Pants-type disposable wear

Abstract

To reduce deterioration in a touch of single plane surface gathers in a side non-stretchable region.SOLUTION: A front end and a rear end of a side flap 60 is a side non-stretchable region 70 having a fixed part 67 in which a surface part 61 is fixed to a back surface part 62. The fixed part 67 is separated from a side edge of the side non-stretchable region 70 to a center side in a width direction WD, and a part between the side edge of the side non-stretchable region 70 and the fixed part 67 includes a hollow part 70h over the entire width direction WD. The side non-stretchable region 70 includes a non-fixed free part 71 extending from the side edge to the center side in the width direction WD. As a result of the back surface part 62 between the free part 71 and the fixed part 67 in the side non-stretchable region 70 being contracted in the width direction WD together with a waistline stretchable region in the state of being worn, the surface part 61 of the free part 71 floats and bulges while the back surface part 62 is raised, and part of the surface part covers at least a side part of the surface of the fixed part 67.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a pants-type disposable wearing article having flat gathers on both sides of the width of an inner body. [Background technology]

[0002] Pant-type disposable wearing articles such as pants-type disposable diapers and pants-type sanitary napkins generally comprise an outer body having side seals formed by joining a waist portion of a front body, a waist portion of a back body, and both side portions thereof; an inner body joined to the middle of the outer body in the width direction so as to extend from the waist portion of the front body through the crotch portion to the waist portion of the back body; a waist opening formed by the front edge of the front body and the rear edge of the back body; and leg openings provided on both sides of the inner body.

[0003] The waist portion of the outer garment is provided with an elastic member, which provides stretchability in the width direction, allowing the waist region to fit well to the body surface of the wearer.

[0004] Furthermore, in pants-type disposable wearable articles, it is common for side gathers to be provided on both widthwise sides of the inner body to fit the inner thighs of the wearer, in order to improve the fit around the legs and prevent so-called side leakage (see, for example, Patent Documents 1 to 3).

[0005] Various structures of side gathers have been proposed in the past. For example, gathers that rise from the sides of the inner body to the front are generally called three-dimensional gathers and are excellent at preventing leakage. In contrast, gathers formed by side flaps that extend to the sides of the absorbent body (without being folded back to the front) are generally called flat gathers and are often used in combination with three-dimensional gathers.

[0006] Furthermore, particularly for simple, low-cost products, products have been proposed that have flat gathers but no three-dimensional gathers (see, for example, Patent Documents 1 to 4). In particular, the side flaps described in Patent Document 4 have a side nonwoven fabric having a surface portion extending from the side edge of the absorbent body to the side edge of the side flap and a back portion folded back at the side edge of the surface portion to extend to the side edge of the absorbent body, and an elongated gathered elastic member provided in the front-to-back direction between the surface portion and the back portion, the front and back ends of the side flaps do not contract in the front-to-back direction together with the gathered elastic member and form side non-stretchable regions having sheet joints where the surface portion and the back portion are joined, and the portion between the front and back non-stretchable side regions of the side flaps has gathered elastic members fixed to the surface and back portion, contracts in the front-to-back direction together with the gathered elastic member and forms flat gathers that can stretch in the front-to-back direction together with the gathered elastic member.

[0007] If the flat gathers extend to the area where they overlap with the stretchable region of the waistband of the outer garment, contracted portions will be formed in both the front-to-back and width directions, which is undesirable as it will deteriorate the fit and appearance. Therefore, as mentioned above, it is desirable to provide non-stretchable side regions at the front and rear ends of the side flaps. Here, the sheet joints in the non-stretchable side regions are provided for the purpose of preventing the entire non-stretchable side region from becoming hollow and cylindrical, which would cause irregular deformation and deteriorate the fit.

[0008] However, in the case of the product described in Patent Document 4, the hard sheet joints in the non-stretchable side regions are exposed to the surface, which may cause a poor feel against the skin. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 5303689 [Patent Document 2] Patent No. 5400982 [Patent Document 3] Patent No. 6986097 [Patent Document 4] Japanese Patent Application Laid-Open No. 2016-083122 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, a main object of the present invention is to reduce the deterioration of the feel against the skin in the non-elastic side regions of the single plane gathers. [Means for solving the problem]

[0011] The following pants-type disposable wearing article has solved the above problems. <First aspect> an exterior body having a front waistband, a back waistband, and side seals formed by joining both side portions thereof; An inner body joined to the middle of the outer body in the width direction so as to extend from the waist portion of the front body through the crotch portion to the waist portion of the back body; a waist opening formed by the front edge of the front body and the rear edge of the back body; leg openings provided on both sides of the interior body, the inner body has an absorbent body that continues from a position in front of the crotch region to a position in back of the crotch region, The waist portion of the front body and the waist portion of the back body have waist stretchable regions provided on at least both sides in the width direction, The waist elastic region incorporates a waist elastic member, contracts in the width direction together with the waist elastic member, and is extensible in the width direction together with the waist elastic member; A pair of side flaps extend from the side edges of the absorbent body to both sides in the width direction on both sides of the inner body, extending in the front-rear direction from an area overlapping the waist-surrounding elastic region of the front body to an area overlapping the waist-surrounding elastic region of the back body, The side flaps each include a side nonwoven fabric extending from the front surface of the side flap through the side edge of the side flap to the back surface of the side flap, and an elongated gathered elastic member provided along the front-to-rear direction between the front surface and back surface of the side nonwoven fabric, The front surface portion and the back surface portion extend over the entire front and rear of the side flap, The front end and the rear end of the side flap do not contract in the front-to-rear direction together with the gathered elastic member, and the front surface portion is fixed directly or indirectly to the back surface portion, forming a side non-stretchable region. The portions of the side flaps between the front and rear side non-elastic regions are flat gathered regions to which the gathered elastic members are fixed, and which contract in the front-to-rear direction together with the gathered elastic members, and which are stretchable in the front-to-rear direction together with the gathered elastic members; Does not have three-dimensional gathers that rise up on the front side A pants-type disposable wearable article; the fixed portion is spaced a first distance from the side edge of the side non-elastic region toward the center in the width direction, A portion between the side edge of the side non-elastic region and the fixed portion has a hollow portion extending over the entire width direction thereof, the side non-stretchable region has a free portion that is not fixed to the exterior body and extends from a side edge of the side non-stretchable region to a position a second distance toward the center in the width direction, the second distance is greater than half the width of the fixing portion and less than half the first distance; the back surface portion located between the free portion and the fixed portion is joined to the waist-surrounding elastic region of the exterior body, contracts in the width direction together with the waist-surrounding elastic member, and is extensible in the width direction together with the waist-surrounding elastic member; The maximum stretch in the width direction of the waist elastic region is 200 to 320%. A pants-type disposable wearing article characterized by:

[0012] (Action and effect) In this pants-type disposable wearable article, the maximum stretch in the width direction of the waist elastic region is E max Then, the waist stretch area is 0.5~0.7E max When the garment is in a state similar to that when worn, the back surface of the non-elastic side region between the free portion and the fixed portion shrinks in the width direction together with the elastic waist region, and this shrinkage causes the back surface of the free portion to rise while the surface portion rises and bulges, so that the portion of the surface portion adjacent to the fixed portion (the non-fixed portion of the side nonwoven fabric) covers at least the side surface of the fixed portion. Moreover, this bulged portion collapses and widens when worn, covering a wider area of ​​the fixed portion. As a result, the hard surface of the fixed portion in the non-elastic side region is less likely to come into contact with the skin, reducing deterioration in feel.

[0013] <Second aspect> the first distance is 15 to 20 mm; the second distance is equal to or less than one-third of the first distance; The width of the fixing portion is 3 mm or more. A pants-type disposable wearing article according to a first embodiment.

[0014] (Action and effect) The dimensions of each part can be determined as appropriate, but it is particularly preferable that they are within the range of this embodiment.

[0015] <Third aspect> When the first distance is w1, the second distance is w2, and the dimension of the fixing portion in the width direction is w3, 0.3(w1+w2) / 2≧w3 is satisfied. A pants-type disposable wearing article according to the first or second aspect.

[0016] (Action and effect) The dimensions of each part can be determined as appropriate, but if they are within the range of this embodiment, the bulge of the surface portion becomes larger, making it easier to cover a wide area of ​​the fixing part, which is preferable.

[0017] <Fourth aspect> The second distance is greater than the width dimension of the fixing portion. Any one of 1 to 3 One aspect A pants-type disposable wearable item.

[0018] (Action and effect) The dimensions of each part can be determined as appropriate, but it is preferable that they are within the range of this embodiment, since the surface part will be more likely to swell.

[0019] <Fifth aspect> The back surface portion located at the fixing portion is joined to the waist-surrounding elastic region of the exterior body, contracts in the width direction together with the waist-surrounding elastic member, and is also stretchable in the width direction together with the waist-surrounding elastic member. Any one of 1 to 4 One aspect A pants-type disposable wearable item.

