Absorbent article

Abstract

The purpose of the present invention is to improve the retention of highly absorbent polymer particles in an absorbent containing broad-leaved tree pulp fibers. The problem is solved by an absorbent article provided with an absorbent material (50) having an absorbent body (56) and a packaging sheet (58) that wraps the absorbent body (56), the absorbent body (56) being formed by mixing and aggregating pulp fibers and highly absorbent polymer particles, and the highly absorbent polymer particles (56p) being formed by mixing and aggregating pulp fibers and highly absorbent polymer particles (56p). The ratio of particles having a particle diameter smaller than the average fiber length of the broad-leaved tree pulp fibers before swelling is 60 mass% or more, and the absorbent material (50) has a plurality of highly compressed sections (51) that are compressed in the thickness direction (TD) and are arranged at intervals so as to be recessed from the surface of the absorbent material (50) into the absorbent body (56). In the arrangement region of the plurality of high-compression sections (51), portions other than the high-compression sections (51) are non-high-compression sections (52) that are thicker and lower in density than the high-compression sections (51), the shortest distance of each of the high-compression sections (51) with respect to the closest other high-compression sections (51) is 1-4 mm, and the area of each of the high-compression sections (51) is 2-200 mm2.

Description

TECHNICAL FIELD

[0001] The present application relates to an absorbent article such as a disposable diaper, a sanitary napkin, an incontinence pad, a panty liner (a secretion pad), and the like. BACKGROUND

[0002] An absorbent body (also referred to as an absorbent core layer, etc.) of an absorbent article generally contains pulp fibers and superabsorbent polymer particles. As the pulp fibers, conifer pulp (NBKP) fibers (pulp fibers derived from conifer trees) are often used, but in recent years, broadleaf pulp (LBKP) fibers (pulp fibers derived from broadleaf trees) are also being studied for use for reasons such as being less expensive than conifer pulp fibers (for example, refer to Patent Documents 1 and 2).

[0003] However, compared to an absorbent body in which pulp fibers composed only of conifer pulp fibers and superabsorbent polymer particles are mixed and agglomerated, an absorbent body in which pulp fibers containing both conifer pulp fibers and broadleaf pulp fibers and superabsorbent polymer particles are mixed and agglomerated has a problem of lower retention of superabsorbent polymer particles (superabsorbent polymer particles are easily moved).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-014646

[0007] Patent Document 2: Japanese Patent No. 7293479 SUMMARY

[0008] Problems to be Solved by the Invention

[0009] Therefore, the main problem of the present application is to improve the retention of superabsorbent polymer particles in an absorbent body containing broadleaf pulp fibers.

[0010] Technical Means for Solving the Problem

[0011] One solution to the above problem is as follows.

[0012] <First Solution>

[0013] An absorbent article characterized by having a crotch portion,

[0014] provided with an absorbent member having an absorbent body disposed in a front-rear direction range including the crotch portion, and a wrapping sheet wrapping the absorbent body,

[0015] The absorbent body is a mixture of pulp fibers containing broadleaf tree pulp fibers and high-absorbency polymer particles,

[0016] The proportion of particles having a particle size of less than the average fiber length of the broadleaf tree pulp fibers before swelling is 60% or more in the high-absorbency polymer particles,

[0017] The absorbent member is provided with a plurality of high-compression portions compressed in the thickness direction at intervals in a manner recessed from at least one of the back surfaces of the absorbent member into the absorbent body,

[0018] The portions other than the high-compression portions in the arrangement region of the plurality of high-compression portions are non-high-compression portions that are thicker and lower in density than the high-compression portions,

[0019] The shortest distance of each of the high-compression portions from the closest other high-compression portion is 1 to 4 mm,

[0020] The area of each of the high-compression portions is 2 to 200 mm 2 .

[0021] (EFFECTS)

[0022] The present inventors have found that, in an absorbent body containing broadleaf tree pulp fibers, since the fiber length of the broadleaf tree pulp fibers is short, it is difficult to maintain entanglement of the pulp fibers, and as a result, high-absorbency polymer particles easily move. Therefore, in order to prevent movement of high-absorbency polymer particles, it is preferable that the fiber length of the broadleaf tree pulp fibers be longer, but the broadleaf tree pulp fibers are of natural origin, and there are limitations in adjusting characteristics such as fiber length. In addition, reducing the proportion of broadleaf tree pulp fibers results in a decrease in cost advantages, and thus is not preferable.

[0023] However, if the high-compression portions are provided at the area and intervals of the present aspect, as can be seen from the experimental results described later, in an absorbent body containing broadleaf tree pulp fibers, the retention of high-absorbency polymer particles is improved. That is, since the distance between pulp fibers is shortened in the high-compression portions, entanglement of the pulp fibers is strengthened, the gaps of the pulp fibers that are the movement paths of the high-absorbency polymer particles are reduced, the contact portions of the pulp fibers with the high-absorbency polymer particles are increased, and the like, and thus movement of the high-absorbency polymer particles in the absorbent body and movement of the high-absorbency polymer particles out of the absorbent body are suppressed.

[0024] <Second Aspect>

[0025] The absorbent article according to claim 1, wherein the area ratio of the high-compression portions in the arrangement region of the plurality of high-compression portions is 10 to 35%,

[0026] The diameter of the largest inscribed circle inscribed in the outline of the non-high compression portion is 30 mm or less.

[0027] (EFFECTS)

[0028] As in the present aspect, when the high compression portions are particularly densely arranged, as described above, the high absorbent polymer particles are difficult to move in the high compression portions, and the movement of the high absorbent polymer particles of the non-high compression portions is blocked by the high compression portions, and thus the uneven distribution of the high absorbent polymer particles is also suppressed. Therefore, the retention of the high absorbent polymer particles is further improved.

[0029] Further, even in the vicinity of the high compression portion as the non-high compression portion, the absorbent is deformed in a manner stretched by the deformation of the high compression portion, and thus, compared with the case where there is no high compression portion, the advantage that the absorbent is thinned is brought about.

[0030] From these viewpoints, in order to make the area ratio of the high compression portions within the above range, and the arrangement of the high compression portions not sparse (the non-high compression portion not continuously long distances in all directions), it is particularly preferable that the diameter of the largest inscribed circle inscribed in the outline of the non-high compression portion be within the above range.

[0031] In the past, since it was considered that the dense arrangement of the high compression portions is not preferable, the adoption of the dense arrangement of the high compression portions as in the present aspect does not belong to the category of optimization usually performed.

[0032] <Third Aspect>

[0033] The absorbent article according to the second aspect, wherein the high compression portion has an outline having no inflection point and bending point, and the diameter of the largest inscribed circle inscribed in the outline of the high compression portion is 1 to 10 mm, and the circumference of the outline of the high compression portion is 1 to 15 times the circumference of the largest inscribed circle inscribed in the outline of the high compression portion.

[0034] (EFFECTS)

[0035] The size and shape of the high compression portion can be appropriately determined. However, since the high compression portion is a hard portion, if the size of the high compression portion is too large, or the shape of the high compression portion is too long in one direction, or has an excessively staggered outline, it is possible that the softness of the absorbent as a whole is insufficient, or a skin feel like a foreign matter is mixed in the absorbent (a foreign matter feel) is generated. Therefore, the size and shape of the high compression portion are preferably within the range of the present aspect.

[0036] <Fourth Aspect>

[0037] The absorbent article according to the second or third aspect, wherein, in the arrangement region of the plurality of high compression portions, a virtual grid is determined, wherein the virtual grid is formed by first virtual straight lines in a first direction being repeatedly arranged at a first interval in a second direction that is obliquely 80 to 90° with respect to the first virtual straight lines when viewed from above the first virtual straight lines, and second virtual straight lines in the second direction being repeatedly arranged at a second interval in the first direction,

[0038] and a smallest virtual quadrangle with a vertex at the intersection of the first virtual straight line and the second virtual straight line is determined,

[0039] the high compression portions include first high compression portions arranged at positions of the intersection of the first virtual straight line and the second virtual straight line, second high compression portions arranged between adjacent first high compression portions in the first virtual straight line and between adjacent first high compression portions in the second virtual straight line, and third high compression portions arranged at positions of the intersection of diagonals of the virtual quadrangle,

[0040] the first high compression portions are circular with the intersection of the first virtual straight line and the second virtual straight line as a center,

[0041] the second high compression portions are elliptical or rounded rectangular with a center of gravity at a midpoint of each side of the virtual quadrangle and a long axis along each side,

[0042] the third high compression portions are elliptical or rounded rectangular with a center of gravity at the intersection of diagonals of the virtual quadrangle and a long axis in the front-rear direction, or circular with the intersection of diagonals of the virtual quadrangle as a center.

[0043] (EFFECTS)

[0044] The shape and arrangement pattern of the high compression portions in the arrangement region of the high compression portions are appropriately determined, and if the pattern of the present aspect is used, movement of the high-absorbency polymer particles in the non-high compression portions is inhibited in the region surrounded by the high compression portions, and thus, uneven distribution of the high-absorbency polymer particles can be inhibited with fewer high compression portions, and since both a portion in which the non-high compression portions are linearly continuous in the first direction and a portion in which the non-high compression portions are linearly continuous in the second direction are present, the absorbent body as a whole is easily deformed along the body surface even if each high compression portion is hardened.

[0045] (Fifth Aspect)

[0046] The absorbent article according to the fourth aspect, wherein the diameter of the first high compression portion is 1 to 4 mm,

[0047] The long axis length of the second high compression portion is 3 to 6 mm, and the length of the short axis is equal to the diameter of the first high compression portion,

[0048] The third high compression portion is the same size and shape as the second high compression portion except that the long axis is oriented along the front-rear direction,

[0049] The minimum interval between the first high compression portion and the second high compression portion is 1 to 2 mm.

[0050] (EFFECTS)

[0051] When the high compression portions are arranged along the above-mentioned imaginary grid, the size of each high compression portion can be appropriately determined, but if within the scope of the present embodiment, the improvement in the retention of the superabsorbent particles is self-evident, and the deformability of the absorbent is also improved, and thus is preferred.

[0052] (SIXTH EMBODIMENT)

[0053] The absorbent article according to the fourth or fifth embodiment, wherein the imaginary grid is an inclined grid in which the first imaginary straight line is inclined 40 to 50° counterclockwise as viewed from above with respect to the front-rear direction, and the second imaginary straight line is inclined 40 to 50° clockwise as viewed from above with respect to the front-rear direction.

[0054] (EFFECTS)

[0055] As described above, when the high compression portions are arranged along the imaginary grid, if arranged in an inclined grid as in the present embodiment, the deformability of the absorbent when worn is excellent, and thus is preferred.

[0056] (SEVENTH EMBODIMENT)

[0057] The absorbent article according to any one of the first to sixth embodiments, wherein the unit area weight of the pulp fiber in the absorbent is 100 to 500 g / m 2 ,

[0058] The weight ratio of the pulp fiber to the superabsorbent particles in the absorbent is 40 : 60 to 65 : 35,

[0059] The thickness of the non-high compression portion is 3 to 13 mm,

[0060] The thickness of the high compression portion is 60 to 90% of the thickness of the non-high compression portion.

[0061] (EFFECTS)

[0062] Generally, when the backflow resistance is to be improved, the mixing ratio of the high-absorbency polymer particles, which have high liquid retention, is increased. In recent years, however, the mixing ratio of the high-absorbency polymer particles is increased for the purpose of thinning the absorbent, and the like. However, if the mixing ratio of the high-absorbency polymer particles is increased, the retention of the high-absorbency polymer particles tends to decrease. Therefore, it is more preferable that the high-absorbency polymer particles be compressed in the high compression section in the range of the present aspect, with the ratio of the pulp fibers and the high-absorbency polymer particles in the absorbent being within the range of the present aspect.

[0063] <eighth aspect>

[0064] The absorbent article according to any one of the first to seventh aspects, wherein the proportion of particles having a particle diameter of 500 μm or less before swelling in the high-absorbency polymer particles is 60% by mass or more,

[0065] In the absorbent, the proportion of pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm is 40% or more by mass, and the proportion of pulp fibers having a fiber width of 10 μm or more and less than 35 μm is 90% or more by mass.

[0066] (EFFECTS)

[0067] By combining the broadleaf pulp fibers and the fibers having an average fiber length longer than that of the broadleaf pulp fibers, the fiber length distribution of the pulp fibers is as in the present aspect, which can ensure the absorption capacity and the absorption speed of the absorbent, and also has the liquid retention capacity of the fibers caused by the capillary phenomenon, whereby the backflow resistance can be improved. However, there is still room for improvement in the retention of the high-absorbency polymer particles. Therefore, it is preferable that the retention of the high-absorbency polymer particles be improved by being combined with the high compression section described above.

[0068] <ninth aspect>

[0069] The absorbent article according to the eighth aspect, wherein the pulp fibers of the absorbent are composed of conifer pulp fibers and the broadleaf pulp fibers,

[0070] The mass ratio of the broadleaf pulp fibers to the conifer pulp fibers is 25 / 75 or more and 38 / 62 or less.

[0071] (EFFECTS)

[0072] As is clear from the experimental examples described later, it is particularly preferable that the pulp fibers of the absorbent be in the ratio of the present aspect.

[0073] EFFECTS OF THE INVENTION

[0074] According to the present application, in an absorbent body containing broadleaf tree pulp fibers, there are advantages such as improved retention of superabsorbent polymer particles. BRIEF DESCRIPTION OF DRAWINGS

[0075] Figure 1 is a plan view of the inner surface of the pant-type disposable diaper in an unfolded state.

[0076] Figure 2 is a plan view of the outer surface of the pant-type disposable diaper in an unfolded state.

[0077] Figure 3 is Figure 1 is a 2-2 sectional view of

[0078] Figure 4 is Figure 1 is a 3-3 sectional view of

[0079] Figure 5 (a) is a 4-4 sectional view of Figure 1 (b) is a 5-5 sectional view of Figure 5 Figure 1

[0080] Figure 6 is a perspective view of the pant-type disposable diaper.

[0081] Figure 7 is a plan view showing the outer surface of the inner body together with the outline of the outer body in an unfolded state.

[0082] Figure 8 is a plan view showing the surface of the absorbent body together with the outline of the wrapping sheet.

[0083] Figure 9 is a sectional view of the absorbent member.

[0084] Figure 10 is a plan view of the absorbent member.

[0085] Figure 11 is a plan view showing a main part of the surface of the absorbent member in an enlarged manner.

[0086] Figure 12 is a plan view showing another example of the absorbent body.

[0087] Figure 13 is a sectional view of the absorbent member showing a state before the absorbent body is wrapped with the wrapping sheet.

[0088] Figure 14 is a sectional view of the absorbent member showing a state after the absorbent body is wrapped with the wrapping sheet and before a high compression portion is formed.

[0089] Figure 15 is a sectional view of another absorbent member.​​

[0090] Figure 16 is a plan view showing a main portion of a surface of an absorbent member.

[0091] Figure 17 is a plan view showing a main portion of a surface of an absorbent member.

[0092] Figure 18 is a plan view showing a main portion of a surface of an absorbent member.

[0093] Figure 19 is a plan view showing a main portion of a surface of an absorbent member.

[0094] Figure 20 is a plan view showing a main portion of a surface of an absorbent member.

[0095] Figure 21 is a plan view showing a main portion of a surface of an absorbent member.

[0096] Figure 22 is a schematic view showing a method of manufacturing an absorbent member.

[0097] Figure 23 is an explanatory view of a method of measuring a depth of a high compression portion.

[0098] Figure 24 is a cross-sectional view schematically showing various absorbents.

[0099] Figure 25 is a schematic view showing an example of a manufacturing apparatus of an absorbent member.

[0100] Figure 26 is a schematic view showing an example of a manufacturing apparatus of an absorbent member.

[0101] Figure 27 is a side view schematically showing a strike tester.

[0102] Figure 28 is a front view schematically showing a strike tester. DETAILED DESCRIPTION

[0103] Hereinafter, as an example of the absorbent article, a panty-type disposable paper diaper will be described in detail with reference to the drawings. Each of the constituent members adjacent in the thickness direction is fixed or joined as necessary in the same manner as the known paper diaper, except for the fixing or joining portions described below. The dot pattern portion in the cross-sectional view indicates an adhesive such as a hot-melt adhesive as the fixing or joining method. The hot-melt adhesive can be applied by a slit coating, a continuous line or dotted line droplet coating, a spiral, Z-shaped, wave-shaped or the like spray coating, or a pattern coating (transfer of the hot-melt adhesive in an intaglio method) or the like known method. Instead of or in addition to the above method, the hot-melt adhesive can be applied to the outer peripheral surface of the elastic member at the fixing portion of the elastic member, thereby fixing the elastic member to the adjacent member. As the hot-melt adhesive, for example, there are EVA-based, adhesive rubber-based (elastomer-based), polyolefin-based, polyester-polyamide-based or the like, which can be used without particular limitation. As the fixing or joining method for joining the constituent members, a method using material fusion such as heat sealing or ultrasonic sealing can also be used. In a portion where liquid permeability in the thickness direction is required, the constituent members adjacent in the thickness direction are fixed or joined in a discontinuous pattern. For example, in the case of such discontinuous fixing or joining using a hot-melt adhesive, a discontinuous pattern coating such as a spiral, Z-shaped, wave-shaped or the like can be appropriately used, and when the coating is performed over a range of a width of one nozzle or more, the discontinuous pattern coating such as a spiral, Z-shaped, wave-shaped or the like can be performed with or without intervals in the width direction. As the joining method for joining the constituent members, a method using material fusion such as heat sealing or ultrasonic sealing can also be used.

[0104] In addition, as the nonwoven fabric in the following description, a known nonwoven fabric can be appropriately used depending on the site or purpose. As the constituent fiber of the nonwoven fabric, for example, in addition to polyolefin-based such as polyethylene or polypropylene, polyester-based, polyamide-based or the like synthetic fiber (including composite fiber such as core-sheath in addition to single component fiber), regenerated fiber such as rayon or cupra fiber, natural fiber such as cotton or the like can also be selected, which is not particularly limited and can be used in a mixture. In order to improve the softness of the nonwoven fabric, it is preferable to make the constituent fiber into crimped fiber. In addition, the constituent fiber of the nonwoven fabric can be hydrophilic fiber (including fiber having hydrophilicity by using a hydrophilizing agent), or hydrophobic fiber or water repellent fiber (including fiber having hydrophobicity by using a water repellent agent). In addition, the nonwoven fabric is generally classified into short fiber nonwoven fabric, long fiber nonwoven fabric, spunbond nonwoven fabric, meltblown nonwoven fabric, spunlace nonwoven fabric, thermal bond (thermal air) nonwoven fabric, needle punch nonwoven fabric, point bond nonwoven fabric, layered nonwoven fabric (including SMS nonwoven fabric, SMMS nonwoven fabric or the like in which a meltblown layer is interposed between spunbond layers) or the like depending on the fiber length, sheet forming method, fiber bonding method, layered structure, and any one of these nonwoven fabrics can be used.

