Underpants type disposable diaper

Abstract

To provide an underpants type disposable diaper in which fixing property of a disposable absorbent pad is improved.SOLUTION: There is provided an underpants type disposable diaper in which a trunk region T is formed of a waist part W and a waist lower part U, the waist lower part U has a center region 30 positioned on a center in a width direction WD, a first region 31 defined as a region between one side seal part 21 and the center region 30, and a second region 32 defined as a region between the center region 30 and the other side seal part 21. The waist part W, the first region 31 and the second region 32 are a stretchable region having a maximum stretch rate of 160 to 320% in a first width direction WD. In a third region 33 between an interior body 10 and the waist part W in the center region 30, a pad fixing region 40 having a maximum stretch rate of less than 110% in a second width direction WD is provided.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a pants-type disposable diaper. [Background technology]

[0002] Pant-type (including trunk-type) disposable diapers have side seals where both sides of the front and back panels are welded together. The side seals have a number of welds spaced apart in a predetermined pattern. The side seals allow a flat assembly to be formed into a pant-like or trunk-like shape with a waist opening and leg openings.

[0003] In such pants-type disposable diapers, it is common to provide an elastic structure in the outer casing to improve the fit to the body. For example, diapers with an elastic structure in the torso region defined as the region between the side seals or in the intermediate region located between the front and rear torso regions have a relatively high fit to the body (see, for example, Patent Documents 1 and 2).

[0004] A typical stretch structure for an exterior body has an elongated or sheet-like elastic member between overlapping inner and outer sheet layers. The inner and outer sheet layers form a planar stretchable region and also serve to cover and conceal the elastic member, while the elastic member embedded between the inner and outer sheet layers serves to generate the force for elastic stretching. When the elastic member is stretched in the stretch direction, at least the portions located at both ends in the stretch direction are fixed to the inner and outer sheet layers. This fixation integrates the elastic member with the inner and outer sheet layers, and the inner and outer sheet layers contract due to the contractile force of the elastic member, forming pleats (including wrinkled pleats; these can be formed not only in their natural length state but also when the elastic member is stretched; hereinafter, simply referred to as pleats). When the sheet is stretched from this contracted state against the contractile force of the elastic member, the pleats unfold. Normally, when stretched to the elastic limit, the inner and outer sheet layers are in an unfolded state with no pleats, and as the elastic member contracts, they become pleated, with the densest pleats in the natural length state.

[0005] On the other hand, pants-type disposable diapers are sometimes used with disposable absorbent pads on the inner surface. Many of these disposable absorbent pads have hooks or adhesives of mechanical fasteners at least at the front and rear ends of the back surface as a means for fastening the pad to the inner surface of the pants-type disposable diaper (to prevent slippage).

[0006] However, in conventional pants-type disposable diapers, when the fastening means of the disposable absorbent pad are fastened closer to the waist opening than the front and rear edges of the inner body, the fastening means are pressed against the pleats formed on the inner surface of the stretchable region of the outer body, which reduces the contact area between the outer body and the fastening means, resulting in a problem that fastening is likely to be insufficient. When pants-type disposable diapers and disposable absorbent pads are used in combination, such a situation is likely to occur when a disposable absorbent pad that is relatively long in the front-to-back direction is used so that only the disposable absorbent pad needs to be replaced after excretion, when the disposable absorbent pad is fastened by mistake or intentionally shifting its position to one side, front or back, or when the pants-type disposable diaper is designed so that the dimension of the inner body in the front-to-back direction is short, and therefore improvement is desired. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-125042 [Patent Document 2] Japanese Patent Publication No. 2020-151257 Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide a pants-type disposable diaper which has excellent fixation of a disposable absorbent pad. [Means for solving the problem]

[0009] Disposable wearing articles that solve the above problems are as follows. <First aspect> An integrated outer body extending from the front body to the back body, or an outer body provided separately on the front body and the back body, An inner body including an absorbent body fixed to the outer body so as to extend from the front body to the back body; side seal portions at which both side portions of the exterior body of the front body and both side portions of the exterior body of the back body are joined together; It has a waist opening and a pair of left and right leg openings, the exterior body has a trunk region defined as a region between one of the side seal portions and the other of the side seal portions, The torso region comprises a waist portion extending along an upper edge from one of the side seal portions to the other of the side seal portions, and a lower waist portion extending adjacent to and below the waist portion from one of the side seal portions to the other of the side seal portions, The waist lower portion comprises a central region located at the center in the width direction, a first region defined as a region between one of the side seal portions and the central region, and a second region defined as a region between the other of the side seal portions and the central region, The front and rear edges of the interior body are located within the lower waist portion and spaced downward from the lower edge of the waist portion, the waist portion, the first region, and the second region are elastic regions having a first maximum widthwise elongation rate of 160 to 320%, The stretchable region includes an inner sheet layer, an outer sheet layer, and an elastic member provided between the inner sheet layer and the outer sheet layer, and is a region that elastically stretches between a natural length state in which the elastic member contracts in the width direction to form pleats on the inner surface, and an expanded state in which the elastic member stretches to the first maximum stretch rate in the width direction to form no pleats, A pad fixing region having a second maximum widthwise elongation rate of less than 110% is provided in a third region between the waist portion and the inner body in the central region. A pants-type disposable diaper characterized by:

[0010] (Action and effect) This pants-type disposable diaper has a pad fixing region above the front and rear edges of the inner body that has a second maximum widthwise elongation rate of less than 110% (i.e., non-stretchable or low-stretchable). This pad fixing region has almost no pleats, or even if there are pleats, they have little effect on the fixation of the disposable absorbent pad, resulting in superior fixation of the disposable absorbent pad compared to conventional pad fixing regions. Therefore, excellent fixation of the disposable absorbent pad is achieved even in cases where, for example, a relatively long disposable absorbent pad is used in combination with a pants-type disposable diaper so that only the disposable absorbent pad needs to be replaced after excretion, or where the disposable absorbent pad is fixed by accidentally or intentionally shifting its position to one side, front or rear, or where the pants-type disposable diaper is designed with a short front-to-rear dimension of the inner body.

[0011] <Second aspect> the pad fixing region is disposed midway between the third region in the front-rear direction, Of the third region, a fourth region between the pad fixing region and the waist portion, and a fifth region between the pad fixing region and the inner body are stretchable regions each having a maximum widthwise elongation rate greater than the second maximum widthwise elongation rate. A pants-type disposable diaper according to a first embodiment.

[0012] (Action and effect) Although the entire third region can be used as a pad fixing region, this may unnecessarily reduce the fit of the torso region. Therefore, as in this embodiment, it is preferable to position the pad fixing region in the middle of the third region in the front-to-rear direction, and to make the fourth and fifth regions on both the front and rear sides of the third region elastic regions each having a maximum widthwise elongation rate greater than the second maximum widthwise elongation rate.

[0013] <Third aspect> a plurality of the pad fixing regions are arranged at intervals in the front-rear direction at the middle of the third region in the front-rear direction, Of the third region, a fourth region between the pad fixing region and the waist portion, a fifth region between the pad fixing region and the inner body, and a sixth region between the pad fixing regions adjacent in the front-rear direction are stretchable regions each having a maximum widthwise elongation rate greater than the second maximum widthwise elongation rate. A pants-type disposable diaper according to a first embodiment.

[0014] (Action and effect) If only one pad fixing region is provided in the third region, the dimension of the pad fixing region in the front-to-back direction needs to be long to allow the user to select the pad fixing position according to their body type, preferences, or pad length, but this may result in a decrease in fit. In contrast, if multiple pad fixing regions are provided at intervals in the front-to-back direction as in this embodiment and the remaining portions are made stretchable regions, it is possible to select the pad fixing position while suppressing a decrease in fit in the torso region.

[0015] <Fourth aspect> the maximum widthwise elongation rate of the portions of the first region and the second region located on the sides of the pad fixing region is 1 to 1.5 times the maximum widthwise elongation rate of the other portions; The pants-type disposable diaper according to the second or third aspect.

[0016] (Action and effect) In the second embodiment having the fourth and fifth regions and the third embodiment having the fourth to sixth regions, the widthwise contraction rate (the reciprocal of the maximum elongation rate) in the natural length state in the lower waist portion is low in the region consisting of the pad fixing region and the portions located on both sides thereof, and high in other regions (i.e., the fourth and fifth regions in the second embodiment and the fourth to sixth regions in the third embodiment). In this case, in the natural length state before wearing, the widthwise dimension of the region consisting of the pad fixing region and the portions located on both sides thereof is larger than that of the other regions, and this excess dimension appears as a bulge that continues in the widthwise direction. This appearance may be undesirable, and the bulge may provide a poorer fit when worn than the other regions. In contrast, with the present configuration, the width of the area consisting of the pad fixing area and the areas located on both sides of it becomes closer to the other areas, and the excess bulge in this area is reduced, resulting in a good appearance in the natural length state as well as a good fit when worn.

[0017] <Fifth aspect> The pad fixing region is an elliptical region having a major axis along the width direction. The pants-type disposable diaper according to any one of the second to fourth aspects.

