JP3231637U - Absorbent of absorbent articles - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an absorber containing a highly water-absorbent polymer, which has a high absorption rate and can suppress a feeling of leakage immediately after urination and lateral leakage. An absorber 3 for an absorbent article includes a first base material 21 containing an air-laid pulp non-woven fabric arranged on the skin side and a spunlace non-woven fabric arranged on the non-skin side and having hydrophilic fibers. The two base materials 26 and the water absorbing materials 23 and 28 contained between the first base material and the second base material and containing a highly water-absorbent polymer as a main component are provided. The water retention amount indicating the water retention of the air-laid pulp non-woven fabric and the water retention of the spunlace non-woven fabric is 300 to 800 g / m2. The Krem water absorption height showing the liquid diffusivity of the air-laid pulp non-woven fabric is 0 to 100 mm, and the Krem water absorption height showing the liquid diffusivity of the spunlace non-woven fabric is 100 mm or more. [Selection diagram] Fig. 3

Description

The present invention relates to an absorber for an absorbent article.

Absorbents for absorbent articles are known to use substantially only a super absorbent polymer (SAP) as a water-absorbing material that absorbs liquid excrement (eg, urine). For example, in Patent Document 1 (Patent No. 6033236), a water-absorbing layer having a structure in which an absorbent layer containing a predetermined water-absorbent resin (highly water-absorbent polymer) and an adhesive is sandwiched by a non-woven fabric from above and below is provided. The seat structure is disclosed. In this water-absorbent sheet structure, a water-permeable non-woven fabric having excellent water permeability is used as the upper non-woven fabric, and a water-retaining non-woven fabric having excellent water retention is used as the lower non-woven fabric. According to Patent Document 1, this water-absorbing sheet structure is thin and can sufficiently exhibit absorption capacity such as fast liquid permeability, small liquid return amount, and small liquid leakage amount.

Japanese Patent No. 60333236

In the water-absorbing sheet structure described in Patent Document 1, that is, the absorbent body, the water-absorbing material is substantially composed of a highly water-absorbent polymer without containing pulp fibers. Due to the thin thickness of this absorber, the volume of the absorber that holds the liquid is smaller than that of the absorber composed of pulp fibers and a highly water-absorbent polymer. Further, the absorption rate of this absorber is slower than that of the absorber composed of the pulp fiber and the highly water-absorbent polymer due to the slow absorption rate of the highly water-absorbent polymer. Therefore, in this absorber, liquid excrement (eg, urine) first reaches the lower non-woven fabric via the water-permeable upper non-woven fabric, and the lower non-woven fabric retains water while retaining high water absorption on the lower layer side. It is considered that it is absorbed from the polymer over a certain period of time.
However, when a wearer wearing an absorbent article to which such an absorber is applied excretes excrement, for example, urine, if the amount of urine is large, the lower layer is passed through the water-permeable upper non-woven fabric. There may be a situation in which too much urine should reach the non-woven fabric, the water retention of the urine by the lower non-woven fabric and the absorption by the highly absorbent polymer are not in time, and the urine becomes congested. In that case, urine remains on the surface sheet on the upper non-woven fabric for a while, and immediately after urination, the wearer feels that the urine is wet on the surface sheet, and the urine is transmitted through the surface sheet. Lateral leakage that leaks to the outside may occur.

Therefore, an object of the present invention is an absorbent article in which an absorber using a highly water-absorbent polymer as a main component of a water-absorbing material has a high absorption rate and can suppress a feeling of leakage immediately after urination and lateral leakage. To provide an absorber for use.

The absorber for the absorbent article of the present invention is as follows. (1) An absorbent body for an absorbent article, the first base material containing an air-laid pulp non-woven fabric arranged on the skin side, and a second base material containing a spunlaced non-woven fabric arranged on the non-skin side and having hydrophilic fibers. A water-retaining material of the air-laid pulp non-woven fabric and a spunlaced non-woven fabric, which comprises a base material and a water-absorbing material contained between the first base material and the second base material and containing a highly water-absorbent polymer as a main component. The water retention amount indicating the water retention is 300 to 800 g / m ² , and the Krem water absorption height indicating the liquid diffusivity of the air-laid pulp non-woven fabric is 0 to 100 mm, and the liquid diffusibility of the spunlace non-woven fabric is exhibited. An absorber having a pulp water absorption height of 100 mm or more.

In this absorber, in the first base material on the skin side and the second base material on the non-skin side that function as core wraps, the water retention of the air-laid pulp non-woven fabric in the first base material is the water retention of the spunlace non-woven fabric in the second base material. The amount of water retained, which indicates water retention, is as high as ^{300 to 800 g / m 2.} Further, the liquid diffusivity of the air-laid pulp non-woven fabric of this absorber is lower than the liquid diffusivity of the spunlaced non-woven fabric, and the Krem water absorption height showing the liquid diffusivity is 0 to 100 mm for the air-laid pulp non-woven fabric, and the spunlaced non-woven fabric Then it is 100 or more.
Therefore, when liquid excrement (eg, urine) is excreted in the absorbent article, the first base material on the skin side quickly absorbs the excrement due to its high water retention and low liquid diffusivity. It can be temporarily stored in a small area without diffusion (spot absorption). Further, the second base material on the non-skin side absorbs excrement arriving through the first base material due to its high water retention and high liquid diffusivity, and diffuses it over a wide range in the plane direction. It can be absorbed with a highly water-absorbent polymer. Therefore, even if there is a large amount of excrement that reaches the second base material via the first base material, the water retention of the excrement on the second base material and the absorption by the highly water-absorbent polymer are not in time, and urine is congested. It is possible to suppress the situation where it ends up. In other words, the first substrate temporarily stores the excrement (and gradually releases the excrement) to allow time for the second substrate to retain water, diffuse and subsequently absorb the highly water-absorbent polymer. You can earn. Therefore, it is possible to prevent the excrement from remaining on the surface sheet and causing a feeling of leakage and the occurrence of lateral leakage. In particular, by storing the excrement in a narrow area, it becomes difficult for the wearer to feel the presence of the excrement as compared with the case where the excrement is stored in a wide area (when the first base material has high liquid diffusivity). The feeling of leakage can be made more difficult to remember.
However, the water-absorbing material containing the high-water-absorbing polymer as a main component is usually composed of the high-water-absorbing polymer, pulp fiber and other components, but the ratio of the high-water-absorbing polymer in the water-absorbing material is 70 to 70 to It means that it is 100% by mass.

The absorber of the present invention comprises (2) the above-mentioned (1), wherein the air-laid pulp non-woven fabric contains a plurality of hydrophilic fibers containing a plurality of pulp fibers and a hydrophilic binder covering the plurality of hydrophilic fibers. The absorber described may be used.
In this absorber, the air-laid pulp non-woven fabric of the first base material contains hydrophilic fibers containing pulp fibers and a hydrophilic binder. Therefore, the fiber itself can retain liquid excrement such as urine. Further, since the fibers are joined by a hydrophilic binder at the mating contact point, it is easy to maintain the skeleton structure (voids between the fibers) by the fibers, and it is possible to easily hold the liquid in the gaps. These allow the first substrate to more reliably and quickly absorb its excrement and temporarily store it.

In the absorber of the present invention, (3) the fiber lengths of the plurality of fibers constituting the air-laid pulp nonwoven fabric are shorter than the fiber lengths of the plurality of fibers constituting the spunlaced nonwoven fabric, according to the above (1) or (2). The absorber described in 1.
In this absorber, the fiber length of the fibers of the air-laid pulp non-woven fabric is shorter than the fiber length of the fibers of the spunlace non-woven fabric. Therefore, the liquid diffusivity of liquid excrement such as urine in the first base material can be relatively lowered. Thereby, the first substrate can be more reliably temporarily stored in a narrow area without causing much diffusion of excrement.

In the absorber of the present invention, (4) each of the plurality of fibers constituting the spunlace non-woven fabric is a plurality of convex portions extending along the axis of the fibers and a plurality of convex portions located between adjacent convex portions. The absorber according to any one of (1) to (3) above, which has a recess on the surface.
In this absorber, on the surface of fibers (eg, rayon fibers) constituting the spunlace non-woven fabric, a plurality of convex portions extending along the axis of the fibers and a plurality of concave portions located between adjacent convex portions are formed. have. Therefore, the second base material can easily diffuse liquid excrement such as urine along the convex portion and the concave portion thereof. That is, the liquid diffusibility of the liquid excrement in the second base material can be relatively increased. As a result, the second base material can more reliably retain water and diffuse the excrement in the plane direction.

The absorbent body of the present invention is: (5) The absorbent body is an intermediate formed of a first absorbent layer, a second absorbent layer, and a non-woven fabric located between the first absorbent layer and the second absorbent layer. The first absorbing layer is further provided with a layer, and is arranged on the intermediate layer side of the first base material and the first base material, contains a highly water-absorbent polymer, and is a part of the water-absorbing material. A first adhesive that is located on at least one of a first water-absorbing material, the surface of the first base material on the intermediate layer side, and the surface of the intermediate layer on the first base material side, and fixes the first water-absorbing material. The second absorbent layer contains the agent, is arranged on the intermediate layer side of the second base material and the second base material, contains a highly water-absorbent polymer, and is a part of the water-absorbing material. A second adhesive that is located on at least one of the second water-absorbent material, the surface of the second base material on the intermediate layer side, and the surface of the intermediate layer on the second base material side, and fixes the second water-absorbent material. The absorber according to any one of (1) to (4) above, which comprises and.
In the present absorber, the absorber is divided into a first absorption layer and a second absorption layer with an intermediate layer interposed therebetween. Therefore, the excrement absorbed by the first base material on the skin side reaches the second base material, retains water, and diffuses, and at the same time, a part of the excrement is retained in the non-woven fabric of the intermediate layer in the middle to some extent. Can be diffused. That is, the non-woven fabric of the intermediate layer located on the non-skin side of the first absorption layer can exhibit the same function as the second base material located on the non-skin side of the second absorption layer. As a result, it is possible to further suppress the situation where too much excrement reaches the second base material on the non-skin side via the first base material, and the excrement remains on the surface sheet, causing a feeling of leakage and laterality. Leakage can be further suppressed. At the same time, the first water absorbing material of the first absorbing layer on the skin side can be used at an early stage, whereby the water absorbing material can be efficiently used in the thickness direction.

