TWI649471B - Hydrophilic fluffy nonwoven - Google Patents

Abstract

The invention provides a hydrophilic fluffy non-woven fabric, which has excellent water permeability, and is particularly suitable for surface raw materials of sanitary materials such as a top sheet of a diaper. The above-mentioned hydrophilic fluffy non-woven fabric of the present invention is characterized in that it is composed of thermoplastic fibers and has a surface structure of the non-woven fabric, that is, when the measurement reference length of the surface of the non-woven fabric is set to 100 μm, it is defined by the X direction and the Y direction. The ratio of the maximum height in the unit block to the height (thickness) of the non-woven fabric in the Z direction without load of 30% or more is equal to the surface area of the non-woven fabric of 20 mm × 20 mm per 40,000 blocks. 50% or more, and the 45 ° oblique flow length value of the non-woven fabric is 25 mm or less, and the fourth durable water permeability index is 85% or more.

Description

Hydrophilic fluffy nonwoven

The present invention relates to a hydrophilic fluffy nonwoven fabric that absorbs urine, body fluids, and the like without residue when used as a surface raw material, such as sanitary materials.

In recent years, the use of disposables has increased significantly, and the required quality or performance has been increasing. The non-woven fabric used as the top sheet of a diaper is required to pass body fluids, and further, the performance (water permeability) of passing the body fluids quickly to the absorbent body is required. A water-repellent polyolefin-based nonwoven fabric is commonly used as a raw material of a top sheet that requires water permeability, and water permeability is imparted by applying a surfactant as a water-permeable agent. Up to now, regarding the improvement of water permeability, for example, in the following Patent Document 1, a method of improving a water permeability agent has been adopted to improve the water permeability. For the improvement of water permeability, it is necessary to choose a surfactant with a higher activity capacity. Therefore, when it is used as the surface raw material of sanitary materials, it may easily cause skin rash or eczema on the surface of the contact, which will stimulate the skin. Sexually poor. On the other hand, in the following Patent Document 2, by performing a shaping process on the nonwoven fabric, the surface structure of the nonwoven fabric becomes a concave-convex structure, thereby reducing the area of contact with the skin, and improving the osmosis performance as an index of water permeability and Durable water permeability. However, in order to impart a concave-convex structure, processing such as special embossing is required. Therefore, the manufacturing cost is increased and the productivity is not high. In addition, because the thinned portion is generated by embossing between the rollers, the effect of improving the water permeability obtained is not obvious. Moreover, in the following patent document 3, uneven | corrugated processing is performed with respect to a nonwoven fabric, and introduction of a body fluid is improved. However, this method has concerns about imparting a moist touch to the skin. When a flat-shaped nonwoven fabric is used as a surface sheet of a diaper, a physiological article, or the like, the entire surface of the nonwoven fabric is brought into contact with an absorber, that is, a mixture of pulp and a polymer absorber, which is located below the surface sheet. When wearing a diaper or a physiological article, the weight of the user is applied to the surface sheet and the absorbent body, and the non-woven fabric as the surface sheet comes into closer contact with the absorbent body. Therefore, the body fluid attached to the surface of the non-woven fabric can move to the absorbent body quickly, but When a non-woven fabric having a concave-convex shape like Patent Document 3 and a cavity inside the convex portion is used as the surface sheet, the convex portion of the non-woven fabric and the absorbent body are not in contact with each other. Therefore, when the body fluid adheres to the surface of the nonwoven fabric, it is difficult to move the body fluid to the absorbent body quickly. Furthermore, the body fluid adhering to the convex portion is kept inside the non-woven fabric due to surface tension, and thus may give a moist touch to the skin. Furthermore, when a flat non-woven fabric is used during urination, the entire surface of the non-woven fabric is used to treat the urine. However, in the case of a non-woven fabric having a concave-convex shape, the urine is concentrated in the recessed portion that easily flows in. That is, the amount of urine flowing into the concave portion is larger than that of the convex portion, and the water-permeable agent adhering to the concave portion is washed away by the urine. If the water-permeable agent of the recessed part is washed away by urine, the urine stays in the recessed part, so that it may give a wet touch to the wearer. In addition, there is a concern that as time passes, urine remaining in the recesses evaporates, causing skin rash or eczema. [Prior Art Literature] [Patent Literature] [Patent Literature 1] Japanese Patent Laid-Open No. 10-53955 [Patent Literature 2] Japanese Patent Laid-Open No. 2004-113489 [Patent Literature 3] International Publication No. 2012-086730

[Problems to be Solved by the Invention] In view of the foregoing, a problem to be solved by the present invention is to provide a hydrophilic fluffy non-woven fabric having excellent water permeability and suitable for surface materials of sanitary materials such as top sheets of diapers. [Technical means to solve the problem] As described above, in order to exhibit excellent water permeability, the design of a surfactant provided as a water permeable agent and the surface structure of the nonwoven fabric become important. In particular, by setting the surface of the nonwoven to a rough structure with fine irregularities, when body fluids such as urine or sweat adhere to the surface of the nonwoven, the rougher the surface structure, the smaller the contact angle between the body fluid and the surface of the nonwoven, and the easier it is for the body fluid to be introduced Non-woven interior. The present inventors paid attention to the fine structure on the surface of the non-woven fabric, studied the crimp number of the long-fiber non-woven fabric, the joining method, and the method of imparting water permeability, and carried out experiments repeatedly. As a result, the fibers were arranged in an appropriate range through development. The non-woven fabric has successfully improved the 45-degree water-slope oblique flow length value and the durable water-permeability index, which have become the water-permeability index, thereby completing the invention. That is, the present invention is as follows. [1] A hydrophilic fluffy non-woven fabric, characterized in that it comprises thermoplastic fibers and has a surface structure of the non-woven fabric. When the measurement reference length on the surface of the non-woven fabric is set to 100 μm, the X-direction and Y-direction are used. The ratio of the maximum height in the defined unit block to the block with a height (thickness) of 30% or more in the Z direction of the non-woven without load is equal to the number of blocks per 40,000 equivalent to the surface area of the non-woven 20 mm × 20 mm The medium is 50% or more, and the non-woven fabric has a 45-degree water permeability oblique flow length value of 25 mm or less, and the fourth durable water permeability index is 85% or more. [2] The hydrophilic fluffy nonwoven fabric according to the above [1], wherein an orientation index in the thickness direction of the hydrophilic fluffy nonwoven fabric obtained by X-ray CT (Computed Tomography) is 0.43 or less. [3] The hydrophilic fluffy nonwoven fabric according to the above [1] or [2], wherein the compression bulk of the hydrophilic fluffy nonwoven fabric is 0.20 gf · cm / cm ² or more and 1.00 gf · cm / cm ² or less. [4] The hydrophilic fluffy nonwoven fabric according to any one of the above [1] to [3], wherein the number of curls of the fibers constituting the hydrophilic fluffy nonwoven fabric is 5 to 45 per 2.54 cm (inch). [5] The hydrophilic fluffy nonwoven fabric according to any one of the above [1] to [4], wherein the thermoplastic fiber is a side-by-side or eccentric sheath-core composite fiber. [6] The hydrophilic fluffy nonwoven fabric according to any one of the above [1] to [5], wherein the thermoplastic fiber is a polyolefin-based fiber. [7] The hydrophilic fluffy nonwoven fabric according to any one of the above [1] to [6], wherein the thermoplastic fiber is a long fiber. [8] A sanitary material using the hydrophilic fluffy nonwoven fabric according to any one of the above [1] to [7]. [Effects of the Invention] The hydrophilic fluffy nonwoven fabric of the present invention has excellent water permeability, and therefore can be preferably used as a top sheet on the surface of sanitary materials, such as menstrual tampons, incontinence pads, disposable diapers, etc. It can also be used for masks, furnaces, tape base cloths, patch base cloths, wound base cloths, packaging materials, wipes, medical gowns, bandages, clothing, skin care sheets, etc.

