JP2020028676A - Absorber - Google Patents

Abstract

To provide an absorber which includes a highly absorptive polymer of high absorption performance and yet achieving an excellent wet-time shape retention property to thereby enable an excellent body fluid repetitive absorption property.SOLUTION: The present invention provides an absorber 17, including: a laminated absorbent core 21 which is laminated with a first absorbent core layer 18, an intermediate layer 19, and a second absorbent core layer 20 in this order, with a highly absorptive polymer included therein; and a core-wrap sheet 26. A first core-wrap sheet portion 24 located on one side from a center plane Tc in the thickness direction has a water-absorbent nonwoven fabric containing water-absorbent fibers having a fiber length of 25 mm or more entangled with each other. The absorber 17 has joining portions 29 at which the intermediate layer 19 and the first core-wrap sheet portion 24 are joined. The wet-time elongation of the water-absorbent nonwoven fabric is larger than the dry-time elongation. The wet-time tensile strength is lower than the dry-time tensile strength. The intermediate layer 19 is a heat-sealed nonwoven fabric having a wet-time elongation and tensile strength in a range of 90% or more and 110% or less of the dry-time elongation and tensile strength.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an absorber.

  BACKGROUND ART Absorbent articles including an absorbent (also referred to as an SAP sheet) having a high ratio of a superabsorbent polymer (SAP; Super Absorbent Polymer) are known.

  For example, Patent Literature 1 discloses an absorber having a structure in which an absorbent core layer containing a highly absorbent polymer and an adhesive is sandwiched by a nonwoven fabric from above and below the absorbent core layer, An absorber is disclosed in which a layer is divided by a predetermined intermediate layer into a first absorbent core layer and a second absorbent core layer.

International Publication No. 2011/136087

In the absorbent having a high ratio of the superabsorbent polymer, when the superabsorbent polymer absorbs body fluid and swells, the volume of the region formed inside the core wrap sheet containing the superabsorbent polymer is too small. The swelling of the superabsorbent polymer is limited, and the absorption performance is low. However, in the absorber described in Patent Document 1, since the upper core wrap sheet and the lower core wrap sheet are not mutually bonded, even if the superabsorbent polymer swells, Swelling is not easily restricted by the lower core wrap sheet. Therefore, with this absorber, it was possible to suppress a decrease in the absorption performance of the superabsorbent polymer. However, in this absorber, since the upper and lower core wrap sheets and the intermediate layer are not bonded to each other, the upper and lower core wrap sheets and the intermediate layer are separated from each other by the swelling of the superabsorbent polymer. As a result, there is a possibility that the shape is weakened by deformation due to external force, and the shape retention in wet state, which is difficult to lose its shape in a state where the absorber absorbs body fluid, is deteriorated.
Further, when the upper and lower core wrap sheets and the intermediate layer are connected to each other in order to improve the shape retention when wet, the volume of the region formed inside the upper and lower core wrap sheets is limited. In addition, the swelling of the superabsorbent polymer is suppressed, and the absorption performance of the superabsorbent polymer may be reduced.
Furthermore, in the absorber described in Patent Document 1, when the core wrap sheet of the upper layer and the lower layer and the intermediate layer are mutually bonded, when the body fluid is repeatedly absorbed, the swollen high absorbent polymer of the first absorbent core layer and The intermediate layer may be pressed from both sides and collapsed by the superabsorbent polymer of the second absorbent core layer. In that case, the voids between the fibers of the intermediate layer are reduced and the liquid permeability is reduced, so that the body fluid may not easily reach the second absorbent core layer via the intermediate layer. That is, there is room for improvement in the body fluid repetitive absorption, which is the body fluid absorption performance when repeatedly absorbing body fluid.

  Accordingly, the present invention has been made in view of the above problems, and has an excellent shape retention property when wet, and has a high absorption performance of a highly absorbent polymer, and an object of the present invention is to provide an absorbent body having excellent body fluid repetitive absorption property. Aim.

  In view of the above problems, the inventors of the present invention have conducted intensive studies. As a result, a laminated absorbent core having an intermediate layer that is a heat-sealed nonwoven fabric, and a core wrap sheet, wherein at least one side of the core wrap sheet contains water-absorbent fibers having a predetermined fiber length entangled with each other. An absorbent body having a non-woven fabric and an intermediate layer, at least a part of a core wrap sheet being joined, wherein the water-absorbent non-woven fabric is more easily stretched when wet than when dry, and when the intermediate layer is wet and when dry. The present inventors have found that the above problems can be solved by an absorber having the same elongation characteristics, and have completed the present invention.

  Specifically, the present invention has a first surface and a second surface, and a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other, and from the first surface to the second surface, The first absorbent core layer, the intermediate layer, and the second absorbent core layer are an absorbent article for an absorbent article having a laminated absorbent core laminated in this order and a core wrap sheet, The absorbent core layer and the second absorbent core layer contain a superabsorbent polymer, and the core wrap sheet is a first core wrap sheet portion located on a first surface side of a thickness direction center surface of the absorber. And a second core wrap sheet portion located closer to the second surface than the center surface in the thickness direction of the absorber, wherein the first core wrap sheet portion has a fiber length of 25 mm or more entangled with each other. Having a water-absorbent nonwoven fabric made of water-absorbent fibers containing fibers, the absorbent body, The intermediate layer and the first core wrap sheet portion have a joint portion, wherein the water-absorbent nonwoven fabric has a greater elongation in a wet tensile test than in a dry tensile test; The tensile strength in the test is lower than the tensile strength in the dry tensile test, and the intermediate layer is a heat-fused nonwoven fabric in which a plurality of thermoplastic synthetic fibers are fused. Provided is an absorbent having a degree and a tensile strength of 90% to 110% of the elongation and the tensile strength in a dry tensile test, respectively.

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in the shape retention at the time of a wet, the absorption performance of a superabsorbent polymer is high, and the absorber which is excellent in body fluid repetition absorbency can be provided.

It is a plane development view of the tape stop type disposable diaper 1 provided with the absorber 17 which concerns on embodiment of this invention. FIG. 2 is a cross-sectional view of the absorbent body 17 before body fluid absorption on a W ₁ -W ₁ plane in FIG. 1. FIG. 2 is a cross-sectional view of the absorber 17 on the W ₁ -W ₁ plane in FIG. 1 after absorbing body fluid. FIG. 3 is an enlarged perspective view of a core wrap sheet 26 provided in an absorber 17 according to the embodiment of the present invention.

<Aspect of the present invention>
The present invention relates to the following embodiments.

[First aspect]
(Constitution)
A first aspect of the present invention has a first surface and a second surface, and a longitudinal direction, a width direction, and a thickness direction orthogonal to each other, and from the first surface to the second surface, The first absorbent core layer, the intermediate layer, and the second absorbent core layer are an absorbent article for an absorbent article having a laminated absorbent core laminated in this order and a core wrap sheet, The absorbent core layer and the second absorbent core layer contain a superabsorbent polymer, and the core wrap sheet is a first core wrap sheet portion located on a first surface side of a thickness direction center surface of the absorber. And a second core wrap sheet portion located closer to the second surface than the center surface in the thickness direction of the absorber, wherein the first core wrap sheet portion has a water absorption of fiber length 25 mm or more entangled with each other. Having a water-absorbent nonwoven fabric made of water-absorbent fibers containing fibers, the absorbent body, The intermediate layer and the first core wrap sheet portion have a joining portion joined together, and the elongation in the wet tensile test of the water-absorbent nonwoven fabric is larger than the elongation in the dry state, The tensile strength is lower than the tensile strength in the dry tensile test, the intermediate layer is a heat-fused nonwoven fabric in which a plurality of thermoplastic synthetic fibers are fused, and the elongation and the elongation in the wet tensile test of the heat-fused nonwoven fabric It is an absorber whose tensile strength is in the range of 90% or more and 110% or less of the elongation and the tensile strength in the dry tensile test, respectively.

(effect)
The intermediate layer provided in the absorbent body according to the first aspect of the present invention has a plurality of thermoplastic synthetic fibers fused together, and has an elongation and a tensile strength in a wet tensile test and an elongation and a tensile strength in a dry tensile test. The intermediate layer has a small change in its elongation characteristics even when it absorbs water. Here, in the first aspect of the present invention, the first core wrap sheet portion is joined to the intermediate layer. Therefore, even if the first core wrap sheet portion is stretched (deformed) due to the water absorption and swelling of the superabsorbent polymer, the intermediate layer that is not easily stretched (deformed) suppresses the deformation of the entire absorber. be able to. Thereby, the absorbent body is excellent in the shape retention at the time of holding the shape when wet.

  In addition, the intermediate layer, the thermoplastic fibers are fused together, and the characteristics with respect to the load during dry and wet are unlikely to change, so the intermediate layer is less likely to elongate when wet and receives a load, for example, Even when the superabsorbent polymer of the first absorbent core layer and the second absorbent core layer receives a load due to water absorption and expansion, the intermediate layer is not easily crushed. Therefore, the above-mentioned absorber, even under conditions in which the superabsorbent polymer swells, the intermediate layer is excellent in fluid permeability, which is permeable to bodily fluids, and it is difficult to inhibit the diffusibility of bodily fluids. Excellent in repeated absorption of body fluid that repeatedly absorbs.

  Furthermore, among the core wrap sheets provided in the absorbent body of the first aspect of the present invention, at least the first core wrap sheet portion is made of water-absorbing fibers containing water-absorbing fibers having a fiber length of 25 mm or more entangled with each other, It has a water-absorbent nonwoven fabric whose elongation in a wet tensile test is larger than that in a dry tensile test, and whose tensile strength in a wet tensile test is lower than that in a dry tensile test. The first core wrap sheet portion made of a water-absorbing nonwoven fabric has a property that it is easily stretched when wet by absorbing body fluid, but when the first surface is a skin side surface, the first core wrap sheet portion becomes wet when the absorber absorbs water. Absorbs the bodily fluid that has permeated from the first surface side and relatively easily expands. Also, when the first surface is the clothing side surface, when the absorbent absorbs water, the first core wrap sheet portion penetrates the absorbent and absorbs the bodily fluid held on the clothing side of the absorber, and is relatively Easily stretches. Therefore, the absorption performance of the superabsorbent polymer can be enhanced by elongating the first core wrap sheet portion.