[0105] Figures 1-6 An example of a pant-type disposable diaper is shown. The pant-type disposable diaper includes: a rectangular front outer cover 12F constituting a front waist portion and a rectangular back outer cover 12B constituting a back waist portion; and an inner cover 200 provided inside the outer covers 12F, 12B so as to extend from the front outer cover 12F through a crotch portion M to the back outer cover 12B. The both side portions of the front outer cover 12F and the both side portions of the back outer cover 12B are joined to form a side seal 12A, whereby an opening formed by the front and back end portions of the outer covers 12F, 12B becomes a waist opening WO through which the torso of a wearer passes, and portions surrounded by the lower edges of the outer covers 12F, 12B and the side edges of the inner cover 200 on both widthwise sides of the inner cover 200 become leg openings LO through which the legs pass. The inner cover 200 is a portion that absorbs and retains excretions such as urine, and the outer covers 12F, 12B are portions that support the inner cover 200 with respect to the body of the wearer. In addition, the reference symbol Y indicates the overall length of the diaper in the unfolded state (the front-to-back direction length from the edge of the waist opening WO of the front piece F to the edge of the waist opening WO of the back piece B), and the reference symbol X indicates the overall width of the diaper in the unfolded state.

[0106] The pant-type disposable diaper has: a waist region T determined as the front-to-back direction range having the side seal 12A (the front-to-back direction range from the waist opening WO to the upper end of the leg opening LO); and an intermediate region L determined as the front-to-back direction range of the portion forming the leg opening LO (between the front-to-back direction region of the front piece F having the side seal 12A and the front-to-back direction region of the back piece B having the side seal 12A). The portions of the front outer cover 12F and the back outer cover 12B located in the waist region T, i.e., the front waist portion and the back waist portion, can conceptually be divided into a "waist portion" W that is the edge portion forming the waist opening, and a "lower waist portion" U that is the portion below the waist portion. In general, when there is a boundary (for example, a change in the fineness or elongation of an elastic member) in the widthwise direction WD within the front waist portion and the back waist portion, the waist portion W is determined from the boundary closest to the waist opening WO side to the waist opening WO side, and when there is no such boundary, a waist extension portion 12E extending from the absorbent body 56 or the inner cover 200 toward the waist opening WO side is determined as the waist portion W. The front-to-back direction lengths of these portions differ depending on the size of the product, and can be appropriately determined, for example, the waist portion W can be set to 15 to 40 mm, and the lower waist portion U can be set to 65 to 120 mm. On the other hand, the both side edges of the intermediate region L are tapered or curved in a manner that follows the leg circumference of the wearer, and here become the portions into which the legs of the wearer are inserted. As a result, the pant-type disposable diaper in the unfolded state has a generally hourglass shape.

[0107] (Outer Cover)

[0108] As shown in the illustrated example, the outer cover 12F, 12B includes a rectangular front outer cover 12F that constitutes at least the waistline portion of the front body panel F and a rectangular rear outer cover 12B that constitutes at least the waistline portion of the rear body panel B, and the front outer cover 12F and the rear outer cover 12B can be spaced apart in the front-rear direction LD without being continuous at the crotch portion side (outer cover two-piece type), or can be continuous from the front body panel to the rear body panel (outer cover one-piece type) (not shown). The spacing distance 12d in the front-rear direction in the outer cover two-piece type can be set to about 40 to 60% of the total length Y, for example. In the illustrated example, the lower edge of the front outer cover 12F and the rear outer cover 12B is formed in a straight line shape along the width direction WD, but the lower edge of at least one of the front outer cover 12F and the rear outer cover 12B can be formed in a curved line shape along the leg opening.

[0109] In the outer cover two-piece type pant-type disposable diaper, since the inner cover 200 is exposed between the front outer cover 12F and the rear outer cover 12B, in order not to expose the liquid-impermeable sheet 11 to the back surface of the inner cover 200, it is preferable to provide the cover nonwoven fabric 13 that spans between the rear outer cover 12B and the inner cover 200 from between the front outer cover 12F and the inner cover 200. The inner surface and the outer surface of the cover nonwoven fabric 13 can be adhered to the opposite surfaces by a hot melt adhesive, for example. The nonwoven fabric for the cover nonwoven fabric 13 can be appropriately selected from the same nonwoven fabric as the material of the outer cover 12F, 12B, for example. In addition, although not shown, the outer cover can be continuous from the front body panel F to the rear body panel B through the crotch portion. In this case, the outer cover has not only a portion corresponding to the waistline region T, but also a portion corresponding to the intermediate region L.

[0110] The front outer cover 12F and the rear outer cover 12B have a front waistline portion and a rear waistline portion that constitute the waistline region T. In the illustrated example, the front outer cover 12F and the rear outer cover 12B have a front waistline portion and a rear waistline portion that constitute the waistline region T, and the front outer cover 12F and the rear outer cover 12B have a portion corresponding to the intermediate region L. Figure 1 In the illustrated example, the front outer cover 12F and the rear outer cover 12B have a front waistline portion and a rear waistline portion that constitute the waistline region T, and the front outer cover 12F and the rear outer cover 12B have a portion corresponding to the intermediate region L. Figure 2 In the illustrated example, the front outer cover 12F and the rear outer cover 12B have a front waistline portion and a rear waistline portion that constitute the waistline region T, and the front outer cover 12F and the rear outer cover 12B have a portion corresponding to the intermediate region L. Figure 7 In the illustrated example, the front outer cover 12F and the rear outer cover 12B have a front waistline portion and a rear waistline portion that constitute the waistline region T, and the front outer cover 12F and the rear outer cover 12B have a portion corresponding to the intermediate region L.

[0111] Regarding the outer cover 12F, 12B, as shown in Figure 4 and Figure 5As shown, the outer sheet layer and the inner sheet layer adjacent to the outer side and the inner side of the elastic members 16 to 19 described later are joined by a joining method such as heat fusion adhesive or welding. The outer sheet layer and the inner sheet layer can be formed of one sheet material in addition to the example shown in which they are formed of two sheet materials 12S, 12H. For example, in the latter case, the inner sheet layer and the outer sheet layer are formed of the inner side portion and the outer side portion of one sheet material folded back at the edge of the waist opening W (may be the edge on the crotch side) in part or all of the outer cover 12F, 12B. The example shown is an example of the former, and the sheet material 12S forming the outer sheet layer at the lower waist portion is wrapped around and folded back to the inner side of the sheet material 12H forming the inner sheet layer at the lower waist portion on the waist opening W side thereof, and the folded-back portion 12r extends in a manner to cover the end portion on the waist opening W side of the inner cover 200. On the other hand, at the waist portion, the folded-back portion 12r becomes the inner sheet layer adjacent to the inner side of the elastic member.

[0112] In the outer cover 12F, 12B, in order to improve the fit with the wearer's waist, the elastic members 16 to 19 are built in, and a stretch region A2 that elastically stretches in the width direction WD in conjunction with the stretching of the elastic members 16 to 19 is formed. In this stretch region A2, the outer cover 12F, 12B is contracted with the contraction of the elastic members in the natural length state, and a wrinkle or a gather is formed, and if it is stretched in the length direction of the elastic members, it can be stretched to a predetermined stretch ratio without wrinkles. As the elastic members 16 to 19, in addition to the elongated elastic members such as rubber threads (example shown), known elastic members such as belt-shaped, net-shaped, film-shaped, etc. can be used without particular limitation. As the elastic members 16 to 19, synthetic rubber can be used, and natural rubber can be used.

[0113] When the example elastic members 16 to 19 are described in more detail, a plurality of waist elastic members 17 are installed continuously in the front-rear direction at intervals on the entire width direction WD at the waist portion W of the outer cover 12F, 12B. In addition, one or more of the waist elastic members 17 provided for the region adjacent to the lower waist portion U can overlap the inner cover 200, and in addition to the width direction central portion overlapping the inner cover 200, can be provided on both width direction sides thereof, respectively. As this waist elastic member 17, it is preferable to use a thread count of 155 to 1880 dtex, particularly around 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 , particularly 0.1 to 1.0 mm 2The waist section W has approximately 2 to 15 rubber threads arranged at intervals of 2 to 12 mm, particularly 3 to 7 mm, and preferably 4 to 10 threads. This results in an elongation of 150 to 400% in the width direction WD, particularly preferably 220 to 320%. Furthermore, the waist section W does not need to use elastic components of the same fineness or elongation throughout its entire front-to-back direction LD; for example, the fineness or elongation can be locally different.

[0114] Furthermore, on the lower waist portion U of the outer casings 12F and 12B, multiple lower waist elastic members 16 and 19, each composed of a slender elastic component, are installed at intervals along the front-to-back direction, forming a lower waist stretching area (the area with the lower waist elastic members 16 and 19). As the lower waist elastic members 16 and 19, it is preferable to use materials with a fineness of 155-1880 dtex, particularly around 470-1240 dtex (in the case of synthetic rubber; in the case of natural rubber), with a cross-sectional area of ​​0.05-1.5 mm². 2 Especially 0.1~1.0mm 2 The lower waist portion U has approximately 5 to 30 rubber threads arranged at intervals of 1 to 15 mm, particularly 3 to 8 mm. The resulting elongation in the width direction WD is preferably 200 to 350%, and particularly preferably 240 to 300%. Furthermore, the lower waist portion U does not need to use elastic components of the same fineness or elongation throughout its entire front-to-back direction LD; the fineness or elongation can be locally varied.

[0115] As shown in the example of the lower waist U, when elastic members 16 and 19 are provided in the front-to-back direction range of the absorber 56, in order to prevent the absorber 56 from contracting in the width direction WD in part or all of it, as shown in the example... Figure 4 , Figure 5 and Figure 12 As shown, preferably, the middle of the width direction, which includes part or all of the portion overlapping with the absorber 56 in the width direction WD, is designated as a non-stretchable region A1, and the two sides in the width direction are designated as stretchable regions A2 (in the example shown, the stretchable region below the waist). The dimensions of the stretchable regions A2 located on both sides of the non-stretchable region A1 in the width direction can be set approximately constant in the front-to-back direction LD, as shown in the example, or they can vary in the front-to-back direction LD (not shown). Furthermore, the dimensions of the stretchable regions A2 located on both sides of the non-stretchable region A1 in the width direction WD can be set differently, except that the front panel F and the rear panel B are set to be approximately the same.

[0116] After the elastic members 16 to 17, 19 are installed between the inner sheet layer and the outer sheet layer, the elastic members 16, 19 are finely cut at one point in the width direction of the region as the non-stretching region Al or throughout the entire region by pressure and heat or cutting, and the stretchability is eliminated in the non-stretching region Al while the stretchability is maintained in the stretching region A2, thereby constructing such a stretching region A2 and a non-stretching region Al. Further, in the non-stretching region Al, there remains the unnecessary elastic member 18 which does not substantially contribute to the formation of the stretchability.

[0117] As the sheet materials 12S, 12H which form the inner sheet layer and the outer sheet layer, there can be used, without particular limitation, nonwoven fabrics. When a nonwoven fabric is used, it is preferable that the weight per unit area of each sheet be 10 to 30 g / m 2 left and right.

[0118] The elastic members 16 to 19 can be fixed to the outer case 12F, 12B by a known method. In addition, the inner sheet layer and the outer sheet layer can be joined to each other by a known method. For example, in the portion of the outer case 12F, 12B in which the elastic members 16 to 19 are provided, a hot melt adhesive HM is applied to only the outer peripheral surface of the elastic members 16 to 19 by a coating mechanism such as a coating gun or a Sure Wrap glue applicator, and is sandwiched between the inner sheet layer and the outer sheet layer, whereby the fixation of the elastic members 16 to 19 to the inner sheet layer and the outer sheet layer and the fixation of the inner sheet layer and the outer sheet layer can be performed using only the hot melt adhesive HM applied to the outer peripheral surface of the elastic members 16 to 19.

[0119] (inner case joining portion)

[0120] The joining of the inner case 200 to the outer case 12F, 12B can be performed by a joining method using material fusion such as heat sealing, ultrasonic sealing, or a hot melt adhesive. In the illustrated example, the inner case 200 is fixed to the inner surface of the outer case 12F, 12B by a hot melt adhesive applied to the back surface of the inner case 200, i.e., the back surface of the liquid-impermeable sheet 11 and the root portion 65 of the standing gathers 60 in this case. As shown in the drawing, the inner case joining portion 20 which joins the inner case 200 and the outer case 12F, 12B can be provided on substantially the entire region where the two overlap, and for example, can be provided on a portion of the inner case 200 excluding the both end portions in the width direction. Figure 2

[0121] (inner case)

[0122] The inner case 200 can adopt any shape, but in the illustrated example, is rectangular having a long side along the front-rear direction LD. As shown in the drawing, the inner case 200 has a substantially rectangular shape in which the width in the width direction WD is smaller than the length in the front-rear direction LD. Figures 3-5 ​As shown, the inner container 200 includes: a topsheet 30 as a body side; a liquid- impermeable sheet 11; and an absorbent member 50 interposed therebetween. Reference numeral 40 denotes an intermediate sheet (second sheet) provided between the topsheet 30 and the absorbent member 50 in order to rapidly transfer liquid that has permeated the topsheet 30 to the absorbent member 50, and reference numeral 60 denotes a standing gather 60 that extends from both side portions of the inner container 200 in a manner to contact with the leg girth of the wearer in order to prevent leakage of excreta to both sides of the inner container 200.

[0123] (top sheet)

[0124] The topsheet 30 has a liquid-permeable property, and examples thereof include a nonwoven fabric with or without holes, a porous plastic sheet, and the like. In addition, the topsheet 30 can be composed of one sheet or a laminated sheet obtained by joining two or more sheets. Also, the topsheet 30 can be composed of one sheet or two or more sheets in the planar direction.

[0125] The side portions of the topsheet 30 can be folded back toward the back side at the side edges of the absorbent member 50, or can be extended laterally from the side edges of the absorbent member 50 without being folded back.

[0126] In order to prevent misalignment with respect to the back side member and the like, the topsheet 30 is preferably fixed to the member adjacent to the back side by a joining method using material fusion such as heat sealing, ultrasonic sealing, or a hot melt adhesive. In the illustrated example, the topsheet 30 is fixed to the surface of the intermediate sheet 40 and the surface of the portion of the wrapping sheet 58 located on the surface side of the absorbent body 56 by a hot melt adhesive applied to the back surface thereof.

[0127] (intermediate sheet)

[0128] In order to rapidly transfer liquid that has permeated the topsheet 30 to the absorbent body 56, an intermediate sheet (also referred to as a second sheet) 40 having a liquid permeation speed faster than that of the topsheet 30 can be provided. The intermediate sheet 40 is used to rapidly transfer liquid to the absorbent body 56, improve the absorption performance of the absorbent body 56, and reduce backflow from the absorbent body 56. The intermediate sheet 40 can also be omitted.

[0129] As the intermediate sheet 40, the same materials as the topsheet 30, spunlace nonwoven fabric, spunbond nonwoven fabric, SMS nonwoven fabric, pulp nonwoven fabric, a mixed sheet of pulp and rayon, point-bonded nonwoven fabric, or crepe paper can be given. In particular, air-through nonwoven fabric is preferable due to its loftiness. Air-through nonwoven fabric preferably uses composite fibers of core-sheath structure, and in this case, the resin used for the core can be polypropylene (PP), but polyester (PET) having high rigidity is preferable. The weight per unit area is preferably 17 to 80 g / m 2 and more preferably 25 to 60 g / m 2The denier of the raw fiber of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the nonwoven fabric fluffy, as the mixed fiber of all or a part of the raw fiber, a fiber having a core not in the center or a core-sheath fiber or a core-sheath hollow fiber, a core-sheath hollow fiber is also preferably used.

[0130] The intermediate sheet 40 of the illustrated example is arranged so as to be narrower than the absorbent body 56 in the center, but can also be provided so as to cover the entire width. The front-rear direction length of the intermediate sheet 40 can be the same as the full length of the diaper, the same as the length of the absorbent member 50, or within a shorter length range centered on the area that receives liquid.

[0131] In order to prevent misalignment with respect to the member on the back side and the like, the intermediate sheet 40 is preferably fixed to the member adjacent to the back side by a joining method using material fusion such as heat sealing, ultrasonic sealing, or a hot melt adhesive. In the illustrated example, the intermediate sheet 40 is fixed to the surface of the portion of the wrapping sheet 58 on the surface side of the absorbent body 56 by a hot melt adhesive applied to the back surface thereof.

[0132] (Liquid-Impermeable Sheet)

[0133] The material of the liquid-impermeable sheet 11 is not particularly limited, and, for example, a plastic film composed of a polyolefin-based resin such as polyethylene or polypropylene or a laminated nonwoven fabric in which a plastic film is provided on the surface of a nonwoven fabric, a laminated sheet in which a nonwoven fabric is superposed and joined on a plastic film, or the like can be exemplified. The liquid-impermeable sheet 11 preferably uses a material having liquid-impermeability and having moisture permeability, which is preferably used from the viewpoint of preventing stuffiness. As a plastic film having moisture permeability, a microporous plastic film obtained by mixing an inorganic filler in a polyolefin-based resin such as polyethylene or polypropylene, molding the sheet, and then stretching in a uniaxial or biaxial direction is widely used. Furthermore, a nonwoven fabric using microdenier fibers, a nonwoven fabric in which leakproofness is enhanced by reducing fiber voids by applying heat or pressure, a liquid-impermeable sheet formed without using a plastic film by a method of applying a high water absorbent resin or a hydrophobic resin or a water repellent agent, or the like can also be used as the liquid-impermeable sheet 11, but in order to obtain sufficient adhesive strength when adhering to the cover nonwoven fabric 13 described later via a hot melt adhesive, it is preferable to use a resin film.

[0134] The liquid-impermeable sheet 11 can also extend to both side portions of the topsheet 30 side of the absorbent member 50 in addition to being housed in the width of the back side of the absorbent member 50 as illustrated in the drawing, in order to improve leakproofness, by winding around both sides of the absorbent member 50. The width of this extension portion is preferably about 5 to 20 mm on each of the left and right sides.

