Absorbent article and method for manufacturing absorbent member used therein

Abstract

The present invention addresses the problem of improving the shape retention of an absorbent body and reducing the breakage of a packaging sheet. The above-mentioned problem is solved by the following solution: an absorbent member having an absorbent body (56) in which pulp fibers and highly absorbent polymer particles are mixed and aggregated, and a packaging sheet (58) which is made of crepe paper and wraps the absorbent body; in the absorbent member (50), high-compression sections (51) which are compressed in the thickness direction TD so as to be recessed from the surface of the absorbent member (50) into the absorbent body (56) are arranged at intervals, portions other than the high-compression sections (51) are non-high-compression sections (52) which are thicker than the high-compression sections (51) and have a lower density, and the high-compression sections (51) have an outer shape without inflection points and bending points. The diameter of the maximum inscribed circle (53) inscribed with the outer shape of the high-compression part (51) is 2-5 mm, the circumference of the outer shape of the maximum inscribed circle (54) inscribed with the outer shape of the high-compression part (51) is 1-2.5 times the circumference of the maximum inscribed circle (54) inscribed with the outer shape of the non-high-compression part (52), and the diameter of the maximum inscribed circle (54) inscribed with the outer shape of the non-high-compression part (52) is 6.5 mm or less.

Description

Technical Field

[0001] The present invention relates to an absorbent article such as a disposable diaper and a method for producing an absorbent member used therein. Background Art

[0002] In absorbent articles, an absorbent body formed by mixing and aggregating pulp fibers and superabsorbent polymer particles is generally used. In order to improve the shape retention during and after manufacturing, such an absorbent body is generally built into the form of an absorbent member formed by winding a packaging sheet made of crepe paper or the like (for example, see Patent Document 1).

[0003] When the absorbent member of an absorbent article is sandwiched between the legs, it is subjected to forces in various directions from both sides in the width direction due to the movement of the legs such as walking, so the crotch portion is required to have good fit, and on the other hand, it is also required to have shape retention to prevent the shape of the absorbent body from being damaged such as wrinkles and damage. Of course, the absorbent member of a disposable diaper is also required to ensure absorption performance in the crotch portion.

[0004] As a method for improving the shape retention of the absorbent body, there is known a method of providing a highly compressed portion formed by compressing the absorbent member in the thickness direction by embossing or the like in a grid-like pattern (see, for example, Patent Documents 1 and 2). However, if the packaging sheet wrapping the absorbent body is crepe paper, the crepe paper may be damaged at the edge of the highly compressed portion or between adjacent highly compressed portions when the highly compressed portion is formed. If the packaging sheet is damaged, the superabsorbent polymer particles may escape from the portion and overflow onto the surface of the absorbent article, which is not preferred.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent No. 5709584 Summary of the invention

[0008] Problems to be solved by the invention

[0009] Therefore, the main subject of the present invention is to improve the shape retention of the absorbent body and reduce the damage of the packaging sheet.

[0010] Means for solving problems

[0011] The inventors of the present invention have conducted research on forming a highly compressed portion compressed in the thickness direction in an absorbent body formed by mixing and aggregating pulp fibers and superabsorbent polymer particles, and have accidentally discovered that the shape retention of the absorbent body can be improved while reducing the possibility of damage to the packaging sheet. The absorbent article described below is based on this technical idea.

[0012] <Method 1>

[0013] An absorbent article, characterized in that

[0014] With crotch,

[0015] The absorbent member includes an absorbent body disposed in a front-back direction range including the crotch portion, and a wrapping sheet made of crepe paper wrapping the absorbent body.

[0016] The absorbent is formed by mixing and aggregating pulp fibers and superabsorbent polymer particles.

[0017] The absorbent member has highly compressed portions arranged at intervals in the thickness direction so as to be recessed from the surface or back surface of the absorbent member into the absorbent body.

[0018] The portion other than the high compression portion in the arrangement region of the high compression portion is a non-high compression portion which is thicker and has a lower density than the high compression portion.

[0019] The high compression portion has an outer shape without an inflection point or a bending point, and the diameter of the largest inscribed circle inscribed in the outer shape of the high compression portion is 2 to 5 mm, and the circumference of the outer shape of the high compression portion is 1 to 2.5 times the circumference of the largest inscribed circle inscribed in the outer shape of the high compression portion,

[0020] The diameter of the largest inscribed circle inscribed in the outer shape of the non-highly compressed portion is 6.5 mm or less.

[0021] (Effect)

[0022] The absorbent article is characterized in that, in an absorbent member formed by mixing and aggregating pulp fibers and superabsorbent polymer particles and wrapping them with crepe paper, a high compression portion having a specific size and shape is arranged more densely than before. That is, the high compression portion is a high-density portion of the absorbent member that is compressed in the thickness direction by pressing (direct pressure) and has a substantially equal thickness, and is the bottom of a pit that is sunken from the surface or back of the absorbent member. On the other hand, the non-high compression portion is a portion that is thicker and has a lower density than the high compression portion, but even in the non-high compression portion, the absorbent body will be deformed in a manner of being stretched by the deformation of the high compression portion near the high compression portion, and as a result, the thickness decreases and the density increases as it approaches the high compression portion. Therefore, if the high compression portion having a certain degree of size is arranged more densely than before, the area where the thickness of the non-high compression portion is reduced increases. And as a result, the strain generated in the packaging sheet when the high compression portion is formed is reduced (the tensile force applied is weakened), and the packaging sheet is not easily damaged.

[0023] Furthermore, even in the absence of a high compression portion, the absorber is deformed in the vicinity of the high compression portion by being stretched by the deformation of the high compression portion, resulting in an advantage that the absorber becomes thinner than when there is no high compression portion.

[0024] From these aspects, it is important that the high compression portion has a shape that can contain a sufficiently large circle. In addition, it is also important that the shape of the high compression portion is not too long in one direction or does not have an overly complex shape. In addition, it is also important that the diameter of the largest inscribed circle inscribed in the shape of the non-high compression portion is small so that the configuration of the high compression portion does not become sparse (the non-high compression portion does not continue for a long time in all directions).

[0025] Conventionally, it was considered undesirable to arrange the high compression parts densely, and therefore it was unexpected that such an effect could be achieved by such a simple change as described above.

[0026] <Method 2>

[0027] The absorbent article according to the first aspect, wherein:

[0028] The weight per unit area of ​​the pulp fibers in the absorbent is 100 to 500 g / m 2 ,

[0029] The weight ratio of pulp fiber to superabsorbent polymer particles in the absorbent is 45:55 to 65:35.

[0030] The packaging sheet is a crepe paper having a tensile breaking elongation of 20 to 35% in the front-to-back direction and a tensile breaking elongation of 4 to 8% in the width direction as specified in JIS P 8113:2006.

[0031] The thickness of the non-high compression portion is 5 to 13 mm.

[0032] The thickness of the high-compression portion is 30 to 50% of the thickness of the non-high-compression portion.

[0033] (Effect)

[0034] In recent years, in order to achieve the purpose of thinning the absorbent body, the mixing ratio of superabsorbent polymer particles is often increased. However, if the mixing ratio of superabsorbent polymer particles is increased, not only the shape maintenance of the high compression portion is reduced, but also the absorbent body is not easily deformed in the manner of being stretched by the deformation of the high compression portion in the vicinity of the high compression portion in the non-high compression portion. In addition, the superabsorbent polymer particles that absorb excrement and swell are closely attached to each other, which easily causes a phenomenon that hinders the diffusion of the excrement (gel blocking), so there is also a possibility of reduced diffusivity. Therefore, it is preferred to make the ratio of pulp fibers and superabsorbent polymer particles in the absorbent body within the range of this method, and perform compression formation of the high compression portion within the range of this method.

[0035] <Third Method>

[0036] In the absorbent article of the first or second aspect, the highly compressed portion is composed only of the highly compressed portion compressed in the thickness direction so as to be recessed from the surface of the absorbent member into the absorbent body.

[0037] (Effect)

[0038] In this absorption member, both the anti-re-seepage property and the diffusibility are improved. That is, as mentioned above, the high-compression portion is a high-density portion that is compressed by pressing (direct pressurization) and becomes roughly equal in thickness, and is the bottom of a pit that is sunken from the surface of the absorption member. On the other hand, the non-high-compression portion is a portion that is thicker and has a lower density than the high-compression portion, but even if it is a non-high-compression portion, the absorbent body will be deformed in a manner of being stretched by the deformation of the high-compression portion near the periphery of the high-compression portion, and as a result, the density increases as it approaches the high-compression portion. Therefore, the capillary phenomenon is strongly exhibited in the high-compression portion, and not only the liquid retention is higher than the surrounding area, but also the liquid is attracted toward the high-compression portion. Therefore, if the high-compression portion is arranged more densely than before, more excrement can be strongly retained in the part away from the skin, so it is not easy to produce re-seepage.

[0039] In addition, if the high compression parts are arranged more densely than before, the capillary phenomenon of the surrounding large number of high compression parts will produce an attractive force on the excrement absorbed into the absorbent body, so that the excrement is diffused over a wider range.

[0040] <Method 4>

[0041] The absorbent article according to any one of the first to third aspects, wherein:

[0042] In the arrangement region of the high compression portion, a virtual grid is defined, wherein first virtual straight lines along the first direction are repeatedly arranged at first intervals in a second direction inclined 80 to 90 degrees clockwise relative to the first virtual straight line when viewed from above, and second virtual straight lines along the second direction are repeatedly arranged at second intervals in the first direction, and

[0043] The smallest imaginary quadrilateral with the intersection of the first imaginary straight line and the second imaginary straight line as the vertex is defined. In this case,

[0044] The high compression portion includes: a first high compression portion arranged at the intersection of the first imaginary straight line and the second imaginary straight line; a second high compression portion arranged between adjacent first high compression portions of the first imaginary straight line and between adjacent first high compression portions of the second imaginary straight line; and a third high compression portion arranged at the intersection of the diagonals of the imaginary quadrilateral.

[0045] The first high compression portion forms a circle centered at the intersection of the first imaginary straight line and the second imaginary straight line.

[0046] The second high compression portion is an ellipse or a rounded rectangle having a center of gravity at the midpoint of each side of the imaginary quadrilateral and a major axis along each side.

[0047] The third high compression portion is an ellipse or a rounded rectangle having its center of gravity at the intersection of the diagonals of the imaginary quadrilateral and having a major axis along the front-to-back direction, or a circle centered at the intersection of the diagonals of the imaginary quadrilateral.

[0048] (Effect)

[0049] The shape and arrangement pattern of the high compression parts in the arrangement area of ​​the high compression parts can be appropriately determined. If the pattern is of this embodiment, the diffusibility of the second high compression part in the long axis direction (the first direction and the second direction) can be improved. Moreover, since there are both a portion where the non-high compression part is linearly continuous in the first direction and a portion where the non-high compression part is linearly continuous in the second direction, even if each high compression part is hardened, the absorbent as a whole can be easily deformed in a manner along the body surface.

[0050] <Method 5>

[0051] The absorbent article according to the fourth aspect, wherein:

[0052] The diameter of the first high compression portion is 1 to 4 mm.

[0053] The length of the major axis of the second high compression portion is 3 to 6 mm, and the length of the minor axis is equal to the diameter of the first high compression portion.

[0054] The third high compression portion has the same size and shape as the second high compression portion except that the long axis is oriented along the front-back direction.

[0055] The minimum interval between the adjacent first high compression portion and the adjacent second high compression portion is 1 to 2 mm.

[0056] (Effect)

[0057] When the high compression parts are arranged along the above-mentioned imaginary grid, the size of each high compression part can be appropriately determined. If it is within the scope of this method, it can not only improve the anti-damage, anti-rewetness and liquid diffusion properties of the packaging sheet, but also improve the deformability of the absorbent body, so it is preferred.

[0058] <Sixth Method>

[0059] An absorbent article as in the 4th or 5th embodiment, wherein the imaginary grid forms an oblique grid shape in which the first imaginary straight line is inclined 40° to 50° clockwise relative to the front-to-back direction when viewed from above, and the second imaginary straight line is inclined 40° to 50° counterclockwise relative to the front-to-back direction when viewed from above.

