Laminate and method for producing laminate

Abstract

To provide a laminate that achieves a high water absorption capacity and exhibits superior strength when absorbing water, and a method for producing the laminate.SOLUTION: A laminate 10 comprises a first layer 11 and a second layer 12 that is positioned on one surface 11a of the first layer 11 and in contact with the first layer 11, wherein the first layer 11 is a nonwoven fabric having an apparent density of 0.075 g / cm3 or more, the second layer 12 is a nonwoven fabric having an apparent density of 0.120 g / cm3 or less, and the apparent density of the first layer 11 is greater than that of the second layer 12.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a laminate and a method for manufacturing the laminate. [Background technology]

[0002] Towels are washed frequently from the standpoint of hygiene when reused, and washing them can be a hassle. Towels used in beauty salons, nursing homes, etc., are particularly prone to frequent washing. Therefore, disposable towels have been attracting attention as an alternative to towels. Known examples of disposable towels include nonwoven towels. Patent Document 1 discloses a highly water-absorbent cleaning nonwoven fabric made of a three-layer spunlace nonwoven fabric in which a hydrophilic fiber layer, a cheesecloth, and a hydrophilic fiber layer are laminated in this order. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-247063 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the nonwoven fabric described in Patent Document 1 does not have sufficient water absorption capacity. Although water absorption capacity increases if the nonwoven fabric is made thicker, the thicker the fabric, the more difficult it becomes to use as a substitute for towels. Furthermore, when used as a replacement for towels or for cleaning, it is required to be strong enough to not tear even when it absorbs water.

[0005] An object of the present invention is to provide a laminate that has a high water absorption capacity and is also excellent in strength when water is absorbed, and a method for producing the laminate. [Means for solving the problem]

[0006] The present invention has the following aspects. [1] A laminate comprising a first layer and a second layer located on one surface of the first layer and in contact with the first layer, The first layer has an apparent specific gravity of 0.075 g / cm 3 The nonwoven fabric is as described above. The second layer has an apparent specific gravity of 0.120 g / cm 3 A nonwoven fabric that is: A laminate, wherein the apparent specific gravity of the first layer is greater than the apparent specific gravity of the second layer. [2] The laminate according to [1] above, wherein the second layer is an air-laid nonwoven fabric. [3] the first layer and the second layer are bonded together; The laminate according to [1] or [2] above, wherein a plurality of slit-shaped through holes penetrating the first layer and the second layer are provided in a staggered pattern. [4] A method for producing a laminate according to any one of [1] to [3], Apparent specific gravity is 0.075g / cm 3 and nonwoven fabric a having an apparent specific gravity of 0.130 g / cm 3 a joining step of joining the nonwoven fabric b to the nonwoven fabric b, The nonwoven fabric a is the first layer, The method for producing a laminate, wherein the nonwoven fabric b is the second layer. [5] The method for producing a laminate according to [4], wherein the joining step is a step of providing a plurality of slit-shaped through holes penetrating the first layer and the second layer in a staggered pattern. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a laminate having a high water absorption capacity and excellent strength when water is absorbed, and a method for producing the laminate. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a plan view schematically illustrating an example of a laminate of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the laminate shown in FIG. 1 taken along line AA'. [Figure 3]2 is a plan view showing a state in which the laminate shown in FIG. 1 is stretched in the X direction. [Figure 4] FIG. 1 is a schematic diagram showing an example of a manufacturing apparatus used in a method for manufacturing a laminate; FIG. 2 is a side view showing the configuration; DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the laminate and the method for producing the laminate according to the present invention will be described in detail below with reference to FIGS. 1 to 4 as appropriate. In this specification, a numerical range expressed as "to" means a numerical range that includes the numbers before and after "to" as the lower and upper limits. For example, A to B is equivalent to A or more and B or less. In addition, in the present invention, "high water absorption capacity" means that in addition to the laminate absorbing a large amount of water when immersed in water, the laminate also has excellent water absorption capacity in the planar direction when it comes into contact with water (hereinafter also referred to as "water absorption and diffusibility") and excellent water absorption capacity in the thickness direction (stacking direction) of the laminate (hereinafter also referred to as "spot water absorption capacity"). Furthermore, in the drawings used in the following description, characteristic portions may be enlarged for convenience in order to make the features easier to understand, and the dimensional ratios of each component may differ from the actual ones. The materials, dimensions, etc. exemplified in the following description are merely examples, and the present invention is not limited to them and can be implemented with appropriate changes within the scope of the present invention. 2 to 4, the same components as those in FIG. 1 are denoted by the same reference numerals, and the description thereof will be omitted.

[0010] [Laminate] 1 to 3 show an example of the laminate of the present invention. The laminate 10 of this embodiment includes a first layer 11 and a second layer 12 located on one surface 11a of the first layer 11 and in contact with the first layer 11. The first layer 11 and the second layer 12 are bonded to each other. The laminate 10 also has a plurality of through holes 13 .

[0011] <First Layer> The first layer 11 has an apparent specific gravity of 0.075 g / cm 3 This is the nonwoven fabric (hereinafter also referred to as "nonwoven fabric A"). The apparent specific gravity of nonwoven fabric A is 0.075 g / cm 3 or more, 0.100 g / cm 3 More than 0.120 g / cm is preferable. 3 More preferably, 1.000 g / cm 3 Preferably less than 0.800 g / cm 3 Less than 0.500 g / cm is more preferable. 3 The following is even more preferable. If the apparent specific gravity of nonwoven fabric A is equal to or greater than the above-mentioned lower limit, the water absorption and diffusion properties of laminate 10 are improved. In addition, the strength of laminate 10 can be well maintained when absorbing water. If the apparent specific gravity of nonwoven fabric A is equal to or less than the above-mentioned upper limit, the rigidity is reduced, and therefore, when laminate 10 is used as a towel substitute, for example, good workability can be achieved. The above upper and lower limits can be combined arbitrarily. For example, the apparent specific gravity of nonwoven fabric A is 0.075 g / cm 3 or more, 0.075 to 1.000 g / cm 3 is preferable, and 0.100 to 0.800 g / cm 3 More preferably, 0.120 to 0.500 g / cm 3 is more preferable.

[0012] The apparent specific gravity of the first layer 11, i.e., the apparent specific gravity of nonwoven fabric A, is greater than the apparent specific gravity of the second layer described below, i.e., the apparent specific gravity of nonwoven fabric B described below. The difference between the apparent specific gravity of nonwoven fabric A and the apparent specific gravity of nonwoven fabric B (apparent specific gravity of nonwoven fabric A - apparent specific gravity of nonwoven fabric B) is 0.005 g / cm 3 More than 0.010 to 0.300 g / cm 3 More preferably, 0.040 to 0.200 g / cm 3 When the apparent specific gravity of nonwoven fabric A is greater than the apparent specific gravity of nonwoven fabric B, the laminate 10 has an excellent balance between water absorption and diffusion properties and spot water absorption properties, and the water absorption properties of the laminate 10 are enhanced.

[0013] In the present invention, the apparent specific gravity of a nonwoven fabric is the specific gravity obtained by dividing the basis weight of the nonwoven fabric by the thickness of the nonwoven fabric, and is also called the apparent density. 1 to 3, when the laminate 10 has a plurality of through holes 13, it can also be said that the nonwoven fabric A and the nonwoven fabric B described below have a plurality of through holes 13. When the nonwoven fabric A and the nonwoven fabric B have a plurality of through holes, the apparent specific gravity of the nonwoven fabric A and the nonwoven fabric B is the value when the through holes are formed in the nonwoven fabric.

[0014] The thickness of nonwoven fabric A is preferably 0.03 to 1.5 mm, more preferably 0.08 to 1.00 mm, and even more preferably 0.12 to 0.5 mm. When the thickness of nonwoven fabric A is equal to or less than the upper limit, the overall thickness of laminate 10 is less likely to be large, and laminate 10 has an excellent feel when used as a towel substitute, for example. The thickness of the nonwoven fabric A is the average value of the thicknesses of the first layer 11 measured from the image of the cross section of the laminate 10 observed under a microscope at any three points on the laminate 10. When nonwoven fabric A and nonwoven fabric B have a plurality of through-holes, the thicknesses of nonwoven fabric A and nonwoven fabric B are the values ​​when the through-holes are formed in the nonwoven fabric. When nonwoven fabric A is embossed, the thickness of the first layer 11 in the portion in contact with the second layer 12 is measured.

