoint of improving spinning stability such as yarn sway and yarn breakage, and improving the uniformity of the nonwoven fabric in terms of mode and basis weight Cv, the cross-sectional area Cv of the hollow fibers should be 200%. ３ ~250% ３ In which the hollowness ratio Cv is 2.0% to 8.7%, one preferred embodiment is present. The method for measuring the cross-sectional area Cv of the hollow fiber is the same as in the example.

[0047] The cross-sectional area Cv of the hollow fiber is increased by 200% ３ ~250% ３ Methods for adjusting the properties include, for example, the type of thermoplastic resin, viscosity, melt flow rate, melting point, hollowness ratio, fiber diameter, and the manufacturing method of the nonwoven fabric according to the embodiment described later (single-hole discharge volume, take-up speed, etc.).

[0048] The cross-sectional shape of the hollow fiber may be approximately circular, or it may be irregular (e.g., elliptical, C-shaped, and dumbbell-shaped). The cross-sectional shape of the hollow portion of the hollow fiber may be approximately circular, or it may be irregular (e.g., elliptical and cross-shaped). The number of hollow portions contained in the hollow fiber may be one or multiple. In the cross-section of the hollow fiber, the center of gravity of the axis of the hollow portion may be the same as (concentric with) the center of gravity of the hollow fiber, or it may be different (eccentric). From the viewpoint of increasing the strength of the single filament, one preferred embodiment is that both the shape of the hollow fiber and the shape of the hollow portion of the hollow fiber are approximately circular.

[0049] (1.1.1.2) Material of Hollow Fibers Hollow fibers mainly consist of thermoplastic resin. Hollow fibers may consist of thermoplastic resin. The raw material for hollow fibers is the thermoplastic resin composition described later.

[0050] (1.1.1.2.1) Thermoplastic resins Examples of thermoplastic resins include olefin polymers, polyesters (e.g., polyethylene terephthalate and polybutylene terephthalate), polyamides (e.g., nylon-6 and nylon-66), polyvinyl chloride, polyimide, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl alcohol copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-acrylic acid ester-carbon monoxide copolymer, polyacrylonitrile, polycarbonate, polystyrene, polyphenylene sulfide, and biodegradable resins (e.g., polylactic acid and polyhydroxyalkanoates, polybutylene succinate, polybutylene succinate adipate, and polybutylene adipate terephthalate). Thermoplastic resins may be used individually or in combination of at least two types.

[0051] The content of thermoplastic resin relative to the total amount of hollow fibers may be 80% to 100% by mass, 90% to 100% by mass, or 98% to 100% by mass.

[0052] The thermoplastic resin may contain an olefin polymer, or may contain only an olefin polymer. The olefin polymer may be used alone, or in combination of two or more types.

[0053] The melt flow rate (hereinafter referred to as "MFR") of the olefin polymer is not particularly limited and may be between 1 g / 10 min and 100 g / 10 min, or between 15 g / 10 min and 80 g / 10 min. From the viewpoint of high-speed production of hollow fibers, the MFR of the olefin polymer may be between 15 g / 10 min and 70 g / 10 min, between 15 g / 10 min and less than 60 g / 10 min, between 20 g / 10 min and less than 60 g / 10 min, between 20 g / 10 min and 70 g / 10 min, or between 30 g / 10 min and 70 g / 10 min. From the viewpoint of having a good balance of spinning stability, uniformity of the nonwoven fabric, and tensile strength per basis weight, the MFR of the olefin polymer is preferably 30 g / 10 min to 70 g / 10 min, more preferably 45 g / 10 min to 70 g / 10 min, and even more preferably 45 g / 10 min to 60 g / 10 min. From the viewpoint of improving the uniformity of the nonwoven fabric and reducing yarn sway, the MFR of the olefin polymer is preferably 15 g / 10 min to 58 g / 10 min, more preferably 30 g / 10 min to 58 g / 10 min. The method for measuring the MFR of the olefin polymer is in accordance with ASTM D-1238, and the measurement conditions are 230°C and a load of 2160 g. When the thermoplastic resin contains at least two types of olefin polymers, "MFR of the olefin polymer" refers to the MFR of the thermoplastic resin containing at least two types of olefin polymers.

[0054] The thermoplastic resin is made of an olefin polymer, and the melt flow rate of the olefin polymer is preferably 15 g / 10 min to 80 g / 10 min. The melt flow rate is a measured value obtained in accordance with ASTM D-1238, under conditions of 230°C and a load of 2.16 kg.

[0055] Examples of olefin polymers include propylene polymers and polyolefins (excluding propylene polymers). Propylene polymers and polyolefins (excluding propylene polymers) may be used individually or in combination of at least two types. For example, the mixture may contain 70 parts propylene polymer and 30 parts polyolefin. The preferred embodiment of the melt flow rate of the propylene polymer is the same as that of the olefin polymer.

[0056] Polyolefins (excluding propylene-based polymers) are α-olefins alone or copolymers. α-olefins are α-olefins having 2 or more carbon atoms (excluding 3 carbon atoms), preferably including homopolymers of α-olefins having 2 to 8 carbon atoms (excluding 3 carbon atoms), and more preferably homopolymers of α-olefins having 2 to 8 carbon atoms (excluding 3 carbon atoms). Examples of α-olefins include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Examples of polyolefins (excluding propylene-based polymers) include polyethylene (ethylene homopolymer), 1-butene polymers, and poly4-methyl-1-pentene.

[0057] The thermoplastic resin (e.g., propylene polymer) may be derived from biomass-based raw materials. Biomass-derived raw materials are carbon-neutral materials. Therefore, the environmental burden in the manufacture of spunbond nonwoven fabrics can be reduced. Known monomers can be used as raw materials for biomass-derived thermoplastic resins. The thermoplastic polymer used as a raw material in this disclosure may include a thermoplastic polymer obtained by recycling (so-called recycled polymer). "Recycled polymer" includes polymers obtained by recycling waste polymer products. Recycled polymers can be manufactured, for example, by the method described in DE102019127827 (A1). Recycled polymers may include markers that indicate that they were obtained by recycling.

[0058] (1.1.1.2.2) The plasticizer hollow fiber may or may not contain a plasticizer.

[0059] It is preferable that the hollow fibers contain a plasticizer. This reduces the swell generated when the molten thermoplastic resin composition is extruded from the nozzle, thereby improving spinning stability. The inclusion of a plasticizer in the hollow fibers is useful when an olefin polymer with a low MFR (for example, MFR: 15 g / 10 min to 80 g / 10 min) is used as the thermoplastic resin.

[0060] The plasticizer preferably contains a fatty acid amide having 15 to 22 carbon atoms. Examples of fatty acid amides having 15 to 22 carbon atoms include fatty acid monoamide compounds, fatty acid diamide compounds, saturated fatty acid monoamide compounds, and unsaturated fatty acid diamide compounds.

[0061] The "carbon count of a fatty acid amide" refers to the total number of carbon atoms in the molecule. The carbon atoms in the -CONH group that makes up the amide are also included in the carbon count of the fatty acid amide.

[0062] The number of carbon atoms in the fatty acid amide is more preferably 18 to 22. Examples of fatty acid amides with 15 to 22 carbon atoms include palmitic acid amide (16 carbon atoms), stearic acid amide (18 carbon atoms), oleic acid amide (18 carbon atoms), and erucic acid amide (22 carbon atoms).

[0063] If the hollow fibers contain a plasticizer, the proportion of the plasticizer and the content of the thermoplastic resin may be within the following ranges. The content of the plasticizer relative to the total mass of the hollow fibers may be 0.1% to 5.0% by mass, 0.1% to 3.0% by mass, 0.1% to 1.0% by mass, or 0.1% to 0.5% by mass, from the viewpoint of tensile strength per basis weight. The content of the thermoplastic resin relative to the total mass of the hollow fibers may be preferably 95.0% to 99.9% by mass, 99.0% to 99.9% by mass, or 99.5% to 100.0% by mass, from the viewpoint of tensile strength per basis weight.

