JP2019150534A - Wiping sheet - Google Patents

Abstract

To provide a wiping sheet having high oil contaminant-wiping property, and capable of suppressing spread of oil contaminant in a wiping object associated with wiping.SOLUTION: A wiping sheet is obtained by laminating a plurality of fiber layers. The wiping sheet is such that: a distance between fibers of fiber layers constituting a wiping surface of the wiping sheet is larger than that of the other fiber layers; the plurality of fiber layers have embossed recesses: and the embossed recesses of the fiber layers constituting the wiping surface are arranged toward the wiping surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wiping sheet.

  Various proposals have been made so far regarding wiping sheets for wiping off various articles. For example, Patent Document 1 describes a cleaning sheet including a wiping portion made of a liquid-permeable surface sheet and a liquid absorber that absorbs liquid wiped by the wiping portion. The cleaning sheet has a large number of protrusions that come into contact with the surface to be cleaned from the viewpoint of removing foam stains on the floor and suppressing foaming when wiping a wax agent or the like on the floor to improve the finish. It has in a surface sheet.

JP-A-9-131288

  The dirt wiped off by the wiping sheet includes oil dirt such as sebum and cooking oil. However, the conventional wiping sheet may spread on the surface to be wiped while absorbing oil stains, and it is difficult to completely wipe off.

  Therefore, the present invention relates to a wiping sheet that has a high oil stain wiping property and can suppress the spread of oil stains on a wiping object associated with wiping.

  The present invention is a wiping sheet in which a plurality of fiber layers are laminated, and the fiber layer constituting the wiping surface of the wiping sheet has a greater inter-fiber distance than other fiber layers, and the plurality of fibers All the layers have an embossed recess, and the embossed recess of the fiber layer constituting the wiping surface is provided toward the wiping surface.

  The wiping sheet of the present invention has a high wiping property for oil stains, and can suppress the spread of oil stains on a wiping object associated with wiping.

It is a partially expanded sectional view which shows typically the preferable form of the wiping sheet of this invention. (A) is explanatory drawing which shows typically the flow of the oil stain in sectional drawing of FIG. 1, (B) is the modification. It is a partially expanded sectional view which shows typically another preferable form of the wiping sheet of this invention. It is a partially expanded sectional view which shows typically another preferable form of the wiping sheet of this invention typically.

  Hereinafter, the wiping sheet of the present invention will be described with reference to the drawings based on preferred embodiments thereof.

In the present invention, unless otherwise specified, the surface of the wiping sheet that comes into contact with oil stains on the surface to be cleaned is referred to as the wiping surface or the lower surface, and the opposite surface is referred to as the upper surface. For each of the fiber layers on which the wiping sheet is laminated, a surface relatively closer to the wiping surface (lower surface) and the upper surface is referred to as a surface on the wiping surface (lower surface) side and a surface on the upper surface side, respectively. The normal direction of the wiping surface (lower surface) or upper surface of the wiping sheet is referred to as the thickness direction.
The term “wiping” as used herein refers to wiping off dirt by contacting an object to be cleaned. Various types of dirt are included, particularly oily dirt. The cleaning object in the wiping sheet of the present invention is not particularly limited, and various types of dirt can be mentioned.
Furthermore, the wiping sheet of the present invention may be either a dry type or a wet type, and may or may not contain a component that assists in wiping off dirt in addition to the constituent fibers. . When not included, a component that assists in wiping off dirt may be separately used during wiping.

  FIG. 1 shows a cross section in the sheet thickness direction of the wiping sheet 10 of the present embodiment. The wiping sheet 10 is formed by laminating a plurality of fiber layers. Specifically, two fiber layers 1 and 2 are laminated to form a sheet. The fiber layer 2 constitutes the wiping surface 10A of the wiping sheet 10, and the fiber layer 1 is laminated on the upper surface side opposite to the wiping surface of the fiber layer 2 (hereinafter referred to as the fiber layer 1 and the fiber layer 2). These are referred to as the first fiber layer 1 and the second fiber layer 2, respectively). That is, in the present embodiment, the wiping sheet 10 includes two layers, the second fiber layer 2 forms the wiping surface 10A, and the first fiber layer 1 forms the upper surface 10B. However, the number of fiber layers to be laminated is not limited to two layers in the present embodiment, and may be three or more layers. Here, the fiber layers to be laminated can be classified according to the average inter-fiber distance, the average fiber diameter, the fiber material, and the like.

