Non-woven fabric, and absorbent article and cleaning wiper using same

Abstract

The present invention provides a non-woven fabric having bulkiness and flexibility. The non-woven fabric (10) is obtained by laminating and integrating a first fiber layer (20) and a second fiber layer, and the first fiber layer (20) comprises first adhesive composite fibers and non-adhesive fibers obtained using at least two kinds of resin components having different melting points. And a second fiber layer containing a second adhesive composite fiber obtained using at least two resin components having different melting points, the non-woven fabric being characterized in that the fiber density of the second fiber layer is 2.0-10 times the fiber density of the first fiber layer.

Description

Technical Field

[0001] The present invention relates to a non-woven fabric, an absorbent article using the same, and a cleaning wipe. Background Art

[0002] Non-woven fabrics having bulkiness and softness are used for various purposes such as sanitary products such as disposable diapers, cleaning wipes, toiletries, and pet supplies.

[0003] As a method for improving the softness of a non-woven fabric, it is known to use fibers having a small fiber diameter. On the other hand, as a method for improving the bulkiness of a non-woven fabric, methods such as changing the cross-sectional shape of the fiber, or imparting crimps to the fiber to give the fiber a three-dimensional structure, or mixing fibers having a large fiber diameter or natural fibers such as cellulose fibers to form a fiber mass to improve the resilience are known.

[0004] For example, in Patent Document 1, as a non-woven fabric having bulkiness and softness, a non-woven fabric containing a heat-bondable composite fiber is disclosed. The heat-bondable composite fiber has a structure in which two resin components having different melting points are used in a side-by-side type or an eccentric sheath-core type, has a crimp elastic coefficient of 85% to 100%, and a fineness of 0.9 dtex (decitex) to 8.0 dtex.

[0005] In addition, Patent Document 2 discloses a non-woven fabric for an absorbent article, which is a non-woven fabric including a first fiber layer and a second fiber layer laminated on the first fiber layer. The first fiber layer contains a first core-sheath type composite fiber, the second fiber layer contains a second core-sheath type composite fiber and a non-bonding fiber (cellulose-based fiber), the fineness of the first core-sheath type composite fiber is smaller than that of the second core-sheath type composite fiber, and in the second fiber layer, the cellulose-based fiber is contained in a proportion of 5% by mass to 40% by mass based on the total mass of the second fiber layer.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Laid-Open No. 2014-234559

[0009] Patent Document 2: Japanese Patent Laid-Open No. 2020-171688 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] In recent years, there has been a demand for further improvement in the functions and performances of various products, and the same applies to the nonwoven fabrics that make up them. For example, there is a demand for a nonwoven fabric that has good scraping properties for foreign substances and the like (that is, it is easy to take in foreign substances and the like, and has good retention of the taken-in foreign substances), and has a strength that does not cause problems when processed into products such as sanitary products or cleaning wipes.

[0012] The nonwoven fabric of Patent Document 1 is composed of thermally adhesive composite fibers having a cross-sectional shape of a side-by-side or eccentric structure. Since the fibers are fused to each other, the shape of the voids in the nonwoven fabric changes with the deformation of the fibers, but there is no large deformation. Therefore, when the surface of the nonwoven fabric comes into contact with foreign substances and the like, if the foreign substances are too large relative to the voids of the nonwoven fabric, they cannot be taken in. On the other hand, when obtaining a bulky nonwoven fabric, there is a tendency for the strength to decrease.

[0013] The nonwoven fabric of Patent Document 2 has: a first fiber layer containing first core-sheath type composite fibers, and a second fiber layer obtained by mixing second core-sheath type composite fibers and cellulose-based fibers. However, the nonwoven fabric of Patent Document 2 is a nonwoven fabric that uses the second fiber layer containing cellulose-based fibers to improve the absorbency of moisture and the like. In particular, when a fluid containing moisture and oil such as soft feces oozes back from the absorbent body, it is difficult for the soft feces and the like to ooze back to the surface of the first fiber layer. That is, the nonwoven fabric of Patent Document 2 is a nonwoven fabric that brings the first fiber layer into contact with an object such as the skin. Therefore, in the first fiber layer of the nonwoven fabric of Patent Document 2, the scraping properties for foreign substances and the like are not sufficient.

[0014] The present invention has been studied and developed in view of such circumstances, and an object thereof is to provide a nonwoven fabric having good softness and bulkiness and satisfying scraping properties.

