JP7709261B2 - Hook sheets and sheet rolls - Google Patents

Description

The present invention relates to a hook sheet and a sheet roll.

Patent Document 1 discloses a method for manufacturing an adhesive closure component, for example, for use in baby diapers. Specifically, it states that "in accordance with the disclosure of claim 1, the interlocking means is composed of a shaft having an enlarged portion at its end, and a silicon-containing separating or barrier layer is applied to the cavity of the enlarged portion forming a reinforcement for each interlocking head, and the shaft is essentially held free by the silicon-containing separating or barrier layer, and the fact that little material is added to the silicon-containing separating or barrier layer and/or separation control means makes it possible to achieve an effective desired winding and unwinding characteristic structure for the band-shaped adhesive closure structure." Hook sheets such as adhesive closure components are wound and stored as sheet rolls. In the state of the sheet roll, the interlocking means (hook portion) of the hook sheet is adhered to the adhesive layer, and when the hook sheet is unwound from the sheet roll, the hook portion is peeled off from the adhesive layer.

Patent No. 4638107

When a hook sheet is applied to sanitary products such as diapers, the flexibility of the hook sheet is very important, and making the hook sheet thinner is advantageous in improving flexibility. However, making the hook sheet thinner makes it more susceptible to problems with peeling when unrolling the sheet from the sheet roll, making it difficult to ensure stable quality when unrolling the hook sheet from the sheet roll.

A hook sheet according to one aspect of the present invention comprises a substrate, a plurality of hook portions provided on one surface of the substrate, and an adhesive layer provided on the other surface of the substrate, wherein the hook portions comprise a post portion standing from the substrate and a head portion provided at the tip of the post portion, the thickness of the substrate is 35 μm or more and 70 μm or less, and when the substrate is viewed in a plan view, the area of the heads per ^cm2 of the substrate is 15,000,000 ^μm2 or more and 23,000,000 ^μm2 or less.

The thickness of the substrate is 35 μm or more, so that it can maintain shape stability, and 70 μm or less, so that it can maintain the flexibility required for use in sanitary products, etc. In addition, the head area per ^cm2 of the substrate is 15,000,000 ^μm2 or more, so that it is easy to obtain an appropriate engagement force when it engages with other engagement parts to function as a mechanical fastener. Furthermore, the head area per ^cm2 of the substrate is 23,000,000 ^μm2 or less, so that it is unlikely to be overloaded when peeling off from the adhesive layer. As a result, it is easy to ensure stable quality when the hook sheet is unwound from the sheet roll.

A sheet roll according to one aspect of the present invention is formed by winding a hook sheet, the hook sheet comprising a substrate, a plurality of hook portions provided on one surface of the substrate, and an adhesive layer provided on the other surface of the substrate, the hook portions comprising a post portion standing from the substrate and a head portion provided at the tip of the post portion, the thickness of the substrate being 35 μm or more and 70 μm or less, and when the substrate is viewed in a plan view, the area of the head portion per ^cm2 of the substrate being 15,000,000 ^μm2 or more and 23,000,000 ^μm2 or less.

This sheet roll makes it easier to ensure consistent quality when unwinding the hook sheet from the sheet roll.

According to one aspect of the present invention, it becomes easier to ensure stable quality when unwinding a hook sheet from a sheet roll.

FIG. 1 is a perspective view of a sheet roll according to an embodiment. FIG. 2 is a cross-sectional view taken along line II-II in FIG. FIG. 3 is an enlarged view of the hook portion, (a) being a side view and (b) being a plan view. FIG. 1 is a perspective view of a diaper having ear members, showing an example of a hygiene product.

A hook sheet according to one aspect of an embodiment comprises a substrate, a plurality of hook portions provided on one surface of the substrate, and an adhesive layer provided on the other surface of the substrate, wherein the hook portions comprise a post portion standing from the substrate and a head portion provided at the tip of the post portion, the thickness of the substrate is 35 μm or more and 70 μm or less, and when the substrate is viewed in a plan view, the area of the head portion per ^cm2 of the substrate is 15,000,000 ^μm2 or more and 23,000,000 ^μm2 or less.