[0060] (Effect)

[0061] When the highly compressed portions are arranged along the virtual lattice as described above, it is preferable to arrange them in an oblique lattice as in the present embodiment because the absorbent body is excellent in not only easy deformability when worn but also liquid diffusibility.

[0062] <Seventh Method>

[0063] A method for producing an absorbent member comprising an absorbent body formed by mixing and aggregating pulp fibers and superabsorbent polymer particles, and a wrapping sheet made of crepe paper for wrapping the absorbent body.

[0064] The manufacturing method is characterized in that it comprises:

[0065] The first step is to form an absorbent body by mixing and aggregating the pulp fibers and the superabsorbent polymer particles.

[0066] A second step is to form a package body by packaging the entire absorbent body with a packaging sheet; and

[0067] In a third step, the package body is clamped between a support roller and a smooth roller, wherein the support roller has protrusions arranged at intervals on its outer peripheral surface, and the smooth roller has a cylindrical surface opposed to the support roller, and only the portion of the package body clamped between the plurality of protrusions of the support roller and the smooth roller is pressed.

[0068] When the arrangement of the front end faces of the above-mentioned protrusions in the above-mentioned supporting roller is unfolded on a plane, the diameter of the maximum inscribed circle inscribed in the outer shape of the front end faces of the above-mentioned protrusions in the arrangement area of ​​the above-mentioned front end faces is 2 to 5 mm, and the circumference of the outer shape of the front end faces of the above-mentioned protrusions is 1 to 2.5 times the circumference of the maximum inscribed circle inscribed in the outer shape of the front end faces of the above-mentioned protrusions, and the diameter of the maximum inscribed circle inscribed in the outer shape of the portion other than the above-mentioned front end faces in the arrangement area of ​​the above-mentioned front end faces is less than 6.5 mm.

[0069] (Effect)

[0070] The same effect as the first method is achieved.

[0071] Effects of the Invention

[0072] According to the present invention, there are advantages such as improved shape retention of the absorbent body and reduced damage to the packaging sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 It is a top view showing the inner surface of the pants-type disposable diaper in the unfolded state.

[0074] Figure 2 It is a top view showing the outer surface of the pants-type disposable diaper in the unfolded state.

[0075] Figure 3 yes Figure 1 2-2 cross-sectional view.

[0076] Figure 4 yes Figure 1 3-3 cross-sectional view.

[0077] Figure 5 In (a), Figure 1 4-4 cross-sectional view, and (b) is Figure 1 5-5 cross-sectional view.

[0078] Figure 6 It is a three-dimensional diagram of a shorts-type disposable diaper.

[0079] Figure 7 It is a plan view showing the outer surface of the inner body in the unfolded state together with the outline of the outer body.

[0080] Figure 8 It is a top view showing the surface of the absorbent body together with the outline of the packaging sheet.

[0081] Fig. 9 is a cross-sectional view of the absorbing member.

[0082] Fig.10 is a top view of the absorbing member.

[0083] Fig.11 It is a plan view showing an enlarged main portion of the surface of the absorbing member.

[0084] Fig.12 It is a top view showing another example of the absorber.

[0085] Fig.13 This is a cross-sectional view showing the absorbent member in a state before the absorbent body is packaged with a packaging sheet.

[0086] Fig.14 This is a cross-sectional view showing the absorbent member in a state after the absorbent body is packaged with a packaging sheet and before the highly compressed portion is formed.

[0087] Fig.15 is a cross-sectional view of other absorbing members.

[0088] Fig.16 It is a plan view showing an enlarged main portion of the surface of the absorbing member.

[0089] Fig.17 It is a plan view showing an enlarged main portion of the surface of the absorbing member.

[0090] Fig.18 It is a plan view showing an enlarged main portion of the surface of the absorbing member.

[0091] Fig.19 It is a plan view showing an enlarged main portion of the surface of the absorbing member.

[0092] Fig. 20 It is a plan view showing an enlarged main portion of the surface of the absorbing member.

[0093] Fig.21 It is a plan view showing an enlarged main portion of the surface of the absorbing member.

[0094] Fig. 22 is a schematic diagram illustrating a method of manufacturing an absorbing member.

[0095] Fig.23 This is a diagram for explaining a method for measuring the depth of a high compression portion. DETAILED DESCRIPTION

[0096] Hereinafter, as an example of an absorbent article, a shorts-type disposable diaper is described in detail with reference to the accompanying drawings. Each component adjacent in the thickness direction is fixed or joined in the same manner as a known diaper as required, except for the fixing portion or joining portion described below. The dotted portion in the cross-sectional view represents an adhesive such as a hot melt adhesive as the fixing means or joining means. The hot melt adhesive can be applied by a known method such as slit coating, continuous linear or dotted line droplet coating, spiral, Z-shaped, corrugated spray coating, or pattern coating (transfer of hot melt adhesive under relief printing). In the fixing portion of the elastic component, instead of this method or in combination with it, the hot melt adhesive can be applied to the outer peripheral surface of the elastic component to fix the elastic component to the adjacent component. As the hot melt adhesive, for example, there are adhesives of the type such as EVA, adhesive rubber (elastic system), polyolefin, polyester·polyamide, etc., which can be used without special limitation. As a fixing means or joining means for joining the components, means based on material welding such as heat sealing or ultrasonic sealing can also be used. In the portion where liquid permeability in the thickness direction is required, the components adjacent in the thickness direction are fixed or joined in an intermittent pattern. For example, in the case of such intermittent fixing or joining using a hot melt adhesive, intermittent pattern coating in a spiral, Z-shaped, corrugated shape, etc. can be appropriately adopted. In the case of coating in a range larger than the coating width using a single nozzle, intermittent pattern coating in a spiral, Z-shaped, corrugated shape, etc. can be performed with or without intervals in the width direction. As a joining means for joining the components, means based on material welding such as heat sealing or ultrasonic sealing can also be used.

[0097] In addition, as the nonwoven fabric in the following description, known nonwoven fabrics can be appropriately used according to the location and purpose. As the constituent fibers of the nonwoven fabric, in addition to synthetic fibers such as polyolefins such as polyethylene or polypropylene, polyesters, and polyamides (in addition to single-component fibers, composite fibers such as core-sheath fibers are also included), regenerated fibers such as rayon or cuprammonia fibers, natural fibers such as cotton, etc. can be selected without particular limitation, and they can also be mixed and used. In order to improve the softness of the nonwoven fabric, it is preferred that the constituent fibers are curled fibers. In addition, the constituent fibers of the nonwoven fabric can be hydrophilic fibers (including fibers made hydrophilic by using a hydrophilic agent), or can be hydrophobic fibers or water-repellent fibers (including fibers made water-repellent by using a water-repellent agent). In addition, nonwoven fabrics are generally classified into short fiber nonwoven fabrics, long fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, hot-rolled (hot air) nonwoven fabrics, needle-punched nonwoven fabrics, point-bonded nonwoven fabrics, laminated nonwoven fabrics (including SMS nonwoven fabrics and SMMS nonwoven fabrics having a meltblown layer sandwiched between spunbond layers), etc., according to the fiber length, sheet forming method, fiber bonding method, and layered structure. Any of these nonwoven fabrics can be used.

[0098] Figure 1 to Figure 6 An example of a shorts-type disposable diaper is shown. The shorts-type disposable diaper comprises: a rectangular front outer body 12F constituting the waistline portion on the front side and a rectangular rear outer body 12B constituting the waistline portion on the rear side; and an inner body 200 provided on the inner side of the outer bodies 12F and 12B in a manner extending from the front outer body 12F through the crotch portion M to the rear outer body 12B. The two side portions of the front outer body 12F and the two side portions of the rear outer body 12B are joined to form side seals 12A, whereby the opening formed by the front and rear ends of the outer bodies 12F and 12B becomes a waist opening WO for the wearer's waist to pass through, and the portions respectively surrounded by the lower edges of the outer bodies 12F and 12B and the side edges of the inner body 200 on both sides in the width direction of the inner body 200 become leg openings LO for the legs to pass through. The inner body 200 is a part that absorbs and holds excreta such as urine, and the outer bodies 12F and 12B are parts for supporting the inner body 200 to the body of the wearer. In addition, the symbol Y represents the full 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 part F to the edge of the waist opening WO of the back body part B), and the symbol X represents the full width of the diaper in the unfolded state.

[0099] The shorts-type disposable diaper has a waist region T defined as the front-to-back range with side seals 12A (the front-to-back range from the waist opening WO to the upper end of the leg openings LO); and a middle region L defined as the front-to-back range of the portion forming the leg openings LO (between the front-to-back region with side seals 12A of the front body portion F and the front-to-back region with side seals 12A of the back body portion B). The portion of the front outer body 12F and the back outer body 12B located in the waist region T, i.e., the front waist portion and the back waist portion can be conceptually divided into a "waist portion" W forming the edge portion of the waist opening, and a portion "waist lower portion" U below it. Usually, when there is a boundary in the waistline portion on the front side and the waistline portion on the back side where the elastic stress in the width direction WD changes (for example, the thickness and elongation of the elastic member change), the part closer to the waist opening WO side than the boundary closest to the waist opening WO side becomes the waist W. In the absence of such a boundary, the waist extension part 12E extending to the waist opening WO side from the absorbent body 56 or the inner body 200 becomes the waist W. The lengths of these in the front-to-back direction vary depending on the size of the product and can be appropriately determined. For example, the waist W can be 15 to 40 mm and the lower waist part U can be 65 to 120 mm. On the other hand, the side edges of the middle area L are narrowed into a U-shape or a curve shape in a manner along the leg circumference of the wearer, and this becomes a part for the wearer's legs to enter. As a result, the unfolded shorts-type disposable diaper forms a roughly hourglass shape as a whole.

[0100] (outer body)

[0101] The outer body 12F, 12B is composed of a rectangular front outer body 12F and a rectangular rear outer body 12B as shown in the example in the figure. The front outer body 12F is the part of the front body F that at least constitutes the waistline, and the rear outer body 12B is the part of the rear body B that at least constitutes the waistline. The front outer body 12F and the rear outer body 12B can be discontinuous on the crotch side and separated in the front-to-back direction LD (external two-part type), although not shown, but can also be continuous from the front body to the rear body (external one-piece type). The spacing distance 12d in the front-to-back direction of the outer two-part type can be, for example, about 40 to 60% of the total length Y. In the example in the figure, the lower edges of the front outer body 12F and the rear outer body 12B are straight lines along the width direction WD, but the lower edge of at least one of the front outer body 12F and the rear outer body 12B can also be curved along the leg circumference.

[0102] In the two-part outer shorts-type disposable diaper, the inner body 200 is exposed between the front outer body 12F and the rear outer body 12B. Therefore, in order to prevent the liquid-impermeable sheet 11 from being exposed on the back of the inner body 200, it is preferred to have a cover nonwoven fabric 13 on the back of the inner body 200 from between the front outer body 12F and the inner body 200 to between the rear outer body 12B and the inner body 200. The inner surface and the outer surface of the cover nonwoven fabric 13 can be bonded to the opposite surface by means of a hot-melt adhesive, respectively. The nonwoven fabric used in the cover nonwoven fabric 13 can be appropriately selected from the same material as the outer body 12F and 12B. In addition, although not shown in the figure, the outer body can also be continuous from the front body part F through the crotch to the back body part B. In this case, the outer body has not only a portion corresponding to the waist area T, but also a portion corresponding to the middle area L.

[0103] The front outer body 12F and the rear outer body 12B have a front waistline portion and a rear waistline portion constituting the waistline region T. Figure 1 and Figure 2 In the example shown, the dimensions of the front and rear exterior bodies 12F and 12B in the front-rear direction LD are equal, and the front and rear exterior bodies 12F and 12B do not have a portion corresponding to the middle area L, but may also be Figure 7 As shown, the dimension of the rear outer body 12B in the front-to-back direction is longer than that of the front outer body 12F, and the front outer body 12F does not have a portion corresponding to the middle region L, but the rear outer body 12B has a buttocks cover portion C extending from the waist region T to the middle region L. Although not shown, a groin cover portion extending from the waist region T to the middle region L may be provided in the front outer body 12F.

