JP7648364B2 - Cleaning wipes - Google Patents

Description

The present invention relates to a wet cleaning sheet.

It has been known that embossing the cleaning surface of a wet cleaning sheet with convex parts improves the ease of wiping off dirt, operability, and visibility of dirt on the sheet (see, for example, Patent Document 1).

JP 2018-064723 A

However, in the case of wet cleaning sheets as shown in Patent Document 1, the projections on the sheet are aligned in a straight line (for example, in the direction of the long axis), which can result in areas on the surface to be cleaned that have not been wiped by the projections (so-called "wiping streaks"). When a user sees the wiping streaks, they may decide that the sheet has run out of chemical solution and dried out, even though there is still chemical solution remaining in the sheet, and discard the sheet, which can result in the user using many sheets unnecessarily.

The object of the present invention is to provide a cleaning wet sheet that can reduce the occurrence of wiping streaks when attached to a cleaning tool having a head portion and used for wiping.

The invention described in claim 1 is a wet cleaning sheet comprising a base paper sheet impregnated with a chemical solution and attached to a cleaning tool having a head portion,
The cleaning wet sheet has a first surface on which a convex embossment is formed , and a second surface on which a concave embossment is formed ,
The convex embossments include a plurality of first convex embossments and a plurality of second convex embossments having different major axis directions,
The concave embossments include a plurality of first concave embossments and a plurality of second concave embossments each having different orientations in the major axis direction,
The first convex embossments and the first concave embossments adjacent to each other in a minor axis direction perpendicular to the major axis direction are arranged to partially overlap each other in the minor axis direction and to be shifted in the major axis direction,
The second convex embossments and the second concave embossments adjacent to each other in the minor axis direction are arranged to overlap each other in the minor axis direction and to be shifted in the major axis direction,
the first convex embossments and the second convex embossments , and the first concave embossments and the second concave embossments are adjacent to each other with an overlap of 0.1 mm or more, and are continuously arranged from a first side of the cleaning wet sheet to a second side opposite to the first side, so that a straight line passing through a center of the major axis direction and the minor axis direction at an angle of 45° with respect to the major axis direction and the minor axis direction passes through the center of the major axis direction and the minor axis direction, and the major axis direction forms a substantially right angle ;
The plurality of first convex embossments and second convex embossments, and the plurality of first concave embossments and second concave embossments are alternately arranged from the first side to the second side .

The invention described in claim 2 is the cleaning wet sheet described in claim 1 ,
The embossment is elliptical in shape and has a constricted portion at approximately the center in the major axis direction.

The present invention provides a cleaning wet sheet that can reduce the occurrence of wiping streaks when attached to a cleaning tool having a head portion and used for wiping.

FIG. 2 is a perspective view showing a state in which the wet cleaning sheet of the present embodiment is in use. FIG. 2 is a plan view showing the cleaning wet sheet of the present embodiment. FIG. 13 is a diagram showing an embossed block of a wet cleaning sheet according to a modified example. FIG. 11 is a plan view showing a modified example of a wet cleaning sheet. FIG. 13 is a diagram showing an embossed block of a wet cleaning sheet according to a modified example. FIG. 11 is a plan view showing a modified example of a wet cleaning sheet.

Hereinafter, a wet cleaning sheet 100 according to an embodiment of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples, and is determined solely based on the description of the claims.
In the following description, the X direction, Y direction, and Z direction are defined as shown in FIG.

[Configuration of the embodiment]
FIG. 1 is a diagram showing a state in which a wet cleaning sheet 100 according to the present embodiment is in use.
As shown in FIG. 1, the cleaning wet sheet 100 is a sheet formed by plying (laminated) multiple base paper sheets, which is replaceably attached to a cleaning tool 200 having, for example, a rectangular, flat head portion 201 and a handle portion 202 attached to the upper surface of the head portion 201 and used for cleaning floors.
The cleaning wet sheet 100 covers the bottom surface of the head part 201 of the cleaning tool 200 to form a cleaning surface, and is folded along the longitudinal edge 201a of the head part 201 of the cleaning tool 200 and engaged with the upper surface of the head part 201 to be attached.
The long edges 201a refer to edges along the long direction of the head portion 201. In other words, they refer to the two longer edges of the four edges of the rectangular head portion 201.

