Absorbent core and absorbent article

Abstract

To provide an absorbent article having good fitness to a wearer and high absorption efficiency of body fluid.SOLUTION: An absorbent article 1 includes an absorbent core 7 having a first area 15, a third area 17 and a second area 16 that are different in rigidity from each other, in this order along a longitudinal direction X corresponding to a cross direction of a wearer. The first area 15 has a higher rigidity in the longitudinal direction X than the second area 16, and the second area 16 has a higher rigidity in the longitudinal direction X than the third area 17. The third area 17 includes a first deformation guide part 21 capable of deforming the absorbent core 7 so that a fold line is formed along a lateral direction Y on the absorbent core 7.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] Conventionally, there is known a technique for improving the fit of an absorbent core to a wearer by providing a deformation guide such as a groove or a slit in an absorbent core used in an absorbent article. For example, Patent Document 1 describes an absorbent article having a pair of deformation guides extending from the side edges inward in the width direction and inward in the length direction in the front and rear regions in the longitudinal direction of the absorbent core. The absorbent core further has a pair of longitudinal deformation guides on both sides along the longitudinal direction.

[0003] Patent Document 2 describes a pants-type absorbent article having an absorbent core with at least a first region and a second region having different basis weights, the first region including at least a crotch portion, and the second region including at least a back portion. The first region of the absorbent core has a fold guide portion group consisting of fold guide portions extending in the longitudinal direction of the absorbent core.

[0004] Patent Document 3 describes an absorbent article having an absorbent core with a pair of side slits located on both outer edges of the absorbent core in the width direction, the innermost edges of the pair of side slits being located behind the midline between the rear end edge of the absorbent core and the fold line for folding the absorbent article in half. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-117321 A [Patent Document 2] International Publication No. 2015 / 072218 Brochure [Patent Document 3] JP 2019-118576 A Summary of the Invention [Problem to be solved by the invention]

[0006] As described in Patent Documents 1 to 3, various absorbent articles having absorbent cores with deformation-inducing portions have been proposed, but there is a demand for further improvement in fit to the wearer and in the efficiency of absorbing bodily fluids. Therefore, an object of the present invention is to provide an absorbent article which fits well to a wearer and has excellent bodily fluid absorption efficiency. [Means for solving the problem]

[0007] The present invention relates to an absorbent core having a vertical direction corresponding to the front-to-back direction of a wearer and a horizontal direction perpendicular to the vertical direction, and having a first region, a third region and a second region, in this order along the vertical direction, which have different rigidities. In one embodiment, the first region preferably has a higher stiffness in the longitudinal direction than the second region. In one embodiment, the second region preferably has a higher stiffness in the longitudinal direction than the third region. In one embodiment, the third region preferably includes a first deformation inducing portion that is capable of deforming the absorbent core so that a line is formed along the lateral direction of the absorbent core. Effect of the Invention

[0008] According to the present invention, there is provided an absorbent article which fits well to a wearer and has excellent bodily fluid absorption efficiency. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a plan view of a pants-type disposable diaper, which is one embodiment of the absorbent article of the present invention, in an unfolded and fully stretched state as viewed from the skin-facing side. [Diagram 2] FIG. 2 is a cross-sectional view of the diaper shown in FIG. 1 taken along line II-II. [Diagram 3]3 is a plan view and a side view of the absorbent core of the diaper shown in FIG. 1, as viewed from the skin-facing side. [Figure 4] FIG. 4 is a perspective view showing a state in which the absorbent core shown in FIG. 3 has been deformed so that fold lines are formed along the lateral direction of the absorbent core. [Diagram 5] 5(a) and (b) are plan views of other embodiments of the absorbent core in the diaper shown in FIG. 1, as viewed from the skin-facing side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention will now be described based on preferred embodiments with reference to the drawings. Figures 1 and 2 show a pants-type disposable diaper (hereinafter simply referred to as a "diaper") 1, which is one embodiment of the absorbent article of the present invention.