[0015] Technical means for solving the problem

[0016] The present inventors have conducted in-depth research and found that by laminating and integrating a first fiber layer in which fibers that contribute to adhesion and fibers that do not contribute to adhesion are mixed, and a second fiber layer containing fibers having a smaller fiber diameter than the fibers of the first fiber layer, and providing a fiber density difference between the first fiber layer and the second fiber layer, a nonwoven fabric having both softness and bulkiness and high scraping properties for foreign substances and the like can be obtained, and thus the present invention has been completed.

[0017] That is, the present invention is configured as follows.

[0018] [1]A non-woven fabric, characterized in that it is formed by laminating and integrating a first fiber layer and a second fiber layer. The first fiber layer contains first adhesive composite fibers and non-adhesive fibers obtained using at least two resin components with different melting points. The second fiber layer contains second adhesive composite fibers obtained using at least two resin components with different melting points. The fiber density of the second fiber layer is 2.0 times or more and 10 times or less relative to the fiber density of the first fiber layer.

[0019] [2]The non-woven fabric according to [1], wherein the unit area weight of the second fiber layer is 0.2 times or more and 1.5 times or less of the unit area weight of the first fiber layer.

[0020] [3]The non-woven fabric according to [1], wherein the fineness of the first adhesive composite fiber is 1.1 times or more and 25 times or less of the fineness of the second adhesive composite fiber.

[0021] [4]The non-woven fabric according to [1], wherein the non-adhesive fiber is a polyester-based single fiber with a fineness of 2.0 dtex or more and 15.0 dtex or less.

[0022] [5]An absorbent article using the non-woven fabric according to [1]. In the absorbent article, the first fiber layer is disposed on the side in contact with the skin.

[0023] [6]A cleaning wipe using the non-woven fabric according to [1]. In the cleaning wipe, the first fiber layer is configured to be the scraping surface.

[0024] Effects of the Invention

[0025] The non-woven fabric of the present invention has high scraping property for foreign substances while maintaining high softness and bulkiness. In addition, since the non-woven fabric of the present invention has a specified strength, problems are not likely to occur in the production of products such as sanitary products or cleaning wipes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view showing an embodiment of the non-woven fabric of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, the details of the present invention will be described using embodiments, but the embodiments do not limit the present invention.

[0028] [Non-woven fabric 10]

[0029] Figure 1 ​The non-woven fabric 10 is formed by laminating and integrating a first fiber layer 20 and a second fiber layer 30. The first fiber layer 20 includes first adhesive composite fibers and non-adhesive fibers obtained using at least two resin components with different melting points. The second fiber layer 30 includes second adhesive composite fibers obtained using at least two resin components with different melting points. The fiber density of the second fiber layer 30 is 2.0 times or more and 10 times or less relative to the fiber density of the first fiber layer 20.

[0030] The non-woven fabric 10 configured in this way has high softness, bulkiness, and scraping property because it includes the first fiber layer 20 in which adhesive points and non-adhesive points are mixed. That is, when in contact with foreign substances or the like, the non-adhesive fibers in the first fiber layer 20 can move. Therefore, the void shape of the first fiber layer 20 deforms according to the shape or size of the foreign substances or the like, and it is easy to take in foreign substances or the like. Furthermore, since the non-adhesive fibers entangle the taken-in foreign substances, the retention property of the foreign substances is also high.

[0031] In addition, since the non-woven fabric 10 includes non-adhesive fibers in the first fiber layer 20, it is soft and easy to fuzz. Therefore, it can also be preferably used as a fuzzed non-woven fabric.

[0032] The non-woven fabric 10 is a non-woven fabric formed by integrally laminating the first fiber layer 20 and the second fiber layer 30. Preferably, the fiber aggregate of the first fiber layer 20 and the fiber aggregate of the second fiber layer are overlapped, and hot air is passed through to thermally melt the adhesive component to form a breathable non-woven fabric with adhesive points.

[0033] The thickness of the non-woven fabric 10 can be appropriately selected according to the use and is not particularly limited. For example, it is 2.0 mm or more, preferably 3.0 mm or more, particularly preferably 3.5 mm or more, and 20 mm or less, preferably 15 mm or less, particularly preferably 10 mm or less.

[0034] The weight per unit area of the non-woven fabric 10 is 10 g / m 2 or more, preferably 20 g / m 2 or more, particularly preferably 25 g / m 2 or more, most preferably 30 g / m 2 or more, and 100 g / m 2 or less, preferably 60 g / m 2 or less, particularly preferably 50 g / m 2 or less.

