JP2020093091A - Absorbent article - Google Patents

Abstract

To provide an absorbent article capable of improving absorptivity of watery feces and suppressing leakage of solid objects.SOLUTION: An absorbent article to be worn at a crotch of a wearer includes an absorber and a liquid-permeable sheet covering the surface on a wearer's side of the absorber. The absorber has a pulp whose pulp amount is 60 g/mor more and whose size is 500 mm or larger in a longitudinal direction and 100 mm or wider in the width direction. The liquid-permeable sheet has a layered part where a part of the core wrap sheet wrapping the absorber and a top sheet covering the absorber wrapped in the core wrap sheet are layered and whose ventilation resistance of the respective members in the layer part is smaller than 0.0962 kPa.sec/m, and the absorber has an opening that forms recesses in the liquid-permeable sheet by opening toward the liquid-permeable sheet.SELECTED DRAWING: Figure 2

Description

The present invention relates to absorbent articles such as disposable diapers, pads and sanitary napkins.

BACKGROUND ART Conventionally, an absorbent article is provided with an absorbent body extending in the longitudinal direction connecting the abdomen side and the back side of a wearer, as disclosed in Patent Document 1, for example. By this absorber, excreted liquid such as urine and menstrual blood is absorbed. By disposing this absorbent body between the liquid-permeable top sheet and the liquid-impermeable back sheet, the absorbent article absorbs urine excreted in the top sheet by the absorbent body and absorbs it by the absorbent body. Prevents leaked urine with a back sheet.

International Publication No. 2016/114209

By the way, as the liquid-permeable material forming the top sheet, for example, a non-woven fabric is used. Since a non-woven fabric can realize a soft touch, it is suitable as a material for a top sheet that comes into contact with the wearer's skin. However, urine and menstrual blood, as well as stool and watery feces, are excreted from the wearer. Stool is mostly solid, and watery stool is a mixture of solid and liquid. And the absorber of an absorptive article cannot absorb a solid matter. Therefore, when the wearer of the absorbent article excretes stool or watery feces, the absorbent article is replaced.

When exchanging the absorbent article, it is necessary to perform the exchanging work so that the excrement remaining on the top sheet is not dropped from the absorbent article. However, in the case of watery feces, since liquid is mixed with solid matter, it takes time for the liquid to permeate through the top sheet as compared with urine. Therefore, watery feces are more likely to leak when the absorbent article is removed from the wearer, as compared to urine and stool. When watery stools leak out, solid substances that are not absorbed by the absorbent body may leak out together.

Therefore, an object of the present invention is to provide an absorbent article capable of improving the absorbability of watery feces and suppressing the leakage of solid matter.

In order to solve the above problems, in the present invention, the absorber has a pulp amount of 60 g/m ² or more and a pulp having a size of 500 mm or more in the longitudinal direction and 100 mm or more in the width direction. A liquid-permeable sheet covering the side surface, a part of the core wrap sheet that wraps the absorber, and the ventilation resistance of each member in the laminated portion where the top sheet that covers the absorber wrapped in the core wrap sheet is stacked. It is set to be smaller than 0.0962 kPa·sec/m, and the absorber is provided with an opening for forming a recess in the liquid-permeable sheet.

More specifically, the present invention is an absorbent article that is worn on the crotch of a wearer, including an absorber and a liquid-permeable sheet that covers the wearer-side surface of the absorber. A liquid permeable sheet having a pulp amount of 60 g/m ² or more and a size of 500 mm or more in the longitudinal direction and 100 mm or more in the width direction, and the liquid permeable sheet is a part of a core wrap sheet that wraps the absorbent core; It has a laminated part where the top sheet covering the absorber wrapped in the wrap sheet is laminated, and the ventilation resistance of each member in the laminated part is smaller than 0.0962 kPa·sec/m, and the absorber is liquid permeable. The sheet has an opening that forms a recess in the liquid-permeable sheet by opening toward the sheet.

The liquid-permeable sheet has one or more predetermined members between the core wrap sheet and the top sheet, and the ventilation resistance of the laminated portion of the predetermined members is smaller than 0.0962 kPa·sec/m. It may be one.

Further, the absorbent body is a back body located on the back side from a front body region located on the abdomen side of the wearer when the absorbent article is worn by the wearer, via a crotch region located on the inseam. The opening may have a length extending in the region and extend in the longitudinal direction of the absorbent body.

The absorber has a lower-layer absorber and an upper-layer absorber arranged closer to the top sheet than the lower-layer absorber, and the opening is an opening portion of a hole that penetrates the upper-layer absorber in the thickness direction. May be

The opening may be an opening of a hole that penetrates the absorber in the thickness direction.

Further, the liquid-permeable sheet may have a static friction coefficient of 0.59 or more on the surface contacting the wearer.

The absorber has at least two layers, and the wearer side layer may contain a larger amount of particles of SAP, which is a superabsorbent polymer, than the other layers.

The absorber may have two or more layers, and at least one of the layers may be a layer of SAP particles.

With the above-mentioned absorbent article, it is possible to improve the absorbability of watery feces and suppress the leakage of solid matter.