[0018] (Action and effect) When the shape of the pad fixing area is oval, the change in the shrinkage rate in the width direction in the pad fixing area becomes more gradual and continuous, so that the change in appearance and fit from the pad fixing area to the adjacent areas above and below it (i.e., areas 4 and 5 in the second embodiment described above, and areas 4 to 6 in the third embodiment described above) becomes gradual and preferable.

[0019] <Sixth aspect> The width direction dimension of the central region is 0.3 to 1 times the width direction dimension of the inner body, The width of the pad fixing region is 0.3 to 1 times the width of the central region. A pants-type disposable diaper according to any one of the first to fifth aspects.

[0020] (Action and effect) The dimensions and arrangement of each part can be determined as appropriate, but in normal cases it is preferable that they are within the range of this embodiment.

[0021] <Seventh aspect> The elastic members are a plurality of elongated elastic members attached at intervals in the front-rear direction and extending along the width direction, In the first region and the second region, the inner sheet layer and the outer sheet layer are joined together by a hot melt adhesive at least at both end portions of the elongated elastic members, and the elongated elastic members are fixed to the inner sheet layer and the outer sheet layer, The pad fixing region has an inner sheet layer and an outer sheet layer continuing from the first region and the second region, and an independent contracted portion left between the inner sheet layer and the outer sheet layer, where the elongated elastic member continuing from the first region and the second region has contracted without being accompanied by the inner sheet layer and the outer sheet layer, the pad fixing region has a plurality of cutting portions for cutting at least one of the inner sheet layer and the outer sheet layer, the cutting portions being formed so as to intersect with a plurality of imaginary straight lines connecting the elongated elastic members in the first region and the elongated elastic members in the second region along the width direction, The cutting portion is provided at only one location on each virtual straight line, the cut portion intersecting one of a pair of imaginary straight lines adjacent to each other in the front-rear direction is at a different position in the width direction from the cut portion intersecting the other imaginary straight line; A pants-type disposable diaper according to any one of the first to sixth aspects.

[0022] (Action and effect) When regions with different maximum elongation rates are aligned in the width direction of the torso region, it is possible to form the torso region by connecting assemblies with different maximum elongation rates, but from the viewpoint of ease of manufacturing, it is preferable to attach elastic members continuously along the width direction to the outer cover and to reduce the maximum elongation rate by partially or completely eliminating or reducing the stretchability generated by the elastic members in specific regions. Therefore, in the first to third regions of this pants-type disposable diaper, it is preferable to attach elastic members continuously in the width direction from one side seal portion to the other side seal portion and to partially or completely eliminate or reduce the stretchability generated by the elastic members only in the pad fixing region, thereby reducing the maximum elongation rate and making the regions other than the pad fixing region into a stretchable region.

[0023] When elongated elastic members are used as the elastic members for the trunk region and the elastic members are fixed to the inner and outer sheet layers with a hot-melt adhesive and the inner and outer sheet layers are joined, there are two main methods for eliminating or reducing stretchability, either of which can be adopted. The first method involves continuously fixing the elongated elastic members to the inner and outer sheet layers in the width direction and cutting the elongated elastic members at multiple locations spaced apart in the front-to-back and width directions in a specific region. The second method involves forming independent contraction portions in the elongated elastic members located in the specific region, either unfixed or weakly fixed to the inner and outer sheet layers with a hot-melt adhesive, and cutting the independent contraction portions at a single location midway in the width direction, allowing the independent contraction portions to shrink to their natural length or nearly so without being attached to the inner and outer sheet layers. The second method has the advantage of requiring fewer cuts than the first method.

[0024] In addition, as a method for cutting an elongated elastic member, in addition to a method in which the elongated elastic member is sandwiched between an inner sheet layer and an outer sheet layer and pressurized with heat (such as ultrasonic welding or heat embossing) at the cutting position, a method in which the elongated elastic member is sandwiched between the inner sheet layer and the outer sheet layer and cuts the elongated elastic member and at least one of the inner sheet layer and the outer sheet layer with a cutting blade at the cutting position is also known.

[0025] However, when forming the pad fixing region using the second method using a cutting blade, if the cut portions are positioned on a straight line along the front-to-rear direction, there is a risk that the pad fixing region will tear along the cut portions like perforations. In contrast, as in the present embodiment, if the cut portion that intersects with one of a pair of virtual lines adjacent in the front-to-rear direction is positioned at a different widthwise position from the cut portion that intersects with the other virtual line, the risk of such tearing of the pad fixing region can be reduced.

[0026] <Eighth aspect> The elastic members are a plurality of elongated elastic members attached at intervals in the front-rear direction and extending along the width direction, In the first region and the second region, the inner sheet layer and the outer sheet layer are joined together by a hot melt adhesive at least at both end portions of the elongated elastic members, and the elongated elastic members are fixed to the inner sheet layer and the outer sheet layer, The pad fixing region has an inner sheet layer and an outer sheet layer continuing from the first region and the second region, and an independent contracted portion left between the inner sheet layer and the outer sheet layer, where the elongated elastic member continuing from the first region and the second region has contracted without being accompanied by the inner sheet layer and the outer sheet layer, the pad fixing region has a plurality of cutting portions for cutting at least one of the inner sheet layer and the outer sheet layer, the cutting portions being formed so as to intersect with a plurality of imaginary straight lines connecting the elongated elastic members in the first region and the elongated elastic members in the second region along the width direction, the pad fixing region has an imaginary straight line that intersects with the cut portion and an imaginary straight line that does not intersect with the cut portion, the pad fixing region has the independent contraction portions at both ends of an imaginary straight line that intersects with the cut portion, and has an elongated elastic member that extends from the first region through the pad fixing region to the second region along an imaginary straight line that does not intersect with the cut portion. A pants-type disposable diaper according to any one of the first to sixth aspects.

[0027] (Action and effect) In order to make the maximum elongation rate of the pad fixing area nearly 100%, it is preferable to place a cut section on each virtual straight line as in the seventh embodiment, but if this is not the case, it is also preferable to thin out the cut sections as in this embodiment, thereby retaining elasticity in the pad fixing area and preventing a decrease in the fit of the pad fixing area.

[0028] <Ninth Aspect> The pad fixing region has a joining portion where the inner sheet layer and the outer sheet layer are joined at a position where the elastic member is not present. The pants-type disposable diaper according to any one of the first to eighth aspects.

[0029] (Action and effect) The present embodiment is preferable because it has a joint between the inner sheet layer and the outer sheet layer, which improves the strength of the pad fixing region. The improvement in strength due to the joint between the inner sheet layer and the outer sheet layer is particularly preferable when the sheet has the cut portion described above.

[0030] <Tenth Aspect> The front-to-back dimension of the third region is 0.3 to 0.9 times the front-to-back dimension of the torso region. The pants-type disposable diaper according to any one of the first to ninth aspects.

[0031] (Action and effect) If the front-to-back dimension of the third region is short, there is some merit in providing a pad fixing region, but it is less necessary; therefore, when the front-to-back dimension of the third region is relatively large, as in this embodiment, the need for a pad fixing region becomes greater. [Effects of the Invention]

[0032] According to the present invention, the fixation of the disposable absorbent pad is excellent. [Brief explanation of the drawings]

[0033] [Figure 1] 1 is a plan view (inner surface side) of a pants-type disposable diaper in an unfolded state. [Figure 2] 1 is a plan view (outer surface side) of a pants-type disposable diaper in an unfolded state. [Figure 3] 4 is a cross-sectional view taken along line 4-4 of FIG. 1. [Figure 4] 5 is a cross-sectional view taken along line 5-5 of FIG. 1. [Figure 5] 6 is a cross-sectional view taken along line 6-6 of FIG. 1. [Figure 6] FIG. 2 is a plan view showing only the main part of FIG. 1. [Figure 7] FIG. 1 is a perspective view showing a method for attaching a disposable absorbent pad to a pants-type disposable diaper. [Figure 8] FIG. 1 is a perspective view of a pants-type disposable diaper in a worn state. [Figure 9] FIG. 2 is an enlarged plan view showing only the main part of FIG. [Figure 10] 10(a) and 10(b) are both enlarged plan views showing only the main parts of another example. [Figure 11] FIG. 10 is an enlarged plan view showing only the main parts of another example. [Figure 12] 7A is an enlarged plan view showing only the main part of another example, and FIG. 7B is a cross-sectional view taken along line 7-7. [Figure 13] 7A is an enlarged plan view showing only the main part of another example, and FIG. 7B is a cross-sectional view taken along line 7-7. [Figure 14] 10(a) and 10(b) are both enlarged plan views showing only the main parts of another example. [Figure 15] FIG. 2 is a plan view showing the back surface of the disposable absorbent pad. [Figure 16] FIG. 2 is a plan view showing the back surface of the disposable absorbent pad. DETAILED DESCRIPTION OF THE INVENTION

[0034] An example of a pants-type disposable diaper will be described in detail below with reference to the accompanying drawings. Note that the dotted patterns in the drawings indicate adhesive used as a joining means for joining the respective components located on the front and back sides. This adhesive can be applied, for example, by solid, bead, curtain, summit, or spiral application of hot melt adhesive, or by pattern coating (transfer of hot melt adhesive using a relief printing method). Alternatively or in addition to these, hot melt adhesive can be applied to the outer surface of the elastic member using a comb gun or SureWrap application. Hot melt adhesives include, for example, EVA-based, adhesive rubber-based (elastomer-based), polyolefin-based, and polyester / polyamide-based adhesives, but no particular limitation is imposed on the type. Material welding, such as heat sealing or ultrasonic sealing, can also be used to join the respective components.

