JP7187352B2 - absorbent article - Google Patents

Description

TECHNICAL FIELD The present invention relates to an absorbent article intended to reduce stuffiness.

Most of absorbent articles such as disposable diapers and sanitary napkins have a liquid-impermeable sheet on the back side of the absorbent body, so they do not have excellent breathability in the thickness direction. For this reason, stuffiness on the inner side (body surface side) of the absorbent article has conventionally been regarded as a problem (see Patent Documents 1 and 2, for example).

The stuffiness of the absorbent article can be improved by improving the breathability of the material. See Patent Documents 1 and 2).

However, the stuffiness caused by the moisture in the air contacting the body surface before sweating cannot be improved by sweat absorption.

JP 2009-082482 A JP 2009-056142 A

Therefore, the main object of the present invention is to reduce stuffiness while wearing an absorbent article.

The absorbent article that solves the above problems is as follows.
<First Aspect>
It has an absorbent body extending from the front side of the center in the front-back direction to the rear side of the center in the front-back direction, a liquid-permeable top sheet covering the front side of the absorbent body, and a liquid-impermeable sheet covering the back side of the absorbent body. ,
Having a first portion positioned forward of the front end of the absorbent body and a second portion positioned rearward of the rear end of the absorbent body,
The first part and the second part do not have an absorber,
At least one of the first portion and the second portion is laminated with a plurality of sheet layers having the liquid-impermeable sheet and having air permeability on the front side thereof, or the liquid-impermeable A plurality of air-permeable sheet layers having no sheet are laminated, and an elastic member is provided between the plurality of sheet layers,
Having a trunk gather part that is contracted in the width direction by contraction of the elastic member and that is expandable in the width direction,
In absorbent articles,
The plurality of sheet layers in the trunk gather portion have an exposed surface exposed to the outside of the product and a non-exposed surface not exposed to the outside of the product, and aggregates of microfibrous cellulose are attached only to the non-exposed surface. having a hygroscopic part,
An absorbent article characterized by:

(Effect)
A typical absorbent article often has waist gathers in a first portion positioned forward of the front end of the absorbent body and a second portion positioned rearward of the rear end of the absorbent body. Here, the absorbent body generally has hygroscopicity, and in particular when it contains a superabsorbent polymer, the superabsorbent polymer has high hygroscopicity. Therefore, in the portion having the absorbent body, the dampness can be reduced by the hygroscopic action of the absorbent body. never. In spite of this, the body gathers have a high degree of adhesion to the surface of the body, so they tend to get stuffy.

Therefore, in the present absorbent article, a plurality of sheet layers in the body gather portion are provided with a moisture absorbing portion to which aggregates of microfibrous cellulose adhere. The aggregate of microfibrous cellulose can be obtained by applying a dispersion of microfibrous cellulose to the sheet layer and then drying the sheet layer. . Therefore, by adhering aggregates of microfibrous cellulose to the body gathers as in the present absorbent article, it is possible to reduce stuffiness in the body gathers, which has not been conventionally prevented from getting stuffy.

In addition, since the aggregate of microfibrous cellulose is hard, if it is simply provided at an arbitrary site, it may worsen the feeling of wearing. However, in the present absorbent article, since the aggregates of microfibrous cellulose are provided only on the non-exposed surfaces of the plurality of sheet layers in the waist gather portion, they do not come into direct contact with the skin. Not only that, the sheet layer of the body gather part is compressed in the width direction due to the compression of the material and the folds formed accordingly, compared to the sheet layer of the non-gather part, both in the state of natural length and in the worn state. Stiffness (that is, cushioning) is increased. This increase in thickness and stiffness thus masks the stiffness of the aggregates of microfibrous cellulose. Therefore, in the present absorbent article, it is possible to obtain a high hygroscopic effect due to the aggregation of the microfibrous cellulose, while reducing the hardness of the touch due to the aggregation of the microfibrous cellulose.

<Second Aspect>
The hygroscopic portion is provided with a vertically striped pattern that is continuous in the front-rear direction and intermittent in the width direction, where the microfibrous cellulose assembly adheres to the hygroscopic portion.
The absorbent article of the first aspect.

(Effect)
It is preferable that the aggregates of microfibrous cellulose adhere to a wide area in consideration of moisture absorption performance. However, since aggregates of microfibrous cellulose are hard, if they are continuous in the direction of stretching, there is a risk that the stretchability of the trunk gather portion will be reduced. Therefore, if it is provided in the form of vertical stripes as in the present absorbent article, it is preferable because the fit of the waist gathered portion is less likely to deteriorate.

<Third Aspect>
The hygroscopic portion is provided only on the facing surface of at least one of the sheet layers adjacent to each other with the elastic member interposed therebetween. is joined with a hot-melt adhesive except for the part overlapping the attachment part of the aggregate of shaped cellulose,
The absorbent article of the second aspect.

(Effect)
When sheet layers adjacent to each other with an elastic member sandwiched therebetween are joined by a hot-melt adhesive, a dispersion of microfibrous cellulose is applied in order to form a moisture absorbing portion on the opposing surfaces of the adjacent sheet layers. Adhesion may be hindered depending on the positional relationship between the hot-melt adhesive and the hot-melt adhesive. On the other hand, in the present absorbent article, the adjacent sheet layers are bonded with a hot-melt adhesive except for the portion overlapping the adhered portion of the aggregate of microfibrous cellulose. sure to be done. In addition, in the trunk gather portion of the present absorbent article, the joining of adjacent sheet layers is intermittent at least in the width direction. The positioned portions are contracted and swelled in opposite directions to form an air passage consisting of a pair of folds, and a moisture absorbing portion is formed only on the inner surface of this air passage. Therefore, the breathability in the trunk gather portion is increased, and the efficiency of contact with moisture in the air is improved, thereby improving the hygroscopicity of the hygroscopic portion.

<Fourth Aspect>
Having a crotch part including the center in the front-rear direction, a front body extending forward from the center in the front-rear direction, and a back body extending rearward from the center in the front-rear direction,
The back body has side flaps extending laterally of the absorbent body,
Having a connecting tape attached to the side flaps of the back body and detachably connected to the front body,
At least the second portion of the back body has the top sheet and the liquid-impermeable sheet,
Between the top sheet and the liquid-impermeable sheet in the second part, a stretchable sheet elastically stretchable in the width direction,
The stretchable sheet has the elastic member and the sheet layers adjacent to the front side and the back side of the elastic member,
The second part has a body gather part that is contracted in the width direction due to the contraction of the stretchable sheet and that can be stretched in the width direction.
It is a tape type disposable diaper,
wherein the hygroscopic part is provided on the stretchable sheet;
The absorbent article according to any one of the first to third aspects.

(Effect)
In a tape-type disposable diaper, it is known to provide a body gather portion by attaching an elastic sheet between the top sheet and the liquid-impermeable sheet in the second portion. Therefore, it is preferable to provide a moisture absorbing portion in the elastic sheet, since the moisture absorbing portion can be efficiently provided in a proper place.

<Fifth Aspect>
an outer body that constitutes at least the waist portion of the front body and the back body; an inner body that includes the absorber attached to the outer body so as to extend from the front body to the back body; a waist opening; A pants-type disposable diaper comprising leg openings,
The exterior body has the first portion and the second portion,
The first part and the second part are laminated with three or more sheet layers that do not have the liquid-impermeable sheet and have air permeability, and the outermost sheet layer and the intermediate sheet layer are laminated. An elastic member is provided between
Having the hygroscopic part only on the outer surface of the intermediate sheet layer in the region having three or more sheet layers,
The absorbent article according to any one of the first to third aspects.

(Effect)
The trunk gathers provided in the first portion and the second portion of the pants-type disposable diaper are generally formed in the outer body. Two sheet layers are sufficient when the body gathers are provided in the outer body. Additional sheet layers have been added to cover the front and rear ends of the interior body. In other words, the outer packaging of the pants-type disposable diaper has a region having three or more sheet layers. Therefore, by utilizing this, if the moisture absorbing portion is provided only on the outer surface of the intermediate sheet layer in the region having three or more sheet layers, the thickness of the inside (skin side) and the outside of the moisture absorbing portion can be secured by one or more layers. It is preferable because the hardness of the hygroscopic part can be easily hidden.

<Sixth Aspect>
The sheet layer having the moisture absorbing portion is a nonwoven fabric having a fineness of 1.6 to 6.0 dtex, a basis weight of 10 to 30 g/m ² and a thickness of 0.1 to 1.3 mm,
The adhesion amount of the microfibrous cellulose in the moisture absorbing part is 5 to 10 g/m ² ,
The absorbent article according to any one of the first to fifth aspects.

(Effect)
The basis weight of the microfibrous cellulose in the hygroscopic part can be appropriately determined, but considering the hygroscopicity and flexibility, the adhesion amount of the microfibrous cellulose in the hygroscopic part is preferably within this range.

ADVANTAGE OF THE INVENTION According to this invention, advantages, such as being able to reduce stuffiness during wearing of an absorbent article, are brought about.