Hereinafter, embodiments of the present invention will be described in detail. The nonwoven fabric according to this embodiment includes thermoplastic fibers, and may be a long-fiber nonwoven fabric manufactured by a spunbond method, or a short-fiber nonwoven fabric manufactured by a carding method or the like. However, in the case of short-fiber non-woven fabrics, the fibers are pulled in the X direction or the Y direction during carding, and the surface tends to be smooth. From the viewpoint of the situation, strength, productivity, and reduction of skin irritation, etc. In other words, as the fiber constituting the fabric, a long fiber produced by a spunbond method is preferable. In this specification, the term "long fiber" refers to a fiber having a fiber length of 55 mm or more. The shorter the length of the fiber, the greater the probability that the end of the fiber will contact the skin. Therefore, it gives a sticky feel, so the fiber length is preferably 55 mm or more. Examples of the thermoplastic resin constituting the thermoplastic fiber include polyolefin resins such as polyethylene, polypropylene, and copolymerized polypropylene; polyethylene terephthalate, polybutylene terephthalate, and polynaphthalene dicarboxylic acid. Polyester-based resins such as ethylene glycol and copolymerized polyester; Polyamide-based resins such as nylon-6, nylon-66, and copolymerized nylon; and polylactic acid, polybutylene succinate, and polyethylene succinate The biodegradable resin such as an ester is not particularly limited. From the viewpoint of the texture of the non-woven fabric and the case where most of the applications used are disposable materials, from the viewpoint of convenience for general use and recycling, a polyolefin resin is preferred. As the form of the thermoplastic fiber, from the viewpoint of imparting characteristics to the surface structure of the non-woven fabric, it is preferable that the fiber is crimped. The number of crimps is preferably 5 / 2.54 cm (inch) or more, more preferably 5 / inch or more and 45 / inch or less, still more preferably 10 / inch or more and 40 / inch or less, particularly preferably Above 10 / inch and below 25 / inch. If it is a non-woven fabric made of fibers with a crimping number of more than 45 per inch, the shortening or unevenness caused by the crimping of the fibers will be more prominent, resulting in a deterioration in the appearance of the non-woven fabric, and in addition, the infiltration index due to the unevenness . Moreover, if it is a non-woven fabric made of fibers having a crimp number of less than 5 / inch, the required surface roughness cannot be obtained, and the thickness becomes thin, the texture is impaired, or it is difficult to obtain the required water permeability. As a method for imparting crimping to the fibers, crimping can be provided by setting the fiber cross-section to a special-shaped cross-sectional shape and cooling the fiber while spinning. In addition, a composite fiber containing two or more thermoplastic resins can also exhibit crimping. By setting the structure to a side-by-side type (S / S), a eccentric sheath-core type (eccentric S / C), etc., it can be further easily To show crimping. In the case of a partial core sheath core type (partial S / C), the core portion may also be exposed on the fiber surface, and the ratio of the core portion to the fiber surface is preferably 0 to 50% by area ratio, and more preferably 0. ~ 30%. If the ratio of the core to the fiber surface is higher than 50%, it will affect the bonding at the time of bonding as a non-woven fabric, and the strength of the fabric is likely to be lowered, and fluff is easily generated. In the case of eccentric sheath-core type (partial S / C), in order to obtain the required number of curls, the center of gravity of the cross-sectional area of the core is preferably offset from the center of gravity of the cross-sectional area of the composite fiber by 5 to 40. %. The offset of the core is calculated by the following formula. Core offset (%) = (shortest distance between the center of gravity of the cross-sectional area of the composite fiber and the center of gravity of the cross-sectional area of the core) / (diameter of the wire) x 100 The above-mentioned fiber is composed of a combination of two or more thermoplastic resins In this case, any combination of the above-mentioned thermoplastic resins may be used as long as the desired effect can be exhibited. From the viewpoint of bonding fibers to each other, a combination of thermoplastic resins having a melting point difference is preferred. The weight ratio of the resin having a higher melting point difference in the fiber is preferably 20 wt% or more and 80 wt% or less, more preferably 30 wt% or more and 80 wt% or less, and still more preferably 50 wt% or more and 70%. wt% or less. From the viewpoint of the texture of the obtained nonwoven fabric, it is preferred to use a combination of polyolefin resins and a combination of polyolefin resins and polyester resins. When a polyolefin-based resin is used in combination, a composite fiber composed of a resin such as polyethylene, polypropylene, or a copolymer of these monomers and other α-olefins may be used. The other α-olefins are those having 3 to 10 carbon atoms. Specific examples include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, and 1-octene. When a polyolefin-based resin and a polyester-based resin are combined, the polyester-based resin is preferably a single component of polyethylene terephthalate or a copolymer containing isophthalic acid or the like. In addition, polyethylene terephthalate may be modified by blending or the like, and additives may be added. Among them, as a combination of thermoplastic resins, it is preferable that the first component is polypropylene in terms of strong strength, which is not easy to break during use, and excellent processing suitability when producing sanitary materials, and good texture. When the second component is made of polyethylene, and when the composite fiber is an eccentric sheath-core type, it is preferable that the core portion is made the first component and the sheath portion is made the second component. In the case of forming fibers from the above two types of thermoplastic resins, the polypropylene of the first component may be a polymer synthesized by a usual Ziegler-Natta catalyst, or may be a monomer represented by a metallocene Polymer synthesized by point active catalyst. It may also be an ethylene random copolymer polypropylene. These may be used alone or in combination of two or more. In particular, in terms of texture, strength, and dimensional stability, those containing homopolypropylene as a main component are preferred. In terms of spinnability during fiber production and strength of the obtained fiber, the lower limit of MFR (melt mass flow rate) of polypropylene is preferably 20 g / 10 min or more. , More preferably more than 30 g / 10 min, further preferably more than 40 g / 10 min, and most preferably more than 53 g / 10 min. The upper limit of MFR is preferably 85 g / 10 min or less, more preferably 70 g / 10 min or less, and still more preferably 60 g / 10 min or less. MFR is based on JIS-K7210 "Test method for melt mass flow rate (MFR) and melt volume flow rate (MVR) of plastics-thermoplastics" table 1, test temperature 230 ° C, test load 2.16 kg. In the case of forming fibers from the above two types of thermoplastic resins, the polyethylene of the second component may be a polymer synthesized by a usual Ziegler-Natta catalyst, or may be a monomer represented by a metallocene Polymer synthesized by point active catalyst. The polyethylene is preferably high-density polyethylene and linear low-density polyethylene, and the density is preferably 0.92 to 0.97 g / cm ³ , More preferably 0.925 ～ 0.96 g / cm ³ . From the viewpoint of spinnability when manufacturing fibers, the lower limit of the MI (Melt Index) of polyethylene is preferably 10 g / 10 min or more, and more preferably more than 15 g / 10 min. The upper limit of MI is preferably 100 g / 10 min or less, more preferably 60 g / 10 min or less, and even more preferably 40 g / 10 min or less. MI is measured in accordance with Table 1 of JIS-K7210 "Test Methods for Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR) of Plastics-Thermoplastics" at a test temperature of 190 ° C and a test load of 2.16 kg. When a polyester resin is used, the lower limit of the solution viscosity ηsp / c is preferably 0.2 or more, and more preferably 0.6 or more. The upper limit of the solution viscosity ηsp / c is preferably 0.9 or less, and more preferably 0.8 or less. From the viewpoints of strength and productivity, the non-woven fabric constituting the embodiment is preferably a fabric form using long fibers formed by a spunbond method. In the case of a composite long fiber made by combining two or more thermoplastic resins, for example, different thermoplastic resins are melt-extruded from two or more different extruders, and a spinning machine having a plurality of spinning holes is used. The silk nozzle is sprayed in the form of a thread in a state where