Nonwoven fabric containing cellulose fibers

Abstract

Provided is unwoven fabric having high handleability and adherability in a wet state. The unwoven fabric according to the present invention includes cellulose fibers, wherein a high fiber level region in which the amount of amassed fibers is large and a low fiber level region in which the amount of amassed fibers is low relative to the high fiber level region exhibit a herringbone pattern. The unwoven fabric is characterized in that: the friction coefficient of the front surface of the unwoven fabric is different from the friction coefficient of the back surface of the unwoven fabric in a dry state; and when the surface with a smaller friction coefficient is referred to as a front surface, and the surface with a larger friction coefficient is referred to as a back surface, the difference between the friction coefficients calculated by the following formula is 10%-80%: friction coefficient difference (%) = {(friction coefficient of back surface - friction coefficient of front surface) / friction coefficient of front surface} × 100.

Description

[Technical field]

[0001] The present invention relates to a nonwoven fabric containing cellulose fibers. More specifically, the present invention relates to a nonwoven fabric containing cellulose fibers that has high handleability and adhesion in a wet state. [Background technology]

[0002] Examples of nonwoven fabrics with excellent liquid absorbency include cellulose fiber nonwoven fabrics made of cellulose fibers such as cotton, pulp, rayon, etc. Cellulose fiber nonwoven fabrics are widely used for applications that absorb liquids, such as face masks for beauty, wet wipers for people and objects, and dry wipers for wiping off liquids.

[0003] It is known that in order to improve the handling property of such cellulose fiber nonwoven fabrics in a wet state and to impart design, a herringbone pattern is imparted to the surface of the nonwoven fabric. For example, the following Patent Document 1 proposes that a fiber material is subjected to a hydroentanglement treatment on a herringbone weave support to impart a herringbone pattern to improve the balance of strength in the warp and weft directions and the feel in the hand. In addition, the following Patent Document 2 proposes that a herringbone pattern is imparted to the nonwoven fabric with a herringbone pattern to improve the separation between the nonwoven fabrics and to prevent the phenomenon of "slip", in which the next nonwoven fabric is taken out together with the stacked nonwoven fabrics when they are taken out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3559533 [Patent Document 2] Patent No. 4548814 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the nonwoven fabrics of the above-mentioned conventional techniques have the following problems. When a nonwoven fabric having a herringbone pattern is slid along a target surface, the slipperiness of the nonwoven fabric against the target surface and the slipperiness of the nonwoven fabric against the operating hand are the same, so that the nonwoven fabric cannot be slid along the target surface without slipping from the operating hand. Therefore, when used as a face mask, even if the nonwoven fabric is slid along the skin surface to fine-tune the position of the face mask after it has been placed in close contact with the skin, the nonwoven fabric also slips from the operating hand, making the nonwoven fabric difficult to operate. Also, when used as a wiper, even if the nonwoven fabric is slid along the target surface to wipe off dirt, the nonwoven fabric also slips from the operating hand, making the nonwoven fabric difficult to operate.

[0006] In view of the above problems, an object of the present invention is to provide a nonwoven fabric containing cellulose fibers that has high handleability and adhesion in a wet state. [Means for solving the problem]

[0007] As a result of intensive research and repeated experiments to solve the above problems, the inventors unexpectedly discovered that by adjusting the difference in friction coefficient between the front and back surfaces of a nonwoven fabric containing cellulose fibers having a high fiber content region with a herringbone pattern to 10% or more, the nonwoven fabric has high handleability in a wet state and further high adhesion. This has led to the completion of the present invention.

[0008] That is, the present invention is as follows. [1] A nonwoven fabric containing cellulose fibers, which has a herringbone pattern formed by a high fiber content region having a large amount of accumulated fibers and a low fiber content region having a relatively small amount of accumulated fibers compared to the high fiber content region, In a dry state, when the friction coefficients of the front and back surfaces of the nonwoven fabric are different, with the surface with a smaller friction coefficient being the front surface and the surface with a larger friction coefficient being the back surface, the following formula is satisfied: Difference in friction coefficient (%) = {(friction coefficient of back surface - friction coefficient of front surface) / friction coefficient of front surface} x 100 The nonwoven fabric is characterized in that the difference in friction coefficient calculated by the above formula is 10% or more and 80% or less. [2] The nonwoven fabric described in [1] above, wherein the cellulose fiber content in the nonwoven fabric is 80% by weight or more and 100% by weight or less. [3] The nonwoven fabric according to [1] or [2], wherein the cellulose fibers are continuous long fibers. [4] The nonwoven fabric according to any one of [1] to [3] above, wherein the coefficient of friction of the front surface of the nonwoven fabric in a dry state is 0.05 or more and 0.3 or less. [5] The nonwoven fabric according to any one of [1] to [4] above, wherein the surface roughness of the front surface of the nonwoven fabric in a dry state is 10 μm or more and 60 μm or less. [6] The nonwoven fabric has a basis weight of 10 g / m 2 More than 150g / m 2 The nonwoven fabric according to any one of the above [1] to [5], having a thickness of 0.1 mm or more and 1.0 mm or less. [7] The nonwoven fabric according to any one of [1] to [6], wherein the initial tensile strength of the nonwoven fabric in a longitudinal direction in a wet state is 0.1 N / 50 mm or more and 3.0 N / 50 mm or less. [8] The nonwoven fabric according to any one of [1] to [7] above, wherein the coefficient of friction of the back surface of the nonwoven fabric in a dry state is 0.05 or more and 0.35 or less. [9] The nonwoven fabric according to any one of [1] to [8], wherein the difference in the friction coefficient is 30% or more and 50% or less.

[10] The nonwoven fabric according to any one of [1] to [9], wherein the coefficient of friction of the front surface of the nonwoven fabric in a dry state is 0.13 or more and 0.17 or less, and the coefficient of friction of the back surface of the nonwoven fabric in a dry state is 0.17 or more and 0.35 or less.

[11] The nonwoven fabric according to any one of [1] to

[10] above, wherein the content of cellulose fibers in the nonwoven fabric is 95% by weight or more and 100% by weight or less.

[12] A face mask comprising the nonwoven fabric according to any one of [1] to

[11] .

