JP2019030572A - Wiping sheet and its manufacturing method - Google Patents

Abstract

To provide a wiping sheet in which friction resistivity between a wiping object and itself is reduced, and operability in the wiping is increased.SOLUTION: A wiping sheet 10 includes a fiber assembly formed by entangling first fibers 20 and second fibers 40 with diameter smaller than that. The wiping sheet has a first surface 50Y as a wiping surface and a second surface 50X positioned in the opposite side. An abundance ratio of the second fibers 40 is increased in the first surface more than the second surface. Multiple protrusions 50A are formed in the first surface 50Y side, and the abundance ratio of the first fiber 20 in the top 50T to the whole fibers for constituting the protrusions 50A becomes higher than the abundance ratio of the second fiber 40 in the top 50T of the protrusions 50A. The abundance ratio of the second fibers 40 in hems 50B to the whole fibers for constituting the protrusions 50A becomes higher than the abundance ratio of the first fiber 20 in the hems 50B of the protrusions 50A.SELECTED DRAWING: Figure 1

Description

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

  Various attempts have been made to improve the function and the like of the nonwoven fabric by forming an uneven structure on the surface of the nonwoven fabric. For example, Patent Document 1 describes a non-woven fabric that is configured by integration of at least one of nanofibers and microfibers by electrospinning and has an uneven micropattern at a predetermined position on a plane. Yes. According to this non-woven fabric, the functional enhancement is achieved by the shape specificity due to the uneven micro-pattern structure, the cell affinity and the material structure are improved, and the biofunctionality 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 nonwoven fabric includes a fiber bundle in which a plurality of fibers are intertwined with each other and a depression in the vicinity thereof. The number of ultrafine fibers in the fiber bundle is greater than the number of ultrafine fibers in the depression. This literature describes that the nonwoven fabric is excellent in bulkiness and is flexible and has a soft touch when touched on the target surface.

JP 2006-328562 A JP 2009-13544 A

  By the way, a wiping sheet made of a nonwoven fabric is often used as an article for wiping hard surfaces such as flooring and furniture. Although the technique regarding a nonwoven fabric is described in the patent document 1 mentioned above, the nonwoven fabric described in the literature is intended for application to medical devices such as regenerative medicine, and is intended for cleaning and cleaning purposes. No mention is made of the functionality of the nonwoven fabric.

  When the nonwoven fabric having the concavo-convex structure described in Patent Document 2 is used as a cleaning article, the frictional resistance between the nonwoven fabric and the object to be cleaned increases due to the nonwoven fabric containing fine fibers. Therefore, the operability of the nonwoven fabric during cleaning may be inferior.

  Therefore, the subject of this invention is providing the wiping sheet which made small the friction resistance between wiping objects, and improved the operativity at the time of wiping.

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

The present invention also provides a method for producing the wiping sheet as described above.
A laminate of a fiber aggregate of a first fiber and a fiber aggregate of a second fiber having a smaller diameter than the first fiber, and a convex part in which the fiber aggregate of the second fiber has a plurality of apertures Under the state of being arranged so as to face the forming member, a water stream is blown from the fiber assembly side of the first fiber to entangle the first fiber and the second fiber, and at the opening portion. A method of manufacturing a wiping sheet for causing the fiber assembly to protrude into the aperture is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the wiping sheet which reduced the frictional resistance at the time of wiping, and improved the operativity at the time of wiping, and its manufacturing method are provided.

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 a convex forming member used in the present invention. FIG. 4 is an enlarged view of a main part showing a process for manufacturing the wiping sheet of the present invention. 5 is a cross-sectional view taken along 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 (corresponding to FIG. 4) showing a main part of another process for producing the wiping sheet of the present invention. 8 is a cross-sectional view taken along 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 value of the dry wiping sheet in Example 2 and Comparative Examples 2 and 3.

  Hereinafter, the wiping sheet of the present invention will be described based on preferred embodiments thereof. In the present invention, wiping includes the meanings of both cleaning and wiping. For example, cleaning of buildings such as floors, walls, ceilings, and pillars, cleaning of fittings and fixtures, wiping of articles, the body and the body Including cleaning of appliances related to

  The wiping sheet of the present invention comprises a fiber assembly. The fibers constituting the fiber assembly include at least a first fiber and a second fiber having a smaller diameter than the first fiber. The first fiber and the second fiber are the first fiber, the second fiber, and the first fiber and the second fiber entangled to form the fiber assembly. The fiber assembly may carry a wiping liquid. The wiping liquid and its loading method will be described in detail later. In the present specification, the term “wiping sheet” simply refers to a sheet carrying a wiping liquid and a sheet carrying no wiping liquid depending on the context.

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

  FIG. 1 shows an enlarged main part of a longitudinal section of an embodiment of the wiping sheet of the present invention. As shown in the figure, the wiping sheet 10 includes a first fiber 20 and a 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 used as a wiping surface when the wiping sheet 10 is used. As shown in FIG. 1, there is a fiber assembly of second fibers 40, which are fibers having a thin fiber diameter, on the upper side of the figure, which is a wiping surface. Therefore, the lower side of the figure is the opposite side of the wiping surface and the back side.