The absorber of the present invention may be (6) the absorbent according to (5) above, wherein the non-woven fabric of the intermediate layer contains pulp fibers.
In this absorber, the non-woven fabric in the intermediate layer contains pulp fibers. Therefore, the excrement absorbed by the first base material on the skin side reaches the second base material, retains water, and diffuses, and a part of the excrement is more reliably put on the non-woven fabric of the intermediate layer in the middle. Can retain and diffuse water.

In the absorber of the present invention, (7) the absorber is located in a region inside the both ends in the width direction of the absorber in a plan view, and the first base material and the second base material are formed from each other. It has a bonding region that is bonded to each other with an adhesive, and the bonding region has a width of the absorber with respect to a longitudinal center line that passes through the center in the width direction and extends parallel to the longitudinal direction of the absorber. Includes a pair of longitudinal joint regions located on both sides of the direction, passing through the central portion of the longitudinal direction, and having a slit-like shape extending in the longitudinal direction, and between the pair of longitudinal joint regions in the width direction. The item according to any one of (1) to (6) above, wherein the basis weight of the water absorbing material in the region is larger than the basis weight of the water absorbing material in each outer region of the pair of longitudinal joint regions. Absorber, may be.
In the present absorber, the basis weight of the water absorbing material in the region between the pair of longitudinal joining regions is larger than the basis weight of the water absorbing material in each outer region of the pair of longitudinal joining regions. That is, in the central region and the regions at both ends of the absorber, which are separated by a pair of longitudinal joint regions, the basis weight of the water absorbing material in the central region is relatively large. As a result, while ensuring the absorption capacity in the central region where the amount of excrement of liquid excrement is large, the diffusion in the width direction of the liquid excrement is restricted by the pair of longitudinal joint regions, and the diffusion in the longitudinal direction is performed. Can be induced and the entire absorber can be used efficiently. In addition, the regions at both ends can absorb the liquid excrement leaked in the width direction and suppress the occurrence of lateral leakage.

The absorber for the absorbent article of the present invention can also be expressed as follows. (8) An absorbent body for an absorbent article, the first base material containing an air-laid pulp non-woven fabric arranged on the skin side, and a second base material containing a spunlace non-woven fabric arranged on the non-skin side and having hydrophilic fibers. An absorber comprising a base material and a water-absorbing material contained between the first base material and the second base material and containing a highly water-absorbent polymer as a main component.

In this absorber, in the first base material on the skin side and the second base material on the non-skin side that function as core wraps, the water retention of the air-laid pulp non-woven fabric used for the first base material is relatively high among the non-woven fabrics. The water retention of the spunlace non-woven fabric used for the second base material is also relatively high among the non-woven fabrics. Therefore, as with the water retention of the spunlace non-woven fabric, the water retention of the air-laid pulp non-woven fabric of this absorber is relatively high. Further, the liquid diffusibility of the air-laid pulp non-woven fabric is relatively low in the non-woven fabric, and the liquid diffusibility of the spunlace non-woven fabric is relatively high in the non-woven fabric. Therefore, the liquid diffusibility of the air-laid pulp non-woven fabric is lower than that of the spunlace non-woven fabric. For example, the water retention amount indicating the water retention of the air-laid pulp non-woven fabric and the spunlace non-woven fabric is 300 to 800 g / m2, the Krem water absorption height indicating the liquid diffusivity of the air-laid non-woven fabric is 0 to 100 mm, and the liquid of the spunlace non-woven fabric. The diffusible Krem water absorption height is 100 mm or more.
Therefore, when liquid excrement (eg, urine) is excreted in the absorbent article, the first base material on the skin side quickly absorbs the excrement due to its high water retention and low liquid diffusivity. It can be temporarily stored in a small area without diffusion (spot absorption). Further, the second base material on the non-skin side absorbs excrement arriving through the first base material due to its high water retention and high liquid diffusivity, and diffuses it over a wide range in the plane direction. It can be absorbed with a highly water-absorbent polymer. Therefore, even if there is a large amount of excrement that reaches the second base material via the first base material, the water retention of the excrement on the second base material and the absorption by the highly water-absorbent polymer are not in time, and urine is congested. It is possible to suppress the situation where it ends up. In other words, the first substrate temporarily stores the excrement (and gradually releases the excrement) to allow time for the second substrate to retain water, diffuse and subsequently absorb the highly water-absorbent polymer. You can earn. Therefore, it is possible to prevent the excrement from remaining on the surface sheet and causing a feeling of leakage and the occurrence of lateral leakage. In particular, by storing the excrement in a narrow area, it becomes difficult for the wearer to feel the presence of the excrement as compared with the case where the excrement is stored in a wide area (when the first base material has high liquid diffusivity). The feeling of leakage can be made more difficult to remember.
However, the water-absorbing material containing the high-water-absorbing polymer as a main component is usually composed of the high-water-absorbing polymer, pulp fiber and other components, but the ratio of the high-water-absorbing polymer in the water-absorbing material is 70 to 70 to It means that it is 100% by mass.

In the absorber of the present invention, (9) the water retention of the air-laid pulp non-woven fabric is equivalent to the water retention of the spunlace non-woven fabric, and the diffusivity of the air-laid pulp non-woven fabric is lower than the diffusivity of the spunlace non-woven fabric. It may be the absorber according to (8) above.
In this absorber, the water retention of the air-laid pulp non-woven fabric and the water-retaining property of the spunlace non-woven fabric are equivalent, and the diffusivity of the air-laid pulp non-woven fabric is lower than that of the spunlace non-woven fabric. Therefore, the water retention of the first base material can be increased more reliably, and the diffusivity of the first base material can be lowered more reliably. Therefore, when the excrement is absorbed, the excrement is made into a narrower region. Therefore, it can be reliably temporarily stored. Here, the equivalent water retention of the two non-woven fabrics means that, for example, in the value of the water retention amount indicating water retention, at least one value falls within the range of ± 40% of the other value. The diffusivity of the air-laid pulp non-woven fabric is preferably 1/2 or less of the diffusivity of the spunlace non-woven fabric.

The absorber of the present invention includes (10) the above-mentioned (8) or the above-mentioned (8) or the above-mentioned (8) or the above-mentioned (8) or The absorber according to (9) may be used.
In this absorber, the air-laid pulp non-woven fabric of the first base material contains hydrophilic fibers containing pulp fibers and a hydrophilic binder. Therefore, the fiber itself can retain liquid excrement such as urine. Further, since the fibers are joined by a hydrophilic binder at the mating contact point, it is easy to maintain the skeleton structure (voids between the fibers) by the fibers, and it is possible to easily hold the liquid in the gaps. These allow the first substrate to more reliably and quickly absorb its excrement and temporarily store it.

In the absorber of the present invention, (11) the fiber lengths of the plurality of fibers constituting the air-laid pulp nonwoven fabric are shorter than the fiber lengths of the plurality of fibers constituting the spunlaced nonwoven fabric, according to the above (8) to (10). The absorber according to any one of the above items may be used.
In this absorber, the fiber length of the fibers of the air-laid pulp non-woven fabric is shorter than the fiber length of the fibers of the spunlace non-woven fabric. Therefore, the liquid diffusivity of liquid excrement such as urine in the first base material can be relatively lowered. Thereby, the first substrate can be more reliably temporarily stored in a narrow area without causing much diffusion of excrement.

In the absorber of the present invention, (12) each of the plurality of fibers constituting the spunlace non-woven fabric is a plurality of convex portions extending along the axis of the fibers and a plurality of convex portions located between adjacent convex portions. The absorber according to any one of (8) to (11) above, which has a recess on the surface.
In this absorber, on the surface of fibers (eg, rayon fibers) constituting the spunlace non-woven fabric, a plurality of convex portions extending along the axis of the fibers and a plurality of concave portions located between adjacent convex portions are formed. have. Therefore, the second base material can easily diffuse liquid excrement such as urine along the convex portion and the concave portion thereof. That is, the liquid diffusibility of the liquid excrement in the second base material can be relatively increased. As a result, the second base material can more reliably retain water and diffuse the excrement in the plane direction.

The absorbent body of the present invention is: (13) The absorbent body is an intermediate formed of a first absorbent layer, a second absorbent layer, and a non-woven fabric located between the first absorbent layer and the second absorbent layer. The first absorbing layer is further provided with a layer, and is arranged on the intermediate layer side of the first base material and the first base material, contains a highly water-absorbent polymer, and is a part of the water-absorbing material. A first adhesive that is located on at least one of a first water-absorbing material, the surface of the first base material on the intermediate layer side, and the surface of the intermediate layer on the first base material side, and fixes the first water-absorbing material. The second absorbent layer contains the agent, is arranged on the intermediate layer side of the second base material and the second base material, contains a highly water-absorbent polymer, and is a part of the water-absorbing material. A second adhesive that is located on at least one of the second water-absorbent material, the surface of the second base material on the intermediate layer side, and the surface of the intermediate layer on the second base material side, and fixes the second water-absorbent material. The absorber according to any one of (8) to (12) above, which comprises.
In the present absorber, the absorber is divided into a first absorption layer and a second absorption layer with an intermediate layer interposed therebetween. Therefore, the excrement absorbed by the first base material on the skin side reaches the second base material, retains water, and diffuses, and at the same time, a part of the excrement is retained in the non-woven fabric of the intermediate layer in the middle to some extent. Can be diffused. That is, the non-woven fabric of the intermediate layer located on the non-skin side of the first absorption layer can exhibit the same function as the second base material located on the non-skin side of the second absorption layer. As a result, it is possible to further suppress the situation where too much excrement reaches the second base material on the non-skin side via the first base material, and the excrement remains on the surface sheet, causing a feeling of leakage and laterality. Leakage can be further suppressed. At the same time, the first water absorbing material of the first absorbing layer on the skin side can be used at an early stage, whereby the water absorbing material can be efficiently used in the thickness direction.

