JP7724078B2 - Cleaning sheets - Google Patents

Description

The present invention relates to a cleaning sheet.

Conventionally, cleaning sheets have been known in which an aqueous disinfectant is impregnated into a base sheet capable of retaining liquid, the aqueous disinfectant containing a quaternary ammonium salt surfactant as component (A), potassium hydroxide as component (B), an aminocarboxylic acid chelating agent as component (C), and water as component (D), the pH of the aqueous disinfectant impregnated into the base sheet being 10.5 or more and 13.5 or less, and the base sheet containing at least one fiber selected from recycled fibers, synthetic fibers, and natural fibers (see, for example, Patent Document 1).

Patent No. 6665151

However, in the case of the cleaning sheet of Patent Document 1, although it is preferable that the fibers constituting the base sheet contain recycled fibers, no consideration has been given to the orientation of the fibers constituting the base sheet.
Therefore, the present inventors have studied the orientation of the fibers that make up the sheet, and have developed a cleaning sheet that is easy to use.

The object of the present invention is to provide a cleaning sheet that is easy to use.

In order to solve the above problems, the invention described in claim 1 is
A cleaning sheet in which a sheet material capable of retaining liquid is impregnated with a chemical solution,
The basis weight of the sheet material is 35 gsm or more and 45 gsm or less,
A herringbone pattern is formed on the entire surface of the sheet material in a manner that fibers cross obliquely due to regions of different fiber densities,
the chemical solution contains polyoxyethylene alkyl ether as a surfactant, an organic acid, and a salt of an organic acid, and the chemical solution exhibits a neutral pH of 6 or more and 7 or less due to the buffering action of the organic acid and the salt of the organic acid ;
The cleaning sheets are stored in a storage container in a rolled state with multiple sheets connected via perforations, and are used by being pulled out one by one from an ejection hole in an ejection part provided in the storage container,
the oblique lines of the herringbone pattern formed on the cleaning sheet are arranged to form an acute angle with respect to the direction in which the cleaning sheet is pulled out,
When the cleaning sheet is pulled out from the removal hole, resistance is applied from the hole wall of the removal hole, and the cleaning sheet to be pulled out and used is cut off along the perforations, and the end of the succeeding cleaning sheet is held in a state where it protrudes from the removal hole .

The present invention provides an easy-to-use cleaning sheet.

1 is a perspective view showing a sanitary tissue paper storage container according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 10 is a cross-sectional view showing a state in which a cleaning sheet is inserted through the removal portion of the sanitary tissue paper storage container. FIG. FIG. 1 is a plan view showing a cleaning sheet according to an embodiment of the present invention. FIG. 2 is a perspective view showing the removal portion of the sanitary tissue paper storage container. FIG. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7 for explaining the shape of the chamfered portion. FIG. 10A and 10B are diagrams for explaining the shape of a chamfered portion. 10 is a bottom view of the ejection portion showing a modified example of the ejection hole. FIG.

Hereinafter, embodiments of the cleaning sheet according to the present invention will be described in detail with reference to the drawings. However, although the embodiments described below are subject to various limitations that are technically preferable for carrying out the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples.
In the following description, the front-to-back, left-to-right, and up-to-down directions, as well as the X-axis, Y-axis, and Z-axis, are defined as shown in Figure 1. That is, in a sanitary tissue paper storage container 100 that stores cleaning sheets known as sanitary tissue paper, the side from which the cleaning sheets are removed is defined as the top, the opposite side as the bottom, the near side in a plan view of the sanitary tissue paper storage container 100 as the front, the opposite side as the back, the right-hand side when the front of the container is viewed from the front, and the left-hand side when the front of the container is viewed from the front, and the axis along the front-to-back direction is defined as the X-axis, the axis along the left-to-right direction is defined as the Y-axis, and the axis along the up-to-down direction is defined as the Z-axis.