  In the wiping sheet 10, the second fiber layer 2 constituting the wiping surface 10 </ b> A has a larger average interfiber distance than the first fiber layer 1 on the upper surface 10 </ b> B side. That is, the second fiber layer 2 on the wiping surface side has a larger space for oil absorption between the fibers than the first fiber layer 1 on the upper surface 10B side, and a capillary force difference between the two layers is generated. ing. The first fiber layer 1 and the second fiber layer 2 may be directly laminated as long as the capillary force difference is generated and oil stains can be effectively transferred from the second fiber layer 2 to the first fiber layer 1. Alternatively, a further fiber layer may be interposed between the two layers. In the latter case, for example, a further fiber layer is interposed between the second fiber layer 2 on the wiping surface 10A side and the first fiber layer 1 on the upper surface 10B side, so that the wiping sheet 10 is a fiber layer having different hydrophilicity / hydrophobicity. It is mentioned to have a laminated structure in which are alternately arranged. As long as the wiping sheet 10 has such a laminated structure, the further intervening fiber layer may be a single layer or a plurality of two or more layers. However, the first fiber layer 1 and the second fiber are used in order to minimize the remaining of oil stains on the second fiber layer 2 on the wiping surface side and transfer as much oil stains as possible to the first fiber layer 1 on the upper surface side as quickly as possible. The layer 2 is preferably laminated directly.

In addition, the wiping sheet 10 has an embossed recess in both the first fiber layer 1 and the second fiber layer 2 (hereinafter referred to as an embossed recess 31 in the first fiber layer 1 and an embossed recess 32 in the second fiber layer 2). ). Thereby, the fiber compaction part around the hollow of the embossing recessed parts 31 and 32 of each layer is arrange | positioned in the thickness direction, and the path | route of the transfer of the wiped oil from the 2nd fiber layer 2 to the 1st fiber layer 1 is made. In addition, it also serves as a route for transmitting the liquid drawability due to the difference in capillary force between the two layers due to the difference in the average interfiber distance to the wiping surface side.
In addition, the embossed recess 32 of the second fiber layer 2 constituting the wiping surface 10A is arranged toward the wiping surface 10A. Thereby, oil dirt is enclosed in the space of the embossed recess, and a capillary force is directly applied to the oil dirt of the object to be cleaned, so that the second fiber layer 2 having a larger average interfiber distance than the first fiber layer 1 is wide. I try to get into the space.

  The wiping sheet 10 quickly takes in oil stains on the object to be cleaned (increased oil absorption and wiping properties) due to the difference in the average inter-fiber distance and the configuration of the embossed recesses, and has liquid (oil) transferability between the fiber layers. improves. Therefore, the spread of oil stains can be suppressed in the contact range of the wiping sheet 10 on the surface to be cleaned. Hereinafter, this point will be described in more detail.

  The average interfiber distance can be determined by the following formula [I].

Here, π is the circumference ratio.
That is, the average interfiber distance can be calculated by measuring the basis weight, fiber diameter, sheet thickness, and specific gravity in each layer constituting the wiping sheet.

  Generally, the capillary pressure is known to follow the following formula [II].

Pc derived from the above equation is a value using summary statistics derived from measurement of the nonwoven fabric. Here, Pc is the capillary pressure (N / m ² ) of the fiber, γ _L is the surface tension (N / m) of the liquid, θ is the contact angle (rad) between the fiber and the liquid, and r is Capillary radius (m). Since the capillary radius corresponds to the interfiber distance, the average capillary pressure of the fiber can be obtained by using the value of the average interfiber distance for r.