[0104] like Figure 4 and Figure 5As shown, the outer body 12F, 12B is formed by joining the outer side and inner side of the elastic components 16 to 19 described later with the outer side layer and the inner side layer adjacent to each other by means of hot melt adhesive, welding, etc. The outer side layer and the inner side layer can be formed by a single sheet material in addition to being formed by two sheets 12S, 12H as shown in the example in the figure. For example, in the latter case, the inner side layer and the outer side layer are formed by the inner side part and the outer side part of a sheet material folded back at the edge of the waist opening WO (which can also be the edge of the crotch side) in part or all of the outer body 12F, 12B. The example in the figure is an example of the former, and the sheet 12S forming the outer side layer of the lower waist part bypasses the waist opening WO side of the sheet 12H forming the inner side layer of the lower waist part and folds back to the inside thereof, and the folded part 12r extends in a manner that covers the end of the waist opening WO side of the inner body 200. On the other hand, in the waist region, the folded portion 12r serves as an inner sheet adjacent to the inner side of the elastic member.

[0105] In order to improve the fit to the wearer's waist, elastic components 16 to 19 are built into the outer bodies 12F and 12B to form an elastic region A2 that elastically expands and contracts in the width direction WD as the elastic components 16 to 19 expand and contract. In this elastic region A2, the outer bodies 12F and 12B contract in the natural length state as the elastic components contract, forming wrinkles or folds, and when stretched in the length direction of the elastic components, they can be stretched to a specified elongation without wrinkles and fully stretched. As elastic components 16 to 19, in addition to slender elastic components such as rubber threads (examples shown in the figure), known elastic components such as belt-shaped, mesh-shaped, and film-shaped can also be used without special limitations. As elastic components 16 to 19, synthetic rubber or natural rubber can be used.

[0106] The elastic components 16 to 19 shown in the figure are described in more detail. In the waist portion W of the outer body 12F, 12B, a plurality of waist elastic components 17 are installed at intervals in the front-to-back direction in a continuous manner throughout the entire width direction WD. In addition, one or more waist elastic components 17 arranged in the area adjacent to the lower waist portion U may overlap with the inner body 200, or may be arranged on both sides in the width direction thereof in addition to the central portion in the width direction overlapping with the inner body 200. As the waist elastic component 17, it is preferred to have a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber; in the case of natural rubber, a cross-sectional area of ​​0.05 to 1.5 mm 2 , especially 0.1~1.0mm 2The elastic cords (2 to 15, especially 4 to 10) are arranged at intervals of 2 to 12 mm, especially at intervals of 3 to 7 mm, and the elongation in the width direction WD of the waist W is preferably 150 to 400%, especially about 220 to 320%. In addition, the waist W does not need to use elastic members of the same thickness or the same elongation in the entire front-to-back direction LD, and for example, the thickness or elongation may be different in a part.

[0107] In addition, a plurality of waist elastic members 16 and 19 composed of elongated elastic members are installed at intervals in the front-to-back direction in the waist lower portion U of the outer body 12F and 12B to form a waist lower stretchable area (an area having waist lower elastic members 16 and 19). As waist lower elastic members 16 and 19, preferably, the thickness is 155 to 1880 dtex, especially about 470 to 1240 dtex (in the case of synthetic rubber; in the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm 2 , especially 0.1~1.0mm 2 The elastic cords (about 5 to 30) are arranged at intervals of 1 to 15 mm, especially 3 to 8 mm, and the elongation of the lower waist portion U in the width direction WD is preferably 200 to 350%, especially 240 to 300%. In addition, the lower waist portion U does not need to use elastic components of the same thickness or the same elongation in the entire front-to-back direction LD, and the thickness or elongation may be different in a part.

[0108] When elastic members 16 and 19 are provided in the front-back direction range of the absorbent body 56 as in the lower waist portion U of the figure, in order to prevent the absorbent body 56 from shrinking in the width direction WD in part or all of the absorbent body 56, as shown in the figure, Figure 4 , Figure 5 and Fig.12 As shown in the figure, it is preferred that the middle in the width direction including a part or all of the portion overlapping with the absorber 56 in the width direction WD is the non-elastic region A1, and the two sides in the width direction are the elastic regions A2 (the waist-lower elastic regions in the example shown in the figure). The width direction dimensions of the elastic regions A2 provided on the two sides in the width direction of the non-elastic region A1 are substantially constant in the front-back direction LD as shown in the example shown in the figure, but although not shown in the figure, they may also vary in the front-back direction LD. In addition, the width direction WD dimensions of the elastic regions A2 provided on the two sides in the width direction WD of the non-elastic region A1 may be substantially the same in the front body part F and the back body part B, but may also be different.

[0109] Such a stretchable area A2 and a non-stretchable area A1 can be constructed by installing elastic components 16 to 17, 19 between the inner sheet and the outer sheet, and then applying pressure and heating to the elastic components 16, 19 at one point in the middle of the width direction of the area to be the non-stretchable area A1 or substantially all over the area, or by cutting the elastic components 16, 19 to thinly cut the elastic components 16, 19 by cutting, so that the stretchability is retained in the stretchable area A2 while the stretchability is eliminated in the non-stretchable area A1. It should be noted that an unnecessary elastic component 18 that does not substantially contribute to the formation of stretchability will remain in the non-stretchable area A1.

[0110] The sheets 12S and 12H forming the inner sheet layer and the outer sheet layer may be used without particular limitation, but nonwoven fabrics are preferred. When nonwoven fabrics are used, the weight per unit area of ​​each sheet is preferably 10 to 30 g / m 2 about.

[0111] The elastic components 16 to 19 can be fixed to the outer body 12F, 12B by a known method. In addition, the inner sheet layer and the outer sheet layer can also be joined to each other by a known method. For example, in the portion of the outer body 12F, 12B having the elastic components 16 to 19, by using a coating means such as a coating gun, a SureWrap nozzle, etc., only the outer peripheral surface of the elastic components 16 to 19 is coated with a hot melt adhesive HM and sandwiched between the inner sheet layer and the outer sheet layer, and the elastic components 16 to 19 can be fixed to the inner sheet layer and the outer sheet layer, and the inner sheet layer and the outer sheet layer can be fixed only by the hot melt adhesive HM coated on the outer peripheral surface of the elastic components 16 to 19.

[0112] (Inner body joint)

[0113] The inner body 200 can be joined to the outer body 12F, 12B by means of a joining method based on material fusion such as heat sealing or ultrasonic sealing, or by a hot melt adhesive. In the example shown in the figure, the inner body 200 is fixed to the inner surface of the outer body 12F, 12B by means of a hot melt adhesive applied to the back surface of the inner body 200, that is, the back surface of the liquid-impermeable sheet 11 in this case and the root portion 65 of the standing gather portion 60. The inner body joint 20 that joins the inner body 200 to the outer body 12F, 12B can be as shown in FIG. Figure 2 As shown, the plurality of inner body 200 is provided in substantially the entire overlapping region, but may be provided in a portion other than both end portions in the width direction of the inner body 200, for example.

[0114] (inner body)

[0115] The inner body 200 may have any shape, but in the example shown in the figure, it is a rectangle having long sides along the front-rear direction LD. Figure 3 to Figure 5As shown, the inner body 200 comprises a top sheet 30 constituting the body side, a liquid-impermeable sheet 11, and an absorbent member 50 interposed therebetween. Reference numeral 40 denotes an intermediate sheet (auxiliary sheet) disposed between the top sheet 30 and the absorbent member 50 in order to rapidly transfer the liquid having passed through the top sheet 30 to the absorbent member 50, and reference numeral 60 denotes a standing pleat portion 60 extending from both sides of the inner body 200 in a manner in contact with the leg circumference of the wearer in order to prevent excrement from leaking to both sides of the inner body 200.

[0116] (Top sheet)

[0117] The top sheet 30 has the property of making liquid permeable, for example, can illustrate porous or non-porous nonwoven fabrics, porous plastic sheets etc. In addition, the top sheet 30 can be composed of one sheet, and can also be composed of the laminated sheet obtained by laminating more than two sheets. Similarly, the top sheet 30 can be composed of one sheet in the planar direction, and can also be composed of more than two sheets.

[0118] The both side portions of the top sheet 30 may be folded back toward the back side at the side edges of the absorbent member 50 , or may extend to the sides of the side edges of the absorbent member 50 without being folded back.

[0119] Top sheet 30 is for the purpose of preventing the position deviation of the parts on the back side, and it is expected to be fixed on the parts adjacent to the back side by the joining means or hot melt adhesive based on material welding such as heat seal and ultrasonic sealing. In the example of the figure, top sheet 30 is fixed on the surface of the intermediate sheet 40 and the surface of the part on the surface side of the absorbent 56 in the packaging sheet 58 by the hot melt adhesive applied on its back side.

[0120] (Middle piece)

[0121] In order to quickly transfer the liquid that has passed through the top sheet 30 to the absorbent 56, an intermediate sheet (also referred to as an auxiliary sheet) 40 having a faster liquid permeation rate than the top sheet 30 may be provided. The intermediate sheet 40 is used to quickly transfer the liquid to the absorbent 56, thereby improving the absorption performance based on the absorbent 56 and reducing the back permeation from the absorbent 56. The intermediate sheet 40 may also be omitted.

[0122] As the middle sheet 40, the same material as the top sheet 30, spunlace nonwoven fabric, spunbond nonwoven fabric, SMS nonwoven fabric, pulp nonwoven fabric, mixed sheet of pulp and rayon, point-bonded nonwoven fabric or crepe paper can be exemplified. Hot air nonwoven fabric is particularly preferred because it is fluffy. In hot air nonwoven fabric, it is preferred to use a composite fiber with a core-sheath structure. In this case, the resin used in the core can be polypropylene (PP), but polyester (PET) with high rigidity is preferred. The weight per unit area is preferably 17 to 80 g / m 2 , more preferably 25 to 60 g / m 2The thickness of the raw material fiber of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the nonwoven fabric bulky, it is also preferable to use mixed fibers of eccentric fibers whose core is not located at the center, hollow fibers, and eccentric and hollow fibers as all or part of the raw material fibers.

[0123] The middle piece 40 of the illustrated example is shorter than the width of the absorbent body 56 and is arranged in the center, but it can also be arranged over the entire width. The front-to-back length of the middle piece 40 can be the same as the full length of the diaper, can be the same as the length of the absorbent member 50, and can also be within a shorter length range centered on the area receiving the liquid.

[0124] The intermediate sheet 40 is fixed to the adjacent components on the back side by a joining means based on material fusion such as heat sealing and ultrasonic sealing, or a hot melt adhesive for the purpose of preventing the components from being displaced relative to the back side. In the example shown in the figure, the intermediate sheet 40 is fixed to the surface of the portion located on the front side of the absorbent body 56 in the packaging sheet 58 by a hot melt adhesive applied on the back side thereof.

[0125] (Liquid-impermeable sheet)

[0126] The material of the liquid-impermeable sheet 11 is not particularly limited, and examples thereof include a plastic film made of a polyolefin resin such as polyethylene or polypropylene, a laminated nonwoven fabric formed by providing a plastic film on the surface of a nonwoven fabric, and a laminated sheet formed by overlapping and bonding a nonwoven fabric on a plastic film. In the liquid-impermeable sheet 11, a material having liquid-impermeability and moisture-permeability is preferably used, which is preferably used from the perspective of preventing stuffiness. As a moisture-permeable plastic film, a microporous plastic film obtained by kneading an inorganic filler in a polyolefin resin such as polyethylene or polypropylene, and then stretching it in a uniaxial or biaxial direction after forming a sheet can be widely used. In addition, nonwoven fabrics using micro denier fibers; nonwoven fabrics whose leak-proof properties are enhanced by reducing the gaps between fibers by applying heat or pressure; and sheets that are made liquid-impermeable without using plastic films by methods such as coating with superabsorbent resins or hydrophobic resins or water repellents can also be used as the liquid-impermeable sheet 11. However, in order to obtain sufficient bonding strength when bonding to the cover nonwoven fabric 13 described later by means of hot-melt adhesives, it is preferably used a resin film.

[0127] In addition to being set to a width that fits into the back side of the absorbent member 50 as shown in the figure, the liquid-impermeable sheet 11 may also extend to both sides of the side of the top sheet 30 of the absorbent member 50 by bypassing both sides of the absorbent member 50 to improve leakage prevention. The width of the extended portion is preferably about 5 to 20 mm on both sides.

