Laminated nonwoven fabrics and sanitary materials

Abstract

A layered nonwoven fabric according to the present invention is obtained by layering at least one nonwoven fabric layer (A) formed from first thermoplastic resin fibers and at least one nonwoven fabric layer (B) formed from second thermoplastic resin fibers. The ratio (Db / Da) of an average single-fiber diameter Db of the fibers that constitute the nonwoven fabric layer (B) with respect to an average single-fiber diameter Da of the fibers that constitute the nonwoven fabric layer (A) is not less than 1.1. The nonwoven fabric layer (B) is layered on at least one outermost surface. Further, the contact angle of the layered nonwoven fabric with water on the front surface thereof is not more than 30°. The contact angle of the layered nonwoven fabric with water on the rear surface thereof is not more than 30°.　This layered nonwoven fabric has water-absorbing / quick-drying properties sufficient to enable the fabric to be utilized as a sanitary nonwoven fabric. By employing this layered nonwoven fabric as at least a portion of a sanitary material, a sanitary material having excellent water-absorbing properties and excellent quick-drying properties can be obtained.

Description

[Technical Field]

[0001] The present invention relates to a laminated nonwoven fabric that has excellent water absorption and quick-drying properties and is particularly suitable for use as a sanitary material, and to a sanitary material using the same. [Background technology]

[0002] In recent years, various studies have been conducted on nonwoven fabrics used in sanitary materials such as disposable diapers, sanitary napkins, and masks to improve the comfort of the wearer when wearing the sanitary materials. In particular, the surface components that come into direct contact with the skin must be both water-absorbent (rapidly absorbing moisture) and quick-drying (transferring absorbed moisture from the outermost layer to keep the surface dry and free of excessive moisture).

[0003] Effective methods for imparting water absorbency to nonwoven fabrics include using nonwoven fabrics made of hydrophilic fibers and subjecting nonwoven fabrics to hydrophilic treatment. However, these techniques have the problem of being inferior in quick-drying properties because they do not have the function of transferring absorbed moisture from the outermost layer.

[0004] Against this background, a laminated nonwoven fabric has been proposed that has a laminated structure of fiber layers containing long fibers, with the aim of imparting moisture-absorbing and quick-drying properties to the nonwoven fabric. The laminated nonwoven fabric is composed of a hydrophobic layer containing hydrophobic fibers and a hydrophilic layer containing hydrophilic fibers with inter-fiber distances and aspect ratios within specific ranges, with the hydrophobic layer disposed on the surface of the nonwoven fabric (see Patent Document 1).

[0005] Furthermore, as a technique for stacking nonwoven fabrics, an absorbent article has been proposed that includes a laminated nonwoven fabric in which first and third nonwoven fabric constituent layers containing fibers having an average single fiber diameter within a specific range and a second nonwoven fabric constituent layer containing fibers with an even smaller average single fiber diameter are disposed between the first and third nonwoven fabric layers (see Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2018 / 167881 [Patent Document 2] Special Publication No. 2013-518698 Summary of the Invention [Problem to be solved by the invention]

[0007] In the technology of Patent Document 1, a hydrophilic gradient is formed in the thickness direction of the nonwoven fabric, thereby achieving a certain level of water absorption performance even when a hydrophobic layer is arranged on the outermost surface. However, because the outermost surface is a hydrophobic layer, the performance is insufficient for absorbing large amounts of water such as urine, and quick-drying properties are also insufficient because liquid tends to remain.

[0008] On the other hand, the technology of Patent Document 2 relates to a laminated nonwoven fabric having a structure in which nonwoven fabric layers composed of fibers with different average monofilament diameters are laminated. However, since the nonwoven fabric is used in barrier cuffs and has a structure that prevents fluid from seeping through, i.e., it is impermeable to moisture, liquid is likely to remain on the surface of the nonwoven fabric. For this reason, the technology of Patent Document 2 has insufficient water absorbency and quick-drying properties.

[0009] Therefore, an object of the present invention is to provide a laminated nonwoven fabric that has sufficient water absorbency and quick-drying properties to maintain comfort when worn, and that is suitable for use as a sanitary material. [Means for solving the problem]

[0010] As a result of further investigations, the inventors of the present invention have confirmed that, although increasing the hydrophilicity of the nonwoven fabric itself is effective in increasing the water absorbency of the nonwoven fabric, when a nonwoven fabric with only increased hydrophilicity is used, the surface remains wet and does not dry, resulting in problems such as poor comfort when worn. On the other hand, when hydrophobic fibers are used in part of the nonwoven fabric or a hydrophilicity gradient is imparted in the thickness direction in order to increase quick-drying properties, the water absorbency of the nonwoven fabric surface is ultimately reduced, resulting in problems such as residual liquid.

[0011] Therefore, the present inventors conducted extensive research to achieve the above-mentioned object, and as a result, discovered that in a laminated nonwoven fabric, by setting the ratio of the average single fiber diameters of the fibers constituting each nonwoven fabric layer within a specific range, laminating each nonwoven fabric layer in a specific configuration, and further setting the contact angle of each nonwoven fabric layer with water within a specific range, a nonwoven fabric having sufficient water absorbency and quick-drying properties to maintain comfort when worn can be obtained, and this led to the completion of the present invention.

[0012] The laminated nonwoven fabric of the present invention is a laminated nonwoven fabric in which at least one nonwoven fabric layer (A) made of a first thermoplastic resin fiber and at least one nonwoven fabric layer (B) made of a second thermoplastic resin fiber are laminated together, wherein the ratio (Db / Da) of the average single fiber diameter Db of the fibers making up the nonwoven fabric layer (B) to the average single fiber diameter Da of the fibers making up the nonwoven fabric layer (A) is 1.1 or more, the nonwoven fabric layer (B) is laminated on at least one outermost surface, and further, the contact angle with water of the front surface of the laminated nonwoven fabric is 30° or less, and the contact angle with water of the back surface of the laminated nonwoven fabric is 30° or less.

[0013] The sanitary material of the present invention is at least partially composed of the above-mentioned laminated nonwoven fabric. [Effects of the Invention]

[0014] The laminated nonwoven fabric of the present invention has sufficient water absorption and quick-drying properties for use as a nonwoven fabric for sanitary materials. By using the laminated nonwoven fabric of the present invention as at least a part of a sanitary material, a sanitary material having excellent water absorption and quick-drying properties can be obtained.