[0035] In addition, the specific volume (thickness / weight per unit area) of the non-woven fabric 10 is 90 cm 3 / g or more, preferably 95 cm 3 / g or more, particularly preferably 100 cm 3 / g or more, most preferably 110 cm3 / g or more, and 300 cm 3 / g or less, preferably 250 cm 3 / g or less, particularly preferably 200 cm 3 / g or less, most preferably 150 cm 3 / g or less.

[0036] The fiber density of the second fiber layer 30 (the number of fibers per unit area of the cross-section) is 2.0 times or more, preferably 2.2 times or more, particularly preferably 2.3 times or more, most preferably 2.4 times or more, and 10 times or less, preferably 8 times or less, particularly preferably 7 times or less, relative to the fiber density of the first fiber layer 20 (the number of fibers per unit area of the cross-section).

[0037] [First fiber layer 20]

[0038] The first fiber layer 20 is formed by subjecting a fiber aggregate obtained by mixing a first adhesive composite fiber that adheres to adjacent fibers and a non-adhesive fiber that does not contribute to adhesion to heat treatment, causing the low-melting component of the first adhesive composite fiber to thermally melt, and forming a layer with adhesion points. Particularly preferably, a layer with adhesion points is formed by passing hot air to thermally melt the low-melting component of the first adhesive composite fiber. That is, adhesion points and non-adhesion points coexist at the contact points between the fibers of the first fiber layer 20.

[0039] The fiber density of the first fiber layer (the number of fibers per unit area of the cross-section (the sum of the first adhesive composite fiber and the non-adhesive fiber)) is 5 fibers / mm 2 or more, preferably 10 fibers / mm 2 or more, more preferably 12 fibers / mm 2 or more, particularly preferably 15 fibers / mm 2 or more, and 30 fibers / mm 2 or less, preferably 25 fibers / mm 2 or less, particularly preferably 20 fibers / mm 2 or less. If it is 5 fibers / mm 2 or more, the fibers can be wound around the foreign matter taken in. If it is 30 fibers / mm 2 or less, the bulkiness of the first fiber layer 10 can be ensured.

[0040] The thickness of the first fiber layer 20 is not particularly limited. For example, it is 60% or more, preferably 70% or more, particularly preferably 80% or more, and 95% or less, preferably 90% or less, particularly preferably 85% or less, relative to the overall thickness of the non-woven fabric 10. The thickness can be selected according to the foreign matter incorporated into the first fiber layer. As a specific thickness, for example, it is 2.5 mm or more, preferably 3.0 mm or more, particularly preferably 3.3 mm or more, and 15 mm or less, preferably 12 mm or less, particularly preferably 9 mm or less.

[0041] The basis weight of the first fiber layer 20 is 15 g / m 2 or more, preferably 16 g / m 2 or more, particularly preferably 17 g / m 2 or more, and 50 g / m 2 or less, preferably 40 g / m 2 or less, particularly preferably 30 g / m 2 or less, most preferably 25 g / m 2 or less. If the basis weight of the first fiber layer 20 is 15 g / m 2 or more, the retention of the incorporated foreign matter is good. On the other hand, if it is 50 g / m 2 or less, the voids in the first fiber layer 10 can be sufficiently ensured, and the ease of incorporation of foreign matter is improved.

[0042] The specific volume (thickness / basis weight) of the first fiber layer 20 is 80 cm 3 / g or more, preferably 100 cm 3 / g or more, more preferably 120 cm 3 / g or more, particularly preferably 140 cm 3 / g or more, most preferably 160 cm 3 / g or more, and 260 cm 3 / g or less, preferably 220 cm 3 / g or less, particularly preferably 200 cm 3 / g or less. If it is 80 cm 3 / g or more, the incorporated foreign matter can be retained. If it is 260 cm 3 / g or less, the voids in the first fiber layer 10 can be sufficiently ensured, and the ease of incorporation of foreign matter is improved.

[0043] The proportion of the first adhesive composite fibers in the first fiber layer 20 is 20% by weight or more, preferably 30% by weight or more, particularly preferably 40% by weight or more, and 80% by weight or less, preferably 70% by weight or less, particularly preferably 60% by weight or less, most preferably 55% by weight or less.

[0044] The proportion of non - adhesive fibers in the first fiber layer 20 is 20% by weight or more, preferably 30% by weight or more, particularly preferably 40% by weight or more, most preferably 45% by weight or more, and is 80% by weight or less, preferably 70% by weight or less, particularly preferably 60% by weight or less.