The thickness of the substrate is 35 μm or more, so that it can maintain shape stability, and 70 μm or less, so that it can maintain the flexibility required for use in sanitary products, etc. In addition, the head area per ^cm2 of the substrate is 15,000,000 ^μm2 or more, so that it is easy to obtain an appropriate engagement force when it engages with other engagement parts to function as a mechanical fastener. Furthermore, the head area per ^cm2 of the substrate is 23,000,000 ^μm2 or less, so that it is unlikely to be overloaded when peeling off from the adhesive layer. As a result, it is easy to ensure stable quality when the hook sheet is unwound from the sheet roll.

In the above hook sheet, a SUS steel plate that has been cold-rolled and then bright heat-treated as a surface finish is used as the test plate, and the test plate has a surface roughness of 50±25 μm as an arithmetic mean roughness. When the hook sheet is adhered to the test plate and pulled in a direction perpendicular to the test plate, the adhesive strength of the adhesive layer may be 4 N/cm or more and 10 N/cm or less. When a sheet roll is formed, it becomes easier to ensure the desired adhesive strength while reducing the load required to unwind the hook sheet.

The head of the hook member may have an overhang that protrudes from the post portion, and the overhang may have a protruding dimension of 70 μm or more and 120 μm or less. This makes it easier to ensure the desired engagement force when functioning as a mechanical fastener.

The overhang may extend in both directions opposite to the post portion. By extending in both directions, when the hook portion engages with another engaging portion as a mechanical fastener, the engagement is not biased from one side only, but is engaged from both sides, reducing unevenness in the engagement state.

The thickness of the substrate may be 45 μm or more. This is advantageous in ensuring strength stability when unwound from the sheet roll.

The substrate may include a polyolefin.

A sheet roll according to one aspect of the embodiment is formed by winding a hook sheet, the hook sheet comprising a substrate, a plurality of hook portions provided on one side of the substrate, and an adhesive layer provided on the other side of the substrate, the hook portions comprising a post portion standing from the substrate and a head portion provided at the tip of the post portion, the thickness of the substrate being 35 μm or more and 70 μm or less, and when the substrate is viewed in a plan view, the area of the head portion per ^cm2 of the substrate being 15,000,000 ^μm2 or more and 23,000,000 ^μm2 or less.

This sheet roll makes it easier to ensure consistent quality when unwinding the hook sheet from the sheet roll.

The hook sheet may be wound so that the adhesive layer faces inward, closer to the core, and the hook portion faces outward, farther from the core. The outermost surface becomes the hook portion, making it easier to handle.

The following describes the embodiments in detail with reference to the accompanying drawings. In the description of the drawings, the same or equivalent elements are given the same reference numerals, and duplicate descriptions are omitted.

As shown in FIG. 1, the hook sheet 1 according to the embodiment is wound around a core 10a in multiple layers to form a sheet roll 10, which is maintained, stored, etc. When applied to a sanitary product such as a diaper 100, the hook sheet 1 is pulled out from the sheet roll 10 by a processing device or the like. The sheet roll 10 is cut into a predetermined shape that can be applied to the ear portion 101 of the disposable diaper 100, for example, and adhered to the ear portion 101. The hook sheet 1 has hook portions 3, which are removably fixed by engaging with engaging portions 105 provided on another portion of the diaper 100 (see FIG. 4), forming a mechanical fastener.

As shown in FIG. 2, the hook sheet 1 comprises a substrate 2, a hook portion 3 provided on one surface of the substrate 2, and an adhesive layer 4 provided on the other surface of the substrate 2. The hook portion 3 corresponds to one of the pair of engaging portions 105, 101a that form a mechanical fastener, 101a. The mechanical fastener broadly includes structures called, for example, hook and loop fasteners, and refers to a fastener that can be attached and detached surface-wise. In contrast to the hook portion 3, which is one of the engaging portions, the other engaging portion 105 is a loop or the like (not shown) that physically engages with the hook portion 3.