[0015] The basis weight of nonwoven fabric A is 10 to 250 g / m 2 is preferable, and 20 to 200 g / m 2 More preferably, 30 to 150 g / m 2 is more preferable. If the basis weight of nonwoven fabric A is equal to or greater than the lower limit, sufficient strength can be maintained. If the basis weight of nonwoven fabric A is equal to or less than the upper limit, rigidity decreases, and therefore, when laminate 10 is used as a towel substitute, for example, good workability can be obtained. The basis weight of nonwoven fabric A is a value measured in accordance with JIS P 8124:2011 after peeling off first layer 11 from laminate 10, or a value obtained by subtracting the basis weight of nonwoven fabric B from the basis weight of laminate 10. The basis weight of laminate 10 is a value measured in accordance with JIS P 8124:2011. The basis weight of nonwoven fabric A is the same as that of nonwoven fabric a described later, and the basis weight does not change depending on whether or not there are through holes.

[0016] The water absorption capacity of nonwoven fabric A is 100 g / m 2 More than 200g / m 2 More preferably, 300 g / m 2 The above is more preferable. There is no particular upper limit to the water absorption capacity of nonwoven fabric A. The water absorption capacity of nonwoven fabric A is measured as follows: First layer 11 is peeled from laminate 10, the peeled first layer 11 is cut into 10 cm square pieces, the mass is measured, the pieces are placed in a 50-mesh basket, immersed in a container containing distilled water for 5 minutes, and then removed and the mass is measured one minute later. The mass of the basket and the mass of first layer 11 before immersion are subtracted from the result, and the resulting value is converted to square meter and used as the water absorption capacity of nonwoven fabric A. When nonwoven fabric A and nonwoven fabric B have a plurality of through-holes, the water absorption amounts of nonwoven fabric A and nonwoven fabric B are values ​​when the through-holes are formed in the nonwoven fabric.

[0017] The fibers constituting nonwoven fabric A (hereinafter also referred to as "raw fiber A") can be appropriately selected from fibers known as raw fiber for nonwoven fabrics, and are not particularly limited, but hydrophilic fibers are preferred from the viewpoint of further improving water absorbency. As the hydrophilic fiber, a cellulosic fiber is preferred in terms of handling during production, strength, cost, and environmental friendliness. Examples of cellulosic fibers include wood pulp made from softwood or hardwood; mercerized pulp or crosslinked pulp obtained by chemically treating wood pulp; non-wood pulp such as bagasse, kenaf, bamboo, hemp, and cotton (cotton linters, etc.); regenerated cellulose such as rayon and fibril rayon; and semi-synthetic cellulose such as acetate and triacetate. Examples of wood pulp include mechanical pulp such as groundwood pulp, refiner ground pulp, thermomechanical pulp, and chemithermomechanical pulp; chemical pulp such as kraft pulp, sulfide pulp, and alkaline pulp; and semi-chemical pulp. Among these, softwood bleached kraft pulp (NBKP) and hardwood bleached kraft pulp (LBKP) are preferred in terms of strength and ease of handling during production. These cellulosic fibers may be used alone or in combination of two or more.

[0018] The nonwoven fabric A may contain, as raw material fibers A, fibers other than hydrophilic fibers. Examples of other fibers include natural fibers other than hydrophilic fibers, fibers made of synthetic resins, and the like. Examples of natural fibers other than hydrophilic fibers include animal fibers such as wool (e.g., sheep's wool) and silk; and mineral fibers. Examples of fibers made of synthetic resin include fibers made of polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT), nylon (registered trademark), polyethylene (PE), polypropylene (PP), and polylactic acid (PLA). These other fibers may be used singly or in combination of two or more.

[0019] The average fiber diameter of raw fiber A is preferably 5 to 100 μm, more preferably 10 to 50 μm. When the average fiber diameter of raw fiber A is equal to or greater than the lower limit, the laminate 10 can be given a strength suitable for use as a disposable towel. When the average fiber diameter of raw fiber A is equal to or less than the upper limit, a surface that feels good against the skin can be obtained. The average fiber diameter of raw material fiber A is a value calculated by measuring the fiber diameters of 100 fibers by microscopic observation and averaging the diameters of the 100 fibers.

[0020] The raw material fibers A may be short fibers having an average fiber length of 3 to 80 mm, or continuous fibers obtained by extruding a resin from a mold nozzle. When the average fiber length of the raw material fibers A is equal to or greater than the lower limit, the laminate 10 can be given a strength sufficient for a disposable towel. The average fiber length of raw material fiber A is a value calculated by measuring the fiber lengths of 100 fibers by microscopic observation and averaging the lengths of the 100 fibers.

[0021] Examples of nonwoven fabric A include dry nonwoven fabrics such as airlaid nonwoven fabrics, spunlace nonwoven fabrics, needle-punched nonwoven fabrics, resin-bonded nonwoven fabrics, and thermal-bonded nonwoven fabrics; melt-spun nonwoven fabrics such as spunbonded nonwoven fabrics and melt-blown nonwoven fabrics; and wetlaid nonwoven fabrics. Among these, airlaid nonwoven fabrics (e.g., pulp airlaid nonwoven fabrics), spunlace nonwoven fabrics (e.g., cotton spunlace nonwoven fabrics, rayon spunlace nonwoven fabrics), and wetlaid nonwoven fabrics are preferred from the viewpoint of excellent water absorbency.

[0022] Air-laid nonwoven fabric is a nonwoven fabric in which a web is formed using the air-laid method, which uses airflow to randomly layer the fibers that make up the nonwoven fabric in three dimensions. Airlaid nonwoven fabrics are manufactured, for example, as follows. First, an air-permeable carrier sheet is placed directly on a mesh-like endless belt or on an endless belt. Then, raw material fibers are deposited on the air-permeable carrier sheet using an airlaid web-forming device to form a web. The raw material fibers contained in the web are then bonded to obtain an airlaid nonwoven fabric. Examples of methods for bonding the raw material fibers include chemical bonding, thermal bonding, and a multi-bond method that combines chemical and thermal bonding. The chemical bonding method involves spraying a binder onto the web and drying it with hot air or the like to bond the fibers together. The thermal bonding method involves supplying heat-fusible resin particles or heat-fusible fibers together with the raw material fibers and then heat-treating them with hot air or the like to thermally bond them. That is, in addition to the raw fiber A, the nonwoven fabric A may contain one or more of a binder, a heat-fusible resin, and a heat-fusible fiber, as required.

[0023] The binder is preferably an aqueous binder. Examples of aqueous binders include aqueous solution type binders such as casein, sodium alginate, hydroxyethyl cellulose, sodium carboxymethyl cellulose, polyvinyl alcohol (PVA), and sodium polyacrylate; and emulsion type binders such as polyacrylic esters, acrylic ester-styrene copolymers, polyvinyl acetate, ethylene-vinyl acetate copolymers (EVA), acrylonitrile-butadiene copolymers, methyl methacrylate-butadiene copolymers, and styrene-butadiene copolymer latex (SBR).

[0024] The heat-fusible resin is preferably a thermoplastic resin having thermal adhesive properties. Examples of thermoplastic resins include polyester resin, acrylic resin, polyolefin resin (polyethylene, polypropylene, etc.), styrene-acrylic resin, ethylene-vinyl acetate resin, urethane resin, polyamide resin, polycarbonate resin, and polylactic acid resin.

[0025] The heat-fusible fiber is a fibrous heat-fusible resin. The thermally adhesive fiber may be a single yarn or a multifilament, and may be obtained by combining two types of resins with different melting points, and may have a core-sheath structure or a side-by-side structure in which the fiber is partially melted. As the core-sheath structure fiber, a fiber having a structure in which a sheath made of a resin with a low melting point is formed on the outer periphery of a core made of a resin with a high melting point is preferred, and examples thereof include the following. Polypropylene / polyethylene core-sheath fiber, which has polypropylene in the core and polyethylene in the sheath. Polyester / polyethylene core-sheath fiber, which has a polyester core and a polyethylene sheath. Polyester / polypropylene sheath-core fiber, which has polyester in the core and polypropylene in the sheath. Polyethylene / low-melting-point polyethylene core-sheath fiber, which has a polyethylene core and a low-melting-point polyethylene sheath with a lower melting point than the core. Polypropylene / low-melting point polypropylene core-sheath fiber, which has a polypropylene core and a low-melting point propylene sheath with a lower melting point than the core. Polyester / low melting point polyester sheath-core fiber, which has a polyester core and a low melting point polyester sheath with a lower melting point than the core.