[0020] (Action and effect) In this embodiment, the waist stretch area is 0.5 to 0.7E max When the garment is in a state of approximately the same degree of shrinkage as when it is worn, the fixing part shrinks in the width direction together with the waist-surrounding elastic region, and the coverage ratio of the fixing part by the surface part increases relatively. Therefore, the surface of the fixing part is less likely to come into contact with the skin.

[0021] <Sixth aspect> the fastening portion is laterally spaced a third distance from a side edge of the absorbent body; the surface portion has an end portion that protrudes from the fixing portion toward the center in the width direction by a fourth distance that is shorter than the third distance and is not joined to an adjacent member on the back side, the fourth distance is greater than half the width of the fixing portion, a back surface portion located between the fixing portion and the side edge of the absorbent body is joined to the waist-surrounding elastic region of the exterior body, contracts in the width direction together with the waist-surrounding elastic member, and is extensible in the width direction together with the waist-surrounding elastic member; Any one of 1 to 5 One aspect A pants-type disposable wearable item.

[0022] (Action and effect) According to this aspect, the end of the surface portion protruding from the fixing part toward the center in the width direction is raised along the shrinkage wrinkles of the member located on the back side, and the part of this raised portion adjacent to the fixing part (the unfixed part of the side nonwoven fabric) covers at least the end of the surface of the fixing part toward the center in the width direction. As a result, the surface of the fixing part is even less likely to come into contact with the skin. [Effects of the Invention]

[0023] As described above, the present invention provides advantages such as reducing deterioration in the feel of the fabric in the non-elastic side regions of the single plane gathers. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a plan view showing the surface of a pants-type disposable diaper in an unfolded state. FIG. [Figure 2] 1 is a plan view showing the underside of a pants-type disposable diaper in an unfolded state. FIG. [Figure 3] 3 is a cross-sectional view of FIG. 1 taken along line 3-3. [Figure 4] 4 is a cross-sectional view taken along line 4-4 of FIG. 1. [Figure 5] 5 is a cross-sectional view taken along line 5-5 of FIG. 1. [Figure 6] FIG. 2 is a plan view showing the surface of the inner body. [Figure 7] 1 is a perspective view of a pants-type disposable diaper, seen from the front and diagonally below. FIG. [Figure 8] FIG. 2 is a cross-sectional view of a main part showing the attached state. [Figure 9] FIG. 2 is a cross-sectional view of an absorbent element. [Figure 10] FIG. [Figure 11] FIG. 11 is a plan view of the main part of FIG. [Figure 12] FIG. 2 is an enlarged cross-sectional view showing a main part of the non-stretchable side region in the unfolded state. [Figure 13]FIG. 10 is an enlarged cross-sectional view showing a main part of the non-elastic side region in a state where it has contracted to 70%. [Figure 14] FIG. 10 is a front view schematically showing the inclination of each part of the side flap. DETAILED DESCRIPTION OF THE INVENTION

[0025] The above-mentioned pants-type disposable wearing article will be described in detail below with reference to an example of a pants-type disposable diaper shown in the accompanying drawings. Note that adjacent components in the thickness direction may be fixed or joined as needed, in addition to the fixed or joined portions described below, in the same manner as known diapers. The dotted areas in the cross-sectional view indicate adhesives such as hot-melt adhesives used as the fixing or joining means. Hot-melt adhesives can be applied by known methods, such as slot coating, continuous or dotted bead coating, spiral, Z-shaped, or wavy (regular or irregular) spray coating, or pattern coating (transfer of hot-melt adhesive using a relief printing method). Alternatively or in addition to this, hot-melt adhesive can be applied to the outer surface of the elastic member to fix the elastic member to an adjacent member. Hot-melt adhesives include, for example, EVA-based, adhesive rubber-based (elastomer-based), polyolefin-based, and polyester / polyamide-based types, but no particular limitation is imposed on them. Material welding methods such as heat sealing and ultrasonic sealing can also be used to fix or join the components. In areas where liquid permeability in the thickness direction is required, adjacent components in the thickness direction are fixed or joined in an intermittent pattern. For example, when such intermittent fixing or joining is performed using a hot melt adhesive, intermittent pattern application such as a spiral, Z-shape, or wavy pattern can be suitably used. When applying to an area greater than the application width of a single nozzle, intermittent pattern application such as a spiral, Z-shape, or wavy pattern can be performed with or without gaps in the width direction. Material welding methods such as heat sealing and ultrasonic sealing can also be used to join the components.

[0026] 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 can be hydrophilic fibers (including fibers made hydrophilic by a hydrophilizing agent), hydrophobic fibers, or water-repellent fibers (including fibers made water-repellent by a water-repellent agent). Furthermore, nonwoven fabrics are generally classified 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-bond nonwoven fabrics, laminated nonwoven fabrics (including SMS nonwoven fabrics and SMMS nonwoven fabrics in which a meltblown layer is sandwiched between spunbond layers), etc. depending on the fiber length, sheet formation method, fiber bonding method, and laminated structure, and any of these nonwoven fabrics can be used.

[0027] 1 to 7 show an example of a pants-type disposable diaper. This pants-type disposable diaper 100 includes a rectangular front outer body 12F constituting a front waist-surrounding portion, a rectangular rear outer body 12B constituting a rear waist-surrounding portion, and an inner body 200 joined to the middle of the outer bodies 12F, 12B in the width direction WD so as to extend from the front outer body 12F through the crotch region M to the rear outer body 12B. Side seals 12A are formed by joining both sides of the front outer body 12F to both sides of the rear outer body 12B, whereby an opening formed by the front and rear edges of the outer bodies 12F, 12B serves as a waist opening WO through which the wearer's waist is passed, and portions on both sides of the inner body 200 in the width direction WD that are surrounded by the lower edges of the outer bodies 12F, 12B and the side edges of the inner body 200 serve as leg openings LO through which the legs are passed. The inner body 200 is a part that absorbs and retains excrement such as urine, and the outer bodies 12F, 12B are parts that support the inner body 200 against the wearer's body. Furthermore, the symbol Y indicates the overall length of the diaper in the unfolded state (the length in the front-to-back direction from the edge of the waist opening WO of the front body F to the edge of the waist opening WO of the back body B), and the symbol X indicates the overall width of the diaper in the unfolded state.

[0028] The pants-type disposable diaper 100 has a waist region T defined as the front-to-back range having the side seals 12A (the front-to-back range from the waist opening WO to the top ends of the leg openings LO), and an intermediate region L defined as the front-to-back range of the portion forming the leg openings LO (between the front-to-back region having the side seals 12A of the front body F and the front-to-back region having the side seals 12A of the back body B). The portions of the front exterior body 12F and the rear exterior body 12B located in the waist region T, i.e., the front waist portion and the rear waist portion, can be conceptually divided into a "waist portion" W that forms the edge of the waist opening, and a "lower waist portion" U that is the portion below this. Typically, when the front and rear waist regions have a boundary where the stretch stress in the width direction WD changes (e.g., where the thickness or elongation rate of the elastic member changes), the waist region W is the portion closer to the waist opening WO than the boundary closest to the waist opening WO. When no such boundary exists, the waist region W is the portion extending further toward the waist opening WO than the absorbent body 56 or inner body 200. Their front-to-rear lengths vary depending on the product size and can be determined as appropriate. For example, the waist region W may be 15 to 40 mm, and the lower waist region U may be 65 to 120 mm. Meanwhile, both side edges of the middle region L are constricted in a U-shape or curved shape to fit around the wearer's legs, and these are the areas into which the wearer's legs are inserted. As a result, the pants-type disposable diaper in its unfolded state has a generally hourglass shape overall.

[0029] (exterior body) As shown in the figure, the exterior bodies 12F, 12B are composed of a rectangular front exterior body 12F that constitutes at least the waistline of the front body F, and a rectangular back exterior body 12B that constitutes at least the waistline of the back body B. The front exterior body 12F and the rear exterior body 12B may not be continuous at the crotch side and may be spaced apart in the front-to-back direction LD (a two-piece exterior body type), or may be continuous from the front body F through the crotch region M to the back body B (an integrated exterior body type), although this is not shown. In the two-piece exterior body type, the separation distance 12d in the front-to-back direction can be, for example, approximately 40 to 60% of the total length Y. In the figure, the lower edges of the front exterior body 12F and the rear exterior body 12B are linear and extend along the width direction WD. However, the lower edge of at least one of the front exterior body 12F and the rear exterior body 12B may be curved to fit around the legs.

[0030] In a pants-type disposable diaper with a two-piece exterior, the inner body 200 is exposed between the front exterior body 12F and the rear exterior body 12B, and therefore, to prevent the liquid-impermeable film 11 from being exposed on the back surface of the inner body 200, it is preferable to provide a cover nonwoven fabric layer 13 on the back surface of the inner body 200, extending from between the front exterior body 12F and the inner body 200 to between the rear exterior body 12B and the inner body 200. The inner and outer surfaces of the cover nonwoven fabric layer 13 can be bonded to their respective opposing surfaces via a hot melt adhesive. The nonwoven fabric used for the cover nonwoven fabric layer 13 can be selected appropriately from, for example, the same material as that of the exterior bodies 12F and 12B.