[0045] In the first fiber layer 20, by increasing the proportion of non - adhesive fibers, bulkiness and softness can be obtained, and the scraping property of foreign substances is also improved. On the other hand, if the proportion of non - adhesive fibers is decreased, the durability of the first fiber layer is improved.

[0046] [First adhesive composite fiber]

[0047] The first adhesive composite fiber is a fiber that contributes to the adhesion between fibers in the first fiber layer 20. The first adhesive composite fiber is obtained using at least two resin components with different melting points. As a combination of resin components, a combination of a resin component with a high melting point and a resin component with a melting point 15°C or more lower than the melting point of this resin component is preferred.

[0048] The resin component is not particularly limited, and examples include polyester - based resins or polyolefin - based resins. As polyester - based resins, examples include: polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polylactic acid, polybutylene succinate, polybutylene adipate terephthalate, and their copolymers, etc. As polyolefin - based resins, examples include polyethylene, polypropylene, and copolymers mainly composed of propylene, etc.

[0049] Moreover, as a combination of resin components (high - melting - point resin component / low - melting - point resin component), for example, combinations such as polyester - based resin / polyolefin - based resin, polyolefin - based resin / polyolefin - based resin, polyester - based resin / polyester - based resin can be mentioned. Particularly preferably, polyethylene terephthalate / polyethylene, polypropylene / polyethylene can be mentioned.

[0050] The fineness of the first adhesive composite fiber can be selected considering the bulkiness imparted to the first fiber layer, and is preferably greater than the fineness of the second adhesive composite fiber 30 of the second fiber layer. As the lower limit of the specific fineness, it is 2 dtex or more, preferably 3 dtex or more, particularly preferably 4 dtex or more. In addition, if the fineness is set below a fixed value, the hand feeling is good, so as the upper limit, it is 20 dtex or less, preferably 15 dtex or less, particularly preferably 10 dtex or less.

[0051] As the structure of the first adhesive composite fiber, examples include: concentric sheath-core type, eccentric sheath-core type, side-by-side type, radial type, etc. Particularly preferred is the sheath-core type in which the resin component with a low melting point is the sheath component and the resin component with a high melting point is the core component, and particularly preferred is the concentric sheath-core type.

[0052] When the first adhesive composite fiber is of the sheath-core type, the weight ratio of the sheath component (resin component with a low melting point) to the core component (resin component with a high melting point) (sheath:core) is 10:90 to 90:10, preferably 30:70 to 70:30, and particularly preferably 40:60 to 60:40.

[0053] [Non-adhesive fiber]

[0054] The non-adhesive fiber is a fiber that does not melt during the heat treatment (such as hot air) applied to the fiber aggregate of the first fiber layer 20. For example, a fiber in which the melting point, softening point, or decomposition point of the non-adhesive fiber is 15°C or more higher than the resin component with a lower melting point of the first adhesive composite fiber. That is, it is a fiber that does not contribute to the adhesion between the fibers in the first fiber layer 20 and imparts mobility to the fibers within the first fiber layer 20.

[0055] The fineness of the non-adhesive fiber is not particularly limited, it is 2 dtex or more, preferably 3 dtex or more, particularly preferably 4 dtex or more, and is 15 dtex or less, preferably 12 dtex or less, particularly preferably 10 dtex or less. In addition, the fineness of the non-adhesive fiber is 1 time or more, preferably 1.2 times or more, particularly preferably 1.3 times or more the fineness of the first adhesive composite fiber, and is 2 times or less the fineness of the first adhesive composite fiber. By setting it to be the fineness of the first adhesive composite fiber or more, the crossing of the first adhesive composite fibers in the first fiber layer 20 can be reduced.

[0056] Examples of the non-adhesive fiber include: natural fibers (such as wood fiber or cotton), regenerated fibers (such as rayon), semi-synthetic fibers (such as acetate), or chemical fibers, synthetic fibers (such as polypropylene, polyester, acrylic, nylon, vinyl chloride, etc.). Particularly preferred are fibers containing a single component of cotton, rayon, polypropylene-based resin, or polyester-based resin. As a fiber containing a single component of polyester-based resin, by using polyethylene terephthalate, bulkiness can be imparted to the first fiber layer 20, and softness (smoothness, hand feeling) can be imparted, so it is preferred.

[0057] [Second fiber layer 30]

[0058] The second fiber layer 30 is a layer formed by subjecting a fiber aggregate containing second adhesive composite fibers to a heat treatment (such as hot air) to thermally melt the component with a low melting point of the second adhesive composite fibers, thereby forming bonding points between the fibers. That is, in principle, the second fiber layer 30 uses the contact points between the fibers as the bonding points. Moreover, the second fiber layer 30 imparts strength to the nonwoven fabric 10.

