JP6917242B2 - Wiping sheet and its manufacturing method - Google Patents

Description

The present invention relates to a wiping sheet and a method for producing the same.

Various attempts have been made to improve the function of the non-woven fabric by forming an uneven structure on the surface of the non-woven fabric. For example, Patent Document 1 describes a non-woven fabric which is composed of electrospinning integration of at least one of nanofibers and microfibers and has a concavo-convex micropattern at a predetermined position on a flat surface. There is. According to this non-woven fabric, it is described in the same document that the functional sophistication is achieved by the shape specificity due to the uneven micropattern structure, the cell affinity, the substance structure, etc. are improved, and the biological functionality can be adjusted. ing.

Patent Document 2 describes a non-woven fabric containing ultrafine fibers of 1 dtex or less and having irregularities on the surface. The surface of this non-woven fabric contains a fiber bundle in which a plurality of fibers are entangled with each other and a dent in the vicinity thereof. The number of ultrafine fibers in the fiber bundle is larger than the number of ultrafine fibers in the depression. It is described in the same document that this non-woven fabric is excellent in bulkiness, is flexible, and has a soft touch when touching a target surface.

Japanese Unexamined Patent Publication No. 2006-328562 Japanese Unexamined Patent Publication No. 2009-13544

By the way, a wiping sheet made of non-woven fabric is often used as an article for wiping a hard surface such as flooring or furniture. The above-mentioned Patent Document 1 describes a technique related to a non-woven fabric, and the non-woven fabric described in the same document is intended for application to medical devices such as regenerative medicine, and is used for cleaning and cleaning. No mention is made of the functionality of the non-woven fabric.

When the non-woven fabric having the uneven structure described in Patent Document 2 is used as a cleaning product, the frictional resistance between the non-woven fabric and the object to be cleaned becomes large due to the fact that the non-woven fabric contains small diameter fibers. Therefore, the operability of the non-woven fabric at the time of cleaning may be inferior.

Therefore, an object of the present invention is to provide a wiping sheet in which the frictional resistance with the wiping object is reduced and the operability at the time of wiping is improved.

The present invention includes a first fiber and a second fiber having a diameter smaller than that of the first fiber, includes a fiber aggregate formed by entanglement of these fibers, and has a first surface used as a wiping surface. , A wiping sheet having a second surface located on the opposite side of the first surface.
The abundance ratio of the second fiber is higher in the first surface than in the second surface.
A plurality of convex portions are formed on the first surface side.
The abundance ratio of the first fiber at the top to the entire fibers constituting the convex portion is higher than the abundance ratio of the second fiber.
The present invention provides a wiping sheet in which the abundance ratio of the second fiber in the hem portion with respect to the entire fiber constituting the convex portion is higher than the abundance ratio of the first fiber.

Further, the present invention provides a suitable method for manufacturing the wiping sheet.
A laminate of a fiber aggregate of the first fiber and a fiber aggregate of a second fiber having a diameter smaller than that of the first fiber, and a convex portion in which the fiber aggregate of the second fiber has a plurality of openings. Under the state of being arranged so as to face the forming member, a water stream is sprayed from the side of the fiber aggregate of the first fiber to entangle the first fiber and the second fiber, and the position is located at the opening. The present invention provides a method for producing a wiping sheet in which the fiber aggregate is projected into the opening.

According to the present invention, there is provided a wiping sheet and a method for manufacturing the same, in which the frictional resistance at the time of wiping is reduced and the operability at the time of wiping is improved.

FIG. 1 is an enlarged view of a main part of a convex portion in the wiping sheet of the present invention. FIG. 2 is a schematic view of the wiping sheet manufacturing apparatus of the present invention. FIG. 3 is a plan view of an embodiment of the convex portion forming member used in the present invention. FIG. 4 is an enlarged view of a main part showing a process of manufacturing the wiping sheet of the present invention. FIG. 5 is a cross-sectional view taken along the line AA in FIG. FIG. 6 is a plan view of another embodiment of the convex portion forming member used in the present invention. FIG. 7 is an enlarged view of a main part (corresponding to FIG. 4) showing another step of manufacturing the wiping sheet of the present invention. FIG. 8 is a cross-sectional view taken along the line BB in FIG. FIG. 9 is a graph of the frictional resistance value of the wet wiping sheet in Example 1 and Comparative Example 1. FIG. 10 is a graph of the frictional resistance values of the dry wiping sheets in Example 2 and Comparative Examples 2 and 3.

Hereinafter, the wiping sheet of the present invention will be described based on its preferred embodiment. In the present invention, wiping includes both meanings of cleaning and cleaning, for example, cleaning of buildings such as floors, walls, ceilings and pillars, cleaning of fittings and fixtures, wiping of articles, body and body. Includes cleaning of equipment related to.

The wiping sheet of the present invention is made of a fiber aggregate. The fibers constituting the fiber aggregate include at least a first fiber and a second fiber having a diameter smaller than that of the first fiber. The first fiber and the second fiber are entangled with each other by the first fiber, the second fiber, and the first fiber and the second fiber to form the above-mentioned fiber aggregate. A wiping liquid may be supported on the fiber aggregate. The wiping liquid and its supporting method will be described in detail later. In addition, in this specification, the term "wiping sheet" simply refers to one in which a wiping liquid is supported and one in which a wiping liquid is not supported, depending on the context.

The fiber aggregate used in the wiping sheet 10 is a fiber aggregate that is composited mainly by entanglement of the first and second fibers. Here, the wiping surface of the wiping sheet 10 is also referred to as a front surface or a first surface, and a surface opposite to the wiping surface is also referred to as a back surface or a second surface.

FIG. 1 shows an enlarged part of a vertical cross section of an embodiment of the wiping sheet of the present invention. As shown in the figure, the wiping sheet 10 is composed of the first fiber 20 and the second fiber 40. Further, the wiping sheet 10 has a first surface 50Y and a second surface 50X located on the opposite side of the first surface 50Y. The first surface 50Y of the wiping sheet 10 is provided as a wiping surface when the wiping sheet 10 is used. As shown in FIG. 1, a fiber aggregate of the second fiber 40, which is a fiber having a small fiber diameter, exists on the upper side of the figure, and this is a wiping surface. Therefore, the lower side of the figure is the opposite side and the back side of the wiping surface.

The wiping sheet 10 projects from the second surface 50X toward the first surface 50Y side, whereby the convex portion 50A is formed. A plurality of convex portions 50A are formed over the surface direction of the wiping sheet 10. The convex portion 50A has a shape in which the first surface 50Y of the wiping sheet 10 is raised from the flat surface 50Y'. On the second surface 50X side, the region corresponding to the convex portion 50A is recessed from the flat surface 50X'on the second surface 50X toward the first surface 50Y to form the concave portion 50C. Depending on the method of manufacturing the wiping sheet 10, the entire surface of the second surface 50X may be a flat surface. In this specification, the description regarding the first surface 50Y (wiping surface) does not include the convex portion 50A.