[0135] (Absorbent Member)

[0136] The absorbent member 50 has an absorbent body 56 and a wrapping sheet 58 that wraps the entire absorbent body 56. The absorbent member 50 has a portion that extends to the crotch portion M and to the front side and the back side of the crotch portion M.

[0137] (absorbent)

[0138] The absorbent 56 can extend across both sides in the front-rear direction LD of the crotch portion M in such a manner as to include the crotch portion M. In the case of a pant-type disposable diaper as in the present example, the absorbent 56 is preferably extended to the peripheral portion of the inlay 200 or the vicinity thereof in the front-rear direction LD and the widthwise direction WD. Note that the reference sign 56X denotes the entire width of the absorbent 56.

[0139] In order to easily ensure the absorption amount of the crotch portion M, the absorbent 56 is preferably substantially rectangular in shape as in the example shown in Figure 8 . In addition, as in the example shown in Figure 12 (a), in order to improve the fit of the crotch portion M, the absorbent 56 of the crotch portion M can be made narrower in width than the two sides thereof in the front-rear direction, and can be formed in a tapered shape. At this time, in order to easily ensure the absorption amount of the crotch portion M, the width n1 of the narrowest portion of the absorbent 56 of the crotch portion M is preferably 0.85 times or more the entire width 56X of the absorbent 56.

[0140] In addition, the crotch portion M refers to the range in the front-rear direction LD including the contraction portion 56n when the absorbent 56 has the contraction portion 56n described later, refers to the range in the front-rear direction LD of the outer shape of the diaper in the expanded state when the absorbent 56 does not have the contraction portion 56n but the outer shape of the diaper in the expanded state has the contraction portion as in the illustrated example, refers to the portion in the front-rear direction LD located in the center when there is no contraction portion, and is the portion in which the dimension in the front-rear direction LD is 20 to 30% of the product length. The portions extending from the crotch portion M to the front side and the rear side become the front side portion and the rear side portion, respectively.

[0141] The absorbent 56 can be a single layer as in Figure 3 and Figure 24 (a), or can be layered with a plurality of layers as in Figure 24 (b) and (c). The layers of the absorbent 56 refer to layers obtained through a fiber accumulation process using a predetermined fiber accumulation roll and a compression process in the thickness direction as needed. Thus, for example, as in Figure 24 (b) and (c), the absorbent 56 can be composed of two layers of an upper layer 56a and a lower layer 56b.

[0142] In addition, the dimensions of the plurality of layers included in the absorbent 56 can be the same as or different from each other. In addition, the thicknesses of the plurality of layers included in the absorbent 56 can be the same as or different from each other. For example, as in Figure 24 (a), the width and the thickness can be different in the upper layer 56a and the lower layer 56b included in the absorbent 56. In Figure 24(b) In the example shown, the upper layer 56a has a smaller width and thickness than the lower layer 56b. The dimensions of the multiple layers included in the absorbent body can be set according to the form and purpose of use of the absorbent article. In addition, the number of layers is not limited to two, and can be three or more.

[0143] The thickness of the absorbent body 56 (the overall thickness of the multiple layers in the case where the absorbent body is composed of multiple layers) can be 0.5 to 30 mm, and preferably 1 to 15 mm. For example, in the case of a disposable paper diaper, the thickness of the absorbent body 56 can be 1 to 30 mm, and preferably 1.5 to 15 mm, and more preferably 5 to 13 mm. In addition, in the case of a sanitary napkin for use in menstruation, the thickness of the absorbent body 56 can be 0.3 to 30 mm, and preferably 1.0 to 15 mm. The thickness of the absorbent body 56 can be uniform, or regions of relatively greater thickness or relatively lesser thickness can be formed.

[0144] The absorbent body 56 is formed by mixing and agglomerating pulp fibers 56f and high-absorbency polymer particles 56p, and the pulp fibers 56f and high-absorbency polymer particles 56p are present substantially uniformly throughout the absorbent body 56, with the high-absorbency polymer particles 56p held between the pulp fibers 56f. Such an absorbent body 56 can be manufactured using a fiber accumulation drum described later. The absorbent body 56 is preferably formed by mixing and agglomerating only the pulp fibers 56f and high-absorbency polymer particles 56p, but can contain, as needed, substances other than the pulp fibers 56f and high-absorbency polymer particles 56p, such as fillers, pigments, sizing agents, coagulants, oil repellents, sulfates, yield improvers, drainage improvers, dry paper strength enhancers, wet paper strength enhancers, coloring pigments, water resistance agents, deodorants, perfumes, and other additives.

[0145] (Pulp fibers)

[0146] Pulp is a collection of fibers (pulp fibers) extracted from wood, grass, or other plants through mechanical and / or chemical treatment. As raw materials for pulp, in addition to coniferous trees and broad-leaved trees, bamboo, rice, kudzu, miscanthus, hemp, sugarcane, and the like can be used. In addition, substances formed from artificial cellulose such as rayon and acetate can be used.

[0147] As the pulp fibers 56f contained in the absorbent 56, it is preferable to contain, in a mixed state, broadleaf tree pulp fibers (pulp fibers derived from a broadleaf tree) and needle leaf tree pulp fibers (pulp fibers derived from a needle leaf tree) having an average fiber length longer than that of the broadleaf tree pulp fibers, or the like, and it is also possible to contain only the broadleaf tree pulp fibers (100% broadleaf tree pulp fibers). Hereinafter, such an absorbent 56 will also be referred to as an absorbent containing broadleaf tree pulp fibers. The broadleaf tree pulp fibers are preferably broadleaf tree bleached kraft pulp (LBKP) produced by a kraft process. In addition, the needle leaf tree pulp fibers are preferably needle leaf tree bleached kraft pulp (NBKP) produced by a kraft process.

[0148] The content of the needle leaf tree pulp fibers and the broadleaf tree pulp fibers in the entire pulp fibers 56f is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and still further preferably 98% by mass or more. In addition, it is preferable that the entire pulp fibers 56f consist essentially of the needle leaf tree pulp fibers and the broadleaf tree pulp fibers. In addition, in the present specification, the content of the pulp fibers 56f or the material thereof, unless otherwise specified, means the absolute dry content, that is, the mass ratio in the absolute dry state.

[0149] As shown in Table 1, in the case of (I) the absorbent 56 consisting of the needle leaf tree pulp fibers, since the fiber length and the fiber width of the pulp fibers 56f are large, and the deviation of the fiber length and the fiber width is also large, the distance between the pulp fibers 56f is generally large, and the volume of the obtained absorbent 56 is large. Therefore, the absorption capacity (water absorption amount) of the pulp fibers 56f is large, and the absorption speed of the absorbent 56 is also relatively fast. However, since the distance between the pulp fibers 56f is large, the liquid retention capacity of the fibers caused by the capillary phenomenon is relatively low, and furthermore, the needle leaf tree pulp fibers are likely to fall along the direction of gravity, and the needle leaf tree pulp fibers are slightly poor in the retention of the superabsorbent polymer particles (SAP) between the pulp fibers 56f. As a result, compared with the absorbents 56 of (II) and (III) described below, the liquid retention capacity of the absorbent 56 is reduced, and the effect of suppressing the backflow of the liquid is low.

[0150] [Table 1]

[0151]

[0152] In addition, in the absorbent body 56 of (II) composed of broadleaf tree pulp fibers, the fiber length and the fiber width of the pulp fibers 56f are relatively small, and the variation in the fiber length and the fiber width is also relatively small, so the distance between the pulp fibers 56f is reduced, and the fiber density of the obtained absorbent body 56 is also increased. Therefore, the absorbent capacity (water absorption amount) of the pulp fibers 56f is small, and the absorption speed of the absorbent body 56 or the absorbent article is slow. However, since the distance between the pulp fibers 56f is small, the liquid retention capacity of the fibers caused by the capillary phenomenon is high. In addition, the retention of the superabsorbent polymer particles 56p between the pulp fibers 56f is substantially good, and the liquid retention capacity of the superabsorbent polymer particles 56p is higher than that of the absorbent body 56 of (I). Therefore, the liquid retention capacity of the absorbent body 56 is higher than that of the absorbent body 56 of (I), and also has the effect of suppressing backflow of the liquid.

[0153] (III) In the absorbent body 56 composed of coniferous tree pulp fibers and broadleaf tree pulp fibers, fibers having a long fiber length and a large fiber width as described above are combined with fibers having a short fiber length and a small fiber width, so that the fiber density is intermediate between (I) and (II). Therefore, the absorbent capacity of the fibers can be ensured to some extent, the absorption speed of the absorbent body 56 can be maintained, and the liquid retention capacity of the fibers due to the capillary phenomenon can also be ensured. In addition, the retention of the superabsorbent polymer particles 56p between the pulp fibers 56f is also good, and the liquid retention capacity of the superabsorbent polymer particles 56p can be further improved with respect to (I) and (II). Therefore, the absorbent capacity and the absorption speed of the absorbent body 56 can be maintained, and the liquid retention capacity can also be obtained. In this way, in the mode of (III), by ensuring both the absorbent capacity, the absorption speed, and the liquid retention capacity, the backflow prevention property can be improved.

[0154] In addition, in the above (III), by containing coniferous tree pulp fibers, the bulkiness of the absorbent body 56 can be ensured to some extent, so that the skin feel of the obtained absorbent article can be suppressed from being poor. In addition, by containing coniferous tree pulp fibers, the operability when fluff pulp is made from pulp sheets (i.e., the effect of suppressing scattering of powdery bodies and suppressing attachment of fibers to devices) can also be ensured. Good operability contributes to overall high productivity of the absorbent article manufacturing.

[0155] In a preferred example of the absorbent body 56 containing hardwood pulp fibers, the proportion of pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm is 40% or more by mass, and the proportion of pulp fibers having a fiber width of 10 μm or more and less than 35 μm is 90% or more by mass, in all the pulp fibers of the absorbent body 56. In addition, the proportion of the above-mentioned pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm can be preferably 42.6% or more, more preferably 43% or more, and further preferably 43.2% or more, 43.7% or more, or 45 or more. In addition, the proportion of the above-mentioned pulp fibers having a fiber width of 10 μm or more and less than 35 μm can be preferably 90.6% or more, more preferably 91.0% or more, and further preferably 91.2% or more, or 91.4% or more. In this way, by the absorbent body 56 containing the specific pulp fiber length and the specific pulp fiber width within the specific ranges, respectively, the above-mentioned (III) advantage of the absorbent body 56 (particularly, the backside leakage prevention property) can be further improved, and the reliability can be improved.

[0156] In the absorbent body 56 containing hardwood pulp fibers, the upper limit of the proportion of pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm in all the pulp fibers 56f of the absorbent body 56 is not particularly limited, but can be 80 mass% or less, 60 mass% or less, or 55 mass% or less, in consideration of the deviation of the fiber length due to the fact that the pulp is a natural material. In addition, likewise, the upper limit of the proportion of pulp fibers having a fiber width of 10 μm or more and less than 35 μm is not particularly limited, and can be 98 mass% or less, 95 mass% or less, or 94 mass% or less.

[0157] In addition, the fiber length and the fiber width of the pulp fibers can be measured using a measuring machine "VALMET FS5" in accordance with JIS-P8226:2011 (ISO 16065-2:2007) "Pulp - Method of determination of fiber length by automated optical analysis".

[0158] In addition, in the absorbent body 56 containing hardwood pulp fibers, the average fiber length when the pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm are measured at intervals of 0.02 mm (at a classification width of 0.02 mm) can be 0.5 to 0.8 mm, and is preferably 0.6 to 0.7 mm. Due to this, in the absorbent body 56, the pulp fibers can suppress the uneven distribution of the voids depending on the orientation direction thereof, and the absorption speed can be ensured.

[0159] Further, in the absorbent 56 containing the hardwood pulp fibers, the standard deviation σ when the pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm are measured at intervals of 0.02 mm (at a classification width of 0.02 mm) can be 0.58 mm or less, preferably 0.56 mm or less, more preferably 0.54 mm or less, and further preferably 0.50 mm or less. By setting the standard deviation within the above range, improvement in the absorption capacity and the absorption speed of the absorbent 56 and improvement in the anti-rewet property can be achieved.

[0160] Further, when the pulp fibers having a fiber width of 10 μm or more and less than 35 μm are measured at intervals of 1 μm (at a classification width of 1 μm), the average fiber width can be 15 μm or more and 30 μm or less, and preferably 18 μm or more and 27 μm or less. By setting the average fiber width within the above range, the voids between the fibers can be moderately maintained, the decrease in the absorption speed can be prevented, and at the same time, the contact area between the pulp fibers can be prevented from being excessively large, and the bonding force between the fibers can be prevented from being excessively high. Thus, the defibrating property at the time of production can be appropriately set. Further, in the case where the defibrating property of the pulp sheet is excessively low, the pulp fibers can be excessively defibrated (defibration is excessively performed) at the time of production of the fluff pulp, and fine fibers can be generated, which can decrease the absorption speed of the obtained absorbent.

[0161] The standard deviation σ when the pulp fibers having a fiber width of 10 μm or more and less than 35 μm are measured at intervals of 1 μm (at a classification width of 1 μm) can be 2.9 μm or less, preferably 2.8 μm or less, more preferably 2.75 μm or less, and further preferably 2.6 μm or less, 2.59 μm or less. By setting the standard deviation within the above range, improvement in the absorption speed and the anti-rewet property can be achieved.

[0162] As described above, the absorbent 56 containing the hardwood pulp fibers in which the fiber length distribution in a specific range and the fiber width distribution in a specific range are reduced, can ensure the absorption capacity and the absorption speed even when the hardwood pulp fibers are mixed, and has a good anti-rewet property.

[0163] The raw material wood of the softwood pulp fibers contained in the pulp fibers is not particularly limited, but coniferous trees such as pine and various kinds of fir are preferably used.

[0164] In addition, the raw wood material of the broadleaf tree pulp fiber is not particularly limited, and an acacia material, an eucalyptus material, or the like is suitably used. The acacia material is a material having characteristics of less shrinkage due to drying, high impact resistance, and high strength, and the pulp obtained from the acacia material also inherits the original properties, and has high water absorption and drying properties, and is a useful raw material pulp. The eucalyptus material belongs to the Eucalyptus genus, and among them, Eucalyptus globulus, Eucalyptus grandis, Eucalyptus urophylla, Eucalyptus nitens, and Eucalyptus regnans, and the like have been widely used as a raw material pulp for papermaking since ancient times, and the pulp fiber made of such wood has characteristics of high pressure resistance of the fiber lumen and high stiffness, and by using the pulp fiber, it is possible to realize high bulkiness and low density of the absorbent. As the broadleaf tree pulp fiber, the acacia material has higher bulkiness than the eucalyptus material because the fiber width is larger, and even when the absorbent is compounded with the needle leaf tree pulp fiber, the reduction in the absorption capacity and the absorption rate is small, and thus the acacia material is preferable.

[0165] The mass ratio of the broadleaf tree pulp fiber to other pulp fibers such as the needle leaf tree pulp fiber in the absorbent 56 containing the broadleaf tree pulp fiber is not limited, and for example, it can be set to 10 / 90 to 90 / 10, and from the viewpoint of operability, it is preferably 20 / 80 to 50 / 50, more preferably 25 / 75 to 38 / 62, further preferably 25 / 75 or more and less than 38 / 62, further preferably 26 / 74 to 36 / 64, and particularly preferably 28 / 72 to 35 / 65.

[0166] In addition, in the content of the acacia material in the raw wood material of the broadleaf tree pulp fiber, that is, in the absorbent 56 containing the broadleaf tree pulp fiber, the proportion of the pulp fiber derived from the acacia material in the total amount of the broadleaf tree pulp fiber can be set to be preferably 5 to 95% by mass, more preferably 5% by mass or more and less than 95% by mass, more preferably 20 to 93% by mass, 20 to 90% by mass, 25 to 85% by mass, or 50 to 80% by mass. Even the broadleaf tree pulp fiber, which has a short fiber length and in which the fibers are easily densely packed compared to the needle leaf tree pulp fiber, and regardless of the orientation of the fiber in which direction (for example, in which of the length direction, the width direction, and / or the thickness direction of the obtained absorbent article), it is possible to more uniformly ensure the gaps between the fibers.

[0167] As the pulp fibers constituting the absorbent 56, in addition to the above-mentioned softwood bleached kraft pulp and hardwood bleached kraft pulp, for example, soda pulp, sulfite pulp, chemi-thermomechanical pulp, chemi-mechanical pulp, thermo-chemi-mechanical pulp, and the like can be used. However, in a case where the lignin in the fibers cannot be sufficiently removed, the absorption amount and the absorption speed of the pulp fibers tend to decrease, and thus a bleached pulp in which the lignin is sufficiently removed is preferable. When the above-mentioned other pulp is contained, the content of the above-mentioned other pulp is preferably 10% by mass or less with respect to the entire pulp raw material.

[0168] In addition, in the pulp fibers 56f contained in the absorbent 56, regenerated pulp fibers (recycled pulp fibers) of any kind can be contained. For example, the pulp fibers 56f can contain recycled softwood pulp fibers and recycled hardwood pulp fibers. In a case where recycled pulp fibers are used, the amount of ash in the pulp fibers used for the absorbent is preferably as little as possible, and the amount of ash in the fluff pulp is preferably as little as possible. In addition, in a case where recycled pulp fibers are used, when comparing the pulp from the same raw material before and after recycling, the whiteness of the recycled pulp can be lower than the whiteness of the original pulp (unregenerated pulp or unrecycled pulp), can be the same, and is preferably the same.

[0169] In a case where the absorbent 56 is multilayered, only a part thereof can contain the hardwood pulp fibers, or all of them can contain the hardwood pulp fibers. For example, in a case where the absorbent 56 is composed of two layers of the upper layer 56a and the lower layer 56b, only the lower layer 56b can contain the hardwood pulp fibers, or only the upper layer 56a, which can be in direct contact with the skin, can contain the hardwood pulp fibers.

[0170] In addition, the weight per unit area of the pulp fibers 56f in the absorbent 56 (the weight per unit area of the entire multilayer in a case where the absorbent is multilayered) differs depending on the product use, and can be 100 to 500 g / m2, preferably 100 to 300 g / m2, and particularly preferably 120 to 250 g / m2. For example, in a case of a disposable diaper, the weight per unit area of the pulp fibers can be 100 to 300 g / m2, and preferably 120 to 200 g / m2. In addition, for example, in a case of a sanitary napkin for menstruation, the weight per unit area of the pulp fibers in the absorbent 56 (the weight per unit area of the entire multilayer in a case where the absorbent is multilayered) can be 150 to 500 g / m2, and preferably 250 to 400 g / m2. The weight per unit area of the pulp fibers can be uniform throughout, or a region of relatively high weight per unit area or a region of relatively low weight per unit area can be formed. 2 2 2 2 2 2 2 The weight per unit area of the pulp fibers can be uniform throughout, or a region of relatively high weight per unit area or a region of relatively low weight per unit area can be formed.