The absorber of the present invention may be (14) the absorber according to (13), wherein the non-woven fabric of the intermediate layer contains pulp fibers.
In this absorber, the non-woven fabric in the intermediate layer contains pulp fibers. Therefore, the excrement absorbed by the first base material on the skin side reaches the second base material, retains water, and diffuses, and a part of the excrement is more reliably put on the non-woven fabric of the intermediate layer in the middle. Can retain and diffuse water.

In the absorber of the present invention, (15) the absorber is located in a region inside the both ends in the width direction of the absorber in a plan view, and the first base material and the second base material are formed from each other. It has a bonding region that is bonded to each other with an adhesive, and the bonding region has a width of the absorber with respect to a longitudinal center line that passes through the center in the width direction and extends parallel to the longitudinal direction of the absorber. Includes a pair of longitudinal joint regions located on both sides of the direction, passing through the central portion of the longitudinal direction, and having a slit-like shape extending in the longitudinal direction, and between the pair of longitudinal joint regions in the width direction. The item according to any one of (8) to (14) above, wherein the basis weight of the water absorbing material in the region is larger than the basis weight of the water absorbing material in each outer region of the pair of longitudinal joint regions. Absorber, may be.
In the present absorber, the basis weight of the water absorbing material in the region between the pair of longitudinal joining regions is larger than the basis weight of the water absorbing material in each outer region of the pair of longitudinal joining regions. That is, in the central region and the regions at both ends of the absorber, which are separated by a pair of longitudinal joint regions, the basis weight of the water absorbing material in the central region is relatively large. As a result, while ensuring the absorption capacity in the central region where the amount of excrement of liquid excrement is large, the diffusion in the width direction of the liquid excrement is restricted by the pair of longitudinal joint regions, and the diffusion in the longitudinal direction is performed. Can be induced and the entire absorber can be used efficiently. In addition, the regions at both ends can absorb the liquid excrement leaked in the width direction and suppress the occurrence of lateral leakage.

According to the present invention, in an absorbent body using a highly water-absorbent polymer as a main component of a water-absorbing material, it is used for an absorbent article having a high absorption rate and capable of suppressing a feeling of leakage or lateral leakage immediately after urination. Absorbents can be provided.

It is a top view which shows the structural example of the absorbent article which concerns on embodiment. It is a top view which shows the structural example of the absorber which concerns on embodiment. It is sectional drawing which follows the line III-III of FIG. It is a side view and the front view which shows an example of a test apparatus schematically. It is a side view which shows an example of another test apparatus schematically. It is a partial plan view which shows an example of another test apparatus schematically.

Hereinafter, the absorbent body for the absorbent article according to the embodiment will be described by taking the absorbent body for the disposable diaper 1 as an example. In this case, the excrement to be absorbed by the disposable diaper 1 is urine. However, the types and uses of the absorbent articles are not limited to this example, and other absorbent articles may be used as long as they do not deviate from the scope of the present invention. Such absorbent articles include, for example, light incontinence pads, panty liners, sanitary napkins.

FIG. 1 is a plan view showing a configuration example of the disposable diaper 1 according to the embodiment. However, FIG. 1 shows a plan view of the disposable diaper 1 in the unfolded state. The disposable diaper 1 has a longitudinal direction L, a width direction W, and a thickness direction T orthogonal to each other, passes through the center of the width direction W and extends in the longitudinal direction L, and passes through the center of the longitudinal direction L and the center of the longitudinal direction L. It has a width direction center line CW extending in the width direction W. The directions toward and away from the center line CL in the longitudinal direction are the inner and outer directions of the width direction W, respectively. The directions toward and away from the center line CW in the width direction are the inner and outer directions of the longitudinal direction L, respectively. The "planar view" refers to viewing the disposable diaper 1 unfolded in a plane including the longitudinal direction L and the width direction W from above the thickness direction T, and the "planar shape" is grasped in a plan view. Refers to the shape. The "planar direction" is an arbitrary direction parallel to the plane including the width direction W and the longitudinal direction L. Passing through the center of the thickness direction T of the disposable diaper 1, the directions toward and away from the plane spreading in the plane direction are the inner and outer directions of the thickness direction T, respectively. The "skin side" and "non-skin side" mean the side relatively close to the wearer's skin surface and the side far from the wearer's skin surface in the thickness direction T when the disposable diaper 1 is worn by the wearer, respectively. .. These definitions are commonly used not only for disposable diapers 1 but also for the absorbers of disposable diapers 1 and the materials arranged therein.

It should be noted that the fact that the member, structure, shape, etc. are along the longitudinal direction L is not only when the member or the like is parallel to the longitudinal direction L, but also when the component Dx in the longitudinal direction L of the member or the like is a component in the width direction W of the member or the like. It also includes the case where it is larger than Dy (Dx> Dy). Similarly, when a member or the like follows the width direction W, not only when the member or the like is parallel to the width direction W, but also when the component Dy in the width direction W of the member or the like is larger than the component Dx in the longitudinal direction L of the member or the like. It also includes the case where it is large (Dy> Dx). For curved or curved members, etc., the members, etc. are evaluated as described above for the tangents of each point on the curved surface, etc.

As shown in FIG. 1, the disposable diaper 1 includes a front surface sheet 2, a back surface sheet (not shown), and an absorber 3 located between the front surface sheet 2 and the back surface sheet. The front surface sheet 2, the absorber 3, and the back surface sheet are laminated in this order in the thickness direction T. In the present embodiment, the disposable diaper 1 further includes a pair of side sheets 4 and 4 located on both sides of the surface sheet 2 in the width direction W, and a pair of side sheets 4 and 4 on one end side and width in the longitudinal direction L. A pair of tape fasteners 5, 5 located on both sides of the direction W are provided. A pair of three-dimensional gathers 4a and 4a are provided inside the pair of side sheets 4 and 4 in the width direction W. As the front surface sheet 2, the back surface sheet, the side sheet 4 (including the three-dimensional gather 4a), and the tape fastener 5, materials, shapes, and structures known in the art can be used.

FIG. 2 is a plan view showing a configuration example of the absorber 3 according to the embodiment, and FIG. 3 is a cross-sectional view taken along the line III-III of FIG. The absorber 3 is a layer having liquid absorption performance and liquid retention performance, and in the present embodiment, the first absorption layer 11, the second absorption layer 12, the first absorption layer 11 and the second absorption layer 12 An intermediate layer 13 located between the two is provided. The first absorption layer 11, the intermediate layer 13, and the second absorption layer 12 are laminated in this order in the thickness direction T. The first absorption layer 11 is located on the skin side of the absorber 3, and the second absorption layer 12 is located on the non-skin side of the absorber 3. The absorber 3 of the present embodiment has a two-layer structure, but the structure of the absorber 3 is not limited to this example, and may be a one-layer structure excluding the intermediate layer, or the first absorption layer 11 and the second absorption layer. A multi-layer structure in which another intermediate layer and another absorbing layer are further laminated between 12 and 12 may be used. Further, in the present embodiment, the absorber 3 has a substantially rectangular planar shape. At that time, the first absorbing layer 11, the intermediate layer 13, and the second absorbing layer 12 have the same planar shape as each other, and in the example of this figure, they have the same substantially rectangular planar shape as the absorber 3. However, their shapes are not particularly limited, and examples thereof include rectangles having short sides protruding in an arc shape, rounded rectangles, ellipses, and hourglasses. The thickness of the absorber 3 is, for example, 0.5 to 20 mm, preferably 1 to 10 mm.

The first absorption layer 11 is arranged on the intermediate layer 13 side of the first base material 21 and the first base material 21 formed of a sheet having liquid permeability, high water retention and low liquid diffusivity. , A first water absorbing material 23 containing a water absorbing polymer, and the like. The first absorbing layer 11 can be seen as having the first water absorbing material 23 as the absorbing core and the first base material 21 (and the intermediate layer 13) as the core wrap.

The first absorbing layer 11 is further located on at least one of the surface of the first base material 21 on the intermediate layer 13 side and the surface of the intermediate layer 13 on the first base material 21 side, and fixes the first water absorbing material 23. 1 Contains adhesive. Specifically, the first adhesive is applied to the base material side first adhesive 22 located on the surface of the first base material 21 on the intermediate layer 13 side and the surface of the intermediate layer 13 on the first base material 21 side. Includes at least one of the intermediate layer side first adhesives 24 located. In the present embodiment, the first absorption layer 11 includes both the base material side first adhesive 22 and the intermediate layer side first adhesive 24.

In the present embodiment, the first base material 21 is located on the skin side of the first absorption layer 11 and has a substantially rectangular planar shape. The base material side first adhesive 22 is applied to the surface of the first base material 21 on the intermediate layer 13 side with a substantially uniform basis weight. The base material side first adhesive 22 mainly fixes the first water absorbing material 23 on the base material side 21 side to the first base material 21. The intermediate layer side first adhesive 24 is applied to the surface of the intermediate layer 13 on the first base material 21 side with a substantially uniform basis weight. The first adhesive 24 on the intermediate layer side mainly fixes the first water absorbing material 23 on the intermediate layer 13 side to the intermediate layer 13. As a result, the first water absorbing material 23 is firmly fixed in the first absorbing layer 11.

The second absorbing layer 12 is a second base material 26 formed of a sheet having high water retention and high liquid diffusivity, and a second base material 26 which is arranged on the intermediate layer 13 side of the second base material 26 and contains a water absorbing polymer. 2 The water absorbing material 28 and the like are included. The second absorbing layer 12 can be seen as having a second water absorbing material 28 as an absorbing core and a second base material 26 (and an intermediate layer 13) as a core wrap.

The second absorbing layer 12 is further located on at least one of the surface of the second base material 26 on the intermediate layer 13 side and the surface of the intermediate layer 13 on the second base material 26 side, and fixes the second water absorbing material 28. 2 Contains adhesive. Specifically, the second adhesive is applied to the base material side second adhesive 27 located on the surface of the second base material 26 on the intermediate layer 13 side and the surface of the intermediate layer 13 on the second base material 26 side. Includes at least one of the second intermediate layer side adhesives 29 located. In the present embodiment, the second absorbing layer 12 includes both the base material side second adhesive 27 and the intermediate layer side second adhesive 29.

