absorbent articles

Abstract

To provide an absorbent article in which a core wrap sheet containing recycled pulp is unlikely to be broken even after many hours of use.SOLUTION: Absorbent articles (1, 100) include absorbent cores (33a, 33b, 103) and core wrap sheets (38, 39, 108, 109) including recycled pulp recycling disposable absorbent articles. The core wrap sheets are bonded with separate body sheets (34, 35, 104, 105) adjacent to the core wrap sheets (38, 39, 108, 109) in the thickness direction of the absorbent articles (1, 100) to configure composite sheets (C1, C2, C3, C4) so that the core wrap sheets are not broken when the absorbent articles (1, 100) are pulled up after being soaked in 0.9% physiological saline for 30 minutes, are double-folded in the center in a manufacture longitudinal direction, and suspended for 10 minutes or when they are double-folded in the center in the product width direction and suspended for 10 minutes.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an absorbent article. [Background technology]

[0002] In recent years, efforts to achieve the Sustainable Development Goals (SDGs) have been required, and in response to this, efforts to make effective use of resources are being promoted. For example, technologies are known for recovering and recycling pulp fibers, superabsorbent resins (superabsorbent polymers), and the like from used absorbent articles. Among such material recycling methods, there is also a demand for the promotion of horizontal recycling, such as recovering raw material pulp from used disposable diapers and manufacturing disposable diapers again. For example, Patent Document 1 discloses a paper composition and recycled paper containing pulp and absorbent resin recovered from absorbent articles. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-75819 Summary of the Invention [Problem to be solved by the invention]

[0004] The recycled paper described in Patent Document 1 contains a low-molecular-weight absorbent resin, which increases its strength and allows it to be used as absorbent sanitary paper, kraft paper, copy paper, and other products for applications such as disposable diapers and sanitary products. However, when such recycled paper is used as a material for absorbent articles, it is required to have sufficient strength to prevent damage to the material even after prolonged use. In particular, sheet materials made from recycled pulp, which is extracted from used diapers and made reusable, tend to have shortened pulp fiber length due to washing processes during the recycling process and may contain trace amounts of foreign matter. As a result, the bonds between fibers weaken during the process of forming the recycled pulp into a sheet, potentially reducing the material's strength. Furthermore, when sheet materials containing such recycled pulp are used as core wrap sheets covering the absorbent core of absorbent articles, the core wrap sheets may tear if they remain wet with liquids such as bodily fluids or excrement for a long period of time during use of the absorbent article.

[0005] The present invention was made in consideration of the above-mentioned problems, and its purpose is to provide an absorbent article in which the core wrap sheet made from recycled pulp is less likely to break even after long-term use. [Means for solving the problem]

[0006] The main invention to achieve the above object is: an absorbent core; A core wrap sheet containing recycled pulp from disposable absorbent articles. An absorbent article comprising: The core wrap sheet is bonded to a separate sheet adjacent to the core wrap sheet in the thickness direction of the absorbent article to form a composite sheet so that the core wrap sheet does not break when the absorbent article is immersed in 0.9% physiological saline for 30 minutes, taken out, folded in half at the center in the longitudinal direction of the product, and hung for 10 minutes, or folded in half at the center in the width direction of the product, and hung for 10 minutes. It consists of The recycled pulp content in the core wrap sheet is less than 15% by weight, When the direction in which the tensile strength of the core wrap sheet is higher out of the longitudinal direction and the width direction of the absorbent article is defined as the tensile direction, When the composite sheet is pulled in the pulling direction, the tensile force per unit width at which the core wrap sheet in the composite sheet starts to break is higher than the tensile force per unit width at which the separate sheet starts to break when the separate sheet is pulled alone in the pulling direction. The absorbent article is characterized by the above. Other features of the present invention will become apparent from the description of this specification and the accompanying drawings. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an absorbent article in which the core wrap sheet containing recycled pulp is less likely to break even after long-term use. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic plan view of an absorbent pad 1 as an absorbent article according to a first embodiment, in an unfolded and stretched state, as viewed from the skin-facing side. [Figure 2] FIG. 2 is an exploded perspective view of the main part of the absorbent pad 1 shown in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line BB shown in FIG. [Figure 4] 1 is a plan view showing an application area T1 of a hot melt adhesive that joins the topsheet 34 and the first core wrap sheet 38 of the absorbent pad 1. FIG. [Figure 5] FIG. 10 is a plan view showing an application area T2 of a hot melt adhesive that joins the topsheet 34 and the first core wrap sheet 38 of a modified absorbent pad 1'. [Figure 6] FIG. 2 is a plan view showing a second absorbent core 33b and a second core wrap sheet 39 of the absorbent pad 1 in an unfolded state. [Figure 7] FIG. 1 is a schematic plan view of a disposable diaper 100 as an absorbent article according to a second embodiment, in an unfolded and stretched state, as viewed from the skin-facing side. [Figure 8] FIG. 8 is a cross-sectional view taken along the line AA shown in FIG. [Figure 9] 1 is a table showing the evaluation results of the tensile strength of each sheet. [Figure 10]1 shows an example of a load-elongation diagram in a tensile test of composite sheet B. [Figure 11] 10 is a plan view showing the application area of ​​adhesive that bonds the topsheet 104 and the skin-side core wrap sheet 108. FIG. [Figure 12] 10 is a plan view showing the application area of ​​adhesive that bonds the non-skin side core wrap sheet 109 and the back sheet 105. FIG. [Figure 13] 12, which further shows an adhesive that bonds absorbent core 103 and non-skin-side core wrap sheet 109 together. DETAILED DESCRIPTION OF THE INVENTION

[0009] At least the following matters will become clear from the description of this specification and the accompanying drawings. The absorbent article comprises an absorbent core and a core wrap sheet containing recycled pulp from disposable absorbent articles, wherein the core wrap sheet is joined to a separate sheet adjacent to the core wrap sheet in the thickness direction of the absorbent article to form a composite sheet so that the core wrap sheet does not tear when the absorbent article is immersed in 0.9% saline solution for 30 minutes, then removed, folded in half at the center of the longitudinal direction of the product, and hung for 10 minutes, or folded in half at the center of the width direction of the product, and hung for 10 minutes.

[0010] In such an absorbent article, the core wrap sheet in the composite sheet does not tear even under the above-mentioned conditions assuming long-term use. Therefore, by joining the core wrap sheet and the separate sheet, the tear resistance of the core wrap sheet itself in the composite sheet can be improved to such an extent that the absorbent article can be used without tearing even after being immersed for such a long time.

[0011] Such an absorbent article preferably comprises a skin-side composite sheet, which is the composite sheet arranged on the skin side of the absorbent core in the thickness direction, and a non-skin-side composite sheet, which is the composite sheet arranged on the non-skin side of the absorbent core in the thickness direction, and the core wrap sheet in the skin-side composite sheet is preferably a skin-side core wrap sheet arranged adjacent to the skin side of the absorbent core, and the core wrap sheet in the non-skin-side composite sheet is preferably a non-skin-side core wrap sheet arranged adjacent to the non-skin side of the absorbent core.

[0012] In such absorbent articles, the absorbent core swells when it absorbs liquid, and if a core wrap sheet is provided to wrap the absorbent core, the expansion of the core applies force to the core wrap sheet, which may tear the core wrap sheet at the side portions wrapping the core. By arranging the core wrap sheet separately on the skin side and the non-skin side, the load on the core wrap sheet can be reduced, thereby reducing the risk of tearing.

[0013] In such an absorbent article, it is desirable that the absorbent core contains a superabsorbent polymer, and that the mass ratio of the superabsorbent polymer in the absorbent core is 28% or less.