two or more thermoplastic resins are compounded. Then, while cooling the blown wire to 5 ° C ~ 20 ° C by blowing cold air, the traction was performed by a traction device. The yarns protruding from the traction device are stacked on a conveyor and transferred in the form of a fabric. The fabric in transit can also be laminated to make a multilayer laminated non-woven mesh. In the case of multi-layer laminated non-woven fabrics, each layer can be formed with different fiber diameters, and non-woven fabrics of special-shaped fibers such as shaped cross-section fibers, crimped fibers, and hollow fibers can also be laminated. The above-mentioned non-woven meshes can be used: a method of bonding with an adhesive, a method of bonding with a low melting point fiber or a composite fiber, and a method of performing fusion bonding by spreading a hot-melt adhesive during the formation of the fabric. A method such as entanglement of fibers by water flow is not particularly limited. From the viewpoint of high-speed productivity, joining can also be performed by partial thermocompression bonding. For example, the fabric can be joined by a heated embossing / flattening roller that can provide a joint point such as a needle point shape, an oval shape, a rhombus shape, a rectangular shape, or the like. From the viewpoint of maintaining strength and flexibility, maintaining the volume of the non-woven fabric, and preventing the uneven structure on the surface from collapsing between the rollers, the area ratio of the thermocompression bonding in some thermocompression bonding is preferably 5 to 40%. More preferably, it is 5 to 25%. Furthermore, from the viewpoint of easily maintaining the characteristics of the surface structure of the nonwoven fabric or the thickness of the nonwoven fabric, especially in the case of a composite long fiber composed of two or more thermoplastic resins, it can be melted and heated as long as it is heated to the intersection of the fibers. It can be used without particular limitation if it is performed at a temperature higher than the following temperature. As a method for heating, a hot air circulation type, a hot air penetration type, an infrared heater type, a method of spraying hot air on both sides of the non-woven fabric, and introduction to heating can be used. Various heating methods such as the method in gas. From the viewpoint of obtaining more fiber bonding points at the intersection points of the fibers and increasing the breaking strength of the non-woven fabric, heating with hot air is preferred, and hot-air penetration is particularly preferred. The hot-air temperature of the hot-air penetration type is preferably adjusted to a temperature suitable for the thermoplastic resin having a lower melting point among the thermoplastic resins to be combined and facilitating joining. For example, when the low melting point resin of two or more thermoplastic resins is polyethylene, the preferred hot air temperature is to melt the polyethylene and proceed to 120 to 155 ° C, preferably 135 to 155 ° C, and more preferably 140. ℃ ～ 150 ℃. If the adhering temperature is higher than 120 ° C, the adhering of the fibers to each other at the intersection of the fibers can be exhibited, and the strength as a non-woven fabric can be exhibited. In addition, if the subsequent temperature is 155 ° C or higher, the degree of melting of the fibers becomes very high, and the texture becomes hard. The wind speed of the hot wind is preferably 0.5 to 3.0 m / s, more preferably 0.7 to 2.5 m / s, and even more preferably 2.0 m / s or less. If the wind speed is slow, the hot air cannot penetrate the thickness direction of the nonwoven fabric, resulting in lower strength. Also, if the wind speed is fast, although the hot air passes through, the fibers also collapse at the same time and become a non-woven fabric with a small volume. As long as it does not adversely affect the surface structure of the non-woven fabric, it is also possible to perform thermal bonding on the non-woven fabric before the above-mentioned heating and joining by hot air. From the viewpoint of productivity, heat bonding is preferably a pair of rolls by a combination of a metal embossing roll and a metal flat roll. From the viewpoint of maintaining the shape of the nonwoven web or the strength of the nonwoven fabric finally obtained, the embossed area ratio is preferably 5 to 30%, more preferably 5 to 20%, and still more preferably 6 to 15%. In addition, the deeper the embossing depth, the more the thickness of the nonwoven fabric can be maintained, preferably 0.5 to 2.0 mm, and more preferably 0.7 to 1.5 mm. The embossed shape is not particularly limited, and is preferably a circular shape, an oval shape, a rhombic shape, or a rectangular shape. The average fiber diameter of the non-woven fabric is preferably 8.0 μm or more and 38.0 μm or less, more preferably 9.0 μm or more and 33.5 μm or less, and further preferably 11.0 μm or more and 26.5 μm or less. From the viewpoint of spinning stability, the average fiber diameter is preferably 8.0 μm or more, and from the viewpoint of the texture of the non-woven fabric used for sanitary materials, it is more preferably 38.0 μm or less. The unit weight of non-woven fabric is preferably 8 g / m ² Above 80 g / m ² Below, more preferably 10 g / m ² Above 40 g / m ² Below, more preferably 10 g / m ² Above 30 g / m ² the following. If the weight per unit area is 8 g / m ² Above, it meets the strength as a non-woven fabric for sanitary materials, if it is 80 g / m ² In the following, the texture of the non-woven fabric used for sanitary materials is satisfied, and there is no heavy impression on the appearance. The height of the nonwoven fabric under no load is preferably 140 μm or more, more preferably 140 μm or more and 3000 μm or less, and still more preferably 140 μm or more and 2000 μm or less. From the standpoint of the texture of the non-woven fabric and the permeability of water permeability, the height at no load is preferably 140 μm or more. If it exceeds 3000 μm, it will have a heavy impression on the appearance, and it is rigid and unsuitable for use. Sanitary materials. The orientation index of the non-woven fabric obtained by X-ray CT is 0.43 or less, preferably 0.425 or less. If the alignment index obtained by X-ray CT is in this range, more fibers occupy the thickness direction of the nonwoven fabric, and the volume does not collapse even under a load, and becomes a fluffy nonwoven fabric, which can obtain excellent cushioning properties and an infiltration index. Lower hydrophilic fluffy non-woven fabric. The lower the lower limit, the better, but the alignment index is preferably 0.30 or more, and more preferably 0.33 or more. The compression work amount WC of the non-woven fabric in this embodiment is preferably 0.20 gf · cm / cm ² Above 1.00 gf · cm / cm ² Below, more preferably 0.20 gf · cm / cm ² Above 0.80 gf · cm · cm ² Hereinafter, when the compression work amount WC within this range is maintained, the cushioning property of non-woven fabrics used as sanitary materials and an excellent re-seepage index can be obtained. The hydrophilic fluffy nonwoven fabric of this embodiment contains or is coated with a water-permeable agent. As the water-permeable agent used, in consideration of safety to the human body, safety in steps, etc., examples include higher alcohols, higher fatty acids, alkylphenols, and the like, nonionic active agents to which ethylene oxide is added, and alkyl groups. Anionic surfactants such as phosphates and alkyl sulfates, etc., or surfactants composed of a mixture or the like. As the water-permeable agent, for example, a polyether compound, a polyvinyl ether-modified polysiloxane, a polyether-modified polysiloxane, a polyester compound, a polyamidine compound, a polyglycerin compound, or the like can be preferably used. As the method of containing or coating the water-permeable agent, existing methods such as kneading or coating methods (gravure coater, contact coater) and spraying method into the fiber can be used. Corona discharge treatment, Pre-treatment such as discharge treatment of normal piezoelectric paste. As a drying method after coating, a known method using convective heat transfer, conductive heat transfer, radiant heat transfer, or the like can be adopted, and drying using hot air or infrared rays, and drying using thermal contact can be used. The adhesion amount of the permeant varies depending on the intended use. For example, as a sanitary material, it is usually preferably in the range of 0.10 wt% to 1.50 wt%, more preferably 0.15 wt% to 1.20 wt% relative to the non-woven fabric. . If it is less than 0.10 wt%, it is difficult to obtain satisfactory water permeability. On the other hand, if it exceeds 1.50 wt%, skin rash or eczema tends to occur on the skin. The water-permeable agent may be diluted with a solvent such as water and applied as an aqueous solution. In addition, in order not to cause insufficient drying in the drying step accompanying the increase in the speed of the equipment, the application amount of the water-permeable agent aqueous solution is preferably small. The