[0171] ​​​​​​(highly absorbent polymer particles)

[0172] The highly absorbent polymer particles 56p include "powder" in addition to "particles". As the highly absorbent polymer particles 56p, particles used in such disposable paper diapers as they are can be used. The pre-swelling particle diameter (particle diameter before absorption of liquid) of the highly absorbent polymer particles 56p is not particularly limited, and highly absorbent polymer particles 56p having a pre-swelling particle diameter of more than 150 μm and 850 μm or less are preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more of the total amount. In addition, highly absorbent polymer particles 56p having a pre-swelling particle diameter (for example, 600 μm or less, more preferably 500 μm or less) that is shorter than the average fiber length of broadleaf tree pulp fibers are preferably 60% by mass or more, more preferably 70% by mass or more, and particularly preferably 80% by mass or more of the total amount.

[0173] A standard sieve (for example, manufactured by Tokyo Screen Co., Ltd.) having a mesh size of 850 μm, 600 μm, 500 μm, 355 μm, 300 μm, 250 μm, or 150 μm and a tray are sequentially arranged from the top in a shaker (for example, manufactured by Retsch Co., Ltd., AS200), all of the highly absorbent polymer particles are put into the uppermost sieve, and sieving is performed to obtain the particle size distribution of the highly absorbent polymer particles 56p. The shaking conditions are 50 Hz, an amplitude of 0.5 mm, and a shaking time of 10 minutes. In addition, the sieving is performed in an environment of a temperature of 23 ± 2°C and a humidity of 50 ± 5%, and the measurement is performed after the sample is stored in the same environment for 24 hours or more before the sieving. The sieving is performed three times, and the average of the three times is used as the mass on each sieve. From the mass of the highly absorbent polymer particles on each sieve and the total mass (mass of all of the highly absorbent polymer particles) obtained, the content ratio (mass percentage) of the particle diameter range corresponding to each sieve (i.e., more than 850 μm, more than 600 μm and 850 μm or less, more than 500 μm and 600 μm or less, more than 355 μm and 500 μm or less, more than 300 μm and 355 μm or less, more than 250 μm and 300 μm or less, more than 150 μm and 250 μm or less, and 150 μm or less) can be obtained. In addition, if the particle size cumulative curve is obtained based on the particle size distribution, the average particle diameter is obtained as the particle diameter corresponding to the central cumulative value (50%) of the cumulative curve, and the average particle diameter of the highly absorbent polymer particles is preferably in the range of 355 to 500 μm, and more preferably in the range of 370 to 470 μm.

[0174] The materials used for the highly absorbent polymer particles 56p can be used without particular limitations, but materials with a water absorption capacity of 40 g / g or more are preferred. The highly absorbent polymer particles 56p can be starch-based, cellulose-based, or synthetic polymer-based (polyacrylate-based, polysulfonate-based, maleic anhydride-based), etc., and can include starch-acrylate (salt) graft copolymers, starch-acrylonitrile copolymer saponifications, sodium carboxymethyl cellulose crosslinks, or acrylate (salt) polymers. The shape of the highly absorbent polymer particles 56p is preferably a commonly used powder or granular form, but other particle shapes can also be used.

[0175] As for the highly absorbent polymer particles 56p, it is preferable to use particles with an absorption rate of 70 seconds or less, especially 40 seconds or less. If the absorption rate is too slow, backflow (the liquid supplied to the absorbent 56 returns to the outside of the absorbent 56) is likely to occur.

[0176] Furthermore, it is preferable to use particles with a gel strength of 1000 Pa or higher as the highly absorbent polymer particles 56p. This effectively suppresses the stickiness after liquid absorption, even when a swollen absorbent body 56 is formed.

[0177] The area weight per unit area of ​​the highly absorbent polymer particles 56p can be appropriately determined according to the absorption capacity required for the application of the absorber 56. Therefore, although it cannot be generalized, the area weight per unit area of ​​the highly absorbent polymer particles 56p in the absorber 56 (when the absorber 56 is composed of multiple layers, it is the area weight per unit area of ​​the entire multilayer structure) can be 50~350 g / m³. 2 Preferably, it is 100~300 g / m 2 For example, in the case of disposable diapers, the area weight of the superabsorbent polymer particles 56p is 50~300 g / m². 2 Preferably, it is 100~250 g / m 2 Additionally, for example, in the case of sanitary napkins, the area weight per unit area of ​​the highly absorbent polymer particles 56p in the absorbent body 56 (or the area weight per unit area of ​​the entire multilayer structure when the absorbent body 56 is composed of multiple layers) can be 70~470 g / m². 2 The preferred value is 140 to 240. When the absorber 56 has two layers, the area weight per unit area of ​​the highly absorbent polymer particles 56p in the lower layer 56b can be different from that in the upper layer 56a. That is, the area weight per unit area of ​​the highly absorbent polymer particles 56p in the lower layer 56b can be greater than that in the upper layer 56a, and conversely, the area weight per unit area of ​​the highly absorbent polymer particles 56p in the lower layer 56b can be less than that in the lower layer 56a.

[0178] The ratio of pulp fiber 56f to superabsorbent polymer particles 56p in absorbent 56 is not particularly limited. For example, the weight ratio of pulp fiber 56f to superabsorbent polymer particles 56p can be 40:60 to 65:35.

[0179] The average particle size of the superabsorbent polymer particles 56p after swelling is preferably 2,000 to 3,000 μm, more preferably 2,200 to 2,800 μm. The average particle size of the superabsorbent polymer particles 56p after swelling refers to the average diameter of the particles in a swollen state after immersion in physiological saline for 60 minutes and followed by 15 minutes of dehydration. This average diameter is obtained by observing the swollen superabsorbent polymer particles 56p group from one direction at 50x magnification using a microscope, measuring the maximum diameter of any 20 particles appearing on the entire surface of the superabsorbent polymer particles 56p group, and taking the arithmetic mean. In particular, when the average particle size of the superabsorbent polymer particles 56p after swelling is greater than the average fiber length of the hardwood pulp fibers, the interweaving between the pulp fibers 56f is easily cut due to the expansion of the superabsorbent polymer particles 56p, thus making it difficult to hinder the expansion of the superabsorbent polymer particles 56p (making so-called gel blockage less likely), which is therefore preferable.

[0180] (Low weight per unit area)

[0181] Absorber 56 can be like Figures 1-4 As shown in the example, the crotch area M has elongated low-weight-per-unit-area portions 56L extending in the front-rear direction LD on both sides of the width direction WD. Although not shown, these low-weight-per-unit-area portions 56L may not be present. The low-weight-per-unit-area portion 56L refers to a portion with a lower weight per unit area, excluding portions like the high-compression portion 51 described later, which are compressed only along the thickness direction TD and have a constant weight per unit area. The low-weight-per-unit-area portion 56L can also be a slit extending in the thickness direction TD, but if it is a recess with a low aggregation of pulp fibers and highly absorbent polymer particles, as shown in the example, it is easier to ensure absorption, and therefore preferred. This recess can be formed on either the surface or the back side of the absorbent 56. By providing such a low-weight-per-unit-area portion 56L on the absorbent 56, the absorbent 56 is encouraged to bend along the low-weight-per-unit-area portion 56L, improving the fit of the absorbent 50 in the crotch area M. The total unit area weight of pulp fibers and superabsorbent polymer particles in the low unit area weight section 56L only needs to be less than the total unit area weight of pulp fibers and superabsorbent polymer particles in the parts other than the low unit area weight section 56L. For example, it can be 0.1 to 0.5 times the total unit area weight of pulp fibers and superabsorbent polymer particles in the parts other than the low unit area weight section 56L.

[0182] The low-area-weight portion 56L can extend linearly in the front-rear direction LD, or can be curved so as to be located laterally toward the front-rear direction LD as shown in the illustrated example, as long as it is elongated in the front-rear direction LD. The front-rear ends of the low-area-weight portion 56L can be shaped as appropriate, for example, in addition to being linear as in the example shown in Figure 12 (a), it can be shaped so as to expand in a curved shape (semicircular arc shape, etc.) as in the example shown in Figure 8 , although not shown, the corners of the ends can be rounded and the middle portion can be linear. The width m1 of the low-area-weight portion 56L can be determined as appropriate, for example, it can be 0.04 to 0.1 times the width n1 (in the case of a rectangular shape, it means the full width 56X) of the narrowest portion in the crotch portion M of the absorbent body 56. The width m1 of the low-area-weight portion 56L can be constant in the length direction thereof, or can vary. The size and arrangement of the front-rear direction LD of the low-area-weight portion 56L can be determined as appropriate. For example, the size m2 of the front-rear direction LD of the low-area-weight portion 56L can be 50 to 120%, more preferably 50 to 80%, of the size of the front-rear direction LD of the crotch portion M. In addition, the low-area-weight portion 56L can be contained within the range of the crotch portion M, or can extend to the front side, the rear side, or both sides of the crotch portion M.

[0183] As shown in Figure 8 , one low-area-weight portion 56L is provided on each of the two sides in the width direction WD of the crotch portion M, and one is provided in the center in the width direction WD, in addition, as shown in Figure 12 (a), only one can be provided in the center, or as shown in Figure 12 (b), only one can be provided on each of the two sides in the width direction WD of the crotch portion M.

[0184] (High compression portion)

[0185] In the absorbent member 50, as shown in Figure 3 , Figure 4 , Figures 9-11As shown, the plurality of high compression portions 51 are provided at intervals in the thickness direction TD compressed in a manner that is recessed from the surface of the absorbent member 50 into the absorbent body 56. Further, in the arrangement region (a rectangular region formed by edges along the front-rear direction LD and the width direction WD, a rectangular region circumscribing the entire high compression portion 51) of the plurality of high compression portions 51, the portion other than the high compression portion 51 is a non-high compression portion 52 that is thicker and lower in density than the high compression portion 51. The high compression portion 51 is a high density portion compressed by pressing (directly applying pressure) in a manner that is approximately equal in thickness, and is the bottom of the recess. On the other hand, the non-high compression portion 52 is a portion that is thicker and lower in density than the high compression portion 51, but even in the vicinity of the periphery of the high compression portion 51, the absorbent body 56 is deformed in a manner that is stretched by the deformation of the high compression portion 51, as a result of which the density increases as it approaches the high compression portion 51. The non-high compression portion 52, as long as it is thicker and lower in density than the high compression portion 51, can be compressed in the thickness direction TD by a portion or all of it simultaneously with, or prior to or subsequent to, the formation of the high compression portion 51. The non-high compression portion 52 preferably does not have a recess on either or both of the surface and the back surface of the absorbent member 50.

[0186] The high compression portion 51 can be provided only in a portion of the front-rear direction or a portion of the width direction of the absorbent member 50, in addition to being provided throughout the front-rear direction and the width direction of the absorbent member 50 (i.e., the entire surface of the absorbent member 50 becomes the arrangement region of the high compression portion 51). For example, although not shown, the high compression portion 51 can be provided only in the middle region of the front-rear direction LD including the crotch portion M, or conversely, the high compression portion 51 can not be provided in the middle region of the front-rear direction LD including the crotch portion M, but can be provided only in the regions on both sides thereof in the front-rear direction. Further, the high compression portion 51 of the illustrated example does not recess from the surface of the sheet (top sheet 30 and middle sheet 40 in the case of the illustrated example) on the surface side of the absorbent member into the absorbent body 56, but is pressed in a manner that is recessed from the sheet on the surface side of the absorbent member 50 into the absorbent body 56, as a result of which it can recess from the surface of the absorbent member 50 into the absorbent body 56.

[0187] The density of the absorbent body 56 in the high compression portion 51 is not particularly limited, and is preferably 60,000 to 250,000 g / m 3 , more preferably 65,000 to 200,000 g / m 3 . On the other hand, the density of the absorbent body 56 in the non-high compression portion 52 is not particularly limited, and is preferably 50,000 to 200,000 g / m 3 , more preferably 55,000 to 150,000 g / m 3 . The density of the absorbent body 56 in the high compression portion 51 and the non-high compression portion 52 is measured by the following method.

[0188] Method for measuring density of absorbent 56 in high compression portion 51

[0189] (1) The sheet on at least one of the front side and the back side of the absorbent 50 is peeled off in such a manner that the face having the high compression portion 51 of the absorbent 50 is exposed, and the area of the high compression portion 51 is measured by the method described later.

[0190] (2) The weight per unit area of the absorbent 50 is measured.

[0191] (3) A part of the wrapping sheet 58 is cut off from the absorbent 50, and the weight per unit area of the wrapping sheet 58 is measured.

[0192] (4) The mass of the absorbent 50 in the high compression portion 51 is calculated from the measurement results of (1) and (2) above, the mass of the wrapping sheet 58 in the high compression portion 51 is calculated from the measurement results of (1) and (3) above, and the mass of the absorbent 56 in the high compression portion 51 is calculated by subtracting the latter from the former.

[0193] (5) The absorbent 50 is frozen with liquid nitrogen, and then cut in the thickness direction TD in such a manner that the approximate center of the high compression portion 51 is cut, and the cut surface is observed with a microscope to measure the thickness of the absorbent 56.

[0194] (6) The thickness of the absorbent 56 in the high compression portion 51 is assumed to be constant, and the volume of the absorbent 56 in the high compression portion 51 is calculated by multiplying the area of the high compression portion 51 in (1) above by the thickness of the absorbent 56 in (5) above.

[0195] (7) The density of the absorbent 56 in the high compression portion 51 is calculated by dividing (4) above by (6) above.

[0196] Method for measuring density of absorbent in non-high compression portion

[0197] (1) The sheet on at least one of the front side and the back side of the absorbent 50 is peeled off in such a manner that the face having the non-high compression portion 52 of the absorbent 50 is exposed, and a measurement target region of a rectangular shape of a prescribed size is marked on the non-high compression portion 52 using a pen. The size of the measurement target region is measured, and the area is calculated.

[0198] (2) The weight per unit area of the absorbent 50 is measured.

[0199] (3) A part of the wrapping sheet 58 is cut off from the absorbent 50, and the weight per unit area of the wrapping sheet 58 is measured.

[0200] (4) The mass of the absorbent member 50 in the measurement target region is found from the measurement result of the above (1) (2), the mass of the wrapping sheet 58 in the measurement target region is found from the measurement result of the above (1) (3), and the mass of the absorbent body 56 in the measurement target region is found by subtracting the latter from the former.

[0201] (5) After the absorbent member 50 is frozen with liquid nitrogen, it is cut in the thickness direction TD so as to measure the approximate center of the measurement target region, and the cut surface is observed with a microscope to measure the thickness of the absorbent body 56.

[0202] (6) Assuming that the thickness of the absorbent body 56 in the measurement target region is constant, the volume of the absorbent body 56 in the measurement target region is found by multiplying the area of the measurement target region of the above (1) by the thickness of the absorbent body 56 of the above (5).

[0203] (7) The density of the absorbent body 56 in the non-high compression portion 52 is found by dividing the above (4) by the above (6).

[0204] In addition, the area of each high compression portion 51 is not particularly limited, but is preferably 2 to 25 mm 2 left and right, and particularly preferably 3 to 15 mm 2 .

[0205] The high compression portion 51 is a high-density portion whose thickness is substantially equal by being compressed in the thickness direction TD by pressing (directly applying pressure), and is the bottom of a recessed portion recessed from the surface of the back of the absorbent member 50. Such a high-density portion has the property that the intertwining of fibers is difficult to break even if it swells due to absorption of liquid. On the other hand, the non-high compression portion 52 is a portion that is thicker and lower in density than the high compression portion 51, but even in the vicinity of the high compression portion 51 of the non-high compression portion 52, the absorbent body 56 is deformed in a manner stretched by the deformation of the high compression portion 51, as a result of which the density increases as it gets closer to the high compression portion 51. Therefore, in the high compression portion 51, capillary phenomenon is strongly exhibited, not only the liquid retention property is higher than the surrounding, but also liquid is sucked toward the high compression portion 51. Therefore, when each high compression portion 51 having a certain degree of density and area is provided at intervals, in the absorbent body 56 containing broadleaf tree pulp fibers, the strength of the absorbent body 56 after absorption of liquid is difficult to decrease, and at the same time, the suction force generated by capillary phenomenon acts on more excreted liquid, and the excreted liquid absorbed by the absorbent body 56 is more widely spread.

[0206] Although not illustrated, the high compression portions 51 can also be compressed in the thickness direction TD so as to be recessed from both the front and back surfaces of the absorbent member 50 into the absorbent body 56, or so as to be recessed from only the back surface of the absorbent member 50 into the absorbent body 56, in which case a recess is formed on the back surface of the absorbent member 50. However, as illustrated in the illustrated example, if the high compression portions 51 are compressed in the thickness direction TD so as to be recessed from at least the front surface of the absorbent member 50 into the absorbent body 56, both the barrier properties and the spreading properties are improved. That is, as described above, in the high compression portions 51, the capillary phenomenon is strongly exhibited, and not only the liquid retention properties are higher than the surrounding portions, but also the liquid is not only absorbed toward the high compression portions 51, but also the excreted liquid collected by the high compression portions 51 is strongly held in portions away from the skin. As a result, backflow is difficult to occur.

[0207] Further, the shortest distance d4 to the closest other high compression portion 51 can be about 1 to 4 mm, and more preferably about 1.5 to 3.5 mm. In this way, when the high compression portions 51 are provided at a certain degree of close intervals, the strength of the absorbent body 56 after absorption of liquid is difficult to decrease, and the attractive force generated by the capillary phenomenon acts on more of the excreted liquid, and the excreted liquid absorbed by the absorbent body 56 spreads more widely. Further, when the high compression portions 51 having a certain degree of area are provided at such intervals, in the high compression portions 51, the distance between the pulp fibers 56f is contracted, thereby resulting in reinforcement of the entanglement of the pulp fibers 56f, reduction of the gaps of the pulp fibers 56f as the movement paths of the superabsorbent polymer particles 56p, increase of the contact portions of the pulp fibers 56f with respect to the superabsorbent polymer particles 56p, and the like, and thus, the movement of the superabsorbent polymer particles 56p within the absorbent body 56 and the movement of the superabsorbent polymer particles 56p outside the absorbent body 56 can be suppressed. That is, the retention properties of the superabsorbent polymer particles 56p in the absorbent body 56 containing the broadleaf tree pulp fibers are improved.