[0014] In such absorbent articles, if the ratio of superabsorbent polymer is high, there is a possibility that the superabsorbent polymer will not be able to remain within the fiber aggregate of the absorbent core when absorbing liquid, causing leakage.However, by setting the mass ratio to 28% or less, the risk of leakage can be reduced and the core wrap sheet can be made less likely to tear.

[0015] It is desirable that such an absorbent article has a first absorbent core containing at least a superabsorbent polymer and a second absorbent core containing at least a superabsorbent polymer, wherein the mass ratio of the superabsorbent polymer contained in the first absorbent core is greater than the mass ratio of the superabsorbent polymer contained in the second absorbent core, and wherein a first core wrap sheet, which is the core wrap sheet, is arranged so as not to wrap around the first absorbent core, and a second core wrap sheet, which is the core wrap sheet, is provided to wrap around the second absorbent core.

[0016] In such an absorbent article, by forming the first core wrap sheet of the first absorbent core, which has a large amount of superabsorbent polymer, in a form that does not wrap around the first absorbent core, the burden on the first core wrap sheet of the first absorbent core, which has a large amount of superabsorbent polymer and is more likely to swell, is reduced, and the risk of the core wrap sheet tearing is reduced.

[0017] In such an absorbent article, it is desirable that the core wrap sheet contains a thermoplastic resin.

[0018] Such an absorbent article can reduce the risk of damage to the core wrap sheet containing the thermoplastic resin.

[0019] In such an absorbent article, it is desirable that the separate sheet contains a thermoplastic resin, and that the core wrap sheet and the separate sheet are heat-sealed.

[0020] In such an absorbent article, the strength of the core wrap sheet in the composite sheet can be increased by heat-sealing the thermoplastic resin of the core wrap sheet and the thermoplastic resin of the separate sheet.

[0021] In such an absorbent article, it is desirable that the thermoplastic resin of the core wrap sheet and the thermoplastic resin of the separate sheet are the same type of thermoplastic resin.

[0022] In such an absorbent article, the strength of the core wrap sheet in the composite sheet can be increased by heat fusion of the same type of thermoplastic resin.

[0023] In the absorbent article, the core wrap sheet contains a thermoplastic resin, and at least a portion of the core wrap sheet has an overlapping region where the core wrap sheets overlap each other in a plan view of the absorbent article in an unfolded state, and the core wrap sheets are heat-sealed to each other in the overlapping region. It is desirable.

[0024] In such an absorbent article, the core wrap sheets are heat-sealed to each other, thereby increasing the strength of the core wrap sheets and further reducing the risk of tearing.

[0025] In such an absorbent article, it is desirable that the recycled pulp content in the core wrap sheet is less than 15% by weight, and that when the composite sheet is pulled in the fiber orientation direction of the core wrap sheet, the tensile force per unit width at which the core wrap sheet in the composite sheet begins to break is higher than the tensile force per unit width at which the separate sheet begins to break when the separate sheet is pulled alone in the fiber orientation direction.

[0026] In this absorbent article, by joining the core wrap sheet, which has a recycled pulp content of less than 15% by weight, to the separate sheet, the core wrap sheet has a strength that is strong enough to withstand a tensile force greater than the tensile force that would cause the separate sheet to begin to break. By improving the strength of the core wrap sheet, the risk of tearing can be reduced.

[0027] In such an absorbent article, it is desirable that the core wrap sheet and the separate sheet in the composite sheet are joined together by a hot melt adhesive.

[0028] In such an absorbent article, by bonding with a hot melt adhesive, it is possible to improve the resistance to tearing when the core wrap sheet in the composite sheet remains in a state where liquid has penetrated into it for a long period of time.

[0029] In such an absorbent article, it is desirable that the hot melt adhesive is applied in a planar manner at least in a part thereof.

[0030] In such an absorbent article, the strength of the core wrap sheet can be further increased in the areas where the hot melt is applied without any gaps (solid application areas).

[0031] In such an absorbent article, it is desirable that the composite sheet has a non-bonded region where the core wrap sheet and the separate sheet are not bonded by the hot melt adhesive.

[0032] With such an absorbent article, if hot melt is applied to the entire surface without any gaps, the composite sheet may become hard, but by having non-bonded areas, softness can be maintained and a balance between strength and hardness can be achieved.

[0033] In such an absorbent article, it is desirable that at least a portion of the bonding area where the core wrap sheet and the separate sheet are bonded by the hot melt adhesive is provided over the entire area in the fiber orientation direction of the core wrap sheet.

[0034] In such an absorbent article, the tensile strength is high in the fiber orientation direction, and the hot melt adhesive bonding area is present throughout the entire fiber orientation direction of such a core wrap sheet, making the core wrap sheet more resistant to tearing.

[0035] In such an absorbent article, it is desirable that the separate sheet in the non-skin side composite sheet is a liquid-impermeable sheet member, and that in the non-skin side composite sheet, the non-skin side core wrap sheet and the separate sheet are joined together with a hot melt adhesive.

[0036] In such an absorbent article, the core wrap sheet in the non-skin side composite sheet is less likely to tear by being joined to a liquid-impermeable sheet member (film, etc.) with a hot melt adhesive, thereby reducing the risk of leakage from the non-skin side.

[0037] In such an absorbent article, the separate sheet of the non-skin side composite sheet is arranged adjacent to the non-skin side of the non-skin side core wrap sheet, the non-skin side composite sheet has a non-bonded area where the non-skin side core wrap sheet and the separate sheet are not bonded with hot melt adhesive, the absorbent core and the non-skin side core wrap sheet have a core bonded area where they are bonded to each other with the hot melt adhesive, and when the absorbent article is viewed in a planar state in an unfolded state, it is desirable that the non-bonded area has a portion that overlaps with the core bonded area.

[0038] In such an absorbent article, the non-bonded area where hot melt adhesive is not applied may have reduced strength, but by having an overlapping portion with the core bonded area where the absorbent core and the non-skin side core wrap sheet are bonded, the reduction in strength can be suppressed.

[0039] In such an absorbent article, the separate sheet of the skin-side composite sheet is a liquid-permeable sheet member, and the separate sheet of the non-skin-side composite sheet is a liquid-impermeable sheet member, and it is desirable that when the non-skin-side composite sheet is pulled in the fiber orientation direction of the core wrap sheet, the tensile force per unit width at which the core wrap sheet in the non-skin-side composite sheet begins to break is higher than the tensile force per unit width at which the core wrap sheet in the skin-side composite sheet begins to break when the skin-side composite sheet is pulled in the fiber orientation direction of the core wrap sheet.

[0040] In such an absorbent article, the tensile force at which the core wrap sheet in the composite sheet begins to break increases as the tensile force at which the separate sheet to which it is joined begins to break increases. Because the non-skin-side composite sheet is joined to a liquid-impermeable sheet member (separate sheet), the core wrap sheet of the non-skin-side composite sheet has a higher tensile force at which it begins to break than the core wrap sheet of the skin-side composite sheet. By positioning the more tear-resistant core wrap sheet on the non-skin-side of the absorbent core, the leakage prevention effect is improved.

[0041] ===First Embodiment=== As an example of the absorbent article according to the first embodiment, an absorbent pad 1 that absorbs excrement such as urine and feces will be described. However, the absorbent article is not limited to the above, and can also be applied as a tape-type disposable diaper for adults or children, a sanitary napkin, etc.

[0042] <Basic structure of absorbent pad 1> Fig. 1 is a schematic plan view of an absorbent pad 1 as an absorbent article according to a first embodiment in an unfolded and stretched state, viewed from the skin side. Fig. 2 is an exploded perspective view of a main part of the absorbent pad 1 shown in Fig. 1. Fig. 3 is a cross-sectional view taken along line BB shown in Fig. 1.