The base paper sheet is not particularly limited as long as it is a fiber assembly, but may be, for example, a single-layer or multi-layer paper, a nonwoven fabric, or a paper mixed with synthetic fibers. When the base paper sheet is made of nonwoven fabric, it is manufactured by bonding specific fibers together using well-known techniques such as spunlace, air-through, air-laid, point bond, spun bond, and needle punch.

The specified fibers may be natural, regenerated, or synthetic, and examples of such fibers include hydrophilic cellulosic fibers such as rayon, lyocell, tencel, and cotton, and hydrophobic 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 with at least one hydrophilic and one hydrophobic type.

The fibers preferably have a fineness of 1.1 dtex to 5.5 dtex. If the fineness is less than 1.1 dtex, the pores between the fibers are small, which is not preferable for collecting fiber waste and hair. If the fineness is more than 5.5 dtex, the retained chemical solution tends to be released, which is not preferable.
Furthermore, the fiber length of these fibers may be any length suitable for production.

In addition, when the base paper sheet is made of paper, the pulp used as the raw material can be bleached hardwood kraft pulp (LBKP), bleached softwood kraft pulp (NBKP), unbleached hardwood kraft pulp (LUKP), unbleached softwood kraft pulp (NUKP), hardwood sulfite pulp, softwood sulfite pulp, etc., and any suitable blend of these in any ratio is suitable.

More preferably, the blending ratio of hardwood bleached kraft pulp exceeds 50% by weight, that is, the blending ratio of softwood bleached kraft pulp to hardwood bleached kraft pulp is less than 1: 1. By increasing the blending ratio of hardwood bleached kraft pulp to softwood bleached kraft pulp, the inter-fiber gaps are reduced and moisture evaporation is suppressed, thereby improving the difficulty in drying.
It may also be made of crushed pulp or crushed pulp covered or sandwiched between water-disintegrable paper.

(Eyewear)
In the case of the cleaning wet sheet 100 of the present invention, the basis weight is preferably 20 to 100 g/m ² , and particularly preferably about 30 to 60 g/m ^2. If the basis weight of the sheet is less than 20 g/m ² , the sheet will have poor dirt retention ability and will tend to wrinkle and become unstable during cleaning. If the basis weight exceeds 100 g/m ² , the sheet will have poor flexibility, making it difficult to attach the cleaning wet sheet 100 to the cleaning tool 200.

[Water-soluble binder]
In addition, the base paper sheet is provided with a water-soluble binder for increasing the strength of the paper. Examples of the water-soluble binder include binder components such as carboxymethyl cellulose (CMC), polyvinyl alcohol, starch or its derivatives, hydroxypropyl cellulose, sodium alginate, trant gum, guar gum, xanthan gum, gum arabic, carrageenan, galactomannan, gelatin, casein, albumin, purpuran, polyethylene oxide, viscose, polyvinyl ethyl ether, sodium polyacrylate, sodium polymethacrylate, polyacrylamide, hydroxylated derivatives of polyacrylic acid, polyvinylpyrrolidone/vinylpyrrolidone vinyl acetate copolymer, etc.

In particular, it is preferable to use a water-soluble binder having a carboxyl group, since the binder can exhibit wet strength through a crosslinking reaction.
The water-soluble binder having a carboxyl group is an anionic water-soluble binder that easily forms a carboxylate in water. Examples of such binders include polysaccharide derivatives, synthetic polymers, and natural products.

(Polysaccharide Derivatives)
Examples of the polysaccharide derivative include salts of CMC, carboxyethyl cellulose or a salt thereof, and carboxymethylated starch or a salt thereof, and in particular, alkali metal salts of CMC are preferred.