<Configuration of the embodiment>
(Overall structure)
As shown in Figures 1 to 3, the sanitary tissue paper storage container 100 is configured to include a container body 1 that stores cleaning sheets P, which are sanitary tissue paper, inside, a lid body 2 that can be removably attached to the container body 1, and a removal section 3 that can be removably attached to the lid body 2.
The lid body 2 is configured to be detachable from the container body 1, so that with the lid body 2 removed from the container body 1, the cleaning sheet P can be stored inside the container body 1 or taken out from the inside.

(cleaning sheet)
The cleaning sheet P is, for example, a roll of wet paper such as a wet sheet or wet tissue wound into a roll.
3, the cleaning sheet P is stored in the container body 1 in a rolled state with its axis aligned in the vertical direction. In other words, the container body 1 stores the cleaning sheet P in such a way that its axis is substantially perpendicular to the bottom 1b that forms the bottom surface of the container body 1.
The cleaning sheet P stored in the container body 1 is pulled out from the center of the roll and taken out through the take-out section 3.
The cleaning sheet P has perforations P1 at regular intervals in the length direction, and the cleaning sheet P is cut off along the perforations P1 for use by the user.

The cleaning sheet P is a sheet material capable of retaining liquid that is impregnated with a chemical solution, and is a multi-purpose cleaner that can be used to wipe off stains from tables, floors, etc. The cleaning sheet P may also be used as a kitchen cleaner or toilet cleaner.
The sheet material of the cleaning sheet P is preferably a nonwoven fabric manufactured using a known technique such as spunlace, air-through, air-laid, point bond, spun bond, or needle punch using a predetermined fiber as the fiber material.
Examples of the predetermined fiber include cellulose fibers such as rayon, lyocell, Tencel, and cotton, polyolefin fibers such as polyethylene, polypropylene, and polyvinyl alcohol, polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, and polyamide fibers such as nylon. These may be used alone or in combination of two or more.

In particular, as shown in FIG. 4, this sheet material (cleaning sheet P) has a herringbone pattern formed in areas where the fiber density is different and the fibers cross diagonally.
Specifically, the sheet material (cleaning sheet P) has a herringbone pattern formed by high fiber density regions and low fiber density regions with a lower fiber density than the high fiber density regions, with the fibers crossing diagonally, and for example, linear convex portions made up of the high fiber density regions and linear concave portions made up of the low fiber density regions are formed.
That is, the surface of the sheet material (cleaning sheet P) is formed with a herringbone pattern of linear convex portions made up of high fiber density regions and linear concave portions made up of low fiber density regions.
The cleaning sheet P has an uneven herringbone pattern in which fibers cross diagonally, making it easy to scrape off dirt.
The unevenness formed on the cleaning sheet P may be a herringbone pattern unevenness consisting of linear recesses made up of high fiber density regions and linear protrusions made up of low fiber density regions.

The sheet material for the cleaning sheet P preferably has a basis weight of 35 gsm to 45 gsm, and a size of 100 mm to 200 mm in the MD direction (the direction in which the paper travels on the paper machine) and 100 mm to 200 mm in the CD direction (the direction perpendicular to the direction in which the paper travels on the paper machine). The basis weight refers to the basis weight measured in accordance with JIS P 8124:2011.
The sheet material of the cleaning sheet P of this embodiment has a size of 195 mm in the MD direction and 140 mm in the CD direction when cut along the perforations P1.
That is, the cleaning sheets P shown in FIG. 4 are connected vertically in the drawing via perforations P1, and a plurality of connected long cleaning sheets P are wound into a roll.

If the basis weight of the sheet material of the cleaning sheet P is 35 gsm or more and 45 gsm or less, it can be used to effectively wipe or scrape off dirt, and can be easily pulled out from the removal section 3 (removal hole 33 described later) of the sanitary tissue paper storage container 100.
Furthermore, in the case of the cleaning sheet P of this embodiment, the diagonal lines of the herringbone pattern are arranged at an acute angle to the direction in which the cleaning sheet P is pulled out (up and down in Figure 4), which makes the frictional resistance between the removal hole 33 of the removal part 3 relatively small and makes it easier to pull out the cleaning sheet P, making it possible to more conveniently pull out the cleaning sheet P from the removal part 3 (removal hole 33) of the sanitary tissue paper storage container 100.

