JP2019208949A - Wiping sheet - Google Patents

Abstract

To provide a wiping sheet for reduction of costs of manufacture, having both high collection performance of dirt and excellent tactile.SOLUTION: A wiping sheet comprises: a central area having a first surface used as a wiping surface and a second surface positioned at an opposite side to the first surface, positioned in the center in the width direction, and extending in the longitudinal direction; and a pair of lateral areas adjacent to the central area and extending in the longitudinal direction. The central area includes first fibers and second fibers having a smaller diameter than the first fibers, a presence ratio of the second fibers is higher in the first surface than the second surface, and each of the lateral areas includes the first fibers, and does not include the second fibers excluding the case of being inevitably included.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wiping sheet.

  Fibers made from thermoplastic resins are used in various applications in the form of nonwoven fabrics entangled with the fibers. For example, Patent Document 1 discloses a cleaning wet sheet in which a liquid holding sheet, a liquid impermeable sheet, and a liquid sustained release sheet are arranged. The document also discloses that the liquid holding sheet and the liquid sustained release sheet are made of a fiber material, and the air permeability of the liquid sustained release sheet is lower than the air permeability of the liquid holding sheet.

JP 2004-105710 A

  Since the cleaning wet sheet of Patent Document 1 is manufactured by laminating a plurality of sheets, there is room for improvement from the viewpoint of manufacturing efficiency such as manufacturing cost. In addition, when the fiber of the wet sheet of the same document is a thin fiber having a fiber diameter of about 1 μm, the fine fiber is easily clinged to the hand when the wet sheet is taken out from the package and gripped, and the feel of the sheet is deteriorated. There was a possibility. Furthermore, there is no disclosure of dirt collection efficiency or sheet tactile sensation when the wet sheet of the same document is used as a dry mode.

  Therefore, the subject of this invention is providing the wiping sheet which can solve the subject of a prior art.

The present invention has a first surface used as a wiping surface, and a second surface located on the opposite side of the first surface,
A central region located in the center of the width direction and extending in the longitudinal direction; and a pair of side regions adjacent to the central region and extending in the longitudinal direction;
The central region includes a first fiber and a second fiber having a smaller diameter than the first fiber, and the presence ratio of the second fiber is higher on the first surface than on the second surface. ,
Each of the lateral regions provides a wiping sheet that includes the first fiber and does not contain the second fiber unless it is inevitably contained.

  According to the present invention, it is possible to provide a wiping sheet that has reduced manufacturing costs, high dirt collection performance, and good tactile sensation.

Fig.1 (a) is a schematic diagram which shows one Embodiment of the wiping sheet | seat of this invention, FIG.1 (b) is sectional drawing in the AA line of Fig.1 (a). FIG. 2 is an exploded perspective view when the wiping sheet of the present invention is attached to the cleaning tool. FIG. 3 is a schematic view showing an embodiment of the wiping sheet manufacturing apparatus of the present invention. FIG. 4 is a schematic view showing another embodiment of the wiping sheet of the present invention. FIG. 5 is a graph showing the cleaning liquid discharge efficiency of the wiping sheets of Examples and Comparative Examples.

  Hereinafter, the wiping sheet of the present invention will be described based on preferred embodiments thereof. The wiping in the present invention includes both the meanings of 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 In this specification, the term “wiping sheet” refers to a sheet impregnated with a cleaning liquid and a sheet not impregnated with a cleaning liquid, depending on the context.

  The wiping sheet includes a fiber assembly including at least a first fiber and a second fiber having a smaller diameter than the first fiber. These fibers may be entangled with each other to form an integral fiber assembly, and the fiber layer made of the first fiber and the fiber layer made of the second fiber are joined or fused together to be integrated. Also good. The wiping sheet of the present invention may be composed of only a fiber assembly, or may include other sheet materials or other members in addition to the fiber assembly. The wiping sheet of the present invention may be a fiber assembly that is not impregnated with a cleaning liquid (hereinafter, this embodiment is also referred to as “dry type”), or may be a fiber assembly that is impregnated with a cleaning liquid (hereinafter referred to as “drying”). This embodiment is also referred to as “wet”).

  FIG. 1 shows an embodiment of the wiping sheet of the present invention. The wiping sheet 1 has a first surface 1F and a second surface 1R located on the opposite side of the first surface 1F. The first surface 1F is used as a wiping surface when the wiping sheet 1 is used. Therefore, the lower side of the figure is the second surface 1R located on the opposite side of the wiping surface.