[13] A cosmetic toner pad comprising the nonwoven fabric according to any one of [1] to

[11] above. Effect of the Invention

[0009] The nonwoven fabric containing the cellulose fibers of the present invention has excellent handleability in a wet state, in particular the ease of separation of the nonwoven fabric when unfolding it from a folded state, and the ease of operation of the nonwoven fabric when sliding it along a target surface, and also has high adhesion to the target surface. Therefore, the nonwoven fabric can be suitably used, for example, as a substrate for wet sheets such as face masks, toner pads, wet wipers, and dry wipers. [Brief description of the drawings]

[0010] [Figure 1] 1 is a photograph, instead of a drawing, for illustrating a herringbone pattern in a nonwoven fabric containing cellulose fibers of the present embodiment, which is composed of a high fiber content region (A) and a low fiber content region (B). [Diagram 2] 1 is a photograph, instead of a drawing, for illustrating a herringbone twill pattern in a nonwoven fabric containing cellulose fibers of the present embodiment. [Diagram 3] 1 is a photograph, instead of a drawing, for illustrating a herringbone twill pattern in a nonwoven fabric containing cellulose fibers of the present embodiment. [Figure 4] 1 is a photograph, instead of a drawing, of a special herringbone twill net used to obtain the cellulose fiber nonwoven fabric of Example 1 (woven in such a way that the meridians cross seven latitudes). [Diagram 5] 1 is a photograph, instead of a drawing, of the cellulose fiber nonwoven fabric (herringbone pattern) obtained in Example 3. [Figure 6] 2 is a photograph, instead of a drawing, of the cellulose fiber nonwoven fabric (mesh pattern) obtained in Comparative Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail. One embodiment of the present invention is a nonwoven fabric containing cellulose fibers, which has a herringbone pattern formed by a high fiber content region having a large amount of accumulated fibers and a low fiber content region having a relatively small amount of accumulated fibers compared to the high fiber content region, In a dry state, when the friction coefficients of the front and back surfaces of the nonwoven fabric are different, with the surface with a smaller friction coefficient being the front surface and the surface with a larger friction coefficient being the back surface, the following formula is satisfied: Difference in friction coefficient (%) = {(friction coefficient of back surface - friction coefficient of front surface) / friction coefficient of front surface} x 100 The nonwoven fabric is characterized in that the difference in friction coefficient calculated by the above formula is 10% or more and 80% or less.

[0012] The cellulose fibers contained in the nonwoven fabric of this embodiment are not particularly limited, and examples thereof include regenerated cellulose fibers such as cuprammonium rayon, viscose rayon, Tencel (Lyocell), and polynosic, and natural cellulose fibers such as cotton, pulp, and hemp. Among them, regenerated cellulose fibers are preferred, more preferably cuprammonium rayon and Tencel (Lyocell), and particularly preferably cuprammonium rayon. Regenerated cellulose fibers have higher liquid absorption properties and lower stiffness of threads in a wet state than natural cellulose, so that when used as a wet sheet, the nonwoven fabric is easily bent and has high adhesion. In addition, if the amount of cellulose fibers contained in the nonwoven fabric is small, the adhesion and liquid absorption are insufficient. The content of cellulose fibers in the nonwoven fabric is preferably 80% by weight or more, more preferably 90% by weight or more, even more preferably 95% by weight or more, and most preferably 100% by weight. In this specification, the term "cellulose fiber nonwoven fabric" refers to a nonwoven fabric having a cellulose fiber content of 80% by weight or more.

[0013] The cellulose fibers contained in the nonwoven fabric of this embodiment may be continuous long fibers or short fibers, but continuous long fibers are preferred. Continuous long fibers have a lower degree of fiber freedom than short fibers, and are more likely to form fiber bundles along the recesses of the lower layer net during hydroentanglement treatment, which tends to increase the unevenness of the surface of the nonwoven fabric that contacts the lower layer net, making it easier for the friction coefficient to differ between the front and back of the nonwoven fabric. Furthermore, continuous long fibers are preferred because they have a higher proportion of fibers oriented in the planar direction of the nonwoven fabric than in the thickness direction, and have a larger area of ​​fibers that contact the target surface, resulting in high adhesion. In this specification, the term "continuous long fibers" refers to fibers with a fiber length of 50 mm or more.

[0014] The structure of the cellulose fiber nonwoven fabric of this embodiment will be described with reference to Figs. 1 to 3. However, the structure of the cellulose fiber nonwoven fabric of this embodiment is not limited to Figs. 1 to 3. The cellulose fiber nonwoven fabric is composed of a high fiber content region (A) and a low fiber content region (B). Here, the high fiber content region refers to a region with a large amount of accumulated fibers, and the low fiber content region refers to a region with a relatively small amount of accumulated fibers compared to the high fiber content region, and the two are defined by a relative relationship. In the high fiber content region, more fibers are accumulated than in the low fiber content region, and the fibers are present in bundles and are convex in the thickness direction. Due to the presence of the high fiber content region convex in the thickness direction, when the nonwoven fabric is folded, the convex parts come into contact with each other, making the nonwoven fabric highly separable, and the sheet is easy to handle even in a wet state. Furthermore, when the stacked nonwoven fabrics are taken out, the convex high fiber content regions come into contact with each other, making the nonwoven fabric highly separable, and the sheet is easy to take out even in a wet state.

[0015] The high fiber content regions, in which fibers are accumulated in bundles, form a certain pattern, which creates a pattern in the nonwoven fabric. In this specification, the term "herringbone pattern" refers to a pattern formed by the intersection of a high fiber content region (A-1) inclined at 3° to 87° to the vertical direction and a high fiber content region (A-2) inclined at -3° to -87° to the vertical direction, as exemplified in Fig. 1. The two high fiber content regions are obliquely present at different angles to each other, resulting in multiple intersections (C) between the high fiber content regions. In the cellulose fiber nonwoven fabric of this embodiment, many fibers self-bond at the intersections of the high fiber content regions, which increases the strength of the entire nonwoven fabric, resulting in high rigidity and excellent handling feel. The "vertical direction" here refers to the direction along the line direction of the manufacturing process, and refers to the same direction as the direction of progression of the period when the fibers that make up the cellulose fiber nonwoven fabric draw a sine wave. The "horizontal direction" is the width direction of the product, and is the direction perpendicular to the "vertical direction". Not only cellulose fibers, but all nonwoven fabrics have constituent fibers oriented in the line direction (vertical direction) of the manufacturing process, so the nonwoven fabric tends to stretch easily in the horizontal direction, that is, the initial tensile strength of the nonwoven fabric in the horizontal direction tends to be small. If the line direction of the nonwoven fabric is unknown, the direction with the smallest initial tensile strength may be defined as the horizontal direction, and the direction perpendicular to the horizontal direction as the vertical direction.

