Pet sheet and package
The pet sheet design with a polyurethane adhesive layer addresses slipping and tearing issues by setting peel strength below tensile strength, providing effective slippage resistance and preventing unintended tearing.
Patent Information
- Application Number
- JP2024022019
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-02-16
- Publication Date
- 2025-08-28
AI Technical Summary
Existing pet sheets are prone to slipping and unexpected tearing due to adhesive layers adhering to each other, necessitating a solution that provides both slippage resistance and prevents unintended tearing.
A pet sheet design with an adhesive layer on the back surface of the back sheet, where the peel strength required to separate the adhesive layers is less than the tensile strength of the back sheet, and the adhesive layer is made from polyurethane resin to adjust peel strength effectively.
The pet sheet achieves both resistance to slippage and prevents unexpected tearing, ensuring stable adhesion to surfaces while maintaining usability and preventing sheet deformation.
Smart Images

Figure 2025125815000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a pet sheet and a packaging body. [Background technology]
[0002] A known pet excretion sheet (pet sheet) has a configuration that includes a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body interposed between the top sheet and the back sheet (see, for example, Patent Document 1). [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-332413 Summary of the Invention [Problem to be solved by the invention]
[0004] The above-mentioned pet sheets are usually placed on a floor or a tray (e.g., a pet toilet system) before use. Therefore, in order to use the pet sheet appropriately, it is necessary to make the pet sheet less likely to slip off the floor or other surface. One possible method for making the pet sheet less likely to slip off is to provide an adhesive layer (e.g., double-sided tape) on the back surface of the back sheet to adhere to the floor or other surface. However, when such an adhesive layer is provided, if the adhesive layers accidentally adhere to each other, there is a risk that the back sheet will unexpectedly tear when trying to peel them off. Therefore, for comfortable use of the pet sheet, it is necessary to achieve both resistance to slipping and prevention of unexpected sheet tearing.
[0005] Therefore, one aspect of the present disclosure aims to provide a pet sheet that is both resistant to slippage and prevents unexpected tearing of the sheet, and a packaging body that can suitably store the pet sheet. [Means for solving the problem]
[0006] A pet sheet according to one aspect of the present disclosure comprises a main body having a liquid-permeable top sheet, a back sheet, and an absorbent disposed between the top sheet and the back sheet, and an adhesive layer having adhesive properties is provided in at least a portion of the back surface of the back sheet opposite the top sheet side, and the peel strength required to separate the adhesive layers adhered to each other is less than the tensile strength of the back sheet.
[0007] Another aspect of the present disclosure is a packaging body that contains a plurality of pet sheets stacked on top of each other, each of the plurality of pet sheets having a main body portion having a liquid-permeable top sheet, a back sheet, and an absorbent body arranged between the top sheet and the back sheet, and an adhesive layer having adhesive properties is provided in at least a portion of the back surface of the back sheet opposite the top sheet side, and the peel strength required to separate the adhesive layers that are adhered to each other is smaller than the tensile strength of the back sheet, and a first pet sheet and a second pet sheet that are adjacent to each other within the packaging body are arranged so that a portion of the back surface of the first pet sheet and a portion of the back surface of the second pet sheet face each other and are in contact with each other, and an adhesive layer is provided on at least one of a portion of the back surface of the first pet sheet and a portion of the back surface of the second pet sheet. [Effects of the Invention]
[0008] According to the present disclosure, it is possible to provide a pet sheet that is both resistant to slippage and prevents unexpected tearing of the sheet, and a packaging body that can suitably store the pet sheet. [Brief explanation of the drawings]
[0009] [Figure 1] FIG. 1 is a plan view of a pet sheet according to an embodiment, viewed from the front side. [Figure 2] 2 is a plan view of the pet sheet of FIG. 1 as seen from the back side. FIG. [Figure 3] FIG. 3 is a cross-sectional view schematically showing the cross-sectional structure of the pet sheet taken along line III-III in FIG. [Figure 4] FIG. 4 is a cross-sectional view schematically showing the cross-sectional structure of the pet sheet taken along line IV-IV in FIG. [Figure 5] 5 is a cross-sectional view schematically showing the configuration of the topsheet in a range P in FIG. 4. FIG. [Figure 6] 6 is a cross-sectional view schematically showing the cross-sectional structure of the pet sheet taken along line VI-VI in FIG. 1. FIG. [Figure 7] 7 is a cross-sectional view schematically showing the cross-sectional structure of the pet sheet taken along line VII-VII in FIG. 1. FIG. [Figure 8] FIG. 1(A) is a diagram showing a schematic configuration of a back sheet and an adhesive layer according to a first example, and FIG. 1(B) is a diagram showing a schematic configuration of a back sheet and an adhesive layer according to a second example. [Figure 9] FIG. 10 is a diagram showing an example of a tray on which the pet sheet is placed. [Figure 10] FIG. 2 is a cross-sectional view schematically showing the arrangement of a tray and a pet sheet. [Figure 11] FIG. 2 is a diagram showing an example of a sample for measuring a first bending resistance and a second bending resistance. [Figure 12] FIG. 2 is a cross-sectional view schematically showing the internal structure of a package that contains a plurality of pet sheets. DETAILED DESCRIPTION OF THE INVENTION
[0010] At least the following aspects 1 to 27 become clear from the description of this specification and the accompanying drawings.
[0011] (Aspect 1) A main body portion includes a liquid-permeable top sheet, a back sheet, and an absorbent body disposed between the top sheet and the back sheet, an adhesive layer having adhesive properties is provided in at least a partial area of the back surface of the back sheet on the side opposite to the top sheet side; The pet sheet, wherein the peel strength required to separate the adhesive layers adhered to each other is smaller than the tensile strength of the back sheet.
[0012] In the pet sheet, an adhesive layer is provided on at least a portion of the back surface of the back sheet. This makes it difficult for the pet sheet to slip when placed on a floor or tray. Furthermore, the peel strength required to separate the adhesive layers that have been adhered to each other is smaller than the tensile strength of the back sheet. This makes it possible to separate the adhesive layers before the back sheet tears, even if the adhesive layers on the back surface are unintentionally stuck together. As a result, the pet sheet can achieve both slippage resistance and prevention of unexpected sheet tearing.
[0013] (Aspect 2) The pet sheet according to aspect 1, wherein the adhesive layer is formed from a polyurethane resin.
[0014] According to the second aspect, by using a polyurethane resin as the material of the adhesive layer, it is possible to easily adjust the peel strength so as to satisfy the above-mentioned conditions of the peel strength and the tensile strength of the backsheet.
[0015] (Aspect 3) The pet sheet of aspect 2, wherein the coefficient of static friction when the portions of the back surfaces on which the adhesive layers are provided are brought into surface contact with each other is 0.35 or more.
[0016] According to the third aspect, when the pet sheet is used by placing it on a tray, it is possible to achieve a preferable resistance to slippage.
[0017] (Aspect 4) The main body portion has a fold line for folding the main body portion, The pet sheet according to any one of Aspects 1 to 3, wherein the adhesive layer is disposed in a first region adjacent to the fold line on one side of the fold line.
[0018] When the pet sheet is placed on a floor, the portion along the fold line (the area near the fold line) tends to separate from the floor. According to the fourth aspect, by providing an adhesive layer in such a portion, the portion along the fold line can be made less likely to separate from the floor. As a result, the pet sheet can be effectively prevented from shifting.
[0019] (Aspect 5) The pet sheet according to aspect 4, wherein the adhesive layer is also disposed in a second region adjacent to the fold line on the opposite side of the fold line from the first region.
[0020] According to the fifth aspect, the effects described in the fourth aspect can be further enhanced.
[0021] (Aspect 6) The pet sheet according to any one of Aspects 1 to 5, wherein the adhesive layer is disposed in an area of the absorbent body that overlaps with the absorbent body.
[0022] If the absorber region is displaced, urine excreted by the pet may leak outside the absorber region. According to aspect 6, by arranging an adhesive layer in the absorber region, it is possible to prevent the absorber region from displacing from its original position and effectively prevent the occurrence of urine leakage.
[0023] (Aspect 7) The pet sheet according to any one of Aspects 1 to 6, wherein the adhesive layer is disposed in a flap region at the outer edge of the main body where the absorber is not disposed.
[0024] According to the seventh aspect, the flap region located on the outer edge of the main body can be made less likely to come off the floor surface, etc. As a result, when the pet sheet is placed on the floor and used, the flap region can be prevented from coming off the floor surface and getting caught on the pet's legs, etc. Furthermore, when the pet sheet is placed on a tray and used (i.e., when the flap region is placed along the side wall of the tray), the flap region can be prevented from moving inward from the side wall of the tray (i.e., the outermost part of the pet sheet moves inward), which can prevent the pet's urine from leaking outside the pet sheet.