[0015] The laminated nonwoven fabric of the present invention can be used as a part of sanitary materials such as disposable diapers, sanitary napkins, gauze, bandages, masks, gloves, and adhesive bandages. DETAILED DESCRIPTION OF THE INVENTION

[0016] The laminated nonwoven fabric of the present invention is a laminated nonwoven fabric comprising at least one nonwoven fabric layer (A) made of first thermoplastic resin fibers and at least one nonwoven fabric layer (B) made of second thermoplastic resin fibers, wherein the ratio (Db / Da) of the average single fiber diameter Db of the second thermoplastic resin fibers making up nonwoven fabric layer (B) to the average single fiber diameter Da of the first thermoplastic resin fibers making up nonwoven fabric layer (A) is 1.1 or more, nonwoven fabric layer (B) is laminated on at least one outermost surface, and further, the contact angle with water of the front surface of the laminated nonwoven fabric is 30° or less, and the contact angle with water of the back surface of the laminated nonwoven fabric is 30° or less. The components thereof are described in detail below.

[0017] [Thermoplastic resin fiber] The laminated nonwoven fabric of the present invention comprises a nonwoven fabric layer (A) made of a first thermoplastic resin fiber and a nonwoven fabric layer (B) made of a second thermoplastic resin fiber.

[0018] In the first thermoplastic resin fiber and the second thermoplastic resin fiber, the term "thermoplastic resin fiber" refers to a fiber made of a thermoplastic resin. The thermoplastic resin may be one type or may be made of multiple thermoplastic resins.

[0019] In the present invention, examples of thermoplastic resins used for the thermoplastic resin fiber include aromatic polyester polymers and copolymers thereof such as "polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate," aliphatic polyester polymers and copolymers thereof such as "polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalerate copolymer, polycaprolactone," polyamide 6, polyamide 66, poly Examples of suitable polymers include aliphatic polyamide polymers and copolymers thereof, such as polyamide 610, polyamide 10, polyamide 12, and polyamide 6-12; polyolefin polymers and copolymers thereof, such as polypropylene, polyethylene, polybutene, and polymethylpentene; water-insoluble ethylene-vinyl alcohol copolymer polymers containing 25 mol % to 70 mol % ethylene units; and polystyrene, polydiene, chlorine-based, polyolefin, polyester, polyurethane, polyamide, and fluorine-based elastomer polymers. The polymers may contain various additives, such as inorganic substances, such as titanium oxide, silica, and barium oxide; colorants, such as carbon black, dyes, and pigments; flame retardants, fluorescent brighteners, antioxidants, and ultraviolet absorbers.

[0020] In the present invention, the thermoplastic resin is preferably a thermoplastic resin containing 0.5% by mass or more of a fatty acid amide compound. By setting the content of the fatty acid amide compound to preferably 0.5% by mass or more, more preferably 0.7% by mass or more, and even more preferably 1.0% by mass or more, the fatty acid amide compound acts as a lubricant on the fiber surface, resulting in a spunbond nonwoven fabric with excellent tactile feel. Note that there is no particular upper limit to the content of the fatty acid amide compound in the present invention, but from the viewpoints of cost and productivity, it is preferably 5.0% by mass or less.

[0021] In the present invention, when the thermoplastic resin contains the fatty acid amide compound, the carbon number of the fatty acid amide compound is preferably from 15 to 50. Examples of the fatty acid amide compound having from 15 to 50 carbon atoms include saturated fatty acid monoamide compounds, saturated fatty acid diamide compounds, unsaturated fatty acid monoamide compounds, and unsaturated fatty acid diamide compounds. The number of carbon atoms in the present invention means the number of carbon atoms contained in the molecule, and specifically includes palmitic acid amide, palmitoleic acid amide, stearic acid amide, oleic acid amide, elaidic acid amide, vaccenic acid amide, linoleic acid amide, linolenic acid amide, pinolenic acid amide, eleostearic acid amide, stearidonic acid amide, bosseopentaenoic acid amide, arachidic acid amide, gadoleic acid amide, eicosenoic acid amide, eicosadienoic acid amide, mead acid amide, eicosatrienoic acid amide, arachidonic acid amide, eicosatetraenoic acid amide, eicosapentaenoic acid amide, heneicosyl acid amide, behenic acid amide, erucic acid amide, docosadienoic acid amide, adrenic acid amide, osbondoic acid amide, sardine acid amide, docosahexaenoic acid Examples of the fatty acid amide include amide, lignoceric acid amide, nervonic acid amide, tetracosapentaenoic acid amide, nisinic acid amide, cerotic acid amide, montanic acid amide, melissic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, methylene bislauric acid amide, ethylene bisstearic acid amide, ethylene bisoleic acid amide, ethylene bishydroxystearic acid amide, ethylene bisbehenic acid amide, ethylene biserucic acid amide, hexamethylene bisstearic acid amide, hexamethylene bisbehenic acid amide, hexamethylene hydroxystearic acid amide, distearyl adipic acid amide, distearyl sebacic acid amide, and hexamethylene bisoleic acid amide, and a combination of these may also be used. By setting the carbon number of the fatty acid amide compound to preferably 15 or more, more preferably 23 or more, and even more preferably 30 or more, excessive precipitation of the fatty acid amide compound on the fiber surface is suppressed, resulting in excellent spinnability and processing stability and maintaining high productivity.Furthermore, by setting the carbon number of the fatty acid amide compound to preferably 50 or less, more preferably 45 or less, and even more preferably 42 or less, the fatty acid amide compound is appropriately precipitated on the fiber surface, resulting in a spunbond nonwoven fabric with excellent tactile feel. The carbon number of the fatty acid amide compound is preferably 15 to 50, more preferably 23 to 45, and even more preferably 30 to 42.

[0022] In the present invention, the thermoplastic resin fiber may be a single-component fiber or a composite fiber made by combining two or more types of resins. When the thermoplastic resin fiber is a composite fiber, it may be appropriately selected from a core-sheath type, an island-in-sea type, a side-by-side type, an eccentric core-sheath type, etc. In the present invention, the thermoplastic resin fiber may be a split-type composite fiber in which a part or the entire fiber is split into multiple fibers from a single fiber.

[0023] In the present invention, the cross-sectional shape of the thermoplastic resin fiber may be not only a round cross-section but also an irregular cross-section such as a triangular cross-section, a flat cross-section, a hexagonal cross-section, a hollow cross-section, etc. When the laminated nonwoven fabric of the present invention is used for a hygienic material, a round cross-section is preferred because it allows high productivity and is excellent in flexibility.