coating amount (wt%) on the non-woven fabric is preferably 1.0 wt% or more and 65 wt% or less, more preferably 3.0 wt% or more and 60 wt% or less, and further preferably 5.0 in any of the above coating methods. Above wt% and below 50 wt%. If it is less than 1.0 wt%, uniform coating cannot be obtained. On the other hand, if it exceeds 65 wt%, the required drying capacity becomes large, the equipment cost increases, and insufficient drying may occur. For example, in the application of a water-permeable agent by a gravure coater, the pattern of the gravure roll may be a lattice type or a pyramid type, and it is preferably an oblique line type where the water-permeable agent does not easily remain on the bottom of the gravure unit. Unit volume is preferably 5 cm ³ / m ² Above 40 cm ³ / m ² Below, up to 5 cm ³ / m ² , The coating amount is too small, so it is difficult to perform uniform coating, if it exceeds 40 cm ³ / m ² If the coating amount is too large, problems such as uneven adhesion of the water-permeable agent due to insufficient drying in the drying step or migration may occur. The depth of the gravure unit is preferably 10 μm or more and 80 μm or less, and the interval is preferably in the range of 80 meshes or more and 250 meshes or less, and it is preferably designed in such a manner as to become the unit volume. It can respond to the high speed of the equipment and can be coated efficiently. Even if it is a non-woven fabric with a thickness, it can be evenly applied in the thickness direction. Even if the permeability of the water-permeable agent and the non-woven fabric is slightly poor, it can be uniformly performed. It is preferable to apply a water-permeable agent by a spray method from the point of application | coating, and since there is no step which passes a nonwoven fabric between a pair of rolls, and it is easy to maintain the thickness of a nonwoven fabric. The spraying method may be a generally known spraying method using air compression, or a method of directly compressing a water-permeable agent aqueous solution and spraying it. From the viewpoint of being uniformly applied to a non-woven fabric, rotor dampening is particularly preferred. )the way. By implementing the strategy of preventing the water-permeable agent aqueous solution from splashing during coating, coating can be performed even when the equipment is running at high speed. The so-called rotor wetting method is a method of supplying a water-permeable agent aqueous solution to a rotating rotor, and spraying the water-permeable agent aqueous solution by using the centrifugal force of the rotor rotation. In the rotor wetting method, it is possible to spray liquid particles of a water-permeable agent aqueous solution flying out due to the rotation of the rotor only on the non-woven side to be coated in the coating direction, and can be applied to the non-woven CD (Cross Direction, transverse direction). The openings are defined in such a manner that the coating is performed in a uniform direction, and the spray particle size is adjusted by the rotation speed of the rotor. In the case of the above-mentioned rotor wetting method, for example, if the diameter of the rotor is 40 mm or more and 100 mm or less, the non-woven surface to be coated is set so that the water-permeable agent aqueous solution can uniformly adhere to the CD direction of the non-woven cloth to be coated. Distance from the center of the rotor. It is preferable to set it in such a way that one-half of the coating distribution range sprayed from the adjacent rotor overlaps. The rotor is preferably arranged at equal intervals in the CD direction within a range of 60 mm or more and 220 mm or less, and has two stages. The key to uniform coating is to make the spray particles penetrate deep into the non-woven fabric to be coated. The spray particle diameter is preferably 0.010 mm to 0.200 mm, and more preferably 0.030 mm to 0.070 mm. In order to form the optimal spray particle diameter, the surface tension of the water-permeable agent aqueous solution becomes important, and the spray particle diameter is calculated by the following formula. Spray particle size (μm) = {100000 × √ (surface tension (N / m))} / (rotor diameter (mm) × rotor speed (rpm)) In addition, the temperature of the water-permeable agent aqueous solution in these coating methods is lower than It is preferably 5 ° C or higher and 50 ° C or lower, and from the viewpoint of uniform dispersion and stability of the solution, more preferably 12 ° C or higher and 40 ° C or lower. The viscosity of the water-permeable agent aqueous solution is preferably 0.5 mPa · s or more and 50 mPa · s or less, and from the viewpoint of easy and uniform application, it is more preferably 0.8 mPa · s or more and 20 mPa · s or less. If the viscosity exceeds 50 mPa · s, the permeability of the water-permeable agent aqueous solution to the nonwoven fabric is poor, and it is difficult to perform uniform coating. The drying method after the application of the water-permeable agent solution can use a common drying method, and is not particularly limited. Known methods such as convection heat transfer, conduction heat transfer, and radiation heat transfer can be used. Hot air circulation type, hot air penetration type, Various drying methods such as an infrared heater type, a method of spraying hot air on both sides of the non-woven fabric, and a method of introducing hot air into the heating gas. As shown in FIG. 1, the surface structure of the non-woven fabric of this embodiment is characterized in that when the measurement reference length on the surface of the non-woven fabric is set to 100 μm, the maximum height in a unit block defined by the X direction and the Y direction is relative to The ratio of blocks having a height (thickness) of 30% or more when the non-woven fabric is under no load is 50% or more of the number of 40,000 blocks corresponding to the surface area of the non-woven fabric of 20 mm × 20 mm. The measurement reference length and the maximum height on the surface of the nonwoven fabric are as follows. A digital microscope KH-8700 (manufactured by Hirox) was used to measure the height information of the non-woven surface at 20 μm intervals in each direction in 20 mm MD (Machine Direction) direction and 20 mm CD direction of the non-woven fabric. The height information obtained in the 20 mm MD direction of the non-woven fabric and 20 mm CD direction is divided every 100 μm, and the length divided at this time is used as the measurement reference length. The difference between the maximum value and the minimum value in the unit block is the maximum height of the non-woven surface. The ratio of the maximum height to the height (thickness) of the non-woven fabric under no load is calculated from the maximum height (μm) / height (μm) under no load × 100. That is, the higher the ratio of the maximum height to the height (thickness) of the non-woven fabric when the weight is 30% or more, the larger the unevenness in the fine blocks on the surface of the non-woven fabric becomes. In this embodiment, the ratio of the maximum height to the height (thickness) of the non-woven fabric when no load is 30% or more is measured at a reference length of 100 μm with respect to the MD 20 mm × CD direction 20 mm of the non-woven fabric. For each 40,000 blocks obtained by the division, it is more than 50%. By having such a structure of the surface of the non-woven fabric, for example, regardless of the water-permeable agent imparted to the non-woven fabric, when a liquid such as urine adheres to the surface of the non-woven fabric, its contact angle becomes low, so that the liquid moves rapidly from the surface of the non-woven fabric to the inside of the non-woven fabric . From the viewpoint of the liquid mobility of the non-woven fabric, in this embodiment, the ratio of the block having a maximum height to a height (thickness) of 30% or more when the non-woven fabric is unloaded is 50% or more, preferably 52% or more , More preferably 55% or more, and still more preferably 60% or more. When the ratio is within the range, good water permeability can be exhibited. The higher the ratio, the better, but it is preferably 98% or less in terms of deteriorating the feel of the skin. The 45-degree water-slope oblique flow length, which is an indicator of the water permeability of the nonwoven fabric of this embodiment, is 25 mm or less, preferably 22 mm or less, more preferably 20 mm or less, and most preferably 18 mm or less. If the value of the 45-degree permeable oblique flow length exceeds 25 mm, for example, in the case of a surface material such as a disposable diaper, the liquid flow on the surface increases, which may easily cause urine leakage. The fourth durable water permeability index which is an indicator of the water permeability of the nonwoven fabric of this embodiment is 85% or more. If the value of the fourth-time durable water permeability index is less than 85%, for example, in the case of a surface material such as a disposable diaper, the surface material cannot pass water and lose its function as a surface material for multiple urinations, which may easily cause Leaking urine. In addition, the re-permeability index, which is an index of the water permeability of the nonwoven fabric of this embodiment, is preferably 0.8 g or less, and more preferably 0.5 g or less. If the value of the permeation index exceeds 0.8 g, for example, in the case of a surface material for a disposable diaper, when the surface material contacts the skin, it has a very moist touch and the use feeling becomes worse. The lower the permeation index, the better, but the value below 0.01 g is the lower limit of measurement, and the measurement deviation is larger. [Examples] Hereinafter, the present invention will be specifically described using examples and comparative examples, but the present invention is not limited to the following examples. In addition, the evaluation method of each characteristic is as follows, and the obtained physical property is shown in Table 1 below. Hereinafter, the direction of travel in nonwoven fabric production is referred to as the MD direction, and the direction perpendicular to the direction and the width direction are referred to as the CD direction. 