[0031] The front exterior body 12F and the rear exterior body 12B have a front waist portion and a rear waist portion that form the waist region T. In the example shown in Figures 1 and 2, the front-to-rear dimension of the rear exterior body 12B is longer than that of the front exterior body 12F, the front exterior body 12F does not have a portion corresponding to the middle region L, and the rear exterior body 12B has a buttocks covering portion 14 that extends from the waist region T toward the middle region L; however, the front exterior body 12F and the rear exterior body 12B may have the same dimension in the front-to-rear direction LD, and the front exterior body 12F and the rear exterior body 12B may not have a portion corresponding to the middle region L.

[0032] 3 to 5, the exterior bodies 12F, 12B are formed by joining an outer sheet layer 12S and an inner sheet layer 12H adjacent to the outer and inner sides of the elastic members 15 to 17, which will be described later, by a joining means such as a hot melt adhesive or welding. As shown in Fig. 5, the outer sheet layer 12S and the inner sheet layer 12H are formed by folding a single sheet material so that the fold is located on the waist opening side, or, although not shown, they can also be formed by bonding two sheets of sheet material together.

[0033] The sheet material used for the outer sheet layer 12S and the inner sheet layer 12H is not particularly limited, but nonwoven fabric is preferred. When nonwoven fabric is used, the basis weight per sheet is 10 to 30 g / m 2 It is preferable to set it to about this level.

[0034] To improve the fit around the waist of the wearer, the outer coverings 12F, 12B have elastic members 15-17 attached between the outer sheet layer 12S and the inner sheet layer 12H at a predetermined stretch rate, forming a waist-surrounding stretchable region that stretches elastically in the width direction WD together with the elastic members 15-17. When in its natural length, the waist-surrounding stretchable region contracts as the elastic members 15-17 contract, forming wrinkles or folds. When stretched in the longitudinal direction of the elastic members 15-17, it can be stretched to a predetermined stretch rate without wrinkles. The elastic members 15-17 can be elongated elastic members such as rubber thread (illustrated example), as well as known elastic members in strip, net, film, etc., without any particular limitation. The elastic members 15-17 may be made of synthetic or natural rubber. The outer sheet layer 12S and the inner sheet layer 12H of the exterior bodies 12F, 12B can be bonded together, and the elongated elastic members 15-17 sandwiched therebetween can be secured using at least one of various application methods of hot melt adhesive and material welding, such as heat sealing or ultrasonic sealing. Since strongly securing the entire surfaces of the exterior bodies 12F, 12B impairs flexibility, it is preferable to either not secure or only weakly secure the elongated elastic members 15-17 in areas other than the adhesive bonded portions. In the illustrated example, hot melt adhesive is applied only to the outer peripheral surfaces of the elongated elastic members 15-17 using an application means such as a comb gun or a SureWrap nozzle, and then the elongated elastic members are sandwiched between the sheet layers 12S, 12H. This structure allows the elongated elastic members 15-17 to be secured to the sheet layers 12S, 12H and the sheet layers 12S, 12H together using only the hot melt adhesive applied to the outer peripheral surfaces of the elongated elastic members 15-17.

[0035] To explain the elastic members 15-17 in the illustrated example in more detail, a plurality of waist elastic members 17 are attached at intervals in the front-to-rear direction between the outer sheet layer 12S and the inner sheet layer 12H in the waist region W of the outer bodies 12F, 12B, stretched in the width direction at a predetermined stretch rate, forming a continuous waist stretch region throughout the width direction WD. Furthermore, one or more of the waist elastic members 17 arranged in the region adjacent to the lower waist region U may overlap the inner body 200, or may be provided on both sides of the width direction WD, excluding the central portion in the width direction that overlaps with the inner body 200. The waist elastic members 17 should have a thickness of 155-1880 dtex, particularly 470-1240 dtex (in the case of synthetic rubber; in the case of natural rubber, a cross-sectional area of ​​0.05-1.5 mm). 2 , especially 0.1 to 1.0 mm 2 It is preferable to provide about 2 to 15, and especially about 4 to 10, rubber threads of about 1 / 4" thick (approximately 1 / 4" thick) at intervals of 2 to 12 mm, especially 3 to 7 mm, and the resulting elongation rate in the width direction WD of the waist portion W is preferably about 150 to 400%, especially about 220 to 320%. Furthermore, it is not necessary for the waist portion W to use elastic members of the same thickness or to have the same elongation rate all along the front-to-back direction LD, and for example, the thickness or elongation rate may be different in some areas.

[0036] In addition, between the outer sheet layer 12S and the inner sheet layer 12H in the lower-waist portion U of the outer bodies 12F, 12B, a plurality of lower-waist elastic members 15 made of elongated elastic members are attached at intervals in the front-to-rear direction and stretched in the width direction at a predetermined stretch rate, forming lower-waist stretchable regions on both sides in the width direction WD except for the central portion in the width direction that overlaps with the inner body 200. The lower-waist elastic members 15 are made of a material having a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber, or a cross-sectional area of ​​0.05 to 1.5 mm in the case of natural rubber). 2 , especially 0.1 to 1.0 mm 2It is preferable to provide about 5 to 30 elastic threads of about 100 mm thick (approximately 1 / 2" thick) at intervals of 1 to 15 mm, especially 3 to 8 mm, and the resulting elongation rate in the width direction WD of the waist lower portion U is preferably about 200 to 350%, especially about 240 to 300%. Furthermore, it is not necessary for the waist lower portion U to use elastic members of the same thickness or have the same elongation rate all over its front-to-back direction LD, and thicknesses and elongation rates may vary in some areas.

[0037] In addition, between the outer sheet layer 12S and the inner sheet layer 12H in the buttocks cover portion 14 of the rear exterior body 12B, one or more buttocks cover elastic members 16 made of elongated elastic members are attached at intervals in the vertical direction and stretched in the width direction at a predetermined stretch rate on both sides in the width direction WD except for the width center portion overlapping with the interior body 200, forming buttocks cover stretchable regions on both sides in the width direction WD except for the width center portion overlapping with the interior body 200. The buttocks cover elastic members 16 have a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber, or a cross-sectional area of ​​0.05 to 1.5 mm in the case of natural rubber). 2 , especially 0.1 to 1.0 mm 2 It is preferable to fix about 2 to 10 rubber threads (approximately 150 to 300%, particularly 180 to 260%) at intervals of 5 to 40 mm, particularly 5 to 20 mm, each with an elongation of 150 to 300%, particularly 180 to 260%.

[0038] As shown in the figures, if the lower-waist elastic members 15 and the buttocks-covering elastic members 16 are provided on both sides in the width direction WD except for part or all of the portion overlapping with the inner body 200, the inner body 200 will not shrink more than necessary in the width direction, and will not look bulky or have reduced absorbency. This type of structure includes not only cases where the elastic members 15, 16 are present only on both sides in the width direction WD, but also cases where the elastic members 15, 16 are present across the inner body 200 from one side to the other in the width direction, but where the elastic members 15, 16 are cut into small pieces in the middle or all of the widthwise portion overlapping with the inner body 200, as shown by reference numeral 12X in Figures 2 and 4, so that no contractile force acts on them (effectively equivalent to not providing the elastic members 15, 16), and only both sides in the width direction WD are configured as contractile force acting portions. Of course, the arrangement of the waist lower elastic member 15 and buttocks covering elastic member 16 is not limited to the above example, and some or all of the waist lower elastic member 15 and buttocks covering elastic member 16 can be arranged across the inner body 200 from one side to the other side in the width direction so that an elastic force acts across the entire width direction, including the part that overlaps with the inner body 200.

[0039] (Interior body joint) The inner body 200 can be fixed to the outer bodies 12F, 12B by a joining method that uses material welding, such as heat sealing or ultrasonic sealing, or by a hot melt adhesive. In the illustrated example, the back surface of the inner body 200 is fixed to the inside surface of the outer bodies 12F, 12B via a hot melt adhesive HM3. This inner body joint 201 can be provided over almost the entire overlapping area, as shown in Fig. 2, and can also be provided in a portion of the inner body 200 excluding both widthwise ends, for example.

[0040] (interior body) The inner body 200 may have any shape, but is rectangular in the illustrated example. As shown in Figures 3 to 5, the inner body 200 comprises a liquid-permeable top sheet 30 that faces the wearer's skin, a liquid-impermeable film 11, and an absorbent element 50 sandwiched between them. Reference numeral 60 denotes side flaps 60 having flat gathers.