  The wiping sheet shown in FIG. 1A has a rectangular shape having a longitudinal direction X and a width direction Y orthogonal to the longitudinal direction X. The wiping sheet shown in the figure has, in its width direction Y, a central area CA located at the center of the width direction Y and a pair of side areas SA, SA adjacent to the central area CA. Each of the central area CA and the side area SA has a rectangular shape continuously extending along the longitudinal direction X of the wiping sheet 1. The central area CA is located at the center in the width direction Y of the wiping sheet 1. In particular, the central area CA is preferably located at the center of the wiping sheet 1 in the width direction. The two side areas SA, SA are preferably the same width. The positions of the front and rear ends of the central area CA coincide with the positions of the front and rear ends of each side area SA. Therefore, the wiping sheet 1 has a symmetrical shape with respect to the vertical center line that bisects the wiping sheet 1 to the left and right.

  The above-described central area CA and side area SA have different fiber compositions. Specifically, the central area CA includes at least both the first fibers 11 and the second fibers 12 having a smaller diameter than the fibers. On the other hand, the side area SA includes the first fibers 11 and the second fibers 12 are not included except when they are inevitably included. That is, the side area SA is substantially free of the second fibers 12. The fact that the second fiber is inevitably contained means that the second fiber 12 is unintentionally mixed into the side area SA in the manufacturing process of the wiping sheet 1.

With such a configuration, fine dirt with a particle diameter of about 10 nm to 25 μm is efficiently collected with a dense and low porosity structure formed by the second fibers 12 existing in the central area CA. In addition, it is possible to collect fiber stains such as hair with a high porosity structure formed by the first fibers 11, and to collect these stains. As a result, the collection performance of fine particles and fiber dirt can be improved. Moreover, since the usage-amount of the 2nd fiber 12 at the time of manufacture can be reduced, manufacturing cost can be reduced. Furthermore, since the side area SA is often gripped when the wiping sheet is taken out of the package, the sheet is made substantially free of the second fibers 12 having a small diameter in the side area SA. The tactile sensation during gripping can be improved. “Substantially free” means that the ratio of the second fibers 12 to the first fibers existing in the lateral area SA is less than 8% as a mass ratio.

  As shown in FIG. 1B, in the central area CA, in the cross-sectional view in the thickness direction Z, the locations where the first fibers 11 and the second fibers 12 are present are unevenly distributed. Specifically, in the central area CA, the presence ratio of the second fibers 12 is higher on the first surface 1F that is the wiping surface than on the second surface 1R. Moreover, in the 1st surface 1F, the 2nd fiber 12 exists over the whole area of the surface direction of central area CA, maintaining the state with the high existence ratio. By adopting this configuration, in addition to a reduction in manufacturing cost and a good tactile feel of the sheet, it also has a high dirt collecting performance. Further, when the wiping sheet is in a wet mode, the effect of improving the sustained release property of the cleaning liquid can be obtained even when a wide range is targeted for cleaning.

  In addition, in FIG.1 (b), although the 1st fiber 11 and the 2nd fiber 12 are isolate | separated, this is only expressed as such for convenience of explanation, and actually Are not separated from each other. In addition, in the same figure, both the first fiber 11 and the second fiber 12 are shown as wavy lines and unevenly shaped, but this is also shown as such for convenience of explanation. It does not need to be unevenly shaped.

  From the viewpoint of more effective reduction in manufacturing cost and high removal efficiency of dirt, the ratio of the area of the central area CA to the area of the wiping sheet 1 is preferably 30% or more, and more than 35%. More preferably, it is preferably 65% or less, and more preferably 60% or less. That is, when viewed from the first surface 1F, the area of the region where the second fibers 12 are present relative to the area of the wiping sheet 1 is preferably within the above-described range.

  From the same viewpoint, in a plan view when the wiping sheet 1 is viewed from the first surface 1F, the length in which the central area CA in the width direction Y exists is relative to the length in the width direction Y of the wiping sheet 1. It is preferably 20% or more, more preferably 30% or more, more preferably 80% or less, and still more preferably 60% or less. Further, from the same viewpoint, the central area CA is preferably arranged so as to straddle a center line (not shown) extending in the longitudinal direction of the wiping sheet.

  From the viewpoint of improving the good feel of the sheet and the sustained release property of the cleaning liquid in the wet mode, the ratio of the area of each lateral region to the area of the wiping sheet 1 is preferably 17.5% or more independently of each other. 20% or more, more preferably 30% or less, and further preferably 32.5% or less. That is, when viewed from the first surface 1F, the area of the region in which the second fibers 12 are substantially not contained with respect to the area of the wiping sheet 1 is preferably in the above-described range.

  From the same viewpoint, in a plan view when the wiping sheet 1 is viewed from the first surface 1F, the length in which the side area SA in the width direction Y exists is relative to the length in the width direction Y of the wiping sheet 1. Independently, it is preferably 10% or more, more preferably 20% or more, further preferably 40% or less, and further preferably 30% or less.