[0208] The area ratio of the high compression portions 51 in the arrangement region of the high compression portions 51 (the sum of the areas of the high compression portions 51 / the area of the arrangement region of the high compression portions 51) is preferably 10 to 35%, and more preferably 20 to 35%. Further, the diameter of the largest inscribed circle 54 inscribed in the outer shape of the non-high compression portions 52 is preferably 30 mm or less, more preferably 10 mm or less, more preferably 6.5 mm or less, further preferably 6 mm or less, and particularly preferably 5 mm or less. Furthermore, the lower limit of the diameter of the largest inscribed circle 54 inscribed in the outer shape of the non-high compression portions 52 is preferably 2 mm, more preferably 3 mm, and particularly preferably 4 mm.

[0209] Thus, if the high compression portions 51 are particularly densely arranged, the liquid diffusibility described above can be further improved. In addition, the holding property of the high-absorbency polymer particles 56p is further improved. Furthermore, even in the vicinity of the high compression portions 51 of the non-high compression portions 52, the absorbent 56 is deformed in a manner stretched by the deformation of the high compression portions 51, and as a result, the absorbent 56 is thinned compared to the case where there are no high compression portions 51. From these viewpoints, it is particularly preferable that the area ratio of the high compression portions 51 be within the range described above. In addition, in order not to make the arrangement of the high compression portions 51 sparse (the non-high compression portions 52 do not continue long in all directions), it is particularly preferable that the diameter of the largest inscribed circle 54 inscribed in the outer shape of the non-high compression portions 52 be small.

[0210] The size and shape of the high compression portions 51 can be appropriately determined. However, since the high compression portions 51 are hard portions, if the size of the high compression portions 51 is too large, or the shape of the high compression portions 51 is too long in one direction, or has an outer shape that is too staggered, there is a possibility that the softness of the absorbent 56 as a whole is insufficient, and a skin feel like a foreign substance (foreign body sensation) is generated in the absorbent 56. In addition, if the size of the high compression portions 51 is too small, or the shape of the high compression portions 51 is too long in one direction, or has an outer shape that is too staggered, in the case where the wrapping sheet 58 is a crepe paper, there is also a problem that the wrapping sheet 58 is easily broken. Therefore, the diameter of the largest inscribed circle 53 inscribed in the outer shape of the high compression portions 51 is preferably 1 to 10 mm, more preferably 1 to 6 mm, further 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 portions 51 is preferably 1 to 15 times, more preferably 1 to 5 times, further preferably 1.0 to 2.5 times, further preferably 1.0 to 2.0 times, and particularly preferably 1.0 to 1.6 times the circumference of the largest inscribed circle 53 inscribed in the outer shape of the high compression portions 51.

[0211] As an example, the major axis d1 (the length of the long side of the smallest circumscribed rectangle) of each high compression portion 51 can be about 4 to 9 mm, and the minor axis d2 (the length of the short side of the smallest circumscribed rectangle) can be about 2 to 5 mm. In the case where the lengths of the four sides of the smallest circumscribed rectangle with respect to each high compression portion 51 are equal, the length d3 of the side can be about 2 to 5 mm.

[0212] The shortest dimension of each high compression portion 51 is not particularly limited, but is preferably longer than the average fiber length of the hardwood pulp fibers, more preferably 4 times or more, further preferably 4 to 10 times, and particularly preferably 4 to 12 times. If the shortest dimension of each high compression portion 51 is longer than the average fiber length of the hardwood pulp fibers, the uneven distribution of the pulp is less likely to occur, and the shape retention of the absorbent body can be improved. In addition, the shortest dimension of each high compression portion 51 is preferably longer than the average particle diameter of the superabsorbent polymer particles 56p after swelling, more preferably 1.5 times or more, further preferably 1.5 to 6 times, and particularly preferably 1.5 to 5 times. If the shortest dimension of each high compression portion 51 is longer than the average particle diameter of the superabsorbent polymer particles 56p after swelling, the retention of the superabsorbent polymer particles is improved, and the uneven distribution of the absorbency can be reduced.

[0213] The outer shape of the high compression portion 51 is not particularly limited, and is preferably a shape having no inflection point and bending point, such as a circle, an ellipse, a rounded rectangle (including a shape in which the opposite sides of any one of the sides are not straight lines but are each a semicircle), but can be a triangle or a quadrangle, a cloud shape, an X shape, a V shape, a U shape, or the like.

[0214] Generally, to improve the liquid leakage resistance, the mixing ratio of the superabsorbent polymer particles having high liquid retention is increased. In recent years, however, the mixing ratio of the superabsorbent polymer particles is increased for the purpose of thinning the absorbent body 56 and the like. However, if the mixing ratio of the superabsorbent polymer particles is increased, not only the shape retention of the high compression portion 51 is reduced, but also the absorbent body 56 is less likely to be deformed by being stretched by the deformation of the high compression portion 51 around the high compression portion 51 in the non-high compression portion 52, and the liquid leakage resistance and the diffusion property can be less likely to be improved. In addition, the superabsorbent polymer particles expanded by absorbing the excreted liquid are likely to be in close contact with each other, and a phenomenon in which the diffusion of the excreted liquid is hindered (gel blocking) is likely to occur, and thus the diffusion property can be less likely to be improved. Therefore, in a case where the unit area weight of the pulp fibers in the absorbent body 56 is 100 to 500 g / m 2 , the weight ratio of the pulp fibers to the superabsorbent polymer particles in the absorbent body 56 is preferably 45 : 55 to 65 : 35.

[0215] The thickness 50t of the absorbent 50 and the thickness 51t of the high-compression section 51 can be appropriately determined, but if the compression is insufficient, it may be difficult to improve the low backflow and diffusion properties. Therefore, when using the above-mentioned range of the unit area weight of pulp fibers and the range of the ratio of pulp fibers to highly absorbent polymer particles, the thickness 50t of the absorbent 50 (the thickness of the non-high-compression section 52) is preferably 3 to 13 mm. At this time, the thickness 51t of the high-compression section 51 (the minimum value when the thickness varies) can be appropriately determined, but in general, it is preferably 60 to 90% of the thickness 50t of the absorbent 50.

[0216] The high-compression section 51 can be arranged in a suitable regular or irregular pattern. For example, the high-compression section 51 can be exemplified as follows: Figure 17 The high-pressure sections 51, arranged in a grid pattern, are shown as dotted lines, or as... Figure 18 and Figure 19 The dotted high-pressure portions 51 shown are arranged in a houndstooth and matrix pattern, as well as... Figure 20 The X-shaped high-compression portions 51 shown are arranged in a matrix or similar pattern. Alternatively, although not shown, the high-compression portions could be arranged in a grid pattern of continuous straight lines, or in a pattern where high-compression portions of different sizes or shapes are spaced apart to represent a predetermined pattern. In particular, when the high-compression portions 51 are arranged in a dotted-line pattern or in a grid pattern of continuous straight lines, the movement of the highly absorbent polymer particles 56p in the non-high-compression portions 52 is suppressed within the area surrounded by the high-compression portions 51, thus suppressing the uneven distribution of the highly absorbent polymer particles 56p with fewer high-compression portions 51. For example, it could also be as follows... Figure 21 The pattern shown is such that multiple high-compression sections 51 with different areas are arranged, and the area of ​​the largest high-compression section 51 is more than three times the area of ​​the smallest high-compression section 51. Figure 21 The pattern shown has multiple linear high-compression sections 51 of varying lengths but the same width, with the longest high-compression section 51 being more than three times the length of the shortest high-compression section 51. Furthermore, in Figure 21 In the example pattern shown, a high-compression portion 51 extending in the front-to-back direction LD, a high-compression portion 51 extending obliquely, and a high-compression portion 51 formed by a portion extending in the front-to-back direction LD and a portion extending obliquely from its front and rear ends are arranged in combination. Furthermore, in Figures 17-21 The dimensions of each part are recorded, but these dimensions are only examples and can of course be changed appropriately.

[0217] A preferred pattern for the high-compression section 51 is Figure 11 and Figure 16In this example, in the arrangement region of the high compression portions 51, a virtual lattice is determined which is formed by repeatedly arranging a first virtual straight line 81 in a first direction at a first interval 81d in a second direction inclined 80 to 90° clockwise with respect to the first virtual straight line 81, and a second virtual straight line 82 in the second direction at a second interval 82d in the first direction, and, when a smallest virtual quadrangle 83 having a vertex at the intersection of the first virtual straight line 81 and the second virtual straight line 82 is determined, the high compression portions 51 include: first high compression portions 51a arranged at the intersection positions of the first virtual straight line 81 and the second virtual straight line 82; second high compression portions 51b arranged between the adjacent first high compression portions 51a of the first virtual straight line 81 and between the adjacent first high compression portions 51a of the second virtual straight line 82, respectively; and third high compression portions 51c arranged at the intersection positions of the diagonals of the virtual quadrangle. Further, the first high compression portions 51a are circular with the center at the intersection of the first virtual straight line 81 and the second virtual straight line 82, the second high compression portions 51b are angular circular rectangles (or can be elliptical) having a center of gravity at the midpoint of each side of the virtual quadrangle and having a long axis in the direction of each side, and the third high compression portions 51c are square circular rectangles (can be elliptical or circular with the center at the intersection of the diagonals of the virtual quadrangle) having a center of gravity at the intersection of the diagonals of the virtual quadrangle and having a long axis in the front-rear direction LD. In this pattern, the diffusivity of the second high compression portions 51b in the long axis direction (the first direction and the second direction) can be improved, and, since both a portion in which the high compression portions 51 are not linearly continuous in the first direction and a portion in which the high compression portions 51 are not linearly continuous in the second direction are present, the absorber 56 as a whole is easily deformed along the body surface even if each high compression portion 51 is hardened.

[0218] When the high compression portions 51 are arranged in the virtual lattice of the example shown in FIG. 8, the size of each high compression portion 51 can be appropriately determined, but the diameter of the first high compression portion 51a is 1 to 4 mm, the length of the long axis of the second high compression portion 51b is 3 to 6 mm, and the length of the short axis is equal to the diameter of the first high compression portion 51a, and the third high compression portion 51c is the same size and the same shape as the second high compression portion 51b except that the orientation of the long axis is in the front-rear direction LD, and if the shortest distance d4 between the adjacent first high compression portions 51a and the second high compression portions 51b is 1 to 2 mm, not only the backflow resistance and the liquid diffusivity are improved, but also the deformability of the absorber 56 is improved, and thus this is preferable. 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 preferable 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. Figure 11 Figure 16 When the high compression portions 51 are arranged in the virtual lattice of the example shown in FIG. 8, the size of each high compression portion 51 can be appropriately determined, but the diameter of the first high compression portion 51a is 1 to 4 mm, the length of the long axis of the second high compression portion 51b is 3 to 6 mm, and the length of the short axis is equal to the diameter of the first high compression portion 51a, and the third high compression portion 51c is the same size and the same shape as the second high compression portion 51b except that the orientation of the long axis is in the front-rear direction LD, and if the shortest distance d4 between the adjacent first high compression portions 51a and the second high compression portions 51b is 1 to 2 mm, not only the backflow resistance and the liquid diffusivity are improved, but also the deformability of the absorber 56 is improved, and thus this is preferable. 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 preferable 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.​

[0219] In addition, if the above-mentioned imaginary lattice is formed in an inclined lattice shape in which the first imaginary straight line 81 is inclined 40 to 50° clockwise with respect to the front-rear direction LD in plan view, and the second imaginary straight line 82 is inclined 40 to 50° counterclockwise with respect to the front-rear direction LD in plan view, the deformability of the absorbent body 56 when worn is needless to say, and the spreadability of liquid is also excellent, and thus is preferred.

[0220] The arrangement of the high compression portion 51 is specifically shown in Table 2, for example.

[0221] [Table 2]

[0222]

[0223] 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-absorbency polymer particles are mixed and aggregated; a second step of forming a package 50P in which the entire absorbent body 56 is wrapped with a wrapping sheet 58; and a third step of forming the high compression portion 51 by pressing a portion of the package 50P that is sandwiched between a plurality of protrusion portions 91 of an anvil roll 90 and a flat roll 92, as shown in FIG. 8, the anvil roll 90 having the plurality of protrusion portions 91 arranged at intervals in the same pattern as the high compression portion 51 on the outer peripheral surface, and the flat roll 92 having a cylindrical surface (without the protrusion portions 91) opposite thereto. The high compression portion 51 can be formed while either or both of the anvil roll 90 and the flat roll 92 are heated, or the high compression portion 51 can be formed without heating. In the third step, only the portion of the package 50P that is sandwiched between the plurality of protrusion portions 91 of the anvil roll 90 and the flat roll 92 can be pressed, or the entire package 50P can be pressed while the portion of the anvil roll 90 that is sandwiched between the plurality of protrusion portions 91 and the flat roll 92 is pressed to the deepest. Figure 22

[0224] The size, shape, and arrangement of the front end surface of the protrusion portion 91 can be the same as the size, shape, and arrangement of the high compression portion 51, for example. The gap between the anvil roll 90 and the flat roll 92 (the minimum interval of the pressing position) can be set to be smaller than the thickness of the high compression portion 51, and can be set to be 0.5 to 1.5 mm, for example. The pressure at the time of forming the high compression portion 51 by the anvil roll 90 and the flat roll 92 can be appropriately set, and can be set to be 0.2 to 0.4 MPa, for example.

[0225] (Wrapping sheet)

[0226] ​As the packaging sheet 58, liquid-permeable sheets such as crepe paper, nonwoven fabric, polyamide nonwoven fabric, and perforated sheets can be used. There are no particular limitations on the nonwoven fabric used for the packaging sheet 58; SMS nonwoven fabric or SS MMS nonwoven fabric, which has at least one meltblown layer sandwiched between a pair of spunbond layers on the front and back, is preferred. There are no particular limitations on the fiber material; for example, polypropylene fibers or polyethylene / polypropylene bicomponent fibers can be used. The unit area weight of the packaging sheet 58 can be appropriately determined, but ideally it should be 5~40 g / m². 2 Ideally, the concentration should be 10-30 g / m³. 2 .

[0227] There are no specific limitations on the crepe paper used in packaging sheets, but the ideal weight per unit area is 13~20 g / m². 2 Ideally, the concentration should be 14-18 g / m³. 2 In addition, according to JISP8117:2009 "Paper and paperboard - Test methods for air permeability and air resistance (middle zone) - Gurley method" for crepe paper, the ideal air permeability is 1 to 15 seconds.

[0228] The average fiber length of the pulp constituting the crepe paper for packaging sheet 58 can be less than twice the average fiber length of all pulp fibers constituting absorber 56, but if it is 1.5 to 3 times, it has the advantage of improving material strength, and is therefore preferred. It is more preferable when the average fiber length of the pulp constituting the crepe paper for packaging sheet 58 is 1.5 to 3 times the average fiber length of all pulp fibers constituting absorber 56.

[0229] On the other hand, the crepe paper used for the packaging sheet 58 typically has a tensile elongation at break of 20-35% in the longitudinal direction (LD) and a tensile elongation at break of 4-8% (especially 5-7%) in the width direction (WD) as specified in JISP 8113:2006. If the packaging sheet 58 is such crepe paper, the crepe paper may sometimes break at the edge of the high compression portion 51 or between adjacent high compression portions 51 when the high compression portion 51 is formed. However, this can be reduced by making the shape of the high compression portion 51 without inflection points or bends, having a diameter of the largest inscribed circle tangent to the shape of the high compression portion 51 of 2-5 mm, and having a perimeter of the shape of the high compression portion 51 of 1-2.5 times the perimeter of the largest inscribed circle tangent to the shape of the high compression portion 51.

[0230] If the MD direction of the wrapping sheet 58 is constituted in the front-rear direction LD, it is easier to manufacture, and thus is preferable. At this time, since the fiber orientation of the wrapping sheet 58 is in the front-rear direction LD, the dry tensile strength in the width direction WD is significantly weaker than the dry tensile strength in the front-rear direction LD, and thus, if the size in the front-rear direction LD of the high compression portion 51 is more than twice, particularly more than three times, the size in the width direction WD of the high compression portion 51 (i.e., the high compression portion 51 is a shape that is longer in the front-rear direction LD), the wrapping sheet 58 is easily broken at both sides in the width direction WD. Therefore, if the size in the front-rear direction LD of the high compression portion 51 is less than twice, particularly less than 1.5 times, the size in the width direction WD of the high compression portion 51, the wrapping sheet 58 is difficult to break, and thus is preferable.

[0231] The wrapping configuration of the wrapping sheet 58 can be appropriately determined, but from the viewpoints of ease of manufacture or prevention of leakage of the high-absorbency polymer particles from the front-rear end edges, and the like, as shown in the illustrated example, it is preferable to wrap the wrapping sheet 58 in a cylindrical shape so as to surround the front and back surfaces and both side surfaces of the absorbent body 56, and to make the front-rear edge portions thereof protrude from the front and back of the absorbent body 56, and to join the overlapping portions of the wrapped portions and the protruding portions by a joining method such as heat fusion adhesive, material fusion, or the like.

[0232] In particular, as shown in Figure 15 the wrapping sheet 58 has a surface portion 58s on the surface side of the absorbent body 56, a first backside portion 58a that is a portion continuous from the surface portion 58s and that reaches the back side of the absorbent body 56 by winding around one side edge of the absorbent body 56, and a second backside portion 58b that is a portion continuous from the surface portion 58s and that reaches the back side of the absorbent body 56 by winding around the other side edge of the absorbent body 56, the first backside portion 58a and the second backside portion 58b have a laminated portion 58W in which they overlap each other, and if all the high compression portions 51 are formed on the laminated portion 58W, the crepe paper on the surface of the high compression portion 51 becomes double, the strength is increased, and it is difficult to break when the high compression portion 51 is formed, and thus is preferable.

[0233] The shape maintenance of the high compression portion 51 with respect to the absorbent member 50 is governed by the maintenance of the high compression portion 51 itself, and the maintenance of the high compression portion 51 itself is governed by the joining strength of the wrapping sheet 58 and the absorbent body 56 or the shape maintenance of the absorbent body 56 itself. Also, in the case of joining the wrapping sheet 58 and the absorbent body 56 with the heat fusible adhesives HM1, HM2, as the surface area increases due to the formation of the high compression portion 51, more heat fusible adhesives HM1, HM2 than usual are required in order to sufficiently maintain the joining strength of the wrapping sheet 58 and the absorbent body 56 and the shape maintenance of the absorbent body 56 itself. Therefore, the surface of the absorbent body 56 and the inner surface of the wrapping sheet 58 are preferably joined by 5.0 to 20.0 g / m 2Especially 7.5~15.0 g / m 2 Hot melt adhesives HM1 and HM2 are used for bonding.