[0025] (Aspect 8) the main body is formed in a shape having a plurality of sides when viewed in a thickness direction of the main body, The pet sheet according to any one of Aspects 1 to 7, wherein the adhesive layer is not disposed on an edge portion corresponding to at least one side of the main body portion.
[0026] According to the eighth aspect, when the pet sheet is to be disposed of (replaced), the pet sheet can be easily detached from the floor surface, etc., starting from the edge of the main body portion that does not have an adhesive layer and is not adhered to the floor surface, etc. This improves user convenience when disposing of the sheet.
[0027] (Aspect 9) the main body is formed in a shape having a plurality of sides when viewed in a thickness direction of the main body, the top sheet and the back sheet are joined to each other in a region surrounding the region where the absorbent body is disposed, The pet sheet of any one of aspects 1 to 8, wherein an edge portion corresponding to at least one side of the main body portion is provided with a non-bonded region where the top sheet and the back sheet are not bonded to each other.
[0028] According to aspect 9, even if an adhesive layer is placed on the back surface in the non-bonded area, the top sheet can be separated from the back sheet, so that the pet sheet can be easily pulled away from the floor surface, etc., by grasping the part of the top sheet that is separated from the back sheet in this manner.
[0029] (Aspect 10) The pet sheet according to any one of aspects 1 to 9, wherein the back sheet has a plurality of convex portions formed from the back surface side toward the opposite side of the back surface.
[0030] According to aspect 10, by providing an uneven structure on the back sheet, blocking and adhesion between the back sheet and the top sheet can be appropriately prevented, while the adhesive layer can be reliably provided on the smooth parts of the back surface excluding the convex parts (the parts that are recessed like a depression when viewed from the back surface), thereby improving the stability and effectiveness of the adhesive layer.
[0031] (Aspect 11) The pet sheet according to any one of aspects 1 to 9, wherein the back sheet has a plurality of convex portions formed from the opposite side of the back surface toward the back surface side.
[0032] According to aspect 11, similar to aspect 10, the provision of an uneven structure on the back sheet makes it possible to appropriately prevent blocking and adhesion between the back sheet and the top sheet. Furthermore, by providing the adhesive layer on the tip surface of the convex portion on the back surface, it is possible to prevent the adhesive strength of the back surface from becoming too strong and suppress tearing of the back sheet during use of the pet sheet.
[0033] (Aspect 12) 12. The pet sheet according to any one of aspects 1 to 11, wherein the peel strength is less than 10% of the tensile strength.
[0034] According to aspect 12, by setting the peel strength between the adhesive layers to be sufficiently small relative to the tensile strength of the back sheet, the risk of the back sheet tearing when the adhesive layers are separated can be more effectively reduced. Furthermore, when the adhesive layers are separated, deformation such as stretching of the back sheet is less likely to occur, which prevents the subsequent deterioration of the adhesion of the pet sheet to the floor surface, etc., and allows the pet sheet to properly maintain its slippage during use.
[0035] (Aspect 13) The main body portion is provided with a flap portion where the top sheet and the back sheet overlap and which extends outward beyond the outer edge of the absorbent body, A pet sheet according to any one of aspects 1 to 12, wherein a first flap portion of the flap portion arranged along at least one side of the main body portion has a first bending resistance when folded from the back sheet side to the top sheet side along the outer edge of the absorbent body, which is greater than a second bending resistance when the first flap portion is folded from the top sheet side to the back sheet side along the outer edge of the absorbent body.
[0036] In the pet sheet of aspect 13, the first flap portion corresponding to at least one side of the main body portion is configured such that the first bending resistance is greater than the second bending resistance. This allows the first flap portion to be pressed against the side wall of the tray when the first flap portion is folded from the backsheet side to the topsheet side along the outer edge of the absorbent core and placed along the side wall of the tray. This improves the adhesion between the first flap portion and the side wall of the tray, preventing gaps from forming between the first flap portion and the side wall of the tray. Therefore, when the pet sheet is placed on a tray, the pet sheet can prevent urine leakage between the pet sheet and the tray and improve the pet sheet's slippage resistance. Furthermore, when the pet sheet is placed on the floor, the first flap portion can be prevented from lifting off the floor (which would otherwise cause the pet sheet to slip off the floor).
[0037] (Aspect 14) The main body is formed in a rectangular shape when viewed in a thickness direction of the main body, 14. The pet sheet according to claim 13, wherein the first flap portions are provided at least along each of a pair of opposing sides sandwiching the absorber.
[0038] According to the fourteenth aspect, when the pet sheet is placed on a rectangular tray, each of the pair of first flaps of the pet sheet can be pressed against the pair of opposing side walls of the tray. This further improves the adhesion of the pet sheet to the tray and effectively prevents the pet sheet from shifting from the tray. As a result, urine leakage between the pet sheet and the tray can be more effectively prevented.
[0039] (Aspect 15) 15. The pet sheet of claim 13, wherein the thickness of the top sheet is 0.9 mm or more and less than 2 mm.
[0040] According to aspect 15, by ensuring a thickness of 0.9 mm or more for the top sheet, it is possible to prevent the first flap portion from bending from the back sheet side to the top sheet side along the outer edge of the absorbent body. Furthermore, by keeping the thickness of the top sheet to less than 2 mm, it is possible to prevent the pet sheet from becoming too heavy. Therefore, by setting the thickness of the top sheet within the above range, it is possible to achieve both improved adhesion of the first flap portion to the tray (side wall) and prevention of an increase in the weight of the pet sheet.
[0041] (Aspect 16) The pet sheet according to any one of Aspects 13 to 15, wherein a step portion that bends along the outer edge of the absorber is provided in the portion of the topsheet where the first flap portion is provided.
[0042] According to the sixteenth aspect, the first flap portion can be suitably prevented from bending from the backsheet side to the topsheet side along the outer edge of the absorbent body.
[0043] (Aspect 17) A pet sheet according to aspect 16, wherein the top sheet is formed of an air-through nonwoven fabric.
[0044] According to the seventeenth aspect, the structure (step portion) of the sixteenth aspect can be suitably formed.
[0045] (Aspect 18) 18. The pet sheet according to any one of Aspects 13 to 17, wherein the surface sheet has a basis weight greater than the basis weight of the back sheet.
[0046] According to the eighteenth aspect, the first flap portion can be suitably prevented from bending from the backsheet side to the topsheet side along the outer edge of the absorbent body.
[0047] (Aspect 19) The top sheet has a first surface opposite to the back sheet side and a second surface on the back sheet side, The pet sheet according to any one of aspects 13 to 18, wherein the fiber density of a first region on the first surface side of the topsheet is higher than the fiber density of a second region on the second surface side of the topsheet.
[0048] According to aspect 19, by making the first region of the top sheet (the region farther from the back sheet) a high-density region, the first flap portion can be suitably prevented from bending from the back sheet side to the top sheet side along the outer edge of the absorbent body.
[0049] (Aspect 20) A pet sheet according to any one of aspects 13 to 19, wherein the first flap portion has a fold line for folding the main body portion so that the back surface of the back sheet opposite the top sheet side faces outward along a first direction in which the first flap portion extends outward from the outer edge portion of the absorbent body.
[0050] According to Aspect 20, when the first flap portion is folded from the backsheet side to the topsheet side along the outer edge of the absorbent body and placed along the side wall of the tray, a convex portion that convexly projects toward the side wall of the tray is formed along the fold line of the first flap portion. The convex portion is pressed against the side wall of the tray, thereby further improving the adhesion of the pet sheet to the tray.
[0051] (Aspect 21) A pet sheet according to aspect 20, wherein the plurality of fold lines are spaced apart from one another in the thickness direction of the main body and in a second direction perpendicular to the first direction.
[0052] According to the twenty-first aspect, the effects described in the twenty-first aspect can be enhanced.
[0053] (Aspect 22) The folding line is provided over the entire area of the main body portion along the first direction, a first adhesive is disposed on the main body portion, the first adhesive extending linearly across the entire main body portion along the first direction; the first adhesive is disposed between the top sheet and the back sheet in the first flap portion, and is disposed between the absorbent body and the back sheet in the region overlapping with the absorbent body, 22. The pet sheet of aspect 20 or 21, wherein the first adhesive is arranged so as not to overlap the fold line.
[0054] According to aspect 22, by arranging the fold lines and the first adhesive so that they do not overlap each other, it is possible to avoid interference between the fold lines and the first adhesive, which makes it possible to prevent the main body from bending in an unintended direction due to the influence of the first adhesive when folding the main body along the fold lines.