Fig. 2 is a plan view showing the inner surface of the underpants-type disposable diaper in an unfolded state; Fig. 2 is a plan view showing the outer surface of the pants-type disposable diaper in an unfolded state; FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1; 3 is a cross-sectional view taken along line 3-3 of FIG. 1; FIG. (a) 4-4 cross-sectional view of FIG. 1, and (b) 5-5 cross-sectional view of FIG. 1 is a perspective view of a pants-type disposable diaper; FIG. Fig. 2 is a plan view showing the outer surface of the pants-type disposable diaper in an unfolded state; (a) 4-4 cross-sectional view of FIG. 7; and (b) 5-5 cross-sectional view of FIG. Fig. 2 is a plan view showing the inner surface of the tape-type disposable diaper in an unfolded state; Fig. 2 is a plan view showing the outer surface of the tape-type disposable diaper in an unfolded state; FIG. 10 is a cross-sectional view taken along line 6-6 of FIG. 9; FIG. 10 is a cross-sectional view taken along line 7-7 of FIG. 9; (a) 8-8 cross-sectional view of FIG. 9, (b) 9-9 cross-sectional view of FIG. 9, and (c) 10-10 cross-sectional view of FIG. (a) A plan view of an elastic sheet, (b) and (c) a sectional view of an elastic sheet. FIG. 4 is a plan view showing various patterns of adhered portions of aggregates of microfibrous cellulose in the moisture absorbing portion. FIG. 5 is a sectional view taken along line 5-5 in FIG. 1, showing another example; FIG. 8 is a sectional view taken along line 5-5 in FIG. 7, showing another example; FIG. 10 is a cross-sectional view taken along line 8-8 of FIG. 9, showing another example; It is sectional drawing which expands and shows the principal part of a gather part roughly. It is sectional drawing which expands and shows the principal part of a gather part roughly.

Examples of disposable wearing articles will be described in detail below with reference to the accompanying drawings. The dotted pattern portion in the cross-sectional view shows the adhesive as a joining means for joining each component located on the front side and the back side, and the hot melt adhesive solid, bead, curtain, summit or spiral coating, or pattern coating (transfer of hot-melt adhesive by letterpress method), etc. Alternatively, or together with this, the fixed portion of the elastic member is formed by coating the outer peripheral surface of the elastic member with a comb gun or Surewrap coating. be. Hot-melt adhesives include, for example, EVA-based, adhesive rubber-based (elastomer-based), olefin-based, and polyester-polyamide-based adhesives, and can be used without particular limitation. As a joining means for joining each constituent member, a means by material welding such as heat sealing or ultrasonic sealing can be used.

In addition, as the nonwoven fabric in the following description, a known nonwoven fabric can be appropriately used depending on the site and purpose. Constituent fibers of non-woven fabrics include, for example, synthetic fibers such as olefin-based, polyester-based, and polyamide-based fibers such as polyethylene or polypropylene (including composite fibers such as core-sheath fibers in addition to single-component fibers), as well as recycled rayon and cupra. Fibers, natural fibers such as cotton, etc., can be selected without particular limitation, and these can also be mixed and used. In order to increase the softness of the nonwoven fabric, it is preferable to use crimped fibers as the constituent fibers. In addition, even if the constituent fibers of the nonwoven fabric are hydrophilic fibers (including those made hydrophilic by a hydrophilic agent), they may be hydrophobic fibers or water-repellent fibers (water-repellent fibers made water-repellent by a water-repellent agent). including). In addition, nonwoven fabrics are generally classified into short fiber nonwoven fabrics, long fiber nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics, thermal bonded (air-through) nonwoven fabrics, and needle punched nonwoven fabrics, depending on the fiber length, sheet forming method, fiber bonding method, and laminate structure. Non-woven fabrics, point-bonded non-woven fabrics, laminated non-woven fabrics (including SSS non-woven fabrics in which the same or similar non-woven fabric layers are laminated, SMS non-woven fabrics in which different non-woven fabric layers are laminated, in which a meltblown layer is sandwiched between spunbond layers, SMMS non-woven fabrics, etc.), etc. However, any of these nonwoven fabrics can be used.

<Example of pants-type disposable diaper>
1 to 6 show pants-type disposable diapers. This pants-type disposable diaper includes a front outer body 12F forming a front body F, a rear outer body 12B forming a back body B, and a rear outer body 12B extending from the front outer body 12F through the crotch to the rear outer body 12B. and an interior body 200 provided inside the exterior bodies 12F and 12B, and both sides of the front exterior body 12F and both sides of the rear exterior body 12B are joined to form a side seal portion 12A. As a result, the opening formed by the front and rear ends of the exterior bodies 12F and 12B becomes a waist opening WO through which the wearer's torso passes, and the lower edges of the exterior bodies 12F and 12B and the interior body 200 on both sides in the width direction of the interior body 200. The portions surrounded by the side edges are leg openings LO through which the legs are passed. The inner body 200 is a part that absorbs and holds excrement such as urine, and the outer bodies 12F and 12B are parts that support the inner body 200 against the wearer's body. Symbol Y indicates the total length of the diaper in the unfolded state (the length in the front-rear direction from the edge of the waist opening WO of the front body F to the edge of the waist opening WO of the back body B), and the symbol X indicates the diaper in the unfolded state. shows the full width of

Further, the pants-type disposable diaper of this example forms a waist region T defined as a front-rear direction range (a front-rear direction range from the waist opening WO to the upper ends of the leg openings LO) having the side seal portions 12A, and the leg openings LO. It has an intermediate region L defined as a front-back direction range of the part (between the front-back direction region having the side seal portions 12A of the front body F and the front-back direction region having the side seal portions 12A of the back body B). The waist region T can be conceptually divided into a waist portion W forming the edge of the waist opening and a lower waist portion U below this. Usually, when there is a boundary where the elastic stress in the width direction WD changes in the waist region T (for example, the thickness or elongation rate of the elastic member changes), the waist opening WO side is the waist opening WO side of the boundary closest to the waist opening WO side. If there is no such boundary, the waist portion W is on the waist opening WO side of the absorber 56 or the inner body 200 . The length in the front-rear direction differs depending on the size of the product and can be determined as appropriate. For example, the waist portion W can be 15 to 40 mm, and the lower waist portion U can be 65 to 120 mm. On the other hand, both side edges of the intermediate region L are constricted in a U-shape or curvilinear shape along the circumference of the wearer's leg, and this is a portion into which the wearer's leg is inserted. As a result, the unfolded pants-type disposable diaper has a substantially hourglass shape as a whole.

(internal and external joints)
Fixing of the inner body 200 to the outer bodies 12F and 12B can be performed by means of material welding such as heat sealing or ultrasonic sealing, or hot melt adhesive. In the illustrated example, the hot-melt adhesive applied to the back surface of the inner body 200, that is, the back surface of the liquid-impermeable sheet 11 and the base portion 65 of the rising gather 60 in this case, is applied to the inner surfaces of the exterior bodies 12F and 12B. is fixed. The inner/outer joints 201 for fixing the inner body 200 and the outer bodies 12F and 12B can be provided almost entirely in the region where the two overlap. can.

(inner body)
The inner body 200 can take any shape, but is rectangular in the illustrated example. As shown in FIGS. 3 to 5, the inner body 200 comprises a body-side top sheet 30, a liquid-impermeable sheet 11, and an absorbent element 50 interposed therebetween. This is the main body part responsible for the absorption function. Reference numeral 40 denotes an intermediate sheet provided between the top sheet 30 and the absorbent element 50 in order to quickly transfer the liquid permeating the top sheet 30 to the absorbent element 50, and reference numeral 60 denotes an inner body. In order to prevent excrement from leaking to both sides of the body 200, the riser gathers 60 are shown extending from both sides of the inner body 200 so as to come in contact with the legs of the wearer.

(top sheet)
The top sheet 30 has the property of being permeable to liquid, and examples thereof include perforated or non-perforated non-woven fabrics and porous plastic sheets.

Both sides of the top sheet 30 may be folded back at the side edges of the absorbent element 50 , or may protrude laterally from the side edges of the absorbent element 50 without being folded.

The top sheet 30 can be fixed to a member adjacent to the back side by means of material welding, such as heat sealing or ultrasonic sealing, or hot-melt adhesive for the purpose of preventing misalignment with respect to the member on the back side. desirable. In the illustrated example, the top sheet 30 is fixed to the surface of the intermediate sheet 40 and the surface of the portion of the packaging sheet 58 located on the front side of the absorbent body 56 with a hot-melt adhesive applied to its back surface.

(intermediate sheet)
An intermediate sheet (also called a “second sheet”) 40 having a faster liquid permeation rate than the top sheet 30 can be provided in order to quickly transfer the liquid that has permeated the top sheet 30 to the absorbent body. The intermediate sheet 40 not only transfers the liquid to the absorbent body quickly to improve the absorption performance of the absorbent body, but also prevents the absorbed liquid from returning from the absorbent body to keep the top sheet 30 dry at all times. can be in a state of The intermediate sheet 40 can also be omitted.

As the intermediate sheet 40, a perforated or non-perforated nonwoven fabric, a porous plastic sheet, or the like can be used. In particular, an air-through nonwoven fabric is preferred because it is bulky. Composite fibers having a core-sheath structure are preferably used for the air-through nonwoven fabric. In this case, the resin used for the core may be polypropylene (PP), but polyester (PET) having high rigidity is preferable. The basis weight is preferably 20-80 g/m ² , more preferably 25-60 g/m ² . The thickness of the raw fibers of the nonwoven fabric is preferably 2.0 to 10 dtex. In order to make the non-woven fabric bulky, it is also preferable to use eccentric fibers, hollow fibers, or eccentric and hollow fibers whose core is not in the center as mixed fibers of all or part of the raw material fibers.