[0041] (Top sheet) The top sheet 30 can be made of any liquid-permeable material, such as a perforated or non-perforated nonwoven fabric or a perforated plastic sheet, but when the top sheet 30 also serves as a covering material for the liquid-impermeable film layer 64, as in the example shown in Figures 3 and 4, a nonwoven fabric is preferred for the top sheet 30.

[0042] If both sides of the top sheet 30 in the width direction WD do not also serve as covering materials for the liquid-impermeable film layer 64, the side edges of the absorbent element may be folded back to extend between the absorbent element 50 and the liquid-impermeable film 11.

[0043] (middle seat) Although not shown, an intermediate sheet (also called a "second sheet") that has a faster liquid permeability rate than the top sheet 30 can be provided to quickly transfer liquid that has permeated the top sheet 30 to the absorbent body. This intermediate sheet is intended to quickly transfer liquid to the absorbent body, improving the absorption performance of the absorbent body and preventing the phenomenon of absorbed liquid "flowing back" from the absorbent body. The intermediate sheet can also be omitted.

[0044] (Liquid-impermeable film) The material of the liquid-impermeable film 11 provided on the back side of the absorbent body 56 is not particularly limited, but examples include plastic films made of polyolefin resins such as polyethylene and polypropylene. A liquid-impermeable and moisture-permeable material, which has been favored in recent years from the viewpoint of preventing stuffiness, is preferably used for the liquid-impermeable film 11. A widely used moisture-permeable plastic film is a microporous plastic film obtained by kneading an inorganic filler into a polyolefin resin such as polyethylene or polypropylene, forming the sheet, and then stretching it uniaxially or biaxially.

[0045] The liquid-impermeable film 11 can be configured to extend into the side flaps to improve the waterproofness of the flat gathers, as in the examples shown in Figures 3 and 4, or it can be made wide enough to fit on the back side of the absorbent element 50 (not shown), or it can be folded back to the front side at the side edges of the absorbent element 50 and extend between the absorbent element 50 and the top sheet 30.

[0046] (Absorption element) 3, 4 and 9, the absorbent element 50 has an absorbent body 56 and a wrapping sheet 58 that wraps the entire absorbent body 56. The wrapping sheet 58 may be omitted.

[0047] (absorber) The absorbent body 56 can be formed from a fiber assembly. This fiber assembly can be made by stacking staple fibers such as cotton-like pulp or synthetic fibers, or it can be made from a filament assembly obtained by opening a tow (fiber bundle) of synthetic fibers such as cellulose acetate as needed. When cotton-like pulp or staple fibers are stacked, the fiber weight can be, for example, 100 to 300 g / m 2 In the case of a filament aggregate, for example, 30 to 120 g / m 2 In the case of synthetic fibers, the fineness is, for example, 1 to 16 dtex, preferably 1 to 10 dtex, and more preferably 1 to 5 dtex.

[0048] It is preferable that superabsorbent polymer particles are mixed into the fiber aggregate. The term "superabsorbent polymer particles" includes not only "particles" but also "powder." The superabsorbent polymer particles used in this type of disposable diaper can be used as is. For example, it is preferable that the percentage of particles remaining on a 500 μm standard sieve (JIS Z8801-1:2006) after sieving (shaking for 5 minutes) is 30% by weight or less, and it is also preferable that the percentage of particles remaining on a 180 μm standard sieve (JIS Z8801-1:2006) after sieving (shaking for 5 minutes) is 60% by weight or more.

[0049] The material for the superabsorbent polymer particles is not particularly limited, but is preferably one with a water absorption capacity of 40 g / g or more (JIS K7223-1996 "Test method for water absorption capacity of superabsorbent polymers") . Examples of superabsorbent polymer particles include starch-based, cellulose-based, and synthetic polymer-based materials, such as starch-acrylic acid (salt) graft copolymers, saponified starch-acrylonitrile copolymers, crosslinked products of sodium carboxymethylcellulose, and acrylic acid (salt) polymers. The shape of the superabsorbent polymer particles is preferably a commonly used powder or granular form, but other shapes can also be used.

[0050] The highly absorbent polymer particles preferably have a water absorption rate of 70 seconds or less, particularly 40 seconds or less. If the water absorption rate is too slow, the liquid supplied into the absorbent body 56 tends to flow back out of the absorbent body 56, which is known as backflow.

[0051] Furthermore, the highly absorbent polymer particles preferably have a gel strength of at least 1000 Pa. This effectively prevents the sticky feeling after absorbing liquid, even when the absorbent body 56 is bulky.

[0052] The basis weight of the highly absorbent polymer particles can be determined appropriately depending on the absorption amount required for the application of the absorbent body 56. Therefore, although it cannot be generalized, it is generally in the range of 50 to 350 g / m 2 The polymer weight can be 50 g / m 2 If it is less than 350g / m, it will be difficult to ensure sufficient absorption. 2 Above this, the effect saturates.

[0053] There are no particular limitations on the ratio of fibers to superabsorbent polymer particles in the absorbent body 56, but a weight ratio of fibers to superabsorbent polymer particles of 50:50 to 20:80 can result in a thinner absorbent body 56 when compared for the same area and the same absorption capacity. In this case, there are no particular limitations on the thickness 56t of the absorbent body 56, but it can be 3 to 15 mm.

[0054] The absorber 56 extends from a position in front of the crotch region M to a position behind the crotch region M, and preferably extends from the waist regions W, U of the front body F to the waist regions W, U of the back body B as shown in the illustrated example. The symbol 56X indicates the maximum width (total width) of the absorber 56.

[0055] In order to ensure an adequate amount of absorption in the crotch area M, it is preferable that the absorbent body 56 has a substantially rectangular shape. However, as shown in FIGS. 1, 2, 10, and 12, if the absorbent body 56 has a minimum width portion 52 in the crotch area M and widened portions 53 that gradually widen from the minimum width portion 52 to the maximum width portion 54 on the front side of the crotch area M and to the maximum width portion 54 on the rear side of the crotch area M, the width of the minimum width portion 52 and the widened portion 53 will be gradually increased. 53 A constricted portion 52 consisting of 53 This is preferable because it improves the fit around the inner thighs. In the latter case, to ensure a sufficient absorption amount in the crotch region M, it is preferable that width 52w of the narrowest part of absorber 56 in the crotch region M be 0.8 times or more the maximum width 56X of absorber 56. It is also preferable that the dimension of constricted portions 52, 53 in the front-to-rear direction be approximately 20 to 30% of total length Y of the product.

[0056] In addition, the crotch area M refers to the area where the absorbent body 56 has the above-mentioned constricted portions 52, 53. 53 The absorbent body 56 has a constricted portion 52, 53 However, if the outer shape in the unfolded state has a narrowed portion as in the illustrated example, it means the range in the front-to-back direction LD that has the narrowed portion of this outer shape (in the illustrated example, between the front outer body 12F and the rear outer body 12B), and if there are no narrowed portions, it means the part that is located in the center of the front-to-back direction LD and whose dimension in the front-to-back direction LD is 20 to 30% of the total length Y of the product.

[0057] (packaging sheet) When using a packaging sheet 58, the material can be a liquid-permeable material such as tissue paper, especially crepe paper, nonwoven fabric, polylaminated nonwoven fabric, or a sheet with small holes. However, it is preferable that the sheet does not allow the superabsorbent polymer particles to escape. When using nonwoven fabric instead of crepe paper, hydrophilic SMS nonwoven fabric (SMS, SSMMS, etc.) is particularly suitable, and polypropylene, polyethylene / polypropylene composite material, etc. can be used. The basis weight is 5 to 40 g / m 2 , especially 10 to 30 g / m 2 It is preferable that the following be used.

[0058] The packaging structure of the packaging sheet 58 can be determined as appropriate, but from the standpoint of ease of manufacturing and preventing leakage of superabsorbent polymer particles from the front and rear edges, it is preferable to wrap it around the front and rear surfaces and both side surfaces of the absorbent body 56 in a cylindrical shape, with the front and rear edges extending beyond the front and rear of the absorbent body 56, and to crush these extending portions in the front and rear directions and join them with a joining means such as a hot melt adhesive.

[0059] (Side flap) 1 to 4, 6 and 12, the side flaps 60 are a pair of sections extending out from the side edges of the absorbent body 56 on both sides in the width direction WD, each extending in the front-to-back direction LD from a region overlapping with the waist-around stretchable region of the front body piece F (in the illustrated example, the region having the lower-waist elastic member 15) to a region overlapping with the waist-around stretchable region of the back body piece B (in the illustrated example, the region having the lower-waist elastic member 15). Each side flap 60 has a side nonwoven fabric 66 extending from the front surface of the side flap 60, over the side edges of the side flap 60, to the back surface of the side flap 60, and elongated gathered elastic members 631 to 633 provided along the front-to-back direction LD between the front surface portion 61 and the back surface portion 62 of the side flap 60. The front surface portion 61 and the back surface portion 62 extend over the entire side flap 60 in the front-to-back direction LD. The front and rear ends of the side flaps 60 are not contracted in the front-to-back direction LD together with the gathered elastic members 631-633, and form side non-stretchable regions 70 having fastening portions 67 where the front surface portion 61 is fixed to the back surface portion 62. The portions of the side flaps 60 between the front and rear non-stretchable regions 70 form flat gathered regions 80 where the gathered elastic members 631-633 are fixed, contracting together with the gathered elastic members 631-633 in the front-to-back direction LD, and stretchable together with the gathered elastic members 631-633 in the front-to-back direction LD. This pants-type disposable diaper does not have three-dimensional gathers that rise up on the front side, but only has flat gathers on the side flaps 60. In the illustrated example, the fastening portions 67 indirectly fasten the front surface portion 61 to the back surface portion 62 via the liquid-impermeable film layer 64, but if no other member such as the liquid-impermeable film layer 64 is interposed, the front surface portion 61 will be directly fastened.