  The wiping sheet 10 protrudes from the second surface 50X toward the first surface 50Y, thereby forming a convex portion 50A. A plurality of convex portions 50 </ b> A are formed across 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, a region corresponding to the convex portion 50A is recessed from the flat surface 50X ′ of the second surface 50X toward the first surface 50Y to form a concave portion 50C. Depending on the manufacturing method of the wiping sheet 10, the entire area of the second surface 50 </ b> X may be a flat surface. In the present specification, the description regarding the first surface 50Y (wiping surface) does not include the convex portion 50A.

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

  Each convex part 50A can be regularly arranged on the first surface 50Y side of the wiping sheet 10, or can be irregularly arranged. When the convex portions 50A are regularly arranged on the first surface 50Y, for example, they can be regularly arranged along the longitudinal direction of the wiping sheet 10 and / or along the width direction. Even if each convex part 50A is arrange | positioned regularly and irregularly, it is a wiping sheet | seat by forming several convex part 50A in the 1st surface 50Y side which is a wiping surface. When performing the wiping operation using 10, 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, the wiping sheet 10 is unevenly distributed in locations where the first fibers 20 and the second fibers 40 are present in a longitudinal sectional view. Specifically, in the wiping sheet 10, the presence ratio of the second fibers 40 is higher on the first surface 50Y that is the wiping surface than on the second surface 50X that is the surface opposite to the wiping surface. . By adopting this configuration, the wiping effect by the wiping sheet 10 can be enhanced in combination with the formation of a plurality of convex portions 50A on the first surface 50Y side.

  As described above, in the wiping sheet 10, the presence ratio of the second fibers 40 is higher on the wiping surface than on the surface opposite to the wiping surface. At the same time, when paying attention to the first surface 50Y that is the wiping surface, the convex portion 50A formed on the first surface 50Y side has the top portion 50T at the top portion 50T with respect to the entire fibers constituting the convex portion 50A. The existence ratio of one fiber 20 is higher than the existence ratio of the second fiber 40. On the other hand, in the skirt part 50B of the convex part 50A, the existence ratio of the second fibers 40 in the skirt part 50B with respect to the entire fibers constituting the convex part 50A is higher than the existence ratio of the first fibers 20. Surprisingly, the friction ratio between the surface to be wiped and the wiping sheet 10 can be effectively increased by the existence ratio of the first and second fibers 20 and 40 constituting the convex portion 50A. It has been found that it can be reduced.

The frictional force between the wiping target surface and the wiping sheet 10 is preferably 10N 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. More preferably, it is more preferably 4N or less. There is no particular limitation on the lower limit value of the resistance force, and the lower the better, the better. However, if the resistance force is as low as about 0.8 N, the wiping operation can be performed smoothly.

  Specifically, the measurement of the resistance force when wiping is performed by the following method. Head part of quick pull wiper (manufactured by Kao Corporation) with a crocodile-type clip attached to the tip of a push-pull gauge (RX-20, manufactured by Aiko Engineering Co., Ltd.) and a 285 mm x 205 mm wiping sheet attached to the clip Install. The maximum load recorded on the push-pull gauge when this head part is scanned for 1 m at a speed of 1 cm / sec on a flooring (Combit New Advance 101, manufactured by Wood One) 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 skirt portion 50B of the convex portion 50A is a region from the flat surface 50Y 'to (1/3) H in the first surface 50Y.

  From the viewpoint of more effectively reducing the frictional force between the wiping target surface and the wiping sheet 10, the ratio of the first fibers 20 and the second fibers 40 in the top 50T of the convex portion 50A is the same as that of the convex portion 50A. It is preferable that the first fiber is three times or more the second fiber on the basis of the number of fibers constituting the first fiber. From the same point of view, the existence ratio of the first fiber 20 and the second fiber 40 in the skirt 50B of the convex portion 50A is such that the second fiber is the second fiber on the basis of the number of the 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 depend on the shape of the convex portion 50A. From the viewpoint of more effectively reducing the frictional force, the convex portion 50A preferably has a width W of 400 μm or more, more preferably 800 μm or more, and even more preferably 900 μm or more. The width W is preferably 10 mm or less, more preferably 8 mm or less, and even more preferably 5 mm or less. The width W is preferably 400 μm to 10 mm, more preferably 800 μm to 8 mm, and still more preferably 900 μm to 5 mm. 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 ′ of 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 even more preferably 900 μm or more. The height H is preferably 25 mm or less, more preferably 20 mm or less, and even more 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 even more preferably 900 μm or more and 18 mm or less. As shown in FIG. 1, the height H is a 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 portions 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 preferably 15 or more, and 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 still more preferably 20 or more and 40 or less.