Each convex portion 50A is a solid one whose inside is filled with the first fiber 20 and / or the second fiber 40. The shape and size of each convex portion 50A may be the same or different. Considering the ease of manufacturing the wiping sheet 10, it is preferable that the shape and size of each convex portion 50A are the same.

Each convex portion 50A can be regularly arranged or irregularly arranged on the first surface 50Y side of the wiping sheet 10. When each convex portion 50A is regularly arranged on the first surface 50Y, for example, it can be regularly arranged along the longitudinal direction of the wiping sheet 10 and / or along the width direction. Regardless of whether the convex portions 50A are arranged regularly or irregularly, the wiping sheet is formed by forming a plurality of convex portions 50A on the first surface 50Y side, which is the wiping surface. When the wiping operation using the 10 is performed, the frictional force between the wiping target surface and the wiping sheet 10 can be effectively reduced, and the wiping operation can be easily performed.

As shown in FIG. 1, in the vertical cross-sectional view of the wiping sheet 10, the locations where the first fibers 20 and the second fibers 40 are present are unevenly distributed. Specifically, in the wiping sheet 10, the abundance ratio of the second fiber 40 is higher in the first surface 50Y, which is the wiping surface, than in the second surface 50X, which is the surface opposite to the wiping surface. .. By adopting this configuration, the wiping effect of the wiping sheet 10 can be enhanced in combination with the fact that a plurality of convex portions 50A are formed on the first surface 50Y side.

As described above, in the wiping sheet 10, the abundance ratio of the second fiber 40 is higher on the wiping surface than on the surface opposite to the wiping surface. At the same time, focusing on the first surface 50Y, which is the wiping surface, the convex portion 50A formed on the first surface 50Y side has a convex portion 50A at the top 50T with respect to the entire fiber constituting the convex portion 50A. The abundance ratio of the fiber 20 of 1 is higher than the abundance ratio of the second fiber 40. On the other hand, in the hem portion 50B of the convex portion 50A, the abundance ratio of the second fiber 40 in the hem portion 50B with respect to the entire fibers constituting the convex portion 50A is higher than the abundance ratio of the first fiber 20. By making the abundance ratios of the first and second fibers 20 and 40 constituting the convex portion 50A in this way, surprisingly, the frictional force between the wiping target surface and the wiping sheet 10 is effectively effective. It turned out that it can be reduced.

The frictional force between the surface to be wiped and the wiping sheet 10 is preferably 5N or less when the wiping sheet 10 having a size of 10 cm × 25 cm is wiped by applying a pressure of 55 N ^{/ m 2.} It is more preferably less than or equal to 4N or less. The lower limit of the resistance is not particularly limited, and the lower the value, the more preferable. However, if the resistance is as low as about 0.8 N, the wiping operation can be smoothly performed.

Specifically, the resistance force at the time of wiping is measured by the following method. The head of a quickle wiper (manufactured by Kao Corporation) with an alligator-shaped clip attached to the tip of a push-pull gauge (RX-20, manufactured by Aiko Engineering Co., Ltd.) and a wiping sheet with a size of 285 mm x 205 mm attached to the clip. To install. The maximum load recorded on the push-pull gauge when this head portion is scanned for 1 m at a speed of 1 cm / sec on a flooring (Combit New Advance 101, manufactured by Wood One Co., Ltd.) is measured as a resistance force.

The top portion 50T of the convex portion 50A is a region from the apex of the convex portion 50A to (1/3) H, where H is the height of the convex portion 50A. On the other hand, the hem portion 50B of the convex portion 50A is a region from the flat surface 50Y'to (1/3) H on the first surface 50Y.

From the viewpoint of more effectively reducing the frictional force between the surface to be wiped and the wiping sheet 10, the abundance ratio of the first fiber 20 and the second fiber 40 in the top 50T of the convex portion 50A is the convex portion 50A. It is preferable that the number of the first fiber is three times or more that of the second fiber based on the number of fibers as a whole. From the same viewpoint, the abundance ratio of the first fiber 20 and the second fiber 40 in the hem portion 50B of the convex portion 50A is such that the second fiber is the second fiber based on the number of fibers constituting the convex portion 50A. The number of fibers is preferably twice or more that of one fiber.

The frictional force between the wiping target surface and the wiping sheet 10 may also depend on the shape of the convex portion 50A. From the viewpoint of more effectively reducing the frictional force, the width W of the convex portion 50A is preferably 400 μm or more, more preferably 800 μm or more, and further preferably 900 μm or more. Further, the width W is preferably 10 mm or less, more preferably 8 mm or less, and further preferably 5 mm or less. The width W is preferably 400 μm or more and 10 mm or less, more preferably 800 μm or more and 8 mm or less, and further preferably 900 μm or more and 5 mm or less. As shown in FIG. 1, the width W is measured starting from a position where the convex portion 50A starts to rise from the flat surface 50Y'on the first surface 50Y of the wiping sheet 10.

From the same viewpoint, the height H of the convex portion 50A is preferably 110 μm or more, more preferably 500 μm or more, and further preferably 900 μm or more. Further, the height H is preferably 25 mm or less, more preferably 20 mm or less, and further preferably 18 mm or less. The height H is preferably 110 μm or more and 25 mm or less, more preferably 500 μm or more and 20 mm or less, and further preferably 900 μm or more and 18 mm or less. As shown in FIG. 1, the height H is the distance from the flat surface 50Y'on the first surface 50Y of the wiping sheet 10 to the apex of the convex portion 50A.

The formation density of the convex portion 50A on the first surface 50Y side may also affect the frictional force between the wiping target surface and the wiping sheet 10. From the viewpoint of more effectively reducing the frictional force, when a virtual circle having a diameter of 20 mm is drawn at an arbitrary position on the first surface 50Y, the number of convex portions 50A existing in the virtual circle is 10 or more. It is preferable, the number is more preferably 15 or more, and the number is even more preferably 20 or more. The number of convex portions 50A is preferably 60 or less, more preferably 50 or less, and even more preferably 40 or less. The number of convex portions 50A is preferably 10 or more and 60 or less, more preferably 15 or more and 50 or less, and further preferably 20 or more and 40 or less.

The wiping sheet 10 of the present invention may have a mode in which the wiping liquid is not supported as a dry type (hereinafter, this mode is also referred to as a "dry wiping sheet"), or a wiping liquid as a wet type. (Hereinafter, this aspect is also referred to as a "wet wiping sheet"). When the wiping sheet 10 of the present invention is a wet wiping sheet, it is preferable that the wiping liquid is at least supported on the fiber aggregate located on the second surface side. In addition, supporting at least the wiping liquid on the fiber aggregate whose wiping surface is located on the second surface side means that the fiber aggregate on the opposite side of the wiping surface contains the wiping liquid, and the fiber aggregate on the wiping surface side. The body also includes an embodiment in which the wiping liquid is contained in the voids. It should be noted that preferably, the amount of the wiping liquid supported is larger than the amount of the wiping liquid supported on the fiber aggregate on the opposite side of the wiping surface.

