Nonwoven fabric for wet wipes, wet wipes, package of wet wipes, and use of water-repellent cellulose fibers

Abstract

The purpose of the present disclosure is to provide a nonwoven fabric for wet wipes, said wet wipes formed of said nonwoven fabric having superior properties allowing easy taking out from a package.　More specifically, this nonwoven fabric for wet wipes is characterized in that it contains water-repellent cellulose fibers.

Description

Nonwoven fabric for wet wipes, wet wipes, packaging for wet wipes, and use of water-repellent cellulosic fibers

[0001] The present disclosure relates to nonwoven fabrics for wet wipes, wet wipes, packaging for wet wipes, and uses of water-repellent cellulosic fibers.

[0002] In the case of packaging for wet wipes, wet tissues, etc., particularly pop-up packaging, when removing one wet wipe from the packaging, multiple wet wipes, including the next wet wipe, may be removed at once (hereinafter, this may be referred to as the "tendency to remove multiple wipes").

[0003] Studies have been conducted to solve the problem associated with such a tendency to dispense multiple wipes. For example, Patent Document 1 discloses wet wipes comprising a nonwoven fabric produced by a wet process and a chemical solution impregnated into the nonwoven fabric, wherein the nonwoven fabric comprises 5 to 40% by mass of synthetic fibers having a specific gravity of more than 1.0 and 60 to 95% by mass of cellulosic fibers, and the synthetic fibers comprise 20 to 100% by mass of synthetic fibers having an irregular cross-sectional shape.

[0004] Furthermore, Patent Document 2 discloses wet wipes comprising a nonwoven fabric and a chemical solution impregnated in the nonwoven fabric, characterized in that the nonwoven fabric comprises hydrophobic fibers, and the chemical solution comprises (i) a cationic surfactant, (ii) a low HLB surfactant having an HLB of 3.0 to 7.0, and (iii) water.

[0005] JP 2014-94188 A JP 2022-92982 A

[0006] The wet wipes according to the present disclosure are not disclosed in Patent Documents 1 and 2. An object of the present disclosure is to provide a nonwoven fabric for wet wipes that has excellent removability when formed from the nonwoven fabric.

[0007] The present inventors have discovered a nonwoven fabric for wet wipes, characterized in that the nonwoven fabric contains water-repellent cellulosic fibers.

[0008] The nonwoven fabric for wet wipes according to the present disclosure has excellent removability of wet wipes formed from the nonwoven fabric.

[0009] Fig. 1 is a diagram illustrating a wet wipes package 1 according to a first embodiment. Fig. 2 is an end view of the wet wipes package 1 taken along the line II-II. Fig. 3 is a diagram illustrating a plurality of wet wipes 9. Fig. 4 is an end view of the wet wipes package 1 according to a second embodiment.

[0010] Specifically, the present disclosure relates to the following aspects: [Aspect 1] A nonwoven fabric for wet wipes, the nonwoven fabric comprising water-repellent cellulosic fibers.

[0011] The nonwoven fabric includes water-repellent cellulosic fibers that are water-repellent but can retain a certain amount of moisture within the fibers once wet, and have a certain degree of swelling in water.

[0012] The water-repellent cellulosic fibers are hydrophobic and have high chemical solution retention and equivalent or higher water repellency than synthetic fibers, hydrophobic fibers, and the like that do not retain moisture (hereinafter, sometimes referred to as "hydrophobic fibers, etc."). Therefore, the nonwoven fabric containing the water-repellent cellulosic fibers according to the present invention has (i) high chemical solution retention and (ii) equivalent or higher water repellency due to the properties of the water-repellent cellulosic fibers compared to nonwoven fabrics that contain hydrophobic fibers, etc. instead of the water-repellent cellulosic fibers. As a result, wet wipes formed from nonwoven fabrics containing the water-repellent cellulosic fibers are less likely to stick together and more likely to separate than wet wipes formed from nonwoven fabrics that contain hydrophobic fibers, etc. instead of the water-repellent cellulosic fibers.

[0013] Furthermore, the water-repellent cellulosic fibers have the same chemical solution retention capacity and high water repellency as ordinary cellulosic fibers that have not been treated for water repellency (hereinafter, to distinguish them from water-repellent cellulosic fibers, "ordinary cellulosic fibers that have not been treated for water repellency" may be referred to as "hydrophilic cellulosic fibers"). Therefore, the nonwoven fabric containing the water-repellent cellulosic fibers according to the present invention has (i) the same chemical solution retention capacity and (ii) high water repellency due to the properties of the water-repellent cellulosic fibers as compared to nonwoven fabrics that contain hydrophilic cellulosic fibers instead of water-repellent cellulosic fibers. As a result, wet wipes formed from nonwoven fabrics containing the water-repellent cellulosic fibers are less likely to stick together and more likely to separate than wet wipes formed from nonwoven fabrics that contain hydrophilic cellulosic fibers instead of water-repellent fibers.

[0014] For example, when wet wipes made from the nonwoven fabric are folded along a fold line, adjacent wet wipe portions separated by the fold line are less likely to stick together and are more likely to separate, making it easier to unfold from the folded state. Furthermore, when multiple wet wipes made from the nonwoven fabric are stacked, adjacent wet wipe portions in the stacking direction are less likely to stick together and are more likely to separate, making it less likely that multiple wet wipes, including the next wet wipe, will be removed at once when one wet wipe is removed. The tendency to remove multiple wet wipes tends to increase as the wet wipe holds a larger amount of chemical solution. As a result, wet wipes made from the nonwoven fabric have excellent removal properties.

[0015] Furthermore, since the water-repellent cellulosic fibers contained in the nonwoven fabric are biodegradable, the nonwoven fabric, and ultimately the wet wipes formed from the nonwoven fabric, are more likely to biodegrade than nonwoven fabrics that contain hydrophobic fibers instead of water-repellent cellulosic fibers, thereby reducing the environmental impact.

