WO2020105585A1 - Wiping sheet and production method therefor - Google Patents

Abstract

The wiping sheet (1) according to the present invention is formed by impregnating, with a cleaning liquid (5), fiber aggregate (1A) which contains a synthetic fiber (2). The fiber aggregate (1A) in a dry state has a basis weight of 50-100 g/m². The cleaning liquid (5) contains two types of non-ionic surfactants, one of the non-ionic surfactants having an HLB value of not less 12 but less than 15, and the other non-ionic surfactant having an HLB value of 15-18. The wiping sheet (1) is impregnated with the cleaning liquid (5) in an amount of 205-380 g/m².

Description

Wiping sheet and manufacturing method thereof

The present invention relates to a wiping sheet and a manufacturing method thereof.

A synthetic nonwoven fabric entangled non-woven fabric is a wet sheet in which the non-woven fabric is impregnated with a cleaning liquid, and is used for cleaning hard surfaces such as indoors and cars. For example, Patent Document 1 discloses a cleaning wet sheet in which a low-flowing aqueous liquid is held and a surface layer serving as a cleaning surface is liquid-permeable. Patent Document 2 discloses a cleaning sheet in which a sheet material contains a surfactant. The same document also discloses that the content of the surfactant is 0.01 to 50 times the amount of the material of the sheet, and has the effect of cleaning oil stains.

JP-A-2002-45323 JP, 2006-305178, A

The present invention relates to a wiping sheet obtained by impregnating a fiber assembly containing synthetic fibers with a cleaning liquid. The basis weight of the fiber assembly in the dry state of the wiping sheet is 50 g / m ² or more and 100 g / m ² or less. The cleaning liquid contains at least two kinds of nonionic surfactants having different HLB values, one of the surfactants has an HLB value of 12 or more and less than 15, and the other surfactant has an HLB value of 15 or more 18 It is below. The wiping sheet, the cleaning solution is impregnated 205g / ^{m 2} or more 380 g / ^{m 2} or less.

The present invention also provides a method for manufacturing the wiping sheet,
The present invention provides a method for producing a wiping sheet, which comprises forming a fiber assembly containing synthetic fibers, and thereafter impregnating the fiber assembly with a cleaning liquid by spraying.

1 (a) and 1 (b) are plan views of the cross-sectional shape of modified fibers used in the wiping sheet of the present invention. FIG. 2 is a schematic view showing an embodiment of the wiping sheet of the present invention. FIG. 3 is a schematic view of a manufacturing apparatus preferably used for manufacturing the wiping sheet of the present invention. FIG. 4 is a schematic view of the uneven portion forming member in the manufacturing apparatus shown in FIG. FIG. 5: is a schematic diagram which shows the orientation of the cross section of a deformed fiber at the time of manufacture of a wiping sheet.

Detailed Description of the Invention

When the cleaning sheets described in Patent Documents 1 and 2 are used for cleaning solidified and modified oil and fat stains adhering to hard surfaces such as floors and cooking facilities, it can be said that the efficiency of removing the oil and fat stains is sufficient. However, there was room for improvement in this respect.

Therefore, the present invention relates to a wiping sheet that solves the drawbacks of the prior art.

Hereinafter, the wiping sheet of the present invention will be described based on its preferred embodiments. In the present invention, “wiping” includes both cleaning and wiping meanings, for example, floor surface, wall surfaces, cleaning of buildings such as ceilings and pillars, cleaning of fittings and fixtures, wiping of articles, This includes cleaning the body and equipment related to the body.

The wiping sheet of the present invention is a wet type sheet that contains synthetic fibers, preferably has a fiber assembly mainly composed of synthetic fibers, and the fiber assembly is impregnated with a cleaning liquid. The term "mainly composed" means that the content of the synthetic fiber in the fiber assembly in the dry state is 50% by mass or more, and the content thereof is preferably 60% by mass or more, more preferably 70% by mass. That is all.

ㆍ Synthetic fibers form a fiber aggregate by depositing, entangled, or bonded with each other. The fibers constituting the fiber assembly may or may not be fused to each other. The wiping sheet may be composed of only the fiber assembly, or may include other sheet materials or other members in addition to the fiber assembly.

The basis weight of the fiber assembly constituting the wiping sheet is preferably 50 g / m ² or more, more preferably 55 g / m ² or more, even more preferably 60 g / m ² or more, and the upper limit thereof, in the dry state of the fiber assembly. Is preferably 100 g / m ² or less, more preferably 90 g / m ² or less, still more preferably 80 g / m ² or less. Specifically, the basis weight of the fiber assembly constituting the wiping sheet is preferably 50 g / m ² or more and 100 g / m ² or less, more preferably 55 g / m ² or more and 90 g / m ² or less, and 60 g / m ² or more. It is more preferably 80 g / m ² or less. The dry state means that the amount of water contained in the fiber assembly is 3% by mass or less. When the basis weight of the fiber assembly in the dry state is in such a range, both strength at the time of using the wiping sheet and high retention of the cleaning liquid can be achieved.

From the viewpoint of manufacturing efficiency, it is preferable that the synthetic fiber is made of a fiber-forming resin as a raw material. Examples of such a resin include various thermoplastic resins. Examples of the thermoplastic resin include polyolefin resins such as polyethylene (PE) and polypropylene (PP), polyester resins such as polyethylene terephthalate (PET), polyamide resins, vinyl resins such as polyvinyl chloride and polystyrene, polyacrylic acid and the like. Examples thereof include acrylic resins such as polymethylmethacrylate, fluororesins such as polyperfluoroethylene, and the like, and one of these may be used alone or two or more thereof may be used in combination.

The fineness of the synthetic fiber is preferably 0.5 dtex or more, more preferably 1 dtex or more, and further preferably 1.2 dtex or more, from the viewpoint of operability during wiping and dirt removal efficiency. The upper limit thereof is preferably 4 dtex or less, more preferably 3.5 dtex or less, and further preferably 3 dtex or less.

The wiping sheet of the present invention is impregnated with a cleaning liquid mainly composed of water. The content of water contained in the cleaning liquid is preferably 80.0% by mass or more, more preferably 90.0% by mass or more, and 99.8% by mass or less, based on the total mass of the cleaning liquid. Is preferable, and more preferably 99.0 mass% or less.

The cleaning liquid contains at least two kinds of nonionic surfactants having HLB values within a predetermined range and different HLB values. The HLB value is an index showing the balance between hydrophilicity and lipophilicity (hydrophile lipophile balance), and in the present invention, the value calculated by the following equation (1) by Oda and Teramura et al. Is used.
HLB value = (Σ inorganic value / Σ organic value) × 10 (1)

The two types of nonionic surfactants contained in the cleaning liquid have an HLB value of one or more nonionic surfactants (hereinafter, also referred to as “first nonionic surfactant”), preferably 12 or more, It is more preferably 12.5 or more, still more preferably 13 or more, and preferably less than 15, more preferably 14.5 or less, still more preferably 14 or less. By using the nonionic surfactant having the HLB value in such a range in combination with the other nonionic surfactant described later, the dispersibility of the emulsified oil stains in the cleaning liquid can be increased. As a result, it is possible to effectively remove the oil stains that have solidified and adhered to the hard surface.

The HLB value of the other nonionic surfactant (hereinafter, also referred to as “second nonionic surfactant”) is preferably 15 or more, more preferably 15.5 or more, still more preferably 16 It is above, and preferably 18 or less, more preferably 17.5 or less, still more preferably 17 or less. Thus, in addition to the above-mentioned first nonionic surfactant, by further containing a nonionic surfactant having a relatively high HLB value, it is possible to promote the emulsification of solidified oil and fat stains, and as a result, hard It is possible to effectively remove oil and fat stains solidified and attached to the surface.