In particular, when the wiping sheet 10 of the present invention is a wet wiping sheet, in addition to the above-mentioned plurality of convex portions 50A being formed, the first fibers 20 at the top 50T and the hem 50B of the convex portions 50A are formed. When wiping, the abundance ratio of the second fiber 40, the width W and height H of the convex portion 50A on the first surface 50Y side, and / or the formation density of the convex portion 50A satisfy a specific range. It is advantageous in that the effect of reducing the frictional resistance in the above becomes even more remarkable.

From the viewpoint of further enhancing the wiping effect of the wiping sheet 10 in combination with the formation of a plurality of convex portions 50A, and from the viewpoint of being able to stably support a large amount of wiping liquid when the wet wiping sheet 10 is used. Of the surfaces of the wiping sheet 10 including voids, the area ratio of the second fiber on the wiping surface is preferably 40% or more and 99% or less, more preferably 45% or more and 95% or less, and 50% or more and 90%. The following is more preferable. On the other hand, the area ratio occupied by the second fiber on the surface opposite to the wiping surface is preferably 0% or more and 55% or less. The area occupied by the second fiber on the wiping surface is determined, for example, by measuring the area occupied by the fiber having a small fiber diameter from an image or a photograph of the wiping surface. Hereinafter, the area occupied by the fibers can be obtained in the same manner as described above. Therefore, the area ratio is a value obtained by dividing the area occupied by the fibers by the area to be measured. In the case of% display, it is 100 times the value obtained by dividing.

Here, for example, the remaining 1% of the upper limit of 99% in the area ratio of 40% or more and 99% or less is a void. This gap is necessary for the wiping liquid to be discharged to the wiping surface when the wet wiping sheet 10 is used. By adjusting the ratio of the voids, the amount of wiping liquid released to wipe off the dirt on the surface to be wiped can be suppressed to the required amount even if the wiping sheet 10 is used, especially when a wet wiping sheet 10 is used. can. Further, by setting the area ratio occupied by the second fiber on the surface opposite to the wiping surface as described above, the number of voids is increased as a result, and the amount of the wiping liquid supported on the wet wiping sheet 10 is increased. If the area ratio of the second fiber on the wiping surface is too small, the wiping liquid will be released in an amount larger than necessary. Therefore, the area that can be wiped becomes narrow.

In the wiping sheet 10, the area ratio occupied by the second fiber 40 on the surface parallel to the wiping surface decreases stepwise, curvedly, or a combination thereof toward the thickness direction on the opposite side of the wiping surface. It is preferable to do. In particular, from the surface opposite to the wiping surface, 50% or more and 100% or less of the thickness of the wiping sheet 10 is set, and the area ratio occupied by the second fiber 40 is in the range of 50% or more and 100% or less. When the wiping sheet 10 is used, the amount of the wiping liquid supported can be increased. Here, the ratio of the thickness in which the area ratio occupied by the second fiber 40 is in the range of 50% or more and 100% or less is preferably 1% or more and 90% or less, more preferably 5% or more and 70% or less. More preferably, it is 7% or more and 50% or less. By setting the ratio of the thickness to a preferable value as described above, it is possible to release a required amount of the wiping liquid released to wipe off the dirt on the surface to be wiped when the wet wiping sheet 10 is used. As shown in FIG. 1, the thickness of the wiping sheet 10 is the distance T from the surface opposite to the wiping surface to the apex of the convex portion 50A.

Here, a confocal laser scanning microscope can be used to obtain information on the inside of the wiping sheet 10. By using a confocal laser scanning microscope, a spectrum inside the sample can be obtained. For example, by Raman imaging the sample in the depth direction, the component distribution inside the sample can be observed nondestructively.

The wet wiping sheet 10 is composed of at least two layers, a liquid retention layer that supports the wiping liquid and a release layer of the wiping liquid, and the release layer includes a wiping surface. In particular, in order to support a large amount of wiping liquid, as described above, the area ratio of the second fiber occupying 50% or more and 100% or less of the thickness of the wiping sheet 10 from the surface opposite to the wiping surface. Is 1% or more and 100% or less. This makes it possible to form a liquid-retaining layer that supports most of the wiping liquid. On the other hand, the release layer is a portion other than the liquid retention layer including the wiping surface.

In the wiping sheet 10, it is preferable that the capillary pressure on the wiping surface side is higher than that on the opposite side of the wiping surface. Thereby, especially when used as a wet wiping sheet 10, the amount of wiping liquid released to wipe off the dirt on the surface to be wiped can be controlled to a required amount even if the wiping is strongly wiped. Therefore, even in the case of wiping with a large wiping area such as a rug, carpet, or floor, it is not necessary to replace the wiping sheet 10 with a new one during wiping, or the number of replacements can be reduced.

Here, it is known that the capillary pressure follows the following relationship.
Pc = 2kγ _L / r × cosθ
In the formula, Pc is the capillary pressure (N / m ² ) of the _{fiber aggregate, γ L} is the surface tension of the liquid (N / m), and θ is the contact angle (rad) between the fiber and the liquid. r is the fiber diameter (m) and k is the correction coefficient.

The Pc derived by the above formula is a value using the summary statistic derived from the measurement of the fiber aggregate. In order to measure Pc, it is necessary to measure the surface tension of the liquid, the fiber diameter, the contact angle between the fiber and the liquid, and the correction coefficient. The surface tension is an automatic surface tension meter based on the plate method such as DY-200 manufactured by Kyowa Interface Science Co., Ltd., at 20 ° C. and 65% R.M. H. The average value measured 10 times in the environment of. The fiber diameter is measured by observing with a scanning electron microscope and measuring 30 fibers per observation at an observation magnification of 350 times, and this is taken as an average value obtained by measuring 150 fiber diameters at a total of 5 locations at random. For the contact angle between the fiber and the liquid, the constituent fibers of the fiber aggregate are identified by Fourier transform infrared spectroscopy (FTIR), and the contact angle on the resin plate having the same composition is measured. Specifically, the contact angle when 3 seconds have passed after dropping 1 μL with a fully automatic contact angle meter such as DMo-901 manufactured by Kyowa Interface Science Co., Ltd. is measured at 5 points on the plate and used as the average value. .. If there are multiple fiber materials, the contact angle is measured in the same way for each material, and the value at the time of Pc calculation is the weighted average of the contact angles based on the surface area ratio of each fiber component. Let it be θ in. The correction coefficient is obtained by measuring the Krem water absorption degree specified in JIS P 8141, measuring the water absorption weight of the liquid from the water absorption height, and dividing the water absorption weight by the total amount of the capillary cross sections constituting the non-woven fabric. The correction coefficient k is calculated from the Pc measured in this way from which the pressure Pc can be derived.