[0035] Furthermore, as the nonwoven fabric in the following description, known nonwoven fabrics can be used as appropriate depending on the location and purpose. The constituent fibers of the nonwoven fabric can be selected without particular limitation, for example, synthetic fibers such as polyolefins (e.g., polyethylene or polypropylene), polyesters, and polyamides (including single-component fibers as well as core-sheath and other composite fibers), regenerated fibers (e.g., rayon or cupra), and natural fibers (e.g., cotton), and mixtures of these can also be used. To increase the flexibility of the nonwoven fabric, it is preferable to use crimped fibers as the constituent fibers. Furthermore, the constituent fibers of the nonwoven fabric may be hydrophilic fibers (including those made hydrophilic by a hydrophilizing agent), hydrophobic fibers, or water-repellent fibers (including those made water-repellent by a water-repellent agent). Furthermore, nonwoven fabrics are generally classified according to the fiber length, sheet formation method, fiber bonding method, and laminate structure into staple fiber nonwoven fabrics, long fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, thermal bond (air-through) nonwoven fabrics, needle-punched nonwoven fabrics, point-bonded nonwoven fabrics, and laminated nonwoven fabrics (including SSS nonwoven fabrics in which identical or similar nonwoven fabric layers are laminated, as well as SMS nonwoven fabrics and SMMS nonwoven fabrics in which different nonwoven fabric layers are laminated, in which a meltblown layer is sandwiched between spunbond layers), and any of these nonwoven fabrics can be used. A laminated nonwoven fabric means a nonwoven fabric manufactured as an integrated nonwoven fabric including all layers, and which has been subjected to a fiber bonding process across all layers, and does not include a nonwoven fabric made separately and bonded together by a bonding means such as a hot melt adhesive.

[0036] 1 to 6 show an example of a pants-type disposable diaper. This pants-type disposable diaper (hereinafter simply referred to as a diaper) has an outer body 20 that extends continuously from a front body F to a back body B, and an inner body 10 that is fixed to the outer body 20 so as to extend from the front body F to the back body B. The inner body 10 has an absorber 18 between a liquid-permeable top sheet 11 and a liquid-impermeable sheet 12. During manufacturing, the back surface of the inner body 10 is joined to the inner surface (top surface) of the outer body 20 using a joining means such as a hot melt adhesive (shown as the dotted pattern in FIG. 2). Then, the inner body 10 and the outer body 20 are folded at the center in the longitudinal direction LD (lengthwise direction) that is the boundary between the front body F and the back body B, and both side edges are joined together by thermal welding, ultrasonic welding, or the like to form a side seal portion 21. The formation of this side seal portion 21 results in a pants-type disposable diaper having a waist opening WO and a pair of left and right leg openings LO. The left and right are based on the wearer when wearing the diaper. The front body F refers to the entire area in front of the center of the diaper in the front-to-back direction LD, and the back body B refers to the entire area in back of the diaper in the front-to-back direction LD.

[0037] (Example of interior body structure) As shown in Figures 3 to 5, the inner body 10 comprises an absorbent body 18 between a top sheet 11 and a liquid-impermeable sheet 12, and the absorbent body 18 absorbs and retains excrement that has permeated the top sheet 11. There are no particular restrictions on the planar shape of the inner body 10, but it is generally a substantially rectangular shape as shown in the figures.

[0038] (absorber) The absorbent body 18 may have a single-layer structure or a multi-layer structure. The absorbent body 18 is a member containing superabsorbent polymer particles, and is preferably a mixture of pulp fibers and superabsorbent polymer particles. The absorbent body 18 may be wrapped in a wrapping sheet 14, such as crepe paper, that has liquid permeability and liquid retention properties to maintain the shape and retain the polymer.

[0039] The superabsorbent polymer particles can be those used in this type of absorbent article as they are. For example, it is desirable that the proportion of particles remaining on a 500 μm standard sieve (JIS Z8801-1:2006) when sieved (shaken for 5 minutes) is 30% by weight or less, and it is also desirable that the proportion of particles remaining on a 180 μm standard sieve (JIS Z8801-1:2006) when sieved (shaken for 5 minutes) is 60% by weight or more.

[0040] The superabsorbent polymer particles are not particularly limited, but those with a water absorption speed of 35 to 60 seconds and a water absorption capacity of 50 to 70 g / g can be suitably used. Examples of superabsorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based particles, and those such as starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked products of sodium carboxymethylcellulose, and acrylic acid (salt) polymers can be suitably used. The basis weight of the superabsorbent polymer particles can be determined appropriately depending on the absorption capacity required for the product. Therefore, although it is not possible to generalize, it is generally preferred to use particles of 100 to 350 g / m. 2 It can be said that:

[0041] The shape of the absorber 18 can be determined as appropriate, and can be rectangular, but is preferably shaped to have a narrower constricted portion 13 in the crotch area than the front and rear sides. The dimensions of the constricted portion 13 can be determined as appropriate, but the width of its narrowest portion can be approximately 40 to 60% of the overall width of the absorber 18. The crotch area refers to the middle portion when the area between the torso region T of the front body F and the torso region T of the back body B is divided into three equal parts in the front-to-back direction.

[0042] The top sheet 11 placed on the front side (skin contact side) of the absorbent body 18 is preferably made of a perforated or non-perforated nonwoven fabric or a perforated plastic sheet. There are no particular restrictions on the nonwoven fabric used for the top sheet 11, but if a soft feel is important, a short fiber nonwoven fabric bonded by hydroentangling, hot air bonding, or the like is preferred. If a large number of through-holes are formed in the top sheet 11, urine and the like will be absorbed quickly. In the illustrated embodiment, the top sheet 11 wraps around the side edges of the absorbent body 18 and extends to the back side of the absorbent body 18.

[0043] The liquid-impermeable sheet 12 covering the back side (non-skin contact side) of the absorbent body 18 is typically a liquid-impermeable plastic sheet such as polyethylene or polypropylene, although in recent years, moisture-permeable sheets have been preferred to prevent stuffiness. A suitable example of this water-proof / moisture-permeable sheet is a microporous sheet obtained by melt-kneading inorganic fine particles such as calcium carbonate into an olefin resin such as polyethylene or polypropylene to form a sheet, and then stretching the sheet uniaxially or biaxially. In the illustrated embodiment, the liquid-impermeable sheet 12 is folded back to the back side of the absorbent body 18 together with the top sheet 11 on both sides in the width direction WD, but the structure is not limited to this and other known structures can be used.

[0044] Three-dimensional gathers BS are formed on both sides of the inner body 10, primarily to fit around the legs. As shown in Figures 4 and 5, these three-dimensional gathers BS are formed by folding back a gathered sheet 15, which consists of a fixed portion fixed to the side of the back surface of the inner body 10, a main portion extending from this fixed portion along the side of the inner body 10 to the side of the front surface of the inner body 10, a collapsed portion formed by fixing the front and rear ends of the main portion to the side of the front surface of the inner body 10 in a collapsed state, and a free portion formed by leaving the space between the collapsed portions unsecured. Elongated gathered elastic members 16 are disposed between the double sheets, such as at the tips of the free portions. With this structure, the free portions of the three-dimensional gathers BS, which protrude beyond the absorbent body edge due to contraction of the gathered elastic members 16, rise up in the finished state as shown by the two-dot chain line in Figure 4. A water-repellent nonwoven fabric is preferably used as the gathered sheet 15.

[0045] The gathered elastic member 16 can be made of commonly used materials such as styrene rubber, polyolefin rubber, urethane rubber, ester rubber, polyurethane, polyethylene, polystyrene, styrene butadiene, silicone, polyester, etc. To make it difficult to see from the outside, it is recommended that the thickness be 925 dtex or less, the tension be 150-350%, and the spacing be 7.0 mm or less. The gathered elastic member 16 can be in the form of a thread as shown in the figure, or a tape-like member of a certain width.

[0046] As with the top sheet 11, various materials can be used for the material fibers constituting the aforementioned gathered sheet 15, but nonwoven fabric is preferred, and in particular, nonwoven fabric with excellent breathability and low basis weight is used to prevent stuffiness. Furthermore, for the gathered sheet 15, it is desirable to use a water-repellent nonwoven fabric coated with a silicone-based, paraffin metal-based, or alkylchromic chloride-based water repellent agent in order to prevent permeation of urine and the like, prevent rashes, and improve the feel on the skin (dry feeling).

[0047] (Example of exterior structure) 3 to 5, the exterior body 20 is continuous across the front body F and the back body B, and has a planar shape (approximately hourglass-like overall) with concave leg lines 29 formed on both side edges midway in the front-to-back direction LD to form leg openings LO, but is not limited to this. The exterior body 20 may be provided separately on the front body F and the back body B, and the exterior body 20 on the front body F and the exterior body 20 on the back body B may be spaced apart in the front-to-back direction LD at the crotch area.

