JP7099937B2 - Disposable diapers - Google Patents

Description

The present invention relates to a disposable diaper provided with a sweat-absorbing sheet having a sweat-absorbing function.

As a disposable diaper, a front sheet arranged so as to be in contact with the wearer's skin, a back sheet arranged on the side farther from the wearer's skin than the front sheet, and an absorber intervened between the two sheets. It is known that the absorber is composed of an absorbent core containing an absorbent material such as pulp and a core wrap sheet covering the absorbent core. In disposable diapers with such a configuration, for the purpose of reducing skin troubles such as heat rash, it is possible to place a sweat-absorbing sheet containing a hydrophilic material capable of absorbing sweat at a part that may come into contact with the wearer's skin when worn. It has been done conventionally.

Patent Document 1 describes that a sweat-absorbing sheet is attached on a hydrophobic sheet covering the inner surface side of the front-back waist circumference region in a disposable diaper. The entire sweat-absorbent sheet overlaps with the hydrophobic sheet in the thickness direction, and a non-bonding region that does not join the hydrophobic sheet and a non-bonding region from the inner end to the outer portion of the sweat-absorbent sheet and the non-bonding region. It has a bonding region to be bonded to the hydrophobic sheet in the outer portion of the. The inner end of the joint region between the hydrophobic sheet and the waist circumference region is arranged inward from the inner end of the joint region between the sweat-absorbent sheet and the hydrophobic sheet.

Japanese Unexamined Patent Publication No. 2007-259874

It is preferable that the sweat-absorbing sheet has a structure in which after absorbing the sweat of the wearer, the absorbed sweat is easily transferred in the direction away from the wearer's skin in the thickness direction of the sweat-absorbing sheet. In a disposable diaper provided with a sweat-absorbing sheet, the portion on which the sweat-absorbing sheet is placed is often a part that easily rubs against the wearer's body during wearing, and the sweat-absorbing sheet is easily turned over. In particular, if the inner end portion of the sweat-absorbent sheet is provided with a non-joining region as in the disposable diaper described in Patent Document 1, the non-joining region is more likely to be turned over. When the sweat-absorbing sheet that absorbs sweat in this way is turned over, the sweat that has moved away from the wearer's skin will come into contact with the wearer's skin. May cause skin problems.

Therefore, an object of the present invention is to provide a disposable diaper in which the sweat-absorbing sheet is less likely to be turned over during wearing and skin troubles caused by sweat are less likely to occur.

The present invention is a disposable diaper comprising an absorbent body including a surface sheet forming a surface facing the skin, having a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction, and the wearer when wearing the diaper. The waist circumference is provided around the waistline, and the waistline is divided into a ventral portion arranged on the ventral side of the wearer and a dorsal portion arranged on the dorsal side at the time of wearing. At least the back side portion is arranged as a sheet constituting the back side portion at the dorsal end portion in the vertical direction of the absorbent body so as to straddle the vertical direction and the skin facing surface of the absorbent body. A hydrophobic sheet arranged on the side and a sweat-absorbing sheet arranged on the skin-facing surface side of the hydrophobic sheet are provided, and the sweat-absorbing sheet and the hydrophobicity are provided in a region overlapping the absorbent body in the thickness direction. It provides a disposable diaper in which the bonding strength of the first bonding region for bonding the sheet is larger than the bonding strength of the second bonding region for bonding the hydrophobic sheet and the surface sheet.

According to the disposable diaper of the present invention, the sweat-absorbing sheet is less likely to be turned over during wearing, and skin troubles caused by sweat are less likely to occur.

FIG. 1 is a perspective view schematically showing a pants-type disposable diaper, which is an embodiment of the disposable diaper of the present invention. FIG. 2 is a developed plan view schematically showing the skin facing surface side (inner surface side) of the diaper shown in FIG. 1 in the expanded and extended state. FIG. 3 is a cross-sectional view schematically showing a cross section taken along line III-III of FIG. 2 (a cross section along the lateral direction). FIG. 4 is a cross-sectional view schematically showing the IV-IV line cross section (cross section along the lateral direction) of FIG. 2. FIG. 5 is a cross-sectional view schematically showing a VV line cross section (cross section along the vertical direction) of FIG. 2, and one end portion of the diaper shown in FIG. 1 in the vertical direction (longitudinal end portion on the dorsal side). ) Is enlarged and schematically shown. FIG. 6 is an explanatory diagram illustrating how a pocket is formed after wearing the diaper shown in FIG. FIG. 7 is a vertical sectional view schematically showing an enlarged vertical end portion (longitudinal end portion on the dorsal side side) of the diaper according to another embodiment of the disposable diaper of the present invention (corresponding to FIG. 5). Is.

Hereinafter, the present invention will be described based on the preferred embodiment thereof with reference to the drawings. 1 to 5 show a pants-type disposable diaper 1, which is an embodiment of the disposable diaper of the present invention. As shown in FIGS. 1 to 5, the diaper 1 has a vertical direction X corresponding to the front-back direction of the wearer, that is, a direction extending from the ventral side to the dorsal side via the crotch portion, and a lateral direction Y orthogonal to the vertical direction X. have. The diaper 1 includes an absorbent body 2 including a surface sheet 21 that forms a skin-facing surface.

In the present specification, the "skin facing surface" is a surface of the disposable diaper or its constituent members (for example, a surface sheet) that is directed toward the wearer's skin when the disposable diaper is worn, that is, relatively close to the wearer's skin. The side, the "non-skin facing surface", is the surface of the disposable diaper or its constituents that faces the side opposite to the skin side when the disposable diaper is worn, that is, the side relatively far from the wearer's skin. The term "when worn" as used herein means a state in which the normal proper wearing position, that is, the correct wearing position of the disposable diaper is maintained.

As shown in FIGS. 1 and 2, the diaper 1 has a crotch portion M and a ventral portion F and a dorsal portion R extending in the longitudinal direction X from the front and back of the crotch portion M. The inseam M is a portion arranged in the crotch part of the wearer when the diaper 1 is worn, and the ventral side F is the ventral side of the wearer, that is, the vertical direction X, rather than the crotch part M when the diaper 1 is worn. The dorsal side portion R is a portion arranged on the front side of the diaper, and the dorsal side portion R is a portion arranged on the dorsal side of the wearer, that is, on the posterior side of the vertical direction X, rather than the inseam M in the wearing state of the diaper 1. The ventral side F and the dorsal side R are waist circumferences arranged around the wearer's waist when the diaper 1 is worn. In other words, the diaper 1 has a waist circumference portion, and the waist circumference portion is divided into a ventral side portion F and a dorsal side portion R.

The diaper 1 is provided with an absorbent body 2 including a liquid-retaining absorber 23 in the central portion in the lateral direction Y, and the wearer's body is more than the non-skin facing surface side of the absorbent body 2, that is, the absorbent body 2. An exterior body 3 arranged on the side far from the body is provided, and both side edges of the exterior body 3 along the vertical direction X in each of the ventral side F and the dorsal side R are adhesives, heat seals, ultrasonic seals, etc. The pair of side seals S, S, the waist opening WH through which the wearer's body is passed, and the wearer's lower limbs are passed through, as shown in FIG. A pair of leg openings LH, LH are formed.

The absorbent body 2 has a rectangular shape in a plan view in the unfolded and extended state of the diaper 1 as shown in FIG. 2, and extends in the longitudinal direction X from the ventral side F to the dorsal side R, and the longitudinal direction thereof. Is arranged in the central portion of the outer body 3 in the horizontal direction Y so as to coincide with the vertical direction X of the diaper 1 in the unfolded and stretched state, and is joined to the outer body 3 by an adhesive. The "expanded and stretched state" of the diaper 1 means that the diaper 1 is separated by the side seal portion S to be in the deployed state, and the diaper 1 in the deployed state is stretched with the elastic members of each part to have design dimensions (the influence of the elastic members is completely affected). It means the state of being expanded until it becomes the same as the dimensions when it is expanded in a plane with it removed.

As shown in FIGS. 3 and 4, the absorbent body 2 has a liquid-permeable surface sheet 21 that forms a skin-facing surface, and a liquid-impermeable, impermeable, or water-repellent surface that forms a non-skin-facing surface. The back surface sheet 22 and the liquid-retaining absorber 23 interposed between the two sheets 21 and 22 are provided, and these are integrated by a known joining means such as an adhesive. In the surface sheet 21, the total length in the vertical direction X and the total length in the horizontal direction Y are at least the same as or longer than the total length in the vertical direction X and the total length in the horizontal direction Y of the absorber 23, respectively, and the absorber 23 faces the skin. It is arranged on the surface side and covers the absorber 23. The total length of the absorbent body 2 in the vertical direction X is at least the same as the total length of the absorbent body 23, and both ends 23a and 23a of the absorbent body 23 in the vertical direction are the vertical lengths of the absorbent main body 2 as shown in FIGS. 2 and 5. It is located inward of the vertical direction X from the direction end. As the back sheet 22, various types conventionally used for this type of disposable diaper can be used without particular limitation. For example, as the back sheet 22, a resin film, a laminate of the resin film and a non-woven fabric, or the like can be used. The surface sheet 21 will be described later.

As shown in FIGS. 3 and 4, the absorbent body 23 covers the liquid-retaining absorbent core 24 mainly composed of an absorbent material and the outer surface of the absorbent core 24, that is, the skin facing surface and the non-skin facing surface. It is configured to include a core wrap sheet 25 to be used. The absorbent core 24 has a rectangular shape long in the vertical direction X in a plan view as shown in FIG. 2, and extends in the vertical direction X from the ventral side portion F to the dorsal side portion R. As the absorbent material that is the main component of the absorbent core 24, those used as the absorbent material in this kind of disposable diaper can be used without particular limitation, for example, wood pulp, hydrophilized synthetic fiber, and the like. Examples include water-absorbent polymers. As a typical form of the absorbent core 24, a fiber aggregate of hydrophilic fibers such as wood pulp, or a fiber aggregate in which a particulate water-absorbing polymer is retained can be exemplified.