In the present embodiment, the second base material 26 is located on the non-skin side of the second absorption layer 12 and has a substantially rectangular planar shape. However, both ends of the width direction W of the second base material 26 are folded so as to stand upright in the thickness direction T to form both side surfaces of both ends of the width direction W of the second absorption layer 12, respectively. , Both side surfaces of both ends of the first absorption layer 11 in the width direction W are formed. Further ends of both ends of the width direction W of the second base material 26 are further folded inward in the width direction W, and the base material side second adhesive 27 is applied to the skin side surface of the first base material 21. Overlap through. In this way, both ends of the second base material 26 in the width direction W cover the side surface of the second absorption layer 12 in the width direction W, and further cover the side surface of the first absorption layer 11 in the width direction W. The second water absorbing material 28 is sealed in the second absorbing layer 12 in the width direction W, and the first water absorbing material 23 is further sealed in the first absorbing layer 11 in the width direction W. The base material side second adhesive 27 is applied to the surface of the second base material 26 on the intermediate layer 13 side with a substantially uniform basis weight. The base material side second adhesive 27 mainly fixes the second water absorbing material 28 on the base material side 26 side to the second base material 26. The intermediate layer side second adhesive 29 is applied to the surface of the intermediate layer 13 on the second base material 26 side in a substantially uniform basis weight. The second adhesive 29 on the intermediate layer side mainly fixes the second water absorbing material 28 on the intermediate layer 13 side to the intermediate layer 13. As a result, the second water absorbing material 28 is firmly fixed in the second absorbing layer 12.

In the present embodiment, in the absorber 3, the second base material 26 forms the side surface in the width direction W and covers both ends of the first base material 21 in the width direction W. Not limited to the example, the first base material 21 may form a side surface in the width direction W and cover both ends of the second base material 26 in the width direction W. Further, in the absorber 3, both ends in the width direction W are covered with a base material and both ends in the longitudinal direction L are not covered with a base material, but the absorber 3 is not limited to this example and is not limited to this example. Both ends of the width direction W may be covered with a base material, and both ends of the width direction W may not be covered with a base material, or both ends of the width direction W and the longitudinal direction L may be covered with a base material. Good. Further, the absorber 3 has a first water absorbing material 23 and a second water absorbing material 28 as an absorbing core, a first base material 21 as a core wrap on the skin side, and a second base material 26 as a core wrap on the non-skin side. Can be seen as having.

The first water-absorbing material 23 and the second water-absorbing material 28 contain a super absorbent polymer (SAP). The highly water-absorbent polymer is not particularly limited as long as it can absorb and retain water, and examples thereof include particulate or fibrous high water-absorbent polymers. The basis weight of the highly water-absorbent polymer of the first water-absorbing material 23 and the second water-absorbing material 28 can be appropriately adjusted according to the absorption performance required for the disposable diaper 1, and examples thereof include 10 to ^{500 g / m 2 respectively.} , Preferably 100-400 g / m ² . The basis weight of the first water absorbing material 23 and the second water absorbing material 28 may be larger on one side than the other or equivalent. However, "equivalent" means a range in which one is ± 20% of the other. It may further have hydrophilic fibers such as pulp fibers and water-absorbent fibers. The content of the hydrophilic fiber may be, for example, in the range of 0 to 30% by mass, preferably in the range of 0 to 10% by mass, of the first water absorbing material 23 and the second water absorbing material 28. In other words, the content of the highly water-absorbent polymer is, for example, in the range of 70 to 100% by mass, preferably in the range of 90 to 100% by mass, of the first water-absorbent material 23 and the second water-absorbent material 28. Therefore, it can be said that the first water-absorbing material 23 and the second water-absorbing material 28 contain a highly water-absorbent polymer as a main component (70% by mass or more). In the present embodiment, the first water-absorbing material 23 and the second water-absorbing material 28 are composed only of the highly water-absorbent polymer and do not contain hydrophilic fibers. In another embodiment, the first water-absorbent material 23 and the second water-absorbent material 28 include pulp fibers and / or water-absorbent fibers in addition to the highly water-absorbent polymer.

Examples of the highly water-absorbent polymer include starch-based, cellulosic-based, and synthetic polymer-based polymer absorbents. Examples of the starch-based or cellulosic-based highly water-absorbent polymer include a starch-acrylic acid (salt) graft copolymer, a saponified product of a starch-acrylonitrile copolymer, and a crosslinked product of sodium carboxymethyl cellulose. Examples of synthetic polymer-based highly water-absorbent polymers include polyacrylate-based, polysulfonate-based, maleate anhydride-based, polyacrylamide-based, polyvinyl alcohol-based, polyethylene oxide-based, polyasparaginate-based, and polyglutamic acid. Examples thereof include salt-based, polyarginate-based, starch-based, and cellulose-based. In the present embodiment, a polyacrylate-based (particularly sodium polyacrylate-based) highly water-absorbent polymer is preferable. Further, in the present embodiment, it is preferable that 90 to 100% by mass of the highly water-absorbent polymer is composed of highly water-absorbent polymer particles having a particle size of 150 to 500 μm in the absorber 3. Highly water-absorbent polymer particles having such a particle size distribution have a small particle size and are uniform, so that they are easily held by the first adhesive or the second adhesive. The particle size of the highly water-absorbent polymer particles is measured according to the sieving test method described in JIS R 6002: 1998.

The first adhesive and the second adhesive are not particularly limited as long as they are adhesives capable of fixing a highly water-absorbent polymer, and examples thereof include hot melt adhesives. Examples of the hot melt adhesive include olefin hot melt adhesives such as polyethylene, polypropylene, and ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymer hot melt adhesives, and polyamide hot melt adhesives. Examples thereof include thermoplastic elastomer-based hot melt adhesives such as styrene-butylene-styrene copolymers and styrene-isoprene-styrene copolymers, and reactive hot melt adhesives such as moisture-curable urethane prepolymers. In this embodiment, at least one of the first adhesive and the second adhesive is applied in the shape of an elongated line. The width of the lines of the first adhesive and the second adhesive is 50 to 500 μm, preferably 75 to 400 μm, and more preferably 100 to 300 μm in a plan view. The application pattern of each adhesive is not particularly limited, and examples thereof include a continuous or intermittent omega pattern, a spiral pattern, and a line pattern. The basis weight of the first adhesive and the second adhesive can be appropriately adjusted so that the liquid absorbency of the absorber 3 does not significantly decrease, and examples thereof include 3 to ^{50 g / m 2 and preferably 5 to 20 g, respectively.} / M ² . Here, the continuous or intermittent pattern means an arbitrary shape that is continuous or discontinuous in at least one direction of the absorber 3 in the plane direction, for example, the width direction W and the longitudinal direction L. The basis weights of the first adhesive and the second adhesive may be larger on one side than on the other side, or may be equivalent. One of the base material side first adhesive 22 and the intermediate layer side first adhesive 24 may have a larger basis weight than the other, and may be the same, or the base material side second adhesive 27 and the intermediate layer side second adhesive. The basis weight of the adhesive 29 may be larger on one side than on the other side, or may be the same.

As the first base material 21, a sheet having liquid permeability and having high water retention and low liquid diffusivity as a core wrap on the skin side is preferable. As for the high water retention, the amount of water retention indicating water retention ^{is preferably 300 to 800 g / m 2} , preferably 400 to 700 g / m ² . If it is less than 300 g / m ² , when the liquid excrement reaches the absorber 3, it can hardly stay in the first base material 21 temporarily and easily permeates to the first water absorbing material 23 side. .. In the case of more than 800 g / m ² , when the liquid excrement reaches the absorber 3, it stays too much in the first base material 21 and becomes difficult to permeate to the first water absorbing material 23 side. As for the low liquid diffusivity, the Krem water absorption height showing the liquid diffusivity is preferably 0 to 100 mm, more preferably 0 to 50 m. If it exceeds 100 mm, when the liquid excrement reaches the absorber 3, it tends to diffuse in the first base material 21 in the plane direction. The basis weight of the first base material 21 is, for example, 10 to 100 g / m ² , preferably 20 to 80 g / m ² . If it is less than 10 g / m ² , the water retention of the first base material 21 tends to be low. When it exceeds 100 g / m ² , the liquid diffusibility of the first base material 21 tends to be high. The thickness of the first base material 21 is, for example, 0.1 to 5 mm, preferably 0.15 to 3 mm.

Examples of the non-woven fabric having high water retention and low liquid diffusivity as the core wrap on the skin side include air-laid pulp non-woven fabric. The water retention of the air-laid pulp non-woven fabric is relatively high among the non-woven fabrics, and the liquid diffusibility of the air-laid pulp non-woven fabric is relatively low among the non-woven fabrics.

The air-laid pulp non-woven fabric of the present embodiment is formed from hydrophilic fibers containing pulp fibers and a hydrophilic binder such as an acrylic emulsion. The hydrophilic fibers may include regenerated fibers such as other natural fibers and rayon fibers, and thermoplastic fibers imparted with hydrophilicity. However, the air-laid pulp non-woven fabric contains at least pulp fibers as a main component, that is, pulp fibers in an amount of 70% by mass or more of the non-woven fabric. The hydrophilic binders are mainly attached to the surface of the hydrophilic fibers, and the hydrophilic fibers are bonded to each other by the hydrophilic binders at their intersections. Adhesion between hydrophilic fibers forms relatively stable voids between the hydrophilic fibers. Such voids communicate from the skin-side surface of the non-woven fabric to the non-skin-side surface. The fiber length of the hydrophilic fiber is preferably 1 to 20 mm, more preferably 2 to 10 mm from the viewpoint of liquid diffusivity and the like.

