Nonwoven fabric and wiping sheet

Abstract

To provide a nonwoven fabric, which is excellent in wiping property and liquid holding property and hardly deformed by stress during wiping, and also to provide a wiping sheet using the nonwoven fabric.SOLUTION: A nonwoven fabric and a wiping sheet contain single fibers. The single fiber is a hollow fiber having an irregularly shaped cross section and has a triangular hollow part and protrusion part on an extended line of each side of the triangular shape on a transverse section of the single fiber. Single fiber fineness of the single fiber is 5.0 dtex or less. CV% of modified degree of the single fiber is 2.0 or less.SELECTED DRAWING: Figure 1A

Description

[Technical field]

[0001] The present invention relates to a nonwoven fabric and a wiping sheet. [Background technology]

[0002] 2. Description of the Related Art Nonwoven fabrics and woven fabrics made of synthetic fibers such as polyamide, polyester, polyolefin, and acrylic, and natural fibers such as pulp have been used as wiping sheets for removing dirt from a variety of items, including displays of personal computers (PCs), smartphones, and tablets, eyeglass lenses, acrylic panels for preventing splashes, and glass products.

[0003] These wiping sheets are used for the purpose of removing dirt from objects, so they need to have excellent wiping properties. In addition, in order to efficiently remove dirt to be wiped off, they are used impregnated with water, alcohol, or a chemical solution containing these depending on the application and the object to be wiped off (hereinafter, sometimes simply referred to as the object), so they need to have excellent liquid retention properties. Furthermore, from the viewpoint of retaining the impregnated chemical inside and maintaining wiping properties, they need to be resistant to deformation due to stress during wiping.

[0004] As a nonwoven fabric suitable for the above-mentioned wiping sheet, Patent Document 1 proposes a wiping sheet made of knitted fabric using microfibers, and Patent Document 2 proposes a wiping sheet including a single fiber in which the cross-sectional shape of the single fiber has a hollow core portion and fin portions radially protruding from the hollow core portion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 9-19393 [Patent Document 2] JP 2021-151340 A Summary of the Invention [Problem to be solved by the invention]

[0006] The wiping sheet disclosed in the above-mentioned Patent Document 1 is excellent in wiping off dirt adhering to the smooth surface of an object, but tends to be poor in wiping off dirt that has entered into minute recesses of the object. In general, wiping sheets use fibers to scrape off dirt adhering to minute recesses of the object and hold the dirt in the gaps between the fibers to wipe the dirt off the object, but the wiping sheet of Patent Document 1 uses microfibers with a round cross section and relatively large fineness, so the fibers have difficulty entering minute recesses and tend to have poor wiping properties.

[0007] On the other hand, the wiping sheet disclosed in the above-mentioned Patent Document 2 has a structure using a single fiber having a hollow core and fins protruding radially from the hollow core, so that the fins easily enter fine recesses and tend to have better wiping properties. Furthermore, the fins serve to reduce the contact surface between the fibers, resulting in a wiping sheet that is bulky and has excellent liquid retention. However, since the hollow core of the single fiber is round, the hollow part tends to be crushed by external stress and the single fiber tends to be easily deformed. Therefore, the nonwoven fabric made of the single fiber and the wiping sheet made of the nonwoven fabric tend to be easily deformed by the stress during wiping and tend to have poor chemical retention.

[0008] In view of the above problems, the present invention aims to provide a nonwoven fabric that is excellent in wiping ability and liquid retention and is resistant to deformation due to stress during wiping, and a wiping sheet using said nonwoven fabric. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides a nonwoven fabric having the following configuration, and a wiping sheet using the nonwoven fabric. (1) A nonwoven fabric containing a single fiber, the single fiber being a modified cross-section hollow fiber, the cross section of the single fiber having a triangular hollow portion and having protrusions on the extension lines of each side of the triangle, the single fiber having a single yarn fineness of 5.0 dtex or less, and the modified degree of the single fiber having a CV% of 2.0 or less. (2) The nonwoven fabric according to (1), wherein the hollow ratio of the single fiber is 20% or less and the degree of irregularity of the single fiber is 1.1 to 2.0. (3) A nonwoven fabric according to (1) and (2), further comprising cellulose pulp. (4) Weight per unit area is 10g / m 2 More than 120g / m 2 4. The nonwoven fabric according to claim 1, wherein the porosity is 70% or more and 95% or less. (5) A wiping sheet using the nonwoven fabric according to any one of (1) to (4). Effect of the Invention