  The area of the central area CA and the side area SA can be measured based on the presence or absence of the second fibers 12 in the observation target area using, for example, a scanning electron microscope or a confocal laser microscope. The case where a confocal laser microscope is used will be described as an example. The image data of the first surface 1F and the second surface 1R is acquired, and the obtained images are processed with the first fiber using image processing software such as ImageJ. A threshold value is set at the brightness boundary between the second fiber and the second fiber, and the brightness is binarized. At this time, since the second fiber is substantially not contained in the side region, the boundary between the region including the second fiber and the region not including the second fiber is respectively defined between the central region and the side region. It can be a boundary with a region. Each area is calculated from each region determined by observation. Thereafter, the area ratio of the central area CA and the lateral area SA can be obtained by dividing each calculated area by the area of the entire wiping sheet.

  The wiping sheet of the present invention can be used for wiping with a single wiping sheet. In this case, it is preferable to use only the central area CA for wiping. Moreover, the wiping sheet | seat of this invention can also be used for wiping as an aspect of the cleaning tool 100 with which the cleaning tool 120 provided with the head part 110 which can mount | wear with the wiping sheet 1 as shown in FIG. The head portion 110 is a rectangular member, and a locking portion that locks the wiping sheet 1 is provided on a surface opposite to the facing surface 110A (not shown). The head portion 110 can be attached with a wiping sheet so that the second surface 1R of the wiping sheet 1 and the facing surface 110A of the head portion 110 face each other and the facing surface 110A is covered. Moreover, the cleaning tool 120 is comprised, for example from the rod-shaped member which can be extended-contracted or can be extended by an assembly, the member which has a handle, or the member which combined these.

  As shown in FIG. 2, the width of the facing surface 110A of the head portion and the width of the central area CA are substantially the same. Therefore, when attaching the wiping sheet 1 to the cleaning tool 120, the central area CA is disposed so as to substantially coincide with the facing surface 110A of the head portion, and the first surface 1F is opposed to the wiping object. It is preferable in terms of enhancing the dirt collection performance. In addition, the pair of side areas SA and SA are folded at the areas extending from the side edges of the head part 110, and are locked to the opposite side of the facing surface 110A by the locking part described above.

  In general, when the wiping sheet 1 is attached to a cleaning tool, the lateral area SA of the wiping sheet 1 is taken out from the package while being manually gripped, and the lateral area SA is engaged with the engaging portion of the head portion 110. Since it stops, the opportunity to touch side area SA increases. At this time, if the fine fibers are present in the side area SA, the fine fibers are clinging to the fingers, and when wet, it is easy to perceive slipping and stickiness caused by the cleaning liquid. It is difficult for the touch to be good. In contrast to this, the side area SA in the wiping sheet of the present invention is substantially free of the second fibers 12 that are thin fibers, so that the fibers are clinging to the fingers, Sliding and stickiness caused by the cleaning liquid can be reduced. As a result, the feel of the wiping sheet can be improved.

  Focusing on the contact with the wiping target surface during wiping, the central area CA can be brought into contact with the wiping target surface to contribute to wiping. On the other hand, since the area extending from the side edge of the head part 110 is folded back, the side area SA has a smaller contact area with the wiping target surface than the central area CA, or the side area SA and the wiping target surface. Therefore, the wiping contribution ratio of the side area SA is smaller than the contribution ratio of the central area CA. Thus, since the 1st fiber 11 and the 2nd fiber 12 are distribute | arranged to the central area CA, the wiping sheet | seat of this invention can make dirt collection performance high. In addition, since the range of the central area CA is limited, it is not necessary to arrange the second fibers 12 in the side area that is difficult to contribute to wiping, resulting in a reduction in manufacturing cost.

  When paying attention to the central area CA of the wiping sheet 1, it is preferable that the existence ratio of the constituent fibers of the first surface 1F and the second surface 1R is in a predetermined range. Specifically, the proportion of the first fibers 1F in the central area CA occupied by the second fibers 12 is preferably 40% or more, more preferably 50% or more, expressed as an area ratio. % Or more, more preferably 100% or less, more preferably 90% or less, and still more preferably 85% or less. The proportion of the second fibers 12 in the first surface 1F is preferably 40% or more and 100% or less, more preferably 50% or more and 90% or less, and more preferably 60% or more, expressed as an area ratio. More preferably, it is 85% or less. By being in such an abundance ratio, fine particle dirt can be efficiently collected with a dense and low porosity structure formed by fine fibers, and the sustained release property of the cleaning liquid in a wet mode Can be increased.

  The abundance ratio of the first fibers 11 on the first surface 1F in the central area CA is expressed as an area ratio, preferably 0% or more, more preferably 1% or more, and 5% or more. More preferably, it is preferably 60% or less, more preferably 40% or less, and further preferably 35% or less. The abundance ratio of the first fibers 11 in the first surface 1F in the central area CA is preferably 0% or more and 60% or less, more preferably 1% or more and 40% or less, expressed as an area ratio. More preferably, it is 5% or more and 35% or less. By having such a presence ratio, it is possible to easily retain the dirt collected between the constituent fibers of the wiping sheet by the high porosity structure formed by the large diameter fibers. Moreover, the sustained release property of the cleaning liquid in the wet mode can be enhanced.