[0026] Spunlace nonwoven fabric is a nonwoven fabric made by forming a web from opened raw fibers using a carding machine or air randomizer, and then entangling the fibers of the web three-dimensionally using a high-pressure water jet by a hydroentangling method.

[0027] A wet-laid nonwoven fabric is a nonwoven fabric in which raw fiber is dispersed in water, a slurry of which is made into a net by a wet papermaking method to form a web, and the raw fiber contained in the web is bonded. Methods for bonding raw material fibers include the above-mentioned chemical bonding method, thermal bonding method, a multi-bonding method that combines chemical bonding and thermal bonding methods, hydroentanglement method, needle punching method, a method using hydrogen bonding of pulp, etc. The needle punching method is a method in which needles are pierced into the web to mechanically entangle the raw material fibers of the web. In the present invention, the wetlaid nonwoven fabric also includes papers such as tissue paper, kraft paper, crepe paper, and synthetic paper, in which fibers are bonded together by at least one of a binder and hydrogen bonding.

[0028] The first layer 11 may have a single layer structure or a multi-layer structure (composite layer structure). That is, the first layer 11 may be made of one layer of nonwoven fabric A, or may be made of two or more layers of nonwoven fabric A. However, it is preferable that the first layer 11 be made of one layer of nonwoven fabric A, because this prevents the overall thickness of the laminate 10 from becoming too thick and provides an excellent feel when the laminate 10 is used as a towel substitute, for example.

[0029] <Second Layer> The second layer 12 is located on one surface 11a of the first layer 11 and is a layer in contact with the first layer 11. In other words, the second layer 12 is stacked adjacent to one surface 11a of the first layer 11. The second layer 12 has an apparent specific gravity of 0.120 g / cm 3 The nonwoven fabric is as follows (hereinafter also referred to as "nonwoven fabric B"). The apparent specific gravity of nonwoven fabric B is 0.120 g / cm 3 is less than or equal to 0.100 g / cm 3 Preferably less than 0.080 g / cm 3 More preferably, 0.030 g / cm or less 3 More than 0.045 g / cm is preferable. 3 More preferably, 0.060 g / cm or more 3The above is even more preferable. If the apparent specific gravity of nonwoven fabric B is equal to or greater than the above lower limit, nonwoven fabric B can sufficiently retain water after absorbing it. If the apparent specific gravity of nonwoven fabric B is equal to or less than the above upper limit, the water absorbency (spot water absorbency) in the thickness direction (stacking direction) of laminate 10 is improved, and water can be absorbed in spots. The above upper and lower limits can be combined arbitrarily. For example, the apparent specific gravity of nonwoven fabric B is 0.120 g / cm 3 or less, 0.030 to 0.120 g / cm 3 is preferable, and 0.045 to 0.100 g / cm 3 More preferably, 0.060 to 0.080 g / cm 3 is more preferable.

[0030] The thickness of nonwoven fabric B is preferably 0.5 to 2.5 mm, more preferably 0.6 to 2.0 mm, and even more preferably 0.7 to 1.5 mm. If the thickness of nonwoven fabric B is equal to or greater than the lower limit, a sufficient amount of water absorption can be achieved. If the thickness of nonwoven fabric B is equal to or less than the upper limit, the overall thickness of laminate 10 is less likely to be large, and laminate 10 will have an excellent feel when used as, for example, a towel substitute. The thickness of nonwoven fabric B is the average value of the thicknesses of second layer 12 measured from the images of the cross section of laminate 10 observed under a microscope at any three points on laminate 10. When the nonwoven fabric A is embossed, the thickness of the first layer 11 in the portion in contact with the second layer 12 is measured.

[0031] The basis weight of nonwoven fabric B is 30 to 200 g / m 2 is preferable, and 40 to 160 g / m 2 More preferably, 50 to 120 g / m 2 is more preferable. When the basis weight of nonwoven fabric B is equal to or greater than the lower limit, good spot water absorbency can be obtained. When the basis weight of nonwoven fabric B is equal to or less than the upper limit, the adhesion between the fibers constituting nonwoven fabric B can be maintained, and the breaking strength can be increased. The basis weight of nonwoven fabric B is the value measured in accordance with JIS P 8124:2011 after peeling off second layer 12 from laminate 10, or the value obtained by subtracting the basis weight of nonwoven fabric A from the basis weight of laminate 10. The basis weight of nonwoven fabric B is the same as that of nonwoven fabric b described below, and the basis weight does not change depending on whether or not there are through holes.

[0032] The water absorption capacity of nonwoven fabric B is 600 g / m 2 More than 800g / m 2 More preferably, 1000g / m 2 The above is more preferable. There is no particular upper limit to the water absorption capacity of nonwoven fabric B. The water absorption capacity of nonwoven fabric B is measured as follows: Namely, second layer 12 is peeled from laminate 10, the peeled second layer 12 is cut into 10 cm square pieces, the mass is measured, the pieces are placed in a 50-mesh basket, immersed in a container containing distilled water for 5 minutes, and then removed and the mass is measured one minute later. The mass of the basket and the second layer 12 before immersion are subtracted from the result, and the resulting value is converted to square meter and used as the water absorption capacity of nonwoven fabric B.

[0033] The fibers constituting nonwoven fabric B (hereinafter also referred to as "raw fiber B") can be appropriately selected from fibers known as raw fiber for nonwoven fabrics and are not particularly limited, but hydrophilic fibers are preferred from the viewpoint of further improving water absorption. Examples of hydrophilic fibers include the hydrophilic fibers exemplified above in the description of first layer 11. The nonwoven fabric B may contain fibers other than hydrophilic fibers as raw fiber B. Examples of the other fibers include the other fibers exemplified above in the description of the first layer 11.

[0034] The average fiber diameter of raw fiber B is preferably 10 to 60 μm, more preferably 20 to 40 μm. If the average fiber diameter of raw fiber B is equal to or greater than the lower limit, when nonwoven fabric B is made into, for example, an airlaid nonwoven fabric, the fibers are less likely to form clumps, i.e., neps are less likely to occur, and a homogeneous laminate 10 can be obtained. If the average fiber diameter of raw fiber B is equal to or less than the upper limit, nonwoven fabric B can be maintained at an appropriate softness, and when laminate 10 is used as, for example, a towel substitute, the laminate 10 feels soft when touched. The average fiber diameter of raw material fibers B is a value calculated in the same manner as the average fiber diameter of raw material fibers A.

[0035] The average fiber length of raw fiber B is preferably 1 to 100 mm, more preferably 3 to 60 mm. In particular, when nonwoven fabric B is an airlaid nonwoven fabric, the average fiber length of raw fiber B constituting nonwoven fabric B is preferably 1 to 10 mm, more preferably 3 to 6 mm. When the average fiber length of raw fiber B is equal to or greater than the lower limit, the fibers are appropriately entangled with each other, providing sufficient strength to nonwoven fabric B. When the average fiber length of raw fiber B is equal to or less than the upper limit, excessive entanglement of the fibers with each other can be suppressed. As a result, the fibers are less likely to form clumps, and nonwoven fabric B can be prevented from becoming uneven. The average fiber length of raw material fibers B is a value calculated in the same manner as the average fiber length of raw material fibers A.

[0036] Examples of nonwoven fabric B include dry nonwoven fabrics such as airlaid nonwoven fabrics, spunlace nonwoven fabrics, needle-punched nonwoven fabrics, resin-bonded nonwoven fabrics, and thermal-bonded nonwoven fabrics; melt-spun nonwoven fabrics such as spunbonded nonwoven fabrics and melt-blown nonwoven fabrics; and wetlaid nonwoven fabrics. Among these, airlaid nonwoven fabrics (e.g., pulp airlaid nonwoven fabrics), spunlace nonwoven fabrics (e.g., cotton spunlace nonwoven fabrics and rayon spunlace nonwoven fabrics), and wetlaid nonwoven fabrics are preferred from the viewpoint of excellent water absorbency, and among these, airlaid nonwoven fabrics are particularly preferred from the viewpoint of facilitating bonding of the first layer 11 and the second layer 12 when through-holes 13, which will be described later, are formed. Examples of the air-laid nonwoven fabric, the spunlace nonwoven fabric, and the wet-laid nonwoven fabric include the nonwoven fabrics exemplified above in the description of the first layer 11. Nonwoven fabric B may contain, as needed, one or more of a binder, a heat-fusible resin, and a heat-fusible fiber in addition to raw fiber B. Examples of these binders, heat-fusible resins, and heat-fusible fibers include the binders, heat-fusible resins, and heat-fusible fibers exemplified above in the description of first layer 11.