[0060] The dimension of the side non-elasticated region 70 in the front-to-back direction LD may be different at the front end and the rear end of the side flap 60 as in the illustrated example, or may be the same.

[0061] Characteristically, the fixed portion 67 of the side non-stretchable region 70 is a first distance w1 away from the side edge of the side non-stretchable region 70 toward the center in the width direction WD, and the portion between the side edge of the side non-stretchable region 70 and the fixed portion 67 has a hollow portion 70h that spans the entire width direction WD. The side non-stretchable region 70 also has a free portion 71 that is not fixed to the exterior body 12 and extends a second distance w2 from the side edge of the side non-stretchable region 70 toward the center in the width direction WD, and the second distance w2 is greater than half the dimension w3 of the fixed portion 67 in the width direction WD and less than half the first distance w1. Furthermore, the back surface portion 62 located between the free portion 71 and the fixed portion 67 is bonded to the waist stretchable region of the exterior body 12 with a hot melt adhesive HM3 or the like, and is contractible in the width direction WD together with the waist elastic members and is also extensible in the width direction WD together with the waist elastic members, with the maximum elongation in the width direction WD of the waist stretchable region being 200 to 320%. The hollow portion 70h is a portion where adjacent members in the thickness direction are not bonded, and in the illustrated example, the front surface portion 61 is not bonded to the liquid-impermeable film layer 64 adjacent to its back side and to the back surface portion 62, but appropriate modifications are possible, such as bonding the liquid-impermeable film layer 64 to the front surface portion 61 and not bonding the back surface portion 62 to the liquid-impermeable film 11.

[0062] With this configuration, as shown in FIG. 12, the maximum elongation in the width direction WD when the waist stretchable region is in the expanded state is max Then, the waist stretch area is 0.5~0.7E max 13, when the non-elastic side regions 70 are in a state of approximately the same stiffness as when worn, the back surface portion 62 of the region 72 between the free portion 71 and the fixed portion 67 shrinks in the width direction WD together with the waist-surrounding stretchable region, and this shrinkage causes the back surface portion 62 of the free portion 71 to rise up, while the front surface portion 61 rises and bulges, and this bulging portion collapses and widens when worn, so that the portion of the front surface portion 61 adjacent to the fixed portion 67 (the unfixed portion of the side nonwoven fabric 66) covers at least the side of the surface of the fixed portion 67. As a result, the hard surface of the fixed portion 67 in the non-elastic side regions 70 is less likely to come into contact with the skin, reducing deterioration in feel against the skin.

[0063] The dimensions of each part can be determined as appropriate, but the dimension w3 of the width direction WD of the fixing part 67 is preferably 3 mm or more, and particularly preferably 3 to 5 mm. The first distance w1 is preferably 15 to 20 mm. The second distance w2 is preferably 1 / 3 or less of the first distance w1. In particular, if 0.3(w1+w2) / 2≧w3, the bulge of the surface part 61 becomes larger, making it easier to cover a wide area of ​​the fixing part 67, which is preferable.

[0064] In particular, it is preferable that the second distance w2 is larger than the dimension of the fixing portion 67 in the width direction WD, since this makes it easier for the surface portion 61 to bulge.

[0065] The dimension of the fixing portion 67 in the front-to-back direction LD can be determined as appropriate, and is preferably about 0.8 to 1.0 times the dimension in the front-to-back direction LD of the side non-stretchable region 70. In the illustrated example, the edge of the fixing portion 67 on the plane gather region 80 side is spaced from the plane gather region 80 (for example, about 0.05 to 0.2 times the dimension in the front-to-back direction LD of the side non-stretchable region 70) and the edge on the opposite side coincides with the edge of the inner body 200, but this may be the other way around, or both edges in the front-to-back direction LD may coincide with the front and rear edges of the side non-stretchable region 70, or both edges in the front-to-back direction LD may be spaced from the front and rear edges of the side non-stretchable region 70 (for example, about 0.02 to 0.1 times the dimension in the front-to-back direction LD of the side non-stretchable region 70).

[0066] Of the side non-elasticated regions 70, the back surface portion 62 located at the fixed portion 67 and the portion located closer to the center in the width direction WD than that need not be fixed to the exterior body 12, but if the back surface portion 62 located at the fixed portion 67 is bonded to the waist stretched region of the exterior body 12 with a hot melt adhesive HM3 or the like, contracts in the width direction WD together with the waist elastic members, and is also extensible in the width direction WD together with the waist elastic members, as shown in Fig. 13, the fixed portion 67 contracts and becomes smaller in size in the width direction WD together with the waist stretched region, and the coverage rate of the fixed portion 67 by the surface portion 61 increases relatively. This is preferable because the surface of the fixed portion 67 is less likely to come into contact with the skin.

[0067] In addition, the fixing portion 67 may be spaced laterally from the side edge of the absorbent body 56 by a third distance w4, and the surface portion 61 may have an end portion 73 that protrudes from the fixing portion 67 toward the center in the width direction WD by a fourth distance w5 that is shorter than the third distance w4 and is not joined to an adjacent member on the back side. In this case, if the fourth distance w5 is greater than half the dimension of the fixed part 67 in the width direction WD, and the back surface part 62 located between the fixed part 67 and the side edge of the absorbent body 56 is joined to the waist stretchable region of the outer body 12 with a hot melt adhesive HM3 or the like, contracts in the width direction WD together with the waist elastic member, and is capable of stretching in the width direction WD together with the waist elastic member, then, as shown in Figure 13, the end part 73 of the surface part 61 protruding from the fixed part 67 toward the center in the width direction WD will rise along the shrinkage wrinkles of the member located on the back side, and the part of this raised part adjacent to the fixed part 67 (the unfixed part of the side nonwoven fabric 66) will cover at least the end part of the surface of the fixed part 67 toward the center in the width direction WD, making the surface of the fixed part 67 even less likely to come into contact with the skin, which is preferable.

[0068] The dimensions of each part can be determined as appropriate, but the third distance w4 is preferably about 5 to 8 times the dimension W3 in the width direction WD of the fixing part 67. Furthermore, the fourth distance w5 is preferably about 0.3 to 0.5 times the third distance w4.

[0069] The side flaps 60 preferably have planar gathered regions 80 that extend from the sides of the widest portion 54 of the absorber 56 in front of the crotch region M to the sides of the widest portion 54 of the absorber 56 behind the crotch region M. The planar gathered regions 80 are portions that incorporate elongated gathered elastic members 631-633 that extend along the front-to-back direction LD, and are portions that contract in the front-to-back direction LD together with the gathered elastic members 631-633, and are also stretchable in the front-to-back direction LD together with the gathered elastic members 631-633.

[0070] It is desirable that the width of the side flaps 60 be sufficiently wide to reduce the effect of leg movement on the sides of the absorber 56. Therefore, the width 60w of the side flaps 60 is preferably 0.1 to 0.5 times the maximum width 56X of the absorber 56, more preferably 0.3 to 0.5 times, and particularly preferably 0.4 to 0.5 times. Furthermore, the arrangement of the gathered elastic members 631 to 633 can be determined as appropriate, but as shown in the illustrated example, the gathered elastic members 631 to 633 consist of a first gathered elastic member 631 attached laterally from the side edge of the widest part 54 of the absorbent body 56 at a first distance d1, a second gathered elastic member 632 attached laterally from the first gathered elastic member 631 at a second distance d2, and a third gathered elastic member 633 attached repeatedly from the second gathered elastic member 632 to the side edge of the side flap 60 at a third distance d3 (i.e., no other elastic members are included), and it is desirable that the second distance d2 is 1.5 to 5 times the third distance d3 and the first distance d1 is 0.3 to 0.8 times the second distance d2. It is more desirable that the second distance d2 is 1.5 to 2.5 times the third distance d3, and the first distance d1 is 0.3 to 0.7 times the second distance d2. More specifically, when used for babies, the width of the side flaps 60 is preferably 30 to 50 mm, and particularly preferably 40 to 50 mm.