[0059] The fiber density (number of fibers per unit area of the cross-section) of the second fiber layer 30 is 2 times or more and 10 times or less that of the first fiber layer 20. The difference in the specific fiber density is, for example, 20 fibers / mm 2 or more, preferably 30 fibers / mm 2 or more, more preferably 35 fibers / mm 2 or more, particularly preferably 40 fibers / mm 2 or more, most preferably 45 fibers / mm 2 or more, and 60 fibers / mm 2 or less, preferably 55 fibers / mm 2 or less, particularly preferably 50 fibers / mm 2 or less. If it is 20 fibers / mm 2 or more, the strength as a nonwoven fabric is ensured. If it is 60 fibers / mm 2 or less, the processability as a nonwoven fabric is ensured.

[0060] The thickness of the second fiber layer 30 is not particularly limited, but it is preferably thinner than the thickness of the first fiber layer 20. Thereby, the nonwoven fabric 10 can be made thinner. The thickness of the second fiber layer 30 is, for example, 5% or more, preferably 8% or more, more preferably 13% or more, particularly preferably 16% or more, most preferably 18% or more, and 40% or less, preferably 30% or less, particularly preferably 20% or less, relative to the overall thickness of the nonwoven fabric 10. As a specific thickness, for example, it is 0.1 mm or more, preferably 0.3 mm or more, particularly preferably 0.4 mm or more, and 2.0 mm or less, preferably 1.5 mm or less, particularly preferably 1.0 mm or less.

[0061] The weight per unit area of the second fiber layer 30 is 5 g / m 2 or more, preferably 8 g / m 2 or more, more preferably 11 g / m 2 or more, particularly preferably 14 g / m 2 or more, most preferably 17 g / m 2 or more, and 30 g / m 2 or less, preferably 25 g / m 2 or less, particularly preferably 20 g / m 2Hereinafter. In addition, the basis weight per unit area of the second fiber layer 30 is preferably the same as or smaller than that of the first fiber layer 20. Specifically, the basis weight per unit area of the second fiber layer 30 is 0.3 times or more, preferably 0.7 times or more, particularly preferably 0.8 times or more, and 1.5 times or less, preferably 1.3 times or less, particularly preferably 1.2 times or less, relative to the basis weight per unit area of the first fiber layer 30. In addition, the difference in basis weight per unit area between the first fiber layer 20 and the second fiber layer 30 is 0 g / m 2 ~40 g / m 2 ,preferably 0 g / m 2 ~30 g / m 2 ,more preferably 0 g / m 2 ~25 g / m 2 。

[0062] The specific volume (thickness / basis weight per unit area) of the second fiber layer 30 is specifically 20 cm 3 / g or more, preferably 25 cm 3 / g or more, more preferably 30 cm 3 / g or more, particularly preferably 35 cm 3 / g or more, most preferably 40 cm 3 / g or more, and 100 cm 3 / g or less, preferably 80 cm 3 / g or less, more preferably 70 cm 3 / g or less, particularly preferably 60 cm 3 / g or less, most preferably 50 cm 3 / g or less. If it is 20 cm 3 / g or more, the strength of the second fiber layer 30 can be improved. On the other hand, if it is 100 cm 3 / g or less, the processability as a non-woven fabric is ensured.

[0063] [Second Adhesive Composite Fiber]

[0064] The second adhesive composite fiber is obtained by using at least two resin components having different melting points. As a combination of resin components, a combination of a resin component having a high melting point and a resin component having a melting point 15°C or more lower than the melting point of this resin component is preferred.

[0065] There is no particular limitation on the resin component, and examples thereof include polyester resins and polyolefin resins. As polyester resins, examples include polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polylactic acid, polybutylene succinate, polybutylene adipate terephthalate, and copolymers thereof. As polyolefin resins, examples include polyethylene, polypropylene, and copolymers mainly composed of propylene.

[0066] Moreover, as a combination of resin components (a resin component with a high melting point / a resin component with a low melting point), for example, the following combinations can be cited: polyester resin / polyolefin resin, polyolefin resin / polyolefin resin, polyester resin / polyester resin. Particularly preferably, the combination of polyethylene terephthalate / polyethylene, polypropylene / polyethylene can be cited.