[0064] (1.1.1.2.3) Additive hollow fibers may contain additives other than plasticizers, or may not contain additives, as long as they do not impair the purpose of this disclosure. Examples of additives include antioxidants, heat stabilizers, weather stabilizers, antistatic agents, slip agents, antifogging agents, lubricants, dyes, pigments (e.g., titanium dioxide), natural oils, synthetic oils, waxes, and hydrophilic agents. The content of additives may be equivalent to that of the plasticizers mentioned above. Examples of hydrophilic agents include surfactants. Hydrophilic agents may be known compounds. Compounds may be individual compounds or mixtures thereof. Examples of compounds include polyoxyalkylene alkyl ethers, polyoxyalkylene fatty acid esters, polyoxyethylene polyhydric alcohol fatty acid esters, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyglycerin fatty acid esters, fatty acid alkanolamides, sulfonate-type surfactants, sulfate-type surfactants, carboxylate-type surfactants, phosphate-type surfactants, polyethylene ether-modified silicones, polyether-modified silicones, polyorganosiloxanes, and polyethylene glycol.

[0065] The fiber diameter of the hollow fiber is 10.0 μm or more and less than 30.0 μm, the hollowness ratio of the hollow fiber is 5% to 40%, and the cross-sectional area Cv of the hollow fiber is 200%. ３ 250% ３ The following is more preferable: This results in a nonwoven fabric that possesses tensile strength per unit weight and uniformity, as well as excellent spinning stability.

[0066] (1.1.2) Other nonwoven fabrics The nonwoven fabric according to the embodiment further comprises at least one component of another nonwoven fabric and film, which is different from the spunbond nonwoven fabric, and the other nonwoven fabric may be arranged on at least one main surface of the spunbond nonwoven fabric.

[0067] Hereinafter, nonwoven fabrics that further contain components will also be referred to as "laminated nonwoven fabrics."

[0068] (1.1.2.1) Other nonwoven fabrics Other nonwoven fabrics may be appropriately selected depending on the application of the laminated nonwoven fabric, for example. Other nonwoven fabrics may be SB nonwoven fabrics that do not have the same basis weight, fiber diameter, fiber shape, hollow fiber content, etc. Examples include MB nonwoven fabrics, wet nonwoven fabrics, water-entangled nonwoven fabrics, dry nonwoven fabrics, dry pulp nonwoven fabrics, airlaid nonwoven fabrics, flash-spun nonwoven fabrics, tow-opened nonwoven fabrics, needle-punched nonwoven fabrics, and cellulose fiber nonwoven fabrics.

[0069] When the laminated nonwoven fabric is used as an industrial material, it is a preferred embodiment that the laminated nonwoven fabric has an MS structure, SS structure, SMS structure, SSMS structure, SMSS structure, or SMMS structure. The basis weight of the laminated nonwoven fabric with an SMS structure or SMMS structure is adjusted according to the application and may be between 10 gsm and 1500 gsm. The basis weight of the laminated nonwoven fabric with an SMS structure or SMMS structure may be between 0.5 gsm and 200 gsm, between 0.5 gsm and 150 gsm, or between 0.7 gsm and 100 gsm.

[0070] The laminated nonwoven fabric may contain MB nonwoven fabric.

[0071] The basis weight of the MB nonwoven fabric is not particularly limited and is appropriately selected depending on the application of the nonwoven fabric. The basis weight of the MB nonwoven fabric may be 0.3 gsm to 5.0 gsm, 0.5 gsm to 3.0 gsm, or 0.5 gsm to 2.0 gsm. The method for measuring the basis weight of the MB nonwoven fabric is the same as that described in the examples.

[0072] The average fiber diameter of the MB nonwoven fabric is not particularly limited and is appropriately selected depending on the application of the nonwoven fabric. The average fiber diameter of the MB nonwoven fabric may be 0.2 μm to 5.0 μm. The average fiber diameter of the MB nonwoven fabric may be the arithmetic mean of the measured values ​​obtained by measuring the fiber diameter (μm) of 30 fibers of the MB nonwoven fabric using a scanning electron microscope (manufacturer: Hitachi, Ltd., model name: SU3500) at a magnification of 500x or 1000x.

[0073] The material of the MB nonwoven fabric may be the same as that exemplified for the material of the hollow fiber. The material of the MB nonwoven fabric may be the same as that of the hollow fiber, or it may be different from that of the hollow fiber. The MB nonwoven fabric may contain a homopolymer of α-olefin.

[0074] (1.1.2.2) Film The nonwoven fabric of the present disclosure may be laminated with a film. Examples of films include films that are impermeable to liquids and permeable to vapors, and films that are impermeable to vapors. Films that are impermeable to liquids and permeable to vapors are breathable. Breathable films may be microporous films or monolithic films.

[0075] Examples of films include thermoplastic synthetic resins commonly used in agriculture, etc. (e.g., polyethylene resins, polypropylene resins, polyurethane resins, and polyvinyl chloride resins). The film may be single-layer or multi-layer. The film may be colored or uncolored. The film may be a permeable film (i.e., a perforated film) or a non-permeable film.

[0076] The film may be bonded to the nonwoven fabric by an adhesive layer. The adhesive layer is formed by an adhesive. The adhesive is not particularly limited and includes, for example, olefin-based adhesives, vinyl-based adhesives, styrene-based adhesives, (meth)acrylic-based adhesives, polyester-based adhesives, urethane-based adhesives, and urethane-based adhesives. The adhesive may be a known adhesive. These adhesives may be used individually or in combination of two or more.

[0077] (1.2) Textile products The textile products according to the embodiment include nonwoven fabrics according to the embodiment.

[0078] As a result of having the above-described structure, the textile product exhibits excellent mechanical strength (e.g., MD tensile strength), reduces wear due to continuous use, and improves tear resistance compared to hollow fibers other than those specified in this disclosure. In addition, hollow fibers allow for a reduction in the amount of thermoplastic resin used compared to solid fibers of the same fiber diameter. As a result, the nonwoven fabric has sufficient mechanical strength even at relatively low basis weights, thereby reducing the environmental impact.

[0079] Textile products include sanitary products and industrial materials. Details about sanitary products will be discussed later. Industrial materials include, for example, agricultural covering materials (e.g., open-field cultivation sheets, tunnel cultivation sheets, greenhouse cultivation sheets, direct covering sheets, and seedbed sheets), clothing (e.g., interlining and adhesive interlining), construction (e.g., roofing materials and tufted carpet base materials), civil engineering (e.g., drain materials and filter materials), vehicles (e.g., car interiors, car parts, seat cushion base materials, and sound-absorbing materials), hygiene (e.g., first-aid supplies and cleaning supplies), interiors (e.g., carpets, furniture components, fixtures, wall coverings, and decorative items), bedding (e.g., futon bags, pillowcases, and sheets), leather (e.g., base fabrics for artificial leather and synthetic leather), lifestyle-related materials (e.g., clothing, padding retainers, storage items, packaging materials, and bags), and industrial materials (e.g., filter material support members). Industrial materials include abrasives, oil absorbent mats, piping ducts, paper felt, cushioning materials, concrete formwork drain materials, water drainage materials, insulation materials, soundproofing materials, cushioning materials, vibration damping materials, marine materials (e.g., interior finishes, parts, seat cushion substrates, and sound-absorbing materials), wipes (e.g., cleaning sheets and decorative sheets), electrical materials (e.g., electrical insulation materials for printed circuit boards, electromagnetic shielding materials, electromagnetic absorption materials, noise absorption sheets, noise suppression sheets, wire clamping tapes, and battery separators), and product substrates (e.g., substrates for fiber-reinforced plastics and printing substrates). Examples include substrates for synthetic paper, substrates for electrostatic recording devices, substrates for adhesive tapes, substrates for thermal transfer sheets, and substrates for radiation shielding mats, etc.), materials for office automation equipment (e.g., floppy disk liners and floppy disk packaging materials, etc.), materials for audiovisual equipment (e.g., speaker diaphragms and sound-absorbing panels, etc.), rolls (e.g., buff rolls, liquid-squeezing rolls and oil-coating rolls, etc.), equipment components (e.g., V-belts, conveyor belts and timing belts, etc.), and materials for musical instruments (e.g., piano key cushions and hammer rails, etc.).