[0128] (Absorbing member)

[0129] The absorption member 50 has an absorber 56 and a wrapping sheet 58 that wraps the entire absorber 56. The absorption member 50 has a crotch portion M and portions extending to the front and rear sides of the crotch portion M.

[0130] (Absorber)

[0131] The absorbent body 56 is formed by mixing and aggregating pulp fibers and superabsorbent polymer particles, and the pulp fibers and superabsorbent polymer particles are substantially uniformly present throughout the entire absorbent body 56. The basis weight of the pulp fibers may be, for example, 100 to 450 g / m 2 The absorbent 56 is preferably an absorbent obtained by mixing and aggregating only pulp fibers and superabsorbent polymer particles, but may contain trace amounts of additives such as deodorants and fragrances as long as they do not hinder the improvement of the anti-rewetting property and diffusibility described later.

[0132] The superabsorbent polymer particles include "powders" in addition to "particles". As the superabsorbent polymer particles, the superabsorbent polymer particles used in such disposable diapers can be used directly, for example, preferably particles whose proportion of particles remaining on the sieve after sieving (vibrating for 5 minutes) using a 500 μm standard sieve (JIS Z 8801-1:2006) is 30% by weight or less, and preferably particles whose proportion of particles remaining on the sieve after sieving (vibrating for 5 minutes) using a 180 μm standard sieve (JIS Z 8801-1:2006) is 60% by weight or more.

[0133] The material of the superabsorbent polymer particles can be used without particular limitation, but preferably a material having a water absorption of 40 g / g or more. The superabsorbent polymer particles include starch-based, cellulose-based, synthetic polymer-based superabsorbent polymer particles, and superabsorbent polymer particles such as starch-acrylic acid (salt) graft copolymers, starch-acrylonitrile copolymer saponification products, sodium carboxymethyl cellulose crosslinked products, and acrylic acid (salt) polymers can be used. The shape of the superabsorbent polymer particles is preferably a commonly used powdery granular shape, but other shapes can also be used.

[0134] As the superabsorbent polymer particles, it is preferable to use superabsorbent polymer particles having a water absorption rate of 70 seconds or less, particularly 40 seconds or less. If the water absorption rate is too slow, so-called back permeation (liquid supplied to the absorbent body 56 returns to the outside of the absorbent body 56) is likely to occur.

[0135] In addition, as the superabsorbent polymer particles, it is preferable to use superabsorbent polymer particles having a gel strength of not less than 1000 Pa. Thereby, even when the absorbent body 56 is formed into a bulky state, it is possible to effectively suppress the sticky feeling after liquid absorption.

[0136] The basis weight of the superabsorbent polymer particles can be appropriately determined according to the absorption amount required for the use of the absorbent body 56. Therefore, it cannot be generalized, but it can be 50 to 350 g / m 2 If the unit area weight of the polymer is less than 50g / m 2 If it exceeds 350g / m 2 , the effect reaches saturation.

[0137] The ratio of the fibers and the superabsorbent polymer particles in the absorbent body 56 is not particularly limited, and for example, the ratio of fibers to superabsorbent polymer particles may be 40:60 to 65:35 in terms of weight ratio.

[0138] The thickness 56t of the absorber 56 is not particularly limited, and may be 5 to 13 mm.

[0139] The absorber 56 may be extended to the front and rear sides of the crotch portion M in a manner including the crotch portion M. In the case of a shorts-type disposable diaper as in this example, the absorber 56 preferably extends to the peripheral edge of the inner body 200 or its vicinity in the front-back direction LD and the width direction WD. It should be noted that the symbol 56X represents the full width of the absorber 56.

[0140] In the case where the absorption amount of the crotch portion M is easily ensured, the absorbent body 56 is preferably as follows Figure 8 As shown in the example, it is roughly rectangular in shape. Fig.12 As shown in the example of (a), in order to improve the fit of the crotch M, the width of the absorbent body 56 in the crotch M may be narrower than the front and rear sides thereof to form a narrowed shape. In this case, in order to easily ensure the absorption amount of the crotch M, it is preferred that the width n1 of the narrowest part of the absorbent body 56 in the crotch M is at least 0.85 times the full width 56X of the absorbent body 56.

[0141] It should be noted that, regarding the crotch portion M, when the absorbent body 56 has a narrowing portion 56n described later, it refers to the range of the front-to-back direction LD having the narrowing portion 56n; when the absorbent body 56 does not have the narrowing portion 56n, but the outer shape of the diaper in the unfolded state has the narrowing portion as shown in the example, it refers to the range of the outer shape of the diaper having the narrowing portion in the front-to-back direction LD (in the case of the example shown, it refers to the front outer body 12F and the rear outer body 12B); when there is no narrowing portion, it refers to the portion located in the center of the front-to-back direction LD and the dimension of the front-to-back direction LD is 20 to 30% of the total length of the product. The portions extending from the crotch portion M to the front and rear sides are referred to as the front side portion and the rear side portion.

[0142] (Low area weight)

[0143] The absorbent body 56 may be Figures 1 to 4As shown in the example, there are elongated low-weight-per-unit area portions 56L extending in the front-to-back direction LD on both sides of the crotch portion M in the width direction WD. Although not shown in the figure, the low-weight-per-unit area portion 56L may be omitted. The low-weight-per-unit area portion 56L refers to a portion with a small weight per unit area, and does not include a portion that is only compressed in the thickness direction TD and does not change the weight per unit area, such as the high compression portion 51 described later. The low-weight-per-unit area portion 56L may also be set as a slit running through the thickness direction TD, but it is preferred to be a concave portion with a small amount of pulp fibers and superabsorbent polymer particles as shown in the example, because it is easy to ensure the absorption amount. The concave portion may be formed on the surface of the absorbent body 56 or on the back. By providing such a low-weight-per-unit area portion 56L in the absorbent body 56, the bending of the absorbent body 56 along the low-weight-per-unit area portion 56L can be promoted, and the fit of the absorption member 50 of the crotch portion M can be improved. The total unit area weight of the pulp fibers and super absorbent polymer particles in the low unit area weight portion 56L only needs to be less than the total unit area weight of the pulp fibers and super absorbent polymer particles in the portion other than the low unit area weight portion 56L. For example, it can be 0.1 to 0.5 times the total unit area weight of the pulp fibers and super absorbent polymer particles in the portion other than the low unit area weight portion 56L.

[0144] The low unit area weight portion 56L only needs to be an elongated shape extending in the front-to-back direction LD, and may extend in a straight line in the front-to-back direction LD, or may be curved in a manner that it is located laterally as it moves toward both sides of the front-to-back direction LD as shown in the example in the figure. In addition, the front and rear ends of the low unit area weight portion 56L may be of appropriate shapes, for example, in addition to the Fig.12 In addition to being a straight line as in the example shown in (a) of FIG. Figure 8 As shown in the example, the shape of the low unit weight portion 56L is a curved bulge (semicircular arc shape, etc.). Although not shown in the figure, the corners of the two end portions can be rounded and the middle portion can be made straight. The width m1 of the low unit weight portion 56L can be appropriately determined, for example, it can be 0.04 to 0.1 times the width n1 of the narrowest part of the absorbent body 56 in the crotch M (in the case of a rectangle, it refers to the full width 56X). The width m1 of the low unit weight portion 56L can be constant in its length direction or it can change. The size and configuration of the front-to-back direction LD of the low unit weight portion 56L can be appropriately determined. For example, the size m2 of the front-to-back direction LD of the low unit weight portion 56L can be 50 to 120% of the size of the front-to-back direction LD of the crotch M, and more preferably 50 to 80%. In addition, the low unit weight portion 56L can be retracted within the range of the crotch M, or it can extend to the front, rear, or front and rear sides of the crotch M.

[0145] The low-weight portion 56L has the following Figure 8In addition to providing one on each side of the crotch portion M in the width direction WD and one in the center in the width direction WD as shown in the figure, it is also possible to provide one on each side of the crotch portion M in the width direction WD as shown in the figure. Fig.12 As shown in (a), only one is provided in the center, or as shown in Fig.12 As shown in (b), only one is provided on each side of the crotch portion M in the width direction WD.

[0146] (Packaging Sheet)

[0147] As the packaging sheet 58, crepe paper, nonwoven fabric, polyethylene laminated nonwoven fabric, sheet with small holes, etc. can be used. The nonwoven fabric used in the packaging sheet 58 is not particularly limited, and SMS nonwoven fabric, SSMMS nonwoven fabric, etc., in which at least one meltblown layer is sandwiched by a pair of spunbond layers on the front and back, can be appropriately used. The material of the fiber is not particularly limited, for example, polypropylene fiber, polyethylene / polypropylene bicomponent fiber, etc. can be used. The weight per unit area of ​​the packaging sheet 58 can be appropriately determined, preferably 5 to 40 g / m 2 , particularly preferably 10 to 30 g / m 2 .

[0148] The crepe paper used in the packaging sheet is not particularly limited, but the weight per unit area is preferably 13 to 20 g / m 2 , particularly preferably 14 to 18 g / m 2 In addition, the air permeability of crepe paper measured in accordance with JIS P 8117:2009 "Paper and paperboard - Test methods for air permeability and air resistance (intermediate region) - Gurley method" is preferably 1 to 15 seconds.

[0149] The crepe paper used for the packaging sheet 58 is preferably a crepe paper having a tensile breaking elongation of 20 to 35% in the front-rear direction LD and a tensile breaking elongation of 4 to 8% (particularly 5 to 7%) in the width direction WD as specified in JIS P 8113:2006.

[0150] The packaging structure of the packaging sheet 58 can be appropriately determined. From the perspectives of ease of manufacturing and preventing leakage of highly absorbent polymer particles from the front and rear edges, it is preferably wound into a tube in a manner to surround the surface, back and two side surfaces of the absorbent body 56 as shown in the example shown in the figure, and the front and rear edges are extended from the front and rear of the absorbent body 56, and the overlapping parts of the winding and the overlapping parts of the front and rear extended parts are joined by hot melt adhesives, material welding or other joining means.

[0151] (High compression part)

[0152] In the absorption member 50, as Figure 3 , Figure 4 , Figures 9 to 11As shown, the high compression parts 51 compressed in the thickness direction TD in a manner of being recessed from the surface of the absorption member 50 into the absorbent body 56 are arranged at intervals. In addition, the portion other than the high compression parts 51 in the arrangement area of ​​the high compression parts 51 (a rectangular area composed of sides along the front-to-back direction LD and the width direction WD, and circumscribing all the arranged high compression parts 51) becomes a non-high compression part 52 that is thicker than the high compression parts 51 and has a lower density. The high compression parts 51 are high-density parts that are compressed by pressing (direct pressure) and have a substantially equal thickness, and are the bottom of the recess. On the other hand, the non-high compression parts 52 are parts that are thicker than the high compression parts 51 and have a lower density, but even in the non-high compression parts 52, the absorbent body 56 is deformed in a manner of being stretched by the deformation of the high compression parts 51 near the periphery of the high compression parts 51, and as a result, the density increases as it approaches the high compression parts 51. The non-highly compressed portion 52 only needs to be thicker and have a lower density than the highly compressed portion 51, and a part or the whole may be compressed in the thickness direction TD at the same time, before, or after the formation of the highly compressed portion 51. The non-highly compressed portion 52 preferably does not have pits on either or both of the surface and the back surface of the absorbing member 50, but may have pits on either or both of the surface and the back surface of the absorbing member 50 as long as it is thicker and has a lower density than the highly compressed portion 51.

[0153] In addition to being provided over the entire front-to-back direction and the width direction of the absorption member 50 (i.e., the entire surface of the absorption member 50 becomes the arrangement area of ​​the high compression portion 51), the high compression portion 51 may be provided only in a part of the front-to-back direction or a part of the width direction of the absorption member 50. For example, although not shown in the figure, the high compression portion 51 may be provided only in the middle area of ​​the front-to-back direction LD including the crotch portion M, or conversely, the high compression portion 51 may not be provided in the middle area of ​​the front-to-back direction LD including the crotch portion M, but may be provided only in the areas on both sides thereof. In addition, the high compression portion 51 in the illustrated example is not recessed from the surface of the sheet located on the front side of the absorption member (in the case of the illustrated example, the top sheet 30 and the middle sheet 40) into the absorbent body 56, but may be pressed in a manner such that it is recessed from the sheet located on the front side of the absorption member into the absorbent body 56, resulting in it being recessed from the surface of the absorption member 50 into the absorbent body 56.