[Second aspect]
(Constitution)
A second aspect of the present invention is the absorbent body according to the first aspect, wherein the water-absorbing fiber having a fiber length of 25 mm or more is a regenerated cellulose fiber.

(effect)
Regenerated cellulose fibers are superior in fiber uniformity (fiber length, fiber diameter, etc.) as compared to pulp fibers. Therefore, when the water-absorbent fiber having a fiber length of 25 mm or more is a regenerated cellulose fiber, the water-absorbent nonwoven fabric is more likely to be stretched by water absorption than in a case where the water-absorbent fiber is a pulp fiber. On the other hand, when the water-absorbent nonwoven fabric is to be stretched at an elongation of a certain ratio or more, a relatively large tensile strength acts, so that the absorbent body is excellent in the above-mentioned wet shape retention.

[Third embodiment]
(Constitution)
A third aspect of the present invention is the absorbent body according to the first or second aspect, wherein the water-absorbent nonwoven fabric is a spunlaced nonwoven fabric.

(effect)
According to the third aspect of the present invention, since the water-absorbent nonwoven fabric is a spunlaced nonwoven fabric in which entanglement between fibers is apt to occur, the water-absorbent nonwoven fabric is easily stretched, and the absorbency of the superabsorbent polymer is enhanced.

[Fourth aspect]
(Constitution)
A fourth aspect of the present invention is the absorber according to any one of the first to third aspects, wherein the heat-sealed nonwoven fabric is an air-through nonwoven fabric.

(effect)
Since the air-through nonwoven fabric is bulky and has excellent cushioning properties, even when the first absorbent core layer and the second absorbent core layer are swollen, the liquid permeability of the intermediate layer is hardly hindered, and the absorbent absorbs the body fluid repeatedly. Excellent in nature.

[Fifth aspect]
(Constitution)
The water-absorbent nonwoven fabric extends along the longitudinal direction, a plurality of high-density portions arranged side by side in the width direction, and extends along the longitudinal direction, among the plurality of high-density portions. And a plurality of low-density portions disposed between adjacent high-density portions.

(effect)
According to the fifth aspect of the present invention, the water-absorbent nonwoven fabric has high-density portions and low-density portions alternately arranged along the longitudinal direction. The plurality of high-density parts can easily diffuse the body fluid in the longitudinal direction, and the plurality of low-density parts can easily make the water-absorbent nonwoven fabric stretch in the width direction of the absorber. Here, when the first surface is the skin side surface, the first core wrap sheet portion absorbs the bodily fluid that has permeated from the first surface side and facilitates the diffusion of the bodily fluid in the longitudinal direction. Further, when the first surface is the clothing side surface, when the absorbent absorbs water, the first core wrap sheet portion penetrates the absorbent and absorbs the bodily fluid held on the clothing side of the absorbent, thereby absorbing the bodily fluid. Facilitates longitudinal diffusion. This makes it easier for the absorber to absorb body fluid in a wide range along the longitudinal direction, thereby increasing the absorption area ratio of the absorber, and as a result, the absorber is excellent in the above-described body fluid repetitive absorbability.

[Sixth aspect]
(Constitution)
According to a sixth aspect of the present invention, the absorber is divided into width-direction both ends arranged at both ends in the width direction and a width-direction middle portion sandwiched between the width-direction ends. An intermediate joining portion in which the intermediate layer and at least one of the first core wrap sheet portion and the second core wrap sheet portion are joined at the intermediate portion in the width direction. The absorbent body according to any one of the above aspects.

(effect)
According to the sixth aspect of the present invention, at least one of the first core wrap sheet portion and the second core wrap sheet portion is joined to the intermediate layer that is hardly stretched when dry and wet. Since the absorbent body has an intermediate joint portion, the absorber has excellent shape retention when dry and shape retention when wet.

[Seventh aspect]
(Constitution)
According to a seventh aspect of the present invention, the first absorbent core layer and the second absorbent core layer which are in contact with the first core wrap sheet portion or the second core wrap sheet portion constituting the intermediate joint portion. One of the absorbent core layers has a superabsorbent polymer-free region where the superabsorbent polymer does not exist in the thickness direction, and the intermediate bonding portion includes the superabsorbent polymer-free region and the thickness. The absorbent body according to the sixth aspect, wherein the absorbent body overlaps in a vertical direction.

(effect)
According to a seventh aspect of the present invention, a first absorbent core layer or a second absorbent core in contact with a first core wrap sheet portion or a second core wrap sheet portion constituting an intermediate joint portion Since the superabsorbent polymer-free region exists in the layer, even when the superabsorbent polymer swells, the bodily fluid penetrates into the absorber through the superabsorbent polymer-free region. Excellent in repeated absorption. Further, since the intermediate joint portion overlaps the superabsorbent polymer-free region in the thickness direction, even when the superabsorbent polymer swells, the intermediate joint portion maintains the joint structure and absorbs. Excellent body shape retention when wet.

[Eighth aspect]
(Constitution)
An eighth aspect of the present invention is the absorbent body according to the seventh aspect, wherein the superabsorbent polymer-free region extends in the longitudinal direction.

(effect)
According to the eighth aspect of the present invention, since the bodily fluid diffuses in the longitudinal direction via the superabsorbent polymer-free region, the absorption area ratio of the absorber is high and the bodily fluid repetitive absorbability is excellent.

[Ninth embodiment]
(Constitution)
A ninth aspect of the present invention is the absorbent body according to any one of the first to eighth aspects, wherein the first surface is a skin side surface, and the second surface is a clothing side surface.

(effect)
According to the ninth aspect of the present invention, since the first core wrap sheet portion having the water-absorbent nonwoven fabric is disposed on the skin side, the water-absorbent nonwoven fabric is absorbed before the body fluid is absorbed by the absorber. And a part of the body fluid penetrates into the water-absorbent nonwoven fabric, so that the first core wrap sheet portion is more easily stretched when the body fluid is absorbed.

[Tenth aspect]
(Constitution)
According to a tenth aspect of the present invention, the first core wrap sheet portion includes a center sheet portion disposed closer to the center in the width direction, and a pair of outer sheet portions disposed on both outer sides in the width direction. Wherein the first core wrap sheet portion is a pair of overlapping portions, wherein the central sheet portion overlaps each of the pair of outer sheet portions in the thickness direction, The absorbent body according to the ninth aspect, wherein the absorbent body includes an absorbent body.

(effect)
According to the tenth aspect of the present invention, the first core wrap sheet portion has a pair of overlapping portions extending in the longitudinal direction, and the pair of overlapping portions has a high fiber density. Has a high absorption area ratio, and is excellent in repeated absorption of bodily fluids.

[Eleventh aspect]
(Constitution)
In an eleventh aspect of the present invention, in each of the pair of overlapping portions, each of the pair of outer sheet portions is disposed closer to the upper surface than the central sheet portion, and the pair of outer sheet portions is provided. The absorbent body according to the tenth aspect, wherein each of the edge portions on the side of the central sheet portion is separated from the central sheet portion.

(effect)
According to the eleventh aspect of the present invention, when the widthwise intermediate portion of the laminated absorbent core absorbs bodily fluid and swells, the upper surface of the absorbent body is inclined, so that the edge of the outer sheet portion overlapping the central sheet portion is reduced. It rises from the surface of the central sheet portion, and becomes in a standing state. This allows the edge of the outer sheet portion to function as a leak-proof wall.

[Twelfth aspect]
(Constitution)
According to a twelfth aspect of the present invention, the absorber is divided into width-direction both ends arranged at both ends in the width direction, and a width-direction intermediate portion sandwiched between the width-direction ends, and the absorber is The absorber according to any one of the first to eleventh modes, wherein the absorber is provided at each of both ends in the width direction.

(effect)
According to the twelfth aspect of the present invention, the joint portion is located at each of both ends in the width direction of the absorber. The core wrap sheet portion is supported, and the absorbent has excellent shape retention when wet.

[Thirteenth aspect]
(Constitution)
A thirteenth aspect of the present invention is the absorbent article according to the twelfth aspect, wherein the width dimension of the first absorbent core layer is smaller than the width dimension of the second absorbent core layer. Body.

(effect)
According to the thirteenth aspect of the present invention, since the superabsorbent polymer derived from the first absorbent core layer does not exist at the position where the joint is located, the swelling of the superabsorbent polymer due to water absorption causes the joining. The mechanical strength of the portion is not easily impaired, and the absorbent has excellent shape retention when wet.

[14th aspect]
(Constitution)
In a fourteenth aspect of the present invention, the core wrap sheet has an elongation of 30% or more in each of the wet tensile test and the dry tensile test, and has a tensile strength at 30% elongation in the wet tensile test of 30% or more. 14. The absorbent body according to any one of the first to thirteenth aspects, wherein the absorbent has a tensile strength at 30% elongation of 30% or less in the dry tensile test.