[0080] The nonwoven fabric of the textile product may be a single-layer nonwoven fabric or a laminated nonwoven fabric. The textile product may be a laminate of a single-layer nonwoven fabric and a film. Examples of films include those similar to those exemplified for other nonwoven fabrics.

[0081] (1.3) Sanitary products The sanitary products according to the embodiment include a nonwoven fabric according to the embodiment.

[0082] Because the sanitary products according to the embodiment have the above-described structure, they tend to have excellent mechanical strength (e.g., MD tensile strength) and excellent fuzz resistance, and can improve tear resistance compared to hollow fibers other than those specified in this disclosure. Hollow fibers can reduce the amount of thermoplastic resin used compared to solid fibers of the same fiber diameter. As a result, the basis weight of the nonwoven fabric can be reduced, thereby reducing the environmental impact.

[0083] Examples of hygiene products include absorbent items (e.g., disposable diapers, disposable pants, sanitary napkins, incontinence pads, and pet sheets), medical hygiene materials (e.g., bandages, medical gowns, medical drapes, sterile sheets, medical gauze, towels, sheets, heat packs, cell culture sheets, and compresses), cosmetic products (e.g., face masks and puffs), and masks (e.g., industrial masks and sanitary masks).

[0084] (1.4) Method for Manufacturing Nonwoven Fabric The method for manufacturing nonwoven fabric according to the embodiment is a method for manufacturing nonwoven fabric according to the embodiment. The manufacturing method includes producing the spunbond nonwoven fabric by spin-ray lamination (hereinafter also referred to as the "spin-ray lamination step"). In the spin-ray lamination, the single-hole discharge rate of the molten thermoplastic resin composition discharged from the nozzle (hereinafter also referred to as the "single-hole discharge rate") is 0.55 g / min to 1.01 g / min, and the take-up rate of the hollow fibers discharged from the nozzle is 2000 m / min to 7500 m / min. The thermoplastic resin composition includes the thermoplastic resin. The hollow fibers consist of the thermoplastic resin composition. In the case of a spinning hole 120 consisting of multiple slots, the single-hole discharge rate is determined by considering the amount discharged from all slots.

[0085] In this disclosure, "take-up speed" refers to the cross-sectional area (m²) of the narrow passage 16a in a closed spunbond apparatus (see Figure 1) that cools the filament (i.e., hollow fiber) extruded from a nozzle with cooling air. ２ ) Flow rate of cooling air per unit Nm ３ This indicates the speed in meters per minute. In other words, the draw speed indicates the speed of the cooling air in the narrow section 16a of the extension section 16.

[0086] In the high-speed production of spunbond nonwoven fabrics containing hollow fibers, conventional manufacturing methods have made it difficult to continuously produce SB nonwoven fabrics containing hollow fibers.

[0087] The method for manufacturing nonwoven fabric according to this embodiment has an optimal configuration to solve the above problem. For example, even under conditions where hollow fibers are manufactured at high speed, it is possible to control the occurrence of thread breakage and manufacture a nonwoven fabric containing hollow fibers that is excellent in uniformity and tensile strength per basis weight. This is presumed to be mainly due to the first and second reasons.

[0088] Furthermore, the problem tends to become more apparent with low-basis-weight nonwoven fabrics of less than 20 gsm. In the manufacturing process of nonwoven fabrics, the lower the basis weight of the resulting nonwoven fabric, the fewer fibers per unit area of ​​the SB web and the higher the conveying speed. Generally, nonwoven fabrics with a low fiber count tend to be non-uniform and are prone to uneven lamination on the screen. In this disclosure, even with a low fiber count, the uniformity of the nonwoven fabric can be improved by appropriately distributing hollow fibers, in which thread breakage is suppressed, in both the planar and thickness directions of the nonwoven fabric.

[0089] The first reason is that, under conditions of relatively high manufacturing speed (e.g., single-hole discharge rate: 0.55 g / min or more), it is possible to suppress disturbances in the uniformity of multiple hollow fibers when the molten thermoplastic resin composition is discharged from the nozzle, and reduce the effect of low molecular weight components of the thermoplastic resin adhering to the nozzle. The second reason is that in large-scale equipment where the single-hole discharge rate is 0.55 g / min or more and the take-up speed is 2000 m / min to 7500 m / min, the cooling air can be supplied more stably, so the molten thermoplastic resin composition (i.e., hollow fibers) discharged from the nozzle tends to be pulled relatively uniformly and collected on the screen. As a result, the uniformity of each hollow fiber is increased, the uniformity of the SB web is improved (in other words, the uniformity of the lamination of multiple hollow fibers on the screen is improved), and the uniformity of the nonwoven fabric containing the hollow fibers can be improved.

[0090] (1.4.1) The method for manufacturing a nonwoven fabric according to the spin-ray lamination process embodiment includes a spin-ray lamination process and may further include known processes as needed.

[0091] In the spin-ray lamination process, the spunbond nonwoven fabric is produced by spin-ray lamination.

[0092] The spinray lamination process is typically carried out using known spinray nonwoven fabric manufacturing equipment.

[0093] The outlet setting temperature of the extruder that melts the thermoplastic resin composition discharged from the nozzle (hereinafter also referred to as the "molding temperature") is not particularly limited and is set appropriately depending on the type of thermoplastic resin, etc. The "outlet setting temperature" refers to the operating temperature closest to the nozzle among a plurality of operating temperatures set in the extruder. From the viewpoint of spinning stability, the molding temperature may be 200°C or higher, 220°C or higher, 230°C or higher, 235°C or higher, or 245°C or higher, and from the viewpoint of suppressing deterioration of the thermoplastic resin, it may be 280°C or lower, 250°C or lower, 245°C or lower, or 235°C or lower.

[0094] In the spin-ray lamination described above, the outlet setting temperature of the extruder that melts the thermoplastic resin composition discharged from the nozzle (i.e., the molding temperature) is preferably 230°C to 250°C, more preferably 230°C to 245°C, and even more preferably 230°C to 240°C. If the molding temperature is 230°C or higher, the fluidity of the molten thermoplastic resin composition decreases, which can suppress spinning defects (e.g., yarn breakage, yarn wobble, etc.). If the molding temperature is 250°C or lower, spinning defects caused by thermal decomposition of the thermoplastic resin and the adhesion of low molecular weight components to the nozzle can be suppressed.

[0095] The single-hole discharge rate is 0.55 g / min to 1.01 g / min. If the single-hole discharge rate is 0.55 g / min or higher, the heat content of the molten thermoplastic resin composition will not decrease relatively easily even under conditions where the molding temperature is 250°C or lower. Therefore, the occurrence of spinning defects due to a decrease in spinnability can be improved. If the single-hole discharge rate is 1.01 g / min or lower, insufficient cooling of hollow fibers can be suppressed, and the tensile strength per basis weight can be improved. From the viewpoint of spinning stability and uniformity of the nonwoven fabric, the single-hole discharge rate is preferably greater than 0.60 g / min and 1.01 g / min or less, more preferably 0.62 g / min or more and 1.01 g / min or less, and even more preferably 0.68 g / min or more and 1.01 g / min or less. From the viewpoint of spinning stability, the single-hole discharge rate is preferably 0.62 or more and 0.96 g / min or less, more preferably 0.68 or more and 0.96 g / min or less. In spunbond nonwoven fabrics containing hollow fibers, improving the basis weight (Cv) of the nonwoven fabric is a challenge. However, even under faster manufacturing conditions (for example, single-hole discharge rate: 0.76 g / min to 0.96 g / min), it is possible to manufacture nonwoven fabrics with excellent uniformity.