  The wiping sheet 10 of the present invention may be a dry type that does not carry a wiping liquid (hereinafter, this mode is also referred to as a “dry wiping sheet”), or a wet type wiping liquid. (Hereinafter, this embodiment is also referred to as “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 supported at least on the fiber assembly located on the second surface side. Note that, at least the wiping liquid is carried on the fiber assembly whose wiping surface is located on the second surface side is a mode in which the fiber assembly on the opposite side of the wiping surface contains the wiping liquid, and the fiber assembly on the wiping surface side The body also includes a mode in which a wiping liquid is contained in the gap. Preferably, the amount of the wiping liquid carried is larger than the amount carried on the fiber assembly opposite to the wiping surface.

  In particular, when the wiping sheet 10 of the present invention is a wet wiping sheet, the first fibers 20 in the top portion 50T and the bottom portion 50B of the convex portion 50A in addition to the plurality of the convex portions 50A described above. And the presence ratio of the second fibers 40, the width W and height H of the convex portions 50A on the first surface 50Y side, and / or the formation density of the convex portions 50A satisfy a specific range, This is advantageous in that the effect of reducing the frictional resistance becomes more remarkable.

  From the viewpoint of further increasing the wiping effect by the wiping sheet 10 in combination with the formation of the plurality of convex portions 50A, and from the viewpoint of being able to stably carry a large amount of wiping liquid when the wet wiping sheet 10 is used. Of the surface of the wiping sheet 10 including voids, the area ratio of the second fibers in 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 of the second fibers 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 obtained, 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 determined in the same manner as described above. Therefore, the area ratio is a value obtained by dividing the area occupied by the fiber by the area to be measured. In the case of% display, the value is 100 times the divided value.

  Here, for example, the remaining 1% of the upper limit of 99% in the area ratio of 40% to 99% is a void. This gap is necessary because the wiping liquid is 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 a necessary amount even when wiping strongly, especially when the wet wiping sheet 10 is used. it can. In addition, by setting the area ratio of the second fibers on the surface opposite to the wiping surface as described above, as a result, voids increase and the amount of wiping liquid carried on the wet wiping sheet 10 increases. If the area ratio occupied by the second fibers on the wiping surface is too small, the wiping liquid is discharged more than necessary. Therefore, the area that can be wiped is narrowed.

  In the wiping sheet 10, the area ratio occupied by the second fibers 40 in a plane parallel to the wiping surface decreases stepwise, in a curve, or a combination thereof in the thickness direction on the opposite side of the wiping surface. It is preferable. 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 and the area ratio occupied by the second fibers 40 are in the range of 50% or more and 100% or less. When the wiping sheet 10 is used, the carrying amount of the wiping liquid can be increased. Here, the ratio of the thickness in which the area ratio occupied by the second fibers 40 is in the range of 50% to 100% is preferably 1% to 90%, more preferably 5% to 70%, More preferably, it is 7% or more and 50% or less. In addition, by setting it as the ratio of preferable thickness as mentioned above, when it is set as the wet wiping sheet | seat 10, the required amount of wiping liquid discharge | released in order to wipe off the stain | pollution | contamination of the surface to be wiped can be discharge | released. The thickness of the wiping sheet 10 is a distance T from the surface opposite to the wiping surface to the apex of the convex portion 50A as shown in FIG.

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

  The wet wiping sheet 10 includes at least two layers of a liquid retaining layer that carries a wiping liquid and a wiping liquid discharge layer, and the discharge layer includes a wiping surface. In particular, in order to carry a large amount of wiping liquid, as described above, the area ratio that the second fiber occupies from 50% to 100% of the thickness of the wiping sheet 10 from the surface opposite to the wiping surface. Is 1% to 100%. As a result, a liquid retaining layer that carries most of the wiping liquid can be obtained. On the other hand, the release layer is a portion other than the liquid retaining layer including the wiping surface.

  In the wiping sheet 10, the capillary pressure on the wiping surface side is preferably higher than that on the opposite side of the wiping surface. Thereby, especially when using as the wet wiping sheet | seat 10, even if it wipes strongly at the time of wiping, the quantity of the wiping liquid discharge | released in order to wipe off the stain | pollution | contamination of a wiping object surface can be controlled to required amount. Therefore, even in the case of wiping with a large wiping area such as rugs, carpets, and floors, it is not necessary to change to a new wiping sheet 10 during wiping, or the number of times of replacement can be reduced.

Here, it is known that the capillary pressure follows the following relationship.
Pc = 2kγ _L / r × cos θ
Where Pc is the capillary pressure (N / m ² ) of the fiber assembly, γ _L is the surface tension (N / m) of the liquid, θ is the contact angle (rad) between the fiber and the liquid, r is the fiber diameter (m), and k is a correction coefficient.

  Pc derived from the above equation is a value using the summary statistic derived from the measurement of the fiber assembly. 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 a plate method such as DY-200 manufactured by Kyowa Interface Science Co., Ltd. H. It is set as the average value measured 10 times in the environment. The fiber diameter was measured with 30 scanning magnifications at an observation magnification of 350 times from observation with a scanning electron microscope, and this was taken as an average value obtained by randomly measuring 150 fiber diameters at a total of 5 locations. The contact angle between the fiber and the liquid is determined by identifying the constituent fibers of the fiber assembly by Fourier transform infrared spectroscopy (FTIR) and measuring the contact angle on a resin plate having the same composition. Specifically, the contact angle when 3 seconds have elapsed 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 five locations on the plate, and the average value is obtained. . In addition, when there are a plurality of fiber materials, the contact angle is measured in the same manner for each material, and the value at the time of Pc calculation is a weighted average of the contact angles based on the surface area ratio of each fiber component. Of θ. The correction coefficient is measured by measuring the water absorption of Klem as defined 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 section constituting the nonwoven 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 equation, the capillary pressure increases as the fiber diameter is reduced. 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 examples of the fiber include polyester, polyamide, polyolefin, cellulose fiber, and fibers made from various metals, glass, and minerals. Among these, polyester, polyamide, polyolefin, and cellulose fiber are preferable.