[0011] The diaper 1 shown in Figures 1 and 2 has a ventral portion F located on the ventral side of a wearer when the diaper 1 is worn, a dorsal portion R located on the dorsal side, and a crotch portion M located between the ventral portion F and the dorsal portion R. When the diaper 1 is worn, the crotch portion M is disposed opposite excretory parts of the wearer such as the urethra and anus. When the diaper 1 is worn, the ventral portion F is a portion located closer to the ventral side of the wearer, i.e., closer to the front, than the crotch portion M. When the diaper 1 is worn, the dorsal portion R is a portion located closer to the dorsal side of the wearer, i.e., closer to the rear, than the crotch portion M. The diaper 1 has a longitudinal direction X corresponding to the front-to-back direction of a wearer and a transverse direction Y perpendicular thereto. In this specification, the "front-to-back direction of a wearer" refers to a direction extending from the wearer's abdominal side through the crotch region to the dorsal side. The diaper 1 extends in the longitudinal direction X from the abdominal region F through the crotch region M to the dorsal region R.

[0012] The diaper 1 comprises an absorbent body 5 having a liquid-retentive absorbent 4, and an exterior body 3 arranged on the non-skin-facing side of the absorbent body 5. In the exterior body 3, both side portions 1F, 1R along the longitudinal direction X in each of the ventral side portion F and the dorsal side portion R are joined to each other by a known joining means such as adhesive, heat sealing, ultrasonic sealing, etc. As a result, the diaper 1 has a pair of side seal portions (not shown) where the both side portions 1F, 1R are joined to each other, and further has a waist opening through which the wearer's torso passes, and a pair of leg openings (not shown) through which the wearer's lower legs pass.

[0013] In this specification, the "skin-facing side" refers to the side of a diaper or its constituent members (e.g., absorbent body) that faces the wearer's skin when the diaper is worn, and the "non-skin-facing side" refers to the side that faces away from the wearer's skin when the diaper is worn.

[0014] The absorbent main body 5 has a rectangular shape in a plan view, extends in the vertical direction X, and is disposed at the center of the exterior body 3 in the horizontal direction Y with its longitudinal direction coinciding with the vertical direction X of the diaper 1 in an unfolded and stretched state. The absorbent main body 5 is joined to the exterior body 3 by a known joining means such as an adhesive.

[0015] As shown in Figure 2, the absorbent body 5 comprises a liquid-permeable top sheet 12 which forms the skin-facing side, a liquid-impermeable or poorly liquid-permeable or water-repellent leak-proof sheet 13 which forms the non-skin-facing side, and a liquid-retaining absorbent body 4 arranged between the top sheet 12 and the leak-proof sheet 13, which are integrated together by a known joining means such as an adhesive. The absorbent body 4 has a function of absorbing and retaining bodily fluids such as urine. The absorbent body 4 is configured to include an absorbent core 7 containing a liquid-absorbent material, and a liquid-permeable core wrap sheet 9 that covers the surface of the absorbent core 7. As the liquid-absorbent material, for example, hydrophilic fibers such as pulp fibers, particles of water-absorbent polymers, and mixtures thereof can be used. In the absorbent body 4, the entire surface of the absorbent core 7, including the skin-facing surface and non-skin-facing surface, is covered with the core wrap sheet 9. Alternatively, only the skin-facing surface of the absorbent core 7 may be covered with the core wrap sheet 9. Furthermore, the absorbent body 4 does not need to be provided with the core wrap sheet 9. The absorbent core 7 will be described in detail later.

[0016] The exterior body 3 forms the outer shape of the diaper 1, i.e., the outer shapes of the abdominal portion F, the crotch portion M, and the back portion R. As shown in Fig. 1, in a plan view in an unfolded and stretched state, the abdominal portion F and the back portion R of the exterior body 3 have a rectangular shape whose length in the horizontal direction Y is longer than that in the vertical direction X, and in the crotch portion M, both side edges along the vertical direction X, i.e., a pair of leg edges LE, LE, form an hourglass shape narrowed inward in the horizontal direction Y. In a plan view in an unfolded and stretched state, both side edges of the abdominal portion F and the back portion R along the vertical direction X of the exterior body 3 protrude outward in the horizontal direction Y beyond the leg edges LE of the crotch portion M. In addition, the outer edge 6 in the vertical direction X of the abdominal portion F and the outer edge 6 in the vertical direction X of the back portion R of the exterior body 3 extend in the horizontal direction Y, forming a waist opening in the diaper 1 having a side seal portion formed therein. That is, these outer edges 6 in the longitudinal direction X form the peripheral edge WE of the waist opening.