The substrate 2 is in the form of a sheet whose thickness is thinner than its width. The substrate 2 is formed from a resin material such as poly(ethylene terephthalate), polyamide such as nylon, poly(styrene-acrylonitrile), poly(acrylonitrile-butadiene-styrene), polyolefin such as polypropylene, plasticized PVC, or polyester. The thickness t1 of the substrate 2 is 35 μm or more and 70 μm or less. The thickness t1 of the substrate 2 may be 45 μm or more, or 50 μm or more. The thickness t1 of the substrate 2 may be 60 μm or less, or 50 μm or less.

As shown in Figures 2 and 3, the hook portion 3 has a column portion 31 standing upright from the base material 2, and a head portion 32 provided at the tip of the column portion 31. The head portion 32 protrudes laterally from the column portion 31, and in particular has an overhang 32a that protrudes in both opposing directions. By providing the overhang 32a, it engages with and is held by the other engagement portion 105 (see Figure 4). The larger the protrusion dimension d of the overhang 32a, the stronger the engagement force tends to be.

The arrangement of the multiple hook portions 3 on the base material 2 may be regular, such as a lattice or staggered pattern, or may be irregular and random. Examples of materials used for the hook portions 3 include poly(ethylene terephthalate), polyamides such as nylon, poly(styrene-acrylonitrile), poly(acrylonitrile-butadiene-styrene), polyolefins such as polypropylene, plasticized PVC, and polyester. The hook portions 3 may be made of the same material as the base material 2 or a different material, and may be formed integrally with the base material 2. The density at which the hook portions 3 are arranged may be, for example, about 500 to 5,000, about 800 to 4,000, or about 1,000 to 3,000 per square inch (25.4 mm square).

The adhesive layer 4 may be made of, for example, a synthetic rubber adhesive. The adhesive layer 4 may have an adhesive strength that allows the hook sheet 1 to adhere to a desired member such as the ear portion 101. For example, the adhesive strength may be 4 N/cm or more and 10 N/cm or less. This range of adhesive strength expands the range of applications in which the desired member can be adhered to without the need for additional adhesives or the like. The adhesive strength may be 5 N/cm or more and 8 N/cm or less, or 5 N/cm or more and 7 N/cm or less. As a supplement, if the adhesive strength is weak in relation to the object to be adhered, the adhesive strength may be appropriately reinforced by applying an adhesive or the like.

Here, the method for measuring the adhesive strength of the adhesive layer 4 will be described. When measuring the adhesive strength, the method for measuring adhesive strength specified by JIS is carried out (JIS Z 0237). In detail, a test plate specified by JIS G4305 is used as the test plate to which the hook sheet 1 is adhered. In other words, a SUS steel plate that has been cold-rolled and then bright heat-treated as a surface finish is used as the test plate. The surface roughness of this test plate is an arithmetic mean roughness of 50±25 μm. When measuring the adhesive strength, a hook sheet 1 of a predetermined dimension is adhered to the test plate. Next, using a device equivalent to the tensile test device specified by JIS, the hook sheet 1 is pulled in a direction perpendicular to the test plate, and the adhesive strength is measured.

The thickness t2 of the adhesive layer 4 may be 300 μm or less. One reason why the thickness t2 is 300 μm or less is to balance it with the thickness t1 of the base material 2. The thickness t2 of the adhesive layer 4 may be 5 μm or more. One reason why the thickness t2 is 5 μm or more is that it is a thickness that can function as the adhesive layer 4 and also has manufacturing stability.

Next, the dimensional relationship of the hook portion 3 will be described with reference to Figure 3. The dimension h from the surface of the base material 2 to the tip of the hook portion 3 (the apex of the head 32) may be 100 to 800 μm. One reason for this dimension being 100 μm or more is to ensure the engagement force required for a mechanical fastener. One reason for this dimension being 800 μm or less is to reduce discomfort (e.g. pain) when touched by a finger, etc.

