JP6960219B2 - Absorbent article - Google Patents

Description

The present invention relates to an absorbent article comprising an absorbent core and a sheet covering the absorbent core.

As an absorbent article such as a disposable diaper, a liquid-permeable front sheet forming a skin-facing surface, a liquid-impermeable back sheet forming a non-skin facing surface, and an absorbent body arranged between both sheets are provided. It is known that the absorbent body is composed of an absorbent core containing an absorbent material such as wood pulp or a water-absorbent polymer, and a core wrap sheet that covers the outer surface of the absorbent core. The core wrap sheet functions as a sheet for receiving the absorbent material at the time of manufacturing the absorbent body, and plays a role of wrapping and shaping the absorbent core after manufacturing. Conventionally, a water-permeable sheet such as thin paper, absorbent paper, or non-woven fabric has been used as the core wrap sheet. The absorbent core and the core wrap sheet are usually bonded to each other via an adhesive.

Conventionally, there is a problem that the shape of the absorbent core is deformed when the absorbent article is worn. If the absorbent core is worn with the shape of the absorbent core deformed, the part of the absorbent article corresponding to the wearer's crotch may be irregularly deformed to hinder the wearer's walking. In addition, there is a risk of leaking excrement such as urine and reducing the wearing feeling. As a technique capable of suppressing such deformation of the absorbent core, a through hole is formed in the absorbent core, and the core wrap sheets on the skin facing surface side and the non-skin facing surface side of the absorbent core penetrate each other. Techniques for joining to each other at holes are known, but such techniques have a problem of causing a decrease in the absorption capacity of the absorbent core due to a decrease in the absorbent material accompanying the formation of the through holes. Further, as another technique capable of suppressing the shape collapse of the absorbent core, a technique of embossing the absorbent core is known, but such a technique causes hardening of the absorbent core and reduces the wearing feeling. May cause new problems.

In Patent Document 1, as an absorbent article capable of effectively suppressing the shape collapse of the absorbent core, an adhesive for joining a core wrap sheet is vertically provided on each of the skin-facing surface and the non-skin-facing surface of the absorbent core. The linear adhesive adhesive portion extending in the direction (the direction corresponding to the front-back direction of the wearer) is intermittently arranged in the horizontal direction (the direction orthogonal to the vertical direction) and adheres so as to form a striped pattern. Moreover, the center line extending in the vertical direction by dividing each adhesive adhesion portion into two in the horizontal direction does not overlap with the skin-facing surface and the non-skin-facing surface of the absorbent core, and the skin-facing surface of the absorbent core is better. An absorbent article is described in which the number of adhesive-attached portions is smaller than that of the non-skin facing surface.

Further, Patent Document 2 describes that the skin-facing surface of the absorbent core is made lower than the non-skin-facing surface with respect to the coating area ratio of the adhesive for joining the core wrap sheet. According to Patent Document 2, due to such a configuration, the degree of swelling when the absorbent core absorbs excrement is larger on the skin-facing surface side than on the non-skin-facing surface side, so that the wearer's skin It is said that a gap is created between the surface sheet and the surface sheet to improve air permeability. In Patent Documents 1 and 2, the number of adhesion portions or the coating area ratio of the adhesive for joining the core wrap sheet is different from each other between the skin-facing surface and the non-skin-facing surface of the absorbent core. Yes, they are uniform on each of the skin-facing or non-skin-facing surfaces of the absorbent core.

In Patent Document 3, in an absorbent article including an absorbent core having a constricted portion in the crotch portion and a core wrap sheet covering the absorbent core, a core wrap sheet is defined at a position where the constricted portion is formed. It is described that the space portion is formed and the absorbent core and the core wrap sheet that define the space portion are not coated with the adhesive for joining the core wrap sheet. According to the absorbent article described in Patent Document 3, the space portion functions as a swelling allowance when the absorbent core absorbs excrement and swells, so that the swelling of the absorbent core due to liquid absorption is a core wrap sheet. It is said that the inconvenience hindered by the above can be avoided and the leakage resistance can be improved.

Japanese Unexamined Patent Publication No. 2014-100307 Japanese Unexamined Patent Publication No. 2013-255560 Japanese Unexamined Patent Publication No. 2013-99451

The shape of the absorbent core is more likely to collapse when the absorbent article is worn at both ends in the lateral direction than at the central portion in the lateral direction of the absorbent core. The reason is that the lateral ends of the absorbent core are parts that are particularly susceptible to pressure from the wearer's thighs when wearing the absorbent article, and therefore distortion due to the load caused by such body pressure. This is because the stress generated by the friction with the wearer's skin is likely to be applied. Further, in the absorbent core, the excrement is usually directly absorbed in the lateral central portion of the crotch part, and the absorbed excrement diffuses in the plane direction. Therefore, the lateral central portion and both ends of the absorbent core. There is a difference in rigidity due to the difference in the amount of excrement absorbed between the parts, and the boundary between both parts and its vicinity becomes a rigidity change part (absorbent core Dry-Wet interface). The occurrence of changes is also one of the causes in which both ends of the absorbent core in the lateral direction are particularly liable to lose their shape. No technique has yet been provided that can effectively prevent the shape of both ends of the absorbent core from collapsing in the lateral direction.