Examples of the first nonionic surfactant include polyoxyethylene lauryl ether (HLB value: 12.1 to 14.9), polyoxyethylene cetyl ether (HLB value: 12.9 to 14.3), polyoxyethylene Examples thereof include polyoxyethylene alkyl ethers such as ethylene stearyl ether (HLB value: 12.8 to 13.9) and polyoxyethylene oleyl ether (HLB value: 12.1 to 13.6).

Examples of the second nonionic surfactant include polyoxyethylene sorbitan monopalmitate (HLB value: 15.6), polyoxyethylene coconut oil fatty acid sorbitan (HLB value: 15.0 to 16.7), etc. And polyoxyethylene sorbitan fatty acid ester of.

As long as the effects of the present invention are exhibited, the cleaning liquid contains, as a surfactant, the first and second nonionic surfactants, and also a nonionic surfactant having an HLB value of less than 12 and an HLB value of 18 or less. It may contain a super nonionic surfactant, a cationic surfactant, an anionic surfactant, and an amphoteric surfactant. From the viewpoint of making the effect of the present invention more prominent, the cleaning liquid contains, as a surfactant, only two kinds of nonionic surfactants having the above-mentioned HLB value, or in addition to these surfactants. Therefore, it is preferable to include an amphoteric surfactant. Examples of the amphoteric surfactant used in the present invention include at least one selected from lauryldimethylamine oxide, alkylbetaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine and the like.

From the viewpoint of supplying a sufficient amount of liquid for emulsifying and removing the solidified oil and fat stains, the impregnation amount of the cleaning liquid with which the fiber assembly is impregnated is preferably 205 g / m ² or more, and more preferably 260 g / m ² or more. preferably, also, preferably 380 g / ^{m 2} or less, more preferably 325 g / ^{m 2} or less. In other words, when the size of the wiping sheet is set to 285 mm × 205 mm, for example, as described in Examples below, 12 g / sheet or more is preferable, 15 g / sheet or more is further preferable, and 22 g / sheet or less is preferable, 19 g / sheet or less is more preferable.

The wiping sheet of the present invention having the above configuration is impregnated with the cleaning liquid containing two kinds of nonionic surfactants having different HLB value ranges from each other. The emulsification can be promoted, and at the same time, the dispersibility of the emulsified oil and fat stain in the cleaning liquid can be enhanced. As a result, by wiping the surface to be cleaned with the wiping sheet of the present invention, it is possible to effectively remove the oil stains that have been solidified and modified.

From the viewpoint of further improving the efficiency of removing solidified and modified oil and dirt, and suppressing stickiness and sliminess of the surface to be cleaned after wiping to improve the usability, the cleaning liquid is the first and second nonionic surface active agents. It is preferable that the agents each independently contain 0.1% by mass or more, more preferably 0.2% by mass or more, and independently contain 0.5% by mass or less, and 0.4% by mass or less. It is more preferable to include. The total amount of the first and second nonionic surfactants in the cleaning liquid is preferably 0.2% by mass or more, more preferably 0.4% by mass or more, and 1.0 It is preferably not more than mass%, more preferably not more than 0.8 mass%.

The cleaning liquid with which the wiping sheet is impregnated preferably has a foam height (foam height) measured by the Loss Miles method that has a predetermined height. Specifically, the bubble height immediately after measurement, which is measured by the loss miles method, is preferably 130 mm or more, more preferably 140 mm or more, and preferably 180 mm or less, and 170 mm or less. More preferably, it is even more preferably 160 mm or less.

Further, the bubble height measured by the loss miles method after 5 minutes is preferably 110 mm or more, more preferably 120 mm or more, and preferably 170 mm or less and 160 mm or less. Is more preferable, and still more preferably 150 mm or less. By using the cleaning liquid having such a foam height, it is possible to more effectively remove the solidified and modified oil stain. In order to bring the foam height measured by the loss miles method into the above range, for example, the content of the nonionic surfactant in the cleaning liquid is adjusted, or the anionic surfactant, the cationic surfactant, and the amphoteric interface are used. An activator, a solvent such as alcohol, and silicone can be added.

The foam height can be measured by the lossmiles method using the liquid to be measured, for example, by the method specified in JIS K 3362 or ASTM D 1173. As the liquid to be measured, for example, the cleaning liquid before impregnating the fiber assembly is used as it is, or the residual liquid remaining on the surface to be cleaned when wiping the surface to be cleaned with a wiping sheet, or the cleaning liquid for the wiping sheet or the like. The extract obtained by a method of squeezing, pressing, centrifuging, etc., the fiber assembly impregnated with can be manually used, equipment such as an extraction member or machine, or the like can be used. The foam height immediately after the measurement is an evaluation of the foaming power indicating the foamability of the cleaning liquid, and the foam height 5 minutes after the measurement is an evaluation of the foam stability indicating the difficulty of disappearing the foam after foaming. When the foam height is within the above range, the solidification-modified fat and oil stain can be more effectively removed. It is preferable that at least the measurement value of the foam height measured by the loss miles method using the cleaning liquid before impregnation in the fiber assembly as the liquid to be measured satisfies the above range.

From the viewpoint of further increasing the efficiency of removing the solidified and modified oil and fat stain, the cleaning liquid released from the wiping sheet preferably has a pH at 25 ° C. of 7.8 or higher, more preferably 8.0 or higher, Further, it is preferably 9.0 or less, and more preferably 8.5 or less. In order to adjust the pH of the cleaning liquid to the above range, it can be adjusted, for example, by adding a pH adjusting agent to such an extent that the effect of the present invention is exhibited.

From the same viewpoint, the viscosity of the cleaning liquid discharged from the wiping sheet at 25 ° C. is preferably 2 mPa · s or more, more preferably 3 mPa · s or more, and 10 mPa · s or less. Is preferable, and more preferably 8 mPa · s or less. The viscosity of the cleaning liquid is 100 mL of the liquid to be measured at 25 ° C., placed in a beaker, and a low viscosity spindle (spindle No. M1) attached VISCOMETER TVB-10 manufactured by Toki Sangyo Co., Ltd. It can be a value measured under the condition of 60 rpm and 1 minute in the immersed state. In order to make the viscosity of the cleaning liquid within the above-mentioned range, it can be adjusted, for example, by adding a viscosity adjusting agent to the extent that the effect of the present invention is exhibited.

From the same viewpoint, the cleaning liquid released from the wiping sheet preferably has a surface tension of 25 mN / m or more, more preferably 27 mN / m or more, and 35 mN / m or less. Is preferred and 33 mN / m or less is more preferred. As for the surface tension of the cleaning liquid, a small petri dish containing about 10 mL of the liquid to be measured at 25 ° C. is left stationary on the measuring stage of the automatic surface tension meter CBVD-Z manufactured by Kyowa Interface Science Co., Ltd., and the upper spring of the device is measured. The value can be obtained when the platinum plate is lowered while the platinum plate is suspended on the part, and the force with which the platinum plate is drawn into the liquid sample when it comes into contact with the liquid sample and the spring load are in equilibrium. .. In order to make the surface tension of the cleaning liquid within the above range, for example, the total content of the surfactant in the cleaning liquid can be adjusted, or a solvent such as alcohol, silicone, or the like can be added.

The pH, viscosity, and surface tension of the cleaning liquid released from the wiping sheet are, for example, the residual liquid remaining on the cleaning target surface when the wiping sheet is used to wipe the cleaning target surface, or the cleaning liquid such as the wiping sheet The impregnated fiber aggregate is measured by using an extract obtained by a method such as squeezing, pressing, centrifuging, etc., with a hand, an extraction member, equipment such as a machine, as a measurement target liquid. be able to.