(effect)
According to the fourteenth aspect of the present invention, since the core wrap sheet has a tensile strength at 30% elongation in the wet tensile test smaller than the tensile strength at 30% elongation in the dry tensile test, the swelling of the superabsorbent polymer is achieved. The core wrap sheet is easy to follow, and the absorption performance of the highly absorbent polymer is enhanced. Further, since the tensile strength at 30% elongation in the dry tensile test of the core wrap sheet is greater than the tensile strength at 30% elongation in the wet tensile test, the core wrap sheet is excellent in shape retention during drying.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan development view of a tape-stop type disposable diaper 1 (hereinafter, also simply referred to as “disposable diaper”) including an absorber 17 according to the present embodiment, and FIG. 2 is a W ₁ -W diagram of FIG. in _one plane, a cross-sectional view of the absorbent body 17 before the body fluid absorbent, Figure 3, in W ₁ -W ₁ side of FIG. 1 is a cross-sectional view of the absorber 17 after fluid absorption. As shown in FIGS. 1 and 2, the absorber 17 of the present embodiment has a first surface 34 and a second surface 35 and has a longitudinal direction L, a width direction W, and a thickness direction T that are orthogonal to each other. And is divided along the width direction W into both width direction end portions E and width direction intermediate portions C. Here, the width direction intermediate portion C refers to a region extending about 70% of the width direction W around the center point in the width direction W at the portion having the largest dimension in the width direction W, Each area of about 15% is defined as both ends E in the width direction. In addition, the longitudinal direction L, the width direction W, and the thickness direction T of the disposable diaper 1 match the longitudinal direction L, the width direction W, and the thickness direction T of the absorber 17. The absorbent article of the present invention is not limited to a tape-stop type disposable diaper, and may be, for example, a pants-type disposable diaper, a urine absorbing pad, a light incontinence pad, a sanitary pad, and a panty liner.

  The disposable diaper 1 includes a liquid-permeable top sheet 3, a liquid-impermeable back sheet 5, and an absorber 17 of the present embodiment disposed between the top sheet 3 and the back sheet 5. A leak-proof wall 7 having a member 9, a tape fastener 15 and the like are provided. Further, in the present embodiment, the top sheet 3 and the top sheet 3 are arranged such that the first surface 34 of the absorber 17 is located on the top sheet 3 side of the disposable diaper 1 and the second surface 35 is located on the back sheet 5 side of the disposable diaper 1. It is arranged between the backsheets 5. However, in the present invention, the first surface of the absorber may be arranged on the backsheet side of the absorbent article, and the second surface of the absorber may be arranged on the backsheet side of the absorbent article.

<Absorber>
As shown in FIG. 1, the absorbent body 17 of the present embodiment is used for a disposable diaper 1. Then, as shown in FIG. 2, the absorber 17 of the present embodiment includes a first absorbent core layer 18, an intermediate layer 19, and a second absorbent core layer from the first surface 34 to the second surface 35. 20 has a laminated absorbent core 21 and a core wrap sheet 26 laminated in this order, and the first absorbent core layer 18 and the second absorbent core layer 20 contain a superabsorbent polymer. The core wrap sheet 26 is a surface parallel to the width direction W and the longitudinal direction L passing through the center in the thickness direction T at a portion having the largest dimension in the thickness direction T of the absorber 17. The first core wrap sheet portion 24 located closer to the first surface 34 than the center plane Tc in the thickness direction, and the second core positioned closer to the second surface 35 than the center plane Tc in the thickness direction of the absorber 17. And a wrap sheet portion 25. In the present embodiment, the absorber 17 has a joint portion 29 where the intermediate layer 19 and the first core wrap sheet portion 24 and the second core wrap sheet portion 25 are joined.

  In the present invention, the first core wrap sheet portion has a water-absorbent nonwoven fabric made of a water-absorbent fiber containing a water-absorbent fiber having a fiber length of 25 mm or more entangled with each other. Is greater than the elongation in a dry tensile test, the tensile strength in a wet tensile test is lower than the tensile strength in a dry tensile test, and the intermediate layer is heat-sealed in which a plurality of thermoplastic synthetic fibers are fused. The heat-sealed nonwoven fabric has an elongation and a tensile strength in a wet tensile test of 90% or more and a 110% or less of the dry tensile test in a dry tensile test, respectively.

  As described above, in the present embodiment, the intermediate layer 19 has a small change in its elongation characteristics even when absorbing water, and the first core wrap sheet portion 24 is joined to the intermediate layer 19. Therefore, as shown in FIG. 3, the absorbent polymer absorbs water and swells, so that even if the first core wrap sheet portion 24 is elongated (deformed), it is absorbed by the intermediate layer 19 which is hardly elongated (deformed). The deformation of the whole body 17 can be suppressed. Thereby, the absorbent body 17 is excellent in the shape retention property when wet, which retains the shape when wet.

  In the intermediate layer 19 included in the absorber 17 of the present embodiment, the thermoplastic fibers are fused together, and the characteristics with respect to the load hardly change between when dry and when wet, so that the intermediate layer expands when wet. As shown in FIG. 3, when a load is applied, for example, the superabsorbent polymer of the first absorbent core layer 18 and the second absorbent core layer 20 absorbs water and expands. Even in this case, the intermediate layer 19 is not easily crushed. Therefore, in the above-mentioned absorber 17, the intermediate layer 19 is excellent in the liquid permeability, which is the permeability of the body fluid, and hardly inhibits the diffusion of the body fluid even under the condition in which the superabsorbent polymer swells. However, it is excellent in repeated absorption of bodily fluids that repeatedly absorbs bodily fluids.

  Furthermore, at least the first core wrap sheet portion 24 of the core wrap sheet 26 included in the absorbent body 17 of the present embodiment is made of water-absorbing fibers including water-absorbing fibers having a fiber length of 25 mm or more that are entangled with each other. It has a water-absorbent nonwoven fabric whose elongation in the tensile test at dry time is larger than that at the tensile test at dry time, and whose tensile strength at the tensile test at wet is lower than the tensile strength at the tensile test at dry time. The first core wrap sheet portion 24 made of a water-absorbing nonwoven fabric has a property of easily expanding when wet by absorbing body fluid, but as shown in FIG. 3, when the absorbent 17 absorbs water, the first core wrap sheet portion 24 24 absorbs the bodily fluid permeating from the first surface 34 side and extends relatively easily. Therefore, the first core wrap sheet portion 24 extends, so that the absorption performance of the superabsorbent polymer can be enhanced.

  The absorber of the present invention preferably has a thickness of 0.8 mm or more and 3 mm or less.

[Core wrap sheet]
As shown in FIG. 2, in the absorbent body 17 of the present embodiment, the core wrap sheet 26 includes a first core wrap sheet portion 24 and a second core wrap sheet portion 25, and the first core wrap sheet The part 24 has a water-absorbent nonwoven fabric made of water-absorbent fibers. In the present embodiment, the core wrap sheet 26 encloses the laminated absorbent core 21 by wrapping the laminated absorbent core 21 around the width direction W.

(First core wrap sheet part)
As shown in FIG. 2, in the absorber 17 of the present embodiment, the first core wrap sheet portion 24 includes the laminated absorbent core 21 together with the second core wrap sheet portion 25. The first core wrap sheet portion 24 is a separate sheet separated from the second core wrap sheet portion 25. The first core wrap sheet portion 24 and the second core wrap sheet portion 25 have both ends in the width direction W joined to each other along the longitudinal direction L. However, in the present invention, the first core wrap sheet portion may not be joined to the second core wrap sheet portion, or may be a single sheet integrally formed with the second core wrap sheet portion. May be a part of. Further, at least one of the first core wrap sheet portion and the second core wrap sheet portion may be in a state where at least a part of the plurality of sheets is joined.

In the present invention, the first core wrap sheet portion preferably has a basis weight of 15 g / m ² or more and 200 g / m ² or less, more preferably 25 g / m ² or more and 150 g / m ² or less. Is preferably 0.1 mm or more and 2 mm or less, more preferably 0.2 mm or more and 1.5 mm or less. By setting the basis weight and the thickness of the first core wrap sheet portion within the above ranges, it is possible to achieve a balance between the extension characteristics and the strength of the first core wrap sheet portion.

(Joint)
In the absorbent body 17 of the present embodiment, a joining portion 29 in which an intermediate layer 19 described later and each of the first core wrap sheet portion 24 and the second core wrap sheet portion 25 are joined at both end portions E in the width direction. Having. In the present embodiment, the intermediate layer 19 whose elongation characteristics change little even when water is absorbed is joined to the first core wrap sheet portion 24 and the second core wrap sheet portion 25, so that FIG. As shown in the drawing, the superabsorbent polymer absorbs water and swells, so that even if the first core wrap sheet portion 24 and the second core wrap sheet portion 25 are elongated (deformed), it is difficult to stretch (deform). The layer 19 can suppress deformation of the absorber 17 as a whole. Therefore, the absorbent body 17 is excellent in wet-state shape retention in which the form is maintained when wet. In the present invention, the joining portion is not limited to the joining portion formed by joining the intermediate layer, the first core wrap sheet portion, and the second core wrap sheet portion. It may be formed by joining one of the wrap sheet portion and the second core wrap sheet portion. However, the joint portion is formed by joining the first core wrap sheet portion and the second core wrap sheet portion together with the intermediate layer. It is more preferable in terms of the shape retention of the absorbent body when wet than when one of the core wrap sheet portions is formed in combination with the intermediate layer.

  In the absorber 17 of the present embodiment, the joints 29 are located at both ends E in the width direction. 3, the core wrap sheet 26 is supported by the intermediate layer 19 having high resistance to tensile stress even when the absorber 17 absorbs water, as shown in FIG. Therefore, the shape retention of the absorber 17 when wet is improved. However, in the present invention, the position of the joint is not limited to the width direction both ends E of the absorber.