Therefore, an object of the present invention is to provide an absorbent article which is excellent in shape retention of the absorbent core when worn and has good and stable excrement absorption performance and wearing feeling.

The present invention has a longitudinal direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction orthogonal to the longitudinal direction, and a liquid-retaining absorbent core and a core covering the absorbent core. An absorbent article provided with a wrap sheet, wherein an adhesive adheres to at least one of a skin-facing surface and a non-skin-facing surface of the absorbent core, and the core adheres to the adhesive-adhesive surface via the adhesive. The wrap sheet is joined, and the adhesive is attached to the adhesive at the lateral ends of the absorbent core, which are located at both ends of the absorbent core in the lateral direction, with respect to the adhesive area ratio of the adhesive on the adhesive adhesive surface of the absorbent core. It is an absorbent article having a magnitude relationship in which the adhesion area ratio is larger than the adhesion area ratio of the adhesive in the central portion in the lateral direction of the core sandwiched between both ends in the lateral direction of the core.

According to the present invention, there is provided an absorbent article which is excellent in shape retention of the absorbent core when worn, is less likely to lose its shape when worn, and has good and stable excrement absorption performance and wearing feeling. NS.

FIG. 1 is a plan view schematically showing a skin-facing surface, that is, a surface sheet side of a deployable disposable diaper according to an embodiment of the absorbent article of the present invention, and the elastic members of each part are stretched and expanded in a plane shape. It is a plan view in the unfolded state. FIG. 2 is a cross-sectional view schematically showing the cross section taken along line I-I of FIG. FIG. 3 is an explanatory view of the adhesion portion of the adhesive for joining the core wrap sheet in the diaper shown in FIG. It is a plan view shown in.

Hereinafter, the absorbent article of the present invention will be described with reference to the drawings based on an example of a deployable disposable diaper which is a preferred embodiment thereof. 1 and 2 show the deployable disposable diaper 1 of the present embodiment. The diaper 1 has a vertical direction X extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction Y orthogonal to the vertical direction X, and the ventral side portion A and the dorsal portion arranged on the ventral side of the wearer. It has a dorsal portion C arranged on the side and a crotch portion B located between them. The ventral portion A, the inseam B, and the dorsal portion C correspond to each region when the diaper 1 is divided into three equal parts in the vertical direction X. The inseam B has an excretion portion facing portion that is arranged to face the excretion portion of the wearer's penis, anus, etc. when the diaper 1 is worn, and the excretion portion facing portion is usually in the vertical direction X of the diaper 1. It is located in or near the center.

As shown in FIGS. 1 and 2, the diaper 1 is arranged on the skin facing surface side of the absorbent body 4 having the absorbent core 40 and the absorbent body 4, and is located closer to the wearer's skin than the absorbent body 4. A liquid-permeable surface sheet 2 that can come into contact with the wearer's skin when worn, and a liquid diaper that is arranged on the non-skin facing surface side of the absorber 4 and is located farther from the wearer's skin than the absorber 4. It is provided with a permeable or water-repellent back surface sheet 3, and in a plan view as shown in FIG. 1, the central portion of the vertical direction X located at the lower crotch B is constricted inward and is long in one direction, that is, the vertical direction X. It has a vertically long hourglass shape. The front surface sheet 2 and the back surface sheet 3 each have a size larger than that of the absorber 4 interposed between the two sheets 2 and 3, and form the outer shape of the unfolded and stretched diaper 1 as shown in FIG. ing.

In the present specification, the "skin facing surface" is a surface of the absorbent article or its constituent members (for example, the absorbent core 40) that is directed toward the skin side of the wearer when the absorbent article is worn, that is, relatively. The side close to the wearer's skin, and the "non-skin facing surface" is the surface of the absorbent article or its constituent members that faces the opposite side (clothing side) of the absorbent article when the absorbent article is worn, that is, relative to the skin. It is the side far from the wearer's skin. The term "when worn" as used herein means a state in which the normal proper wearing position is maintained, and does not include the case where the absorbent article is deviated from the proper wearing position.

In the diaper 1, as shown in FIGS. 1 and 2, a liquid-permeable sub sheet between the surface sheet 2 and the absorber 4 (skin-side core wrap sheet 41), which is also called a second sheet in the present technical field, is used. Layer 5 is arranged. The sub-layer 5, together with the surface sheet 2, constitutes a "surface layer arranged at a position closer to the wearer's skin than the absorber 4," and the surface layers are the sub-layer 5 and the surface in the order closer to the absorber 4. Includes sheet 2. The sublayer 5 covers substantially the entire area of the absorber 4 facing the skin.