[0017] The exterior body 3 is formed by laminating an inner layer sheet 61 and an outer layer sheet 62. The outer layer sheet 62 forms the outermost layer of the diaper 1. The outer layer sheet 62 is directly bonded to the inner layer sheet 61. The inner layer sheet 61 is directly bonded to the non-skin-facing surface of the leakproof sheet 13. The inner layer sheet 61 and the outer layer sheet 62 are bonded to each other by a known bonding means such as an adhesive, heat sealing, ultrasonic sealing, or the like.

[0018] A plurality of waist elastic members 63A are arranged in the waist opening region 1W, which is the end region of the exterior body 3 in the longitudinal direction X, sandwiched between an inner sheet 61 and an outer sheet 62. The waist elastic members 63A are made of rubber thread or the like, and are fixed between the sheets 61, 62 in a state in which they are stretchable in the lateral direction Y. When the diaper 1 is worn, the waist elastic members 63A contract to form waist gathers in the waist opening region 1W. The waist region 1D is located inward of the waist opening region 1W of the diaper 1 in the longitudinal direction X. A plurality of waist elastic members 63B are arranged in the waist region 1D. The waist elastic members 63B are fixed between the sheets 61, 62 in a state in which they are stretchable in the lateral direction Y. When the diaper 1 is worn, the waist elastic members 63B contract to form waist gathers in the waist region 1D. In this specification, the "waist region" refers to the region between the waist opening region 1W and the crotch part M.

[0019] In the outer cover 3, one or more leg elastic members 64 are arranged at leg edges LE forming the periphery of each of a pair of leg openings and sandwiched between an inner sheet 61 and an outer sheet 62. The leg elastic members 64 are fixed between the sheets 61, 62 in a state in which they are stretchable in the lateral direction Y. When the diaper 1 is worn, the leg elastic members 64 contract to form leg gathers (not shown) in the crotch portion M.

[0020] As shown in Figs. 1 and 2, a pair of leakage-proof cuffs 50, 50 extending in the longitudinal direction X are provided on both side regions of the skin-facing surface of the diaper 1. As shown in Figs. The leak-preventing cuff 50 includes a rectangular leak-preventing cuff-forming sheet 52 and a cuff elastic member 54 that can be stretched in the longitudinal direction X. The leak-preventing cuff 50 is formed by folding one leak-preventing cuff-forming sheet 52 in half and joining the two opposing leak-preventing cuff-forming sheets 52 together. One or more cuff elastic members 54 are arranged in a stretched state between the two opposing leak-preventing cuff-forming sheets 52. This makes the leak-preventing cuff 50 a stretchable region that can be stretched along the longitudinal direction X. The inner end of the leak-preventing cuff 50 in the lateral direction Y is a free end, and the outer end of the lateral direction Y is rolled up into the non-skin-facing side of the absorbent body 4 and fixed between the absorbent body 4 and the leak-preventing sheet 13 with an adhesive or the like. The leak-proof cuffs 50 stand up at least at the crotch portion M as the cuff elastic members 54 arranged in a stretched state contract, thereby preventing the outflow of excreted liquids such as urine in the lateral direction Y outward.

[0021] As shown in Fig. 3, the absorbent core 7 has a vertically long, generally rectangular shape in plan view. The absorbent core 7 has a ventral portion F, a dorsal portion R, a crotch portion M, a longitudinal direction X, and a lateral direction Y corresponding to the diaper 1. The ventral portion F of the absorbent core 7 is a region where the absorbent core 7 overlaps with the ventral portion F of the diaper 1. The dorsal portion R of the absorbent core 7 is a region where the absorbent core 7 overlaps with the dorsal portion R of the diaper 1. The crotch portion M of the absorbent core 7 is a region where the absorbent core 7 overlaps with the crotch portion M of the diaper 1. The longitudinal direction X of the absorbent core 7 coincides with the longitudinal direction X of the diaper 1. The lateral direction Y of the absorbent core 7 coincides with the lateral direction Y of the diaper 1.