The maximum dimension La of the outer diameter of the head 32 of the hook portion 3 may be 100 to 1000 μm, or 200 to 500 μm. If this dimension La is 200 μm or more, it becomes easier to engage with other engaging portions 105 that have fibrous loops or the like when functioning as a mechanical fastener. If this dimension La is 500 μm or less, it becomes easier to penetrate into the fibers of other engaging portions 105.

In particular, the overhang dimension d of the overhang 32a of the head 32 may be 70 μm or more and 120 μm or less. By having this dimension d of 70 μm or more, it is possible to tightly engage with the fibers of the other engaging portion 105, further improving the retention and stability during engagement. Furthermore, if this dimension La is 500 μm or less, the overhang 32a will be more likely to enter the loop-shaped fibers of the other engaging portion 105. Furthermore, the dimension d may be 90 μm or more and 100 μm or less.

The thickness t3 of the head 32 of the hook portion 3 may be 10 to 200 μm or 30 to 150 μm. By making this thickness t3 30 μm or more, it is possible to maintain an engaged state with the fibers of the other engaging portion 105. By making this thickness t3 150 μm or less, it is possible to penetrate into the fibers of the other engaging portion 105.

The minimum dimension Lb of the outer diameter of the base portion 31 of the hook portion 3 may be 50 to 500 μm or 100 to 300 μm. By making this dimension Lb 100 μm or more, the posture of the hook portion 3 can be maintained. By making this dimension Lb 300 μm or less, the dimension between the outer edge of the head portion 32 can be secured, making it easier to engage the fibers of the other engagement portion 105 with the head portion 32.

The above-mentioned various dimensions may be set appropriately within the scope of the invention depending on various factors such as the size and density of the hook portion 3 and the type of other engaging portions. The height of all the hook portions 3 may be the same (variations within the range of manufacturing errors are allowed), or the height may differ between some areas and other areas. The shape of the hook portions 3 may also be set appropriately, for example, it may be circular or polygonal instead of elliptical.

Next, the solution applied to the ear portion 101 of the diaper 100 will be described with reference to FIG. 4. The diaper 100 is an open-type diaper 100, which is an example of a hygiene product.

The diaper 100 has a rectangular main body 102 that includes an outer liquid-impermeable polymer film and an inner liquid-absorbent layer. The main body 102 is the part that covers the crotch of the wearer, such as an infant. Both sides of the main body 102 are provided with stretchable gathers 102a that are formed with irregular pleats.

A ventral fixing part 103 that contacts the wearer's abdomen (lower abdomen) is provided at one end of the main body 102 in the longitudinal direction, and a dorsal fixing part 104 that contacts the wearer's back (lower back) is provided at the other end. In the ventral fixing part 103 and dorsal fixing part 104, the side that contacts the wearer is the inside, and the opposite side is the outside.

The engaging portion 105 of the mechanical fastener is fixed to the outer surface of the ventral fixing portion 103 so as to cover a wide range in the width direction. Ear portions 101 are provided on both sides in the width direction of the dorsal fixing portion 104. The ear portions 101 are provided with engaging portions 101a that engage with the engaging portions 105 to form the mechanical fastener. The engaging portions 101a of the ear portions 101 are formed by processing the hook sheet 1 to match the shape of the ear portions 101 and adhering it to a predetermined position of the ear portions 101.

The diaper 100 is put on the wearer so that the main body part 102 covers the crotch area of the wearer, and further the ventral fixing part 103 is arranged so as to contact the lower abdomen area of the wearer, and the dorsal fixing part 104 is arranged so as to contact the waist area of the wearer. Next, the diaper 100 is put on by pulling the left and right ear parts 101 and attaching the engagement parts 101a of the ear parts 101 to the engagement parts 105 of the ventral fixing part 103.