[0048] The exterior body 20 has a torso region T defined as the region between one side seal portion 21 and the other side seal portion 21. The exterior body 20 in the illustrated example is continuous across the front body portion F and the back body portion B, and therefore has an intermediate region L defined as the region between the torso region T of the front body portion F and the torso region T of the back body portion B, but if the exterior body 20 is provided separately on the front body portion F and the back body portion B as described above, at least one of the front body portion F and the back body portion B may not have an intermediate region L (in other words, at least one of the front body portion F and the back body portion B may be the entire torso region T).

[0049] The torso region T is composed of a waist region W extending from one side seal region 21 to the other side seal region 21 along the upper edge, and a lower waist region U extending from one side seal region 21 to the other side seal region 21 adjacent to the bottom of the waist region W. Typically, if the torso region T has a boundary where stretchability in the width direction WD changes (for example, where the thickness or maximum elongation rate of the elastic members changes), the waist region W will be above the uppermost boundary (on the waist opening WO side). (If there is a gap between the lowermost elastic member of the waist region and the lower waist region U and the uppermost elastic member, the boundary will be the center of that gap.) The length of these regions in the front-to-back direction LD can be determined appropriately depending on the size of the product. For example, the waist region W may be 15 to 40 mm, and particularly 20 to 40 mm.

[0050] The exterior body 20 has an inner sheet layer 22, an outer sheet layer 23, and elastic members 24-26 disposed between the inner sheet layer 22 and the outer sheet layer 23. In the example shown in Figures 3-5, the exterior body 20 has a presser sheet 20A and a back sheet 20B. In the lower waist region U, the inner sheet layer 22 is formed by the presser sheet 20A, and the outer sheet layer 23 is formed by the back sheet 20B. In the waist region W, the inner sheet layer 22 and the outer sheet layer 23 are respectively formed by the inner and outer portions of the back sheet 20B folded back at the edge of the waist opening WO. The presser sheet 20A in the illustrated example may be omitted, and the folded-back portion 20C of the back sheet 20B in the figures may be extended toward the crotch, with all elastic members sandwiched between the sheets in the folded-back portion 20C. Alternatively, all elastic members may be sandwiched between the presser sheet 20A and the back sheet 20B regardless of whether the folded-back portion 20C is provided. When the elastic member is stretched in the stretch direction, at least the portions located at both ends in the stretch direction are fixed to the inner sheet layer 22 contacting the inside of the elastic member and the outer sheet layer 23 contacting the outside of the elastic member. As a result, the elastic member is integrated with the inner sheet layer 22 and the outer sheet layer 23, and the stretch region of the exterior body 20 elastically stretches and contracts between a natural length state in which the inner and outer surfaces of the inner sheet layer 22 and the outer sheet layer 23 are folded due to contraction by the contraction force of the elastic member, and an expanded state in which the pleats are removed by extension together with the elastic members 24 to 26. Normally, the inner sheet layer 22 and the outer sheet layer 23 are in an expanded state with no pleats at the elastic stretch limit, and they become folded as the elastic member contracts, with the natural length state being the most densely folded.

[0051] In such an elastic structure, if the inner sheet layer 22 and the outer sheet layer 23 are free from each other, one sheet layer may partially or entirely float relative to the other sheet layer, causing unnecessary folds or bulges, which may lead to poor fit or slippage when worn. Therefore, it is preferable that the inner sheet layer 22 and the outer sheet layer 23 are directly or indirectly bonded over almost their entirety.

[0052] As shown in FIGS. 1 and 3 , a cover sheet 50 may be provided to cover the front and rear ends of the inner body 10 attached to the inner surface of the outer body 20 and to prevent leakage from the front and rear edges of the inner body 10. More specifically, the cover sheet 50 extends across the entire width direction WD from the inner surface of the folded-back portion 20C located at the end of the front body F closest to the waist opening WO to where it overlaps with the front end of the inner body 10, and from the inner surface of the folded-back portion 20C located at the end of the back body B closest to the waist opening WO to where it overlaps with the rear end of the inner body 10. When such a cover sheet 50 is provided, the inner surface of the torso region T of the outer body 20 is formed by the cover sheet 50. The folded-back portion 20C, formed by folding the outer body 20 onto the inner surface of the diaper, may also be extended to the portion where it overlaps with the inner body 10 to form a portion equivalent to the cover sheet 50 shown in the illustration. In this case, the folded-back portion 20C forms the inner surface of the outer body 20. The cover sheet 50 is bonded continuously or intermittently over the entire area including at least the pad fixing area 40 described below by a welding means such as a hot melt adhesive, ultrasonic welding or heat sealing.

[0053] As the elastic members 24 to 26, in addition to elongated elastic members 24 to 26 such as rubber threads and flat rubber, elastic sheets such as elastic films can also be used.

[0054] An adhesive such as a hot melt adhesive is preferably used as a means for fixing the elastic members 24-26 to the inner sheet layer 22 and the outer sheet layer 23. The inner sheet layer 22 and the outer sheet layer 23 can be joined together using a hot melt adhesive, or, to reduce the amount of hot melt adhesive used, the inner sheet layer 22 and the outer sheet layer 23 can be welded together by ultrasonic welding, heat sealing, or the like. For example, when the elastic members 24-26 are elongated elastic members 24-26 such as rubber thread, joining the inner sheet layer 22 and the outer sheet layer 23 with a hot melt adhesive at the positions where the elongated elastic members 24-26 pass can serve to both join the inner sheet layer 22 and the outer sheet layer 23 and fix the elongated elastic members 24-26 to the inner sheet layer 22 and the outer sheet layer 23. In this case, to reinforce the fixation of the elongated elastic members 24-26, additional hot melt adhesive can be applied only to predetermined regions including both end portions of the elongated elastic members 24-26. Alternatively, only predetermined regions including both end portions of the elongated elastic members 24-26 can be fixed to the inner sheet layer 22 and the outer sheet layer 23 with hot melt adhesive, and the inner sheet layer 22 and the outer sheet layer 23 can be joined by ultrasonic welding or other welding means at locations other than those through which the elongated elastic members 24-26 pass. When the elastic members 24-26 are elastic sheets such as elastic films, the inner sheet layer 22 and the outer sheet layer 23 can be joined directly or indirectly via the elastic sheet at multiple joints arranged at intervals. A direct joint is one in which a through hole is provided in the elastic sheet in the thickness direction, and the inner sheet layer 22 and the outer sheet layer 23 are joined only within the through hole, while an indirect joint is one in which no through hole is provided in the elastic sheet, and the inner sheet layer 22 and the outer sheet layer 23 are joined via the elastic sheet.

[0055] Nonwoven fabrics are suitable for the constituent sheets of the exterior body 20 (in the illustrated example, the aforementioned back sheet 20B, pressing sheet 20A, and cover sheet 50) from the viewpoint of breathability and texture, but any material can be used as long as it can be welded at the side seal portion 21. For example, other materials, such as thermoplastic resin sheets such as elastic films, can be used instead of or in addition to the nonwoven fabric. When using nonwoven fabric, it is recommended that the fineness be 1 to 3 dtex and the basis weight be 10 to 25 g / m. 2 A spunbond nonwoven fabric of this order is preferred, but staple fiber nonwoven fabrics can also be used for some or all of the layers. Furthermore, the constituent sheets of the exterior body 20 can be ordinary nonwoven fabrics that have almost no elastic stretch (maximum stretch rate in the width direction WD of less than 110%), as well as sheets with a certain degree of stretchability (maximum stretch rate in the width direction WD of 200% or more), such as stretchable nonwoven fabrics made of elastomeric fibers or elastic films. Regardless of the type of constituent sheet used for the exterior body 20, however, it is a prerequisite that the stretchable region of the exterior body 20 is at least at its natural length (preferably even when stretched to half of its maximum stretch rate), and that pleats are formed on at least the inner surface of the exterior body 20.

[0056] To explain the illustrated example in more detail, in each of the front body F and the back body B, a plurality of elongated waist elastic members 24 extending in the width direction WD are arranged at intervals in the front-to-back direction LD in the waist portion W of the outer cover 20, and a plurality of elongated lower waist elastic members 25 extending in the width direction WD are arranged at intervals in the front-to-back direction LD in the lower waist portion U. The waist elastic members 24 are mainly used to tighten the edge of the waist opening WO of the diaper to prevent the diaper from slipping down or leaking, while the lower waist elastic members 25 are mainly used to improve the fit of the diaper around the waist over a wide area.

[0057] In the illustrated example, the lower waist region U and middle region L of the outer casing 20 are provided with a plurality of elongated curved elastic members 26 in each of the front and back trunk sections F and B. The curved elastic members 26 extend in a curved pattern from one side seal section 21 along one leg opening LO toward the crotch region, across the crotch region, and then along the other leg opening LO to the other side seal section 21. The curved elastic members 26 are primarily intended to improve the fit of the diaper around the legs and in the crotch region. Unlike the illustrated example, the curved elastic members 26 may be provided on only one of the front trunk section F and the back trunk section B, or may not be provided on both. Furthermore, when the curved elastic members 26 are provided on both the front trunk section F and the back trunk section B, the entire group of curved elastic members 28 arranged on the front trunk section F and the entire group of curved elastic members 26 arranged on the back trunk section B may be spaced apart in the front-to-back direction LD without intersecting each other, or some of the curved elastic members 26 may intersect each other (not shown).