  In order to measure Pc, it is necessary to measure the surface tension of the liquid, the fiber diameter, and the contact angle between the fiber and the liquid. 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 nonwoven fabric 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.

  As is clear from the above formula, the capillary pressure increases as the capillary radius (average fiber distance) decreases. In the present embodiment, the capillary pressure of the first fiber layer 1 is increased by reducing the average interfiber distance. When oil stains are wiped off using the wiping sheet 10 of the present embodiment, first, the oil stains are first absorbed by the second fiber layer 2 having a wiping surface. Thereafter, oil stains carried on the second fiber layer 2 are drawn into the first fiber layer 1 due to the difference in capillary pressure between the first fiber layer 1 and the second fiber layer 2. As a result, the oil stain once taken into the second fiber layer 2 is moved to the first fiber layer 1, and the second fiber layer 2 is always in a state where the oil stain can be wiped off.

  The difference between the average interfiber distance of the first fiber layer 1 and the average interfiber distance of the second fiber layer 2 is preferably 0.001 mm or more, more preferably 0.005 mm or more from the viewpoint of clarifying the capillary force difference. Preferably, 0.01 mm or more is more preferable. Further, the difference in the average inter-fiber distance is preferably 10 mm or less, more preferably 1 mm or less, and further preferably 0.5 mm or less, from the viewpoint of the stability of the liquid film formed between the fibers. Specifically, 0.001 mm or more and 10 mm or less is preferable, 0.005 mm or more and 1 mm or less is more preferable, and 0.01 mm or more and 0.5 mm or less is more preferable.

In addition to the above difference in average interfiber distance, as described above, both the first fiber layer 1 and the second fiber layer 2 have embossed recesses 31 and 32 that are consolidated by a recess wall by compression. And the embossed recessed part 32 of the 2nd fiber layer 2 is distribute | arranged toward 10 A of wiping surfaces.
As a result, in the wiping sheet 10, as described above, the oil dirt can be easily taken up on the wiping surface, and the oil dirt can easily move from the second fiber layer 2 to the first fiber layer 1 through the vicinity of the embossed recess. Become. As a result, the flow of oil stains in the thickness direction of the wiping sheet (flow of oil stains Q as shown by arrows A1 to A5 in FIGS. 2A and 2B) is completed, and the oil transferability and wiping properties of the wiping sheet are completed. Will improve. And the spread of oil dirt can be suppressed in the contact range to the surface to be cleaned by the wiping sheet 10.
In addition, the embossing recessed part 31 of the 1st fiber layer 1 and the embossing recessed part 32 of the 2nd fiber layer 2 are not restricted to the same position in the thickness direction. For example, as shown in FIG. 2B, the embossed recesses 31 and the embossed recesses 32 may be arranged in a range that can contribute to the oil transfer property and the wiping property.

  In any of the first fiber layer 1 and the second fiber layer 2, the embossed recesses 31 and 32 may be provided on one side or on both sides. Moreover, the embossing recessed part may penetrate the 1st fiber layer 1 or the 2nd fiber layer 2 in the thickness direction, and may form the hole.

  In the second fiber layer 2, as long as the embossed recess 32 is at least on the wiping surface 10A (lower surface side), it may exist other than the wiping surface 10A (lower surface side), for example, on the upper surface 10B side. Moreover, the embossing recessed part 32 may penetrate the 2nd fiber layer 2 in the thickness direction, and the 2nd fiber layer 2 may have an embossing recessed part on the lower surface side and the upper surface side (not shown).

In the first fiber layer 1, the embossed recess 31 is preferably on the wiping surface 10A (lower surface) side, as shown in FIG. The embossed recess on the lower surface side of the first fiber layer 1 improves the oil transfer property and wiping property of the wiping sheet.
On the other hand, in the 1st fiber layer 1, as shown in FIG. 3, an embossing recessed part may exist in the upper surface side on the opposite side to the wiping surface 10A side. Similarly, the embossed recess 31 on the upper surface 10B side in the first fiber layer 1 can also improve the oil transferability and wiping property of the wiping sheet.

