JP7569652B2 - CLEANING SHEET, LAMINATE OF CLEANING SHEET, CLEANING TOOL, AND METHOD FOR MANUFACTURING CLEANING SHEET - Google Patents

Description

The present invention relates to a cleaning sheet, a laminate of cleaning sheets, a cleaning tool equipped with a cleaning sheet, and a method for manufacturing a cleaning sheet.

Various cleaning tools (wiping tools) for cleaning floor surfaces such as hardwood floors are widely known. This type of cleaning tool includes, for example, a head attached to the end of a rod-shaped handle and a cleaning sheet that is detachable from the head, and is used by fixing the cleaning sheet to the head (Patent Document 1).
The cleaning tool described in Patent Document 1 can capture dirt (objects to be removed) on an object to be cleaned, such as a floor, by sliding one side (cleaning side) of the cleaning sheet against the surface of the object to be cleaned.

Japanese Patent Application Publication No. 9-220191

The cleaning sheet described in Patent Document 1, which is fixed to a cleaning tool for use, includes a fiber sheet having fibers assembled therein. More specifically, the cleaning sheet described in Patent Document 1 includes an outermost fiber sheet having a plurality of holes formed therethrough in the thickness direction, and an adhesive layer superimposed on the fiber sheet. According to the cleaning sheet described in Patent Document 1, the fine fiber structure of the fiber sheet can be utilized to scrape off and capture dirt. Furthermore, if dirt gets into the holes, the trapped dirt can be captured by the adhesive force of the surface of the adhesive layer, and the captured state can be maintained.
However, in the cleaning sheet described in Patent Document 1, holes are simply formed in the fiber sheet, so it cannot be said that the adhesive layer can effectively capture dirt in the depressions of the holes. In other words, the performance of capturing dirt by the adhesive layer in the holes is not necessarily good.
Therefore, conventional cleaning sheets such as those disclosed in Patent Document 1 have the problem that they do not have good dust trapping properties.

In view of the above problems, the present invention aims to provide a cleaning sheet that has at least good dirt trapping properties, and a cleaning tool equipped with the cleaning sheet.

The cleaning sheet according to the present invention is a cleaning sheet having a cleaning surface that is brought into sliding contact with the surface of an object to be cleaned,
The cleaning surface has projections and recesses, and is used by bringing tips of the projections into sliding contact with the object to be cleaned;
the protrusions are formed of members spaced apart from one another in a surface direction of the cleaning surface,
the cleaning surface further has an adhesive recess having a higher adhesive strength than the member and exposed on the cleaning surface;
an adhesive layer extending in a surface direction of the cleaning surface and disposed in at least a part of the space between the members, at least a part of the adhesive layer constituting the adhesive recess, and a ratio of an exposed area of the adhesive layer to the cleaning surface being 30% or more;
The ratio (H/L) of the average convex height (H: mm) from the tip of the convex portion to the adhesive concave portion to the average length (L: mm) of the shape of the adhesive concave portion in a first direction in which the average length of the interval in the surface direction is smallest is 15× ^10-3 or more.

The cleaning sheet having the above-mentioned configuration has an uneven cleaning surface, and is used by sliding the tips of the protrusions against the object to be cleaned. Since the ratio of the exposed area of the adhesive layer is 30% or more, the adhesive recesses can sufficiently capture dirt. In addition, since the ratio (H/L) of the average protrusion height (H: mm) to the average length (L: mm) of the shape of the adhesive recesses is 15×10 ⁻³ or more, the adhesive recesses are prevented from contacting the surface of the object to be cleaned, and the tips of the protrusions can slide against the surface. Therefore, while the protrusions are in sliding contact with the object to be cleaned, dirt can be collected in the gaps in the members constituting the protrusions. Since the adhesive recesses, which are recesses that are relatively more adhesive than the protrusions, are arranged in the above-mentioned gaps, the collected dirt can be captured by the adhesive recesses. Moreover, the captured dirt can be held on the surface of the adhesive recesses by the adhesive force. Therefore, the above-mentioned cleaning sheet has good dirt collection properties.

In the cleaning sheet, the proportion of the exposed area of the adhesive layer on the cleaning surface may be greater than 50%. This allows the cleaning sheet to have better dirt capture properties.

In the above cleaning sheet, the average convex height (H) is preferably 1000×10 ⁻³ mm or less, more preferably 500×10 ⁻³ mm or less, and even more preferably 300×10 ⁻³ mm or less.
By setting the average convex height (H) to 500×10 ⁻³ mm or less, the depth of the recess from the tip of the convex to the adhesive concave becomes shallower. Therefore, during sliding contact, the adhesive concave can approach closer to the surface of the object to be cleaned. Therefore, the adhesive concave can capture dirt relatively easily and sufficiently. Therefore, the above cleaning sheet has better dirt capture properties.

In the above cleaning sheet, the average length (L) of the shape of the adhesive recess in a first direction in which the average length of the spacing in the surface direction is smallest is preferably 0.3 mm or more, more preferably 0.5 mm or more, even more preferably 0.8 mm or more, and particularly preferably 1.0 mm or more.
By setting the average length (L) of the shape of the adhesive recesses to 0.3 mm or more, the average size of each adhesive recess is relatively large, which allows the adhesive recesses to capture dirt more effectively, and therefore the cleaning sheet has better dirt capture properties.

In the above cleaning sheet, the minimum load of a load curve when the member of the convex portion is measured by a nanoindentation method is preferably −0.40 μN or more and 0 μN or less, and more preferably −0.10 μN or more and 0 μN or less.
In the above cleaning sheet, the minimum load of an unloading curve when the member of the convex portion is measured by a nanoindentation method is preferably −1.50 μN or more and 0 μN or less, and more preferably −0.10 μN or more and 0 μN or less.
In the above cleaning sheet, it is preferable that the cleaning surface has a static friction coefficient of 1.00 or less.
These configurations allow the cleaning sheet to have better slip properties.

The cleaning sheet preferably comprises an adhesive layer extending in the surface direction of the cleaning surface and disposed on the back side of the member, a part of the adhesive layer constituting the adhesive recess, the hardness of the member measured by the nanoindentation method being 0.4 MPa or more, and the probe tack of the adhesive layer measured by the probe tack method being 1.0 kN/ ^m2 or more and 500.0 kN/m2 ^or less.
By making the hardness of the member 0.4 MPa or more, the frictional force between the convex parts in sliding contact with the surface of the object to be cleaned and the surface of the object to be cleaned can be made relatively small, and therefore a cleaning sheet having such a member with a relatively high rigidity on its cleaning surface has good slip properties.
When the probe tack of the adhesive layer is 1.0 kN/m ² or more and 500.0 kN/m ² or less, better dirt trapping properties can be achieved.
Therefore, by having the hardness of the material constituting the convex portion be 0.4 MPa or more and the probe tack of the adhesive layer be 1.0 kN/ ^m2 or more and 500.0 kN/m2 ^or less, it is possible to achieve better dirt capture properties while also achieving good slip properties.

In the above cleaning sheet, it is preferable that the material of the protruding portion contains at least one of wax, hardened resin, and inorganic powder.

In the above cleaning sheet, the material of the convex portion may contain at least one of polyolefin resin, ethylene-vinyl acetate copolymer resin (EVA), styrene-based thermoplastic elastomer resin, acrylic resin, polyvinyl chloride resin, polyester resin, polyurethane resin, polyimide resin, polyamide resin, and polycarbonate resin.

In the above cleaning sheet, the member of the convex portion may contain an extender pigment as the inorganic powder.

The cleaning sheet may have a cleaning surface on both sides.

The method for producing a cleaning sheet according to the present invention is the method for producing the above-mentioned cleaning sheet,
The member of the protrusion is formed by coating.

In the above-mentioned method for producing a cleaning sheet, the cleaning sheet may have a supporting substrate, and the members of the protrusions may be formed by overlaying the supporting substrate by coating.
In the above-mentioned method for producing a cleaning sheet, the cleaning sheet may have a supporting substrate and an adhesive layer overlying the supporting substrate, and the members of the convex portions may be formed by overlaying the adhesive layer by coating.

The laminate of the present invention is in a state where the cleaning sheet is rolled up, or
The cleaning sheet is characterized in that a plurality of the above cleaning sheets are laminated in the thickness direction.

The cleaning tool of the present invention comprises the above-mentioned cleaning sheet and a sheet fixing part to which the cleaning sheet is detachably attached.
In the above-mentioned cleaning tool, any one of the above-mentioned cleaning sheets is detachably attached to the sheet fixing part. During cleaning, the sheet fixing part is operated in the same manner as a mop or floor wiper, for example, to bring the cleaning sheet attached to the sheet fixing part into sliding contact with the surface of the object to be cleaned, thereby efficiently carrying out the cleaning work.

The cleaning sheet, cleaning sheet laminate, and cleaning tool of the present invention can at least have good dirt trapping properties. The method for producing a cleaning sheet of the present invention has the effect of producing a cleaning sheet with good dirt trapping properties.

FIG. 2 is a schematic diagram of a cleaning sheet according to an embodiment, viewed from one side (the cleaning surface side). FIG. 2 is a schematic cross-sectional view of a cleaning sheet according to one embodiment, cut in the thickness direction (along the dashed line in FIG. 1 ). FIG. 2B is a schematic cross-sectional view of a cleaning sheet according to another embodiment, cut in the thickness direction in the same manner as in FIG. 2A . FIG. 1 is a perspective view showing a schematic configuration of a cleaning tool to which a cleaning sheet according to an embodiment is attached. FIG. 11 is a schematic view of a cleaning sheet according to another embodiment, viewed from one side (the cleaning side). FIG. 11 is a schematic view of a cleaning sheet according to another embodiment, as viewed from one side (the cleaning surface side). FIG. 11 is a schematic view of a cleaning sheet according to yet another embodiment, as viewed from one side (the cleaning surface side). FIG. 1 is a schematic diagram of a cleaning sheet according to a certain embodiment, viewed from one side (the cleaning side). FIG. 2 is a schematic diagram illustrating a cross section of cleaning sheets stacked in a thickness direction according to an embodiment. FIG. 1 is a schematic diagram showing measurement by the nanoindentation method. Schematic diagram of a measurement chart using the nanoindentation method.

Below, one embodiment of the cleaning sheet and cleaning tool according to the present invention will be described in detail with reference to the drawings.

<Cleaning tools>
3, the cleaning tool 100 of this embodiment includes a cleaning sheet 1, which will be described in detail later, and a sheet fixing part 120 that fixes the cleaning sheet 1. Furthermore, the cleaning tool 100 of this embodiment includes a rod-shaped grip member 110 that functions as a handle.
The sheet fixing part 120 is flat to hold the cleaning surface 10 of the cleaning sheet 1 in a flat state, and is rotatably connected to one end of the gripping member 110 via a universal joint 130. In this embodiment, the sheet fixing part 120 is flat and rectangular (oblong) when viewed from one side in the thickness direction.
The sheet fixing part 120 is configured so that, with the cleaning sheet 1 fixed, an operator brings at least a part of the cleaning surface 10 of the cleaning sheet 1 into contact with the surface of the object to be cleaned, and slides the cleaning surface 10 in either direction along the surface of the object to be cleaned.

The cleaning sheet 1 of this embodiment is attached to the sheet fixing part 120, for example, as follows. In detail, a cleaning surface 10 that is in sliding contact with the object to be cleaned and a non-cleaning surface 20 that is not in sliding contact are formed on one side of the cleaning sheet 1. The cleaning sheet 1 is overlapped on one side of the sheet fixing part 120 (a smooth surface that faces the object to be cleaned when used) so that the cleaning surface 10 of the cleaning sheet 1 faces outward. The cleaning sheet 1 is folded back at the edges of the opposing long sides of the sheet fixing part 120, and the portion forming the non-cleaning surface 20 is fixed to the other side of the sheet fixing part 120 (the surface that does not face the object to be cleaned). In this embodiment, radial slits 140 are formed in a flexible member on the other side of the sheet fixing part 120. By pushing a part of the portion forming the non-cleaning surface 20 into such radial slits 140, the cleaning sheet 1 can be detachably fixed to the sheet fixing part 120. In this way, the cleaning sheet 1 is detachably attached to the sheet fixing part 120. Note that the fixing means is not limited to this, and known fixing means such as clips can also be used. The cleaning sheet 1 may be attached to the sheet fixing part 120 with double-sided tape or the like. An adhesive layer may be superimposed on the entire or part of the back side of the cleaning sheet 1, and the adhesive layer may be attached to the sheet fixing part 120. Only one cleaning sheet 1 may be fixed to the sheet fixing part 120, or multiple cleaning sheets 1 may be fixed to the sheet fixing part 120 in a stacked state.
When the cleaning sheet 1 becomes damaged or soiled through use and needs to be replaced, it can be easily removed from the sheet fixing part 120. Then, the used cleaning sheet 1 can be replaced with a new, unused cleaning sheet.
When a plurality of cleaning sheets 1 are stacked and fixed to a sheet fixing part 120, if the outermost cleaning sheet 1 becomes soiled, the cleaning sheet 1 can be peeled off, for example, along the perforations to expose an unsoiled cleaning sheet 1.

The cleaning sheet 1 of this embodiment will be described in more detail with reference to the drawings.