In the diaper 1, the core wrap sheet 25 is one continuous liquid-permeable sheet having a width of 2 times or more and 3 times or less the length of the lateral Y of the absorbent core 24, and is shown in FIGS. 3 and 4. As shown, the entire surface of the absorbent core 24 facing the skin is covered, and the absorbent core 24 extends outward in the lateral direction Y from both side edges along the vertical direction X, and the extending portion thereof is absorbent. It is wound down below the core 24 to cover the entire non-skin facing surface of the absorbent core 24. The absorbent core 24 and the core wrap sheet 25 may be joined by a known joining means such as a hot melt type adhesive. As the core wrap sheet 25, for example, a liquid permeable sheet such as paper, various non-woven fabrics, and perforated films can be used.

In the present invention, the core wrap sheet 25 does not have to be such a single sheet, for example, one skin-side core wrap sheet that covers the skin-facing surface of the absorbent core 24 and the skin. A separate body from the side core wrap sheet may be configured to include one non-skin side core wrap sheet that covers the non-skin facing surface of the absorbent core 24.

As shown in FIGS. 2 and 3, the absorbent main body 2 has leak-proof cuffs 26 on both side portions along the vertical direction X on the skin facing surface of the absorbent main body 2. The leak-proof cuff 26 on each side is one of a water-repellent and breathable leak-proof cuff forming sheet 27 that is continuous over the entire length of the vertical X of the absorbent body 2 and a lateral Y of the sheet 27. It is configured to include one or a plurality of cuff-forming elastic members 28 fixed to the end in an extended state in the vertical direction X. The leak-proof cuff forming sheet 27 has a cuff body in which the other end in the lateral direction Y extends to the non-skin facing surface of the back sheet 22 of the absorbent body 2 over the entire length of the absorbent body 2 in the vertical direction X. It is fixed by the fixing portion 291. In the leak-proof cuff forming sheet 27, one end of the lateral Y is a surface sheet on the absorber 23 at each of the ventral end 2F and the dorsal end 2R of the absorbent body 2 in the vertical direction X. It is fixed to the skin facing surface of 21 by a free end fixing portion 292. When the diaper 1 is worn, the contraction force of the elastic member 28 for forming the cuff acts in the vertical direction X, and at least in the inseam M, one end of the seat 27 becomes a free end, and the cuff body fixing portion 291 is used as a starting point. A leak-proof cuff 26 is formed that stands up toward the wearer's skin. In this way, the leak-proof cuff 26 has the free end fixed on the skin-facing surface of the surface sheet 21 by the free end fixing portion 292 at the ventral end 2F and the dorsal end 2R, and the diaper 1 has a free end. When worn, the elastic member 28 contracts so that the free end portion on which the elastic member 28 for forming a cuff is arranged stands up at the lower crotch M.

As shown in FIGS. 2 and 4, the leak-proof cuff forming sheet 27 constituting the pair of leak-proof cuffs 26, 26 arranged on both sides of the absorbent body 2 along the vertical direction X is the absorbent body 2. A folded portion 31E made of a hydrophobic sheet, which will be described later, is arranged on the ventral end portion 2F and the dorsal end portion 2R of the absorbent body 2 across the vertical direction X and is arranged on the skin facing surface side of the absorbent body 2. .. The folded-back portion 31E is joined to the pair of leak-proof cuffs 26, 26 to be covered at the ventral end portion 2F and the dorsal end portion 2R at the cuff joint region 7K. The joining means for joining the folded-back portion 31E forming each cuff joining region 7K and the leak-proof cuff forming sheet 27 constituting each leak-proof cuff 26 is not particularly limited, and known joining means such as an adhesive or fusion is used. It can be used, and in diaper 1, an adhesive is used.

The exterior body 3 forms the outer shape of the diaper 1 in the expanded and extended state as shown in FIG. 2, and the peripheral edge of the exterior body 3 is the contour line of the diaper 1 in that state, that is, the ventral portion F, the inseam M, and the crotch portion M. The contour lines of each of the dorsal portions R are formed. As shown in FIG. 2, the exterior body 3 has a rectangular shape in the ventral portion F and the dorsal portion R in which the length in the lateral direction Y is longer than that in the vertical direction X, and the ventral portion F and the dorsal portion are formed. In the crotch portion M located between the crotch portion M, both side edges of the exterior body 3 along the vertical direction X, that is, a pair of leg edge portions LS and LS are curved in a convex arc shape toward the center in the lateral direction Y. In a plan view as shown in FIG. 2, the central region of the vertical direction X has an hourglass shape constricted inward in the horizontal direction Y.

As shown in FIGS. 3 to 5, the exterior body 3 has an outer layer sheet 31 that forms the outer surface of the diaper 1, that is, a non-skin facing surface, and an inner layer sheet 32 that is arranged to face the skin facing surface of the outer layer sheet 31. It is configured to include a laminated body with. In the wearing state of the diaper 1, the outer layer sheet 31 is located on the side far from the wearer's body to form the non-skin facing surface (outer surface) of the diaper 1, and the inner layer sheet 32 is located on the side closer to the wearer's body. Then, the skin-facing surface (inner surface) of the diaper 1 is formed. The outer layer sheet 31 and the inner layer sheet 32 are joined to each other at a predetermined portion via a joining means such as an adhesive.

In the diaper 1, as shown in FIGS. 2 and 5, the outer layer sheet 31 extends to the ventral side F and the dorsal side R from the edge of the inner layer sheet 32 in the vertical direction X, and faces the skin of the inner layer sheet 32. It has a folded portion 31E that is folded back on the surface side. In the ventral portion F, the folded portion 31E covers the ventral end portion 2F in the vertical direction X of the absorbent main body 2 and is joined to the surface sheet 21 of the absorbent main body 2 at the second joining region 7D. .. Further, in the dorsal side portion R, the folded-back portion 31E covers the dorsal end portion 2R of the absorbent main body 2 in the vertical direction X, and is joined to the surface sheet 21 of the absorbent main body 2 at the second joining region 7D. ing. The joining means between the folded-back portion 31E forming the second joining region 7D and the surface sheet 21 is not particularly limited, and known joining means such as an adhesive and fusion can be used. In the diaper 1, the adhesive is used. It is used.
Although the dorsal portion R is enlarged and not shown in FIG. 5, the ventral portion F is also configured in the same manner as the dorsal portion R, and unless otherwise specified, the ventral portion F is also configured in the same manner as the dorsal portion R. As for the ventral portion F, the description of the dorsal portion R is appropriately applied.

As described above, in the diaper 1, as shown in FIGS. 2 and 4, in the ventral portion F, the folded portion 31E is arranged across the ventral end portion 2F of the absorbent body 2 in the vertical direction X. It is also arranged on the skin-facing surface side of the absorbent body 2. The folded-back portion 31E covers the ventral end portion 2F of the absorbent main body 2 and is joined to the surface sheet 21 of the absorbent main body 2 at the second joining region 7D, so that the pair of protective main bodies 2 is protected. It is joined to the leak cuffs 26 and 26 at the cuff joining area 7K. Then, in the ventral side portion F, the folded portion 31E is also joined to the inner layer sheet 32 of the exterior body 3. Similarly, in the dorsal portion R, the folded-back portion 31E covers the dorsal end portion 2R of the absorbent main body 2 and is joined to the surface sheet 21 of the absorbent main body 2 at the second joining region 7D. It is joined to the pair of leakage-proof cuffs 26, 26 of the absorbent body 2 at the cuff joining region 7K. Then, in the dorsal side portion R, the folded-back portion 31E is also joined to the inner layer sheet 32 of the exterior body 3. The folded-back portion 31E and the inner layer sheet 32 are joined to each other at a predetermined portion via a joining means such as an adhesive.

The sheets 31 and 32 constituting the exterior body 3 may be sheets of the same type or different types as long as they are hydrophobic sheets. Examples of different types of sheets include morphologies with different elasticity. Specifically, for example, as the outer layer sheet 31, a hydrophobic elastic sheet having elasticity in the lateral direction Y is used, and as the inner layer sheet 32, a hydrophobic non-expandable sheet having no elasticity is used. Can be done. Further, for example, the elasticity of the outer layer sheet 31 may be partially different, and specifically, the portions of the outer layer sheet 31 located on the ventral side F and the dorsal side R have elasticity in the lateral direction Y. There is a form in which the portion of the outer layer sheet 31 which is made of the stretchable sheet and is located at the lower part M of the crotch is made of a non-stretchable sheet which does not have elasticity.

Examples of the stretchable sheet that can be used as the exterior body 3 include a stretchable sheet in which an stretchable fiber layer is integrated on both sides or one side of the elastic fiber layer, and the elastic fiber layer and the stretchable fiber layer are combined. Examples of the method of integration include a method of laminating both and entwining them with a water flow, a method of entwining fibers by air through, and a method of joining by heat embossing, an adhesive, ultrasonic waves, or the like. Examples of the non-stretchable sheet that can be used as the exterior body 3 include non-woven fabrics produced by various manufacturing methods, and specific examples thereof include spunbonded non-woven fabrics, air-through non-woven fabrics, and needle-punched non-woven fabrics.

As shown in FIGS. 1, 2 and 5, a plurality of thread-like or band-shaped elastic members around the waist are arranged in a laterally Y-extended state in each of the ventral portion F and the dorsal portion R, and a plurality of them. The elastic members 33 around the waist of the book are intermittently arranged at predetermined intervals in the vertical direction X. As described above, the elastic member 33 around the waist is arranged in a state in which the elastic elasticity is exhibited, so that the opening edge portion of the waist opening WH has a substantially continuous annular waist over the entire circumference thereof. Gathers are formed. Further, one or a plurality of thread-like or band-shaped leg elastic members 34 for forming leg gathers are arranged in an extended state in the leg edge portion LS forming the opening edges of each of the pair of leg openings LH and LH. As a result, at the opening edges of each of the pair of leg openings LH and LH, substantially continuous annular leg gathers are formed over the entire circumference thereof. All of these elastic members 33 and 34 are sandwiched and fixed between the outer layer sheet 31 constituting the exterior body 3 and the inner layer sheet 32 by a joining means such as an adhesive.