The load required when the above-mentioned engaging portion 101a (hook sheet 1) is engaged with another engaging portion 105 forming a mechanical fastener, and then when the two are separated by peeling them off, is the engaging force. For example, the engaging force generated between the hook sheet 1 and the other engaging portion 105 according to this embodiment is 0.35 N/cm or more. If the engaging force is 0.35 N/cm or more, stable fixation is possible when the hook sheet 1 and the other engaging portion 105 are engaged as a mechanical fastener. In addition, the engaging force can be 0.7 N/cm or more, or 1.0 N/cm or more. On the other hand, the engaging force can be 2.0 N/cm or less to facilitate ease of separation.

Here, the method for measuring the engagement force will be described. The engagement force was measured by the following procedure. A loop test piece with a length of 100 mm and a width of 50 mm was placed on a 90-degree shearing jig with the non-peeling surface facing the jig. The hook surface (surface with the hook portion) of a sample test piece with a length of 20 mm and a width of 25 mm having a hook portion was placed facing the loop test piece (the test piece of the other engagement portion), and the hook sample test piece was gently placed on the loop test piece. In addition, the surface with which the hook test piece contacts in the 90-degree shearing jig is smoothed. A 2.0 kg hand roller was slowly rolled on the hook surface in the width direction at about 300 mm/min to make one revolution. Next, a clip was attached on the end of the paper leader of the hook sample test piece. A 1 kg weight was hung on the clip for 2 seconds, and then the weight and clip were removed. Next, the loop test piece was placed in the 90-degree peeling jig, and the paper end of the hook sample test piece was placed in the upper opening of the tensile tester. The end of the hook of the hook sample test piece was placed directly below the upper opening. A peel test was performed while pressing down so that the loop test piece did not move, and the engagement force was measured.

Next, the sheet roll 10 will be described with reference to FIG. 1. The sheet roll 10 is formed, for example, by winding the hook sheet 1 around a core 10a. In this embodiment, the sheet roll 10 is formed by winding the hook sheet 1 around the core 10a. The core 10a may be omitted.

The hook sheet 1 is wound around the core 10a multiple times so that the inner side closer to the core 10a is the adhesive layer 4 and the outer side farther from the core 10a is the hook portion 3. As a result, the hook portion 3 is disposed on the outer surface that is the outermost periphery of the sheet roll 10, and the adhesive layer 4 is disposed on the inner surface of the outermost periphery. As a result, the sheet roll 10 becomes easier to handle when it is transported or when it is placed in a predetermined position in a processing device.

In the state of the sheet roll 10, the adhesive layer 4 of the hook sheet 1 is adhered to the head 32 of each hook portion 3. Therefore, when unrolling the hook sheet 1 from the sheet roll 10, it is necessary to pull out the hook sheet 1 while peeling off the adhesion between the head 32 of each hook portion 3 and the adhesive layer 4. The force required for this is the unrolling force. If the unrolling force is too strong, the hook portion 3 will be overloaded, causing deformation or damage. The magnitude of the unrolling force depends on, for example, the area of the head 32 per ^cm2 of the substrate 2.

If this area is large, the area adhered to the adhesive layer 4 will also be large, and a strong unwinding force will be required. If the unwinding force is too strong, the hook portion 3 will be overloaded, causing deformation or damage. As a result, the manufacturing stability for processing the hook sheet 1 into a predetermined shape will be lacking, and it will be difficult to ensure stable quality when unwinding the hook sheet 1 from the sheet roll 10. Conversely, a narrow area of the head 32 per ^cm2 of the substrate 2 means that the head 32 is likely to be small. If the head 32 is too small, then the engagement force when functioning as a mechanical fastener will be weak, and the stability of the quality as a mechanical fastener will decrease.