[0016] [Aspect 2] The nonwoven fabric according to Aspect 1, wherein the nonwoven fabric has a water absorbency of 60 to 110 mm according to the Klemm method. Because the nonwoven fabric has a predetermined water absorbency according to the Klemm method, in wet wipes formed from the nonwoven fabric, the wet wipe portions are less likely to stick to each other and are more likely to separate, resulting in excellent ease of removal of the wet wipes formed from the nonwoven fabric.

[0017] [Aspect 3] The nonwoven fabric according to Aspect 1 or 2, wherein the nonwoven fabric contains 10 to 35% by mass of the water-repellent cellulosic fibers. Because the nonwoven fabric contains a predetermined amount of water-repellent cellulosic fibers, wet wipes formed from the nonwoven fabric are less likely to stick to each other and are more likely to separate, resulting in excellent removal properties of the wet wipes formed from the nonwoven fabric.

[0018] [Aspect 4] The nonwoven fabric according to any one of Aspects 1 to 3, wherein the water-repellent cellulosic fibers have a water swelling degree of 10 to 80% by mass. In the nonwoven fabric, since the water-repellent cellulosic fibers have a predetermined water swelling degree, in wet wipes formed from the nonwoven fabric, the wet wipe portions are less likely to stick to each other and are more likely to separate, resulting in excellent removal properties of the wet wipes formed from the nonwoven fabric.

[0019] Aspect 5: The nonwoven fabric according to any one of Aspects 1 to 4, comprising a first surface layer and a second surface layer constituting the surface of the nonwoven fabric, and an intermediate layer disposed between the first surface layer and the second surface layer, wherein each of the first surface layer and the second surface layer contains the water-repellent cellulosic fiber, and the intermediate layer contains heat-fusible fiber.

[0020] The nonwoven fabric has a predetermined structure, and the first and second surface layers each contain water-repellent cellulosic fibers, so that in wet wipes formed from the nonwoven fabric, the wet wipe portions are less likely to stick together and are more likely to separate, resulting in excellent removal properties. Furthermore, the intermediate layer contains heat-fusible fibers, so that the wet wipes formed from the nonwoven fabric have excellent wet strength and are less likely to feel stiff due to the heat-fusible fibers.

[0021] [Aspect 6] The nonwoven fabric according to Aspect 5, wherein the heat-fusible fibers include biodegradable heat-fusible fibers. In the nonwoven fabric, the heat-fusible fibers include biodegradable heat-fusible fibers, which makes the nonwoven fabric, and therefore the wet wipes, more likely to be biodegradable.

[0022] [Aspect 7] The nonwoven fabric according to aspect 5 or 6, wherein each of the first surface layer and the second surface layer is composed of cellulosic fibers.

[0023] In the above nonwoven fabric, the first surface layer and the second surface layer are each made of cellulosic fibers, so in wet wipes formed from the above nonwoven fabric, the chemical solution is more easily retained in the first surface layer and the second surface layer, making the wet wipes more likely to have excellent wiping properties.

[0024] [Aspect 8] The nonwoven fabric according to any one of aspects 5 to 7, wherein the intermediate layer further contains pulp fibers.

[0025] In the nonwoven fabric, the intermediate layer further contains pulp fibers, so that in wet wipes formed from the nonwoven fabric, the amount of chemical solution held in the intermediate layer is relatively large, and the amounts of chemical solution contained in the first and second surface layers are relatively small. As a result, the amount of chemical solution on the surfaces of the wet wipes (the first and second surface layers) is relatively small, the wet wipes are less likely to stick to each other and are more likely to separate, and the wet wipes formed from the nonwoven fabric have excellent removal properties.

[0026] Aspect 9: A wet wipe comprising a nonwoven fabric sheet made of the nonwoven fabric according to any one of Aspects 1 to 8 and a medicinal solution. The wet wipe has the effects disclosed in Aspect 1.

[0027] [Aspect 10] A wet wipes package in which a plurality of wet wipes are stored inside a package body having a top with an opening and a bottom, wherein at least some of the plurality of wet wipes are composed of the wet wipes described in Aspect 9, and the plurality of wet wipes are stacked in a direction from the bottom to the top.

[0028] The wet wipes packaging has the effects disclosed in Aspect 1.

[0029] [Aspect 11] The wet wipes package according to Aspect 10, wherein the plurality of wet wipes are arranged so that the top end of the bottom wet wipe located on the bottom side and the bottom end of the top wet wipe adjacent to the top side thereof overlap each other, with the top end of the bottom wet wipe being located closer to the top than the bottom end of the top wet wipe.

[0030] The wet wipes package tends to have a low tendency to dispense multiple wipes and a predetermined dispense height, making it easy for the wet wipes user to dispense the required number of wet wipes and then dispense the next wet wipe.

[0031] [Aspect 12] Use of water-repellent cellulosic fibers for adjusting the removability of wet wipes In the above use, the water-repellent cellulosic fibers can adjust the removability of wet wipes.

[0032] The nonwoven fabric for wet wipes (hereinafter sometimes simply referred to as "nonwoven fabric"), wet wipes, and wet wipes packaging (hereinafter sometimes simply referred to as "packaging") according to the present disclosure are described in detail below.

[0033] [Nonwoven Fabric] The nonwoven fabric according to the present disclosure is a nonwoven fabric for wet wipes and contains water-repellent cellulosic fibers. The water-repellent cellulosic fibers are water-repellent cellulosic fibers that exhibit water repellency, but once wetted, can retain a certain amount of moisture within the fibers and have a certain degree of water swelling. Therefore, wet wipes formed from the nonwoven fabric containing the water-repellent cellulosic fibers are less likely to stick together and more likely to separate than wet wipes formed from nonwoven fabrics containing hydrophobic fibers or the like instead of the water-repellent cellulosic fibers, and are more likely to separate than wet wipes formed from nonwoven fabrics containing hydrophilic fibers or the like instead of the water-repellent cellulosic fibers.