[0016] The inclination angle of both high fiber content regions with respect to the warp direction is preferably 3° to 87° or -3° to -87°, and more preferably 5° to 30° or -5° to -30° from the viewpoint of the balance of warp and weft strength. If the inclination angle with respect to the warp direction is too small, both high fiber content regions run almost parallel to the warp direction, resulting in fewer intersections between the two high fiber content regions and insufficient strength of the entire nonwoven fabric, which is not preferred. If the inclination angle with respect to the warp direction is too large, both high fiber content regions run almost parallel to the weft direction, resulting in fewer intersections between the two high fiber content regions and insufficient strength of the entire nonwoven fabric, which is not preferred.

[0017] As one of the preferred embodiments of the present invention, there is a nonwoven fabric in which cellulose fibers are subjected to hydroentanglement treatment on a herringbone weave net. However, the present invention is not limited thereto. A herringbone weave net is a net in which meridians and latitude lines are kept at a certain interval and cross each other by two or more lines, and examples thereof include a pattern in which the meridians cross the latitude lines by two lines above and two lines below, and a pattern in which the meridians cross the latitude lines by two lines above and one line below. In order for the nonwoven fabric to form the herringbone weave pattern described above, it is more preferable to use a net in which the meridians cross five or more latitude lines. This is because if a net in which the meridians cross the latitude lines by four lines or less is used, it becomes difficult to set the inclination angle of the two high fiber content regions described above.

[0018] The cellulose fiber nonwoven fabric of this embodiment has high separability due to the high fiber content region of the herringbone pattern, and can be easily opened from a folded state. Furthermore, by controlling the manufacturing method such as spinning and water flow entanglement conditions, a difference in friction coefficient between the front and back is created, which makes the nonwoven fabric excellent in operability when sliding in a direction parallel to the target surface, and also excellent in adhesion to the target surface.

[0019] The front surface of the cellulose fiber nonwoven fabric in this embodiment refers to the surface with the smaller frictional resistance of the two surfaces of the nonwoven fabric, the front and back, and the back surface refers to the surface with the larger frictional resistance. Because there is a difference in frictional resistance between the surface with the smaller friction coefficient (front surface) and the target surface to be brought into contact with, and the surface with the larger friction coefficient (back surface) and the hand operating the nonwoven fabric, the nonwoven fabric is easily caught by the hand operating the nonwoven fabric and easily slips against the target surface, making it easy to operate the nonwoven fabric. Furthermore, since the front surface has a small friction coefficient, i.e., a smooth shape, the contact area with the target surface is large and the adhesion is high.

[0020] The friction coefficients of the front and back of the cellulose fiber nonwoven fabric in the dry state of this embodiment differ by 10% or more, preferably by 15% or more, more preferably by 20% or more, and even more preferably by 30% or more. If the difference in the friction coefficients of the front and back is too small, the difference in the slipperiness of the nonwoven fabric is not apparent, making it difficult to operate. Furthermore, the difference in the friction coefficients of the front and back of the cellulose fiber nonwoven fabric in the dry state of this embodiment is 80% or less, preferably 60% or less, and more preferably 50% or less. If the friction coefficient is too high, the nonwoven fabric will catch too strongly on the operating hand, making it difficult to attach the nonwoven fabric to the target surface, which is undesirable as it reduces operability. The difference in the friction coefficient between the front and back surfaces in a dry state is calculated using the following formula: Difference in friction coefficient (%) = {(friction coefficient of back surface - friction coefficient of front surface) / friction coefficient of front surface ×} 100 It is calculated as follows. In this specification, the term "dry state" refers to a state in which the material is dried at 105°C until a constant mass is reached, and then allowed to stand in a thermostatic chamber at 20°C and 65% RH for 16 hours or more.

[0021] Furthermore, if the difference in friction coefficient between the front and back surfaces in a dry state is 30% or more and 50% or less, the difference in slipperiness between the front and back nonwoven fabrics tends to be maintained even when the wet sheet continues to dry.

[0022] In addition, when the cellulose fiber nonwoven fabric of this embodiment is used as a face mask, the surface of the nonwoven fabric contacts the skin surface of the face or the like into which the cosmetic liquid is to be permeated, and the back surface of the nonwoven fabric contacts the hand that manipulates the face mask. Since the frictional resistance between the back surface of the nonwoven fabric and the hand is greater than the frictional resistance between the skin surface of the face or the like and the front surface of the nonwoven fabric, the nonwoven fabric moves together with the hand, making it easy to fine-tune the operation to attach the face mask neatly to the face. Furthermore, the front surface of the nonwoven fabric that contacts the skin surface of the face or the like has a low friction coefficient and a smooth shape with little roughness, so that it adheres well to the skin surface of the face or the like, and the cosmetic liquid can be efficiently permeated.

[0023] When the cellulose fiber nonwoven fabric of this embodiment is used as a wiper, the surface to be wiped is in contact with the front surface of the nonwoven fabric, and the back surface of the nonwoven fabric is in contact with the hand operating the wiper. Since the frictional resistance between the back surface of the nonwoven fabric and the hand operating the wiper is greater than the frictional resistance between the surface to be wiped and the front surface of the nonwoven fabric, the hand and the nonwoven fabric move together, making it easy to wipe. Furthermore, the front surface of the nonwoven fabric in contact with the target surface has a low friction coefficient and a smooth shape with little roughness, so it has high adhesion to the target surface and can effectively wipe off dirt on the target surface.

[0024] When the cellulose fiber nonwoven fabric of this embodiment is used as a cosmetic toner pad (hereinafter also referred to as a pad), when scraping off keratin and dirt from pores on the skin of the face, etc., the back surface of the nonwoven fabric is attached so that it comes into contact with the skin surface of the face, etc., and the skin is rubbed with the nonwoven fabric. Since the unevenness of the back surface is large, the fibers can enter the fine unevenness of pores, etc., and effectively scrape off dirt. After that, when transferring cosmetic liquid to the skin and penetrating the cosmetic ingredients, the nonwoven fabric is attached so that the front surface of the nonwoven fabric comes into contact with the skin surface of the face, etc., and the nonwoven fabric is slid on the skin surface. Since the frictional resistance between the back surface of the nonwoven fabric and the hand is greater than the frictional resistance between the skin surface and the front surface of the nonwoven fabric, the nonwoven fabric moves together with the hand, making it easy to slide the pad. Furthermore, the front surface of the nonwoven fabric that comes into contact with the skin surface has a low friction coefficient and a smooth shape with little roughness, so that it adheres well to the skin surface of the face, etc., and it is possible to efficiently penetrate the cosmetic liquid. In order to impart different functionalities to the front and back surfaces of pads, nonwoven fabrics are sometimes laminated and used as the base fabric for the pad. However, the cellulose fiber nonwoven fabric of the present embodiment is a single layer with different functions on the front and back surfaces, so it can be used as a pad as a single layer without lamination, making it possible to save the effort of processing.