(Water absorbent nonwoven fabric)
In the absorbent body 17 of the present embodiment, the first core wrap sheet portion 24 has the above-described water-absorbent nonwoven fabric. Since the water-absorbent nonwoven fabric is formed by entanglement, the bonding between the fibers of the water-absorbent nonwoven fabric is likely to be weakened with water absorption. Further, the water-absorbing fiber is easily stretched when absorbing water. Furthermore, since the water-absorbing fiber contains a sufficiently long water-absorbing fiber having a fiber length of 25 mm or more, when the bonding force between the water-absorbing fibers is weakened, the water-absorbing nonwoven fabric easily extends without breaking. At the same time, the water-absorbent nonwoven fabric is easily extended by the extension of the water-absorbent fibers. Furthermore, since the water-absorbent nonwoven fabric has the property of being easily stretched when wet compared to when dry, the shape of the absorber 17 is prevented from being lost when an external force is applied before water absorption, and the water-absorbent nonwoven fabric has a water-absorbing property after water absorption. The nonwoven fabric is easy to stretch. Therefore, when the absorbent 17 absorbs water, the first core wrap sheet portion 24 absorbs the bodily fluid penetrating from the skin side surface or the bodily fluid staying on the clothing side surface, and follows the swelling of the highly absorbent polymer. Stretches relatively easily. Thereby, the first core wrap sheet portion is elongated, so that the absorption performance of the superabsorbent polymer can be enhanced.

  In the absorbent body 17 of the present embodiment, the first core wrap sheet portion 24 has a property of easily expanding when wet, so that the first absorbent core layer 18 absorbs body fluid as shown in FIG. Even when the superabsorbent polymer swells toward the first surface 34, the first core wrap sheet portion 24 can follow the swelling and absorb the superabsorbent polymer, and hence the absorbent 17 Performance can be enhanced. In the present embodiment, the second core wrap sheet portion 25 also has a water-absorbing nonwoven fabric having the above characteristics, and as shown in FIG. 3, the second absorbent core layer 20 absorbs bodily fluids. Then, even when the superabsorbent polymer swells toward the second surface 35, the second core wrap sheet portion 25 can follow the swelling, and the absorption performance of the absorber 17 can be enhanced. it can. However, in the present invention, the second core wrap sheet portion does not necessarily have to have the water-absorbing nonwoven fabric.

  In the present invention, the water-absorbent nonwoven fabric has an elongation of 30% or more in each of the wet tensile test and the dry tensile test, and the tensile strength when the water-absorbent nonwoven fabric is stretched by 30% in the wet tensile test. It is preferable that the tensile strength at 30% elongation is 25% or less of the tensile strength at 30% elongation in the dry tensile test. This makes it easy for the core wrap sheet to follow the swelling of the superabsorbent polymer, which enhances the absorption performance of the superabsorbent polymer and that the absorbent body is less likely to lose its shape before absorbing water. Also excellent in nature.

  More specifically, in the present invention, the maximum elongation in the wet tensile test of the water-absorbent nonwoven fabric is preferably 50% or more and 200% or less in the CD direction, and the 30% tensile strength in the CD direction is 0%. It is preferably from 0.01 N / 25 mm to 1 N / 25 mm, and the maximum tensile strength in the CD direction is preferably from 1 N / 25 mm to 15 N / 25 mm. Further, the maximum elongation in the dry tensile test of the water-absorbent nonwoven fabric is preferably from 40% to 190% in the CD direction, and the 30% tensile strength in the CD direction is from 0.1N / 25mm to 5N. / 25 mm or less, and the maximum tensile strength in the CD direction is preferably 1.2 N / 5 mm or more and 20 N / 25 mm or less. In the present invention, the CD direction of the water-absorbent nonwoven fabric preferably corresponds to the width direction W of the absorbent article.

  In the present invention, the water-absorbent fibers having a fiber length of 25 mm or more contained in the water-absorbent fibers constituting the water-absorbent nonwoven fabric are preferably regenerated cellulose fibers (for example, rayon fibers), and more preferably rayon fibers. . Regenerated cellulose fibers such as rayon fibers are more excellent in fiber uniformity (fiber length, fiber diameter, etc.) than pulp fibers, so that the first core wrap sheet portion has better stretchability when wet. The absorption performance of the superabsorbent polymer in the absorber becomes excellent. On the other hand, the water-absorbent nonwoven fabric formed by entanglement of regenerated cellulose fibers such as rayon fibers, when a load is applied from the outside of the absorber, or when it is intended to elongate with a certain amount of displacement or more, Since a relatively high tensile tension acts, the shape retention of the absorbent body when wet can be improved.

  In the absorbent body of the present invention, the water-absorbent nonwoven fabric of the first core wrap sheet portion is preferably a spunlace nonwoven fabric made of water-absorbing fibers, and is preferably a spunlace nonwoven fabric made of regenerated cellulose fibers. More preferably, there is. The spunlaced nonwoven fabric is a nonwoven fabric in which entanglement between fibers easily occurs, so that the water-absorbent nonwoven fabric is easily stretched, and the absorbency of the superabsorbent polymer is increased.

  In this case, the water-absorbing fiber may contain a water-absorbing fiber having a fiber length of less than 25 mm, but preferably mainly contains a water-absorbing fiber having a fiber length of 25 mm or more, and preferably has a fiber length of 25 mm or more. More preferably, it consists of only As the spunlace nonwoven fabric composed of such water-absorbing fibers, the fibers constituting the nonwoven fabric can be exemplified by spunlace nonwoven fabrics mainly composed of rayon, but from the viewpoint of the elongation characteristics when absorbing moisture, the nonwoven fabric is formed. A spunlace nonwoven fabric in which at least 85% by mass of the fiber is rayon is preferable, a spunlace nonwoven fabric in which at least 90% by mass is rayon is more preferable, and a spunlace nonwoven fabric consisting only of rayon is further preferable. .

  In the present invention, as a fiber component other than the regenerated cellulose fiber constituting the spunlaced nonwoven fabric, any hydrophilic fiber can be mentioned. Pulp fibers can be mentioned as such a hydrophilic nonwoven fabric. For example, the spunlaced nonwoven fabric may be a spunlaced nonwoven fabric containing rayon fibers and pulp fibers. The spun lace nonwoven fabric containing rayon fiber and pulp fiber includes an upper layer of 80% to 100% rayon fiber, an intermediate layer of 80% to 100% pulp fiber, and 80% to 100% of rayon fiber. A spunlace nonwoven fabric comprising a lower layer can be exemplified.

(High density part and low density part)
FIG. 4 is an enlarged perspective view of the water-absorbent nonwoven fabric included in the first core wrap sheet portion 24. As shown in FIG. 4, the water-absorbent nonwoven fabric included in the absorbent body 17 of the present embodiment extends along the longitudinal direction L and is arranged along the width direction W, and has a fiber density of the water-absorbent fibers. The high density of the water-absorbing fibers, which extends along the longitudinal direction L and the plurality of high-density portions 32 and is disposed between the high-density portions 32 adjacent to each other, is low. , A plurality of low-density portions 33. Since the plurality of high-density portions 32 easily diffuse the body fluid in the longitudinal direction L, the first core wrap sheet portion 24 absorbs the body fluid that has permeated from the skin side surface, and easily diffuses the body fluid in the longitudinal direction L. I do. Thereby, the body fluid can be absorbed widely to the vicinity of both ends in the longitudinal direction L of the absorber 17, so that the absorber 17 of the present embodiment has the entire area of the surface including the longitudinal direction L and the width direction W. The absorption area ratio, which is the ratio of the area of the portion that has absorbed the bodily fluid, is increased. As a result, the absorber 17 is excellent in the above-described bodily fluid repetitive absorbability. Further, in the present embodiment, the plurality of low-density portions 33 can easily make the water-absorbent nonwoven fabric stretch in the width direction W of the absorber 17. For this reason, the absorption performance of the superabsorbent polymer included in the absorber 17 of the present embodiment can be enhanced.

  Note that, in the absorbent body of the present invention, the first surface is not limited to the mode in which the first surface is disposed on the skin side surface, and may be disposed on the clothing side surface. When the absorber absorbs water, the first core wrap sheet portion absorbs the bodily fluid that has passed through the absorber and facilitates diffusion of the bodily fluid in the longitudinal direction.

  In the present embodiment, the water-absorbent nonwoven fabric has, as shown in FIG. 4, irregularities that are repeatedly present in the high-density portion 32 adjacent to the width direction W, in which convex portions and concave portions are located. The height difference t between the concave portion and the convex portion on one surface of the core wrap sheet 26 in the thickness direction T is about one time the thickness d of the core wrap sheet 26. In the present invention, the height difference between the concave portion and the convex portion is preferably 3 times or less, more preferably 2.5 times or less, and more preferably 1.2 times or less the thickness d of the core wrap sheet. Is more preferred.

  In the present invention, the distance in the width direction of the adjacent high-density portion is preferably 0.1 mm or more and 1 mm or less, and the distance in the width direction of the adjacent low-density portion is 0.3 mm or more and 4 mm or less. Is preferred. In the case where one adjacent low-density part and one high-density part are taken as one unit, the distance of the repeating unit is preferably 0.4 mm or more and 5 mm or less. In addition, it is preferable that high-density portions are arranged at both ends in the width direction of the water-absorbent nonwoven fabric. In this case, the width-direction dimensions of the high-density portions located at both ends in the width direction are 3 mm or more and 20 mm or more. The following is preferred.

  In the present invention, the water-absorbing fibers located in the high-density portion have an orientation along the longitudinal direction, and the water-absorbing fibers located in the low-density portion are more oriented than the fibers located in the high-density portion. Is preferably low. Thereby, in a high-density part where the density of the water-absorbing fiber is high, the body fluid is easily diffused in the longitudinal direction.

(Center sheet part and outer sheet part)
In the present embodiment, the first core wrap sheet portion 24 includes a center sheet portion 22 disposed at a position closer to the center in the width direction W, and a pair of outer sheet portions 23 disposed on both outer sides in the width direction W. Both ends of the central sheet portion 22 in the width direction W overlap the ends of the pair of outer sheet portions 23 in the width direction W near the central sheet portion 22 in the thickness direction T, The pair of overlapping portions 27 extending in the longitudinal direction L overlap each other. Since the first core wrap sheet portion 24 has the above-described configuration, the fiber density of the water-absorbing fibers in the pair of overlapping portions 27 can be further increased, and in the pair of overlapping portions 27, along the longitudinal direction L. The body fluid can be more easily diffused. Thereby, the absorber 17 is excellent in the body fluid repetitive diffusion property. In the present embodiment, the central sheet portion 22 constitutes one sheet, and the second core wrap sheet portion 25 and the pair of outer sheet portions 23 integrally form another sheet. Constitute.