[0043] As shown in Fig. 1, the absorbent pad 1 has a longitudinal direction and a width direction in an unfolded and stretched state. As shown in Fig. 3, the direction in which the components constituting the absorbent pad 1 are layered is called the thickness direction. In the thickness direction, the side in contact with the wearer is called the skin side, and the opposite side is called the non-skin side.

[0044] The "unfolded state" of the absorbent pad 1 refers to the state in which the absorbent pad 1 is unfolded in its longitudinal direction and spread out on a flat surface. The "stretched state" of the absorbent pad 1 refers to the state in which the entire absorbent pad 1 (the entire product) is stretched without wrinkles, specifically, the state in which the dimensions of each component constituting the absorbent pad 1 (for example, the leakage-preventing wall elastic members 60, the absorbent core 3, etc., which will be described later) are stretched until they match or are close to the dimensions of the component alone (i.e., the dimensions when the elastic properties of the elastic members are not expressed).

[0045] As shown in Figures 1 and 2, the absorbent pad 1 comprises a top sheet 34, a back sheet 35, an absorbent body 33, an exterior sheet 36, and a pair of side sheets 37. The top sheet 34 is a liquid-permeable sheet provided closer to the skin than the absorbent body 33 in the thickness direction, and examples of such a sheet include an air-through nonwoven fabric and a spunbond nonwoven fabric. The back sheet 35 is a liquid-impermeable sheet provided closer to the skin than the absorbent body 33 in the thickness direction, and examples of such a sheet include a synthetic resin film and a hydrophobic SMS nonwoven fabric. The top sheet 34 and the back sheet 35 contain a thermoplastic resin (such as polyethylene (PE) or polypropylene (PP)).

[0046] The pair of side sheets 37 are sheets (e.g., nonwoven fabric) that extend outward in the width direction from both widthwise edges on the skin-facing side of the top sheet 34. The exterior sheet 36 is a liquid-impermeable sheet that is located closer to the skin than the back sheet 5 in the thickness direction, and forms the outer shape of the absorbent pad 1, i.e., a shape in which the longitudinal center is narrowed inward in the width direction.

[0047] The absorbent body 33 is a member having liquid absorption and liquid retention properties and is located between the topsheet 34 and the backsheet 35 in the thickness direction. In the first embodiment, the absorbent body 33 includes a first absorbent core 33a located on the skin side and a second absorbent core 33b located on the non-skin side of the first absorbent core 33a. The first absorbent core 33a and the second absorbent core 33b can be, for example, liquid-absorbent fibers such as pulp containing SAP (super absorbent polymer) molded into a predetermined shape. In this embodiment, the first absorbent core 33a has a generally gourd- or hourglass-like shape that is long in the longitudinal direction and has a narrowed portion near the center in the longitudinal direction that extends inward in the width direction. On the other hand, the second absorbent core 33b has a generally rectangular shape that is long in the longitudinal direction and narrow in the width direction in a plan view. The second absorbent core 33b has a longitudinal dimension shorter than that of the first absorbent core 33a and a width dimension shorter than that of the first absorbent core 33a. Therefore, both longitudinal and widthwise end edges of the first absorbent core 33a are located outside both longitudinal and widthwise end edges of the second absorbent core 33b. There are no particular restrictions on the shape of the absorber 33.

[0048] In the first embodiment, a first core wrap sheet 38 is provided on the skin side of the first absorbent core 33a, and a second core wrap sheet 39 is provided to wrap the second absorbent core 33b from the non-skin side. In the first embodiment, the first core wrap sheet 38 is arranged so as not to wrap the first absorbent core 33a. The first and second core wrap sheets 38, 39 are made of, for example, tissue or the like, as will be described in detail later. The first and second core wrap sheets 38, 39 contain a thermoplastic resin in addition to pulp fiber as a liquid-absorbent fiber. Examples of thermoplastic resins include polyethylene (PE) and polypropylene (PP).

[0049] The absorbent pad 1 also has leakage preventing walls 48. The leakage preventing walls 48 are configured to be able to stand up on the skin-facing side of the wearer, and are provided in a pair on the left and right. As shown in Fig. 3, the leakage preventing walls 48 are formed by folding the inner side portions of the side sheets 37 in the width direction toward the side away from the skin, and providing the folded-back portions with leakage preventing wall elastic members 60 that stretch in the longitudinal direction. The leakage preventing walls 48 can suppress lateral leakage of excrement. Note that, in Fig. 1, thread-like leakage preventing wall elastic members 60 are arranged on each side at intervals in the width direction, but the number of these is not particularly limited.

[0050] In this embodiment, the first absorbent core 33a of the absorbent body 33 has a slit 45a recessed in the thickness direction from the skin side to the non-skin side, preferably a through slit 45a. The slit 45a is located closer to the ventral side than the longitudinal center of the absorbent pad 1 and extends longitudinally through the center of the width of the absorbent body 33. The second absorbent core 33b has a slit 45b recessed in the thickness direction from the skin side to the non-skin side, preferably a through slit 45b. The slit 45b is located closer to the ventral side than the longitudinal center of the absorbent pad 1 and extends longitudinally through the center of the width of the absorbent body 33. The slits 45a and 45b are formed to at least partially overlap in a plan view. This allows excreted urine that reaches the second absorbent core 33b through the slit 45a of the first absorbent core 33a to be drawn further into the second absorbent core 33b via the slit 45b. The longitudinal dimensions (length) and width dimensions (width) of the slits 45a, 45b in a plan view are appropriately adjusted in consideration of the sizes of the first absorbent core 33a and the second absorbent core 33b. The width and length of the slits 45a, 45b are, for example, 5.0 to 50 mm and 50 to 300 mm.

[0051] In this embodiment, the absorbent body 33 includes a pair of compressed portions 46. The pair of compressed portions 46 extend longitudinally on both widthwise outer sides of the slit 45a. The pair of compressed portions 46 are formed by compressing the first absorbent core 33a and the second absorbent core 33b in the thickness direction, starting from the skin-facing surface of the first absorbent core 33a. However, the pair of compressed portions 46 may also be formed by compressing both the topsheet 34 and the absorbent body 33. Each of the pair of compressed portions 46 is formed linearly in a plan view, but their shape is not particularly limited. The pair of compressed portions 46 prevents urine from moving outward on the topsheet 34 and leaking to the outside, and makes it easier to draw urine into the absorbent body 33.

[0052] <First core wrap sheet 38 and second core wrap sheet 39> In this embodiment, the first core wrap sheet 38 and the second core wrap sheet 39 contain recycled pulp recycled from used disposable absorbent articles (e.g., used disposable diapers). Generally, absorbent articles require strong materials to prevent the absorbent core from being exposed to the outside after prolonged use. Meanwhile, sheet materials containing recycled pulp, which is made reusable by extracting raw pulp from collected used disposable absorbent articles and recycling the pulp, are characterized by the fact that the fiber length of the recycled pulp shortens during processes such as washing. This reduces the strength of the material. For example, when a sheet containing recycled pulp is used as a core wrap sheet, there is a risk that the core wrap sheet may tear if liquids such as bodily fluids or excrement remain in the core wrap sheet for a long period of time during use of the absorbent article.

[0053] In this regard, in the absorbent pad 1, the first core wrap sheet 38 (second core wrap sheet 39) is joined to a separate sheet adjacent to the first core wrap sheet 38 (second core wrap sheet 39) in the thickness direction of the absorbent pad 1 to form a composite sheet. Specifically, the separate sheet opposite the first core wrap sheet 38 is the top sheet 34, and the first core wrap sheet 38 and the top sheet 34 are joined to form a first composite sheet C1. As shown in FIG. 3, the first composite sheet C1 is disposed on the skin side of the first absorbent core 33a in the thickness direction. Furthermore, the separate sheet opposite the second core wrap sheet 39 is the back sheet 35, and the non-skin side of the second core wrap sheet 39 is joined to the back sheet 35 to form a second composite sheet C2. As shown in FIG. 3, the second composite sheet C2 is disposed on the non-skin side of the second absorbent core 33b in the thickness direction.