[0025] The coefficient of friction of the front surface of the cellulose fiber nonwoven fabric in the dry state of this embodiment is preferably 0.3 or less, more preferably 0.25 or less, even more preferably 0.20 or less, and particularly preferably 0.17 or less. When the coefficient of friction of the front surface is within the above range, the surface of the nonwoven fabric is less rough and has good adhesion to the target surface. In addition, when used as a face mask, the coefficient of friction of the front surface is preferably 0.05 or more, more preferably 0.08 or more, even more preferably 0.10 or more, and particularly preferably 0.13 or more, from the viewpoint of the nonwoven fabric being appropriately attached to the skin surface to be adhered without slipping off.

[0026] The surface roughness of the front surface of the cellulose fiber nonwoven fabric of this embodiment in a dry state is preferably 60 μm or less, more preferably 55 μm or less, and even more preferably 50 μm or less. When the surface roughness is within the above range, the unevenness of the front surface of the nonwoven fabric is small, the adhesion to the target surface is good, and the touch is good with less prickly feeling when it comes into contact with the skin. In addition, from the viewpoint of the front surface of the nonwoven fabric having moderate unevenness for the separation of the nonwoven fabric when unfolding the folded nonwoven fabric, the surface roughness of the front surface is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 25 μm or more.

[0027] In addition, the coefficient of friction of the back surface of the cellulose fiber nonwoven fabric of this embodiment in a dry state is preferably 0.05 or more, more preferably 0.10 or more, even more preferably 0.15 or more, and particularly preferably 0.17 or more. When the coefficient of friction of the back surface is within the above range, the unevenness of the nonwoven fabric is clearly generated, and the separation property of the nonwoven fabric is improved. Furthermore, from the viewpoint of the feel when the nonwoven fabric is pinched by hand, the coefficient of friction of the back surface is preferably 0.35 or less, more preferably 0.30 or less, and even more preferably 0.25 or less.

[0028] The weight of the cellulose fiber nonwoven fabric of this embodiment is preferably 10 g / m 2 More preferably, 15 g / m 2 More preferably, 20 g / m 2 When the basis weight is within the above range, the fibers in the high fiber content region are sufficiently accumulated, and the herringbone pattern is clearly expressed. In addition, the basis weight of the cellulose fiber nonwoven fabric of this embodiment is preferably 150 g / m 2 Less than 120 g / m 2 Less than 90 g / m, more preferably 2 When the fiber amount in the low fiber amount region is in the above range, the fiber amount is appropriately small, and the herringbone pattern appears clearly.

[0029] The thickness of the cellulose fiber nonwoven fabric of this embodiment is preferably 0.1 mm or more, more preferably 0.15 mm or more, and even more preferably 0.2 mm or more. Within the above range, the nonwoven fabric is easy to grip with hands and has high separability. Furthermore, the thickness of the cellulose fiber nonwoven fabric of this embodiment is preferably 1.0 mm or less, more preferably 0.8 mm or less, and even more preferably 0.6 mm or less. Within the above range, the rigidity of the nonwoven fabric is sufficiently low, and it adheres closely to the target surface while following the unevenness and curved surface of the target surface.

[0030] The initial tensile strength in the longitudinal direction of the cellulose fiber nonwoven fabric of this embodiment in a wet state is preferably 0.1 N / 50 mm or more, more preferably 0.2 N / 50 mm or more, and even more preferably 0.3 N / 50 mm or more. Within the above range, the nonwoven fabric does not stretch even when a small force is applied, so the deformation of the nonwoven fabric is small. Furthermore, the initial tensile strength in the longitudinal direction of the cellulose fiber nonwoven fabric of this embodiment in a wet state is preferably 3.0 N / 50 mm or less, more preferably 2.0 N / 50 mm or less, and even more preferably 1.5 N / 50 mm or less. Within the above range, even if there are small irregularities or curves on the surface to which the nonwoven fabric is to be attached, it is possible to make the nonwoven fabric conform to the irregularities or curves by simply applying an appropriate force to stretch the nonwoven fabric. In this specification, the term "wet state" refers to a state in which the nonwoven fabric is immersed in grade 3 water conforming to ISO3696 at 20°C ± 2°C for 1 hour.

[0031] The method for producing the cellulose fiber nonwoven fabric of this embodiment will be described below. In the manufacture of nonwoven fabrics, the pattern formed by the high fiber content regions can be changed by changing the shape of the lower layer net that the spun fibers are laminated in. Furthermore, by changing the speed of the lower layer net, it is possible to change the clarity of the pattern of the nonwoven fabric, the friction coefficient of the nonwoven fabric, and the strength of the nonwoven fabric. For example, one method of making the high fiber content region clear is to slow down the speed of the lower net and lengthen the time for punching, which is the patterning process. However, when a herringbone weave net is used for the lower net, if the punching time is lengthened, the nonwoven fabric will bite too strongly into the lower net, resulting in large unevenness on both the front and back sides of the nonwoven fabric, making it difficult to achieve a difference in friction coefficient between the front and back sides of 10% or more. In this case, since there is no difference in the slipperiness of the front and back sides, it is observed that the operability becomes poor and the adhesion to the target surface tends to decrease. Furthermore, the uneven accumulation of fibers becomes large, and the open holes in the low fiber content region tend to become large, which deteriorates the strength of the nonwoven fabric. In this way, it is difficult to achieve excellent adhesion and strength of the nonwoven fabric while maintaining the ease of use required of a nonwoven fabric.

[0032] In the manufacturing method of the cellulose fiber nonwoven fabric of this embodiment, the nozzle that ejects the high-pressure water stream is angled to make holes and adjust the bite of the nonwoven fabric into the lower net, making it possible to clearly define the high fiber content area of ​​the herringbone pattern while making the difference in friction coefficient between the front and back equal to or greater than a predetermined value. This allows the nonwoven fabric to exhibit excellent separation properties and adhesion to the target surface, and unexpectedly improves the operability when sliding the nonwoven fabric parallel to the target surface. The "perforation" referred to here is a process in which the fibers are entangled by penetrating the spun sheet with a high-pressure water jet, needles, etc. Perforation can improve the strength of the nonwoven fabric, improve the texture of the nonwoven fabric, and form a pattern.