[0055] (Aspect 23) The folding line is provided over the entire area of the main body portion along the first direction, a first adhesive is disposed on the main body portion, the first adhesive extending linearly across the entire main body portion along the first direction; the first adhesive is disposed between the top sheet and the back sheet in the first flap portion, and is disposed between the absorbent body and the back sheet in the region overlapping with the absorbent body, 22. The pet sheet of aspect 20 or 21, wherein the first adhesive is arranged so as to overlap the fold line.
[0056] According to the twenty-third aspect, by overlapping the first adhesive with the fold line, the shape of the first flap portion is easily maintained in the area overlapping with the fold line, thereby improving the adhesion of the first flap portion to the side wall of the tray.
[0057] (Aspect 24) The pet sheet according to any one of Aspects 13 to 23, wherein a second adhesive is disposed between the top sheet and the back sheet in the first flap portion.
[0058] According to the twenty-fourth aspect, the top sheet and the back sheet in the first flap portion are joined together by the second adhesive, which makes it easier to maintain the shape of the first flap portion, thereby improving the adhesion of the first flap portion to the side wall of the tray.
[0059] (Aspect 25) the second adhesive is disposed so as to straddle the outer edge portion of the absorbent body along the first flap portion, The pet sheet according to aspect 24, wherein the portion of the second adhesive that overlaps with the absorbent body is disposed between the top sheet and the absorbent body.
[0060] According to the twenty-fifth aspect, by fixing the portion of the topsheet that continues from the first flap portion to the absorbent body, the shape stability of the first flap portion can be further improved.
[0061] (Aspect 26) the adhesive layer has a first adhesive region having a first adhesive strength and a second adhesive region having a second adhesive strength smaller than the first adhesive strength; The pet sheet according to any one of aspects 1 to 25, wherein a boundary is formed between the first adhesive region and the second adhesive region.
[0062] According to the twenty-sixth aspect, the effects described in the first aspect can be further improved.
[0063] (Aspect 27) A packaging body containing a plurality of pet sheets stacked on top of each other, Each of the plurality of pet sheets includes a main body portion having a liquid-permeable top sheet, a back sheet, and an absorbent body disposed between the top sheet and the back sheet, an adhesive layer having adhesive properties is provided in at least a partial area of the back surface of the back sheet on the side opposite to the top sheet side; The peel strength required to separate the adhesive layers adhered to each other is smaller than the tensile strength of the back sheet, The first pet sheet and the second pet sheet adjacent to each other in the packaging body are arranged so that a part of the back surface of the first pet sheet and a part of the back surface of the second pet sheet face each other and come into contact with each other, The packaging body, wherein the adhesive layer is provided on at least one of a portion of the back surface of the first pet sheet and a portion of the back surface of the second pet sheet.
[0064] If the package is subjected to vibrations or impacts during transport, etc., some of the pet sheets contained within the package may shift position, potentially deforming the main body of the pet sheet. This deformation of the main body may cause the back surface of the pet sheet to not properly contact the floor or other surface when in use, making the pet sheet more likely to shift. In contrast, in the above-mentioned package, adjacent first and second pet sheets are housed so that their back surfaces face and contact each other via an adhesive layer. This prevents adjacent pet sheets from shifting position within the package even when vibrations or impacts are applied to the package, making each pet sheet less likely to deform within the package. As a result, the pet sheets are less likely to shift position relative to the floor or other surface when in use.
[0065] [Embodiment] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following description, the same or equivalent elements will be designated by the same reference numerals, and redundant description will be omitted.
[0066] (Pet Sheet) A pet sheet 1 according to one embodiment will be described with reference to Figs. 1 to 10. The pet sheet 1 is a sheet that has the function of absorbing animal excrement (mainly urine). The animal to which the pet sheet 1 is applied is, for example, an animal kept as a pet, and may be, for example, a mammal such as a dog, cat, or hamster, or may be a non-mammalian creature such as a bird, reptile, or amphibian. The pet sheet 1 is used by being placed, for example, on the floor or on a tray (for example, tray 60 shown in Fig. 10) that constitutes a toilet dedicated to pets (system toilet).
[0067] For convenience, in this specification, the thickness direction of the pet sheet 1 is referred to as the Z-axis direction, the longitudinal direction of the pet sheet 1 is referred to as the X-axis direction, and the short-side direction of the pet sheet 1 (the direction parallel to the folding line L1 of the pet sheet 1 described later) perpendicular to the Z-axis direction and the X-axis direction is referred to as the Y-axis direction. Hereinafter, the above directions will be referred to as the XYZ Cartesian coordinate system shown in the drawings, and the thickness direction (Z-axis direction) will be referred to as the "thickness direction Z," the long-side direction (X-axis direction) as the "long-side direction X," and the short-side direction (Y-axis direction) as the "short-side direction Y."
[0068] As shown in Figures 1 and 2, the pet sheet 1 has, as an example, a main body 10 formed in a substantially rectangular shape in a plan view. However, the shape of the main body 10 in a plan view is not limited to a rectangular shape, and any shape such as a polygon, circle, or ellipse can be adopted. The size of the main body 10 can be set appropriately depending on the size, type, etc. of the pet to which the pet sheet 1 is applied. The main body 10 has a top sheet 2, a back sheet 3, an absorbent body 4, and an adhesive layer 5.
[0069] The top sheet 2 is made of a liquid-permeable sheet material. When the pet mat 1 is in use, the top sheet 2 is placed on the side where pet excrement is supplied. The top sheet 2 has a surface 2a (first surface) that is exposed to the outside (upward) when placed on the floor or the tray of a system toilet, and an inner surface 2b (second surface) opposite the surface 2a. The top sheet 2 is made of a liquid-permeable sheet material so that excrement supplied to the surface 2a can be moved to the back sheet 3 side (inner surface 2b side). As an example, the sheet material constituting the top sheet 2 is made of white fibers. Examples of such sheet materials include nonwoven fabrics such as air-through nonwoven fabrics, spunbond nonwoven fabrics, and point-bond nonwoven fabrics. In this embodiment, the top sheet 2 is made of air-through nonwoven fabric.
[0070] The back sheet 3 is a sheet located on the opposite side of the top sheet 2 in the thickness direction Z. As an example, the back sheet 3 is formed in a rectangular shape similar to the top sheet 2 so as to overlap the top sheet 2 when viewed in the thickness direction Z. The back sheet 3 has a back surface 3a that faces the floor or the support surface of a toilet tray when the pet sheet 1 is in use, and an inner surface 3b opposite the back surface 3a. As an example, the back sheet 3 can be made of a liquid-impermeable sheet material. Examples of sheet materials that make up the back sheet 3 include non-breathable resin films such as polyethylene and polypropylene, laminates in which nonwoven fabrics are bonded to such resin films, and water-repellent or hydrophobic nonwoven fabrics. When the back sheet 3 is made of a liquid-impermeable sheet material, it is possible to prevent excrement excreted on the pet sheet 1 from leaking onto the floor or the support surface of a toilet tray. However, the back sheet 3 may also be made of a liquid-permeable material. For example, when pet sheet 1 is placed on top of another pet sheet (e.g., an absorbent sheet that is larger in size in a plan view than pet sheet 1), by deliberately making the back sheet 3 liquid-permeable, urine that cannot be absorbed by pet sheet 1 can be absorbed by the other pet sheet.
[0071] The absorbent body 4 is disposed between the topsheet 2 and the backsheet 3. As shown in FIGS. 1 and 2, the absorbent body 4 is formed in a rectangular shape slightly smaller than the main body portion 10 (the topsheet 2 and the backsheet 3) when viewed in the thickness direction Z, and is disposed in the center of the main body portion 10, excluding the peripheral edge portion. As shown in FIGS. 3 and 4, for example, the absorbent body 4 is composed of an absorbent core 41 formed of an absorbent material for absorbing and retaining bodily waste, and a core wrap 42 covering the absorbent core 41. The absorbent core 41 may be composed of a granular absorbent polymer. The absorbent polymer constituting the absorbent core 41 may be any polymer capable of absorbing and retaining liquid, and may be any highly absorbent polymer, such as a polyacrylic acid-based, starch-based, or cellulose-based polymer. The core wrap 42 may be composed of, for example, a plain white tissue. For example, the absorbent body 4 is white before use (i.e., when not absorbing or retaining bodily waste).