The sublayer 5 plays a role of improving the permeability of the liquid from the surface sheet 2 to the absorber 4, reducing the return of the liquid absorbed by the absorber 4 to the surface sheet 2, and the absorbent core 40. It can also contribute to the suppression of the shape collapse of. This is because the rigidity of the entire absorber 4 is improved by the presence of the sublayer 5. From the viewpoint of ensuring that the action and effect of the sublayer 5 is more reliably achieved, the basis weight of the sublayer 5 is preferably 15 g / m ² , more preferably 20 g / m ² or more, and preferably 60 g. / M ² or less, more preferably 50 g / m ² or less. The sublayer 5 may be a hydrophilic and liquid permeable sheet, and examples thereof include paper, woven fabric, and non-woven fabric, but the non-woven fabric is particularly preferable because it has relatively high strength and excellent flexibility. Examples of the non-woven fabric forming the sublayer 5 include an air-through non-woven fabric, a point-bonded non-woven fabric, a resin-bonded non-woven fabric, a spunlace non-woven fabric, and an air-laid non-woven fabric.

A thread-like elastic member 11 is extended along the lateral direction Y between the waist portion of each of the ventral side portion A and the dorsal side portion C, that is, the front surface sheet 2 and the back surface sheet 3 at the end portion in the vertical direction X. It is fixed, so that waist gathers are formed on the waist portion when the diaper 1 is worn due to the contraction of the elastic member 11. Further, side sheets 6 are arranged on the left and right sides of the diaper 1 on the surface sheet 2 side along the vertical direction X, respectively. The side sheet 6 has an inner edge portion along the vertical direction X and an outer edge portion located outside the inner edge portion in the horizontal direction Y and along the vertical direction X, and has a plane as shown in FIG. Visually, the inner edge portion overlaps with the absorber 4, and the outer edge portion extends outward in the lateral direction Y from the side edge of the absorber 4 along the vertical direction X and is joined to the back surface sheet 3. A thread-like elastic member 12 is fixed in an extended state along the vertical direction X between the side seat 6 and the back seat 3 in the left and right leg portions arranged around the wearer's legs. A pair of leg gathers are formed on the leg portion when the diaper 1 is worn due to the contraction of the elastic member 12. Further, a thread-like elastic member 13 is fixed to the inner edge of the side seat 6 in an extended state along the vertical direction X, whereby at least the inseam B is caused by the contraction of the elastic member 13 when the diaper 1 is worn. In, the side sheet 6 stands up toward the wearer's skin side from the joint with another member, and a leak-proof cuff is formed. The front surface sheet 2, the back surface sheet 3, the absorber 4, the side sheets 6, and the elastic members 11 to 13 are joined to each other by a known joining means such as a hot melt type adhesive.

As shown in FIG. 1, a pair of fastening tapes 7 and 7 are provided on both side edges of the dorsal portion C of the diaper 1 along the vertical direction X. A fastening portion 71 made of a male member of a mechanical hook-and-loop fastener is attached to the fastening tape 7. Further, a landing region 8 made of a female member of a mechanical hook-and-loop fastener is formed on the non-skin facing surface of the ventral side A of the diaper 1. In the landing region 8, a female member of a mechanical hook-and-loop fastener is attached to the non-skin facing surface of the back surface sheet 3 forming the non-skin facing surface of the ventral side A by a known joining means such as an adhesive or a heat seal. It is formed by joining and fixing, and the fastening portion 71 of the fastening tape 7 can be detachably fastened.

As the surface sheet 2, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation, and it is assumed that the surface sheet 2 is a liquid permeable sheet capable of permeating body fluids such as urine and feces. As the material, a woven fabric made of synthetic fibers or natural fibers, a non-woven fabric, a porous sheet, or the like can be used. As an example of the surface sheet 2, a non-woven fabric made of a natural fiber such as cotton or a non-woven fabric made of various synthetic fibers subjected to a hydrophilic treatment can be used. For example, a core-sheath structure type (including side-by-side type) composite fiber using polypropylene or polyester as a core component and polyethylene as a sheath component is made into a web by carding, and then a non-woven fabric (after that, a hole is opened at a predetermined position) by an air-through method. Treatment may be applied). Further, from the viewpoint of high liquid permeability (dry feeling), a perforated sheet made of polyolefin such as low-density polyethylene can also be preferably used.
As the back sheet 3, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation, and liquid impermeable (including water repellency) and moisture permeable ones are preferable. Used. Specifically, in order to obtain sufficient water permeability, a film made of a synthetic resin such as polyethylene in which fine powder composed of a filler such as calcium carbonate is dispersed is stretched, and a porous film having fine pores is a back sheet. Can be suitably used as 3.
As the side sheet 6, a sheet that can be used as the back sheet 3 can be used.

The absorber 4 includes a liquid-retaining absorbent core 40, a skin-side core wrap sheet 41 that covers the skin-facing surface of the absorbent core 40, and a non-skin-side core that covers the non-skin facing surface of the absorbent core 40. It is configured to include a wrap sheet 42. In a plan view as shown in FIG. 1, the absorber 4 (absorbent core 40) has an hourglass-like shape in which the central portion of the vertical direction X located at the lower part of the crotch B is constricted inward and has a vertically long shape that is long in the vertical direction X. have.