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

  The polyolefin is obtained from a monomer having an ethylenically unsaturated group. 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 and nylon 12, 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 dicarboxylic acid component is mentioned.

Examples of the diamine component include tetramethylenediamine, pentamethylenediamine, 2-methylpentanediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, dodecamethylenediamine, 2,2,4-trimethyl. -Aliphatic diamine compounds such as hexamethylenediamine and 2,4,4-trimethylhexamethylenediamine. 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, bis (4-aminocyclohexyl) methane, 2,2 Examples include alicyclic diamine compounds such as -bis (4-aminocyclohexyl) propane, bis (aminomethyl) decalin, and bis (aminomethyl) tricyclodecane. Furthermore, diamine compounds having an aromatic ring such as metaxylylenediamine, paraxylylenediamine, bis (4-aminophenyl) ether, paraphenylenediamine, bis (aminomethyl) naphthalene, and the like can be given.

  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. Moreover, phthalic acid compounds, such as isophthalic acid, terephthalic acid, ortho phthalic acid, are mentioned. Furthermore, 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 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.

  Cellulose fibers may be natural fibers or synthetic fibers, and examples of synthetic fibers include acylate fibers such as cellulose acetate.

  Moreover, these mixed fibers, for example, polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate, etc. are also mentioned.

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

  The fiber length of the fiber, that is, the average fiber length of the whole fiber used in the present invention depends on the fiber production method, but is generally preferably 1 mm to 100 mm, more preferably 10 mm to 90 mm, and still more preferably 20 mm to 60 mm. .

  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 to 9 μm, and more preferably 0.5 μm to 5 μm.

  The fibers having different fiber diameters may be the same component fibers or different component fibers, but in the present invention, the same component fibers are preferable. Also, the fiber lengths may be the same or different, but in the present invention, fibers having the same fiber length are preferred.

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 more preferably 10 g / m ² or more and 30 g / m ² on the wiping surface side. ² or less is more preferable. On the other hand, the surface opposite to the wiping surface is preferably 10 g / m ² or more and 50 g / m ² or less, more preferably 15 g / m ² or more and 30 g / m ² or less, and further more preferably 20 g / m ² or more and 25 g / m ² or less. preferable.

  In relation to the basis weight of the fibers constituting the wiping sheet 10, the thickness T of the wiping sheet 10 is preferably 1 mm or more under a load of 40 Pa, more preferably 1.2 mm or more, and 1.5 mm or more. More preferably it is. Moreover, it is preferable that it is 5 mm or less under the same load, it is still more preferable that it is 4 mm or less, and it is still more preferable that it is 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 operability during wiping is improved.

  In the present invention, it is particularly preferable that fibers having different fiber diameters are entangled without being thermally fused to each other. By doing in this way, the space | gap between fibers increases compared with the case where it heat-seal | fuses. As a result, when the wiping liquid is carried on the wiping sheet 10, the amount of the wiping liquid carried increases.

The wet wiping sheet 10 is preferably wiped once, that is, by wiping the surface to be wiped once, so that the amount of wiping liquid released from the surface to the surface to be wiped is preferably 0.5 g / tatami or more. 0.7 g / tatami mat or more is more preferable, and 1.0 g / tatami mat or more is more preferable. The upper limit of the amount released is realistically 8 g / tatami or less, preferably 7 g / tatami or less, more preferably 6 g / tatami or less. If the discharge amount is too small, wiping cannot be performed sufficiently. If the discharge amount is too large, the remaining wiping liquid tends to be generated on the wiping surface. Here, the tatami is 1820 mm × 910 mm and the area is 1.6552 m ² .

The measurement conditions of 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 carried, the discharge amount per tatami when measured under such measurement conditions is in the above range.

  The maximum liquid carrying amount that the wiping liquid can carry on the wiping sheet 10, that is, the initial liquid carrying amount is 1 g when the size of one wiping sheet 10 is 285 mm × 205 mm as described in Examples described later. / G or more is preferable, 10 g / sheet or more is more preferable, and 12 g / sheet or more is still more preferable. The upper limit of the initial liquid carrying amount is realistically 40 g / sheet or less, preferably 30 g / sheet or less, and more preferably 20 g / sheet or less.

  By doing in this way, the amount of liquid discharge | release more than 1 g / tatami per target wiping becomes possible, and it becomes possible to continue more than 6 tatami mats.