[0010] The present invention provides a nonwoven fabric which is excellent in wiping ability and liquid retention and is resistant to deformation due to stress during wiping, and a wiping sheet using said nonwoven fabric. [Brief description of the drawings]

[0011] [Figure 1A] FIG. 2 is a schematic diagram showing an example of a cross-sectional structure of a modified cross-section hollow fiber contained in the nonwoven fabric of the present invention. [Figure 1B] FIG. 2 is a schematic diagram showing an example of a cross-sectional structure of a modified cross-section hollow fiber contained in the nonwoven fabric of the present invention. [Figure 1C] FIG. 2 is a schematic diagram showing an example of a cross-sectional structure of a modified cross-section hollow fiber contained in the nonwoven fabric of the present invention. [Figure 2A] FIG. 1 is a first schematic diagram of a glass plate on which lip balm is applied in the test method for the wiping ability test. [Figure 2B] FIG. 2 is a second schematic diagram of a glass plate on which lip balm is applied in the test method for the wiping ability test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The nonwoven fabric of the present invention contains monofilaments, the monofilaments being hollow fibers with modified cross sections, each of which has a triangular hollow portion in its cross section and has protrusions on extensions of each side of the triangle, the monofilaments having a single filament fineness of 5.0 dtex or less, and a CV% of the degree of deformation of the monofilaments being 2.0 or less.

[0013] The nonwoven fabric of the present invention has excellent wiping properties, bulkiness, and excellent liquid retention properties due to the inclusion of monofilaments having protrusions. In other words, the protrusions penetrate into minute recesses in the target object to scrape off dirt and reduce the contact surface area between the fibers, resulting in a nonwoven fabric that is bulky and has excellent liquid retention properties. In addition, the hollow portion is triangular, and the protrusions are provided on the extensions of each side of the triangle, resulting in a nonwoven fabric that is less likely to deform due to stress during wiping. Furthermore, this effect is remarkable when the single yarn fineness and irregularity of the monofilaments are within a specific range.

[0014] Furthermore, by using the above-mentioned nonwoven fabric, the wiping sheet of the present invention has excellent wiping properties and liquid retention properties, and is less likely to deform due to stress during wiping.

[0015] The present invention will now be described in detail.

[0016] <Single fiber: irregular cross-section hollow fiber> (1) Cross-sectional shape First, the cross-sectional shape of the monofilament contained in the nonwoven fabric of the present invention will be described. The monofilament is a modified cross-sectional hollow fiber, and its cross-sectional shape has a triangular hollow portion (hereinafter, sometimes simply referred to as a triangular hollow portion), and has protrusions on the extensions of each side of the triangle. Here, FIG. 1A is a schematic diagram of an example of the cross-sectional structure of the modified cross-sectional hollow fiber contained in the nonwoven fabric of the present invention. In these drawings, the monofilament 1 contained in the nonwoven fabric has a triangular hollow portion 2 and a protrusion portion 3. In addition, since the monofilament has a protrusion portion, the nonwoven fabric containing the monofilament has a superior wiping property compared to the nonwoven fabric containing a monofilament with a round cross section. In other words, the protrusion portion of the monofilament present on the surface of the nonwoven fabric enters the recess of the object and plays a role of scraping off dirt, and as a result, the nonwoven fabric has a superior wiping property. Furthermore, the presence of the protrusions reduces the frequency of contact between the single fibers, making it possible to ensure many gaps between the fibers inside the nonwoven fabric, and the nonwoven fabric using this single fiber becomes bulky and has excellent liquid retention properties.

[0017] Furthermore, since the hollow portion is triangular and the protrusions are located on the extension lines of each side of the triangular hollow, the monofilament is less likely to deform due to the stress applied when wiping. Therefore, a nonwoven fabric containing this monofilament is less likely to deform due to the stress applied when wiping, compared to a nonwoven fabric using monofilaments whose hollow portion is round or has a polygonal shape of four or more angles.