[0067] The fineness of the second adhesive composite fiber can be selected in consideration of thinning the second fiber layer and improving smoothness, and is preferably smaller than the fineness of the first adhesive composite fiber 20 of the first fiber layer. For example, the fineness of the first adhesive composite fiber is 1.1 times or more, preferably 1.5 times or more, particularly preferably 2 times or more, most preferably 2.5 times or more, and 25 times or less, preferably 15 times or less, particularly preferably 10 times or less of the fineness of the second adhesive composite fiber. The specific fineness of the second adhesive composite fiber is 0.5 dtex or more, preferably 1 dtex or more, particularly preferably 1.5 dtex or more, and 5 dtex or less, preferably 3 dtex or less, particularly preferably 2.5 dtex or less.

[0068] As the shape of the second adhesive composite fiber, the following shapes can be cited: concentric sheath-core type, eccentric sheath-core type, side-by-side type, radial type, etc. Particularly preferably, it is a sheath-core type with a resin component with a low melting point as the sheath component and a resin component with a high melting point as the core component, and particularly preferably a concentric sheath-core type.

[0069] When the second adhesive composite fiber is of the sheath-core type, the weight ratio of the sheath component (resin component with a low melting point) to the core component (resin component with a high melting point) (sheath: core) is 10:90 to 90:10, preferably 30:70 to 70:30, particularly preferably 40:60 to 50:50.

[0070] In addition, the sheath component of the second adhesive composite fiber is preferably set to a resin component having the same melting point as the sheath component of the first adhesive composite fiber or a melting point difference within 5 °C, more preferably set to the same as the sheath component of the first adhesive composite fiber. Particularly preferably, the combination of the resin components of the first adhesive composite fiber is the same as the combination of the resin components of the second adhesive composite fiber.

[0071] "Method for manufacturing non-woven fabric"

[0072] The non-woven fabric is a breathable non-woven fabric and can be manufactured by appropriately selecting known manufacturing methods and conditions for breathable non-woven fabrics.

[0073] For example, a first adhesive composite fiber having an appropriate fiber length and a non-adhesive composite fiber having an appropriate fiber length are mixed and fed to carding to obtain a carded fiber web (a fiber aggregate of the first fiber layer). On the other hand, a second adhesive composite fiber having an appropriate fiber length is fed to carding to obtain a carded fiber web (a fiber aggregate of the second fiber layer). The two carded fiber webs are laminated to form a laminated fiber web. The laminated fiber web is placed on a conveying support (a belt conveyor) and fed into a heat treatment device. In the heat treatment device, heating is performed to a temperature at which only the low-melting resin of the composite fiber melts, and the melted low-melting resins are bonded to each other (thermal bonding), whereby the intersections of the fibers are welded to manufacture a breathable nonwoven fabric having a three-dimensional structure. The heating method is not particularly limited. For example, hot air is blown onto the carded fiber web laminated from above the conveying support. In addition, in the case of producing a napped nonwoven fabric, a napping treatment is performed thereafter.

[0074] [Other Embodiments]

[0075] In Figure 1 the nonwoven fabric 10, the first fiber layer 20 and the second fiber layer 30 are adjacent to each other, but other fiber layers may be interposed and laminated and integrated within the scope that does not hinder the effects of the present invention.

[0076] Within the scope that does not hinder the effects of the present invention, Figure 1 the nonwoven fabric 10 of

[0077] For example, may also carry functional particles such as inorganic fine particles. The nonwoven fabric of the present invention is a nonwoven fabric having bulkiness and softness, and can be preferably used for absorbent articles such as diapers, sanitary napkins or incontinence pads, hygiene materials such as masks, gowns or surgical gowns, interior decoration materials such as wall sheets, window papers or floor materials, covering cloths, cleaning wipes or covers for domestic waste, toilet articles such as disposable toilets or toilet covers, pet supplies such as pet pads, pet diapers or pet towels, wiping materials, filters, cushioning materials, oil adsorption materials or adsorbents for ink cartridges, general medical materials, bedding materials, nursing supplies and other various fiber products that require bulkiness and softness. In particular, it can be preferably used for absorbent articles such as disposable diapers, cleaning wipes. When the nonwoven fabric of the present invention is used for the fiber products, it is preferably arranged such that the first fiber layer is exposed to the outside. That is, when used for absorbent articles, it is preferably arranged such that the first fiber layer is on the side in contact with the user's skin, and when used for cleaning wipes, it is preferably arranged such that the first fiber layer becomes the scraping surface.