[0022] The absorbent core 7 has three regions, a first region 15, a third region 17, and a second region 16, which have different stiffnesses from each other. The first region 15, the third region 17, and the second region 16 are arranged in this order along the longitudinal direction X. The first region 15 is located on the ventral region F side relative to the third region 17, and the second region 16 is located on the dorsal region R side relative to the third region 17. The third region 17 is located in the crotch portion M of the diaper 1. The first region 15, the second region 16, and the third region 17 all exist continuously throughout the lateral direction Y.

[0023] The first region 15, the second region 16, and the third region 17 are all made of the same absorbent material and have approximately the same density. As described below, the first region 15, the second region 16, and the third region 17 have different thicknesses. Therefore, each region can be distinguished, for example, by the difference in thickness.

[0024] The first region 15, the second region 16, and the third region 17 have different stiffnesses in the longitudinal direction X. In detail, the first region 15 has a stiffness higher than that of the second region 16 in the longitudinal direction X, and the second region 16 has a stiffness higher than that of the third region 17 in the longitudinal direction X. The absorbent core 7 has regions with different stiffnesses, and the stiffness of the third region 17, which is the region located at the center of the three regions, in the longitudinal direction X is the lowest. As a result, the absorbent core 7 is easily deformed in the third region 17 so that a fold line 25 is formed along the transverse direction Y, as shown in FIG. 4. Therefore, when the diaper 1 is worn, the absorbent core 7 is easily deformed as shown in the figure, and the diaper 1 is improved in fit to the wearer. In addition, the space between the wearer's crotch and the crotch part M of the diaper 1 can be efficiently secured, so that the diaper 1 can improve the efficiency of absorbing bodily fluids. In addition, pressure on the wearer's urination area can be suppressed.

[0025] Various methods can be used to differentiate the rigidity of the first region 15, the second region 16, and the third region 17. For example, the rigidity of each region can be differentiated by (i) making the thickness of each region different, (ii) making the density of each region different, (iii) making the materials constituting each region different, or (iv) combining any two or more of these methods. In particular, with respect to the third region 17, it is advantageous to control the rigidity by providing a first deformation guide portion, which will be described later.

[0026] From the viewpoint of more reliably deforming the absorbent core 7, the rigidity of the first region 15 in the longitudinal direction X is preferably 5.0 gf cm 2 / cm or more 20.0gf·cm 2 / cm or less, preferably 7.5 gf cm 2 / cm or more 10.0gf·cm 2 / cm or less. The stiffness of the second region 16 in the longitudinal direction X is preferably 3.0 gf cm, provided that the stiffness is lower than the stiffness of the first region 15 in the longitudinal direction X. 2 / cm or more 5.0gf·cm 2 / cm, preferably less than 3.5 gf cm 2 / cm or more 4.5gf cm 2 / cm or less. The stiffness of the third region 17 in the longitudinal direction X is preferably 0 gf cm, provided that the stiffness is lower than the stiffness of the second region 16 in the longitudinal direction X. 2 / cm super 3.0gf cm 2 / cm, preferably less than 0 gf cm 2 / cm super 1.5gf cm 2 / cm or less. By setting the stiffness of the first region 15, the second region 16 and the third region 17 within such ranges, it is possible to improve the fit of the diaper 1 to the wearer and the efficiency of absorbing body fluids.

[0027] From the same viewpoint as above, the ratio R2 / R1 of the stiffness R2 in the longitudinal direction X of the second region 16 to the stiffness R1 in the longitudinal direction X of the first region 15 is preferably 0.15 or more and less than 1.0, more preferably 0.3 or more and 0.9 or less, and even more preferably 0.45 or more and 0.8 or less. In addition, the ratio R3 / R1 of the stiffness R3 in the longitudinal direction X of the third region 17 to the stiffness R1 in the longitudinal direction X of the first region 15 is preferably 0 or more and less than 0.6, more preferably 0 or more and 0.45 or less, and even more preferably 0 or more and 0.3 or less. The stiffness in the longitudinal direction X of the first region 15, the second region 16 and the third region 17 can be measured as follows.

[0028] <Method of measuring stiffness in the longitudinal direction X> First, the absorbent core 7 is removed from the diaper 1 by, for example, cutting off members other than the absorbent core 7 as necessary. Next, the absorbent core 7 is cut along the longitudinal direction X and the lateral direction Y to cut out samples having a substantially rectangular parallelepiped shape with sides of 50 mm in the longitudinal direction X and 100 mm in the lateral direction Y from the regions to be measured (each of the first region 15, the second region 16, and the third region 17). A three-point bending test is performed on the obtained samples using a KES-FB2-L (large-scale bending tester) manufactured by Kato Tech Co., Ltd. to measure the rigidity in the longitudinal direction X.