[0037] The second layer 12 may have a single layer structure or a multi-layer structure (composite layer structure). That is, the second layer 12 may be made of one layer of nonwoven fabric B, or may be made of two or more layers of nonwoven fabric B. However, it is preferable that the second layer 12 be made of one layer of nonwoven fabric B, because this prevents the overall thickness of the laminate 10 from becoming too thick and provides an excellent feel when the laminate 10 is used as a towel substitute, for example.

[0038] An example of a combination of nonwoven fabric A and nonwoven fabric B is shown below. A combination in which nonwoven fabric A is a wet-laid nonwoven fabric and nonwoven fabric B is an air-laid nonwoven fabric. A combination in which nonwoven fabric A is a spunlace nonwoven fabric and nonwoven fabric B is an airlaid nonwoven fabric. A combination in which nonwoven fabric A is an airlaid nonwoven fabric and nonwoven fabric B is an airlaid nonwoven fabric. A combination in which nonwoven fabric A is a spunlace nonwoven fabric and nonwoven fabric B is a spunlace nonwoven fabric. A combination in which nonwoven fabric A is a wet-laid nonwoven fabric and nonwoven fabric B is a spunlace nonwoven fabric.

[0039] <Through hole> The through-holes 13 are slit-like cuts that penetrate the first layer 11 and the second layer 12. In other words, it can be said that the nonwoven fabrics A and B have through-holes 13. As shown in FIG. 1, in a plan view, when the direction parallel to a pair of sides of the laminate 10 is the X direction and the direction perpendicular to the X direction is the Y direction, the through holes 13 are arranged in a staggered pattern with the longitudinal direction of the through holes 13 being the Y direction. Here, the staggered arrangement refers to an arrangement in which a plurality of rows of through holes 13, each row of which has a plurality of through holes 13 arranged at equal intervals in the Y direction, are arranged at equal intervals in the X direction, and in two rows adjacent to each other in the X direction, the nearest through holes 13 are offset from each other. It is preferable that the through holes 13 are offset by half a pitch from each other.

[0040] When the second layer 12 is an air-laid nonwoven fabric, the formation of the through holes 13 makes it easier to bond the first layer 11 and the second layer 12 together, even without using an adhesive. Furthermore, since the laminate 10 has the through holes 13, when the laminate 10 is stretched in the X direction, the through holes 13 are expanded into a diamond or tortoiseshell shape as shown in Fig. 3, forming a mesh-like laminate 10. This mesh-like laminate 10 is also called an expanded metal-like laminate. The surface area of ​​the laminate 10 increases due to its mesh structure, allowing it to absorb moisture from a wide range of areas at once.

[0041] The length L of the through-hole 13 is preferably 4 to 30 mm, more preferably 6 to 20 mm, and even more preferably 8 to 15 mm. If the length L is equal to or greater than the lower limit, good strength can be obtained when the through-hole 13 (hereinafter also referred to as "slit portion") is widened. If the length L is equal to or less than the upper limit, good openability can be obtained when the slit portion is widened. The length L is a value measured by a vernier caliper.

[0042] In a row of through holes 13 in which a plurality of through holes 13 are arranged at equal intervals in the Y direction, the distance D between adjacent through holes 13 (i.e., the length of the area where no through holes 13 are formed) is preferably 0.5 to 20 mm, more preferably 1 to 10 mm, and even more preferably 1.5 to 5 mm. If the distance D is equal to or greater than the lower limit, the slit portion is less likely to tear when widened. If the distance D is equal to or less than the upper limit, the slit portion is more likely to become uneven when widened, and the unevenness increases the contact area, resulting in good water absorbency. The distance D is a value measured by a vernier caliper.

[0043] The width W of a row of adjacent through holes 13 in the X direction is preferably 0.5 to 20 mm, more preferably 1 to 10 mm, and even more preferably 1.5 to 5 mm. If the width W is equal to or greater than the lower limit, the slit portions are less likely to tear when widened. If the width W is equal to or less than the upper limit, the slit portions are more likely to become uneven when widened, and the unevenness increases the contact area, resulting in good water absorbency. The width W is a value measured by a vernier caliper.

[0044] <Thickness of laminate> The thickness of the laminate 10 is preferably 0.5 to 4 mm, more preferably 0.6 to 3 mm, and even more preferably 0.7 to 2.5 mm. When the thickness of the laminate 10 is equal to or greater than the lower limit, good water absorbency can be obtained. When the thickness of the laminate 10 is equal to or less than the upper limit, the laminate 10 provides an excellent feel when used, for example, as a towel substitute. The thickness of the laminate 10 is an average value of thicknesses of the laminate 10 measured from an image of a cross section of the laminate 10 observed under a microscope at any three points on the laminate 10.

[0045] The basis weight of the laminate 10 is 40 to 450 g / m 2 is preferable, and 60 to 360 g / m 2 More preferably, 80 to 270 g / m 2 is even more preferable. When the basis weight of the laminate 10 is equal to or greater than the lower limit, the balance between water absorbency and strength is excellent. When the basis weight of the laminate 10 is equal to or less than the upper limit, strength is maintained and good workability is obtained when the laminate 10 is used as a towel substitute, for example. The basis weight of the laminate 10 is the sum of the basis weight of the nonwoven fabric A and the basis weight of the nonwoven fabric B.

[0046] <Method of manufacturing laminate> The method for producing the laminate 10 of this embodiment is to use a laminate having an apparent specific gravity of 0.075 g / cm 3 and nonwoven fabric a having an apparent specific gravity of 0.130 g / cm 3The method includes a step (hereinafter also referred to as the "joining step") of joining nonwoven fabric a to nonwoven fabric b, which is described below, to form nonwoven fabric a into a first layer 11 (i.e., nonwoven fabric A) and nonwoven fabric b into a second layer 12 (i.e., nonwoven fabric B), and the joining step is a step of providing a plurality of slit-shaped through holes 13 in a staggered pattern that penetrates the first layer 11 and the second layer 12. The laminate 10 can be manufactured by this method using, for example, a manufacturing apparatus 20 shown in FIG.

[0047] (manufacturing equipment) The laminate manufacturing apparatus 20 shown in FIG. 4 includes, in order from the downstream side, a laminating means 21, a slitting means 22, and a cutting means 23. The laminating means 21 and the slit processing means 22 are collectively referred to as a joining mechanism.

[0048] The laminating means 21 is a means for laminating a nonwoven fabric a that will become a first layer and a nonwoven fabric b that will become a second layer to obtain an intermediate body 14 . The lamination means 21 includes a first delivery roll 211 that delivers a long nonwoven fabric a wound in a roll, a second delivery roll 212 that delivers a long nonwoven fabric b that is also wound in a roll, and a plurality of guide rolls 213.

[0049] The first delivery roll 211 has a nonwoven fabric a wound thereon. The second delivery roll 212 has a nonwoven fabric b wound around it. In addition, the first feed roll 211 and the second feed roll 212 are each connected to a drive device such as a motor (not shown) so as to be driven to rotate, thereby enabling the nonwoven fabric a wound around the first feed roll 211 and the nonwoven fabric b wound around the second feed roll 212 to be unwound (released) at a predetermined speed.

[0050] The guide rolls 213 are arranged between the first delivery roll 211 or the second delivery roll 212 and the slit processing means 22, i.e., on the transport route of the nonwoven fabrics a and b to the slit processing means 22, and multiple guide rolls 213 are arranged so that the nonwoven fabrics a and b are transported without slackening. In this embodiment, four guide rolls 213 are arranged, and nonwoven fabric b is laminated on nonwoven fabric a at the third guide roll 213 from the downstream side, thereby obtaining an intermediate 14. These guide rolls 213 are configured to be rotatable, and are rotated by the running of nonwoven fabric a and nonwoven fabric b. The guide roll 213 may be configured to be connected to a driving device such as a motor and rotated as needed.