In the hook sheet 1 according to the present embodiment, when the substrate 2 is viewed in plan from the hook portion 3 side, the area of the head 32 per 1 cm ² of the substrate 2 is 15,000,000 μm ² or more and 23,000,000 μm ² or less. Since this area is 23,000,000 μm ² or less, it is difficult to overload the substrate 2 when peeling it off from the adhesive layer 4. As a result, it is easy to ensure stable quality when the hook sheet 1 is unwound from the sheet roll 10. In addition, since the area of the head 32 per 1 cm ² of the substrate 2 is 15,000,000 μm ² or more, it is also advantageous in terms of the stability of quality in functioning as a mechanical fastener. Specifically, in this embodiment, the area of the head 32 per 1 cm ² of the substrate 2 is 15,000,000 μm ² or more, and as described above, it is easy to adjust the engagement force to 0.35 N/cm or more. As a result, when the hook sheet 1 and the other engaging portion 105 engage with each other to function as a mechanical fastener, it becomes easier to obtain an appropriate engaging force, enabling stable fixation.

In addition, in the sheet roll 10 according to this embodiment, the unwinding force is 0.984 N/cm (corresponding to 2.5 N/25 mm) or less. If the unwinding force is 0.984 N/cm or less, the hook portion 3 is not overloaded during unwinding, and stable quality can be ensured. In addition, the unwinding force can be 0.787 N/cm (corresponding to 2.0 N/25 mm) or less, 0.591 N/cm (corresponding to 1.5 N/25 mm) or less, or 0.394 N/cm (corresponding to 1.0 N/25 mm) or less. On the other hand, the unwinding force can be 0.039 N/cm (corresponding to 0.1 N/25 mm) or more.

Here, we will explain the method for measuring the unwinding force. The unwinding force was measured in accordance with the measurement of adhesive strength (JIS Z 0237). In detail, first, the hook sheet 1 was adhered to a test plate specified in JIS G 4305, and the adhesive layer 4 of the second layer of hook sheet 1 was adhered so as to overlap the hook portion 3 of this hook sheet 1. Next, using a device equivalent to the tensile test device specified in JIS, the second layer of hook sheet 1 was pulled in a direction perpendicular to the first layer of hook sheet 1, and the unwinding force was measured.

Next, the action and effect of the hook sheet 1 according to this embodiment will be described. As described above, the hook sheet 1 can maintain shape stability because the thickness t1 of the substrate 2 is 35 μm or more, and can maintain the flexibility required for use in sanitary products and the like because it is 70 μm or less. In addition, the area of the head 32 per 1 cm ² of the substrate 2 is 15,000,000 μm ² or more and 23,000,000 μm ² or less, so it is unlikely to be overloaded when peeled off from the adhesive layer 4. As a result, it is easy to ensure stable quality when the hook sheet 1 is unwound from the sheet roll 10.

In the above-mentioned hook sheet 1, the adhesive strength of the adhesive layer 4 may be 4 N/cm or more and 10 N/cm or less. By setting the adhesive strength of the adhesive layer 4 within this range, when the sheet roll 10 is formed, it becomes easier to ensure the desired adhesive strength while maintaining releasability.

The head 32 of the hook portion 3 has an overhang 32a that protrudes from the post portion 31, and the protrusion dimension d of the overhang 32a may be 70 μm or more and 120 μm or less. As a result, it becomes easier to ensure the desired engagement force when functioning as a mechanical fastener.

The overhang 32a may extend in both directions opposite to the column portion 31. By having the overhang 32a extend in both directions, when the hook portion 3 is engaged with another engaging portion 105 as a mechanical fastener, the engagement is not biased on one side only, but is engaged from both sides, reducing unevenness in the engagement state.

In addition, if the thickness of the substrate 2 of the hook sheet 1 is 45 μm or more, this is advantageous in terms of ensuring strength stability when unwound from the sheet roll 10.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[Example 1]
The substrate and hook portion of the hook sheet according to Example 1 are PP (polypropylene), and the adhesive layer is synthetic rubber. The area of the substrate was 100 ^cm2 . The thickness dimension of the substrate was 60 μm. The head of the hook portion according to Example 1 has overhangs that extend in both directions facing each other with the column portion as the center. The extension dimension of one of the overhangs that extend in both directions was 80 μm. The density of the hook portion according to Example 1 was 1600 per square inch.