As is clear from the above formula, the smaller the fiber diameter, the higher the capillary pressure. In the wiping sheet 10, the capillary pressure on the wiping surface side is increased by reducing the fiber diameter.

The fibers constituting the wiping sheet 10 are at least two types of fibers having different fiber diameters. Typical fibers are polyester, polyamide, polyolefin, cellulose fibers, and fibers made from various metals, glass, and minerals. Of these, polyester, polyamide, polyolefin, and cellulose fibers are preferable.

The polyester may be any polyester as long as it has a structure having an ester bond in the polymer main chain. For example, polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN) can be mentioned.

Polyolefins are obtained from monomers having ethylenically unsaturated groups. Examples thereof include polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, cyclic acetal of polyvinyl alcohol, acrylic resin (including acrylic resin and methacrylic resin), and polyvinyl chloride. As described above, the polyolefin may be a homopolymer or a copolymer.

The polyamide may be any polyamide as long as it has a structure having an amide bond in the polymer main chain. For example, polycondensation nylon such as nylon 6, nylon 11, nylon 12 and cocondensation nylon such as nylon 66, nylon 610, nylon 612, nylon 6T, nylon 6I, nylon 9T, and nylon M5T can be mentioned. Moreover, the polyamide obtained by the following diamine component and a dicarboxylic acid component can be mentioned.

Diamine components include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl. Examples thereof include aliphatic diamine compounds such as −hexamethylenediamine and 2,4,4-trimethylhexamethylenediamine. In addition, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2 Examples thereof include alicyclic diamine compounds such as -bis (4-aminocyclohexyl) propane, bis (aminomethyl) decalin, and bis (aminomethyl) tricyclodecane. Further, examples thereof include diamine compounds having an aromatic ring such as metaxylylenediamine, paraxylylenediamine, bis (4-aminophenyl) ether, para-phenylenediamine and bis (aminomethyl) naphthalene.

Examples of the carboxylic acid component include aliphatic dicarboxylic acid compounds such as succinic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, adipic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid. Further, phthalic acid compounds such as isophthalic acid, terephthalic acid and orthophthalic acid can be mentioned. Further, 1,2-naphthalenedicarboxylic acid, 1,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 1,7-naphthalenedicarboxylic acid, Examples thereof include naphthalenedicarboxylic acid compounds such as 1,8-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid and 2,7-naphthalenedicarboxylic acid.

These diamine components and dicarboxylic acid components, including nylons, may be used alone or in combination.

The cellulose fiber may be a natural fiber or a synthetic fiber, and examples of the synthetic fiber include an acylate fiber such as an acetate of cellulose.

Further, these mixed fibers, for example, polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate and the like can also be mentioned.

In the present invention, among the above fibers, polyethylene terephthalate, polypropylene, acrylic resin, nylons and cellulose fibers are more preferable. Acrylic resins (particularly, acrylic acid preferably has its ester, methacrylic acid or a repeating unit obtained from the ester.

The fiber length of the fiber, that is, the average fiber length of the entire fiber used in the present invention depends on the method for producing the fiber, but is generally preferably 1 mm or more and 100 mm or less, more preferably 10 mm or more and 90 mm or less, and further preferably 20 mm or more and 60 mm or less. ..

The diameter of the first fiber 20 is preferably 10 μm or more and 30 μm or less, and more preferably 15 μm or more and 25 μm or less. On the other hand, the diameter of the second fiber 40 is preferably 0.1 μm or more and 9 μm or less, and more preferably 0.5 μm or more and 5 μm or less.

The fibers having different fiber diameters may be fibers having the same composition or fibers having different components, but in the present invention, fibers having the same composition are preferable. Further, the fiber lengths may be different or the same for each other, but in the present invention, fibers having the same fiber length are preferable.

The basis weight of the fibers constituting the wiping sheet 10 ^{is preferably 1 g / m 2} or more and 100 g / m ² or less, more preferably 5 g / m ² or more and 50 g / m ² or less, and 10 g / m ² or more and 30 g / m. ² or less is more preferable. On the other hand, on the surface opposite to the wiping surface, 10 g / m ² or more and 50 g / m ² or less is preferable, 15 g / m ² or more and 30 g / m ² or less is more preferable, and 20 g / m ² or more and 25 g / m ² or less is further preferable. preferable.

The thickness T of the wiping sheet 10 is preferably 1 mm or more, more preferably 1.2 mm or more, and more preferably 1.5 mm or more under a load of 40 Pa, in relation to the basis weight of the fibers constituting the wiping sheet 10. It is more preferable to have. Further, under the same load, it is preferably 5 mm or less, more preferably 4 mm or less, and even more preferably 3 mm or less. The thickness T of the wiping sheet 10 is preferably 0.8 mm or more and 3 mm or less under a load of 370 Pa, more preferably 0.9 mm or more and 2.8 mm or less, and further preferably 1 mm or more and 2.5 mm or less. preferable. By setting the thickness T of the wiping sheet 10 within this range, the wiping sheet 10 has sufficient rigidity and strength, and the operability at the time of wiping is improved.

In the present invention, it is particularly preferable that fibers having different fiber diameters are entangled with each other without heat fusion. By doing so, the voids between the fibers are increased as compared with the case of heat fusion. As a result, when the wiping liquid is supported on the wiping sheet 10, the amount of the wiping liquid supported increases.

In the wet wiping sheet 10, the amount of wiping liquid released from the wiping surface to the wiping target surface by wiping once, that is, by wiping the wiping target surface once is preferably 0.5 g / tatami or more, and is 0. 7. 7 g / tatami or more is more preferable, and 1.0 g / tatami or more is further preferable. The upper limit of the amount released is realistically 8 g / tatami or less, preferably 7 g / tatami or less, and more preferably 6 g / tatami or less. If the amount released is too small, it cannot be wiped sufficiently, and if it is too large, the wiping liquid tends to remain on the wiping surface. Here, the tatami mat is 1820 mm × 910 mm and has an area of 1.6552 m ² .

The measurement conditions for the release behavior are a wiping load (load W) of 0.16 kN / m ² and a wiping speed (speed V) of 1 m / s. In the wiping sheet of the present invention, when the wiping liquid is supported, the amount released per tatami mat when measured under such measurement conditions is within the above range.

The maximum amount of liquid supported on the wiping sheet 10 by the wiping liquid, that is, the initial amount of liquid supported is 1 g when the dimensions of one wiping sheet 10 are 285 mm × 205 mm as described in Examples described later. / Sheet or more is preferable, 10 g / sheet or more is more preferable, and 12 g / sheet or more is further preferable. The initial upper limit of the amount of the liquid supported is realistically 40 g / sheet or less, preferably 30 g / sheet or less, and more preferably 20 g / sheet or less.