  Similarly, the proportion of the second surface 1R in the central area CA occupied by the second fibers 12 is expressed as an area ratio, preferably 1% or more, more preferably 3% or more, and 5%. More preferably, it is 60% or less, more preferably 40% or less, and further preferably 35% or less. The abundance ratio of the second fibers 1 in the second surface 1R in the central area CA is expressed as an area ratio, and is preferably 1% or more and 60% or less, and more preferably 3% or more and 40% or less. More preferably, it is 5% or more and 35% or less.

  Similarly, the proportion of the first fibers 11 in the second surface 1R in the central area CA is preferably 50% or more, more preferably 65% or more, expressed as an area ratio, 70 % Or more, more preferably 100% or less, more preferably 90% or less, and still more preferably 87% or less. The ratio of the first fibers 11 in the second surface 1R in the central area CA is preferably 50% or more and 100% or less, more preferably 65% or more and 90% or less, expressed as an area ratio. 70% to 87% is more preferable.

  The existence ratio of the first fibers 11 and the second fibers 12 in the central region can be measured as an area ratio using, for example, a confocal laser microscope. Specifically, the image data is respectively acquired with the central area CA located on the first surface 1F and the second surface 1R as an observation target. Each image obtained is set to a lightness boundary between the first fiber and the second fiber using image processing software such as ImageJ, and the lightness is binarized. Then, the area which has each color is calculated, and the area ratio of each fiber is calculated.

  When a virtual surface parallel to the wiping surface is considered, the wiping sheet is represented by the area ratio of the second fiber in the virtual surface and is directed to the thickness direction Z on the opposite side of the wiping surface. Thus, it is preferable to decrease stepwise, continuously, or a combination thereof. In particular, with reference to the surface opposite to the wiping surface, the second portion of the virtual surface parallel to the wiping surface is a portion extending from 50% to 100% of the thickness of the wiping sheet along the thickness direction Z of the wiping sheet. The amount of the fibers occupied by the fibers can be expressed in terms of area ratio and in the range of 50% or more and 100% or less, so that the loading amount of the cleaning liquid can be increased. Here, the ratio of the thickness that the second fiber occupies in the range of 50% to 100% in terms of area ratio is preferably 1% to 90%, preferably 5% to 70%. % Or less is more preferable, and 7% or more and 50% or less is still more preferable. This area ratio can be calculated by, for example, Raman imaging using a confocal laser microscope as described above.

  When the wiping sheet is in a wet mode, it is preferable that the capillary pressure on the first surface 1F side is higher than the capillary pressure on the second surface 1R. By having such a configuration, the sustained release performance of the cleaning liquid can be enhanced. 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 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 obtained 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 of the liquid 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 capillary 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 of the present invention, since the second fibers 12 that are thin fibers are arranged in the central area CA, the central area CA is an area where the capillary pressure is high. Moreover, since the fiber assembly located in the side area SA and the second surface 1R side in the first surface 1F has a high existence ratio of the first fibers 11 having a large diameter, the fiber assembly There are more voids than the fiber aggregate on the first surface 1F side, and the cleaning liquid is easily held in the voids. As described above, when the wiping sheet of the present invention is in a wet mode, the side area SA where the contribution of wiping is low compared to the case where the second fibers 12 are arranged on the entire first surface 1F. While preventing the unintentional sustained release of the cleaning liquid from being produced, it is possible to increase the sustained release of the cleaning liquid in the central area CA.

  When the wiping sheet of the present invention is a wet mode, it is preferable that the cleaning liquid is supported at least on the fiber assembly located on the second surface side. “At least the cleaning liquid is carried on the fiber assembly on the opposite side of the wiping surface” is an aspect in which the fiber assembly on the opposite side of the wiping surface contains the cleaning liquid, and the fiber assembly on the wiping surface side also contains the cleaning liquid in the gap. Embodiments are also included. The amount of the cleaning liquid supported is preferably larger than the amount supported on the fiber assembly on the second surface 1R side.

  The wiping sheet 1 may use the fiber assembly including the first fiber 11 and the second fiber 12 as it is (so-called dry mode) at the time of wiping. It may be used in a supported or impregnated mode (so-called wet mode). These aspects can be selected according to the type of dirt adhering to the surface to be wiped and the physical properties of the object to be wiped. From the viewpoint of increasing the removal efficiency of dirt on the surface to be wiped, it is preferable that a cleaning liquid is carried on the fiber assembly constituting the wiping sheet.

  When the wiping sheet is used in a wet mode, the cleaning liquid impregnated and supported on the sheet may have a general composition used for a wet wiping sheet, such as water alone or an aqueous solution containing an additive. . Examples of the additive used in the cleaning liquid include surfactants, bactericides, fragrances, fragrances, deodorants, pH adjusters, alcohol, and abrasive particles. It is preferable to contain at least an agent. In this case, the content of the surfactant in the cleaning liquid can be 0.01% by mass or more and 1% by mass or less.