The chemical liquid impregnated into the cleaning sheet P (sheet material) can be any liquid depending on the intended use of the cleaning sheet P, but it is preferable to use one containing, for example, purified water, a preservative, a pH adjuster, a surfactant, etc.

The chemical solution of this embodiment contains an organic acid and a salt of the organic acid, and the buffering effect of this makes the chemical solution neutral, with a pH of 6 or more and a pH of 7 or less.
Here, citric acid was used as the organic acid, and sodium citrate was used as the salt of the organic acid.
If the chemical solution impregnated in the cleaning sheet P (sheet material) is neutral, it can cause less damage to the object to be cleaned than alkaline or acidic chemical solutions, so the versatility of the cleaning sheet P is increased and it can be used to clean a variety of objects.

The chemical solution of this embodiment also contains polyoxyethylene alkyl ether as a surfactant.
The present inventors have found that polyoxyethylene alkyl ether is suitable as a surfactant for a neutral chemical solution.

(Container body)
The container body 1 is a cylindrical container with a bottom, and has a bottom 1b on the lower surface and an opening 1a on the upper surface. The cleaning sheet P is stored inside the container body 1 through this opening 1a.
As shown in FIGS. 2 and 3, a male screw portion 11 is provided on the outer peripheral surface of the container body 1 in the vicinity of the opening 1a, along the circumferential direction.
The container body 1 is made of, for example, PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), ABS resin, or the like.
The container body 1 is formed in a cylindrical shape with a circular shape having a diameter of 50 mm to 200 mm in a plan view, a Z-axis direction (height) of 45 mm to 200 mm, and thicknesses of 0.5 mm to 10 mm on each side.

(lid)
As shown in FIGS. 1 to 3, the lid 2 is composed of a lid main body 21 and a small lid 22 .

(lid body)
The lid body main body 21 is formed from, for example, PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), ABS resin, etc., and has a cylindrical shape with an open bottom surface, and is provided with a top surface portion 21a, a side surface portion 21b, a recess 21c formed in a concave shape facing downward on the inner side of the top surface portion 21a when viewed in plan, a hole portion 21d, and a main body side wall portion 21e that is cylindrically erected within the recess 21c to surround the hole portion 21d.
The lid body 21 is circular in plan view with a diameter of 50 mm to 200 mm, and is formed in a cylindrical shape with a Z-axis direction (height) of 15 mm to 50 mm and thicknesses of 0.5 mm to 10 mm on each side.

Furthermore, a female thread portion 211 that screws into the male thread portion 11 of the container body 1 is provided on the inner peripheral surface of the lower end of the side portion 21b. As a result, as shown in Figures 2 and 3, the container body 1 and the lid body 2 have a detachable connection structure via the male thread portion 11 and the female thread portion 211, making it possible to remove the lid body 2 from the container body 1.

(Recessed portion of the lid)
The recess 21c is formed so that its shape in plan view is approximately the same as that of the small cover 22 when closed, allowing the small cover 22 to be fitted in. The front end of the recess 21c is larger than the small cover 22 in plan view, and a small gap remains even when the small cover 22 is fitted in. This makes it possible to use the gap to hook a finger on the small cover 22.

(hole)
The hole 21d is a circular hole formed in the plan view at approximately the center of the lid body 21, and leads to the inside of the sanitary tissue paper storage container 100. When viewed in the plan view, the hole 21d is formed slightly smaller than the removal section 3, and the removal section 3 is fixed to the hole 21d as described below.

(Main body side wall)
The main body side wall 21e is formed in a cylindrical shape within the recess 21c, extending upward to surround the hole 21d. The main body side wall 21e is formed so that its outer diameter is the same as or slightly smaller than the inner diameter of the small cover side wall 22a of the small cover 22.

(small lid)
The small lid 22 is formed from, for example, PE (polyethylene), PP (polypropylene), PET (polyethylene terephthalate), ABS resin, etc., and its base end is connected to the lid body main body 21 and has a small lid side wall portion 22a that protrudes from the underside when closed.
The base end of the small lid 22 where it is connected to the lid body 21 functions as a rotation axis 22 b of the small lid 22 .
The small lid 22 is formed so that its shape in a plan view when closed substantially matches that of the recess 21c, and so that it can be fitted into the recess 21c when closed.