In the diaper 1, as described above, as shown in FIG. 5, the exterior body 3 is arranged on the side farther from the skin of the wearer of the diaper 1 than the absorbent body 2. Further, the exterior body 3 has elasticity in the lateral direction Y due to the provision of the elastic member 33 around the waist that is fixed in the lateral direction Y in an extended state, and the exterior body 3 has elasticity in the same direction. It consists of sheets.

As used herein, the term "stretchable" means a property of being expandable in a predetermined direction and contracting when the extension is released. The fact that the sheet does not substantially stretch in a certain direction (it is non-stretchable) means that the sheet hardly stretches even if a pulling force is applied to the sheet in the certain direction. do. For example, when a sample having a length of 15 cm and a width of 5 cm is pulled in the longitudinal direction with a material tensile tester such as Tencilon and the breaking elongation at the time of breaking the sample is 10% or less. The sample is substantially non-stretchable in the longitudinal direction. The elongation at break can be calculated by (the sample length at break-the original length of the sample) / (the original length of the sample) x 100.

As shown in FIG. 5, the dorsal portion R is, as a sheet constituting the dorsal portion R, a hydrophobic sheet covering the dorsal end portion 2R of the absorbent main body 2 and the hydrophobic sheet on the skin facing surface side. It is provided with a sweat absorbing sheet 10 to be arranged. In the diaper 1, the sheets constituting the dorsal side portion R are the outer layer sheet 31, the inner layer sheet 32, the folded portion 31E of the outer layer sheet 31, and the sweat absorbing sheet 10, and are hydrophobic to cover the dorsal end portion 2R of the absorbent body 2. The folded portion 31E of the outer layer sheet 31 corresponds to the sex sheet. An elastic member 33 is arranged on the dorsal side R in an extended state in the lateral direction Y. Although the dorsal portion R may be partially hindered from the elasticity of the elastic member 33, the dorsal portion R has elasticity in the lateral direction Y due to the provision of the elastic member 33 as a whole. is doing.

The sweat-absorbing sheet 10 is intended to absorb sweat around the wearer's waist, and is arranged at a portion of the diaper 1 that can come into contact with the wearer's skin when worn. In the diaper 1, as shown in FIGS. 1, 2, 4, and 5, the wearer is placed on the ventral side F and the dorsal side R, which are the waist circumferences arranged around the wearer's waist when worn. The sweat-absorbing sheet 10 is arranged at a position close to the skin of the diaper. The sweat absorbing sheet 10 is joined to the folded portion 31E of the outer layer sheet 31, which is a hydrophobic sheet, at the first joining region 7U. The joining means between the sweat absorbing sheet 10 forming the first joining region 7U and the folded-back portion 31E is not particularly limited, and known joining means such as an adhesive and fusion can be used.
From the viewpoint of absorbing sweat, the basis weight of the sweat-absorbing sheet is preferably 12 g / m ² or more, more preferably 15 g / m ² or more, and preferably 50 g / m ² or less, still more preferably 45 g / m ² or less. be.

In the diaper 1, the sweat-absorbing sheet 10 has a long shape in one direction, specifically a rectangular shape in a plan view as shown in FIG. 2, and its longitudinal direction coincides with the lateral direction Y, so that the ventral side F and the back The side portions R are arranged over the entire length of each lateral direction Y. The sweat-absorbing sheet 10 long in the lateral direction Y is arranged on the dorsal side R across both the absorber-arranged region in which the absorber 23 is arranged and the absorber-non-arranged region in which the absorber 23 is not arranged. Has been done. The absorber non-arranged region includes a region (side flap region) located on both sides of the absorber 23 along the vertical direction X and outside the virtual extension line thereof in the horizontal direction Y, and a vertical end of the absorber (side flap region). The vertical end 23a) of the absorber 23 and a region (end flap region) located outside the vertical direction X from the virtual extension line thereof are included. As described above, the sweat absorbing sheet 10 is arranged so as to straddle both the absorber-arranged region and the absorber-non-arranged region in the dorsal side R, and is not arranged in the inseam M and is not arranged in the ventral side portion. It differs from the surface sheet 21 arranged over the ventral portion F and the dorsal portion R in that it is arranged on the F or the dorsal portion R.

The sweat absorbing sheet 10 is arranged along the opening end of the waist opening WH on the skin-facing surface side of the dorsal side R in the vicinity of the opening end. As shown in FIG. 5, the sweat absorbing sheet 10 has an outer end 10a in the vertical direction X relatively close to the waist opening WH and a vertical direction X located relatively far from the waist opening WH on the inseam M side. It has an inner end 10b of the above, and both vertical ends 10a and 10b extend in parallel with the horizontal direction Y. The outer end 10a of the sweat absorbing sheet 10 in the vertical direction X is located outside the vertical end 23a of the absorber 23, and the inner end 10b of the sweat absorbing sheet 10 in the vertical direction X is the absorber. It is located inward of the vertical direction X with respect to the vertical end 23a of the 23. The vertical end 23a of the absorber 23 is also the vertical end of the absorbent core 24 or the core wrap sheet 25.

In the diaper 1, since the sweat-absorbing sheet 10 having a sweat-absorbing function is arranged at a portion where the wearer's skin can come into contact (around the waist opening WH on the skin facing surface), it is caused by sweat such as heat rash, eczema, and rash. Reduces skin problems. Then, in the region Q where the sweat absorbing sheet 10 and the absorbent main body 2 overlap in the thickness direction shown in FIG. 5, the first joining region 7U where the sweat absorbing sheet 10 and the folded portion 31E which is a hydrophobic sheet are joined is joined. The strength is higher than the joining strength of the second joining region 7D that joins the folded portion 31E, which is a hydrophobic sheet, and the surface sheet 21 of the absorbent main body 2. With such a configuration, even if the sweat-absorbing sheet 10 absorbs the sweat of the wearer while the diaper 1 is being worn and then the sweat-absorbing sheet 10 rubs against the wearer's body, the sweat-absorbing sheet 10 can be used during wearing. It is difficult to turn over, and the folded-back portion 31E is easily turned over from the surface sheet 21 before the sweat-absorbing sheet 10 is turned over from the folded-back portion 31E. If the sweat-absorbing sheet 10 is turned over and touches the skin, the sweat-absorbing sheet 10 is doubled in the turned-up part, so that the amount of sweat absorbed increases. It is thought that troubles are likely to occur. On the other hand, when the surface sheet 21 is turned over, the folded-back portion 31E is a hydrophobic sheet, so that even if the diaper 1 is continuously worn in that state, skin troubles such as heat rash are unlikely to occur. Further, when the folded-back portion 31E is turned up from the surface sheet 21, a pocket P is formed between the turned-up hydrophobic folded-back portion 31E and the surface sheet 21, as shown in FIG. It is possible to prevent leakage of body fluid such as urine from the portion R.

From the viewpoint of further facilitating the above effect, the bonding strength of the first bonding region 7U is preferably 1.5 times or more, preferably 2.0 times or more, the bonding strength of the second bonding region 7D. It is more preferably 7.5 times or less, further preferably 5.0 times or less, and preferably 1.5 times or more and 7.5 times or less, and 2.0 times or less. It is more preferably 5.0 times or more.
Specifically, the bonding strength of the first bonding region 7U is preferably 1.5N / 25mm or more, more preferably 2.0N / 25mm or more, and preferably 25N / 25mm or less. , 20N / 25mm or less, more preferably 1.5N / 25mm or more and 25N / 25mm or less, and further preferably 2.0N / 25mm or more and 20N / 25mm or less.
The bonding strength of the second bonding region 7D is preferably 0.5 N / 25 mm or more, more preferably 1.0 N / 25 mm or more, and preferably 3.0 N / 25 mm or less. It is more preferably .5 N / 25 mm or less, more preferably 0.5 N / 25 mm or more and 3.0 N / 25 mm or less, and further preferably 1.0 N / 25 mm or more and 2.5 N / 25 mm or less. ..
The joint strength of the first joint region 7U and the second joint region 7D is measured by the following method.

<Measurement method of joint strength>
In a 22 ° C. 65% RH environment, the disposable diaper is stretched to the extent that the gathers formed by the shrinkage of each elastic member disappear, and includes the region Q where the sweat absorbing sheet 10 and the absorbent body 2 overlap in the thickness direction. In addition, a rectangular measuring piece having a length of 25 mm in the horizontal direction Y and 40 mm in the vertical direction X is cut out. When cutting out, the measurement piece is cut out so that the portion corresponding to the overlapping region Q is located at least at one end in the vertical direction X of the measurement piece. Next, for example, when measuring the joint strength of the first joint region 7U, the sweat-absorbing sheet 10 and the folded-back portion 31E, which is a hydrophobic sheet, are peeled off at the other end side of the vertical direction X of the measurement piece. The portion of the sweat-absorbing sheet 10 in which this measuring piece is peeled off from the upper chuck and the lower chuck of a tensile tester (for example, Tensilon tensile tester "RTA-100" manufactured by Orientec Co., Ltd.) so that the vertical direction X is the tensile direction. And attach the folded part 31E. At this time, the distance between the two chucks is 10 mm. Then, while the position of the lower chuck is fixed, the upper chuck is raised at a speed of 300 mm / min. As the upper chuck rises, the measuring piece breaks in the vertical direction X and separates into the sweat absorbing sheet 10 and the folded-back portion 31E. The breaking strength is measured until the length of the broken portion reaches 25 mm, and the maximum value thereof is obtained. This measurement is repeated 5 times, and the average value is taken as the bonding strength of the first bonding region 7U. When measuring the joint strength of the second joint region 7D, peel off between the folded portion 31E, which is a hydrophobic sheet, and the surface sheet 21 on the other end side of the vertical direction X of the measurement piece, and then peel off the upper chuck and the lower chuck. The portion of the folded-back portion 31E peeled off and the portion of the surface sheet 21 are attached. After that, the joint strength of the second joint region 7D is measured in the same manner as the joint strength of the first joint region 7U.