  The first fibers 11 and the second fibers 12 constituting the wiping sheet 1 may be either synthetic fibers or natural fibers. Synthetic fibers include, for example, polyolefin fibers such as polyethylene and polypropylene, polyester fibers such as polyethylene terephthalate, polyolefin / polyester mixed fibers such as polyethylene / polyethylene terephthalate and polypropylene / polyethylene terephthalate, polyamide fibers such as nylon 6 and nylon 66, poly Examples thereof include vinyl fibers such as vinyl chloride and polystyrene, and acrylic fibers such as polyacrylic acid and polymethyl methacrylate. Examples of natural fibers include various cellulose fibers such as pulp, cotton, rayon, lyocell, and tencel. These fibers can be used singly or in combination of two or more.

  The first fibers 11 and the second fibers 12 are preferably different in color. In other words, it is preferable that the colors of the central area CA where the second fibers 12 exist and the side areas SA substantially free of the second fibers 12 are different from each other. With such a configuration, when the wiping sheet 1 is viewed from the first surface 1F side, color contrast occurs between the central area CA and the lateral area SA, and the central area CA and the lateral area SA It is possible to easily determine the boundary between the two. In addition, when attaching the wiping sheet to the cleaning tool, the gripping position and the position of the cleaning surface can be easily determined, and as a result, unintentional clinging of small-diameter fibers can be prevented and the feel of the sheet can be increased. it can. In order to make the colors of the fibers 11 and 12 different, for example, in the manufacturing process of each fiber, a colorant having a different color is added to at least one fiber, or the content of the same kind of colorant is changed. Can be done.

  From the viewpoint of increasing the degree of freedom of the constituent fibers and improving the dirt collecting performance, the fibers constituting the wiping sheet are entangled without fusing the first and second fibers and the second fibers. It is preferable. By having such a configuration, it is possible to enhance the collection performance of fine particle dirt, and when the wiping sheet is used as a wet mode, an advantage that the carrying amount of the cleaning liquid per unit area increases. Is also played.

  From the viewpoint of enhancing the dirt collecting property, the fiber diameter (diameter) of the first fiber 11 is preferably 10 μm or more and 30 μm or less, and more preferably 15 μm or more and 25 μm or less. Further, the fiber diameter (diameter) of the second fiber 12 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 constituting the fiber assembly 1A may be continuous filaments or staple fibers, depending on the method of manufacturing the fiber assembly 1A. In the case of staple fibers, the average fiber length is generally preferably from 1 mm to 100 mm, more preferably from 10 mm to 90 mm, and even more preferably from 20 mm to 60 mm.

The basis weight of the wiping sheet 1 is preferably 50 g / m ² or more, more preferably 52 g / m ² or more, and still more preferably 55 g / m ² or more. The basis weight of the wiping sheet 1 is preferably 90 g / ^{m 2} or less, more preferably 87 g / ^{m 2} or less, 85 g / ^{m 2} or less is more preferable. Specifically, the basis weight of the wiping sheet 1 is preferably 50 g / m ² or more and 90 g / m ² or less, more preferably 52 g / m ² or more and 87 g / m ² or less, and 55 g / m ² or more and 85 g / m ² or less. Is more preferable.

The basis weight of the first fiber constituting the wiping sheet is preferably 40 g / m ² or more, more preferably 42 g / m ² or more, and 45 g / m ² or more, provided that the basis weight of the wiping sheet is satisfied. Is more preferable. The basis weight of the first fiber is preferably 87 g / m ² or less, more preferably 85 g / m ² or less, and still more preferably 83 g / m ² or less. Specifically, the basis weight of the first fibers constituting the wiping sheet is preferably 40 g / m ² or more and 87 g / m ² or less, provided that the basis weight of the wiping sheet is satisfied, and 42 g / m ^2. It is more preferably 85 g / m ² or less, and still more preferably 45 g / m ² or more and 83 g / m ² or less.

The basis weight of the second fiber constituting the wiping sheet is preferably 1 g / m ² or more, more preferably 3.5 g / m ² or more, provided that the basis weight of the wiping sheet described above is satisfied. 4 g / m ^Two or more are more preferable. The basis weight of the second fiber is preferably from 22.5 g / ^{m 2} or less, more preferably 10 g / ^{m 2} or less, more preferably 8 g / ^{m 2} or less. Specifically, the basis weight of the first fiber constituting the wiping sheet is preferably 3 g / m ² or more and 10 g / m ² or less, provided that the basis weight of the wiping sheet is satisfied, and 3.5 m ^2. It is more preferably 9 g / m ² or less, and still more preferably 4 g / m ² or more and 8 g / m ² or less. As described above, when the basis weight of the first fiber and the second fiber is within these ranges, the first fiber and the second fiber are more three-dimensionally produced when the fiber assembly is manufactured. Can be entangled. As a result, it is possible to achieve both the sustaining discharge of the cleaning liquid in the wiping sheet and the improvement in operability during use.