[0051] The slitting means 22 is a means for slitting the intermediate body 14 to form through-holes that penetrate the nonwoven fabrics a and b. The slit processing means 22 includes a slit roll 221 having a slit blade (not shown) on the circumferential surface, and a nip roll 222 disposed opposite the slit roll 221 and nipping the intermediate body 14 together with the slit roll 221.

[0052] The slit roll 221 has a plurality of slit blades (not shown) on its outer circumferential surface. The multiple slit blades are arranged in a staggered pattern on the outer surface of the slit roll 221 so that the through holes in the intermediate body 14 are arranged in a staggered pattern with the longitudinal direction of the through holes parallel to the conveying direction of the intermediate body 14. The slit roll 221 is connected to a driving device (not shown) such as a motor to rotate it.

[0053] The nip roll 222 is a roll with a flat surface. The nip roll 222 rotates in synchronization with the slit roll 221 while being pressed against the slit roll 221 with a predetermined pressing force via the intermediate body 14 . The nip roll 222 may be connected to a driving device (not shown) such as a motor so that the nip roll 222 rotates in synchronization with the slit roll 221.

[0054] The cutting means 23 is a means for cutting the strip-shaped laminate 10 provided with through holes into a desired size to obtain laminate 10 sheets. The cutting means 23 includes a cutter 231 . The cutting machine 231 is not particularly limited as long as it can cut the laminate 10, and examples thereof include a cutting machine.

[0055] (Nonwoven fabric a) The nonwoven fabric a becomes the first layer 11 that constitutes the laminate 10, that is, the nonwoven fabric A, through a bonding process. The apparent specific gravity of nonwoven fabric a is 0.075 g / cm 3 or more, 0.100 g / cm 3 More than 0.120 g / cm is preferable. 3 More preferably, 1.000 g / cm 3 Preferably less than 0.800 g / cm 3 Less than 0.500 g / cm is more preferable. 3 The following is even more preferable. If the apparent specific gravity of nonwoven fabric a is equal to or greater than the above-mentioned lower limit, a laminate 10 having excellent water absorption and diffusion properties and strength can be obtained. If the apparent specific gravity of nonwoven fabric a is equal to or less than the above-mentioned upper limit, a laminate 10 having reduced rigidity can be obtained, and therefore, when the laminate 10 is used as a substitute for a towel, for example, good workability can be obtained. The above upper and lower limits can be combined arbitrarily. For example, the apparent specific gravity of nonwoven fabric a is 0.075 g / cm 3 or more, 0.075 to 1.000 g / cm 3 is preferable, and 0.100 to 0.800 g / cm 3 More preferably, 0.120 to 0.500 g / cm 3 is more preferable.

[0056] The apparent specific gravity of nonwoven fabric a is preferably greater than the apparent specific gravity of nonwoven fabric b, which will be described later. The difference between the apparent specific gravity of nonwoven fabric a and the apparent specific gravity of nonwoven fabric b (apparent specific gravity of nonwoven fabric a - apparent specific gravity of nonwoven fabric b) is 0.010 g / cm 3 More than 0.020 to 0.300 g / cm 3 More preferably, 0.050 to 0.200 g / cm 3 When the apparent specific gravity of nonwoven fabric a is greater than the apparent specific gravity of nonwoven fabric b, the laminate 10 has an excellent balance between water absorption and diffusion properties and spot water absorption properties.

[0057] The thickness of the nonwoven fabric a is preferably 0.03 to 1.50 mm, more preferably 0.08 to 1.00 mm, and even more preferably 0.12 to 0.50 mm. When the thickness of the nonwoven fabric a is equal to or less than the upper limit, the overall thickness of the laminate 10 is less likely to be large, and the laminate 10 has an excellent feel when used as a towel substitute, for example. The thickness of the nonwoven fabric a is a value measured in accordance with JIS L 1913:2010. If the nonwoven fabric a is embossed, the thickness of the embossed portion of the nonwoven fabric a that is parallel to the table when the nonwoven fabric a is placed on the table is measured.

[0058] The basis weight of nonwoven fabric a is 10 to 250 g / m 2 is preferable, and 20 to 200 g / m 2 More preferably, 30 to 150 g / m 2 is more preferable. When the basis weight of nonwoven fabric a is equal to or greater than the lower limit, laminate 10 having excellent strength can be obtained. When the basis weight of nonwoven fabric a is equal to or less than the upper limit, laminate 10 having reduced rigidity can be obtained, and therefore, when laminate 10 is used as a substitute for a towel, for example, good workability can be obtained. The basis weight of the nonwoven fabric a is a value measured in accordance with JIS L 1913:2010.

[0059] The water absorption capacity of nonwoven fabric a is 100 g / m 2 More than 200g / m 2 More preferably, 300 g / m 2The above is more preferable. There is no particular upper limit to the water absorption capacity of nonwoven fabric a. The water absorption capacity of nonwoven fabric a is measured as follows: Nonwoven fabric a is cut into 10 cm squares, the mass is measured, the pieces are placed in a 50-mesh basket, and the basket is immersed in a container containing distilled water for 5 minutes. After the basket is removed and the mass is measured 1 minute later, the mass of the basket and nonwoven fabric a before immersion is subtracted from the calculated value, converted to square meters, and this is the water absorption capacity of nonwoven fabric a.

[0060] Examples of fibers constituting the nonwoven fabric a include the raw material fibers A exemplified above in the description of the nonwoven fabric A. Examples of nonwoven fabrics a include dry nonwoven fabrics such as airlaid nonwoven fabrics, spunlace nonwoven fabrics, needle-punched nonwoven fabrics, resin-bonded nonwoven fabrics, and thermal-bonded nonwoven fabrics; melt-spun nonwoven fabrics such as spunbonded nonwoven fabrics and melt-blown nonwoven fabrics; and wetlaid nonwoven fabrics. Among these, airlaid nonwoven fabrics (e.g., pulp airlaid nonwoven fabrics), spunlace nonwoven fabrics (e.g., cotton spunlace nonwoven fabrics, rayon spunlace nonwoven fabrics), and wetlaid nonwoven fabrics are preferred from the viewpoint of excellent water absorbency.

[0061] As the nonwoven fabric a, one sheet of nonwoven fabric a may be used, or two or more sheets of nonwoven fabric a may be used. However, it is preferable to use one sheet of nonwoven fabric a, since the overall thickness of the laminate 10 is less likely to increase and the laminate 10 has an excellent feel when used as a substitute for a towel, for example.

[0062] (Non-woven fabric b) The nonwoven fabric b becomes the second layer 12 that constitutes the laminate 10, that is, the nonwoven fabric B, through a bonding process. The apparent specific gravity of nonwoven fabric b is 0.130 g / cm 3 is less than or equal to 0.110 g / cm 3 Preferably less than 0.090 g / cm 3 More preferably, 0.030 g / cm or less 3 More than 0.050 g / cm is preferable. 3 More preferably, 0.065 g / cm or more 3The above is even more preferable. When the apparent specific gravity of nonwoven fabric b is equal to or greater than the above lower limit, nonwoven fabric b can sufficiently retain water after absorbing it. When the apparent specific gravity of nonwoven fabric b is equal to or less than the above upper limit, a laminate 10 having excellent spot water absorbency can be obtained. The above upper and lower limits can be combined arbitrarily. For example, the apparent specific gravity of nonwoven fabric b is 0.130 g / cm 3 or less, 0.030 to 0.130 g / cm 3 is preferable, and 0.050 to 0.110 g / cm 3 More preferably, 0.065 to 0.090 g / cm 3 is more preferable.

[0063] The thickness of nonwoven fabric b is preferably 0.50 to 2.80 mm, more preferably 0.65 to 2.20 mm, and even more preferably 0.75 to 1.70 mm. If the thickness of nonwoven fabric b is equal to or greater than the lower limit, a sufficient amount of water absorption can be achieved. If the thickness of nonwoven fabric b is equal to or less than the upper limit, the overall thickness of laminate 10 is less likely to be large, and laminate 10 will have an excellent feel when used as, for example, a towel substitute. The thickness of the nonwoven fabric b is a value measured in accordance with JIS L 1913:2010. If the nonwoven fabric b is embossed, the thickness of the embossed portion of the nonwoven fabric b that is parallel to the table when the nonwoven fabric b is placed on the table is measured.