[0058] The elongated elastic members 24-26 are spaced apart to form a predetermined stretchable region, and are fixed in a stretched state at a predetermined stretch rate along each continuous direction. As a result, stretchable regions are formed in the torso region T and the intermediate region L. Of these, the section having only the waist elastic member 24 and the lower waist elastic member 25 elastically stretches in the direction along the waist elastic member 24 and the lower waist elastic member 25, the section having only the curved elastic member 26 elastically stretches in the direction along the curved elastic member 26, and the section having the waist elastic member 24, the lower waist elastic member 25, and the curved elastic member 26 elastically stretches not only in the width direction WD but also in the direction along the curved elastic member 26. The maximum stretch rate of each section can be adjusted by the thickness, number, spacing, and stretch rate of the elastic members 24-26 when attached, etc. In particular, the thickness, number, and spacing of the elastic members 24-26 should be selected so that the maximum elongation of a particular portion of the outer body 20 is approximately equal to the elongation of the elastic members 24-26 at the time of attachment when the inner body 10 is unfastened or removed (for example, 80% or more, more preferably 90% or more of the elongation at the time of attachment). As an example, in the case of a pants-type disposable diaper for adults, the maximum elongation of the waist region W and lower-waist region U in the width direction WD can be approximately 160-320%, and the maximum elongation of the portion having only the curved elastic members 26 in the direction along the curved elastic members 26 can be approximately 230-320%. The thickness, number and spacing in the front-to-back direction LD of the waist elastic members 24 can be determined as appropriate. As an example, the thickness of the waist elastic members 24 can be approximately 620 to 1240 dtex, the number of strands can be approximately 5 to 10, and the spacing in the front-to-back direction LD can be approximately 4 to 8 mm; the thickness of the lower waist elastic members 25 can be approximately 310 to 940 dtex, the number of strands can be approximately 7 to 25, and the spacing in the front-to-back direction LD can be approximately 5 to 20 mm; and the thickness of the curved elastic members 26 can be approximately 310 to 940 dtex, the number of strands can be approximately 3 to 10, and the spacing in the perpendicular direction can be approximately 3 to 10 mm.

[0059] (Pad fixing area) 6 and 9, the front and rear edges of the inner body 10 are located within a lower waist region U and spaced downward from the lower edge of the waist region W. The lower waist region U is comprised of a central region 30 located in the center of the width direction WD, a first region 31 defined as the region between one side seal portion 21 and the central region 30, and a second region 32 defined as the region between the other side seal portion 21 and the central region 30. At least the waist region W, first region 31, and second region 32 are stretchable regions having a maximum elongation rate in the first width direction WD of 160 to 320%, and a third region 33 within the central region 30, between the waist region W and the inner body 10, has a pad fixing region 40 having a maximum elongation rate in the second width direction WD of less than 110%. The waist region W, first region 31, and second region 32 may have the same maximum elongation rate in the width direction WD or may have different maximum elongation rates in the width direction WD. As an example, the maximum elongation rate in the width direction WD of the waist portion W can be 0.8 to 1.2 times the maximum elongation rate in the width direction WD of the first region 31 and the second region 32. The maximum elongation rate of a specific portion of the exterior body 20 can be determined as the elongation rate at the elastic limit (at 1 N when the elastic limit cannot be clearly determined) by removing the interior body 10 from the exterior body 20, cutting out a test piece consisting of the specific portion of the exterior body 20 and the gripping portions adjacent to both sides of the specific portion in the width direction WD, and conducting a tensile test by gripping the gripping portions of this test piece with the gripping tools of a tensile tester.

[0060] Since the pad fixing region 40 has a maximum elongation rate in the second width direction WD of less than 110% (i.e., non-stretchable or low-stretchable), there are almost no pleats on at least the inner surface of the pad fixing region 40 of the exterior body 20, or even if there are pleats, they have little effect on the fixation of the disposable absorbent pad 60. Therefore, when a disposable absorbent pad 60 having a fixing means 61 on its back surface is placed on the inner surface of a pants-type disposable diaper 100 and the fixing means 61 of the disposable absorbent pad 60 is pressed against the inner surface as shown in Fig. 7, the pants-type disposable diaper 100 has better fixation of the disposable absorbent pad 60 than conventional pants-type disposable diapers. Fig. 8 shows the pants-type disposable diaper 100 shown in Fig. 1 etc., with the disposable absorbent pad 60 attached when worn. It is preferable that the pad fixing region 40 has no stretchability in any direction other than the width direction WD.

[0061] Of the inner surface of the exterior body 20, at least the portion having the pad fixing region 40 (preferably the entirety) is formed from a material that can fix the fixing means 61 of the disposable absorbent pad 60 when pressed against it. In this regard, the material of the inner surface of the pad fixing region 40 is not particularly limited, but since the inner surface of the pad fixing region 40 is also the surface that comes into contact with the skin, it can be attached to hook materials of mechanical fasteners that are widely used as the fixing means 61 of disposable absorbent pads 60, and it can also be attached to adhesive layers that are widely used as the fixing means 61 of disposable absorbent pads 60. In this respect, various synthetic fiber nonwoven fabrics can be suitably used, and in particular, from the viewpoint of strength, spunbond nonwoven fabrics in which fibers are thermally bonded can be suitably used.

[0062] The dimensions of the pad fixing region 40 are preferably determined so as to have an area large enough to fix the fixing means 61 of the disposable absorbent pad 60. The pad fixing region 40 may be larger or smaller than the fixing means 61 of the disposable absorbent pad 60 (i.e., the fixing means 61 of the disposable absorbent pad 60 may extend beyond the pad fixing region 40). For example, as in the example of a disposable absorbent pad 60 shown in Figure 15, etc., which has fixing means 61 such as hook materials of mechanical fasteners at the front and rear ends, is designed so that the entire fixing means 61 is fixed, so it is preferable that the dimension 40y (maximum value if it varies depending on the position) in the front-to-back direction LD of the pad fixing area 40 is greater than or equal to the dimension 61y (maximum value if it varies depending on the position) in the front-to-back direction LD of the fixing means 61 of the disposable absorbent pad 60, and in particular 1.1 to 1.5 times, and it is preferable that the dimension 40x (maximum value if it varies depending on the position) in the width direction WD of the pad fixing area 40 is greater than or equal to the dimension 61x (maximum value if it varies depending on the position) in the width direction WD of the fixing means 61 of the disposable absorbent pad 60, and in particular 1.1 to 1.5 times. On the other hand, as in the example of the disposable absorbent pad 60 shown in Fig. 16, when the fixing means 61, such as an adhesive, is provided over the entire front-to-rear direction LD of the disposable absorbent pad 60, the dimension 40x in the width direction WD of the pad fixing region 40 is preferably equal to or larger than the dimension 61x in the width direction WD of the fixing means 61 of the disposable absorbent pad 60, and particularly 1.1 to 1.5 times as large, and the dimension 40y in the front-to-rear direction LD of the pad fixing region 40 is preferably equal to or larger than the dimension measured by experiment or the like to provide a sufficient area for fixing the fixing means 61 of the disposable absorbent pad 60. As an example, when considering the use of many different types of disposable absorbent pads 60 in combination, the dimension 40y in the front-to-rear direction LD of the pad fixing region 40 can be 10 to 20 mm, and the dimension 40x in the width direction WD of the pad fixing region 40 can be 50 to 120 mm.

[0063] The dimension 30x (maximum value, if it varies depending on the position) of the central region 30 in the width direction WD can be set as appropriate, as long as it is equal to or greater than the dimension 40x (maximum value, if it varies depending on the position) of the pad fixing region 40. Generally, the dimension 60x (maximum value, if it varies depending on the position) of the width direction WD of the disposable absorbent pad 60 used in combination is generally approximately the same as or shorter than the dimension 10x (maximum value, if it varies depending on the position) of the width direction WD of the inner body 10. Since the dimension 61x (maximum value, if it varies depending on the position) of the width direction WD of the fixing means 61 of the disposable absorbent pad 60 is equal to or smaller than the dimension 60x (maximum value, if it varies depending on the position) of the width direction WD of the disposable absorbent pad 60, the dimension 30x (maximum value, if it varies depending on the position) of the width direction WD of the central region 30 can be set shorter than the dimension 10x (maximum value, if it varies depending on the position) of the width direction WD of the inner body 10. For example, the dimension 30x (maximum value, if it varies depending on the position) of the width direction WD of the central region 30 can be set to be 0.5 to 0.9 times the dimension 10x (maximum value, if it varies depending on the position) of the width direction WD of the inner body 10. On the other hand, the dimensions of the first region 31 and the second region 32 in the width direction WD are determined by the spacing between the side seal portions 21 in the width direction WD and the dimension 30x of the central region 30 in the width direction WD.