By doing so, it is possible to release a liquid amount of 1 g / tatami or more per target wiping, and it is possible to maintain the 6th tatami or more.

The wiping liquid used for the wiping sheet 10 is generally the same as that used for the wet wiping sheet. That is, the wiping liquid may be water alone or an aqueous solution containing a surfactant, but an aqueous solution containing a surfactant is preferable.

The surfactant may be any of a nonionic surfactant, an amphoteric surfactant, a cationic surfactant or an anionic surfactant. For example, an anionic surfactant such as alkylbenzene sulfonic acid or a nonionic surfactant such as polyoxyethylene alkyl ether can be used.

The wiping solution may contain additives. Examples of the additive include a polymer of acrylic acid, methacrylic acid or maleic acid or a salt thereof, and a copolymer of maleic acid and another vinyl-based monomer or a salt thereof for the purpose of enhancing the rinsing effect. Can be mentioned. Examples thereof include bactericides, fragrances, air fresheners, deodorants, abrasive particles, pH adjusters, and water-soluble organic solvents such as alcohol.

The content of surfactants and additives as described above is generally in the range used in wet wiping sheets.

Next, a suitable manufacturing method of the wiping sheet 10 shown in FIG. 1 will be described with reference to FIGS. 2 to 8. FIG. 2 shows a manufacturing apparatus 1 preferably used for manufacturing the wiping sheet 10. The manufacturing apparatus 1 includes a web forming portion 2, an entangled portion 3, an electrostatic spinning portion 4, and a convex portion forming portion 5.

The web forming portion 2 forms the web of the first fiber 20. The web forming unit 2 includes a card machine 21 that forms a web from the first fiber 20 that is a raw material of the wiping sheet 10.

The entangled portion 3 entangles the web of the first fiber 20 with a water stream. The entangled portion 3 includes a first water flow nozzle 31 that blows a water flow onto the web of the first fiber 20, and a first support belt 32 composed of an endless belt. The first water flow nozzle 31 is located above the web of the first fiber 20 and the first support belt 32, and can blow a high-pressure water flow over the entire width direction of the web of the first fiber 20. ing. The first support belt 32 is arranged so as to face the first water flow nozzle 31, and has a structure in which holes are formed in a pattern such as a grid pattern in order to allow the sprayed water to pass through (not shown). ). The entangled body of the first fibers 20 entangled by spraying the water flow from the first water flow nozzle 31 is conveyed to the electrostatic spinning section 4 by the first support belt 32.

The electrostatic spinning unit 4 generates a second fiber 40 made of nanofibers by an electrostatic spinning method and deposits it on one surface of an entangled body of the first fiber 20 entangled by a water flow nozzle 31 of the entangled unit 3. Is. The electrostatic spinning unit 4 includes an injection unit 41 that injects the raw material liquid of the second fiber 40 and electrostatically spins the raw material liquid, and a collecting electrode 42 that collects the injected raw material liquid as the second fiber 40. ing. The injection unit 41 is composed of a supply unit for the raw material liquid of the second fiber 40, an electrode, a voltage application unit, and the like (not shown). A positive voltage or a negative voltage is applied to the injection unit 41. The collection electrode 42 is arranged so as to face the injection unit 41. The collection electrode 42 is made of a conductive member and is grounded.

When a voltage is applied to the injection unit 41, the raw material liquid of the second fiber 40 is charged by electrostatic induction until it is injected from the injection unit 41, and is injected in a charged state. The raw material liquid injected in the charged state causes self-repulsion of the raw material liquid due to the action of the electric field, and the second fiber 40 is generated as fine fibers (nanofibers) at the nano size level. The generated second fiber 40 is randomly deposited on one surface of the entanglement of the first fiber 20 running in the vicinity of the collection electrode 42 to form a fiber aggregate. By this electrostatic spinning step, a laminated body 50 of a fiber aggregate composed of a first fiber 20 and a second fiber 40 is formed. The obtained laminated body 50 is conveyed to the convex portion forming portion 5.

As the raw material liquid of the second fiber 40 in the electrostatic spinning method, a liquid in which the polymer compound constituting the second fiber 40 is dissolved or dispersed in a solvent, or a melt in which the polymer compound is melted can be used. .. A method using a liquid in which a polymer compound is dissolved or dispersed in a solvent can also be referred to as a solution-type electrostatic spinning method, and a method using a melt obtained by melting a polymer compound can also be referred to as a melt-type electrostatic spinning method. .. In the present invention, any electrostatic spinning method can be used.

In the convex portion forming portion 5, a water stream is sprayed on the fiber aggregate of the first fiber 20 and the laminate 50 of the fiber aggregate of the second fiber 40 to entangle the first fiber and the second fiber. Form a convex part. The convex portion forming portion 5 includes a second water flow nozzle 51 that blows a water flow from the first fiber 20 side onto the laminated body 50, and a convex portion forming member 52 that forms a convex portion on the second fiber 40 side by the water flow. It is composed of a second support belt 53 provided below the convex portion forming member 52 and a transport belt 54 for transporting the laminated body 50 on which the convex portion is formed to a downstream manufacturing process.

As shown in FIG. 2, the second water flow nozzle 51 is located on the first fiber 20 side of the laminated body 50, and can blow water flow over the entire width direction of the laminated body 50. The convex portion forming member 52 is located below the laminated body 50 and is arranged so as to face the fiber aggregate of the second fiber. As shown in FIG. 3, a plurality of circular opening portions 52a are regularly formed in the convex portion forming member 52 over the entire area thereof. The convex portion forming member 52 is not particularly limited as long as it has an open portion, and a punching metal, a plastic net, or the like can be used. The shape of the hole 52a is also not particularly limited, and may be an ellipse, a triangle, a quadrangle, a pentagon, or the like, in addition to the circle shown in FIG. The convex portion forming member 52 may be integrated with the second support belt 53 by means such as sewing or adhesion.

As shown in FIGS. 2 and 4, the water flow sprayed from the second water flow nozzle 51 toward the surface 50X on the first fiber 20 side forms a convex portion on the surface 50Y on the second fiber 40 side of the laminate 50. It is pressed against the upper surface of the member 52 so as to be in close contact with it. At the same time, the fiber aggregates of the first fiber 20 and the second fiber 40 located in the opening portion 52a are projected into the opening portion 52a to form a plurality of convex portions 50A. At this time, the first fiber 20 and the second fiber 40 are separated, and in the top 50T of the convex portion 50A, the abundance ratio of the first fiber 20 in the top 50T with respect to the entire fibers constituting the convex portion 50A is determined. It is higher than the abundance ratio of the second fiber 40. At the same time, in the hem portion 50B of the convex portion 50A, the abundance ratio of the second fiber 40 in the hem portion 50B with respect to the entire fibers constituting the convex portion 50A is higher than the abundance ratio of the first fiber 20. By these steps, it is possible to obtain a laminated body 50 in which a plurality of convex portions 50A are formed.