(CMC)
The degree of etherification of CMC is preferably 0.6 to 2.0, particularly preferably 0.9 to 1.8, and even more preferably 1.0 to 1.5, because this results in extremely good water disintegrability and wet paper strength.
It is also preferable to use a water-swellable CMC, because the CMC exhibits a function of binding together the fibers constituting the base-paper sheet while remaining unswelled by crosslinking with aluminum ions, which are a crosslinking agent in the chemical solution in this embodiment, and can provide the cleaning wet sheet 100 with the strength required for cleaning and wiping operations.
In the case of the wet cleaning sheet 100 of this embodiment, CMC is added as the water-soluble binder.

The CMC may be uniformly impregnated in the thickness direction of the base paper sheet, but it is preferable that the CMC content gradually increases from the center in the thickness direction of the base paper sheet toward the front and back surfaces. This makes the cleaning wet sheet 100 less likely to tear even when the cleaning surface is rubbed hard, compared to conventional products that are uniformly impregnated with the same amount of water-soluble binder.

(Synthetic polymer)
Examples of synthetic polymers include salts of polymers or copolymers of unsaturated carboxylic acids, salts of copolymers of unsaturated carboxylic acids and monomers copolymerizable with the unsaturated carboxylic acids, etc. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic anhydride, maleic acid, fumaric acid, etc. Examples of monomers copolymerizable with these include esters of these unsaturated carboxylic acids, vinyl acetate, ethylene, acrylamide, vinyl ether, etc. Particularly preferred synthetic polymers are those using acrylic acid or methacrylic acid as the unsaturated carboxylic acid, specifically polyacrylic acid, polymethacrylic acid, salts of acrylic acid-methacrylic acid copolymers, and salts of copolymers of acrylic acid or methacrylic acid with alkyl acrylate or alkyl methacrylate.
Natural products include sodium alginate, xanthan gum, gellan gum, taragacanth gum, and pectin.

(CNF)
Furthermore, cellulose nanofiber (CNF) can be added to the cleaning wet sheet 100.
That is, CNF can be added to the water-soluble binder (CMC in this embodiment), and the specific surface area of the base paper sheet becomes larger than that of a base paper sheet composed only of pulp.

Here, CNF refers to fine cellulose fibers obtained by defibrating pulp fibers, and generally refers to cellulose fibers containing cellulose fine fibers with a fiber width of nano-size (1 nm or more and 1000 nm or less), but fibers with an average fiber width of 100 nm or less are preferable. The average fiber width can be calculated, for example, using a fixed number of number averages, medians, mode diameters (mode values), etc.

The CNF may be uniformly impregnated in the thickness direction of the base paper sheet, but it is preferable that the CNF content gradually increases from the center in the thickness direction of the base paper sheet toward the front and back surfaces. This makes the cleaning wet sheet 100 less likely to tear even when the cleaning surface is rubbed hard, compared to conventional products that are uniformly impregnated with the same amount of water-soluble binder.

(Pulp fibers that can be used for CNF)
Pulp fibers that can be used to produce CNF include chemical pulps such as hardwood pulp (LBKP) and softwood pulp (NBKP); mechanical pulps such as bleached thermomechanical pulp (BTMP), stone ground pulp (SGP), pressed stone ground pulp (PGW), refiner ground pulp (RGP), chemi-ground pulp (CGP), thermo-ground pulp (TGP), ground pulp (GP), thermomechanical pulp (TMP), chemi-thermomechanical pulp (CTMP), and refiner mechanical pulp (RMP); waste paper pulp produced from brown paper, kraft envelope paper, magazine paper, newspaper paper, flyer paper, office paper, cardboard paper, white paper, Kent paper, imitation paper, land certificate paper, and recycled paper; and deinked pulp (DIP) produced by deinking waste paper pulp. These may be used alone or in combination of two or more kinds, so long as the effects of the present invention are not impaired.