A viewpoint that when the surface sheet 21 and the sweat-absorbing sheet 10 move following the movement of the skin while wearing the diaper 1, the folded-back portion 31E is more easily turned over from the folded-back portion 31E before the sweat-absorbing sheet 10 is turned over from the folded-back portion 31E. Therefore, in the region Q where the sweat-absorbing sheet 10 and the absorbent main body 2 overlap in the thickness direction, it is preferable that the sweat-absorbing sheet 10 and the absorbent core 24 overlap. The surface sheet 21 arranged at a position near the absorbent core 24 follows the movement of the skin as compared with the sweat absorbing sheet 10 arranged at a position farther from the absorbent core 24 than the surface sheet 21. This is because the constituent fibers are easily deformed, and the second joint region 7D that joins the folded-back portion 31E and the surface sheet 21 is easily distorted and easily peeled off.

From the viewpoint of further easily forming the pocket P shown in FIG. 6 between the hydrophobic folded-back portion 31E and the surface sheet 21 and further preventing leakage of body fluid such as urine from the dorsal portion R, at least the dorsal portion R In, the bonding strength of the cuff bonding region 7K of each leakage-proof cuff 26 is preferably larger than the bonding strength of the second bonding region 7D, more preferably 1.5 times or more, and more preferably 2.0 times or more. It is particularly preferable that there is, more preferably 7.5 times or less, particularly preferably 5.0 times or less, and further preferably 1.5 times or more and 7.5 times or less. , 2.0 times or more and 5.0 times or less is particularly preferable.
Specifically, the joint strength of the cuff joint region 7K of each leakage-proof cuff 26 is preferably 1.5 N / 25 mm or more, more preferably 2.0 N / 25 mm or more, and 15 N / 25 mm or less. It is preferably 10 N / 25 mm or less, more preferably 1.5 N / 25 mm or more and 15 N / 25 mm or less, and further preferably 2.0 N / 25 mm or more and 10 N / 25 mm or less. preferable.
The joint strength of the cuff joint region 7K of each leakage-proof cuff 26 is measured by the following method.

<Measuring method of joint strength of cuff joint region 7K>
In a 22 ° C. 65% RH environment, the disposable diaper is stretched to the extent that the gathers formed by the shrinkage of each elastic member disappear, and 25 mm in the horizontal direction Y and 40 mm in the vertical direction X so as to include the cuff joint region 7K. A long rectangular measuring piece is cut out in the vertical direction X of. When cutting out, the cuff joint region 7K is cut out so as to be located at least one end in the vertical direction X of the measurement piece. Next, the leak-proof cuff forming sheet 27 and the folded-back portion 31E, which is a hydrophobic sheet, are peeled off on the other end side of the measurement piece in the vertical direction X, and the measurement piece is in the tensile direction in the vertical direction X. As described above, the portion of the leak-proof cuff forming sheet 27 and the portion of the folded portion 31E that have been peeled off are attached to the upper chuck and the lower chuck of the tensile tester (for example, the Tensiron tensile tester "RTA-100" manufactured by Orientec Co., Ltd.). At this time, the distance between the two chucks is 10 mm. Then, while the position of the lower chuck is fixed, the upper chuck is raised at a speed of 300 mm / min. As the upper chuck rises, the measuring piece breaks in the vertical direction X and separates into the leak-proof cuff forming sheet 27 and the folded-back portion 31E. The breaking strength is measured until the length of the broken portion reaches 10 mm, and the maximum value thereof is obtained. This measurement is repeated 5 times, and the average value is taken as the bonding strength of the cuff bonding region 7K.

As shown in FIG. 5, from the viewpoint of preventing the sweat-absorbing sheet from coming into contact with the skin due to the formation of a portion where the sweat-absorbing sheet is doubled and the amount of sweat-absorbing is increased when the sweat-absorbing sheet is turned over, the sweat-absorbing sheet 10 is formed in the vertical direction X. The inner end 10b is located at the same position in the vertical direction X as the inner end 31E1 in the vertical direction X of the hydrophobic folded-back portion 31E, or is outside the vertical direction X than the inner end 31E1 of the folded-back portion 31E. It is preferably located on the side, and more preferably located on the outer side of the vertical direction X than the inner end 31E1 of the folded-back portion 31E. This is because when the diaper 1 is arranged in this way, the sweat absorbing sheet 10 is unlikely to be turned over due to the inner end 10b of the sweat absorbing sheet 10.

As shown in FIG. 5, the first joining region 7U joining the sweat absorbing sheet 10 and the folded portion 31E is the inner end in the vertical direction X from the viewpoint of making the folded portion 31E easier to turn over from the surface sheet 21. Is 7U1 located at the same position in the vertical direction X as the inner end 7D1 in the vertical direction X of the second joint region 7D that joins the folded portion 31E and the surface sheet 21, or is located in the second joint region 7D? It is preferably located inward in the vertical direction X than the inner end 7D1, and more preferably located inward in the vertical direction X than the inner end 7D1 of the second joining region 7D.

At least from the viewpoint of facilitating the three-dimensional formation of the shape of the pocket P formed between the hydrophobic folded portion 31E and the surface sheet 21, and further preventing the leakage of body fluid such as urine from the dorsal portion R, at least the dorsal portion. In the side portion R, the folded-back portion 31E made of a hydrophobic sheet covering the dorsal end portion 2R of the absorbent body 2 is arranged at the innermost side of the lateral Y in each leakage-proof cuff 26, and the free end fixing portion 292. It is preferable that it extends to a region located inward in the vertical direction X rather than (see FIG. 4) and is joined to each leakage-proof cuff 26. In other words, it is preferable that the cuff joint region 7K (see FIG. 2) of each leakage-proof cuff 26 extends to a region located inward in the vertical direction X from the free end fixing portion 292.

It is preferable that the interfiber distance of the surface sheet 21 is larger than the interfiber distance of the sweat absorbing sheet 10 from the viewpoint of making it easier for the folded portion 31E to be turned over from the surface sheet 21 before the sweat absorbing sheet 10 is turned over from the folded portion 31E. This is because when the distance between the fibers of the surface sheet 21 becomes large, the number of joint points between the folded-back portion 31E and the surface sheet 21 decreases, and the bonding strength tends to decrease. When the surface sheet 21 has a laminated structure, the interfiber distance of the layer on the side facing the skin most likely to affect the bonding strength with the folded-back portion 31E is measured. Similarly, when the sweat absorbing sheet 10 has a laminated structure, the interfiber distance of the layer on the non-skin facing surface side, which tends to affect the bonding strength with the folded portion 31E, is measured. The interfiber distance of the surface sheet 21 is preferably 250 μm or less, more preferably 150 μm or less, more preferably 50 μm or more, still more preferably 70 μm or more, and specifically, specifically. It is preferably 50 μm or more and 250 μm or less, and more preferably 70 μm or more and 150 μm or less. The interfiber distance of the sweat absorbing sheet 10 is preferably 150 μm or less, more preferably 90 μm or less, more preferably 5 μm or more, further preferably 10 μm or more, and specifically, specifically. It is preferably 5 μm or more and 150 μm or less, and more preferably 10 μm or more and 70 μm or less. The difference between the interfiber distance of the surface sheet 21 and the interfiber distance of the sweat absorbing sheet 10 is preferably 20 μm or more, more preferably 30 μm or more, and preferably 100 μm or less, still more preferably 90 μm or less as the former-latter. Is.
The interfiber distance of the surface sheet 21 and the interfiber distance of the sweat absorbing sheet 10 are measured by the following methods.

<Measurement method of interfiber distance>
The interfiber distance of a fiber aggregate such as a non-woven fabric or paper is obtained by the following formula (1) based on the assumption of Wrotnowski. The following formula (1) is generally used when determining the interfiber distance of a fiber aggregate. Under the Wrotnowski assumption, the fibers are columnar and the fibers are regularly arranged without intersecting.
When the sheet to be measured has a single-layer structure, the interfiber distance of the single-layer structure sheet can be obtained by the following formula (1).
When the sheet to be measured has a multi-layer structure such as SMS non-woven fabric, the interfiber distance of the multi-layer structure sheet is determined according to the following procedure.
First, the interfiber distance of each fiber layer constituting the multilayer structure is calculated by the following formula (1). At that time, the thickness t, the basis weight W, the resin density ρ of the fiber, and the fiber diameter D used in the following formula (1) are those for the layer to be measured, respectively. The thickness t, the basis weight W, and the fiber diameter D are the average values of the measured values at a plurality of measurement points, respectively.
The thickness t (mm) is measured by the following method. First, the sheet to be measured is cut in a longitudinal direction of 50 mm and a width direction of 50 mm to prepare a cut piece of the sheet. Next, this cut piece is placed on a flat plate, a glass plate on the flat plate is placed on the flat plate, and a weight is evenly placed on the glass plate so that the load including the glass plate becomes 49 Pa, and then the cutting is performed. Measure the thickness of the piece. The measurement environment is a temperature of 20 ± 2 ° C., a relative humidity of 65 ± 5%, and a microscope (manufactured by KEYENCE CORPORATION, VHX-1000) is used as the measuring device. To measure the thickness of the cut piece, first, an enlarged photograph of the cut surface of the cut piece is obtained. This magnified photograph simultaneously captures objects of known dimensions. Next, the scale is adjusted to the enlarged photograph of the cut surface of the cut piece, and the thickness of the cut piece, that is, the thickness of the sheet to be measured is measured. The above operation is performed three times, and the average value of the three times is taken as the thickness t of the sheet to be measured. When the sheet to be measured is a laminated product, the boundary is determined from the fiber diameter and the thickness is calculated.
For the basis weight W (g / m ² ), the sheet to be measured is cut into a predetermined size (for example, 12 cm × 6 cm), and after the mass measurement, the mass measurement value is obtained by the area obtained from the predetermined size. It is obtained by dividing (“Basis weight W (g / m ² ) = mass ÷ area obtained from a predetermined size”). Measure 4 times and use the average value as the basis weight.
The resin density ρ (g / cm ³ ) of the fiber is measured using a density gradient tube according to the measurement method of the density gradient tube method described in the JIS L1015 chemical fiber staple test method (URL is http: ///. kikakuri.com/l/L1015-2010-01.html, JIS Handbook Fiber-2000 for books, P.764-765 of (Japan Standards Association).
For the fiber diameter D (μm), 10 fiber cross sections of the cut fibers are measured using an S-4000 type electric field radiation scanning electron microscope manufactured by Hitachi, Ltd., and the average value thereof is taken as the fiber diameter. The method for measuring the fiber diameter D follows the <method for measuring the fiber diameter> described later.
Next, the interfiber distance of each layer is multiplied by the ratio of the thickness of the layer to the total thickness of the multi-layer structure, and the numerical values of the obtained layers are summed up to obtain the desired multi-layer structure sheet. The interfiber distance of the constituent fibers of is obtained. For example, in an SMS nonwoven fabric having a three-layer structure composed of two S layers and one M layer, the two S layers are collectively treated as one layer, and the thickness t of the entire three-layer structure is 0.11 mm. When the thickness t of the S layer is 0.1 mm, the interfiber distance LS of the S layer is 47.8 μm, the thickness t of the M layer is 0.01 mm, and the interfiber distance LS of the M layer is 3.2 μm, such an SMS nonwoven fabric. The interfiber distance of the constituent fibers of is 43.8 μm [= (47.9 × 0.1 + 3.2 × 0.01) /0.11].