[0033] One of the preferred embodiments of the method for drilling holes in a cellulose fiber nonwoven fabric of this embodiment is to install a drilling nozzle obliquely with respect to the lower layer net and to blow an entanglement water flow obliquely with respect to the thickness direction of the nonwoven fabric. By blowing an entanglement water flow obliquely, a large convex portion is generated on the back surface of the nonwoven fabric that bites into the lower layer net of the herringbone weave. On the other hand, since the entanglement water flow penetrates obliquely with respect to the thickness direction of the nonwoven fabric, the area of ​​the openings on the surface of the nonwoven fabric becomes smaller, and the convex portion on the opposite surface (front surface) becomes smaller. Furthermore, the openings present in the low fiber content region become smaller, and the entanglement force between the fibers of the nonwoven fabric is increased, so that the strength of the nonwoven fabric can be maintained. However, the drilling method is not limited to this. For example, the length between the drilling nozzle and the lower layer net may be changed, or the lower layer net may proceed in a curved line with respect to the drilling nozzle. EXAMPLES

[0034] EXAMPLES The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited to these examples. First, the measurement methods used in the examples and comparative examples will be described. In this case, the nonwoven fabric that had already been immersed in a liquid such as a chemical solution was washed once with pure water, dried at 105°C until a constant mass was reached, and then left in a thermostatic chamber at 20°C and 65% RH for 16 hours or more before measurement in the dry state.

[0035] (1) Friction coefficient (-) A 3cm x 27cm nonwoven fabric was rubbed vertically against a metal friction element (10mm square piano wire, standard specification) and the front side of the sample and the back side, which is the opposite side, and the average friction coefficient MIU was measured using a friction tester (KES-SE) manufactured by Kato Tech Co., Ltd. The measurement conditions were load: 25g, speed: 1mm / s, and the measurement was performed three times, and the average value was taken as the friction coefficient (-). If a sample size suitable for the above measurement method cannot be obtained, a sample measuring 3 cm x 5 cm or more can be used to measure by attaching a patch to both ends.

[0036] (2) Surface roughness in a dry state (μm) (DRY surface roughness Sa (μm)) Surface roughness is the average of the absolute height values ​​of each point in the measurement area. Here, "height" refers to the distance from the reference surface to each point on the measurement surface. The 3D shape of a 5 cm square nonwoven fabric in a dry state was measured using a Keyence One-Shot 3D Shape Measuring Instrument (VR-3000), and the surface roughness of the nonwoven fabric in a dry state was measured under the following conditions. The measurement was performed three times, and the average value was taken as the surface roughness (μm). (Measurement conditions) 3D shape measurement magnification: 12x Pre-measurement processing: Surface shape correction Surface roughness measurement area: All areas S Filter: None L Filter: None

[0037] (3) Weight (g / m 2 ) 0.05m 2 The cellulose nonwoven fabric having the above area is dried at 105°C until it reaches a constant mass, then left in a thermostatic chamber at 20°C and 65% RH for 16 hours or more, and its mass is measured. 2 The measurement was carried out five times, and the average value was calculated as the basis weight (g / m 2 ) was decided.

[0038] (4) Thickness (mm) The nonwoven fabric in a dry state was measured at a load of 1.96 kPa in a thickness test conforming to JIS-L 1096. The measurement was performed 20 times, and the average value was taken as the thickness (mm).

[0039] (5) Initial tensile strength in wet condition (N / 50mm) A wet nonwoven fabric measuring 5cm x 10cm was measured at a constant speed of 300mm / min using an Orientec Tensilon tensile tester, and the strength of the nonwoven fabric at 5% elongation in the machine direction (MD) was measured. The measurement was performed five times, and the average value was taken as the initial tensile strength (N / 50mm). If a sample size conforming to the above measurement method cannot be obtained, a size of 5cm x 5cm can be used for comparison.

[0040] (6) Fiber diameter (μm) The nonwoven fabric was observed at a magnification of 10,000 times using a scanning electron microscope, JEOL Ltd. JSM-6380, and 50 fibers were randomly selected and the average value of the measurements was taken as the fiber diameter.

[0041] (7) Separability of nonwoven fabric A 15 cm square nonwoven fabric was folded in half with the back side facing inward, then folded in half at a right angle to make a quarter, and soaked in 25 ml of water. Using this sample, the ease of spreading the nonwoven fabric was judged based on the following evaluation criteria. The results of the judgments of 10 monitors were averaged, and the average value was calculated as an index of the separability of the nonwoven fabric. An average score of less than 3 points was deemed to indicate that the nonwoven fabric had poor separability. <Evaluation criteria> 5 points: Takes very little time and can be spread quickly 4 points: It takes a little time, but it spreads quickly 3 points: Can be expanded in the same time as before 2 points: Very time consuming, but spreadable 1 point: Cannot be expanded.

[0042] (8) Handling of nonwoven fabric Using a sample of a 5 cm square nonwoven fabric soaked in 15 ml of water, the operability of the nonwoven fabric when it was slid after being applied to the skin surface was evaluated based on the following evaluation criteria. The results of the evaluations by the 10 monitors were averaged, and the average value was calculated as an index of the operability of the nonwoven fabric. An average score of less than 3 points was deemed to be unfavorable for the operability of the nonwoven fabric. <Evaluation criteria> 5 points: The nonwoven fabric catches on the operating hand and can be moved very easily. 4 points: The nonwoven fabric catches slightly on the operating hand, making it easy to move. 3 points: Average 2 points: The nonwoven fabric does not catch on the operating hand very much, so it is difficult to move it. 1 point: The nonwoven fabric slips from the operating hand and is difficult to move.

[0043] (9) Adhesion of nonwoven fabric Using a sample of a 10 cm square nonwoven fabric soaked in 25 ml of water, the adhesion of the nonwoven fabric to the front surface and the skin surface was judged based on the following evaluation criteria. The results of the judgments of the 10 monitors were averaged, and the average value was calculated as an index of adhesion. An average score of less than 3 points was deemed to indicate poor adhesion. <Evaluation criteria> 5 points: The nonwoven fabric and the skin surface are tightly attached with no gaps 4 points: There is a small gap between the nonwoven fabric and the skin surface, but it is firmly attached 3 points: Average 2 points: The nonwoven fabric and the skin surface are attached, but there are many gaps 1 point: The nonwoven fabric and the skin surface are not sticking together.