<Cleaning sheet>
1 and 2A, the cleaning sheet 1 of this embodiment has a relatively thin thickness. The cleaning sheet 1 of this embodiment is formed with a cleaning surface 10 that comes into sliding contact with the surface of an object to be cleaned.
The cleaning surface 10 has projections and recesses, and is used by bringing the tips of the projections 12 into sliding contact with the object to be cleaned. The projections 12 are constituted by members 30 formed to leave a distance A in the surface direction of the cleaning surface 10. The cleaning surface 10 further has adhesive recesses 14 that have a higher adhesive strength than the members 30 and are exposed on the cleaning surface 10.
Specifically, the cleaning sheet 1 of this embodiment has a cleaning surface 10 that is in sliding contact with the surface of the object to be cleaned. The cleaning surface 10 has an uneven shape. The cleaning sheet 1 of this embodiment includes an adhesive layer 40 that constitutes at least a part of the bottom of the concave shape, and a convex part component 30 that forms a convex part and has a lower adhesive force than the adhesive layer 40. The convex part component 30 is configured to form a gap in at least one direction of the surface direction of the cleaning surface 10, and a concave shape is disposed in the gap. In the cleaning sheet 1 of this embodiment, the convex part component 30 is disposed so as to protrude from the adhesive layer 40, thereby forming a convex part 12 on the cleaning surface 10. In addition, at least a part of the adhesive layer 40 is disposed on the bottom of the concave shape, thereby forming an adhesive concave part 14. In the adhesive concave part 14, at least a part of the adhesive layer 40 is exposed to the cleaning surface 10.
The cleaning sheet 1 of this embodiment includes an adhesive layer 40 that extends in the planar direction of the cleaning surface 10 and is disposed in at least a portion of the spaces between the members 30. At least a portion of the adhesive layer 40 constitutes the adhesive recesses 14, and the proportion of the exposed area of the adhesive layer 40 on the cleaning surface 10 is 30% or more.
The ratio (H/L) of the average convex height (H: mm) from the tip of the convex portion 12 to the adhesive concave portion 14 to the average length (L: mm) of the shape of the adhesive concave portion 14 in the first direction in which the average spacing length in the above-mentioned surface direction is smallest is 15 x ^10-3 or more.

As shown in FIG. 2A , the cleaning sheet 1 of the present embodiment includes the above-mentioned member 30 that is in sliding contact with the object to be cleaned, a supporting substrate 50, and an adhesive layer 40 that is disposed between the above-mentioned member and the supporting substrate 50.
In other words, the cleaning sheet 1 of this embodiment has a support substrate 50 that faces the grip member 110 when fixed to the cleaning tool 100, an adhesive layer 40 superimposed on a portion of the surface of the support substrate 50, and the above-mentioned member 30 superimposed on the surface of the adhesive layer 40. More specifically, the adhesive layer 40 is disposed so as to cover at least a central portion of one surface of the support substrate 50, and the above-mentioned member 30 is disposed so as to superimpose on one surface of the adhesive layer 40 (the surface facing the object to be cleaned).
In addition, the number of the above-mentioned members 30 in FIG. 2A is less than that in FIG. 1 for ease of viewing.

As shown in Fig. 1 and Fig. 2A, the cleaning sheet 1 of this embodiment has a cleaning surface 10 formed on one side (the side facing outward when fixed to the sheet fixing part 120) that is in sliding contact with the surface of the object to be cleaned, such as a floor. The cleaning sheet 1 may also have a non-cleaning surface 20 as in this embodiment. In this embodiment, the cleaning surface 10 is formed by the convex parts 12 and a part of the adhesive layer 40 (adhesive concave parts 14), while the non-cleaning surface 20 is formed by the surface of the support substrate 50. The non-cleaning surface 20 may be formed by one or more release layers arranged on the surface of the support substrate 50.
1 , when the rectangular cleaning sheet 1 is viewed from one side, one cleaning surface 10 is disposed between two opposing strip-shaped non-cleaning surfaces 20. In other words, the rectangular cleaning surface 10 is disposed so as to be sandwiched between the two strip-shaped non-cleaning surfaces 20.
The cleaning surface 10 may be formed on only one side of the cleaning sheet 1 as described above, or on each of both sides.

In this embodiment, the convex portion constituent member 30 has a plurality of linear members (linear members). The cleaning surface 10 of the cleaning sheet 1 has the convex portion 12 constituted by members (convex portion constituent members 30) in which a plurality of linear members are arranged at intervals A in the surface direction. In addition, the cleaning surface 10 has the adhesive recessed portions 14 as described above.
In this embodiment, the convex portion component 30 has a plurality of linear members. The linear members are arranged so as to be in contact with the surface of the adhesive layer 40. The linear members are arranged at an interval A along one of the planar directions of the cleaning surface 10. The parallel linear members extend in the same direction as the longitudinal direction of the band-shaped non-cleaning surface 20.
The adhesive layer 40 in the adhesive recesses 14 has a higher adhesive strength than the constituent members 30 of the protrusions. At least a portion of the adhesive layer 40 is exposed to the cleaning surface 10. In this embodiment, the adhesive recesses 14 are disposed at the above-mentioned interval A, and are recessed from the tips of the protrusions 12 by the protruding height of the protrusions 12. At least a portion of the adhesive layer 40 is exposed and forms the bottom of the adhesive recesses 14.
With the above configuration, the cleaning sheet 1 is used by mainly bringing the tips of the convex portions 12 into sliding contact with the object to be cleaned. Furthermore, during sliding contact, dirt may be collected in the gap A separating the adjacent linear members. Since the adhesive recesses 14, which have a relatively high adhesive force and are recessed further than the convex portions, are disposed in the above gap A, the collected dirt can be captured by the adhesive layer 40 in the adhesive recesses 14. Moreover, even if the captured dirt is relatively heavy, the dirt can be held on the surface of the adhesive recesses 14 by the adhesive force. Therefore, the above cleaning sheet has good dirt capture properties.
Furthermore, with the above-mentioned configuration, although the adhesive layer 40 has a relatively strong adhesive force, the adhesive recesses 14 are recessed below the tips of the protrusions 12, so that the cleaning surface 10 is not significantly affected by the frictional force caused by the adhesive force of the adhesive layer 40, and mainly the tips of the protrusions 12 come into contact with and slide against the surface of the object to be cleaned. Therefore, the above-mentioned cleaning sheet 1 has good slip properties.

The static friction coefficient of the cleaning surface (against SUS304 plate) is preferably 3.00 or less, more preferably 1.50 or less, and even more preferably 1.00 or less. This allows for better slipperiness. The static friction coefficient may be 0.20 or more.
The static friction coefficient is measured in accordance with the measurement conditions described in JIS K7125:1999 (ISO8295:1995) at a temperature of 23°C.
Similarly, the coefficient of kinetic friction can be determined.
In the measurement of the coefficient of friction, a SUS304 steel plate (100 x 200 mm) used in JIS Z0237:2009 is used. On this SUS304 steel plate, a sheet of 80 x 160 mm size cut out from a cleaning sheet is placed so that the cleaning surface is in contact with the SUS steel plate surface, and a sliding piece with a contact area of 40 cm ² (one side length 63 mm) is placed. The total mass of the sliding piece is adjusted to 200 g. The speed in the friction coefficient measurement is 100 mm/min, and the static friction coefficient and the dynamic friction coefficient, which are the maximum force over a measurement distance of 60 mm, are calculated. The average value of five measurements is recorded. In addition, when measuring the static friction coefficient, the auxiliary plate is connected to the load cell through a spring, and when measuring the dynamic friction coefficient, a spring is not used.
The static and dynamic friction coefficients can be reduced, for example, by increasing the ratio (H/L) described below, where the ratio (H/L) is the ratio (H: mm) of the average convex height from the tip of the convex portion 12 to the adhesive concave portion 14 to the average length (L: mm) of the shape of the adhesive concave portion in the first direction in which the average length of the interval in the surface direction of the cleaning surface is minimum.

(Members Constituting the Convex Portion)
In this embodiment, the member 30 constituting the convex portion has a plurality of linear members extending in parallel. A portion of the adhesive layer 40 is exposed in the space A between adjacent linear members. This allows dust that has gathered near the adhesive recess 14 as the adhesive contacts with the surface to be captured by the adhesive layer 40, and the dust can be kept captured by the adhesive force of the adhesive recess 14. This provides excellent dust capture properties.

The width of the line member is usually 0.01 mm or more. The width of the line member is more preferably 0.02 mm or more, even more preferably 0.03 mm or more, and particularly preferably 0.1 mm or more. The width of the line member may be 20 mm or less, 10 mm or less, 5 mm or less, or 1 mm or less. When the convex portion is composed of multiple parallel line members, or when the convex portion is composed of multiple intersecting line members, it is preferable that the width of the line member is in the above range.

The hardness of the member 30 constituting the convex portion is measured by a nanoindentation method. The hardness is preferably 0.4 MPa or more. By having the hardness of 0.4 MPa or more, the frictional force between the convex portion 12 that slides against the surface of the object to be cleaned and the surface of the object to be cleaned during sliding contact can be made relatively small. Therefore, the cleaning sheet 1 having such a member with a relatively high rigidity on the cleaning surface 10 has good slip properties. In addition, by forming the convex portion 12 with such a member with a relatively high rigidity, the member is prevented from being worn due to sliding contact during cleaning, and the cleaning sheet 1 can exhibit good durability.
The hardness of the component 30 of the convex portion is preferably 0.4 MPa or more, more preferably 1.5 MPa or more, even more preferably 3.0 MPa or more, particularly preferably 5.0 MPa or more, and most preferably 10.0 MPa or more. The upper limit of the hardness of the component is not particularly limited, and the hardness of the component may be 200 MPa or less. In order to impart appropriate deformability to the component 30 and to suppress the occurrence of scratches on the surface of the object to be cleaned by the convex portion 12, the hardness of the component 30 is preferably 100 MPa or less, more preferably 70 MPa or less, and particularly preferably 50 MPa or less.

The hardness of the above member 30 by the nanoindentation method is measured in accordance with ISO 14577. Specifically, it is measured using a measuring device "TI950 TriboIndenter" (manufactured by Hysitron, Inc.). More specifically, it is calculated by dividing the "load when the indenter is pressed deepest (maximum load Pmax)" by the "area where the indenter and the measurement sample contact (contact projected area B)". A Berkovich type diamond indenter (triangular pyramid indenter) is used as the indenter, and a single indentation measurement is performed. In order to prevent the measured value from being affected by anything other than the above member 30, it is desirable that the thickness of the above member 30 at the time of measurement is at least 50 μm. The indenter pressing speed is 500 nm/sec, and the pull-out speed is 500 nm/sec. The indenter pressing depth is 5 μm. The measurement is performed at 25° C. At least three measurements are performed to obtain an average value. The examples described below are also measured in a similar manner.

The elastic modulus of the member 30 measured by the nanoindentation method may be, for example, 4.5 MPa to 1000 MPa, 4.5 MPa to 500 MPa, or 4.5 MPa to 200 MPa. The elastic modulus is calculated based on the results of measurement in the same manner as the measurement of the hardness of the member 30. However, the elastic modulus is calculated by the following formula using the "slope of the tangent at the maximum load of the unloading curve (tangent stiffness S = dP/dh)" and the "area where the indenter and the measurement sample contact (contact projected area B)". The indentation depth of the indenter is 5 μm.
The slope of the tangent to the unloading curve at the maximum load is calculated by the following method. It is assumed that the power law of the following formula (1) holds true for the unloading curve. In formula (1), A, hf, and m are constants determined by applying the least squares method to the unloading curve. Formula (1) is differentiated to obtain formula (2). From formula (2), the slope of the tangent to the unloading curve at the maximum load is calculated. Note that A, hf, and m are calculated by applying the least squares method to the unloading curve between 20% and 95% of the indenter pressing load of the unloading curve.

The slope of the load curve when the above member 30 is measured by the nanoindentation method is preferably 1 [μN/nm] or more and 5 [μN/nm] or less. The slope of the load curve is calculated based on the results of a measurement similar to that of the hardness measurement of the above member 30. The slope of the load curve when the indenter's pressing depth is between 50% and 85% is adopted. In the above measurement, since the indenter's pressing depth is 5 μm, the slope of the load curve when the displacement is between 2.5 μm and 4.25 μm is adopted.

In order to increase the hardness, modulus of elasticity, and slope of the load curve of the above-mentioned member 30 by the nanoindentation method, for example, a larger amount of resin material with a higher modulus of elasticity is blended into the member 30. On the other hand, in order to decrease the hardness, modulus of elasticity, and slope of the load curve of the above-mentioned member 30, for example, a larger amount of plasticizer or resin material with a lower modulus of elasticity is blended into the member 30.

The minimum load of the load curve when the member 30 is measured by the nanoindentation method is preferably −0.40 μN or more and 0 μN or less, and more preferably −0.10 μN or more and 0 μN or less. By having the minimum load of the load curve be −0.10 μN or more and 0 μN or less, the member 30 has almost no wettability, and therefore exhibits better slip properties.
The minimum load of the unloading curve when the member 30 is measured by the nanoindentation method is preferably −1.50 μN or more and 0 μN or less, and more preferably −0.10 μN or more and 0 μN or less. When the minimum load of the unloading curve is −0.10 μN or more and 0 μN or less, the adhesive force (adhesive force) of the member 30 is almost eliminated, and better slip properties are exhibited.
In order to increase the minimum load of the above-mentioned load curve and the minimum load of the unload curve by the nanoindentation method, for example, a hard material with poor adhesion is blended into the member 30. On the other hand, in order to decrease the minimum load of the above-mentioned load curve and the minimum load of the unload curve, for example, a soft material with good adhesion is blended into the member 30.

The convex portion component 30 is made of a material having the above-mentioned hardness. The convex portion component 30 is made of a resin containing at least a resin material, for example. As such a resin material, for example, one or more of the following are used: polyolefin resin such as polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymer; ethylene-vinyl acetate copolymer resin (EVA); styrene-based thermoplastic elastomer resin (styrene-based block copolymer) such as SIS and SEBS; acrylic resin; polyvinyl chloride resin, CEBC resin; polyester such as PET; polyurethane resin; polyimide resin; polyamide resin; and polycarbonate resin. The convex portion component 30 is not particularly limited, but is preferably formed of a material containing one or more resins selected from the group consisting of polyolefin resin, polyester resin, ethylene-vinyl acetate copolymer resin (EVA), styrene-based thermoplastic elastomer resin such as SIS and SEBS; polyolefin-based elastomer resin; polyurethane-based elastomer resin; acrylic elastomer resin; acrylic resin; and polyamide resin as the main component. The convex portion constituent member 30 preferably contains any one of these resins in an amount of more than 10 mass %, and the convex portion constituent member 30 preferably contains the above-mentioned resin material in an amount of 30 mass % or more.
Among the above resin materials, at least one selected from the group consisting of polyolefin resin, ethylene-vinyl acetate copolymer resin (EVA), the above-mentioned styrene-based thermoplastic elastomer resin, acrylic resin, and polyamide resin is preferred. In other words, the convex portion component 30 preferably contains at least one selected from the group consisting of polyolefin, ethylene-vinyl acetate copolymer resin (EVA), the above-mentioned styrene-based thermoplastic elastomer resin, acrylic resin, and polyamide resin. Particularly preferably, the convex portion component 30 contains at least one resin selected from the group consisting of polyolefin resin, ethylene-vinyl acetate copolymer resin (EVA), the above-mentioned styrene-based thermoplastic elastomer resin, and acrylic resin.
By including the preferred resin material as described above in the convex portion constituent member 30, damage to the surface of the object to be cleaned due to sliding contact is suppressed. In addition, by including the preferred resin material as described above in the convex portion constituent member 30, good slipperiness and good durability (strength) can be more fully exhibited.