[0064] 6 and 9, the entire third region 33 may be the pad fixing region 40. However, this may result in insufficient fit to the body surface. Therefore, as shown in FIGS. 10 and 11, it is preferable that the pad fixing region 40 is only a part of the third region 33, and that the regions 34, 35 of the third region 33 other than the pad fixing region 40 are elastic regions having a maximum extensibility in the width direction WD greater than the maximum extensibility in the second width direction WD. In this case, poor fit at the end of the inner body 10 in the front-to-rear direction LD may lead to leakage, so it is preferable that the region 35 of the third region 33 adjacent to the edge of the inner body 10 in the front-to-rear direction LD is not the pad fixing region 40 but is an elastic region, as shown in FIGS. 10 and 11. Furthermore, because the waist region W is a region that is tightened relatively tightly, if the pad fixing region 40 is located in the portion of the third region 33 adjacent to the waist region W, there is a risk that the fit will be reduced or the wearing comfort will be worsened due to the large change in elasticity from the waist region W to the lower-waist region U. Therefore, as shown in Figure 10, it is preferable that the pad fixing region 40 is located midway in the front-to-back direction LD of the third region 33, and that the fourth region 34 between the pad fixing region 40 and the waist region W and the fifth region 35 between the pad fixing region 40 and the inner body 10 of the third region 33 are elastic regions each having a maximum extensibility in the width direction WD that is greater than the maximum extensibility in the second width direction WD.

[0065] If only one pad fixing region 40 is provided in the third region 33, the pad fixing region 40 must be elongated in the front-to-back direction LD to allow the user to select the pad fixing position according to the user's body type, preferences, or pad length. However, this may result in a decrease in fit. Therefore, as shown in Figure 11, it is preferable to arrange multiple pad fixing regions 40 at intervals in the front-to-back direction LD at the middle of the third region 33 in the front-to-back direction LD, and to make the fourth region 34 between the pad fixing region 40 and the waist region W, the fifth region 35 between the pad fixing region 40 and the inner body 10, and the sixth region 36 between adjacent pad fixing regions 40 in the front-to-back direction LD elastic regions each having a maximum elongation rate in the width direction WD greater than the maximum elongation rate in the second width direction WD. This allows the pad fixing position to be selected while preventing a decrease in fit in the torso region T.

[0066] If the pad fixing region 40 is only a part of the third region 33, and the regions 34 to 36 other than the pad fixing region 40 of the third region 33 are elastic regions having a maximum elongation rate in the width direction WD greater than the maximum elongation rate in the second width direction WD, from the standpoint of ease of manufacturing, it is preferable that the maximum elongation rate in the width direction WD of the regions 34 to 36 other than the pad fixing region 40 of the third region 33 be the same as the maximum elongation rate in the first width direction WD (the maximum elongation rate in the width direction WD of the first region 31 and the second region 32), but it may be greater or smaller than the maximum elongation rate in the first width direction WD as long as it is greater than the maximum elongation rate in the second width direction WD (for example, 1.1 to 1.3 times).

[0067] The shape of the pad fixing region 40 can be determined as appropriate, and can be a rectangle with a long side along the front-to-back direction LD, a rectangle with a long side along the width direction WD, a square with a side along the front-to-back direction LD and a side along the width direction WD, or a shape in which the width between both side edges changes from one side to the other in the front-to-back direction LD (for example, a trapezoid with upper and lower bases along the width direction WD, a circle, an ellipse, etc.). In particular, as in the examples shown in Figures 10 and 11, when the pad fixing region 40 is located in the middle of the third region 33 in the front-to-back direction LD and both the front and rear of the pad fixing region 40 in the third region 33 are stretchable regions, if the pad fixing region 40 is an elliptical region having its major axis along the width direction WD as shown in Figure 10(b), the change in the shrinkage rate in the width direction WD in the pad fixing region 40 becomes more gradual and continuous, so that the change in appearance and fit from the pad fixing region 40 to the adjacent parts above and below it (i.e., the fourth and fifth regions 34, 35 in the second embodiment described above, and the fourth to sixth regions 34-36 in the third embodiment described above) becomes gradual and preferable.

[0068] In the examples having the aforementioned fourth and fifth regions 34, 35 and the examples having the aforementioned fourth to sixth regions 34-36, the contraction rate (the reciprocal of the maximum elongation rate) in the width direction WD in the natural length state in the lower waist portion U is low in the region consisting of the pad fixing region 40 and the portions P1 located on both sides of it, and is high in other regions (i.e., the aforementioned fourth and fifth regions 34, 35 and the aforementioned fourth to sixth regions 34-36). In this case, in the natural length state before wearing, the dimension in the width direction WD of the region consisting of the pad fixing region 40 and the portions P1 located on both sides of it is larger than that of the other regions, and this excess dimension appears as a bulge that continues in the width direction WD. This appearance may be undesirable, and the bulging portion may provide a poorer fit when worn than the other regions. Therefore, it is preferable to set the maximum extensibility in the width direction WD of the portion P1 of the first region 31 and the second region 32 located on either side of the pad fixing region 40 to 1.1 to 1.3 times the maximum extensibility in the width direction WD of the other portion P2. This makes the dimension in the width direction WD of the region consisting of the pad fixing region 40 and the portions P1 located on both sides thereof closer to that of the other portions, and reduces any excess bulging of this dimension. As a result, not only the appearance in the natural length state but also the fit when worn is good.

[0069] When the dimension 33y in the front-to-back direction LD of the third region 33 (maximum value if it varies depending on the position) is short, there is meaning in providing the pad fixing region 40, but it is less necessary.Therefore, it is preferable to provide the pad fixing region 40 when the dimension 33y in the front-to-back direction LD of the third region 33 is 0.3 to 0.9 times the dimension in the front-to-back direction LD of the torso region T (maximum value if it varies depending on the position), that is, when the dimension 33y in the front-to-back direction LD of the third region 33 is relatively large.

[0070] When regions with different maximum extensibility are aligned in the width direction WD of the torso region T, it is possible to form the torso region T by joining assemblies with different maximum extensibility, but from the viewpoint of ease of manufacture, it is preferable to attach the elastic members 24-26 continuously along the width direction WD to the outer casing 20 and to reduce the maximum extensibility by partially or completely eliminating or reducing the stretchability provided by the elastic members 25, 26 in specific regions other than the waist region W. That is, in the first to third regions 31-33 of the pants-type disposable diaper, it is preferable to attach the elastic members 24-26 continuously in the width direction WD from one side seal portion 21 to the other side seal portion 21 and to partially or completely eliminate or reduce the stretchability provided by the elastic members 25, 26 only in the pad fixing region 40, thereby reducing the maximum extensibility, thereby making the regions other than the pad fixing region 40 an extensible region.

[0071] The technique of eliminating or reducing the stretchability generated by the elastic members 25, 26 in specific regions to reduce the maximum elongation rate has conventionally been used in the region overlapping with the absorbent body 18 and the region where the inner body 10 is fixed to the outer body 20, and is also adopted in the illustrated example. That is, it is preferable to eliminate or reduce the stretchability generated by the elastic members 25, 26 in the region overlapping with the absorbent body 18 and the region where the inner body 10 is fixed to the outer body 20, as well as in the pad fixing region 40, to reduce the maximum elongation rate.

[0072] When elongated elastic members 24-26 are used as the elastic members 24-26 in the torso region T and the elastic members 24-26 are fixed to the inner sheet layer 22 and the outer sheet layer 23 using a hot melt adhesive, there are two main methods for eliminating or reducing stretchability, either of which can be adopted. Specifically, as shown in Figures 9 to 11, the first method involves fixing the elongated elastic members 24-26 continuously in the width direction WD to the inner sheet layer 22 and the outer sheet layer 23, and cutting the elongated elastic members 25, 26 at multiple intervals in the front-to-back direction LD and the width direction WD in a specific region, such as the pad fixing region 40. Reference numeral 70 in the figures indicates the cut portions. In this case, a large number of small cut pieces r1 of the elongated elastic members 25, 26 remain between the inner sheet layer 22 and the outer sheet layer 23 in a state of shrinking to a certain extent.

[0073] In the second method, an independent contractible portion r2 is formed in a portion of the elongated elastic members 25, 26 located in a specific region such as the pad fixing region 40, without being fixed to the inner sheet layer 22 and the outer sheet layer 23 (or may be weakly fixed with a hot melt adhesive HM), and the independent contractible portion r2 is cut at a single location in the middle of the width direction WD, allowing the independent contractible portion r2 to shrink to its natural length or nearly so without being attached to the inner sheet layer 22 and the outer sheet layer 23. The second method has the advantage of having fewer cutting locations than the first method. An example of a pants-type disposable diaper in which the first region 31, the second region 32, and the pad fixing region 40 are formed using the second method is shown in Figures 12 to 14(a). In this example, in the first region 31 and the second region 32, the hot melt adhesive HM bonds the inner sheet layer 22 and the outer sheet layer 23 over the entire length of the elongated elastic members 25, and also fixes the elongated elastic members 25 to the inner sheet layer 22 and the outer sheet layer 23. To strengthen the fixation of the elongated elastic members 25, additional hot melt adhesive HM may be applied to both ends of the elongated elastic members 25 as shown in Fig. 13, or, although not shown, only both ends of the elongated elastic members 25 may be fixed to the inner sheet layer 22 and the outer sheet layer 23 with the hot melt adhesive. The pad fixing region 40 also has an inner sheet layer 22 and an outer sheet layer 23 that are continuous from the first region 31 and the second region 32 but are not joined to each other, and an independent contracted portion r2 that remains between the inner sheet layer 22 and the outer sheet layer 23 and is formed by the elongated elastic members 25 continuing from the first region 31 and the second region 32 contracting without accompanying the inner sheet layer 22 and the outer sheet layer 23. The pad fixing region 40 also has a plurality of cut portions 70 that cut at least one of the inner sheet layer 22 and the outer sheet layer 23 and are formed so as to intersect with a plurality of imaginary straight lines 71 that connect the elongated elastic members 25 of the first region 31 and the elongated elastic members 25 of the second region 32 along the width direction WD, and only one of these cut portions 70 is provided on each imaginary straight line 71. As a result, the maximum elongation rate of the pad fixing region 40 is approximately 100%. The position of the cut portion 70 in the width direction WD can be changed as appropriate, for example, to the center of the pad fixing region 40 in the width direction WD or to the side edge of the pad fixing region 40.In the former case, the independent shrinkable portions r2 remain on both sides in the width direction, and the independent shrinkable portions r2 remain only on the side opposite to the cut portion.