  As shown in FIG. 3, in the present embodiment, in each of the pair of overlapping portions 27, each of the pair of outer sheet portions 23 is disposed closer to the first surface 34 than the central sheet portion 22. An edge 31 of the pair of outer sheet portions 23 on the side of the central sheet portion 22 is separated from the central sheet portion 22. By adopting such a configuration, when the width direction intermediate portion C of the laminated absorbent core 21 absorbs a bodily fluid and swells, the first surface 34 of the absorbent body 17 is inclined and overlaps with the central sheet portion 22. The edge 31 of the outer sheet portion 23 rises from the surface of the central sheet portion 22, and the edge 31 of the outer sheet portion 23 can function as a leak-proof wall.

  In the present invention, the “outer sheet portion” and the “center sheet portion” are provided in the first core wrap sheet portion, but the outer sheet portion and the center sheet portion are different core wrap portions separated from each other. It is preferable that at least a part of each of the sheets is constituted. Further, in the present invention, the first core wrap sheet portion and the second core wrap sheet portion each form a single separated sheet, and the first core wrap sheet portion and the second core wrap sheet portion are separated from each other. The core wrap sheet portion may be joined along the longitudinal direction at both ends in the width direction.

  In the absorber 17 in the present embodiment, the dimension of the first absorbent core layer 18 in the width direction W is smaller than the dimension of the second absorbent core layer 20 in the width direction W. Are arranged at both ends E in the width direction. By adopting such a configuration, since the superabsorbent polymer derived from the first absorbent core layer 18 does not exist in the portion where the pair of overlapping portions 27 exist, the body fluid extends the pair of overlapping portions 27 in the longitudinal direction. While diffusing in the direction L, the second absorbent core layer 20 is easily penetrated, and the absorbent 17 has excellent body fluid repetitive absorbability.

  Furthermore, in the present embodiment, the high-density portions 32 are disposed at both ends in the width direction W of the central sheet portion 22, and the high-density portions 32 are disposed at both ends in the width direction W of the sheet including the outer sheet portion 23. ing. By adopting such a configuration, the fiber density of the water-absorbing fibers of the pair of overlapping portions 27 is higher, the liquid permeability along the longitudinal direction L is further improved, and the liquid in the pair of overlapping portions 27 is improved. The diffusivity can be made more excellent, and the body fluid repetitive absorbability of the absorber 17 is excellent.

  As shown in FIG. 3, in the present embodiment, the center sheet portion 22 constitutes one sheet, and the outer sheet portion 23 is integrated with the second core wrap sheet portion 25 to form one sheet. Make up the sheets. Therefore, in the present embodiment, a sheet corresponding to the central sheet portion 22 and a sheet constituted by the outer sheet portion 23 and the second core wrap sheet portion 25 are formed by a pair of overlapping portions extending in the longitudinal direction L. 27 will be formed. However, the configuration of the core wrap sheet in the present invention is not limited to such a configuration.

(Second core wrap sheet part)
The absorber 17 of the present embodiment has the second core wrap sheet portion 25 located on the second surface 35 side of the center plane Tc in the thickness direction of the absorber 17. In the present embodiment, the nonwoven fabric forming the second core wrap sheet portion 25 is made of a water-absorbing nonwoven fabric, similarly to the first core wrap sheet portion 24, and includes the first core wrap sheet portion 24 and Although both of the second core wrap sheet portions 25 are made of the water-absorbent nonwoven fabric, the second core wrap sheet portion of the present invention is not limited to the one having the water-absorbent nonwoven fabric.

(Intermediate joint)
As shown in FIG. 2, in the present embodiment, the absorber 17 includes, in the widthwise intermediate portion C, an intermediate joint portion 30 in which an intermediate layer 19 and a second core wrap sheet portion 25 described later are joined. . Thereby, the absorber 17 is excellent in shape retention when dry and shape retention when wet. However, in the present invention, the intermediate joining portion may be formed by joining the first core wrap sheet and the intermediate layer.

[Laminated absorbent core]
The laminated absorbent core 21 included in the absorbent body 17 of the present embodiment has a structure in which a first absorbent core layer 18, an intermediate layer 19, and a second absorbent core layer 20 are laminated in this order via an adhesive. It is. In the present embodiment, the laminated absorbent core 21 has a substantially rectangular planar shape whose dimension in the longitudinal direction L is longer than the dimension in the width direction W and a substantially rectangular parallelepiped shape having a constant thickness. The shape of the laminated absorbent core in the present invention is not limited to such a shape, and any planar shape can be adopted as long as the function of absorbing and retaining the liquid of the laminated absorbent core is not hindered. As described below, the first absorbent core layer and the second absorbent core layer included in the laminated absorbent core of the present invention preferably contain a superabsorbent polymer, and preferably contain pulp fibers as necessary. The basis weight of the superabsorbent polymer in the entire absorbent body of the present invention is preferably 50 g / m ² or more and 500 g / m ² or less, and the pulp fiber basis weight is 0 g / m ² or more and 1000 g / m ² or less. Preferably, there is. Further, the ratio of the basis weight of the superabsorbent polymer contained in the entire absorbent body of the present invention to the basis weight of the pulp fiber is preferably from 1: 6 to 6: 0. In the present invention, examples of the adhesive used for forming the laminated absorbent core as necessary include a hot melt adhesive. The absorber of the present invention is not necessarily limited to one that requires an adhesive to form a laminated absorbent core.

(First absorbent core layer)
The first absorbent core layer 18 included in the absorber 17 of the present embodiment includes a high-absorbent polymer supported by an adhesive. It is in a state of being sandwiched by the first core wrap sheet portion 24. In the first absorbent core layer 18 included in the absorbent body 17 of the present embodiment, the superabsorbent polymer is arranged substantially uniformly in the plane direction. In the present invention, the basis weight of the superabsorbent polymer in the first absorbent core layer is preferably from 25 g / m ^{2 to} 250 g / m ² . By setting the basis weight of the superabsorbent polymer within the above range, the absorbent body of the present invention can sufficiently absorb the bodily fluid in the excrement, and can prevent blocking due to the swollen superabsorbent polymer. To some extent. Further, in the present invention, the first absorbent core layer may have pulp fibers, and in that case, the basis weight of the pulp fibers is preferably larger than 0 g / m ² and 500 g / m ² or less. By including pulp fibers in the first absorbent core layer, the absorption rate of the absorber can be increased, but when no pulp fibers are contained, the absorber can be made thin. The ratio between the basis weight of the superabsorbent polymer and the basis weight of the pulp fibers in the first absorbent core layer is preferably from 1: 6 to 6: 0.

  In the absorber 17 of the present embodiment, the dimension of the first absorbent core layer 18 in the width direction W is smaller than the dimension of the second absorbent core layer 20 described later in the width direction W over the entire length in the longitudinal direction L. Here, the first absorbent core layer 18 is arranged so that the center line in the width direction W thereof substantially overlaps the center line in the width direction W of the absorber 17. Both ends in the width direction W are located closer to the center in the width direction W than to each end of the second absorbent core layer 20 in the width direction W. In the present embodiment, by adopting such a configuration, even when the bodily fluid becomes difficult to be absorbed by the first absorbent core layer 18, the surface of the first absorbent core layer 18 causes the bodily fluid to extend in the width direction W. As a result, it is possible to reach the surface of the wide second absorbent core layer 20. That is, the bodily fluid that has not been absorbed by the first absorbent core layer 18 can be absorbed by the second absorbent core layer 20, and the absorbent 17 is discharged even when the bodily fluid is repeatedly discharged. It can absorb bodily fluids and is excellent in body fluid repeated absorption. Further, as described above, in the present embodiment, the joints 29 are provided at both ends E in the width direction, but the first absorbent core layer 18 and the second absorbent core Since the superabsorbent polymer derived from the layer 20 does not exist, the mechanical strength of the joint 29 is not easily impaired by the swelling of the superabsorbent polymer due to the water absorption, and the shape retention of the absorber 17 when wet is improved. It will be excellent.

  In the present invention, "the width dimension of the first absorbent core layer" and "the width dimension of the second absorbent core" refer to the first absorbent core layer and the second absorbent core layer. , The maximum length of the region sandwiched between the outermost edges in the width direction. In the present invention, the width dimension of the first absorbent core layer may be larger than the width dimension of the second absorbent core layer, and may be the same as the width dimension of the second absorbent core layer. You may. Similarly, in the present invention, “the longitudinal dimension of the first absorbent core layer” and “the longitudinal dimension of the second absorbent core” refer to the first absorbent core layer and the second absorbent core layer. Means the maximum length of the region sandwiched between the outermost edges in the longitudinal direction. In the present invention, the longitudinal dimension of the first absorbent core layer may be larger or smaller than the longitudinal dimension of the second absorbent core layer, and may be different from the longitudinal dimension of the second absorbent core layer. It may be the same.

(Superabsorbent polymer)
The superabsorbent polymer included in the absorber of the present invention is intended to absorb and retain the liquid in the excrement in the absorber, and the type thereof is limited as long as the object can be achieved. Not something. In the present invention, as the superabsorbent polymer, more specifically, polyaspartate-based polymer, sodium polyacrylate-based polymer, isobutylene-maleic anhydride copolymer, starch-acrylic acid graft copolymer And acrylic acid-vinyl alcohol copolymer.