From the viewpoint of reducing unpleasant odors caused by oil and fat stains during and after wiping, the cleaning liquid preferably contains a fragrance. The fragrance used in the present invention is preferably one that dissolves in a cleaning liquid, for example, menthol, geraniol, citronellal, citronellol, 1,8-cineole, terpineol, menthol, linalool and the like, rose fragrance tone, A fragrance composition containing a fragrance having a lavender scent, a jasmine scent, or a ylang-ylang scent can also be used. These fragrance components and fragrance compositions can be used alone or in combination of two or more. As for these flavors, a solution in which the content concentration is adjusted in advance by diluting with a solvent may be used. The cleaning liquid preferably contains 0.01% by mass or more, more preferably 0.02% by mass or more, preferably 1.0% by mass or less, and further preferably 0.95% by mass or less. preferable.

The cleaning liquid may further contain an additive in addition to the above-mentioned components as long as the effect of the present invention is exhibited. Examples of the additives include surfactants other than the above-mentioned surfactants, bactericides, preservatives, aromatics, deodorants, pH adjusters, chelating agents, viscosity adjusters, solvents such as alcohols, and the like. These may be used alone or in combination. These additives are preferably contained in the cleaning liquid in an amount of preferably 0.001% by mass or more and 20% by mass or less, depending on the properties required of the wiping sheet.

Returning to the description of the fiber assembly, the synthetic fiber forming the fiber assembly includes a synthetic fiber having a flat cross-sectional shape (hereinafter, this synthetic fiber is also referred to as a “deformed fiber”). Is preferred. The flat cross section of the fiber means that, in the cross section of the fiber (cross section orthogonal to the length direction of the fiber), the length of the longest line segment among the line segments crossing the cross section is A, and The length A is longer than the length B, where B is the length of the longest line segment that is orthogonal to the line segment and crosses the cross section. That is, the deformed fiber has a major axis and a minor axis in its cross section. The irregularly shaped fibers are preferably line-symmetrical with a line segment of length A as a line of symmetry.

The deformed fibers having the cross-sectional shape of such a fiber include, for example, those having an oval shape shown in FIG. 1 (a) and a multi-lobed shape shown in FIG. 1 (b). In the deformed fiber shown in FIG. 1 (a) in which the cross-sectional shape of the fiber is an ellipse, the length A is the major diameter of the ellipse, and the length B is the minor diameter of the ellipse (hereinafter, in this specification, the irregularly shaped fiber. The length A is also referred to as a “major axis” and the length B is also referred to as a “minor axis” regardless of the cross-sectional shape of the above. When the synthetic fiber is a deformed fiber having the above-described shape, the ability to collect fiber stains such as hair in addition to oil stains can be enhanced. In addition, voids can be easily generated between the fibers in the fiber assembly, and both effective collection of fine particle dirt and retention of the cleaning liquid are achieved.

From the viewpoint of realizing more effective collection of fine particle dirt in addition to effective collection of fiber dirt such as hair, when the synthetic fiber contained in the wiping sheet is a modified fiber, in the cross-sectional shape of the fiber, Preferably, at least one convex portion having a sharp apex is provided, more preferably two or more, and even more preferably three or more. The sharp apex means that, when the contour of the convex portion in the cross-sectional shape of the irregularly shaped fiber is defined by, for example, (a) two non-parallel straight lines intersecting with each other, (b) one straight line and one straight line And the case where it is defined by intersecting two curves, and (c) the case where it is defined by intersecting two curves. For example, the deformed fiber shown in FIG. 1 (b) has eight sharp peaks. The sharp top portion preferably extends in a direction intersecting the major axis, and preferably extends in a direction orthogonal to the major axis. In the present invention, one type of modified fiber may be used alone, or two or more types of modified fibers having different cross-sectional shapes may be used in combination. As the other deformed fiber having a sharp apex, the cross-sectional shape thereof is, for example, a triangle, a quadrangle, a convex polygon such as a pentagon and a hexagon, provided that it has a ratio of a major axis and a minor axis described below. It may be a star polygon, a W shape, or the like.

In particular, from the viewpoint of increasing the specific surface area of the constituent fibers to further enhance the retention of the cleaning liquid and the collection of the fine particles, as shown in FIG. When viewed along, it is preferable that the shape has a plurality of convex portions P and a concave portion R located between the adjacent convex portions P.

The wiping sheet of the present invention made of a fiber assembly containing synthetic fibers can be a substantially rectangular sheet having a longitudinal direction X and a width direction Y orthogonal to the direction as shown in FIG. 2, for example. Further, as shown in the figure, it is preferable that the wiping sheet 1 has at least one surface thereof a concavo-convex portion of a macroscopic pattern having a curved portion, and as a wiping surface (a surface in contact with a cleaning target surface). It is more preferable that the surface to be used has a macroscopic pattern of irregularities having curved portions. With such a configuration, it is possible to more effectively remove the solidified and modified fat and oil stain, and it is possible to more effectively collect fine particle stains and fiber stains such as hair.

As shown in the figure, a concave portion 3 and a convex portion 4 which form a concave and convex portion are formed on one surface of the wiping sheet 1. The boundary line between the concave portion 3 and the convex portion 4 has a curved portion when viewed macroscopically. When the concavo-convex portion of the macroscopic pattern is formed on one surface, the other surface is flat without concavity and convexity derived from the concavo-convex portion of the macroscopic pattern.

The concavo-convex portion of the macroscopic pattern is not limited to the macroscopic pattern shown in the same figure, and for example, the macroscopic pattern disclosed in Japanese Unexamined Patent Application Publication No. 2017-113182 and figures such as straight lines, curves, circles and polygons are appropriately combined. It may be a macroscopic pattern. In addition, a curved line when viewed macroscopically means a figure that forms an uneven portion, except for a curve that forms a microscopic microscopic hole and a curve that forms a drainage hole with a diameter of about 1.5 to 2 mm. It means that it is possible to visually confirm that a part of the side of is a curve. From such a viewpoint, the area of each convex portion 4 surrounded by the concave portion 3 should be 300 mm ² or more, It is preferable to form the concave portion 3 and the convex portion 4. By having such a macroscopic pattern of irregularities, there is an advantage that the designability of the wiping sheet itself is enhanced.

When the synthetic fiber contained in the wiping sheet is a deformed fiber, the fiber orientation is different in the concave portion 3 and the convex portion 4 which form the concave-convex portion of the macroscopic pattern. Specifically, the irregularly shaped fibers present in the concave portions 3 are oriented so that the flat surface thereof faces the surface of the wiping sheet (the paper surface direction in FIG. 2), and the irregularly shaped fibers present in the convex portions 4 are flattened. The surface is oriented so as to face the surface orthogonal to the surface of the wiping sheet (the surface orthogonal to the paper surface in FIG. 2).

In other words, the deformed fibers present in the recesses 3 have a major axis in the cross section generally oriented in the direction along the surface of the wiping sheet, and the deformed fibers present in the protrusions 4 have a short diameter in the cross section. It is generally oriented along the surface of the wiping sheet. Thus, by allowing a plurality of regions having different flat plane orientations of the irregularly-shaped fibers to be present on the wiping surface of the wiping sheet, it is possible to more effectively remove the solidification-modified fat and oil stains, and the fine particles caused by the high degree of freedom of the fibers. It has both the dirt collecting property and the fiber dirt collecting property such as hair due to the rigidity of the fiber.

When the synthetic fibers contained in the wiping sheet are irregularly shaped fibers, "the major axis of the cross-section of the fiber is substantially in the direction along the surface of the wiping sheet" means that 10 or more irregularly shaped fibers are observed. In addition, 50% or more (based on the number of fibers) of the fibers have an angle between the major axis of the fibers and the surface of the wiping sheet of less than 45 degrees (hereinafter, this is also referred to as “major axis orientation”). In addition, "the major axis of the transverse cross section of the fiber is generally in the direction along the plane orthogonal to the surface of the wiping sheet" means that when 10 or more modified fibers are observed, 50% of the modified fibers ( The above (based on the number of fibers) means that the angle formed by the major axis of the irregularly shaped fibers and the surface of the wiping sheet is 45 degrees or more (hereinafter, this is also referred to as "minor axis orientation").