[0024] In the present invention, it is preferable that all thermoplastic resin fibers have a contact angle with water of less than 90°. The contact angle with water of thermoplastic resin fibers is a different index from the contact angle with water of nonwoven fabrics described below; a contact angle of 90° or more indicates hydrophobicity, and a contact angle of less than 90° indicates hydrophilicity. In the present invention, the contact angle with water of thermoplastic resin fibers is determined, for example, by measuring the angle between the air interface of a water droplet and the fiber when a very small amount (15 pL) of water droplet is applied to the surface of the thermoplastic resin fibers taken out of nonwoven fabric that has been left in a room at room temperature of 20°C and a relative humidity of 65% for 24 hours or more using an automatic contact angle meter equipped with an inkjet water droplet ejection unit.

[0025] The first thermoplastic resin fiber and the second thermoplastic resin fiber may be made of the same or different thermoplastic resins and have the same fiber cross section.

[0026] [First nonwoven fabric layer (A) made of thermoplastic resin fibers] In the laminated nonwoven fabric of the present invention, the nonwoven fabric layer (A) is composed of a first thermoplastic resin fiber.

[0027] In the present invention, the nonwoven fabric layer (A) is preferably made of a long-fiber nonwoven fabric, which allows for high productivity and excellent mechanical properties.

[0028] In the present invention, the average single fiber diameter of the first thermoplastic resin fibers constituting the nonwoven fabric layer (A) is preferably 1.0 μm to 25.0 μm. By setting the average single fiber diameter of the first thermoplastic resin fibers to preferably 1.0 μm or more, more preferably 1.5 μm or more, moisture can be easily transferred to the adjacent water absorbent core when used as a sanitary material. Furthermore, by setting the average single fiber diameter of the first thermoplastic resin fibers to preferably 25.0 μm or less, more preferably 20.0 μm or less, and even more preferably 16.0 μm or less, the water absorption of the nonwoven fabric layer (A) is improved by the capillary effect. The average single fiber diameter of the first thermoplastic resin fibers is more preferably 1.0 μm to 20.0 μm, and even more preferably 1.5 μm to 16.0 μm.

[0029] The average single fiber diameter is determined as follows.

[0030] First, an image of the cross section of the fibers constituting the nonwoven fabric layer (A) is taken with a scanning electron microscope at a magnification that allows observation of a single fiber. Next, using the taken image and image analysis software (e.g., "WinROOF2015" manufactured by Mitani Shoji Co., Ltd.), the area Af formed by the cross-sectional contour of the single fiber is measured, and the diameter of a perfect circle having the same area as this area Af is calculated. This is measured for 20 single fibers randomly extracted from the same nonwoven fabric layer, and a simple number average is calculated. The value, in units of μm, is rounded to one decimal place, and this value is the average single fiber diameter referred to in the present invention.

[0031] [Nonwoven fabric layer (B) made of second thermoplastic resin fibers] In the laminated nonwoven fabric of the present invention, the nonwoven fabric layer (B) is composed of a second thermoplastic resin fiber. In the present invention, the nonwoven fabric layer (B) is preferably composed of a long-fiber nonwoven fabric. When the nonwoven fabric layer (B) is composed of a long-fiber nonwoven fabric, the nonwoven fabric has high productivity and excellent mechanical properties.

[0032] In the present invention, the average single fiber diameter of the second thermoplastic resin fibers constituting the nonwoven fabric layer (B) is preferably 3.0 μm to 30.0 μm. By setting the average single fiber diameter of the second thermoplastic resin fibers to preferably 3.0 μm or more, more preferably 5.0 μm or more, and even more preferably 8.0 μm or more, the fibers of the nonwoven fabric layer are not too dense, resulting in a nonwoven fabric with appropriate water permeability. Furthermore, by setting the average single fiber diameter of the second thermoplastic resin fibers to preferably 30.0 μm or less, more preferably 27.0 μm or less, and even more preferably 25.0 μm or less, the nonwoven fabric has a good surface feel when used as a sanitary material. The average single fiber diameter of the second thermoplastic resin fibers is more preferably 5.0 μm to 27.0 μm, and even more preferably 8.0 μm to 25.0 μm.

[0033] [Average single fiber diameter of nonwoven fabric layer (A) and nonwoven fabric layer (B)] It is important that the laminated nonwoven fabric of the present invention has a ratio (Db / Da, hereinafter sometimes simply referred to as the average single fiber diameter ratio) of the average single fiber diameter Da of the first thermoplastic resin fibers constituting the nonwoven fabric layer (A) to the average single fiber diameter Db of the second thermoplastic resin fibers constituting the nonwoven fabric layer (B) of 1.1 or more.

[0034] The average single fiber diameter ratio referred to here is a value obtained by measuring the average single fiber diameter Da of the first thermoplastic resin fiber constituting the nonwoven fabric layer (A) and the average single fiber diameter Db of the second thermoplastic resin fiber constituting the nonwoven fabric layer (B) using the following method, calculating the ratio (Db / Da), and rounding it to one decimal place.

[0035] First, an image of the cross section of the fibers constituting the nonwoven fabric layer (A) or the nonwoven fabric layer (B) is taken with a scanning electron microscope at a magnification that allows observation of a single fiber. Next, using the taken image and image analysis software (such as "WinROOF2015" manufactured by Mitani Shoji Co., Ltd.), the area Af formed by the cross-sectional contour of the single fiber is measured, and the diameter of a perfect circle having the same area as this area Af is calculated. This is measured for 20 single fibers randomly extracted from the same nonwoven fabric layer, and a simple number average is calculated. The value, in units of μm, is rounded to one decimal place, and this value is the average single fiber diameter referred to in the present invention.

[0036] In general, in a nonwoven fabric, the size of the voids between the fibers varies depending on the average single fiber diameter of the constituent fibers. Therefore, when nonwoven fabric layers with different average single fiber diameters are stacked, the nonwoven fabric layers have different inter-fiber void sizes. When moisture adheres to the nonwoven fabric, the moisture absorbed in the nonwoven fabric layer made of thick fibers can be quickly transferred to the nonwoven fabric layer made of thin fibers due to the difference in capillary effect. Furthermore, as a result of extensive research, the inventors have found that by setting the average single fiber diameter ratio within a specific range, not only can the water absorption effect be improved due to the difference in capillary effect, but also quick-drying properties can be imparted to the surface of the nonwoven fabric layer made of thick fibers.

[0037] Therefore, by setting the average single fiber diameter ratio (Db / Da) to 1.1 or more, preferably 1.2 or more, and more preferably 1.3 or more, the above-mentioned capillary effect can be exerted, resulting in good water absorbency and quick-drying properties in the nonwoven fabric layer (B). There is no particular upper limit to the average single fiber diameter ratio in the present invention, but from the viewpoints of process stability and productivity, it is preferably 10.0 or less.