The absorbent core 40 is mainly composed of an absorbent material, and the content of the absorbent material in the absorbent core 40 is usually about 100% by mass. As the absorbent material, various materials conventionally used for absorbent articles such as disposable diapers can be used without particular limitation. For example, hydrophilic fibers such as wood pulp and synthetic fibers treated with a hydrophilizing agent. And water-absorbent polymer particles. Examples of the structure of the absorbent core 40 include a structure of hydrophilic fiber slabs, a structure in which water-absorbent polymer particles are supported on the slab, or a structure consisting of only water-absorbent polymer particles.

In the present embodiment, as shown in FIG. 2, the skin-side core wrap sheet 41 and the non-skin-side core wrap sheet 42 form one continuous core wrap sheet. More specifically, in the present embodiment, one continuous core wrap sheet having a width of 2 times or more and 3 times or less the length of the lateral Y of the absorbent core 40 is adopted. As shown in FIG. 2, the core wrap sheet covers the entire surface of the absorbent core 40 facing the skin, and extends outward in the horizontal direction Y from both side edges of the absorbent core 40 along the vertical direction X. A protruding portion thereof is wound below the absorbent core 40 to cover the entire non-skin facing surface of the absorbent core 40. Then, in this one core wrap sheet, the portion covering the skin facing surface of the absorbent core 40 is the skin side core wrap sheet 41, and the portion covering the non-skin facing surface of the absorbent core 40 is the non-skin side core wrap. Sheet 42. In the present embodiment, the skin-side core wrap sheet 41 and the non-skin-side core wrap sheet 42 are the same as the sheets. The basis weight of the core wrap sheets 41 and 42 is preferably 5 g / m ² or more, more preferably 10 g / m ² or more, and preferably 40 g / m ² or less, still more preferably 30 g / m ² or less.

In the present embodiment, as shown in FIG. 2, the adhesive 9 is attached to both the skin-facing surface and the non-skin-facing surface of the absorbent core 40, and the absorbent is one of the adhesive-adhering surfaces. The skin-side core wrap sheet 41 is bonded to the skin-facing surface of the core 40 via an adhesive 9, and the adhesive 9 is attached to the non-skin-facing surface of the absorbent core 40, which is one of the adhesive-attached surfaces. The non-skin side core wrap sheet 42 is bonded to the core wrap sheet 42. On each of the skin-facing surface and the non-skin-facing surface of the absorbent core 40, the adhesive 9 does not adhere to the entire surface of the surface without gaps (so-called solid coating is not applied), and is not attached to the adhesive portion 9. It adheres intermittently in a pattern in which the adhesive portion is mixed. The plan view shape of the adhesive 9 (coating pattern of the adhesive 9) is not particularly limited, and examples thereof include a linear or spiral shape extending in the vertical direction X and an Ω (omega) shape long in the vertical direction X. .. As the adhesive 9, those usually used for joining members in this type of absorbent article, such as a hot melt type adhesive, can be used without particular limitation.

FIG. 3 shows a main part of the unfolded and stretched diaper 1 on the skin-facing surface side (surface sheet 2 side) as a diagram for explaining the adhered portion of the adhesive 9. One of the main features of the diaper 1 is the adhesion surface of the adhesive 9 on the absorbent core 40, specifically, the adhesive area of the adhesive 9 on at least one of the skin-facing surface and the non-skin-facing surface of the absorbent core 40. Regarding the ratio, the core lateral end portions 40S located at both ends of the absorbent core 40 in the lateral direction Y are larger than the core lateral central portion 40M sandwiched between the core lateral end portions 40S and 40S. (Adhesive area ratio of the adhesive 9 at the lateral end portion 40S of the core> Adhesive area ratio of the adhesive 9 at the central portion 40M in the core lateral direction), and a magnitude relationship is established. The adhesive area ratio of the adhesive is measured by the following method.

<Measurement method of adhesive area ratio>
A colored toner such as black (manufactured by Brother Industries, Ltd., trade name "Refillable toner powder bottle for laser printer 560971") is sprayed on the adhesive-adhering surface of the measurement target (core wrap sheet), and the adhesive-adhering surface is sprayed. The adhered adhesive is colored, and the colored measurement target is cut into a predetermined size to prepare a measurement sample. Then, the total area of the colored portion (adhesive adhering portion) in the measurement sample is measured. The total area of the colored portion is measured by imaging the toner spraying surface in the measurement sample by a known method, further binarizing the image data, and performing the measurement based on the binarized data. From the total area of the colored portion thus obtained, the adhesive area ratio is calculated by the following formula. For one measurement target, the adhesive area ratio is obtained at any three or more points by the above procedure, and the average value thereof is used as the adhesive adhesion area ratio in the measurement target.
Adhesive area ratio (%) = (total area of colored part / area of measurement sample) x 100

When the constituent member (for example, a core wrap sheet) is taken out from the absorbent article and evaluated and measured, if the constituent member is fixed to another constituent member by an adhesive, fusion, or the like, the constituent member is not included. The fixed part is removed by applying a solvent or blowing hot air with a dryer before taking it out.