[0034] Furthermore, since the water-repellent cellulosic fibers have a certain degree of swelling in water, wet wipes formed from the nonwoven fabric can more easily retain medicinal solutions and have higher water retention than nonwoven fabrics containing hydrophobic fibers instead of water-repellent cellulosic fibers.Furthermore, since the water-repellent cellulosic fibers are biodegradable, the nonwoven fabric, and therefore the wet wipes formed from the nonwoven fabric, are more easily biodegradable, thereby reducing the environmental burden.

[0035] The cellulosic fibers constituting the water-repellent cellulosic fibers include natural cellulosic fibers, regenerated cellulosic fibers, refined cellulosic fibers, and semi-synthetic cellulosic fibers. The natural cellulosic fibers include plant fibers such as pulp fibers, seed hair fibers (e.g., cotton fibers), bast fibers (e.g., hemp), leaf vein fibers (e.g., Manila hemp), and fruit fibers (e.g., palm).

[0036] The pulp fibers include those known in the art as pulp fibers, such as wood pulp fibers and non-wood pulp fibers. Examples of the wood pulp fibers include softwood pulp fibers and hardwood pulp fibers. Examples of the non-wood pulp fibers include straw pulp fibers, bagasse pulp fibers, reed pulp fibers, kenaf pulp fibers, mulberry pulp fibers, bamboo pulp fibers, hemp pulp fibers, and cotton pulp fibers (e.g., cotton linter fibers).

[0037] The cotton fiber includes Hirsutum cotton fiber (e.g., upland cotton), Barbadense cotton fiber, Arboreum cotton fiber, and Helbaceum cotton fiber. The cotton fiber may also be organic cotton fiber or Pre-Organic Cotton (trademark) fiber. Organic cotton fiber refers to cotton certified by GOTS (Global Organic Textile Standard).

[0038] Examples of the regenerated cellulose fibers include rayon, for example, viscose rayon obtained from viscose, polynosic and modal, and cuprammonium rayon (also called "cupra") obtained from a cuprammonium salt solution of cellulose.

[0039] The purified cellulose fiber includes lyocell, specifically, a fiber obtained by dissolving pulp in an aqueous solution of N-methylmorpholine N-oxide to form a spinning dope (dope) and extruding the dope into a dilute solution of N-methylmorpholine N-oxide. The purified cellulose is commercially available, for example, under the trade name Tencel (trademark). The semi-synthetic fiber includes semi-synthetic cellulose, such as acetate fibers, e.g., triacetate and diacetate fibers.

[0040] The water-repellent cellulose fibers can be formed by subjecting the cellulose fibers to a water-repellent treatment using a water-repellent agent or the like according to the methods described in, for example, JP 2002-266241 A, JP 2003-20570 A, JP 2019-65443 A, JP 2022-58301 A, etc. In addition, commercially available examples of the water-repellent cellulose fibers include Ecorepellent (trade name, water-repellent viscose rayon) manufactured by Daiwabo Rayon Co., Ltd. and Olea (trade name, water-repellent viscose rayon) manufactured by Kelheim Fibres GmbH.

[0041] The water repellency of the above-mentioned water-repellent cellulosic fibers can be evaluated as follows, in accordance with "6(1)F Sedimentation Rate" in the "Standards for Medical Gauze and Medical Absorbent Cotton" appendix to Yakushokuki-hatsu No. 0630001, "Standards for Medical Gauze and Medical Absorbent Cotton." A 10-g sample obtained by carding fibers from nonwoven fabrics or wet wipes is placed evenly in a 3-g test basket made of 0.4 mm copper wire, 50 mm in diameter, 80 mm deep, and 20 mm apart. The basket is then gently lowered horizontally into 200 mm of water at a temperature of 24-26°C from a height of 12 mm above the water surface. The sedimentation rate is the time it takes for the basket to sink below the surface. For fibers that cannot be carded (e.g., short fibers), 10 g of the fibers can be placed directly in the test basket. Alternatively, if the textile product is in the form of a wet-laid or air-laid nonwoven, a 10 g piece of the nonwoven cut to a size of 1 cm x 1 cm can be placed in the test basket.

[0042] When the sedimentation rate is measured by the above method, a sample that absorbs water but does not sink below the water surface after, for example, 1 minute, 5 minutes, or 10 minutes is preferably used as a water-repellent cellulosic fiber. A sample that does not sink and remains partially or completely floating on the water surface after 1 minute is even more preferably used as a water-repellent cellulosic fiber.

[0043] The water-repellent cellulosic fibers can be distinguished from hydrophilic cellulosic fibers by their degree of swelling in water. The water-repellent cellulosic fibers preferably have a degree of swelling in water of 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more. The water-repellent cellulosic fibers preferably have a degree of swelling in water of 80% by mass or less, more preferably 70% by mass or less, and even more preferably 60% by mass or less. This makes it possible for wet wipes formed from the nonwoven fabric to be easily separated from each other, without sticking together.

[0044] The hydrophilic cellulosic fibers may have a higher degree of swelling in water than the water-repellent cellulosic fibers. The hydrophilic cellulosic fibers have a degree of swelling in water of, for example, preferably more than 60% by mass, more preferably more than 70% by mass, even more preferably more than 80% by mass, even more preferably 85% by mass or more, and even more preferably 90% by mass or more. The hydrophilic cellulosic fibers also have a degree of swelling in water of preferably 300% by mass or less, more preferably 200% by mass or less, and even more preferably 150% by mass or less.

[0045] The water-repellent cellulosic fiber has a water swelling degree that is preferably at least 5% by mass, more preferably at least 10% by mass, even more preferably at least 15% by mass, even more preferably at least 20% by mass, and even more preferably at least 25% by mass lower than that of a normal cellulosic fiber that does not have water repellency, such as a hydrophilic cellulosic fiber described below. This makes it possible for wet wipes formed from the nonwoven fabric to have wet wipe portions that are less likely to stick together and are easier to separate.

[0046] In the present disclosure, the water swelling degree of a fiber is measured in accordance with "8.26 Water swelling degree" of "Testing methods for synthetic fiber staples" of JIS L1015:2010, and is applicable to fibers other than rayon and cupra.

