Nonwoven fabric, manufacturing method thereof, and wiper

Abstract

To provide a method for producing a nonwoven fabric that hardly causes fuzzing and breakages and has an excellent dirt collecting property, and is suitable for being used as a wiper.SOLUTION: There is provided a method for producing a nonwoven fabric 100 comprising a cellulosic fiber and an adhesive fiber. The method for producing the nonwoven fabric 100 includes a bonding step of bonding fibers with each other by the adhesive fiber in a fiber web comprising the cellulosic fiber and the adhesive fiber, and an entangling step of entangling fibers with each other after the bonding step. The entangling step includes a partially entangling step in which a high entangled part 10 having a higher degree of entanglement of mutual fibers and a low entangled part 20 having a lower degree of entanglement of mutual fibers than that of the highly entangled part 10 are formed so that the high entangled part 10 and the low entangled part 20 are alternately arranged in a plain view and the low entangled part 20 has a width of 2 mm or more and 50 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to nonwoven fabrics and methods for making the same, as well as wipers including the nonwoven fabrics. [Background technology]

[0002] One application of nonwoven fabrics is wipers for wiping dirt off the human body or objects. Wipers have a wide variety of configurations. For example, Patent Document 1 proposes a composite sheet suitable for cleaning, in which protrusions made of nonwoven fabric are fixed in a ridge-like shape on a nonwoven fabric, and when viewed in a cross section of the composite sheet perpendicular to the ridges, at least some of the protrusions have a hook-shaped cross-sectional structure, and the protrusions having the hook-shaped cross-sectional structure continue for 3 to 20 cm along the ridges. Furthermore, Patent Document 2 proposes a nonwoven fabric for use as a wiping material in which the constituent fibers are entangled by needle punching, with the remaining portions being first entangled sections, and the constituent fibers at predetermined locations of the nonwoven fabric are further entangled to form second entangled sections, the first entangled sections and the second entangled sections being present in multiple rows spaced apart from each other, the first entangled sections having a relatively lower fiber density than the second entangled sections, and when observed from the cross section, the first entangled sections protrude beyond the second entangled sections onto at least one surface of the nonwoven fabric. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-212879 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-117095 Summary of the Invention [Problem to be solved by the invention]

[0004] To provide a method for producing a nonwoven fabric which, when used as a wiper, is resistant to fluffing or tearing due to the force applied when rubbing the body or an object to remove dirt or when attached to a jig, and has excellent dirt collection properties, and to provide a nonwoven fabric produced by the method. [Means for solving the problem]

[0005] In a first aspect, the present disclosure provides a method for producing a nonwoven fabric containing cellulosic fibers and adhesive fibers, the method comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, The present invention provides a method for producing a nonwoven fabric, which includes a partial entanglement step in which the entanglement step forms highly entangled sections, in which the degree of entanglement between fibers is higher, and low entangled sections, in which the degree of entanglement between fibers is lower than that of the highly entangled sections, so that the highly entangled sections and the low entangled sections are alternately arranged in a plan view and the width of the low entangled sections is 2 mm or more and 50 mm or less.

[0006] In a second aspect, the present disclosure provides a nonwoven fabric comprising a cellulosic fiber and an adhesive fiber, The adhesive fibers include bonded portions between each other and / or bonded portions between the adhesive fibers and the cellulosic fibers, The cellulose-based fibers include entangled portions between each other and / or entangled portions between the cellulose-based fibers and the adhesive fibers, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, The nonwoven fabric has a fluff shedding amount of 1.5 mg or more and 20 mg or less on at least one surface of the nonwoven fabric, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff.

[0007] In a third aspect, the present disclosure provides a wiper including the nonwoven fabric according to the second aspect.

[0008] In a fourth aspect, the present disclosure provides a method for producing a nonwoven fabric including a fiber layer containing cellulosic fibers and adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, the method comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a plan view and the less entangled parts have a width of 2 mm or more and 50 mm or less; a base sheet laminating step of laminating the base sheet on the fiber web to obtain a composite web, which is performed before or after the bonding step and before the entangling step; A method for producing a nonwoven fabric is provided.

[0009] In a fifth aspect, the present disclosure provides a nonwoven fabric including a fiber layer including a cellulosic fiber and an adhesive fiber, and a base sheet integrated with the fiber layer by entanglement of the fibers, The adhesive fibers include bonded portions between each other and / or bonded portions between the adhesive fibers and the cellulosic fibers, The cellulose-based fibers include entangled portions between each other and / or entangled portions between the cellulose-based fibers and the adhesive fibers, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, The nonwoven fabric has a fluff shedding amount of 1.5 mg or more and 20 mg or less on at least one surface of the nonwoven fabric, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff.

[0010] In a sixth aspect, the present disclosure provides a wiper including the nonwoven fabric according to the fifth aspect.

[0011] In a seventh aspect, the present disclosure provides a method for producing a nonwoven fabric containing adhesive fibers, comprising: In a fiber web containing the adhesive fibers, the method includes a bonding step of bonding fibers to each other with the adhesive fibers, and an entanglement step of entangling the fibers to each other after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a planar view, and the less entangled parts have a width of 2 mm or more and 50 mm or less. A method for producing a nonwoven fabric is provided.

[0012] In an eighth aspect, the present disclosure provides a method for producing a nonwoven fabric including a fiber layer containing adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, the method comprising: In a fiber web containing the adhesive fibers, the method includes a bonding step of bonding fibers to each other with the adhesive fibers, and an entanglement step of entangling the fibers to each other after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a plan view and the less entangled parts have a width of 2 mm or more and 50 mm or less; a base sheet laminating step of laminating the base sheet on the fiber web to obtain a composite web, which is performed before or after the bonding step and before the entangling step; A method for producing a nonwoven fabric is provided.

[0013] In a ninth aspect, the present disclosure provides a nonwoven fabric comprising adhesive fibers, The adhesive fibers include adhesive points between each other, The adhesive fibers include entangled portions, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, The nonwoven fabric has a fluff shedding amount of 1.5 mg or more and 20 mg or less on at least one surface of the nonwoven fabric, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff.

[0014] In a tenth aspect, the present disclosure provides a nonwoven fabric including a fiber layer containing adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, The adhesive fibers include adhesive points between each other, The adhesive fibers include entangled portions, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, The nonwoven fabric has a fluff shedding amount of 1.5 mg or more and 20 mg or less on at least one surface of the nonwoven fabric, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff.

[0015] In an eleventh aspect, the present disclosure provides a wiper including the nonwoven fabric according to the ninth or tenth aspect. [Effects of the Invention]

[0016] In the manufacturing method of the present disclosure, fibers are bonded together using adhesive fibers, and then the fiber web is subjected to an entanglement process including a partial entanglement process. As a result, the resulting nonwoven fabric is relatively bulky and has a relatively high degree of fiber freedom, particularly in the low entanglement regions, and exhibits relatively high strength due to the relatively strong entanglement of the fibers in the highly entangled regions. Furthermore, by bonding the fibers together, the resulting nonwoven fabric is less likely to fluff. A wiper including a nonwoven fabric obtained by the manufacturing method of the present disclosure is relatively bulky and exhibits excellent dirt collection ability in the low entanglement regions where the degree of fiber freedom is relatively high. In the highly entangled regions where the fibers are relatively strong, the strength of the wiper as a whole is ensured. Furthermore, due to the bonding of the fibers together, fluffing is less likely to occur. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a perspective view showing an example of a nonwoven fabric produced by carrying out a hydroentangling treatment using a nozzle 1) as a partial entangling step. [Figure 2] FIG. 1 is a perspective view showing an example of a nonwoven fabric produced by carrying out a hydroentangling treatment using a nozzle 2) as a partial entangling step. DETAILED DESCRIPTION OF THE INVENTION

[0018] (Background to the manufacturing method of the present disclosure) The present inventors have discovered that when a nonwoven fabric is used as a wiper, increasing the degree of freedom of the fibers in the nonwoven fabric and increasing the bulk of the nonwoven fabric improves its dirt collection ability. A common method for obtaining a bulky nonwoven fabric is to subject the fibers to a bonding treatment (e.g., hot air processing) without applying pressure using adhesive fibers. However, if the nonwoven fabric obtained by this method contains a high proportion of adhesive fibers, the fibers are bonded and fixed, reducing the degree of freedom of the fibers, resulting in insufficient dirt wiping and collection capabilities. The degree of freedom of the fibers in the nonwoven fabric can be increased by mixing non-adhesive fibers. However, non-adhesive fibers reduce the strength of the nonwoven fabric and are prone to causing fuzzing on the surface of the nonwoven fabric when rubbed against an object or the body, so mixing non-adhesive fibers tends to make it difficult to obtain a practical wiper.

[0019] Another known method for producing nonwoven fabrics is entangling fibers, as described in Patent Document 2. In nonwoven fabrics in which the fibers are entangled, the fibers are not bonded, allowing for a relatively high degree of freedom of the fibers, and adjusting the degree of entanglement can result in a flexible nonwoven fabric. However, if the degree of entanglement of the fibers is increased in order to improve the strength of the nonwoven fabric, the bulk of the nonwoven fabric decreases, resulting in a decrease in its ability to collect dirt.

[0020] Furthermore, nonwoven fabrics in which fibers are merely entangled are prone to fuzzing, and one method of preventing this is to mix adhesive fibers into the fiber web and then, after the fibers are entangled, adhere the fibers to each other with the adhesive fibers. However, in this case, the degree of freedom of the fibers inevitably decreases, further reducing the ability to wipe or collect dirt.

[0021] Therefore, the present inventors have investigated a method for producing a nonwoven fabric that achieves both bulkiness and high fiber flexibility. They produced a nonwoven fabric by subjecting a fiber web containing adhesive fibers, specifically a fiber web containing a mixture of adhesive fibers and non-adhesive cellulosic fibers, to a bonding step to fix the fibers to a certain extent, and then subjecting the fiber web to a partial entanglement step. As a result, they were able to obtain a nonwoven fabric that was bulkier, had a higher fiber flexibility, and was less prone to pilling than a nonwoven fabric produced by first performing the entanglement step and then the bonding step. The method for producing the nonwoven fabric of the present disclosure will be described below.

[0022] [Embodiment 1] A method for producing a nonwoven fabric according to a first embodiment of the present disclosure includes: A method for producing a nonwoven fabric comprising cellulosic fibers and adhesive fibers, comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled portions, in which the degree of entanglement between fibers is higher, and less entangled portions, in which the degree of entanglement between fibers is lower than that of the belt-like portions or the streak-like portions, so that the highly entangled portions and the less entangled portions are alternately arranged in a planar view, and the less entangled portions have a width of 2 mm or more and 50 mm or less; A method for manufacturing nonwoven fabric.

[0023] In this manufacturing method, a fibrous web containing cellulosic fibers and adhesive fibers is used, and therefore, the cellulosic fibers and adhesive fibers will be described first below.

[0024] (cellulosic fiber) "Cellulosic fibers" are also called cellulose fibers and generally refer to fibers made from cellulose. Cellulosic fibers include, for example: (1) Natural fibers derived from plants such as cotton, flax, flax, ramie, jute, banana, bamboo, kenaf, shell ginger, hemp, and kapok; (2) Regenerated fibers such as viscose-based rayon and polynosic rayon, cupra obtained by the cuprammonium method, and Tencel® and Lyocell® obtained by solvent spinning; (3) cellulose fibers obtained by melt spinning; and (4) Semi-synthetic fibers such as acetate fibers The type of cellulosic fiber is not particularly limited.

[0025] The fineness of the cellulosic fibers may be, for example, 0.6 dtex to 5.6 dtex, particularly 1.0 dtex to 4.4 dtex, and more particularly 1.4 dtex to 3.3 dtex. When the fineness of the cellulose-based fiber is within the above-mentioned range, the strength of the nonwoven fabric and the suppression of fluffing can be made appropriate, and the bulkiness of the nonwoven fabric is also good. The fineness of the cellulose-based fiber affects the entanglement of the fibers, and when the fineness of the cellulose-based fiber is within the above-mentioned range, the degree of entanglement is made appropriate. If the degree of entanglement is too high, the bulkiness of the nonwoven fabric may decrease, and if the degree of entanglement is too low, the strength may decrease and fluffing may occur significantly.

[0026] The fiber diameter of the cellulosic fibers may be, for example, 5 μm to 25 μm, particularly 8 μm to 20 μm, and more particularly 10 μm to 17 μm. When the fiber diameter of the cellulose-based fiber is within the above-mentioned range, the strength and fuzzing of the nonwoven fabric can be appropriately suppressed, and the bulkiness of the nonwoven fabric is also good. The fiber diameter of the cellulose-based fiber also affects the entanglement of the fibers, and when the fiber diameter of the cellulose-based fiber is within the above-mentioned range, the degree of entanglement is appropriate. If the degree of entanglement is too high, the bulkiness of the nonwoven fabric may decrease, and if the degree of entanglement is too low, the strength may decrease and fuzzing may occur significantly.

[0027] The fiber length of the cellulosic fibers may be, for example, 25 mm to 100 mm, particularly 30 mm to 70 mm, and more particularly 35 mm to 60 mm. When the fiber length of the cellulosic fiber is within the above range, the entanglement of the fiber is likely to be favorable. In particular, in the manufacturing method of this embodiment, when the fiber length is within the above range, a more appropriate number of bonded points can be formed on each fiber in the bonding step.

[0028] The cross section of the cellulosic fiber (transverse section, or cross section perpendicular to the length direction of the fiber) may be circular or noncircular. Examples of noncircular shapes include ellipse, Y-shape, X-shape, I-shape, multi-lobed shape, polygonal shape, star shape, and chrysanthemum shape. When the fiber cross section is circular, the adhesion area with the adhesive fiber is relatively small, allowing for greater flexibility in the fibers of the nonwoven fabric than when fibers with a noncircular shape are used. When the fiber cross section is noncircular, the adhesion area with the adhesive fiber is relatively large, allowing for greater suppression of fluffing in the nonwoven fabric and greater strength of the nonwoven fabric.

[0029] As the cellulosic fibers, chemical fibers such as regenerated fibers or semi-synthetic fibers may be used. The variations in fineness and / or fiber diameter, as well as fiber length, of chemical fibers are smaller than those of natural fibers, making it easier to adjust the degree of entanglement of the nonwoven fabric. Furthermore, regenerated fibers such as rayon and solvent-spun cellulose fibers have a good balance of softness and strength when wet, making it easier to achieve suitable softness and strength for the nonwoven fabric, and are therefore preferred. Furthermore, solvent-spun cellulose fibers have a relatively high single fiber strength, making them preferable in that they suppress fuzzing of the nonwoven fabric and improve the strength of the nonwoven fabric. The cellulosic fibers can be used alone or in combination.

[0030] The cellulosic fibers may be surface-treated to change the degree of hydrophilicity or hydrophobicity of the surface. The surface treatment is generally a treatment in which an oil agent (surfactant) is attached to the fiber surface. The degree of hydrophilicity or hydrophobicity of the surface of the cellulosic fibers can be evaluated using, for example, values ​​such as the sedimentation rate of the fibers. The surface treatment may be to increase the hydrophilicity of the surface (hydrophilization treatment) or to decrease the hydrophilicity of the surface (hydrophobization treatment).

[0031] The settling velocity (or settling time (seconds)) of the cellulosic fibers used in this embodiment may be, for example, 30 seconds or less, particularly 20 seconds or less, and more particularly 10 seconds or less. The smaller the settling velocity (or settling time) of the cellulosic fibers, the higher the entanglement of the cellulosic fibers tends to be.

[0032] The settling velocity of the fibers can be measured by the following method. 17 g of fiber is collected to measure the sedimentation rate. The collected fiber is opened (using a parallel carding machine) to form a carded web. 5 g of the carded web is weighed and packed into a cage (cylindrical, 5 cm diameter, 8 cm height, 3 g mass) made of copper wire (0.55 mm diameter). Next, prepare a thermostatic water bath, fill it with tap water, and set it to 25°C. Once the water temperature reaches 25°C, stop stirring the thermostatic water bath and begin measuring the sedimentation rate. Gently drop the basket filled with fibers using the procedure above from a position 1 cm above the water surface, and start the stopwatch as soon as the basket hits the water surface. The fibers gradually absorb water, and stop the stopwatch as soon as the 8 cm high basket completely sinks below the water surface. The sedimentation rate is the time from when the basket hits the water surface to when it sinks below the water surface, and the average of the two measurements is taken as the sedimentation rate of that fiber.

[0033] In the sedimentation rate measurement, if the basket does not sink below the water surface for 5 minutes or more, the fibers are deemed to be water-repellent. Water-repellent cellulosic fibers may be preferable in applications where the nonwoven fabric comes into contact with liquid. For example, in top sheets and second sheets for absorbent articles, water-repellent cellulosic fibers may be preferable because they facilitate the transfer of liquid to the absorbent body without excessively retaining the liquid within the sheet. When a nonwoven fabric has a laminated structure, using a laminated nonwoven fabric having a layer containing water-repellent cellulosic fibers and a layer containing non-water-repellent cellulosic fibers allows the nonwoven fabric to transfer or retain liquid effectively in applications such as sheets for absorbent articles and liquid-impregnated skin coverings impregnated with liquids such as cosmetics.

[0034] (adhesive fiber) Next, adhesive fibers will be described. The term "adhesive fiber" refers to a fiber that exhibits adhesiveness through a bonding process (e.g., thermal bonding process, electron beam irradiation, ultrasonic welding (ultrasonic welder), etc.) and can bond fibers together to form bonded areas, and is not particularly limited as long as the nonwoven fabric intended by the present disclosure can be obtained.