The intermediate sheet 40 in the illustrated example is shorter than the width of the absorbent body 56 and arranged in the center, but it may be provided over the entire width. The longitudinal length of the intermediate sheet 40 may be the same as the entire length of the diaper, the length of the absorbent element 50, or within a short length range centered on the liquid-receiving area.

The intermediate sheet 40 can be fixed to a member adjacent to the back side by means of material welding, such as heat sealing or ultrasonic sealing, or hot-melt adhesive for the purpose of preventing misalignment with respect to the member on the back side. desirable. In the illustrated example, the intermediate sheet 40 is fixed to the surface of the portion of the packaging sheet 58 located on the front side of the absorbent body 56 with a hot-melt adhesive applied to its back surface.

(liquid-impermeable sheet)
The material of the liquid-impermeable sheet 11 is not particularly limited, but examples thereof include plastic films made of olefin resins such as polyethylene and polypropylene, laminated nonwoven fabrics in which a plastic film is provided on the surface of nonwoven fabrics, and plastic films. A laminated sheet in which a nonwoven fabric or the like is laminated and joined to the sheet can be exemplified. For the liquid-impermeable sheet 11, it is preferable to use a liquid-impermeable and moisture-permeable material that is preferably used from the viewpoint of preventing stuffiness. Moisture-permeable plastic films include microporous plastic films obtained by kneading an inorganic filler into an olefin resin such as polyethylene or polypropylene, forming a sheet, and then stretching the sheet in a uniaxial or biaxial direction. is widely used. In addition, by applying heat and pressure to reduce the voids in the fibers to improve leakproofness, and by coating with superabsorbent resin, hydrophobic resin, and water repellent agents, we have made it possible without using a plastic film. A liquid-impermeable nonwoven fabric can also be used as the liquid-impermeable sheet 11 .

The liquid-impermeable sheet 11 has a width that can be accommodated on the back side of the absorbent element 50 as shown in the figure. It can also extend to both sides. It is appropriate that the width of this extended portion is about 5 to 20 mm on each side.

(Getting up gathers)
The riser gathers 60 extend along both sides of the inner body 200 over the entire front-rear direction LD, and are provided to contact the wearer's legs to prevent side leakage. This includes what is called

The rising gathers 60 shown in FIGS. 3 and 4 stand up from the sides of the inner body 200 to the front side. The riser gathers 60 have a root portion that stands obliquely toward the center in the width direction, and a portion that is closer to the tip than the middle portion that stands obliquely toward the outside in the width direction, but are not limited to this. However, it is possible to make appropriate modifications such as a structure in which the entire structure stands on the center side in the width direction.

More specifically, the rising gathers 60 of the first structure are obtained by folding a band-shaped gathered nonwoven fabric 62 having a length equal to the length of the inner body 200 in the front-rear direction in the width direction WD at the leading end to fold it in two. A plurality of slender gathering elastic members 63 are fixed in a stretched state along the longitudinal direction at intervals in the width direction WD between the folded portions and the adjacent sheets. A base end portion of the rising gathers 60 located on the opposite side to the tip portion (the end portion on the side opposite to the sheet folded portion in the width direction WD) is fixed to the side portion of the inner body 200 on the back side of the liquid-impermeable sheet 11. The base portion 65 is formed as a flattened base portion 65, and the portion other than the base portion 65 is a body portion 66 extending from the base portion 65 (portion on the folded portion side). Further, the main body portion 66 is composed of a root side portion toward the center in the width direction and a tip side portion folded back from the tip of the root side portion to the outside in the width direction. Although this example is a surface contact type rising gather 60, a line contact type rising gather 60 that is not folded outward in the width direction can also be employed. Both ends of the main body portion 66 in the front-rear direction are laid down portions 67 fixed to the side surfaces of the top sheet 30 in the laid-down state, while an intermediate portion in the front-rear direction positioned therebetween is not fixed. A gathered elastic member 63 extending in the front-rear direction LD is fixed to the free portion 68 in a stretched state.

As the gathered nonwoven fabric 62, a nonwoven fabric subjected to a water-repellent treatment with silicone or the like as necessary can be suitably used, and the fiber basis weight is preferably about 10 to 30 g/m ² . A thread rubber or the like can be used as the gather elastic member 63 . When spandex thread rubber is used, the thickness is preferably 470 to 1240 dtex, more preferably 620 to 940 dtex. The elongation rate when fixed is preferably 150 to 350%, more preferably 200 to 300%. Also, as shown in the figure, a waterproof film 64 can be interposed between the gathered nonwoven fabrics 62 folded in two. In this case, the gathered nonwoven fabrics 62 can be partially omitted where the waterproof film 64 exists. can also

The number of gather elastic members 63 provided in the free portion of the rising gathers 60 is preferably 2-6, more preferably 3-5. A suitable arrangement interval 60d is 3 to 10 mm. With this configuration, the area in which the gather elastic member 63 is arranged can easily come into contact with the skin. The gather elastic member 63 may be arranged not only on the tip side but also on the base side.

In the free portion 68 of the rising gather 60, the inner layer and the outer layer of the gathered nonwoven fabric 62 are adhered together, and the gathered elastic member 63 sandwiched between them is fixed by hot-melt adhesive, heat sealing, ultrasonic wave, or the like by various coating methods. At least one of fixing means by material welding such as a seal can be used. If the inner layer and the outer layer of the gathered nonwoven fabric 62 are entirely adhered together, the flexibility is impaired, so it is preferable that the portions of the gathered elastic member 63 other than the adhered portion are not adhered or adhered weakly. In the illustrated example, the hot-melt adhesive is applied only to the outer peripheral surface of the gathered elastic member 63 by applying means such as a comb gun or a sure wrap nozzle, and the gathered elastic member 63 is sandwiched between the inner layer and the outer layer of the gathered nonwoven fabric 62 . The gathered elastic member 63 is fixed to the inner layer and the outer layer of the gathered nonwoven fabric 62, and the inner layer and the outer layer of the gathered nonwoven fabric 62 are fixed only by the hot-melt adhesive applied to the outer peripheral surface of the. there is

In addition, for fixing the waterproof film 64 incorporated in the rising gather 60 and the gathered nonwoven fabric 62, fixing the lodged portion 67 to the side surface of the inner body 200, hot melt adhesive by various coating methods, heat sealing, etc. At least one of material welding means such as ultrasonic sealing can be used. In the illustrated example, a slot application of hot melt adhesive is used to secure the waterproof film 64 . Further, the lodging portion 67 in the illustrated example is fixed by a combination of hot-melt adhesive and material welding, but it is also possible to fix these by using only one of them.

The base portion 65 of the rising gathers 60 can be fixed to an appropriate member such as the top sheet 30, the liquid-impermeable sheet 11, the absorbent element 50, etc. of the inner body 200. FIG.

In the rising gathers 60 configured as described above, both ends of the main body portion 66 in the front-rear direction are fixed so as not to stand upright, whereas a non-fixed free portion 68 is provided between them. Only the free portion 68 stands up so as to abut on the body side as shown in FIG. In particular, when the base portion 65 is positioned on the back side of the inner body 200, the rising gathers 60 stand up so as to open outward in the width direction in the crotch portion and its vicinity, so that the rising gathers 60 come into surface contact with the leg circumferences. and the fit improves.

(absorbing element)
The absorbent element 50 has an absorbent body 56 and a wrapping sheet 58 that wraps the entire absorbent body 56 . The packaging sheet 58 can also be omitted.

(Absorber)
Absorbent body 56 can be formed from an aggregate of fibers. The filament assembly may be a filament assembly obtained by laminating short fibers such as cotton pulp or synthetic fibers, or by opening tows (fiber bundles) of synthetic fibers such as cellulose acetate as necessary. can also be used. The fiber basis weight can be, for example, about 100 to 300 g/m ² when piling up cotton-like pulp or short fibers, and for example, about 30 to 120 g/m ² for filament aggregates. can be done.

The absorbent body 56 may have a rectangular shape, but as shown in FIG. 1, it has a front end, a rear end, and a constricted portion 56N positioned between them and narrower than the front and rear ends. The hourglass shape is preferable because the absorber 56 itself and the sit-up gathers 60 fit better around the legs.

(superabsorbent polymer particles)
Absorbent body 56 may contain superabsorbent polymer particles in part or in its entirety. Superabsorbent polymer particles include "powder" in addition to "particles". As the superabsorbent polymer particles, those used for this type of disposable diaper can be used as they are.

(packaging sheet)
When the packaging sheet 58 is used, tissue paper, particularly crepe paper, non-woven fabric, poly-laminated non-woven fabric, a perforated sheet, or the like can be used as the material. However, it is desirable that the sheet is such that the superabsorbent polymer particles do not escape. When non-woven fabric is used instead of crepe paper, hydrophilic SMS non-woven fabric (SMS, SSMMS, etc.) is particularly suitable, and its material can be polypropylene, polyethylene/polypropylene composite, or the like. The basis weight is preferably 5 to 40 g/m ² , particularly 10 to 30 g/m ² .