[0071] Furthermore, when the first gathered elastic member 631 has a first thickness and is attached to the side flap 60 at a first stretch rate, the second gathered elastic member 632 has a second thickness and is attached to the side flap 60 at a second stretch rate, and the third gathered elastic member 633 has a third thickness and is attached to the side flap 60 at a third stretch rate, (a1) the first stretch rate is equal to or greater than the second stretch rate and the third stretch rate. and the first thickness is 0.95 to 1.05 times the elongation rate of the second and third thicknesses and 1.2 to 1.5 times the elongation rate of the second and third thicknesses, or (b1) the first thickness is 0.95 to 1.05 times the elongation rate of the second and third thicknesses and the first elongation rate is 1.2 to 1.5 times the elongation rate of the second and third thicknesses, or (c1) the first thickness is 1.2 to 1.5 times the elongation rate of the second and third thicknesses and the first elongation rate is 1.2 to 1.5 times the elongation rate of the second and third thicknesses. More preferably, (a2) the first elongation rate is 0.95 to 1.05 times the second and third elongation rates and the first thickness is 1.3 to 1.4 times the second and third thicknesses, or (b2) the first thickness is 0.95 to 1.05 times the second and third thicknesses and the first elongation rate is 1.3 to 1.5 times the second and third elongation rates, or (c2) the first thickness is 1.3 to 1.4 times the second and third thicknesses and the first elongation rate is 1.3 to 1.5 times the second and third elongation rates.

[0072] Long, thin elastic members such as rubber threads or rubber strips can be used as the gathered elastic members 631 to 633. When rubber threads are used, the thickness of the first to third threads is preferably 400 to 950 dtex, and more preferably 470 to 780 dtex. The elongation percentages of the first to third threads are preferably 200 to 320%, and more preferably 260 to 320%.

[0073] In this way, when the width of the side flap 60 having plane gathers is ensured to be sufficiently wide, the first gathered elastic member 631 is provided near the absorbent body 56, the second gathered elastic member 632 is provided at a position spaced some distance to the side from there, and the third gathered elastic member 633 is repeatedly provided at narrow intervals up to the side edge of the side flap 60, and the force required to stretch the first gathered elastic member 631 provided near the absorbent body 56 is stronger than that of the second gathered elastic member 632 and the third gathered elastic member 633, the appropriate wearing state will be as shown in Figures 7 and 8. That is, in the crotch region M, the portion between the side edge of the absorbent body 56 and the second gathered elastic member 632 forms a first portion 60A extending obliquely upward toward the base of the wearer's inner thigh, and the portion from the second gathered elastic member 632 to the side edge of the side flap 60 forms a second portion 60B extending obliquely downward along the inner thigh. Here, the first portion 60A is lifted up more strongly by the first gathered elastic member 631 than the second portion 60B, making it difficult to move, and the second portion 60B, which is positioned a certain distance away from the first gathered elastic member 631, comes into close contact with the inner thigh, using the first gathered elastic member 631 as support. Therefore, even if the second portion 60B moves in response to the movement of the leg, the portion between the first gathered elastic member 631 and the second gathered elastic member 632 deforms and exhibits a cushioning effect, making it difficult for the movement of the second portion 60B to be transmitted to the absorber 56 via the first portion 60A, thereby reducing the risk of the sides of the absorber 56 collapsing.

[0074] As shown in the illustrated example, when the absorber 56 has a minimum width portion 52 in the crotch region M and has widened portions 53 that gradually widen from the minimum width portion 52 to the front maximum width portion 54 and the rear maximum width portion 54, if the distance d4 in the width direction WD between the side edge of the minimum width portion 52 of the absorber 56 and the first gathered elastic member 631 is too wide, the portion between the side edge of the minimum width portion 52 of the absorber 56 and the first gathered elastic member 631 is likely to be significantly recessed on the back side, causing body waste to accumulate on the side flaps 60 or making it easy for toes to get caught when worn. It is preferable that the distance d4 in the width direction WD between the side edge of the minimum width portion 52 of the absorber 56 and the first gathered elastic member 631 be 1.1 to 1.5 times, and particularly 1.1 to 1.3 times, the second distance d2.

[0075] The structure of the side flaps 60 can be determined as appropriate, but the illustrated example is preferred because it is simple and has excellent waterproof properties and ease of manufacture. That is, the side flaps 60 in the illustrated example have a surface nonwoven fabric layer that forms the surface of the side flaps 60 (in the illustrated example, the side portions of the top sheet 30 and the surface portions 61 of the side nonwoven fabric 66), a back nonwoven fabric layer that forms the back surface of the side flaps 60 (in the illustrated example, the back portion 62 of the side nonwoven fabric 66), gathered elastic members 631-633 provided between the surface nonwoven fabric layer and the back nonwoven fabric layer in the front-to-rear direction, and a liquid-impermeable film layer 64 that extends from the base end to a position closer to the tip than the base end and is sandwiched between the surface nonwoven fabric layer and the back nonwoven fabric layer. In the illustrated example, a nonwoven fabric-free portion 65 is formed in a portion of the side flap 60 in the width direction WD, where the surface nonwoven fabric layer is absent and the liquid-impermeable film layer 64 is exposed. However, the side flap 60 may be configured so that the surface nonwoven fabric layer is present over substantially the entire width direction WD, for example, by extending the surface portion 61 of the side nonwoven fabric 66 to the side of the topsheet 30. When the nonwoven fabric-free portion 65 is provided, its width can be determined as appropriate, but is preferably 10 mm or less. If water-blocking properties can be ensured by the surface nonwoven fabric layer and the back nonwoven fabric layer alone, the liquid-impermeable film layer 64 need not be provided between the surface nonwoven fabric layer and the back nonwoven fabric layer. Furthermore, when the liquid-impermeable film 11 is provided, the liquid-impermeable film layer 64 may be fixed to one or both of the surface nonwoven fabric layer and the back nonwoven fabric layer, or may not be fixed to both, as long as the gathered elastic members 631-633 can be fixed and the hollow portion 70h described above is formed.

[0076] In particular, if there is a portion 65 (including a gap in the surface nonwoven fabric layer with almost no width) between the first gathered elastic member 631 and the second gathered elastic member 632 where the surface nonwoven fabric layer is not present and the liquid-impermeable film layer 64 is exposed, this portion will have low rigidity, and the portion between the first gathered elastic member 631 and the second gathered elastic member 632 will be particularly prone to deformation, which is preferable.

[0077] The portion between the first gathered elastic member 631 and the second gathered elastic member 632 is preferably low in rigidity since it is the portion that exerts the aforementioned cushioning effect. As shown in the illustrated example, when the portion between the first gathered elastic member 631 and the second gathered elastic member 632 has a three-layer structure consisting of a front nonwoven fabric layer, a back nonwoven fabric layer, and a liquid-impermeable film layer 64 sandwiched therebetween, and the front nonwoven fabric layer and the liquid-impermeable film layer 64 are bonded together via a first hot-melt adhesive HM1, and the back nonwoven fabric layer and the liquid-impermeable film layer 64 are bonded together via a second hot-melt adhesive HM2, the bending resistance of each of the front nonwoven fabric layer and the back nonwoven fabric layer, as measured by the 41.5° cantilever method defined in JIS L 1913:2010, is preferably 0.2 to 2.2 mN·cm in the longitudinal direction LD and 0.05 to 0.5 mN·cm in the width direction WD, and particularly preferably 0.4 to 0.6 mN·cm in the longitudinal direction LD and 0.07 to 0.1 mN·cm in the width direction WD. The liquid-impermeable film layer 64 preferably has a bending resistance of 0.006 to 0.05 mN·cm in the longitudinal direction LD and 0.006 to 0.05 mN·cm in the width direction WD, as measured by the 41.5° cantilever method specified in JIS L 1913:2010, and particularly preferably has a bending resistance of 0.006 to 0.02 mN·cm in the longitudinal direction LD and 0.006 to 0.02 mN·cm in the width direction WD. The amount of application of the first hot melt adhesive HM1 is 1 to 10 g / m 2 , especially 1 to 5 g / m 2 The amount of the second hot melt adhesive HM2 to be applied is preferably 1 to 10 g / m 2 , especially 1 to 5 g / m 2 It is preferable that:

[0078] 14, when the back body B is placed face down on a horizontal surface and only the outer casing 12 is unfolded along the flat surface from its natural length and viewed from above, the acute-side crossing angle α between the front-to-back direction LD and an imaginary line connecting the side edges of the absorber 56 and the first gathered elastic member 631 among the outlines of the crotch region M is 15 to 40 degrees, the acute-side crossing angle γ between the front-to-back direction LD and an imaginary line connecting the positions of adjacent third gathered elastic members 633 is 50 to 90 degrees, and the acute-side crossing angle β between the front-to-back direction LD and an imaginary line connecting the positions of the first gathered elastic member 631 and the second gathered elastic member 632 is preferably greater than α but less than γ, since this improves the cushioning effect described above. The angle α is more preferably 25 to 35 degrees. The angle γ is more preferably 55 to 70 degrees. The angle β is more preferably approximately 1.3 to 1.7 times the value of α.