[0096] The draw speed is 2000 m / min to 7500 m / min, preferably 4600 m / min to 7200 m / min, and more preferably 4900 m / min to 7200 m / min. If the draw speed is 2000 m / min or higher, the spinning stability is excellent, and the desired mode and desired basis weight Cv can be obtained. If the draw speed is 7500 m / min or lower, yarn sway and yarn breakage can be reduced. The draw speed may be 4000 m / min or higher, 4600 m / min or higher, 4900 m / min or higher, 5000 m / min or higher, 6300 m / min or higher, or 7200 m / min or higher, and may be 7200 m / min or lower, 6300 m / min or lower, or 5000 m / min or lower. From the viewpoint of improving the mode or basis weight Cv, and reducing yarn sway and breakage, a combination of manufacturing conditions in which the single-hole discharge rate is 0.55 g / min to 1.01 g / min and the take-up rate is 4600 m / min to 7200 m / min is one of the preferred embodiments.

[0097] The temperature of the cooling air used to cool the hollow fibers is not particularly limited and may be between 5°C and 50°C, or between 10°C and 40°C.

[0098] The spinning speed is not particularly limited and is adjusted as appropriate depending on the type of thermoplastic resin, etc. "Spinning speed" refers to the linear velocity (m / min) of the yarn when the molten thermoplastic resin composition extruded from the spinneret is formed and stretched as a continuous filament in the spunbond method.

[0099] The spinning speed can be calculated using the following formula (III): Formula (III): Spinning speed = Single-hole discharge rate (g / min) × 9000 / Fineness [d] In formula (III), the fineness [d] can be determined from the following formula (IV) using the average of the measured outer diameter and the average of the calculated hollowness ratio: Formula (IV): Fineness = π × (Average outer diameter [μm] ÷ 2 ÷ 10000) ２ × (100 - Hollowness [%)) ÷ 100 × 0.91 × 900000 In equation (IV), "0.91" is the density of polypropylene (g / cm³). ３). If the thermoplastic resin is not polypropylene, the fineness is calculated using the density of the thermoplastic resin. For solid fibers, the fineness [d] is calculated by setting the average value of the hollowness ratio to 0.

[0100] The spinning speed may be 2500 m / min or more, 3000 m / min or more, 3200 m / min or more, 3900 m / min or more, 4700 m / min or more, 4900 m / min or more, or 5500 m / min or more, 6000 m / min or more, and may be 6300 m / min or less, 5500 m / min or less, 4900 m / min or less, 4700 m / min or less, or 3900 m / min or less. From the viewpoint of improving the mode or basis weight Cv, and reducing yarn sway and breakage, the spinning speed is preferably 3000 m / min to 7000 m / min, more preferably 3200 m / min to 6500 m / min, and even more preferably 4000 m / min to 6500 m / min.

[0101] (1.4.2) An Example of a Method for Manufacturing SB Nonwoven Fabric Hereinafter, an example of a method for manufacturing SB nonwoven fabric will be described in detail with reference to Figures 1 and 2. Figure 1 is a schematic diagram showing a sealed SB nonwoven fabric manufacturing apparatus according to an embodiment. In the sealed SB nonwoven fabric manufacturing apparatus, a plurality of continuous fiber groups (i.e., a plurality of hollow fibers) extruded from a spinneret (spinning hole) for hollow fibers are stretched in a sealed space while being cooled with cooling air. The sealed SB nonwoven fabric manufacturing apparatus is an example of a hollow fiber manufacturing apparatus. The hollow fibers according to the embodiment can be manufactured not only in a sealed SB nonwoven fabric manufacturing apparatus, but also in an open SB nonwoven fabric manufacturing apparatus or a general-purpose SB nonwoven fabric manufacturing apparatus.

[0102] The method for manufacturing the SB nonwoven fabric of this embodiment is carried out using the sealed SB nonwoven fabric manufacturing apparatus 100 shown in Figure 1. The method for manufacturing the SB nonwoven fabric includes a spin-lay lamination process (i.e., a melting process, a spinning process, a cooling and stretching process, a collection process, and a conveying process), and an embossing process. The melting process, spinning process, cooling and stretching process, collection process, conveying process, and embossing process are carried out in this order.

[0103] (1.4.2.1) Manufacturing apparatus The sealed SB nonwoven fabric manufacturing apparatus 100 includes a spinning section 10, as shown in Figure 1. The spinning section 10 includes an extruder 11, a spinneret 12, a cooling chamber 13, a spinning air supply section 14, a spinning air supply section 15, and a stretching section 16.

[0104] The extruder 11 melts the thermoplastic resin composition and extrudes the molten thermoplastic resin composition into the spinneret 12.

[0105] The spinneret 12 spins the molten thermoplastic resin composition to form a continuous fiber group 1. The continuous fiber group 1 consists of a plurality of hollow fibers. The spinneret 12 is for hollow fibers. Specifically, the spinneret 12 forms the molten thermoplastic resin composition into a continuous fiber group. The spinneret 12 has a number of spinning holes 120. In the spinneret 12, as shown in Figure 2, the spinning hole 120 for producing a single hollow fiber has four slots 121A. The molten thermoplastic resin composition, which is the raw material for the hollow fiber, flows through the slots 121A. The hole shape of the slots 121A is the irregular shape shown in Figure 2. The slots 121A have a slot width W (see Figure 2).

[0106] In this embodiment, the spinning hole 120 for producing a single hollow fiber is the slot 121A shown in Figure 2, but this disclosure is not limited thereto. In this disclosure, the spinning hole 120 for producing a single hollow fiber may be any known spinning hole for producing hollow fibers.

[0107] The cooling chamber 13 cools the continuous fiber group 1 spun from the spinning hole of the spinneret 12. The spinning air supply unit 14 and the spinning air supply unit 15 supply spinning air A into the cooling chamber 13 and the drawing unit 16.

[0108] In the stretching section 16, the continuous fiber group 1 is stretched by spinning air A. The stretching section 16 has a narrow section 16a and a cylindrical section 16b. The cylindrical section 16b is formed at the lower end (i.e., the screen 21 side) of the narrow section 16a in the vertical direction (i.e., the direction of gravity). The narrow section 16a is narrow. The cylindrical section 16b is cylindrical. The hollow part of the cylindrical section 16b widens downwards, as shown in Figure 1. The suction unit 22 collects the continuous fiber group 1 on the screen 21.

[0109] The suction unit 22 is positioned below the collection surface of the screen 21. Bonding processes such as embossing are then applied.

[0110] (1.4.2.2) Melting process In the melting process, the thermoplastic resin composition is melted and kneaded using the extruder 11, and the molten thermoplastic resin composition is extruded from the extruder 11.

[0111] The molding temperature of the thermoplastic resin composition is the same as that exemplified as the molding temperature for the spinray lamination process.

[0112] (1.4.2.3) Spinning Process In the spinning process, the molten thermoplastic resin composition is extruded from the spinning hole of the spinneret 12 using the spinneret 12. This forms a continuous fiber group 1 consisting of multiple hollow fibers.

[0113] The shape of the spinning holes in the spinneret 12 is not particularly limited, and can be used in combination with the slot shape, slot width W, and slot length described above. The number of slots can be 2 to 15, depending on the desired hollowness ratio.

[0114] The temperature of the spinneret 12 is equivalent to that exemplified as the molding temperature in the spinray lamination process.

[0115] (1.4.2.4) Cooling and stretching process In the cooling and stretching process, the continuous fiber group 1 is cooled and stretched by spinning air A. Specifically, spinning air A is supplied from the spinning air supply unit 14 and the spinning air supply unit 15 to the cooling chamber 13 and the stretching unit 16. This cools the continuous fiber group 1 extruded from the spinning hole of the spinneret 12 in the cooling chamber 13. Next, the cooled continuous fiber group 1 is introduced into the stretching unit 16 located downstream of the cooling chamber 13. The continuous fiber group 1 introduced into the stretching unit 16 is stretched by increasing the speed of the spinning air in the narrow passage 16a. The continuous fiber group 1 that has passed through the cylindrical section 16b is dispersed and collected on the screen 21. The dispersed continuous fiber group 1 is efficiently collected on the screen 21 by the suction unit 22. This forms the SB web 2.