[0064] The basis weight of nonwoven fabric b is 30 to 200 g / m 2 is preferable, and 40 to 160 g / m 2 More preferably, 50 to 120 g / m 2 When the basis weight of nonwoven fabric b is equal to or greater than the above lower limit, a laminate 10 having superior spot water absorbency can be obtained. When the basis weight of nonwoven fabric b is equal to or less than the above upper limit, the adhesiveness between the fibers constituting nonwoven fabric b can be maintained, and the breaking strength can be increased. The basis weight of the nonwoven fabric b is a value measured in accordance with JIS L 1913:2010.

[0065] The water absorption capacity of nonwoven fabric b is 650 g / m 2More than 850g / m 2 More preferably, 1050 g / m 2 The above is more preferable. There is no particular upper limit to the water absorption capacity of nonwoven fabric b. The water absorption capacity of nonwoven fabric b is measured as follows: Nonwoven fabric b is cut into 10 cm squares, the mass is measured, the pieces are placed in a 50-mesh basket, and the basket is immersed in a container containing distilled water for 5 minutes. After the basket is removed and the mass is measured 1 minute later, the mass of the basket and nonwoven fabric b before immersion is subtracted from the calculated value, converted to square meters, and this is the water absorption capacity of nonwoven fabric b.

[0066] Examples of fibers constituting the nonwoven fabric b include the raw material fibers B exemplified above in the description of the nonwoven fabric B. Examples of nonwoven fabric b include dry nonwoven fabrics such as airlaid nonwoven fabrics, spunlace nonwoven fabrics, needle-punched nonwoven fabrics, resin-bonded nonwoven fabrics, and thermal-bonded nonwoven fabrics; melt-spun nonwoven fabrics such as spunbonded nonwoven fabrics and melt-blown nonwoven fabrics; and wetlaid nonwoven fabrics. Among these, airlaid nonwoven fabrics (e.g., pulp airlaid nonwoven fabrics), spunlace nonwoven fabrics (e.g., cotton spunlace nonwoven fabrics, rayon spunlace nonwoven fabrics), and wetlaid nonwoven fabrics are preferred from the viewpoint of excellent water absorbency, and among these, airlaid nonwoven fabrics are particularly preferred from the viewpoint of facilitating bonding of the first layer and the second layer when through holes are formed.

[0067] As the nonwoven fabric b, one sheet of nonwoven fabric b may be used, or two or more sheets of nonwoven fabric b may be used. However, it is preferable to use one sheet of nonwoven fabric b, since the overall thickness of the laminate 10 is less likely to increase and the laminate 10 has an excellent feel when used as a substitute for a towel, for example.

[0068] An example of a combination of nonwoven fabric a and nonwoven fabric b is shown below. A combination in which nonwoven fabric A is a wet-laid nonwoven fabric and nonwoven fabric B is an air-laid nonwoven fabric. A combination in which nonwoven fabric A is a spunlace nonwoven fabric and nonwoven fabric B is an airlaid nonwoven fabric. A combination in which nonwoven fabric A is an airlaid nonwoven fabric and nonwoven fabric B is an airlaid nonwoven fabric. A combination in which nonwoven fabric A is a spunlace nonwoven fabric and nonwoven fabric B is a spunlace nonwoven fabric. A combination in which nonwoven fabric A is a wet-laid nonwoven fabric and nonwoven fabric B is a spunlace nonwoven fabric.

[0069] An example of a method for manufacturing the laminate 10 using the manufacturing apparatus 20 will be described below. The method for manufacturing the laminate of this embodiment includes the joining step and cutting step described below.

[0070] (Joining process) In the joining step, first, nonwoven fabric a and nonwoven fabric b are laminated together to obtain an intermediate body 14 (hereinafter, this step is also particularly referred to as the "lamination step"). Specifically, the nonwoven fabric b delivered from the second delivery roll 212 is laminated on the nonwoven fabric a delivered from the first delivery roll 211 to obtain the intermediate 14. As the nonwoven fabric b, it is preferable to use an air-laid nonwoven fabric. When a nonwoven fabric other than an air-laid nonwoven fabric is used as the nonwoven fabric b, it is preferable to laminate the nonwoven fabric b on the nonwoven fabric a via an adhesive.

[0071] Next, the intermediate 14 is transported to the slitting means 22 and supplied between the slit roll 221 and the nip roll 222. As the intermediate 14 supplied between the slit roll 221 and the nip roll 222 passes between the slit roll 221 and the nip roll 222, a slit blade provided on the slit roll 221 forms a plurality of slit-shaped through-holes penetrating the nonwoven fabrics a and b in a staggered pattern such that the longitudinal direction of the through-holes is parallel to the transport direction of the intermediate 14 (hereinafter, this process is also referred to as the "slitting process"). In particular, when the nonwoven fabric b is an air-laid nonwoven fabric, the through-holes are formed and the nonwoven fabrics a and b are bonded together without the use of an adhesive, so that the nonwoven fabric a becomes the first layer, i.e., the nonwoven fabric A, and the nonwoven fabric b becomes the second layer, i.e., the nonwoven fabric B. In this way, a strip-shaped laminate 10 is obtained in which through-holes are provided and the first layer of nonwoven fabric A and the second layer of nonwoven fabric B are bonded together.

[0072] The inter-roll pressure between the slit roll 221 and the nip roll 222 when forming the through holes is preferably 0.5 to 50 MPa, more preferably 1 to 30 MPa, and even more preferably 5 to 20 MPa. If the inter-roll pressure is equal to or greater than the above lower limit, the processed nonwoven fabrics, i.e., nonwoven fabrics A and B, can be satisfactorily perforated. If the inter-roll pressure is equal to or less than the above upper limit, nonwoven fabrics A and B can be prevented from being excessively crushed.

[0073] When through holes are provided in the intermediate 14, thickness collapse may occur in the laminate 10 due to the pressure (pressure between the rolls) applied when nonwoven fabric a and nonwoven fabric b are stacked and slit. In other words, the actual thickness (real thickness) of the laminate 10 may be thinner than the calculated thickness obtained by adding the thickness of nonwoven fabric a and the thickness of nonwoven fabric b. Furthermore, the pressure applied when nonwoven fabrics a and b are stacked and slit may cause thickness collapse in nonwoven fabrics a and b. That is, after passing through the slitting means 22, the thickness of nonwoven fabric a becomes thinner than before passing through, and as a result, the apparent specific gravity may increase. Therefore, nonwoven fabric a becomes the first layer, i.e., nonwoven fabric A, through the joining process, but the apparent specific gravity of nonwoven fabric A may be greater than the apparent specific gravity of nonwoven fabric a. Similarly, nonwoven fabric b becomes the second layer, i.e., nonwoven fabric B, through the joining process, but the apparent specific gravity of nonwoven fabric B may be greater than the apparent specific gravity of nonwoven fabric b.

[0074] Furthermore, in the manufacturing method of this embodiment, the intermediate 14 is transported to the slit processing means 22 so that the nonwoven fabric a and the slit roll 221 are in contact with each other, and slits (through holes) are made from the nonwoven fabric a side, but the nonwoven fabric a and the nonwoven fabric b may be reversed. That is, the intermediate 14 may be transported to the slit processing means 22 so that the nonwoven fabric b and the slit roll 221 are in contact with each other, and slits (through holes) may be made from the nonwoven fabric b side.

[0075] (cutting process) The cutting step is a step of cutting the strip-shaped laminate 10 provided with through holes to a desired size. Specifically, the strip-shaped laminate 10 having through holes formed therein is conveyed to the cutting means 23. The strip-shaped laminate 10 conveyed to the cutting means 23 is cut by a cutter 231 in a direction perpendicular to the conveyance direction of the strip-shaped laminate 10 (also referred to as the "width direction of the laminate 10") to a desired size, thereby obtaining individual sheets of the laminate 10. In this way, a laminate 10 is obtained, as shown in Figures 1 and 2, in which the first layer 11 and the second layer 12 are bonded together and a plurality of slit-shaped through holes 13 are arranged in a staggered pattern through the first layer 11 and the second layer 12.