[0035] The adhesive fibers include, for example, synthetic fibers made of thermoplastic resin. Thermoplastic resins are not particularly limited and include, for example, polyester resins such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polylactic acid, polybutylene succinate, and copolymers thereof; polyolefin resins such as polypropylene, polyethylene (including high-density polyethylene, low-density polyethylene, and linear low-density polyethylene), polybutene-1, propylene copolymers primarily composed of propylene (including propylene-ethylene copolymers and propylene-butene-1-ethylene copolymers), ethylene-acrylic acid copolymers, and ethylene-vinyl acetate copolymers; polyamide resins such as nylon 6, nylon 12, and nylon 66; acrylic resins; engineering plastics such as polycarbonate, polyacetal, polystyrene, and cyclic polyolefins, as well as elastomers thereof. Synthetic fibers may be produced using one or more thermoplastic resins selected from these.

[0036] The synthetic fiber may be a single fiber made of one or more thermoplastic resins selected from the above, or may be a conjugate fiber made of two or more components (also called "sections"). In the conjugate fiber, each component may be made of a single thermoplastic resin, or may be a mixture of two or more thermoplastic resins. The conjugate fiber may be, for example, a sheath-core conjugate fiber, an islands-in-the-sea conjugate fiber, or a side-by-side conjugate fiber. The sheath-core conjugate fiber may be an eccentric sheath-core conjugate fiber in which the center of the core component does not coincide with the center of the sheath component in the fiber cross section, or a concentric sheath-core conjugate fiber in which the center of the core component coincides with the center of the sheath component in the fiber cross section.

[0037] Synthetic fibers, whether single or composite, may have a modified cross section. In the case of sheath-core and islands-in-sea composite fibers, the core and / or island components may have a modified cross section in the fiber cross section. When the synthetic fiber has a non-circular cross section, the cross section may be elliptical, polygonal, star-shaped, or a shape in which multiple projections are joined at their bases (for example, cloverleaf shape). In this embodiment, two or more synthetic fibers may be used in combination as the synthetic fibers.

[0038] When the synthetic fiber is a composite fiber, two or more components may be arranged so that the thermoplastic resin with a lower melting point forms part of the fiber surface. The thermoplastic resin with a low melting point (low-melting component) melts or softens when heat is applied during the process of producing a nonwoven fabric, becoming an adhesive component. The low-melting component contributes to the adhesion of fibers to each other or to other components, and can form adhesive sites. When the synthetic fiber is a composite fiber, the low-melting point component is preferably exposed over 40% or more of the circumferential length of the fiber in the cross section, more preferably over 50% or more, even more preferably over 60% or more, even more preferably over 80% or more, and particularly preferably over the entire circumferential length of the fiber.

[0039] In this embodiment, a nonwoven fabric is produced by performing an entanglement step after the bonding step. The proportion of the length of the low-melting point component of the adhesive fiber exposed on the circumferential surface of the fiber in the fiber cross section (hereinafter referred to as the "exposed length") affects the area of ​​the bondable region and also affects the degree to which adhesion between fibers is resolved in the entanglement step. When the exposed length of the low-melting point component of the adhesive fiber is within the above range, the area of ​​the bondable region becomes appropriate, and the number of bonded points can be made appropriate. Furthermore, by appropriately dissolving adhesion between fibers in the subsequent entanglement step, fuzzing can be further suppressed in the finally obtained nonwoven fabric, and its strength can be made sufficient. If the proportion of the exposed length is too small, the number of bonded points will be reduced, making the nonwoven fabric more susceptible to fuzzing or reducing the strength of the nonwoven fabric.

[0040] The adhesive component of the adhesive fiber may be a copolymer of an olefin and an unsaturated carboxylic acid or its derivative. Such a copolymer exhibits good adhesion to cellulosic fibers. Examples of unsaturated carboxylic acids include maleic acid, acrylic acid, methacrylic acid, fumaric acid, and itaconic acid. Examples of derivatives include anhydrides of unsaturated carboxylic acids, methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, 2-hydroxyethyl methacrylate, and dimethylaminoethyl methacrylate, as well as similar acrylic acid esters, glycidyl acrylate, glycidyl methacrylate, butenecarboxylic acid esters, allyl glycidyl ether, 3,4-epoxybutene, 5,6-epoxy-1-hexene, and vinylcyclohexene monoxide. An ethylene-acrylic acid copolymer, in which the olefin is ethylene and the unsaturated carboxylic acid or its derivative is acrylic acid or its derivative, is particularly preferred.

[0041] Combinations of thermoplastic resins that make up the composite fiber include, for example, combinations of polyolefin resins and polyester resins (polyolefin resin / polyester resin), such as polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate, and propylene copolymer / polyethylene terephthalate, as well as combinations of two types of polyolefin resins, such as polyethylene / polypropylene, propylene copolymer / polypropylene, and ethylene-acrylic acid copolymer / polypropylene, and combinations of two types of polyester resins with different melting points.

[0042] When the adhesive fiber is a sheath-core composite fiber in which a thermoplastic resin with a lower melting point constitutes the sheath portion, examples of core / sheath combinations include polyethylene terephthalate / polyethylene, polyethylene terephthalate / polypropylene, polyethylene terephthalate / propylene copolymer, polytrimethylene terephthalate / polyethylene, polybutylene terephthalate / polyethylene, polyethylene terephthalate / copolymer polyester (e.g., polyethylene terephthalate copolymerized with isophthalic acid), polypropylene / ethylene-acrylic acid copolymer, and polylactic acid / polybutylene succinate. These combinations can also be applied to composite fibers other than sheath-core composite fibers. Sheath-core composite fibers in which the sheath is polyethylene (e.g., high-density polyethylene, low-density polyethylene, or linear low-density polyethylene) or a copolymer polyester have the property that, when heat-treated at a temperature above the melting point of the thermoplastic resin constituting the sheath, the sheath melts or softens, bonding the fibers together and forming bonded areas.

[0043] The thermoplastic resins exemplified as constituent components of the single fiber or composite fiber may contain other components as long as they contain 50% by mass or more of the specifically specified thermoplastic resin. For example, in the combination of polyethylene / polyethylene terephthalate, the "polyethylene" may contain other thermoplastic resins and additives, etc., as long as it contains 50% by mass or more of polyethylene. This also applies to the examples below.

[0044] When the adhesive fiber is a core-sheath type composite fiber, the core-to-sheath composite ratio (volume ratio, core / sheath) may be, for example, 80 / 20 to 20 / 80, and particularly 60 / 40 to 40 / 60. When the core / sheath composite ratio is within this range, the adhesion between the fibers is adequate, resulting in a nonwoven fabric with adequate strength and reduced fuzzing. Furthermore, when the core / sheath composite ratio is within this range, excessive peeling at the bonded portions during the entangling process does not occur. Furthermore, when the core / sheath composite ratio is within this range, the core component easily maintains the fiber shape, allowing the nonwoven fabric to have appropriate strength.

[0045] Two or more adhesive fibers may be included. In this case, the melting points of the adhesive components of these fibers may be different from each other. For example, when two types of adhesive fibers are included, the difference in melting points of the adhesive components of these fibers may be 10°C or more and 40°C or less, particularly 15°C or more and 30°C or less.

[0046] The fineness of the adhesive fiber may be, for example, 1.0 dtex to 7.8 dtex, particularly 1.4 dtex to 6.7 dtex, and more particularly 2.2 dtex to 4.5 dtex. When the fineness of the adhesive fiber is within the above range, the resulting nonwoven fabric tends to have appropriate strength, reduced fluffing, and bulkiness.

[0047] The fiber diameter of the adhesive fiber may be, for example, 10 μm to 33 μm, particularly 12 μm to 30 μm, and more particularly 15 μm to 25 μm. When the fiber diameter of the adhesive fiber is within the above range, the resulting nonwoven fabric tends to have appropriate strength, reduced fluffing, and bulkiness.

[0048] The fiber length of the adhesive fiber may be, for example, 25 mm to 100 mm, particularly 30 mm to 70 mm, and more particularly 35 mm to 60 mm. When the fiber length of the adhesive fiber is within the above range, the entanglement of the fibers is likely to be favorable. In particular, in the manufacturing method of this embodiment, when the fiber length is within the above range, a more appropriate number of bonded points can be formed on one fiber in the bonding step.

[0049] The adhesive fibers may have three-dimensional crimps in the final nonwoven fabric. When the adhesive fibers have three-dimensional crimps, the resulting nonwoven fabric tends to be bulkier. Furthermore, when the adhesive fibers have three-dimensional crimps, it becomes easier to obtain a nonwoven fabric in which the bond intersection index A and bond intersection angle (the angle of the fiber bond intersections at either or both the upper and lower parts when the nonwoven fabric is divided into three equal parts in the thickness direction) fall within a specific range, as described below. In this specification, the term "three-dimensional crimps" is used to distinguish them from mechanical crimps, in which the crimp peaks (or peaks) are at acute angles. Three-dimensional crimps include, for example, crimps with curved peaks (wave-shaped crimps), crimps with spirally curved peaks (helical crimps), crimps that are a mixture of wave-shaped crimps and spiral crimps, and crimps that are a mixture of acute-angled mechanical crimps and at least one of wave-shaped crimps and spiral crimps. Alternatively, the adhesive fibers may have only mechanical crimp.

[0050] When the adhesive fiber is a conjugate fiber, it may be a visibly crimped conjugate fiber. The term "visibly crimped conjugate fiber" refers to a fiber that exhibits three-dimensional crimp at the fiber stage, and is different from a visibly crimped conjugate fiber that exhibits three-dimensional crimp upon heat treatment.

[0051] The adhesive fiber having 3D crimp may be an eccentric core-sheath type composite fiber. In this case, the eccentricity may be, for example, 5% to 50%, and particularly 7% to 30%. The "eccentricity" here is defined by the following formula: Eccentricity (%) = (distance between the center of the single fiber and the center of the core component) × 100 / (single fiber radius)

[0052] In this embodiment, the adhesive fiber does not necessarily include fibers derived from so-called splittable conjugate fibers. Splittable conjugate fibers have a cross-sectional structure in which at least one of the constituent components is divided into two or more parts in the fiber cross section, at least a portion of the constituent components is exposed on the fiber surface, and the exposed parts are continuously formed in the length direction of the fiber. Splittable conjugate fibers, for example, have wedge-shaped sections arranged in a chrysanthemum shape, or have each section arranged in a layered shape in the fiber cross section. Splittable conjugate fibers split one or more components (sections) due to an external force applied during the entanglement treatment, resulting in ultrafine fibers. When such splittable conjugate fibers are not included as adhesive fibers, the adhesion between fibers is good, and it is easy to achieve appropriate strength and reduced fuzzing in the nonwoven fabric. Furthermore, when splittable conjugate fibers are not included as adhesive fibers, it is easy to increase the bulk of the ridges when forming the less entangled portions into ridges.

[0053] (Preparation of fiber web) Next, the preparation of a fibrous web containing the above-mentioned cellulosic fibers and adhesive fibers will be described. The fibrous web is produced by mixing cellulosic fibers and adhesive fibers. The blend ratio of the cellulosic fibers to the adhesive fibers (cellulosic fibers:adhesive fibers) (mass ratio) may be, for example, 10:90 to 90:10, particularly 20:80 to 80:20, more particularly 20:80 to 60:40, even more particularly 20:80 to 55:45, even more particularly 20:80 to 45:55, and even more particularly 25:75 to 35:65. When the blend ratio of the cellulosic fibers to the adhesive fibers is within the above range, the resulting nonwoven fabric is bulky, while also easily achieving appropriate strength and reduced fuzzing.

[0054] Cellulosic fibers are used as non-adhesive fibers, providing a certain degree of freedom for the fibers in the nonwoven fabric. Furthermore, cellulosic fibers exhibit high entanglement properties, particularly when the entanglement process is carried out as a hydroentanglement process, and are well entangled even at low water pressure, thereby ensuring the strength of the nonwoven fabric. Therefore, if the proportion of cellulosic fibers is too low, the strength of the nonwoven fabric may decrease, or the nonwoven fabric may not exhibit good dirt collection properties when used as a wiper.

[0055] The adhesive fibers bond the fibers together, thereby ensuring the bulkiness of the resulting nonwoven fabric and suppressing fuzzing. As described below, in this embodiment, a fiber web with very weak fiber entanglement is first subjected to the bonding process, and the fiber web after the bonding process is in a relatively bulky state, with the fibers bonded together. When this fiber web is then subjected to the entanglement treatment, the bonded areas formed by the adhesive fibers resist bulk loss due to the entanglement treatment, compared to when the fiber web is directly subjected to the entanglement treatment, resulting in a bulky nonwoven fabric. Furthermore, the adhesive fibers also suppress fuzzing by fixing the fibers together. Therefore, if the proportion of adhesive fibers is too small, the nonwoven fabric may not be able to achieve good bulkiness. Furthermore, if the proportion of adhesive fibers is too small, the strength of the fiber web before the entanglement process may be reduced and it may become more elongated, resulting in insufficient processability of the fiber web. Furthermore, if the proportion of adhesive fibers is too small, fuzzing may be more likely to occur.

[0056] The fibrous web may contain fibers other than cellulosic fibers and adhesive fibers (hereinafter referred to as "other fibers"). The other fibers are not particularly limited, and include, for example, natural fibers that are not cellulosic fibers (e.g., wool, silk, etc.) and synthetic fibers that are not adhesive fibers (e.g., synthetic fibers that do not melt or soften when the adhesive component of the adhesive fiber is melted and do not exhibit adhesiveness).

[0057] The other fibers may be contained in an amount of 35% by mass or less, particularly 25% by mass or less, and more particularly 10% by mass or less, when the total amount of fibers constituting the fiber web is 100% by mass. In this embodiment, the fibrous web may contain no other fibers and may consist only of cellulosic fibers and adhesive fibers.

[0058] Alternatively, the fibrous web may be composed primarily of adhesive fibers and other fibers that are not cellulosic fibers, or may be composed solely of adhesive fibers. In such a fibrous web, the blend ratio of the other fibers to the adhesive fibers (other fibers:adhesive fibers) (mass ratio) may be, for example, 0:100 to 90:10, particularly 0:100 to 80:20, and more particularly 0:100 to 60:40. When the blend ratio of the other fibers to the adhesive fibers is within the above range, the resulting nonwoven fabric is bulky, while the nonwoven fabric is likely to have appropriate strength and reduced fuzzing. In addition to the other fibers and adhesive fibers, the fibrous web may contain cellulosic fibers, which may be present in a proportion of 10% by mass or less, when the total mass of the fibers constituting the fibrous web is taken as 100% by mass.

[0059] The fiber web can be produced by a known method. The form of the fiber web may be any form such as a parallel web, a cross web, a carded web such as a semi-random web or a random web, an air-laid web, or a wet-laid web. A parallel web form of the fiber web is preferred because it makes the surface of the nonwoven fabric smoother.

[0060] The fibrous web may be, for example, 10 g / m 2 ~150g / m 2 and in particular 15 g / m 2 ~120g / m 2 and more particularly 30 g / m 2 ~100g / m 2 and more particularly 40 g / m 2 ~80g / m 2The basis weight of the fiber web is approximately the same as the basis weight of the resulting nonwoven fabric, so if the basis weight of the fiber web is within the above range, a soft nonwoven fabric with excellent bulkiness and fuzz suppression can be obtained. If the basis weight is too small, it may be difficult to obtain a bulky nonwoven fabric, and if the basis weight is too large, the strength of the nonwoven fabric may decrease or fuzz may be more likely to occur.

[0061] The preparation of the fibrous webs may include, for example, separately preparing fibrous web A and fibrous web B. In this case, as described below, for example, fibrous web A may be subjected to a bonding process, and then fibrous web B may be laminated thereon, and the laminated two fibrous webs may be subjected to an entanglement process. When a nonwoven fabric is produced by this method, fibrous web A and fibrous web B may be identical. Alternatively, fibrous web A and fibrous web B may differ from each other in at least one of the types of cellulosic fibers and / or adhesive fibers, the ratio of cellulosic fibers to adhesive fibers, the shape, and the basis weight. Alternatively, fibrous web B may contain only cellulosic fibers without containing adhesive fibers. As long as the combined total of fibrous webs A and B contains cellulosic fibers and adhesive fibers, the proportions of cellulose fibers and adhesive fibers in each of the fibrous webs are not particularly limited. For example, fibrous web B, which is a fibrous web separate from fibrous web A, may contain adhesive fibers in an amount of 20% by mass to 80% by mass.

[0062] For example, fibrous web A may be a parallel web made of a mixture of rayon fibers and adhesive fibers in a mass ratio of 70:30, and fibrous web B may be a random web made of a mixture of solvent-spun cellulose fibers and adhesive fibers in a mass ratio of 80:20. In this case, fibrous webs A and B may have the same basis weight or different basis weights. When two or more fibrous webs are laminated, the basis weight of each fibrous web is determined so that the resulting nonwoven fabric has the desired basis weight.

[0063] Fiber web A and / or fiber web B may be mainly composed of adhesive fibers alone, or adhesive fibers and fibers other than cellulosic fibers. The specific configuration of fiber webs A and B mainly composed of adhesive fibers and other fibers is explained above by replacing "cellulosic fibers" with "other fibers." Alternatively, one of the fibrous webs A and B may be a web composed mainly of adhesive fibers only or adhesive fibers and cellulosic fibers, and the other may be a fibrous web containing adhesive fibers and cellulosic fibers.

[0064] When fiber web A and fiber web B are prepared separately, one fiber web has a density of, for example, 5 g / m 2 ~75g / m 2 and in particular 10 g / m 2 ~60g / m 2 and more particularly 15 g / m 2 ~50g / m 2 and more particularly 20 g / m 2 ~40g / m 2 The fabric may have a basis weight of 10 ... Preparing the fibrous web may include separately preparing three or more fibrous webs on three or more web manufacturing lines.