[0078] Examples

[0079] Hereinafter, the present invention will be described in more detail by way of examples. However, these examples are for illustrative purposes only and do not limit the present invention.

[0080] The measurement methods and definitions of the physical property values used in the examples are as follows.

[0081] <Grammage>

[0082] Measure the weight of a sample cut into 100 mm × 100 mm, and convert the value per unit area to the grammage of the non-woven fabric (g / m 2 ). The grammage is set as the average value when measured twice.

[0083] <Thickness and Fiber Density>

[0084] (1) Method for preparing the sample for observation

[0085] Heat the non-woven fabric sample in an oven at 80 °C for 5 minutes to reset the stress history of the non-woven fabric. Next, impregnate a non-woven fabric cut into 1 cm (in the flow direction of the non-woven fabric; MD direction) × 2 cm (in the width direction of the non-woven fabric; CD direction) with a photocurable resin (Star Drop [Soft], a UV-light emitting diode (UV-LED) resin manufactured by PADICO), and perform UV irradiation to harden the photocurable resin. Next, use a microtome (RM2265 manufactured by Leica) to cut the hardened sample so that the thickness in the MD direction is 10 μm, and obtain an observation sample of 10 μm (MD direction) × 2 cm (CD direction).

[0086] (2) Measurement of thickness and fiber density

[0087] Use a microscope (VHX-6000 manufactured by KEYENCE) and a polarizing plate to observe the microtome cut surface of the observation sample at 20 to 50 times magnification, and measure the thickness of the first fiber layer and the second fiber layer, and the number of fibers per unit area (fibers / mm 2 ). The thickness of each layer and the fiber density are set as the average value when measured twice.

[0088] <Specific Volume>

[0089] Use the values of grammage and thickness obtained by the above method to calculate the specific volume using the following formula. In addition, the larger the specific volume, the more bulky it is.

[0090] Specific volume (cm 3 / g) = Thickness (mm) ÷ Grammage (g / m 2 ) × 1000

[0091] <Fiber Density Ratio>

[0092] Using the value of the fiber density obtained by the said method, calculate the fiber density ratio using the following formula.

[0093] Fiber density ratio = Fiber density of the second fiber layer (number of fibers / mm 2 ) ÷ Fiber density of the first fiber layer (number of fibers / mm 2 )

[0094] <Scrapeability>

[0095] Prepare 10 pieces of shredder waste (about 1 cm × 1 mm), place a sample of non-woven fabric on it with the first fiber layer 20 on the lower side. Further, under the state of applying a load of 1 g / cm 2 , slide the sample left and right (5 cm) 10 times. Then, count the number of pieces of shredder waste attached to the first fiber layer 20 of the sample.

[0096] <Compression test WC>

[0097] Use the portable compressor "KES-G5" manufactured by Kato Tech Co., Ltd. for measurement. In the compression test, press the test non-woven fabric with a indenter having a terminal cross-sectional area of 2 cm 2 at a sensitivity of Sens2 and a measurement speed of 0.2 mm / sec until the rebound pressure reaches 50 gf / cm 2 , and measure the distance. Take the distance on the horizontal axis and the pressure on the vertical axis, and take the integral value (WC (gf·cm / cm 2 ) as the measurement value. In addition, the larger the measurement value, the higher the softness.

[0098] <Feeling evaluation>

[0099] Five panelists touch one side of the first fiber layer 20 of the non-woven fabric (sample) and answer either soft or hard. When 4 or more out of 5 people answer soft, it is set as ◎, when 3 people answer soft, it is set as 〇, when 3 people answer hard, it is set as △, and when 4 or more people answer hard, it is set as ×, and the evaluation is carried out in 4 stages.

[0100] "Example 1"

[0101] As the first adhesive composite fiber, prepare a concentric sheath-core type composite fiber with a fineness of 9.0 dtex, in which the sheath is high-density polyethylene and the core is polyethylene terephthalate, configured at a weight ratio (sheath: core) of 50:50.

[0102] As the non-adhesive fiber, prepare a fiber with a fineness of 9.0 dtex containing a single component of polyethylene terephthalate.

[0103] As the second adhesive composite fiber, a concentric sheath-core type composite fiber with a fineness of 1.7 dtex is prepared, where the sheath is high-density polyethylene and the core is polyethylene terephthalate, arranged at a weight ratio (sheath: core) of 40:60.