Since such an air-laid pulp non-woven fabric (core wrap on the skin side) uses hydrophilic fibers and a hydrophilic binder, the fibers themselves can temporarily retain liquid excrement (eg, urine). In addition, since the fibers are joined at intersections to maintain the skeletal structure (voids between fibers), the voids between the fibers can temporarily hold liquid excrement. Since the voids between the fibers communicate with the surface on the skin side to the surface on the non-skin side, the temporarily held liquid excrement can be moved to the water absorbing material (absorbing core). Further, since the fiber length is relatively short, it is possible to make it difficult for the temporarily held liquid excrement to diffuse in the plane direction. That is, such an air-laid pulp non-woven fabric can have high water retention and low liquid diffusivity.

As the first base material 21, one or more of the above-mentioned non-woven fabrics may be laminated in a plurality of layers.

As the second base material 26, a sheet having high water retention and high liquid diffusivity as a core wrap on the non-skin side is preferable. As for the high water retention, the amount of water retention indicating water retention ^{is preferably 300 to 800 g / m 2} , preferably 400 to 700 g / m ² . If it is less than 300 g / m ² , when the liquid excrement reaches the second base material 26, it can hardly stay in the second base material 26 and easily returns to the second water absorbing material 28 side. In the case of more than 800 g / m ² , when the liquid excrement reaches the second base material 26, it stays too much in the second base material 26 and becomes difficult to diffuse in the plane direction. As for the high liquid diffusivity, the Krem water absorption height showing the liquid diffusivity is preferably 100 mm or more, more preferably 120 mm or more. If it is less than 100 mm, when the liquid excrement reaches the second base material 26, it becomes difficult to diffuse in the second base material 26 in the plane direction. There is no particular upper limit, but 300 mm can be mentioned, for example, in terms of an easy-to-manufacture range. The basis weight of the second base material 26 is 10 to 200 g / m ² , preferably 35 to 150 g / m ² . If it is less than 10 g / m ² , the water retention of the second base material 26 tends to be low. If it exceeds 200 g / m ² , the rigidity of the second base material 26 is increased and the rigidity of the absorber 3 is increased, which makes the disposable diaper 1 (absorbent article) too hard. The thickness of the second base material 26 is, for example, 0.1 to 5 mm, preferably 0.15 to 3 mm.

Examples of the non-woven fabric having high water retention and high liquid diffusivity as the core wrap on the non-skin side include spunlace non-woven fabric having predetermined characteristics. The water retention of the spunlace non-woven fabric is relatively high among the non-woven fabrics, and the liquid diffusivity of the spunlace non-woven fabric is relatively high among the non-woven fabrics.

The spunlace nonwoven fabric of this embodiment is formed from hydrophilic fibers. Examples of the hydrophilic fiber include rayon fiber, and may also include natural fiber such as pulp fiber, other regenerated fiber, and thermoplastic fiber imparted with hydrophilicity. When rayon fibers are used as hydrophilic fibers, the cross section of the rayon fibers is irregular petal-shaped, and therefore, the surface of the rayon fibers has a plurality of streaks in the axial direction of the fibers. In other words, the rayon fiber has a plurality of convex portions extending along the axis of the fiber and a plurality of concave portions located between adjacent convex portions on the surface. The hydrophilic fibers are entangled with each other without being fused. The entanglement of the hydrophilic fibers forms voids between the hydrophilic fibers. The fiber length of the hydrophilic fiber is preferably 20 to 80 mm, more preferably 30 to 60 mm from the viewpoint of liquid diffusivity and the like.

Since such a spunlace non-woven fabric (core wrap on the non-skin side) uses hydrophilic fibers, the fibers themselves can temporarily retain liquid excrement (eg, urine). In addition, since the fibers are only entangled and it is difficult to maintain the shape of the voids between the fibers, it is difficult to allow the temporarily held liquid excrement to permeate. Further, since it is difficult for liquid excrement to permeate and the fiber length of the fiber is relatively long, it is easy to diffuse the retained liquid excrement. Further, since there are a plurality of streaks along the axial direction of the fiber on the fiber surface, it is easier to diffuse the body fluid held along the fiber by the capillary phenomenon. That is, such a spunlace non-woven fabric can have high water retention and high liquid diffusivity.

As the second base material 26, one or more of the above-mentioned non-woven fabrics may be laminated in a plurality of layers.

In the present embodiment, the water retention amount indicating the water retention of the air-laid pulp non-woven fabric as the first base material 21 is 300 to 800 g / m ² , which is the highest among the non-woven fabrics for core wrap. On the other hand, the water retention amount of the spunlace non-woven fabric having hydrophilic fibers as the second base material 26 is 300 to 800 g / m ² , which is the highest among the non-woven fabrics for core wrap. Therefore, the water retention of the air-laid non-woven fabric is as high as that of the spunlace non-woven fabric having hydrophilic fibers.
The Krem water absorption height, which indicates the liquid diffusivity of the air-laid pulp non-woven fabric, is 0 to 100 mm, which is low among the non-woven fabrics for core wrap. On the other hand, the Krem water absorption height showing the liquid diffusivity of the spunlace non-woven fabric having hydrophilic fibers is 100 mm or more, which is the highest among the non-woven fabrics for core wrap. More preferably, the Krem water absorption height (diffusivity) of the air-laid pulp non-woven fabric (first base material 21) is 1/2 or less of the Krem water absorption height (diffusibility) of the spunlace non-woven fabric (second base material 26). is there. One of the reasons for obtaining such properties is that the fiber lengths of the plurality of fibers constituting the air-laid pulp non-woven fabric are shorter than the fiber lengths of the plurality of fibers constituting the spunlace non-woven fabric having hydrophilic fibers. Be done.

The intermediate layer 13 is not particularly limited as long as it is a liquid-permeable sheet. Examples of the intermediate layer 13 include a liquid-permeable non-woven fabric, a hydrophilic non-woven fabric, and a laminated non-woven fabric thereof. For example, it is formed from polyolefin fibers such as polyethylene (PE) and polypropylene (PP), polyester fibers such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), or a combination thereof. Examples include spunbonded non-woven fabrics and air-through non-woven fabrics. It is preferable that these synthetic fibers are hydrophilized by a known method. Alternatively, for example, an air-laid nonwoven fabric in which hydrophilic fibers such as pulp fibers and rayon fibers are coated with a hydrophilic binder, and spunlaced nonwoven fabrics in which the above-mentioned hydrophilic fibers and the above-mentioned synthetic fibers are combined can be mentioned. In this embodiment, an air-through non-woven fabric using hydrophilized polyethylene and polypropylene fibers is used. As the intermediate layer 13, one or more of the above-mentioned non-woven fabrics may be laminated in a plurality of layers. The basis weight of the intermediate layer 13 is, for example, 10 to 100 g / m ² , preferably 15 to 80 g / m ² . The thickness of the intermediate layer 13 is, for example, 0.1 to 5 mm, preferably 0.15 to 3 mm.

In the present embodiment, the absorber 3 is located in a region inside the both ends of the absorber 3 in the width direction W in a plan view, and the first base material 21 and the intermediate layer 13 are formed by the first adhesive. The second base material 26 and the intermediate layer 13 are second adhesives, and each has a bonding region 7 (longitudinal bonding region) bonded to each other in the thickness direction T. In the present embodiment, the absorber 3 is located in a region inside both ends of the absorber 3 in the width direction W and has a pair of joining regions 7 and 7 extending along the longitudinal direction L. However, in the present embodiment, the inside of both ends of the width direction W of the absorber 3 means the both ends of the width direction W of the absorber 3 when the maximum dimension of the width direction W of the absorber 3 is 100%. The side closer to the longitudinal center line CL than the position 5% from. Further, the joining region 7 may extend along the width direction W.

In the present embodiment, in the absorber 3, the space formed between the first base material 21 on the skin side and the second base material 26 on the non-skin side is formed in a plan view by some bonding regions 7. Divided into multiple areas. In the bonding region 7, a part of the first base material 21 and a part of the second base material 26 facing the first base material 21 are pressed with an adhesive in the thickness direction T while interposing the intermediate layer 13 (example: hot). It is formed by melt adhesive) or crimping (example: embossing). Therefore, the bonding region 7 of the first absorption layer 11 and the bonding region 7 of the second absorption layer 12 completely coincide with each other in the thickness direction T. In the present embodiment, the bonding region 7 can be said to be a region (non-existent region) that does not contain the water-absorbent polymer and hydrophilic fibers. Therefore, the first water absorbing material 23 is arranged in the first absorbing layer 11 with a substantially uniform basis weight except for the joining region 7, and the second water absorbing material 28 is arranged in the second absorbing layer except for the joining region 7. It is arranged in 12 with a substantially uniform basis weight.

In the present embodiment, the absorber 3 has the pair of joining regions 7 and 7 in three regions (existing regions) including the water absorbing material in the width direction W, that is, both the central arrangement region Awc and the width direction W thereof. It is divided into a pair of outer arrangement areas Awe and Awe located on the outer side. However, the pair of joining regions 7 and 7 are strip-shaped regions that are extended in a slit shape in the longitudinal direction L and are arranged at predetermined intervals on both sides in the width direction W with the longitudinal center line CL in between. The joint region 7 is formed so as to straddle the central portion in the longitudinal direction L, particularly the center line CW in the width direction. The pattern of the pair of joining regions 7 and 7 in a plan view is, for example, a pattern formed so that the distance between the two is constant along the longitudinal direction L. However, the pattern of the pair of joining regions 7 and 7 may be formed so as to be narrow near the center of the longitudinal direction L and expand toward both outer sides of the longitudinal direction L, for example. In the present embodiment, the dimensions of the central arrangement region Awc and the outer arrangement region Awe in the width direction W are, for example, 30 to 60% and 20 to 10%, assuming that the maximum dimension of the width direction W of the absorber 3 is 100%. Can be mentioned. Further, the dimension of the width direction W of the bonding region 7 is, for example, 5 to 10%, where the maximum dimension of the width direction W of the absorber 3 is 100%. Further, the dimension of the bonding region 7 in the longitudinal direction L is, for example, 30 to 100%, where the maximum dimension of the absorber 3 in the longitudinal direction L is 100%.