(Small lid side wall)
The small lid side wall 22a is formed in a cylindrical shape that extends downward when the small lid 22 is closed. The small lid side wall 22a is formed so that its inner diameter is the same as or slightly larger than the outer diameter of the main body side wall 21e. The small lid side wall 22a is configured to contact the upper surface of the recess 21c when the small lid 22 is closed. This allows the small lid side wall 22a and the main body side wall 21e to fit together when the small lid 22 is closed, maintaining airtightness of the space surrounded by the small lid side wall 22a and the main body side wall 21e, and thus the interior of the sanitary tissue paper storage container 100, which is connected to this space via the hole 21d.

In this embodiment, the airtightness of the inside of the sanitary tissue paper storage container 100 is maintained by fitting the main body side wall portion 21e and the small lid side wall portion 22a together, but a different configuration from the above is also possible as long as the airtightness of the inside of the sanitary tissue paper storage container 100 can be maintained.
Furthermore, if the cleaning sheets P to be stored are not soaked in a chemical solution or the like and there is no need to prevent them from drying out, the storage container may be configured without any airtight means.

(Ejecting part)
5 and 6, the removal section 3 is an elastically deformable member formed in a generally cylindrical shape that is circular in a plan view, and can be formed by, for example, injection molding. Note that Fig. 6 is a bottom view of the removal section 3, showing the removal section 3 of Fig. 5 as viewed from below.
The removal portion 3 is a member for removing the cleaning sheet P stored inside the container body 1 .
Specifically, the removal portion 3 comprises a recess 31 having an inner bottom surface 3a formed in the center when viewed from above, a constricted portion 32 formed on the side, an removal hole 33 formed approximately in the center when viewed from above of the recess 31 (inner bottom surface 3a), and chamfered portions (first chamfered portion 341, second chamfered portion 342) formed by chamfering the peripheral portion of the removal hole 33 on the lower surface 3b.
The take-out portion 3 has a circular shape slightly larger than the hole portion 21d and having a diameter equal to or greater than one-tenth and equal to or less than one-third of the diameter of the lid body 21 in a plan view.
The thickness R1 (see FIG. 7) in the Z-axis direction below the constricted portion 32 of the take-out portion 3 (the dimension between the inner bottom surface 3a and the lower surface 3b) is set to 1.0 mm to 5.0 mm, preferably 1.5 mm to 3.0 mm. If the thickness in the Z-axis direction is too thin, the sheet will come out in a continuous state without being cut, and if it is too thick, the sheet will break before the next sheet comes out.

(Recessed portion of the take-out section)
The recess 31 is formed on the upper surface of the extraction portion 3 so as to be concave downward in a circular shape in top view, leaving a peripheral edge portion, and the depth of the recess 31 (depth in the Z-axis direction) is formed to be 2 mm to 10 mm.
The recess 31 is formed so that its inner bottom surface 3a is flat.

(Constricted part)
The constricted portion 32 is formed in the shape of a radially recessed groove that runs around the circumferential direction of the approximately vertically central portion of the side surface of the extraction portion 3 and has a depth in plan view that is between one-twentieth and one-tenth of the diameter of the extraction portion 3. The dimension of this constricted portion 32 in the Z-axis direction is formed to be 0.5 mm to 3.0 mm.
As described above, the removal portion 3 is formed slightly larger than the hole portion 21d when viewed in a plane, and therefore, by fitting the edge of the hole portion 21d into this constricted portion 32, it is possible to fix the removal portion 3 to the lid body main body 21.

(Ejection hole)
The removal hole 33 is a hole for removing the cleaning sheet P stored inside the container body 1 .
The removal hole 33 holds the cleaning sheet P inserted from the lower surface 3b side with its leading end protruding from the upper surface of the removal portion 3 (the inner bottom surface 3a of the recess 31).
When the tip of the cleaning sheet P protrudes from the top surface of the removal section 3, the protrusion amount is 10 mm to 30 mm, preferably 13 mm to 20 mm. This protrusion amount makes it easy for a typical user to pick up the sheet with their fingers and to easily remove it.