As shown in FIG. 5, the width L of the opening portion 52a in the convex portion forming member 52 is preferably 400 μm or more and 10 mm. By having this width L, it is possible to form the convex portion 50A having a good appearance and capable of reducing the resistance at the time of wiping in the laminated body 50.

As shown in FIG. 5, the thickness T of the convex portion forming member 52 is preferably 800 μm or more and 3 mm or less, and more preferably 900 μm or more and 2 mm or less. By having a thickness in this range, a good convex portion 50A can be formed on the laminated body 50.

As another embodiment (hereinafter referred to as the second embodiment) in the convex portion forming portion 5, as shown in FIGS. 6 and 7, a second convex portion forming member 520 is used in addition to the convex portion forming member 52. It is also possible to form two types of convex portions 50A and a second convex portion 520A on the laminated body 50 (hereinafter, in the second embodiment, the convex portion 50A is also referred to as a first convex portion 50A). In the second embodiment, as shown in FIG. 6, the second convex portion forming member 520 is arranged so as to overlap the upper portion of the above-mentioned convex portion forming member 52. The second convex portion forming member 520 is regularly formed with a large number of quadrangular opening portions 520a over the entire surface thereof. As shown in FIG. 8, the width La of the quadrangular opening portion 520a is larger than the width L of the opening portion 52a of the convex portion forming member 52. In this way, by using the two types of convex portion forming members 52 and 520 in an overlapping manner, the wiping sheet 10 (hereinafter, also referred to as the wiping sheet 10'in the second embodiment) can be placed on the first surface 50Y side. The first convex portion 50A can be formed so as to bulge from the top of the second convex portion 520A so as to be arranged in a large number and regularly.

According to the second embodiment in which the two types of convex portion forming members 52 and 520 are used in an overlapping manner, the first convex portion 50A and the first convex portion 50A are located on the first surface 50Y side of the wiping sheet 10'. It has a second convex portion 520A composed of a large macroscopic pattern (a rhombic grid pattern in the second embodiment), and the first convex portion 50A is located within the second convex portion 520A in two stages. A step is formed. In this case, at the top of the first convex portion 50A, the abundance ratio of the first fiber 20 at the top to the entire fibers constituting the first convex portion 50A is higher than the abundance ratio of the second fiber 40. Moreover, in the hem portion of the first convex portion 50A, the abundance ratio of the second fiber 40 in the hem portion with respect to the entire fibers constituting the first convex portion 50A is higher than the abundance ratio of the first fiber 20.

In the second embodiment in which the two types of convex portion forming members 52 and 520 are stacked and used, as shown in FIG. 7, the water flow sprayed from the second water flow nozzle 51 toward the surface 50X on the first fiber 20 side is used. The laminated body 50 is pressed against the surface 50Y on the side of the second fiber 40 so as to be in close contact with the second convex portion forming member 520. At this time, the first fiber 20 and the second fiber 40 enter the opening portion 520a, and a plurality of second convex portions 520A having a shape corresponding to the shape of the opening portion of the second convex portion forming member 520 It is formed regularly. Further, the water flow sprayed from the second water flow nozzle 51 presses the surface 50Y on the second fiber 40 side of the second convex portion 520A so as to be in close contact with the convex portion forming member 52, and the first convex portion 50A. Are formed so as to be arranged in large numbers and regularly on the top of the second convex portion 520A. In this way, a plurality of first convex portions 50A are formed by protruding from the top of one second convex portion 520A, so that the first convex portion 50A and the second convex portion 520A have a two-step height difference. Will be. Also in this step, the laminated body 50 in which a plurality of convex portions 50A are formed can be obtained as in the embodiment in which the convex portion forming member 52 is used alone.

The wiping sheet 10'of the second embodiment obtained by the above step is from the surface (second surface) 50X on the side of the first fiber 20 to the surface (first surface) 50Y side on the second fiber side. The first convex portion 50A and the second convex portion 520A are formed so as to project toward the direction. The first convex portion 50A and the second convex portion 520A have a shape that rises from the flat surface of the first surface 50Y. Further, as described above, the first convex portion 50A is located in the second convex portion 520A, and has a shape protruding from the top of the second convex portion 520A. By having these shapes, a convex portion having two steps of height difference is formed when viewed from the flat surface of the first surface 50Y. The entire surface of the second surface 50X may be a flat surface depending on the manufacturing method of the wiping sheet 10'in the second embodiment, and the region corresponding to the first convex portion 50A and the second convex portion 520A may be formed. It may be depressed.

As shown in FIG. 8, the width La of the opening portion 520a in the second convex portion forming member 520 is preferably 400 μm or more and 10 mm or less, and more preferably 420 μm or more and 8 mm or less. By having this width La, it is possible to form the second convex portion 520A having a good appearance and capable of reducing the resistance at the time of wiping in the laminated body 50.

As shown in FIG. 8, the thickness T of the second convex portion forming member 520 is preferably 600 μm or more and 4 mm or less, and more preferably 700 μm or more and 3 mm or less. By having a thickness in this range, it is possible to form the second convex portion 520A which has a good appearance in the laminated body 50 and can reduce the resistance at the time of wiping.

Returning to FIG. 2 again, finally, the laminated body 50 in which the convex portion 50A is formed by the convex portion forming portion 5 is conveyed downstream from the convex portion forming portion 5 by the transport belt 54, and the target dry type is used. A wiping sheet 10 (or a wiping sheet 10') can be obtained. Further, after the laminated body 50 in which the convex portion 50A is formed by the convex portion forming portion 5 is conveyed downstream from the convex portion forming portion 5 by the conveying belt 54, it further corresponds to the second surface of the wiping sheet 10. It is also possible to supply and support the wiping liquid from the surface side. By going through this step, the desired wet wiping sheet 10 (or wiping sheet 10') can be obtained.

When the wet wiping sheet 10 (or wiping sheet 10') is manufactured, the amount of the wiping liquid supported is 6 g when the dimensions of one wiping sheet are 285 mm × 205 mm as described in Examples described later. / Sheet or more is preferable, 8 g / sheet or more is more preferable, and 10 g / sheet or more is further preferable. The upper limit of the content of the wiping liquid is preferably 40 g / sheet or less, more preferably 30 g / sheet or less, and further preferably 20 g / sheet or less. As a method of supporting the wiping liquid, a method such as spraying, coating, or dipping can be adopted.

The wiping sheet 10 (or wiping sheet 10') manufactured in this manner is attached to the wiping sheet alone or a cleaning tool such as a wiper, and is attached to a building such as a floor surface or a wall surface, a cupboard, a window glass, or a mirror. , Doors, doorknobs and other fittings, rugs, carpets, desks and dining tables and other furniture, kitchens, toilets, body cleaning, sanitary goods, packaging, etc.