[0154] When the packaging sheet 58 is a crepe paper having the above-mentioned tensile elongation at break, if the size of the high compression portion 51 is too small, or the shape of the high compression portion 51 is too long in one direction, or has an overly complicated outer shape, the crepe paper may be damaged at the edge of the high compression portion 51 or between adjacent high compression portions 51 when the high compression portion 51 is formed. In addition, since the high compression portion 51 is a hard portion, when the size of the high compression portion 51 is too large, there is a possibility that the softness of the absorbent body 56 as a whole is insufficient, or a skin touch (foreign body feeling) such as foreign matter is mixed into the absorbent body 56 is generated. Therefore, it is preferred that the high compression portion 51 has an outer shape without an inflection point and a bending point. In addition, the diameter of the maximum inscribed circle 53 inscribed in the outer shape of the high compression portion 51 is preferably 2 to 5 mm, and more preferably 2.5 to 3.5 mm. In addition, the circumference of the outer shape of the high compression portion 51 is preferably 1.0 to 2.5 times, more preferably 1.0 to 2.0 times, and particularly preferably 1.0 to 1.6 times the circumference of the maximum inscribed circle 53 inscribed in the outer shape of the high compression portion 51. On the other hand, the diameter of the maximum inscribed circle 54 inscribed in the outer shape of the non-high compression portion 52 is preferably 6.5 mm or less, more preferably 6 mm or less, and particularly preferably 5 mm or less. In addition, the lower limit of the diameter of the maximum inscribed circle 54 inscribed in the outer shape of the non-high compression portion 52 is preferably 4 mm.

[0155] The high compression portion 51 is a high-density portion where the absorption member 50 is compressed in the thickness direction TD by pressing (direct pressure) and the thickness becomes roughly equal. It is the bottom of a pit that is sunken from the surface or back of the absorption member 50. On the other hand, the non-high compression portion 52 is a portion that is thicker and has a lower density than the high compression portion 51, but even in the non-high compression portion 52, the absorbent body 56 will be deformed in a manner stretched by the deformation of the high compression portion 51 near the high compression portion 51, and as a result, the thickness decreases and the density increases as it approaches the high compression portion 51. Therefore, if the high compression portion 51 of a certain size is arranged more densely than before, the area where the thickness of the non-high compression portion 52 is reduced increases. And as a result, the strain generated in the packaging sheet 58 when the high compression portion 51 is formed is reduced (the tensile stress applied is weakened), and the packaging sheet 58 is not easily damaged. In addition, even if it is a non-high compression portion 52, the absorbent body 56 will be deformed in a manner stretched by the deformation of the high compression portion 51 near the high compression portion 51, and as a result, it will also bring the advantage of thinning the absorbent body 56 compared to the case where the high compression portion 51 does not exist. From these aspects, it is important that the high compression portion 51 has a shape that can contain a sufficiently large circle. In addition, it is also important that the shape of the high compression portion 51 is not too long in one direction or does not have an overly complex shape. In addition, it is also important that the diameter of the maximum inscribed circle 54 inscribed in the outer shape of the non-high compression portion 52 is small so that the configuration of the high compression portion 51 does not become sparse (the non-high compression portion 52 does not continue for a long time in all directions).

[0156] In addition, as long as it is within the above-mentioned range, the area ratio of the high compression portion 51 in the arrangement area of ​​the high compression portion 51 (the sum of the areas of the high compression portion 51 / the area of ​​the arrangement area of ​​the high compression portion 51) can be appropriately determined, and under normal circumstances it is preferably 10 to 35%, and more preferably 20 to 35%.

[0157] As an example, the area of ​​each high compression portion 51 may be 3 to 15 mm. 2 In addition, the major diameter d1 (the length of the long side of the minimum circumscribed rectangle) of each high compression portion 51 can be about 4 to 9 mm, and the minor diameter d2 (the length of the short side of the minimum circumscribed rectangle) can be about 2 to 5 mm. When the lengths of the four sides of the minimum circumscribed rectangle of each high compression portion 51 are equal, the length d3 of the side can be about 2 to 5 mm. In addition, the shortest distance d4 to the nearest other high compression portion 51 can be about 1.5 to 3.5 mm.

[0158] The outer shape of the high compression portion 51 is not particularly limited. A shape without inflection points or bending points, such as a circle, an ellipse, or a rounded rectangle (including a shape in which any two sides are not straight lines but are semicircles) is preferred. A triangle, cloud, X-shape, V-shape, U-shape, etc. are not preferred.

[0159] In recent years, in order to achieve the purpose of thinning the absorbent body 56, the mixing ratio of superabsorbent polymer particles is often increased. However, if the mixing ratio of superabsorbent polymer particles is increased, not only will the shape retention of the high compression portion 51 be reduced, but also the absorbent body 56 will not be easily deformed in the vicinity of the high compression portion 51 in the non-high compression portion 52 in a manner that is stretched by the deformation of the high compression portion 51. In addition, the superabsorbent polymer particles that absorb excrement and swell are closely attached to each other, which is likely to cause a phenomenon that hinders the diffusion of excrement (gel blocking), so there is also a possibility of reduced diffusivity. Therefore, the unit area weight of the pulp fiber in the absorbent body 56 is 100 to 500 g / m 2 In the case of , it is preferred that the weight ratio of pulp fibers to superabsorbent polymer particles in the absorbent body 56 be 45:55 to 65:35.

[0160] The thickness 50t of the absorbent member 50 and the thickness 51t of the highly compressed portion 51 can be appropriately determined. However, if the compression is insufficient, it may be difficult to improve the low repermeability and diffusibility. Therefore, when the above-mentioned range of the basis weight of the pulp fiber and the range of the ratio of the pulp fiber to the superabsorbent polymer particles are adopted, the thickness 50t of the absorbent member 50 (the thickness of the non-highly compressed portion 52) is preferably 5 to 13 mm. In this case, the thickness 51t of the highly compressed portion 51 (the minimum value in the case of thickness variation) can be appropriately determined, and in general, it is preferably 30 to 50% of the thickness 50t of the absorbent member 50.

[0161] Although not shown in the figure, the high compression portion 51 can also be compressed in the thickness direction TD in a manner that is recessed from the back side of the absorption member 50 into the absorbent body 56. In this case, a pit is formed on the back side of the absorption member 50. However, if the high compression portion 51 is compressed in the thickness direction TD in a manner that is recessed from the surface of the absorption member 50 into the absorbent body 56 as shown in the example in the figure, both the anti-rewetting property and the diffusibility can be improved. That is, as described above, the high compression portion 51 is a high-density portion that is compressed by pressing (direct pressure) and has a substantially equal thickness, and is the bottom of the pit recessed from the surface of the absorption member 50. On the other hand, the non-high compression portion 52 is a portion that is thicker and has a lower density than the high compression portion 51, but even in the non-high compression portion 52, the absorbent body 56 will be deformed in a manner that is stretched by the deformation of the high compression portion 51 near the periphery of the high compression portion 51, and as a result, the density increases as it approaches the high compression portion 51. Therefore, the capillary phenomenon is strongly exhibited in the high compression part 51, and not only the liquid retention is higher than the surrounding, but also the liquid is attracted toward the high compression part 51. Therefore, if the high compression part 51 is arranged more densely than before, more excrement can be strongly retained in the part away from the skin, so it is not easy to cause back seepage. In addition, if the high compression part 51 is arranged more densely than before, the capillary phenomenon of the surrounding plurality of high compression parts 51 generates an attraction effect on the excrement absorbed in the absorbent 56, so that the excrement is diffused to a wider range.

[0162] The high compression portions 51 may be arranged in a suitable regular or irregular pattern. For example, the high compression portions 51 may be exemplified as follows: Fig.17 As shown in FIG. 1 , the high compression portion 51 is arranged in a grid pattern in a dotted line shape; Fig.18 and Fig.19 As shown, the dot-shaped high compression parts 51 are arranged in a staggered or row-shaped pattern, etc. In addition, although not shown, the high compression parts extending in a straight line may be arranged in a grid-shaped pattern.

[0163] A preferred pattern of the high compression portion 51 is Fig.11 and Fig.16Example shown. In this example, an imaginary grid is defined in the arrangement area of ​​the high compression portion 51, and the imaginary grid is formed by repeatedly arranging a first imaginary straight line 81 along the first direction in a second direction inclined 80 to 90 degrees clockwise relative to the first imaginary straight line 81 when viewed from above at a first interval 81d, and repeatedly arranging a second imaginary straight line 82 along the second direction in the first direction at a second interval 82d, and defining a minimum imaginary quadrilateral 83 with the intersection of the first imaginary straight line 81 and the second imaginary straight line 82 as a vertex. At this time, the high compression portion 51 includes: a first high compression portion 51a arranged at the intersection position of the first imaginary straight line 81 and the second imaginary straight line 82; a second high compression portion 51b respectively arranged between adjacent first high compression portions 51a of the first imaginary straight line 81 and between adjacent first high compression portions 51a of the second imaginary straight line 82; and a third high compression portion 51c arranged at the intersection position of the diagonals of the imaginary quadrilateral. In addition, the first high compression portion 51a is formed into a circle centered at the intersection of the first imaginary straight line 81 and the second imaginary straight line 82, the second high compression portion 51b is formed into a rounded rectangle (or an ellipse) having a center of gravity at the midpoint of each side of the imaginary quadrilateral and having a long axis along each side, and the third high compression portion 51c is formed into a rounded rectangle (or an ellipse or a circle centered at the intersection of the diagonals of the imaginary quadrilateral) having a center of gravity at the intersection of the diagonals of the imaginary quadrilateral and having a long axis along the front-back direction LD. By using this pattern, the diffusibility of the second high compression portion 51b in the long axis direction (the first direction and the second direction) can be improved, and since there are both a portion where the non-high compression portion 52 is linearly continuous in the first direction and a portion where the non-high compression portion 52 is linearly continuous in the second direction, even if each high compression portion 51 is hardened, the absorbent body 56 as a whole is easy to deform in a manner along the body surface.

[0164] Along the Fig.11 and Fig.16In the case of the illustrated example of the virtual grid arrangement of the high compression portion 51, the size of each high compression portion 51 can be appropriately determined, but if the diameter of the first high compression portion 51a is 1 to 4 mm; the length of the major axis of the second high compression portion 51b is 3 to 6 mm, and the length of the minor axis is equal to the diameter of the first high compression portion 51a; the third high compression portion 51c has the same size and shape as the second high compression portion 51b except that the major axis is oriented along the front-to-back direction LD; and the shortest distance d4 between the adjacent first high compression portion 51a and the second high compression portion 51b is 1 to 2 mm, it is preferred that not only the anti-rewetting property and liquid diffusivity are improved, but also the deformability of the absorbent body 56 can be improved. The first interval 81d: the second interval 82d is preferably in the range of 0.9:1.1 to 1.1:0.9, and it is particularly preferred that the first interval 81d and the second interval 82d are equal. The first interval 81d and the second interval 82d can be about 10 to 14 mm.

[0165] In addition, if the above-mentioned imaginary lattice forms an oblique lattice shape in which the first imaginary straight line 81 is inclined 40 to 50 degrees clockwise relative to the front-to-back direction LD when viewed from above, and the second imaginary straight line 82 is inclined 40 to 50 degrees counterclockwise relative to the front-to-back direction LD when viewed from above, not only the deformability of the absorbent body 56 when worn is excellent, but also the diffusibility of the liquid is excellent, and therefore it is preferred.