[0065] Alternatively, a nonwoven fabric containing other fibers and / or cellulosic fibers may be prepared and laminated separately from the fiber web. Alternatively, a mesh sheet may be prepared and laminated separately from the fiber web. The other nonwoven fabric or mesh sheet (hereinafter collectively referred to as "substrate sheet") prepared separately from the fiber web may exist as an independent sheet, with the fibers already integrated by entanglement, adhesion, or the like. The substrate sheet can be integrated with the fiber web by entanglement of the fibers, and when the substrate sheet is sandwiched between two fiber webs as described below, the fibers are entangled between the two fiber webs via the substrate sheet. Therefore, it is preferable that the substrate sheet has voids or openings that allow for entanglement of the fibers.

[0066] Examples of the substrate sheet include nonwoven fabrics such as long fiber nonwoven fabrics (for example, spunbond nonwoven fabrics), meltblown nonwoven fabrics, airlaid nonwoven fabrics, and wetlaid nonwoven fabrics, and mesh sheets. The long-fiber nonwoven fabric may be a composite sheet of a sheet with threads aligned in the longitudinal direction and a sheet with threads aligned in the transverse direction, or a sheet obtained by laminating and integrating two or more net-like webs formed by splitting and stretching a film. Examples of such sheets that may be used include MILIFE (registered trademark) manufactured by JX ANCI Corporation and WARIF (registered trademark) manufactured by JX ANCI Corporation. When the base sheet is a long-fiber nonwoven fabric, the density of the long-fiber nonwoven fabrics exemplified above is relatively low, that is, the voids in the nonwoven fabric are relatively large, so that the entanglement of the fibers and the mechanical properties of the nonwoven fabric tend to be compatible.

[0067] The nonwoven fabric may be formed by laminating two or more types of nonwoven fabric. For example, the nonwoven fabric may be a laminated nonwoven fabric in which a spunbonded nonwoven fabric and a meltblown nonwoven fabric are laminated and integrated. The spunbonded nonwoven fabric may be made of, for example, synthetic fibers having a fineness of 0.5 dtex to 7.0 dtex, particularly 1.0 dtex to 4.0 dtex (the types of thermoplastic resins that can constitute the synthetic fibers are as described above). The meltblown nonwoven fabric may be made of, for example, synthetic fibers having a fineness of 0.005 dtex to 1.0 dtex, particularly 0.007 dtex to 0.7 dtex.

[0068] Examples of reticulated sheets include scrims and nets made by biaxially stretching thermoplastic resins. Examples of reticulated sheets that may be used include ConwedNet (registered trademark) manufactured by CONWED GLOBAL NETTING SOLUTIONS, Inc., USA. Reticulated sheets have a particularly good balance between void size and high mechanical properties, and tend to enable the entanglement process between fibers in a fiber web or between fiber webs via a base sheet to be carried out under milder conditions than when other base sheets are used. Milder conditions, for example, mean lowering the pressure of the liquid flow when the entanglement process is a high-pressure liquid flow treatment using a liquid flow.

[0069] Wetlaid nonwoven fabrics include tissues (also called tissue paper) containing pulp fibers, with the fibers bonded together by a binder and / or hydrogen bonds. Pulp fibers include mechanical pulp, recycled pulp, and chemical pulp. Wood pulp and non-wood pulp can be used as pulp fibers, and wood pulp produced by conventional methods using softwood or hardwood can be used as the wood pulp. Wetlaid nonwoven fabrics are less likely to inhibit entanglement of fibers between fiber webs and wetlaid nonwoven fabrics, and between two fiber webs, and improve the mechanical properties of the nonwoven fabric.

[0070] Laminating a base sheet to a fiber web tends to improve the mechanical properties of the nonwoven fabric, particularly the stress at 10% elongation. Therefore, when a base sheet is used, the bonding step after entanglement, which is required when constructing a nonwoven fabric using only a fiber web to obtain the desired mechanical properties, can sometimes be omitted.

[0071] The substrate sheet is, for example, 5 g / m 2 ~30g / m 2 and in particular 7 g / m 2 ~25g / m 2 and more particularly 10 g / m 2 ~20g / m 2The substrate sheets exemplified above may have a basis weight of 1 / 2.0001. Since the substrate sheets exemplified above are generally thin and low in bulk, if the basis weight is large, the proportion of the fiber layer containing cellulose fibers and adhesive fibers in a nonwoven fabric of a given basis weight will be small, the bulk of the nonwoven fabric will be small, and wiping properties may be reduced. Furthermore, if the basis weight of the substrate sheet is too large, the upper and lower fiber layers may not be sufficiently entangled, particularly when the nonwoven fabric is configured such that fiber layers containing cellulose fibers and adhesive fibers are arranged above and below the substrate sheet.

[0072] The density of the base sheet (under a load of 1.96 kPa) is, for example, 0.005 g / cm 3 More than 0.20g / cm 3 It may have a density of less than or equal to 0.010 g / cm 3 More than 0.15g / cm 3 It may have the following densities: When the base sheet is a long fiber nonwoven fabric, the long fiber nonwoven fabric has a density of, for example, 0.050 g / cm 3 More than 0.20g / cm 3 It may have a density (under 1.96 kPa load) of 0.070 g / cm 3 More than 0.15g / cm 3 It may have the following densities:

[0073] When the base sheet is a mesh sheet having regular openings (e.g., rectangular or square shapes defined by filaments), the opening size may be, for example, 3 mm or more, particularly 4 mm or more, and more particularly 5 mm or more. The upper limit of the opening size may be, for example, 15 mm, particularly 12 mm. The opening size is the length of the longest line segment connecting any two points on the outline defining the opening. If the opening size is too small, the upper and lower fiber layers may be insufficiently entangled, particularly when the nonwoven fabric is configured with fiber layers containing cellulosic fibers and adhesive fibers arranged above and below the base sheet. As a result, delamination may occur easily, or the pattern may become unclear if a pattern is formed in the highly entangled portions. A mesh sheet having regular openings may have an opening ratio of 50% to 99%, particularly 60% to 98%, more particularly 70% to 97%. When the opening ratio is within this range, the entanglement with the fibers tends to be good, and when fiber layers are positioned on both sides, good entanglement of the fibers between the fiber layers can be easily ensured.

[0074] The base sheet may have a stress at 10% elongation of 2.0 N / 5 cm or more in the MD direction and 0.5 N / 5 cm or more in the CD direction, for example. The stress at 10% elongation of the base sheet may be particularly 2.2 N / 5 cm or more in the MD direction and 0.7 N / 5 cm or more in the CD direction, more particularly 2.5 N / 5 cm or more in the MD direction and 1.0 N / 5 cm or more in the CD direction. The upper limit of the stress at 10% elongation of the base sheet may be, for example, 20 N / 5 cm in the MD direction and 20 N / 5 cm in the CD direction. A base sheet having a stress at 10% elongation within the above ranges can improve the handleability of the nonwoven fabric.

[0075] When producing a nonwoven fabric containing a base sheet, the step of laminating the base sheet on a fibrous web containing cellulosic fibers and adhesive fibers may be performed before or after the bonding step described below. Furthermore, after the bonding step, another fibrous web containing cellulosic fibers and adhesive fibers may be laminated on the composite web obtained by laminating the base sheet on the fibrous web. In this specification, the step of laminating the base sheet on the fibrous web is conveniently referred to as the "base sheet laminating step," and the step of laminating another fibrous web on the fibrous web or composite web is conveniently referred to as the "web laminating step." For example, the steps of preparing fibrous web A and fibrous web B as described above, and laminating fibrous web B on fibrous web A, and the step of laminating a base sheet on fibrous web A and then laminating fibrous web B correspond to web laminating steps.

[0076] If the base sheet lamination step is performed before the bonding step, the fiber web and the base sheet may be bonded in the bonding step, in which case, a nonwoven fabric with improved mechanical properties tends to be obtained. If the base sheet lamination step is performed after the bonding step, entanglement of the fibers tends to progress more in the subsequent entanglement step. Furthermore, if the web lamination step is performed after the base sheet lamination step, the base sheet is not exposed on either the front or back surface of the obtained nonwoven fabric, so the texture, feel, etc. can be prevented from changing significantly from those of a nonwoven fabric that does not contain a base sheet.

[0077] (Adhesion process) Next, the bonding process will be described. The bonding process is a process in which fibers are bonded together using adhesive fibers contained in a fiber web (or a composite web in the case of a composite web; hereinafter, when the term "fiber web" is used in connection with the bonding process, it refers to either a fiber web or a composite web) to form bonded areas.

[0078] The bonding step may be, for example, a thermal bonding step, which is a step of forming bonded portions by heat-treating a fiber web to melt or soften the component (thermal bonding component) with the lowest melting point among the resin components constituting the adhesive fibers, thereby bonding the fibers constituting the fiber web together.

[0079] The heat treatment may be, for example, a hot air processing treatment in which hot air is blown, a heat roll processing (e.g., a hot embossing roll processing), or a treatment using infrared rays. Hot air processing is preferred to make the resulting nonwoven fabric bulky. Hot air processing may be carried out using a device that blows hot air at a predetermined temperature onto the fiber web, such as a hot air penetration type heat treatment machine or a hot air blowing type heat treatment machine. In hot air processing using these devices, pressure is not easily applied in the thickness direction of the fiber web, so the resulting nonwoven fabric tends to be bulky.

[0080] When the bonding step is a hot air treatment, it is preferable to blow hot air multiple times. Furthermore, when blowing hot air multiple times, it is preferable that the temperature of the second hot air is higher than the temperature of the first hot air. Since the adhesive strength between the cellulosic fiber and the adhesive fiber is not higher than the adhesive strength between adhesive fibers, blowing hot air multiple times is effective in further enhancing the adhesive strength between the cellulosic fiber and the adhesive fiber.

[0081] When the bonding step is a hot air treatment, the hot air speed may be, for example, 0.1 m / min to 3.0 m / min, particularly 0.2 m / min to 2.5 m / min, and more particularly 0.3 m / min to 2.0 m / min, from the viewpoint of suppressing fluffing and ensuring bulkiness. If the hot air speed is too low, the fibers may not be bonded well to each other throughout the entire fiber web, and if it is too high, bulkiness may be impaired.

[0082] The heat treatment temperature may be the temperature at which the component (thermal adhesive component) with the lowest melting point among the resin components constituting the adhesive fiber softens or melts, for example, a temperature equal to or higher than the melting point of that component. For example, when the component with the lowest melting point among the resin components constituting the adhesive fiber is high-density polyethylene, hot air at a temperature of 130°C to 150°C may be blown when hot air processing is performed. For example, when the component with the lowest melting point among the resin components constituting the adhesive fiber is ethylene-acrylic acid copolymer, hot air at a temperature of 90°C to 140°C may be blown, particularly hot air at a temperature of 95°C to 130°C, and more particularly hot air at a temperature of 100°C to 120°C may be blown when hot air processing is performed. Furthermore, from the viewpoint of suppressing fuzzing and the degree of freedom of the fibers, the heat treatment temperature is preferably at least 0°C and not more than 5°C higher than the melting point or softening point of the thermal adhesive component, more preferably at least 1°C and not more than 4°C higher, and even more preferably at least 2°C and not more than 3°C higher.

[0083] The bonding step may be performed by irradiation with an electron beam or the like, or ultrasonic welding. These bonding processes also allow the resin component constituting the adhesive fiber to bond the fibers together.

[0084] For example, if the fibrous web after the bonding step has a MD breaking strength (tensile strength) of 1.0 N / 5 cm or more, sufficient bonding is achieved, making it easier to obtain a nonwoven fabric with good fuzz suppression. The MD breaking strength (tensile strength) may be particularly 2.0 N / 5 cm or more, more particularly 3.0 N / 5 cm or more. The MD breaking strength (tensile strength) of the fibrous web after the bonding step may have an upper limit of 100 N / 5 cm, particularly 70 N / 5 cm, and more particularly 40 N / 5 cm. Furthermore, the fibrous web after the bonding step may have a bending resistance of 100 g or less, measured, for example, according to JIS L 1096:2010 8.21.5 E method (handle-ometer method). In this case, it becomes easier to obtain a nonwoven fabric with high bulkiness and high fiber flexibility. The bending resistance may be particularly 80 g or less, more particularly 60 g or less. The lower limit of the bending resistance of the fibrous web after the bonding step may be 5 g, particularly 10 g, and more particularly 15 g. For example, if the thickness of the fibrous web after the bonding step is 0.90 mm or more under a load of 294 Pa, it becomes easier to obtain a nonwoven fabric with high bulk and a high degree of fiber freedom, and it also becomes easier to form highly entangled portions and less entangled portions well. The thickness under a load of 294 Pa may particularly be 1.1 mm or more, more particularly 1.3 mm or more. The upper limit of the thickness under a load of 294 Pa of the fibrous web after the bonding step may be 6.0 mm, particularly 5.0 mm, and more particularly 4.0 mm. For example, if the ratio (T1 / T2) of the thickness (T1) of the fiber web under a load of 294 Pa before the entanglement step described below to the thickness (T2) of the fiber web (nonwoven fabric) under a load of 294 Pa after the entanglement step is 1.2 or more, a nonwoven fabric with high bulkiness and a high degree of fiber freedom is easily obtained, and highly entangled portions and less entangled portions are easily formed. T1 / T2 may particularly be 1.3 or more, more particularly 1.4 or more. The upper limit of T1 / T2 may be 5.0, particularly 4.0, and more particularly 3.0.

[0085] (cooling process) The fiber web (composite web or laminate web; hereinafter, when referring to the cooling step, "fiber web" refers to the fiber web, composite web, or laminate web) subjected to the bonding step may be subjected to a cooling step before being subjected to the entangling step. More specifically, the fiber web or composite web may be subjected to a cooling step between the bonding step and the entangling step, between the bonding step and the base sheet lamination step, or between the bonding step and the web lamination step. Alternatively, if the fiber web or composite web is still hot after the lamination step and therefore the entire laminate web is hot, the laminate web may be subjected to a cooling step between the lamination step and the entangling step. The cooling step for the laminate web may be performed together with the cooling step for the fiber web or composite web, or the cooling step may be performed only after the laminate web has been formed.

[0086] If the fibrous web after the bonding step is subjected to the subsequent entanglement step while some of the adhesive fibers are softened or melted, peeling may occur at the bonded portions, making the resulting nonwoven fabric more susceptible to fuzzing. Therefore, in the cooling step, the fibrous web may be cooled until the adhesive component is solidified. The cooling step may be natural cooling (cooling naturally) or active cooling using a cooling device. The cooling method may be air cooling or water cooling. Natural cooling may be performed by running the fibrous web on a belt or between rolls until the fibrous web after the bonding step is sufficiently cooled.

[0087] (confounding process) Next, the intertwining step will be described. The entanglement step is a step of carrying out a treatment to entangle the fibers in the fiber web after the bonding step. In this embodiment, after the bonding step, it is preferable to subject the fiber web to the entanglement step without winding it up on a roll. Similarly, when subjecting a composite web or a laminate web to the entanglement step, it is preferable to subject the composite web or laminate web to the entanglement step without winding it up on a roll. In other words, at any time after the bonding step or before the entanglement step, it is preferable to subject the fiber web, composite web, or laminate web to the entanglement step without winding it up on a roll. This makes it easier for the fibers to be entangled and allows the resulting nonwoven fabric to have a higher bulk. Furthermore, when forming irregularities with the highly entangled portions as grooves and the less entangled portions as ridges, the fiber web after the bonding step can be subjected to the entanglement step without being wound up on a roll, which makes it easier to increase the bulk of the ridges, increase the degree of entanglement, and make the grooves denser. As a result, a nonwoven fabric can be obtained in which the ridges and grooves are clearly distinguishable from each other.

[0088] The entanglement process is, for example, a needle punch process or a high-pressure fluid flow (particularly a water flow) entanglement process. In a high-pressure fluid flow process, the high-pressure fluid is, for example, a high-pressure gas such as compressed air or a high-pressure liquid such as high-pressure water. In the production of nonwoven fabrics, a water flow entanglement process using high-pressure water as the high-pressure fluid is often used, and in this embodiment, the water flow entanglement process is preferably used from the viewpoint of ease of implementation. Below, an entanglement process when high-pressure water (hereinafter also simply referred to as "water flow") is used as the high-pressure fluid will be described.

[0089] In this embodiment, the entanglement step includes a partial entanglement step in which highly entangled portions, in which the degree of entanglement between fibers is higher, and less entangled portions, in which the degree of entanglement between fibers is lower than that of the highly entangled portions, are formed so that the highly entangled portions and less entangled portions are alternately arranged in a planar view. The partial entanglement step is carried out so that the width of the less entangled portions is 2 mm or more and 50 mm or less. The partial entanglement step may be carried out so that the width of the less entangled portions is 3 mm or more, particularly so that the width of the less entangled portions is 4 mm or more, and more particularly so that the width of the less entangled portions is greater than 5 mm. The partial entanglement step may be carried out so that the width of the less entangled portions is 25 mm or less, particularly so that the width of the less entangled portions is 20 mm or less, and more particularly so that the width of the less entangled portions is 10 mm or less. When the partial entanglement step is carried out as a hydroentanglement treatment, for example, 1) A nozzle with tiny orifices from which water jets are ejected, spaced, for example, a few millimeters apart, or 2) A nozzle in which an orifice assembly section, in which minute orifices from which water jets are arranged at intervals, and an orifice-less section, in which no orifices are drilled, are arranged alternately. can be used.

[0090] When nozzle 1) is used, the areas where the water stream from the orifice hits form streaks, forming highly entangled regions, while the areas not hit by the water stream form less entangled regions. The thickness of the highly entangled regions tends to be smaller than that of the less entangled regions. Depending on the type of fiber web used and the conditions of the bonding and entanglement processes, when nozzle 1) is used, it is possible to obtain a nonwoven fabric in which the less entangled regions rise up between the highly entangled regions to form ridges, and the highly entangled regions form grooves, as shown in Figure 1. In Figure 1, the surface of the nonwoven fabric at the top of the figure (top surface) is the surface onto which the water stream was sprayed during the partial entanglement process.