[0116] The temperature of the spinning air A supplied from the spinning air supply unit 14 and the spinning air supply unit 15 is not particularly limited as long as it is at the temperature at which the thermoplastic resin solidifies. The temperature of the spinning air A is preferably 5°C to 50°C, more preferably 10°C to 40°C.

[0117] (1.4.2.5) Conveying Process In the conveying process, the SB webs 2 stacked on the screen 21 are conveyed.

[0118] The conveying method may be a publicly known method using conveying rollers.

[0119] The spinning speed can be similar to that exemplified in the spin-ray lamination process.

[0120] (1.4.2.6) Embossing Process In the embossing process, the SB web 2 is embossed. This causes the hollow fibers contained in the SB web 2 to bond together, resulting in the acquisition of SB nonwoven fabric.

[0121] "Embossing" refers to a process in which the SB web is sandwiched between an embossing roll and a flat roll, and some of the multiple fibers contained in the SB web are heat-pressed onto it. The embossing roll has multiple protrusions arranged in a regular pattern on its surface. The embossing roll transfers the shape of the top surfaces of the multiple protrusions to some of the multiple fibers contained in the SB web. As a result, the embossing roll forms multiple embossed areas on the SB web arranged in a regular pattern. The ratio of the area of ​​the multiple protrusions on the embossing roll to the surface area of ​​the embossing roll (hereinafter also referred to as the "embossing area ratio") is appropriately selected according to the application of the SB nonwoven fabric. The embossing area ratio of the embossing roll is the same as the embossing area ratio of the SB nonwoven fabric described above.

[0122] The operating temperature of the embossing roll (hereinafter also referred to as the "embossing temperature") can be set appropriately depending on the application. For applications requiring flexibility, the embossing temperature is preferably (melting point of the thermoplastic resin composition - 30°C) to (melting point of the thermoplastic resin composition + 20°C), more preferably (melting point of the thermoplastic resin composition - 30°C) to (melting point of the thermoplastic resin composition + 10°C), and even more preferably (melting point of the thermoplastic resin composition - 30°C) to the melting point of the thermoplastic resin composition. If the embossing temperature is between (melting point of the thermoplastic resin composition - 30°C) and (melting point of the thermoplastic resin composition + 20°C), the multiple hollow fibers in the embossed area will be sufficiently welded together.

[0123] The operating pressure of the embossing roll (hereinafter also referred to as "embossing pressure") can be set appropriately depending on the application. For applications requiring flexibility, the embossing pressure may be 20 N / mm to 80 N / mm. To ensure sufficient welding of multiple hollow fibers in the embossed area, the embossing pressure may be 60 N / mm to 150 N / mm.

[0124] Before performing the embossing process, the SB web 2 may be compacted using a nip roll.

[0125] In the manufacturing method of the SB nonwoven fabric according to this embodiment, the uniformity of the multiple hollow fibers and the uniformity of the lamination of the multiple hollow fibers on the screen can be improved by adjusting the molding temperature of the extruder 11, the single-hole discharge amount of the spinning holes of the spinneret 12, the spinning air speed of the spinning air supply unit 14, and the spinning air speed of the spinning air supply unit 15. As a result, it is possible to control the occurrence of yarn breakage and manufacture an SB nonwoven fabric containing hollow fibers that is excellent in uniformity and tensile strength per basis weight.

[0126] In this embodiment, the following embodiments of the method for manufacturing SB nonwoven fabric are all preferred in terms of high-speed productivity and uniformity and tensile strength of the nonwoven fabric.

[0127] Preferably, the single-hole discharge rate is 0.55 g / min to 1.01 g / min, the take-up speed is 2000 m / min to 7500 m / min, and the basis weight of the nonwoven fabric is 5.0 gsm to 20.0 gsm. This allows for more stable production of nonwoven fabric.

[0128] Preferably, the single-hole discharge rate is 0.55 g / min to 1.01 g / min, the basis weight of the nonwoven fabric is 5.0 gsm to 20.0 gsm, the fiber diameter of the hollow fibers is 5.0 μm to 20.0 μm, and the mode of the nonwoven fabric is 150 or higher. Preferably, the single-hole discharge rate is 0.55 g / min to 1.01 g / min, the basis weight of the nonwoven fabric is 5.0 gsm to 20.0 gsm, the fiber diameter of the hollow fibers is 5.0 μm to 20.0 μm, and the basis weight Cv of the nonwoven fabric is 7.4% or less. This allows for more stable production of nonwoven fabrics.

[0129] (2) Modified Forms (2.1) The modified form of the nonwoven fabric (i.e., hollow nonwoven fabric) is a nonwoven fabric having a spunbond nonwoven fabric (i.e., SB nonwoven fabric). The spunbond nonwoven fabric contains hollow fibers mainly composed of thermoplastic resin. The coefficient of variation of the basis weight of the nonwoven fabric (i.e., basis weight Cv) is 7.4% or less. The value expressed by the following formula (I) in the spunbond nonwoven fabric (i.e., Cv of the cross-sectional area of ​​the hollow fibers) is 200% ３ 250% ３ The following is the formula (I): (Coefficient of variation of the fiber diameter of the hollow fiber) ２ × Coefficient of variation of the hollowness ratio of the hollow fiber

[0130] In the modified version, the nonwoven fabric has the above-described structure and therefore contains hollow fibers (i.e., the nonwoven fabric in the modified version is lightweight), and is excellent in uniformity (visual inspection), uniformity of the nonwoven fabric in relation to basis weight Cv, and tensile strength per basis weight. When the basis weight Cv is 7.4% or less, the uniformity (visual inspection) and uniformity of the nonwoven fabric in relation to basis weight Cv are excellent. The Cv of the cross-sectional area of ​​the hollow fibers is 250% ３ If the following conditions are met, the single-fiber strength of the hollow fiber is equal to the cross-sectional area Cv of the hollow fiber at 250% ３ It tends to be superior to the super-structure. The cross-sectional area Cv of the hollow fiber is 250%. ３The following conditions result in fewer extremely fine weak points that serve as the starting point for fiber splitting in hollow fibers. As a result, spinning stability is excellent. Nonwoven fabrics containing such hollow fibers exhibit less variation in basis weight and superior uniformity (visual) and mode, due to the even distribution of hollow fibers in both the planar and thickness directions of the nonwoven fabric. As a result, the tensile strength per basis weight of the nonwoven fabric falls within the desired numerical range. The Cv of the cross-sectional area of ​​hollow fibers produced by spinray lamination is 200%. ３ Under these conditions, the process capability index becomes appropriate, and there is a tendency for highly efficient commercial production of nonwoven fabrics to be possible. In other words, even under high-speed manufacturing conditions, highly homogeneous hollow nonwoven fabrics can be obtained, and nonwoven fabrics with excellent uniformity (visual inspection), uniformity (mode), and tensile strength per basis weight can be obtained.

[0131] In the modified nonwoven fabric, instead of the mode in the grayscale image of the nonwoven fabric being 150 or higher, the basis weight Cv is 7.4% or lower, and the cross-sectional area Cv of the hollow fibers is 200%. ３ 250% ３ Except for the requirement that the following conditions be met, the nonwoven fabric is the same as that according to the embodiment, and the details described in the embodiment are also the same in the modified examples.

[0132] In a modified example, the tensile strength in the flow direction (MD) per basis weight of the nonwoven fabric is preferably 1.00 (N / 25mm) / gsm to 2.00 (N / 25mm) / gsm. This results in a nonwoven fabric with less variation in basis weight, and superior uniformity and spinning stability.

[0133] In the modified example, the coefficient of variation of the hollowness ratio of the nonwoven fabric (i.e., hollowness ratio Cv) is preferably 14.0% or less. If the hollowness ratio Cv is 14.0% or less, there is an excellent balance between spinning stability, uniformity of the nonwoven fabric, and tensile strength per basis weight. In the modified example, from the viewpoint of improving spinning stability such as yarn sway and yarn breakage, and improving the uniformity of the nonwoven fabric in relation to the mode and basis weight Cv, the cross-sectional area Cv of the hollow fibers is 200% ３ ~250% ３In which case, an embodiment in which the hollow ratio Cv is 2% to 8.7% is one of the preferred embodiments.