When the hook sheet of Example 1 is viewed from the hook portion side in a plan view, the head area per square centimeter of the substrate ("Head area" in Table 1), the unwinding force and the engagement force of the hook sheet of Example 1 are as shown in Table 1.

[Example 2]
The substrate and hook portion of the hook sheet according to Example 2 are PP, and the adhesive layer is synthetic rubber. The area of the substrate was 100 ^cm2 . The thickness dimension of the substrate of the hook sheet according to Example 2 was 60 μm. The head of the hook portion according to Example 2 has overhangs that extend in both directions facing each other with the column portion as the center. The extension dimension of one of the overhangs that extend in both directions was 110 μm. The density of the hook portion according to Example 2 was 1600 per square inch.

When the hook sheet of Example 2 is viewed from the hook portion side in a plan view, the head area per square centimeter of the substrate ("Head area" in Table 1), the unwinding force and the engagement force of the hook sheet of Example 2 are as shown in Table 1.

[Example 3]
The hook sheet according to Example 3 is the same as the hook sheet according to Example 2, except for the overhang overhang dimension. The overhang dimension of one of the hook portions according to Example 3 was 95 μm. The density of the hook portion according to Example 3 was 1600 hooks per square inch.

When the hook sheet of Example 3 is viewed from the hook portion side in a plan view, the head area per square centimeter of the substrate ("Head area" in Table 1), the unwinding force and the engagement force of the hook sheet of Example 3 are as shown in Table 1.

[Comparative Example 1]
The substrate and hook portion of the hook sheet according to Comparative Example 1 are PP, and the adhesive layer is synthetic rubber. The area of the substrate was 100 ^cm2 . The thickness dimension of the substrate of the hook sheet according to Comparative Example 1 was 60 μm. The head of the hook portion according to Comparative Example 1 has overhangs that extend in both directions facing each other with the column portion as the center. The extension dimension of one of the overhangs that extend in both directions was 45 μm. The density of the hook portion according to Comparative Example 1 was 1600 per square inch.

When the hook sheet according to Comparative Example 1 is viewed in plan from the hook portion side, the head area per square centimeter of the substrate ("Head area" in Table 1), the unwinding force and the engagement force of the hook sheet according to Comparative Example 1 are as shown in Table 1.

[Comparative Example 2]
The substrate and hook portion of the hook sheet according to Comparative Example 2 are PP, and the adhesive layer is synthetic rubber. The area of the substrate was 100 ^cm2 . The thickness dimension of the substrate of the hook sheet according to Comparative Example 2 was 85 μm. The head of the hook portion according to Comparative Example 2 has overhangs that extend in both directions facing each other with the column portion as the center. The extension dimension of one of the overhangs that extend in both directions was 110 μm. The density of the hook portion according to Comparative Example 1 was 1600 per square inch.

When the hook sheet of Comparative Example 2 is viewed from the hook portion side in a plan view, the head area per square centimeter of the substrate ("Head area" in Table 1), the unwinding force and the engagement force of the hook sheet of Comparative Example 2 are as shown in Table 1.

[Comparative Example 3]
The hook sheet according to Comparative Example 3 is the same as the hook sheet according to Comparative Example 2, except for the overhang overhang dimension. The overhang dimension of one of the hook portions according to Comparative Example 3 was 90 μm. The density of the hook portion according to Comparative Example 3 was 1600 hooks per square inch.

When the hook sheet of Comparative Example 3 is viewed from the hook portion side in a plan view, the head area per square centimeter of the substrate ("Head area" in Table 1), the unwinding force and the engagement force of the hook sheet of Comparative Example 3 are as shown in Table 1.