  From the viewpoint of suppressing the frictional resistance during wiping, it is preferable that at least the first surface 1F of the wiping sheet 1 has an uneven portion of a macroscopic pattern having a curved portion. As such a pattern, for example, a macroscopic pattern disclosed in JP 2017-113282 A or a macroscopic pattern in which figures such as straight lines, curves, circles, and polygons are appropriately combined may be used. In addition, when viewed macroscopically, a curved shape is a figure that forms a concavo-convex portion except a curve that forms a microscale fine hole or a curve that forms a drainage hole having a diameter of about 1.5 to 2 mm. This means that it can be visually confirmed that a part of the side is a curve. By having such a macroscopic pattern uneven part, there is also an advantage that the design of the wiping sheet itself is improved.

  The above is a description of one embodiment of the wiping sheet of the present invention. Hereinafter, a preferred method for manufacturing a wiping sheet will be described with reference to the manufacturing apparatus 10 shown in FIG. A manufacturing apparatus 10 suitably used for manufacturing a wiping sheet includes a first original fabric roll 21, a second original fabric roll 22, and an entanglement device 30.

  First, the first fiber 11 while the fiber sheet of the first fiber 11 and the fiber sheet of the second fiber 12 are respectively fed out and conveyed in the conveying direction MD from the first original fabric roll 21 and the second original fabric roll. A fiber sheet of the second fibers 12 is laminated on the upper surface of the fiber sheet to form a belt-like laminate 1S extending in the transport direction MD (lamination process).

  At this time, the length in the width direction Y of the fiber sheet of the second fiber 12 is the width direction of the fiber sheet of the first fiber 11 from the viewpoint that the central area CA and the side area SA can be more easily formed. It is preferable to make it shorter than the length in Y. Moreover, it is also preferable to laminate | stack so that the longitudinal center line (not shown) which bisects the fiber sheet of each fiber 11 and 12 in the width direction Y may correspond substantially. As the fiber sheet of each of the fibers 11 and 12, for example, a fiber sheet manufactured by a melt blown method, an electrospinning method, a spunlace method (a hydroentanglement method), a needle punch method, an airlaid method, or the like can be used.

  Next, in the entanglement device 30, the constituent fibers of the laminate 1S are entangled to obtain a fiber assembly 1P of the first fibers 11 and the second fibers 12 (entanglement step). The entanglement method in the entanglement device 30 is not particularly limited, and examples thereof include a needle punch method, a spunlace method (a hydroentanglement method), and a steam jet method. This step may be performed only once or a plurality of times.

As the entanglement method, for example, when the constituent fibers of the laminate 1S are entangled by the needle punch method, the constituent fibers are entangled by performing the entanglement by the needle punch method at a needle density of 150 / cm ² and a roll rotation speed of 8 m / min. be able to.

Moreover, as a confounding method, for example, when the constituent fibers of the laminate 1S are entangled by the hydroentanglement method, the high pressure ejected from a water flow nozzle (not shown) provided on the surface side facing the laminate 1S of the confounding device 30 is used. The constituent fibers are entangled three-dimensionally by the water flow. At this time, the water pressure blown from the water flow nozzle is preferably 30 kg / cm ² or more and 80 kg / cm ² or less, more preferably 40 kg / cm ² or more and 60 kg / cm ² or less, and the conveyance speed in the MD direction of the laminate 1S is preferably It can be produced at a rate of 2 m / min to 10 m / min, more preferably 4 m / min to 8 m / min.

  Subsequently, the formed strip-shaped fiber assembly 1P is cut to have a predetermined size, whereby the wiping sheet 1 is manufactured. In this manufacturing method, the wiping sheet 1 is manufactured so that the longitudinal direction thereof matches the MD direction, and the upper surface of the fiber assembly 1P becomes the first surface 1F of the wiping sheet, and the lower surface of the fiber assembly 1P is It is manufactured so as to be the second surface 1R of the wiping sheet. Thus, the wiping sheet 1 is formed so that the central area CA located in the center in the width direction and the pair of side areas SA extend in the longitudinal direction X.

The wiping sheet 1 may be used in a dry mode as it is, or alternatively, a wet mode in which a cleaning liquid is supported. When the wiping sheet 1 is in a wet mode, the amount of the cleaning liquid impregnated is preferably 1 g / sheet or more when the dimension of the wiping sheet 1 is 285 mm × 205 mm as described in the examples below. More preferably, it is 40 g / sheet or less, more preferably 25 g / sheet or less. In other words, preferably 17 g / ^{m 2} or more, more preferably 117 g / ^{m 2} or more, preferably 690 g / ^{m 2} or less, more preferably 430 g / ^{m 2} or less.