[0029] In order to further improve the effect of improving the fit to the wearer, the third region 17 preferably includes a first deformation guide portion 21 capable of deforming the absorbent core 7 so that a fold line 25 is formed in the absorbent core 7 along the horizontal direction Y. From the viewpoint of making it easier for the first deformation guide portion 21 to guide the deformation of the absorbent core 7, the first deformation guide portion 21 is preferably arranged at least from both side edges of the absorbent core 7 in the horizontal direction Y toward the inside of the horizontal direction Y. In detail, the absorbent core shown in FIG. 3 has a pair of cutout portions 24, 24 as the first deformation guide portion 21. The cutout portions 24 are portions in which the absorbent core 7 is cut in a wedge shape from both side edges in the horizontal direction Y toward the inside of the horizontal direction Y in the third region. Since the third region 17 has the cutout portions 24, 24, the absorbent core 7 is easily bent along the fold line 25 that is a straight line connecting the vertices of the wedge shape in the pair of cutout portions 24, 24. The cutout portion 24 may be a region that does not contain any material such as fibers that constitute the absorbent core 7, or may be a region that contains a small amount of fibers.

[0030] The first deformation inducing portion 21 may have any shape as long as it can induce deformation such that a fold line 25 is formed in the absorbent core 7 along the horizontal direction Y, and is not limited to the shape of a wedge-shaped cutout portion 24. For example, as shown in Fig. 5(a), the absorbent core 7 may have a compressed portion 26 formed as the first deformation inducing portion 21 instead of the cutout portion 24. Alternatively, as shown in Fig. 5(b), the absorbent core 7 may have a compressed groove 27 formed along the horizontal direction Y as the first deformation inducing portion 21 instead of the cutout portion 24.

[0031] In the embodiment shown in Fig. 5(a), a pair of compressed portions 26 are formed on the absorbent core 7 from both side edges in the lateral direction Y toward the inside in the lateral direction Y. The compressed portions 26 are regions formed by compressing the absorbent core 7 in its thickness direction and compressing the constituent material of the absorbent core 7. Between the pair of compressed portions 26, 26, the constituent material of the absorbent core 7 is not compressed. In the embodiment shown in Fig. 5(b), the compressed grooves 27 formed in the absorbent core 7 are formed continuously and linearly over the entire area of ​​the absorbent core 7 in the lateral direction Y. Alternatively, the compressed grooves 27 may be formed in discontinuous linear shapes such as dotted lines. The compressed grooves 27 are regions formed by compressing the absorbent core 7 in its thickness direction and compacting the constituent material of the absorbent core 7.

[0032] The compressed portions 26 shown in Figure 5(a) and the compressed grooves 27 shown in Figure 5(b) have a higher density and a smaller thickness than other portions of the absorbent core 7. This makes the compressed portions 26 and the compressed grooves 27 the starting points for folding of the absorbent core 7, which makes it easier for fold lines to be formed in the absorbent core 7 along the lateral direction Y. From the viewpoint of making it easier to form these fold lines, the thickness T1 of the compressed portions 26 and the compressed grooves 27 is preferably more than 0 and not more than 0.8 relative to the thickness T0 of the absorbent core 7 where these portions are not formed, more preferably more than 0 and not more than 0.5, even more preferably more than 0.1 and not more than 0.3. The thickness of the absorbent core 7 was measured using a thickness gauge PEACOCK DIAL UPRIGHT GAUGES R5-C (manufactured by OZAKI MFG.CO.LTD.) at 5 cN / cm2 At this time, the load between the tip of the thickness gauge and the sample is 5cN / cm. 2 The measurement is performed by placing a plate (an acrylic plate with a thickness of about 5 mm) that is circular or square in plan view and has a size adjusted so that the measurement is performed.