[0038] [Laminated nonwoven fabric] The laminated nonwoven fabric of the present invention is a laminated nonwoven fabric in which at least one layer of each of the nonwoven fabric layers (A) and (B) is laminated, and it is important that the nonwoven fabric layer (B) is laminated as the outermost layer of at least one of the layers. By laminating the nonwoven fabric layer (B) having a large average single fiber diameter and large inter-fiber voids within the nonwoven fabric layer as the outermost layer in this manner, when moisture is absorbed on the nonwoven fabric layer (B) side, the moisture is quickly transferred to the nonwoven fabric layer (A), and quick-drying properties can be obtained on the outermost surface of the nonwoven fabric layer (B) side.

[0039] It is important that the laminated nonwoven fabric of the present invention has a contact angle with water of 30° or less on the front surface of the laminated nonwoven fabric and a contact angle with water of 30° or less on the back surface of the laminated nonwoven fabric.

[0040] When the contact angle with water on the surface of the laminated nonwoven fabric is 30° or less, preferably 20° or less, and more preferably 10° or less, the nonwoven fabric is hydrophilic, so that moisture that comes into contact with the surface of the nonwoven fabric is easily absorbed by the nonwoven fabric, resulting in a nonwoven fabric with excellent water absorbency. When the contact angle with water on the back surface of the laminated nonwoven fabric is 30° or less, preferably 20° or less, and more preferably 10° or less, the entire nonwoven fabric is hydrophilic, so that moisture that comes into contact with the surface of the nonwoven fabric is easily absorbed by the nonwoven fabric, resulting in a nonwoven fabric with excellent water absorbency. The lower limit of the contact angle with water in the present invention is 0°. A contact angle with water of 0° refers to a state in which all water has been absorbed by the nonwoven fabric in the following measurement method.

[0041] The contact angle with water can be controlled by the hydrophilicity of the thermoplastic resin used in the fibers constituting the laminated nonwoven fabric and by applying a hydrophilic oil agent in a post-process. For example, the higher the hydrophilicity of the thermoplastic resin and the greater the amount of hydrophilic oil agent applied, the smaller the contact angle with water tends to be.

[0042] The contact angle of the laminated nonwoven fabric layer with water in the present invention refers to a value measured and calculated by the following method: The surface on which the nonwoven fabric layer (B) is laminated on the outermost surface is defined as the first surface, and the surface opposite thereto is defined as the second surface. (1) The laminated nonwoven fabric is left in a room at a room temperature of 20°C and a relative humidity of 65% for 24 hours or more. (2) The laminated nonwoven fabric that has been subjected to the above treatment is placed on the stage of a contact angle meter installed in the same room so that the nonwoven fabric layer (B) becomes the measurement surface. (3) A 2 μL droplet of ion-exchanged water is created on the tip of the needle and applied to the nonwoven fabric. (4) The contact angle with the droplet is determined from the image taken 2 seconds after the droplet hits the nonwoven fabric. If all the water is absorbed by the nonwoven fabric within 2 seconds, the interface between the droplet and the air is determined to be on the same plane as the surface of the nonwoven fabric layer, and the contact angle with water is defined as 0°. (5) For each level, measurements are taken five times at different measurement positions, and the arithmetic mean value is taken as the contact angle between the first surface and water. (6) The laminated nonwoven fabric that has been treated in the same manner as in (1) is set so that the nonwoven fabric layer (B) faces back, and the above operations (2) to (5) are repeated, and the arithmetic average value is taken as the contact angle between the second surface and water.

[0043] The laminated nonwoven fabric of the present invention has a minimum breaking strength σ among the breaking strengths measured by rotating the laminated nonwoven fabric in the plane from an arbitrary direction of 0° to 180° in 22.5° increments. min Maximum breaking strength σ max The ratio (σ max / σ min (hereinafter sometimes simply referred to as "breaking strength ratio") is preferably 1.2 to 4.0. By setting the breaking strength ratio to preferably 1.2 or more, more preferably 1.3 or more, the fibers are oriented in one direction within the plane of the nonwoven fabric, allowing absorbed water to spread in the fiber orientation direction due to the capillary effect, thereby achieving higher water absorption and quick-drying properties. Furthermore, by setting the breaking strength ratio to preferably 4.0 or less, more preferably 3.5 or less, there are no angles with extremely low breaking strength, which prevents the nonwoven fabric from breaking during processing or product processing. The breaking strength ratio of the laminated nonwoven fabric of the present invention is more preferably 1.3 to 3.5.

[0044] The breaking strength ratio of the laminated nonwoven fabric in the present invention refers to a value measured and calculated by the following method based on "6.3 Tensile strength and elongation (ISO method)" of JIS L1913:2010 "Testing methods for general nonwoven fabrics." (1) Any one direction of the laminated nonwoven fabric is set to 0°, and a test piece measuring 300 mm long x 25 mm wide is cut out so that the longitudinal direction coincides with the above direction, and three test pieces are taken from different locations. (2) Set the test piece in the tensile testing machine with a gripping distance of 200 mm. (3) Conduct a tensile test at a tensile speed of 100 m / min, measure the strength at break [N] for three test pieces, and use the arithmetic mean value as the breaking strength σ. (4) Using the direction rotated 22.5° clockwise within the plane of the laminated nonwoven fabric relative to any direction set at 0° as the axis, cut out a test piece measuring 300 mm in length and 25 mm in width so that the longitudinal direction coincides with the above-mentioned axial direction, and take three test pieces at different locations. Then, repeat the above steps (2) to (3) to calculate the breaking strength σ. (5) The above operation (4) is repeated until the in-plane rotation angle of the laminated nonwoven fabric reaches 180°, and the breaking strength σ at each angle is calculated. (6) The minimum breaking strength σ among the breaking strength σ calculated by the above method min Maximum breaking strength σ max The ratio (σ max / σ min ) is calculated and used as the breaking strength ratio of the laminated nonwoven fabric.

[0045] The laminated nonwoven fabric of the present invention may contain a nonwoven fabric layer other than the nonwoven fabric layer (A) and the nonwoven fabric layer (B) as long as the effects of the present invention are not impaired. When a nonwoven fabric layer other than the nonwoven fabric layer (A) and the nonwoven fabric layer (B) is contained, it is preferable that the fibers constituting the nonwoven fabric layer are hydrophilic so as not to impair water absorbency.