[0234] For example, such as Figure 9 As shown, when a depression caused by the high-compression portion 51 is formed on the surface of the absorber 56, by providing two layers of hot-melt adhesive HM1 and HM2 on the back side of the absorber 56 throughout the area having the high-compression portion 51, the amount of the aforementioned hot-melt adhesive HM can be achieved. Figure 13 As shown, after applying a first hot melt adhesive HM1 to the inner surface of the unfolded packaging sheet 58 on approximately the entire surface opposite to the absorber 56, the absorber 56 is arranged at the middle portion of the width direction WD of the first hot melt adhesive HM1 on the packaging sheet 58. The back side of the absorber 56 and the packaging sheet 58 are bonded by the first hot melt adhesive HM1. Then, after applying a second hot melt adhesive HM2 to approximately the entire surface of the absorber 56, as shown... Figure 14 As shown, the portions of the packaging sheet 58 extending to both sides of the absorber 56 are folded back onto the surface of the absorber 56. The surface of the absorber 56 and the folded portions of the packaging sheet 58 are bonded together using a first hot melt adhesive HM1 and a second hot melt adhesive HM2. Simultaneously, the overlapping portions of the packaging sheet 58 are bonded together using the first hot melt adhesive HM1. Then, as... Figure 9 As shown, this structure is manufactured by forming a grid-shaped high-compression section 51 through embossing.

[0235] In order to reduce costs, such as Figure 9 As shown, the absorbent 50 may not have any other sheets such as paper or nonwoven fabric between the packaging sheet 58 and the absorbent 56 (or may have an adhesive layer), or may have other sheets on at least one side of the surface or back of the absorbent 56.

[0236] <Manufacturing Method of Absorber>

[0237] Absorber 56 can be manufactured using known methods. Figure 25 This is a schematic diagram illustrating an example of an absorbent manufacturing apparatus 100. In this absorbent manufacturing apparatus, an upstream pulp supply section 111 is provided for supplying fibrous material mainly comprising pulp. The pulp supply section 111 may include a desplitter for supplying pulp sheets 110 therein.

[0238] In manufacturing an absorber 56 containing hardwood pulp fibers, pulp sheets 110 containing hardwood pulp fibers are fed to a defiberizer. In the defiberizer, the pulp sheets 110 are mechanically defibered into fibers to obtain fluff pulp. The pulp sheets 110 can be either in bundles or rolls, but rolls are preferred as they increase productivity.

[0239] Furthermore, there are no particular limitations on the apparatus used for the mechanical processing of defibering the pulp sheet 110. Known defibering machines used in the manufacture of absorbent articles such as disposable diapers can be used. As for the mechanical processing, defibering machines utilizing friction or shear force are preferred. Examples of defibering machines include, for example, hammer defibering machines, impact defibering machines, roller defibering machines, and jet airflow defibering machines.

[0240] The fluff pulp obtained from fiber debonding is supplied into pipe 112. A polymer particle inlet 113 for supplying superabsorbent polymer particles can be provided midway through pipe 112. Therefore, pulp fibers 56f (fluff pulp) and superabsorbent polymer particles 56p are mixed in pipe 112 and then supplied to fiber stacking roller 115. Multiple absorber molds 115C are arranged circumferentially on the outer circumferential surface of fiber stacking roller 115. When fiber stacking roller 115 rotates, absorber molds 115C can sequentially receive the mixture of pulp fibers 56f and superabsorbent polymer particles 56p. The bottom surface of absorber mold 115C is composed of a perforated plate or mesh plate, and by drawing gas through the openings, the mixture of pulp fibers and superabsorbent polymer particles can be collected on the bottom surface of absorber mold 115C. Furthermore, by discharging gas through the openings, absorbers 56 can be supplied to conveying units 116 such as belt conveyors. Inside the fiber stacking roller 115, there are negative pressure chambers and positive pressure chambers, which allow for the suction and discharge of gas.

[0241] A scraping roller (or brush) 114 can be positioned downstream within the conduit 112. The scraping roller 114 scrapes away excess absorbent material accumulated after fiber buildup, homogenizing the surface of the absorbent material gathered in the absorbent mold 115C. Furthermore, the absorbent 56 supplied to the conveying unit 116 can be compressed in the thickness direction by the compression unit 117. For example... Figure 25 As shown, the compression unit 117 can be a pair of rollers or a pair of pressing members approaching from both sides of the absorbent 56. The compression unit 117 improves the shape retention of the absorbent 56.

[0242] Further downstream, absorbent 56 becomes absorbent element 50 by being wrapped by packaging sheet 58. The process of wrapping absorbent 56 with packaging sheet 58 can also be carried out by known methods.

[0243] When two layers of absorber 56 are stacked, as follows: Figure 26 As shown, a manufacturing apparatus 120 can be used, comprising single-layer manufacturing units 101 and 102 for manufacturing the layers of the absorber 56, which are shown as upper layer 56a and lower layer 56b in the example. The single-layer manufacturing units 101 and 102 each have the same features as the manufacturing apparatus 100 for manufacturing single-layer absorbers. Figure 25) the same structure. The layers 56a, 56b of the absorbent bodies respectively manufactured in the single-layer manufacturing sections 101, 102 are overlapped in the thickness direction, and then the entire body is wrapped with the wrapping sheet 58, thereby becoming the absorbent member.

[0244] (Rise gathers)

[0245] The rise gathers 60 have a rise portion 68 that rises from the side portion of the inner bag 200, and the rise portion 68 contacts a range from the groin portion of the wearer via the leg opening to the buttocks, thereby preventing side leakage. The rise gathers 60 can also be omitted as necessary. The rise gathers 60 of the illustrated example are structured such that the root side portion 60B is inclined to rise toward the width direction central side, and the front end side portion 60A is inclined to rise toward the width direction outer side, compared to the intermediate portion, but are not limited thereto, and appropriate changes can be made, such as rising the entire body toward the width direction central side, and the like.

[0246] More specifically, the rise gathers 60 of the illustrated example are formed by folding a band-shaped gather sheet 62 having a length equal to the front-rear direction length of the inner bag 200 in the width direction WD at the front end portion to make a double layer, and fixing a plurality of elongated gather elastic members 63 in the length direction in an elongated state, in the width direction WD, between the folded portion and the sheet adjacent thereto. The base end portion (the end portion on the opposite side of the sheet folded portion in the width direction WD) of the rise gathers 60 on the opposite side of the front end portion is provided as a root portion 65 that is fixed to the side portion of the inner bag 200, and the portion other than the root portion 65 is a main body portion 66 (the portion on the folded portion side) that extends from the root portion 65. In addition, the main body portion 66 has a root side portion 60B that extends toward the width direction central side, and a front end side portion 60A that is folded at the front end of the root side portion 60B and extends toward the width direction outer side. Furthermore, the main body portion 66 has both the front-rear direction end portions in a laid-down state fixed to the side surface of the top sheet 30 as laid-down portions 67, and the front-rear direction intermediate portion therebetween is provided as a rise portion 68 that is not fixed, and the gather elastic members 63 in the front-rear direction LD are fixed in an elongated state at least at the front end portion of the rise portion 68.

[0247] In the rise gathers 60 configured as above, the rise portion 68 is raised in a manner that comes into contact with the skin by the contraction force of the gather elastic members 63 as indicated by the arrow in the drawing. Figure 3 In particular, when the root portion 65 is located on the back side of the inner bag 200, the rise portion 68 is raised in a manner that opens toward the width direction outer side at the crotch portion and the vicinity thereof, and thus the rise gathers 60 are raised in a manner that faces the leg opening, and the fit will improve. The root portion 65 can also be fixed to the front side of the inner bag 200, such as being fixed to the surfaces on both sides of the top sheet 30.

[0248] As the standing gathers 60 as illustrated in the example, in a bent structure in which the body portion 66 is constituted of a root side portion 60B extending to the width direction central side and a front end side portion 60A which is folded back at the front end of the root side portion 60B and extends to the width direction outer side, the front end side portion 60A and the root side portion 60B are joined in a laid down state by the laid down portion 67, and the root side portion 60B is joined to the topsheet 30 in a laid down state. In the joining of the opposite faces of the laid down portion 67, at least one of a hot melt adhesive using various coating methods, and a method using material fusion such as heat sealing or ultrasonic sealing can be used. In this case, the joining of the root side portion 60B and the topsheet 30, and the joining of the front end side portion 60A and the root side portion 60B can be performed by the same method, or can be performed using different methods. For example, it is preferable to perform the joining of the root side portion 60B and the topsheet 30 using a hot melt adhesive, and to perform the joining of the front end side portion 60A and the root side portion 60B by material fusion.

[0249] As the gather sheet 62, it is preferable to use a material on which water repellent treatment is performed by silicone or the like on a soft and uniform and excellent concealing nonwoven fabric such as a spunbond nonwoven fabric (SS, SSS, or the like) or an SMS nonwoven fabric (SMS, SSMMS, or the like), a meltblown nonwoven fabric, or the like, as needed. The fiber unit area weight of the nonwoven fabric at this time is preferably 10 to 30 g / m 2 In addition, although not illustrated, a waterproof film can also be interposed between the gather sheets 62 which are folded into two layers.

[0250] As the gather elastic member 63, a rubber thread or the like can be used. When a spandex elastic thread is used, the fineness thereof is preferably 470 to 1240 dtex, and more preferably 620 to 940 dtex. The elongation rate of the gather elastic member 63 in the installed state is preferably 150 to 350%, and more preferably 200 to 300%. The number of the gather elastic member 63 is preferably 2 to 6, and more preferably 3 to 5. The arrangement interval of the gather elastic member 63 is suitably 3 to 10 mm. If so configured, in the range in which the gather elastic member 63 is arranged, it is easy to make surface contact with the skin. The gather elastic member 63 can be arranged not only at the front end side, but also at the root side.

[0251] In the erected portion 68 of the erected pleat 60, the bonding of the inner and outer layers of the pleat piece 62 and the fixation of the pleat elastic member 63 sandwiched therebetween can be at least one of the following fixing methods: hot melt adhesive using various coating methods and fixing by material welding such as heat sealing or ultrasonic sealing. If the entire surface of the inner and outer layers of the pleat piece 62 is bonded together, the flexibility will be compromised. Therefore, the portion of the pleat elastic member 63 other than the bonding portion is preferably not bonded or weakly bonded. The diagram illustrates the following structure: hot melt adhesive is applied only to the outer peripheral surface of the pleated elastic member 63 using a coating mechanism such as a coating gun or a Sure Wrap adhesive nozzle, and sandwiched between the inner and outer layers of the pleated sheet 62. Thus, the pleated elastic member 63 is fixed to the inner and outer layers of the pleated sheet 62, and the pleated sheet 62 is fixed between the inner and outer layers, solely by the hot melt adhesive applied to the outer peripheral surface of the pleated elastic member 63.

[0252] Similarly, for fixing the collapsed portion 67, at least one of the following methods can be used: hot melt adhesive using various coating methods, and heat sealing or ultrasonic sealing, which utilize material welding.

[0253] (flank)

[0254] like Figures 1-4 As shown, side wings 70 extending laterally toward the absorber 56 are provided on both sides of the inner body 200, and preferably, a lateral stretching region SG that stretches in the front-rear direction is formed on the side wings 70. The side wing 70 in the example figure has: one or more elongated lateral elastic members 73 arranged at intervals along the front-rear direction LD; a first layer 71 facing the outer side of the lateral elastic members 73; and a second layer 72 facing the inner side of the lateral elastic members 73.

[0255] The sheet material constituting the first layer 71 and the second layer 72 is not particularly limited, and can be any suitable nonwoven fabric, such as the nonwoven fabric available in the aforementioned raised pleats 60 or the aforementioned outer casings 12F and 12B. In the illustrated example, as described later, the pleat piece 62 of the raised pleats 60 is extended to form the first layer 71 and the second layer 72. At this time, the front and rear ends of the side wings 70 are raised, aligning with the front and rear ends of the pleats 60 (i.e., in this case, the front and rear ends of the inner casing 200).

[0256] The side elastic member 73 is not particularly limited, and the same elongated elastic member as the pleated elastic member 63 described above can be used. The elongation of the side elastic member 73 in the installed state is preferably 150-350%, more preferably 200-270%. The number of side elastic members 73 is preferably 2-16, more preferably 6-10. An arrangement interval of 5-10 mm for the side elastic members 73 is suitable.

[0257] The side elastic member 73 is fixed to the first sheet layer 71 and the second sheet layer 72. For the fixation of the side elastic member 73 which is attached to and sandwiched between the first sheet layer 71 and the second sheet layer 72, a fixation method using material fusion such as hot melt adhesive HM, heat sealing, or ultrasonic sealing based on various coating methods can be used. If the area of the joint of the first sheet layer 71 and the second sheet layer 72 is large, the softness is impaired, and therefore, it is preferable that the portion other than the adhesive portion of the side elastic member 73 is not jointed or weakly jointed. The illustrated example is a structure in which the hot melt adhesive HM is coated only on the outer peripheral surface of the side elastic member 73 by a coating mechanism such as a coating gun or a Sure Wrap glue applicator, and the side elastic member 73 is sandwiched between the first sheet layer 71 and the second sheet layer 72, and the fixation of the side elastic member 73 to the first sheet layer 71 and the second sheet layer 72 and the fixation between the first sheet layer 71 and the second sheet layer 72 are performed only by the hot melt adhesive HM coated on the outer peripheral surface of the side elastic member 73.

[0258] In addition, in the illustrated example, the sheet material constituting the first sheet layer 71 and the sheet material forming the second sheet layer 72 are folded back at the side edge of the side wing 70, and the folded back portions are fixed to the back surface of the liquid-impermeable sheet 11 (bag closure). The fixation can be performed by material fusion in addition to the use of the hot melt adhesive HM as in the illustrated example.

[0259] The side wing 70 can also be omitted.

[0260] <Manufacturing Example of Paper Pulp Sheet for Absorbent Body>

[0261] No. 1 to 20 of the paper pulp sheets containing broadleaf tree pulp fibers were manufactured using the materials shown in Table 1 according to the following procedure.

[0262] (Cooking Step)

[0263] (1) Broadleaf Tree

[0264] The acacia and eucalyptus were mixed in the mass ratio described in Table 1, and white liquor having a prescribed degree of sulfidity was added, and cooking was performed using a rotary autoclave at a liquor ratio of 6.0 (L / kg) and a maximum temperature of 170°C to obtain broadleaf tree unbleached kraft pulp having a kappa number of about 16.

[0265] (2) Coniferous Tree

[0266] White liquor having a prescribed degree of sulfidity was added to the fir, and cooking was performed using a rotary autoclave at a liquor ratio of 6.0 (L / kg) and a maximum temperature of 170°C to obtain coniferous tree unbleached kraft pulp having a kappa number of about 30.

[0267] (Washing Step)

[0268] After diluting the unbleached pulp to a pulp concentration of about 2%, No. 2 filter paper (manufactured by ADVANTEC) was laid on a Buchner funnel, and the pulp concentration was dewatered to about 12%. Then, the unbleached pulp was sandwiched with a square filter paper (manufactured by ADVANTEC) and pressure was applied with a press, and dewatered to a pulp concentration of 33%. This washing procedure was performed twice.

[0269] (Bleaching procedure)

[0270] (1) Deciduous tree

[0271] The unbleached kraft pulp was ozone bleached with an ozone gas having a concentration of 8.1% at 45°C for about 2 minutes. In addition, ozone bleaching was performed using ozone gas from a laboratory ozone generator of PSA Ozonizer SGA-01A-PSA4 manufactured by Sumitomo Precision Industries. Further, the ozone-bleached pulp was chlorine dioxide bleached at a chlorine dioxide addition rate of 1.5%, a pulp concentration of 10 mass%, and 70°C to obtain a deciduous tree bleached kraft pulp. In addition, between each bleaching procedure, a dilution washing procedure was performed twice in which, after diluting the pulp to a pulp concentration of about 2%, No. 2 filter paper (manufactured by ADVANTEC) was laid on a Buchner funnel, and the pulp concentration was dewatered to about 12%.

[0272] (2) Coniferous tree

[0273] The unbleached kraft pulp was chlorine dioxide bleached at a chlorine dioxide addition rate of 1.5%, a pulp concentration of 10 mass%, and 70°C for 30 minutes. Next, alkaline hydrogen peroxide bleaching was performed at an alkali addition rate of 1%, a hydrogen peroxide addition rate of 0.3%, a pulp concentration of 10 mass%, and 70°C for 120 minutes. Then, alkali treatment was performed at a sodium hydroxide addition rate of 0.2%, a pulp concentration of 10 mass%, and 70°C for 120 minutes. Next, chlorine dioxide bleaching was performed at a chlorine dioxide addition rate of 0.3%, a pulp concentration of 10 mass%, and 70°C for 150 minutes to obtain a coniferous tree bleached kraft pulp. In addition, between each bleaching procedure, a dilution washing procedure was performed twice in which, after diluting the pulp to a pulp concentration of about 2%, No. 2 filter paper (manufactured by ADVANTEC) was laid on a Buchner funnel, and the pulp concentration was dewatered to about 12%.

[0274] (Papermaking procedure)

[0275] The deciduous tree bleached kraft pulp and the coniferous tree bleached kraft pulp were diluted to a concentration of about 2% without being subjected to a beating treatment, and adjusted to the blending ratios described in Table 2. Then, using the adjusted pulp slurry, a hand sheet (pulp sheet for fluff pulp) having a basis weight of 800 g / m2was produced by a semi-automatic sheet former (manufactured by Kumagai Riki Kogyo Co., Ltd.).

[0276] <Manufacture of Absorbent Articles>

[0277] Using each of the pulp sheets, an absorbent body was manufactured by Figure 25 using the apparatus shown in Fig. 1. The amount of high-absorbency polymer added to the fluff pulp was 9.3 g with respect to 7.7 g of fluff pulp. Using the obtained absorbent body, a disposable diaper (belt type, L size) was manufactured without providing the high compression portion 51 described above.