[0033] 2, which is a cross-sectional view of the diaper 1 including the cutout portion 24 that is the first deformation inducing portion 21, the first deformation inducing portion 21 preferably has a portion that overlaps in the thickness direction with the leakproof cuff 50 that is the stretchable portion. Setting the positional relationship between the first deformation inducing portion 21 and the leakproof cuff 50 in this manner has the advantage that the absorbent core 7 becomes more easily deformed with the first deformation inducing portion 21 as the starting point for bending due to contraction of the leakproof cuff 50.

[0034] In order to allow the first deformation inducing portion 21 to more easily induce the deformation of the absorbent core 7, the length of the first deformation inducing portion 21 in the horizontal direction Y is preferably 10 mm or more, more preferably 20 mm or more, and even more preferably 30 mm or more, regardless of the form. The length of the first deformation inducing portion 21 in the vertical direction X is preferably 10 mm or more and 50 mm or less, and more preferably 15 mm or more and 30 mm or less.

[0035] From the viewpoint of making it easier for the first deformation inducing portion 21 to induce the deformation of the absorbent core 7, it is also preferable that the first deformation inducing portion 21 has a lower basis weight than the portions other than the first deformation inducing portion 21 in the third region 17. From this viewpoint, the basis weight of the first deformation inducing portion 21 is preferably 0 g / m 2 Super 50g / m 2 Less than or equal to 0 g / m 2 Super 25g / m 2 The following is the result.

[0036] From the viewpoint of making it easier for the first deformation inducing part 21 to induce the deformation of the absorbent core 7, it is preferable that the first deformation inducing part 21 does not contain an adhesive. The adhesive is, for example, an agent used to bond the materials constituting the absorbent core 7 together.

[0037] In order to facilitate deformation of the absorbent core 7 by the deformation guides in the third region 17, it is preferable to make the thickness of the absorbent core 7 greatest in the first region 15 and smallest in the second region 16, as shown in Fig. 3. In the third region 17, it is preferable to continuously decrease the thickness from the first region 15 to the second region 16. However, the form of the decrease in thickness in the third region 17 is not limited to this, and for example, the thickness of the third region 17 may decrease in a step-like manner from the first region 15 to the second region 16 in the longitudinal direction X. By having the thickness of the absorbent core 7 satisfy the above-mentioned relationship, the thickness of the absorbent core 7 increases near the wearer's urination point, thereby improving the liquid absorption efficiency.

[0038] With respect to the thickness of the absorbent core 7, the length of the absorbent core 7 in the longitudinal direction X in the first region 15 is preferably 50 mm or more and 500 mm or less, more preferably 175 mm or more and 400 mm or less, and even more preferably 250 mm or more and 350 mm or less. The length of the second region is preferably 25 mm or more and 200 mm or less, more preferably 50 mm or more and 175 mm or less, and further preferably 75 mm or more and 150 mm or less. The length of the third region is preferably 10 mm or more and 100 mm or less, and more preferably 25 mm or more and 75 mm or less.

[0039] The absorbent core 7 may have a fold line along the transverse direction Y in addition to the first deformation guide portion 21. The fold line along the transverse direction Y is a line along which the diaper 1 is folded in half in the longitudinal direction X (hereinafter also referred to as the diaper fold line), and serves to make it easier to package the diaper 1 for sale. Therefore, this fold line has a completely different purpose and effect from the fold line generated by the first deformation guide portion 21.

[0040] 1 and 3, the first deformation guide portion 21 of the absorbent core 7 is disposed on the rear portion R side of the center line CL that bisects the diaper 1 in the longitudinal direction X. This allows the absorbent core 7 to form a more three-dimensional structure by interacting with the diaper fold line when the diaper 1 is worn. Alternatively, the first deformation inducing portion 21 may be disposed on the abdominal side F side of the center line CL that divides the diaper 1 into two equal parts in the longitudinal direction X. Disposing the first deformation inducing portion 21 on the abdominal side F side of the center line CL interacts with the diaper fold line to form a more three-dimensional structure of the absorbent article when the diaper 1 is worn, as in the case of disposing the first deformation inducing portion 21 on the back side R side. This allows an efficient formation of a crotch space when the diaper is worn, and the diaper does not come into contact with the urination area, thereby maintaining comfort of the skin and ensuring a space necessary for absorbing bodily fluids. In order to obtain such an effect, the first deformation inducing portion 21 may be disposed on the back side R side of the center line CL that divides the diaper 1 into two equal parts in the longitudinal direction X, and another first deformation inducing portion 21 may be disposed on the abdominal side F side of the center line CL.