In the present embodiment, the absorber 3 is provided with a pair of embossed portions 8 and 8 extending in the longitudinal direction L and arranged at intervals in the width direction W. The pair of embossed portions 8 and 8 are located within the pair of joining regions 7 and 7. Each embossed portion 8 is extended so as to pass through the central portion in the longitudinal direction L, and has a structure in which the surface on the skin side and the surface on the non-skin side are recessed inward in the thickness direction T. The pair of embossed portions 8 and 8 have a straight line shape parallel to each other along the longitudinal direction L in a plan view. The shapes of the pair of embossed portions 8 and 8 are line-symmetrical with respect to the longitudinal center line CL. The size of the embossed portion 8 in the width direction W is preferably 0.5 to 4 mm, more preferably 1 to 2 mm. The dimension of the embossed portion 8 in the longitudinal direction L is, for example, 20 to 90%, where the maximum dimension of the absorber 3 in the longitudinal direction L is 100%. However, the shapes of the pair of embossed portions 8 and 8 are not limited to this example, and may have other shapes. As another shape, for example, in a plan view, a shape in which the distance between each other in the width direction W increases from the center toward both ends along the longitudinal direction L, that is, convex with respect to the longitudinal center line CL. Examples thereof include a gentle arc-shaped shape that becomes concave with respect to the longitudinal center line CL, and a combination of these shapes (including the shape of FIG. 2). In the present embodiment, the absorber 3 is extended along the longitudinal direction L at both ends of the longitudinal direction L in the joint region 7, and a pair of embossed portions arranged at intervals in the width direction W. 18 and 18 are further provided.

Next, a method for producing the absorber 3 will be described.
First, while moving the sheet for the second base material 26 in the longitudinal direction L, the hot melt adhesive for the second base material 27 on the base material side is applied onto the sheet for the second base material 26. Next, the highly water-absorbent polymer was applied from the highly water-absorbent polymer supply device to both end portions and the central portion in the width direction W of the sheet for the second base material 26 coated with the hot-melt adhesive for the second base material 27 on the base material side. Spray upward along the longitudinal direction L. Next, the sheet for the intermediate layer 13 coated with the hot melt adhesive for the second adhesive 29 on the intermediate layer side and the hot melt adhesive for the first adhesive 24 on the intermediate layer side on both sides is subjected to high water absorption on the sheet for the second base material 26. A hot-melt adhesive for the second adhesive 29 on the intermediate layer side is laminated on the polymer with the highly water-absorbent polymer side. Next, while moving the laminate in the longitudinal direction L, the highly water-absorbent polymer is applied from another highly water-absorbent polymer supply device, and the intermediate layer 13 is coated with the hot-melt adhesive for the first adhesive 24 on the intermediate layer side. The sheet is sprayed along the longitudinal direction L on both end portions and the center portion in the width direction W. Next, the sheet for the first base material 21 obtained by applying the hot melt adhesive for the first adhesive 22 on the base material side onto the highly water-absorbent polymer on the sheet for the second base material 26 is first bonded to the base material side. The hot melt adhesive for agent 22 is laminated on the highly water-absorbent polymer side. Then, after folding each of both side portions of the second base material 26 sheet in the width direction W onto the first base material 21 sheet, the thickness is increased by passing the laminate through a pair of press rolls and pressing the layers. Adjust to form absorber 3.

Next, a method for producing an absorbent article using the absorber 3 will be described.
A liquid-permeable surface sheet 2 (including a pair of side sheets 4 and 4 with three-dimensional gathers) is attached to the upper surface (surface of the first base material 21) of the absorber 3 produced as described above. Next, a liquid-impermeable back sheet is attached to the lower surface of the absorber 3 (the surface of the second base material 26). Next, a pair of tape fasteners 5 and 5 are attached to both ends of the back sheet in the width direction W of one end in the longitudinal direction L. As a result, the disposable diaper 1 is manufactured.

In the absorber 3, in the skin-side first base material 21 and the non-skin-side second base material 26 that function as core wraps, the air-laid pulp non-woven fabric of the first base material 21 and the hydrophilic fibers of the second base material 26 are formed. The amount of water retained in the spunlace non-woven fabric is, for example, 300 to 800 g / m ² , which are high. That is, the water retention of the air-laid pulp non-woven fabric of the first base material 21 is as high as the water retention of the spunlace non-woven fabric having hydrophilic fibers of the second base material 26. Further, the creme water absorption heights of the air-laid pulp non-woven fabric of the first base material 21 and the spunlace non-woven fabric having hydrophilic fibers of the second base material 26 are, for example, 0 to 100 mm and 100 mm or more, which are low in the air-laid pulp non-woven fabric and span. High with lace non-woven fabric. That is, the liquid diffusibility of the air-laid pulp non-woven fabric of the first base material 21 is lower than the liquid diffusibility of the spunlace non-woven fabric of the second base material 26.
Therefore, when liquid excrement (eg, urine) is excreted in the disposable diaper 1 (absorbent article) to which the absorber 3 is applied, the first base material 21 on the skin side has high water retention and low liquid. Due to its diffusivity, its excrement can be quickly absorbed and temporarily stored in a small area without much diffusion (spot absorption). Further, the second base material 26 on the non-skin side absorbs excrement arriving through the first base material 21 due to its high water retention and high liquid diffusivity, and diffuses it over a wide range in the plane direction. It can be absorbed by a wide range of highly water-absorbent polymers. Therefore, even if a large amount of excrement reaches the second base material 26 via the first base material 21, the water retention of the excrement by the second base material 26 and the absorption by the highly water-absorbent polymer are not in time, and urine It is possible to suppress the situation where the urine is congested. In other words, the first substrate 21 temporarily stores the excrement (and gradually releases the excrement) for water retention, diffusion and subsequent absorption of the highly water-absorbent polymer of the second substrate 26. You can earn time. Therefore, it is possible to prevent the excrement from remaining on the surface sheet 2 and causing a feeling of leakage and the occurrence of lateral leakage. In particular, by storing the excrement in a narrow area, it becomes difficult for the wearer to feel the presence of the excrement as compared with the case where the excrement is stored in a wide area (when the first base material 21 has high liquid diffusivity). , The feeling of leakage can be made more difficult to remember.

As a preferred embodiment in the present embodiment, in the absorber 3, the air-laid pulp non-woven fabric of the first base material 21 contains hydrophilic fibers containing pulp fibers and a hydrophilic binder. Therefore, the fiber itself can retain liquid excrement such as urine. Further, since the fibers are joined by a hydrophilic binder at the mating contact point, it is easy to maintain the skeleton structure (voids between the fibers) by the fibers, and it is possible to easily hold the liquid in the gaps. As a result, the first base material 21 can more reliably and quickly absorb its excrement and temporarily store it.

In a preferred embodiment of the present embodiment, in the absorber 3, the fiber length of the fibers of the air-laid pulp non-woven fabric is shorter than the fiber length of the fibers of the spunlace non-woven fabric. Therefore, the liquid diffusivity of liquid excrement such as urine in the first base material 21 can be relatively lowered. Thereby, the first base material 21 can be more reliably temporarily stored in a narrow area without diffusing excrement so much.

As a preferred embodiment in the present embodiment, in the absorber 3, a plurality of convex portions extending along the axis of the fibers and adjacent convex portions are provided on the surface of the fibers (eg, rayon fibers) constituting the spunlace non-woven fabric. It has a plurality of recesses located between the portions. Therefore, the second base material 26 can easily diffuse liquid excrement such as urine along the convex portion and the concave portion thereof. That is, the liquid diffusivity of the liquid excrement in the second base material 26 can be made relatively higher. As a result, the second base material 26 can more reliably retain water and diffuse the excrement in the plane direction.

As a preferred embodiment in the present embodiment, the absorber 3 is divided into a first absorption layer 11 and a second absorption layer 12 with an intermediate layer 13 interposed therebetween. Therefore, the excrement absorbed by the first base material 21 on the skin side reaches the second base material 26 to retain and diffuse water, and a part of the excrement is partially formed in the non-woven fabric of the intermediate layer 13 in the middle. , Can be retained and diffused. That is, the non-woven fabric of the intermediate layer 13 located on the non-skin side of the first absorption layer 11 can exhibit the same function as the second base material 26 located on the non-skin side of the second absorption layer 12. As a result, it is possible to further suppress the situation where too much excrement reaches the second base material 26 on the non-skin side via the first base material 21, and the excrement remains on the surface sheet 2 to cause a feeling of leakage. Or, it is possible to further suppress the occurrence of lateral leakage. At the same time, the first water absorbing material 23 of the first absorbing layer 11 on the skin side can be used at an early stage, whereby the water absorbing material can be efficiently used in the thickness direction.

As a preferred embodiment in the present embodiment, in the absorber 3, the non-woven fabric of the intermediate layer 13 may contain pulp fibers. Therefore, the excrement absorbed by the first base material 21 on the skin side reaches the second base material 26 to retain and diffuse water, and a part of the excrement is further formed in the non-woven fabric of the intermediate layer 13 in the middle. Water can be reliably retained and diffused.

As a preferred embodiment in the present embodiment, in the absorber 3, the basis weight of the water absorbing material in the region between the pair of bonding regions (longitudinal joint regions) 7 and 7 (central arrangement region Awc) is the pair of bonding regions 7. , 7 is larger than the basis weight of the water absorbing material in each of the outer regions (outer arrangement region Awe). That is, in the central region (central arrangement region Awc) and both end regions (outer arrangement region Awe) of the absorber 3 separated by the pair of joining regions 7 and 7, the basis weight of the water absorbing material in the central region is relative. It is made larger. As a result, while ensuring the absorption capacity in the central region where the amount of liquid excrement excreted is large, the pair of junction regions 7 and 7 restrict the diffusion of the liquid excrement in the width direction W, and the longitudinal direction L. It can induce diffusion into and the entire absorber can be used efficiently. In addition, the regions at both ends can absorb the liquid excrement leaked in the width direction and suppress the occurrence of lateral leakage.