[0047] The water-repellent cellulosic fibers preferably have an average fiber length of 20 mm or more, more preferably 30 mm or more, and even more preferably 35 mm or more. The water-repellent cellulosic fibers preferably have an average fiber length of 80 mm or less, more preferably 60 mm or less, and even more preferably 50 mm or less. This allows the water-repellent cellulosic fibers to be easily entangled with other fibers, such as water-repellent cellulosic fibers and, optionally, hydrophilic cellulosic fibers, and increases the strength of the nonwoven fabric and, ultimately, the wet wipes.

[0048] The water-repellent cellulosic fibers preferably have a fineness of 0.6 dtex or more, more preferably 1.0 dtex or more, and even more preferably 1.4 dtex or more. The water-repellent cellulosic fibers preferably have a fineness of 3.3 dtex or less, more preferably 2.5 dtex or less, and even more preferably 2.0 dtex or less. This allows the nonwoven fabric containing the water-repellent cellulosic fibers to maintain its texture while suppressing fiber clumping.

[0049] In the present disclosure, the average fiber length of fibers other than pulp fibers is measured in accordance with "A7.1.1 Method A (standard method) - measuring the length of individual fibers on a graduated glass plate" in "A7.1 Measurement of fiber length" of Annex A of JIS L 1015:2010. This method is equivalent to ISO 6989, published in 1981.

[0050] In this disclosure, the average fiber length of pulp fibers refers to the weight-weighted average fiber length, L(w) value as measured by Kajaani FiberLab fiber properties (off-line) manufactured by Metso Automation.

[0051] The nonwoven fabric preferably contains the water-repellent cellulosic fibers in a proportion of more than 0% by mass, more preferably 4% by mass or more, even more preferably 6% by mass or more, even more preferably 8% by mass or more, and even more preferably 10% by mass or more. The nonwoven fabric also preferably contains the water-repellent cellulosic fibers in a proportion of 100% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, even more preferably 50% by mass or less, and even more preferably 35% by mass or less. This provides the nonwoven fabric with a certain affinity for water, and wet wipes formed from the nonwoven fabric are less likely to stick together and are more likely to separate.

[0052] The nonwoven fabric can further contain hydrophilic cellulosic fibers. This makes it easier for the nonwoven fabric itself to retain the medicinal solution, making it less likely for wet wipe portions to stick together and easier for them to separate. Furthermore, since wet wipes formed from the nonwoven fabric are more likely to retain the medicinal solution, water retention is improved. Furthermore, since the hydrophilic cellulosic fibers are biodegradable, the nonwoven fabric, and therefore the wet wipes formed from the nonwoven fabric, are more likely to biodegrade, thereby reducing the environmental impact.

[0053] From the above viewpoint, the nonwoven fabric preferably contains the hydrophilic cellulosic fibers in a proportion of 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, even more preferably 20% by mass or more, and even more preferably 25% by mass or more. The nonwoven fabric also preferably contains the hydrophilic cellulosic fibers in a proportion of 90% by mass or less, more preferably 80% by mass or less, even more preferably 70% by mass or less, even more preferably 60% by mass or less, and even more preferably 50% by mass or less. Examples of cellulosic fibers constituting the hydrophilic cellulosic fibers include those described above in relation to the water-repellent cellulosic fibers.

[0054] When the hydrophilic cellulosic fibers are not pulp fibers, the hydrophilic cellulosic fibers preferably have an average fiber length of 20 mm or more, more preferably 30 mm or more, and even more preferably 35 mm or more. When the hydrophilic cellulosic fibers are not pulp fibers, the hydrophilic cellulosic fibers preferably have an average fiber length of 80 mm or less, more preferably 70 mm or less, and even more preferably 60 mm or less. This makes it easier for the hydrophilic cellulosic fibers to intertwine with each other, which tends to increase the strength of the nonwoven fabric and, ultimately, the wet wipes.

[0055] The hydrophilic cellulosic fibers preferably have a fineness of 0.3 dtex or more, more preferably 0.4 dtex or more, and even more preferably 0.6 dtex or more. The hydrophilic cellulosic fibers preferably have a fineness of 4.5 dtex or less, more preferably 4.0 dtex or less, and even more preferably 3.0 dtex or less. This allows the nonwoven fabric containing the hydrophilic cellulosic fibers to maintain its texture while suppressing fiber clumping.

[0056] The nonwoven fabric may be composed of the water-repellent cellulosic fibers and the hydrophilic cellulosic fibers, and may also contain heat-fusible fibers, hydrophobic fibers, and the like, as described below, in addition to the water-repellent cellulosic fibers and hydrophilic cellulosic fibers.

[0057] The nonwoven fabric may further contain heat-fusible fibers intended to be heat-fused in the nonwoven fabric. When the nonwoven fabric contains the heat-fusible fibers, and heat fusion between the heat-fusible fibers and the heat-fusible fibers, or between the heat-fusible fibers and cellulosic fibers (water-repellent cellulosic fibers and hydrophilic cellulosic fibers), the strength of the nonwoven fabric and, in turn, the wet strength of the wet wipes can be increased. When the heat-fusible fibers are heat-fused to each other, the strength of the nonwoven fabric and, in turn, the wet strength of the wet wipes can be further increased.

[0058] The heat-fusible fibers can be any of those used in the art, specifically, fibers containing a low-melting thermoplastic resin and a high-melting thermoplastic resin, and are preferably those containing a low-melting thermoplastic resin such as polyethylene resin or low-melting polypropylene on at least the surface to fuse the heat-fusible fibers together. Examples of the heat-fusible fibers include monocomponent fibers of polyethylene resin, monocomponent fibers of polypropylene resin, core-sheath type composite synthetic fibers having a polyethylene terephthalate resin core and a polyethylene resin sheath, core-sheath type composite synthetic fibers having a polypropylene resin core and a polyethylene resin sheath, core-sheath type composite synthetic fibers having a high-melting polypropylene resin core and a low-melting polypropylene resin sheath, side-by-side type composite synthetic fibers made of polyethylene terephthalate resin and polyethylene resin, and side-by-side type composite synthetic fibers made of polypropylene resin and polyethylene resin.