  In the wiping sheet 10 of the present embodiment, it is also preferable that the embossed recess in the wiping surface of the second fiber layer 2 penetrates the second fiber layer 2 in the thickness direction and reaches the first fiber layer 1 ( (See FIG. 4). In this case, the first fiber layer 1 has an embossed recess on the lower surface side. In such an embodiment in which the first fiber layer 1 and the second fiber layer 2 are integrated to form a series of embossed recesses, when the oil stain is transferred from the second fiber layer 2 to the first fiber layer 1, The movement of the oil stain in the planar direction can be reduced, and the oil stain can be quickly moved in the thickness direction.

The embossed recess 32 of the second fiber layer 2 constituting the wiping surface is preferably 0.01 mm or more, and 0.05 mm or more in a plan view from the viewpoint of oil dirt uptake. Is more preferable and 0.1 mm or more is even more preferable. The embossed recess 32 is preferably 10 mm or less, more preferably 8 mm or less, and even more preferably 5 mm or less in plan view from the viewpoint of the number of embossed recesses. Specifically, 0.01 mm or more and 10 mm or less is preferable, 0.05 mm or more and 8 mm or less is more preferable, and 0.1 mm or more and 5 mm or less is more preferable.
Further, the depth of the embossed recess 32 of the second fiber layer 2 is preferably 0.01 mm or more, more preferably 0.05 mm or more, and further preferably 0.1 mm or more from the viewpoint of suppressing the spread of the wiped oil stain. In addition, the depth of the embossed recess 32 is preferably 10 mm or less, more preferably 8 mm or less, and even more preferably 5 mm or less from the viewpoint of workability. Specifically, 0.01 mm or more and 10 mm or less is preferable, 0.05 mm or more and 8 mm or less is more preferable, and 0.1 mm or more and 5 mm or less is more preferable.

  It is preferable that the embossed recess 31 of the first fiber layer 1 on the upper surface side has the same size and depth in plan view as the embossed recess 32 of the second fiber layer 2 described above.

(Measurement method of embossed recesses 32 and 31)
The size of the embossed recess 32 in a plan view can be measured using an optical microscope (for example, a digital microscope (trade name) manufactured by KEYENCE Corporation) in a plan view of the wiping surface. When the emboss 31 is exposed on the upper surface side of the first fiber layer 1, it can be measured by the same method as described above. When the embossed recess 31 is directed to the second fiber layer 2 side of the first fiber layer 1, the wiping sheet to be measured is cut out for each layer by a cutting means such as a razor blade, and measured by the same method as described above. be able to.
The depths of the embossed recesses 32 and 31 can be measured by the same method as described above by cutting a section in the thickness direction of the wiping sheet to be measured by a cutting means such as a razor blade.

The embossed recess can be formed by various commonly used methods. For example, a heat embossing process, an ultrasonic embossing process, etc. are mentioned.
In the present embodiment, the first fiber layer 1 and the second fiber layer 2 may be laminated after being separately embossed, or the first fiber layer 1 and the second fiber layer 2 may be laminated. You may emboss the sheet. In particular, in order to form a series of embossed recesses that penetrate through the second fiber layer 2 and reach the first fiber layer 1, the embossing process is performed after the first fiber layer 1 and the second fiber layer 2 are laminated. It is preferable.

The fibers constituting the first fiber layer 1 and the second fiber layer 2 used in this embodiment are not particularly limited as long as the oil transfer property and wiping property of the wiping sheet of this embodiment are not impaired. For example, polyester, polyamide, polyolefin, cellulose fiber, and fibers made from various metals, glass, and minerals are typical. Among these, polyester, polyamide, polyolefin, and cellulose fiber are preferable. Moreover, these mixed fibers, for example, polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate, etc. are also mentioned.
Among the fibers, polyethylene terephthalate, polypropylene, acrylic resin, nylons, and cellulose fibers are more preferable. The acrylic resin (particularly acrylic acid) preferably has a repeating unit obtained from its ester, methacrylic acid or its ester.