As described above, the core laterally end portions 40S and 40S located at both ends in the lateral direction of the absorbent core 40 are portions that are particularly susceptible to pressure by the wearer's thighs and the like when the diaper 1 is worn, and thus absorb the diaper 1. The shape of the sex core 40 is more likely to collapse at the core lateral end portion 40S than at the core lateral central portion 40M. On the other hand, the shape collapse of the absorbent core 40 is suppressed as the number of joints with the core wrap sheets 41 and 42 covering the absorbent core 40 by the adhesive 9 increases. Therefore, in the diaper 1, regarding the adhesion area ratio of the adhesive 9 that joins the absorbent core 40 and the core wrap sheets 41 and 42, the adhesive surface (the skin-facing surface or the non-skin surface of the absorbent core 40). On the facing surface), the magnitude relationship of "adhesive area ratio of the adhesive 9 at the lateral end portion 40S of the core> adhesive area ratio of the adhesive 9 at the central portion 40M of the core lateral direction" is established. As a result, the strength and shape retention of both ends 40S and 40S in the lateral direction of the core are improved. As a result, excellent absorption performance and wearing feeling can be stably exhibited for a long period of time.

Further, from the viewpoint of preventing the shape of the absorbent core 40 from collapsing, it is effective to increase the adhesion area ratio of the adhesive 9 not only at both ends 40S and 40S in the lateral direction of the core but also at the central portion 40M in the lateral direction of the core. Although it is considered that there is, increasing the adhesion area ratio of the adhesive 9 in the central portion 40M in the lateral direction of the core may cause another problem. That is, when the diaper 1 is worn, it is desirable that the absorber 4 flexibly deforms along the outer shape of the crotch portion of the wearer, but the adhesion area ratio of the adhesive 9 in the central portion 40M in the lateral direction of the core is high. If it is too much, the flexibility and flexibility of the absorber 4 will be significantly reduced, and it will be difficult for the absorber 4 to be deformed to fit the wearer's body shape, which is inconvenient such as deterioration of absorption performance and wearing feeling. May lead to. In consideration of these points, in the diaper 1, the adhesive area ratio of the adhesive 9 is selectively increased with respect to both ends 40S and 40S in the lateral direction of the core, which are the parts where the shape of the absorbent core 40 is particularly likely to collapse. , The adhesion area ratio of the adhesive 9 in the central portion 40M in the lateral direction of the core, which is the region sandwiched between them, is not increased.

The core lateral central portion 40M and the core lateral end portion 40S are specifically defined as follows. That is, with reference to FIG. 3, in the absorbent core 40, the length in the lateral direction Y, that is, the narrowest portion (constricted portion) 43 in the lateral direction, which is the portion having the minimum width, is located at both ends 431 and 431 in the lateral direction in the lateral direction Y. Two virtual straight lines VL, extending inward in the vertical direction X through positions separated by a distance corresponding to 10% of the width of the core narrowest portion 43 (that is, the length between both ends 431 and 431 in the horizontal direction). The portion of the absorbent core 40 sandwiched between the two virtual straight lines VL and VL with the VL as a boundary is the core lateral central portion 40M. The central portion 40M in the lateral direction of the core has a band shape (rectangular shape) extending in the vertical direction X in a plan view as shown in FIG. Further, the portion of the absorbent core 40 located outside the two virtual straight lines VL and VL in the lateral direction Y is the core lateral end portion 40S.

In order to improve the adhesive area ratio, it is necessary to increase the area of the adhesive adhering portion on the adhesive adhering target (skin facing surface or non-skin facing surface of the absorbent core or the core wrap sheet). Even if the amount of adhesive per adhesive adhesive portion is relatively large, the adhesive area ratio does not improve if the total area (number) of the adhesive adhesive portions is relatively small. As a specific method for establishing the magnitude relationship of the adhesive area ratio of the adhesive 9, for example, the number of adhesive means (for example, a nozzle for ejecting the adhesive) of the adhesive 9 is set in the central portion in the lateral direction of the core. A method of differentiating between 40M and the core lateral end 40S can be exemplified. In this case, the number of adhesive means for adhering the adhesive 9 may be relatively small for the central portion 40M in the lateral direction of the core and relatively large for the end portion 40S in the lateral direction of the core. The direct adhesion target of the adhesive may be either one of the absorbent core and the core wrap sheet, or both. As the means for adhering the adhesive 9, known means can be used without particular limitation.