[0166] The absorbent member can be manufactured by a known method. For example, the absorbent member 50 having the high compression portion 51 can be manufactured by performing the following steps: a first step of forming an absorbent body 56 in which pulp fibers and high absorbent polymer particles are mixed and aggregated; a second step of forming a package 50P in which the absorbent body 56 is packaged with a packaging sheet 58; and a third step of forming a package 50P in which the absorbent body 56 is packaged with a packaging sheet 58. Fig. 22 As shown, the package 50P is passed between a support roller 90 having a plurality of protrusions 91 arranged at intervals in the same pattern as the high compression portion 51 on the outer peripheral surface and a smooth roller 92 having a cylindrical surface (without the protrusions 91) opposed to the support roller 90, and the high compression portion 51 is formed by pressing the portion of the package 50P sandwiched between the plurality of protrusions 91 of the support roller 90 and the smooth roller 92. The high compression portion 51 may be formed while heating either or both of the support roller 90 and the smooth roller 92, or may be formed without heating. In the third step, only the portion of the package 50P sandwiched between the plurality of protrusions 91 of the support roller 90 and the smooth roller 92 may be pressed, or the portion sandwiched between the plurality of protrusions 91 of the support roller 90 and the smooth roller 92 may be pressed to the deepest extent while pressing the entire package 50P.

[0167] The size, shape, and arrangement of the front end surface of the protrusion 91 may be the same as those of the high compression portion 51. The gap between the support roller 90 and the smooth roller 92 (the minimum interval of the pressing position) may be less than the thickness of the high compression portion 51, and may be 0.5 to 1.5 mm as an example. The pressure when the high compression portion 51 is formed by the support roller 90 and the smooth roller 92 may be appropriately determined, and may be 0.2 to 0.4 MPa as an example.

[0168] If the packaging sheet 58 is constructed in such a way that the MD direction is along the front-to-back direction LD, it is easy to manufacture and is therefore preferred. In this case, the fiber orientation of the packaging sheet 58 is in the front-to-back direction LD. Since the dry tensile strength in the width direction WD is significantly weaker than the dry tensile strength in the front-to-back direction LD, if the dimension of the high compression portion 51 in the front-to-back direction LD is longer than twice, especially three times, the dimension of the high compression portion 51 in the width direction WD (that is, the high compression portion 51 is a shape that is longer in the front-to-back direction LD), the packaging sheet 58 is easily damaged on both sides of the width direction WD. Therefore, if the dimension of the high compression portion 51 in the front-to-back direction LD is less than twice, especially less than 1.5 times, the dimension of the high compression portion 51 in the width direction WD, the packaging sheet 58 is not easily damaged and is therefore preferred.

[0169] In addition, if Fig.15 As shown, if the packaging sheet 58 has: a surface portion 58s, which is located on the surface side of the absorbent body 56; a first back portion 58a, which is a portion continuous from the surface portion 58s, bypassing one side edge of the absorbent body 56 to reach the back side of the absorbent body 56; and a second back portion 58b, which is a portion continuous from the surface portion 58s, bypassing the other side edge of the absorbent body 56 to reach the back side of the absorbent body 56, the first back portion 58a and the second back portion 58b have a stacked portion 58W that overlaps with each other, and the high compression portion 51 is entirely formed in the stacked portion 58W, then the crepe paper on the forming surface of the high compression portion 51 becomes a double layer, the strength is improved, and it is not easy to be damaged when the high compression portion 51 is formed, so it is preferred.

[0170] The shape maintenance of the absorbent member 50 by the high compression portion 51 depends on the maintenance of the high compression portion 51 itself, and the maintenance of the high compression portion 51 itself depends on the bonding strength between the packaging sheet 58 and the absorbent body 56 in the high compression portion 51 and the shape maintenance of the absorbent body 56 itself. Furthermore, when the packaging sheet 58 and the absorbent body 56 are bonded by hot melt adhesives HM1 and HM2, as the surface area increases due to the formation of the high compression portion 51, more hot melt adhesives HM1 and HM2 than usual are required to fully maintain the bonding strength between the packaging sheet 58 and the absorbent body 56 and the shape maintenance of the absorbent body 56 itself. Therefore, it is preferred that the surface of the absorbent body 56 and the inner surface of the packaging sheet 58 be bonded by 5.0 to 20.0 g / m 2 , especially 7.5 to 15.0 g / m 2 The hot melt adhesives HM1 and HM2 are used for bonding.

[0171] For example, in Fig. 9 When the recesses due to the high compression portion 51 are formed on the surface of the absorbent body 56 as shown in FIG. 1 , the above-mentioned amount of hot melt adhesive HM can be achieved by providing two layers of hot melt adhesive HM1 and HM2 on the back side of the absorbent body 56 over the entire area having the high compression portion 51. Such a structure can be manufactured as follows: Fig.13 As shown in FIG. 1 , after the first hot melt adhesive HM1 is applied to substantially the entire surface of the inner surface of the unfolded packaging sheet 58 that faces the absorbent body 56, the absorbent body 56 is arranged in the middle portion of the first hot melt adhesive HM1 in the width direction WD on the packaging sheet 58, and the back side of the absorbent body 56 is bonded to the packaging sheet 58 by means of the first hot melt adhesive HM1. Then, after the second hot melt adhesive HM2 is applied to substantially the entire surface of the absorbent body 56, as shown in FIG. Fig.14 As shown in FIG. 1 , the portions of the packaging sheet 58 extending toward the two sides of the absorbent body 56 are folded back onto the surface of the absorbent body 56, and the surface of the absorbent body 56 and the folded back portions of the packaging sheet 58 are bonded to each other by means of the first hot melt adhesive HM1 and the second hot melt adhesive HM2, and the overlapping portions of the packaging sheet 58 are bonded to each other by means of the first hot melt adhesive HM1, and then as shown in FIG. Fig. 9 As shown, a lattice-shaped high compression portion 51 is formed by embossing.

[0172] To reduce costs, the absorbent member 50 may be Fig. 9 As shown in the figure, there is no other sheet layer such as paper or nonwoven fabric between the packaging sheet 58 and the absorbent body 56 (of course, an adhesive layer may be provided), or other sheet layers may be provided on at least one side of the front and back of the absorbent body 56.

[0173] (Stand-up pleats)

[0174] The standing pleat portion 60 has a standing portion 68 standing up from the side of the inner body 200, and the standing portion 68 contacts the range from the wearer's groin through the leg circumference to the buttocks to prevent side leakage. The standing pleat portion 60 can also be omitted as needed. The root side portion 60B of the standing pleat portion 60 shown in the figure stands up obliquely toward the central side in the width direction, and the front end side portion 60A stands up obliquely toward the outer side in the width direction compared to the middle portion, but it is not limited to this, and appropriate changes such as standing up toward the central side in the width direction as a whole can also be made.

[0175] To explain in more detail, the standing gather portion 60 shown in the figure is formed by folding a band-shaped gather sheet 62 having a length equal to the length of the inner body 200 in the front-back direction in two pieces by folding it back in the width direction WD at the front end portion, and fixing a plurality of elongated gather elastic members 63 at intervals in the width direction WD in a state of being stretched in the longitudinal direction between the folded portion and the adjacent sheets. The base end portion (the end portion on the opposite side of the sheet folded back portion in the width direction WD) of the standing gather portion 60 on the opposite side of the front end portion is a root portion 65 fixed to the side portion of the inner body 200, and the portion other than the root portion 65 is a main body portion 66 (the portion on the folded back portion side) extending from the root portion 65. In addition, the main body portion 66 includes a root side portion 60B extending toward the center side in the width direction, and a front end side portion 60A folded back at the front end of the root side portion 60B and extending toward the outside in the width direction. Furthermore, the two end portions in the front-to-back direction of the main body portion 66 become inverted portions 67 fixed to the side surface of the top sheet 30 in a inverted state, and on the other hand, the middle portion in the front-to-back direction between them becomes a non-fixed standing portion 68, and a pleated elastic component 63 is fixed in an extended state along the front-to-back direction LD to at least the front end portion of the standing portion 68.

[0176] In the raised gather section 60 constructed as above, the raised portion 68 is contracted by the contraction force of the gather elastic member 63 as shown in FIG. Figure 3 In particular, if the root portion 65 is located on the back side of the inner body 200, the raised portion 68 is raised in a manner that opens outward in the width direction in the crotch and its vicinity, so that the raised pleat portion 60 is in surface contact with the leg circumference, thereby improving the fit. The root portion 65 may also be fixed to the surface side of the inner body 200, for example, the surface of both sides of the top sheet 30.

[0177] In the curved structure that the main body 66 is composed of the root side portion 60B extending to the central side in the width direction and the front end portion 60A folded back at the front end of the root side portion 60B and extending outside in the width direction, in the prostrate portion 67, the front end portion 60A is engaged with the root side portion 60B in a prostrate state, and the root side portion 60B is engaged with the top sheet 30 in a prostrate state. The engagement of the opposite surface of the prostrate portion 67 can use at least one of the means based on material welding such as hot melt adhesives based on various coating methods and heat sealing or ultrasonic sealing. In this case, the engagement of the root side portion 60B and the top sheet 30 and the engagement of the front end portion 60A and the root side portion 60B can be carried out by the same means, or by different means. For example, it is preferred to utilize hot melt adhesives to carry out the engagement of the root side portion 60B and the top sheet 30, and utilize material welding to carry out the engagement of the front end portion 60A and the root side portion 60B.

[0178] As the pleated sheet 62, a material obtained by water-repellent treatment of soft, uniform, and excellent shielding nonwoven fabrics such as spunbond nonwoven fabrics (SS, SSS, etc.), SMS nonwoven fabrics (SMS, SSMMS, etc.), and meltblown nonwoven fabrics using silicone or the like as needed can be appropriately used. The fiber unit area weight of the nonwoven fabric in this case is preferably 10 to 30 g / m 2 In addition, although not shown in the figure, a waterproof membrane may be interposed between the pleated sheets 62 folded into two pieces.

[0179] As the pleated elastic component 63, a rubber thread or the like can be used. When a spandex rubber thread is used, the thickness is preferably 470 to 1240 dtex, and more preferably 620 to 940 dtex. The elongation of the pleated elastic component 63 in the installed state is preferably 150 to 350%, and more preferably 200 to 300%. The number of pleated elastic components 63 is preferably 2 to 6, and more preferably 3 to 5. It is appropriate that the configuration interval of the pleated elastic component 63 is 3 to 10 mm. If so configured, it is easy to contact the skin with the surface within the range where the pleated elastic component 63 is configured. The pleated elastic component 63 can also be configured not only on the front end side but also on the root side.

[0180] In the rising portion 68 of the rising pleat portion 60, the inner layer and the outer layer of the pleat sheet 62 are bonded together, and the pleat elastic member 63 sandwiched therebetween is fixed by at least one of hot melt adhesives based on various coating methods and fixing means based on material fusion such as heat sealing or ultrasonic sealing. If the entire surface of the inner layer and the outer layer of the pleat sheet 62 are bonded together, the flexibility will be impaired, so it is preferred that the portion other than the bonding portion of the pleat elastic member 63 is not bonded or is weakly bonded. In the example shown in the figure, the following structure is formed: by applying hot melt adhesive only on the outer peripheral surface of the pleated elastic component 63 using a coating means such as a coating gun or a SureWrap nozzle and sandwiching it between the inner layer and the outer layer of the pleated sheet 62, the pleated elastic component 63 is fixed to the inner layer and the outer layer of the pleated sheet 62, and the inner layer and the outer layer of the pleated sheet 62 are fixed to each other using only the hot melt adhesive applied to the outer peripheral surface of the pleated elastic component 63.

[0181] Similarly, for fixing the collapsed portion 67, at least one of a hot melt adhesive by various coating methods and a material welding method such as heat sealing or ultrasonic sealing may be used.

[0182] (flank)

[0183] like Figure 1 to Figure 4 As shown in the figures, it is preferred that side flaps 70 extending to the sides of the absorbent body 56 are provided on both sides of the inner body 200, and side stretch regions SG that stretch in the front-back direction are formed in the side flaps 70. The side flaps 70 shown in the figure have: one or more elongated side elastic members 73 arranged at intervals along the front-back direction LD; a first sheet layer 71 facing the outside of the side elastic members 73; and a second sheet layer 72 facing the inside of the side elastic members 73.

[0184] The sheet material constituting the first sheet layer 71 and the second sheet layer 72 is not particularly limited, and an appropriate nonwoven fabric such as a nonwoven fabric that can be used in the above-mentioned standing pleated portion 60 and the above-mentioned outer body 12F, 12B can be selected. In the example shown in the figure, the pleated sheet 62 of the standing pleated portion 60 is extended as described later to form the first sheet layer 71 and the second sheet layer 72. In this case, the front and rear ends of the side flaps 70 are consistent with the front and rear ends of the standing pleated portion 60 (that is, the front and rear ends of the inner body 200 in this case).