(Exterior body)
The exterior bodies 12F and 12B are composed of a front exterior body 12F that constitutes the front body F and a rear exterior body 12B that constitutes the back body B. The front exterior body 12F and the rear exterior body 12B are not continuous on the crotch side and are spaced apart in the front-rear direction LD (exterior split type). This separation distance 12d can be, for example, approximately 150 to 250 mm. Further, as shown in FIGS. 7 and 8, the outer body 12 may be an integral body extending from the front body F to the back body B through the crotch (exterior integrated type).

The outer bodies 12F and 12B have a waist portion corresponding to the waist region T in the front-rear direction. In this example, the front exterior body 12F does not have a portion corresponding to the intermediate region L, but the rear exterior body 12B has a buttock cover portion C extending from the waist region T toward the intermediate region L side. is doing. Although not shown, the front exterior body 12F may also be provided with an inguinal cover portion extending from the waist region T toward the intermediate region L side, or may be provided with a groin cover portion but not with a buttock cover portion. It is not necessary to provide a portion corresponding to the intermediate region L on both sides of the rear exterior body 12B. In the illustrated example, the lower edge of the buttock cover portion C is formed in a straight line along the width direction WD similarly to the lower edge of the front exterior body 12F, but is positioned closer to the waist opening as it goes outward in the width direction. It can also be a curve that

As shown in FIGS. 4 and 5, the exterior bodies 12F and 12B are formed by joining an outer sheet layer 12S and an inner sheet layer 12H by joining means such as hot-melt adhesive or welding. The sheet material forming the outer sheet layer 12S and the sheet material forming the inner sheet layer 12H may be a single common sheet material as in the example shown in FIG. It can also be a sheet material. That is, in the former case, the inner sheet layer 12H and the outer sheet layer 12S are respectively formed by the inner portion and the outer portion of the single sheet material folded back at the edge of the waist opening WO (which may be the edge on the crotch side). be done. The former example has the advantage that the amount of material used for the sheet layer is small, and the latter example has the advantage that the inner sheet layer 12H and the outer sheet layer 12S are less likely to be misaligned when they are bonded together. Further, in the example shown in FIG. 8, the sheet material forming the inner sheet layer 12H extends only to the edge of the waist opening WO, but the sheet material forming the outer sheet layer 12S extends only to the edge of the inner sheet layer 12H. The sheet material is folded around the edge of the waist opening WO, and the folded sheet layer 12r extends to the end of the interior body 200 on the waist opening side. Although not shown, a separate sheet layer may be added to the inner side of the inner sheet layer 12H in order to cover the end of the inner body 200 on the waist opening side without providing the folded sheet layer 12r.

The sheet material used for the outer sheet layer 12S and the inner sheet layer 12H is not particularly limited ^, but is preferably a non-woven fabric. Preferably, a 1.3 mm non-woven fabric is used.

(stretchable area/non-stretchable area)
The exterior bodies 12F and 12B are provided with elongated elastic members 15 to 18 such as rubber threads between the outer sheet layer 12S and the inner sheet layer 12H in order to improve fit around the wearer's waist. An elastic region A2 is formed which elastically expands and contracts in the width direction WD with 15 to 18 expansion and contraction. In this stretchable region A2, the outer sheet layer 12S and the inner sheet layer 12H shrink in accordance with the contraction of the elastic members in the natural length state, forming wrinkles or folds and stretching in the longitudinal direction of the elastic members 15-18. Then, the outer sheet layer 12S and the inner sheet layer 12H can be stretched up to a predetermined elongation rate at which they are completely stretched without wrinkles. That is, the stretchable region A2 is a gathered portion that is contracted in the width direction WD due to the contraction of the elastic members 15 to 18 and that is expandable in the width direction WD. As the elastic members 15-18, either synthetic rubber or natural rubber may be used.

For bonding the outer sheet layer 12S and the inner sheet layer 12H in the exterior bodies 12F and 12B, and fixing the elastic members 15 to 18 sandwiched between them, hot melt adhesives, heat sealing, and ultrasonic sealing by various coating methods are used. At least one of fixing means by material welding such as welding can be used. Firmly fixing the entire surfaces of the outer casings 12F and 12B will damage the flexibility, so it is preferable that the elastic members 15 to 18 are not adhered or weakly adhered to the portions other than the adhered portions. In the illustrated example, the hot-melt adhesive is applied only to the outer peripheral surfaces of the elastic members 15 to 18 by applying means such as a comb gun or a sure wrap nozzle, and the elastic members 15 to 18 are sandwiched between the sheet layers 12S and 12H. The elastic members 15 to 18 are fixed to both the sheet layers 12S and 12H and the two sheet layers 12S and 12H are joined by only the hot-melt adhesive applied to the outer peripheral surface of the sheet layers 12S and 12H. In this case, as shown in FIG. 19, pleats PL extending in a direction perpendicular to the stretching direction are alternately formed on the inside and outside of the gathered portion in the worn state. The folds have a slightly compressed shape at the fixed positions of the elastic members 15-18, and have a bulging shape between the adjacent elastic members 15-18, which is larger than the fixed positions of the elastic members 15-18. The elastic members 15 to 18 can be fixed to the outer sheet layer 12S and the inner sheet layer 12H only at both ends of the stretchable area A2 in the stretching direction. In this case, as shown in FIGS. 20(a) and 20(b), if the joining between the sheet layers 12S and 12H is intermittent at least in the width direction WD, in the worn state where the gathers shrink to some extent, both Portions located between the joints of the sheet layers 12S and 12H contract and swell in opposite directions to form an air passage AR comprising a pair of pleats PL.

More specifically, a plurality of waist elastic members 17 extend vertically between the outer sheet layer 12S and the inner sheet layer 12H in the waist portion W of the exterior bodies 12F and 12B so as to be continuous over the entire width direction WD. installed with a gap. One or more of the waist elastic members 17 disposed in the region adjacent to the lower waist portion U may overlap the inner body 200 or may overlap the inner body 200 in the width direction. Except for the part, it may be provided on both sides in the width direction. The waist elastic member 17 has a thickness of 155 to 1880 dtex, especially about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , especially 0.1 to 1.5 mm 2 . 0 mm ² ) are preferably provided at intervals of 4 to 12 mm, and the elongation rate of the waist portion W in the width direction WD is 150 to 400%, particularly about 220 to 320%. It is preferable to have In addition, the waist portion W does not need to use the waist portion elastic member 17 having the same thickness or the same elongation rate in all of the waist portion W in the front-rear direction LD. The thickness and elongation rate may be different.

In addition, a plurality of waist lower elastic members 15 and 18 made of elongated elastic members are spaced apart in the vertical direction between the outer sheet layer 12S and the inner sheet layer 12H in the lower waist portion U of the outer bodies 12F and 12B. It is installed with a gap.

The waist lower elastic members 15 and 18 have a thickness of 155 to 1880 dtex, especially about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , especially 0.1 to 1.5 mm 2 . 1.0 mm ² ) are preferably provided at intervals of 1 to 15 mm, particularly 3 to 8 mm, at intervals of 5 to 30, and the elongation rate of the lower waist portion U in the width direction WD is 200 to 350%. , particularly preferably about 240 to 300%.

In addition, a plurality of cover section elastic members 16 made of elongated elastic members are attached at intervals in the vertical direction between the outer sheet layer 12S and the inner sheet layer 12H in the buttock cover section C of the rear exterior body 12B. It is

The cover elastic member 16 has a thickness of 155 to 1880 dtex, particularly about 470 to 1240 dtex (in the case of synthetic rubber. In the case of natural rubber, the cross-sectional area is 0.05 to 1.5 mm ² , particularly 0.1 to 1.0 mm. ² ) are preferably provided at intervals of 5 to 40 mm, particularly 5 to 20 mm, and the elongation rate of the cover portion in the width direction WD is 150 to 300%, particularly 180 to 260. % is preferred.

In the case of providing an inguinal cover portion on the front side exterior body 12F, similarly, a cover portion elastic member can be provided.

When the elastic members 15, 16, 18 are provided in the front-back direction range having the absorber 56, as in the illustrated example of the waist lower portion U and the buttocks cover portion C, the width direction of the absorber 56 is partially or entirely In order to prevent contraction of the WD, the middle portion in the width direction including part or all of the portion overlapping the absorbent body 56 in the width direction WD (preferably including substantially the entire inner/outer joint portion 201) is defined as a non-stretchable region A1, Both sides in the width direction are set as stretchable regions A2. Although it is preferable that the waist portion W is the stretchable region A2 over the entire width direction WD, a non-stretchable region A1 may be provided in the middle of the widthwise direction similarly to the lower waist portion U.

The stretchable region A2 and the non-stretchable region A1 supply elastic members 15 to 18 between the inner sheet layer 12H and the outer sheet layer 12S, and the elastic members 15, 16, and 18 are stretched at least in the stretchable direction in the stretchable region A2. The elastic members 15, 16, and 18 are fixed at both ends with a hot melt adhesive, the non-stretchable region A1 is not fixed, and the elastic members 15, 16, and 18 are fixed at one point in the middle of the non-stretchable region A1. Cut by pressurization and heating, or cut almost all of the elastic members 15, 16, 18 finely by pressurization and heating, leaving the stretchability in the stretchable region A2 and eliminating the stretchability in the non-stretchable region A1. can be built. In the former case, as shown in FIG. 4 , in the non-stretchable region A1, the uncut portion continuous from the elastic members 15, 16, and 18 of the stretchable region A2 is shrunk to its natural length as the unnecessary elastic member 19 alone. It will remain between the outer sheet layer 12S and the inner sheet layer 12H. In the latter case, although not shown, the cut residue continuing from the elastic members 15, 16, 18 of the elastic area A2 and the elastic members 15 of both elastic areas A2 , 16 and 18, the cut piece of the elastic member discontinuous remains between the outer sheet layer 12S and the inner sheet layer 12H as the unnecessary elastic member 19 alone in a state of shrinking to its natural length.