(CNF defibration method)
Examples of defibration methods used in the production of CNF include mechanical methods such as a high-pressure homogenizer method, a microfluidizer method, a grinder grinding method, a bead mill freeze-pulverizing method, and an ultrasonic defibration method, but are not limited to these methods.
In addition, CNF that has been subjected to only mechanical treatment (not modified) using the above-mentioned defibration method, i.e., CNF that has not been modified with functional groups, has higher thermal stability than CNF modified with functional groups such as phosphate groups and carboxymethyl groups, and can therefore be used for a wider range of applications; however, CNF modified with functional groups such as phosphate groups and carboxymethyl groups can also be used in the present invention.
In addition, for example, pulp fibers may be mechanically defibrated and then chemically treated, such as carboxymethylation, or may be enzymatically treated. Examples of CNF that have been chemically treated include individualized CNF (iCNF) (single nanocellulose) with a diameter of 3 to 4 nm, such as TEMPO-oxidized CNF, phosphate-esterified CNF, and phosphite-esterified CNF.
In addition, CNF that has been subjected to only chemical or enzymatic treatment, or CNF that has been subjected to chemical or enzymatic treatment and then mechanical defibration treatment may be used.

[Chemical solution]
The cleaning wet sheet 100 of this embodiment is impregnated with a predetermined chemical solution containing an auxiliary such as glycol ethers, an aqueous detergent, a preservative, a disinfectant, a lower alcohol, an organic solvent, etc. The chemical solution is impregnated in an amount of 100% by mass to 500% by mass, preferably 150% by mass to 300% by mass, based on the mass of the base paper sheet which is the substrate of the cleaning wet sheet 100.
The chemical solution is impregnated into the base paper sheet that has been dried after the water-soluble binder has been applied thereto, and the chemical solution impregnated into the hydrophilic fibers is released from the front or back surface of the cleaning wet sheet 100 when it is used.

[Cleaning Wet Sheets]
FIG. 2 is a plan view showing an example of the wet cleaning sheet 100 of the present embodiment.
As shown in FIG. 2, the cleaning wet sheet 100 has a generally rectangular shape that is elongated in the X direction, and is formed, for example, to be 250 mm to 300 mm, preferably 260 mm to 290 mm, in the X direction (longitudinal direction) and 180 mm to 230 mm, preferably 200 mm to 210 mm, in the Y direction (transverse direction).

In the wet cleaning sheet 100, the portion that is folded along the longitudinal edge 201a of the head portion 201 of the cleaning tool 200 is referred to as a folded portion S.
The approximate positions of the folding parts S are set in advance to match the head part 201 of the specified cleaning tool 200. That is, two rows of folding parts S extending in the X direction are set at predetermined positions in the Y direction of the wet cleaning sheet 100. Note that the folding parts S may be recognized by a user by, for example, printing straight lines corresponding to the folding parts S on the wet cleaning sheet 100 in advance, or by forming fold lines corresponding to the folding parts S on the wet cleaning sheet 100.
The embossments 20 are arranged over substantially the entire surface of the wet cleaning sheet 100.

(Embossed)
The embossments 20 are portions of the wet cleaning sheet 100 where the sheet is compressed in the Z direction.
2, the embossment 20 is formed in a so-called gourd shape, which is an ellipse that is short in one direction and narrow in width in a plan view and has a constricted portion at approximately the center in the long axis direction. The shape of the embossment 20 is not limited to this, and may be various shapes such as a polygon or a combination of various shapes, but from the viewpoint of improving the ability to scrape off dirt, such a gourd shape is preferable.

The embossing 20 can be formed by thermal embossing under conditions of, for example, a temperature of 80° C. to 200° C. and an embossing pressure of 0.2 MPa to 1.0 MPa. When the embossing 20 is formed by thermal embossing, the convex embossing roll can be one whose outer circumferential surface is made of carbon steel, stainless steel, polypropylene, hardened resin such as ABS (Acrylonitrile Butadiene Styrene) resin, or the like. Among these, it is preferable to use one made of stainless steel from the viewpoints of durability and heat resistance.
Furthermore, when embossing is performed by thermal embossing, it is preferable to perform this before the step of impregnating the wet cleaning sheet 100 with a chemical solution, in order to easily impart the uneven shape.