[0091] In nozzle 1), the orifices may have a hole diameter of, for example, 0.05 mm or more and 0.5 mm or less, and the spacing between the orifices may be, for example, 2 mm or more and 20 mm or less, particularly 3 mm or more and 15 mm or less, more particularly 4 mm or more and 10 mm or less, and even more particularly 5 mm or more and 10 mm or less. If the spacing between the orifices is too narrow, the distance between the highly entangled portions will be narrow, i.e., the width of the less entangled portions will be narrow, and the effect of forming the less entangled portions (e.g., improved dirt collection ability when used as a wiper) may not be obtained. If the spacing between the orifices is too large, the number or proportion of the highly entangled portions in the resulting nonwoven fabric will be small, and the strength of the nonwoven fabric may be insufficient. When the nozzle 1) is used, the water pressure of the water flow may be, for example, 1 MPa to 10 MPa, and in particular 1 MPa to 7 MPa.

[0092] The hydroentanglement treatment can be carried out by placing a fiber web (or a composite web or a laminate web; hereinafter, the term "fiber web" in relation to the hydroentanglement treatment refers to a fiber web, a composite web, or a laminate web) on a support and spraying a columnar water stream onto it. If the support has a flat, smooth nonwoven surface, each opening area of ​​0.2 mm 2 It is preferable to use a support that does not have openings exceeding 100 mesh and that does not have protrusions or patterns formed thereon. For example, it is preferable to use a plain woven support having a mesh size of 80 mesh or more and 100 mesh or less.

[0093] When nozzle 2) is used, the areas where the water jets from the orifices in the orifice assembly hit form band-like highly entangled regions, and the areas below the orifice-free areas form less entangled regions. The thickness of the highly entangled regions tends to be smaller than that of the less entangled regions. Depending on the type of fiber web used and the conditions of the bonding and entanglement processes, nozzle 2) can produce a nonwoven fabric in which the less entangled regions rise up between the highly entangled regions to form convex portions, as shown in Figure 2. Furthermore, compared to nozzle 1), wider highly entangled regions can be formed. By selecting a support that supports the nonwoven fabric while the water jets are being sprayed, a pattern resembling an open hole can be formed in the highly entangled regions. In Figure 2, the upper surface of the nonwoven fabric (top surface) is the surface sprayed with the water jet during the partial entanglement process.

[0094] In nozzle 2), the orifices may have a diameter of, for example, 0.05 mm or more and 0.5 mm or less, and the spacing between the orifices in the orifice assembly may be 0.3 mm or more and 1.5 mm or less. The width of the orifice-free section between the orifice assembly may be, for example, 2 mm or more and 50 mm or less, particularly 3 mm or more and 25 mm or less, more particularly 4 mm or more and 20 mm or less, even more particularly 4 mm or more and 10 mm or less, and even more particularly 5 mm or more and 10 mm or less. The width of the orifice assembly may be, for example, 2 mm or more and 50 mm or less, particularly 3 mm or more and 25 mm or less, more particularly 4 mm or more and 20 mm or less, and even more particularly 4 mm or more and 10 mm or less. Furthermore, when nozzle 2) is used, the water pressure of the water flow may be, for example, 1 MPa to 10 MPa, particularly 1 MPa to 7 MPa.

[0095] Whether nozzle 1) or 2) is used, by continuously passing the fiber web under the nozzle to perform the hydroentanglement treatment, it is possible to obtain a nonwoven fabric with highly entangled and less entangled portions arranged alternately in the CD direction in a plan view. Furthermore, whether nozzle 1) or 2) is used, in areas where the water stream is not sprayed, entanglement of the fibers does not substantially progress, forming less entangled portions. In such less entangled portions, the fibers are integrated by the adhesion of the adhesive fibers.

[0096] In either case of using nozzle 1) or 2), the nozzle may be a nozzle designed to apply a water flow over the entire surface, with the orifice in the section corresponding to the less entangled portion plugged.

[0097] Whether nozzle 1) or 2) is used, the hydroentanglement treatment in the partial entanglement step is preferably carried out by placing the fiber web on a support and spraying a columnar water stream only once onto one side of the fiber web. This is because, in the partial entanglement step, it is preferable to carry out the hydroentanglement treatment so as to form highly entangled portions and less entangled portions and to clearly define the boundaries between them. If the water stream is sprayed multiple times onto one side, or if the water stream is sprayed onto both sides, it becomes difficult to form highly entangled portions and less entangled portions.

[0098] The support has an opening area of ​​0.2 mm 2 The support may have no open holes exceeding 100 mesh, and no protrusions or patterns may be formed. Such a support may be, for example, a plain weave support of 80 mesh or more and 100 mesh or less. When a water flow is sprayed from nozzle 2) using such a support, the highly entangled portion becomes relatively flat and has no patterns or openings.

[0099] Alternatively, the support may be a plate-shaped or roll-shaped support, and particularly a roll-shaped support. When the support is in roll form, the fiber web curves, and the fiber density becomes lower in the thickness direction of the fiber web (or usually in the outward direction of the curved web). When a columnar water stream is sprayed from the outside, entanglement by the columnar water stream relatively easily progresses. In the manufacturing method of this embodiment, the fiber web including the bonded portions subjected to the bonding step is subjected to the entanglement step, so entanglement of the fibers relatively does not progress. Therefore, in the entanglement step, it is preferable to perform the hydroentanglement treatment in a state in which entanglement is more easily progressed.

[0100] When using nozzle 2), a pattern can be formed in the highly entangled portion by appropriately selecting the support. The support used to form the pattern (hereinafter referred to as "pattern-forming support") may be a woven fabric, a punched plate-like member, or a spiral net made of natural resin, synthetic resin, or metal. The pattern-forming support may also have a regular pattern formed by regularly arranging one or more selected from convex portions, concave portions, and openings. When such a pattern-forming support is used, a regular pattern can be formed by a collection of multiple regions (hereinafter referred to as "low-density regions") having a lower density than other portions. The low-density regions may be formed as open holes.

[0101] Specifically, the pattern formation support may be, for example, a plain weave, herringbone weave, twill weave, or satin weave woven from monofilaments with a fiber diameter of approximately 0.1 mm to 1.2 mm at a warp density of 10 to 30 threads / inch and a weft density of 10 to 30 threads / inch. A support made of a fabric with relatively thick filaments allows the formation of low-density regions because the intersections between the warp and weft threads form convex portions. When such a fabric is used, the area of ​​each low-density region is determined by the thickness of the threads constituting the fabric, and the spacing and pitch of the low-density regions are determined by the warp / weft density of the fabric.

[0102] In a plain weave fabric in which the warp and weft are each made of a single monofilament, the highest points of the intersections of the warp and weft become convex portions arranged in a staggered pattern, and therefore, by using such a plain weave fabric, low-density regions can be formed corresponding to these convex portions and arranged in a staggered pattern.

[0103] Alternatively, the pattern formation support may have convex portions and / or concave portions, for example, truncated cone-shaped, conical, truncated pyramidal, or pyramidal protrusions, or concave portions formed by subjecting the surface of a metal plate to cutting processing or the like, and the portions other than the convex portions and / or concave portions may be a plate-like member (e.g., a metal plate) having, for example, small openings formed therein to ensure water permeability. Alternatively, the patterned support may be a spiral net.

[0104] (Full-face entangling process) In the manufacturing method of this embodiment, the entanglement step may further include a full-scale entanglement step in which fibers are entangled throughout the entire fiber web (or composite web or laminate web; hereinafter, when the term "fiber web" is used in relation to the full-scale entanglement step, it refers to the fiber web, composite web, or laminate web). The full-scale entanglement step may be carried out before the partial entanglement step. The full-scale entanglement step is carried out when the entanglement of fibers in the partial entanglement step alone is not sufficient to provide the strength of the nonwoven fabric or to suppress fuzzing and shedding. By carrying out the full-scale entanglement step, the bulkiness of the resulting nonwoven fabric, particularly in the less entangled portions, is slightly reduced, but the strength of the entire nonwoven fabric can be increased and fuzzing is further suppressed.

[0105] The full-surface entanglement step may be a hydroentanglement treatment. The support used in the hydroentanglement treatment carried out as the full-surface entanglement step is the support described as being used in the partial entanglement step when no pattern is formed in the highly entangled portion. When such a support is used, the surface of the fiber web after the entanglement treatment becomes flat and has no irregularities.

[0106] The hydroentanglement treatment can be carried out, for example, by spraying water at a pressure of 1 MPa to 15 MPa from a nozzle having orifices with a hole diameter of 0.05 mm to 0.5 mm arranged at intervals of 0.3 mm to 1.5 mm onto each of the front and back surfaces of the fibrous web, 1 to 5 times. The water pressure is preferably 1 MPa to 10 MPa, more preferably 1 MPa to 7 MPa.

[0107] The full-scale entanglement step may be carried out so that the water pressure of the water stream is lower than that of the partial entanglement step. If the water pressure in the full-scale entanglement step is the same as or higher than that in the partial entanglement step, the bulkiness of the nonwoven fabric may decrease. That is, the full-scale entanglement step is preferably carried out using a water stream with as low a water pressure as possible, without excessively reducing the bulk of the nonwoven fabric, and to the extent necessary to integrate the fibers. In contrast, in the partial entanglement step, a water stream with a water pressure higher than that used in the full-scale entanglement step may be used to ensure the strength of the nonwoven fabric. In the partial entanglement step, since the area hit by the water stream is limited, even if the water pressure is increased, the reduction in the bulk of the entire nonwoven fabric is suppressed to some extent. Note that when the water stream in the full-scale entanglement step is sprayed multiple times, the water pressure of the water stream in each spray may be lower than that in the partial entanglement step.

[0108] The hydroentanglement treatment in the full-surface entanglement step may be carried out by spraying a water stream onto only one surface of the fibrous web. In this case, the partial entanglement step may be carried out by spraying a water stream onto the surface opposite to the surface sprayed with the water stream in the full-surface entanglement step. More specifically, both the full-surface entanglement step and the partial entanglement step may be carried out by hydroentanglement treatment in which a water stream is sprayed onto only one surface of the fibrous web, composite web, or laminate web, and the surface sprayed with the water stream in the partial entanglement step may be the surface opposite to the surface sprayed with the water stream in the full-surface entanglement step. In the partial entanglement step, spraying a water stream onto the surface opposite to the surface sprayed with the water stream in the full-surface entanglement step may sometimes allow the fibers to have a higher degree of freedom. Therefore, when the nonwoven fabric is used as a wiper, the dirt collection ability can be improved by using the surface sprayed with the water stream in the partial entanglement step as the wiping surface. Furthermore, when forming irregularities in which the highly entangled portions are grooves and the less entangled portions are ridges, the ridges and grooves can be formed more clearly by using different surfaces onto which the water flow is sprayed in the full entanglement process and the partial entanglement process.

[0109] When the bonding step is a hot air processing step, it is preferable that the hydroentangling step first sprays a columnar water stream onto the surface onto which hot air was blown in the hot air processing step (hereinafter referred to as the "hot air-blown surface"), and then sprays a columnar water stream onto the opposite surface. Therefore, when the entangling step includes a full-area entangling step, it is preferable to first spray a columnar water stream onto the hot air-blown surface, and then partially spray a water stream onto the opposite surface using nozzle 1) or 2). Alternatively, a columnar water stream may be sprayed onto the entire hot air-blown surface, and then a columnar water stream may be sprayed onto the entire opposite surface, and then hydroentangling may be performed using nozzle 1) or 2). In this case, the water stream from nozzle 1) or 2) may be sprayed onto the hot air-blown surface, or onto the opposite surface.

[0110] The surface onto which the hot air is blown tends to have a lower fiber density than the opposite surface (generally the surface in contact with the support during the hot air processing treatment), and entanglement by the columnar water stream is more likely to proceed. The strength of the nonwoven fabric and the degree of fuzz suppression achieved by the hydroentanglement treatment are likely to depend on the degree of entanglement in the initial entanglement treatment. Therefore, it is preferable to spray the columnar water stream from the side of the fibrous web where the fiber density is relatively low and where entanglement is more likely to proceed.

[0111] For example, when fiber webs A and B are prepared separately, fiber web A is subjected to a bonding step, fiber web B is laminated onto it, and the laminated web is subjected to a hydroentanglement treatment in the entanglement step, it is preferable to spray the columnar water stream first from the hot air blowing surface side of fiber web A. Therefore, for example, when fiber web B is laminated on the hot air blowing surface of fiber web A, it is preferable to spray the columnar water stream first from the side of fiber web B. Furthermore, when another nonwoven fabric is laminated on the hot air blowing surface of the fiber web, it is preferable to spray the columnar water stream first from the side of the other nonwoven fabric.

[0112] (drying process) In the manufacturing method of this embodiment, after the entangling step, the fiber web (or composite web or laminate web) may be subjected to a drying step. It is preferable to carry out a drying step, particularly when the entangling step includes a hydroentangling treatment. The drying step can be carried out by a hot air processing treatment in which hot air is blown, or the like. The temperature of the drying treatment is preferably lower than the softening or melting temperature of the adhesive component (thermal adhesive component) of the adhesive fiber. The temperature of the drying treatment is preferably 10°C or more lower than the melting point or softening point of the thermal adhesive component, more preferably 15°C or more lower, and even more preferably 20°C or less lower. In the manufacturing method of this embodiment, after the entangling step, the fiber web may be subjected to a second bonding step as described below, or it is not necessary to perform the second bonding step. If a second bonding step is performed, the drying step may be omitted.

[0113] (Gluing process after interlacing) In the manufacturing method of this embodiment, the fiber web (or composite web or laminate web; hereinafter, when the term "fiber web" is used in connection with the post-entangling bonding step, it refers to the fiber web, composite web, or laminate web) after the entangling step may be further subjected to a bonding step. This bonding step is referred to as the "post-entangling bonding step" to distinguish it from the bonding step carried out before the entangling step. The conditions used in the post-entangling bonding step are the same as those described in connection with the bonding step.

[0114] In the entanglement step, the bonded portions may be destroyed due to the impact of the water jets, etc. If the destruction is significant, the improvement in strength of the nonwoven fabric and the effect of suppressing fuzzing due to the adhesion of the fibers may not be achieved. The post-entanglement bonding step may be performed to compensate for the decrease in strength due to such destruction. Therefore, the conditions for the post-entanglement bonding step are appropriately selected depending on the degree of destruction of the bonded portions in the entanglement step and the physical properties of the nonwoven fabric to be finally obtained. For example, the post-entanglement bonding step may be performed at a lower or higher temperature than the temperature in the bonding step. Alternatively, the post-entanglement bonding step may be performed under the same conditions as the bonding step. Generally, nonwoven fabrics produced by a manufacturing method including a post-entanglement bonding step are less likely to fluff or fall off compared to nonwoven fabrics produced by a manufacturing method that does not include this step. Furthermore, although the bulk of the fiber web after the entanglement treatment is reduced, the bulk of the fiber web can be restored by subsequently carrying out a bonding step, particularly a hot air treatment. Therefore, a manufacturing method including a post-entanglement bonding step can sometimes produce a bulkier nonwoven fabric. In particular, when the entanglement step includes a hydroentanglement treatment, evaporation of water during the post-entanglement bonding treatment eliminates "sagging" due to the weight of the water, and it is thought that the bulk of the fiber web can be more easily restored.

[0115] [Embodiment 2] (Manufacturing method including lamination process) The manufacturing method of the second embodiment of the present disclosure includes a lamination step in which fiber webs A and B are prepared separately, only fiber web A is subjected to a bonding step, and fiber web B is laminated on fiber web A after the bonding step to obtain a laminated web. This manufacturing method makes it easy to incorporate various types of fibers into the entire nonwoven fabric. In the manufacturing method of the second embodiment, the laminated web is subjected to an entanglement step. The fiber web to be subjected to the entanglement step has a portion (fiber web B) that does not have any bonded portions formed therein, so spraying a water stream thereon tends to further promote entanglement. Therefore, sufficient entanglement is likely to be achieved even if the water pressure of the water stream used in the entanglement step is reduced or the proportion of cellulosic fibers is reduced. Furthermore, in the manufacturing method of the second embodiment, when a pattern is formed in a highly entangled portion, a clear pattern is likely to be formed. On the other hand, in the manufacturing method of the second embodiment, the number of bonded portions in the fiber web after the entanglement step is reduced compared to when the entire fiber web is subjected to the bonding step and then the entanglement step is performed. Therefore, in the manufacturing method of the second embodiment, it is preferable to perform a bonding step after entanglement.

[0116] Alternatively, the manufacturing method of the second embodiment of the present disclosure may include a base sheet laminating step in which a base sheet is laminated after the bonding step of the fibrous web A, or may include a web laminating step in which a fibrous web B is laminated after the base sheet laminating step. Nonwoven fabrics laminated with a base sheet generally tend to have higher mechanical properties (particularly stress at 10% elongation) than nonwoven fabrics that do not include a base sheet. Therefore, by using a base sheet, it is possible to obtain a nonwoven fabric that is less prone to pilling or shedding and that meets the mechanical properties required for a certain application, even when a post-entanglement bonding step is not performed.

[0117] When a base sheet is laminated, the entanglement treatment may be performed using a higher water pressure than when a base sheet is not laminated, so as to prevent peeling between the base sheet and the fiber web. When the base sheet is a long-fiber nonwoven fabric in particular, peeling between the base sheet and the fiber web is likely to occur, so a higher water pressure may be used.

[0118] In the manufacturing method of Embodiment 2, the conditions for the bonding step, entangling step, post-entangling bonding step, and drying step are the same as those described in or related to the manufacturing method of Embodiment 1, and therefore will not be described here again, although the conditions for these steps are appropriately adjusted depending on the types and proportions of fibers contained in fibrous webs A and B and their basis weights.

[0119] [Embodiment 3] (Nonwoven fabric obtained by the manufacturing method of the present disclosure) Next, a nonwoven fabric obtained by the manufacturing method of the first or second embodiment described above will be described as a third embodiment of the present disclosure.