  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 liquid may contain an additive. Examples of additives include polymers of acrylic acid, methacrylic acid or maleic acid, or salts thereof, and copolymers of maleic acid and other vinyl monomers or salts thereof for the purpose of enhancing the rinsing effect. Is mentioned. Moreover, water-soluble organic solvents, such as a disinfectant, a fragrance | flavor, a fragrance | flavor, a deodorizer, an abrasive particle, a pH adjuster, alcohol, etc. are mentioned.

  The content of the surfactant and the additive as described above is generally within a range used in a wet wiping sheet.

  Next, a preferred method for manufacturing the wiping sheet 10 shown in FIG. 1 will be described with reference to FIGS. FIG. 2 shows a manufacturing apparatus 1 that is preferably used for manufacturing the wiping sheet 10. The manufacturing apparatus 1 includes a web forming part 2, an entanglement part 3, an electrostatic spinning part 4, and a convex part forming part 5.

  The web forming unit 2 forms a web of the first fibers 20. The web forming unit 2 includes a card machine 21 that forms a web from the first fibers 20 that are raw materials of the wiping sheet 10.

  The entanglement part 3 makes the web of the 1st fiber 20 entangle with a water flow. The entangled portion 3 includes a first water flow nozzle 31 that blows a water flow onto the web of the first fibers 20 and a first support belt 32 that is an endless belt. The first water nozzle 31 is located above the web of the first fibers 20 and the first support belt 32 and can spray a high-pressure water stream over the entire width direction of the web of the first fibers 20. ing. The first support belt 32 is arranged to face the first water flow nozzle 31 and has a structure in which holes are formed in a lattice pattern or the like in order to transmit the sprayed water (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 unit 4 by the first support belt 32.

  The electrostatic spinning unit 4 generates second fibers 40 made of nanofibers by an electrostatic spinning method, and deposits them on one surface of the entangled body of the first fibers 20 entangled by the water flow nozzle 31 of the entanglement unit 3. It is. The electrostatic spinning unit 4 includes an ejection unit 41 that ejects the raw material liquid of the second fiber 40 and electrostatically spins, and a collection electrode 42 that collects the ejected raw material liquid as the second fiber 40. ing. The injection part 41 is comprised from the supply part of the raw material liquid of the 2nd fiber 40, an electrode, a voltage application part, etc. (not shown). A positive voltage or a negative voltage is applied to the injection unit 41. The collection electrode 42 is disposed so as to face the injection unit 41. The collecting electrode 42 is made of a conductive member and is grounded.

  When a voltage is applied to the ejection unit 41, the raw material liquid of the second fiber 40 is charged by electrostatic induction until it is ejected from the ejection unit 41, and is ejected in a charged state. The raw material liquid jetted in a charged state causes a self-repulsion of the raw material liquid due to the action of an electric field, and the second fibers 40 are generated as nano-sized thin fibers (nanofibers). The generated second fibers 40 are randomly deposited on one surface of the entangled body of the first fibers 20 traveling in the vicinity of the collecting electrode 42 to form a fiber assembly. By this electrostatic spinning process, a laminated body 50 of fiber assemblies composed of the first fibers 20 and the second fibers 40 is formed. The obtained laminated body 50 is conveyed to the convex part forming part 5.

  As the raw material liquid for 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 solution in which a polymer compound is dissolved or dispersed in a solvent can also be referred to as a solution type electrospinning method, and a method using a melt obtained by melting a polymer compound can also be referred to as a melt type electrospinning method. . Any electrostatic spinning method can be used in the present invention.

  In the convex part formation part 5, while spraying a water flow on the laminated body 50 of the fiber assembly of the 1st fiber 20 and the fiber assembly of the 2nd fiber 40, while entangling a 1st fiber and a 2nd fiber, Protrusions are formed. The convex portion forming part 5 includes a second water flow nozzle 51 that blows a water flow onto the laminate 50 from the first fiber 20 side, a convex portion forming member 52 that forms a convex portion on the second fiber 40 side by the water flow, The second support belt 53 is provided below the convex portion forming member 52, and the conveyance belt 54 is configured to convey 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 a water flow over the entire width direction of the laminated body 50. The convex forming member 52 is located below the laminated body 50 and is disposed so as to face the fiber assembly of the second fibers. As shown in FIG. 3, the convex portion forming member 52 is regularly formed with a plurality of circular aperture portions 52 a over the entire region. The protrusion forming member 52 is not particularly limited as long as it has an opening, and a punching metal, a plastic net, or the like can be used. Moreover, there is no restriction | limiting in particular also about the shape of the opening part 52a, In addition to the circle | round | yen shown in FIG. 3, polygonal shapes, such as an ellipse, a triangle, a square, and a pentagon, may be sufficient. The convex 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 first fiber 20 side surface 50 </ b> X forms a convex surface on the second fiber 40 side surface 50 </ b> Y of the laminate 50. It presses so that it may contact | adhere to the upper surface of the member 52. FIG. At the same time, the fiber aggregates of the first fibers 20 and the second fibers 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 further separated, and in the top part 50T of the convex part 50A, the abundance ratio of the first fiber 20 in the top part 50T with respect to the whole fiber constituting the convex part 50A is It becomes higher than the abundance ratio of the second fibers 40. At the same time, in the skirt part 50B of the convex part 50A, the existence ratio of the second fibers 40 in the skirt part 50B with respect to the entire fibers constituting the convex part 50A is higher than the existence ratio of the first fibers 20. Through these steps, it is possible to obtain a stacked body 50 in which a plurality of convex portions 50A are formed.