FIG. 1 is a perspective view of a diaper according to an embodiment. FIG. 2 is an exploded perspective view of the diaper. FIG. 3 is a cross-sectional view of the diaper in a non-wearing state when the center in the longitudinal direction is cut along the width direction. FIG. 4 is a cross-sectional view of the mat when the center in the longitudinal direction is cut along the width direction. FIG. 5 is a diagram showing a modified example of the mat. FIG. 6 is a diagram explaining a test method for verifying the absorbability of watery feces. FIG. 7 is a diagram showing types of core wrap sheets of test samples prepared for verification. FIG. 8 is a first diagram showing the test results. FIG. 9 is a first diagram showing the measurement results of ventilation resistance. FIG. 10 is a second diagram showing the measurement results of ventilation resistance. FIG. 11 is a diagram showing the test results of the coefficient of static friction. FIG. 12 is a table showing the results of measuring the feeling of wearing. FIG. 13 is a diagram showing the physical properties of the top sheet and core wrap sheet used for verification of the core. FIG. 14 is a second diagram showing the test results.

Hereinafter, an absorbent article according to an embodiment of the present invention will be described with reference to the drawings. The configurations of the following embodiments are exemplifications, and the present invention is not limited to the configurations of these embodiments.

<Embodiment>
In the present embodiment, a tape-type disposable diaper (an example of an “absorbent article” in the present application, hereinafter simply referred to as “diaper”) faces a front body and a back arranged to face the wearer's abdomen. The direction connecting the rear body arranged in this manner is the longitudinal direction. Inseam that is placed between the front body (one side in the longitudinal direction) and the back body (the other side in the longitudinal direction) (center in the longitudinal direction) in the crotch of the wearer (placed opposite the crotch). The department is located. Further, in a state where the disposable diaper is worn by the wearer (hereinafter, abbreviated as "wearing state"), the side facing the wearer's skin (inside when worn) is the skin surface side, and the side opposite the skin surface side. The (outside when worn) is the non-skin side. Furthermore, the direction connecting the skin surface side and the non-skin surface side is the thickness direction, and the direction orthogonal to both the longitudinal direction and the thickness direction is the width direction. In addition, viewing from the thickness direction is a plan view.

FIG. 1 is a perspective view of the diaper according to the present embodiment. The diaper 1 is a crotch region 1B that is a region corresponding to a crotch region that covers the wearer's pubic region in a worn state, and a front body region 1F that is located on the front side of the crotch region 1B and that corresponds to the wearer's front body. And a rear body region 1R which is located behind the crotch region 1B and corresponds to the rear body of the wearer. Tapes 2L and 2R that can be attached to the front patch 2F provided on the non-skin surface side of the front body region 1F are provided on the left and right edges of the rear body region 1R. Therefore, in the diaper 1, when the front body region 1F is arranged on the wearer's ventral side and the back body region 1R is arranged on the wearer's back side, the tapes 2L, 2R are attached to the front patch 2F. , It is fixed to the wearer's body while surrounding the wearer's abdominal circumference and thighs. Since the diaper 1 is fixed to the wearer's body in such a form, the wearer can walk while wearing the diaper 1.

In the diaper 1, a mat 6 capable of absorbing and holding a liquid is arranged mainly around the crotch region 1B. In addition, in the diaper 1, in order to suppress the formation of a gap serving as a liquid outflow route between the diaper 1 and the wearer's skin, the three-dimensional gathers 3BL, 3BR are provided around the wearer's thigh. Is provided, and the waist gather 3R is provided in a portion surrounding the abdominal circumference of the wearer. The three-dimensional gathers 3BL and 3BR and the waist gather 3R are in close contact with the wearer's skin by the elastic force of the rubber thread. Therefore, the liquid excreted from the pubic area of the wearer is absorbed by the mat 6 of the diaper 1 with almost no leakage from the diaper 1.

FIG. 2 is an exploded perspective view of the diaper 1. Further, FIG. 3 is a cross-sectional view of the diaper 1 in the non-wearing state when the center in the longitudinal direction is cut along the width direction. The diaper 1 has a cover sheet 4 that forms an outer surface in the worn state. The cover sheet 4 is a sheet-like member having a substantially rectangular outer shape in which constrictions 4KL and 4KR are provided in a portion corresponding to the long side, and forms the exterior surface of the diaper 1. The constrictions 4KL and 4KR are provided at positions where the wearer's thighs are located. The cover sheet 4 is provided to reinforce the back sheet 5 and to improve the touch. For example, in order to suppress excrement leakage, a nonwoven fabric made of a liquid-impermeable thermoplastic resin may be used as the material. it can. Examples of the liquid-impermeable thermoplastic resin include polyethylene (PE) and polypropylene (PP). The cover sheet 4 is not limited to a single layer structure and may have a multilayer structure including an inner cover sheet and an outer cover sheet.