[0278] <Measurement of Fiber Length and Fiber Width of Pulp Fibers, etc.>

[0279] The fiber length and fiber width of each of the unbleached hardwood kraft pulps after the cooking step and the washing step were measured. The fiber length and fiber width were measured using a fiber length measuring machine "VALMET FS5" manufactured by Valmet Corporation in accordance with JIS-P8226:2011 (ISO 16065-2:2007) "Pulp - Determination of fiber length - Method based on optical automatic analysis". The fiber analyzer "VALMET FS5" is a device capable of measuring the length and width of pulp fibers by image analysis when diluted pulp fibers pass through a measurement unit inside the fiber analyzer. From the obtained measurement values, the proportion by mass of pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm and the proportion by mass of pulp fibers having a fiber width of 10 μm or more and less than 35 μm were calculated. In addition, the average fiber length and the standard deviation σ when measuring the above-mentioned pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm at intervals of 0.02 mm (at a classification width of 0.02 mm) and the average fiber width and the standard deviation σ when measuring the above-mentioned pulp fibers having a fiber width of 10 μm or more and less than 35 μm at intervals of 1 μm (at a classification width of 1 μm) were calculated. In addition, the above-mentioned average values (values of average fiber length and average fiber width) are arithmetic averages. In addition, the above-mentioned standard deviations are values calculated based on n = 10000 or more measured by the fiber analyzer. The calculation results are shown in Table 3.

[0280] [Table 3]

[0281]

[0282] <Evaluation>

[0283] The evaluation was performed as follows. The evaluation results are shown in Table 4.

[0284] (Density)

[0285] The density of the fluff pulp of each example was measured in accordance with "Test method for thickness, density and specific volume of paper and paperboard" described in JIS-P8118 (2014).

[0286] (Calculation of specific burst strength)

[0287] The specific burst strength of the pulp sheet for fluff pulp of each example was calculated by dividing the burst strength [kPa] measured according to JIS-P8131 (2009) by the basis weight [kPa-m 2 / g].

[0288] (Fibrillation evaluation)

[0289] Based on the specific burst strength described above, the fibrillation of the pulp sheet for fluff pulp of each example was evaluated. The evaluation criteria were the following five stages. When the evaluation was A, B, C, and D, the fibrillation of the pulp sheet for fluff pulp was good, and the fibrillation was excellent when the evaluation was A. In addition, D was slightly poor, but was a level that was not a problem in practice.

[0290] A: The specific burst strength was 1.2 kPa-m 2 / g or more and 1.5 kPa-m 2 / g or less.

[0291] B: The specific burst strength was 1.6 kPa-m 2 / g or 1.1 kPa-m 2 / g.

[0292] C: The specific burst strength was 1.7 kPa-m 2 / g or 1.0 kPa-m 2 / g.

[0293] D: The specific burst strength was 1.8 kPa-m 2 / g or 0.9 kPa-m 2 / g.

[0294] E: The specific burst strength was 1.9 kPa-m 2 / g or 0.8 kPa-m 2 / g.

[0295] (Determination of Klemm water absorption)

[0296] The Klemm water absorption of the pulp sheet for fluff pulp of each example was determined according to "Paper and paperboard - Determination of water absorption - Klemm method" described in JIS-P8141 (2004). More specifically, for each pulp sheet for fluff pulp having a basis weight of 200 g / m 2 , the height [mm] at 1 minute after the start of the measurement was determined, and based on the heights [mm] at 1 minute and 2 minutes after the start of the measurement, the water absorption speed [mm / minute] between 1 minute and 2 minutes after the start of the measurement was calculated.

[0297] (Water absorption amount evaluation)

[0298] Based on the height value 1 minute after the start of the above measurement, the water absorption amount (absorption performance) of the fluff pulp sheet was evaluated according to the following criteria.

[0299] A: The height of the Klemm water absorption degree 1 minute after the start of the measurement was 29 mm or more and less than 40 mm.

[0300] B: The height of the Klemm water absorption degree 1 minute after the start of the measurement was 27 mm or more and less than 29 mm.

[0301] C: The height of the Klemm water absorption degree 1 minute after the start of the measurement was 25 mm or more and less than 27 mm.

[0302] D: The height of the Klemm water absorption degree 1 minute after the start of the measurement was less than 25 mm.

[0303] (Absorption speed evaluation)

[0304] Based on the value of the water absorption speed between 1 minute and 2 minutes after the start of the above measurement, the water absorption speed of the fluff pulp sheet was evaluated according to the following criteria.

[0305] A: The water absorption speed of the Klemm water absorption degree between 1 minute and 2 minutes after the start of the measurement was 9 mm / minute or more.

[0306] B: The water absorption speed of the Klemm water absorption degree between 1 minute and 2 minutes after the start of the measurement was 7 mm / minute or more and less than 9 mm / minute.

[0307] C: The water absorption speed of the Klemm water absorption degree between 1 minute and 2 minutes after the start of the measurement was 5 mm / minute or more and less than 7 mm / minute.

[0308] D: The water absorption speed of the Klemm water absorption degree between 1 minute and 2 minutes after the start of the measurement was more than 3 mm / minute and less than 5 mm / minute.

[0309] E: The water absorption speed of the Klemm water absorption degree between 1 minute and 2 minutes after the start of the measurement was more than 3 mm / minute or less.

[0310] (Operability evaluation at the time of fluff pulp production)

[0311] The operability at the time of fluff pulp production was as follows: The fluff pulp sheet of each example of 200 g / m 2 was cut into 2 cm x 2 cm, pulverized with a commercially available mixer (Tescom Corporation, Mixer TM856), and evaluated by confirming the degree of paper powder generation at the time of pulverization. In addition, the amount of paper powder generated at the time of pulverization increased from E to A. The evaluation was performed in 5 stages. When the evaluation was A, B, C, and D, the workability was good.

[0312] A: A little paper pulp accumulated on the wall surface of the mixer when the paper pulp pieces were pulverized.

[0313] B: A little paper pulp accumulated on the wall surface of the mixer when the paper pulp pieces were pulverized.

[0314] C: A little paper pulp accumulated on the wall surface of the mixer when the paper pulp pieces were pulverized.

[0315] D: A little paper pulp accumulated on the wall surface of the mixer when the paper pulp pieces were pulverized, but it was within a range that could be tolerated.

[0316] E: A lot of paper pulp accumulated on the wall surface of the mixer when the paper pulp pieces were pulverized, and it was at a level that could not be tolerated in actual use.

[0317] (Evaluation of Skin Inflammation Inhibiting Effect of Absorbent Article)

[0318] The paper diaper manufactured in each of the above examples was used by 220 test subjects, each of whom used any one of the samples numbered No. 1 to 22 for 10 pieces. That is, 10 test subjects evaluated the disposable paper diaper of one example at a time. Then, the number of pieces of paper diaper in which inflammation occurred was evaluated in percentage. The evaluation was performed in the following five stages. When the evaluation was A, B, C, and D, it meant that the inhibitory effect on skin inflammation was better than that of No. 20, which had the same structure as the existing product.

[0319] A: The incidence of inflammation was better than that of No. 20.

[0320] B: The incidence of inflammation was somewhat better than that of No. 20.

[0321] C: The incidence of inflammation was somewhat better than that of No. 20.

[0322] D: The incidence of inflammation was somewhat better than that of No. 20, and it could be used in practice.

[0323] E: The incidence of inflammation was the same as that of No. 20, and it was at the same level as the existing product.

[0324] In addition, the inflammation inhibiting effect was related to the backflow inhibiting effect of the absorbent body and the absorption capacity of the absorbent body.

[0325] [Table 4]

[0326]

[0327] As shown in Tables 3 and 4, the proportion of pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm was 42.6% or more, and the proportion of pulp fibers having a fiber width of 10 μm or more and less than 35 μm was 90.6% or more in the entire pulp fibers. No. 1 to 19 were good in defibrating property, operability in the production of fluff pulp, and inflammation suppression effect of the absorbent article.

[0328] <Effect Confirmation Test 1>

[0329] Samples of panty-type disposable paper diapers having an absorbent member with various conditions shown in Table 5 were produced (having the same configuration as Figures 1-6 the sample of Example 1), and thickness measurement of the absorbent member, a pressure-induced rewet test, measurement of the diffusion area, absorbent body strength test, and polymer exfoliation test were performed. In addition, the weight per unit area of the wrapping sheet, the dry tensile strength of the wrapping sheet, and the tensile elongation at break of the wrapping sheet in Table 5 were measured values of the raw material before the formation of the high compression portion.

[0330] The dimensions of each part of Samples 1 and 3 were as follows.

[0331] Length d3 of the first high compression portion 51a: 3 mm

[0332] Length diameter dl of the second and third high compression portions: 4.82 mm

[0333] Short diameter d2 of the second and third high compression portions: 3 mm

[0334] First interval 81d: 12.63 mm

[0335] Second interval 82d: 12.63 mm

[0336] Intersection angle of the first and second imaginary straight lines 81 and 82: 90 degrees

[0337] In Samples 1 and 3, the high compression portion was formed on the entire surface of the absorbent member under a pressure of 0.4 MPa. In addition, Samples 2 and 4 were comparative examples having no high compression portion. In addition, the conditions other than those shown in Table 5 were common to each sample.

[0338] (Pressure-induced rewet test)

[0339] This test was performed using a blue test solution prepared by dissolving about 5 g of Brilliant Blue FCF (packaging: powder) of Toray Industries, Inc. in about 300 ml of artificial urine, according to the following procedure.

[0340] (1) After cutting the side seal 12A of the sample, opening the front piece F and the back piece B, and placing the sample on a horizontally disposed flat plate with the surface (the surface having the high compression portion recessed) facing upward, the four corners of the sample were fixed to the flat plate with tape so that the inner container 200 was fixed in a flat, unfolded state.

[0341] (2) An injection cylinder (composed of an acrylic cylindrical portion with an inner diameter of 23 mm, an outer shape of 25 mm, and a height of 100 mm, and a square flange portion with a length of 100 mm x a width of 100 mm x a thickness of 2 mm extending around the cylindrical portion) was placed at the center (the center in the width direction and the center in the front-back direction) of the sample surface absorber and held vertically.

[0342] (3) A measuring cylinder was used at the upper end opening of the injection cylinder, and the above-described blue test solution was injected at a rate of 7 cm 3 / second for 50 cm 3 of the sample surface, and the injection cylinder was removed from there.

[0343] (4) After the injection cylinder was removed, the sample was left for 30 minutes.

[0344] (5) After the above-described (4), the steps of the above-described (2) to (4) were performed again.

[0345] (6) After the above-described (5), the steps of the above-described (2) and (3) were performed again.

[0346] (7) After the third injection of the above-described (6) was completely absorbed for 20 minutes, a 5-kg weight was placed on the injection site of the artificial urine, and left for 10 minutes. The weight had a flat bottom surface with a length of 100 mm x a width of 100 mm, and the length and width directions of the weight were aligned with the front-back direction and the width direction of the sample, and the center of the weight was placed on the center of the absorber.

[0347] (8) The weight (g) of 30 sheets of qualitative filter paper No. 2 (100 mm x 100 mm square) of ADVANTEC Co. was measured to the third decimal place.

[0348] (9) After the above-described (7), 30 sheets of the above-described filter paper were sandwiched with the center and the orientation aligned between the weight and the sample surface, and after 20 seconds, all of the filter paper was removed, and the weight (g) was measured to the second decimal place. The amount of back bleeding was calculated by subtracting the pre-absorption weight measured in the above-described (5) from the post-absorption weight.

[0349] (Measurement of Diffusion Area)

[0350] After the above pressure infiltration test, the sample was kept fixed on a flat plate set horizontally, a scale was arranged beside it, a still image of the sample and the scale was taken from directly above, the image data taken was read by image analysis software "Fiji" (Fiji Is Just ImageJ), and the area of the blue part of the sample surface was measured according to the following steps.

[0351] (1) Start Fiji, select "File" and "Open" in order, and read the image to be measured.

[0352] (2) Select the icon of "Straight", and align 2 points on the scale of the scale within the image.

[0353] (3) Select "Analyze" and "Set Scale" in order, input the actual size (read from the scale of the scale) between the 2 points combined in the above (2) to "Known distance", and input the unit in "Unit of length".

[0354] (4) Select "Image", "Type", and "8-bit" in order, and convert the image to 8-bit.

[0355] (5) Select "Image", "Adjust", and "Threshold" in order, display the Threshold selection screen, set Threshold to 150-210 (Default Red), check "Dark background" and "Don't reset range".

[0356] (6) Select "Analyze", "Set Measurements" in order, check "Area", "Mean gray value", "Min & Max gray value", and "Limit to threshold", and then select "OK".

[0357] (7) Select "Polygon selections", and enclose the liquid diffusion range in the red display range in the above (5).

[0358] (8) Select "Analyze" and "Measure" in order, display "Results", and take the item of "Area" as the diffusion area (set "Unit of length" to cm, and the unit of the area to cm 2 ).

[0359] (Absorbent strength test)

[0360] (1) After cutting the side seal 12A of the sample, opening the front body sheet F and the back body sheet B, the sample was placed on a horizontally disposed flat plate with the surface (the surface having the high compression portion recessed) facing upward, and the four corners of the sample were fixed to the flat plate with adhesive tape so that the inner container 200 was fixed in a flat, unfolded state.

[0361] (2) An injection cylinder (composed of an acrylic cylindrical portion with an inner diameter of 23 mm, an outer shape of 25 mm, and a height of 100 mm, and a square flange portion with a length of 100 mm, a width of 100 mm, and a thickness of 2 mm extending around the cylindrical portion) was placed at the center of the absorbent (the center in the width direction and the center in the front-rear direction) and at a position 100 mm behind the center, and was held vertically.

[0362] (3) A measuring cylinder was used at the upper end opening of the injection cylinder, and the blue test solution described above was injected at a rate of 7 cm 3 / second for 90 cm 3 . From the start of the injection until the sample surface was free of the artificial urine (completely absorbed), a weight of 300 g was placed on the flange portion of each injection cylinder, and a load was applied equally to the flange portions.

[0363] (4) After placing the weight of the above (3) for 5 minutes, the two weights and the injection cylinder at the back were removed, a measuring cylinder was used at the upper end opening of the central injection cylinder, and the blue test solution described above was injected at a rate of 7 cm 3 / second for 90 cm 3 . From the start of the injection until the sample surface was free of the artificial urine (completely absorbed), a weight of 300 g was placed on the flange portion of the central injection cylinder, and a load was applied equally to the flange portions.

[0364] (5) After placing the weight of the above (4) for 5 minutes, the sample was removed from the flat plate and mounted on the rotating plate 303 of the impact tester 300 described below, and the impact was repeatedly performed at 5-second intervals. In addition, in the initial state in which the rotating plate 303 was oriented downward, the outer surface of the front outer container 12F of the sample was attached to the hook member 303F of the rotating plate 303 in such a manner that the front-rear direction of the sample 320 was along the up-down direction.

[0365] (6) In the impact of the above (5), the tester visually recognized the shape of the absorbent of the sample 320 with respect to the impact surface 301S, and after confirming that a slit was generated on the absorbent, the impact was interrupted every time the sample was impacted, the width of the slit was measured with a scale, and the number of impacts at which the width of the slit reached 3 cm was recorded as the strength of the absorbent.

[0366] (Impact Tester)

[0367] Figure 27 andFigure 28 This refers to an impact testing machine 300. The impact testing machine 300 includes: a support body 310 consisting of a cuboid frame set on the ground; a light box 301 mounted in the middle of the vertical direction of the back part 311 of the support body 310; a first rotating shaft 302 separated above the light box 301 of the back part 311 and extending horizontally; a flat rotating plate 303 fixed at one end to the first rotating shaft 302 and freely supported in both directions between a vertically downward state and a state in which it rotates to the front side and faces horizontally; a second rotating shaft 304 arranged concentric with the center line extending horizontally along the rotation center line of the first rotating shaft 302; a sample holding arm 305 extending radially from the second rotating shaft 304 and supported by the second rotating shaft 304 in both directions; and a drive source (servo motor) 306 for rotating the sample holding arm 305 in both directions between a vertically downward state and a state in which it rotates to the front side and faces horizontally. The light box 301 has a transparent striking surface 301S on the front, through which the light from the internal illumination (white LED) 301L shines in the frontal direction. Additionally, in its initial state facing vertically downwards, the rotating plate 303 has hooks 303F, which are mechanically fastened to a substantially integral portion covering the frontal surface, allowing the outer surface of the sample 320 to be adhered to these hooks 303F. The sample holding arm 305 has a clamping part 307 and a drive source (not shown) for this operation at its front end. The clamping part 307 holds the lower end of the sample 320 hanging from the vertically downward-facing rotating plate 303. While maintaining this position, the lower end of the sample 320 rotates towards the frontal side until it reaches a substantially horizontal position, releasing the grip. Reference numeral 307C indicates a pair of clamping parts for holding the sample 320 from both sides of the lower end of the sample 320.

[0368] In this impact testing machine 300, after the sample 320 is attached to the rotating plate, in the initial state without the application of external force, such as Figure 27 As shown by the solid line, the sample 320 and the rotating plate 303 are positioned approximately vertically downwards, and the outer surface of the sample 320 is in contact with the striking surface 301S of the lamp box 301. Additionally, the sample holding arm 305 is positioned approximately vertically downwards, with the clamping part 307 at its front end open. At this point, if the test is to begin, it will proceed as follows... Figure 27 As indicated by the arrow and double-dotted line in the middle section, the clamping part 307 automatically closes, holding the lower end of the sample 320 and maintaining this state, while the sample holding arm 305... Figure 27 As indicated by the middle arrow and double-dotted line, rotate the sample until it is approximately horizontal on the front side, thus ensuring that the lower end of the sample 320 is also facing approximately the same direction. Next, as... Figure 27The sample 320 and the rotating plate 303 become a state of being directed substantially downward in vertical direction by stopping the test operation, and the sample 320 is stopped in a posture along the striking surface 301S of the light box 301. At this time, the tester who confronts the front surface of the sample 320 can visually recognize the shape of the absorber by the illuminating light from the light box 301 transmitted through the sample 320 (difference in transmission amount). In particular, the outer shape of the absorber which has absorbed the above-mentioned blue test solution is easily visually recognized.

[0369] (Polymer shedding test)

[0370] (1) After cutting the side seal 12A of the sample, opening the front body piece F and the back body piece B, and cutting the rear end portion of the inner container along the rear end of the absorber, the rear end of the absorber is exposed. In addition, the rear outer container 12B of the present sample has a turn-back portion 12r which covers the end portion on the waist opening WO side of the inner container 200, and therefore the turn-back portion 12r is peeled off and cut off using cold spraying.

[0371] (2) In the initial state where the rotating plate 303 of the above-mentioned striking tester 300 is directed downward in vertical direction, the outer surface of the front outer container 12F of the test sample is attached to the hook material 303F of the rotating plate 303 in a manner such that the front-rear direction of the sample 320 is along the up-down direction. In addition, a recovery tray which catches the high-absorbing polymer particles is provided at a position 10 cm below the striking surface 301S (omitted from the drawing). Thereafter, the striking is repeated 30 times at an interval of 5 seconds.