[0120] The nonwoven fabric of this embodiment is produced by a method including a bonding step, an entanglement step including a partial entanglement step, and optionally a post-entanglement bonding step, and therefore includes bonded portions where fibers are bonded to each other, as well as portions where fibers are relatively tightly entangled. In particular, in the partial entanglement step, the fibers are more tightly entangled at the portions where the water stream is sprayed, forming highly entangled portions. In the partial entanglement step, the portions where the water stream is not sprayed form less entangled portions, where the degree of entanglement between fibers is lower than in the highly entangled portions.

[0121] The highly entangled portions and the less entangled portions are alternately arranged in one direction of the nonwoven fabric, and in nonwoven fabrics produced using the nozzle 1) or 2) above, they are alternately arranged in the CD direction of the nonwoven fabric. Furthermore, the thickness of the highly entangled portions tends to be smaller than that of the less entangled portions, which can result in the formation of irregularities with the highly entangled portions acting as grooves and the less entangled portions acting as ridges. The irregularities are particularly likely to be formed when the production method including the lamination step described in the second embodiment above is employed.

[0122] The ease of forming irregularities also varies depending on the mixing ratio of cellulosic fibers and adhesive fibers. For example, the higher the proportion of cellulosic fibers, the fewer the number of bonded points formed in the bonding step. Therefore, to ensure the strength of the nonwoven fabric, it is necessary to perform a full-scale entanglement step before the partial entanglement step. However, the full-scale entanglement step reduces the overall bulk of the nonwoven fabric, making it difficult for irregularities to form even when the partial entanglement step is performed. On the other hand, the higher the proportion of adhesive fibers, the greater the number of bonded points formed in the bonding step, and the smaller the proportion of cellulosic fibers that contribute to fiber entanglement. Therefore, even when the partial entanglement step is performed, it is difficult for a difference in the degree of entanglement to occur between the highly entangled and the less entangled parts, making it difficult for irregularities to form.

[0123] The highly entangled portions are areas where the fibers are more tightly entangled with each other, contributing to a certain degree of strength of the nonwoven fabric. The less entangled portions have a relatively high degree of entanglement between the fibers, which contributes to a certain degree of bulkiness of the nonwoven fabric. Furthermore, although the less entangled portions have a relatively high degree of entanglement, the fibers are bonded together, which reduces the likelihood of fuzzing. Furthermore, in the nonwoven fabric of this embodiment, the less entangled portions may have a width of 2 mm to 50 mm. By having less entangled portions of such widths, the overall nonwoven fabric can have a relatively high degree of entanglement. The width of the less entangled portions may be particularly 3 mm to 25 mm, more particularly 4 mm to 20 mm, even more particularly 4 mm to 10 mm, and even more particularly 5 mm to 10 mm.

[0124] Therefore, when the nonwoven fabric of this embodiment is used as, for example, a wiper, the highly entangled portions play a role in ensuring the strength of the wiper, and the loosely entangled portions play a role in wiping and collecting dirt. Furthermore, when the nonwoven fabric of this embodiment is used as a wiper, even if it is rubbed against a person's body or an object to wipe off dirt, pilling is unlikely to occur.

[0125] The widths of the highly entangled portions and the less entangled portions are determined by the type of nozzle used in partial entanglement and the spacing between the orifices in the nozzle (in the case of nozzle 1) or the width and spacing of the orifice assembly portions (in the case of nozzle 2). When nozzle 1) is used, the highly entangled portions are substantially linear, and less entangled portions are formed having a width equivalent to the spacing between the orifices. When nozzle 2) is used, highly entangled portions are formed having a width equivalent to the width of the orifice assembly portions, and less entangled portions are formed having a width equivalent to the spacing between the orifice assembly portions (the distance from one end of an orifice assembly portion to the end of an adjacent orifice assembly portion).

[0126] When nozzle 2) is used, as described above, low-density regions can be regularly formed in the highly entangled portions to form a pattern. A nonwoven fabric having a pattern formed in the highly entangled portions exhibits a design effect. Furthermore, by forming low-density regions in the highly entangled portions, when the obtained nonwoven fabric is used as a wiper, the low-density regions can improve the dirt collection ability. Each low density area is, for example, 0.03 mm 2 ~20mm 2 and in particular, 0.1 mm 2 ~10mm 2 and more particularly, 0.7 mm 2 ~5.0mm 2 If the low-density region is too small, it may not be sufficiently recognized, and the design effect may not be fully exhibited. If the low-density region is too large, the nonwoven fabric may be easily deformed or damaged, such as stretched, twisted, or torn, and the handling properties may be reduced. Furthermore, if the low-density region is too large, it may be difficult to recognize it as a low-density region, and the design effect may not be fully exhibited.

[0127] The low-density regions may be open pores where no fibers are present, or may not be open pores. Alternatively, a single nonwoven fabric may have both open pores and non-open pore low-density regions to form a pattern.

[0128] The basis weight of the nonwoven fabric of this embodiment is, for example, 10 g / m 2 ~150g / m 2 and in particular 15 g / m 2 ~120g / m 2 and more particularly 30 g / m 2 ~100g / m 2 and more particularly 40 g / m 2 ~80g / m 2 The fabric may have a basis weight of 10 ...

[0129] The nonwoven fabric of this embodiment has a density of, for example, 0.0100 g / cm 3 as a whole when dry. 3 ~0.100g / cm 3 and may have a fiber density of 0.0125 g / cm 3 ~0.0600g / cm 3 and preferably has a fiber density of 0.0180 g / cm 3 ~0.0500g / cm 3 It is more preferable that the fiber density of the entire nonwoven fabric is 1.96 kPa. The fiber density of the entire nonwoven fabric can be determined from the basis weight and thickness (thickness measured by applying a load of 1.96 kPa).

[0130] In the nonwoven fabric of this embodiment, it is preferable that adhesion / peeling marks, where the adhesive fiber's adhesion points have been eliminated, are formed in the adhesive fibers. Adhesion / peeling marks can be formed mainly in the entanglement process that follows the bonding process. In adhesion / peeling marks, the adhesive component (for example, the sheath component in the case of a core-sheath composite fiber) is present in a thin layer compared to the fiber surface of a normal adhesive fiber. These adhesion / peeling marks make the fibers more flexible, which can improve the flexibility of the nonwoven fabric, so it is preferable that adhesion / peeling marks are appropriately included. Adhesion / peeling marks can be confirmed by observing the surface or cross section of the nonwoven fabric using an electron microscope.

[0131] The nonwoven fabric of this embodiment has an adhesion intersection index A of 1 / mm 2 ~63 pieces / mm 2 The upper limit of the adhesive intersection index A is particularly 60 / mm 2 and more particularly 55 pieces / mm 2and even more particularly 50 pieces / mm 2 The lower limit of the adhesive intersection index A is particularly 3 / mm 2 and more particularly 5 pieces / mm 2 and more particularly 10 pieces / mm 2 and even more particularly 25 pieces / mm 2 When the bond intersection index A of the nonwoven fabric is within the above-mentioned range, fluffing of the nonwoven fabric is suppressed and the degree of freedom of the fibers is adequately ensured. The bond intersection index of the nonwoven fabric may differ between the highly entangled portions and the low entangled portions, and in such cases, the bond intersection index of the low entangled portions is taken as the bond intersection index of the nonwoven fabric. However, it is preferable that the bond intersection index A is within the above-mentioned range in both the highly entangled portions and the low entangled portions.

[0132] When the nonwoven fabric of this embodiment described in the examples below is divided into three equal parts in the thickness direction, the angle of the fiber bonding intersections at either or both of the upper and lower parts of the nonwoven fabric is preferably 35 degrees to 90 degrees, more preferably 35 degrees to 70 degrees, and even more preferably 40 degrees to 60 degrees. The nonwoven fabric of this embodiment tends to be highly bulky when the angle of the bonded fiber intersections in either or both of the upper and lower portions of the nonwoven fabric, i.e., in the portions near one or both surfaces of the nonwoven fabric, is within the above-mentioned range. The angle of the bonded fiber intersections may differ between the highly entangled portions and the low entangled portions. In such cases, the angle of the bonded fiber intersections in the low entangled portions is defined as the angle of the bonded fiber intersections of the nonwoven fabric. However, it is preferable that the angle of the bonded fiber intersections in both the highly entangled portions and the low entangled portions be within the above-mentioned range.

[0133] In the nonwoven fabric of this embodiment, when the highly entangled portions and the less entangled portions form grooves and ridges, respectively, and one surface has an uneven surface, the angle of the bonded fiber intersections on the uneven surface may be within the above range. When the angle of the bonded fiber intersections on the uneven surface is within the above range, the degree of freedom of the fibers on that surface is relatively high, and when the uneven surface is used as the wiping surface of a wiper, for example, the low fiber density in the convex portions (ridges) will result in good dirt collection properties.

[0134] The nonwoven fabric of this embodiment may be a nonwoven fabric having a fluff shedding amount of 1.5 mg to 20 mg on at least one side, as described in the Examples below. The nonwoven fabric of this embodiment may be a nonwoven fabric having a fluff shedding amount of 1.5 mg to 20 mg on both sides. When the fluff shedding amount on at least one side is within the above range, the fiber has a high degree of freedom on that side and fluffing is less likely to occur. Therefore, when the nonwoven fabric is used as a wiper, when that side is used as the wiping surface, it has good dirt collection properties and fluffing during wiping is suppressed, giving the user a clean impression. The fluff shedding amount on at least one side may particularly be 2.0 mg to 15 mg.

[0135] The surface of the nonwoven fabric having the amount of fluff shedding within the above range may be a surface in which the highly entangled parts and the less entangled parts form grooves and ridges, respectively (i.e., an uneven surface). If the amount of fluff shedding from the uneven surface is within the above range, when the uneven surface is used as the wiping surface of a wiper, for example, fluffing is unlikely to occur and the unevenness can effectively capture dirt.

[0136] With regard to the breaking strength (tensile strength) of the nonwoven fabric of this embodiment, which will be described in the examples below, the breaking strength (tensile strength) in the MD direction may be, for example, 10 N to 200 N, and particularly 30 N to 150 N. The breaking strength (tensile strength) in the CD direction may be, for example, 1 N to 30 N, and particularly 2 N to 20 N. When the strength of the nonwoven fabric is within the above-mentioned ranges, the handleability of the nonwoven fabric of this embodiment tends to be further improved.

[0137] The nonwoven fabric of this embodiment includes bonded portions formed by bonding fibers together, while ensuring a certain degree of freedom of the fibers and having bulky, less entangled portions, and is therefore preferably used as a wiper. When used as a wiper, the wiper may be a wet wiper impregnated with a cleaning liquid. Because the nonwoven fabric of this embodiment includes cellulosic fibers, it is easy to impregnate the cleaning liquid.

[0138] Alternatively, the nonwoven fabric of the present embodiment can also be used as various sheets such as top sheets, second sheets, and back sheets of absorbent articles, filters, sanitary masks, gauze, face masks impregnated with cosmetics, patches, packaging materials, mats, cushioning materials, tablecloths, carpet backing materials, wallpaper, and the like.

[0139] [Embodiment 4] A method for producing a nonwoven fabric according to a fourth embodiment of the present disclosure includes: A method for producing a nonwoven fabric containing adhesive fibers, comprising: In a fiber web containing the adhesive fibers, the method includes a bonding step of bonding fibers to each other with the adhesive fibers, and an entanglement step of entangling the fibers to each other after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a planar view, and the less entangled parts have a width of 2 mm or more and 50 mm or less. A method for manufacturing nonwoven fabric.

[0140] In the manufacturing method of embodiment 4, the adhesive fibers used, the conditions for the bonding step, the entangling step, the post-entangling bonding step, and the drying step can be appropriately the same as those described in the manufacturing method of embodiment 1.

[0141] [Embodiment 5] A method for producing a nonwoven fabric according to a fifth embodiment of the present disclosure includes: A method for producing a nonwoven fabric comprising a fiber layer containing adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, comprising: In a fiber web containing the adhesive fibers, the method includes a bonding step of bonding fibers to each other with the adhesive fibers, and an entanglement step of entangling the fibers to each other after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a plan view and the less entangled parts have a width of 2 mm or more and 50 mm or less; a base sheet laminating step of laminating the base sheet on the fiber web to obtain a composite web, which is performed before or after the bonding step and before the entangling step; A method for manufacturing nonwoven fabric.

[0142] In the manufacturing method of embodiment 5, the adhesive fibers, base sheet, bonding process, entanglement process, post-entanglement bonding process, and drying process conditions, etc., described in the manufacturing method of embodiment 1 can be applied as appropriate.

[0143] [Embodiment 6] The nonwoven fabric obtained by the manufacturing method of embodiment 4 will be described as the nonwoven fabric of embodiment 6 of the present disclosure. That is, the nonwoven fabric of embodiment 6 of the present disclosure is A nonwoven fabric comprising adhesive fibers, The adhesive fibers include adhesive points between each other, The adhesive fibers include entangled portions, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, The nonwoven fabric has a fluff shedding amount of 1.5 mg or more and 20 mg or less on at least one surface of the nonwoven fabric, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff.

[0144] In the nonwoven fabric of embodiment 6, the conditions such as adhesive fibers, bonded locations, entangled locations, highly entangled sections, less entangled sections, the width of the less entangled sections, and the amount of fluff shedding from the nonwoven fabric can be appropriately applied from the conditions described in embodiment 1 or embodiment 3.

[0145] [Embodiment 7] The nonwoven fabric obtained by the manufacturing method of embodiment 5 will be described as the nonwoven fabric of embodiment 7 of the present disclosure. That is, the nonwoven fabric of embodiment 7 of the present disclosure is A nonwoven fabric comprising a fiber layer containing adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, The adhesive fibers include adhesive points between each other, The adhesive fibers include entangled portions, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, The nonwoven fabric has a fluff shedding amount of 1.5 mg or more and 20 mg or less on at least one surface of the nonwoven fabric, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff.

[0146] In the nonwoven fabric of embodiment 7, the conditions such as the adhesive fibers, base sheet, bonded areas, entangled areas, highly entangled areas, less entangled areas, the width of the less entangled areas, and the amount of fluff shedding from the nonwoven fabric can be appropriately applied to the conditions described in embodiment 1 or embodiment 3.

[0147] The nonwoven fabric of embodiment 6 or the nonwoven fabric of embodiment 7 includes bonded portions formed by bonding fibers together, ensures a certain degree of freedom of fibers, and has bulky, less entangled portions, and is therefore preferably used as a wiper. When used as a wiper, the wiper may be a wet wiper impregnated with a cleaning liquid. [Example]

[0148] The fibers used to produce the nonwoven fabrics of the Examples and Comparative Examples are shown below. Fiber 1 (adhesive fiber): An eccentric core-sheath composite fiber having a polyethylene terephthalate core and a high-density polyethylene (melting point: approximately 133°C) sheath, a fineness of 2.6 dtex, a fiber length of 51 mm, and a three-dimensional crimp with an eccentricity of 25% (NBF(SH)V (product name) manufactured by Daiwabo Polytec Co., Ltd.). Fiber 2 (cellulosic fiber): Viscose rayon fiber with a fineness of 1.7 dtex and a fiber length of 40 mm (Corona CD (product name) manufactured by Daiwabo Rayon Co., Ltd.).

[0149] <Production of Nonwoven Fabric of Example 1> Fiber 1 and fiber 2 were mixed in a mixing ratio of 7:3 (mass ratio) and a parallel carding machine was used to produce fiber web A. The basis weight (target basis weight) of fiber web A was 30 g / m 2 It was. [Adhesion process / cooling process] Fiber web A was heated for about 5 seconds by blowing hot air at 135°C using a hot air penetration type heat treatment machine. This caused the fibers to be thermally bonded (adhesive treatment) by the sheath component of fiber 1. After thermal bonding (adhesive treatment), the fiber web was subjected to a cooling step in an atmosphere at room temperature of 20°C by natural cooling. [Web lamination process] Fiber 1 and fiber 2 were mixed at a ratio of 7:3 (by mass), and a parallel carding machine was used to card the target weight to 30 g / m 2 A fibrous web B was produced and laminated on the cooled fibrous web A to obtain a laminated web.

[0150] [Full-scale entangling process] The above-mentioned laminated web was placed on a plain weave net with a warp diameter of 0.132 mm, a weft diameter of 0.132 mm, and a mesh count of 90. While the laminated web was advanced at a speed of 4 m / min, a water supply device was used to spray a columnar water stream at a water pressure of 1.5 MPa onto the surface of fiber web B of the laminated web. The nozzle of the water supply device had orifices with a hole diameter of 0.12 mm spaced 0.6 mm apart. The distance between the surface of the laminated web and the orifices was 15 mm. After the bonding process, fiber web A and the laminated web were subjected to a full-surface entanglement process without being wound up on a roll.

[0151] [Partial confounding process] After the full-surface entanglement process, the laminated web was placed on a 25-mesh plain-weave support (warp and weft densities of both 25 threads / inch) made of 0.7 mm diameter monofilaments, and a columnar water stream was sprayed onto the surface of the fibrous web A of the laminated web. This entanglement process resulted in the formation of grooves, which were highly entangled regions extending along the MD of the nonwoven fabric, where the water stream was sprayed. Areas not sprayed with the water stream became less entangled regions, forming ridges. The highly entangled and less entangled regions were alternately arranged in the CD of the nonwoven fabric. The nozzle of the water supply machine used in the full-surface entanglement process was the same as that used in the full-surface entanglement process, but some of the multiple orifices were blocked to prevent the water stream from coming out, so that the widths of the ridges and grooves formed were each 6 mm. The laminated web was advanced at a speed of 4 m / min, the water pressure of the columnar water stream was 3.0 MPa, and the distance between the surface of the laminated web and the orifice was 15 mm. A pattern of staggered apertures was formed in the grooves. Each opening area is 1.05mm 2 The distance between the centers of the closest apertures was 1.5 mm.