[0079] The fastening portions 67 in the side non-stretchable regions 70 may be formed by indirectly fastening the front portion 61 of the side nonwoven fabric 66 to the back portion 62 (in the illustrated example, a liquid-impermeable film layer 64 is interposed between the front portion 61 and the back portion 62) or directly. The fastening portions 67 may be formed by at least one of a hot melt adhesive and material welding (heat sealing, ultrasonic sealing, etc.). The fastening portions 67 in the illustrated example are formed by integrally welding the front portion 61 and the back portion 62 of the side nonwoven fabric 66 and the liquid-impermeable film layer 64 located therebetween. While it is sufficient that a portion of the side non-stretchable regions 70 overlaps with the waist-surrounding stretchable regions of the outer body 12, it is preferable that the entire side non-stretchable regions 70 overlap with the waist-surrounding stretchable regions of the outer body 12. The flat gathered regions 80 (portions of the side flaps 60 that stretch together with the gathered elastic members 631-633) extend entirely between the front and rear side non-stretchable regions 70.

[0080] As long as the gathered elastic members 631-633 are provided between the front nonwoven fabric layer and the back nonwoven fabric layer (and therefore not in the nonwoven fabric-free portion 65), they can be provided on the front side of the liquid-impermeable film layer 64 built into the side flap 60 as shown in Fig. 3, or on the back side (not shown). As long as the contractile force of the gathered elastic members 631-633 is not applied to the side non-elasticated region 70, the ends thereof may be left unfixed to their natural lengths.

[0081] The positioning of the liquid-impermeable film layer 64 on the side flap 60 can be determined as appropriate, and if waterproofing is a priority, it is preferable for it to extend across the entire width of the side flap. However, in order to ensure flexibility of the side edges of the side flap, it is also preferable not to have the liquid-impermeable film layer 64 in the side edge portion (for example, from between the most lateral third gathered elastic member and the second adjacent third gathered elastic member to the side edge of the side flap).

[0082] The surface nonwoven fabric layer and the back nonwoven fabric layer may be made of a nonwoven fabric different from the top sheet 30 and the cover nonwoven fabric layer 13, but are also preferably made of the same nonwoven fabric as the top sheet 30 and the cover nonwoven fabric layer 13. That is, in the illustrated example, the top sheet 30 is made of a nonwoven fabric and is configured so that both sides in the width direction WD extend beyond the side edges of the absorbent body 56, and a side nonwoven fabric 66 that also serves as the cover nonwoven fabric layer 13 is provided on the back side of the absorbent body 56 and both sides in the width direction WD extend laterally from the side edges of the absorbent body 56, and the side edges of this side nonwoven fabric 66 are folded back, with the tips of the folded back portions 66r spaced apart from the tip of the top sheet 30. A liquid-impermeable film 64 is also provided at least between the folded back portions 66r of the nonwoven fabric 66 and between the top sheet 30 and the nonwoven fabric 66. As a result, a back nonwoven fabric layer including the back surface portion 62 is formed by the portions of the side nonwoven fabric 66 other than the folded-back portions 66r, a front nonwoven fabric layer is formed by the folded-back portions 66r of the side nonwoven fabric 66 and the portions of the top sheet 30 that extend laterally of the absorbent body 56, and a nonwoven fabric-free portion 65 is formed by the portion where the folded-back portions 66r of the side nonwoven fabric 66 are separated from the top sheet 30. In this way, by forming the front nonwoven fabric layer on the absorbent body 56 side of the nonwoven fabric-free portion 65 of the side flap 60 from the top sheet 30 and forming the rest from the folded-back portions 66r of the side nonwoven fabric 66, the nonwoven fabric-free portion 65 can be provided without cutting the material, and the structure is very simple and easy to manufacture.

[0083] In this case, it is preferable that the liquid-impermeable film layer 64 built into the side flaps 60 extends from one side flap 60 through the back side of the absorber 56 to the other side flap 60, as shown in Figures 3 and 4, because this not only ensures water-tightness of the side flaps 60 but also the back side of the absorber 56, but it is also possible to provide the liquid-impermeable film layer 64 built into the side flaps 60 separately from the liquid-impermeable film 11 covering the back side of the absorber 56. In the latter case, the material of the liquid-impermeable film layer 64 built into the side flaps 60 and the material of the liquid-impermeable film 11 covering the back side of the absorber 56 may be the same or different (for example, less rigid).

[0084] To bond adjacent layers in the thickness direction of the side flaps 60 and to secure the gathered elastic members 631-633 sandwiched therebetween, at least one of various application methods of hot melt adhesive and material welding, such as heat sealing and ultrasonic sealing, can be used. Bonding the entire surfaces of the layers adjacent to the front and back sides of the gathered elastic members 631-633 together impairs flexibility, so it is preferable to not bond or only weakly bond portions of the gathered elastic members 631-633 other than the adhesive portions. In the illustrated example, hot melt adhesive is applied only to the outer peripheral surfaces of the gathered elastic members 631-633 using an application means such as a comb gun or a SureWrap nozzle, and the gathered elastic members 631-633 are sandwiched between the adjacent layers on the front and back sides. This structure allows the hot melt adhesive applied only to the outer peripheral surfaces of the gathered elastic members 631-633 to bond the gathered elastic members 631-633 to the layers adjacent to them on the front and back sides, and to bond the layers adjacent to the front and back sides of the gathered elastic members 631-633 to each other. If there are edges of a nonwoven fabric or sheet that are separated from the gathered elastic members 631-633, such as the edges of the top sheet 30 in the illustrated example, a separate hot melt adhesive (first hot melt adhesive HM1 in the illustrated example) can be applied to secure them.

[0085] The side nonwoven fabric 66 may be a nonwoven fabric that is soft and has excellent uniformity and hiding power, such as a spunbond nonwoven fabric (SS, SSS, etc.), an SMS nonwoven fabric (SMS, SSMMS, etc.), or a meltblown nonwoven fabric, and is treated with a water repellent treatment such as silicone as necessary. The fiber weight is 10 to 30 g / m. 2 3 and 4, as can be seen from the fact that the surface nonwoven fabric layer on the proximal side of the nonwoven fabric-free portion 65 is formed by the top sheet 30, it is also possible to make the materials of the surface nonwoven fabric layer and the back nonwoven fabric layer partially different, and it is also possible to make the materials of the surface nonwoven fabric layer and the back nonwoven fabric layer different.

[0086] (Compression section) In order to improve the shape retention of the absorbent body 56, compressed portions can be provided by compressing the absorbent body 56 in the thickness direction. The compressed portions of the absorbent body 56 may be formed by subjecting only the absorbent body 56 to embossing or the like without heating, or by embossing a laminated member other than the absorbent body 56, such as the absorbent element 50 (i.e., together with the packaging sheet 58) or the inner body 200, to form compressed portions 51 including the absorbent body 56 and other laminated members. The compressed portions 51 are preferably provided in a continuous grid pattern as shown in Figures 10 and 11, or in a dotted pattern scattered at intervals (not shown).

[0087] The dimensions and number of the compressed portions 51 can be determined as appropriate, but when the compressed portions 51 have a bottom surface and side surfaces, the depth 51h of the compressed portions 51 is preferably 1 to 5 mm, and the ratio of the bottom surfaces of the compressed portions 51 to the surface of the absorbent element 50 is preferably 5 to 25%. Furthermore, when the compressed portions 51 are formed in a pattern in which they are spaced apart, the area of ​​the bottom surfaces of the compressed portions 51 can be determined as appropriate, but is preferably 5 to 15 mm, for example. 2The shape of the bottom surface of the compressed portions 51 can be one or more types selected from appropriate shapes such as a circle, an ellipse, a polygon, a rectangle, a rounded rectangle (two parallel lines of equal length and two semicircles), etc. The pattern in which the compressed portions 51 are scattered at intervals includes not only regular patterns such as a staggered pattern or a matrix pattern, but also irregular patterns such as a grid pattern.

[0088] In particular, when the compressed portions 51 are arranged in a continuous grid pattern, the pulp fibers and superabsorbent polymer particles that make up the absorbent body 56 are constrained within the unit frame 51f (see Figure 11) consisting of the compressed portions 51, thereby preventing the absorbent body 56 from twisting or cracking.

[0089] When the compressed portions 51 are provided in a grid pattern, the width 51w of the groove-shaped compressed portions 51 (the width of the bottom of the compressed portions formed in the absorbent element 50) can be determined as appropriate, but in general, it is preferable that it be approximately 1 to 3 mm.

[0090] The thickness 51t of the compressed portion 51 can be determined as appropriate, but in normal cases it is preferably 15 to 35% of the maximum value of the thickness 50t of the absorbent element 50.