The convex portion component 30 may contain at least one of wax, hardened resin, and inorganic powder in addition to the above resin material in order to have a higher elastic modulus. It is particularly preferable that the convex portion component 30 contains wax in order to have better slipperiness. It is preferable that the convex portion component 30 contains an extender pigment as inorganic powder. By the convex portion component 30 containing wax and an extender pigment as inorganic powder in addition to a resin material, the slipperiness of the convex portion component 30 itself is improved, the frictional force of the convex portion component 30 itself is reduced, and the slipperiness of the cleaning sheet 1 is significantly improved.

A wax (solid wax) is a wax that is solid at room temperature (20°C) but changes to a paste or liquid state at a temperature higher than the melting point of the wax (for example, a temperature 2 to 3 degrees higher than the melting point). The melting point can be measured using a commercially available melting point measuring device or a differential scanning calorimeter (DSC).
The melting point of the wax is usually from 50° C. to 130° C., and preferably 80° C. or higher.
Since wax is hard at room temperature, the convex component 30 containing wax has a relatively high hardness or elastic modulus at room temperature.
In contrast, at a temperature slightly higher than the melting point of the wax, the wax rapidly melts and has a lower viscosity than the resin material. Therefore, the convex component 30 containing wax has good processability in hot melt coating. In addition, the convex component 30 containing wax in addition to the resin material has the advantage of being easily cut because the stretchability caused by the resin material is suppressed. Therefore, the cleaning sheet 1 can have tape cuttability.

The hardness of the wax, expressed in terms of the penetration index, is usually from 0.1 to 60. The penetration index of the wax is preferably 50 or less, more preferably 35 or less, even more preferably 30 or less, still more preferably 15 or less, and particularly preferably 10 or less. The penetration index of the wax may be 1 or more.
The above-mentioned penetration is a value measured according to the Japanese Industrial Standards (JIS K2235 2009 5.4 Penetration Test Method) under the following measurement conditions: temperature 25° C., load 100 g, and time 5 seconds.

Examples of the wax include hydrocarbon waxes and non-hydrocarbon waxes.
Examples of the hydrocarbon wax that can be used include petroleum mineral waxes such as paraffin wax, ceresin wax, and microcrystalline wax, as well as synthetic waxes such as polyethylene wax (low molecular weight polyethylene), polypropylene wax (low molecular weight polypropylene), and Fischer-Tropsch wax.
Examples of non-hydrocarbon waxes that can be used include natural waxes such as castor wax, carnauba wax, Japan wax, Japanese laurel wax, beeswax, montan wax, candelilla wax, and rice wax, and synthetic waxes such as diheptadecyl ketone, dipentadecyl ketone, diundecyl ketone, and ditridecyl ketone.
The wax is preferably a hydrocarbon wax.

Specific examples of commercially available waxes are listed below.
Examples of such waxes include microcrystalline waxes manufactured by Nippon Seiro Co., Ltd., which are trade names of Hi-Mic-1045 (melting point 72° C., needle penetration 37), Hi-Mic-1070 (melting point 80° C., needle penetration 20), Hi-Mic-2095 (melting point 101° C., needle penetration 8), Hi-Mic-1090 (melting point 88° C., needle penetration 6), and Hi-Mic-1080 (melting point 84° C., needle penetration 12).
Further examples include Fischer-Tropsch waxes manufactured by Nippon Seiro Co., Ltd., such as waxes with trade names of FT115 (melting point 113° C., penetration 1), SX105 (melting point 102° C., penetration 1), FT-0165 (melting point 73° C., penetration 5), and FT-0070 (melting point 72° C., penetration 11).
Further examples of waxes include Fischer-Tropsch waxes manufactured by Sasol, such as Sasolwax H1 (melting point 112°C, penetration 1) and Sasolwax C80 (melting point 88°C, penetration 4 to 9).
Further examples include low molecular weight polyolefin waxes manufactured by Sanyo Chemical Industries, Ltd., such as waxes under the trade names SANWAX 171-P (penetration degree 5), SANWAX 151-P (penetration degree 4), SANWAX 131-P (penetration degree 4), SANWAX 161-P (penetration degree 2), SANWAX E-310 (penetration degree 5), SANWAX E-330 (penetration degree 4) and SANWAX E-250P (penetration degree 5).
Other examples include polyethylene waxes manufactured by Yasuhara Chemical Co., Ltd. under the trade name Neowax (melting point 110°C, penetration 5); polyethylene waxes manufactured by Mitsui Chemicals, Inc. under the trade names Hiwax HP10A (melting point 116°C, penetration 2), Hiwax 210P (melting point 114°C, penetration 4), Hiwax 210MP (melting point 112°C, penetration 3), Hiwax 4202E (melting point 100°C, penetration 5), Hiwax NL100 (melting point 103°C, penetration 3), and Hiwax NP056 (melting point 124°C, penetration 2).

The convex portion component 30 preferably contains 5 parts by mass or more of wax per 100 parts by mass of the resin material, more preferably 10 parts by mass or more, even more preferably 50 parts by mass or more, and particularly preferably 100 parts by mass or more. The convex portion component 30 may also contain 300 parts by mass or less of wax per 100 parts by mass of the resin material, 250 parts by mass or less, or 200 parts by mass or less. The convex portion component 30 may also contain only wax.

The convex portion component 30 preferably contains 1 part by mass or more of the inorganic powder relative to 100 parts by mass of the resin material, more preferably 5 parts by mass or more, even more preferably 50 parts by mass or more, and particularly preferably 100 parts by mass or more. Also, the convex portion component 30 may contain 400 parts by mass or less, 250 parts by mass or less, or 200 parts by mass or less of the inorganic powder relative to 100 parts by mass of the resin material.
Examples of the inorganic powder include an extender pigment, a color pigment, a functional particle, etc. Examples of the extender pigment include silica, titanium oxide, zinc oxide, magnesium carbonate, calcium carbonate, talc, etc.
The convex portion constituent member 30 may contain an organic pigment or an organic dye in addition to the inorganic powder.

When the component 30 of the convex portion contains the resin material, the extender pigment (inorganic powder), and the wax, the extender pigment may be contained in an amount of 1 part by mass to 300 parts by mass per 100 parts by mass of the resin material, and the wax may be contained in an amount of 1 part by mass to 300 parts by mass per 100 parts by mass of the resin material.

The convex component 30 may include a cured resin. Examples of the cured resin include uncured resin that is cured by energy rays, such as ultraviolet rays or electron beams. Specific examples of the cured resin include cured ultraviolet-curable (UV-curable) resin and cured electron-beam-curable (EB-curable) resin. The cured resin may be a two-liquid reactive crosslinking type cured product.
For example, a composition for the convex portion constituent member 30 containing a UV-curable resin is applied and then cured by UV irradiation, thereby making it possible to prepare the convex portion constituent member 30 having sufficient hardness and elasticity. This also makes it possible to obtain a cleaning sheet 1 with good slipperiness.

The convex portion component 30 preferably contains 10 parts by mass or more, and more preferably 50 parts by mass or more, of cured resin per 100 parts by mass of the resin material (thermoplastic resin). The convex portion component 30 may also contain 400 parts by mass or less, or 200 parts by mass or less, of cured resin per 100 parts by mass of the resin material. The convex portion component 30 may also contain only cured resin.

The cleaning sheet 1 of this embodiment may include a fiber aggregate, generally called a woven fabric or nonwoven fabric, in the convex component 30 or the adhesive layer 40. In other words, the convex component 30 and the adhesive layer 40 may be at least partially composed of a fiber aggregate. Note that a fiber aggregate generally refers to an aggregate of fibers with a thickness of less than 0.03 mm. The fiber aggregate is made, for example, by a melt-blowing method.

The basis weight (grammage) of the component 30 of the convex portion, in other words, the mass of the component 30 per unit area of the cleaning surface 10, is appropriately set in consideration of the slipperiness and the like. Such basis weight is preferably 5 g/m ² or more, more preferably 10 g/m ² or more, even more preferably 20 g/m ² or more, particularly preferably 30 g/m ² or more, more particularly preferably 40 g/m ² or more, and most preferably 50 g/m ² or more. If the material of the component 30 of the convex portion is the same and the arrangement of the multiple linear members is the same, when such basis weight is increased, the protruding height of the convex portion 12 increases or the exposure rate of the adhesive layer 40 decreases. Therefore, a larger basis weight can reduce the average adhesive force on the entire cleaning surface 10. This makes it easier to exhibit better slipperiness.
On the other hand, the above-mentioned basis weight is preferably 500 g/m2 ^or less, more preferably 400 g/m2 or less, even more preferably 300 g/m2 ^{or less} , and particularly preferably 200 g/m2 ^{or less} , in order to achieve better dust capture properties.

The average protruding height of the protrusions 12 (average protruding height H) is set taking into consideration at least the ability to capture dirt. The average protruding height of the protrusions 12 (average protruding height H) is appropriately set taking into consideration slipperiness and durability as well. The average protruding height of the protrusions 12 is the average of the heights from the tips of the protrusions 12 to the adhesive recesses 14. The average protruding height of the protrusions 12 (H: mm) is measured by observing the cross section with a surface roughness meter or a microscope.
The average protruding height (average protruding height H) of the protrusions 12 is preferably 1000×10 −3 mm or less, more preferably 500×10 ⁻³ mm or less, in order to achieve better dust capture. In some cases, the average protruding height (average protruding height H) may be 300× ^{10 −3 mm} or less, or may be 200×10 ⁻³ mm or less.
The average protruding height (average protruding height H) of the protrusions 12 may be 30×10 ⁻³ mm or more, 50×10 ⁻³ mm or more, or 70×10 ⁻³ mm or more. In some cases, such average protruding height (average protruding height H) may be 100×10 ⁻³ mm or more, or 300×10 ⁻³ mm or more.
By setting the average protruding height (average protruding height H) of the protruding portions 12 within the above-mentioned preferred range, the frictional force during sliding contact is suppressed, the slipperiness is improved, and the cleaning surface 10 can be more smoothly slid against the surface of the object to be cleaned. In addition, since the exposed surface of the adhesive layer 40 is positioned at a position recessed from the tip of the protruding portion by the above-mentioned numerical value or more, unintended sticking of the cleaning surface 10 to the object to be cleaned can be further suppressed.
For example, when the supporting substrate 50 is made of paper with low cushioning properties, or when it is made of nonwoven fabric or foam with high cushioning properties, an appropriate average protruding height of the convex portions 12 can be set.

The tip of the protrusion 12 preferably has a tapered shape, and more preferably has a rounded shape. In other words, the tip preferably has a shape in which the cross-sectional area in the surface direction of the cleaning surface 10 decreases toward the tip. When the tip has a tapered shape, the tip does not have to be sharp, and may be flat.
By tapering the tip of the protrusion 12, it is possible to reduce the frictional force when the protrusion 12 slides against the object to be cleaned, thereby achieving better sliding properties.

(Adhesive recess)
In this embodiment, the adhesive recess 14 is a part of the adhesive layer 40 described below. In other words, a part of the adhesive layer 40 constitutes the adhesive recess 14. In further other words, a part of the surface of the adhesive layer 40 is exposed to constitute the adhesive recess 14. By arranging the linear members of the member 30 on the surface of the adhesive layer 40 with a distance A therebetween, a part of the surface of the adhesive layer 40 is exposed at the distance A, and the remaining part of the surface of the adhesive layer 40 is covered by the member 30. It should be noted that, as described below, the cleaning sheet of the present invention is not limited to such a configuration.

In this embodiment, as shown in FIG. 1, the adhesive layer 40 extends continuously in the surface direction of the cleaning surface 10. The shape of each adhesive recess 14 when the cleaning surface 10 is viewed in the thickness direction of the cleaning sheet 1 is not particularly limited. The adhesive recess 14 does not have to have a fixed shape. On the other hand, the shape of each adhesive recess may be a polygon such as a square or a triangle, a circle such as a perfect circle or an ellipse, or another irregular shape.