[0076] <Action and effect> The laminate of this embodiment described above has an apparent specific gravity of 0.075 g / cm 3 Since the laminate has the first layer made of the nonwoven fabric A having the above properties, the laminate has excellent water absorption in the planar direction and good strength. 3 Since the second layer is nonwoven fabric B described below, the laminate also has excellent water absorption in the thickness direction (stacking direction). Therefore, for example, when water is absorbed from the second layer side, the second layer quickly absorbs water in the stacking direction, while the water that reaches the first layer is absorbed while diffusing in the planar direction. Since the second layer absorbs water in spots, there is a large area on the surface of the second layer that is dry and does not absorb water. Normally, it takes time to find a dry area as you continue wiping, but with the laminate of the present invention, you can wipe efficiently and quickly without having to search for a dry area on the second layer. Note that when water is absorbed from the first layer side, water is drawn into the second layer in spots, while the first layer absorbs it in the planar direction. Thus, the laminate of the present invention has a high water absorption capacity and excellent strength.

[0077] <Application> The laminate of the present invention can be used as a substitute for towels and is suitable as a disposable towel, particularly for wiping off moisture from hair or pet hair after washing, for wiping hands after hand washing, for cleaning, for use on objects, etc. Furthermore, as described above, if the laminate is stretched and the through-holes are expanded into a diamond or tortoiseshell shape to form a mesh-like laminate 10 as shown in Fig. 3, it will be possible to absorb moisture over a wide area at once. Note that when it is desired to absorb moisture locally, the laminate may be used as is without forming the laminate into a mesh shape. When the laminate is allowed to absorb water, the water may be absorbed from the first layer side or the second layer side.

[0078] <Other embodiments> The laminate of the present invention is not limited to the laminate 10 shown in FIGS. For example, when nonwoven fabric B is an airlaid nonwoven fabric, the first layer 11 and the second layer 12 can be bonded without using adhesive by providing through holes 13 arranged in a staggered pattern, but the first layer 11 and the second layer 12 may be bonded via an adhesive layer (not shown), and the laminate 10 may not have through holes 13. However, from the viewpoint that the first layer 11 and the second layer 12 can be easily joined by providing the through holes 13 and that the environmental load and manufacturing costs can be reduced compared to when the layers are joined via an adhesive layer, it is preferable that the first layer 11 and the second layer 12 are joined by providing the through holes 13 without using an adhesive layer. Examples of adhesives that can be used to form the adhesive layer include polyvinyl acetate (PVA) adhesives, acrylic adhesives, ethylene vinyl acetate (EVA) adhesives, natural rubber adhesives, and synthetic rubber adhesives.

[0079] Furthermore, although the laminate 10 shown in Figures 1 to 3 includes a first layer 11 and a second layer 12, the laminate may further include layers other than these (hereinafter also referred to as "other layers") in addition to the first layer and the second layer, as long as the effects of the present invention are not impaired. The other layer may be located on the other side of the first layer and in contact with the first layer, or may be located on the side of the second layer opposite to the side in contact with the first layer and in contact with the second layer. The other layer is preferably a nonwoven fabric, which may be a dry-laid nonwoven fabric, a melt-spun nonwoven fabric, or a wet-laid nonwoven fabric. When the laminate further includes other layers, the through-holes preferably penetrate the other layers in addition to the first and second layers. [Example]

[0080] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The embodiments of the present invention can be modified in various ways as long as the gist of the present invention is not changed.

[0081] [Nonwoven fabric] <Nonwoven fabric a-1> An embossed wet-laid nonwoven fabric (manufactured by Oji Nepia Co., Ltd., product name "Kitchen Towel Super Absorbent") was used as nonwoven fabric a-1. The apparent specific gravity of nonwoven fabric a-1 was 0.226 g / cm 3 The water absorption is 446g / m 2 The thickness is 0.19 mm and the basis weight is 43 g / m 2 It was.

[0082] <Nonwoven fabric a-2> A spunlace nonwoven fabric (manufactured by Shinwa Co., Ltd., product name "7128") was used as nonwoven fabric a-2. The apparent specific gravity of nonwoven fabric a-2 was 0.140 g / cm 3 The water absorption is 458g / m 2 The thickness is 0.20 mm and the basis weight is 28 g / m 2 It was.

[0083] <Nonwoven fabric b-1> A dry pulp airlaid nonwoven fabric (manufactured by Oji Kinocloth Co., Ltd., product name "KO-65") was used as nonwoven fabric b-1. The apparent specific gravity of nonwoven fabric b-1 was 0.046 g / cm 3 The water absorption is 1422g / m 2The thickness is 1.40 mm and the basis weight is 65 g / m 2 It was.

[0084] <Nonwoven fabric b-2> A dry pulp airlaid nonwoven fabric (manufactured by Oji Kinocloth Co., Ltd., product name "AU-100E") was used as nonwoven fabric b-2. The apparent specific gravity of nonwoven fabric b-2 was 0.056 g / cm 3 The water absorption is 2033g / m 2 The thickness is 1.80 mm and the basis weight is 100 g / m 2 It was.

[0085] [Measurement and evaluation] <Thickness measurement> The cross section of the laminate was observed under a microscope at any three points on the laminate, and the average values ​​of the thicknesses of the first layer, second layer and laminate were determined from the images. An electron microscope (manufactured by Hitachi High-Technologies Corporation, product name "FLexSEM1000") was used to observe the cross section of the laminate at a magnification of 65 times.

[0086] <Measurement of basis weight> The basis weight of the laminate was measured in accordance with JIS P 8124:2011. The first layer was peeled from the laminate, and the basis weight of the first layer was measured in accordance with JIS P 8124:2011. The basis weight of the second layer was determined by subtracting the basis weight of the first layer from the basis weight of the laminate.

[0087] <Measurement of water absorption> The first layer was peeled off from the laminate, and the peeled first layer was cut into 10 cm square pieces, the mass was measured, and the pieces were placed in a 50 mesh basket and immersed in a container containing distilled water for 5 minutes.The basket was then removed and the mass was measured 1 minute later, and the mass of the basket and the first layer before immersion was subtracted from the result, converted to square meter, and this was determined as the water absorption amount of the first layer. Similarly, the second layer was peeled off from the laminate, and the peeled second layer was cut into 10 cm square pieces, which were then used to measure the amount of water absorption of the second layer. Similarly, the laminate was cut into 10 cm square pieces and the amount of water absorption of the laminate was measured.

[0088] <Evaluation of water absorbency> The laminate was cut into a 10 cm square to prepare a test piece. Using a dropper, 1 mL of blue-dyed distilled water was dropped onto the center of one surface of the test piece from a height of 3 cm. Ten seconds after the drop, the diffusion distance of the water in the machine direction (MD) and cross direction (CD) was measured with a ruler. The longer the diffusion distance, the better the water absorbency in the planar direction of the laminate. The MD direction is the direction parallel to the length of the through-holes.

[0089] <Strength evaluation> The laminate was cut into test pieces of 5 cm in the longitudinal direction (MD) of the through holes and 15 cm in the direction tilted 90° from the longitudinal direction of the through holes (CD). The obtained test pieces were subjected to a tensile test using a Tensilon tensile tester (manufactured by Orientec Co., Ltd., product name "RTM-100" or "RTG-1210") under conditions of a span of 100 mm and a tensile speed of 200 mm / min, and the tensile strength was calculated from the obtained SS curve, which was used as the strength of the laminate.

[0090] [Example 1] A laminate was produced using the production apparatus 20 shown in FIG. 4 as follows. First, nonwoven fabric a-1 was fed from a first feed roll 211, and separately, nonwoven fabric b-1 was fed from a second feed roll 212. The nonwoven fabric b-1 fed from the second feed roll 212 was laminated on the nonwoven fabric a-1 fed from the first feed roll 211, thereby obtaining an intermediate 14. Next, the intermediate 14 was transported to slit processing means 22 and supplied between slit roll 221 and nip roll 222. A slit blade provided on slit roll 221 formed nonwoven fabric a-1 and a plurality of slit-shaped through holes penetrating nonwoven fabric a-1 in a staggered pattern so that the longitudinal direction of the through holes was parallel to the transport direction of intermediate 14, and nonwoven fabric a-1 and nonwoven fabric b-1 were bonded together, with nonwoven fabric a-1 becoming the first layer, i.e., nonwoven fabric A, and nonwoven fabric b-1 becoming the second layer, i.e., nonwoven fabric B, to obtain a strip-shaped laminate 10. The length L of the through holes was 10 mm, the distance D between adjacent through holes in a row of through holes was 3 mm, and the width W of adjacent rows of through holes was 2 mm. Next, the strip-shaped laminate 10 was transported to cutting means 23, and cut into the desired size by a cutter 231 in a direction perpendicular to the transport direction of the strip-shaped laminate 10, thereby obtaining a single-sheet laminate 10 having a length of 20 cm, a width of 30 cm and a thickness of 0.96 mm, in which the first layer and the second layer were joined. The thickness, basis weight, and water absorption of the first layer and second layer of the obtained laminate 10 were measured. The water absorption and strength of the laminate 10 were also evaluated. The results are shown in Table 1. The first layer constituting the laminate produced using nonwoven fabric a-1 is also referred to as "nonwoven fabric A-1," and the second layer constituting the laminate produced using nonwoven fabric b-1 is also referred to as "nonwoven fabric B-1." Similarly, in the following examples and comparative examples, the first layer constituting the laminate produced using nonwoven fabric a-2 is also referred to as "nonwoven fabric A-2," and the second layer constituting the laminate produced using nonwoven fabric b-2 is also referred to as "nonwoven fabric B-2."