[0054] Here, the following test was conducted to confirm whether the first core wrap sheet 38 containing recycled pulp would break even when the absorbent pad 1 was used for a long period of time. Fig. 4 is a plan view showing the application area T1 of the hot melt adhesive that joins the top sheet 34 of the absorbent pad 1 to the first core wrap sheet 38, and Fig. 5 is a plan view showing the application area T2 of the hot melt adhesive that joins the top sheet 34 of the absorbent pad 1' to the first core wrap sheet 38 as a modified example. The absorbent pad 1 and the absorbent pad 1' each have a center line CL that passes through the center in the width direction and extends in the longitudinal direction, and a center line CW that passes through the center in the longitudinal direction and extends in the width direction.

[0055] (sample) First, as a test sample, The absorbent pad 1 of this embodiment (a sample in which the top sheet 34 and the first core wrap sheet 38 are joined in the application area T1 shown in FIG. 4) Absorbent pad 1', a modified example of absorbent pad 1 (a sample in which the top sheet 34 and the first core wrap sheet 38 are joined in the application region T2 (only the central portion) shown in FIG. 5) In both (1) and (2), the recycled pulp content of the first core wrap sheet 38 included in the absorbent pad 1 (1') was 7.5% by weight, and the length of the first core wrap sheet 38 in the longitudinal direction was 550 mm and the length in the width direction was 153 mm. (Test Method) <Test 1> 1. Immerse the sample in 10 L of 0.9% saline for 30 minutes. 2. Pull up the sample, fold it in half at the center of the product's longitudinal direction, and hang the sample with a 10 mm diameter rod aligned along the center line (center line CW in Figures 4 and 5) that passes through the center of the sample's longitudinal direction, and leave it for 10 minutes. <Test 2> 1. Immerse the sample in 10 L of 0.9% saline for 30 minutes. 2. Pull up the sample, fold it in half at the center of the product's width, and hang the sample with a 10 mm diameter rod aligned along the center line (center line CL in Figures 4 and 5) that passes through the center of the sample's width, and leave it for 10 minutes. (result) In Test 1, the first core wrap sheet 38 did not break in both Samples (1) and (2). However, in Test 2, the first core wrap sheet 38 of Sample (1) did not break, but the first core wrap sheet 38 of Sample (2) did break.

[0056] The above tests showed that when the first core wrap sheet 38 is bonded to the topsheet 34 (separate sheet) adjacent to the first core wrap sheet 38 in the thickness direction of the absorbent pad 1, as in the absorbent pad 1 of this embodiment, to form a first composite sheet C1, and the absorbent pad 1 is thoroughly immersed in saline, folded in half at the center of the lengthwise direction of the product, and hung for 10 minutes, or folded in half at the center of the widthwise direction of the product, and hung for 10 minutes, the first core wrap sheet 38 does not tear. Therefore, by bonding the first core wrap sheet 38 to the topsheet 34 as in this embodiment, the tear resistance of the first core wrap sheet 38 itself in the first composite sheet C1 can be improved to such an extent that it can be used without tearing even under the above-mentioned conditions. Note that in the above tests, the tear resistance of the first core wrap sheet 38 in the first composite sheet C1 was improved by varying the application area of ​​the hot melt adhesive bonding the topsheet 34 and the first core wrap sheet 38, but this is not limited to this. For example, the tear resistance of the first and second core wrap sheets 38, 39 in each composite sheet (C1, C2) can be improved by increasing the amount of hot melt adhesive per unit area, by increasing the strength of the separate sheets in the first and second composite sheets C1, C2, by changing the amount of superabsorbent polymer in the first absorbent core 33a and the second absorbent core 33b, or by a combination of these.

[0057] Furthermore, the mass ratio of the superabsorbent polymer in the first absorbent core 33a is preferably 28% or less. Here, the mass ratio of the superabsorbent polymer in each absorbent core refers to the ratio of the mass of the superabsorbent polymer to the total mass of each absorbent core (i.e., the mass of the fiber aggregate + the mass of the superabsorbent polymer). If the ratio of the superabsorbent polymer is high, when liquid is absorbed, the superabsorbent polymer may not be retained within the fiber aggregate of the first absorbent core 33a, which may result in leakage. However, by setting the mass ratio of the superabsorbent polymer in the first absorbent core 33a to 28% or less, the risk of leakage can be reduced and the first core wrap sheet 38 of the first absorbent core 33a can be made more resistant to tearing. Furthermore, the following measures have been taken regarding the mass ratio of the superabsorbent polymer in each absorbent core.

[0058] In this embodiment, the mass ratio of the superabsorbent polymer contained in the first absorbent core 33a is greater than the mass ratio of the superabsorbent polymer contained in the second absorbent core 33b. This means that the first absorbent core 33a expands more readily than the second absorbent core 33b when absorbing excrement. The first core wrap sheet 38 of the first absorbent core 33a is configured so as not to encase the first absorbent core 33a, while the second core wrap sheet 39 of the second absorbent core 33b is configured so as to encase the second absorbent core 33b. By configuring the first core wrap sheet 38 of the first absorbent core 33a, which has a higher amount of superabsorbent polymer (SAP), so as not to encase the first absorbent core 33a, the load on the first core wrap sheet 38 of the first absorbent core 33a, which has a higher amount of superabsorbent polymer and therefore expands more readily, is reduced, thereby reducing the risk of the first core wrap sheet 38 tearing.

[0059] In this embodiment, the first absorbent core 33a is positioned on the skin side and the second absorbent core 33b is positioned on the non-skin side of the first absorbent core 33a, but this is not limiting, and the first absorbent core 33a may be positioned on the non-skin side and the second absorbent core 33b on the skin side of the first absorbent core 33a. In other words, the absorbent pad 1 may be configured so that an absorbent core with a high mass ratio of superabsorbent polymer is provided on the non-skin side.

[0060] Furthermore, as described above, if the surface sheet 34 (separate sheet) and the first core wrap sheet 38 contain a thermoplastic resin, for example, by forming compressed portions such as the pair of compressed portions 46 described above on the skin side of the surface sheet 34, the thermoplastic resin of the surface sheet 34 and the thermoplastic resin of the first core wrap sheet 38 are thermally fused together, making it possible to more firmly bond the surface sheet 34 and the first core wrap sheet 38. Therefore, the strength of the first core wrap sheet 38 in the first composite sheet C1 can be increased.

[0061] When the surface sheet 34 (separate sheet) and the first core wrap sheet 38 are heat-sealed, it is desirable that the thermoplastic resin of the first core wrap sheet 38 and the thermoplastic resin of the separate sheet are the same type of thermoplastic resin. Heat-sealing the same type of thermoplastic resin can increase the strength of the first core wrap sheet 38 in the first composite sheet C1.

[0062] Figure 6 is a plan view showing the second absorbent core 33b and second core wrap sheet 39 of the absorbent pad 1 in an unfolded state. For convenience, only the second absorbent core 33b and second core wrap sheet 39 are shown to illustrate the overlap of the second core wrap sheet 39. As shown in Figure 6, at least a portion of the second core wrap sheet 39 has an overlapping region VP where the second core wrap sheets 39 overlap each other in a plan view, and the second core wrap sheets 39 are heat-fused together in the overlapping region VP. Since the second core wrap sheet 39 contains a thermoplastic resin, the second core wrap sheets 39 are heat-fused together, which increases the strength of the second core wrap sheet 39 and further reduces the risk of tearing.