[0046] In the laminated nonwoven fabric of the present invention, it is preferable that the nonwoven fabric layer (B) is laminated on one outermost surface and the nonwoven fabric layer (A) is laminated on the other outermost surface. By laminating the nonwoven fabric layer (A) on the other outermost surface, it becomes easier to transfer absorbed moisture to a substance in contact with the nonwoven fabric layer (A). For example, in applications such as diapers, it becomes easier to transfer moisture to a water-absorbing body, improving the quick-drying properties of the laminated nonwoven fabric.

[0047] The laminated nonwoven fabric of the present invention preferably has a water absorption rate of 20 seconds or less, measured on the first surface on which the nonwoven fabric layer (B) is arranged as the outermost surface. By setting the water absorption rate to preferably 20 seconds or less, more preferably 15 seconds or less, and even more preferably 10 seconds or less, the nonwoven fabric has good performance in removing moisture adhering to the surface, i.e., has excellent water absorption.

[0048] The water absorption rate referred to here is measured based on "7.1.1 Drop Method" in JIS L1907:2010 "Testing Method for Water Absorption of Textile Products." A single drop of water is dropped onto the laminated nonwoven fabric, and the time it takes for the water to be absorbed and the specular reflection on the surface to disappear is measured. This time is measured at 10 different points, and the simple average is calculated. The value is expressed in seconds and rounded to the nearest decimal place, and this value is the water absorption rate referred to in the present invention.

[0049] The basis weight of the laminated nonwoven fabric of the present invention is 10 g / m 2 ~100g / m 2 The basis weight is preferably 10 g / m 2 More preferably, 13 g / m 2 More preferably, 15 g / m 2 By adjusting the weight to the above, a laminated nonwoven fabric having a mechanical strength sufficient for practical use can be obtained. 2 Less than 50 g / m 2 By setting the weight as follows, a laminated nonwoven fabric having a suitable flexibility suitable for use as a nonwoven fabric for sanitary materials can be obtained. The weight per unit area of the laminated nonwoven fabric of the present invention is more preferably 13 g / m 2 ~50g / m 2 is.

[0050] The basis weight (g / m 2 ) is based on "6.2 Mass per unit area" of JIS L1913:2010 "General nonwoven fabric test method", 20cm x 25cm test pieces are taken, three pieces per 1m width of the sample, and the mass (g) of each is measured under standard conditions, and the mass per 1m is calculated from the average value. 2 This refers to the mass per unit mass.

[0051] In the laminated nonwoven fabric of the present invention, the nonwoven fabric layer (A) and the nonwoven fabric layer (B) are preferably integrated together, where "integrated" means that these layers are bonded together by entanglement of fibers, fixation with components such as adhesives, or fusion of the thermoplastic resins that make up each layer.

[0052] In the laminated nonwoven fabric of the present invention, both the nonwoven fabric layer (A) and the nonwoven fabric layer (B) preferably consist of long-fiber nonwoven fabrics.

[0053] The laminated nonwoven fabric of the present invention may be provided with a hydrophilizing agent in order to increase the water absorbency. Examples of the hydrophilizing agent include surfactants, among which nonionic surfactants are preferred.

[0054] [Hygiene materials] The sanitary material of the present invention is at least partially composed of the laminated nonwoven fabric. This results in a sanitary material with excellent water absorption and quick-drying properties. The sanitary material of the present invention is primarily a disposable item used for health-related purposes, such as medical care and nursing. Examples of the sanitary material of the present invention include disposable diapers, sanitary napkins, gauze, bandages, masks, gloves, adhesive bandages, and the like, and also includes components thereof, such as the top sheet, back sheet, and side gathers of disposable diapers.

[0055] Among these, a hygienic material in which the outermost surface of the laminated nonwoven fabric layer (B) is arranged facing the wearer's skin side is more preferred, since moisture adhering to the skin side can be immediately absorbed into the interior of the laminated nonwoven fabric, thereby reducing discomfort to the wearer.

[0056] For example, when the sanitary material is a disposable diaper and the laminated nonwoven fabric is used as the top sheet of the disposable diaper, if the outermost surface of the laminated side of the nonwoven fabric layer (B) is arranged facing the wearer's skin, sweat produced during wear and urine excreted will be quickly absorbed and the liquid will be quickly transferred to the nonwoven fabric layer (A), keeping the surface dry and free from excessive moisture.

[0057] When the sanitary material is a mask and the laminated nonwoven fabric is used as the inner layer of the mask, and the outermost surface of the side on which the nonwoven fabric layer (B) is laminated is arranged facing the wearer's skin, even if sweat or exhaled air condenses and moisture adheres to the skin side, it is quickly absorbed into the laminated nonwoven fabric, and the skin side can be kept dry and free from excessive moisture.

[0058] [Manufacturing method of laminated nonwoven fabric] Next, a preferred embodiment for producing the laminated nonwoven fabric of the present invention will be specifically described.

[0059] The method for producing the nonwoven fabric layers (A) and (B) constituting the laminated nonwoven fabric of the present invention can be selected from known production methods such as the spunbond method, meltblowing method, and staple fiber carding method.

[0060] Among these, the spunbond method is preferred because of its excellent productivity.

[0061] A preferred embodiment for producing the laminated nonwoven fabric of the present invention based on the spunbond method will be described below, but the present invention is not limited to this.

[0062] The spunbonding method is a method for producing nonwoven fabrics in which a thermoplastic resin raw material is melted, spun from a spinneret, cooled and solidified, and the resulting yarn is pulled and stretched by an ejector, collected on a moving net to form a nonwoven fiber web, and then thermally bonded.

[0063] In the spunbonding method, various shapes of spinneret and ejector can be used, such as round and rectangular shapes. Among them, it is preferable to use a combination of a rectangular spinneret and a rectangular ejector, from the viewpoints that the amount of compressed air used is relatively small and fusion and abrasion between the yarns are unlikely to occur.

[0064] When producing the laminated nonwoven fabric of the present invention, the spinning temperature is preferably set to (the melting temperature of the thermoplastic resin raw material + 10°C) or higher and (the melting temperature of the thermoplastic resin raw material + 100°C) or lower. By setting the spinning temperature within the above range, a stable molten state can be achieved, and excellent spinning stability can be obtained.

[0065] The spun yarn is then cooled. Examples of methods for cooling the spun yarn include forcibly blowing cold air onto the yarn, naturally cooling at the ambient temperature around the yarn, and adjusting the distance between the spinneret and the ejector. Alternatively, a combination of these methods can be used. The cooling conditions can be appropriately adjusted taking into account the output per hole of the spinneret, the spinning temperature, the ambient temperature, and the like.