The diaper 1 has a back sheet 5, a mat 6, and a top sheet 7 which are sequentially stacked on the skin side surface of the cover sheet 4. The back sheet 5, the mat 6, and the top sheet 7 are sheet-shaped members each having a substantially rectangular appearance, and are sequentially laminated on the cover sheet 4 in a state where the longitudinal direction matches the longitudinal direction of the cover sheet 4. .. Like the cover sheet 4, the back sheet 5 is a sheet formed of a liquid-impermeable thermoplastic resin as a material in order to suppress excrement leakage. The top sheet 7 is a sheet-shaped member that is arranged on the skin side of the wearer so as to cover the water absorbing surface of the mat 6. The top sheet 7 has liquid permeability in part or all. Therefore, in the state where the diaper 1 is worn, the liquid excreted from the wearer enters the mat 6 through the top sheet 7 that can come into contact with the wearer's skin, and is absorbed there. For example, woven cloth, non-woven cloth, and porous film can be used as the material of the top sheet 7. The top sheet 7 may have hydrophilicity.

The backsheet 5, mat 6, and topsheet 7 all extend from the front body region 1F to the back body region 1R. Therefore, when the cover sheet 4 in which the back sheet 5, the mat 6 and the top sheet 7 are laminated covers the pubic area of the wearer, both longitudinal end portions of the back sheet 5, the mat 6 and the top sheet 7 are It is located on the ventral and dorsal sides of the. That is, the wearer's genital area is in a state of being covered with the mat 6 from the wearer's ventral side to the back side. Therefore, even if the wearer excretes the liquid out of the body in any of the postures with the belly down and the back down, the excreted liquid contacts the mat 6 through the top sheet 7. It will be.

Further, the diaper 1 has elongated strip-shaped side sheets 8L and 8R for forming the above-mentioned three-dimensional gathers 3BL and 3BR. The side sheets 8L and 8R are liquid impermeable sheets provided on the long side portions of the top sheet 7. Similar to the three-dimensional gathers 3BL and 3BR of the diaper 1, the side seats 8L and 8R are provided with constrictions 8KL and 8KR at positions where the wearer's thighs are located. Thread rubbers 8EL and 8ER are woven in the side sheets 8L and 8R along the longitudinal direction. Therefore, when the diaper 1 is in the mounted state, that is, when the diaper 1 has a U-shape in a side view, the side sheets 8L and 8R are attracted in the longitudinal direction by the contracting force of the rubber thread 8EL and 8ER. It becomes a three-dimensional gather that rises from the top and prevents the outflow of liquid.

Further, the rubber thread 9ER for forming the above-mentioned waist gather 3R is provided between the back sheet 5 and the top sheet 7 at a position further back than the end portion of the mat 6. The rubber thread 9ER is provided between the back sheet 5 and the top sheet 7 in a direction in which the longitudinal direction that is the stretching direction is the left-right direction of the diaper 1. Therefore, when the tapes 2L and 2R provided on both the left and right sides of the thread rubber 9ER are attached to the front patch 2F on the abdominal side of the wearer, the thread rubber 9ER exerts a contracting force on the diaper 1 for the wearer. The close contact prevents the formation of a gap between the diaper 1 and the wearer's abdominal girth. The cover sheet 4 is also provided with thread rubbers 4SL and 4SR that prevent a gap from being formed between the diaper 1 and the wearer's abdominal circumference along the longitudinal direction. The rubber thread 4SL, 4SR is provided at an appropriate position in an appropriate number determined according to the elastic force (contractile force) required in the diaper 1 in terms of design.

The mat 6 contains water in the spaces between short fibers of cellulosic fibers such as pulp fibers, rayon fibers, or cotton fibers, or short fibers obtained by hydrophilizing synthetic fibers such as polyethylene, polypropylene, or polyethylene terephthalate. It has a structure in which a granular absorbent resin such as SAP (super absorbent polymer: Super Absorbent Polymer), which is a hydrophilic polymer having a crosslinked structure capable of absorbing and holding, is retained. Therefore, in the mat 6, the volume change of the absorbent resin before and after absorbing the liquid is basically performed within the short fiber that holds the absorbent resin in the gap. Therefore, from a bird's eye view of the entire mat 6, it can be said that the expansion coefficient of the thickness of the mat 6 that has absorbed the liquid is not so large as the expansion coefficient of the absorbent resin itself.

The skin-side surface of the mat 6 and the top sheet 7 are formed with elongated recesses 6U extending along the longitudinal centerline of the mat 6. The recess 6U is a portion where the surface of the mat 6 on the skin surface side and the top sheet 7 are recessed. Therefore, the excrement of the wearer is the concave portion 6U.
After being excreted toward or around it, it is absorbed inside the mat 6 and/or adheres to the skin-side surface of the top sheet 7. Details of the recess 6U will be described later.

In addition, the SAP particles of the present embodiment refer to granular resin compositions containing SAP. The term "resin composition containing SAP" as used herein refers to both a composition composed only of SAP and a composition containing SAP as a main component and containing another substance to the extent that it does not adversely affect water absorption. Is a concept that includes. Examples of the “other substance” include an additive (a surface modifier added for the purpose of hydrophobizing the particle surface), an unreacted monomer remaining during the synthesis of SAP, and the like.