[0063] === Second Embodiment === <Basic structure of 100 diapers> The following description will be given taking as an example a tape-type disposable diaper for adults (hereinafter also referred to as diaper 100) as an example of an absorbent article according to the second embodiment.

[0064] Fig. 7 is a schematic plan view of a disposable diaper 100 as an absorbent article according to a second embodiment in an unfolded and stretched state, as seen from the skin side. Fig. 8 is a cross-sectional view taken along line AA shown in Fig. 7.

[0065] As in the first embodiment, the diaper 100 has a longitudinal direction, a width direction, and a thickness direction in the unfolded and stretched state (FIG. 7). The diaper 100 is divided into three regions in the longitudinal direction: a ventral waistband 101A that contacts the wearer's ventral side; a dorsal waistband 101C that contacts the wearer's dorsal side; and a crotch section 101B that is located between the ventral waistband 101A and the dorsal waistband 101C in the longitudinal direction. As shown in FIG. 8, the thickness direction is the direction in which the components constituting the diaper 100 are layered. In the thickness direction, the side that contacts the wearer is referred to as the skin side, and the opposite side is referred to as the non-skin side. The unfolded and stretched states of the diaper 100 are defined in the same manner as in the first embodiment.

[0066] As shown in FIG. 8, the diaper 100 comprises an absorbent core 103, a top sheet 104 provided on the skin side of the absorbent core 103 in the thickness direction, a back sheet 105 and an outer sheet 106 provided on the non-skin side of the absorbent core 103 in the thickness direction, and a pair of side sheets 107.

[0067] The top sheet 104 may be any liquid-permeable sheet, such as an air-through nonwoven fabric or a spunbond nonwoven fabric. The back sheet 105 may be any liquid-impermeable sheet, such as a synthetic resin film or a hydrophobic SMS nonwoven fabric. The top sheet 104 and the back sheet 105 contain a thermoplastic resin (polyethylene (PE), polypropylene (PP), or the like).

[0068] The pair of side sheets 107 are sheets (e.g., nonwoven fabrics) extending outward in the width direction from both widthwise edges on the skin-facing side of the top sheet 104. The exterior sheet 106 is a liquid-impermeable sheet located closer to the skin than the back sheet 105 in the thickness direction, and forms the outer shape of the diaper 100, i.e., a shape in which the longitudinal center (crotch portion 101B) is narrowed inward in the width direction.

[0069] The absorbent core 103 can be, for example, a liquid-absorbent fiber such as pulp containing SAP (super absorbent polymer) molded into a predetermined shape. In this embodiment, a liquid-permeable skin-side core wrap sheet 108 is disposed adjacent to the skin side of the absorbent core 103, and a liquid-permeable non-skin-side core wrap sheet 109 is disposed adjacent to the non-skin side of the absorbent core 103. The skin-side and non-skin-side core wrap sheets 108, 109 contain a thermoplastic resin in addition to pulp fibers as liquid-absorbent fibers. Examples of thermoplastic resins include polyethylene (PE) and polypropylene (PP). Details of the skin-side and non-skin-side core wrap sheets 108, 109 will be described later.

[0070] As shown in FIG. 7, the diaper 100 also includes flap portions 110 extending outward in the width direction from the back-side waistband portion 101C. The flap portions 110 include a base sheet 111 and a first fastening member 112 and a second fastening member 113 bonded to the base sheet 111. The base sheet 111 is bonded between the side sheet 107 and the outer sheet 106. The first fastening member 112 and the second fastening member 113 are spaced apart in the longitudinal direction and configured to be fastened to target portions 114 provided on the ventral waistband portion 101A when the diaper 100 is worn. Examples of the first fastening member 112 and the second fastening member 113 include hook members. Note that one fastening member may be provided on each side. The diaper 100 may not include the base sheet 111 of the flap portion 110, and the side sheets 107 and the exterior sheet 106 may extend outward in the width direction, and fastening members may be bonded onto the side sheets 107.

[0071] The diaper 100 has longitudinally stretchable leg elastic members 116 on both widthwise sides (see FIG. 8). Three leg elastic members 116 are provided on each side, spaced apart in the widthwise direction. More specifically, the innermost leg elastic member 116 in the widthwise direction is disposed between the topsheet 104 and the backsheet 105. The remaining two leg elastic members 116 are disposed between the sidesheet 107 and the backsheet 105. The number of leg elastic members 116 is not particularly limited.

[0072] The diaper 100 also has inner leakage preventing gathers 117 and outer leakage preventing gathers 118. The inner leakage preventing gathers 117 and the outer leakage preventing gathers 118 are configured to be able to stand up on the wearer's skin side, and are provided in pairs on the left and right. The inner leakage preventing gathers 117 are so-called inward-leaking gathers, and the outer leakage preventing gathers 118 are so-called outward-leaking gathers. The inner leakage preventing gathers 117 are provided widthwise more inward than the outer leakage preventing gathers 118 and the leg-hole elastic members 116. It is sufficient that at least a portion of the inner leakage preventing gathers 117 is located widthwise more inward than the outer leakage preventing gathers 118. The diaper 100 is only required to have at least the outer leakage preventing gathers 118, and is not required to have the inner leakage preventing gathers 117.

[0073] The inner leakage preventing gathers 117 are formed by folding the topsheet 104, as shown in Fig. 8. Specifically, the inner leakage preventing gathers 117 are formed by folding the topsheet 104 from the outside in the width direction to the inside and toward the skin at folding line f1 shown in Fig. 8, and folding the topsheet 104 from the inside in the width direction to the outside and away from the skin at folding line f2, and providing an inner leakage preventing elastic member 171 that stretches in the longitudinal direction at the folded-back portion. An example of the inner leakage preventing elastic member 171 is rubber thread.

[0074] As shown in Fig. 8, the outer leakage preventing gathers 118 are formed by folding the side sheet 107. Specifically, the outer leakage preventing gathers 118 are formed by folding the side sheet 107 from the inside to the outside in the width direction and toward the skin along folding line f3 shown in Fig. 8, and folding the side sheet 107 from the outside to the inside in the width direction and toward the skin along folding line f4, and providing an outer leakage preventing elastic member 181 that stretches in the longitudinal direction at the folded-back portion. An example of the outer leakage preventing elastic member 181 is rubber thread. The inner leakage preventing gathers 117 and the outer leakage preventing gathers 118 can prevent side leakage of body exudates.

[0075] Waist gathers 122 formed by a plurality of waist elastic members 121 are arranged at the longitudinal ends and widthwise center of the back waist portion 101C of the diaper 100. The waist gathers 122 allow the diaper 100 to conform to the shape of the wearer's waist when worn, and also prevent the diaper 100 from shifting out of position.

[0076] (Core wrap sheet, separate sheet and composite sheet in the second embodiment) As in the first embodiment, the skin-side core wrap sheet 108 and the non-skin-side core wrap sheet 109 in the second embodiment contain recycled pulp made from recycled used disposable absorbent articles (e.g., used disposable diapers and absorbent pads). The diaper 100 includes a composite sheet formed by joining the skin-side core wrap sheet 108 to a separate sheet adjacent to the skin-side core wrap sheet 108 in the thickness direction of the diaper 100. In this embodiment, the separate sheet opposite the skin-side core wrap sheet 108 is the top sheet 104, and the skin-side core wrap sheet 108 and the top sheet 104 are joined to form a composite sheet, the skin-side composite sheet C3. The skin-side composite sheet C3 is disposed on the skin side of the absorbent core 103 in the thickness direction. The diaper 100 also includes a composite sheet formed by joining the non-skin-side core wrap sheet 109 to a separate sheet adjacent to the non-skin-side wrap sheet 109 in the thickness direction of the diaper 100. The separate sheet from the non-skin side core wrap sheet 109 is the back sheet 105, and the non-skin side core wrap sheet 109 and the back sheet 105 are joined together to form a composite sheet, the non-skin side composite sheet C4. The non-skin side composite sheet C4 is disposed on the non-skin side of the absorbent core 103 in the thickness direction.