[0018] (2) Anomaly degree Next, the irregularity, which is an index of the length of the protrusions of the single fiber of the present invention, will be described. The irregularity of the single fiber of the present invention is preferably 1.1 to 2.0. Here, the irregularity will be described with reference to Figs. 1B and 1C. The radius of the circumscribed circle A passing through the three points (points g, h, and i) of the outermost protrusions protruding from the intersections (points d, e, and f) of the protrusions in Figs. 1B and 1C is taken as radius Ra. The radius of the circumscribed circle B passing through the three intersections (points d, e, and f) is taken as radius Rb. The irregularity is defined as irregularity = radius Ra / radius Rb. The irregularity of the single fiber in the present invention was measured by measuring the irregularities of the single fibers in the spun filament and taking the average value, but it can also be calculated by measuring any single fiber contained in the nonwoven fabric.

[0019] The higher the irregularity, the longer the protrusions, and the lower the irregularity, the shorter the protrusions. A nonwoven fabric using a single fiber having short protrusions with an irregularity of less than 1.1 tends to have a tendency that the protrusions do not easily enter the recesses of the object to be wiped, and the fibers tend to easily come into contact with each other, resulting in a dense nonwoven fabric. On the other hand, a nonwoven fabric using a single fiber having long protrusions with an irregularity of more than 2.0 tends to have protrusions that are easily deformed by stress, and the nonwoven fabric also tends to be easily deformed. From the viewpoint of making this effect more remarkable, the irregularity is preferably 1.1 to 1.5.

[0020] (3) CV% of irregularity Next, the CV% of the irregularity of the single fiber of the present invention will be described. CV% is a value obtained by dividing the standard deviation of the irregularity by the average irregularity, and the higher the CV%, the more non-uniform the length of the protrusions. It is essential that the irregularity CV% of the single fiber of the present invention is 2.0 or less. By setting the CV% to 2.0 or less, a nonwoven fabric with little in-plane variation and stable wiping ability and bulkiness can be obtained. From the viewpoint of making this effect more prominent, the CV% is preferably 1.5 or less.

[0021] (4) Hollowness ratio The hollow ratio of the single fiber in the present invention is preferably 20% or less. Here, the hollow ratio will be explained with reference to Fig. 1B and Fig. 1C. The radius of the circumscribing circle B passing through the three intersection points (points d, e, and f) of the protrusions is radius Rb, and the radius of the circle C circumscribing the triangular hollow is radius Rc. The hollow ratio is calculated as follows: Hollow ratio = (radius Rc / radius Rb) 2 The hollowness of the single fiber of the present invention is defined as 1×100. The hollowness of the single fiber of the present invention is preferably 20% or less, more preferably 15% or less, and even more preferably 10% or less. By setting the hollowness within the above-mentioned range, the single fiber becomes less likely to deform due to stress, and the nonwoven fabric using this fiber also becomes less likely to deform.

[0022] Here, in the nonwoven fabric of the present invention, it is preferable that the single fiber contained in the nonwoven fabric has a hollow ratio of 20% or less and a degree of irregularity of 1.1 to 2.0. When the single fiber has the above-mentioned form, the nonwoven fabric of the present invention has excellent wiping properties and is further suppressed from being deformed by stress during wiping.

[0023] (5) Fineness The fineness of the single fiber of the present invention is 5.0 dtex or less. If the fineness of the single fiber exceeds 5.0 dtex, the flexibility of the single fiber is inferior, and the flexibility of the nonwoven fabric using this fiber is also reduced, so that when used as a wiping sheet, the ability to follow the target object is reduced and the wiping ability is poor. From the above-mentioned viewpoint, the fineness is preferably 4.0 dtex or less. On the other hand, the hollow ratio decreases as the fineness becomes thinner, so it is preferably 0.8 dtex or more.

[0024] (6) Manufacturing method of single fiber The method for producing the single fibers contained in the nonwoven fabric of the present invention will be described. The single fibers contained in the nonwoven fabric of the present invention may be spun by a melt spinning method to obtain filaments, and then cut appropriately according to the fabric manufacturing method. The cut length may be about 0.3 to 10 mm when fabric is manufactured by a wet papermaking method, and about 10 to 60 mm when fabric is manufactured by a carding method.