When the synthetic fiber contained in the wiping sheet is a deformed fiber, from the viewpoint of enhancing the collection property of fine particle dirt, in the deformed fiber present in the concave portion in the macroscopic pattern, the major axis of the cross section is the direction along the surface of the wiping sheet. As for the ratio of the fibers oriented toward, is preferably 50% or more, more preferably 60% or more, further preferably 100% or less, and further preferably 80% or less, based on the number of deformed fibers.

Similarly, from the viewpoint of enhancing the ability to collect fiber stains such as hair, in the deformed fiber present in the convex portion in the macroscopic pattern, the major axis of its cross section is directed in the direction along the plane orthogonal to the surface of the wiping sheet. The ratio of orientation is preferably 50% or more, more preferably 60% or more, still more preferably 100% or less, still more preferably 80% or less, based on the number of deformed fibers. The orientation ratio can be calculated from the number of deformed fibers that satisfy the above-described orientation criteria by observation using a scanning electron microscope (SEM).

The orientation (fiber orientation) in the cross section of the irregularly shaped fiber is determined by measuring the major axis and the minor axis of the transverse section of the irregularly shaped fiber constituting the fiber assembly, and then measuring the irregularly shaped fiber observed on the surface to be measured in the wiping sheet. The fiber diameter can be measured and calculated. These major axis, minor axis and fiber diameter can be measured by the following method, for example.

That is, using a scanning electron microscope (SEM), the major axis and the minor axis of the irregularly shaped fiber are measured in advance, and then the fiber diameter of the irregularly shaped fiber observed on the surface to be measured is observed. When the fiber width observed when the angle between the major axis of the irregularly shaped fibers and the surface of the wiping sheet is 45 degrees, and the reference width of the fiber orientation is the fiber width of the irregularly shaped fibers observed on the surface to be measured, Fibers having a standard width or more and a major axis or less are determined as "major axis orientation", and fibers having a minor axis or more and less than the reference width are determined as "minor axis orientation". The number of fibers having these orientations is measured, and the ratio based on the number of fibers is calculated as the orientation ratio. The reference width of the fiber orientation may be measured by, for example, SEM observation, or may be calculated from the relationship between the major axis and the trigonometric function.

From the viewpoint of imparting sufficient strength when the wiping sheet is used, the wiping sheet of the present invention preferably further comprises a scrim net for supporting the fiber assembly. It is also preferable that the scrim net is arranged in the central region of the fiber assembly in the thickness direction. The scrim net is one that can be integrally entangled with the synthetic fibers that form the fiber assembly, and examples thereof include a net shape, a lattice shape, and a strand shape.

Resin can be used as a raw material for forming the scrim net. Examples of the resin include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon 6 and nylon 66, acrylonitrile resins such as polyacrylonitrile, vinyl resins such as polyvinyl chloride and polystyrene, and poly resins. Vinylidene-based resins such as vinylidene chloride can be used.

The wire diameter of the scrim net (diameter in the transverse cross section) can be appropriately adjusted depending on the degree of entanglement of the fibers, from the viewpoint of achieving both the entangleability of the constituent fibers and the scrim net and the strength of the wiping sheet, but 10 μm or more Is preferable, 500 μm or more is more preferable, 2000 μm or less is preferable, and 1000 μm or less is further preferable. The wire diameters of the scrim net may be partially different or the same, and when the wire diameters are partially different, the wire diameter of the scrim is the average value. The basis weight of the scrim net is preferably 1 g / m ² or more, more preferably 3 g / m ² or more, preferably 20 g / m ² or less, and more preferably 10 g / m ² or less.

The wiping sheet of the present invention may be composed only of synthetic fibers, and may further contain other fibers in addition to these fibers. As the other fibers, for example, natural fibers such as wood pulp, cotton, silk, etc., hydrophilic fibers such as regenerated fibers such as rayon and cupra, purified fibers such as lyocell, and fibers made from the above-mentioned thermoplastic resins are used. be able to. These may be used alone or in combination of two or more. The other fibers may be circular or non-circular in cross section. The other fibers are contained in the fiber assembly in a proportion of preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less.

Of the line segments that cross the cross section of the modified fiber, the length of the longest line segment is A, and the length of the longest line segment that is orthogonal to the cross section and crosses the cross section is B. Sometimes (see FIG. 1B), the ratio (A / B) of the length A to the length B is preferably 1.2 or more, more preferably 1.5 or more, and 2 or more. Is more preferable, and the upper limit thereof is preferably 5 or less, more preferably 4 or less, and further preferably 3 or less. Specifically, the value of A / B is preferably 1.2 or more and 5 or less, more preferably 1.5 or more and 4 or less, and further preferably 2 or more and 3 or less. By having such a configuration, the fibers constituting the wiping sheet are easily entangled with fiber stains such as hair, and these stains can be caught on the fibers and removed from the wiping target surface.

As an example of the length A and the length B described above, in a deformed fiber in which the cross-sectional shape of the fiber is an equilateral triangle, the length A is the length of one side of the equilateral triangle, and the length B is from a certain vertex. It will be the length of the vertical line drawn down on one side. Further, in a deformed fiber in which the cross-sectional shape of the fiber is an ellipse (see FIG. 1A), the length A is the major axis of the ellipse, and the length B is the minor axis of the ellipse.

When the wiping sheet contains two or more types of modified fibers having different cross-sectional shapes, the lengths A and B are the average value of A and the average value of B measured for all types of modified fibers. That is.

From the viewpoint of having both the operability at the time of wiping and the dirt collecting property, the length A is preferably 1 μm or more, and preferably 5 μm or more, provided that the above range of A / B is satisfied. More preferably, it is more preferably 10 μm or more, and its upper limit is preferably 80 μm or less, preferably 50 μm or less, and more preferably 25 μm or less. From the same viewpoint, the length B is preferably 0.2 μm or more, more preferably 1 μm or more, and further preferably 2 μm or more, provided that the above range of A / B is satisfied. The upper limit is preferably 40 μm or less, preferably 20 μm or less, and more preferably 15 μm or less.

As shown in FIG. 1B, when the contour line of the cross section of the irregularly shaped fiber is viewed along the circumferential direction, it has a plurality of convex portions P and concave portions R located between the adjacent convex portions P. In the case of a shape, when the length of a line segment connecting the vertices of the adjacent convex portions P is C and the length of a perpendicular line from the line segment to the bottom position of the concave portion R is D, C / D Is preferably 0.1 or more, more preferably 1 or more, even more preferably 2 or more, and the upper limit thereof is preferably 5 or less, more preferably 4 or less. It is preferably 3 or less, and more preferably 3 or less. By having such a configuration, the surface area of the fiber alone is increased and the contact area with the dirt is increased, so that the dirt collecting property can be further enhanced.

When observing the cross section of the irregularly shaped fiber, if the length C of the line segment connecting between the vertices of the arbitrarily selected adjacent convex portions P is different, the value of C for calculating the value of C / D is all The average value of C is used. Similarly, when the lengths of the perpendicular lines in the arbitrarily selected recesses R are different from each other, the value of D for calculating the value of C / D is the average value of all the values of D. In the following description, when referring to the values of C and D, the value is the average value of C and D.

From the viewpoint of improving the operability during wiping and the efficiency of collecting dirt, the length C is preferably 0.1 μm or more, and 0.5 μm or more, provided that the above range of C / D is satisfied. More preferably, it is more preferably 1 μm or more, and its upper limit is preferably 20 μm or less, preferably 10 μm or less, and more preferably 5 μm or less. From the same viewpoint, the length D is preferably 0.1 μm or more, more preferably 0.5 μm or more, and more preferably 1 μm or more, provided that the above range of C / D is satisfied. Is more preferable, and the upper limit thereof is preferably 20 μm or less, more preferably 10 μm or less, and further preferably 5 μm or less.