[0059] The heat-fusible fiber is preferably a biodegradable heat-fusible fiber, which makes the nonwoven fabric, and ultimately the wet wipes, more biodegradable. Examples of the low-melting-point thermoplastic resin constituting the biodegradable heat-fusible fiber include polybutylene succinate, poly(hydroxybutyrate / hydroxyhexanoate), polycaprolactone, poly(caprolactone / butylene succinate), poly(butylene succinate / adipate), poly(butylene succinate / carbonate), poly(butylene adipate / terephthalate), polyethylene succinate, and polylactic acid.

[0060] Examples of the high-melting thermoplastic resin that constitutes the biodegradable heat-fusible fiber include polylactic acid, polyhydroxybutyrate, polyglycolic acid, and cellulose acetate.

[0061] When the nonwoven fabric contains the thermally adhesive fibers, the nonwoven fabric preferably contains the thermally adhesive fibers in a proportion of more than 0 mass%, more preferably 2 mass% or more, and even more preferably 5 mass% or more. When the nonwoven fabric contains the thermally adhesive fibers, the nonwoven fabric preferably contains the thermally adhesive fibers in a proportion of 30 mass% or less, more preferably 20 mass% or less, and even more preferably 15 mass% or less. This allows wet wipes formed from the nonwoven fabric to have excellent wet strength.

[0062] The nonwoven fabric may further include hydrophobic fibers that are not intended to be heat-sealed in the nonwoven fabric. This allows wet wipes formed from the nonwoven fabric to have bulk, resistance to settling, etc. Examples of the hydrophobic fibers include those commonly used in the art, and synthetic fibers are preferred. Examples of the synthetic fibers include those containing a single component, such as a single fiber, and those containing multiple components, such as a composite fiber.

[0063] Examples of the above components include polyolefin-based polymers such as polyethylene and polypropylene; polyester-based polymers such as terephthalate-based polymers such as polyethylene terephthalate (PET), polybutylene terephthalate, and polypentylene terephthalate; polyamide-based polymers such as nylon 6 and nylon 6,6; acrylic-based polymers; polyacrylonitrile-based polymers; and modified products thereof.

[0064] When the nonwoven fabric contains the hydrophobic fibers, the nonwoven fabric preferably contains the hydrophobic fibers in a proportion of more than 0 mass%, more preferably 1 mass% or more, and even more preferably 2 mass% or more. When the nonwoven fabric contains the hydrophobic fibers, the nonwoven fabric preferably contains the hydrophobic fibers in a proportion of 50 mass% or less, more preferably 40 mass% or less, and even more preferably 35 mass% or less. This allows wet wipes formed from the nonwoven fabric to have bulk, resistance to settling, etc.

[0065] The nonwoven fabric preferably has a density of 20 g / m 2More preferably, 30 g / m 2 More preferably, 35 g / m 2 The nonwoven fabric preferably has a basis weight of 100 g / m or more. 2 Less than 90 g / m 2 More preferably 80 g / m or less 2 or less, and even more preferably 70 g / m 2 The nonwoven fabric has the following basis weight, which makes it easier to ensure that wet wipes made from the nonwoven fabric are easy to remove and have sufficient strength for wiping and other purposes.

[0066] The nonwoven fabric may have a layer structure, such as a two-layer structure, a three-layer structure, a four-layer structure, a five-layer structure, etc. (A structure of three or more layers may be hereinafter referred to as a "structure of three or more layers.") When the nonwoven fabric has a three-layer or more layer structure, the nonwoven fabric may be divided into a first surface layer and a second surface layer that form the surface of the nonwoven fabric, and one or more intermediate layers disposed between the first surface layer and the second surface layer.

[0067] When the nonwoven fabric has a three-layer or more structure, the water-repellent cellulosic fibers are preferably contained in at least one of the first and second surface layers, and more preferably in both the first and second surface layers. This prevents the wet wipe portions from sticking together and makes them easier to separate in wet wipes formed from the nonwoven fabric. Note that the intermediate layer may contain the water-repellent cellulosic fibers, but from the viewpoint of facilitating separation of adjacent wet wipe portions, the intermediate layer does not need to contain the water-repellent cellulosic fibers.

[0068] When the nonwoven fabric has a three-layer or more structure and further contains hydrophilic cellulosic fibers, the hydrophilic cellulosic fibers may be contained in any of the first surface layer, the intermediate layer, and the second surface layer, and preferably in all of the first surface layer, the intermediate layer, and the second surface layer, which makes it easier to sufficiently impregnate wet wipes made from the nonwoven fabric with a chemical solution.

[0069] When the nonwoven fabric has a three-layer or more structure and further contains thermally adhesive fibers, the thermally adhesive fibers can be contained in any of the first surface layer, the intermediate layer, and the second surface layer. The thermally adhesive fibers can be contained in at least the intermediate layer, or only the intermediate layer. This allows wet wipes formed from the nonwoven fabric to have excellent wet strength and to be less likely to feel stiff due to the thermally adhesive fibers. The thermally adhesive fibers can also be contained in the first surface layer and the second surface layer. This allows wet wipes formed from the nonwoven fabric to be less susceptible to deformation, such as deformation due to deformation or stretching, during wiping.

[0070] When the nonwoven fabric has a three-layer or more structure, the first and second surface layers are preferably each composed of cellulosic fibers. This makes it easier for the chemical solution to be retained in the first and second surface layers, and the wet wipes have excellent wiping properties. The cellulosic fibers include the water-repellent cellulosic fibers and, optionally, the hydrophilic cellulosic fibers.

[0071] When the nonwoven fabric has a three-layer or more structure, the middle layer may further contain pulp fibers, which reduces the amount of chemical solution on the surfaces of the wet wipe portions (the first and second surface layers), making it easier for the wet wipe portions to separate and not stick together.