[0074] As a method for cutting the elongated elastic members 25, 26, a method in which the elongated elastic members 25, 26 are sandwiched between the inner sheet layer 22 and the outer sheet layer 23 and then pressurized with heat (ultrasonic welding, heat embossing, etc.) at the cutting section 70, or a method in which the elongated elastic members 25, 26 are sandwiched between the inner sheet layer 22 and the outer sheet layer 23 and then cut the elongated elastic members 25, 26 and at least one of the inner sheet layer 22 and the outer sheet layer 23 with a cutting blade at the cutting section 70, can be used. In the former case, melt marks are formed at the cut section 70 in at least one of the inner sheet layer 22 and the outer sheet layer 23, and in the latter case, slits are formed at the cut section 70 in at least one of the inner sheet layer 22 and the outer sheet layer 23.

[0075] However, when forming the pad fixing region 40 using the second method using a cutting blade, if each cutting portion 70 is positioned in a straight line along the front-to-back direction LD, as in the illustrated example, there is a risk that the pad fixing region 40 will tear along the cutting portion 70 like a perforation.Therefore, as shown in Figure 13, it is preferable that of a pair of virtual straight lines 71 adjacent to each other in the front-to-back direction LD, the cutting portion 70 that intersects with one virtual straight line 71 is positioned at a different position in the width direction WD than the cutting portion 70 that intersects with the other virtual straight line 71, thereby reducing the risk of the pad fixing region 40 tearing.

[0076] 14(a) and 14(b), the pad fixing region 40 may have imaginary straight lines 71 that intersect with the cut portions 70 and imaginary straight lines 71 that do not intersect with the cut portions 70 (thinning out the cut portions 70), and the pad fixing region 40 may have independent contraction portions r2 at both ends of the imaginary straight lines 71 that intersect with the cut portions 70, and may have elongated elastic members 25 that extend from the first region 31 through the pad fixing region 40 to the second region 32 along the imaginary straight lines 71 that do not intersect with the cut portions 70. In this case, the elastic members 25 remain in the pad fixing region 40 along the imaginary straight lines 71 that do not intersect with the cut portions 70, and therefore the maximum extensibility of the elastic members 25 in the width direction WD must be equal to the maximum extensibility in the second width direction W. To this extent, the number of elongated elastic members 25 extending from the first region 31 through the pad fixing region 40 to the second region 32 can be determined as appropriate, but as an example, it can be 1 to 2, and particularly 1.

[0077] On the other hand, even if the pad fixing region 40 does not have the aforementioned cut portion 70, it is preferable that the strength of the pad fixing region 40 is high. Therefore, as shown in the example of FIG. 13, the pad fixing region 40 preferably has a joint portion 80 where the inner sheet layer 22 and the outer sheet layer 23 are joined at a position where the elastic members 24-26 are not present. This joint portion 80 can be formed by welding the inner sheet layer 22 and the outer sheet layer 23 using a hot melt adhesive or by welding means such as ultrasonic welding or heat sealing. In particular, it is preferable to use a welding means such as ultrasonic welding or heat sealing to cut the elastic members 24-26 and weld the inner sheet layer 22 and the outer sheet layer 23 at the cut positions while cutting the elastic members 24-26. In this case, the joint portion 80 is formed by welding at the cut portion 70.

[0078] When an elastic sheet such as an elastic film is used as the elastic member provided between the inner sheet layer 22 and the outer sheet layer 23, although not shown, the elastic sheet is attached continuously in the width direction WD from one side seal portion 21 to the other side seal portion 21 at least in the third region 33 and the portions located on both sides thereof, and the inner sheet layer 22 and the outer sheet layer 23 are indirectly joined via the elastic sheet at a number of spaced-apart joints, and by increasing the number of joints per unit area in specific regions such as the pad fixing region 40, the maximum elongation rate in the width direction WD in specific regions such as the pad fixing region 40 can be reduced while the portions other than the pad fixing region 40 can be made into stretchable regions. Furthermore, when the inner sheet layer 22 and the outer sheet layer 23 are directly joined via the elastic sheet at a large number of spaced-apart joints, the joints can be arranged so that the elastic sheet does not have a linearly continuous portion along the width direction WD in a specific region such as the pad fixing region 40, thereby reducing the maximum extensibility in the width direction WD in the specific region such as the pad fixing region 40, while making the region other than the pad fixing region 40 a stretchable region. These structures have the advantage that the strength of the pad fixing region 40 is less likely to decrease because no cut portions 70 are formed in the pad fixing region 40.

[0079] (disposable absorbent pads) The pants-type disposable diaper of this example is not limited to the disposable absorbent pad 60. Therefore, the pants-type disposable diaper of this example can be used without the disposable absorbent pad 60. Furthermore, the pants-type disposable diaper of this example can use any known disposable absorbent pad 60 without any particular limitations, and can also use one that does not have the fixing means 61. The user can decide whether to use a disposable absorbent pad 60, what type of disposable absorbent pad 60 to use, and whether to use a pad fixing region 40. However, since the pants-type disposable diaper of this example is characterized by having the pad fixing region 40, a disposable absorbent pad 60 having fixing means 61 that can be fixed to the pad fixing region 40 of the pants-type disposable diaper of this example can be preferably used.

[0080] 15 and 16 show an example of a disposable absorbent pad 60 suitable for the pants-type disposable diaper of this embodiment. This disposable absorbent pad 60 comprises an absorbent body 18, a liquid-permeable top sheet disposed on the front side of the absorbent body 18, a liquid-impermeable sheet disposed on the back side of the absorbent body 18, and fastening means 61 provided on the back side for fastening to an outer garment such as a disposable diaper or underwear. Any known fastening means 61 can be used as the fastening means 61, such as a hook material of a mechanical fastener or an adhesive. The fastening means 61 is preferably provided only in the middle of the disposable absorbent pad 60 in the width direction WD, but may also be provided over almost the entire width direction WD. Alternatively, the fastening means 61 may be provided over the entire front-to-rear direction LD of the disposable absorbent pad 60 as shown in FIG. 16, or may be provided at multiple locations spaced apart in the front-to-rear direction LD. In the latter case, the fastening means 61 are preferably provided at least at the front and rear end portions of the disposable absorbent pad 60 as shown in FIG. 15, but fastening means 61 may also be provided in the middle of the front-to-rear direction LD.

[0081] The total length 60y of the disposable absorbent pad 60 may be shorter than the total length 10y of the inner body 10, but is preferably longer than the total length 10y of the inner body 10. Even in the former case, the fixing position of the disposable absorbent pad 60 can be shifted to either the front or the back, and the fixing means 61 of the disposable absorbent pad 60 can be fixed to either the front or the back pad fixing region 40. In the latter case, it is particularly preferable that the fixing means 61 at the front end and the rear end of the disposable absorbent pad 60 can be fixed to the pad fixing region 40 of the pants-type disposable diaper, respectively. If the dimension 60x of the disposable absorbent pad 60 in the width direction WD is wider than the dimension 10x of the width direction WD of the inner body 10 of the pants-type disposable diaper, there is an advantage that the disposable absorbent pad can be used without soiling the three-dimensional gathers BS of the pants-type disposable diaper. The dimension 60x of the disposable absorbent pad 60 in the width direction WD is narrower than the dimension 10x of the width direction WD of the inner body 10 of the pants-type disposable diaper, and the disposable absorbent pad 60 can be placed between the three-dimensional gathers BS of the pants-type disposable diaper, allowing the three-dimensional gathers BS of the pants-type disposable diaper to function effectively.