[0025] The resin of the single fiber used in the present invention may be appropriately selected from synthetic resins such as polyolefin, polyester, and nylon, and is not particularly limited. However, polyester, which is relatively inexpensive, and nylon, which has excellent flexibility and abrasion resistance, are preferable.

[0026] <Nonwoven fabric> Next, the nonwoven fabric of the present invention will be described. The nonwoven fabric of the present invention contains the above-mentioned single fibers, and is made into a nonwoven fabric by a known method such as a wet papermaking method or a carding method. In addition to the above-mentioned single fibers, i.e., the irregular hollow fibers, the nonwoven fabric may contain fibers made of other thermoplastic resin single components such as olefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate and polylactic acid, composite fibers made of two or more types of thermoplastic resins, plant-based natural fibers such as cellulose pulp and cotton, and regenerated fibers such as rayon and cupra.

[0027] Among these fibers, it is preferable to include cellulose pulp in addition to the above-mentioned monofilaments, from the viewpoint of contributing to suppression of fiber shedding and making the tensile strength of the nonwoven fabric excellent. Cellulose pulp is a pulp whose main component is cellulose, and examples thereof include N pulp (coniferous pulp) and L pulp (hardwood pulp) made of wood fibers, and hemp pulp, bagasse pulp, kenaf pulp, bamboo pulp, etc. made of plant fibers other than wood, and it is preferable to include one or more of these pulps. By using these cellulose pulps in a beaten and fibrillated state, a nonwoven fabric with excellent tensile strength is obtained due to the interaction between cellulose molecules caused by hydrogen bonds, and the wiping sheet made of this nonwoven fabric is less likely to break. The cellulose pulp used in the present invention is not particularly limited, but from the viewpoint of obtaining a stronger nonwoven fabric, it is preferable to use N pulp (coniferous pulp) and L pulp (hardwood pulp) made of wood fibers, either alone or in combination.

[0028] Furthermore, from the viewpoint of suppressing fiber sheath dropout and improving tensile strength, it is preferable to include core-sheath type composite short fibers made of two types of thermoplastic resins. The core-sheath type composite short fibers are not particularly limited as long as the resin constituting the sheath has a lower melting point than the resin constituting the core. Examples of the resin combination constituting the core / sheath include polypropylene / polyethylene, polyester / polyethylene, and polyester / polyester copolymer. In the core-sheath type composite short fibers of the present invention, the resin in the sheath with a low melting point melts due to thermal energy such as hot air or heat press. Therefore, in a nonwoven fabric using the core-sheath type composite short fibers, other fibers such as irregular hollow fibers are partially thermally bonded by the core-sheath type composite short fibers, resulting in a nonwoven fabric with less fiber dropout and excellent tensile strength.

[0029] The weight of the nonwoven fabric of the present invention is 10 to 120 g / m 2 The lower limit is preferably 20 g / m 2 On the other hand, the upper limit is 100 g / m 2 It is preferable that the weight is 10 g / m or less. 2 By setting the density to 120 g / m or more, the nonwoven fabric of the present invention can be easily handled during production or when used as a wiping sheet. 2 By setting the following, the flexibility of the nonwoven fabric is improved, and the conformability of a wiping sheet using the nonwoven fabric is improved, resulting in excellent wiping properties.

[0030] Next, when the basis weight of the nonwoven fabric of the present invention is within the above range, the porosity of the nonwoven fabric is preferably 70% or more and 95% or less from the viewpoint of making the nonwoven fabric tear-resistant and have good liquid retention when used as a wiping sheet. By making the porosity 70% or more, the voids for retaining the chemical solution are sufficient, and by making it 95% or less, the nonwoven fabric is tear-resistant.

[0031] The nonwoven fabric of the present invention can be produced by entangling (or bonding) a web made by a wet papermaking method or a carding method by a method such as hydroentangling, thermal bonding, or needle punching.