Although the present invention has been described above based on the preferred embodiment, the present invention is not limited to the above embodiment. For example, in FIG. 2, the number and water pressure of the first and second water flow nozzles 31, 51 may be the same or different.

Further, the wiping sheet 10 (or wiping sheet 10') of the above-described embodiment contains two types of fibers, the first and second fibers, but instead of the wiping sheet 10 (or the wiping sheet 10'), a wiping sheet containing three or more types of fibers. It may be.

Regarding the above-described embodiment, the present invention further discloses the following wiping sheet and a method for producing the same.
<1>
A first surface which contains at least a first fiber and a second fiber having a diameter smaller than that of the first fiber, includes a fiber aggregate formed by entwining these fibers, and is used as a wiping surface, and the first surface thereof. A wiping sheet having a second surface located on the opposite side of the surface.
The abundance ratio of the second fiber is higher in the first surface than in the second surface.
A plurality of convex portions are formed on the first surface side.
The abundance ratio of the first fiber at the top to the entire fibers constituting the convex portion is higher than the abundance ratio of the second fiber.
A wiping sheet in which the abundance ratio of the second fiber in the hem portion with respect to the entire fiber constituting the convex portion is higher than the abundance ratio of the first fiber.

<2>
The wiping sheet according to <1>, wherein the first fiber and the second fiber are entangled with each other without heat fusion.
<3>
The area ratio occupied by the second fiber in the first surface is preferably 40% or more and 99% or less, more preferably 45% or more and 95% or less, further preferably 50% or more and 90% or less, and the second surface in the second surface. The wiping sheet according to <1> or <2>, wherein the area ratio occupied by the fibers of 2 is preferably 0% or more and 55% or less.
<4>
The wiping sheet according to any one of <1> to <3>, wherein a plurality of the convex portions are regularly arranged.
<5>
Any of the above <1> to <4>, wherein the region corresponding to the convex portion on the second surface side is recessed from the flat surface on the second surface toward the first surface to form a concave portion. The wiping sheet described in item 1.
<6>
The wiping sheet according to any one of <1> to <4>, wherein the entire second surface is a flat surface.

<7>
The wiping sheet according to any one of <1> to <6>, wherein the convex portion is a solid one whose inside is filled with fibers.
<8>
The wiping sheet according to any one of <1> to <6>, wherein the convex portion is a solid one whose inside is filled with a first fiber and / or a second fiber.
<9>
The wiping sheet according to any one of <1> to <8>, wherein the convex portions are regularly arranged on the first surface side of the wiping sheet.
<10>
The wiping sheet according to any one of <1> to <9>, wherein the convex portions are regularly arranged along the longitudinal direction and / or the width direction of the wiping sheet.
<11>
The wiping sheet according to any one of <1> to <10>, wherein the convex portion has a width of 400 μm or more and 10 mm or less and a height of 110 μm or more and 25 mm or less.

<12>
The width of the convex portion is more preferably 800 μm or more, further preferably 900 μm or more, further preferably the width W of 8 mm or less, further preferably 5 mm or less, the above <1>. The wiping sheet according to any one of <11>.
<13>
The first surface side has the convex portion and the second convex portion having a macroscopic pattern larger than the convex portion, and the convex portion is located in the second convex portion and has a two-step step. Is formed,
At the top of the convex portion, the abundance ratio of the first fiber in the apex to the entire fibers constituting the convex portion is higher than the abundance ratio of the second fiber, and at the hem of the convex portion, The item according to any one of <1> to <12>, wherein the abundance ratio of the second fiber in the hem portion with respect to the entire fiber constituting the convex portion is higher than the abundance ratio of the first fiber. Wiping sheet.
<14>
The wiping sheet according to <13>, wherein the convex portion is formed on the top of a second convex portion larger than the convex portion.
<15>
The wiping sheet according to <13>, wherein a plurality of the convex portions are formed on the top of the second convex portion.

<16>
The frictional force between the wiping target surface and the wiping sheet is preferably 5 N or less when wiping by applying a pressure of 55 N ^{/ m 2} to a wiping sheet having a size of 10 cm × 25 cm. The wiping sheet according to any one of <1> to <15>, wherein the wiping sheet is more preferably 4N or less.
<17>
The abundance ratio of the first fiber and the second fiber at the top of the convex portion is such that the second fiber is three times or more as much as the first fiber on the basis of the number of fibers constituting the convex portion. The wiping sheet according to any one of <1> to <16>.
<18>
The abundance ratio of the first fiber and the second fiber in the hem of the convex portion is more than twice that of the first fiber in the second fiber on the basis of the number of fibers constituting the convex portion. , The wiping sheet according to any one of <1> to <17>.
<19>
The first fiber and the second fiber are fibers made from polyester, polyamide, polyolefin, cellulose fiber, various metals, glass, and minerals, and polyester, polyamide, polyolefin, and cellulose fiber are preferable. The wiping sheet according to any one of <18>.
<20>
The wiping sheet according to any one of <1> to <19>, wherein the first fiber and the second fiber are preferably fibers having the same composition.

<21>
The iping sheet according to any one of <1> to <20>, wherein the diameter of the first fiber is preferably 10 μm or more and 30 μm or less, and more preferably 15 μm or more and 25 μm or less.
<22>
The wiping sheet according to any one of <1> to <21>, wherein the diameter of the second fiber is preferably 0.1 μm or more and 9 μm or less, and more preferably 0.5 μm or more and 5 μm or less.
<23>
The wiping sheet according to any one of <1> to <22>, wherein the wiping liquid is at least supported on a fiber assembly located on the second surface side.
<24>
The wiping sheet according to <23>, which has a release layer of the wiping liquid and a liquid retention layer supporting the wiping liquid, and the release layer includes a first surface.

<25>
The method for manufacturing a wiping sheet according to any one of <1> to <24>.
A laminate of a fiber aggregate of the first fiber and a fiber aggregate of a second fiber having a diameter smaller than that of the first fiber, and a convex portion in which the fiber aggregate of the second fiber has a plurality of openings. Under the state of being arranged so as to face the forming member, a water stream is sprayed from the side of the fiber aggregate of the first fiber to entangle the first fiber and the second fiber, and the position is located at the opening. A method for producing a wiping sheet in which the fiber aggregate is projected into the opening.
<26>
The method for producing a wiping sheet according to <25>, wherein the fiber aggregate of the second fiber is formed by a melt-type electrostatic spinning method.