  Here, in the present invention, among the above polymers and copolymers, it is preferable to use a superabsorbent polymer that is a granulated product of a polymer or a copolymer obtained by reversed phase suspension polymerization. A superabsorbent polymer that is a granulated product of a polymer or a copolymer obtained by reverse phase suspension polymerization, a composition containing a polymerizable monomer in the presence of a surfactant or an emulsifier, as a water-in-oil emulsion, It is a granulated product of a polymer or a copolymer obtained by performing a polymerization reaction. Since the granulated product of such a superabsorbent polymer has a larger surface area than a spherical superabsorbent polymer having the same volume, the specific surface area of the granulated product of the superabsorbent polymer is large, and the high absorption is high. The absorption rate of the hydrophilic polymer increases. Examples of such superabsorbent polymers include those obtained by the production method described in JP-A-57-094011.

(Intermediate layer)
As shown in FIG. 2, the laminated absorbent core 21 in the absorbent body 17 of the present embodiment has a plurality of thermoplastic synthetic fibers between the first absorbent core layer 18 and the second absorbent core layer 20. An intermediate layer 19, which is a heat-sealed nonwoven fabric attached, is interposed. In the present embodiment, the characteristics of the intermediate layer 19 with respect to the load between the dry state and the wet state are unlikely to change, so that the intermediate layer 19 does not easily elongate during the wet state and, as shown in FIG. Even when the superabsorbent polymer of the core layer 18 and the second absorbent core layer 20 receives a load by absorbing water and expanding, the intermediate layer 19 is not easily crushed. Therefore, the absorbent body 17 according to the present embodiment is excellent in liquid permeability because the intermediate layer 19 easily passes the body fluid in the longitudinal direction L and the width direction W even under the condition in which the superabsorbent polymer swells. Since the diffusibility of the bodily fluid is not easily inhibited, the contact area between the absorber 17 and the bodily fluid is increased, and the absorber 17 is excellent in the repetitive bodily fluid absorbability.

  In the present embodiment, since the intermediate layer 19 is required to have relatively high physical strength, the intermediate layer 19 has no three-dimensional unevenness formed by gear processing or embossing described later. ing. By making the intermediate layer 19 not subjected to gear processing or embossing, it is possible to increase resistance to an external load such as tensile stress. However, in the present invention, as long as the elongation and tensile strength in the wet tensile test fall within the range of 90% or more and 110% or less of the elongation and tensile strength in the dry tensile test, unevenness is formed on the intermediate layer. Then, the apparent bulkiness of the intermediate layer may be improved, or the performance of retaining the superabsorbent polymer may be improved.

  In the present invention, the heat-fused nonwoven fabric constituting the intermediate layer has an elongation and a tensile strength in a wet tensile test of 90% or more and 110% or less of a dry tensile test, respectively. Is within. In the present invention, the heat-sealing nonwoven fabric is preferably an air-through nonwoven fabric composed of thermoplastic synthetic fibers. Further, it is preferable that the heat-sealing nonwoven fabric has been subjected to a hydrophilic treatment as necessary. Since the air-through nonwoven fabric is bulky and excellent in cushioning properties, even when the first absorbent core layer and the second absorbent core layer are swollen, the liquid permeability of the intermediate layer is hardly inhibited, and the absorbent of the present invention has Excellent body fluid repetitive absorption.

  In the present invention, it is preferable to use a core-in-sheath composite fiber using a thermoplastic resin as a sheath component constituting at least the fiber surface, as the thermoplastic synthetic fiber constituting the air-through nonwoven fabric. By using a thermoplastic resin as the sheath component constituting the fiber surface, the fiber exhibits heat-sealing properties, so that the resin component used as the core component can be appropriately selected according to the required physical properties of the intermediate layer. . For example, by using a composite fiber using a relatively strong resin component as a core component that does not constitute a fiber surface as the core-sheath type composite fiber, it has stronger resistance to tensile stress and the like. An intermediate layer can be provided. Here, as the resin that can be used as the core component and the sheath component, for example, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ionomer resin Polyolefins such as, for example, polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyesters such as polylactic acid; polyamides such as nylon; and the like can be used in combination. In the present invention, it is preferable to use a polyolefin-based resin such as polyethylene or polypropylene as the sheath component, and to use the above-mentioned polyolefin-based resin or polyethylene terephthalate as the core component, for the purpose of achieving both heat-fusibility and tensile strength. It is preferable to use the polyester-based resin.

  In the present invention, the maximum elongation in the wet tensile test of the heat-fused nonwoven fabric is preferably 20% or more and 150% or less in the CD direction, and the 30% tensile strength in the CD direction is 0.3 N /. The tensile strength is preferably 25 mm or more and 6 N / 25 mm or less, and the maximum tensile strength in the CD direction is preferably 5 N / 25 mm or more and 30 N / 25 mm or less. Further, in the present invention, the maximum elongation in the dry tensile test of the heat-fused nonwoven fabric is preferably 20% or more and 150% or less in the CD direction, and the 30% tensile strength in the CD direction is 0.1% or less. The tensile strength is preferably 3 N / 25 mm or more and 6 N / 25 mm or less, and the maximum tensile strength in the CD direction is preferably 5 N / 25 mm or more and 30 N / 25 mm or less. By setting the elongation and the tensile strength of the heat-fused nonwoven fabric within the above ranges, the absorbent body is excellent in shape retention when wet and body fluid repeated absorption.

In the present invention, the intermediate layer preferably has a basis weight of 9 g / m ² or more and 100 g / m ² or less, and more preferably 12 g / m ² or more and 60 g / m ² or less. Further, the thickness of the intermediate layer is preferably 0.1 mm or more and 5 mm or less, more preferably 0.15 mm or more and 3 mm or less. Further, the intermediate layer preferably has a stiffness, as measured by a cantilever method described later, of 60 mm or more and 160 m or less in the MD direction. In the present invention, by setting the basis weight, thickness, and bristles of the intermediate layer within the above ranges, the absorber is excellent in shape retention during wet and repetitive body fluid absorption.

(Second absorbent core layer)
The laminated absorbent core 21 included in the absorbent body 17 of the present embodiment has a second absorbent core layer 20 on which a fixed amount of a high-absorbent polymer is carried via an adhesive. The layer 20 is sandwiched between the intermediate layer 19 and the second core wrap sheet portion 25, except for the configuration relating to the superabsorbent polymer-free region 28 described below. It is the same as the one absorbent core layer 18. In the present invention, the basis weight of the superabsorbent polymer and the pulp fiber in the second absorbent core layer may be the same as that of the first absorbent core layer, or may be larger than that of the first absorbent core layer. It may be smaller than one absorbent core layer.

(Superabsorbent polymer-free area)
As shown in FIG. 2, in the present embodiment, the second absorbent core layer 20 extends in the longitudinal direction L, extends from one end to the other end, and is formed of a superabsorbent polymer in the thickness direction T. It has two superabsorbent polymer-free regions 28 that are not present. Here, the superabsorbent polymer has a tendency to swell by absorbing water and to be difficult to permeate the liquid due to blocking. In the present embodiment, the second absorbent core layer 20 includes the superabsorbent polymer-free region 28, which is present on the side of the garment, so that it penetrates into the absorbent 17 and The body fluid that stays in the portion near the back sheet 5 is easily absorbed by the absorber 17. In the present invention, the first absorbent core layer may have a superabsorbent polymer-free region, or the second absorbent core layer may be on the skin side. In those cases, that is, even when the superabsorbent polymer-free region is located on the skin side surface side of the intermediate layer, the presence of the superabsorbent polymer-free region allows the body fluid to diffuse in the longitudinal direction. In addition, the diffused body fluid easily penetrates into the absorber, and the penetration of the body fluid from the skin side to the clothing side is promoted.

  In the present invention, the number of the superabsorbent polymer-free regions in at least one of the first absorbent core layer and the second absorbent core layer is such that blocking is performed while maintaining the absorption performance of the absorber. From the viewpoint of effective prevention, the number is preferably one or more and four or less, and more preferably two or three, with respect to the entire width in the width direction of the at least one absorbent core layer. When three or more superabsorbent polymer-free regions exist in the first absorbent core layer or the second absorbent core layer, the superabsorbent polymer-free region is defined as the first absorbent core layer or the second absorbent core. The layers are preferably provided at equal intervals, and the width of the superabsorbent polymer-free region is preferably 5 mm or more and 60 mm or less.

  In the present invention, when the superabsorbent polymer-free region is provided in both the first absorbent core layer and the second absorbent core layer, the superabsorbent polymer-free region in the first absorbent core layer is provided. The number of regions provided may be at least greater than the number of superabsorbent polymers provided in the second absorbent core layer, and may be the same as the number of superabsorbent polymers provided in the second absorbent core layer. The installation site of the superabsorbent polymer-free region in the first absorbent core layer and the installation site of the superabsorbent polymer-free region in the second absorbent core layer may overlap each other in the width direction. May be different from each other.

  In the present invention, when a superabsorbent polymer-free region is present in at least one of the first absorbent core layer and the second absorbent core layer, the width of the at least one absorbent core layer The dimension in the direction shall mean the dimension in the width direction of the region including the superabsorbent polymer-free region.

  In the present embodiment, the intermediate joint portion 30 joins the second core wrap sheet portion 25 and the intermediate layer 19, and the superabsorbent polymer-free region 28 exists in the second absorbent core layer 20. However, the superabsorbent polymer-free region 28 and the intermediate joint 30 overlap in the thickness direction T. In the present invention, when the intermediate joint portion is provided, the first absorbent core layer and the first absorbent core layer that are in contact with the first core wrap sheet portion or the second core wrap sheet portion forming the intermediate joint portion. One of the two absorbent core layers is provided with a superabsorbent polymer-free region, and the intermediate junction overlaps the superabsorbent polymer-free region in the thickness direction. For example, if the first core wrap sheet portion and the intermediate layer join to form an intermediate joint, the first absorbent core layer has a superabsorbent polymer-free region and the second core wrap sheet portion When the intermediate layer and the intermediate layer are joined to form an intermediate joint portion, a superabsorbent polymer-free region exists in the second absorbent core layer. In the present invention, since the intermediate joint overlaps the superabsorbent polymer-free region in the thickness direction, even when the superabsorbent polymer swells, the intermediate joint maintains the joint structure and absorbs. Excellent body shape retention when wet.