1. The average fiber diameter (μm) is divided into 5 equal directions in the CD direction of the non-woven fabric, and a 1 cm square test piece is selected, and the fiber diameter is measured at 20 points using a microscope VHX-700F manufactured by KEYENCE Corporation, and the average value is calculated. 2.Weight per unit area of non-woven fabric (g / m ² ) According to JIS-L1906, select 5 pieces of MD 20 cm × CD 5 cm in the CD direction of the non-woven fabric in the same direction by selecting the position and measure the mass. The average value is converted into the weight per unit area to obtain it. Weight per unit area (g / m ² ). 3. Height (thickness) (μm) of the non-woven fabric without load. Randomly select 10 test pieces in MD direction 4 mm × CD direction 10 mm, and use SEM (Scanning Electron Microscope, Scanning Electron Microscope) (VE-8800) ) Take a photo of the cross section of the non-woven fabric. The obtained image was measured using the same image analysis software manufactured by KEYENCE. The distance in the thickness direction was measured at 5 points per image, and the average value was used as the height (thickness) (μm) when no load was applied. 4. The maximum height (μm) of the non-woven surface is cut in any direction with a size of 20 mm × 20 mm square to select the non-woven fabric. Next, using the 3D distribution function of a digital microscope KH-8700 (manufactured by Hirox), the height information of the surface of the selected nonwoven fabric was measured at 20 μm intervals in each direction in 20 mm in each side direction of the square of the nonwoven fabric. The height information obtained in each side of the non-woven square 20 mm × 20 mm is divided by 100 μm, and the divided length at this time is used as the measurement reference length. The difference between the maximum value and the minimum value in the block is taken as the maximum height of the non-woven surface. This measurement sequence is schematically shown in FIG. 1. The ratio of the maximum height of the non-woven fabric to the height (thickness) (μm) of the non-woven fabric under no load was calculated from the maximum height (μm) / height (thickness) (μm) without load × 100. Furthermore, divide the number of blocks whose ratio of the maximum height to the height (thickness) of the non-woven fabric is 30% or more by dividing the non-woven square by 20 mm × 20 mm in each side of the square to determine the reference length of 100 μm. 40,000 blocks to calculate the ratio (%). 5. Alignment index (X-ray CT) A test piece of 5 mm in the MD direction and 5 mm in the CD direction is arbitrarily cut and measured with a field of view of about 3 mm × 3 mm during image analysis. The measurement device is a high-resolution 3DX ray microscope nano3DX (manufactured by Rigaku Co., Ltd.), and is measured by CT measurement of low-energy high-brightness X-rays that obtains contrast even for light elements. The detailed conditions are shown below. X-ray target: Cu X-ray tube voltage: 40 kV X-ray tube current: 30 mA Lens: 1.08 μm / pix Combination: 2 Rotation angle: 180 ° Number of projections: 1000 exposure time: 10 seconds / camera Pixels: 3300 × 2500 Restructuring: The Feldkamp method performs image analysis on the three-dimensional tomogram obtained by CT measurement, and obtains the orientation indexes Ix, Iy, and Iz of three orthogonal axes (x, y, z). The thickness direction of the sample to be evaluated is consistent with the z direction. The so-called alignment indexes Ix, Iy, and Iz refer to the sum of the area of the fiber surface (the sum of the extended projection areas of the fiber surface in all directions) as viewed from the directions of x, y, and z, respectively. , Ay, Az are defined by Ix = Ax / (Ax + Ay + Az) Iy = Ay / (Ax + Ay + Az) Iz = Az / (Ax + Ay + Az). Ax, Ay, Az are obtained from a chromatogram. In this index, alignment is performed in a direction with a smaller value. In addition, all of them are 1/3 in the isotropic structure. 6. Compression work (WC) Select a 5 cm square test piece at 5 points in the CD direction, and use a compression test device (KES-G5) manufactured by Kato Tech. Set the test piece on a metal sample stand with a pressure area of 2 cm ² The circular plane of the steel plate is compressed. The compression speed is 0.067 mm / s, and the maximum compression load is set to 3.4 kPa (35 gf / cm ² ). The recovery process is also measured at the same speed, and the average value of compression work is calculated. 7. Number of crimps (unit / 2.54 cm (inch)) 5 points in the CD direction of the non-woven fabric and a 5 cm square test piece is selected. The microscope VH-Z450 manufactured by KEYENCE Corporation is in a state where no load is applied to the fiber. Next, select 5 fibers and measure the number of crimps per 1 inch of length, and calculate the number of crimps (number / inch) based on the average value. 8. Water flow at 45 ° oblique flow length (mm) 10 sheets of toilet paper (HARD SINGLE 1R55m manufactured by Itoman Co., Ltd.) are superimposed on a 45 ° oblique plate as an absorber, and a test cloth (20 cm square) ), 0.1 cc of physiological saline was added dropwise from a height of 10 mm above the cloth. Read the distance that the normal saline has flowed from the drip position to the end of the absorption. This measurement was performed at arbitrary 20 points in a test cloth, and the average value was made into the 45-degree water-permeable inclined flow length value (mm). 9. Durable water permeability index (%) 10 sheets of toilet paper (HARD SINGLE 1R55m manufactured by Itoman Co., Ltd.) are stacked as an absorber, and a test cloth (20 cm × 30 cm) is placed on the absorbent body. Further, a stainless steel plate with holes of 1.5 cm in diameter was placed at equal intervals at 10 places, and 0.3 cc of physiological saline was dropped from a height of 10 mm above the cloth on each hole. After 3 minutes, the same was repeated. Dropwise. After the third dropwise addition, the number of pores (A) absorbed within 10 seconds was counted. This test was performed on 40 identical samples, and {((A) / (10 holes × 40 samples) × 100)} was used as the third water-permeability endurance index (%). Further, after the fourth dropwise addition, the number of pores (B) absorbed within 10 seconds was counted in the same manner as the third time, and {((B) / (10 pores × 40 samples) × 100)} is the 4th pervious endurance index (%). 10. Infiltration index (g) In order to make the characteristics of the absorbent body constant as an absorbent body, a test cloth was placed on three specific filter papers (GRADE: 989 manufactured by Ahlstrоm). A plate (approximately 800 g) with a hole of 25 mm in diameter at the center was placed 10 cm square above it, and physiological saline (a liquid amount of 3.5 times the weight of the absorbent body) was added dropwise from a height of 25 mm above the center hole to make Its absorbed. Secondly, remove the plate above the test cloth, gently place a weight of 3.5 kg (10 cm square) and take 3 minutes to make the liquid distribution in the absorbent constant. Next, temporarily remove the 3.5 kg weight, and quickly place two pieces of pre-weighed filter paper for measurement (ERTMWWS SHEETS, 12.5 cm square manufactured by HOLLINGSWORTH & VOSE.CONPANY) on top of the test cloth, and gently place 3.6 kg again. Weight. After 2 minutes, the weight of the measurement filter paper was measured to increase. The value (g) of this increase was used as the re-seepage index. 