The ratio of the exposed area of the adhesive layer 40 on the cleaning surface 10 (hereinafter also simply referred to as the exposure rate) is 30% or more. Such an exposure rate is preferably 40% or more, more preferably greater than 50%, and even more preferably 60% or more.
When the above-mentioned exposure rate is greater than 40%, dirt can be more sufficiently captured by the adhesive recesses 14. Therefore, the above-mentioned cleaning sheet 1 having good slipperiness can also have good dirt capturing properties.
The above-mentioned exposure rate may be 95% or less, or may be 90% or less. By setting the upper limit of the exposure rate to 95% or less, better slip properties can be exhibited.
The above-mentioned exposure rate is preferably larger in that it can suppress clogging caused by dirt and capture dirt more sufficiently. However, as described in the above-mentioned Patent Document 1, as the exposure rate increases, the adhesive layer 40 is more likely to come into contact with the object to be cleaned. This may cause glue residue or make it difficult to operate during cleaning. In the above-mentioned cleaning sheet 1, by selecting the material of the convex portion component 30 or setting the ratio (H/L) described later, it is possible to have good slip properties even when the exposure rate is 30% or more.
For example, the cleaning sheet 1 can be manufactured in a state in which the supporting substrate 50 and the constituent members 30 of the convex portions are directly overlapped by bonding the supporting substrate 50 and the constituent members 30 of the convex portions together, or by coating (described later) the supporting substrate 50 with the constituent members 30 of the convex portions. When manufacturing the cleaning sheet 1 by a coating method, the above-mentioned exposure rate can be appropriately set depending on the material of the constituent members 30 of the convex portions and the member thickness in the thickness direction of the supporting substrate 50, so as to obtain good slip properties and dirt capture properties.
In the manufacturing method of punching a fiber sheet to form circular holes and attaching an adhesive sheet to the fiber sheet as in the above-mentioned Patent Document 1, the strength of the fiber sheet is relatively low, so that the size and number of holes are limited, and the exposure rate may be limited. On the other hand, by preparing the convex component 30 by coating, the convex component 30 can be directly formed on the support substrate 50 or the adhesive layer 40, so that the exposure rate can be freely set. In addition, by preparing the convex component 30 by coating, it is possible to easily prepare the convex component 30 of a convex other than a continuous pattern shape while having holes as in Patent Document 1. For example, it is possible to easily form the convex component 30 of any discontinuous pattern shape.

The exposure rate is the ratio of the total exposed area of the adhesive layer 40 to the total area of the cleaning surface 10. The total area of the cleaning surface 10 is the larger of the area of the portion where the component 30 of the convex portion extends in the surface direction or the area of the adhesive layer 40. When the area of the adhesive layer 40 is used as the total area of the cleaning surface 10, even if the adhesive layer 40 does not extend continuously in the surface direction, the area of the region inside from the adhesive composition arranged on the outermost side in the surface direction is taken as the area of the adhesive layer 40.
The exposure rate can be calculated from the total exposed area of the adhesive layer 40 per unit area of the cleaning surface 10. The exposure rate can be calculated, for example, as follows. Specifically, a photograph of the appearance of the member 30 is taken, the photograph is enlarged on copy paper or the like, and the exposed shape of the adhesive layer 40 is cut out with scissors or the like. Then, the mass of the paper cut out in the unit area is divided by the mass of the paper per unit area to accurately calculate the exposure rate. In addition, the exposure rate can be accurately calculated by image processing from an image taken with a microscope or the like. In the examples described later, the exposure rate is measured by these methods.
In measuring the exposure rate, the range of the cleaning surface 10 to be measured is preferably the entire range, but if the arrangement pattern of the members is regular, it may be an arbitrarily selected square area, for example, 3 cm x 3 cm. If the arrangement pattern of the members on the cleaning surface 10 is not regular and differs partially, the exposure rate of the entire cleaning surface 10 is measured.
In addition, if the supporting substrate 50 is exposed on the cleaning surface 10, the area of the exposed portion of the supporting substrate 50 is not included in the total exposed area of the adhesive layer 40 when calculating the exposure rate. For example, if the supporting substrate 50 and the adhesive layer 40 are exposed between a plurality of linear members of the component 30 of the convex portion, only the area of the exposed portion of the adhesive layer 40 is included in the total exposed area of the adhesive layer 40, and the area of the exposed portion of the supporting substrate 50 is not included in the total exposed area of the adhesive layer 40.

Generally, there exists a first direction in which the average length of the above-mentioned intervals is minimum in the surface direction of the cleaning surface 10. For example, in this embodiment, the first direction is a direction perpendicular to the extending direction of the linear members 30 of the convex portion.
In the first direction, the average length (L: mm) of the shape of the adhesive recess 14 at the interval A formed by the component 30 of the convex portion, in other words, the average length (L: mm) of the shape of each adhesive recess 14 in the first direction of the cleaning surface 10, is appropriately set in consideration of the slipperiness and dirt capture. For example, the average length of the shape of the adhesive recess 14 is preferably 10 mm or less, more preferably 8 mm or less, even more preferably 5 mm or less, and particularly preferably 3 mm or less, in terms of exhibiting better slipperiness. By having the average length of the shape of the adhesive recess 14 be 10 mm or less, the average adhesive force on the entire cleaning surface 10 becomes smaller, so that it is possible to prevent the unused cleaning sheet from sticking to the packaging material or other cleaning sheets. In addition, the average length of the shape of the adhesive recess 14 is preferably 0.3 mm or more, more preferably 0.5 mm or more, even more preferably 0.8 mm or more, and particularly preferably 1.0 mm or more, in terms of exhibiting better dirt capture.

The average length of the shape of the adhesive recesses 14 in the first direction is measured as follows: In principle, a virtual line for determining the first direction is set so as to pass through the center of the cleaning surface where the adhesive recesses are present.
In this embodiment, as shown in Fig. 1, a plurality of linear members extend in parallel toward one direction in the surface direction of the cleaning surface 10. Since the average length of the above-mentioned interval is smallest in the direction in which the virtual straight line is perpendicular to the linear members, the first direction is the direction perpendicular to the linear members (see the linear dashed line in Fig. 1). In this embodiment, as shown in Fig. 1, the component member 30 of the convex portion is composed of a plurality of linear members arranged in a straight line at approximately the same interval A in the first direction, and the distance between adjacent linear members is measured at at least 10 points and the measured values are averaged to obtain the above-mentioned average length. The examples described later are also measured in a similar manner.
When the shape of each adhesive recess 14 is circular as shown in Figure 4, or when the shape of each adhesive recess 14 is rectangular as shown in Figure 5, the first direction is determined in the same manner as described above, and the average length of the shape of the adhesive recess 14 is found.
On the other hand, when it is difficult to determine the first direction as one direction, the above average length can be obtained as follows. For example, in one example of the convex part component 30, as shown in FIG. 6, short line members are intermittently arranged at intervals in the longitudinal direction, and the short line members are arranged at approximately the same intervals in the direction perpendicular to the longitudinal direction. In addition, as shown in FIG. 7, another example of the convex part component 30 is composed of small members that draw letters. In such a case, the diameter of the imaginary maximum circle (true circle) inscribed in the member in the gap between the members is regarded as the length of the shape of each adhesive recess 14 (see the circle drawn by the dashed line). At this time, at least three arbitrarily selected square parts of 3 cm x 3 cm are selected, and the length of the shape of each adhesive recess 14 at least 10 points in each square part is measured, and the above average length is obtained by averaging the measured values.

In the cleaning surface 10, the ratio (H/L) of the average convex height (H: mm) from the tip of the convex portion 12 to the adhesive concave portion 14 to the average length (L: mm) of the shape of the adhesive concave portion in the first direction in which the average length of the above-mentioned interval in the surface direction of the cleaning surface is the smallest is 15×10 ⁻³ or more. Such a ratio (H/L) is preferably 20×10 ⁻³ or more, more preferably 25×10 ⁻³ or more, even more preferably 30×10 ⁻³ or more, particularly preferably 40×10 ⁻³ or more, and even more particularly preferably 45×10 ⁻³ or more. The above ratio (H/L) may be 60×10 ⁻³ or more, or may be 70×10 ⁻³ or more in some cases.
By making the ratio (H/L) 20×10 ⁻³ or more, the average convex height relative to the average length of the shape of each adhesive recess 14 becomes relatively large, so that the adhesive recess 14 is more prevented from contacting the surface of the object to be cleaned. Therefore, the frictional force on the entire cleaning surface 10 becomes smaller, and better slipperiness is exhibited. Also, as described above, unintended sticking of the cleaning surface 10 to the object to be cleaned can be more effectively suppressed.
The above ratio (H/L) is preferably 600×10 ⁻³ or less, more preferably 300×10 ⁻³ or less, even more preferably 150×10 ⁻³ or less, particularly preferably 100×10 ⁻³ or less, and even more particularly preferably 80×10 ⁻³ or less.
When the above ratio (H/L) is 600×10 ⁻³ or less, the adhesive force on the cleaning surface 10 is more easily exerted, and better dust trapping properties are exhibited.

(Adhesive layer)
In this embodiment, the adhesive layer 40 extends in the planar direction of the cleaning surface 10 and is disposed on the rear surface side of the convex portion constituent member 30. The adhesive layer 40 is formed in a layer shape using, for example, an adhesive composition.
The cleaning sheet 1 of this embodiment can be produced relatively easily because the cleaning surface 10 can be formed by simply arranging the convex component 30 on the surface of the adhesive layer 40 .
Furthermore, when the cleaning surface 10 of the cleaning sheet 1 is used to clean an object to be cleaned, the tips of the convex portions 12 are pressed against and rub against the surface of the object to be cleaned, and the convex portions 12 may penetrate slightly into the adhesive layer 40 while being supported by the adhesive layer 40. This causes the protruding height (convex portion height) of the convex portions 12 to be slightly lower, and the adhesive concave portions 14, which are recessed further than the convex portions 12, to be slightly closer to the surface of the object to be cleaned. The closer the adhesive concave portions 14 are to the surface of the object to be cleaned, the more reliably the adhesive concave portions 14 can capture dirt.

The adhesive composition forming the adhesive layer 40 includes, for example, an adhesive such as an acrylic adhesive, a rubber adhesive, a polyester adhesive, a urethane adhesive, a polyether adhesive, or a silicone adhesive. The adhesive composition may further include a tackifier resin and a plasticizer such as process oil. The type and mixing ratio of each component are set according to the application of the cleaning sheet 1 so as to obtain the desired adhesive performance.
For example, a rubber-based adhesive is an adhesive that contains a rubber-based polymer as a base polymer. The same applies to other adhesives.
The base polymer of the adhesive is the polymer component with the highest mixing ratio in the adhesive. The adhesive may contain 50% by mass or more, 70% by mass or more, or 90% by mass or more of the base polymer on a solid content basis. The adhesive may contain only the base polymer, for example, 99% by mass or less of the base polymer. In terms of exhibiting better adhesive performance and having a relatively high ratio of performance to raw material cost, the adhesive is preferably a rubber-based adhesive or an acrylic-based adhesive.

The acrylic adhesive contains an acrylic polymer as a base polymer. The acrylic polymer refers to a polymer whose main monomer component is an acrylic monomer. The acrylic monomer is a monomer having at least one (meth)acryloyl group in one molecule. The main monomer component is a component that occupies 50% by mass or more of the total amount of the monomer components that constitute the acrylic polymer. 70% by mass or more of the monomer components that constitute the acrylic polymer may be acrylic monomers, or 90% by mass or more of the monomer components that constitute the acrylic polymer may be acrylic monomers. The acrylic polymer may be a homopolymer obtained by radical polymerization, or a copolymer obtained by random copolymerization. The acrylic polymer may be a thermoplastic (typically hot melt type) block copolymer. In this specification, the (meth)acryloyl group refers collectively to an acryloyl group and a methacryloyl group. Similarly, in this specification, the (meth)acrylate refers collectively to an acrylate and a methacrylate.

Examples of rubber-based pressure-sensitive adhesives include pressure-sensitive adhesives containing, as a base polymer, one or more of rubber-based polymers such as natural rubber polymers such as natural rubber and modified products thereof, isoprene rubber, chloroprene rubber, styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene/butylene-styrene block copolymer (SEBS), crystalline polyolefin-ethylene/butylene-crystalline polyolefin block copolymer (CEBC), and styrene-ethylene/butylene-crystalline polyolefin block copolymer (SEBC).
As the rubber-based adhesive, an adhesive containing SIS as a base polymer (SIS-based adhesive) is preferable.

Examples of the tackifier resin include various types of tackifier resins such as general rosin-based, terpene-based, hydrocarbon-based, epoxy-based, polyamide-based, elastomer-based, phenol-based, and ketone-based resins. These can be used alone or in appropriate combination of two or more. The amount of tackifier resin to be blended per 100 parts by mass of base polymer is not particularly limited, but may be, for example, 50 parts by mass or more and 200 parts by mass or less, and preferably 80 parts by mass or more and 150 parts by mass or less.

Examples of the plasticizer include process oils, acrylic oligomers, phthalate ester plasticizers such as dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, and dibutyl phthalate, adipate ester plasticizers such as dioctyl adipate and diisononyl adipate, trimellitic acid esters such as trioctyl trimellitate, sebacic acid esters, epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil, epoxidized fatty acid alkyl esters such as epoxidized fatty acid octyl esters, cyclic fatty acid esters and derivatives thereof such as sorbitan monolaurate, sorbitan monostearate, sorbitan monooleate, sorbitan trioleate, and ethylene oxide adducts thereof. As the plasticizer, one of these can be used alone or two or more can be used in appropriate combination.
In the pressure-sensitive adhesive composition, the amount of plasticizer to be blended per 100 parts by mass of the base polymer is not particularly limited, but may be, for example, 50 parts by mass or more and 200 parts by mass or less, and preferably 90 parts by mass or more and 150 parts by mass or less.
Examples of the process oil include general paraffin-based, naphthenic, and aromatic process oils.

The adhesive composition (e.g., a composition containing an SIS-based adhesive) may further contain various additives such as antiaging agents, antioxidants, UV absorbers, light stabilizers, antistatic agents, lubricants, colorants (pigments, dyes, etc.). The types and amounts of these additives may be the same as those typically used in the field of general adhesives.

Various types of adhesive compositions are used to prepare the adhesive layer 40. For example, a hot melt type composition that is heated and melted, then cooled and solidified to form the adhesive layer 40, a curing type composition that contains a curing agent as necessary, an energy ray radiation curing type composition that is cured by irradiation with energy rays such as ultraviolet rays (UV) or electron beams (EB), a water dispersion type (typically an emulsion type) type composition in which the adhesive component is dispersed in water, a solvent type composition in which the adhesive component is dissolved in an organic solvent, etc. are used. From the viewpoint of good productivity and reduced environmental load, a hot melt type adhesive composition is preferably used to prepare the adhesive layer 40.

The probe tack of the adhesive layer 40 measured by a probe tack method is preferably 1.0 kN/m ² or more and 500.0 kN/m ² or less.
The probe tack of the adhesive layer 40 is 1.0 kN/ ^m2 or more and 500.0 kN/m2 ^or less, and further, as described above, the hardness of the component 30 of the convex portion is 0.4 MPa or more, thereby enabling the material to exhibit good slip properties while also exhibiting good dirt capture properties.