For example, with reference to FIG. 3, the skin-side core wrap sheet 41 is located on the non-skin facing surface (facing surface with the absorbent core 40) outside the two virtual straight lines VL and VL in the lateral direction Y. The adhesive 9 may be applied to the entire area of the portion. In that case, the extension extending outward in the lateral direction Y from the lateral end of the absorbent core 40 (such as the lateral end 431 of the core narrowest portion 43) on the non-skin facing surface of the skin-side core wrap sheet 41. The adhesive 9 is also applied to the protruding portion 410, that is, the portion that does not directly contribute to the bonding with the absorbent core 40, but there is no particular problem. Rather, by applying the adhesive 9 to the extending portion 410 of the skin-side core wrap sheet 41, the shape of the absorbent core 40 can be prevented from being deformed more effectively. That is, when the adhesive 9 is applied to the extending portion 410 of the skin-side core wrap sheet 41 located on the outer side of the core narrowest portion 43 in the lateral direction Y, the adhesive 9 faces the extending portion 410. Since the extending portion (not shown) of the non-skin side core wrap sheet 42 is joined to each other via the adhesive 9, the core is maximized by the movement of the wearer's leg when wearing the diaper 1. Even if relatively large strains or frictions are applied to both ends 431, 431 in the lateral direction of the narrow portion 43, the shape of the narrowest core portion 43 and its vicinity is maintained, and as a result, excellent absorption performance and wearing comfort are long. It becomes possible to express stably over time.

Further, in the diaper 1, as shown in FIG. 3, the core narrowest portion 43 exists in the central portion (the portion located around the wearer's leg) of the absorbent core 40 in the vertical direction X, that is, The absorbent core 40 has a sand shape in a plan view as shown in FIG. 3, whereby distortion and friction applied to the core narrowest portion 43 and its vicinity due to the movement of the wearer's legs or the like are reduced. There is. Therefore, the shape of the absorbent core 40 is less likely to collapse in the first place.

That is, in order to more effectively prevent the shape of the absorbent core 40 from collapsing, the "core" is placed on the adhesive surface of the absorbent core 40 (the skin-facing surface or the non-skin-facing surface of the absorbent core 40). In addition to establishing the magnitude relationship of "adhesive area ratio of adhesive 9 at the lateral end 40S> adhesive area ratio of adhesive 9 at the core lateral center 40M", the absorbent core 40 has a crotch portion B. (The central portion of the absorbent core 40 in the vertical direction X) has a constricted portion (core narrowest portion 43) having a length in the lateral direction Y, that is, a width shorter than that of the peripheral portion, and the constricted portion in the lateral direction Y. It is preferable that the skin-side core wrap sheet 41 and the non-skin-side core wrap sheet 42 are bonded to each other via an adhesive 9 at the outer position of the above.

Further, as described above, the improvement of the rigidity of the entire absorber 4 due to the presence of the sublayer 5 may lead to the suppression of the shape collapse of the absorbent core 40. Therefore, in order to more effectively prevent the shape of the absorbent core 40 from collapsing, the "core" is placed on the adhesive surface of the absorbent core 40 (the skin-facing surface or the non-skin-facing surface of the absorbent core 40). In addition to the magnitude relationship of "adhesive area ratio of adhesive 9 at the lateral end 40S> adhesive area ratio of adhesive 9 at the center 40M of the core", the surface sheet 2 and the absorber 4 (skin) are further established. It is preferable that a liquid-permeable sublayer 5 is arranged between the side core wrap sheet 41).

More reliably achieves the effect of adopting the specific magnitude relationship of the adhesive area ratio of the adhesive 9 on the adhesive adhesive surface (skin facing surface or non-skin facing surface) of the absorbent core 40 described above. From the viewpoint of making the absorbent core 40 adhere to the skin facing surface or the non-skin facing surface, the adhesive area ratio of the adhesive 9 at the lateral end portion 40S of the core and the adhesive area 9 of the adhesive 9 at the central lateral portion 40M of the core. The ratio to the rate is preferably 2 or more, and more preferably 3 or more as the former / the latter on the premise that the former> the latter. On the other hand, the upper limit of such a ratio is not particularly limited, but at the boundary position between the former (core lateral end 40S) and the latter (core lateral central 40M) due to a sudden change in rigidity when the diaper 1 is worn. From the viewpoint of reducing the risk of breaking the absorbent core 40, the former / latter is preferably 15 or less, more preferably 10 or less, assuming the former> the latter.

On the adhesive-adhesive surface of the absorbent core 40 (the skin-facing surface or the non-skin-facing surface of the absorbent core 40), the adhesive area ratio of the adhesive 9 at the lateral end portion 40S of the core is preferably 5% or more, more preferably 5% or more. Is 10% or more, preferably 75% or less, more preferably 50% or less, and the adhesion area ratio of the adhesive 9 at the central portion 40M in the lateral direction of the core on the adhesive adhesion surface is preferably 2%. Above, more preferably 5% or more, preferably 30% or less, still more preferably 20% or less. The adhesion area ratio of the adhesive 9 in the core lateral central portion 40M is 0%, that is, the adhesive 9 is not adhered to the core lateral central portion 40M on the skin facing surface or the non-skin facing surface of the absorbent core 40. You may.