[0134] In the modified example, it is preferable that the mode (i.e., most frequent value) in the grayscale image of the nonwoven fabric is 150 or higher. If the mode of the nonwoven fabric containing hollow fibers is 150 or higher, the uniformity of the nonwoven fabric is improved. In addition, the tensile strength per basis weight of the nonwoven fabric is improved.

[0135] In a modified example, the thermoplastic resin is made of an olefin polymer, and the melt flow rate of the olefin polymer is preferably 15 g / 10 min to 80 g / 10 min. The melt flow rate is a measured value obtained in accordance with ASTM D-1238, under conditions of 230°C and a load of 2.16 kg.

[0136] In a modified example, the hollow fibers preferably contain a plasticizer. This reduces the swell generated when the molten thermoplastic resin composition is extruded from the nozzle, thereby improving spinning stability. The inclusion of a plasticizer in the hollow fibers is useful when an olefin polymer with a low MFR (for example, MFR: 15 g / 10 min to 58 g / 10 min) is used as the thermoplastic resin.

[0137] In the modified example, the basis weight of the nonwoven fabric is preferably 5.0 gsm to 20.0 gsm. This results in excellent cost performance and superior softness of the nonwoven fabric.

[0138] The modified nonwoven fabric further comprises at least one component of another nonwoven fabric and / or film, which is different from the spunbond nonwoven fabric, and it is preferable that the other nonwoven fabric is arranged on at least one main surface of the spunbond nonwoven fabric.

[0139] (2.2) Textile products relating to the modified textile products include nonwoven fabric relating to the modified textile products.

[0140] The modified textile product is the same as the modified textile product, except that the nonwoven fabric in the embodiment is changed to the modified nonwoven fabric.

[0141] (2.3) Sanitary products The sanitary products relating to the modified versions of this disclosure include nonwoven fabric relating to the modified versions.

[0142] The modified sanitary product is the same as the sanitary product according to the embodiment, except that the nonwoven fabric in the embodiment is changed to the modified nonwoven fabric.

[0143] (2.4) The method for manufacturing a nonwoven fabric according to the example of a change in the method for manufacturing a nonwoven fabric is a method for manufacturing a nonwoven fabric according to a modified example. The manufacturing method includes producing the spunbond nonwoven fabric by spin-ray lamination (i.e., a spin-ray lamination step). In the spin-ray lamination, the single-hole discharge rate of the molten thermoplastic resin composition discharged from the nozzle is 0.55 g / min to 1.01 g / min, and the take-up rate of the hollow fibers discharged from the nozzle is 2000 m / min to 7500 m / min. The thermoplastic resin composition includes the thermoplastic resin. The hollow fibers consist of the thermoplastic resin composition.

[0144] Because the modified method for manufacturing nonwoven fabric has the above configuration, it is possible to control the occurrence of thread breakage and manufacture a nonwoven fabric with excellent uniformity and tensile strength per unit weight, even under conditions where hollow fibers are manufactured at high speed.

[0145] The method for manufacturing the nonwoven fabric according to the modified example is the same as the method for manufacturing the nonwoven fabric according to the embodiment, except that the nonwoven fabric in the embodiment is replaced with the nonwoven fabric according to the modified example. The description of the modified example can be found by referring to the description of the embodiment.

[0146] In a modified example, in the spin-ray lamination, the outlet temperature of the extruder used to melt the thermoplastic resin composition (i.e., the molding temperature) is preferably 230°C to 250°C. If the molding temperature is 230°C or higher, the fluidity of the molten thermoplastic resin composition decreases, which can suppress the occurrence of spinning defects (e.g., yarn breakage, yarn wobble, etc.). If the molding temperature is 250°C or lower, thermal decomposition of the thermoplastic resin occurs, and low molecular weight components adhere to the nozzle, which can suppress the occurrence of spinning defects.

[0147] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to the following examples. The materials, amounts used, proportions, and processing procedures shown in the following examples can be modified as appropriate, as long as they do not deviate from the spirit of the present disclosure.

[0148] [1] Measurement Method [1.1] Mode in Grayscale Image of Nonwoven Fabric The mode in the grayscale image of nonwoven fabric refers to the value measured and calculated by the following method: (i) A sample measuring 250 mm (flow direction (MD)) x 200 mm (width direction (CD)) was cut from the nonwoven fabric. (ii) The sample was placed on black drawing paper (L value: 24.2). The "L value" is an index indicating lightness in the CIE L*a*b* color system. The L value is a scale where black is 0 and white is 100. A digital image (image file format: BMP format) of the sample placed on black drawing paper was captured using a high-resolution scanner (manufacturer: Seiko Epson Corporation, model number: GT-X980, resolution: 6400 dpi, size: 3 inch x 4 inch, gradation: grayscale setting). (iii) From the digital image (image file format: BMP format), a 1.5 inch x 2 inch area (hereinafter also referred to as the "evaluation area") was extracted from the entire area of ​​the sample and converted into a general digital image file (format: grayscale, gradation: 256 gradations) (hereinafter also referred to as the "grayscale image"). Using a Python program, the gradation was determined for each pixel (resolution: 6400 dpi) contained in the evaluation area of ​​the grayscale image. A histogram was created with the gradation of pixels on the vertical axis and the number of pixels on the horizontal axis, and the most frequent gradation of the entire grayscale image, excluding gradations of 251 or higher, was determined. The obtained most frequent gradation was defined as the "mode value in the grayscale image of the nonwoven fabric". The reason for excluding gradations of 251 or higher when determining the most frequent gradation was to eliminate the effect of overexposure during image acquisition of the sample (i.e., the nonwoven fabric). Image processing was performed using a Python program, but it can also be done using commonly available image analysis software (for example, ImageJ 1.32S created by WayneRasband). Figure 3 shows the program code for the image analysis software "ImageJ 1.32S" used to calculate the mode in a grayscale image of a nonwoven fabric.

[0149] [1.2] Fiber diameter, hollowness ratio, and Cv of hollowness of hollow fibers Fiber samples were taken as follows to measure the fiber diameter, hollowness ratio, Cv of hollowness ratio, and Cv of cross-sectional area of ​​hollow fibers. Using tweezers, 10 hollow fibers (length: approximately 10 mm) were randomly selected from the SB nonwoven fabric so as not to stretch the hollow fibers.

[0150] The hollow fibers to be measured were embedded in epoxy resin, and then, using a microtome, ten arbitrary points were cut along the fiber axis in the unembossed area of ​​the hollow fiber to obtain ten sample pieces. The test pieces were observed using an optical microscope (manufacturer: Nikon Corporation, model number: ECLIPSE E-400). For each sample piece, the diameter of the circumscribed circle of the fiber cross-section was measured as the outer diameter, the diameter of the inscribed circle as the inner diameter, and the hollowness ratio were measured or calculated. This procedure was performed on 100 sample pieces. The average of the 100 outer diameter measurements was defined as the "fiber diameter of the hollow fiber." The standard deviation of the 100 outer diameter measurements was multiplied by 100 and divided by the average value of the outer diameter to obtain the value defined as the "Cv of the fiber diameter of the hollow fiber." The average of the 100 hollowness ratio measurements was defined as the "hollowness ratio of the hollow fiber." The value obtained by multiplying the standard deviation of 100 measured values ​​of hollow fiber density by 100 and dividing by the average value of the hollow fiber density was defined as the "hollow fiber density Cv" of the hollow fiber. Here, "hollow fiber density" refers to the ratio of the cross-sectional area of ​​the hollow part of the hollow fiber to the cross-sectional area defined by the outer diameter of the hollow fiber in a cross section perpendicular to the fiber axis direction of the hollow fiber taken from the SB nonwoven fabric. The hollow fiber density is expressed by the following formula (II). Formula (II): Hollow fiber density [%] = (Cross-sectional area of ​​the hollow part of the hollow fiber / Cross-sectional area defined by the outer diameter of the hollow fiber) × 100 Note that for the "fiber diameter of the hollow fiber", if the cross-section of the hollow fiber is not a perfect circle (approximately circular), the area is measured and the diameter value obtained by converting it to a perfect circle is adopted.