A viewpoint that when the surface sheet 21 and the sweat-absorbing sheet 10 move following the movement of the skin while wearing the diaper 1, the folded-back portion 31E is more easily turned over from the folded-back portion 31E before the sweat-absorbing sheet 10 is turned over from the folded-back portion 31E. Therefore, it is preferable that the thickness t21 of the surface sheet 21 is larger than the thickness t10 of the sweat absorbing sheet 10. Compared to the sweat-absorbing sheet 10, the thicker surface sheet 21 is more likely to deform the constituent fibers, and the second bonding region 7D connecting the folded-back portion 31E and the surface sheet 21 is more likely to be distorted and easily peeled off. This is to become.

The thickness t21 of the surface sheet 21 is preferably 5 mm or less, more preferably 3 mm or less, more preferably 0.2 mm or more, still more preferably 0.5 mm or more, and specifically. It is preferably 0.2 mm or more and 5 mm or less, and more preferably 0.5 mm or more and 3 mm or less. The thickness t10 of the sweat absorbing sheet 10 is preferably 2 mm or less, more preferably 1 mm or less, more preferably 0.1 mm or more, still more preferably 0.2 mm or more, and specifically. It is preferably 0.1 mm or more and 2 mm or less, and more preferably 0.2 mm or more and 1 mm or less. The difference between the thickness t21 of the surface sheet 21 and the thickness t10 of the sweat absorbing sheet 10 is preferably 0.8 mm or more, more preferably 1 mm or more, and preferably 4 mm or less, still more preferably 3 mm or less as the former-the latter. Is.
The thickness t21 of the surface sheet 21 and the thickness t10 of the sweat absorbing sheet 10 are measured by the thickness measuring method in the above-mentioned method for measuring the interfiber distance.

The fiber diameter D21 of the constituent fibers of the surface sheet 21 is larger than the fiber diameter D10 of the constituent fibers of the sweat absorbing sheet 10 from the viewpoint of making it easier for the folded portion 31E to be turned over from the surface sheet 21 before the sweat absorbing sheet 10 is turned over from the folded portion 31E. Larger is preferred. This is because the surface sheet 21 having a large fiber diameter has fewer joint points between the folded-back portion 31E and the surface sheet 21 than the sweat-absorbing sheet 10, and the bonding strength tends to be smaller.

The fiber diameter D21 of the surface sheet 21 is preferably 25 μm or less, more preferably 20 μm or less, more preferably 8 μm or more, still more preferably 10 μm or more, and specifically, specifically. It is preferably 8 μm or more and 25 μm or less, and more preferably 10 μm or more and 20 μm or less. The fiber diameter D10 of the sweat absorbing sheet 10 is preferably 20 μm or less, more preferably 18 μm or less, more preferably 1 μm or more, further preferably 5 μm or more, and specifically, specifically. It is preferably 1 μm or more and 20 μm or less, and more preferably 5 μm or more and 18 μm or less. The difference between the fiber diameter D21 of the surface sheet 21 and the fiber diameter D10 of the sweat absorbing sheet 10 is preferably 2 μm or more, more preferably 3 μm or more, and preferably 10 μm or less, still more preferably 8 μm or less as the former-the latter. Is.
The fiber diameter D21 of the surface sheet 21 and the fiber diameter D10 of the sweat absorbing sheet 10 are measured by the method for measuring the fiber diameter in the above-mentioned method for measuring the interfiber distance.

As shown in FIGS. 3 to 5, the surface sheet 21 has an uneven shape on the skin facing surface from the viewpoint of making it easier for the folded portion 31E to be turned over from the surface sheet 21 before the sweat absorbing sheet 10 is turned over from the folded portion 31E. It is preferable to have it. This is because when the sweat-absorbing sheet 10 is joined only by the convex portion having the uneven shape on the surface facing the skin of the surface sheet 21, the number of joint points between the folded portion 31E and the surface sheet 21 is reduced, and the joining strength tends to be reduced. The uneven shape of the surface facing the skin of the surface sheet 21 is not particularly limited, and a surface sheet having an uneven shape in this type of disposable diaper can be appropriately adopted. As an example of the uneven shape, there is a form in which a plurality of convex portions are arranged in a scattered pattern over the entire surface of the surface sheet facing the skin, and the periphery of each convex portion is a concave portion. The planar view shape of the convex portion is not particularly limited, and may be appropriately selected from a circle, an ellipse, a polygon of a quadrangle or more, and the like. Specifically, for example, on the skin-facing surface of the surface sheet 21, a first concave portion extending in a first direction intersecting in both the vertical direction X and the horizontal direction Y and a second concave portion intersecting the first direction. A form in which the second concave portion extending in a plane line of sight and the second concave portion extending in the direction are arranged in a grid pattern and a convex portion is present in each of a plurality of sections surrounded by both concave portions can be mentioned. Further, as another example of the uneven shape, the convex portion as the ridge extending in the vertical direction X or the horizontal direction Y and the concave portion as the groove extending in the same direction are orthogonal to the extending direction thereof. Examples thereof include forms arranged alternately in the direction. Further, the convex portion (ridge portion) constituting the uneven shape may be a solid structure in which the constituent fibers of the surface sheet are filled inside, or may be a hollow structure. As an example of a surface sheet having a hollow convex portion, two sheets are partially joined in a laminated state, and one sheet relatively close to the wearer's skin is the other sheet at a portion other than the joint. Examples thereof include a form in which a plurality of convex portions are formed so as to project in a direction away from (a sheet relatively far from the wearer's skin) and project toward the wearer's skin side. As shown in FIGS. 3 and 4, the non-skin facing surface of the surface sheet 21 is usually a flat surface having substantially no uneven shape.

As the surface sheet 21, a liquid-permeable sheet material conventionally used in this type of disposable diaper can be used. For example, a non-woven fabric manufactured by the card method, an air-through non-woven fabric, a spunbonded non-woven fabric, a meltblown non-woven fabric, and a span can be used. Various non-woven fabrics such as lace non-woven fabric and needle punch non-woven fabric; films made liquid permeable by opening means and the like can be mentioned. These non-woven fabrics and films may be hydrophilized with a hydrophilizing agent such as a surfactant. The basis weight of the surface sheet 21 is preferably 12 g / m ² or more, more preferably 15 g / m ² or more, and preferably 50 g / m ² or less, still more preferably 45 g / m ² or less.

In the diaper 1, as described above, the waist elastic member 33 is arranged in a laterally extended state on the ventral side F and the dorsal side R, which are the waist circumferences arranged around the wearer's waist when worn. A stretchable region formed by the waistline elastic member 33 is formed on each of the ventral side portion F and the dorsal side portion R. It is possible to further facilitate the formation of the pocket P shown in FIG. 6 with the surface sheet 21. Specifically, in the diaper 1, as shown in FIG. 2, at least in the dorsal side R, the folded portion 31E and the surface sheet 21 which are hydrophobic sheets overlap at the same position in the vertical direction X and the region K where they overlap in the thickness direction. A certain region KT is divided into a central portion KT1 in which the absorbent body 2 is located and a pair of side portions KT2 and KT2 located laterally Y from each of both side edges of the absorbent body 2 along the vertical direction X. can. The central portion KT1 preferably has a lower elongation stress in the lateral direction than the side portion KT2. If the lateral extension stress of the central portion KT1 is lower than the lateral extension stress of each side portion KT2 at least in the dorsal portion R, the pocket P formed by the central portion KT1 is unlikely to collapse. This is to become. As a method of reducing the lateral extension stress of the central portion KT1, at least a part of each waistline elastic member 33 arranged in the lateral direction Y in an extended state in each of the ventral side F and the dorsal side R is used. In the region overlapping with the absorbent main body 2 in the thickness direction, a method of finely dividing the region so as not to exhibit elastic elasticity can be mentioned. The elongation stress is measured by the following method.

<Measurement method of elongation stress>
The diaper 1 is unfolded and spread in a plane, and the central portion KT1 and each side portion KT2 are placed 70 mm in the horizontal direction Y and 25 mm in the vertical direction X along a straight line parallel to the horizontal direction Y of the diaper 1. Cut out as a long rectangular measuring piece in the direction Y. At the time of this cutting, the exterior body 3 including the sweat absorbing sheet 10 from which the absorbent main body 2 and the like are removed is used, and the measurement piece is cut from the exterior body 3. Both ends of the measurement piece in the longitudinal direction (horizontal direction Y) are sandwiched between chucks of a Tensilon universal tester (RTC-1210A) manufactured by ORIENTEC Co., Ltd. At this time, the distance between the two chucks is 30 mm. Then, the measuring piece is extended in the longitudinal direction at a speed of 300 mm / min, and the stress of the measurement sample at that time is measured. Specifically, when the length of the measurement piece in the lateral direction Y in the state where the sheets 31 and 32 of the exterior body 3 are not contracted by the elastic member 33 is set to 100, the measurement piece is extended to a length equivalent to 90. The tensile load (cN) when the material is contracted to a length corresponding to 70 after the measurement is performed is defined as the elongation stress of the measured piece. The elongation stress of the measurement piece, that is, the elongation stress of the central portion KT1 and the elongation stress of each side portion KT2 are calculated as the average stress by converting the length of each portion in the longitudinal direction (horizontal direction Y). ..
It should be noted that the reason for defining the return force at a length equivalent to 70 when the length of the measurement piece in the non-contracted state in the lateral direction is 100 as described above as the elongation stress of the measurement piece is the diaper. It is the length assumed when it is attached.