  The wiping sheet manufactured in this manner is attached to a cleaning tool such as a wiper sheet alone or a wiper, and flooring, wall and other buildings, cupboards, window glass, mirrors, doors, door knobs and other fittings, It can be used for furniture such as rugs, carpets, desks, kitchens, toilets, body cleaning, sanitary 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. As another embodiment of the wiping sheet of the present invention, for example, as shown in FIG. 4, the end portion in the longitudinal direction X of the central area CA and the end portion in the longitudinal direction X of the wiping sheet are not aligned. Also good. In this case, the region other than the central region includes the first fiber 11 and the second fiber 12 is a substantially non-contained region except when it is inevitably contained. preferable.

  Moreover, although the wiping sheet of the said embodiment contained two types of fibers, the 1st and 2nd fiber, it replaced with this and may be a wiping sheet containing 3 or more types of fibers.

  Moreover, when forming the uneven | corrugated | grooved part of the macroscopic pattern which has a curve part in the 1st surface 1F of the wiping sheet 1, for example, the formation member which has a shape complementary to the macroscopic pattern to form is used for the laminated body 1S or fiber It can be formed by placing the second fiber 12 of the assembly 1P on the surface side where the second fibers 12 are disposed and applying a high-pressure water flow from the opposite surface.

  Further, the wiping sheet of the present invention may further include a scrim that supports the sheet. The scrim can be integrally entangled with the constituent fibers of the wiping sheet, and examples thereof include a lattice shape, a net shape, and a strand shape. By providing the wiping sheet with the scrim, there is an advantage that the wiping sheet 1 can have a practically sufficient strength.

  Examples of the raw material constituting the scrim include polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon 6 and nylon 66, acrylonitrile resins such as polyacrylonitrile, and vinyls such as polyvinyl chloride and polystyrene. Resin, vinylidene resin such as polyvinylidene chloride, and the like can be used.

  The wire diameter (diameter in the cross section) of the scrim can be appropriately adjusted according to the degree of entanglement with the fiber assembly 1A, but is preferably 10 μm or more and 2000 μm or less. The wire diameters of the scrims may be partially different or the same. If the wire diameters are partially different, the scrim wire diameter is the average value.

  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]
Dry and wet wiping sheets were manufactured according to the manufacturing method described above. The first fiber 11 is 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, the mixed cotton body has a wire diameter of 500 μm, and the distance between lattices is vertical and horizontal. Both were spunlace nonwoven fabrics hydroentangled with a 10 mm grid scrim. A non-woven fabric made of polypropylene having an average diameter of 1 μm obtained by electrospinning was used as the second fiber 12. The basis weight of the spunlace nonwoven fabric was 60 g / m ^2, and the basis weight of the electrospun nonwoven fabric was 5 g / m ² . These fibers were hydroentangled to obtain a fiber assembly having a basis weight of 65 g / m ² . This was used as a wiping sheet of the dry type shown in FIG.

  Moreover, the above-mentioned fiber assembly was impregnated with a cleaning liquid to produce a wet-type wiping sheet. The cleaning liquid was impregnated so as to be supported at least on the fiber assembly located on the second surface side. The impregnation amount of the cleaning liquid was 20 g / sheet. As the cleaning liquid, a 0.01% by mass aqueous solution of a surfactant (Emulgen (registered trademark) 108, manufactured by Kao Corporation) was used. Thus, it was used as a wiping sheet of a wet mode shown in FIG.

  In any embodiment, the area ratio of the central area to the area of the wiping sheet is 60%, and the area ratio of each lateral area is 20%. In addition, the existence ratio of the second fibers 12 in the central area of the first surface 1F was 49% as the area ratio of the fibers. The ratio of the second fibers in the thickness direction in the central area of the first surface 1F was 12%. The wiping sheet was rectangular, and its dimensions were 285 mm × 205 mm.

[Comparative Example 1]
After the fiber assembly was produced in the same manner as in Example 1, heat sealing treatment was performed only on the side areas, and both sides were filmed to make the fibers non-existent. Others were manufactured in the same manner as in Example 1 to obtain dry and wet wiping sheets.

[Comparative Example 2]
Except for impregnating the fiber assembly consisting only of the first fibers with the cleaning liquid, it was produced in the same manner as in Example 1 to obtain dry and wet wiping sheets.

[Evaluation of manufacturing costs]
In this evaluation, the manufacturing cost was evaluated according to the following criteria from the viewpoint of the manufacturing efficiency of the wiping sheet and the running cost of the manufacturing apparatus. The results are shown in Table 1 below.
A: Both production efficiency and running cost are good, and production cost is low.
○: Either production efficiency or running cost is good and is an acceptable production cost.
X: Production efficiency and running cost are not good, and production cost is difficult to be tolerated.