On the adhesive-attached surface of the absorbent core 40 (the skin-facing surface or the non-skin-facing surface of the absorbent core 40), the basis weight of the adhesive 9 at the lateral end portion 40S of the core is preferably 3 g / m ² or more, and further. It is preferably 5 g / m ² or more. On the other hand, the upper limit of the basis weight of the adhesive 9 of the core lateral end 40S is not particularly limited, but due to a sudden change in rigidity when the diaper 1 is worn, the core lateral end 40S and the core lateral central 40M From the viewpoint of reducing the risk of the absorbent core 40 being broken at the boundary position, the concentration is preferably 30 g / m ² or less, more preferably 20 g / m ² or less.
On the adhesive-attached surface of the absorbent core 40 (the skin-facing surface or the non-skin-facing surface of the absorbent core 40), the basis weight of the adhesive 9 at the central portion 40M in the lateral direction of the core prevents the absorbent core 40 from losing its shape. From the viewpoint of the balance between the flexibility and the flexibility of the absorbent core 40 (absorbent 4), preferably 0.5 g / m ² or more, more preferably 1 g / m ² or more, and preferably 15 g / m. ^{It is 2} or less, more preferably 10 g / m ² or less.

The magnitude relationship of the above-mentioned "adhesive area ratio of the adhesive 9 at the lateral end portion 40S of the core> the adhesive area ratio of the adhesive 9 at the central portion 40M in the core lateral direction" is the skin-facing surface and the non-skin facing surface of the absorbent core 40. It suffices if it is established on either one of the surfaces, but from the viewpoint of ensuring that the action and effect of adopting such a magnitude relationship are more reliably achieved, it is established at least on the skin-facing surface of the absorbent core 40. Is preferable, and it is more preferable that the absorbent core 40 is formed on both the skin-facing surface and the non-skin-facing surface. When the magnitude relationship is established on both the skin-facing surface and the non-skin-facing surface of the absorbent core 40, the adhesion pattern of the adhesive 9 may be the same or different between the skin-facing surface and the non-skin-facing surface. You may.

From the same viewpoint, it is preferable that the adhesive area ratio of the adhesive 9 is uniform at the lateral end portion 40S of the core. The term "uniform adhesive area ratio" as used herein means that the adhesive patterns of the adhesive 9 are the same at any two locations of the core lateral end portion 40S, and the two arbitrary locations are the same. They have a quadrangular shape in a plan view of 20 mm in length and 20 mm in width, respectively. If this condition is not satisfied, the adhesive area ratio is non-uniform. On the adhesive-adhering surface of the absorbent core 40 (skin-facing surface or non-skin-facing surface of the absorbent core 40), one and the other of both ends 40S and 40S in the lateral direction of the core are usually the adhesive areas of the adhesive 9. The rates are the same, but may be different.

Further, referring to FIG. 3, the region extending from the ventral vertical end 1FE of the diaper 1 to the position corresponding to 2/3 of the total length of the vertical X of the diaper 1 is the front region 1F and the rest of the diaper 1. (A region corresponding to 1/3 of the total length of the vertical direction X of the diaper 1 in the length of the vertical direction X) is the rear side region 1R, and the adhesive adhesion surface of the absorbent core 40 (absorbency). The magnitude relationship of the above-mentioned "adhesive area ratio of the adhesive 9 at the lateral end 40S of the core> the adhesive area ratio of the adhesive 9 at the central 40M of the core" on the skin-facing surface or the non-skin-facing surface of the core 40 is , It is preferable that it is established at least in the front region 1F. The reason is that the excretory part of the wearer such as the penis and the anus is usually biased to the ventral side in the vertical direction X, so that when the diaper 1 is worn, the anterior area is more than the posterior area 1R (dorsal part C). This is because the 1F (the portion of the ventral portion A and the crotch portion B closer to the ventral side A) is likely to be moistened by excrement, and the shape of the absorbent core 40 is likely to be deformed in the anterior region 1F. Further, regarding the movement of the wearer's leg, which is one of the causes of the shape collapse of the absorbent core 40, the range of motion of the leg is usually larger on the ventral side than on the dorsal side, which is caused by the movement of the leg. The shape of the absorbent core 40 is more likely to collapse in the front region 1F than in the rear region 1R. From the above, it is preferable that the magnitude relationship regarding the adhesion area ratio of the adhesive 9 is established at least in the front region 1F. A more preferable form is a form in which the magnitude relationship is established not only in the front region 1F but also in the entire area of the adhesive-adhering surface of the absorbent core 40 (the skin-facing surface or the non-skin-facing surface of the absorbent core 40). be.

From the same viewpoint, with reference to FIG. 3, the adhesion area ratio of the adhesive 9 on the adhesive adhesion surface of the absorbent core 40 (skin facing surface or non-skin facing surface of the absorbent core 40) is the front region 1F. It is preferable that the core laterally both ends 40SF and 40SF, the core laterally both ends 40SR and 40SR of the rear region 1R, and the core lateral central portion 40M are larger in this order. That is, the core lateral end 40SF of the front region 1F is the maximum, the core lateral central portion 40M is the minimum regardless of whether it is the front region 1F or the rear region 1R, and the core lateral direction of the rear region 1R is the minimum. It is preferable that the end portion 40SR is between the two.