By the way, as shown in FIG. 3, the mat 6 of the above-described embodiment has a core 6C (an example of an “absorbent” in the present application) in which SAP is mixed with crushed pulp (so-called “fluff pulp”). It is wrapped with a core wrap sheet 6W. In the diaper 1, the skin-side surface of the core 6C (corresponding to the "wearer-side surface" in the present application) is wrapped in the core wrap sheet 6W and the part of the core wrap sheet 6W that wraps the core 6C. It is covered by a laminated portion in which the top sheet 7 covering the wrapped core 6C is overlapped. Since both the core wrap sheet 6W and the top sheet 7 are liquid-permeable sheets, the laminated portion has liquid permeability. In the laminated portion, one or a plurality of sheets (which is an example of the “predetermined member” in the present application) may be provided between the top sheet 7 and the core wrap sheet 6W. Further, the core 6C may have a single-layer structure or a multi-layer structure having two or more layers. In the latter case, at least one layer is composed of SAP particles. It may be a layer. If such a layer composed of SAP particles is provided, the mat 6 can quickly absorb the water of urine or watery feces discharged from the wearer, and allow time for the water to contact the wearer's skin. It can be suppressed as much as possible. When the core 6C has a total three-layer structure of, for example, two layers composed of crushed pulp and SAP layers arranged between these layers, the SAP layer which is an intermediate layer is arranged above and below. Since it is between layers, the moisture can be diffused by the capillary phenomenon, and since the moisture is absorbed and retained by the SAP in the region, the moisture is absorbed by the core 6C and the moisture flows back to the wearer's skin. It is possible to suppress the contact of water.

In the diaper 1 of the present embodiment, the ventilation resistance of each member in the laminated portion of the core wrap sheet 6W covering the skin side of the core 6C and the top sheet 7 is smaller than 0.0962 kPa·sec/m. Is becoming This ventilation resistance is a value measured by a ventilation tester (KES-F8-AP1) manufactured by Kato Tech Co., Ltd.

FIG. 4 is a cross-sectional view of the mat 6 taken along the width direction at the center in the longitudinal direction. In FIG. 4, in order to facilitate understanding, the mat 6 is illustrated in a state in which the cross section thereof is extended in the thickness direction. As shown in FIG. 4, the core 6C has a multilayer structure. That is, the core 6C has the upper layer core 6CU arranged on the top sheet 7 side and the lower layer core 6CL arranged on the back sheet 5 side. The core wrap sheet 6W is laid around the upper core 6CU and the lower core 6CL so as to wrap the entire upper core 6CU and the lower core 6CL. Therefore, the upper layer portion of the core wrap sheet 6W is arranged between the top sheet 7 and the upper layer core 6CU. Further, the lower layer portion of the core wrap sheet 6W is arranged between the back sheet 5 and the lower layer core 6CL. As the core wrap sheet 6W, for example, thin paper such as tissue paper or non-woven fabric is used. In the diaper 1 according to the present embodiment, by wrapping the entire core 6C with the core wrap sheet 6W, liquid such as urine can be diffused over the entire surface of the core 6C and absorbed by the entire core 6C. Further, in the core 6C, when the liquid such as urine is excreted, the upper layer core 6CU arranged on the side of the top sheet 7 can absorb urine more quickly than the lower layer core 6CL.

For the upper layer core 6CU and the lower layer core 6CL, fluff pulp, SAP particles, hydrophilic sheet and the like obtained by crushing a fiber material such as softwood, or a combination thereof is used. The SAP particles absorb about 100 to 1000 times their own weight of liquid. As the SAP particles, for example, granular particles having a diameter of about 0.1 to 0.5 mm before the liquid is absorbed are used.

The core 6C is provided with an upper layer opening 6KU formed by penetrating the upper layer core 6CU in the thickness direction. The upper layer opening 6KU is formed so as to extend in the longitudinal direction of the upper layer core 6CU. The upper layer opening 6KU is formed substantially in the center of the upper layer core 6CU in the width direction. Further, in plan view, the upper layer opening 6KU has a rectangular shape in which both front and rear ends are formed in an arc shape. The front end of the upper layer opening 6KU is located in the middle of the front body region 1F, and the rear end of the upper layer opening 6KU is located in the front part of the rear body region 1R. Since such an upper layer opening 6KU is formed in the upper layer core 6CU of the core 6C, the skin side surface of the core wrap sheet 6W enclosing the core 6C, that is, the skin side surface of the mat 6 and the top sheet 7 are formed. The above-mentioned concave portion 6U is formed in this area.

Since the recess 6U is formed by the upper opening 6KU provided in the upper core 6CU, the solid content or stool contained in the watery feces excreted by the wearer is entirely or partially contained in the recess 6U. Become. Therefore, leakage of solids and stool from the diaper 1 is suppressed. Further, since such an upper layer opening 6KU is formed in the upper layer core 6CU of the core 6C, the liquid such as urine excreted by the wearer flows through the upper layer opening 6KU and is diffused. Further, liquid such as urine excreted on the upper layer core 6CU can be guided to the lower layer core 6CL via the upper layer opening 6KU. As described above, the diaper 1 according to the present embodiment can absorb and hold the liquid by the core 6C having the upper core 6CU and the lower core 6CL.