[0032] <Wiping sheet> The wiping sheet using the nonwoven fabric of the present invention comprises the above-mentioned nonwoven fabric. That is, the above-mentioned wiping sheet comprises a nonwoven fabric using a specific irregular hollow fiber, and therefore has excellent wiping properties, liquid retention, and is difficult to deform under stress. Therefore, the above-mentioned wiping sheet has excellent dirt removal performance regardless of whether it is in a dry state or a wet state. EXAMPLES

[0033] The present invention will be described in more detail below with reference to examples. The measurement methods for the properties of the single fibers and nonwoven fabrics shown in the examples are as follows.

[0034] <Single fiber: irregular cross-section hollow fiber> A. Single yarn size (1) The multifilament was set on a measuring device with a speed of 1.125 m / turn and rotated 500 times to produce a looped skein. (2) The skein was dried in a hot air dryer (105±2°C x 60 minutes), the mass was measured, and the total fineness was calculated by multiplying it by the official moisture regain. The official moisture regain of nylon was 4.5%. (3) The total fineness was divided by the number of filaments to calculate the single yarn fineness.

[0035] B. Hollow ratio, irregularity, CV% of irregularity A thin section was cut out in the cross-sectional direction at any position of the multifilament, and the entire filament in the cross-section was photographed under a transmission microscope. The image was printed out at 1000x magnification using a printer (Mitsubishi Electric SCT-P66), and then scanned (black and white photograph, 400 dpi) using a scanner (Epson GT-5500WINS). The hollow ratio, irregularity, and CV% of the irregularity were determined as follows using image processing software (WIN ROOF) while magnified 1500x on the display. (1) Draw circumscribing circles A, B, and C as illustrated in Figures 1B and 1C. Circumscribing circle A: A circle that passes through the three outermost points (points g, h, and i) of the protrusion protruding from the intersection points (points d, e, and f) of the protrusion Circumscribing circle B: A circle that passes through the three intersection points (points d, e, and f) Circumscribed circle C: A circle passing through three points (point a, point b, point c) in a hollow triangle (2) Calculate the radii of the circumscribing circles A, B, and C as radius Ra, radius Rb, and radius Rc, respectively. (3) The hollow ratio was calculated as follows: Hollowness ratio = (radius Rc / radius Rb) 2 ×100 The fiber cross sections of all filaments were measured, and the average value was taken as the hollow ratio. It is also possible to calculate the hollow ratio by measuring any single fiber contained in the nonwoven fabric. (4) The irregularity and the CV% of the irregularity were calculated as follows. Degree of irregularity = radius Ra / radius Rb The fiber cross sections of all filaments were measured, and the average value was taken as the irregularity. The standard deviation of the irregularities of all filaments was calculated, and the value divided by the average irregularity was taken as the CV% of the irregularity. Note that the irregularity can also be calculated by measuring any single fiber contained in the nonwoven fabric.

[0036] <Nonwoven fabric> A.Basic weight (1) Reference Standards JIS P8124:1998 (2)Measurement method Measure the mass (g) and measure it over 1m. 2 Mass per unit (g / m 2 ) was converted. (3) Measurement conditions Size: 100mm x 100mm Number of items: 5.

[0037] B. Thickness (1)Measurement method Measurements were taken using a digital thickness gauge "SMD-565J-L (manufactured by Techclock Corporation)." (2) Measurement conditions Probe: φ10mm ceramic Number of items: 5.

[0038] C. Porosity (1)Measurement method Mass (g), volume (cm 3 ) and the apparent density (g / cm 3 ), and then the porosity (%) was calculated. The true density of nylon is 1.13 g / cm 3 , the true density of polyester is 1.38g / cm 3 was used. (2) Calculation formula Apparent density = mass (g) / volume (cm 3 ) Porosity (%) = (1 - apparent density / true density) x 100.

[0039] D. Water retention capacity (1)Measurement method The test specimen whose mass A (g) was measured was immersed in distilled water, then removed and one end of the test specimen was hung by a clip and left to stand.Then, the mass B (g) was measured and the water retention capacity was calculated using the following formula. (2) Calculation formula Water retention amount (g / 100cm 2 )=mass B-mass A (3) Measurement conditions Size: 10cm x 10cm Soaking time: 10 minutes Settling time: 1 minute Number of items: 3.