[0152] [Gluing process after entangling] The laminated web after the entangling step was heated for about 5 seconds by blowing hot air at 135°C using a hot air penetration type heat treatment machine to dry the laminated web and thermally bond the fibers together using the sheath component of fiber 1, thereby obtaining a nonwoven fabric of Example 1.

[0153] <Production of Nonwoven Fabric of Example 2> The nonwoven fabric of Example 2 was obtained in the same manner as in Example 1, except that the partial entanglement step was changed as follows. [Partial confounding process] The laminated web was placed on the plain weave net used in the full-surface entanglement process, and columnar water streams were sprayed onto the surface of the fibrous web A. This entanglement process resulted in linear grooves of highly entangled regions extending along the MD direction of the nonwoven fabric where the water streams were sprayed. Regions where the water streams were not sprayed became less entangled regions, forming ridges. The nozzle of the water supply machine used was a nozzle with orifices with a hole diameter of 0.2 mm spaced 7 mm apart. The laminated web was advanced at a speed of 4 m / min, the water pressure of the columnar water streams was 3.0 MPa, and the distance between the surface of the laminated web and the orifices was 15 mm.

[0154] <Production of nonwoven fabric of Example 3> The nonwoven fabric of Example 3 was obtained in the same manner as the nonwoven fabric of Example 1, except that the mixing ratio of fiber 1 to fiber 2 in fiber webs A and B was 6:4 (mass ratio).

[0155] <Production of nonwoven fabric of Example 4> The nonwoven fabric of Example 4 was obtained in the same manner as the nonwoven fabric of Example 2, except that the mixing ratio of fiber 1 to fiber 2 in fiber webs A and B was 6:4 (mass ratio).

[0156] <Production of nonwoven fabric of Example 5> [Adhesion process / cooling process] Fiber 1 and fiber 2 were mixed in a ratio of 7:3 (mass ratio) and a fiber web was produced using a parallel carding machine. The target weight of the fiber web was 60 g / m 2 It was. This fiber web was heated for about 5 seconds by blowing hot air at 135°C using a hot air penetration type heat treatment machine. This caused the fibers to be thermally bonded (adhesive treatment) by the sheath component of fiber 1. After the thermal bonding (adhesive treatment), the fiber web was subjected to a cooling step in an atmosphere at room temperature of 20°C by natural cooling.

[0157] [Full-scale entangling process] The above-mentioned fiber web was placed on a plain weave net with a warp diameter of 0.132 mm, a weft diameter of 0.132 mm, and a mesh count of 90. While the fiber web was advanced at a speed of 4 m / min, a water supply device was used to spray a columnar water stream at a water pressure of 1.5 MPa onto the surface of the fiber web on the side where the hot air had been blown. The nozzle of the water supply device had orifices with a hole diameter of 0.12 mm spaced 0.6 mm apart. The distance between the surface of the fiber web and the orifices was 15 mm. After the bonding process, the fiber web was subjected to the entanglement process without being wound up on a roll.

[0158] [Partial confounding process] After the full-surface entanglement process, the nonwoven fabric was placed on a 25-mesh plain-weave support (warp and weft densities of 25 threads / inch) made of 0.7 mm diameter monofilaments, and a columnar water stream was sprayed onto the surface opposite to the surface sprayed with the water stream during the full-surface entanglement process. This entanglement process resulted in the formation of grooves, which were highly entangled regions extending along the MD of the nonwoven fabric, at the locations where the water stream was sprayed. Ridges were formed at locations where the water stream was not sprayed. The highly entangled and low-entangled regions were alternately arranged in the CD of the nonwoven fabric. The nozzle of the water supply machine used during the full-surface entanglement process was the same as that used during the full-surface entanglement process, but some of the multiple orifices were blocked to prevent the water stream from coming out, so that the widths of the ridges and grooves formed were each 6 mm. The fiber web was advanced at a speed of 4 m / min, the water pressure of the columnar water stream was 3.0 MPa, and the distance between the surface of the fiber web and the orifice was 15 mm. A pattern of staggered holes was formed in the grooves. Each hole had an area of ​​1.05 mm. 2 The distance between the centers of the closest apertures was 1.5 mm.

[0159] [Drying process] The fiber web after the entangling step was dried by heating for about 5 seconds using a hot air penetration type heat treatment machine by blowing hot air at 80° C., to obtain a nonwoven fabric of Example 5.

[0160] <Production of nonwoven fabric of Example 6> The nonwoven fabric of Example 6 was obtained in the same manner as in Example 5, except that the partial entanglement step was changed as follows. [Partial confounding process] The nonwoven fabric was placed on a plain weave net used in the full-surface entanglement process, and a columnar water stream was sprayed onto the surface opposite to the surface onto which the water stream was sprayed in the full-surface entanglement process. This entanglement process resulted in the formation of linear grooves, which were highly entangled regions extending along the MD direction of the nonwoven fabric, at the locations where the water stream was sprayed. Locations where the water stream was not sprayed became less entangled regions, forming ridges. The nozzle used for the water supply machine had orifices with a hole diameter of 0.2 mm spaced 7 mm apart. The speed at which the fibrous web fabric was advanced was 4 m / min, the water pressure of the columnar water stream was 3.0 MPa, and the distance between the surface of the fibrous web and the orifice was 15 mm.

[0161] <Production of nonwoven fabric of Example 7> The nonwoven fabric of Example 7 was obtained in the same manner as the nonwoven fabric of Example 5, except that a post-entanglement bonding step was carried out instead of the drying step after the entanglement step in Example 5. The post-entanglement bonding step was carried out by heating for about 5 seconds by blowing hot air at 135°C using a hot air penetration type heat treatment machine. In the post-entanglement bonding step, the fibers were thermally bonded (bonded) to each other by the sheath component of fiber 1.

[0162] <Production of nonwoven fabric of Example 8> The nonwoven fabric of Example 8 was obtained in the same manner as the nonwoven fabric of Example 6, except that a post-entanglement bonding step was carried out instead of the drying step after the entanglement step in Example 6. The post-entanglement bonding step was carried out by heating for about 5 seconds by blowing hot air at 135°C using a hot air penetration type heat treatment machine. In the post-entanglement bonding step, the fibers were thermally bonded (bonded) to each other by the sheath component of fiber 1.

[0163] <Production of nonwoven fabric of Example 9> Fiber 1 and fiber 2 were mixed in a mixing ratio of 7:3 (mass ratio) and a parallel carding machine was used to produce fiber web A. The basis weight (target basis weight) of fiber web A was 30 g / m 2 It was. [Adhesion process / cooling process] Fiber web A was heated for about 5 seconds by blowing hot air at 135°C using a hot air penetration type heat treatment machine. This caused the fibers to be thermally bonded (adhesive treatment) by the sheath component of fiber 1. After thermal bonding (adhesive treatment), the fiber web was subjected to a cooling step in an atmosphere at room temperature of 20°C by natural cooling. [Base sheet lamination process] Made of polypropylene, basis weight approx. 5.2g / m 2 A scrim (manufactured by JX ANCI Corporation, trade name Conwednet) with an opening size of 11.3 mm and an opening ratio of 96% was laminated to the surface of the fiber web A that had been subjected to the hot air blowing process after the bonding and cooling processes, to obtain a composite web. The stress of this scrim at 10% elongation was 12.8 N / 5 cm in the MD direction and 13.7 N / 5 cm in the CD direction, and the density (at a load of 1.96 kPa) was 0.017 g / cm. 3 It was. [Web lamination process] Fiber 1 and fiber 2 were mixed at a ratio of 7:3 (by mass), and a parallel carding machine was used to card the target weight to 25 g / m 2 A fibrous web B was produced as follows: a scrim was laminated on the composite web so that the scrim was sandwiched between fibrous webs A and B, thereby obtaining a laminated web.

[0164] [Full-scale entangling process] The above-mentioned laminated web was placed on a plain weave net with a warp diameter of 0.132 mm, a weft diameter of 0.132 mm, and a mesh count of 90. While the laminated web was advanced at a speed of 4 m / min, a water supply device was used to spray a columnar water stream at a water pressure of 2.0 MPa onto the surface of fiber web B of the laminated web. The nozzle of the water supply device had orifices with a hole diameter of 0.12 mm spaced 0.6 mm apart. The distance between the surface of the laminated web and the orifices was 15 mm. After the bonding process, fiber web A, the composite web, and the laminated web were subjected to a full-surface entanglement process without being wound up on a roll.

[0165] [Partial confounding process] After the full-surface entanglement process, the laminated web was placed on a 25-mesh plain-weave support (warp and weft densities of both 25 threads / inch) made of 0.7 mm diameter monofilaments, and a columnar water stream was sprayed onto the surface of the fibrous web A of the laminated web. This entanglement process resulted in the formation of grooves, which were highly entangled regions extending along the MD of the nonwoven fabric, where the water stream was sprayed. Areas not sprayed with the water stream became less entangled regions, forming ridges. The highly entangled and less entangled regions were alternately arranged in the CD of the nonwoven fabric. The nozzle of the water supply machine used in the full-surface entanglement process was the same as that used in the full-surface entanglement process, but some of the multiple orifices were blocked to prevent the water stream from coming out, so that the widths of the ridges and grooves formed were each 6 mm. The laminated web was advanced at a speed of 4 m / min, the water pressure of the columnar water stream was 4.5 MPa, and the distance between the surface of the laminated web and the orifice was 15 mm. A pattern of staggered apertures was formed in the grooves. Each opening area is 1.05mm 2 The distance between the centers of the closest apertures was 1.5 mm.

[0166] [Drying process] The laminated web after the entangling step was dried by heating for about 5 seconds using a hot air penetration type heat treatment machine by blowing hot air at 80° C., to obtain the nonwoven fabric of Example 9.

[0167] <Production of nonwoven fabric of Example 10> A nonwoven fabric of Example 10 was obtained in the same manner as in Example 9, except that the partial entanglement step was changed as follows. [Partial confounding process] The laminated web was placed on the plain weave net used in the full-surface entanglement process, and columnar water streams were sprayed onto the surface of the fibrous web A. This entanglement process resulted in linear grooves of highly entangled regions extending along the MD direction of the nonwoven fabric where the water streams were sprayed. Areas where the water streams were not sprayed became less entangled regions, forming ridges. The nozzle of the water supply machine used was a nozzle with orifices with a hole diameter of 0.2 mm spaced 7 mm apart. The laminated web was advanced at a speed of 4 m / min, the water pressure of the columnar water streams was 4.5 MPa, and the distance between the surface of the laminated web and the orifices was 15 mm.

[0168] <Production of nonwoven fabric of Example 11> The base sheet is made of polyethylene terephthalate with a basis weight of approximately 10.8 g / m 2 The spunbond nonwoven fabric (manufactured by Toyobo Co., Ltd., trade name Ekure) was used, and the basis weight of the fiber web B was 20 g / m 2 The nonwoven fabric of Example 11 was obtained in the same manner as the nonwoven fabric of Example 9, except that the stress at 10% elongation of this spunbonded nonwoven fabric was 6.8 N / 5 cm in the MD direction and 1.9 N / 5 cm in the CD direction, and the density (under a load of 1.96 kPa) was 0.098 g / cm 3 It was.

[0169] <Production of nonwoven fabric of Example 12> The base sheet is made of polyethylene terephthalate with a basis weight of approximately 10.8 g / m 2 The spunbond nonwoven fabric (manufactured by Toyobo Co., Ltd., trade name Ekure) was used, and the basis weight of the fiber web B was 20 g / m 2 The nonwoven fabric of Example 12 was obtained in the same manner as the nonwoven fabric of Example 10, except that the stress at 10% elongation of this spunbond nonwoven fabric was 6.8 N / 5 cm in the MD direction and 1.9 N / 5 cm in the CD direction, and the density (under a load of 1.96 kPa) was 0.098 g / cm 3 It was.

[0170] <Production of Nonwoven Fabric of Comparative Example 1> The nonwoven fabric of Comparative Example 1 was obtained in the same manner as the nonwoven fabric of Example 5, except that the bonding step and cooling step were not carried out after the fiber web was produced.

[0171] <Production of Nonwoven Fabric of Comparative Example 2> The nonwoven fabric of Comparative Example 2 was obtained in the same manner as the nonwoven fabric of Example 6, except that the bonding process and cooling process were not carried out after the fiber web was produced.

[0172] <Production of Nonwoven Fabric of Comparative Example 3> The nonwoven fabric of Comparative Example 3 was obtained in the same manner as the nonwoven fabric of Example 5, except that the bonding step and cooling step were not performed after producing the fiber web in Example 5, and a post-entanglement bonding step was performed instead of the drying step after the entanglement step. The conditions for the post-entanglement bonding step were the same as those for Example 7.

[0173] <Production of Nonwoven Fabric of Comparative Example 4> The nonwoven fabric of Comparative Example 4 was obtained in the same manner as in Example 6, except that the bonding step and cooling step were not performed after producing the fiber web, and a post-entanglement bonding step was performed instead of the drying step after the entanglement step. The conditions for the post-entanglement bonding step were the same as those for Example 8.

[0174] <Production of nonwoven fabric of Example 13> [Adhesion process / cooling process] A fiber web was produced using only fiber 1 using a parallel carding machine. The target weight of the fiber web was 60 g / m 2 It was. This fiber web was heated for about 5 seconds by blowing hot air at 135°C using a hot air penetration type heat treatment machine. This caused the fibers to be thermally bonded (adhesive treatment) by the sheath component of fiber 1. After the thermal bonding (adhesive treatment), the fiber web was subjected to a cooling step in an atmosphere at room temperature of 20°C by natural cooling.

[0175] [Full-scale entangling process] The above-mentioned fiber web was placed on a plain weave net with a warp diameter of 0.132 mm, a weft diameter of 0.132 mm, and a mesh count of 90. While the fiber web was advanced at a speed of 4 m / min, a water supply device was used to spray a columnar water stream at a water pressure of 1.5 MPa onto the surface of the fiber web on the side where the hot air had been blown. The nozzle of the water supply device had orifices with a hole diameter of 0.12 mm spaced 0.6 mm apart. The distance between the surface of the fiber web and the orifices was 15 mm. After the bonding process, the fiber web was subjected to the entanglement process without being wound up on a roll.

[0176] [Partial confounding process] The nonwoven fabric was placed on a plain weave net used in the full-surface entanglement process, and a columnar water stream was sprayed onto the surface opposite to the surface onto which the water stream was sprayed in the full-surface entanglement process. This entanglement process resulted in the formation of linear grooves, which were highly entangled regions extending along the MD direction of the nonwoven fabric, at the locations where the water stream was sprayed. Locations where the water stream was not sprayed became less entangled regions, forming ridges. The nozzle used for the water supply machine had orifices with a hole diameter of 0.2 mm spaced 7 mm apart. The speed at which the fiber web was advanced was 4 m / min, the water pressure of the columnar water stream was 3.0 MPa, and the distance between the surface of the fiber web and the orifice was 15 mm.

[0177] [Drying process] The fiber web after the entangling step was dried by heating for about 5 seconds using a hot air penetration type heat treatment machine by blowing hot air at 80° C., to obtain a nonwoven fabric of Example 13.

[0178] <Production of Nonwoven Fabric of Comparative Example 5> The nonwoven fabric of Comparative Example 5 was obtained in the same manner as the nonwoven fabric of Example 13, except that the bonding step and cooling step were not performed after producing the fiber web in Example 13, and a post-entanglement bonding step was performed instead of the drying step after the entanglement step. The conditions for the post-entanglement bonding step were the same as those for Example 8.

[0179] The nonwoven fabric was evaluated as follows. <Angle of fiber bond intersection> The nonwoven fabric was cut in the machine direction (MD, more specifically, the direction parallel to the direction of travel of the belt conveyors of the heat treatment machine and water jet treatment machine that treated the nonwoven fabric), and the cut surfaces were observed with a scanning electron microscope (SEM, magnification: 60x). The nonwoven fabric was divided into three equal parts in the thickness direction, and the apparent angle between the two fibers that form the bonded intersection was examined near the top and bottom of the nonwoven fabric and near the middle (middle). The apparent angles were examined at at least 15 locations, and the average value was calculated. The side on which the water jet was sprayed during the partial entanglement process was defined as the top, and the side on the opposite side was defined as the bottom.

[0180] <Adhesive intersection index A> The front and back surfaces of the nonwoven fabric were observed using a scanning electron microscope (SEM, accelerating voltage: 10.0 kV, magnification: 100x). The number of fiber adhesion intersections per area was counted for each of the SEM images taken. The number of fiber adhesion intersections was counted for a total of six SEM images, three for each of the front and back surfaces of the nonwoven fabric, and the average value was taken as the number of fiber adhesion intersections I (unit: pieces / mm 2 ) was decided. The adhesive intersection ratio P (0≦P≦1) was calculated from the fineness (dtex) of the non-adhesive fiber (fiber 2) and adhesive fiber (fiber 1) constituting the nonwoven fabrics of the Examples and Comparative Examples and their mixing ratios (mass%) in the nonwoven fabric, according to the following formula:

number

[0181] In the case of a two-layer structure, the adhesive intersection percentage P on the front or back side is calculated according to the cotton blending state on the front or back side. The adhesive intersection index A is still calculated by averaging the three front and three back side values.

[0182] <Thickness and density of nonwoven fabric> The thickness of the nonwoven fabric was measured using a thickness gauge (THICKNESS GAUGE Model CR-60A (trade name) manufactured by Daiei Scientific Instruments Manufacturing Co., Ltd.) while a load of 294 Pa or 1.96 kPa was applied to the nonwoven fabric. The density of the nonwoven fabric was calculated based on the basis weight of the nonwoven fabric and the thickness of the nonwoven fabric obtained by applying a load of 1.96 kPa.