Moreover, the diaper 1 has SAP layers 6SL and 6SR arranged between the upper core 6CU and the lower core 6CL. The SAP layers 6SL and 6SR are formed by collecting a plurality of super absorbent polymer (SAP) particles. The SAP layers 6SL and 6SR include a plurality of SAP particles and can absorb and retain the liquid introduced between the upper core 6CU and the lower core 6CL. As shown in FIG. 4, the SAP layer 6SL is arranged on the left side of the upper layer opening 6KU, and the SAP layer 6SR is arranged on the right side of the upper layer opening 6KU. Further, in a plan view of the core 6C viewed from the skin side, the SAP layers 6SL and 6SR are arranged on both sides of the upper layer opening 6KU so as to extend along the longitudinal direction of the upper layer opening 6KU. Further, in a plan view of the core 6C seen from the skin surface side, the SAP layers 6SL and 6SR are formed in a rectangular shape. The SAP layers 6SL and 6SR may be formed in other polygonal shapes or elliptical shapes instead of the rectangular shape in plan view. The diaper 1 can increase the absorption amount of the liquid as a whole by providing the SAP layers 6SL and 6SR.

The SAP layers 6SL and 6SR are formed by dispersing SAP particles on the lower core 6CL. Further, the SAP layers 6SL and 6SR are sandwiched between the upper core 6CU and the lower core 6CL. Therefore, even when the diaper 1 is moved by the action of the wearer, the particles of SAP contained in the SAP layers 6SL and 6SR move below the upper layer opening 6KU or fall out of the lower layer core 6CL. Can be prevented. By providing such SAP layers 6SL and 6SR, moisture spreads between the upper core 6CU and the lower core 6CL by a capillary phenomenon. When the SAP layers 6SL and 6SR absorb water and expand, the effective volume of the upper layer opening 6KU increases, promoting the absorption of the water contained in the excrement into the core 6C and the solid matter into the recess 6U. The storage capacity can be increased. In addition, the water absorption of the SAP layers 6SL and 6SR between the upper core 6CU and the lower core 6CL allows the water to be absorbed and retained at a position far from the wearer's skin, and the reverse flow of the water absorbed in the core 6C. The contact of moisture with the wearer's skin due to is suppressed.

The upper layer opening 6KU may have a polygonal shape or an elliptical shape other than a rectangular shape in a plan view. The mat 6 may further include not only the upper layer opening 6KU provided in the upper layer core 6CU but also the opening provided in the lower layer core 6CL. FIG. 5 is a diagram showing a modified example of the mat. The mat 6 may have a lower layer opening 6KB similar to the upper layer opening 6KU provided in the upper layer core 6CU in the lower layer core 6CL, as shown in FIG. 5, for example. In this case, the upper layer opening 6KU and the lower layer opening 6KB can be regarded as openings of holes penetrating the core 6C in the thickness direction.

The opening forming the recess 6U preferably has a width of the recess 6U of 10 mm or more. This is because if the width of the recess 6U is less than 10 mm, not only the solid content storage space is insufficient, but also the top sheet 7 is unlikely to be recessed in the opening where the width of the recess 6U can be formed only less than 10 mm. Further, the opening forming the recess 6U preferably has a width of the recess 6U of 40 mm or less. This is because if the width of the recess 6U is larger than 40 mm, the amount of urine absorbed decreases. Further, it is preferable that the concave portion 6U exists within a radius of 40 mm from the anus. This is because there is a possibility that feces may not reach the recess 6U if the recess 6U is located at a position more than 40 mm away from the anus. The length of the recess 6U is preferably 100 mm or more. This is because if the length of the recess 6U is less than 100 mm, the size of the recess 6U may be insufficient as a space for containing solids.

<Verification of liquid flow>
FIG. 6 is a diagram explaining a test method for verifying the absorbability of watery feces. In this verification, a mat having a width of 280 mm and a length of 560 mm was used as a test sample corresponding to the mat 6. The mat is equivalent to the modified example shown in FIG. 5, and has a width of 25 mm as an opening corresponding to the upper layer opening 6KU and the lower layer opening 6KB from an assumed position facing the anus in a worn state (upward (dorsal side)). ) Has an opening of 45 mm and an opening of 75 mm on the lower side (abdominal side), the thickness corresponding to the upper core 6CU is 8 mm, and the thickness corresponding to the lower core 6CL is 5 mm. This thickness is the thickness measured when no pressure is applied to the mat. Then, the mat is placed on a slope having an inclination angle of 30 degrees with the longitudinal direction aligned with the vertical direction of the slope, and 50 g of a reagent simulating watery feces is placed at a position 450 mm from the lower end of the mat. I dropped it. The position where the reagent is dropped is an assumed position facing the anus in the worn state. In this verification, the distance (diffusion length) in which the reagent simulating aqueous feces flows on the mat surface and the amount absorbed by the mat were confirmed. In this verification, 50 g of the reagent is completely absorbed by the mat, and the shorter diffusion length is superior.

In this verification, 10 types of test samples were prepared, and the respective absorptivities were compared. The ten types of test samples are obtained by staggering the types of core wrap sheets that wrap the core, and all of the cores have the same core. The core is pulp having a basis weight of 260 g/cm ² that does not contain SAP (width is 280 mm and length is 560 mm). FIG. 7 is a diagram showing types of core wrap sheets of test samples prepared in this verification.

In FIG. 7, among 10 kinds of test samples, those corresponding to the mat 6 of the above-described embodiment are referred to as “Examples 1 to 6”, and those corresponding to the comparative example are referred to as “Comparative Examples 1 to 4”.