<Method for producing absorber>
In producing the absorber of the present invention, basically, it may be produced by a conventional method of producing an absorber.

  First, the hot melt adhesive is applied on the continuous sheet for the lower core wrap sheet while moving the lower continuous sheet for the core wrap sheet in the longitudinal direction L. Next, the superabsorbent polymer is supplied from the superabsorbent polymer supply device along the longitudinal direction L onto both end portions and the central portion in the width direction W of the continuous sheet for the lower core wrap sheet coated with the hot melt adhesive. And spray. Next, the continuous sheet for the intermediate layer 19 having the hot melt adhesive applied to both sides is laminated on the superabsorbent polymer for the lower core wrap sheet. Then, while moving the laminate in the longitudinal direction L, the superabsorbent polymer is supplied from another superabsorbent polymer supply device to both ends in the width direction W of the continuous sheet for the intermediate layer 19 coated with the hot melt adhesive. Spread along the longitudinal direction L over the part and the central part. Then, a continuous sheet for the upper layer core wrap sheet obtained by applying the hot melt adhesive onto the superabsorbent polymer on the lower layer continuous sheet for the core wrap sheet is placed on the high melt polymer side of the hot melt adhesive. And stack. Then, after folding both sides in the width direction W of the continuous sheet for the lower core wrap sheet onto the continuous sheet for the upper core wrap sheet, the laminate is passed through a pair of press rolls and pressed. The absorber 17 is formed by adjusting the thickness of the absorber 17.

  In the present invention, the water-absorbent nonwoven fabric preferably has a high-density portion and a low-density portion, and the high-density portion and the low-density portion are formed by subjecting the nonwoven fabric formed by hydroentanglement to gear processing. Preferably. This gear processing has a plurality of ridges provided in parallel with each other at regular intervals in the roll width direction along the outer peripheral surface, and a concave groove between adjacent ridges. The protruding ridge is formed by inserting and stretching the raw sheet between a shaping apparatus having a pair of upper and lower stretching rolls configured to mesh with the concave grooves of the other stretching roll. . Here, in a state where the portion sandwiched between the top of the protruding ridge and the bottom of the concave groove is fixed, a portion located between two adjacently fixed portions is extended, so that the The part fixed to the top part and the bottom part of the concave groove becomes the high density part, and the part sandwiched between adjacent high density parts becomes the low density part. Normally, when gear processing is performed on a nonwoven fabric having particularly high rigidity, irregularities may remain on the surface of the nonwoven fabric. In the present invention, by adjusting the basis weight of the nonwoven fabric constituting the core wrap sheet, the thickness, the material of the water-absorbing fiber, etc., the rigidity of the core wrap sheet is adjusted, and the core wrap sheet is subjected to gear processing. May be adjusted to be flat.

  When manufacturing the disposable diaper 1 using the absorbent body 17 of the present embodiment, the first surface 34 is disposed on the skin side surface, the second surface 35 is disposed on the clothing side surface, and the first core wrap sheet described above. The part 24 is arranged between the absorbent core 21 and the topsheet 3. However, the absorbent article provided with the absorbent body of the present invention may be configured such that the first surface of the absorbent body is arranged on the clothing side surface and the second surface is arranged on the skin side surface, and the first core wrap sheet is provided. May be arranged between the absorbent core and the topsheet, or may be arranged between the absorbent core and the backsheet.

  Hereinafter, the present invention will be described in detail with reference to examples. It should be noted that the present invention is not limited to the embodiments described below.

[Intermediate layer A]
An air-through nonwoven fabric having a basis weight of 40 g / m ² and a thickness of 0.8 mm (a fineness of 4.4 dtex × fiber length of 51 mm) was obtained from a sheath-core composite fiber of polyethylene (PE) / polypropylene (PP) = 50/50 (sheath / core). Manufactured by Unicharm Kokunon Non-Woven Co., Ltd.) and used as the intermediate layer A. The intermediate layer A was not subjected to so-called processing such as gear processing or embossing, and the intermediate layer A was flat.

[Core Wrap Sheet A ("Core Wrap A")]
A rayon spun lace nonwoven fabric having a basis weight of 43 g / m ² and a thickness of 0.4 mm (rayon 100% by mass, fineness 1.7 dtex × fiber length 40 mm, manufactured by South Pacific Viscose Co., Ltd.) was prepared. A plurality of high-density portions extending in the longitudinal direction and arranged in the width direction by performing gear processing on the raw material, and between the high-density portions adjacent to each other among the plurality of high-density portions. A core wrap sheet A having a low-density portion arranged in was prepared. The core wrap sheet A had regular irregularities, but the height difference t between the concave portion and the convex portion on one surface of the core wrap sheet A was equal to the thickness d of the core wrap sheet in the thickness direction T. It was less than three times. At both ends in the width direction of the core wrap sheet A, high-density portions were arranged. Except for both ends in the width direction, the width of the high-density part was about 0.2 mm, and the width of the low-density part was about 0.55 mm.

[Core Wrap Sheet B ("Core Wrap B")]
A rayon spun lace nonwoven fabric having a basis weight of 43 g / m ² and a thickness of 0.4 mm (rayon 100% by mass, fineness 1.7 dtex × fiber length 40 mm, manufactured by South Pacific Viscose Co., Ltd.) was prepared, and gear processing was performed. The core wrap sheet B was not applied.

[Core Wrap Sheet C ("Core Wrap C")]
A spun-lace nonwoven fabric having a basis weight of 45 g / m ² and a thickness of 0.4 mm (an upper layer (a basis weight of 11 g / m ² ) made of 100% rayon fiber of 1.7 dtex × 40 mm manufactured by South Pacific Viscose Co., Ltd.) Middle layer (basis weight 23 g / m ² ) of 100% pulp fiber manufactured by Paper Corporation and lower layer (basis weight 11 g / m ² ) of 1.7 dtex × 40 mm rayon fiber 100% manufactured by South Pacific Viscose A spun lace nonwoven fabric comprising: a plurality of high-density portions, which are subjected to gear processing on the raw material of the nonwoven fabric, extended in the longitudinal direction, and arranged in the width direction; A core wrap sheet C having a low-density part disposed between adjacent high-density parts among the high-density parts was prepared. The core wrap sheet C had regular irregularities, but the height difference t between the concave portion and the convex portion on one surface of the core wrap sheet C was smaller than the thickness d of the core wrap sheet in the thickness direction T. It was less than three times. At both ends in the width direction of the core wrap sheet C, high-density portions were arranged. Except for both ends in the width direction, the width of the high-density part was about 0.2 mm, and the width of the low-density part was about 0.55 mm.

[Core Wrap Sheet D ("Core Wrap D")]
As the core wrap sheet D, a hydrophilic non-treated SMS nonwoven fabric (manufactured by CNC International) having a basis weight of 10 g / m ² and a thickness of 0.2 mm was used.

[Core Wrap Sheet E ("Core Wrap E")]
As the core wrap sheet E, an air-laid nonwoven fabric having a basis weight of 60 g / m ² and a thickness of 1 mm (trade name: Kinocross, manufactured by Oji Kinocross Co., Ltd.) was used.

  The above core wrap sheet and intermediate layer were evaluated by the following test methods. Table 1 shows the results.

[Evaluation of nonwoven fabric]
In this example, the characteristics of each nonwoven fabric were evaluated by performing the following evaluation tests on the intermediate layers and the core wrap sheets A to E produced as nonwoven fabrics. In addition, if a nonwoven fabric is sampled from the absorber provided in the absorbent article and their properties are evaluated, a cold spray at −40 ° C. is sprayed on the absorber to reduce the bonding strength of the hot melt adhesive. Alternatively, the hot melt adhesive may be dissolved using an organic solvent, each nonwoven fabric may be peeled from the absorber, and cut into dimensions necessary for each evaluation test.

(Tensile strength)
The tensile strength at the time of drying (Dry) and at the time of wet (Wet) is obtained by cutting the manufactured core wrap sheet so that the longitudinal direction is the CD direction and the sample width is 25 mm × length 75 mm. The sample was dried for 24 hours under an atmosphere of 20 ° C. and a relative humidity of 65% for a dry sample. % Of distilled water in the form of a mist and allowed to stand for 1 minute, using “Autograph AG-50NXPlus HS” (manufactured by Shimadzu System Solutions Co., Ltd.) under the conditions of 20 ° C. and 65% relative humidity. , The chucking distance 50 mm, and the tensile force (N) measured at a tensile speed of 50 mm / min. For these tensile strengths, the average value of five measurements was adopted. As for the tensile strength, the tensile strength when the nonwoven fabric is elongated by 30% (“30% tensile strength”) and the maximum tensile strength are measured, and at the same time, the elongation at which the maximum tensile strength is exhibited is measured as the maximum elongation. The displacement and the tensile strength at a point of 0% elongation at which the elongation becomes 0% with respect to the maximum elongation and at a point of 50% elongation at which the elongation becomes 50% with respect to the maximum elongation. The “first half elastic modulus” was calculated from each difference, and the “second half elastic modulus” was calculated from the difference between the displacement amount and the tensile strength at the point of 50% elongation and the point of maximum elongation.

(Rigidity)
For the softness, a wooden cantilever testing machine with a horizontal top surface and a 45 ° slope, coated with polytetrafluoroethylene (PTFE), is used with a bamboo ruler with a minimum scale of 1 mm and a length of 30 cm. The measurement was performed using a sample piece obtained by cutting the nonwoven fabric so that the dimension in the MD direction was 200 mm and the dimension in the CD direction was 25 mm (n = 5). More specifically, with the surface of the sample piece facing up, the sample piece was placed such that the short side of the sample piece was parallel to the edge facing the slope on the top surface of the bending tester. While holding the sample piece lightly with a bamboo ruler, slide the sample piece in the direction of the slope, measure the travel distance (mm) when the sample piece is bent by its own weight, and perform the same measurement with the back side up. And by taking the average of the front and back.