[0041] As shown in Figures 3 to 5, the absorbent core 7 preferably has a second deformation guide portion 22 that can deform the first region 15 so that a fold line is formed in the absorbent core 7 along the longitudinal direction X. The absorbent core 7 may have one or more second deformation guide portions 22. Figures 3 to 5 show a state in which three deformation guide portions 22 are formed in the first region 15.

[0042] The second deformation inducing portions 22 are portions that act as starting points or flexible axes for deformation of the absorbent core 7 when an external force is applied to the diaper 1 while the diaper 1 is being worn. For this purpose, the second deformation inducing portions 22 are preferably made of, for example, slits, grooves, or non-stacking portions extending in the longitudinal direction X. The slits are portions cut in the thickness direction of the absorbent core 7 and have no width. The grooves are elongated recesses of a given width and have a bottom. The non-stacking portions are grooves with their bottoms removed, and are portions in which no stacks such as pulp fibers constituting the absorbent core 7 are present. Whatever the form of the second deformation inducing portions 22, it is preferable that their widths, i.e., lengths in the transverse direction Y, are the same at any position in the longitudinal direction X.

[0043] When the absorbent core 7 has a plurality of second deformation inducing parts 22, the widths of the second deformation inducing parts 22 may all be the same or different. In particular, it is preferable that the widths of the second deformation inducing parts 22 are the same, since this makes it easier for the wearer's body fluids to diffuse uniformly and quickly within the absorbent core 7, thereby increasing the efficiency of absorption of the body fluids. To make this advantage more pronounced, the width of the second deformation inducing parts 22 is preferably 1 mm or more and 20 mm or less, and more preferably 3 mm or more and 15 mm or less.

[0044] When the absorbent core 7 has a plurality of second deformation inducing parts 22, the lengths of the second deformation inducing parts 22 in the longitudinal direction X may be the same or different. In particular, it is preferable that the lengths of the second deformation inducing parts 22 in the longitudinal direction X are the same, since this makes it easier for the wearer's body fluids to diffuse uniformly and quickly within the absorbent core 7, thereby increasing the absorption efficiency of the body fluids. To make this advantage more prominent, the length of the second deformation inducing parts 22 in the longitudinal direction X is preferably 50 mm or more and 350 mm or less, and more preferably 100 mm or more and 300 mm or less.

[0045] When the second deformation inducing parts 22 all have the same length in the longitudinal direction X, the positions of their ends on the ventral side F side in the longitudinal direction X may be the same or different. Similarly, the positions of their ends on the dorsal side R side in the longitudinal direction X may be the same or different. In the embodiment shown in Figures 3 to 5, the positions of the ends on the ventral side F side of the second deformation inducing parts 22 in the longitudinal direction X are the same, and therefore the positions of the ends on the dorsal side R side in the longitudinal direction X are also the same.

[0046] The basis weight of the second deformation inducing portion 22 is preferably lower than the basis weight of the portions other than the second deformation inducing portion 22 in the first region 15. The basis weight of the second deformation inducing portion 22 is preferably 0 g / m 2 More than 50g / m 2 Less than or equal to 0 g / m 2 Super 25g / m 2 The following is the result.

[0047] The absorbent core 7 of each of the above embodiments can be manufactured by a method known in the art. For example, the absorbent core 7 can be manufactured by using a fiber stacking device known in the art. The fiber stacking device generally includes a fixed drum and a rotating drum arranged on the outer periphery of the fixed drum. The rotating drum has an accumulation recess for accumulating the liquid-absorbent material on its outer periphery. The accumulation recess is structured so that air can be sucked from the outer periphery of the rotating drum toward the inside. Specifically, the accumulation recess has a bottom surface on which the liquid-absorbent material is accumulated, which is made of a breathable material, and the breathability of the breathable material varies depending on the location. As a result, the bottom surface has a high air suction part and a low air suction part. The high suction part and the low suction part have different degrees of air suction, so that the degree of accumulation of the liquid-absorbent material differs between the high suction part and the low suction part, and the basis weight of the obtained absorbent core 7 differs. As a result, the absorbent core has parts with different rigidities.