[0091] The shape of the unit frame 51f is not particularly limited, and may be a substantially square as in the illustrated example, a substantially rhombic shape (excluding a square), a substantially rectangular shape, a substantially triangular shape, or any other polygonal shape. Furthermore, as long as the compression section 51 is arranged in a lattice pattern, the compression section 51 may include unit frames 51f of different shapes.

[0092] 10 and 11, one preferred pattern of the lattice-shaped compressed portion 51 is a diagonal lattice pattern made up of first portions 51a extending in a direction inclined at 40 to 50 degrees clockwise with respect to the front-rear direction LD in plan view and second portions 51b extending in a direction inclined at 40 to 50 degrees counterclockwise with respect to the front-rear direction LD in plan view. In this case, the shape of the unit frame 51f is approximately rhombic.

[0093] The dimensions of the unit frame 51f can be determined as appropriate, but if they are too large, the rigidity improvement effect will be poor, and if they are too small, they will be too hard. Therefore, in general, it is preferable that the dimension 51x of the unit frame 51f in the width direction WD be approximately 15 to 20 mm. It is also preferable that the dimension 51y of the unit frame 51f in the front-to-rear direction LD be approximately 15 to 20 mm.

[0094] The compressed portion 51 may be formed over the entire absorbent element 50 or may be formed over only a portion thereof.

[0095] <Explanation of terms used in the specification> In the present specification, the following terms have the following meanings unless otherwise specified in the specification.

[0096] "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.

[0097] "Front side" means the side closest to the wearer's skin when worn, and "reverse side" means the side farthest from the wearer's skin when worn.

[0098] "Front" means the side closest to the wearer's skin when worn, and "back" means the side away from the wearer's skin when worn.

[0099] "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.

[0100] "Gel strength" is measured as follows: 1.0 g of superabsorbent polymer is added to 49.0 g of artificial urine (a mixture of 2 wt% urea, 0.8 wt% sodium chloride, 0.03 wt% calcium chloride dihydrate, 0.08 wt% magnesium sulfate heptahydrate, and 97.09 wt% ion-exchanged water) and stirred with a stirrer. The resulting gel is left in a constant temperature and humidity chamber at 40°C and 60% RH for 3 hours, then returned to room temperature, and the gel strength is measured using a card meter (I.techno Engineering: Curdmeter-MAX ME-500).

[0101] "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.

[0102] The "thickness" of thick members such as the absorber 56, the absorbent element 50, and the bottom of the compression section 51 is measured using a thickness measuring device (Peacock, Dial Thickness Gauge, Model H (measurement range 0 to 10 mm, measurement area 10 mm diameter circular terminal, measurement 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.

[0103] 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.

[0104] The water absorption capacity is measured according to JIS K7223-1996 "Test method for water absorption capacity of superabsorbent resins."

[0105] The water absorption rate is the "time to the end point" when 2g of superabsorbent polymer and 50g of physiological saline are used and tested according to JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymers."

[0106] "Deployed state" means a flat, deployed state without contraction (including any contraction, such as contraction due to elastic members) or slack.

[0107] "Maximum elongation" refers to the maximum elongation in the stretch direction in the stretchable region (i.e., the elongation at the elastic limit, which is equivalent to the elongation in the unfolded state), and is expressed as a percentage of the unfolded length, with the natural length being 100%.

[0108] Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not in the natural length state.

[0109] If no environmental conditions are specified for a test or measurement, the test or measurement shall be carried out in a test room or device under standard conditions (temperature 23±1°C, relative humidity 50±2%). [Industrial Applicability]

[0110] The present invention can be used in pants-type disposable wearing articles such as the pants-type disposable diaper described above. [Explanation of symbols]

[0111] 11...liquid-impermeable film, 12...exterior body, 12A...side seal portion, 12B...rear exterior body, 12F...front exterior body, 12H...inner sheet layer, 12S...outer sheet layer, 13...cover nonwoven fabric layer, 14...buttocks cover portion, 15...lower waist elastic member, 16...buttocks cover elastic member, 17...waist elastic member, 200...interior body, 201...interior body joint portion, 30...top sheet, 50...absorbent element, 51...compression portion, 52...minimum width portion, 53...widened portion, 54...maximum width portion, 56...absorbent body, 56C...central region, 56S...side region, 58...packaging sheet, 60...side flap, 60A...first portion, 60B...second portion, 61...surface portion, 62...back portion, 631-633...gathered elastic member, 631...first gathered elastic member, 63 2...second gathered elastic member, 633...third gathered elastic member, 64...liquid-impermeable film layer, 65...non-woven fabric-absent portion, 66...side nonwoven fabric, 66r...folded-back portion, 67...fixed portion, 70...side non-stretchable region, 70h...hollow portion, 71...free portion, 73...end portion, 80...flat gathered region, B...back body portion, F...front body portion, HM1...first hot melt adhesive, HM2...second hot melt adhesive, HM3...hot melt adhesive, L...middle region, LD...front to back direction, M...crotch region, T...torso region, U...lower waist portion, W...waist portion, WD...width direction, WO side...waist opening WO, d1...first distance, d2...second distance, d3...third distance, w1...first distance, w2...second distance, w4...third distance, w5...fourth distance.

Claims

1. an exterior body having a front waistband, a back waistband, and side seals formed by joining both side portions thereof; An inner body joined to the middle of the outer body in the width direction so as to extend from the waist portion of the front body through the crotch portion to the waist portion of the back body; a waist opening formed by the front edge of the front body and the rear edge of the back body; leg openings provided on both sides of the interior body, the inner body has an absorbent body that continues from a position in front of the crotch region to a position in back of the crotch region, The waist portion of the front body and the waist portion of the back body have waist stretchable regions provided on at least both sides in the width direction, The waist elastic region incorporates a waist elastic member, contracts in the width direction together with the waist elastic member, and is extensible in the width direction together with the waist elastic member; A pair of side flaps extend from the side edges of the absorbent body to both sides in the width direction on both sides of the inner body, extending in the front-rear direction from an area overlapping the waist-surrounding elastic region of the front body to an area overlapping the waist-surrounding elastic region of the back body, The side flaps each include a side nonwoven fabric extending from the front surface of the side flap through the side edge of the side flap to the back surface of the side flap, and an elongated gathered elastic member provided along the front-to-rear direction between the front surface and back surface of the side nonwoven fabric, The front surface portion and the back surface portion extend over the entire front and rear of the side flap, The front end and the rear end of the side flap do not contract in the front-to-rear direction together with the gathered elastic member, and the front surface portion is fixed directly or indirectly to the back surface portion, forming a side non-stretchable region. The portions of the side flaps between the front and rear side non-elastic regions are flat gathered regions to which the gathered elastic members are fixed, and which contract in the front-to-rear direction together with the gathered elastic members, and which are stretchable in the front-to-rear direction together with the gathered elastic members; Does not have three-dimensional gathers that rise up on the front side A pants-type disposable wearing article; the fixed portion is spaced a first distance from the side edge of the side non-elastic region toward the center in the width direction, A portion between the side edge of the side non-elastic region and the fixed portion has a hollow portion extending over the entire width direction thereof, the side non-stretchable region has a free portion that is not fixed to the exterior body and extends from a side edge of the side non-stretchable region to a position a second distance toward the center in the width direction, the second distance is greater than half the width of the fixing portion and less than half the first distance; the back surface portion located between the free portion and the fixed portion is joined to the waist-surrounding elastic region of the exterior body, contracts in the width direction together with the waist-surrounding elastic member, and is extensible in the width direction together with the waist-surrounding elastic member; The maximum stretch in the width direction of the waist elastic region is 200 to 320%. A pants-type disposable wearing article characterized by:

2. the first distance is 15 to 20 mm; the second distance is equal to or less than one-third of the first distance; The width direction dimension of the fixing portion is 3 mm or more.

2. The pants-type disposable wearing article according to claim 1.

3. When the first distance is w1, the second distance is w2, and the dimension of the fixing portion in the width direction is w3, 0.3(w1+w2) / 2≧w3 is satisfied.

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

4. the second distance is greater than the width dimension of the fixing portion; 3. The pants-type disposable wearing article according to claim 1 or 2.

5. The back surface portion located at the fixing portion is joined to the waist-surrounding elastic region of the exterior body, and is contracted in the width direction together with the waist-surrounding elastic member, and is also stretchable in the width direction together with the waist-surrounding elastic member.

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

6. the fixing portion is laterally spaced a third distance from a side edge of the absorbent body; the surface portion has an end portion that protrudes from the fixing portion toward the center in the width direction by a fourth distance that is shorter than the third distance and is not joined to an adjacent member on the back side, the fourth distance is greater than half the width of the fixing portion, a back surface portion located between the fixing portion and the side edge of the absorbent body is joined to the waist-surrounding elastic region of the exterior body, and is contracted in the width direction together with the waist-surrounding elastic member, and is also extensible in the width direction together with the waist-surrounding elastic member; 3. The pants-type disposable wearing article according to claim 1 or 2.

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