[Comparative Example 4]
The hook sheet according to Comparative Example 4 is the same as the hook sheet according to Comparative Example 2, except for the overhang overhang dimension. The overhang dimension of one of the hook portions according to Comparative Example 4 was 17.5 μm. The density of the hook portion according to Comparative Example 4 was 1600 hooks per square inch.

When the hook sheet of Comparative Example 4 is viewed from the hook portion side in a plan view, the head area per square centimeter of the substrate ("Head area" in Table 1), the unwinding force and the engagement force of the hook sheet of Comparative Example 4 are as shown in Table 1.

[Comparative Example 5]
The substrate and hook portion of the hook sheet according to Comparative Example 5 are PP, and the adhesive layer is synthetic rubber. The area of the substrate was 100 ^cm2 . The thickness dimension of the substrate of the hook sheet according to Comparative Example 5 was 45 μm. The head of the hook portion according to Comparative Example 5 has overhangs that extend in both directions facing each other with the column portion as the center. The extension dimension of one of the overhangs that extend in both directions was 65 μm. The density of the hook portion according to Comparative Example 5 was 3500 per square inch.

When the hook sheet of Comparative Example 5 is viewed from the hook portion side in a plan view, the head area per square centimeter of the substrate ("Head area" in Table 1), the unwinding force and the engagement force of the hook sheet of Comparative Example 5 are as shown in Table 1.

[Flexibility]
It was confirmed that appropriate flexibility was ensured in Examples 1 to 3 and Comparative Example 1. On the other hand, it was confirmed that Comparative Examples 2 to 4 were too hard and difficult to handle, and Comparative Example 5 was too soft and lacked shape stability.

[Unwinding force]
"A" in Table 1 indicates that the unwinding force was good and no defects occurred in the hook portion. On the other hand, "B" in Table 1 indicates that some defects occurred in the hook portion. Examples 1 to 3 and Comparative Examples 1 and 4 were evaluated as "A." Comparative Examples 2, 3, and 5 were all evaluated as "B."

[Engagement force]
"A" in Table 1 indicates a case where the engaging force was appropriate, and "B" in Table 1 indicates a case where the engaging force was inappropriate. Examples 1 to 3 and Comparative Examples 2 and 3 were evaluated as "A." Comparative Examples 1, 4, and 5 were evaluated as "B."

1... hook sheet, 2... substrate, 3... hook portion, 4... adhesive layer, 10... sheet roll, 31... column portion, 32... head portion, 32a... overhang, t1... substrate thickness, d... overhang projection dimension.

Claims (5)

A substrate;
A plurality of hook portions provided on one surface of the base material;
An adhesive layer provided on the other surface of the base material,
the hook portion includes a column portion standing on the base material and a head portion provided at the tip of the column portion , and the hook sheet is wound into a roll shape such that the adhesive layer faces inwardly and close to the core, and the hook portion faces outwardly and farther from the core ;
The thickness of the substrate is 45 μm or more and 70 μm or less;
When the base material is viewed in plan, the area of the head per 1 ^cm2 of the base material is 15,000,000 ^μm2 or more and 23,000,000 ^μm2 or less;
A hook sheet in which a SUS steel plate that has been cold-rolled and then bright heat-treated as a surface finish is used as a test plate, the test plate has a surface roughness of arithmetic mean roughness of 50±25 μm, the hook sheet is adhered to the test plate, and when pulled in a direction perpendicular to the test plate, the adhesive strength of the adhesive layer is 4 N/cm or more and 10 N/cm or less. The hook sheet according to claim 1, wherein the thickness of the adhesive layer is 5 μm or more and 300 μm or less. The hook sheet according to claim 1 or 2, wherein the head portion has an overhang that protrudes from the column portion, and the protruding dimension of the overhang is 70 μm or more and 120 μm or less. The hook sheet according to claim 3, wherein the overhangs extend in opposite directions relative to the column portion. The hook sheet according to any one of claims 1 to 4 , wherein the substrate comprises a polyolefin.