In Examples 1 to 3 and Comparative Example 4, a non-woven fabric prepared by an air-through method is used for the core wrap sheet. The air-through type nonwoven fabric is formed by carding (opening) the raw material fibers and then heat-bonding the fibers by hot air treatment. The weight per unit area of the core wrap sheet is 20.0 g/m ² in Examples 1 and 3, 22.0 g/m ² in Example ² , and 21.0 g/m ² in Comparative Example 4.

Moreover, in Examples 4 and 5, the nonwoven fabric produced by the spun bond method was used for the core wrap sheet. The weight per unit area of the core wrap sheet is 18.0 g/m ² in Example 4 and 17.5 g/m ² in Example 5. The spunbond type nonwoven fabric is formed by carding the raw material fibers, entwining the fibers with high pressure water to form a sheet, and drying the sheet.

Moreover, in Comparative Examples 1 to 3 and Example 6, a tissue is used for the core wrap sheet. Basis weight of the tissue paper, Comparative Example 1 is 19.5 g / ^{m 2,} Comparative Example 2 is 16.0 g / ^{m 2,} Comparative Example 3 is 14.0 g / ^{m 2,} Example 6 14 It is 0.0 g/m ² .

The reagent used for this verification was prepared by mixing bentonite in ion-exchanged water and stirring it, and those within 3 days after preparation were used as a simulated product of watery feces. The reagent has a water content of 94% by weight (for example, 1 kg of the reagent is prepared by mixing 940 g of water and 60 g of bentonite).

When the absorbability of watery feces was verified with respect to these 10 types of test samples, Examples 1 to 6 all had better results than Comparative Examples 1 to 4. FIG. 8 is a first diagram showing the test results. What is shown in the column of “diffusion range” in FIG. 8 is a photograph of the surface of the test sample. In addition, what is shown in the column of "diffusion length" in FIG. 8 represents the distance from the position where the reagent has dropped to the position where the reagent has flown on the surface of the mat. Moreover, what is shown in the column of "leakage amount" in FIG. 8 represents the amount of the reagent leaked from the mat. The description of "no leakage" in the column of "leakage amount" in FIG. 8 means that all the reagents have been absorbed by the mat.

As can be seen from FIG. 8, in each of Comparative Examples 1 to 4, the reagent flowed over a distance longer than 450 mm, and the reagent flowed out of the mat. On the other hand, in each of Examples 1 to 6, the reagent remained within 450 mm, and the reagent did not flow out to the outside of the mat. Particularly, in Examples 1 to 3 in which the non-woven fabric prepared by the air-through method was used for the core wrap sheet, the distance through which the reagent flowed was 138 mm or less at the longest. Was confirmed to be extremely high. In addition, Examples 4 and 5 in which the nonwoven fabric produced by the spunbond method was used for the core wrap sheet were also inferior to Examples 1 to 3, but compared to Comparative Examples 1 to 4, the absorbability of watery feces was high. It was confirmed to be high. It was also confirmed that Example 6 using a tissue for the core wrap sheet had remarkably high absorbency of watery feces as in Examples 1 to 3.

The physical properties of each material used as the core wrap sheet in the above test sample were confirmed, and the confirmation results are shown below. It is considered that whether or not the watery feces stay on the surface of the core wrap sheet without flowing out from the mat is largely influenced by the size of the fine openings formed by the material covering the surface of the core. Therefore, in this confirmation, the air permeability (air flow resistance), which is considered to have a direct correlation with the size of the minute opening, was confirmed.

<Air permeability>
In the above verification, the reagent was dropped directly onto the core wrap sheet without disposing the top sheet. However, in the present confirmation, the form closer to the actual use form, that is, the ventilation resistance of each member in the laminated portion of the top sheet and the core wrap sheet was confirmed. However, since the purpose of this confirmation is to compare the difference in airflow resistance between the core wrap sheets of Examples 1 to 6 and Comparative Examples 1 to 4, as the top sheet to be stacked on each core wrap sheet, the same type of nonwoven fabric is used. (KNT20 manufactured by RNP) was used. The ventilation resistance was measured using a ventilation tester (KES-F8-AP1) manufactured by Kato Tech Co., Ltd. FIG. 9 is a first diagram showing the measurement results of ventilation resistance. Further, FIG. 10 is a second diagram showing the measurement results of the ventilation resistance.

As can be seen from FIG. 9, in each of Examples 1 to 6, it was confirmed that the ventilation resistance of each member in the laminated portion was smaller than 0.0962 kPa·sec/m. On the other hand, in Comparative Examples 1 to 3, the ventilation resistance is 0.0962 kPa·sec/m or more. Therefore, if the liquid-permeable sheet covering the skin side of the core has a ventilation resistance of at least 0.0962 kPa·sec/m, watery stool attached to the surface of the top sheet will quickly spread the sheet. It can be seen that the light penetrates through and is absorbed by the absorber. Further, as can be seen from FIG. 9, it is more preferable that the liquid-permeable sheet covering the skin-side surface of the core has a ventilation resistance of at least 0.0352 kPa·sec/m.