(Basis weight)
For the measurement of the basis weight, as a nonwoven fabric sample, ten test pieces cut into a size of 100 mm × 100 mm were prepared, and their masses were measured using a direct reading balance (for example, an electronic balance HF manufactured by Kensei Kogyo Co., Ltd.). -300), and the weight per unit area of the nonwoven fabric (g / m ² ) calculated based on the average value of the weights of the ten test pieces was defined as the basis weight of the nonwoven fabric.

(thickness)
The thickness of the nonwoven fabric was measured with a nonwoven fabric thickness gauge “UF-60A manufactured by Daiei Scientific Instruments” (measuring element φ44 mm, measuring load: 0.49 N). The average value of 10 test pieces was defined as the thickness.

Table 1 shows the above results.

[Examination of nonwoven fabric characteristics]
(About core wrap sheet)
As shown in Table 1, the core wrap sheet D has an excessively high 30% tensile strength, and thus has a low elongation as a nonwoven fabric, and may inhibit swelling of the superabsorbent polymer when used as a core wrap sheet. Was concerned. Regarding the core wrap sheet E, although the tensile strength was low, the core wrap sheet E was broken at a certain strength or more, and there was a concern that the superabsorbent polymer could not be sufficiently retained. On the other hand, the core wrap sheets A to C have a low 30% tensile strength and a large elongation, but have a higher swelling than the first half elastic modulus which is assumed to correspond to the initial swelling when used as a core wrap sheet. Since the latter half elastic modulus, which is assumed to correspond to the latter period, is high, it is difficult to inhibit the swelling of the superabsorbent polymer, and it is predicted that the absorption performance is excellent, but it is difficult to lose its shape and is excellent in wet shape retention. It was predicted.

(About the middle class)
As shown in Table 1, the intermediate layer A had substantially the same 30% tensile strength, maximum tensile strength, maximum elongation, first-half elastic modulus, and second-half elastic modulus when wet and when dry. From these results, it was predicted that the absorber provided with the intermediate layer A was excellent in shape retention during wet and repetitive absorption.

[Preparation of absorber]
Absorbers of Examples 1 to 3 and Comparative Examples 1 and 2 were produced from the samples of the intermediate layer and the core wrap sheet produced as described above in combinations shown in Table 2 as described below.

(1) A nonwoven fabric for a lower layer core wrap sheet is cut into a width of 140 mm and a length of 400 mm, and a hot melt adhesive is applied to the entire upper surface thereof at a basis weight of 7 g / m ² using a spiral coater.
(2) A high-absorbency polymer-free region having a width of 10 mm is provided at a distance of 30 mm within a range of a width of 100 mm at a central portion in the width direction on the upper surface of the lower nonwoven fabric for a core wrap sheet, while providing high absorption. Water-soluble polymer (Aqua Keep, manufactured by Sumitomo Seika Co., Ltd.) is evenly applied at a basis weight of 155 g / m ² .
(3) An air-through nonwoven fabric (for the intermediate layer) having a basis weight of 40 g / m ² was cut into a width of 100 mm × length of 400 mm, and a hot melt adhesive was applied on both sides and the entire surface thereof with a basis weight of 7 g / m ² using a spiral coater. Apply with.
(4) The air-through nonwoven fabric of the above (3) is placed on the lower nonwoven fabric for the core wrap sheet of the above (2). A highly absorbent polymer (Aqua Keep, manufactured by Sumitomo Seika Co., Ltd.) is uniformly sprayed on the upper surface of the air-through nonwoven fabric at a basis weight of 225 g / m ^{2 in} a range of a width of 100 mm at a central portion in a width direction.
(5) The upper nonwoven fabric for the core wrap sheet is cut into a width of 100 mm and a length of 400 mm, and a hot melt adhesive is applied on the entire surface of one surface thereof at a basis weight of 7 g / m ² using a spiral coater.
(6) The nonwoven fabric for the core wrap sheet of the upper layer is placed on the upper surface of the air-through nonwoven fabric of (4) above, with the surface coated with the hot melt adhesive facing downward. Then, the 20 mm portions on both sides in the width direction of the lower nonwoven fabric for the core wrap sheet are folded inward and sealed. Thereby, an absorber is formed.
(7) Then, the absorber is pressed by a press machine whose press pressure is adjusted so that the thickness of the absorber becomes 2.5 mm. Thereby, an absorber having a uniform thickness is manufactured.

  The obtained absorbent was evaluated for shape retention during wet, absorption performance, and repeated absorption of body fluid. As a result, the absorbers of Examples 1 to 3 had better absorption performance than the absorbers of Comparative Examples 1 and 2. Further, the absorbers of Examples 1 to 3 had better shape retention during wet and absorbability of body fluid repetition as compared with the absorbers of Comparative Examples 1 and 2.

L Longitudinal direction W Width direction C Width direction middle part E Width direction both ends T Thickness direction Tc Thickness direction center plane 1 Disposable diaper 3 Top sheet 5 Back sheet 7 Leak prevention wall 9 Elastic member 15 Tape fastener 17 Absorber 18 1 absorbent core layer 19 intermediate layer 20 second absorbent core layer 21 laminated absorbent core 22 central sheet part 23 outer sheet part 24 first core wrap sheet part 25 second core wrap sheet part 26 core wrap sheet 27 overlapping part 28 High Absorbent Polymer Absent Area 29 Joint 30 Intermediate Joint 31 Edge 32 High Density 33 Low Density 34 First Surface 35 Second Surface

Claims (14)

A first absorbent core layer, an intermediate layer, having a first surface, a second surface, and a longitudinal direction, a width direction, and a thickness direction orthogonal to each other, and from the first surface to the second surface; And a second absorbent core layer, an absorbent article for an absorbent article having a laminated absorbent core laminated in this order, and a core wrap sheet,
The first absorbent core layer and the second absorbent core layer include a super absorbent polymer,
The core wrap sheet is a first core wrap sheet portion located on a first surface side of a thickness center surface of the absorber, and is located on a second surface side of a thickness center surface of the absorber. A second core wrap sheet portion;
The first core wrap sheet portion has a water-absorbent nonwoven fabric made of water-absorbent fibers including a water-absorbent fiber having a fiber length of 25 mm or more entangled with each other,
The absorber has a joining portion where the intermediate layer and the first core wrap sheet portion are joined,
The elongation in the wet tensile test of the water-absorbent nonwoven fabric is greater than the elongation in the dry tensile test, the tensile strength in the wet tensile test is lower than the tensile strength in the dry tensile test,
The intermediate layer is a heat-sealed nonwoven fabric obtained by fusing a plurality of thermoplastic synthetic fibers,
An absorber, wherein the heat-fused nonwoven fabric has an elongation and a tensile strength in a wet tensile test of 90% or more and 110% or less of a dry tensile test, respectively.   The absorbent body according to claim 1, wherein the water-absorbing fiber having a fiber length of 25 mm or more is a regenerated cellulose fiber.   3. The absorbent body according to claim 1, wherein the water-absorbent nonwoven fabric is a spunlaced nonwoven fabric.   The absorber according to any one of claims 1 to 3, wherein the heat-sealed nonwoven fabric is an air-through nonwoven fabric. The water-absorbent nonwoven fabric,
A plurality of high-density portions extending along the longitudinal direction and arranged side by side in the width direction;
5. A plurality of low-density portions extending along the longitudinal direction and having a plurality of low-density portions disposed between adjacent high-density portions of the plurality of high-density portions. 6. The absorbent body according to item 1. The absorber is divided into width-direction both ends arranged at both ends in the width direction, and a width-direction middle portion sandwiched between the width-direction both ends,
The said absorber is equipped with the intermediate joining part in which the said intermediate layer and at least one of the said 1st core wrap sheet part and the 2nd core wrap sheet part are joined in the said width direction intermediate part. The absorber according to any one of claims 1 to 5. One of the first absorbent core layer and the second absorbent core layer, which is in contact with the first core wrap sheet portion or the second core wrap sheet portion constituting the intermediate joint, Having a superabsorbent polymer-free region where the superabsorbent polymer does not exist in the thickness direction,
The absorber according to claim 6, wherein the intermediate joint overlaps the superabsorbent polymer-free region in the thickness direction.   The absorber according to claim 7, wherein the superabsorbent polymer-free region extends in the longitudinal direction.   The absorbent body according to any one of claims 1 to 8, wherein the first surface is a skin side surface, and the second surface is a clothing side surface. The first core wrap sheet portion includes a central sheet portion disposed closer to the center in the width direction, and a pair of outer sheet portions disposed on both outer sides in the width direction.
The first core wrap sheet portion is a pair of overlapping portions in which the central sheet portion overlaps each of the pair of outer sheet portions in the thickness direction, and extends in the longitudinal direction. The absorbent body according to claim 9, comprising:   In each of the pair of superimposed portions, each of the pair of outer sheet portions is disposed closer to the first surface than the central sheet portion, and the central sheet of each of the pair of outer sheet portions is provided. The absorber according to claim 10, wherein an edge on a partial side is separated from the central sheet portion. The absorber is divided into width-direction both ends arranged at both ends in the width direction, and a width-direction middle portion sandwiched between the width-direction both ends,
The absorber according to any one of claims 1 to 11, wherein the absorber includes the joints at both ends in the width direction.   The absorber according to claim 12, wherein the width dimension of the first absorbent core layer is smaller than the width dimension of the second absorbent core layer. The water-absorbent nonwoven fabric has an elongation of 30% or more in each of the wet tensile test and the dry tensile test, and the tensile strength at 30% elongation in the wet tensile test is 30% in the dry tensile test. 25% or less of the tensile strength at elongation,
The absorber according to any one of claims 1 to 13.

Images