In a pants-type disposable diaper with an exterior that is divided into two parts, the interior body 200 is exposed between the front exterior body 12F and the rear exterior body 12B. A cover nonwoven fabric 20 covering the back surface of the inner body 200 is provided from between the front outer body 12F and the inner body 200 to between the rear outer body 12B and the inner body 200. - 特許庁

The range in the front-rear direction of the cover nonwoven fabric 20 is not particularly limited as long as it has a portion overlapping the front exterior body 12F and the rear exterior body 12B. The rear exterior body 12B and the interior body 200 may extend in the front-rear direction LD all the way to the end. It may extend in the front-rear direction LD to an intermediate position in the front-rear direction of the overlapping region.

The widthwise range of the cover nonwoven fabric 20 is a range capable of hiding the rear surface exposed portion of the liquid-impermeable sheet 11 . For this reason, in the illustrated example, since the liquid-impermeable sheet 11 is exposed between the base ends of the left and right upright gathers 60 , the liquid-impermeable sheet 11 is exposed from the back side of the base end of at least one of the upright gathers 60 to the base end of the other upright gather 60 . A cover nonwoven fabric 20 is provided so as to cover the width direction range up to the back side of the part. Alternatively, instead of covering the back sides of the base ends of the raised gathers 60 at both ends in the width direction of the cover nonwoven fabric 20, the gathers nonwoven fabric 62 may cover the back sides at both ends in the width direction of the cover nonwoven fabric 20. It is possible to conceal the liquid-impermeable sheet 11 with the gathered nonwoven fabric 62 .

<Example of tape-type disposable diaper>
9 to 14 show an example of a tape-type disposable diaper, where X in the figures indicates the total width of the diaper excluding the connecting tape, and Y indicates the total length of the diaper. This tape-type disposable diaper includes an absorbent body 56 extending from a front body F to a back body B, a liquid-permeable top sheet 30 covering the front side of the absorbent body 56, and a liquid-impermeable top sheet 30 covering the back side of the absorbent body 56. It has a sheet 11 and a pair of side flaps SF extending laterally from the side edges of the absorber 56 . A constriction along the circumference of the leg is formed in the middle of the side flap SF in the front-rear direction, and a connecting tape 13 is provided on the rear side of the constriction. In addition, the present tape-type disposable diaper includes a first portion 91 which is positioned forward of the front end of the absorbent body 56 and does not have the absorbent body 56, and a first portion 91 which is positioned rearward of the rear end of the absorbent body 56 and has the absorbent body 56. It has a second portion 92 that it does not have.

The rear surface of the liquid-impermeable sheet 11 is covered with an exterior nonwoven fabric 21 . The basis weight and thickness of the exterior non-woven fabric 21 can be appropriately determined, but in general, it is preferable that the basis weight is 15 to 30 g/m ² and the thickness is 0.2 to 1.2 mm. The exterior nonwoven fabric 21 extends to the periphery of the diaper, and the liquid-impermeable sheet 11 extends to the front and rear edges of the diaper in the front-rear direction, and the side edges of the absorber 56 and the exterior nonwoven fabric 21 side in the width direction. Although it extends to the edge, the exterior nonwoven fabric 21 can be only part of the front-rear direction LD, only part of the width direction WD, or both, if necessary. . For example, when a portion of the liquid-impermeable sheet 11 is covered with another material such as a gathered nonwoven fabric, the outer nonwoven fabric 21 may not be provided on that portion.

The top sheet 30 extends from the front end to the rear end of the product in the front-rear direction, and extends laterally from the absorbent body 56 in the width direction WD. If necessary, such as when the top sheet 30 is located on the center side in the width direction, the width of the top sheet 30 may be made shorter than the total width of the absorbent body 56, and other suitable modifications may be made.

It is desirable that the liquid-impermeable sheet 11 extends in the same or wider range than the absorbent body 56 in the front-rear direction LD and the width direction WD. A structure in which the end portions of the absorber 56 are not covered in the front-rear direction LD and the width direction WD may also be employed.

In addition, as in the case of pants-type disposable diapers, the absorbent body 56 can be interposed between the top sheet 30 and the liquid-impermeable sheet 11 as an absorbent element wrapped in a wrapping sheet, and the absorbent body 56 can be interposed between the top sheet and the absorbent element. can be provided with an intermediate sheet 40 . The illustrated intermediate sheet 40 is shorter than the width of the absorbent element 50 and centrally located, but may be provided over the entire width. The longitudinal length of the intermediate sheet 40 may be the same as the entire length of the diaper, the length of the absorbent element 50, or within a short length range centered on the liquid-receiving area.

On both sides of the top sheet 30 in the width direction WD, rise gathers 60 standing up toward the wearer's skin are provided in order to prevent excrement from moving laterally along the top sheet 30 and prevent so-called side leakage. preferably. Of course, the rising gathers 60 can be omitted.

When adopting the rising gathers 60, the structure is not particularly limited, and any known structure can be adopted. The rising gathers 60 of the illustrated example include a base portion 65 fixed to an area including the side flaps, a body portion 66 extending from the base portion, and both ends of the body portion 66 in the front-rear direction fixed in a laid down state. A gathered nonwoven fabric 62 having a portion 67 and a non-fixed raised portion 68 positioned between the front and rear fallen portions 67 of the body portion 66, and a gathered elastic member 63 fixed to at least the tip of the raised portion 68. It has become. As the gathered nonwoven fabric 62 and the gathered elastic members 63, the same materials as those used for the pants-type disposable diaper can be used. As shown in FIGS. 9 and 11, a plurality of gathering elastic members 63 may be provided, or a single gathering elastic member 63 may be provided.

The inner surface of the gathered nonwoven fabric 62 has a joining start end in the width direction WD on the side of the top sheet 30, and the portion outside the joining end in the width direction is the inner surface of each side flap SF, that is, in the illustrated example, it is liquid impermeable. The side portions of the sheet 11 and the side portions of the exterior nonwoven fabric 21 located on the widthwise outer side thereof are joined by a hot-melt adhesive or the like.

Around the legs, the width direction inner side from the joining start end of the rising gathers 60 is fixed on the top sheet 30 at both ends in the front and back direction of the product, but the portion in between is a non-fixed free portion. It rises due to the contractile force of the elastic member 63 and comes to adhere to the surface of the body.

A side elastic member 69 made of an elongated elastic member such as rubber thread is fixed to each side flap SF while being stretched in the front-rear direction LD. Configured as a gather. The side elastic member 69 is provided between the gathered nonwoven fabric 62 and the liquid-impermeable sheet 11 at the width direction outer side near the joining start end of the joined portion of the gathered nonwoven fabric 62, as shown in the illustrated example, and also at the side flap SF. It can also be provided between the liquid-impermeable sheet 11 and the exterior nonwoven fabric 21 . A plurality of side elastic members 69 may be provided on each side as in the illustrated example, or only one may be provided on each side.

The planar gather is a portion where the contractile force of the side elastic member 69 acts (the portion where the side elastic member 69 is illustrated in the figure). Therefore, in addition to the structure in which the side elastic members 69 exist only in the planar gathers, the side elastic members 69 exist on the front side, the rear side, or both sides of the planar gathers, but the side elastic members 69 exist in areas other than the planar gathers. If the member is finely cut at one point or multiple points, or is not fixed to the sheet sandwiching the side elastic member 69, or both, the contractile force will not act on the part other than the planar gathers. Also included is a structure in which the contractile force of the side elastic member 69 acts only on the planar gather portion without (substantially equivalent to not providing an elastic member).

The connecting tape 13 in the illustrated example includes a sheet base material forming a tape mounting portion 13C fixed to the side portion of the diaper, a tape main body portion 13B projecting from the tape mounting portion 13C, and a tape main body portion 13B in the sheet base material. and a locking portion 13A for the front body F provided in the middle portion in the width direction of the front body F, and the front end side of the locking portion 13A serves as a knob portion. The tape attaching portion 13C of the connecting tape 13 is sandwiched between the gathering nonwoven fabric 62 forming the inner layer of the side flap and the exterior nonwoven fabric 21 forming the outer layer, and is adhered to both nonwoven fabrics 62, 12 with a hot-melt adhesive. Also, the engaging portion 13A is joined to the inner surface of the tape body portion 13B with an adhesive.

A hook member (male member) of a mechanical fastener (surface fastener) is suitable for the locking portion 13A. The hook material has a large number of engaging projections on its outer surface side. The shapes of the engaging protrusions are (A) L-shaped, (B) J-shaped, (C) mushroom-shaped, (D) T-shaped, and (E) double J-shaped (J-shaped). , but any shape may be used. Of course, an adhesive layer can also be provided as a locking portion of the connecting tape 13 .

Further, as the sheet base material forming the tape attachment portion 13C to the tape body portion 13B, nonwoven fabric, plastic film, poly-laminated nonwoven fabric, paper, or a composite material thereof can be used.