Further, as can be seen from FIG. 10, in all the liquid-permeable sheets covering the skin side of the core, SAP leakage does not occur if the ventilation resistance is 0.0050 kPa·sec/m or more. I understand. “SAP leak” in FIG. 10 is a process in which the holes leading to the absorber are closed with tape, the ends are in the longitudinal direction, and the ends are brought together and separated in a manner of clapping three times. It was determined that there was SAP leakage when spilled over the number of grains, and no SAP leakage when spilled under 19 grains. Further, "strength" in FIG. 10 is the result of visually confirming the presence or absence of breakage after being worn by a subject having an appropriate body shape for 5 hours based on the Nisseiren regulation.

From this confirmation result, as in the diaper 1 of the above-described embodiment, the ventilation resistance of each member in the laminated portion of the core wrap sheet and the top sheet that covers the skin-side surface of the absorbent body is 0.0050 to 0.0962 kPa. It is recognized that the absorbent article within the range of sec/m has excellent absorbability when excreted watery feces and has practical strength, as compared with the absorbent article outside this range. ..

As can be seen from the above verification results, in the diaper 1 of the above-described embodiment, the liquid permeable sheets in the laminated portion such as the top sheet 7 and the core wrap sheet 6W interposed between the wearer and the core 6C are Since the ventilation resistance is less than 0.0962 kPa·sec/m, moisture can be quickly transferred from the wearer to the core 6C.

In addition, although the tape-type disposable diaper was illustrated in the said embodiment, it is applicable also to the absorbent article of other forms. Examples of such absorbent articles include various types of absorbent articles with gathers such as pants-type disposable diapers, urine pads, and light incontinence pads, and flat absorbent articles without gathers.

<Coefficient of static friction>
By the way, since the coefficient of static friction on the surface of the top sheet was also confirmed, the confirmation result will be described. The static friction coefficient was measured using a surface property measuring device (Tribogear TYPE: 14DR) manufactured by Shinto Scientific Co., Ltd. In this confirmation, in order to verify the influence of the coefficient of static friction on the surface of the top sheet on the absorbability of aqueous feces, the static friction of Example 1 in which the absorption of aqueous feces was confirmed to be the highest in the above verification A plurality of types of topsheets having different coefficients were stacked, and the above-described liquid flow was verified in that state. FIG. 11 is a diagram showing the test results of the coefficient of static friction.

Materials of the top sheet of the specimen shown in FIG. 11, in order from the left, non-woven fabric was prepared by the spunbond method: basis weight 16.0 g / ^{m 2,} was prepared by the spun bond method nonwoven basis weight: 18.0 g ^{/ m} 2, created in basis weight 22.0 g / ^{m 2,} an air-through method: the span nonwoven created by bonding method: basis weight 20.0 g / ^{m 2,} a nonwoven fabric was prepared by air-through method: basis weight 25.0 g / ^{m 2,} a nonwoven fabric was prepared by air-through method nonwoven basis weight: 20.0 g / ^{m 2,} a nonwoven fabric was prepared by air-through method: basis weight 18.0 g / ^{m 2,} a nonwoven fabric was prepared by air-through method: a basis weight 16.0 g / ^{m 2.}

As can be seen from FIG. 11, in all of the topsheets having a coefficient of static friction of 0.59 or more, the reagent remained within 450 mm and the reagent did not flow out to the outside of the mat. On the other hand, when the coefficient of static friction on the surface of the top sheet was 0.34 or less, the reagent flowed over a distance longer than 450 mm and the reagent flowed out of the mat. From this, when the coefficient of static friction of the topsheet surface is 0.59 or more, the absorbency when excreted watery water is higher than that of the absorbent article having the coefficient of static friction of less than 0.59. Recognized as excellent. Therefore, if the diaper 1 has a static friction coefficient of 0.59 or more on the surface of the top sheet, excrement leaks when the diaper 1 is removed from the wearer due to the improved absorbability of watery feces. It is possible to suppress the possibility as much as possible.

The relationship between the coefficient of static friction on the surface of the topsheet and the feeling of wearing was measured, and the results are shown below. FIG. 12 is a table showing the results of measuring the feeling of wearing. Regarding the measurement of the feeling of wearing, by 20 panelists, about the lack of discomfort during wearing, an investigation was conducted by selecting "no discomfort" or "there is discomfort", and evaluated according to the following criteria, ◎ and ○ were passed.
◎: "No discomfort" was 16 or more and 20 or less ○: "No discomfort" was 11 or more and 15 or less △: "No discomfort" was 6 or more and 10 or less When x: When "no discomfort" is 0 or more and 5 or less

As shown in the measurement results of FIG. 12, the top sheet having a surface static friction coefficient of less than 2.52 is good, more preferably 1.91 or less, and further preferably 0.98 or less. It was confirmed.

From the results of confirmation of such static friction coefficient, the diaper 1 of the above-described embodiment may have any static friction coefficient on the topsheet surface, but more preferably, the static friction coefficient on the topsheet surface is 0. It can be said that it is 59 or more. Further, it can be said that it is more preferable that the coefficient of static friction of the surface is smaller than 2.52.

In addition, since the verification of the core conditions was performed, the results are shown below. In the above verification, the core was pulp with a basis weight of 260 g/cm ² that does not contain SAP (horizontal width 280 mm and length 560 mm). Therefore, in the present verification, multiple samples having different basis weights were prepared, The absorbability of watery feces in each core was verified. FIG. 13 is a diagram showing the physical properties of the top sheet and core wrap sheet used for verification of the core. In this verification, the top sheet and the core wrap sheet having the physical properties shown in FIG. 13 were superposed on four types of cores having different amounts of pulp per unit area, and the liquid flow was verified in that state. FIG. 14 is a second diagram showing the test results.