  As shown in FIG. 5, the width L of the opening 52a in the convex forming member 52 is preferably 400 μm or more and 10 mm. By having this width L, it is possible to form the protrusion 50A on the laminate 50, which has a good appearance and can reduce the resistance during wiping.

  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, it is possible to form a good convex portion 50A on the laminate 50.

  As another embodiment (hereinafter, referred to as a second embodiment) in the convex portion forming portion 5, as shown in FIGS. 6 and 7, in addition to the convex portion forming member 52, a second convex portion forming member 520 is used. Two types of convex portions 50A and second convex portions 520A can be formed on the stacked body 50 (hereinafter, the convex portions 50A are also referred to as first convex portions 50A in the second embodiment). In 2nd Embodiment, as shown in FIG. 6, the 2nd convex part formation member 520 is distribute | arranged so that it may overlap on the upper part of the above-mentioned convex part formation member 52. As shown in FIG. The second convex portion forming member 520 has a large number of square-shaped opening portions 520a regularly formed over the entire surface thereof. As shown in FIG. 8, the width La of the rectangular opening 520 a is larger than the width L of the opening 52 a of the convex forming member 52. In this way, by using the two types of convex forming members 52 and 520 in an overlapping manner, the first surface 50Y side of the wiping sheet 10 (hereinafter also referred to as wiping sheet 10 ′ in the second embodiment) is provided. The first protrusions 50 </ b> A can be formed in a shape such that the first protrusions 50 </ b> A protrude from the top of the second protrusions 520 </ b> A and are arranged in a large number and regularly.

  According to the second embodiment in which 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 closer to the first surface 50Y side of the wiping sheet 10 ′. A second convex portion 520A having a large macroscopic pattern (in the second embodiment, a rhombic lattice-like pattern), and the first convex portion 50A is positioned in the second convex portion 520A and is in two stages. A step is formed. In this case, in the top part of the first convex part 50A, the existence ratio of the first fibers 20 in the top part with respect to the whole fibers constituting the first convex part 50A is higher than the existence ratio of the second fibers 40, In addition, in the skirt portion of the first protrusion 50A, the existence ratio of the second fibers 40 in the skirt portion with respect to the entire fibers constituting the first protrusion 50A is higher than the existence ratio of the first fibers 20.

  In the second embodiment in which the two kinds of convex portion forming members 52 and 520 are used in an overlapping manner, as shown in FIG. 7, by the water flow sprayed from the second water flow nozzle 51 toward the surface 50X on the first fiber 20 side. The laminated body 50 is pressed so that the surface 50Y on the second fiber 40 side is in close contact with the second convex portion forming member 520. At this time, the first fibers 20 and the second fibers 40 enter the opening 520a, and a plurality of second protrusions 520A having a shape corresponding to the shape of the opening of the second protrusion forming member 520 are formed. Formed regularly. Further, the surface 50Y on the second fiber 40 side of the second convex portion 520A is pressed against the convex portion forming member 52 by the water flow blown from the second water flow nozzle 51, and the first convex portion 50A. Are formed so as to be regularly and regularly arranged on the top of the second convex portion 520A. As described above, the first convex portion 50A and the second convex portion 520A have a two-step height difference by forming a plurality of first convex portions 50A from the top of one second convex portion 520A. It becomes. 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-described process is from the first fiber 20 side surface (second surface) 50X to the second fiber side surface (first surface) 50Y side. The first convex portion 50A and the second convex portion 520A are formed so as to protrude toward the surface. 50 A of 1st convex parts and 520 A of 2nd convex parts have the shape raised from the flat surface of the 1st surface 50Y. Further, as described above, the first convex portion 50A is located in the second convex portion 520A, and has a shape raised from the top of the second convex portion 520A. By having these shapes, a convex portion having a two-step height difference is formed when viewed from the flat surface of the first surface 50Y. Depending on the manufacturing method of the wiping sheet 10 'in the second embodiment, the entire area of the second surface 50X may be a flat surface, and regions corresponding to the first convex portion 50A and the second convex portion 520A are present. It may be recessed.

  As shown in FIG. 8, the width La of the opening 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 protrusion 520A in the laminate 50, which has a good appearance and can reduce the resistance during wiping.