The extraction hole 33 typically has a small hole 33a that is substantially circular in plan view and a plurality of slits 33b that are formed radially from the small hole 33a. Note that the term "substantially circular" as used herein includes not only a perfect circle, but also an ellipse, a distorted circle, etc.
In this embodiment, four slits 33b are provided around the small hole 33a, as shown in Figures 5 and 6. The slits 33b are provided at 90° intervals around the small hole 33a.
The diameter of the small holes 33a is set to 1.0 mm to 5.0 mm, preferably 2.0 mm to 4.0 mm. If the diameter of the small holes 33a is too large, the next sheet will not be held and will fall down, and if the diameter is too small, a lot of force will be required to remove it.
The length R2 of the slit 33b (see FIG. 7) is set to 2 mm to 10 mm.

This removal hole 33 applies resistance to the pulled-out cleaning sheet P, so that the cleaning sheet P to be used can be cut off along the perforation P1, and the end of the succeeding cleaning sheet P can be held in a state where an appropriate amount of the end protrudes from the removal hole 33.
In this way, with the removal hole 33 consisting of a small hole 33a and multiple slits 33b, it is possible to achieve both the reliability of holding the cleaning sheet P in the removal hole 33 and the ease of pulling out the cleaning sheet P held in the removal hole 33.
5 and 6 illustrate the case where four slits 33b are formed, but the shape of the extraction hole 33 is not limited to this, and any number of slits 33b may be formed as long as the above function can be achieved. In other words, the extraction hole 33 may be a combination of small circular or elliptical holes 33a and any number of slits 33b.

(chamfered part)
The chamfered portions (first chamfered portion 341, second chamfered portion 342) are areas where the corner formed by the lower surface 3b of the extraction portion 3 and the hole wall 33h of the extraction hole 33 is chamfered, as shown in Figures 6 and 7.
Specifically, the chamfered portions (first chamfered portion 341, second chamfered portion 342) are flat chamfered portions formed by chamfering the edge of the hole wall 33h of the extraction hole 33 with an inclined plane on the lower surface 3b of the extraction portion 3, and by forming these chamfered portions, the extraction hole 33 has a shape in which the opening area on its lower end side is larger than the opening area on its upper end side.
Here, a first chamfered portion 341 is provided by chamfering the corner formed by the hole wall 33h of the slit 33b and the lower surface 3b of the removal portion 3, and a second chamfered portion 342 is provided by chamfering the corner formed by the hole wall 33h of the small hole 33a and the lower surface 3b of the removal portion 3.
As shown in FIG. 8, the sizes of the chamfered portions (first chamfered portion 341, second chamfered portion 342) are preferably set so that the length L1 from the hole wall 33h of the extraction hole 33 in the width direction (direction along the XY plane) of the extraction hole 33 is within the range of 0.1 mm to 0.5 mm, and the length L2 from the lower end of the extraction hole 33 in the height direction (direction along the Z-axis direction) is within the range of 0.1 mm to 0.5 mm.
By providing such chamfered portions (first chamfered portion 341, second chamfered portion 342) on the lower edge of the removal hole 33, the cleaning sheet P held in the removal hole 33 can be pulled out in an appropriate manner.

Here, the case where the chamfered portions (first chamfered portion 341, second chamfered portion 342) are formed by chamfering a flat surface has been illustrated and explained. However, the chamfered portions may also be curved chamfered portions, as shown in FIG. 9, in which the corner formed by the lower surface 3b of the extraction portion 3 and the hole wall 33h of the extraction hole 33 is chamfered to form a convex curved surface.
10, a chamfered portion may not be formed in the small hole 33a portion of the extraction hole 33, and a first chamfered portion 341 may be formed only in the slit 33b portion of the extraction hole 33.