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

[Example 1]
The wiping sheet 10 having the structure shown in FIG. 1 was manufactured by using the manufacturing apparatus 1 shown in FIGS. 2 to 5 and the convex portion forming member 52. As the first fiber 20, a mixed cotton body having an average diameter of 11.4 μm containing PET: acrylic: rayon = 7: 1.5: 1.5 in a mass ratio was used. As the second fiber 40, polypropylene having an average diameter of 1 μm obtained by an electrospinning method was used. The basis weight of the first fiber 20 was 60 g / m ^2, and the basis weight of the second fiber 40 was 5 g / m ² . The wiping sheet 10 was rectangular, had dimensions of 285 mm × 205 mm, and had a thickness T of 1.6 mm. The height H of the convex portion 50A on the first surface 50Y side of the wiping sheet 10 was 0.7 mm, and the width W was 2 mm. On average, 34 convex portions 50A were arranged in a virtual circle having a diameter of 20 mm. The area ratio of the second fiber 40 on the first surface 50Y was 90%, and the area ratio of the second fiber 40 on the second surface 50X was 5%. The abundance ratio of the first fiber 20 in the top 50T with respect to the entire fibers constituting the convex portion 50A is twice that of the second fiber 40 on an area basis (67% as an area ratio), and constitutes the convex portion 50A. The abundance ratio of the second fiber 40 in the hem 50B with respect to the entire fiber was 1.1 times the area standard (52% as the area ratio) with respect to the first fiber 20.
The wiping sheet 10 of Example 1 was made into a wet wiping sheet by supporting a wiping liquid. The wiping liquid was at least supported on the fiber assembly located on the second surface side. The amount of the wiping liquid supported was 20 g / sheet. As the wiping liquid, a 0.01% by mass aqueous solution of a surfactant (Emargen 108, manufactured by Kao Corporation) was used.

[Example 2]
A wiping sheet was produced in the same manner as in Example 1 except that the wiping liquid was not supported on the wiping sheet of Example 1. That is, the wiping sheet of Example 2 is a dry type.

[Comparative Example 1]
As the wet wiping sheet, a wet sheet for floors of Scotch-Brite (registered trademark) manufactured by 3M Co., Ltd. was used. This wet wiping sheet is composed of a fiber aggregate of small-diameter fibers and large-diameter fibers, but the convex portion of the present invention is not formed on the wiping surface.

[Comparative Example 2]
As a dry wiping sheet, a wet sheet for floors of Scotch-Brite (registered trademark) manufactured by 3M Co., Ltd. was used after being dried for 24 hours in an environment of a temperature of 20 ° C. and a relative humidity of 65%. This wiping sheet is composed of a fiber aggregate of small-diameter fibers and large-diameter fibers, but the convex portion of the present invention is not formed on the wiping surface.

[Comparative Example 3]
As a dry wiping sheet, a super fine adsorption dry sheet manufactured by Yamazaki Sangyo Co., Ltd. was used. This wiping sheet is composed of a fiber aggregate of small-diameter fibers and large-diameter fibers, but the convex portion of the present invention is not formed on the wiping surface.

〔evaluation〕
^{A pressure of 55 N / m 2} was applied to the wiping sheets of each of the Examples and Comparative Examples to wipe an area ^{of 1.8 m 2} with a flooring (Combit New Advance 101, manufactured by Wood One Co., Ltd.) as a wiping target surface. The resistance at the time was measured by the above method. The results are shown in FIGS. 9 and 10.

As a result of comparing the resistance strengths of Example 1 and Comparative Example 1 which are wet wiping sheets, the resistance strength of Example 1 was 2.7N as shown in FIG. On the other hand, the resistance of Comparative Example 1 was 15.7N. From these results, it can be seen that the wet wiping sheet 10 in Example 1 has low frictional resistance during wiping and high operability.

As a result of comparing the resistances of Example 2 and Comparative Examples 2 and 3 which are dry wiping sheets, the resistance of Example 2 was 1.8N as shown in FIG. On the other hand, the resistance force of Comparative Example 2 was 2.2N, and the resistance force of Comparative Example 3 was 4.1N. From these results, it can be seen that the dry wiping sheet 10 in Example 2 has low frictional resistance during wiping and high operability, like the wet wiping sheet 10 in Example 1.

In particular, as is clear from the comparison between Example 1 and Comparative Example 1 and Example 2 and Comparative Example 2, it can be seen that the frictional resistance is significantly reduced when the wiping sheet of the present invention is used wet. ..

1 Wiping sheet manufacturing equipment 2 Web forming part 3 Entanglement part 4 Electrostatic spinning part 5 Convex part forming part 10 Wiping sheet 20 First fiber 40 Second fiber 50A Confounding part 50Y First surface 50X Second surface

Claims (8)

A first surface which contains at least a first fiber and a second fiber having a diameter smaller than that of the first fiber, includes a fiber aggregate formed by entwining these fibers, and is used as a wiping surface, and the first surface thereof. A wiping sheet having a second surface located on the opposite side of the surface.
The abundance ratio of the second fiber is higher in the first surface than in the second surface.
A plurality of convex portions are formed on the first surface side.
The abundance ratio of the first fiber at the top to the entire fibers constituting the convex portion is higher than the abundance ratio of the second fiber.
A wiping sheet in which the abundance ratio of the second fiber in the hem portion with respect to the entire fiber constituting the convex portion is higher than the abundance ratio of the first fiber. The wiping sheet according to claim 1, wherein the plurality of the convex portions are regularly arranged. The wiping sheet according to claim 1 or 2, wherein the convex portion has a width of 400 μm or more and 10 mm or less and a height of 110 μm or more and 25 mm or less. The first surface side has the convex portion and the second convex portion having a macroscopic pattern larger than the convex portion, and the convex portion is located in the second convex portion and has a two-step step. Is formed,
At the top of the convex portion, the abundance ratio of the first fiber in the apex to the entire fibers constituting the convex portion is higher than the abundance ratio of the second fiber, and at the hem of the convex portion, The wiping sheet according to any one of claims 1 to 3, wherein the abundance ratio of the second fiber in the hem portion with respect to the entire fiber constituting the convex portion is higher than the abundance ratio of the first fiber. .. The wiping sheet according to any one of claims 1 to 4, wherein the wiping liquid is at least supported on a fiber assembly located on the second surface side. The wiping sheet according to claim 5, further comprising a release layer of the wiping liquid and a liquid retention layer supporting the wiping liquid, and the release layer includes a first surface. The method for manufacturing a wiping sheet according to any one of claims 1 to 6.
A laminate of a fiber aggregate of the first fiber and a fiber aggregate of a second fiber having a diameter smaller than that of the first fiber, and a convex portion in which the fiber aggregate of the second fiber has a plurality of openings. Under the state of being arranged so as to face the forming member, a water stream is sprayed from the side of the fiber aggregate of the first fiber to entangle the first fiber and the second fiber, and the position is located at the opening. A method for producing a wiping sheet in which the fiber aggregate is projected into the opening. The method for producing a wiping sheet according to claim 7, wherein the fiber aggregate of the second fiber is formed by a melt-type electrostatic spinning method.

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