[0072] The nonwoven fabric according to the present disclosure preferably has a water absorbency by the Klemm method of 60 mm or more, more preferably 65 mm or more, and even more preferably 70 mm or more. The nonwoven fabric according to the present disclosure also preferably has a water absorbency by the Klemm method of 110 mm or less, more preferably 105 mm or less, and even more preferably 100 mm or less. This makes it possible for wet wipes formed from the nonwoven fabric to be easily separated and less likely to stick together.

[0073] In this disclosure, the water absorbency by the Klemm method is measured in accordance with JIS P8141:2004, "Paper and cardboard - Water absorbency test method - Klemm method," with the following differences from JIS P8141:2004. - Two types of test specimens are used: one with the machine direction during nonwoven fabric production as the longitudinal direction (hereinafter referred to as "MD test specimen"), and one with the machine direction during nonwoven fabric production as the transverse direction (hereinafter referred to as "CD test specimen"). - The test specimen dimensions are changed from "15±1 mm width" to "25±1 mm width." - The height to which water rises is changed from "10 minutes±10 seconds" to "5 minutes±10 seconds." - The average value of the Klemm water absorbency of the MD test specimen and the Klemm water absorbency of the CD test specimen is used as the Klemm water absorbency.

[0074] The nonwoven fabric according to the present disclosure preferably has a water absorption of 13.5 g / g or more, more preferably 14.0 g / g or more, even more preferably 14.5 g / g or more, and even more preferably 15.0 g / g or more. The nonwoven fabric according to the present disclosure also preferably has a water absorption of 20.0 g / g or less, more preferably 19.0 g / g or less, even more preferably 18.0 g / g or less, and even more preferably 17.0 g / g or less. This allows wet wipes formed from the nonwoven fabric to have excellent wiping properties.

[0075] The nonwoven fabric according to the present disclosure preferably has a water retention capacity of 10.0 g / g or more, more preferably 10.3 g / g or more, even more preferably 10.6 g / g or more, and even more preferably 10.9 g / g or more. The nonwoven fabric according to the present disclosure also preferably has a water retention capacity of 16.0 g / g or less, more preferably 15.0 g / g or less, even more preferably 14.0 g / g or less, and even more preferably 13.0 g / g or less. This provides wet wipes formed from the nonwoven fabric with excellent wiping properties.

[0076] In the present disclosure, water absorption and water retention are measured as follows: (1) A nonwoven fabric is cut into a size of 60 mm x 140 mm (the conveying direction during manufacturing x the direction perpendicular to the conveying direction) to prepare a sample, and the mass of the sample, m0 (g), is measured. (2) Ion-exchanged water is placed in a plastic container, and the sample is placed on a wire mesh whose mass, m1 (g), has been measured, and the sample, along with the wire mesh, is immersed in the ion-exchanged water. (3) After 3 minutes of immersion, the sample, along with the wire mesh, is removed from the ion-exchanged water and left to stand for 5 minutes to drain. (4) After leaving it to stand for 5 minutes, the total mass of the sample and the wire mesh, m2 (g), is measured. (5) The sample containing the ion-exchanged water is held with tweezers without applying pressure, and the sample is placed on a metal base measuring 60 mm x 140 mm or larger, taking care not to wrinkle it.

[0077] (6) Place an 840g weight on the sample so that the load is evenly distributed over the entire sample, and leave it to stand for 3 minutes. (7) After leaving it to stand for 3 minutes, measure the mass of the sample: m3 (g). (8) Calculate the water absorption: A (g / g) using the following formula: A (g / g) = (m2 - m1 - m0) / m0. (9) Calculate the water retention: R (g / g) using the following formula: R (g / g) = (m3 - m0) / m0. The water absorption and water retention are measured in a constant temperature room at 25°C ± 5°C.

[0078] As the nonwoven fabric, any nonwoven fabric (e.g., spunlace nonwoven fabric, air-through nonwoven fabric, spunbond nonwoven fabric, point-bond nonwoven fabric, etc.) produced by a known method such as a dry method, a wet method, a water jet method, a spunbond method, an air-laid method, a needle punch method, or a felt method can be used, and a spunlace nonwoven fabric having high wet strength is preferred.

[0079] The nonwoven fabric can be produced by a method known in the art. When the nonwoven fabric is a spunlace nonwoven fabric, for example, a dry spunlace nonwoven fabric, it can be produced, for example, by a dry spunlace method in which a single-layer or multi-layer web constituting the nonwoven fabric, formed by a dry process, is placed on a support and a high-pressure water stream is sprayed onto the web from a nozzle. Furthermore, when the nonwoven fabric contains heat-fusible fibers, the high-pressure water stream may be sprayed onto the web, and then the web (nonwoven fabric) may be heated to a temperature equal to or higher than the melting point of the low-melting thermoplastic resin constituting the heat-fusible fibers to heat-fusible the heat-fusible fibers.

[0080] [Wet wipes and wet wipes packaging] The wet wipes according to the present disclosure include a nonwoven fabric sheet made of the nonwoven fabric described above and a medicinal solution. The nonwoven fabric sheet is formed by cutting the nonwoven fabric described above to a desired size.

[0081] The chemical solution can be any solution commonly used in the art. Examples of the chemical solution include antibacterial agents, surfactants, water, and hydrophilic organic solvents (e.g., ethanol). In the wet wipes, the proportion of the chemical solution impregnated into the nonwoven fabric (impregnation rate) can be any proportion commonly used in the art. The impregnation rate (mass%) [= 100 × (mass of chemical solution) / (mass of nonwoven fabric)] is, for example, 100 mass% or more, more preferably 200 mass% or more, and even more preferably 250 mass% or more. The chemical solution proportion (impregnation rate) is preferably 700 mass% or less, more preferably 600 mass% or less, even more preferably 550 mass% or less, and even more preferably 500 mass% or less.