  As shown in FIG. 8, the thickness T of the second convex portion forming member 520 is preferably not less than 600 μm and not more than 4 mm, and more preferably not less than 700 μm and not more than 3 mm. By having the thickness within this range, it is possible to form the second convex portion 520A having a good appearance in the stacked body 50 and capable of reducing the resistance during 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 conveying belt 54, and the intended dry type is formed. The wiping sheet 10 (or wiping sheet 10 ′) can be obtained. Moreover, after conveying the laminated body 50 in which the convex portion 50 </ b> A is formed by the convex portion forming unit 5 from the convex portion forming unit 5 to the downstream by the conveying belt 54, it further corresponds to the second surface of the wiping sheet 10. It is also possible to supply and carry a wiping liquid from the surface side. By passing through this process, the target 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 wiping liquid carried is 6 g when the dimension of one wiping sheet is 285 mm × 205 mm as described in the examples described later. / Sheet or more is preferable, 8 g / sheet or more is more preferable, and 10 g / sheet or more is still more 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 still more preferably 20 g / sheet or less. As a method for supporting the wiping liquid, a method such as spraying, coating, or dipping can be used.

  The wiping sheet 10 (or wiping sheet 10 ') manufactured in this manner is attached to a cleaning tool such as a wiper sheet alone or a wiper and the like, such as buildings such as floor surfaces, wall surfaces, cupboards, window glass, mirrors. It can also be used for furniture such as doors and door knobs, furniture such as rugs, carpets, and desks, kitchens, toilets, body cleaning, hygiene products, and packaging.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in FIG. 2, the number and the water pressure of the first and second water flow nozzles 31 and 51 may be the same or different.

  Moreover, although the wiping sheet 10 (or wiping sheet 10 ′) of the above embodiment includes two types of fibers of the first and second fibers, the wiping sheet includes three or more types of fibers instead. It may be.

The present invention further discloses the following wiping sheet and the manufacturing method thereof for the above-described embodiment.
<1>
A first surface used as a wiping surface, the first surface including at least a first fiber and a second fiber having a diameter smaller than that of the first fiber; A wiping sheet having a second surface located on the opposite side of the surface,
The presence ratio of the second fiber is higher on the first surface than on the second surface;
A plurality of convex portions are formed on the first surface side,
The proportion of the first fibers at the top with respect to the entire fibers constituting the convex portion is higher than the proportion of the second fibers;
The wiping sheet in which the existence ratio of the second fibers in the skirt portion with respect to the entire fibers constituting the convex portion is higher than the existence ratio of the first fibers.

<2>
The wiping sheet according to <1>, wherein the first fiber and the second fiber are entangled without being thermally fused to each other.
<3>
The area ratio occupied by the second fibers in the first surface is preferably 40% or more and 99% or less, more preferably 45% or more and 95% or less, still more 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 the plurality of convex portions are regularly arranged.
<5>
Any one of the above <1> to <4>, wherein a 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 according to one item.
<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 the first fiber and / or the 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 of the wiping sheet and / or along the width direction.
<11>
The wiping sheet according to any one of <1> to <10>, wherein the convex portion has a width of 400 μm to 10 mm and a height of 110 μm to 25 mm.

<12>
The convex portion preferably has a width of 800 μm or more, more preferably 900 μm or more, further preferably a width W of 8 mm or less, and further preferably 5 mm or less, <1> Or the wiping sheet as described in any one of <11>.
<13>
The first surface side has the convex portion and a 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 two steps. Is formed,
In the top part of the convex part, the existence ratio of the first fiber in the top part with respect to the whole fibers constituting the convex part is higher than the existence ratio of the second fiber, and in the skirt part of the convex part, <1> to <12>, wherein the existence ratio of the second fibers in the skirt portion with respect to the whole fibers constituting the convex portion is higher than the existence ratio of the first fibers. Wiping sheet.
<14>
The wiping sheet according to <13>, wherein the convex portion is formed on a top portion of a second convex portion that is larger than the convex portion.
<15>
The wiping sheet according to <13>, wherein a plurality of the convex portions are formed on a top portion of the second convex portion.

<16>
The frictional force between the wiping target surface and the wiping sheet is preferably 10N or less, and the resistance force when wiping a wiping sheet having a size of 10 cm × 25 cm by applying a pressure of 55 N / m ² is 10 N or less. The wiping sheet according to any one of <1> to <15>, further preferably, and more preferably 4N or less.
<17>
The existence ratio of the first fiber and the second fiber at the top of the protrusion is such that the second fiber is 3 times or more of the first fiber on the basis of the number of the fibers constituting the protrusion, The wiping sheet according to any one of <1> to <16>.
<18>
The existence ratio of the first fiber and the second fiber in the skirt portion of the convex portion is such that the second fiber is more than twice the first fiber on the basis of the number of the 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 polyesters, polyamides, polyolefins, cellulose fibers, fibers made of various metals, glass, and minerals, and polyesters, polyamides, polyolefins, and cellulose fibers are preferable. <1> Thru | or the wiping sheet | seat as described in 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 of the same component.