[Evaluation of collecting property of fine particle dirt]
Using 1st surface of the wiping sheet of the wet aspect of an Example and a comparative example, 0.6g per 1 tatami (1820mmx910mm) of 11 types of test powders prescribed | regulated to JISZ8901 as fine particle dirt was spread | dispersed. The flooring (Combit New Advance 101, manufactured by Wood One) was wiped for 6 tatami mats. The mass of the sheet before and after use of the sheet was measured, the dust collection rate (%) was calculated from the following formula, and the collection property of fine particle dirt was evaluated according to the following evaluation criteria. The results are shown in Table 1.

  Collection rate of fine particle dirt (%) = 100 × ((wiping sheet mass after use [g]) − (wiping sheet mass before use [g])) / 0.6 [g])

<Evaluation of collecting ability of fine particle dirt>
○: The collection rate of fine particle dirt is 50% or more, and the fine particle dirt can be collected effectively.
X: The collection rate of fine particle dirt is less than 50%, and it is difficult to collect fine particle dirt.

[Evaluation of tactile feel of sheet]
In this evaluation, the dry-type and wet-type wiping sheets in Examples and Comparative Examples were touched so that the side areas were pinched with fingers, and the touch feeling was evaluated according to the following criteria. The results are shown in Table 1 below.
<Dry type>
◯: The tactile sensation is good without the fibers clinging to the fingers.
X: The fiber clings to the finger and the tactile sensation is poor.
<Wet>
○: The fiber is not clinging to the finger, is not sticky, and has a good tactile sensation.
X: The fiber is clinging to the finger or feels sticky and the tactile sensation is poor.

[Evaluation of cleaning liquid discharge efficiency]
Applying a load of 0.16 kN / m ² to the wet wiping sheets of Examples and Comparative Examples, and using a flooring floor (Combit New Advance 101, manufactured by Wood One) at a wiping speed of 1 m / s, 20 tatami mats Wiping was performed continuously for ³ minutes (equivalent to 32.4 m ² ). From the amount of liquid discharged per tatami (g), how much was discharged at each wiping area relative to the initial amount of impregnation of the cleaning liquid was measured and evaluated according to the following criteria. The results are shown in Table 1 and FIG.

<Evaluation>
(Double-circle): The washing | cleaning liquid discharge | release rate at the time of wiping area 20 tatami is 75% or more.
○: The cleaning liquid release rate at the time when the wiping area is 20 tatamis is 60% or more and less than 75%.
X: The cleaning liquid release rate when the wiping area is 20 tatamis is less than 60%.

  As shown in Table 1, it can be seen that the wiping sheet of Example 1 is superior in the ability to collect fine particle dirt as compared with Comparative Example 2 that does not include the second fiber that is a fine fiber. .

  In addition, as shown in Table 1, the wiping sheet of the example has a lower manufacturing cost than the comparative example, and the sheet has excellent tactile sensation regardless of whether it is dry or wet. I understand.

  Further, as shown in Table 1 and FIG. 5, it can be seen that the wiping sheet of the example has higher cleaning liquid discharge efficiency than Comparative Example 2. The wiping sheet of Comparative Example 1 has a higher cleaning liquid release efficiency than the wiping sheet of the example, but the wet sheet feel is particularly poor, and the sheet feel and cleaning liquid release efficiency are compatible. You can see that they are not.

  Therefore, the wiping sheet of the present invention combines the good tactile sensation, the high collection performance of dirt due to the inclusion of small diameter fibers and large diameter fibers on the wiping surface, and the reduction of manufacturing costs. . Further, even when the wiping sheet of the present invention is in a wet mode, both the good tactile sensation of the sheet and the high discharge efficiency of the cleaning liquid are compatible.

DESCRIPTION OF SYMBOLS 1 Wiping sheet 1S Laminate 1P Fiber assembly 11 1st fiber 12 2nd fiber CA Central area SA Side area X Longitudinal direction Y Width direction Z Thickness direction MD Conveyance direction

Claims (4)

A first surface used as a wiping surface; and a second surface located on the opposite side of the first surface;
A central region located in the center of the width direction and extending in the longitudinal direction; and a pair of side regions adjacent to the central region and extending in the longitudinal direction;
The central region includes a first fiber and a second fiber having a smaller diameter than the first fiber, and the presence ratio of the second fiber is higher on the first surface than on the second surface. ,
Each said side area is a wiping sheet which contains a 1st fiber and does not contain a 2nd fiber except the case where it contains unavoidable.   The wiping sheet according to claim 1, wherein a ratio of the area of the central region to the area of the wiping sheet is 30% or more and 65% or less.   The wiping sheet according to claim 1 or 2, wherein the color of the first fiber is different from the color of the second fiber. Impregnated with cleaning liquid,
The wiping sheet according to any one of claims 1 to 3, wherein the cleaning liquid is carried at least on a fiber assembly located on the second surface side.

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