[0082] The wet wipes packaging includes the wet wipes and a packaging body, and the wet wipes are stored in the packaging body. Examples of the packaging body include a packaging sheet, a packaging container, etc. When the packaging body is a packaging sheet, the wet wipes packaging contains one or more wet wipes stored in the packaging sheet. When the packaging contains one wet wipe, the wet wipe is folded. When the packaging contains multiple wet wipes, the multiple wet wipes may or may not be folded.

[0083] In addition, when the package body is a packaging container, in the wet wipes package, a plurality of wet wipes are stored in the packaging container. The packaging container may have a top portion having an opening and a bottom portion, and the plurality of wet wipes may be stacked in a direction from the bottom portion to the top portion.

[0084] Furthermore, among the plurality of wet wipes, a portion of the bottom-side wet wipe located on the bottom side and a portion of the top-side wet wipe adjacent to the bottom-side wet wipe on the top side can be arranged so as to overlap each other, with the portion of the bottom-side wet wipe located closer to the top than the portion of the top-side wet wipe.

[0085] Fig. 1 is a perspective view of a wet wipes package 1 according to one embodiment of the present disclosure (hereinafter referred to as "first embodiment"), and Fig. 2 is an end view of the wet wipes package 1 taken along the line II-II shown in Fig. 1. The wet wipes package 1 shown in Fig. 1 is a pop-up type wet wipes package, in which a plurality of wet wipes (not shown) are stored so as to be sequentially removable inside a package body 3 having a top T with an opening 5 and a bottom B. The package body 3 has a sealant 7 that covers the opening 5.

[0086] The package body 3 is bag-shaped, and when the opening 5 is sealed with the sealant 7, the wet wipes inside the package body 3 can be sealed tightly, thereby suppressing evaporation of the medication. Each wet wipe can be removed through the opening 5. The sealant 7 has an adhesive applied to the surface that comes into contact with the package body 3 so that the wet wipes inside the package body 3 can be repeatedly sealed.

[0087] 2, inside the package body 3, a plurality of wet wipes 9 are stacked in a direction from the top T to the bottom B. Each of the plurality of wet wipes 9 has a folded structure that is folded outward in three (approximately Z-shaped) with a first fold line and a second fold line. The plurality of wet wipes 9 are stacked so that adjacent wet wipes 9 in the thickness direction (the direction from the top T to the bottom B) face the same direction (so that the first fold lines overlap each other in the thickness direction, and so that the second fold lines overlap each other in the thickness direction).

[0088] 3 is a diagram illustrating a plurality of wet wipes 9 contained in the wet wipes package 1 shown in FIG. 2. The wet wipes 9', 9", and 9'" are stacked in order from the top T to the bottom B. The wet wipes 9' and 9" overlap each other such that the top end 9"T of the wet wipe 9" (bottom wet wipe) located on the bottom B side and the bottom end 9'B of the wet wipe 9' (top wet wipe) adjacent to it on the top T side are positioned closer to the top T than the bottom end 9'B of the wet wipe 9' (top wet wipe).

[0089] Similarly, in Figure 3, the relationship between the wet wipes 9'' and 9''' is such that the top end 9'''T of the wet wipe 9''' (bottom wet wipe) located on the bottom B side and the bottom end 9''B of the wet wipe 9'' (top wet wipe) adjacent to it on the top T side overlap each other so that the top end 9'''T of the wet wipe 9''' (bottom wet wipe) is located closer to the top T than the bottom end 9''B of the wet wipe 9'' (top wet wipe).

[0090] By stacking multiple wet wipes 9 as shown in Figures 2 and 3, when the wet wipe 9' is removed, a portion of the wet wipe 9'' (mainly 9''T) is pulled out and protrudes from the packaging body 3, making it easier to remove the wet wipe 9'' for the next use.

[0091] Furthermore, if the bottom end 9'B of the wet wipes 9' and the top end 9''T of the wet wipes 9'' are connected by a water film of chemical solution formed between the wet wipes, when the wet wipes 9' are removed, there is a tendency for the entire wet wipes 9'' to be removed together, resulting in multiple wipe removal.In the wet wipes package 1 of the first embodiment, the wet wipes 9 are specific wet wipes, so they are excellent in terms of being able to be removed one by one.

[0092] 4 is an end view of a wet wipes package 1 according to another embodiment of the present disclosure (hereinafter referred to as the "second embodiment"), corresponding to the end view taken along line II-II in FIG. 1. In FIG. 4, each of the plurality of wet wipes 9 has a four-fold (approximately Σ-shaped) structure folded along three fold lines. The plurality of wet wipes 9 are stacked such that the Σ-shaped portions of adjacent wet wipes 9 in the thickness direction (direction from the top T to the bottom B) face in opposite directions.

[0093] In the wet wipes package 1 according to the second embodiment, as in the first embodiment, the top end (not shown) of the bottom wet wipe (not shown) located on the bottom side and the bottom end (not shown) of the top wet wipe (not shown) adjacent to the top side overlap each other so that the top end of the bottom wet wipe is located closer to the top than the bottom end of the top wet wipe. In the wet wipes package 1 according to the second embodiment, the wet wipes 9 are specific wet wipes, so that the wet wipes can be easily removed one by one.

[0094] The present disclosure will be described below using examples, but the present disclosure is not limited to these examples. [Production Example 1] Nonwoven fabric No. 1 was formed by a dry spunlace method, having a first surface layer, a first intermediate layer, a second intermediate layer, and a second surface layer, in that order. Each of the first surface layer and the second surface layer contained 30% by mass of water-repellent rayon fiber (Ecorepellent, manufactured by Daiwabo Rayon Co., Ltd., fineness: 1.7 dtex, average fiber length: 40 mm) and 70% by mass of hydrophilic rayon fiber (Corona, manufactured by Daiwabo Rayon Co., Ltd., fineness: 1.44 dtex, average fiber length: 44 mm).

[0095] The first intermediate layer contained 85% by mass of pulp fiber (softwood pulp fiber) and 15% by mass of heat-fusible fiber (NBF(KK)-PL, manufactured by Daiwabo Co., Ltd., a composite fiber with a polylactic acid core and a polybutylene succinate sheath, fineness: 2.40 dtex, average fiber length: 5.0 mm). The second intermediate layer contained 100% by mass of hydrophilic rayon fiber (Corona, manufactured by Daiwabo Rayon Co., Ltd., fineness: 1.44 dtex, average fiber length: 44 mm).