[0151] [1.3] Basis Weight [gsm] Ten test specimens measuring 100 mm (flow direction (MD)) × 100 mm (width direction (CD)) were taken from each of the SB nonwoven fabric and MB nonwoven fabric. The test specimens were taken from the center of the width direction (CD) of the SB nonwoven fabric and MB nonwoven fabric. Then, the mass [g] of the test specimens was measured using a top-loading electronic balance (manufactured by Kensei Kogyo Co., Ltd.) under conditions of 20°C and 50% relative humidity. From the average mass of the SB nonwoven fabric test specimens, 1 m ２ The value obtained by converting it to mass per unit [g] was defined as the "basis weight of SB nonwoven fabric". From the average mass of the MB nonwoven fabric test specimens, 1 m ２ The value obtained by converting it to mass per unit [g] was defined as the "basis weight of MB nonwoven fabric". If the nonwoven fabric had an SMS structure, the value obtained by adding the "basis weight of SB nonwoven fabric" and the "basis weight of MB nonwoven fabric" was defined as the "basis weight of the nonwoven fabric". If the nonwoven fabric had an S structure, the "basis weight of SB nonwoven fabric" was defined as the "basis weight of the nonwoven fabric". If the nonwoven fabric had an SSMS structure, the value obtained by adding the "basis weight of SB nonwoven fabric" and the "basis weight of MB nonwoven fabric" was defined as the "basis weight of the nonwoven fabric".

[0152] [1.4] Basis Weight Cv A first test specimen was taken from the nonwoven fabric. The size of the first test specimen was 200 mm (flow direction (MD)) × 100 mm (width direction (CD)). Specifically, the nonwoven fabric was cut at positions 50 mm away from the center in the width direction (CD) in both the positive and negative directions of the width direction (CD), and the first test specimen was taken so that the length in the width direction (CD) was 100 mm. The first test specimen (size: 100 mm × 200 mm) was divided into 10 equal parts of 10 mm each in the width direction (CD), and 10 second test specimens were obtained. The mass of each of the 10 second test specimens was measured and converted to basis weight. The average value and standard deviation of the basis weight of the 10 second test specimens were calculated. The value obtained by multiplying the standard deviation by 100 and dividing by the average value of the basis weight was defined as "Basis Weight Cv". An acceptable basis weight Cv is 7.4% or less.

[0153] [1.5] MD Tensile Strength [N / 25mm] and MD Tensile Strength per Basis Weight The MD tensile strength of the nonwoven fabric was measured in accordance with JIS L 1906 6.12.1 [Method A] (transitioned to JIS L 1913:2010, corresponding to ISO 9073-3:1989). Ten test specimens were taken from the nonwoven fabric. The size of the test specimens was 25 mm (width direction (CD)) × 200 mm (flow direction (MD)). The test specimens were taken from 10 arbitrary locations along the flow direction (MD) of the nonwoven fabric. Using a tensile testing machine, the test specimens were pulled in the flow direction (MD) with a chuck distance of 100 mm and a head speed of 100 mm / min, and the maximum tensile strength [N / 25mm] was determined. The average of the 10 maximum tensile strength measurements was defined as the "MD tensile strength". The value obtained by dividing the MD tensile strength by the basis weight of the nonwoven fabric was defined as the "MD tensile strength per basis weight."

[0154] [1.6] CD Tensile Strength [N / 25mm] Ten test specimens were taken from the nonwoven fabric. The size of the test specimens was 25 mm (flow direction (MD)) x 200 mm (width direction (CD)). The test specimens were taken from 10 arbitrary locations along the width direction (CD) of the nonwoven fabric. Using a tensile testing machine, the test specimens were pulled in the width direction (CD) with a chuck distance of 100 mm and a head speed of 100 mm / min, and the maximum tensile strength [N / 25mm] was determined. The average of the 10 maximum tensile strength measurements was defined as the "CD tensile strength".

[0155] [1.7] Spinning stability The nonwoven fabric was visually and sensorily evaluated by five skilled technicians. During spin-ray lamination, the oscillation and breakage of multiple hollow fibers discharged from the nozzle were visually observed for 20 minutes at a point 300 mm downstream from the bottom surface of the nozzle. Using the observation results, spinning stability was evaluated according to the following evaluation criteria. Acceptable spinning stability evaluation results are "A1", "B1", or "C1".

[0156] [1.7.1] Criteria for sensory evaluation A1: No hollow fiber movement or breakage was observed, and spinning was stable. B1: There was slight hollow fiber movement, but no hollow fiber breakage was observed, and spinning was stable. C1: There was hollow fiber movement, but no hollow fiber breakage was observed, and spinning was stable. D1: Hollow fiber movement was present, and hollow fiber breakage occurred.

[0157] The evaluation criteria for spinning stability can be expressed using a threshold value for the cross-sectional area (Cv) of the hollow fiber.

[0158] [1.7.2] Cv threshold of the cross-sectional area of ​​hollow fibers A2: 200% ３ ≤Cv of the cross-sectional area of ​​the hollow fiber ≤ 227% ３ B2: 227% ３ <Cv ≤ 250% of the cross-sectional area of ​​the hollow fiber ３ C2: 250% ３ <Cv of the cross-sectional area of ​​hollow fibers

[0159] [1.8] Uniformity of Nonwoven Fabric (Visual Inspection) The nonwoven fabric was visually inspected and sensory-evaluated by five skilled technicians. The nonwoven fabric was placed on the black drawing paper used for the mode evaluation, and its uniformity was evaluated according to the following evaluation criteria. An acceptable uniformity evaluation result is "A3", "B3", or "C3".

[0160] [1.8.1] Criteria for sensory evaluation A3: The nonwoven fabric had no unevenness between the white and black areas, and the color of the nonwoven fabric was very uniform. B3: The nonwoven fabric had no unevenness between the white and black areas, and the color of the nonwoven fabric was highly uniform. C3: The nonwoven fabric had no noticeable unevenness between the white and black areas, and the color of the nonwoven fabric was uniform. D3: The nonwoven fabric had noticeable unevenness between the white and black areas, and the color of the nonwoven fabric was poorly uniform.

[0161] Within the specified basis weight range, the color variations of the nonwoven fabric are thought to be primarily due to differences in the thickness of various parts of the nonwoven fabric. The black areas of the nonwoven fabric indicate areas where the nonwoven fabric is thinner than the white areas. The white areas of the nonwoven fabric indicate areas where the nonwoven fabric is relatively thicker than the black areas.

[0162] The uniformity of a nonwoven fabric can be expressed by the mode of the grayscale of the nonwoven fabric and the threshold value of the Cv of the nonwoven fabric's basis weight.

[0163] [1.8.2] Grayscale Mode Threshold A4: 170 ≤ Grayscale Mode B4: 164 ≤ Grayscale Mode < 170 C4: 150 ≤ Grayscale Mode < 164 D4: Grayscale Mode < 150

[0164] [1.8.3] Thresholds for the basis weight Cv of nonwoven fabrics A5++: 2.0% ≤ basis weight Cv of nonwoven fabrics < 4.4% A5+: 4.4% ≤ basis weight Cv of nonwoven fabrics ≤ 5.0% A5: 5.0% < basis weight Cv of nonwoven fabrics ≤ 7.4% B5: 7.4% < basis weight Cv of nonwoven fabrics

[0165] [2] Examples 1 to 11 and Comparative Examples 1 to 6 [2.1] The following products were prepared as raw materials.