On the skin-facing surface or the non-skin-facing surface of the absorbent core 40, the adhesion area ratio of the adhesive 9 at the lateral end portion 40SF of the core in the front region 1F and the adhesive area ratio of the adhesive 9 at the central portion 40M in the core lateral direction. The ratio is preferably 2.5 or more, more preferably 3.5 or more, and preferably 15 or less, still more preferably 10 or less, as the former / the latter, assuming the former> the latter.
Further, on the skin-facing surface or the non-skin-facing surface of the absorbent core 40, the adhesion area ratio of the adhesive 9 at the lateral end portion 40SR of the core in the rear region 1R and the adhesion area of the adhesive 9 at the central portion 40M in the core lateral direction. The ratio to the rate is preferably 2 or more, more preferably 3 or more, and preferably 15 or less, still more preferably 10 or less as the former / the latter, assuming the former> the latter.

Although the present invention has been described above based on the embodiment, the present invention can be appropriately modified without being limited to the embodiment.
For example, in the above-described embodiment, the skin-side core wrap sheet 41 and the non-skin-side core wrap sheet 42 form one continuous sheet, but both sheets 41 and 42 are separate sheets from each other. Is also good. In that case, the skin-side core wrap sheet 41 and the non-skin-side core wrap sheet 42 may have the same length, that is, the width in the lateral direction, or may be different. If the widths of both sheets 41 and 42 are different, whichever is longer may be used. For example, the skin-side core wrap sheet 41 has the same width as the maximum width of the skin-facing surface of the absorbent core 40, that is, has a size capable of covering the entire skin-facing surface of the absorbent core 40, and is not. The skin-side core wrap sheet 42 can be wider than the sheet 41. The wide non-skin side core wrap sheet 42 covers the entire non-skin facing surface of the absorbent core 40, and extends outward in the width direction Y from both side edges along the vertical direction X of the absorbent core 40. The extending portion thereof may be rolled up on the skin-side core wrap sheet 41 arranged to face the skin-facing surface of the absorbent core 40, and may cover both side edges of the sheet 41 along the vertical direction X. ..

Further, from the viewpoint of improving absorbency, leakage resistance and the like, a groove formed by integrally compacting the surface sheet 2 and the absorber 4 may be formed on the skin-facing surface of the diaper 1.
The present invention is not limited to the deployable disposable diapers as in the above embodiment, and broadly includes articles used for absorbing body fluids (urine, loose stools, menstrual blood, sweat, etc.) discharged from the human body, and is of a pants type. Disposable diapers, sanitary napkins, sanitary shorts and the like are also included.
All the parts of only one embodiment described above can be mutually used as appropriate.

1 Deployable disposable diaper (absorbent article)
2 Front sheet 3 Back sheet 4 Absorber 40 Absorbent core 40M Core lateral center 40S Core lateral end 40SF Front area core Lateral end 40SR Rear area core Lateral end 41 Skin side core wrap sheet 42 Non-skin side core wrap sheet 43 Core narrowest part 5 Sublayer 9 Core wrap sheet Adhesive for joining A Ventral side B Crotch part C Dorsal side F Front side area R Rear side area X Vertical direction Y Lateral direction

Claims (4)

A liquid-retaining absorbent core having a longitudinal direction extending from the ventral side of the wearer to the dorsal side via the crotch portion and a lateral direction orthogonal to the longitudinal direction, and a core wrap sheet covering the absorbent core. It is an absorbent article to be provided.
An adhesive is attached to at least one of the skin-facing surface and the non-skin-facing surface of the absorbent core, and the core wrap sheet is bonded to the adhesive-adhesive surface via the adhesive.
Regarding the adhesion area ratio of the adhesive on the adhesive adhesion surface of the absorbent core, the adhesion area ratio of the adhesive at the lateral end portions of the core located at each of the lateral ends of the absorbent core is the side of the core. A magnitude relationship that is larger than the adhesion area ratio of the adhesive in the central portion in the lateral direction of the core sandwiched between both ends of the direction is established on both the skin-facing surface and the non-skin-facing surface of the absorbent core. Glue,
It said core transverse end 50% the adhesion area of the adhesive is 10% or more in the section below, adhesion area ratio of the adhesive in the core transverse direction central portion is Ri der than 20% to 5%
An absorbent article in which the adhesive area ratio of the adhesive at the lateral end of the core is 3 times or more and 10 times or less of the adhesive area ratio of the adhesive at the central portion of the core. The region extending from the ventral longitudinal end of the absorbent article at a distance corresponding to two-thirds of the total length of the absorbent article in the longitudinal direction is the anterior region, and the remaining region of the absorbent article is the posterior region. The absorbent article according to claim 1, wherein the magnitude relationship is established at least in the front region when the region is used. The absorbency according to claim 2 , wherein the adhesion area ratio of the adhesive is larger in the order of both ends in the lateral direction of the core in the front region, both ends in the lateral direction of the core in the rear region, and the central portion in the lateral direction of the core. Goods. The absorbent article according to claim 1 or 2 , wherein the adhesive area ratio is uniform at the lateral end of the core.

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