[0077] The effects exerted by the first composite sheet C1 in the first embodiment described above are also the same for the skin side composite sheet C3 in the second embodiment, and the effects exerted by the second composite sheet C2 in the first embodiment are also the same for the non-skin side composite sheet C4 in the second embodiment. Further common functions and effects will be described below.

[0078] In this embodiment, too, the strength of the material is required to prevent damage to the skin side core wrap sheet 108 and non-skin side core wrap sheet 109 containing recycled pulp during use of the diaper 100. Therefore, in order to confirm the material strength of the skin side core wrap sheet 108 in the skin side composite sheet C3 in which the skin side core wrap sheet 108 and the top sheet 104 (separate sheet) are joined, a test was conducted using the following method.

[0079] (Evaluation method) The materials used for evaluation include: a) Recycled tissue as the skin side core wrap sheet 108 containing 15% by weight of recycled pulp b) An example of the surface sheet 104 (separate sheet) is polypropylene spunbond nonwoven fabric (PPSB). c) An example of the surface sheet 104 (separate sheet) is an air-through nonwoven fabric. d) As an example of the skin-side composite sheet C3, a composite sheet A (adhesive application amount 4 g / m) was prepared by bonding the above-mentioned a) and b) with a hot melt adhesive. 2 Apply in a spiral pattern e) As an example of the skin-side composite sheet C3, composite sheet B (adhesive application amount: 4 g / m) was prepared by bonding the above-mentioned a) and c) with a hot melt adhesive. 2 Apply in a spiral pattern We have prepared the following. Each of the sheets a) to e) above was cut into a size of 25 mm x 100 mm to prepare a sample. To measure the strength of each sheet in the fiber orientation direction, the length of the sheet in the fiber orientation direction was set to 100 mm. For example, when the material is a nonwoven fabric, the constituent fibers are aligned in the direction (MD) in which the nonwoven fabric web is conveyed during production, so the fiber orientation direction refers to the direction along which the constituent fibers of such a material run. The tensile strength of a material (sheet) in the orientation direction of the constituent fibers (MD direction of the web) is inherently higher than in the direction perpendicular to the orientation direction of the constituent fibers (CD direction of the web). In other words, the fiber orientation direction refers to the direction in which the strength of the material is higher, either the longitudinal direction or the width direction of the diaper 100. In this embodiment, in the unfolded state shown in FIG. 7 , the fiber orientation direction is the longitudinal direction of the diaper 100, and the direction perpendicular to the orientation direction of the constituent fibers is the width direction.

[0080] The samples were then measured for tensile strength using a tensile testing machine (Shimadzu Corporation, Autograph Model AGS-1KNG, etc.) by pulling the samples in the fiber orientation direction at a speed of 100 mm / min. Similar measurements were performed five times for each sample to calculate the maximum tensile force. The average was used as the maximum tensile force (tensile strength) for each material (a) to (e). Figure 9 shows the evaluation results for the tensile strength of each sheet. Note that the standard width of each sheet was 25 mm, so the denominator for the maximum tensile force is 25 mm. Figure 10 also shows an example of a load-elongation diagram from the tensile test of the composite sheet B described above. The diagram in Figure 10 shows the results of a sample close to the average maximum tensile force among five measurements of the composite sheet B sample. Note that the peak (maximum point) shown in the diagram in Figure 10 is the maximum tensile force, and this peak is the point at which the sheet begins to break; in reality, breakage is complete after the maximum tensile force is reached.

[0081] 9, the maximum tensile strength of a) recycled tissue alone was 9.2 N / 25 mm, while the maximum tensile strength of d) composite sheet A, which is made by bonding recycled tissue and PPSB, was 27.9 N / 25 mm, and the maximum tensile strength of e) composite sheet B, which is made by bonding recycled tissue and air-through nonwoven fabric, was 25.5 N / 25 mm, showing increased strength.The maximum tensile strength of composite sheet A is also higher than the maximum tensile strength of b) PPSB alone, which is a separate sheet (24.1 N / 25 mm), and the maximum tensile strength of composite sheet B is higher than the maximum tensile strength of c) air-through nonwoven fabric alone, which is a separate sheet (18.4 N / 25 mm).

[0082] Here, the maximum tensile force per unit width (25 mm) of each sheet is the tensile force per unit width at which each sheet begins to break, i.e., it is also the tensile force per unit width at which the recycled tissue begins to break in each of composite sheets A and B. Therefore, from the above test, it can be said that when skin-side composite sheet C3 is pulled in the fiber orientation direction of skin-side core wrap sheet 108, the tensile force per unit width at which the skin-side core wrap sheet 108 in skin-side composite sheet C3 begins to break is higher than the tensile force per unit width at which the separate sheet (topsheet 104) begins to break when pulled in the fiber orientation direction. In other words, by joining skin-side core wrap sheet 108 and topsheet 104, the strength of skin-side core wrap sheet 8 becomes such that it will not break unless a force greater than the tensile force at which the topsheet 104 begins to break by itself is applied. By using a skin side core wrap sheet 108 having such strength in the diaper 100, the risk of damage to the skin side core wrap sheet 108 can be reduced even when used by a wearer for a long period of time.

[0083] The above results are the effect of using a skin-side core wrap sheet 108 with a recycled pulp content of 15% by weight. More preferably, the skin-side core wrap sheet 108 has a recycled pulp content of less than 15% by weight. By setting the content to less than 15% by weight, the skin-side core wrap sheet 108 can maintain the above-mentioned strength. By using such a skin-side core wrap sheet 108 in the diaper 100, the risk of the skin-side core wrap sheet 108 being damaged even after long-term use can be reduced.

[0084] The following can also be said about the strength of the non-skin-side core wrap sheet 109 in the non-skin-side composite sheet C4. In this embodiment, as described above, the separate sheet (top sheet 104) of the non-skin-side composite sheet C3 is a liquid-permeable sheet member, and the separate sheet (back sheet 105) of the non-skin-side composite sheet C4 is a liquid-impermeable sheet member. Therefore, when the non-skin-side composite sheet C4 is pulled in the fiber orientation direction of the non-skin-side core wrap sheet 109, the tensile force per unit width at which the non-skin-side core wrap sheet 109 in the non-skin-side composite sheet C4 starts to break is higher than the tensile force per unit width at which the skin-side core wrap sheet 108 in the skin-side composite sheet C3 starts to break when the skin-side composite sheet C3 is pulled in the fiber orientation direction of the skin-side core wrap sheet 108. In other words, the tensile force at the start of tearing of the skin-side and non-skin-side core wrap sheets 108, 109 in each composite sheet increases as the tensile force at the start of tearing of the joined separate sheet increases. Because non-skin-side composite sheet C4 is joined to a liquid-impermeable separate sheet (back sheet 105) such as a synthetic resin film, the non-skin-side core wrap sheet 9 of non-skin-side composite sheet C4 has a higher tensile force at the start of tearing than the skin-side core wrap sheet 8 of skin-side composite sheet C3. In other words, the non-skin-side core wrap sheet 9 of non-skin-side composite sheet C4 is more resistant to tearing than the skin-side core wrap sheet 8 of skin-side composite sheet C3. Therefore, compared to when the tensile force per unit width when the non-skin side core wrap sheet 109 in the non-skin side composite sheet C4 begins to break is lower than the tensile force per unit width when the skin side core wrap sheet 108 in the skin side composite sheet C3 begins to break, the leakage prevention effect can be further improved when the tensile force per unit width when the non-skin side core wrap sheet 109 in the non-skin side composite sheet C4 begins to break is higher than the tensile force per unit width when the skin side core wrap sheet 108 in the skin side composite sheet C3 begins to break.