[0183] <Strength and elongation> The strength and elongation were measured in accordance with JIS L 1913:2010 6.3. Using a constant-speed tension tensile tester, the tensile test was conducted under the conditions of a sample piece (nonwoven fabric) width of 5 cm, a grip spacing of 10 cm, and a tensile speed of 30±2 cm / min. The load value at break (tensile strength), elongation, and stress at 10% elongation were measured. The tensile test was conducted in the machine direction (MD) and cross direction (CD) of the nonwoven fabric as the tensile direction. The evaluation results were all expressed as the average of the values ​​measured for three samples.

[0184] <Fluffing index> The evaluation was carried out by an abrasion test using a Martindale fluff tester (manufactured by James Heal, trade name "Martindale Abrasion and Pilling Tester No. 1309"). Two samples (one with a diameter of 140 mm and one with a diameter of 38 mm) of the nonwoven fabrics of the Examples and Comparative Examples were prepared. A 140 mm diameter felt was placed on an abrading table, and the 140 mm diameter sample was layered on SM25 abrasive cloth and secured with a clamping ring. Next, a 38 mm diameter sample and a 38 mm diameter polyurethane were placed on a sample holder. The measurement conditions were as follows: the sample holder was placed on the abrading table without a loading weight. The friction test was performed with eight rotations and a motion of 60.5 mm Lissajous. For the Examples and Comparative Examples processed using a hot air penetration heat treatment machine, the friction test was performed so that the surfaces exposed to the hot air and the surfaces opposite to each other were in contact. After the measurement was completed, the nonwoven fabric on the sample holder side was observed, and the fluffing state was determined based on the following two criteria (the state of the nonwoven fabric after measurement when viewed from directly above (surface state) and the state of the nonwoven fabric after measurement when viewed from directly to the side (degree of fluffing)) and the total value (out of 10 points) was taken as the fluffing index. A total of 6 points or more is considered to indicate that fluffing is suppressed, and a total of less than 9 points is considered to indicate a high degree of freedom of the fibers. For each Example or Comparative Example, the evaluation test was performed twice, and the average of the two scores was taken as the fluffing index for each Example or Comparative Example. Surface condition 5: Very good (no surface irregularities) 4: Good (very little surface irregularity) 3: Normal (there is little surface irregularity and it is not noticeable) 2: Poor (some surface irregularities are noticeable) 1: Very poor (holes on the surface) Fluffiness 5: Very good (no pilling) 4: Good (very little pilling) 3: Normal (some pilling is not noticeable) 2: Poor (some noticeable pilling) 1: Very bad (lots of fluff)

[0185] <Lifting amount measurement test> a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff.

[0186] <Dirt collection ability> [Dust collection ability] 0.20 g of test powder (seven types) conforming to JIS Z 8901 was uniformly dispersed in a rectangular area measuring 5 cm in length and 15 cm in width (hereinafter referred to as the "dust dispersion area") approximately in the center of the surface of a white acrylic plate, and the test powder (dust) was wiped off using nonwoven fabrics (26 cm in length, 16 cm in width) from the Examples and Comparative Examples as wipers.

[0187] The wiping was performed with the area contributing to wiping being 26 cm vertically and 16 cm horizontally, with the nonwoven fabric attached to a wiper jig (product name: Quickle Wiper [tool body] head, manufactured by Kao Corporation) with a weight of 400 g applied so that the upper surface (the surface onto which the water jet was sprayed during the partial entanglement process) was the wiping surface. The wiping was performed by moving the wiper back and forth once on the surface of the white acrylic plate.

[0188] More specifically, Place the wiper in the center of the dust distribution area so that the vertical direction of the wiper coincides with the vertical direction of the dust distribution area; From there, move the wiper 250 mm toward the left end of the dust dispersion area, scraping the dust (white acrylic plate). Then, move the wiper 500 mm toward the right end of the dust dispersion area, Further, move the wiper 250 mm toward the left end of the dust dispersion area. I ran the wipers back and forth once.

[0189] After one reciprocal wiper movement, the dust collection rate was calculated from the pre-measured mass of the nonwoven fabric and the mass of the nonwoven fabric measured after wiping. For each nonwoven fabric, wiping was measured three times with the wiping surface of the nonwoven fabric fresh, and the average value was taken as the dust collection rate.

[0190] [Hair collection ability (wet state)] A total of five hairs (approximately 5 cm long) were placed on the flooring with a gap between them, three strands horizontally and two strands vertically, and the hairs were wiped off with the nonwoven fabrics of the Examples and Comparative Examples.

[0191] Wiping was performed in a wet state by impregnating 100 parts by mass of nonwoven fabric with 300 parts by mass of distilled water. The wiping was performed with the nonwoven fabric attached to a wiper jig (product name: Quickle Wiper [tool body] head, manufactured by Kao Corporation) so that the area contributing to wiping was 26 cm vertically and 16 cm horizontally, with the top surface (the surface onto which the water jet was sprayed during the partial entanglement process) facing the wiping surface, and with a 400 g weight applied. Wiping was performed using the same method as used in the dust capture evaluation above, with the wiper moving back and forth over the hair. After wiping, the hair capture rate (%) was calculated from the number of hairs wiped from the flooring. For each nonwoven fabric, wiping was performed three times with the wiping surface of the nonwoven fabric fresh, and the average value was used as the hair capture rate.

[0192] Tables 1 to 5 show the evaluation results of each example and each comparative example.

[0193] [Table 1]

[0194] [Table 2]

[0195] [Table 3]

[0196] [Table 4]

[0197] [Table 5]

[0198] All of the nonwoven fabrics of the Examples exhibited superior dust collection and hair collection in a wet state compared to the nonwoven fabrics of the Comparative Examples. In addition, all of the nonwoven fabrics of the Examples were relatively resistant to pilling.

[0199] The nonwoven fabrics of Comparative Examples 3 and 4 were produced by carrying out an entanglement step without carrying out a bonding step, and then carrying out a bonding step after entanglement. Therefore, it is presumed that the distance between the fibers became considerably shorter in the entanglement step, and the fibers were bonded together in this state. As a result, the bonded intersection index A was large and fuzzing was unlikely to occur. The nonwoven fabrics of Comparative Examples 1 and 2 were produced by a method that did not include any bonding step, and therefore the strength of the nonwoven fabrics was low and they were prone to fluffing. In the nonwoven fabrics of Comparative Examples 1 to 4, the bonding step was not performed before the entangling step, and therefore the entanglement of the fibers in the entanglement step proceeded more easily than in Examples, resulting in a smaller thickness of the nonwoven fabric, which is thought to be why the bulk was smaller overall and the dust collection ability and hair collection ability were both lower than in Examples.

[0200] Comparing Example 5 and Example 7, Example 7, which was produced using a method including a post-entanglement bonding process, had a larger bond intersection index A and was less likely to fuzz. Similarly, comparing Example 6 and Example 8, Example 8, which was produced using a method including a post-entanglement bonding process, was less likely to fuzz. Furthermore, comparing Example 5 and Example 7, Example 7 had a greater thickness, a lower fiber density, and was bulkier. This is thought to be because Example 7 was produced by drying and re-bonding with hot air after the entanglement process, eliminating "sagging" due to the weight of water, and because the application of hot air restored the bulk. In other words, in Example 7, the fibers were re-bonded in a bulky state, so the fibers were fixed together while maintaining a relatively high bulk, resulting in a bulky nonwoven fabric. The same is true when comparing Example 6 and Example 8.

[0201] Comparing Example 1 and Example 7, the nonwoven fabric of Example 1 was smaller in bulk and had smaller MD strength. This is thought to be because, in Example 1, fibrous web B was laminated on fibrous web A and subjected to the entanglement treatment without undergoing a bonding step, so the fibers of fibrous web B were more tightly entangled. The same was true when comparing Example 2 and Example 8.

[0202] Comparing Example 1 and Example 3, the nonwoven fabric of Example 1 was bulkier. This is thought to be because Example 3 contained a higher proportion of cellulosic fibers, which are easily entangled by hydroentanglement treatment. In Example 3, entanglement between fibers progressed more, shortening the distance between fibers, resulting in an increased number of bonded points. The bonded intersection index A was higher than in Example 1, but fuzzing was more likely to occur than in Example 1. This is thought to be because Example 3 contained a lower proportion of adhesive fibers, resulting in fewer bonded points between adhesive fibers, which are more effective in preventing fuzzing. However, this speculation does not limit the present disclosure in any way. The same is true when Example 2 and Example 4 are compared.

[0203] When Example 9, which contains a scrim, is compared with Examples 1 and 7, which were produced without a scrim and by a post-entanglement bonding process, the nonwoven fabric of Example 9 exhibited a higher stress at 10% elongation in both the MD and CD directions than either of the other Examples. When Example 11, which contains a spunbond nonwoven fabric, is compared with Examples 1 and 7, which were produced without a spunbond nonwoven fabric and by a post-entanglement bonding process, the stress at 10% elongation of Example 11 is higher than that of Example 7 and slightly lower than that of Example 1, but still usable. Similar trends were observed in comparisons of Example 10 with Examples 2 and 8, and Example 12 with Examples 2 and 8. In addition, other properties (such as collection ability, fluff index, and amount of fluff shedding) of Examples 9 to 12, which contain scrims or spunbond nonwoven fabrics, were comparable to those of the other Examples. From these findings, it was found that by using a base sheet such as a scrim or spunbond nonwoven fabric, it is possible to obtain a nonwoven fabric that is equivalent to or better than a nonwoven fabric without a base sheet that has undergone a post-entanglement bonding process in terms of stress at 10% elongation and other performance, even without performing a post-entanglement bonding process.

[0204] Since Example 13 is a nonwoven fabric containing only adhesive fibers, it was less likely to fluff than Example 6. On the other hand, since Example 13 does not contain any fibers other than adhesive fibers, the degree of freedom of the fibers is reduced, and the dust collection ability and hair collection ability were somewhat lower than those of Example 6. Comparative Example 5, which was produced without carrying out the bonding step before the entanglement step, was small in bulk overall, and both the dust collection ability and hair collection ability were lower than those of Example 13.

[0205] [Sesame seed collection ability (wet condition)] The nonwoven fabrics of each Example and Comparative Example were evaluated for their sesame seed collection ability in a wet state. To evaluate sesame seed collection ability, 10 sesame seeds were arranged at intervals in three rows (3-4-3 rows) on a flooring surface, and the nonwoven fabric was used to wipe the flooring in the same manner as in the evaluation of hair collection ability (wet state). After wiping, the collection rate (%) was calculated from the number of sesame seeds wiped off from the flooring. For each nonwoven fabric, the wiping was measured three times with the wiping surface of the nonwoven fabric fresh, and the average value was taken as the sesame seed collection rate. Table 6 shows the sesame seed collection performance of each example and comparative example.

[0206] [Table 6]

[0207] As shown in Table 6, the nonwoven fabrics of Examples 9 to 12, which contained a scrim or spunbonded nonwoven fabric, exhibited relatively high sesame capture ability in a wet state. Sesame capture ability is an indicator of wiping off dirt that is slightly larger than dust or hair, such as food debris that occurs in everyday life. Nonwoven fabrics containing scrim or spunbonded nonwoven fabrics are excellent at wiping off such slightly larger dirt because they undergo a single bonding process, allowing for a relatively high degree of fiber flexibility and preventing twisting when wet. This, combined with their dust capture ability and hair capture ability, makes them excellent wipers.

[0208] This embodiment includes the following aspects. (Aspect 1) A method for producing a nonwoven fabric containing cellulosic fibers and adhesive fibers, comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a planar view, and the less entangled parts have a width of 2 mm or more and 50 mm or less. Method for manufacturing nonwoven fabric. (Aspect 2) A method for producing a nonwoven fabric comprising a fiber layer containing cellulosic fibers and adhesive fibers, and a substrate sheet integrated with the fiber layer by entanglement of the fibers, comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a plan view and the less entangled parts have a width of 2 mm or more and 50 mm or less; a base sheet laminating step of laminating the base sheet on the fiber web to obtain a composite web, which is performed before or after the bonding step and before the entangling step; Method for manufacturing nonwoven fabric. (Aspect 3) A method for producing a nonwoven fabric according to aspect 2, wherein the base sheet is a long-fiber nonwoven fabric, a wet-laid nonwoven fabric, or a mesh sheet. (Aspect 4) The method for producing a nonwoven fabric of aspect 1 includes a web laminating step, after the bonding step and before the entangling step, of laminating another fibrous web containing cellulosic fibers and adhesive fibers onto the fibrous web to obtain a laminated web. (Aspect 5) The method for producing a nonwoven fabric of aspect 2 or 3, further comprising a web laminating step, after the bonding step and before the entangling step, of laminating another fibrous web containing cellulosic fibers and adhesive fibers such that the base sheet is located between the fibrous web and the other fibrous web, to obtain a laminated web. (Aspect 6) 6. The method for producing a nonwoven fabric according to claim 4 or 5, wherein the other fiber web contains 20% by mass or more and 80% by mass or less of the adhesive fiber. (Aspect 7) A method for producing a nonwoven fabric according to any one of aspects 1 to 6, wherein the highly entangled portions and the less entangled portions are arranged alternately in the CD direction of the nonwoven fabric. (Aspect 8) A method for producing a nonwoven fabric according to any one of aspects 1 to 7, wherein the entangling step comprises a hydroentangling treatment. (Aspect 9) A method for producing a nonwoven fabric according to any one of aspects 1 to 8, wherein the entangling step includes a full-surface entangling step of entangling fibers throughout the entire fiber web, the entire composite web, or the entire laminate web, and the fiber web, the composite web, or the laminate web is subjected to the partial entangling step after the full-surface entangling step. (Aspect 10) A method for producing a nonwoven fabric according to aspect 9, wherein the full-area entanglement step and the partial entanglement step are both carried out by hydroentanglement, and the water pressure in the hydroentanglement step in the full-area entanglement step is lower than the water pressure in the hydroentanglement step in the partial entanglement step. (Aspect 11) A method for producing a nonwoven fabric according to aspect 10, wherein the full-scale entanglement step and the partial entanglement step are both carried out by a hydroentanglement treatment in which a water stream is sprayed onto only one surface of the fiber web, the composite web, or the laminate web, and the surface onto which the water stream is sprayed in the partial entanglement step is the opposite surface to the surface onto which the water stream is sprayed in the full-scale entanglement step. (Aspect 12) 12. The method for producing a nonwoven fabric according to any one of aspects 1 to 11, wherein an open pattern is formed in the highly entangled portion in the partially entangled step. (Aspect 13) The bonding step includes a hot air processing treatment of applying hot air to one surface of the fiber web or the composite web, The entanglement step includes a hydroentanglement treatment, The hydroentanglement treatment includes spraying a water stream first onto the surface of the fiber web or the composite web that has been exposed to hot air, or spraying a water stream first onto the surface of the fiber web or the composite web that has been exposed to hot air, rather than onto the surface that has not been exposed to hot air. (Aspect 14) 14. The method for producing a nonwoven fabric of any of aspects 1 to 13, further comprising a cooling step of cooling the fiber web and / or the composite web between the bonding step and the entangling step, between the bonding step and the base sheet laminating step, or between the bonding step and the web laminating step, and / or cooling the laminate web between the web laminating step and the entangling step. (Aspect 15) A method for producing a nonwoven fabric according to any one of aspects 1 to 14, wherein the fiber web, the composite web, or the laminate web is not wound up into a roll at any time after the bonding step or before the entangling step. (Aspect 16) 16. The method for producing a nonwoven fabric according to any one of aspects 1 to 15, wherein in the partially entangled step, the less entangled portions are formed so that the width of the less entangled portions is greater than 5 mm and not greater than 50 mm. (Aspect 17) 17. The method for producing a nonwoven fabric according to any one of aspects 1 to 16, wherein the fiber web contains 55% by mass or more and 80% by mass or less of the adhesive fibers. (Aspect 18) 18. The method for producing a nonwoven fabric according to any one of embodiments 1 to 17, wherein the adhesive fiber comprises a core-sheath type composite fiber. (Aspect 19) 19. A method for producing a nonwoven fabric according to any one of aspects 1 to 18, further comprising, after the entangling step, another bonding step of bonding fibers together with the adhesive fiber. (Aspect 20) A nonwoven fabric comprising cellulosic fibers and adhesive fibers, The adhesive fibers include bonded portions between each other and / or bonded portions between the adhesive fibers and the cellulosic fibers, The cellulose-based fibers include entangled portions between each other and / or entangled portions between the cellulose-based fibers and the adhesive fibers, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, A nonwoven fabric, wherein the amount of fluff shedding on at least one surface of the nonwoven fabric is 1.5 mg or more and 20 mg or less, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff. (Aspect 21) A nonwoven fabric comprising a fiber layer containing cellulosic fibers and adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, The adhesive fibers include bonded portions between each other and / or bonded portions between the adhesive fibers and the cellulosic fibers, The cellulose-based fibers include entangled portions between each other and / or entangled portions between the cellulose-based fibers and the adhesive fibers, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, A nonwoven fabric, wherein the amount of fluff shedding on at least one surface of the nonwoven fabric is 1.5 mg or more and 20 mg or less, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff. (Aspect 22) 22. The nonwoven fabric according to claim 21, wherein the substrate sheet is a long-fiber nonwoven fabric, a wet-laid nonwoven fabric, or a net sheet. (Aspect 23) 23. The nonwoven fabric according to claim 21 or 22, wherein the base sheet is sandwiched in a cross section in the thickness direction by fibrous layers containing the cellulosic fibers and adhesive fibers. (Aspect 24) Aspect 24. The nonwoven fabric of any one of aspects 20 to 23, wherein the nonwoven fabric comprises 55% by mass or more and 80% by mass or less of the adhesive fibers. (Aspect 25) Aspect 25. The nonwoven fabric according to any one of aspects 20 to 24, wherein the adhesive fibers comprise core-sheath type composite fibers. (Aspect 26) Aspect 26. The nonwoven fabric according to any one of aspects 20 to 25, wherein the less entangled portions have a width of more than 5 mm and not more than 50 mm. (Aspect 27) A wiper comprising the nonwoven fabric according to any one of embodiments 20 to 26. (Aspect 28) A method for producing a nonwoven fabric containing adhesive fibers, comprising: In a fiber web containing the adhesive fibers, the method includes a bonding step of bonding fibers to each other with the adhesive fibers, and an entanglement step of entangling the fibers to each other after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a planar view, and the less entangled parts have a width of 2 mm or more and 50 mm or less. Method for manufacturing nonwoven fabric. (Aspect 29) A method for producing a nonwoven fabric comprising a fiber layer containing adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, comprising: In a fiber web containing the adhesive fibers, the method includes a bonding step of bonding fibers to each other with the adhesive fibers, and an entanglement step of entangling the fibers to each other after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a plan view and the less entangled parts have a width of 2 mm or more and 50 mm or less; a base sheet laminating step of laminating the base sheet on the fiber web to obtain a composite web, which is performed before or after the bonding step and before the entangling step; Method for manufacturing nonwoven fabric. (Aspect 30) A nonwoven fabric comprising adhesive fibers, The adhesive fibers include adhesive points between each other, The adhesive fibers include entangled portions, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, A nonwoven fabric, wherein the amount of fluff shedding on at least one surface of the nonwoven fabric is 1.5 mg or more and 20 mg or less, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff. (Aspect 31) A nonwoven fabric comprising a fiber layer containing adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, The adhesive fibers include adhesive points between each other, The adhesive fibers include entangled portions, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, A nonwoven fabric, wherein the amount of fluff shedding on at least one surface of the nonwoven fabric is 1.5 mg or more and 20 mg or less, as determined by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (manufactured by Inoac Corporation, trade name Malt Filter MF-30, thickness 5 mm) is attached to a rotating shaft so that the rotating shaft is positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) Place the disk on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft and rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) The above steps a) to e) are carried out for n=3 pieces of nonwoven fabric. The mass of the fallen fibers is measured for each of the three pieces of nonwoven fabric, and the average value is taken as the amount of fallen fluff. (Aspect 32) A wiper comprising the nonwoven fabric of embodiment 30 or 31. [Industrial Applicability]