As a preferred embodiment in the present embodiment, in the present absorber 3, in the bonding region 7, the first base material 21 and the intermediate layer 13 are bonded to the first adhesive (base material side first adhesive 22 and intermediate layer side first adhesive). At least one of the second base material 26 and the intermediate layer 13 is bonded to each other with the second adhesive (at least one of the base material side second adhesive 27 and the intermediate layer side second adhesive 29). ) To join each other. Then, in the bonding region 7, the first adhesive and the second adhesive contact each other through the plurality of communication holes of the intermediate layer 13 to bond the first base material 21 and the second base material 26 to each other. .. That is, in the absorber 3, the first base material 21 which is one outer surface in the thickness direction T where strong shear stress can be generated and the second base material 26 which is the other outer surface are joined to each other. As a result, in the absorber 3, a relatively large planar shear stress is generated inside the absorber 3 due to the planar force acting on the first base material 21 and the planar force acting on the second base material 26. Even if the portion of the first absorption layer 11 and the portion of the second absorption layer 12 are deformed in different directions, the deformation can be suppressed to be small. As a result, it is possible to prevent a situation in which the portion of the first absorbing layer 11 and the portion of the second absorbing layer 12 slip in different directions and the absorber 3 breaks or loses its shape. In this way, the present absorber 3 can strengthen the bond between the first absorption layer 11 and the second absorption layer 12, and can have a structure that does not easily break or lose its shape even when shear stress occurs. .. That is, even if the absorber 3 containing the highly water-absorbent polymer absorbs excrement and swells to thicken in the thickness direction T, it is possible to suppress breakage and shape loss due to shear stress.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to such examples.

(A) Samples As samples of Examples and Comparative Examples, the absorber shown in FIG. 2 (however, the embossed portion and the bonding region are omitted), and the surface material (equivalent to the front sheet) and the back material (equivalent to the back sheet) are used as the absorber. ) Was attached to each other to prepare an absorbent article, which was prepared by the following [method for producing an absorber]. However, the non-woven fabric used is as described in [Non-woven fabric] below.

[Non-woven fabric]
(1) ALP (Airlaid Pulp) Nonwoven Fabric NBKP fluff pulp sheet is crushed and conveyed by a hammer mill, and ^{laminated at 53 g / m 2} using an airlaid forming machine to form a web. An acrylic binder of 7 g / m ² is spray-coated on the web, and then dried with a suction band type dryer to cure the acrylic binder to obtain an ALP non-woven fabric.
(2) Spanlace non-woven fabric 1
A three-layered web is formed by laminating a card web layer of rayon fiber (1.7 Dtex-40 mm fiber length) manufactured by Lening, an airlaid layer of crushed pulp, and a card web layer similar to the above in this order. The web is entangled with fibers by water jet processing to obtain a spunlace non-woven fabric 2 (basis weight 55 g / m ² ).
(3) Span lace non-woven fabric 2
A three-layered web is formed by laminating a card web layer of rayon fiber (1.7 Dtex-40 mm fiber length) manufactured by Lening, an airlaid layer of crushed pulp, and a card web layer similar to the above in this order. The web is entangled with fibers by water jet processing to obtain a spunlace non-woven fabric 3 (basis weight 35 g / m ² ).
(4) Span lace non-woven fabric 3
A card web of rayon fiber (1.7 Dtex-40 mm fiber length) manufactured by Lening is formed. The web is entangled with fibers by water jet processing to obtain a spunlace non-woven fabric 3 (basis weight 43 g / m ² ).
(5) Tissue Obtain ^{18.5 g / m 2 of tissue made of Nittoku.}

[Manufacturing method of absorber (absorbent article)]
(1) The non-woven fabric for the second base material 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 highly water-absorbent polymer (Aquakeep manufactured by Sumitomo Seika Chemicals Co., Ltd.) is uniformly sprayed on the upper surface of the non-woven fabric for the second base material in a width of 100 mm at the center in the width direction ^{at a basis weight of 225 g / m 2.}
(3) Cut an air-through non-woven fabric (for intermediate layer) with a basis weight of 40 g / m ² into a width of 100 mm and a length of 400 mm, and use a spiral coater to apply hot melt adhesive to both sides and the entire surface with a basis weight of 7 g / m ^2. Apply at.
(4) The air-through non-woven fabric of the above (3) is placed on the non-woven fabric for the second base material of the above (2). A highly water-absorbent polymer (Aquakeep manufactured by Sumitomo Seika Chemicals Co., Ltd.) is uniformly sprayed on the upper surface of the air-through non-woven fabric at a width of 100 mm at the center in the width direction ^{at a basis weight of 225 g / m 2.}
(5) The non-woven fabric for the first base material is cut into a width of 100 mm and a length of 400 mm, and a hot melt adhesive is applied to the entire surface of one side thereof at a ^{basis weight of 7 g / m 2 using a spiral coater.}
(6) The non-woven fabric for the first base material is placed on the upper surface of the air-through non-woven fabric of (4) above, with the side coated with the hot melt adhesive facing down. Then, 20 mm portions on both sides of the non-woven fabric for the second base material in the width direction are folded inward to seal the non-woven fabric. As a result, the absorber 3 is formed.
(7) After that, the absorber 3 is pressed by a press machine whose press pressure is adjusted so that the thickness of the absorber 3 becomes 2.5 mm. As a result, an absorber having a uniform thickness is produced.
(8) However, when performing absorption evaluation (diffusion distance), a hydrophilic surface material (equivalent to a front sheet) using an air-through non-woven fabric and a back material (equivalent to a back sheet) using a breathable film are further laminated to form an absorbent article. Manufacture and evaluate.

(2) Evaluation method The non-woven fabric, the absorbent body, and the absorbent article were evaluated by the following methods.

[Basis weight of sheet (nonwoven fabric, absorber)]
(1) A portion having a size of 5 cm × 5 cm is cut out from the sheet and used as a sample.
(2) The sample is dried in an air atmosphere of 100 ° C. or higher.
(3) Measure the mass of the sample.
(4) Divide the measured value of mass by the area of the sample to calculate the basis weight of the sample.
(5) The value obtained by averaging the basis weights of 10 samples is defined as the basis weight of the sheet.

[Thickness of sheet (nonwoven fabric, absorber)]
(1) A portion having a size of 5 cm × 5 cm is cut out from the sheet and used as a sample.
(2) The sample is dried in an air atmosphere of 100 ° C. or higher.
(3) using a thickness gauge with a measuring element of 15cm ² (the Ltd. Daiei Chemical Seiki Seisakusho Model FS-60DS), to measure the thickness of the sheet under the conditions of measuring load of 3 g / cm ^2.
(4) Measure the thickness of three places with one sample, and use the average value of them as the thickness of the sheet.

[Absorption rate and rewet]
FIG. 4 is a schematic view showing a jig for measurement for evaluating the performance of the absorber. FIG. 4A is a side view, and FIG. 4B is a front view.
(1) An absorber is placed on a substantially U-shaped surface 31 of a jig 30 having a shape as shown in FIG. At that time, align the central part of the jig with the central part of the absorber.
(2) A burette (80 cc / 10 Sec) is set so that the tip of the burette is located at the center of the absorber and at a position 10 mm from the surface of the absorber, and 40 cc of artificial urine is dropped. However, artificial urine is prepared by dissolving 200 g of urea, 80 g of sodium chloride, 8 g of magnesium sulfate, 3 g of calcium chloride and 1 g of dye (Blue No. 1) in 10 L of ion-exchanged water.
(3) The time from the start of dropping artificial urine until the artificial urine is absorbed by the absorber is measured and recorded as the absorption time.
(4) After 25 secs from the start of artificial urine dripping, the absorber is lowered from the jig and placed on a flat surface.
(5) After 30 Secs from the start of artificial urine dripping, place a filter paper (50 g of Advantech-No. 2) and a weight (3.5 kg) at the dripping position and leave it for 30 seconds.
(6) The weight increase of the filter paper after being left for 30 seconds is measured and recorded as a rewet.
(7) The absorption time and rewet are measured with 5 samples, and the average value is calculated.

[Diffusion distance]
(1) An absorber is placed on a substantially U-shaped surface 31 of a jig 30 having a shape as shown in FIG. At that time, align the central part of the jig with the central part of the absorber. In this case, the absorber has a front surface material on one side and a back surface material on the other side.
(2) A burette (80 cc / 10 Sec) is set so that the tip of the burette is located at the center of the absorber and at a position 10 mm from the surface of the absorber, and 40 cc of artificial urine is dropped.
(3) After 30 Secs from the start of artificial urine dripping, the tip of the diffusion of artificial urine is recorded by tracing on the front surface (front surface material) and the back surface (back fimul) of the absorber with magic. The absorber is placed flat, and the diffusion length at the center in the width direction (distance from one tip to the other in the longitudinal direction in diffusion) is measured on the front and back surfaces, and the upper diffusion distance and the lower layer are measured, respectively. Record as diffusion distance.
(4) The upper layer diffusion distance and the lower layer diffusion distance are measured with five samples, and the average value is calculated.

[Water retention]
(1) The non-woven fabric is cut into a size of 100 mm × 100 mm. Then, n non-woven fabrics are stacked so that the mass of one sample is 1 g or more, and the mass Wa (g) of this sample is measured.
(2) Clip both ends of the sample to the stainless wire mesh. Then, the sample and the wire mesh were placed diagonally 20 mm below the surface of the water in a water tank containing pure water at 20 ° C. to prevent bubbles from appearing, and then left for 60 seconds.
(3) Take out the sample and the wire mesh, remove the clip at the other end, leaving the clip at one end of the sample, and hang it vertically for 120 seconds to drain the water.
(4) The sample is removed from the wire mesh, and the mass Wb (g) of the sample after water absorption is measured.
(5) The water absorption amount (water retention amount) of the sample is calculated by the following formula.
Water retention of sample (g / m ² ) = [Wb-Wa] (g) / (n × 0.01) (m ² )
(6) The amount of water retained in the samples is measured with five samples, and the average value is calculated.