In the above-mentioned removal section 3, the force required to pull out the cleaning sheet P is measured five times using a digital force gauge (manufactured by IMADA: model number DS2-200N) and the average value is defined as the resistance value. In this case, the resistance value is preferably in the range of 5N to 12N, and more preferably in the range of 7N to 9N.
Furthermore, when a cleaning sheet P (for example, a roll of 80 sheets connected together with 79 perforations) is pulled out, the allowable range for the number of times (number of times of connection) that the subsequent cleaning sheets P come out without breaking the perforations is within 10 times, and preferably within 5 times.

<Operation of the embodiment>
The cleaning sheet P described above has a herringbone pattern formed in a manner that fibers cross obliquely in areas with different fiber densities, and the surface of the cleaning sheet P has unevenness of the herringbone pattern, making it easy to scrape off dirt.

<Effects of the embodiment>
According to this embodiment, in a cleaning sheet P in which a sheet material capable of retaining liquid is impregnated with a chemical solution, a herringbone pattern is formed in the sheet material in such a way that the fibers cross diagonally in areas of different fiber densities.
The cleaning sheet P of this embodiment has such a structure and is easy to scrape off dirt, so it is easy to use and can be suitably used as a cleaning sheet for wiping off dirt.

Furthermore, according to this embodiment, the chemical solution impregnated into the cleaning sheet P (sheet material) contains an organic acid and a salt of the organic acid, and the buffering action of this makes the chemical solution neutral, with a pH of 6 or more and a pH of 7 or less.
If the chemical solution impregnated in the cleaning sheet P is neutral, it can cause less damage to the object to be cleaned than alkaline or acidic chemical solutions, so the versatility of the cleaning sheet P is increased and it can be used to clean various objects.

Furthermore, according to this embodiment, the chemical solution impregnated into the cleaning sheet P (sheet material) contains polyoxyethylene alkyl ether as a surfactant.
Polyoxyethylene alkyl ether is a highly versatile surfactant, so a cleaning sheet P impregnated with a chemical solution containing polyoxyethylene alkyl ether can be used to clean a variety of objects.

According to this embodiment, the basis weight of the sheet material of the cleaning sheet P is 35 gsm or more and 45 gsm or less.
If the basis weight of the sheet material of the cleaning sheet P is 35 gsm or more and 45 gsm or less, it can be used to effectively wipe or scrape off dirt, and can be easily pulled out from the removal section 3 (removal hole 33) of the sanitary tissue paper storage container 100.

(others)
The cleaning sheets stored in the sanitary tissue paper storage container 100 are not necessarily limited to those wound in a roll, but it is also possible to use so-called pop-up sheets, in which the sheets are stacked in an alternating folded state so that when one cleaning sheet is removed, the next cleaning sheet is also pulled out to the removal hole 33.
Furthermore, the shape of the sanitary tissue paper storage container 100 does not necessarily have to be cylindrical.

Next, we will explain the results of an evaluation of the ease of use of cleaning sheets based on examples and comparative examples. The present invention will be explained in detail below using examples, but the present invention is not limited to these.

<Sample creation>
The sheet material of the cleaning sheet used in the following tests was a nonwoven fabric with a fiber blend of PET/PP·PE/rayon=40/20/40.
This nonwoven fabric was produced by the spunlace process so as to form a herringbone pattern in which the fibers cross diagonally.

<Stain removal test>
For the example, a "chemical solution A" was prepared with the following composition as the chemical solution to be impregnated into the cleaning sheet (sheet material). The pH of this chemical solution A was 6.0.
Citric acid: 0.02 [wt%]
Sodium citrate: 0.13 [wt%]
Polyoxyethylene alkyl ether: 0.10 [wt%]
Ethanol: 10% by weight
A sheet material having a basis weight of 45 gsm was impregnated with this chemical solution A to obtain a cleaning sheet having an impregnation rate of 220%.
Furthermore, a comparative chemical solution, "Chemical Solution B," was prepared according to the following formulation. The pH of this chemical solution B was 6.0.
Citric acid: 0.02 [wt%]
Sodium citrate: 0.13 [wt%]
Ethanol: 10% by weight
A cleaning sheet having a basis weight of 45 gsm was impregnated with this chemical solution B to give a 220% impregnation, which was used as a sample of Comparative Example 1.