(Convex embossing, concave embossing)
The embossment 20 includes a convex embossment 21 that is convex on the upper side in the Z direction (the first surface side of the wet cleaning sheet 100) and a concave embossment 22 that is convex on the lower side (the second surface side of the wet cleaning sheet 100) (i.e., concave on the upper side in the Z direction). In Fig. 1 to Fig. 4B, the convex embossment 21 is indicated by a solid line, and the concave embossment 22 is indicated by a dashed line.
The convex embossment 21 is formed to have a size of 5 mm to 10 mm, preferably 6 mm to 8 mm, in the long axis direction, 2 mm to 5 mm, preferably 3 mm to 4 mm, in the short axis direction perpendicular to the long axis direction, and 0.5 mm to 2 mm, preferably 0.7 mm to 1.5 mm (height from an intermediate portion (described later)) in the Z direction. The concave embossment 22 is formed upside down and in substantially the same shape as the convex embossment 21 in a cross-sectional view, and is formed to have a shape that is convex downward in the Z direction.

(Middle part)
An intermediate portion is formed between each of the embossments 20 formed on the cleaning wet sheet 100. Since the intermediate portion is a portion where no embossment 20 is formed, the intermediate portion is located lower than the convex embossment 21 and higher than the concave embossment 22 in the Z direction.

[Emboss pattern]
As shown in Fig. 2, the cleaning wet sheet 100 according to this embodiment is provided with a plurality of first convex embossments 211 and second convex embossments 212, each having a different orientation in the long axis direction, as the convex embossments 21. The first convex embossments 211 adjacent to each other in the short axis direction are arranged so that a portion of each of the first convex embossments 211 overlaps with each other in the short axis direction and is shifted in the long axis direction. The second convex embossments 212 adjacent to each other in the short axis direction are arranged so that a portion of each of the second convex embossments 212 overlaps with each other in the short axis direction and is shifted in the long axis direction. The plurality of first convex embossments 211 and second convex embossments 212 are arranged continuously from the first side a of the cleaning wet sheet 100 to the second side b opposite to the first side a.

Normally, the cleaning wet sheet 100 attached to the cleaning tool 200 having the head portion 201 is moved approximately perpendicular to the X or Y direction when wiping, but in the case of the cleaning wet sheet 100 having the embossed pattern described above, the convex embossing 21 creates an overlap that connects two opposing sides of the cleaning wet sheet 100 in the X or Y direction, reducing the occurrence of wiping streaks when wiping.

In particular, the first convex embossing 211 and the second convex embossing 212 are preferably arranged so that a straight line at an angle of 45° to the X direction passes through the center of the long axis direction and the short axis direction. In addition, it is preferable that adjacent first convex embossings 211 and second convex embossings 212 have an overlap of at least 0.1 mm in the short axis direction and are arranged so that the deviation in the long axis direction is within 5 mm (i.e., within the width of the long axis direction of the convex embossing 21). In addition, it is preferable that the first convex embossing 211 and the second convex embossing 212 are arranged adjacent to each other so that the long axis direction forms a substantially right angle, as shown in FIG. 2.

By using such an embossing pattern, the convex embossments 21 are always arranged within the range of a straight line drawn at an angle of 0° to 30° from one vertex of the cleaning wet sheet 100, and within the range of a straight line drawn at an angle of 60° to 90°. Therefore, when the cleaning wet sheet 100 is moved within 30° of the X direction and Y direction, i.e., in a direction of 0° to 30°, 60° to 120°, 150° to 210°, 240° to 300°, or 330° to 360°, the convex embossments 21 overlap each other, further reducing the occurrence of wiping streaks.