[Water permeability (strike through)]
5 and 6 are schematic views showing a liquid permeability measuring machine for measuring the water permeability (strike through) of the non-woven fabric. FIG. 5 is a side view and FIG. 6 is a partial plan view. It is a liquid permeability measuring machine (manufactured by INTEC Inc., model: Lister). As shown in FIG. 5, a physiological saline solution (0.9 mass% sodium chloride aqueous solution) as a test solution was supplied to the non-woven fabric sample 44 placed on the base plate 46 through the strike-through plate 43, and the test solution was released. The time (seconds) to pass through the sample 44 is measured.
(1) Five sheets of 100 x 100 mm filter paper (filter paper grade 989 for LISTER manufactured by Ahlstrom) are placed on a base plate 46 of 125 x 125 mm plexiglass (made of acrylic resin) to form a filter paper layer 45, and 125 x 125 x A 125 mm non-woven fabric sample 44 is placed. Further, the strike-through plate 43 is placed on the strike-through plate 23 so that the central hole 47 having an inner diameter of 25 mm is directly below the magnetic valve 42.
(2) 5 ml of physiological saline is placed in the container 41, and the physiological saline is supplied to the sample 44 through the central hole 47 of the strike-through plate 43 by the magnetic valve 42.
(3) In the strike-through plate 43, the electrically conductive physiological saline passes between the two electrodes 48 on the bottom surface of the central hole 47, so that a current flows and the timer starts. Further, when the sample 44 is infiltrated and the physiological saline solution is completely absorbed by the filter paper layer 45, the current is cut off and the timer is stopped. The time (seconds) during this period is measured.
(4) This time (seconds) of the sample is measured with five samples, and the average value is calculated.

[Krem water absorption height]
The Krem water absorption height of the non-woven fabric is measured according to the water absorption test method according to the Krem method of JIS P 8141: 2004.
(1) A non-woven fabric is cut into a size of 230 mm in length × 25 mm in width to prepare a sample, and the initial mass of the sample: W0 (g) is measured.
(2) A rectangular parallelepiped immersion container having a length of 170 mm, a width of 90 mm, and a depth of 40 mm is filled with artificial urine to a height of 35 mm.
(3) The sample is fixed to a hanging tool, and the lower end in the length direction: 30 mm is immersed in artificial urine and left for 5 minutes.
(4) After 5 minutes, the height at which the artificial urine rises is measured as the Krem water absorption height.
(5) The Krem water absorption height of the sample is measured with five samples, and the average value is calculated. If the suction height exceeds 190 mm, the length of the sample is appropriately lengthened for measurement.

(3) Evaluation results The evaluation results are shown in Tables 1 to 3. However, Table 1 shows the characteristics of the non-woven fabric used as the first base material (skin-side core wrap) in the absorbent body and the absorbent article of Examples and Comparative Examples. Table 2 shows the characteristics of the non-woven fabric used as the second base material (core wrap on the non-skin side) in the absorbent body and the absorbent article of Examples and Comparative Examples. Table 3 shows the characteristics of the absorbent body and the absorbent article of Examples and Comparative Examples using the first base material of Table 1 and the second base material of Table 2.

As shown in Table 1, air-laid pulp (ALP) nonwovens, high water retention property (water retention capacity ^{683.5g / m 2> 300g / m} 2) and low liquid-diffusivity (Klemm water height 30.7 mm <100 mm) Indicated. That is, the non-woven fabric had good characteristics (evaluation 〇) as the first base material. However, the tissue showed low water retention (water retention 75.8 ^{g / m 2} <300 g / m ² ), and the spunlace non-woven fabric 1 showed high liquid diffusivity (Krem water absorption height 173.0 mm> 100 mm). That is, these non-woven fabrics had poor characteristics (evaluation ×) as the first base material.

As shown in Table 2, spunlace nonwoven 1-3, high water retention (water retention capacity ^{458.0,455.7,437.7g / m 2> 300g / m} 2) and high liquid diffusing properties (Klemm water height 173.0, 138.0, 150.5 mm> 100 mm). That is, these non-woven fabrics had good characteristics (evaluation 〇) as the second base material. However, the air-laid pulp (ALP) non-woven fabric showed low liquid diffusivity (Krem water absorption height 30.7 mm <100 mm) as described above. That is, this non-woven fabric had poor characteristics (evaluation ×) as the second base material.

In the absorbers (absorbent articles) of Examples and Comparative Examples using the first base material of Table 1 and the second base material of Table 2, the combination of non-woven fabrics having a good evaluation (Examples 1 to 3) was high. Absorption rate (7.33, 8.61, 9.21 seconds <10 seconds), low rewet (0.08, 0.19, 0.08 g <1 g), low liquid diffusivity in the upper layer (upper layer diffusion 79, It showed 75, 91 mm <100 mm) and high liquid diffusivity in the lower layer (lower layer diffusion 169, 155, 169 mm> 100 mm). That is, these had good characteristics as an absorber (evaluation 〇). In the absorber (absorbent article) of such an embodiment, the first base material (core wrap on the skin side) temporarily stores liquid excrement (eg, urine) and excretes it in the plane direction. While suppressing the diffusion of substances, it is permeated to the lower layer side (the side of the second base material), and the second base material (core wrap on the non-skin side) diffuses the excrement in the plane direction, and each water absorbing material (high water absorption). The polymer) absorbs excrement. As described above, the absorber of this example is not retained by free water (neither the base material or the core wrap nor each water absorbing material or the highly water absorbing polymer until the highly water absorbing polymer absorbs excrement. Since it can reduce free-moving excrement), it has a high absorption rate and less rewetting. As a result, even immediately after the excrement is discharged, there is no lateral leakage, no leakage feeling is generated, and it is possible to obtain a dry and comfortable wearing feeling.

On the other hand, the combination containing the non-woven fabric (Comparative Examples 1 to 3) having a poor evaluation did not show good characteristics in any of absorption rate, rewet, upper layer diffusion, and lower layer diffusion. In Comparative Example 1, the absorption rate became slower (12.21 seconds> 10 seconds). The main reason is considered to be that the amount of water retained in the first base material is small. In this case, for example, the wearer may feel a sense of leakage. In Comparative Example 2, the upper layer diffusion became large (177 mm> 100 mm). The main reason is considered to be the high Krem water absorption height of the first base material. In this case, for example, since the contact area where the wearer's skin comes into contact with the liquid excrement becomes large, the wearer's skin may become dirty or a feeling of leakage may be felt. In Comparative Example 3, the lower layer diffusion became smaller (72 mm <100 mm) and the rewet increased (1.26 g> 1 g). It is considered that the main reason is that the liquid excrement of the second base material is low in liquid diffusivity, so that the liquid excrement is concentrated in one place and cannot be sufficiently absorbed in the absorbing body. In this case, for example, excrement appears on the surface of the absorber, so that the wearer's skin may become dirty or a feeling of leakage may be felt.

The absorbent body for the absorbent article of the present invention is not limited to each of the above-described embodiments, and is appropriately combined or modified within a range that does not deviate from the purpose and purpose of the present invention and does not cause technical contradiction. Etc. are possible.

1 Disposable diapers (absorbent articles)
3 Absorbent 21 1st base material 23 1st water absorbing material 26 2nd base material 28 2nd water absorbing material

Claims (7)

Absorbent for absorbent articles
A first base material containing an air-laid pulp non-woven fabric placed on the skin side,
A second base material, which is arranged on the non-skin side and contains a spunlace non-woven fabric having hydrophilic fibers,
A water-absorbing material contained between the first base material and the second base material and containing a highly water-absorbent polymer as a main component,
With
The water retention amount indicating the water retention of the air-laid pulp non-woven fabric and the water retention of the spunlace non-woven fabric is 300 to 800 g / m ² .
The Krem water absorption height showing the liquid diffusivity of the air-laid pulp non-woven fabric is 0 to 100 mm.
The Krem water absorption height showing the liquid diffusivity of the spunlace non-woven fabric is 100 mm or more.
Absorber. The air-laid pulp non-woven fabric is
With multiple hydrophilic fibers, including multiple pulp fibers,
A hydrophilic binder that covers the plurality of hydrophilic fibers, and
including,
The absorber according to claim 1. The fiber lengths of the plurality of fibers constituting the air-laid pulp nonwoven fabric are shorter than the fiber lengths of the plurality of fibers constituting the spunlaced nonwoven fabric.
The absorber according to claim 1 or 2. Each of the plurality of fibers constituting the spunlace non-woven fabric has a plurality of convex portions extending along the axis of the fibers and a plurality of concave portions located between adjacent convex portions on the surface.
The absorber according to any one of claims 1 to 3. The absorber is
The first absorption layer and
With the second absorption layer
An intermediate layer formed of a non-woven fabric located between the first absorption layer and the second absorption layer,
Further prepare
The first absorption layer is
With the first base material
The first water-absorbing material, which is arranged on the intermediate layer side of the first base material, contains a highly water-absorbing polymer, and is a part of the water-absorbing material,
A first adhesive that is located on at least one of the surface of the first base material on the intermediate layer side and the surface of the intermediate layer on the first base material side and fixes the first water absorbing material.
Including
The second absorption layer is
With the second base material
A second water-absorbing material, which is arranged on the intermediate layer side of the second base material, contains a highly water-absorbing polymer, and is a part of the water-absorbing material.
A second adhesive that is located on at least one of the surface of the second base material on the intermediate layer side and the surface of the intermediate layer on the second base material side and fixes the second water absorbing material.
including,
The absorber according to any one of claims 1 to 4. The non-woven fabric of the intermediate layer contains pulp fibers.
The absorber according to claim 5. The absorber is located in a region inside the both ends in the width direction of the absorber in a plan view, and a bonding region in which the first base material and the second base material are bonded to each other with an adhesive is formed. Have and
The joint region is located on both sides of the width direction with respect to the longitudinal center line extending in parallel with the longitudinal direction of the absorber through the center in the width direction in the absorber, and is a central portion in the longitudinal direction. Includes a pair of longitudinally joined regions with a slit-like shape that passes through and extends in the longitudinal direction.
In the width direction, the basis weight of the water-absorbent material in the region between the pair of longitudinal joint regions is larger than the basis weight of the water-absorbent material in each outer region of the pair of longitudinal joint regions.
The absorber according to any one of claims 1 to 6.

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