[0066] Next, the cooled and solidified yarn is drawn and stretched by compressed air jetted from an ejector.

[0067] In the laminated nonwoven fabric of the present invention, it is important to control the average single fiber diameter of the fibers constituting the nonwoven fabric layer (A) and the nonwoven fabric layer (B).

[0068] The average single fiber diameter of the fiber is determined by the output rate per nozzle hole of the spinneret and the drawing speed, i.e., the spinning speed. Therefore, it is preferable to determine the output rate and the spinning speed according to the desired average single fiber diameter.

[0069] The spinning speed is preferably 2000 m / min or more, more preferably 3000 m / min or more. By setting the spinning speed to 2000 m / min or more, high productivity is achieved, and the orientation and crystallization of the fibers is promoted, allowing long fibers with high strength to be obtained.

[0070] The filament yarn thus drawn by pulling is collected on a moving net to be formed into a sheet, which is then subjected to a thermal bonding step.

[0071] The laminated nonwoven fabric of the present invention is a laminated nonwoven fabric obtained by laminating at least one layer each of nonwoven fabric layer (A) and nonwoven fabric layer (B). Examples of methods for laminating the two nonwoven fabric layers include a method in which a nonwoven fabric layer obtained by collecting a second thermoplastic resin fiber by a spunbonding method is continuously collected in-line on a nonwoven fabric layer obtained by collecting a first thermoplastic resin fiber on a collecting net by a spunbonding method, and then laminated together; and a method in which nonwoven fabric layer (A) and nonwoven fabric layer (B) obtained separately are overlapped offline and then laminated together by thermocompression bonding or the like. Among these, a method in which a nonwoven fabric layer obtained by collecting a second thermoplastic resin fiber by a spunbonding method is continuously collected in-line on a nonwoven fabric layer obtained by collecting a first thermoplastic resin fiber on a collecting net by a spunbonding method, and then laminated together by thermal bonding, is preferred because of its excellent productivity.

[0072] Methods for laminating and integrating the laminated nonwoven fabric of the present invention by thermal bonding include thermal bonding methods using various rolls, such as a thermal embossing roll, which is a pair of upper and lower rolls each having an engraving (uneven portion) on their surface, a thermal embossing roll consisting of a combination of a roll with one flat (smooth) surface and a roll with an engraving (uneven portion) on the other roll surface, and a thermal calendar roll consisting of a pair of upper and lower flat (smooth) rolls, as well as thermocompression bonding methods such as ultrasonic bonding, which involves thermal welding using ultrasonic vibrations from a horn.

[0073] When the laminated nonwoven fabric of the present invention is produced by thermocompression bonding, the multiple nonwoven fabric layers are sufficiently bonded together, which is preferable because the mechanical strength of the laminated nonwoven fabric is increased.

[0074] The laminated nonwoven fabric of the present invention can be laminated and integrated by thermal bonding using a so-called air-through method, which involves blowing hot air onto the laminated nonwoven fabric. When the laminated nonwoven fabric of the present invention is produced by the air-through method, it is preferred because it has a high bulk and an excellent texture.

[0075] A hydrophilizing agent may be applied to the laminated nonwoven fabric obtained in this manner before winding. Methods for applying the hydrophilizing agent to the laminated nonwoven fabric include application with a kiss roll or spray, and dip coating. Application with a kiss roll is preferred as a method for applying the hydrophilizing agent to the laminated nonwoven fabric because of the uniformity and ease of controlling the amount of application.

[0076] In the laminated nonwoven fabric of the present invention, it is sufficient that the nonwoven fabric layer (B) is laminated on at least one outermost surface, and the number and combination of layers can be arbitrarily selected depending on the purpose. [Example]

[0077] Next, the present invention will be described in detail based on examples. However, the present invention is not limited to these examples. In addition, in measuring each physical property, unless otherwise specified, the measurement was performed according to the above-mentioned method.

[0078] (1) Ratio of the average single fiber diameter Db of the second thermoplastic resin fiber to the average single fiber diameter Da of the first thermoplastic resin fiber (Db / Da) For each thermoplastic resin fiber, a fiber sample was randomly taken from the nonwoven fiber web collected on a net, and the fiber cross section was imaged using a Hitachi High-Technologies Corporation S-5500 scanning electron microscope at a magnification that allowed individual fibers to be observed. Then, using Mitani Corporation's WinROOF2015 image analysis software, the area Af formed by the cross-sectional contour of the single fiber was measured, and the diameter of a perfect circle with the same area Af was calculated. This was measured for 20 single fibers randomly extracted from the same nonwoven fabric layer, and a simple number average was calculated. The unit was μm, and the average single fiber diameter was calculated by rounding to the nearest 1 decimal place.

[0079] (2) Water contact angle of the laminated nonwoven fabric The following measurements were carried out using a contact angle meter "DMo-501" manufactured by Kyowa Interface Science Co., Ltd.

[0080] In the laminated nonwoven fabric layer of the present invention, the surface on which the nonwoven fabric layer (B) is laminated on the outermost surface is defined as the first surface, and the opposite surface is defined as the second surface, and measurements and calculations were carried out using the following methods. (2.1) The laminated nonwoven fabric was left in a room at a room temperature of 20°C and a relative humidity of 65% for 24 hours. (2.2) The laminated nonwoven fabric that had been subjected to the above treatment was set on the stage of a contact angle meter installed in the same room so that the nonwoven fabric layer (B) served as the measurement surface. (2.3) A 2 μL droplet of ion-exchanged water was prepared on the tip of a needle and applied to the nonwoven fabric. (2.4) The contact angle with the droplet was determined from the image taken 2 seconds after the droplet landed on the nonwoven fabric. If all the water was absorbed by the nonwoven fabric within 2 seconds, the interface between the droplet and the air was determined to be on the same plane as the surface of the nonwoven fabric layer, and the contact angle with water was defined as 0°. (2.5) For each test, the measurement position was changed and measurements were taken five times, and the arithmetic mean value was taken as the contact angle between the first surface and water. (2.6) The laminated nonwoven fabric that had been treated in the same manner as in (2.1) was set so that the nonwoven fabric layer (B) faced the back side, and the above operations (2.2) to (2.5) were repeated, and the arithmetic mean value was taken as the contact angle between the second surface and water.

[0081] (3) Breaking strength ratio (σ max / σ min ) Measurements were carried out as follows using a tensile testing machine "Tensilon UCT100" manufactured by Orientec Co., Ltd.