[0372] (3) After the striking of the above-mentioned (2), the weight of the fallen matter in the recovery tray is measured, and recorded as the amount of shed polymer.

[0373] The test results are shown in Table 5.

[0374] [Table 5]

[0375]

[0376] The sample 1 having the absorbent containing the broadleaf tree pulp fibers and the high compression portion formed on the absorbent member was higher in absorbent strength than the common sample 2, and had the same level of absorbent strength as the sample 3 having the absorbent composed only of the needle leaf tree pulp fibers. In addition, the diffusion area of the sample 1 was significantly higher than that of the sample 2, and was at the same level as that of the sample 3 having the absorbent composed only of the needle leaf tree pulp fibers. Further, the sample 1 was not only less in the re-uptake amount than the sample 2, but also significantly less than all the samples, and became a result worthy of special mention. In addition, the sample 1 was less in the amount of the polymer detached than the sample 2, and the result was at the same level as that of the sample 3 having the absorbent composed only of the needle leaf tree pulp fibers. In addition, it was found from the comparison between the samples 1 and 2, and the comparison between the samples 3 and 4 that the thickness of the absorbent member was reduced by forming the high compression portion, and that the inclusion of the broadleaf tree pulp fibers further reduced the thickness of the absorbent member as seen from the comparison between the sample 1 and the sample 3.

[0377] <Explanation of terms in the specification>

[0378] In the specification, the following terms have the following meanings unless otherwise specified.

[0379] • "Front-rear direction" means the direction indicated by the reference sign LD in the drawing (longitudinal direction), and "width direction" means the direction indicated by the reference sign WD in the drawing (lateral direction), and the front-rear direction and the width direction are orthogonal.

[0380] • "Front side" means the side close to the skin of the wearer when worn, and "back side" means the side away from the skin of the wearer when worn.

[0381] • "Front surface" means the surface close to the skin of the wearer when worn, and "back surface" means the surface away from the skin of the wearer when worn.

[0382] • "Stretch ratio" means the value when the natural length is taken as 100%. For example, a stretch ratio of 200% is synonymous with a stretch factor of 2 times.

[0383] • "Artificial urine" is a mixture of urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and ion exchange water: 97.09 wt%.

[0384] • "Gel strength" was measured as follows. 1.0 g of the superabsorbent polymer was added to 49.0 g of the artificial urine, and stirred with a stirrer. The resulting gel was left to stand in a constant temperature and humidity chamber at 40°C x 60% RH for 3 hours, and then returned to room temperature, and the gel strength was measured using a curd penetrometer (manufactured by I. techno Engineering: Curdmeter-MAX ME-500).

[0385] • "Weight per unit area" is measured as follows. The test sample or test piece is pre-dried, and then placed in a test chamber or device in a standard state (temperature 23 ± 1°C, relative humidity 50 ± 2% at the test site) to reach a constant weight state. Pre-drying refers to bringing the test sample or test piece to a constant weight in an environment at a temperature of 100°C. In addition, for fibers with a standard moisture regain of 0.0%, pre-drying can not be necessary. A sampling template (100 mm x 100 mm) is used to cut a 100 mm x 100 mm test sample from the test piece in a constant weight state. The weight of the test sample is measured, multiplied by 100, and the weight per 1 m2is calculated as the weight per unit area.

[0386] • The "thickness" of the thicker components such as the absorber 56 and the absorbing member 50 is measured using a thickness gauge (Peacock, dial gauge type thickness gauge, Model H (measurement range: 0 to 10 mm, measuring head: 10 mm diameter circular pressure flat, measuring force: about 1.7 N, pressure: about 21.7 kPa) manufactured by Sozoki Mfg. Co., Ltd.) after the test sample and the thickness gauge are made horizontal. The thickness of the absorbing member 50 (non-high compression portion 52) is obtained as follows. That is, in the non-high compression portion 52 of the absorbing member 50, the region where the maximum inscribed circle is selected from 10 regions inscribed in the outer shape of the non-high compression portion 52, and the thickness measured by aligning the center of the measuring head of the thickness gauge with the center of the inscribed circle of the region is taken as the thickness of the absorbing member 50 (non-high compression portion 52).

[0387] • 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).

[0388] • The "depth" of the high compression portion 51 is measured using One Shot 3D Measurement Macro Scope VR-3200 manufactured by Keyence Co., Ltd., or an equivalent machine, the observation application program "VR-H2V" and the analysis application program "VR-H2A", or equivalent software. In principle, the magnification at the time of measurement is 12 times, and the field of view area is 24 mm x 18 mm, but the magnification and the field of view area can be changed according to the size of the high compression portion 51. At the time of specific depth measurement, the above observation application program is started, the sample is placed on the stage of the microscope so that the high compression portion 51 of the measurement object is located in the field of view, and the "measurement" button is pressed. Next, the above analysis application program is executed, and analysis of the 3D information of the measurement is performed. Refer to Figure 23The analysis procedure is described as follows. That is, using the above analysis application, the depth (measured cross-sectional curve) profile of the line segment Ql of the center (barycenter in the case of a circle other than that) of one high compression portion 51 in the image portion (XY portion in the figure) expressed by a planar observation point is obtained. From the cross-sectional curve of this depth profile, in the "profile curve Q2" of the image portion (XZ portion in the figure) expressed by a cross-sectional viewpoint in which the component of surface roughness of short wavelength is removed by a low-pass filter from the cross-sectional curve of the depth profile, the position where the curve is substantially flat, or the position where the upward convexity is the strongest and the curve is the strongest, is set as two boundary points Pl, P2, and the minimum value of the height of the range sandwiched by the boundary points Pl, P2 is found. Further, the average of the height values of the boundary points Pl, P2 is taken as the maximum value of the height. Then, the maximum value of the height is subtracted from the minimum value of the height, and the depth of the high compression portion 51 can be found. In addition, the two boundary points Pl, P2 are selected visually. Further, in making this selection, the image of the planar viewpoint of the high compression portion 51 in the measurement can be referred to. The above measurement is performed on any 10 high compression portions 51 designed to be the same size and shape, and the results are taken as their average.

[0389] • The size such as the diameter or interval of the high compression portion 51 is measured using One Shot 3D Measuring Macro Scope VR-3200 manufactured by Keyence Corporation or the equivalent machine thereof, the observation application "VR-H2V" and the analysis application "VR-H2A", or their equivalent software. In principle, the magnification at the time of measurement is 12 times, and the field area is 24 mm x 18 mm, but the magnification and the field area can be changed according to the size of the high compression portion 51. Specifically, in measuring the size, the above observation application is activated, the sample is placed on the stage of the microscope, and the "Measurement" button is pressed so that the high compression portion 51 of the measurement object is located within the field. Then, the above analysis application is executed, and the analysis of the 3D information of the measurement is performed.

[0390] Reference will now be made to Figure 23The analysis procedure for the diameter of the high compression portion 51 will be described. That is, using the above analysis application program, in the image portion (XZ portion in the figure) represented by the planar observation point, the depth (measured cross-sectional curve) profile of the line segment Q1 passing through the high compression portion 51 of the object along an arbitrary diameter direction is obtained. In the "profile curve Q2" of the cross-sectional view represented image portion (XZ portion in the figure) obtained by removing the component of the surface roughness of a shorter wavelength than λc: 800 μm (where λc is the "filter defining the boundary between the roughness component and the waviness component" described in JIS-B0601 "3.1.1.2") by a low-pass filter, the intersection with the straight line Q3 parallel to the X axis at a distance of + 0.25 mm from the lowermost point 51L is set as P3, P4, and the distance X1 in the X axis direction of the intersection points P3, P4 is set as the diameter of the high compression portion 51. The above measurement is performed on any 10 high compression portions 51 designed to be the same size and shape, and the results are averaged.

[0391] Further, with reference to Figure 23 The analysis procedure for the interval of the adjacent high compression portions 51 will be described. That is, using the above analysis application program, in the image portion represented by the planar observation point, the depth (measured cross-sectional curve) profile of the line segment Q1 passing through the adjacent two high compression portions 51 of the object along the interval direction is obtained. In the "profile curve Q2" of the cross-sectional view represented image portion (XZ portion in the figure) obtained by removing the component of the surface roughness of a shorter wavelength than λc: 800 μm (where λc is the "filter defining the boundary between the roughness component and the waviness component" described in JIS-B0601 "3.1.1.2") by a low-pass filter, the intersection with the straight line Q3 parallel to the X axis at a distance of + 0.25 mm from the lowermost point 51L is set as P3, P4, P5, P6, and the distance X2 in the X axis direction of the intermediate adjacent two intersection points P4, P5 is set as the interval of the high compression portion 51. The above measurement is performed on any 5 sets of adjacent high compression portions 51 designed to be the same size and shape, and the results are averaged.

[0392] The "thickness" of the sheet such as nonwoven fabric is automatically measured using an automatic thickness measuring device (KES-G5 hand-held compression meter measuring program) under the conditions of load: 0.098 N / cm 2 and pressure area: 2 cm 2 .

[0393] • The "area" of the high compression portion 51 was measured using One Shot 3D Measuring Macro Scope VR-3200 manufactured by Keyence Corporation, or an equivalent machine thereof, the observation application "VR-H2V" and the analysis application "VR-H2A" thereof, or equivalent software thereof. In principle, the magnification at the time of measurement was set to 12 times, and the field of view area was set to 24 mm x 18 mm, but the magnification and the field of view area can be changed according to the size of the high compression portion 51. Specifically, in measuring the area, the above observation application was started, the sample was placed on the stage of the microscope so that the high compression portion 51 of the measurement object was located within the field of view, and the "measure" button was pressed. Next, the above analysis application was executed, and in order to perform analysis of the 3D information for measurement, the "volume / area" button was pressed to shift to the volume / area measurement screen. In the volume / area measurement screen, the "recess" button was pressed, and then the "set measurement area" button was pressed, and then the "height minimum" button was pressed from "auxiliary tool 2", and the area was specified so as to include one high compression portion 51 as the object, and the lowest point within the display area was selected. Then, "automatic extraction (height)" was selected from "element tool", and then the lowest point was specified as the reference point, and the height of the intersection was set to +0.25 mm, and the "OK" button was pressed. Returning to the volume / area measurement screen, the value displayed as the area of the portion from the lowest point within the specified area to a height of 0.25 mm was taken as the area of the high compression portion 51. The above measurement was performed on any 5 high compression portions 51 designed to be the same size and shape, and the results were taken as the average thereof.

[0394] • The "area rate" refers to the proportion of the area of the object portion per unit area, and the total area of the object portion (e.g., the high compression portion 51) in the entire object region (e.g., the back surface of the absorbent member 50) is divided by the area of the object region, and expressed as a percentage. When the area rate of the high compression portion 51 is sought, the rectangular region that circumscribes the entire high compression portion 51 is taken as the object region, and the total area of the high compression portion 51 is found from the area of the high compression portion 51 described below. That is, when 5 or more high compression portions 51 designed to be the same size and shape are provided, the area of the high compression portion 51 of the design is the average of all the areas measured by the above measurement method of the area of the high compression portion 51. On the other hand, in the case where the size and shape of the high compression portion 51 is irregular, or in the case where the high compression portion 51 designed to be the same size and shape is less than 5, the above measurement method of the area of the high compression portion 51 is used to measure all the high compression portions 51 one by one (without averaging).

[0395] • The "water absorption amount" was measured according to JIS K7223-1996 "Test method for water absorption of superabsorbent resin".

[0396] • "Absorption rate" is the "time until the end point" when JIS K7224-1996 "Test method for absorption rate of superabsorbent resin" is performed using 2 g of superabsorbent polymer and 50 g of physiological saline.

[0397] • "Unfolded state" means a state in which it is flatly unfolded without contraction (including contraction caused by elastic members and all contractions) or relaxation.

[0398] • The dimensions of each part refer to the dimensions in the unfolded state, not the natural length state, unless otherwise specified.

[0399] • In the case where there is no description of the environmental conditions in the test or measurement, the test or measurement should be performed in a test room or device under standard conditions (temperature 23 ± 1°C, relative humidity 50 ± 2% in the test site).

[0400] Industrial applicability

[0401] The present application can be used for all absorbent articles having an absorbent body, such as sanitary napkins, pet diapers, and the like, in addition to disposable paper diapers such as pant-type disposable paper diapers, belt-type disposable paper diapers, pad-type disposable paper diapers, and the like.

[0402] Reference signs

[0403] 11...liquid-impermeable sheet, 12A...side seal, 12B...back outer cover, 12E...waist extension portion, 12F, 12B...outer cover, 12F...front outer cover, 12S, 12H...sheet, 13...cover nonwoven fabric, 16, 19...lower waist elastic member, 17...waist elastic member, 18...unnecessary elastic member, 20...inner cover joint portion, 200...inner cover, 30...top sheet, 40...intermediate sheet, 50...absorbent member, 50P...package, 51...high compression portion, 51a...first high compression portion, 51b...second high compression portion, 51c...third high compression portion, 52...non-high compression portion, 56...absorbent body, 56f...pulp fiber, 56p...highly absorbent polymer particles, 56L...low area weight portion, 58...package sheet, 60...standing gathers, 60A...front end side portion, 60B...root side portion, 62...gather sheet, 63...gather elastic member, 67...laying portion, 68...standing portion, 70...flap, 71...first sheet layer, 72...second sheet layer, 73...side elastic member, 81...first imaginary straight line, 82...second imaginary straight line, 90...anvil roll, 91...protruding portion, 92...smoothing roll, A1...non-stretching region, A2...stretching region, B...back sheet, C...hip cover portion, F...front sheet, HM...hot melt adhesive, HM1...first hot melt adhesive, HM2...second hot melt adhesive, L...middle region, LD...front-rear direction, LO...leg opening, M...crotch portion, SG...side stretching region, T...waist region, TD...thickness direction, U...lower waist portion, W...waist portion, WD...width direction, WO...waist opening.

Claims

1. An absorbent article, characterized by, having a crotch portion, provided with an absorbent member having an absorbent body disposed in a front-and-rear direction range including the crotch portion, and a wrapping sheet wrapping the absorbent body, the absorbent body being a mixture, aggregation of pulp fibers containing broadleaf tree pulp fibers and high-absorbency polymer particles, the high-absorbency polymer particles having a proportion of particles having a particle diameter smaller than an average fiber length of the broadleaf tree pulp fibers before swelling of 60% by mass or more, the absorbent member being provided with a plurality of high-compression portions compressed in a thickness direction at intervals in a manner recessed from at least one of front and back surfaces of the absorbent member into the absorbent body, a portion other than the high-compression portions in an arrangement region of the plurality of high-compression portions being a non-high-compression portion thicker and lower in density than the high-compression portions, a shortest distance of each of the high-compression portions from the closest other high-compression portion being 1 to 4 mm, Each of the high compression portions has an area of 2 to 200 mm 2 .

2. The absorbent article of claim 1, wherein, an area ratio of the high-compression portions in the arrangement region of the plurality of high-compression portions being 10 to 35%, a diameter of a maximum inscribed circle inscribed in an outline of the non-high-compression portion being 30 mm or less.

3. The absorbent article of claim 2, wherein, the high-compression portion having an outline having no inflection point and bending point, and a diameter of a maximum inscribed circle inscribed in an outline of the high-compression portion being 1 to 10 mm, and a circumference of the high-compression portion outline being 1 to 15 times a circumference of the maximum inscribed circle inscribed in the outline of the high-compression portion.

4. The absorbent article of claim 2 or 3, wherein, in the arrangement region of the plurality of high-compression portions, a virtual grid is determined, wherein the virtual grid is formed by first virtual straight lines in a first direction being repeatedly arranged at a first interval in a second direction inclined 80 to 90° clockwise when viewed from the first virtual straight lines, and second virtual straight lines in the second direction being repeatedly arranged at a second interval in the first direction, and a smallest virtual quadrangle having a vertex at an intersection of the first virtual straight line and the second virtual straight line is determined, the high-compression portions include first high-compression portions arranged at positions of the intersection of the first virtual straight line and the second virtual straight line, second high-compression portions respectively arranged between adjacent first high-compression portions in the first virtual straight line and between adjacent first high-compression portions in the second virtual straight line, and third high-compression portions arranged at positions of intersections of diagonal lines of the virtual quadrangle, the first high-compression portions are circular in shape with the intersection of the first virtual straight line and the second virtual straight line as a center, the second high-compression portions are elliptical or rounded rectangular having a center of gravity at a midpoint of each side of the virtual quadrangle and having a long axis along each side, the third high-compression portions are elliptical or rounded rectangular having a center of gravity at an intersection of diagonal lines of the virtual quadrangle and having a long axis in the front-and-rear direction, or circular in shape with the intersection of the diagonal lines of the virtual quadrangle as a center.

5. The absorbent article of claim 4, wherein, the first high-compression portions have a diameter of 1 to 4 mm, the second high-compression portions have a long axis length of 3 to 6 mm, and a short axis length equal to the diameter of the first high-compression portions, the third high-compression portions are the same size and shape as the second high-compression portions except that the long axis is oriented in the front-and-rear direction. The minimum interval between the first high compression section and the second high compression section is 1 to 2 mm.

6. The absorbent article of claim 4, wherein, The imaginary lattice is an inclined lattice in which the first imaginary straight line is inclined 40 to 50° clockwise and the second imaginary straight line is inclined 40 to 50° counterclockwise in a top view with respect to the front-rear direction.

7. The absorbent article of claim 1 or 2, wherein, The unit area weight of the pulp fiber in the absorbent is 100-500 g / m 2 , The weight ratio of pulp fibers to high-absorbency polymer particles in the absorbent body is 40:60 to 65:35, The non-high compression section has a thickness of 3 to 13 mm, The high compression section has a thickness of 60 to 90% of the thickness of the non-high compression section.

8. The absorbent article of claim 1 or 2, wherein, The proportion of particles having a particle size of 500 μm or less before swelling in the high-absorbency polymer particles is 60% by mass or more, In all of the pulp fibers in the absorbent body, the proportion of pulp fibers having a fiber length of 0.5 mm or more and less than 1.1 mm is 40% or more by mass, and the proportion of pulp fibers having a fiber width of 10 μm or more and less than 35 μm is 90% or more by mass.

9. The absorbent article of claim 8, wherein, The pulp fibers of the absorbent body are composed of coniferous pulp fibers and broad-leaved tree pulp fibers, The mass ratio of the broad-leaved tree pulp fibers to the coniferous pulp fibers is 25 / 75 or more and 38 / 62 or less.

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