(Test Method)
0.5 cc of cafe au lait (Mild Cafe au Lait, manufactured by Ezaki Glico Co., Ltd.) was dropped onto the center of a 320 mm long polypropylene plate, and the plate was dried at 60° C. for 1 hour to adjust the amount of soiling that had adhered to the plate.
A cleaning sheet sample (one sheet measuring 200 mm x 140 mm) is placed on the right end of the polypropylene plate, and a 275 g weight is placed on top of it.
Here, two polypropylene plates with cafe au lait stains were prepared, and the sample of Example 1 was set on one polypropylene plate, and the sample of Comparative Example 1 was set on the other polypropylene plate.
The cleaning sheet sample with the weight placed thereon is then moved to the left end of the polypropylene plate over a period of about 4 seconds, and then moved from the left end to the right end of the polypropylene plate over a period of about 4 seconds.
This reciprocation was repeated 25 times, and the state of the stain was observed after each repetition.
As a result of this stain removal test, it was confirmed that the sample of Example 1 containing polyoxyethylene alkyl ether removed stains adhering to the polypropylene plate more quickly than the sample of Comparative Example 1 containing no polyoxyethylene alkyl ether.

<Pop-up sensory evaluation test>
A cleaning sheet sample of Example 1 was prepared by impregnating 220% of the above-mentioned chemical solution A in a roll of 70 sheets of 45 gsm sheet material connected together via perforations.
A cleaning sheet sample of Example 2 was prepared by impregnating 250% of the above-mentioned chemical solution A in a roll of 70 sheets of 35 gsm sheet material connected together via perforations.
A sample of Comparative Example 2 was a cleaning sheet obtained by impregnating 220% of the above-mentioned chemical solution A in a roll of 70 sheets of 50 gsm sheet material connected together via perforations.

(Test Method)
Each of the three samples was placed in a sanitary tissue paper storage container 100, and the ease of removing 70 samples sequentially from the removal section 3 (removal hole 33) was evaluated on a five-point scale (easy to remove, somewhat easy to remove, normal, somewhat difficult to remove, difficult to remove).
Ten examiners conducted a sensory evaluation test for each sample.
The evaluation results for Example 1 were: easy to take out 12%, somewhat easy to take out 38%, average 42%,
8% were slightly difficult to remove, and 0% were difficult to remove, giving an overall rating of "Excellent".
The evaluation results for Example 2 were: easy to take out 5%, somewhat easy to take out 47%, normal 38%,
10% were slightly difficult to remove, and 0% were difficult to remove, giving an overall rating of "good."
The evaluation results for Comparative Example 2 were: easy to take out 0%, somewhat easy to take out 14%, normal 54%,
32% were slightly difficult to remove, and 0% were difficult to remove, giving an overall rating of "Fair."
As a result of this pop-up property sensory evaluation test, the cleaning sheet with a basis weight of 45 gsm (Example 1) was highly rated, while the cleaning sheet with a basis weight of 50 gsm (Comparative Example 2) was poorly rated.
This is due to the balance of frictional resistance between the ejection hole 33 of the ejection part 3 and the cleaning sheet pulled out from the ejection hole 33 .

<Damage verification test for cleaning objects>
For the comparative example, a chemical solution C was prepared with the following composition as the chemical solution to be impregnated into the cleaning sheet (sheet material). The pH of this chemical solution C was 9.0.
Sodium hydroxide: 0.015 [wt%]
Polyoxyethylene alkyl ether: 0.10 [wt%]
Ethanol: 10% by weight
A cleaning sheet having a basis weight of 45 gsm was impregnated with this chemical solution C having a pH of 9.0, to obtain a cleaning sheet having an impregnation rate of 220%, which was used as a sample of Comparative Example 3.
A damage verification test was carried out using the sample of Comparative Example 3 and the sample of Example 1, in which a sheet material having a basis weight of 45 gsm was impregnated with Chemical Solution A having a pH of 6.0 to a level of 220%.