[0185] The side elastic members 73 are not particularly limited, and the same elongated elastic members as the above-mentioned gather elastic members 63 can be used. The elongation of the side elastic members 73 in the installed state is preferably 150 to 350%, more preferably 200 to 270%. The number of the side elastic members 73 is preferably 2 to 16, more preferably 6 to 10. The arrangement interval of the side elastic members 73 is preferably 5 to 10 mm.

[0186] The side elastic component 73 is fixed to the first sheet 71 and the second sheet 72. The first sheet 71 and the second sheet 72 are attached, and the side elastic component 73 sandwiched therebetween can be fixed by fixing means based on material welding, such as hot melt adhesive HM, heat sealing or ultrasonic sealing based on various coating methods. If the bonding area of ​​the first sheet 71 and the second sheet 72 is large, the flexibility is impaired, so the part other than the bonding part of the side elastic component 73 is preferably not bonded or weakly bonded. In the example of the figure, the following structure is formed: by using a coating means such as a coating gun or a SureWrap nozzle to apply the hot melt adhesive HM only on the peripheral surface of the side elastic component 73 and sandwich it between the first sheet 71 and the second sheet 72, the side elastic component 73 is fixed to the first sheet 71 and the second sheet 72, and the first sheet 71 and the second sheet 72 are fixed only by the hot melt adhesive HM coated on the peripheral surface of the side elastic component 73.

[0187] In the example shown in the figure, the sheet material constituting the first sheet layer 71 and the sheet material constituting the second sheet layer 72 are folded back at the side edges of the side flaps 70, and the folded back portions are fixed to the back surface (bag-shaped closure) of the liquid-impermeable sheet 11. This fixing may be performed by welding the materials in addition to using the hot melt adhesive HM as in the example shown in the figure.

[0188] The side wings 70 may also be omitted.

[0189] <Effect confirmation test 1>

[0190] Samples of the absorbent member were prepared under the various conditions shown in Table 1, and evaluation of damage to the packaging sheet, diffusion behavior confirmation test, non-pressurized rewet test, pressurized rewet test, and absorption rate test were performed. It should be noted that the weight per unit area of ​​the packaging sheet, the dry tensile strength of the packaging sheet, and the tensile elongation at break of the packaging sheet in Tables 1 and 3 are measured values ​​of the material before the pressing portion is formed.

[0191] The dimensions of each part of Sample 1 are as follows.

[0192] Length d3 of the first high compression portion 51a: 3 mm

[0193] The major diameter d1 of the second high compression part and the third high compression part: 4.82mm

[0194] The short diameter d2 of the second high compression part and the third high compression part: 3mm

[0195] 1st interval 81d: 12.63mm

[0196] Second interval 82d: 12.63mm

[0197] Intersection angle between the first imaginary straight line 81 and the second imaginary straight line 82: 90 degrees

[0198] The dimensions of each part of Sample 1 are as follows.

[0199] Length d3 of the first high compression portion 51a: 2 mm

[0200] The major diameter d1 of the second high compression part and the third high compression part: 3.82mm

[0201] The short diameter d2 of the second high compression part and the third high compression part: 2mm

[0202] 1st interval 81d: 12.63mm

[0203] Second interval 82d: 12.63mm

[0204] Intersection angle between the first imaginary straight line 81 and the second imaginary straight line 82: 90 degrees

[0205] In samples 1 to 7, a high compression portion was formed over the entire surface of the absorbent member at a pressure of 0.4 MPa. Sample 8 is a comparative example having no high compression portion. Conditions other than the specifications shown in Table 1 are common to all samples.

[0206] (Evaluation of damaged packaging)

[0207] The surface of the sample of the absorbing member was visually observed, and the case where damage occurred at the same position as the high compression portion over substantially the entire surface of the absorbing member was evaluated as ×, the case where small damage occurred on a part of the surface of the absorbing member but most of it was not damaged was evaluated as △, and the case where no damage occurred at all was evaluated as 0.

[0208] (Diffusion behavior confirmation test)

[0209] This test was carried out by the following procedure.

[0210] (1) Place the sample on a horizontally placed flat plate with its surface (the surface with the pits in the highly compressed portion) facing upward, and fix the four corners of the sample to the flat plate with tape in an unfolded state.

[0211] (2) About 5 g of Kiriya's Edible Blue No. 1 (Brilliant Blue FCF) (package type: powder) was dissolved in about 300 ml of artificial urine to prepare a blue test solution.

[0212] (3) Place an injection cylinder (an acrylic resin cylinder with an inner diameter of 23 mm, an outer diameter of 25 mm, and a height of 100 mm) at the center of the sample surface (the center in the width direction and the center in the front-back direction) and keep it vertical. Use a measuring cylinder to inject 1.5 cm of liquid at a time into the upper opening of the injection cylinder. 3 of blue test fluid.

[0213] (4) After 5 minutes, remove the injection tube, take still images of the sample surface and back, read the captured image data using image analysis software, and measure the areas of the blue parts on the sample surface and back, respectively.

[0214] (Absorption rate test)

[0215] This test was carried out by the following procedure.

[0216] (1) Place the sample on a horizontally placed flat plate with its surface (the surface with the pits in the highly compressed portion) facing upward, and fix the four corners of the sample to the flat plate with tape in an unfolded state.

[0217] (2) Hold the injection cylinder (an acrylic resin cylinder with an inner diameter of 3 mm, an outer diameter of 6 mm, and a height of 220 mm) vertically above the center of the sample surface (the center in the width direction and the center in the front-to-back direction) so that the distance between the lower end of the injection cylinder and the sample surface is 10 mm.

[0218] (3) Use a measuring cylinder with a 7 cm 3 / sec. to inject 70 cm 3 The above blue test solution was injected and the absorption time (seconds) from the start of injection to the disappearance of artificial urine on the sample surface (complete absorption) was measured using a stopwatch, and this time was taken as the first absorption rate. It should be noted that whether it was completely absorbed was determined by visual observation by the operator.

[0219] (4) After leaving it for 30 minutes, perform the above-mentioned operation (3) again and measure the absorption rate for the second time.

[0220] (Re-infiltration test under non-pressure)

[0221] This test was carried out by the following procedure.

[0222] (1) Place the sample on a horizontally placed flat plate with its surface (the surface with the pits in the highly compressed portion) facing upward, and fix the four corners of the sample to the flat plate with tape in an unfolded state.

[0223] (2) An injection cylinder (acrylic resin cylinder with an inner diameter of 23 mm, an outer diameter of 25 mm, and a height of 100 mm) was placed at the center of the sample surface (the center in the width direction and the center in the front-back direction) and kept vertically.

[0224] (3) Use a measuring cylinder with a 7 cm 3 / sec. to inject 50 cm 3 The above-mentioned blue test solution is injected and waits until the artificial urine disappears from the surface of the sample (is completely absorbed).

[0225] (4) The weight (g) of 10 sheets of Advantec qualitative filter paper No. 2 (100 mm long x 100 mm wide square) was measured to the third decimal place using an electronic balance.

[0226] (5) 30 minutes after the artificial urine injected by the above (3) is completely absorbed, 10 pieces of the above filter paper are aligned and overlapped and placed on the injection site of the artificial urine, and a 1 kg weight is further placed thereon. At this time, the weight has a flat bottom surface of a square with a length of 100 mm and a width of 100 mm. In addition, the filter paper and the weight are placed on the sample surface in a manner such that the longitudinal and transverse directions of the filter paper and the weight are along the front-back direction and the width direction of the sample, and the center of the filter paper and the weight is located at the center of the sample surface.

[0227] (6) After placing the weights in (5) for 1 minute, remove all filter papers and measure their weight (g) to the second decimal place. Subtract the weight measured before absorption in (4) from the weight measured after absorption to obtain the non-pressurized re-infiltration amount.

[0228] (Re-seepage test under pressure)

[0229] This test was carried out by the following procedure.

[0230] (1) Place the sample on a horizontally placed flat plate with its surface (the surface with the pits in the highly compressed portion) facing upward, and fix the four corners of the sample to the flat plate with tape in an unfolded state.

[0231] (2) An injection cylinder (acrylic resin cylinder with an inner diameter of 23 mm, an outer diameter of 25 mm, and a height of 100 mm) was placed at the center of the sample surface (the center in the width direction and the center in the front-back direction) and kept vertically.

[0232] (3) Use a measuring cylinder with a 7 cm 3 / sec. to inject 50 cm 3 Wait until the artificial urine disappears from the surface of the sample (is completely absorbed) after the blue test solution is injected, then wait 30 minutes and use a measuring cylinder to measure the blue test solution again at 7 cm 3 / sec. to inject 50 cm 3 of the above blue test solution.

[0233] (4) 20 minutes after the second injection of artificial urine was completely absorbed, a 3 kg weight was placed at the injection position of artificial urine and left for 10 minutes. The weight had a square flat bottom surface of 100 mm long × 100 mm wide, and was placed on the sample surface in such a way that the longitudinal and transverse directions of the weight were along the front-back direction and width direction of the sample and the center of the weight was located at the center of the sample surface.

[0234] (5) The weight (g) of 30 sheets of Advantec qualitative filter paper No. 2 (100 mm long × 100 mm wide square) was measured to the third decimal place using an electronic balance.

[0235] (6) After the above step (4), 30 sheets of the above filter paper are overlapped and aligned in the center and direction and sandwiched between the weight and the sample surface. After 20 seconds, all the filter papers are taken out and their weight (g) is measured to the second decimal place. The measured value of the weight before absorption in the above step (5) is subtracted from the measured value of the weight after absorption to obtain the re-infiltration amount under pressure.

[0236]

[0237] Table 2 shows the test results.

[0238]

[0239] Samples 1 and 2 not only have better diffusion properties than Sample 8 (the diffusion area is large enough) as Samples 3 to 7, but also have less rewet amount under no pressure and rewet amount under pressure than Samples 3 to 8. In addition, Samples 1 and 2 have better absorption speed than Samples 7 and 8 as Samples 3 to 6. In addition, Samples 1 and 2 have excellent anti-tear properties of crepe paper.

[0240] <Effect Confirmation Test 2>

[0241] The various absorbent members shown in Table 3 were used to produce Figures 1 to 6 The samples of the shorts-type disposable diapers shown in Table 3 were subjected to the above-mentioned non-pressurized rewet test, pressurized rewet test and absorption rate test. It should be noted that the size and arrangement of each part of the high compression portion of sample 9 are the same as those of sample 1. In addition, samples 10 and 11 are comparative examples without high compression portions. In addition, the conditions other than the specifications shown in Table 3 are common to all samples.

[0242] [Table 3]

[0243]

[0244] Table 4 shows the test results.

[0245] [Table 4]

[0246]

[0247] In this test using diaper samples, the same tendency as in the effect confirmation test 1 using only the absorbent member was observed. That is, sample 9 showed a smaller amount of rewet under no pressure and a smaller amount of rewet under pressure than samples 10 and 11, and also had a superior absorption speed.

[0248] <Explanation of terms in the specification>

[0249] Unless otherwise specified in the specification, the following terms in the specification have the following meanings.

[0250] The “front-rear direction” refers to the direction (longitudinal direction) indicated by symbol LD in the figure, and the “width direction” refers to the direction (left-right direction) indicated by WD in the figure. The front-rear direction is orthogonal to the width direction.

[0251] The “front side” refers to the side close to the wearer's skin when worn, and the “back side” refers to the side away from the wearer's skin when worn.

[0252] The “front surface” refers to the side close to the wearer's skin when worn, and the “rear surface” refers to the side away from the wearer's skin when worn.

[0253] "Elongation" means a value when the natural length is 100%. For example, an elongation of 200% has the same meaning as an elongation of 2 times.

[0254] "Artificial urine" is 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.

[0255] "Gel strength" was measured as follows. 1.0 g of a high absorbent polymer was added to 49.0 g of artificial urine and stirred with a stirrer. The resulting gel was placed in a constant temperature and humidity chamber at 40°C x 60% RH for 3 hours and then returned to room temperature. The gel strength was measured using a curdmeter (manufactured by I.techno Engineering: Curdmeter-MAX ME-500).