[0096] Nonwoven fabric No. 1 was cut to a size of 200 × 140 mm (removal direction × width direction), and as shown in the second embodiment, 50 sheets of the cut nonwoven fabric No. 1 were stacked together, the stack of 50 sheets was packaged in a package body, and then the package body was filled with 300% by mass of a chemical solution of the 50 sheets of the stack, thereby forming wet wipes package No. 1.

[0097] [Production Example 2] Nonwoven fabric No. 2 and wet wipes package No. 2 were formed in the same manner as in Production Example 1, except that the compositions of the first surface layer and the second surface layer were changed as shown in Table 1. [Production Example 3] Nonwoven fabric No. 3 and wet wipes package No. 3 were formed in the same manner as in Production Example 1, except that the compositions of the first surface layer and the second surface layer were changed as shown in Table 1.

[0098] [Reference Production Example 1] Nonwoven fabric No. 4 and wet wipes package No. 4 were formed in the same manner as Production Example 1, except that the compositions of the first surface layer and the second surface layer were changed as shown in Table 1. [Comparative Production Example 1] Nonwoven fabric No. 5 and wet wipes package No. 5 were formed in the same manner as Production Example 1, except that the compositions of the first surface layer and the second surface layer were changed as shown in Table 2, specifically, that the "water-repellent rayon fiber" in the first surface layer and the second surface layer was changed to "hydrophobic fiber (polyethylene terephthalate fiber, fineness: 1.45 dtex, average fiber length: 38 mm)."

[0099]

[0100]

[0101] [Examples 1 to 3, and Comparative Examples 1 and 2] [Water Absorbency by Klemm Method] For Nonwoven Fabrics No. 1 to No. 5, the water absorbency, water absorption amount, and water retention amount were measured by the Klemm method according to the methods described herein. The results are shown in Table 3.

[0102] The multiple-sheet take-out ability and take-out height were evaluated for each of Wet Wipes Package No. 1 to Wet Wipes Package No. 5. The test methods are as follows. The results are shown in Table 3.

[0103] [Multiple-piece removal] Wet wipes are removed one by one from the package. When the nth wet wipe (1, 2, ..., n, ..., 50 from the top) is removed, the number of wet wipes (wet wipes indirectly removed "entirely") that are pulled along with the nth wet wipe (the wet wipe removed directly) and removed in its entirety is counted.

[0104] For example, when the nth wet wipe is removed, if the (n+1)th wet wipe below it is pulled by the nth wet wipe and removed in its entirety, the wet wipe that is indirectly removed "in its entirety" is counted as one wet wipe.

[0105] Furthermore, when the nth wet wipe is removed, if the (n+1)th wet wipe one sheet below is pulled by the nth wet wipe and removed in its entirety, and if the (n+2)th wet wipe two sheets below is pulled by the (n+1)th wet wipe and removed in its entirety, the wet wipes indirectly removed "in their entirety" are counted as 2. The experiment continues until all 50 wet wipes have been removed, and the total number of wet wipes indirectly removed "in their entirety": m is counted and taken as the multiple-wipe removal capability (sheets).

[0106] [Removal height] Wet wipes are removed one by one from the package, and when the nth wet wipe (1, 2, ..., n, ..., 50 from the top) is removed, the removed length (length from the edge of the wet wipe to the opening) of the wet wipe (wet wipe "partially" removed) that is pulled together with the nth wet wipe (wet wipe removed directly) is measured, and the total average is taken as the removal height. Note that when measuring the removal height, the wet wipe "wholly" removed indirectly is ignored.

[0107]

[0108] 1 Wet wipes packaging 3 Packaging body 5 Opening 7 Sealing material 9 Wet wipes

Claims

1. A nonwoven fabric for wet wipes, comprising water-repellent cellulosic fibers.

2. The nonwoven fabric according to claim 1, wherein the nonwoven fabric has a water absorbency of 60 to 110 mm according to the Klemm method.

3. The nonwoven fabric according to claim 1 or 2, wherein the nonwoven fabric contains 10 to 35 mass % of the water-repellent cellulosic fibers.

4. The nonwoven fabric according to any one of claims 1 to 3, wherein the water-repellent cellulosic fibers have a water swelling degree of 10 to 80 mass %.

5. The nonwoven fabric according to any one of claims 1 to 4, comprising a first surface layer and a second surface layer constituting the surface of the nonwoven fabric, and an intermediate layer disposed between the first surface layer and the second surface layer, each of the first surface layer and the second surface layer containing the water-repellent cellulosic fiber, and the intermediate layer containing heat-fusible fiber.

6. The nonwoven fabric according to claim 5, wherein the heat-fusible fibers include biodegradable heat-fusible fibers.

7. The nonwoven fabric according to claim 5 or 6, wherein each of the first surface layer and the second surface layer is composed of cellulosic fibers.

8. The nonwoven fabric according to any one of claims 5 to 7, wherein the intermediate layer further contains pulp fibers.

9. A wet wipe comprising a nonwoven fabric sheet made of the nonwoven fabric according to any one of claims 1 to 8 and a medicinal solution.

10. A wet wipes package in which a plurality of wet wipes are stored inside a packaging body having a top with an opening and a bottom, wherein at least a portion of the plurality of wet wipes are composed of the wet wipes described in claim 9, and the plurality of wet wipes are stacked in a direction from the bottom to the top.

11. A wet wipes package as described in claim 10, wherein the multiple wet wipes are arranged so that the top end of a bottom wet wipe located on the bottom side and the bottom end of a top wet wipe adjacent to the top side thereof overlap each other, such that the top end of the bottom wet wipe is located closer to the top than the bottom end of the top wet wipe.

12. Use of water-repellent cellulosic fibers to control the removability of wet wipes.

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