[0166] [2.1.1] Thermoplastic resins: • hPP1: Homopolypropylene (melting point: 160°C, MFR (temperature 230°C, load 2.16 kg): 36 g / 10 min) • hPP2: Homopolypropylene (melting point: 160°C, MFR (temperature 230°C, load 2.16 kg): 55 g / 10 min) • rPP3: Random polypropylene (melting point: 148°C, MFR (temperature 230°C, load 2.16 kg): 25 g / 10 min) • hPP4: Homopolypropylene (melting point: 161°C, MFR (temperature 230°C, load 2.16 kg): 60 g / 10 min) • hPP5: Homopolypropylene (MFR (melting point 160°C, temperature 230°C, load 2.16 kg): 850 g / 10 min)

[0167] [2.1.2] Plasticizer: Erucic acid amide (melting point: 80°C)

[0168] [2.2] Example 1 Using the sealed SB nonwoven fabric manufacturing apparatus 100 shown in Figures 1 and 2, a nonwoven fabric having an SMS structure was produced as follows.

[0169] [2.2.1] Spunbond Web A thermoplastic resin composition was obtained by mixing 99.7 parts by mass of hPP1 and 0.3 parts by mass of plasticizer. Spin-lay lamination was performed using the thermoplastic resin composition. Specifically, the thermoplastic resin composition was melted using a 75 mmφ extruder 11. The molten hPP1 was introduced into a die having a plurality of spinnerets 12. The spinnerets 12 were for hollow fibers. The number of slots in the spinning holes 120 slots 121A was selected to be 2 to 6 in order to obtain the desired hollow fibers. The molding temperature of the extruder 11 was 230°C. The amount of molten thermoplastic resin composition introduced was adjusted so that the single-hole discharge rate of the spinneret 12 was 0.60 g / min. The hollow fibers discharged from the spinneret 12 were cooled with spinning air A and stretched to obtain hollow fibers. The temperature of the spinning air A was 20°C. The wind speed for the take-up was 4492 m / min. Multiple hollow fibers spun as described above were deposited on the screen 21 to form an SB web (hereinafter also referred to as "SB web (first layer)"). The spinning speed was 3130 m / min. The basis weight of the SB web (first layer) is shown in Table 1.

[0170] [2.2.2] Meltblown web Meltblown lamination was performed using hPP5. Specifically, hPP5 was melt-kneaded in an extruder at a molding temperature of 290°C, and the resulting molten material was introduced into a die having multiple spinneret nozzles and extruded from the die into a high-speed heated air stream. This formed an MB web (hereinafter also referred to as "MB web (second layer)") on top of the SB web (first layer). The average fiber diameter of the MB web (second layer) was 3.0 μm. The basis weight of the MB web (second layer) was 0.7 g / m ２ That was the case.

[0171] [2.2.3] Spunbond Web An SB web (hereinafter also referred to as "SB web (third layer)") was formed on an MB web (second layer) in the same manner as the manufacturing method for the SB web (first layer). This resulted in a laminated web with a three-layer structure.

[0172] [2.2.4] Embossing Next, the laminated web was embossed with an embossing roll (embossing area ratio: 18%, embossing temperature: 135°C, embossing pressure: 90 N / mm) to produce a nonwoven fabric.

[0173] [2.3] Examples 2-4, 6-9, 11 and Comparative Examples 1-6 Nonwoven fabrics were obtained in the same manner as in Example 1, except that the manufacturing conditions were changed to those shown in Table 1, and in Comparative Example 5, the spinneret 12 for hollow fibers was changed to a spinneret for solid fibers.

[0174] [2.4] Examples 5 and 10 [2.4.1] Except for changing the spunbond web manufacturing conditions to those shown in Table 1, the SB web was formed on the screen 21 in the same manner as the manufacturing method for the SB web (first layer) in Example 1.

[0175] [2.4.2] Except for changing the spunbond web manufacturing conditions to those shown in Table 1, the SB web was formed by depositing the material on top of the SB web (first layer) in the same manner as the manufacturing method for the SB web (first layer) in Example 1.

[0176] [2.4.3] Embossing Next, the SB web was embossed in the same manner as in Example 1 to produce a nonwoven fabric having an S structure.

[0177] [3] Results

[0178]

[0179]

[0180] In Tables 1 to 3, "concentric" refers to concentric hollow fibers.

[0181] In Comparative Examples 1 to 6, the mode in the grayscale image of the nonwoven fabric was not 150 or higher. The tensile strength in the flow direction (MD) per basis weight of the nonwoven fabric was not between 1.00 (N / 25mm) / gsm and 2.00 (N / 25mm) / gsm. The visual evaluation results of the uniformity of the nonwoven fabrics in Comparative Examples 1 to 6 were not "A3", "B3", or "C3". The basis weight Cv of the nonwoven fabric was not 7.4% or less. As a result, it was found that the nonwoven fabrics in Comparative Examples 1 to 6 were not "nonwoven fabrics containing hollow fibers that are excellent in uniformity and tensile strength per basis weight".

[0182] In Examples 1 to 11, the mode in the grayscale image of the nonwoven fabric was 150 or higher. The tensile strength in the flow direction (MD) per basis weight of the nonwoven fabric was 1.00 (N / 25mm) / gsm to 2.00 (N / 25mm) / gsm. The uniformity (visual) evaluation results of the nonwoven fabrics in Examples 1 to 11 were "A3", "B3", or "C3". The basis weight Cv of the nonwoven fabric was 7.4% or less. As a result, it was found that the nonwoven fabrics in Examples 1 to 11 are "nonwoven fabrics containing hollow fibers that are excellent in uniformity and tensile strength per basis weight".

[0183] The disclosure of Japanese Patent Application No. 2025-057236, filed on 28 March 2025, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A nonwoven fabric having a spunbond nonwoven fabric containing hollow fibers mainly composed of a thermoplastic resin, wherein the mode in a grayscale image of the nonwoven fabric is 150 or more, and the tensile strength in the flow direction (MD) per basis weight of the nonwoven fabric is 1.00 (N / 25 mm) / gsm to 2.00 (N / 25 mm) / gsm.

2. The nonwoven fabric according to claim 1, wherein the coefficient of variation of the hollowness ratio of the hollow fibers in the spunbond nonwoven fabric is 14.0% or less.

3. The value represented by the following formula (I) in the spunbond nonwoven fabric is 200% ３ ~250% ３ The nonwoven fabric according to claim 1. Formula (I): (Coefficient of variation of the fiber diameter of the hollow fibers) ２ × Coefficient of variation of the hollowness ratio of the hollow fiber 4. The nonwoven fabric according to claim 1, wherein the thermoplastic resin is made of an olefin polymer, the melt flow rate of the olefin polymer is 15 g / 10 min to 80 g / 10 min, and the melt flow rate is a measured value obtained in accordance with ASTM D-1238 under conditions of 230°C and a load of 2.16 kg.

5. The nonwoven fabric according to claim 1, wherein the hollow fibers contain a plasticizer.

6. The nonwoven fabric according to claim 1, wherein the basis weight of the nonwoven fabric is 5.0 gsm to 20.0 gsm.

7. The nonwoven fabric according to claim 1, further comprising at least one member of another nonwoven fabric and film different from the spunbond nonwoven fabric, wherein the member is disposed on at least one main surface of the spunbond nonwoven fabric.

8. A textile product comprising a nonwoven fabric according to any one of claims 1 to 7.

9. A sanitary product comprising the nonwoven fabric described in any one of claims 1 to 7.

10. A method for manufacturing a nonwoven fabric to produce the nonwoven fabric according to any one of claims 1 to 7, wherein the manufacturing method includes producing the spunbond nonwoven fabric by spin-ray lamination, wherein in the spin-ray lamination, the single-hole discharge rate of the molten thermoplastic resin composition discharged from the nozzle is 0.55 g / min to 1.01 g / min, and the take-up rate of the hollow fibers discharged from the nozzle is 2000 m / min to 7500 m / min, the thermoplastic resin composition comprises the thermoplastic resin, and the hollow fibers consist of the thermoplastic resin composition.

11. The method for producing a nonwoven fabric according to claim 10, wherein, in the spin-ray lamination, the outlet temperature set at the extruder for melting the thermoplastic resin composition is 230°C to 250°C.

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