[0040] E. Tensile strength (1) Reference Standards JIS P8113:2006 (2)Measurement method The tensile strength of the test specimen was measured using an Autograph AGS-J (manufactured by Shimadzu Corporation), and the average value of the measurements in the vertical and horizontal directions was recorded as the tensile strength. (3) Measurement conditions Size: 150mm x 15mm Grip distance: 50mm Pulling speed: 20mm / min Number of rows: 5 vertically and 5 horizontally.

[0041] F. Wipeability (1)Measurement method (a) Lip balm was applied from any side of a rectangular glass plate (80×80 cm) to the opposite side. When applying the lip balm, a weight of 100 g±5 g was applied, and the lip balm was applied evenly so that the application width was 2 cm. Here, a more detailed explanation will be given with reference to FIG. 2A. FIG. 2A is a first schematic diagram of a glass plate to which lip balm was applied in the test method for the wiping property test, in which lip balm 5 is applied on one side of a rectangular glass plate 4 from the left side of the glass plate 4 to the opposite right side. The application width 7 of the lip balm is 2 cm. (b) A friction element (contact surface 10 × 15 mm) was prepared and covered with a nonwoven fabric test piece in a U-shape, so that the entire contact surface of the friction element was covered with the test piece. (c) The lip balm applied in (a) was wiped off with the frictional element to which the test specimen prepared in (b) was attached. The weight applied during wiping was 1 kg. Next, the wiping direction will be explained with reference to FIG. 2B. FIG. 2B is a second schematic diagram of a glass plate to which lip balm was applied in the test method for the wiping property test. Lip balm 5 was wiped off in a wiping direction 6 from the upper side of glass plate 4 to the lower side opposite to this side. (2) Evaluation of wiping ability The wiping ability of the lip balm was evaluated using two methods: haze and visual inspection. Note that the more lip balm remained, the greater the light scattering, resulting in a higher haze value. (a) Hayes The haze of the glass plate after wiping off the lip balm was measured using a HazeMeter (NDH4000: manufactured by Nippon Denshoku Industries Co., Ltd.). The measurement was performed according to JIS K7136, and a light source of D65 was used. (b) Visual inspection After wiping off the lip balm, the glass plate was visually inspected and rated on a three-point scale. A: No wiping marks left behind B: Slight wiping marks remain C: Clear wiping marks remain

[0042] [Example 1] <Single fiber: irregular cross-section hollow fiber> A method for producing the monofilaments contained in the nonwoven fabric of the present invention, i.e. the modified cross section hollow fibers, will now be described.

[0043] Nylon 6 chips (melting point 225°C, titanium oxide 0.3 mass%, moisture content 0.03 mass% or less) were melted at a spinning temperature of 265°C and extruded from a spinneret (extrusion rate 29.4 g / min), then stretched with a stretching roller (set at 170°C), heat set, and wound up at 4000 m / min to obtain a nylon 6 multifilament of 78 dtex and 24 filaments. The spinneret used had 24 holes and was shaped like a single thread.

[0044] The modified cross-section hollow fiber had the cross-sectional shape shown in FIG. 1A, with a degree of irregularity of 1.3, a hollow ratio of 6.0%, a CV of the modified cross-section of 1.5%, and a single fiber fineness of 3.25 dtex.

[0045] <Nonwoven fabric manufacturing method> 80% by mass of modified cross section hollow fiber (single filament fineness: 3.25 dtex, fiber length: 3 mm) and 20% by mass of core-sheath type composite short fiber (single filament fineness: 1.1 dtex, fiber length: 5 mm) in which the resin constituting the core is polyester and the resin constituting the sheath is copolymerized PET were stirred in water, made into paper, and then dried at 110° C. Further, spunlace processing was carried out to obtain a nonwoven fabric.

[0046] [Example 2] <Single fiber: irregular cross-section hollow fiber> A modified cross section hollow fiber was obtained in the same manner as in Example 1, except that the spinneret was changed to have 48 holes and one filament. This modified cross section hollow fiber had the cross-sectional shape shown in Figure 1A, a non-circularity of 1.1, a hollowness of 4.0%, a CV of the non-circularity of 1.2%, and a single filament fineness of 1.63 dtex.