The probe tack measurement value of the adhesive layer 40 measured by the probe tack method is more preferably 250.0 kN/m2 or ^less , and even more preferably 150.0 kN/m2 or ^less .
By having the probe tack of the adhesive layer 40 be 250.0 kN/ ^m2 or less, even if the adhesive recesses 14 come into contact with the surface of the object to be cleaned, the cleaning surface 10 moves along the surface of the object to be cleaned in sliding contact, so that the adhesive recesses 14 can be relatively easily separated from the surface of the object to be cleaned. Therefore, the cleaning surface 10 slides better against the surface of the object to be cleaned. Therefore, the above-mentioned cleaning sheet 1 has better slipperiness.
The probe tack measurement of the adhesive layer 40 may be 5.0 kN/ ^m2 or more, 10.0 kN/ ^m2 or more, 25.0 kN/ ^m2 or more, or 50.0 kN/ ^m2 or more.
In order to increase the measured probe tack value of the adhesive layer 40, for example, an appropriate amount of a tackifier resin or plasticizer is blended into the adhesive layer 40. On the other hand, in order to decrease the measured probe tack value of the adhesive layer 40, for example, the content of the tackifier resin or plasticizer in the adhesive layer 40 is reduced.

The probe tack of the adhesive layer 40 is measured using a probe tack tester. At least 10 measurements are performed, and the average of the measured values is taken as the probe tack value. The detailed test conditions are as follows: a circular stainless steel probe (diameter: 5 mm) is brought into contact with the adhesive surface of the adhesive layer 40 for 1 second while applying a constant load (50 gf/5 mmφ), and the force required to pull the probe 5 mm vertically away from the adhesive surface is calculated, and this is taken as the probe tack (adhesive strength) value of the adhesive layer. The measurement is performed with the adhesive layer 40 overlapping the support substrate 50. The contact speed (pressing speed) of the probe is 120 mm/min, and the peeling speed is 600 mm/min. The measurement is performed in an environment of 23°C and 50% RH.

The adhesive strength of the adhesive layer 40 is appropriately set, taking into consideration the slipperiness and dirt trapping ability of the cleaning sheet 1. The adhesive strength of the adhesive layer 40 is measured by peel strength as described below.
The 180-degree peel strength of the adhesive layer 40 is preferably 0.5 N/25 mm or more, more preferably 1.0 N/25 mm or more, even more preferably 3.0 N/25 mm or more, and particularly preferably 5.0 N/25 mm or more, in terms of exhibiting better dust capture properties. Since household dust and other dust are relatively light, an adhesive layer 40 having an adhesive strength of 1.0 N/25 mm or more can capture dust sufficiently. In addition, in terms of exhibiting good slip properties on the object to be cleaned and suppressing the cleaning sheet 1 from sticking to the surface of the object to be cleaned, the 180-degree peel strength of the adhesive layer 40 is preferably 40 N/25 mm or less, more preferably 25 N/25 mm or less, even more preferably 20 N/25 mm or less, and particularly preferably 15 N/25 mm or less. The above 180-degree peel strength is a measured value based on a 180-degree peel test on a stainless steel (SUS304) plate specified in JIS Z 0237.
In addition, when the adhesive layer 40 does not extend in the surface direction of the cleaning surface 10, but is formed, for example, as a plurality of lines extending in one direction in the surface direction (in the case of a discontinuous coating), the 180-degree peel strength of the adhesive layer is obtained by converting the actually measured strength into the strength at a width of 25 mm as described above. In addition, when the adhesive layer 40 is a discontinuous coating as described above, it is difficult to obtain an average value, so the peak value (maximum value) observed in the measurement is used to obtain the 180-degree peel strength.

The above peel strength is measured in the following manner. A rectangular cut sheet-like test piece is taken out from the adhesive layer 40 supported on the support substrate 50. The length of the test piece is preferably about 100 to 200 mm, and the width is preferably about 15 to 25 mm. If the width of the test piece is less than 25 mm, the conversion value [N/25 mm] can be calculated (converted) from the ratio of the actual width of the test piece to the reference width of 25 mm. The thickness of the test piece is not particularly limited. One surface (the surface on the cleaning side) of the test piece is attached to a stainless steel (SUS304) plate, and a 2 kg roller is moved back and forth once to press the surface. If both sides of the test piece are adhesive, it is preferable to line the surface opposite to the surface to be measured with a polyethylene terephthalate (PET) film with a thickness of about 25 μm. The test sample prepared in this manner is kept in an environment of 23 ° C and 50% RH for 30 minutes. Then, using a tensile tester, the 180-degree peel strength (adhesive strength to SUS) [N/25 mm] is measured in accordance with JIS Z 0237 under conditions of 23°C, 50% RH, a peel angle of 180°, and a tensile speed of 300 mm/min. The tensile tester used is not particularly limited, and any conventionally known tensile tester can be used. For example, the "Tensilon" manufactured by Shimadzu Corporation can be used.

The average thickness of the adhesive layer 40 (if the adhesive layer has a multi-layer structure, the average total thickness of the multiple adhesive layers) can be set appropriately depending on the purpose, and is not particularly limited. The average thickness of the adhesive layer 40 is preferably 1 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, and particularly preferably 15 μm or more, in terms of exhibiting better dirt capture properties. The average thickness of the adhesive layer 40 is preferably 300 μm or less, more preferably 150 μm or less, even more preferably 60 μm or less, and particularly preferably 40 μm or less, in terms of exhibiting better slip properties and preventing glue residue on the object to be cleaned. The average thickness is the average of measurements at least at five randomly selected locations.

(Supporting Substrate)
The above-mentioned cleaning sheet 1 preferably includes a supporting substrate 50. By including the supporting substrate 50 in the above-mentioned cleaning sheet 1, the adhesive layer 40 is supported by the supporting substrate 50, so that deformation of the adhesive layer 40 during sliding contact can be suppressed. Therefore, the adhesive performance of the adhesive layer 40 is fully exhibited, and better dirt capture properties are exhibited.

The tensile strength of the support substrate 50 is preferably 5N/50mm or more. By having the tensile strength of the support substrate 50 be 5N/50mm or more, the adhesive layer 40 is more fully supported by the support substrate 50. As a result, as described above, the protrusions 12 can penetrate slightly into the adhesive layer 40 while being more fully supported by the adhesive layer 40 during sliding contact. This allows the adhesive recesses 14 to come slightly closer to the surface of the object to be cleaned. And, as the adhesive recesses 14 come closer to the surface of the object to be cleaned, the adhesive recesses 14 can capture dirt more reliably. The strength of the support substrate 50 may be 200N/50mm or less.

The tensile strength of the support substrate 50 is determined by measuring the tensile strength of the support substrate 50. Specifically, the strength (tensile strength) is measured by setting a test piece cut into a strip with a width of 50 mm in a tensile testing machine (distance between chucks: 100 mm) and measuring the tensile strength [N/50 mm] at a pulling speed of 200 mm/min.

The support substrate 50 may be various resin sheets, fiber sheets such as nonwoven fabric, woven fabric, and paper, metal foil, or a composite of these. The support substrate 50 preferably has at least one of a resin sheet and a fiber sheet. Resin sheets include synthetic resin films, rubber sheets, and foam sheets. Fiber sheets include nonwoven fabric, woven fabric, and paper.
The shape of the support substrate 50 is not particularly limited and may be flat, cylindrical, or the like, and may be a deformable material such as a cloth or sponge. The support substrate 50 may be made of polyolefin, polyester, other synthetic resins, paper, synthetic or natural fibers, or metals such as stainless steel.

Examples of materials for the resin sheet include polyolefin (PE, PP, ethylene-propylene copolymer, etc.), polyester (PET, etc.), vinyl chloride resin, vinyl acetate resin, polyimide resin, polyamide resin, fluororesin, etc. Examples of rubber sheets include natural rubber sheets and butyl rubber sheets. Examples of foam sheets include various foamed resin sheets such as polyethylene, polypropylene, polyurethane, ethylene-vinyl acetate copolymer (EVA), and polyethylene terephthalate (PET). Examples of paper include Japanese paper, craft paper, glassine paper, fine paper, synthetic paper, and topcoat paper. Examples of woven or nonwoven fabrics include those formed by a single type of fiber or a blend of multiple types of fibers. Examples of the above-mentioned fibers include cotton, staple fiber, Manila hemp fiber, pulp, rayon fiber, acetate fiber, polyester fiber, polyvinyl alcohol fiber, polyamide fiber, and polyolefin fiber. The manufacturing method of the nonwoven fabric may be spunlace, chemical bond, meltblown, steam jet, needle punch, etc. Examples of metal foils include aluminum foil and copper foil.

When a nonwoven fabric or foam with a large surface roughness (unevenness) is used as the support substrate 50, the convex portion component 30 and adhesive layer 40 may not adhere sufficiently to the support substrate 50 even if they are superimposed on the support substrate 50. In response to this, it is preferable to cover the nonwoven fabric or foam with a polyethylene film or polypropylene film and provide a smooth laminated layer on the surface of the support substrate 50. By smoothing the surface of the surface of the support substrate 50 with a laminated layer, it becomes possible to form the convex portion component 30 and adhesive layer 40 at high speed by coating, which will be described later. This allows the convex portion component 30 and adhesive layer 40 to be produced relatively quickly and easily.

The support substrate 50 may contain various additives such as fillers (inorganic fillers, organic fillers, etc.), anti-aging agents, antioxidants, UV absorbers, light stabilizers, antistatic agents, lubricants, plasticizers, colorants (pigments, dyes, etc.), etc., as necessary.

The thickness of the support substrate 50 is not particularly limited and can be appropriately selected depending on the purpose. The thickness of the support substrate 50 is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. The thickness of the support substrate 50 is preferably 5 mm or less, more preferably 3 mm or less, and particularly preferably 1 mm or less. The cleaning sheet 1 may be a rubber plate as the support substrate 50, and the adhesive layer 40 and the convex component 30 are provided on the support substrate 50. The above thickness is appropriately designed for the support substrate 50 made of, for example, a synthetic resin sheet, a nonwoven fabric, or paper.

The cleaning sheet 1 of this embodiment has an uneven cleaning surface, and is used by sliding the tips of the protrusions against the object to be cleaned. Therefore, even if the adhesive recesses, which have a relatively high adhesive force and are recessed further than the protrusions, do not come into contact with the object to be cleaned, the cleaning surface can move along the surface of the object to be cleaned. Therefore, the frictional force during sliding contact can be made relatively small. Therefore, the above-mentioned cleaning sheet has good sliding properties because it can slide against the surface of the object to be cleaned with a relatively small frictional force.
In addition, the ratio (H/L) of the average convex height (H: mm) from the tip of the convex to the adhesive concave to the average length (L: mm) of the shape of the adhesive concave in the first direction in which the average length of the gap in the surface direction of the cleaning surface is smallest is 15×10 ⁻³ or more, so that the tip of the convex can slide while preventing the adhesive concave from contacting the surface of the object to be cleaned. Therefore, while the convex is in sliding contact with the object to be cleaned, dirt can be collected in the gap in the member constituting the convex.
Furthermore, according to the cleaning sheet 1 of this embodiment, dirt can be effectively captured due to the adhesiveness of the adhesive recesses 14. For example, when a cleaning worker wipes, the cleaning sheet 1 slides against the object to be cleaned, and dirt on the object to be cleaned is captured in the adhesive recesses 14 of the cleaning surface 10. The captured dirt is collected in a depression near the adhesive recesses 14. Even if the captured dirt is relatively heavy, the adhesive force of the adhesive recesses 14 allows the dirt to continue to be captured.
In the cleaning sheet 1 of this embodiment, the ratio of the exposed area of the adhesive layer to the cleaning surface 10 is 30% or more, so that the cleaning sheet 1 can capture dust sufficiently.
On the other hand, when heavy dirt is captured by a conventional simple fiber aggregate, the weight of the captured dirt tends to separate from the fiber aggregate. Thus, with the cleaning sheet 1, even relatively heavy dirt such as sand grains, which are relatively difficult to capture, can be retained by the adhesive force of the adhesive recesses 14. Therefore, the cleaning sheet 1 has good dirt capture properties.
Thus, the cleaning sheet 1 having the above-mentioned structure has good slip properties and good dirt trapping properties.

(Optional other layers, components)
The cleaning sheet 1 of this embodiment may further include one or more layers, as necessary, in addition to the convex portion constituent members 30, the adhesive layer 40, and the supporting substrate 50 described above.
For example, in order to impart appropriate thickness, cushioning properties, strength, etc. to the cleaning sheet 1, an intermediate layer may be disposed between the convex component 30 and the adhesive layer 40. The intermediate layer may be a layer in which a gap similar to the gap A in the convex component 30 is formed. The configuration of the intermediate layer is not particularly limited, and may be a resin layer formed from various resin materials, a rubber layer (a natural rubber sheet, a butyl rubber sheet, etc.), a foam layer, a fibrous layer (paper, cloth, woven fabric or nonwoven fabric formed by spinning various fibrous materials alone or in a blend, etc.), a metal layer (typically a metal foil), or the like.
An anchor layer may be provided between the adhesive layer 40 and the support substrate 50 to improve anchoring properties.
On the back surface (non-adhesive layer surface) of the support substrate 50, various coating layers may be provided for imparting design properties or for improving handling properties.
In addition, in a cleaning sheet having a cleaning surface formed only on one side, an adhesive layer may be overlapped on the back side (opposite side of the cleaning surface) of the support substrate. The adhesive strength of the adhesive layer is higher than that of the component of the convex portion and lower than that of the adhesive layer. The adhesive layer may be formed of ethylene-vinyl acetate copolymer resin (EVA). When a plurality of cleaning sheets having such an adhesive layer are stacked in the same direction in the thickness direction, or when cleaning sheets having an adhesive layer are rolled and stacked, the stacked state is prevented from shifting, and the overlapping cleaning sheets can be prevented from strongly sticking to each other.
In addition, the convex portion may be formed of a self-adhesive material having self-adhesive properties, and the back surface of the support substrate may be formed of such a self-adhesive material. As the self-adhesive material, a low molecular weight tackifier or chloroprene rubber may be used. The convex portion formed of the self-adhesive material does not have much adhesion unless it comes into contact with other self-adhesive materials, and therefore exhibits slippage. On the other hand, when the self-adhesive material is also used for the back surface of the support substrate of the cleaning sheet, when the cleaning sheets are stacked as described above, the stacked state is prevented from shifting, and the overlapping cleaning sheets are prevented from strongly sticking to each other.