The ratio of the lateral extension stress of each side portion KT2 to the lateral extension stress of the central portion KT1 (each side portion KT2 / central portion KT1) is preferably 1.2 or more, more preferably 1. It is 5 or more, preferably 4.0 or less, and more preferably 3.5 or less.
The lateral extension stress of the central portion KT1 is preferably 5 cN / mm or more, more preferably 7.5 cN / mm or more, and preferably 25 cN / mm or less, still more preferably 20 cN / mm or less.
The lateral extension stress of each side portion KT2 is preferably 2 cN / mm or more, more preferably 3 cN / mm or more, and preferably 15 cN / mm or less, still more preferably 12 cN / mm or less.

The sweat absorbing sheet 10 is typically a non-woven fabric. As the non-woven fabric constituting the sweat-absorbing sheet 10, a non-woven fabric produced by various manufacturing methods that can be used as a constituent member of this type of disposable diaper can be used without particular limitation, but the sweat-absorbed sweat is not left on the side facing the skin. From the viewpoint, the sweat-absorbing sheet 10 is preferably a sheet having a lower hydrophilicity on the skin-facing surface side than on the non-skin-facing surface side.

As an index of the hydrophilicity of the surface (skin facing surface, non-skin facing surface) of the sweat absorbing sheet 10, the contact angle with water measured by the following method can be used. It can be determined that the smaller the contact angle with water measured by the following method, the higher the hydrophilicity (lower hydrophobicity), and the larger the contact angle, the lower the hydrophilicity (higher hydrophobicity).
The contact angle between the skin facing surface of the sweat absorbing sheet 10 and the ion-exchanged water is preferably 90 ° or more, more preferably 100 ° or more, and preferably 150 ° or less, preferably 140 ° or less. More preferably, it is more preferably 90 ° or more and 150 ° or less, and further preferably 100 ° or more and 140 ° or less.
The contact angle between the non-skin facing surface of the sweat absorbing sheet 10 and the ion-exchanged water is preferably smaller than 90 °, more preferably 88 ° or less, particularly preferably 85 ° or less, and It is preferably 35 ° or more, more preferably 40 ° or more, specifically, 35 ° or more and less than 90 °, further preferably 35 ° or more and 88 ° or less, and 40 ° or more. It is particularly preferable that it is ° or more and 85 ° or less.

<Measuring method of contact angle of fiber layer (nonwoven fabric)>
From the fiber layer (non-woven fabric) to be measured, a rectangular shape in a plan view of 150 mm in the MD direction, which is the machine direction at the time of manufacturing the non-woven fabric, and 70 mm in the CD direction orthogonal to the MD direction is cut out and used as a measurement sample, and the contact angle in the measurement sample is obtained. A droplet of ion-exchanged water is attached to the surface to be measured, the droplet is recorded, and the contact angle is measured based on the recorded image. More specifically, a microscope VHX-1000 manufactured by KEYENCE CORPORATION is used as a measuring device, and a medium-magnification zoom lens is attached to the microscope with the medium-magnification zoom lens tilted at 90 °. The measurement sample is set on the measurement stage of the measuring device so that the surface to be measured faces upward and can be observed from the CD direction of the measurement sample. Then, a droplet of 3 μL of ion-exchanged water is attached to the surface to be measured of the measurement sample set on the measurement stage, and an image of the droplet is recorded and incorporated into the measurement device. From the multiple recorded images, 10 images with clear ends or one end in the CD direction of the droplet are selected, the contact angle of the droplet is measured for each of the 10 images, and the average value of the contact angles thereof is measured. Is the contact angle of the fiber layer (nonwoven fabric) to be measured. The measurement environment is 20 ° C./50% RH.

The form of the sweat-absorbing sheet having the above-mentioned “skin facing surface <non-skin facing surface” magnitude relationship with respect to the hydrophilicity is not particularly limited, and a single-layer structure may be used. A preferred embodiment of such a sweat-absorbing sheet is a laminated structure including a first layer forming a skin facing surface and a second layer forming a non-skin facing surface, and the first layer is the second layer. A laminated non-woven fabric having a lower hydrophilicity than that of the above can be mentioned.

In the laminated nonwoven fabric, one or more other layers may be interposed between the first layer and the second layer in the laminated structure. Further, it is preferable that the plurality of layers constituting the laminated structure are joined to each other and integrated, and the joint portion is thinner than the peripheral portion and the layers constituting the laminated structure are fused with each other. The fused portion between the layers is preferable. Such a fused portion is subjected to squeezing processing accompanied by a melting promoting means for promoting melting of constituent fibers (thermoplastic fibers) such as heat and ultrasonic waves, specifically, for example, heat sealing processing and ultrasonic sealing. It can be formed by applying it to a laminated structure. Further, it is preferable that a plurality of the fused portions are scattered on the skin-facing surface and / or the non-skin-facing surface of the laminated nonwoven fabric. The fused portion may be concavely recessed from the skin facing surface side to the non-skin facing surface side, and conversely, may be concavely recessed from the non-skin facing surface side to the skin facing surface side. , The former is preferable. Similar to the laminated non-woven fabric, the non-woven fabric having a single-layer structure may have the fused portion in which constituent fibers (thermoplastic fibers) are fused to each other.

When the sweat-absorbing sheet 10 has the fused portion, the fused portion is arranged on the skin-facing surface of the sweat-absorbing sheet from the viewpoint of adhesiveness to the folded-back portion 31E which is a hydrophobic sheet. preferable. In the form in which the fused portion is arranged on the skin facing surface of the sweat absorbing sheet, in addition to the form in which the skin facing surface and the non-skin facing surface of the sweat absorbing sheet are arranged only on the skin facing surface side, the skin It also includes a form arranged on both the facing surface and the non-skin facing surface. When the fused portion is arranged on both the skin facing surface and the non-skin facing surface, the depth of the recess of the fused portion may be larger on the skin facing surface side than on the non-skin facing surface side. preferable.

As the fiber (the fiber whose content preferably occupies 70% by mass or more of all the constituent fibers of the first layer) which is the main component of the first layer (the layer forming the skin facing surface) of the laminated nonwoven fabric, for example, hydrophobicity is used. Thermoplastic fiber (heat fusion fiber) can be used. As the material of the hydrophobic thermoplastic fiber, as the hydrophobic thermoplastic resin, for example, polyolefin such as polyethylene and polypropylene; polyester such as polyethylene terephthalate; polyamide such as nylon 6 and nylon 66; polyacrylic acid and polymethacrylic acid. Examples thereof include alkyl esters, polyvinyl chloride, and polyvinylidene chloride, and one of these can be used alone or in combination of two or more.

Further, the fibers (fibers having a content of preferably 70% by mass or more of all the constituent fibers of the second layer) which are the main constituents of the second layer (layer forming the non-skin facing surface) of the laminated non-woven fabric are hydrophilic. Sexual thermoplastic fibers (heat-fused fibers) can be used, and specifically, inherently hydrophilic thermoplastic fibers such as polyacrylonitrile fibers may be used, or hydrophobic fibers that can be used in the first layer. The sexual thermoplastic fiber may be hydrophilized, and one of these fibers may be used alone or in combination of two or more. The latter "hydroplastic fiber that has been hydrophilized" includes, for example, a thermoplastic fiber kneaded with a hydrophilizing agent, a thermoplastic fiber having a hydrophilizing agent attached to the surface, and a thermoplastic fiber that has been subjected to plasma treatment. And so on. The hydrophilizing agent is not particularly limited as long as it is a general hydrophilizing agent used for hygienic products. In addition, fibers having inherent hydrophilicity, for example, natural or semi-natural fibers such as cellulose fibers can also be used.

The first layer and the second layer constituting the laminated nonwoven fabric may be short fiber nonwoven fabrics mainly composed of short fibers or long fiber nonwoven fabrics mainly composed of long fibers, respectively. Examples of the short fiber non-woven fabric include air-through non-woven fabric, spunlace non-woven fabric, needle punch non-woven fabric, and chemical bond non-woven fabric. Examples of the long-fiber non-woven fabric include a single-layer non-woven fabric such as a spunbonded non-woven fabric and a melt-blown non-woven fabric, a laminated non-woven fabric in which a spunbond layer mainly composed of long fibers, a melt-blown layer and the like are laminated, and a heat-rolled non-woven fabric by the card method. Examples of the laminated non-woven fabric include spunbond-spunbond laminated non-woven fabric (SS non-woven fabric), spunbond-spunbond-spunbond laminated non-woven fabric (SSS non-woven fabric), spunbond-melt blown-spunbond laminated non-woven fabric (SMS non-woven fabric), and span. Examples thereof include bond-melt blown-melt blown-spunbond non-woven fabric (SMMS non-woven fabric).

The basis weight of the first layer (layer forming the skin facing surface) constituting the laminated nonwoven fabric is preferably 8 g / m ² or more, more preferably 10 g / m ² or more, and preferably 30 g / m ² or less. More preferably, it is 25 g / m ² or less.
The basis weight of the second layer (layer forming the non-skin facing surface) constituting the laminated nonwoven fabric is preferably 10 g / m ² or more, more preferably 13 g / m ² or more, and preferably 40 g / m ² or less. More preferably, it is 35 g / m ² or less.