  The wiping sheet of the present invention can be used without particular limitation for various types of surfaces to be cleaned as long as it involves wiping off oil stains. For example, it can be used for wiping furniture such as buildings such as floors and walls, cupboards, window glass, mirrors, doors, doorknobs, furniture such as rugs, carpets, and desks, kitchens, and toilets. It can also be used for cleaning wipers, and can also be used for cleaning the face and body, as well as sanitary goods, civil engineering, and packaging.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to this.

(Production example of fiber layer)
Fiber layers A and B used in Examples and Comparative Examples described below were produced as follows.

(Fiber layer A)
Using a polypropylene resin pellet (Moplen HP461Y (trade name), manufactured by Lyondell Basell) having a melt flow rate (MFR) of 1300 g / 10 min (230 ° C., 2.16 kg), a die air flow rate of 300 Nm ³ / hr, hot air wind speed of 79.8 m / S and a conveyor speed of 5 m / mim, a sheet-like fiber layer A was produced by the melt blown method.

(Fiber layer B)
A sheet-like fiber layer B was produced in the same manner as the fiber layer A except that the die air flow rate was 100 Nm ³ / hr and the hot air flow speed was 26.6 m / s.

The fiber diameters, sheet thicknesses, and basis weights of the obtained fiber layers A and B were as follows.
(1) Fiber diameter Fiber layer A: 4.25 μm Fiber layer B: 14.11 μm
For fiber layer A, JSM-6510 (trade name, manufactured by JEOL Ltd.) was used as a scanning electron microscope (SEM), and for fiber layer B, VHX-1000 (trade name, Keyence Corporation) was used as an optical microscope. ).
(2) Sheet thickness Fiber layer A: 437.27 μm Fiber layer B: 526.93 μm
The thickness was measured using a micrometer SMD-565 (trade name, manufactured by TECLOCK).
(3) Basis weight Fiber layer A: 48.24 g / m ² Fiber layer B: 46.37 g / m ²
In addition, it measured using balance GH-202 (brand name, A & D Co., Ltd. product).
(4) Specific gravity The specific gravity was 0.886 g / ml as measured from a polypropylene resin pellet as a raw material with a pycnometer.

(5) Average interfiber distance Based on the measured values of the above (1) to (4), the average interfiber distance of each of the fiber layers A and B was calculated using the above-mentioned formula [I].
Fiber layer A: 10.68 μm Fiber layer B: 39.68 μm
That is, the fiber layer B has a greater interfiber distance than the fiber layer A.

  Each Example and each Comparative Example produced each wiping sheet sample as follows using the fiber layers A and B.

Example 1
Embossing was performed on one side of each of the fiber layer A and the fiber layer B using an embossing mold having a cylinder diameter of 76 mm, a mold width of 205 mm, and an area ratio of 22.5%. At this time, the processing speed was 3 m / min, the pressure was 2.48 kg / cm ² , and the linear pressure was 0.005488 MPa.
After the embossing treatment, the fiber layer B was used as a fiber layer constituting the wiping surface, and the fiber layer A was laminated thereon. At that time, the embossed concave portion of the fiber layer B and the embossed concave portion of the fiber layer A were arranged so as to face the wiping surface side. Moreover, joining of the fiber layer B and the fiber layer A was performed by heat sealing | fusion. Thus, the wiping sheet sample of Example 1 was produced.

(Example 2)
When laminating the fiber layer B and the fiber layer A, the wiping sheet sample of Example 2 was prepared in the same manner as in Example 1 except that the embossed recesses of the fiber layer A were disposed on the upper surface side. Produced.

(Example 3)
Prior to embossing, the fiber layer B and the fiber layer A were laminated by heat fusion and integrated.
The wiping surface side of the integrated sheet (the surface on which the fiber layer B is disposed) was embossed under the same conditions as in Example 1 to produce a wiping sheet sample of Example 3. In the wiping sheet sample of Example 3, the embossed recess penetrated the fiber layer B and reached the fiber layer A.

(Comparative Example 1)
Two fiber layers A not subjected to the embossing treatment were laminated to prepare a wiping sheet sample of Comparative Example 1.