[0082] <Explanation of terms used in the specification> When used in this specification, the following terms have the following meanings unless otherwise specified in the specification. "Front-rear direction" refers to the direction indicated by the symbol LD in the drawing (longitudinal direction), and "width direction" refers to the direction indicated by the symbol WD in the drawing (left-right direction), with the front-rear direction and width direction being perpendicular to each other. "Front" means the side closest to the wearer's skin, and "reverse" means the side away from the wearer's skin. "Front" means the side closest to the wearer's skin, and "Back" means the side away from the wearer's skin. "Expanded state" means a state in which the material is stretched to its elastic limit (in other words, contracted (including any contraction, such as contraction due to an elastic member) or deployed flat without slack). "Elongation rate" refers to the value when the natural length is 100%. For example, an elongation rate of 200% is equivalent to an elongation ratio of 2 times. "Maximum elongation rate" means the elongation rate in the unfolded state. "Basis weight" is measured as follows: After pre-drying the sample or test piece, leave it in a test room or device under standard conditions (test location: temperature 23±1°C, relative humidity 50±2%) until it reaches a constant weight. Pre-drying refers to bringing the sample or test piece to a constant weight in an environment at a temperature of 100°C. Note that pre-drying is not necessary for fibers with an official moisture regain of 0.0%. From the test piece that has reached a constant weight, use a sample collection template (100mm x 100mm) to cut out a sample measuring 100mm x 100mm. Measure the weight of the sample and multiply it by 100 to calculate the weight per square meter, which is the basis weight. The "thickness" of thick materials such as absorbers is measured using a thickness measuring device (Peacock, Dial Thickness Gauge, Model H (measuring range 0-10 mm, measuring area 10 mm diameter circular terminal, measuring force approximately 1.7 N, pressure approximately 21.7 KPa)) manufactured by Ozaki Manufacturing Co., Ltd., with the sample and thickness measuring device positioned horizontally. The "thickness" of thin sheets such as nonwoven fabrics was measured using an automatic thickness measuring device (KES-G5 handy compression measurement program) with a load of 0.098 N / cm 2 , and pressure area: 2cm 2 Automatic measurement is performed under the following conditions. "Water absorption" is measured according to JIS K7223-1996 "Test method for water absorption of superabsorbent polymers." "Water absorption rate" is the "time to the end point" when 2g of superabsorbent polymer and 50g of physiological saline are used and the test is carried out in accordance with JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymers." "Elongation of nonwoven fabrics" is measured by applying a constant load to the sample at a constant speed using a constant-speed extension tensile testing machine with the accuracy specified in JIS B 7721 based on ISO 9073-3, and conducting a "tensile strength and elongation" test. Unless otherwise specified, the dimensions and relative positions of each part refer to the dimensions and relative positions in the unfolded state, not in the natural length state. If no environmental conditions for a test or measurement are specified, the test or measurement shall be carried out in a test room or device under standard conditions (temperature of 23±1°C, relative humidity of 50±2%). [Industrial Applicability]

[0083] The present invention can be applied to absorbent articles in general, such as pants-type disposable diapers, as in the above example. [Explanation of symbols]

[0084] 10...inner body, 11...top sheet, 12...liquid-impermeable sheet, 13...constricted portion, 14...packaging sheet, 15...gathered sheet, 16...gathered elastic member, 18...absorbent body, 20...outer body, 20C...folded-back portion, 21...side seal portion, 22...inner sheet layer, 23...outer sheet layer, 24-26...elastic member, 24...waist elastic member, 25...lower waist elastic member, 26...back curved elastic member, 26...curved elastic member, 28...ventral curved elastic member, 29...leg circumference line, 30...center Region, 31...first region, 32...second region, 33...third region, 34...fourth region, 35...fifth region, 36...sixth region, 40...pad fixing region, 50...cover sheet, 50...cover sheet, 60...disposable absorbent pad, 61...fixing means, 70...cutting portion, 71...imaginary straight line, 80...joint, B...back body, BS...three-dimensional gathers, F...front body, L...middle region, LD...front and back direction, T...torso region, U...lower waist portion, W...waist portion, WD...width direction, r1...cutting piece, r2...independent contraction portion.

Claims

1. An integrated outer body extending from the front body to the back body, or an outer body provided separately on the front body and the back body, An inner body including an absorbent body fixed to the outer body so as to extend from the front body to the back body; side seal portions at which both side portions of the exterior body of the front body and both side portions of the exterior body of the back body are joined together; It has a waist opening and a pair of left and right leg openings, the exterior body has a trunk region defined as a region between one of the side seal portions and the other of the side seal portions, The torso region comprises a waist portion extending along an upper edge from one of the side seal portions to the other of the side seal portions, and a lower waist portion extending adjacent to and below the waist portion from one of the side seal portions to the other of the side seal portions, The waist lower portion comprises a central region located at the center in the width direction, a first region defined as a region between one of the side seal portions and the central region, and a second region defined as a region between the other of the side seal portions and the central region, The front and rear edges of the interior body are located within the lower waist portion and spaced downward from the lower edge of the waist portion, the waist portion, the first region, and the second region are elastic regions having a first maximum widthwise elongation rate of 160 to 320%, The stretchable region includes an inner sheet layer, an outer sheet layer, and an elastic member provided between the inner sheet layer and the outer sheet layer, and is a region that elastically stretches between a natural length state in which the elastic member contracts in the width direction to form pleats on the inner surface, and an expanded state in which the elastic member stretches to the first maximum stretch rate in the width direction to form no pleats, a pad fixing region having a second maximum widthwise elongation rate of less than 110% in a third region between the waist portion and the inner body in the central region; A pants-type disposable diaper characterized by:

2. the pad fixing region is disposed midway between the third region in the front-rear direction, Of the third region, a fourth region between the pad fixing region and the waist portion and a fifth region between the pad fixing region and the inner body are stretchable regions each having a maximum widthwise elongation rate greater than the second maximum widthwise elongation rate.

2. The pants-type disposable diaper according to claim 1.

3. a plurality of the pad fixing regions are arranged at intervals in the front-rear direction at a center of the third region in the front-rear direction, Of the third region, a fourth region between the pad fixing region and the waist portion, a fifth region between the pad fixing region and the inner body, and a sixth region between adjacent pad fixing regions in the front-rear direction are stretchable regions each having a maximum widthwise elongation rate greater than the second maximum widthwise elongation rate.

2. The pants-type disposable diaper according to claim 1.

4. the maximum widthwise elongation rate of the portions of the first region and the second region located on the sides of the pad fixing region is 1 to 1.5 times the maximum widthwise elongation rate of the other portions; 4. The pants-type disposable diaper according to claim 2 or 3.

5. The pad fixing region is an elliptical region having a major axis along the width direction.

4. The pants-type disposable diaper according to claim 2 or 3.

6. The width direction dimension of the central region is 0.3 to 1 times the width direction dimension of the inner body, The width direction dimension of the pad fixing region is 0.3 to 1 times the width direction dimension of the central region.

3. The pants-type disposable diaper according to claim 1 or 2.

7. The elastic members are a plurality of elongated elastic members attached at intervals in the front-rear direction and extending along the width direction, In the first region and the second region, the inner sheet layer and the outer sheet layer are joined together by a hot melt adhesive at least at both end portions of the elongated elastic members, and the elongated elastic members are fixed to the inner sheet layer and the outer sheet layer, the pad fixing region has an inner sheet layer and an outer sheet layer continuing from the first region and the second region, and an independent contracted portion left between the inner sheet layer and the outer sheet layer, where the elongated elastic member continuing from the first region and the second region has contracted without being accompanied by the inner sheet layer and the outer sheet layer, the pad fixing region has a plurality of cutting portions for cutting at least one of the inner sheet layer and the outer sheet layer, the cutting portions being formed so as to intersect with a plurality of imaginary straight lines connecting the elongated elastic members in the first region and the elongated elastic members in the second region along the width direction, The cutting portion is provided at only one location on each virtual straight line, the cut portion intersecting one of a pair of imaginary straight lines adjacent to each other in the front-rear direction is positioned at a different widthwise position from the cut portion intersecting the other imaginary straight line; 3. The pants-type disposable diaper according to claim 1 or 2.

8. The elastic members are a plurality of elongated elastic members attached at intervals in the front-rear direction and extending along the width direction, In the first region and the second region, the inner sheet layer and the outer sheet layer are joined together by a hot melt adhesive at least at both end portions of the elongated elastic members, and the elongated elastic members are fixed to the inner sheet layer and the outer sheet layer, the pad fixing region has an inner sheet layer and an outer sheet layer continuing from the first region and the second region, and an independent contracted portion left between the inner sheet layer and the outer sheet layer, where the elongated elastic member continuing from the first region and the second region has contracted without being accompanied by the inner sheet layer and the outer sheet layer, the pad fixing region has a plurality of cutting portions for cutting at least one of the inner sheet layer and the outer sheet layer, the cutting portions being formed so as to intersect with a plurality of imaginary straight lines connecting the elongated elastic members in the first region and the elongated elastic members in the second region along the width direction, the pad fixing region has an imaginary straight line that intersects with the cut portion and an imaginary straight line that does not intersect with the cut portion, the pad fixing region has the independent contraction portions at both ends of an imaginary straight line that intersects with the cut portion, and has an elongated elastic member that extends from the first region through the pad fixing region to the second region along an imaginary straight line that does not intersect with the cut portion.

3. The pants-type disposable diaper according to claim 1 or 2.

9. The pad fixing region has a joining portion where the inner sheet layer and the outer sheet layer are joined at a position where the elastic member is not present.

3. The pants-type disposable diaper according to claim 1 or 2.

10. The front-to-back dimension of the third region is 0.3 to 0.9 times the front-to-back dimension of the torso region.

3. The pants-type disposable diaper according to claim 1 or 2.

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