[0082] The breaking strength ratio of the laminated nonwoven fabric of the present invention was measured and calculated by the following method based on "6.3 Tensile strength and elongation (ISO method)" of JIS L1913:2010 "General nonwoven fabric testing methods." (3.1) One arbitrary direction of the laminated nonwoven fabric was set to 0°, and a test piece measuring 300 mm in length and 25 mm in width was cut out so that the longitudinal direction coincided with the above direction, and three test pieces were taken from different locations. (3.2) The test specimen was set in the tensile testing machine with a gripping distance of 200 mm. (3.3) A tensile test was carried out at a tensile speed of 100 m / min. The strength at break [N] was determined for three specimens taken, and the arithmetic mean value was taken as the breaking strength σ. (3.4) A test piece measuring 300 mm in length and 25 mm in width was cut out so that the longitudinal direction coincided with the axis direction, rotated 22.5° clockwise within the plane of the laminated nonwoven fabric relative to an arbitrary direction set at 0°, and three test pieces were taken from different locations. Then, the operations (3.2) to (3.3) above were repeated to calculate the breaking strength σ. (3.5) The above operation (3.4) was repeated until the in-plane rotation angle of the laminated nonwoven fabric reached 180°, and the breaking strength σ at each angle was calculated. (3.6) The minimum breaking strength σ among the breaking strengths σ calculated by the above method min Maximum breaking strength σ max The ratio (σ max / σ min ) was calculated and used as the breaking strength ratio of the laminated nonwoven fabric.

[0083] (4) Water absorption rate The surface on which the nonwoven fabric layer (B) was disposed as the outermost surface was measured as follows.

[0084] Measurements were made based on "7.1.1 Drop Method" of JIS L1907:2010 "Testing Methods for Water Absorbency of Textile Products." A single drop of water was dropped onto the laminated nonwoven fabric, and the time it took for the water to be absorbed and the specular reflection on the surface to disappear was measured. The simple average of the values measured at 10 different points was calculated, and the value, expressed in seconds and rounded to the nearest decimal place, was used as the water absorption rate.

[0085] (5) Quick drying A drop of water was placed on the surface of the nonwoven fabric layer (B) of the laminated nonwoven fabric, and after one minute, healthy adults (15 men and 15 women, a total of 30 people) touched the surface with their hands and evaluated it using the following three-point scale. The average score of the evaluation results for each nonwoven fabric was calculated and used as the feel of the laminated nonwoven fabric. 5: The surface is smooth and doesn't feel wet. 3: No moisture on the surface, but moist 1: The surface is moist and moist.

[0086] [Example 1] (Nonwoven fabric layer (A)) Polypropylene (PP) was melted in an extruder and spun from a rectangular die with 0.4 mm round holes at a single-hole output rate of 0.56 g / min. The spun yarn was cooled and solidified with cold air, then pulled and stretched in a rectangular ejector with compressed air at a pressure of 0.08 MPa, and collected on a moving net to obtain a nonwoven fiber web. The average single fiber diameter of the fibers constituting the resulting nonwoven fabric layer (A) was 15.5 μm.

[0087] (Nonwoven fabric layer (B)) Polypropylene (PP) was melted in an extruder and spun from a rectangular die with 0.4 mm round holes at a single-hole output rate of 1.30 g / min. The spun yarn was cooled and solidified, then pulled and stretched in a rectangular ejector using compressed air at a pressure of 0.10 MPa, and collected on a moving net to obtain a nonwoven fiber web. The average single fiber diameter of the fibers constituting the resulting nonwoven fabric layer (B) was 24.5 μm.

[0088] (Laminated nonwoven fabric) Nonwoven fabric layer (B) was collected directly on top of the nonwoven fabric layer (A) obtained above (the lamination method is indicated as "inline" in Table 1), thereby obtaining a laminated fiber web having a two-layer structure of spunbond nonwoven fabric layer-spunbond nonwoven fabric layer (the lamination structure is indicated as "A / B" in Table 1).

[0089] The laminated fiber web thus obtained was heat-bonded at a line pressure of 300 N / cm and a heat-bonding temperature of 125°C using a metal embossing roll on the upper roll, which had circular convex portions arranged in a staggered pattern at the same pitch in both the MD and CD directions, and a metal flat roll on the lower roll, which had a pair of upper and lower heating mechanisms. 2A non-ionic surfactant was then applied to the non-woven fabric using a kiss roll to impart hydrophilic properties to the non-woven fabric, with the active ingredient being 0.5 wt% relative to the weight of the laminated non-woven fabric.

[0090] The average single fiber diameter ratio (Db / Da), the contact angle of the laminated nonwoven fabric with water, and the breaking strength ratio (σ max / σ min The results are shown in Table 1.

[0091] [Example 2] A laminated nonwoven fabric was obtained in the same manner as in Example 1, except that the single-hole discharge rate in the production method of the nonwoven fabric layer (B) was changed to 0.90 g / min. The average single fiber diameter of the fibers constituting the obtained nonwoven fabric layer (B) was 20.4 μm. The evaluation results of the obtained laminated nonwoven fabric are shown in Table 1.

[0092] [Comparative Example 1] A laminated nonwoven fabric was obtained in the same manner as in Example 1, except that the nonwoven fabric layer (B) was obtained under the same conditions as those for the nonwoven fabric layer (A). The average single fiber diameter of the fibers constituting the obtained nonwoven fabric layer (A) was 24.5 μm. The evaluation results of the obtained laminated nonwoven fabric are shown in Table 1.

[0093] [Example 3] A laminated nonwoven fabric was obtained in the same manner as in Example 1, except that in the production method of the laminated nonwoven fabric, a nonwoven fabric layer (C) obtained by the following method was collected on top of the nonwoven fabric layer (A), and then the nonwoven fabric layer (B) was collected. The evaluation results of the obtained laminated nonwoven fabric are shown in Table 1.

[0094] (Nonwoven fabric layer (C)) Polypropylene (PP) was melted in an extruder and spun from a rectangular die with 0.4 mm round holes at a single-hole output rate of 0.90 g / min. The spun yarn was cooled and solidified, then pulled and stretched in a rectangular ejector using compressed air at a pressure of 0.10 MPa, and collected on a moving net to obtain a nonwoven fiber web. The average single fiber diameter of the fibers constituting the resulting nonwoven fabric layer (B) was 20.4 μm.