The lengths A to D described above can be measured, for example, by the following measuring method. That is, the produced fiber assembly is cut with a razor or the like while maintaining the cross-sectional shape of the fiber, and then the cross-section is vacuum-deposited with Pt. Using a scanning electron microscope (JSM-IT100, manufactured by JEOL Ltd.), the cross section of the Pt-deposited fiber assembly was observed at a magnification of 500 to 1000 times, and the fiber cross section was measured using the length measurement tool of the attached software. Measure lengths A through D respectively.

The above is a description of one embodiment of the wiping sheet of the present invention, and a suitable manufacturing method of the wiping sheet will be described below with reference to FIG. FIG. 3 shows a manufacturing apparatus 10 preferably used for manufacturing a wiping sheet. The manufacturing apparatus 10 includes a web forming unit 20, a water entanglement unit 30, a pattern forming unit 40, and a cleaning liquid spraying unit 60 in this order along the transport direction (MD direction). This production method is a step of forming a fiber assembly containing synthetic fibers by hydroentangling, a step of forming a concavo-convex portion of a macroscopic pattern on one surface of the fiber assembly, if necessary, a cleaning liquid by spray spraying. It is roughly divided into three processes, a process of impregnating a fiber assembly. In the following description, the conveyance direction (MD direction) and the longitudinal direction X of the wiping sheet coincide with each other, and the direction orthogonal to the conveyance direction coincides with the width direction Y of the wiping sheet.

First, the web of synthetic fibers 2 is delivered from the card machine 21 in the web forming unit 20 via the guide roll 22. When the wiping sheet is provided with the scrim net, the scrim net 15 is fed from the scrim roll 25 together with the web of the synthetic fibers 2. By these feeding, the synthetic fiber web and the scrim net are laminated.

Next, in the hydroentanglement portion 30, while the web of synthetic fibers 2 (or the laminated body of the web of synthetic fibers 2 and the scrim net 15) is conveyed in the MD direction by the first support belt 32 that is permeable to water, the first Entanglement processing is performed by the high-pressure water stream ejected from the water stream nozzle 31 (entanglement step). Through this step, the synthetic fibers 2 are entangled with each other to form the fiber assembly 1A containing the synthetic fibers and preferably mainly composed of the synthetic fibers. In the case where the scrim net is provided, the synthetic fibers 2 are entangled with each other and the synthetic fibers 2 and the scrim net 15 are integrally entangled by this step, and a fiber assembly containing the scrim net and the synthetic fibers is obtained. 1A is formed.

In this step, the water pressure sprayed from the first water jet nozzle 31 is preferably 30 kg / cm ² or more and 80 kg / cm ² or less, more preferably 40 kg / cm ² or more and 60 kg / cm ² or less, and the MD of the synthetic fiber 2 web It can be manufactured by setting the conveying speed in the direction to preferably 2 m / min or more and 10 m / min or less, and more preferably 4 m / min or more and 8 m / min or less.

When manufacturing a wiping sheet having a macroscopic pattern of concavo-convex portions on one surface, a high-pressure water stream is blown onto the fiber assembly 1A containing synthetic fibers in the pattern forming section 40 to macroscopically cover one surface of the fiber assembly. The uneven portion of the pattern can be formed (pattern forming step). The water pressure sprayed from the second water flow nozzle 41 and the transport speed of the fiber assembly can be set in the same range as in the entanglement step.

In this step, as shown in FIG. 3, a high-pressure water stream is sprayed from the second water stream nozzle 41 onto one surface of the fiber assembly 1A transported from the water stream entanglement section 30. At this time, the high-pressure water stream of the fiber assembly 1A is sprayed by arranging the concavo-convex portion forming member 50 having the structure as shown in FIG. 4, for example, between the fiber assembly 1A and the second support belt 42. The concave portion 3 and the convex portion 4 complementary to the concave-convex shape of the concave-convex portion forming member 50 can be formed on the surface opposite to the surface on which the concave-convex portion forming member 50 is formed. The uneven portion forming member 50 is made of metal, synthetic resin, or the like.

Specifically, the water flow blown from the second water flow nozzle 41 toward the upper surface side of the fiber assembly 1A presses the lower surface thereof so as to be in close contact with the upper surface of the concave portion forming convex portion 50a of the concave and convex portion forming member 50. .. At the same time, the synthetic fibers 2 that are the constituent fibers of the fiber assembly 1A located in the convex portion forming concave portion 50b of the concave and convex portion forming member 50 are projected into the concave portion 50b, and the concave portion forming member 50 for forming the concave portion is formed. The synthetic fiber 2 located on the convex portion 50a is depressed in the thickness direction of the aggregate. The water sprayed in the hydroentanglement is allowed to permeate downward through the convex portion forming concave portions 50b of the concave and convex portion forming member 50 and the drain holes 50c provided in plural in the concave portion forming convex portions 50a. As a result, it is possible to form a macroscopic pattern of irregularities having curved portions on one surface of the fiber assembly.

When forming a fiber assembly containing deformed fibers as synthetic fibers, the recesses 3 and the protrusions 4 formed in the pattern forming process have different orientations in the cross section of the deformed fibers. As shown in FIG. 5, in the portion where the concave portion forming convex portion 50a exists on the lower surface of the synthetic fiber 2 (that is, the portion where the concave portion 3 is formed in the fiber assembly 1A), the irregular shaped fiber having a relatively large surface area is formed. The flat surface is strongly pressed against one surface of the concave portion forming convex portion 50a by the water pressure of the high-pressure water flow W. As a result, the deformed fibers present in the recesses 3 are oriented such that the major axis in the cross section thereof is in the direction along the surface of the wiping sheet (major axis orientation). On the other hand, as shown in the same figure, in the portion where the convex portion forming concave portion 50b exists on the lower surface of the synthetic fiber 2 (that is, the portion where the convex portion 4 is formed in the fiber assembly 1A), exists in that portion. Since the profiled fiber can change its orientation in its cross section, the profiled fiber is oriented so that the major axis in the cross section of the profiled fiber is oriented along a plane orthogonal to the surface of the wiping sheet so as to be less susceptible to the resistance force by the high-pressure water flow W. (Short-axis orientation). In this way, the concave portions 3 and the convex portions 4 have different orientations in the cross section of the irregularly shaped fibers.

Finally, after the fiber assembly 1A manufactured through the above-described steps is formed into a rectangular shape as shown in FIG. 2, for example, the cleaning liquid spraying unit 60 impregnates the fiber assembly 1A with the cleaning liquid 5 (impregnation. Process), a wet wiping sheet can be used. The cleaning liquid spraying unit 60 can spray the cleaning liquid 5 onto the conveyed fiber assembly 1A. In this way, by spraying the cleaning liquid and impregnating the fiber aggregate, the amount of the cleaning liquid impregnated into the fiber aggregate can be adjusted to be in an appropriate range, and as a result, the production efficiency of the wiping sheet can be improved. Can be increased. In the impregnation step, it is possible to impregnate the fiber assembly 1A with the cleaning liquid 5 further containing at least one of the above-mentioned amphoteric surfactants, fragrances, additives, etc. to remove the oil and fat stains in the product, product stability, Also, it is preferable in that it has a cleaning feeling.

The wiping sheet manufactured in this manner is attached to a cleaning tool such as the wiping sheet alone or a wiper, and a building such as a floor surface, a wall surface, a cabinet, a window glass, a mirror, a door, a door knob, and the like, It can also be used for rugs, carpets, furniture such as desks, kitchens, toilets, body cleaning, hygiene products, and packaging.