[0047] <Nonwoven fabric manufacturing method> A nonwoven fabric was obtained in the same manner as in Example 1.

[0048] [Example 3] A nonwoven fabric was obtained in the same manner as in Example 2, except that the amount of the modified cross-section hollow fiber used in Example 2 was 70 mass %, the amount of the core-sheath composite short fiber (single fiber fineness: 1.1 dtex, fiber length: 5 mm) in which the resin constituting the core was polyester and the resin constituting the sheath was copolymerized PET was 20 mass %, and the amount of the cellulose pulp (CSF = 200) was 10 mass %.

[0049] [Comparative Example 1] A nonwoven fabric was obtained in the same manner as in Example 1, except that the material used was 80 mass% round cross-section yarn (nylon 6, single yarn fineness: 3.25 dtex, fiber length: 3 mm) and 20 mass% core-sheath type composite short fibers (single yarn fineness: 1.1 dtex, fiber length: 5 mm) in which the resin constituting the core was polyester and the resin constituting the sheath was copolymerized PET.

[0050] The nonwoven fabrics of Examples 1 to 3 and Comparative Example 1 were evaluated for each characteristic value using the measurement methods described above. The results are shown in Table 1.

[0051] Example 1, which contains 80% by mass of modified cross section hollow fibers having a single fiber fineness of 3.25 dtex and a CV of 1.5%, and Example 2, which contains 80% by mass of modified cross section hollow fibers having a single fiber fineness of 1.63 dtex and a CV of 1.2%, were nonwoven fabrics with higher bulk (thicker thickness at the same basis weight), higher porosity, and higher water retention than Comparative Example 1, which contains 80% by mass of round cross section yarn having a single fiber fineness of 3.25 dtex. In addition, the haze of the glass after the wiping property test was low, and the visual evaluation was rated A, indicating excellent wiping property.

[0052] In addition, Example 3, which contained 70% by mass of modified cross section hollow fibers with a single fiber fineness of 1.63 dtex and a CV of 1.2% and added 10% by mass of cellulose pulp, had a tendency to have a lower porosity and water retention rate than Example 2, but was a nonwoven fabric with excellent tensile strength. Furthermore, it was confirmed that the hollow parts of the modified cross section hollow fibers contained in the nonwoven fabrics of Examples 1 to 3 were triangular, and that each side of the triangle had a protrusion. Since the nonwoven fabrics contained such modified cross section hollow fibers, the nonwoven fabrics of Examples 1 to 3 were nonwoven fabrics that were difficult to deform due to stress during wiping.

[0053] [Table 1] [Industrial Applicability]

[0054] The nonwoven fabric of the present invention is excellent in wiping ability and liquid retention, and is not easily deformed by the stress during wiping, and therefore can be suitably used as a wiping sheet. [Explanation of symbols]

[0055] 1: Special cross-section hollow fiber 2: Triangular hollow 3:Protrusion 4: Glass plate 5. Lip balm 6: Wiping direction 7: Coating width A: Circumscribed circle A B: Circumscribed circle B C: Circumscribed circle C a, b, c: vertices of hollow triangle d, e, f: Intersection of protrusions g, h, i: outermost points of the protrusion

Claims

1. Contains single fibers, The single fiber is a modified cross-section hollow fiber, In a cross section of the single fiber, the single fiber has a triangular hollow portion and protrusions on the extensions of each side of the triangle, The single fiber has a single yarn fineness of 5.0 dtex or less, The nonwoven fabric, wherein the CV% of the degree of deformation of the single fiber is 2.0 or less.

2. The hollow ratio of the single fiber is 20% or less, 2. The nonwoven fabric according to claim 1, wherein the degree of deformation of the single fiber is 1.1 to 2.

0.

3. The nonwoven fabric of claim 1 or 2, further comprising cellulose pulp.

4. Weight per unit area is 10g / m ２ 120g / m or more ２ The nonwoven fabric according to any one of claims 1 to 3, wherein the porosity is 70% or more and 95% or less.

5. A wiping sheet using the nonwoven fabric according to any one of claims 1 to 4.

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