11. Application amount (wt%) of the water-permeable agent aqueous solution The consumption amount of the water-permeable agent aqueous solution processed for one hour based on water-permeability-imparting processing is the value calculated by the following formula as the application amount (wt%) of the water-permeable agent aqueous solution. Coating amount (wt%) = Consumption of water-permeable agent solution (g) / {weight of non-woven fabric area (g / m ² ) × Width (m) × Processing Speed (m / min) × 60 (min)} × 100 12. Pure Adhesion of Permeable Agent (wt%) For 24 hours humidity control at 25 ℃ × 40% RH temperature and humidity The weight (W1) of the non-woven fabric sample to which the water-permeable agent is attached and the weight (W2) of the water-permeable agent obtained by Soxhlet extraction from the non-woven fabric sample using methanol are measured. (wt%). C (wt%) = [W2 / W1] × 100 Non-woven samples are sampled from 5 places at 30 cm intervals in the MD direction and 5 cm from 5 places at equal intervals within the width of the non-woven fabric in the CD direction. A 10 cm range and a non-woven sample was cut to a length of about 2 g, and a total of 10 test cloths were selected. The above measurement was performed, and the average value of these was used as the pure adhesion amount (wt%) of the water-permeable agent. 13. Dispersion Select a non-woven fabric at 50 cm × 50 cm, and classify according to the following evaluation criteria of the appearance of the non-woven fabric by visual judgment. The viewpoint of dispersion evaluation is to set whether or not streaks such as streaks are irregular, or whether single yarns are spread uniformly (whether they do not become lumpy). The higher the level, the better the dispersion. 5: Very good 4: Good 3: Normal (can be used as a product) 2: Poor 1: Very poor [Example 1] The MFR was 55 g / 10 min (according to JIS-K7210, at 230 ° C, High-density polyethylene with a polypropylene (PP) resin as the first component and a MI of 26 g / 10 min (measured under JIS-K7210 at a temperature of 190 ° C and a load of 2.16 kg) as the first component (HDPE) resin is used as the second component. The amount of the first component is 0.4 g / min · hоle, and the amount of the second component is 0.4 g / min · hоle by a spunbond method at a spinning temperature of 220 ° C. And the total ejection amount is 0.8 g / min · hоle, and the ratio of the first component to the second component becomes 1/1. The fiber is extruded toward the moving capture surface at a spinning speed of 3200 m / min using a high-speed airflow traction device using air spray. This filament group was used to prepare an eccentric sheath-core composite long-fiber fabric having an average fiber diameter of 17.9 μm. Then, for the obtained fabric, the fibers were adhered to each other by a hot air having a hot air temperature of 142 ° C and a hot air speed of 0.7 m / s to obtain a weight per unit area of 18 g / m. ² Composite long-fiber non-woven fabric with a crimp number of 15 per inch. Next, a 3 wt% aqueous solution of a water-permeable agent containing a mixture of hexaglycerol monostearate, polyether-modified polysiloxane and polyoxyalkylene castor oil ether was adjusted to a liquid temperature of 20 ° C and a liquid viscosity of 3.2 mPa · As the water-permeable agent aqueous solution used for the obtained nonwoven fabric, the coating amount was applied to the nonwoven fabric by a rotor wet method so that the coating amount became 10 wt%. The diameter of the rotor used is 80 mm, and each rotor is arranged at 115 mm intervals in the CD direction so that the distance between the center of the rotor and the coated non-woven fabric is 180 mm. In addition, the rotation speed of the rotor was adjusted so that the spray particle diameter of the sprayed water-permeable agent aqueous solution was 35 μm. When the measured reference length of the obtained non-woven surface is set to 100 μm, the ratio of the maximum height in the block to the non-woven height (thickness) of 30% or more is 85%, and the non-woven is permeable to water The 45-degree oblique flow length was 16 mm, the fourth durable water permeability index was 99%, and the re-seepage index was 0.12 g. The results are shown in Table 1 below. [Example 2] By the same method as in Example 1, an average fiber diameter of 17.9 μm and a basis weight of 10 g / m were obtained. ² 15 、 Eccentric sheath-core composite long-fiber non-woven fabric with a crimp number of 15 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. The ratio of the maximum height in the block when the measured reference length of the obtained non-woven surface is 100 μm to the non-woven height (thickness) of 30% or more is 87%, and the non-woven is permeable to water The 45-degree oblique flow length was 14 mm, the fourth durable water permeability index was 99%, and the re-seepage index was 0.50 g. The results are shown in Table 1 below. [Example 3] The discharge amount of the first component was 0.54 g / min · hоle, the discharge amount of the second component was 0.26 g / min · hоle, and the total discharge amount was 0.80 g / min · hоle. The first component and the second Except that the ratio of the components was set to about 2/1, a eccentric sheath-core composite long-fiber fabric having an average fiber diameter of 17.9 μm was prepared in the same manner as in Example 1. For the obtained eccentric sheath-core composite long-fiber fabric, the fibers were bonded to each other by a hot air having a hot air temperature of 145 ° C and a hot air speed of 1.0 m / s to obtain a weight per unit area of 18 g / m. ² Composite long fiber non-woven fabric with a crimp number of 10 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. The ratio of the maximum height in the block when the measured reference length of the obtained non-woven surface is 100 μm to the non-woven height (thickness) of 30% or more is 74%, and the non-woven is permeable to water The 45-degree oblique flow length was 16 mm, the fourth durable water permeability index was 99%, and the re-seepage index was 0.12 g. The results are shown in Table 1 below. [Example 4] An average fiber diameter of 17.9 μm and a basis weight of 18 g / m were obtained in the same manner as in Example 3. ² Composite long fiber non-woven fabric with a crimp number of 10 per inch. A 1 wt% aqueous solution of the water-permeable agent was adjusted to a liquid temperature of 20 ° C and a liquid concentration of 2.3 mPa · s, and a diagonal pattern of 120 meshes and a cell volume of 22 cm were used for gravure coating. ³ / m ² The gravure roll was coated on the obtained composite long-fiber nonwoven fabric so that the coating amount became 30% by weight, and then dried and wound by a drum dryer at 120 ° C. The ratio of the maximum height in the block when the measured reference length of the obtained non-woven surface is 100 μm to the height (thickness) of the non-woven when the load is 30% or more is 70%, and the non-woven is permeable to water The 45-degree oblique flow length value was 17 mm, the fourth durable water permeability index was 97%, and the infiltration index was 0.22 g. The results are shown in Table 1 below. [Example 5] The first component was made of the same polypropylene resin as in Example 1, and the second component was set to MI of 16.8 g / 10 min (based on JIS-K7210 at a temperature of 190 ° C and a load of 2.16 kg (Measurement) of the linear low-density polyethylene (LLDPE) resin, the amount of the first component is 0.54 g / min · hоle, and the amount of the second component is extruded by a spunbond method at a spinning temperature of 220 ° C. 0.26 g / min · hоle, with a total ejection volume of 0.8 g / min · hоle, and the ratio of the first component to the second component is about 2/1, which is extruded toward the moving capture surface using a high-speed airflow traction device using air spray. From this filament group, an eccentric sheath-core type long fiber fabric with an average fiber diameter of 20.5 μm was prepared. For the obtained eccentric sheath-core type long-fiber fabric, the fibers were bonded to each other by hot air at a hot air temperature of 150 ° C. and a hot air speed of 0.3 m / s to obtain a weight per unit area of 18 g / m. ² , Composite long fiber non-woven fabric with a crimp number of 40 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. The ratio of the maximum height in the block when the reference length of the obtained surface of the nonwoven fabric is 100 μm to the height (thickness) of the nonwoven fabric when the load is 30% or more is 92%. The water permeability of the nonwoven fabric is 92%. The 45-degree oblique flow length was 15 mm, the fourth durable water permeability index was 99%, and the re-seepage index was 0.35 g. The results are shown in Table 1 below. [Example 6] An average fiber diameter of 20.5 μm and a weight per unit area of 18 g / m were obtained by the same method as in Example 5. ² 2. Uneven core sheath-core composite long fiber non-woven fabric with a curling number of 40 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1, except that the concentration of the water-permeable agent aqueous solution was 5 wt%. The ratio of the maximum height in the block when the reference length of the obtained surface of the nonwoven fabric is 100 μm to the height (thickness) of the nonwoven fabric when the load is 30% or more is 92%. The water permeability of the nonwoven fabric is 92%. The 45-degree oblique flow length was 13 mm, the fourth durable water permeability index was 99%, and the re-seepage index was 0.47 g. The results are shown in Table 1 below. [Example 7] An eccentric sheath-core composite long-fiber fabric having an average fiber