[0044] (10) Maneuverability during drying A 5 cm square nonwoven fabric was immersed in grade 3 water conforming to ISO3696 at 20°C ± 2°C for 1 hour, then removed from the water and left in a thermostatic chamber at 20°C and 65% RH for 30 minutes to simulate a state during drying. The maneuverability of this sample nonwoven fabric when it was affixed to the skin and slid across the skin was evaluated based on the following evaluation criteria. The evaluation results of 10 monitors were averaged, and the average value was calculated as an index of the maneuverability of the nonwoven fabric. A rating of less than 3 points was deemed to indicate that the nonwoven fabric had poor maneuverability. <Evaluation criteria> 5 points: The nonwoven fabric catches on the operating hand and can be moved very easily. 4 points: The nonwoven fabric catches slightly on the operating hand, making it easy to move. 3 points: Average 2 points: The nonwoven fabric does not catch on the operating hand very much, so it is difficult to move it. 1 point: The nonwoven fabric slips from the operating hand and is difficult to move.

[0045] <Evaluation for pad use> (1) Ease of removal when stacked Four samples were made by soaking 3 ml of water in nonwoven fabric punched into 4 cm diameter circles, and stacking the four samples with the front side facing up. The work of peeling off and removing one nonwoven fabric from the top of each of the four stacked samples was repeated three times, and the ease of removal when stacked was judged based on the following evaluation criteria. The most common evaluation from the results of the 10 monitors was used as an index of ease of removal. <Evaluation criteria> 〇: The pads do not stick together and can be easily removed. △: The pads stick together a little, but they can be removed. ×: The pads are stuck together and difficult to remove.

[0046] (2) Pad operability Using a sample of nonwoven fabric punched into a 4cm diameter circle soaked in 3ml of water, the front side of the nonwoven fabric was applied to the skin and then slid across the skin to evaluate its operability based on the following criteria. The most common evaluation given by the 10 monitors was used as an index of the operability of the pad. <Evaluation criteria> 〇: The pad catches on the operating hand and can be slid easily. △: The pad does not catch on the hand and is not prone to slipping. ×: The pad slips from the operating hand and is difficult to slide.

[0047] (3) Adhesion of the front surface of the pad A sample of nonwoven fabric was soaked in 3 ml of water and punched into a 4 cm diameter circle, and the nonwoven fabric was attached with the front side facing the skin, and the adhesion was judged based on the following evaluation criteria. The most common evaluation among the 10 monitors was used as an index of the adhesion of the front side of the pad. <Evaluation criteria> 〇: The pad and skin surface are tightly attached with no gaps △: The pad and skin surface are attached, but there are many gaps ×: The pad is not attached to the skin.

[0048] (4) Ability to scrape off dirt from the underside of the pad A sample of nonwoven fabric punched into a 4cm diameter circle soaked in 3ml of water was used, and the back side of the pad was attached to the skin, then the pad was slid over the skin. The ability to remove dirt such as dead skin cells and dirt from pores was evaluated based on the following criteria. The most common evaluation from the 10 monitors was used as an index of the ability to remove dirt from the back side of the pad. <Evaluation criteria> 〇: Dirt has been completely removed △: Some of the dirt has been scraped off ×: The dirt was not removed.

[0049] (5) Pad overall evaluation The results of the above pad evaluations (1) to (4) were combined and the overall pad evaluation was determined based on the following evaluation criteria. <Evaluation criteria> O: As a result of evaluation (1) to (4), 4 O △: 3 〇s as a result of evaluation of (1) to (4) ×: The results of the evaluations (1) to (4) were 2 or less ○

[0050] [Example 1] Cotton linters were dissolved in a cuprammonium solution to prepare a spinning dope (cotton linters 10 wt%, ammonia 7 wt%, copper 3 wt%). The spinning dope was continuously spun onto a net in five layers under tension to form a sheet, and the obtained sheet was regenerated with dilute sulfuric acid and washed with water. Then, a 3 MPa entanglement water flow was blown on the special herringbone weave net at an angle of 3° to the thickness direction of the nonwoven fabric, and the fibers were entangled while forming convex parts on the sheet to give a pattern. Finally, the sheet was dried with hot air at 100°C to obtain a cellulose fiber nonwoven fabric. The special herringbone weave net used was woven with seven meridians crossing the latitude lines, as shown in Figure 4, with 56 meridians / 25.4 mm and 25 latitude lines / 25.4 mm. The net speed was 47 m / min. The obtained cellulose fiber nonwoven fabric had a basis weight of 22.7 g / m 2 The nonwoven fabric had a thickness of 0.18 mm and a fiber diameter of 11.6 μm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0051] [Example 2] The weight of the nonwoven fabric is 30.1g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the discharge amount of the spinning dope was changed so as to obtain a thickness of 0.23 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0052] [Example 3] The weight of the nonwoven fabric is 37.7g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the amount of the spinning dope discharged was changed so that the nonwoven fabric had a thickness of 0.30 mm. The properties and evaluation results of the nonwoven fabric obtained are shown in Table 1 below.

[0053] [Example 4] The weight of the nonwoven fabric is 45.2g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the discharge amount of the spinning dope was changed so as to obtain a thickness of 0.33 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0054] [Example 5] The weight of the nonwoven fabric is 49.4g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the discharge amount of the spinning dope was changed so that the thickness of the obtained nonwoven fabric was 0.37 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below, and the evaluation results of the obtained nonwoven fabric for use as a pad are shown in Table 2 below.

[0055] [Example 6] The weight of the nonwoven fabric is 80.9g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the discharge amount of the spinning dope was changed so that the thickness of the obtained nonwoven fabric was 0.55 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below, and the evaluation results of the obtained nonwoven fabric for use as a pad are shown in Table 2 below.

[0056] [Example 7] The weight of the nonwoven fabric is 30.4g / m2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the amount of the spinning dope discharged was changed so that the fiber diameter was 5.87 μm, and the shape of the spinning dope discharge hole was changed so that the fiber diameter was 5.87 μm. The thickness of the obtained nonwoven fabric was 0.22 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0057] [Example 8] The weight of the nonwoven fabric is 37.8g / m 2 A nonwoven fabric was obtained in the same manner as in Example 7, except that the amount of the spinning dope discharged was changed so that the thickness of the nonwoven fabric obtained was 0.25 mm. The properties and evaluation results of the nonwoven fabric obtained are shown in Table 1 below.