[0072] As shown in FIGS. 2 to 4, an adhesive layer 5 having adhesiveness is provided in at least a portion of the back surface 3a of the backsheet 3. As shown in FIG. 2, in this embodiment, the adhesive layer 5 is provided over the entire area AD excluding areas E on both edges of the main body 10 in the longitudinal direction X. However, the arrangement of the adhesive layer 5 is not limited to this embodiment, and the adhesive layer 5 may be partially disposed on the back surface 3a. As an example, the area AD is provided with an adhesive region 51 (first adhesive region) having a first adhesive strength and an adhesive region 52 (second adhesive region) having a second adhesive strength smaller than the first adhesive strength, by varying the amount (thickness, etc.) or type of material constituting the adhesive layer 5. For example, the thickness of the adhesive layer 5 in each of the adhesive regions 51 and 52 is approximately several μm. As an example, a plurality of independent elliptical adhesive regions 52 are arranged in a predetermined repeating pattern. As a result, the boundary B (in this embodiment, the outline of each adhesive region 52) between the adhesive regions 51 and 52, which have different adhesive strengths, is distributed throughout the entire area AD. By providing such boundary B, the effect of the adhesive layer 5 (i.e., the effect of preventing the pet sheet 1 from slipping off the floor or the tray surface) can be improved. More specifically, because the boundary B easily catches on the floor or the tray surface, even if the adhesive strength of the adhesive layer 5 as a whole is relatively weak to satisfy the condition of "peel strength < tensile strength" described below, the pet sheet 1 can be prevented from slipping off the floor or the tray surface. Furthermore, if the adhesive layer 5 has a color other than white (e.g., green), the adhesive region 51 and the adhesive region 52 can have different colors. This can also improve the appearance (design) of the back sheet 3 side of the pet sheet 1.
[0073] Because the adhesive layer 5 is provided on the back surface 3a as described above, there is a risk that the adhesive layers 5 may adhere to each other when the pet sheet 1 is folded so that the back surface 3a faces inward. In this case, if the adhesive strength of the adhesive layer 5 is too strong, when the adhesive layers 5 are peeled away from each other, the back sheet 3 may tear before the adhesive layers 5 are separated. Therefore, the pet sheet 1 is configured so that the peel strength required to separate the adhesive layers 5 is smaller than the tensile strength of the back sheet 3. In other words, the pet sheet 1 is configured so that when an attempt is made to separate the adhesive layers 5, the adhesive layers 5 are separated from each other before the back sheet 3 tears. The peel strength is, for example, the measurement result (N / 100 mm) obtained in "7." of the <Peel Strength Test> below. The tensile strength of the back sheet 3 is, for example, the measurement result (N / 100 mm) obtained in "4." of the <Tensile Strength Test> below in accordance with "JIS P 8113."
[0074] <Peel strength test> 1. Two test pieces (100 mm x 100 mm test pieces consisting of the back sheet 3 and the adhesive layer 5) included in the area AD are cut out. 2. The two test pieces are stacked with the adhesive layers 5 facing each other, and a pressure of 300 mmHg is applied to these two test pieces for one minute so that the two test pieces are pressed against each other in the opposing direction in which the adhesive layers 5 face each other. 3. By attaching cloth tape to the edge (the outer surface of each test piece (the surface opposite the back surface 3a of the back sheet 3)) corresponding to one common side of each of the two test pieces stacked on top of each other, gripping portions (cloth tape attached to one test piece and cloth tape attached to the other test piece) are created. 4. The measurement atmosphere is kept at constant temperature and humidity (20±2°C, 60±5%RH), and the gripped portion of each test piece is fixed by clamping it between each of the two chucks of a tensile testing machine (e.g., Shimadzu Autograph AG-50-NXplus HS, etc.). 5. Set the load of the tensile tester to 0 and start the measurement. Specifically, pull the gripped portions of each test piece in opposite directions parallel to the above-mentioned opposing directions at a speed of 100 mm / min. 6. After the measurement is completed (after the two test pieces are peeled off), read the maximum load (N / 100mm) measured during the measurement. 7. Perform the measurements 1 to 6 above on multiple (e.g., three) test pieces, and obtain the average value of the measurement results of the multiple test pieces (the maximum load obtained in "6.") as the final measurement result.
[0075] <Tensile strength test> 1. From the back sheet 3 and adhesive layer 5 included in the area AD, a plurality of (e.g., three) test pieces Sa1 to Sa3 are cut out to a width of 100 mm and a length of 80 mm so that the width direction coincides with the longitudinal direction X, and a plurality of (e.g., three) test pieces Sb1 to Sb3 are punched out to a width of 100 mm and a length of 80 mm so that the width direction coincides with the short direction Y. 2. To leave a central length of 50 mm for each of the test pieces Sa1 to Sa3 and Sb1 to Sb3, clamp both ends of each test piece Sa1 to Sa3 and Sb1 to Sb3 in the longitudinal direction with aluminum tape and paper to create a gripping portion. 3. For each test piece, carry out the following steps "3-1" to "3-3". 3-1. Fix the test piece by clamping the gripping parts (aluminum tape parts) at both ends of the length of the test piece between each of the two chucks of a tensile testing machine (e.g., Shimadzu Autograph AG-50-NXplus HS, etc.). 3-2. Set the load of the tensile tester to 0 and start the measurement. Specifically, the gripped portions at both ends of the test piece in the longitudinal direction are pulled in opposite directions along the length of the test piece at a speed of 200 mm / min. 3-3. After the measurement is completed (after the sample breaks), read the maximum load (N / 100mm) measured during the measurement. 4. The average value of the maximum loads (maximum loads obtained in "3-3") of the test pieces Sa1 to Sa3 and Sb1 to Sb3 is obtained as the final measurement result.
[0076] Here, "the adhesive layer 5 has adhesiveness" means that a measurement result greater than "0 (N / 100 mm)" is obtained in the peel strength test. In other words, if the two test pieces do not stick together even after performing "2." in the peel strength test, the two test pieces will naturally separate after performing "4." in the peel strength test (before the measurement begins), and measurements from "5." onward cannot be performed. Such a layer does not qualify as an adhesive layer. Furthermore, if the back sheet 3 of at least one of the test pieces tears before the adhesive layers 5 of the two test pieces separate in "5." in the peel strength test, a measurement result for the peel strength between the adhesive layers 5 cannot be obtained in the peel strength test. In this case, since the back sheet 3 tears before the adhesive layers 5 separate, this corresponds to the case where "the peel strength required to separate the adhesive layers 5 is greater than the tensile strength of the back sheet 3."
[0077] Below, we will explain some of the effects of the pet sheet 1 described above. In the pet sheet 1, the adhesive layer 5 is provided in at least a partial region of the back surface 3a of the back sheet 3 (in this embodiment, the region excluding region E on both edges in the longitudinal direction X of the main body 10). This makes it possible to prevent the pet sheet 1 from slipping when placed on a floor or a tray. Furthermore, the peel strength required to separate the adhesive layers 5 that have been bonded to each other is smaller than the tensile strength of the back sheet 3. This makes it possible to separate the adhesive layers 5 from each other before the back sheet 3 tears, even if the adhesive layers 5 on the back surface 3a (the adhesive layers 5 at two different locations on the back surface 3a) accidentally stick together. As described above, the pet sheet 1 can achieve both slippage resistance and prevention of unexpected sheet tearing.
[0078] Table 1 below shows the measurement results of the peel strength test and the tensile strength test for two Examples 1 and 2 that satisfy the above-mentioned condition of "peel strength < tensile strength" for the peel strength and the tensile strength of the backsheet 3, and three Comparative Examples 1 to 3 that do not satisfy the above condition. Both Examples 1 and 2 have an adhesive layer 5 formed from a polyurethane resin, and Example 1 has a higher adhesive strength (a larger amount of adhesive layer 5) than Example 2.
[0079] [Table 1]
[0080] The peel strength measurement results (impossible to measure) for Comparative Examples 1 to 3 in Table 1 above indicate that in the above-mentioned peel strength test, the back sheet broke before the adhesive layers on the back surface of the back sheet peeled off, making it impossible to measure the peel strength. That is, in Comparative Examples 1 to 3, although the material strength (tensile strength) of the back sheet was made higher than the tensile strength of the back sheets of Examples 1 and 2, the adhesive strength of the adhesive layer was even stronger than that, and as a result, the back sheet broke first in the peel strength test.
[0081] As in Examples 1 and 2 above, the peel strength may be set to be less than 10% of the tensile strength. Note that in Examples 1 and 2 above, the peel strength is set to be less than 2% of the tensile strength. As described above, by setting the peel strength between the adhesive layers 5 to be sufficiently smaller than the tensile strength of the back sheet 3, the risk of the back sheet 3 tearing when the adhesive layers 5 are pulled apart can be more effectively reduced. Furthermore, when the adhesive layers 5 are peeled apart, deformation such as stretching of the back sheet 3 is less likely to occur, which prevents the subsequent adhesion of the pet sheet 1 to the floor surface, etc. from deteriorating, and allows the pet sheet 1 to maintain proper slippage resistance during use.
[0082] The adhesive layer 5 may be formed of polyurethane resin as in the above Examples 1 and 2. By using polyurethane resin as the material for the adhesive layer 5, it is possible to easily adjust the peel strength of the adhesive layer 5 to satisfy the above-mentioned condition of the peel strength and the tensile strength of the backsheet 3 (i.e., the condition of "peel strength<tensile strength").