In such a cleaning wet sheet 100, it is preferable that the concave embossments 22 are a first concave embossment 221 and a second concave embossment 222 that are oriented in different longitudinal directions and are arranged in the same embossing pattern as the convex embossments 21.

Specifically, the concave embossings 22 include a first concave embossing 221 and a second concave embossing 222 that are oriented differently in the long axis direction. The second concave embossings 222 adjacent to each other in the short axis direction perpendicular to the long axis direction are arranged so that a portion of the second concave embossings 222 overlaps with a portion of the second concave embossings 222 in the short axis direction and are shifted in the long axis direction. The second concave embossings 222 adjacent to each other in the short axis direction are arranged so that a portion of the second concave embossings 222 overlaps with a portion of the second concave embossings 222 in the short axis direction and are shifted in the long axis direction. Such a plurality of second convex embossings 212 and second concave embossings 222 are continuously arranged from the first side a of the cleaning wet sheet 100 to the second side b opposite to the first side a.

By arranging the concave embossments 22 in the same embossing pattern as the convex embossments 21, not only the first surface of the cleaning wet sheet 100 on which the convex embossments 21 are arranged, but also the second surface of the cleaning wet sheet 100 on which the concave embossments 22 on the first surface are convex upward in the Z direction has the same level of cleaning ability as the first surface, thereby increasing the cleaning area per sheet of the cleaning wet sheet 100.

[Modification 1]
The embossed pattern on the wet cleaning sheet 100 is not limited to the above.
For example, as shown in FIG. 3A, a plurality of approximately rectangular embossed blocks 30 each consisting of a combination of a convex embossment 21 and a concave embossment 22 are arranged along the X direction from a first side a of the cleaning wet sheet 100 to a second side b opposite the first side a, as shown in FIG. 3B, and a plurality of embossed block rows 31 are arranged continuously along the Y direction from a third side c to a fourth side d.

In this case, for example, by arranging the adjacent first embossed block row 31 and the adjacent second embossed block row 31 so that they are shifted in the X direction, the convex embossment 21 and the concave embossment 22 in the first embossed block 30 are oriented in a different direction from the convex embossment 21 and the concave embossment 22 in the adjacent second embossed block 30 in the long axis direction and are arranged so that they partially overlap the adjacent convex embossment 21 and the concave embossment 22 in the second embossed block 30 in the short axis direction, overlapping areas are created between the multiple convex embossments 21 from the first side a to the second side b and from the third side c to the fourth side d of the cleaning wet sheet 100, so that the occurrence of wiping streaks can be reduced when the cleaning wet sheet 100 is attached to a cleaning tool 200 having a head portion 201 and used for wiping.

[Modification 2]
Furthermore, the configuration of the embossed block 30 is not limited to the above. For example, in an embossed block 30 in which the convex embossments 21 and the concave embossments 22 are alternately arranged in the X direction and the Y direction, the major axis directions of the convex embossments 21 and the concave embossments 22 may be tilted within a range of 30° to 60° with respect to the X direction, so that the embossed block 30 has a diamond shape, as shown in FIG. 4A .

As shown in Figure 4B, in the same manner as in variant example 1, multiple embossed block rows 31 each consisting of an embossed block arranged continuously from the first side a to the second side b are arranged continuously from the third side c to the fourth side d, and when the convex embossments 21 and the concave embossments 22 in the second embossing block 30 are arranged in a direction different from the long axis direction of the convex embossments 21 and the concave embossments 22 in adjacent first embossing blocks 30 and so that they partially overlap in the short axis direction, the embossed blocks 30 are inevitably arranged so as to be misaligned with each other, since the embossed blocks 30 are diamond-shaped.
Therefore, there is no need to intentionally arrange the first embossed block row 31 and the second embossed block row 31 so as to be misaligned.

(Non-embossed part)
As shown in FIG. 4B, between the embossed blocks 30, the wet cleaning sheet 100 may be provided with non-embossed portions 40 that are not compressed in the Z direction and have raised naps.