FIG. 7 shows another embodiment of the present invention. Regarding other embodiments described later, components different from the above-mentioned diaper 1 will be mainly described, and similar components will be designated by the same reference numerals and description thereof will be omitted. The description of the diaper 1 is appropriately applied to the components not particularly described.

In the diaper 1 shown in FIG. 7, the arrangement of the leakage-proof cuffs 26 arranged on both sides along the vertical direction X on the skin-facing surface of the absorbent body 2 is different from that of the diapers 1 shown in FIGS. 1 to 5 described above. There is. Specifically, in the diaper 1 shown in FIG. 4, the other end portion of the leak-proof cuff forming sheet 27 in the lateral direction Y is attached to the non-skin facing surface of the back surface sheet 22 of the absorbent main body 2 by the cuff main body fixing portion 291. A leak-proof cuff 26 is fixed, and one end of the sheet 27 stands up as a free end with the cuff body fixing portion 291 as a starting point due to the contraction force of the cuff forming elastic member 28. In this way, the cuff body fixing portion 291 of the leak-proof cuff 26 is arranged between the back surface sheet 22 and the exterior body 3, and is inside the lateral direction Y rather than the side edge along the vertical direction X of the absorber 23. It is arranged in the direction. On the other hand, in the diaper 1 shown in FIG. 7, the other end of the leak-proof cuff forming sheet 27 in the lateral direction Y is lateral to the side edge of the absorber 23 on the skin-facing surface of the surface sheet 21 along the vertical direction X. It is fixed by the cuff body fixing portion 291 arranged outside in the direction Y, and one end of the sheet 27 is a free end starting from the cuff body fixing portion 291 due to the contraction force of the cuff forming elastic member 28. A leak-proof cuff 26 that stands up as a portion is formed. In this way, the cuff body fixing portion 291 of the leak-proof cuff 26 is arranged on the skin-facing surface of the surface sheet 21, and is located outside the lateral direction Y of the absorber 23 along the vertical direction X. It is arranged. The diaper 1 shown in FIG. 7 also has the same effect as the diaper 1 shown in FIGS. 1 to 5.

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-mentioned diaper 1, as shown in FIG. 2, the ventral side F and the dorsal side R are each provided with the sweat absorbing sheet 10, but at least the dorsal side R is provided with the sweat absorbing sheet 10. Just do it.

Further, in the above-mentioned diaper 1, as shown in FIG. 5, the folded portion 31E of the outer layer sheet 31 is used as the hydrophobic sheet covering the dorsal end portion 2R of the absorbent body 2, but it is a separate hydrophobic sheet. A sex sheet may be used.

When the hydrophobic sheet is the folded portion 31E of the outer layer sheet 31 or a separate sheet, the form of the hydrophobic sheet is not particularly limited, and a non-woven fabric having a single-layer structure may be used, and a third layer forming a skin facing surface may be used. And a laminated nonwoven fabric having a laminated structure including a fourth layer forming a non-skin facing surface facing the surface sheet 21 may be used. In the laminated nonwoven fabric, one or more other layers may be interposed between the third layer and the fourth layer. In the case of the non-woven fabric having a single-layer structure, it may have a second fused portion for fusing the constituent fibers (thermoplastic fibers) to each other. The laminated nonwoven fabric may have a second fused portion that fuses the layers to each other. Such a second fused portion is squeezed with a melting promoting means for promoting melting of constituent fibers (thermoplastic fibers) such as heat and ultrasonic waves, specifically, for example, heat sealing processing and ultrasonic sealing. Can be formed by applying to the constituent fibers.

When the hydrophobic sheet has the second fused portion, the second fused portion is attached to the surface sheet 21 of the hydrophobic sheet from the viewpoint of the adhesiveness between the sweat absorbing sheet 10 and the surface sheet 21. It is preferably arranged on the facing non-skin facing surface. In the form in which the second fused portion is arranged on the non-skin facing surface of the hydrophobic sheet, it is arranged only on the non-skin facing surface side of the skin facing surface and the non-skin facing surface of the hydrophobic sheet. In addition to the morphology, it also includes morphology arranged on both sides of the skin facing surface and the non-skin facing surface. When the second fused portion is arranged on both the skin facing surface and the non-skin facing surface, the depth of the recess of the second fusion portion is closer to the non-skin facing surface side than the skin facing surface side. Is preferably large.

Further, in the diaper 1, as shown in FIG. 2, the exterior body 3 has a continuous shape extending over the ventral side F, the inseam M, and the dorsal side R. Instead, the exterior body 3 has a continuous shape. It is a form divided into a ventral seat member and a dorsal seat member, and the absorbent main body 2 may be bridged and fixed to both seat members.

Further, the disposable diaper of the present invention is not limited to the pants-type disposable diaper such as the above-mentioned diaper 1, and can be applied to, for example, a deployable disposable diaper.

Further, the following additional notes will be disclosed with respect to the above-described embodiment of the present invention.

<1>
A disposable diaper that has an absorbent body including a surface sheet that forms a surface facing the skin, and has a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction. The waist circumference portion is provided, and the waist circumference portion is divided into a ventral portion arranged on the ventral side of the wearer and a dorsal portion arranged on the dorsal side at the time of wearing, and at least the dorsal portion. The side portion is arranged as a sheet constituting the dorsal side at the dorsal end portion in the vertical direction of the absorbent main body so as to straddle the vertical direction and is arranged on the skin facing surface side of the absorbent main body. A hydrophobic sheet and a sweat-absorbing sheet arranged on the skin-facing surface side of the hydrophobic sheet are provided, and the sweat-absorbing sheet and the hydrophobic sheet are joined in a region overlapping with the absorbent body in the thickness direction. A disposable diaper in which the bonding strength of the first bonding region is larger than the bonding strength of the second bonding region in which the hydrophobic sheet and the surface sheet are bonded.

<2>
The disposable diaper according to <1>, wherein the surface sheet has a distance between fibers larger than the distance between fibers of the sweat-absorbing sheet.
<3>
The disposable diaper according to <1> or <2>, wherein the surface sheet has an uneven shape on the surface facing the skin.
<4>
In the sweat-absorbing sheet, the inner end in the vertical direction is located at the same position as the inner end in the vertical direction of the hydrophobic sheet, or is located outward in the vertical direction from the inner end of the hydrophobic sheet. The disposable diaper according to any one of <1> to <3>.
<5>
In the first joining region, the inner end in the vertical direction is located at the same position as the inner end in the vertical direction of the second joining region or inward from the inner end of the second joining region. The disposable diaper according to any one of <1> to <4>.
<6>
An elastic region formed by an elastic member arranged in an elongated state in the lateral direction is formed in the dorsal portion, and the region in which the hydrophobic sheet and the surface sheet overlap in the thickness direction is formed in the dorsal portion. The regions at the same position in the vertical direction are the central portion where the absorbent body is located and the pair of side portions located laterally outward from each of the both side edges of the absorbent body along the vertical direction. The disposable diaper according to any one of <1> to <5>, wherein the central portion is classified and the lateral elongation stress is lower than that of each side portion.
<7>
The ratio of the lateral elongation stress of each side portion to the lateral elongation stress of the central portion (each side portion / central portion) is preferably 1.2 or more, more preferably 1.5 or more. The disposable diaper according to <6> above, preferably 4.0 or less, more preferably 3.5 or less.
<8>
The lateral elongation stress of the central portion is preferably 5 cN / mm or more, more preferably 7.5 cN / mm or more, and preferably 25 cN / mm or less, still more preferably 20 cN / mm or less. The disposable diaper according to 6> or <7>.
<9>
The lateral elongation stress of each of the side portions is preferably 2 cN / mm or more, more preferably 3 cN / mm or more, and preferably 15 cN / mm or less, still more preferably 12 cN / mm or less. The disposable diaper according to any one of 6> to <8>.

<10>
The absorbent body has leak-proof cuffs on both sides of the absorbent body facing the skin along the vertical direction, and the bonding strength of the cuff joint region between the leak-proof cuff and the hydrophobic sheet is increased. The disposable diaper according to any one of <1> to <9>, which is larger than the bonding strength of the second bonding region.
<11>
The bonding strength of the cuff bonding region is preferably 1.5 times or more, more preferably 2.0 times or more, and 7.5 times or less the bonding strength of the second bonding region. The disposable diaper according to <10> above, preferably 5.0 times or less.
<12>
The bonding strength of the cuff bonding region is preferably 1.5 N / 25 mm or more, more preferably 2.0 N / 25 mm or more, and preferably 15 N / 25 mm or less, and 10 N / 25 mm or less. The disposable diaper according to <10> or <11>, which is more preferably the disposable diaper.
<13>
The dorsal end of the absorbent body has a free end fixing portion in which the free end of the leak-proof cuff is fixed on the skin-facing surface of the surface sheet, and the hydrophobic sheet is the hydrophobic sheet. 3. The above <10>, wherein the leak-proof cuff extends to a region located inward in the vertical direction from the free end fixing portion arranged in the innermost direction in the lateral direction and is joined to the leak-proof cuff. Disposable diapers.

<14>
The disposable diaper according to any one of <1> to <13>, wherein the sweat-absorbing sheet has lower hydrophilicity on the skin-facing surface side than on the non-skin-facing surface side.
<15>
An exterior body including a laminate of an outer layer sheet forming a non-skin facing surface in a worn state and an inner layer sheet arranged to face the skin facing surface of the outer layer sheet, and arranged on the non-skin facing surface of the absorbent body. The outer layer sheet has a hydrophobic folded portion extending from the vertical end edge of the inner layer sheet and folded back toward the skin facing surface side of the inner layer sheet on the ventral side portion and the dorsal side portion. The disposable diaper according to any one of <1> to <14>, wherein the hydrophobic sheet having and covering the dorsal end portion of the absorbent body is composed of the folded portion of the outer layer sheet. ..
<16>
The disposable diaper according to <15>, wherein the sweat-absorbing sheet preferably has the inner end in the vertical direction located on the outer side in the vertical direction with respect to the inner end of the folded portion.