In particular, since the wiping sheet of the present invention is impregnated with a cleaning liquid containing two kinds of nonionic surfactants having different HLB values, it is excellent in the efficiency of removing greasy stains adhering to cooking facilities such as floors and kitchens. It has become a thing. Examples of fat and oil stains include edible meats such as beef, pork, chicken, and sheep, and fats thereof, and meat-derived fats contained in milk and the like, fish-derived fats contained in fish, salad oil and rapeseed oil, sesame oil, and the like. Examples include vegetable oils derived from cooking oils and sebum derived from humans and pets. Even when these oils are modified and solidified, excellent removal efficiency is achieved. Further, the wiping sheet of the present invention, in addition to removing oil and fat stains, soy sauce, sauce, stains derived from ketchup, etc., carbohydrate stains derived from rice, etc., and removal of protein stains derived from eggs, etc. It is also excellent in the efficiency of removing fine particle stains and fiber stains such as hair that are present together with the stains. In addition to this, since the wiping sheet of the present invention does not perceive stickiness, slimyness, etc. due to the components of the cleaning liquid even after the surface to be cleaned after wiping is dried, a feeling of cleaning after use Will be excellent.

Although the present invention has been described based on the preferred embodiments thereof, the present invention is not limited to the above embodiments. For example, the wiping sheet of the present invention may be composed of only one fiber assembly containing synthetic fibers (whether single layer or multi-layered), or a variant of the first fiber assembly containing synthetic fibers. It may have a multi-ply laminated structure in which a second fiber aggregate with or without fibers or other sheet material other than the fiber aggregate is laminated. Examples of the sheet material include non-woven fabric, woven fabric, paper and the like.

In order to form a fiber assembly containing fibers other than synthetic fibers, for example, in the web forming unit 20, a second card machine is arranged and a web of other fibers is fed from the card machine. You may laminate. Then, by performing an entanglement step, a fiber assembly containing other fibers in addition to the synthetic fibers can be formed.

Regarding the above-described embodiment of the present invention, the following wiping sheet and a method for manufacturing the same are further disclosed.
<1>
A wiping sheet obtained by impregnating a cleaning liquid into a fiber assembly containing synthetic fibers,
The basis weight of the fiber assembly in a dry state is 50 g / m ² or more and 100 g / m ² or less,
The cleaning liquid contains at least two kinds of nonionic surfactants having different HLB values,
One of the surfactants has an HLB value of 12 or more and less than 15, and the other surfactant has an HLB value of 15 or more and 18 or less,
The cleaning solution is impregnated 205g / ^{m 2} or more 380 g / ^{m 2} or less, the wiping sheet.

<2>
The HLB value of one of the surfactants is more preferably 12.5 or more, further preferably 13 or more, more preferably 14.5 or less, further preferably 14 or less. The described wiping sheet.
<3>
The HLB value of the other surfactant is more preferably 15.5 or more, still more preferably 16 or more, and preferably 18 or less, more preferably 17.5 or less, still more preferably 17 or less, The wiping sheet according to <1> or <2>.
<4>
On the other hand, the surfactants include polyoxyethylene lauryl ether (HLB value: 12.1 to 14.9), polyoxyethylene cetyl ether (HLB value: 12.9 to 14.3), polyoxyethylene stearyl ether ( Any one of the above <1> to <3>, which is a polyoxyethylene alkyl ether such as HLB value: 12.8 to 13.9) and polyoxyethylene oleyl ether (HLB value: 12.1 to 13.6). The wiping sheet described in 1.
<5>
The other surfactant is a polyoxyethylene sorbitan fatty acid such as polyoxyethylene sorbitan monopalmitate (HLB value: 15.6) or polyoxyethylene coconut oil fatty acid sorbitan (HLB value: 15.0 to 16.7). The wiping sheet according to any one of <1> to <4>, which is an ester.

<6>
The wiping sheet according to any one of <1> to <5>, which preferably contains an amphoteric surfactant in addition to the two types of nonionic surfactants.
<7>
The amphoteric surfactant is at least one selected from lauryldimethylamine oxide, alkyl betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, and the like, the wiping sheet according to <6> ..
<8>
The cleaning liquid released from the wiping sheet has a pH at 25 ° C. of 7.8 or more and 9.0 or less,
The viscosity at 25 ° C. is 2 mPa · s or more and 10 mPa · s or less,
The wiping sheet according to any one of <1> to <7>, wherein the surface tension is 25 mN / m or more and 35 mN / m or less.
<9>
The wiping sheet according to <8>, wherein the cleaning liquid released from the wiping sheet further preferably has a pH at 25 ° C. of 8.0 or more.
<10>
The wiping sheet according to <8> or <9>, wherein the cleaning liquid released from the wiping sheet further preferably has a pH at 25 ° C. of 8.5 or less.

<11>
The wiping sheet according to any one of <1> to <10>, wherein the cleaning liquid contains a fragrance.
<12>
The fragrance is preferably one that dissolves in the cleaning liquid, and fragrance components such as menthol, geraniol, citronellal, citronellol, 1,8-cineole, terpineol, menthol, and linalool, rose fragrance, lavender fragrance, jasmine fragrance. The wiping sheet according to <11>, wherein the wiping sheet is at least one selected from the group consisting of fragrance compositions containing fragrances having a tone and a ylang-ylang scent.
<13>
The cleaning liquid contains 0.1% by mass or more and 0.5% by mass or less of the surfactant, respectively, and the total amount of the surfactants in the cleaning liquid is 0.2% by mass or more and 1.0% by mass or less. The wiping sheet according to any one of <1> to <12>.
<14>
The fiber assembly has a concavo-convex portion of a macroscopic pattern on at least one surface, and includes the synthetic fiber having a flat cross section,
In the concave portion and the convex portion forming the concave-convex portion, the synthetic fiber existing in the concave portion has a major axis of its cross section generally oriented in the direction along the surface of the wiping sheet, and the synthetic fibers existing in the convex portion. The wiping sheet according to any one of the items <1> to <13>, wherein the major axis of the cross section of the fiber is substantially in the direction along a plane orthogonal to the surface of the wiping sheet.
<15>
The wiping sheet according to any one of <1> to <14>, wherein a scrim net is arranged in a central region of the fiber assembly in the thickness direction.

<16>
The wiping sheet according to any one of <1> to <15>, which is used for wiping a hard surface.
<17>
A method of manufacturing a wiping sheet according to any one of <1> to <16>,
A method for producing a wiping sheet, comprising forming a fiber assembly containing synthetic fibers, and thereafter impregnating the fiber assembly with a cleaning liquid by spraying.
<18>
The method for manufacturing a wiping sheet according to <17>, wherein the fiber assembly mainly composed of the synthetic fiber is formed.
<19>
The content of synthetic fibers in the fiber assembly in a dry state is 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, to form the fiber assembly, <17> Alternatively, the method for producing the wiping sheet according to <18>.
<20>
The method for manufacturing a wiping sheet according to any one of <17> to <19>, wherein the cleaning agent containing an additive is impregnated into the fiber assembly.
<21>
As the additive, the cleaning agent containing at least one selected from the group consisting of fungicides, preservatives, fragrances, deodorants, pH adjusters, chelating agents, viscosity adjusters, solvents such as alcohols is used as the fiber assembly. The method for producing a wiping sheet according to <20>, wherein the body is impregnated.

<22>
The method for producing a wiping sheet according to any one of <17> to <21>, wherein the fiber assembly is formed by using synthetic fibers having a flat cross section.
<23>
Forming the fiber assembly, and then forming a concavo-convex portion in a macroscopic pattern on one surface of the fiber assembly, and thereafter impregnating the fiber assembly with the cleaning liquid, 22> The method for producing a wiping sheet according to any one of <22>.
<24>
A method of using a wiping sheet, which comprises wiping a hard surface using the wiping sheet according to any one of <1> to <16>.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the invention is not limited to such embodiments.