When wearing the diaper, the connecting tape 13 is locked to the outer surface of the front body F in a state where the side flaps SF of the back body B are superimposed on the outside of the side flaps SF of the front body F. The position and size of the locking portion of the connecting tape 13 can be determined arbitrarily.

It is preferable to provide a target sheet 24 having a target for facilitating the fastening at the fastening portion of the connecting tape 13 on the front body F. As shown in FIG. When the engaging portion 13A is made of a hook material, the target sheet 24 is a film-type target sheet having a film layer and an engaging layer provided on the entire outer surface thereof, with which the hooks of the engaging portion 13A are detachably engaged. can be preferably used. In this case, the engaging layer may be a thread-woven mesh having loops attached to the film layer, or a thermoplastic resin non-woven fabric layer that is intermittently sealed by ultrasonic sealing to the film layer. A non-woven fabric that is attached to the top and forms loops of non-woven fabric fibers is known, but any of them can be preferably used. A filmless type target tape having no film layer, which is obtained by embossing a thermoplastic resin nonwoven fabric, can also be used. In these target tapes, the connecting tapes 13 are joined by the hooks of the connecting tapes 13 being entangled or caught in the loops.

When the engaging portion 13A is an adhesive layer, it is possible to use a sheet substrate made of a plastic film with a smooth surface that is rich in adhesiveness and whose surface has been subjected to release treatment.

Further, when the engaging portion of the connecting tape 13 on the front body F is made of nonwoven fabric, for example, when the exterior nonwoven fabric 21 is provided as shown in the figure, and the engaging portion 13A of the connecting tape 13 is made of hook material, Alternatively, the target sheet 24 may be omitted, and the hook material may be entwined with the nonwoven fabric of the exterior nonwoven fabric 21 for engagement. In this case, the target sheet 24 may be provided between the exterior nonwoven fabric 21 and the liquid impermeable sheet 11 .

A stretchable sheet 70 that elastically expands and contracts in the width direction WD is attached to a region of the back body B that includes between the left and right connecting tapes 80 . It is a gathered part that can be stretched. The stretchable sheet 70 may be located only on the second portion 92, but if it is arranged so as to extend from the second portion 92 to the rear end of the absorbent body 56 as shown in the figure, the absorbent body 56 will be stretched. It is preferred because the rear end is firmly pressed against the body.

The stretchable sheet 70 may be made of an elastic film, but preferably has air permeability. In this case, a sheet-like elastic member having air permeability such as a stretchable nonwoven fabric may be used, but as shown in FIGS. An elastic member 72 such as a perforated sheet-like, net-like, or elongated (thread-like or string-like) elastic member 72 is fixed between both supporting sheet layers 71 while being stretched along the width direction WD. is preferably used. In this case, the material of the support sheet layer 71 is not particularly limited, but it is preferably a nonwoven fabric having a fineness of 1.6 to 6.0 dtex, a basis weight of 10 to 30 g/m ² and a thickness of 0.1 to 1.3 mm. . The elongation rate of the elastic member 72 is preferably about 150-250%. Further, when an elongated (thread-like or cord-like) elastic member 72 is used, it is preferable to provide about 5 to 15 elastic members having a thickness of 420 to 1120 dtex at intervals of 3 to 10 mm.

Although the width of the stretchable sheet 70 can be determined as appropriate, it is preferable that the stretchable sheet 70 has a width that extends between the left and right side flaps SF as shown in the illustrated example. As for specific dimensions, the width of the stretchable sheet 70 is preferably about 80 to 95% of the total width X of the main body portion excluding the connecting tape 80 .

Both ends of the stretchable sheet 70 in the width direction WD may be non-stretchable regions 76 for holding and attaching by suction during manufacturing. The dimensions of the non-stretchable regions 76 and the dimensions of the intermediate stretchable region 75 positioned between them and stretchable in the width direction WD can be determined as appropriate. The width of the non-stretchable region 76 is preferably about 5 to 50 mm to prevent shrinkage and curling during manufacturing. The non-stretchable region 76 may be a region that does not have the elastic member 72. However, the elastic member 72 is attached over the middle stretchable region 75 and the non-stretchable region 76, and the elastic member 72 is cut in the non-stretchable region 76. A structure in which the elastic member 72 remains in the region 76 but hardly or not stretches at all may be employed.

Moreover, although a part of the elastic member 72 can be arranged so as to traverse the absorbent body 56, as shown in FIG. Alternatively, if the elastic member 72 is cut at a portion or all of the portion overlapping the absorbent body 56 to provide a structure that does not expand or contract at all, the rear end portion of the absorbent body 56 does not shrink in the width direction, so the fit is further improved. improves.

The elastic sheet 70 is arranged between the liquid-impermeable sheet 11 and the absorbent element 50 in the illustrated example, but is not particularly limited to this arrangement. For example, the stretchable sheet 70 may be arranged between the liquid-impermeable sheet 11 and the exterior nonwoven fabric 21 , or may be provided outside the exterior nonwoven fabric 21 .

<Moisture absorption part>
The pants-type disposable diaper and the tape-type disposable diaper described above have a first portion 91 positioned forward of the front end of the absorbent body 56 and a second portion 92 positioned rearward of the rear end of the absorbent body 56 . At least one of the first portion 91 and the second portion 92 is laminated with a plurality of sheet layers 71, 30, 62 having the liquid impermeable sheet 11 and having air permeability on the front side thereof. Alternatively, a plurality of air-permeable sheet layers 12S, 12H, 12r without the liquid-impermeable sheet 11 are laminated, and between the sheet layers 71, 12S, 12H adjacent in the thickness direction Elastic members 15-18, 72 are provided. As a result, at least one or both of the first portion 91 and the second portion 92 are contracted in the width direction WD due to the contraction of the elastic members 15 to 18, 72, and are stretchable in the width direction WD. It has a gather part 90 .

Therefore, for example, in the case of the pants-type disposable diaper described above, as shown in FIG. be. Further, in the case of the tape-type disposable diaper described above, the entire portion of the gathers formed by the elastic sheet 70 that is positioned at the second portion 92 serves as the body gathers 90 .

In such a case, as shown in FIGS. 2, 7, 4, and 15 to 18, only the non-exposed surfaces of the sheet layers 12S, 12H, and 71 in the trunk gather portion 90 are aggregates of microfibrous cellulose. It is preferable to have a moisture absorbing portion 99 to which 98 adheres. For example, in the case of the pants-type disposable diaper having the two-layered exterior bodies 12F and 12B, the non-exposed surface of the sheet layer in the trunk gather portion 90 is the inner surface of the outer sheet layer 12S and the inner sheet as shown in FIG. In the case of the aforementioned underpants-type disposable diaper having the outer body 12 having a three-layer structure, which is the outer surface of the layer 12H, as shown in FIG. It's the outside. In the case of the tape-type disposable diaper described above, both sides of the support sheet layer 71 of the elastic sheet 70, the inner surfaces of the portions of the top sheet 30 and the gathered nonwoven fabric 62 that overlap with the elastic sheet 70 are not exposed in the body gather portion 90. It is the surface. When there are a plurality of non-exposed surfaces of the sheet layer in the trunk gather portion 90 as in these examples, the moisture absorbing portion 99 may be provided only on one surface of them, or the moisture absorbing portion 99 may be provided on any plurality of surfaces. may

The microfibrous cellulose aggregate 98 is porous and highly hydrophilic, and thus has high hygroscopicity. Therefore, by providing the waist gather portion 90 with the moisture absorbing portion 99 to which the aggregates 98 of microfibrous cellulose are adhered, it is possible to reduce stuffiness of the waist gather portion 90, which has not conventionally been prevented from getting stuffy. In addition, since the aggregate 98 of microfibrous cellulose is hard, if it is simply provided at an arbitrary site, it may worsen the feeling of wearing. However, if the aggregate 98 of microfibrous cellulose is provided only on the non-exposed surface of the sheet layer in the trunk gather portion 90, it will not come into direct contact with the skin. In addition, as shown in FIGS. 19 and 20, the sheet layers 12S and 12H of the waist gather portion 90 are compressed due to contraction in the width direction WD and the folds PL formed along with the compression of the material. Compared to , the thickness and stiffness (that is, cushioning properties) are increased both in the natural length state and in the worn state. Therefore, this increase in thickness and stiffness hides the stiffness of the aggregates 98 of microfibrous cellulose. Therefore, the hygroscopic part 99 makes it possible to obtain a high hygroscopic effect by the aggregates 98 of microfibrous cellulose and reduce the hardness of the touch caused by the aggregates 98 of microfibrous cellulose.

Microfibrous cellulose refers to fine cellulose fibers or bundles thereof extracted from plants such as pulp. The median diameter) is preferably 100 nm or less (generally called cellulose nanofibrils (CNF)), and particularly preferably 10 to 60 nm. The average fiber width of microfibrous cellulose can be measured by the following method. That is, first, 100 ml of an aqueous dispersion of microfibrous cellulose having a solid content concentration of 0.01 to 0.1% by mass was filtered through a Teflon (registered trademark) membrane filter, and filtered once with 100 ml of ethanol and 20 ml of t-butanol. Replace the solvent three times. It is then freeze-dried and coated with osmium to form a sample. This sample is observed with an electron microscope SEM image at a magnification of 5000 times, 10000 times or 30000 times (in this example, a magnification of 30000 times) depending on the width of the constituent fibers. Specifically, two diagonal lines are drawn on the observation image, and three straight lines passing through the intersections of the diagonal lines are arbitrarily drawn. Furthermore, a total of 100 fiber rods intersecting with these three straight lines are visually measured. Then, the median diameter (median diameter) of the measured values is defined as the average fiber width.