(Comparative Example 2)
Two fiber layers B not subjected to embossing were laminated to prepare a wiping sheet sample of Comparative Example 2.

(Comparative Example 3)
A wiping sheet sample of Comparative Example 3 was produced in the same manner as in Example 1 except that the fiber layer B and the fiber layer A were not embossed.

(Comparative Example 4)
A wiping sheet sample of Comparative Example 4 was produced in the same manner as in Example 1 except that two fiber layers A were laminated instead of laminating the fiber layer B and the fiber layer A. In this sample, the embossed recesses of the two laminated fiber layers A were all arranged toward the wiping surface.

(Comparative Example 5)
A wiping sheet sample of Comparative Example 5 was produced in the same manner as in Example 1 except that two fiber layers B were laminated instead of laminating the fiber layer B and the fiber layer A. In this sample, the embossed recesses of the two laminated fiber layers B were all arranged toward the wiping surface side.

(Comparative Example 6)
When laminating the fiber layer B and the fiber layer A, the embossed concave portion of the fiber layer B is disposed and laminated toward the upper surface side opposite to the wiping surface, in the same manner as in Example 1, A wiping sheet sample of Comparative Example 6 was prepared.

(Comparative Example 7)
When laminating the fiber layer B and the fiber layer A, the same procedure as in Example 1 was performed except that the embossed recesses of the fiber layer B and the embossed recesses of the fiber layer A were both arranged and laminated toward the upper surface side. Thus, a wiping sheet sample of Comparative Example 7 was produced.

(Comparative Example 8)
A wiping sheet sample of Comparative Example 8 was produced in the same manner as in Example 1 except that the fiber layer B was not embossed.

(Comparative Example 9)
A wiping sheet sample of Comparative Example 9 was produced in the same manner as in Example 1 except that the fiber layer A was not embossed.

(Comparative Example 10)
Except that the embossing treatment was performed on the upper surface side (surface on which the fiber layer A is disposed) instead of the wiping surface side (surface on which the fiber layer B is disposed) of the integrated sheet, In the same manner as in Example 3, a wiping sheet sample of Comparative Example 10 was produced. In the wiping sheet sample of Comparative Example 10, the embossed recess penetrated the fiber layer A and reached the fiber layer B.

(test)
The following tests (1) to (3) were performed on each of the above samples in an environment where the room temperature was 20 ° C. and the humidity was 65%.

(1) Oil retention (oil absorption, oil migration between fiber layers)
The sample was cut into a size of 5 cm square in advance, and the fiber layer A and the fiber layer B were weighed separately.
As a sample of oil stains, 1 μL (about 30 mg) of colored oleic acid droplets were dropped on a composite flow long flooring, and a sample of 5 cm square (laminated body of fiber layer B and fiber layer A) was wiped on it. Covered from the fiber layer B side). A 550 g weight was placed on the sample and allowed to stand for 5 seconds, and then the fiber layer A and the fiber layer B were separately weighed separately.
The mass of each fiber layer of the sample before and after absorbing the oleic acid droplets was compared, and the amount of oil retained in each fiber layer of the sample was evaluated. The reason why oleic acid is used as the oil stain is that it is a general component of sebum stain in a general living environment.

(2) Wiping property A sample was cut into a size of 5 cm square.
As a sample of oil stain, 1 μL (about 30 mg) of a dyed oleic acid droplet was dropped on a composite flow long flooring, and a sample of 5 cm square was put thereon. While placing a 550 g weight on the sample, perform a wiping operation for 5 seconds in a circular pattern to determine whether or not the oleic acid droplets were wiped off from a white fluorescent lamp 190 cm away from the composite flow long flooring. The degree of light reflection was confirmed by visual observation and evaluated according to the following criteria.
4: Oleic acid droplets can be wiped off within 3 seconds to the extent that reflection cannot be confirmed (to the extent that the oil cannot be visually confirmed).
3: The oleic acid droplets can be wiped off to such an extent that reflection cannot be confirmed (to the extent that the oil cannot be visually confirmed), but it takes more than 3 seconds.
2: Oil shine remains and the oleic acid droplets cannot be completely wiped off.
1: There are many oil shines and many oleic acid droplets remain.