[Example 1]
As a synthetic fiber, a deformed fiber having a multilobe cross-sectional shape shown in FIG. 1 (b) is used to form a web, and the web is hydroentangled to make a scrim net (made of PP, wire diameter of about 200 μm, tsubo). A fiber assembly having an amount of 5 g / m ² ) in the central region in the thickness direction was produced. The fiber composition of the fiber assembly is a modified fiber (made of PET, fineness 1.7 dtex): a true circular fiber (made of acrylic, fineness 1.0 dtex): a flat fiber (made of rayon, fineness 1.7 dtex) = 70:15: 15 was included in a mass ratio, and the basis weight in a dry state was 70 g / m ² . After molding the fiber assembly to a size of 285 mm × 205 mm, the cleaning liquid was impregnated with 290 g / m ² to obtain a target wet wiping sheet.

The cleaning liquid contained 0.25 mass% of polyoxyethylene alkyl ether (HLB value: 13.6) as the first nonionic surfactant, and polyoxyethylene sorbitan fatty acid ester (HLB) as the second nonionic surfactant. Value: 16.7) was used as an aqueous solution containing 0.25% by mass. In this aqueous solution, 0.04% by mass of a fragrance, 0.07% by mass of a viscosity modifier (Carbopol ETD2020, manufactured by CBC Co., Ltd.), 0.05% by mass of lauryldimethylamine oxide as an amphoteric surfactant, and A pH adjuster (aminomethyl propanol) was further added to adjust the pH to 9.0. The pH of the cleaning liquid before impregnation at 25 ° C was adjusted using a pH measuring device (pH meter F22 manufactured by HORIBA).

[Example 2]
A wet wiping sheet was manufactured in the same manner as in Example 1 except that a cleaning liquid containing polyoxyethylene alkyl ether (HLB value: 12.1) was used as the first nonionic surfactant.

[Example 3]
A wet wiping sheet was produced in the same manner as in Example 1 except that a cleaning liquid containing polyoxyethylene sorbitan fatty acid ester (HLB value: 15.0) was used as the second nonionic surfactant.

[Comparative Example 1]
Example 1 except that a cleaning liquid containing a nonionic surfactant having an HLB value of less than 12 (polyoxyethylene alkyl ether, HLB value: 6.3) was used instead of the first nonionic surfactant. A wet wiping sheet was manufactured in the same manner as in.

[Comparative Examples 2 to 4]
Instead of the first nonionic surfactant, a nonionic surfactant having an HLB value of more than 15 (polyoxyethylene alkyl ether, HLB value: 16.2 (Comparative Example 2), 18.4 (Comparative Example 3) ), 18.5 (Comparative Example 4)) was used, and a wet wiping sheet was produced in the same manner as in Example 1.

[Comparative Examples 5 and 6]
Instead of the second nonionic surfactant, a nonionic surfactant having an HLB value of less than 15 (polyoxyethylene sorbitan fatty acid ester, HLB value: 9.6 (Comparative Example 5), 10.5 (Comparative Example A wet wiping sheet was produced in the same manner as in Example 1 except that the cleaning liquid containing 6)) was used.

[Comparative Example 7]
Instead of the first nonionic surfactant, a nonionic surfactant having an HLB value of less than 12 (polyoxyethylene alkyl ether, HLB value: 6.3) and a second nonionic surfactant were used instead. A wet wiping sheet was prepared in the same manner as in Example 1 except that a cleaning liquid containing a nonionic surfactant having an HLB value of less than 15 (polyoxyethylene sorbitan fatty acid ester, HLB value: 9.6) was used. Manufactured.

[Comparative Example 8]
Instead of the first nonionic surfactant, a nonionic surfactant having an HLB value of more than 15 (polyoxyethylene alkyl ether, HLB value: 18.5) and a second nonionic surfactant were used instead. Then, a wet wiping sheet was prepared in the same manner as in Example 1 except that a cleaning liquid containing a nonionic surfactant having an HLB value of less than 15 (polyoxyethylene sorbitan fatty acid ester, HLB value: 9.6) was used. Manufactured.

[Comparative Example 9]
A wet wiping sheet was produced in the same manner as in Example 1 except that a cleaning liquid containing no nonionic surfactant was used.

[Evaluation of pH]
The extract obtained by squeezing the wiping sheets of Examples and Comparative Examples was used as the cleaning liquid released from the wiping sheet. 30 mL of the cleaning liquid released from the wiping sheet was put into a beaker, and the pH of the cleaning liquid at 25 ° C was measured by a pH measuring device (pH meter F22, manufactured by HORIBA). The results are shown in Table 1.

[Evaluation of bubble height]
The foam height was evaluated by the loss miles method specified in JIS K3362. Using the cleaning liquid before impregnation, the heights of bubbles immediately after the measurement and 5 minutes after the measurement were visually measured. Each measurement was performed 3 times, and the arithmetic average value of each measurement value was defined as the foam height (mm). The results are shown in Table 1.

[Evaluation of viscosity]
The viscosity of the cleaning liquid was evaluated as follows. That is, 100 mL of the cleaning liquid discharged from the wiping sheet at 25 ° C. was placed in a beaker, and a low viscosity spindle (spindle No. M1) -attached VISCOMETER TVB-10 manufactured by Toki Sangyo Co., Ltd. The measurement was carried out under the condition of 60 rpm for 1 minute while being immersed in the sample. This measurement was performed 3 times, and the arithmetic average value of the respective measured values was taken as the viscosity (mPa · s). The results are shown in Table 1.

[Evaluation of surface tension]
The surface tension of the cleaning liquid was evaluated as follows. That is, a small petri dish containing 10 mL of the cleaning liquid discharged from the wiping sheet at 25 ° C. was placed on the measuring stage of the automatic surface tension meter CBVD-Z manufactured by Kyowa Interface Science Co., Ltd., and the upper spring of the device was measured. The platinum plate was lowered while the platinum plate was suspended in the area. The value when the force with which the platinum plate was pulled into the liquid sample when in contact with the liquid sample and the spring load were in equilibrium was measured. The measurement was performed 3 times, and the arithmetic mean value of the respective measured values was defined as the surface tension (mN / m). The results are shown in Table 1.

[Evaluation of stability]
The stability of the cleaning liquid was evaluated as follows. That is, 100 mL of the cleaning liquid before impregnation used in Examples and Comparative Examples was placed in a hermetically sealed container, hermetically sealed, and allowed to stand in a room temperature environment of 20 ° C to 25 ° C for 72 hours. Then, the presence or absence of a precipitate in the cleaning liquid was visually observed, and the stability of the cleaning liquid was evaluated according to the following criteria. The results are shown in Table 1 below.

<Stability evaluation criteria>
A: No wash deposits were confirmed, and the cleaning liquid has excellent stability.
B: Although it is cloudy, no precipitate is observed and the washing solution is stable.
C: A cleaning liquid in which a precipitate is confirmed and which lacks stability.

[Evaluation of oil and fat removability]
For the evaluation of oil and fat removability, (1) artificial sebum (model sebum dirt) and (2) cattle-derived oil as the oil and fat stains to be cleaned are the surfaces to be cleaned (flooring floors, product name: DAG floor, manufactured by Kitae Co., Ltd.). ) And wiped off each oil stain, the oil removal performance was visually evaluated according to the following criteria. The results are shown in Table 1.

<Evaluation criteria for oil and fat removability>
The following criteria were evaluated based on the change in gloss when visually observing the surface to be cleaned after the application of grease stains and the surface to be cleaned after wiping.
5: 90% or more of greasy dirt is removed, and the performance of greasy dirt is very excellent.
4: 60% or more and less than 90% of grease stains are removed, and the grease stain removal performance is excellent.
3: 40% or more and less than 60% of oil and fat stains are removed, and the oil and fat stain removal performance is not very good.
2: 10% or more and less than 40% of oil and fat stains are removed, resulting in poor oil and fat stain removal performance.
1: 10% or less of greasy dirt is removed, and the greasy dirt removal performance is very poor.