The non-embossed portion 40 can be formed by designing the convex embossing roll that forms the embossment 20 so as to exclude the shape of the non-embossed portion 40, or by compressing it lightly compared to the compressed portion of the embossment 20 so that the nap remains.
By providing the non-embossed portion 40, when the wet cleaning sheet 100 is moved in a specified direction to clean, dirt tends to accumulate in the non-embossed portion 40, thereby improving the dirt collection performance.

However, as shown in FIG. 4B, if the non-embossed portion 40 is formed to be in a straight line, wiping streaks may easily occur depending on the angle at which the cleaning wet sheet 100 is moved. Therefore, it is preferable to position the first embossed block 30 at a position offset from the adjacent second embossed block 30 so that the non-embossed portion 40 is not in a straight line.

In the embossing patterns of the above-mentioned modified examples 1 and 2, it is also preferable that adjacent convex embossments 21 are arranged adjacent to each other so that their major axis directions form approximately right angles.

Of course, other specific details of the structure can be modified as appropriate.
For example, the chemical solution impregnated into the wet cleaning sheet 100 can be changed depending on the application.
In addition, the wet cleaning sheet 100 has been described as being formed by plying (laminating) a plurality of base paper sheets, but this is not limited thereto, and the wet cleaning sheet 100 may be formed of a single layer.
In addition, in Figures 2 and 4B, the first side a and the second side b are the long sides of the cleaning wet sheet 100, and in Figure 3B, the third side c and the fourth side d are the long sides, but this is not limited to this.

In addition, in Figures 2 to 4B, the convex embossing 21 and the concave embossing 22 are both gourd-shaped, which are approximately the same shape when viewed in a plan view, but the convex embossing 21 and the concave embossing 22 may have different shapes.

However, in any of the above embossing patterns, it is preferable that the convex embossments 21 and the concave embossments 22 arranged on the wet cleaning sheet 100 are of substantially the same shape and number. In this way, the first and second sides of the wet cleaning sheet 100 have substantially the same cleaning function, and the cleaning area per wet cleaning sheet 100 can be increased.

100 Wet cleaning sheet 20 Embossment 21 Convex embossment 211 First convex embossment 212 Second convex embossment 22 Concave embossment 221 First concave embossment 222 Second concave embossment 30 Embossed block 31 Embossed block row a First side b Second side c Third side d Fourth side

Claims (2)

A wet cleaning sheet comprising a base paper sheet impregnated with a chemical solution and attached to a cleaning tool having a head portion,
The cleaning wet sheet has a first surface on which a convex embossment is formed , and a second surface on which a concave embossment is formed ,
The convex embossments include a plurality of first convex embossments and a plurality of second convex embossments having different major axis directions,
The concave embossments include a plurality of first concave embossments and a plurality of second concave embossments each having different orientations in the major axis direction,
The first convex embossments and the first concave embossments adjacent to each other in a minor axis direction perpendicular to the major axis direction are arranged to partially overlap each other in the minor axis direction and to be shifted in the major axis direction,
The second convex embossments and the second concave embossments adjacent to each other in the minor axis direction are arranged to overlap each other in the minor axis direction and to be shifted in the major axis direction,
the first convex embossments and the second convex embossments , and the first concave embossments and the second concave embossments are adjacent to each other with an overlap of 0.1 mm or more, and are continuously arranged from a first side of the cleaning wet sheet to a second side opposite to the first side, so that a straight line passing through a center of the major axis direction and the minor axis direction at an angle of 45° with respect to the major axis direction and the minor axis direction passes through the center of the major axis direction and the minor axis direction, and the major axis direction forms a substantially right angle ;
The cleaning wet sheet is characterized in that the plurality of first convex embossments and second convex embossments, and the plurality of first concave embossments and second concave embossments are alternately arranged from the first side toward the second side . 2. The wet cleaning sheet according to claim 1 , wherein the embossment is elliptical in shape and has a constricted portion at approximately the center in the major axis direction.

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