[0048] While the present invention has been described above based on its preferred embodiments, the present invention is not limited to the above-described embodiments and can be modified as appropriate without departing from the spirit of the present invention. For example, although the above embodiment is an application of the present invention to a pants-type disposable diaper, the application of the present invention is not limited to this, and the present invention may be applied to disposable diapers of a type other than pants-type disposable diapers, and absorbent articles other than disposable diapers, such as sanitary napkins, incontinence pads, and panty liners, etc. Among these, it is preferable that the present invention is applied to a disposable diaper. Furthermore, the absorbent core 7 is not limited to a single-layer structure, but may have a multi-layer structure. Specifically, for example, the absorbent core 7 may have a two-layer structure consisting of an upper core and a lower core. In the above embodiment, the absorbent core 7 has one each of the first region 15, the second region 16, and the third region 17, but may have a plurality of one or more of these regions 15 to 17. Specifically, for example, the absorbent core 7 may have the first region 15, the third region 17, the second region 16, and the first region 15 in this order along the longitudinal direction X. [Explanation of symbols]

[0049] 1. Pants-type disposable diapers 3 Exterior body 5. Absorbent body 7 Absorbent Core 15 First area 16 Second area 17 Third area 21 First deformation induction section 22 Second deformation induction section 50 Leak proof cuff

Claims

1. An absorbent core having a longitudinal direction corresponding to the front-to-back direction of a wearer and a transverse direction perpendicular to the longitudinal direction, the absorbent core having a first region, a third region, and a second region, which have different rigidities, arranged in this order along the longitudinal direction, The first region has a higher stiffness in the vertical direction than the second region, The second region has a higher stiffness in the vertical direction than the third region, The third region includes a first deformation guide portion that can deform the absorbent core so that a fold line is formed in the absorbent core along the lateral direction.

2. The rigidity of the first region in the longitudinal direction is 5.0 gf cm 2 / cm or more 20.0gf・cm 2 / cm or less, and the rigidity in the longitudinal direction of the second region is 3.0 gf cm 2 / cm or more5 .0 gf cm 2 10. The absorbent core of claim 1, wherein the thickness is 1 / cm or less.

3. The rigidity of the third region in the longitudinal direction is 0 gf cm 2 / cm over 3.0gf・cm 2 10. The absorbent core of claim 1, wherein the thickness is 1 / cm or less.

4. The absorbent core according to claim 1 , wherein the first deformation guide portions are arranged at least from both side edges of the absorbent core toward the inside in the lateral direction.

5. The absorbent core according to claim 4 , wherein the first deformation guide portion has a length in the horizontal direction of 10 mm or more and a length in the vertical direction of 10 mm or more and 50 mm or less.

6. the first deformation guide portion has a basis weight lower than that of a portion other than the first deformation guide portion in the third region; The basis weight of the first deformation guide portion is 0 g / m ２ Super 50g / m ２ 2. The absorbent core of claim 1, wherein:

7. The absorbent core of claim 1 , wherein the first deformation guide does not contain an adhesive.

8. The absorbent core according to claim 1 , wherein the first region has a second deformation guide portion that can deform the absorbent core so that a fold line is formed in the absorbent core along the longitudinal direction.

9. the basis weight of the second deformation guide portion is lower than the basis weight of the portion other than the second deformation guide portion in the first region; The basis weight of the second deformation guide portion is 0 g / m ２ 50g / m or more ２ 9. The absorbent core of claim 8, wherein:

10. An absorbent article comprising the absorbent core according to any one of claims 1 to 9.

11. The absorbent article according to claim 10 , wherein the absorbent core has a fold line along the lateral direction separate from the first deformation guide portion.

12. The absorbent article according to claim 10 , wherein the first deformation guide portion is disposed on the back side portion side of a center line that divides the absorbent article into two equal parts in the longitudinal direction.

13. The absorbent article according to claim 10 , wherein the first deformation guide portion is disposed closer to the ventral portion than a center line that divides the absorbent article into two equal parts in the longitudinal direction.

14. The absorbent article has elastic parts that extend along the longitudinal direction, The absorbent article according to claim 10 , wherein the first deformation guide has a portion that overlaps with the stretchable portion in the thickness direction.

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