[0256] ·The "weight per unit area" is measured as follows. After pre-drying the sample or test piece, place it in a test room or device under standard conditions (the temperature of the test site is 23±1°C and the relative humidity is 50±2%) to allow it to reach a constant weight. Pre-drying means allowing the sample or test piece to reach a constant weight in an environment with a temperature of 100°C. It should be noted that for fibers with an official moisture regain of 0.0%, pre-drying is not required. Use a template (100mm×100mm) for sample collection to cut a sample of 100mm×100mm in size from the test piece that has reached a constant weight. Measure the weight of the sample and multiply it by 100 to calculate the weight per 1 square meter as the weight per unit area.

[0257] The "thickness" of thick parts such as the absorbent body 56 and the absorbent member 50 is measured using a thickness gauge (Peacock, dial-type thickness gauge, model H (measuring range: 0-10 mm, measuring head: circular pressurized plane with a diameter of 10 mm, measuring force: about 1.7 N, pressure: about 21.7 KPa)) produced by Ozaki Manufacturing Co., Ltd., with the test part and the thickness gauge being placed horizontally. The thickness of the absorbent member 50 (non-high compression portion 52) is determined as follows. That is, in the non-high compression portion 52 of the absorbent member 50, 10 areas with the largest inscribed circle inscribed in the outer shape of the non-high compression portion 52 are selected, and the thickness measured by aligning the center of the measuring head of the above-mentioned thickness gauge with the center of the inscribed circle of the area is taken as the thickness of the absorbent member 50 (non-high compression portion 52).

[0258] The “thickness” of the high compression portion 51 is obtained by subtracting the depth of the high compression portion 51 from the thickness of the absorbing member 50 (non-high compression portion 52 ).

[0259] The "depth" of the high compression portion 51 is measured using the OneShot 3D measurement microscope VR-3200 manufactured by KEYENCE Corporation or an equivalent device, and the image analysis software "VR-H2A" or an equivalent software. In principle, the magnification during measurement is 12 times and the field of view is 24 mm × 18 mm, but the magnification and field of view can be changed according to the size of the high compression portion 51. For the specific measurement process, refer to Fig.23 The following is an explanation. That is, using the above-mentioned software, etc., the depth (measurement cross-sectional curve) distribution at the line segment Q1 passing through the center (center of gravity in the case of a shape other than a circle) of a high compression portion 51 in the image portion (X portion in the figure) displayed at a top view is obtained. The surface roughness component with a wavelength shorter than λc: 800μm (where λc is the "filter defining the boundary between the roughness component and the waviness component" described in JIS-B0601 "3.1.1.2") is removed from the cross-sectional curve of the embossing depth distribution using a low-pass filter, and the position where the curve in the "contour curve Q2" of the obtained image portion (Y portion in the figure) displayed at a cross-sectional view becomes almost flat, or the position where the curve is convex upward and the strongest is taken as two boundary points P1 and P2, and the minimum value of the height of the range sandwiched by the boundary points P1 and P2 is obtained. Furthermore, the average value of the height values ​​of the boundary points P1 and P2 is taken as the maximum value of the height. Then, the minimum value of the height is subtracted from the maximum value of the height, so that the depth of the high compression portion 51 can be obtained. In addition, the two boundary points P1 and P2 are selected by visual inspection. It should be noted that, in this selection, the image of the high compression portion 51 in the measurement from a top view can be used as a reference. The above measurement is performed on any 10 high compression portions 51 on the surface, and the result is the average value.

[0260] The thickness of non-woven fabrics and other thin sheets is measured using an automatic thickness tester (KES-G5 portable compression measurement program) at a load of 0.098N / cm 2 And pressurized area: 2cm 2 Automatic determination under the conditions of

[0261] The "area ratio" refers to the ratio of the area of ​​the target portion per unit area, and is a value expressed as a percentage by dividing the total area occupied by the target portion (e.g., the high compression portion 51) in the entire target region (e.g., the back surface of the absorbing member 50) by the area of ​​the target region. The size and area of ​​the high compression portion 51 are measured by taking a still image of the surface of the absorbing member 50 having the high compression portion 51 and reading the taken image data using image analysis software. At this time, the measurement target portion of the high compression portion 51 is automatically selected based on the shadow, or is selected by visual inspection when automatic selection is not possible.

[0262] The "water absorption" is measured in accordance with JIS K7223-1996 "Test method for water absorption of super absorbent resin".

[0263] The "water absorption rate" is the "time to the end point" when JIS K7224-1996 "Water absorption rate test method for super absorbent polymers" is carried out using 2 g of a super absorbent polymer and 50 g of physiological saline.

[0264] The "expanded state" refers to a state in which the device is flatly expanded without any contraction (including any contraction such as contraction due to elastic members) or relaxation.

[0265] ・ Unless otherwise specified, the dimensions of each part refer to the dimensions in the unfolded state, not the natural length state.

[0266] If there is no description of the environmental conditions during the test or measurement, the test or measurement was carried out in a test room or device under standard conditions (temperature of the test site is 23±1°C and relative humidity is 50±2%).

[0267] Industrial Applicability

[0268] The present invention can be used in all absorbent articles having a crotch portion (preferably also having a portion extending from the crotch portion to either or both of the front and rear sides) such as disposable diapers such as pants-type disposable diapers, belt-type disposable diapers, and pad-type disposable diapers, and sanitary napkins.

[0269] Explanation of symbols

[0270] 11…Liquid-impermeable sheet, 12A…Side seal, 12B…Rear outer body, 12E…Waist extension portion, 12F, 12B…Outer body, 12F…Front outer body, 12S, 12H…Sheet material, 13…Cover nonwoven fabric, 16, 19…Elastic components below the waist, 17…Waist elastic components, 18…Useless elastic components, 20…Inner body joint portion, 200…Inner body, 30…Top sheet, 40…Intermediate sheet, 50…Absorbent member, 50P…Packaging body, 51…Highly compressed portion, 51a…First highly compressed portion, 51b…Second highly compressed portion, 51c…Third highly compressed portion, 52…Non-highly compressed portion, 56…Absorbent body, 56L…Low basis weight portion, 58…Packaging sheet, 60…Stand-up pleat portion, 60A…Front end portion, 60B… Root side portion, 62…pleated sheet, 63…pleated elastic component, 67…falling portion, 68…standing portion, 70…side wing, 71…first sheet layer, 72…second sheet layer, 73…side elastic component, 81…first imaginary straight line, 82…second imaginary straight line, 90…support roller, 91…protrusion, 92…smooth roller, A1…non-stretchable area, A2…stretchable area, B…back body, C…hip cover, F…front body, HM…hot melt adhesive, HM1…first hot melt adhesive, HM2…second hot melt adhesive, L…middle area, LD…front and rear direction, LO…leg opening, M…crotch, SG…side stretchable area, T…waist area, TD…thickness direction, U…lower waist, W…waist, WD…width direction, WO…waist opening.

Claims

1. An absorbent article, characterized in that: With crotch, The absorbent member includes an absorbent body disposed in a front-back direction range including the crotch portion, and a wrapping sheet made of crepe paper wrapping the absorbent body. The absorbent body is formed by mixing and aggregating pulp fibers and superabsorbent polymer particles. The absorbent member has highly compressed portions arranged at intervals in the thickness direction so as to be recessed from the surface or back surface of the absorbent member into the absorbent body. The portion other than the high compression portion in the arrangement region of the high compression portion is a non-high compression portion which is thicker and has a lower density than the high compression portion. The high compression portion has an outer shape without an inflection point or a bending point, and the diameter of the largest inscribed circle inscribed in the outer shape of the high compression portion is 2 mm to 5 mm, and the circumference of the outer shape of the high compression portion is 1 to 2.5 times the circumference of the largest inscribed circle inscribed in the outer shape of the high compression portion, The diameter of the largest inscribed circle inscribed in the outer shape of the non-highly compressed portion is 6.5 mm or less.

2. The absorbent article according to claim 1, wherein The weight per unit area of ​​the pulp fibers in the absorbent is 100 g / m 2 ~500g / m 2 , The weight ratio of pulp fibers to superabsorbent polymer particles in the absorbent is 45:55 to 65:

35. The packaging sheet is a crepe paper having a tensile breaking elongation of 20% to 35% in the front-to-back direction and a tensile breaking elongation of 4% to 8% in the width direction as specified in JIS P 8113:2006. The thickness of the non-high compression portion is 5 mm to 15 mm. The thickness of the high-compression portion is 30% to 50% of the thickness of the non-high-compression portion.

3. The absorbent article according to claim 1 or 2, wherein: The highly compressed portion is composed only of the highly compressed portion compressed in the thickness direction so as to be recessed from the surface of the absorbent member into the absorbent body.

4. The absorbent article according to claim 1 or 2, wherein: In the arrangement region of the high compression portion, a virtual grid is defined, wherein first virtual straight lines along the first direction are repeatedly arranged at first intervals in a second direction inclined 80° to 90° clockwise relative to the first virtual straight line when viewed from above, and second virtual straight lines along the second direction are repeatedly arranged at second intervals in the first direction, and A minimum imaginary quadrilateral with the intersection of the first imaginary straight line and the second imaginary straight line as a vertex is defined. In this case, The high compression portion includes: a first high compression portion arranged at the intersection of the first imaginary straight line and the second imaginary straight line; and a second high compression portion arranged between adjacent first high compression portions of the first imaginary straight line and between adjacent first high compression portions of the second imaginary straight line. and a third high compression portion disposed at the intersection of the diagonal lines of the imaginary quadrilateral, The first high compression portion forms a circle centered at the intersection of the first imaginary straight line and the second imaginary straight line. The second high compression portion is an ellipse or a rounded rectangle having a center of gravity at the midpoint of each side of the imaginary quadrilateral and a major axis along each side. The third high compression portion is an ellipse or a rounded rectangle having a center of gravity at the intersection of the diagonals of the imaginary quadrilateral and a major axis along the front-back direction, or a circle centered at the intersection of the diagonals of the imaginary quadrilateral.

5. The absorbent article according to claim 4, wherein: The diameter of the first high compression portion is 1 mm to 4 mm. The length of the major axis of the second high compression portion is 3 mm to 6 mm, and the length of the minor axis is equal to the diameter of the first high compression portion. The third high compression portion has the same size and shape as the second high compression portion except that the long axis is oriented along the front-back direction. The minimum interval between the adjacent first high compression parts and the adjacent second high compression parts is 1 mm to 2 mm.

6. The absorbent article according to claim 5, wherein: The virtual grid forms an oblique grid shape in which the first virtual straight lines are inclined 40° to 50° clockwise relative to the front-rear direction in a plan view, and the second virtual straight lines are inclined 40° to 50° counterclockwise relative to the front-rear direction in a plan view.

7. A method for producing an absorbent member comprising an absorbent body formed by mixing and aggregating pulp fibers and superabsorbent polymer particles, and a wrapping sheet made of crepe paper for wrapping the absorbent body, The manufacturing method is characterized in that it comprises: The first step is to form an absorbent body by mixing and aggregating the pulp fibers and the superabsorbent polymer particles; A second step is to form a package in which the entire absorbent body is packaged with a packaging sheet; and In the third step, the package body is clamped between a support roller and a smooth roller, the support roller having protrusions arranged at intervals on the outer peripheral surface, and the smooth roller having a cylindrical surface opposed to the support roller, and a portion of the package body clamped between the plurality of protrusions of the support roller and the smooth roller is pressed in a manner that the portion is recessed from the surface or back side of the package body into the absorbent body. When the arrangement of the front end faces of the protrusions in the supporting roller is unfolded on a plane, the diameter of the maximum inscribed circle inscribed in the outer shape of the front end faces of the protrusions in the arrangement area of ​​the front end faces is 2 mm to 5 mm, and the circumference of the outer shape of the front end faces of the protrusions is 1 to 2.5 times the circumference of the maximum inscribed circle inscribed in the outer shape of the front end faces of the protrusions, and the diameter of the maximum inscribed circle inscribed in the outer shape of the portion other than the front end faces in the arrangement area of ​​the front end faces is less than 6.5 mm.

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