[0058] [Example 9] Asahi Kasei Fibers' Bemberg (registered trademark) staple fiber (material name Cupra) 1.4dex x 38mm cotton was used to make a 21.9g / m2 spunlace fabric using spunlace manufacturing equipment. 2 A carded web of the above formula was produced. The obtained carded web was placed on a special herringbone weave net and an entanglement water flow of 3 MPa was struck at an angle of 3° to the thickness direction of the nonwoven fabric, and while entangling the fibers, convex portions were formed on the sheet to give a pattern. The sheet was then dried with hot air at 100°C to obtain a cellulose fiber nonwoven fabric. The special herringbone weave net used was the same as that used in Example 1. The net speed was 47 m / min. The thickness of the obtained nonwoven fabric was 0.18 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0059] [Example 10] The cotton linter was dissolved in N-methylmorpholine N-oxide to prepare a spinning solution, and the card web was then made into short fibers with a thickness of 40.1 g / m. 2 A nonwoven fabric was obtained in the same manner as in Example 9, except that the amount of fiber was changed so that the thickness of the nonwoven fabric obtained was 0.26 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below, and the evaluation results of the obtained nonwoven fabric for use as a pad are shown in Table 2 below.

[0060] [Example 11] The composition of the spinning solution was 85% by mass of staple fibers made from cotton linters dissolved in N-methylmorpholine N-oxide, and 25% by mass of staple fibers made from polyester. The card web was then mixed with 25.1 g / m 2 A nonwoven fabric was obtained in the same manner as in Example 9, except that the amount of fiber was changed so that the thickness of the nonwoven fabric obtained was 0.19 mm. The properties and evaluation results of the nonwoven fabric obtained are shown in Table 1 below.

[0061] [Example 12] A nonwoven fabric was obtained in the same manner as in Example 1, except that a spinning solution prepared by dissolving cotton linters in N-methylmorpholine N-oxide was used. The basis weight of the obtained nonwoven fabric was 35.0 g / m 2 The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0062] [Example 13] A nonwoven fabric was obtained in the same manner as in Example 2, except that the inclination of the entangling water flow was set to 1° with respect to the thickness direction of the nonwoven fabric. The basis weight of the obtained nonwoven fabric was 30.2 g / m 2 The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0063] [Example 14] The net speed was changed to 55m / min, and the weight of the nonwoven fabric was 28.9g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the discharge amount of the spinning dope was changed so that the thickness of the nonwoven fabric obtained was 0.19 mm. The properties and evaluation results of the nonwoven fabric obtained are shown in Table 1 below.

[0064] [Example 15] The net speed was changed to 40 m / min, and the weight of the nonwoven fabric was 90.0 g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the discharge amount of the spinning dope was changed so as to obtain a thickness of 0.58 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0065] [Example 16] The net speed was changed to 55 mm / min, the inclination of the interlacing water flow was set to 1° with respect to the thickness direction of the nonwoven fabric, and the weight of the nonwoven fabric was set to 34.8 g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the discharge amount of the spinning dope was changed so that the thickness of the nonwoven fabric obtained was 0.22 mm. The properties and evaluation results of the nonwoven fabric obtained are shown in Table 1 below.

[0066] [Example 17] The net speed was changed to 40 m / min, the inclination of the interlacing water flow was set to 5° with respect to the thickness direction of the nonwoven fabric, and the weight of the nonwoven fabric was increased to 140.2 g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the amount of the spinning dope discharged was changed so that the thickness of the nonwoven fabric obtained was 0.94 mm. The properties and evaluation results of the nonwoven fabric obtained are shown in Table 1 below.

[0067] [Example 18] A nonwoven fabric was obtained in the same manner as in Example 1, except that the amount of the spinning dope discharged was changed so that the nonwoven fabric had a basis weight of 63.3 g / m2. The thickness of the obtained nonwoven fabric was 0.47 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0068] [Example 19] The weight of the nonwoven fabric is 65.8g / m 2 A nonwoven fabric was obtained in the same manner as in Example 1, except that the discharge amount of the spinning dope was changed and the inclination of the entangling water flow was set to 5° with respect to the thickness direction of the nonwoven fabric so that the nonwoven fabric had a thickness of 0.48 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0069] [Example 20] A nonwoven fabric was obtained in the same manner as in Example 1, except that the net speed was changed to 32 m / min, the inclination of the entangling water flow was set to 5° with respect to the thickness direction of the nonwoven fabric, and the discharge amount of the spinning dope was changed so that the nonwoven fabric had a basis weight of 112.0 g / m2. The thickness of the obtained nonwoven fabric was 0.75 mm. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0070] [Comparative Example 1] A nonwoven fabric was obtained in the same manner as in Example 3, except that a plain weave net was used instead of the special herringbone weave net. The plain weave net had one warp line and one weft line woven alternately, with 40 warp lines / 25.4 mm and 30 weft lines / 25.4 mm. The basis weight of the obtained nonwoven fabric was 38.4 g / m 2 The nonwoven fabric had a thickness of 0.32 mm and a mesh pattern in which high fiber content regions ran perpendicular to the warp and weft directions. The pattern of the obtained nonwoven fabric is shown in Figure 6. Compared with Example 3, there were no problems with the operability and adhesion of the nonwoven fabric, but the mesh pattern caused problems with the separation of the nonwoven fabric. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below, and the evaluation results of the obtained nonwoven fabric for use as a pad are shown in Table 2 below.