<17>
The first joining region in which the sweat-absorbing sheet and the folded portion are joined is the vertical portion of the second joining region in which the inner end in the vertical direction joins the folded portion and the surface sheet. The disposable diaper according to <15> or <16>, which is more preferably located inward in the vertical direction than the inner end in the direction.
<18>
The absorbent body includes a liquid-retaining absorber, and the laterally long sweat-absorbing sheet has an absorbent body arrangement region in which the absorbent body is arranged and an absorbent body arranged in the dorsal portion. The disposable diaper according to any one of <1> to <17>, which is arranged across both the non-absorbent non-arranged region and the non-absorbent region.
<19>
The bonding strength of the first bonding region is preferably 1.5 times or more, more preferably 2.0 times or more, and 7.5 times or less of the bonding strength of the second bonding region. The disposable diaper according to any one of <1> to <18>, wherein the diaper is preferably 5.0 times or less, and more preferably 5.0 times or less.
<20>
The bonding strength of the first bonding region is preferably 1.5 N / 25 mm or more, more preferably 2.0 N / 25 mm or more, and preferably 25 N / 25 mm or less, preferably 20 N / 25 mm. The disposable diaper according to any one of <1> to <19>, more preferably the following.
<21>
The bonding strength of the second bonding region is preferably 0.5 N / 25 mm or more, more preferably 1.0 N / 25 mm or more, and preferably 3.0 N / 25 mm or less. The disposable diaper according to any one of <1> to <20>, more preferably 0.5 N / 25 mm or less, and more preferably 0.5 N / 25 mm or more and 3.0 N / 25 mm or less.

<22>
The difference between the interfiber distance of the surface sheet and the interfiber distance of the sweat-absorbing sheet is preferably 20 μm or more, more preferably 30 μm or more, and preferably 100 μm or less, still more preferably 90 μm or less as the former-latter. , The disposable diaper according to any one of <1> to <21>.
<23>
The interfiber distance of the surface sheet is preferably 250 μm or less, more preferably 150 μm or less, more preferably 50 μm or more, still more preferably 70 μm or more, the above <1> to The disposable diaper according to any one of <22>.
<24>
The interfiber distance of the sweat-absorbing sheet is preferably 150 μm or less, more preferably 90 μm or less, more preferably 5 μm or more, still more preferably 10 μm or more, the above <1> to The disposable diaper according to any one of <23>.
<25>
The surface sheet is described in any one of <1> to <24>, wherein a plurality of convex portions are arranged in a scattered pattern over the entire area of the skin facing surface, and the periphery of each convex portion is a concave portion. Disposable diapers.
<26>
The contact angle between the skin-facing surface of the sweat-absorbing sheet and the ion-exchanged water is preferably 90 ° or more, more preferably 100 ° or more, and preferably 150 ° or less, preferably 140 ° or less. The disposable diaper according to any one of <1> to <25>, more preferably.
<27>
The contact angle between the non-skin facing surface of the sweat absorbing sheet and the ion-exchanged water is preferably smaller than 90 °, more preferably 88 ° or less, particularly preferably 85 ° or less, and 35 °. The disposable diaper according to any one of <1> to <26>, wherein the temperature is preferably 40 ° or more, and more preferably 40 ° or more.
<28>
The sweat-absorbing sheet has a fused portion in which thermoplastic fibers are fused to each other, and the fused portion is arranged on the skin-facing surface of the sweat-absorbing sheet. Disposable diaper according to any one of 1.
<29>
The hydrophobic sheet has a second fused portion in which thermoplastic fibers are fused to each other, and the second fused portion is arranged on a non-skin facing surface of the hydrophobic sheet. The disposable diaper according to any one of <1> to <28>.
<30>
The absorbent body has a liquid-retaining absorbent core.
The disposable diaper according to any one of <1> to <29>, wherein the sweat-absorbent sheet and the absorbent core overlap in the region where the sweat-absorbent sheet and the absorbent body overlap in the thickness direction. ..
<31>
The disposable diaper according to any one of <1> to <30>, wherein the thickness of the surface sheet is larger than the thickness of the sweat-absorbing sheet.
<32>
The difference between the thickness of the surface sheet and the thickness of the sweat-absorbing sheet is preferably 0.8 mm or more, more preferably 1 mm or more, and preferably 4 mm or less, still more preferably 3 mm or less as the former-the latter. The disposable diaper according to any one of <1> to <31>.
<33>
The thickness of the surface sheet is preferably 5 mm or less, more preferably 3 mm or less, more preferably 0.2 mm or more, still more preferably 0.5 mm or more, the above <1. > The disposable diaper according to any one of <32>.
<34>
The thickness of the sweat-absorbing sheet is preferably 2 mm or less, more preferably 1 mm or less, more preferably 0.1 mm or more, still more preferably 0.2 mm or more, said <1. > The disposable diaper according to any one of <33>.
<35>
The disposable diaper according to any one of <1> to <34>, wherein the fiber diameter of the constituent fibers of the surface sheet is larger than the fiber diameter of the constituent fibers of the sweat-absorbing sheet.
<36>
The difference between the fiber diameter of the constituent fibers of the surface sheet and the fiber diameter of the constituent fibers of the sweat-absorbing sheet is preferably 2 μm or more, more preferably 3 μm or more, and preferably 10 μm or less, more preferably 10 μm or less, as the former-the latter. The disposable diaper according to any one of <1> to <35>, which is 8 μm or less.
<37>
The fiber diameter of the constituent fibers of the surface sheet is preferably 25 μm or less, more preferably 20 μm or less, and further preferably 8 μm or more, further preferably 10 μm or more, the above <1. > The disposable diaper according to any one of <36>.
<38>
The fiber diameter of the constituent fibers of the sweat-absorbing sheet is preferably 20 μm or less, more preferably 18 μm or less, more preferably 1 μm or more, still more preferably 5 μm or more, the above <1. > The disposable diaper according to any one of <37>.

1 Disposable diapers (pants-type disposable diapers)
F Ventral part M Inseam R Back side 2 Absorbent body 21 Front surface sheet 22 Back surface sheet 23 Absorber 24 Absorbent core 25 Core wrap sheet 26 Leakage-proof cuff 27 Leakage-proof cuff forming sheet 28 Cuff forming elastic member 291 Cuff body fixing part 292 Free end fixing part 2F Ventral end 2R Dorsal end 3 Exterior 31 Outer layer sheet 31E Folded part of outer layer sheet (hydrophobic sheet)
32 Inner layer sheet 33 Elastic member around the waist 7U 1st joint area 7D 2nd joint area 7K Cuff joint area 10 Sweat-absorbent sheet Q Area that overlaps with the absorber in the thickness direction X Vertical direction Y Horizontal direction

Claims (10)

A disposable diaper having an absorbent body including a surface sheet forming a skin-facing surface, and having a vertical direction corresponding to the front-back direction of the wearer and a horizontal direction orthogonal to the vertical direction.
It is provided with a waist circumference portion that is arranged around the wearer's waist when worn, and the waist circumference portion is divided into a ventral portion that is arranged on the ventral side of the wearer and a dorsal portion that is arranged on the dorsal side when worn. It is divided and
At least the dorsal portion is arranged as a sheet constituting the dorsal portion at the dorsal end portion in the vertical direction of the absorbent main body so as to straddle the vertical direction and is on the skin-facing surface side of the absorbent main body. It is provided with a hydrophobic sheet arranged in the water-absorbing sheet and a sweat-absorbing sheet arranged on the skin-facing surface side of the hydrophobic sheet.
In the region overlapping with the absorbent body in the thickness direction, the bonding strength of the first bonding region in which the sweat-absorbing sheet and the hydrophobic sheet are bonded is such that the hydrophobic sheet and the surface sheet are bonded. 2 Disposable diapers that are stronger than the joint strength in the joint area. The disposable diaper according to claim 1, wherein the surface sheet has a distance between fibers larger than the distance between fibers of the sweat-absorbing sheet. The disposable diaper according to claim 1 or 2, wherein the surface sheet has an uneven shape on the surface facing the skin. In the sweat-absorbing sheet, the inner end in the vertical direction is located at the same position as the inner end in the vertical direction of the hydrophobic sheet, or is located outward in the vertical direction from the inner end of the hydrophobic sheet. The disposable diaper according to any one of claims 1 to 3. In the first joining region, the inner end in the vertical direction is located at the same position as the inner end in the vertical direction of the second joining region or inward from the inner end of the second joining region. The disposable diaper according to any one of claims 1 to 4. An elastic region formed by elastic members arranged in the laterally extended state is formed on the dorsal portion.
In the dorsal portion, the region where the hydrophobic sheet and the surface sheet overlap in the thickness direction and the region at the same position in the vertical direction are the central portion where the absorbent main body is located and the vertical direction of the absorbent main body. It is divided into a pair of side portions located laterally outward from each of the both side edges along the above.
The disposable diaper according to any one of claims 1 to 5, wherein the central portion has a lower lateral elongation stress as compared with each side portion. The absorbent body has leak-proof cuffs on both sides of the absorbent body facing the skin along the vertical direction.
The disposable diaper according to any one of claims 1 to 6, wherein the joint strength of the cuff joint region between the leak-proof cuff and the hydrophobic sheet is larger than the joint strength of the second joint region. The dorsal end of the absorbent body has a free end fixing portion in which the free end of the leak-proof cuff is fixed on the skin-facing surface of the surface sheet.
The hydrophobic sheet extends to a region located inward in the vertical direction from the free end fixing portion arranged in the innermost direction in the horizontal direction of the leak-proof cuff and is joined to the leak-proof cuff. The disposable diaper according to claim 7. The disposable diaper according to any one of claims 1 to 8, wherein the sweat-absorbing sheet has lower hydrophilicity on the side facing the skin than on the side facing the non-skin. The contact angle between the skin-facing surface of the sweat-absorbing sheet and the ion-exchanged water is 90 ° or more, and the contact angle between the non-skin-facing surface of the sweat-absorbing sheet and the ion-exchanged water is smaller than 90 °, claims 1 to 9. Disposable diaper according to any one item.

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