(Test Method)
Various materials were prepared to represent the objects to be cleaned, and each material was cut into 5 cm squares. The materials prepared to represent the objects to be cleaned were varnished wood, polystyrene, ABS resin, vinyl chloride, stainless steel, iron, and brass.
The color of each material is measured in advance using a color difference meter (NF333 simple spectrocolor difference meter manufactured by Nippon Denshoku Industries Co., Ltd.).
Each material was then wrapped in a sample of cleaning sheet and placed in a sealed bag and left at room temperature.
After leaving for 18 hours, the materials were removed from the bags and dried in a thermostatic chamber at 40°C for one day. The color of each material after drying was measured with a color difference meter, and the color difference ΔE from the original color was measured. The larger the ΔE value, the greater the degree of discoloration.
Here, the greater the degree of discoloration, the more damaged the item is determined to be.
The color difference for the varnished wood was ΔE=3.059 for Comparative Example 3 and ΔE=0.777 for Example 1.
The color difference for the polystyrene material was ΔE=0.716 for Comparative Example 3 and ΔE=0.203 for Example 1.
The color difference for the ABS resin material was ΔE=1.062 in Comparative Example 3 and ΔE=0.685 in Example 1.
The color difference for the vinyl chloride material was ΔE=0.660 in Comparative Example 3 and ΔE=0.171 in Example 1.
The color difference for the stainless steel material was ΔE=0.395 in Comparative Example 3 and ΔE=0.139 in Example 1.
As for the iron material, rust occurred in Comparative Example 3, but no rust occurred in Example 1.
Regarding the brass material, a lot of rust occurred in Comparative Example 3, but little rust occurred in Example 1.
As a result of the test to verify damage to the object to be cleaned, it was confirmed that the sample of Example 1 (impregnated with chemical solution A of pH 6.0) showed less discoloration of the material (smaller ΔE value) and less rust formation than the sample of Comparative Example 1 (impregnated with chemical solution C of pH 9.0), and therefore caused less damage to the object to be cleaned.

From the above test results, it was confirmed that the cleaning sheet P of the present invention is easy to remove from the sanitary tissue paper storage container 100, has good wiping properties for dirt, and causes little damage to the object being cleaned.
In other words, the cleaning sheet P according to the present invention can be used in a variety of situations as a user-friendly cleaning sheet.

Note that the application of the present invention is not limited to the above-described embodiment, and modifications can be made as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Container body 11 Male thread portion 2 Lid 21 Lid body body 21a Top surface portion 21b Side surface portion 21c Recessed portion 21d Hole portion 21e Body side wall portion 211 Female thread portion 22 Small lid 22a Small lid side wall portion 3 Removal portion 3a Inner bottom surface 3b Lower surface 31 Recessed portion 32 Narrowed portion 33 Removal hole 33a Small hole 33b Slit 33h Hole wall 341 First chamfered portion 342 Second chamfered portion 100 Sanitary tissue paper storage container P Cleaning sheet

Claims (1)

A cleaning sheet in which a sheet material capable of retaining liquid is impregnated with a chemical solution,
The basis weight of the sheet material is 35 gsm or more and 45 gsm or less,
A herringbone pattern is formed on the entire surface of the sheet material in a manner that fibers cross obliquely due to regions of different fiber densities,
the chemical solution contains polyoxyethylene alkyl ether as a surfactant, an organic acid, and a salt of an organic acid, and the chemical solution exhibits a neutral pH of 6 or more and 7 or less due to the buffering action of the organic acid and the salt of the organic acid ;
The cleaning sheet is stored in a storage container in a roll shape with multiple sheets connected via perforations, and is used by pulling out one sheet at a time from an ejection hole in an ejection part provided in the storage container,
the oblique lines of the herringbone pattern formed on the cleaning sheet are arranged to form an acute angle with respect to the direction in which the cleaning sheet is pulled out,
When the cleaning sheet is pulled out from the removal hole, resistance is applied from the hole wall, causing the cleaning sheet to be pulled out and used to be cut along the perforations, and the end of the succeeding cleaning sheet is held in a state where it protrudes from the removal hole .