In addition, in a cleaning sheet in which a cleaning surface is formed only on one side, a rear side member 60 similar to the convex component may be provided on the rear side of the support substrate. For example, the rear side member 60 is composed of a plurality of linear members as shown in FIG. 8, and these linear members extend in the same direction as the extending direction of the convex component member 30 on the front side. When a plurality of cleaning sheets having such a configuration are stacked in the same direction in the thickness direction, or when cleaning sheets having such a configuration are rolled up and stacked, the convex portions of the convex component member and the convex portion of the rear side member 60 can be arranged alternately, so that the stacked state is prevented from shifting. In detail, the convex component member 30 of one cleaning sheet can be inserted between the rear side member 60 of the other cleaning sheet, and the cleaning sheet can be prevented from shifting in the width direction of the linear member.

The total thickness of the cleaning sheet 1 of this embodiment is not particularly limited. The total thickness of the cleaning sheet 1 having a sheet shape may be 1800 μm or less, 1000 μm or less, or 800 μm or less. The total thickness of the cleaning sheet 1 is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 250 μm or less, in terms of improving handling properties, etc. The total thickness may be 50 μm or more, or may be 120 μm or more. The total thickness is preferably 150 μm or more, more preferably 180 μm or more, and even more preferably 200 μm or more, in terms of exhibiting better slip properties and better dirt capture properties, etc. The total thickness is the average of thicknesses at least five randomly selected points.

(Manufacturing method of cleaning sheet)
The method for producing the cleaning sheet 1 of this embodiment is a method for forming the constituent members 30 of the protrusions by coating.

In the above manufacturing method, the constituent members 30 of the protrusions can be formed by coating on the supporting substrate 50 .
In addition, in the above manufacturing method, the convex portion constituent member 30 can be formed by being overlaid on the adhesive layer 40 by coating.
When the component 30 of the convex portion is overlaid on the supporting substrate 50 or the adhesive layer 40 by coating, the component 30 of the convex portion may be directly coated and overlaid on top of the supporting substrate 50 or the adhesive layer 40, or the component 30 of the convex portion may be first coated on another component to form the component 30, and then transferred to the supporting substrate 50 or the adhesive layer 40 (transfer method).

The manufacturing method of the cleaning sheet 1 of this embodiment includes, for example, an adhesive layer preparation step of preparing an adhesive layer 40 superimposed on the surface of the support substrate 50, and a convex portion preparation step of superimposing a convex portion component 30 on the surface of the support substrate 50 or the adhesive layer 40 to prepare the convex portion 12. The order of these steps is not particularly limited.

In the adhesive layer preparation step, the adhesive layer 40 can be prepared by a general method. This method is not particularly limited.
In the adhesive layer preparation step, the adhesive composition is directly applied to the support substrate 50 by a conventionally known coating means, and then cured or dried. Alternatively, the adhesive composition may be applied to a surface having releasability (e.g., the surface of a release liner, or the back surface of a support substrate that has been subjected to a release treatment, etc.), and the applied adhesive composition may be cured or dried to prepare the adhesive layer 40 on the surface. Alternatively, a method (transfer method) may be employed in which the adhesive layer 40 prepared on the surface having releasability is superimposed on the support substrate 50 or the component 30 of the convex portion.

In the adhesive layer preparation step, the adhesive layer 40 may be prepared over the entire range of one surface of the support substrate 50. On the other hand, for example, the adhesive composition may not be applied to both ends in the width direction of the belt-shaped support substrate 50, thereby providing the support substrate 50 with a non-adhesive portion (dry edge). Typically, a continuous layer-like adhesive layer 40 is prepared, but the adhesive composition may be applied to form a regular or random pattern such as a dotted, striped, or lattice pattern depending on the purpose and application. The adhesive layer may be prepared by applying the same adhesive composition or different adhesive compositions multiple times.
The coating method used in the adhesive layer forming step may be the same as the coating method used in the convex portion forming step described below.

In the adhesive layer preparation process, an adhesive composition containing an uncured resin that is cured by energy rays may be applied, and the adhesive layer 40 may be prepared by curing the composition by energy rays such as ultraviolet rays or electron beams. Specific examples of uncured resins include ultraviolet-curable (UV-curable) resins and electron-beam-curable (EB-curable) resins.

In the convex portion creation process, the convex portion 12 is formed, for example, by extrusion molding of a resin material melted by heating. Specifically, the resin material that is the raw material of the component 30 of the convex portion is extruded so as to draw multiple parallel lines, and a linear member is created on the support substrate 50 or the adhesive layer 40. Note that the linear member can also be created by extruding a resin composition containing a resin material, wax, and at least one of the uncured resins described above in the same manner as above, and irradiating it with energy rays as necessary.

In the convex portion creation process, various types of compositions are used as the resin composition for creating the convex portion component 30. For example, the above-mentioned hot melt type composition, curing type composition, water dispersion type (typically emulsion type) type composition, solvent type composition, etc. are used. These resin compositions may be applied directly onto the support substrate 50, or may be applied onto the adhesive layer 40 that is overlaid on the support substrate 50. Any coating method may be used, regardless of whether it is a direct printing method or a transfer method.

Examples of the coating method include roll coating, gravure coating, flexo coating, kiss coating (including microgravure coating), bar coating, comma coating, blade coating, die coating, slide coating, and curtain coating. As the coating method, die coating, gravure coating, and flexo coating, which are particularly excellent in coating fine patterns, are preferred. In the coating method, the resin composition may be coated so as to form a continuous layer, or the resin composition may be coated so as to form a regular or random non-continuous pattern such as a dot pattern, a stripe pattern, or a lattice pattern, depending on the purpose and application.
The adhesive layer 40 and the component 30 of the protrusions may each have a multi-layer structure of two or more layers. By foaming and coating the resin composition, the adhesive layer 40 or the component 30 of the protrusions can have cushioning properties.

In order to manufacture the cleaning sheet 1 at lower cost, it is also possible to simultaneously coat the adhesive layer 40 and the convex component 30 by employing die coating, slide coating, curtain coating, etc. The coating method for coating each composition for producing the adhesive layer 40 and the convex component 30 may be single-head coating in multi-layer simultaneous coating, or single-pass coating using multiple heads in tandem coating.
By preparing the adhesive layer 40 and the convex portion constituent members 30 by a coating method, the cleaning sheet 1 can be manufactured at low cost. Furthermore, when preparing the convex portion constituent members 30 by a coating method, the convex portion constituent members 30 may be a continuous layer that extends in the surface direction of the cleaning sheet 1, or may be a discontinuous layer with a dot pattern or the like.
For example, in conventional cleaning sheets that are manufactured by adhering a nonwoven fabric with openings to an adhesive layer, the nonwoven fabric cannot be made into a discontinuous layer. In contrast, in this embodiment, the coating pattern of the convex component 30 can be set so as to improve the slipperiness and dirt capture properties. Therefore, it is possible to arbitrarily set the exposure rate of the adhesive layer to 30% or more, which was not possible in conventional cleaning sheets.

(Use of cleaning sheets)
The cleaning sheet 1 can be used in various places, for example, in places where various kinds of garbage such as dust and debris are present. The cleaning sheet 1 captures garbage by the adhesive force of the adhesive recesses 14, and maintains the garbage capture, and is therefore better at capturing relatively heavy garbage such as sand grains, food scraps, and hair than conventional cleaning sheets made of simple fiber aggregates. The cleaning sheet 1 can be used with good durability not only on indoor flooring, but also on concrete surfaces such as entrance floors and dirt floors where sand grains are present, concrete surfaces installed on outdoor balconies, and rough factory floors with large unevenness that have been treated to prevent slipping.
The cleaning sheet 1 of this embodiment may be an embodiment that does not include a fiber aggregate, and therefore the cleaning sheet 1 of such an embodiment prevents the generation of fiber waste and paper dust, and is therefore suitable for use in clean rooms, food factories, hospitals, etc.

The cleaning sheet 1 may be used in a rolled state with the cleaning surface 10 facing outward, and can be used as a new type of adhesive roll cleaner.
Conventional adhesive roll cleaners rotate only in the winding direction, so they are used for cleaning by rolling (moving) only in this direction. Therefore, the operability is not particularly good when cleaning in narrow places. On the other hand, the above-mentioned new type of adhesive roll cleaner can capture dirt not only by rotating in the winding direction, but also by sliding (sliding) in a direction other than the rotation direction. Therefore, the operability is good when cleaning in narrow places. When the cleaning sheet 1 is wound into a roll as described above, unwinding and the like may occur. In response to this, an adhesive or adhesive may be provided on the whole or part of the back side (opposite the cleaning surface) of the cleaning sheet 1. This can suppress unwinding.

(Laminate)
The cleaning sheet 1 may be in a rolled state or a plurality of cleaning sheets 1 may be stacked in the thickness direction to form a laminate. An example of the laminate is shown in FIG.
By fixing the laminate to the sheet fixing part 120, after cleaning work is done with the cleaning surface 10 of the outermost cleaning sheet 1, the cleaning sheet 1 is removed and a new, unused cleaning sheet 1 is placed on the outermost side. Therefore, cleaning work can be continued with the new cleaning sheet 1 without replacing the cleaning sheet 1.

The matters disclosed in this specification include the following.
(1) A cleaning sheet having a cleaning surface that is brought into sliding contact with the surface of an object to be cleaned,
The cleaning surface has projections and recesses, and is used by bringing tips of the projections into sliding contact with the object to be cleaned;
the protrusions are formed of members spaced apart from one another in a surface direction of the cleaning surface,
the cleaning surface further has an adhesive recess having a higher adhesive strength than the member and exposed on the cleaning surface;
an adhesive layer extending in a surface direction of the cleaning surface and disposed in at least a part of the space between the members, at least a part of the adhesive layer constituting the adhesive recess, and a ratio of an exposed area of the adhesive layer to the cleaning surface being 30% or more;
the ratio (H/L) of an average convex height (H: mm) from the tip of the convex portion to the adhesive concave portion to an average length (L: mm) of the shape of the adhesive concave portion in a first direction in which the average length of the interval in the surface direction is smallest is 15× ^10-3 or more.
(2) The cleaning sheet according to (1) above, wherein the proportion of an exposed area of the adhesive layer on the cleaning surface is greater than 50%.
(3) The cleaning sheet according to (1) or (2) above, wherein the average convex height (H) from the tip of the convex portion to the adhesive concave portion is 1000×10 ⁻³ mm or less.
(4) The cleaning sheet according to the above (3), wherein the average convex portion height (H) is 500×10 ⁻³ mm or less.
(5) The cleaning sheet according to (4) above, wherein the average convex portion height (H) is 300×10 ⁻³ mm or less.
(6) The cleaning sheet according to any one of (1) to (5) above, wherein an average length (L) of the shape of the adhesive recesses in a first direction in which the average length of the intervals in the surface direction is smallest is 0.3 mm or more.
(7) The cleaning sheet according to (6) above, wherein the average length (L) is 0.5 mm or more.
(8) The cleaning sheet according to (7) above, wherein the average length (L) is 0.8 mm or more.
(9) The cleaning sheet according to (8) above, wherein the average length (L) is 1.0 mm or more.
(10) The cleaning sheet according to any one of (1) to (9) above, wherein a minimum load of a load curve when the member of the protrusions is measured by a nanoindentation method is −0.40 μN or more and 0 μN or less.
(11) The cleaning sheet according to (10) above, wherein a minimum load in a load curve when the member of the protrusions is measured by a nanoindentation method is −0.10 μN or more and 0 μN or less.
(12) The cleaning sheet according to any one of (1) to (11) above, wherein a minimum load in an unloading curve when the member of the protrusions is measured by a nanoindentation method is −1.50 μN or more and 0 μN or less.
(13) The cleaning sheet according to (12) above, wherein the minimum load of an unloading curve when the member of the protrusion is measured by a nanoindentation method is −0.10 μN or more and 0 μN or less.
(14) The cleaning sheet according to any one of (1) to (13) above, wherein the static friction coefficient of the cleaning surface is 1.00 or less. (15) The cleaning sheet further comprises an adhesive layer extending in a surface direction of the cleaning surface and disposed on the back surface side of the member, a part of the adhesive layer constituting the adhesive recessed portion,
The cleaning sheet according to any one of (1) to (14) above, wherein the hardness of the member measured by a nanoindentation method is 0.4 MPa or more, and the probe tack of the adhesive layer measured by a probe tack method is 1.0 kN/ ^m2 or more and 500.0 kN/m2 ^or less.
(16) The cleaning sheet according to any one of (1) to (15) above, wherein the member of the protrusions contains at least one of wax, hardened resin, and inorganic powder.
(17) The cleaning sheet according to any one of (1) to (16) above, wherein the member of the convex portion contains at least one of polyolefin resin, ethylene-vinyl acetate copolymer resin (EVA), styrene-based thermoplastic elastomer resin, acrylic resin, polyvinyl chloride resin, polyester resin, polyurethane resin, polyimide resin, polyamide resin, and polycarbonate resin.
(18) The cleaning sheet according to (16) above, wherein the members of the convex portions contain an extender pigment as the inorganic powder.
(19)
The cleaning sheet according to (16) above, wherein the wax contained in the member of the protrusions has a penetration hardness of 0.1 or more and 60 or less.
(20) The cleaning sheet according to any one of (1) to (19) above, wherein the cleaning surface is formed on both sides.
(21) A method for producing the cleaning sheet according to any one of (1) to (20) above, comprising the steps of:
The method for producing a cleaning sheet includes forming the members of the protrusions by coating.
(22) The cleaning sheet has a supporting substrate,
The method for producing a cleaning sheet according to (21) above, wherein the members of the convex portions are formed by coating on the supporting substrate.
(23) The cleaning sheet has a supporting substrate and an adhesive layer overlying the supporting substrate,
The method for producing a cleaning sheet according to (21) above, wherein the members of the convex portions are formed by coating on the adhesive layer.
(24) The cleaning sheet according to any one of (1) to (20) above in a rolled state, or
A laminate in which a plurality of cleaning sheets according to any one of (1) to (20) above are laminated in the thickness direction.
(25) A cleaning sheet according to any one of (1) to (20) above,
and a sheet fixing part to which the cleaning sheet is detachably attached.