(1) Artificial Sebum 0.06 g of artificial sebum was applied to the surface to be cleaned of the flooring floor having a size of 14 cm × 14 cm. Using this wiping sheet of Examples and Comparative Examples, the floor surface was evaluated for the removal performance when it was wiped back and forth once along the width direction of the sheet. Wiping conditions were a load of 160 N / m ² and a speed of 1000 mm / sec.

(2) Fat derived from cattle Beef tallow and butter were mixed in a mass ratio of 1: 1 and heated to 180 ° C. for 30 minutes to be solidified and modified, and 1.0 g of the mixed fat was applied to the cleaning target surface of the flooring floor. Applied. Using this wiping sheet of the example and the comparative example, the floor surface was evaluated for the removal performance when the sheet was wiped three times in the width direction of the sheet according to the above evaluation criteria. The wiping conditions were as described above.

[Evaluation of cleaning feeling]
When wiping was performed using the wiping sheets of Examples and Comparative Examples, the cleaning feeling on the surface to be cleaned was evaluated according to the following criteria. The results are shown in Table 1.

<Evaluation criteria for cleaning feeling>
A: It has a high foaming property, and since it does not feel sticky or slimy after drying on the surface to be cleaned after wiping, it has a good cleaning feeling.
B: Poor foamability and lacking in cleaning feeling.

As shown in Table 1, it can be seen that the wiping sheet of the present invention has a high efficiency of removing oil stains such as sebum and animal oil, and can effectively remove solidified and modified oil stains. In addition to this, it is also understood that the wiping sheet of the present invention has a high cleaning feeling and does not feel sticky or slimy on the surface to be cleaned even after the surface to be cleaned is dried after wiping. On the other hand, the wiping sheet of the comparative example was inferior in oil and fat stain removal performance, and in addition to this, the stability of the cleaning liquid was poor and the cleaning feeling was inferior.

According to the present invention, it is possible to provide a wiping sheet capable of effectively removing solidification-modified oil and fat stains attached to a hard surface.

Claims (24)

1. A wiping sheet obtained by impregnating a cleaning liquid into a fiber assembly containing synthetic fibers,
   The basis weight of the fiber assembly in a dry state is 50 g / m 2 or more and 100 g / m 2 or less,
   The cleaning liquid contains at least two kinds of nonionic surfactants having different HLB values,
   One of the surfactants has an HLB value of 12 or more and less than 15, and the other surfactant has an HLB value of 15 or more and 18 or less,
   A wiping sheet impregnated with the cleaning liquid in an amount of 205 g / m 2 or more and 380 g / m 2 or less.
2. The wiping sheet according to claim 1, wherein one of the surfactants has an HLB value of 12.5 or more and 14.5 or less.
3. The wiping sheet according to claim 1 or 2, wherein the HLB value of the other surfactant is 15.5 or more and 17.5 or less.
4. On the other hand, the surfactants include polyoxyethylene lauryl ether (HLB value: 12.1 to 14.9), polyoxyethylene cetyl ether (HLB value: 12.9 to 14.3), polyoxyethylene stearyl ether ( A polyoxyethylene alkyl ether containing one or more selected from HLB value: 12.8 to 13.9) and polyoxyethylene oleyl ether (HLB value: 12.1 to 13.6). The wiping sheet according to any one of 1.
5. The other surfactant is at least one selected from polyoxyethylene sorbitan monopalmitate (HLB value: 15.6) and polyoxyethylene coconut oil fatty acid sorbitan (HLB value: 15.0 to 16.7). The wiping sheet according to any one of claims 1 to 4, which is a polyoxyethylene sorbitan fatty acid ester containing.
6. The wiping sheet according to any one of claims 1 to 5, which contains an amphoteric surfactant in addition to the two types of nonionic surfactants.
7. The wiping sheet according to claim 6, wherein the amphoteric surfactant is at least one selected from lauryl dimethylamine oxide, alkyl betaine, and 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine.
8. The cleaning liquid released from the wiping sheet has a pH at 25 ° C. of 7.8 or more and 9.0 or less,
   The viscosity at 25 ° C. is 2 mPa · s or more and 10 mPa · s or less,
   The wiping sheet according to any one of claims 1 to 7, which has a surface tension of 25 mN / m or more and 35 mN / m or less.
9. The wiping sheet according to claim 8, wherein the cleaning liquid released from the wiping sheet has a pH at 25 ° C of 8.0 or higher.
10. The wiping sheet according to claim 8 or 9, wherein the cleaning liquid released from the wiping sheet has a pH at 25 ° C of 8.5 or less.
11. The wiping sheet according to any one of claims 1 to 10, wherein the cleaning liquid contains a fragrance.
12. The fragrance is one that is soluble in a cleaning solution, and includes fragrance components such as menthol, geraniol, citronellal, citronellol, 1,8-cineole, terpineol, menthol, and linalool, rose fragrance, lavender fragrance, jasmine fragrance, and Iran. The wiping sheet according to claim 11, wherein the wiping sheet is at least one selected from the group consisting of a fragrance composition containing a fragrance having an Iran scent tone.
13. The cleaning liquid contains 0.1% by mass or more and 0.5% by mass or less of the surfactant, respectively, and the total amount of the surfactants in the cleaning liquid is 0.2% by mass or more and 1.0% by mass or less. The wiping sheet according to any one of claims 1 to 12.
14. The fiber assembly has a concavo-convex portion of a macroscopic pattern on at least one surface, and includes the synthetic fiber having a flat cross section,
    In the concave portion and the convex portion forming the concave-convex portion, the synthetic fiber existing in the concave portion has a major axis of its cross section generally oriented in the direction along the surface of the wiping sheet, and the synthetic fibers existing in the convex portion. The wiping sheet according to any one of claims 1 to 13, wherein the major axis of the cross section of the fiber is substantially oriented in a direction along a surface orthogonal to the surface of the wiping sheet.
15. The wiping sheet according to any one of claims 1 to 14, wherein a scrim net is arranged in a central region of the fiber assembly in the thickness direction.
16. The wiping sheet according to any one of claims 1 to 15, which is used for wiping a hard surface.
17. A method for manufacturing a wiping sheet according to any one of claims 1 to 16,
    A method for producing a wiping sheet, comprising forming a fiber assembly containing synthetic fibers, and thereafter impregnating the fiber assembly with a cleaning liquid by spraying.
18. The method for manufacturing a wiping sheet according to claim 17, wherein the fiber assembly mainly composed of the synthetic fiber is formed.
19. The method for producing a wiping sheet according to claim 17 or 18, wherein the fiber assembly in which the content of the synthetic fibers in the fiber assembly in the dry state is 50% by mass or more is formed.
20. The method for manufacturing a wiping sheet according to any one of claims 17 to 19, wherein the fiber assembly is impregnated with the detergent containing an additive.
21. As the additive, the cleaning agent containing at least one selected from the group consisting of fungicides, preservatives, fragrances, deodorants, pH adjusters, chelating agents, viscosity adjusters, solvents such as alcohols is used as the fiber assembly. The method for producing a wiping sheet according to claim 20, wherein the body is impregnated.
22. The method for manufacturing a wiping sheet according to any one of claims 17 to 21, wherein the fiber assembly is formed by using synthetic fibers having a flat cross section.
23. 23. The method of claim 17 or 22, wherein the fiber assembly is formed, and then a concavo-convex portion having a macroscopic pattern is formed on one surface of the fiber assembly, and thereafter, the cleaning liquid is impregnated into the fiber assembly. The method for manufacturing the wiping sheet according to any one of claims.
24. A method of using a wiping sheet for wiping a hard surface using the wiping sheet according to any one of claims 1 to 16.

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