[0085] In this embodiment, the skin-side core wrap sheet 108 and the top sheet 104 are joined to form the skin-side composite sheet C3, but as a modified example of the diaper 100, it is also possible to place another sheet material, such as an auxiliary sheet, between the skin-side core wrap sheet 108 and the top sheet 104. However, since the composite sheet in this embodiment is formed by joining the skin-side core wrap sheet 8 to a separate sheet that can prevent the contents of the absorbent core 103 from leaking out due to damage to the skin-side core wrap sheet 8, it is preferable that the separate sheet is the top sheet 104 rather than an auxiliary sheet or the like.

[0086] Figure 11 is a plan view showing the adhesive application area that bonds the topsheet 104 and the skin-side core wrap sheet 108. In Figure 11, the topsheet 104 and the skin-side core wrap sheet 108 are seen through to show the adhesive application area 120 (the area with downward-slanting left lines in the center of the width direction). As shown in the figure, in the skin-side composite sheet C3 composed of the topsheet 104 and the skin-side core wrap sheet 108, the skin-side core wrap sheet 108 and the topsheet 104 are bonded together with a planarly applied hot melt adhesive. Bonding with a hot melt adhesive can improve tear resistance when the skin-side core wrap sheet 108 of the skin-side composite sheet C3 is continuously infiltrated with liquids such as excretory fluids.

[0087] Furthermore, as shown in Figure 11, by applying the hot melt adhesive in a planar manner in the application area 120, i.e., by applying the hot melt adhesive without any gaps, the strength of the skin side core wrap sheet 108 can be further increased.

[0088] Fig. 12 is a plan view showing the application area of ​​the adhesive that bonds the non-skinside core wrap sheet 109 and the backsheet 105. Fig. 13 is a plan view of Fig. 12, further showing the adhesive that bonds the absorbent core 103 and the non-skinside core wrap sheet 109. Both Figs. 12 and 13 show the diaper 100 in an unfolded state in plan view, and for ease of explanation, the components are limited. Fig. 12 shows the application area of ​​the adhesive through the non-skinside core wrap sheet 109 and the backsheet 105. Fig. 13 also shows the application area of ​​the adhesive through the non-skinside core wrap sheet 109, backsheet 105, and absorbent core 103.

[0089] In this embodiment, as shown in FIG. 12 , in a non-skin side composite sheet C4 composed of a non-skin side core wrap sheet 109 and a back sheet 105, the non-skin side core wrap sheet 109 and the back sheet 105 are bonded together with a hot melt adhesive. Specifically, the non-skin side composite sheet C4 has multiple bonded regions 125 where the non-skin side core wrap sheet 109 and the back sheet 105 are bonded together with the hot melt adhesive. In this embodiment, there are seven bonded regions 125 spaced apart in the width direction and arranged along the longitudinal direction, but the number is not limited to this. Examples of hot melt adhesive application patterns include, but are not limited to, an Ω pattern, a spiral pattern, and a solid pattern in which the adhesive is applied to the application target area without any gaps. Note that when the bonded region 125 is formed by applying the hot melt adhesive in a circular application pattern, the width of the bonded region 125 (n1, n2, etc., described below) refers to the diameter of the circle, not the width of the line that describes the circle. Furthermore, since the back sheet 105 is a liquid-impermeable sheet material (such as a synthetic resin film), by bonding it with a hot melt adhesive in this manner, the non-skin side core wrap sheet 109 in the non-skin side composite sheet C4 becomes less likely to tear, thereby reducing the risk of leakage from the non-skin side of the diaper 100.

[0090] As shown in Figure 12, the non-skin side composite sheet C4 has a non-bonded region 126 where the non-skin side core wrap sheet 109 and the back sheet 105 are not bonded with hot melt adhesive. Similarly, in the skin side composite sheet C3, the region of the skin side core wrap sheet 108 shown in Figure 11, excluding the application region 120, is the non-bonded region. If the hot melt adhesive were applied to the entire overlapping area between the non-skin side core wrap sheet 109 and the back sheet 105 without any gaps, the non-skin side composite sheet C4 might become stiff. However, by having the non-bonded region 126, softness can be maintained, achieving a balance between strength and stiffness.

[0091] 12 , let n1, n2, . . . n7 be the widthwise lengths of the bonded regions 125 and S1, S2, . . . S8 be the widthwise lengths of the non-bonded regions 126. In this embodiment, the sum of the widthwise lengths of the bonded regions 125 of the non-skin side composite sheet C4 (n1 + n2 + n3 + n4 + n5 + n6 + n7) is longer than the sum of the widthwise lengths of the non-bonded regions 126 (S1 + S2 + S3 + S4 + S5 + S6 + S7 + S8). In other words, the non-skin side composite sheet C4 has more regions that are fixed with hot melt adhesive. This increase in the number of bonded regions 125 improves the strength of the non-skin side composite sheet C4, making the non-skin side core wrap sheet 109 of the non-skin side composite sheet C4 more tear-resistant.

[0092] Furthermore, the length L1 over which the hot melt adhesive is continuously applied in the longitudinal direction of the non-skin side composite sheet C4 (i.e., the longitudinal length of the bonding region 125) is longer than the length over which the hot melt adhesive is continuously applied in the width direction (any of n1 to n7). The non-skin side core wrap sheet 109 has a higher tensile strength in the longitudinal direction, which is the fiber orientation direction, than in the width direction, and by having a long continuous layer of hot melt adhesive in the longitudinal direction, which is the fiber orientation direction, the non-skin side core wrap sheet 109 can be made more resistant to tearing.

[0093] 11, the bonding region (application region 120) where the skin-side core wrap sheet 108 and the top sheet 104 are bonded with the hot melt adhesive is provided over the entire longitudinal area of ​​the skin-side core wrap sheet 108. Similarly, as shown in FIG. 12, the bonding region 125 where the non-skin-side core wrap sheet 109 and the back sheet 105 are bonded with the hot melt adhesive is provided over the entire longitudinal area of ​​the non-skin-side core wrap sheet 109. It is sufficient that at least a portion of the bonding region 125 is provided over the entire longitudinal area of ​​the non-skin-side core wrap sheet 109. In the longitudinal direction where tensile strength is high, having the hot melt adhesive application region 120 (bonding region 125) over the entire longitudinal area of ​​the skin-side core wrap sheet 108 (non-skin-side core wrap sheet 109) makes the skin-side core wrap sheet 108 (non-skin-side core wrap sheet 109) more tear-resistant.

[0094] In this embodiment, as described above, the skin-side core wrap sheet 108 of the skin-side composite sheet C3, which is arranged on the skin side of the absorbent core 103 in the thickness direction, is arranged adjacent to the skin side of the absorbent core 103. In addition, the non-skin-side core wrap sheet 109 of the non-skin-side composite sheet C4, which is arranged on the non-skin side of the absorbent core 103 in the thickness direction, is arranged adjacent to the non-skin side of the absorbent core 103. Because the absorbent core 103 swells when it absorbs liquid, if a core wrap sheet is provided to wrap around the absorbent core 103, the expansion of the absorbent core 103 applies force to the core wrap sheet, which may tear the core wrap sheet at the side portion wrapping the absorbent core 103. In this embodiment, the skin-side core wrap sheet 8 and the non-skin-side core wrap sheet 9 are arranged separately on the skin side and non-skin side, respectively, thereby reducing the load on the core wrap sheet and the risk of tearing.