The cleaning sheet 1, the laminate, and the cleaning tool 100 in the above embodiment are as exemplified above, but the present invention is not limited to the above exemplified cleaning sheet, laminate, and cleaning tool.
Furthermore, various aspects used in general cleaning sheets and cleaning tools can be adopted as long as they do not impair the effects of the present invention.

In the cleaning sheet 1 of the above embodiment, the adhesive layer 40 is supported by the support substrate 50, but the cleaning sheet of the present invention does not need to have a support substrate. For example, the cleaning sheet of the present invention may not have a support substrate, and the convex components 30 may be disposed on both sides of the adhesive layer.

In addition, in the cleaning sheet 1 of the above embodiment, the convex component 30 overlaps the adhesive layer 40, but the cleaning sheet of the present invention is not limited to such an embodiment. For example, as shown in FIG. 2B, the multiple line members of the convex component 30 may overlap in direct contact with the support substrate 50. In this case, the cleaning surface can also be formed by overlapping the line members of the convex component 30 on the surface of the support substrate 50 such as a resin film or nonwoven fabric with a gap therebetween, and then filling at least a part of the gap with an adhesive composition. In other words, an adhesive layer does not have to be disposed between the support substrate 50 and the convex component 30. For example, the cleaning surface can also be formed by forming the multiple line members of the convex component 30 on the support substrate 50 by coating, and coating an adhesive layer between the formed line members. Thus, in the cleaning sheet of the present invention, the configuration in which the convex component 30 overlaps the surface of the adhesive layer is not essential.

In addition, in the cleaning sheet 1 of the above embodiment, the exposed area of the adhesive recess 14 (the exposed area of the adhesive layer 40) was approximately the same as the total area of the interval A between the linear members of the component members 30 of the protrusions. However, in the cleaning sheet of the present invention, the exposed area of the adhesive layer 40 may be smaller than the total area of the above interval. For example, the recess formed by the above interval does not have to be entirely occupied by the adhesive composition. A part of the recess may be occupied by a linear (striped) adhesive composition or a dotted (dotted) adhesive composition. In this case, if the support substrate is a fiber aggregate, the surface of the fiber aggregate exposed to the cleaning surface can also capture dirt.

In addition, in the cleaning sheet 1 of the above embodiment, a non-cleaning surface 20 is formed on one side. However, in the cleaning sheet of the present invention, it is not necessarily necessary to form a non-cleaning surface 20. For example, a cleaning surface 10 may be formed on each side of the cleaning sheet.

Although the cleaning sheet 1 of the above embodiment has the convex component 30 in which a plurality of straight line members (linear members) are arranged in parallel, the cleaning sheet of the present invention is not limited to this. For example, as shown in Fig. 4, the convex component may be a member that is continuous in the planar direction of the cleaning surface 10, and holes (e.g. circular or elliptical holes) may be formed in such a member.
Further, for example, as shown in FIG. 5, the convex portion may be made of a mesh-like member that is continuous in the planar direction of the cleaning surface 10, and the adhesive layer 40 may be exposed in the mesh.
Also, for example, as shown in FIG. 6, a plurality of short line members may be arranged in the longitudinal direction, and the line members may be adjacent to each other in a direction perpendicular to the longitudinal direction, with gaps between them in both the longitudinal direction and the perpendicular direction.
Also, for example, as shown in FIG. 7, the constituent members of the convex portion may be formed so as to draw a plurality of letters or pictures.
The pattern drawn by the convex component 30 may be a regular pattern or an irregular pattern. For example, the pattern drawn by the convex component 30 may be any pattern, such as a dot pattern, a diamond pattern (rhombus shape), a star pattern (starfish shape), etc. As the pattern drawn by the convex component 30, a pattern that takes into consideration the dust capture efficiency may be selected, for example, as shown in JP 2011-183153 A.

In addition, the cleaning tool 100 in the above embodiment has a configuration in which the cleaning sheet 1 is attached to the sheet fixing part 120 at the lower end of the long-handled gripping member 110, but is not limited thereto. The cleaning tool of the present invention may have a short handle (also called a holder) as a gripping member. In addition, the cleaning tool of the present invention may have a configuration in which the cleaning sheet is attached to a member (sheet fixing part) having a shape such as a plate-like body, a spherical body, a cylindrical body, or the like without having such a gripping member. The cleaning tool of the present invention may be a cleaning tool having a soft sheet-like or sponge-like component member such as a cloth. Specifically, the cleaning tool of the present invention may have the above-mentioned cleaning sheet fixed to a part of a soft member, and the desired effect of the present invention can be achieved by such a configuration. Thus, in the cleaning tool of the present invention, there is no particular limitation on the shapes of the gripping member, the sheet fixing part, the cleaning sheet, etc., and there is no limitation on the materials of each of them. For example, various materials such as polyolefin, polyester, or other synthetic resins, synthetic or natural fibers, and metals such as stainless steel can be used as the component materials of the cleaning tool of the present invention.

Specifically, the cleaning tool 100 of the above embodiment may be a long and thin rod having the cleaning sheet 1 attached to the tip thereof. This cleaning tool 100 is used as a sliding adhesive type gap cleaning tool.
Furthermore, the cleaning tool 100 of the above embodiment may be, for example, a slipper with the cleaning sheet 1 attached to the bottom surface thereof. Since the cleaning tool 100 has a convex component, it is used as a product that allows cleaning while walking on the floor without sticking to the floor.
In these cleaning tools 100, the attached cleaning sheet 1 may be a single sheet, or may be in the form of a stack of a plurality of cleaning sheets.

Several examples of the present invention are described below, but it is not intended that the present invention be limited to these specific examples.

Example 1
[Preparation of Adhesive (Composition)]
The following raw materials were mixed to prepare a rubber-based adhesive (SIS-based adhesive composition).
Base polymer: styrene-isoprene-styrene block copolymer (SIS)
Zeon Corporation, product name "Quintac 3520" / 100 parts by mass Tackifier resin: Unhydrogenated hydrocarbon resin ENEOS Corporation, product name "T-REZ RC093" / 100 parts by mass Plasticizer: Naphthene-based process oil Idemitsu Kosan Co., Ltd., product name "Diana Process Oil NS90S" / 100 parts by mass [Preparation of convex component (convex composition)]
A composition for the convex portion, Sample 1, was prepared from the following raw materials.
・Resin material: High density polyethylene resin (HDPE)
Braskem product name "SHD7255LSL" / 100 parts by weight Resin material: ethylene-vinyl acetate copolymer resin (EVA)
Tosoh Corporation, product name "Ultrathene 684" / 200 parts by weight Wax: Hydrocarbon-based Sasol Corporation, product name "Sazol Wax C80" with a penetration of about 4 to 9 / 450 parts by weight A convex portion (streaky) having a plurality of linear members was formed as shown in Fig. 1. A cleaning sheet was also formed to have the schematic shape shown in Fig. 2A.

[Manufacturing of cleaning sheets]
A sheet was prepared as a support substrate by laminating one side of a paper sheet with a polyethylene film, and both the pressure-sensitive adhesive composition and the composition for protrusions obtained above were hot-melt coated (multi-layer simultaneous coating) using a die coater. The pressure-sensitive adhesive composition was directly coated on the non-laminated side that had not been laminated.
The cleaning sheets of the examples described below thus produced have a structure in which the components of the support substrate, adhesive layer, and protrusions are stacked in this order as shown in FIG. 2A , unless otherwise specified.
The components of the cleaning sheets in the examples described below are shown in Table 1.
Hardness of the component of the protrusion (nanoindentation method) [MPa]
Elastic modulus of the convex portion (nanoindentation method) [MPa]
- Slope of load curve in nanoindentation method [μN/nm]
・Minimum load on the load curve in the nanoindentation method [μN]
・Minimum load on unloading curve in nanoindentation method [μN]
Displacement of unloading curve in nanoindentation method [nm]
-Static friction coefficient of cleaning surface -Kinematic friction coefficient of cleaning surface -Thickness of adhesive layer [μm]
Probe tack of adhesive layer (kN/m ² )
・Adhesive layer exposure rate [%]
Average length L [mm] of the shape of the adhesive recess in the first direction
Distance A between adjacent wire members [mm]
Average convex height H [mm]
The ratio (H/L) of the average height of the convex portion (H: mm) to the average length (L: mm) of the shape of the adhesive concave portion
Average width of the convex part [mm]
・Constituents of the supporting substrate

Cleaning sheets with the configurations shown in Tables 1 to 5 were manufactured below. Unless otherwise specified, each cleaning sheet was basically manufactured in the same manner as in Example 1.

(Examples 2 to 8, 11)
The number of linear members and the average height of the protrusions were changed as shown in Tables 1 and 2, and various cleaning sheets were manufactured.

( Reference Example 9)
In Reference Example 9, a cleaning sheet was produced as follows.
[Preparation of Adhesive (Composition)]
Raw materials for acrylic adhesive (adhesive composition) Base polymer: Acrylic triblock copolymer/100 parts by mass Details of acrylic triblock copolymer * Acrylic block copolymer having a triblock structure of poly[methyl methacrylate (MMA)] block-poly[2-ethylhexyl acrylate (2EHA)/n-butyl acrylate (BA)] block-polyMMA block * The mass ratio of 2EHA to BA in the poly2EHA/BA block is 50/50, and the mass ratio of the poly2EHA/BA block to the polyMMA block (two polyMMA blocks) [(2EHA+BA)/MMA] is 82/18.
*Mw is 10 x 10 ⁴ , Mn is 8.4 x 10 ⁴ , and Mw/Mn is 1.21
・Plasticizer: Acrylic oligomer (liquid)
Toagosei Co., Ltd., product name "ARUFON UP1021" / 30 parts by mass Plasticizer: adipic acid ester type DIC Corporation, product name "Monocizer W-242" / 30 parts by mass [Preparation of convex portion constituent member (convex portion composition)]
A composition for the convex portion, Sample 2, was prepared using only the following raw materials.
Resin material: Polyolefin elastomer (glass transition temperature -48°C, melting peak top temperature 47°C)

( Reference Example 10)
In Reference Example 10, a cleaning sheet was produced as follows.
[Adhesive (composition)]
The same as in Reference Example 9 was used.
[Preparation of Constituent Member for Convex Portion (Composition for Convex Portion)]
A composition of Sample 3 for the convex portions was prepared using only the following raw materials.
Resin material: Polyurethane elastomer (glass transition temperature -50°C, melting peak top temperature 125°C, 166°C, aromatic polyether urethane)

(Examples 12 and 13)
A polypropylene (PP) spunbond nonwoven sheet (manufactured by Asahi Kasei Corporation, trade name "Eltas P03040", basis weight 40 g/ ^m2 ) was laminated on one side with a polyethylene film (20 g/ ^m2 ) to serve as a supporting substrate, and the adhesive composition was applied to the laminated surface. A cleaning sheet as shown in Fig. 1 and Fig. 2A was formed.

(Example 14)
Using the following composition as the adhesive composition, the following composition of Sample 4 as the composition for the protrusions, and the nonwoven fabric sheet described in Example 12 (but without lamination) as the supporting substrate, a cleaning sheet having the configuration shown in Table 3 was produced. Both the adhesive composition and the composition for the protrusions were directly applied to the supporting substrate, and the protrusions and adhesive layer were formed in streaks, as shown in Figures 1 and 2B.
[Preparation of Adhesive (Composition)]
The following raw materials were mixed to prepare a rubber-based adhesive (SIS-based adhesive composition).
Base polymer: styrene-isoprene-styrene block copolymer (SIS)
Zeon Corporation, product name "Quintac 3520" / 100 parts by mass Tackifier resin: Unhydrogenated hydrocarbon resin ENEOS Corporation, product name "T-REZ RC093" / 130 parts by mass Plasticizer: Naphthene-based process oil Idemitsu Kosan Co., Ltd., product name "Diana Process Oil NS90S" / 100 parts by mass [Preparation of convex component (convex composition)]
A composition of Sample 4 for the convex portion was prepared from the following raw materials.
-Resin material: Ethylene-vinyl acetate copolymer (EVA)
Tosoh Corporation, product name "Ultrasen 684" / 100 parts by weight Wax: Hydrocarbon-based Sasol Corporation, product name "Sasol Wax C80" needle penetration 4 to 9 / 225 parts by weight Mixed raw material: Polyolefin resin / calcium carbonate mixture (mass ratio 20/80)
Product name "Calpet A" manufactured by Nitto Funka Kogyo Co., Ltd. / 250 parts by weight (including 200 parts by weight of calcium carbonate)
Then, a protrusion (stripe-like) having a plurality of linear members was formed as shown in Fig. 1. Note that, as shown in Fig. 2B, the protrusion was formed so that the linear members were in direct contact with the supporting substrate.