[0071] [Comparative Example 2] A nonwoven fabric was obtained in the same manner as in Example 10, except that a plain weave net was used instead of the special herringbone weave net. The plain weave net used was the same as that in Comparative Example 1. The basis weight of the obtained nonwoven fabric was 39.2 g / m 2 The nonwoven fabric had a thickness of 0.29 mm and a mesh pattern in which the high fiber content areas ran perpendicular to the warp and weft directions. Compared with Example 10, there were no problems with the operability and adhesion of the nonwoven fabric, but the mesh pattern caused problems with the separation of the nonwoven fabric. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0072] [Comparative Example 3] A nonwoven fabric was obtained in the same manner as in Example 2, except that the entanglement water flow was applied perpendicular to the thickness direction of the nonwoven fabric. The basis weight of the obtained nonwoven fabric was 29.8 g / m 2 The thickness was 0.28 mm, and the difference in the coefficient of friction between the front and back was 8%. Compared to Example 2, there was no problem with the separation of the nonwoven fabric, but the small difference in the coefficient of friction between the front and back hindered the operability of the nonwoven fabric, and the large coefficients of friction on both sides hindered adhesion. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0073] [Comparative Example 4] A nonwoven fabric was obtained by a general manufacturing method with reference to Example 1 of Japanese Patent No. 3559533. The basis weight of the obtained nonwoven fabric was 41.4 g / m 2 The nonwoven fabric had a thickness of 0.30 mm and a difference in coefficient of friction between the front and back of the fabric of 4%. There were no problems with the separation of the nonwoven fabric, but the inclusion of fibers other than cellulose fibers reduced its liquid absorption and hindered its adhesion. The small difference in coefficient of friction between the front and back of the fabric hindered its operability. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below, and the evaluation results of the obtained nonwoven fabric for use as a pad are shown in Table 2 below.

[0074] [Comparative Example 5] A nonwoven fabric was obtained in the same manner as in Comparative Example 4, except that staple fibers prepared from a spinning solution in which cotton linters were dissolved in N-methylmorpholine N-oxide were used. The basis weight of the obtained nonwoven fabric was 38.9 g / m 2 The thickness was 0.29 mm, and the difference in the coefficient of friction between the front and back was 5%. There were no problems with the separation or adhesion of the nonwoven fabric, but the small difference in the coefficient of friction between the front and back hindered the handling of the nonwoven fabric. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0075] [Comparative Example 6] The fibers were changed to staple fibers made from natural cotton, and the card web was 62.5 g / m 2 A nonwoven fabric was obtained in the same manner as in Example 10, except that the fiber amount was changed so that the entanglement water flow was blown perpendicular to the thickness direction of the nonwoven fabric, and a plain weave net was used instead of the special herringbone weave net. The plain weave net used was the same as that in Comparative Example 1. The thickness of the obtained nonwoven fabric was 0.37 mm, the pattern was a mesh pattern in which the high fiber amount region ran perpendicular to the vertical and horizontal directions, and the difference in friction coefficient between the front and back was 3%. Compared to Example 10, there was no problem with adhesion, but the mesh pattern hindered the separation of the nonwoven fabric, and the small difference in friction coefficient between the front and back hindered operability. The properties and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0076] [Comparative Example 7] A nonwoven fabric was obtained by the same manufacturing method as in Example 21 of JP 2021-50434 A, except that the support was changed to a special herringbone twill net. The basis weight of the obtained nonwoven fabric was 37.6 g / m2, the thickness was 0.32 mm, and the difference in the friction coefficient between the front and back was 4%. There were no problems with the separation and adhesion of the nonwoven fabric, but the difference in the friction coefficient between the front and back was small, which caused problems with the operability of the nonwoven fabric. The characteristics and evaluation results of the obtained nonwoven fabric are shown in Table 1 below.

[0077] [Table 1]

[0078] [Table 2] [Industrial Applicability]

[0079] The nonwoven fabric containing the cellulose fibers of the present invention has excellent handleability in a wet state, in particular the ease of separation of the nonwoven fabric when unfolding it from a folded state, and the ease of operation of the nonwoven fabric when sliding it along a target surface, and also has high adhesion to the target surface. Therefore, the nonwoven fabric can be suitably used, for example, as a substrate for wet sheets such as face masks, toner pads, wet wipers, and dry wipers. [Explanation of symbols]

[0080] (A) High fiber content area (A-1) High fiber content region tilted at 3° to 87° to the vertical direction (A-2) High fiber content region tilted at -3° to -87° to the vertical direction (B) Low fiber content region (C) Intersection of high fiber content region (A-1) and high fiber content region (A-2)

Claims

1. A nonwoven fabric containing cellulose fibers, which has a herringbone pattern formed of a high fiber content region having a large amount of accumulated fibers and a low fiber content region having a relatively small amount of accumulated fibers compared to the high fiber content region, In a dry state, when the friction coefficients of the front and back surfaces of the nonwoven fabric are different, with the surface with a smaller friction coefficient being the front surface and the surface with a larger friction coefficient being the back surface, the following formula is satisfied: Difference in friction coefficient (%) = {(friction coefficient of back surface - friction coefficient of front surface) / friction coefficient of front surface} x 100 and the content of cellulose fiber in the nonwoven fabric is 80% by weight or more and 100% by weight or less.

2. 2. The nonwoven fabric of claim 1, wherein the cellulose fibers are continuous long fibers.

3. 3. The nonwoven fabric according to claim 1, wherein the coefficient of friction of the front surface of the nonwoven fabric in a dry state is 0.05 or more and 0.3 or less.

4. 3. The nonwoven fabric according to claim 1, wherein the surface roughness of the front surface of the nonwoven fabric in a dry state is 10 μm or more and 60 μm or less.

5. The nonwoven fabric has a basis weight of 10 g / m 2 150g / m or more 2 3. The nonwoven fabric according to claim 1 or 2, having a thickness of 0.1 mm or more and 1.0 mm or less.

6. 3. The nonwoven fabric according to claim 1, wherein the initial tensile strength of the nonwoven fabric in a longitudinal direction in a wet state is 0.1 N / 50 mm or more and 3.0 N / 50 mm or less.

7. 3. The nonwoven fabric according to claim 1, wherein the coefficient of friction of the back surface of the nonwoven fabric in a dry state is 0.05 or more and 0.35 or less.

8. 4. The nonwoven fabric according to claim 3, wherein the coefficient of friction of the back surface of the nonwoven fabric in a dry state is 0.05 or more and 0.35 or less.

9. 3. The nonwoven fabric according to claim 1, wherein the difference in friction coefficient is 30% or more and 50% or less.

10. 10. The nonwoven fabric according to claim 9, wherein the coefficient of friction of the front surface of the nonwoven fabric in a dry state is 0.13 or more and 0.17 or less, and the coefficient of friction of the back surface of the nonwoven fabric in a dry state is 0.17 or more and 0.35 or less.

11. 3. The nonwoven fabric according to claim 1, wherein the content of the cellulose fibers in the nonwoven fabric is 95% by weight or more and 100% by weight or less.

12. A face mask comprising the nonwoven fabric according to claim 1 or 2.

13. A cosmetic toner pad comprising the nonwoven fabric of claim 1 or 2.

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