diameter of 17.9 μm was prepared by the same method as in Example 1. Then, the obtained eccentric sheath-core composite long-fiber nonwoven web was passed through a flat roll and an embossing roll (pattern specification: diameter 1.00 mm, staggered arrangement, lateral pitch 4.4 mm, longitudinal pitch 4.4 mm) at 100 ° C. , 7.9%), the fibers were temporarily bonded to each other, and then the fibers were bonded to each other by a hot air having a hot air temperature of 142 ° C and a hot air speed of 0.7 m / s to obtain a weight per unit area of 18 g / m ² Composite long fiber non-woven fabric with a crimp number of 17 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. The ratio of the maximum height in the block when the measured reference length of the obtained non-woven surface is 100 μm to the block (30% or more in height (thickness) when the non-woven is non-loaded) is 72%, and the non-woven is permeable to water The 45-degree oblique flow length was 18 mm, the fourth durable water permeability index was 95%, and the re-seepage index was 0.18 g. The results are shown in Table 1 below. [Example 8] An average fiber diameter of 17.9 μm and a weight per unit area of 8 g / m were obtained in the same manner as in Example 7. ² The eccentric sheath-core composite long-fiber non-woven fabric with a crimp number of 17 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. The ratio of the maximum height in the block when the measured reference length of the obtained non-woven surface is 100 μm to the non-woven height (thickness) of 30% or more is 74%, and the non-woven is permeable to water The 45-degree oblique flow length was 16 mm, the fourth durable water permeability index was 97%, and the re-seepage index was 0.42 g. The results are shown in Table 1 below. [Example 9] Using the same components as in Example 1, the amount of the first component extruded was 0.40 g / min · hоle and the amount of the second component was 0.40 by a spunbond method at a spinning temperature of 220 ° C. g / min · hоle, and the total ejection amount was 0.8 g / min · hоle, and the ratio of the first component to the second component was 1/1. The filament group was extruded toward a moving capture surface at a spinning speed of 3200 m / min using a high-speed air current traction device using air jets to prepare a side-by-side composite long fiber fabric with an average fiber diameter of 17.9 μm. Then, in the obtained parallel-type composite long-fiber fabric, fibers were bonded to each other in the same manner as in Example 7 to obtain a basis weight of 18 g / m. ² 3, composite long fiber non-woven fabric with a crimp number of 23 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. When the measured reference length of the obtained non-woven surface is set to 100 μm, the ratio of the maximum height in the block to the height (thickness) of the non-woven non-loaded state of 30% or more is 76%. The length of the 45-degree permeable oblique flow was 15 mm, the fourth durable water permeability index was 99%, and the re-seepage index was 0.15 g. The results are shown in Table 1 below. [Example 10] The first component was polyethylene terephthalate (PET) having a solution viscosity of 0.75 ηsp / c, and the second component was the same high-density polyethylene (HDPE) as in Example 1. The spunbond method was used to extrude the first component at a spinning temperature of 295 ° C at 0.54 g / min · hоle, the second component at 0.26 g / min · hоle, and the total output at 0.80 g / min・ The fiber with a ratio of hоle, the first component to the second component of about 2/1, and the filament group was extruded toward the moving capture surface using a high-speed air current traction device using air jets to prepare an eccentric sheath with an average fiber diameter of 18.7 μm. Core composite long fiber fabric. With respect to the obtained eccentric sheath-core type composite long fiber fabric, fibers were bonded to each other in the same manner as in Example 1 to obtain a basis weight of 18 g / m. ² 20, composite long fiber non-woven fabric with a crimp number of 20 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. The ratio of the maximum height in the block when the measured reference length of the obtained non-woven surface is 100 μm to the non-woven height (thickness) of 30% or more is 87%, and the non-woven is permeable to water The 45-degree oblique flow length is 15 mm, the fourth durable water permeability index is 99%, and the re-seepage index is 0.15 g. The results are shown in Table 1 below. [Example 11] Using the same components as in Example 1, the ejection amount of the first component was 0.24 g / min · hоle, the ejection amount of the second component was 0.56 g / min · hоle, and the total ejection amount was 0.8 g / min・ Hole, except that the ratio of the first component to the second component was set to 3/7. A eccentric sheath-core composite long-fiber fabric having an average fiber diameter of 17.9 μm was prepared in the same manner as in Example 1. With respect to the obtained eccentric sheath-core type composite long fiber fabric, fibers were bonded to each other in the same manner as in Example 1 to obtain a basis weight of 18 g / m. ² Composite long fiber non-woven fabric with a crimp number of 17 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 4 under the same coating conditions. When the measured reference length of the surface of the obtained non-woven fabric is set to 100 μm, the ratio of the maximum height in the block to the height (thickness) of the non-woven non-loaded state of 30% or more is 70%. The length of the 45-degree permeable oblique flow was 18 mm, the fourth durable water permeability index was 95%, and the re-seepage index was 0.18 g. The results are shown in Table 1 below. [Example 12] Using the same components as in Example 1, the ejection amount of the first component was 0.16 g / min · hоle, the ejection amount of the second component was 0.64 g / min · hоle, and the total ejection amount was 0.8 g / min・ Hole, except that the ratio of the first component to the second component was set to 1: 4, a eccentric sheath-core composite long-fiber fabric having an average fiber diameter of 18.7 μm was prepared in the same manner as in Example 1. With respect to the obtained eccentric sheath-core type composite long fiber fabric, fibers were bonded to each other in the same manner as in Example 1 to obtain a basis weight of 18 g / m. ² 5. Composite long fiber non-woven fabric with a crimp number of 5 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. When the measured reference length of the obtained surface of the non-woven fabric is set to 100 μm, the ratio of the maximum height in the block to the height (thickness) of the non-woven fabric in a load-free state of 30% or more is 52%. The length of the 45-degree permeable oblique flow was 22 mm, the fourth durable water permeability index was 85%, and the re-seepage index was 0.45 g. The results are shown in Table 1 below. [Example 13] Using the same components as in Example 1, the amount of the first component extruded was 0.40 g / min · hоle and the amount of the second component was 0.40 by a spunbond method at a spinning temperature of 220 ° C. g / min · hоle with a total ejection amount of 0.8 g / min · hоle and a ratio of the first component to the second component of 1: 1. The extruded filaments are stretched in the traction area by the suction force of the moving capturing surface, and then stacked on the moving capturing surface through a diffuser to prepare a side-by-side composite long fiber fabric with an average fiber diameter of 20.5 μm. Then, in the obtained parallel-type composite long-fiber fabric, fibers were bonded to each other in the same manner as in Example 1 to obtain a basis weight of 18 g / m. ² 2, 25 long / inch composite long fiber nonwoven fabric. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. When the measured reference length of the obtained non-woven surface is set to 100 μm, the ratio of the maximum height in the block to the height (thickness) of the non-woven non-loaded state of 30% or more is 90%. The length of the 45-degree permeable oblique flow was 14 mm, the fourth durable water permeability index was 99%, and the re-seepage index was 0.17 g. The results are shown in Table 1 below. [Example 14] An average fiber diameter of 20.5 μm and a basis weight of 30 g / m were obtained in the same manner as in Example 13. ² 2. Eccentric sheath-core composite long-fiber non-woven fabric with a crimp number of 25 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 1 under the same coating conditions. The ratio of the maximum height in the block when the measured reference length of the obtained non-woven surface is 100 μm to the non-woven height (thickness) of 30% or more is 89%. The non-woven is permeable to water The 45-degree oblique flow length was 14 mm, the fourth durable water permeability index was 99%, and the re-seepage index was 0.12 g. The results are shown in Table 1 below. [Example 15] Using a spinning head equipped with a figure-shaped irregular nozzle, a polypropylene (PP) having an MFR of 38 g / 10 min was extruded at a spinning temperature of 240 ° C and a discharge amount of 0.80 g / min · hоle. The filament group was extruded toward the moving capture surface by a high-speed air current traction device of air jet to obtain a long fiber fabric with an average fiber diameter of 18.7 μm. Next, the obtained long-fiber fabric was passed through a flat roll and an embossing roll (pattern specification: diameter 0.425 mm, staggered arrangement, horizontal pitch 2.1 mm, vertical pitch) set to a temperature of 135 ° C and a pressure of 60 kg / cm. 1.1 mm, crimp area ratio 6.3%), and the fibers were partially bonded to each other to obtain a basis weight of 25 g / m ² 2. Long fiber non-woven fabric with a crimp number of 28 per inch. Next, the obtained long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 4 under the same coating conditions. When the measured reference length of the obtained non-woven surface is set to 100 μm, the ratio of the maximum height in the block to the non-woven height (thickness) of 30% or more is 55%, and the non-woven is permeable to water The 45-degree oblique flow length was 23 mm, the fourth durable water permeability index was 89%, and the re-seepage index was 0.12 g. The results are shown in Table 1 below. [Table 1] A polypropylene (PP) resin with an MFR of 55 g / 10 min (measured under JIS-K7210 at a temperature of 230 ° C and a load of 2.16 kg) was extruded with a single component at a spinning temperature of 220 ° C by a spunbond method, The filament group was extruded toward a moving capture surface using a high-speed air current traction device using air jets to prepare a long fiber fabric with an average fiber diameter of 17.9 μm. Then, the obtained fabric was passed between a flat roller and an embossing roller at 141 ° C (pattern specification: circular with a diameter of 0.425 mm, staggered arrangement, a horizontal pitch of 2.1 mm, a vertical pitch of 1.1 mm, and a crimp area ratio of 6.3%). The fibers were bonded to each other to obtain a weight per unit area of 18 g / m ² Non-woven long fiber. Next, the obtained long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 4 under the same coating conditions. When the measured reference length of the obtained non-woven surface is set to 100 μm, the ratio of the maximum height in the block to the height (thickness) of the non-woven when the load is 30% or more is 40%, and the non-woven is permeable to water The 45-degree oblique flow length was 28 mm, the fourth durable water permeability index was 74%, and the infiltration index was 0.56 g. The results are shown in Table 2 below. [Comparative Example 2] The long-fiber nonwoven fabric obtained in Comparative Example 1 was passed through a continuous honeycomb pattern (tortoise shell pattern) of 0.9 mm and a line width of 0.1 mm on one side (pressing area ratio: 12.5%, pattern pitch: 2.8 mm in longitudinal direction) , Transverse 3.2 mm, depth 0.7 mm) between embossing rollers (80 ° C) and rubber rollers with a surface hardness of 60 degrees (JIS-A hardness) at 2 kg / cm ² Press the pattern. A soft long-fiber non-woven fabric having a high-density area and a raised center was obtained by pressing the periphery of the turtle shell. Next, the obtained long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 4 under the same coating conditions. When the measured reference length of the obtained non-woven surface is set to 100 μm, the ratio of the maximum height in the block to the height (thickness) of 30% or more when the non-woven is unloaded is 42%, and the non-woven is permeable to water The 45-degree oblique flow length was 27 mm, the fourth durable water permeability index was 80%, and the re-seepage index was 0.68 g. The results are shown in Table 2 below. [Comparative Example 3] Using the same components as in Example 1, the amount of the first component extruded was 0.72 g / min · hоle and the amount of the second component was 0.08 by a spunbond method at a spinning temperature of 220 ° C. g / min ・ hоle and a total ejection amount of 0.8 g / min · hоle, the ratio of the first component to the second component is 9/1, using a high-speed airflow traction device using air spray to extrude the length toward the moving capture surface Filament group to prepare an eccentric sheath-core composite long-fiber fabric with an average fiber diameter of 16.7 μm. Next, for the obtained eccentric sheath-core composite long-fiber fabric, the fibers were bonded to each other by hot air at a hot air temperature of 142 ° C and a hot air speed of 0.7 m / s to obtain a weight per unit area of 18 g / m. ² Non-woven composite long fiber with a crimp number of 0 per inch. Next, the obtained composite long-fiber nonwoven fabric was coated with the same water-permeable agent aqueous solution as in Example 4 under the same coating conditions. The ratio of the maximum height in the block when the measured reference length of the obtained non-woven surface is 100 μm to the non-woven height (thickness) of 30% or more is 48%, and the non-woven is permeable to water The 45-degree oblique flow length was 28 mm, the fourth durable water permeability index was 64%, and the re-seepage index was 0.52 g. The results are shown in Table 2 below. [Comparative Example 4] Using the same components as in Example 1, the amount of the first component extruded was 0.54 g / min · hоle and the amount of the second component was 0.26 by a spunbond method at a spinning temperature of 220 ° C. g / min · hоle and a total ejection amount of 0.8 g / min · hоle, the ratio of the first component to the second component is 2/1, and the high-speed airflow traction device using air spray is used to extrude the length toward the moving capture surface. Silk group to prepare a sheath-core composite long-fiber fabric with an average fiber diameter of 16.7 μm. Next, about the obtained fabric, fibers were adhered to each other in the same method and conditions as in Comparative Example 3, and then a water-permeant solution was applied to obtain a basis weight of 18 g / m. ² Non-woven composite long fiber with a crimp number of 0 per inch. When the measured reference length of the obtained nonwoven surface is set to 100 μm, the ratio of the maximum height in the block to the height (thickness) of the nonwoven when the load is 30% is 46%, and the water permeability of the nonwoven is 46%. The 45-degree oblique flow length was 26 mm, the fourth durable water permeability index was 73%, and the re-seepage index was 0.60 g. The results are shown in Table 2 below. [Table 2] [Industrial Applicability] The hydrophilic fluffy nonwoven fabric of the present invention has excellent water permeability, and therefore can be preferably used for the manufacture of sanitary materials. As for the sanitary material, it can be preferably used as a top sheet on the surface of disposable diapers, menstrual tampons or incontinence pads. In addition, the hydrophilic fluffy nonwoven fabric of the present invention is not limited to the above-mentioned applications, but can also be used in, for example, masks, stoves, tape base cloths, patch base cloths, wound base cloths, packaging materials, wipes, medical gowns, bandages, etc. , Clothing, sheet for skin care, etc.

FIG. 1 is a diagram for explaining the measurement of the maximum height (μm) in a unit block on the surface of a nonwoven fabric.

Claims (8)

A hydrophilic fluffy non-woven fabric, characterized in that it is composed of thermoplastic fibers and has the following non-woven surface structure, that is, a unit block defined by the X direction and the Y direction when the reference length of the measurement of the non-woven surface is 100 μm The ratio of the maximum height within the block to a height (thickness) of 30% or more in the Z direction of the non-woven without load is 60% or more per 40,000 blocks equivalent to the surface area of the non-woven 20mm × 20mm, and The non-woven fabric has a 45-degree oblique flow length value of 25 mm or less, and the fourth durable water permeability index is 85% or more. For example, the hydrophilic fluffy nonwoven fabric according to claim 1, wherein the above-mentioned hydrophilic fluffy nonwoven fabric has an orientation index in the thickness direction obtained by X-ray CT of 0.43 or less. For example, the hydrophilic fluffy nonwoven fabric according to claim 1 or 2, wherein the compression work of the hydrophilic fluffy nonwoven fabric is 0.20 gf‧cm / cm ² or more and 1.00 gf‧cm / cm ² or less. For example, the hydrophilic fluffy nonwoven fabric of claim 1 or 2, wherein the number of curls of the fibers constituting the hydrophilic fluffy nonwoven fabric is 5 to 45 per 2.54 cm (inch). For example, the hydrophilic fluffy non-woven fabric of claim 1 or 2, wherein the thermoplastic fibers are side-by-side or eccentric sheath-core composite fibers. The hydrophilic fluffy nonwoven fabric according to claim 1 or 2, wherein the thermoplastic fibers are polyolefin-based fibers. The hydrophilic fluffy nonwoven fabric according to claim 1 or 2, wherein the thermoplastic fibers are long fibers. A sanitary material using the hydrophilic fluffy non-woven fabric according to any one of claims 1 to 7.