The adhesion amount of the microfibrous cellulose aggregates 98 on the moisture absorbing portion 99 can be determined as appropriate, but in consideration of moisture absorption and flexibility, it is preferably about 3 to 10 g/m ² , particularly 5 to 7 g/m 2 . About ² is more preferable.

The aggregate 98 of microfibrous cellulose is manufactured by a known method such as forming by applying a microfibrous cellulose dispersion liquid dispersed in a dispersion liquid such as water to the target surface of the target sheet layer and drying it. can do. When the microfibrous cellulose aggregate 98 is formed by applying the microfibrous cellulose dispersion liquid, if the dispersion liquid easily permeates the target sheet layer, the adhesion section is formed over the coating surface and inside, and the target is formed. If the dispersion liquid does not penetrate or hardly penetrates the sheet layer, the adhesion part is formed only on the coated surface. Further, when the dispersion liquid of microfibrous cellulose does not or hardly penetrates into the target sheet layer, the adhered portion of the aggregates 98 of the microfibrous cellulose continues in layers to the applied portion. On the other hand, in the case where the target sheet layer is a non-woven fabric having a certain amount of inter-fiber gaps, when the microfibrous cellulose dispersion is applied, the adhered portions of the microfibrous cellulose aggregates 98 do not form a continuous layer on the applied portion, and are scattered here and there. An aggregate 98 of microfibrous cellulose is lost, and an attached portion is formed in a three-dimensional mesh shape. The latter is preferable from the viewpoint of excellent flexibility and hygroscopicity.

When forming the attachment portion of the aggregate 98 of the microfibrous cellulose by applying the microfibrous cellulose dispersion, the concentration (mass/volume) of the microfibrous cellulose dispersion is 0.1 to 10%. It is preferably 1.0 to 5.0%, particularly preferably 1.5 to 3.0%.

The B-type viscosity (60 rpm, 20° C.) of the microfibrous cellulose dispersion is, for example, 700 cps or less, preferably 200 cps or less, more preferably 50 cps or less. By keeping the B-type viscosity of the microfibrous cellulose dispersion low in this way, the microfibrous cellulose can be uniformly imparted to the nonwoven fabric.

The microfibrous cellulose dispersion can be applied not only by spraying onto the target surface but also by a transfer method such as a letterpress method.

Pulp fibers that can be used for the production of microfibrous cellulose include chemical pulps such as hardwood pulp (LBKP), softwood pulp (NBKP), bleached thermomechanical pulp (BTMP), stone ground pulp (SGP), pressurized stone ground pulp (SGP). Pulp (PGW), refiner ground pulp (RGP), chemi ground pulp (CGP), thermo ground pulp (TGP), ground pulp (GP), thermomechanical pulp (TMP), chemi thermomechanical pulp (CTMP), refiner mechanical pulp From mechanical pulp such as (RMP), waste tea paper, kraft envelope blind paper, magazine waste paper, newspaper waste paper, leaflet waste paper, office waste paper, cardboard waste paper, white waste paper, Kent waste paper, imitation waste paper, certificate waste paper, waste paper waste paper, etc. Waste paper pulp to be produced, deinked pulp (DIP) obtained by deinking waste paper pulp, and the like can be mentioned. These may be used alone or in combination as long as the intended effect is not impaired. Further, the above pulp fibers may be subjected to chemical treatment such as carboxymethylation.

Examples of the method for producing microfibrous cellulose include mechanical methods such as a high-pressure homogenizer method, a microfluidizer method, a grinder grinding method, a bead mill freeze pulverization method, and an ultrasonic defibration method, but are limited to these methods. not a thing In addition, formation of nanofibers is promoted by combined use of TEMPO oxidation treatment, phosphoric acid esterification treatment, acid treatment, and the like.

The adhered portions of the aggregates 98 of microfibrous cellulose may be provided in any pattern. For example, the attachment portion of the aggregate 98 of microfibrous cellulose has a striped shape along the vertical, horizontal, or diagonal directions, a lattice shape (including an oblique lattice shape), a dot shape (scattered dot shape), or a continuous planar shape. can be set to When the adhering portions of the aggregates 98 of microfibrous cellulose are linearly continuous, such as in a striped or grid pattern, they may be linearly continuous, curved lines, or wavy lines. However, since the aggregate 98 of microfibrous cellulose is hard, if it is continuous in the stretching direction, the stretchability of the trunk gather portion 90 may be lowered. Therefore, as shown in FIG. 15(b), in the moisture absorbing portion 99, the adhering portions of the aggregates 98 of microfibrous cellulose are provided in a vertical striped pattern that is continuous in the front-rear direction LD and intermittent in the width direction WD. This is preferable because the fit of the trunk gather portion 90 is less likely to deteriorate. Further, as shown in FIG. 15(c), even if the adhesion portion of the microfibrous cellulose aggregate 98 in the moisture absorbing portion 99 is intermittently provided in the front-rear direction LD and continuous in the width direction WD in the form of horizontal stripes. good. In addition, it is preferable that the aggregate 98 of microfibrous cellulose adhere to a large area in consideration of moisture absorption performance. Therefore, as shown in FIG. 15( a ), an attachment portion of aggregates 98 of microfibrous cellulose may be formed over the entire hygroscopic portion 99 . Even in this case, if the adhesion amount of the microfibrous cellulose aggregates 98 is small (for example, 10 g/m ² or less), excessive reduction in stretchability and excessive hardening of the feel of the trunk gather portion 90 can be prevented. can be suppressed.

The dimensions of the attachment portion of the aggregate 98 of microfibrous cellulose can be determined as appropriate. When the attachment portion of the aggregate 98 of microfibrous cellulose has a dot-like pattern, as shown in FIG. is preferably 1.0 to 4.0 mm, particularly 2.0 to 3.0 mm, and the center (or center of gravity) spacing x1, y1 of adjacent rows in the width direction WD and the front-rear direction LD is 5 to 25 mm, particularly It is preferably 10-15 mm. When the arrangement of the attachment portions of the aggregates 98 of microfibrous cellulose is a striped pattern, the line width of the attachment portions of the aggregates 98 of microfibrous cellulose is 98w is preferably 1.0 to 4.0 mm, particularly 2.0 to 3.0 mm, and the distances x2 and y2 between adjoining microfibrous cellulose aggregates 98 are 5 to 30 mm, particularly 10 to 3.0 mm. 20 mm is preferred.

If importance is placed on hygroscopicity, as shown in FIGS. 16(a), 17(a) and 18(a), the hygroscopic part 99 should be provided only on the non-exposed surface on the side close to the wearer's skin. is preferable, and as shown in FIGS. 16(b), 17(b) and 18(b), if the feel of the wearer is important, only the non-exposed surface on the far side from the wearer's skin absorbs moisture. A portion 99 is preferably provided.

Also, as shown in FIGS. 16, 17, 18(b) and 18(c), a moisture absorbing portion 99 is provided on the facing surface of at least one of the sheet layers 12S, 12H and 71 adjacent to each other with the elastic members 15 to 18 interposed therebetween. Even in the case of providing, as shown in FIG. When the sheet layers 12H are joined with the hot-melt adhesive HM except for the portion overlapping the adhered portion of the microfibrous cellulose assembly 98, the adjacent sheet layers 12S and 12H are reliably joined. Also, in the trunk gather portion 90, the adjacent sheet layers 12S and 12H are joined intermittently at least in the width direction. The portions positioned between the portions contract and swell in opposite directions to form an air passage AR composed of a pair of folds PL, and a moisture absorbing portion 99 is formed only on the inner surface of the air passage AR. Therefore, the breathability of the trunk gather portion 90 is enhanced, and the efficiency of contact with moisture in the air is improved, thereby improving the hygroscopicity of the hygroscopic portion 99 . Note that "joining the adjacent sheet layers 12S and 12H with the hot-melt adhesive HM except for the portion overlapping the adhered portion of the microfibrous cellulose aggregate 98" includes the example shown in FIG. 20(a). In addition to the structure in which the sheet layers 12S and 12H adjacent to each other with the elastic members 15 to 18 sandwiched therebetween are intermittently joined in the width direction by the hot-melt adhesive HM or the like, the structure shown in FIG. As shown, the hot-melt adhesive HM is also present in the portion overlapping the attachment portion of the microfibrous cellulose aggregate 98 (for example, continuous in the width direction), but the overlapping portion is formed by the microfibrous cellulose aggregate 98. Including structures where the hot melt adhesive HM is not functioning (not adhering) due to adhesion inhibition.

The moisture absorbing portion 99 may be provided only in a portion of the waist gather portion 90 or may be provided over the entire waist gather portion 90 . Also, the moisture absorbing portion 99 may extend beyond the waist gathers portion 90 as long as it has a portion located in the waist gathers portion 90 .

For example, in the case of the tape-type disposable diaper described above, the aggregates 98 of microfibrous cellulose can be adhered in the pattern described above over substantially the entire support sheet layer 71 of the elastic sheet 70, as shown in the figure. , the moisture absorbing portion 99 is provided over substantially the entire trunk gather portion 90 .