[0104] Next, a carded fiber web 1 is produced by mixing the first adhesive composite fiber and the non-adhesive fiber at a weight ratio of 30 / 70, and a carded fiber web 2 containing the second adhesive composite fiber. The carded fiber web 2 is laminated on the carded fiber web 1, and hot air at 130 °C and 0.9 m / sec is blown from above using a hot air circulation type hair dryer, thereby obtaining the non-woven fabric of Example 1.

[0105] "Example 2"

[0106] The fineness of the first adhesive composite fiber is set to 4.4 dtex, and the fineness of the non-adhesive fiber is set to 6.0 dtex. Otherwise, the non-woven fabric of Example 2 is obtained in the same manner as in Example 1.

[0107] "Example 3"

[0108] As the carded fiber web 1, the first adhesive fiber and the non-adhesive fiber are mixed at a weight ratio of 70 / 30. Otherwise, the non-woven fabric of Example 3 is obtained in the same manner as in Example 1.

[0109] "Example 4"

[0110] As the non-adhesive fiber, a fiber with a fineness of 5.6 dtex containing only rayon is used. Otherwise, the non-woven fabric is obtained in the same manner as in Example 2.

[0111] "Example 5"

[0112] As the carded fiber web 1, the first adhesive fiber and the non-adhesive fiber are mixed at a weight ratio of 50 / 50, and the unit area weight ratio of the carded fiber web 1 and the carded fiber web 2 is changed. Otherwise, the non-woven fabric is obtained in the same manner as in Example 2.

[0113] "Comparative Example 1"

[0114] As the carded fiber web 1, no non-adhesive fiber is used. Otherwise, the non-woven fabric of Comparative Example 1 is obtained in the same manner as in Example 1.

[0115] "Comparative Example 2"

[0116] As the carded fiber web 1, no non-adhesive fiber is used. Otherwise, the non-woven fabric of Comparative Example 2 is obtained in the same manner as in Example 2.

[0117] "Comparative Example 3"

[0118] The fineness of the first continuous composite fiber was set to 1.7 dtex, and the weight ratio of the sheath to the core (sheath:core) was set to 40:60. Otherwise, the nonwoven fabric of Comparative Example 3 was obtained in the same manner as in Example 5.

[0119] The physical properties and test results of the nonwoven fabrics of these Examples and Comparative Examples are shown in Table 1.

[0120] [Table 1]

[0121]

[0122] As shown in Table 1, in the nonwoven fabrics of Examples 1 to 5, the non-adhesive fibers were mixed with the first fiber layer, and the fiber density ratio of the first fiber layer 20 to the second fiber layer 30 was 2 times or more, so high scraping properties were obtained. In particular, in Comparative Example 3, the non-adhesive PET fibers were mixed with the first fiber layer, and the fiber density ratio was 1.0 times, so sufficient scraping properties could not be obtained. In addition, in Example 4 using rayon as the non-adhesive fiber, the specific volume of the first fiber layer was lower than that of the other examples, and the softness (compression test WC) was slightly lower than that of the other examples.

[0123] Industrial applicability

[0124] The nonwoven fabric of the present invention is a nonwoven fabric having bulkiness and softness, and can be preferably used for various fiber products requiring bulkiness and softness. In particular, it can be preferably used for absorbent articles such as disposable diapers and cleaning wipes.

[0125] 10: Nonwoven fabric

[0126] 20: First fiber layer

[0127] 30: Second fiber layer

Claims

1. A non-woven fabric, characterized in that it is formed by laminating and integrating a first fiber layer and a second fiber layer, the first fiber layer comprising first adhesive composite fibers and non-adhesive fibers obtained using at least two resin components having different melting points, the second fiber layer comprising second adhesive composite fibers obtained using at least two resin components having different melting points, the fiber density of the second fiber layer is 2.0 times or more and 10 times or less relative to the fiber density of the first fiber layer.

2. The non-woven fabric according to claim 1, wherein the basis weight per unit area of the second fiber layer is 0.2 times or more and 1.5 times or less the basis weight per unit area of the first fiber layer.

3. The non-woven fabric according to claim 1, wherein the fineness of the first adhesive composite fibers is 1.1 times or more and 25 times or less the fineness of the second adhesive composite fibers.

4. The non-woven fabric according to claim 1, wherein the non-adhesive fibers are polyester single fibers having a fineness of 2.0 dtex or more and 15.0 dtex or less.

5. An absorbent article using the non-woven fabric according to claim 1, in the absorbent article, the first fiber layer is disposed on the side in contact with the skin.

6. A cleaning wiper using the non-woven fabric according to claim 1, in the cleaning wiper, it is configured such that the first fiber layer becomes a scraping surface.

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