[0083] The static friction coefficient when the portions of the back surface 3a of the backsheet 3 on which the adhesive layer 5 is provided are brought into surface contact is preferably 0.35 or more. The static friction coefficient is, for example, the average friction coefficient (MIU) (unitless) obtained in "3." of the <Friction Test> below. If there is variation in the measurement results between when the adhesive layers 5 are shifted in the longitudinal direction X and when the adhesive layers 5 are slid in the lateral direction Y, the average friction coefficients may be obtained for each of the cases where the adhesive layers 5 are shifted in the longitudinal direction X and the lateral direction Y, and the average value of the respective average friction coefficients (added and divided by 2) may be calculated as the static friction coefficient.
[0084] <Friction test> 1. The back sheet 3 is attached to the surface of the friction element of a surface tester (for example, KES FB-4 manufactured by Kato Tech Co., Ltd.) so that the back surface 3a on which the adhesive layer 5 is provided faces outward. 2. Another back sheet 3 (100 mm x 100 mm) is placed in a position facing the friction element prepared in "1." The other back sheet 3 is placed so that the back surface 3a on which the adhesive layer 5 is provided faces the friction element. 3. The friction element is brought into contact with another back sheet 3 and slid to obtain the average coefficient of friction (MIU).
[0085] By setting the static friction coefficient to 0.35 or higher, the pet sheet 1 can exhibit favorable slippage resistance when placed on a tray for use. More specifically, the inventors prepared multiple pet sheets 1 (samples A to D) with different static friction coefficients. For each sample A to D, 40 cc of liquid (tap water) was poured from the surface 2a of the topsheet 2 to the area where the absorbent 4 was located. After the liquid was absorbed by the absorbent 4, the pet sheet 1 was placed on a flat test table with a larger area than the pet sheet 1, and a tilt test was conducted to check whether the pet sheet 1 would slip when the test table was tilted 70° relative to the horizontal (the evaluation result was "OK" if the pet sheet 1 did not slip, and "NG" if the pet sheet 1 did slip). The test results shown in Table 2 below were obtained. A smooth plastic plate made of polypropylene was used as the test table.
[0086] [Table 2]
[0087] The results of the tilt test above show that even if the tray is unintentionally tilted (tilted 70° from the horizontal) when carrying the pet sheet 1 that has absorbed 40cc of liquid, which is the average amount of urine a cat produces in half a day, to replace it from the tray, the pet sheet 1 will not easily slide off the tray (will not slip off) if the static friction coefficient is 0.35 or higher. Furthermore, by forming the adhesive layer 5 from a polyurethane resin, a static friction coefficient of 0.35 or higher can be easily achieved.
[0088] As shown in FIG. 1 , the main body 10 has a fold line L for folding the main body 10. In this embodiment, two fold lines L1 and L2 are provided at positions that divide the main body 10 into approximately three equal parts in the longitudinal direction X. The fold lines L1 and L2 may be formed, for example, by creases previously formed in the main body 10. In this embodiment, valley folds are provided on the fold lines L1 and L2 when viewed from the front surface 2a of the topsheet 2. In this embodiment, the adhesive layer 5 is disposed in a first region A1 adjacent to the fold line L1 on one side (in this embodiment, outside the longitudinal direction X) of the fold line L1. The first region A1 may be defined as a region having a predetermined width (e.g., a width of 1 cm or more) in a direction perpendicular to the fold line L1 (in this embodiment, the longitudinal direction X).
[0089] The portion along the fold line L1 (the region near the fold line L1) is likely to separate from the floor when the pet sheet 1 is placed on a floor or the like. As described above, by arranging the adhesive layer 5 in at least the first region A1, the portion along the fold line L1 (the first region A1) can be made less likely to separate from the floor or the like. As a result, slippage of the pet sheet 1 can be effectively suppressed. Furthermore, in this embodiment, the adhesive layer 5 is also arranged in the second region A2 adjacent to the fold line L1 on the opposite side of the fold line L1 from the first region A1. This further enhances the above-mentioned effect. Note that in this embodiment, the region AD where the adhesive layer 5 is arranged also covers the region near the fold line L2, so the same can be said about the fold line L2 as about the fold line L1.
[0090] As shown in FIG. 2, the adhesive layer 5 is disposed in the absorber region A that overlaps with the absorber 4. If the absorber region A becomes misaligned, urine excreted by the pet may leak outside the absorber region A. By disposing the adhesive layer 5 in the absorber region A, it is possible to prevent the absorber region A from becoming misaligned and effectively prevent the occurrence of the above-mentioned urine leakage. In this embodiment, the region AD where the adhesive layer 5 is disposed completely covers the absorber region A, but to achieve the above-mentioned effect, it is sufficient that the adhesive layer 5 is disposed in at least a portion of the absorber region A.
[0091] As shown in FIG. 2, the adhesive layer 5 is disposed in flap regions (flap portions F) at the outer edge of the main body portion 10 where the absorbent body 4 is not disposed. In this embodiment, the flap portion F has a pair of flap portions F1 extending in the longitudinal direction X at both edges in the lateral direction Y, and a pair of flap portions F2 extending in the lateral direction Y at both edges in the longitudinal direction X. Adjacent flap portions F1, F2 overlap each other at the four corners of the main body portion 10. The adhesive layer 5 is disposed on both flap portions F1, F2. More specifically, the adhesive layer 5 is disposed on a portion of each flap portion F1 other than both edge portions in the longitudinal direction X (regions included in region E). The adhesive layer 5 is also disposed on a portion of each flap portion F2 other than both edge portions in the longitudinal direction X (regions included in region E).
[0092] By providing the adhesive layer 5 on at least a portion of the flap portions F1, F2 as described above, the flap portions F1, F2 located on the outer edge of the main body 10 are less likely to come off the floor surface, etc. This prevents the flap portions F1, F2 from coming off the floor and getting caught on the pet's legs, etc., when the pet sheet 1 is placed on a floor and used. Furthermore, when the pet sheet 1 is placed on a tray (i.e., when the flap portions F1, F2 are placed along the side walls 62 of the tray 60 as shown in FIGS. 9 and 10), the flap portions F1, F2 are prevented from coming off the side walls 62 of the tray 60 inward (i.e., the outermost portions of the pet sheet 1 are moved inward), which prevents the pet's urine from leaking out of the pet sheet 1.
[0093] As shown in FIGS. 1 and 2, the main body 10 is formed in a shape having multiple sides when viewed in the thickness direction Z (in this embodiment, a rectangular shape having four sides), and the adhesive layer 5 is not disposed on an edge portion corresponding to at least one side of the main body 10 (in this embodiment, region E corresponding to both side edges of the main body 10 in the longitudinal direction X). With this configuration, when disposing of (replacing) the pet sheet 1, the pet sheet 1 can be easily detached from the floor surface or the like starting from the edge portion (region E) of the main body 10 where the adhesive layer 5 is not disposed and is not adhered to the floor surface or the like. In other words, the pet sheet 1 can be easily detached from the floor surface or the like by pinching up the edge portion (region E) of the main body 10. This improves user convenience when disposing of the sheet.
[0094] The topsheet 2 and the backsheet 3 are joined to each other in a region (in this embodiment, the flap portion F1) surrounding the absorbent body region A where the absorbent body 4 is disposed. More specifically, as shown in FIG. 6 , in the portion of the flap portion F1 that does not overlap with the flap portion F2 (i.e., on both sides of the absorbent body region A in the short direction Y), a hot melt adhesive (adhesive HA) is provided between the topsheet 2 and the backsheet 3. As an example, the adhesive HA is disposed intermittently along the longitudinal direction X. With this adhesive HA, the topsheet 2 and the backsheet 3 are joined to each other in the portion of the flap portion F1 that does not overlap with the flap portion F2.
[0095] 3, an edge portion corresponding to at least one side of the main body portion 10 (in this embodiment, both side edges of the main body portion 10 in the longitudinal direction X) has a non-bonded region N where the topsheet 2 and the backsheet 3 are not bonded to each other. More specifically, in each flap portion F2, the topsheet 2 and the backsheet 3 are bonded to each other by a hot melt adhesive (adhesives H1, H4) extending in the short direction Y near the center of each flap portion F2 in the longitudinal direction X, and the topsheet 2 and the backsheet 3 are not bonded to each other in the portions where the adhesives H1, H4 are not provided. This makes it possible to roll up the topsheet 2 relative to the backsheet 3 at the outer end portion of the main body portion 10 in the longitudinal direction X.
[0096] According to the above configuration, even if an adhesive layer 5 is arranged on the back surface 3a in the non-bonding area N, the top sheet 2 can be separated from the back sheet 3, so that the pet sheet 1 can be easily pulled away from the floor surface, etc., by grasping the part of the top sheet 2 that is separated from the back sheet 3 in this manner (i.e., the rolled-up part).