[0095] As shown in Figure 13, the absorbent core 103 and the non-skin side core wrap sheet 109 have a core bonding region 127 where they are bonded to each other with hot melt adhesive. In this embodiment, three core bonding regions 127 are provided along the longitudinal direction, spaced apart in the width direction, but the number is not limited to this. A non-bonded region 126, where the non-skin side core wrap sheet 109 and the backsheet 105 are not bonded with hot melt adhesive, has an overlapping portion with the core bonding region 127. The non-bonded region 126, where hot melt adhesive is not applied, may have reduced strength, but by having an overlapping portion with the core bonding region 127, it is possible to prevent a decrease in the strength of the non-skin side core wrap sheet 109 of the non-skin side composite sheet C4.

[0096] ===Other=== The above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0097] In the first and second embodiments described above, the first core wrap sheet 38, the second core wrap sheet 39, the skin side core wrap sheet 108, and the non-skin side core wrap sheet 109 contain recycled pulp made from recycled disposable absorbent articles, but this is not limited to this. For example, the first absorbent core 33a, the second absorbent core 33b, and the absorbent core 103 may contain recycled pulp, or another sheet material constituting the absorbent article may contain recycled pulp. [Explanation of symbols]

[0098] 1 Absorbent pad (absorbent article) (first embodiment) 33 Absorbent 33a First absorbent core 33b Second absorbent core 34 Surface sheet (separate sheet) 35 Back sheet (separate sheet) 36 Exterior sheet 37 Side seat 38 First core wrap sheet 39 Second core wrap sheet 45a slit 45b slit 46 Pair of compression parts 48 Leakage barrier 60 Leak-proof wall elastic member 100 Diaper (absorbent article) (second embodiment) 101A Ventral waist 101B Inseam 101C Back waist 103 Absorbent Core 104 Surface sheet (separate sheet) 105 Back sheet (separate sheet) 106 Exterior Sheet 107 Side seat 108 Skin side core wrap sheet 109 Non-skin side core wrap sheet 110 Flap section 111 Base sheet 112 First fastening member 113 Second fastening member 114 Target Section 116 Leg elastic member 117 Inner leak-proof gathers 118 Outer leak-proof gathers 120 Application area 121 waist elastic member 122 Waist Gather 125 Junction area 126 Non-bonded area 127 Core Junction Area 171 Inner leak-proof elastic member 181 Outer leak-proof elastic member C1 First composite sheet (composite sheet) C2 Second composite sheet (composite sheet) C3 Skin-side composite sheet (composite sheet) C4 Non-skin side composite sheet (composite sheet)

Claims

1. an absorbent core; A core wrap sheet containing recycled pulp from disposable absorbent articles. An absorbent article comprising: The core wrap sheet is joined to a separate sheet adjacent to the core wrap sheet in the thickness direction of the absorbent article to form a composite sheet so that the core wrap sheet does not tear when the absorbent article is immersed in 0.9% physiological saline for 30 minutes, then removed, folded in half at the center of the longitudinal direction of the product, and hung for 10 minutes, or folded in half at the center of the width direction of the product, and hung for 10 minutes, The recycled pulp content in the core wrap sheet is less than 15% by weight, When the direction in which the tensile strength of the core wrap sheet is higher out of the longitudinal direction and the width direction of the absorbent article is defined as the tensile direction, When the composite sheet is pulled in the pulling direction, the tensile force per unit width at which the core wrap sheet in the composite sheet starts to break is higher than the tensile force per unit width at which the separate sheet starts to break when the separate sheet is pulled alone in the pulling direction. An absorbent article characterized by:

2. The absorbent article according to claim 1, a skin-side composite sheet, which is the composite sheet arranged on the skin side in the thickness direction of the absorbent core; and a non-skin-side composite sheet, which is the composite sheet arranged on the non-skin side in the thickness direction of the absorbent core, The core wrap sheet in the skin side composite sheet is a skin side core wrap sheet arranged adjacent to the skin side of the absorbent core, The core wrap sheet in the non-skin side composite sheet is a non-skin side core wrap sheet arranged adjacent to the non-skin side of the absorbent core. An absorbent article characterized by:

3. The absorbent article according to claim 1 or 2, the absorbent core comprises a superabsorbent polymer; The mass ratio of the superabsorbent polymer in the absorbent core is 28% or less. An absorbent article characterized by:

4. The absorbent article according to claim 1 or 3, a first absorbent core comprising at least a superabsorbent polymer; a second absorbent core comprising at least a superabsorbent polymer; and the mass ratio of the superabsorbent polymer contained in the first absorbent core is greater than the mass ratio of the superabsorbent polymer contained in the second absorbent core; A first core wrap sheet is provided, which is the core wrap sheet arranged so as not to wrap the first absorbent core, A second core wrap sheet is provided, which is the core wrap sheet that wraps the second absorbent core. An absorbent article characterized by:

5. The absorbent article according to any one of claims 1 to 4, The core wrap sheet contains a thermoplastic resin. An absorbent article characterized by:

6. The absorbent article according to claim 5, the separate sheet contains a thermoplastic resin, The core wrap sheet and the separate sheet are heat-sealed. An absorbent article characterized by:

7. The absorbent article according to claim 6, An absorbent article characterized in that the thermoplastic resin of the core wrap sheet and the thermoplastic resin of the separate sheet are the same type of thermoplastic resin.

8. The absorbent article according to claim 4, The core wrap sheet contains a thermoplastic resin, At least a portion of the core wrap sheet has an overlapping region where the core wrap sheets overlap each other in a plan view of the absorbent article in an unfolded state, The core wrap sheets are heat-sealed to each other in the overlapping region. An absorbent article characterized by:

9. An absorbent article according to any one of claims 1 to 8, The core wrap sheet and the separate sheet in the composite sheet are joined together with a hot melt adhesive. An absorbent article characterized by:

10. An absorbent article according to claim 9, The hot melt adhesive is applied in a planar manner at least in part. An absorbent article characterized by:

11. An absorbent article according to claim 9, The composite sheet has a non-bonded region where the core wrap sheet and the separate sheet are not bonded by the hot melt adhesive. An absorbent article characterized by:

12. An absorbent article according to claim 9 or 10, At least a portion of the bonding area where the core wrap sheet and the separate sheet are bonded by the hot melt adhesive is provided over the entire area in the tensile direction. An absorbent article characterized by:

13. The absorbent article according to claim 2, the separate sheet in the non-skin side composite sheet is a liquid-impermeable sheet member, In the non-skin side composite sheet, the non-skin side core wrap sheet and the separate sheet are joined by a hot melt adhesive. An absorbent article characterized by:

14. An absorbent article according to claim 2 or 13, the separate sheet of the non-skin side composite sheet is disposed adjacent to the non-skin side of the non-skin side core wrap sheet, the non-skin side composite sheet has a non-bonded region where the non-skin side core wrap sheet and the separate sheet are not bonded by a hot melt adhesive; the absorbent core and the non-skin side core wrap sheet have a core joining region where they are joined to each other by the hot melt adhesive; In a plan view of the absorbent article in an unfolded state, the non-bonded region has a portion overlapping with the core bonded region. An absorbent article characterized by:

15. The absorbent article according to any one of claims 2, 13, and 14, the separate sheet of the skin side composite sheet is a liquid-permeable sheet member, the separate sheet of the non-skin side composite sheet is a liquid-impermeable sheet member, When the non-skin side composite sheet is pulled in the pulling direction, the tensile force per unit width at which the core wrap sheet in the non-skin side composite sheet starts to break is higher than the tensile force per unit width at which the core wrap sheet in the skin side composite sheet starts to break when the skin side composite sheet is pulled in the pulling direction. An absorbent article characterized by:

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