In the case of a pants-type disposable diaper, the body gathers 90 of the outer bodies 12F, 12B, and 12 are wide. may be provided). Therefore, although it is desirable to provide both the front body F and the back body B with the moisture absorption part 99, only one of the front body F and the back body B may be provided with the moisture absorption part 99. In addition, since the waist portion W of the pants-type disposable diaper is a portion that is pressed against the skin more strongly than other portions, a decrease in the flexibility of the waist portion W tends to lead to deterioration in wearing comfort. Therefore, like the back body B of the illustrated example, it is preferable to provide a moisture absorbing portion 99 in a portion of the trunk gather portion 90 excluding the waist portion W (a portion located in the lower waist portion U). Further, in the case of the pants-type disposable diaper having the three-layer structure outer body 12, as shown in FIG. If the moisture absorbing portion 99 is provided only on the outer surface of the moisture absorbing portion 99, the inner (skin side) and outer thickness of the moisture absorbing portion 99 can be secured by one or more layers, and the hardness of the moisture absorbing portion 99 can be easily hidden.

The dimension of the moisture absorbing portion 99 in the width direction WD can be determined appropriately, but it is preferably about 20 to 100% of the total width X of the disposable diaper. Also, the dimension of the hygroscopic part 99 in the front-rear direction LD can be determined as appropriate, but it is preferably about 10 to 60% of the total length Y of the disposable diaper.

<Description of terms in the specification>
The following terms in the specification have the following meanings unless otherwise specified in the specification.

・"Front-back direction" means the direction (longitudinal direction) indicated by symbol LD in the figure, and "width direction" means the direction (left-right direction) indicated by WD in the figure. are orthogonal.

・"MD direction" and "CD direction" mean the flow direction (MD direction) and the transverse direction (CD direction) perpendicular to this in the manufacturing equipment, and one of them is the front-back direction depending on the part of the product and the other is the width direction. The MD direction of a nonwoven fabric is the direction of fiber orientation of the nonwoven fabric. The fiber orientation is the direction along which the fibers of the nonwoven fabric are aligned. It can be determined by a simple measurement method for determining the orientation direction.

・"Front side" means the side closer to the wearer's skin when the pants-type disposable diaper is worn, and the "back side" means the side farther from the wearer's skin when the pants-type disposable diaper is worn. .

・"Front surface" means the side of the member that is closest to the wearer's skin when wearing the pants-type disposable diaper, and the "back surface" means the side that is close to the wearer's skin when wearing the pants-type disposable diaper. means the far side.

- "Elongation rate" means a value when the natural length is taken as 100%. For example, an elongation rate of 200% is synonymous with an elongation ratio of 2 times.

- "Gel strength" is measured as follows. Artificial urine (urea: 2 wt%, sodium chloride: 0.8 wt%, calcium chloride dihydrate: 0.03 wt%, magnesium sulfate heptahydrate: 0.08 wt%, and deionized water: 97.09 wt% 1.0 g of superabsorbent polymer is added to 49.0 g of the mixture) and stirred with a stirrer. The resulting gel is left in a constant temperature and humidity bath at 40° C. and 60% RH for 3 hours, then returned to room temperature, and the gel strength is measured with a card meter (Curdmeter-MAX ME-500 manufactured by I. techno Engineering).

- "Matsuke" is measured as follows. After pre-drying the sample or test piece, it is left in a test room or apparatus under standard conditions (test location: temperature 23±1° C., relative humidity 50±2%) to a constant weight. Pre-drying refers to making a sample or test piece constant weight in an environment at a temperature of 100°C. Fibers with an official moisture content of 0.0% do not need to be pre-dried. Using a sampling template (100 mm x 100 mm), a sample with dimensions of 100 mm x 100 mm is cut from the constant weight specimen. The weight of the sample is measured, multiplied by 100 to calculate the weight per square meter, and used as basis weight.

- "Thickness" is automatically measured using an automatic thickness gauge (KES-G5 handy compression measurement program) under the conditions of a load of 0.098 N/cm ² and a pressurized area of 2 cm ² . The thickness of the perforated nonwoven fabric is measured at portions other than the perforations and the protrusions around them.

・The amount of water absorption is measured according to JIS K7223-1996 "Testing method for water absorption of superabsorbent resin".

・The water absorption rate is the "time to the end point" when JIS K7224-1996 "Test method for water absorption rate of superabsorbent polymer" is performed using 2g of superabsorbent polymer and 50g of physiological saline. .

- "Unfolded state" means a flat unfolded state without contraction or slack.

・Unless otherwise specified, the dimensions of each part mean the dimensions in the unfolded state, not in the natural length state.

・If there is no description about environmental conditions for testing and measurement, the test and measurement shall be performed in a laboratory or equipment under standard conditions (test location: temperature 23±1°C, relative humidity 50±2%). do.

INDUSTRIAL APPLICABILITY The present invention can be used for absorbent articles in general, including pants-type disposable diapers, tape-type disposable diapers, pad-type disposable diapers, sanitary napkins, and the like.

11 Liquid-impermeable sheet 12 Exterior body 12A Side seal portion 12B Rear exterior body 12F Front exterior body 12H Inner sheet layer 12S Outer sheet layer 19 Unnecessary elastic member 20... Cover nonwoven fabric, 200... Inner body, 201... Inner/outer joint, 30... Top sheet, 40... Intermediate sheet, 50... Absorbent element, 56... Absorbent body, 58... Wrapping sheet, 60... Raised gather, 62... Gathered nonwoven fabric , A1... Non-stretchable area, A2... Stretchable area, C... Buttock cover part, L... Intermediate area, LD... Front-back direction, LO... Leg opening, T... Waist area, U... Lower waist part, W... Waist part, WD...width direction, WO...waist opening, 21...outer nonwoven fabric, 71...supporting sheet layer, 91...first portion, 92...second portion, 90...body gather portion, 99...moisture absorbing portion, 98...microfibrous cellulose 70... Elastic sheet, 15 to 18, 72... Elastic member, PL... Folds.

Claims (4)

It has an absorbent body extending from the front side of the center in the front-back direction to the rear side of the center in the front-back direction, a liquid-permeable top sheet covering the front side of the absorbent body, and a liquid-impermeable sheet covering the back side of the absorbent body. ,
Having a first portion positioned forward of the front end of the absorbent body and a second portion positioned rearward of the rear end of the absorbent body,
The first part and the second part do not have an absorber,
At least one of the first portion and the second portion is laminated with a plurality of sheet layers having the liquid-impermeable sheet and having air permeability on the front side thereof, or the liquid-impermeable A plurality of air-permeable sheet layers having no sheet are laminated, and an elastic member is provided between the plurality of sheet layers,
Having a trunk gather part that is contracted in the width direction by contraction of the elastic member and that is expandable in the width direction,
In absorbent articles,
The plurality of sheet layers in the trunk gather portion have an exposed surface exposed to the outside of the product and a non-exposed surface not exposed to the outside of the product, and at least one facing surface of the sheet layers adjacent to each other with the elastic member interposed therebetween. has a moisture absorbing part to which aggregates of microfibrous cellulose are attached only on the
The hygroscopic portion is provided with a vertically striped pattern that is continuous in the front-rear direction and intermittent in the width direction, and where the assembly of the microfibrous cellulose is attached to the hygroscopic portion.
Adjacent sheet layers with the elastic member interposed therebetween are not joined at the portion overlapping the adhesion portion of the aggregate of microfibrous cellulose, and are hot-melted at portions other than the portion overlapping the adhesion portion of the aggregate of microfibrous cellulose. joined by an adhesive,
An absorbent article characterized by: Having a crotch part including the center in the front-rear direction, a front body extending forward from the center in the front-rear direction, and a back body extending rearward from the center in the front-rear direction,
The back body has side flaps extending laterally of the absorbent body,
Having a connecting tape attached to the side flaps of the back body and detachably connected to the front body,
At least the second portion of the back body has the top sheet and the liquid-impermeable sheet,
Between the top sheet and the liquid-impermeable sheet in the second part, a stretchable sheet elastically stretchable in the width direction,
The stretchable sheet has the elastic member and the sheet layers adjacent to the front side and the back side of the elastic member,
The second portion has a trunk gather portion that is contracted in the width direction due to the contraction of the stretchable sheet and that is stretchable in the width direction,
It is a tape type disposable diaper,
wherein the hygroscopic part is provided on the stretchable sheet;
The absorbent article according to claim 1. an outer body that constitutes at least the waist portion of the front body and the back body; an inner body that includes the absorber attached to the outer body so as to extend from the front body to the back body; a waist opening; A pants-type disposable diaper comprising leg openings,
The exterior body has the first portion and the second portion,
The first part and the second part are laminated with three or more sheet layers that do not have the liquid-impermeable sheet and have air permeability, and the outermost sheet layer and the intermediate sheet layer are laminated. An elastic member is provided between
Having the hygroscopic part only on the outer surface of the intermediate sheet layer in the region having three or more sheet layers,
The absorbent article according to claim 1. The sheet layer having the hygroscopic part is a nonwoven fabric having a fineness of 1.6 to 6.0 dtex, a basis weight of 10 to 30 g/m ² and a thickness of 0.1 to 1.3 mm,
The adhesion amount of the microfibrous cellulose in the hygroscopic part is 5 to 10 g/m ² ,
The absorbent article according to any one of claims 1-3 .

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