[0091] [Example 2] A laminate was produced in the same manner as in Example 1, except that the length L of the through holes was 15 mm, the distance D between adjacent through holes in a row of through holes was 5 mm, and the width W of adjacent rows of through holes was 5 mm, and various measurements and evaluations were carried out. The results are shown in Table 1.

[0092] [Example 3] A laminate was produced in the same manner as in Example 1, except that no through holes were provided and nonwoven fabric a-1 and nonwoven fabric b-1 were bonded together using an adhesive (product name "Spray Glue 77" manufactured by 3M Japan Ltd.), and various measurements and evaluations were carried out. The results are shown in Table 1.

[0093] [Example 4] Except for using nonwoven fabric b-2 instead of nonwoven fabric b-1, a laminate was produced in the same manner as in Example 1, and various measurements and evaluations were carried out. The results are shown in Table 2.

[0094] [Example 5] A laminate was produced in the same manner as in Example 1, except that nonwoven fabric b-2 was used instead of nonwoven fabric b-1, and the length L of the through holes was 15 mm, the distance D between adjacent through holes in a row of through holes was 5 mm, and the width W of adjacent rows of through holes was 5 mm, and various measurements and evaluations were performed. The results are shown in Table 2.

[0095] [Example 6] A laminate was produced in the same manner as in Example 1, except that nonwoven fabric b-2 was used instead of nonwoven fabric b-1, and nonwoven fabric a-1 and nonwoven fabric b-2 were bonded together using an adhesive (product name "Spray Glue 77" manufactured by 3M Japan Ltd.) without providing through holes, and various measurements and evaluations were carried out. The results are shown in Table 2.

[0096] [Example 7] A laminate was produced in the same manner as in Example 1, except that nonwoven fabric a-2 was used instead of nonwoven fabric a-1, and the length L of the through holes was 15 mm, the distance D between adjacent through holes in a row of through holes was 5 mm, and the width W of adjacent rows of through holes was 5 mm, and various measurements and evaluations were performed. The results are shown in Table 3.

[0097] [Example 8] A laminate was produced in the same manner as in Example 1, except that nonwoven fabric a-2 was used instead of nonwoven fabric a-1, nonwoven fabric b-2 was used instead of nonwoven fabric b-1, the length L of the through holes was 15 mm, the distance D between adjacent through holes in a row of through holes was 5 mm, and the width W of adjacent rows of through holes was 5 mm, and various measurements and evaluations were performed. The results are shown in Table 3.

[0098] [Comparative Example 1] A laminate was produced in the same manner as in Example 1, except that nonwoven fabric b-1 was used instead of nonwoven fabric a-1, and the length L of the through holes was 15 mm, the distance D between adjacent through holes in a row of through holes was 5 mm, and the width W of adjacent rows of through holes was 5 mm, and various measurements and evaluations were performed. The results are shown in Table 4.

[0099] Comparative Example 2 A laminate was produced in the same manner as in Example 1, except that nonwoven fabric b-1 was used instead of nonwoven fabric a-1, and the nonwoven fabric b-1 pieces were bonded together using an adhesive (product name "Spray Glue 77" manufactured by 3M Japan Ltd.) without providing through holes, and various measurements and evaluations were carried out. The results are shown in Table 4.

[0100] Comparative Example 3 A laminate was produced in the same manner as in Example 1, except that nonwoven fabric b-2 was used instead of nonwoven fabric a-1, nonwoven fabric b-2 was used instead of nonwoven fabric b-1, the length L of the through holes was 15 mm, the distance D between adjacent through holes in a row of through holes was 5 mm, and the width W of adjacent rows of through holes was 5 mm, and various measurements and evaluations were performed. The results are shown in Table 4.

[0101] Comparative Example 4 A laminate was produced in the same manner as in Example 1, except that nonwoven fabric b-2 was used instead of nonwoven fabric a-1, nonwoven fabric b-2 was used instead of nonwoven fabric b-1, and nonwoven fabric b-2 was bonded together without through-holes using an adhesive (manufactured by 3M Japan Ltd., product name "Spray Glue 77"), and various measurements and evaluations were carried out. The results are shown in Table 4.

[0102] Comparative Example 5 A laminate was produced in the same manner as in Example 1, except that nonwoven fabric a-2 was used instead of nonwoven fabric a-1, nonwoven fabric a-2 was used instead of nonwoven fabric b-1, the length L of the through holes was 15 mm, the distance D between adjacent through holes in a row of through holes was 5 mm, and the width W of adjacent rows of through holes was 5 mm, and various measurements and evaluations were performed. The results are shown in Table 4.

[0103] Comparative Example 6 A laminate was produced in the same manner as in Example 1, except that nonwoven fabric a-2 was used instead of nonwoven fabric a-1, nonwoven fabric a-2 was used instead of nonwoven fabric b-1, and nonwoven fabric a-2 was bonded to itself using an adhesive (product name "Spray Glue 77" manufactured by 3M Japan Ltd.) without providing through holes, and various measurements and evaluations were carried out. The results are shown in Table 4.

[0104] [Table 1]

[0105] [Table 2]

[0106] [Table 3]

[0107] [Table 4]

[0108] As is clear from the results in Tables 1 to 3, the laminates obtained in Examples 1 to 8 had high water absorption and excellent strength when water was absorbed. On the other hand, as is clear from the results in Table 4, the laminates obtained in Comparative Examples 1 to 4 had poor water absorbency on the first layer side. In particular, the laminates obtained in Comparative Examples 1 and 2 also had low strength. The laminates obtained in Comparative Examples 5 and 6 had good water absorption on the first layer side, but compared with Examples 7 and 8, the amount of water absorption of the entire laminate was low. [Explanation of symbols]

[0109] 10 Laminate 11 First Layer 11a One side 12 Second Layer 13 Through hole 14 Intermediates 20 Manufacturing equipment 21 Lamination means 211 First delivery roll 212 Second delivery roll 22 Slitting method 221 Slit Roll 222 Nip Roll 23 Cutting means 231 Cutting machine

Claims

1. A laminate comprising a first layer and a second layer located on one surface of the first layer and in contact with the first layer, The first layer has an apparent specific gravity of 0.075 g / cm ３ The nonwoven fabric is as described above. The second layer has an apparent specific gravity of 0.120 g / cm ３ A nonwoven fabric that is: A laminate, wherein the apparent specific gravity of the first layer is greater than the apparent specific gravity of the second layer.

2. 10. The laminate of claim 1, wherein the second layer is an airlaid nonwoven.

3. the first layer and the second layer are bonded together; The laminate according to claim 1 , wherein a plurality of slit-shaped through-holes penetrating the first layer and the second layer are provided in a staggered pattern.

4. A method for producing the laminate according to any one of claims 1 to 3, Apparent specific gravity is 0.075 g / cm ３ and nonwoven fabric a having an apparent specific gravity of 0.130 g / cm ３ a joining step of joining the nonwoven fabric b to the nonwoven fabric b, The nonwoven fabric a is the first layer, The method for producing a laminate, wherein the nonwoven fabric b is the second layer.

5. The method for producing a laminate according to claim 4 , wherein the bonding step is a step of providing a plurality of slit-shaped through-holes penetrating the first layer and the second layer in a staggered pattern.

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