(3) Liquid stretch evaluation A sample was cut into a size of 5 cm square.
As an oil stain sample, 3 mg of colored oleic acid was dropped onto the composite flow long flooring. A 5 cm square sample and a 500 g weight were placed thereon and left for 3 seconds. Thereafter, the sample was moved together with the weight at a speed of 8 cm / s in one direction for 40 cm (5 seconds), and the sample and the weight were immediately removed from the composite flow long flooring. Next, the removed sample and weight are placed on a composite flow long flooring to which oleic acid is not dripped, and moved at the same speed for 40 cm (5 seconds). The sample and weight are immediately removed from the composite flow long flooring. Removed. Such wiping work was performed a total of four times (total movement distance: 160 cm), and the distance that oleic acid was extended was measured.
The measurement was performed three times for each sample, and the liquid elongation was evaluated by the average value of the three measurement values.
The smaller the measured value, the better the wiping property.

  The results are shown in Table 1. In addition, "-" in the table indicates that the embossed recess position item does not have embossing, and the oil retention amount evaluation item indicates that the first fiber layer 1 and the second fiber layer 2 are fused. It shows that it is difficult to measure.

As is clear from Table 1, in Comparative Examples 1 and 2 where there is no difference in the inter-fiber distance between the fiber layers, the oil transfer from the fiber layer on the wiping surface side to the fiber layer on the upper surface side is poor, and the oil on the floor surface The wiping property was so bad that there was a lot of shine. Therefore, it was 160 cm which was the worst in the liquid spreading of the floor surface by wiping. Further, Comparative Examples 3, 8 and 9 which do not satisfy the requirement of providing embossed recesses in both layers, Comparative Examples 4 and 5 which have embossed recesses but no difference in fiber distance between fiber layers, In Comparative Examples 6, 7 and 10, which are not provided on the wiping surface (lower surface) side of the two-fiber layer 2, the oil transfer property to the fiber layer on the upper surface side was not sufficient, and the wiping property was inferior. Furthermore, it was not able to be suppressed within 40 cm in the liquid stretching evaluation (it cannot be wiped off by one wiping operation).
On the other hand, in Examples 1 to 3 which are wiping sheets of the present invention, the fiber layer on the upper surface side absorbs oleic acid three times or more more than the fiber layer on the wiping surface side, and the fiber layer on the upper surface side. The oil transferability to was high. In addition, in Examples 1 to 3, oleic acid droplets could be quickly wiped off within 3 seconds, indicating high wiping properties. Furthermore, in Examples 1 to 3, the liquid stretch evaluation was 6 cm or less, and the spread of oil stains due to wiping was extremely small, and the oil stains were hardly left on the cleaning surface.

DESCRIPTION OF SYMBOLS 1 1st fiber layer 2 2nd fiber layer 10 Wiping sheet | seat 10A Wiping surface 10B Upper surface 31, 32 Embossing recessed part

Claims (5)

A wiping sheet in which a plurality of fiber layers are laminated,
The fiber layer constituting the wiping surface of the wiping sheet has a larger inter-fiber distance than other fiber layers,
Each of the plurality of fiber layers has an embossed recess, and the embossed recess of the fiber layer constituting the wiping surface is arranged toward the wiping surface.   The wiping sheet according to claim 1, wherein the other fiber layer has the embossed recess on a surface on a wiping surface side.   3. The wiping sheet according to claim 1, wherein an embossed recess of a fiber layer constituting the wiping surface is disposed through the other fiber layer.   The said other fiber layer is a wiping sheet of any one of Claims 1-3 which has the said embossing recessed part in the surface on the opposite side to the wiping surface side.   The wiping sheet according to any one of claims 1 to 4, wherein the embossed recess of the fiber layer constituting the wiping surface has a size in a plan view of 0.01 mm or more and 10 mm or less.

Images