[0095] [Example 4] The fibers of nonwoven fabric layer (A) were collected on a conveyor in the same manner as in Example 1, and thermal bonding was performed in the same manner as in Example 1 to obtain nonwoven fabric layer (A). Similarly, the fibers of nonwoven fabric layer (B) were collected on a conveyor in the same manner as in Example 1, and thermal bonding was performed in the same manner as in Example 1 to obtain nonwoven fabric layer (B). The nonwoven fabric layer (A) and nonwoven fabric layer (B) thus obtained were laminated (the lamination method is described as "offline" in Table 1), and thermal bonding was performed in the same manner as in Example 1 to obtain a laminated nonwoven fabric. The evaluation results of the obtained laminated nonwoven fabric are shown in Table 1.

[0096] Comparative Example 2 A laminated nonwoven fabric was obtained in the same manner as in Example 1, except that no hydrophilic treatment was performed in the manufacturing method of the laminated nonwoven fabric. The contact angle with water was large. The evaluation results of the obtained laminated nonwoven fabric are shown in Table 2.

[0097] [Example 5] The polymer used for nonwoven fabric layer (A) and nonwoven fabric layer (B) was polyethylene terephthalate copolymerized with 8 wt% polyethylene glycol (copolymerized PET), and a laminated nonwoven fabric was obtained by the following method. The evaluation results of the obtained laminated nonwoven fabric are shown in Table 2.

[0098] (Nonwoven fabric layer (A)) Except for using copolymerized PET as the polymer, a nonwoven fiber web was obtained in the same manner as in Example 1. The average single fiber diameter of the fibers constituting the obtained nonwoven fabric layer (A) was 12.5 μm.

[0099] (Nonwoven fabric layer (B)) Except for using copolymerized PET as the polymer, a nonwoven fiber web was obtained in the same manner as in Example 1. The average single fiber diameter of the fibers constituting the obtained nonwoven fabric layer (B) was 19.8 μm.

[0100] (Laminated nonwoven fabric) A laminated nonwoven fabric was obtained in the same manner as in Example 1, except that the heat bonding temperature was set to 200° C. and no hydrophilic treatment was applied.

[0101] Comparative Example 3 A laminated nonwoven fabric was obtained in the same manner as in Example 1, except that the nonwoven fabric layer (A) obtained in the same manner as in Example 5 was used as the nonwoven fabric layer (A) and no hydrophilic treatment was applied in the manufacturing process of the laminated nonwoven fabric. The contact angle with water on the first surface was large. The evaluation results of the obtained laminated nonwoven fabric are shown in Table 2.

[0102] [Example 6] A laminated nonwoven fabric was obtained in the same manner as in Example 1, except that the polymer used in the nonwoven fabric layer (A) was polyethylene terephthalate copolymerized with 8 wt% polyethylene glycol (copolymerized PET) and polyamide 6 (PA6), and the nonwoven fabric layer (A) was obtained by the following method. The evaluation results of the obtained laminated nonwoven fabric are shown in Table 2.

[0103] (Nonwoven fabric (A)) Copolymerized PET and Ny6 were melted in an extruder and spun from a 24-segment hollow fiber-splitting composite rectangular spinneret at a single-hole output rate of 0.56 g / min. The spun yarn was cooled and solidified with cold air, then pulled and stretched in a rectangular ejector using compressed air at an ejector pressure of 0.08 MPa, and collected on a moving net to obtain a nonwoven fiber web. The resulting nonwoven fabric layer (A) had a single fiber that was partially split into multiple fibers, and the average single fiber diameter after splitting was 3.1 μm.

[0104] [Table 1]

[0105] [Table 2]

[0106] In Examples 1 to 6, the average single fiber diameter ratio (Da / Db) was large and the contact angles with water on both the front and back surfaces of the laminated nonwoven fabric were small, indicating that the surface on which the nonwoven fabric layer (B) was laminated on the outermost surface had excellent water absorption speed and quick-drying properties.

[0107] On the other hand, in Comparative Example 1, the average single fiber diameter ratio was small, so that moisture did not migrate to the nonwoven fabric layer (A) side within the nonwoven fabric, resulting in poor water absorption and quick-drying properties. In Comparative Examples 2 and 3, hydrophobic fibers were used in part or all of the laminated nonwoven fabric, so the contact angle with water on the first surface increased, resulting in a slower water absorption rate and worsened water absorption and quick-drying properties. [Industrial Applicability]

[0108] The laminated nonwoven fabric of the present invention has sufficient water absorption and quick-drying properties for use as a nonwoven fabric for sanitary materials. By using the laminated nonwoven fabric of the present invention as at least a part of a sanitary material, a sanitary material having excellent water absorption and quick-drying properties can be obtained.

[0109] The laminated nonwoven fabric of the present invention can be used as a part of sanitary materials such as disposable diapers, sanitary napkins, gauze, bandages, masks, gloves, and adhesive bandages.

Claims

1. A laminated nonwoven fabric in which at least one nonwoven fabric layer (A) made of first thermoplastic resin fibers and at least one nonwoven fabric layer (B) made of second thermoplastic resin fibers are laminated, wherein the ratio (Db / Da) of the average single fiber diameter Db of the fibers constituting the nonwoven fabric layer (B) to the average single fiber diameter Da of the fibers constituting the nonwoven fabric layer (A) is 1.1 or more, the nonwoven fabric layer (B) is laminated on at least one outermost surface, and further, the contact angle with water of the front surface of the laminated nonwoven fabric is 10° or less, and the contact angle with water of the back surface of the laminated nonwoven fabric is 10° or less.

2. The laminated nonwoven fabric according to claim 1 , wherein the nonwoven fabric layer (A) is laminated on the outermost surface of the other nonwoven fabric layer.

3. The laminated nonwoven fabric is rotated in the plane of the laminated nonwoven fabric from an arbitrary direction of 0° to 180° in 22.5° increments to measure the breaking strength, and the minimum breaking strength σ ｍｉｎ Maximum breaking strength σ ｍａｘ The ratio of (σ ｍａｘ / σ ｍｉｎ 3. The laminated nonwoven fabric according to claim 1, wherein the modulus of elasticity is 1.2 to 4.

0.

4. 4. The laminated nonwoven fabric according to claim 1, wherein the nonwoven fabric layer (A) and the nonwoven fabric layer (B) are both made of long-fiber nonwoven fabric.

5. A hygienic material, at least a part of which is composed of the laminated nonwoven fabric according to any one of claims 1 to 4.

6. The hygienic material according to claim 5, wherein the outermost surface of the side on which the nonwoven fabric layer (B) is laminated is arranged facing the skin of the wearer.

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