Each core of the specimen shown in FIG. 14, the pulp amount per unit area is formed by ^{40g / m 2, 50g / m} 2, 60g / m 2, 70g / m 2 of pulp from left to right. As can be seen from FIG. 14, in any of those having a core pulp amount of 60 g/m ² or more, the reagent remained within 450 mm in the longitudinal direction, and the reagent did not flow out to the outside of the mat. On the other hand, when the amount of pulp in the core was less than 60 g/m ² , the reagent flowed over a distance longer than 450 mm in the longitudinal direction, and the reagent flowed out of the mat. Further, in all four types, the reagents remained within 100 mm in the width direction. From this, it is recognized that when the pulp amount of the core is at least 60 g/m ² or more, excellent absorbability is exhibited when excretion of watery feces. If the core has a length of at least 500 mm or more in the longitudinal direction and a length of at least 100 mm or more in the width direction, excreted aqueous feces should not flow out of the mat. Is recognized. The length in the width direction may be 150 mm or more, and more preferably 200 mm or more in consideration of positional deviation in the width direction when worn, individual differences in the size of the buttocks of the wearer, and the like. In order to prevent the stool absorbed in the mat from coming into contact with the skin due to the gap formed between the tops of the left and right buttocks, it is effective to lengthen the width direction in this way. For example, the core may exist up to the left and right ends of the crotch region 1B of the diaper 1.

From the above verification results, the core 6C is formed of pulp having a pulp amount of 60 g/m ² or more and a length of 500 mm or more and a width of 100 mm or more, and the static friction of the surface of the top sheet 7 If the diaper 1 has a coefficient of 0.59 or more and the ventilation resistance of each member in the laminated portion where the core wrap sheet 6W and the top sheet 7 overlap is less than 0.0962 kPa·sec/m, absorbency of watery feces Is recognized to improve. Such an effect of improving the absorbability of watery feces is obtained by the moisture permeability in the laminated portion where the core wrap sheet 6W and the top sheet 7 are overlapped with each other, and the absorption performance of the watery feces in the core 6C below the laminated portion. This is due to the synergistic effect with.

1・・Diaper 1B・・Inseam area 1F・・Front body area 1R・・Back body area 2F・・Front patch 2L, 2R・・Tape 3BL, 3BR・・Three-dimensional gather 3R・・West gather 4・・Cover sheet 4KL , 4KR ··· Constriction 5 ··Backsheet 6 ··Mat 6U ··Concave 6C ··Core 6CU ··Upper core 6CL ··Lower core 6KU ··Upper opening 6KB ··Lower opening 6SL · ·SAP layer 6SR・・SAP layer 6W ・・Core wrap sheet 7 ・・Top sheet 8 ・・Side sheets 8KL, 8KR ・・Tightening 4SL, 4SR, 8EL, 8ER, 9ER ・・ Thread rubber

Claims (8)

An absorbent article to be worn on the crotch of a wearer,
An absorber,
A liquid-permeable sheet covering the surface of the absorber on the wearer side,
The absorbent body has a pulp amount of 60 g/m ² or more and a size of 500 mm or more in the longitudinal direction and 100 mm or more in the width direction,
The liquid-permeable sheet has a laminated portion in which a part of a core wrap sheet that wraps the absorbent body and a top sheet that covers the absorbent body that is wrapped in the core wrap sheet are stacked. The ventilation resistance of each member in the part is smaller than 0.0962 kPa·sec/m,
The absorber has an opening that forms a recess in the liquid-permeable sheet by opening toward the liquid-permeable sheet.
Absorbent article. The liquid-permeable sheet has one or a plurality of predetermined members between the core wrap sheet and the top sheet, and the ventilation resistance of the laminated portion of the predetermined members is 0.0962 kPa·sec/m or more. small,
The absorbent article according to claim 1. The absorbent body includes a front body region located on the abdomen side of the wearer in a state where the absorbent article is worn by the wearer, a rear body region located on the back side through a crotch region located in the crotch region. Has a length extending into the region,
The opening extends in the longitudinal direction of the absorber,
The absorbent article according to claim 1 or 2. The absorbent body has a lower layer absorbent body and an upper layer absorbent body arranged on the topsheet side with respect to the lower layer absorbent body,
The opening is an opening portion of a hole that penetrates the upper absorbent body in a thickness direction,
The absorbent article according to any one of claims 1 to 3. The opening is an opening of a hole that penetrates the absorber in the thickness direction,
The absorbent article according to any one of claims 1 to 3. The liquid-permeable sheet has a coefficient of static friction of 0.59 or more on the surface contacting the wearer,
The absorbent article according to any one of claims 1 to 5. The absorbent body has at least two layers, and the wearer side layer contains more particles of SAP, which is a superabsorbent polymer, than other layers.
The absorbent article according to any one of claims 1 to 6. The absorber has two or more layers, at least one of which is a layer of SAP particles,
The absorbent article according to any one of claims 1 to 7.

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