(Example 15)
A cleaning sheet having the configuration shown in Table 3 was produced using the same adhesive composition as in Example 14, the composition for the convex portions of Sample 5 below as the composition for the convex portions of the cleaning sheet, and the nonwoven fabric sheet described in Example 12 (but not laminated) as the supporting substrate. As shown in Figures 1 and 2B, the convex portions and the adhesive layer were each formed in a streaky shape.
[Preparation of Constituent Member for Convex Portion (Composition for Convex Portion)]
A composition of Sample 5 for the convex portions was prepared from the following raw materials.
・Resin material: Linear low-density polyethylene resin (LLDPE)
Prime Polymer Co., Ltd. Product name "Evolue SP1071C" / 100 parts by mass Wax: Hydrocarbon-based Sasol Co., Ltd. Product name "Sasol Wax C80" needle penetration 4 to 9 / 143 parts by mass Mixed raw material: Polyolefin resin / calcium carbonate mixture (mass ratio 20 / 80)
Product name "Calpet A" manufactured by Nitto Funka Kogyo Co., Ltd. / 143 parts by weight (including 114 parts by weight of calcium carbonate)

(Examples 16 to 18)
The number of linear members, the average height of the protrusions, etc. were changed as shown in Table 3 to produce each cleaning sheet.

(Example 19)
A cleaning sheet having the configuration shown in Table 3 was manufactured using the same adhesive composition as in Example 14, a polyamide resin (manufactured by Daicel-Evonik, product name "Vestamelt 722GETR") as the material for Sample 6 for the convex portions, and the nonwoven fabric sheet described in Example 12 (but not laminated) as the supporting substrate. As shown in Figures 1 and 2B, the convex portions and the adhesive layer were each formed in a streaky shape.

( Reference Example 20)
A cleaning sheet having the configuration shown in Table 4 was manufactured using the same adhesive composition as in Example 14, ethylene-vinyl acetate copolymer resin (EVA) (manufactured by Tosoh Corporation, product name "Ultrathene 684") as the material for Sample 7 for the convex portions, and the nonwoven fabric sheet described in Example 12 (but not laminated) as the supporting substrate. Note that the convex portions and the adhesive layer were each formed in a streaky shape as shown in Figures 1 and 2B.

(Examples 21 and 22)
[Preparation of Adhesive (Composition)]
The following raw materials were mixed to prepare a rubber-based adhesive (SIS-based adhesive composition).
Base polymer: styrene-isoprene-styrene block copolymer (SIS)
Zeon Corporation, product name "Quintac 3421" / 100 parts by mass Tackifier resin: Unhydrogenated hydrocarbon resin ENEOS Corporation, product name "T-REZ RC093" / 130 parts by mass Plasticizer: Naphthenic process oil Idemitsu Kosan Co., Ltd., product name "Diana Process Oil NS90S" / 100 parts by mass The above composition was used as the adhesive composition, the composition of Sample 8 below was used as the convex composition, and the nonwoven fabric sheet described in Example 12 (but not laminated) was used as the supporting substrate to produce a cleaning sheet having the configuration shown in Table 4. Both the adhesive composition and the convex composition were directly applied to the supporting substrate, and the convex portions and adhesive layer were formed in stripes, respectively, as shown in Figures 1 and 2B.
[Preparation of Constituent Member for Convex Portion (Composition for Convex Portion)]
A composition of Sample 8 for the convex portion was prepared from the following raw materials.
・Resin material: Linear low-density polyethylene resin (LLDPE)
Prime Polymer Co., Ltd., product name "Evolue SP1071C" / 100 parts by mass Wax: Hydrocarbon-based Yasuhara Chemical Co., Ltd., product name "Neowax" needle penetration 5 / 143 parts by mass Mixed raw material: Polyolefin resin / calcium carbonate mixture (mass ratio 20 / 80)
Product name "Calpet A" manufactured by Nitto Funka Kogyo Co., Ltd. / 143 parts by weight (including 114 parts by weight of calcium carbonate)

(Examples 23 and 24)
[Preparation of Adhesive (Composition)]
The following raw materials were mixed to prepare a rubber-based adhesive (SIS-based adhesive composition).
Base polymer: styrene-isoprene-styrene block copolymer (SIS)
Zeon Corporation, product name "Quintac 3421" / 100 parts by mass Tackifier resin: Unhydrogenated hydrocarbon resin ENEOS Corporation, product name "T-REZ RC093" / 130 parts by mass Plasticizer: Naphthenic process oil Idemitsu Kosan Co., Ltd., product name "Diana Process Oil NS90S" / 80 parts by mass The above composition was used as the adhesive composition, the above Sample 8 composition was used as the convex composition, and the nonwoven fabric sheet described in Example 12 (but not laminated) was used as the supporting substrate to produce a cleaning sheet having the configuration shown in Table 4. Both the adhesive composition and the convex composition were directly applied to the supporting substrate, and the convex portions and adhesive layer were formed in stripes, as shown in Figures 1 and 2B.

(Comparative Examples 1 to 3)
A cleaning sheet having the configuration shown in Table 5 was produced in the same manner as in Example 1, except that only a polystyrene-based elastomer (styrene-hydrogenated butadiene copolymer SEBS, glass transition temperature -16°C, top melting peak temperature 102, 121°C) was used as the material for Sample 9 for the convex portions.

<Physical properties of convex portion constituent material>
As described below, the following physical properties were measured by nanoindentation.

(Nanoindentation method)
The hardness and elastic modulus of the convex portion were measured by nanoindentation in accordance with ISO 14577. Specifically, the measurements were performed under the following measurement conditions. The indentation depth of the indenter was 5 μm. The measurements were performed at 25° C. At least three measurements were performed to calculate the average value.
The details of the measurement method are as follows.
The cleaning sheet was cut in the thickness direction with a trimming knife to cut out the components of the protrusions. A sample consisting of only the components of the protrusions was used for measurement. A cross section was prepared with an ultramicrotome under freezing conditions (-30°C), and then fixed to a predetermined support (brass stand) to prepare the measurement sample.
Device: Nanoindenter "Triboindenter" manufactured by Hysitron
Indenter used: Berkovich type diamond indenter (triangular pyramid type indenter)
Measurement mode: Single push mode Measurement temperature: Room temperature (25°C)
Indentation depth: 5000 nm (5 μm)
Push-in speed: 500 nm/sec Pull-out speed: 500 nm/sec The following physical properties were calculated from the measurement results: The state during measurement is shown in Fig. 9A, and a schematic measurement chart is shown in Fig. 9B.
"Hardness"
It was calculated by dividing the "load when the indenter was pressed deepest (maximum load Pmax)" by the "area of contact between the indenter and the measurement sample (contact projected area B)".
"Elastic modulus"
The calculation was made using the above-mentioned formula (3) using the "slope of the tangent at the maximum load of the unloading curve (tangent stiffness S = dP/dh)" and the "area of contact between the indenter and the measurement sample (contact projected area B)".
"Load curve slope [μN/nm]"
This mainly corresponds to the compressive elastic modulus. The higher the value, the less likely the material is to be distorted by stress.
"Minimum load on load curve [μN]"
This is the minimum load value on the load curve. The more negative the value, the greater the wettability.
"Minimum load on unloading curve [μN]"
This is the minimum load value in the unloading curve. The larger the value in the negative direction, the greater the adhesive force (adhesive force).
"Displacement of unloading curve [nm]"
This is the amount of change in displacement in the unloading curve. The larger the value in the positive direction, the higher the stringiness, etc. (assuming the adhesiveness is the same).
For some of the cleaning sheets, the static and dynamic friction coefficients of the cleaning surface were measured by the method described above.

<Evaluation of Slipperiness>
The cleaning sheet produced by the above manufacturing method was attached to a commercially available wiper tool (Kao's Quickle Wiper main body), and wiped against a flooring surface (Daiken Corporation's Living Floor Art LVAT-MF) to evaluate slipperiness. The evaluation criteria were as follows:
◎: Very good slipperiness ○: Good slipperiness △: There is resistance to the floor when starting to slide, but it is good once it starts to slide ×: There is strong resistance to the floor and it does not slide at all, or there is strong resistance even after it starts to slide

<Evaluation of dust capture ability>
Within a flooring frame measuring 60 cm in length and 25 cm in width, 0.2 g of colored sand (CS-1004, 0.1-0.5 mm, available from Factory M Co., Ltd.) was spread as simulated garbage so as to be distributed almost uniformly.
One cleaning sheet manufactured as described above was attached to a commercially available wiper tool (Kao's Quickle Wiper main body), and a wiping operation was performed on a flooring (Daiken Corporation's Living Floor Art LVAT-MF) by moving the tool back and forth over a distance of 60 cm. Then, a wiping operation was performed again by moving the tool back and forth over a distance of 70 cm. The dust capture rate (dust capture rate [%], mass basis) was calculated as follows.
Dust capture rate [%] = (mass of sheet after wiping - mass of sheet before wiping)
÷ Amount of artificial garbage scattered (approximately 0.2 g) × 100%

As shown in Tables 1 to 4, the cleaning sheets of the Examples, in which the proportion of the exposed area of the adhesive layer on the cleaning surface was 30% or more and the ratio (H/L) of the average convex height (H: mm) from the tip of the convex portion to the adhesive concave portion to the average length (L: mm) of the shape of the adhesive concave portion in the first direction in which the average distance in the surface direction of the cleaning surface is the smallest, was 15×10 ⁻³ or more, exhibited good dirt capture properties. On the other hand, the cleaning sheets of the Comparative Examples were inferior in dirt capture properties to the Examples.

As can be seen from the above results, a cleaning sheet having an uneven cleaning surface, in which the adhesive recesses (adhesive layer) are exposed between adjacent protrusions, with an exposure rate of 30% or more, and in which the above-mentioned ratio (H/L) is 15× ^10-3 or more, has at least good dirt capture properties.

1: Cleaning sheet,
10: cleaning surface, 12: convex portion, 14: adhesive concave portion,
20: non-cleaning surface,
30: Constituent member of the protrusion,
40: adhesive layer,
50: supporting substrate,
A: Spacing,
100: cleaning tools,
110: gripping member,
120: sheet fixing part,
130: universal joint,
140: Radial slits.

Claims (24)

A cleaning sheet having a cleaning surface that is brought into sliding contact with the surface of an object to be cleaned,
The cleaning surface has projections and recesses, and is used by bringing tips of the projections into sliding contact with the object to be cleaned;
the convex portions are constituted by members formed at intervals in a surface direction of the cleaning surface, and the hardness of the members measured by a nanoindentation method is 10.0 MPa or more;
the cleaning surface further has an adhesive recess having a higher adhesive strength than the member and exposed on the cleaning surface;
an adhesive layer extending in a surface direction of the cleaning surface and disposed in at least a part of the space between the members, at least a part of the adhesive layer constituting the adhesive recess, and a ratio of an exposed area of the adhesive layer to the cleaning surface being 30% or more;
the ratio (H/L) of an average convex height (H: mm) from the tip of the convex portion to the adhesive concave portion to an average length (L: mm) of the shape of the adhesive concave portion in a first direction in which the average length of the interval in the surface direction is smallest is 15× ^10-3 or more. The cleaning sheet according to claim 1, wherein the proportion of the exposed area of the adhesive layer on the cleaning surface is greater than 50%. 3. The cleaning sheet according to claim 1, wherein an average convex height (H) from the tip of the convex portion to the adhesive concave portion is 1000×10 ⁻³ mm or less. The cleaning sheet according to claim 3, wherein the average convex portion height (H) is 500×10 ⁻³ mm or less. The cleaning sheet according to claim 4, wherein the average convex portion height (H) is 300×10 ⁻³ mm or less. The cleaning sheet according to any one of claims 1 to 5, wherein the average length (L) of the shape of the adhesive recess in the first direction in which the average length of the interval in the surface direction is the smallest is 0.3 mm or more. The cleaning sheet according to claim 6, wherein the average length (L) is 0.5 mm or more. The cleaning sheet according to claim 7, wherein the average length (L) is 0.8 mm or more. The cleaning sheet according to claim 8, wherein the average length (L) is 1.0 mm or more. The cleaning sheet according to any one of claims 1 to 9, wherein the minimum load of the load curve when the member of the convex portion is measured by the nanoindentation method is -0.40 μN or more and 0 μN or less. The cleaning sheet according to claim 10, wherein the minimum load of the load curve when the member of the convex portion is measured by the nanoindentation method is -0.10 μN or more and 0 μN or less. The cleaning sheet according to any one of claims 1 to 11, wherein the minimum load of the unloading curve when the member of the convex portion is measured by the nanoindentation method is -1.50 μN or more and 0 μN or less. The cleaning sheet according to claim 12, wherein the minimum load of the unloading curve when the member of the convex portion is measured by the nanoindentation method is -0.10 μN or more and 0 μN or less. The cleaning sheet according to any one of claims 1 to 13, wherein the static friction coefficient of the cleaning surface is 1.00 or less. The cleaning sheet according to any one of claims 1 to 14, wherein the probe tack of the adhesive layer measured by a probe tack method is 1.0 kN/m2 or ^more and 500.0 kN/ ^m2 or less. The cleaning sheet according to any one of claims 1 to 15, wherein the member of the protrusions contains at least one of wax, hardened resin, and inorganic powder. The cleaning sheet according to any one of claims 1 to 16, wherein the member of the protruding portion contains at least one of polyolefin resin, ethylene-vinyl acetate copolymer resin (EVA), styrene-based thermoplastic elastomer resin, acrylic resin, polyvinyl chloride resin, polyester resin, polyurethane resin, polyimide resin, polyamide resin, and polycarbonate resin. The cleaning sheet according to claim 16, wherein the member of the convex portion contains an extender pigment as the inorganic powder. The cleaning sheet according to any one of claims 1 to 18, wherein the cleaning surface is formed on both sides. A method for producing the cleaning sheet according to any one of claims 1 to 19, comprising the steps of:
The method for producing a cleaning sheet includes forming the members of the protrusions by coating. The cleaning sheet has a support substrate,
The method for producing a cleaning sheet according to claim 20, wherein the members of the protrusions are formed by overlaying them on the supporting substrate by coating. The cleaning sheet has a support substrate and an adhesive layer overlying the support substrate,
The method for producing a cleaning sheet according to claim 20, wherein the members of the convex portions are formed by coating on the adhesive layer. The cleaning sheet according to any one of claims 1 to 19 in a rolled state, or
A laminate in which a plurality of the cleaning sheets according to any one of claims 1 to 19 are laminated in the thickness direction. The cleaning sheet according to any one of claims 1 to 19,
and a sheet fixing part to which the cleaning sheet is detachably attached.