[0209] The method for producing a nonwoven fabric according to the present disclosure involves subjecting a fiber web containing predetermined fibers to a bonding step and then to an entanglement treatment including a partial entanglement step, thereby producing a nonwoven fabric containing highly entangled portions in which the fibers are tightly entangled and less entangled portions in which the fibers have a high degree of freedom. Therefore, the method for producing a nonwoven fabric according to the present disclosure can produce a nonwoven fabric that is excellent in dirt collection, has greater strength than nonwoven fabrics produced using only an entanglement step, is easier to handle, and is less likely to pill, making it suitable for use as a wiper. [Explanation of symbols]

[0210] 10 Highly entangled part 20 Low intertwining area 100 nonwoven fabric

Claims

1. A method for producing a nonwoven fabric comprising cellulosic fibers and adhesive fibers, comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, The bonding step includes a hot air processing treatment of applying hot air to the fiber web, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a plan view, and the less entangled parts have a width of 2 mm or more and 50 mm or less. Method for manufacturing nonwoven fabric.

2. A method for producing a nonwoven fabric comprising a fiber layer containing cellulosic fibers and adhesive fibers, and a substrate sheet integrated with the fiber layer by entanglement of the fibers, comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled portions, in which the degree of entanglement between fibers is higher, and less entangled portions, in which the degree of entanglement between fibers is lower than that of the highly entangled portions, so that the highly entangled portions and the less entangled portions are alternately arranged in a planar view, and the less entangled portions have a width of 2 mm or more and 50 mm or less; a base sheet laminating step of laminating the base sheet on the fiber web to obtain a composite web, which is performed before or after the bonding step and before the entangling step, A method for producing a nonwoven fabric, wherein the bonding step includes a hot air processing treatment of applying hot air to the fiber web or the composite web.

3. The method for producing a nonwoven fabric according to claim 2, wherein the substrate sheet is a long-fiber nonwoven fabric, a wet-laid nonwoven fabric, or a mesh sheet.

4. A method for producing a nonwoven fabric comprising a fiber layer containing cellulosic fibers and adhesive fibers, and a substrate sheet integrated with the fiber layer by entanglement of the fibers, comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled portions, in which the degree of entanglement between fibers is higher, and less entangled portions, in which the degree of entanglement between fibers is lower than that of the highly entangled portions, so that the highly entangled portions and the less entangled portions are alternately arranged in a planar view, and the less entangled portions have a width of 2 mm or more and 50 mm or less; a base sheet laminating step of laminating the base sheet on the fiber web to obtain a composite web, which is performed before or after the bonding step and before the entangling step, The method for producing a nonwoven fabric, wherein the substrate sheet is a wet-laid nonwoven fabric or a mesh sheet.

5. 2. The method for producing a nonwoven fabric according to claim 1, further comprising a web laminating step, after the bonding step and before the entangling step, of laminating another fibrous web containing cellulosic fibers and adhesive fibers onto the fibrous web to obtain a laminated web.

6. The method for producing a nonwoven fabric according to any one of claims 2 to 4, further comprising a web laminating step, after the bonding step and before the entangling step, of laminating another fibrous web containing cellulosic fibers and adhesive fibers such that the base sheet is located between the fibrous web and the other fibrous web, to obtain a laminated web.

7. The method for producing a nonwoven fabric according to any one of claims 1 to 6, wherein the entangling step comprises a hydroentangling treatment.

8. The method for producing a nonwoven fabric according to any one of claims 1 to 7, wherein the entangling step includes a full-surface entangling step of entangling fibers across the entire fiber web, the entire composite web, or the entire laminate web, and the fiber web, the composite web, or the laminate web is subjected to the partial entangling step after the full-surface entangling step.

9. A method for producing a nonwoven fabric comprising cellulosic fibers and adhesive fibers, comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled portions, in which the degree of entanglement between fibers is higher, and less entangled portions, in which the degree of entanglement between fibers is lower than that of the highly entangled portions, so that the highly entangled portions and the less entangled portions are alternately arranged in a planar view, and the less entangled portions have a width of 2 mm or more and 50 mm or less; the entanglement step includes a full-surface entanglement step of entangling fibers throughout the entire fiber web, and the fiber web is subjected to the partial entanglement step after the full-surface entanglement step, The method for producing a nonwoven fabric, wherein the full-surface entanglement step and the partial entanglement step are both carried out by hydroentanglement, and the water pressure of the hydroentanglement step in the full-surface entanglement step is lower than the water pressure of the hydroentanglement step in the partial entanglement step.

10. 10. The method for producing a nonwoven fabric according to claim 9, wherein both the full-surface entanglement step and the partial entanglement step are carried out by a hydroentanglement treatment in which a water stream is sprayed onto only one surface of the fiber web, and the surface onto which the water stream is sprayed in the partial entanglement step is the opposite surface to the surface onto which the water stream is sprayed in the full-surface entanglement step.

11. A method for producing a nonwoven fabric comprising cellulosic fibers and adhesive fibers, comprising: In a fiber web containing the cellulosic fiber and the adhesive fiber, the method includes a bonding step of bonding fibers together with the adhesive fiber, and a entanglement step of entangling the fibers together after the bonding step, the entanglement step includes a partial entanglement step of forming highly entangled portions, in which the degree of entanglement between fibers is higher, and less entangled portions, in which the degree of entanglement between fibers is lower than that of the highly entangled portions, so that the highly entangled portions and the less entangled portions are alternately arranged in a planar view, and the less entangled portions have a width of 2 mm or more and 50 mm or less; the entanglement step includes a full-surface entanglement step of entangling fibers throughout the entire fiber web, and the fiber web is subjected to the partial entanglement step after the full-surface entanglement step, The entire entanglement step and the partial entanglement step are both carried out by hydroentanglement treatment, and the water pressure of the hydroentanglement treatment in the entire entanglement step is lower than the water pressure of the hydroentanglement treatment in the partial entanglement step, In the partially entangled portion, an open pattern is formed in the highly entangled portion.

12. The bonding step includes a hot air processing treatment of applying hot air to one surface of the fiber web or the composite web, The entanglement step includes a hydroentanglement treatment, The hydroentanglement treatment includes spraying a water stream first onto the surface of the fiber web or the composite web that has been hit with hot air, or spraying a water stream first onto the surface of the fiber web or the composite web that has been hit with hot air, before spraying a water stream onto the surface of the fiber web or the composite web that has not been hit with hot air. The manufacturing method according to any one of claims 1 to 11.

13. The method for producing a nonwoven fabric according to any one of claims 1 to 12, further comprising a cooling step of cooling the fiber web and / or the composite web between the bonding step and the entangling step, between the bonding step and the base sheet laminating step, or between the bonding step and the web laminating step, and / or cooling the laminate web between the web laminating step and the entangling step.

14. The method for producing a nonwoven fabric according to any one of claims 1 to 13, wherein the fiber web, the composite web, or the laminate web is not wound up into a roll at any time after the bonding step and before the entangling step.

15. The method for producing a nonwoven fabric according to any one of claims 1 to 14, further comprising, after the entangling step, another bonding step of bonding fibers together with the adhesive fiber.

16. A nonwoven fabric comprising cellulosic fibers and adhesive fibers, The adhesive fibers include bonded portions between each other and / or bonded portions between the adhesive fibers and the cellulosic fibers, The cellulose-based fibers include entangled portions between each other and / or entangled portions between the cellulose-based fibers and the adhesive fibers, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, The amount of fluff shedding on at least one surface of the nonwoven fabric is 1.5 mg or more and 20 mg or less in the following test, The adhesive intersection index A obtained by the following procedure is 1 / mm ２ ~60 pieces / mm ２ That is, nonwoven fabric. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (trade name Malt Filter MF-30, manufactured by Inoac Corporation, thickness 5 mm) was attached to a rotating shaft so that the rotating shaft was positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) The disk is placed on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft to rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) Repeat the above steps a) to e) for n = 3 pieces of nonwoven fabric. Measure the mass of the fallen fibers for each of the three pieces of nonwoven fabric, and calculate the average value to determine the amount of fluff that has fallen off. (Adhesive intersection index A) The front and back surfaces of the nonwoven fabric are observed under a scanning electron microscope (SEM, accelerating voltage: 10.0 kV, magnification: 100 times). The number of fiber bonding intersections per area is counted for the SEM images. The number of fiber adhesion intersections was counted for a total of six SEM images, three for each of the front and back surfaces of the nonwoven fabric, and the average value was taken as the number of fiber adhesion intersections I (unit: number / mm ２ ) The adhesive intersection ratio P (0≦P≦1) is calculated from the fineness (dtex) of the non-adhesive fibers and adhesive fibers constituting the nonwoven fabric and their mixing ratios (mass%) in the nonwoven fabric according to the following formula. [Equation 1] During the ceremony, α ｉ represents the mixing ratio (mass%) of the i-th non-adhesive fiber, x ｉ represents the fineness (dtex) of the i-th non-adhesive fiber, β ｊ represents the mixing ratio (mass%) of the jth adhesive fiber, y ｊ represents the fineness (dtex) of the jth adhesive fiber. From the number of adhesive intersections I and the adhesive intersection ratio P, the adhesive intersection index A (unit: pieces / mm ２ ) is calculated according to the following formula: Then the intersection index A = I / (P ２ )

17. A nonwoven fabric comprising a fiber layer containing cellulosic fibers and adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, The adhesive fibers include bonded portions between each other and / or bonded portions between the adhesive fibers and the cellulosic fibers, The cellulose-based fibers include entangled portions between each other and / or entangled portions between the cellulose-based fibers and the adhesive fibers, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, The adhesive intersection index A obtained by the following procedure is 1 / mm ２ ~60 pieces / mm ２ and A nonwoven fabric, wherein the amount of fluff shedding on at least one surface of the nonwoven fabric is 1.5 mg or more and 20 mg or less, as measured by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (trade name Malt Filter MF-30, manufactured by Inoac Corporation, thickness 5 mm) was attached to a rotating shaft so that the rotating shaft was positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) The disk is placed on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft to rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) Repeat steps a) to e) above for n=3 pieces of nonwoven fabric. Measure the mass of the fallen fibers for each of the three pieces of nonwoven fabric, and calculate the average value to determine the amount of fluff that has fallen off. (Adhesive intersection index A) The front and back surfaces of the nonwoven fabric are observed under a scanning electron microscope (SEM, accelerating voltage: 10.0 kV, magnification: 100 times). The number of fiber bonding intersections per area is counted for the SEM images. The number of fiber adhesion intersections was counted for a total of six SEM images, three for each of the front and back surfaces of the nonwoven fabric, and the average value was taken as the number of fiber adhesion intersections I (unit: number / mm ２ ) The adhesive intersection ratio P (0≦P≦1) is calculated from the fineness (dtex) of the non-adhesive fibers and adhesive fibers constituting the nonwoven fabric and their mixing ratios (mass%) in the nonwoven fabric according to the following formula. [Equation 2] During the ceremony, α ｉ represents the mixing ratio (mass%) of the i-th non-adhesive fiber, x ｉ represents the fineness (dtex) of the i-th non-adhesive fiber, β ｊ represents the mixing ratio (mass%) of the jth adhesive fiber, y ｊ represents the fineness (dtex) of the jth adhesive fiber. From the number of adhesive intersections I and the adhesive intersection ratio P, the adhesive intersection index A (unit: pieces / mm ２ ) is calculated according to the following formula: Then the intersection index A = I / (P ２ )

18. The nonwoven fabric according to claim 17, wherein the substrate sheet is a long-fiber nonwoven fabric, a wet-laid nonwoven fabric, or a net sheet.

19. A nonwoven fabric comprising a fiber layer containing cellulosic fibers and adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, The adhesive fibers include bonded portions between each other and / or bonded portions between the adhesive fibers and the cellulosic fibers, The cellulose-based fibers include entangled portions between each other and / or entangled portions between the cellulose-based fibers and the adhesive fibers, The nonwoven fabric includes a highly entangled portion in which the degree of entanglement between fibers is higher and a low entangled portion in which the degree of entanglement between fibers is lower, the highly entangled portions and the less entangled portions are alternately arranged in the CD direction in a plan view, The width of the less entangled portion is 2 mm or more and 50 mm or less, the base sheet is a long-fiber nonwoven fabric, a wet-laid nonwoven fabric, or a mesh sheet, A nonwoven fabric, wherein the amount of fluff shedding on at least one surface of the nonwoven fabric is 1.5 mg or more and 20 mg or less, as measured by the following test. (Lifting amount measurement test) a) A disk (70 mm diameter, 350 g) covered with urethane foam (trade name Malt Filter MF-30, manufactured by Inoac Corporation, thickness 5 mm) was attached to a rotating shaft so that the rotating shaft was positioned 20 mm off from the center of the disk. b) The same urethane foam as above is laid on the table, and the nonwoven fabric is fixed on top of it so that one side of the nonwoven fabric is exposed. c) The disk is placed on the nonwoven fabric, with the only load applied to the nonwoven fabric being the disk's own weight. d) Rotate the rotating shaft to rotate the disk over the nonwoven fabric. Three sets of rotations are performed, each set consisting of three clockwise rotations and three counterclockwise rotations. The rotation speed is approximately 3 seconds per rotation. e) After three sets of rotation, collect the fibers that have fallen off the nonwoven fabric and adhered to the surface of the urethane foam covering the disk. f) Repeat steps a) to e) above for n=3 pieces of nonwoven fabric. Measure the mass of the fallen fibers for each of the three pieces of nonwoven fabric, and calculate the average value to determine the amount of fluff that has fallen off.

20. The nonwoven fabric according to any one of claims 17 to 19, wherein the base sheet is sandwiched between fiber layers containing the cellulosic fibers and adhesive fibers in a cross section in the thickness direction.

21. The nonwoven fabric according to any one of claims 16 to 20, wherein the nonwoven fabric comprises 55% by mass or more and 80% by mass or less of the adhesive fibers.

22. The nonwoven fabric according to any one of claims 16 to 21, wherein the adhesive fiber comprises a core-sheath type composite fiber.

23. The nonwoven fabric according to any one of claims 16 to 22, wherein the width of the less entangled portion is greater than 5 mm and not greater than 50 mm.

24. A wiper comprising the nonwoven fabric according to any one of claims 16 to 23.

25. A method for producing a nonwoven fabric containing adhesive fibers, comprising: In a fiber web containing the adhesive fibers, the method includes a bonding step of bonding fibers to each other with the adhesive fibers, and an entanglement step of entangling the fibers to each other after the bonding step, The bonding step includes a hot air processing treatment of applying hot air to the fiber web, the entanglement step includes a partial entanglement step of forming highly entangled parts, in which the degree of entanglement between fibers is higher, and less entangled parts, in which the degree of entanglement between fibers is lower than that of the highly entangled parts, so that the highly entangled parts and the less entangled parts are alternately arranged in a plan view, and the less entangled parts have a width of 2 mm or more and 50 mm or less. Method for manufacturing nonwoven fabric.

26. A method for producing a nonwoven fabric comprising a fiber layer containing adhesive fibers, and a base sheet integrated with the fiber layer by entanglement of the fibers, comprising: The fiber web includes a bonding step of bonding fibers together with the adhesive fibers, and a entanglement step of entangling the fibers together after the bonding step, and the entanglement step includes a partial entanglement step of forming highly entangled sections in which the degree of entanglement of fibers is higher and less entangled sections in which the degree of entanglement of fibers is lower than that of the highly entangled sections, so that the highly entangled sections and the less entangled sections are alternately arranged in a plan view, and the width of the less entangled sections is 2 mm or more and 50 mm or less, a base sheet laminating step of laminating the base sheet on the fiber web to obtain a composite web, which is performed before or after the bonding step and before the entangling step, The bonding step includes a hot air processing treatment of applying hot air to the fiber web or the composite web. Method for manufacturing nonwoven fabric.

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