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

<25>
The method for producing a wiping sheet according to any one of <1> to <24>,
A laminate of a fiber aggregate of a first fiber and a fiber aggregate of a second fiber having a smaller diameter than the first fiber, and a convex part in which the fiber aggregate of the second fiber has a plurality of apertures Under the state of being arranged so as to face the forming member, a water stream is blown from the fiber assembly side of the first fiber to entangle the first fiber and the second fiber, and at the opening portion. A method for manufacturing a wiping sheet in which the fiber assembly is projected into the opening.
<26>
The method for producing a wiping sheet according to <25>, wherein the fiber aggregate of the second fibers is formed by a melt-type electrospinning 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 using the manufacturing apparatus 1 and the convex portion forming member 52 shown in FIGS. 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 electrospinning 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, and its dimensions were 285 mm × 205 mm and the thickness T was 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 occupied by the second fibers 40 in the first face 50Y was 90%, and the area ratio occupied by the second fibers 40 in the second face 50X was 5%. The proportion of the first fibers 20 in the top 50T with respect to the entire fibers constituting the convex portion 50A is twice as large as the second fiber 40 in terms of area (67% as the area ratio), and constitutes the convex portion 50A. The existence ratio of the second fibers 40 in the skirt portion 50 </ b> B with respect to the entire fibers to be performed was 1.1 times (52% as an area ratio) on the basis of the area of the first fibers 20.
The wiping sheet 10 of Example 1 carried a wiping liquid to form a wet wiping sheet. The wiping liquid was carried at least on the fiber assembly located on the second surface side. The carrying amount of the wiping liquid was 20 g / sheet. As the wiping solution, a 0.01% by mass aqueous solution of a surfactant (Emulgen 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 carried on the wiping sheet of Example 1. That is, the wiping sheet of Example 2 is a dry type.

[Comparative Example 1]
As a wet wiping sheet, a wet sheet for Scotch Bright (registered trademark) floor manufactured by 3M was used. The 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 Scotch Bright (registered trademark) manufactured by 3M was used for 24 hours in an environment of a temperature of 20 ° C. and a relative humidity of 65%. The 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 superfine adsorption dry sheet manufactured by Yamazaki Sangyo Co., Ltd. was used. The 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 Example and Comparative Example, and an area of 1.8 m ² was wiped using a flooring (Combit New Advance 101, manufactured by Wood One) as a wiping target surface. The resistance force was measured by the method described above. The results are shown in FIGS.

  As a result of comparing the resistance in Example 1 and Comparative Example 1 which are wet wiping sheets, the resistance in Example 1 was 2.7 N 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 resistance in Example 2 and Comparative Examples 2 and 3 which are dry wiping sheets, the resistance in Example 2 was 1.8 N as shown in FIG. On the other hand, the resistance of Comparative Example 2 was 2.2N, and the resistance of Comparative Example 3 was 4.1N. From these results, it can be seen that the dry-type wiping sheet 10 in Example 2 has low frictional resistance during wiping and high operability, similar to the wet-type wiping sheet 10 in Example 1.

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

DESCRIPTION OF SYMBOLS 1 Wiping sheet manufacturing apparatus 2 Web forming part 3 Entangling part 4 Electrostatic spinning part 5 Convex part forming part 10 Wiping sheet 20 1st fiber 40 2nd fiber 50A Convex part 50Y 1st surface 50X 2nd surface

Claims (8)

A first surface used as a wiping surface, the first surface including at least a first fiber and a second fiber having a diameter smaller than that of the first fiber; A wiping sheet having a second surface located on the opposite side of the surface,
The presence ratio of the second fiber is higher on the first surface than on the second surface;
A plurality of convex portions are formed on the first surface side,
The proportion of the first fibers at the top with respect to the entire fibers constituting the convex portion is higher than the proportion of the second fibers;
The wiping sheet in which the existence ratio of the second fibers in the skirt portion with respect to the entire fibers constituting the convex portion is higher than the existence ratio of the first fibers.   The wiping sheet according to claim 1, wherein the plurality of convex portions are regularly arranged.   The wiping sheet according to claim 1, wherein the convex portion has a width of 400 μm to 10 mm and a height of 110 μm to 25 mm. The first surface side has the convex portion and a 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 two steps. Is formed,
In the top part of the convex part, the existence ratio of the first fiber in the top part with respect to the whole fibers constituting the convex part is higher than the existence ratio of the second fiber, and in the skirt part of the convex part, The wiping sheet according to any one of claims 1 to 3, wherein a presence ratio of the second fibers in the skirt portion with respect to the entire fibers constituting the convex portion is higher than a presence ratio of the first fibers. .   The wiping sheet according to any one of claims 1 to 4, wherein the wiping liquid is carried at least on a fiber assembly located on the second surface side.   The wiping sheet according to claim 5, further comprising a wiping liquid release layer and a liquid retaining layer that supports the wiping liquid, wherein the release layer includes a first surface. A method for manufacturing a wiping sheet according to any one of claims 1 to 6,
A laminate of a fiber aggregate of a first fiber and a fiber aggregate of a second fiber having a smaller diameter than the first fiber, and a convex part in which the fiber aggregate of the second fiber has a plurality of apertures Under the state of being arranged so as to face the forming member, a water stream is blown from the fiber assembly side of the first fiber to entangle the first fiber and the second fiber, and at the opening portion. A method for manufacturing a wiping sheet in which the fiber assembly is projected into the opening.   The method for producing a wiping sheet according to claim 7, wherein the fiber aggregate of the second fibers is formed by a melt-type electrospinning method.