[0097] 8(A), the backsheet 3 may have a plurality of convex portions 31 formed from the back surface 3a toward the opposite side of the back surface 3a (the inner surface 3b). The plurality of convex portions 31 may be formed so as to be distributed over the entire backsheet 3, for example, by embossing. In this case, recesses 32 corresponding to the convex portions 31 are formed on the back surface 3a. According to the above configuration, by providing the backsheet 3 with an uneven structure (a plurality of convex portions 31 and recesses 32), blocking and adhesion between the backsheet 3 and the topsheet 2 can be appropriately prevented, and the adhesive layer 5 can be reliably provided on the smooth portion of the back surface 3a excluding the convex portions 31 (the recesses 32 that are recessed as viewed from the back surface 3a), thereby improving the stability and effectiveness of the adhesive layer 5.
[0098] As another example, as shown in Figure 8 (B), the back sheet 3 may have a plurality of convex portions 31 formed from the opposite side of the back surface 3a (inner surface 3b) toward the back surface 3a. In this case, concave portions 32 corresponding to the convex portions 31 are formed on the inner surface 3b side. According to the above configuration, similar to the configuration of Figure 8 (A), by providing the back sheet 3 with an uneven structure, it is possible to appropriately prevent blocking and adhesion between the back sheet 3 and the top sheet 2. Furthermore, by providing the adhesive layer 5 on the tip surface of the convex portions 31 on the back surface 3a, it is possible to prevent the adhesive strength of the back surface 3a from becoming too strong and suppress tearing of the back sheet 3 when the pet pad 1 is used. In the form of (B) in Figure 8, the adhesive layer 5 may also be placed in the area between the convex portions 31. However, even in this case, the adhesive layer 5 placed at the tip of the convex portion 31 that protrudes most outward on the back surface 3a side will mainly come into contact with the floor surface, etc., and the function of the adhesive layer 5 placed between the convex portions 31 can be weakened, thereby achieving the above-mentioned effect (the effect of preventing the adhesive strength of the back surface 3a from becoming too strong).
[0099] 1 and 2, the main body portion 10 is provided with flap portions F where the topsheet 2 and backsheet 3 overlap and which extend outward beyond the outer edge of the absorbent body 4. The first bending resistance when a flap portion F1 (first flap portion) of the flap portion F is provided along at least one side of the main body portion 10 (in this embodiment, two sides extending in the longitudinal direction X) is folded from the backsheet 3 side to the topsheet 2 side along the outer edge 4a (edge along the longitudinal direction X) of the absorbent body 4 is greater than the second bending resistance when the flap portion F1 is folded from the topsheet 2 side to the backsheet 3 side along the outer edge 4a of the absorbent body 4. Here, the first bending resistance is the bending resistance when the flap portion F1 is folded in the direction D1 in FIG. 4. That is, the first bending resistance is an index that takes a larger value as it becomes more difficult to bend the flap portion F1 in direction D1 (in other words, as the repulsive force (bending resistance) generated when bending the flap portion F1 in direction D1 becomes larger). The second bending resistance is the bending resistance when bending the flap portion F1 in direction D2 in FIG. 4. That is, the second bending resistance is an index that takes a larger value as it becomes more difficult to bend the flap portion F1 in direction D2 (in other words, as the repulsive force (bending resistance) generated when bending the flap portion F1 in direction D2 becomes larger).
[0100] The first and second bending resistances can be measured, for example, by a Gurley flexibility test in accordance with JIS L-1085, 1096. As an example, the measurements can be performed as follows. First, as shown in FIG. 11, a sample Sa is obtained by punching out a sample from the pet sheet 1 in the region where the absorbent body 4 is present in the longitudinal direction X so that the area of the portion belonging to the absorbent body region A and the area of the portion belonging to the flap portion F1 are approximately equal. The sample Sa has a width w1 of 38.1 mm in the transverse direction Y and a width w2 of 25 mm in the longitudinal direction X. The sample Sa is then subjected to a Gurley flexibility test, thereby measuring the first and second bending resistances. The bending resistance (first bending resistance) when the flap portion F2 is folded from the backsheet 3 side to the topsheet 2 side along the outer edge (edge along the short direction Y) of the absorbent 4, and the bending resistance (second bending resistance) when the flap portion F2 is folded from the topsheet 2 side to the backsheet 3 side along the outer edge (edge along the short direction Y) of the absorbent 4, can also be measured by the same method. That is, a sample similar to the above sample Sa is obtained in the area of the pet sheet 1 where the absorbent 4 is present in the short direction Y (i.e., a sample having a width of 38.1 mm in the long direction X and a width of 25 mm in the short direction Y, punched so that the area of the portion belonging to the absorbent region A and the area of the portion belonging to the flap portion F2 are approximately equal), and the first bending resistance and the second bending resistance of the flap portion F2 can be measured by performing a similar Gurley flexibility test on the sample. The above first bending resistance and second bending resistance may be measured by a method other than the Gurley flexibility test. For example, as another measurement method, the following "cantilever method" may be used.
[0101] <Cantilever method> 1. Prepare multiple test pieces by overlapping the top sheet 2 and back sheet 3 in the same configuration as the flap portion F1 (for example, a test piece obtained by joining the top sheet 2 and back sheet 3 with an adhesive HA as shown in Figure 6, a rectangular test piece with a width of 25 mm corresponding to the longitudinal direction X and a length of 150 mm corresponding to the transverse direction Y). 2. The test piece is clamped by the cantilever pressure plate so that the length direction of the test piece is parallel to the direction of movement and the back surface 3a of the back sheet 3 faces upward, and the test piece is slid toward the slope at a speed of 5 mm / sec, and the amount of movement (mm) of the test piece when the tip of the test piece touches the slope is measured. 3. For the same test piece, clamp the test piece with the cantilever pressure plate so that the length direction of the test piece is parallel to the direction of movement and the surface 2a of the top sheet 2 faces upward, and slide the test piece toward the slope at a speed of 5 mm / sec, and measure the amount of movement (mm) of the test piece when the tip of the test piece touches the slope. 4. For each of the multiple test pieces, carry out steps 3 and 4 above. 5. The average value of the measurement results of the above "3." for the multiple test pieces is obtained as the first bending resistance, and the average value of the measurement results of the above "4." for the multiple test pieces is obtained as the second bending resistance.
[0102] In this embodiment, in order to confirm that the flap portion F1 along the longitudinal direction X satisfies the above relationship "first bending resistance > second bending resistance", in "1." of the cantilever method, the test piece was prepared so that the length direction of the test piece corresponded to the lateral direction Y. However, in order to confirm that the flap portion F2 along the lateral direction Y satisfies the above relationship "first bending resistance > second bending resistance", in "1." of the cantilever method, the test piece may be prepared so that the length direction of the test piece corresponds to the longitudinal direction X.
[0103] 9 and 10, the effect of configuring the flap portion F1 so that the above-mentioned relationship "first bending resistance > second bending resistance" is established will be described. As shown in FIG. 9, the tray 60 has a placement surface 61 on which the central portion of the main body portion 10 of the pet sheet 1 (the region where the absorber 4 is provided) is placed, and side walls 62 formed to rise from the edges of the placement surface 61. As shown in FIGS. 9 and 10, the pair of flap portions F1 of the pet sheet 1 are arranged so as to abut against the inner surfaces 62a of a pair of side walls 62 facing each other in the short direction Y. Because the above-mentioned relationship "first bending resistance > second bending resistance" is established for the flap portion F1, when the flap portion F1 is folded from the backsheet 3 side toward the topsheet 2 side along the outer edge portion 4a of the absorber 4 and arranged along the inner surfaces 62a of the side walls 62 of the tray 60, the flap portion F1 is suitably pressed against the side walls 62 of the tray 60. As a result, the adhesion between the flap portion F1 and the side wall 62 of the tray 60 can be improved, and gaps between the flap portion F1 and the side wall 62 of the tray 60 can be prevented. Therefore, when the pet sheet 1 is placed on the tray 60 for use, the pet sheet 1 can prevent urine leakage between the pet sheet 1 and the tray 60 (side wall 62) and improve the slippage resistance of the pet sheet 1. Furthermore, when the pet sheet 1 is placed on the floor, the flap portion F1 can be prevented from lifting off the floor (which would result in the pet sheet 1 being more likely to slip off the floor). Note that, from the viewpoint of more suitably achieving the above-mentioned effect, it is preferable that the relationship "first bending resistance > second bending resistance" be established not only for the pair of flaps F1 along the longitudinal direction X but also for the pair of flaps F2 along the lateral direction Y. In the pet sheet 1 of this embodiment, the "first bending resistance > second bending resistance" is established for all four sides (i.e., the two flap portions F1 on both sides in the short direction Y and the two flap portions F2 on both sides in the long direction X). This allows all sides (edges) of the pet sheet 1 to achieve the above-mentioned effects (i.e., the effects of closely adhering the flap portions F1, F2 to the side wall 62 of the tray 60 and preventing the flap portions F1, F2 from lifting up from the floor surface).As a result, the pet sheet 1 can be suitably prevented from slipping off the tray, floor surface, or the like.
[0104] The above-mentioned flap portions F1 (i.e., flap portions F for which the above-mentioned relationship "first bending resistance > second bending resistance" is established) are provided at least along each of a pair of opposing sides of the absorbent 4 (in this embodiment, a pair of opposing sides in the short direction Y). With the above configuration, as shown in FIG. 9, when the pet sheet 1 is placed on a rectangular tray 60, each of the pair of flap portions F1 of the pet sheet 1 can be suitably pressed against the pair of opposing side walls 62 of the tray 60. This further improves the adhesion of the pet sheet 1 to the tray 60 and suitably prevents the pet sheet 1 from shifting position relative to the tray 60. As a result, urine leakage between the pet sheet 1 and the tray 60 can be more effectively prevented.
[0105] The thickness of the topsheet 2 (the length from the front surface 2a to the inner surface 2b) is preferably 0.9 mm or more and less than 2 mm. According to the above configuration, by ensuring a thickness of the topsheet 2 of 0.9 mm or more, it is possible to prevent the flap portion F1 from bending from the backsheet 3 side to the topsheet 2 side along the outer edge portion 4a of the absorber 4. Furthermore, by keeping the thickness of the topsheet 2 to less than 2 mm, it is possible to prevent the pet sheet 1 from becoming too heavy. Therefore, by setting the thickness of the topsheet 2 within the above range, it is possible to improve the adhesion of the flap portion F1 to the tray 60 (side wall 62) and prevent the pet sheet 1 from becoming too heavy.
[0106] As shown in FIG. 4, the portion of the topsheet 2 where the flap portion F1 is provided has a step portion 21 that bends along the outer edge 4a of the absorbent body 4. More specifically, the absorbent body 4 has a thickness greater than that of the topsheet 2 and the backsheet 3, and the topsheet 2 has a portion that extends in the thickness direction Z along the side of the absorbent body 4 that is aligned with the outer edge 4a of the absorbent body 4. This forms the step portion 21 as shown in FIG. 4. This configuration makes it possible to suitably prevent the flap portion F1 from bending from the backsheet 3 side to the topsheet 2 side along the outer edge 4a of the absorbent body 4. From the perspective of suitably forming the step portion 21 described above, it is preferable that the topsheet 2 be made of an air-through nonwoven fabric.
[0107] Surface sheet 2 basis weight (g / m 2 ) is the basis weight of the back sheet 3 (g / m 2 ) is preferably larger than the above. According to the above configuration, it is possible to suitably prevent the flap portions F1, F2 from bending from the backsheet 3 side to the topsheet 2 side along the outer edge portion 4a of the absorbent core 4.
[0108] 5 is a schematic diagram showing an enlarged view of a portion of the topsheet 2 included in the range P in FIG. 4. As shown in FIG. 5, the fiber density of the first region R1 on the front surface 2a side of the topsheet 2 is preferably higher than the fiber density of the second region R2 on the inner surface 2b side of the topsheet 2. According to the above configuration, by making the first region R1 of the topsheet 2 (the region farther from the backsheet 3) a high-density region, it is possible to suitably prevent the flap portion F1 from bending from the backsheet 3 side toward the topsheet 2 side along the outer edge 4a of the absorbent core 4. In other words, by making the rigidity of the first region R1 higher than the rigidity of the second region R2, it is possible to strengthen the repulsive force generated in the opposite direction when attempting to fold the flap portion F1 from the backsheet 3 side toward the topsheet 2 side.
[0109] The flap portion F1 has fold lines L1 and L2 for folding the main body portion 10 so that the back surface 3a of the backsheet 3 faces outward, along a first direction (in this embodiment, the short direction Y) in which the flap portion F1 extends outward from the outer edge portion 4a of the absorbent body 4. According to the above configuration, as shown in FIG. 10 , when the flap portion F1 is folded from the backsheet 3 side toward the topsheet 2 side along the outer edge portion 4a of the absorbent body 4 and placed along the side wall 62 of the tray 60, a convex portion (a part of the flap portion F1 located on the fold lines L1 and L2) is formed that convex toward the side wall 62 of the tray 60 along the fold lines L1 and L2 of the flap portion F1. The convex portion is pressed against the side wall 62 of the tray 60, thereby further improving the adhesion of the pet sheet 1 to the tray 60. In addition, in this embodiment, multiple (two in this embodiment) folding lines L1, L2 are arranged spaced apart from each other in the second direction (longitudinal direction X in this embodiment) perpendicular to the thickness direction Z and the first direction (transverse direction Y in this embodiment), so that multiple protrusions can be formed. As a result, the adhesion of the pet sheet 1 to the tray 60 can be further improved.
[0110] As shown in FIGS. 1, 6, and 7, adhesives H1-H4 (first adhesives) are disposed on the main body portion 10, extending linearly across the entire area of the main body portion 10 along the first direction (transverse direction Y). As shown in FIG. 6, the adhesives H1-H4 are disposed between the topsheet 2 and the backsheet 3 in the flap portion F1. Meanwhile, as shown in FIG. 7, the adhesives H1-H4 are disposed between the absorbent body 4 and the backsheet 3 in the region overlapping with the absorbent body 4. As shown in FIG. 1, the adhesives H1-H4 are disposed so as not to overlap with the fold lines L1, L2. According to the above configuration, by disposing the fold lines L1, L2 and the adhesives H1-H4, which all extend along the first direction (transverse direction Y), so that they do not overlap with each other, it is possible to avoid interference between the fold lines L1, L2 and the adhesives H1-H4. This makes it possible to prevent the main body portion 10 from bending in an unintended direction due to the influence of the adhesives H1 to H4 when folding the main body portion 10 along the folding lines L1 and L2.
[0111] However, at least one of the adhesives H1-H4 may be disposed so as to overlap at least one of the fold lines L1, L2. According to the above configuration, by overlapping one of the adhesives H1-H4 with one of the fold lines L1, L2, the shape of the flap portion F1 is more easily maintained in the portion overlapping with the fold line (either fold line L1 or L2 that overlaps with one of the adhesives H1-H4). As a result, the adhesion of the flap portion F1 to the side wall 62 of the tray 60 can be improved.
[0112] 6, an adhesive HA (second adhesive) is disposed between the topsheet 2 and the backsheet 3 in the flap portion F1. According to the above configuration, the topsheet 2 and the backsheet 3 in the flap portion F1 are bonded to each other by the adhesive HA, which makes it easier to maintain the shape of the flap portion F1. As a result, the adhesion of the flap portion F1 to the sidewall 62 of the tray 60 can be improved.
[0113] 7, in this embodiment, the adhesive HA is disposed so as to straddle the outer edge 4a of the absorbent body 4 along the flap portion F1. More specifically, the adhesive HA is disposed in the region A3 shown in FIG. 1. That is, the adhesive HA is disposed not only in the flap portion F1 but also in the region where the absorbent body 4 is disposed in the short-side direction Y. The portion of the adhesive HA that overlaps with the absorbent body 4 is disposed between the topsheet 2 and the absorbent body 4. According to the above configuration, by fixing the portion of the topsheet 2 that continues from the flap portion F1 to the absorbent body 4, the shape stability of the flap portion F1 can be further improved. As a result, the adhesion of the flap portion F1 to the side wall 62 of the tray 60 can be further improved.
[0114] (packaging) 12, an example of a package (packaging 100) that houses a plurality of overlapping pet sheets 1 will be described. The packaging 100 is configured to house a plurality of pet sheets 1 (for example, five sheets) and may be made of, for example, a film. A first pet sheet (for example, the pet sheet 1 arranged in the top row in FIG. 12) and a second pet sheet (for example, the pet sheet 1 arranged in the second row from the top in FIG. 12) that are adjacent to each other within the packaging 100 are arranged so that a portion of the back surface 3a of the first pet sheet and a portion of the back surface 3a of the second pet sheet face each other and come into contact with each other. In this embodiment, each pet sheet 1 is folded in thirds along the fold lines L1 and L2 so that the back surface 3a side of the back surface sheet 3 is mountain-folded, and then arranged side by side, so that the back surfaces 3a of adjacent pet sheets 1 face each other as described above. Here, an adhesive layer 5 is provided on at least one of a portion of the back surface 3a of the first pet sheet 1 (a portion facing the back surface 3a of the second pet sheet) and a portion of the back surface 3a of the second pet sheet (a portion facing the back surface 3a of the first pet sheet). In this embodiment, as shown in FIG. 2, the adhesive layer 5 is provided on substantially the entire back surface 3a of the pet sheet 1 (an area excluding an area E on the edge in the longitudinal direction X). Therefore, when multiple pet sheets 1 are arranged as shown in FIG. 12, the adhesive layer 5 is provided on both a portion of the back surface 3a of the first pet sheet 1 and a portion of the back surface 3a of the second pet sheet 1. In other words, the adhesive layers 5 of adjacent pet sheets 1 face and come into contact with each other.
[0115] If vibrations or impacts are applied to the packaging 100 during transportation, etc., some of the pet sheets 1 in the packaging 100 may become misaligned, resulting in deformation of the main body 10 of the pet sheets 1. Due to such deformation of the main body 10, the back surface 3a of the pet sheet 1 may not properly contact the floor or other surface during use, making the pet sheet 1 more likely to shift. In other words, deformation of the pet sheet 1 during transportation of the packaging 100 may impair the effects of the pet sheet 1 described above. In response to this, the packaging 100 contains adjacent first and second pet sheets so that their back surfaces 3a face and contact each other via the adhesive layer 5. This prevents adjacent pet sheets 1 from shifting positions within the packaging 100, even when vibrations or impacts are applied to the packaging 100, making it less likely for each pet sheet 1 to deform within the packaging 100. As a result, when the pet sheet 1 is taken out of the packaging body 100 and used, it is possible to prevent the pet sheet 1 from slipping off the floor surface or the like.
[0116] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. The materials and shapes of each component are not limited to those described above, and various materials and shapes can be used. Furthermore, some components included in the configurations of the above embodiments may be modified or omitted, or other components may be added. [Explanation of symbols]
[0117] 1...pet sheet, 2...top sheet, 2a...top surface (first surface), 2b...inner surface (second surface), 3...back sheet, 3a...back surface, 4...absorbent body, 4a...outer edge portion, 5...adhesive layer, 10...main body portion, 21...step portion, 31...convex portion, 51...adhesive region (first adhesive region), 52...adhesive region (second adhesive region), 100...packaging body, A...absorbent body region, A1...first region, A2...second region, B...boundary portion, F, F2...flap portion, F1...flap portion (first flap portion), H1 to H4...adhesive (first adhesive), HA...adhesive (second adhesive), L, L1, L2...fold line, N...non-bonded region, R1...first region, R2...second region.
Claims
1. A main body portion includes a liquid-permeable top sheet, a back sheet, and an absorbent body disposed between the top sheet and the back sheet, an adhesive layer having adhesive properties is provided in at least a partial area of the back surface of the back sheet on the side opposite to the top sheet side; The pet sheet, wherein the peel strength required to separate the adhesive layers adhered to each other is smaller than the tensile strength of the back sheet.
2. The pet sheet according to claim 1 , wherein the adhesive layer is made of a polyurethane resin.
3. The pet sheet according to claim 2, wherein the coefficient of static friction when the portions of the back surface on which the adhesive layer is provided are brought into surface contact with each other is 0.35 or more.
4. The main body portion has a fold line for folding the main body portion, The pet sheet according to claim 1 , wherein the adhesive layer is disposed in a first region adjacent to the fold line on one side of the fold line.
5. The pet sheet according to claim 4 , wherein the adhesive layer is also disposed in a second region adjacent to the fold line on the opposite side of the fold line from the first region.
6. The pet sheet according to claim 1 , wherein the adhesive layer is disposed in an area of the absorbent body that overlaps with the absorbent body.
7. The pet sheet according to claim 1 , wherein the adhesive layer is disposed in a flap region at an outer edge of the main body portion where the absorbent body is not disposed.
8. the main body is formed in a shape having a plurality of sides when viewed in a thickness direction of the main body, The pet sheet according to claim 1 , wherein the adhesive layer is not disposed on an edge portion corresponding to at least one side of the main body portion.
9. the main body is formed in a shape having a plurality of sides when viewed in a thickness direction of the main body, the top sheet and the back sheet are joined to each other in a region surrounding the region where the absorbent body is disposed, The pet sheet according to claim 1, wherein an edge portion corresponding to at least one side of the main body portion is provided with a non-bonded region where the top sheet and the back sheet are not bonded to each other.
10. The pet sheet according to claim 1 , wherein the back sheet has a plurality of convex portions formed from the back surface side toward the opposite side of the back surface.
11. The pet sheet according to claim 1 , wherein the back sheet has a plurality of convex portions formed from the opposite side of the back surface toward the back surface side.
12. The pet sheet according to claim 1 , wherein the peel strength is less than 10% of the tensile strength.
13. The main body portion is provided with a flap portion where the top sheet and the back sheet overlap and which extends outward beyond the outer edge of the absorbent body, The pet sheet of claim 1, wherein the first flap portion of the flap portion arranged along at least one side of the main body portion has a first bending resistance when folded from the back sheet side to the top sheet side along the outer edge of the absorbent body, which is greater than the second bending resistance when the first flap portion is folded from the top sheet side to the back sheet side along the outer edge of the absorbent body.
14. The main body is formed in a rectangular shape when viewed in a thickness direction of the main body, The pet sheet according to claim 13, wherein the first flap portions are provided at least along each of a pair of opposing sides of the absorber.
15. 14. The pet sheet according to claim 13, wherein the thickness of the top sheet is 0.9 mm or more and less than 2 mm.
16. The pet sheet according to claim 13, wherein a step portion that bends along the outer edge of the absorber is provided in a portion of the topsheet where the first flap portion is provided.
17. The pet sheet according to claim 16, wherein the top sheet is formed of an air-through nonwoven fabric.
18. The pet sheet according to claim 13, wherein the surface sheet has a basis weight greater than the back sheet.
19. The top sheet has a first surface opposite to the back sheet side and a second surface on the back sheet side, The pet sheet according to claim 13, wherein a fiber density of a first region on the first surface side of the topsheet is higher than a fiber density of a second region on the second surface side of the topsheet.
20. The pet sheet described in claim 13, wherein the first flap portion has a fold line for folding the main body portion along a first direction in which the first flap portion extends outward from the outer edge portion of the absorbent body so that the back surface of the back sheet opposite the top sheet side is facing outward.
21. The pet sheet according to claim 20, wherein the plurality of folding lines are spaced apart from one another in a thickness direction of the main body and in a second direction perpendicular to the first direction.
22. The folding line is provided over the entire area of the main body portion along the first direction, a first adhesive is disposed on the main body portion, the first adhesive extending linearly across the entire main body portion along the first direction; the first adhesive is disposed between the top sheet and the back sheet in the first flap portion, and is disposed between the absorbent body and the back sheet in the region overlapping with the absorbent body, The pet sheet according to claim 20 or 21, wherein the first adhesive is disposed so as not to overlap the folding line.
23. The folding line is provided over the entire area of the main body portion along the first direction, a first adhesive is disposed on the main body portion, the first adhesive extending linearly across the entire main body portion along the first direction; the first adhesive is disposed between the top sheet and the back sheet in the first flap portion, and is disposed between the absorbent body and the back sheet in the region overlapping with the absorbent body, The pet sheet according to claim 20 or 21, wherein the first adhesive is disposed so as to overlap the fold line.
24. The pet sheet according to claim 13, wherein a second adhesive is disposed between the top sheet and the back sheet in the first flap portion.
25. the second adhesive is disposed so as to straddle the outer edge portion of the absorbent body along the first flap portion, The pet sheet according to claim 24, wherein the portion of the second adhesive that overlaps with the absorbent body is disposed between the topsheet and the absorbent body.
26. the adhesive layer has a first adhesive region having a first adhesive strength and a second adhesive region having a second adhesive strength smaller than the first adhesive strength; The pet sheet according to claim 1 , wherein a boundary portion is formed between the first adhesive region and the second adhesive region.
27. A packaging body containing a plurality of pet sheets stacked on top of each other, Each of the plurality of pet sheets includes a main body portion having a liquid-permeable top sheet, a back sheet, and an absorbent body disposed between the top sheet and the back sheet, an adhesive layer having adhesive properties is provided in at least a partial area of the back surface of the back sheet on the side opposite to the top sheet side; The peel strength required to separate the adhesive layers adhered to each other is smaller than the tensile strength of the back sheet, The first pet sheet and the second pet sheet adjacent to each other in the packaging body are arranged so that a part of the back surface of the first pet sheet and a part of the back surface of the second pet sheet face each other and come into contact with each other, The packaging body, wherein the adhesive layer is provided on at least one of a portion of the back surface of the first pet sheet and a portion of the back surface of the second pet sheet.
Citation Information
Patent Citations
Sheet for excretion of pet
JP1999332413A